4,381 research outputs found

    Do critical thinkers drink too much alcohol, forget to do class assignments, or cheat on exams? Using a critical thinking measure to predict college students’ real-world outcomes

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    Critical thinking is a higher-order way of reasoning composed of the skill and will to use cognitive abilities and knowledge on a daily basis. It is identified as essential by higher education institutions, corporations, and society in general. To analyze whether college students are critical thinkers in their daily lives, the Halpern Critical Thinking Assessment (HCTA; Halpern in Halpern Critical Thinking Assessment (Measurement instrument), Schuhfried, Mödling, 2012) and the real-world outcomes inventory (RWO; Butler in Appl Cogn Psychol 26(5):721–729, 2012) were administered to 238 students. We performed a cluster analysis (K-means-constrained clustering method), and ANOVAs for each cluster solution tested to identify the most suitable clustering solution, taking the RWO inventory dimensions as dependent variables and cluster membership as an independent variable. Four separate clusters emerged, each representing a different profile related to students’ everyday negative outcomes resulting from a lack of critical thinking. We performed multinomial logistic regression to examine which dimensions of the HCTA test, as well as gender, age, and disciplinary area, predicted the four singular groups of students that emerged: “Mature,” “Risk-taking,” “Lost in translation,” and “Reflective.” Results indicate that: (1) age is a relevant predictor of slackness, rashness, and health neglect, all characteristics of “Mature” students; (2) students who are particularly skilled in hypothesis testing tend to be “Risk-taking,” while it is less likely that students who are specifically competent in argument analysis will be in this group; (3) gender is relevant to predict “Lost in translation” students, while argument analysis is negatively related to the chances of being in this group. Our study supports the relevance of critical thinking in daily decisions and everyday outcomes.FCT -Fundação para a CiĂȘncia e a Tecnologia(Advanced Training)info:eu-repo/semantics/publishedVersio

    Lead and ÎŽ-Aminolevulinic Acid Dehydratase Polymorphism: Where Does It Lead? A Meta-Analysis

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    BACKGROUND: Lead poisoning affects many organs in the body. Lead inhibits ÎŽ-aminolevulinic acid dehydratase (ALAD), an enzyme with two co-dominantly expressed alleles, ALAD1 and ALAD2. OBJECTIVE: Our meta-analysis studied the effects of the ALAD polymorphism on a) blood and bone lead levels and b) indicators of target organ toxicity. DATA SOURCE: We included studies reporting one or more of the following by individuals with genotypes ALAD1-1 and ALAD1-2/2-2: blood lead level (BLL), tibia or trabecular lead level, zinc protoporphyrin (ZPP), hemoglobin, serum creatinine, blood urea nitrogen (BUN), dimercaptosuccinic acid–chelatable lead, or blood pressure. DATA EXTRACTION: Sample sizes, means, and standard deviations were extracted for the genotype groups. DATA SYNTHESIS: There was a statistically significant association between ALAD2 carriers and higher BLL in lead-exposed workers (weighted mean differences of 1.93 ÎŒg/dL). There was no association with ALAD carrier status among environmentally exposed adults with BLLs < 10 ÎŒg/dL. ALAD2 carriers were potentially protected against adverse hemapoietic effects (ZPP and hemoglobin levels), perhaps because of decreased lead bioavailability to heme pathway enzymes. CONCLUSION: Carriers of the ALAD2 allele had higher BLLs than those who were ALAD1 homozygous and higher hemoglobin and lower ZPP, and the latter seems to be inversely related to BLL. Effects on other organs were not well delineated, partly because of the small number of subjects studied and potential modifications caused by other proteins in target tissues or by other polymorphic genes

    Prevention of falls and fractures in old people by administration of calcium and vitamin d. randomized clinical trial

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    <p>Abstract</p> <p>Background</p> <p>There are many studies that associate vitamin D serum levels in older persons with muscle strength, physical performance and risk of fractures and falls. However, current evidence is insufficient to make a general recommendation for administrating calcium and vitamin D to older persons. The objective of this study is to determine the effectiveness of calcium and vitamin D supplementation in improving musculoskeletal function and decreasing the number of falls in person aged over 65 years.</p> <p>Methods/Design</p> <p>Phase III, randomized, double blind, placebo-controlled trial to evaluate the efficacy of already marketed drugs in a new indication. It will be performed at Primary Care doctor visits at several Healthcare Centers in different Spanish Health Areas. A total of 704 non-institutionalized subjects aged 65 years or older will be studied (sample size calculated for a statistical power of 80%, alpha error 0.05, annual incidence of falls 30% and expected reduction of 30% to 20% and expected loss to follow up of 20%). The test drug containing 800 IU of vitamin D and 1000 mg of calcium will be administered daily. The control group will receive a placebo. The subjects will be followed up over two years. The primary variable will be the incidence of spontaneous falls. The secondary variables will include: consequences of the falls (fractures, need for hospitalization), change in calcidiol plasma levels and other analytical determinations (transaminases, PTH, calcium/phosphorous, albumin, creatinine, etc.), change in bone mass by densitometry, change in muscle strength in the dominant hand and change in musculoskeletal strength, risk factors for falls, treatment compliance, adverse effects and socio-demographic data.</p> <p>Discussion</p> <p>The following principles have been considered in the development of this Project: the product data are sufficient to ensure that the risks assumed by the study participants are acceptable, the study objectives will probably provide further knowledge on the problem studied and the available information justifies the performance of the study and its possible risk for the participants.</p> <p>If calcium and vitamin D supplementation is effective in the prevention of falls and fractures in the elderly population, a recommendation may be issued with the aim of preventing some of the consequences of falls that affect quality of life and the ensuing personal, health and social costs.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01452243">NCT01452243</a></p> <p>Clinical trial authorized by the Spanish Medicines Agency: EudraCT number 2006-001643-63.</p

    Novel role for the innate immune receptor toll-like receptor 4 (TLR4) in the regulation of the wnt signaling pathway and photoreceptor apoptosis

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    Recent evidence has implicated innate immunity in regulating neuronal survival in the brain during stroke and other neurodegenerations. Photoreceptors are specialized light-detecting neurons in the retina that are essential for vision. In this study, we investigated the role of the innate immunity receptor TLR4 in photoreceptors. TLR4 activation by lipopolysaccharide (LPS) significantly reduced the survival of cultured mouse photoreceptors exposed to oxidative stress. With respect to mechanism, TLR4 suppressed Wnt signaling, decreased phosphorylation and activation of the Wnt receptor LRP6, and blocked the protective effect of the Wnt3a ligand. Paradoxically, TLR4 activation prior to oxidative injury protected photoreceptors, in a phenomenon known as preconditioning. Expression of TNFα and its receptors TNFR1 and TNFR2 decreased during preconditioning, and preconditioning was mimicked by TNFα antagonists, but was independent of Wnt signaling. Therefore, TLR4 is a novel regulator of photoreceptor survival that acts through the Wnt and TNFα pathways. © 2012 Yi et al

    Wet Granular Materials

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    Most studies on granular physics have focused on dry granular media, with no liquids between the grains. However, in geology and many real world applications (e.g., food processing, pharmaceuticals, ceramics, civil engineering, constructions, and many industrial applications), liquid is present between the grains. This produces inter-grain cohesion and drastically modifies the mechanical properties of the granular media (e.g., the surface angle can be larger than 90 degrees). Here we present a review of the mechanical properties of wet granular media, with particular emphasis on the effect of cohesion. We also list several open problems that might motivate future studies in this exciting but mostly unexplored field.Comment: review article, accepted for publication in Advances in Physics; tex-style change

    The deuteron: structure and form factors

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    A brief review of the history of the discovery of the deuteron in provided. The current status of both experiment and theory for the elastic electron scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic
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