176 research outputs found
Water seepage beneath dams on soluble evaporite deposits: a laboratory and field study (Caspe Dam, Spain)
The paper presents analytical methods and results for assessing the variation in the concentration of sulphate (and other ions) over space and time in groundwater flowing through a soluble evaporite terrain beneath a dam. The influence of effective porosity, groundwater flow velocity and the specific rate of dissolution (KâČ) are considered. The theoretical analysis was tested in a scale model simulating a dam constructed on heavily karstified bedrock. A simple and useful method for assessing how much material is lost through dissolution and how the rate of dissolution changes over time is considered in the context of the Caspe Dam, Spain
A hypothetico-deductive approach to assessing the social function of chemical signalling in a non-territorial solitary carnivore
The function of chemical signalling in non-territorial solitary carnivores is still relatively unclear. Studies on territorial solitary and social carnivores have highlighted odour capability and utility, however the social function of chemical signalling in wild carnivore populations operating dominance hierarchy social systems has received little attention. We monitored scent marking and investigatory behaviour of wild brown bears Ursus arctos, to test multiple hypotheses relating to the social function of chemical signalling. Camera traps were stationed facing bear âmarking treesâ to document behaviour by different age sex classes in different seasons. We found evidence to support the hypothesis that adult males utilise chemical signalling to communicate dominance to other males throughout the non-denning period. Adult females did not appear to utilise marking trees to advertise oestrous state during the breeding season. The function of marking by subadult bears is somewhat unclear, but may be related to the behaviour of adult males. Subadults investigated trees more often than they scent marked during the breeding season, which could be a result of an increased risk from adult males. Females with young showed an increase in marking and investigation of trees outside of the breeding season. We propose the hypothesis that females engage their dependent young with marking trees from a young age, at a relatively âsafeâ time of year. Memory, experience, and learning at a young age, may all contribute towards odour capabilities in adult bears
Scale of Auditory Behaviors e testes auditivos comportamentais para avaliação do processamento auditivo em crianças falantes do portuguĂȘs europeu
PURPOSE: The objective of this research was to assess the auditory abilities of Portuguese children and compare such abilities to the score of the Scale of Auditory Behaviors (SAB).
METHODS: Fifty-one children were evaluated with audiometry, speech audiometry, acoustic immittance measures, and eight behavioral tests involving dichotic listening, monotic listening, temporal processing, and sound localization. Their parents filled in the SAB questionnaire adapted to European A. SAB scores and auditory tests scores were submitted to Pearson's correlation coefficient.
RESULTS: There is significant correlation between the score on SAB questionnaire and the auditory processing tests. The greatest coefficient was observed in temporal processing test (p=0.000).
CONCLUSION: There was correlation between the score of SAB and the performance in auditory processing tests, suggesting that the SAB may be used for auditory processing screening.OBJETIVO: Investigar as habilidades auditivas de crianças portuguesas e verificar se hå correlação entre aquelas e o escore do Scale of Auditory Behaviors (SAB).
MĂTODOS: Todas as crianças foram submetidas a audiometria tonal, logoaudiometria, medidas de imitĂąncia acĂșstica e oito testes comportamentais do processamento auditivo, envolvendo tarefas de escuta dicĂłtica, escuta monĂłtica, processamento temporal e localização sonora. Os pais das 51 crianças portuguesas avaliadas preencheram o questionĂĄrio SAB adaptado ao portuguĂȘs europeu. Foram calculados os valores do coeficiente de correlação de Pearson entre os escores obtidos no questionĂĄrio e os dos testes do processamento auditivo.
RESULTADOS: Observou-se correlação significativa entre o escore do questionårio e o dos testes comportamentais, tendo a maior sido observada nos testes relacionados ao processamento temporal (p=0,000).
CONCLUSĂO: Houve correlação entre o escore da SAB e os resultados obtidos nos testes auditivos comportamentais em crianças portuguesas, sugerindo que este questionĂĄrio pode ser utilizado em triagem do processamento auditivo.CIEC â Research Centre on Child Studies, UM (FCT R&D 317
Severe Hypercapnia and Outcome of Mechanically Ventilated Patients with Moderate or Severe Acute Respiratory Distress Syndrome
PURPOSE:
To analyze the relationship between hypercapnia developing within the first 48 h after the start of mechanical ventilation and outcome in patients with acute respiratory distress syndrome (ARDS).
PATIENTS AND METHODS:
We performed a secondary analysis of three prospective non-interventional cohort studies focusing on ARDS patients from 927 intensive care units (ICUs) in 40 countries. These patients received mechanical ventilation for more than 12 h during 1-month periods in 1998, 2004, and 2010. We used multivariable logistic regression and a propensity score analysis to examine the association between hypercapnia and ICU mortality.
MAIN OUTCOMES:
We included 1899 patients with ARDS in this study. The relationship between maximum PaCO2 in the first 48 h and mortality suggests higher mortality at or above PaCO2 of â„50 mmHg. Patients with severe hypercapnia (PaCO2 â„50 mmHg) had higher complication rates, more organ failures, and worse outcomes. After adjusting for age, SAPS II score, respiratory rate, positive end-expiratory pressure, PaO2/FiO2 ratio, driving pressure, pressure/volume limitation strategy (PLS), corrected minute ventilation, and presence of acidosis, severe hypercapnia was associated with increased risk of ICU mortality [odds ratio (OR) 1.93, 95% confidence interval (CI) 1.32 to 2.81; p = 0.001]. In patients with severe hypercapnia matched for all other variables, ventilation with PLS was associated with higher ICU mortality (OR 1.58, CI 95% 1.04-2.41; p = 0.032).
CONCLUSIONS:
Severe hypercapnia appears to be independently associated with higher ICU mortality in patients with ARDS.info:eu-repo/semantics/publishedVersio
Tabagismo, consumo de ĂĄlcool e atividade fĂsica: associaçÔes na sĂndrome coronariana aguda
Inmunohistochemical Profile of Solid Cell Nest of Thyroid Gland
It is widely held that solid cell nests (SCN) of the thyroid are ultimobranchial body remnants. SCNs are composed of main cells and C cells. It has been suggested that main cells might be pluripotent cells contributing to the histogenesis of C cells and follicular cells, as well as to the formation of certain thyroid tumors. The present study sought to analyze the immunohistochemical profile of SCN and to investigate the potential stem cell role of SCN main cells. Tissue sections from ten cases of nodular hyperplasia (non-tumor goiter) with SCNs were retrieved from the files of the Hospital Infanta Luisa (Seville, Spain). Parathormone (PTH), calcitonin (CT), thyroglobulin (TG), thyroid transcription factor (TTF-1), galectin 3 (GAL3), cytokeratin 19 (CK 19), p63, bcl-2, OCT4, and SALL4 expression were evaluated by immunohistochemistry. Patient clinical data were collected, and tissue sections were stained with hematoxylinâeosin for histological examination. Most cells stained negative for PTH, CT, TG, and TTF-1. Some cells staining positive for TTF-1 and CT required discussion. However, bcl-2, p63, GAL3, and CK 19 protein expression was detected in main cells. OCT4 protein expression was detected in only two cases, and SALL4 expression in none. Positive staining for bcl-2 and p63, and negative staining for PTH, CT, and TG in SCN main cells are both consistent with the widely accepted minimalist definition of stem cells, thus supporting the hypothesis that they may play a stem cell role in the thyroid gland, although further research will be required into stem cell markers. Furthermore, p63 and GAL-3 staining provides a much more sensitive means of detecting SCNs than staining for carcinoembryonic antigen, calcitonin, or other markers; this may help to distinguish SCNs from their mimics
Desert Farming Benefits from Microbial Potential in Arid Soils and Promotes Diversity and Plant Health
BACKGROUND: To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known. METHODOLOGY/PRINCIPAL FINDINGS: We studied the impact of long-term agriculture on desert soil in one of the most prominent examples for organic desert farming in Sekem (Egypt). Using a polyphasic methodological approach to analyse microbial communities in soil as well as associated with cultivated plants, drastic effects caused by 30 years of agriculture were detected. Analysing bacterial fingerprints, we found statistically significant differences between agricultural and native desert soil of about 60%. A pyrosequencing-based analysis of the 16S rRNA gene regions showed higher diversity in agricultural than in desert soil (Shannon diversity indices: 11.21/7.90), and displayed structural differences. The proportion of Firmicutes in field soil was significantly higher (37%) than in the desert (11%). Bacillus and Paenibacillus play the key role: they represented 96% of the antagonists towards phytopathogens, and identical 16S rRNA sequences in the amplicon library and for isolates were detected. The proportion of antagonistic strains was doubled in field in comparison to desert soil (21.6%/12.4%); disease-suppressive bacteria were especially enriched in plant roots. On the opposite, several extremophilic bacterial groups, e.g., Acidimicrobium, Rubellimicrobium and Deinococcus-Thermus, disappeared from soil after agricultural use. The N-fixing Herbaspirillum group only occurred in desert soil. Soil bacterial communities were strongly driven by the a-biotic factors water supply and pH. CONCLUSIONS/SIGNIFICANCE: After long-term farming, a drastic shift in the bacterial communities in desert soil was observed. Bacterial communities in agricultural soil showed a higher diversity and a better ecosystem function for plant health but a loss of extremophilic bacteria. Interestingly, we detected that indigenous desert microorganisms promoted plant health in desert agro-ecosystems
Increased noise levels have different impacts on the anti-predator behaviour of two sympatric fish species.
types: Journal ArticleCopyright: © 2014 Voellmy et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Animals must avoid predation to survive and reproduce, and there is increasing evidence that man-made (anthropogenic) factors can influence predator-prey relationships. Anthropogenic noise has been shown to have a variety of effects on many species, but work investigating the impact on anti-predator behaviour is rare. In this laboratory study, we examined how additional noise (playback of field recordings of a ship passing through a harbour), compared with control conditions (playback of recordings from the same harbours without ship noise), affected responses to a visual predatory stimulus. We compared the anti-predator behaviour of two sympatric fish species, the three-spined stickleback (Gasterosteus aculeatus) and the European minnow (Phoxinus phoxinus), which share similar feeding and predator ecologies, but differ in their body armour. Effects of additional-noise playbacks differed between species: sticklebacks responded significantly more quickly to the visual predatory stimulus during additional-noise playbacks than during control conditions, while minnows exhibited no significant change in their response latency. Our results suggest that elevated noise levels have the potential to affect anti-predator behaviour of different species in different ways. Future field-based experiments are needed to confirm whether this effect and the interspecific difference exist in relation to real-world noise sources, and to determine survival and population consequences.University of BristolBasler Stiftung fĂŒr Biologische ForschungDefr
Molecular Tools for Monitoring the Ecological Sustainability of a Stone Bio-Consolidation Treatment at the Royal Chapel, Granada
Background:
Biomineralization processes have recently been applied in situ to protect and consolidate decayed ornamental stone of the Royal Chapel in Granada (Spain). While this promising method has demonstrated its efficacy regarding strengthening of the stone, little is known about its ecological sustainability.Methodology/Principal Findings:
Here, we report molecular monitoring of the stone-autochthonous microbiota before and at 5, 12 and 30 months after the bio-consolidation treatment (medium/long-term monitoring), employing the well-known molecular strategy of DGGE analyses. Before the bio-consolidation treatment, the bacterial diversity showed the exclusive dominance of Actinobacteria (100%), which decreased in the community (44.2%) after 5 months, and Gamma-proteobacteria (30.24%) and Chloroflexi (25.56%) appeared. After 12 months, Gamma-proteobacteria vanished from the community and Cyanobacteria (22.1%) appeared and remained dominant after thirty months, when the microbiota consisted of Actinobacteria (42.2%) and Cyanobacteria (57.8%) only. Fungal diversity showed that the Ascomycota phylum was dominant before treatment (100%), while, after five months, Basidiomycota (6.38%) appeared on the stone, and vanished again after twelve months. Thirty months after the treatment, the fungal population started to stabilize and Ascomycota dominated on the stone (83.33%) once again. Members of green algae (Chlorophyta, Viridiplantae) appeared on the stone at 5, 12 and 30 months after the treatment and accounted for 4.25%, 84.77% and 16.77%, respectively.Conclusions:
The results clearly show that, although a temporary shift in the bacterial and fungal diversity was observed during the first five months, most probably promoted by the application of the bio-consolidation treatment, the microbiota tends to regain its initial stability in a few months. Thus, the treatment does not seem to have any negative side effects on the stone-autochthonous microbiota over that time. The molecular strategy employed here is suggested as an efficient monitoring tool to assess the impact on the stone-autochthonous microbiota of the application of biomineralization processes as a restoration/conservation procedure.This work was supported by the European Regional Development Fund (ERDF), Junta de AndalucĂa (Spain) and the âFortalecimiento de la I+D+iâ program from the University of Granada, co-financed by grant RNM-3493 and Research Group BIO-103 from Junta de AndalucĂa, as well as by the Spanish Government through âJosĂ© Castillejoâ program from the âMinisterio de EducaciĂłn, Cultura y Deporteâ (I+D+i 2008-2011), and by the Austrian Science Fund (FWF) under Grant âElise-Richter V194-B20â
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