Human adaptation to simulated gravitational fields.

E B Shulzhenko; I F Vil-Vilyams; V E Panfilov

doi:10.1016/0273-1177(81)90253-2

Home/Archive/PubMed

PubMed · 11541701

Human adaptation to simulated gravitational fields.

E B Shulzhenko·I F Vil-Vilyams·V E Panfilov

View original source ↗Export metadata ↓

Abstract

We present the results of manned studies in which test subjects were exposed to simulated zero g (water immersion or head-down tilt at -6 degrees) and head-to-feet acceleration. The findings give evidence that humans have different individual tolerances to an acceleration of +3 Gz after exposure to zero g, whether simulated by immersion or by head-down tilt. The paper discusses the functional relationship between water balance and cardiac output in the establishment of adaptive reactions to simulated zero g.

Explore related subjects

Adaptation, Physiological Adult Aerospace Medicine Blood Pressure Cardiac Output Centrifugation Head-Down Tilt Heart Rate Hemodynamics Humans Hypergravity Immersion Male Water Water-Electrolyte Balance Weightlessness Simulation Comparative Study Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

E B Shulzhenko, I F Vil-Vilyams, V E Panfilov. 1981. Human adaptation to simulated gravitational fields.. https://doi.org/10.1016/0273-1177(81)90253-2

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2025

Genome sequencing and population genetics provide insights into local adaptation of Opisthopappus species on cliff environments of Taihang Mountains.

Local adaptation represents a pivotal theme in evolutionary biology. The Opisthopappus genus, comprising Opisthopappus longilobus and O. taihangensis, thrives on the cliffs of the Taihang Mountains. During their evolutionary history, two species are hypothesized to have locally adapted to their cliff habitats. In the present study, we employed a combined approach of whole-genome sequencing of O. taihangensis and population genomic analysis from both species to gain deeper insights into their patterns of local adaptation. Our results revealed that the expansive genome of O. taihangensis (3010.18 Mb), a consequence of a whole-genome duplication (WGD) event, coupled with a high proportion of repetitive sequences (82.70%), was postulated as one of its adaptive strategies. A clear differentiation between O. taihangensis and O. longilobus was observed, with the two species diverging approximately 17.57 million years ago (Mya), with O. longilobus serving as the ancestor. Since their divergence, limited gene flow was observed between the two species. Post-divergence, the effective population sizes of both species expanded, yet underwent a dramatic reduction at approximately 0.07 Mya. Furthermore, a total of 798 adaptive genes were identified, of which 207 overlapped with expanded genes, and eight genes were found to be under positive selection. These genes primarily regulated the growth and development of both species via pathways such as oxidation-reduction and ubiquitin-proteasome, enabling them to withstand climate changes. These findings provide profound insights into the local adaptation of Opisthopappus species to the cliff environments and offer valuable clues for further exploring the local adaptation among various cliff-dwelling organisms.

Adaptation, Physiological↗

PubMed2015

Variation in Drosophila melanogaster central metabolic genes appears driven by natural selection both within and between populations.

In this report, we examine the hypothesis that the drivers of latitudinal selection observed in the eastern US Drosophila melanogaster populations are reiterated within seasons in a temperate orchard population in Pennsylvania, USA. Specifically, we ask whether alleles that are apparently favoured in northern populations are also favoured early in the spring, and decrease in frequency from the spring to autumn with the population expansion. We use SNP data collected for 46 metabolic genes and 128 SNPs representing the central metabolic pathway and examine for the aggregate SNP allele frequencies whether the association of allele change with latitude and that with increasing days of spring-autumn season are reversed. Testing by random permutation, we observe a highly significant negative correlation between these associations that is consistent with this expectation. This correlation is stronger when we confine our analysis to only those alleles that show significant latitudinal changes. This pattern is not caused by association with chromosomal inversions. When data are resampled using SNPs for amino acid change the relationship is not significant but is supported when SNPs associated with cis-expression are only considered. Our results suggest that climate factors driving latitudinal molecular variation in a metabolic pathway are related to those operating on a seasonal level within populations.

Adaptation, Physiological↗

PubMed2007

A novel protein kinase family in Plasmodium falciparum is differentially transcribed and secreted to various cellular compartments of the host cell.

Processes at the surface of Plasmodium falciparum-infected erythrocytes such as antigenic variation and cytoadhesion may be modulated by active signalling between host and parasite. Potential candidates for this role include the putative kinases of the FIKK family. The novel Apicomplexa-specific FIKK gene has expanded in P. falciparum to 20 sequence-related members distributed between 11 chromosomes. Specific antibodies raised against different members indicated that most FIKK proteins locate to punctate foci in the erythrocyte cytoplasm that colocalized with Maurer's clefts proteins. One FIKK member dissociates at the trophozoite stage from the Maurer's clefts and relocates with the erythrocyte cytoskeleton. Another FIKK protein, despite having a PEXEL motif, remains located within the parasite. FIKK proteins possess the essential residues for phosphotransferase activity. We show that protein kinase activity was detected in immunoprecipitates obtained with two anti-FIKK antibodies. Quantitative PCR analysis revealed differential gene transcription of the FIKK paralogues in asexual blood stages parasites. We observed significant changes in the transcription pattern between parasites with different adhesion phenotypes. Our data suggest a role of FIKK proteins in the remodelling of the erythrocyte surface and reveal the existence of an adaptable parasite system able to sense intra- and possibly extracellular changes.

Adaptation, Physiological↗