1,740 research outputs found
Preliminary Studies on the Epidemiology of the Potato Aphids in West Bengal (Homoptera: Aphididae).
M. persicae and A. gossypii are the two species of aphids which infest potato crop in West Bengal. Both the species are highly polyphagous and have a wide range of host plants. They infest the potato crop at the early stage of development and persist almost throughout the growing season of the crop. Potato fields nearabout Calcutta are therefore, subjected to the attack of the aphids throughout the growing season. Both the species are abundant before the sowing of potato, in areas near Calcutta. Early sowing of potato in these areas, therefore, is not likely to be effective in avoiding their infestations. The production of the alatae and the peak period of infestation seem to be largely dependant on the condition of the foliage. The aphids are not uniformly distributed on the potato foliage. They are particularly abundant on the middle and lower leaves and as such, insecticidal sprayings should adequately cover the entire foliage for satisfactory control of the aphids.M. persicae and A. gossypii are the two species of aphids which infest potato crop in West Bengal. Both the species are highly polyphagous and have a wide range of host plants. They infest the potato crop at the early stage of development and persist almost throughout the growing season of the crop. Potato fields nearabout Calcutta are therefore, subjected to the attack of the aphids throughout the growing season. Both the species are abundant before the sowing of potato, in areas near Calcutta. Early sowing of potato in these areas, therefore, is not likely to be effective in avoiding their infestations. The production of the alatae and the peak period of infestation seem to be largely dependant on the condition of the foliage. The aphids are not uniformly distributed on the potato foliage. They are particularly abundant on the middle and lower leaves and as such, insecticidal sprayings should adequately cover the entire foliage for satisfactory control of the aphids
Effect of Edge Roughness on Electronic Transport in Graphene Nanoribbon Channel Metal Oxide Semiconductor Field-Effect Transistors
Results of quantum mechanical simulations of the influence of edge disorder
on transport in graphene nanoribbon metal oxide semiconductor field-effect
transistors (MOSFETs) are reported. The addition of edge disorder significantly
reduces ON-state currents and increases OFF-state currents, and introduces wide
variability across devices. These effects decrease as ribbon widths increase
and as edges become smoother. However the bandgap decreases with increasing
width, thereby increasing the band-to-band tunneling mediated subthreshold
leakage current even with perfect nanoribbons. These results suggest that
without atomically precise edge control during fabrication, MOSFET performance
gains through use of graphene will be difficult to achieve.Comment: 8 pages, 5 figure
Characterization of fragment emission in ^{20}Ne (7 - 10 MeV/nucleon) + ^{12}C reactions
The inclusive energy distributions of the complex fragments (3 Z
7) emitted from the bombardment of ^{12}C by ^{20}Ne beams with incident
energies between 145 and 200 MeV have been measured in the angular range
10 50^{o}. Damped fragment yields in all the cases
have been found to be the characteristic of emission from fully energy
equilibrated composites. The binary fragment yields are compared with the
standard statistical model predictions. Enhanced yields of entrance channel
fragments (5 Z 7) indicate the survival of orbiting-like process
in ^{20}Ne + ^{12}C system at these energies.Comment: 18 pages, 13 figure
Survival of orbiting in Ne (7 - 10 MeV/nucleon) + C reactions
The inclusive energy distributions of fragments with Z 3 emitted from
the bombardment of C by Ne beams with incident energies between
145 and 200 MeV have been measured in the angular range
10 - 50. Damped fragment yields in all cases have been found to
be characteristic of emission from fully energy equilibrated composites; for B,
C fragments, average Q-values, , were independent of the centre of mass
emission angle (), and the angular distributions followed
1/sin like variation, signifying long life times of the
emitting di-nuclear systems. Total yields of these fragments have been found to
be much larger compared to the standard statistical model predictions of the
same. This may be indicative of the survival of orbiting like process in
C + Ne system at these energies.Comment: 7 pages, 5 figures, accepted for publication in Phys. Rev. C (Rapid
Communication
Calibration of a solid state nuclear track detector (SSNTD) with high detection threshold to search for rare events in cosmic rays
We have investigated a commercially available polymer for its suitability as
a solid state nuclear track detector (SSNTD). We identified that polymer to be
polyethylene terephthalate (PET) and found that it has a higher detection
threshold compared to many other widely used SSNTDs which makes this detector
particularly suitable for rare event search in cosmic rays as it eliminates the
dominant low Z background. Systematic studies were carried out to determine its
charge response which is essential before any new material can be used as an
SSNTD. In this paper we describe the charge response of PET to 129Xe, 78Kr and
49Ti ions from the REX-ISOLDE facility at CERN, present the calibration curve
for PET and characterize it as a nuclear track detector
Co-expression Profiling of Autism Genes in the Mouse Brain
Autism spectrum disorder (ASD) is one of the most prevalent and highly heritable neurodevelopmental disorders in humans. There is significant evidence that the onset and severity of ASD is governed in part by complex genetic mechanisms affecting the normal development of the brain. To date, a number of genes have been associated with ASD. However, the temporal and spatial co-expression of these genes in the brain remain unclear. To address this issue, we examined the co-expression network of 26 autism genes from AutDB (http://mindspec.org/autdb.html), in the framework of 3,041 genes whose expression energies have the highest correlation between the coronal and sagittal images from the Allen Mouse Brain Atlas database (http://mouse.brain-map.org). These data were derived from in situ hybridization experiments conducted on male, 56-day old C57BL/6J mice co-registered to the Allen Reference Atlas, and were used to generate a normalized co-expression matrix indicating the cosine similarity between expression vectors of genes in this database. The network formed by the autism-associated genes showed a higher degree of co-expression connectivity than seen for the other genes in this dataset (KolmogorovâSmirnov P = 5Ă10â28). Using Monte Carlo simulations, we identified two cliques of co-expressed genes that were significantly enriched with autism genes (A Bonferroni corrected P<0.05). Genes in both these cliques were significantly over-expressed in the cerebellar cortex (P = 1Ă10â5) suggesting possible implication of this brain region in autism. In conclusion, our study provides a detailed profiling of co-expression patterns of autism genes in the mouse brain, and suggests specific brain regions and new candidate genes that could be involved in autism etiology
Dissipation of angular momentum in light heavy ion collision
The inclusive energy distributions of fragments (4Z7) emitted in
the reactions O (116 MeV) + Al, Si, Ne (145 MeV) +
Al, Co have been measured in the angular range =
10 - 65. Fusion-fission and deep inelastic components of the
fragment emission have been extracted from the experimental data. The angular
mometum dissipations in fully damped deep inelastic collisions have been
estimated assming exit channel configuration similar to those for
fusion-fission process. It has been found that, the angular momentum
dissipations are more than those predicted by the empirical sticking limit in
all cases. The deviation is found to increase with increasing charge transfer
(lighter fragments). Qualitatively, this may be due to stronger friction in the
exit channel. Moreover, for the heavier system Ne + Co, the
overall magnitude of deviation is less as compared to those for the lighter
systems, {\it i.e.}, O + Al, Si, Ne + Al.
This may be due to lesser overlap in time scales of fusion and deep inelastic
time scales for heavier systems.Comment: 15 pages, 9 figures, accepted for publication in Phys. Rev.
A Comparative Note on Tunneling in AdS and in its Boundary Matrix Dual
For charged black hole, within the grand canonical ensemble, the decay rate
from thermal AdS to the black hole at a fixed high temperature increases with
the chemical potential. We check that this feature is well captured by a
phenomenological matrix model expected to describe its strongly coupled dual.
This comparison is made by explicitly constructing the kink and bounce
solutions around the de-confinement transition and evaluating the matrix model
effective potential on the solutions.Comment: 1+12 pages, 9 figure
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