Mucosal and systemic T cell response in mice intragastrically infected with Neospora caninum tachyzoites

The murine model has been widely used to study the host immune response to Neospora caninum. However, in most studies, the intraperitoneal route was preferentially used to establish infection. Here, C57BL/6 mice were infected with N. caninum tachyzoites by the intragastric route, as it more closely resembles the natural route of infection through the gastrointestinal tract. The elicited T-cell mediated immune response was evaluated in the intestinal epithelium and mesenteric lymph nodes (MLN). Early upon the parasitic challenge, IL-12 production by conventional and plasmacytoid dendritic cells was increased in MLN. Accordingly, increased proportions and numbers of TCRαβ⁺CD8⁺IFN-γ⁺ lymphocytes were detected, not only in the intestinal epithelium and MLN, but also in the spleen of the infected mice. In this organ, IFN-γ-producing TCRαβ⁺CD4⁺ T cells were also found to increase in the infected mice, however later than CD8⁺ T cells. Interestingly, splenic and MLN CD4⁺CD25⁺ T cells sorted from infected mice presented a suppressive activity on in vitro T cell proliferation and cytokine production above that of control counterparts. These results altogether indicate that, by producing IFN-γ, TCRαβ⁺CD8⁺ cells contribute for local and systemic host protection in the earliest days upon infection established through the gastrointestinal tract. Nevertheless, they also provide substantial evidence for a parasite-driven reinforcement of T regulatory cell function which may contribute for parasite persistence in the host and might represent an additional barrier to overcome towards effective vaccination.     

Reducing NO2 Pollution over Urban Areas: Air Quality Modelling as a Fundamental Management Tool

Recently, specific air quality problems have been detected in the northern region of Portugal. The nitrogen oxide (NO₂) annual limit value has been surpassed at several air quality monitoring stations in the northern region, and according to European legislation, air quality plans must be designed and implemented to reduce those levels. The analysis of the air quality data from the stations concerning NO₂ exceedances indicates that traffic is responsible for an increase of more than 40?% compared with the urban background value. Specific measures to reduce NOx emissions have been selected and are related not only mainly to the traffic sector but also to the industrial and residential combustion sectors. The main objective of this study is to investigate the impact of the selected measures on the ambient levels of NO₂ in northern Portugal using a numerical modelling tool??The Air Pollution Model (TAPM). TAPM was applied over the study region using a 120?×?120-km² simulation domain and a spatial resolution of 4.8?×?4.8?km². The entire year of 2010 was simulated and was set as the base year to analyse the impact of the selected measures. Two scenarios have been defined and simulated: the base situation, which considers current NOx emissions, and the reduction scenario for which NOx emissions were re-estimated considering the implementation of the measures. The modelling results demonstrate a decrease of 4?C5???g?m^?3 in the annual NO₂ levels in the study region. Moreover, the implementation of the selected measures will allow compliance with the NO₂ annual limit values in three of the five air quality stations that measured levels surpassing those established by legislation. This situation demands additional measures that should be implemented at the local level and that particularly focus on the traffic sector.     

The influence of microclimate on foraging and sheltering behaviours of terrestrial isopods: Implications for soil carbon dynamics under climate change

In south east England climate change is predicted to include decreases in periodicity of rainfall events during summer, resulting in more, longer periods of drought. In many temperate regions these changes will affect foraging strategies of soil animals, including arthropod macro-decomposers such as terrestrial isopods. We investigated activity budgets under drier (50%) and moisture (90%) relative humidity conditions, for three species: Porcellio scaber, Oniscus asellus and Armadillidium vulgare, representing three families, which have different morphological adaptations to the terrestrial environment. In the drier environment all three species spent more time sheltering, less time feeding and less time in other activities. Costs of foraging were estimated by monitoring loss of body mass for 7 h. This loss was twice as high under the lower humidity regime. On the basis of morphological traits, two members of the Oniscidae: O. asellus and Philoscia muscorum, differing in eco-morphological strategies, were predicted to be more susceptible to desiccation than members of the Porcellionidae or Amadillidiidae. Members of the Oniscidae lost mass most quickly and also suffered higher mortality in the drier atmosphere. A cost of spending more time sheltering was that consumption of high quality food by Porcellio scaber was significantly reduced in the drier environment. The trade-off between energy gain by feeding and increased probability of survivorship by sheltering, is illustrated using an isopleth model. Changes in the extent to which the soil fauna will stimulate microbial metabolism and hence soil carbon dioxide emissions, under future conditions of climate change are predicted.     

Combinatorial electrochemistry: A highly parallel, optical screening method for discovery of better electrocatalysts

Combinatorial screening of electrochemical catalysts by current-voltage methods can be unwieldy for large sample sizes. By converting the ions generated in an electrochemical half-cell reaction to a fluorescence signal, the most active compositions in a large electrode array have been identified. A fluorescent acid-base indicator was used to image high concentrations of hydrogen ions, which were generated in the electrooxidation of methanol. A 645-member electrode array containing five elements (platinum, ruthenium, osmium, iridium, and rhodium), 80 binary, 280 ternary, and 280 quaternary combinations was screened to identify the most active regions of phase space. Subsequent "zoom" screens pinpointed several very active compositions, some in ternary and quaternary regions that were bounded by rather inactive binaries. The best catalyst, platinum(44)/ruthenium(41)/osmium(10)/iridium(5) (numbers in parentheses are atomic percent), was significantly more active than platinum(50)/ruthenium(50) in a direct methanol fuel cell operating at 60 degreesC, even though the latter catalyst had about twice the surface area of the former.     

Brominated compounds from marine sponges of the genus Aplysina and a compilation of their 13C NMR spectral data

Aplysina is the best representative genus of the family Aplysinidae. Halogenated substances are its main class of metabolites. These substances contribute greatly to the chemotaxonomy and characterization of the sponges belonging to this genus. Due to their pharmacological activities, these alkaloids are of special interest. The chemistry of halogenated substances and of the alkaloids has long been extensively studied in terrestrial organisms, while the number of marine organisms studied has just started to increase in the last decades. This review describes 101 halogenated substances from 14 species of Aplysina from different parts of the world. These substances can be divided into the following classes: bromotyramines (A), cavernicolins (B), hydroverongiaquinols (C), bromotyrosineketals (D), bromotyrosine lactone derivatives (E), oxazolidones (F), spiroisoxazolines (G), verongiabenzenoids (H), verongiaquinols (I), and dibromocyclohexadienes (J). A compilation of their (13)C NMR data is also part of the review. For this purpose 138 references were consulted.