37 research outputs found

    School adaptation among immigrant youth from a Dutch integration program:The influence of acculturative stress and bicultural identity integration on academic motivation

    Get PDF
    Academic motivation represents a psychoeducational construct that is associated with the academic success of youth. For some immigrant youth, however, their academic motivation may be affected by the various challenges that they face during their settlement in a culturally diverse school that promotes different self-construal values and practices. The main goal of this study is to investigate the cultural match or mismatch between non-Western immigrant youth and the self-construal orientation typically promoted in Western schools, as well as how specific challenges associated with migration contribute to the development of different levels of academic motivation during their recent settlement. We hypothesize that non-Western immigrant youth experience cultural mismatch in a Western school, and that greater reports of migration challenges are associated with increases in levels of external motivation and decreases in levels of intrinsic motivation. To test these hypotheses, the present study was conducted among non-Western immigrant youth between 12 and 19 years old in their first year of attending a Dutch academic integration program in The Netherlands. Our findings highlight that non-Western immigrant youth are mismatched with the self-construal orientations typically promoted in Dutch schools, and that there is specificity in the way that migration challenges relate to different levels of academic motivation. These findings should be considered by Western educational stakeholders who aim to foster academic success for immigrant youth early on in their resettlement.</p

    Coulomb Interactions between Cytoplasmic Electric Fields and Phosphorylated Messenger Proteins Optimize Information Flow in Cells

    Get PDF
    Normal cell function requires timely and accurate transmission of information from receptors on the cell membrane (CM) to the nucleus. Movement of messenger proteins in the cytoplasm is thought to be dependent on random walk. However, Brownian motion will disperse messenger proteins throughout the cytosol resulting in slow and highly variable transit times. We propose that a critical component of information transfer is an intracellular electric field generated by distribution of charge on the nuclear membrane (NM). While the latter has been demonstrated experimentally for decades, the role of the consequent electric field has been assumed to be minimal due to a Debye length of about 1 nanometer that results from screening by intracellular Cl- and K+. We propose inclusion of these inorganic ions in the Debye-Huckel equation is incorrect because nuclear pores allow transit through the membrane at a rate far faster than the time to thermodynamic equilibrium. In our model, only the charged, mobile messenger proteins contribute to the Debye length.Using this revised model and published data, we estimate the NM possesses a Debye-Huckel length of a few microns and find this is consistent with recent measurement using intracellular nano-voltmeters. We demonstrate the field will accelerate isolated messenger proteins toward the nucleus through Coulomb interactions with negative charges added by phosphorylation. We calculate transit times as short as 0.01 sec. When large numbers of phosphorylated messenger proteins are generated by increasing concentrations of extracellular ligands, we demonstrate they generate a self-screening environment that regionally attenuates the cytoplasmic field, slowing movement but permitting greater cross talk among pathways. Preliminary experimental results with phosphorylated RAF are consistent with model predictions.This work demonstrates that previously unrecognized Coulomb interactions between phosphorylated messenger proteins and intracellular electric fields will optimize information transfer from the CM to the NM in cells

    Dynein-Dynactin Complex Is Essential for Dendritic Restriction of TM1-Containing Drosophila Dscam

    Get PDF
    BACKGROUND: Many membrane proteins, including Drosophila Dscam, are enriched in dendrites or axons within neurons. However, little is known about how the differential distribution is established and maintained. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated the mechanisms underlying the dendritic targeting of Dscam[TM1]. Through forward genetic mosaic screens and by silencing specific genes via targeted RNAi, we found that several genes, encoding various components of the dynein-dynactin complex, are required for restricting Dscam[TM1] to the mushroom body dendrites. In contrast, compromising dynein/dynactin function did not affect dendritic targeting of two other dendritic markers, Nod and Rdl. Tracing newly synthesized Dscam[TM1] further revealed that compromising dynein/dynactin function did not affect the initial dendritic targeting of Dscam[TM1], but disrupted the maintenance of its restriction to dendrites. CONCLUSIONS/SIGNIFICANCE: The results of this study suggest multiple mechanisms of dendritic protein targeting. Notably, dynein-dynactin plays a role in excluding dendritic Dscam, but not Rdl, from axons by retrograde transport

    Selective attention deficits in persons with autism: Preliminary evidence of an inefficient attentional lens.

    Full text link

    Selective attention deficits in persons with autism: Preliminary evidence of an inefficient attentional lens.

    No full text
    corecore