University of Pittsburgh

About: University of Pittsburgh is a education organization based out in Pittsburgh, Pennsylvania, United States. It is known for research contribution in the topics: Population & Transplantation. The organization has 87042 authors who have published 201012 publications receiving 9656783 citations. The organization is also known as: Pitt & Western University of Pennsylvania.

Clinical Correlates of White Matter Findings on Cranial Magnetic Resonance Imaging of 3301 Elderly People: The Cardiovascular Health Study

Abstract: Background and Purpose Our aim was to identify potential risk factors for and clinical manifestations of white matter findings on cranial MRI in elderly people. Methods Medicare eligibility lists were used to obtain a representative sample of 5888 community-dwelling people aged 65 years or older. Correlates of white matter findings were sought among 3301 participants who underwent MRI scanning and denied a history of stroke or transient ischemic attack. Participants underwent extensive standardized evaluations at baseline and on follow-up, including standard questionnaires, physical examination, multiple blood tests, electrocardiogram, pulmonary function tests, carotid sonography, and M-mode echocardiography. Neuroradiologists graded white matter findings from 0 (none) to 9 (maximal) without clinical information. Results Many potential risk factors were related to the white matter grade, but in the multivariate model the factors significantly (all P<.01) and independently associated with increased grade w...

Learning from class-imbalanced data

Abstract: 527 articles related to imbalanced data and rare events are reviewed.Viewing reviewed papers from both technical and practical perspectives.Summarizing existing methods and corresponding statistics by a new taxonomy idea.Categorizing 162 application papers into 13 domains and giving introduction.Some opening questions are discussed at the end of this manuscript. Rare events, especially those that could potentially negatively impact society, often require humans decision-making responses. Detecting rare events can be viewed as a prediction task in data mining and machine learning communities. As these events are rarely observed in daily life, the prediction task suffers from a lack of balanced data. In this paper, we provide an in depth review of rare event detection from an imbalanced learning perspective. Five hundred and seventeen related papers that have been published in the past decade were collected for the study. The initial statistics suggested that rare events detection and imbalanced learning are concerned across a wide range of research areas from management science to engineering. We reviewed all collected papers from both a technical and a practical point of view. Modeling methods discussed include techniques such as data preprocessing, classification algorithms and model evaluation. For applications, we first provide a comprehensive taxonomy of the existing application domains of imbalanced learning, and then we detail the applications for each category. Finally, some suggestions from the reviewed papers are incorporated with our experiences and judgments to offer further research directions for the imbalanced learning and rare event detection fields.

American College of Rheumatology 2008 Recommendations for the Use of Nonbiologic and Biologic Disease-Modifying Antirheumatic Drugs in Rheumatoid Arthritis

Abstract: Guidelines and recommendations developed and/or endorsed by the American College of Rheumatology (ACR) are intended to provide guidance for particular patterns of practice and not to dictate the care of a particular patient. The ACR considers adherence to these guidelines and recommendations to be voluntary, with the ultimate determination regarding their application to be made by the physician in light of each patient’s individual circumstances. Guidelines and recommendations are intended to promote beneficial or desirable outcomes but cannot guarantee any specific outcome. Guidelines and recommendations developed or endorsed by the ACR are subject to periodic revision as warranted by the evolution of medical knowledge, technology, and practice.

Sentinel-lymph-node resection compared with conventional axillary-lymph-node dissection in clinically node-negative patients with breast cancer: overall survival findings from the NSABP B-32 randomised phase 3 trial

Abstract: Summary Background Sentinel-lymph-node (SLN) surgery was designed to minimise the side-effects of lymph-node surgery but still offer outcomes equivalent to axillary-lymph-node dissection (ALND). The aims of National Surgical Adjuvant Breast and Bowel Project (NSABP) trial B-32 were to establish whether SLN resection in patients with breast cancer achieves the same survival and regional control as ALND, but with fewer side-effects. Methods NSABP B-32 was a randomised controlled phase 3 trial done at 80 centres in Canada and the USA between May 1, 1999, and Feb 29, 2004. Women with invasive breast cancer were randomly assigned to either SLN resection plus ALND (group 1) or to SLN resection alone with ALND only if the SLNs were positive (group 2). Random assignment was done at the NSABP Biostatistical Center (Pittsburgh, PA, USA) with a biased coin minimisation approach in an allocation ratio of 1:1. Stratification variables were age at entry (≤49 years, ≥50 years), clinical tumour size (≤2·0 cm, 2·1–4·0 cm, ≥4·1 cm), and surgical plan (lumpectomy, mastectomy). SLN resection was done with a blue dye and radioactive tracer. Outcome analyses were done in patients who were assessed as having pathologically negative sentinel nodes and for whom follow-up data were available. The primary endpoint was overall survival. Analyses were done on an intention-to-treat basis. All deaths, irrespective of cause, were included. The mean time on study for the SLN-negative patients with follow-up information was 95·6 months (range 70·1–126·7). This study is registered with ClinicalTrials.gov, number NCT00003830. Findings 5611 women were randomly assigned to the treatment groups, 3989 had pathologically negative SLN. 309 deaths were reported in the 3986 SLN-negative patients with follow-up information: 140 of 1975 patients in group 1 and 169 of 2011 in group 2. Log-rank comparison of overall survival in groups 1 and 2 yielded an unadjusted hazard ratio (HR) of 1·20 (95% CI 0·96–1·50; p=0·12). 8-year Kaplan-Meier estimates for overall survival were 91·8% (95% CI 90·4–93·3) in group 1 and 90·3% (88·8–91·8) in group 2. Treatment comparisons for disease-free survival yielded an unadjusted HR of 1·05 (95% CI 0·90–1·22; p=0·54). 8-year Kaplan-Meier estimates for disease-free survival were 82·4% (80·5–84·4) in group 1 and 81·5% (79·6–83·4) in group 2. There were eight regional-node recurrences as first events in group 1 and 14 in group 2 (p=0·22). Patients are continuing follow-up for longer-term assessment of survival and regional control. The most common adverse events were allergic reactions, mostly related to the administration of the blue dye. Interpretation Overall survival, disease-free survival, and regional control were statistically equivalent between groups. When the SLN is negative, SLN surgery alone with no further ALND is an appropriate, safe, and effective therapy for breast cancer patients with clinically negative lymph nodes. Funding US Public Health Service, National Cancer Institute, and Department of Health and Human Services.

Synaptic Modification by Correlated Activity: Hebb's Postulate Revisited

Abstract: ■ Abstract Correlated spiking of pre- and postsynaptic neurons can result in strengthening or weakening of synapses, depending on the temporal order of spiking. Recent findings indicate that there are narrow and cell type‐specific temporal windows for such synaptic modification and that the generally accepted input- (or synapse-) specific rule for modification appears not to be strictly adhered to. Spike timing‐ dependent modifications, together with selective spread of synaptic changes, provide a set of cellular mechanisms that are likely to be important for the development and functioning of neural networks. When an axon of cell A is near enough to excite cell B or repeatedly or consistently takes part in firing it, some growth or metabolic change takes place in one or both cells such that A’s efficiency, as one of the cells firing B, is increased. Donald Hebb (1949)