37,162 research outputs found

    Self-injurious behaviour in individuals with autism spectrum disorder

    Get PDF
    Background: Autism spectrum disorder (ASD) has been identified as a risk marker for self-injurious behaviour. In this study we aimed to describe the prevalence, topography and correlates of self-injury in individuals with ASD in contrast to individuals with Fragile X and Down syndromes and examine person characteristics associated with self-injury across and within these groups.\ud \ud Method: Carers of individuals with ASD (N=149; mean age=9.98, SD=4.86), Fragile X syndrome (N=123; mean age=15.32, SD=8.74) and Down syndrome (N=49; mean age=15.84, SD=12.59) completed questionnaires relating to the presence and topography of self-injury Information was also gathered regarding demographic characteristics, affect, autistic behaviour, hyperactivity, impulsivity and repetitive behaviour.\ud \ud Results: Self-injurious behaviour was displayed by 50% of the ASD sample; a significantly higher prevalence than in the Down syndrome group (18.4%) but broadly similar to the prevalence in Fragile X syndrome (54.5%). Self-injury was associated with significantly higher levels of autistic behaviour within the Down and Fragile X syndrome groups. Within the ASD group, the presence of self-injury was associated with significantly higher levels of impulsivity and hyperactivity, negative affect and significantly lower levels of ability and speech.\ud \ud Conclusions: Self-injurious behaviour is prevalent in individuals with ASD and the presence of ASD phenomenology increases the risk of self-injury in individuals with known genetic disorders but without a diagnosis of idiopathic autism. Person characteristics associated with self-injury in ASD indicate a role for impaired behavioural inhibition, low levels of ability and negative affect in the development of self-injurious behaviour

    Note on new interesting baryon channels to measure the photon polarization in b -> s gamma

    Full text link
    At LHC a large number of b-flavored baryons will be produced. In this note we propose new baryon modes to determine the photon helicity of the penguin transition bsγb \to s \gamma. The decay ΛbΛγ\Lambda_b \to \Lambda \gamma has the drawback that the Λ\Lambda, being neutral and long-lived, will escape detection most of the time. To overcome this difficulty, transitions of the type ΛbΛγ\Lambda_b \to \Lambda^{*} \gamma have been proposed, where Λ\Lambda^{*} denotes an excited state decaying strongly within the detector into the clean mode pKp K^-. The doublet Ξb\Xi_b, that decays weakly, has a number of good features. The charged baryon Ξb\Xi_b^- will decay into the mode Ξγ\Xi^- \gamma, where the ground state hyperon Ξ\Xi^-, although it will decay most of the time outside the detector, can be detected because it is charged. We consider also the decay of Ξb\Xi_b into Ξγ\Xi^{*} \gamma, where a higher mass state Ξ\Xi^{*} can decay strongly within the detector. We point out that the initial transverse polarization of Ξb\Xi_b has to be known in all cases. To determine this parameter through the transition ΞbJ/Ψ Ξ\Xi_b \to J/\Psi\ \Xi, we distinguish between different cases, and underline that in some situations one needs {\it theoretical input} on the asymmetry parameter αΞb\alpha_{\Xi_b} of the primary decay. {\it A fortiori} the same considerations apply to the case of the Λb\Lambda_b

    Bound on the curvature of the Isgur-Wise function of the baryon semileptonic decay Lambda_b -> Lambda_c + l + nu

    Full text link
    In the heavy quark limit of QCD, using the Operator Product Expansion, the formalism of Falk for hadrons or arbitrary spin, and the non-forward amplitude, as proposed by Uraltsev, we formulate sum rules involving the Isgur-Wise function ξΛ(w)\xi_{\Lambda} (w) of the baryon transition ΛbΛcν\Lambda_b \to \Lambda_c \ell \overline{\nu}_{\ell}, where the light cloud has jP=0+j^P=0^+ for both initial and final baryons. We recover the lower bound for the slope ρΛ2=ξΛ(1)0\rho_\Lambda^2 = - \xi '_\Lambda (1) \geq 0 obtained by Isgur et al., and we generalize it by demonstrating that the IW function ξΛ(w)\xi_{\Lambda} (w) is an alternate series in powers of (w1)(w-1), i.e. (1)nξΛ(n)(1)0(-1)^n \xi_{\Lambda}^{(n)} (1) \geq 0. Moreover, exploiting systematically the sum rules, we get an improved lower bound for the curvature in terms of the slope, σΛ2=ξ"Λ(1)35[ρΛ2+(ρΛ2)2]\sigma_\Lambda^2 = \xi "_\Lambda (1) \geq {3 \over 5} [\rho_\Lambda^2 + (\rho_\Lambda^2)^2]. This bound constrains the shape of the Isgur-Wise function and it will be compelling in the analysis of future precise data on the differential rate of the baryon semileptonic decay ΛbΛcν\Lambda_b \to \Lambda_c \ell \overline{\nu}_{\ell}, that has a large measured branching ratio, of about 5%.Comment: 16 page

    Layout level design for testability strategy applied to a CMOS cell library

    Get PDF
    The layout level design for testability (LLDFT) rules used here allow to avoid some hard to detect faults or even undetectable faults on a cell library by modifying the cell layout without changing their behavior and achieving a good level of reliability. These rules avoid some open faults or reduce their appearance probability. The main purpose has been to apply that set of LLDFT rules on the cells of the library designed at the Centre Nacional de Microelectronica (CNM) in order to obtain a highly testable cell library. The authors summarize the main results (area overhead and performance degradation) of the application of the LLDFT rules on the cell

    Boundary conditions for free surface inlet and outlet\ud problems

    Get PDF
    We investigate and compare the boundary conditions that are to be applied to free surface problems involving inlet and outlets of Newtonian fluid, typically found in coating processes. The flux of fluid is a priori known at an inlet, but unknown at an outlet, where it is governed by the local behaviour near the film-forming meniscus. In the limit of vanishing capillary number Ca it is well-known that the flux scales with Ca2/3, but this classical result is nonuniform as the contact angle approaches . By examining this limit we find a solution that is uniformly valid for all contact angles. Furthermore, by considering the far-field behaviour of the free surface we show that there exists a critical capillary number above which the problem at an inlet becomes over-determined. The implications of this result for the modelling of coating flows are discussed
    corecore