Measurements of differential cross sections of Z/gamma* plus jets plus X events in p(p)over-bar collisions at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cross-reactivity between antigens from Amblyomma cajennense and A-hebraeum (Acari : Ixodidae)

Laboratory animals exposed to feeding ticks develop resistance which is reflected by a decline in tick engorgement weight, egg-laying by adults and reduced egg viability. Serum antibodies from these hosts and their reaction with tick antigens have been detected by different methods, including precipitation techniques, immunofluorescent techniques, ELISA and Western blots. However, little is known about the effects of antibodies on ticks that engorge on resistant hosts, or which tissues of the tick body are possibly immunogenic. Some researchers, using immunohistochemistry, have detected host antibodies in the gut, salivary glands and haemolymph of ticks engorged on resistant animals. The same technique has helped considerably in determining antigenic sites or antibody targets in other arthropods. Consequently, immunohistochemistry techniques were used in this study to detect cross-reactivity between sera raised against Amblyomma cajennense (Fabricius, 1787) with Amblyomma hebraeum (Koch, 1844), and vice versa. The results show the existence of shared antigens between the 2 tick species. In general, our results point more to a 1-way cross-reactivity of A. hebraeum with A. cajennense than a reciprocal cross-reactivity, suggesting that A. hebraeum is more immunogenic than A. cajennense.

The small x behavior of the gluon structure function from total cross-sections

Within a QCD-based eikonal model with a dynamical infrared gluon mass scale we discuss how the small x behavior of the gluon distribution function at moderate Q 2 is directly related to the rise of total hadronic cross-sections. In this model the rise of total cross-sections is driven by gluon-gluon semihard scattering processes, where the behavior of the small x gluon distribution function exhibits the power law xg(x, Q 2) = h(Q 2)x( -∈). Assuming that the Q 2 scale is proportional to the dynamical gluon mass one, we show that the values of h(Q 2) obtained in this model are compatible with an earlier result based on a specific nonperturbative Pomeron model. We discuss the implications of this picture for the behavior of input valence-like gluon distributions at low resolution scales. © 2008 World Scientific Publishing Company.

Poverty dynamics in Costa Rica with panel data from cross-sections

Includes bibliography

Development and characterization of microsatellite loci of microglanis cottoides (siluriformes: pseudopimelodidae) and cross-species amplification

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Soft edge of hadron scattering and minijet models for the total and inelastic pp cross sections at LHC and beyond

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Critical behavior in a cross-situational lexicon learning scenario

The associationist account for early word learning is based on the co-occurrence between referents and words. Here we introduce a noisy cross-situational learning scenario in which the referent of the uttered word is eliminated from the context with probability gamma, thus modeling the noise produced by out-of-context words. We examine the performance of a simple associative learning algorithm and find a critical value of the noise parameter gamma(c) above which learning is impossible. We use finite-size scaling to show that the sharpness of the transition persists across a region of order tau(-1/2) about gamma(c), where tau is the number of learning trials, as well as to obtain the learning error (scaling function) in the critical region. In addition, we show that the distribution of durations of periods when the learning error is zero is a power law with exponent -3/2 at the critical point. Copyright (C) EPLA, 2012

Eight anonymous nuclear loci for the squamate antbird (Myrmeciza squamosa), cross-amplifiable in other species of typical antbirds (Aves, Thamnophilidae)

Typical antbirds (similar to 209 species) represent a diverse radiation of Neotropical birds that includes many species of conservation concern. Here we present eight anonymous nuclear loci designed for the squamate antbird Myrmeciza squamosa, a species endemic to the Atlantic Forest of Brazil. We also show that those anonymous nuclear loci are amplifiable in a number of other typical antbird species from related genera (Myrmeciza, Percnostola, Gymnocichla, Myrmoborus, Pyriglena and Formicivora), including three threatened species (Myrmeciza ruficauda, Formicivora littoralis, and Pyriglena atra). Those markers will be useful not only to help management of threatened species of typical antbirds, but also to explore their evolutionary histories, both at intra and interspecific levels.

Investigation of the optical absorption of a magnetic colloid from the thermal to the electronic time-scale regime: measurement of the free-carrier absorption cross-section

The free-carrier absorption cross-section sigma of a magnetic colloid composed of magnetite nanoparticles dispersed in oil is obtained by using the Z-scan technique in different experimental conditions of the laser beam. We show that it is possible to obtain sigma with picosecond pulsed and millisecond chopped beams with pulse frequencies smaller than about 30 Hz. For higher pulse frequencies, the heating of the colloidal system triggers the appearance of the Soret effect. This effect artificially increases the value of sigma calculated from the experimental results. The limits of the different experimental setups are discussed. (C) 2012 Optical Society of America

Effects of moderate electrical stimulation on reactive species production by primary rat skeletal muscle cells: Cross talk between superoxide and nitric oxide production

The effects of a moderate electrical stimulation on superoxide and nitric oxide production by primary cultured skeletal muscle cells were evaluated. The involvement of the main sites of these reactive species production and the relationship between superoxide and nitric oxide production were also examined. Production of superoxide was evaluated by cytochrome c reduction and dihydroethidium oxidation assays. Electrical stimulation increased superoxide production after 1?h incubation. A xanthine oxidase inhibitor caused a partial decrease of superoxide generation and a significant amount of mitochondria-derived superoxide was also observed. Nitric oxide production was assessed by nitrite measurement and by using 4,5-diaminofluorescein diacetate (DAF-2-DA) assay. Using both methods an increased production of nitric oxide was obtained after electrical stimulation, which was also able to induce an increase of iNOS content and NF-?B activation. The participation of superoxide in nitric oxide production was investigated by incubating cells with DAF-2-DA in the presence or absence of electrical stimulation, a superoxide generator system (xanthinexanthine oxidase), a mixture of NOS inhibitors and SOD-PEG. Our data show that the induction of muscle contraction by a moderate electrical stimulation protocol led to an increased nitric oxide production that can be controlled by superoxide generation. The cross talk between these reactive species likely plays a role in exercise-induced maintenance and adaptation by regulating muscular glucose metabolism, force of contraction, fatigue, and antioxidant systems activities. J. Cell. Physiol. 227: 25112518, 2012. (c) 2011 Wiley Periodicals, Inc.

Effect of enzymatic treatment on the cross-flow microfiltration of acai pulp: Analysis of the fouling and recovery of phytochemicals

This study aimed to investigate the effects of pectinase enzyme treatment of acai pulp on cross-flow microfiltration (CFMF) performance and on phytochemical and functional characteristics of their compounds. Analyses of fouling mechanisms were carried out through resistance in series and blocking in law models. The enzymatic treatment was conducted using Ultrazym(R) AFPL (Novozymes A/S) at 500 mg kg(-1) of acai pulp for 30 min at 35 degrees C. Before microfiltrations, untreated and enzyme-treated acai pulps were previously diluted in distilled water (1:3; w/v). CFMFs were conducted using commercial alpha-alumina (alpha-Al2O3) ceramic membranes (Andritz AG, Austria) of 0.2 mu m and 0.8 mu m pore sizes, and 0.0047 m(2) of filtration area. The microfiltration unit was operated in batch mode for 120 min at 25 degrees C and the fluid-dynamic conditions were transmembrane pressure of Delta P = 100 kPa and cross-flow velocity of 3 m s(-1) in turbulent flow. The highest values of permeate flux and accumulated permeate volume were obtained using enzyme-treated pulp and 0.2 mu m pore size membranes with steady flux values exceeding 100 L h(-1) m(-2). For the 0.8 mu m pore size membrane, the estimated total resistance after the microfiltration of enzyme-treated acai pulp was 21% lower than the untreated pulp, and for the 0.2 mu m pore size membrane, it was 18%. Cake filtration was the dominant mechanism in the early stages of most of the CFMF processes. After approximately 20 min, however, intermediate pore blocking and complete pore blocking contributed to the overall fouling mechanisms. The reduction of the antioxidant capacity of the permeates obtained after microfiltration of the enzyme-treated pulp was higher (p < 0.01) than that obtained using untreated pulp. For total polyphenols, on the contrary, the permeates obtained after microfiltration of the enzyme-treated pulp showed a lower mean reduction (p < 0.01) than those from the untreated pulp. The results show that the enzymatic treatment had a positive effect on the CFMF process of acai pulp. (C) 2012 Elsevier Ltd. All rights reserved.

Cutting Edge: Brazilian Pemphigus Foliaceus Anti-Desmoglein 1 Autoantibodies Cross-React with Sand Fly Salivary LJM11 Antigen

The environmental factors that contribute to the development of autoimmune diseases are largely unknown. Endemic pemphigus foliaceus in humans, known as Fogo Selvagem (FS) in Brazil, is mediated by pathogenic IgG4 autoantibodies against desmoglein 1 (Dsg1). Clusters of FS overlap with those of leishmaniasis, a disease transmitted by sand fly (Lutzomyia longipalpis) bites. In this study, we show that salivary Ags from the sand fly, and specifically the LJM11 salivary protein, are recognized by FS Abs. Anti-Dsg1 monoclonal autoantibodies derived from FS patients also cross-react with LJM11. Mice immunized with LJM11 generate anti-Dsg1 Abs. Thus, insect bites may deliver salivary Ags that initiate a cross-reactive IgG4 Ab response in genetically susceptible individuals and lead to subsequent FS. Our findings establish a clear relationship between an environmental, noninfectious Ag and the development of potentially pathogenic autoantibodies in an autoimmune disease. The Journal of Immunology, 2012, 189: 1535-1539.

Extensive cross-talk and global regulators identified from an analysis of the integrated transcriptional and signaling network in Escherichia coli

To understand the regulatory dynamics of transcription factors (TFs) and their interplay with other cellular components we have integrated transcriptional, protein-protein and the allosteric or equivalent interactions which mediate the physiological activity of TFs in Escherichia coli. To study this integrated network we computed a set of network measurements followed by principal component analysis (PCA), investigated the correlations between network structure and dynamics, and carried out a procedure for motif detection. In particular, we show that outliers identified in the integrated network based on their network properties correspond to previously characterized global transcriptional regulators. Furthermore, outliers are highly and widely expressed across conditions, thus supporting their global nature in controlling many genes in the cell. Motifs revealed that TFs not only interact physically with each other but also obtain feedback from signals delivered by signaling proteins supporting the extensive cross-talk between different types of networks. Our analysis can lead to the development of a general framework for detecting and understanding global regulatory factors in regulatory networks and reinforces the importance of integrating multiple types of interactions in underpinning the interrelationships between them.

What drives the seasonality of photosynthesis across the Amazon basin? A cross-site analysis of eddy flux tower measurements from the Brasil flux network

We investigated the seasonal patterns of Amazonian forest photosynthetic activity, and the effects thereon of variations in climate and land-use, by integrating data from a network of ground-based eddy flux towers in Brazil established as part of the ‘Large-Scale Biosphere Atmosphere Experiment in Amazonia’ project. We found that degree of water limitation, as indicated by the seasonality of the ratio of sensible to latent heat flux (Bowen ratio) predicts seasonal patterns of photosynthesis. In equatorial Amazonian forests (5◦ N–5◦ S), water limitation is absent, and photosynthetic fluxes (or gross ecosystem productivity, GEP) exhibit high or increasing levels of photosynthetic activity as the dry season progresses, likely a consequence of allocation to growth of new leaves. In contrast, forests along the southern flank of the Amazon, pastures converted from forest, and mixed forest-grass savanna, exhibit dry-season declines in GEP, consistent with increasing degrees of water limitation. Although previous work showed tropical ecosystem evapotranspiration (ET) is driven by incoming radiation, GEP observations reported here surprisingly show no or negative relationships with photosynthetically active radiation (PAR). Instead, GEP fluxes largely followed the phenology of canopy photosynthetic capacity (Pc), with only deviations from this primary pattern driven by variations in PAR. Estimates of leaf flush at three

Influence of climate changes on cross allergies: possible involvement of pollen transglutaminase

Allergies are a complex of symptoms derived from altered IgE-mediated reactions of the immune system towards substances known as allergens. Allergic sensibilization can be of food or respiratory origin and, in particular, apple and hazelnut allergens have been identified in pollens or fruits. Allergic cross-reactivity can occur in a patient reacting to similar allergens from different origins, justifying the research in both systems as in Europe a greater number of people suffers from apple fruit allergy, but little evidence exists about pollen. Apple fruit allergies are due to four different classes of allergens (Mal d 1, 2, 3, 4), whose allergenicity is related both to genotype and tissue specificity; therefore I have investigated their presence also in pollen at different time of germination to clarify the apple pollen allergenic potential. I have observed that the same four classes of allergens found in fruit are expressed at different levels also in pollen, and their presence might support that the apple pollen can be considered allergenic as the fruit, deducing that apple allergy could also be indirectly caused by sensitization to pollen. Climate changes resulting from increases in temperature and air pollution influence pollen allergenicity, responsible for the dramatic raise in respiratory allergies (hay fever, bronchial asthma, conjunctivitis). Although the link between climate change and pollen allergenicity is proven, the underlying mechanism is little understood. Transglutaminases (TGases), a class of enzymes able to post-translationally modify proteins, are activated under stress and involved in some inflammatory responses, enhancing the activity of pro-inflammatory phospholipase A2, suggesting a role in allergies. Recently, a calcium-dependent TGase activity has been identified in the pollen cell wall, raising the possibility that pollen TGase may have a role in the modification of pollen allergens reported above, thus stabilizing them against proteases. This enzyme can be involved also in the transamidation of proteins present in the human mucosa interacting with surface pollen or, finally, the enzyme itself can represent an allergen, as suggested by studies on celiac desease. I have hypothesized that this pollen enzyme can be affected by climate changes and be involved in exhacerbating allergy response. The data presented in this thesis represent a scientific basis for future development of studies devoted to verify the hypothesis set out here. First, I have demonstrated the presence of an extracellular TGase on the surface of the grain observed either at the apical or the proximal parts of the pollen-tube by laser confocal microscopy (Iorio et al., 2008), that plays an essential role in apple pollen-tube growth, as suggested by the arrest of tube elongation by TGase inhibitors, such as EGTA or R281. Its involvement in pollen tube growth is mainly confirmed by the data of activity and gene expression, because TGase showed a peak between 15 min and 30 min of germination, when this process is well established, and an optimal pH around 6.5, which is close to that recorded for the germination medium. Moreover, data show that pollen TGase can be a glycoprotein as the glycosylation profile is linked both with the activation of the enzyme and with its localization at the pollen cell wall during germination, because from the data presented seems that the active form of TGase involved in pollen tube growth and pollen-stylar interaction is more exposed and more weakly bound to the cell wall. Interestingly, TGase interacts with fibronectin (FN), a putative SAMs or psECM component, inducing possibly intracellular signal transduction during the interaction between pollen-stylar occuring in the germination process, since a protein immunorecognised by anti-FN antibody is also present in pollen, in particular at the level of pollen grain cell wall in a punctuate pattern, but also along the shank of the pollen tube wall, in a similar pattern that recalls the signal obtained with the antibody anti TGase. FN represents a good substrate for the enzyme activity, better than DMC usually used as standard substrate for animal TGase. Thus, this pollen enzyme, necessary for its germination, is exposed on the pollen surface and consequently can easily interact with mucosal proteins, as it has been found germinated pollen in studies conducted on human mucus (Forlani, personal communication). I have obtained data that TGase activity increases in a very remarkable way when pollen is exposed to stressful conditions, such as climate changes and environmental pollution. I have used two different species of pollen, an aero allergenic (hazelnut, Corylus avellana) pollen, whose allergenicity is well documented, and an enthomophylus (apple, Malus domestica) pollen, which is not yet well characterized, to compare data on their mechanism of action in response to stressors. The two pollens have been exposed to climate changes (different temperatures, relative humidity (rH), acid rain at pH 5.6 and copper pollution (3.10 µg/l)) and showed an increase in pollen surface TGase activity that is not accompanied to an induced expression of TGase immunoreactive protein with AtPNG1p. Probably, climate change induce an alteration or damage to pollen cell wall that carries the pollen grains to release their content in the medium including TGase enzyme, that can be free to carry out its function as confirmed by the immunolocalisation and by the in situ TGase activity assay data; morphological examination indicated pollen damage, viability significantly reduced and in acid rain conditions an early germination of apple pollen, thus possibly enhancing the TGase exposure on pollen surface. Several pollen proteins were post-translationally modified, as well as mammalian sPLA2 especially with Corylus pollen, which results in its activation, potentially altering pollen allergenicity and inflammation. Pollen TGase activity mimicked the behaviour of gpl TGase and AtPNG1p in the stimulation of sPLA2, even if the regulatory mechanism seems different to gpl TGase, because pollen TGase favours an intermolecular cross-linking between various molecules of sPLA2, giving rise to high-molecular protein networks normally more stable. In general, pollens exhibited a significant endogenous phospholipase activity and it has been observed differences according to the allergenic (Corylus) or not-well characterized allergenic (Malus) attitude of the pollen. However, even if with a different intensity level in activation, pollen enzyme share the ability to activate the sPLA2, thus suggesting an important regulatory role for the activation of a key enzyme of the inflammatory response, among which my interest was addressed to pollen allergy. In conclusion, from all the data presented, mainly presence of allergens, presence of an extracellular TGase, increasing in its activity following exposure to environmental pollution and PLA2 activation, I can conclude that also Malus pollen can behave as potentially allergenic. The mechanisms described here that could affect the allergenicity of pollen, maybe could be the same occurring in fruit, paving the way for future studies in the identification of hyper- and hypo- allergenic cultivars, in preventing environmental stressor effects and, possibly, in the production of transgenic plants.