1,424 research outputs found

    Shared Predictors of Academic Achievement in Children with ADHD: A Multi-Sample Study

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    Objective:To identify common and shared predictors of academic achievement across samples of children with ADHD.Method:Two clinically referred samples from New Zealand (1 n = 88, 82% boys; 2 n = 121, 79% boys) and two community samples from the United States (3 n = 111, 65% boys; 4 n = 114, 69% boys), completed similar diagnostic, cognitive and academic assessments. Hierarchical multiple regression analyses identified significant predictors of word reading, spelling, and math computation performance in each sample.Results:Entered after IQ, semantic language, age at testing, and verbal working memory emerged as consistent predictors of achievement across academic subjects and samples. Visual-spatial working memory contributed to variance in math performance only. Symptom severity explained limited variance.Conclusions:We recommend evaluations of children with ADHD incorporate assessments of working memory and language skills. Classroom/academic interventions should accommodate reduced working memory and address any identified language weaknesses

    The magnitude of a graph

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    The magnitude of a graph is one of a family of cardinality-like invariants extending across mathematics; it is a cousin to Euler characteristic and geometric measure. Among its cardinality-like properties are multiplicativity with respect to cartesian product and an inclusion-exclusion formula for the magnitude of a union. Formally, the magnitude of a graph is both a rational function over Q and a power series over Z. It shares features with one of the most important of all graph invariants, the Tutte polynomial; for instance, magnitude is invariant under Whitney twists when the points of identification are adjacent. Nevertheless, the magnitude of a graph is not determined by its Tutte polynomial, nor even by its cycle matroid, and it therefore carries information that they do not.Comment: 19 pages. Version 2: introduction rewritten; substance unchange

    Combustion particles emitted during church services: Implications for human respiratory health

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    Burning candles and incense generate particulate matter (PM) that produces poor indoor air quality and may cause human pulmonary problems. This study physically characterised combustion particles collected in a church during services. In addition, the emissions from five types of candles and two types of incense were investigated using a combustion chamber. The plasmid scission assay was used to determine the oxidative capacities of these church particles. The corresponding risk factor (CRf) was derived from the emission factor (Ef) and the oxidative DNA damage, and used to evaluate the relative respiratory exposure risks. Real-time PM measurements in the church during candle–incense burning services showed that the levels (91.6 μg/m3 for PM10; 38.9 μg/m3 for PM2.5) exceeded the European Union (EU) air quality guidelines. The combustion chamber testing, using the same environmental conditions, showed that the incense Ef for both PM10 (490.6– 587.9 mg/g) and PM2.5 (290.1–417.2 mg/g) exceeded that of candles; particularly the PM2.5 emissions. These CRf results suggested that the exposure to significant amounts of incense PM could result in a higher risk of oxidative DNA adducts (27.4–32.8 times) than tobacco PM. The generation and subsequent inhalation of PM during church activities may therefore pose significant risks in terms of respiratory health effects

    HIV risk behaviors among outpatients with severe mental illness in Rio de Janeiro, Brazil

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    We conducted the first study to examine rates of sexual activity, sexual risk behaviors, sexual protective behaviors, injection drug use (IDU), needle sharing, and knowledge about HIV/AIDS among outpatients with severe mental illness (SMI) in Rio de Janeiro, Brazil. Using a measure with demonstrated reliability, we found that 42% of 98 patients engaged in vaginal or anal sex within the past three months. Comorbid substance use disorder was significantly associated with sexual activity. Only 22% of sexually active patients used condoms consistently, despite having better HIV knowledge than those who were sexually abstinent. Overall, 45% of patients reported not engaging in any HIV protective behaviors. There were no reports of drug injection. Adults with SMI in Brazil are in need of efficacious HIV prevention programs and policies that can sustain these programs within mental health treatment settings

    Alteration in oxidative stress and F-actin assembly by incense particles

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    Research has indicated that the smoke from incense combustion contains toxic pollutants, such as particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5), metals and organic components, which have been associated with adverse human health effects. The physicochemistry of incense PM2.5 emitted from the three types of incense joss sticks (A-C) have been outlined in our previous study.1 The physicochemical characterization included particulate and gaseous emissions, as well as the determination of the inorganic compounds. The collected incense PM2.5 consisted of spherical singlets, chains and irregular-shaped aggregates (Figure 1). To understand the effects of oxidative stress in vitro caused by the incense PM2.5, A549 cells were exposed to the PM2.5 (± N-acetyl-L-cysteine, NAC).2 The cells significantly exhibited incense PM2.5 induced intracellular reactive oxygen species (ROS) formation (p<0.05; compared to background (BG) levels in a dose-dependent manner (Figure 2a), and a quadratic time response (Figure 2b). The increased levels of ROS production caused by incense PM2.5 were significantly reduced by the addition of NAC (p<0.05; Figures 2a, 2b), but the levels still persisted, especially at the higher concentrations of the incense PM2.5, when compared to the BG levels (p<0.05)

    Fabrication of a Flexible Micro Temperature Sensor for Micro Reformer Applications

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    Micro reformers still face obstacles in minimizing their size, decreasing the concentration of CO, conversion efficiency and the feasibility of integrated fabrication with fuel cells. By using a micro temperature sensor fabricated on a stainless steel-based micro reformer, this work attempts to measure the inner temperature and increase the conversion efficiency. Micro temperature sensors on a stainless steel substrate are fabricated using micro-electro-mechanical systems (MEMS) and then placed separately inside the micro reformer. Micro temperature sensors are characterized by their higher accuracy and sensitivity than those of a conventional thermocouple. To the best of our knowledge, micro temperature sensors have not been embedded before in micro reformers and commercial products, therefore, this work presents a novel approach to integrating micro temperature sensors in a stainless steel-based micro reformer in order to evaluate inner local temperature distributions and enhance reformer performance

    A categorification of quantum sl(2)

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    We categorify Lusztig's version of the quantized enveloping algebra for sl(2). Using a graphical calculus a 2-category is constructed whose split Grothendieck ring is isomorphic to Lusztig's algebra. The indecomposable morphisms of this 2-category lift Lusztig's canonical basis, and the Homs between 1-morphisms are graded lifts of a semilinear form defined on quantum sl(2). Graded lifts of various homomorphisms and antihomomorphisms of Lusztig's algebra arise naturally in the context of our graphical calculus. Using iterated flag varieties, a representation of the 2-category is constructed for each positive integer N. This representation categorifies the irreducible (N+1)-dimensional representation of quantum sl(2).Comment: 89 pages, LaTeX2e with xypic and pstricks macros v3. updates notation to match arXiv:0807.3250 and corrects misprint
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