13,599 research outputs found
Impact of Rural-urban Labour Migration on Education of Children: A Case Study of Left behind and Accompanied Migrant Children in India
In developing countries, seasonal labour migration from rural to urban or from backward to developed region is a household livelihood strategy to cope with poverty. In this process, the children of those migrants are the worst affected whether they accompany their parents or are left behind in the villages. The present paper explores the impact of temporary labour migration of parent(s) on school attendance of the children between 6–14 years and their dropping out from the school through an analysis of the cases from both the ends of migration stream in India. Data was collected from thirteen construction sites of Varanasi Uttar Pradesh and nine villages of Bihar by applying both qualitative and quantitative techniques. It is evident from the study that the migrants through remittances improve school accessibility for the left behind children and bridge gender gap in primary school education. However, among the accompanying migrant children of construction workers, many remain out of school and many are forced to drop out and some of them become vulnerable to work as child labour due to seasonal mobility of their parents. Thus, mainstreaming these children in development process is a big challenge in attaining the goal of universal primary education and inclusive growth in the country like India
A fluorescence anisotropy study of tetramer-dimer equilibrium of λ repressor and its implication for function
Tetramer-dimer equilibrium of λ repressor has been studied by fluorescence anisotropy techniques. We have chosen 1-dimethylamino naphthalene-5-sulfonyl chloride (dansyl chloride)-labeled repressor to study the dissociation-association equilibrium, because of relatively long life-time of the probe (> 10 ns). Polarization of the dansyl-labeled repressor decreases with decreasing protein concentrations in the range of 20 to 0.2 μM. The decrease of anisotropy was shown to be due to reversible dissociation of the protein. Size exclusion high-performance liquid chromatography studies and polyacrylamide gel electrophoresis under native conditions (Ferguson plot) confirmed that at around 20 μM concentrations the repressor exists in predominantly tetrameric form, whereas in lower concentrations it exists in predominantly dimer form. A dissociation constant of 2.3 ± 0.9 μM was estimated in 0.1 M potassium phosphate, pH 8.0, at 25° C. A stoichiometric amount of isolated single operator shifted the tetramer-dimer equilibrium toward the dimer. Increased ionic strength had only a modest effect on the dissociation constant. The thermodynamic constants for the dissociation reaction calculated from the Van't Hoff plot was +26.6 kcal/mol for ΔH and +64.7 e.u. for ΔS. The rotational correlation times derived from isothermal Perrin plot indicated elongated dimers and tetramers
Supercooling across first-order phase transitions in vortex matter
Hysteresis in cycling through first-order phase transitions in vortex matter,
akin to the well-studied phenomenon of supercooling of water, has been
discussed in literature. Hysteresis can be seen while varying either
temperature T or magnetic field H (and thus the density of vortices). Our
recent work on phase transitions with two control variables shows that the
observable region of metastability of the supercooled phase would depend on the
path followed in H-T space, and will be larger when T is lowered at constant H
compared to the case when H is lowered at constant T. We discuss the effect of
isothermal field variations on metastable supercooled states produced by
field-cooling. This path dependence is not a priori applicable to metastability
caused by reduced diffusivity or hindered kinetics.Comment: Tex, 8 pages, 3 Postscripts figures. Submitted to Pramana - J.
Physic
Antifertility effect of curcumin, an indigenous medicine in rats
Background: Curcumin is an active constituent, obtained from rhizome of Curcuma longa linn, known to have broad medicinal properties, was studied for its effect on fertility in female rats. Curcumin has anti-ovulatory effect probably by its antiestrogenic activity through suppression of negative feedback of estrogen on pituitary.Methods: Inbred Charles Foster female albino rats (150-180 gm) were used for study. They were divided into different groups and treated with curcumin (25 mg/kg. and 50 mg/kg body weight) as per schedule. The antigonadotropic, antiestrogenic, anti-implantation and abortifacient effect on curcumin treated albino rats were demonstrated.Results: The results showed significant reduction in the number of implants and size of litters in curcumin treated rats compared to normal control group. The results were compared with Tamoxifen (10mg/ kg bodyweight) a known antifertility drug, which further substantiated the antifertility effects of curcumin.Conclusions: The results indicated the ways in which curcumin exerts antifertility effects and thus can play a vital role in fertility control
Learning Interpretable Temporal Properties from Positive Examples Only
We consider the problem of explaining the temporal behavior of black-boxsystems using human-interpretable models. To this end, based on recent researchtrends, we rely on the fundamental yet interpretable models of deterministicfinite automata (DFAs) and linear temporal logic (LTL) formulas. In contrast tomost existing works for learning DFAs and LTL formulas, we rely on onlypositive examples. Our motivation is that negative examples are generallydifficult to observe, in particular, from black-box systems. To learnmeaningful models from positive examples only, we design algorithms that relyon conciseness and language minimality of models as regularizers. To this end,our algorithms adopt two approaches: a symbolic and a counterexample-guidedone. While the symbolic approach exploits an efficient encoding of languageminimality as a constraint satisfaction problem, the counterexample-guided onerelies on generating suitable negative examples to prune the search. Both theapproaches provide us with effective algorithms with theoretical guarantees onthe learned models. To assess the effectiveness of our algorithms, we evaluateall of them on synthetic data.<br
An operator-induced conformational change in the C-terminal domain of the λ repressor
4,4'-bis(1-anilino-8-naphthalenesulfonic acid (Bis-ANS), an environment-sensitive fluorescent probe for hydrophobic region of proteins, binds specifically to the C-terminal domain of λ repressor. The binding is characterized by positive cooperativity, the magnitude of which is dependent on protein concentration in the concentration range where dimeric repressor aggregates to a tetramer. In this range, positive cooperativity becomes more pronounced at higher protein concentrations. This suggests a preferential binding of Bis-ANS to the dimeric form of the repressor. Binding of single operator OR1 to the N-terminal domain of the repressor causes enhancement of fluorescence of the C-terminal domain bound Bis-ANS. The binding of single operator OR1 also leads to quenching of fluorescence of tryptophan residues, all of which are located in the hinge or the C-terminal domain. Thus two different fluorescent probes indicate an operator-induced conformational change which affects the C-terminal domain. The significance of this conformational change with respect to the function of λ repressor has been discussed
Higgs as a pseudo-Goldstone boson, the mu problem and gauge-mediated supersymmetry breaking
We study the interplay between the spontaneous breaking of a global symmetry
of the Higgs sector and gauge-mediated supersymmetry breaking, in the framework
of a supersymmetric model with global SU(3) symmetry. In addition to solving
the supersymmetric flavour problem and alleviating the little hierarchy
problem, this scenario automatically triggers the breaking of the global
symmetry and provides an elegant solution to the mu/Bmu problem of gauge
mediation. We study in detail the processes of global symmetry and electroweak
symmetry breaking, including the contributions of the top/stop and gauge-Higgs
sectors to the one-loop effective potential of the pseudo-Goldstone Higgs
boson. While the joint effect of supersymmetry and of the global symmetry
allows in principle the electroweak symmetry to be broken with little
fine-tuning, the simplest version of the model fails to bring the Higgs mass
above the LEP bound due to a suppressed tree-level quartic coupling. To cure
this problem, we consider the possibility of additional SU(3)-breaking
contributions to the Higgs potential, which results in a moderate fine-tuning.
The model predicts a rather low messenger scale, a small tan beta value, a
light Higgs boson with Standard Model-like properties, and heavy higgsinos.Comment: 19 pages, 6 figures. New section 3.3 on the mu/Bmu problem, more
detailed analytic computation in section 4.1, error in Fig. 5 corrected,
significant redactional changes (including abstract, introduction and
conclusion) in order to better emphasize the main results of the paper. Title
changed in journal. Final version to appear in Eur. Phys. J.
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