863 resultados para change detection, visione stereo, background difference
Resumo:
The effect of liming on the flow of recently photosynthesized carbon to rhizosphere soil was studied using (CO2)-C-13 pulse labelling, in an upland grassland ecosystem in Scotland. The use of C-13 enabled detection, in the field, of the effect of a 4-year liming period of selected soil plots on C allocation from plant biomass to soil, in comparison with unlimed plots. Photosynthetic rates and carbon turnover were higher in plants grown in limed soils than in those from unlimed plots. Higher delta(13)C% values were detected in shoots from limed plants than in those from unlimed plants in samples clipped within 15 days of the end of pulse labelling. Analysis of the aboveground plant production corresponding to the 4-year period of liming indicated that the standing biomass was higher in plots that received lime. Lower delta(13)C% values in limed roots compared with unlimed roots were found, whereas no significant difference was detected between soil samples. Extrapolation of our results indicated that more C has been lost through the soil than has been gained via photosynthetic assimilation because of pasture liming in Scotland during the period 1990-1998. However, the uncertainty associated with such extrapolation based on this single study is high and these estimates are provided only to set our findings in the broader context of national soil carbon emissions.
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When people evaluate syllogisms, their judgments of validity are often biased by the believability of the conclusions of the problems. Thus, it has been suggested that syllogistic reasoning performance is based on an interplay between a conscious and effortful evaluation of logicality and an intuitive appreciation of the believability of the conclusions (e.g., Evans, Newstead, Allen, & Pollard, 1994). However, logic effects in syllogistic reasoning emerge even when participants are unlikely to carry out a full logical analysis of the problems (e.g., Shynkaruk & Thompson, 2006). There is also evidence that people can implicitly detect the conflict between their beliefs and the validity of the problems, even if they are unable to consciously produce a logical response (e.g., De Neys, Moyens, & Vansteenwegen, 2010). In 4 experiments we demonstrate that people intuitively detect the logicality of syllogisms, and this effect emerges independently of participants' conscious mindset and their cognitive capacity. This logic effect is also unrelated to the superficial structure of the problems. Additionally, we provide evidence that the logicality of the syllogisms is detected through slight changes in participants' affective states. In fact, subliminal affective priming had an effect on participants' subjective evaluations of the problems. Finally, when participants misattributed their emotional reactions to background music, this significantly reduced the logic effect.
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Abstract
Background Physical inactivity is a major public health concern, and more innovative approaches are urgently needed to address it. The UK Government supports the use of incentives and so-called nudges to encourage healthy behaviour changes, and has encouraged business sector involvement in public health through the Public Health Responsibility Deal. To test the effectiveness of provision of incentives to encourage adults to increase their physical activity, we
recruited 406 adults from a workplace setting (office-based) to take part in an assessor-blind randomised controlled trial.
Methods
We developed the physical activity loyalty card scheme, which integrates a novel physical activity tracking system with web-based monitoring (palcard). Participants were recruited from two buildings at Northern Ireland’s main
government offices and were randomly allocated (grouped by building [n=2] to reduce contamination) to either incentive group (n=199) or no incentive group (n=207). We included participants aged 16–65 years, based at the worksite 4 days or more per week and for 6 h or more per day, and able to complete 15 min of moderate-paced walking (self-report). Exclusion criteria included having received specific advice by a general practitioner not to exercise. A statistician not involved in administration of the trial prepared a computer-generated random allocation sequence. Random assignments were placed in individually numbered, sealed envelopes by the statistician to ensure concealment of allocation. Only the assessor was masked to assignment. Sensors were placed along footpaths and the gym in the workplace. Participants scanned their loyalty card at the sensor when undertaking physical activity (eg, walking), which logged activity. Participants in the incentive group monitored their physical activity, collected points, and received rewards (retail vouchers) for minutes of physical activity completed over the 12-week intervention. Rewards were vouchers sponsored by local retailers. Participants in the no incentive group used their loyalty card to self-monitor their physical activity but were not able to earn points or receive rewards. The primary outcome was change in minutes of moderate to vigorous physical activity with the Global Physical Activity Questionnaire, measured at baseline, week 12, and 6 months. Activity was objectively measured with the tracking system over the 12-week intervention. Mann Whitney U tests were done to assess change between groups.
Findings
The mean age of participants was 43·32 years (SD 9·37), and 272 (67%) were women. We obtained follow-up data from 353 (87%) participants at week 12 and 341 (84%) at 6 months. At week 12, participants in the incentive group increased moderate to vigorous physical activity by a median of 60 min per week (IQR –10 to 120) compared with 30 min per week (–60 to 90) in the no incentive group (p=0·05). At 6 months, participants in the incentive group had
increased their moderate to vigorous physical activity by 30 min per week (–60 to 100) from baseline compared with 0 min per week (–115 to 1110) in the no incentive group (p=0·099). We noted no significant differences between groups
for use of loyalty card (p=0·18). Participants in the incentive group recorded a mean of 60·22 min (95% CI 50·90–69·55) of physical activity per week with their loyalty card on week 1 and 23·56 min (17·06–30·06) at week 12, which was similar to that for those in the no incentive group (59·74 min, 51·24–68·23, at week 1; 20·25 min, 14·45–26·06, at week 12; p=0·94 for differences between groups at week 1; p=0·45 for differences between groups at week 12).
Interpretation:
Financial incentives showed a short-term behaviour change in physical activity. This innovative study contributes to the necessary evidence base, and has important implications for physical activity promotion and business engagement in health. The optimum incentive-based approach needs to be established. Results should be interpreted with some caution as the analyses of secondary outcomes were not adjusted for multiple comparisons.
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Aims: Myocardial ischemia/reperfusion (I/R) is associated with mitochondrial dysfunction and subsequent cardiomyocyte death. The generation of excessive quantities of reactive oxygen species (ROS) and resultant damage to mitochondrial enzymes is considered an important mechanism underlying reperfusion injury. Mitochondrial complex I can exist in two interconvertible states: active (A) and deactive or dormant (D). We have studied the active/deactive (A/D) equilibrium in several tissues under ischemic conditions in vivo and investigated the sensitivity of both forms of the heart enzyme to ROS.
Results: We found that in the heart, t½ of complex I deactivation during ischemia was 10?min, and that reperfusion resulted in the return of A/D equilibrium to its initial level. The rate of superoxide generation by complex I was higher in ischemic samples where content of the D-form was higher. Only the D-form was susceptible to inhibition by H2O2 or superoxide, whereas turnover-dependent activation of the enzyme resulted in formation of the A-form, which was much less sensitive to ROS. The mitochondrial-encoded subunit ND3, most likely responsible for the sensitivity of the D-form to ROS, was identified by redox difference gel electrophoresis.
Innovation: A combined in vivo and biochemical approach suggests that sensitivity of the mitochondrial system to ROS during myocardial I/R can be significantly affected by the conformational state of complex I, which may therefore represent a new therapeutic target in this setting.
Conclusion: The presented data suggest that transition of complex I into the D-form in the absence of oxygen may represent a key event in promoting cardiac injury during I/R.
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The aim of this study is to investigate the stress experienced by full-time
maingrade lecturers as a result of changes in college organisation and factors that relate to stress. A questionnaire was constructed to identify possible sources of stress at work and the amount of stress experienced. Two psychometric measures were included—the General Health Questionnaire and the Maslach Burnout Inventory. The former looked at the physiological and psychological effects of stress and the latter, the emotive, cognitive and
behavioural effects, together referred to as 'burnout'. The study sought to investigate stress responses between lecturers employed in colleges that have undergone organisational change compared to those that have not. Two hundred questionnaires and psychometric measures were distributed, by opportunity, to 100 lecturers employed in FE colleges in the north of England and 100 employed in colleges in Northern Ireland. Colleges in the former region had undergone changes in college organisation as a result of incorporation. Colleges in the
latter had not. Incorporation referred to the process whereby colleges became independent of local government control. This led to a series of changes, some of which affected lecturers' terms and conditions. Overall, the indices of reported stress were comparable or markedly greater than earlier research findings, and the trend was for lecturers who had experienced organisational change to report higher measures of stress. GHQ measures showed a significant difference between samples, with the majority of the English sample (69.49%, compared to 40.91%) categorised as 'at risk' of developing symptoms associated with a
transient stress-related disorder, and whilst measures of 'burnout' were more pronounced in the English sample there were no significant differences between samples. In relation to a number of factors, the experience of stress and burnout was more pronounced in the Northern Ireland sample and explanations were offered, such as the influence of cultural variables and the increasing presence of stress-related features in these colleges as they move to incorporation.
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This short review establishes the conceptual bases and discusses the principal aspects of P4-shorthand for predictive, preventive, personalized and participatory medicine-medicine, in the framework of infectious diseases. P4 medicine is a new way to approach medical care; instead of acting when the patient is sick, physicians will be able to detect early warnings of disease to take early action. Furthermore, people might even be able to adjust their lifestyles to prevent disease. P4 medicine is fuelled by systems approaches to disease, including methods for personalized genome sequencing and new computational techniques for building dynamic disease predictive networks from massive amounts of data from a variety of OMICs. An excellent example of the effectiveness of the P4 medicine approach is the change in cancer treatments. Emphasis is placed on early detection, followed by genotyping of the patient to use the most adequate treatment according to the genetic background. Cardiovascular diseases and perhaps even neurodegenerative disorders will be the next targets for P4 medicine. The application of P4 medicine to infectious diseases is still in its infancy, but is a promising field that will provide much benefit to both the patients and the health-care system.
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PURPOSE: To describe fundus autofluorescence (AF) patterns and their change over time in patients with age-related macular degeneration (AMD) and high risk of visual loss participating in the drusen laser study (DLS). DESIGN: Randomized clinical trial. METHODS: The study population consisted of 29 patients (35 eyes) participating in the DLS, which is a prospective, randomized, controlled clinical trial of prophylactic laser therapy in patients with AMD and high risk of neovascular complications. The intervention consisted of 16 eyes having prophylactic laser and 19 receiving no treatment. The main outcome measures were changes in the distribution of drusen and AF. Patients were reviewed for a median follow-up or 24 months (range 12-36 months). RESULTS: At baseline, four patterns of fundus AF were recognized: focal increased AF (n = 18), reticular AF (n = 3), combined focal and reticular AF (n = 2), and homogeneous AF (n = 12). At last follow-up, fundus AF remained unchanged in 15 untreated (78%) and in seven treated (43%) eyes. In only one untreated eye, focal areas of increased AF returned to background levels and were no longer detectable at last follow-up, compared with six treated eyes. This difference was statistically significant (P = .03). Only large foveal soft drusen (drusenoid pigment epithelium detachments) consistently corresponded with focal changes in AF, whereas no obvious correspondence was found between small soft drusen located elsewhere and changes in AF. CONCLUSION: The lack of obvious correspondence between the distribution of drusen and of AF found in this study appears to indicate that drusen and AF represent independent measures of aging in the posterior pole. © 2002 Elsevier Science Inc. All rights reserved.
Resumo:
BACKGROUND: Open angle glaucoma (OAG) is a common cause of blindness.
OBJECTIVES: To assess the effects of medication compared with initial surgery in adults with OAG.
SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 7), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to August 2012), EMBASE (January 1980 to August 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to August 2012), Biosciences Information Service (BIOSIS) (January 1969 to August 2012), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (January 1937 to August 2012), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), Zetoc, the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 1 August 2012. The National Research Register (NRR) was last searched in 2007 after which the database was archived. We also checked the reference lists of articles and contacted researchers in the field.
SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing medications with surgery in adults with OAG.
DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. We contacted study authors for missing information.
MAIN RESULTS: Four trials involving 888 participants with previously untreated OAG were included. Surgery was Scheie's procedure in one trial and trabeculectomy in three trials. In three trials, primary medication was usually pilocarpine, in one trial it was a beta-blocker.The most recent trial included participants with on average mild OAG. At five years, the risk of progressive visual field loss, based on a three unit change of a composite visual field score, was not significantly different according to initial medication or initial trabeculectomy (odds ratio (OR) 0.74, 95% confidence interval (CI) 0.54 to 1.01). In an analysis based on mean difference (MD) as a single index of visual field loss, the between treatment group difference in MD was -0.20 decibel (dB) (95% CI -1.31 to 0.91). For a subgroup with more severe glaucoma (MD -10 dB), findings from an exploratory analysis suggest that initial trabeculectomy was associated with marginally less visual field loss at five years than initial medication, (mean difference 0.74 dB (95% CI -0.00 to 1.48). Initial trabeculectomy was associated with lower average intraocular pressure (IOP) (mean difference 2.20 mmHg (95% CI 1.63 to 2.77) but more eye symptoms than medication (P = 0.0053). Beyond five years, visual acuity did not differ according to initial treatment (OR 1.48, 95% CI 0.58 to 3.81).From three trials in more severe OAG, there is some evidence that medication was associated with more progressive visual field loss and 3 to 8 mmHg less IOP lowering than surgery. In the longer-term (two trials) the risk of failure of the randomised treatment was greater with medication than trabeculectomy (OR 3.90, 95% CI 1.60 to 9.53; hazard ratio (HR) 7.27, 95% CI 2.23 to 25.71). Medications and surgery have evolved since these trials were undertaken.In three trials the risk of developing cataract was higher with trabeculectomy (OR 2.69, 95% CI 1.64 to 4.42). Evidence from one trial suggests that, beyond five years, the risk of needing cataract surgery did not differ according to initial treatment policy (OR 0.63, 95% CI 0.15 to 2.62).Methodological weaknesses were identified in all the trials.
AUTHORS' CONCLUSIONS: Primary surgery lowers IOP more than primary medication but is associated with more eye discomfort. One trial suggests that visual field restriction at five years is not significantly different whether initial treatment is medication or trabeculectomy. There is some evidence from two small trials in more severe OAG, that initial medication (pilocarpine, now rarely used as first line medication) is associated with more glaucoma progression than surgery. Beyond five years, there is no evidence of a difference in the need for cataract surgery according to initial treatment.The clinical and cost-effectiveness of contemporary medication (prostaglandin analogues, alpha2-agonists and topical carbonic anhydrase inhibitors) compared with primary surgery is not known.Further RCTs of current medical treatments compared with surgery are required, particularly for people with severe glaucoma and in black ethnic groups. Outcomes should include those reported by patients. Economic evaluations are required to inform treatment policy.
Resumo:
BACKGROUND: To compare the ability of Glaucoma Progression Analysis (GPA) and Threshold Noiseless Trend (TNT) programs to detect visual-field deterioration.
METHODS: Patients with open-angle glaucoma followed for a minimum of 2 years and a minimum of seven reliable visual fields were included. Progression was assessed subjectively by four masked glaucoma experts, and compared with GPA and TNT results. Each case was judged to be stable, deteriorated or suspicious of deterioration
RESULTS: A total of 56 eyes of 42 patients were followed with a mean of 7.8 (SD 1.0) tests over an average of 5.5 (1.04) years. Interobserver agreement to detect progression was good (mean kappa = 0.57). Progression was detected in 10-19 eyes by the experts, in six by GPA and in 24 by TNT. Using the consensus expert opinion as the gold standard (four clinicians detected progression), the GPA sensitivity and specificity were 75% and 83%, respectively, while the TNT sensitivity and specificity was 100% and 77%, respectively.
CONCLUSION: TNT showed greater concordance with the experts than GPA in the detection of visual-field deterioration. GPA showed a high specificity but lower sensitivity, mainly detecting cases of high focality and pronounced mean defect slopes.
Resumo:
Purpose: This study was designed to evaluate the clinical agreement in the detection of optic disc changes and the ability of computerized image analysis to detect glaucomatous deterioration of the optic disc. Methods: Pairs of stereophotographs of 35 glaucomatous optic discs taken 5 years apart and of 5 glaucomatous discs photographed twice on the same day. Two glaucoma specialists examined the pairs of stereophotographs (35 cases and 5 controls) in a masked manner and judged whether the optic disc showed changes in the optic disc compatible with progression of glaucomatous damage. The stereophotographs of the five optic discs photographed twice on the same day (which by definition did not change) and of five cases judged to have deteriorated by both glaucoma specialists were analyzed by computerized image analysis with the Topcon ImageNet system. Intra- and inter-observer agreement in the detection of optic disc changes (evaluated using kappa statistic), and changes in the rim area to disc area ratio (evaluated using descriptive statistics and paired t-test). Results: Intra-observer agreement had a kappa value of 0.75 for observer 1 and 0.60 for the observer 2. Inter-observer agreement between the glaucoma specialists had a kappa value of 0.60. The image analyzer did not discriminate between controls and cases with clinically apparent glaucomatous change of the optic disc. Conclusion: Clinical agreement in detecting changes in the optic disc was moderate to substantial. Computerized image analysis with the Topcon ImageNet system appeared not to be useful in detecting glaucomatous changes of the optic disc.
Resumo:
Background: Financial incentives have been advocated by the UK and U.S. governments to encourage adoption of healthy lifestyles. However, evidence to support the use of incentives for changing physical activity (PA) behavior is sparse.
Purpose:To investigate the effectiveness of?nancial incentives to increase PA in adults in the workplace.
Design: Two-arm quasi-experimental design.
Setting/participants: Employees (n¼406) in a workplace setting in Belfast, Northern Ireland, UK.
Intervention: Using a loyalty card to collect points and earn rewards, participants (n¼199) in the Incentive Group monitored their PA levels and received ?nancial incentives (retail vouchers) for minutes of PA completed over the course of a 12-week intervention period. Participants (n¼207) in the comparison group used their loyalty card to self-monitor their PA levels but were not able to earn points or obtain incentives (No Incentive Group).
Main outcome measures:The primary outcome was minutes of PA objectively measured using a novel PA tracking system at baseline (April 2011); Week 6 (June 2011); and Week 12 (July 2011).
Other outcomes, including a self-report measure of PA, were collected at baseline, Week 12, and 6 months (October 2011). Data were analyzed in June 2012.
Results: No signi?cant differences between groups were found for primary or secondary outcomes at the 12-week and 6-month assessments. Participants in the Incentive Group recorded 17.52 minutes of PA/week (95% CI¼12.49, 22.56) compared to 16.63 minutes/week (95% CI¼11.76, 21.51) in the No Incentive Group at Week 12 (p¼0.59). At 6 months, participants in the Incentive Group recorded 26.18 minutes of PA/week (95% CI¼20.06, 32.29) compared to 24.00 minutes/week (95% CI¼17.45, 30.54) in the No Incentive Group (p¼0.45).
Conclusions: Financial incentives did not encourage participants to undertake more PA than selfmonitoring PA. This study contributes to the evidence base and has important implications for increasing participation in physical activity and fostering links with the business sector. (Am J Prev Med 2013;45(1):56–63) © 2013 American Journal of Preventive Medicine
Resumo:
Protein-protein interactions play a central role in many cellular processes. Their characterisation is necessary in order to analyse these processes and for the functional identification of unknown proteins. Existing detection methods such as the yeast two-hybrid (Y2H) and tandem affinity purification (TAP) method provide a means to answer rapidly questions regarding protein-protein interactions, but have limitations which restrict their use to certain interaction networks; furthermore they provide little information regarding interaction localisation at the subcellular level. The development of protein-fragment complementation assays (PCA) employing a fluorescent reporter such as a member of the green fluorescent protein (GFP) family has led to a new method of interaction detection termed Bimolecular Fluorescent Complementation (BiFC). These assays have become important tools for understanding protein interactions and the development of whole genome interaction maps. BiFC assays have the advantages of very low background signal coupled with rapid detection of protein-protein interactions in vivo while also providing information regarding interaction compartmentalisation. Modified forms of the assay such as the use of combinations of spectral variants of GFP have allowed simultaneous visualisation of multiple competing interactions in vivo. Advantages and disadvantages of the method are discussed in the context of other fluorescence-based interaction monitoring techniques.
Resumo:
Background: The aim of this study was to assess the efficacy, tolerability and safety of risedronate in adults with CF. Methods: Patients with a lumbar spine (LS), total hip (TH) or femoral neck (FN) bone mineral density (BMD) Z-score of -1 or less were randomised to receive risedronate 35mg weekly or placebo, and calcium (1g)+vitamin D (800IU). Results: At baseline, BMD Z-scores in the risedronate (n = 17) and placebo (n = 19) groups were similar. By 24. months, 7/17 risedronate patients vs 0/19 placebo patients stopped the study medication due to bone pain. After 24. months treatment, the mean difference (95% CI) in change in LS, TH and FN BMD between the risedronate vs placebo groups was 4.3% (0.4, 8.2) p = 0.03; 4.0% (-0.5, 8.6) p = 0.08; and 2.4% (-3.5, 8.2) p =0.41. Conclusions: After two years treatment there was a significant increase in LS BMD with weekly risedronate compared to placebo. © 2011 European Cystic Fibrosis Society.
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Abstract:
Background: Health care organisations
worldwide are faced with the need to develop
and implement strategic organisational plans
to meet the challenges of modern health care.
There is a need for models for developing, implementing and evaluating strategic plans that engage practitioners, and make a measurable difference to the patients that they serve. These presentations describe the development, implementation and evaluation of such a model by a team of senior nurses and practice developers, to underpin a strategy for nursing and midwifery in an acute hospital trust. Developing a Strategy The PARIHS (Promoting Action on Research Implementation in Health Services) conceptual framework (Kitson et al, 1998) proposes that successful implementation of change in practice is a function of the interplay of three core elements: the level of evidence supporting the proposed change; the context or environment in which the change takes place, and the way in which change is facilitated. We chose to draw on this framework to develop our strategy and implementation plan (O’Halloran, Martin and Connolly, 2005). At the centre of the plan are ward managers. These professionals provide leadership for the majority of staff in the trust and so were seen to be a key group in the implementation process.
Resumo:
This paper considers the enhancement of loss-of-mains detection by use of a differential rate-of-change-of-frequency relay to reduce nuisance tripping and improve sensitivity to small excursions in frequency. The telecommunications media which might carry the differential ROCOF signal are reviewed with a focus on channel latency, bandwidth and security.