6,656 research outputs found
Z_3 Dark Matter and Two-Loop Neutrino Mass
Dark matter is usually distinguished from ordinary matter by an odd-even
parity, i.e. the discrete symmetry Z_2. The new idea of Z_3 dark matter is
proposed with a special application to generating radiative Majorana neutrino
masses in two-loop order.Comment: expanded (9 pages, 2 figures), 2 references adde
A novel silicon membrane-based biosensing platform using distributive sensing strategy and artificial neural networks for feature analysis
A novel biosensing system based on a micromachined rectangular silicon membrane is proposed and investigated in this paper. A distributive sensing scheme is designed to monitor the dynamics of the sensing structure. An artificial neural network is used to process the measured data and to identify cell presence and density. Without specifying any particular bio-application, the investigation is mainly concentrated on the performance testing of this kind of biosensor as a general biosensing platform. The biosensing experiments on the microfabricated membranes involve seeding different cell densities onto the sensing surface of membrane, and measuring the corresponding dynamics information of each tested silicon membrane in the form of a series of frequency response functions (FRFs). All of those experiments are carried out in cell culture medium to simulate a practical working environment. The EA.hy 926 endothelial cell lines are chosen in this paper for the bio-experiments. The EA.hy 926 endothelial cell lines represent a particular class of biological particles that have irregular shapes, non-uniform density and uncertain growth behaviour, which are difficult to monitor using the traditional biosensors. The final predicted results reveal that the methodology of a neural-network based algorithm to perform the feature identification of cells from distributive sensory measurement has great potential in biosensing applications
Ribosomal S6K1 in POMC and AgRP Neurons Regulates Glucose Homeostasis but Not Feeding Behavior in Mice.
SummaryHypothalamic ribosomal S6K1 has been suggested as a point of convergence for hormonal and nutrient signals in the regulation of feeding behavior, bodyweight, and glucose metabolism. However, the long-term effects of manipulating hypothalamic S6K1 signaling on energy homeostasis and the cellular mechanisms underlying these roles are unclear. We therefore inactivated S6K1 in pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, key regulators of energy homeostasis, but in contrast to the current view, we found no evidence that S6K1 regulates food intake and bodyweight. In contrast, S6K1 signaling in POMC neurons regulated hepatic glucose production and peripheral lipid metabolism and modulated neuronal excitability. S6K1 signaling in AgRP neurons regulated skeletal muscle insulin sensitivity and was required for glucose sensing by these neurons. Our findings suggest that S6K1 signaling is not a general integrator of energy homeostasis in the mediobasal hypothalamus but has distinct roles in the regulation of glucose homeostasis by POMC and AgRP neurons
Canonical explicit B\"{a}cklund transformations with spectrality for constrained flows of soliton hierarchies
It is shown that explicit B\"{a}cklund transformations (BTs) for the
high-order constrained flows of soliton hierarchy can be constructed via their
Darboux transformations and Lax representation, and these BTs are canonical
transformations including B\"{a}cklund parameter and possess a
spectrality property with respect to and the 'conjugated' variable
for which the pair lies on the spectral curve. As model we
present the canonical explicit BTs with the spectrality for high-order
constrained flows of the Kaup-Newell hierarchy and the KdV hierarchy.Comment: 21 pages, Latex, to be published in "PHYSICA A
Intervention, recruitment and evaluation challenges in the Bangladeshi community: Experience from a peer lead educational course
<p>Abstract</p> <p>Background</p> <p>The incidence of Type 2 diabetes is increasing worldwide and diabetes is four times more common among ethnic minority groups than among the general Caucasian population. This study reflects on the specific issues of engaging people and evaluating interventions through written questionnaires within older ethnic minority groups.</p> <p>Methods</p> <p>The original protocol set out to evaluate an adapted version of the X-PERT<sup>® </sup>patient program <url>http://www.xpert-diabetes.org.uk/</url> using questionnaires and interviews.</p> <p>Results</p> <p>Questionnaires, even verbally completed, were unsuccessful and difficult to administer as participants found the questionnaire structure and design difficult to follow and did not perceive any benefit to completing the questionnaires. The benefits of attending the course were also poorly understood by participants and in many cases people participated in coming to the course as a favour to the researcher. Engaging participants required word of mouth and the involvement of active members of the community.</p> <p>Conclusion</p> <p>Peer led courses and their evaluation in older ethnic minority communities needs a very different approach for that in younger Caucasian patients. A structured approached to evaluation (favoured by western educational system) is inappropriate. Engaging participants is difficult and the employment of local well known people is essential.</p
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Characterization of inter-seasonal climatic variability through dry-season rice productivity in the north-west region of Bangladesh
Inter-annual climatic variability in Bangladesh is significant and the probability of occurrence of extreme episodic/ climatic events has increased in the last couple of decades and thus threatening food security. Impact of inter-seasonal climatic va riability on Boro rice (dry season) yield in north-western parts of Bangladesh was analyzed using the historic weather datasets for 1971 to 2010 and MAKESENS model. Boro rice yield increased from 1980 onwards and the growth rate picked up with time. Inter-annual and inter-seasonal climatic variability was noticed through maximum and minimum temperatures, rainfall and sunshine hours. In general, temperatures and rainfall showed increasing trends but sunshine hours were decreasing gradually during the study period. Growth rates in average annual maximum, minimum and mean air temperatures were 0.001, 0.016 and 0.009°C year-1, respectively. On regional scale, Boro-rice seasonal maximum temperature was decreasing by 0.013°C year-1 but minimum and mean temperatures were increasing by 0.024 and 0.006°C year-1, respectively. Annual average sunshine hours in the study location were in decreasing trend by 0.027 hr year-1, but reduction in seasonal sunshine hours was 0.035 hr year-1. Inter-seasonal climatic variability was characterized through the Boro-rice yields in four test regions of north-west region of Bangladesh. Trend line equations were evolved for assessing the impact of climatic variations on Bororice yield. If maximum temperature changes by 1oC, Boro rice yield could be increased by 0.13 t ha-1, but it would reduce by 0.34 t ha-1 with one degree rise in minimum temperature. If sunshine hour decreases by 1 hr, Boro rice yield would decrease by 0.70 t ha-1 in study locations. Combined effects of maximum and minimum temperatures and sunshine hours showed significant influence on grain yields of Boro rice. These imply that temperature tolerant and solar radiation use-efficient rice varieties need to be bred for combating climate change impact in Bangladesh. There is a need to identify optimum sowing/transplanting window for the region, choice of suitable cultivars/ideo-types, and adoption of appropriate water and nutrients management strategies and adoption of appropriate resource conservation technologies for sustainable Boro rice production in Bangladesh
Prediction of anti-Alzheimer’s activity of flavonoids targeting acetylcholinesterase in silico
Introduction – Prenylated and pyrano-flavonoids of the genus Artocarpus J. R. Forster & G. Forster are well known for their acetylcholinesterase (AchE) inhibitory, anticholinergic, antiinflammatory, antimicrobial, antioxidant, antiproliferative and tyrosinase inhibitory activities. Some of these compounds have also been shown to be effective against Alzheimer’s disease. Objective – The aim of the in silico study was to establish protocols to predict the most effective flavonoid from prenylated and pyrano-flavonoid classes for AchE inhibition linking to the potential treatment of Alzheimer’s disease. Methodology – Three flavonoids isolated from Artocarpus anisophyllus Miq. were selected for the study. With these compounds, Lipinski filter, ADME/Tox screening, molecular docking and QSAR were performed in silico. In vitro activity was evaluated by bioactivity staining based on the Ellman’s method. Results – In the Lipinski filter and ADME/Tox screening, all test compounds produced positive results, but in the target fishing, only one flavonoid could successfully target AchE. Molecular docking was performed on this flavonoid, and this compound gained the score as -13.5762. From the QSAR analysis the IC50 was found to be 1659.59 nM. Again, 100 derivatives were generated from the parent compound and docking was performed. The derivative number 20 was the best scorer i.e., -31.6392 and IC50 was predicted as 6.025 nM. Conclusion – Results indicated that flavonoids could be efficient inhibitors of AchE and thus, could be useful in the management of Alzheimer’s disease
Debajyoti Choudhury
Gluon fusion into a very heavy neutrino pair by Higgs exchange is shown to
lead to substantial production cross sections at supercolliders even
without any extra generation of quarks. Rates are calculated for scalar as well
as pseudoscalar Higgs. The angular correlation between dileptons emerging from
the decays of the neutrinos shows distinctive features for Dirac and Majorana
neutrinos as well as for scalar and pseudoscalar Higgs
CP violation at colliders
The prospects of experimental detection of violation at and
colliders are reviewed. After a general discussion on the
quantities which can measure violation and on the implications of the
theorem, various possibilities of measuring violation arising
outside the standard model are taken up. violation in leptonic processes,
especially polarization effects in are discussed
next. violation in and production and decay is
also described. (Based on talk presented at the WHEPP3, Madras, January 1994).Comment: 20 pages, latex, no figures (only revision is the comment that the
article is based on a talk presented at WHEPP3, Madras, January 1994
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