University at Buffalo

About: University at Buffalo is a education organization based out in Buffalo, New York, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 33773 authors who have published 63840 publications receiving 2278954 citations. The organization is also known as: UB & State University of New York at Buffalo.

An iterative row-action method for interval convex programming

Abstract: The iterative primal-dual method of Bregman for solving linearly constrained convex programming problems, which utilizes nonorthogonal projections onto hyperplanes, is represented in a compact form, and a complete proof of convergence is given for an almost cyclic control of the method. Based on this, a new algorithm for solving interval convex programming problems, i.e., problems of the form minf(x), subject to γ≤Ax≤δ, is proposed. For a certain family of functionsf(x), which includes the norm ∥x∥ and thex logx entropy function, convergence is proved. The present row-action method is particularly suitable for handling problems in which the matrixA is large (or huge) and sparse.

Automatic detection of invasive ductal carcinoma in whole slide images with convolutional neural networks

Abstract: This paper presents a deep learning approach for automatic detection and visual analysis of invasive ductal carcinoma (IDC) tissue regions in whole slide images (WSI) of breast cancer (BCa). Deep learning approaches are learn-from-data methods involving computational modeling of the learning process. This approach is similar to how human brain works using dierent interpretation levels or layers of most representative and useful features resulting into a hierarchical learned representation. These methods have been shown to outpace traditional approaches of most challenging problems in several areas such as speech recognition and object detection. Invasive breast cancer detection is a time consuming and challenging task primarily because it involves a pathologist scanning large swathes of benign regions to ultimately identify the areas of malignancy. Precise delineation of IDC in WSI is crucial to the subsequent estimation of grading tumor aggressiveness and predicting patient outcome. DL approaches are particularly adept at handling these types of problems, especially if a large number of samples are available for training, which would also ensure the generalizability of the learned features and classier. The DL framework in this paper extends a number of convolutional neural networks (CNN) for visual semantic analysis of tumor regions for diagnosis support. The CNN is trained over a large amount of image patches (tissue regions) from WSI to learn a hierarchical part-based representation. The method was evaluated over a WSI dataset from 162 patients diagnosed with IDC. 113 slides were selected for training and 49 slides were held out for independent testing. Ground truth for quantitative evaluation was provided via expert delineation of the region of cancer by an expert pathologist on the digitized slides. The experimental evaluation was designed to measure classier accuracy in detecting IDC tissue regions in WSI. Our method yielded the best quantitative results for automatic detection of IDC regions in WSI in terms of F-measure and balanced accuracy (71.80%, 84.23%), in comparison with an approach using handcrafted image features (color, texture and edges, nuclear textural and architecture), and a machine learning classier for invasive tumor classication using a Random Forest. The best performing handcrafted features were fuzzy color histogram (67.53%, 78.74%) and RGB histogram (66.64%, 77.24%). Our results also suggest that at least some of the tissue classication mistakes (false positives and false negatives) were less due to any fundamental problems associated with the approach, than the inherent limitations in obtaining a very highly granular annotation of the diseased area of interest by an expert pathologist.

The etiology and prevalence of gingival recession

Abstract: Background Gingival recession in its localized or generalized form is an undesirable condition resulting in root exposure. The result often is not esthetic and may lead to sensitivity and root caries. Exposed root surfaces also are prone to abrasion. The purpose of this article is to describe the prevalence, etiology and factors associated with gingival recession. Types of Studies Reviewed The authors reviewed cross-sectional epidemiologic studies of gingival recession and found that they correlated the prevalence of recession to trauma, sex, malpositioned teeth, inflammation and tobacco consumption. The recent surveys they reviewed revealed that 88 percent of people 65 years of age and older and 50 percent of people 18 to 64 years of age have one or more sites with recession. The presence and extent of gingival recession also increased with age. Results More than 50 percent of the population has one or more sites with gingival recession of 1 mm or more. The prevalence of gingival recession was found in patients with both good and poor oral hygiene. It has been proposed that recession is multifactorial, with one type being associated with anatomical factors and another type with physiological or pathological factors. Recession has been found more frequently on buccal surfaces than on other aspects of the teeth. Clinical Implications Dentists should be knowledgeable about the etiology, prevalence and associating factors of gingival recession, as well as treatment options, so that appropriate treatment modalities can be offered to patients. Treatments for gingival recession include gingival grafting, guided tissue regeneration and orthodontic therapy. Such treatments typically result in esthetic improvement, elimination of sensitivity and a decreased risk of developing root caries.

Estimation of Left Ventricular Volume by One-Plane Cineangiography

Abstract: One-plane cineangiographic measurement of left ventricular volume uses angiocardiograms taken in the right anterior oblique view. Its basic assumption is that the third (unvisualized) dimension, depth from septum to free wall, is of the same magnitude and behaves in the same way as the visualized short axis. Examination of this assumption with biplane x-ray equipment revealed that the unmeasured length averages 7% less and varies directly with the length of the measured short axis. Volumes measured correlate well with consecutive studies using serial biplane x-rays and are systematically somewhat larger than volumes obtained in autopsy specimens injected with barium sulfate paste. The method is tolerant of variations in positioning of the patient, is convenient, yields repeatable analyses from one experienced observer to another, allows 60 volume measurements per second so that rapid cardiac events can be studied, and the small doses of x-rays and contrast medium permit several observations at one cathete...

The Effects of Parenting on the Development of Adolescent Alcohol Misuse: A Six-Wave Latent Growth Model.

Abstract: Alcohol use increases throughout adolescence. Based on family socialization theory, it was hypothesized that family factors, particularly parental support and monitoring, would influence individual trajectories in the development of alcohol misuse. Six waves of data were analyzed, based on interviews with 506 adolescents in the general population of a northeastern metropolitan area. Using growth-curve longitudinal analysis, results show that parenting significantly predicts adolescents' initial drinking levels (intercepts) as well as their rates of increase in alcohol misuse (slope). This study provides evidence that effective parenting is an important factor in preventing alcohol misuse. Key Words: adolescence, alcohol use, latent growth model, longitudinal study, parenting. A number of studies confirm that the earlier young people initiate alcohol use and frequent heavy drinking, the more likely they are to have alcoholrelated problems and alcohol dependence in adulthood (e.g., Barnes, Welte, & Dintcheff, 1992; Grant & Dawson, 1997). General population studies also show that the rates of alcohol misuse increase throughout adolescence. For instance, in a 1995 national survey of school students, 8% of the eighth graders reported that they had been drunk one or more times in the most recent 30 days, whereas 21% and 33%, respectively, of tenth and twelfth graders reported being drunk in the previous 30 days (Johnston, O'Malley, & Bachman, 1996). Similarly, in three large representative surveys of New York State secondary school students carried out over the past decade, the percentage of students who reported monthly heavy drinking (i.e., having five or more drinks at one time at least once a month for the past year) increased from 7% and 13%, respectively, among 12- and 13-year-olds to 47% and 50%, respectively, among 17- and 18-year-olds (Barnes, Welte, Hoffman, & Dintcheff, 1997). Aggregate rates from cross-sectional surveys such as these are often used to imply individual changes in alcohol misuse across the adolescent-young adult span of the life cycle. However, to more accurately assess changes in alcohol consumption and to determine the predictors of various developmental trajectories in adolescent alcohol misuse, longitudinal studies are required in which the same respondents are followed over time (i.e., panel studies). Thus, the prevention of alcohol misuse and alcoholism requires an understanding of what factors keep adolescents from initiating alcohol misuse and what factors dampen the spiraling increase in alcohol misuse during adolescence. Based on family socialization theory, we propose that parenting factors, particularly parental support and monitoring, are critically important influences on individual trajectories in the development of alcohol misuse throughout adolescence. THEORETICAL MODEL A large body of theoretical and empirical work shows the importance of parenting and parental socialization to the development of a variety of related adolescent problem behaviors, including alcohol misuse, illicit drug abuse, and delinquency (see Barnes, 1990; Barnes & Farrell, 1992; Farrell & Barnes, 1993). In a conceptual model of the development of adolescent alcohol misuse, elaborated elsewhere (Barnes, 1990), family socialization is shown as the linkage between individual factors (psychological and biological) and the larger culture (including sociodemographic factors). In this model, children learn social behaviors, including drinking behaviors, during the socialization process by ongoing interactions with significant others-initially with parents and subsequently with adolescent peers, who become increasingly influential during later adolescence. The parent-child relationships are seen as particularly potent and primary, occurring early in development and continuing throughout adolescence. Although there may be some bidirectional effects of parent and adolescent influences, most of the empirical research supports a "social mold" perspective (Peterson & Rollins, 1987) whereby parents exert powerful influences on the development of their children. …