3,352 research outputs found
Threshold concepts and metalearning capacity
This study operationalises the empowering concept of metalearning in the specific context of engagement with a threshold concept. An experience of metalearning was constituted in two parts. First students' awareness of themselves as learners is prompted by, and focuses on, a learning profile that is generated online through the completion of the Reflections on Learning Inventory (RoLI). Second, students are given an opportunity to interpret their respective profiles and write a short and undirected reflective account of their interpretation. The second part of the experience focuses not only on students' awareness but also on their capacity to control their future learning on the basis of their heightened awareness.
The Karyotype of the Yellow Dung Fly, Scathophaga stercoraria, a Model Organism in Studies of Sexual Selection
Knowledge of karyotypical characteristics of a species is essential for understanding how sexually selected and sexually antagonistic traits evolve. The yellow dung fly Scathophaga stercoraria L. (Diptera: Scathophagidae) is an established model system for studies of sexual selection and sexual conflict, but karyotypical data are lacking to date. Here, the karyotype of S. stercoraria was characterized using conventional Giemsa-staining and C-banding techniques. The diploid chromosome set consists of 6 pairs of bi-armed meta- or submetacentric chromosomes. The sex chromosomes are the largest chromosomes and constitute 30% of the total length of the diploid set in females and about 25% in males. Males are the heterogametic sex, and the length of the Y chromosome is about three-quarters of that of the X chromosome. C-banding revealed that both sex chromosomes are largely heterochromatic. In contrast, in the five autosome pairs, heterochromatin is limited to narrow bands in the centromeric regions. This karyotypic information will help provide a more profound understanding of the inheritance of phenotypic variation in reproductive traits and the chromosomal locations of underlying genes
Reliability and Validity of Self-Reported Questionnaires Related to Adolescent Violence and Consequences, Thailand
Copyright © 2013 Wongtonkam et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.In Thailand physical violence among male adolescents is considered a significant public health issue, although there has been little published research into the aetiology and functions of violence in Thai youth. Research in this area has been hampered by a lack of psychometrically sound tools that have been validated to assess problem behaviours in Asian youth. The purpose of this paper is to provide validity and reliability data on an instrument to measure violence in Thai youth. In this study, reliability and validity data for a sample of adolescent Thai youth are reported for the Communities That Care Youth Survey (CTC-YS), a measure of risk and protective factors for violent behaviour, and the STAXI-II, a measure of angry experience and expression. The findings showed overall high internal consistency for both questionnaires, and there was evidence of construct validity. It is concluded that these measures are appropriate for use in research that seeks to investigate youth violence among adolescents in Thailand
Simulations of the infrared, Raman, and 2D-IR photon echo spectra of water in nanoscale silica pores
Vibrational spectroscopy is frequently used to characterize nanoconfined liquids and probe the effect of the confining framework on the liquid structure and dynamics relative to the corresponding bulk fluid. However, it is still unclear what molecular-level information can be obtained from such measurements. In this paper, we address this question by using molecular dynamics (MD) simulations to reproduce the linear infrared (IR), Raman, and two-dimensional IR (2D-IR) photon echo spectra for water confined within hydrophilic (hydroxyl-terminated) silica mesopores. To simplify the spectra the OH stretching region of isotopically dilute HOD in D2O is considered. An empirical mapping approach is used to obtain the OH vibrational frequencies, transition dipoles, and transition polarizabilities from the MD simulations. The simulated linear IR and Raman spectra are in good general agreement with measured spectra of water in mesoporous silica reported in the literature. The key effect of confinement on the water spectrum is a vibrational blueshift for OH groups that are closest to the pore interface. The blueshift can be attributed to the weaker hydrogen bonds (H-bonds) formed between the OH groups and silica oxygen acceptors. Non-Condon effects greatly diminish the contribution of these OH moieties to the linear IR spectrum, but these weaker H-bonds are readily apparent in the Raman spectrum. The 2D-IR spectra have not yet been measured and thus the present results represent a prediction. The simulated spectra indicates that it should be possible to probe the slower spectral diffusion of confined water compared to the bulk liquid by analysis of the 2D-IR spectra
The importance of resilience to primary care practitioners: an interactive psycho-social model
In this paper, it is argued that an understanding of the factors that make up resilience can
enhance communication and concordance between practitioner and patient. A model is
presented demonstrating that resilience is an interaction between factors in the internal
domain, comprising psychological characteristics and resources, and the external domain,
comprising the social environment surrounding the individual. As resilience manifests itself
in different ways across the life-cycle, and according to individual circumstances, time is also
an important part of the model presented in this paper. Understanding this model of resilience
can lead to an insight that there are factors that can be influenced whereby the primary care
practitioner can treat the patient, or refer them after a process of concordance through a
deeper understanding of the factors that surround a patient’s current health status. Underlying
the model is the view that resilience is linked to the assets model of health, seeking to
promote and maintain health and prevent illness. Therefore, primary care practitioners,
through a deeper understanding of the circumstances of the patient, and through
understanding the factors that promote resilience, may be better able to take action in health
promotion and maintenance
Measurement of Intracellular Fluorescence of Human Monocytes Relative to Oxidative Metabolism
Human monocytes (MN) produce O2â and H2O2 when stimulated by agonists. Dichlorofluorescin diacetate (DCFHâ DA) has been used as a substrate for measuring intracellular oxidant production in neutrophils. DCFHâ DA is hydrolyzed by esterases to dichlorofluorescin (DCFH), which is trapped within the cell. This nonfluorescent molecule is then oxidized to fluorescent dichlorofluorescin (DCF) by action of cellular oxidants. DCFHâ DA can not be appreciably oxidized to a fluorescent state without prior hydrolysis. We have examined the utility of DCFHâ DA for the assessment of monocyte oxidative responses. The levels of intracellular fluorescence measured by flow cytometry were considerably less than expected from reported levels of O2â â production or chemiluminescence assays. Compared with neutrophils, monocytes produced minimal increases in DCF fluorescence after stimulation with phorbol myristate acetate as measured by flow cytometry, but both cell types showed increases in fluorescence when bulk cell suspensions were measured by spectrofluorometry. To determine the intracellular location of the DCFH, bulk fluorescence measurements were made on both whole and sonicated cell preparations. When intact mononuclear cells were preloaded with DCFHâ DA, then sonicated and oxidized with added excess H2O2, the increase in fluorescence was only 30% of the fluorescence of mononuclear cell sonicates to which DCFHâ DA was added and oxidized in a similar manner. These results suggest that a portion of the DCFHâ DA incorporated by intact cells, is not susceptible to oxidation by the added H2O2. Addition of NaOH to induce hydrolysis of any residual DCFHâ DA in the sonicates of DCFHâ DAâ loaded intact mononuclear cells resulted in a further increase in fluorescence upon addition of H2O2, suggesting that a significant portion of the DCFHâ DA was not hydrolyzed despite ample uptake of this dye by these cells. In contrast, no further increase in fluorescence was observed in sonicates of DCFHâ DAâ loaded intact neutrophils, suggesting complete hydrolysis of all incorporated DCFHâ DA to DCFH. When monocytes were allowed to phagocytose DCFHâ DAâ loaded Staphylococcus aureus, intracellular fluorescence was measurable by flow cytometry, indicating intracellular oxidation of the fluorochromes. We therefore propose that in monocytes the mechanism of intracellular processing of these fluorochromes differs from that in neutrophils owing to differences in intracellular localization of fluorochromes, site of oxidant production, and/or accessibility of the DCFHâ DA to esterolysis.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141433/1/jlb0304.pd
Is resilience relevant to smoking abstinence for Indigenous Australians?
This article is under embargo for 12 months from the date of publication, in accordance with the publisher's policy. This is a pre-copyedited, author-produced PDF of an article accepted for publication in HEALTH PROMOTION INTERNATIONAL following peer review. The version of record [Tsourtos G, Ward P, Lawn S, Winefield A, Hersh D and Coveney J (2014) Is resilience relevant to smoking abstinence for Indigenous Australians? . Health Promotion International 30 (1): pp. 64-76] is available online at: http://heapro.oxfordjournals.org/content/30/1/64The prevalence rate of tobacco smoking remains high for Australian Indigenous people despite declining rates in other Australian populations. Given many Indigenous Australians continue to experience a range of social and economic structural problems, stress could be a significant contributing factor to preventing smoking abstinence. The reasons why some Indigenous people have remained resilient to stressful adverse conditions, and not rely on smoking to cope as a consequence, may provide important insights and lessons for health promotion policy and practice. In-depth interviews were employed to collect oral histories from 31 Indigenous adults who live in metropolitan Adelaide. Participants were recruited according to smoking status (non-smokers were compared to current smokers to gain a greater depth of understanding of how some participants have abstained from smoking). Perceived levels of stress were associated with encouraging smoking behaviour. Many participants reported having different stresses compared to non-Indigenous Australians, with some participants reporting having additional stressors such as constantly experiencing racism. Resilience often occurred when participants reported drawing upon internal psychological assets such as being motivated to quit and where external social support was available. These findings are discussed in relation to a recently developed psycho-social interactive model of resilience, and how this resilience model can be improved regarding the historical and cultural context of Indigenous Australians’ experience of smoking
Waterpipe smoking in students: Prevalence, risk factors, symptoms of addiction, and smoke intake. Evidence from one British university
Background: Anecdotal reports suggest waterpipe smoking is becoming common in students in western countries. The aim was to examine prevalence, risk factors, symptoms of addiction, and smoke intake.
Methods: This was a cross-sectional survey of students with subsidiary survey of regular waterpipe user and survey of exhaled carbon monoxide (CO) before and after waterpipe smoking in customers of a waterpipe café. 937 students of Birmingham University completed the initial survey with a follow up of 21 regular waterpipe smokers. 63 customers of a waterpipe café near the University completed the study of CO intake.
Results: 355 (37.9%, 95% confidence intervals (CI) 34.8 to 41.1%) students had tried waterpipes,the prevalence of trying rising with duration at University. 75 (8.0%, 95%CI 6.4 to 10.0%) were regular smokers, similar to the prevalence of cigarette smoking (9.4%). Although cigarette smoking was the major risk factor for being a regular waterpipe smoker, odds ratio (95%CI) 2.77 (1.52 to 5.06), 65% of waterpipe smokers did not smoke cigarettes. Seven of 21 (33.3%) regular waterpipe smokers experienced cravings. Nearly all regular waterpipe users thought it less harmful than smoking cigarettes. The mean (standard deviation) rise in CO was 37.4 (25.8)ppm, nearly twice as high as a typical cigarette smoker seeking cessation treatment.
Conclusion: Waterpipe smoking is a common part of student culture in one British university, as in the Middle East and in the United States. It poses a potential threat to public health, with evidence of dependence and high smoke intake
A Hierarchical Method for Removal of Baseline Drift from Biomedical Signals: Application in ECG Analysis
Noise can compromise the extraction of some fundamental and important features from biomedical signals and hence prohibit accurate analysis of these signals. Baseline wander in electrocardiogram (ECG) signals is one such example, which can be caused by factors such as respiration, variations in electrode impedance, and excessive body movements. Unless baseline wander is effectively removed, the accuracy of any feature extracted from the ECG, such as timing and duration of the ST-segment, is compromised. This paper approaches this filtering task from a novel standpoint by assuming that the ECG baseline wander comes from an independent and unknown source. The technique utilizes a hierarchical method including a blind source separation (BSS) step, in particular independent component analysis, to eliminate the effect of the baseline wander. We examine the specifics of the components causing the baseline wander and the factors that affect the separation process. Experimental results reveal the superiority of the proposed algorithm in removing the baseline wander
Greater priming for previously distracting information in young than older adults when suppression is ruled out
The use of previously distracting information on memory tests with indirect instructions is usually age-equivalent, while young adults typically show greater explicit memory for such information. This could reflect qualitatively distinct initial processing (encoding) of distracting information by younger and older adults, but could also be caused by greater suppression of such information by younger adults on tasks with indirect instructions. In Experiment 1, young and older adults read stories containing distracting words, which they ignored, before studying a list of words containing previously distracting items for a free recall task. Half the participants were informed of the presence of previously distracting items in the study list prior to recall (direct instruction), and half were not (indirect instruction). Recall of previously distracting words was age-equivalent in the indirect condition, but young adults recalled more distracting words in the direct condition. In Experiment 2, participants performed the continuous identification with recognition task, which captures a measure of perceptual priming and recognition on each trial, and is immune to suppression. Priming and recognition of previously distracting words was greater in younger than older adults, suggesting that the young engage in more successful suppression of previously distracting information on tasks in which its relevance is not overtly signaled
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