21 research outputs found

    Do the stimulant medications improve neuropsychological performance of college students with ADHD?

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    Attention Deficit/Hyperactivity Disorder (ADHD) is a prevalent disorder estimated to affect 5% to 10% of school-aged children and approximately 4% of adults worldwide. The defining symptoms are hyperactivity, impulsivity and inattention, which are all acutely reduced by the stimulant medications, methylphenidate and amphetamine. Nevertheless, in spite of robust short-term efficacy, long-term follow-up studies fail to show drug effects on academic achievement of ADHD students. Because recent research indicates that the medications also do not normalize performance of ADHD patients on some neuropsychological tests, we thought this might shed some light on the causes of ADHD students’ academic underachievement. There is a consistent body of evidence showing that adults with ADHD are impaired on neuropsychological tests of vigilance, verbal memory/fluency, response interference, and planning ability. In our study we used 4 neuropsychological tests: d2 Test, Control Oral Word Association Test, Stroop Tests, and Tower of London Test to test vigilance, verbal fluency, response interference, and planning ability respectively. We found that undergraduate students with ADHD did not show significant deficits except in Stroop interference, compared to normal controls. ADHD medications improved Stroop interference in ADHD students; however, medications did not help ADHD students perform better than normal students in domains of functions where no deficits were found

    Intellectual Disability in Children with Congenital Heart Defects in Western Australia

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    Introduction Congenital heart defects (CHD) are diagnosed up to age 6 in 8-12/1,000 births annually in Western Australia. Recent improvements in management of infants with CHDs has significantly increased survival; approximately 85\% of infants with CHDs live beyond childhood. However, children with CHDs may have increased risk of life-long intellectual disabilities. Objectives and Approach We conducted a study of 20,997 children to determine risk of intellectual disability (ID). All singleton, live born infants with CHDs born 1983-2010 were identified from the Western Australian Register for Developmental Anomalies, a statewide birth defects registry (n=6,968). Infants without CHDs born 1983-2010 were randomly selected from birth records (n=14,029). All data were linked to the Western Australia Midwives Notification System to obtain maternal and infant information. Children with ID were identified by linkage to the statewide Intellectual Disability Exploring Answers database. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from multivariable logistic regression analyses. Results Of 20,997 children, 965 (4.6%) had an ID; 1.3% of children without CHDs and 11.2% of children with CHDs had an ID (P<0.001). 0.2% of children without CHDs and 0.4% of children with CHDs had autism. Three percent of children with CHDs had a known biomedical cause for ID (excluding trisomy 21) and 4.4% of children with CHDs had trisomy 21. Children with CHDs had 9 times the risk of ID compared to children without CHDs (RR=9.30; 95% CI: 7.91, 10.94). Children with CHDs almost had a twofold increased risk of autism compared to children without CHDs (RR=1.78; 95% CI: 1.07, 2.95). The greatest risk of ID among children with CHDs was associated with trisomy 21 (RR=166.0; 95% CI: 78.5, 350.8). Conclusion/Implications Children with CHDs have higher risk of ID than children without CHDs. Although the greatest risk for ID was for trisomy 21, children with CHDs still had increased risk of ID from other causes and all causes overall. Future research should elucidate the underlying etiology of ID in these children

    MicroRNAs Modulate Pathogenesis Resulting from Chlamydial Infection in Mice

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    Not all women infected with chlamydiae develop upper genital tract disease, but the reason(s) for this remains undefined. Host genetics and hormonal changes associated with the menstrual cycle are possible explanations for variable infection outcomes. It is also possible that disease severity depends on the virulence of the chlamydial inoculum. It is likely that the inoculum contains multiple genetic variants, differing in virulence. If the virulent variants dominate, then the individual is more likely to develop severe disease. Based on our previous studies, we hypothesized that the relative degree of virulence of a chlamydial population dictates the microRNA (miRNA) expression profile of the host, which, in turn, through regulation of the host inflammatory response, determines disease severity. Thus, we infected C57BL/6 mice with two populations of Chlamydia muridarum, each comprised of multiple genetic variants and differing in virulence: an attenuated strain (NiggA) and a virulent strain (NiggV). NiggA and NiggV elicited upper tract pathology in 54% and 91% of mice, respectively. miRNA expression analysis in NiggV-infected mice showed significant downregulation of miRNAs involved in dampening fibrosis (miR-200b, miR-200b-5p, and 200b-3p miR-200a-3p) and in transcriptional regulation of cytokine responses (miR-148a-3p, miR-152-3p, miR-132, and miR-212) and upregulation of profibrotic miRNAs (miR-142, and miR-147). Downregulated miRNAs were associated with increased expression of interleukin 8 (IL-8), CXCL2, IL-1ÎČ, tumor necrosis factor alpha (TNF-α), and IL-6. Infection with NiggV but not NiggA led to decreased expression of Dicer and Ago 2, suggesting that NiggV interaction with host cells inhibits expression of the miRNA biogenesis machinery, leading to increased cytokine expression and pathology

    Study of an Arctic blowing snow-induced bromine explosion event in Ny-Ålesund, Svalbard

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    Bromine explosion events (BEEs) are important processes that influence the atmospheric oxidation capacity, especially in the polar troposphere during spring. Although sea ice surface is thought to be a significant bromine source, bromine release mechanisms remain unclear. High-resolution ground-based observations of reactive bromine, such as BrO, are important for assessing the potential impacts on tropospheric ozone and evaluating chemical models. However, previous model studies paid little attention to Svalbard, which is surrounded by both open ocean and sea ice. In this paper, we present continuous BrO slant column densities and vertical column densities derived by Multi-Axis Differential Optical Absorption Spectroscopy deployed at Ny-Ålesund (78.92°N, 11.93°E) in March 2017. We focused on one BEE in mid-March, during which the vertical column densities of BrO surged from 4.26 × 1013 molecular cm−2 to the peak at 1.23 × 1014 molecular cm−2 on March 17, surface ozone depleted from a background level of 46.25 parts per billion by volume (ppbv) to 13.9 ppbv. This case study indicates that the BEE was strongly associated with blowing snow induced by the cyclone systems that approached Svalbard from March 14 to 18. By considering meteorological conditions, sea ice coverage, and airmass trajectory history, we demonstrate that sea salt aerosols (SSAs) from blowing snow on sea ice, rather than from open ocean, are attributed to the occurrence of this BEE. Model results from a parallelized-tropospheric offline model of chemistry and transport (p-TOMCAT) indicate that this BEE was mainly triggered by a blowing snow event associated with a low-pressure cyclone system. The concentration of blowing-snow-sourced SSAs surged to peak when the airmass pass across the sea-ice-covered area under high wind speed, which is a critical factor in the process of bromine explosion observed in Ny-Ålesund. Due to the coarse resolution, the possible delayed timing of bromine release from SSA and the model-data discrepancies still exist

    Effects of Allergen Sensitization on Response to Therapy in Children with Eosinophilic Esophagitis

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    Background: In children with eosinophilic esophagitis (EoE) foods are the most common disease triggers, but environmental allergens are also suspected culprits. Objective: To determine the effects of environmental allergen sensitization on response to treatment in children with EoE in the southeastern United States. Methods: Patients 2 to 18 years old who were referred to the Arkansas Children’s Hospital Eosinophilic Gastrointestinal Disorders Clinic from January 2012 to January 2016 were enrolled in a prospective, longitudinal cohort study with collection of demographics, clinical symptoms, medical history, allergy sensitization profiles, and response to treatment over time. Comparisons were made between complete responders (peak esophageal eosinophil count \u3c 15 per high-power field [HPF]) and nonresponders (\u3e 25 eosinophils per HPF) after treatment with diet elimination alone, swallowed corticosteroids alone, or diet elimination and swallowed corticosteroids. Sensitization patterns to environmental allergens found in the southeastern United States were analyzed for the effect on treatment response. Results: A total of 223 individuals were enrolled. Of these, 182 had environmental allergy profiling and at least one endoscopy while receiving proton pump inhibitor (PPI) therapy. Twenty-nine individuals had PPI-responsive EoE and were excluded from further analysis, leaving 123 individuals with none-PPI-responsive EoE who were further analyzed; 72 (58.5%) were complete responders and 33 (26.8%) were nonresponders. Seventeen individuals (13.8%) were partial responders (≄ 1 but ≀ 25 eosinophils per HPF) and excluded from further analysis. Nonresponders were more likely to be sensitized to perennial allergens (P = .02). There was no significant difference in response based on seasonal allergen sensitization. Individuals with mold or cockroach sensitization were more likely to fail combination diet and swallowed corticosteroid treatment (P = .02 and P = .002). Conclusion: Perennial allergen and mold sensitization may lead to nonresponse to EoE treatment in some patients. Additional studies are needed to further understand the effect of environmental allergens on EoE

    Predicting Academic Performance: A Systematic Literature Review

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    The ability to predict student performance in a course or program creates opportunities to improve educational outcomes. With effective performance prediction approaches, instructors can allocate resources and instruction more accurately. Research in this area seeks to identify features that can be used to make predictions, to identify algorithms that can improve predictions, and to quantify aspects of student performance. Moreover, research in predicting student performance seeks to determine interrelated features and to identify the underlying reasons why certain features work better than others. This working group report presents a systematic literature review of work in the area of predicting student performance. Our analysis shows a clearly increasing amount of research in this area, as well as an increasing variety of techniques used. At the same time, the review uncovered a number of issues with research quality that drives a need for the community to provide more detailed reporting of methods and results and to increase efforts to validate and replicate work.Peer reviewe

    Ambient Temperature Flotation of Sedimentary Phosphate Ore Using Cottonseed Oil as a Collector

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    The mid-low grade sedimentary phosphate ore, abundant in silicate and carbonate gangue minerals, exhibits a poor processability. It is conventionally enriched using high temperature flotation to remove silicate gangues with fatty acid as a collector. Cottonseed oil has been proved to be an efficient collector for achieving ambient temperature flotation of the sedimentary phosphate ore used in this study. Flotation kinetics was investigated to ascertain the excellent collecting performance of cottonseed oil, as compared with oleic acid, and the phosphate flotation fitted well with the first-order flotation model. Based on the analysis of flotation reagent effect on the direct flotation process using the response surface methodology (RSM), a closed circuit of direct-reverse flotation for stepwise removing silicate and carbonate gangues from the sedimentary phosphate ore was established. Consequently, a required high quality of phosphate concentrate containing 30.16% P2O5 was obtained, with a recovery of 90.90%. Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) of the flotation products confirmed that the majority of silicate and carbonate gangues were effectively removed from the concentrate products

    Effects of Metal Ions on the Flotation of Apatite, Dolomite and Quartz

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    The effects of Ca2+, Mg2+, Al3+, and Fe3+ on the flotation behaviors of apatite, dolomite and quartz were investigated through a micro-flotation test, and the influence of calcium ions on the flotation of these minerals was further elucidated by solution chemistry study, zeta potential measurement, and X-ray photoelectron spectroscopy (XPS) analyses. The results indicate that an appropriate amount of Ca2+ and Mg2+ can improve the floatability of apatite but had a negligible effect on the flotation performance of dolomite, whereas Al3+, Fe3+, and excessive amounts of Ca2+ decreased the recovery of apatite and dolomite. The studied metal cations can activate quartz at a particular pH. It can be inferred from solution chemistry and zeta potential measurement that the influence of metal ions on the flotation of different minerals should be attributed to the adsorption of various hydrolysis species on the mineral surfaces. XPS analyses reveal that calcium ions can enhance the adsorption of anionic collector on apatite and quartz surfaces, and there are no apparent changes to be observed on the surface of dolomite in the absence and presence of calcium ions at a concentration of 2.5 × 10−3 M, which was in good agreement with the micro-flotation results

    Synthesis of the ICESat/ICESat-2 and CryoSat-2 observations to reconstruct time series of lake level

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    Synthesis of multi-satellite altimetry facilitates the acquisition of long-term changes in lake level but may induce biases due to inconsistent data sources, and thus remains largely unexplored. This study investigates the integrated application of Ice, Cloud, and land Elevation Satellite (ICESat), ICESat-2, and CryoSat-2 missions to provide consecutive lake level series in 2003–2020. The sample comprises 48 lakes in the world with gauge-based or Hydroweb water level data. The CryoSat-2 data are first adjusted to the ICESat-2 height reference based on the mean values of their monthly water level difference during their overlapping period (2018–2020). Then, the corrected CryoSat-2 data are used to link the ICESat and ICESat-2 data. Results show that in the sample lakes, the deviations between CryoSat-2 and ICESat-2 data vary and range from −0.78 m to 0.13 m. The data quality of the synthesized time series is evaluated by comparing against the validation data, with an average R2 of 0.84. This study shows that CryoSat-2 has the potential of filling the gap between ICESat and ICESat-2. The three altimeters can be expected to integrate effectively for monitoring lake water level changes in the past two decades
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