543 research outputs found

    Maanasa: An early individualized remedial educational intervention model for scholastic backwardness among upper primary students

    Get PDF
    Background: Scholastic backwardness is called as the learning achievement which is below the expected for a given age, cognitive skills, and schooling. Early identification and remedial measures are to be initiated at school level to control its lifelong impact. Objective: The objective of this study is to evolve an early individualized, remedial educational intervention model for the scholastic backwardness among upper primary students at the school level by the resource teachers. Materials and Methods: Whole upper primary students of the four government schools of the South Maararikkulam Grama Panchayath constituted the study population. The scholastic backwardness among them was identified and referred to specially trained resource teachers who were appointed in the schools under Maanasa project. They were graded as mild, moderate and severe category based on the level of scholastic backwardness. Children were given 1 academic year of individualized educational intervention along with inclusive education. Apart from these interventions, families of the identified students were given psychosocial interventions to create a learningfriendly atmosphere in their families. Learning skills of the scholastically backward students were re-assessed at the end of academicyear. Results: Out of total 629 students, 147 had scholastic backwardness (23.7%). Among these, 68 had mild, 60 moderate, and 19 had severe scholastic backwardness on reading skill grading. Psychosocial problems including alcoholism, domestic violence, quarrelsome events, and abandoned family were noticed among 48.7% of the parents of scholastically backward students. Reassessment at the end of academic year showed improvement of scholastic skill among 52.38% of the students. Conclusion: The present study proves that scholastic backwardness can be successfully approached and intervened at school level itself by impartingindividualized educational interventions by trained resource teachers. The parents should be taken into confidence for successful intervention

    Evaluation of sanguineous and crystalloid cardioplegic solutions during total heart-lung bypass in dogs

    Get PDF
    Twenty-four mongrel dogs were subjected to sanguineous and crystalloid cardioplegia for a period of thirty minutes at 20°C and 25°C systemic hypothermia during cardiopulmonary bypass. Cardioplegic solutions were administered at 4°C to induce cardioplegia. Physiological functions of the myocardium revealed that the cardiac function returned to normal sinus rhythm without any loss when blood cardioplegic solution was used at both hypothermic temperatures. The time taken for cardioplegia and cardiac electrical quiescence was achieved earlier at 20°C. Animals in sanguineous cardioplegic group revealed better functional return and revival of cardiac musculature in terms of lesser applications of defibrillator, lesser requirement of inotropic support and early cardiac contraction. This study revealed that sanguineous cardioplegic solution at a systemic temperature of 20°C was found to afford better myocardial protection during an arrest period of 30 minutes

    Study of Unsteadiness due to 3-D Shock-Boundary Layer Interaction in Flow over a Square-faced Protuberance

    Full text link
    The dynamics of shock-induced unsteady separated flow past a three-dimensional square-faced protuberance is investigated through wind tunnel experiments. Time-resolved schlieren imaging and unsteady surface pressure measurements are the diagnostics employed. Dynamic Mode Decomposition (DMD) of schlieren snapshots, and analysis of spectrum and correlations in pressure data are used to characterize and resolve the flow physics. The mean shock foot in the centreline is found to exhibit a Strouhal number of around 0.01, which is also the order of magnitude of the Strouhal numbers reported in the literature for two-dimensional shock-boundary layer interactions. The wall pressure spectra, in general, shift towards lower frequencies as we move away from (spanwise) centreline with some variation in the nature of peaks. The cross-correlation analysis depicts the strong dependence of the mean shock oscillations to the plateau region, and disturbances are found to travel upstream from inside the separation bubble. Good coherence is observed between the spanwise mean shock foot locations till a strouhal number of about 0.015 indicating that the 3-D shock foot largely moves to-and-fro in a coherent fashion.Comment: 16 pages, 21 figure

    Effect of salinity and pH on selected immune functions of the Indian white shrimp, Fenneropenaeus indicus (H. Milne Edwards, 1837)

    Get PDF
    The Indian white shrimp, Fenneropenaeus indicus, was subjected to environmental stresses like high (9) and low (5.5) water pH and decreasing water salinity (34 ‰ to 18 ‰) for a period of one week and certain vital immunological functions like total hemocyte count, total hemolymph protein and phenoloxidase activity were analysed to understand the effect of the environmental stress factors on these functions. The results indicated that while stress induced by change in the salinity had no damaging effects on the immune functions, stress caused by lower water pH induced more immunological damage when compared to higher water pH. Significantly decreased total hemocyte count and phenoloxidase activity were observed in shrimps exposed to lower pH when compared to shrimps exposed to higher pH and control shrimps. Also, lower pH significantly reduced the hemolymph protein values. It is therefore concluded that Fenneropenaeus indicus that are exposed to extreme pH show lowered immunological activity which would render the shrimp susceptible to infectious agents

    Breakdown of the Luttinger sum-rule at the Mott-Hubbard transition in the one-dimensional t1-t2 Hubbard model

    Full text link
    We investigate the momentum distribution function near the Mott-Hubbard transition in the one-dimensional t1-t2 Hubbard model (the zig-zag Hubbard chain), with the density-matrix renormalization-group technique. We show that for strong interactions the Mott-Hubbard transition occurs between the metallic-phase and an insulating dimerized phase with incommensurate spin excitations, suggesting a decoupling of magnetic and charge excitations not present in weak coupling. We illustrate the signatures for the Mott-Hubbard transition and the commensurate-incommensurate transition in the insulating spin-gapped state in their respective ground-state momentum distribution functions

    Observation of Pure Spin Transport in a Diamond Spin Wire

    Full text link
    Spin transport electronics - spintronics - focuses on utilizing electron spin as a state variable for quantum and classical information processing and storage. Some insulating materials, such as diamond, offer defect centers whose associated spins are well-isolated from their environment giving them long coherence times; however, spin interactions are important for transport, entanglement, and read-out. Here, we report direct measurement of pure spin transport - free of any charge motion - within a nanoscale quasi 1D 'spin wire', and find a spin diffusion length ~ 700 nm. We exploit the statistical fluctuations of a small number of spins (N\sqrt{N} < 100 net spins) which are in thermal equilibrium and have no imposed polarization gradient. The spin transport proceeds by means of magnetic dipole interactions that induce flip-flop transitions, a mechanism that can enable highly efficient, even reversible, pure spin currents. To further study the dynamics within the spin wire, we implement a magnetic resonance protocol that improves spatial resolution and provides nanoscale spectroscopic information which confirms the observed spin transport. This spectroscopic tool opens a potential route for spatially encoding spin information in long-lived nuclear spin states. Our measurements probe intrinsic spin dynamics at the nanometre scale, providing detailed insight needed for practical devices which seek to control spin.Comment: 7 pages, 2 figures, under consideration at Nature Nanotechnolog

    Frequency bands of strongly nonlinear homogeneous granular systems

    Get PDF
    Recent numerical studies on an infinite number of identical spherical beads in Hertzian contact showed the presence of frequency bands [ Jayaprakash, Starosvetsky, Vakakis, Peeters and Kerschen Nonlinear Dyn. 63 359 (2011)]. These bands, denoted here as propagation and attenuation bands (PBs and ABs), are typically present in linear or weakly nonlinear periodic media; however, their counterparts are not intuitive in essentially nonlinear periodic media where there is a complete lack of classical linear acoustics, i.e., in “sonic vacua.” Here, we study the effects of PBs and ABs on the forced dynamics of ordered, uncompressed granular systems. Through numerical and experimental techniques, we find that the dynamics of these systems depends critically on the frequency and amplitude of the applied harmonic excitation. For fixed forcing amplitude, at lower frequencies, the oscillations are large in amplitude and governed by strongly nonlinear and nonsmooth dynamics, indicating PB behavior. At higher frequencies the dynamics is weakly nonlinear and smooth, in the form of compressed low-amplitude oscillations, indicating AB behavior. At the boundary between the PB and the AB large-amplitude oscillations due to resonance occur, giving rise to collisions between beads and chaotic dynamics; this renders the forced dynamics sensitive to initial and forcing conditions, and hence unpredictable. Finally, we study asymptotically the near field standing wave dynamics occurring for high frequencies, well inside the AB

    In Vitro Evaluation of Notch Inhibition to Enhance Efficacy of Radiation Therapy in Melanoma

    Get PDF
    PURPOSE: The scope of radiation therapy is limited in melanoma. Using in vitro melanoma models, we investigated a Notch signaling inhibitor as a radiosensitizer to explore its potential to improve the efficacy of radiation therapy to widen the clinical application of radiation therapy in melanoma. METHODS AND MATERIALS: Melanoma cell lines A375, SKMEL28, and G361 were grown using standard tissue culture methods. Radiation was delivered with a clinical x-ray unit, and a gamma secretase inhibitor RO4929097 was used to inhibit Notch signaling. Cell viability signal was used to calculate Loewe’s combination index to assess the interaction between radiation and RO4929097 and also the effect of scheduling of radiation and RO4929097 on synergy. Clonogenic assays were used to assess the clonogenic potential. An in vitro 3-dimensional culture model, γ-H2AX, and notch intracellular domain assays were used to interrogate potential underlying biological mechanisms of this approach. Scratch and transwell migration assays were used to assess cell migration. RESULTS: A375 and SKMEL28 cell lines showed consistent synergy for most single radiation doses examined, with a tendency for better synergy with the radiation-first schedule (irradiation performed 24 hours before RO4929097 exposure). Clonogenic assays showed dose-dependent reduction in colony numbers. Both radiation and RO4929097 reduced the size of melanospheres grown in 3-dimensional culture in vitro, where RO4929097 demonstrated a significant effect on the size of A375 and SKMEL28 melanospheres, indicating potential modulation of stem cell phenotype. Radiation induced γ-H2AX foci signal levels were reduced after exposure to RO4929097 with a tendency toward reduction in notch intracellular domain levels for all 3 cell lines. RO4929097 impaired both de novo and radiation-enhanced cell migration. CONCLUSIONS: We demonstrate Notch signaling inhibition with RO4929097 as a promising strategy to potentially improve the efficacy of radiation therapy in melanoma. This strategy warrants further validation in vivo
    corecore