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PURPOSE: 1. To describe the motor learning outcomes of wheelchair propulsion across 6 weeks of clinical spinal cord injury (SCI) rehabilitation 2. To compare those outcomes between persons at discharge from clinical rehabilitation and experienced community-dwelling wheelchairs users. METHODS: 8 Individuals with a recent SCI performed a submaximal exercise test once-weekly across 6 weeks, starting at the beginning of active rehabilitation. Energy consumption and propulsion kinetics were recorded. In the first and the last week of the 6-week period, participants performed a peak graded exercise test and a 10-item wheelchair skill circuit. 15 experienced individuals with a SCI performed all above-mentioned tests on one occasion. RESULTS: Mechanical efficiency (ME) (6.4->6.2%, p=0.23) and propulsion technique (push frequency 58->56 push/min, p=0.84; contact angle 71->74°, p=0.712; positive work per push 8.3->8.9 J, p=0.30) did not change during the first 6 weeks of active SCI rehabilitation. Peak power output increased (38 W -> 45 W, p=0.01) between the first and the last week. Performance time on wheelchair circuit improved (18.4 -> 16.6 s, p=0.01) and ability score showed a borderline increase (8.4->8.9, p=0.09). No difference in propulsion technique was found between the recent SCI at discharge and experienced group (respectively, push frequency 56 vs. 50 push/min, p=0.57; contact angle 74 vs 78°, p=0.57; positive work 8.9 vs 9.6 J, p=0.65). ME was higher in the recent SCI group (6.1 vs 5.1%, p=0.03). Peak power output (45 vs 59 W, p=0.11), ability score (8.9 vs 9.6, p=0.06) and performance time did not differ between the groups (16.6 vs 15.3 s, p=0.12). CONCLUSION: Recent SCI group did not improve ME and propulsion technique across 6 weeks of active rehabilitation but exhibited an improvement in the peak capacity and wheelchair skill. Between groups comparison provided surprising results as the only significant difference showed higher ME in the recent SCI group.

Study Design Cross-sectional study.Objectives To describe experienced sitting-related health and stability problems among persons with paraplegia (PP) or tetraplegia (TP) and to investigate associations with personal, lesion and wheelchair characteristics as well as satisfaction with sitting posture.Setting Dutch community.Methods A self-report questionnaire on seating was developed and completed by wheelchair-users living with Spinal Cord Injury (SCI) for >= 10 years (N= 264). Sitting-related problems and satisfaction with sitting posture were compared between participants with PP and TP using Chi-square and t-tests. Logistic regression analyses were performed to investigate associated characteristics.Results Reported sitting-related problems comprised: sitting to be tiring (regularly to always) (33%), sitting to be painful (28%), pressure ulcers in the last three months (29%), instability while sitting (8%) and instability during reaching (33%). Except for instability during reaching, no differences in occurrence of sitting-problems were found between lesion-group. Persons with TP were more dissatisfied with their sitting posture than persons with PP: 51% vs 36% (p = 0.022) and 51% and 47% respectively thought their sitting posture could be improved (p = 0 .670) . 'Experienced lack of support in the wheelchair' was associated with most sitting-problems. Pain and instability were associated with dissatisfaction with sitting posture.Conclusion Sitting-related problems and dissatisfaction with sitting posture were frequently reported by persons with long-standing SCI. Sitting problems appeared to associate with lacking support in the wheelchair/seating. A comprehensive feedback from the wheelchair user and a stability check (reach task), as part of the wheelchair/seating-user fitting, may contribute to prevention of sitting-related problems.

Study design: Cross-sectional surveyObjectives: To describe computer and Internet use (other than for work or study) among people with long-standing spinal cord injury (SCI), examine associations between demographic and lesion characteristics and Internet use, and examine associations between Internet use and mental health, participation, and life satisfaction.Setting: Community, The NetherlandsMethods: Participants were 265 individuals living with SCI for at least 10 years, who were 18-35 at the onset of SCI, aged 28-65 at the time of the study and wheelchair-user. Scales for General and Health-related Internet use were developed.Results: Nearly all (97.7%) participants had Internet access and 98.4% of those used it daily or weekly. Of those with tetraplegia, 47.4% had assistive devices for computer use. General Internet use, such as following news and online banking, was very frequent. Websites with information on general health or accessibility were typically visited a few times a year. Three-quarters never visited websites of other individuals with SCI or foreign websites with information on SCI. General Internet use was associated with male gender, younger age, and higher education. Participants with tetraplegia scored higher on Health-related Internet use compared to participants with paraplegia. Health-related Internet use was associated with worse participation, but not with the other psychosocial variables.Conclusion: Internet has become part of daily life of people with SCI in the Netherlands. However, only one association between Internet use and indicators of psychosocial functioning was found. Possible underuse of adaptive devices and of SCI-specific websites warrant further investigation.

Objectives: To study disability-management self-efficacy (DMSE) and its correlates in a large sample of Dutch people with long-standing spinal cord injury (SCI). DMSE is the confidence that people with SCI may have in their ability to manage the consequences of their condition with respect to the various domains in their life. Research questions were: (1) What is the level of DMSE in Dutch people with long-standing SCI?; (2) Is DMSE associated with demographic and lesion characteristics?; and (3) Is DMSE associated with participation and life satisfaction if these associations are adjusted for demographic and lesion characteristics and mood?Methods: Eligible people were identified from all eight rehabilitation centers with a specialty in SCI rehabilitation in the Netherlands (N=261). Data were collected using a self-report questionnaire. DMSE was measured using the University of Washington Self-Efficacy Scale-Short Form (UW-SES-6). Correlation and linear regression analyses were used.Results: Levels of UW-SES-6 scores were largely independent of demographic and lesion characteristics. UW-SES-6 scores were bivariately moderately to strongly associated with mood (0.47), participation (0.39-0.51) and life satisfaction (0.46). In the regression analyses, UW-SES-6 scores still explained a significant amount of variance of participation (standardized beta 0.31-0.33) and life satisfaction (standardized beta 0.21) when controlling for demographic and lesion characteristics and mood, and explained an additional 3.2-8.1% of the variance of participation and life satisfaction.Conclusion: DMSE is a psychological resource associated with higher levels of participation and life satisfaction after SCI. The UW-SES-6 is a brief and easy to use measure of this psychological resource.

Within a period of six months, three men were admitted following falls which had occurred more than one week previously. They had all sustained minor trauma but directly after the injury they were unable to bear weight on the affected limb. All three had Grade 1 posterior dislocations of the hip. Although the dislocation had occurred more than one week previously, closed reduction under spinal anaesthesia was successful in each case. After reduction, the patients were put on traction for two weeks and then continued with partial weight-bearing for four weeks. Immediately after reduction physiotherapy was started. Following treatment, all three patients walked without complaint. We concluded that a neglected posterior dislocation of the hip can be treated in a rural district hospital, with a trial of closed reduction under spinal anaesthesia. Successful reduction is essential to prevent further severe disability, after which further management can be discussed.Key words: hip, dislocation, neglected, developing countries

Objective The objective of this study was to investigate the effects of a low-intensity wheelchair training on propulsion technique in inactive people with long-term spinal cord injury. Design Participants in this multicenter nonblinded randomized controlled trial were inactive manual wheelchair users with spinal cord injury for at least 10 yrs (N = 29), allocated to exercise (n = 14) or no exercise. The 16-wk training consisted of wheelchair treadmill propulsion at 30%-40% heart rate reserve or equivalent in rate of perceived exertion, twice a week, 30 mins per session. Propulsion technique was assessed at baseline as well as after 8, 16, and 42 wks during two submaximal treadmill-exercise blocks using a measurement wheel attached to a participant's own wheelchair. Changes over time between the groups were analyzed using Mann-Whitney U tests on difference scores (P < 0.05/3). Results Data of 16 participants could be analyzed (exercise: n = 8). Significant differences between the exercise and control groups were only found in peak force after 8 wks (respective medians, -20 N vs. 1 N; P = 0.01; r

Objectives: To describe wheelchair-specific anaerobic work capacity, isometric strength and peak aerobic work capacity of physically inactive people with long-term spinal cord injury using outcomes of tests that are feasible for use in rehabilitation centres, and to determine associations among these fitness components. Design: Cross-sectional study. Participants: Manual wheelchair users with spinal cord injury for at least 10 years, who were inactive based on a norm score of a physical activity questionnaire (n?=?29; 22 men; 20 with paraplegia; median age 53 years). Methods: Participants performed 3 exercise tests in their own wheelchair to determine: highest 5-s power output over 15-m overground sprinting (P5–15m); highest 3-s isometric push-force (Fiso); and peak power output (POpeak) and peak oxygen uptake (VO2peak) over a peak test. Results: Median (interquartile range) was in P5–15m 16.1 W (9.4–20.9); in Fiso 399 N (284–610); in POpeak 40.9 W (19.1–54.9); and in VO2peak 1.26 l/min (0.80–1.67). Correlations among outcomes of fitness components were weak (r?=?0.50–0.67, p?0.01), except for P5–15m with POpeak (r?=?0.79, p?

OBJECTIVE:To assess the incidence and risk factors for acute hepatitis B and acute hepatitis C in a defined Canadian population.PATIENTS AND METHODS:An enhanced surveillance system was established in October 1998 to identify cases of acute hepatitis B and C infections in four regions in Canada, with a total population of approximately 3.2 million people. Information on demographic and clinical characteristics, laboratory results and potential risk factors was collected using predefined questionnaires.RESULTS:A total of 79 cases of acute hepatitis B and 102 cases of acute hepatitis C were identified from October 1998 to December 1999, resulting in an incidence rate of 2.3 and 2.9/100,000 person-years, respectively. Males had higher incidence rates than females. The incidence of acute hepatitis B peaked at age 30 to 39 years for both males and females, whereas acute hepatitis C peaked at 30 to 39 years for males and 15 to 29 years for females. At least 34% of acute hepatitis B and 63% of acute hepatitis C were associated with injection drug use. Persons who were 15 to 39 years of age were more likely to report injection drug use as a risk factor. Heterosexual contact was reported to be a risk factor for 36.6% of acute hepatitis B cases and 3.5% of acute hepatitis C cases.CONCLUSIONS:The surveillance provides national incidence estimates of clinically recognized acute hepatitis B and C. Both hepatitis B and C are important public health threats to Canadians. Prevention efforts for both diseases should focus on injection drug use, especially for people aged 15 to 39 years. Risky sexual behaviour is also a major concern in prevention of hepatitis B in Canada.

Aims The presence of Epstein–Barr virus (EBV) was studied in 56 gastric carcinomas from Western patients by in-situ hybridization for EBV-encoded RNAs (EBER). EBV-positive and negative carcinomas were compared for various pathological parameters including p53 overexpression. Methods and results EBERs transcripts were detected in seven cases overall: four cases of 52 conventional carcinomas (7.7%) and three cases of four gastric carcinomas with lymphoid stroma (75%). EBER positivity was diffuse in five cases and restricted to a localized area of the tumour in two cases of conventional carcinoma. A monoclonal EBV genomic pattern was demonstrated in the case tested by Southern blot analysis. By immunohistochemical analysis, neither EBV latent or lytic cycle proteins nor C3d/EBV receptor were expressed by neoplastic cells. EBER positivity was significantly correlated with prominent lymphoid reaction (P = 0.0002) which was associated with numerous PS100-positive dendritic cells and with HLA-DR expression by tumour cells (P = 0.03). p53 immunoreactivity in more than 30% of tumour cells was detected in 25 out 49 EBV-negative cases and was absent in EBV-positive cases except in one case with focal EBER-positivity. Conclusions Focal staining for EBER is an unusual finding in the setting of gastric carcinoma and these results suggest that there might be two types of EBV-associated gastric carcinoma in which the viral infection will play a different role. The presence of a stromal lymphoid reaction which is strongly correlated with EBV positivity, is associated with antigen-presenting ability by HLA-DR-positive tumour cells or abundant dendritic cells. The function of p53 appears preserved in all EBV-associated carcinomas except in one case with focal EBER expression whereas the immunohistochemical pattern of p53 is suggestive of a mutational phenomenon in 51% of EBV-negative cases.

To assess the risk of hepatitis C in Canada and to predict the burden that this disease may pose to the Canadian society in the near future, expected numbers of persons at different stages of the disease currently and in the next decade were estimated by simulation using a published hepatitis C natural history model with no treatment effect being applied. Based on the estimate of 240,000 persons who are currently infected with the hepatitis C virus in Canada, the simulation analysis demonstrated that the number of hepatitis C cirrhosis cases would likely increase by 92% from 1998 to the year 2008. It was also projected that the number of liver failures and hepatocellular carcinomas related to hepatitis C would increase by 126% and 102%, respectively, in the next decade. The number of liver-related deaths associated with hepatitis C is expected to increase by 126% in 10 years. The medical and social care systems in Canada may not be ready to support these large increases. These results highlight the importance of both the control of disease progression of hepatitis C virus-infected persons and the primary prevention of hepatitis C infections in Canada.

In this work we propose a new method for face recognition that successfully handles occluded faces. We propose an innovative improvement that allows to detect and discard occluded zones of the face, thus making recognition more robust in the presence of occlusion. We provide experimental results that show that the proposed method performs well in practice. © 2012 Springer-Verlag. Fil:Morelli Andres, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Tepper, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Mejail, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

Computing the minimum spanning tree (MST) is a common task in the pattern recognition and the computer vision fields. However, little work has been done on efficient general methods for solving the problem on large datasets where graphs are complete and edge weights are given implicitly by a distance between vertex attributes. In this work we propose a generic algorithm that extends the classical Boruvka's algorithm by using nearest neighbors search structures to reduce significantly time and memory performances. The algorithm can also compute in a straightforward way approximate MSTs thus further improving speed. Experiments show that the proposed method outperforms classical algorithms on large low-dimensional datasets by several orders of magnitude. Finally, to illustrate the usefulness of the proposed algorithm, we focus on a classical computer vision problem: image segmentation. We modify a state-of-the-art local graph-based clustering algorithm, thus permitting a global scene analysis.

This paper addresses a license plate detection and recognition (LPR) task on still images of trucks. The main contribution of our LPR system is the fusion of different segmentation algorithms used to improve the license plate detection. We also compare the performance of two kinds of classifiers for optical character recognition (OCR): one based on the a contrario framework using the shape contexts as features and the other based on a SVM classifier using the intensity pixel values as features. © 2010 Springer-Verlag. Fil:Tepper, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Acevedo, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Mejail, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

OBJECTIVES: We sought to assess whether statins may decrease cardiac complications in patients undergoing noncardiac vascular surgery. BACKGROUND: Cardiovascular complications account for considerable morbidity in patients undergoing noncardiac surgery. Statins decrease cardiac morbidity and mortality in patients with coronary disease, and the beneficial treatment effect is seen early, before any measurable increase in coronary artery diameter. METHODS: A retrospective study recorded patient characteristics, past medical history, and admission medications on all patients undergoing carotid endarterectomy, aortic surgery, or lower extremity revascularization over a two-year period (January 1999 to December 2000) at a tertiary referral center. Recorded perioperative complication outcomes included death, myocardial infarction, ischemia, congestive heart failure, and ventricular tachyarrhythmias occurring during the index hospitalization. Univariate and multivariate logistic regressions identified predictors of perioperative cardiac complications and medications that might confer a protective effect. RESULTS: Complications occurred in 157 of 1,163 eligible hospitalizations and were significantly fewer in patients receiving statins (9.9%) than in those not receiving statins (16.5%, p = 0.001). The difference was mostly accounted by myocardial ischemia and congestive heart failure. After adjusting for other significant predictors of perioperative complications (age, gender, type of surgery, emergent surgery, left ventricular dysfunction, and diabetes mellitus), statins still conferred a highly significant protective effect (odds ratio 0.52, p = 0.001). The protective effect was similar across diverse patient subgroups and persisted after accounting for the likelihood of patients to have hypercholesterolemia by considering their propensity to use statins. CONCLUSIONS: Use of statins was highly protective against perioperative cardiac complications in patients undergoing vascular surgery in this retrospective study. J Am Coll Cardiol