80 research outputs found
Class(es) of Factor-Type Estimator(s) in Presence of Measurement Error
When data is collected via sample survey it is assumed whatever is reported by a respondent is correct. However, given the issues of prestige bias, personal respect and honor, respondents’ self-reported data often produces over- or under- estimated values as opposed to true values regarding the variables under question. This causes measurement error to be present in sample values. This article considers the factortype estimator as an estimation tool and examines its performance under a measurement error model. Expressions of optimization are derived and theoretical results are supported by numerical examples
Comparison of membrane proteins of Mycobacterium tuberculosis H37Rv and H37Ra strains
Background: The potential causes for variation in virulence between distinct M. tuberculosis strains are still not fully known. However, differences in protein expression are probably an important factor. In this study we used a labelfree quantitative proteomic approach to estimate differences in protein abundance between two closely related M. tuberculosis strains; the virulent H37Rv strain and its attenuated counterpart H37Ra. Results: We were able to identify more than 1700 proteins from both strains. As expected, the majority of the identified proteins had similar relative abundance in the two strains. However, 29 membrane-associated proteins were observed with a 5 or more fold difference in their relative abundance in one strain compared to the other. Of note, 19 membrane- and lipo-proteins had higher abundance in H37Rv, while another 10 proteins had a higher abundance in H37Ra. Interestingly, the possible protein-export membrane protein SecF (Rv2586c), and three ABCtransporter proteins (Rv0933, Rv1273c and Rv1819c) were among the more abundant proteins in M. tuberculosis H37Rv. Conclusion: Our data suggests that the bacterial secretion system and the transmembrane transport system may be important determinants of the ability of distinct M. tuberculosis strains to cause disease
Synthesis and characterization of 5-aryl-1,3,4-oxadiazole-2(3h)thione derivatives
1,3,4-oxadiazoles represent a class of heterocyclic five membered compounds it contain two nitrogen and one oxygen of great importance in Pharmaceutical chemistry. This nucleus show four isomeric forms 1,2,4-oxadiazole,1,3,4-oxadiazole, 1,2,5-oxadiazole, and 1,2,3-oxadiazole. This nucleus has various biological activity such as antioxidant, antimicrobial, antifungal, antitumor, antidepressant, anticancer, analgesic etc. have been reported. A series of 1,3,4-oxadiazoles-2(3H)thione derivative has been synthesized in four steps and the derivative were characterized by FTIR spectral analysis. This article explain the different biological activities associated with 1,3,4-oxadiazole five membered ring are useful for researchers across the world working on this nucleus
Development, standardization of polyherbal formulation of analgesic ointment of plant Carum copticum, Mentha piperita, Cedrus deodara
Ayurveda is one of the world’s oldest systems of medicine. It originated in India and has evolved there over thousands of years. The term “Ayurveda” combines then Sanskrit words ayur (life) andVeda (science or knowledge). Ayurveda means “the science of life. Medicinal plants and herbal drugs have played a key role in world health. According to world health organization (WHO), about 80% of the world population currently utilizes the herbal drugs. People are using herbal medicines from centuries for safety, efficacy, cultural acceptability, non-toxic, lesser side effects and easily available at affordable prices. In recent times, there has been a move in universal trend from synthetic to herbal medicine due to side effects of synthetic products. Herbal products may contain a single herb or combinations of several different herbs believed to have complementary and /synergistic effects. Some herbal products, including many traditional medicine formulations, also include animal products and minerals. Herbal products are sold as either raw plants or extracts of portions of the plant or in the form formulation i.e. tablet, capsule, syrup, cream and ointment etc. The different parts of plants with analgesic were taken up for the present study and investigated for the phytochemical screening and used for the formulation of analgesic ointment. Present study deals with formulation, Standardization, evaluation of ointment made from alcoholic extract and essential oil of different plants
Counting mycobacteria in infected human cells and mouse tissue: a comparison between qPCR and CFU
Due to the slow growth rate and pathogenicity of mycobacteria, enumeration by traditional reference methods like colony counting is notoriously time-consuming, inconvenient and biohazardous. Thus, novel methods that rapidly and reliably quantify mycobacteria are warranted in experimental models to facilitate basic research, development of vaccines and anti-mycobacterial drugs. In this study we have developed quantitative polymerase chain reaction (qPCR) assays for simultaneous quantification of mycobacterial and host DNA in infected human macrophage cultures and in mouse tissues. The qPCR method cannot discriminate live from dead bacteria and found a 10- to 100-fold excess of mycobacterial genomes, relative to colony formation. However, good linear correlations were observed between viable colony counts and qPCR results from infected macrophage cultures (Pearson correlation coefficient [r] for M. tuberculosis = 0.82; M. a. avium = 0.95; M. a. paratuberculosis = 0.91). Regression models that predict colony counts from qPCR data in infected macrophages were validated empirically and showed a high degree of agreement with observed counts. Similar correlation results were also obtained in liver and spleen homogenates of M. a. avium infected mice, although the correlations were distinct for the early phase (© 2012 Pathak et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Definition of novel cell envelope associated proteins in Triton X-114 extracts of Mycobacterium tuberculosis H37Rv
<p>Abstract</p> <p>Background</p> <p>Membrane- and membrane-associated proteins are important for the pathogenicity of bacteria. We have analysed the content of these proteins in virulent <it>Mycobacterium tuberculosis </it>H37Rv using Triton X-114 detergent-phase separation for extraction of lipophilic proteins, followed by their identification with high resolution mass spectrometry.</p> <p>Results</p> <p>In total, 1417 different proteins were identified. <it>In silico </it>analysis of the identified proteins revealed that 248 proteins had at least one predicted trans-membrane region. Also, 64 of the identified proteins were predicted lipoproteins, and 54 proteins were predicted as outer membrane proteins. Three-hundred-and-ninety-five of the observed proteins, including 91 integral membrane proteins were described for the first time. Comparison of abundance levels of the identified proteins was performed using the exponentially modified protein abundance index (emPAI) which takes into account the number of the observable peptides to the number of experimentally observed peptide ions for a given protein. The outcome showed that among the membrane-and membrane-associated proteins several proteins are present with high relative abundance. Further, a close examination of the lipoprotein LpqG (Rv3623) which is only detected in the membrane fractions of <it>M. tuberculosis </it>but not in <it>M. bovis</it>, revealed that the homologous gene in <it>M. bovis </it>lack the signal peptide and lipobox motif, suggesting impaired export to the membrane.</p> <p>Conclusions</p> <p>Altogether, we have identified a substantial proportion of membrane- and membrane-associated proteins of <it>M. tuberculosis </it>H37Rv, compared the relative abundance of the identified proteins and also revealed subtle differences between the different members of the <it>M. tuberculosis </it>complex.</p
Counting Mycobacteria in Infected Human Cells and Mouse Tissue: A Comparison between qPCR and CFU
Due to the slow growth rate and pathogenicity of mycobacteria, enumeration by traditional reference methods like colony counting is notoriously time-consuming, inconvenient and biohazardous. Thus, novel methods that rapidly and reliably quantify mycobacteria are warranted in experimental models to facilitate basic research, development of vaccines and anti-mycobacterial drugs. In this study we have developed quantitative polymerase chain reaction (qPCR) assays for simultaneous quantification of mycobacterial and host DNA in infected human macrophage cultures and in mouse tissues. The qPCR method cannot discriminate live from dead bacteria and found a 10- to 100-fold excess of mycobacterial genomes, relative to colony formation. However, good linear correlations were observed between viable colony counts and qPCR results from infected macrophage cultures (Pearson correlation coefficient [r] for M. tuberculosis = 0.82; M. a. avium = 0.95; M. a. paratuberculosis = 0.91). Regression models that predict colony counts from qPCR data in infected macrophages were validated empirically and showed a high degree of agreement with observed counts. Similar correlation results were also obtained in liver and spleen homogenates of M. a. avium infected mice, although the correlations were distinct for the early phase (<day 9 post-infection) and later phase (≥day 20 post-infection) liver r = 0.94 and r = 0.91; spleen r = 0.91 and r = 0.87, respectively. Interestingly, in the mouse model the number of live bacteria as determined by colony counts constituted a much higher proportion of the total genomic qPCR count in the early phase (geometric mean ratio of 0.37 and 0.34 in spleen and liver, respectively), as compared to later phase of infection (geometric mean ratio of 0.01 in both spleen and liver). Overall, qPCR methods offer advantages in biosafety, time-saving, assay range and reproducibility compared to colony counting. Additionally, the duplex format allows enumeration of bacteria per host cell, an advantage in experiments where variable cell death can give misleading colony counts
RecurrentGemma: Moving Past Transformers for Efficient Open Language Models
We introduce RecurrentGemma, a family of open language models which uses Google\u27s novel Griffin architecture. Griffin combines linear recurrences with local attention to achieve excellent performance on language. It has a fixed-sized state, which reduces memory use and enables efficient inference on long sequences. We provide two sizes of models, containing 2B and 9B parameters, and provide pre-trained and instruction tuned variants for both. Our models achieve comparable performance to similarly-sized Gemma baselines despite being trained on fewer tokens
Systems analysis of the process of implementing an innovation.
Massachusetts Institute of Technology, Alfred P. Sloan School of Management. Thesis. 1968. M.S.MICROFICHE COPY ALSO AVAILABLE IN DEWEY LIBRARY.Bibliography: leaves 116-117.M.S
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