RESUMEN
Antarctic camps pose psychophysiological challenges related to isolated, confined, and extreme (ICE) conditions, including meals composed of sealed food. ICE conditions can influence the microbiome and inflammatory responses. Seven expeditioners took part in a 7-week Antarctic summer camp (Nelson Island) and were evaluated at Pre-Camp (i.e., at the beginning of the ship travel), Camp-Initial (i.e., 4th and 5th day in camp), Camp-Middle (i.e., 19th-20th, and 33rd-34th days), Camp-Final (i.e., 45th-46th day), and at the Post-Camp (on the ship). At the Pre-Camp, Camp-Initial, and Camp-Final, we assessed microbiome and inflammatory markers. Catecholamines were accessed Pre- and Post-Camp. Heart rate variability (HRV), leptin, thyroid stimulating hormone (TSH), and thyroxine (T4) were accessed at all time points. Students' t-tests or repeated-measures analysis of variance (one or two-way ANOVA) followed by Student-Newman-Keuls (post hoc) were used for parametric analysis. Kruskal-Wallis test was applied for non-parametric analysis. Microbiome analysis showed a predominance of Pseudomonadota (34.01%), Bacillota (29.82%), and Bacteroidota (18.54%), followed by Actinomycetota (5.85%), and Fusobacteria (5.74%). Staying in a long-term Antarctic camp resulted in microbiome fluctuations with a reduction in Pseudomonadota-a "microbial signature" of disease. However, the pro-inflammatory marker leptin and IL-8 tended to increase, and the angiogenic factor VEGF was reduced during camp. These results suggest that distinct Antarctic natural environments and behavioral factors modulate oral microbiome and inflammation.
RESUMEN
The remote sensing techniques must be used to obtain long-term information in remote areas, like the Antarctic continent, to monitor the environmental productivity and its changes. The aim of this work was to analyze the surface reflectance profile patterns for the Antarctic biological soil crusts (algae, lichens, and mosses) in an area of Nelson Island (South Shetland Islands, maritime Antarctic), calculated from Landsat and Sentinel-2 images to identify its similarities and differences due to targets, sensors and acquired date. The surface reflectance values for Antarctic biological soil crusts are similar for those observed for biological soil crusts in other Earth extreme environments, like deserts. In Landsat images, the differences among biological soil crusts surface reflectance were identified at visible and near-infrared wavelengths and for Sentinel-2 images, the differences occur at visible, red-edge and shortwave infrared wavelengths, showing the feasibility of using surface reflectance products to identify these different crusts, despite its inherent pixel spectral mixture. Long-term biophysical parameters from such crusts as retrieved from orbital data is not possible due to very low cloud-free images over the Antarctic, which prevents building a consistent surface reflectance time-series which covers all biological soil crusts growth season.
Asunto(s)
Briófitas , Líquenes , Regiones Antárticas , Plantas , SueloRESUMEN
We quantitatively describe for the first time the advertisement call of Chiasmocleis (Syncope) carvalhoi using recordings of five specimens from northern Peruvian Amazonia. The advertisement call is characterized by a single, short, tonal, and high-pitched note. Call duration ranges between 0.03-0.06 s and its dominant frequency between 7.12-7.92 kHz. The lack of pulses within notes distinguishes C. (Syncope) carvalhoi from all congeneric species except C. (Syncope) antenori, C. (Syncope) parkeri and C. (Chiasmocleis) mantiqueira, which can be distinguished by the shorter duration of their notes and silent intervals (in C. (Syncope) antenori and C. (Syncope) parkeri) and by the lower dominant frequency (in C. (Syncope) parkeri and C. (Chiasmocleis) mantiqueira). In addition, based on our collected specimens, we report on and discuss about the variation of some external morphological characters and natural history of C. (Syncope) carvalhoi, including the absence of vocal slits and sacs. Our study reveals a potential association between the absence of vocal slits and sacs, and tonal calls in Chiasmocleis, as well as conflicting morphological diagnostics characters in the literature.