Search Results (376)

The study develops and implements a methodology for prioritizing power units (PUs) of captive power plants (CPPs) to support the development of maintenance and repair (M&R) programs considering their actual technical condition (TC) and reliability indicators. The proposed approach is based on the joint assessment of the technical condition index (TCI), the consumed technical resource (CTR), and the risk level (RL) of the PUs. To describe the statistical patterns of failures, a two-parameter Weibull distribution is applied, while the temporal change in the TCI is approximated by a linear relationship that accounts for differences between actual and nominal operating conditions. The CTR is defined as an integral characteristic reflecting the deviation between the actual and nominal TCI degradation functions. The RL is evaluated as a function of the probability of failure and the consequences of PU failure. Based on these individual indicators, an integrated priority index is formed to provide an unambiguous ranking of PUs. The methodology was implemented using actual operational data from a fleet of PUs of an energy company. The results demonstrate that using the TCI alone does not fully reflect the actual TC of the PUs, whereas the combined consideration of TC, CTR, and RL enables a more justified formation of M&R programs. The practical significance of the study lies in the possibility of applying the developed methodology for reliability management of PUs at CPPs under resource constraints. Full article

Background/Objectives: Pygmy rabbits (Brachylagus idahoensis) are closely associated with sagebrush steppe habitat across the western United States, and loss and fragmentation of this habitat has contributed to the near extirpation of the Columbia Basin population in Washington state (CB). The CB pygmy rabbit was listed under the Endangered Species Act in 2003, and recovery efforts have included captive breeding, reintroduction, and genetic rescue with the translocation of rabbits from populations across the species range. Methods: We used restriction site-associated DNA sequencing (RADseq) on samples from across the species range, including CB pygmy rabbits captured prior to genetic rescue and admixture. We determined population genetic structure across the pygmy rabbit range, tested for genomic signatures of adaptive divergence among populations, assessed the genetic distinctiveness of the ancestral CB population, and identified loci useful for monitoring ancestry in the current admixed CB population. Results: Our dataset included 9794 single-nucleotide polymorphisms (SNPs) across 123 individuals. We identified four distinct genetic groups, including the central portion of the species range and three peripheral populations: CB, northern Utah/Wyoming, and southern Utah. The ancestral CB population showed the highest degree of genetic distinctiveness using multiple clustering, ordination, and genetic differentiation analyses. We identified evidence for putatively adaptive variation among populations, but no significant gene ontology associated with local adaptation. Conclusions: Our results highlight the long-term isolation of the ancestral CB population as well as historical isolation of other peripheral populations. Our results also provide SNP loci for monitoring the consequences of genetic rescue efforts in the current admixed CB population. Full article

The Iberian lynx (Lynx pardinus), once considered the most endangered felid, has shown demographic recovery thanks to intensive conservation measures. Over the past two decades, large physiological datasets have supported both clinical management and research, yet thyroid function has remained comparatively underexplored. This study provides the first reference intervals (RI) for total thyroxine (TT4) and thyroid-stimulating hormone (TSH) in captive and wild lynxes, and assesses the effects of age, sex, and environment. Serum samples from 71 individuals (32 captive, 39 wild; 32 females, 39 males) were analysed, including 32 young adults, 14 adults, and 25 geriatric animals. TT4 was measured by enzyme immunoassay, and TSH using chemiluminescence. TT4 RI was 0.80–2.00 µg/dl (captive) and 0.70–2.20 µg/dl (wild) (p = 0.065). TSH RI was 0.00–1.10 ng/ml (captive) and 0.00–0.10 ng/ml (wild), showing a significant difference (p < 0.001). Captive males had higher TT4 than females (p = 0.018), while no sex difference appeared in wild lynxes (p = 0.408). Age had no significant effect on TT4 (p = 0.462) or TSH (p = 0.739). Findings confirmed that environment and sex (captivity) influenced thyroid parameters, while age did not. These values are crucial for health monitoring and endocrine assessment in this endangered species. Full article

Gut microbiota are integral to host health and ecological adaptation, yet their interactions with environmental microbial communities remain understudied in migratory waterbirds. Using high-throughput 16S rRNA gene sequencing, we compared gut microbiota of captive and wild Siberian cranes and their associations with soil microbiota in the Poyang Lake wetlands. Alpha diversity was significantly higher in soil than in gut microbiota, with captive cranes exhibiting greater microbial richness and evenness than wild individuals. Beta diversity analysis revealed distinct gut and soil microbiota, with partial overlap between captive and wild crane gut microbiota. Firmicutes dominated gut communities, with Ligilactobacillus and Romboutsia enriched in captive cranes, whereas Acidobacteria were predominant in soil. Escherichia-Shigella was more abundant in wild cranes and soil. Linear discriminant analysis (LDA) effect size (LEfSe) analysis identified 34 differentially enriched taxa, and microbial network analysis indicated stronger gut–soil microbial associations than those between captive and wild hosts. Network analysis further revealed distinct co-occurrence patterns between captive and wild groups, suggesting potential shifts in microbial interaction structures under different living conditions. These findings provide preliminary insights that may inform future conservation strategies for Siberian cranes. Full article

Forest musk deer (Moschus berezovskii) are endangered ungulates, and captive breeding has been effective for its ex situ conservation and sustainable medicinal musk utilization in traditional Asian traditional medicine. Methods of focal sampling and all-occurrence recording were used to evaluate the intensity of stereotypic behaviors and personality traits in 25 captive male forest musk deer. Additionally, musk secretion was monitored in this study, and muscone content was measured with gas chromatography, thereby analyzing the interrelationship between their stereotypic behavior, personality traits, and musk secretion. The results revealed no significant differences in stereotypic behaviors or personality traits across age groups (p > 0.05). Individuals with stereotypic behaviors showed a tendency toward secreting higher amounts of musk and muscone content compared to those without stereotypic behaviors, although these differences were not statistically significant (p > 0.05). Furthermore, the exploratory behavior level and active behavior level were not significantly correlated with the secretion amount of musk. However, both the exploratory behavior level and active behavior level exhibited significant positive correlations with muscone content (p < 0.05). These findings provide valuable insights for the breeding, welfare, and ex situ conservation of endangered forest musk deer. Full article

Reproductive dysfunction in captive-bred males of the flatfish Solea senegalensis remains a major bottleneck for its aquaculture. To clarify the molecular basis underlying these impairments, we performed an integrated analysis of transcriptomes, proteomes and methylomes from gonads of wild-type individuals and first-generation (F1) captive fish of both sexes. Nineteen RNA-seq libraries and eighteen LC–MS/MS proteomes were generated, allowing the quantification of more than 32,000 genes and 2221 proteins. Differential expression and principal component analyses revealed that sex was the primary driver of molecular variation, whereas origin (F1 vs. wild-type) had a more moderate effect. Multi-omics integration showed a partial and comparison-dependent correspondence between RNA and protein levels, with a marked RNA–protein decoupling in F1 males. Despite this limited concordance, functional enrichment analyses identified consistent regulation of key biological processes, including translation, energy metabolism, and reproductive pathways such as gametogenesis, fertilization, and early embryonic development. Within this regulatory framework, previously characterized DNA methylation landscapes in gonadal tissue suggest an additional epigenetic layer modulating the transcriptional potential of reproductive genes, particularly in captive-bred males. F1 males exhibited coordinated down-regulation of reproductive functions across omic layers, consistent with altered post-transcriptional and post-translational regulation. Overall, this study provides the first comprehensive multi-omics framework integrating transcriptomic, proteomic, and epigenetic information in S. senegalensis gonads, offering mechanistic insights into the molecular basis of reproductive dysfunction in F1 broodstock and supporting future strategies to improve reproductive performance in aquaculture. Full article

A growing body of evidence indicates that the gut microbiota has a role in the mating preference process in mammals. This likely occurs through the modulation of various mating signals induced by symbiotic bacteria, thereby leading to variations in mating behavior. Given that giant pandas are solitary wild animals that rely on chemical signals for mate selection, it is relevant to explore whether the mating behavior of giant pandas is also affected by the gut microbiota. We hypothesize that antibiotic treatment-induced residual antibiotic resistance genes in captive giant pandas may disrupt intestinal microbiota homeostasis, diminish the abundance of beneficial microorganisms involved in short-chain fatty acid synthesis, and consequently impair nervous system function via the gut–brain axis. The ensuing physiological stress is likely to suppress innate mating behavior and compromise pheromone synthesis, thereby reducing an individual’s attractiveness to potential mates. To answer this question, we utilize fecal metagenomics technology to analyze the differences in gut microbes and antibiotic resistance genes (ARGs) between captive male adult giant pandas displaying natural versus non-natural mating behavior. The research findings suggest that, when compared with captive adult male giant pandas demonstrating natural mating behavior, those with non-natural mating behavior exhibit a significantly reduction in the abundance of beneficial gut microorganisms (s_Clostridium sp. and f_Ruminococcaceae) (p < 0.05). Concurrently, there is a significantly increase in the observed resistance genes tetO and mgtA, which are mainly associated with macrolide and tetracycline resistance (p < 0.05). Furthermore, Kegg functional analysis reveals a significant up-regulation of metabolic pathways related to sensory systems, such as taste and olfactory transduction, in the intestines of captive adult male giant pandas showing natural mating behavior. These results imply that changes in the abundance of gut microbiota and ARGs are correlated with the manifestation of natural mating behavior in captive adult male giant pandas. Consequently, to improve the success rate of natural reproduction within the male giant panda populations in captive environments, it is advisable to administer antibiotics judiciously and closely monitor the composition of beneficial bacteria in their gut microbiota. The findings of this study provide novel perspectives on the mechanisms by which captive conditions affect the decline in natural mating behavior observed in adult male giant pandas. Full article

The tiger (Panthera tigris) is an apex predator and plays a fundamental role in sustaining biodiversity through its native range in Asia. By controlling populations of large herbivores and mesopredators, tigers help maintain the structural integrity of habitats, thereby supporting a diverse array of flora and fauna. Despite its ecological importance, the tiger is one of the most threatened large carnivores globally. It is classified as Endangered on the IUCN Red List, although threat categories vary among subspecies, and it is listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which covers all tiger subspecies. Over the past two decades, global tiger populations have declined by more than 90%. Consequently, they have become the focus of conservation efforts, including captive breeding and reintroduction initiatives. However, the reintroduction of captive-bred tigers into natural habitats presents significant scientific and logistical challenges. This review synthesizes current knowledge on the complexities of using captive tigers for reintroduction programs, with particular attention to welfare and behavioral competence of captive individuals, and genetic diversity and health of founder populations. It further addresses critical considerations for habitat suitability and managing potential human-tiger conflict and evaluates the overall effectiveness and feasibility of tiger reintroduction as a conservation strategy. Full article

This study examines risky decision-making in a free-ranging population of Balinese long-tailed macaques (Macaca fascicularis fascicularis), addressing gaps in research that have largely focused on captive primates and have rarely considered individual differences by age and sex. Thirty-three macaques of different age–sex classes were tested using a choice task contrasting a guaranteed small reward with a probabilistic larger reward. At the group level, macaques showed no preference for safe or risky options. However, substantial individual variation emerged: some individuals were risk-prone, others risk-averse, and many indifferent. Notably, age and sex interacted in shaping risk preferences. Among males, adults and juveniles were more risk-prone than younger adults, whereas among females, adults were more risk-prone than juveniles. Juveniles also displayed outcome-dependent flexibility, choosing the risky option more often after a previous successful risky choice, consistent with a win–stay strategy. Like in rodents, this pattern may reflect adaptive learning during developmental transitions. Importantly, the observed behavioral differences were not due to misunderstanding of the task, as macaques reliably chose the larger option when outcomes were visible. This pronounced individual variability in primate risk preferences underscore the importance of considering demographic factors when characterizing species-typical risk preferences. Full article

The memoirs of Baron Wenceslas Wratislaw are among the most significant Western sources portraying the Ottoman Empire in the late 16th century. Sent on a diplomatic mission and later taken captive, Wratislaw offers a dual image of the Empire: as a powerful, well-organised state and as a despotic regime evoking fear. His account reveals two contrasting perceptions of the Ottoman court and administration. While their rigid authoritarianism challenged Western admiration for Ottoman governance, it also reinforced existing notions of Oriental despotism. The shifting diplomatic conduct and hostile treatment of the Bohemian delegation further shaped the Ottomans as unreliable and deceptive in Western eyes. Culturally, Wratislaw presents the Ottomans as “the other civilization,” highlighting differences in religion, lifestyle, and social structure. Yet he also acknowledges their hospitality, generosity, and religious tolerance. This study examines how Wratislaw’s personal experiences reflect broader Western imaginations of the Ottoman world. It argues that cultural and diplomatic encounters shaped a complex and often ambivalent image, influenced by both structural dynamics and individual perspectives. Positioned at the intersection of historical sociology and imagology, the article contributes to the understanding of cross-cultural perception in early modern diplomacy. Full article

The world is constantly challenged by complex crises—from the COVID-19 pandemic and geopolitical tensions to economic uncertainty and severe environmental disasters. During these critical times, individuals need to reflect on ethical values and demonstrate responsible decision-making, integrity, and preparedness to mitigate the impact of future crises. Education can play an instrumental role in these endeavours. This study presents the user experience and usability evaluation of PREPARED App—an educational mobile application developed to raise users’ awareness on the ethical dimensions of global challenges through real-life case studies. The captivating narratives, clear structure, ease-of-use, and multimedia content were reported as key strengths of the mobile app by both users (n = 54) and experts (n = 4). Suggestions were also captured for enriching the learning experience through enhanced customisation options, personalised feedback mechanisms, and accessibility features. A set of pedagogical guidelines is extracted to enable instructional designers, educators, and mobile application developers to create accessible and engaging mobile learning experiences. Full article

Age-related changes throughout the lifespan are known to influence gut microbiota composition, microbial functional potential, and host-associated metabolic processes. Understanding these age-related variations is important for elucidating their potential physiological implications at different life stages. However, information regarding the gut microbiome and metabolomic characteristics of super-geriatric captive giant pandas (Ailuropoda melanoleuca) remains limited. In this study, fecal samples were collected from adult and super-geriatric captive giant pandas and analyzed using metagenomic sequencing combined with untargeted metabolomics. The gut microbiota of super-geriatric individuals exhibited a marked decrease in Bacillota and an enrichment of Pseudomonadota compared with adult individuals. Functional profiling revealed age-associated shifts in microbial metabolic potential, with a transition from biosynthesis-dominated pathways toward pathways related to substrate degradation and energy utilization. Metabolomic analyses further revealed pronounced metabolic alterations in super-geriatric giant pandas, including elevated levels of unsaturated fatty acids and changes in bile acid–related metabolites. Alterations in gut microbiota composition, particularly the relative enrichment of Pseudomonadota-associated taxa, were associated with inflammation-related metabolic features. Collectively, these findings indicate coordinated changes in gut microbial composition and metabolic profiles during aging. Overall, this study characterizes age-associated alterations in gut microbiota structure and fecal metabolic signatures in super-geriatric captive giant pandas, providing a scientific basis for future studies on microbiota–metabolism interactions and for improving nutritional management and health monitoring strategies in aged individuals of this endangered species. Full article

Determining hematological values is essential to provide baseline health and condition data. We evaluated the hematological parameters of free-living individuals of Caiman crocodilus and Melanosuchus niger from the middle Negro River region of Brazil. We captured 18 C. crocodilus and 16 M. niger. Blood was drawn using syringes containing 10% EDTA, and blood parameters were determined as previously described. The analyzed erythrocyte parameters were similar across the species, demonstrating that, despite their different sizes, they share similar strategies for oxygen absorption and transport in the blood. In the morphological analysis of blood cells, erythrocytes, erythroblasts, thrombocytes, lymphocytes, neutrophils, azurophils, heterophils, and basophils were found, and, in the quantification of leukocytes and thrombocytes, it was noted that lymphocytes are the central cells in the blood of the Amazonian caiman. In the plasma metabolite results, no significant differences were observed between glucose and total protein levels. Key physiological parameters were established to assess the health of C. crocodilus and M. niger, enabling the application of this information to sustainable captive production programs and helping to reduce pressure on wild populations. Full article

Illegal wildlife trade exerts severe pressure on wild parrot populations, and confiscated parrots often end up in rescue centers where they are rehabilitated for release. However, parrots kept in captivity often develop potentially maladaptive behaviors, including attraction to humans. This behavior can increase the risk of recapture. We modified and tested a previously published human aversion training (HAT) protocol designed to reduce human attraction in confiscated Amazona parrots. The HAT consisted of observers either on the ground or on a ladder, offering food to a single individual and then feigning capture of birds that approached or failed to move away from the observer. Twelve Yellow-naped Amazons (Amazona auropalliata) underwent 36 sessions of HAT over a 14-week period. Ten additional birds were held without training as a control. All birds were evaluated through food offer tests (FOTs) before, during, and after the experiment (FOT scores ranged from 1 when the bird approached the observer to 6 when the bird flew away). Over the training period, both groups showed increased aversion to people. However, contrary to our predictions, aversion scores were not higher for the group given aversion training. Aversion training also did not have a strong impact on fate post-release: within a month of release, 40% of the 22 birds were recaptured in a nearby village, including 4 treatment and 5 control birds. Overall, these results suggest that holding these birds in monospecific groups increased aversion to humans. However, the intense training aversion protocol did not further increase the fear of humans in these Amazona parrots, many of which may have been pets for years before entering the program. This study suggests that rehabilitation and release projects should regularly evaluate the impacts of their training programs and improve or eliminate costly protocols that do not achieve stated objectives. Full article

When analyzing the long-term viability of small, declining populations, it is essential to recognize that inbreeding and the erosion of genetic diversity are primarily driven by the effective population size, which is often a fraction of the total census count. The globally endangered Lear’s macaw (Anodorhynchus leari) is a restricted-range species endemic to the Caatinga ecoregion in NE Brazil. This species was only known in captivity due to wildlife illegal trade, until 1978, when a small population close to extinction was discovered in the wild, estimated at ca. 60 individuals in 1983. Conservation efforts have allowed for population recovery in recent decades, reaching a population of ca. 2273 individuals in 2022. Given these drastic population changes, a genetic assessment is important to empower conservation strategies with knowledge about the level of genetic variability, population genetic structure, inbreeding levels, and demographic history. We used a set of eight species-specific microsatellites to provide the first genetic assessment of the wild population of this species by genotyping non-invasive samples (molted feathers) collected in the known breeding and roosting sites of the species. Our results revealed a low effective population size (N_e = 49–80), which represents the main conservation concern. We also observed evidence of past bottlenecks. However, moderate levels of genetic diversity, no evidence of inbreeding, and a wide connectivity across the study area confirm a single population and set the ground for the potential natural recovery of this species and the recolonization of breeding sites across its former range. Full article