342 research outputs found
Exploring resistive memory technologies for re-configurable logic application
Reconfigurable logic application is a computer architecture combining some of the flexibility of software with the high performance of hardware by processing with very flexible high speed computing fabrics like field-programmable gate arrays (FPGAs). The hardware configuration is stored in embedded memory bit cells. In such configuration bit cells, the “read” performance has more importance than the “write” performance. Different types of memories can be used for the application. ReRAM (Resistive Switching Random Access Memory), one of the nonvolatile memory technologies, also known as RRAM, stores information in a passive two-terminal electronic device. Other popular resistive memory technologies being used and researched are STTRAM, PCM, eFuse, Anti-Fuse etc. STTRAM (spin transfer torque random access memory) is very attractive since it demonstrates all the qualities of a universal memory. STT-RAM uses existing CMOS technology with 2 additional masks and less than 3% cost adder. e-Fuse is a recent promising memory technology invented by IBM which allows for the dynamic but one-time real-time reprogramming of computer chips. On the other hand Anti-Fuse, is claimed to be providing superior protection for Hardware devices then other technologies. The main objective of this research is to explore the resistive memory technologies primarily ReRAM, PCM STTRAM, e-Fuse and Anti-Fuse, and investigate which resistive memory technique is a better candidate for the reconfigurable logic application
Circulating Mucosal Associated Invariant T Cells Are Activated in Vibrio cholerae O1 Infection and Associated with Lipopolysaccharide Antibody Responses
Background: Mucosal Associated Invariant T (MAIT) cells are innate-like T cells found in abundance in the intestinal mucosa, and are thought to play a role in bridging the innate-adaptive interface. Methods: We measured MAIT cell frequencies and antibody responses in blood from patients presenting with culture-confirmed severe cholera to a hospital in Dhaka, Bangladesh at days 2, 7, 30, and 90 of illness. Results: We found that MAIT (CD3+CD4−CD161hiVα7.2+) cells were maximally activated at day 7 after onset of cholera. In adult patients, MAIT frequencies did not change over time, whereas in child patients, MAITs were significantly decreased at day 7, and this decrease persisted to day 90. Fold changes in MAIT frequency correlated with increases in LPS IgA and IgG, but not LPS IgM nor antibody responses to cholera toxin B subunit. Conclusions: In the acute phase of cholera, MAIT cells are activated, depleted from the periphery, and as part of the innate response against V. cholerae infection, are possibly involved in mechanisms underlying class switching of antibody responses to T cell-independent antigens
Antigen-Specific Memory B-cell Responses to Enterotoxigenic Escherichia coli Infection in Bangladeshi Adults
Background: Multiple infections with diverse enterotoxigenic E. coli (ETEC) strains lead to broad spectrum protection against ETEC diarrhea. However, the precise mechanism of protection against ETEC infection is still unknown. Therefore, memory B cell responses and affinity maturation of antibodies to the specific ETEC antigens might be important to understand the mechanism of protection. Methodology In this study, we investigated the heat labile toxin B subunit (LTB) and colonization factor antigens (CFA/I and CS6) specific IgA and IgG memory B cell responses in Bangladeshi adults (n = 52) who were infected with ETEC. We also investigated the avidity of IgA and IgG antibodies that developed after infection to these antigens. Principal Findings Patients infected with ETEC expressing LT or LT+heat stable toxin (ST) and CFA/I group or CS6 colonization factors developed LTB, CFA/I or CS6 specific memory B cell responses at day 30 after infection. Similarly, these patients developed high avidity IgA and IgG antibodies to LTB, CFA/I or CS6 at day 7 that remained significantly elevated at day 30 when compared to the avidity of these specific antibodies at the acute stage of infection (day 2). The memory B cell responses, antibody avidity and other immune responses to CFA/I not only developed in patients infected with ETEC expressing CFA/I but also in those infected with ETEC expressing CFA/I cross-reacting epitopes. We also detected a significant positive correlation of LTB, CFA/I and CS6 specific memory B cell responses with the corresponding increase in antibody avidity. Conclusion: This study demonstrates that natural infection with ETEC induces memory B cells and high avidity antibodies to LTB and colonization factor CFA/I and CS6 antigens that could mediate anamnestic responses on re-exposure to ETEC and may help in understanding the requirements to design an effective vaccination strategies
Vibrio cholerae Serogroup O139: Isolation from Cholera Patients and Asymptomatic Household Family Members in Bangladesh between 2013 and 2014.
BACKGROUND: Cholera is endemic in Bangladesh, with outbreaks reported annually. Currently, the majority of epidemic cholera reported globally is El Tor biotype Vibrio cholerae isolates of the serogroup O1. However, in Bangladesh, outbreaks attributed to V. cholerae serogroup O139 isolates, which fall within the same phylogenetic lineage as the O1 serogroup isolates, were seen between 1992 and 1993 and in 2002 to 2005. Since then, V. cholerae serogroup O139 has only been sporadically isolated in Bangladesh and is now rarely isolated elsewhere. METHODS: Here, we present case histories of four cholera patients infected with V. cholerae serogroup O139 in 2013 and 2014 in Bangladesh. We comprehensively typed these isolates using conventional approaches, as well as by whole genome sequencing. Phenotypic typing and PCR confirmed all four isolates belonging to the O139 serogroup. FINDINGS: Whole genome sequencing revealed that three of the isolates were phylogenetically closely related to previously sequenced El Tor biotype, pandemic 7, toxigenic V. cholerae O139 isolates originating from Bangladesh and elsewhere. The fourth isolate was a non-toxigenic V. cholerae that, by conventional approaches, typed as O139 serogroup but was genetically divergent from previously sequenced pandemic 7 V. cholerae lineages belonging to the O139 or O1 serogroups. CONCLUSION: These results suggest that previously observed lineages of V. cholerae O139 persist in Bangladesh and can cause clinical disease and that a novel disease-causing non-toxigenic O139 isolate also occurs.This study was supported by a Grant OPP50419 from the Bill & Melinda Gates Foundation and National Institutes of Health (U01A1077883, R01AI106878 and U01AI058935). Additionally, the study was supported by the core grants of icddr,b. icddr,b is thankful to the Governments of Australia, Bangladesh, Canada, Sweden and the UK for providing core/unrestricted support. AEM and NRT were supported by Wellcome Trust grant 098051. AEM is supported by Biotechnology and Biological Sciences Research Council grant BB/M014088/1. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/10.1371/journal.pntd.000418
Cost of illness for cholera in a high risk urban area in Bangladesh: an analysis from household perspective
BACKGROUND: Cholera poses a substantial health burden to developing countries such as Bangladesh. In this study, the objective is to estimate the economic burden of cholera treatments incurred by households. The study was carried out in the context of a large vaccine trial in an urban area of Bangladesh. METHODS: The study used a combination of prospective and retrospective incidence-based cost analyses of cholera illness per episode per household. A total of 394 confirmed cholera hospitalized cases were identified and treated in the study area during June–October 2011. Households with cholera patients were interviewed within 15 days after discharge from hospitals or clinics. To estimate the total cost of cholera illness a structured questionnaire was used, which included questions on direct medical costs, non-medical costs, and the indirect costs of patients and caregivers. RESULTS: The average total household cost of treatment for an episode of cholera was US7.40) and 75.4% (US21.50) was higher than that of children aged 5–14 years (US30.40) per household. Among medical components, medicines are the largest cost driver. No clear socioeconomic gradient emerged from our study, but limited demographic patterns were observed in the cost of illness. By preventing cholera cases, large production losses can be reduced
Micronutrients and Anaemia
Micronutrient deficiencies and anaemia remain as major health concerns for children in Bangladesh. Among the micronutrient interventions, supplementation with vitamin A to children aged less than five years has been the most successful, especially after distribution of vitamin A was combined with National Immunization Days. Although salt sold in Bangladesh is intended to contain iodine, much of the salt does not contain iodine, and iodine deficiency continues to be common. Anaemia similarly is common among all population groups and has shown no sign of improvement even when iron-supplementation programmes have been attempted. It appears that many other causes contribute to anaemia in addition to iron deficiency. Zinc deficiency is a key micronutrient deficiency and is covered in a separate paper because of its importance among new child-health interventions
Supplementation of Fish-oil and Soy-oil During Pregnancy and Psychomotor Development of Infants
Supplementation of docosahexaenoic acid (DHA) in infancy improves
neuro-developmental outcomes, but there is limited information about
the impact of supplementing pregnant mothers with DHA on the
development of their infants. In a follow-up of a randomized,
double-blind controlled trial with 400 pregnant mothers, the effects of
supplementation of fish-oil or soy-oil (4 g/day) during the last
trimester of pregnancy on psychomotor development and behaviour of
infants at 10 months of age (n=249) were assessed. The quality of
psychosocial stimulation at home (HOME) and nutritional status of the
subjects were also measured. There were no significant differences in
the fish-oil group and soy-oil group in any of the developmental
(mean\ub1SD mental development index: 102.5\ub18.0 vs
101.5\ub17.8, psychomotor development index: 101.7\ub110.0 vs
100.5\ub110.1) or behavioural outcomes. It may, therefore, be
concluded that supplementation of fish-oil during the last trimester of
pregnancy does not have any added benefit over supplementation of
soy-oil on the development or behaviour of infants in this population
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