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  • 451.
    Agnig, Rushen Robin
    Umeå University, Faculty of Social Sciences, Umeå School of Business and Economics (USBE), Business Administration.
    Valutakursrisker: Bestämningsfaktorer för svenska företags användning av finansiella instrument vid hantering av valutakursrisker.2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    När ett företag importerar eller exporterar varor och tjänster i utländsk valuta kan de exponera sig mot valutakursrisker. Värdet på en valuta idag är kanske inte densamma imorgon vilket kan både gynna och missgynna företag verksamma inom handel. Världsekonomin utsattes för chocker och en av de värsta finansiella kriser upplevdes under 2009/2010. Eftereffekterna kan fortfarande ses av länder exempelvis lokaliserade i Euroområdet. Valutakurser påverkas av makrorelaterad information vilket kan orsaka stora volatila fluktuationer av kurser som kan leda till enorm ekonomisk skada eller stor ekonomisk vinst för företag. För att studera detta närmare genomfördes en enkätstudie på 100 stycken företag i Sverige som var noterade på stockholmsbörsen och/eller onoterade. Genom de kvantitativa data som samlades in kördes en regressionsanalys i SPSS utifrån en OLS funktion. Modellen hade användande av finansiella instrument som beroende variabel. De oberoende variablerna var; policy för hantering av valutakursrisker, kompetens om finansiella instrument i företaget, extern hjälp, övriga valutakursriskminimeringsstrategier, företagets förhållande till risk, skuldkrisen i Europa, beräkning av kostnader och intäkter, procentuell andel av intäkter i utländskvaluta samt procentuell andel kostnader i utländskvaluta. Sedan kontrollerades materialet för att uppfylla vitala antaganden i modellen. Resultatet testades sedan genom ett t-test. Regressionsanalysen visade vid 5 procents signifikants nivå positiva samband mellan användandet av finansiella instrument vid valutakursriskhantering och att ha en utformad policy för hantering av utländsk valuta. Vidare kunde det även härledas positiva samband vid användande av finansiella instrument samt företagets förhållande till risk. Riskaverta förtag tenderar att använda instrument för att minimera valutakursrisker. Analysen kunde även med 10 procents signifikants nivå härleda negativa samband mellan användandet av finansiella instrument samt hantering av övriga valutakursriskminimeringsstrategier. Studien visar likheter med tidigare forskning och finansiell teori.

  • 452.
    Agnvall, Ahlbin
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Chronic exertional compartment syndrome in patients with diabetes mellitus type 1 - Outcome after surgery in 78 patients2017Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 453. Agogo, George O.
    et al.
    van der Voet, Hilko
    van 't Veer, Pieter
    Ferrari, Pietro
    Muller, David C.
    Sanchez-Cantalejo, Emilio
    Bamia, Christina
    Braaten, Tonje
    Knuppel, Sven
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology.
    van Eeuwijk, Fred A.
    Boshuizen, Hendriek C.
    A method for sensitivity analysis to assess the effects of measurement error in multiple exposure variables using external validation data2016In: BMC Medical Research Methodology, ISSN 1471-2288, E-ISSN 1471-2288, Vol. 16, article id 139Article in journal (Refereed)
    Abstract [en]

    Background: Measurement error in self-reported dietary intakes is known to bias the association between dietary intake and a health outcome of interest such as risk of a disease. The association can be distorted further by mismeasured confounders, leading to invalid results and conclusions. It is, however, difficult to adjust for the bias in the association when there is no internal validation data. Methods: We proposed a method to adjust for the bias in the diet-disease association (hereafter, association), due to measurement error in dietary intake and a mismeasured confounder, when there is no internal validation data. The method combines prior information on the validity of the self-report instrument with the observed data to adjust for the bias in the association. We compared the proposed method with the method that ignores the confounder effect, and with the method that ignores measurement errors completely. We assessed the sensitivity of the estimates to various magnitudes of measurement error, error correlations and uncertainty in the literature-reported validation data. We applied the methods to fruits and vegetables (FV) intakes, cigarette smoking (confounder) and all-cause mortality data from the European Prospective Investigation into Cancer and Nutrition study. Results: Using the proposed method resulted in about four times increase in the strength of association between FV intake and mortality. For weakly correlated errors, measurement error in the confounder minimally affected the hazard ratio estimate for FV intake. The effect was more pronounced for strong error correlations. Conclusions: The proposed method permits sensitivity analysis on measurement error structures and accounts for uncertainties in the reported validity coefficients. The method is useful in assessing the direction and quantifying the magnitude of bias in the association due to measurement errors in the confounders.

  • 454. Agogo, George O.
    et al.
    van der Voet, Hilko
    van't Veer, Pieter
    Ferrari, Pietro
    Leenders, Max
    Muller, David C.
    Sanchez-Cantalejo, Emilio
    Bamia, Christina
    Braaten, Tonje
    Knueppel, Sven
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology.
    van Eeuwijk, Fred A.
    Boshuizen, Hendriek
    Use of Two-Part Regression Calibration Model to Correct for Measurement Error in Episodically Consumed Foods in a Single-Replicate Study Design: EPIC Case Study2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 11, p. e113160-Article in journal (Refereed)
    Abstract [en]

    In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted twopart regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM) and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC) study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model.

  • 455.
    Agorelius, Emma
    et al.
    Umeå University, Faculty of Social Sciences, Umeå School of Business and Economics (USBE), Business Administration.
    Ek, Anna
    Immateriella tillgångars inverkan på ett företags finansiering: En studie på onoterade svenska företag2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    I takt med att samhällsekonomin har blivit mer kunskapsbaserad har ett företags immateriella tillgångar fått en allt mer betydelsefull roll. Immateriella tillgångar medför dock flera aspekter av osäkerhet, bland annat hur äganderätten ska bestämmas, hur ett tillförlitligt värde ska beräknas samt vilka kriterier som ska gälla för att få ta upp den till redovisning. Svårigheten och komplexiteten detta innebär har gjort att företagens finansiella rapporter har i vissa avseenden tappat sin relevans, exempelvis användbarheten kopplat till externa parters beslutsfattande. Syftet med vår studie är att undersöka om det finns ett samband mellan ett företags tillgångsstruktur och den skuldränta företaget betalar till kreditgivare för sina lån, men även hur tillgångsstrukturen påverkar företagens finansieringsmöjligheter.

    Vetenskapliga utgångspunkter för vår studie är en ontologisk verklighetssyn, en positivistisk vetenskapssyn, en deduktiv forskningsansats samt en kvantitativ metod där hypotesprövning är i fokus. Undersökningen är uppbyggd utifrån ett företagsperspektiv då det är framförallt företag vi vänder oss till. Baserat på studiens teoretiska ramverk tog vi fram två hypoteser att undersöka under en femårsperiod. Studiens huvudhypotes syftar till att undersöka sambandet mellan immateriella tillgångar och skuldränta medan bihypotesen fokuserar på sambandet mellan immateriella tillgångar och företagens andel lån. Vi testade dessa hypoteser genom två olika undersökningar, först genom en totalundersökning då vi undersökte om existensen av upptagna immateriella tillgångar hade någon inverkan på responsvariablerna, och sedan genom en klusterundersökning då vi undersökte hur mängden immateriella tillgångar inverkar på responsvariablerna.

    Resultatet från studiens huvudhypotes visar att det finns ett positivt samband mellan existensen av upptagna immateriella tillgångar och skuldräntan, det innebär att om företaget har upptagna immateriella tillgångar får de betala en högre skuldränta. Detta kan bero på att immateriella tillgångar är osäkrare och därmed vill långivare ha en högre ränta som kompensation. Däremot är sambandet mellan andel upptagna immateriella tillgångar och skuldränta negativt samt har låga och varierande förklaringsgrader mellan åren. Detta kan bero på att de finansiella rapporterna har tappat i relevans och att kreditgivare lägger större vikt vid kvalitativa aspekter, vilka inte syns i balansräkning och som vår studie därmed inte fångar upp. Gällande resultaten från bihypotesen så kan vi inte uttala oss om sambandet mellan existensen av upptagna immateriella tillgångar och företagens andel lån. Däremot ser vi ett svagt och något instabilt positivt samband mellan andel upptagna immateriella tillgångar och andel lån, vilket kan bero på att företag med mycket immateriella värden har fler investeringstillfällen och därmed kräver mer extern finansiering för att kunna ta tillvara på dessa och vara konkurrenskraftiga.

    Studien är upprättad utifrån etiska aspekter samt har överlag en god reliabilitet och validitet. Förslag på vidare forskning är framförallt att genomföra studien genom en kvalitativ metod för att få en djupare förståelse för kreditgivningens kvalitativa del vilket skulle komplettera denna studie. Praktiska rekommendationer till företag är att fortsätta kämpa för sina värdefulla immateriella tillgångar för att uppnå en mer jämställd kreditgivningsprocess vilket går i linje med världens kunskapsbaserade ekonomi.

  • 456. Agostinelli, Marta
    et al.
    Cleary, Michelle
    Martin, Juan A.
    Albrectsen, Benedicte R.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Witzell, Johanna
    Pedunculate Oaks (Quercus robur L.) Differing in Vitality as Reservoirs for Fungal Biodiversity2018In: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 9, article id 1758Article in journal (Refereed)
    Abstract [en]

    Ecological significance of trees growing in urban and peri-urban settings is likely to increase in future land-use regimes, calling for better understanding of their role as potential reservoirs or stepping stones for associated biodiversity. We studied the diversity of fungal endophytes in woody tissues of asymptomatic even aged pedunculate oak trees, growing as amenity trees in a peri-urban setting. The trees were classified into three groups according to their phenotypic vitality (high, medium, and low). Endophytes were cultured on potato dextrose media from surface sterilized twigs and DNA sequencing was performed to reveal the taxonomic identity of the morphotypes. In xylem tissues, the frequency and diversity of endophytes was highest in oak trees showing reduced vitality. This difference was not found for bark samples, in which the endophyte infections were more frequent and communities more diverse than in xylem. In general, most taxa were shared across the samples with few morphotypes being recovered in unique samples. Leaf phenolic profiles were found to accurately classify the trees according to their phenotypic vitality. Our results confirm that xylem is more selective substrate for endophytes than bark and that endophyte assemblages in xylem are correlated to the degree of host vitality. Thus, high vitality of trees may be associated with reduced habitat quality to wood-associated endophytes.

  • 457. Agostoni, C
    et al.
    Buonocore, G
    Carnielli, VP
    De Curtis, M
    Darmaun, D
    Decsi, T
    Domellöf, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Embleton, ND
    Fusch, C
    Genzel-Boroviczeny, O
    Goulet, O
    Kalhan, SC
    Kolacek, S
    Koletzko, B
    Lapillonne, A
    Mihatsch, W
    Moreno, L
    Neu, J
    Poindexter, B
    Puntis, J
    Putet, G
    Rigo, J
    Riskin, A
    Salle, B
    Sauer, P
    Shamir, R
    Szajewska, H
    Thureen, P
    Turck, D
    van Goudoever, JB
    Ziegler, EE
    Enteral nutrient supply for preterm infants: commentary from the European society of paediatric gastroenterology, hepatology and nutrition committee on nutrition2010In: Journal of Pediatric Gastroenterology and Nutrition - JPGN, ISSN 0277-2116, E-ISSN 1536-4801, Vol. 50, no 1, p. 85-91Article in journal (Refereed)
    Abstract [en]

    The number of surviving children born prematurely has increased substantially during the last 2 decades. The major goal of enteral nutrient supply to these infants is to achieve growth similar to foetal growth coupled with satisfactory functional development. The accumulation of knowledge since the previous guideline on nutrition of preterm infants from the Committee on Nutrition of the European Society of Paediatric Gastroenterology and Nutrition in 1987 has made a new guideline necessary. Thus, an ad hoc expert panel was convened by the Committee on Nutrition of the European Society of Paediatric Gastroenterology, Hepatology, and Nutrition in 2007 to make appropriate recommendations. The present guideline, of which the major recommendations are summarised here (for the full report, see http://links.lww.com/A1480), is consistent with, but not identical to, recent guidelines from the Life Sciences Research Office of the American Society for Nutritional Sciences published in 2002 and recommendations from the handbook Nutrition of the Preterm Infant. Scientific Basis and Practical Guidelines, 2nd ed, edited by Tsang et al, and published in 2005. The preferred food for premature infants is fortified human milk from the infant's own mother, or, alternatively, formula designed for premature infants. This guideline aims to provide proposed advisable ranges for nutrient intakes for stable-growing preterm infants up to a weight of approximately 1800 g, because most data are available for these infants. These recommendations are based on a considered review of available scientific reports on the subject, and on expert consensus for which the available scientific data are considered inadequate.

  • 458. Agostoni, Carlo
    et al.
    Domellöf, Magnus
    Umeå University, Faculty of Medicine, Clinical Sciences, Paediatrics.
    Infant formulae: from ESPGAN recommendations towards ESPGHAN-coordinated global standards.2005In: Journal of pediatric gastroenterology and nutrition, ISSN 0277-2116, Vol. 41, no 5, p. 580-3Article in journal (Other academic)
  • 459. Agrawal, Ganesh Kumar
    et al.
    Job, Dominique
    Kieselbach, Thomas
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Barkla, Bronwyn J.
    Chen, Sixue
    Deswal, Renu
    Luethje, Sabine
    Amalraj, Ramesh Sundar
    Tanou, Georgia
    Ndimba, Bongani Kaiser
    Cramer, Rainer
    Weckwerth, Wolfram
    Wienkoop, Stefanie
    Dunn, Michael J.
    Kim, Sun Tae
    Fukao, Yochiro
    Yonekura, Masami
    Zolla, Lello
    Rohila, Jai Singh
    Waditee-Sirisattha, Rungaroon
    Masi, Antonio
    Wang, Tai
    Sarkar, Abhijit
    Agrawal, Raj
    Renaut, Jenny
    Rakwal, Randeep
    INPPO Actions and Recognition as a Driving Force for Progress in Plant Proteomics: Change of Guard, INPPO Update, and Upcoming Activities2013In: Proteomics, ISSN 1615-9853, E-ISSN 1615-9861, Vol. 13, no 21, p. 3093-3100Article in journal (Other academic)
    Abstract [en]

    The International Plant Proteomics Organization (INPPO) is a non-profit organization whose members are scientists involved or interested in plant proteomics. Since the publication of the first INPPO highlights in 2012, continued progress on many of the organization's mandates/goals has been achieved. Two major events are emphasized in this second INPPO highlights. First, the change of guard at the top, passing of the baton from Dominique Job, INPPO founding President to Ganesh Kumar Agrawal as the incoming President. Ganesh K. Agrawal, along with Dominique Job and Randeep Rakwal initiated the INPPO. Second, the most recent INPPO achievements and future targets, mainly the organization of first the INPPO World Congress in 2014, tentatively planned for Hamburg (Germany), are mentioned.

  • 460. Agrawal, Ganesh Kumar
    et al.
    Sarkar, Abhijit
    Agrawal, Raj
    Ndimba, Bongani Kaiser
    Tanou, Georgia
    Dunn, Michael J
    Kieselbach, Thomas
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Cramer, Rainer
    Wienkoop, Stefanie
    Chen, Sixue
    Rafudeen, Mohammed Suhail
    Deswal, Renu
    Barkla, Bronwyn J
    Weckwerth, Wolfram
    Heazlewood, Joshua L
    Renaut, Jenny
    Job, Dominique
    Chakraborty, Niranjan
    Rakwal, Randeep
    Boosting the Globalization of Plant Proteomics through INPPO: Current Developments and Future Prospects2012In: Proteomics, ISSN 1615-9853, E-ISSN 1615-9861, Vol. 12, no 3, p. 359-368Article in journal (Refereed)
    Abstract [en]

    The International Plant Proteomics Organization (INPPO) is a non-profit-organization consisting of people who are involved or interested in plant proteomics. INPPO is constantly growing in volume and activity, which is mostly due to the realization among plant proteomics researchers worldwide for the need of such a global platform. Their active participation resulted in the rapid growth within the first year of INPPO's official launch in 2011 via its website (www.inppo.com) and publication of the 'Viewpoint paper' in a special issue of PROTEOMICS (May 2011). Here, we will be highlighting the progress achieved in the year 2011 and the future targets for the year 2012 and onwards. INPPO has achieved a successful administrative structure, the Core Committee (CC; composed of President, Vice-President, and General Secretaries), Executive Council (EC), and General Body (GB) to achieve INPPO objectives. Various committees and subcommittees are in the process of being functionalized via discussion amongst scientists around the globe. INPPO's primary aim to popularize the plant proteomics research in biological sciences has also been recognized by PROTEOMICS where a section dedicated to plant proteomics has been introduced starting January 2012, following the very first issue of this journal devoted to plant proteomics in May 2011. To disseminate organizational activities to the scientific community, INPPO has launched a biannual (in January and July) newsletter entitled 'INPPO Express: News & Views' with the first issue published in January 2012. INPPO is also planning to have several activities in 2012, including programs within the Education Outreach committee in different countries, and the development of research ideas and proposals with priority on crop and horticultural plants, while keeping tight interactions with proteomics programs on model plants such as Arabidopsis thaliana, rice, and Medicago truncatula. Altogether, the INPPO progress and upcoming activities are because of immense support, dedication, and hard work of all members of the INPPO community, and also due to the wide encouragement and support from the communities (scientific and non-scientific).

  • 461. Agrawala, Shardul
    et al.
    Bosello, Francesco
    Carraro, Carlo
    de Bruin, Kelly
    Umeå University, Faculty of Social Sciences, Department of Economics.
    De Cian, Enrica
    Dellink, Rob
    Lanzi, Elisa
    Plan or react? Analysis of adaptation costs and benefits using integrated assessment models2011In: Climate Change Economics, ISSN 2010-0078, E-ISSN 2010-0086, Vol. 2, no 3, p. 175-208Article in journal (Refereed)
    Abstract [en]

    This report examines adaptation and mitigation within an integrated framework. Global and regional costs of adaptation are assessed dynamically and the resulting benefits are quantified. This is accomplished by developing a framework to incorporate adaptation as a policy variable within three Integrated Assessment Models (IAMs); the global Dynamic Integrated model of Climate and the Economy (DICE), the Regional Integrated model of Climate and the Economy (RICE), and the World Induced Technical Change Hybrid (WITCH) model. The framework developed here takes into account investments in reactive adaptation and in adaptation "stocks", as well as investments in building adaptive capacity. This report presents the first inter-model comparison of results on adaptation costs using the emerging category of adaptation-IAMs. Results show that least-cost policy response to climate change will need to involve subsantial amounts of mitigation efforts, investments in adaptation stock, reactive adaptation measures and adaptive capacity to limit the remaining damages.

  • 462.
    Agrell, Elias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys av massapumps- och mixerarbete vid Metsä Board Sverige AB, Husums Fabriker: Energibesparingsåtgärder vid blekeri 4 & 5 med jämförelse mot ny utrustning2014Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    Husums plant has a selection of different pulp pumps at bleaching plant 4 and 5. The displacement- (HC-pump, Sund Defibrator PTD-60) and centrifugalpumps (MC-pump, MCA 42-200, MCP 30/20) are of interest in this report. The centrifugal pumps are controlled by throttle valves, which result in an energy loss. Chemical mixers are used to mix ClO2 into the pulp before proceeding into a holding tower where the bleaching process occurs.

    The energy demand of the different positions has been measured or calculated to be used in comparisons against new equipment. Quotations were requested and delivered from Valmet and Sulzer. The quotations were made with a production increase of 10 ADMt/h and plant compared to current equipment. Therefore energy need of the equipment in the quotation had to be recalculated to the same production output as when measurements were conducted to be comparable. Quotation of the pumps assumes the use of frequency inverters.

    A deeper investigation was made for 441PU255 which is located at bleaching plant 4. The drop leg level of the pump is controlled via a throttle valve. A frequency inverter is installed but not utilized to maintain constant pulp level in the drop leg. This was due to physical changes in the process not being compensated for in the control system. This caused the drop leg level to oscillate when automatic control was used. As a workaround the drive had been set at a constant speed. To investigate the potential savings, an attempt was made in which the speed was lowered from 1520 rpm to 1100 rpm, resulting in a power reduction of 82 kW or 342,081 Sek per year at a production of 36 ADMT/h. The experiment was done with slightly lower production output than desirable; because of this, savings will decrease slightly at higher outputs.

    Comparisons showed that considerable amounts of energy could be saved at all positions. However the investment cost is high and therefore favorable payback times can only be seen for some of the positions. The MC-pumps are oversized and in need of constant throttling therefore the majority of the energy savings is made through the installation of frequency inverters and not the pump upgrade.

  • 463.
    Agrell, Johanna
    Umeå University, Faculty of Social Sciences, Department of Education.
    Åtgärdsprogram - en klyfta mellan ideologi och praktik?: En studie om hur lärare och rektorer i en kommun förstår direktiv rörande åtgärdsprogram2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 464.
    Agrell, Daniel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Optimerad design och tillverkningsmetod av koncentrerande solfångare2015Independent thesis Advanced level (degree of Master (Two Years)), 300 HE creditsStudent thesis
    Abstract [en]

    The sun is our most important source of energy for us to be able to cope with the evermore pressuring climate threats. This has always been very clear for Absolicon Solar Collector AB in Härnösand, developers of concentrating solar collectors. The company has so far produced solar collectors which can produce both thermal and electrical power for mid-sized installations such as hotels and hospital. Now however, they are changing direction. Absolicon wants to address the many bigger industries with a demand for steam, in countries rich with solar radiation. Absolicon also wants to develop a production line for production of their solar collector, for deployment in the countries where the demand is the biggest.

     

    In a project partially financed by the Swedish energy department, a demonstrational production line will be built in Härnösand. The production line will be used to build a demonstrational field at HEMAB (Härnösands Energi och Miljö AB) with a new generation of solar collectors, optimized for steam production. The solar collectors built today has a problem with the reflector not getting an optimized shape throughout the whole collector. This has to be rectified since the demand on the shape of the reflector is higher on the new generation of solar collectors. This Is due to the use of a smaller receiver. Furthermore a mounting carriage using a new production method is to be developed for the production line. The mounting carriage should, by using vacuum, form and fixate the reflector of the collector while it also optimizes its shape.

     

    Tests was performed to examine how to optimize the shape of the reflector. A test rig was used to examine how a thin sheet of metal can be formed and fixated using vacuum while developing an optimized production method. A prototype carriage for production of 2 m long collectors using the new method was designed and constructed for evaluation.

     

    The results of the evaluation showed that the developed method is working well and that a receiver diameter of 19 mm can be used. The method is based on letting the edges of the reflector sheet hang free, which eliminates unwanted tensions in the reflector.

     

    The prototype which was built is ready for upscaling to a 6 m mounting carriage which will be able to produce the new generation of solar collectors for the demonstration field. A mounting process for production of solar collectors in a production line has been proposed which can shorten the mounting time and work load to less than 45 minutes and 1-2 persons per collector.

    The full text will be freely available from 2025-09-01 20:46
  • 465. Agren, Per-Henrik
    et al.
    Tullberg, Tycho
    Mukka, Sebastian
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Wretenberg, Per
    Sayed-Noor, Arkan S.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Post-traumatic in situ fusion after calcaneal fractures: A retrospective study with 7-28 years follow-up2015In: Foot and Ankle Surgery, ISSN 1268-7731, E-ISSN 1460-9584, Vol. 21, no 1, p. 56-59Article in journal (Refereed)
    Abstract [en]

    Background: In situ fusion as salvage operation after calcaneal fractures has been used. In this retrospective investigation, a group of in situ fused patients is analyzed with long-term follow-up.

    Methods: Twenty-nine patients with in situ single or multiple fusions performed between 1970 and 1990 were included. In 1998 these patients were examined with plain radiographs and computerized tomography (CT) scan of the affected foot. Also, a visual analogue score (VAS) for calcaneal fractures, short form health survey (SF-36), Olerud Molander score and American Orthopaedic Foot and Ankle society (AOFAS) hindfoot score were evaluated.

    Results: The plain radiographs and CT scan showed severe remaining deformities in these patients. The outcome parameters were generally poor and correlated to the degree of remaining deformity.

    Conclusions: Simple in situ fusion, without consideration of the deformity at hand, after a calcaneal fracture is not an adequate treatment and generally associated with poor outcome. (C) 2014 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  • 466. Agreus, Lars
    et al.
    Hellström, Per M.
    Talley, Nicholas J.
    Wallner, Bengt
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Forsberg, Anna
    Vieth, Michael
    Veits, Lothar
    Björkegren, Karin
    Engstrand, Lars
    Andreasson, Anna
    Towards a healthy stomach? Helicobacter pylori prevalence has dramatically decreased over 23 years in adults in a Swedish community2016In: United European Gastroenterology journal, ISSN 2050-6406, E-ISSN 2050-6414, Vol. 4, no 5, p. 686-696Article in journal (Refereed)
    Abstract [en]

    Background In Western countries the prevalence of Helicobacter pylori (H. pylori) infection may be declining but there is a lack of recent longitudinal population studies. We evaluated the changing epidemiology over a 23-year period in Sweden. Materials and methods In 1989, the validated Abdominal Symptom Questionnaire (ASQ) was mailed to a random sample of inhabitants (ages 22-80 years) in a Swedish community, and 1097 (87%) responded. H. pylori serology was analysed in a representative subsample (n=145). Twenty-three years later, the ASQ was mailed again using similar selection criteria, and 388 out of 1036 responders had an upper endoscopy with assessment of H. pylori and corpus atrophy status. Results The prevalence of positive H. pylori serology decreased from 37.9% (1989) to 15.8% (2012), corresponding to a decrease in odds of 75% per decade (odds ratio (OR): 0.25; 95% confidence interval (CI): 0.11-0.59, p=0.001) independent of age, gender, body mass index (BMI) and level of education, with a pattern consistent with a birth cohort effect. The prevalence increased with increasing age (p=0.001). The prevalence of H. pylori on histology in 2012 was 11.4% (95% CI 8.6-15.0). The prevalence of corpus atrophy on serology and/or histology in 2012 was 3.2% (95% CI 1.8-5.5); all cases were 57 years old. Conclusion The stomach is healthier in 2012 compared with 1989. H. pylori prevalence in adults has decreased over the last two decades to a level where clinical management might be affected.

  • 467.
    Agritellis, Ioannis
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Social media as the Cosmo Neighborhood2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The world has been transformed through the internet into a "global village",and social media platforms have possibly transformed the world into a larger neighborhood covering many regions of the world. Social networks such as Facebook and Twitter came into people’s lives through the Internet, growing daily at a large rate, and it has been proven that they are very popular. This study examines links between different phenomena through social media platforms (e.g. Facebook, Twitter, blogs, etc.). It is discusses cohesiveness, desire to belong, sense of community, beliefs and opinions about different forms of these phenomena in popular virtual platforms in correlation with trust in social media, criticism of information that is spread by these virtual platforms, and if people are influenced in consumer decision making. A questionnaire has been distributed to a convenient sample of 159 international and Swedish students in Sweden in October-November 2012 in both English and Swedish versions. According to the peoples’ answers, tendencies were observed such as to not trust the platforms, and also the information received, beliefs such that social media are "controlled", negative critique, but also an expression for a need for ‘membership’.

  • 468.
    Agronius, Sofia
    et al.
    Umeå University, Faculty of Arts, Department of Creative Studies.
    Sjöberg, Eva
    Umeå University, Faculty of Arts, Department of Creative Studies.
    Hur elever upplever betyg och bedömning i bild- och medieämnen: - en kvalitativ studie2008Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Betygen är en självklar och ofrånkomlig del i skolans vardag och diskussioner förs hela tiden kring dess utformning, genomförande och betydelse i samhällsdebatten. Ofta är det politikers åsikter man får höra när det gäller betyg och bedömning. Men de som påverkas mest av betygen, eleverna som går i skolan just nu, hur tänker de? Syftet med undersökningen är att genom kvalitativa intervjuer ta reda på hur gymnasieelever upplever betyg och bedömning i bild- och medieämnen. Vi kan se att det finns en uppdelning i elevernas svar. Å ena sidan finns den individuella upplevelsen å andra sidan den upplevelse som knyts till kontexten – skola, lärare, kamrater och framtid. En elev kan ha både positiva och negativa erfarenheter och därigenom ha ett brett spektra av upplevelser. Det visar på en komplexitet i upplevelsen av att bli bedömd och betygsatt.

    Detta är en del av ett så kallat alternativt examensarbete där den första delen är denna uppsats och den andra består av en tidning som utformats som diskussionsunderlag för skolan i ämnet.

    Tidningen finns i digital form på http://www.estet.umu.se/alt.exarb/ men även som bilaga i detta arbete.

  • 469. Agudo, Antonio
    et al.
    Bonet, Catalina
    Sala, Núria
    Muñoz, Xavier
    Aranda, Núria
    Fonseca-Nunes, Ana
    Clavel-Chapelon, Françoise
    Boutron-Ruault, Marie Christine
    Vineis, Paolo
    Panico, Salvatore
    Palli, Domenico
    Tumino, Rosario
    Grioni, Sara
    Quirós, J Ramón
    Molina, Esther
    Navarro, Carmen
    Barricarte, Aurelio
    Chamosa, Saioa
    Allen, Naomi E
    Khaw, Kay-Tee
    Bueno-de-Mesquita, H Bas
    Siersema, Peter D
    Numans, Mattijs E
    Trichopoulou, Antonia
    Lagiou, Pagona
    Trichopoulos, Dimitrios
    Kaaks, Rudof
    Canzian, Federico
    Boeing, Heiner
    Meidtner, Karina
    Johansson, Mattias
    Umeå University, Faculty of Medicine. WHO, IARC, Lyon, France.
    Sund, Malin
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Manjer, Jonas
    Overvad, Kim
    Tjonneland, Anne
    Lund, Eiliv
    Weiderpass, Elisabete
    Jenab, Mazda
    Fedirko, Veronika
    Offerhaus, G Johan A
    Riboli, Elio
    González, Carlos A
    Jakszyn, Paula
    Hemochromatosis (HFE) gene mutations and risk of gastric cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) study2013In: Carcinogenesis, ISSN 0143-3334, E-ISSN 1460-2180, Vol. 34, no 6, p. 1244-1250Article in journal (Refereed)
    Abstract [en]

    Hereditary hemochromatosis (HH) is a strong risk factor for hepatocellular cancer, and mutations in the HFE gene associated with HH and iron overload may be related to other tumors, but no studies have been reported for gastric cancer (GC). A nested case-control study was conducted within the European Prospective Investigation into Cancer and Nutrition (EPIC), including 365 incident gastric adenocarcinoma and 1284 controls matched by center, sex, age and date of blood collection. Genotype analysis was performed for two functional polymorphisms (C282Y/rs1800562 and H63D/rs1799945) and seven tagSNPs of the HFE genomic region. Association with all gastric adenocarcinoma, and according to anatomical localization and histological subtype, was assessed by means of the odds ratio (OR) and 95% confidence interval (CI) estimated by unconditional logistic regression adjusted for the matching variables. We observed a significant association for H63D with OR (per rare allele) of 1.32 (CI = 1.03-1.69). In subgroup analyses, the association was stronger for non-cardia anatomical subsite (OR = 1.60, CI = 1.16-2.21) and intestinal histological subtype (OR = 1.82, CI = 1.27-2.62). Among intestinal cases, two tagSNPs (rs1572982 and rs6918586) also showed a significant association that disappeared after adjustment for H63D. No association with tumors located in the cardia or with diffuse subtype was found for any of the nine SNPs analyzed. Our results suggest that H63D variant in HFE gene seems to be associated with GC risk of the non-cardia region and intestinal type, possibly due to its association with iron overload although a role for other mechanisms cannot be entirely ruled out.

  • 470. Agudo, Antonio
    et al.
    Bonet, Catalina
    Travier, Noemie
    Gonzalez, Carlos A.
    Vineis, Paolo
    Bueno-de-Mesquita, H. Bas
    Trichopoulos, Dimitrios
    Boffetta, Paolo
    Clavel-Chapelon, Francoise
    Boutron-Ruault, Marie-Christine
    Kaaks, Rudolf
    Lukanova, Annekatrin
    Schuetze, Madlen
    Boeing, Heiner
    Tjonneland, Anne
    Halkjaer, Jytte
    Overvad, Kim
    Dahm, Christina C.
    Ramon Quiros, J.
    Sanchez, Maria-Jose
    Larranaga, Nerea
    Navarro, Carmen
    Ardanaz, Eva
    Khaw, Kay-Tee
    Wareham, Nicholas J.
    Key, Timothy J.
    Allen, Naomi E.
    Trichopoulou, Antonia
    Lagiou, Pagona
    Palli, Domenico
    Sieri, Sabina
    Tumino, Rosario
    Panico, Salvatore
    Boshuizen, Hendriek
    Buchner, Frederike L.
    Peeters, Petra H. M.
    Borgquist, Signe
    Almquist, Martin
    Hallmans, Göran
    Umeå University, Faculty of Medicine, Department of Biobank Research.
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Gram, Inger T.
    Lund, Eiliv
    Weiderpass, Elisabete
    Romieu, Isabelle
    Riboli, Elio
    Impact of Cigarette Smoking on Cancer Risk in the European Prospective Investigation into Cancer and Nutrition Study2012In: Journal of Clinical Oncology, ISSN 0732-183X, E-ISSN 1527-7755, Vol. 30, no 36, p. 4550-4557Article in journal (Refereed)
    Abstract [en]

    Purpose Our aim was to assess the impact of cigarette smoking on the risk of the tumors classified by the International Agency for Research on Cancer as causally associated with smoking, referred to as tobacco-related cancers (TRC). Methods The study population included 441,211 participants (133,018 men and 308,193 women) from the European Prospective Investigation Into Cancer and Nutrition. We investigated 14,563 participants who developed a TRC during an average follow-up of 11 years. The impact of smoking cigarettes on cancer risk was assessed by the population attributable fraction (AF(p)), calculated using the adjusted hazard ratios and 95% CI for current and former smokers, plus either the prevalence of smoking among cancer cases or estimates from surveys in representative samples of the population in each country. Results The proportion of all TRC attributable to cigarette smoking was 34.9% (95% CI, 32.5 to 37.4) using the smoking prevalence among cases and 36.2% (95% CI, 33.7 to 38.6) using the smoking prevalence from the population. The AF(p) were above 80% for cancers of the lung and larynx, between 20% and 50% for most respiratory and digestive cancers and tumors from the lower urinary tract, and below 20% for the remaining TRC. Conclusion Using data on cancer incidence for 2008 and our AF(p) estimates, about 270,000 new cancer diagnoses per year can be considered attributable to cigarette smoking in the eight European countries with available data for both men and women (Italy, Spain, United Kingdom, the Netherlands, Greece, Germany, Sweden, Denmark). 

  • 471. Agudo, Antonio
    et al.
    Cayssials, Valerie
    Bonet, Catalina
    Tjønneland, Anne
    Overvad, Kim
    Boutron-Ruault, Marie-Christine
    Affret, Aurélie
    Fagherazzi, Guy
    Katzke, Verena
    Schübel, Ruth
    Trichopoulou, Antonia
    Karakatsani, Anna
    La Vecchia, Carlo
    Palli, Domenico
    Grioni, Sara
    Tumino, Rosario
    Ricceri, Fulvio
    Panico, Salvatore
    Bueno-de-Mesquita, Bas
    Peeters, Petra H.
    Weiderpass, Elisabete
    Skeie, Guri
    Nøst, Theresa H.
    Lasheras, Cristina
    Rodríguez-Barranco, Miguel
    Amiano, Pilar
    Chirlaque, María-Dolores
    Ardanaz, Eva
    Ohlsson, Bodil
    Dias, Joana A.
    Nilsson, Lena M.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Nutritional Research. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Myte, Robin
    Khaw, Kay-Tee
    Perez-Cornago, Aurora
    Gunter, Marc
    Huybrechts, Inge
    Cross, Amanda J.
    Tsilidis, Kostas
    Riboli, Elio
    Jakszyn, Paula
    Inflammatory potential of the diet and risk of gastric cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) study2018In: American Journal of Clinical Nutrition, ISSN 0002-9165, E-ISSN 1938-3207, Vol. 107, no 4, p. 607-616Article in journal (Refereed)
    Abstract [en]

    Chronic inflammation plays a critical role in the pathogenesis of the 2 major types of gastric cancer. Several foods, nutrients, and nonnutrient food components seem to be involved in the regulation of chronic inflammation. We assessed the association between the inflammatory potential of the diet and the risk of gastric carcinoma, overall and for the 2 major subsites: cardia cancers and noncardia cancers. A total of 476,160 subjects (30% men, 70% women) from the European Investigation into Cancer and Nutrition (EPIC) study were followed for 14 y, during which 913 incident cases of gastric carcinoma were identified, including 236 located in the cardia, 341 in the distal part of the stomach (noncardia), and 336 with overlapping or unknown tumor site. The dietary inflammatory potential was assessed by means of an inflammatory score of the diet (ISD), calculated with the use of 28 dietary components and their corresponding inflammatory scores. The association between the ISD and gastric cancer risk was estimated by HRs and 95% CIs calculated by multivariate Cox regression models adjusted for confounders. The inflammatory potential of the diet was associated with an increased risk of gastric cancer. The HR (95% CI) for each increase in 1 SD of the ISD were 1.25 (1.12, 1.39) for all gastric cancers, 1.30 (1.06, 1.59) for cardia cancers, and 1.07 (0.89, 1.28) for noncardia cancers. The corresponding values for the highest compared with the lowest quartiles of the ISD were 1.66 (1.26, 2.20), 1.94 (1.14, 3.30), and 1.07 (0.70, 1.70), respectively. Our results suggest that low-grade chronic inflammation induced by the diet may be associated with gastric cancer risk. This pattern seems to be more consistent for gastric carcinomas located in the cardia than for those located in the distal stomach. This study is listed on the ISRCTN registry as ISRCTN12136108.

  • 472. Agudo, Antonio
    et al.
    Sala, Naría
    Pera, Guillem
    Capella, Gabriel
    Berenguer, Antonio
    García, Nadia
    Palli, Domenico
    Boeing, Heiner
    Del Giudice, Giuseppe
    Saieva, Calogero
    Carneiro, Fatima
    Berrino, Franco
    Sacerdote, Carlotta
    Tumino, Rosario
    Panico, Salvatore
    Berglund, Göran
    Siman, Henrik
    Stenling, Roger
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology. Patologi.
    Hallmans, Göran
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Nutritional Research.
    Martínez, Carmen
    Bilbao, Roberto
    Barricarte, Aurelio
    Navarro, Carmen
    Quiros, José
    Allen, Naomi
    Key, Tim
    Bingham, Sheila
    Khaw, Kay-Tee
    Linseisen, Jakob
    Nagel, Gabriele
    Overvad, Kim
    Tjonneland, Anne
    Olsen, Anja
    Bueno-de-Mesquita, H Bas
    Boshuizen, Hendriek C
    Peeters, Petra H
    Numans, Mattijs E
    Clavel-Chapelon, Francoíse
    Boutron-Ruault, Marie-Christine
    Trichopoulou, Antonia
    Lund, Eiliv
    Offerhaus, Johan
    Jenab, Mazda
    Ferrari, Pietro
    Norat, Teresa
    Riboli, Elio
    González, Carlos A
    Polymorphisms in metabolic genes related to tobacco smoke and the risk of gastric cancer in the European prospective investigation into cancer and nutrition.2006In: Cancer Epidemiology Biomarkers & Prevention, ISSN 1055-9965, Vol. 15, no 12, p. 2427-34Article in journal (Refereed)
  • 473. Agudo, Antonio
    et al.
    Sala, Nária
    Pera, Guillem
    Capella, Gabriel
    Berenguer, Antonio
    García, Nadia
    Palli, Domenico
    Boeing, Heiner
    Del Giudice, Giuseppe
    Saieva, Calogero
    Carneiro, Fatima
    Berrino, Franco
    Sacerdote, Carlotta
    Tumino, Rosario
    Panico, Salvatore
    Berglund, Göran
    Siman, Henrik
    Stenling, Roger
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology. Patologi.
    Hallmans, Göran
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Nutritional Research.
    Martínez, Carmen
    Amiano, Pilar
    Barricarte, Aurelio
    Navarro, Carmen
    Qui, Jose R
    Allen, Naomi
    Key, Tim
    Bingham, Sheila
    Khaw, Kay-Tee
    Linseisen, Jakob
    Nagel, Gabriele
    Overvad, Kim
    Tjonneland, Anne
    Olsen, Anja
    Bueno-de-Mesquita, H Bas
    Boshuizen, Hendriek C
    Peeters, Petra H
    Numans, Mattijs E
    Clavel-Chapelon, Francoíse
    Boutron-Ruault, Marie-Christine
    Trichopoulou, Antonia
    Lund, Eiliv
    Báker, Hendrik
    Jenab, Mazda
    Ferrari, Pietro
    Norat, Teresa
    Riboli, Elio
    González, Carlos A
    No association between polymorphisms in CYP2E1, GSTM1, NAT1, NAT2 and the risk of gastric adenocarcinoma in the European prospective investigation into cancer and nutrition.2006In: Cancer Epidemiology Biomarkers & Prevention, ISSN 1055-9965, Vol. 15, no 5, p. 1043-5Article in journal (Refereed)
  • 474. Agugiaro, G.
    et al.
    Remondino, F.
    Girardi, G.
    von Schwerin, J.
    Richards-Rissetto, Heather
    Umeå University, Faculty of Arts, Humlab.
    De Amicis, R.
    A web-based interactive tool for multi-resolution 3d models of a maya archaeological site2011In: 4TH ISPRS INTERNATIONAL WORKSHOP 3D-ARCH 2011: 3D VIRTUAL RECONSTRUCTION AND VISUALIZATION OF COMPLEX ARCHITECTURES / [ed] Remondino, F; ElHakim, S, 2011, no W16, p. 23-30Conference paper (Refereed)
    Abstract [en]

    Continuous technological advances in surveying, computing and digital-content delivery are strongly contributing to a change in the way Cultural Heritage is "perceived": new tools and methodologies for documentation, reconstruction and research are being created to assist not only scholars, but also to reach more potential users (e.g. students and tourists) willing to access more detailed information about art history and archaeology. 3D computer-simulated models, sometimes set in virtual landscapes, offer for example the chance to explore possible hypothetical reconstructions, while on-line GIS resources can help interactive analyses of relationships and change over space and time. While for some research purposes a traditional 2D approach may suffice, this is not the case for more complex analyses concerning spatial and temporal features of architecture, like for example the relationship of architecture and landscape, visibility studies etc. The project aims therefore at creating a tool, called "QueryArch3D" tool, which enables the web-based visualisation and queries of an interactive, multi-resolution 3D model in the framework of Cultural Heritage. More specifically, a complete Maya archaeological site, located in Copan (Honduras), has been chosen as case study to test and demonstrate the platform's capabilities. Much of the site has been surveyed and modelled at different levels of detail (LoD) and the geometric model has been semantically segmented and integrated with attribute data gathered from several external data sources. The paper describes the characteristics of the research work, along with its implementation issues and the initial results of the developed prototype. [GRAPHICS] .

  • 475. Aguiar, Francisca C.
    et al.
    Segurado, Pedro
    Martins, Maria Joao
    Bejarano, Maria Dolores
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Nilsson, Christer
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Portela, Maria Manuela
    Merritt, David M.
    The abundance and distribution of guilds of riparian woody plants change in response to land use and flow regulation2018In: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 55, no 5, p. 2227-2240Article in journal (Refereed)
    Abstract [en]

    1. Many riparian ecosystems in Mediterranean Europe are affected by land use and flow alteration by dams. We focused on understanding how these stressors and their components affect riparian forests in the region. We asked the following questions: (1) Are there well‐defined, responsive riparian guilds? (2) Do dam‐induced streamflows determine abundance and distribution of riparian guilds? (3) What are the main drivers governing composition and cover of riparian guilds in regulated rivers?

    2. We inventoried the cover of riparian woody species in free‐flowing rivers and downstream of dams. We performed a cluster analysis and ordination to derive riparian guilds, using abundance data from 66 riparian woody species and 26 functional plant traits. We used a reduced set of principal components for the environment, land use and hydrology, and general linear modelling to explore the effect of these factors (separately and combined) on riparian guilds.

    3. We found that: (1) four dominant guilds are responsive to disturbance in southwestern European streams, namely the obligate riparian, water‐stress tolerant, deciduous competitive and Mediterranean evergreen guilds; (2) a set of land use and hydrological variables differentially affect the diverse co‐occurring riparian guilds; (3) frequency and duration of high flow pulses and the low‐flow conditions were major drivers of change in landscapes dominated by intensive agriculture and forestry; (4) storage reservoirs reduced the cover of obligate riparian and Mediterranean evergreen guilds, and increased the abundance of water‐stress tolerant and deciduous competitive guilds, while run‐of‐river dams, having limited water storage, reduced both obligate and deciduous competitive guilds.

    4. Synthesis and applications. Future research in southwestern Europe should address the resilience of riparian guilds and the effects of interacting landscape factors and stressors on guild distribution. Streamflow regulations downstream of reservoirs should focus on specific flow components, namely the magnitude of flows, and frequency and duration of extreme flow events. For successful mitigation of the dam‐induced effects on riparian vegetation, river management plans must incorporate the environmental and land use site‐specific contexts.

  • 476.
    Aguilar, Luis T.
    et al.
    Instituto Politecnico Nacional.
    Boiko, Igor
    University of Calgary.
    Fridman, Leonid
    Universidad Nacional Autonoma de Mexico (UNAM),.
    Freidovich, Leonid
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Inducing oscillations in an Inertia wheel pendulum via Two-relays controller: theory and experiments2009In: American control conference, 2009. ACC 09, Piscataway, NJ: IEEE, Institute of Electrical and Electronics Engineers , 2009, p. 65-70Conference paper (Refereed)
    Abstract [en]

    A tool for generating a self-excited oscillations for an inertia wheel pendulum by means of a variable structure controller is proposed. The original system is transformed into the normal form for exact linearization. The design procedure, based on Describing Function (DF) method, allows for finding the explicit expressions of the two-relays controller gain parameters in terms of the desired frequency and amplitude. Necessary condition for orbital asymptotic stability of the output of the exactly linearized system is derived. Performance issues of the system with self-excited oscillations are validated with experiments.

  • 477. Aguilar, Luis T.
    et al.
    Boiko, Igor M.
    Fridman, Leonid M.
    Freidovich, Leonid B.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Generating oscillations in inertia wheel pendulum via two-relay controller2012In: International Journal of Robust and Nonlinear Control, ISSN 1049-8923, E-ISSN 1099-1239, Vol. 22, no 3, p. 318-330Article in journal (Refereed)
    Abstract [en]

    The problem of generating oscillations of the inertia wheel pendulum is considered. We combine exact feedback linearization with two-relay controller, tuned using frequency-domain tools, such as computing the locus of a perturbed relay system. Explicit expressions for the parameters of the controller in terms of the desired frequency and amplitude are derived. Sufficient conditions for orbital asymptotic stability of the closed-loop system are obtained with the help of the Poincare map. Performance is validated via experiments. The approach can be easily applied for a minimum phase system, provided the behavior of the states of the zero dynamics is of no concern. Copyright (C) 2011 John Wiley & Sons, Ltd.

  • 478.
    Aguilar, Luis T.
    et al.
    CITEDI, National Polytechnic Institute, Tijuana, BC, Mexico.
    Freidovich, Leonid
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Orlov, Yury
    CICESE Research Center, Ensenada, Baja California, Mexico.
    Merida, Jovan
    CITEDI, National Polytechnic Institute, Tijuana, BC, Mexico.
    Performance Analysis of Relay Feedback Position Regulators for Manipulators with Coulomb Friction2013In: Proc. 12th European Control Conference, NEW YORK, NY 10017 USA: IEEE , 2013, p. 3754-3759Conference paper (Refereed)
    Abstract [en]

    The purpose of the paper is to analyze the performance of several global position regulators for robot manipulators with Coulomb friction. All the controllers include a proportional-differential part and a switched part whereas the difference between the controllers is in the way of compensation of the gravitational forces. Stability analysis is also revisited within the nonsmooth Lyapunov function framework for the controllers with and without gravity pre-compensation. Performance issues of the proposed controllers are evaluated in an experimental study of a five degrees-of-freedom robot manipulator. In the experiments, we choose two criteria for performance analysis. In the first set of experiments, we set the same gains to all the controllers. In the second set of experiments, the gains of the controller were chosen such that the work done by the manipulator is similar.

  • 479.
    Aguilar, Ximena
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Folding and interaction studies of subunits in protein complexes2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Proteins function as worker molecules in the cell and their natural environment is crowded. How they fold in a cell-like environment and how they recognize their interacting partners in such conditions, are questions that underlie the work of this thesis.

    Two distinct subjects were investigated using a combination of biochemical- and biophysical methods. First, the unfolding/dissociation of a heptameric protein (cpn10) in the presence of the crowding agent Ficoll 70. Ficoll 70 was used to mimic the crowded environment in the cell and it has been used previously to study macromolecular crowding effects, or excluded volume effects, in protein folding studies. Second, the conformational changes upon interaction between the Mediator subunit Med25 and the transcription factor Dreb2a from Arabidopsis thaliana. Mediator is a transcriptional co-regulator complex which is conserved from yeast to humans. The molecular mechanisms of its action are however not entirely understood. It has been proposed that the Mediator complex conveys regulatory signals from promoter-bound transcription factors (activators/repressors) to the RNA polymerase II machinery through conformational rearrangements.

    The results from the folding study showed that cpn10 was stabilized in the presence of Ficoll 70 during thermal- and chemical induced unfolding (GuHCl). The thermal transition midpoint increased by 4°C, and the chemical midpoint by 0.5 M GuHCl as compared to buffer conditions. Also the heptamer-monomer dissociation was affected in the presence of Ficoll 70, the transition midpoint was lower in Ficoll 70 (3.1 μM) compared to in buffer (8.1 μM) thus indicating tighter binding in crowded conditions. The coupled unfolding/dissociation free energy for the heptamer increased by about 36 kJ/mol in Ficoll. Altogether, the results revealed that the stability effect on cpn10 due to macromolecular crowding was larger in the individual monomers (33%) than at the monomer-monomer interfaces (8%).

    The results from the interaction study indicated conformational changes upon interaction between the A. thaliana Med25 ACtivator Interaction Domain (ACID) and Dreb2a. Structural changes were probed to originate from unstructured Dreb2a and not from the Med25-ACID. Human Med25-ACID was also found to interact with the plant-specific Dreb2a, even though the ACIDs from human and A. thaliana share low sequence homology. Moreover, the human Med25-interacting transcription factor VP16 was found to interact with A. thaliana Med25. Finally, NMR, ITC and pull-down experiments showed that the unrelated transcription factors Dreb2a and

    VP16 interact with overlapping regions in the ACIDs of A. thaliana and human Med25.

    The results presented in this thesis contribute to previous reports in two different aspects. Firstly, they lend support to the findings that the intracellular environment affects the biophysical properties of proteins. It will therefore be important to continue comparing results between in vitro and cell-like conditions to measure the magnitude of such effects and to improve the understanding of protein folding and thereby misfolding of proteins in cells. Better knowledge of protein misfolding mechanisms is critical since they are associated to several neurodegenerative diseases such as Alzheimer’s and Parkinson's. Secondly, our results substantiate the notion that transcription factors are able to bind multiple targets and that they gain structure upon binding. They also show that subunits of the conserved Mediator complex, despite low sequence homologies, retain a conserved structure and function when comparing evolutionary diverged species.

  • 480.
    Aguilar, Ximena
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Blomberg, Jeanette
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Brännström, Kristoffer
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Olofsson, Anders
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Schleucher, Jurgen
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Björklund, Stefan
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Interaction Studies of the Human and Arabidopsis thaliana Med25-ACID Proteins with the Herpes Simplex Virus VP16-and Plant-Specific Dreb2a Transcription Factors2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 5, p. e98575-Article in journal (Refereed)
    Abstract [en]

    Mediator is an evolutionary conserved multi-protein complex present in all eukaryotes. It functions as a transcriptional coregulator by conveying signals from activators and repressors to the RNA polymerase II transcription machinery. The Arabidopsis thaliana Med25 (aMed25) ACtivation Interaction Domain (ACID) interacts with the Dreb2a activator which is involved in plant stress response pathways, while Human Med25-ACID (hMed25) interacts with the herpes simplex virus VP16 activator. Despite low sequence similarity, hMed25-ACID also interacts with the plant-specific Dreb2a transcriptional activator protein. We have used GST pull-down-, surface plasmon resonance-, isothermal titration calorimetry and NMR chemical shift experiments to characterize interactions between Dreb2a and VP16, with the hMed25 and aMed25-ACIDs. We found that VP16 interacts with aMed25-ACID with similar affinity as with hMed25-ACID and that the binding surface on aMed25-ACID overlaps with the binding site for Dreb2a. We also show that the Dreb2a interaction region in hMed25-ACID overlaps with the earlier reported VP16 binding site. In addition, we show that hMed25-ACID/Dreb2a and aMed25-ACID/Dreb2a display similar binding affinities but different binding energetics. Our results therefore indicate that interaction between transcriptional regulators and their target proteins in Mediator are less dependent on the primary sequences in the interaction domains but that these domains fold into similar structures upon interaction.

  • 481.
    Aguilar, Ximena
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Weise, Christoph
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sparrman, Tobias
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wolf-Watz, Magnus
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wittung-Stafshede, Pernilla
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Macromolecular crowding extended to a heptameric system: the co-chaperonin protein 102011In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 50, no 14, p. 3034-3044Article in journal (Refereed)
    Abstract [en]

    Experiments on monomeric proteins have shown that macromolecular crowding can stabilize toward heat perturbation and also modulate native-state structure. To assess the effects of macromolecular crowding on unfolding of an oligomeric protein, we here tested the effects of the synthetic crowding agent Ficoll 70 on human cpn10 (GroES in E. coli), a heptameric protein consisting of seven identical β-barrel subunits assembling into a ring. Using far-UV circular dichroism (CD), tyrosine fluorescence, nuclear magnetic resonance (NMR), and cross-linking experiments, we investigated thermal and chemical stability, as well as the heptamer-monomer dissociation constant, without and with crowding agent. We find that crowding shifts the heptamer-monomer equilibrium constant in the direction of the heptamer. The cpn10 heptamer is both thermally and thermodynamically stabilized in 300 mg/mL Ficoll 70 as compared to regular buffer conditions. Kinetic unfolding experiments show that the increased stability in crowded conditions, in part, is explained by slower unfolding rates. A thermodynamic cycle reveals that in presence of 300 mg/mL Ficoll the thermodynamic stability of each cpn10 monomer increases by over 30%, whereas the interfaces are stabilized by less than 10%. We also introduce a new approach to analyze the spectroscopic data that makes use of multiple wavelengths: this provides robust error estimates of thermodynamic parameters.

  • 482. Aguilera, Adriana Freites
    et al.
    Tolvanen, Pasi
    Heredia, Shuyana
    Muñoz, Marta González
    Samson, Tina
    Oger, Adrien
    Verove, Antoine
    Eränen, Kari
    Leveneur, Sebastien
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Industrial Chemistry & Reaction Engineering, Department of Chemical Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Åbo-Turku, Finland.
    Salmi, Tapio
    Epoxidation of fatty acids and vegetable oils assisted by microwaves catalyzed by a cation exchange resin2018In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 57, no 11, p. 3876-3886Article in journal (Refereed)
    Abstract [en]

    Epoxidation of oleic acid and cottonseed oil was conducted in a semibatch reactor with in-situ-formed percarboxylic acid (peracetic acid or perpropionic acid), using hydrogen peroxide as an oxidizing agent and carboxylic acid (acetic acid or propionic acid) as oxygen carriers. Amberlite IR-120 was implemented as the catalyst. The system was comprised of a loop reactor, where the mixture was pumped through a single-mode cavity in which microwave irradiation was introduced. A heat exchanger was integrated into the system to replace microwave heating, to compare the results obtained via microwave heating versus conventional heating. The catalyst loading effect was studied, as well as the influence of microwave irradiation and the implementation of the SpinChem rotating bed reactor (RBR), in hopes of decreasing the influence of the internal mass transfer. The application of microwave irradiation results in an improvement of the reaction yield in the absence of a catalyst.

  • 483. Aguilo, Francesca
    et al.
    Avagyan, Serine
    Labar, Amy
    Sevilla, Ana
    Lee, Dung-Fang
    Kumar, Parameet
    Lemischka, Ihor R
    Zhou, Betty Y
    Snoeck, Hans-Willem
    Prdm16 is a physiologic regulator of hematopoietic stem cells.2011In: Blood, ISSN 0006-4971, E-ISSN 1528-0020, Vol. 117, no 19Article in journal (Refereed)
    Abstract [en]

    Fetal liver and adult bone marrow hematopoietic stem cells (HSCs) renew or differentiate into committed progenitors to generate all blood cells. PRDM16 is involved in human leukemic translocations and is expressed highly in some karyotypically normal acute myeloblastic leukemias. As many genes involved in leukemogenic fusions play a role in normal hematopoiesis, we analyzed the role of Prdm16 in the biology of HSCs using Prdm16-deficient mice. We show here that, within the hematopoietic system, Prdm16 is expressed very selectively in the earliest stem and progenitor compartments, and, consistent with this expression pattern, is critical for the establishment and maintenance of the HSC pool during development and after transplantation. Prdm16 deletion enhances apoptosis and cycling of HSCs. Expression analysis revealed that Prdm16 regulates a remarkable number of genes that, based on knockout models, both enhance and suppress HSC function, and affect quiescence, cell cycling, renewal, differentiation, and apoptosis to various extents. These data suggest that Prdm16 may be a critical node in a network that contains negative and positive feedback loops and integrates HSC renewal, quiescence, apoptosis, and differentiation.

  • 484.
    Aguilo, Francesca
    et al.
    Umeå University, Faculty of Medicine, Department of Medical Biosciences. Departments of Structural and Chemical Biology, Genetics and Genomic Sciences and Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
    Di Cecilia, Serena
    Walsh, Martin J
    Long Non-coding RNA ANRIL and Polycomb in Human Cancers and Cardiovascular Disease2016In: Long non-coding RNAs in human disease, Springer, 2016, Vol. 394, p. 29-39Chapter in book (Refereed)
    Abstract [en]

    The long non-coding RNA CDKN2B-AS1, commonly referred to as the Antisense Non-coding RNA in the INK4 Locus (ANRIL), is a 3.8-kb-long RNA transcribed from the short arm of human chromosome 9 on p21.3 that overlaps a critical region encompassing three major tumor suppressor loci juxtaposed to the INK4b-ARF-INK4a gene cluster and the methyl-thioadenosine phosphorylase (MTAP) gene. Genome-wide association studies have identified this region with a remarkable and growing number of disease-associated DNA alterations and single nucleotide polymorphisms, which corresponds to increased susceptibility to human disease. Recent attention has been devoted on whether these alterations in the ANRIL sequence affect its expression levels and/or its splicing transcript variation, and in consequence, global cellular homeostasis. Moreover, recent evidence postulates that ANRIL not only can regulate their immediate genomic neighbors in cis, but also has the capacity to regulate additional loci in trans. This action would further increase the complexity for mechanisms imposed through ANRIL and furthering the scope of this lncRNA in disease pathogenesis. In this chapter, we summarize the most recent findings on the investigation of ANRIL and provide a perspective on the biological and clinical significance of ANRIL as a putative biomarker, specifically, its potential role in directing cellular fates leading to cancer and cardiovascular disease.

  • 485.
    Aguilo, Francesca
    et al.
    Icahn School of Medicine at Mount Sinai, New York, NY, USA.
    Li, SiDe
    Balasubramaniyan, Natarajan
    Sancho, Ana
    Benko, Sabina
    Zhang, Fan
    Vashisht, Ajay
    Rengasamy, Madhumitha
    Andino, Blanca
    Chen, Chih-hung
    Zhou, Felix
    Qian, Chengmin
    Zhou, Ming-Ming
    Wohlschlegel, James A
    Zhang, Weijia
    Suchy, Frederick J
    Walsh, Martin J
    Deposition of 5-Methylcytosine on Enhancer RNAs Enables the Coactivator Function of PGC-1α2016In: Cell reports, ISSN 2211-1247, E-ISSN 2211-1247, Vol. 14, no 3, p. 479-492Article in journal (Refereed)
    Abstract [en]

    The Peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) is a transcriptional co-activator that plays a central role in adapted metabolic responses. PGC-1α is dynamically methylated and unmethylated at the residue K779 by the methyltransferase SET7/9 and the Lysine Specific Demethylase 1A (LSD1), respectively. Interactions of methylated PGC-1α[K779me] with the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex, the Mediator members MED1 and MED17, and the NOP2/Sun RNA methytransferase 7 (NSUN7) reinforce transcription, and are concomitant with the m(5)C mark on enhancer RNAs (eRNAs). Consistently, loss of Set7/9 and NSun7 in liver cell model systems resulted in depletion of the PGC-1α target genes Pfkl, Sirt5, Idh3b, and Hmox2, which was accompanied by a decrease in the eRNAs levels associated with these loci. Enrichment of m(5)C within eRNA species coincides with metabolic stress of fasting in vivo. Collectively, these findings illustrate the complex epigenetic circuitry imposed by PGC-1α at the eRNA level to fine-tune energy metabolism.

  • 486.
    Aguilo, Francesca
    et al.
    Umeå University, Faculty of Medicine, Department of Medical Biosciences. Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
    Walsh, Martin J.
    The N6-Methyladenosine RNA modification in pluripotency and reprogramming2017In: Current Opinion in Genetics and Development, ISSN 0959-437X, E-ISSN 1879-0380, Vol. 46, p. 77-82Article, review/survey (Refereed)
    Abstract [en]

    Chemical modifications of RNA provide a direct and rapid way to manipulate the existing transcriptome, allowing rapid responses to the changing environment further enriching the regulatory capacity of RNA. N-6-Methyladenosine(m(6)A) has been identified as the most abundant internal modification of messenger RNA in eukaryotes, linking external stimuli to an intricate network of transcriptional, post-transcriptional and translational processes. M(6)A modification affects a broad spectrum of cellular functions, including maintenance of the pluripotency of embryonic stem cells (ESCs) and the reprogramming of somatic cells into induced pluripotent stem cells (iPSCs). In this review, we summarize the most recent findings on m(6)A modification with special focus on the different studies describing how m(6)A is implicated in ESC self-renewal, cell fate specification and iPSC generation.

  • 487.
    Aguilo, Francesca
    et al.
    Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
    Zakirova, Zuchra
    Nolan, Katie
    Wagner, Ryan
    Sharma, Rajal
    Hogan, Megan
    Wei, Chengguo
    Sun, Yifei
    Walsh, Martin J.
    Kelley, Kevin
    Zhang, Weijia
    Ozelius, Laurie J.
    Gonzalez-Alegre, Pedro
    Zwaka, Thomas P.
    Ehrlich, Michelle E.
    THAP1: Role in Mouse Embryonic Stem Cell Survival and Differentiation2017In: Stem Cell Reports, ISSN 2213-6711, Vol. 9, no 1, p. 92-107Article in journal (Refereed)
    Abstract [en]

    THAP1 (THAP [Thanatos-associated protein] domain-containing, apoptosis-associated protein 1) is a ubiquitously expressed member of a family of transcription factors with highly conserved DNA-binding and protein-interacting regions. Mutations in THAP1 cause dystonia, DYT6, a neurologic movement disorder. THAP1 downstream targets and the mechanism via which it causes dystonia are largely unknown. Here, we show that wild-type THAP1 regulates embryonic stem cell (ESC) potential, survival, and proliferation. Our findings identify THAP1 as an essential factor underlying mouse ESC survival and to some extent, differentiation, particularly neuroectodermal. Loss of THAP1 or replacement with a disease-causing mutation results in an enhanced rate of cell death, prolongs Nanog, Prdm14, and/or Rex1 expression upon differentiation, and results in failure to upregulate ectodermal genes. ChIP-Seq reveals that these activities are likely due in part to indirect regulation of gene expression.

  • 488. Aguilo, Francesca
    et al.
    Zhang, Fan
    Sancho, Ana
    Fidalgo, Miguel
    Di Cecilia, Serena
    Vashisht, Ajay
    Lee, Dung-Fang
    Chen, Chih-Hung
    Rengasamy, Madhumitha
    Andino, Blanca
    Jahouh, Farid
    Roman, Angel
    Krig, Sheryl R
    Wang, Rong
    Zhang, Weijia
    Wohlschlegel, James A
    Wang, Jianlong
    Walsh, Martin J
    Coordination of m(6)A mRNA Methylation and Gene Transcription by ZFP217 Regulates Pluripotency and Reprogramming.2015In: Cell Stem Cell, ISSN 1934-5909, E-ISSN 1875-9777, Vol. 17, no 6, p. 689-704Article in journal (Refereed)
    Abstract [en]

    Epigenetic and epitranscriptomic networks have important functions in maintaining the pluripotency of embryonic stem cells (ESCs) and somatic cell reprogramming. However, the mechanisms integrating the actions of these distinct networks are only partially understood. Here we show that the chromatin-associated zinc finger protein 217 (ZFP217) coordinates epigenetic and epitranscriptomic regulation. ZFP217 interacts with several epigenetic regulators, activates the transcription of key pluripotency genes, and modulates N6-methyladenosine (m(6)A) deposition on their transcripts by sequestering the enzyme m(6)A methyltransferase-like 3 (METTL3). Consistently, Zfp217 depletion compromises ESC self-renewal and somatic cell reprogramming, globally increases m(6)A RNA levels, and enhances m(6)A modification of the Nanog, Sox2, Klf4, and c-Myc mRNAs, promoting their degradation. ZFP217 binds its own target gene mRNAs, which are also METTL3 associated, and is enriched at promoters of m(6)A-modified transcripts. Collectively, these findings shed light on how a transcription factor can tightly couple gene transcription to m(6)A RNA modification to ensure ESC identity.

  • 489. Aguilo, Francesca
    et al.
    Zhou, Ming-Ming
    Walsh, Martin J
    Long noncoding RNA, polycomb, and the ghosts haunting INK4b-ARF-INK4a expression.2011In: Cancer Research, ISSN 0008-5472, E-ISSN 1538-7445, Vol. 71, no 16Article in journal (Refereed)
    Abstract [en]

    Polycomb group proteins (PcG) function as transcriptional repressors of gene expression. The important role of PcG in mediating repression of the INK4b-ARF-INK4a locus, by directly binding to the long noncoding RNA (lncRNA) transcript antisense noncoding RNA in the INK4 locus (ANRIL), was recently shown. INK4b-ARF-INK4a encodes 3 tumor-suppressor proteins, p15(INK4b), p14(ARF), and p16(INK4a), and its transcription is a key requirement for replicative or oncogene-induced senescence and constitutes an important barrier for tumor growth. ANRIL gene is transcribed in the antisense orientation of the INK4b-ARF-INK4a gene cluster, and different single-nucleotide polymorphisms are associated with increased susceptibility to several diseases. Although lncRNA-mediated regulation of INK4b-ARF-INK4a gene is not restricted to ANRIL, both polycomb repressive complex-1 (PRC1) and -2 (PRC2) interact with ANRIL to form heterochromatin surrounding the INK4b-ARF-INK4a locus, leading to its repression. This mechanism would provide an increased advantage for bypassing senescence, sustaining the requirements for the proliferation of stem and/or progenitor cell populations or inappropriately leading to oncogenesis through the aberrant saturation of the INK4b-ARF-INK4a locus by PcG complexes. In this review, we summarize recent findings on the underlying epigenetic mechanisms that link PcG function with ANRIL, which impose gene silencing to control cellular homeostasis as well as cancer development.

  • 490. Aguiló, Francesca
    et al.
    Camarero, Nuria
    Relat, Joana
    Marrero, Pedro F
    Haro, Diego
    Transcriptional regulation of the human acetoacetyl-CoA synthetase gene by PPARgamma.2010In: Biochemical Journal, ISSN 0264-6021, E-ISSN 1470-8728, Vol. 427, no 2Article in journal (Refereed)
    Abstract [en]

    In the cytosol of lipogenic tissue, ketone bodies are activated by AACS (acetoacetyl-CoA synthetase) and incorporated into cholesterol and fatty acids. AACS gene expression is particularly abundant in white adipose tissue, as it is induced during adipocyte differentiation. In order to elucidate the mechanism controlling the gene expression of human AACS and to clarify its physiological role, we isolated the human promoter, characterized the elements required to initiate transcription and analysed the expression of the gene in response to PPARgamma (peroxisome-proliferator-activated receptor gamma), an inducer of adipogenesis. We show that the human AACS promoter is a PPARgamma target gene and that this nuclear receptor is recruited to the AACS promoter by direct interaction with Sp1 (stimulating protein-1).

  • 491.
    Aguirre Nunez, William
    Umeå University, Faculty of Social Sciences, Umeå School of Business.
    Should I stay or Should I go?: –En studie om småföretagares val att göra digitala marknadsföringssatsningar på Internet2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med studien är att få en ökad kunskap om varför småföretag väljer att börja medmarknadsföringsinsatser på Internet. Helt enkelt få insikt om vad som drivit småföretag att ta steget till att implementera Internet till sin verksamhet. För att se hur det hör ihop med att valav aktiviteter och verktyg som används i marknadsföringssyfte. Även se om det görs någon form av uppföljning av de olika processerna.

  • 492.
    Agvald, Liv
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Sports medicine.
    Fysisk aktivitetsnivå hos barn i årskurs 3: En accelerometerstudie2018Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Introduction: The importance of physical activity is well investigated, but the knowledge regarding the physical activity of younger children is limited. Accelerometers have proved to be a valid method to measure physical activity in children.

    Purpose: The purpose of this study was to investigate the total level of physical activity (relative to recommended level) in children in grade three at a school in northern Sweden. Furthermore, the study investigated whether there are any differences in physical activity based on gender or participation in organized sports.

    Method: Forty children participated in the study. Their level of physical activity was measured using tri-accelerometry technology during one week. Each participant also completed a short questionnaire regarding their level of physical activity.

    Results: No significant difference was found in the level of physical activity in relation to gender or participation in organized sports. All but one participant reached the recommended level of daily activity.

    Discussion: Based on the study, children in grade three appear to be sufficiently active to achieve the daily level of activity, a positive result in spite of the alarming reports of increased sedentary behavior among children. Intensified studies are needed to see if these results recur in a broader context.

  • 493.
    Agvik, Simon
    Umeå University, Faculty of Science and Technology, Department of Physics.
    A deformable terrain model in multi-domain dynamics using elastoplastic constraints: An adaptive approach2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Achieving realistic simulations of terrain vehicles in their work environment does not only require a careful model of the vehicle itself but the vehicle's interactions with the surroundings are equally important. For off-road ground vehicles the terrain will heavily affect the behaviour of the vehicle and thus puts great demands on the terrain model.

    The purpose of this project has been to develop and evaluate a deformable terrain model, meant to be used in real-time simulations with multi-body dynamics. The proposed approach is a modification of an existing elastoplastic model based on linear elasticity theory and a capped Drucker-Prager model, using it in an adaptive way. The original model can be seen as a system of rigid bodies connected by elastoplastic constraints, representing the terrain. This project investigates if it is possible to create dynamic bodies just when it is absolutely necessary, and store information about possible deformations in a grid.

    Two methods used for transferring information between the dynamic bodies and the grid have been evaluated; an interpolating approach and a discrete approach. The test results indicate that the interpolating approach is preferable, with better stability to an equal performance cost. However, stability problems still exist that have to be solved if the model should be useful in a commercial product.

  • 494.
    Agyeman, Stephen Kwaning
    Umeå University, Faculty of Social Sciences, Umeå School of Business.
    Challenges facing venture capitalists in developing economies: An empirical study about venture capital industry in Ghana2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 495. Ahad, Abdul
    et al.
    Keech, Olivier
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Sjödin, Andreas
    Lindén, Pernilla
    Brouwer, Bastiaan
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Stenlund, Hans
    Moritz, Thomas
    Jansson, Stefan
    Gardeström, Per
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Comparison between leaves from darkened plants and individually-darkened leaves reveals differential metabolic strategies in response to darknessManuscript (preprint) (Other academic)
  • 496. Ahad, Abdul
    et al.
    Keech, Olivier
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre.
    Sjödin, Andreas
    Stenlund, Hans
    Moritz, Thomas
    Jansson, Stefan
    Gardeström, Per
    Leaf metabolism during dark induced senescence in Arabidopsis: integrating metabolomics and transcriptomicsManuscript (Other academic)
  • 497.
    Ahad, Abdul
    et al.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Nick, Peter
    Actin is bundled in activation-tagged tobacco mutants that tolerate aluminum2007In: Planta, ISSN 0032-0935, E-ISSN 1432-2048, Vol. 225, no 2, p. 451-468Article in journal (Refereed)
    Abstract [en]

    A panel of aluminum-tolerant (AlRes) mutants was isolated by protoplast-based T-DNA activation tagging in the tobacco cultivar SR1. The mutants fell into two phenotypic classes: a minority of the mutants were fertile and developed similarly to the wild type (type I), the majority was male-sterile and grew as semi-dwarfs (type II). These traits, along with the aluminum tolerance, were inherited in a monogenic dominant manner. Both types of mutants were characterized by excessive bundling of actin microfilaments and by a strongly increased abundance of actin, a phenotype that could be partially phenocopied in the wild type by treatment with aluminum chloride. The actin bundles could be dissociated into finer strands by addition of exogenous auxin in both types of mutants. However, actin microfilaments and leaf expansion were sensitive to blockers of actin assembly in the wild type and in the mutants of type I, whereas they were more tolerant in the mutants of type II. The mutants of type II displayed a hypertrophic development of vasculature, manifest in form of supernumerary leaf veins and extended xylem layers in stems and petioles. Whereas mutants of type I were characterized by a normal, but aluminum-tolerant polar auxin-transport, auxin-transport was strongly promoted in the mutants of type II. The phenotype of these mutants is discussed in terms of reduced endocytosis leading, concomitantly with aluminum tolerance, to changes in polar auxin transport.

  • 498.
    Ahangari, Alebtekin
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health.
    Chronic pelvic pain: 8 years after the 2006 WHO systematic review2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 499.
    Ahangari, Alebtekin
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health.
    Pain and Alcohol Consumption among Elderly: Evidences from WHO Study on global AGEing and adult health (Wave 1)2014Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
  • 500.
    Ahangari, Alebtekin
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health.
    Prevalence of Chronic Pelvic Pain Among Women: An Updated Review2014In: Pain Physician, ISSN 1533-3159, E-ISSN 2150-1149, Vol. 17, no 2, p. E141-E147Article, review/survey (Refereed)
    Abstract [en]

    Background: Chronic pelvic pain (CPP), defined as a noncyclical pain lasting for more than 6 months can lead to lower physical performance and quality of life in women. CPP is a worldwide problem affecting women of all ages. However, health care professionals and researchers, due to its complex nature and the lack of knowledge surrounding the condition, frequently neglect CPP. Subsequently, basic data and knowledge regarding CPP remain incomplete. Objective: To update the review of the worldwide estimation of the CPP prevalence considering the World Health Organization systematic review by Latthe et al in 2006 as point of departure. Study Design: A systematic review of CPP prevalence studies. Method: Electronic search was performed to find related articles through PubMed between 2005 and 2012 based on the PRISMA statement (2009). Results: From 140 studies, only 7 studies were about CPP prevalence. Their study design consisted of 3 cross sectional studies, one population based mailing questionnaire study, one survey study (computer assisted telephone interview), one data analysis by questionnaire, and one prospective community based study. Limitations: Paucity of population based studies in addition to probability of existence of studies at the local level with limited access to worldwide databases, lack of consensus about definition of CPP among researchers and therapists, and non-inclusion of CPP related key words in databases such as PubMed. Conclusion: Based on these articles, prevalence in general ranged between 5.7% and 26.6%. There were many countries and regions without basic data in the field of CPP. This review shows the paucity of studies, especially multidisciplinary researches with multifactorial views on CPP. Multidisciplinary studies would provide more reliable data for estimating the prevalence of CPP and its psycho-socioeconomic burden, as well as finding its etiologies and characteristics. This would be the first step towards better treatment and care for women with CPP.

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