5,822 research outputs found
Defect production due to quenching through a multicritical point
We study the generation of defects when a quantum spin system is quenched
through a multicritical point by changing a parameter of the Hamiltonian as
, where is the characteristic time scale of quenching. We argue
that when a quantum system is quenched across a multicritical point, the
density of defects () in the final state is not necessarily given by the
Kibble-Zurek scaling form , where is the
spatial dimension, and and are respectively the correlation length
and dynamical exponent associated with the quantum critical point. We propose a
generalized scaling form of the defect density given by , where the exponent determines the behavior of the
off-diagonal term of the Landau-Zener matrix at the multicritical
point. This scaling is valid not only at a multicritical point but also at an
ordinary critical point.Comment: 4 pages, 2 figures, updated references and added one figur
Neurocognitive functions in patients of major depression
A b s t r a c t : E a r l i e r s t u d i e s h a v e s h o w n c o n f l i c t i n g r e s u l t s r e g a r d i n g i m p a i r m e n t o f e x e c u t i v e f u n c t i o n s i n p a t i e n t s o f m a j o r d e p r e s s i o n
In-orbit Performance of UVIT on ASTROSAT
We present the in-orbit performance and the first results from the
ultra-violet Imaging telescope (UVIT) on ASTROSAT. UVIT consists of two
identical 38cm coaligned telescopes, one for the FUV channel (130-180nm) and
the other for the NUV (200-300nm) and VIS (320-550nm) channels, with a field of
view of 28 . The FUV and the NUV detectors are operated in the high
gain photon counting mode whereas the VIS detector is operated in the low gain
integration mode. The FUV and NUV channels have filters and gratings, whereas
the VIS channel has filters. The ASTROSAT was launched on 28th September 2015.
The performance verification of UVIT was carried out after the opening of the
UVIT doors on 30th November 2015, till the end of March 2016 within the
allotted time of 50 days for calibration. All the on-board systems were found
to be working satisfactorily. During the PV phase, the UVIT observed several
calibration sources to characterise the instrument and a few objects to
demonstrate the capability of the UVIT. The resolution of the UVIT was found to
be about 1.4 - 1.7 in the FUV and NUV. The sensitivity in various
filters were calibrated using standard stars (white dwarfs), to estimate the
zero-point magnitudes as well as the flux conversion factor. The gratings were
also calibrated to estimate their resolution as well as effective area. The
sensitivity of the filters were found to be reduced up to 15\% with respect to
the ground calibrations. The sensitivity variation is monitored on a monthly
basis. UVIT is all set to roll out science results with its imaging capability
with good resolution and large field of view, capability to sample the UV
spectral region using different filters and capability to perform variability
studies in the UV.Comment: 10 pages, To appear in SPIE conference proceedings, SPIE conference
paper, 201
Genome-wide identification and expression profile analysis of nuclear factor Y family genes in Sorghum bicolor L. (Moench)
Members of the plant Heme Activator Protein (HAP) or NUCLEAR FACTOR Y (NF-Y) are trimeric
transcription factor complexes composed of the NF-YA, NF-YB and NF-YC subfamilies.
They bind to the CCAAT box in the promoter regions of the target genes and regulate gene
expressions. Plant NF-Ys were reported to be involved in adaptation to several abiotic
stresses as well as in development. In silico analysis of Sorghum bicolor genome resulted in
the identification of a total of 42 NF-Y genes, among which 8 code for the SbNF-YA, 19 for
SbNF-YB and 15 for the SbNF-YC subunits. Analysis was also performed to characterize
gene structures, chromosomal distribution, duplication status, protein subcellular localizations,
conserved motifs, ancestral protein sequences, miRNAs and phylogenetic tree construction.
Phylogenetic relationships and ortholog predictions displayed that sorghum has additional
NF-YB genes with unknown functions in comparison with Arabidopsis. Analysis of promoters
revealed that they harbour many stress-related cis-elements like ABRE and HSE, but surprisingly,
DRE and MYB elements were not detected in any of the subfamilies. SbNF-YA1, 2, and
6 were found upregulated under 200 mM salt and 200 mM mannitol stresses. While NF-YA7
appeared associated with high temperature (40˚C) stress, NF-YA8 was triggered by both cold
(4˚C) and high temperature stresses. Among NF-YB genes, 7, 12, 15, and 16 were induced
under multiple stress conditions such as salt, mannitol, ABA, cold and high temperatures.
Likewise, NF-YC 6, 11, 12, 14, and 15 were enhanced significantly in a tissue specific manner
under multiple abiotic stress conditions. Majority of the mannitol (drought)-inducible genes
were also induced by salt, high temperature stresses and ABA. Few of the high temperature
stress-induced genes are also induced by cold stress (NF-YA2, 4, 6, 8, NF-YB2, 7, 10, 11, 12,
14, 16, 17, NF-YC4, 6, 12, and 13) thus suggesting a cross talk among them. This work paves
the way for investigating the roles of diverse sorghum NF-Y proteins during abiotic stress
responses and provides an insight into the evolution of diverse NF-Y members
MAGIC lines in chickpea: development and exploitation of genetic diversity
In chickpea a multi-parent advanced generation intercross (MAGIC) population was developed using eight parents that are improved varieties and widely adaptable breeding lines. The main objective was to enhance the genetic diversity and bring novel alleles for developing superior chickpea varieties. The development scheme involved a sequence of 28 two-way, 14 four-way and 7 eight-way crosses, followed by bulking of final F1 plants. From F2 generation onwards single plants were grown as progenies and advanced to F8 by single seed descent method. The finally developed 1136 MAGIC lines were phenotyped under rainfed (RF) and irrigated (IR) conditions for 2 years (2013 and 2014) under normal season, and one year under heat stress (HS) condition (summer-2014) in field to estimate the genetic diversity created among these lines. Under RF-2014, RF-2013, IR-2014, IR-2013 and S-2014 seasons 46, 62, 83, 50 and 61 lines showed significantly higher grain yield than the best parent, respectively. Similarly, 23 and 19 common lines were identified under RF and IR conditions over two years and no common line was identified between RF/IR and HS conditions. Preliminary evaluation showed a large variation among MAGIC lines for flowering time (34–69 days), maturity (80–120 days), plant height (23.3–65 cm), grain yield (179–4554 kg/ha), harvest index (0.10–0.77) and 100 seed weight (10–45 g) under RF and IR conditions. Several genotypes with higher grain yield than the best check under heat stress were identified. These MAGIC lines provide a useful germplasm source with diverse allelic combinations to global chickpea community
Summary of the Activities of the Working Group I on High Energy and Collider Physics
This is a summary of the projects undertaken by the Working Group I on High
Energy Collider Physics at the Eighth Workshop on High Energy Physics
Phenomenology (WHEPP8) held at the Indian Institute of Technology, Mumbai,
January 5-16, 2004. The topics covered are (i) Higgs searches (ii)
supersymmetry searches (iii) extra dimensions and (iv) linear collider.Comment: summary of Working Group I at the Eighth Workshop on High Energy
Physics Phenomenology (WHEPP8), I.I.T., Mumbai, January 5-16, 200
Enhancing lepton flavour violation in the supersymmetric inverse seesaw beyond the dipole contribution
In minimal supersymmetric models the -penguin usually provides
sub-dominant contributions to charged lepton flavour violating observables. In
this study, we consider the supersymmetric inverse seesaw in which the
non-minimal particle content allows for dominant contributions of the
-penguin to several lepton flavour violating observables. In particular, and
due to the low-scale (TeV) seesaw, the penguin contribution to, for instance,
\Br(\mu \to 3e) and conversion in nuclei, allows to render some of
these observables within future sensitivity reach. Moreover, we show that in
this framework, the -penguin exhibits the same non-decoupling behaviour
which had previously been identified in flavour violating Higgs decays in the
Minimal Supersymmetric Standard Model.Comment: 29 pages, 9 figures, 4 tables; v2: minor corrections, version to
appear in JHE
Phenomenology of Light Sneutrino Dark Matter in cMSSM/mSUGRA with Inverse Seesaw
We study the possibility of a light Dark Matter (DM) within a constrained
Minimal Supersymmetric Standard Model (cMSSM) framework augmented by a SM
singlet-pair sector to account for the non-zero neutrino masses by inverse
seesaw mechanism. Working within a 'hybrid' scenario with the MSSM sector fixed
at high scale and the singlet neutrino sector at low scale, we find that,
contrary to the case of the usual cMSSM where the neutralino DM cannot be very
light, we can have a light sneutrino DM with mass below 100 GeV satisfying all
the current experimental constraints from cosmology, collider as well as
low-energy experiments. We also note that the supersymmetric inverse seesaw
mechanism with sneutrino as the lightest supersymmetric partner can have
enhanced same-sign dilepton final states with large missing transverse energy
(mET) coming from the gluino- and squark-pair as well as the squark-gluino
associated productions and their cascade decay through charginos. We present a
collider study for the same-sign dilepton+jets+mET signal in this scenario and
propose some distinctions with the usual cMSSM. We also comment on the
implications of such a light DM scenario on the invisible decay width of an 125
GeV Higgs boson.Comment: 24 pages, 4 figures, 7 tables; matches published versio
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