Small Population Size Research Articles

Population age structure and conservation status of Ferula sinkiangensis (Apiaceae) in Xinjiang, China

Abstract Ferula sinkiangensis K.M. Shen is a threatened medicinal plant endemic to Xinjiang, China, with a small population size and a narrow distribution range. We assessed the status of this species with respect to its population age structure, the level of threat and extinction risk. Only one population remains, in Yining County, Xinjiang. We conducted field surveys of the population in 2022 and 2023, counting 2,033 and 1,515 individuals, respectively, in 144 sample quadrats. We assessed the age structure of the population by counting the number of basal leaves of each individual. The frequency distribution had an inverted J-shape, indicative of a relatively stable age structure. However, the number of mature individuals was small, raising concerns about the risk of genetic drift and inbreeding. This species is also threatened by habitat destruction and inappropriate collection practices. We recommend that F. sinkiangensis is categorized as Critically Endangered on the IUCN Red List on the basis of criteria B2ab(iii), C2a(i) and D.

The Thoughtful program: a randomized controlled study of a mentalization-based mental health education intervention in a psychiatric outpatient population

Background P-factor and mentalizing theory and research set perspectives for transdiagnostic psychiatric treatments. Aims To test the effects of a low-cost mentalization-based health education program (the Thoughtful program) in an unselected waiting list population, from a psychiatric outpatient clinic in North Norway. Methods Waiting list patients were randomized (1:1 allocation): 79 patients in the control group were offered standard individual assessment and treatment. Seventy-nine patients in the intervention group were offered a one-day (six-hour) group-based Thoughtful course, plus individual assessment, and treatment. Results During a 6-month follow-up period, the number of patients in active assessment and treatment was 66% higher in the control group than in the intervention group. Self-reported patient questionnaire scores on mentalizing, well-being and suicidal ideation scores showed no significant changes in the control group. In the intervention group, significant changes were reported: Mentalizing scores improved by 72% and well-being scores improved by 55%. Suicidal ideation scores were not significantly changed. No adverse effects were registered. Limitations The results from this study should be interpreted with caution because of a small population size and low questionnaire response rate. The follow up period was limited to 6 months. Transfer of program information from intervention group patients to control group patients could not be guaranteed. It may be considered a limitation that diagnostic pattern analysis was not included in the study. Conclusions A low-cost transdiagnostic mentalization-based educational program in an outpatient psychiatry clinic may improve patient mentalizing and wellbeing without adverse effects and reduce the use of hospital services.

The Impact of Capital Structure, Company Size, and Good Corporate Governance on Financial Performance and Company Value

This study aims to resolve the inconsistencies in prior research regarding the effects of capital structure, firm size, and good corporate governance (GCG) on company value. Additionally, it investigates the moderating role of corporate social responsibility (CSR) in the relationship between financial performance and company value, offering new insights into this dynamic interaction. This study utilizes a saturated sample or census approach, including all population members, due to the small population size and the researcher's ability to access the required data. Data from 71 manufacturing companies listed on the Indonesia Stock Exchange (IDX) between 2018 and 2022 were obtained from their financial statements and annual reports. A quantitative analysis was conducted using Partial Least Square (PLS) regression with the SmartPLS 4.0 software. The results indicate that capital structure, company size, and GCG significantly impact financial performance. Additionally, capital structure was found to significantly affect company value, while company size and GCG did not. Financial performance significantly influenced company value, but CSR did not directly affect company value and did not moderate the relationship between financial performance and company value.

Faecal DNA Metabarcoding for Diet Analysis of Endangered Fish Species, Odontobutis obscurus

Understanding the ecological characteristics of endangered species is essential for their management and conservation. The dark sleeper (Odontobutis obscurus) is a carnivorous freshwater fish that has been designated an endangered species in South Korea because of its highly restricted habitat range and small population size. However, ecological research on prey items for this species remains severely limited globally, posing challenges for establishing conservation measures such as translocation management. In this study, the food sources and feeding strategies of O. obscurus were identified through non-invasive faecal DNA metabarcoding. A total of 24 O. obscurus specimens were collected from Sanyang Stream on Geoje Island, and faecal DNA was amplified using mitochondrial cytochrome c oxidase I (COI) primer. As a result, 13 prey items were identified, comprising fish and benthic invertebrates. Dietary metrics revealed the overall food composition and major food source of O. obscurus, and the Costello method enabled graphical diet analysis, suggesting that O. obscurus is a generalist, feeding on a wide variety of food sources. The food selectivity index suggested that O. obscurus prefers specific prey items, such as genus Misgurnus, Zacco (fish), Radix (gastropod), and Ephemera (mayfly). This molecular method facilitated the diet analysis of an endangered fish species that cannot undergo dissection, providing crucial information for their management, particularly regarding translocation efforts.

Too big to purge: persistence of deleterious Mutations in Island populations of the European Barn Owl (Tyto alba).

A key aspect of assessing the risk of extinction/extirpation for a particular wild species or population is the status of inbreeding, but the origin of inbreeding and the current mutational load are also two crucial factors to consider when determining survival probability of a population. In this study, we used samples from 502 barn owls from continental and island populations across Europe, with the aim of quantifying and comparing the level of inbreeding between populations with differing demographic histories. In addition to comparing inbreeding status, we determined whether inbreeding is due to non-random mating or high co-ancestry within the population. We show that islands have higher levels of inbreeding than continental populations, and that this is mainly due to small effective population sizes rather than recent consanguineous mating. We assess the probability that a region is autozygous along the genome and show that this probability decreased as the number of genes present in that region increased. Finally, we looked for evidence of reduced selection efficiency and purging in island populations. Among island populations, we found an increase in numbers of both neutral and deleterious minor alleles, possibly as a result of drift and decreased selection efficiency but we found no evidence of purging.

Rapid evolution of mitochondrion-related genes in haplodiploid arthropods

BackgroundMitochondrial genes and nuclear genes cooperate closely to maintain the functions of mitochondria, especially in the oxidative phosphorylation (OXPHOS) pathway. However, mitochondrial genes among arthropod lineages have dramatic evolutionary rate differences. Haplodiploid arthropods often show fast-evolving mitochondrial genes. One hypothesis predicts that the small effective population size of haplodiploid species could enhance the effect of genetic drift leading to higher substitution rates in mitochondrial and nuclear genes. Alternatively, positive selection or compensatory changes in nuclear OXPHOS genes could lead to the fast-evolving mitochondrial genes. However, due to the limited number of arthropod genomes, the rates of evolution for nuclear genes in haplodiploid species, besides hymenopterans, are largely unknown. To test these hypotheses, we used data from 76 arthropod genomes, including 5 independently evolved haplodiploid lineages, to estimate the evolutionary rates and patterns of gene family turnover of mitochondrial and nuclear genes.ResultsWe show that five haplodiploid lineages tested here have fast-evolving mitochondrial genes and fast-evolving nuclear genes related to mitochondrial functions, while nuclear genes not related to mitochondrion showed no significant evolutionary rate differences. Among hymenopterans, bees and ants show faster rates of molecular evolution in mitochondrial genes and mitochondrion-related nuclear genes than sawflies and wasps. With genome data, we also find gene family expansions and contractions in mitochondrion-related genes of bees and ants.ConclusionsOur results reject the small population size hypothesis in haplodiploid species. A combination of positive selection and compensatory changes could lead to the observed patterns in haplodiploid species. The elevated evolutionary rates in OXPHOS complex 2 genes of bees and ants suggest a unique evolutionary history of social hymenopterans.

Population connectivity and size reductions in the Anthropocene: the consequence of landscapes and historical bottlenecks in white forsythia fragmented habitats

BackgroundWhite forsythia (Abeliophyllum distichum) is an endangered Korean Peninsula endemic that has been subjected to recent population genomics studies using SNPs via RAD sequencing. Here, we primarily employed the often underutilized haplotype information from RAD loci to further describe the species’ previously uninvestigated haplotype-based genomic variation and structure, and genetic-geographic characteristics and gene flow patterns among its five earlier identified genetic groups. We also inferred the time of past events that may have impacted the effective population size of these groups, as well as the species’ potential future distribution amidst the warming climate and anthropogenic threats.ResultsOur findings emphasized the recognition of the species’ regional patterns of genetic structure, and the role of topography and its associated gene flow patterns as some of the possible factors that may have influenced the species’ present-day fragmented population distribution. The inferred bottleneck events during the Anthropocene, some of which aligned with the time of historical catastrophic events on the Peninsula (e.g., the Korean War), were revealed to have contributed to the generally low effective population size of its five lineages, particularly those with marginal distributional range. Future distribution under both optimistic and pessimistic climatic scenarios suggests unlikely suitable habitats for these populations to expand from their current range limits, at least in the next 80 years.ConclusionsThe small effective population size and landscape-driven limited gene flow among white forsythia populations will remain a big challenge for the conservation management of the species’ already fragmented population distribution. To help mitigate these impacts, the merging of various research approaches and the use of genomic data to their full potential is recommended to provide the optimized knowledge-based tools for the conservation of this endangered species, and other similar plants under pressure.

Genomic adaptation to small population size and saltwater consumption in the critically endangered Cat Ba langur

Many mammal species have declining populations, but the consequences of small population size on the genomic makeup of species remain largely unknown. We investigated the evolutionary history, genetic load and adaptive potential of the Cat Ba langur (Trachypithecus poliocephalus), a primate species endemic to Vietnam’s famous Ha Long Bay and with less than 100 living individuals one of the most threatened primates in the world. Using high-coverage whole genome data of four wild individuals, we revealed the Cat Ba langur as sister species to its conspecifics of the northern limestone langur clade and found no evidence for extensive secondary gene flow after their initial separation. Compared to other primates and mammals, the Cat Ba langur showed low levels of genetic diversity, long runs of homozygosity, high levels of inbreeding and an excess of deleterious mutations in homozygous state. On the other hand, genetic diversity has been maintained in protein-coding genes and on the gene-rich human chromosome 19 ortholog, suggesting that the Cat Ba langur retained most of its adaptive potential. The Cat Ba langur also exhibits several unique non-synonymous variants that are related to calcium and sodium metabolism, which may have improved adaptation to high calcium intake and saltwater consumption.

Zingiber baumii Chatan & Promprom: A New Species of Zingiberaceae From Thailand.

Zingiber baumii Chatan & Promprom, a new species from the Zingiberaceae family, is described from Sakon Nakhon Province in northeastern Thailand. This species was identified during field expeditions conducted between 2018 and 2024 in Phu Pha Yol National Park. The morphological characteristics of Z. baumii, such as red or pinkish-red leaf sheaths, leaf blades (1.5-) 2.0-3.0 cm wide, pink petioles, and bright yellow corolla with a red patch, distinguish it from closely related species such as Z. isanense Triboun & K. Larsen. Zingiber baumii grows in slightly shaded dry dipterocarp forests at elevations of 300-380 m. The preliminary conservation assessment indicates that this species should be classified as Endangered (EN) according to IUCN criteria due to its limited distribution and small population size. Detailed morphological comparisons with related species are provided, along with illustrations and habitat descriptions.

Evolution and spatiotemporal analysis of earthquake public opinion based on social media data

As critical conduits for the dissemination of online public opinion, social media platforms offer a timely and effective means for managing emergencies during major disasters, such as earthquakes. This study focuses on the analysis of online public opinions following the Maduo M7.4 earthquake in Qinghai Province and the Yangbi M6.4 earthquake in Yunnan Province. By collecting, cleaning, and organizing post-earthquake Sina Weibo (short for Weibo) data, we employed the Latent Dirichlet Allocation (LDA) model to extract information pertinent to public opinion on these earthquakes. This analysis included a comparison of the nature and temporal evolution of online public opinions related to both events. An emotion analysis, utilizing an emotion dictionary, categorized the emotional content of post-earthquake Weibo posts, facilitating a comparative study of the characteristics and temporal trends of online public emotions following the earthquakes. The findings were visualized using Geographic Information System (GIS) techniques. The analysis revealed certain commonalities in online public opinion following both earthquakes. Notably, the peak of online engagement occurred within the first 24 hours post-earthquake, with a rapid decline observed between 24 to 48 hours thereafter. The variation in popularity of online public opinion was linked to aftershock occurrences. Adjusted for population factors, online engagement in areas surrounding the earthquake sites and in Sichuan Province was significantly high. Initially dominated by feelings of “fear” and “surprise”, the public sentiment shifted towards a more positive outlook with the onset of rescue operations. However, distinctions in the online public response to each earthquake were also noted. Following the Yangbi earthquake, Yunnan Province reported the highest number of Weibo posts nationwide; in contrast, Qinghai Province ranked third post-Maduo earthquake, attributable to its smaller population size and extensive damage to communication infrastructure. This research offers a methodological approach for the analysis of online public opinion related to earthquakes, providing insights for the enhancement of post-disaster emergency management and public mental health support.

Quality and Processability of Meat in Polish Native Pigs – A Review

Abstract The primary aim of pig breeding efforts is to produce animals characterized by outstanding performance, including also fattening and slaughter performance traits. However, improved carcass leanness and reduced carcass fatness, especially intramuscular fat content, have led to a deterioration of pork quality and processability. Due to the growing frequency of meat defects and the limited potential use of such meat in the production of premium products this constitutes a considerable problem for the meat industry. The breeds superior in terms of meat quality are native pig breeds, such as those kept in Poland, i.e. Pulawska (Pul), Zlotnicka Spotted (ZS) and Zlotnicka White (ZW) pigs. The aim of this paper is to present a review of research results concerning quality and processability of meat produced by the Polish native pig breeds. The presented results indicate that pigs of local breeds exhibit a low level of performance traits (daily gain, carcass leanness, backfat thickness) while maintaining very good parameters of meat quality and processability (muscle composition and physical properties, fatty acids profile, sensory traits). Thus, they are used as a source material for premium products. In view of the small size of local populations and higher production costs in Poland it is a niche production. Therefore, the current aim of breeding indigenous breeds is both to maintain a safe population size and genetic diversity and to increase popularity of their meat and processed meat products among consumers. This objective is attained, among other things, thanks to efforts to reduce cost of their production through optimization of environmental conditions and wider use of less expensive traditional feed formulations, which make it possible to fully utilize the potential of local pork resources.

Genetic characterisation of a recovered Italian chicken breed: the Millefiori Piemontese

The recent rediscovering of the Millefiori Piemontese breed, previously considered as extinct, has led to its genetic characterisation: establishing the basis for its recovery and preservation. This study describes the morpho-biometric traits and compares the genetic variability of the Millefiori Piemontese breed with that of other local chicken breeds using 26 microsatellite markers. A subset of 14 markers was used to compare the genetic variation of the Millefiori Piemontese breed with that of two other Piedmontese chicken breeds (Bionda Piemontese and Bianca di Saluzzo) as well as 17 Italian and 2 commercial hybrids, whose genetic variability has already been investigated. The present study confirmed the sexual dimorphism and assessed the genetic variability of the Millefiori Piemontese in terms of number of alleles/locus (Na = 4), the effective number of alleles (Nea = 3), observed (Ho = 0.56) and expected heterozygosity (He = 0.53), self-coancestry (IB = 0.65), potential extinction risk (ERI = 2), and its contribution to the Italian poultry biodiversity (GDT = −0.60). The results indicate that, despite its small population size (Ne = 56), the Millefiori Piemontese population exhibits significant genetic diversity, making it a valuable resource for breeding programs focused on preserving the breed and safeguarding its biodiversity. This study is the first to investigate the genetic variability of the Millefiori Piemontese breed and compare it with other local poultry breeds. The findings highlight the genetic uniqueness of the Millefiori breed and its significant contribution to the biodiversity of chickens in Piedmont and Italy, emphasising the importance of its conservation.

Towards geospatially-resolved public-health surveillance via wastewater sequencing

Wastewater is a geospatially- and temporally-linked microbial fingerprint of a given population, making it a potentially valuable tool for tracking public health across locales and time. Here, we integrate targeted and bulk RNA sequencing (N = 2238 samples) to track the viral, bacterial, and functional content over geospatially distinct areas within Miami Dade County, USA, from 2020-2022. We used targeted amplicon sequencing to track diverse SARS-CoV-2 variants across space and time, and we found a tight correspondence with positive PCR tests from University students and Miami-Dade hospital patients. Additionally, in bulk metatranscriptomic data, we demonstrate that the bacterial content of different wastewater sampling locations serving small population sizes can be used to detect putative, host-derived microorganisms that themselves have known associations with human health and diet. We also detect multiple enteric pathogens (e.g., Norovirus) and characterize viral diversity across sites. Moreover, we observed an enrichment of antimicrobial resistance genes (ARGs) in hospital wastewater; antibiotic-specific ARGs correlated to total prescriptions of those same antibiotics (e.g Ampicillin, Gentamicin). Overall, this effort lays the groundwork for systematic characterization of wastewater that can potentially influence public health decision-making.

Regional variation in low-value musculoskeletal surgery: a nationwide study from the Finnish Care Register

Background and purpose: Healthcare systems globally are grappling with resource constraints and rising costs. Concerns have been raised about “low-value” care, which consumes healthcare resources without benefiting patients. We aimed to examine regional differences in common low-value musculoskeletal surgeries in Finland and explore explanatory factors behind the variation.Methods: Using data from the Finnish Care Register for Health Care, surgeries conducted from 2006–2007 compared with 2020–2021 were analyzed across 20 hospital districts. Selected surgeries (acromioplasty, rotator cuff repair, partial meniscectomy, wrist arthroscopy, ankle arthroscopy, and distal radius fracture fixation) were categorized based on NOMESCO procedure codes, and incidence rates in older populations were calculated based on population size derived from Statistics Finland.Results: We found substantial regional disparities in low-value surgeries. The incidence rates were higher in hospitals with high historical incidence rates and smaller population sizes, suggesting that the uptake of evidence is slower in small non-academic hospitals.Conclusion: The incidence of low-value surgery is declining but regional differences remain large. It is unlikely that regional variation in disease incidence explains such large variation in low-value surgery. Instead, local treatment culture seems to be the driving force behind low-value surgery, and the practices seem to be more entrenched in small hospitals.

Analysis of genotyping data reveals the unique genetic diversity represented by the breeds of sheep native to the United Kingdom

BackgroundSheep breeds native to the United Kingdom exhibit a striking diversity of different traits. Some of these traits are highly sustainable, such as seasonal wool shedding in the Wiltshire Horn, and are likely to become more important as pressures on sheep production increase in coming decades. Despite their clear importance to the future of sheep farming, the genetic diversity of native UK sheep breeds is poorly characterised. This increases the risk of losing the ability to select for breed-specific traits from native breeds that might be important to the UK sheep sector in the future. Here, we use 50 K genotyping to perform preliminary analysis of breed relationships and genetic diversity within native UK sheep breeds, as a first step towards a comprehensive characterisation. This study generates novel data for thirteen native UK breeds, including six on the UK Breeds at Risk (BAR) list, and utilises existing data from the publicly available Sheep HapMap dataset to investigate population structure, heterozygosity and admixture.ResultsIn this study the commercial breeds exhibited high levels of admixture, weaker population structure and had higher heterozygosity compared to the other native breeds, which generally tend to be more distinct, less admixed, and have lower genetic diversity and higher kinship coefficients. Some breeds including the Wiltshire Horn, Lincoln Longwool and Ryeland showed very little admixture at all, indicating a high level of breed integrity but potentially low genetic diversity. Population structure and admixture were strongly influenced by sample size and sample provenance – highlighting the need for equal sample sizes, sufficient numbers of individuals per breed, and sampling across multiple flocks. The genetic profiles both within and between breeds were highly complex for UK sheep, reflecting the complexity in the demographic history of these breeds.ConclusionOur results highlight the utility of genotyping data for investigating breed diversity and genetic structure. They also suggest that routine generation of genotyping data would be very useful in informing conservation strategies for rare and declining breeds with small population sizes. We conclude that generating genetic resources for the sheep breeds that are native to the UK will help preserve the considerable genetic diversity represented by these breeds, and safe-guard this diversity as a valuable resource for the UK sheep sector to utilise in the face of future challenges.

An estimate of fitness reduction from mutation accumulation in a mammal allows assessment of the consequences of relaxed selection.

Each generation, spontaneous mutations introduce heritable changes that tend to reduce fitness in populations of highly adapted living organisms. This erosion of fitness is countered by natural selection, which keeps deleterious mutations at low frequencies and ultimately removes most of them from the population. The classical way of studying the impact of spontaneous mutations is via mutation accumulation (MA) experiments, where lines of small effective population size are bred for many generations in conditions where natural selection is largely removed. Such experiments in microbes, invertebrates, and plants have generally demonstrated that fitness decays as a result of MA. However, the phenotypic consequences of MA in vertebrates are largely unknown, because no replicated MA experiment has previously been carried out. This gap in our knowledge is relevant for human populations, where societal changes have reduced the strength of natural selection, potentially allowing deleterious mutations to accumulate. Here, we study the impact of spontaneous MA on the mean and genetic variation for quantitative and fitness-related traits in the house mouse using the MA experimental design, with a cryopreserved control to account for environmental influences. We show that variation for morphological and life history traits accumulates at a sufficiently high rate to maintain genetic variation and selection response. Weight and tail length measures decrease significantly between 0.04% and 0.3% per generation with narrow confidence intervals. Fitness proxy measures (litter size and surviving offspring) decrease on average by about 0.2% per generation, but with confidence intervals overlapping zero. When extrapolated to humans, our results imply that the rate of fitness loss should not be of concern in the foreseeable future.

Acetabular revision for iliopsoas impingement: a study of 55 cases at 3 years of follow-up. Does the procedure achieve the Minimal Clinically Important Difference (MCID) in the Oxford-12 score in more than 80% of cases?

IntroductionSeveral surgical options can be offered to manage iliopsoas impingement. Research published on cup replacements often concerns a small population size or multicentre studies, suggesting a variety of indications. We conducted a retrospective single centre study screening according to a specific protocol of a population of patients who had a cup replacement for iliopsoas impingement. The objectives were: 1) to specify the functional outcomes and the achievement of the Minimal Clinically Important Difference (MCID) and the Patient Acceptable Symptom State (PASS) according to the Oxford-12 score, and 2) to assess the complication rate. HypothesisOur hypothesis was that acetabular replacements achieve a Minimal Clinically Important Difference (MCID) in more than 80% of cases. Patients and methodsFifty-five hips underwent acetabular revision between 2011 and 2020. Forty-three were performed as first-line surgery, eight after failed tenotomy and four after failed anterior hip capsule thickening plasty. A CT scan of all the hips revealed a median overhang of 9 mm (7; 12) and a 7 ° cup anteversion (2; 19). Follow-up included assessment of the Oxford-12 score using MCID and PASS, the Merle d'Aubigné score, an assessment of hip flexion muscle strength using the Medical Research Council scale, and an assessment of satisfaction and complications. ResultsAt a mean follow-up of 3 years (2–10), the difference in the Oxford score before and at follow-up was 18 points (15; 27) (p < 0.001), the median Medical Research Council score was 4.5 (4; 5) and patients were satisfied or very satisfied in 73% of cases (40/55). The MCID was achieved for 87% of the hips (48/55), and the PASS was achieved in 67% of cases (33/55). The rate of complications involving surgical revision was 10.9% (6/55) with respectively: two anterior dislocations, one early infection on day 10 resolved after wound irrigation and appropriate antibiotic therapy, one intraoperative fracture of the trochanter requiring osteosynthesis and one arthroscopic revision to remove a free cement fragment. ConclusionDue to a good functional outcome but a high complication rate, a cup replacement can be offered for iliopsoas impingement associated with acetabular malposition or significant overhang. Level of evidenceIV.

Beyond population size: whole-genome data reveal bottleneck legacies in the peninsular Italian wolf.

Preserving genetic diversity and adaptive potential while avoiding inbreeding depression is crucial for the long-term conservation of natural populations. Despite demographic increases, traces of past bottleneck events at the genomic level should be carefully considered for population management. From this perspective, the peninsular Italian wolf is a paradigmatic case. After being on the brink of extinction in the late 1960s, peninsular Italian wolves rebounded and recolonized most of the peninsula aided by conservation measures, including habitat and legal protection. Notwithstanding their demographic recovery, a comprehensive understanding of the genomic consequences of the historical bottleneck in Italian wolves is still lacking. To fill this gap, we sequenced whole genomes of thirteen individuals sampled in the core historical range of the species in Central Italy to conduct population genomic analyses, including a comparison with wolves from two highly-inbred wolf populations (i.e., Scandinavia and Isle Royale). We found that peninsular Italian wolves, despite their recent recovery, still exhibit relatively low genetic diversity, a small effective population size, signatures of inbreeding, and a non-negligible genetic load. Our findings indicate that the peninsular Italian wolf population is still susceptible to bottleneck legacies, which could lead to local inbreeding depression in case of population reduction or fragmentations. This study emphasizes the importance of considering key genetic parameters to design appropriate long-term conservation management plans.

Demographic drivers of reproductive failure in a threatened bird: Insights from a decade of data

Hatching failure affects up to 77% of eggs laid by threatened bird species, yet the true prevalence and drivers of egg fertilization failure versus embryo mortality as underlying mechanisms of hatching failure are unknown. Here, using ten years of data comprising 4,371 eggs laid by a population of a threatened bird, the hihi (Notiomystis cincta), we investigate the relative importance of infertility and embryo death as drivers of hatching failure and explore population-level factors associated with them. We show that of the 1,438 eggs that failed to hatch (33% of laid eggs) between 2010 and 2020, 83% failed due to embryo mortality, with the majority failing in the early stages of embryonic development. In the most comprehensive estimates of infertility rates in a wild bird population to date, we find that fertilization failure accounts for around 17% of hatching failure overall and is more prevalent in years where the population is smaller and more male biased. Male embryos are more likely to die during early development than females, but we find no overall effect of sex on the successful development of embryos. Offspring fathered by within-pair males have significantly higher inbreeding levels than extra-pair offspring; however, we find no effect of inbreeding nor extra-pair paternity on embryo mortality. Accurately distinguishing between infertility and embryo mortality in this study provides unique insight into the underlying causes of reproductive failure over a long-term scale and reveals the complex risks of small population sizes to the reproduction of threatened species.

Evaluating outcomes of transjugular intrahepatic portosystemic shunt procedure among Native Americans

BackgroundThis study aims to explore racial disparities in immediate outcomes of Transjugular Intrahepatic Portosystemic Shunt (TIPS) among Native Americans, a group that have higher prevalence of liver cirrhosis but were the “invisible group” in previous TIPS studies due to their small population size. MethodsThe study identified Native Americans and Caucasians who underwent TIPS in National/Nationwide Inpatient Sample (NIS) database from Q4 2015–2020. Preoperative factors, including demographics, indications for TIPS, comorbidities, etiologies for liver disease, primary payer status, and hospital characteristics, were matched by 1:5 propensity score matching. In-hospital post-TIPS outcomes were then compared between the two cohorts. ResultsThere were 6,658 patients who underwent TIPS, where 101 (1.52 %) were Native Americans and 4,574 (68.70 %) were Caucasians. Native Americans presented as younger, with a lower socioeconomic status, and displayed higher rates of alcohol abuse and related liver diseases. After propensity-score matching, Native Americans had comparable in-hospital post-TIPS outcomes including mortality (8.33% vs 9.09 %, p = 1.00), hepatic encephalopathy (18.75% vs 25.84 %, p = 0.19), acute kidney injury (28.13% vs 30.62 %, p = 0.71), and other adverse events. Native Americans also had similar wait from admission to operation (2.15 ± 0.30 vs 2.87 ± 0.21 days, p = 0.13), hospital length of stay (7.43 ± 0.63 vs 8.62 ± 0.47 days, p = 0.13), and total costs (158,299 ± 14,218.2 vs 169,425 ± 8,600.7 dollars, p = 0.50). ConclusionNative Americans had similar immediate outcomes after TIPS compared to their propensity-matched Caucasians. While these results underscore effective healthcare delivery of TIPS to Native Americans, it is imperative to pursue further research for long-term post-procedure outcomes.