124 research outputs found
Fault Injection and Monitoring Capability for a Fault-Tolerant Distributed Computation System
The Configurable Fault-Injection and Monitoring System (CFIMS) is intended for the experimental characterization of effects caused by a variety of adverse conditions on a distributed computation system running flight control applications. A product of research collaboration between NASA Langley Research Center and Old Dominion University, the CFIMS is the main research tool for generating actual fault response data with which to develop and validate analytical performance models and design methodologies for the mitigation of fault effects in distributed flight control systems. Rather than a fixed design solution, the CFIMS is a flexible system that enables the systematic exploration of the problem space and can be adapted to meet the evolving needs of the research. The CFIMS has the capabilities of system-under-test (SUT) functional stimulus generation, fault injection and state monitoring, all of which are supported by a configuration capability for setting up the system as desired for a particular experiment. This report summarizes the work accomplished so far in the development of the CFIMS concept and documents the first design realization
Algorithm To Architecture Mapping Model (ATAMM) multicomputer operating system functional specification
A functional description of the ATAMM Multicomputer Operating System is presented. ATAMM (Algorithm to Architecture Mapping Model) is a marked graph model which describes the implementation of large grained, decomposed algorithms on data flow architectures. AMOS, the ATAMM Multicomputer Operating System, is an operating system which implements the ATAMM rules. A first generation version of AMOS which was developed for the Advanced Development Module (ADM) is described. A second generation version of AMOS being developed for the Generic VHSIC Spaceborne Computer (GVSC) is also presented
High-Intensity Radiated Field Fault-Injection Experiment for a Fault-Tolerant Distributed Communication System
Safety-critical distributed flight control systems require robustness in the presence of faults. In general, these systems consist of a number of input/output (I/O) and computation nodes interacting through a fault-tolerant data communication system. The communication system transfers sensor data and control commands and can handle most faults under typical operating conditions. However, the performance of the closed-loop system can be adversely affected as a result of operating in harsh environments. In particular, High-Intensity Radiated Field (HIRF) environments have the potential to cause random fault manifestations in individual avionic components and to generate simultaneous system-wide communication faults that overwhelm existing fault management mechanisms. This paper presents the design of an experiment conducted at the NASA Langley Research Center's HIRF Laboratory to statistically characterize the faults that a HIRF environment can trigger on a single node of a distributed flight control system
Stackable Form-Factor Peripheral Component Interconnect Device and Assembly
A stackable form-factor Peripheral Component Interconnect (PCI) device can be configured as a host controller or a master/target for use on a PCI assembly. PCI device may comprise a multiple-input switch coupled to a PCI bus, a multiplexor coupled to the switch, and a reconfigurable device coupled to one of the switch and multiplexor. The PCI device is configured to support functionality from power-up, and either control function or add-in card function
Comparing the Effects of Sulfasalazine and Shilajit on Liver Damage Caused by Acetic Acid-Induced Ulcerative Colitis in Male Rats
Background and Objective: Liver damage is one of the common complications after ulcerative colitis. The aim of this study is to compare liver protective effects of sulfasalazine and shilajit after ulcerative colitis.
Methods: In this experimental intervention study, 49 male Wistar rats weighing 200-250 grams were used in seven groups of 7: sham, ulcerative colitis, oral solution, oral Shilajit, sulfasalazine, rectal solution, and rectal Shilajit. To induce ulcerative colitis, after anesthetizing the animal, 2 cc of acetic acid (4%) was used by rectal administration. Four days after the development of colitis, Shilajit was administered for four days at a dose of 250 mg/kg by gavage and rectal methods. In each group, the levels of liver enzymes (SGPT, SGOT, ALP), direct bilirubin, total, and serum albumin were evaluated eight days after the induction of ulcerative colitis.
Findings: Sulfasalazine decreased total bilirubin (0.5967±0.04) and SGOT (113.3±12.7). Administering Shilajit rectally reduced direct bilirubin (0.10±0.02), albumin (3.17±0.2), SGOT (156.2±12.7) and administering Shilajit by gavage reduced SGOT (125.0±12.7), direct bilirubin (0.094±0.02), SGOT (125.0±12.7) and SGPT (93.8±7.5).
Conclusion: The results of the study showed that oral administration of Shilajit has more protective effects on liver damage caused by ulcerative colitis than rectal Shilajit, and this result is comparable to sulfasalazine
Seroprevalence of cytomegalovirus among women of reproductive age in iran: A systematic review and meta-analysis
Background: Human cytomegalovirus (CMV) able to cause infection for an entire lifetime. This systematic review and meta-analysis was conducted to determine seroprevalence of CMV among women of reproductive age in Iran. Methods: English and Persian databases such as Web of Science (WOS), PubMed, Scopus, Cochrane Library, SID, Iran doc, Iran Medex, Magiran, and Medlib were searched (from 2008 to 2017) accurately using the keywords: Cytomegalovirus, Pregnant women or Pregnancy, Epidemiology, Prevalence and Iran. Results: Results of 15 studies with total samples of 5253 persons from 2008 to 2017 were combined and meta-analyzed. The pooled prevalence rate of IgG among women was estimated 90 (95 CI: 87-93). The highest prevalence rate of IgG was in Tehran, Rasht, Mashhad and Yasoj, all 100 (95 CI: 100-100), and the lowest prevalence was in Jahrom 0.62 (95 CI: 53-71). The overall prevalence rate of IgM among women was estimated at 0.06 (95 CI: 0.03-0.13). The highest prevalence rate of IgM was in Kerman 0.34 (95 CI: 0.29-0.39) and Mashhad 0.25 (95 CI: 0.2-0.31), and the lowest prevalence was in Yasoj 0 (95 CI: 0.00-0.00) Conclusion: The prevalence of immunity in Iran, is satisfactory. Nevertheless, to maintain and increase the level of immunity across the country, it is necessary to routinely screen the women of reproductive ages across the country. © 2019, Iranian Journal of Public Health. All rights reserved
Risk factor investigation for cardiovascular health through WHO STEPS approach in Ardabil, Iran
Objectives: Reliable evidence is the keystone for any noncommunicable disease (NCD) prevention
plan to be initiated. In this study we carried out a risk factor investigation based on the WHO Stepwise approach to Surveillance (STEPS).
Methods: The study was conducted on 1000 adults between 15 and 64 years of age living in Ardabil province, north-west Iran during 2006, based on the WHO STEPS approach to surveillance of risk factors for NCD. At this stage only the first and second steps were carried out. Data
were collected through standard questionnaires and methods analyzed using STATA version 8 statistical software package.
Results: 29.0% of men and 2.6% of women were current daily tobacco smokers. The mean number of manufactured cigarettes smoked per day was 18.9 among current daily smokers.
Smoking was most prevalent among men of low-income families and those of lower education The mean body mass index (BMI) was 26.6 kg/m2, and was significantly correlated with systolic blood pressure. 58.9% were overweight or obese; 18.0% had raised blood pressure and 3.7%
had isolated systolic hypertension. The mean number of servings of fruit consumed per day was 1.1; 33.1% had low levels of activity. Combined risk factor analysis showed that 4.1%of participants were in the low-risk group (up to 5.1% among men and 3.2% among women).Those in the high-risk group comprised 25.6% in the 25- to 44-year age group and 49.7%in the 45- to 64-year age group. Mean BMI increased by age in both sexes at least at the firstthree decades of adult life.
Conclusion: Based on observed status of risk for cardiovascular health, burden of cardiovascular diseases is expected to increase if an effective prevention strategy is not undertaken
Desalination of aqueous solutions by LTA and MFI zeolite membranes using pervaporation method
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Social cognitive processes explain bias in juror decisions
Jury decisions are among the most consequential social decisions in which bias plays a notable role. While courts take measures to reduce the influence of non-evidentiary factors, jurors may still incorporate biases into their decisions. One common bias, crime-type bias, is the extent to which the perceived strength of a prosecutor’s case depends on the severity of the crime. Moral judgment, affect and social cognition have been proposed as core processes underlying this and other biases. Behavioral evidence alone has been insufficient to distinguish these explanations. To identify the mechanism underlying crime-type bias, we collected functional magnetic resonance imaging patterns of brain activation from mock jurors reading criminal scenarios. Brain patterns from crime-type bias were most similar to those associated with social cognition (mentalizing and racial bias) but not affect or moral judgment. Our results support a central role for social cognition in juror decisions and suggest that crime-type bias and cultural bias may arise from similar mechanisms.
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Documenting the Recovery of Vascular Services in European Centres Following the Initial COVID-19 Pandemic Peak: Results from a Multicentre Collaborative Study
Objective: To document the recovery of vascular services in Europe following the first COVID-19 pandemic peak. Methods: An online structured vascular service survey with repeated data entry between 23 March and 9 August 2020 was carried out. Unit level data were collected using repeated questionnaires addressing modifications to vascular services during the first peak (March – May 2020, “period 1”), and then again between May and June (“period 2”) and June and July 2020 (“period 3”). The duration of each period was similar. From 2 June, as reductions in cases began to be reported, centres were first asked if they were in a region still affected by rising cases, or if they had passed the peak of the first wave. These centres were asked additional questions about adaptations made to their standard pathways to permit elective surgery to resume. Results: The impact of the pandemic continued to be felt well after countries’ first peak was thought to have passed in 2020. Aneurysm screening had not returned to normal in 21.7% of centres. Carotid surgery was still offered on a case by case basis in 33.8% of centres, and only 52.9% of centres had returned to their normal aneurysm threshold for surgery. Half of centres (49.4%) believed their management of lower limb ischaemia continued to be negatively affected by the pandemic. Reduced operating theatre capacity continued in 45.5% of centres. Twenty per cent of responding centres documented a backlog of at least 20 aortic repairs. At least one negative swab and 14 days of isolation were the most common strategies used for permitting safe elective surgery to recommence. Conclusion: Centres reported a broad return of services approaching pre-pandemic “normal” by July 2020. Many introduced protocols to manage peri-operative COVID-19 risk. Backlogs in cases were reported for all major vascular surgeries
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