640 research outputs found
Improving management decisions in portuguese forests through fire behaviour modeling: guidelines to support a sustainable landscape
PosterUnderstanding wildfire behavior at the landscape-level is critical to address wildfire
impacts in Portuguese forest management planning.
Thus, fire spread was simulated in three forested landscape to assist forest managers in
identifying high-risk areas for actively integrating stand-level fuel treatments with explicit
landscape-level management planning and develop fire prevention priorities.
Specifically, several modeling applications to detect significant fire-landscape
interactions between stand-level features and fire behavior were fitted to classify
Portuguese forests to fire risk levels and create guidelines to support hazard-reduction
silvicultural practiceN/
Effect of methylprednisolone on perivascular pulmonary edema, inflammatory infiltrate, VEGF and TGF-beta immunoexpression in the remaining lungs of rats after left pneumonectomy
Pneumonectomy is associated with high rates of morbimortality, with postpneumonectomy pulmonary edema being one of the leading causes. An intrinsic inflammatory process following the operation has been considered in its physiopathology. The use of corticosteroids is related to prevention of this edema, but no experimental data are available to support this hypothesis. We evaluated the effect of methylprednisolone on the remaining lungs of rats submitted to left pneumonectomy concerning edema and inflammatory markers. Forty male Wistar rats weighing 300 g underwent left pneumonectomy and were randomized to receive corticosteroids or not. Methylprednisolone at a dose of 10 mg/kg was given before the surgery. After recovery, the animals were sacrificed at 48 and 72 h, when the pO2/FiO2 ratio was determined. Right lung perivascular edema was measured by the index between perivascular and vascular area and neutrophil density by manual count. Tissue expression of vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-β) were evaluated by immunohistochemistry light microscopy. There was perivascular edema formation after 72 h in both groups (P = 0.0031). No difference was observed between operated animals that received corticosteroids and those that did not concerning the pO2/FiO2 ratio, neutrophil density or TGF-β expression. The tissue expression of VEGF was elevated in the animals that received methylprednisolone both 48 and 72 h after surgery (P = 0.0243). Methylprednisolone was unable to enhance gas exchange and avoid an inflammatory infiltrate and TGF-β expression also showed that the inflammatory process was not correlated with pulmonary edema formation. However, the overexpression of VEGF in this group showed that methylprednisolone is related to this elevation
Reduced Anxiety and Depression-Like Behaviours in the Circadian Period Mutant Mouse Afterhours
Disruption of the circadian rhythm is a key feature of bipolar disorder. Variation in genes encoding components of the molecular circadian clock has been associated with increased risk of the disorder in clinical populations. Similarly in animal models, disruption of the circadian clock can result in altered mood and anxiety which resemble features of human mania; including hyperactivity, reduced anxiety and reduced depression-like behaviour. One such mutant, after hours (Afh), an ENU-derived mutant with a mutation in a recently identified circadian clock gene Fbxl3, results in a disturbed (long) circadian rhythm of approximately 27 hours.Anxiety, exploratory and depression-like behaviours were evaluated in Afh mice using the open-field, elevated plus maze, light-dark box, holeboard and forced swim test. To further validate findings for human mania, polymorphisms in the human homologue of FBXL3, genotyped by three genome wide case control studies, were tested for association with bipolar disorder.Afh mice showed reduced anxiety- and depression-like behaviour in all of the behavioural tests employed, and some evidence of increased locomotor activity in some tests. An analysis of three separate human data sets revealed a gene wide association between variation in FBXL3 and bipolar disorder (P = 0.009).Our results are consistent with previous studies of mutants with extended circadian periods and suggest that disruption of FBXL3 is associated with mania-like behaviours in both mice and humans
Effects of pneumonectomy on nitric oxide synthase expression and perivascular edema in the remaining lung of rats
Pneumonectomy is associated with high mortality and high rates of complications. Postpneumonectomy pulmonary edema is one of the leading causes of mortality. Little is known about its etiologic factors and its association with the inflammatory process. The purpose of the present study was to evaluate the role of pneumonectomy as a cause of pulmonary edema and its association with gas exchange, inflammation, nitric oxide synthase (NOS) expression and vasoconstriction. Forty-two non-specific pathogen-free Wistar rats were included in the study. Eleven animals died during or after the procedure, 21 were submitted to left pneumonectomy and 10 to sham operation. These animals were sacrificed after 48 or 72 h. Perivascular pulmonary edema was more intense in pneumonectomized rats at 72 h (P = 0.0131). Neutrophil density was lower after pneumonectomy in both groups (P = 0.0168). There was higher immunohistochemical expression of eNOS in the pneumonectomy group (P = 0.0208), but no statistically significant difference in the expression of iNOS. The lumen-wall ratio and pO2/FiO2 ratio did not differ between the operated and sham groups after pneumonectomy. Left pneumonectomy caused perivascular pulmonary edema with no elevation of immunohistochemical expression of iNOS or neutrophil density, suggesting the absence of correlation with the inflammatory process or oxidative stress. The increased expression of eNOS may suggest an intrinsic production of NO without signs of vascular reactivity.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNP
Undamning the Douro river catchment: a stepwise approach for prioritizing dam removal
Dams provide water supply, flood protection, and hydropower generation benefits, but
also harm native species by altering the natural flow regime, and degrading the aquatic and riparian
habitats. In the present study, which comprised the Douro River basin located in the North of
Portugal, the cost-benefit assessment of dams was based upon a balance between the touristic
benefits of a dammed Douro, and the ecological benefits of less fragmented Douro sub-catchments.
Focused on four sub-catchments (Sabor, Tâmega, Côa and Corgo), a probabilistic stream connectivity
model was developed and implemented to recommend priorities for dam removal, where this action
could significantly improve the movement of potadromous fish species along the local streams.
The proposed model accounts for fish movement across the dam or weir (permeability), which
is a novel issue in connectivity models. However, before any final recommendation on the fate
of a dam or weir, the connectivity results will be balanced with other important socio-economic
interests. While implementing the connectivity model, an inventory of barriers (dams and weirs)
was accomplished through an observation of satellite images. Besides identification and location of
any obstacles, the inventory comprised the compilation of data on surrounding land use, reservoir
water use, characteristics of the riparian gallery, and permeability conditions for fish, among others.
All this information was stored in a geospatial dataset that also included geographical information
on the sub-catchment drainage network. The linear (drainage network) and point (barriers) source
data were processed in a computer program that provided or returned numbers for inter-barrier
stream lengths (habitat), and the barrier permeability. These numbers were finally used in the
same computer program to calculate a habitat connector index, and a link improvement index,
used to prioritize dam removal based upon structural connectivity criteria. The results showed
that habitat patch connectivity in the Sabor, Tâmega and Côa sub-catchments is not dramatically
affected by the installed obstacles, because most link improvement values were generally low. For the
opposite reason, in the Corgo sub-catchment, obstacles may constitute a relatively higher limitation
to connectivity, and in this case the removal of eight obstacles could significantly improve this
connectivity. Using the probabilistic model of structural connectivity, it was possible to elaborate
a preliminary selection of dams/weirs that critically limit stream connectivity, and that will be the
focus of field hydraulic characterization to precisely determine fish movement along the associated
river stretches. Future work will also include the implementation of a multi-criteria decision support
system for dam removal or mitigation of the critical structures, as well to define exclusion areas for
additional obstaclesinfo:eu-repo/semantics/publishedVersio
Linking sintering stresses to nano modification in the microstructure of BaLa4Ti4O15 by transmission electron microscopy
High quality factor and a temperature stable resonant frequency make BaLa 4 Ti 4 O 15 (BLT) ceramics attractive materials for microwave applications. Aiming to exploit the effects of external stresses on the development of textured and anisotropic microstructures to optimise MW properties, the influence of applied external pressure during sintering of BLT ceramics is analysed. HRTEM and geometric phase analysis (GPA) showed that stresses applied during sintering, trigger the nucleation and growth of faults hypothesised to be due to the errors in the AO 3 layer (basal plane) stacking sequence of the hexagonal perovskite structure. The results reveal a strong correlation between the high concentration of structural defects and the development of anisotropic microstructures, which tune the properties of BLT. Stresses applied during sintering are therefore a promising tool to design material properties
The GOBLET training portal: A global repository of bioinformatics training materials, courses and trainers
Summary: Rapid technological advances have led to an explosion of biomedical data in recent years. The pace of change has inspired new collaborative approaches for sharing materials and resources to help train life scientists both in the use of cutting-edge bioinformatics tools and databases and in how to analyse and interpret large datasets. A prototype platform for sharing such training resources was recently created by the Bioinformatics Training Network (BTN). Building on this work, we have created a centralized portal for sharing training materials and courses, including a catalogue of trainers and course organizers, and an announcement service for training events. For course organizers, the portal provides opportunities to promote their training events; for trainers, the portal offers an environment for sharing materials, for gaining visibility for their work and promoting their skills; for trainees, it offers a convenient one-stop shop for finding suitable training resources and identifying relevant training events and activities locally and worldwide
Local wind speed forecasting based on WRF-HDWind coupling
[EN] Wind speed forecasts obtained by Numerical Weather Prediction models are limited for fine interpretation in
heterogeneous terrain, in which different roughnesses and orographies occur. This limitation is derived from the
use of low-resolution and grid-box averaged data. In this paper a dynamical downscaling method is presented to
increase the local accuracy of wind speed forecasts. The proposed method divides the wind speed forecasting
into two steps. In the first one, the mesoscale model WRF (Weather Research and Forecasting) is used for getting
wind speed forecasts at specific points of the study domain. On a second stage, these values are used for feeding
the HDWind microscale model. HDWind is a local model that provides both a high-resolution wind field that
covers the entire study domain and values of wind speed and direction at very located points. As an example of
use of the proposed method, we calculate a high-resolution wind field in an urban-interface area from Badajoz, a
South-West Spanish city located near the Portugal border. The results obtained are compared with the values
read by a weathervane tower of the Spanish State Meteorological Agency (AEMET) in order to prove that the
microscale model improves the forecasts obtained by the mesoscale model
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