993 research outputs found

    Integrating Item Accuracy and Reaction Time to Improve the Measurement of Inhibitory Control Abilities in Early Childhood

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    Efforts to improve children’s executive function are often hampered by the lack of measures that are optimized for use during the transition from preschool to elementary school. Whereas preschool-based measures often emphasize response accuracy, elementary school-based measures emphasize reaction time (RT)—especially for measures inhibitory control (IC) tasks that typically have a speeded component. The primary objective of this study was to test in a preschool-aged sample whether the joint use of item-level accuracy and RT data resulted in improved scoring for three IC tasks relative to scores derived from accuracy data alone. Generally, the joint use of item-level accuracy and RT data resulted in modest improvements in the measurement precision of IC abilities. Moreover, the joint use of item-level accuracy and RT helped eliminate floor and ceiling effects that occurred when accuracy data were considered alone. Results are discussed with respect to the importance of scoring IC tasks in ways that are maximally informative for program evaluation and longitudinal modeling

    The Benefits of Adding a Brief Measure of Simple Reaction Time to The Assessment of Executive Function Skills in Early Childhood

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    Early childhood represents a period of rapid cognitive developmental change in executive function (EF) skills along with a variety of related cognitive processes, including processing speed. This leads to interpretational challenges in that children’s performance on EF tasks reflects more than EF skills per se. We tested whether the inclusion of a brief measure of simple reaction time (SRT) during EF assessments could help to partially address this challenge. Data were drawn from a cross-sectional convenience sample of 830 preschool-aged children. Individual differences in SRT were significantly associated with performance on all tasks (R2s = .09–.26); slower performance on the SRT task was associated with poorer performance on each EF task. Age-related differences in individual EF tasks were reduced by approximately one half after accounting for age-related differences in SRT, and EF task scores were less coherent (i.e., less strongly intercorrelated with each other) after the removal of SRT. Age-related differences in EF were smaller (Cohen ds = 1.36 vs. 0.78), and poverty-related differences in EF were larger (Cohen ds = 0.30 vs. 0.46) after accounting for SRT-related variation. Finally, consistent with previous studies, SRT-related differences in fluid reasoning were mediated by EF skills. Results are discussed with respect to using a brief measure of SRT to partially address the problem of measurement impurity at the level of individual EF tasks

    Characterization of culture-positive adenovirus serotypes from respiratory specimens in Toronto, Ontario, Canada: September 2007–June 2008

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    This study describes the prevalence of culture-positive adenovirus serotypes in culture-positive respiratory specimens sent to the Central Public Health Laboratory, Toronto, Ontario, Canada for the period September 2007–June 2008. Total nucleic acid was extracted from virus cultures using an automated extraction method followed by polymerase chain reaction and Sanger sequencing of the adenovirus hexon gene hypervariable region 7. 73% of specimens (n = 70) were from patients ≤ 4 years of age. Of the 96 adenovirus isolates, the most common identified serotypes were serotype 3 (n = 44, 46%), serotype 2 (n = 25, 26%), serotype 1 (n = 17, 18%), and serotype 21 (n = 5, 5%). Adenovirus serotype 14 was not found in this study group. The leading serotype, Ad3, was identified throughout the duration of the study period. Molecular methods allow for the determination of circulating adenovirus serotypes and be used to document the spread of highly virulent adenoviral serotypes into a region

    How to Measure Export via Bacterial Multidrug Resistance Efflux Pumps

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    Bacterial multidrug resistance (MDR) efflux pumps are an important mechanism of antibiotic resistance and are required for many pathogens to cause infection. They are also being harnessed to improve microbial biotechnological processes, including biofuel production. Therefore, scientists of many specialties must be able to accurately measure efflux activity. However, myriad methodologies have been described and the most appropriate method is not always clear. Within the scientific literature, many methods are misused or data arising are misinterpreted. The methods for measuring efflux activity can be split into two groups, (i) those that directly measure efflux and (ii) those that measure the intracellular accumulation of a substrate, which is then used to infer efflux activity. Here, we review the methods for measuring efflux and explore the most recent advances in this field, including single-cell or cell-free technologies and mass spectrometry, that are being used to provide more detailed information about efflux pump activity

    Development of Single-station Early Warning Lightning Alarm System

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    Lightning is one of the spectacular natural phenomena which happen on the earth. More than 2000 people are killed worldwide by lightning each year. The lightning monitoring system is important as the early warning alarm system. In this paper,lightning warning alarm system which can monitor and observe the lightning activity has been discussed. The system able to trigger the warning alarm whenever a lightning strikes at a particular area in 10 km radius from UMP Pekan, Pahang, Malaysia. The LabVIEW software was used as a data logger to measure, analyze and calculate the lightning distance. The accuracy of the system has been compared and validated by the Pekan Lightning Detection System (PLDS)

    Exploiting the Diversity of the Heat-Shock Protein Family for Primary and Secondary Tauopathy Therapeutics

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    The heat shock protein (Hsp) family is an evolutionarily conserved system that is charged with preventing unfolded or misfolded proteins in the cell from aggregating. In Alzheimer’s disease, extracellular accumulation of the amyloid β peptide (Aβ) and intracellular aggregation of the microtubule associated protein tau may result from mechanisms involving chaperone proteins like the Hsps. Due to the ability of Hsps to regulate aberrantly accumulating proteins like Aβ and tau, therapeutic strategies are emerging that target this family of chaperones to modulate their pathobiology. This article focuses on the use of Hsp-based therapeutics for treating primary and secondary tauopathies like Alzheimer’s disease. It will particularly focus on the pharmacological targeting of the Hsp70/90 system and the value of manipulating Hsp27 for treating Alzheimer’s disease

    A Comparison of Three Executive Function Batteries in a Preschool-Aged Sample

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    There is great interest in the development of executive function (EF) in the preschool period. Accordingly, multiple performance-based measures of EF have been developed for this age group, yet little is known about how they compare to one another. This study used a large and diverse sample of 3-to-5-year-old children (N = 846), who completed subtests of the National Institutes of Health’s Toolbox Cognition Battery (NTCB), the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV), and the EF Touch battery. Scores across the three batteries were compared and associations with age, income, and race/ethnicity were examined. Results revealed that (1) the three tasks were moderately correlated (r = 0.44–0.51, all p < 0.001), but children had higher mean accuracy scores on EF Touch than on the NTCB or the WPPSI-IV. (2) Mean accuracy scores on all batteries were linearly associated with child age (all F > 32.68, all p < 0.0001). (3) Comparisons by income and race/ethnicity showed lower accuracy for low-income children on the WPPSI-IV and lower accuracy for White children on the NTCB. Across all batteries, there was consistently lower accuracy for Hispanic children. In conclusion, the three batteries we examined performed similarly across several metrics. EF Touch may be more appropriate for younger children, while the NTCB performed well with older children

    Catalysis of proline isomerization and molecular chaperone activity in a tug-of-war

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    Catalysis of cis/trans isomerization of prolines is important for the activity and misfolding of intrinsically disordered proteins. Catalysis is achieved by peptidylprolyl isomerases, a superfamily of molecular chaperones. Here, we provide atomic insight into a tug-of-war between cis/trans isomerization and molecular chaperone activity. Catalysis of proline isomerization by cyclophilin A lowers the energy barrier for \u3b1-synuclein misfolding, while isomerase-binding to a separate, disease-associated protein region opposes aggregation. We further show that cis/trans isomerization outpowers the holding activity of cyclophilin A. Removal of the proline isomerization barrier through posttranslational truncation of \u3b1-synuclein reverses the action of the proline isomerase and turns it into a potent molecular chaperone that inhibits protein misfolding. The data reveal a conserved mechanism of dual functionality in cis/trans isomerases and define its molecular determinants acting on intrinsically disordered proteins

    Psychological well-being, cardiorespiratory fitness, and long-term survival

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    BACKGROUND: Psychological well-being is associated with mortality/survival. Although cardiorespiratory fitness (CRF) is one of the strongest predictors of mortality, studies examining the relationship between well-being and survival seldom account for the possible effects of CRF. PURPOSE: This study examined the independent associations of psychological well-being components (low level of negative emotion and high level of positive emotion) and CRF, as well as their combined effects, with survival. METHODS: Participants (N=4888) were examined in 1988-1997 and followed up for a median period of ∼15 years (212 deaths, 4.3%). CRF was assessed by a maximal exercise test on a treadmill. Low-level negative emotion was defined as the minimum score of the negative emotion subscale of the CES-D scale and high-level positive emotion as the maximum score of the positive emotion subscale. Results are presented as hazard ratios (95% CIs). Data were analyzed in 2009. RESULTS: After adjustment for a set of established risk factors, men and women with low levels of negative emotion had lower risk of death than those with higher levels of negative emotion, 0.66 (95% CI=0.50, 0.87). The association persisted after additional adjustment for CRF and positive emotion. High level of positive emotion was not associated with survival. A high level of CRF independently predicted lower risk of death, 0.54 (95% CI=0.37, 0.79), compared to a low level of CRF. The risk of death in participants with both a low level of negative emotion and a high level of CRF was 0.37 (95% CI=0.22, 0.63), compared to their peers with higher levels of negative emotion/low levels of CRF. CONCLUSIONS: Low levels of negative emotion and high levels of CRF are independent predictors of long-term survival in men and women. A strong combined effect was observed, as individuals with both a low level of negative emotion and a high level of CRF had a 63% lower risk of premature death than those with higher levels of negative emotion and a low level of CRF.This study was supported by NIH grants AG06945 and HL62508, and in part by an unrestricted research grant from The Coca-Cola Company. The study also was supported in part by Robert Wood Johnson Foundation's Pioneer Portfolio (grant number 63597); the Spanish Ministry of Education (EX-2008-0641, EX-2007-1124); the Swedish Council for Working Life and Social Research; and the Swedish Heart-Lung Foundation (20090635)
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