Incidence and outcomes for stroke in Ulaanbaatar, Mongolia, during 2019-21: a prospective population-based study.

BACKGROUND: In the absence of reliable data to quantify the burden of stroke, we aimed to determine the incidence and outcome of stroke through the conduct of a prospective population-based study in Ulaanbaatar, Mongolia, during 2019-21. METHODS: All cases of stroke were identified through surveillance of multiple overlapping sources of hospitalised, ambulatory, and deceased individuals, using standardised diagnostic criteria in adult (aged ≥16 years) residents of the six urban districts of Ulaanbaatar, Mongolia (population person-years, N=1 896 965) between Jan 1, 2019, and Dec 31, 2020. Data on sociodemography, medical history, and management were collected. Crude and standardised incidence were calculated for first-ever stroke and its major pathological subtypes, and reported with 95% CIs. Outcomes were 28-day case fatality ratios and functional recovery on the modified Rankin scale at 90 days and 1 year. FINDINGS: 3803 strokes in 3738 patients were identified, of which 2962 were first-ever incident cases (mean age 59 years [SD 13], 1161 [39·2%] females). Annual incidence of first-ever stroke (per 100 000) was 156·1 (95% CI 150·5-161·8) on a crude basis, 171·6 (157·5-185·6) when age-adjusted to the Mongolian population, and 140·3 (136·7-143·9) when age-adjusted to the world population. World-adjusted incidence of pathological subtypes were 66·6 (95% CI 64·8-68·3) for ischaemic stroke, 54·5 (53·0-56·1) for intracerebral haemorrhage, and 18·7 (18·3-19·1) for subarachnoid haemorrhage. Men were twice as likely to suffer ischaemic stroke and intracerebral haemorrhage as women, but the risks were similar for subarachnoid haemorrhage; these patterns were consistent across age-groups. The predominant risk factors were hypertension seen in 1363 (63·1%) of 2161, smoking in 596 (26·8%) of 2220, regular alcohol consumption in 533 (24·0%) of 2220, obesity in 342 (16·1%) of 2125, and diabetes in 282 (12·7%) of 2220. There was little use (0·9%) of thrombolysis for acute ischaemic stroke, partly due to delays in presentation after the onset of symptoms (median 16·0 h [IQR 3·0-48·0]). The 28-day case-fatality rate was 36·1% (95% CI 34·3-37·9) overall, and 14·8% (12·8-16·7) for ischaemic stroke, 52·9% (49·9-55·8) for intracerebral haemorrhage, and 54·3% (49·4-59·1) for subarachnoid haemorrhage. Corresponding figures for poor functional outcome at 1-year, defined by scores of 3-6 for death or dependency on the mRS, were 61·6% (95% CI 59·8-63·4), 47·5% (44·7-50·3), 77·0% (74·5-79·5), and 61·8% (57·0-66·5), respectively. INTERPRETATION: The urban population of Ulaanbaatar, Mongolia, has a high incidence of stroke, particularly for intracerebral haemorrhage and subarachnoid haemorrhage, from which half of patients die within 1 month and more than two-thirds are either dead or dependent at 90 days. Although the overall incidence of stroke is similar to other countries, it occurs at a mean age of 60 years, which is at least 10 years younger than in high-income countries. These epidemiological data can inform the implementation of future programmes and scale-up activities for the primary and secondary prevention of stroke, and in the organisation of systems of care. FUNDING: Science and Technology Foundation of the Ministry of Education, Culture, and Science of Mongolia and The George Institute for Global Health.

Rising Temperature and the Spatiotemporal Patterns of Foot and Mouth Disease of Livestock in Mongolia.

BACKGROUND: Climate change is projected to have cascading effects on the environment and thereby trigger effects on animal health, human health and wellbeing. Foot and Mouth Disease (FMD) is a highly contagious disease affecting cloven-hoofed animals that has had dramatic socioeconomic impacts on nomadic pastoralist communities who are increasingly vulnerable to environmental degradation and climate change. FMD outbreaks are occurring more frequently in Mongolia and the effects of climatic change, such as more droughts, increasing temperature, and changing snow fall patterns, are also becoming more obvious. METHODS: In this study we use spatiotemporal mapping and regression analyses to explore trends and associations between climate variables and FMD outbreaks across Mongolia from 2010 to 2020. RESULTS: We found that the number of days with temperature above 80 °F in a province in a given year was associated with having a FMD outbreak. None of the other climate variables were associated with FMD outbreaks at the provincial level. CONCLUSION: Given the projected increase in warming temperatures across Mongolia, there is a need to further explore the association between rising temperatures and FMD outbreaks to prevent FMD from having cascading impacts on nomadic herder communities. Mitigating approaches for herders to use to reduce the impact of rising number of hot days on FMD spread needs to be devised and governments in countries with nomadic herding communities should enact climate adaptation policies for them.

Epidemiology of tuberculosis in Mongolia: analysis of surveillance data, 2015-2019.

Mongolia has a high tuberculosis (TB) burden. Data from routine paper-based surveillance were used to describe the epidemiology of TB in Mongolia; the data included testing presumptive TB cases, TB notifications, drug-resistant cases, treatment outcomes and notifications in prisoners. The proportion of the population tested for TB increased between 2015 and 2019. The number and rate per 100 000 population of TB notifications decreased between 2015 and 2018 and then increased in 2019. Most TB notifications in 2019 were in the capital, Ulaanbaatar (59.3%), followed by the central (16.8%), Khangai (10.4%), east (8.5%) and west (5.0%) regions. About half of TB notifications nationally were bacteriologically confirmed (45.4% in 2015, 48.1% in 2019), with the proportion of bacteriologically confirmed TB per province or district varying from 0% to 66%. High TB notification rates were observed in 2019 for males aged 15-54 years (202 per 100 000population) and females aged 15-34 years (190 per 100 000 population). Treatment success for all forms of TB was 90% in 2019 but was below the 90% target for bacteriologically confirmed cases. Between 2015 and 2019, the number of RR/MDR-TB notifications ranged from 265 to 211. The Mongolian National Tuberculosis Programme needs to continue its efforts in TB control, to further increase the programmatic impact and reduce the TB burden. It is recommended that Mongolia continue to increase TB screening, the use of Xpert testing, contact investigations and preventive treatments, and targeting interventions to the high-burden areas identified in this subnational analysis.

Systematically exploring the performance of a self-developed Multi-InDel system in forensic identification, ancestry inference and genetic structure analysis of Chinese Manchu and Mongolian groups.

The insertion/deletion (InDel) polymorphism has promising applications in forensic DNA analysis. However, the insufficient forensic efficiencies of the present InDel-based systems restrict their applications in parentage testing, due to the lower genetic polymorphism of the biallelic InDel locus and the limited number of InDel loci in a multiplex amplification system. Here, we introduced an in-house developed system which contained 41 polymorphic Multi-InDel markers (equivalent to 82 InDels in total), to serve as an efficient and reliable tool for different forensic applications in the Manchu and Mongolian groups. We demonstrated that the new system exhibited potential efficiencies for personal identification, parentage testing, two-person DNA mixture interpretation and ancestry inference of intercontinental populations. Meanwhile, we explored the genetic backgrounds of the Manchu and Mongolian groups by conducting a series of population genetic analyses. We showed that the Manchu and Mongolian groups shared closer genetic relationships with East Asian populations, especially Han Chinese populations in northern China. Moreover, more similar genetic compositions were detected between the Manchu group and the northern Han populations in this study, suggesting that the Manchu group had higher genetic affinities with northern Han populations than the Mongolian group. Overall. this study provided the necessary evidence that these Multi-InDel genetic markers could play an important role in forensic applications.

Permafrost preservation reveals proteomic evidence for yak milk consumption in the 13th century.

Domesticated yaks endure as iconic symbols of high-altitude frozen landscapes, where herding communities depend on their high-fat milk, transport, dung, and natural fibers. While there is established proteomic evidence for ancient consumption of ruminant and horse milk in the mountains and steppes of northern Eurasia, yak dairy products have yet to be detected. Yak domestication and the species' dispersal from Tibet into the mountainous zones to the north are also poorly resolved due to a paucity of zooarchaeological data. To examine the potential of paleoproteomics to shed light on domesticated yak in Mongolia, we analyzed human dental calculus from Mongol era elite individuals recovered from permafrost burials in Khovsgol province, where people continue to herd yak to this day. We report the first evidence for yak dairy consumption, linked to local resource control. In addition, we confirm a large diversity of recovered whey, curd, tissue, and blood proteins, likely reflecting the excellent preservation conditions found at permafrost sites.

Water Quality, Toxicity and Diversity of Planktonic and Benthic Cyanobacteria in Pristine Ancient Lake Khubsugul (Hövsgöl), Mongolia.

For the first time, microcystin-producing cyanobacteria have been detected in Khubsugul, which is ancient, pristine and one of the world's largest lakes. The microcystin synthetase genes belonged to the genera Nostoc, Microcystis and possibly Snowella spp. No microcystins were found in the water of the lake. Using the HPLC-HRMS/TOF, five microcystin congeners were identified in biofilms from stony substrates sampled in the coastal zone. The concentration of microcystins in biofilms was low: 41.95 µg g-1 d. wt. by ELISA and 55.8 µg g-1 d. wt. using HPLC. The taxonomic composition of planktonic and benthic cyanobacterial communities was determined by means of microscopy and high-throughput sequencing of 16S rDNA amplicons. Nostocales cyanobacteria dominated benthos of Lake Khubsugul and Synechococcales-plankton. The abundance of cyanobacteria was low both in plankton and benthos; there was no mass development of cyanobacteria. Hydrochemical and microbiological analyses showed that the water in the lake was clean; the number of faecal microorganisms was significantly below the acceptable guideline values. Hydrochemical and hydrophysical parameters, and the concentration of chlorophyll a, were low and within the range of values recorded in the 1970s to 1990s, and corresponded to the oligotrophic state of the lake. There were no signs of anthropogenic eutrophication of the lake and no conditions for the cyanobacterial blooms.

Validation of the abbreviated version of the World Health Organization Quality of Life in Mongolia: a population-based cross-sectional study among adults in Ulaanbaatar.

There is currently no validated tool to measure the quality of life (QOL) in the Mongolian language. This study aimed to validate the Mongolian version of the World Health Organization Quality of Life - Brief (WHOQOL-BREF) questionnaire for the general population of Mongolia. The subjects were 301 adults aged 18-65 years selected randomly by a computer from 30 centers in 8 districts of Ulaanbaatar, Mongolia, in 2020. Reliability was measured using Cronbach's α and intraclass correlation coefficients. Convergent, discriminant, and construct validities were examined using exploratory and confirmatory factor analyses for a four-domain factor structure. Among the participants, 56.1% were women, 32.9% held a bachelor's degree or higher, 48.8% were employed, and 61.8% were married. The overall Cronbach's α coefficient of the WHOQOL-BREF questionnaire was 0.804. Correlations between the component scores of the WHOQOL-BREF ranged from 0.581-0.822. All items showed higher item-total correlations with their corresponding domains than with other domains, except the mobility item from the physical domain. Discriminative validity was evident in physical and psychological domains. Exploratory and confirmatory factor analyses revealed a four-factorial structure consisting of 24 items that provided an acceptable fit to the data (RMSEA=0.084; CFI=0.860). In conclusion, the Mongolian version of the WHOQOL-BREF demonstrated evidence of good reliability and validity for assessing QOL in the general population of Mongolia. These findings indicate that it allows the comparison of QOL of adults in Mongolia with those in other countries.

Sickness absence among employees of healthcare organizations in the public sector in Mongolia: A cross-sectional study.

OBJECTIVES: This study aimed to understand the rate of sickness absence (SA) among employees of public healthcare organizations in Mongolia, to identify factors associated with long-term SA, and to estimate costs due to SA. METHODS: This cross-sectional study included employees of public healthcare organizations who had certified SA from 2016 to 2018. Sociodemographic and occupational characteristics of absentees and the data on absences were collected. A logistic regression analysis was performed to identify factors associated with long-term SA (≥15 days) among employees who had SA. Absence parameters and the average costs due to SA were calculated and the total cost due to SA at all public healthcare organizations was estimated. RESULTS: From 2016 to 2018, there were 13 653 absentees and 21 043 SA, and the absence rate was 0.9%. The average absence length per absence and absentee were 9.63 days and 14.85 days, respectively. Factors associated with long-term SA were age ≥40 years, 10-19 years in employment, working at the second and tertiary levels, and night shift. The average cost per absentee was 295.5 USD, and the estimated total cost for all health organizations was 1 796 993 USD per year. CONCLUSIONS: The absence rate was 0.9% and older age, longer work experience, higher organizational level, and night shift were associated with taking a long-term SA. To reduce the costs of absenteeism and promote the health of employees in healthcare organizations, policymakers should review the policies related to SA and develop national guidelines on SA for employers, healthcare managers, and employees.

Detection and antibiotic resistance of diarrheagenic Escherichia coli from patients with diarrhea in Ulaanbaatar, Mongolia.

INTRODUCTION: Diarrheal diseases are common with worldwide distribution, and diarrheagenic Escherichia coli (DEC) strains are the main causative agents. The present study aimed to define the association of various pathotypes of E. coli from diarrheal patients in Mongolia. METHODOLOGY: A total of 341 E. coli strains were isolated from the stool of diarrheal patients. Bacterial susceptibility to antimicrobial agents was determined by the Kirby Bauer disk diffusion method. DEC isolates were identified by HEp-2 cell adherence assay and multiplex polymerase chain reaction (PCR). RESULTS: DEC pathogens were detected in 53.7% of 341 E. coli isolates. Enteroaggregative E. coli (EAEC) was the most common DEC pathotype identified by HEp-2 adherence assay and multiplex PCR methods in 97 samples (28.4%), followed by atypical enteropathogenic E. coli (EPEC) in 50 samples (14.7%), diffusely adherent E. coli (DAEC) in 25 samples (7.3%), enterohaemorrhagic E. coli (EHEC) in 6 samples (1.8%), enterotoxigenic E. coli (ETEC) in 4 samples (1.2%), and enteroinvasive E. coli (EIEC) in 1 sample (0.3%). DEC strains had > 50% antibiotic resistance against cephalothin, ampicillin, and trimethoprim/sulfamethoxazole. All tested DEC strains were susceptible to imipenem. Among the 183 DEC strains, 27 (14.8%) were extended spectrum beta-lactamase producing isolates, and 125 (68.3%) isolates were multiple drug resistant. CONCLUSIONS: We have identified six pathotypes of DEC from the clinical isolates tested and concluded that a high prevalence of antimicrobial resistance was observed in these pathotypes. EAEC was the most common pathotype identified and this is the first report of EHEC identification in Mongolia.

Comparison of Three Diagnostic Definitions of Metabolic Syndrome and Estimation of Its Prevalence in Mongolia.

We sought to estimate the prevalence of metabolic syndrome (MS) in the urban population of Mongolia and suggest a preferred definition. This cross-sectional study comprised 2076 representative samples, which were randomly selected to provide blood samples. MS was defined by the National Cholesterol Education Program's Adults Treatment Panel III (NCEP ATP III), the International Diabetes Federation (IDF), and the Joint Interim Statement (JIS). The Cohen's kappa coefficient (κ) was analyzed to determine the agreement between the individual MS components using the three definitions. The prevalence of MS in the 2076 samples was 19.4% by NCEP ATP III, 23.6% by IDF, and 25.4% by JIS criteria. For men, moderate agreement was found between the NCEP ATP III and waist circumference (WC) (κ = 0.42), and between the JIS and fasting blood glucose (FBG) (κ = 0.44) and triglycerides (TG) (κ = 0.46). For women, moderate agreement was found between the NCEP ATP III and high-density lipoprotein cholesterol (HDL-C) (κ = 0.43), and between the JIS and HDL-C (κ = 0.43). MS is highly prevalent in the Mongolian urban population. The JIS definition is recommended as the provisional definition.

Insights into the Molecular Epidemiology of Foot-and-Mouth Disease Virus in Russia, Kazakhstan, and Mongolia in Terms of O/ME-SA/Ind-2001e Sublineage Expansion.

Foot-and-mouth disease (FMD) has long been recognized as a highly contagious, transboundary disease of livestock incurring substantial losses and burdens to animal production and trade across Africa, the Middle East, and Asia. Due to the recent emergence of the O/ME-SA/Ind-2001 lineage globally contributing to the expansion of FMD, molecular epidemiological investigations help in tracing the evolution of foot-and-mouth disease virus (FMDV) across endemic and newly affected regions. In this work, our phylogenetic analysis reveals that the recent FMDV incursions in Russia, Mongolia, and Kazakhstan in 2021-2022 were due to the virus belonging to the O/ME-SA/Ind-2001e sublineage, belonging to the cluster from Cambodian FMDV isolates. The studied isolates varied by 1.0-4.0% at the VP1 nucleotide level. Vaccine matching tests indicated that the vaccination policy in the subregion should be tailored according to the peculiarities of the ongoing epidemiologic situation. The current vaccination should change from such vaccine strains as O1 Manisa (ME-SA), O no 2102/Zabaikalsky/2010 (O/ME-SA/Mya-98) (r1 = 0.05-0.28) to strains that most closely antigenically match the dominant lineage O No. 2212/Primorsky/2014 (O O/ME-SA//Mya-98) and O No. 2311/Zabaikalsky/2016 (O ME-SA/Ind-2001) (r1 = 0.66-1.0).

Genomic analysis of Leishmania turanica strains from different regions of Central Asia.

The evolution in Leishmania is governed by the opposite forces of clonality and sexual reproduction, with vicariance being an important factor. As such, Leishmania spp. populations may be monospecific or mixed. Leishmania turanica in Central Asia is a good model to compare these two types. In most areas, populations of L. turanica are mixed with L. gerbilli and L. major. Notably, co-infection with L. turanica in great gerbils helps L. major to withstand a break in the transmission cycle. Conversely, the populations of L. turanica in Mongolia are monospecific and geographically isolated. In this work, we compare genomes of several well-characterized strains of L. turanica originated from monospecific and mixed populations in Central Asia in order to shed light on genetic factors, which may drive evolution of these parasites in different settings. Our results illustrate that evolutionary differences between mixed and monospecific populations of L. turanica are not dramatic. On the level of large-scale genomic rearrangements, we confirmed that different genomic loci and different types of rearrangements may differentiate strains originated from mixed and monospecific populations, with genome translocations being the most prominent example. Our data suggests that L. turanica has a significantly higher level of chromosomal copy number variation between the strains compared to its sister species L. major with only one supernumerary chromosome. This suggests that L. turanica (in contrast to L. major) is in the active phase of evolutionary adaptation.

Stigma, Post-traumatic Stress, and COVID-19 Vaccination Intent in Mongolia, India, and the United States.

Background: Stigma and discrimination during the coronavirus (COVID-19) pandemic have increased precipitously worldwide. This multinational study examines how stigma, blaming groups for virus spread, concern regarding contracting the virus, resource loss, life satisfaction, and protective behaviors that help control the spread of COVID-19 are associated with post-traumatic stress and vaccine intent in Mongolia, India, and the United States. Method: 1429 people in Mongolia, India, and the United States completed measures assessing stigma during the COVID-19 pandemic, post-traumatic stress, blame, protective behaviors, and vaccine intent. Results: Mean post-traumatic stress scores in all three countries exceeded the cut-off that is commonly used to determine probable post-traumatic stress. Post-traumatic stress was associated with COVID-19 stigma experience, personal behavior change due to COVID-19 stigma, blaming groups for the spread of COVID-19, fear of COVID-19, and resource loss. In India and the United States, personal behavior change due to COVID-19 stigma, anger at individuals spreading COVID-19, and perceived susceptibility to illness were positively associated with vaccine intent. Conclusions: Stigma is a collateral stressor during the pandemic. The findings underscore the importance of prompt action to address stigma as a deleterious consequence of the pandemic. The findings illuminate potential barriers to receiving the vaccine and provide direction for future research to address barriers.

Pattern changes of ecological product trade in countries along the Belt and Road.

The Belt and Road Initiative (BRI) was designed to promote economic and trade cooperation between countries along the Belt and Road (B&R), specifically by building an international trade network. Ecological resources are the basis for human survival. Countries along the B&R transform ecological resources into ecological products by production activities. These products can then be used for trade, thereby driving the countries' economic development. This study uses net primary productivity (NPP) as a unified measure of ecological products, and explores the pattern changes of ecological product trade in countries along the B&R, from 2013 to 2019 (from the BRI proposal to the outbreak of COVID-19). The purpose of the study is to reveal the impact of the BRI on the trade of ecological products. The results show that (1) the trade scale of ecological products in the B&R region has changed significantly. The total volume of traded ecological products increased from 2071.74 to 2631.00 TgC. This represented an increase of about 26.99%, or 7.41% higher than the global average. (2) The spatial distribution pattern of ecological product trade did not change significantly in countries along the B&R. However, the gravity centers of the total and net trade volume of ecological products moved 120.74 km to the northeast and 392.98 km to the southeast, respectively. (3) The trade structure of ecological products in the B&R region, six sub-regions, and most countries remained relatively stable. Only the proportion of the livestock products trade in Mongolia and the proportion of the forest products trade in Bhutan have increased significantly. This finding suggests that the strength and breadth of the construction of unimpeded trade in countries along the B&R still need to further strengthened, in order to accelerate the realization of the vision of the Green Silk Road.

Assessing the impact of sand and dust storm on agriculture: Empirical evidence from Mongolia.

Assessing the economic impact of sand and dust storms provides critical insights to policy development and reforms; a subject that is gaining more attention as risk management becomes the dominant approach for hazard mitigation policies. To assess the causal impact of sand and dust storms on agriculture, specifically on crop and livestock revenue and physical production, random year-to-year variations in dust exposure were analyzed using a fixed effect regression. To complete this analysis, weather and climate data from the on-ground meteorological stations was combined with the household level socioeconomic surveys conducted by Mongolia's National Statistics Office (NSO) over a decade. The descriptive statistics of the meteorological data collected over the eight years period show that, on average, 29 dust events have occurred every year across the country, with greater variation among provinces (Aimags) and regions, reaching up to 108 events in a year in some provinces. The overall trend reveals a slight decrease in the dust events from 2009 to 2019. The econometric results show that value of crop and livestock production (gross income) and physical yields significantly decline in response to higher frequencies of sand and dust storms events. During this period, Mongolia experienced a 2.7% decline in crop revenue as a result of additional sand and dust storms. Assuming 2.7% constant decline in revenues across all agricultural sub-sectors and regions or Aimags, this could lead to about $37.8 million in losses to the economy, which is equivalent to about 0.27% of the national GDP of Mongolia. Increases in the frequency of sand and dust storms could reduce agricultural productivity by between 1.5% to 24%, depending on the crop. Estimates from the modelling exercise are robust to potential endogeneity bias in the measure of sand and dust storms; different specification and identification approaches accounting for the endogeneity bias consistently reveal negative and qualitatively similar impacts of sand and dust storms on crop and livestock productivity.

Sociodemographic predictors of flourishing among older adults in rural and urban Mongolia.

Flourishing is an eudaimonic dimension of psychological well-being associated with positive social and health outcomes. Determining correlates of health and well-being is critical for the development of evidence-based best practices, policies, and action plans that target older adults, especially in low- and middle-income countries where research on ageing, health and well-being is still scarce. The study aimed to determine the level of flourishing among older adults in Mongolia and to explore demographic and social factors that contribute to their flourishing in urban and rural areas of Mongolia. We used proportional quota sampling to select a non-probability sample of 304 community-dwelling older adults that reflected the national distribution of older age groups and rural/urban residency. We adapted and administered a widely used standardized questionnaire on flourishing and used multiple regression to establish correlates of flourishing. Study participants reported "very high" levels of flourishing; differences in median scores 53 for urban and 50 for rural older adults were significant. Sex ([Formula: see text], [Formula: see text]), level of education([Formula: see text], [Formula: see text]) and receive help with ADLs ([Formula: see text], [Formula: see text]) were associated with flourishing in rural areas, as were self-rated health ([Formula: see text], [Formula: see text]), number of social activities ([Formula: see text], [Formula: see text]),and friends network ([Formula: see text], [Formula: see text]) in urban areas. Despite facing many challenges to well-being, older adults in Mongolia reported high levels of flourishing. Those in urban areas had higher scores than those in rural areas and predictors of flourishing differed for these groups.

Impacts of climate and tree morphology on tree-ring stable isotopes in central Mongolia.

Recent climate extremes in Mongolia have ignited a renewed interest in understanding past climate variability over centennial and longer time scales across north-central Asia. Tree-ring width records have been extensively studied in Mongolia as proxies for climate reconstruction, however, the climate and environmental signals of tree-ring stable isotopes from this region need to be further explored. Here, we evaluated a 182-year record of tree-ring δ13C and δ18O from Siberian Pine (Pinus sibirica Du Tour) from a xeric site in central Mongolia (Khorgo Lava) to elucidate the environmental factors modulating these parameters. First, we analyzed the climate sensitivity of tree-ring δ13C and δ18O at Khorgo Lava for comparison with ring-width records, which have been instrumental in reconstructing hydroclimate in central Mongolia over two millennia. We also compared stable isotope records of trees with partial cambial dieback ('strip-bark morphology'), a feature of long-lived conifers growing on resource-limited sites, and trees with a full cambium ('whole-bark morphology'), to assess the inferred leaf-level physiological behavior of these trees. We found that interannual variability in tree-ring δ13C and δ18O reflected summer hydroclimatic variability, and captured recent, extreme drought conditions, thereby complementing ring-width records. The tree-ring δ18O records also had a spring temperature signal and thus expanded the window of climate information recorded by these trees. Over longer time scales, strip-bark trees had an increasing trend in ring-widths, δ13C (and intrinsic water-use efficiency, iWUE) and δ18O, relative to whole-bark trees. Our results suggest that increases in iWUE at this site might be related to a combination of leaf-level physiological responses to increasing atmospheric CO2, recent drought, and stem morphological changes. Our study underscores the potential of stable isotopes for broadening our understanding of past climate in north-central Asia. However, further studies are needed to understand how stem morphological changes might impact stable isotopic trends.

Effects of novel variants in BMP15 gene on litter size in Mongolia and Ujimqin sheep breeds.

Reproductive traits, such as ovulation rate and litter size, are important factors influencing the sheep industry. The bone morphogenetic protein 15 (BMP15) is a major gene affecting the reproductive traits in sheep, and multiple mutations in BMP15 gene could affect the ovulation rate and litter size in many sheep breeds, showing high breed specificity. However, identification of novel variations and seeking breed-specific markers associated with litter size in other sheep breeds are still important. In this study, we sequenced the BMP15 gene of Mongolia sheep, and 12 novel variants were detected by direct sequencing and whole-genome resequencing. Among them, the g.50985975 G > A polymorphism in intron and synonymous c.755 T > C (Leu252Pro) in exon 2 of BMP15 were significantly associated with the litter sizes of Mongolia ewes (P < 0.01 and P < 0.01, respectively), as well as the g.50988478C > A and g.50987863G > A in the promoter region of BMP15 were significantly associated with the litter sizes of Ujimqin ewes (P < 0.05 and P < 0.01, respectively). The c.755 T > C mutation is predicted to change the tertiary structure of BMP15. Our findings may provide potentially useful genetic markers for increasing litter size in sheep.