scholarly journals Down Feather Structure Varies Between Low- and High-Altitude Torrent Ducks (Merganetta Armata) in the Andes

2017 ◽  
Author(s):  
Rebecca G. Cheek ◽  
Luis Alza ◽  
Kevin G. McCracken
Keyword(s):  
High Altitude ◽  
Environmental Conditions ◽  
Critical Role ◽  
Ambient Temperatures ◽  
The Andes ◽  
Significant Difference ◽  
General Constraints ◽  
Low Altitude ◽  
High Elevations ◽  
Two Populations

AbstractFeathers are one of the defining characteristics of birds and serve a critical role in thermal insulation and physical protection against the environment. Feather structure is known to vary among individuals, and it has been suggested that populations exposed to different environmental conditions may exhibit different patterns in feather structure. We examined both down and contour feathers from two populations of male Torrent Ducks (Merganetta armata) from Lima, Peru, including one high-altitude population from the Chancay-Huaral River at approximately 3500 meters (m) elevation and one low-altitude population from the Chillón River at approximately 1500 m. Down feather structure differed significantly between the two populations. Ducks from the high-altitude population had longer, denser down compared with low-altitude individuals. Contour feather structure varied greatly among individuals but showed no significant difference between populations. These results suggest that the innermost, insulative layer of plumage (the down), may have developed in response to lower ambient temperatures at high elevations. The lack of observable differences in the contour feathers may be due to the general constraints of the waterproofing capability of this outer plumage layer.ResumenEl plumaje es una característica que define a las aves y cumple roles críticos en el aislamiento térmico y protección física del ambiente. Se sabe que la estructura de las plumas varía ente individuos, y se ha sugerido que poblaciones expuestas a diferentes condiciones ambientales pueden exhibir diferentes patrones en la estructura de las plumas. En este estudio se examinaron tanto el plumón como las plumas de contorno de machos adultos del Pato de los Torrentes (Merganetta armata) de dos poblaciones, una en el río Chancay-Huaral a 3,500 msnm y otra en el río Chillón a 1,500 msnm, ubicadas en Lima, Perú. La estructura de los plumones difiere significativamente entre las dos poblaciones. Los patos de la población a grandes elevaciones tienen plumones largos, y densos comparados con los individuos de las partes bajas. La estructura de las plumas de contorno varía ampliamente entre individuos pero no muestra diferencias significativas entre poblaciones. Estos resultados sugieren que las diferencias entre las capas interiores de aislamiento del plumaje (plumón), haberse desarrollado como respuesta en ambientes de bajas temperaturas a grandes elevaciones. En cambio la falta de detectables diferencias en las plumas de contorno puede ser debido a la constante selección en la capacidad impermeable de la capa de plumas exteriores.

scholarly journals Characterization of gut microbial community of rhesus macaques under the high-altitude extreme environments

2019 ◽  
Author(s):  
Yuhan Wu ◽  
Yongfang Yao ◽  
Mengmeng Dong ◽  
Tianrui Xia ◽  
Diyan Li ◽  
...  
Keyword(s):  
Microbial Community ◽  
High Altitude ◽  
Diversity Index ◽  
Rhesus Macaques ◽  
Critical Role ◽  
Gene Copy ◽  
Control Group ◽  
Significant Difference ◽  
Low Altitude ◽  
Gut Microbial Community

Abstract Background: The mammal intestinal microbita involved in various physiological processes in host and play a key role in host environment adaption. However, for non-human primate(NHP), little is known about their gut microbial community in high-altitude extreme environment and much less to their adaption to high-altitude environment. In this study, we want to characterize gut microbial community of rhesus macaques from multiple high-altitude environment and by comparing it to low-altitude control group to reveal the differences between altitudes. Results: we collected the fecal samples of rhesus macaques from four high-altitude populations (above 3000m) and one low-altitude population (below 100m). We first analyzed the overlap of operational taxonomic units (OTUs) between populations and found 27.8% of OTUs (core OTUs) were shared by all five population.The majority of these OTUs have a higher abundance, whereas the unique OTUs have a lower abundance. By calculating alpha diversity index, we found high-altitude populations exhibited higher diversity. Statistical analysis of beta diversity indicated there were significant difference between high and low altitude population. Significant difference in composition were detected at phylum and family. At phylum level, high-altitude gut microbial community were dominanted by Firmicutes(63.7%), but low-altitude were dominated by Bacteroidetes(52.2%). At family level, high-alititude population were dominanted by Ruminococcaceae(36.4%), but low-altitude were dominated by Prevotellaceae(43.9%). Additionally, the abundance of Christensenellaceae are significantly higher in all high-altitude populations(3.33%) than low-altitude population(0.77%), despite a low abundance in two altitudes. Finally, function prediction indicated there was a significant difference in gene copy number of 29 level-2 pathway between high and low altitude population; and 26 of them are higher in high-altitude, especially in membrane transport and carbohydrate metabolism. Conclusions: We found the gut microbial community of high-altitude rhesus macaques is significantly distinct from low-altitude population in diversity, composition and function. High-altitude populations were dominanted by Firmicutes and Ruminococcace, but low-altitude population by Bacteroidetes and Prevotellaceae. The difference in gut microbiota between two altitude macaque populations may be caused by different host diet, environmental temperature and oxygen pressure, and gut microbial microorganisms may play an critical role in adaptive evolution of rhesus macaques to high-altitude environment.

scholarly journals Characterisation of the gut microbial community of rhesus macaques in high-altitude environments

2020 ◽  
Author(s):  
Yuhan Wu ◽  
Yongfang Yao ◽  
Mengmeng Dong ◽  
Tianrui Xia ◽  
Diyan Li ◽  
...  
Keyword(s):  
Microbial Community ◽  
High Altitude ◽  
Diversity Index ◽  
Rhesus Macaques ◽  
Critical Role ◽  
Alpha Diversity ◽  
Gene Copy ◽  
Significant Difference ◽  
Low Altitude ◽  
Gut Microbial Community

Abstract Background: The mammal intestinal microbiota is involved in various physiological processes and plays a key role in host environment adaption. However, for non-human primates (NHPs), little is known about their gut microbial community in high-altitude environments and even less about their adaption to such habitats. We characterised the gut microbial community of rhesus macaques from multiple high-altitude environments and compared it to those of low-altitude populations. Results: We collected faecal samples of rhesus macaques from four high-altitude populations (above 3,000 m) and three low-altitude populations (below 500 m). By calculating the alpha diversity index, we found that high-altitude populations exhibited a higher diversity. Statistical analysis of beta diversity indicated significant differences between high- and low-altitude populations. Significant differences were also detected at the phylum and family levels. At the phylum level, the high-altitude gut microbial community was dominated by Firmicutes (63.42%), while at low altitudes, it was dominated by Bacteroidetes (47.4%). At the family level, the high-altitude population was dominated by Ruminococcaceae (36.2%), while the low-altitude one was dominated by Prevotellaceae (39.6%). Some families, such as Christensenellaceae, were consistently higher abundant in all high-altitude populations. We analysed the overlap of operational taxonomic units (OTUs) in high-altitude populations and determined their core OTUs (shared by all four high-altitude populations). However, when compared with the low-altitude core OTUs, only 65% were shared, suggesting a divergence in core OTUs. Function prediction indicated a significant difference in gene copy number of 35 level-2 pathways between high- and low-altitude populations; 29 of them were higher in high altitudes, especially in membrane transport and carbohydrate metabolism. Conclusions: The gut microbial community of high-altitude rhesus macaques was significantly distinct from that of low-altitude populations in terms of diversity, composition and function. High-altitude populations were dominated by Firmicutes and Ruminococcace, while in low-altitude populations, Bacteroidetes and Prevotellaceae were dominant. The difference in gut microbiota between these two populations may be caused by differences in host diet, environmental temperature and oxygen pressure. These gut microbial microorganisms may play a critical role in the adaptive evolution of rhesus macaques to high-altitude environments.

scholarly journals Characterisation of the gut microbial community of rhesus macaques in high-altitude environments

2020 ◽  
Author(s):  
Yuhan Wu ◽  
Yongfang Yao ◽  
Mengmeng Dong ◽  
Tianrui Xia ◽  
Diyan Li ◽  
...  
Keyword(s):  
Microbial Community ◽  
High Altitude ◽  
Diversity Index ◽  
Rhesus Macaques ◽  
Critical Role ◽  
Alpha Diversity ◽  
Gene Copy ◽  
Significant Difference ◽  
Low Altitude ◽  
Gut Microbial Community

Abstract Background: The mammal intestinal microbiota is involved in various physiological processes and plays a key role in host environment adaption. However, for non-human primates (NHPs), little is known about their gut microbial community in high-altitude environments and even less about their adaption to such habitats. We characterised the gut microbial community of rhesus macaques from multiple high-altitude environments and compared it to those of low-altitude populations. Results: We collected faecal samples of rhesus macaques from four high-altitude populations (above 3,000 m) and three low-altitude populations (below 500 m). By calculating the alpha diversity index, we found that high-altitude populations exhibited a higher diversity. Statistical analysis of beta diversity indicated significant differences between high- and low-altitude populations. Significant differences were also detected at the phylum and family levels. At the phylum level, the high-altitude gut microbial community was dominated by Firmicutes (63.42%), while at low altitudes, it was dominated by Bacteroidetes (47.4%). At the family level, the high-altitude population was dominated by Ruminococcaceae (36.2%), while the low-altitude one was dominated by Prevotellaceae (39.6%). Some families, such as Christensenellaceae and Rikenellaceae, were consistently higher abundant in all high-altitude populations. We analysed the overlap of operational taxonomic units (OTUs) in high-altitude populations and determined their core OTUs (shared by all four high-altitude populations). However, when compared with the low-altitude core OTUs, only 65% were shared, suggesting a divergence in core OTUs. Function prediction indicated a significant difference in gene copy number of 35 level-2 pathways between high- and low-altitude populations; 29 of them were higher in high altitudes, especially in membrane transport and carbohydrate metabolism. Conclusions: The gut microbial community of high-altitude rhesus macaques was significantly distinct from that of low-altitude populations in terms of diversity, composition and function. High-altitude populations were dominated by Firmicutes and Ruminococcace, while in low-altitude populations, Bacteroidetes and Prevotellaceae were dominant. The difference in gut microbiota between these two populations may be caused by differences in host diet, environmental temperature and oxygen pressure. These differentiated gut microbial microorganisms may play a critical role in the adaptive evolution of rhesus macaques to high-altitude environments.

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.

scholarly journals Tropical tropospheric ozone derived using Clear-Cloudy Pairs (CCP) of TOMS measurements

2003 ◽  
Vol 3 (1) ◽  
pp. 225-252 ◽  
Author(s):  
M. J. Newchurch ◽  
D. Sun ◽  
J. H. Kim ◽  
X. Liu
Keyword(s):  
High Altitude ◽  
Tropospheric Ozone ◽  
Total Ozone ◽  
Stratospheric Ozone ◽  
Lower Troposphere ◽  
Total Ozone Mapping Spectrometer ◽  
Significant Difference ◽  
Retrieval Efficiency ◽  
Retrieval Errors ◽  
Low Altitude

Abstract. Using TOMS total-ozone measurements over high-altitude cloud locations and nearby paired clear locations, we describe the Clear-Cloudy Pairs (CCP) method for deriving tropical tropospheric ozone. The high-altitude clouds are identified by measured 380 nm reflectivities greater than 80% and Temperature Humidity InfraRed (THIR) measured cloud-top pressures less than 200 hPa. To account for locations without high-altitude clouds, we apply a zonal sine fitting to the stratospheric ozone derived from available cloudy points, resulting in a wave-one amplitude of about 4 DU. THIR data is unavailable after November 1984, so we extend the CCP method by using a reflectivity threshold of 90% to identify high-altitude clouds and remove the influence of high-reflectivity-but-low-altitude clouds with a lowpass frequency filter. We correct ozone retrieval errors associated with clouds, and ozone retrieval errors due to sun glint and aerosols. Comparing CCP results with Southern Hemisphere ADditional OZonesondes (SHADOZ) tropospheric ozone indicates that CCP tropospheric ozone and ozonesonde measurements are highly consistent. The most significant difference between CCP and ozonesonde tropospheric ozone can be explained by the low Total Ozone Mapping Spectrometer (TOMS) retrieval efficiency of ozone in the lower troposphere.

scholarly journals Tropical tropospheric ozone derived using Clear-Cloudy Pairs (CCP) of TOMS measurements

2003 ◽  
Vol 3 (3) ◽  
pp. 683-695 ◽  
Author(s):  
M. J. Newchurch ◽  
D. Sun ◽  
J. H. Kim ◽  
X. Liu
Keyword(s):  
High Altitude ◽  
Tropospheric Ozone ◽  
Total Ozone ◽  
Stratospheric Ozone ◽  
Lower Troposphere ◽  
Significant Difference ◽  
Retrieval Efficiency ◽  
The Mean ◽  
Retrieval Errors ◽  
Low Altitude

Abstract. Using TOMS total-ozone measurements over high-altitude cloud locations and nearby paired clear locations, we describe the Clear-Cloudy Pairs (CCP) method for deriving tropical tropospheric ozone. The high-altitude clouds are identified by measured 380 nm reflectivities greater than 80% and Temperature Humidity InfraRed (THIR) measured cloud-top pressures less than 200 hPa. To account for locations without high-altitude clouds, we apply a zonal sine fitting to the stratospheric ozone derived from available cloudy points, resulting in a wave-one amplitude of about 4 DU. THIR data is unavailable after November 1984, so we extend the CCP method by using a reflectivity threshold of 90% to identify high-altitude clouds and remove the influence of high-reflectivity-but-low-altitude clouds with a lowpass frequency filter. We correct ozone retrieval errors associated with clouds, and ozone retrieval errors due to sun glint and aerosols. Comparing CCP results with Southern Hemisphere ADditional OZonesondes (SHADOZ) tropospheric ozone indicates that CCP tropospheric ozone and ozonesonde measurements agree, on average, to within 3 ± 1 DU standard error of the mean. The most significant difference between CCP and ozonesonde tropospheric ozone can be explained by the low Total Ozone Mapping Spectrometer (TOMS) version-7 retrieval efficiency of ozone in the lower troposphere.

scholarly journals Hematological parameters of high and low altitude Tibetan populations

2020 ◽  
Author(s):  
Nipa Basak ◽  
Tsering Norboo ◽  
Mohammed S. Mustak ◽  
Kumarasamy Thangaraj
Keyword(s):  
High Altitude ◽  
Hematological Parameters ◽  
Hemoglobin Concentration ◽  
P Value ◽  
Mean Corpuscular Hemoglobin ◽  
Tibetan Population ◽  
Significant Difference ◽  
High Altitude Acclimatization ◽  
Low Altitude ◽  
The Difference

AbstractHigh altitude hypoxia is believed to be experienced at elevations more than 2500 meters. A few studies have shed light on the biochemical aspects of high altitude acclimatization that profoundly included the subjects sojourning to the high altitude from low altitude and observation of the transient changes. However, information regarding the difference between the adapted people in high altitude and their counterpart, who reside in the low altitude are lacking. To address that issue, we have measured various hematological parameters and level of serum erythropoietin (EPO) in Tibetan population, who are residing in both high and low altitudes. We observed significant difference (p value < 0.0001) between high and low altitude Tibetan, in various hematological parameters, including red blood cells (RBC) count, hematocrit (HCT) or packed cell volume (PCV), and hemoglobin concentration (Hb). In case of mean corpuscular volume (MCV), significant difference was observed only in females (p value < 0.0001). Mean corpuscular hemoglobin concentration (MCHC) was significantly different between both males and females, but age was a potential confounder. There was no significant difference in serum EPO level between these two groups, either in males or females, which might be due to blunted erythropoietin response in the Tibetan population. We have also analyzed correlation between serum EPO with Hb and serum EPO with HCT and found no significant correlation. In multiple regression analysis, low altitude and male-gender showed significant impact on both Hb and HCT. In conclusion, our study suggests significant perturbation of hematological parameters, when native high altitude populations migrated to low altitude and inhabited for a long period.

scholarly journals Convergent changes in muscle metabolism depend on duration of high-altitude ancestry across Andean waterfowl

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Neal J Dawson ◽  
Luis Alza ◽  
Gabriele Nandal ◽  
Graham R Scott ◽  
Kevin G McCracken
Keyword(s):  
High Altitude ◽  
Flight Muscle ◽  
Muscle Metabolism ◽  
Mitochondrial Oxidative Phosphorylation ◽  
Evolutionary Time ◽  
Hexokinase Activity ◽  
Biochemical Pathways ◽  
The Andes ◽  
Hydroxyacyl Coa Dehydrogenase ◽  
Low Altitude

High-altitude environments require that animals meet the metabolic O2 demands for locomotion and thermogenesis in O2-thin air, but the degree to which convergent metabolic changes have arisen across independent high-altitude lineages or the speed at which such changes arise is unclear. We examined seven high-altitude waterfowl that have inhabited the Andes (3812–4806 m elevation) over varying evolutionary time scales, to elucidate changes in biochemical pathways of energy metabolism in flight muscle relative to low-altitude sister taxa. Convergent changes across high-altitude taxa included increased hydroxyacyl-coA dehydrogenase and succinate dehydrogenase activities, decreased lactate dehydrogenase, pyruvate kinase, creatine kinase, and cytochrome c oxidase activities, and increased myoglobin content. ATP synthase activity increased in only the longest established high-altitude taxa, whereas hexokinase activity increased in only newly established taxa. Therefore, changes in pathways of lipid oxidation, glycolysis, and mitochondrial oxidative phosphorylation are common strategies to cope with high-altitude hypoxia, but some changes require longer evolutionary time to arise.

scholarly journals Effect of chronic perinatal hypoxia on the role of rho-kinase in pulmonary artery contraction in newborn lambs

2013 ◽  
Vol 304 (2) ◽  
pp. R136-R146 ◽  
Author(s):  
Arlin B. Blood ◽  
Michael H. Terry ◽  
Travis A. Merritt ◽  
Demosthenes G. Papamatheakis ◽  
Quintin Blood ◽  
...  
Keyword(s):  
Pulmonary Artery ◽  
High Altitude ◽  
Chronic Hypoxia ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Acute Hypoxia ◽  
Rho Kinase ◽  
In Vivo Studies ◽  
Significant Difference ◽  
Low Altitude

Exposure to chronic hypoxia during gestation predisposes infants to neonatal pulmonary hypertension, but the underlying mechanisms remain unclear. Here, we test the hypothesis that moderate continuous hypoxia during gestation causes changes in the rho-kinase pathway that persist in the newborn period, altering vessel tone and responsiveness. Lambs kept at 3,801 m above sea level during gestation and the first 2 wk of life were compared with those with gestation at low altitude. In vitro studies of isolated pulmonary arterial rings found a more forceful contraction in response to KCl and 5-HT in high-altitude compared with low-altitude lambs. There was no difference between the effects of blockers of various pathways of extracellular Ca2+ entry in low- and high-altitude arteries. In contrast, inhibition of rho-kinase resulted in significantly greater attenuation of 5-HT constriction in high-altitude compared with low-altitude arteries. High-altitude lambs had higher baseline pulmonary artery pressures and greater elevations in pulmonary artery pressure during 15 min of acute hypoxia compared with low-altitude lambs. Despite evidence for an increased role for rho-kinase in high-altitude arteries, in vivo studies found no significant difference between the effects of rho-kinase inhibition on hypoxic pulmonary vasoconstriction in intact high-altitude and low-altitude lambs. We conclude that chronic hypoxia in utero results in increased vasopressor response to both acute hypoxia and serotonin, but that rho-kinase is involved only in the increased response to serotonin.

scholarly journals Life Ascending: Mechanism and Process in Physiological Adaptation to High-Altitude Hypoxia

2019 ◽  
Vol 50 (1) ◽  
pp. 503-526 ◽  
Author(s):  
Jay F. Storz ◽  
Graham R. Scott
Keyword(s):  
High Altitude ◽  
Environmental Conditions ◽  
Physiological Adaptation ◽  
Aerobic Performance ◽  
Cardiorespiratory System ◽  
Transport Pathway ◽  
Altitudinal Variation ◽  
Air Breathing ◽  
High Altitude Natives ◽  
Low Altitude

To cope with the reduced availability of O2 at high altitude, air-breathing vertebrates have evolved myriad adjustments in the cardiorespiratory system to match tissue O2 delivery with metabolic O2 demand. We explain how changes at interacting steps of the O2 transport pathway contribute to plastic and evolved changes in whole-animal aerobic performance under hypoxia. In vertebrates native to high altitude, enhancements of aerobic performance under hypoxia are attributable to a combination of environmentally induced and evolved changes in multiple steps of the pathway. Additionally, evidence suggests that many high-altitude natives have evolved mechanisms for attenuating maladaptive acclimatization responses to hypoxia, resulting in counter-gradient patterns of altitudinal variation for key physiological phenotypes. For traits that exhibit counteracting environmental and genetic effects, evolved changes in phenotype may be cryptic under field conditions and can only be revealed by rearing representatives of high- and low-altitude populations under standardized environmental conditions to control for plasticity.

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