SEARCH · PubMed Health

Results for “interpretive description”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 1,477 records · Page 82Linked to original sources

PubMed2003

Energy resolution and dynamical heterogeneity effects on elastic incoherent neutron scattering from molecular systems.

Incoherent neutron scattering is widely used to probe picosecond-nanosecond time scale dynamics of molecular systems. In systems of spatially confined atoms the relatively high intensity of elastic incoherent neutron scattering is often used to obtain a first estimate of the dynamics present. For many complex systems, however, experimental elastic scattering is difficult to interpret unambiguously using analytical dynamical models that go beyond the determination of an average mean-square displacement. To circumvent this problem a description of the scattering is derived here that encompasses a variety of analytical models in a common framework. The framework describes the time-converged part of the dynamic structure factor [the elastic incoherent scattering function (EISF)] and lends itself to practical use by explicitly incorporating effects due to the finite energy resolution of the instrument used. The dependence of the elastic scattering on wave vector is examined, and it is shown how heterogeneity in the distribution of mean-square displacements can be related to deviations of the scattering from Gaussian behavior. In this case, a correction to fourth order in the scattering vector can be used to extract the variance of the distribution of mean-square displacements. The formalism is used in a discussion of measurements on dynamics accompanying the glass transition in molecular systems. By fitting to experimental data obtained on a protein solution the present methodology is used to show how the existence of a temperature-dependent relaxation frequency can lead to a transition in the measured mean-square displacement in the absence of an EISF change.

Journal Article↗

PubMed2003

Topological changes in a two-dimensional foam cluster.

Experiments on a small cluster of bubbles in a nominally two-dimensional foam show an instability in which a topological change forces one of the bubbles to be ejected to the outside of the cluster at a point where this is not predicted by a two-dimensional model of a foam. This is interpreted in terms of the energy of the initial and ejected states and of the finite liquid content of the experimental system. A description of the distribution of liquid in various experimental set-ups suggests that the exact response may depend critically upon the type of system used. This is demonstrated experimentally with reference to small clusters of bubbles undergoing a single topological change.

Journal Article↗

PubMed1997

The significance of neural ensemble codes during behavior and cognition.

The development of techniques to record from populations of neurons has made it possible to ask questions concerning the encoding of task-relevant information in awake, behaving animals. The issue of how groups of neurons within different brain structures register and retrieve representations of behaviorally significant events can now be addressed using multineuron-recording techniques. This review examines recent studies employing simultaneous recording of ten or more individual neurons in the mammalian brain. A major issue discussed is whether ensemble information content reconstructed from single-neuron recordings may be underestimated if compared to ensembles where those same neurons were recorded simultaneously. The mechanics of ensemble information encoding in the hippocampus is illustrated from population statistical analyses of ensemble activity during performance of a delay task. Detailed descriptions of methods of extracting ensemble information, as well as cross-correlational analyses, are discussed in the context of emergent issues regarding interpretation of ensemble data.

Animals↗

PubMed2005

Self-organization versus Watchmaker: stochastic dynamics of cellular organization.

The cell, as a molecular system, is often interpreted in terms of complex clockworks, and the design charts of mechanical and electrical engineering are assumed to provide adequate approximations for the description of cellular organization. However, a growing body of experimental evidence obtained through the observation and analysis of real-time dynamics of fluorescently labeled molecules inside living cells is increasingly inconsistent with the classico-mechanistic perception of the cell. An overview of recent studies favors an emerging alternative image of the cell as a dynamic integrated system of interconnected and interdependent metastable molecular organizations realized through stochasticity and self-organization.

Cells↗

PubMed2005

A comprehensive portrait of teleradiology in radiology practices: results from the American College of Radiology's 1999 Survey.

OBJECTIVE: This article presents a comprehensive portrait of the characteristics of teleradiology systems of radiology practices as of 1999. Our purposes are to help profile a rapidly evolving area of radiology that has been underexamined to date and to provide a baseline with which future findings can be compared. MATERIALS AND METHODS: In 1999, the American College of Radiology surveyed 970 practices by mail. A response rate of 66% was achieved. Responses were weighted to represent all radiology practices in the United States. Data from nine questions specifically designed to profile the use of teleradiology were analyzed using descriptive statistical methods and multivariate regression analyses. RESULTS: Seventy-one percent of multiradiologist practices had teleradiology systems in place, using them to interpret 5% of their studies. For solo practices, corresponding statistics were 30% and 14%. Ninety-two percent of multiradiologist practices with teleradiology systems used them for preliminary on-call interpretation. Other major uses included consultation with other radiologists (20%) and primary interpretation of studies (18%). Ninety-five percent of multiradiologist practices with teleradiology systems used them to interpret CT, 84% used them for sonography, 69% for nuclear medicine, 47% for MRI, and 43% for conventional radiographs. CONCLUSION: Teleradiology had already become a fixture in most practices by 1999, though it was used for only a small fraction of image interpretations. Its widespread presence positioned teleradiology to become a key element of radiology practice nationwide.

Diagnostic Imaging↗

PubMedDate not supplied

[Forensic neuropsychology: principal issues and applications].

INTRODUCTION: The term Forensic Neuropsychology refers to the application of the knowledge of the field of Neuropsychology to the legal matters. The field of Clinical Neuropsychology has experienced a great development, thanks to the investigations and publications that have been made both in the basic and applied fields. Nevertheless, only in the last years, clinical neuropsychologists have participated actively in the courts. DEVELOPMENT: The testimony as experts of neuropsychologists is more and more common. They inform to the judge on the behavioral, emotional and cognitive sequels following lesions to the human brain, as well as the importance of psychosocial variables in modulating brain function and dysfunction. The relationship between Neuropsychology and Law has been influenced by the confluence of a series of related factors that have contributed to the professionalization of this discipline. Among these, we can emphasize the study of brain-behavior relationships by means of quantitative methods, the interpretative strategies to infer the presence, location and type of neuropathology; the decision making on legal subjects like the determination of disability; the description of the characteristic cognitive-behavioral profiles of neurological disorders; the implication of the psychosocial variables and the decision on the most appropriate interventions. Some of the most important objectives of this new discipline are: the identification of the sequels of mild traumatic brain injury as the posconmocional syndrome , the determination of premorbid intellectual functioning and the valoration of cognitive loss. There is no doubt that in the next years this field of application of Clinical Neuropsychology is going to experience an important growth in our country, thanks partly, to the norms that are followed to establish the degree of disability and the compensations of the insurance agencies, that consider these neuropsychological sequelae.

Brain Damage, Chronic↗

PubMed2004

[Brain activity during language processing].

The neural system, responsible for language comprehension, must quickly process and integrate a large amount of heterogenous linguistic data. There is no appropriate and generally acceptable description of the architecture of this system. This means that no model of language processing is available that will allow, without problems, to interpret the wide range of disorders of language functions in neurological patients with focal lesions and explain the no less inconsistent results of experiments dealing with various aspects of language processing both in healthy people and in patients. In this paper are summed up the main findings from works of several authors who with electrophysiological recording techniques and metabolic imaging techniques (PET and MRI) sought answers to the question "where" and "how" in the brain are processed open class words and closed class words, nouns and verbs, or perhaps what is the temporal co-ordination and laterality of semantic and syntactic processes in language processing. The frequent contradictions in the findings, which a reader may quickly discover, are probably due to the design of the experiment, the properties of the stimulus applied, the type of the task to be solved during the experiment by its participants. In patients it may be also due to the accuracy of the determination of the anatomical localization and the extent of the lesions in nervous structures. In this context, however, it is necessary to be reminded that applied methods have their strong as well as weak points. Metabolic imaging techniques reliably inform of the exact localization of metabolically active brain structures, but they only give a rough picture of temporal dynamics of brain processes. On the other hand, electrophysiological techniques reflect precisely the temporal dynamics of neuronal activation near the recording electrode, but they say little about the activity of neuronal assemblies in areas remote from the site of registration.

Brain↗

PubMed2004

[Numerical modeling of ideal cohorts of aging organisms obeying the Gompertz-Makeham law in association with the Strehler-Mildwan correlation].

The Gompertz-Makeham law (-dn/dt x l/n(t)=C+lambdae(gammat)) so as other genuine laws of Nature is strictly applicable only to ideal objects (populations and cohorts) analogously to laws of mechanics or thermodynamics, which are exactly true only for such physical abstractions as mass points or ideal gases. Therefore, a biologically meaningful interpretation of the parameters of this law is likely to be more important for understanding the aging process than devising of alternative analytical descriptions of biodemographic processes for the sake of a better fit only. Numerical modeling of ideal cohorts of aging organisms obeying the Gompertz-Makeha law makes it possible to differentiate possible real and apparent changes in mortality patterns that occur in human history and in evolution and are observed in gerontological experiments and to demonstratively show such effects as the dependency of longevity upon population size, the evolutionarily important possibility of reciprocal changes in the mean and maximal longevity, or detection of apparent changes in negatively correlated aging rate and vitality when the Makeham term is ignored, which is usual in demography. The basic difference between the Makeham term Cand Gompertz term lambdae(gammat) is suggested to be not that the former is constant, whereas the latter is age-dependent, but that the former comprises the contributions of inherently irresistible stresses to mortality, whereas the latter comprises the contributions of resistible stresses to mortality and shows how changes in the ability to resist them is translated into changes in mortality.

Aging↗

PubMed2005

[Demographic and epidemiologic changes in Colombia during the 20th century: facts and explanations].

INTRODUCTION: Research, education, organization and administration activities in health need an updated panoramic view of demographic and epidemiologic changes and tendencies. OBJECTIVES: To describe the main changes in demography and epidemiology during the 20th century in Colombia and to comment on the causative models used by some authors. MATERIALS AND METHODS: A descriptive and longitudinal study. Second hand information from various sources was used. The final section of the review includes a discussion on the interpretation of data given by the original authors. RESULTS: In 1905-2005, population increased from 4,737,588 inhabitants to 48,864,013. The age distribution of the population showed dramatic changes: the true pyramid, as seen in 1951, changed into a distorted figure (no apparent differences between 0 and 14 years of age). Both children and youngsters lost representation on age structure, while adult and older individuals gain representation. During 1905-1938, the birth rate was 43% and by the end of 2005 it will be 22%. Mortality dropped a 75%, falling from 23% in 1905-1912 to 6% in 1885-1993, but it rose a 33% after 1993, and will reach 8.3% in 2010. In 1938, the urban population was 31% and in 2002, 72%. Mortality discriminated by cause changed in a significant manner during the second half of the 20th century. Infectious-parasitic and perinatal diseases, the main cause of death by the end of the 1960-1969 decade, lost importance on behalf of degenerative diseases, accidents and homicides which are now the most frequent. Conclusions. Our present population density is relatively low. The demographic change has been profound but the velocity has been more important. The aging of population has serious implications for the country. These notable modifications in Colombian families raise challenges in all social fields. The demographic and epidemiological changes (structure and level of morbimortality) require a serious analysis, and easy explanations do not have to be accepted without repairs.

Colombia↗

PubMed1978

A review of data on cell actions and cell interaction during the morphogenesis of the embryonic eye.

The early morphogenesis of the chick embryo seems to be an excellent model-system for study of morphogenetic movements, usually summarized in general terms like invagination, fusion and separation. This article reviews literature data about the early morphogenesis of the eye. The formation of lens vesicle and optic cup, during which invagination, fusion and separation are very important, were seen to represent a finely balanced interplay between cell mitosis, cell differentiation, cell death, cell transformation and cell migration. Differing observations and contradictory interpretations justify a systematic approach to to these embryological questions. We will attempt this in our next study. Apart from microscopic and submicroscopic description of closely succeeding developmental stages, three-dimensional reconstruction techniques will be indispensable to understand the spatial arrangement of the structures concerned.

Animals↗

PubMed1998

Projective assessment of Latinos in the United States: current realities, problems, and prospects.

This article discusses the current status of projective assessment with Latino populations in the United States and suggests improvements in the quality of these services and in assessor cultural competencies. Major issues have included assessor bias, culturally inappropriate service delivery etiquette, psychometric inadequacies of many methods, and ignorance of relevant cultural issues in assessment practice, particularly cultural identity descriptions for personality study and cultural formulations to increase accuracy of clinical diagnoses. A rationale for projective assessment is followed by descriptions of several tests. Suggestions for reduction of bias include guidelines for projective assessment practice and recommendations for resources to improve reliability of interpretations. A research method that combines training with validation of the outcome of the entire assessment process is described.

Cross-Cultural Comparison↗

PubMed1989

A computer-assisted procedure for the assembly and analysis of short-term genotoxicity test data.

Determining the genetic hazard of a chemical is generally approached by using an assortment of tests for measuring the DNA reactivity of a chemical or its resultant genotoxicity. Over 100 short-term tests employing a wide diversity of species and genetic mechanisms have been used to measure genetic hazard. To date, attempts to achieve a standard test battery for defining genetic hazard have not been successful. Consequently, testing for genetic hazard involves the use of test batteries with variable types and numbers of assays. This increases the difficulties of interpreting data sets since the data sets are often filled with inconsistent responses from diverse types of assays. Several years ago, the International Commission for Protection Against Environmental Mutagens and Carcinogens (ICPEMC) established a Committee to develop a method to compile and interpret diverse short-term test data. The Committee has produced a quantitative weight-of-evidence approach that combines test data using certain parameters such as dose, replication, and metabolic capacity into a series of scores for test type, test class, test family, and an overall score that defines the total weight-of-evidence regarding the genetic hazard of the agent. A description of the method and results from the evaluation of selected chemicals is provided.

Animals↗

PubMed1987

[A mathematical description of microecologic correlations].

Due to the diversity of microbiological interrelations results of animal experiments concerning the effect of nutrition factors on the microecological system in the intestinal tract are often difficulty to interpret. In order to reveal deeper correlations multivariate statistical methods particularly the non-linear multiple regression analysis are tried to use. First results show that correlations between nutrition factors and microecological signs of the colon content can be depict by quadratic polynoms, whereas for biochemical signs also a linear dependence appears possible.

Animals↗

PubMed2005

Sociocultural interpretations of social phobia in a non-heterosexual female.

Social Phobia is a prominent anxiety disorder that is not well-understood, especially among socially marginalized, non-heterosexual individuals. A case description of Social Phobia symptoms in a female who is unsure of her sexual identity is presented and analyzed. The diagnostic assumptions of Social Phobia as applied to the case are critically examined. The goal is to highlight unanswered questions regarding social anxiety among non-heterosexuals and to open a discussion of cultural etiological theory. Implications for treating Social Phobia with a cultural component are discussed.

Adult↗

PubMed1985

[Methodologic reflections on the establishment and interpretation of group median sagittal contours of the skull].

The normal lateralis is by far the most interesting of the normae of cranium, being that which contour is usually drawn to illustrate the description of the skull. The methods to assemble individual cranial profiles to group-profiles in order to get a typological impression of a random sample vary considerably. Some of these methods are discussed in this paper. On the basis of six medieval skulls from Remlingen (district Wolfenbüttel, Lower Saxony) an attempt is made to obtain a better comparability of form-variation in the cranial profiles by eliminating the factor of different length. Additionally a comparison of the single elements of the cranial profile is made and a new method for the drawing of group-profiles is recommended, which provides smaller differences in the form of the skulls compared than former methods.

Adult↗

PubMed2004

A unified description of the electrochemical, charge distribution, and spectroscopic properties of the special-pair radical cation in bacterial photosynthesis.

We apply our four-state 70-vibration vibronic-coupling model for the properties of the photosynthetic special-pair radical cation to: (1) interpret the observed correlations between the midpoint potential and the distribution of spin density between the two bacteriochlorophylls for 30 mutants of Rhodobacter sphaeroides, (2) interpret the observed average intervalence hole-transfer absorption energies as a function of spin density for six mutants, and (3) simulate the recently obtained intervalence electroabsorption Stark spectrum of the wild-type reaction center. While three new parameters describing the location of the sites of mutation with respect to the special pair are required to describe the midpoint-potential data, a priori predictions are made for the transition energies and the Stark spectrum. In general, excellent predictions are made of the observed quantities, with deviations being typically of the order of twice the experimental uncertainties. A unified description of many chemical and spectroscopic properties of the bacterial reaction center is thus provided. Central to the analysis is the assumption that the perturbations made to the reaction center, either via mutations of protein residues or by application of an external electric field, act only to independently modify the oxidation potentials of the two halves of the special pair and hence the redox asymmetry E0. While this appears to be a good approximation, clear evidence is presented that effects of mutation can be more extensive than what is allowed for. A thorough set of analytical equations describing the observed properties is obtained using the Born-Oppenheimer adiabatic approximation. These equations are generally appropriate for intervalence charge-transfer problems and include, for the first time, full treatment of both symmetric and antisymmetric vibrational motions. The limits of validity of the adiabatic approach to the full nonadiabatic problem are obtained.

Journal Article↗

PubMed1997

The use of 'racial' categories in contemporary South African health research. A survey of articles published in the South African Medical Journal between 1992 and 1996.

OBJECTIVE: In the light of growing concern about the clinical, social and political impact of 'racial' categorisation in health research, this survey aimed to re-evaluate the current use of 'racial' categories in articles published by the South African Medical Journal. SURVEY DESIGN: Any categories that might have been used or interpreted as measures of genetically determined 'racial' differences (including 'racial', ethnic and sociopolitical 'population group' categories) were included in this survey of 668 articles describing South African health research published during the past 5 years. By classifying the research contained in each of these articles it was possible to assess the importance of 'racial' categorisation in study design. The explanations given for any 'racial' differences in health were then used to evaluate the impact of 'racial' categorisation on the perception that innate characteristics were responsible. RESULTS: Three hundred and seventeen (47.5%) articles mentioned one or more 'racial' categories, 292 (43.7%) of which used 'racial' categories to describe the subjects they studied. The commonest generic labels used for these categories were "race" and "population group", while the commonest descriptive labels referred to traditional 'racial' characteristics such as phenotype, nationality and geographical origin. Only 15 (5.1%) articles fully defined the categories and labels they used, and many more used different generic and descriptive labels interchangeably. The use of 'racial' categories was highest among genetic (73.9%), descriptive (55.3%) and quasi-experimental studies (38.2%), although most used these categories simply to describe the subjects they examined. Of those 162 (24.3%) articles that discussed 'racial' differences in health, only 120 (18.0%) contained an explanation, and 60 of these suggested that inherent genetic or behavioural factors were responsible. Nine articles contained derogatory statements that could be interpreted as prejudiced or racist. CONCLUSION: The use of 'racial' categorisation remains widespread in South African health research. By using generic and descriptive labels from traditional 'racial' taxonomies, many of these articles reinforce the perception that distinct human 'races' exist. Although most of the articles failed to explain any of the 'racial' differences in health they observed, it is likely that these will be interpreted as evidence of innate genetic or behavioural differences, like those suggested by the few articles that offered explanations. The continued use of 'racial' categorisation in health research might be inevitable, particularly for examining the impact of social forces, such as apartheid and other forms of racism, that use 'racial' categories to create unequal access to health and health care. However, any studies that use 'racial' categories should be careful to avoid legitimising the biological concept of 'race', misidentifying the causes of 'racial' disparities in health and reinforcing 'racial' prejudice.

Bias↗

PubMedDate not supplied

Data representation for subsequent image interpretation.

Radiological scans acquired using either the X-ray CT or the NMR imaging techniques provide a wealth of information about tissue behaviour under that imaging modality and contrast agent. To reason about the image in an interpretation stage the scans have to be converted from a pixel by pixel representation to a symbolic form. The technique used by us to generate such a description is region-based segmentation. Each region refers to a pixel or group of pixels having a common attribute. This work has provided a quantitative measure for the partial evaluation of the segmentation which can be applied independent of attribute or combination of attributes. From our initial studies of the behaviour of CT scans a precept for segmentation was developed. The segmentation employs a one-to-one map as an adaptive mechanism. The segmentation criterion at each point in the image therefore depends on the value at the corresponding point in the map. Any process can be used to generate this map, and so easily utilizes new operators as they are developed.

Artificial Intelligence↗