Apology for the publication of Sheng et al. (2024).

Recently, Cultural Diversity & Ethnic Minority Psychology (CDEMP) published Sheng et al.'s (see record 2024-72017-001) article titled "The Development of Tibetan Children's Racial Bias in Empathy: The Mediating Role of Ethnic Identity and Wrongfulness of Ethnic Intergroup Bias." The article went through the standard peer review process. Subsequent to its publication, one of our readers expressed concerns regarding the biased language (e.g., "backwardness of education") and deficit-oriented interpretation of findings (e.g., "the geographical environment and traditional way of life in Tibet can also impact the development of [racial biases in empathy] in Tibetan children"). The reader rightly pointed out that this language and interpretation reinforce imperialism, particularly given the complex relations between Tibet and China. We sincerely apologize to our readers, and especially to our Tibetan colleagues, for failing to identify these issues prior to the publication of the article.Wetake accountability for the oversight and have followed due process to correct our mistakes in the publication of this article. We will also take action to prevent this from happening again. In this editorial, we describe the study, actions taken by the CDEMP Editorial Team, the authors' response, and future actions to be taken by the CDEMP Editorial Team. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Impact of Tibetan ethnicity and residence altitude on complications during total knee arthroplasty and difficulties of measurement of perioperative blood loss.

PURPOSE: Tibetan patients undergoing total knee arthroplasty (TKA) have greater fluctuations in perioperative haemoglobin levels and blood hypercoagulability. This study was to investigate whether ethnicity and altitude affect perioperative blood loss and the risk of complications after TKA. METHODS: We retrospectively enrolled 1,116 patients undergoing TKA for knee osteoarthritis at our hospital between January 2016 and September 2021. We divided patients into four groups according to whether they were of Tibetan or Han ethnicity and whether they lived above or below 2500 m above sea level. Primary outcomes were total, intraoperative, and hidden blood losses, while secondary outcomes were complications and homologous transfusion. Factors associated with increased blood loss were analyzed by multivariate regression. RESULTS: Total blood loss was higher among patients residing at high altitude compared with lower altitude, whether they were of Han (794.6 mL vs. 667.2 mL, P = 0.020) or Tibetan (904.4 mL vs. 663.8 mL, P < 0.001). Total blood loss was similar between the two ethnic groups at the same altitude. Altitude, but not Tibetan ethnicity, remained associated with increased blood loss after being analyzed by multivariate regression. Complications among the four groups were generally similar, although the frequency of calf muscular venous thrombosis was higher among Tibetan patients, while the frequency of blood transfusion was higher among Han subjects. CONCLUSIONS: Our findings indicate that residence at high altitude, but not ethnicity, may contribute to increased total blood loss during TKA. Thrombotic complications were more frequent among Tibetan than Han patients.

Comparison of physical activity and physical fitness in children and adolescents of Chinese Han and Tibet ethnicity.

Background: Physical activity (PA) and physical fitness (PF) are important markers of health status in children and adolescents in different ethnicities. In this study, we aimed to compare the PA and PF indicators between Tibetan and Han children and adolescents. Methods: Children and adolescents of 4-9 grades were recruited in Shigatse (n = 963) and Shanghai (n = 2,525) respectively. The information related to demographic, PA, and PF was collected via a self-reported questionnaire. PA was assessed through the participation of moderate to vigorous PA (MVPA), muscle-strengthening exercise (MSE) and organized sport participation (OSP). PF was estimated using the International Fitness Scale containing components of overall fitness, cardiorespiratory fitness, speed and agility, muscular strength and flexibility. Results: Han (mean age = 13.45 ± 3.3 years; 49.7% girls) and Tibet (mean age = 13.8 ± 2.5 years; 48.3% girls) children and adolescents from Shanghai and Shigatse completed the questionnaire survey. It was revealed that Tibetan students had higher MVPA, MSE and OSP than children and adolescents of Han ethnicity (p < 0.01, small to medium effect size). A relatively higher percentage of student in Shanghai did not participate in any form of PA. On the other hand, less Tibetan students thought their PF indicators including overall fitness, cardiorespiratory fitness, speed and agility, muscular strength and flexibility were poor or very poor than their counterparts of Han ethnicity (p < 0.01, small to medium effect size). Conclusion: Tibetan children and adolescents have higher levels of PA and PF in comparison to their Han counterparts. More children and adolescents of Han ethnicity engage in no PA and think their PF indicators were poor.

Comparative analysis of the clinical features of nonvalvular atrial fibrillation among Tibetan, Han, and Hui patients in Qinghai Province, China.

BACKGROUND: Global nonvalvular AF rises, impacting health severely. In Qinghai, China's diverse setting, studying AF among varied ethnic groups is crucial OBJECTIVES: The purpose of this study was to compares cardiac features in AF among Tibetan, Han, and Hui patients to develop tailored prevention and treatment strategies for this region, the goal was to enhance the understanding of AF and provide an empirical basis for developing prevention and treatment strategies specific to this region METHODS: This study included a total of 3445 Tibetan, Han, and Hui patients diagnosed with nonvalvular atrial fibrillation and treated at the Qinghai Cardiovascular and Cerebrovascular Specialist Hospital, China, between January 2019 and January 2021. We analyzed the differences in cardiac structure, comorbidities, and other influencing factors among the different ethnic groups RESULTS: We found significant differences in gender, age, smoking history, lone atrial fibrillation, left heart failure, dilated cardiomyopathy, and diabetes between Tibetan, Han, and Hui patients (P < 0.05). Tibetan, Han, and Hui patients also differed with regard to left ventricular end-diastolic volume, left ventricular ejection fraction, fractional shortening, NT-proBNP, glycated hemoglobin, red blood cell distribution width, platelet count, platelet hematocrit, platelet distribution width, homocysteine (Hcy), C-reactive protein, and superoxide dismutase (SOD) (P < 0.05) CONCLUSION: Our study revealed variations in comorbidities, cardiac structure, and blood indexes among Tibetan, Han, and Hui AF patients, highlighting distinct patterns in complications and biomarker levels across ethnic groups.

Transcultural Adaptation of Tibetan Nursing Trainees: A Case Study of "9+3" Vocational Technical Students in Sichuan Province, China.

BACKGROUND Nursing education is an important part of the "9+3" vocational education program led by Sichuan Province. In the internship stage, nursing students of Tibetan ethnicity may have problems of intercultural adaptation in the process of getting along with patients, which may affect the effective nursing outcome. The purpose of this study was to clarify the current situation of transcultural adaptation of Tibetan trainee nurses and to provide more theoretical support and guidance. MATERIAL AND METHODS We collected 237 valid survey questionnaires, based on Ward's acculturation process model, from a total of 363 Tibetan trainee nurses in the "9+3" free vocational education program in Chengdu, Luzhou, and Nanchong of Sichuan Province. The SPSSAU project (2020), an online application software retrieved from https://www.spssau.com, was used for data coding and archiving. RESULTS The results of questionnaire and data analysis showed that the overall level of transcultural adaptation of Tibetan trainee nurses was that the number of people with poor adaptation was slightly higher than those with good adaptation, and most Tibetan trainee nurses were in the middle level. Meanwhile, sociocultural adaptation was better than psychological adaptation. There were no statistically significant differences among the 4 grouping variables: gender, student home region, the city where the internship hospital was located, and whether they were from a single-child family or not. CONCLUSIONS The results revealed that there was still transcultural maladjustment among Tibetan nurses in the internship stage, and the psychological maladjustment was more obvious than the sociocultural maladjustment. We provide countermeasures and suggestions to solve the problems of transcultural adaptation reflected in the research.

Tibetan Y-STR trait in the eleven regions of the Qinghai-Tibet Plateau.

Y-Chromosomal short-tandem repeats (Y-STRs) could provide highly valuable information for forensic investigation and demographic studies. However, there is still no systematic Y-STR information on Tibetan as obtained from different regions of the broad Qinghai-Tibet Plateau. In this study, an analysis was conducted on 585 male individuals, classed into 3 different dialect branches as Ü-Tsang, Amdo, and Khams and originating from 11 scattered regions of the Qinghai-Tibet Plateau. The gene diversity values of the 41 Y-STRs in Tibetan ranged from 0.3636 to 0.9322. Additionally, a total of 563 distinct haplotypes were obtained with an overall haplotype diversity of 0.9999 and a discrimination capacity of 0.9624. As suggested by the inter-population diversity analysis, there were two main separated clades of Tibetan subgroups. The visualization of pairwise genetic distances between 11 Tibetan subgroups and 59 reference populations using cladogram revealed the distribution of various populations, which was basically consistent with the patterns of geographic origin and linguistic affinity.

Risk of developing active tuberculosis following tuberculosis screening and preventive therapy for Tibetan refugee children and adolescents in India: An impact assessment.

BACKGROUND: Tuberculosis (TB) rates among Tibetan refugee children and adolescents attending boarding schools in India are extremely high. We undertook a comprehensive case finding and TB preventive treatment (TPT) program in 7 schools in the Zero TB Kids project. We aimed to measure the TB infection and disease burden and investigate the risk of TB disease in children and adults who did and did not receive TPT in the schools. METHODS AND FINDINGS: A mobile team annually screened children and staff for TB at the 7 boarding schools in Himachal Pradesh, India, using symptom criteria, radiography, molecular diagnostics, and tuberculin skin tests. TB infection (TBI) was treated with short-course regimens of isoniazid and rifampin or rifampin. TB disease was treated according to Tibetan and Indian guidelines. Between April 2017 and December 2019, 6,582 schoolchildren (median age 14 [IQR 11-16] years) and 807 staff (median age 40 [IQR 33-48] years) were enrolled. Fifty-one percent of the students and 58% of the staff were females. Over 13,161 person-years of follow-up in schoolchildren (median follow-up 2.3 years) and 1,800 person-years of follow-up in staff (median follow-up 2.5 years), 69 TB episodes occurred in schoolchildren and 4 TB episodes occurred in staff, yielding annual incidence rates of 524/100,000 (95% CI 414-663/100,000) person-years and 256/100,000 (95% CI 96-683/100,000) person-years, respectively. Of 1,412 schoolchildren diagnosed with TBI, 1,192 received TPT. Schoolchildren who received TPT had 79% lower risk of TB disease (adjusted hazard ratio [aHR] 0.21; 95% CI 0.07-0.69; p = 0.010) compared to non-recipients, the primary study outcome. Protection was greater in recent contacts (aHR 0.07; 95% CI 0.01-0.42; p = 0.004), the secondary study outcome. The prevalence of recent contacts was 28% (1,843/6,582). Two different TPT regimens were used (3HR and 4R), and both were apparently effective. No staff receiving TPT developed TB. Overall, between 2017 and 2019, TB disease incidence decreased by 87%, from 837/100,000 (95% CI 604-1,129/100,000) person-years to 110/100,000 (95% CI 36-255/100,000) person-years (p < 0.001), and TBI prevalence decreased by 42% from 19% (95% CI 18%-20%) to 11% (95% CI 10%-12%) (p < 0.001). A limitation of our study is that TB incidence could be influenced by secular trends during the study period. CONCLUSIONS: In this study, following implementation of a school-wide TB screening and preventive treatment program, we observed a significant reduction in the burden of TB disease and TBI in children and adolescents. The benefit of TPT was particularly marked for recent TB contacts. This initiative may serve as a model for TB detection and prevention in children and adolescents in other communities affected by TB.

Association between ALOX15 gene polymorphism and brick-tea type skeletal fluorosis in Tibetans, Kazaks and Han, China.

To evaluate the association between ALOX15 gene polymorphism and skeletal fluorosis (SF), a case-control study was conducted. A total of 1023 individuals, including 308 Tibetans, 290 Kazaks and 425 Han, were enrolled in this study, in which cases and controls were 278 and 745, respectively. SF was diagnosed by X-ray absorptiometry. SNPs were genotyped using the Sequenom Mass ARRAY system. The genotypes of ALOX15 rs7220870, rs2664593 and rs1107852 were not associated with the risk of SF. After reconstructing the haplotype of rs7220870 and rs11078528, the risk effect of haplotype CA was found in Han participants aged ≤45 years or with moderate fluoride intake. Diplotype of CC/CC had a protective effect on SF risk in Han participants; whereas, CA/CC diplotype showed a risk effect on SF risk in participants aged ≥65; Our results provide the first evidence of an association between ALOX15 gene polymorphism and SF risk in Han participants.Abbreviation: SF: Skeletal fluorosis; SNP: Single Nucleotide polymorphism.

Tracing the Genetic Legacy of the Tibetan Empire in the Balti.

The rise and expansion of Tibetan Empire in the 7th to 9th centuries AD affected the course of history across East Eurasia, but the genetic impact of Tibetans on surrounding populations remains undefined. We sequenced 60 genomes for four populations from Pakistan and Tajikistan to explore their demographic history. We showed that the genomes of Balti people from Baltistan comprised 22.6-26% Tibetan ancestry. We inferred a single admixture event and dated it to about 39-21 generations ago, a period that postdated the conquest of Baltistan by the ancient Tibetan Empire. The analyses of mitochondrial DNA, Y, and X chromosome data indicated that both ancient Tibetan males and females were involved in the male-biased dispersal. Given the fact that the Balti people adopted Tibetan language and culture in history, our study suggested the impact of Tibetan Empire on Baltistan involved dominant cultural and minor demic diffusion.

Prevalence of Amblyopia and Associated Risk Factors in Tibetan Grade One Children.

INTRODUCTION: Amblyopia is an important public health problem and standard screening is quite necessary for early diagnosis and treatment especially for the remote areas. As the place of the largest Tibetan population, the Tibetan Plateau has special geographical characteristics such as high altitude, time zone, and ethnic composition, where very little information is available about the prevalence of amblyopia and other ocular diseases. The article aims to determine the prevalence of amblyopia and associated factors in grade 1 Tibetan children, living in Lhasa, Tibet Autonomous Region. METHODS: A cross-sectional study was conducted. All the participants were scheduled for comprehensive eye examinations including visual acuity testing, ocular deviation and movement evaluation, cycloplegic refraction and examinations of the external eye, anterior segment, media, and fundus. Amblyopia was assessed in the children according to the standard definition. RESULTS: A total of 1,856 students participated in the examinations (97.58% response rate). 1,852 students completed all the related examinations, and 34 of them were diagnosed as amblyopia with the prevalence of 1.84% (95% confidence interval [CI]: 1.22-2.45%). Unilateral amblyopia was diagnosed in 23 students (1.24%, 95% CI: 0.74-1.75%), including 16 anisometropic, 4 strabismic, 1 visual deprivational, and 2 mixed. Other 11 students were diagnosed as bilateral amblyopia (0.59%, 95% CI: 0.24-0.94%), including 9 ametropic, 1 deprivational, and 1 with nystagmus. The mean cylinder refraction and absolute value of the spherical equivalent refraction of amblyopic eyes was respectively -2.15 ± 1.52 D and 2.70 ± 2.33 D. Amblyopia was significantly associated with hyperopia (≥+2.00 D, odds ratio [OR] 8.22, 95% CI 3.42-19.72), astigmatism (≤-2.00 D, OR 6.76, 95% CI 2.56-17.85), and anisometropia (≥+0.50 to <+1.00 D, OR 3.95, 95% CI 1.44-10.79; ≥+1.00 D, OR 21.90, 95% CI 8.24-58.18). CONCLUSIONS: The prevalence of amblyopia in grade 1 students of Lhasa is relatively higher than that of many other ethnic populations in China previously reported. Refractive errors including anisometropia, hyperopia, and astigmatism are the major risk factors of amblyopia.

Forensic and phylogenetic analyses of populations in the Tibetan-Yi corridor using 41 Y-STRs.

Y-chromosome haplotypes of 527 non-related males (176 Han, 186 Tibetan, and 165 Yi) in the Tibetan-Yi corridor were analyzed using SureID® PathFinder Plus. In the populations of Han, Tibetans, and Yi, the haplotype diversity was 0.9989, 0.9981, and 0.9993, respectively, and the discrimination capacity was 0.9148, 0.8925, and 0.9576, respectively. Phylogenetic relationships among 12 studied ethnic groups and 7 other ethnic groups in the Tibetan-Yi corridor were investigated. Both multi-dimensional scaling analysis and phylogenetic reconstructions indicated that Tibetans appeared separated from the Han and Yi ethnic groups in the Tibetan-Yi corridor. Their genetic homogeneity or heterogeneity has not entirely been affected by their geographical distance and linguistic origin.

Chromatin accessibility landscape and regulatory network of high-altitude hypoxia adaptation.

High-altitude adaptation of Tibetans represents a remarkable case of natural selection during recent human evolution. Previous genome-wide scans found many non-coding variants under selection, suggesting a pressing need to understand the functional role of non-coding regulatory elements (REs). Here, we generate time courses of paired ATAC-seq and RNA-seq data on cultured HUVECs under hypoxic and normoxic conditions. We further develop a variant interpretation methodology (vPECA) to identify active selected REs (ASREs) and associated regulatory network. We discover three causal SNPs of EPAS1, the key adaptive gene for Tibetans. These SNPs decrease the accessibility of ASREs with weakened binding strength of relevant TFs, and cooperatively down-regulate EPAS1 expression. We further construct the downstream network of EPAS1, elucidating its roles in hypoxic response and angiogenesis. Collectively, we provide a systematic approach to interpret phenotype-associated noncoding variants in proper cell types and relevant dynamic conditions, to model their impact on gene regulation.

Trekking and toddlers: Towards a biocultural analysis of growth among infants and young children in a rural region of the Himalayas.

OBJECTIVES: Rapid socioeconomic change, associated with development and a growing tourism industry is occurring across the Himalayas. The health impact of this rapid economic development is poorly understood, especially for infants and young children. This study investigated the associations between village level economic differences as indexed by economic development and tourism engagement on infant and young child growth and health in a population of ethnic Tibetans living in the western Himalayas of Nepal. METHODS: One hundred and fifty nine infants and young children (ages 1-24 months) were enrolled. Anthropometric data (height, weight, triceps skinfold thickness) were collected at a single time point. Village level measurements of tourism and market engagement were incorporated into a scale measuring tourism, healthcare, trail access, agriculture, and involvement in medicinal trade. Village level disease patterns were calculated from morbidity and mortality recalls collected since 2003. RESULTS: There were no significant associations between infant weight for age z-score (WAZ), length for age z-score (LAZ), or weight-for-length for age z-score (WLZ) and village altitude, village economic development score, or engagement in tourism. Males had significantly higher LAZ, WAZ, and WLZ compared to females; only females showed a decline in LAZ with age. Triceps skinfold thickness z-score (ZTSF) was inversely associated with village level economic development score in male but not female infants; females ZTSF was positively associated with IYC age. CONCLUSIONS: While overall size for age indices (WAZ, LAZ, WLZ) were not associated with altitude or village economic development in this population, ZTSF was inversely associated with village economic development in males but not females.

Genetic diversity and phylogenetic analysis of 29 Y-STR loci in the Tibetan population from Sichuan Province, Southwest China.

Y-Chromosomal short tandem repeat polymorphisms (Y-STRs) are widely applied in human forensic cases and population genetic studies. There is a lack of information about the Sichuan Tibetan population in the Y-STR Haplotype Reference Database (YHRD, https://yhrd.org, release 59). In this study, 502 unrelated male individuals residing in the Sichuan Province were recruited and genotyped at 29 Y-STR loci. A total of 479 haplotypes were observed, 460 (96.03%) of which were unique. The haplotype diversity (HD) and discrimination capacity (DC) for the Sichuan Tibetan population were 0.9998 and 0.9542, respectively. To reveal the genetic diversities and relationships between the Chinese Sichuan Tibetan and 29 other previously reported populations, forensic parameter analysis, multi-dimensional scaling, and phylogenetic reconstruction were performed. The results showed that the Sichuan Tibetan population was relatively isolated from other populations, suggesting that genetic proximity is in line with geographical boundaries.

Development of a facial-expression database of Chinese Han, Hui and Tibetan people.

Recently, cross-cultural facial-expression recognition has become a research hotspot, and a standardised facial-expression material system can significantly help researchers compare and demonstrate the results of other studies. We developed a facial-expression database of Chinese Han, Hui and Tibetan ethnicities. In this study, six basic human facial expressions (and one neutral expression) were collected from 200 Han, 220 Hui and 210 Tibetan participants who lived in these regions. Four experts on each ethnicity evaluated the facial-expression images according to the expressions, and only those achieving inter-rater agreement were retained. Subsequently, 240 raters evaluated these images according to the seven emotions and rated the intensity of the expressions. Consequently, 2980 images were included in the database, including 930 images of Han individuals, 962 images of Hui individuals and 1088 images of Tibetan individuals. In conclusion, the facial-expression database of Chinese Han, Hui and Tibetan people was representative and reliable with a recognition rate of over 60%, making it well-suited for cross-cultural research on emotions.

Genetic and epigenetic polymorphisms of eNOS and CYP2D6 in mainland Chinese Tibetan, Mongolian, Uygur, and Han populations.

Cytochrome P450 2D6 (CYP2D6) and endothelial nitric oxide synthase (eNOS) are important in the cardiovascular disease susceptibility and drug response. The methylation of cytosine in the promoter of genes could influence expression. The interindividual differences of drug response could only be explained partly by the polymorphisms of drug disposition genes. This study was aimed to investigate the genetic and epigenetic polymorphisms of CYP2D6 and eNOS in Chinese Tibetan, Mongolian, Uygur, and Han volunteers. Blood samples were collected from 842 unrelated Chinese healthy subjects (323 Tibetan, 134 Mongolian, 162 Uygur, and 223 Han) for genotyping and part of the DNA samples were subjected to cytosine methylation analysis. Significant genetic and epigenetic interethnic polymorphisms of eNOS and CYP2D6 were found in the four Chinese groups. The 4b-G-T wild-type haplotype of eNOS was the most common in Chinese Tibetan (87.1%), Mongolian (79.9%), Uygur (76.4%), and Han (79.5%), respectively. eNOS T-786C creates a new CpG site and a significantly higher methylation level was found in -786CC than that in -786TC in Chinese Han (P = 0.0485) and total Chinese (P = 0.0104). CYP2D6 A-678 (rs28633410) makes the symmetrical CpG site changed to be an asymmetrical CpA site, and the methylation level of cytosine in the CpG context of G-678A was significantly higher than that in the CpA. The results of the present study could be useful for understanding the interindividual disparity of cardiovascular disease susceptibility and drug response among different Chinese ethnic groups and would provide more evidences for the precise medication of Chinese.

Prevalence difference of Helicobacter pylori infection between Tibetan and Han ethnics: The protocol of a meta-analysis on epidemiologic studies.

OBJECTIVES: Helicobacter pylori (Hp) is an identified carcinogenic pathogen of human gastric cancer. China is not only one of the countries with high incidence and mortality of gastric cancer, but also a high infection area of Hp. As a multi-ethnic country, China may have a diverse prevalence of Hp infection among ethnics. This meta-analysis tends to compare the prevalence of Hp infection between Tibetan and Han ethnics, the results may provide evidence for targeted screening and eradication of Hp in China. METHODS: The following databases will be searched: PubMed, Web of Science, Technology Periodical Database (VIP), China National Knowledge infrastructure (CNKI), and WanFang databases. Studies which reported the prevalence of Hp infection between Tibetans and Hans in China are eligible. Two reviewers will independently screen studies, extract data and assess the risk of bias of included studies. The prevalence of Hp infection between Tibetan and Han ethnics will be compared by meta-analysis. Heterogeneity tests and meta-analyses will be conducted using RevMan 5.3 and Stata 12.0 softwares. Meanwhile, subgroup analysis, publication bias and sensitivity analysis evaluation will be performed where applicable. RESULTS: This study will be reported in compliance with the PRISMA statement.This systematic review will not be submitted for any ethical approval since no privacy health information will be included. The findings will be published through peer-reviewed publications or conference presentations. PROSPERO REGISTRATION NUMBER: CRD42019121192. CONCLUSIONS: Our study will provide us evidence for tailored strategy and robustness of Hp screening and eradication among Tibetans.

Exhaled nitric oxide in ethnically diverse high-altitude native populations: A comparative study.

OBJECTIVES: Andean and Tibetan high-altitude natives exhibit a high concentration of nitric oxide (NO) in the lungs, suggesting that NO plays an adaptive role in offsetting hypobaric hypoxia. We examined the exhaled NO concentration as well as partial pressure of several additional high-altitude native populations in order to examine the possibility that this putative adaptive trait, that is, high exhaled NO, is universal. METHODS: We recruited two geographically diverse highland native populations, Tawang Monpa (TM), a Tibetan derived population in North-Eastern India (n = 95, sampled at an altitude of ~3,200 m), and Peruvian Quechua from the highland Andes (n = 412). The latter included three distinct subgroups defined as those residing at altitude (Q-HAR, n = 110, sampled at 4,338 m), those born and residing at sea-level (Q-BSL, n = 152), and those born at altitude but migrant to sea-level (Q-M, n = 150). In addition, we recruited a referent sample of lowland natives of European ancestry from Syracuse, New York. Fraction of exhaled NO concentrations were measured using a NIOX NIMO following the protocol of the manufacturer. RESULTS: Partial pressure of exhaled nitric oxide (PENO) was significantly lower (p < .05) in both high-altitude resident groups (TM = 6.2 ± 0.5 nmHg and Q-HAR = 5.8 ± 0.5 nmHg), as compared to the groups measured at sea level (USA = 14.6 ± 0.7 nmHg, Q-BSL = 18.9 ± 1.6 nmHg, and Q-M = 19.2 ± 1.7 nmHg). PENO was not significantly different between TM and Q-HAR (p < .05). CONCLUSION: In contrast to previous work, we found lower PENO in populations at altitude (compared to sea-level) and no difference in PENO between Tibetan and Andean highland native populations. These results do not support the hypothesis that high nitric oxide in human lungs is a universal adaptive mechanism of highland native populations to offset hypobaric hypoxia.

Genetic structure and forensic characteristics of Tibeto-Burman-speaking Ü-Tsang and Kham Tibetan Highlanders revealed by 27 Y-chromosomal STRs.

Culturally diverse Tibetans (Ü-Tsang, Kham and Ando) harboring a unique molecular mechanism that allows them to successfully adapt to hypoxic environments in the Qinghai-Tibet Plateau have been a subject of great interest in medical genetics, linguistics, archeology and forensic science. However, forensic characteristics and genetic variations of the Y-chromosomal 27-marker haplotype included in the Yfiler Plus system in the Ü-Tsang and Kham Tibeto-Burman-speaking Tibetans remain unexplored. Thus, we genotyped 27 Y-STRs in 230 Shigatse Ü-Tsang Tibetans (SUT) and 172 Chamdo Kham Tibetans (CKT) to investigate the forensic characterization and genetic affinity of Chinese Tibetan Highlanders. The haplotype diversities were 0.999962028 in SUT and 0.999796002 in CKT. Forensic diversity measures indicated that this 27-Y-STR amplification system is appropriate for routine forensic applications, such as identifying and separating unrelated males in deficiency paternity cases, male disaster victims and missing person identification and determining male components in sexual assault cases. Moreover, the genetic relationships among 63 worldwide populations (16,282 individuals), 16 Asian populations, and 21 Chinese populations were analyzed and reconstructed using principal component analysis, multidimensional scaling plots and a phylogenetic tree. Considerable genetic differences were observed between Tibetan populations and other geographically/ethnically diverse populations (Han Chinese). Our studied SUT and CKT have a genetically closer relationship with Gansu Ando Tibetans than with other Asians. In total, our analyses indicated that subpopulation structures exist among Asian and Chinese populations, and population-specific reference databases should be established for forensic applications.