Monitoring Army Radio-Communications Networks at High Altitude

1973 ◽  
Vol 37 (2) ◽  
pp. 471-476 ◽  
Author(s):  
Richard L. Cahoon

2 experiments were conducted to determine the effects of high altitude atmospheres on the performance of a simulated Army radio-communication task. Ss monitored 2-hr. tapes of simulated radio traffic at 4 different altitudes (sea level, 13,000 ft., 15,000 ft., and 17,000 ft.). The results of Exp. I indicated a significant drop in performance above 13,000 ft. altitude. However, Exp. II, using highly motivated, radio-trained Ss showed no performance decrements up to 17,000 ft. The data suggest that high motivation and training can compensate for altitude stress on monitoring tasks of relatively short duration.

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Carla Santos ◽  
Alcibíades Bustamante ◽  
Donald Hedeker ◽  
Olga Vasconcelos ◽  
Rui Garganta ◽  
...  

Background and Aim. Overweight prevalence in children and adolescents shows great variability which is related to individual-level and environmental-level factors. The present study aimed to determine the prevalence of and factors associated with overweight in Peruvian children and adolescents living at different altitudes. Methods. 8568 subjects, aged 6–16 y, from the sea level, Amazon, and high-altitude regions were sampled. Overweight was identified using BMI; biological maturation and physical fitness were measured; school characteristics were assessed via an objective audit. Results. Overweight prevalence decreased with age (28.3% at 6 y to 13.9% at 16 y); it was higher in girls (21.7%) than boys (19.8%) and was higher at the sea level (41.3%), compared with Amazon (18.8%) and high-altitude (6.3%) regions. Approximately 79% of the variance in overweight was explained by child-level characteristics. In Model 1, all child-level predictors were significant (p<0.001); in Model 2, six out of nine added school-level predictors (number of students, existence of policies and practices for physical activity, multisports-roofed, duration of Physical Education classes, and extracurricular activities) were significant (p<0.001); in Model 3, subjects living at high altitudes were less likely to be overweight than those living at the sea level. Conclusions. Child- and school-level variables played important roles in explaining overweight variation. This information should be taken into account when designing more efficient strategies to combat the overweight and obesity epidemic.


In this study were observed the effects of two widely differing environments on the growth and maturation of children from a presumed genetically homogeneous Ethiopian population. Major environmental differences included altitude above sea level, temperature, probably rainfall and humidity, together with the incidence of infectious disease. The results indicate that highland children, particularly boys, are taller, heavier and bigger in most physical dimensions than are lowland children. In both groups skeletal maturation is retarded (by American White standards) during later childhood; this retardation is more marked in lowlanders. In both groups, however, there is marked acceleration of skeletal maturation during early puberty. Haemoglobin values increase much more rapidly in highland children, but surprisingly, differences in chest dimensions are not particularly marked. It is concluded that hypoxia of the degree found in the high-altitude group (approximately 3000 m) is not sufficient to affect adversely the growth of children. On the other hand, the increased incidence of infectious disease in the ‘lowlands’ (approximately 1500 m) and possibly the raised ambient temperature, may restrict growth and maturation of children living in this environment. Thus, in contrast to the situation in other high-altitude parts of the world, the highlands in Ethiopia appear to be more favourable to growth than the lowlands.


2017 ◽  
Vol 4 (2) ◽  
Author(s):  
Capt(ex) Deepika Chamoli ◽  
Dr Rita Kumar ◽  
Prof. (Dr.) Abha Singh

The present study analyses the effect of meditation on locus of control of two groups(regular practitioners of meditation and non meditators) at two different altitudes (2535ft and 13500ft above sea level). The two groups comprised of Buddhist monks/Regular practitioners of meditation) and some locals in Yol Cantt (2535ft) and Lamayuru (13500ft). In the study it has been hypothesized that group one (Buddhist monks/Regular practitioners of meditation) at both the altitudes are inclined towards internal locus of control (internalism) whereas the second group is more inclined towards external locus of control (externalism). Total 100 individuals, 25 monks and 25 laymen from both areas were assessed by administering Rotter’s locus of control scale. Self-reported responses of the subjects were recorded, scored and subjected to ‘t’test analysis. It was established that group practicing regular meditation (monks) is more inclined towards internal locus of control. The study has suggested that the individual practicing meditation at both the altitudes have more inclination towards internal locus of control and non regular practitioner have also shown inclination towards internal locus of control at higher altitude. Subjects who are following some religious practices, creative art etc. also have more of internalism. Internalism is also more prevalent in high altitude.


Motricidade ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 12 ◽  
Author(s):  
Eduardo Borba Neves

The aim of this study was to investigate the Correlations between the Simulated Military Tasks Performance and Physical Fitness Tests at high altitude. This research is part of a project to modernize the physical fitness test of the Colombian Army. Data collection was performed at the 13th Battalion of Instruction and Training, located 30km south of Bogota D.C., with a temperature range from 1ºC to 23ºC during the study period, and at 3100m above sea level. The sample was composed by 60 volunteers from three different platoons. The volunteers start the data collection protocol after 2 weeks of acclimation at this altitude. The main results were the identification of a high positive correlation between the 3 Assault wall in succession and the Simulated Military Tasks performance (r = 0.764, p<0.001), and a moderate negative correlation between pull-ups and the Simulated Military Tasks performance (r = -0.535, p<0.001). It can be recommended the use of the 20-consecutive overtaking of the 3 Assault wall in succession as a good way to estimate the performance in operational tasks which involve: assault walls, network of wires, military Climbing Nets, Tarzan jump among others, at high altitude.


1998 ◽  
Vol 29 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Peter Raben ◽  
Wilfred H. Theakstone

Marked vertical variations of ions and oxygen isotopes were present in the snowpack at the glacier Austre Okstindbreen during the pre-melting phase in 1995 at sites between 825 m and 1,470 m above sea level. As the first meltwater percolated from the top of the pack, ions were moved to a greater depth, but the isotopic composition remained relatively unchanged. Ions continued to move downwards through the pack during the melting phase, even when there was little surface melting and no addition of liquid precipitation. The at-a-depth correlation between ionic concentrations and isotopic ratios, strong in the pre-melting phase, weakened during melting. In August, concentrations of Na+ and Mg2+ ions in the residual pack were low and vertical variations were slight; 18O enrichment had occurred. The difference of the time at which melting of the snowpack starts at different altitudes influences the input of ions and isotopes to the underlying glacier.


2020 ◽  
Vol 128 (1) ◽  
pp. 127-133 ◽  
Author(s):  
Owen. R. Vaughan ◽  
Fredrick Thompson ◽  
Ramón. A. Lorca ◽  
Colleen G. Julian ◽  
Theresa L. Powell ◽  
...  

Women residing at high altitudes deliver infants of lower birth weight than at sea level. Birth weight correlates with placental system A-mediated amino acid transport capacity, and severe environmental hypoxia reduces system A activity in isolated trophoblast and the mouse placenta. However, the effect of high altitude on human placental amino acid transport remains unknown. We hypothesized that microvillous membrane (MVM) system A and system L amino acid transporter activity is lower in placentas of women living at high altitude compared with low-altitude controls. Placentas were collected at term from healthy pregnant women residing at high altitude (HA; >2,500 m; n = 14) or low altitude (LA; <1,700 m; n = 14) following planned, unlabored cesarean section. Birth weight, but not placenta weight, was 13% lower in HA pregnancies (2.88 ± 0.11 kg) compared with LA (3.30 ± 0.07 kg, P < 0.01). MVM erythropoietin receptor abundance, determined by immunoblot, was greater in HA than in LA placentas, consistent with lower placental oxygen levels at HA. However, there was no effect of altitude on MVM system A or L activity, determined by Na+-dependent [14C]methylaminoisobutyric acid uptake and [3H]leucine uptake, respectively. MVM abundance of glucose transporters (GLUTs) 1 and 4 and basal membrane GLUT4 were also similar in LA and HA placentas. Low birth weights in the neonates of women residing at high altitude are not a consequence of reduced placental amino acid transport capacity. These observations are in general agreement with studies of IUGR babies at low altitude, in which MVM system A activity is downregulated only in growth-restricted babies with significant compromise. NEW & NOTEWORTHY Babies born at high altitude are smaller than at sea level. Birth weight is dependent on growth in utero and, in turn, placental nutrient transport. We determined amino acid transport capacity in placentas collected from women resident at low and high altitude. Altitude did not affect system A amino acid transport across the syncytiotrophoblast microvillous membrane, suggesting that impaired placental amino acid transport does not contribute to reduced birth weight in this high-altitude population.


1981 ◽  
Vol 25 (1) ◽  
pp. 47-52 ◽  
Author(s):  
S. C. Jain ◽  
Jaya Bardhan ◽  
Y. V. Swamy ◽  
A. Grover ◽  
H. S. Nayar

2018 ◽  
Vol 4 ◽  
pp. 48-53
Author(s):  
Ramesh Prasad Sah ◽  
Hari Kumar Prasai ◽  
Jiban Shrestha ◽  
Md Hasanuzzaman Talukder ◽  
AKM Anisur Rahman ◽  
...  

Buffalo is the most important livestock commodities for milk, meat production and several other multipurpose uses distributed densely from southern tarai to northern mid-hills in Nepal. Among several internal parasitic diseases fascioliasis is highly economic one caused by Fasciola in buffaloes. However, there are only few studies carried on prevalence of fascioliasis emphasizing buffaloes in relation to seasonal (summer and rainy, and winter) and altitudinal variations. Therefore, we examined prevalence of fascioliasis seasonally and vertically. For the purpose, we selected two districts of eastern Nepal and sampled from low altitude area known as Madhesha ranging from 175-200, Dhankuta from 800-1200 m, and Murtidhunga from 1800-2200 m elevation from the sea level, representing tarai, mid hills and high hills, respectively. Altogether from February 2013 to January 2014 at every two months interval we collected 798 fecal samples from buffaloes; 282 from Murtidhunga, 239 from Dhankuta and 277 from Madhesha. The samples were examined microscopically for the presence of Fasciola eggs using sedimentation technique. Results showed that overall prevalence of fascioliasis in buffaloes was 39.9% (319/798), ranging highest 42.6%in Madhesha followed by 39.7% in Murtidhunga and 37.2% in Dhankuta, respectively. The prevalence of fascioliasis was found to be significantly (p <0.05) high in winter (44.9%) comparing to rainy season (34.4%). The prevalence of fascioliasis in buffaloes was relatively higher in low altitude than high altitude, although it was not statistically significant (p <0.05). In our findings the female buffaloes showed higher prevalence for fascioliasis than in male. Since the fascioliasis in buffaloes is highly endemic, thus strategic deworming in high risk period is recommended along with measure to prevent pasture contamination with buffalo feces.


1963 ◽  
Vol 26 (4) ◽  
pp. 555-566 ◽  
Author(s):  
P. C. B. MACKINNON ◽  
M. E. MONK-JONES ◽  
K. FOTHERBY

SUMMARY 1. Four men and three women ascended by télépherique and helicopter from 1000 to 4333 m. where they remained for 23 days. 2. Measurements of urinary 17-hydroxycorticosteroids, 17-oxosteroids, pregnanediol and pregnanetriol and circulating eosinophils were made at sea level and at high altitude. 3. An attempt was also made to measure changes in emotional activity by means of the palmar sweat index (PSI). This index was assessed at intervals throughout the day at sea level and at high altitude, and in response to adrenocorticotrophic hormone (ACTH) and a self-imposed stress. 4. Within 24 hr. of acute exposure to high altitude urinary 17-hydroxycorticosteroids increased whilst circulating eosinophils decreased; by the 5th day both were returning to sea-level values. The output of 17-oxosteroids was lower by the 5th day at high altitude and subsequently increased; pregnanediol and pregnanetriol levels remained unchanged. 5. PSIs throughout the day become progressively lower as the length of stay at altitude increased. The response to ACTH at sea level and high altitude appeared to be similar but the response to a self-imposed stress was longer in duration at high altitude than at sea level.


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