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high altitude adaptation strategies

Yongzheng Xu, Guizhen Yu, Yunpeng Wang, Xinkai Wu, Yalong Ma
A new hybrid vehicle detection scheme which integrates the Viola-Jones (V-J) and linear SVM classifier with HOG feature (HOG + SVM) methods is proposed for vehicle detection from low-altitude unmanned aerial vehicle (UAV) images. As both V-J and HOG + SVM are sensitive to on-road vehicles' in-plane rotation, the proposed scheme first adopts a roadway orientation adjustment method, which rotates each UAV image to align the roads with the horizontal direction so the original V-J or HOG + SVM method can be directly applied to achieve fast detection and high accuracy...
2016: Sensors
Anna Bogdanova, Irina Y Petrushanko, Pablo Hernansanz-Agustín, Antonio Martínez-Ruiz
Control over the Na,K-ATPase function plays a central role in adaptation of the organisms to hypoxic and anoxic conditions. As the enzyme itself does not possess O2 binding sites its "oxygen-sensitivity" is mediated by a variety of redox-sensitive modifications including S-glutathionylation, S-nitrosylation, and redox-sensitive phosphorylation. This is an overview of the current knowledge on the plethora of molecular mechanisms tuning the activity of the ATP-consuming Na,K-ATPase to the cellular metabolic activity...
2016: Frontiers in Physiology
Andy M Reynolds, Don R Reynolds, Sanjay P Sane, Gao Hu, Jason W Chapman
High-flying insect migrants have been shown to display sophisticated flight orientations that can, for example, maximize distance travelled by exploiting tailwinds, and reduce drift from seasonally optimal directions. Here, we provide a comprehensive overview of the theoretical and empirical evidence for the mechanisms underlying the selection and maintenance of the observed flight headings, and the detection of wind direction and speed, for insects flying hundreds of metres above the ground. Different mechanisms may be used-visual perception of the apparent ground movement or mechanosensory cues maintained by intrinsic features of the wind-depending on circumstances (e...
September 26, 2016: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
Louise Brousseau, Dragos Postolache, Martin Lascoux, Andreas D Drouzas, Thomas Källman, Cristina Leonarduzzi, Sascha Liepelt, Andrea Piotti, Flaviu Popescu, Anna M Roschanski, Peter Zhelev, Bruno Fady, Giovanni Giuseppe Vendramin
BACKGROUND: Local adaptation is a key driver of phenotypic and genetic divergence at loci responsible for adaptive traits variations in forest tree populations. Its experimental assessment requires rigorous sampling strategies such as those involving population pairs replicated across broad spatial scales. METHODS: A hierarchical Bayesian model of selection (HBM) that explicitly considers both the replication of the environmental contrast and the hierarchical genetic structure among replicated study sites is introduced...
2016: PloS One
Deborah S Vidigal, Alexandre C S S Marques, Leo A J Willems, Gonda Buijs, Belén Méndez-Vigo, Henk W M Hilhorst, Leónie Bentsink, F Xavier Picó, Carlos Alonso-Blanco
The temporal control or timing of the life cycle of annual plants is presumed to provide adaptive strategies to escape harsh environments for survival and reproduction. This is mainly determined by the timing of germination, which is controlled by the level of seed dormancy, and of flowering initiation. However, the environmental factors driving the evolution of plant life cycles remain largely unknown. To address this question we have analysed nine quantitative life history traits, in a native regional collection of 300 wild accessions of Arabidopsis thaliana...
August 2016: Plant, Cell & Environment
Claudia Cocozza, Caterina Palombo, Roberto Tognetti, Nicola La Porta, Monica Anichini, Alessio Giovannelli, Giovanni Emiliani
Seasonal analyses of cambial cell production and day-by-day stem radial increment can help to elucidate how climate modulates wood formation in conifers. Intra-annual dynamics of wood formation were determined with microcores and dendrometers and related to climatic signals in Norway spruce (Picea abies (L.) Karst.). The seasonal dynamics of these processes were observed at two sites of different altitude, Savignano (650 m a.s.l.) and Lavazè (1800 m a.s.l.) in the Italian Alps. Seasonal dynamics of cambial activity were found to be site specific, indicating that the phenology of cambial cell production is highly variable and plastic with altitude...
July 2016: Tree Physiology
José López-Barneo, Patricia Ortega-Sáenz, Patricia González-Rodríguez, M Carmen Fernández-Agüera, David Macías, Ricardo Pardal, Lin Gao
Acute O2 sensing is necessary for the activation of cardiorespiratory reflexes (hyperventilation and sympathetic activation), which permit the survival of individuals under hypoxic environments (e.g. high altitude) or medical conditions presenting with reduced capacity for gas exchange between the lung alveoli and the blood. Changes in blood O2 tension are detected by the arterial chemoreceptors, in particular the carotid body (CB), which act in concert with the adrenal medulla (AM) to facilitate rapid adaptations to hypoxia...
February 2016: Molecular Aspects of Medicine
J Gomez-Ezeiza, C Granados, J Santos-Concejero
AIM: The aim of this case study was to compare the competition approaches for the Race Walking World Cup and the Olympic Games of a world-class 50-km racewalker. METHOD: Total training volumes, intensity distribution, performance tests, high altitude stages and the evolution of his haematological values during the season were analysed. The last 12 weeks before the Race Walking World Cup (Approach 1) and the Olympic Games (Approach 2) were used for data analysis...
December 16, 2015: Journal of Sports Medicine and Physical Fitness
L I Guo, Jihang Zhang, Jun Jin, Xubin Gao, Jie Yu, Qianwen Geng, Huijie Li, Lan Huang
The endothelial PAS domain protein 1 (EPAS1) gene functions to sense the blood oxygen level by regulating the hypoxia-inducible transcription factor pathway, and single nucleotide polymorphisms (SNPs) of EPAS1 have been found to have a strong and positive selection in the adaptation of the native Tibetan highland population to high-altitude hypoxia. The aim of the present study was to investigate the effect of EPAS1 SNPs on the risk of acute mountain sickness (AMS) and the physiological responses to acute high-altitude hypoxia in lowland humans...
September 2015: Experimental and Therapeutic Medicine
Mauricio Canals, Claudio Veloso, Rigoberto Solís
Spiders are small arthropods that have colonized terrestrial environments. These impose three main problems: (i) terrestrial habitats have large fluctuations in temperature and humidity; (ii) the internal concentration of water is higher than the external environment in spiders, which exposes them continually to water loss; and (iii) their small body size determines a large surface/volume ratio, affecting energy exchange and influencing the life strategy. In this review we focus on body design, energetic, thermal selection, and water balance characteristics of some spider species present in Chile and correlate our results with ecological and behavioral information...
2015: Frontiers in Physiology
Xiangwei Bu, Xiaoyan Wu, Mingyan Tian, Jiaqi Huang, Rui Zhang, Zhen Ma
In this paper, an adaptive neural controller is exploited for a constrained flexible air-breathing hypersonic vehicle (FAHV) based on high-order tracking differentiator (HTD). By utilizing functional decomposition methodology, the dynamic model is reasonably decomposed into the respective velocity subsystem and altitude subsystem. For the velocity subsystem, a dynamic inversion based neural controller is constructed. By introducing the HTD to adaptively estimate the newly defined states generated in the process of model transformation, a novel neural based altitude controller that is quite simpler than the ones derived from back-stepping is addressed based on the normal output-feedback form instead of the strict-feedback formulation...
September 2015: ISA Transactions
Aurélien Pichon, Nicolas Voituron, Zhenzhong Bai, Florine Jeton, Wuren Tana, Dominique Marchant, Guoen Jin, Jean-Paul Richalet, Ri-Li Ge
The objective of this study was to compare the different ventilatory strategies that help in coping with hypoxic-hypercapnia environment among two species: use acclimated rats and plateau pikas (Ochotona curzoniae) that live in Tibetan plateaus, and have been well adjusted to high altitude. Arterial blood samples taken at 4100 m of elevation in acclimatized rats and adapted pikas revealed inter-species differences with lower hemoglobin and hematocrit and higher blood pH in pikas. A linear and significant increase in minute ventilation was observed in pikas, which help them to cope with hypoxic-hypercapnia...
September 2015: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
S Mohajeri, B A Perkins, P L Brubaker, M C Riddell
Although regular physical activity is encouraged for individuals with diabetes, exercise at high altitude increases risk for a number of potential complications. This review highlights our current understanding of the key physiological and clinical issues that accompany high-altitude travel and proposes basic clinical strategies to help overcome obstacles faced by trekkers with Type 1 or Type 2 diabetes. Although individuals with diabetes have adaptations to the hypoxia of high altitude (increased ventilation, heart rate, blood pressure and hormonal responses), elevated counter-regulatory hormones can impair glycaemic control, particularly if mountain sickness occurs...
November 2015: Diabetic Medicine: a Journal of the British Diabetic Association
Bruno Leles, Anderson V Chaves, Philip Russo, João A N Batista, Maria Bernadete Lovato
Knowledge of the role of Neotropical montane landscapes in shaping genetic connectivity and local adaptation is essential for understanding the evolutionary processes that have shaped the extraordinary species diversity in these regions. In the present study, we examined the landscape genetics, estimated genetic diversity, and explored genetic relationships with morphological variability and reproductive strategies in seven natural populations of Cattleya liliputana (Orchidaceae). Nuclear microsatellite markers were used for genetic analyses...
2015: PloS One
V V Voĭnov, E V Verbitskiĭ
The primary reason of neocortex electrogenesis alteration in high-altitude adaptation at the altitude 3000-5600 m above sea level according to the EEG parameters of the night sleep and wakefulness is brain noncompensated superficial hypoxia. The situation becomes worse at the night by reason of apnoe/hypopnoe effects which occur because of muscular atony during slow sleep fall. The compensation these disorders at the expense of hypertensive and cardiorespiratory responses are identified by general mechanisms and individual strategy...
November 2014: Fiziologiia Cheloveka
Jason W Chapman, Don R Reynolds, Kenneth Wilson
Myriad tiny insect species take to the air to engage in windborne migration, but entomology also has its 'charismatic megafauna' of butterflies, large moths, dragonflies and locusts. The spectacular migrations of large day-flying insects have long fascinated humankind, and since the advent of radar entomology much has been revealed about high-altitude night-time insect migrations. Over the last decade, there have been significant advances in insect migration research, which we review here. In particular, we highlight: (1) notable improvements in our understanding of lepidopteran navigation strategies, including the hitherto unsuspected capabilities of high-altitude migrants to select favourable winds and orientate adaptively, (2) progress in unravelling the neuronal mechanisms underlying sun compass orientation and in identifying the genetic complex underpinning key traits associated with migration behaviour and performance in the monarch butterfly, and (3) improvements in our knowledge of the multifaceted interactions between disease agents and insect migrants, in terms of direct effects on migration success and pathogen spread, and indirect effects on the evolution of migratory systems...
March 2015: Ecology Letters
Lan Ma, Liming Yang, Jingjie Zhao, Jingjing Wei, Xiangxiang Kong, Chuntao Wang, Xiaoming Zhang, Yongping Yang, Xiangyang Hu
We found the novel role of hydrogen sulfide in the adaptation of the alpine plant to altitude gradient in the Northern Tibetan Plateau. Alpine plants have developed strategies to survive the extremely cold conditions prevailing at high altitudes; however, the mechanism underlying the evolution of these strategies remains unknown. Hydrogen sulfide (H2S) is an essential messenger that enhances plant tolerance to environmental stress; however, its role in alpine plant adaptation to environmental stress has not been reported until now...
April 2015: Planta
Chung-Yu Chen, Chien-Wen Hou, Jeffrey R Bernard, Chiu-Chou Chen, Ta-Cheng Hung, Lu-Ling Cheng, Yi-Hung Liao, Chia-Hua Kuo
High altitude training is a widely used strategy for improving aerobic exercise performance. Both Rhodiola crenulata (R) and Cordyceps sinensis (C) supplements have been reported to improve exercise performance. However, it is not clear whether the provision of R and C during high altitude training could further enhance aerobic endurance capacity. In this study, we examined the effect of R and C based supplementation on aerobic exercise capacity following 2-week high altitude training. Alterations to autonomic nervous system activity, circulatory hormonal, and hematological profiles were investigated...
September 2014: High Altitude Medicine & Biology
Lise Comte, Jérôme Murienne, Gaël Grenouillet
Understanding climate-induced range shifts is crucial for biodiversity conservation. However, no general consensus has so far emerged about the mechanisms involved and the role of phylogeny in shaping species responses has been poorly explored. Here, we investigate whether species traits and their underlying phylogenetic constraints explain altitudinal shifts at the trailing and leading edges of stream fish species ranges. We demonstrate that these shifts are related to dissimilar mechanisms: whereas range retractions show some support for phylogenetic clustering due to a high level of conservatism in thermal safety margins, range expansions are underpinned by both evolutionarily conserved and labile traits, notably trophic position and life-history strategy, hence decreasing the strength of phylogenetic signal...
2014: Nature Communications
Lan Ma, Xudong Sun, Xiangxiang Kong, Jose Valero Galvan, Xiong Li, Shihai Yang, Yunqiang Yang, Yongping Yang, Xiangyang Hu
UNLABELLED: This study presents an analysis of leave and rood morphology, biochemical and proteomics approach as adaptation strategies of the alpine plant Potentilla saundersiana in an altitude gradient. Several plant physiological parameter, including root and leaf architecture, leaf photosynthesis capacity, specific leaf area (SLA) and leaf nitrogen concentration, histology and microscopy, anthocyanin and proline contents, antioxidant enzyme activity assay, in-gel enzyme activity staining, H2O2 and O2(-) content, immunoblotting, auxin and strigolactone content and proteomics analysis were evaluated at five different altitudes...
January 1, 2015: Journal of Proteomics
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