| 1. |
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| 2. |
- Blanton, Michael R., et al.
(författare)
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Sloan Digital Sky Survey IV : Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
- 2017
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Ingår i: Astronomical Journal. - : IOP Publishing Ltd. - 0004-6256 .- 1538-3881. ; 154:1
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Tidskriftsartikel (refereegranskat)abstract
- We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and. high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z similar to 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z similar to 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs. and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the. Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July.
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| 3. |
- Taal, H. Rob, et al.
(författare)
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Common variants at 12q15 and 12q24 are associated with infant head circumference
- 2012
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 44:5, s. 532-538
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Tidskriftsartikel (refereegranskat)abstract
- To identify genetic variants associated with head circumference in infancy, we performed a meta-analysis of seven genome-wide association studies (GWAS) (N = 10,768 individuals of European ancestry enrolled in pregnancy and/or birth cohorts) and followed up three lead signals in six replication studies (combined N = 19,089). rs7980687 on chromosome 12q24 (P = 8.1 x 10(-9)) and rs1042725 on chromosome 12q15 (P = 2.8 x 10(-10)) were robustly associated with head circumference in infancy. Although these loci have previously been associated with adult height(1), their effects on infant head circumference were largely independent of height (P = 3.8 x 10(-7) for rs7980687 and P = 1.3 x 10(-7) for rs1042725 after adjustment for infant height). A third signal, rs11655470 on chromosome 17q21, showed suggestive evidence of association with head circumference (P = 3.9 x 10(-6)). SNPs correlated to the 17q21 signal have shown genome-wide association with adult intracranial volume(2), Parkinson's disease and other neurodegenerative diseases(3-5), indicating that a common genetic variant in this region might link early brain growth with neurological disease in later life.
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| 4. |
- van der Valk, Ralf J P, et al.
(författare)
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A novel common variant in DCST2 is associated with length in early life and height in adulthood.
- 2015
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Ingår i: Human molecular genetics. - : Oxford University Press (OUP). - 1460-2083 .- 0964-6906. ; 24:4, s. 1155-68
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Tidskriftsartikel (refereegranskat)abstract
- Common genetic variants have been identified for adult height, but not much is known about the genetics of skeletal growth in early life. To identify common genetic variants that influence fetal skeletal growth, we meta-analyzed 22 genome-wide association studies (Stage 1; N = 28 459). We identified seven independent top single nucleotide polymorphisms (SNPs) (P < 1 × 10(-6)) for birth length, of which three were novel and four were in or near loci known to be associated with adult height (LCORL, PTCH1, GPR126 and HMGA2). The three novel SNPs were followed-up in nine replication studies (Stage 2; N = 11 995), with rs905938 in DC-STAMP domain containing 2 (DCST2) genome-wide significantly associated with birth length in a joint analysis (Stages 1 + 2; β = 0.046, SE = 0.008, P = 2.46 × 10(-8), explained variance = 0.05%). Rs905938 was also associated with infant length (N = 28 228; P = 5.54 × 10(-4)) and adult height (N = 127 513; P = 1.45 × 10(-5)). DCST2 is a DC-STAMP-like protein family member and DC-STAMP is an osteoclast cell-fusion regulator. Polygenic scores based on 180 SNPs previously associated with human adult stature explained 0.13% of variance in birth length. The same SNPs explained 2.95% of the variance of infant length. Of the 180 known adult height loci, 11 were genome-wide significantly associated with infant length (SF3B4, LCORL, SPAG17, C6orf173, PTCH1, GDF5, ZNFX1, HHIP, ACAN, HLA locus and HMGA2). This study highlights that common variation in DCST2 influences variation in early growth and adult height.
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| 5. |
- Middeldorp, Christel M., et al.
(författare)
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The Early Growth Genetics (EGG) and EArly Genetics and Lifecourse Epidemiology (EAGLE) consortia : design, results and future prospects
- 2019
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Ingår i: European Journal of Epidemiology. - : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284. ; 34:3, s. 279-300
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Tidskriftsartikel (refereegranskat)abstract
- The impact of many unfavorable childhood traits or diseases, such as low birth weight and mental disorders, is not limited to childhood and adolescence, as they are also associated with poor outcomes in adulthood, such as cardiovascular disease. Insight into the genetic etiology of childhood and adolescent traits and disorders may therefore provide new perspectives, not only on how to improve wellbeing during childhood, but also how to prevent later adverse outcomes. To achieve the sample sizes required for genetic research, the Early Growth Genetics (EGG) and EArly Genetics and Lifecourse Epidemiology (EAGLE) consortia were established. The majority of the participating cohorts are longitudinal population-based samples, but other cohorts with data on early childhood phenotypes are also involved. Cohorts often have a broad focus and collect(ed) data on various somatic and psychiatric traits as well as environmental factors. Genetic variants have been successfully identified for multiple traits, for example, birth weight, atopic dermatitis, childhood BMI, allergic sensitization, and pubertal growth. Furthermore, the results have shown that genetic factors also partly underlie the association with adult traits. As sample sizes are still increasing, it is expected that future analyses will identify additional variants. This, in combination with the development of innovative statistical methods, will provide detailed insight on the mechanisms underlying the transition from childhood to adult disorders. Both consortia welcome new collaborations. Policies and contact details are available from the corresponding authors of this manuscript and/or the consortium websites.
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| 6. |
- Abbasi, Rasha, et al.
(författare)
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IceCube search for neutrinos from GRB 221009A
- 2023
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Ingår i: Proceedings of 38th International Cosmic Ray Conference (ICRC 2023). - : Sissa Medialab Srl.
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Konferensbidrag (refereegranskat)abstract
- GRB 221009A is the brightest Gamma Ray Burst (GRB) ever observed. The observed extremelyhigh flux of high and very-high-energy photons provide a unique opportunity to probe the predictedneutrino counterpart to the electromagnetic emission. We have used a variety of methods to searchfor neutrinos in coincidence with the GRB over several time windows during the precursor, promptand afterglow phases of the GRB. MeV scale neutrinos are studied using photo-multiplier ratescalers which are normally used to search for galactic core-collapse supernovae neutrinos. GeVneutrinos are searched starting with DeepCore triggers. These events don’t have directionallocalization, but instead can indicate an excess in the rate of events. 10 GeV - 1 TeV and >TeVneutrinos are searched using traditional neutrino point source methods which take into accountthe direction and time of events with DeepCore and the entire IceCube detector respectively. The>TeV results include both a fast-response analysis conducted by IceCube in real-time with timewindows of T0 − 1 to T0 + 2 hours and T0 ± 1 day around the time of GRB 221009A, as well asan offline analysis with 3 new time windows up to a time window of T0 − 1 to T0 + 14 days, thelongest time period we consider. The combination of observations by IceCube covers 9 ordersof magnitude in neutrino energy, from MeV to PeV, placing upper limits across the range forpredicted neutrino emission.
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| 7. |
- Arinell, Karin, 1982-, et al.
(författare)
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Brown Bears (Ursus arctos) Seem Resistant to Atherosclerosis Despite Highly Elevated Plasma Lipids during Hibernation and Active State
- 2012
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Ingår i: Clinical and Translational Science. - : Wiley-Blackwell. - 1752-8054 .- 1752-8062. ; 5:3, s. 269-272
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Tidskriftsartikel (refereegranskat)abstract
- Hibernation is an extreme physiological challenge for the brown bear (Ursus arctos) in which metabolism is based mainly on lipids. The study objective was to compare plasma lipids in hibernating and active free-ranging brown bears and relate them to arterial histopathology. Blood was drawn from seven immobilized free-ranging brown bears (three females, 23 years old) during hibernation in February and from the same bears while active in June and analyzed by enzymatic and automated hematology methods within 48 hours of sampling. Left anterior descending coronary arteries and aortic arches from 12 bears (six females, 1.512 years old) killed in hunting were examined by histopathology. Total plasma cholesterol decreased from hibernation to the active period (11.08 +/- 1.04 mmol/L vs. 7.89 +/- 1.96 mmol/L, P= 0.0028) as did triglyceride (3.16 +/- 0.62 mmol/L vs. 1.44 +/- 0.27 mmol/L, P= 0.00012) and LDL cholesterol (4.30 +/- 0.71 mmol/L vs. 2.02 +/- 1.03 mmol/L, P= 0.0075), whereas HDL cholesterol was unchanged. No atherosclerosis, fatty streaks, foam cell infiltration, or inflammation were seen in any arterial samples. Brown bears tolerate elevated cholesterol levels, obesity, physical inactivity, and circulatory slow flow during hibernation without signs of -atherosclerosis. This species might serve as a reverse translational model for atherosclerosis resistance.
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| 8. |
- Arinell, Karin, 1982-, et al.
(författare)
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Physical inactivity and platelet function in humans and brown bears : A comparative study
- 2018
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Ingår i: Platelets. - : Taylor & Francis. - 0953-7104 .- 1369-1635. ; 29:1, s. 87-90
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Tidskriftsartikel (refereegranskat)abstract
- Physical inactivity increases the risk of thromboembolism. However, good standardized human models on inactivity are in short supply and experimental models are few.Our objective was to investigate how standardized bed rest affects platelet aggregation in humans and to investigate if aggregation is altered in a translational model system - the hibernating brown bear (Ursus arctos). We collected blood from (1) healthy male volunteers participating in a 21-day bed rest study in head-down tilt position (-6°) 24 h a day; (2) free-ranging brown bears captured during winter hibernation and again during active state in summer. We analyzed platelet function using multiple electrode platelet aggregometry. In total, 9 healthy male volunteers (age 31.0 ± 6.4 years) and 13 brown bears (7 females and 6 males, age 2.8 ± 0.6 years) were included. In hibernating bears adenosine diphosphate, arachidonic acid, thrombin receptor activating peptide, and collagen impedance aggregometry tests were all halved compared to summer active state. In human volunteers no statistically significant changes were found between baseline and the end of bed rest. In human male volunteers 3 weeks of bed rest did not affect platelet function. In hibernating brown bears platelet aggregation was halved compared to summer and we hypothesize that this is a protective measure to avoid formation of thrombi under periods of low blood flow.
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| 9. |
- Boesen, Amanda H., et al.
(författare)
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Assessment of the LeadCare® Plus for Use on Scandinavian Brown Bears (Ursus arctos)
- 2019
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Ingår i: Frontiers in Veterinary Science. - : Frontiers Media S.A.. - 2297-1769. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Lead (Pb) exposure is associated with adverse health effects in both humans and wildlife. Blood lead levels (BLL) of sentinel wildlife species can be used to monitor environmental lead exposure and ecosystem health. BLL analyzers, such as the LeadCare (R), are validated for use in humans, assessed for use in some avian species and cattle, and are increasingly being used on wildlife to monitor lead exposure. The LeadCare (R) analyzers use a technique called anodic stripping voltammetry (ASV). Species-specific conversion equations have been proposed to approximate the levels found with gold standard measuring methods such as inductively coupled plasma mass spectrometry (ICP-MS) because the ASV method has been shown to underestimate BLL in some species. In this study we assessed the LeadCare (R) Plus (LCP) for use on Scandinavian brown bears (Ursus arctos). LCP measurements were correlated with ICP-MS with a Bland-Altman analyzed bias of 16.3-22.5%, showing a consistent overestimation of BLL analyzed with LCP. Based on this analysis we provide conversion equations for calculating ICP-MS BLL based on the LCP results in Scandinavian brown bears. Our study shows that the LeadCare (R) Plus can be used for monitoring of lead exposure by approximating gold standard levels using conversion equations. This enables comparison with other gold standard measured BLL within the observed range of this study (38.20-174.00 mu g/L). Our study also found that Scandinavian brown bears are highly exposed to environmental lead.
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| 10. |
- Evans, Alina L., et al.
(författare)
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Body mass is associated with hibernation length, body temperature, and heart rate in free-ranging brown bears
- 2023
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Ingår i: Frontiers in Zoology. - : BioMed Central (BMC). - 1742-9994. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Despite centuries of research, debate remains on the scaling of metabolic rate to mass especially for intraspecific cases. The high variation of body mass within brown bears presents a unique opportunity to study the intraspecific effects of body mass on physiological variables. The amplitude of metabolic rate reduction in hibernators is dependent on body mass of the species. Small hibernators have high metabolic rates when euthermic but experience a drastic decrease in body temperature during torpor, which is necessary to reach a very low metabolic rate. Conversely, large hibernators, such as the brown bear (Ursus arctos), show a moderate decrease in temperature during hibernation, thought to be related to the bear's large size. We studied body mass, abdominal body temperature, heart rate, and accelerometer-derived activity from 63 free-ranging brown bears (1-15 years old, 15-233 kg). We tested for relationships between body mass and body temperature, heart rate, and hibernation duration.RESULTS: The smallest individuals maintained lower body temperatures during hibernation, hibernated longer, and ended hibernation later than large bears. Unlike body temperature, winter heart rates were not associated with body mass. In summer, the opposite pattern was found, with smaller individuals having higher body temperature and daytime heart rates. Body mass was associated with body temperature in the winter hypometabolic state, even in a large hibernating mammal. Smaller bears, which are known to have higher thermal conductance, reached lower body temperatures during hibernation. During summer, smaller bears had higher body temperatures and daytime heart rates, a phenomenon not previously documented within a single mammalian species.CONCLUSION: We conclude that the smallest bears hibernated more deeply and longer than large bears, likely from a combined effect of basic thermodynamics, the higher need for energy savings, and a lower cost of warming up a smaller body.
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| 11. |
- Evans, Alina L., et al.
(författare)
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Capture, Anesthesia, and Disturbance of Free-Ranging Brown Bears (Ursus arctos) during Hibernation
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 7:7
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Tidskriftsartikel (refereegranskat)abstract
- We conducted thirteen immobilizations of previously collared hibernating two-to four-year-old brown bears (Ursus arctos) weighing 21-66 kg in central Sweden in winter 2010 and 2011 for comparative physiology research. Here we report, for the first time, an effective protocol for the capture and anesthesia of free-ranging brown bears during hibernation and an assessment of the disturbance the captures caused. Bears were darted in anthill, soil, or uprooted tree dens on eleven occasions, but two bears in rock dens fled and were darted outside the den. We used medetomidine at 0.02-0.06 mg/kg and zolazepam-tiletamine at 0.9-2.8 mg/kg for anesthesia. In addition, ketamine at 1.5 mg/kg was hand-injected intramuscularly in four bears and in six it was included in the dart at 1.1-3.0 mg/kg. Once anesthetized, bears were removed from the dens. In nine bears, arterial blood samples were analyzed immediately with a portable blood gas analyzer. We corrected hypoxemia in seven bears (PaO2 57-74 mmHg) with supplemental oxygen. We placed the bears back into the dens and antagonized the effect of medetomidine with atipamezole. Capturing bears in the den significantly increased the risk of den abandonment. One of twelve collared bears that were captured remained at the original den until spring, and eleven, left their dens (mean +/- standard deviation) 3.2 +/- 3.6 (range 0.5-10.5) days after capture. They used 1.9 +/- 0.9 intermediate resting sites, during 6.2 +/- 7.8 days before entering a new permanent den. The eleven new permanent dens were located 730 +/- 589 m from the original dens. We documented that it was feasible and safe to capture hibernating brown bears, although they behaved differently than black bears. When doing so, researchers should use 25% of the doses used for helicopter darting during the active period and should consider increased energetic costs associated with den abandonment.
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| 12. |
- Evans, Alina L., et al.
(författare)
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Physiological reactions to capture in hibernating brown bears
- 2016
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Ingår i: Conservation Physiology. - : Oxford University Press. - 2051-1434. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Human disturbance can affect animal life history and even population dynamics. However, the consequences of these disturbances are difficult to measure. This is especially true for hibernating animals, which are highly vulnerable to disturbance, because hibernation is a process of major physiological changes, involving conservation of energy during a resource-depleted time of year. During the winters of 2011-15, we captured 15 subadult brown bears (Ursus arctos) and recorded their body temperatures (n = 11) and heart rates (n = 10) before, during and after capture using biologgers. We estimated the time for body temperature and heart rate to normalize after the capture event. We then evaluated the effect of the captures on the pattern and depth of hibernation and the day of den emergence by comparing the body temperature of captured bears with that of undisturbed subadult bears (n = 11). Both body temperature and heart rate increased during capture and returned to hibernation levels after 15-20 days. We showed that bears required 2-3 weeks to return to hibernation levels after winter captures, suggesting high metabolic costs during this period. There were also indications that the winter captures resulted in delayed den emergence.
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| 13. |
- Frankowiack, Marcel, et al.
(författare)
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IgA deficiency in wolves from Canada and Scandinavia
- 2015
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Ingår i: Developmental and Comparative Immunology. - : Elsevier BV. - 0145-305X .- 1879-0089. ; 50:1, s. 26-28
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Tidskriftsartikel (refereegranskat)abstract
- Immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in both humans and selected breeds of domestic dogs. In both species, IgAD is associated with recurrent infections and immune mediated diseases. Previous results imply that IgAD is also common in the wild ancestor of domestic dogs, the gray wolf. Here, we report that serum IgA concentrations are significantly different in Scandinavian and Canadian wolves (p =3.252e-15) with an increased prevalence for IgAD in Scandinavian wolves (60%), which is as high as those found in high-risk dog breeds.
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| 14. |
- Fuchs, Boris, et al.
(författare)
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High concentrations of lead (Pb) in blood and milk of free-ranging brown bears (Ursus arctos) in Scandinavia
- 2021
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Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 287
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Tidskriftsartikel (refereegranskat)abstract
- Exposure to lead (Pb) is a global health problem for both humans and wildlife. Despite a dramatic decline in human Pb exposure following restrictions of leaded gasoline and industry and thereby an overall reduction of Pb entering the environment, Pb exposure continues to be a problem for wildlife species. Literature on scavenging terrestrial mammals, including interactions between Pb exposure and life history, is however limited.We quantified Pb concentration in 153 blood samples from 110 free-ranging Scandinavian brown bears (Ursus arctos), 1–25 years old, using inductively coupled plasma sector field mass spectrometry. We used generalized linear models to test effects of age, body mass, reproduction status and spatial distribution on the blood Pb concentrations of 56 female bears. We sampled 28 females together with 56 dependent cubs and paired their blood Pb concentrations. From 20 lactating females, we measured the Pb concentration in milk.The mean blood Pb concentration was 96.6 μg/L (range: 38.7.0–220.5 μg/L). Both the mean and range are well above established threshold concentrations for developmental neurotoxicity (12 μg/L), increased systolic blood pressure (36 μg/L) and prevalence of kidney disease in humans (15 μg/L). Lactating females had higher Pb blood concentrations compared to younger, non-lactating females. Blood Pb concentrations of dependent cubs were correlated with their mother's blood Pb concentration, which in turn was correlated with the Pb concentration in the milk.Life-long Pb exposure in Scandinavian brown bears may have adverse effects both on individual and population levels. The high blood Pb concentrations found in brown bears contrast the general reduction in environmental Pb contamination over the past decades in Scandinavia and more research is needed to identify the sources and pathways of Pb exposure in the brown bears.
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| 15. |
- Fuchs, Boris, et al.
(författare)
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Toxic elements in arctic and sub-arctic brown bears: Blood concentrations of As, Cd, Hg and Pb in relation to diet, age, and human footprint
- 2023
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Ingår i: Environmental Research. - : Academic Press Inc.. - 0013-9351 .- 1096-0953. ; 229
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Tidskriftsartikel (refereegranskat)abstract
- Contamination with arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) is a global concern impairing resilience of organisms and ecosystems. Proximity to emission sources increases exposure risk but remoteness does not alleviate it. These toxic elements are transported in atmospheric and oceanic pathways and accumulate in organisms. Mercury accumulates in higher trophic levels. Brown bears (Ursus arctos), which often live in remote areas, are long-lived omnivores, feeding on salmon (Oncorhynchus spp.) and berries (Vaccinium spp.), resources also consumed by humans.We measured blood concentrations of As, Cd, Hg and Pb in bears (n = 72) four years and older in Scandinavia and three national parks in Alaska, USA (Lake Clark, Katmai and Gates of the Arctic) using high-resolution, inductively-coupled plasma sector field mass spectrometry. Age and sex of the bears, as well as the typical population level diet was associated with blood element concentrations using generalized linear regression models.Alaskan bears consuming salmon had higher Hg blood concentrations compared to Scandinavian bears feeding on berries, ants (Formica spp.) and moose (Alces). Cadmium and Pb blood concentrations were higher in Scandinavian bears than in Alaskan bears. Bears using marine food sources, in addition to salmon in Katmai, had higher As blood concentrations than bears in Scandinavia. Blood concentrations of Cd and Pb, as well as for As in female bears increased with age. Arsenic in males and Hg concentrations decreased with age.We detected elevated levels of toxic elements in bears from landscapes that are among the most pristine on the planet. Sources are unknown but anthropogenic emissions are most likely involved. All study areas face upcoming change: Increasing tourism and mining in Alaska and more intensive forestry in Scandinavia, combined with global climate change in both regions. Baseline contaminant concentrations as presented here are important knowledge in our changing world.
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| 16. |
- Gottlieb, Lisa A, et al.
(författare)
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Translational implications of bradyarrhythmia in hibernating brown bears
- 2023
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Ingår i: Physiological Reports. - : John Wiley & Sons. - 2051-817X. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- The brown bear Ursus arctos undergoes exceptional physiological adaptions during annual hibernation that minimize energy consumption, including profound decrease in heart rate, cardiac output, and respiratory rate. These changes are completely reversible after the bears reenter into the active state in spring. In this case report, we show episodes of sinus arrest in a hibernating Scandinavian brown bear and in humans, recorded by implantable loop recorders and discuss the possible underlying mechanisms. Lessons learned from cardiac adaptations in hibernating bears might prove useful in the treatment of patients with sinus node dysfunction.
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| 17. |
- Huber, Nikolaus, et al.
(författare)
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Quantifying capture stress in free ranging European roe deer (Capreolus capreolus)
- 2017
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Ingår i: BMC Veterinary Research. - : Springer Science and Business Media LLC. - 1746-6148. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundTo understand and reduce the concomitant effects of trapping and handling procedures in wildlife species, it is essential to measure their physiological impact. Here, we examined individual variation in stress levels in non-anesthetized European roe deer (Capreolus capreolus), which were captured in box traps and physically restrained for tagging, biometrics and bio-sampling. In winter 2013, we collected venous blood samples from 28 individuals during 28 capture events and evaluated standard measurements for stress (heart rate, body temperature, neutrophil to lymphocyte ratio, lactate and total cortisol). Additionally, we assessed stress using the immunological tool, Leukocyte Coping Capacity (LCC), a real-time proxy for stress measuring oxygen radical production by leukocytes. Finally, the behavioral response to handling was recorded using a scoring system.ResultsLCC and therefore stress levels were negatively influenced by the time animals spent in the box trap with human presence at the capture site prior to handling. In contrast, none of the classical stress measures, including total cortisol, nor the behavioral assessment, were correlated with the stressor tested (time of human presence prior to handling) and thus did not provide a clear depiction regarding the extent of the animals short-term stress response.ConclusionsOverall our study verifies the LCC as a strong method to quantify short-term stress reactions in wildlife. Moreover, our results clearly show that human presence at the trapping site prior to handling should be kept to an absolute minimum in order to reduce stress levels.
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| 18. |
- Revsbech, Inge G., et al.
(författare)
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Hydrogen sulfide and nitric oxide metabolites in the blood of free-ranging brown bears and their potential roles in hibernation
- 2014
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Ingår i: Free Radical Biology & Medicine. - : Elsevier. - 0891-5849 .- 1873-4596. ; 73, s. 349-357
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Tidskriftsartikel (refereegranskat)abstract
- During winter hibernation, brown bears (Ursus arctos) lie in dens for half a year without eating while their basal metabolism is largely suppressed. To understand the underlying mechanisms of metabolic depression in hibernation, we measured type and content of blood metabolites of two ubiquitous inhibitors of mitochondrial respiration, hydrogen sulfide (H2S) and nitric oxide (NO), in winter-hibernating and summer-active free-ranging Scandinavian brown bears. We found that levels of sulfide metabolites were overall similar in summer-active and hibernating bears but their composition in the plasma differed significantly, with a decrease in bound sulfane sulfur in hibernation. High levels of unbound free sulfide correlated with high levels of cysteine (Cys) and with low levels of bound sulfane sulfur, indicating that during hibernation H2S, in addition to being formed enzymatically from the substrate Cys, may also be regenerated from its oxidation products, including thiosulfate and polysulfides. In the absence of any dietary intake, this shift in the mode of H2S synthesis would help preserve free Cys for synthesis of glutathione (GSH), a major antioxidant found at high levels in the red blood cells of hibernating bears. In contrast, circulating nitrite and erythrocytic S-nitrosation of glyceraldehyde-3-phosphate dehydrogenase, taken as markers of NO metabolism, did not change appreciably. Our findings reveal that remodeling of H2S metabolism and enhanced intracellular GSH levels are hallmarks of the aerobic metabolic suppression of hibernating bears.
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| 19. |
- Sahdo, Berolla, 1984-, et al.
(författare)
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Body temperature during hibernation is highly correlated with a decrease in circulating innate immune cells in the brown bear (Ursus arctos) : a common feature among hibernators?
- 2013
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Ingår i: International Journal of Medical Sciences. - Sydney, Australia : Ivyspring International Publisher. - 1449-1907. ; 10:5, s. 508-514
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hibernation involves periods of severely depressed metabolism (torpor) and decreases in body temperature (Tb). Small arctic mammals (<5kg), in which Tb generally drop drastically, display leukopenia during hibernation. This raised the question of whether the decreased leukocyte counts in mammalian hibernators is due to torpor per se or is secondary to low Tb. The present study examined immune cell counts in brown bears (Ursus arctos), where torpor is only associated with shallow decreases in Tb. The results were compared across hibernator species for which immune and Tb data were available.Methods and Results: The white blood cell counts were determined by flow cytometry in 13 bears captured in the field both during summer and winter over 2 years time. Tb dropped from 39.6+/-0.8 to 33.5+/-1.1 degrees C during hibernation. Blood neutrophils and monocytes were lower during hibernation than during the active period (47%, p=0.001; 43%, p=0.039, respectively), whereas no change in lymphocyte counts was detected (p=0.599). Further, combining our data and those from 10 studies on 9 hibernating species suggested that the decline in Tb explained the decrease in innate immune cells (R-2=0.83, p<0.0001).Conclusions: Bears have fewer innate immune cells in circulation during hibernation, which may represent a suppressed innate immune system. Across species comparison suggests that, both in small and large hibernators, Tb is the main driver of immune function regulation during winter dormancy. The lack of a difference in lymphocyte counts in this context requires further investigations.
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| 20. |
- Stoen, Ole-Gunnar, et al.
(författare)
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Physiological evidence for a human-induced landscape of fear in brown bears (Ursus arctos)
- 2015
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Ingår i: Physiology and Behavior. - : Elsevier. - 0031-9384 .- 1873-507X. ; 152:A, s. 244-248
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Tidskriftsartikel (refereegranskat)abstract
- Human persecution is a major cause of mortality for large carnivores. Consequently, large carnivores avoid humans, but may use human-dominated landscapes by being nocturnal and elusive. Behavioral studies indicate that certain ecological systems are "landscapes of fear", driven by antipredator behavior. Because behavior and physiology are closely interrelated, physiological assessments may provide insight into the behavioral response of large carnivores to human activity. To elucidate changes in brown bears' (Ursus arctos) behavior associated with human activity, we evaluated stress as changes in heart rate (HR) and heart rate variability (HRV) in 12 GPS-collared, free-ranging bears, 7 males and 5 females, 3-11 years old, using cardiac-monitoring devices. We applied generalized linear regression models with HR and HRV as response variables and chest activity, time of day, season, distance traveled, and distance to human settlements from GPS positions recorded every 30 mm as potential explanatory variables. Bears exhibited lower HRV, an indication of stress, when they were close to human settlements and especially during the berry season, when humans were more often in the forest, picking berries and hunting. Our findings provide evidence of a human-induced landscape of fear in this hunted population of brown bears. (C) 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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| 21. |
- Thiel, Alexandra, et al.
(författare)
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Effects of reproduction and environmental factors on body temperature and activity patterns of wolverines
- 2019
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Ingår i: Frontiers in Zoology. - : Springer Science and Business Media LLC. - 1742-9994. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mammals in the far north are exposed to extreme seasonal changes in environmental conditions, such as temperature and photoperiod, which have notable effects on animal physiology and behaviour. The wolverine (Gulo gulo) is a carnivore with a circumpolar distribution and well-adapted to extreme environmental conditions. Still, ecophysiological studies on free-ranging wolverines are lacking. In this study, we used abdominally implanted body temperature loggers in combination with GPS collars with acceleration sensors on 14 free-ranging wolverines in northern Sweden to study daily and seasonal variation in body temperature and activity patterns. We used generalized additive mixed modelling to investigate body temperature patterns over time and Lomb-Scargle periodogram analysis to analyse circadian rhythms.Results: We found that wolverines have an average core body temperature of 38.5 +/- 0.2 degrees C with a daily variation of up to 6 degrees C. Body temperature patterns varied between reproductive states. Pregnant females showed a distinct decrease in body temperature during gestation. Wolverines were active both in day and night, but displayed distinct activity peaks during crepuscular hours. However, body temperature and activity patterns changed seasonally, with a gradual change from a unimodal pattern in winter with concentrated activity during the short period of day light to a bimodal pattern in autumn with activity peaks around dusk and dawn. Wolverines were less likely to display 24-h rhythms in winter, when hours of day light are limited.Conclusions: The combination of different biologging techniques gave novel insight into the ecophysiology, activity patterns and reproductive biology of free-ranging wolverines, adding important knowledge to our understanding of animals adapted to cold environments at northern latitudes.
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| 22. |
- Thienel, Manuela, et al.
(författare)
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Immobility-associated thromboprotection is conserved across mammalian species from bear to human
- 2023
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 380:6641, s. 178-187
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Tidskriftsartikel (refereegranskat)abstract
- Venous thromboembolism (VTE) comprising deep venous thrombosis and pulmonary embolism is a major cause of morbidity and mortality. Short-term immobility-related conditions are a major risk factor for the development of VTE. Paradoxically, long-term immobilized free-ranging hibernating brown bears and paralyzed spinal cord injury (SCI) patients are protected from VTE. We aimed to identify mechanisms of immobility-associated VTE protection in a cross-species approach. Mass spectrometry-based proteomics revealed an antithrombotic signature in platelets of hibernating brown bears with heat shock protein 47 (HSP47) as the most substantially reduced protein. HSP47 down-regulation or ablation attenuated immune cell activation and neutrophil extracellular trap formation, contributing to thromboprotection in bears, SCI patients, and mice. This cross-species conserved platelet signature may give rise to antithrombotic therapeutics and prognostic markers beyond immobility-associated VTE.
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| 23. |
- Welinder, Karen Gjesing, et al.
(författare)
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Biochemical Foundations of Health and Energy Conservation in Hibernating Free-Ranging Subadult Brown Bear Ursus arctos
- 2016
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Ingår i: Journal of Biological Chemistry. - Rockville, USA : American Society for Biochemistry and Molecular Biology. - 0021-9258 .- 1083-351X. ; 291:43, s. 22509-22523
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Tidskriftsartikel (refereegranskat)abstract
- Brown bears (Ursus arctos) hibernate for 5-7 months without eating, drinking, urinating and defecating at a metabolic rate of only 25% of the summer activity rate. Nonetheless, they emerge healthy and alert in spring. We quantified the biochemical adaptations for hibernation by comparing the proteome, metabolome, and hematologic features of blood from hibernating and active free-ranging subadult brown bears with a focus on conservation of health and energy. We found that total plasma protein concentration increased during hibernation, even though the concentrations of most individual plasma proteins decreased, as did the white blood cell types. Strikingly, antimicrobial defense proteins increased in concentration. Central functions in hibernation involving the coagulation response and protease inhibition, as well as lipid transport and metabolism, were upheld by increased levels of very few key or broad-specificity proteins. The changes in coagulation factor levels matched the changes in activity measurements. A dramatic 45-fold increase in sex-hormone-binding-globulin SHBG levels during hibernation draws, for the first time, attention to its significant but unknown role in maintaining hibernation physiology. We propose that energy for the costly protein synthesis is reduced by three mechanisms, (i) dehydration, which increases protein concentration without de novo synthesis; (ii) reduced protein degradation rates due to a 6 °C reduction in body temperature, and decreased protease activity; and (iii) a marked redistribution of energy resources only increasing de novo synthesis of few key proteins. This comprehensive global data identified novel biochemical strategies for bear adaptations to the extreme condition of hibernation, and have implications for our understanding of physiology in general.
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