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PubMed1997

Linguistic predictors of adaptive bereavement.

The words people use in disclosing a trauma were hypothesized to predict improvements in mental and physical health in 2 studies. The first study reanalyzed data from 6 previous experiments in which language variables served as predictors of health. Results from 177 participants in previous writing studies showed that increased use of words associated with insightful and causal thinking was linked to improved physical but not mental health. Higher use of positive relative to negative emotion words was also associated with better health. An empirical measure that was derived from these data correlated with subsequent distress ratings. The second study tested these models on interview transcripts of 30 men who had lost their partners to AIDS. Cognitive change and empirical models predicted postbereavement distress at 1 year. Implications of using computer-based text analyses in the study of narratives are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Diffuse large B-cell lymphoma with overexpression of cyclin e substantiates poor standard treatment response and inferior outcome.

PURPOSE: Gold standard to predict survival and stratify patients for risk-adapted therapy in diffuse large B-cell lymphoma (DLBCL) is the international prognostic index, although it does not consider the molecular heterogeneity of DLBCL. Deregulation of cyclin E (CCNE) is a strong predictor of poor prognosis in some neoplastic diseases. In tumor cells, it induces chromosomal instability with an increased rate of aneuploidy/polyploidy. EXPERIMENTAL DESIGN: We analyzed in this retrospective study the prognostic value of immunohistochemical CCNE expression on a validated tissue microarray containing 101 de novo DLBCLs and, in 9 cases, the CCNE-induced chromosomal instability as assessed by cytometry. RESULTS: Forty-six of 98 evaluable DLBCLs expressed CCNE in a mean proportion of 20 +/- 29% of tumor cells; 38 cases expressed CCNE in >/=20% of tumor cells. CCNE-positive samples were aneuploid compared with near tetraploidy in CCNE-negative cases. Multivariate analysis showed CCNE expression in >/=20% of tumor cells to be an international prognostic index-independent, Adriamycin-based treatment-independent, and BCL2-independent prognostic factor for poor disease-specific survival. CCNE expression in >/=80% of tumor cells was associated with dismal short-term prognosis. CCNE expression in >/=50% of tumor cells emerged as an independent predictive factor for standard CHOP treatment resistance. CONCLUSIONS: CCNE expression assessment is easy on paraffin-embedded tissue. The high prognostic value of CCNE expression in DLBCL may be the basis for future prospective trials. In addition, a high CCNE expression hints at the presence of a possible target for individualized cancer therapy.

Aged↗
PubMed1980

Vocational status: prediction by the Barthel index and PULSES profile.

Functional assessment measures of patients in a rehabilitation hospital were used to predict vocational status 18 months after discharge. The Granger adapted version of the Barthel index and the PULSES profile were administered to 118 disabled persons at discharge. Their total scores were correlated with vocational status measured by a scale of 1 to 6, ranging from unemployment to full-time employment. Analysis of data reveals that the Barthel index and sex (female) predicted vocational status 18 months after discharge (p < 0.05). PULSES showed no significant correlation with vocational status. Further analysis indicates that in a stepwise regression of independent variables on vocational status, the best predictors were the Barthel index, sex (female), age (the younger are more likely to pursue a vocation), contacts with state rehabilitation counselor, and contacts with Tufts counselor. Further studies are needed to examine specific subgroups of the physically impaired population seen by medical centers and state rehabilitation agencies.

Adolescent↗
PubMed2003

Predicting crystal structures: the Parrinello-Rahman method revisited.

By suitably adapting a recent approach [A. Laio and M. Parrinello, Proc. Natl. Acad. Sci. U.S.A. 99, 12 562 (2002)]] we develop a powerful molecular dynamics method for the study of pressure-induced structural transformations. We use the edges of the simulation cell as collective variables and define a metadynamics that drives the system away from the local minimum towards a new crystal structure. In contrast to the Parrinello-Rahman method, our approach shows no hysteresis, and crystal structure transformations can occur at the equilibrium pressure. We illustrate the power of the method by studying the pressure-induced diamond to simple hexagonal phase transition in a model of silicon.

Journal Article↗
PubMedDate not supplied

A methodology for validating numerical ground water models.

Ground water validation is one of the most challenging issues facing modelers and hydrogeologists. Increased complexity in ground water models has created a gap between model predictions and the ability to validate or build confidence in predictions. Specific procedures and tests that can be easily adapted and applied to determine the validity of site-specific ground water models do not exist. This is true for both deterministic and stochastic models, with stochastic models posing the more difficult validation problem. The objective of this paper is to propose a general validation approach that addresses important issues recognized in previous validation studies, conferences, and symposia. The proposed method links the processes for building, calibrating, evaluating, and validating models in an iterative loop. The approach focuses on using collected validation data to reduce uncertainty in the model and narrow the range of possible outcomes. This method is designed for stochastic numerical models utilizing Monte Carlo simulation approaches, but it can be easily adapted for deterministic models. The proposed methodology relies on the premise that absolute validity is not theoretically possible, nor is it a regulatory requirement. Rather, the proposed methodology highlights the importance of testing various aspects of the model and using diverse statistical tools for rigorous checking and confidence building in the model and its predictions. It is this confidence that will encourage regulators and the public to accept decisions based on the model predictions. This validation approach will be applied to a model, described in this paper, dealing with an underground nuclear test site in rural Nevada.

Environmental Monitoring↗
PubMed1983

Spatial-frequency discrimination and detection: comparison of postadaptation thresholds.

We found that inspecting a sine-wave grating elevated threshold for spatial-frequency discrimination as it does for contrast detection, but discrimination threshold was maximally elevated at about twice the adapting frequency, where detection threshold was little affected; and detection threshold was maximally elevated at the adapting frequency, where discrimination threshold was not elevated at all. Orientation tuning was roughly similar for contrast and for discrimination threshold elevations; elevations fell by half at between 7 and 17 deg from the adapting orientation. We compared our findings with the predictions of three models of discrimination: (1) The data are inconsistent with the idea that the most strongly stimulated channels are the most important channels for discrimination. (2) With an additional assumption, the Hirsch-Hylton scaled-lattice model could account for our finding that discrimination threshold elevations are asymmetric. (3) With no additional assumptions, the idea that discrimination is determined by the relative activities of multiple overlapping spatial-frequency channels or size-tuned neurons can account for our finding that discrimination thresholds are asymmetric. We propose a physiologically based discrimination model: Asymmetrically tuned cortical cells feed a ratio-tuned neural mechanism whose properties are formally analogous to those of ratio-tuned neurons that have recently been found in cat visual cortex. The linear relation between firing frequency and contrast can explain why discrimination threshold is substantially independent of contrast.

Adaptation, Physiological↗
PubMed2026

Predictive evolutionary genomics: principles, validation, and practice.

Climate change and habitat loss are driving rapid evolutionary responses in populations world-wide, which creates an urgent need for evolutionary forecasting in conservation and agriculture. Such forecasting can be categorized into three time scales: trait-based models that use multivariate quantitative genetic equations to project correlated phenotypic responses up to c.&#xa0;20 generations, allele-based analyses that model allele frequency dynamics up to 100 generations, and composite adaptation scores that aggregate many small effects to yield predictions across longer horizons. However, these approaches have remained largely disconnected. Here, we present a Bayesian framework that integrates these three complementary approaches for evolutionary prediction. Our framework combines genomic, phenotypic, and environmental data to yield probabilistic predictions with explicit uncertainty. We show how predictive evolutionary forecasts can be validated with experimental evolution, field experimentation, historical specimens, and reciprocal transplants. These validated forecasts can help advance conservation and agricultural programmes by helping predict which populations are at risk of future extinction, optimizing breeding programmes for future climates, and planning ecosystem management under environmental change. By supporting a shift towards more predictive approaches in evolutionary biology, this framework may help improve our ability to manage biodiversity and food security in a changing world.

Genomics↗
PubMed1998

Near normalization of final height with adapted doses of growth hormone in Turner's syndrome.

An adapted GH dose regimen was evaluated in 14 untreated patients with Turner's syndrome. The initial GH dose (0.7 U/kg.BW) was increased by 0.7 U/kg.BW, up to a maximum of 2.1 U/kg.BW, when growth velocity (GV) declined to less than 200% of the pretreatment level. These patients were compared to a group of 17 patients with similar initial characteristics, who received a fixed dose of 0.9 U/kg.BW GH. Tolerance to both GH regimens was excellent. The adapted GH doses only partially prevented the waning effect observed with conventional doses of GH, and the initial goal of doubling GV was only achieved in 42% of the 112 patient-semesters. Doubling the GH dose from 0.7 to 1.4 U/kg.BW increased the GV by 1.6 +/- 1.8 cm/yr (P < 0.006); increasing the GH dose from 1.4 to 2.1 U/kg.BW increased GV by 0.8 +/- 1.3 cm/yr (P = NS). The overall height gain during the 4-yr trial was 25.6 +/- 3.9 cm in the adapted dose group and 21.8 +/- 3.9 cm in the conventional group (P < 0.02). Final height (FH) results were obtained in 12 of 14 patients in the adapted dose group and all 17 patients in the conventional group and compared to the predicted FH using Lyon's method. The estimated height benefit was 10.6 +/- 3.8 cm in the adapted dose group compared to 5.2 +/- 3.7 cm in the conventional group (P < 0.01). Eighty-three percent of the patients in the adapted dose group had an FH superior or equal to -2 SD score for the general population compared to 29% in the conventional group. In conclusion, a marked increment in the GH dose in girls with Turner's syndrome associated with a relatively late age at introduction of estrogen therapy brought 83% of the patients into the lower range of the normal height distribution of the general population.

Adolescent↗
PubMedDate not supplied

Conflicts of thermal adaptation and fever--a cybernetic approach based on physiological experiments.

Cold adaptation aims primarily at a better economy, i.e., preservation of energy often at the cost of a lower mean body temperature during cold stress, whereas heat adaptation whether achieved by exposure to a hot environment or by endogenous heat produced by muscle exercise, often brings about a higher efficiency of control, i.e., a lower mean body temperature during heat stress, at the cost of a higher water loss. While cold adaptation is beneficial in a cold environment, it may constitute a detrimental factor for exposure to a hot environment, mainly because of morphological adaptation. Heat adaptation may be maladaptive for cold exposure, mainly because of functional adaptation. Heat adaptation clearly is best suited to avoid higher body temperatures in fever, no matter which environmental conditions prevail. On the other hand, cold adaptation is detrimental for coping with fever in hot environment. Yet, in the cold, preceding cold adaptation may, because of reduced metabolic heat production, result in lower febrile increase of body temperature. Apparently controversial effects and results may be analyzed in the framework of a cybernetic approach to the main mechanisms of thermal adaptation and fever. Morphological adaptations alter the properties of the heat transfer characteristics of the body ("passive system"), whereas functional adaptation and fever concern the subsystems of control, namely sensors, integrative centers and effectors. In a closed control-loop the two types of adaptation have totally different consequences. It is shown that the experimental results are consistent with the predictions of such an approach.

Acclimatization↗
PubMed1999

Convergence of cognitive and adaptive decline in late-life schizophrenia.

Cognitive impairment has proven to be a major predictor of overall functional deficit in schizophrenia. Despite the significant impairments seen on the part of many patients with schizophrenia that implicate decline at some point in time, there have been no longitudinal studies of adaptive decline in patients with schizophrenia. In this study, 57 geriatric patients with chronic schizophrenia were examined with measures of clinical symptoms, cognitive impairments, and adaptive functioning while living in a chronic psychiatric hospital and followed up an average of two and a half years after their referral to nursing home care. Cognitive functioning and adaptive functioning both declined over the follow-up period, whereas there was no change in schizophrenic symptoms. Changes in cognitive functioning accounted for 25% of the variance in adaptive decline, whereas the baseline severity of cognitive impairment and schizophrenia symptoms were uncorrelated with adaptive decline. These data indicate that cognitive decline may predict deterioration in overall functional status and imply that treatment of cognitive impairment might have a beneficial effect on global functional status.

Adaptation, Psychological↗
PubMed1998

The predictive value of developmental testing of extremely jaundiced African infants.

The predictive value of the Neonatal Neurological Examination (NNE) adapted from Prechtl (1977) and the Infant Motor Screen (IMS) from Nickel (1989) at 4 months was studied in severely jaundiced infants in Zimbabwe. Fifty infants were examined with the NNE, 41 with the IMS and 43 with the Bayley Scales of Infant Development (BSID) (Bayley 1969). Five infants had choreoathetosis and six had a motor delay at age 1 year. The NNE and IMS proved to be sensitive instruments particularly when two infants who became malnourished after the neonatal period were excluded. Logistic regression was used to investigate the relation between the BSID and five selected predictors from the NNE. This resulted in a correct classification of 93%. By using only the predictors acoustic blink and traction response, 80% of the infants were correctly classified but the number of false negatives was reduced from three to one.

Black People↗
PubMed2006

Antecedents and concomitants of parenting stress in adolescent mothers in foster care.

OBJECTIVE: This study's aim was to examine variables associated with different short-term trajectories in multiply disadvantaged adolescent mothers by investigating antecedents and concomitants of parenting stress. METHOD: We followed 49 adolescent mothers (ages 14-18 at study outset) who were wards in Illinois foster care using a longitudinal correlational design. We examined whether parenting variables (childrearing beliefs, quality of parent-child interactions, and child abuse risk) and personal adjustment variables (emotional distress and social support) at initial assessment predicted parenting stress measured at follow-up (a mean of 22.5 months later). We also examined concurrent relationships between parenting stress and mothers' adaptive functioning in educational, social support, and childbirth areas at follow-up. RESULTS: We found that parenting variables, but not personal adjustment variables, predicted later parenting stress. Results also showed that current adaptive functioning was significantly related to parenting stress. Specifically, educational status and social support predicted concurrent parenting stress, whereas number of childbirths did not. CONCLUSIONS: These findings extend the small literature on the link between parenting difficulties and parenting stress to adolescent mothers in foster care. Parenting challenges, particularly as reflected in unrealistic childrearing expectations, appear to be markers for later parenting stress. Considering the longitudinal relationships observed, early and periodic assessment of adolescent mothers' parenting knowledge, skills, and interactions is recommended. Also, given that this study found concurrent social support and educational status to covary with current parental stress, these variables, and others for which they may serve as proxy, are implicated for careful monitoring.

Adolescent↗
PubMed2005

Predictors of changes in sick leave in workers with asthma: a follow-up study.

OBJECTIVE: The aim of this prospective study was to investigate predictors of 1-year changes in sick leave in workers with asthma. METHODS: The initial cohort consisted of 111 workers with asthma. One-hundred and one participants completed the follow-up after 1 year. Self-reported sick leave over the past 12 months was reported at baseline and at follow-up. At the start of this study, all participants completed questionnaires on adaptation to functional limitations, psychosocial variables, working conditions, lung function characteristics, disease history characteristics, health complaints and functional limitations, and person characteristics ('potential predictors'). Three multivariate logistic regression models were calculated, with an increase in sick leave, a decrease in sick leave, and stable high sick leave as dependent (outcome) variables, and the potential predictors as independent (explanatory) variables. RESULTS: An increase in sick leave was predicted by a lower level of education and perceiving more functional limitations in activities of daily life. A decrease in sick leave was predicted by spending all energy at work less often and perceiving fewer health complaints in social activities (adaptation criteria 4 and 5). Stable high sick leave was predicted by less job satisfaction, perceiving more support from the employer and perceiving more health complaints in social activities (adaptation criterion 5). Lung function characteristics, or disease history characteristics were not predictive for changes in sick leave in any of the groups. CONCLUSION: We conclude that adaptation to functional limitations played a major role in changes in sick leave in workers with asthma. Lung function characteristics hardly played a role.

Adult↗
PubMed2004

Tumor size as a predictor of outcome in pediatric non-metastatic osteosarcoma of the extremity.

BACKGROUND: Better predictors of outcome would allow improved risk-adapted therapy for pediatric nonmetastatic osteosarcoma of the extremity. We investigated the predictive value of MR imaging-based measures of absolute and relative tumor size and volume at the time of diagnosis. We also assessed the relation of tumor size to age and histologic response. METHODS: We retrospectively abstracted demographic, treatment history, and outcome information of patients treated on a single institutional protocol. A single pediatric oncologic radiologist manually measured each primary lesion and the affected native bone in three dimensions on MR images obtained at the time of diagnosis. Eight parameters of tumor size were analyzed for their value in predicting overall survival (OS) and event-free survival (EFS). RESULTS: The median age of the 42 patients was 13.5 years (range: 5.9-18.7 years); 50% were female and 74% were Caucasian. Absolute tumor volume was an important predictor of OS (P < 0.05); absolute tumor depth (analyzed as a continuous variable) was a significant predictor of OS (P = 0.018) and EFS (P = 0.036). Relative measures of tumor size were not found to predict outcome. No relation was seen between tumor size and histologic response. CONCLUSIONS: Absolute tumor size at the time of diagnosis is significantly predictive of OS and EFS. If validated in a larger study, this indicator should be used in the design of risk-adapted treatment protocols for osteosarcoma.

Adolescent↗
PubMed2005

Adaptive evolution by optimizing expression levels in different environments.

Organisms adapt to environmental changes through the fixation of mutations that enhance reproductive success. A recent study by Dekel and Alon demonstrated that Escherichia coli adapts to different growth conditions by fine-tuning protein levels, as predicted by a simple cost-benefit model. A study by Fong et al. showed that independent evolutionary trajectories lead to similar adaptive endpoints. Initial mutations on the path to adaptation altered the mRNA levels of numerous genes. Subsequent optimization through compensatory mutations restored the expression of most genes to baseline levels, except for a small set that retained differential levels of expression. These studies clarify how adaptation could occur by the alteration of gene expression.

Bacteria↗
PubMed2003

An adaptive metabolic demand model for protein and amino acid requirements.

The shortcomings of the metabolic implications of the current protein requirements model are reviewed, and an alternative model, validated with [1-(13)C]leucine balance results in human adults, is presented and evaluated in the context of defining protein requirements. The model identifies metabolic demands for amino acids as comprising a small fixed component and a variable adaptive component that is relatively insensitive to acute food or protein intake, but which changes slowly with a sustained change in intake, enabling N equilibrium to be achieved. The model accounts for the apparent low efficiency of utilisation of animal proteins in N balance studies and enables more realistic efficiency values to be measured within an experimental framework that takes account of the adaptive metabolic demand. However, the complex relationship between the adaptive metabolic demand and habitual level and quality of protein intake prevents prediction of protein quality by amino acid scoring, which can markedly underestimate actual values. In contrast to the current model, for fully adapted individuals risk of deficiency (i.e. negative N balance after complete adaptation) will only start to increase when intakes fall below the range of the true minimum requirements, i.e. a value that is currently unknown, but likely to be between 0.40 and 0.50 g/kg per d at the lower end of the reported distribution of requirements. At intakes greater than this with additional metabolic demands varying directly with intake, deficiency is only likely as a short-term response to a change to a lower intake within the adaptive range. Thus, for adults satisfying energy needs on most mixed human diets, intakes will be within the adaptive range, and N equilibrium ceases to be a useful indicator of nutritional adequacy of protein. In the context of prescriptive dietary guidelines it may be expedient to retain current values until the benefits (and any risks) of protein intakes within the adaptive range can be quantified. However, from a diagnostic perspective, indicators other than N balance need to be identified, since maintenance of N balance can no longer be used as a surrogate of adequate protein-related health.

Adult↗
PubMed2026

No evidence of fine-scale local adaptation of winter moths to variable tree phenology.

Spatial variation in plant phenology can impose strong selective pressures on herbivorous insects whose fitness relies on synchrony with host plants, promoting local adaptation to host timing. Winter moths (Operophtera brumata) have been shown to synchronize egg hatching with host budburst, but whether this reflects local adaptation remains unclear. We used three complementary approaches to assess small-scale local adaptation of winter moths to oak phenology in Wytham Woods, UK, a 385-hectare woodland with repeatable variation in individual oak budburst phenology. We experimentally investigated whether host tree phenology predicts hatch timing using common gardens across multiple temperatures, evaluated fitness benefits of synchrony using translocations, and assessed population structure and gene-environment associations using whole-genome sequencing. We found no support for local adaptation to individual trees. Common garden experiments revealed systematic differences in hatch timing which were unrelated to host budburst, while translocations indicated no fitness consequences of asynchrony. Genetic analyses showed no detectable population structure or association with budburst timing. Local adaptation to host phenology therefore appears not to arise on individual trees but may instead occur at broader spatial scales. Understanding the scale of local adaptation is essential for predicting how insect-plant synchrony will respond to environmental change across heterogeneous landscapes.

Animals↗
PubMed1990

Family functioning and the social adaptation of hearing-impaired youths.

This study examined the associations between important aspects of family functioning and the adjustment of hearing-impaired youths. Participants were 75 hearing-impaired youths and their hearing parents. The dependent variables were mothers' and fathers' ratings of child behavior problems and social competence. Independent variables included parental symptomatology, parental ratings of family stress, and family members' perceptions of family cohesion and family adaptability. Demographic characteristics and the youth's degree of hearing loss and mode of communication were used as control variables. Results from multiple regression analyses showed that parental ratings of the youths' behavior problems were linked with parental symptomatology, and that maternal ratings of the youths' behavior problems were associated with low family adaptability. Parental ratings of the youths' social competence were predicted by family stress. Overall, key aspects of family functioning accounted for considerably more variance than did the control variables. The methodological and conceptual implications of the findings are discussed.

Adaptation, Psychological↗