282 research outputs found
Resilience of European beech forests (Fagus sylvatica L.) after fire in a global change context
Inoculação de bactérias diazotróficas e a produtividade de genótipos de cana-de-açúcar de ciclo médio-tardio.
Legacies, socio-economic and biophysical processes and drivers : the case of future forest cover expansion in the Polish Carpathians and Swiss Alps
Mountain forest areas are key for providing a
wide range of ecosystem services and are hot spots for land
use change processes, in particular, increase in forest cover
at the expense of mountain pastures and meadows.
Mountain forest systems in eastern and western Europe
have likely similar future socio-economic situations but
significantly different socio-economic history. Using a
scenario-based land use modelling approach (Dyna-CLUE
framework) we model three scenarios (trend, liberalisation
and self-sufficiency) of future land use in the Polish
Carpathians and the Swiss Alps, focussing on forest cover
change. We find that forest cover increase can be expected
to continue in European mountainous regions under all
likely scenarios, limited only by relatively strict policy
interventions. Biophysical factors, rather than socio-eco-
nomic ones, are key for defining the suitability for, and
therefore likely locations of future forest cover, but land
use legacy plays a very important role in the spatial pat-
terns of future forest cover, particularly in eastern Europe
Inoculação de bactérias diazotróficas e a produtividade de colmos de genótipos de cana-de-açúcar de ciclo precoce.
How robust are future projections of forest landscape dynamics? Insights from a systematic comparison of four forest landscape models
Projections of landscape dynamics are uncertain, partly due to uncertainties in model formulations. However, quantitative comparative analyses of forest landscape models are lacking. We conducted a systematic comparison of all forest landscape models currently applied in temperate European forests (LandClim, TreeMig, LANDIS-II, iLand). We examined the uncertainty of model projections under several future climate, disturbance, and dispersal scenarios, and quantified uncertainties by variance partitioning. While projections under past climate conditions were in good agreement with observations, uncertainty under future climate conditions was high, with between-model biomass differences of up to 200 t ha−1. Disturbances strongly influenced landscape dynamics and contributed substantially to uncertainty in model projections (~25–40% of observed variance). Overall, model differences were the main source of uncertainty, explaining at least 50% of observed variance. We advocate a more rigorous and systematic model evaluation and calibration, and a broader use of ensemble projections to quantify uncertainties in future landscape dynamics
Effect of dietary supplementation of Padauk (Pterocarpus soyauxii) leaf on high fat diet/streptozotocin induced diabetes in rats’ brain and platelets
Background
This study investigated the effects of Padauk leaf on brain malondialdehyde (MDA) content, acetylcholinesterase (AChE) activities, ectonucleotidases and adenosine deaminase (ADA) activities in the platelet of high fat diet and streptozotocin (STZ)-induced diabetic rats.
Methods
The animals were divided into six groups (n = 7): normal control rats; diabetic rats + high fat diet (HFD); diabetic rats + HFD + Metformin; diabetic rats + HFD + acarbose; diabetic rats + HFD + 10% Padauk leaf; normal rats + basal diet + 10% Padauk leaf. After 30 days of experiment comprising of acclimatization, dietary manipulation, pre-treatment with STZ and supplementation with Padauk leaf, the animals were sacrificed and the rats’ brain and blood were collected for subsequent analysis.
Results
The results demonstrated that the elevated MDA content and AChE activity in the diabetic rats were significantly reduced when compared with the control rats. Furthermore, the increased NTPDases, 5′-nucleotidase and ADA activities in the diabetic rats were significantly reduced when compared with the control rats.
Conclusion
This study demonstrated that Padauk leaf exhibited modulatory effects on purinergic and cholinergic enzymes involved in the prevention of platelet abnormality and consequent vascular complications in diabetic state
Anthocyanins restore behavioral and biochemical changes caused by streptozotocin-induced sporadic dementia of Alzheimer's type
Aims
The aim of this study was to analyze if the pre-administration of anthocyanin on memory and anxiety prevented the effects caused by intracerebroventricular streptozotocin (icv-STZ) administration-induced sporadic dementia of Alzheimer's type (SDAT) in rats. Moreover, we evaluated whether the levels of nitrite/nitrate (NOx), Na+,K+-ATPase, Ca2 +-ATPase and acethylcholinesterase (AChE) activities in the cerebral cortex (CC) and hippocampus (HC) are altered in this experimental SDAT.
Main methods
Male Wistar rats were divided in 4 different groups: control (CTRL), anthocyanin (ANT), streptozotocin (STZ) and streptozotocin + anthocyanin (STZ + ANT). After seven days of treatment with ANT (200 mg/kg; oral), the rats were icv-STZ injected (3 mg/kg), and four days later the behavior parameters were performed and the animals submitted to euthanasia.
Key findings
A memory deficit was found in the STZ group, but ANT treatment showed that it prevents this impairment of memory (P < 0.05). Our results showed a higher anxiety in the icv-STZ group, but treatment with ANT showed a per se effect and prevented the anxiogenic behavior induced by STZ. Our results reveal that the ANT treatment (100 μM) tested displaces the specific binding of [3H] flunitrazepam to the benzodiazepinic site of GABAA receptors. AChE, Ca+-ATPase activities and NOx levels were found to be increased in HC and CC in the STZ group, which was attenuated by ANT (P < 0.05). STZ decreased Na+,K+-ATPase activity and ANT was able to prevent these effects (P < 0.05).
Significance
In conclusion, these findings demonstrated that ANT is able to regulate ion pump activity and cholinergic neurotransmission, as well as being able to enhance memory and act as an anxiolytic compound in animals with SDAT
Inoculação de bactérias diazotróficas e produtividade de genótipos de cana-de-açúcar.
O objetivo deste trabalho foi avaliar o efeito da inoculação de bactérias diazotróficas sobre a produtividade de colmos de cana-de-açúcar
A standard protocol for reporting species distribution models
Species distribution models (SDMs) constitute the most common class of models across ecology, evolution and conservation. The advent of ready-to-use software packages and increasing availability of digital geoinformation have considerably assisted the application of SDMs in the past decade, greatly enabling their broader use for informing conservation and management, and for quantifying impacts from global change. However, models must be fit for purpose, with all important aspects of their development and applications properly considered. Despite the widespread use of SDMs, standardisation and documentation of modelling protocols remain limited, which makes it hard to assess whether development steps are appropriate for end use. To address these issues, we propose a standard protocol for reporting SDMs, with an emphasis on describing how a study's objective is achieved through a series of modeling decisions. We call this the ODMAP (Overview, Data, Model, Assessment and Prediction) protocol, as its components reflect the main steps involved in building SDMs and other empirically-based biodiversity models. The ODMAP protocol serves two main purposes. First, it provides a checklist for authors, detailing key steps for model building and analyses, and thus represents a quick guide and generic workflow for modern SDMs. Second, it introduces a structured format for documenting and communicating the models, ensuring transparency and reproducibility, facilitating peer review and expert evaluation of model quality, as well as meta-analyses. We detail all elements of ODMAP, and explain how it can be used for different model objectives and applications, and how it complements efforts to store associated metadata and define modelling standards. We illustrate its utility by revisiting nine previously published case studies, and provide an interactive web-based application to facilitate its use. We plan to advance ODMAP by encouraging its further refinement and adoption by the scientific community
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