1,460 research outputs found
What were we all looking at? Identifying objects of collective visual attention
The file attached to this record is the authors final peer reviewed version. The publisher's final version can be found by following the DOI link below.We aim to identify the salient objects in an image by applying a model of visual attention. We automate the process by predicting those objects in an image that are most likely to be the focus of someone’s visual attention. Concretely, we first generate fixation maps from the eye tracking data, which express the ground truth of people’s visual attention for each training image. Then, we extract the high-level features based on the bag-of-visual-words image representation as input attributes along with the fixation maps to train a support vector regression model. With this model, we can predict a new query image’s saliency. Our experiments show that the model is capable of providing a good estimate for human visual attention in test images sets with one salient object and multiple salient objects. In this way, we seek to reduce the redundant information within the scene, and thus provide a more accurate depiction of the scene
Feasibility study of a clinically-integrated randomized trial of modifications to radical prostatectomy
<p>Abstract</p> <p>Background</p> <p>Numerous technical modifications to radical prostatectomy have been proposed. Such modifications are likely to lead to only slight improvements in outcomes. Although small differences would be worthwhile, an appropriately powered randomized trial would need to be very large, and thus of doubtful feasibility given the expense, complexity and regulatory burden of contemporary clinical trials. We have proposed a novel methodology, the clinically-integrated randomized trial, which dramatically streamlines trial procedures in order to reduce the marginal cost of an additional patient towards zero. We aimed to determine the feasibility of implementing such a trial for radical prostatectomy.</p> <p>Methods</p> <p>Patients undergoing radical prostatectomy as initial treatment for prostate cancer were randomized in a factorial design to involvement of the fascia during placement of the anastomotic sutures, urethral irrigation, both or neither. Endpoint data were obtained from routine clinical documentation. Accrual and compliance rates were monitored to determine the feasibility of the trial.</p> <p>Results</p> <p>From a total of 260 eligible patients, 154 (59%) consented; 56 patients declined to participate, 20 were not approached on recommendation of the treating surgeon, and 30 were not approached for logistical reasons. Although recording by surgeons of the procedure used was incomplete (~80%), compliance with randomization was excellent when it was recorded, with only 6% of procedures inconsistent with allocation. Outcomes data was received from 71% of patients at one year. This improved to 83% as the trial progressed.</p> <p>Conclusions</p> <p>A clinically-integrated randomized trial was conducted at low cost, with excellent accrual, and acceptable compliance with treatment allocation and outcomes reporting. This demonstrates the feasibility of the methodology. Improved methods to ensure documentation of surgical procedures would be required before wider implementation.</p> <p>Trial registration</p> <p>ClinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT00928850">NCT00928850</a></p
A four-kallikrein panel for the prediction of repeat prostate biopsy: data from the European Randomized Study of Prostate Cancer Screening in Rotterdam, Netherlands
Background: Most men with elevated levels of prostate-specific antigen (PSA) do not have prostate cancer, leading to a large number of unnecessary biopsies. A statistical model based on a panel of four kallikreins has been shown to predict the outcome of a first prostate biopsy. In this study, we apply the model to an independent data set of men with previous negative biopsy but persistently elevated PSA. Methods: The study cohort consisted of 925 men with a previous negative prostate biopsy and elevated PSA (≥3 ng ml-1), with 110 prostate cancers detected (12%). A previously published statistical model was applied, with recalibration to reflect the lower positive biopsy rates on rebiopsy. Results: The full-kallikrein panel had higher discriminative accuracy than PSA and DRE alone, with area under the curve (AUC) improving from 0.58 (95% confidence interval (CI): 0.52, 0.64) to 0.68 (95% CI: 0.62, 0.74), P<0.001, and high-grade cancer (Gleason 7) at biopsy with AUC improving from 0.76 (95% CI: 0.64, 0.89) to 0.87 (95% CI: 0.81, 0.94), P<0.003). Application of the panel to 1000 men with persistently elevated PSA after initial negative biopsy, at a 15% risk threshold would reduce the number of biopsies by 712; would miss (or delay) the diagnosis of 53 cancers, of which only 3 would be Gleason 7 and the rest Gleason 6 or less. Conclusions: Our data constitute an external validation of a previously published model. The four-kallikrein panel predicts the result of repeat prostate biopsy in men with elevated PSA while dramatically decreasing unnecessary biopsies
The methodological and reporting quality of systematic reviews from China and the USA are similar
Objective: To compare the methodological and reporting quality of systematic reviews by authors from China and those from the United States (the USA). Study Design: From systematic reviews of randomised trials published in 2014 in English, we randomly selected 100 from China and 100 from the USA. The methodological quality was assessed using the AMSTAR tool, and reporting quality assessed using the PRISMA tool. Results: Compared with systematic reviews from the USA, those from China were more likely to be a meta-analysis, published in low impact journals, and a non-Cochrane review. The mean summary AMSTAR score was 6.7 (95% confidence interval: 6.5 to 7.0) for reviews from China and 6.6 (6.1 to 7.1) for reviews from the USA, and the mean summary PRISMA score was 21.2 (20.7 to 21.6) for reviews from China and 20.6 (19.9 to 21.3) for reviews from the USA. The differences in summary quality scores between China and the USA were statistically non-significant after adjusting for multiple review factors. Conclusions: The overall methodological and reporting quality of systematic reviews by authors from China are similar to those from the USA, although the quality of systematic reviews from both countries could be further improved
Rare germline variants in DNA repair genes and the angiogenesis pathway predispose prostate cancer patients to develop metastatic disease
Background
Prostate cancer (PrCa) demonstrates a heterogeneous clinical presentation ranging from largely indolent to lethal. We sought to identify a signature of rare inherited variants that distinguishes between these two extreme phenotypes.
Methods
We sequenced germline whole exomes from 139 aggressive (metastatic, age of diagnosis < 60) and 141 non-aggressive (low clinical grade, age of diagnosis ≥60) PrCa cases. We conducted rare variant association analyses at gene and gene set levels using SKAT and Bayesian risk index techniques. GO term enrichment analysis was performed for genes with the highest differential burden of rare disruptive variants.
Results
Protein truncating variants (PTVs) in specific DNA repair genes were significantly overrepresented among patients with the aggressive phenotype, with BRCA2, ATM and NBN the most frequently mutated genes. Differential burden of rare variants was identified between metastatic and non-aggressive cases for several genes implicated in angiogenesis, conferring both deleterious and protective effects.
Conclusions
Inherited PTVs in several DNA repair genes distinguish aggressive from non-aggressive PrCa cases. Furthermore, inherited variants in genes with roles in angiogenesis may be potential predictors for risk of metastases. If validated in a larger dataset, these findings have potential for future clinical application
The BDNF Val66Met polymorphism moderates the relationship between Posttraumatic Stress Disorder and fear extinction learning
The low expression Met allele of the BDNF Val66Met polymorphism is associated with impaired fear extinction in healthy controls, and poorer response to exposure therapy in patients with Posttraumatic Stress Disorder (PTSD). Given that fear extinction underlies exposure therapy, this raises the question of the impact of BDNFVal66Met polymorphism on fear extinction in PTSD, yet this question has not yet been examined. One hundred and six participants (22 PTSD, 46 trauma-exposed controls (TC) and 38 non-trauma exposed controls (NTC)) completed a fear conditioning and extinction task and saliva samples were taken for DNA extraction and genotyped for the BDNF Val66Met polymorphism. Moderation analyses using PROCESS examined whether BDNF genotype (Val–Val vs Met carriers) moderated the relationship between PTSD symptom severity (and diagnostic status) and skin conductance response (SCR) amplitude during fear extinction. The PTSD group displayed significantly slower fear extinction learning compared to TC and NTC in the early extinction phase. The BDNF Val66Met polymorphism moderated the relationship between PTSD and fear extinction learning, such that poorer fear extinction learning was associated with greater PTSD symptom severity (and PTSD diagnostic status) in individuals with the low-expression Met allele, but no relationship was demonstrated in individuals with the Val–Val allele. This study reveals that impaired fear extinction learning is particularly evident in individuals with PTSD who carry the low-expression BDNF Met Val–Val allele and importantly not in those with the allele. This provides novel evidence of a link between BDNF and impaired fear extinction learning in PTSD, which may contribute to poorer response to exposure therapy
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