80 research outputs found
Comment on : 'multi-element signatures of stream sediments and sources under moderate to low flow conditions' by M.I. Stutter, S.J. Langan, D.G. Lumsdon, L.M. Clark
Get PDFIn a recent paper on ‘Multi-element signatures of stream sediments and sources under moderate to low flow conditions’, Stutter et al., 2009 M.I. Stutter, S.J. Langan, D.G. Lumsdon and L.M. Clark, Multi-element signatures of stream sediments and sources under moderate to low flow conditions, Appl. Geochem. 24 (2009), pp. 800–809. Article | PDF (392 K) | View Record in Scopus | Cited By in Scopus (2)Stutter et al. (2009) presented results of a simple sediment source tracing method based on major and trace elements for a small agricultural catchment in NE Scotland. The authors reported statistically significant, larger concentrations of four trace elements (Ce, Nd, Th and Y) in bank subsoils (n = 5) and stream bed sediments (n = 3) compared to topsoils from both pasture (n = 5) and arable (n = 5) land. They used these differences to aid discrimination between topsoil and subsoil (stream bank erosion) contributions to bed sediment. These elements may be more depleted in topsoil compared to subsoil because the former have been subject to more intense weathering over a longer period. If these naturally occurring trace elements could be used to understand the relative proportions of topsoil and subsoil contributions to headwater bed sediments this approach might be applied more widely to elucidate transport pathways for the transfer of agricultural contaminants such as particulate phosphorus to streams (Walling et al., 2008). This approach warrants further investigation across a range of catchments at different scales with contrasting land use and bedrock types. This can be undertaken using data from regional-scale geochemical surveys (Johnson et al., 2005) which include analyses of both stream bed sediments and subsoil samples. Previous studies have shown that much of lowland central England is at risk of topsoil transfer to watercourses via land drains (Chapman et al., 2003). A geochemical survey across part of central England covering 15 400 km2 was recently undertaken and these data are well-suited to testing whether three of the four trace elements identified by Stutter et al. (2009) might be used to discriminate between topsoil and subsoil in sediments more widely. Specifically, if the concentrations of these elements are significantly smaller in stream bed sediments than in the subsoil, this may be due to mixing with topsoils which have lower concentrations of these elements. Below the regional-scale survey, the methods the author used to compare the geochemical data in subsoil and bed sediments described, and the findings and their implications discussed
Self-efficacy in parents of young children who stutter
No full textParental self-efficacy (PSE) is defined as a parents perceptions of his/her ability to be confident and competent in the domain of parenting. The purpose of the current exploratory study was to examine the PSE of mothers of children who stutter (CWS; N = 13), and compare these perceptions with parents of children with speech sound disorders (N = 21) and with no disorder (N = 90). Results indicated significant relationships between the Parenting Sense of Competence Scale (PSOC) Total Score and treatment participation, and the PSOC Satisfaction subscale and treatment effectiveness among mothers of CWS. Findings suggest that having a CWS does not relate to poorer perceptions of parenting abilities. Results hold implications for future research and clinical implications on PSE in mothers of children who stutter
Students who stutter – How to support them at school
No full textWieloczynnikowa koncepcja jąkania zakłada indywidualną kombinację uzupełniających się czynników, które mogą stanowić przyczynę wystąpienia tego zaburzenia mowy u dziecka. Są to czynniki fizjologiczne, lingwistyczne, psychologiczne oraz środowiskowe. Koncentrując się na dwóch ostatnich, autor przedstawia fakty na temat jąkania oraz dokonuje opisu jego złożoności w kontekście terapeutycznym. Jąkający się uczeń wymaga bowiem wsparcia nie tylko ze strony logopedy i rodziców, ale również nauczycieli. W artykule opisane zostało funkcjonowanie jąkającego się ucznia w szkole. Ponadto autor na podstawie literatury przedmiotu prezentuje rady dla nauczycieli, które mogą wykorzystać w swojej pracy wychowawczo-dydaktycznej z dzieckiem, które się jąka.The multifactorial concept of stuttering assumes an individual combination of factors that complement each other and that may be the cause of this speech disorder in a child. They include physiological, linguistic, psychological, and community-based factors. Focusing on the latter two, the author presents facts about stuttering and describes its complexity within a herapeutic context. This is because students who stutter require support not only from speech therapists and their parents but also from their teachers. The article describes how students who stutter function at school. Also, based on the literature on the subject, the author presents advice for teachers they can use in their educational work with children who stutter
Effects of DNA copy number on short tandem repeat stutter ratios
No full textDetermining the weight of evidence against a suspect is best served by high fidelity signal representations of forensically relevant genomic regions of interest: Short tandem repeats (STR). During PCR, STR is a synthesized fragment one repeat unit shorter than wildtype. When electrophoresed and detected, the relative peak heights at the stutter and allele positions can be used as a proxy for the relative level of stutter to allele product generated during PCR, informing forensic DNA interpretation. Since many forensic samples contain only a few copies of DNA, this study explores if relative stutter abundances are of the same distributions when originating from high- and low- copy numbers. Data analysis began by categorizing the signals as noise, stutter, and allele. Only stutter and allelic peaks were retained for further analysis. Samples were amplified at 0.25 ng and 0.0313 ng; data from 5 STR loci were interrogated, resulting in analysis across 620 data points. The data was first explored through visual representation via boxplot.
Before proceeding to statistical analysis, a comprehensive literature review demonstrated that the stutter models solely relying on per-locus descriptions of stutter ratios (SRs) may be improved by considering the sequence of the STRs themselves. As such, all statistical evaluations were conducted on a per-allele basis. Next, a t-test (p-value threshold: 0.005) was employed to explore if average SRs between high- and low-copy numbers are similar. The results show significantly different mean values between the two templates. This has far-reaching forensic implications since it suggests that classical binary approaches to genotype inference for low-template samples ought not utilize boundaries developed from high-template ones.
Subsequently, we tested the SRs between low- and high- template samples by evaluating the similarity of the distributions themselves. To complete this test, a Kolmogorov-Smirnov test was performed. Mostly, the distributions were distinct, wherein low template samples demonstrated a higher proportion of stutter peaks exceeding expectation. These results are similar to the t-test results, therein suggesting a more refined approach to genotype inference is required for complex forensic signal containing both high- and low- template levels within a single mixture.M.S.Includes bibliographical reference
Relationships Between Psychosocial Factors and Quality of Life for Adults Who Stutter
No full textPurpose: In this study, the author examined the relationship of social support, empowerment, self-help support group participation, and group identification to quality of life in adults who stutter. Method: Two-hundred forty-nine adults who stutter completed a web-based survey, including measures of social support, empowerment, self-help support group participation, group identification, and quality of life. Results: After controlling for demographic and stuttering parameters, both empowerment in the self-esteem/ self-efficacy domain and social support from family significantly predicted quality of life in adults in the sample. Conclusions: Increased self-esteem/self-efficacy and social support from family relates to improved quality of life in adults who stutter, independent of stuttering severity. Treatments that increase feelings of self-esteem/self-efficacy and strengthen social support from the family should be considered for individuals who struggle to cope with stuttering in order to enhance their quality of life
A mathematical model of polymerase chain reaction induced stutter
No full textThesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (page 48).This is a thesis on understanding stutter present in capillary electropherogram readouts as this methodology forms the basis of current DNA fingerprinting. The readouts come from taking samples of various initial template masses of DNA from different individuals, applying polymerase chain reaction (PCR) to the samples, and then running the amplified copies through capillary electrophoresis to produce a readout of peak heights corresponding to alleles on various loci. The alleles correspond to the number of repeats of microsatellites that are usually two to six base pairs in length called short tandem repeats (STRs); the number of repeats of various STRs defines a person's DNA fingerprint. This process introduces artifacts in measurement. Of particular interest in this thesis is stutter, the phenomenon where amplicons with fewer or greater number of STR repeats than the true allele count are generated as an artifact of the PCR. It is of interest to understand the source and nature for this stutter distribution for small starting masses, as it has ramifications on the ability to accurately determine a match between a DNA sample and a crime scene sample. Understanding the stutter distribution in this thesis is achieved through data analysis, probabilistic modeling, and statistics. We find that a mathematical model that combines stochastic effects from PCR with fluorescent noise explains the most significant features of the observed phenomena.by Neil Gurram.M. Eng
Managed identities : How do Australian university students who stutter negotiate their studies?
Get PDFPrevious social research focused on people who stutter has problematised and largely ignored the experiences of university students who stutter, relying heavily upon surveys of teachers and peers while almost ignoring the authentic voices of students who stutter. Using a novel bricolage approach incorporating autoethnography, this project posed the question: “How do students who stutter negotiate their university experiences in Australia?” In 2008, a unique, web-based audit of 39 Australian public universities concluded that little publicly accessible information about stuttering support services was available for prospective university students. In many ways, stuttering is absent from disability classifications and service systems in higher education. An online survey of 102 Australian university students who stutter, and follow-up individual interviews with 15 students, revealed how these students manage their social identities from enrolment through to graduation. Only a minority of students reported ever formally disclosing their functional impairment to university support services or academic staff. This meant they rejected and/or avoided the disability label and associated stigma. The students were found to exercise a high degree of individual agency and creativity throughout their university journey. Many employed ‘concessional bargaining’ techniques to effectively navigate the oral assessment requirements during their degrees. Analysis of the interview and survey data is interspersed with critical self-reflection by the author – as a university lecturer who himself stutters. This thesis makes a significant contribution to shaping our understanding of the social identities and trajectories of university students who stutter. These students have been recast as positive, purposeful, resourceful and creative agents whose actions can be largely understood from a social model of disability. A series of recommendations for supporting and teaching these students are made to key stakeholders in higher education.Doctor of Philosoph
Stutter-Step Models of Performance in School
Get PDFThis is a pre-copyedited, author-produced version of an article accepted for publication in Social Forces following peer review. The version of record is available online at:
https://doi.org/10.1093/sf/sot037. Final version published as: Morgan, Stephen L., Theodore Leenman, Jennifer Todd, and Kim A. Weeden. 2013. Stutter-Step Models of Performance in School. Social Forces 91(4):1451- 1474.To evaluate a stutter-step model of academic performance in high school, this article adopts a unique measure of the beliefs of 12,591 high school sophomores from the Education Longitudinal Study, 2002-2006. Verbatim responses to questions on occupational plans are coded to capture specific job titles, the listing of multiple jobs, and the listing of multiple jobs with divergent characteristics. The educational requirements of detailed jobs, as specified in the Department of Labor's Occupational Information Network database, are then matched to all jobs that students list within their plans. Students with uncertain beliefs about their occupational futures are then shown to have lower levels of commitment to and performance in school. These results support the conjecture that uncertainty about the future has consequences for the short-run behavior that determines important educational outcomes, beyond the effects that are commonly attributed to existing models of performance
FLUIDITY SPEECH FORMATION AS A QUALITATIVE CHARACTERISTIC OF THE ORAL STATEMENT OF PRESCHOOL AGE CHILDREN WITH STUTTER
Get PDFThe research objective is to disclose the subject matter of speech therapy work focused on fluidity speech formation of preschool age children, suffering stutter. Stutter is a difficult disorder of articulation organs suchthat the tempo-rhythmical organisation of statements is distressed that leads to defects and failures of dialogue system, negatively influences on individual development of the child; more specifically it generates the mental stratifications, specific features of emotional-volitional sphere, and causes undesirable qualities ofcharacter such as shyness, indecision, isolation, negativism. The author notes that the problem of early stutter correction among junior preschool-aged children considered as topical and immediate issue. Methods. Concerning the clinical, physiological, psychological and psychologic-pedagogical positions, the author summarizes theoretical framework; an experimentally-practical approbation of an author's method of speech fluidity and stutter abolition of preschool children is described. Stage-by-stage process of correction,spontaneous and non-convulsive speech formation: 1. restraint mode application in order to decrease incorrect verbal output; 2. training exercises to long phonatory and speech expiration; 3. development of coordination and movements rhythm helping to pronounce words and phrases; 4. formation of situational speech, at first consisted of short sentences, then passing to long ones; 5. training to coherent text statements. The research demonstrates data analyses of postexperimental diagnostic examination of stuttering preschool children, proving the efficiency of the author’s applied method. Scientific novelty. The research findings demonstrate a specific approach to correction and stutter abolition of preschool children. Proposed author’s approach consists of complementary to each other directions of speech therapy work which are combines in the following way: coherent speech formation corresponding to age norms; the assistance in development of lexical and grammatical means of language; development of communicative skills. Practical significance. The identified methodological recommendations while correction-pedagogical process can be used for formation of communicative children readiness to school training and gaining experience of positive interaction with people around them. Timely measures aimed at speech acquisition of stuttering preschool children can warn possible deviations in mental development and prevent many difficulties due to their social adaptation. It is especially underlined that the guarantee of successful speech therapy work on stutter correction should be aimed at active interaction of experts with teachers of preschool educational institutions and parents
Resting-State Brain Activity in Adult Males Who Stutter
Get PDFAlthough developmental stuttering has been extensively studied with structural and task-based functional magnetic resonance imaging (fMRI), few studies have focused on resting-state brain activity in this disorder. We investigated resting-state brain activity of stuttering subjects by analyzing the amplitude of low-frequency fluctuation (ALFF), region of interest (ROI)-based functional connectivity (FC) and independent component analysis (ICA)-based FC. Forty-four adult males with developmental stuttering and 46 age-matched fluent male controls were scanned using resting-state fMRI. ALFF, ROI-based FCs and ICA-based FCs were compared between male stuttering subjects and fluent controls in a voxel-wise manner. Compared with fluent controls, stuttering subjects showed increased ALFF in left brain areas related to speech motor and auditory functions and bilateral prefrontal cortices related to cognitive control. However, stuttering subjects showed decreased ALFF in the left posterior language reception area and bilateral non-speech motor areas. ROI-based FC analysis revealed decreased FC between the posterior language area involved in the perception and decoding of sensory information and anterior brain area involved in the initiation of speech motor function, as well as increased FC within anterior or posterior speech-and language-associated areas and between the prefrontal areas and default-mode network (DMN) in stuttering subjects. ICA showed that stuttering subjects had decreased FC in the DMN and increased FC in the sensorimotor network. Our findings support the concept that stuttering subjects have deficits in multiple functional systems (motor, language, auditory and DMN) and in the connections between them
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