934 resultados para Self-techniques


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Two transgenic callus lines of rice, stably expressing a β-glucuronidase (GUS) gene, were supertransformed with a set of constructs designed to silence the resident GUS gene. An inverted-repeat (i/r) GUS construct, designed to produce mRNA with self-complementarity, was much more effective than simple sense and antisense constructs at inducing silencing. Supertransforming rice calluses with a direct-repeat (d/r) construct, although not as effective as those with the i/r construct, was also substantially more effective in silencing the resident GUS gene than the simple sense and antisense constructs. DNA hybridisation analyses revealed that every callus line supertransformed with either simple sense or antisense constructs, and subsequently showing GUS silencing, had the silence-inducing transgenes integrated into the plant genome in inverted-repeat configurations. The silenced lines containing i/r and d/r constructs did not necessarily have inverted-repeat T-DNA insertions. There was significant methylation of the GUS sequences in most of the silenced lines but not in the unsilenced lines. However, demethylation treatment of silenced lines with 5-azacytidine did not reverse the post-transcriptional gene silencing (PTGS) of GUS. Whereas the levels of RNA specific to the resident GUS gene were uniformly low in the silenced lines, RNA specific to the inducer transgenes accumulated to a substantial level, and the majority of the i/r RNA was unpolyadenylated. Altogether, these results suggest that both sense- and antisense-mediated gene suppression share a similar molecular basis, that unpolyadenylated RNA plays an important role in PTGS, and that methylation is not essential for PTGS.

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An RNA molecule with properties of a satellite RNA was found in an isolate of barley yellow dwarf virus (BYDV), RPV serotype. It is 322 nucleotides long, single-stranded, and does not hybridize to the viral genome. Dimers of the RNA, which presumably represent replicative intermediates, were able to self-cleave into monomers. In vitro transcripts from cDNA clones were capable of self-cleavage in both the plus (encapsidated) and minus orientations. The sequence flanking the minus strand cleavage site contained a consensus " hammerhead" structure, similar to those found in other self-cleaving satellite RNAs. Although related to the hammerhead structure, sequences flanking the plus strand termini showed differences from the consensus and may be folded into a different structure containing a pseudoknot. © 1991.

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This thesis introduces improved techniques towards automatically estimating the pose of humans from video. It examines a complete workflow to estimating pose, from the segmentation of the raw video stream to extract silhouettes, to using the silhouettes in order to determine the relative orientation of parts of the human body. The proposed segmentation algorithms have improved performance and reduced complexity, while the pose estimation shows superior accuracy during difficult cases of self occlusion.

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Taiwan nurses are mandated to report known or suspected child abuse and neglect (CAN), and self-efficacy is known to have an important influence on professional behaviors. The aim of this study was to develop and test the CAN reporting self-efficacy (CANRSE) scale as a measure of nurses’ self-efficacy to report CAN. A sample of 496 nurses from Southern Taiwanese hospitals used the CANRSE scale. The psychometric evaluation of the scale included content validity, exploratory and confirmatory factor analyses, convergent validity, as well as Cronbach’s α and test−retest reliability. Satisfactory internal consistency (Cronbach’s α = 0.92) and test−retest reliability were demonstrated. Confirmatory factor analysis supported the proposed models as having acceptable model fit. Exploratory factor analysis and regression analyses showed that the CANRSE scale had good construct validity and criterion-related validity, respectively. Convergent validity was tested using the general self-efficacy scale and was found to be satisfactory (r = 0.53). The results indicate the CANRSE is reliable and valid, and further testing of its predictive validity is recommended. It can be used to examine the influence of professional self-efficacy in recognizing and reporting CAN cases and to evaluate the impact of training programs aimed at improving CAN reporting.

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This paper presents a comparative study on the response of a buried tunnel to surface blast using the arbitrary Lagrangian-Eulerian (ALE) and smooth particle hydrodynamics (SPH) techniques. Since explosive tests with real physical models are extremely risky and expensive, the results of a centrifuge test were used to validate the numerical techniques. The numerical study shows that the ALE predictions were faster and closer to the experimental results than those from the SPH simulations which over predicted the strains. The findings of this research demonstrate the superiority of the ALE modelling techniques for the present study. They also provide a comprehensive understanding of the preferred ALE modelling techniques which can be used to investigate the surface blast response of underground tunnels.

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The objective of this study was to test for the measurement invariance of the Attention and Thought Problems subscales of the Child Behavior Checklist (CBCL) and Youth Self-Report (YSR) in a population-based sample of adolescents with and without epilepsy. Data were obtained from the 14-year follow-up of the Mater University Study of Pregnancy in which 33 adolescents with epilepsy and 1068 healthy controls were included for analysis. Confirmatory factor analysis was used to test for measurement invariance between adolescents with and without epilepsy. Structural equation modeling was used to test for group differences in attention and thought problems as measured with the CBCL and YSR. Measurement invariance was demonstrated for the original CBCL Attention Problems and YSR Thought Problems. After the removal of ambiguous items (“confused” and “daydreams”),measurement invariance was established for the YSR Attention Problems. The original and reduced CBCL Thought Problems were noninvariant. Adolescents with epilepsy had significantly more symptoms of behavioral problems on the CBCL Attention Problems, β = 0.51, p = 0.002, compared with healthy controls. In contrast, no significant differences were found for the YSR Attention and Thought Problems, β = −0.11, p = 0.417 and β = −0.20, p = 0.116, respectively. In this population-based sample of adolescents with epilepsy, the CBCL Attention Problems and YSR Thought Problems appear to be valid measures of behavioral problems, whereas the YSR Attention Problems was valid only after the removal of ambiguous items. Replication of these findings in clinical samples of adolescents with epilepsy that overcome the limitations of the current study is warranted.

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Purpose. To compare self-assessed driving habits and skills of licensed drivers with central visual loss who use bioptic telescopes to those of age-matched normally sighted drivers, and to examine the association between bioptic drivers' impressions of the quality of their driving and ratings by a “backseat” evaluator. Methods. Participants were licensed bioptic drivers (n = 23) and age-matched normally sighted drivers (n = 23). A questionnaire was administered addressing driving difficulty, space, quality, exposure, and, for bioptic drivers, whether the telescope was helpful in on-road situations. Visual acuity and contrast sensitivity were assessed. Information on ocular diagnosis, telescope characteristics, and bioptic driving experience was collected from the medical record or in interview. On-road driving performance in regular traffic conditions was rated independently by two evaluators. Results. Like normally sighted drivers, bioptic drivers reported no or little difficulty in many driving situations (e.g., left turns, rush hour), but reported more difficulty under poor visibility conditions and in unfamiliar areas (P < 0.05). Driving exposure was reduced in bioptic drivers (driving 250 miles per week on average vs. 410 miles per week for normally sighted drivers, P = 0.02), but driving space was similar to that of normally sighted drivers (P = 0.29). All but one bioptic driver used the telescope in at least one driving task, and 56% used the telescope in three or more tasks. Bioptic drivers' judgments about the quality of their driving were very similar to backseat evaluators' ratings. Conclusions. Bioptic drivers show insight into the overall quality of their driving and areas in which they experience driving difficulty. They report using the bioptic telescope while driving, contrary to previous claims that it is primarily used to pass the vision screening test at licensure.

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Background Post-stroke recovery is demanding. Increasing studies have examined the effectiveness of self-management programs for stroke survivors. However no systematic review has been conducted to summarize the effectiveness of theory-based stroke self-management programs. Objectives The aim is to present the best available research evidence about effectiveness of theory-based self-management programs on community-dwelling stroke survivors’ recovery. Inclusion criteria Types of participants All community-residing adults aged 18 years or above, and had a clinical diagnosis of stroke. Types of interventions Studies which examined effectiveness of a self-management program underpinned by a theoretical or conceptual framework for community-dwelling stroke survivors. Types of studies Randomized controlled trials. Types of outcomes Primary outcomes included health-related quality of life and self-management behaviors. Secondary outcomes included physical (activities of daily living), psychological (self-efficacy, depressive symptoms), and social outcomes (community reintegration, perceived social support). Search Strategy A three-step approach was adopted to identify all relevant published and unpublished studies in English or Chinese. Methodological quality The methodological quality of the included studies was assessed using the Joanna Briggs Institute critical appraisal checklist for experimental studies. Data Collection A standardized JBI data extraction form was used. There was no disagreement between the two reviewers on the data extraction results. Data Synthesis There were incomplete details about the number of participants and the results in two studies, which makes it impossible to perform meta-analysis. A narrative summary of the effectiveness of stroke self-management programs is presented. Results Three studies were included. The key issues of concern in methodological quality included insufficient information about random assignment, allocation concealment, reliability and validity of the measuring instruments, absence of intention-to-treat analysis, and small sample sizes. The three programs were designed based on the Stanford Chronic Disease Self-management program and were underpinned by the principles of self-efficacy. One study showed improvement in the intervention group in family and social roles three months after program completion, and work productivity at six months as measured by the Stroke Specific Quality of Life Scale (SSQOL). The intervention group also had an increased mean self-efficacy score in communicating with physicians six months after program completion. The mean changes from baseline in these variables were significantly different from the control group. No significant difference was found in time spent in aerobic exercise between the intervention and control groups at three and six months after program completion. Another study, using SSQOL, showed a significant interaction effect by treatment and time on family roles, fine motor tasks, self-care, and work productivity. However there was no significant interaction by treatment and time on self-efficacy. The third study showed improvement in quality of life, community participation, and depressive symptoms among the participants receiving the stroke self-management program, Stanford Chronic Disease Self-management program, or usual care six months after program completion. However, there was no significant difference between the groups. Conclusions There is inconclusive evidence about the effectiveness of theory-based stroke self-management programs on community-dwelling stroke survivors’ recovery. However the preliminary evidence suggests potential benefits in improving stroke survivors’ quality of life and self-efficacy.

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This paper proposes techniques to improve the performance of i-vector based speaker verification systems when only short utterances are available. Short-length utterance i-vectors vary with speaker, session variations, and the phonetic content of the utterance. Well established methods such as linear discriminant analysis (LDA), source-normalized LDA (SN-LDA) and within-class covariance normalisation (WCCN) exist for compensating the session variation but we have identified the variability introduced by phonetic content due to utterance variation as an additional source of degradation when short-duration utterances are used. To compensate for utterance variations in short i-vector speaker verification systems using cosine similarity scoring (CSS), we have introduced a short utterance variance normalization (SUVN) technique and a short utterance variance (SUV) modelling approach at the i-vector feature level. A combination of SUVN with LDA and SN-LDA is proposed to compensate the session and utterance variations and is shown to provide improvement in performance over the traditional approach of using LDA and/or SN-LDA followed by WCCN. An alternative approach is also introduced using probabilistic linear discriminant analysis (PLDA) approach to directly model the SUV. The combination of SUVN, LDA and SN-LDA followed by SUV PLDA modelling provides an improvement over the baseline PLDA approach. We also show that for this combination of techniques, the utterance variation information needs to be artificially added to full-length i-vectors for PLDA modelling.

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Students making the transition from high school to university often encounter many stressors and new experiences. Many students adjust successfully to university; however, some students do not, often resulting in attrition from the university and mental health issues. The primary aim of the current study was to examine the effects that optimism, self-efficacy, depression, and anxiety have on an individual's life stress and adaptation to university. Eighty-four first-year, full-time students from the Queensland University of Technology (60 female, 24 male) who had entered university straight from high school completed the study. Participants completed a questionnaire assessing their levels of optimism, self-efficacy, depression, anxiety, perceived level of life stress and adaptation to university. In line with predictions, results showed that optimism, depression, and anxiety each had a significant relationship with students’ perceived level of stress. Furthermore, self-efficacy and depression had a significant relationship with adaptation to university. We conclude that students with high levels of optimism and low levels of depression and anxiety will adapt better when making the transition from high school to university. In addition, students with high levels of self-efficacy and low levels of depression will experience less life stress in their commencement year of university. The implications of this study are outlined.

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Background: Self-selection-whether individuals inclined to walk more seek to live in walkable environments-must be accounted for when studying built environment influences on walking. The way neighborhoods are marketed to future residents has the potential to sway residential location choice, and may consequently affect measures of self-selection related to location preferences. We assessed how walking opportunities are promoted to potential buyers, by examining walkability attributes in marketing materials for housing developments. Methods: A content analysis of marketing materials for 32 new housing developments in Perth, Australia was undertaken, to assess how walking was promoted in the text and pictures. Housing developments designed to be pedestrian-friendly (LDs) were compared with conventional developments (CDs). Results: Compared with CDs, LD marketing materials had significantly more references to 'public transport,' small home sites,' walkable parks/open space,' ease of cycling,' safe environment,' and 'boardwalks.' Other walkability attributes approached significance. Conclusion: Findings suggest the way neighborhoods are marketed may contribute to self-reported reasons for choosing particular neighborhoods, especially when attributes are not present at the time of purchase. The marketing of housing developments may be an important factor to consider when measuring self-selection, and its influence on the built environment and walking relationship.

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Aim Physical activity (PA) patterns of retirement village residents were investigated using self-report and objective measures. Methods Residents (n = 323) from retirement villages in Perth, Australia, were surveyed on PA behaviour and various demographic, residency, health-related and mobility factors. Most participants wore accelerometers for 7 days. Retirement village managers (n = 32) were surveyed on village descriptive characteristics, including the provision of amenities and facilities. Logistic regression models examined village and resident characteristics associated with PA. Results Based on objective measurement, only 27.1% of participants were sufficiently active (n = 288). Walking was one of the most popular PA modes. Few village characteristics were associated with PA; however, villages located in more walkable neighbourhoods increased participants’ odds of transport walking. Travelling outside the village daily also increased PA odds. Conclusions Most residents were insufficiently active to gain health benefits. Considering individual and environmental factors, within the retirement village and neighbourhood settings, and associations with PA, warrants attention.

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Introduction: Dental and medical students worldwide, including in Saudi Arabia, have been reported to have a high incidence of poor psychological health, such as depression, stress, anxiety, and lowlife satisfaction. Self-development coaching programs have become an increasingly popular way to improve individuals’ lives. However, few studies have evaluated the psychological effects of such programs among dental and medical students. Moreover, no studies have been conducted on self-development coaching programs in Saudi Arabia. Aims: The aim of this study was to assess the feasibility of a larger study via a pilot study and to acquire preliminary findings about the effectiveness of a self-development coaching program on psychological health among dental and medical students in Saudi Arabia. Methods: A pre-post interventional study design was used to test a self-development coaching program (How to be an Ultra-Super Student) with a sample of medical students (n=17) at Umm Al-Qura University at Saudi Arabia. The outcome measures were students’ psychological distress (depression, anxiety, and stress), life satisfaction, self-efficacy, the coach, and coaching program characteristics. Results: The study showed that there was a significant improvement in depression (p=0.04), self-efficacy (p=0.02), and satisfaction with life (p=0.04), which supported the feasibility of a large study in the future. Conclusions: The study’s findings encourage the implementation of a randomized, controlled trial study with a larger sample to further test the effectiveness of using self-development coaching programs with medical and dental students in Saudi Arabia to improve their psychological health.

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Background and aims Self-efficacy beliefs and outcome expectancies are central to Social Cognitive Theory (SCT). Alcohol studies demonstrate the theoretical and clinical utility of applying both SCT constructs. This study examined the relationship between refusal self-efficacy and outcome expectancies in a sample of cannabis users, and tested formal mediational models. Design Patients referred for cannabis treatment completed a comprehensive clinical assessment, including recently validated cannabis expectancy and refusal self-efficacy scales. Setting A hospital alcohol and drug out-patient clinic. Participants Patients referred for a cannabis treatment [n = 1115, mean age 26.29, standard deviation (SD) 9.39]. Measurements The Cannabis Expectancy Questionnaire (CEQ) and Cannabis Refusal Self-Efficacy Questionnaire (CRSEQ) were completed, along with measures of cannabis severity [Severity of Dependence Scale (SDS)] and cannabis consumption. Findings Positive (β = −0.29, P < 0.001) and negative (β = −0.19, P < 0.001) cannabis outcome expectancies were associated significantly with refusal self-efficacy. Refusal self-efficacy, in turn, fully mediated the association between negative expectancy and weekly consumption [95% confidence interval (CI) = 0.03, 0.17] and partially mediated the effect of positive expectancy on weekly consumption (95% CI = 0.06, 0.17). Conclusions Consistent with Social Cognitive Theory, refusal self-efficacy (a person's belief that he or she can abstain from cannabis use) mediates part of the association between cannabis outcome expectancies (perceived consequences of cannabis use) and cannabis use.

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Background: There is a paucity of research assessing health-related quality of life (HRQoL) and self-efficacy in caregivers of relatives with dementia in mainland China. Aims: To compare the level of HRQoL between caregivers and the general population in mainland China and to assess the role of caregiver self-efficacy in the relationship between caregiver social support and HRQoL. Methods: A cross-sectional study was conducted in Shanghai, China. The caregivers were recruited from the outpatient department of a teaching hospital. A total of 195 participants were interviewed, using a survey package including the Chinese version of the 36-Item Short-Form Health Survey (SF-36), demographic data, the variables associated with the impairments of care recipients, perceived social support and caregiver self-efficacy. The caregivers' SF-36 scores were compared with those of the general population in China. Results: The results indicated that the HRQoL of the caregivers was poorer compared with that of the general population when matched for age and gender. Multiple regression analyses revealed that caregiver self-efficacy is a partial mediator between social support and HRQoL, and a partial mediator between behavioral and psychological symptoms of dementia (BPSD) and caregiver mental health. Conclusion: Assisting with managing BPSD and enhancing caregiver self-efficacy can be considered integral parts of interventions to improve caregiver HRQoL.