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Human-wildlife conflict studies of high-altitude areas are rare due to budget constraints and the challenging nature of research in these remote environments. This study investigates the prevalence and increasing trend of human-wildlife conflict (HWC) in the mountainous Gaurishankar Conservation Area (GCA) of Nepal, with a specific focus on leopard (Panthera pardus) and Himalayan black bear (Ursus thibetanus laniger). The study analyzes a decade of HWC reports and identifies goats as the livestock most targeted by leopards. The Dolakha district of GCA received the highest number of reports, highlighting the need for mitigation measures in the area. In GCA, livestock attacks accounted for 85% of compensation, with the remaining 15% for human injuries. We estimate that the number of reported wildlife attacks grew on average by 33% per year, with an additional increase of 57 reports per year following the implementation of a new compensation policy during BS 2076 (2019 AD). While bear attacks showed no significant change post-rule alteration, leopard attack reports surged from 1 to 60 annually, indicating improved compensation may have resulted in increased leopard-attack reporting rates. The findings emphasize the economic impact of HWC on local communities and suggest strategies such as increasing prey populations, promoting community education and awareness, enhancing alternative livelihood options, developing community-based insurance programs, and implementing secure enclosures (corrals) to minimize conflicts and foster harmonious coexistence. This research addresses a knowledge gap in HWC in high-altitude conservation areas like the GCA, providing valuable insights for conservation stakeholders and contributing to biodiversity conservation and the well-being of humans and wildlife.

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The polar bear (Ursus maritimus) occupies a relatively narrow ecological niche, with many traits adapted for cold temperatures, movement across snow, ice and open water, and for consuming highly lipid-dense prey species. The divergence of polar bears from brown bears (Ursus arctos) and their adaptation to their Arctic lifestyle is a well-known example of rapid evolution. Previous research investigating whole genomes uncovered twelve key genes that are highly differentiated between polar and brown bears, show signatures of selection in the polar bear lineage, and are associated with polar bear adaptation to the Arctic environment. Further research suggested fixed derived alleles in these genes arose from selection on both standing variation and de novo mutations in the evolution of polar bears. Here, we reevaluate these findings based on a larger and geographically more representative dataset of 119 polar bears and 135 brown bears, and assess the timing of derived allele fixation in polar bears by incorporating the genomes of two Late Pleistocene individuals (aged 130-100,000 years old and 100-70,000 years old). In contrast with previous results, we found no evidence of derived alleles fixed in present-day polar bears within the key genes arising from de novo mutation. Most derived alleles fixed in present-day polar bears were also fixed in the Late Pleistocene polar bears, suggesting selection occurred prior to 70,000 years ago. However, some derived alleles fixed in present-day polar bears were not fixed in the two Late Pleistocene polar bears, including at sites within APOB, LYST, and TTN. These three genes are associated with cardiovascular function, metabolism, and pigmentation, suggesting selection may have acted on different loci at different times.

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We present the pathognomonic image of the «bear paw sign¼ of xanthogranulomatous pyelonephritis, a rare form of chronic pyelonephritis typically occurring in association with obstructive uropathy (especially with staghorn calculi) and recurrent urinary tract infections.

Nous présentons l'image pathognomonique du «signe de la patte d'ours¼ de la pyélonéphrite xanthogranulomateuse, forme rare de pyélonéphrite chronique survenant classiquement sur un terrain associant une uropathie obstructive (en particulier sur lithiase coralliforme) et des infections urinaires à répétitions.

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Depression is a psychological disorder associated with prolonged stress, which involves abnormal activation of the hypothalamic-pituitary-adrenal (HPA) axis, leading to elevated levels of glucocorticoids (GC). Excessive GC can cause damage to the structure and function of the hippocampus, thereby triggering depressive symptoms. Studies suggest that the bile acid receptor farnesoid X receptor (FXR) may play a role in adrenal GC synthesis. This study aimed to explore the potential therapeutic effects of dried bear bile (DBB) on depression and its mechanism. We used the chronic unpredictable mild stress (CUMS) mouse model and FXR agonist GW4064 stimulated mice, as well as H295R human adrenal cortical carcinoma cells, employing behavioral tests, biochemical analysis, and gene expression analysis to assess the effects of DBB treatment on depressive behavior, serum corticosterone (CORT) levels, and adrenal FXR and steroid biosynthesis-related gene expression. The results showed that in both CUMS and GW4064-stimulated mice, DBB treatment significantly improved depressive-like behaviors and reversed serum CORT levels. Additionally, DBB suppressed the expression of steroidogenic regulatory genes in the adrenal glands of CUMS mice. In H295R cells, DBB treatment effectively reduced cortisol secretion induced by Forskolin, inhibited the expression of steroid biosynthesis-related genes, and suppressed cortisol production and HSD3B2 expression under conditions of FXR overexpression and FXR activation. Our findings suggest that DBB regulates adrenal FXR to modulate glucocorticoid synthesis and exerts antidepressant effects. DBB may serve as a potential therapeutic agent for depression by regulating GC levels and steroidogenesis pathway. Further research is underway to test the antidepressant effects of each DBB component to understand their specific contribution.

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Angiostrongylus vasorum, commonly known as the French heartworm, is a metastrongyloid parasitic nematode that infects wild and domestic canids. In North America, A. vasorum is endemic to the Canadian island of Newfoundland, but has been expanding to new areas including Nova Scotia, Prince Edward Island, and West Virginia (USA). Two cases of A. vasorum are reported from the state of Tennessee. The first case in a black bear (Ursus americanus) and the second case in a coyote (Canis latrans). The black bear was found dead in Sevier County in November of 2022, while the coyote was trapped and euthanized as part of a predator control program in Campbell County in January of 2023. Histology of the lungs revealed both animals had verminous pneumonia. DNA was extracted from the lungs of both, and PCR was performed using NC1 and NC2 primers. Sequencing results of the PCR products from the bear and coyote samples indicated that they were 95% and 96% similar, respectively, to European strains of A. vasorum. This report marks the first time A. vasorum has been reported in Tennessee as well as only the second and third report of autochthonous A. vasorum infection in the United States and the first report in an ursid. These two cases confirm the spread of A. vasorum further into North America. This nematode is highly pathogenic to wild and domestic canids, and thus these cases represent an emerging threat to both and underscore the need for further surveillance for the parasite.

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The Arctic is warming four times faster than the rest of the world, threatening the persistence of many Arctic species. It is uncertain if Arctic wildlife will have sufficient time to adapt to such rapidly warming environments. We used genetic forecasting to measure the risk of maladaptation to warming temperatures and sea ice loss in polar bears (Ursus maritimus) sampled across the Canadian Arctic. We found evidence for local adaptation to sea ice conditions and temperature. Forecasting of genome-environment mismatches for predicted climate scenarios suggested that polar bears in the Canadian high Arctic had the greatest risk of becoming maladapted to climate warming. While Canadian high Arctic bears may be the most likely to become maladapted, all polar bears face potentially negative outcomes to climate change. Given the importance of the sea ice habitat to polar bears, we expect that maladaptation to future warming is already widespread across Canada.

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Nurses are at the forefront of providing health education for the general public and are leaders in developing health education programs for all ages. Research has shown that the pediatric population often experience anxiety surrounding common medical procedures. However, evidence-based health education has been shown to enhance self-management, increase knowledge, and decrease anxiety in the pediatric population. One such successful evidence-based health education approach designed for the pediatric population is the Teddy Bear Clinic. The purpose of this article is to report on the efficacy of a nursing student-led Teddy Bear Clinic designed to increase the awareness of common medical equipment and procedures in the pre-school pediatric population. This quality improvement project used a program evaluation design to assess the children's knowledge of common medical procedures and equipment. Participants were a convenience sample of 16 children aged 3-5 years old, attending one daycare center in a large city in Atlantic Canada. Findings showed that after participation in the clinic, the pre-schoolers reported a high level of knowledge of common medical equipment and procedures. This project shows that a Teddy Bear Clinic run by senior nursing students can promote community partnerships and enhance health knowledge in pre-school children.

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Pregnane X receptor (PXR) is a heterologous biosensor that is involved in the metabolic pathway of environmental pollutants, regulating the transcription of genes involved in biotransformation. There are significant differences in the selectivity and specificity of organic pollutants (OPs) toward polar bear PXR (pbPXR) and human PXR (hPXR), but the detailed dynamical characteristics of their interactions are unclear. Homology Modeling, molecular docking, molecular dynamics simulation, and free energy calculation were used to analyze the recognition of pbPXR and hPXR by three OPs: BPA, chlordane and toxaphene. Comparing interaction patterns along with binding free energy of pbPXR and hPXR with these three OPs revealed that although pbPXR and hPXR interact similar with these three OPs, these OPs have different effects on the internal dynamics of pbPXR and hPXR. This results in significant alterations in the interaction of key residues near Leu209, Met243, Phe288, Met323, and His407 with OPs, thereby influencing their binding energy. Non-polar interactions, especially van der Waals interactions, were found to be the dominating factors in interacting of these OPs with PXRs. The region surrounding these key residues facilitates hydrophobic contacts with PXR, which are crucial for the selective activation of PXRs in different species by these three OPs. These findings are of significant guidance in understanding the impacts of environmental endocrine disruptors on different organisms.

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Captive and free-living wildlife serve as significant hosts for Giardia duodenalis. Asiatic black bears, valued for their economic and medicinal importance, are extensively farmed in China and also prevalent in zoos. However, studies on G. duodenalis in these animals in China are limited. Here, 218 feces samples of Asiatic black bears were collected: 36 from a zoo in Heilongjiang Province, and 182 from a farm in Fujian Province. Nested PCR of the SSU rRNA gene, followed by sequencing, was employed to determine the frequency and assemblage distribution of G. duodenalis. Positive samples underwent further analysis through multilocus genotyping (MLG) by amplifying the genes for glutamate dehydrogenase (gdh), ß-giardin (bg), and triosephosphate isomerase (tpi). Of the 218 samples, G. duodenalis was detected in 22 cases at the SSU rRNA gene locus, including three from Heilongjiang and 19 from Fujian. Three assemblages were identified: A (n = 1), B (n = 16), and E (n = 2) in Fujian; and B (n = 3) in Heilongjiang. Out of the 22 positive samples, 20, 19, and 9 were effectively amplified and sequenced across the tpi, gdh, and bg loci, respectively. Seven samples were genotyped successfully at all three loci, identifying MLG-B1 (n = 1), MLG-B2 (n = 1), and MLG-B3 (n = 1), MLG-B4 (n = 1), MLG-B5 (n = 2), and MLG-B6 (n = 1) as the six assemblage B MLGs. This study marks the first documentation of G. duodenalis in Asiatic black bears in captivity in Fujian and Heilongjiang. The identification of zoonotic assemblages A and B, along with E, underscores potential public health concerns.

Title: Prévalence et assemblages de Giardia duodenalis chez les ours noirs d'Asie (Ursus thibetanus) d'élevage et de zoos dans les provinces chinoises du Heilongjiang et du Fujian. Abstract: Les faunes captive et libre incluent des hôtes importants pour Giardia duodenalis. Les ours noirs d'Asie, appréciés pour leur importance économique et médicinale, sont couramment élevés en Chine et répandus dans les zoos. Cependant, les études sur G. duodenalis chez ces animaux en Chine sont limitées. Ici, 218 échantillons d'excréments d'ours noirs d'Asie ont été collectés, 36 dans un zoo de la province du Heilongjiang et 182 dans une ferme de la province du Fujian. La PCR imbriquée de l'ARNr SSU, suivie d'un séquençage, a été utilisée pour déterminer la fréquence et la distribution des assemblages de G. duodenalis. Les échantillons positifs ont subi une analyse plus approfondie par génotypage multilocus (MLG) en amplifiant les gènes de la glutamate déshydrogénase (gdh), de la ß-giardine (bg) et de la triosephosphate isomérase (tpi). Sur les 218 échantillons, G. duodenalis a été détecté dans 22 cas par le locus du gène de l'ARNr SSU, dont trois du Heilongjiang et 19 du Fujian. Trois assemblages ont été identifiés : A (n = 1), B (n = 16) et E (n = 2) dans le Fujian, et B (n = 3) dans le Heilongjiang. Sur les 22 échantillons positifs, 20, 19 et 9 ont été efficacement amplifiés et séquencés respectivement pour les loci tpi, gdh et bg. Sept échantillons ont été génotypés avec succès sur les trois loci, identifiant MLG-B1 (n = 1), MLG-B2 (n = 1) et MLG-B3 (n = 1), MLG-B4 (n = 1), MLG- B5 (n = 2) et MLG-B6 (n = 1) comme les six assemblages MLG B. Cette étude marque la première investigation de G. duodenalis chez les ours noirs d'Asie en captivité au Fujian et au Heilongjiang. L'identification des assemblages zoonotiques A et B, ainsi que E, souligne des problèmes potentiels de santé publique.

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Severe musculoskeletal disease characterized by marked joint laxity was the cause of euthanasia in two wild juvenile American black bears (Ursus americanus) admitted to a rehabilitation facility in eastern Tennessee in 2023. Previously, almost all reported musculoskeletal diseases in this population were of traumatic etiology, even in malnourished yearlings. Case 1 was an orphaned 11-month-old male cub exhibiting disproportionate dwarfism, progressive immobility, and joint laxity. Necropsy findings suggested either chondrodysplasia or rickets, and imaging findings supported a skeletal dysplasia. Case 2 was a 14-month-old emaciated male yearling exhibiting joint laxity and immobility. Necropsy findings showed osteoporosis and serous atrophy of fat, and imaging findings were inconsistent with a skeletal dysplasia. Both cases were clinically inconsistent with rickets based on normal calcium, phosphorous, and parathyroid hormone concentrations; however, Case 1 had hypovitaminosis D (9 nmol/L) compared to healthy juvenile black bears. We hypothesize that Case 1 had a genetic chondrodysplasia while the osteoporosis of Case 2 was due to chronic malnutrition. The goal of this case report is to inform wildlife agencies and facilities to monitor for similar, non-trauma-related debilitating musculoskeletal disease in free-ranging bears and evaluate cases that allow us to further understand the disease processes involved.

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The study of animal movement provides insights into underlying ecological processes and informs analyses of behaviour and resource use, which have implications for species management and conservation. The tools used to study animal movement have evolved over the past decades, allowing for data collection from a variety of species, including those living in remote environments. Satellite-linked radio and GPS collars have been used to study polar bear (Ursus maritimus) ecology and movements throughout the circumpolar Arctic for over 50 years. However, due to morphology and growth constraints, only adult female polar bears can be reliably collared. Collars have proven to be safe, but there has been opposition to their use, resulting in a deficiency in data across much of the species' range. To bolster knowledge of movement characteristics and behaviours for polar bears other than adult females, while also providing an alternative to collars, we tested the use of fur- and ear-mounted telemetry tags that can be affixed to polar bears of any sex and age. We tested three fur tag designs (SeaTrkr, tribrush and pentagon tags), which we affixed to 15 adult and 1 subadult male polar bears along the coast of Hudson Bay during August-September 2021-2022. Fur tags were compared with ear tags deployed on 42 subadult and adult male polar bears captured on the coast or the sea ice between 2016 and 2022. We used data from the tags to quantify the amount of time subadult and adult males spent resting versus traveling while on land. Our results show the three fur tag designs remained functional for shorter mean durations (SeaTrkr = 58 days; tribrush = 47 days; pentagon = 22 days) than ear tags (121 days), but positional error estimates were comparable among the Argos-equipped tags. The GPS/Iridium-equipped SeaTrkr fur tags provided higher resolution and more frequent location data. Combined, the tags provided sufficient data to model different behavioural states. Furthermore, as hypothesized, subadult and adult male polar bears spent the majority of their time resting while on land, increasing time spent traveling as temperatures cooled. Fur tags show promise as a short-term means of collecting movement data from free-ranging polar bears. Supplementary Information: The online version contains supplementary material available at 10.1186/s40317-024-00373-2.

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Sloth bears are non-carnivorous yet they attack more people than any other bear. They often stand up and charge explosively if a person mistakenly gets too close. Here, we argue that their aggression toward humans is an extension of their behavior toward tigers, which are their only natural predator. Interactions between sloth bears and tigers have not previously been studied because scientists have rarely observed such events. We collected and examined 43 videos or photo documentations of sloth bear-tiger interactions posted on the internet or social media from 2011 to 2023, mainly by tourists visiting tiger parks in India. We observed that sloth bears were most likely to stand up and charge if they first became aware of the tiger at close range (<3 m away). This aggressive-defensive strategy, intended to dissuade the tiger from attacking, appeared to be successful, in that 86% of interactions ended with no contact, whereas four (9%) culminated in the bear's death. We propose that a myrmecophagous diet led to this species' aggressive behavior: (1) their long, blunt front claws, well adapted for digging termites and ants, hamper their ability to climb trees for escape, and (2) they walk with their head down focused on scents underground, and make considerable noise digging and blowing soil, enabling tigers to approach quite closely without being detected. Sloth bears have coexisted with tigers or other (now extinct) large felid predators for their entire evolutionary history. Whereas their aggressive behavior has served them well for millions of years, more recently, people's fear of and retaliation against sloth bears represents a major threat to their survival. Understanding how sloth bears react to tigers provides guidance for reducing attacks on humans, thereby contributing to sloth bear conservation. Our investigation was made possible by passive citizen scientists, who unknowingly collected valuable data.

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Reports on neoplasms in bears are scarce, especially concerning ovarian tumors. A large primary ovarian neoplasm with multiple metastasis was found during the necropsy of a 14-year-old free-ranging Eurasian brown bear (Ursus arctos) from Northwestern Spain. Histopathology and immunohistochemistry allowed for the diagnosis of a sex cord stromal tumor. This is a complex group of neoplasms which differ in the predominant cell morphology and immunohistochemical features. The microscopic examination revealed two types of cells, one with eosinophilic cytoplasm, intermingled with larger vacuolated cells rich in lipids. The evaluation of the immunoreactivity to different markers, frequently used in the characterization of gonadal tumors (INHA, inhibin-alpha; PLAP, placental alkaline phosphatase; Ki-67; α-SMA, actin alpha-smooth muscle) and inflammation patterns (IBA1, ionized calcium-binding adapter molecule for macrophages; CD3 for T lymphocytes; CD20 for B lymphocytes), displayed significant INHA positive immunostaining of neoplastic cells, as well as inflammatory cell infiltration, mainly composed of macrophages and B lymphocytes. These findings were consistent with a malignant ovarian steroid cell tumor, not otherwise specified. The present study characterizes an unusual type of neoplasm, and also represents the first report of an ovarian sex cord stromal tumor in Ursidae.

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Arctomecon californica, the Las Vegas bear poppy, is a rare plant found only in the eastern Mojave Desert of North America. Because of recent declines in the populations of this endemic plant, conservationists are currently seeking protection for A. californica under the US Endangered Species Act. In this study, we investigated the natural history of A. californica and documented insect visitors potentially pollinating A. californica in Clark County, Nevada. We find that the populations of A. californica fluctuate from year to year, with many populations declining by over 90% from 2021 to 2022. The pollinator communities of A. californica also vary from year to year. In some years, specialist bees in the genus Perdita make up the majority of pollinators, while in other years, generalist bees like Apis mellifera and Hylaeus dominate. Furthermore, we confirm what previous work has suggested, that A. californica requires pollinators to set seed, yet not all insect visitors are good pollinators. This work provides useful natural history information about the Las Vegas bear poppy, which will be informative to conservationists designing strategies to protect this imperiled species.

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Francisella tularensis is an intracellular gram-negative bacterium known as the causative agent of tularemia, which can be transmitted to humans by direct contact with wild animals or by tick bites. Although F. tularensis is highly pathogenic, its recent prevalence in Japan is underreported due to the small number of reported cases. To clarify the current situation of F. tularensis in wild animals, we conducted surveillance on various species of wild animals in Yamaguchi prefecture. In this study, we screened 809 samples collected from 90 Japanese black bears, 105 Japanese monkeys, 168 sika deer, 205 wild boars, and 84 bats. For seroprevalence analysis, we tested 177 serum samples from 75 black bears and 102 monkeys using the microagglutination test. The results showed that serums from five black bears exhibited slight agglutination. Western blot was performed as a confirmatory test on these five samples, but no positive signals were detected. Additionally, molecular surveillance was conducted using DNA extracted from 464 whole blood and 168 tissues, targeting the gene encoding 23 KDa hypothetical protein by real-time PCR and outer membrane protein A gene by conventional PCR. No positive samples of F. tularensis were detected by either real-time or conventional PCR. Although we did not detect any F. tularensis-positive samples through serological and molecular analyses, continuous surveillance studies are necessary since sporadic human cases have been reported in Japan.

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Foot-and-mouth disease (FMD) outbreaks affecting Asiatic black bears (Ursus thibetanus) and a Malayan sun bear (Helarctos malayanus) were previously reported in 2011 in two housing facilities at a Vietnamese bear rescue centre. In this study, demographic data of all animals housed in the centre at the time of the outbreaks (n = 79) were collected. Blood samples drawn from 23 bears at different timepoints were tested for FMDV-specific antibodies targeting using a non-structural protein (NSP) ELISA and by virus neutralisation test (VNT). The relationship between seroconversion and clinical signs was explored and epidemic curves and transmission diagrams were generated for each outbreak, where FMD cases were defined as animals showing FMD clinical signs. Outbreak-specific attack rates were 18.75 and 77.77%, with corresponding basic reproduction numbers of 1.11 and 1.92, for the first and second outbreaks, respectively. Analyses of risk factors showed that after adjusting for sex there was strong evidence for a decrease in odds of showing clinical signs per year of age. All samples collected from bears before the outbreak tested negative to NSP and VNT. All cases tested positive to VNT following onset of clinical signs and remained positive during the rest of the follow up period, while only 6 out of 17 cases tested positive to NSP after developing clinical signs. Six animals without clinical signs were tested post outbreaks; five seroconverted using VNT and three animals were seropositive using NSP ELISA. This study provides initial epidemiological parameters of FMD in captive bears, showing that FMDV is easily spread between bears in close proximity and can cause clinical and subclinical disease, both of which appear to induce rapid and long-lasting immunity.

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We report a natural infection with a Eurasian highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus in a free-ranging juvenile polar bear (Ursus maritimus) found dead in North Slope Borough, Alaska, USA. Continued community and hunter-based participation in wildlife health surveillance is key to detecting emerging pathogens in the Arctic.

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AIMS: We investigated the presence of SARS-CoV-2 in free-ranging wildlife populations in Northeastern Minnesota on the Grand Portage Indian Reservation and Isle Royale National Park. METHODS AND RESULTS: One hundred twenty nasal samples were collected from white-tailed deer, moose, grey wolves and black bears monitored for conservation efforts during 2022-2023. Samples were tested for viral RNA by RT-qPCR using the CDC N1/N2 primer set. Our data indicate that no wildlife samples were positive for SARS-CoV-2 RNA. CONCLUSIONS: Continued surveillance is therefore crucial to better understand the changing landscape of zoonotic SARS-CoV-2 in the Upper Midwest.

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The baubellum (os clitoridis) is a bone found in the clitoris of many female eutherian mammals and is homologous to the baculum in males. In contrast to the baculum, the baubellum has received very little attention regarding its morphological or interspecific diversity, or on hypotheses for its function. The presence of the baubellum in bears (Ursidae) has only been established and mentioned in the literature for the Ursus genus, and not for the other genera of bears. Moreover, no scaled photographs are available for baubella of this clade, and the sizes reported vary between sources. We hereby present and describe the baubellum of a spectacled bear (Tremarctos ornatus), providing a detailed account of baubella in a basal ursid species. The baubellum of Tremarctos is slightly bowed dorsally, with two small prominences at the distal apex. The length of the Tremarctos baubellum in this study is comparable to that of Ursus americanus (American black bear). We infer the specific shape, with longitudinal ridges, of the baubellum in Tremarctos could indicate a discrete function during copulation or sexual arousal. However, future studies, especially regarding the associated soft tissues, will be required to confirm whether this is indeed the case. Our study expands the understanding of baubella within Ursidae, providing new data (including a three-dimensional model) that can be used to further explore the morphological diversity and function of this enigmatic extra-skeletal bone.

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Epigenetic regulation plays an important role in the evolution of species adaptations, yet little information is available on the epigenetic mechanisms underlying the adaptive evolution of bamboo-eating in both giant pandas (Ailuropoda melanoleuca) and red pandas (Ailurus fulgens). To investigate the potential contribution of epigenetic to the adaptive evolution of bamboo-eating in giant and red pandas, we performed hepatic comparative transcriptome and methylome analyses between bamboo-eating pandas and carnivorous polar bears (Ursus maritimus). We found that genes involved in carbohydrate, lipid, amino acid, and protein metabolism showed significant differences in methylation and expression levels between the two panda species and polar bears. Clustering analysis of gene expression revealed that giant pandas did not form a sister group with the more closely related polar bears, suggesting that the expression pattern of genes in livers of giant pandas and red pandas have evolved convergently driven by their similar diets. Compared to polar bears, some key genes involved in carbohydrate metabolism and biological oxidation and cholesterol synthesis showed hypomethylation and higher expression in giant and red pandas, while genes involved in fat digestion and absorption, fatty acid metabolism, lysine degradation, resistance to lipid peroxidation and detoxification showed hypermethylation and low expression. Our study elucidates the special nutrient utilization mechanism of giant pandas and red pandas and provides some insights into the molecular mechanism of their adaptive evolution of bamboo feeding. This has important implications for the breeding and conservation of giant pandas and red pandas.