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Mindfulness is typically understood as non-judgmental, focused attention on the present moment, although it may be conceptualized as a state, a trait, and an outcome of intervention. There is a limited understanding of the physiological effects of state and trait mindfulness, and it has been a challenge to the research community to measure these effects. This study examined whether state and trait mindfulness are associated with reduced stress response activation in healthy young adults. Fifty-four undergraduate participants completed self-ratings of state and trait mindfulness, and continuous measures of psychophysiological reactivity (i.e., skin conductance response) before, during, and after an interview about a recurrent stressor. Results indicated that individuals with greater self-reported state mindfulness had lower sympathetic psychophysiological activation than those with lower state mindfulness. Moreover, those with greater self-reported state mindfulness experienced greater drops in psychophysiological activation following a stressful task. However, differences in psychophysiological activation were not evident when comparing those with higher and lower self-reported trait mindfulness. The findings suggest that state mindfulness, or "being in the moment", rather than trait mindfulness results in less engagement of metabolically costly psychophysiological activation in response to stress. Thus, intentional mindfulness during a stressful event may be important for decreasing sympathetic activation, resulting in lower bodily stress.
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Resposta Galvânica da Pele/fisiologia , Atenção Plena , Personalidade/fisiologia , Estresse Psicológico/fisiopatologia , Sistema Nervoso Simpático/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
BACKGROUND: Young adults who are not in employment, education, or training (NEET) are at risk of long-term economic disadvantage and social exclusion. Knowledge about risk factors for being NEET largely comes from cross-sectional studies of vulnerable individuals. Using data collected over a 10-year period, we examined adolescent predictors of being NEET in young adulthood. METHODS: We used data on 1938 participants from the Victorian Adolescent Health Cohort Study, a community-based longitudinal study of adolescents in Victoria, Australia. Associations between common mental disorders, disruptive behaviour, cannabis use and drinking behaviour in adolescence, and NEET status at two waves of follow-up in young adulthood (mean ages of 20.7 and 24.1 years) were investigated using logistic regression, with generalised estimating equations used to account for the repeated outcome measure. RESULTS: Overall, 8.5% of the participants were NEET at age 20.7 years and 8.2% at 24.1 years. After adjusting for potential confounders, we found evidence of increased risk of being NEET among frequent adolescent cannabis users [adjusted odds ratio (ORadj) = 1.74; 95% confidence interval (CI) 1.10-2.75] and those who reported repeated disruptive behaviours (ORadj = 1.71; 95% CI 1.15-2.55) or persistent common mental disorders in adolescence (ORadj = 1.60; 95% CI 1.07-2.40). Similar associations were present when participants with children were included in the same category as those in employment, education, or training. CONCLUSIONS: Young people with an early onset of mental health and behavioural problems are at risk of failing to make the transition from school to employment. This finding reinforces the importance of integrated employment and mental health support programmes.
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Comportamento do Adolescente , Sintomas Comportamentais/epidemiologia , Emprego/estatística & dados numéricos , Transtornos Mentais/epidemiologia , Estudantes/estatística & dados numéricos , Adolescente , Adulto , Feminino , Humanos , Estudos Longitudinais , Masculino , Vitória/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Ecological evidence suggests vitamin D insufficiency (VDI) due to lower ambient ultraviolet radiation (UVR) exposure may be a risk factor for IgE-mediated food allergy. However, there are no studies relating directly measured VDI during early infancy to subsequent challenge-proven food allergy. OBJECTIVE: To prospectively investigate the association between VDI during infancy and challenge-proven food allergy at 1 year. METHODS: In a birth cohort (n = 1074), we used a case-cohort design to compare 25-hydroxyvitamin D3 (25(OH)D3 ) levels among infants with food allergy vs a random subcohort (n = 274). The primary exposures were VDI (25(OH)D3 <50 nM) at birth and 6 months of age. Ambient UVR and time in the sun were combined to estimate UVR exposure dose. IgE-mediated food allergy status at 1 year was determined by formal challenge. Binomial regression was used to examine associations between VDI, UVR exposure dose and food allergy and investigate potential confounding. RESULTS: Within the random subcohort, VDI was present in 45% (105/233) of newborns and 24% (55/227) of infants at 6 months. Food allergy prevalence at 1 year was 7.7% (61/786), and 6.5% (53/808) were egg-allergic. There was no evidence of an association between VDI at either birth (aRR 1.25, 95% CI 0.70-2.22) or 6 months (aRR 0.93, 95% CI 0.41-2.14) and food allergy at 1 year. CONCLUSIONS: There was no evidence that VDI during the first 6 months of infancy is a risk factor for food allergy at 1 year of age. These findings primarily relate to egg allergy, and larger studies are required.
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Hipersensibilidade Alimentar/epidemiologia , Hipersensibilidade Alimentar/etiologia , Imunoglobulina E/imunologia , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/epidemiologia , Fatores Etários , Estudos de Casos e Controles , Estudos de Coortes , Dieta/efeitos adversos , Exposição Ambiental , Feminino , Humanos , Imunização , Lactente , Recém-Nascido , Masculino , Vigilância da População , Prevalência , Fatores de Risco , Raios Ultravioleta , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/etiologiaRESUMO
The effect of a tunable, externally coupled Fabry-Perot cavity to resonantly enhance the optical Hall effect signatures at terahertz frequencies produced by a traditional Drude-like two-dimensional electron gas is shown and discussed in this Letter. As a result, the detection of optical Hall effect signatures at conveniently obtainable magnetic fields, for example, by neodymium permanent magnets, is demonstrated. An AlInN/GaN-based high-electron mobility transistor structure grown on a sapphire substrate is used for the experiment. The optical Hall effect signatures and their dispersions, which are governed by the frequency and the reflectance minima and maxima of the externally coupled Fabry-Perot cavity, are presented and discussed. Tuning the externally coupled Fabry-Perot cavity strongly modifies the optical Hall effect signatures, which provides a new degree of freedom for optical Hall effect experiments in addition to frequency, angle of incidence, and magnetic field direction and strength.
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The electron optical phase contrast probed by electron holography at n-n+ GaN doping steps is found to exhibit a giant enhancement, in sharp contrast to the always smaller than expected phase contrast reported for p-n junctions. We unravel the physical origin of the giant enhancement by combining off-axis electron holography data with self-consistent electrostatic potential calculations. The predominant contribution to the phase contrast is shown to arise from the doping dependent screening length of the surface Fermi-level pinning, which is induced by FIB-implanted carbon point defects below the outer amorphous shell. The contribution of the built-in potential is negligible for modulation doping and only relevant for large built-in potentials at e.g. p-n junctions. This work provides a quantitative approach to so-called dead layers at TEM lamellas.
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Many enzymes display non-Arrhenius behavior with curved Arrhenius plots in the absence of denaturation. There has been significant debate about the origin of this behavior and recently the role of the activation heat capacity (ΔCP⧧) has been widely discussed. If enzyme-catalyzed reactions occur with appreciable negative values of ΔCP⧧ (arising from narrowing of the conformational space along the reaction coordinate), then curved Arrhenius plots are a consequence. To investigate these phenomena in detail, we have collected high precision temperature-rate data over a wide temperature interval for a model glycosidase enzyme MalL, and a series of mutants that change the temperature-dependence of the enzyme-catalyzed rate. We use these data to test a range of models including macromolecular rate theory (MMRT) and an equilibrium model. In addition, we have performed extensive molecular dynamics (MD) simulations to characterize the conformational landscape traversed by MalL in the enzyme-substrate complex and an enzyme-transition state complex. We have crystallized the enzyme in a transition state-like conformation in the absence of a ligand and determined an X-ray crystal structure at very high resolution (1.10 Å). We show (using simulation) that this enzyme-transition state conformation has a more restricted conformational landscape than the wildtype enzyme. We coin the term "transition state-like conformation (TLC)" to apply to this state of the enzyme. Together, these results imply a cooperative conformational transition between an enzyme-substrate conformation (ES) and a transition-state-like conformation (TLC) that precedes the chemical step. We present a two-state model as an extension of MMRT (MMRT-2S) that describes the data along with a convenient approximation with linear temperature dependence of the activation heat capacity (MMRT-1L) that can be used where fewer data points are available. Our model rationalizes disparate behavior seen for MalL and previous results for a thermophilic alcohol dehydrogenase and is consistent with a raft of data for other enzymes. Our model can be used to characterize the conformational changes required for enzyme catalysis and provides insights into the role of cooperative conformational changes in transition state stabilization that are accompanied by changes in heat capacity for the system along the reaction coordinate. TLCs are likely to be of wide importance in understanding the temperature dependence of enzyme activity and other aspects of enzyme catalysis.
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CONTEXT: No study has documented how symptomatic morbidity varies across the body mass index (BMI) spectrum (underweight, normal weight, overweight and obese) or across the entire child and adolescent age range. OBJECTIVE: To (1) quantify physical and psychosocial morbidities experienced by 2-18-year-olds according to BMI status and (2) explore morbidity patterns by age. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional data from two Australian population studies (the Longitudinal Study of Australian Children and the Health of Young Victorians Study) were collected during 2000-2006. Participants were grouped into five age bands: 2-3 (n=4606), 4-5 (n=4983), 6-7 (n=4464), 8-12 (n=1541) and 13-18 (n=928) years. MAIN MEASURES: Outcomes-Parent- and self-reported global health; physical, psychosocial and mental health; special health-care needs; wheeze; asthma and sleep problems. Exposure-measured BMI (kg m(-2)) categorised using standard international cutpoints. ANALYSES: The variation in comorbidities across BMI categories within and between age bands was examined using linear and logistic regression models. RESULTS: Comorbidities varied with BMI category for all except sleep problems, generally showing the highest levels for the obese category. However, patterns differed markedly between age groups. In particular, poorer global health and special health-care needs were associated with underweight in young children, but obesity in older children. Prevalence of poorer physical health varied little by BMI in 2-5-year-olds, but from 6 to 7 years was increasingly associated with obesity. Normal-weight children tended to experience the best psychosocial and mental health, with little evidence that the U-shaped associations of these variables with BMI status varied by age. Wheeze and asthma increased slightly with BMI at all ages. CONCLUSIONS: Deviation from normal weight is associated with health differences in children and adolescents that vary by morbidity and age. As well as lowering risks for later disease, promoting normal body weight appears central to improving the health and well-being of the young.
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Asma/epidemiologia , Saúde Mental/estatística & dados numéricos , Obesidade/epidemiologia , Transtornos do Sono-Vigília/epidemiologia , Magreza/epidemiologia , Adolescente , Serviços de Saúde do Adolescente , Análise de Variância , Austrália/epidemiologia , Índice de Massa Corporal , Criança , Proteção da Criança , Pré-Escolar , Comorbidade , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Modelos Logísticos , Masculino , Obesidade/psicologia , Razão de Chances , Pais , Vigilância de Evento Sentinela , Transtornos do Sono-Vigília/psicologia , Inquéritos e Questionários , Magreza/psicologiaRESUMO
Temperament and attention-deficit/hyperactivity disorder (ADHD) are both typically viewed as biologically based behavioural constructs. There is substantial overlap between ADHD symptoms and specific temperamental traits, such as effortful control, especially in young children. Recent work by Martel and colleagues ( 2009 , 2011 ) suggests that cognitive control temperamental processes are more closely related to inattention symptoms, whereas stimulus-driven temperamental processes are linked to hyperactivity-impulsivity. The present study tested a model of temperament and ADHD symptoms in typically developing preschoolers and those at risk for ADHD using structural equation modelling. Data were from larger study on ADHD in a short-term longitudinal sample with parent/teacher reports and neurocognitive testing. Participants included 214 preschool children (72.9% male) from diverse ethnic/racial backgrounds and a wide range of socioeconomic status from a large metropolitan center. Cognitive control processes, such as effortful control, but not stimulus-driven processes, are related to inattention and hyperactivity. In contrast, stimulus-driven processes, such as emotional reactivity, were related only to hyperactivity symptoms longitudinally. These results suggest that early temperament behaviours and cognitive processes may be indicators of later childhood behavioural difficulties with lasting consequences.
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Atenção , Comportamento Infantil/psicologia , Cognição , Hipercinese/psicologia , Modelos Psicológicos , Temperamento , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Pré-Escolar , Docentes , Feminino , Humanos , Comportamento Impulsivo/diagnóstico , Comportamento Impulsivo/psicologia , Estudos Longitudinais , Masculino , Pais , Instituições Acadêmicas , Inquéritos e QuestionáriosRESUMO
We report the design and optical characterization of fully suspended wire waveguides and photonic crystal (PhC) membranes fabricated on a gallium nitride layer grown on silicon substrate operating at 1.5 µm. W1-type PhC waveguides are coupled with suspended wires and are investigated using a standard end-fire setup. The experimental and theoretical dispersion properties of the propagating modes in the wires and photonic-crystal waveguides are shown. Modified L3 cavities with quality factors of up to 2200 and heterostructure cavities with quality factors of up to 5400 are experimentally demonstrated.
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BACKGROUND: Pre-school language impairment is common and greatly reduces educational performance. Population attempts to identify children who would benefit from appropriately timed intervention might be improved by greater knowledge about the typical profiles of language development. Specifically, this could be used to help with the early identification of children who will be impaired on school entry. METHODS: This study applied longitudinal latent class analysis to assessments at 8, 12, 24, 36 and 48 months on 1113 children from a population-based study, in order to identify classes exhibiting distinct communicative developmental profiles. RESULTS: Five substantive classes were identified: Typical, i.e. development in the typical range at each age; Precocious (late), i.e. typical development in infancy followed by high probabilities of precocity from 24 months onwards; Impaired (early), i.e. high probabilities of impairment up to 12 months followed by typical language development thereafter; Impaired (late), i.e. typical development in infancy but impairment from 24 months onwards; Precocious (early), i.e. high probabilities of precocity in early life followed by typical language by 48 months. The entropy statistic (0.84) suggested classes were fairly well defined, although there was a non-trivial degree of uncertainty in classification of children. That half of the Impaired (late) class was expected to have typical language at 4 years and 6% of the numerically large Typical class was expected to be impaired at 4 years illustrates this. Characteristics indicative of social advantage were more commonly found in the classes with improving profiles. CONCLUSIONS: Developmental profiles show that some pre-schoolers' language is characterized by periods of accelerated development, slow development and catch-up growth. Given the uncertainty in classifying children into these profiles, use of this knowledge for identifying children who will be impaired on school entry is not straightforward. The findings do, however, indicate greater need for language enrichment programmes among disadvantaged children.
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Desenvolvimento Infantil , Transtornos do Desenvolvimento da Linguagem/classificação , Desenvolvimento da Linguagem , Pré-Escolar , Escolaridade , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Instituições Acadêmicas , Fatores Socioeconômicos , VitóriaRESUMO
Despite significant investigation of fly ash spills and mineralogical controls on the release of potentially toxic elements (PTEs) from fly ash, interactions with the surficial environment remain relatively poorly understood. We conducted 90-day batch leaching studies with paired analysis of supernatant and solid-phase mineralogy to assess the elemental release and transformation of fly ash upon reaction with aquatic media (18 MΩ cm-1 water and simulated rainwater). The fly ash in this study, collected from the University of Alaska Fairbanks stoker-boiler power plant, is high in unburned carbon (~20% LOI) and highly enriched in several PTEs relative to the upper continental crust. Supernatant concentrations of oxyanion-forming elements (e.g., As, Se, Mo, Sb) remained relatively low and constant, suggesting equilibrium with the solid phase, possibly ettringite [Ca6Al2(SO4)3(OH)12â¢26H2O], which is known to incorporate and sorb oxyanion-forming PTEs and was identified by X-ray diffraction. Synthetic precipitation leaching procedure (SPLP) results failed to capture important temporal trends. Lead and Ba supernatant concentrations consistently exceeded drinking water standards, as well as others upon exposure to simulated physiological solutions. Seven-day experiments with dissolved organic matter-isolate solutions indicated that for certain elements, liberation was influenced by carbon concentration and/or the identity of the isolate. Overall, this paired approach can serve as a model for future studies, bridging existing gaps between batch leaching and single-element mineralogical, sorption, or speciation studies.
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Cinza de Carvão , Centrais Elétricas , Alaska , Carbono , Difração de Raios XRESUMO
BACKGROUND: Probiotic supplementation in early life may be effective for preventing eczema. Previous studies have suggested that prenatal administration may be particularly important for beneficial effects. OBJECTIVE: We examined whether prenatal treatment with the probiotic Lactobacillus rhamnosus GG (LGG) can influence the risk of eczema during infancy. METHODS: We recruited 250 pregnant women carrying infants at high risk of allergic disease to a randomized controlled trial of probiotic supplementation (LGG 1.8 × 10(10) cfu/day) from 36 weeks gestation until delivery. Infants were assessed during their first year for eczema or allergic sensitization. Immunological investigations were performed in a subgroup. Umbilical cord blood was examined for dendritic cell and regulatory T cell numbers and production of TGFß, IL-10, IL-12, IL-13, IFN-γ and TNFα. Maternal breast milk was examined for total IgA, soluble CD14 and TGFß. RESULTS: Prenatal probiotic treatment was not associated with reduced risk of eczema (34% probiotic, 39% placebo; RR 0.88; 95% CI 0.63, 1.22) or IgE-associated eczema (18% probiotic, 19% placebo; RR 0.94; 95% CI 0.53, 1.68). Prenatal probiotic treatment was not associated with any change in cord blood immune markers, but was associated with decreased breast milk soluble CD14 and IgA levels. CONCLUSIONS: Prenatal treatment with Lactobacillus rhamnosus GG was not sufficient for preventing eczema. If probiotics are effective for preventing eczema, then a postnatal component to treatment or possibly an alternative probiotic strain is necessary.
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Eczema/prevenção & controle , Lacticaseibacillus rhamnosus/imunologia , Efeitos Tardios da Exposição Pré-Natal/imunologia , Probióticos/uso terapêutico , Adulto , Eczema/epidemiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Sangue Fetal/química , Sangue Fetal/imunologia , Humanos , Lactente , Pessoa de Meia-Idade , Leite Humano/química , Leite Humano/imunologia , Gravidez , Adulto JovemRESUMO
BACKGROUND: Childhood sexual abuse (CSA) has been shown to be a risk factor for personality disorder (PD). However, no previous studies have examined whether associations exist between sexual abuse and abnormal personality as measured both categorically and dimensionally. Such enquiry would more fully illuminate the impact of CSA on adult personality. METHOD: Using a large nationally representative sample, we set out to examine associations between CSA and categorically defined PD. We also examined associations between CSA and the five dimensions of personality (openness to experience, conscientiousness, extraversion, agreeableness and neuroticism). A total of 1520 young adults were interviewed to determine the prevalence of sexual abuse occurring before age 16 years. A dimensional measure of personality was completed by 1469 participants, and 1145 had an informant-based PD assessment. RESULTS: PD was independently associated with repeated CSA [fully adjusted odds ratio (OR) 1.9, 95% confidence interval (CI) 1.1-3.4]. Repeated sexual abuse was also associated with higher neuroticism and lower agreeableness (p values for both <0.001). Adjusting for the effects of potential confounders and mediators, including earlier symptoms of anxiety and depression, had little impact on the strength of associations. CONCLUSIONS: We conclude that repeated CSA is independently associated with categorically defined PD, and also with higher neuroticism and lower agreeableness. Our findings suggest that if a dimensional classification of PDs is adopted in future classification systems, there might be meaningful continuity with previous aetiological research conducted using the current categorical system.
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Abuso Sexual na Infância/psicologia , Abuso Sexual na Infância/estatística & dados numéricos , Transtornos da Personalidade/epidemiologia , Transtornos da Personalidade/psicologia , Adolescente , Estudos de Coortes , Comorbidade , Estudos Transversais , Feminino , Seguimentos , Humanos , Masculino , Inventário de Personalidade/estatística & dados numéricos , Psicometria , Estatística como Assunto , Adulto JovemRESUMO
OBJECTIVES: In young infants, early development of symptomatic HIV infection increases the risk of morbidity and mortality. A prospective study was conducted over a 1-year period in a region with a high burden of HIV in order to describe the clinical presentation of HIV infection in infants aged between 0 and 59â days on attendance at hospital and the factors associated with the need for urgent hospital management. METHODS: Sick young infants presenting to the King Edward VIII Hospital, Durban between February 2003 and January 2004 were enrolled. After systematic evaluation by a primary health worker, an experienced paediatrician determined the primary diagnosis and need for urgent hospital management. Comparisons of these assessments were stratified by HIV status. Children were classified as HIV-uninfected (HIV ELISA-negative), HIV-exposed-but-uninfected (HIV ELISA-positive and HIV RNA PCR-negative), HIV-infected (HIV ELISA-positive and HIV viral load >400 copies/ml). RESULTS: Of 925 infants enrolled, 652 (70·5%) had their HIV status determined: 70 (10·7%) were HIV-infected, 271 (41·6%) HIV-exposed-but-uninfected, and 311 (47·7%) HIV-uninfected. Factors associated with an increased probability of being HIV-infected included if the mother had children from more than one sexual partner, if the infant had had contact with a tuberculosis-infected person or if the HIV-infected mother and/or her exposed infant failed to receive nevirapine prophylaxis. Signs of severe illness were more frequently encountered in HIV-infected than in HIV-exposed-but-uninfected infants, including the prevalence of chest in-drawing (20·3% vs 8·8%, p = 0·004) and severe skin pustules (18·6% vs 8·6%, p = 0·01). Among infants requiring urgent hospital management, observed or reported feeding difficulties and severe skin pustules were more common in HIV-infected than uninfected infants. More HIV-infected infants (12·9%) required hospitalisation than those who were HIV-exposed-but-uninfected (7·7%) or uninfected (7·4%). Primary diagnoses of pneumonia, sepsis or oral thrush were more frequently seen in HIV-infected than exposed-but-uninfected or HIV-uninfected children. CONCLUSION: Early recognition and triaging of infants suspected of having HIV infection provides an opportunity for early diagnosis and treatment which could prevent the adverse impact of rapidly progressive HIV disease.
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Infecções por HIV/complicações , Fármacos Anti-HIV/administração & dosagem , Fármacos Anti-HIV/uso terapêutico , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Lactente , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Masculino , Nevirapina/administração & dosagem , Nevirapina/uso terapêutico , África do SulRESUMO
Accumulating evidence suggests that parents may react differentially to children based on their children's temperament, children's gender, and the interaction of these factors. Furthermore, parents' differential reactions to their children have direct implications for their children's social success. The present study assessed the moderating influence of mothers' and fathers' psychological control on the relationship between shy temperament and peer exclusion in grade five children (n = 153; 57% female), an age during which peer connections are particularly salient. Teachers reported on children's shyness and peer exclusion, and children reported on parents' psychological control. Regression analyses showed fathers' psychological control to be associated with greater peer exclusion for males. Both mothers' and fathers' psychological control were associated with peer exclusion for shy females. Results suggest the importance of parents considering how psychologically controlling behaviors may work in concert with their children's gender and temperament in influencing peer connections during the adolescent transition.
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Poder Familiar/psicologia , Timidez , Criança , Estudos Transversais , Feminino , Humanos , Modelos Lineares , Masculino , Relações Pais-Filho , Grupo Associado , Fatores Sexuais , Isolamento Social/psicologia , Inquéritos e QuestionáriosRESUMO
Ultrafast nonlinear photonics enables a host of applications in advanced on-chip spectroscopy and information processing. These rely on a strong intensity dependent (nonlinear) refractive index capable of modulating optical pulses on sub-picosecond timescales and on length scales suitable for integrated photonics. Currently there is no platform that can provide this for the UV spectral range where broadband spectra generated by nonlinear modulation can pave the way to new on-chip ultrafast (bio-) chemical spectroscopy devices. We demonstrate the giant nonlinearity of UV hybrid light-matter states (exciton-polaritons) up to room temperature in an AlInGaN waveguide. We experimentally measure ultrafast nonlinear spectral broadening of UV pulses in a compact 100 µm long device and deduce a nonlinearity 1000 times that in common UV nonlinear materials and comparable to non-UV polariton devices. Our demonstration promises to underpin a new generation of integrated UV nonlinear light sources for advanced spectroscopy and measurement.
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A room temperature polariton condensate realized in a microcavity with embedded GaN quantum wells emits linearly polarized light at threshold with the plane of polarization pinned to one of the crystallographic axes. With increasing pumping power, a depinning of the polarization is observed resulting in a progressive decrease of the polarization degree of the emitted light. This depinning is understood in terms of polariton-polariton repulsion competing with the static disorder potential effect. The polarization behavior differs from that of conventional lasers where the polarization degree usually increases as a function of pumping power.
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OBJECTIVE: To evaluate the effectiveness of the 7-valent pneumococcal conjugate vaccine (PCV7) in preventing pneumonia, diagnosed radiologically according to World Health Organization (WHO) criteria, among indigenous infants in the Northern Territory of Australia. METHODS: We conducted a historical cohort study of consecutive indigenous birth cohorts between 1 April 1998 and 28 February 2005. Children were followed up to 18 months of age. The PCV7 programme commenced on 1 June 2001. All chest X-rays taken within 3 days of any hospitalization were assessed. The primary endpoint was a first episode of WHO-defined pneumonia requiring hospitalization. Cox proportional hazards models were used to compare disease incidence. FINDINGS: There were 526 pneumonia events among 10,600 children - an incidence of 3.3 per 1000 child-months; 183 episodes (34.8%) occurred before 5 months of age and 247 (47.0%) by 7 months. Of the children studied, 27% had received 3 doses of vaccine by 7 months of age. Hazard ratios for endpoint pneumonia were 1.01 for 1 versus 0 doses; 1.03 for 2 versus 0 doses; and 0.84 for 3 versus 0 doses. CONCLUSION: There was limited evidence that PCV7 reduced the incidence of radiologically confirmed pneumonia among Northern Territory indigenous infants, although there was a non-significant trend towards an effect after receipt of the third dose. These findings might be explained by lack of timely vaccination and/or occurrence of disease at an early age. Additionally, the relative contribution of vaccine-type pneumococcus to severe pneumonia in a setting where multiple other pathogens are prevalent may differ with respect to other settings where vaccine efficacy has been clearly established.
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Havaiano Nativo ou Outro Ilhéu do Pacífico , Vacinas Pneumocócicas/administração & dosagem , Vacinas Pneumocócicas/imunologia , Pneumonia Pneumocócica/diagnóstico por imagem , Pneumonia Pneumocócica/prevenção & controle , Fatores Etários , Austrália , Estudos de Coortes , Feminino , Humanos , Incidência , Lactente , Masculino , Pneumonia Pneumocócica/etnologia , Radiografia , Fatores de Tempo , Vacinas ConjugadasRESUMO
Objective: Mindfulness-based therapies (MBTs) have been shown to be efficacious in treating internally focused psychological disorders (e.g., depression); however, it is still unclear whether MBTs provide improved functioning and symptom relief for individuals with externalizing disorders, including ADHD. To clarify the literature on the effectiveness of MBTs in treating ADHD and to guide future research, an effect-size analysis was conducted. Method: A systematic review of studies published in PsycINFO, PubMed, and Google Scholar was completed from the earliest available date until December 2014. Results: A total of 10 studies were included in the analysis of inattention and the overall effect size was d = -.66. A total of nine studies were included in the analysis of hyperactivity/impulsivity and the overall effect was calculated at d = -.53. Conclusion: Results of this study highlight the possible benefits of MBTs in reducing symptoms of ADHD.
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Transtorno do Deficit de Atenção com Hiperatividade , Atenção Plena , Transtorno do Deficit de Atenção com Hiperatividade/terapia , Cognição , HumanosRESUMO
OBJECTIVE: To examine cognitive and psychosocial factors associated with high school dropout in urban adolescents with and without childhood ADHD. METHOD: In a longitudinal study, 49 adolescents/young adults with childhood ADHD and 44 controls who either dropped out or graduated from high school are included. Risk factors examined as potential correlates of dropout were intelligence, reading skills, socioeconomic status, marijuana use, and paternal contact. RESULTS: Lower IQ, reading ability, socioeconomic status, frequent marijuana use, and limited paternal contact significantly differentiated dropouts from graduates, irrespective of childhood ADHD. Follow-up analyses determined that IQ, marijuana use, and paternal contact independently contribute to the likelihood of dropout. CONCLUSION: Selected cognitive and psychosocial factors appear independently associated with the likelihood of high school dropout irrespective of ADHD. Notably, childhood ADHD did not increase this risk, suggesting that previous reports of increased dropout because of ADHD may become negated in urban areas when matched with similar community controls.