High altitude

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The Hindu Kush high-altitude regions of Pakistan are currently experiencing severe consequences as a result of global warming. In this sense, increasing soil erosion and the quick melting of glaciers are two particularly evident effects. In such a scenario, understanding long-term temperature changes is crucial for making accurate forecasts about how the Hindu Kush region may experience regional temperature changes in the future. In this study, the climate tree-ring width (TRW) analysis designated a positive and significant correlation (r = 0...

OBJECTIVE: To evaluate silica exposure among Chilean miners at high altitude, using different methodological approaches, for the purpose of determining the safest method to control exposures.  Methods: The 46 miners in the sample worked at 3000 meters above sea level in nonstandard work shifts, consisting of four consecutive 12-hour days, followed by four consecutive days off. Silica samples were obtained in each of the jobs positions of these 46 high-altitude miners. The results of the concentrations are presented in mg/m3...

BACKGROUND: Previous studies showed that residents of higher elevations have lower glucose levels. Our objective in this study is to determine the basal and postprandial glucose levels in apparently healthy permanent residents of the miner population center of La Rinconada located 5100 meters (m) above sea level. METHOD: Forty male permanent residents of the Rinconada miner population center were studied. The oral glucose tolerance test was used to evaluate basal and postprandial glycemia levels at 1, 2, and 3 h...

BACKGROUND: During the last two decades, Caesarean section rates (C-sections), overweight and obesity rates increased in rural Peru. We examined the association between pre-pregnancy body mass index (BMI) and C-section in the province of San Marcos, Northern Andes-Peru. METHODS: This is a prospective cohort study. Participants were women receiving antenatal care in public health establishments from February 2020 to January 2022, who were recruited and interviewed during pregnancy or shortly after childbirth...

Adaptation of humans to challenging environmental conditions, such as extreme temperature, malnutrition, or hypoxia, is an interesting phenomenon for both basic and applied research. Identification of the genetic factors contributing to human adaptation to these conditions enhances our understanding of the underlying molecular and physiological mechanisms. In our study, we analyzed the exomes of 22 high altitude mountaineers to uncover genetic variants contributing to hypoxic adaptation. To our surprise, we identified two putative loss-of-function variants, rs1385101139 in RTEL1 and rs1002726737 in COL6A1 in two extremely high altitude (personal record of more than 8500 m) professional climbers...

BACKGROUND: Uncomplicated rhegmatogenous retinal detachment (RRD) is mainly treated with vitrectomy and gas tamponade or, alternatively, scleral buckling surgery. However, gas tamponade inflates at high altitudes, causing significant complications. Silicone oil (SO) tamponade volume is unaffected by atmospheric pressure and may be used in patients who live or must undertake travel at high altitudes. PURPOSE: To determine the anatomical and functional outcomes after pars plana vitrectomy (PPV) with SO tamponade in primary uncomplicated RRD...

Temperature is one of the most important factors in the life histories of ectotherms, as body temperature has an undeniable effect on growth, activity, and reproduction. Lizards have a wide variety of strategies to acquire and maintain body temperature in an optimal range. The "Thermal Melanism Hypothesis" proposes that individuals with lower skin reflectance can heat up faster as a result of absorbing more solar radiation compared to lighter conspecifics. Therefore, having a darker coloration might be advantageous in cold habitats...

BACKGROUND: The illnesses associated with changes in barometric pressure can be classified into three types: acute mountain sickness, high-altitude pulmonary edema (HAPE), and high-altitude cerebral edema. HAPE is a rare form of pulmonary edema that occurs in susceptible individuals after arriving at altitudes over 2500 m above sea level (m). Only a few studies have reported classical HAPE among children with underlying cardiopulmonary comorbidities. In this study, we report two pediatric cases of classical HAPE that occurred immediately upon arriving at Abha city (with an average elevation of 2270 m above sea level)...

BACKGROUND: Gas expansion in body cavities due to pressure changes at high altitudes can cause barodontalgia. This condition may compromise flight safety. AIM: To investigate relationships among barodontalgia awareness, dental visit frequency, and barodontalgia prevalence in civilian and military pilots operating at high altitudes. MATERIALS AND METHODS: Civilian pilots from Turkish Airlines and military pilots from the Turkish Air Force, flying between November 2022 and January 2023, participated in this study...

It is a great challenge to restore northern mines after mining and achieve optimal results due to the extremely harsh environment and climate, as in Qinghe County of Xinjiang Province, China. Qinghe County has a climate of drought, cold, strong winds, and high altitude. After sand and iron mining, the soil in this area contains a large amount of sand and gravel with extremely low organic matter, nitrogen deficiency, and a high pH of 9.26. Our preliminary studies disclosed that only three plants, including Caligonum junceum, Atraphaxis virgata, and Melilotus albus Medic, can grow naturally in this environment without any artificial management...

Hypobaric hypoxia, commonly experienced at elevated altitudes, presents significant physiological challenges. Our investigation is centered on the impact of the bromodomain protein 4 (BRD4) under these conditions, especially its interaction with the Wnt/β-Catenin pathway and resultant effects on glycolytic inflammation and intestinal barrier stability. By combining transcriptome sequencing with bioinformatics, we identified BRD4's key role in hypoxia-related intestinal anomalies. Clinical parameters of altitude sickness patients, including serum BRD4 levels, inflammatory markers, and barrier integrity metrics, were scrutinized...

Long-distance migrations of insects contribute to ecosystem functioning but also have important economic impacts when the migrants are pests or provide ecosystem services. We combined radar monitoring, aerial sampling, and searchlight trapping, to quantify the annual pattern of nocturnal insect migration above the densely populated agricultural lands of East China. A total of ~9.3 trillion nocturnal insect migrants (15,000 t of biomass), predominantly Lepidoptera, Hemiptera, and Diptera, including many crop pests and disease vectors, fly at heights up to 1 km above this 600 km-wide region every year...

Li, Xiaoxu, Zhijun Pu, Gang Xu, Yidong Yang, Yu Cui, Xiaoying Zhou, Chenyuan Wang, Zhifeng Zhong, Simin Zhou, Jun Yin, Fabo Shan, Chengzhong Yang, Li Jiao, Dewei Chen, and Jian Huang. Hypoxia-induced myocardial hypertrophy companies with apoptosis enhancement and p38-MAPK pathway activation. High Alt Med Biol. 00:00-00, 2024. Background: Right ventricular function and remodeling are closely associated with symptom severity and patient survival in hypoxic pulmonary hypertension. However, the detailed molecular mechanisms underlying hypoxia-induced myocardial hypertrophy remain unclear...

We investigated the inter- and intra-species differences of leaf vein traits of three dominant Quercus species, Q. wutaishanica , Q. aliena var. acutiserrata , and Q. variabilis of Niubeiling (subtropical humid climate) and Taohuagou (warm temperate semi-humid climate), located in the eastern and western Qinling Mountains. The nine examined leaf vein traits included primary leaf vein width, secondary leaf vein width, mean fine vein width, primary vein density, fine vein density, vein areole diameter, areole density, 3D fine vein surface area, and fine vein volume...

OBJECTIVE: To investigate the prevalence and influencing factors of isolated diastolic hypertension (IDH) in the Tibetan population in Tibet and to provide some evidence for the prevention and control of hypertension and other related diseases in high-altitude areas. METHODS: A multistage stratified whole-group random sampling method was used to enroll participants from Ngari Prefecture, Nagqu City, Shannan City, and Lhasa City, Tibet. A total of 3918 native Tibetans with complete data were enrolled in the survey between June 2020 and August 2023...

INTRODUCTION: Amidst the challenging environmental conditions characterized by low oxygen levels and cold temperatures on the plateau, alterations in nutrient supply emerge as pivotal factors influencing the survival and reproduction of yaks. Intensive feeding stands out as a substantial mechanism for nutrient provision, initiating discernible changes in the host's rumen flora. Within the extreme natural conditions prevailing in the plateau area of northwest Yunnan, China, there exists a con-strained comprehension of the variations in rumen microflora, fermentation parameters, and growth responses exhibited by yaks subjected to intensive feeding...

What is known, sports performance is impacted by a variety of factors. While most people understand the importance of training, proper nutrition, and adequate rest, not as many recognize the impact of environmental factors on athletic performance. This paper investigates the race strategies of Chinese triathletes in different competition environments, with a focus on the performance of professional triathletes during the Olympic Distance Triathlon held in China between 2015 and 2021. Data from 984 athletes who competed in 26 races were analyzed to evaluate the sensitivity of the three splits of swimming, cycling, and running to overall triathlon performance under different temperature (low, normal, and high), altitude (low, normal, and high), and waters (sea, river, and still waters) conditions...

Long-term high altitudes (HA) exposure's impact on cognition has yielded inconsistent findings in previous research. To address this, we conducted a meta-analysis of 49 studies (6,191 individuals) to comprehensively evaluate this effect. Moderating factors such as cognitive task type, altitude (1,500-2,500m, 2,500-4,000m, and above 4,000m), residential type (chronic and lifelong), adaptation level and demographic factors were analyzed. Cognitive tasks were classified into eight categories: perceptual processes, psychomotor function, long-term memory, working memory, inhibitory control, problem-solving, language, and others...

INTRODUCTION: Many studies have shown that the functional adaptation of immigrants to high-altitude is closely related to oxygen transport, inflammatory response and autonomic nervous system. However, it remains unclear how human attention changes in response to hypoxia-induced neurophysiological activity during high-altitude exposure. METHODS: In the present study, we analyzed the relationship between hypoxic-induced neurophysiological responses and attention networks in 116 immigrants (3,680 m) using an attention network test to simultaneously record electroencephalogram and electrocardiogram in combination with specific routine blood markers...