Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “experience sampling methodology”

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 901 records · Page 50Linked to original sources
PubMed1997

Trypanosoma cruzi: evaluation of a RAPD synapomorphic fragment as a species-specific DNA probe.

A methodological approach is proposed to select rapidly DNA sequences characterized by a well defined specificity and potentially interesting to be used as diagnostic probes or as taxonomic and phylogenetic markers. A fragment amplified from a diversified sample of Trypanosoma cruzi stocks by the RAPD (random amplified polymorphic DNA) method with the A8 primer, previously found to be monomorphic in all stocks, was separated in 2 fragments using polyacrylamide electrophoresis. RFLP (restriction fragment length polymorphism) analysis of the 750-bp fragment common to all stocks revealed some sequence heterogeneity within the T. cruzi species, whereas hybridization experiments showed a high homology between fragments amplified from different T. cruzi stocks. These results suggest that sequence analysis will allow the design of internal primers to be used as probes to target specific taxonomic levels (clone, family of related clones, or species) and for diagnosis.

Animals↗
PubMed2003

Effects of fear and anger on perceived risks of terrorism: a national field experiment.

The aftermath of September 11th highlights the need to understand how emotion affects citizens' responses to risk. It also provides an opportunity to test current theories of such effects. On the basis of appraisal-tendency theory, we predicted opposite effects for anger and fear on risk judgments and policy preferences. In a nationally representative sample of Americans (N = 973, ages 13-88) fear increased risk estimates and plans for precautionary measures; anger did the opposite. These patterns emerged with both experimentally induced emotions and naturally occurring ones. Males had less pessimistic risk estimates than did females, emotion differences explaining 60 to 80% of the gender difference. Emotions also predicted diverging public policy preferences. Discussion focuses on theoretical, methodological, and policy implications.

Adolescent↗
PubMed2003

Methods for a randomized trial of weight-supported treadmill training versus conventional training for walking during inpatient rehabilitation after incomplete traumatic spinal cord injury.

The authors describe the rationale and methodology for the first prospective, multicenter, randomized clinical trial (RCT) of a task-oriented walking intervention for subjects during early rehabilitation for an acute traumatic spinal cord injury (SCI). The experimental strategy, body weight-supported treadmill training (BWSTT), allows physical therapists to systematically train patients to walk on a treadmill at increasing speeds typical of community ambulation with increasing weight hearing. The therapists provide verbal and tactile cues to facilitate the kinematic, kinetic, and temporal features of walking. Subjects were randomly assigned to a conventional therapy program for mobility versus the same intensity and duration of a combination of BWSTT and over-ground locomotor retraining. Subjects had an incomplete SCI (American Spinal Injury Association grades B, C, and D) from C-4 to T-10 (upper motoneuron group) or from T-11 to L-3 (lower motoneuron group). Within 8 weeks of a SCI, 146 subjects were entered for 12 weeks of intervention. The 2 single-blinded primary outcome measures are the level of independence for ambulation and, for those who are able to walk, the maximal speed for walking 50 feet, tested 6 and 12 months after randomization. The trial's methodology offers a model for the feasibility of translating neuroscientific experiments into a RCT to develop evidence-based rehabilitation practices.

Exercise Test↗
PubMedDate not supplied

[Details of the evolution of the influenza epidemic process in the city of Bucharest in 1974].

The present paper reports on the results of a complex epidemiologic survey of the epidemiologic potential of influenza in Bucharest in 1974, conducted on the basis of a complete, unitary methodology including; (a) Dynamic survey of the morbidity and mortality from influenza, with statistical-mathematical processing of the data per age group and total population; (b) Monthly sero-epidemiologic survey of the antiinfluenza immunologic profile of the population, determined in lots of 540 sera (annual total 7020 serum samples), with statistical-mathematical processing of the serograms; (c) Serodynamic determinations of 67 paired serum smaples collected from patients presenting influenza syndromes during ascension of the epidemic morbidity from influenza; (d) Complex epidemiologic surveys in representative influenza foci in children, adolescent and adult communities. Based upon the result obtained the authors discuss the evolutive particularities of the epidemiologic process in Bucharest, particularly during the epidemic ascension of the first trimester of 1974, caused by the intensified circulation of influenza virus type B. The orientative value of certain elements for the epidemiologic prognosis is emphasized, such as: the immunologic profile of the population per age group with regard to the circulating influenza virus strains (autochtonous or imported strains), active control of the incidence of influenza in communities (technical schools etc.) or enterprises with a large number of employees, laboratory etiologic determinations in cases of a clinical diagnosis of influenza in a preepidemic season. The authors' ten years experience in the active survey of the active epidemiologic potential of influenza in the town of Bucharest shows that the methodology applied was efficient both for scientific assessing of the epidemiologic situation and for an orientation in the choice of preventive and control measures.

Adolescent↗
PubMed2006

Mechanical morphogenesis: a concept applied to the surface of the radius.

The purpose of this study is to perform a detailed morphological analysis of the changes that occur at the attachment sites of muscles, tendons, and ligaments on the radius. We consider the osteological, anatomical, and pathological aspects in detail, devising a visual standard for ranking the development of osseous expression at each attachment. We also discuss the etiology, particularly through focus on the relationship with the activity and age variables. In a sample of 148 radii from archeological and contemporary samples, 11 osteological sites were analyzed in each specimen. The osteological sites included nine muscular attachments, the attachment of the interosseous membrane, and the groove of the extensor pollicis longus tendon. The results show that mechanical loading is the main cause of different types of markings appearing and developing on the bone surface. Furthermore, there is a relationship between the osteological appearance of enthesis and its morphological type. It is possible to grade osteological appearance with a visual reference method that establishes an identifiable threshold for each grade and eliminates relying completely on observer experience. This methodology is applicable to the field of physical anthropology and to its forensic subfield, identifying individuals by attributing to them specific work or given activities through the use of skeletal remains.

Adolescent↗
PubMed1990

Identifying bluetongue virus ribonucleic acid sequences by the polymerase chain reaction.

A primer-directed nucleic acid amplification reaction, commonly known as the polymerase chain reaction (PCR), has been adapted to the identification of bluetongue virus (BTV) RNA. The protocol described in this article is designed for the detection of a purported globally-conserved, serogroup specific nucleic acid sequence within the BTV genome. Due to the double-stranded RNA composition of the BTV genome, the original polymerase chain reaction protocol has been modified to include chemical denaturation and reverse transcription steps that allow selective amplification from this unique template molecule. The amplification procedure yields a 210 base pair product when tested on samples of RNA from the prototypic strains of U.S. BTV serotypes 2, 10, 11, 13, 17. The amplification product is tentatively identified by agarose gel electrophoresis of the PCR samples. Final positive identification of the amplified BTV-specific product is determined by Southern blot hybridization of the PCR samples. RNA samples from uninfected cell culture controls and from cell cultures infected with two serotypes of epizootic hemorrhagic disease of deer (EHDV) yielded negative results. Preliminary experiments to quantify the threshold of sensitivity of this protocol, as described here, indicate positive detection of the BTV target RNA sequence at a level of less than 2 fg, or the amount of target sequence derived from less than 7500 viral particles. While this falls short of the theoretical limit of sensitivity of the PCR, the enhanced threshold of sensitivity of the PCR reaction compared to standard nucleic acid hybridization methodology suggests that rapid detection of BTV RNA directly within clinical specimens may be feasible with further refinements. Potential methods of enhancing this reaction are discussed.

Animals↗
PubMed2000

Determination of imidacloprid and its metabolite 6-chloronicotinic acid in greenhouse air by high-performance liquid chromatography with diode-array detection.

A method is described for analysing and sampling imidacloprid and its metabolite 6-chloronicotinic acid in greenhouse air by high-performance liquid chromatography (HPLC) with diode-array detection (DAD). The trapping efficiency of two solid sorbents, Amberlite XAD-2 and Amberlite XAD-4 and the use of different desorption procedures have been tested. To validate the methodology, standard atmospheres containing known concentrations of these pesticides and with different relative humidities were generated. No breakthrough was observed in the range of concentrations studied. Dissipation of analytes was investigated in a 24 h period after application by using personal samplers in a field experiment.

Air Pollutants↗
PubMedDate not supplied

Optimization of ion-exchange protein separations using a vector quantizing neural network.

In this work, a previously proposed methodology for the optimization of analytical scale protein separations using ion-exchange chromatography is subjected to two challenging case studies. The optimization methodology uses a Doehlert shell design for design of experiments and a novel criteria function to rank chromatograms in order of desirability. This chromatographic optimization function (COF) accounts for the separation between neighboring peaks, the total number of peaks eluted, and total analysis time. The COF is penalized when undesirable peak geometries (i.e., skewed and/or shouldered peaks) are present as determined by a vector quantizing neural network. Results of the COF analysis are fit to a quadratic response model, which is optimized with respect to the optimization variables using an advanced Nelder and Mead simplex algorithm. The optimization methodology is tested on two case study sample mixtures, the first of which is composed of equal parts of lysozyme, conalbumin, bovine serum albumin, and transferrin, and the second of which contains equal parts of conalbumin, bovine serum albumin, tranferrin, beta-lactoglobulin, insulin, and alpha -chymotrypsinogen A. Mobile-phase pH and gradient length are optimized to achieve baseline resolution of all solutes for both case studies in acceptably short analysis times, thus demonstrating the usefulness of the empirical optimization methodology.

Algorithms↗
PubMed1997

Personality and well-being: reexamining methods and meanings.

Because measures of personality and well-being share common affective underpinnings and items, previously reported links between these domains may be tautological. To explicate the connections between personality and well-being, 2 samples of midlife adults (N = 215 and N = 139) completed measures of personality (NEO Five Factor Inventory; P.T. Costa & R.R. McCrae, 1992) and psychological well-being (C. D. Ryff's, 1989b, Psychological Well-Being [PWB] inventory) that were maximally distinct, both conceptually and methodologically. Analyses included additional controls for source overlap, common affective underpinnings, and shared item content. Distinctive personality correlates were observed for the 6 PWB outcomes: self-acceptance, environmental mastery, and purpose in life were linked with Neuroticism (N) Extraversion (E) and Conscientiousness (C); personal growth was linked with Openness to Experience (O) and E; positive relations with others was linked with Agreeableness (A) and E; autonomy was linked with N. Psychological wellness and its personality correlates may be more complex than prior studies suggest.

Adult↗
PubMed1997

Detection of resin acid compounds in airborne particulate generated from rosin used as a soldering flux.

Various uses of rosin and exposure to its resin acid constituents have been associated with dermal and pulmonary sensitization. Methodology is presented to detect resin acids common to rosin (such as abietic and dehydroabietic acid) found in aerosol from heated rosin flux. Air filtration, solvent filter extraction, and gas chromatography/mass spectrometry were used to provide qualitative and quantitative information on the resin acid content of aerosol produced during soldering with rosin flux. Abietic acid and dehydroabietic acid were identified and quantified in aerosol derived from heated rosin flux, in samples collected in the field and in laboratory generated samples. Other resin acids (including several apparently oxidized resin acids) were detected, but not quantified. Laboratory mass balance experiments using soldering temperatures and liquid rosin flux showed that much of the nonvolatile material originally present in unheated flux may be captured on a sampling filter following heating and aerosolization. The data presented suggest that resin acids are a major component (with regard to mass) of the airborne contaminants produced during soldering with rosin flux. Abietic acid was shown to be unstable on sampling filters held for a period of weeks, while dehydroabietic acid and total solvent-soluble material were not found to degrade under the same conditions. Rosin aerosol produced in the laboratory using a soldering iron and liquid rosin flux produced particles shown to be of respirable size using scanning electron microscopy.

Abietanes↗
PubMedDate not supplied

Trends in the content and methodology of Alzheimer caregiving research.

Research into the experience of caregiving for patients with Alzheimer disease continues to grow steadily both in the number of studies and the scope of investigation. A review of the current trends in the content and methodology of research into caregiving is provided as a guide for new investigators entering this field. Whereas most studies continue to focus on the stress and burden associated with caregiving, increased study into topics such as treatment utilization, clinical decision-making, and caregivers and early detection will continue to broaden and enrich the scope of investigation. Positive trends in research methodology, including improved sampling procedures, more frequent inclusion of control groups, the use of improved measurement techniques, and the use of more sophisticated designs and statistics, will all continue. Despite the many contributions of past research into caregiving, future studies promise to make a critical contribution to a number of fields of study.

Aged↗
PubMed1985

Quantitative determination of bacterial replication in vivo.

A new methodology which permits the quantitative measurement of absolute bacterial replication in vivo is proposed. Mice were inoculated with mixtures of temperature-sensitive mutants and parental wild types, and the changes in the ratios of the two strains were measured. The number of wild-type generations was calculated from the declining ratios over time with the formula n = log (r0/rt)/log 2; n is the number of generations, and r0 and rt are the ratio of temperature-sensitive mutants to the parental wild type at time zero and at the times sampled throughout the experiment. The replication rate was determined by regression analysis. A mathematical argument for the formula is presented. Using this technique, we determined the mean generation times of Escherichia coli (33 min) and Pseudomonas aeruginosa (20 min) in the peritoneal cavities of mice, in the face of host clearance mechanisms during the first stages of infection.

Animals↗
PubMedDate not supplied

Design of the 1986 National Mortality Followback Survey: considerations on collecting data on decedents.

The first National Mortality Followback Survey in 18 years was conducted by the National Center for Health Statistics on a national probability sample of adult deaths in the United States in 1986. Data were collected on (a) socioeconomic differentials in mortality, (b) prevention of premature death by inquiring into the association of risk factors and cause of death, (c) health care services provided in the last year of life, and (d) the reliability of certain items reported on the death certificate. In addition to demographic characteristics of the decedent available from the death certificate and the questionnaire, information was secured on cigarette smoking practices, alcohol use, food consumption patterns, use of hospital, nursing home, and hospice care, sources of payment for care, duration of disability, and assistance with activities of daily living. A rich body of data was collected for analysis. In a large pretest, response was received from 87.3 percent of the next of kin of the decedents. The pretest included several methodologic studies to increase the level and quality of response in the main survey. Response rates were compared for data collection by mail, telephone, and personal interview. A test of certified mail and first class mail was conducted. Response to two forms of different lengths was compared. An experiment was also conducted on the effect of inclusion of boxes for a "don't know" response. A public use data tape is available from the National Center for Health Statistics.

Adult↗
PubMed1982

Stimulus-response profile analysis: a comprehensive, quantitative approach to the study of sensory coding and information processing.

In order to understand the coding and information processing capabilities of mechanosensory neurons, it is necessary to examine stimulus--response relationships under a wide variety of stimulus conditions, using a comprehensive set of quantitative analytic procedures. We employ the methodology of stimulus--response profile analysis, which is based on 4 principles: (1) the use of a broad-based battery of quantitatively controlled mechanical stimuli; (2) maintenance of comprehensive records of experiments; (3) detailed, quantitative analysis of single-unit responses; and (4) the application of these principles uniformly and consistently to all units studied. In addition to conventional graphical portrayals of single-unit activity, we employ a set of quantitative response indices, each of which represents a particular aspect of a unit's overall responsiveness. The distribution of a response index for the entire sample of neurons examined in a particular population offers insight into the manner in which a specific stimulus feature is presented within that population. The distributions of response indices obtained from different neural populations can be compared statistically in order to evaluate interpopulation differences in stimulus-response relationships. This comprehensive, quantitative approach is capable of demonstrating significant, although subtle, interpopulation differences which are not revealed by more cursory, qualitative methods.

Animals↗
PubMed2006

Factorial experimental design of winery wastewaters treatment by heterogeneous photo-Fenton process.

Winery wastewaters are difficult to treat by conventional biological processes because they are seasonal and experience a substantial flow variations. Photocatalytic advanced oxidation is a promising technology for wastewaters containing high amounts of organic matter. In this work, the photo-Fenton process in heterogeneous phase is presented as an alternative methodology for the treatment of winery wastewaters. As a consequence of the great number of existing variables, an experimental design methodology has been used in order to study the influence and interaction of various variables and to obtain a reduced empirical model which describes the organic matter degradation process. Applying photo-Fenton treatment in heterogeneous phase under energetic conditions for synthetic samples simulating winery wastewaters results in purification levels of up to 50% (measured as total organic carbon). Different reduced models are obtained and their utilization depends mainly on the degree of degradation of organic matter required.

Catalysis↗
PubMed1998

Migration, self-selection and earnings in Philippine rural communities.

"Estimated returns to schooling investments can be misleading if migration causes significant shifts in population distribution across time. Data gathered in rural Philippine communities show that the more educated and experienced individuals are more likely to outmigrate, causing a sample selection bias in the estimation of wage equations. The observed wages were then lower than the conditional population mean of an entire cohort residing originally in the area. Controlling for self-selection, the wage returns to schooling and experience were higher, Finally, the sample selectivity variable accounts substantially for the difference in the wages of men and women."

Asia↗
PubMed2006

Detecting differential and correlated protein expression in label-free shotgun proteomics.

Recent studies have revealed a relationship between protein abundance and sampling statistics, such as sequence coverage, peptide count, and spectral count, in label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) shotgun proteomics. The use of sampling statistics offers a promising method of measuring relative protein abundance and detecting differentially expressed or coexpressed proteins. We performed a systematic analysis of various approaches to quantifying differential protein expression in eukaryotic Saccharomyces cerevisiae and prokaryotic Rhodopseudomonas palustris label-free LC-MS/MS data. First, we showed that, among three sampling statistics, the spectral count has the highest technical reproducibility, followed by the less-reproducible peptide count and relatively nonreproducible sequence coverage. Second, we used spectral count statistics to measure differential protein expression in pairwise experiments using five statistical tests: Fisher's exact test, G-test, AC test, t-test, and LPE test. Given the S. cerevisiae data set with spiked proteins as a benchmark and the false positive rate as a metric, our evaluation suggested that the Fisher's exact test, G-test, and AC test can be used when the number of replications is limited (one or two), whereas the t-test is useful with three or more replicates available. Third, we generalized the G-test to increase the sensitivity of detecting differential protein expression under multiple experimental conditions. Out of 1622 identified R. palustris proteins in the LC-MS/MS experiment, the generalized G-test detected 1119 differentially expressed proteins under six growth conditions. Finally, we studied correlated expression of these 1119 proteins by analyzing pairwise expression correlations and by delineating protein clusters according to expression patterns. Through pairwise expression correlation analysis, we demonstrated that proteins co-located in the same operon were much more strongly coexpressed than those from different operons. Combining cluster analysis with existing protein functional annotations, we identified six protein clusters with known biological significance. In summary, the proposed generalized G-test using spectral count sampling statistics is a viable methodology for robust quantification of relative protein abundance and for sensitive detection of biologically significant differential protein expression under multiple experimental conditions in label-free shotgun proteomics.

Bacterial Proteins↗
PubMed1996

Refinement of the modified-relative-dose-response test as a method for assessing vitamin A status in a field setting: experience with Indonesian children.

The modified-relative-dose-response (MRDR) test, which has been used extensively throughout the world for assessing vitamin A status, has been simplified. The major methodologic change resulting from the current studies in Indonesia is the use of graded standard doses of 3,4-didehydroretinyl acetate (DRA) based on the age range of the population of interest. Instead of a dose of 0.35 mumol/kg body wt, standard doses of 5.3 mumol for children younger than 6 y, 7.0 mumol for children between 6 and 12 y of age, and 8.8 mumol for adults and children > 12 y of age are suggested for field use. The acceptable time between administering the oral dose and obtaining a blood sample was validated as being 4-7 h in a group of children (n = 84) by taking two blood samples per child between 3 and 7 h after dosing with DRA. Furthermore, DRA in vitamin E-containing corn oil, with or without the addition of 4.6 mmol all-rac-alpha-tocopheryl acetate/L, was found to be stable for > or = 18 mo at 2 degrees C and at -20 degrees C, but not at 22 degrees C or at 37 degrees C. When DRA was stored in amber glass vials, stability was affected more by temperature than by exposure to room light. In keeping with earlier studies in adults, the ratio of 3,4-didehydro-retinol to retino tends to be independent of body weight. Indeed, slower growing children (ie, those with lower weight-for-age) may have a somewhat better vitamin A status than their heavier counterparts.

Adult↗