A Novel Technique for Quasi Resolution Enhancement in Digital Storage Oscilloscopes for CCD Video Signal Measurements

A novel and simple method for quasi-enhancement of measurement resolution in digital storage oscilloscopes (DSOs) using trigger delay function is presented. The method is useful for measurements on charge couple devices video signals and allows one to use DSO in a manner similar to a digitiser

Improved Passivant-induced Shunt Resistance Model for n-HgCdTe Photoconducting Infrared Detector

A multilayer model for the majority carrier distribution is employed to calculate the shunt resistance due to passivant-induced electric field in the accumulated n+ region. The carrier depth profile drops sharply away from the surface, finally attaining the bulk value. The effect of complete sidewall passivation on the shunt resistance is considered. The results show that if the contribution of sidewall passivation is neglected, the total detector resistance is overestimated by - 35 per cent. The detector responsivity calculations using the present model are compared with the Siliquini's model and the experimental data of Siliquini. It has been found that the present model yields relatively better agreement with the experimental data in shunt-dominated region

Design optimization of Pixel Structure for α-Si based uncooled Infrared detector

In this paper authors present the design and simulation results achieved for pixel structure of amorphous Si (α-Si) based bolometer array. Most uncooled IR detectors in the world are based on VOx material. But this is not a standard material in IC technology and has many inherent disadvantages. The α-Si, an alternative material with high TCR is becoming as popular. However, large TCR values, in this material are achieved only in films of high resistivity. To achieve TCR value more than 2.5%/K, α-Si film resistivity is ~ 80 ohms-cm. This gives rise to very large pixel resistance of the order of 100 Mega ohms depending upon the design of the leg structure. This high pixel resistance causes very large noise and hence lower sensitivity. If leg width or membrane thickness is increased in order to reduce the pixel resistance, then this results in higher thermal conductance which also decreases sensitivity. To overcome this problem, pixel structure is so designed that within a pixel, only part of the electrical conduction is through α-Si and rest is through metal. Simulation using Coventorware software has been done to optimize pixel resistance as well as thermal conductance through legs so that maximum sensitivity could be obtained. Optimization is also carried out in order to reduce sensitivity of pixel resistance to variation in material resistivity.Defence Science Journal, 2013, 63(6), pp.581-588, DOI:http://dx.doi.org/10.14429/dsj.63.575

Nutritional studies of Chara corallina

Physico-chemical analysis of the pond water supporting growth of Chara corallina and of those grown in different culture media in the laboratory conditions have been carried out. The physico-chemical parameters of the water of Napli forest and P.N. Mehra Botanical Garden show that Chara corallina requires less amount of nutrients and the level of pollution is quite low as is evident from the data and standards. The water is clear enough to allow penetration of visibility to its bottom. Napli forest and P.N. Mehra Botanical Garden lack rich diversity which may be attributed to some chemicals released by Chara corallina. In laboratory culture, it is found that Chara corallina can be grown in all three culture media, viz., Allen and Arnon’s medium , Chu-10 medium and BG-11 medium but growth is seen to be the best in Allen and Arnon’s culture medium in comparison with the other two culture media

Ability of enteroaggregative Escherichia coli strains to adhere in vitro to human intestinal mucosa

A collection of 44 enteroaggregative Escherichia coli (EAggEC) strains isolated from infants with diarrhea in India and the United Kingdom were examined for their ability to adhere in vitro to human intestinal mucosa and by electron microscopy for production of putative adherence factors. None of the strains adhered to human duodenal mucosa, and six strains tested did not adhere to ileal mucosa; all 44 strains, however, adhered to human colonic mucosa in localized aggregates. Electron microscopy of infected colonic mucosa indicated fimbrially mediated adhesion of the EAggEC strains. Four morphologically distinct kinds of fimbriae, including a new morphological type of E. coli fimbriae consisting of bundles of fine filaments, were identified among the EAggEC strains; this new type of fimbria was observed in 43 of the 44 EAggEC strains. Forty-three of the 44 EAggEC strains were positive with a DNA probe developed to identify EAggEC, and most of the strains belonged to serotypes unrelated to the other major classes of diarrheic E. coli. These results suggest that EAggEC may be a large-bowel pathogen and colonize the colon by a fimbrially mediated adhesion mechanism

Induction with Rabbit Antithymocyte Globulin following Orthotopic Liver Transplantation for Hepatitis C

Background: Hepatitis C (HCV) is the most common indication for liver transplantation in the US. Objective: Since steroids are the major stimulus of viral replication, we postulated that steroid-free immunosuppression might be a safer approach. Methods: From January 1995 to October 2002, we used steroid plus calcineurin inhibitor (CNI) immunosuppression after liver transplantation for HCV (steroid group, n=81). From October 2002 to June 2007, rabbit antithymocyte globulin (RATG) induction, followed by CNI and azathioprine (RATG group, n=73) was utilized. Results: There were no differences in 1- and 3-year patient/allograft survival rates. The incidence of acute rejection rate (19% vs. 28%), of biopsy-proven HCV recurrence (70% vs. 75%), and chronic rejection (6% vs. 9%) were comparable. The mean time to develop recurrent HCV was significantly longer in the RATG group (16.2 vs. 9.2 months, p=0.008). The incidence of severe portal fibrosis appears to be lower in RATG group compared to the steroid group; 14% vs. 4% (p=0.07). Conclusions: RATG induction is safe and effective after liver transplantation for HCV, but has no impact on the incidence of HCV recurrence and patient/allograft survival. However, a significant delay in time to HCV recurrence and a trend toward less rejection and portal fibrosis was observed

The Binding Site for TRAF2 and TRAF3 but Not for TRAF6 Is Essential for CD40-Mediated Immunoglobulin Class Switching

AbstractTo define the role of TRAF proteins in CD40-dependent isotype switching in B cells, we introduced wild-type (WT) and mutant CD40 transgenes that lacked the binding motifs for TRAF6 (CD40ΔTRAF6), TRAF2 and TRAF3 (CD40ΔTRAF2/3), or both (CD40ΔTRAFs) into B cells of CD40−/− mice. The in vivo isotype switch defect in CD40−/− mice was fully corrected by WT and CD40ΔTRAF6, partially by CD40ΔTRAF2/3, and not at all by CD40ΔTRAFs transgenes. CD40-mediated isotype switching, proliferation, and activation of p38, JNK, and NFκB in B cells were normal in WT and CD40ΔTRAF6 mice, severely impaired in CD40ΔTRAF2/3, and absent in CD40ΔTRAFs mice. These results suggest that binding to TRAF2 and/or TRAF3 but not TRAF6 is essential for CD40 isotype switching and activation in B cells

Population-based incidence of intussusception and a case-control study to examine the association of intussusception with natural rotavirus infection among Indian children

Background: A rotavirus vaccine previously licensed in the United States was withdrawn because it caused intussusception. Data on background intussusception rates in developing countries are required to plan pre- and postlicensure safety studies for new rotavirus vaccines. Also, it is unclear whether natural rotavirus infection is associated with intussusception. Methods: Passive surveillance for intussusception in a large, well-defined, poor, urban population in Delhi, India, was conducted in 2 phases. Intussusception was confirmed by ultrasonography or surgery. Fecal samples obtained from patients with intussusception at study hospitals (irrespective of their residence in study areas) and healthy control subjects were tested for rotavirus with use of enzyme immunoassay. If available, resected intestinal tissue samples were tested for rotavirus with use of immunohistochemistical analysis and reverse-transcription polymerase chain reaction. Results: The incidence of intussusception requiring hospitalization was 17.7 cases per 100,000 infant-years of follow-up (95% confidence interval, 5.9-41.4 cases per 100,000 infant-years). Detection rates of rotavirus in stool samples did not differ significantly between case patients and control subjects (4 of 42 case patients vs 6 of 92 control subjects), and no evidence of rotavirus was detected in any of the 22 patients with intussusception for whom intestinal tissue samples were available. Conclusions: The incidence of intussusception among Indian infants appears to be lower than that reported in other middle- and high-income countries. Natural rotavirus infection does not appear to be a major cause of intussusception in Indian infants