Effectiveness of different types of hair traps for brown bear research and monitoring.
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ABSTRACT:
SUBMITTER: Berezowska-Cnota T
PROVIDER: S-EPMC5657975 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Although combining genetic and endocrine data from non-invasively collected hair samples has potential to improve the conservation of threatened mammals, few studies have evaluated this opportunity. In this study, we determined if steroid hormone (testosterone, progesterone, estradiol and cortisol) concentration profiles in 169 hair samples collected from free-ranging brown bears (Ursus arctos) could be used to accurately discriminate between immature and adult bears within each sex. Because hair samples were acquired opportunistically, we also needed to establish if interactions between hormones and several non-hormone factors (ordinal day, year, contact method, study area) were associated with age class. For each sex, we first compared a suite of candidate models by Akaike Information Criteria model selection, using different adult-age thresholds (3, 4 and 5 years), to determine the most supported adult age. Because hair hormone levels better reflect the endocrine state at an earlier time, possibly during the previous year, then at the time of sampling, we re-analysed the data, excluding the records for bears at the adult-age threshold, to establish if classification accuracy improved. For both sexes, candidate models were most supported based on a 3-year-old adult-age threshold. Classification accuracy did not improve with the 3-year-old bear data excluded. Male age class was predicted with a high degree of accuracy (88.4%) based on the concomitant concentrations of all four hormones. Female age class was predicted with less accuracy (77.1%) based only on testosterone and cortisol. Accuracy was reduced for females, primarily because we had poor success in correctly classifying immature bears (60%) whereas classification success for adult females was similar to that for males (84.5%). Given the small and unbalanced sample used in this study, our findings should be viewed as preliminary, but they should also provide a basis for more comprehensive future studies.
| S-EPMC5788069 | biostudies-literature
Project description:The tight regulation of Ca(2+) is essential for inner ear function, and yet the role of Ca(2+) binding proteins (CaBPs) remains elusive. By using immunofluorescence and reverse transcriptase-polymerase chain reaction (RT-PCR), we investigated the expression of oncomodulin (Ocm), a member of the parvalbumin family, relative to other EF-hand CaBPs in cochlear and vestibular organs in the mouse. In the mouse cochlea, Ocm is found only in outer hair cells and is localized preferentially to the basolateral outer hair cell membrane and to the base of the hair bundle. Developmentally, Ocm immunoreactivity begins as early as postnatal day (P) 2 and shows preferential localization to the basolateral membrane and hair bundle after P8. Unlike the cochlea, Ocm expression is substantially reduced in vestibular tissues at older adult ages. In vestibular organs, Ocm is found in type I striolar or central hair cells, and has a more diffuse subcellular localization throughout the hair cell body. Additionally, Ocm immunoreactivity in vestibular hair cells is present as early as E18 and is not obviously affected by mutations that cause a disruption of hair bundle polarity. We also find Ocm expression in striolar hair cells across mammalian species. These data suggest that Ocm may have distinct functional roles in cochlear and vestibular hair cells.
| S-EPMC2909616 | biostudies-literature
Project description:The increasing trend of large carnivore attacks on humans not only raises human safety concerns but may also undermine large carnivore conservation efforts. Although rare, attacks by brown bears Ursus arctos are also on the rise and, although several studies have addressed this issue at local scales, information is lacking on a worldwide scale. Here, we investigated brown bear attacks (n = 664) on humans between 2000 and 2015 across most of the range inhabited by the species: North America (n = 183), Europe (n = 291), and East (n = 190). When the attacks occurred, half of the people were engaged in leisure activities and the main scenario was an encounter with a female with cubs. Attacks have increased significantly over time and were more frequent at high bear and low human population densities. There was no significant difference in the number of attacks between continents or between countries with different hunting practices. Understanding global patterns of bear attacks can help reduce dangerous encounters and, consequently, is crucial for informing wildlife managers and the public about appropriate measures to reduce this kind of conflicts in bear country.
| S-EPMC6562097 | biostudies-literature
Project description:Study Design Systematic review. Study Rationale Numerous cervical laminoplasty techniques have been described but there are few studies that have compared these to determine the superiority of one over another. Clinical Questions The clinical questions include key question (KQ)1: In adults with cervical myelopathy from ossification of the posterior longitudinal ligament (OPLL) or spondylosis, what is the comparative effectiveness of open door cervical laminoplasty versus French door cervical laminoplasty? KQ2: In adults with cervical myelopathy from OPLL or spondylosis, are postoperative complications, including pain and infection, different for the use of miniplates versus the use of no plates following laminoplasty? KQ3: Do these results vary based on early active postoperative cervical motion? Materials and Methods A systematic review of the English-language literature was undertaken for articles published between 1970 and March 11, 2013. Electronic databases and reference lists of key articles were searched to identify studies evaluating (1) open door cervical laminoplasty and French door cervical laminoplasty and (2) the use of miniplates or no plates in cervical laminoplasty for the treatment of cervical spondylotic myelopathy or OPLL in adults. Studies involving traumatic onset, cervical fracture, infection, deformity, or neoplasms were excluded, as were noncomparative studies. Two independent reviewers (A.L.R., J.R.D.) assessed the level of evidence quality using the Grades of Recommendations Assessment, Development and Evaluation system, and disagreements were resolved by consensus. Results We identified three studies (one of class of evidence [CoE] II and two of CoE III) meeting our inclusion criteria comparing open door cervical laminoplasty with French door laminoplasty and two studies (one CoE II and one CoE III) comparing the use of miniplates with no plates. Data from one randomized controlled trial (RCT) and two retrospective cohort studies suggest no difference between treatment groups regarding improvement in myelopathy. One RCT reported significant improvement in axial pain and significantly higher short-form 36 scores in the French door laminoplasty treatment group. Overall, complications appear to be higher in the open door group than the French door group, although complete reporting of complications was poor in all studies. Overall, data from one RCT and one retrospective cohort study suggest that the incidence of complications (including reoperation, radiculopathy, and infection) is higher in the no plate treatment group compared with the miniplate group. One RCT reported greater pain as measured by the visual analog scale score in the no plate treatment group. There was no evidence available to assess the effect of early cervical motion for open door cervical laminoplasty compared with French door laminoplasty. Both studies comparing the use of miniplates and no plates reported early postoperative motion. Evidence from one RCT suggests that earlier postoperative cervical motion might reduce pain. Conclusion Data from three comparative studies are not sufficient to support the superiority of open door cervical laminoplasty or French door cervical laminoplasty. Data from two comparative studies are not sufficient to support the superiority of the use of miniplates or no plates following cervical laminoplasty. The overall strength of evidence to support any conclusions is low or insufficient. Thus, the debate continues while opportunity exists for the spine surgery community to resolve these issues with appropriately designed clinical studies.
| S-EPMC3836957 | biostudies-literature
Project description:Muscle atrophy is one of the main deleterious consequences of ageing and physical inactivity. Although basic knowledge regarding the underlying mechanisms of muscle atrophy is continuously growing, there are still no efficient therapeutic strategies for its prevention and treatment. Hibernating bears exhibit a strong and unique ability to preserve muscle mass in conditions where muscle atrophy is observed in humans. However, underlying mechanisms have not been understood yet. To fill this gap, the aim of this study was to characterize changes in the bear muscle proteome during hibernation versus the active period. Muscle biopsies were obtained from Ursus arctos bears.
2019-05-14 | PXD004908 | Pride
Project description:Trends in population abundance can be challenging to quantify during range expansion and contraction, when there is spatial variation in trend, or the conservation area is large. We used genetic detection data from natural bear rubbing sites and spatial capture-recapture (SCR) modeling to estimate local density and population growth rates in a grizzly bear population in northwestern Montana, USA. We visited bear rubs to collect hair in 2004, 2009-2012 (3,579-4,802 rubs) and detected 249-355 individual bears each year. We estimated the finite annual population rate of change 2004-2012 was 1.043 (95% CI?=?1.017-1.069). Population density shifted from being concentrated in the north in 2004 to a more even distribution across the ecosystem by 2012. Our genetic detection sampling approach coupled with SCR modeling allowed us to estimate spatially variable growth rates of an expanding grizzly bear population and provided insight into how those patterns developed. The ability of SCR to utilize unstructured data and produce spatially explicit maps that indicate where population change is occurring promises to facilitate the monitoring of difficult-to-study species across large spatial areas.
| S-EPMC6856102 | biostudies-literature
Project description:BACKGROUND:Information on hemostasis and platelet function in brown bear (Ursus arctos) is of importance for understanding the physiological, protective changes during hibernation. OBJECTIVE:The study objective was to document platelet activity values in brown bears shortly after leaving the den and compare them to platelet function in healthy humans. METHODS:Blood was drawn from immobilized wild brown bears 7-10 days after leaving the den in mid April. Blood samples from healthy human adults before and after clopidogrel and acetylsalicylic acid administration served as control. We analyzed blood samples by standard blood testing and platelet aggregation was quantified after stimulation with various agonists using multiple electrode aggregometry within 3 hours of sampling. RESULTS:Blood samples were collected from 6 bears (3 females) between 1 and 16 years old and from 10 healthy humans. Results of adenosine diphosphate, aspirin, and thrombin receptor activating peptide tests in bears were all half or less of those in humans. Platelet and white blood cell counts did not differ between species but brown bears had more and smaller red blood cells compared with humans. CONCLUSION:Using three different tests, we conclude that platelet function is lower in brown bears compared to humans. Our findings represent the first descriptive study on platelet function in brown bears and may contribute to explain how bears can endure denning without obvious thrombus building. However, the possibility that our findings reflect test-dependent and not true biological variations in platelet reactivity needs further studies.
| S-EPMC2893130 | biostudies-literature
Project description:Large carnivore attacks on humans are a serious form of human-wildlife interaction which has increased globally in recent decades. When attacks occur, both humans and large carnivores suffer, highlighting the need to characterize these conflicts toward mitigation of attacks. We investigated brown bear (Ursus arctos) and Persian leopard (Panthera pardus) attacks on humans across Iran using reports provided by the Government of Iran during 2012-2020. We characterized temporal and spatial patterns of attacks, as well as species-specific attributes. We identified 83 attacks resulting in 77 human injuries and 6 fatalities. Bears were responsible for more attacks (63%) than leopards (37%). Attacks occurred more frequently during defensive reactions by bears and leopards on adult male people while livestock herding during the day in spring and summer. Bears reportedly attacked people more often in western provinces of Iran, while leopards attacked more frequently in northern provinces. We recommend that the Iran Department of the Environment consider implementing a national reporting system to document bear and leopard attacks on people. We further suggest development of national bear and leopard management plans that emphasize mitigating human risk to improve human attitudes toward these carnivore species to facilitate their conservation.
| S-EPMC8297784 | biostudies-literature
Project description:We combine a recently developed framework for describing dietary generalism with compositional data analysis to examine patterns of omnivory in a large widely distributed mammal. Using the brown bear (Ursus arctos) as a model species, we collected and analyzed data from the literature to estimate the proportions of macronutrients (protein, carbohydrate, and lipid) in the diets of bear populations. Across their range, bears consumed a diversity of foods that resulted in annual population diets that varied in macronutrient proportions, suggesting a wide fundamental macronutrient niche. The variance matrix of pairwise macronutrient log-ratios indicated that the most variable macronutrient among diets was carbohydrate, while protein and lipid were more proportional or codependent (i.e., relatively more constant log-ratios). Populations that consumed anthropogenic foods, such agricultural crops and supplementary feed (e.g., corn), had a higher geometric mean proportion of carbohydrate, and lower proportion of protein, in annual diets. Seasonally, mean diets were lower in protein and higher in carbohydrate, during autumn compared to spring. Populations with anthropogenic subsidies, however, had higher mean proportions of carbohydrate and lower protein, across seasons compared to populations with natural diets. Proportions of macronutrients similar to those selected in experiments by captive brown bears, and which optimized primarily fat mass gain, were observed among hyperphagic prehibernation autumn diets. However, the majority of these were from populations consuming anthropogenic foods, while diets of natural populations were more variable and typically higher in protein. Some anthropogenic diets were close to the proportions selected by captive bears during summer. Our results suggest that omnivory in brown bears is a functional adaptation enabling them to occupy a diverse range of habitats and tolerate variation in the nutritional composition and availability of food resources. Furthermore, we show that populations consuming human-sourced foods have different dietary macronutrient proportions relative to populations with natural diets.
| S-EPMC5817158 | biostudies-literature
Project description:Additional weight due to contamination (water and/or contaminating particles) can potentially have a detrimental effect on the flight capabilities of large winged insects such as butterflies and dragonflies. Insects where the wing surface area-body mass ratio is very high will be even more susceptible to these effects. Water droplets tend to move spontaneously off the wing surface of these insects. In the case of the brown lacewing, the drops effectively encounter a dual bed of hair springs with a topographical structure which aids in the hairs resisting penetration into water bodies. In this article, we demonstrate experimentally how this protective defense system employed by the brown lacewing (Micromus tasmaniae) aids in resisting contamination from water and how the micro- and nanostructures found on these hairs are responsible for quickly shedding water from the wing which demonstrates an active liquid-repelling surface.
| S-EPMC3037568 | biostudies-literature