1,257 research outputs found
Emergence of the fuzzy horizon through gravitational collapse
For a large enough Schwarzschild black hole, the horizon is a region of space
where gravitational forces are weak; yet it is also a region leading to
numerous puzzles connected to stringy physics. In this work, we analyze the
process of gravitational collapse and black hole formation in the context of
light-cone M theory. We find that, as a shell of matter contracts and is about
to reveal a black hole horizon, it undergoes a thermodynamic phase transition.
This involves the binding of D0 branes into D2's, and the new phase leads to
large membranes of the size of the horizon. These in turn can sustain their
large size through back-reaction and the dielectric Myers effect - realizing
the fuzzball proposal of Mathur and the Matrix black hole of M(atrix) theory.
The physics responsible for this phenomenon lies in strongly coupled 2+1
dimensional non-commutative dynamics. The phenomenon has a universal character
and appears generic.Comment: 24 pages, 4 figures; v2: minor clarifications, citations adde
Report of Acoustic Test on PSLV IS.1/2L Structure
The results of acoustic conducted on PSLV IS.1/2L at Acoustic Test Facility are briefly given. It contains test set up,
Instrumentation details and tables of spectral response
A Comparative Analysis of Age-Stage Two Sex Life Tables in Distinct Forms of Callosobruchus maculatus (F.): Insights into Population Dynamics and Reproductive Strategies
Callosobruchus maculatus, the bean weevil, is a fascinating insect that showcases remarkable adaptations for survival. Found in tropical and subtropical regions, it has become a global pest due to its adaptability and hitchhiking capabilities, causing substantial grain losses. This small beetle, part of the Chrysomelidae family, serves as a valuable model organism in entomology and agricultural research. One of the key aspects of Callosobruchus maculatus that captures the attention of scientists is its dichotomy between active and inactive forms. These two forms represent distinct survival strategies employed by the beetle to navigate its ever-changing environment. The present study provides a comprehensive overview of the study on Callosobruchus maculatus, highlighting the two distinct forms of the species, their adaptations, and the significance of understanding their lifetable parameters. It emphasizes the ecological, practical, and research-oriented implications of this study, ranging from ecological insights to pest management strategies and the optimization of mass multiplication protocols. These forms exhibited notable differences in various life history parameters and survival characteristics. Flightless-inactive females had longer preoviposition and oviposition period and laid a significantly higher average of eggs per female with higher reproduction potential. Female fecundity (eggs/female) was much lower in the flight-active form (18.6) than in the flightless-inactive form (84.10) and maintained constant survival rate. Life expectancy values were generally lower for the flightless-inactive form compared to the flight-active form across different stages and sexes. Both males and females in the flight-active form exhibited a consistent and relatively high life expectancy, with a 100% chance of survival throughout all age intervals. Overall, these findings provide a comprehensive understanding of the differences in life history traits, reproductive strategies, and survival patterns between the flight-active and flightless-inactive forms of Callosobruchus beetles in a controlled laboratory environment
3-(2-Methylbenzylidene)-2,3-dihydro-1,5-benzothiazepin-4(5H)-one
In the crystal structure of the title compound, C17H15NOS, the molecules form centrosymmetric dimers through pairs of N—H⋯O hydrogen bonds. The seven-membered ring adopts a distorted half-chair conformation
Entanglement entropy in lattice gauge theories
We report on the recent progress in theoretical and numerical studies of
entanglement entropy in lattice gauge theories. It is shown that the concept of
quantum entanglement between gauge fields in two complementary regions of space
can only be introduced if the Hilbert space of physical states is extended in a
certain way. In the extended Hilbert space, the entanglement entropy can be
partially interpreted as the classical Shannon entropy of the flux of the gauge
fields through the boundary between the two regions. Such an extension leads to
a reduction procedure which can be easily implemented in lattice simulations by
constructing lattices with special topology. This enables us to measure the
entanglement entropy in lattice Monte-Carlo simulations. On the simplest
example of Z2 lattice gauge theory in (2 + 1) dimensions we demonstrate the
relation between entanglement entropy and the classical entropy of the field
flux. For SU(2) lattice gauge theory in four dimensions, we find a signature of
non-analytic dependence of the entanglement entropy on the size of the region.
We also comment on the holographic interpretation of the entanglement entropy.Comment: Talk presented at the Confinement8 conference (Mainz, Germany,
September 1 - 6, 2008) and at the conference "Liouville Field Theory and
Statistical Models", dedicated to Alexey Zamolodchikov memory (Moscow,
Russia, June 21 - 24, 2008
Vacuum Boundary Effects
The effect of boundary conditions on the vacuum structure of quantum field
theories is analysed from a quantum information viewpoint. In particular, we
analyse the role of boundary conditions on boundary entropy and entanglement
entropy. The analysis of boundary effects on massless free field theories
points out the relevance of boundary conditions as a new rich source of
information about the vacuum structure. In all cases the entropy does not
increase along the flow from the ultraviolet to the infrared.Comment: 10 page
Gamma Radiation influence on Growth, Biochemical and Yield Characters of Cajanus cajan (L.) Millsp.
The present investigation deals with the effect of gamma radiation on growth, Biochemical and yield traits of Pigeon pea. The seeds of Pigeon pea Var.CO-7 were treated with different doses of gamma rays like 15, 20 and 25KR. The treated seeds were sown in field along with control to raise M1 generation and the radiation effects was noted from seed germination percentage, seedling survival (%), seedling height on 30th days, Days to first flower, plant height, (at maturity), number of branches, number of leaves, number of cluster, pollen viability (%), number of pods, seed yield, hundred seed weight (g), fresh and dry weight (g), Seed viability (%) and seed protein content (%). The results indicates that the growth, biochemical and yield parameters were gradually decreased when compare to control and the highest reduction was noted at higher doses of gamma radiation treatments. The pollen and seed viability (%) analysis were also reveled that gradually reduction in lower to higher doses of gamma rays treatments
Urtica dioica Induces Cytotoxicity in Human Prostate Carcinoma LNCaP Cells: Involvement of Oxidative Stress, Mitochondrial Depolarization and Apoptosis
Purpose: To evaluate the cytotoxic mechanisms of an extract from the leaves of the Urtica dioica (UD) plant in LNCaP prostate cancer cells.Methods: LNCaP cells were exposed to the UD extract for 24hrs and cell viability assessed using the MTT assay. Reactive oxygen species generation was assessed using the NBT assay and mitochondrial membrane potential using JCI-aggregation. DNA fragmentation patterns and cleavage of poly (ADPribose) polymerase were assessed using western blot and caspase activation via colorimetric assay.Results: The viability of LNCaP cells was significantly decreased in a dose-dependent manner following 24-h treatment with the UD extract. The reactive oxygen species levels were also significantly increased and mitochondrial depolarization was evident. DNA fragmentation, PARP cleavage and an increase in the activities of caspases 3 and 9 were observed in cells treated with the UD extract and this confirmed the induction of apoptosis as the major cytotoxic modality for this extract.Conclusion: The results confirm that the cytotoxic activity of UD aqueous extract in LNCaP cells is mediated through oxidative stress and apoptosis. These findings could hold positive implications for the potential use of UD extract in prostate cancer therapy.Keywords: Urtica dioica, Cytotoxicity, DNA fragmentation, PARP cleavage, Caspases, Prostate cance
Vortex Strings and Four-Dimensional Gauge Dynamics
We study the low-energy quantum dynamics of vortex strings in the Higgs phase
of N=2 supersymmetric QCD. The exact BPS spectrum of the stretched string is
shown to coincide with the BPS spectrum of the four-dimensional parent gauge
theory. Perturbative string excitations correspond to bound W-bosons and quarks
while the monopoles appear as kinks on the vortex string. This provides a
physical explanation for an observation by N. Dorey relating the quantum
spectra of theories in two and four dimensions.Comment: 23 pages, 1 figure. v2: Two extra appendices included: one on the
brane construction, the other describing the potential on the vortex moduli
space. Two figures added. Typos corrected and references added. v3: BPS
nature of quarks correcte
Chern-Simons Solitons, Chiral Model, and (affine) Toda Model on Noncommutative Space
We consider the Dunne-Jackiw-Pi-Trugenberger model of a U(N) Chern-Simons
gauge theory coupled to a nonrelativistic complex adjoint matter on
noncommutative space. Soliton configurations of this model are related the
solutions of the chiral model on noncommutative plane. A generalized
Uhlenbeck's uniton method for the chiral model on noncommutative space provides
explicit Chern-Simons solitons. Fundamental solitons in the U(1) gauge theory
are shaped as rings of charge `n' and spin `n' where the Chern-Simons level `n'
should be an integer upon quantization. Toda and Liouville models are
generalized to noncommutative plane and the solutions are provided by the
uniton method. We also define affine Toda and sine-Gordon models on
noncommutative plane. Finally the first order moduli space dynamics of
Chern-Simons solitons is shown to be trivial.Comment: latex, JHEP style, 23 pages, no figur
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