11,032 research outputs found
High level of hybridisation in three species of Indian major carps
Thirty individuals of each species of Indian major carps, i.e., Catla catla, Cirrhinus cirrhosus (C. mrigala) and Labeo rohita, obtained from a nursery near Mymensingh, Bangladesh were analysed by means of allozyme electrophoresis. Twenty-one loci were studied. Several loci revealed significant deviation from Hardy-Weinberg expectations caused by deficiency of heterozygotes, indicating Wahlund effects due to problems with species identification. Moreover, bimodal distributions of individual heterozygosity within the three putative species indicated hybridisation. This was confirmed using analysis of individual admixture proportions, as individuals misidentified to species and hybrids between species were observed. Furthermore, factorial correspondence analysis to visualize genetic relationships among individuals revealed three distinct groups containing misclassified individuals, along with some intermediate individuals interpreted as hybrids. Ten per cent of all C. catla and L. rohita had been erroneously identified to species, and 40 per cent of all presumptive C. catla were hybrids between C. catla x C. cirrhosus and C. catla x L. rohita. In the case of C. cirrhosus, 37 per cent of the samples were C. cirrhosus x L. rohita hybrids. Thirty per cent of all presumptive L. rohita turned out to be hybrids between L. rohita x C. catla and L. rohita x C. cirrhosus. The high incidence of hybrids in C. catla might be responsible for slower growth of the fish in aquaculture
SET based experiments for HTSC materials: II
The cuprates seem to exhibit statistics, dimensionality and phase transitions
in novel ways. The nature of excitations
[i.e. quasiparticle or collective], spin-charge separation, stripes [static
and dynamics], inhomogeneities, psuedogap, effect of impurity dopings [e.g. Zn,
Ni] and any other phenomenon in these materials must be consistently
understood. In this note we further discuss our original suggestion of using
Single Electron Tunneling Transistor
[SET] based experiments to understand the role of charge dynamics in these
systems. Assuming that SET operates as an efficient charge detection system we
can expect to understand the underlying physics of charge transport and charge
fluctuations in these materials for a range of doping. Experiments such as
these can be classed in a general sense as mesoscopic and nano characterization
of cuprates and related materials. In principle such experiments can show if
electron is fractionalized in cuprates as indicated by ARPES data. In contrast
to flux trapping experiments SET based experiments are more direct in providing
evidence about spin-charge separation. In addition a detailed picture of nano
charge dynamics in cuprates may be obtained.Comment: 10 pages revtex plus four figures; ICMAT 2001 Conference Symposium P:
P10-0
High level of hybridisation in three species of Indian major carps
Thirty individuals of each species of Indian major carps, i.e., Catla catla, Cirrhinus cirrhosus (C. mrigala) and Labeo rohita, obtained from a nursery near Mymensingh, Bangladesh were analysed by means of allozyme electrophoresis. Twenty-one loci were studied. Several loci revealed significant deviation from Hardy-Weinberg expectations caused by deficiency of heterozygotes, indicating Wahlund effects due to problems with species identification. Moreover, bimodal distributions of individual heterozygosity within the three putative species indicated hybridisation. This was confirmed using analysis of individual admixture proportions, as individuals misidentified to species and hybrids between species were observed. Furthermore, factorial correspondence analysis to visualize genetic relationships among individuals revealed three distinct groups containing misclassified individuals, along with some intermediate individuals interpreted as hybrids. Ten per cent of all C. catla and L. rohita had been erroneously identified to species, and 40 per cent of all presumptive C. catla were hybrids between C. catla x C. cirrhosus and C. catla x L. rohita. In the case of C. cirrhosus, 37 per cent of the samples were C. cirrhosus x L. rohita hybrids. Thirty per cent of all presumptive L. rohita turned out to be hybrids between L. rohita x C. catla and L. rohita x C. cirrhosus. The high incidence of hybrids in C. catla might be responsible for slower growth of the fish in aquaculture.Hybridization, DNA, Freshwater fish, Fish culture, Allozymes, Growth, Bangladesh, Catla catla, Cirrhinus cirrhosus, Cirrhinus mrigala, Labeo rohita
Quantum effects can render w<-1 on cosmological scales
We report on a revision of our previous computation of the renormalized
expectation value of the stress-energy tensor of a massless, minimally coupled
scalar with a quartic self-interaction on a locally de Sitter background. This
model is important because it demonstrates that quantum effects can lead to
violations of the weak energy condition on cosmological scales - on average,
not just in fluctuations - although the effect in this particular model is far
too small to be observed. The revision consists of modifying the propagator so
that dimensional regularization can be used when the dimension of the
renormalized theory is not four. Although the finite part of the stress-energy
tensor does not change (in D=4) from our previous result, the counterterms do.
We also speculate that a certain, finite and separately conserved part of the
stress tensor can be subsumed into a natural correction of the initial state
from free Bunch-Davies vacuum.Comment: 9 pages, references adde
Does cash for school influence young women's behavior in the longer term ? evidence from Pakistan
The Punjab Female School Stipend Program, a female-targeted conditional cash transfer program in Pakistan, was implemented in response to gender gaps in education. An early evaluation of the program shows that the enrollment of eligible girls in middle school increased in the short term by nearly 9 percentage points. This paper uses regression discontinuity and difference-in-difference analyses to show that five years into the program implementation positive impacts do persist. Beneficiary adolescent girls are more likely to progress through and complete middle school and work less. There is suggestive evidence that participating girls delay their marriage and have fewer births by the time they are 19 years old. Girls who are exposed to the program later, and who are eligible for the benefits given in high school, increase their rates of matriculating into and completing high school. The persistence of impacts can potentially translate into gains in future productivity, consumption, inter-generational human capital accumulation and desired fertility. Lastly, there is no evidence that the program has negative spillover effects on educational outcomes of male siblings.Education For All,Primary Education,Tertiary Education,Gender and Education,Disability
Quantum phase properties of photon added and subtracted displaced Fock states
Quantum phase properties of photon added and subtracted displaced Fock states
(and a set of quantum states which can be obtained as the limiting cases of
these states) are investigated from a number of perspectives, and it is shown
that the quantum phase properties are dependent on the quantum state
engineering operations performed. Specifically, the analytic expressions for
quantum phase distributions and angular distribution as well as measures of
quantum phase fluctuation and phase dispersion are obtained. The uniform phase
distribution of the initial Fock states is observed to be transformed by the
unitary operation (i.e., displacement operator) into non-Gaussian shape, except
for the initial vacuum state. It is observed that the phase distribution is
symmetric with respect to the phase of the displacement parameter and becomes
progressively narrower as its amplitude increases. The non-unitary (photon
addition/subtraction) operations make it even narrower in contrast to the Fock
parameter, which leads to broadness. The photon subtraction is observed to be a
more powerful quantum state engineering tool in comparison to the photon
addition. Further, one of the quantum phase fluctuation parameters is found to
reveal the existence of antibunching in both the engineered quantum states
under consideration. Finally, the relevance of the engineered quantum states in
the quantum phase estimation is also discussed, and photon added displaced Fock
state is shown to be preferable for the task.Comment: Quantum phase properties of an engineered quantum state has been
studied from various perspective
Lower- and higher-order nonclassical properties of photon added and subtracted displaced Fock states
Nonclassical properties of photon added and subtracted displaced Fock states
have been studied using various witnesses of lower- and higher-order
nonclassicality. Compact analytic expressions are obtained for the
nonclassicality witnesses. Using those expressions, it is established that
these states and the states that can be obtained as their limiting cases
(except coherent states) are highly nonclassical as they show the existence of
lower- and higher-order antibunching and sub-Poissonian photon statistics, in
addition to the nonclassical features revealed through the Mandel
parameter, zeros of Q function, Klyshko's criterion, and Agarwal-Tara
criterion. Further, some comparison between the nonclassicality of photon added
and subtracted displaced Fock states have been performed using witnesses of
nonclassicality. This has established that between the two types of
non-Gaussianity inducing operations (i.e., photon addition and subtraction)
used here, photon addition influences the nonclassical properties more
strongly. Further, optical designs for the generation of photon added and
subtracted displaced Fock states from squeezed vacuum state have also been
proposed.Comment: A comparative study of the nonclassicality present in photon added
and subtracted displaced Fock states shows photon addition is generally
preferable nonclassicality inducing operation, while subtraction also has
advantage in some cases over additio
Supervised machine learning based multi-task artificial intelligence classification of retinopathies
Artificial intelligence (AI) classification holds promise as a novel and
affordable screening tool for clinical management of ocular diseases. Rural and
underserved areas, which suffer from lack of access to experienced
ophthalmologists may particularly benefit from this technology. Quantitative
optical coherence tomography angiography (OCTA) imaging provides excellent
capability to identify subtle vascular distortions, which are useful for
classifying retinovascular diseases. However, application of AI for
differentiation and classification of multiple eye diseases is not yet
established. In this study, we demonstrate supervised machine learning based
multi-task OCTA classification. We sought 1) to differentiate normal from
diseased ocular conditions, 2) to differentiate different ocular disease
conditions from each other, and 3) to stage the severity of each ocular
condition. Quantitative OCTA features, including blood vessel tortuosity (BVT),
blood vascular caliber (BVC), vessel perimeter index (VPI), blood vessel
density (BVD), foveal avascular zone (FAZ) area (FAZ-A), and FAZ contour
irregularity (FAZ-CI) were fully automatically extracted from the OCTA images.
A stepwise backward elimination approach was employed to identify sensitive
OCTA features and optimal-feature-combinations for the multi-task
classification. For proof-of-concept demonstration, diabetic retinopathy (DR)
and sickle cell retinopathy (SCR) were used to validate the supervised machine
leaning classifier. The presented AI classification methodology is applicable
and can be readily extended to other ocular diseases, holding promise to enable
a mass-screening platform for clinical deployment and telemedicine.Comment: Supplemental material attached at the en
Transport coefficients for an inelastic gas around uniform shear flow: Linear stability analysis
The inelastic Boltzmann equation for a granular gas is applied to spatially
inhomogeneous states close to the uniform shear flow. A normal solution is
obtained via a Chapman-Enskog-like expansion around a local shear flow
distribution. The heat and momentum fluxes are determined to first order in the
deviations of the hydrodynamic field gradients from their values in the
reference state. The corresponding transport coefficients are determined from a
set of coupled linear integral equations which are approximately solved by
using a kinetic model of the Boltzmann equation. The main new ingredient in
this expansion is that the reference state (zeroth-order
approximation) retains all the hydrodynamic orders in the shear rate. In
addition, since the collisional cooling cannot be compensated locally for
viscous heating, the distribution depends on time through its
dependence on temperature. This means that in general, for a given degree of
inelasticity, the complete nonlinear dependence of the transport coefficients
on the shear rate requires the analysis of the {\em unsteady} hydrodynamic
behavior. To simplify the analysis, the steady state conditions have been
considered here in order to perform a linear stability analysis of the
hydrodynamic equations with respect to the uniform shear flow state. Conditions
for instabilities at long wavelengths are identified and discussed.Comment: 7 figures; previous stability analysis modifie
- …