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  • 1. Behrens, Jane W.
    et al.
    von Friesen, Lisa W.
    Brodin, Tomas
    Ericsson, Philip
    Hirsch, Philipp Emanuel
    Persson, Anders
    Sundelin, Anna
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    van Deurs, Mikael
    Nilsson, P. Anders
    Personality- and size-related metabolic performance in invasive round goby (Neogobius melanostomus)2020In: Physiology and Behavior, ISSN 0031-9384, E-ISSN 1873-507X, Vol. 215, article id 112777Article in journal (Refereed)
    Abstract [en]

    Differences between individuals in behavioral type (i.e. animal personality) are ecologically and evolutionarily important because they can have significant effects on fitness components such as growth and predation risk. In the present study we are used the invasive round goby (Neogobius melanostomus) from an established population in controlled experiments to examine the relationships among personality, metabolic performance, and growth rate (inferred as size-at-age). Boldness was measured as the time to return to normal behavior after a simulated predator attack, where fish with shorter freezing times were categorized as "bold" and fish with longer times were categorized as "shy." We show that bold fish have significantly higher standard metabolic rate (SMR) than their shy conspecifics, whereas there was no difference between personality types in their maximum metabolic rate (MMR) or aerobic scope (AS). Bold fish furthermore had a smaller size-at-age as compared to shy fish. Together this provides evidence of a metabolic underpinning of personality where the high-SMR bold fish require more resources to sustain basic life functions than their low-SMR shy conspecifics, indicating that bold round goby from established populations with high densities (and high competition for food) pay a price of reduced growth rate.

  • 2. Bäckman, Lars
    et al.
    Lindenberger, Ulman
    Li, Shu-Chen
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Linking cognitive aging to alterations in dopamine neurotransmitter functioning: Recent data and future avenues2010In: Neuroscience and Biobehavioral Reviews, ISSN 0149-7634, E-ISSN 1873-7528, Vol. 34, no 5, p. 670-677Article, review/survey (Refereed)
    Abstract [en]

    Molecular-imaging studies of dopaminergic neurotransmission measure biomarkers of dopamine (DA), such as the DA transporter and D(1) and D(2) receptor densities in the living brain. These studies indicate that individual differences in DA functions are linked to cognitive performance irrespective of age, and serve as powerful mediators of age-related decline in executive functioning, episodic memory, and perceptual speed. This focused review targets several recent findings pertaining to these relationships. Specifically, we discuss novel evidence concerning (a) the role of DA in within-person cognitive variability; (b) age-related differences in DA release during cognitive processing; (c) DA release following cognitive training in younger and older adults; and (d) the relationship between DA and task-induced functional brain activity. Based on these lines of empirical inquiry, we outline a series of avenues for future research on aging, DA, and cognition.

  • 3. Collis, Ken
    et al.
    Roby, Daniel D.
    Larson, Keith W.
    Department of Fisheries and Wildlife, 104 Nash Hall, Oregon State University, Corvallis, OR, 97331, USA; Evolutionary Ecology, Lund University, Sølvegatan 37, 223 62 Lund, Sweden.
    Adrean, Lindsay J.
    Nelson, S. Kim
    Evans, Allen F.
    Hostetter, Nathan
    Battaglia, Dan
    Lyons, Donald E.
    Marcella, Tim
    Patterson, Allison
    Trends in Caspian Tern Nesting and Diet in San Francisco Bay: Conservation Implications for Terns and Salmonids2012In: Waterbirds (De Leon Springs, Fla.), ISSN 1524-4695, E-ISSN 1938-5390, Vol. 35, no 1, p. 25-34Article in journal (Refereed)
    Abstract [en]

    Colony size, nesting ecology and diet of Caspian Terns (Hydroprogne caspia) were investigated in the San Francisco Bay area (SFBA) during 2003-2009 to assess the potential for conservation of the tern breeding population and possible negative effects of predation on survival of juvenile salmonids (Oncorhyn-chusspp.). Numbers of breeding Caspian Terns declined 36% from 2003 to 2009, mostly due to abandonment of the Knight Island colony and decline of the Brooks Island colony, the two largest colonies in the SFBA. Concurrently, nesting success declined 69% associated with colony site characteristics such as (a) quality and quantity of nesting substrate, (b) vulnerability to nest predators, (c) displacement by other colonial waterbirds and (d) human disturbance. Marine fishes were the predominant prey in tern diets from the SFBA; however, diet composition varied among colonies. Juvenile salmonids comprised 22.9% of the diet of terns nesting in the North Bay, 5.3% of diet of terns nesting in the Central Bay, and 0.1% in the South Bay. Construction or restoration of nesting islands in the South Bay may help maintain and restore breeding Caspian Terns without enhancing mortality of salmonid stocks of conservation concern.

  • 4.
    Franzén, Louise
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Manipulation of monoamines and effects on behavior in crickets.2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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  • 5.
    Hatchett, William
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    The road toward sympatric speciation in whitefish.: The effects of divergent selection on European whitefish (Coregonus lavaretus) size and behavior, and effects on zooplankton communities.2015Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    For almost every organism there are large gaps in our knowledge about the processes that leads to speciation. The changes an organism undergoes before divergence has occurred have remained a mystery, as it is difficult to say whether or not a species is going to diverge and when. To investigate this unknown the European whitefish (Coregonus lavaretus) and the northern pike (Esox lucius) were studied, as they produce a repeatable and predictable pattern of speciation in sympatry. To investigate the changes in phenotypes and behaviour in whitefish that precedes divergence, two lake populations were examined, Gräsvattnet and Ringsjön. Gräsvattnet was used as a control, with a population of whitefish but an absence of pike, whereas Ringsjön has a population of whitefish that invaded from Gräsvattnet and a pike population. The presence of pike presumably exerts divergent selection on the whitefish population. Fish and zooplankton were surveyed in both lakes from 1970 to the present day, which allows us to compare how whitefish populations and their resources change in the presence and absence of pike. The results found in Ringsjön show; (1) a change in habitat use, (2) a change in diet from pelagic to benthic, (3) an increase in the relationship between individual body size and diet and (4) a decrease in average size over the course of the study. (1)The presence of pike is believed to have forced the whitefish into the pelagic which could be seen in the result, with an increase in individuals caught in the pelagic. (2) The change in diet is thought to be caused by a resource competition created by individuals being forced to use the pelagic. Although insignificant this led to an overall reduction in zooplankton abundance by almost 40% which could have intensified competition. The resource competition could then have been intensified further by the change in composition of zooplankton relative abundance. (3) The increase in relationship between individual body size and diet is thought to increase due to the resource competition between smaller and larger individuals in the pelagic. Smaller individuals are better competitors than larger individuals for pelagic resource which could have led to the larger individuals switching to a more benthic diet. (4) The decrease in average size is thought to be caused by negative selection for larger individuals. Larger individuals have switched to a more benthic diet, and although the individuals are larger they still face the risk of predation in the littoral zone as they have not outgrown the gape size of the pike. This could have led to the average size reduction that may be the first steps in speciation, and ultimately leading to the divergence of two morphs by sympatric speciation in Ringsjön. In Gräsvattnet over the course of the study there were few and small changes in whitefish size, zooplankton relative abundance in the diet and in the environment. The results in Gräsvattnet could however suggest resource competition for benthic resources. Although resource competition is thought to be an important factor in the speciation of whitefish, without predation pressure no speciation occurs. This result could suggest the importance of predation pressure in the speciation of whitefish. 

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  • 6. Karczmarski, Leszek
    et al.
    Wursig, Bernd
    Gailey, Glenn
    Larson, Keith W.
    Midway Atoll National Wildlife Refuge, Pacific Remote Islands NWR Complex, U.S. Fish and Wildlife Service, Honolulu, USA.
    Vanderlip, Cynthia
    Spinner dolphins in a remote Hawaiian atoll: social grouping and population structure2005In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 16, no 4, p. 675-685Article in journal (Refereed)
    Abstract [en]

    Spinner dolphins (Stenella longirostris) commonly use inshore island and atoll habitats for daytime rest and social interactions and forage over deep waters at night. In Hawaii, they occur throughout the archipelago. We applied photoidentification mark-recapture techniques to study the population structure of spinner dolphins associated with remote Midway Atoll, far-western Hawaii. At Midway, spinner dolphins live in stable bisexually bonded societies of long-term associates, with strong geographic fidelity, no obvious fission-fusion, and limited contacts with other populations. Their large cohesive groups change little over time and are behaviorally/socially discrete from other spinner dolphin groups. This social pattern differs considerably from the fluid fission-fusion model proposed previously for spinner dolphins associated with a large island habitat in the main Hawaiian Archipelago. These differences correspond to geographic separation and habitat variation. While in the main islands there are several daytime resting places available at each island habitat; in far-western Hawaii, areas of suitable habitat are limited and separated by large stretches of open pelagic waters with potentially high risk of shark predation. We hypothesize that with deepwater food resources in close proximity and other atolls relatively far away for easy (day-to-day) access, it is energetically more beneficial in the remote Hawaiian atolls to remain “at home” than to travel to other atolls, so there is stability instead of variability; there is no fission-fusion effect. Thus, the geographic isolation and small size of remote atolls trigger a process in which the fluidity of the fission-fusion spinner dolphin society is replaced with long-term group fidelity and social stability.

  • 7.
    Larson, Keith W.
    Lund University.
    Hybrid zone dynamics, assortative mating, and migratory programmes in a willow warbler migratory divide2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis I will compare and contrast the two willow warbler subspecies (Phylloscopus trochilus trochilus and P. t. acredula) with differing migratory phenotypes (or "migratype") in the context of their migratory divide and hybrid zone in central Sweden. Their migratory programs differ in the direction and distance traveled during migration. The "northern" willow warblers migrate south-southeast through the Balkan Peninsula to winter in eastern Africa. The "southern" willow warbler migrates southwest through the Iberian Peninsula to winter in western Africa. In this thesis I will also explore the consequences of hybridization for these two very closely related subspecies where they meet in central Sweden. In the first paper I investigate the role of population abundance in determining the location of the hybrid zone. Specifically, is there a region of low abundance associated with the hybrid zone? Further, is the hybrid zone located on an environmental gradient which might suggest that breeding ground environmental conditions are responsible for the lower abundance? This lower abundance may reflect the unsuitability of habitats along the environmental gradient for either parental or hybrid offspring. In my second paper, I ask if there are population specific differences in their wintering moult ecology that can be elucidated from diet derived stable isotope patterns in their winter moulted primary flight feathers? The third paper addresses the important question, does assortative mating lead to reproductive isolation or do these very similar subspecies hybridize and produce offspring? In my fourth paper, I ask does local adaptation to environmental conditions, such as temperature extremes and the short growing season, in mountain populations of willow warblers explain the apparent distribution of the “northern-allele” for the AFLP derived genetic marker WW1? Finally, in the fifth paper, I conduct a detailed analysis of phenotypic traits at 50 sites across the hybrid zone, including 35 sites visited more than once. Here I ask, does lower abundances in the west of the hybrid zone predict the zone to be wider in the west than in the east? Further, using data from repeated visits to sites across the zone, we predict low repeatabilities for migratory associated traits that would suggest that high annual turn-over in migratypes occupying the zone. For future efforts to understand hybrid zone dynamics, it will be essential to develop genetic markers that allow one to separate each parental migratypes, hybrids, and back-crosses. Once genetic markers allow the identification of hybrid offspring, orientation experiments should be conducted to elucidate migratory directional preferences that would support our hypothesis that hybrids take an intermediate migratory direction to their parental migratypes. This intermediate direction could be a significant cost to hybrid fitness, as this route would require they cross the Mediterranean Sea and Sahara Desert at their widest points.

  • 8.
    Mossing, Torgny
    Umeå University, Faculty of Science and Technology.
    Seasonal variations in general activity, behaviour and cutaneous glandular structures in reindeer (Rangifer tarandus L.)1980Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The locomotor activity of the reindeer is separated into a diurnal and a nocturnal phase which, in turn, consists of a  number of short-term activity bursts. The onset and termination  of diurnal and nocturnal activity are largely in synchrony  with sunrise and sunset. Since the diurnal phase is  longer, total activity is dependent on the photoperiod. Total  activity as well as the number of activity bursts is greater  in Jùne with continuous daylight than in December with 6  hours daylight. In winter, reindeer spent less time feeding  but more time ruminating and resting *than in summer. Synchronization  between individuals was also greatest in winter. It  is concluded that the described changes in the activity  pattern are due to an endogenous component and that this component  further controls food consumption and energy balance  of the reindeer.  Seasonal variations in behavioural patterns are described.  Several specific rutting behavioürs, sexual and agonostic,  emerge in the male during the prerut and persist until after  the rut. The preorbital gland is enlarged and secretory activity  is evident. The rut is cha'tabterized by the sudden appearance  of an odour in the breath of mature males followed a few  later by a strong odour in the urine. These odours persist for  a short time during the most intense period of rut. The amount  of androgen rizes sharply and reaches peak concentrations in  late September - early October, decreasing thereafter. The  described behavioural cues occur with a certain constancy in  time in concecutive seasons.  A quantification of the amounts of secretory epithelia in preorbital,  interdigital, caudal and tarsal glands reveals that  only the preorbital gland is subjected to any seasonal and  sexual variation. The apocrine epithelium in this gland is  most developed in mature males during the rutting season and  seems to be dependent upon the presence of an elevated androgen  concentration. The tarsal gland is the least developed  gland while the interdigital and caudal glands are more welldeveloped  and structurally complex. Scattered apocrine glands  are only developed on the legs, the ventral body, oral angle  and in the rump patch.

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  • 9. Pratt, Stephen C
    et al.
    Sumpter, David JT
    Umeå University, Faculty of Science and Technology, Department of mathematics.
    Mallon, Eamonn B
    Franks, Nigel R
    An agent-based model of collective nest choice by the ant Temnothorax albipennis2005In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 70, no 5, p. 1023-1036Article in journal (Refereed)
    Abstract [en]

    Colonies of the ant Temnothorax (formerly Leptothorax) albipennis can collectively choose the best of several nest sites, even when many of the active ants who organize the move visit only one site. Previous studies have suggested that this ability stems from the ants' strategy of graded commitment to a potential home. On finding a site, an ant proceeds from independent assessment, to recruiting fellow active ants via slow tandem runs, to bringing the passive bulk of the colony via rapid transports. Assessment duration varies inversely with site quality, and the switch from tandem runs to transports requires that a quorum of ants first be summoned to the site. These rules may generate a collective decision, by creating and amplifying differential population growth rates among sites. We test the importance of these and other known behavioural rules by incorporating them into an agent-based model. All parameters governing individual behaviour were estimated from videotaped emigrations of individually marked ants given a single nest option of either good or mediocre quality. The time course of simulated emigrations and the distribution of behaviour across ants largely matched these observations, except for the speed with which the final transport phase was completed, and the overall emigration speed of one particularly large colony. The model also predicted the prevalence of splitting between sites when colonies had to choose between two sites of different quality, although it correctly predicted the degree of splitting in only four of six cases. It did not fully capture variance in colony performance, but it did predict the emergence of variation in individual behaviour, despite the use of identical parameter values for all ants. The model shows how, with adequate empirical data, the algorithmic form of a collective decision-making mechanism can be captured.

  • 10.
    Sundström, Peter
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Multiple sclerosis in Västerbotten county, northern Sweden2003Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    One out of several distinguishing features of multiple sclerosis (MS) is the epidemiological variation of geographic distribution. Population-based studies on the prevalence and incidence of MS in Sweden have previously been performed only in Göteborg. Another feature of MS is the clinical variation between individuals. To a large extent data on the clinical characteristics of MS come from studies on cases frequenting MS clinics and therefore, may be biased. Also rare are population-based studies of the consequences of MS-related incapacity on socio­economic factors. As for MS aetiology, both environment and genes are involved. Human herpesviruses are often the main suspected environmental aetiological agents.

    Our aim was to estimate the prevalence of MS in Västerbotten County for 1 January 1990, the incidence during a 10-year period 1988-97, and the prevalence 31 December 1997; and also to present detailed clinical data including onset symptoms and the disability distribution for the latter two MS populations. Furthermore, we wanted to estimate the prevalence of sick leave, professional assistance, and housing; and also, to study the risk factors for sick leave. In order to investigate the association between MS and human herpesviruses, samples were identified in two regional population-based serumbank registers. This linkage identified samples collected from before MS-onset in 73 MS cases and after MS onset in 161 cases The prevalence and incidence populations were identified through multiple sources. Diagnostic ascertainment, the reliability of clinical data, and additional information were assured from a questionnaire with follow-up interview and neurological examination.

    The onset adjusted crude prevalence of MS was 125/100,000 (95% CI: 112-140) in January 1990, and 154/100,000 (95% Cl: 139-170) in December 1997. The increase was mainly attributable to a higher incidence than mortality. The crude incidence rate 1988-97 was 5.2/100,000 (95% CI: 4.4-6.2). The disability distribution in the 1997 prevalence population in Västerbotten was compared to the disability distribution in a Canadian MS population, which has been used for publications on the natural history of MS. One difference from the Canadian studies appears to be the better recognition of cases with more benign disease. Nevertheless almost half of prevalent MS cases aged 18-64 years were fully sick-listed, and one-fourth of all prevalent cases received professional assistance. High disability level was the strongest predictor for sick leave. All MS cases showed signs of past Epstein-Barr virus (EBV) infection. High activity to EBV (EBNA-1 but not VCA) and human herpesvirus 6 (HHV-6) significantly (borderline significance for HHV-6) increased the risk to develop MS.

    These estimates show that Västerbotten County is a high risk area for MS. Both incidence and prevalence were significantly higher when compared to estimates from Göteborg. The comparison with the Canadian MS population shows that MS might be a slightly more benign disease than previously recognized. Still, the consequences of MS regarding socio-economic aspects are considerable. We suggest that EBV is a prerequisite for the development of MS. Individuals that will develop MS exhibit an altered immune response against the EBV virus characterised by high activities to EBNA-1 in the absence of high VCA activities, this being most pronounced in the five-year period preceding MS onset. A pathogenetic role is suggested for EBV and remains possible also for HHV-6.

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  • 11.
    Wittmann, Walter
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    McLennan, Ian S.
    The bed nucleus of the stria terminalis has developmental and adult forms in mice, with the male bias in the developmental form being dependent on testicular AMH2013In: Hormones and Behavior, ISSN 0018-506X, E-ISSN 1095-6867, Vol. 64, no 4, p. 605-610Article in journal (Refereed)
    Abstract [en]

    Canonically, the sexual dimorphism in the brain develops perinatally, with adult sexuality emerging due to the activating effects of pubescent sexual hormones. This concept does not readily explain why children have a gender identity and exhibit sex-stereotypic behaviours. These phenomena could be explained if some aspects of the sexual brain networks have childhood forms, which are transformed at puberty to generate adult sexuality. The bed nucleus of stria terminalis (BNST) is a dimorphic nucleus that is sex-reversed in transsexuals but not homosexuals. We report here that the principal nucleus of the BNST (BNSTp) of mice has developmental and adult forms that are differentially regulated. In 20-day-old prepubescent mice, the male bias in the principal nucleus of the BNST (BNSTp) was moderate (360 +/- 6 vs 288 +/- 12 calbindin(+ve) neurons, p < 0.0001), and absent in mice that lacked a gonadal hormone, AMH. After 20 days, the number of BNSTp neurons increased in the male mice by 25% (p < 0.0001) and decreased in female mice by 15% (p = 0.0012), independent of AMH. Adult male AMH-deficient mice had a normal preference for sniffing female pheromones (soiled bedding), but exhibited a relative disinterest in both male and female pheromones. This suggests that male mice require AMH to undergo normal social development. The reported observations provide a rationale for examining AMH levels in children with gender identity disorders and disorders of socialization that involve a male bias.

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