33,789 research outputs found
Antimicrobial Activity of Actinomycetes Against Multidrug Resistant Staphylococcus aureus, E. coli and Various Other Pathogens
Purpose: The rapid emergence of drug resistance among pathogenic bacteria, especially multidrugresistant bacteria, underlines the need to look for new antibiotics.Methods: In the present study, 134 different actinomycetes, isolated from the soil samples collected from different localities of Punjab and Himachal Pradesh, were screened for antimicrobial activity against various test organisms including multidrug-resistant methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli in order to identify potential antibiotic producers.Results: Among these isolates, 51 (38 %) showed antimicrobial activity against one or more test organisms and six exhibited promising broad-spectrum activity against all the tested organisms. The observed cultural, morphological, physiological and biochemical characteristics confirmed that these isolates are species of the genus, Streptomyces.Conclusion: Further studies on the bioactive metabolites from these cultures will be useful for discovering novel compounds of clinical and agricultural use.Keywords: Actinomycetes, Broad spectrum antibiotics, Multidrug-resistant Staphylococcus aureus, Streptomyces
Next-to-leading order QCD predictions for W+W+jj production at the LHC
Because the LHC is a proton-proton collider, sizable production of two
positively charged W-bosons in association with two jets is possible. This
process leads to a distinct signature of same sign high-pt leptons, missing
energy and jets. We compute the NLO QCD corrections to the QCD-mediated part of
pp -> W+W+jj. These corrections reduce the dependence of the production
cross-section on the renormalization and factorization scale to about +- 10
percent. We find that a large number of W+W+jj events contain a relatively hard
third jet. The presence of this jet should help to either pick up the W+W+jj
signal or to reject it as an unwanted background.Comment: 15 pages, 5 (lovely) figures, v3 accepted for publication in JHEP,
corrects tables in appendi
Conducting rigorous research with subgroups of at-risk youth: lessons learned from a teen pregnancy prevention project in Alaska
In 2010, Alaska Department of Health and Social Services (DHSS) received federal funding to test an
evidence-based teen pregnancy prevention program. The grant required a major modification to an existing
program and a randomized control trial (RCT) to test its effectiveness. As the major modifications, Alaska
used peer educators instead of adults to deliver the program to youth aged 1419 instead of the original
curriculum intended age range of 1214. Cultural and approach adaptations were included as well. After
4 years of implementation and data collection, the sample was too small to provide statistically significant
results. The lack of findings gave no information about the modification, nor any explanation of how the
curriculum was received, or reasons for the small sample. This paper reports on a case study follow-up to
the RCT to better understand outcome and implementation results. For this study, researchers reviewed
project documents and interviewed peer educators, state and local staff, and evaluators. Three themes
emerged from the data: (a) the professional growth of peer educators and development of peer education, (b)
difficulties resulting from curriculum content, especially for subpopulations of sexually active youth, youth
identified as lesbian, gay, bisexual, transgender, queer, intersex and/or asexual, pregnant, and parenting
youth and (c) the appropriateness of an RCT with subpopulations of at-risk youth. Three recommendations
emerged from the case study. First, including as many stakeholders as possible in the program and
evaluation design phases is essential, and must be supported by appropriate funding streams and training.
Second, there must be recognition of the multiple small subpopulations found in Alaska when adapting
programs designed for a larger and more homogeneous population. Third, RCTs may not be appropriate
for all population subgroups.Ye
On the role of different Skyrme forces and surface corrections in exotic cluster-decay
We present cluster decay studies of Ni formed in heavy-ion
collisions using different Skyrme forces. Our study reveals that different
Skyrme forces do not alter the transfer structure of fractional yields
significantly. The cluster decay half-lives of different clusters lies within
\pm 10% for PCM and \pm 15% for UFM.Comment: 13 pages,6 figures and 1 table; in press Pramana Journal of Physics
(2010
The barocaloric effect: A Spin-off of the Discovery of High-Temperature Superconductivity
Some key results obtained in joint research projects with Alex M\"uller are
summarized, concentrating on the invention of the barocaloric effect and its
application for cooling as well as on important findings in the field of
high-temperature superconductivity resulting from neutron scattering
experiments.Comment: 26 pages, 9 figure
Stochastic make-to-stock inventory deployment problem: an endosymbiotic psychoclonal algorithm based approach
Integrated steel manufacturers (ISMs) have no specific product, they just produce finished product from the ore. This enhances the uncertainty prevailing in the ISM regarding the nature of the finished product and significant demand by customers. At present low cost mini-mills are giving firm competition to ISMs in terms of cost, and this has compelled the ISM industry to target customers who want exotic products and faster reliable deliveries. To meet this objective, ISMs are exploring the option of satisfying part of their demand by converting strategically placed products, this helps in increasing the variability of product produced by the ISM in a short lead time. In this paper the authors have proposed a new hybrid evolutionary algorithm named endosymbiotic-psychoclonal (ESPC) to decide what and how much to stock as a semi-product in inventory. In the proposed theory, the ability of previously proposed psychoclonal algorithms to exploit the search space has been increased by making antibodies and antigen more co-operative interacting species. The efficacy of the proposed algorithm has been tested on randomly generated datasets and the results compared with other evolutionary algorithms such as genetic algorithms (GA) and simulated annealing (SA). The comparison of ESPC with GA and SA proves the superiority of the proposed algorithm both in terms of quality of the solution obtained and convergence time required to reach the optimal/near optimal value of the solution
Gluon fusion contribution to W+W- + jet production
We describe the computation of the process that contributes
to the production of two -bosons and a jet at the CERN Large Hadron Collider
(LHC). While formally of next-to-next-to-leading order (NNLO) in QCD, this
process can be evaluated separately from the bulk of NNLO QCD corrections
because it is finite and gauge-invariant. It is also enhanced by the large
gluon flux and by selection cuts employed in the Higgs boson searches in the
decay channel , as was first pointed out by Binoth {\it et al.}
in the context of production. For cuts employed by the ATLAS
collaboration, we find that the gluon fusion contribution to
enhances the background by about ten percent and can lead to moderate
distortions of kinematic distributions which are instrumental for the ongoing
Higgs boson searches at the LHC. We also release a public code to compute the
NLO QCD corrections to this process, in the form of an add-on to the package
{\tt MCFM}.Comment: 13 pages, 4 figures, 3 table
Perceptually guided Computer-Generated Holography
Computer-Generated Holography (CGH) promises to deliver genuine, high-quality visuals at any depth. We argue that combining CGH and perceptually guided graphics can soon lead to practical holographic display systems that deliver perceptually realistic images. We propose a new CGH method called metameric varifocal holograms. Our CGH method generates images only at a user’s focus plane while displayed images are statistically correct and indistinguishable from actual targets across peripheral vision (metamers). Thus, a user observing our holograms is set to perceive a high quality visual at their gaze location. At the same time, the integrity of the image follows a statistically correct trend in the remaining peripheral parts. We demonstrate our differentiable CGH optimization pipeline on modern GPUs, and we support our findings with a display prototype. Our method will pave the way towards realistic visuals free from classical CGH problems, such as speckle noise or poor visual quality
On the Numerical Evaluation of Loop Integrals With Mellin-Barnes Representations
An improved method is presented for the numerical evaluation of multi-loop
integrals in dimensional regularization. The technique is based on
Mellin-Barnes representations, which have been used earlier to develop
algorithms for the extraction of ultraviolet and infrared divergencies. The
coefficients of these singularities and the non-singular part can be integrated
numerically. However, the numerical integration often does not converge for
diagrams with massive propagators and physical branch cuts. In this work,
several steps are proposed which substantially improve the behavior of the
numerical integrals. The efficacy of the method is demonstrated by calculating
several two-loop examples, some of which have not been known before.Comment: 13 pp. LaTe
A Meta-Analysis of Genome-Wide Association Scans Identifies IL18RAP, PTPN2, TAGAP, and PUS10 As Shared Risk Loci for Crohn's Disease and Celiac Disease
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
- …