684 research outputs found
Pseudomonas fluorescens Cells' Recovery after Exposure to BAC and DBNPA Biocides
A proper assessment of the effects of biocides on bacterial cells is key to the prevention of antimicrobial resistance and the implementation of suitable biocidal programmes. It is particularly relevant regarding the ability of dead-labelled cells to recover their functional processes once the biocide is removed. In the present work, we studied how Pseudomonas fluorescens cells previously exposed to different concentrations of BAC (benzalkonium chloride) and DBNPA (2,2-Dibromo-3-nitrilopropionamide) behave upon the restoration of optimum growth conditions. The following indicators were evaluated: culturability, membrane integrity, metabolic activity (resazurin), cellular energy (ATP), and cell structure and morphology (transmission electron microscopy (TEM)). The results demonstrated that cells previously labelled as ‘dead’ recovered to a greater extent in all indicators. Only cells previously exposed to BAC at 160 mg/L (concentration above the MBC) showed significant reductions on all the evaluated indicators. However, the obtained values were much higher than the ‘death’ thresholds found for the autoclaved cells. This suggests that cells exposed to this concentration take more time to rebuild their functional processes. The recovery of DBNPA-treated cells did not seem to be related to the biocide concentration. Finally, a reflection on what kind of cells were able to recover (remaining cells below the detection limit and/or dormant cells) is also presented
Policy development for environmental licensing and biodiversity offsets in Latin America
Attempts to meet biodiversity goals through application of the mitigation hierarchy have gained wide traction globally with
increased development of public policy, lending standards, and corporate practices. With interest in biodiversity offsets
increasing in Latin America, we seek to strengthen the basis for policy development through a review of major
environmental licensing policy frameworks in Argentina, Brazil, Chile, Colombia, Mexico, Peru and Venezuela. Here we
focused our review on an examination of national level policies to evaluate to which degree current provisions promote
positive environmental outcomes. All the surveyed countries have national-level Environmental Impact Assessment laws or
regulations that cover the habitats present in their territories. Although most countries enable the use of offsets only Brazil,
Colombia, Mexico and Peru explicitly require their implementation. Our review has shown that while advancing quite
detailed offset policies, most countries do not seem to have strong requirements regarding impact avoidance. Despite this
deficiency most countries have a strong foundation from which to develop policy for biodiversity offsets, but several issues
require further guidance, including how best to: (1) ensure conformance with the mitigation hierarchy; (2) identify the most
environmentally preferable offsets within a landscape context; (3) determine appropriate mitigation replacement ratios; and
(4) ensure appropriate time and effort is given to monitor offset performance
Modelos acoplados do IPCC-AR4 e o gradiente meridional de temperatua da superficie do mar no atlântico tropical : relaçoes com a precipitaçao no norte do nordeste do Brasil
Este artigo mostra como três modelos acoplados do Intergovernmental on Panel Climate Change - (IPCC-AR4), o FGOALS1. 0G – LASG do Institute of Atmospheric Physics of China, o GISSER da National Aeronautics Space Admnistration (NASA) e o GFDL_CM2 da National Oceanic and Atmospheric Administration (NOAA), simularam a variabilidade do gradiente meridional de Temperatura da Superfície do Mar (TSM), entre os meses de fevereiro a maio, no Atlântico Tropical (1901-1999). A precipitação durante a estação chuvosa (fevereiro a maio) no setor norte do Nordeste do Brasil (NEB) foi também analisada pelos três modelos e comparada com as observações. Os modelos GISSER e FGOALS1.0G mostraram melhor desempenho na simulação do sinal do gradiente meridional de TSM no Atlântico Tropical para o período de 1901 a 1999. Destaca-se que os modelos apresentaram um melhor desempenho na simulação da tendência decadal, conseguindo explicar entre 50% a 80% da variabilidade do gradiente, com a TSM do setor sul sendo mais bem simulada
Physiological and biochemical performance of almond trees under deficit irrigation
The almond tree is generally recognized as drought-tolerant, though it depends on water resources to achieve
high yields. During the summer months of two consecutive years, several physiological and biochemical parameters
were observed, to understand the almond tree’s seasonal sensitivity and behavior under different irrigation
strategies based on crop evapotranspiration (ETc): T100 optimal water requirement regime (applying
100% ETc); T70 and T35 sustained deficit irrigation regimes (applying 70% and 35% ETc); T100-35 regulated
deficit irrigation regime (reducing the application to 35% ETc during fruit filling stage); and T0 (rainfed). The
total leaf chlorophyll and carotenoid reduction in T0 and T35 treatments was significant compared to T100-35.
Leaf soluble proteins and total soluble sugar contents were significantly higher in non-irrigated trees compared
to other treatments, while the starch content showed the opposite trend. Rainfed trees were under obvious water
stress, displaying the lowest values for relative water content (RWC), stomatal conductance (gs), photosynthetic
rate (A), and transpiration rate (E), and the highest for intrinsic water use efficiency (A/gs). Plant hormones
(ABA and IAA) generally accumulated more in non-irrigated trees. The almond tree has been confirmed as a
drought-tolerant species, and when water is scarce, reducing the water application to 35% ETc during fruit filling
stage, results in no yield losses, and the plant status remains unstressed. However, to get the maximum crop
potential, in years and areas where water is not restricted, full irrigation requirements have been shown to boost
almond tree performance.IP acknowledges the financial support provided by the FCTPortuguese
Foundation for Science and Technology (SFRH/BD/52539/
2014), under the Doctoral Programme “Agricultural Production Chains
– from fork to farm” (PD/00122/2012). This work was also supported
by National Funds by FCT - Portuguese Foundation for Science and
Technology, under the project UID/AGR/04033/2019 and by the project
PRODER “Estratégias Integradas para o aumento da produtividade da
amendoeira em Trás-os-Montes, nº 54611. 2014 a 2018. The authors wish
to acknowledge the help and support provided during field and laboratory
work by Ana Monteiro, Cristiana Teixeira, Helena Ferreira, Ivo
Oliveira, Linton Dinis, Sara Bernardo, Silvia Afonso, and Silvina Morais,
and thank João Santos and Chenyao Yang for help with climate data.info:eu-repo/semantics/publishedVersio
Altered glucose homeostasis and hepatic function in obese mice deficient for both kinin receptor genes
The Kallikrein-Kinin System (KKS) has been implicated in several aspects of metabolism, including the regulation of glucose homeostasis and adiposity. Kinins and des-Arg-kinins are the major effectors of this system and promote their effects by binding to two different receptors, the kinin B2 and B1 receptors, respectively. To understand the influence of the KKS on the pathophysiology of obesity and type 2 diabetes (T2DM), we generated an animal model deficient for both kinin receptor genes and leptin (obB1B2KO). Six-month-old obB1B2KO mice showed increased blood glucose levels. Isolated islets of the transgenic animals were more responsive to glucose stimulation releasing greater amounts of insulin, mainly in 3-month-old mice, which was corroborated by elevated serum C-peptide concentrations. Furthermore, they presented hepatomegaly, pronounced steatosis, and increased levels of circulating transaminases. This mouse also demonstrated exacerbated gluconeogenesis during the pyruvate challenge test. The hepatic abnormalities were accompanied by changes in the gene expression of factors linked to glucose and lipid metabolisms in the liver. Thus, we conclude that kinin receptors are important for modulation of insulin secretion and for the preservation of normal glucose levels and hepatic functions in obese mice, suggesting a protective role of the KKS regarding complications associated with obesity and T2DM
Angiotensin-converting enzyme inhibitor protects against cisplatin nephrotoxicity by modulating kinin B1 receptor expression and aminopeptidase P activity in mice
Cisplatin is a highly effective chemotherapeutic agent. However, its use is limited by nephrotoxicity. Enalapril is an angiotensin I-converting enzyme inhibitor used for the treatment of hypertension, mainly through the reduction of angiotensin II formation, but also through the increase of kinins half-life. Kinin B1 receptor is associated with inflammation and migration of immune cells into the injured tissue. We have previously shown that the deletion or blockage of kinin B1 and B2 receptors can attenuate cisplatin nephrotoxicity. In this study, we tested enalapril treatment as a tool to prevent cisplatin nephrotoxicity. Male C57Bl/6 mice were divided into 3 groups: control group; cisplatin (20 mg/kg i.p) group; and enalapril (1.5 mg;kg i.p) + cisplatin group. The animals were treated with a single dose of cisplatin and euthanized after 96 h. Enalapril was able to attenuate cisplatin-induced increase in creatinine and urea, and to reduce tubular injury and upregulation of apoptosis-related genes, as well as inflammatory cytokines in circulation and kidney. The upregulation of B1 receptor was blocked in enalapril + cisplatin group. Carboxypeptidase M expression, which generates B1 receptor agonists, is blunted by cisplatin + enalapril treatment. The activity of aminopeptidase P, a secondary key enzyme able to degrade kinins, is restored by enalapril treatment. These findings were confirmed in mouse renal epithelial tubular cells, in which enalaprilat (5 μM) was capable of decreasing tubular injury and inflammatory markers. We treated mouse renal epithelial tubular cells with cisplatin (100 μM), cisplatin+enalaprilat and cisplatin+enalaprilat+apstatin (10 μM). The results showed that cisplatin alone decreases cell viability, cisplatin plus enalaprilat is able to restore cell viability, and cisplatin plus enalaprilat and apstatin decreases cell viability. In the present study, we demonstrated that enalapril prevents cisplatin nephrotoxicity mainly by preventing the upregulation of B1 receptor and carboxypeptidase M and the increased concentrations of kinin peptides through aminopeptidase activity restoration
Predicting olive phenology in Portugal in a warming climate
Prediction of flowering of olive trees should account for
chilling requirements, using an appropriate chilling unit
for the accounting of chilling accumulation. After chilling
requirements are satisfied, dormancy break takes place.
Thereafter, the trees enter the forcing phase, in which
the thermal time approach is used, but an appropriate
base temperature must be determined. Such a model was
developed, calibrated and validated for many olive cultivars
(De Melo-Abreu et al., 2004).
After flowering, the occurrence of developmental stages
may be predicted using a thermal time approach, but
for warm regions a saw-tooth model, which is a model
that reduces the effect of supra-optimal temperatures, is
mandatory (Garcia-Huidobro et al., :1.982).
According to the simulations of the model HadCM3,
developed by the Hadley Centre, global climate warming
will result in average temperature anomalies in winter, in
Continental Portugal, of about 2°C, in SRES scenarios 81
and 82, 3°C in scenario A2, and 4 °C in scenario A:tFI, by the
end of XXI century. (Miranda et al., 2006).
In this study, we discuss the prediction of flowering and
subsequent phenological stages and calculate and map
the times of occurrence of flowering under three warming
scenarios. No flowering or abnormal flowering events are
also predicted.Portuguese Foundation for Science and Technology (FCT) under Project Futurolive (PTDC/AGR-AAM/:1.04562/2008)
Rotational Surfaces in and Solutions in the Nonlinear Sigma Model
The Gauss map of non-degenerate surfaces in the three-dimensional Minkowski
space are viewed as dynamical fields of the two-dimensional O(2,1) Nonlinear
Sigma Model. In this setting, the moduli space of solutions with rotational
symmetry is completely determined. Essentially, the solutions are warped
products of orbits of the 1-dimensional groups of isometries and elastic curves
in either a de Sitter plane, a hyperbolic plane or an anti de Sitter plane. The
main tools are the equivalence of the two-dimensional O(2,1) Nonlinear Sigma
Model and the Willmore problem, and the description of the surfaces with
rotational symmetry. A complete classification of such surfaces is obtained in
this paper. Indeed, a huge new family of Lorentzian rotational surfaces with a
space-like axis is presented. The description of this new class of surfaces is
based on a technique of surgery and a gluing process, which is illustrated by
an algorithm.Comment: PACS: 11.10.Lm; 11.10.Ef; 11.15.-q; 11.30.-j; 02.30.-f; 02.40.-k. 45
pages, 11 figure
Transformações do espaço habitacional ocorridas na arquitetura brasileira do século XIX
Depois de referências à arquitetura colonial (inclusive no exame de modelos vernaculares portugueses, da contribuição indígena e da adaptação a condições climáticas, ao isolamento geográfico e a padrões segregacionistas de comportamento), o autor descreve os principais traços do padrão difuso de residência rural, assim como de seus equivalentes urbanos. O Ecletismo - com suas raízes externas - é apontado como o principal vetor de transformações, da segunda metade do século XIX até a 1.0 Guerra Mundial
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