46,323 research outputs found

    Consequences of large impacts on Enceladus' core shape

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    International audienceThe intense activity on Enceladus suggests a differentiated interior consisting of a rocky core, an internal ocean and an icy mantle. However, topography and gravity data suggests large heterogeneity in the interior, possibly including significant core topography. In the present study, we investigated the consequences of collisions with large impactors on the core shape. We performed impact simulations using the code iSALE2D considering large differentiated impactors with radius ranging between 25 and 100 km and impact velocities ranging between 0.24 and 2.4 km/s. Our simulations showed that the main controlling parameters for the post-impact shape of Enceladus’ rock core are the impactor radius and velocity and to a lesser extent the presence of an internal water ocean and the porosity and strength of the rock core. For low energy impacts, the impactors do not pass completely through the icy mantle. Subsequent sinking and spreading of the impactor rock core lead to a positive core topographic anomaly. For moderately energetic impacts, the impactors completely penetrate through the icy mantle, inducing a negative core topography surrounded by a positive anomaly of smaller amplitude. The depth and lateral extent of the excavated area is mostly determined by the impactor radius and velocity. For highly energetic impacts, the rocky core is strongly deformed, and the full body is likely to be disrupted. Explaining the long-wavelength irregular shape of Enceladus’ core by impacts would imply multiple low velocity (<2.4 km/s) collisions with deca-kilometric differentiated impactors, which is possible only after the LHB period

    Evaluation of functioning of ICDS project areas under Indore and Ujjain divisions of the state of Madhya Pradesh

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    Background: Integrated Child Development Services (ICDS) is recognized worldwide as one of the most efficient community based programmes promoting early childhood care. Regular evaluations of the programme have been conducted to make it more effective and adequate for the beneficiaries. Objectives: To evaluate the functioning of the Anganwadi Centers under different project areas of Indore and Ujjain Divisions. Methods: Under the present evaluation system one ICDS project and five Anganwadi Centers under the project area (AWCs) were visited on a monthly basis and services provided reviewed. Findings reported are from nine project areas under Indore and Ujjain Divisions in the state of Madhya Pradesh from October 2008 – June 2009. Results: A total of 45 centers were evaluated. 29 centers were operating from rented buildings and storage facilities were lacking at 19 of the centers. Though the quality of food was acceptable to the beneficiaries shortage of food was a problem at the centers. Absence of Pre-School Education (PSE) and Nutrition and Health Education (NHED) Kits compromised PSE and NHED activities at the centers. Unavailability of medicine kits, lack of regular visits by the ANMs to the centers and absence of routine health check up of beneficiaries were other problems encountered under the project areas surveyed. Availability of a doctor under each project area was stated as a major need by the workers. Conclusion: Coordinated steps catering to different services provided at the centers are needed to optimize the functioning of the ICDS scheme

    A 7-year follow-up of sacral anterior root stimulation for bladder control in patients with a spinal cord injury: quality of life and users' experiences\ud

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    Study design: Cross-sectional descriptive study.\ud \ud Objectives: To assess long-term effects and quality of life (QoL) of using sacral anterior root stimulation (SARS) in spinal cord injured patients.\ud \ud Setting: Neurosurgical and Urological Departments of a large teaching hospital and a large rehabilitation centre in the Netherlands.\ud \ud Methods: In all, 42 patients with complete spinal cord injury (SCI) implanted between 1987 and 2000 were included. A questionnaire was constructed to determine complications, technical failures and personal experiences of the patients. The Qualiveen questionnaire was used and the outcome was compared with data obtained from a reference group of 400 SCI patients with neurogenic bladder problems not using the bladder controller. The Qualiveen questionnaire measures disease-specific aspects in four domains with respect to limitations, constraints, fears and feelings and general QoL aspects, suitable for use in SCI patients with urinary disorders.\ud \ud Results: The results of 37 patients are presented. Our results with the bladder controller with respect to medical and technical complications and infection rates are similar to the results presented by others. From users' experiences, the most important advantages reported were a decreased infection rate (68%), improved social life (54%) and continence (54%). Comparison of the obtained results of our patient group with the Qualiveen questionnaire with a reference group not using the bladder controller indicates that the specific impact of urinary disorders in the four domains on QoL is reduced and that general QoL is improved.\ud \ud Conclusion: SARS is effective and safe for neurogenic bladder management in patients with complete SCI. Users' experiences are positive. Furthermore, this therapy seems to reduce the effects of urinary-disorder-specific QoL aspects, and to increase the QoL in general\u

    Accretion Disc Theory: From the Standard Model Until Advection

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    Accretion disc theory was first developed as a theory with the local heat balance, where the whole energy produced by a viscous heating was emitted to the sides of the disc. One of the most important new invention of this theory was a phenomenological treatment of the turbulent viscosity, known as ''alpha'' prescription, when the (rϕ\phi) component of the stress tensor was approximated by (α\alpha P) with a unknown constant α\alpha. This prescription played the role in the accretion disc theory as well important as the mixing-length theory of convection for stellar evolution. Sources of turbulence in the accretion disc are discussed, including nonlinear hydrodynamical turbulence, convection and magnetic field role. In parallel to the optically thick geometrically thin accretion disc models, a new branch of the optically thin accretion disc models was discovered, with a larger thickness for the same total luminosity. The choice between these solutions should be done of the base of a stability analysis. The ideas underlying the necessity to include advection into the accretion disc theory are presented and first models with advection are reviewed. The present status of the solution for a low-luminous optically thin accretion disc model with advection is discussed and the limits for an advection dominated accretion flows (ADAF) imposed by the presence of magnetic field are analysed.Comment: Roceeding of the Int. Workshop "Observational Evidence for Black Holes in the Universe". Calcutta, 11-17 January 1998. Kluwer Acad. Pu

    An assessment of the human nail plate pH.

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    Purpose of Study: To measure the pH of the surface of healthy nail plates. Procedures: The surface pH of human fingernails and big toenails was measured in vivo using a skin pH meter. The influence of washing, anatomical site (fingers/toes), side (left/right), digit (digits 1–5) and gender was determined. The pH of the nail interior was also measured. Results: The pH of the nail plate surface was around 5, with toenails having a significantly higher pH than fingernails. Immediately after hand washing, the nail surface pH increased significantly, from pH 5.1 ± 0.4 to 5.3 ± 0.5. However, this was not sustained with time, and the pH returned to prewashing levels within 20 min. Gender had an influence on unwashed, but not washed, nail plate pH. The pH of the nail plate interior was lower than that of its surface. Conclusions: It was possible to measure nail plate pH, and baseline values are provided
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