Learning From Noisy Examples

Machine Learning - The basic question addressed in this paper is: how can a learning algorithm cope with incorrect training examples? Specifically, how can algorithms that produce an...     

PREPARATION OF HYDROTHERMALLY TREATED LRC/WATER FUEL SLURRIES

The hot-water coal drying process is a means of thermally beneficiating and dewatering lignite and subbituminous coal for the purpose of preparing dense low-rank coal/water fuel. In hot-water coal drying, which is a form of hydrothermal treatment, low-rank coal in a water slurry is treated at elevated temperatures of 513 to 623  K and at pressures in excess of the equivalent saturated steam pressures lo minimize vaporization of the water. This produces a coal product which contains less than one-third the inherent moisture of the raw coal and which is resistant to moisture reabsorption. The hydrothermally treated coal/water slurry resulting from the process can be concentrated by mechanical means (centrifuge, pressure filter)to form a pumpable coal/water fuel with greater than 60 weight percent bone-dry solids content and with an energy content greater than 15·4 MJ/Kg (6600 Btu/lb). Hydrothermal treatment also beneficiates the coal by reducing oxygen and minerals. Over 94 percent of the energy content of the raw coal remains in the product. Low-rank coal/water fuel is typically a pseudoplastic fluid, and for some low-rank coals, the slurry is stable towards settling, without the use of additives.     

Spontaneous and traumatic vitreous hemorrhage

PURPOSE: The authors sought to provide relevant data regarding the demographic and clinical aspects of spontaneous and traumatic vitreous hemorrhages to guide clinicians in better delineating the expected etiologic patterns of these hemorrhages in an urban environment. METHODS: The records of 253 consecutive patients with newly diagnosed vitreous hemorrhage seen in a general eye clinic were selected for retrospective analysis. To minimize selection bias of a tertiary care center, patients who were referred to the clinic by outside ophthalmologists for vitreoretinal consultation or those with a history of recent intraocular surgery, postoperative complications, or loss to follow-up were excluded from study. Demographic, ocular, and general medical variables were tabulated for the 200 patients (230 eyes) who met our inclusion criteria. RESULTS: Fifty percent of the patients were black, 26% were white, 23% were Hispanic, and 1% was Oriental. The causes of vitreous hemorrhage were proliferative diabetic retinopathy (PDR) (35.2%), trauma (18.3%), retinal vein occlusion (7.4%), retinal tear without a detachment (7.0%), posterior vitreous detachment (6.5%), proliferative sickle retinopathy (5.7%), retinal tear with a detachment (4.8%), subretinal neovascularization from macular degeneration (2.2%), hypertensive retinopathy (1.7%), unknown (2.5%), and other causes (8.7%). Among black patients with spontaneous vitreous hemorrhage, sickle cell retinopathy and retinal vein occlusion were major causes, each accounting for more than 15% of the cases. Systemic hypertension was associated with vitreous hemorrhage from retinal vein occlusion. CONCLUSION: The authors propose that despite the wide array of causative factors of vitreous hemorrhage, the evaluation of demographic, ocular, and medical variables can significantly aid clinicians in identifying its etiologic patterns.     

CLINICAL DIAGNOSIS AND OBJECTIVE TAT SCORING.

"In a previous paper the present writer has suggested the concept of personality orientation as a label for the psychological relatedness of person and environment… This study attempts to use personality orientation as a frame of reference in designing TAT scoring categories." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identification of cardiac rhythm features by mathematical analysis of vector fields

Automated techniques for locating cardiac arrhythmia features are limited, and cardiologists generally rely on isochronal maps to infer patterns in the cardiac activation sequence during an ablation procedure. Velocity vector mapping has been proposed as an alternative method to study cardiac activation in both clinical and research environments. In addition to the visual cues that vector maps can provide, vector fields can be analyzed using mathematical operators such as the divergence and curl. In the current study, conduction features were extracted from velocity vector fields computed from cardiac mapping data. The divergence was used to locate ectopic foci and wavefront collisions, and the curl to identify central obstacles in reentrant circuits. Both operators were applied to simulated rhythms created from a two-dimensional cellular automaton model, to measured data from an in situ experimental canine model, and to complex three-dimensional human cardiac mapping data sets. Analysis of simulated vector fields indicated that the divergence is useful in identifying ectopic foci, with a relatively small number of vectors and with errors of up to 30 degrees in the angle measurements. The curl was useful for identifying central obstacles in reentrant circuits, and the number of velocity vectors needed increased as the rhythm became more complex. The divergence was able to accurately identify canine in situ pacing sites, areas of breakthrough activation, and wavefront collisions. In data from human arrhythmias, the divergence reliably estimated origins of electrical activity and wavefront collisions, but the curl was less reliable at locating central obstacles in reentrant circuits, possibly due to the retrospective nature of data collection. The results indicate that the curl and divergence operators applied to velocity vector maps have the potential to add valuable information in cardiac mapping and can be used to supplement human pattern recognition.     

Bounded-Degree Independent Sets in Planar Graphs

An independent set of a graph is a set of vertices without edges between them. Every planar graph has an independent set of size at least (1/4)n and there are planar graphs for which any independent set has size at most (1/4)n. In this paper similar bounds are provided for the problem of bounded-degree independent set, i.e., an independent set where additionally all vertices have degree less than a pre-specified bound D. Our upper and lower bounds match (up to a small constant) for D 16.     

31P MAS NMR: a useful tool for the evaluation of VX natural weathering in various urban matrixes

The fate of chemical warfare agent VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate) in various urban matrixes was monitored utilizing 31P MAS NMR. Chosen matrixes represent buildings, roads, pavement, and earth found in urban environments. In view of the high toxicity of VX, solid state NMR afforded a fairly safe experimental mode, omitting any chance for evaporation. Moreover, due to the nondestructive nature of these experiments, measurements could be repeated over and over using the same samples. Degradation rates of VX were obtained and compared to provide a list of relative reactivity toward VX: concrete > desert sand > beach sand > asphalt approximately to bitumen sheet. Chemical interactions between VX, its degradation products, and the matrixes were often expressed by widening of the peaks to the extent that mass balance could not be achieved. It is noteworthy that these experiments were usually carried out on crushed or milled specimens, allowing high reactivity and rapid reactions.     

Linkage of the leuS, emtB, and chr genes on chromosome 5 in humans and expression of human genes encoding protein synthetic components in human--Chinese hamster hybrids

We isolated interspecific hybrids between normal human leukocytes and a Chinese hamster ovary cell line that has mutations in three genes, leuS, emtB, and chr, all of which are linked to chromosome 2. The conditionally lethal mutation in the leuS gene in this cell line affects leucyl-tRNA synthetase and renders the cell line nonviable at 39 degrees C. The mutation in the emtB locus alters ribosomal protein S14 and results in the cell line being resistant to the protein synthesis inhibitor, emetine, while the mutation in the chr locus renders the cells resistant to sodium chromate. The interspecific hybrids were selected at 39 degrees C so that they were required to retain and express the human leuS gene. Ten out of ten such heat-resistant hybrids also expressed the human emtB and chr genes. Segregants selected as having lost the human emtB gene simultaneously lost the human chr and leuS genes as well. The linkage relationship between these three genes has thus been conserved during the evolution of the human and Chinese hamster genomes. All three genes were localized to human chromosome 5. Furthermore, our results indicate that the ribosomal protein product of the human emtB gene is incorporated into functional ribosomes in place of the human corresponding Chinese hamster protein, raising several interesting questions concerning the coordinate regulation of genes encoding ribosomal proteins in mammalian cells.     

Review of Dissociation: Clinical and theoretical perspectives.

Reviews the book, Dissociation: Clinical and theoretical perspectives by Steven Jay Lynn and Judith W. Rhue (see record 1994-98908-000). In this book, the editors' stated purpose was to provide "a book that would be at once authoritative and provide virtually comprehensive coverage of important aspects of the topic," and they have largely achieved their goal. Because Dissociation is so comprehensive, there is in essence "something for everyone"; in turn, there may be sections of the book which are of less relevance to many readers. For example, clinicians who are primarily concerned about issues of diagnosis and treatment may find the discussion of the theoretical underpinnings of hypnosis and dissociation less than helpful. The sections on diagnosis and treatment, in turn, are of an overview nature; a clinician who is interested in more detailed discussions of these issues will have to go to the original sources. Nevertheless, this book might well be recommended as required reading for clinicians and researchers alike because of its very broad scope. The various authors address important questions which clinicians and researchers should consider. Dissociation makes clear that the concept of dissociation is one of the most complicated and misunderstood concepts in psychology. The history of the concept itself is reviewed at length in the book. Nevertheless, Lynn and Rhue have provided a resource in which a wide variety of perspectives of both a clinical and research nature are presented in a comprehensive yet accessible manner. (PsycINFO Database Record (c) 2010 APA, all rights reserved)