نتایج جستجو برای: altitude

تعداد نتایج: 21619  

1999
Michael Papazoglou Jeffrey L. Krolik

In previous work, a matched-field estimate of aircraft altitude which uses multiple over-the-horizon radar dwells was presented. This approach exploited the altitude dependent structure of the micro-multipath rays which result from reflections local to the aircraft. While it was shown that the multi-dwell matched-field estimate is able to accurately estimate altitude while using typical radar p...

2009
Gina E. Adam Charles S. Fulco

Warfighter exposure to high terrestrial altitude continues to be a reality for the modern fighting force. Understanding the negative effects of altitude on cognitive performance is essential as the cognitive demands of many warfighting tasks are becoming increasingly complex. To date, little research has investigated the performance of multiple cognitive tasks in a high altitude environment. Th...

2015
Hailin Ma Yan Wang Jianhui Wu Ping Luo Buxin Han

To investigate the effects of high-altitude exposure on response inhibition, event-related potential (ERP) components N2 and P3 were measured in Go/NoGo task. The participants included an 'immigrant' high-altitude group (who had lived at high altitude for three years but born at low altitude) and a low-altitude group (living in low altitude only). Although the behavioural data showed no signifi...

Journal: :Journal of physiology and pharmacology : an official journal of the Polish Physiological Society 2007
G R Zubieta-Calleja P-E Paulev L Zubieta-Calleja G Zubieta-Castillo

Adaptation takes place not only when going to high altitude, as generally accepted, but also when going down to sea level. Immediately upon ascent to high altitude, the carotid body senses the lowering of the arterial oxygen partial pressure due to a diminished barometric pressure. High altitude adaptation is defined as having three stages: 1) acute, first 72 hours, where acute mountain sicknes...

2013
Eunsuk Kim Kathleen Donohue

1. Alpine plants are at high risk because of climate change. Assessing the performance of alpine plant species across different altitudes is useful for predicting how they may respond to changing climate. Adaptation and plasticity of early life stages are of particular interest since seed germination and seedling establishment could be crucial life-history stages for environmental tracking and ...

Introduction: High altitude destinations are popular among international travelers. Travel medicine practitioners should be familiar with altitude physiology and high altitude illness recognition, prophylaxis, and management. We performed the first bibliometric analysis of high altitude medicine research. Methods: All articles published in a specialist hi...

Journal: :American journal of physical anthropology 1999
A R Frisancho P C Juliao V Barcelona C E Kudyba G Amayo G Davenport A Knowles D Sanchez M Villena E Vargas R Soria

This paper evaluates the age-associated changes of resting ventilation of 115 high- and low-altitude Aymara subjects, of whom 61 were from the rural Aymara village of Ventilla situated at an average altitude of 4,200 m and 54 from the rural village of Caranavi situated at an average altitude of 900 m. Comparison of the age patterns of resting ventilation suggests the following conclusions: 1) t...

Journal: :American journal of physical anthropology 1995
A R Frisancho H G Frisancho M Milotich T Brutsaert R Albalak H Spielvogel M Villena E Vargas R Soria

The aerobic capacity of 268 subjects (158 males and 110 females) was evaluated in La Paz, Bolivia situated at 3,750 m. The sample included 1) 39 high altitude rural natives (all male); 2) 67 high altitude urban natives (32 male, 35 female); 3) 69 Bolivians of foreign ancestry acclimatized to high altitude since birth (37 male, 32 female); 4) 50 Bolivians of foreign ancestry acclimatized to high...

2013
Sarah Eisen Louise Pealing Robert W. Aldridge Mark J. Siedner Alejandro Necochea Inna Leybell Teresa Valencia Beatriz Herrera Siouxsie Wiles Jon S. Friedland Robert H. Gilman Carlton A. Evans

BACKGROUND Tuberculosis infection, disease and mortality are all less common at high than low altitude and ascent to high altitude was historically recommended for treatment. The immunological and mycobacterial mechanisms underlying the association between altitude and tuberculosis are unclear. We studied the effects of altitude on mycobacteria and antimycobacterial immunity. METHODS Antimyco...

Journal: :iranian journal of allergy, asthma and immunology 0
vahid ziaee reza alizadeh ali movafegh

hypoxia and hypocapnia can cause broncho-constriction in human subjects, and this could have a bearing on performance at high altitude. the object of this study was to examine how pulmonary ventilatory functions during high-altitude trekking. this study is a cohort study on spirometric parameters at different altitudes. fifty six healthy male volunteers from a university student population were...

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