[ON THE PREDICTIONS OF ADAPTATION PATTERNS OF EX-PUPILS].
Explore the source record for details and available documents.
Adaptation, Physiological↗
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.
The construct and predictive validity of adaptive behavior.
The construct and predictive validity of adaptive behavior of mentally retarded persons was investigated using a multitrait multimethod analysis. The validity issues of concern were (a) how generalizable the adaptive behavior dimension is over a variety of measurement methods, (b) how adaptive behavior relates to mental age (MA), and (c) how well adaptive behavior assessment references placement in programs and situations. Adaptive behavior and MA were assessed by program participation, psychometric ratings, and overall staff ratings. Adaptive behavior had high convergent validity and low discriminant validity and predicted MA program placement better than did MA. We concluded that adaptive behavior scores could replace MA.
Adaptation, Psychological↗
Contributions of leisure participation in predicting stress coping and health among police and emergency response services workers.
This study examined the extent to which frequency and enjoyment measures of leisure participation predict adaptational outcomes, over and above the contributions of general coping. Police and emergency response services workers (N = 132) participated in the study, and a repeated measures design was used. The study provides evidence that the type of leisure activity matters in predicting immediate adaptational outcomes (coping effectiveness, coping satisfaction and stress reduction) and mental and physical health. Relaxing leisure was found to be the strongest positive predictor of coping with stress, while social leisure and cultural leisure significantly predicted greater mental or physical health.
Adaptation, Psychological↗
Are arm trajectories planned in kinematic or dynamic coordinates? An adaptation study.
There are several invariant features of point-to-point human arm movements: trajectories tend to be straight, smooth, and have bell-shaped velocity profiles. One approach to accounting for these data is via optimization theory; a movement is specified implicitly as the optimum of a cost function, e.g., integrated jerk or torque change. Optimization models of trajectory planning, as well as models not phrased in the optimization framework, generally fall into two main groups-those specified in kinematic coordinates and those specified in dynamic coordinates. To distinguish between these two possibilities we have studied the effects of artificial visual feedback on planar two-joint arm movements. During self-paced point-to-point arm movements the visual feedback of hand position was altered so as to increase the perceived curvature of the movement. The perturbation was zero at both ends of the movement and reached a maximum at the midpoint of the movement. Cost functions specified by hand coordinate kinematics predict adaptation to increased curvature so as to reduce the visual curvature, while dynamically specified cost functions predict no adaptation in the underlying trajectory planner, provided the final goal of the movement can still be achieved. We also studied the effects of reducing the perceived curvature in transverse movements, which are normally slightly curved. Adaptation should be seen in this condition only if the desired trajectory is both specified in kinematic coordinates and actually curved. Increasing the perceived curvature of normally straight sagittal movements led to significant (P < 0.001) corrective adaptation in the curvature of the actual hand movement; the hand movement became curved, thereby reducing the visually perceived curvature. Increasing the curvature of the normally curved transverse movements produced a significant (P < 0.01) corrective adaptation; the hand movement became straighter, thereby again reducing the visually perceived curvature. When the curvature of naturally curved transverse movements was reduced, there was no significant adaptation (P > 0.05). The results of the curvature-increasing study suggest that trajectories are planned in visually based kinematic coordinates. The results of the curvature-reducing study suggest that the desired trajectory is straight in visual space. These results are incompatible with purely dynamic-based models such as the minimum torque change model. We suggest that spatial perception--as mediated by vision--plays a fundamental role in trajectory planning.
Adaptation, Physiological↗
Coping and cognitive factors in adaptation to in vitro fertilization failure.
Characteristics were identified that predict adaptation following an unsuccessful attempt at in vitro fertilization (IVF). Forty-one women and their husbands were interviewed and administered questionnaires prior to IVF and 2 weeks after notice of a positive or negative pregnancy test. Of the 36 couples who failed to conceive as a result of IVF, 6 of the women studied developed clinical depressive symptoms. Those women who reported poorest adaptation to IVF failure were more likely to have reported depressive symptoms prior to IVF, were more likely to have reported feeling a general loss of control over their lives as a result of infertility, tended to use escape as a coping strategy, and reported having felt some responsibility for their IVF failure. Dispositional optimism, as well as a sense of being partially responsible for the infertility, was protective of distress following IVF failure.
Adaptation, Psychological↗
Caregivers' expectations of future learning of dependents with a developmental disability.
Attitudes and expectations of caregivers affect the development of children, including those with a developmental disability. The purpose of this study was to examine caregivers' expectations of their dependent with a developmental disability and caregiver attributions in relation to these expectations. Primary caregivers (N = 35) were interviewed about their expectations and attributions related to the dependents' achievements. Expectations were measured by the Predictive Adaptive Ability Questionnaire (PAAQ). Expectations were significantly predicted by the degree of developmental delay and number of handicaps. Caregivers expected less of dependents who had a lower developmental age/chronological age ratio than for dependents whose developmental level more closely approximated the chronological age. Results suggest that nurses should assess caregivers' expectations for the future development of their dependent with a developmental disability and the basis for those expectations.
Adolescent↗
Adaptive seasonal trend in brood sex ratio: test in two sister species with contrasting breeding systems.
Evolutionary theory predicts adaptive adjustment in offspring sex ratio by females. Seasonal change in sex ratio is one possibility, tested here in two sister species, the Common sandpiper and the Spotted sandpiper Actitis hypoleucos and A. macularia. In the monogamous Common sandpiper, males are the most competitive sex. In each of 3 years, there was a change from mainly sons in early clutches to mainly daughters in late clutches. This seasonal adjustment of clutch sex ratio took place within the female before the eggs were laid, not by differential egg or chick survival. The sex of all eggs laid in the clutches used here was determined molecularly from chick blood taken at the time of hatching. The Spotted sandpiper in contrast is polyandrous, with partly reversed sex roles. There was no seasonal trend from sons to daughters in this species. When tested together, the two species differed significantly as predicted by the hypothesis of adaptive sex ratio adjustment by females.
Adaptation, Biological↗
Experimental evaluation of the relationship between lethal or non-lethal virulence and transmission success in malaria parasite infections.
BACKGROUND: Evolutionary theory suggests that the selection pressure on parasites to maximize their transmission determines their optimal host exploitation strategies and thus their virulence. Establishing the adaptive basis to parasite life history traits has important consequences for predicting parasite responses to public health interventions. In this study we examine the extent to which malaria parasites conform to the predicted adaptive trade-off between transmission and virulence, as defined by mortality. The majority of natural infections, however, result in sub-lethal virulent effects (e.g. anaemia) and are often composed of many strains. Both sub-lethal effects and pathogen population structure have been theoretically shown to have important consequences for virulence evolution. Thus, we additionally examine the relationship between anaemia and transmission in single and mixed clone infections. RESULTS: Whereas there was a trade-off between transmission success and virulence as defined by host mortality, contradictory clone-specific patterns occurred when defining virulence by anaemia. A negative relationship between anaemia and transmission success was found for one of the parasite clones, whereas there was no relationship for the other. Notably the two parasite clones also differed in a transmission phenotype (gametocyte sex ratio) that has previously been shown to respond adaptively to a changing blood environment. In addition, as predicted by evolutionary theory, mixed infections resulted in increased anaemia. The increased anaemia was, however, not correlated with any discernable parasite trait (e.g. parasite density) or with increased transmission. CONCLUSIONS: We found some evidence supporting the hypothesis that there is an adaptive basis correlating virulence (as defined by host mortality) and transmission success in malaria parasites. This confirms the validity of applying evolutionary virulence theory to biomedical research and adds support to the prediction that partially effective vaccines may select for increasingly virulent malaria parasite strains. By contrast, there was no consistent correlation between transmission and sub-lethal anaemia, a more common outcome of malaria infection. However, overall, the data are not inconsistent with the recent proposal that sub-lethal effects may impose an upper limit on virulence. Moreover, clone specific differences in transmission phenotypes linked to anaemia do suggest that there is considerable adaptive potential relating anaemia and transmission that may lead to uncertain consequences following intervention strategies.
Adaptation, Physiological↗
Coping behavior and intelligence in the prediction of vocational rehabilitation of dialysis patients.
As part of an intensive psychiatric and psychological examination before starting hemodialysis, forty-seven patients with terminal renal failure, thirty-one men and sixteen women with an age range from the late teens to the mid fifties, had been administered with WBII and the Shanan Sentence Completion technique. The hypothesis was that coping style would predict adaptation to hemodialysis as assessed by vocational rehabilitation. Intelligence, level of education, and the tendency to perceive sources of conflict in the outer world rather than within oneself, were found predictive of subseuqent adaptations for the whole group. On all these variables, men and women showed different patterns of significant correlations between the different aspects of coping and vocational rehabilitation. Subsequent multiple step-wise regression showed women (percentage of explained variance: 75) to be more predictable than men (40%) with different variables contributing differentially to predictability. These findings, interpreted to support the general working hypothesis, are discussed in terms of their implications for treatment.
Adaptation, Psychological↗
Prediction of pulmonary function in wheelchair users.
As a result of the improved medical treatment of infectious diseases, these formerly leading causes of mortality in the United States have been supplanted in rank by chronic events as the major causes of death. The major causes include coronary artery disease, respiratory disease, and cancer. Static and dynamic pulmonary functions in the apparently healthy wheelchair user population were measured and then modelled using stepwise regression. One hundred and nine wheelchair users (97 males, 12 females) with paraplegia (n = 77) or quadriplegia (n = 32) gave informed consent and participated in this study. Subjects ranged from being Olympic caliber wheelchair marathon racers to those who live sedentary life styles. Subjects performed three slow vital capacity (SVC) tests, three forced vital capacity (FVC) tests, and three maximal voluntary ventilation (MVV) tests while seated in their standard wheelchair. The order of the pulmonary function tests was randomized. Subjects also completed two functional residual capacity (FRC) measurements. Analysis of variance revealed significant differences in several pulmonary functions based on gender (FEVC, p = 0.0001, FEV1, p = 0.0001, FEVC 25-75%, p = 0.005, PEF, p = 0.002, FIVC, p = 0.002, RV, p = 0.0001, MVV, p = 0.0001, SVC, p = 0.001). The women's unforced prediction equations using age, height, weight did yield some significant correlations with predictions based upon ambulatory subjects. The men's unforced adapted prediction equations did reveal significant correlations with the validation group for FEVC (r = 0.66, p = 0.007), FEV1 (r = 0.62, p = 0.015), PIF (r = 0.95, p = 0.015), MVV (r = 0.57, p = 0.067), SVC (r = 0.69, p = 0.019), and RV (r = 0.67, p = 0.009). Pulmonary function in male wheelchair users should be predicted using equations which incorporate years with disability and level of impairment. Additional study is required to make any recommendations regarding women wheelchair users. However, study of pulmonary function in women should be made a priority. Pulmonary function is affected by the extent of physical impairment, and tends to decline as years with disability increase.
Adolescent↗
Optimism, promotion pride, and prevention pride as predictors of quality of life.
The relationship between optimism and two potential sources of optimistic beliefs--promotion pride (based on a history of success in promotion regulation) and prevention pride (based on a history of success in prevention regulation)--was explored. Optimism was more strongly related to promotion pride than prevention pride (controlling for neuroticism), consistent with past work showing that anticipating success increases eagerness motivation but decreases vigilance motivation. This suggests that the psychology of prevention regulators is not captured well by the existing literature on optimism. Although prevention pride does not predict self-reports of well-being, it does predict adaptive functioning independent of optimism, neuroticism, and promotion pride. Promotion pride uniquely predicted a sense of purpose in life or goal directedness. Both promotion and prevention pride predicted active coping. It is argued that promotion and prevention pride tell us something unique and important about the role of successful self-regulation in determining quality of life.
Achievement↗
Do bone ingrowth processes produce a globally optimized structure?
A topology optimization program was applied to test the hypothesis that bone adaptation to porous coated implants produces a structure which minimizes the global strain energy density. The program was used to predict the optimal material layout around a porous coated tibial component with multiple cones [Goldstein et al., Trans. 37th ORS, p. 92 (1991)]. The sensitivity of the predicted adaptation to analysis assumptions was assessed and the predicted bone ingrowth and apposition were compared with the experimental findings of Goldstein et al. The results showed that apposition occurred consistently at the cone tips regardless of analysis assumptions. The specific topology of apposition at the cone tips was most sensitive to the assumed loading conditions. A comparison with the experimental results for 11 subdivisions showed that the general predicted location of material agreed with the experimental results (R2 > or = 0.59). However, the program predicted a consolidated bone greater than 1000 microns in thickness at the cone tips, which differed from the porous bone structure found experimentally. This discrepancy was reflected in a refined comparison over 31 subdivisions which did not produce a significant correlation (R2 < or = 0.3). The program also predicted little ingrowth (< 6-7%), indicating that ingrowth past the first bead layer contributed little to the overall bone-implant interface layer stiffness. Based on these results, we conclude, within limitations of a two-dimensional analysis, that bone adaptation to porous coated implants does not produce a structure solely optimized to minimize the global strain energy density. We hypothesize that the final bone structure reflects the need to meet both mechanical and nutritional demands.
Adaptation, Physiological↗
Prediction of bone adaptation using damage accumulation.
The adaptation of bones to a change in function has been recognised for many centuries, but only recently have mathematical laws been proposed to describe it. One proposed mathematical law is based on the hypothesis that, after a change in load, the strain in the bone microstructure is regulated to a homeostatic equilibrium. Strain-adaptive remodelling has been used successfully to simulate bone adaptation around orthopaedic implants but the predictive capabilities are constrained because many empirical constants are required in the remodelling law (a reference stimulus, a zone of equilibrium stresses or 'lazy zone' and a parameter transducing macroscopic stresses to a tissue level stimulus). An alternative approach has been proposed. It is that bone adapts to attain an optimal strength by regulating the damage generated in its microstructural elements. The question is raised whether or not a mathematical law to predict the time course of bone adaptation can be derived for damage-adaptive remodelling in a similar way to the mathematical laws based on a strain stimulus. In the present study, the hypotheses required to develop damage-adaptive remodelling laws are proposed and a remodelling law to predict the time course of bone adaptation is derived. It is shown that this is an integral remodelling law which accounts naturally for the stress history to which the tissue has been exposed since formation. A simulation of the adaptive response of a bone diaphysis under a change in torsional load shows that the law gives physically reasonable predictions. The initial remodelling prediction is similar to strain-adaptive remodelling. However, in the later stages of remodelling, the predictions differ from strain-adaptive remodelling in that direct convergence to a homeostatic strain is not predicted. Instead, undershoot (in the case of a reduction in load) and overshoot (in the case of an increase in load) are predicted.
Adaptation, Physiological↗
A cerebellar model of timing and prediction in the control of reaching.
A simplified model of the cerebellum was developed to explore its potential for adaptive, predictive control based on delayed feedback information. An abstract representation of a single Purkinje cell with multistable properties was interfaced, using a formalized premotor network, with a simulated single degree-of-freedom limb. The limb actuator was a nonlinear spring-mass system based on the nonlinear velocity dependence of the stretch reflex. By including realistic mossy fiber signals, as well as realistic conduction delays in afferent and efferent pathways, the model allowed the investigation of timing and predictive processes relevant to cerebellar involvement in the control of movement. The model regulates movement by learning to react in an anticipatory fashion to sensory feedback. Learning depends on training information generated from corrective movements and uses a temporally asymmetric form of plasticity for the parallel fiber synapses on Purkinje cells.
Adaptation, Physiological↗
Tissue adaptation as a dynamical process far from equilibrium.
It is well established that tissue growth, maintenance, and degeneration are biochemically regulated processes influenced by mechanical function. Biomechanical models have been developed to predict adaptive processes; for example, computer simulation of bone remodeling around orthopaedic implants can accurately predict the effect of certain implant design variables. However, the same success remains to be achieved with other adaptive processes such as joint morphogenesis or osteoporosis. We propose that, to become capable of stimulating such adaptive processes, biomechanical models should capture the inherently irreversible nature of tissue adaptation and therefore should not rely on the assumption of a "homeostatic" equilibrium. In this article, it is proposed that tissue adaptation is an unstable process of moving between tissue states that are far from the equilibrium state--and that to simulate it, independent sensors and positive feedback stimuli should be employed.
Adaptation, Physiological↗
Lower-field myopia in birds: an adaptation that keeps the ground in focus.
In the lower visual field of pigeons, a myopia (near-sightedness) has been reported that progressively increases with the angle below the horizon. Previous data suggested that this lower-field myopia may be an adaptation that permits pigeons to keep the ground in focus while they forage, and simultaneously, to monitor the horizon and sky for predators. We report here a lower-field myopia in other species of birds that have a wide range of heights. A geometric model of this adaptation predicts that the amount of myopia should be systematically related to the distance from the pupil to the ground. The eyes of quail, chickens and cranes of various heights (7.0-104.1 cm) were refracted at 60 deg below the horizon. Their myopia was close to the predicted value at each height.
Adaptation, Physiological↗
Non-surgical factors in the correction of aphakia.
72 unselected patients wearing aphakic spectacle correction were examined more than 6 months postoperatively. Approximately one third had poor adaptation in spite of satisfactory acuity. No correlation with age was found in the 60-85 year range. Binocularity appeared to play no part in adaptation but a significant sex difference was found, females predominating in the non-adapted group. Tests of eye movements showed defects in vestibulo-ocular suppression, smooth pursuit, and saccadic accuracy in the non-adapted group. This may indicate floccular dysfunction as a reason for failure to adapt to aphakic spectacles. This suggests the possibility of a useful preoperative assessment test to predict adaptation difficulties.
Adaptation, Ocular↗
Predicting meningococcal disease outbreaks in structured populations.
Rational decision making on whether some form of intervention would be necessary to control the spread of a meningococcal epidemic is based on predictions concerning its potential natural progression. Unfortunately, reliable predictions are difficult to make during the early stages of an outbreak. A stochastic discrete time epidemic model was applied to adaptively predict the development of outbreaks of meningococcal disease in 'closed' populations such as military garrisons or boarding schools, which are further divided into subgroups called 'units'. The performance of the adaptive method was assessed by using 3 simulated epidemics representing substantially different realizations in a 'garrison' of 20 units, with 68 men in each. Predictions of the weekly number of disease cases, of the number of carriers, and of the number of new infections were computed. Simulations suggest that predictions based only on the observed numbers of disease cases are generally inaccurate. These predictions can be improved if temporal observations on asymptomatic carriers in different units are utilized together with observed time series of the disease. A sample of 15 per cent from all units can be sufficient for a major improvement if the alternative is to obtain a full sample of only some units. Exploiting fully such information requires computer intensive Markov chain Monte Carlo methods.
Disease Outbreaks↗