Active fixturing: literature review and future research directions

Fixtures are used to fixate, position and support workpieces and represent a crucial tool in manufacturing. Their performance determines the result of the whole manufacturing process of a product. There is a vast amount of research done on automatic fixture layout synthesis and optimisation and fixture design verification. Most of this work considers fixture mechanics to be static and the fixture elements to be passive. However, a new generation of fixtures has emerged that has actuated fixture elements for active control of the part–fixture system during manufacturing operations to increase the end product quality. This paper analyses the latest studies in the field of active fixture design and its relationship with flexible and reconfigurable fixturing systems. First, a brief introduction is given on the importance of research of fixturing systems. Secondly, the basics of workholding and fixture design are visited, after which the state-of-the-art in active fixturing and related concepts is presented. Fourthly, part–fixture dynamics and design strategies which take these into account are discussed. Fifthly, the control strategies used in active fixturing systems are examined. Finally, some final conclusions and prospective future research directions are presented

Perception of Parenting Style by Children with ADHD and Its Relation with Inattention, Hyperactivity/Impulsivity and Externalizing Symptoms

Children’s perception of their parents’ behavior is very important for their adjustment. Raising a child with Attention-Deficit/Hyperactivity Disorder (ADHD) can be particularly challenging. However, little is known about how children with ADHD perceive their parents’ childrearing style. The main purpose of this paper is to study how children with ADHD perceive acceptance and control in parent–child relationships and this perception’s relationship with inattention, hyperactivity/impulsivity, and externalizing behaviors. Participants were children between 7 and 13 years old with ADHD who were attending psychotherapy (ADHD), children without ADHD who were attending psychotherapy (APG), and children with unknown ADHD status who were not attending psychotherapy (NPG). Furthermore, one parent of each child participated in the study. An analysis of variance (ANOVA) showed that children with ADHD perceived higher levels of pathological control in their relationships with their mothers than did APG and NPG children. NPG children perceived higher extreme autonomy than ADHD and APG children. Linear regression analyses revealed that the perception of pathological parental control and extreme autonomy predicted externalizing symptoms in children with ADHD. The perception of maternal acceptance and pathological control predicted inattention in APG children. Also, perceived maternal pathological control and perceived paternal acceptance predicted externalizing symptoms in APG children. Thus, these results show the importance of taking into account children’s perception of their relationships with their parents in addition to parental reports of their own behavior.Fil: Molina, María Fernanda. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Musich, Francisco Martín. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; Argentina. Universidad Favaloro; Argentin

What are the parenting experiences of fathers? The use of household survey data to inform decisions about the delivery of evidence-based parenting interventions to fathers

Participants were 933 fathers participating in a large-scale household survey of parenting practices in Queensland Australia. Although the majority of fathers reported having few problems with their children, a significant minority reported behavioral and emotional problems and 5% reported that their child showed a potentially problematic level of oppositional and defiant behavior. Reports of child problems were associated with fathers' levels of personal stress and socioeconomic disadvantage. Approximately half of all fathers reported the use of one or more coercive parenting strategies (shouting and yelling, hitting the child with their hand or with an object) with fathers' use of hitting being associated with child behavior difficulties. Fathers reported low rates of help seeking or participation in parenting courses, with socially disadvantaged fathers being less likely to complete parenting programs than other fathers. Implications for research on increasing fathers' participation rates in parenting programs are discussed and directions for future research highlighted

Neural Signatures of Autism Spectrum Disorders: Insights into Brain Network Dynamics

Neuroimaging investigations of autism spectrum disorders (ASDs) have advanced our understanding of atypical brain function and structure, and have recently converged on a model of altered network-level connectivity. Traditional task-based functional magnetic resonance imaging (MRI) and volume-based structural MRI studies have identified widespread atypicalities in brain regions involved in social behavior and other core ASD-related behavioral deficits. More recent advances in MR-neuroimaging methods allow for quantification of brain connectivity using diffusion tensor imaging, functional connectivity, and graph theoretic methods. These newer techniques have moved the field toward a systems-level understanding of ASD etiology, integrating functional and structural measures across distal brain regions. Neuroimaging findings in ASD as a whole have been mixed and at times contradictory, likely due to the vast genetic and phenotypic heterogeneity characteristic of the disorder. Future longitudinal studies of brain development will be crucial to yield insights into mechanisms of disease etiology in ASD sub-populations. Advances in neuroimaging methods and large-scale collaborations will also allow for an integrated approach linking neuroimaging, genetics, and phenotypic data