698 research outputs found

    Reliability and Quality Assurance Experience in Launcher Hold and Release System used in GSLV

    Get PDF
    The launcher hold and release system (LHRS) was successfully used, for the first time, for GSLV-DI mission after thorough test and evaluation, in line with reliability and quality assurance (R&QA) requirements. Various R&QA techniques are applied to make LHRS failure-free. Failure mode effect and criticality analysis (FMECA) was used as a tool for identifying critical failure modes. Single-point failure modes (SPFMs) identified from FMECA are strengthened by design modifications and the same are verified by testing. Testing philosophy is tailored to have more number of tests at the system level. Capability demonstration tests and failure mode simulation tests were carried out during system qualification phase. Acceptance tests are done on the flight hardware at launch pad to demonstrate better confidence on the system. This paper illustrates how R&QA techniques complimented and added value at different stages in the development cycle of LHRS, by means of few case studies. Testing methodologies adopted and problems encountered during the development and qualification phases are described in brief. Various problems surfaced during preparation for flight are also discussed

    NEUROIMMUNO MODULATION BY VESTIBULAR STIMULATION IN COLD WATER SWIMMING STRESS INDUCED WISTAR ALBINO RATS

    Get PDF
    ABSTRACTObjectives: We hypothesized that vestibular stimulation prevents stress-induced suppression of immunity by inhibiting the stress axes and to testthis hypothesis total leucocyte count, differential leucocyte count, platelet count, hemoglobin level, organ weight of spleen and liver were observedfollowing vestibular stimulation in cold water swimming stress induced Wistar albino rats.Methods: Totally, 24 healthy, adult male albino rats of Wistar strain were used in the present study. Rats were forced to swim in the plastic tubs(height: 60 cm, diameter: 40 cm) containing cold water, maintained at 10°C. The middle ear cavity was irrigated with hot (40°C) or cold (15°C) waterthrough a polyethylene tube for 15 days.Results: Data were analyzed by SPSS 20.0. Statistical tests used are two-way RM ANOVA and Bonferroni post-tests. Cold water vestibular stimulationwas significantly prevented effects of stress on hematological parameters (p<0.05). Both cold and hot water vestibular stimulation effectivelycontrolled stress induced changes on body weight and organ weights (p<0.05).Conclusion: Maximum effect of stress was observed on the 7th day in stress only group whereas this effect is minimized in cold water vestibularstimulation group and maintained in normal limits thereafter. We recommend further detailed study in this area is considered for further detailed study.Keywords: Caloric vestibular stimulation, Cold water swimming stress, Immunity.INTRODUCTIO

    Dosing pole recommendations for lymphatic filariasis elimination: A height-weight quantile regression modeling approach

    Get PDF
    BACKGROUND: The World Health Organization (WHO) currently recommends height or age-based dosing as alternatives to weight-based dosing for mass drug administration lymphatic filariasis (LF) elimination programs. The goals of our study were to compare these alternative dosing strategies to weight-based dosing and to develop and evaluate new height-based dosing pole scenarios. METHODOLOGY/PRINCIPAL FINDINGS: Age, height and weight data were collected from \u3e26,000 individuals in five countries during a cluster randomized LF clinical trial. Weight-based dosing for diethylcarbamazine (DEC; 6 mg/kg) and ivermectin (IVM; 200 ug/kg) with tablet numbers derived from a table of weight intervals was treated as the gold standard for this study. Following WHO recommended age-based dosing of DEC and height-based dosing of IVM would have resulted in 32% and 27% of individuals receiving treatment doses below those recommended by weight-based dosing for DEC and IVM, respectively. Underdosing would have been especially common in adult males, who tend to have the highest LF prevalence in many endemic areas. We used a 3-step modeling approach to develop and evaluate new dosing pole cutoffs. First, we analyzed the clinical trial data using quantile regression to predict weight from height. We then used weight predictions to develop new dosing pole cutoff values. Finally, we compared different dosing pole cutoffs and age and height-based WHO dosing recommendations to weight-based dosing. We considered hundreds of scenarios including country- and sex-specific dosing poles. A simple dosing pole with a 6-tablet maximum for both DEC and IVM reduced the underdosing rate by 30% and 21%, respectively, and was nearly as effective as more complex pole combinations for reducing underdosing. CONCLUSIONS/SIGNIFICANCE: Using a novel modeling approach, we developed a simple dosing pole that would markedly reduce underdosing for DEC and IVM in MDA programs compared to current WHO recommended height or age-based dosing

    Frequency and clinical significance of localized adverse events following mass drug administration for lymphatic filariasis in an endemic area in South India

    Get PDF
    Fear of adverse events (AEs) negatively affects compliance to mass drug administration (MDA) for lymphatic filariasis (LF) elimination program. Systemic AEs are believed to occur because of killing of microfilariae, whereas localized soft tissue reactions might be due to the death of adult worms following therapy. Most AEs are mild and self-limited. However, localized AEs are sometimes more significant and of concern to participants. Here, we describe localized AEs that were noted during a large community study that evaluated the safety of a triple-drug regimen (ivermectin, diethylcarbamazine, and albendazole) for the treatment of LF in India. We have also discussed the importance of timely detection and careful management of AEs for preserving community confidence in MDA

    Campus smoking policies and smoking-related Twitter posts originating from California public universities: Retrospective study

    Get PDF
    BACKGROUND: The number of colleges and universities with smoke- or tobacco-free campus policies has been increasing. The effects of campus smoking policies on overall sentiment, particularly among young adult populations, are more difficult to assess owing to the changing tobacco and e-cigarette product landscape and differential attitudes toward policy implementation and enforcement. OBJECTIVE: The goal of the study was to retrospectively assess the campus climate toward tobacco use by comparing tweets from California universities with and those without smoke- or tobacco-free campus policies. METHODS: Geolocated Twitter posts from 2015 were collected using the Twitter public application programming interface in combination with cloud computing services on Amazon Web Services. Posts were filtered for tobacco products and behavior-related keywords. A total of 42,877,339 posts were collected from 2015, with 2837 originating from a University of California or California State University system campus, and 758 of these manually verified as being about smoking. Chi-square tests were conducted to determine if there were significant differences in tweet user sentiments between campuses that were smoke- or tobacco-free (all University of California campuses and California State University, Fullerton) compared to those that were not. A separate content analysis of tweets included in chi-square tests was conducted to identify major themes by campus smoking policy status. RESULTS: The percentage of positive sentiment tweets toward tobacco use was higher on campuses without a smoke- or tobacco-free campus policy than on campuses with a smoke- or tobacco-free campus policy (76.7% vs 66.4%, P=.03). Higher positive sentiment on campuses without a smoke- or tobacco-free campus policy may have been driven by general comments about one’s own smoking behavior and comments about smoking as a general behavior. Positive sentiment tweets originating from campuses without a smoke- or tobacco-free policy had greater variation in tweet type, which may have also contributed to differences in sentiment among universities. CONCLUSIONS: Our study introduces preliminary data suggesting that campus smoke- and tobacco-free policies are associated with a reduction in positive sentiment toward smoking. However, continued expressions and intentions to smoke and reports of one’s own smoking among Twitter users suggest a need for more research to better understand the dynamics between implementation of smoke- and tobacco-free policies and resulting tobacco behavioral sentiment

    5,10,15,20-Tetra-2-furylporphyrin

    Get PDF
    Mol­ecules of the title macrocycle, C36H22N4O4, are located on an inversion center. The porphyrin ring shows a wave-like conformation with adjacent pyrrole rings tilted above the porphyrin plane and the inter­porphyrin distance is 3.584 (3) Å. The dihedral angles between the meso-furyl groups and the porphyrin plane are 38.87 (7) and 48.29 (7)°; these are much smaller than those observed for meso-tetra­phenyl­porphyrin, indicating that the meso-furyl groups are more inclined towards the porphyrin plane. The decrease in the dihedral angle is due to the presence of intra­molecular hydro­den bonding between the meso-fury O atom and the β-pyrrole CH group. Intra­molecular N—H⋯N hydrogen bonds are also present

    Importance of Spin-Orbit Interaction for the Electron Spin Relaxation in Organic Semiconductors

    Get PDF
    Despite the great interest organic spintronics has recently attracted, there is only a partial understanding of the fundamental physics behind electron spin relaxation in organic semiconductors. Mechanisms based on hyperfine interaction have been demonstrated, but the role of the spin-orbit interaction remains elusive. Here, we report muon spin spectroscopy and time-resolved photoluminescence measurements on two series of molecular semiconductors in which the strength of the spin-orbit interaction has been systematically modified with a targeted chemical substitution of different atoms at a particular molecular site. We find that the spin-orbit interaction is a significant source of electron spin relaxation in these materials
    corecore