937 resultados para predictor


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Background and objectives: Cognitive models suggest that attentional biases are integral in the maintenance of obsessive-compulsive symptoms (OCS). Such biases have been established experimentally in anxiety disorders; however, the evidence is unclear in Obsessive Compulsive disorder (OCD). In the present study, an eye-tracking methodology was employed to explore attentional biases in relation to OCS.
Methods: A convenience sample of 85 community volunteers was assessed on OCS using the Yale-Brown Obsessive Compulsive Scale-self report. Participants completed an eye-tracking paradigm where they were exposed to OCD, Aversive and Neutral visual stimuli. Indices of attentional bias were derived from the eye-tracking data.
Results: Simple linear regressions were performed with OCS severity as the predictor and eye-tracking measures of the different attentional biases for each of the three stimuli types were the criterion variables. Findings revealed that OCS severity moderately predicted greater frequency and duration of fixations on OCD stimuli, which reflect the maintenance attentional bias. No significant results were found in support of other biases.
Limitations: Interpretations based on a non-clinical sample limit the generalisability of the conclusions, although use of such samples in OCD research has been found to be comparable to clinical populations. Future research would include both clinical and sub-clinical participants.
Conclusions: Results provide some support for the theory of maintained attention in OCD attentional biases, as opposed to vigilance theory. Individuals with greater OCS do not orient to OCD stimuli any faster than individuals with lower OCS, but once a threat is identified, these individuals allocate more attention to OCS-relevant stimuli.

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The Arc-Length Method is a solution procedure that enables a generic non-linear problem to pass limit points. Some examples are provided of mode-jumping problems solutions using a commercial nite element package, and other investigations are carried out on a simple structure of which the numerical solution can be compared with an analytical one. It is shown that Arc-Length Method is not reliable when bifurcations are present in the primary equilibrium path; also the presence of very sharp snap-backs or special boundary conditions may cause convergence diÆculty at limit points. An improvement to the predictor used in the incremental procedure is suggested, together with a reliable criteria for selecting either solution of the quadratic arc-length constraint. The gap that is sometimes observed between the experimantal load level of mode-jumping and its arc-length prediction is explained through an example.

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The density and composition of stream bed metal deposits are affected by physical, chemical and biological processes. In this paper we investigate the importance of these processes and their relation to algal and non-photosynthetic detrital (NPD) biomass in a set of upland streams in Northern Ireland. Deposit density and Fe, Mn, Al and P concentrations varied with stream pH across sites but not seasonally. No effects of stream bed erosion or photoreduction were detected on deposit densities. Seasonal variation in stream water metal concentrations was correlated with rainfall. NPD biomass was a significant predictor of both spatial and seasonal variation in deposit concentrations. There were strong, non-linear, relations between NPD biomass and deposit metal concentrations, with Fe and Mn becoming relatively more important and algal biomass declining above threshold deposit/NPD densities. The results suggest that NPD biomass influences deposit density and reduces the biomass of photosynthetic autotrophs above a threshold deposit density.

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The use of portion control practices has rarely been quantified. The present study aimed to: (1) explore which portion control practices are actually used by the general population and their association with cognitive restraint, demographic background and general health interest (GHI), and (2) examine how the usage of portion control practices predicts the estimated consumption of an energy dense food (i.e. pizza). Twenty-two portion control practices were rated in terms of their frequency of use from 'never' to 'very often' by a representative sample of 1012 consumers from the island of Ireland. Three factors were extracted and named: measurement-strategy scale, eating-strategy scale, and purchasing-strategy scale. The eating-strategy scale score was the highest, while the measurement-strategy scale carried the lowest frequency score. For each strategy scale score, the strongest predictor was GHI, followed by gender. Having higher GHI and being female were independently associated with more frequent portion control. Both the eating-strategy scale score and the purchasing-strategy scale score were negatively associated with pizza portion size consumption estimates. In conclusion, while this study demonstrates that the reported use of portion control practices is low, the findings provide preliminary evidence for their validity. Further studies are needed to explore how portion control practices are used in different kinds of portion size decisions and what their contribution is to the intake of food over an extended period of time.

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Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs) of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in “100 of the World's Worst Invasive Alien Species”; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest “attack rates” a, shortest “handling times” h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach.

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Purpose:
This study explored how meal-related variables, socio-demographics and psychological predispositions affect the portion
size and perceived fillingness of an evening meal in Danish and Irish households.
Methods:
Using survey data collected in 2115 respondents from Denmark (DK) and the Island of Ireland (IOI), we compared four
sets of predictors of the portion size chosen for four evening meals (i.e. pizza/soup/chicken salad/pork meal): Biological
variables (hunger, thirst), socio-demographic variables (gender, age, BMI); psychological predispositions (cognitive
restraint, uncontrolled eating, emotional eating, general health interest) and meal-related variables (expected fillingness,
perceived healthiness, liking, frequency of consumption). We also compared five sets of predictors (the previous
four plus portion size) of perceived portion fillingness.
Results:
Portion size selections were associated mainly with demographic variables (gender, BMI) and psychological predispositions
(cognitive restraint, uncontrolled eating). In addition, only liking and sometimes expected healthiness (mealrelated
variables) appeared as drivers. Conversely, perceived portion fillingness was mostly influenced by the selected
portion size as well as expected fillingness and liking. There were some differences between meals; e.g. GHI not a
predictor for Pizza but a predictor for Chicken salad. Also some country differences were observed; emotional eating
predicted portion selection in the IOI but not DK.
Conclusions:
When making portion size selections at home, psychological predispositions, restrained and uncontrolled eating as well
as meal-related variables, liking and healthiness explained the decisions. However, surprisingly, individuals’ expected
fillingness of a food did not influence their portion size selection but was a driver of fillingness of the selected portion.

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Introduction: Neutrophil elastase (NE) is a serine protease implicated in the pathogenesis of several respiratory diseases including cystic fibrosis (CF). The presence of free NE in BAL is a predictor of subsequent bronchiectasis in children with CF (Sly et al, 2013, NEJM 368: 1963-1970). Furthermore, children with higher levels of sputum NE activity (NEa) tend to experience a more rapid decline in FEV1 over time even after adjusting for age, gender and baseline FEV1 (Sagel et al, 2012, AJRCCM 186: 857-865). Its detection and quantification in biological samples is however confounded by a lack of robust methodologies. Standard assays using chromogenic or fluorogenic substrates are not specific when added to complex samples containing multiple proteolytic and hydrolytic enzymes. ELISA systems measure total protein levels which can be a mixture of latent, active and protease-inhibitor complexes. We have therefore developed a novel assay (ProteaseTag™ Active NE Immunoassay), which couples an activity dependent NE-Tag with a specific antibody step, resulting in an assay which is both selective and specific for NEa. Aims: To clinically validate ProteaseTag™ Active NE for the detection of free NEa in BAL from children with CF. Methods: A total of 95 paediatric BAL samples [CF (n=76; 44M, 32F) non-CF (n=19; 12M, 7F)] collected through the Study of Host Immunity and Early Lung Disease in CF (SHIELD CF) were analysed for NEa using ProteaseTag™ Active NE (ProAxsis Ltd) and a fluorogenic substrate-based assay utilising Suc-AAPV-AMC (Sigma). IL-8 was measured by ELISA (R&D Systems). Results were analysed to show comparisons in free NEa between CF and non-CF samples alongside correlations with a range of clinical parameters. Results: NEa measured by ProteaseTag™ Active NE correlated significantly with age (r=0.3, p=0.01) and highly significantly with both IL-8 (r=0.4, p=<0.0001) and the absolute neutrophil count (ANC) (r=0.4, p=<0.0001). These correlations were not observed when NEa was measured by the substrate assay even though a significant correlation was found between the two assays (r=0.8, p<0.0001). A trend towards significance was found between NEa in the CF and non-CF groups when measured by ProteaseTag™ Active NE (p=0.07). Highly significant differences were found with the other inflammatory parameters between the 2 groups (IL-8: p=0.0002 and ANC: p=0.006). Conclusion: NEa as a primary efficacy endpoint in clinical trials or as a marker of inflammation within the clinic has been hampered by the lack of a robust and simple to use assay. ProteaseTag™ Active NE has been shown to be a specific and superior tool in the measurement of NEa in paediatric CF BAL samples (supporting data from previous studies using adult CF expectorated samples). The technology is currently being transferred to a lateral flow device for use at Point of Care. Acknowledgements: This work was supported by the National Children’s Research Centre, Dublin (SHIELD CF) and grants from the Medical Research Council and Cystic Fibrosis Foundation Therapeutics.

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This work investigated the differences in the reactivity of Sarda (primiparous n= 18, multiparous n= 17) and Dorset (multiparous n= 8) breeds of sheep and their singleton lambs to two challenging test situations involving a mother-lamb partial separation test and an isolation test. Non-parametric analysis used single behavioural variables and fear scores to evaluate the effect of parity, sex of lambs, and the association between mother-lamb behaviour. Amongst ewes, Dorset were characterised by a more calm temperament while Sarda (especially primiparous ewes) were more active in their response to challenge (i.e. more attempts to escape). As with their dams, lambs reflected to a certain extent this divergence and overall during isolation lamb fear score was on average significantly higher than dams. Correlations between measures of behavioural reactivity across tests were carried out to search for predictive measures of fear. A very strong correlation emerged linking vocalisation to locomotor activity. Vocalisation could be a good candidate as predictor factor of an active reaction of sheep to a fearful situation.

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Purpose: To identify factors associated prospectively with increased cataract surgical rate (CSR) in rural Chinese hospitals.

Methods: Annual cataract surgical output was obtained at baseline and 24 months later from operating room records at 42 rural, county-level hospitals. Total local CSR (cases/million population/y), and proportion of CSR from hospital and local competitors were calculated from government records. Hospital administrators completed questionnaires providing demographic and professional information, and annual clinic and outreach screening volume. Independent cataract surgeons provided clinical information and videotapes of cases for grading by two masked experts using the Ophthalmology Surgical Competency Assessment Rubric (OSCAR). Uncorrected vision was recorded for 10 consecutive cataract cases at each facility, and 10 randomly-identified patients completed hospital satisfaction questionnaires. Total value of international nongovernmental development organization (INGDO) investment in the previous three years and demographic information on hospital catchment areas were obtained. Main outcome was 2-year percentage change in hospital CSR.

Results: Among the 42 hospitals (median catchment population 530,000, median hospital CSR 643), 78.6% (33/42) were receiving INGDO support. Median change in hospital CSR (interquartile range) was 33.3% (-6.25%, 72.3%). Predictors of greater increase in CSR included higher INGDO investment (P = 0.02, simple model), reducing patient dissatisfaction (P = 0.03, simple model), and more outreach patient screening (P = 0.002, simple and multiple model).

Conclusions: Outreach cataract screening was the strongest predictor of increased surgical output. Government and INGDO investment in screening may be most likely to enhance output of county hospitals, a major goal of China's Blindness Prevention Plan.

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Background: EpHA2 is a 130 kD transmembrane glycoprotein belonging to ephrin receptor subfamily and involved in angiogenesis/tumour neovascularisation. High EpHA2 mRNA level has recently been implicated in cetuximab resistance. Previously, we found high EpHA2 levels in a panel of invasive colorectal cancer (CRC) cells, which was associated with high levels of stem-cell marker CD44. Our aim was to investigate the prognostic value of EpHA2 and subsequently correlate expression levels to known clinico-pathological variables in early stage CRC. Methods: Tissue samples from 509 CRC patients were analysed. EpHA2 expression was measured using IHC. Kaplan-Meier graphs were used. Univariate and multivariate analyses employed Cox Proportional Hazards Ratio (HR) method. A backward selection method (Akaike’s information criterion) was used to determine a refined multivariate model. Results: EpHA2 was highly expressed in CRC adenocarcinoma compared to matched normal colon tissue. In support of our preclinical invasive models, strong correlation was found between EpHA2 expression and CD44 and Lgr5 staining (p<0.001). In addition, high EpHA2 expression significantly correlated with vascular invasion (p=0.03).HR for OS for stage II/III patients with high EpHA2 expression was 1.69 (95%CI: 1.164-2.439; p=0.003). When stage II/III was broken down into individual stages, there was significant correlation between high EpHA2 expression and poor 5-years OS in stage II patients (HR: 2.18; 95%CI: 1.28-3.71; p=0.005).HR in the stage III group showed a trend to statistical significance (HR: 1.48; 95%CI=0.87-2.51; p=0.05). In both univariate and multivariate analyses of stage II patients, high EpHA2 expression was the only significant factor and was retained in the final multivariate model. Higher levels of EpHA2 were noted in our RAS and BRAF mutant CRC cells, and silencing EpHA2 resulted in significant decreases in migration/invasion in parental and invasive CRC sublines. Correlation between KRAS/NRAS/BRAFmutational status and EpHA2 expression in clinical samples is ongoing. Conclusions: Taken together, our study is the first to indicate that EpHA2 expression is a predictor of poor clinical outcome and a potential novel target in early stage CRC.

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Background: The perceived difficulty of steps of manual small incision cataract surgery among trainees in rural China was assessed. Design: Cohort study. Participants: Fifty-two trainees at the end of a manual small incision cataract surgery training programme. Methods: Participants rated the difficulty of 14 surgical steps using a 5-point scale, 1 (very easy) to 5 (very difficult). Demographic and professional information was recorded for trainees. Main Outcome Measure: Mean ratings for surgical steps. Results: Questionnaires were completed by 49 trainees (94.2%, median age 38 years, 8 [16.3%] women). Twenty six (53.1%) had performed ≤50 independent cataract surgeries prior to training. Trainees rated cortical aspiration (mean score±standard deviation=3.10±1.14) the most difficult step, followed by wound construction (2.76±1.08), nuclear prolapse into the anterior chamber (2.74±1.23) and lens delivery (2.51±1.08). Draping the surgical field (1.06±0.242), anaesthetic block administration (1.14±0.354) and thermal coagulation (1.18±0.441) were rated easiest. In regression models, the score for cortical aspiration was significantly inversely associated with performing >50 independent manual small incision cataract surgery surgeries during training (P=0.01), but not with age, gender, years of experience in an eye department or total number of cataract surgeries performed prior to training. Conclusions: Cortical aspiration, wound construction and nuclear prolapse pose the greatest challenge for trainees learning manual small incision cataract surgery, and should receive emphasis during training. Number of cases performed is the strongest predictor of perceived difficulty of key steps. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

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AIM: To study patient sources of knowledge about cataract surgical services, and strategies for financing surgery in rural China. DESIGN: Cross-sectional case series. METHODS: Patients undergoing cataract surgery by local surgeons in a government, village-level facility in Sanrao, Guangdong between 8 August and 31 December 2005 were examined and had standardised interviews an average of 12 months after surgery. RESULTS: Of 313 eligible patients, 239 (76%) completed the questionnaire. Subjects had a mean (SD) age of 69.9 (10.2) years, 36.4% (87/239) were male, and 87.0% (208/239) had been blind (presenting visual acuity < or = 6/60) before surgery. Word-of-mouth advertising was particularly important: 198 (85.0%) of the subjects knew a person who had undergone cataract surgery, of whom 191 (96.5%) had had cataract surgery at Sanrao itself. Over 70% of subjects (166/239) watched TV daily, whereas 80.0% (188/239) "never" read the newspaper. Nearly two-thirds of suggestions from participants (n = 211, 59.6%) favoured either TV advertisements or word-of-mouth to publicise the programme. While the son or daughter had paid for surgery in over 70% of cases (164/233), the patient's having paid without help was the sole predictor of undergoing second-eye surgery (OR 2.27 (95% CI 1.01 to 5.0, p = 0.04)). DISCUSSION: Strategies to increase uptake of cataract surgery in rural China may benefit from enhancing word-of-mouth advertising (such as with pseudophakic motivators), using television advertising where affordable, and micro-credit or other programmes to enable patients to pay their own fees, thus increasing uptake of second-eye surgery.

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Older adults use a different muscle strategy to cope with postural instability, in which they ‘co-contract’ the muscles around the ankle joint. It has been suggested that this is a compensatory response to age-related proprioceptive decline however this view has never been assessed directly. The current study investigated the association between proprioceptive acuity and muscle co-contraction in older adults. We compared muscle activity, by recording surface EMG from the bilateral tibalis anterior and gastrocnemius medialis muscles, in young (aged 18-34) and older adults (aged 65-82) during postural assessment on a fixed and sway-referenced surface at age-equivalent levels of sway. We performed correlations between muscle activity and proprioceptive acuity, which was assessed using an active contralateral matching task. Despite successfully inducing similar levels of sway in the two age groups, older adults still showed higher muscle co-contraction. A stepwise regression analysis showed that proprioceptive acuity measured using variable error was the best predictor of muscle co-contraction in older adults. However, despite suggestions from previous research, proprioceptive error and muscle co-contraction were negatively correlated in older adults, suggesting that better proprioceptive acuity predicts more co-contraction. Overall, these results suggest that although muscle co-contraction may be an age-specific strategy used by older adults, it is not to compensate for age-related proprioceptive deficits.

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BACKGROUND: Sleep-disordered breathing is a common and serious feature of many paediatric conditions and is particularly a problem in children with Down syndrome. Overnight pulse oximetry is recommended as an initial screening test, but it is unclear how overnight oximetry results should be interpreted and how many nights should be recorded.

METHODS: This retrospective observational study evaluated night-to-night variation using statistical measures of repeatability for 214 children referred to a paediatric respiratory clinic, who required overnight oximetry measurements. This included 30 children with Down syndrome. We measured length of adequate trace, basal SpO2, number of desaturations (>4% SpO2 drop for >10 s) per hour ('adjusted index') and time with SpO2<90%. We classified oximetry traces into normal or abnormal based on physiology.

RESULTS: 132 out of 214 (62%) children had three technically adequate nights' oximetry, including 13 out of 30 (43%) children with Down syndrome. Intraclass correlation coefficient for adjusted index was 0.54 (95% CI 0.20 to 0.81) among children with Down syndrome and 0.88 (95% CI 0.84 to 0.91) for children with other diagnoses. Negative predictor value of a negative first night predicting two subsequent negative nights was 0.2 in children with Down syndrome and 0.55 in children with other diagnoses.

CONCLUSIONS: There is substantial night-to-night variation in overnight oximetry readings among children in all clinical groups undergoing overnight oximetry. This is a more pronounced problem in children with Down syndrome. Increasing the number of attempted nights' recording from one to three provides useful additional clinical information.

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This study considers the potential for influencing business students to become ethical managers by directing their undergraduate learning environment. In particular, the relationship between business students’ academic cheating, as a predictor of workplace ethical behavior, and their approaches to learning is explored. The three approaches to learning identified from the students’ approaches to learning literature are deep approach, represented by an intrinsic interest in and a desire to understand the subject, surface approach, characterized by rote learning and memorization without understanding, and strategic approach, associated with competitive students whose motivation is the achievement of good grades by adopting either a surface or deep approach. Consistent with the hypothesized theoretical model, structural equation modeling revealed that the surface approach is associated with higher levels of cheating, while the deep approach is related to lower levels. The strategic approach was also associated with less cheating and had a statistically stronger influence than the deep approach. Further, a significantly positive relationship reported between deep and strategic approaches suggests that cheating is reduced when deep and strategic approaches are paired. These findings suggest that future managers and business executives can be influenced to behave more ethically in the workplace by directing their learning approaches. It is hoped that the evidence presented may encourage those involved in the design of business programs to implement educational strategies which optimize students’ approaches to learning towards deep and strategic characteristics, thereby equipping tomorrow’s managers and business executives with skills to recognize and respond appropriately to workplace ethical dilemmas.