Altitude Difference Research Articles

Effects of Altitude Differences on the Performance of Broiler Chicken Kept in Closed House Cage

This study aimed to examine the effect of differences in altitude on the performance of broiler chickens. The experimental design used was a completely randomized design (CRD) with 3 treatments and 8 replications. For this research, the broiler chickens were reared in closed house cages at different altitudes: lowlands, medium lands, and highlands with the same Standard Operation Procedure (SOP). The treatments applied were T1 (broilers reared at an altitude of ± 1000 meters). The data were analyzed to determine the treatment effect using Duncans Multiple Distance Test. The parameters measured were feed consumption, body weight gain (WG), feed conversion ratio (FCR), index performance (IP) and income over feed cost (IOFC). The results showed that altitude had a significant effect (P

An Algorithm to Predict E-Bike Power Consumption Based on Planned Routes

E-bikes, i.e., bikes equipped with a small electrical engine, are becoming increasingly widespread, thanks to their positive contribution to mobility and sustainability. A key component of an e-bike is the battery that feeds the drive unit: clearly, the higher the capacity of the battery, the longer the distances that the biker will cover under engine support. On the negative side, the additional weight incurred by the electric components is likely to ruin the riding experience in case the battery runs out of power. For this reason, an integrated hardware-software system that provides accurate information about the remaining range is essential, especially for older or “not-in-shape” bikers. Many e-bikes systems are already equipped with a small control unit that displays useful information, such as speed, instantaneous power consumption, and estimated range as well. Existing approaches rely on machine learning techniques applied to collected data, or even on the remaining battery capacity and the assistance level required by the drive unit. They do not consider crucial aspects of the planned route, in particular the difference in altitude, the combined weight of bike and biker, and road conditions. In this paper, we propose a mathematical model implemented in an application to compute battery consumption, and hence the presumed remaining range, in a more accurate way. Our application relies on external sources to compute the route and the elevation data of a number of intermediate points. We present the mathematical model on which our application is based, we show the implemented application in shape of an app, and we report the results of the experiments.

Karst relief of the Mali me Gropa Massif, central Albania

The mid-altitude mountain massif of Mali me Gropa is located in the central part of Albania, rises to an altitude of 1500–1800 m a.s.l., is composed mostly of Mesozoic limestone, and is characterized by extensive surface karst development. The karst relief is dominated by “doline” morphology including “polygonal” karst. Detailed geomorphological analysis of the western part of the Mali me Gropa massif (so-called Western Massif) by means of GIS methods is used to determine and explain the morphometric and morphological diversity of the area’s topography. Based on a homogeneity criterion, a number of geomorphological units with specific kinds of karst relief have been distinguished within the massif. The differences in karst sculpture concern the size (diameter) of dolines and depressions, their depth, shape and symmetry, orientation, density of occurrence and spatial pattern, which provide the basis for distinguishing geomorphological units. The spatial differentiation of the karst relief is explained by the influence of factors which are evolutionary (geological and geomorphological evolution of the massif), hypsometric (altitude difference of terrains) and geomorphologic-structural (inclination of the slopes and layers). The relatively poor expression of open karst conduits (i.e. caves and vertical shafts) on the surface of the massif may result from the relative immaturity of the epikarst zone, the widespread occurrence of residual cover on the plateau, and the accumulation of large amounts of clay material in dolines and depressions. Detailed hydrogeological studies show, however, high karst permeability and dominance of conduit flow. Considering the high geomorphological landscape and ecological value of the area, it should be granted the status of a nature reserve or national park. Geomorphological and karstological research within the massif should be continued as it represents a type of karst found also in other parts of Albania. This type of karst area is of great economic (groundwater reserves) and natural protection (environmental) importance.

The effect of altitude difference on gastrointestinal bleeding in the chronic period

Aim: The susceptibility to gastrointestinal bleeding is observed with an increase in altitude. There is no recommendation regarding altitude in terms of drug selection and dose to be used in diseases requiring antiaggregant and anticoagulant use. In this study, we aimed to determine whether there is a difference between gastrointestinal bleeding requiring hospitalization due to the use of antiaggregant and/or anticoagulant therapy between two populations living at different altitudes. 
 Material and Method: This retrospective study was performed in two secondary care hospitals. Patients from Group B living in villages with an altitude of 9842 ft and above and Group F patients living in an area with an altitude of 30 ft were included. Patient’s demographic data, co-morbid diseases, antiaggregant and anticoagulant use, hemoglobin, hematocrit, MCV values and platelet count were noted.
 Results: The study included a total of 118 patients with gastrointestinal bleeding. There was no statistically significant difference between the groups in terms of the drugs used by the patients, the types and numbers of drugs.
 Conclusion: We found that there was no significant difference between the groups with different altitudes in terms of drugs used by patients with gastrointestinal bleeding, drug types and numbers.

Activity characteristics of the northeast moving Tibetan Plateau vortices in summer

The Tibetan Plateau Vortex (TPV) is mainly divided into east moving (E-TPV), northeast moving (NE-TPV) and so on according to its moving path after moving off the Tibetan Plateau (TP). Based on the database of TPV from 1979 to 2018, this paper mainly makes statistical analysis on the NE-TPV in summer. According to its moving-off position, NE-TPV is subdivided into westward vortex (denoted as NEI-TPV) and eastward vortex (denoted as NEII-TPV). In terms of source, structure, circulation, moving speed, life history and influence on precipitation, the characteristics of two types of NE-TPVs were analyzed and compared with E-TPV to reveal the activity characteristics of the NE-TPVs and the similarities and differences between them. The results show that: (1) The NEI-TPV is mainly generated in the northwest of the TP, while the NEII-TPV and E-TPV are generated in the whole TP. There are mainly three centers of vortex sources: west, middle and east. The eastern sources of TPV with different paths differ greatly in north-south location and concentration. The eastern source of NEI-TPV is northward and concentrated, while the E-TPV is southward and dispersed, and NEII-TPV is between the former two. (2) The intensity of NEII-TPV is stronger than that of NEI-TPV before moving off, and the ascending motion of these two is located near the vortex center. After moving off, the relative vorticity and vertical velocity of both of them weakened significantly, and the maximum upward movement of NEI-TPV moved to the northeast of the vortex, while the NEII-TPV is similar to E-TPV, and its rising region is located in the southeast of the vortex. (3) The moving direction before moving off and moving-off position of TPV is mainly affected by the 200 hPa westerly fluctuations, while after moving off, the moving direction is mainly affected by 500 hPa troughs and ridges. Among them, the Hetao High-Pressure Ridge is particularly important in blocking NE-TPV. (4) Besides the influence of altitude difference, the moving speed of TPV is closely related to its moving direction, so the TPV moving eastward move faster. (5) NEII-TPV and E-TPV have longer mean life history than NEI-TPV, meanwhile, they often result in a wider range of precipitation and a higher proportion of rainstorms. The precipitation of NEI-TPV is mainly located in the Hexi Corridor. While the precipitation of NEII-TPV is mainly located in the eastern part of Northwest China.

Inulin determination of yam bean tuber (Pacyrrhizus erosus l.) water extract from different altitude areas using TLC- Densitometry

Inulin is a polysaccharide with a lot of potential in the field of food and pharmaceuticals. Inulin can be found in yam bean tuber. Chemical constituents of yam bean tuber are inulin, pachyrion, and rotenone. The levels of inulin could be influenced by differences in the altitude of the cultivation area. The objective of this study was to determine the inulin of yam bean tuber extract from several areas in East Java based on the altitude difference, they are low (Gresik), middle (Kediri), and high (Malang), using validated TLC Densitometry method. The samples were extracted by the infusion method. The samples were put to silica gel TLC plates and developed using ascending chromatography with a mobile phase of 0.5:7:2 glacial acetic acid: methanol:  deionized water.  Densitometry at 380 nm was used to assess the intensity of inulin spots dipped in Aniline: diphenylamine: phosphoric acid (5:5:1), and winCATS software version 1.3.0 was used to quantify the results. A standard curve  meets the requirement of linearity (r=0.997; Vxo=3.847%), sensitivity (LOD=71.030 ng/spot, and LOQ=236.766 ng/spot), selectivity and specificity, Precision (RSD≤2.754 %), and accurate (% recovery ± RSD = 100.161 ± 1.839%). The results showed that the inulin content in yam tubers produced by areas with different altitudes had different inulin levels. The levels of inulin derived from the low altitude (Gresik) was 9.066 ± 1.218 %, middle (Kediri) was 7.776 ± 0.420 %, and high (Malang) was 6.796 ± 2.045 %. One-Way ANOVA test showed the significant difference between the levels of inulin from different altitude areas (p < 0.01), the highest inulin level comes from yam bean tuber from low altitude. Â

A Study of Blast Vibration Propagation Law under Negative Altitude Terrains

The propagation characteristics of blast waves and the prediction accuracy of blast vibration velocities along negative slopes are important because those can be used to guide engineering application and theoretical research. In this paper, the wave theory was applied to better understand the propagation mechanism of blast waves along negative slopes. Regression analysis was used for the Sadovsky and the CRSRI blast vibration velocity prediction models during on-site operations. The magnification of peak blast vibration velocity along a negative slope was introduced to determine the threshold altitude difference for the magnification effect to occur. Based on this parameter, the relative errors between the two prediction models were compared. The obtained results indicate that the superposition of incident and reflected blast waves on a negative slope creates the “slope effect” which locally amplifies the blast vibration velocity. The relative error of the CRSRI prediction model was as small as 17.53%, demonstrating a greater accuracy than Sadovsky’s prediction model. The magnification effect of a negative slope was observed at specific altitude differences and was more noticeable in the perpendicular direction. This paper creates a theoretical basis for studying the propagation mechanisms of blast vibration waves along negative slopes as well as predicting the blast vibration velocities.

Typology of Pure Deodar Forests Driven by Vegetation–Environment Relations in Manoor Valley, Northwestern Himalaya

The current research was carried out to characterize the phytosociology of the forests of one of Pakistan’s most valuable tree species (Deodar) across its native range. In this context, our main hypothesis was that, along the altitudinal gradient, we would find different plant communities that would be driven by different environmental variables (climatic, edaphic, and physiographic). Therefore, to assess the vegetation structure of the pure Deodar forests of the unexplored Manoor Valley (Northwestern Himalaya), Pakistan, frequent field visits were carried out during different seasons of 2015–2018. Ecological methods: Line transects sampling (23 stands) and phytosociological attributes were evaluated in relation to geographical and environmental variables. Various statistical software applications (i.e., PCORD, RStudio 4.0, and R 3.6.1) were used to examine all of the gathered data of plant species and environmental variables. A total of three different plant communities (Cedrus–Isodon–Cynodon, Cedrus–Cynodon–Dryopteris, and Sambucus–Cedrus–Desmodium) were identified by grouping 162 species and 23 stands in pure Deodar forests under the influence of geographic, slope, edaphic, and climatic variables, ranging from 1580.8 to 2373.8 m. The altitude (1936–2373 m), slope angle (25–85°), sandy (29–48%) and loamy soil texture, wind speed (1.45 ms−1), and temperature (25.8 °C) all had a strong influence on the Sambucus–Cedrus–Desmodium community. In contrast with this, the Cedrus–Cynodon–Dryopteris community showed a positively significant relationship with the northeastern slope, silty (32–58%) and sandy (15.8–55%) loamy soil texture, and barometric pressure (814.3 pa). Nonetheless, the Cedrus–Isodon–Cynodon community revealed a significant positive association with the northeastern to southwestern slope, pH (6.3), wet bulb (19.7), and dew point (17.7). We found significant differences (p < 0.001) among the three communities found in the pure Deodar forests in the four diversity indexes. The Sambucus–Cedrus–Desmodium community has the maximum number of plants (129 species), Shannon’s diversity (H’ = 3.7), and Simpson’s dominance (0.98) values among the recorded communities. The Pielou’s evenness index value was led by the Cedrus–Isodon–Cynodon community (0.97). Beta diversity showed a dissimilarity lower than 50% among the three communities. Simple term effects in the canonical correspondence analysis model revealed significant (p < 0.05) differences in altitude, slope angle, slope (southeastern), and wind speed variables. The present investigation sheds light on vegetation pattern and species contribution as a function of environmental gradients and provides a baseline for future studies.

Color Balance Method of Dense Point Cloud in Landslides Area Based on UAV Images

Landslides are a natural geological phenomenon and often cause economic losses, property damage, and loss of lives. The detection and recognition based on the dense point cloud derived from Unmanned Aerial Vehicle (UAVs) images play an important role in understanding the mechanism of landslides. However, the brightness difference of UAV images with large altitude differences usually makes the dense point cloud within a landslide area show color stratification, and the processing results of popular commercial and open-source software are not ideal. In this study, a multi-view UAV image brightness compensation method based on regular 3D points is proposed, and is combined with the open-source software OpenMVG and OpenMVS to obtain a dense point cloud with balanced color on the landslide’s surface. The selected study area is located in the active landslide region caused by the Tengqing coal mining area in Guizhou Province, China. The terrain following flight method was used to acquire complete high resolution UAV images of the study area. Experimental results show that the global gain and offset compensation methods proposed in this study can effectively reduce the 22.3% brightness difference in the overlapping area of the adjacent images. The comparison results and the processing results of other commercial software show that the method can be applied to the color balance of the dense point cloud for UAV images with large-altitude differences.

Effect of altitude differences on seed germination and seedling growth in Rhododendron luteum Sweet

The aim of this study is to encourage the use of Rhododendron luteum Sweet, distributed in high altitudes in its natural habitat, in planting designs and landscape architecture and to cultivate these plants by seed propagation. In this context, the effects of different altitudes on R. luteum germination and post-germination seedling growth were investigated. The germination success of R. luteum seeds collected at 3 different altitudes, 1,586 m, 1,760 m and 2,100 m a.s.l., was investigated under greenhouse conditions at a temperature of 25 ± 2 °C and humidity of 70 ± 2% and in soil, peat, soil + peat (5:5), peat + sand (7:3), soil + sand (7:3) and soil + peat + sand (4:4:2) propagation media. The post-germination seedling height, root length, and the number of leaves of the seedlings were determined. Different altitudes had significant effects (P < 0.05) on height, root length, and the number of leaves of the seedlings. The highest germination percentage was 76.69% with the seeds collected from 2,100 m. Furthermore, seedlings that grew from these seeds possessed the best seedling growth with a greater height, longer roots, and a greater number of leaves. Keywords: landscape architecture, Rhododendron luteum, seed propagation, variation

Reliability of the ERA5 in Replicating Mean and Extreme Temperatures across Europe

ERA5 is widely considered as a valid proxy of observation at region scales. Surface air temperature from the E-OBS database and 196 meteorological stations across Europe are being applied for evaluation of the fifth-generation ECMWF reanalysis ERA5 temperature data in the period of 1981–2010. In general, ERA5 captures the mean and extreme temperatures very well and ERA5 is reliable for climate investigation over Europe. High correlations ranging from 0.995 to 1.000 indicate that ERA5 could capture the annual cycle very well. However, the high mean biases and high Root Mean Square Error (RMSE) for some European sub-regions (e.g., the Alps, the Mediterranean) reveal that ERA5 underestimates temperatures. The biases can be mainly attributed to the altitude differences between ERA5 grid points and stations. Comparing ERA5 with the other two datasets, ERA5 temperature presents more extreme temperature and small outliers for regions southern of 40° latitude and less extreme temperatures in areas over the Black Sea. In Scandinavia, ERA5 temperatures are more frequently extreme than the observational ones.

Static analysis of tympanic membrane in aero-otitis media by three-dimensional model of the middle ear

The three-dimensional (3D) model of the middle ear is of great significance to the research of middle ear related diseases. The particular focus of this work is to simulate the impact of aircraft altitude and speed changes on the tympanic membrane (TM) during the descent phase, so as to analyze the pathogenesis of aero-otitis media and the mechanical response characteristics of TM under static pressure. The simulations showed that the stress and strain of TM increase as the altitude difference and speed of the aircraft increase, and the maximum stress and strain areas are consistent with the clinical observation of TM hyperemia. Therefore, among many prevention and treatment measures of aero-otitis media, it is a therapeutic method to directly balance the pressure difference between the inner and outer TM.

Upward Treeline Shifts in Two Regions of Subarctic Russia Are Governed by Summer Thermal and Winter Snow Conditions

Climate warming impacts on alpine treeline dynamics. However, we still lack robust assessments of the long-term impacts of climate on tree recruitment at the treeline, particularly in remote areas such as the subarctic regions of Russia subjected to different climate influences. We expected that the treelines in two regions may have different features and dynamics patterns. We analyzed climate variables and assessed treeline dynamics by quantifying recruitment using the tree rings of ca. 7000 trees of four species (Betula pubescens Ehrh. ssp. tortuosa, Pinus sylvestris L., Picea abies Ledeb. ssp. obovata, Larix gmelinii Rupr.) along 14 altitudinal transects (series of study plots). We compared the Khibiny Massif (Kola Peninsula) and the western Putorana Plateau, subjected to oceanic and continental influences, respectively. In both regions, summers became warmer, and winters became snowier during the past century. At the low part of the treeline ecotone, tree recruitment has slowly increased since the mid-18th century at the Putorana Plateau and the mid-19th century at the Khibiny but accelerated in the early 20th century at both regions and reached a maximum peak in the second half of the past century. Treeline encroachment intensified in the 1930s at the Khibiny and the 1950s at the Putorana Plateau. Trees encroached in the tundra leading to upward treeline shifts in the late 20th century. The slope exposure affected the rates of treeline shift with higher upward advances on southern-oriented slopes. Tree recruitment and early-winter precipitation were positively correlated. The differences in species composition, treeline altitude and influences of slope orientation on treeline dynamics can be explained primarily by differences in the degree of continentality. The abundance of saplings in both regions allows the future encroachment of trees into tundra and further treeline upward shifts to be forecast.

Predicting Snowmelt Runoff at the Source of the Mountainous Euphrates River Basin in Turkey for Water Supply and Flood Control Issues Using HEC-HMS Modeling

Predicting the runoff from snowpack accumulated in mountainous basins during the melting periods is very important in terms of assessing issues such as water supply and flood control. In this study, the Hydrological Engineering Center–Hydrological Modeling System (HEC-HMS) was used to simulate snowmelt runoff in the Kırkgöze–Çipak Basin that has a complex topography where altitude differences range from 1823 m to 3140 m above the sea level. The Kırkgöze–Çipak Basin, located in eastern Turkey, is a basin where snowfall is highly effective during the cold season. There are three automatic meteorology and snow observation stations and three stream gauge stations in the basin, which are operated especially for the calibration and validation of hydrological parameters at different altitudes and exposures. In this study, the parameters affecting snow accumulation–melting and runoff were investigated using the simulations on an hourly basis carried out over a three-year period for temporal and spatial distribution at the basin scale. Different from previous studies focusing on the rate of snowmelt, the temperature index method, which is calculated with physically-based parameters (R2 = 0.77~0.99), was integrated into the runoff simulations (R2 = 0.84) in the basin. The snowmelt-dominated basin is considered to be the source of the headwaters of the Euphrates River.

Size and shape variations in wing morphology of Anopheles maculipennis s.s. Meigen, 1818 (Diptera: Culicidae) from northeastern Turkey

Anopheles maculipennis Meigen, 1818 (Diptera: Culicidae) complex was discovered as the first sibling species complex among mosquito species and identified as a highly important malaria vector in the Middle East and Europe. Anopheles maculipennis s.s. is the nominotypical member species of the complex, and widely spread across the whole of Europe. Body size and shape are the most important characters of organisms and is related to numerous variables. Biological size and shape may be affected by altitude and altitudinal differences. In this study, the variation in wing size and shape of An. maculipennis s.s. populations collected from four sampling stations in Iğdır Province (Mürşitali, Sürmeli, Yukarıçıyrıklı and Zülfikarköy) and two sampling stations in Kars Province (Kötek and Kozlu) at different altitudes and in different habitats from northeastern Turkey in 2019 were investigated. It was assumed that altitude and the environmental differences related with altitude may affect the wing (body) size or shape of An. maculipennis s.s. This is the first comparative geometric morphometric study of An. maculipennis s.s. populations in Turkey and the results indicate size and shape differences among some populations. While centroid size did not show a linear association with altitude, samples from the highest altitude population had larger wings than the other populations.

Vascular epiphytes of the Serra do Relógio: the surprising richness of the seasonal forests in the mountains of Minas Gerais, Southeastern Brazil

Abstract Studies conducted on vascular epiphytes in Minas Gerais have revealed high richness in the seasonal semi-deciduous forests (SSF) in comparison with those of other Brazilian states. This study aimed to present a vascular epiphyte checklist of the Serra do Relógio (SR) in the Atlantic Forest of Minas Gerais, in order to analyze the similarity between two areas in different altitudes, as well as to discuss the high richness recorded for this synusia in the SSFs of this state. The survey was performed in two conservation units (CUs) apart from each other approximately 6 km and with elevations varying between ~500 and 1,434 m. The data were obtained from published articles and fieldwork performed between the years 2016 and 2019. We recorded 158 species distributed in 76 genera and 22 families. This richness is greater than those found in some ombrophilous forests, which was an unexpected result due to the high moisture of this phytophysionomy. Although approximately 66% of the species found in the SR are anemochoric and the compared CUs are geographically close, the similarity was only 22%, suggesting that the difference in altitude between the areas and the history of use can impose filters that influence the floristic composition of each one area. These results highlight the importance of preserving the forest remnants in Brazil and creating and maintain CUs to protect them.

Сравнительный эколого-географический анализ кузниц большого пёстрого дятла Dendrocopos major (Aves: Piciformes) на севере и юге европейской части России

Сравнительный эколого-географический анализ кузниц большого пёстрого дятла Dendrocopos major (Aves: Piciformes) на севере и юге европейской части России

祁连山北坡主要木本植物功能性状及其海拔分异

PDF HTML阅读 XML下载 导出引用 引用提醒 祁连山北坡主要木本植物功能性状及其海拔分异 DOI: 10.5846/stxb202110212974 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划（2019YFC0507405） The main woody plant functional traits and altitude differences on the northern slope of Qilian Mountains Author: Affiliation: Fund Project: National Key R&D Program of China（2019YFC0507405） 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:植物功能性状是植物对生境长期适应所形成的可测量特征，受植物遗传特性和环境因子的共同影响。祁连山是我国干旱区的一条重要山脉，北坡海拔介于2000-5000 m，分布着青海云杉、祁连圆柏等10余种木本植物。深入了解祁连山区木本植物功能性状随海拔梯度分异特征对认识山地植物的适应性和植被垂直地带分布具有重要意义。选取祁连山北坡天然分布的11种木本植物，其中灌木9种，分别是金露梅（Potentilla fruticosa）、银露梅（Potentilla glabra）、水栒子（Cotoneaster multiflorus）、猫儿刺（Ilex pernyi）、吉拉柳（Salix gilashanica）、鬼箭锦鸡儿（Caragana jubata）、刚毛忍冬（Lonicera hispida）、高山绣线菊（Spiraea alpina）和鲜黄小檗（Berberis diaphana），乔木2种，分别是青海云杉（Picea crassifolia）和祁连圆柏（Juniperus przewalskii），调查了木质密度、胡伯尔值、叶面积、叶干物质含量、叶含水率和比叶面积6个枝、叶功能性状。结果表明：（1）灌木的木质密度、胡伯尔值、叶含水率和比叶面积显著高于乔木，但叶面积和叶干物质含量显著低于乔木；（2）木质密度和叶干物质含量随海拔升高显著下降，其他功能性状沿海拔分异不显著；（3）生长季气温与叶干物质含量正相关，与胡伯尔值和叶含水率负相关，生长季降水与各功能性状相关关系不显著。说明乔木和灌木植物采取不同的枝、叶资源利用策略来适应高山生境；随海拔升高，降低结构性碳投资可能限制了高山植被的分布上限；生长季气温是引起性状沿海拔分异的重要环境因子，但不能完全解释性状沿海拔分异规律。 Abstract:Plant functional traits are the measurable characteristics of plants which are formed by long-term adaptation to habitat environmental conditions. The characterization of plant functional traits is mainly influenced by both the plants specific genetic basis and the shifted environmental factors. Qilian Mountains, with an elevation ranging from 2000 to 5000 m, is one of the major mountains in the dry land in Northwest China, where naturally distributed more than 10 kinds of woody plants such as Picea crassifolia and Juniperus przewalskii on the northern slope. It is of great academic and practice significance to understand the acclimation strategy and the vertical distribution pattern of alpine woody plants by deeply investigating the woody plant functional traits variation and the behind driving mechanism along with the altitude gradients in the Qilian Mountains. In the present study, we investigated 11 naturally distributed woody plant species along with the altitude in the Qilian Mountains, which included 9 shrub species (Potentilla fruticosa, Potentilla glabra, Cotoneaster multiflorus, Ilex pernyi, Salix gilashanica, Caragana jubata, Lonicera hispida, Spiraea alpine, and Berberis diaphana, respectively) and 2 tree species (Picea crassifolia and Juniperus przewalskii, respectively). A total of six plant functional traits of shoot and leaf were investigated in this study, and which include woody density, huber value, leaf area, leaf dry matter content, leaf water content, and specific leaf area, respectively. The results showed that:(1) woody density, huber value, leaf water content, and specific leaf area of shrub species were significantly greater than those of tree species, and leaf area and leaf dry matter content of shrub species were significantly lower than those of tree species. (2) Woody density and leaf dry matter content declined significantly along with the altitude gradients increased, and the other functional traits changed insignificantly along with the altitude gradients increased. (3) Growing-season air temperature was positively correlated with leaf dry matter content, and was negatively correlated with huber value and leaf water content; however, non-significant relationships between growing-season precipitation and plant functional traits were found. The results showed that tree and shrub plants adapted to the alpine habitats by adopting different branch and leaf resources utilization strategies; the decreasing structure carbon investment with the altitude gradients increased possibly has limited the upshift of alpine plants; the growing-season air temperature was one of the key environmental factors tuning woody plant functional traits variation pattern along with the altitudes gradients but could not explain all the variance. 参考文献 相似文献 引证文献

Variations in HIF-1α Contributed to High Altitude Hypoxia Adaptation via Affected Oxygen Metabolism in Tibetan Sheep.

Simple SummaryHypoxia-inducible factors (HIFs) play an important role in the adaptation of animals to high-altitude hypoxia. In high-altitude indigenous species, variation in the hypoxia-inducible factor-1 alpha (HIF-1α) gene has been reported in Tibetans, yaks and Tibetan horses, but has not been investigated in Tibetan sheep, and is not known if it might affect high-altitude hypoxia adaptation in these sheep. In this study, Kompetitive Allele-Specific PCR (KASP) was used for genotyping of ovine HIF-1α and investigated the effect of variation in HIF-1α on the high-altitude hypoxia adaptation of Tibetan sheep. The results suggest that ovine HIF-1α variants may promote the ability of oxygen utilization in Tibetan sheep and it may serve as a genetic marker for improving high-altitude hypoxia adaptability.The Tibetan sheep is an indigenous species of the Tibetan plateau and has been well adapted to high-altitude hypoxia. In comparison to lowland sheep breeds, the blood gas indicators have changed and the HIFs signaling pathway is activated in Tibetan sheep. These phenotypic and genetic alterations in Tibetan sheep are thought to be an important basis for adaptation to high-altitude hypoxia and variation in genes encoding the subunits that make up HIFs, such as HIF-1α can affect blood gas indicators. In this study, exons 9, 10, 12 of the HIF-1α gene were sequenced to find variations and 3 SNPs were detected, and these 3 SNPs were genotyped by KASP in 341 Hu sheep and 391 Tibetan sheep. In addition, 197 Hu sheep, 160 Tibetan sheep and 12 Gansu alpine merino sheep were used for blood gas indicators analysis. The results showed significant differences between the blood gas indicators of high-altitude breeds (Tibetan sheep and Gansu alpine merino sheep) and low-altitude breeds (Hu sheep), implying that the differences in blood gas indicators are mainly caused by differences in altitude. The haplotype combinations H2H3 and H1H3 were more frequent in the Tibetan sheep population, H2H3 increases O2 carrying capacity by increasing hematocrit and hemoglobin concentrations; H1H3 makes O2 dissociate more readily from oxyhemoglobin by decreasing partial pressure of oxygen and oxygen saturation. These results suggest that variants at the HIF-1α promote the ability of oxygen utilization in Tibetan sheep, which may underpin the survival and reproduction of Tibetan sheep on the Tibetan plateau.

Improving the tactical scanning of student pilots: A gaze-based training intervention for transition from visual flight into instrument meteorological conditions

Eye tracking has been applied to train novice drivers and clinicians; however, such applications in aviation are limited. This study develops a gaze-based intervention using video-based, expert commentary, and 3M (Mistake, Mitigation, Mastery) training to instruct visual flight rule student pilots on an instrument cross-check to mitigate the risk of losing aircraft control when they inadvertently enter instrument meteorological conditions (IMC). Twenty general aviation student pilots were randomized into control and experimental groups. Dwell time, return time, entropy, Kullback-Leibler divergence, and deviations from flight paths were compared before and after training to straight-and-level-flight (LF) and standard left level turn (LT) scenarios. After the training, the experimental pilots significantly increased dwell time on primary instruments (PIs), reduced randomness in visual search, and fixated on the PIs in shorter times (in the scenario of LT). In terms of piloting, all experimental pilots successfully kept the aircraft control while five control pilots lost control in IMC; significant differences in altitude and rate of climb deviations were observed between groups (in the scenario of LF).