42 research outputs found
q-Deformed Kink Solutions
The q-deformed kink of the model is obtained via the
normalisable ground state eigenfunction of a fluctuation operator associated
with the q-deformed hyperbolic functions. From such a bosonic zero-mode the
q-deformed potential in 1+1 dimensions is found, and we show that the
q-deformed kink solution is a kink displaced away from the origin.Comment: REvtex, 11 pages, 2 figures. Preprint CBPF-NF-005/03, site at
http://www.cbpf.br. Revised version to appear in International Journal of
Modern Physics
Accelerating Cold Dark Matter Cosmology ()
A new kind of accelerating flat model with no dark energy that is fully
dominated by cold dark matter (CDM) is investigated. The number of CDM
particles is not conserved and the present accelerating stage is a consequence
of the negative pressure describing the irreversible process of gravitational
particle creation. A related work involving accelerating CDM cosmology has been
discussed before the SNe observations [Lima, Abramo & Germano, Phys. Rev. D53,
4287 (1996)]. However, in order to have a transition from a decelerating to an
accelerating regime at low redshifts, the matter creation rate proposed here
includes a constant term of the order of the Hubble parameter. In this case,
does not need to be small in order to solve the age problem and the
transition happens even if the matter creation is negligible during the
radiation and part of the matter dominated phase. Therefore, instead of the
vacuum dominance at redshifts of the order of a few, the present accelerating
stage in this sort of Einstein-de Sitter CDM cosmology is a consequence of the
gravitational particle creation process. As an extra bonus, in the present
scenario does not exist the coincidence problem that plagues models with
dominance of dark energy. The model is able to harmonize a CDM picture with the
present age of the universe, the latest measurements of the Hubble parameter
and the Supernovae observations.Comment: 9 pages, 6 figures, typos corrected, references added, discussion in
Appendix B extende
Bovine colostrum supplementation improves bone metabolism in an osteoporosis-induced animal model
Osteoporosis is characterized by bone loss. The present study aims to investigate the effects of bovine colostrum (BC) on bone metabolism using ovariectomized (OVX) and orchidectomized (ORX) rat models. Twenty-seven-week-old Wistar Han rats were randomly assigned as: (1) placebo control, (2) BC supplementation dose 1 (BC1: 0.5 g/day/OVX, 1 g/day/ORX), (3) BC supplementation dose 2 (BC2: 1 g/day/OVX, 1.5 g/day/ORX) and (4) BC supplementation dose 3 (BC3: 1.5 g/day/OVX, 2 g/day/ORX). Bone microarchitecture, strength, gene expression of VEGFA, FGF2, RANKL, RANK and OPG, and bone resorption/formation markers were assessed after four months of BC supplementation. Compared to the placebo, OVX rats in the BC1 group exhibited significantly higher cortical bone mineral content and trabecular bone mineral content (p < 0.01), while OVX rats in the BC3 group showed significantly higher trabecular bone mineral content (p < 0.05). ORX rats receiving BC dose 2 demonstrated significantly higher levels of trabecular bone mineral content (p < 0.05). Serum osteocalcin in the ORX was pointedly higher in all BC supplementation groups than the placebo (BC1: p < 0.05; BC2, BC3: p < 0.001). Higher doses of BC induced significantly higher relative mRNA expression of OPG, VEGFA, FGF2 and RANKL (p < 0.05). BC supplementation improves bone metabolism of OVX and ORX rats, which might be associated with the activation of the VEGFA, FGF2 and RANKL/RANK/OPG pathways.EC -European Commission(778277
Glia-Pinealocyte Network: The Paracrine Modulation of Melatonin Synthesis by Tumor Necrosis Factor (TNF)
The pineal gland, a circumventricular organ, plays an integrative role in defense responses. The injury-induced suppression of the pineal gland hormone, melatonin, which is triggered by darkness, allows the mounting of innate immune responses. We have previously shown that cultured pineal glands, which express toll-like receptor 4 (TLR4) and tumor necrosis factor receptor 1 (TNFR1), produce TNF when challenged with lipopolysaccharide (LPS). Here our aim was to evaluate which cells present in the pineal gland, astrocytes, microglia or pinealocytes produced TNF, in order to understand the interaction between pineal activity, melatonin production and immune function. Cultured pineal glands or pinealocytes were stimulated with LPS. TNF content was measured using an enzyme-linked immunosorbent assay. TLR4 and TNFR1 expression were analyzed by confocal microscopy. Microglial morphology was analyzed by immunohistochemistry. In the present study, we show that although the main cell types of the pineal gland (pinealocytes, astrocytes and microglia) express TLR4, the production of TNF induced by LPS is mediated by microglia. This effect is due to activation of the nuclear factor kappa B (NF-kB) pathway. In addition, we observed that LPS activates microglia and modulates the expression of TNFR1 in pinealocytes. As TNF has been shown to amplify and prolong inflammatory responses, its production by pineal microglia suggests a glia-pinealocyte network that regulates melatonin output. The current study demonstrates the molecular and cellular basis for understanding how melatonin synthesis is regulated during an innate immune response, thus our results reinforce the role of the pineal gland as sensor of immune status
Identification of Antifungal Compounds Active against Candida albicans Using an Improved High-Throughput Caenorhabditis elegans Assay
Candida albicans, the most common human pathogenic fungus, can establish a persistent lethal infection in the intestine of the microscopic nematode Caenorhabditis elegans. The C. elegans–C. albicans infection model was previously adapted to screen for antifungal compounds. Modifications to this screen have been made to facilitate a high-throughput assay including co-inoculation of nematodes with C. albicans and instrumentation allowing precise dispensing of worms into assay wells, eliminating two labor-intensive steps. This high-throughput method was utilized to screen a library of 3,228 compounds represented by 1,948 bioactive compounds and 1,280 small molecules derived via diversity-oriented synthesis. Nineteen compounds were identified that conferred an increase in C. elegans survival, including most known antifungal compounds within the chemical library. In addition to seven clinically used antifungal compounds, twelve compounds were identified which are not primarily used as antifungal agents, including three immunosuppressive drugs. This assay also allowed the assessment of the relative minimal inhibitory concentration, the effective concentration in vivo, and the toxicity of the compound in a single assay
Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF
M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe
Materials produced from plant biomass: part II: evaluation of crystallinity and degradation kinetics of cellulose
In this study Eucalyptus grandis (CEG) and Pinus taeda (CPT) cellulose fibers obtained from kraft and sulfite pulping process, respectively, were characterized using Fourier transform infrared (FTIR) spectroscopy and thermogravimetry (TGA). The degradation kinetic parameters were determined by TGA using Coats and Redfern method. FTIR results showed that CPT presented a more ordered structure with higher crystallinity than CEG. Thermogravimetric results showed that CPT had a higher thermal stability than CEG. The kinetic results revel that for CEG the degradation mechanism occurs mainly by random nucleation, although phase boundary controlled reactions also occurs while for CPT the degradation process is more related with phase boundary controlled reactions. Results demonstrated that differences between thermal stability and degradation mechanisms might be associated with differences in the cellulose crystalline structure probably caused by different pulping processes used for obtaining the cellulose fibers
Evaluation of Methods for the Analysis of Untreated and Processed Lignocellulosic Biomasses
The overall efficiency of the transformation of lignocellulosic materials to usable
products as chemicals and fuels must be governed by adequate analysis of products
before and after treatments. Using some promising technologies, lignocelluloses which
are biomasses from marine plant and trees, grains, food and non-food crops, and woodbased
can give products as fuel alcohol and other chemicals. Various methods of
transformation from feedstock to valuable end products are discussed in the scientific
literature. Therefore, yields must justify methods used for biomass transformations. As
a result, adequate compositional analysis of these processing stages is needed. In this
chapter, standard common methods such as gravimetric, chromatography,
spectroscopic and their variations for analysis on both untreated and treated
lignocelluloses are highlighted. The ease of the use and challenges with
recommendations to their applicability to quantifying lignocelluloses fractionations for
reproducibility and to be representative are discussed. With biomass technology,
virtually all and even more products that can be produced from fossil energy can also
be produced from biomass energy. Adequate analysis is therefore necessary
Young people's political engagement in the hip-hop movement
What leads young people to engage in political activism, creating or participating in interest groups? This question is discussed in the light of results obtained from a research on a group of rappers involved with the hip-hop movement in the city of Campinas, São Paulo. Their dispositions toward activism are analyzed as a result of the objective and subjective conditions under which they were socialized, apprehended through a study of their family's social trajectory. In turn, their concrete engagement in political activities is seen as the never-permanent result of meetings and interactions developed inside networks of different kinds, including the affective ones, located in a social space that is made concrete through institutions and collective ways of acting and thinking that guide everyday micro-decisions, including those relative to political action.O que leva alguns jovens a se envolver com a militância política, criando ou participando de grupos de interesse? Essa questão é discutida a partir dos resultados de uma pesquisa sobre um grupo de rappers envolvido com o movimento hiphop na cidade de Campinas, estado de São Paulo. Suas disposições para a militância são analisadas como resultado das condições objetivas e subjetivas em que se deu sua socialização, apreendidas por meio do estudo da trajetória social de suas famílias. Por sua vez, a entrada concreta em militância é analisada como resultado, nunca definitivo, dos encontros e das interações desenvolvidas no interior de redes de relações de vários tipos, inclusive afetivas, que se localizam num espaço social concretizado em instituições, modos de agir e de pensar que orientam microdecisões cotidianas, incluindo aquelas associadas à ação política.¿Qué es lo que lleva a algunos jóvenes a envolverse con la militancia política, creando o participando de grupos de interés? Esta cuestión es discutida a partir de los resultados de un estudio sobre un grupo de rappers involucrado con el movimiento hip-hop en la ciudad de Campinas, estado de São Paulo. Sus disposiciones para la militancia son analizadas como resultado de las condiciones objetivas y subjetivas en que se dio su socialización, aprendidas a través del estudio de la trayectoria social de sus familias. Sin embargo, la entrada concreta en la militancia es analizada como resultado, nunca definitivo, de los encuentros y de las interacciones desarrolladas en el interior de redes de relaciones de varios tipos, inclusive afectivas, que se localizan en un espacio social concretizado en instituciones, modos de actuar y de pensar que orientan microdecisiones cotidianas, incluyendo aquellas asociadas a la acción política.13014