High Altitude Areas Research Articles

Safety assessment of slope on in-service dump under severe dry–wet cycles at high-altitude

This study aimed to evaluate the safety of dump slopes in high-altitude areas subjected to severe dry–wet cycles. The slope of No. 1 and No. 2 in-service dumps in limestone mining areas for cement in high-altitude mining areas is taken as the research object. The unsaturated soil shear strength and matrix suction distribution equations were imported based on the unsaturated–saturated seepage theory. Therefore, the evolution characteristics of the unsaturated–saturated seepage field in the dump are analyzed by numerical calculation, and the safety state of the dump slope is evaluated. The results indicated the following rules: under the action of four dry–wet cycles, the surface soil of the dump slope changes from an unsaturated state to a saturated state. Furthermore, with the increase in the times of the dry–wet cycle, the maximum vertical displacement of the No. 1 and No. 2 dump slopes increased. The numerical calculations of the maximum cumulative vertical displacement of the slope were consistent with the actual monitoring data. The factor of safety of the dump slope decreased continuously with the increase in the times of dry–wet cycles. Nevertheless, it still met the safety and stability standards. It was concluded that the slope of the in-service dump remains stable after enduring four severe cycles of dry–wet.

Simulation Study of the Air Separation Performance of Cr-MIL-101 in High-Altitude Environments

The most severe challenge for troops in a high-altitude environment is hypoxia. Pressure swing adsorption coupled with membrane separation is an ideal solution for oxygen production in high-altitude areas, but the molecular sieve membranes and organic membranes used in this technique are greatly affected by the ambient temperature, humidity, and pressure. Compared with traditional porous materials, metal-organic frameworks (MOFs) have outstanding features such as low densities, large specific surface areas, high crystallinities, and flexible structures. Cr-MIL-101 (MIL: Matérial Institut Lavoisier) and its derivatives are MOFs with high nitrogen adsorption capacities and can be used for oxygen production by air separation. However, since the plateau climate is complex, the applicability of Cr-MIL-101 for oxygen production in high-altitude environments awaits clarification. Therefore, this study constructed a molecular model of Cr-MIL-101, simulated the adsorption equilibrium of N2 and O2 molecules on this material using the grand canonical Monte Carlo (GCMC) method, and obtained their adsorption isotherms and densities. At 298 K and 100 kPa, the maximum adsorption capacities of Cr-MIL-101 for N2 and O2 were 0.94 per cell and 0.23 per cell, respectively. While at 238 K and 100 kPa, the maximum adsorption amounts of Cr-MIL-101 for N2 and O2 were 5.10 and 1.07 per cell, respectively. The thermodynamic parameters and adsorption equilibrium parameters during the adsorption process were analyzed. The conclusion of this study provides theoretical support for optimizing the N2/O2 separation performance of Cr-MIL-101 in high-altitude environments.

Analysis of the spatial and temporal distribution characteristics of AOD in typical industrial cities in northwest China and the influence of meteorological factors

The spatiotemporal distribution characteristics of AOD in Lanzhou City over the past decade, as well as the influence of meteorological factors, were analyzed using the MODIS MCD19A2 dataset from 2011 to 2022. Spatial Distribution: The annual average AOD in the study area was found to be 0.278. High AOD values were observed in the main urban area and surrounding low-altitude regions, while low AOD values were observed in the high-altitude mountainous areas in the northwest and southeast. The main urban area exhibited significantly higher AOD levels compared to the three surrounding counties. Temporal Trends: Influenced by air pollution control policies, the AOD in Lanzhou City started decreasing notably from 2014, with a total decrease of −27.18%. The overall trend displayed fluctuations and a downward pattern. The seasonal variation of AOD in Lanzhou City was evident, with the order of magnitude being spring > winter > autumn > summer. The AOD in Yuzhong County was particularly high in spring. There is spatial heterogeneity in the impact of meteorological factors on AOD in Lanzhou. Temperature exhibits greater significance in the central part of Lanzhou, while precipitation shows greater significance in the eastern part of the city, and wind speed is notably significant in the western and eastern parts of Lanzhou. Temperature, relative humidity, and wind speed are positively correlated with AOD, while precipitation and atmospheric pressure are negatively correlated with AOD. Three primary sets of interacting factors were identified: temperature and wind speed, temperature and relative humidity, and temperature and precipitation.

Improved stacked ensemble with genetic algorithm for automatic ECG diagnosis of children living in high-altitude areas

Electrocardiogram (ECG) is a commonly used diagnostic tool in clinical practice that plays a vital role in the diagnosis and treatment of various heart diseases. Previous studies have indicated that the incidence of heart disease in children living in high-altitude areas is significantly higher than those in low-altitude areas, which increases the demand for ECG examinations in these regions. However, there is a lack of research and technology that focus on automatic ECG diagnosis for children in high-altitude areas. This study utilized electronic medical records of pediatric electrocardiograms (ECGs) from high-altitude areas in Yunnan Province, China as research data. An improved genetic algorithm (GA) was employed to find the best combination of base classifiers, and a stacked ensemble approach was utilized to develop a reliable model for automatic diagnosis of pediatric ECGs. The developed model is capable of identifying abnormal ECGs and classifying heart rhythm types into four categories: normal sinus rhythm, sinus tachycardia, sinus bradycardia, and other arrhythmias. The model was tested and compared with commonly used classification methods. The results show that the model developed in this paper exhibits better performance in terms of accuracy, recall, and F1 score. The model’s classification effectiveness was further demonstrated by creating a receiver operating characteristic (ROC) curve. Finally, feature importance analysis highlighted the significance heart rate, developmental stage, and QRS complex axis deviation angle in the model.

Altitude Correction Method for Audible Noise of ± 800 kV UHVdc Overhead Transmission Line and its Engineering Application

With the improvement of the voltage level of DC overhead transmission lines (OHTLs), the audible noise (AN) caused by the corona discharge of conductors is an increasingly serious problem. AN has become a critical parameter that determines the selection of conductors, line structures and specifications for UHVdc OHTLs in high-altitude areas. To study the altitude correction method of AN for UHVdc OHTLs, we erected 6 × 720 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 6 × 900 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> conductors on DC full-scale test lines located at altitudes of 4,300 m and 50 m, respectively. We carried out an experimental study on AN over a long period and obtained its distribution law at high and low altitudes and its altitude-related increment. At the same time, on four DC reduced-scale test lines located at 4,300 m, 3,400 m, 1,700 m and 50 m above sea level, 6 × 95 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> conductors were erected for experiments. The law that the AN of the DC OHTL shows a nonlinear change with increasing altitude is obtained. Based on the combination of full-scale and reduced-scale tests, an altitude correction method of AN for UHVdc OHTLs considering the influences of both altitude and electric field strength on the conductor surface is proposed. From 0 to 4,300 m above sea level, when the maximum electric field strength on the conductor surface is 19 kV/cm, the increase in AN calculated with the formula suggested by this article is only 55% of the value calculated with the method recommended by the EPRI. The altitude correction formula of AN proposed herein is applicable to the design of UHVdc OHTLs in high-altitude areas, which can greatly save line investment while meeting the requirements of environmental protection.

Brainstem auditory evoked potentials in newborn infants born in a high-altitude area.

Introduction. A non-invasive and safe way to assess neurophysiological parameters in newborn infants is the evaluation of brainstem auditory evoked potentials (BAEPs). Objective. To assess the latencies and wave intervals of BAEPs in healthy newborn infants born in a high-altitude area (Cusco, 3399 MASL). Population and methods. Cross-sectional and prospective study. Newborn infants younger than 14 days of age, discharged less than 7 days after birth, were assessed to determine BAEP values at intensities of 70 dB, 80 dB, and 90 dB. The study variables were gestational age, birth weight, and type of delivery. The median differences in wave latencies and intervals were estimated according to gestational age and birth weight. Results. A total of 96 newborn infants (17 preterm infants) were assessed. The median latencies of waves I-V at 90 dB were for wave I: 1.56 ms, wave II: 2,74 ms, wave III: 4.37 ms, wave IV: 5.62 ms, and wave V: 6.63 ms. The latency of wave I for 80 dB was 1.71 ms and for 70 dB, 1.88 ms. Wave intervals (I-III, III-V, I-V) were 2.8 ms, 2.2 ms, and 5.0 ms, respectively, without differences among intensities (p > 0.05). Prematurity and low birth weight were associated with a longer wave I latency (p < 0.05). Conclusions. Here we describe adjusted BAEP latency and interval values for newborn infants born at high altitude. At different sound intensities, we identified differences in wave latencies, but not in interwave intervals.

Incidence of hailstorms damage and strategies to minimize its effects on large cardamom (Amomum subulatum Roxburgh) plantations in Sikkim, North East India

Among the extreme weather events, hailstorm in recent past caused significant damage of large cardamom crop in Sikkim. In high altitude area of Sikkim, hailstorms generally occurrs in the month of March and April and caused severe damage to large cardamom plantations. In this paper, a detailed account of incidence of hailstorm damage and strategies to minimize its effects on large cardamom plantations are discussed. Frequency distribution of hailstorm showed that during last eight years hailstorm in Pangthang area of Sikkim occurred between 1427 to 1532 hrs and it continued for around 37 minutes on average. However, in Kabi area of North Sikkim hailstorm generally occurs during 1621 to 1628 hrs and it continues for around 21.25 minutes. Hailstorms varied in size from 0.5 to 1.0 cm in diameter. Damage caused by the hailstorms on plant tissue depends mainly on its size, duration of the storm event and the condition of the plant tissue when the injury occurs. Large cardamom being a broad leaved plant, the lamina tears parallel to the veins. Physical damage to floral parts of large cardamom plants due to hailstorm occurred at the flowering stage and depending on the extent of damage the yield of the plant was also affected in the subsequent crop season. Frequent hail episodes are identified and measures to minimize the damage of large cardamom plantations are discussed. The information generated in this study was found to be very useful in minimizing large cardamom crop loss through operational agromet services launched by the India Meteorological Department/Ministry of Earth Sciences in collaboration with the Agromet Field Units (AMFUs) located at Gangtok and ICAR-NOFRI, Tadong through Krishi Vigyan Kendra-East Sikkim, Ranipool.&#x0D;

Application of Machine Learning to Predict COVID-19 Spread via an Optimized BPSO Model.

During the pandemic of the coronavirus disease (COVID-19), statistics showed that the number of affected cases differed from one country to another and also from one city to another. Therefore, in this paper, we provide an enhanced model for predicting COVID-19 samples in different regions of Saudi Arabia (high-altitude and sea-level areas). The model is developed using several stages and was successfully trained and tested using two datasets that were collected from Taif city (high-altitude area) and Jeddah city (sea-level area) in Saudi Arabia. Binary particle swarm optimization (BPSO) is used in this study for making feature selections using three different machine learning models, i.e., the random forest model, gradient boosting model, and naive Bayes model. A number of predicting evaluation metrics including accuracy, training score, testing score, F-measure, recall, precision, and receiver operating characteristic (ROC) curve were calculated to verify the performance of the three machine learning models on these datasets. The experimental results demonstrated that the gradient boosting model gives better results than the random forest and naive Bayes models with an accuracy of 94.6% using the Taif city dataset. For the dataset of Jeddah city, the results demonstrated that the random forest model outperforms the gradient boosting and naive Bayes models with an accuracy of 95.5%. The dataset of Jeddah city achieved better results than the dataset of Taif city in Saudi Arabia using the enhanced model for the term of accuracy.

Spring photosynthetic phenology of Chinese vegetation in response to climate change and its impact on net primary productivity

In the context of global warming, the advancement of spring phenology in northern and temperate regions due to increased temperatures has been widely reported. Early and delayed start of the photosynthetic period (SOP) directly affects the vegetation net primary productivity (NPP). However, the interrelationship between climate change, the SOP, and the NPP is unclear. In this paper, we use the dynamics of decadal daily solar-induced chlorophyll fluorescence data to calculate the response of Chinese vegetation photosynthetic phenology to climate change and its impact on the NPP over the last 20 years. The results found that over the last 20 years, the average SOP in China was on the 123rd day of the year, and the SOP has advanced at an average rate of 4.3 d (10 a)−1, with a faster trend of SOP advancement in highland and high-altitude areas. 64% of SOP in China is controlled by temperature; 36% of the SOP in China is controlled by precipitation, and the relative importance of temperature and precipitation was reversed as the precipitation gradient decreased, with SOP dominated by temperature when pre-season precipitation ≧300 mm, and SOP dominated by precipitation when pre-season precipitation ≦300 mm. Finally, we find that climate change indirectly increases vegetation NPP by advancing SOP. Our study emphasizes the importance of precipitation on phenology. It provides a scientific basis for understanding and predicting the response of spring photosynthetic phenology to climate change and the contribution of spring phenology to carbon estimation in terrestrial ecosystems.

Construction Technology of Warm Mix Asphalt Pavement in Cold High-Altitude Areas

With the continuous development of domestic highway construction, highway civil engineering and servicelevel quality have attracted much attention. Good pavement quality and high-quality service make people feel comfortable and smooth when traveling. High-quality pavement can significantly reduce the probability of traffic accidents. At present, there is a direct relationship between pavement quality and pavement construction operations. Carrying out pavement construction operations in cold high-altitude areas requires a reasonable selection of construction equipment and methods. The application of warm-mix asphalt pavement construction technology can ensure pavement quality. Therefore, this paper analyzes the advantages of warm-mix technology, the environmental characteristics of cold high-altitude areas, and construction preparations, and discusses the construction technology of warm-mix asphalt pavement in cold high-altitude areas in detail, to improve the overall road quality of cold high-altitude areas.

Evolutionary Characteristics of Daytime and Nocturnal Precipitation Heterogeneity in Gansu Province, Northwest China

The diurnal variation in precipitation and its evolution are important foundations for understanding the regional impact of climate change and the parameterization of the model. Based on the daily precipitation data set of 23 national meteorological stations during 1970–2019, the spatial and temporal distribution characteristics of precipitation concentration degree (PCD) and precipitation concentration period (PCP) in Gansu province were evaluated on daytime and nocturnal scales. The results show the following: (1) Annual precipitation ranges from 69.1 ± 24.7 mm to 578.3 ± 96.6 mm, mainly (54.1 ± 2.6%) occurring at night, and the spatial distribution of the nocturnal precipitation rate is positively (r = 0.53, p &lt; 0.01) correlated with annual precipitation; the wetting trend (12.7 mm/10 a, p &lt; 0.01) in the past 50 years is obvious, and is mainly dominated by the frequency of precipitation (r = 0.58, p &lt; 0.001), with both performing better during the day. (2) Most PCD is located between 0.55 and 0.75, showing a basic distribution pattern for daytime greater than nocturnal, higher values, and stronger interannual fluctuations in arid areas; the significant decreasing trend (p &lt; 0.05) of PCD is very clear and highly consistent, especially in the high-altitude area, and the increase in precipitation in the dry season and the improvement in precipitation uniformity in the wet season play a key role. (3) PCP often fluctuates slightly around the 39th–41st pentad, but the general rule that daytime values are smaller than night values and the interannual variability is larger in arid areas also requires special attention; PCP has shown a relatively obvious advance trend in a few regions, but this is because the prominent and complex changes in the monthly precipitation distribution pattern have not been fully reflected. Along with continuous humidification, the decrease in PCD and the advance of PCP are likely to be the priority direction of precipitation evolution in the arid region of Northwest China, especially during the day. These findings provide a new perspective for understanding regional climate change.

Macroinvertebrates of Altai mountain rivers: factors of their formation and features of distribution within altitudinal gradient

With an increase in altitude, both abiotic and biotic conditions in mountain watercourses change. To assess the features of spatial distribution of macroinvertebrates as well as to identify the driving factors of this dynamics, the data on species richness, abundance and biomass of EPT taxa (mayfly, stonefly, caddisfly) from 21 small mountain rivers of Altai were analyzed. By location, all rivers were divided into 4 groups: the ones running in the low-mountain (&lt;1000 m asl) zone, in the low (1000–1500) and upper (1500–2000) parts of the middle mountains and in the high-mountain (&gt;2000 m asl) zone. A total of 71 EPT macroinvertebrate taxa were recorded in the studied streams. Species richness (according to the average species number per sample) as well as abundance and biomass of macroinvertebrates decreased with an increase in altitude. The maximum variance in structural indicators of communities appeared due to the combined influence of the location of the altitudinal zone and phytoplankton development level (estimated by the content of chlorophyll a). At the same time, categorical predictors (both abiotic and biotic) included in the analysis better explained the variability of diversity-related indicators than that of abundance and biomass. When developing the environmental monitoring programs for mountain watercourses, the identified trends in reduction (with altitude) of species richness of macroinvertebrate taxa responsible for the formation of taxonomically poor and strongly vulnerable communities in high-altitude areas should be taken into account.

Diurnal source apportionment of organic and inorganic atmospheric particulate matter at a high-altitude mountain site under summer conditions (Sierra Nevada; Spain)

High-altitude mountain areas are sentinel ecosystems for global environmental changes such as anthropogenic pollution. In this study, we report a source apportionment of particulate material with an aerodynamic diameter smaller than 10 μm (PM10) in a high-altitude site in southern Europe (Sierra Nevada Station; SNS (2500 m a.s.l.)) during summer 2021. The emission sources and atmospheric secondary processes that determine the composition of aerosol particles in Sierra Nevada National Park (Spain) are identified from the concentrations of organic carbon (OC), elemental carbon (EC), 12 major inorganic compounds, 18 trace elements and 44 organic molecular tracer compounds in PM10 filter samples collected during day- and nighttime. The multivariate analysis of the joint dataset resolved five main PM10 sources: 1) Saharan dust, 2) advection from the urbanized valley, 3) local combustion, 4) smoke from a fire-event, and 5) aerosol from regional recirculation with high contribution of particles from secondary inorganic and organic aerosol formation processes. PM sources were clearly associated with synoptic meteorological conditions, and day- and nighttime circulation patterns typical of mountainous areas. Although a local pollution source was identified, the contribution of this source to PM10, OC and EC was small. Our results evidence the strong influence of middle- and long-range transport of aerosols, mainly from anthropogenic origin, on the aerosol chemical composition at this remote site.

Numerical Study on the Influence of Fault Structure on the Geostress Field

A geostress field continuously evolves with long-term tectonic activity. A fault, as a general product of tectonic movements, has a great influence on the geostress field in the vicinity. To analyze the geostress field characteristics and influencing factors near the fault fracture zone in high-altitude areas, this study takes the Dianda-Piru fault on the Qinghai–Tibet Plateau as its research object. Based on the geological conditions and in situ stress measurement data in the study area, a refined numerical model was established using numerical simulation to invert the geostress field in the vicinity of the fault fracture zone, and a quantitative analysis of the factors influencing the geostress distribution was carried out. The results show that the overall relationship between large horizontal principal stress σH, vertical stress σv, and small horizontal principal stress σh is σH &gt; σv &gt; σh, and the surrounding rock stress is dominated by horizontal stress. Geostress is released within the fault fracture zone to a certain extent, and there is a certain degree of stress concentration within the intact rock mass on the upper plate of the fault. The elastic modulus has a greater influence on the geostress field near the fracture structure area than Poisson’s ratio, and the range of the stress-weakening zone increases with the decrease in the elastic modulus. The maximum principal stress inside the fault increases with the increase in the angle between the fault strike and regional principal stress, while the deflection angle of the surrounding principal stress direction decreases with the increase in this angle. The study of the distribution law of geostress fields with developed fracture structures can provide theoretical guidance for the sustainable development of engineering construction in tectonically active areas.

Thermal compensation reduces DNA damage from UV radiation

Increases in ultraviolet radiation (UVR) correlate spatially and temporally with global amphibian population declines and interact with other stressors such as disease and temperature. Declines have largely occurred in high-altitude areas associated with greater UVR and cooler temperatures. UVR is a powerful mutagenic harming organisms largely by damaging DNA. When acutely exposed to UVR at cool temperatures, amphibian larvae have increased levels of DNA damage. Amphibians may compensate for the depressive effects of temperature on DNA damage through acclimatisation, but it is unknown whether they have this capacity. We reared striped marsh frog larvae (Limnodynastes peronii) in warm (25 °C) and cool (15 °C) temperatures under a low or moderate daily dose of UVR (10 and 40 μW cm−2 UV-B for 1 h at midday, respectively) for 18–20 days and then measured DNA damage resulting from an acute high UVR dose (80 μW cm−2 UV-B for 1.5 h) at a range of temperatures (10, 15, 20, 25, and 30 °C). Larvae acclimated to 15 °C and exposed to UVR at 15 °C completely compensated UVR-induced DNA damage compared with 25 °C acclimated larvae exposed to UVR at 25 °C. Additionally, warm-acclimated larvae had higher DNA damage than cold-acclimated larvae across test temperatures, which indicated a cost of living in warmer temperatures. Larvae reared under elevated UVR levels showed no evidence of UVR acclimation resulting in lower DNA damage following high UVR exposure. Our finding that thermal acclimation in L. peronii larvae compensated UVR-induced DNA damage at low temperatures suggested that aquatic ectotherms living in cool temperatures may be more resilient to high UVR than previously realised. We suggested individuals or species with less capacity for thermal acclimation of DNA repair mechanisms may be more at risk if exposed to changing thermal and UVR exposure regimes.

Relationship between cardiorespiratory fitness and executive function of Chinese Tibetan adolescents aged 13–18

ObjectivesExplore the correlation between cardiorespiratory fitness (CRF) and execution function (EF) of Chinese Tibetan adolescents at high altitude (HA) areas. DesignA cross-sectional survey was used to study 1138 participants aged 13–18 (47.72% boys) at baseline. MethodsLhasa (3650 m), Nagqu (4500 m), Qamdo (3500 m), and Nyingchi (3100 m) in China were chosen. CRF was measured by the 20 m shuttle run test (20mSRT) and a subsequent estimation of their maximal oxygen consumption (V̇O2max) was calculated using the Léger equations. The three core EFs (inhibition, working memory, and cognitive flexibility) were tested by a modified Eriksen flanker, N-back, and a more-odd shifting. The association between CRF and EF was explored by Pearson correlation, one-way ANOVA, and stratified regression. ResultsThe reaction time (RT) of 1-back, cognitive flexibility with V̇O2max showed a declining trend, (F = 34.475, 27.498, P < 0.01). Interestingly, 2-back RT went up and then went down with V̇O2max. (F = 29.55, P < 0.01). After increasing V̇O2max as a variable, a stratified regression analysis with the RT for 1-back, 2-back, and cognitive flexibility showed that ΔR2 equaled 0.107 ms, 0.071 ms, and 0.091 ms, respectively (P < 0.01). With V̇O2max increased by 1 mL/kg/min, the RT of 1-back, 2-back, and cognitive flexibility shortened 14.697 ms, 15.689 ms, and 11.771 ms, respectively. ConclusionsCRF was positively associated with working memory, and cognitive flexibility development among Chinese Tibetan adolescents living at HA areas, respectively.

Economic Sanctions by Non-Democracies: A Study of Cases from China and Russia

Abstract Do political institutions matter in explaining how economic sanctions are used? The current understanding of sanctions imposed by non-democratic sender countries is limited in the literature, as existing theories predominantly focus on the behaviors and strategies of democratic sender countries, leaving a notable gap in systematic comprehension. Using the existing dataset on sanctions, we theoretically and empirically distinguished characteristics of sanctions by non-democracies in terms of their motivating issues, types, and objectives. We also assessed our arguments based on recent data on Chinese and Russian sanctions since 2005 and a case illustration of China's de facto sanctions on South Korea for the Terminal High Altitude Area Defense deployment beginning in 2017.

The benefits of early continuous renal replacement therapy in critically ill patients with acute kidney injury at high-altitude areas: a retrospective multi-center cohort study

Severe hypoxia would aggravate the acute kidney injury (AKI) in high-altitude areas and continuous renal replacement therapy (CRRT) has been used to treat critically ill patients with AKI. However, the characteristics and outcomes of CRRT in critically ill patients at AKI in high altitudes and the optimal timing of CRRT initiation remain unclear. 1124 patients were diagnosed with AKI and treated with CRRT in the ICU, comprising a high-altitude group (n = 648) and low-altitude group (n = 476). Compared with the low-altitude group, patients with AKI at high altitude showed longer CRRT (4.8 vs. 3.7, P = 0.036) and more rapid progression of AKI stages (P < 0.01), but without any significant minor or major bleeding episodes (P > 0.05). Referring to the analysis of survival and kidney recovery curves, a higher mortality but a lower possibility of renal recovery was observed in the high-altitude group (P < 0.001). However, in the high-altitude group, the survival rate of early CRRT initiation was significantly higher than that of delayed CRRT initiation (P < 0.001). The findings showed poorer clinical outcomes in patients undergoing CRRT for AKI at high altitudes. CRRT at high altitudes was unlikely to increase the adverse events. Moreover, early CRRT initiation might reduce the mortality and promote renal recovery in high-altitude patients.

Quantifying systemic molecular networks affected during high altitude de-acclimatization

High altitude acclimatization and disease have been the centerpiece of investigations concerning human health at high altitude. Almost all investigations have focused on either understanding and ameliorating high altitude disease or finding better methods of acclimatization/training at high altitude. The aspect of altitude de-induction/de-acclimatization has remained clouded despite the fact that it was documented since the first decade of twentieth century. A few recent studies, particularly in China, have stated unanimously that high altitude de-acclimatization involved multiple observable clinical symptoms ranging from headache to abdominal distention. These symptoms have been collectively referred to as “high altitude de-acclimatization syndrome” (HADAS). However, computational omics and network biology centric investigations concerning HADAS are nascent. In this study, we focus on the quantitative proteo-informatics, especially network biology, of human plasma proteome in individuals who successfully descended from high altitude areas after a stay of 120 days. In brief, the protein list was uploaded into STRING and IPA to compute z-score based cut-offs which were used to analyze the directionality and significance of various identified protein networks as well as the proteins within them. Relevant upstream regulators extracted using computational strategies were also validated. Time-points till the 180th day of de-induction have been investigated to comparatively assess the changes in the plasma proteome and protein pathways of such individuals since the 7th day of arrival at altitude. Our investigation revealed extensive effects of de-induction on lipid metabolism, inflammation and innate immune system as well as coagulation system. This novel study provides a conceptual framework for formulating therapeutic strategies to ease the symptoms of HADAS during de-acclimatization. Such strategies should focus on normalization of lipid metabolism, inflammatory signaling and coagulation systems.

A Fault Location Analysis of Optical Fiber Communication Links in High Altitude Areas

Breakage and damage of fiber optic cable fibers seriously affects the normal operation of fiber optic networks, and it is important to quickly and accurately determine the type and location of faults when they occur. Unlike the old traditional methods, the advantages of wavelet transform in singular signal detection and signal filtering are used to analyze the Optical Time Domain Reflectometer curve signal and the fault detection method of fiber communication links with no relay and a large span in a high altitude area is given, which realizes the accurate detection and location of optical fiber communication link fault events under strong noise. The proposed technology detects fiber optic faults in high-altitude environments, with an average measurement accuracy improvement of 9.8%. The maximum distance for detecting fiber optic line faults is up to 250 km, which increases the system power budget. In the simulation experiment results, the infrastructure nodes of the Wuhan FiberHome Laboratory successfully verified the superiority of this technology. The method has been directly applied to the on-site detection of ultra long optical fiber links in high-altitude areas, which has good financial significance and has certain reference significance for the future real-time detection of optical fiber cables.