The Relationship between Working Memory and Cognitive Functioning in Children

One-hundred and forty-four Year 1 children (51% boys and 49% girls, mean age 6) from Queensland State primary schools participated in a study to investigate the relationship between working memory and cognitive functioning. Children were given two tests of cognitive functioning (the School-Years Screening Test for the Evaluation of Mental Status (SYSTEMS) and the Kaufman Brief Intelligence Test (K-BIT)) and six subtests of working memory from the Working Memory Test Battery for Children (WMTB-C) (Backward Digit Recall, Listening Recall, Digit Recall, Word List Matching, Word List Recall and Non-word List Recall). The two cognitive tests correlated at r = .50. Results showed a high correlation between SYSTEMS and the Phonological Loop (PL) component of working memory. The K-BIT also correlated highly with PL component. The SYSTEMS and K-BIT showed various levels of correlation with the working memory sub-tests. A measurement model utilising Confirmatory Factor Analysis method showed a strong relationship between working memory and cognitive functioning, the degree of fit for the model was very high at GFI = .996

Pump-probe spectroscopy of photovoltaic materials

The study of photovoltaic materials is important so as to develop new solar energy technologies: in particular, quantum-confined semiconductors could offer increased quantum efficiencies at a much lower manufacture cost. This thesis contains results from a number of pump-probe experiments designed to probe the carrier dynamics in bulk and quantum-confined photovoltaics. A THz time-domain spectrometer was designed, built and commissioned. The THz refractive indices and absorption coefficients of toluene and hexane were determined, and the spectrometer was benchmarked using a photoexcited GaAs wafer. Results are presented of time-resolved THz spectroscopy of photoexcited bulk InP as a function of laser excitation wavelength. These data were used to extract the quantum efficiency of bulk InP in order to compare with recent results for InP quantum dots. The quantum efficiency in quantum dots increases when the incident photon energy is at least twice the band gap energy, whereasthe efficiency of the bulk material is found to decrease. This is because of surface recombination, and these measurements therefore verify the potential superiority of quantum dot materials over bulk materials for use in solar energy applications. Initial measurements of quantum dots using THz spectroscopy highlighted the various experimental challenges involved and the upgrades required to study such samples in the future.The time-dependence of the photoinduced surface photovoltage (SPV) in Si was studied on nanosecond timescales by synchronizing an ultrafast laser system to a synchrotron radiation source (the SRS at Daresbury, UK), and measuring the resulting shift in the photoelectron spectrum. The equilibrium band bending was determined, and the decay of the SPV was attributed to the recombination of charge carriers across the band gap. Results are presented for the SPV in bulk ZnO and for PbS quantum dot chemically attached to ZnO. The fact that the PbS quantum dots were chemically attached to the surface without becoming oxidized was verified using X-ray photoelectron spectroscopy (XPS). The changes caused by photoexcitation occur on much longer timescales in ZnO than Si (sub-milliseconds rather than nanoseconds), and these timescales were conveniently accessed using the time-resolved XPS facility at the TEMPO beamline at Synchrotron SOLEIL (Paris, France). This is due to oxygen adsorption and desorption processes at the ZnO surface affectingthe transfer of charge carriers. The addition of PbS quantum dots to the ZnO surface was found to increase the speed of this charge transfer due to injection of carriers directly from the PbS quantum dot to the bulk ZnO conduction band.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Language learning interventions

The writers of this article set out to explore the effectiveness and efficiency of a number of language learning interventions with students who failed a Senate discretionary access module designed to address the articulation gap between schooling and university. The article discusses various reasons for student failure despite language interventions. The students discussed in the first part of the article all visited the lecturers in the English for Specific Purposes Unit on more than one occasion for personal consultations. At these contact sessions, students were encouraged to make use of a number of language, reading and writing interventions within the system. Their use was optional and most of the students in the study did not avail themselves of the opportunities presented. On reflection, the conclusion reached by the lecturers was that students did not understand the amount of time that they needed to invest in their language development to be successful and to overcome the combined effects of previous experience and fossilization. They therefore applied to the university Senate to change the module from a semester to a year model to enable them, through a compulsory assignment system, to force students to put in the hours necessary to succeed. The results for that intervention show that the hypothesis was correct and students need more time and structure if they are to improve their language competence sufficiently.Keywords: language learning interventions, English for specific purposes, language competence, fossilizationJournal for Language Teaching Vol. 39(1) 2005: 114-13

Determinants of psychological distress in teenagers and young adults affected by cancer: a systematic review and meta-analysis. [Protocol]

The objective of this systematic review is to look at the key determinants of psychological distress in teenagers and young adults (TYAs) affected by cancer. Sources to be searched are MEDLINE, PsycINFO, CINAHL, the Cochrane Database of Systematic Reviews, EMBASE and PsycARTICLES. Any quantitative studies that assess the association among different factors (including individual and contextual types of factors commonly explored in the available literature in the subject area) with psychological distress will be included e.g. cross-sectional and longitudinal studies. Participants will be teenagers and young adults (TYA) a) aged 13-24 years at cancer diagnosis (in line with Teenage Cancer Trust’s definition b) at any stage of cancer, c) diagnosed with anxiety, depression, or/and PTSD or reported depressive/anxiety/PTSD symptomatology (on a validated self-report or clinician measure)

Functions of Social Networks in Maternal Food Choice for Children in Mexico

Food choice for children has important implications in establishing early-life dietary habits and preferences. Food choice for children has been studied as parent–child dyad dynamics, but little is known about the extended system of relationships in maternal food choice for children. The objective of this study was to understand the functions of mothers\u27 social networks in the food choices that mothers make for their children ages 1 to 5 years old in rural Mexico. In-depth interviews were conducted with 46 participants in three rural communities. The interviews inquired about participants\u27 child-feeding practices, personal and local beliefs about child feeding and the individuals with whom they had conversations about food and child feeding. All interviews were conducted in Spanish, audio-recorded, transcribed verbatim, verified for quality and analysed using the constant comparative method. Five interconnected networks emerged, consisting of household family, non-household family, community, children\u27s initial school and health and nutritional programme personnel. Each network had functions in food choice that ranged from shared food decision-making in the household family network to imparting formal dietary guidance in the health and nutritional programme personnel network. Across the networks, professionals, participants\u27 mothers and mothers-in-law, community senior women and other women with children emerged as prominent figures whom participants would turn to for child-feeding advice. These findings provide empirical evidence that social networks, as an organized system of interconnected relationships, have vital functions in establishing social norms for food choices made for children that can be leveraged to promote healthy food choices

The early postnatal period, mini-puberty, provides a window on the role of testosterone in human neurobehavioural development.

Experimental research in non-human mammals indicates that testosterone exposure during early periods of rapid brain development has enduring influences on brain and behaviour. These influences are exerted when testosterone is higher in developing males than females, and the affected characteristics are those that differ by sex. Testosterone is higher in males than in females from about weeks 8 to 24 of human gestation and then again during early infancy, and both of these periods are times of rapid brain development. Substantial evidence suggests that testosterone prenatally influences human neurobehavioral development. Emerging evidence suggests that the early postnatal period is important too. This early postnatal period could provide a window for studying testosterone interacting with experience to shape human gender development.The authors’ work on which this report was based was supported in part by the National Institutes of Health (HD24542), by the Economic and Social Research Council ((ES/J500033/1; ES/I901957/1; ES/H016406/1) and by the University of Cambridge.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Elsevier

Targeted Oral Delivery of Paclitaxel Using Colostrum-Derived Exosomes

Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small-cell lung cancer (NSCLC) is the most common type accounting for 84% of all lung cancers. Paclitaxel (PAC) is a widely used drug in the treatment of a broad spectrum of human cancers, including lung. While efficacious, PAC generally is not well tolerated and its limitations include low aqueous solubility, and significant toxicity. To overcome the dose-related toxicity of solvent-based PAC, we utilized bovine colostrum-derived exosomes as a delivery vehicle for PAC for the treatment of lung cancer. Colostrum provided higher yield of exosomes and could be loaded with higher amount of PAC compared to mature milk. Exosomal formulation of PAC (ExoPAC) showed higher antiproliferative activity and inhibition of colony formation against A549 cells compared with PAC alone, and also showed antiproliferative activity against a drug-resistant variant of A549. To further enhance its efficacy, exosomes were attached with a tumor-targeting ligand, folic acid (FA). FA-ExoPAC given orally showed significant inhibition (\u3e50%) of subcutaneous tumor xenograft while similar doses of PAC showed insignificant inhibition. In the orthotopic lung cancer model, oral dosing of FA-ExoPAC achieved greater efficacy (55% growth inhibition) than traditional i.v. PAC (24–32% growth inhibition) and similar efficacy as i.v. Abraxane (59% growth inhibition). The FA-ExoPAC given i.v. exceeded the therapeutic efficacy of Abraxane (76% growth inhibition). Finally, wild-type animals treated with p.o. ExoPAC did not show gross, systemic or immunotoxicity. Solvent-based PAC caused immunotoxicity which was either reduced or completely mitigated by its exosomal formulations. These studies show that a tumor-targeted oral formulation of PAC (FA-ExoPAC) significantly improved the overall efficacy and safety profile while providing a user-friendly, cost-effective alternative to bolus i.v. PAC and i.v. Abraxane

Integrins Form an Expanding Diffusional Barrier that Coordinates Phagocytosis

Phagocytosis is initiated by lateral clustering of receptors, which in turn activates Src-family kinases (SFKs). Activation of SFKs requires depletion of tyrosine phosphatases from the area of particle engagement. We investigated how the major phosphatase CD45 is excluded from contact sites, using single-molecule tracking. The mobility of CD45 increased markedly upon engagement of Fcγ receptors. While individual CD45 molecules moved randomly, they were displaced from the advancing phagocytic cup by an expanding diffusional barrier. By micropatterning IgG, the ligand of Fcγ receptors, we found that the barrier extended well beyond the perimeter of the receptor-ligand engagement zone. Second messengers generated by Fcγ receptors activated integrins, which formed an actin-tethered diffusion barrier that excluded CD45. The expanding integrin wave facilitates the “zippering” of Fcγ receptors onto the target and integrates the information from sparse receptor-ligand complexes, coordinating the progression and ultimate closure of the phagocytic cup