Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “adaptive sampling”

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 1,513 records · Page 84Linked to original sources

The influence of stimulus parameters on the visual field indices by automated projection perimetry.

The various stimulus parameters offered by two standard automated projection perimeters [Humphrey Field Analyser 630 (HFA) and Octopus 201], namely, stimulus size and location and the interaction of adaptation level and stimulus duration, were compared in a sample of 20 patients attending a glaucoma clinic using the visual field indices mean defect (MD), loss variance (LV), short-term fluctuation (SF) and corrected loss variance (CLV). LV and SF were greater with Octopus program 32 compared with Octopus program G1 (P < 0.02). No difference in the indices was found between stimulus sizes I and III for HFA program 30-2. MD was greater for program 30-2 compared with program 32 (P < 0.002) when expressed in terms of log (L/delta L) whereas LV (P < 0.02) and SF (P < 0.02) were greater for program 32. All differences were considered to be negligible in the clinical sense.

Adaptation, Ocular↗

High-performance liquid chromatographic determination of N-epsilon-(2-propenal)lysine in biological samples after derivatization with diethylethoxymethylenemalonate.

A recently reported methodology for amino acid analysis by HPLC has been adapted for quantification of N-epsilon-(2-propenal)lysine (a modified lysine by reaction with malondialdehyde that has been found in enzymatic digests of foods and in urine) in biological samples. We describe its use for investigating the in vitro degradation of N-epsilon-(2-propenal)lysine using rat tissue homogenates. Lysine dipeptide, used as a control in the incubation mixtures, and the lysine released by the hydrolytic action of the homogenates in the in vitro incubations are quantified in the same way. The samples are subjected to a cleanup prederivatization step using PD-10 disposable columns (Pharmacia). This allows precolumn derivatization with diethylethoxymethylenemalonate (50 min, 50 degrees C) and resolution of the derivatives of the compounds of interest by reversed-phase HPLC (binary gradient, 45 min) with quantification based on the uv absorption of the derivatives at 280 nm (detection limits below 1 pmol). The entire analysis takes 110 min. This method can be of general use for the determination of N-epsilon-(2-propenal)lysine in the context of research dealing with protein deterioration by reaction with malondialdehyde in biological systems and in foods. A method for the synthesis of N-epsilon-(2-propenal)lysine, used as external standard for the HPLC analysis, is described.

Animals↗

Effects of culturally adapted parent management training on Latino youth behavioral health outcomes.

A randomized experimental test of the implementation feasibility and the efficacy of a culturally adapted Parent Management Training intervention was conducted with a sample of 73 Spanish-speaking Latino parents with middle-school-aged youth at risk for problem behaviors. Intervention feasibility was evaluated through weekly parent satisfaction ratings, intervention participation and attendance, and overall program satisfaction. Intervention effects were evaluated by examining changes in parenting and youth adjustment for the intervention and control groups between baseline and intervention termination approximately 5 months later. Findings provided strong evidence for the feasibility of delivering the intervention in a larger community context. The intervention produced benefits in both parenting outcomes (i.e., general parenting, skill encouragement, overall effective parenting) and youth outcomes (i.e., aggression, externalizing, likelihood of smoking and use of alcohol, marijuana, and other drugs). Differential effects of the intervention were based on youth nativity status.

Adaptation, Psychological↗

The effect of rehabilitation on depression among visually disabled older adults.

There has been a great deal of interest in identifying the impact of rehabilitation on psychological well-being, as well as functional ability, among elders with disabilities, but empirical data remain limited. This descriptive study of participants in vision rehabilitation service examines the effect of specific vision rehabilitation services (low vision clinical services, skills training, counseling, optical device use, and adaptive device use) on change in depression among a sample of older adults with age-related vision impairments. Participants (N = 95) were interviewed at application for services and then approximately two years later. Findings from hierarchical regression analyses indicated that low vision clinical services, counseling, and use of optical devices, in separate models, each significantly contributed to a decline in depression, after controlling for age, health status, vision status, functional disability, as well as baseline depression. When all service variables were entered into the same equation, they explained an additional 10% of the variance in change in depression. Given the well documented robust relationship between disability and depression, findings point to the influence of vision rehabilitation interventions on both physical and psychological functioning, and underscore the need for future, controlled research on rehabilitation service models that address mental health issues.

Adaptation, Psychological↗

Application of microdialysis in pharmacokinetic studies.

The objective of this review is to survey the recent literature regarding the various applications of microdialysis in pharmacokinetics. Microdialysis is a relatively new technique for sampling tissue extracellular fluid that is gaining popularity in pharmacokinetic and pharmacodynamic studies, both in experimental animals and humans. The first part of this review discusses various aspects of the technique with regard to its use in pharmacokinetic studies, such as: quantitation of the microdialysis probe relative recovery, interfacing the sampling technique with analytical instrumentation, and consideration of repeated procedures using the microdialysis probe. The remainder of the review is devoted to a survey of the recent literature concerning pharmacokinetic studies that apply the microdialysis sampling technique. While the majority of the pharmacokinetic studies that have utilized microdialysis have been done in the central nervous system, a growing number of applications are being found in a variety of peripheral tissue types, e.g. skin, muscle, adipose, eye, lung, liver, and blood, and these are considered as well. Given the rising interest in this technique, and the ongoing attempts to adapt it to pharmacokinetic studies, it is clear that microdialysis sampling will have an important place in studying drug disposition and metabolism.

Animals↗

INCLUSive: integrated clustering, upstream sequence retrieval and motif sampling.

INCLUSive allows automatic multistep analysis of microarray data (clustering and motif finding). The clustering algorithm (adaptive quality-based clustering) groups together genes with highly similar expression profiles. The upstream sequences of the genes belonging to a cluster are automatically retrieved from GenBank and can be fed directly into Motif Sampler, a Gibbs sampling algorithm that retrieves statistically over-represented motifs in sets of sequences, in this case upstream regions of co-expressed genes.

Algorithms↗

Growing or just getting along? Technical and adaptive competence in coping among adolescents.

This study examined coping among African American adolescents with learning disabilities. Ninety-seven African American adolescents and their mother or primary caregiver participated in the study. The study centered on a new conceptual distinction between technical competence in coping and adaptive competence in coping. Technical competence referred to short-term, reactive attempts at coping based on individuals' abilities to find techniques for reducing their feelings of distress. Adaptive competence referred to longer-term, developmental processes of adaptive change that resulted in more global benefits for the individual. Past literature was reassessed on the basis of this conceptual distinction, and a new model of technical and adaptive competence in coping was proposed based on developmental theory. Perceptions of coping efficacy and the incidence of behavioral problems were regressed on measures of technical and adaptive competence in coping. Results were explored first as a general test of the model on the total sample, and second as a comparative analysis between gender subsamples. Total sample findings were consistent with hypothesized results. Technical competence was a better predictor of feelings of efficacy and adaptive competence was a better predictor of behavioral problems. Gender subsample differences were significant and supported a picture of gender-typed approaches to coping.

Adaptation, Psychological↗

French adaptation of the shortened version of the Profile of Mood States.

The French adaptation and validation of the short version of the Profile of Mood States is examined. A sample of 110 women diagnosed with breast cancer and 50 men with prostate cancer were administered the French Canadian adaptation of the shortened version of the profile (37 items). Means, test-retest correlations, and internal consistency coefficients (alpha) replicated the English initial validation. These results support the reliability of the French Canadian version. In addition, significant decrease from initial to retest testing for Anxiety, Depression, and Confusion subscales also supported construct validity.

Female↗

Simple method to observe the adaptive response of Listeria monocytogenes in food.

A simple, novel method for determining stress-adaptive response of Listeria monocytogenes in food systems is presented. The method involves plating samples on Listeria-selective agar (LSA) acidified to pH 5.25 with incubation at 36 degrees C for 60 h to detect acid adaptation and plating on LSA with 70 gl-1 NaCl and incubation at 7 degrees C for 7 d to detect cold-osmotic adaptation. Adapted cells produced larger colonies (> 1 mm) under these conditions than unadapted cells. Scot A (97%) and Brie-1 (100%) cells incubated in milk at pH 5 for 3 h manifested the acid-adapted colony type compared with 6% and 21% of viable cells in the unstressed control population. After a 5-d adaptation period at 4 degrees C in milk with 80 gl-1 salt, 29% of Scot A and 91% of Brie-1 viable cells exhibited the adapted colony type compared with < 1% of the unstressed control population. Stress-adapted L. monocytogenes were isolated from soft cheese held for 42 d at 10 C.

Adaptation, Physiological↗

Application of the BioMek 2000 Laboratory Automation Workstation and the DNA IQ System to the extraction of forensic casework samples.

Robotic systems are commonly utilized for the extraction of database samples. However, the application of robotic extraction to forensic casework samples is a more daunting task. Such a system must be versatile enough to accommodate a wide range of samples that may contain greatly varying amounts of DNA, but it must also pose no more risk of contamination than the manual DNA extraction methods. This study demonstrates that the BioMek 2000 Laboratory Automation Workstation, used in combination with the DNA IQ System, is versatile enough to accommodate the wide range of samples typically encountered by a crime laboratory. The use of a silica coated paramagnetic resin, as with the DNA IQ System, facilitates the adaptation of an open well, hands off, robotic system to the extraction of casework samples since no filtration or centrifugation steps are needed. Moreover, the DNA remains tightly coupled to the silica coated paramagnetic resin for the entire process until the elution step. A short pre-extraction incubation step is necessary prior to loading samples onto the robot and it is at this step that most modifications are made to accommodate the different sample types and substrates commonly encountered with forensic evidentiary samples. Sexual assault (mixed stain) samples, cigarette butts, blood stains, buccal swabs, and various tissue samples were successfully extracted with the BioMek 2000 Laboratory Automation Workstation and the DNA IQ System, with no evidence of contamination throughout the extensive validation studies reported here.

Automation↗

The 'nasal pool' device applies controlled concentrations of solutes on human nasal airway mucosa and samples its surface exudations/secretions.

A 'nasal pool' (NP) device, a compressible plastic container with an adapted nozzle, was used to perform a continuous 10-min nasal provocation and lavage. This novel technique brings known concentrations of agents into contact with a large and defined area of the nasal mucosal surface for extended periods of time. Simultaneously, the surface exudations/secretions of the same nasal mucosa are effectively sampled by the NP fluid. A concentration-response study of histamine (80, 400 and 2000 micrograms/ml) was performed in 12 normal subjects on three different occasions. Exudation of plasma albumin into the lavage fluid was measured to quantitate the histamine-induced airway inflammation. The effect of the dwell time on exudation was examined using histamine (400 micrograms/ml) instilled in the nasal cavity for time periods from 10 sec to 10 min. The time course of histamine-induced plasma exudation response was studied by exposing the mucosa to histamine (400 micrograms/ml) for 12 min, with the NP renewed every minute. Allergen-provocations were performed in subjects with hay fever and TAME-esterase activity in the returned lavage fluid was determined to indicate the degree of response. Histamine produced a concentration-dependent increase in albumin levels in the NP fluid; 123.3 +/- 25.6, 213.8 +/- 19.7 and 430.2 +/- 32.0 micrograms/ml (mean +/- s.e.m.), respectively. The time-course study demonstrated that plasma exudation into the lumen occurred promptly and that the exudation response reached a maximum after exposure to histamine for 6-10 min. The dwell-time experiments supported this finding. After 10 min the exudation appeared to decline despite the continued presence of histamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Adaptive optimization and the harvest of biological populations.

Adaptive management of renewable biotic resources accounts explicitly for uncertainties in system responses to management and recognizes the importance of reducing uncertainties while pursuing other management goals. An adaptive approach to the harvest of wildlife populations that are subject to (1) uncontrollable environmental variation, (2) uncertainties about the appropriate characterization of resource dynamics, (3) limitations on the controllability of harvest rates, and (4) uncertainties as to population status, expressed as sampling variation in the monitoring of populations and habitats, is described. Adaptive management is framed in terms of maximizing long-term harvest value against a background of various kinds and degrees of uncertainty, with an emphasis on structural uncertainty. By an appropriate extension of the "system state," adaptive optimization can be defined in terms of Markov decision processes. Solution algorithms are described for systems that are subject to structural uncertainty and are either partially or completely observable. Adaptive optimization is illustrated with an example in waterfowl harvest management that incorporates uncertainty in the relationship between harvest rates and survivorship.

Animals↗

Risk factors for eating disorders in Greek- and Anglo-Australian adolescent girls.

Past research indicates ethnicity may be related to eating disorder and related risk factors. The present study examines risk factors for eating disorders in 50 Anglo- and 50 Greek-Australian girls (mean age = 13.5 years). The variables assessed included bulimic tendencies, body dissatisfaction, use of extreme weight loss behaviors (EWLBs), self-esteem, depression and family cohesion and adaptability. Cultural eating patterns were also explored. A stepwise discriminant function analysis to examine whether the two groups could be discriminated on these variables was significant and correctly classified 73.9% of the sample, the chief discriminating variables being Pressure to Eat, EWLBs, and Family Adaptability. Univariate analyses indicated differences between the groups on Pressure to Eat, Family Adaptability, and Mother's Shape. Although the groups were discriminable, a number of variables generally associated with eating disorder did not contribute to the function. These data are discussed in terms of cultural assimilation.

Adolescent↗

Finding the genes underlying adaptation to hypoxia using genomic scans for genetic adaptation and admixture mapping.

The complete sequencing the human genome and recent analytical advances have provided the opportunity to perform genome-wide studies of human variation. There is substantial potential for such population-genomic approaches to assist efforts to uncover the historical and demographic histories of human populations. Additionally, these genome-wide datasets allow for investigations of variability among genomic regions. Although all genomic regions in a population have experienced the same demographic events, they have not been affected by these events in precisely the same way. Much of the variability among genomic regions is simply the result of genetic drift (i.e., gene frequency changes resulting from the effects of small breeding-population size), but some is also the result of genetic adaptation, which will only affect the gene under selection and nearby regions. We have used a new DNA typing assay that allows for the genotyping of thousands of SNPs on hundreds of samples to identify regions most likely to have been affected by genetic adaptation. Populations that have inhabited different niches (e.g., high-altitude regions) can be used to identify genes underlying the physiological differences. We have used two methods (admixture mapping and genome scans for genetic adaptation) founded on the population-genomic paradigms to search for genes underlying population differences in response to chronic hypoxia. There is great promise that together these methods will facilitate the discovery of genes influencing hypoxic response.

Alleles↗

Some adaptive monte carlo methods for Bayesian inference.

Monte Carlo methods, in particular Markov chain Monte Carlo methods, have become increasingly important as a tool for practical Bayesian inference in recent years. A wide range of algorithms is available, and choosing an algorithm that will work well on a specific problem is challenging. It is therefore important to explore the possibility of developing adaptive strategies that choose and adjust the algorithm to a particular context based on information obtained during sampling as well as information provided with the problem. This paper outlines some of the issues in developing adaptive methods and presents some preliminary results.

Algorithms↗

Quantitative polymerase chain reaction with enzyme-linked immunosorbent assay detection of selectively digested amplified sample and control DNA.

A quantitative polymerase chain reaction (PCR) method for the exact quantitation of DNA is described that does not require radioactive labeling or electrophoretic separation of product species, thereby avoiding hazardous and time-consuming procedures which have so far impeded routine use of PCR, in particular in the clinical laboratory. Sample and internal control DNA are competitively amplified in a one-tube nested PCR. The control DNA differs from the sample DNA by only two base pairs which change a single restriction site for a new one. Thereby, it is possible to discriminate the two PCR product species by selective restriction enzyme digestion (RED). Because inner PCR primers were labeled with biotin and digoxigenin, respectively, nested PCR products can be immobilized on avidin-coated microtiter plates and quantitated separately by enzyme-linked immunosorbent assay (ELISA) techniques. We demonstrate here that with the combination of selective restriction enzyme digestion and ELISA (RED-ELISA) sample DNA ranging from nanomolar to attomolar concentrations can be quantitated within +/- 10%. This procedure can be easily adapted for quantitation of other PCR products. It is suitable for rapid and automatic screening of many samples in parallel, e.g., for detection and quantitation of pathogens, for quantitation of gene copy numbers or for gene expression after reverse transcription.

Base Sequence↗

The Relationship Among Range Adaptation, Social Anhedonia, and Social Functioning: A Combined Magnetic Resonance Spectroscopy and Resting-State fMRI Study.

BACKGROUND AND HYPOTHESIS: Social anhedonia is a core feature of schizotypy and correlates significantly with social functioning and range adaptation. Range adaptation refers to representing a stimulus value based on its relative position in the range of pre-experienced values. This study aimed to examine the resting-state neural correlates of range adaptation and its associations with social anhedonia and social functioning. STUDY DESIGN: In study 1, 60 participants completed resting-state magnetic resonance spectroscopy and fMRI scans. Range adaptation was assessed by a valid effort-based decision-making paradigm. Self-reported questionnaires was used to measure social anhedonia and social functioning. Study 2 utilized 26 pairs of participants with high (HSoA) and low levels of social anhedonia (LSoA) to examine the group difference in range adaptation's neural correlates and its relationship with social anhedonia and social functioning. An independent sample of 40 pairs of HSoA and LSoA was used to verify the findings. STUDY RESULTS: Study 1 showed that range adaptation correlated with excitation-inhibition balance (EIB) and ventral prefrontal cortex (vPFC) functional connectivity, which in turn correlating positively with social functioning. Range adaptation was specifically determined by the EIB via mediation of ventral-medial prefrontal cortex functional connectivities. Study 2 found HSoA and LSoA participants exhibiting comparable EIB and vPFC connectivities. However, EIB and vPFC connectivities were negatively correlated with social anhedonia and social functioning in HSoA participants. CONCLUSIONS: EIB and vPFC functional connectivity is putative neural correlates for range adaptation. Such neural correlates are associated with social anhedonia and social functioning.

Humans↗

Characterization of chemotactic activity produced in vivo by a cell-mediated immune reaction in the guinea pig.

A system that allows repeated sampling of peritoneal fluid at various time intervals has been adapted to study mechanisms of leukocyte accumulation in vivo. Application of this technique in guinea pigs exhibiting delayed hypersensitivity (DH) to horse radish peroxidase (HRPO) has allowed characterization of some events after i.p.challenge with the sensitizing antigen. Within 24 hr of the administration of HRPO i.p. to such animals there is a significant increase in the number of peritoneal macrophages and in the chemotactic activity (CTX) for macrophages in the sampled peritoneal fluid. At 48 and 72 hr the CTX returns to the pre-challenge level and i.p. macrophages appear to be actively phagocytic. Molecular sieve chromatograms of concentrated peritoneal fluid obtained 24 hr after i.p. challenge with HRPO and of supernatants derived from immune spleen cells cultured in the presence of HRPO in the presence of HRPO in vitro revealed that the major portion of CTX for homologous macrophages eluted in the region of the 12,500 dalton protein marker. The partially purified CTX obtained from peritoneal fluid and supernatants of spleen cell cultures was heat stable (56 degrees C for 30 min) and was destroyed by trypsin digestion. These data demonstrate that a chemotactic factor (LDCF) obtained in vitro, is present in vivo at the site of a cell-mediated immune reaction. Moreover, these observations demonstrate the feasibility of studying the kinetics of leukocyte accumulation and the production of mediators of inflammation at the site of well defined immunologic reactions in vivo.

Animals↗