2,065 research outputs found
Microwave Gaseous Discharges
Contains reports on three research projects.United States Atomic Energy Commission (Contract AT (30-1) 1842
Blue shifting of the A exciton peak in folded monolayer 1H-MoS2
The large family of layered transition-metal dichalcogenides is widely
believed to constitute a second family of two-dimensional (2D) semiconducting
materials that can be used to create novel devices that complement those based
on graphene. In many cases these materials have shown a transition from an
indirect bandgap in the bulk to a direct bandgap in monolayer systems. In this
work we experimentally show that folding a 1H molybdenum disulphide (MoS2)
layer results in a turbostratic stack with enhanced photoluminescence quantum
yield and a significant shift to the blue by 90 meV. This is in contrast to the
expected 2H-MoS2 band structure characteristics, which include an indirect gap
and quenched photoluminescence. We present a theoretical explanation to the
origin of this behavior in terms of exciton screening.Comment: 16 pages, 8 figure
Hierarchy and Feedback in the Evolution of the E. coli Transcription Network
The E.coli transcription network has an essentially feedforward structure,
with, however, abundant feedback at the level of self-regulations. Here, we
investigate how these properties emerged during evolution. An assessment of the
role of gene duplication based on protein domain architecture shows that (i)
transcriptional autoregulators have mostly arisen through duplication, while
(ii) the expected feedback loops stemming from their initial cross-regulation
are strongly selected against. This requires a divergent coevolution of the
transcription factor DNA-binding sites and their respective DNA cis-regulatory
regions. Moreover, we find that the network tends to grow by expansion of the
existing hierarchical layers of computation, rather than by addition of new
layers. We also argue that rewiring of regulatory links due to
mutation/selection of novel transcription factor/DNA binding interactions
appears not to significantly affect the network global hierarchy, and that
horizontally transferred genes are mainly added at the bottom, as new target
nodes. These findings highlight the important evolutionary roles of both
duplication and selective deletion of crosstalks between autoregulators in the
emergence of the hierarchical transcription network of E.coli.Comment: to appear in PNA
Heavy landings of Elops machnata from drift gill net at Tharuvaikulam landing centre, Tuticorin
On 18th September 2013, heavy landing of the
Indo-Pacific tarpon or tenpounder, Elops machnata
(Forsskal, 1775) was observed in multiday drift gill
net at Tharuvaikulam landing centre, Tuticorin. This
was locally called as “Kulanchan” or “Valaya
kulanchan”. It is also called as Poomeen or Mooran
kendai or Manna in different parts of Tamil Nadu.
These fishes were actually caught approximately
65 Nm southeast of Tharuvaikulam landing centre,
Tuticorin which is 23 Nm from Kannyakumari coast
at a depth ranged from 40-60 m
Droplet Fluctuations in the Morphology and Kinetics of Martensites
We derive a coarse grained, free-energy functional which describes droplet
configurations arising on nucleation of a product crystal within a parent. This
involves a new `slow' vacancy mode that lives at the parent-product interface.
A mode-coupling theory suggests that a {\it slow} quench from the parent phase
produces an equilibrium product, while a {\it fast} quench produces a
metastable martensite. In two dimensions, the martensite nuclei grow as
`lens-shaped' strips having alternating twin domains, with well-defined front
velocities. Several empirically known structural and kinetic relations drop out
naturally from our theory.Comment: 4 pages, REVTEX, and 3 .eps figures, compressed and uuencoded,
Submitted to Phys. Rev. Let
Recommended from our members
Efficient pricing of ratchet equity-indexed annuities in a variance-gamma economy
In this paper we propose a new method for approximating the price of arithmetic Asian options in a Variance-Gamma (VG) economy, which is then applied to the problem of pricing equityindexed annuity contracts. The proposed procedure is an extension to the case of a VG-based model of the moment-matching method developed by Turnbull and Wakeman and Levy for the pricing of this class of path-dependent options in the traditional Black-Scholes setting. The accuracy of the approximation is analyzed against RQMC estimates for the case of ratchet equityindexed annuities with index averaging
Functional outcome following conservative management of acetabular fractures
Background: Acetabular fractures are complex injuries caused due to high velocity injury and constitutes about 18 % of Pelvic fractures. To obtain articular congruency and anatomical reduction is the gold standard in treating these fractures. In this study we have studied about the functional outcome in acetabular fractures managed conservatively with the long-term follow.Methods: A retrospective study with prospective analysis done between 2011-2020 involved 39 patients with acetabular fractures who were treated conservatively at St John’s Medical college Hospital. Patients were followed up at 6 months, 1 year, 2 years and at the end of 5 years for functional evaluation and assessment with the clinical outcome scores with Merle d’Aubigne and Postel score & Harris Hip Score.Results: Study included 39 patients with the average age of 41.3 years with 31 male and 8 female patients. Functional outcome score showed good to excellent results in 80%, fair to satisfactory results in 18%, 0.5 to 2% had poor result in the patient analyzed with both Merle d’Aubigne and Postel score and Harris Hip Score. 80 % of the patients were able to sit cross legged, 90% had returned to regular work and 10% of the patients changed their occupation to desk jobs.Conclusions: Conservative management of acetabular fractures gives a good long-term result following congruent reduction of the fracture, good early rehabilitation and gradual weight bearing. Return to activity of daily living was good even in congruently reduced acetabular dome fractures with good to excellent functional outcome scores
Microwave Gaseous Discharges
Contains research objectives and reports on five research projects
Shape Deformation driven Structural Transitions in Quantum Hall Skyrmions
The Quantum Hall ground state away from can be described by a
collection of interacting skyrmions. We show within the context of a nonlinear
sigma model, that the classical ground state away from is a skyrmion
crystal with a generalized N\'eel order. We show that as a function of filling
, the skyrmion crystal undergoes a triangle to square to triangle
transition at zero temperature. We argue that this structural transition,
driven by a change in the shape of the individual skyrmions, is stable to
thermal and quantum fluctuations and may be probed experimentally.Comment: 4 pages (REVTEX) and 4 .eps figure
Human surfactant protein D alters oxidative stress and HMGA1 expression to induce p53 apoptotic pathway in eosinophil leukemic cell line
This article is made available through the Brunel Open Access Publishing Fund. Copyright: © 2013 Mahajan et al. 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.Surfactant protein D (SP-D), an innate immune molecule, has an indispensable role in host defense and regulation of
inflammation. Immune related functions regulated by SP-D include agglutination of pathogens, phagocytosis,
oxidative burst, antigen presentation, T lymphocyte proliferation, cytokine secretion, induction of apoptosis and
clearance of apoptotic cells. The present study unravels a novel ability of SP-D to reduce the viability of leukemic
cells (eosinophilic leukemic cell line, AML14.3D10; acute myeloid leukemia cell line, THP-1; acute lymphoid leukemia
cell lines, Jurkat, Raji; and human breast epithelial cell line, MCF-7), and explains the underlying mechanisms. SP-D
and a recombinant fragment of human SP-D (rhSP-D) induced G2/M phase cell cycle arrest, and dose and timedependent
apoptosis in the AML14.3D10 eosinophilic leukemia cell line. Levels of various apoptotic markers viz.
activated p53, cleaved caspase-9 and PARP, along with G2/M checkpoints (p21 and Tyr15 phosphorylation of cdc2)
showed significant increase in these cells. We further attempted to elucidate the underlying mechanisms of rhSP-D
induced apoptosis using proteomic analysis. This approach identified large scale molecular changes initiated by SPD
in a human cell for the first time. Among others, the proteomics analysis highlighted a decreased expression of
survival related proteins such as HMGA1, overexpression of proteins to protect the cells from oxidative burst, while a
drastic decrease in mitochondrial antioxidant defense system. rhSP-D mediated enhanced oxidative burst in
AML14.3D10 cells was confirmed, while antioxidant, N-acetyl-L-cysteine, abrogated the rhSP-D induced apoptosis.
The rhSP-D mediated reduced viability was specific to the cancer cell lines and viability of human PBMCs from
healthy controls was not affected. The study suggests involvement of SP-D in host’s immunosurveillance and
therapeutic potential of rhSP-D in the eosinophilic leukemia and cancers of other origins.Department of Biotechnology, Indi
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