scholarly journals Characterization of EPO H131S as a Key Mutation Site in the Hypoxia-adaptive Evolution of Gymnocypris Dobula

2021 ◽  
Author(s):  
Congcong Wang ◽  
Qin Zhang ◽  
Yang Liu ◽  
Qianghua Xu
Keyword(s):  
High Altitude ◽  
Glycoprotein Hormone ◽  
Mutation Site ◽  
Hypoxic Conditions ◽  
Hypoxic Environment ◽  
Hypoxia Adaptation ◽  
Low Altitude ◽  
Cellular Immune ◽  
Schizothoracine Fish

Abstract Erythropoietin (EPO) is a glycoprotein hormone involved in proerythropoiesis, antioxidation and antiapoptosis. It also contributes to cellular immune function in high-altitude species, such as the schizothoracine fish Gymnocypris dobula (G. dobula). Six mutation sites previously identified in EPO from G. dobula (GD-EPO) were injected into zebrafish embryos and their effects were compared with EPO from the low-altitude schizothoracine Schizothorax prenanti (S. prenanti). The key mutation site in GD-EPO was identified as H131S. Under hypoxic conditions, the levels of superoxide dismutase and malondialdehyde were decreased, whereas that of nitric oxide was increased in zebrafish injected with GD-EPO compared with those injected with S. prenanti-EPO (SP-EPO). The results suggest that EPO in high-altitude schizothoracine species is both antioxidative and antiapoptotic, driven by the H131S mutation site. Thus, this enhanced the ability of this species to adapt to the high-altitude hypoxic environment. These results provide a basis for investigating further the hypoxia adaptation mechanisms of teleosts.

Evidence for diminished sensitivity of the hamster pulmonary vasculature to hypoxia

1982 ◽  
Vol 52 (6) ◽  
pp. 1571-1574 ◽  
Author(s):  
B. R. Walker ◽  
N. F. Voelkel ◽  
I. F. McMurtry ◽  
E. M. Adams
Keyword(s):  
Right Ventricular ◽  
High Altitude ◽  
Pressor Response ◽  
Weight Ratio ◽  
Pulmonary Vasculature ◽  
Hypoxic Exposure ◽  
Hypoxic Environment ◽  
Pulmonary Arterial ◽  
Low Altitude ◽  
Fossorial Species

Many mammals exhibit elevated pulmonary arterial pressure when exposed to airway hypoxia. In addition, prolonged hypoxic exposure may result in elevated hematocrit and right ventricular hypertrophy. The current study was designed to test whether the hamster, a fossorial species, may possess naturally selected physiological characteristics advantageous to a chronically hypoxic environment. Hamsters and rats were studied at low altitude (1,520 m) and after 5 wk at high altitude (4,250 m). Hematocrit for low-altitude hamsters was 53 +/- 1 compared with 45 +/- 1 for low-altitude rats. Low-altitude hamsters and rats demonstrated the same right ventricular weight-to-total ventricular weight ratio (RV/T) (0.223 +/- 0.006 vs. 0.222 +/- 0.003). After high-altitude exposure the hematocrit for hamsters and rats was the same (58 +/- 1 vs. 57 +/- 1), but RV/T was less in the hamster (0.251 +/- 0.004 vs. 0.288 +/- 0.005). In addition, the hypoxic pulmonary pressor response of lungs isolated from low- and high-altitude animals was examined. Lungs from hamsters were less responsive than lungs from rats at all levels of hypoxia tested. In addition, exposure to altitude resulted in a diminished pressor response in lungs from both species. It is concluded that the pulmonary vasculature of the hamster is less responsive to hypoxia than that of the rat, and that this relative unresponsiveness may aid the hamster in an hypoxic environment.

Characterization of High Altitude Turbulence for Air Force Platforms

2007 ◽  
Author(s):  
Frank H. Ruggiero ◽  
Joseph A. Werne ◽  
Alex Mahalov ◽  
Basil Nichols ◽  
Donald E. Wroblewski
Keyword(s):  
High Altitude ◽  
Air Force

scholarly journals Effect of High-Altitude Environment on Driving Safety: A Study on Drivers’ Mental Workload, Situation Awareness, and Driving Behaviour

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Xinyan Wang ◽  
Wu Bo ◽  
Weihua Yang ◽  
Suping Cui ◽  
Pengzi Chu
Keyword(s):  
High Altitude ◽  
Situation Awareness ◽  
Mental Workload ◽  
Mediating Effect ◽  
Driving Safety ◽  
Risky Driving ◽  
Driving Behaviour ◽  
Driving Risk ◽  
Low Altitude ◽  
The Relationship

This study aims to analyze the effect of high-altitude environment on drivers’ mental workload (MW), situation awareness (SA), and driving behaviour (DB), and to explore the relationship among those driving performances. Based on a survey, the data of 356 lowlanders engaging in driving activities at Tibetan Plateau (high-altitude group) and 341 lowlanders engaging in driving activities at low altitudes (low-altitude group) were compared and analyzed. The results suggest that the differences between the two groups are noteworthy. Mental workload of high-altitude group is significantly higher than that of low-altitude group, and their situation awareness is lower significantly. The possibility of risky driving behaviours for high-altitude group, especially aggressive violations, is higher. For the high-altitude group, the increase of mental workload can lead to an increase on aggressive violations, and the situation understanding plays a full mediating effect between mental workload and aggressive violations. Measures aiming at the improvement of situation awareness and the reduction of mental workload can effectively reduce the driving risk from high-altitude environment for lowlanders.

scholarly journals Effect of high altitude on human placental amino acid transport

2020 ◽  
Vol 128 (1) ◽  
pp. 127-133 ◽  
Author(s):  
Owen. R. Vaughan ◽  
Fredrick Thompson ◽  
Ramón. A. Lorca ◽  
Colleen G. Julian ◽  
Theresa L. Powell ◽  
...  
Keyword(s):  
Birth Weight ◽  
Amino Acid ◽  
High Altitude ◽  
Sea Level ◽  
Amino Acid Transport ◽  
Acid Uptake ◽  
Acid Transport ◽  
Transport Capacity ◽  
System A ◽  
Low Altitude

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.

scholarly journals Seasonal and Altitudinal Prevalence of Fascioliasis in Buffalo in Eastern Nepal

2018 ◽  
Vol 4 ◽  
pp. 48-53
Author(s):  
Ramesh Prasad Sah ◽  
Hari Kumar Prasai ◽  
Jiban Shrestha ◽  
Md Hasanuzzaman Talukder ◽  
AKM Anisur Rahman ◽  
...  
Keyword(s):  
High Risk ◽  
High Altitude ◽  
Sea Level ◽  
Rainy Season ◽  
Meat Production ◽  
Parasitic Diseases ◽  
Sedimentation Technique ◽  
Risk Period ◽  
Pasture Contamination ◽  
Low Altitude

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.

scholarly journals Morphological variation in Leptorhynchos squamatus (Gnaphalieae: Asteraceae)

2002 ◽  
Vol 15 (2) ◽  
pp. 205 ◽  
Author(s):  
Christina Flann ◽  
Pauline Y. Ladiges ◽  
Neville G. Walsh
Keyword(s):  
High Altitude ◽  
Morphological Variation ◽  
Environmental Conditions ◽  
Leaf Size ◽  
Alpine Plants ◽  
The Other ◽  
Herbarium Specimens ◽  
South Eastern ◽  
Eastern Australia ◽  
Low Altitude

A study of morphological variation in Leptorhynchos squamatus (Labill.) Less. across its range in south-eastern Australia was undertaken to test the hypothesis that L. squamatus includes two taxa. Phenetic pattern analyses of both field-collected and herbarium specimens on the basis of morphology confirmed two major groups. Bract, cypsela, pappus bristle and leaf characters were particularly important in separating the two groups. The taxa are separated by altitude differences with one being a low-altitude plant found in many habitats and the other being a high-altitude taxon that is a major component of alpine meadows. Lowland plants have dark bract tips, fewer and wider pappus bristles than alpine plants, papillae on the cypselas and more linear leaves. A somewhat intermediate population from the Major Mitchell Plateau in the Grampians shows some alpine and some lowland characters but is included in the lowland taxon. Seeds from five populations (two alpine, two lowland and Major Mitchell) were germinated and plants grown for 18 weeks under four controlled sets of environmental conditions. The experiment showed that leaf size and some other characters are affected by environmental conditions, but that there are underlying genetic differences between the lowland and alpine forms. Leptorhynchos squamatus subsp. alpinus Flann is described here to accommodate the highland taxon.

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