Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Probability Theory”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,351 records · Page 75Linked to original sources
PubMed1993

Choosing versus rejecting: why some options are both better and worse than others.

A previously unobserved pattern of choice behavior is predicted and corroborated. In line with the principle of compatibility, according to which the weighting of inputs is enhanced by their compatibility with output, the positive and negative dimensions of options (their pros and cons) are expected to loom larger when one is choosing and when one is rejecting, respectively. Subjects are presented with pairs of options, one of which--the enriched option--has more positive as well as more negative dimensions than does the other, impoverished, option. Because positive dimensions are weighted more heavily in choosing than in rejecting, and negative dimensions are weighted more heavily in rejecting than in choosing, the enriched option tends to be chosen and rejected relatively more often than the impoverished option. These findings are extended to nonbinary decision problems, and their implications for the rational theory of choice and for everyday decisions are discussed.

Adult↗
PubMed1999

Model-independent mean-field theory as a local method for approximate propagation of information.

We present a systematic approach to mean-field theory (MFT) in a general probabilistic setting without assuming a particular model. The mean-field equations derived here may serve as a local, and thus very simple, method for approximate inference in probabilistic models such as Boltzmann machines or Bayesian networks. Our approach is 'model-independent' in the sense that we do not assume a particular type of dependences; in a Bayesian network, for example, we allow arbitrary tables to specify conditional dependences. In general, there are multiple solutions to the mean-field equations. We show that improved estimates can be obtained by forming a weighted mixture of the multiple mean-field solutions. Simple approximate expressions for the mixture weights are given. The general formalism derived so far is evaluated for the special case of Bayesian networks. The benefits of taking into account multiple solutions are demonstrated by using MFT for inference in a small and in a very large Bayesian network. The results are compared with the exact results.

Child↗
PubMed2002

Diabetic neuropathy--choices of treatment.

Diabetic neuropathy represents a heterogeneous pathology taking place during diabetes mellitus (DM) evolution, hiding possibilities for rapid evolution which threaten even the life of the diabetic person. As a result, the recognition as precocious as possible of the neuropathy-induced alterations and the ways of treating this complication are essential. Diabetic neuropathy is classified in peripheral and vegetative, each of them with numerous clinical forms. Nevertheless, its etiopathogeny remains not totally understood, many theories existing for explaining it, its development being probably the result of a mixture of pathogenic mechanisms. Although there are difficulties in appreciation of the neuropathy prevalence in diabetic people, it is generally known that this alteration is one of the most frequent and invalidant major complication that affects this population, treatment as precocious as possible being essential. alpha-lipoic acid, substance with antioxidant properties, plays a central role in the energetic metabolism, principally functioning as a coenzyme in multienzymatic mitochondrial complexes alpha-lipoic acid has complex actions on different levels of the human organism, having many indications in different diseases, including DM. The results of numerous clinical studies have confirmed its efficacy in treating diabetic neuropathy. The present study has proposed itself to investigate the long-term effect of the short-term i.v. treatment with Thiogamma 600 (alpha-lipoic acid) in patients having type I or 2 DM, proving neuropathy symptoms and signs reduction evaluated in 3 months time, without metabolic control of the disease. If this amelioration proves to be persistent in time, with or without continuing the medication, this treatment will represent the most evident and efficient present solution in neuropathy.

Adult↗
PubMed2006

[The resistance of acupoint and its measurement].

We have analysed the significance of acupoint resistance and some probable problems in its measurement according to biophysics theories and we believe that the skin resistance plays an important role in acupoint resistance. The Volt-ampere curve should be used to describe acupoint resistance, and only when the measurements are under the same condition should the results be compared, because acupoint resistance is nonlinear. The acupoint resistance could be detected only in vivo. In this paper is presented a simple and easy method with which we can connect acupoint into electric circle. Also reported here is how to control the circumstance condition while measurements are taken.

Acupuncture Points↗
PubMed1990

[The image of Byzantine medicine in the satire "Timarion"].

Byzantine medicine is usually regarded as a static and non-creative descendant of classical Greek medicine, a point of view confirmed by the Byzantine medical texts. In this essay, the anonymous satire "Timarion" is analyzed in respect to its image of contemporary medical theory. Timarion, the fictive narrator, falls ill with a fever and is brought to Hades by two conductors of souls. They assert that he cannot survive, because he has secreted all his elementary bile. According to a decree by Asclepios and Hippocrates posted in Hades, any person that has lost one of his four elements may not live longer. In Hades Timarion sues to the court of judges of the dead. His lawyer, the sophist Theodore of Smyrna, persuades the judges that the bile excreted by Timarion has not been elementary in the sense of humoral pathology. So Timarion is allowed to return to life. The author of the satire ridicules the fundamental axiom of the four humours. Asclepios, Hippocrates and Erasistratos, who are attached to the infernal court as experts, cannot defend their theory against the convincing arguments of a sophist. The "divine" Galen, who probably would have been able to, is absent in order to complete a book of his. The "Timarion" with its harsh critique of medical theory is very amusing and a rare example of "actuality" in Byzantine literature.

History, Ancient↗
PubMed1988

A bayesian approach to the design of phase II clinical trials.

A new strategy for the design of Phase II clinical trials is presented which utilizes the information provided by the prior distribution of the response rate, the costs of treating a patient, and the losses or gains resulting from the decisions taken at the completion of the study. A risk function is derived from which one may determine the optimal Bayes sampling plan. The decision theoretic/Bayesian approach is shown to provide a formal justification for the sample sizes often used in practice and shows the conditions under which such sample sizes are clearly inappropriate.

Bayes Theorem↗
PubMed1985

A case of acardiac anomaly in the cynomolgus monkey (Macaca fascicularis): a complication of monozygotic monochorial twinning.

A case of acardius acephalus in a Macaca fascicularis is reported. This congenital anomaly occurs only in multiple-birth gestations (most commonly monozygotic twins). Artery-to-artery and vein-to-vein anastomoses appear to be a constant feature. This condition is very rare in man and probably even more so in monkeys. Classification and theories on etiology are discussed.

Abnormalities, Multiple↗
PubMed1985

Medical problem-solving: a critique of the literature.

Descriptive studies of clinical reasoning have been based primarily on an information-processing paradigm that has entailed microscopic analyses of the verbal behavior of small numbers of persons confronted with the task of making a diagnosis of a patient with symptoms of acute illness. From these studies, researchers have generally concluded: that medical problem-solving is an hypothetico-deductive process and that performance is not generalizable across problems. The author of the present paper argues that this narrow approach casts serious doubt on the validity of the conclusions and leaves unilluminated a large portion of the cognitive process involved in decisions about patient care. On the other hand, prescriptive, decision-analysis studies of medical problem-solving have generally been based on sophisticated decision theory that involves calculation and manipulation of complex probability and utility values in order to arrive at optimal decisions that will maximize patient benefits. While these prescriptive studies offer a methodology for improving clinical judgment, that methodology may not be one which decision-makers find attractive or feasible to employ.

Clinical Competence↗
PubMed1984

[Multiple sclerosis. Current etiopathogenic concepts].

The pathogenesis of multiple sclerosis is still poorly understood. Clearly, exogenous factors and genetic susceptibility combine to induce the disease, but studies on twins have shown that the genetic part is of minor importance. The immunological abnormalities observed do not fit easily into a coherent system. Derepression of antibody production in the central nervous system has been postulated and ascribed to failure of suppressor T-lymphocytes, but this is an over-simplification and the possibility that immunological abnormalities merely reflect a genetic predisposition cannot be dismissed. For many years, a viral origin has been suspected, yet the measles virus, at the top of the black list, must probably be discharged. Although the auto-immune theory remains attractive, the target antigen is still unknown in spite of numerous studies, and the signs of auto-immunity found in multiple sclerosis might well result from destruction of the nervous tissue instead of being the cause of the disease.

Antibody Formation↗
PubMed1982

Decision analysis and dental malpractice suits.

This article introduced the reader to the basic notions of decision analysis. The generic structure of decisions was introduced by means of an example. Using the concepts for analyzing malpractice suits was then discussed in the context of a hypothetical problem. Two points are worth noting: (1) decision analysis constructs have wide applicability, since the ingredients germane to decision problems across disciplines have important similarities; and (2) the purpose of engaging in formal analysis is to enhance understanding and description of a problem and to aid the decision-maker to be more explicit and more comprehensive in his search for a preferred course of action. Undoubtedly the article has raised some questions in the minds of the readers. In an elementary exposition such as this it is difficult to do full justice to the topics of decision analysis. The following references may be of interest.

Cost-Benefit Analysis↗