35,453 research outputs found
Incidence of Behavior Problems in Toddlers and Preschool Children from Families Living in Poverty
Few studies have examined the incidence of behavior problems in toddlers and preschool children from families living in poverty. The available research suggests behavior problems occur at higher rates in children living in poverty and may have long-term negative outcomes if not identified and properly treated. This study included an ethnically representative sample of 357 children, five years of age and younger, from a diverse, low-income, urban area. All families’ incomes met the federal threshold for living in poverty. Behavior problems were assessed by parent report through a questionnaire specifically designed for low-income families. Boys and younger children were reported as demonstrating a higher rate of externalizing behaviors than girls and older children. The overall rate of children scoring at least one standard deviation above the sample\u27s mean for challenging behaviors was 17.4% and was not related to the child\u27s gender, age or ethnicity. This study also sampled children\u27s positive behaviors, which is unique in studies of behavior problems. Gender and age were not related to the frequency of reported positive behaviors. Ethnicity did influence scores on the positive scale. African American children appeared to present their parents more difficulty on items reflecting cooperative behaviors than Caucasian or Latino children. The implications of the study are discussed based on the recognized need for universal screening of behavior problems in young children and the small number professional training programs targeting the identification and treatment of early childhood behavior problems, despite the availability of evidence-based treatment programs tailored to young children in low-income families
Preferences of US and EU Undergraduates for Cloning
cloning, consumer preferences, Agribusiness, Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety,
Magnetic reconnection in plasma under inertial confinement fusion conditions driven by heat flux effects in Ohm's law
In the interaction of high-power laser beams with solid density plasma there
are a number of mechanisms that generate strong magnetic fields. Such fields
subsequently inhibit or redirect electron flows, but can themselves be advected
by heat fluxes, resulting in complex interplay between thermal transport and
magnetic fields.We show that for heating by multiple laser spots reconnection
of magnetic field lines can occur, mediated by these heat fluxes, using a fully
implicit 2D Vlasov-Fokker-Planck code. Under such conditions, the reconnection
rate is dictated by heat flows rather than Alfv\`enic flows. We find that this
mechanism is only relevant in a high plasma. However, the Hall
parameter can be large so that thermal transport is
strongly modified by these magnetic fields, which can impact longer time scale
temperature homogeneity and ion dynamics in the system
Do the electromagnetic fields generated by mobile-phone base-stations have short-term effects on health? A response to commentaries
Parenting Young Children: Comparison of a Psychoeducational Program in Mexico and the United States
The purpose of this study was to compare the cross-cultural effectiveness of a psychoeducational program with 82 Mexican and 63 American mothers with very young children. The 10-hour program was presented by trained facilitators in Mexico and the United States to small groups of mothers. Results showed that the both groups of mothers significantly increased their expectations and use of nurturing strategies and reduced their use of verbal and corporal punishment with their young children following the program. In addition, the reported frequency of child behavior problems decreased significantly at post-test. The similar results obtained across cultures were explained based on research finding similar parenting practices with young children between Mexican and American parents
A synaptic nidogen: developmental regulation and role of nidogen-2 at the neuromuscular junction
Background: The skeletal neuromuscular junction is a useful model for elucidating mechanisms that regulate synaptogenesis. Developmentally important intercellular interactions at the neuromuscular junction are mediated by the synaptic portion of a basal lamina that completely ensheaths each muscle fiber. Basal laminas in general are composed of four main types of glycosylated proteins: laminins, collagens IV, heparan sulfate proteoglycans and nidogens (entactins). The portion of the muscle fiber basal lamina that passes between the motor nerve terminal and postsynaptic membrane has been shown to bear distinct isoforms of the first three of these. For laminins and collagens IV, the proteins are deposited by the muscle; a synaptic proteoglycan, z-agrin, is deposited by the nerve. In each case, the synaptic isoform plays key roles in organizing the neuromuscular junction. Here, we analyze the fourth family, composed of nidogen-1 and -2.Results: In adult muscle, nidogen-1 is present throughout muscle fiber basal lamina, while nidogen- 2 is concentrated at synapses. Nidogen-2 is initially present throughout muscle basal lamina, but is lost from extrasynaptic regions during the first three postnatal weeks. Neuromuscular junctions in mutant mice lacking nidogen-2 appear normal at birth, but become topologically abnormal as they mature. Synaptic laminins, collagens IV and heparan sulfate proteoglycans persist in the absence of nidogen-2, suggesting the phenotype is not secondary to a general defect in the integrity of synaptic basal lamina. Further genetic studies suggest that synaptic localization of each of the four families of synaptic basal lamina components is independent of the other three.Conclusion: All four core components of the basal lamina have synaptically enriched isoforms. Together, they form a highly specialized synaptic cleft material. Individually, they play distinct roles in the formation, maturation and maintenance of the neuromuscular junction
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