1,070 research outputs found
Interference of Mycobacterium tuberculosis with macrophage responses
Tuberculosis, caused by Mycobacterium tuberculosis, has become an important health and economic burden, with more than four thousand people succumbing to the disease every day. Thus, there is an urgent need to understand the molecular basis of this pathogen's success in causing disease in humans, in order to develop new drugs superior to conventional drugs available at present. One reason why M. tuberculosis is such a dangerous microbe lies within its ability to survive within infected hosts, thereby efficiently circumventing host immune responses. Over the past few years, a number of mechanisms have been unravelled that are utilized by M. tuberculosis to survive within hosts and to avoid immune defence mechanisms. Several of these mechanisms have been described in this communication that may be useful for the development of novel compounds to treat tuberculosis
Neural Network based p-q-r Theory for Harmonic Reduction and Neutral Current Mitigation
The power quality compensator chosen in this paper is a DSTATCOM which integrates a three phase four leg Voltage Source Converter (VSC) with a DC capacitor. The major role of the DSTATCOM is to mitigate the components of harmonic/reactive current present in the line current thereby shapes the grid current to be sinusoidal and improves the power factor nearly unity under varying conditions. In addition DSATATCOM mitigates neutral current (Isn) and balances the load currents under unbalanced conditions in three phase four wire (3P4W) distribution system. The control strategy proposed for the DSTATCOM is a Neural Network (NN) based p-q-r theory with two Artificial Neural Network (ANN) controllers for a 3P4W distribution system. The reference signal for 3P3W Shunt Active Power Filter (SAPF) is calculated by implementing an ANN controller. The alleviation of Isn under unbalanced condition is achieved by another ANN controller which produces reference signal for the 1Φ APF. The performance of the proposed DSTATCOM is analysed for various conditions through simulations in MATLAB SIMULINK and the simulation results justify the effectiveness of the propounded NN based control algorithm for DSTATCOM
Exploring prospects of novel drugs for tuberculosis
Tuberculosis remains a disease with an enormous impact on public health worldwide. With the continuously increasing epidemic of drug-resistant tuberculosis, new drugs are desperately needed. However, even for the treatment of drug-sensitive tuberculosis, new drugs are required to shorten the treatment duration and thereby prevent development of drug resistance. Within the past ten years, major advances in tuberculosis drug research have been made, leading to a considerable number of antimycobacterial compounds which are now in the pipeline. Here we discuss a number of these novel promising tuberculosis drugs, as well as the discovery of two new potential drug targets for the development of novel effective drugs to curb the tuberculosis pandemic, ie, the coronin 1 and protein kinase G pathways. Protein kinase G is secreted by mycobacteria and is responsible for blocking lysosomal delivery within the macrophage. Coronin 1 is responsible for activating the phosphatase, calcineurin, and thereby preventing phagosome-lysosome fusion within the macrophage. Blocking these two pathways may lead to rapid killing of mycobacteri
Improved power quality buck boost converter for SMPS
In this paper, a Neural Network (NN) controlled Buck-Boost Converter (BBC) based Switched Mode Power Supply (SMPS) for a PC application is proposed. The proposed BBC is analyzed, modeled and designed for the rated load. Generally, the utilization of Multiple Output SMPS (MOSMPS) for PC application introduces Power Quality (PQ) issues in the power system network. Unlike conventional SMPS the proposed NN controlled BBC can accomplish improvement of power quality. The NN controller reduces the Total Harmonic Distortion (THD) of source current below 5%, maintains input side Power Factor (PF) to be nearly unity and improves the output voltage regulation. In the proposed system, NN controller replaces the conventional PI controller and overcomes the drawbacks of the conventional system. The proposed BBC is validated adopting MATLAB/SIMULINK software. The simulation analysis validate that the proposed NN controlled BBC performs better than conventional converter in terms of PQ indices under fluctuating conditions
Sampling intervals
THE STATUS OF SAMPLING INTERVALS BETWEEN OIL ANALYSIS HAS BEEN REVIEWED AND
A FRAMEWORK FOR AN ALTERNATIVE APPROACH TO THE DETERMINATION OF SAMPLING
INTERVALS IS DISCUSSED.supported with funds provided by Kelly Air Force
Base, (SA-ALC/MME1), Texas, 79241http://archive.org/details/samplinginterval00jay
Introduction of pre and post lecture multiple choice question for second year undergraduate medical students in microbiology: a technique to assess knowledge acquired from the lecture
Background: Didactic lectures are the most commonly used method of teaching in many medical institutes. There are certain disadvantages in this method. It is essential to evaluate whether the learning objectives have been accomplished. In the present study pre and post lecture MCQs (Multiple choice questions) are introduced for second year medical students in microbiology lectures and to assess the effect on gaining and retention of knowledge acquired at the end of the lecture.Methods: The fourth semester medical students were divided into two groups of 35 each (study and control group). Both the groups were administered the pre and post lecture MCQs for two topics in parasitology. For the Study group the Pre test MCQs were prepared in such a way incorporating the learning objectives of the lecture. The pretest questions for the control group were prepared from an unrelated topic. Both the groups were administered the common post test questions. The mean, standard deviation and correlation coefficient (by spearman correlation coefficient) and p values were analysed.Results: The post test mean scores of both the groups were compared by unpaired t test and the p value was found to be statistically significant (less than 0.0001). The study group had a considerably higher mean score compared with the control group for both the lecture classes. There was a positive correlation between the pre and post lecture MCQS.Conclusions: Testing by introducing Pre and post lecture MCQ in lecture has an impact on retention of knowledge
Central polar cap convection response to short duration southward Interplanetary Magnetic Field
International audienceCentral polar cap convection changes associated with southward turnings of the Interplanetary Magnetic Field (IMF) are studied using a chain of Canadian Advanced Digital Ionosondes (CADI) in the northern polar cap. A study of 32 short duration (~1 h) southward IMF transition events found a three stage response: (1) initial response to a southward transition is near simultaneous for the entire polar cap; (2) the peak of the convection speed (attributed to the maximum merging electric field) propagates poleward from the ionospheric footprint of the merging region; and (3) if the change in IMF is rapid enough, then a step in convection appears to start at the cusp and then propagates antisunward over the polar cap with the velocity of the maximum convection. On the nightside, a substorm onset is observed at about the time when the step increase in convection (associated with the rapid transition of IMF) arrives at the polar cap boundary
Does Information and Communication Technology Improve Job Satisfaction? The Moderating Role of Sales Technology Orientation
Empirical research concerning the role of information and communication technology (ICT) in shaping business-to-business salesforce job satisfaction remains relatively scarce. The authors propose and empirically test a causal model that theoretically represents structural relationships among factors comprising ICT and eventual salesperson job satisfaction. Study results indicate that ICT indirectly influences job satisfaction through salesforce administrative performance. While ICT infrastructure, training, and support positively relate to administrative performance, none of them influence outcome performance significantly. In addition, salesperson technology orientation moderates the effect of both ICT infrastructure and support on job satisfaction. Managerial insights and implications from the research are discussed
Some statistical procedures for the joint oil analysis program
http://archive.org/details/somestatisticalp00bar
The Influence of Statistical versus Exemplar Appeals on Indian Adults’ Health Intentions: An Investigation of Direct Effects and Intervening Persuasion Processes
In two separate investigations, we examined the persuasive effectiveness of statistical versus exemplar appeals on Indian adults’ smoking cessation and mammography screening intentions. To more comprehensively address persuasion processes, we explored whether message response and perceived message effectiveness functioned as antecedents to persuasive effects. Results showed that statistical appeals led to higher levels of health intentions than exemplar appeals. In addition, findings from both studies indicated that statistical appeals stimulated more attention and were perceived as more effective than anecdotal accounts. Among male smokers, statistical appeals also generated greater cognitive processing than exemplar appeals. Subsequent mediation analyses revealed that message response and perceived message effectiveness fully carried the influence of appeal format on health intentions. Given these findings, future public health initiatives conducted among similar populations should design messages that include substantive factual information while ensuring that this content is perceived as credible and valuable. [ABSTRACT FROM PUBLISHER
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