Satellite analog FDMA/FM to digital TDMA conversion

The results of a study which investigated design issues regarding the use of analog to digital (A/D) conversion on board a satellite are presented. The need for A/D, and of course D/A as well, conversion arose from a satellite design which required analog FDMA/FM up and down links to/from a digitally modulated intersatellite link. There are also some advantages when one must interconnect a large number of various spot beams which are using analog, and therefore cannot take advantage of SS/TDMA switching among the beams, thus resulting in low fill factors. Various tradeoffs were performed regarding the implementation of on-board A/D processing, including mass, power, and costs. The various technologies which were considered included flash ADCs, surface acoustic wave (SAW) devices, and digital signal processing (DSP) chips. Impact analyses were also performed to determine the effect on ground stations to convert to digital if the A/D approach were not implemented

Orogenital ulcers and the Behcet’s disease

Behcet’s’s disease is a systemic vasculitis involving small to large veins and arteries. It is a sporadic disease, mostly prevalent among the ancestors of the silk route. It is characterized by recurrent oral ulcers, genital ulcers, and uveitis. It also can manifest as skin, vascular, gastrointestinal, neurological, cardiac, and renal involvement. Though overall mortality is around 5%, delay in diagnosis and treatment may lead to significant morbidity. Cardiovascular and pulmonary arterial aneurysms are dreadful complications of this disease. Being uncommon in south India it is liable to be wrongly diagnosed and treated. Delay in the diagnosis and treatment may lead to severe complications. Here we present a case of Behcet’s disease which was managed at primary health care inadequately. We also demonstrated a quick response to steroids which are the mainstay of treatment. In this case presentation we illustrated pre and post treatment scrotal and oral Behcet’s’s lesions for clinicians to memorize. We also discussed international criteria to diagnose Behcet’s disease (ICBD) in concurrence with our case. In this presentation, we briefly described the involvement of other systems and their treatment. This article also elaborated on the latest developments in the treatment of Behcet’s disease

High Glucose-Mediated Oxidative Stress Impairs Cell Migration

Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we evaluate the hypothesis that high glucose concentrations inhibit cell migration. Using CHO.K1 cells, NIH-3T3 fibroblasts, mouse embryonic fibroblasts and primary skin fibroblasts from control and diabetic rats cultured in 5 mM D-glucose (low glucose, LG), 25 mM D-glucose (high glucose, HG) or 25 mM L-glucose medium (osmotic control - OC), we analyzed the migration speed, protrusion stability, cell polarity, adhesion maturation and the activity of the small Rho GTPase Rac1. We also analyzed the effects of reactive oxygen species by incubating cells with the antioxidant N-Acetyl-Cysteine (NAC). We observed that HG conditions inhibited cell migration when compared to LG or OC. This inhibition resulted from impaired cell polarity, protrusion destabilization and inhibition of adhesion maturation. Conversely, Rac1 activity, which promotes protrusion and blocks adhesion maturation, was increased in HG conditions, thus providing a mechanistic basis for the HG phenotype. Most of the HG effects were partially or completely rescued by treatment with NAC. These findings demonstrate that HG impairs cell migration due to an increase in oxidative stress that causes polarity loss, deficient adhesion and protrusion. These alterations arise, in large part, from increased Rac1 activity and may contribute to the poor wound healing observed in diabetic patients

Renoprotective effects of atorvastatin in diabetic mice: downregulation of RhoA and upregulation of Akt/GSK3

Potential benefits of statins in the treatment of chronic kidney disease beyond lipid-lowering effects have been described. However, molecular mechanisms involved in renoprotective actions of statins have not been fully elucidated. We questioned whether statins influence development of diabetic nephropathy through reactive oxygen species, RhoA and Akt/GSK3 pathway, known to be important in renal pathology. Diabetic mice (db/db) and their control counterparts (db/+) were treated with atorvastatin (10 mg/Kg/day, p.o., for 2 weeks). Diabetes-associated renal injury was characterized by albuminuria (albumin:creatinine ratio, db/+: 3.2 ± 0.6 vs. db/db: 12.5 ± 3.1*; *P<0.05), increased glomerular/mesangial surface area, and kidney hypertrophy. Renal injury was attenuated in atorvastatin-treated db/db mice. Increased ROS generation in the renal cortex of db/db mice was also inhibited by atorvastatin. ERK1/2 phosphorylation was increased in the renal cortex of db/db mice. Increased renal expression of Nox4 and proliferating cell nuclear antigen, observed in db/db mice, were abrogated by statin treatment. Atorvastatin also upregulated Akt/GSK3β phosphorylation in the renal cortex of db/db mice. Our findings suggest that atorvastatin attenuates diabetes-associated renal injury by reducing ROS generation, RhoA activity and normalizing Akt/GSK3β signaling pathways. The present study provides some new insights into molecular mechanisms whereby statins may protect against renal injury in diabetes

Projeto Interdisciplinar do Pantanal - Fase Umida (IPE-1)

A field campaign was carried out in the South Mato Grosso Pantanal, as part of a broad experimental program to study the characteristics of the weather and the climate of the central region of Brazil. The aim of this experiment is to investigate the structure of the surface boundary layer above the Pantanal, during the flood season, in a site representative of the region (19°33'48" S; 57°00'53"W), located about 1.5 km from the Pantanal Studies Base of the Federal University of Mato Grosso do Sul (UFMS), in Passo do Lontra, MS.Pages: