1,096 research outputs found
Electric and Magnetic fields due to Dirac particles in FRW spacetime
Some solutions of the Maxwell equations with Dirac particles for the source
in FRW spacetime are discussed. The Green's function of the equation for the
radial component of the Maxwell fields, F_{r\eta} and F_{\theta\phi} is solved.
Green's function is found to reduce to that of Minkowskian spacetime in the
appropriate limit. Also, the Lienard-Wiechert type solution is derived. Also,
the solutions with the Dirac particle current is also presented. It is found
that the F_{r\eta} is composed of even angular momentum states while the odd
states constitue F_{\theta\phi} .Comment: 8 pages including 2 figure
Consequences of Koshi flood 2008 in terms of sedimentation characteristics and agricultural practices
Diversity of butterflies with respect to altitudinal rise at various pockets of the Langtang National Park, central Nepal
The Langtang National Park which covers an area of 1760 sq.km was studied extensively for the occurrence and status of butterflies within the altitudinal ranges of 1500 m at Syaprubensi to 4300 m around Langtang glacier area. Addition to altitudes, the decline in floral diversity with temperature reduction in higher elevation basically controlled the species richness of butterflies specifically above 3000 m elevations. Habitat preference for diverse species of these colorful and agile insects is poorly represented above that elevation. This study conducted at different periods in 2010 and 2011 covering both the spring and summer seasons came up with a list of different status categories of 126 species. A rich diversity was noted at 1500 m (Syaprubensi) to 2900 m at Deurali on the way to the glacier (4300 m). Parnassius hardwickei and Parnassius epaphus epaphus which were seen with good population in previous studies at Dhimsa (3200 m) are at declining stage as a consequence of habitat loss and human interferences
Dataset from: Lapses in perceptual decisions reflect exploration.
Perceptual decision-makers often display a constant rate of errors independent of evidence strength. These âlapsesâ are treated as a nuisance arising from noise tangential to the decision, e.g. inattention or motor errors. Here, we use a multisensory decision task in rats to demonstrate that these explanations cannot account for lapsesâ stimulus dependence. We propose a novel explanation: lapses reflect a strategic trade-off between exploiting known rewarding actions and exploring uncertain ones. We tested the modelâs predictions by selectively manipulating one actionâs reward magnitude or probability. As uniquely predicted by this model, changes were restricted to lapses associated with that action. Finally, we show that lapses are a powerful tool for assigning decision-related computations to neural structures based on disruption experiments (here, posterior striatum and secondary motor cortex). These results suggest that lapses reflect an integral component of decision-making and are informative about action values in normal and disrupted brain states
Indonesia's contested domains: deforestation, rehabilitation and conservation-with-development in Central Kalimantan's tropical peatlands
Tropical peat swamp forests (TPSF) in Indonesia have long faced competition between industrial demand for timber, the subsistence require- ments of local communities and, more recently, global concern about the need to conserve tropical peat carbon stores, ecosystem services and biodiversity. This paper uses concepts of ecological distribution and environmental justice to investigate how tensions between conservation and livelihood goals have played out on the ground and examine who has gained and lost out from recent TPSF exploitation, conservation and rehabilitation initiatives. A central focus is how peat-based communities in Central Kalimantan have adapted their livelihoods to changing peatland conditions and management policies with particular emphasis on the livelihood impacts of conservation-with-development initiatives in the area. It is argued that despite recent emphasis on âwin-winâ initiatives, the costs of environmental conservation are rarely distributed in proportion to their benefit
Morphological characterization of intraspecific variation for trichome traits in tomato (Solanum lycopersicum)
Trichomes, the hairlike protuberances in plants, have been well known to act as the first line of defense against herbivores, and abiotic stresses, along with other structural defenses such as spines, thorns, and waxes. We previously reported the tremendous variation in trichome traits among different wild and cultivated Solanum species and demonstrated that trichomes types and density are traditionally miscalculated and often misnamed. However, intraspecific variation in trichome traits is poorly understood, although this has implications for stress tolerance and resistance breeding programs in economically important crop species and can also mediate ecological interactions at multiple trophic levels in their wild congeners. In this study, using tomato as a model, we characterized the trichomes from 10 commonly grown varieties using a minimal sample prep desktop scanning electron microscopy, and followed up with estimating their dimensions across the varieties and trichome types. We hypothesized that although trichome number may vary, the varieties will have similar trichome types, based on current literature. Our results show that there is significant variation for trichome number as well as dimensions of trichome types among these varieties. Furthermore, when we separately analyzed the number and dimensions of commonly found glandular and non-glandular trichomes, the results were consistent with broad assessment of trichomes, showing consistent variation among varieties, suggesting that trichome studies should not be limited to basic classification into glandular and non-glandular, and should accommodate the sub-types and their dimensions
Extrapulmonary Tuberculosis: A retrospective Study at a tertiary care hospital in Palpa, Nepal
Background: Extra-pulmonary tuberculosis (EPTB) is a significant global health problem. Related studies to it in different places and diff erent durations are indicated by many previous research findings. Findings of this study could be beneficial for its preventive and control strategies. Methodology: Retrospective analysis of clinical specimens submitted to Central laboratory of Lumbini Medical College and Teaching Hospital (LMCTH) for extrapulmonary tuberculosis was performed. Total 261 samples submitted from April 2011 to February 2013 were included for analysis in this study. Results: Total 20.7% (54/261) prevalence of EPTB was reported. Based on sites involved; lymph node 87.03%, pleural effusion7.40%, peritoneal5.55% were found. Genderwise equal prevalence was seen among male and females. Age-wise prevalence among patients between 21-40 years was reported. Conclusion: Our finding indicates great necessity for further large scale study on prevalence of EPTB in this location for its prevention and control
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