High altitude training is regarded as an integral component of modern athletic preparation, especially for endurance sports such as middle and long distance running. It has rapidly achieved popularity among elite endurance athletes and their coaches. Increased hypoxic stress at altitude facilitates key physiological adaptations within the athlete, which in turn may lead to improvements in sea-level athletic performance. Despite much research in this area to date, the exact mechanisms which underlie such improvements remain to be fully elucidated. This review describes the current understanding of physiological adaptation to high altitude training and its implications for athletic performance. It also discusses the rationale and main effects of different training models currently employed to maximise performance. Athletes who travel to altitude for training purposes are at risk of suffering the detrimental effects of altitude. Altitude illness, weight loss, immune suppression and sleep disturbance may serve to limit athletic performance. This review provides an overview of potential problems which an athlete may experience at altitude, and offers specific training recommendations so that these detrimental effects are minimised.
The purpose of the investigation was to study the early spring plant diversity distributed in different vegetation types and their life forms, in relation to different altitudes. The investigation was carried out in accordance with itinerary method beginning from the shoreline up to the mountain. The results showed that 100% of the totally collected plants from the desert vegetation were therophytes; 100% from steppe vegetation were geophytes; 50 from forest were geophytes and the other 50% were hemicryptophytes. It is concluded that the life forms of early spring plants change depending on the altitude corresponding to changes in the air temperature as well as climatic and edaphic factors.
Conventional and license-free radio-controlled drone activities are limited to a line-of-sight (LoS) operational range. One of the alternatives to operate the drones beyond the visual line-of-sight (BVLoS) range is replacing the drone wireless communications system from the conventional industrial, scientific, and medical (ISM) radio band to a licensed cellular-connected system. The Long Term Evolution (LTE) technology that has been established for the terrestrial area allows command-and-control and payload communications between drone and ground station in real-time. However, with increasing height above the ground, the radio environment changes, and utilizing terrestrial cellular networks for drone communications may face new challenges. In this regard, this paper aims to develop an LTE-based control system prototype for low altitude small drones and investigate the feasibility and performance of drone cellular connectivity at different altitudes with measuring parameters such as latency, handover, and signal strength. The measurement results have shown that by increasing flight height from ground to 170 m the received signal power and the signal quality levels were reduced by 20 dBm and 10 dB respectively, the downlink data rate decreased to 70%, and latency increased up to 94 ms. It is concluded that although the existing LTE network can provide a minimum requirement for drone cellular connectivity, further improvements are still needed to enhance aerial coverage, eliminate interference, and reduce network latency.
Normally, topographic map is produced using aerial photogrammetry. The recent development in aerial photogrammetry is the use of large format digital aerial camera for producing topographic map, however, the cost of the camera is too expensive and many mapping organization around the world could not afford to purchase it. In certain application, there is a need to map small area with limited budget. This issue has been solved by using small format camera (i.e. conventional or digital) to produce digital map. This study concentrates on the use of unmanned aerial vehicle (UAV) for producing digital map. UAV has been widely used in military for reconnaissance, planning, combat, and etc. Today, UAV can be used by civilian for reconnaissance, monitoring, mapping, and others. The objectives of this study are to investigate the capability of UAV in producing digital map and assess the accuracy of mapping using UAV. In this study, a light weight fixed wing UAV was used as a platform and a high resolution digital camera was used to acquire aerial digital images of the study area. The aerial digital images were acquired at low altitude. After capturing the aerial digital images, ground control points and check points were established using GPS. Then the aerial digital images were processed using photogrammetric software. The output of the study is a digital map and digital orthophoto. For accuracy assessment, the root mean square error (RMSE) is used. Based on the assessment, the results showed that accuracy of sub-meter can be obtained using the procedure and method used in the study. In conclusion, this study shows that UAV can be used for producing digital map at sub-meter accuracy and it can also be used for diversified applications.
This research focuses on the ASTER DEM generation for visual and mathematical analysis of topography, landscapes and landforms, as well as modeling of surface processes of Central Alborz, Iran. ASTER DEM 15 m generated using tie points over the Central Alborz and Damavand volcano with 5671 m height from ASTER (Advanced Space borne Thermal Emission and Reflection Radiometer) satellite data using PCI Geomatica 9.1. Geomorphic parameters are useful to identify and describe geomorphologic forms and processes, which were extracted from ASTER DEM in GIS environment such as elevation, aspect, slope angle, vertical curvature, and tangential curvature. Although the elevation values are slightly low in altitudes above 5500 m asl., the ASTER DEM is useful in interpretation of the macro- and meso-relief, and provides the opportunity for mapping especially at medium scales (1:100,000 and 1:50,000). ASTER DEM has potential to be a best tool to study 3D model for to geomorphologic mapping and processes of glacial and per glacial forms above 4300 m asl.
In recent years, there has been an increasing interest in quadcopter technology
implementation in the real world; for instance in real estate photography, aerial surveying, periodic
forest monitoring, and search/rescue missions. Generally, each quadcopter implementation required
different sensors which are needed to attach and integrate into quadcopter system. However, the most
critical part in almost cases is preparing the quadcopter flight performance and capability to be suited
in any outdoor applications. Because of that reason, this paper has proposed an implementation of
Open-Source Project (OSPs) platform as autonomous Unmanned Aerial Vehicle (UAV) quadcopter
development that can be fitted for any outdoor applications or even in research experimental purposes.
We started out with an explanation about the general approach that has been used in the development
of a quadcopter testbed, and then followed with detail explanations in the OSP platform approach.
The OSP platform is the most popular approach. The main reason is because of their flexibility in both
hardware and software. The basic quadcopter configuration for autonomous flight also presented and
applied. This paper also provided several outdoor experiments results in uncontrolled environment
that have been executed using our developed testbed to evaluate their performance, such as attitude
and altitude stabilization, interference and vibration effect, and trajectory mapping generation.
Finally, throughout this project, we realized that the OPSs quadcopter platform has offered almost
complete frameworks in the development of quadcopter for any outdoor applications or even as a
research testbed system.
In this paper, the efficient 3D placement of UAV as an aerial base station in providing wireless coverage for users in a small and large coverage area is investigated. In the case of providing wireless coverage for outdoor and indoor users in a small area, the Particle Swarm Optimization (PSO) and K-means with Ternary Search (KTS) algorithms are invoked to find an efficient 3D location of a single UAV with the objective of minimizing its required transmit power. It was observed that a single UAV at the 3D location found using the PSO algorithm requires less transmit power, by a factor of 1/5 compared to that when using the KTS algorithm. In the case of providing wireless coverage for users in three different shapes of a large coverage area, namely square, rectangle and circular regions, the problems of finding an efficient placement of multiple UAVs equipped with a directional antenna are formulated with the objective to maximize the coverage area and coverage density using the Circle Packing Theory (CPT). Then, the UAV efficient altitude placement is formulated with the objective of minimizing its required transmit power. It is observed that the large number of UAVs does not necessarily result in the maximum coverage density. Based on the simulation results, the deployment of 16, 19 and 26 UAVs is capable of providing the maximum coverage density of 78.5%, 82.5% and 80.3% for the case of a square region with the dimensions of 2 km × 2 km, a rectangle region with the dimensions of 6 km × 1.8 km and a circular region with the radius of 1.125 km, respectively. These observations are obtained when the UAVs are located at the optimum altitude, where the required transmit power for each UAV is reasonably small.
Biodiversity research relies largely on knowledge about species responses to environmental gradients, assessed using some commonly applied sampling method. However, the consistency of detected responses using different sampling methods, and thus the generality of findings, has seldom been assessed in tropical ecosystems. Hence, we studied the response consistency and indicator functioning of beetle assemblages in altitudinal gradients from two mountains in Malaysia, using Malaise, light, and pitfall traps. The data were analyzed using generalized linear mixed-effects models (GLMM), non-metric multidimensional scaling (NMDS), multivariate regression trees (MRT), and indicator species analysis (IndVal). We collected 198 morpho-species of beetles representing 32 families, with a total number of 3,052 individual beetles. The richness measures generally declined with increasing altitude. The mountains differed little in terms of light and Malaise trap data but differed remarkably in pitfall-trap data. Only light traps (but not the other trap types) distinguished high from middle or low altitudes in terms of beetle richness and assemblage composition. The lower altitudes hosted about twice as many indicators as middle or high altitudes, and many species were trap-type specific in our data. These results suggest that the three sampling methods reflected the altitudinal gradient in different ways and the detection of community variation in the environment thus depends on the chosen sampling method. However, also the analytical approach appeared important, further underlining the need to use multiple methods in environmental assessments.
Invertebrates such as termites feeding on nutrient-poor substrate receive essential nitrogen by biological nitrogen fixation of gut diazotrophs. However, the diversity and composition of gut diazotrophs of vertebrates such as Plateau pikas living in nutrient-poor Qinghai-Tibet Plateau remain unknown. To fill this knowledge gap, we studied gut diazotrophs of Plateau pikas (Ochotona curzoniae) and its related species, Daurian pikas (Ochotona daurica), Hares (Lepus europaeus) and Rabbits (Oryctolagus cuniculus) by high-throughput amplicon sequencing methods. We analyzed whether the gut diazotrophs of Plateau pikas are affected by season, altitude, and species, and explored the relationship between gut diazotrophs and whole gut microbiomes. Our study showed that Firmicutes, Spirochaetes, and Euryarchaeota were the dominant gut diazotrophs of Plateau pikas. The beta diversity of gut diazotrophs of Plateau pikas was significantly different from the other three lagomorphs, but the alpha diversity did not show a significant difference among the four lagomorphs. The gut diazotrophs of Plateau pikas were the most similarly to that of Rabbits, followed by Daurian pikas and Hares, which was inconsistent with gut microbiomes or animal phylogeny. The dominant gut diazotrophs of the four lagomorphs may reflect their living environment and dietary habits. Season significantly affected the alpha diversity and abundance of dominant gut diazotrophs. Altitude had no significant effect on the gut diazotrophs of Plateau pikas. In addition, the congruence between gut microbiomes and gut diazotrophs was low. Our results proved that the gut of Plateau pikas was rich in gut diazotrophs, which is of great significance for the study of ecology and evolution of lagomorphs.
Altitude training is sometimes employed by elite endurance athletes to improve their sea level performance. This improvement results from the increased red cell mass consequent upon the boost in erythropoietin (EPO) level that occurs as a response to the relatively hypoxic environment at high altitudes. We measured serum EPO levels together with various red cell and reticulocyte parameters including immature reticulocyte fraction (IRF) in eight national track-endurance cyclists, resident at sea-level, prior to and upon return from an altitude of approximately 1905 m. Reticulocytes and soluble transferrin receptor (sTfR) were significantly increased with reduction in ferritin levels immediately on return from high altitude indicating increased erythropoietic activity. IRF in particular showed a significant peak immediately on return but decline to sub-baseline levels by day 9, and recovery to baseline by day 16. Our results indicate that IRF is a sensitive marker of erythropoietic status in athletes undergoing altitude training and subsequent loss of EPO stimuli on return to sea level.
This is the first study on the seasonal biodiversity of black flies and evaluation of ecological factors influencing their distribution at Doi Pha Hom Pok National Park, northern Thailand. Larvae were collected from six fixed-stream sites in relation to altitude gradients from May 2011 to April 2013. The water temperature, water pH, conductivity, total dissolved solids (TDS), salt, water velocity, stream width and depth, streambed particle sizes, riparian vegetation, and canopy cover were recorded from each site. Monthly collections from the six sites yielded 5475 last-instar larvae, belonging to 29 black fly species. The most frequently found species from all sites were Simulium asakoae (100%) followed by Simulium yuphae (83.3%), and Simulium chiangdaoense, Simulium gombakense, Simulium phahompokense, Simulium fruticosum, Simulium maeaiense and Simulium fenestratum (66.6%). Of the 5475 last-instar larvae, S. maeaiense (19.3%), S. chiangdaoense (15.8%) and S. asakoae (14.8%), were the three most abundant species. The Shannon diversity index (H) at the six sites with different altitudes of 2100m, 2000m, 1500m, 1400m, 700m, and 500m above mean sea level, were 2.042, 1.832, 2.158, 2.123, 1.821 and 1.822, respectively. The Shannon index and number of taxa in the cold season were higher than those in the rainy and hot seasons. Principal component analysis (PCA) indicated that at least three principal components have eigen values >1.0 and accounted for 93.5% of the total variability of ecological factors among sampling sites. The Canonical correspondence analyses (CCA) showed that most species had a trend towards altitude, canopy cover, riparian vegetation and water velocity.
AbstractOrganisms living at high elevations generally grow and develop more slowly than those at lower elevations. Slow montane ontogeny is thought to be an evolved adaptation to harsh environments that improves juvenile quality via physiological trade-offs. However, slower montane ontogeny may also reflect proximate influences of harsh weather on parental care and offspring development. We experimentally heated and protected nests from rain to ameliorate harsh montane weather conditions for mountain blackeyes (Chlorocharis emiliae), a montane songbird living at approximately 3,200 m asl in Malaysian Borneo. This experiment was designed to test whether cold and wet montane conditions contribute to parental care and postnatal growth and development rates at high elevations. We found that parents increased provisioning and reduced time spent warming offspring, which grew faster and departed the nest earlier compared with offspring from unmanipulated nests. Earlier departure reduces time-dependent predation risk, benefitting parents and offspring. These plastic responses highlight the importance of proximate weather contributions to broad patterns of montane ontogeny and parental care.
Acute mountain sickness is an illness caused by climbing to a high altitude without prior acclimatization. Neurological consequences, like parkinsonism following acute mountain sickness without lesion of brain MRI have been reported rarely. A healthy 56-year-old man presented with dysarthria and gait disturbance. Neurological examination revealed tremor of hands, limb rigidity, and bradykinesia. The symptoms developed approximately 30 days following a 3,500 m climb of the Annapurna in the Himalayas. Brain MRI did not reveal any abnormalities including globus pallidus. The parkinsonism symptoms persisted for about 3 months before a complete recovered was made. We suggest that parkinsonism can develop after climbing to a high altitude but that the symptoms can be transient if a brain MRI detects no abnormalities.
The data reported in this paper are among the first relating to the microbiology of hyper-arid, very high altitude deserts and they provide base line information on the structure of actinobacterial communities. The high mountain Cerro Chajnantor landscape of the Central Andes in northern Chile is exposed to the world's most intense levels of solar radiation and its impoverished soils are severely desiccated. The purpose of this research was to define the actinobacterial community structures in soils at altitudes ranging from 3000 to 5000 m above sea level. Pyrosequencing surveys have revealed an extraordinary degree of microbial dark matter at these elevations that includes novel candidate actinobacterial classes, orders and families. Ultraviolet-B irradiance and a range of edaphic factors were found to be highly significant in determining community compositions at family and genus levels of diversity.
We genotyped 738 individuals belonging to 49 populations from Nepal, Bhutan, North India, or Tibet at over 500,000 SNPs, and analyzed the genotypes in the context of available worldwide population data in order to investigate the demographic history of the region and the genetic adaptations to the harsh environment. The Himalayan populations resembled other South and East Asians, but in addition displayed their own specific ancestral component and showed strong population structure and genetic drift. We also found evidence for multiple admixture events involving Himalayan populations and South/East Asians between 200 and 2,000 years ago. In comparisons with available ancient genomes, the Himalayans, like other East and South Asian populations, showed similar genetic affinity to Eurasian hunter-gatherers (a 24,000-year-old Upper Palaeolithic Siberian), and the related Bronze Age Yamnaya. The high-altitude Himalayan populations all shared a specific ancestral component, suggesting that genetic adaptation to life at high altitude originated only once in this region and subsequently spread. Combining four approaches to identifying specific positively selected loci, we confirmed that the strongest signals of high-altitude adaptation were located near the Endothelial PAS domain-containing protein 1 and Egl-9 Family Hypoxia Inducible Factor 1 loci, and discovered eight additional robust signals of high-altitude adaptation, five of which have strong biological functional links to such adaptation. In conclusion, the demographic history of Himalayan populations is complex, with strong local differentiation, reflecting both genetic and cultural factors; these populations also display evidence of multiple genetic adaptations to high-altitude environments.