70 research outputs found

    Detector Geometry Simulation Using GEANT4

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    Neutrino oscillation is an important phenomenon to explain the massive nature of neutrinos. this quantum mechanical phenomenon can be understood as mixing in quark sector just like the one we have in lepton sector. Observed deficit of solar neutrino flux is explained through neutrino oscillations and this study is the only way to investigate for small difference of neutrino masses thus gives signatures for the physics beyond Standard Model. Experimental results by Superkamiokande put a huge interest of experimentalists in neutrino field. In the present article after discussing the theoretical background of neutrinos and their status in standard model, latest important long baseline neutrino oscillations experiments as NOvA and lBNE has been discussed. Straw tube Detector, an important part of lBNE-near detector, has been reviewed the geometry of which is studied through a software geometry and tracking (geant4). using geant4, an important aspect of detector geometry and simulation has been studied

    Prevalence of stroke and related burden among older people living in Latin America, India and China

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    Objectives Despite the growing importance of stroke in developing countries, little is known of stroke burden in survivors. the authors investigated the prevalence of self-reported stroke, stroke-related disability, dependence and care-giver strain in Latin America (LA), China and India.Methods Cross-sectional surveys were conducted on individuals aged 65+ (n=15 022) living in specified catchment areas. Self-reported stroke diagnosis, disability, care needs and care giver burden were assessed using a standardised protocol. for those reporting stroke, the correlates of disability, dependence and care-giver burden were estimated at each site using Poisson or linear regression, and combined meta-analytically.Results the prevalence of self-reported stroke ranged between 6% and 9% across most LA sites and urban China, but was much lower in urban India (1.9%), and in rural sites in India (1.1%), China (1.6%) and Peru (2.7%). the proportion of stroke survivors needing care varied between 20% and 39% in LA sites but was higher in rural China (44%), urban China (54%) and rural India (73%). Comorbid dementia and depression were the main correlates of disability and dependence.Conclusion the prevalence of stroke in urban LA and Chinese sites is nearly as high as in industrialised countries. High levels of disability and dependence in the other mainly rural and less-developed sites suggest underascertainment of less severe cases as one likely explanation for the lower prevalence in those settings. As the health transition proceeds, a further increase in numbers of older stroke survivors is to be anticipated. in addition to prevention, stroke rehabilitation and long-term care needs should be addressed.Wellcome TrustWorld Health Organization (India, Dominican Republic and China)US Alzheimer's AssociationFONACIT/ CDCH/ UCV (Venezuela)Kings Coll London, Inst Psychiat, Epidemiol Sect, Hlth Serv, London SE5 8AF, EnglandKings Coll London, Inst Psychiat, Clin Neurosci Div, London SE5 8AF, EnglandUniv Nacl Pedro Henriquez Urena, Geriatr Sect, Santo Domingo, Dominican RepUniv Peruana Cayetano Heredia, Lima, PeruPeking Univ, Inst Mental Hlth, Div Social Psychiat & Behav Med, Beijing 100871, Peoples R ChinaChristian Med Coll & Hosp, Vellore, Tamil Nadu, IndiaMed Univ Havana, Dept Clin Sci, Havana, CubaCaracas Univ Hosp, Dept Med, Caracas, VenezuelaNatl Inst Neurol & Neurosurg Mexico, Mexico City, DF, MexicoVHS, Dept Community Hlth, Chennai, Tamil Nadu, IndiaUniversidade Federal de São Paulo, Dept Psychiat, São Paulo, BrazilUniv Ciencias Med Matanzas, Dept Internal Med, Matanzas, CubaKings Coll London, Inst Psychiat, Epidemiol Sect, Populat Res Dept, London SE5 8AF, EnglandUniversidade Federal de São Paulo, Dept Psychiat, São Paulo, BrazilWellcome Trust: GR066133Wellcome Trust: GR08002US Alzheimer's Association: IIRG-04-1286Web of Scienc

    “Soft that molds the hard:” Geometric morphometry of lateral atlantoaxial joints focusing on the role of cartilage in changing the contour of bony articular surfaces

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    Purpose: The existing literature on lateral atlantoaxial joints is predominantly on bony facets and is unable to explain various C1-2 motions observed. Geometric morphometry of facets would help us in understanding the role of cartilages in C1-2 biomechanics/kinematics. Objective: Anthropometric measurements (bone and cartilage) of the atlantoaxial joint and to assess the role of cartilages in joint biomechanics. Materials and Methods: The authors studied 10 cadaveric atlantoaxial lateral joints with the articular cartilage in situ and after removing it, using three-dimensional laser scanner. The data were compared using geometric morphometry with emphasis on surface contours of articulating surfaces. Results: The bony inferior articular facet of atlas is concave in both sagittal and coronal plane. The bony superior articular facet of axis is convex in sagittal plane and is concave (laterally) and convex medially in the coronal plane. The bony articulating surfaces were nonconcordant. The articular cartilages of both C1 and C2 are biconvex in both planes and are thicker than the concavities of bony articulating surfaces. Conclusion: The biconvex structure of cartilage converts the surface morphology of C1-C2 bony facets from concave on concavo-convex to convex on convex. This reduces the contact point making the six degrees of freedom of motion possible and also makes the joint gyroscopic

    Brain reserve and physical disability in secondary progressive multiple sclerosis

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    Background: The brain reserve hypothesis posits that larger maximal lifetime brain growth (MLBG) may confer protection against physical disability in multiple sclerosis (MS). Larger MLBG as a proxy for brain reserve, has been associated with reduced progression of physical disability in patients with early MS; however, it is unknown whether this association remains once in the secondary progressive phase of MS (SPMS). Our aim was to assess whether larger MLBG is associated with decreased physical disability progression in SPMS. Methods: We conducted a post hoc analysis of participants in the MS-Secondary Progressive Multi-Arm Randomisation Trial (NCT01910259), a multicentre randomised placebo-controlled trial of the neuroprotective potential of three agents in SPMS. Physical disability was measured by Expanded Disability Status Scale (EDSS), 9-hole peg test (9HPT) and 25-foot timed walk test (T25FW) at baseline, 48 and 96 weeks. MLBG was estimated by baseline intracranial volume (ICV). Multivariable time-varying Cox regression models were used to investigate the association between MLBG and physical disability progression. Results: 383 participants (mean age 54.5 years, 298 female) were followed up over 96 weeks. Median baseline EDSS was 6.0 (range 4.0-6.5). Adjusted for covariates, larger MLBG was associated with a reduced risk of EDSS progression (HR 0.84,95% CI:0.72 to 0.99;p=0.04). MLBG was not independently associated with time to progression as measured by 9HPT or T25FW. Conclusion: Larger MLBG is independently associated with physical disability progression over 96 weeks as measured by EDSS in SPMS. This suggests that MLBG as a proxy for brain reserve may continue to confer protection against disability when in the secondary progression phase of MS. Trail registration number: NCT01910259
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