41,309 research outputs found

    Psychosis in Children: What is our present state of knowledge

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    Psychotic disorders are severe devastating illnesses that can seriously compromise the quality of life of many patients. Special considerations are needed for special patient populations such as, children and adolescents, as the developmental stage may greatly influence the clinical presentation and outcome. The vast bulk of research on psychosis has excluded children with psychotic disorders. The existence of childhood psychoses was discussed and denied for many years especially due to distinct definitions and different classifications that kept changing over time. Today, childhood psychosis is a well known entity (Tengan & Maia, 2004)

    Parenting, a Challenge in the New Millennium: Implications for Mental Health of Children

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    Adolescence is the transition phase between childhood and adulthood, characterized by psychological and biological changes, extending from the onset of puberty to the attainment of physical maturity and adulthood. In our country, it probably starts at 15 years when the preparations for entry into professional courses begin, and not at 11 years as mentioned in text books. Parenting is a complex activity that includes many specific behaviours that work individually or together to influence child outcomes. It prepares the child to enter into the next phase of life. When we compare the conventional role of a to-day’s child with that of yesterday, i.e. two decades back, we find a sea difference. Two decades ago children were reared in a relatively protected environment and taught to be subservient to their elders. The male child was expected to acquire modest education and make a career or else join the family profession. He was to be the bread winner, supposed to help in family work; and, if need be, take up family responsibilities at an early stage. The female child was taught to be submissive, tolerant and compliant; to acquire only minimal education, but to be proficient in domestic work (cooking, tailoring, home keeping etc.) so that she could adopt the primary role of a home maker. Most children did not have exposure to co-education. Introversion was encouraged, and mixing with the opposite sex considered a tabo

    A critical layer model for turbulent pipe flow

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    A model-based description of the scaling and radial location of turbulent fluctuations in turbulent pipe flow is presented and used to illuminate the scaling behaviour of the very large scale motions. The model is derived by treating the nonlinearity in the perturbation equation (involving the Reynolds stress) as an unknown forcing, yielding a linear relationship between the velocity field response and this nonlinearity. We do not assume small perturbations. We examine propagating modes, permitting comparison of our results to experimental data, and identify the steady component of the velocity field that varies only in the wall-normal direction as the turbulent mean profile. The "optimal" forcing shape, that gives the largest velocity response, is assumed to lead to modes that will be dominant and hence observed in turbulent pipe flow. An investigation of the most amplified velocity response at a given wavenumber-frequency combination reveals critical layer-like behaviour reminiscent of the neutrally stable solutions of the Orr-Sommerfeld equation in linearly unstable flow. Two distinct regions in the flow where the influence of viscosity becomes important can be identified, namely a wall layer that scales with R+1/2R^{+1/2} and a critical layer, where the propagation velocity is equal to the local mean velocity, that scales with R+2/3R^{+2/3} in pipe flow. This framework appears to be consistent with several scaling results in wall turbulence and reveals a mechanism by which the effects of viscosity can extend well beyond the immediate vicinity of the wall.Comment: Submitted to the Journal of Fluid Mechanics and currently under revie

    Heart Rate Extraction from Novel Neck Photoplethysmography Signals.

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    This paper demonstrates for the first time how heart rate (HR) can be extracted from novel neck photoplethysmography (PPG). A novel algorithm is presented, which when tested in neck PPG signals recorded from 9 subjects at different respiratory rates, obtained good precision with respect to gold standard ECG signals. Mean absolute error (MAE), standard deviation error (SDAE) and root-mean-square error (RMSE) resulted in 1.22, 1.54 and 1.98 beats per minute (BPM), respectively. HRneck estimation showed strong correlation (R=0.94) with reference HRECG. Good agreement between both techniques was also demonstrated by Bland-Altman analysis. The bias between mean HR paired differences was -0.16 BPM and 95% limits of agreement (LoA) were (-4.7, 4.4). Comparatively, for widely used finger PPG, errors were slightly smaller (MAE=0.38 BPM, SDAE=0.48 BPM, RMSE=0.62BPM) and the correlation with reference ECG was also very close to 1 (R=0.99). Bias of -0.04 BPM and 95% LoA (-1.5, 1.4), also showed high degree of agreement. However, these findings show the potential the neck could have as an alternative body location for wearable monitors, aiming to reduce the number of sensing sites whilst still providing access to a wide variety of physiological parameters

    Predicting structural and statistical features of wall turbulence

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    The majority of practical flows, particularly those flows in applications of importance to transport, distribution and climate, are turbulent and as a result experience complex three-dimensional motion with increased drag comparedwith the smoother, laminar condition. In this study, we describe the development of a simple model that predicts important structural and scaling features of wall turbulence. We show that a simple linear superposition of modes derived from a forcing-response analysis of the Navier-Stokes equations can be used to reconcile certain key statistical and structural descriptions of wall turbulence. The computationally cheap approach explains and predicts vortical structures and velocity statistics of turbulent flows that have previously been identified only in experiments or by direct numerical simulation. In particular, we propose an economical explanation for the meandering appearance of very large scale motions observed in turbulent pipe flow, and likewise demonstrate that hairpin vortices are predicted by the model. This new capability has clear implications for modeling, simulation and control of a ubiquitous class of wall flows

    Production of nuclei and antinuclei in pp and Pb-Pb collisions with ALICE at the LHC

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    We present first results on the production of nuclei and antinuclei such as (anti)deuterons, (anti)tritons, (anti)3He and (anti)4He in pp collisions at \s = 7 TeV and Pb-Pb collisions at \sNN = 2.76 TeV. These particles are identified using their energy loss (dE/dx) information in the Time Projection Chamber of the ALICE experiment. The Inner Tracking System gives a precise determination of the event vertex, by which primary and secondary particles are separated. The high statistics of over 360 million events for pp and 16 million events for Pb-Pb collisions give a significant number of light nuclei and antinuclei (Pb-Pb collisions: \sim30,000 anti-deuterons(dˉ\bar{d}) and \sim4 anti-alpha(4Heˉ\bar{^4He})). The predictions of various particle ratios from the THERMUS model is also discussed.Comment: 4 pages, 5 figures, parallel talk at Quark Matter 2011, May 23rd-28th 2011, Annecy, Franc

    Turbulence and Mixing in the Intracluster Medium

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    The intracluster medium (ICM) is stably stratified in the hydrodynamic sense with the entropy ss increasing outwards. However, thermal conduction along magnetic field lines fundamentally changes the stability of the ICM, leading to the "heat-flux buoyancy instability" when dT/dr>0dT/dr>0 and the "magnetothermal instability" when dT/dr<0dT/dr<0. The ICM is thus buoyantly unstable regardless of the signs of dT/drdT/dr and ds/drds/dr. On the other hand, these temperature-gradient-driven instabilities saturate by reorienting the magnetic field (perpendicular to r^\hat{\bf r} when dT/dr>0dT/dr>0 and parallel to r^\hat{\bf r} when dT/dr<0dT/dr<0), without generating sustained convection. We show that after an anisotropically conducting plasma reaches this nonlinearly stable magnetic configuration, it experiences a buoyant restoring force that resists further distortions of the magnetic field. This restoring force is analogous to the buoyant restoring force experienced by a stably stratified adiabatic plasma. We argue that in order for a driving mechanism (e.g, galaxy motions or cosmic-ray buoyancy) to overcome this restoring force and generate turbulence in the ICM, the strength of the driving must exceed a threshold, corresponding to turbulent velocities 10100km/s\gtrsim 10 -100 {km/s}. For weaker driving, the ICM remains in its nonlinearly stable magnetic configuration, and turbulent mixing is effectively absent. We discuss the implications of these findings for the turbulent diffusion of metals and heat in the ICM.Comment: 8 pages, 2 figs., submitted to the conference proceedings of "The Monster's Fiery Breath;" a follow up of arXiv:0901.4786 focusing on the general mixing properties of the IC
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