Search PubMed⌕ Search

Biomedical subjects

P Thompson

Publications and source records attributed to P Thompson.

At least 325 records · Page 18Linked to original sources
PubMedDate not supplied

Natural hazards: causes and effects. Lesson 5--Tropical cyclones (hurricanes, typhoons, baguios, cordonazos, tainos).

The many conclusions drawn and lessons learned from past cyclones can be used to mitigate and better respond to future occurrences. Some of the most helpful are listed below: 1) Outbreaks of cholera do not follow cyclones. Cholera must be endemic previously to a community; 2) Waterborne diseases do not increase as a result of cyclones; 3) Massive food aid rarely is required after a cyclone; 4) Used clothing almost never is needed. It usually is culturally inappropriate. Though accepted by disaster victims, it almost never is worn; 5) Blankets can be useful, but if they are needed, they usually can be found locally and do not need to be imported; 6) Assistance by outsiders is most effective in the reconstruction period, not the emergency phase; 7) Most needs are met by the victims themselves or their local governments; 8) In general, victims do not respond to disasters with abnormal behavior. Cyclones do not incite panic, hysteria, or rioting; 9) Cyclone relief and reconstruction programs should be integrated with long-term development programs; 10) When properly executed, reconstruction assistance can provide a strong stimulus to recovery and a base for future development work; 11) Reconstruction programs should seek to reduce vulnerability to future disaster; 12) Re-establishment of the local economy, income security, and agriculture usually are more important to cyclone victims than is material assistance; and 13) Churches, schools, and other large buildings that often are designated as cyclone shelters usually are not safe. The number of deaths attributed to destroyed or flooded shelters is alarming. Most experts agree that the best alternative is adequate warning and evacuation of the threatened areas.

Disaster Planning↗
PubMedDate not supplied

Natural hazards: causes and effects. Lesson 7-Drought.

Drought has long been recognized as one of the most insidious causes of human misery. Today, it is the natural disaster that annually claims the most victims. Its ability to cause widespread misery is estimated to be increasing. While generally associated with semiarid climates, drought may occur in areas that normally enjoy adequate rainfall and moisture. In the broadest sense, any lack of water for the normal needs of agriculture, livestock, industry, or human population may be termed as a drought. The cause may be lack of supply, contamination of supply, inadequate storage or conveyance facilities, or abnormal demand. Drought is a condition of climatic dryness severe enough to reduce soil moisture and water below the minimums necessary for sustaining plant, animal, and human life. Drought usually is accompanied by hot, dry winds and may be followed by damaging floods. More socially relevant than technically correct is the definition used by Ari Toubo Eibrahim, the minister of agriculture in Niger, who has said that a drought is "Not as much water as the people need."

Disaster Planning↗
PubMedDate not supplied

Colour-contingent after-effects are really wavelength-contingent.

McCollough reported that following adaptation to (say) a red and black pattern of vertical stripes, alternating every few seconds with a green and black pattern of horizontal stripes, an orientation-contingent colour after-effect is observed when black and white gratings are viewed. Vertical gratings are tinged with green and horizontal gratings with pink. We have exploited colour constancy, the tendency for objects to appear constant in hue despite large changes in the spectral composition of the illuminant, to examine whether the colours observed on the McCollough effect test gratings are determined by the wavelength composition of the adaptation patterns or by their perceived colour. The key to this approach can be illustrated by Edwin Land's elegant demonstrations of colour constancy using 'Mondrian' displays. By embedding the adapting grating that is used to induce the McCollough effect within a Mondrian we show that the effect depends upon the wavelength of light coming from the grating, rather than the perceived colour.

Adaptation, Biological↗
PubMedDate not supplied

Platelet and erythrocyte membrane fluidity changes in alcohol-dependent patients undergoing acute withdrawal.

This study tested the hypothesis that membrane fluidity may alter during the alcohol-withdrawal syndrome. Platelet membranes of alcohol-dependent patients (n = 7) were significantly more rigid than controls (n = 7) at the start of alcohol withdrawal (mean fluorescence anisotropy 203.1 x 10(-3) vs 195.5 x 10(-3) respectively, P = 0.03), but were significantly more fluid when withdrawal was complete (191.4 x 10(-3) vs 199.2 x 10(-3), P = 0.03). Consequently platelet membranes of patients adapted to the known acute fluidizing effect of alcohol by becoming more rigid, but underwent a marked fluidization during withdrawal. There were no significant changes in erythrocyte membrane fluidity during withdrawal.

Acute Disease↗
PubMedDate not supplied

Regional spatial normalization: toward an optimal target.

PURPOSE: The purpose of this work was to develop methods for defining, constructing, and evaluating a "minimal deformation target" (MDT) brain for multisubject studies based on analysis of the entire group. The goal is to provide a procedure that will create a standard, reproducible target brain image based on common features of a group of three-dimensional MR brain images. METHOD: The average deformation and dispersion distance, derived from discrete three-dimensional deformation fields (DFs), are used to identify the best individual target (BIT) brain. This brain is assumed to be the one with the minimal deformation bias within a group of MR brain images. The BIT brain is determined as the one with the minimal target quality score, our cost function based on the deformation displacement and dispersion distance. The BIT brain is then transformed to the MDT brain using an average DF to create an optimized target brain. This analysis requires the calculation of a large number of DFs. To overcome this limitation, we developed an analysis method (the fast method) that reduces the task from order N2 complexity to one of order N, a tremendous advantage for large-N studies. RESULTS: Multiscale correlation analysis in a group of 20 subjects demonstrated the superiority of warping using the MDT target brain, made from the BIT brain, over several individual and MDT-transformed target brains also from the group. CONCLUSION: Analysis of three-dimensional DF provides a means to quickly create a reproducible MDT target brain for any set of subjects. Warping to the MDT target was shown by an independent multiscale correlation method to produce superior results.

Adult↗
PubMedDate not supplied

Comparison of 2 wound volume measurement methods.

OBJECTIVE: To compare 2 wound volume measurement techniques, the Kundin device and stereophotogrammetry, on 2 wound shapes. DESIGN: Using 2 wound measurement techniques, the interrater and intrarater reliability and the bias and standard error of measurement of an L-shaped and a pear-shaped plaster of paris wound model were assessed. SETTING: A clinical laboratory of a school of nursing. PARTICIPANTS: Twenty-four raters, all but 2 being registered nurses, measured each of the wounds using both techniques. INTERVENTIONS: Each rater measured each wound twice using each method in a randomly assigned order defined on a card that was drawn from a box. Measurements were recorded on a researcher-designed data collection form, which included some demographic data related to each participant. MAIN OUTCOME MEASURES: The study hypothesis was that there would be no significant difference in accuracy between the 2 wound volume measurement methods. RESULTS: The least biased and most accurate technique was stereophotogrammetry, with the smallest standard of error of measurement. Interrater reliability of average ratings was identical for both methods at 0.98. For single ratings, stereophotogrammetry was slightly higher than the Kundin device. Intrarater reliability was higher on the pear-shaped wound for the Kundin device, which had lower interrater reliability, suggesting that nurses were consistent in the direction and size of personal error. Intrarater reliability for stereophotogrammetry was identical to that of the Kundin device for the L-shaped wound and lower for the pear-shaped wound. CONCLUSIONS: Although both techniques have acceptable accuracy, stereophotogrammetry is more accurate and has more clinical applications.

Adult↗
PubMedDate not supplied

A four-dimensional probabilistic atlas of the human brain.

The authors describe the development of a four-dimensional atlas and reference system that includes both macroscopic and microscopic information on structure and function of the human brain in persons between the ages of 18 and 90 years. Given the presumed large but previously unquantified degree of structural and functional variance among normal persons in the human population, the basis for this atlas and reference system is probabilistic. Through the efforts of the International Consortium for Brain Mapping (ICBM), 7,000 subjects will be included in the initial phase of database and atlas development. For each subject, detailed demographic, clinical, behavioral, and imaging information is being collected. In addition, 5,800 subjects will contribute DNA for the purpose of determining genotype- phenotype-behavioral correlations. The process of developing the strategies, algorithms, data collection methods, validation approaches, database structures, and distribution of results is described in this report. Examples of applications of the approach are described for the normal brain in both adults and children as well as in patients with schizophrenia. This project should provide new insights into the relationship between microscopic and macroscopic structure and function in the human brain and should have important implications in basic neuroscience, clinical diagnostics, and cerebral disorders.

Adolescent↗
PubMedDate not supplied

Integration of clinical physics in radiation therapy education.

The need and importance of training in clinical physics for the radiation student cannot be overemphasized. Through the approach described--the integration of clinical physics tutorial sessions with radiation therapy educational programs--there is no doubt that the student should be well versed in clinical physics before the completion of the program. It will enhance the technologists's position among his colleagues and he will be able to communicate intelligently with the three-member team--the radiation oncologist, the clinical physicist, and the radiation therapy technologist. The time and effort that the physics section extends to the student in radiation therapy technology will only enhance the professional status of the radiation therapy technological community.

Biophysics↗
PubMedDate not supplied

Radiation therapy technology: profile of a profession.

This paper is a descriptive study of radiation therapy technology. Demographic, socioeconomic, and professional data were collected on the basis of questions sent to all registered radiation therapy technologists. In addition, opinions regarding the views on the education and entry level of the profession were solicited. The study was designed to provide baseline data for future study.

Adult↗