49 research outputs found
Revisión de la distribución y abundancia de la herpetofauna en las Islas Chafarinas: datos históricos vs. tendencias poblacionales
El estudio fue financiado por contratos
del Organismo Autónomo de Parques NacionalesPeer reviewe
Artificial recharge by means of careo channels versus natural aquifer recharge in a semi-arid, high-mountain watershed (Sierra Nevada, Spain)
[EN] The acequias de careo are ancestral water channels excavated during the early Al-Andalus period (8th-10th centuries), which are used to recharge aquifers in the watersheds of the Sierra Nevada mountain range (Southeastern Spain). The water channels are maintained by local communities, and their main function is collecting snowmelt, but also runoff from rainfall from the headwaters of river basins and distributing it throughout the upper parts of the slopes. This method of aquifer artificial recharge extends the availability of water resources in the lowlands of the river basins during the dry season when there is almost no precipitation and water demand is higher. This study investigates the contribution of the careo channels in the watershed of Bérchules concerning the total aquifer recharge during the 2014-2015 hydrological year. Several channels were gauged, and the runoff data were compared with those obtained from a semi-distributed hydrological model applied to the same hydrological basin. The natural infiltration of meteoric waters accounted for 52% of the total recharge, while the remaining 48% corresponded to water transported and infiltrated by the careo channels. In other words, the careo recharge system enhances by 92% the natural recharge to the aquifer. Our results demonstrate the importance of this ancestral and efficient channel system for recharging slope aquifers developed in hard rocks. The acequias de careo are nature-based solutions for increasing water resources availability that have contributed to a prosperous life in the Sierra Nevada. Its long history (>1200 years) suggests that the system has remarkable resilience properties, which have allowed adaptation and permance for centuries in drastically changing climatic and socioeconomic conditions. This recharge system could also be applied to -or inspire similar adaptation measures in- semi-arid mountain areas around the world where it may help in mitigating climate change effects.This research was undertaken as part of the project “Impact, monitoring and assessment of global and climate change on water resources in high-mountain National Parks (CCPM)”, with reference number CANOA-51.3.00.43.00 and funded by Organismo Autónomo Parques Nacionales from the Ministerio para la Transición Ecológica y el Reto Demográfico.Peer reviewe
Early mobilisation in critically ill COVID-19 patients: a subanalysis of the ESICM-initiated UNITE-COVID observational study
Background
Early mobilisation (EM) is an intervention that may improve the outcome of critically ill patients. There is limited data on EM in COVID-19 patients and its use during the first pandemic wave.
Methods
This is a pre-planned subanalysis of the ESICM UNITE-COVID, an international multicenter observational study involving critically ill COVID-19 patients in the ICU between February 15th and May 15th, 2020. We analysed variables associated with the initiation of EM (within 72 h of ICU admission) and explored the impact of EM on mortality, ICU and hospital length of stay, as well as discharge location. Statistical analyses were done using (generalised) linear mixed-effect models and ANOVAs.
Results
Mobilisation data from 4190 patients from 280 ICUs in 45 countries were analysed. 1114 (26.6%) of these patients received mobilisation within 72 h after ICU admission; 3076 (73.4%) did not. In our analysis of factors associated with EM, mechanical ventilation at admission (OR 0.29; 95% CI 0.25, 0.35; p = 0.001), higher age (OR 0.99; 95% CI 0.98, 1.00; p ≤ 0.001), pre-existing asthma (OR 0.84; 95% CI 0.73, 0.98; p = 0.028), and pre-existing kidney disease (OR 0.84; 95% CI 0.71, 0.99; p = 0.036) were negatively associated with the initiation of EM. EM was associated with a higher chance of being discharged home (OR 1.31; 95% CI 1.08, 1.58; p = 0.007) but was not associated with length of stay in ICU (adj. difference 0.91 days; 95% CI − 0.47, 1.37, p = 0.34) and hospital (adj. difference 1.4 days; 95% CI − 0.62, 2.35, p = 0.24) or mortality (OR 0.88; 95% CI 0.7, 1.09, p = 0.24) when adjusted for covariates.
Conclusions
Our findings demonstrate that a quarter of COVID-19 patients received EM. There was no association found between EM in COVID-19 patients' ICU and hospital length of stay or mortality. However, EM in COVID-19 patients was associated with increased odds of being discharged home rather than to a care facility.
Trial registration ClinicalTrials.gov: NCT04836065 (retrospectively registered April 8th 2021)
Factores que afectan a la supervivencia de los juveniles de la lagartija colilarga (Psammodromus algirus) : morfología, agresividad y uso del espacio
Se ha examinado, por medio de un estudio observacional y experimental, como influyen sobre la probabilidad de supervivencia,las siguientes variables: tamaño corporal, fecha de eclosión, comportamiento territorial, y características del dominio vital de los individuos juveniles de la lagartija colilarga (Psammodromus algirus). Los resultados muestran que una fecha de eclosión temprana, un mayor tamaño corporal y una condición corporal intermedia influyen positivamente en la probabilidad de supervivencia. Una mayor talla corporal es ventajoso en las peleas por los recursos y el espacio. Además, aquellos individuos más agresivos, poseían dominios vitales más grandes y de mejor calidad. Pero la agresividad tiene unos costes asociados, que se traducen en un retraso en el crecimiento corpora
Determinants of survival in juvenile Psammodromus algirus lizards
The study was supported by Dirección General de Investigación Científica y Técnica, Ministerio de Educación y Ciencia, project PB 97-1245, Spain (E.C.), and by The Swedish Natural Science Research Council (A.F.).
E. Civantos was funded by a pre-doctoral grant from Ministerio de Educación y Ciencia, Spain.Theories posit that the relative mortality rate of adults and juveniles is a major determinant of population dynamics and life history evolution. Moreover, differential survival of pre-reproductive individuals may be an important source of variation in lifetime reproductive success, and characters that influence survival of juveniles are likely to be under strong selection. We examined survival from hatching to maturity in a natural population of Psammodromus algirus lizards using data from a capture-mark-recapture study. We found that mortality from hatching to maturity was high: only 8% of males and 14% of females that hatched in 1996 survived the entire study period until maturity in spring 1998. The probability of survival was 75% during both the first and second overwinter periods when lizards were inactive most of the time, and about 25% during their first spring to autumn activity season. Our analyses further revealed significant associations between survival and snout-vent length, body condition, sex and microhabitat use. However, the relationship between survival and morphological characters varied among time periods, presumably because the sources of mortality during the activity season were different from those during hibernation. The association between survival and body condition also varied within time periods, both between large and small individuals and between the two sexes. This suggests that the relative importance of different selective agents may change during the life of individuals and vary between males and females due to differences in body size and behaviour.Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpu
Body temperature regulation in the amphisbaenian Trogonophis wiegmanni
Abstract: We studied the thermal ecology of the amphisbaenian Trogonophis wiegmanni at the Chafarinas Islands (North Africa). We aimed to evaluate the extent of thermoregulation in this fossorial amphisbaenian by analyzing the relationships between environmental available operative (T e ) and body (T b ) temperatures of active individuals found under stones. Amphisbaenians are typical thigmotherms that obtain heat through contact with soil and, thus, T b was closely correlated to T e under stones. However, the comparison of T b with T e s available in the study area indicated that T b deviated less from the set-point range of preferred temperatures than would result from a random response, which is indicative of behavioral temperature regulation. Measurements of T e under rocks selected by T. wiegmanni deviated significantly less from the range of preferred temperatures than T e beneath available rocks. This suggests that amphisbaenians occupied rocks with or when thermal properties were suitable for maintaining their preferred T b . We found a bimodal pattern of T b during the day, with amphisbaenians being active at higher T b during the afternoon than in the morning. This did not reflect changes in the thermal environment, but was presumably a voluntary selection pattern, as indicated by similar results obtained in thermal gradients in a previous study. Also, juveniles had higher T b than adults, but this might be a biophysical effect of differences in body size and heating rates. We conclude that amphisbaenians seem capable of regulating body temperature to an extent that comparable with epigeal diurnal lizards. Résumé : Nous avons étudié l'écologie thermique de l'amphisbénien Trogonophis wiegmanni dans les îles Chafarinas (Afrique du Nord). Notre objectif était d'évaluer l'importance de la thermorégulation chez cet amphisbénien fouisseur, par l'analyse des relations entre les températures de fonctionnement disponibles dans l'environnement (T e ) et la tempé-rature du corps (T b ), chez des individus actifs trouvés sous les pierres. Les amphisbéniens sont des organismes thigmothermes typiques qui captent la chaleur du sol par contact et, de ce fait, T b s'est révélée en corrélation étroite avec T e sous les pierres. Cependant, la comparaison de T b aux températures T e disponibles dans l'environnement indique que T b s'éloigne moins de l'étendue des valeurs de référence des températures préférées que si elle était déterminée de façon aléatoire, ce qui indique un contrôle comportemental de la température. Les températures T e sous les pierres choisies par T. wiegmanni s'éloignent moins de l'étendue des températures préférées que les températures T e sous les pierres disponibles. Cela semble indiquer que les amphisbéniens choisissent les pierres avec des propriétés thermiques qui permettent le maintien de leur température T b préférée. Nous avons constaté que la température T b suit une courbe bimodale durant le jour; les amphisbéniens sont plus actifs à des températures T b plus élevées l'après-midi que le matin. Cela ne reflète pas des changements dans l'environnement thermique, mais relève probablement d'un pattern de sélec-tion volontaire, si on en juge par les résultats semblables obtenus le long de gradients thermiques au cours d'une étude antérieure. De plus, les températures T b des juvéniles sont plus élevées que celles des adultes, mais il peut s'agir là d'un effet biophysique relié à des différences dans la taille du corps ou les taux de réchauffement. Les amphisbéniens semblent donc capables de contrôler la température de leur corps autant que le font les lézards épigées diurnes. [Traduit par la Rédaction] 47 López et al
Habitat type influences parasite load in Algerian Psammodromus lizards (Psammodromus algirus)
Understanding how habitat type and deterioration may affect parasitism is important to assess human-induced environmental change effects on host-parasite dynamics. In this study, we examined inter-population differences in parasites load in a Mediterranean lizard, Psammodromus algirus (Linnaeus, 1758). We analyzed prevalence and intensity of infection by blood parasites and ectoparasites in two populations separated by a 400-m elevational gradient and with different habitat types that also differed in the degree of human alteration. We also compared data obtained in the same populations after ten years lapsed to assess whether there have been temporary changes in parasites load. Results showed that prevalence and intensity of blood parasites were higher in the deteriorated lowland holm oak forest population than in the well preserved upland oak forest. In contrast, the prevalence and intensity of infection by Ixodes ticks was higher in the upland oak forest population. Individuals from the lowland population were in poorer condition. Intensities of infection by blood parasites and ectoparasites have decreased significantly from 2005-2006 to 2016 in both populations. Our results suggest that inter-population differences in parasite load may be explained by differences in habitat characteristics. This study contributes to identify which ecosystems and habitats are most sensitive to prevalence and intensity of infection by parasites.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author