Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “predictability of adaptation”

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 1,621 records · Page 90Linked to original sources
PubMed1992

Mental retardation.

Mental retardation is defined using two criteria: intelligence quotient and adaptive functioning. Subclassification based on IQ is helpful in predicting outcome and determining educational program. Advances continue to be made in identifying specific medical causes of intellectual deficits. As the natural history of conditions such as fragile-X becomes better understood, treatment approaches based on medical diagnosis will likely evolve. Clinicians working with mentally retarded patients should pursue vigorously medical diagnosis because of its implications for genetic counseling, family management, and full recognition of other handicapping conditions which may affect the patient. Psychopathology in the mentally retarded resembles that in nonretarded individuals, but occurs more frequently. Treatment of psychiatric disorders must be individualized. Mildly and some moderately retarded persons can benefit from psychotherapy. Behavioral approaches, particularly applied behavior analysis, are the most effective treatment for specific aberrant behaviors. Pharmacotherapy should be based on psychiatric diagnosis. Medications may be used, together with behavioral interventions, to treat specific destructive behaviors, but the scientific support for such use is new and somewhat limited.

Adolescent↗
PubMed1991

[Informed consent and the physician-patient relations in thoracic oncology].

Medical ethics have always required patient consent as a prerequisit to therapy. The law concerning the "protection of persons accepting to be subjects in biomedical research" requires specific oral and written information to be given to all patients entering a clinic research project. New effects of the principal of "informed consent", on the physician-patient relationship, are analysed. Fifty patients with bronchial cancer were included in controlled studies from June 1989 to June 1990. These patients were asked to give their informed consent involving 5 different studies (2 Phase II studies investigating tolerance to a new treatment and 3 Phase III studies comparing a new treatment with a reference treatment). The patients were informed beforehand of the possibility of a research treatment and the legal requirement for their signature as well as to the possibilities of replacement solutions in case they refused. Detailed and adapted information concerning the different therapeutic solutions and their predictable side effects were presented before reading the informed consent statement. Of the 50 informed consent statements proposed, 49 were accepted. The principal of informed consent was favourably apprehended by the patients (active participation, notion of protection, information source, possibility of dialogue) and induced conditions of better acceptation by the patient. Nevertheless, it was more difficult to obtain statements of consent for studies comparing a new treatment with a reference treatment than for studies simply proposing a new treatment alone.

Adult↗
PubMedDate not supplied

Children's locus of control beliefs as predictors of preoperative coping behavior.

This study examined the relationship between children's locus of control beliefs (as measured by the Nowicki-Strickland Locus of Control Scale) and their preoperative coping behavior. Subjects were 51 children between the ages of 8 and 12 who were scheduled for minor elective surgery. They were interviewed and each child's mode of coping was classified along a dimension termed avoidant-active. The relationships between sex, socioeconomic status, other demographic variables, and the type of preoperative information given to the child by the parent and surgeon were also evaluated. Results showed that children rated as active copers had more internal locus of control scores than children rated as avoidant or as using a combination of avoidant-active coping modes. Children rated as active were given more detailed information about their medical problem and surgery than children rated as using avoidant or a combination of avoidant-active coping modes. Internal locus of control was significantly related to higher socioeconomic status but not to sex or other demographic variables. Regression analysis showed that parent-doctor information and locus of control were independently predictive of coping.

Adaptation, Psychological↗
PubMed1993

Worldwide demographics and future trends of the management of renal failure in the elderly.

Aging will be a serious social problem in the future. The number of patients of 75 years and over with end-stage renal disease (ESRD) is bound to increase. The time has come to pay greater attention to their problems before and during dialysis treatment. Prevention of ESRD is an important challenge, especially in the field of vascular diseases which are the main cause of ESRD in the elderly. The exact number of elderly patients who will require dialysis in the next few years is difficult to foresee. It is only when the incidence of patients starting dialysis at 75 and over levels off that we may assume that elderly patients are no longer rejected from treatment; we could then assess the actual need in dialysis facilities. In elderly dialysis patients, mortality remains high. Improvements in geriatric medicine and dialysis techniques should contribute to better results in future years. As it is almost impossible to predict the survival and how an elderly patient will adapt to treatment, it appears more ethical to propose a trial of dialysis treatment, except in cases of severe dementia or malignancy. This large acceptance rate implies admitting that withdrawal from dialysis must sometimes be considered.

Age Factors↗
PubMed1993

Intracellular cGMP concentration in rod photoreceptors is regulated by binding to high and moderate affinity cGMP binding sites.

cGMP is the second messenger for visual excitation in vertebrate rod photoreceptors. However, no direct correlation has been observed between the measured total cGMP concentration in the rod outer segment and the electrical response of these cells to photic stimulation. To address this discrepancy, we have quantitated the number and affinities of cGMP binding sites in the rod outer segment to determine the cytoplasmic free cGMP concentration that is involved in visual transduction. We identified two distinct classes of cGMP binding sites in amphibian rod outer segments: 1) high affinity binding sites with a KD1 = 60 nM and a site density of 30 microM, and 2) moderate affinity binding sites with a KD2 = 6.6 microM and a site density of 78 microM. These two classes of binding sites are calculated to bind 94% of the total cellular cGMP, thereby lowering the cytoplasmic cGMP concentration to 3.5 microM in dark-adapted rod outer segments. This value is consistent with predictions of the cytoplasmic cGMP concentration based on activation of the cGMP-gated ion channel of rod photoreceptors. The kinetics of cGMP dissociation from high affinity binding sites indicate that this class of sites would dissociate its bound cGMP too slowly to participate in visual excitation and recovery to flash illumination. This binding of cGMP to intracellular binding sites provides a non-enzymatic mechanism by which photoreceptor cells regulate the concentration and restrict the diffusion of this second messenger during visual transduction.

Animals↗
PubMed1993

Cerebral oxidative metabolism in fetal sheep with prolonged and graded hypoxemia.

Cerebral oxidative metabolism and associated circulatory responses were determined in 14 unanesthetized fetal sheep near term, during a normoxic control period and subsequently, during four days of prolonged and graded hypoxemia induced by progressively lowering maternal inspired oxygen concentration with 1-2% CO2 added; first day 18%, second day 16%, third day 12-14%, fourth day 10-12%. Preductal arterial and sagittal vein blood samples were analyzed for oxygen content, blood gas tensions and pH. Regional blood flow was measured with a microsphere technique. Cerebral blood flow increased in a stepwise manner with the graded reduction in fetal arterial O2 saturation and continued to be well predicted by blood gas and metabolic alterations, with no adaptive change evident. Cerebral oxidative metabolism remained little changed with chronically induced hypoxemia until arterial O2 saturation was less than 30% and with fetal acidemia evident when decreased to 70% of normoxic control values. Whether the decrease in oxidative metabolism by the brain at this time represents an adaptive response whereby growth and functional alterations lead to a decrease in nonessential energy utilization or rather a pathological change, remains to be determined.

Animals↗
PubMed1998

Preadolescent friendship and peer rejection as predictors of adult adjustment.

Although peer-rejected children appear to be at risk for later difficulties, the contribution of preadolescent friendship to adaptive adjustment lacks an empirical foundation. In this 12 year follow-up investigation, 30 young adults who had a stable, reciprocal best friend in fifth grade and 30 who had been chumless completed measures of adjustment in multiple domains. Friendship and peer rejection were found to have unique implications for adaptive development. Lower levels of preadolescent peer rejection uniquely predicted overall life status adjustment, whereas friended preadolescents had higher levels of general self-worth in adulthood even after controlling for perceived competence in preadolescence. In contrast, peer rejection and the absence of friendship were both associated with psychopathological symptoms in adulthood, although neither was uniquely predictive of symptomatology.

Adult↗
PubMed1986

Level discrimination of tones as a function of duration.

Difference limens for level [delta Ls (dB) = 20 log[p + delta p)/p), where p is the pressure] were measured as a function of duration for tones at 250, 500, and 8000 Hz. Stimulus durations ranged from 2 ms to 2 s, and the stimulus power was held constant. Rise and fall times were 1 ms. The interstimulus interval was 250 ms. At each frequency, three levels were tested: 85, 65, and approximately 40 dB SPL. An adaptive two-alternative forced-choice procedure with feedback was used. For three normal listeners, delta Ls decreased as duration increased, up to at least 2 s, except at 250 Hz. At 250 Hz, delta L stopped decreasing at durations between 0.5 and 1 s. In a double logarithmic plot of delta L versus duration, the rate of decrease is generally well fitted by a sloping line. The average slope is -0.28; it is steeper at high levels than at low levels. Because the average slope is shallower than the -0.5 slope predicted for an optimum detector, it may be that fast adaptation of auditory-nerve activity and/or memory effects interfere with level discrimination of long-duration tones. Finally, the delta Ls at 8 kHz decreased nonmonotonically with increasing level.

Adult↗
PubMed1999

The genome of Melanoplus sanguinipes entomopoxvirus.

The family Poxviridae contains two subfamilies: the Entomopoxvirinae (poxviruses of insects) and the Chordopoxvirinae (poxviruses of vertebrates). Here we present the first characterization of the genome of an entomopoxvirus (EPV) which infects the North American migratory grasshopper Melanoplus sanguinipes and other important orthopteran pests. The 236-kbp M. sanguinipes EPV (MsEPV) genome consists of a central coding region bounded by 7-kbp inverted terminal repeats and contains 267 open reading frames (ORFs), of which 107 exhibit similarity to previously described genes. The presence of genes not previously described in poxviruses, and in some cases in any other known virus, suggests significant viral adaptation to the arthropod host and the external environment. Genes predicting interactions with host cellular mechanisms include homologues of the inhibitor of apoptosis protein, stress response protein phosphatase 2C, extracellular matrixin metalloproteases, ubiquitin, calcium binding EF-hand protein, glycosyltransferase, and a triacylglyceride lipase. MsEPV genes with putative functions in prevention and repair of DNA damage include a complete base excision repair pathway (uracil DNA glycosylase, AP endonuclease, DNA polymerase beta, and an NAD+-dependent DNA ligase), a photoreactivation repair pathway (cyclobutane pyrimidine dimer photolyase), a LINE-type reverse transcriptase, and a mutT homologue. The presence of these specific repair pathways may represent viral adaptation for repair of environmentally induced DNA damage. The absence of previously described poxvirus enzymes involved in nucleotide metabolism and the presence of a novel thymidylate synthase homologue suggest that MsEPV is heavily reliant on host cell nucleotide pools and the de novo nucleotide biosynthesis pathway. MsEPV and lepidopteran genus B EPVs lack genome colinearity and exhibit a low level of amino acid identity among homologous genes (20 to 59%), perhaps reflecting a significant evolutionary distance between lepidopteran and orthopteran viruses. Divergence between MsEPV and the Chordopoxvirinae is indicated by the presence of only 49 identifiable chordopoxvirus homologues, low-level amino acid identity among these genes (20 to 48%), and the presence in MsEPV of 43 novel ORFs in five gene families. Genes common to both poxvirus subfamilies, which include those encoding enzymes involved in RNA transcription and modification, DNA replication, protein processing, virion assembly, and virion structural proteins, define the genetic core of the Poxviridae.

Amino Acid Sequence↗
PubMed2003

Learning myopia: an adaptive recency effect in category learning.

Recency effects (REs) have been well established in memory and probability learning paradigms but have received little attention in category earning research. Extant categorization models predict REs to be unaffected by learning, whereas a functional interpretation of REs, suggested by results in other domains, predicts that people are able to learn sequential dependencies and incorporate this information into their responses. These contrasting predictions were tested in 2 experiments involving a classification task in which outcome sequences were autocorrelated. Experiment 1 showed that reliance on recent outcomes adapts to the structure of the task, in contrast to models' predictions. Experiment 2 provided constraints on how sequential information is learned and suggested possible extensions to current models to account for this learning.

Attention↗
PubMed2003

Alternative approaches to predicting methane emissions from dairy cows.

Previous attempts to apply statistical models, which correlate nutrient intake with methane production, have been of limited value where predictions are obtained for nutrient intakes and diet types outside those used in model construction. Dynamic mechanistic models have proved more suitable for extrapolation, but they remain computationally expensive and are not applied easily in practical situations. The first objective of this research focused on employing conventional techniques to generate statistical models of methane production appropriate to United Kingdom dairy systems. The second objective was to evaluate these models and a model published previously using both United Kingdom and North American data sets. Thirdly, nonlinear models were considered as alternatives to the conventional linear regressions. The United Kingdom calorimetry data used to construct the linear models also were used to develop the three nonlinear alternatives that were all of modified Mitscherlich (monomolecular) form. Of the linear models tested, an equation from the literature proved most reliable across the full range of evaluation data (root mean square prediction error = 21.3%). However, the Mitscherlich models demonstrated the greatest degree of adaptability across diet types and intake level. The most successful model for simulating the independent data was a modified Mitscherlich equation with the steepness parameter set to represent dietary starch-to-ADF ratio (root mean square prediction error = 20.6%). However, when such data were unavailable, simpler Mitscherlich forms relating dry matter or metabolizable energy intake to methane production remained better alternatives relative to their linear counterparts.

Animal Feed↗
PubMed1989

Molecular basis of evolutionary adaptation at the lactate dehydrogenase-B locus in the fish Fundulus heteroclitus.

At the extremes of its natural distribution, populations of the common killifish Fundulus heteroclitus experience a difference of more than 15 degrees C in mean annual temperature. These populations are virtually fixed for two different codominant alleles at the heart-type lactate dehydrogenase locus (Ldh-B) which code for allozymes with different and adaptive kinetic responses to temperature. Two populations near the extremes of the species range (i.e., Maine and Georgia) were further studied for thermal adaptation at this locus. In the absence of any kinetic differences one would predict that to maintain a constant reaction velocity, 2 to 3 times as much enzyme would be required for each 10 degrees C decrease in environmental temperature. Consistent with this adaptive strategy and in addition to the adaptive kinetic characteristics, the LDH-B4 enzyme (EC 1.1.1.27) concentration and its mRNA concentration were approximately twice as great in the northern population as in the southern population. Acclimation experiments allow us to conclude that these differences are due to a combination of fixed genetic traits (evolutionary adaptation) and plastic responses to temperature (physiological acclimation). Furthermore, our calculations show that the LDH-B4 reaction velocities are essentially equivalent for these two populations, even though they live in significantly different thermal environments.

Adaptation, Physiological↗
PubMed2000

Prenatal maternal predictors of cognitive and emotional delays in children of adolescent mothers.

The present study examined relationships among prenatal characteristics of 121 adolescent mothers-including cognitive readiness for parenting, intelligence, social support, and personal adjustment-and intellectual-linguistic development, social-emotional functioning, and adaptive behavior in their children at three years of age. Only 28% of the children scored within normal ranges on all three types of outcomes. Intellectual and linguistic delays were predicted best by prenatal measures of maternal Performance IQ and social support from extended family. Socioemotional problems were predicted best by maternal internalizing problems and social support from partner and friends. Adaptive behavior was associated with parenting style. Implications for the early identification of high-risk children--and associated intervention programs--are discussed.

Adaptation, Psychological↗
PubMed2025

Eco-Evolutionary Genomics Reveal Mountain Range-Specific Adaptation and Intraspecific Variation in Vulnerability to Climate Change of Alpine Endemics.

Alpine plants restricted to rocky habitats exhibit intraspecific diversification due to range fragmentation during Holocene warming, complicating predictions of their climate vulnerability. A lack of understanding of eco-evolutionary mechanisms driving their response to climate change results in ineffective conservation efforts. To uncover the genomic basis of their diversification and explain spatial patterns of their vulnerability, we combine landscape genomics and species distribution modelling. Our model, the Campanula lehmanniana complex, occurs in three distinct central Asian mountain ranges, considered both a biodiversity hotspot and a vascular plant diversity darkspot. Genome-environment association confirmed the adaptive basis of intraspecific diversification, driven by numerous loci of small effect. Genomic and ecological data indicate mountain range-specific climate sensitivity driven by altitude, temperature and precipitation. The cold-dry adapted group from Zeravshan-Hissar Mts will face niche decline but show a higher degree of preadaptation to future climate, while the temperate-humid group from Tian Shan shows an opposite response, with a higher risk of maladaptation despite predicted niche expansion. Maladapted populations at northern margins may require an influx of adaptive variation to cope with predicted changes. However, limited landscape connectivity between island-like habitats, combined with long migration distances required to minimise genotype-environment disruption, highlights the role of human-assisted migration in enabling evolutionary rescue. These results underscore the need to facilitate gene flow from pre- to maladapted populations and the importance of population-specific approaches to inform effective conservation strategies in heterogeneous mountain ecosystems. The results may be relevant to numerous Central Asian mountain species that show similar phylogeographic patterns.

Climate Change↗
PubMed1998

Modelling motion sickness and subjective vertical mismatch detailed for vertical motions.

In an attempt to predict the amount of motion sickness given any kind of motion stimulus, we describe a model using explicit knowledge of the vestibular system. First, the generally accepted conflict theory is restated in terms of a conflict between a vertical as perceived by the sense organs like the vestibular system and the subjective vertical as determined on the basis of previous experience. Second, this concept is integrated with optimal estimation theory by the use of an internal model. If detailed for vertical motions only, the model does predict typical observed motion sickness characteristics, irrespective the parameter setting. By adjusting the nonvestibular parameters, the model can also quantitatively be adapted to seasickness data from the literature. With this concept, sickness severity hypothetically can also be predicted for other motions, irrespective of their origin and complexity.

Conflict, Psychological↗
PubMed1981

A fit mouse is a hoppy mouse: jumping behavior in 15-day-old Mus musculus.

An analysis of a juvenile hopping response from an 8 X 8 diallel cross is used to demonstrate the experimental genetic approach for testing presumed adaptive fitness of behaviors in developing organisms. In accordance with predictions, the explosive jumping behavior exhibited by 15-day mice is characterized by a pattern of genetic dominance toward high expression of the trait. Wild mice show even more vigorous responses, indicating that selection pressures maintaining high responding have been relaxed during domestication. These data suggest some applications and limitations of genetic methods for the study of behavioral evolution as related to development.

Adaptation, Biological↗
PubMed1979

Circumplex model of marital and family systems: III. Empirical evaluation with families.

This study was designed to test the circumplex model of family systems that hypothesizes moderate family cohesion and moderate adaptability to be more functional than either extreme. Thirty-one Catholic family triads with daughters ranging in age from 14 to 17 years participated in a structured family interaction game (SIMFAM) and filled out questionnaires that measured the variables of cohesion and adaptability and the facilitative variables of support and creativity. All families were considered normal but were subdivided into those that had more and less difficulty with this adolescent. Analysis of the data yielded considerable support for the circumplex model. High family functioning was associated with moderate family cohesion and adaptability, and low family functioning had extreme scores on these dimensions. As predicted, high family support and creativity were also related to high family functioning. Implications of these findings for family therapy are discussed.

Adaptation, Psychological↗
PubMed2006

Evidence at hand: Diversity, functional implications, and locomotor prediction in intrinsic hand proportions of diprotodontian marsupials.

Knowledge about the diversity, locomotor adaptations, and evolution of the marsupial forelimb is limited, resulting in an underrepresentation of marsupials in comparative anatomical literature on mammalian forelimb anatomy. This study investigated hand proportions in the diverse marsupial order Diprotodontia. Fifty-two measurements of 95 specimens representing 47 species, as well as 6 non-diprotodontian specimens, were explored using principal components analysis (PCA). Bootstrapping was used to assess the reliability of the loadings. Phylogenetically independent contrasts and phylogenetic ANOVA were used to test for correlation with size and functional adaptation of forelimbs for locomotor habit, scored as arboreal vs. terrestrial. Analysis of first principal component (PC1) scores revealed significant differences between arboreal and terrestrial species, and was related to relative slenderness of their phalangeal elements. Both locomotor groups displayed allometry along PC1 scores, but with different intercepts such that PC1 discriminated between the two locomotor habits almost completely. PC2 separated some higher-level clades and burrowing species. Analysis of locomotor predictors commonly applied by palaeontologists indicates that ratios between proximal and intermediate phalanges were unsuitable as predictors of arboreality/terrestriality, but the phalangeal index was more effective. From PCA results, a phalangeal slenderness ratio was developed which proved to be a useful discriminator, suggesting that a single unallocated phalanx can be used for an impression of locomotor mode in fossils. Most Diprotodontia are laterally paraxonic or ectaxonic, with the exception of digging species whose hands are medially paraxonic. Our results complement those of studies on placental mammals, suggesting that the demands of arboreality, terrestriality, or frequent digging on intrinsic hand proportions are met with similar anatomical adaptations in marsupials.

Adaptation, Physiological↗