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PubMed2005

Parallel evolution of chimeric fusion genes.

To understand how novel functions arise, we must identify common patterns and mechanisms shaping the evolution of new genes. Here, we take advantage of data from three Drosophila genes, jingwei, Adh-Finnegan, and Adh-Twain, to find evolutionary patterns and mechanisms governing the evolution of new genes. All three of these genes are independently derived from Adh, which enabled us to use the extensive literature on Adh in Drosophila to guide our analyses. We discovered a fundamental similarity in the temporal, spatial, and types of amino acid changes that occurred. All three genes underwent rapid adaptive amino acid evolution shortly after they were formed, followed by later quiescence and functional constraint. These genes also show striking parallels in which amino acids change in the Adh region. We showed that these early changes tend to occur at amino acid residues that seldom, if ever, evolve in Drosophila Adh. Changes at these slowly evolving sites are usually associated with loss of function or hypomorphic mutations in Drosophila melanogaster. Our data indicate that shifting away from ancestral functions may be a critical step early in the evolution of chimeric fusion genes. We suggest that the patterns we observed are both general and predictive.

Adaptation, Biological↗
PubMed1998

Cone b-wave implicit time as an early predictor of rubeosis in central retinal vein occlusion.

PURPOSE: To investigate the predictive value of the cone b-wave implicit time in the 30-Hz flicker electroretinogram for rubeosis in the acute phase of central retinal vein occlusion. METHODS: In a prospective study, 25 patients (25 eyes) with a central retinal vein occlusion of less than 14 days' duration were examined with electroretinography and followed up for a minimum of 18 months. RESULTS: The cone b-wave implicit time in the eyes that developed rubeosis (n = 11) was more than 37.1 milliseconds and in the eyes that did not develop rubeosis (n = 14), less than 37 milliseconds (P < .00001). CONCLUSION: The cone b-wave implicit time in the 30-Hz flicker electroretinogram is a good predictor of rubeosis at an early stage in eyes with central retinal vein occlusion.

Acute Disease↗
PubMed1990

Right upper lobectomy twenty years after left pneumonectomy. Preoperative evaluation and follow-up.

Quantitative perfusion lung scanning coupled with spirometry and balloon occlusion of the pulmonary artery supplying the lung to be resected have been used to predict the potential operability of patients being considered for pneumonectomy. These techniques were adapted for the lobar level prior to performing a right upper lobectomy in a 59-year-old man who had undergone a left pneumonectomy 20 years previously. This case demonstrates how physiologic reserve can be predicted in patients who require sequential pulmonary resection.

Carcinoma, Bronchogenic↗
PubMed1997

Empirical Bayes prediction of 305-day milk production.

A lactation curve described by an algebraic formula can be fitted by regression to the milk weights in the partial record of an individual lactation in progress; however, curves that are obtained in this manner do not provide useful predictions of milk production throughout the remainder of the lactation. This study examined the reasons for this failure and introduced a new empirical Bayes statistical method for fitting Wood's curve that was designed to provide good predictions of future production. The results of a comparison between predictions produced by the new method and predictions from Dairy Herd Improvement Association extension factors were quite favorable to the new method, which has advantages other than greater accuracy; the method does not require preparation of extension factor tables and can be readily adapted to individual herds. Comparisons revealed features of the Dairy Herd Improvement Association predictions that limit their usefulness for some herd management purposes.

Algorithms↗
PubMed2002

A dynamic model of hypothermia as an adaptive response by small birds to winter conditions.

We present a dynamic programming model which is used to investigate hypothermia as an adaptive response by small passerine birds in winter. The model predicts that there is a threshold function of reserves during the night, below which it is optimal to enter hypothermia, and above which it is optimal to rest. This threshold function decreases during the night, with a particularly sharp drop at the end of the night, representing the time and energy costs associated with returning to normal body temperature. The results of the model emphasise the trade-off between energy and predation, not just between foraging options, but also between foraging during the day and entering hypothermia at night. The value of being able to use hypothermia represents not just energy savings, but also reduced predation risk due to changes in the optimal foraging strategy. Conditions which give a high value of hypothermia are short photoperiod, variable food supply, low temperatures, poor and scarce food supplies.

Adaptation, Physiological↗
PubMed1999

Development of adaptive phonetic gestures in children: evidence from vowel devoicing in two different dialects of Japanese.

High vowels between voiceless consonants are often devoiced in many languages, as well as in many dialects of Japanese. This phenomenon can be hypothesized to be a consequence of the adaptive organization of the laryngeal gestures to various conditions, including dialectal requirements. If this theory is correct, it may be possible to predict developmental changes in vowel devoicing based on the developmental improvement in the dialect-specific organization of the laryngeal gestures. To test this expectation, the developmental properties of vowel devoicing were investigated for 72 children of 4 and 5 years of age, and 37 adults in two dialects of Japanese. One was the Osaka dialect, with a low devoicing rate, and the other the Tokyo dialect, with a high devoicing rate. In the Tokyo dialect, the devoicing rate of children significantly increased and reached an adultlike level by the age of 5 years, whereas it remained low irrespective of age in Osaka. The vowel devoicing of 5-year-old children exhibited the same characteristics as that of the adults of their respective dialect. These results suggest that children growing up with the Tokyo dialect acquire the articulatory gestures which do not inhibit vowel devoicing by the age of 5 years, whereas children growing up with the Osaka dialect acquire those which inhibit the devoicing of vowels by the same age. The results fit in well with the predictions of the gestural account of vowel devoicing. It is also suggested that learning dialect-specific adaptive strategies to coordinate voicing and devoicing gestures as required to attain an adultlike vowel devoicing pattern is a long process: By the age of 5 years children have completed enough of this process to become members of their dialectal community.

Adaptation, Psychological↗
PubMedDate not supplied

Child behavior problems and family functioning as predictors of adherence and glycemic control in economically disadvantaged children with type 1 diabetes: a prospective study.

OBJECTIVE: This prospective study examined how child behavior problems and family functioning predict adherence behavior and glucose regulation (glycemic control) in a sample of economically disadvantaged children. METHODS: Children with type 1 diabetes (N = 116; 58.6% African American) were assessed for externalizing and internalizing behavior problems and family adaptability and cohesion and followed for a mean of 3.8 years. Glycemic control (glycosylated hemoglobin [HbA1c]) was assessed at baseline and follow-up, and adherence was assessed at follow-up. RESULTS: Analyses controlled for baseline HbA1c and years to follow-up. Multivariate analyses indicated that better adherence was predicted by high family cohesion. Better glycemic control was predicted by high family cohesion, the absence of externalizing behavior problems, and the presence of internalizing behavior problems. In addition, tests of moderation indicated that better follow-up glycemic control occurred among girls from high cohesion families and younger children from low adaptability families. Although better adherence predicted better glycemic control, adherence did not mediate the relationships of behavior problems or family functioning with glycemic control. CONCLUSIONS: A child's behavior problems and family functioning may influence both adherence to the diabetes regimen and glycemic control several years later, suggesting the potential value of interventions that address child behavior and family functioning.

Adaptation, Psychological↗
PubMed2001

A neural network approach for predicting and modelling the dynamical behaviour of cardiac ventricular repolarisation.

Physiological signals are usually patient specific, and they are difficult to predict, especially for the cardiovascular system. New methods capable to be adapted to each case and to learn the singular behavior of heart functions should be developed to support physicians in their decision-making. One of the most widely studied relations is the QT-RR one, between the total duration of the ventricle activation and inactivation, and the heart rate. In the past, different studies were made to approach this relation in the steady state. In this paper, a new method for modeling and predicting the transient dynamic behaviour of QT interval in relation to changing RR intervals is presented using artificial neural networks.

Action Potentials↗
PubMed2001

Adaptive and maladaptive perfectionism in medical students: a longitudinal investigation.

OBJECTIVES: The personality of medical students may have an important impact on both their academic performance and emotional adjustment during medical school. There has been little systematic study of the impact of perfectionism on medical students. The present study sought to compare the perfectionism profile of medical students with that of a general arts student group and to examine the relationship among perfectionism, distress symptoms and academic expectations and satisfaction. DESIGN: Medical students (n=96) and arts students (n=289) completed a baseline assessment including two multidimensional perfectionism scales. The medical students also completed measures of distress symptoms, personality (neuroticism, conscientiousness) and questions about their perceptions of their academic performance. Of the medical students, 58 completed a second set of questionnaires 6 months later (time 2). SUBJECTS: First-, second- and third year medical students and first-year arts students. RESULTS: In comparison with arts students, the perfectionism profile of medical students showed higher personal standards, lower doubts about actions and lower maladaptive perfectionism scores. In the medical students adaptive perfectionism (achievement striving) was significantly correlated with baseline academic performance expectations and conscientiousness and was predictive of dissatisfaction with academic performance at time 2. Maladaptive perfectionism (excessive evaluative concerns) was significantly correlated with baseline distress symptoms and neuroticism and was predictive of symptoms of depression and hopelessness at time 2. CONCLUSIONS: Perfectionism in medical students differs systematically from perfectionism in general arts students. Distinguishing adaptive and maladaptive aspects of perfectionism is important in understanding the cross-sectional and longitudinal implications of perfectionism for medical students.

Adult↗
PubMed1999

Measuring post-traumatic stress: a psychometric evaluation of symptom--and coping questionnaires based on a Norwegian sample.

The purpose of this study was to evaluate the psychometric characteristics of the Norweigian versions of the Impact of Event Scale, the Post Traumatic Stress Scale-10 item version and General Coping Questionnaire-30 item version. A group of 40 male and 56 female medical students was tested one week and four months after having started dissection of cadavers for the first time. The results showed that all scales had good internal consistency and test-retest reliability. The student sample scored lower on the IES and PTSS-10 than comparable groups of traumatized subjects. A gender difference emerged, with female subjects scoring higher than male subjects. The factor analysis of the instruments indicated good construct validity for the symptom scales. The analysis of content validity related to DSM IV criteria indicated that the IES and PTSS-10 may have some limitations in their predictive validity of PTSD. Taken together, the three scales have shown good psychometric properties and could be used in future research and clinical work.

Adaptation, Psychological↗
PubMed2001

Modeling and remodeling in a developing artiodactyl calcaneus: a model for evaluating Frost's Mechanostat hypothesis and its corollaries.

The artiodactyl (mule deer) calcaneus was examined for structural and material features that represent regional differences in cortical bone modeling and remodeling activities. Cortical thickness, resorption and formation surfaces, mineral content (percent ash), and microstructure were quantified between and within skeletally immature and mature bones. These features were examined to see if they are consistent with predictions of Frost's Mechanostat paradigm of mechanically induced bone adaptation in a maturing "tension/compression" bone (Frost, 1990a,b, Anat Rec 226:403-413, 414-422). Consistent with Frost's hypothesis that surface modeling activities differ between the "compression" (cranial) and "tension" (caudal) cortices, the elliptical cross-section of the calcaneal diaphysis becomes more elongated in the direction of bending as a result of preferential (> 95%) increase in thickness of the compression cortex. Regional differences in mineral content and population densities of new remodeling events (NREs = resorption spaces plus newly forming secondary osteons) support Frost's hypothesis that intracortical remodeling activities differ between the opposing cortices: 1.) in immature and mature bones, the compression cortex had attained a level of mineralization averaging 8.9 and 6.8% greater (P < 0.001), respectively, than that of the tension cortex, and 2.) there are on average 350 to 400% greater population densities of NREs in the tension cortices of both age groups (P < 0.0003). No significant differences in cortical thickness, mineral content, porosity, or NREs were found between medial and lateral cortices of the skeletally mature bones, suggesting that no modeling or remodeling differences exist along a theoretical neutral axis. However, in mature bones these cortices differed considerably in secondary osteon cross-sectional area and population density. Consistent with Frost's hypothesis, remodeling in the compression cortex produced bone with microstructural organization that differs from the tension cortex. However, the increased remodeling activity of the tension cortex does not appear to be related to a postulated low-strain environment. Although most findings are consistent with predictions of Frost's Mechanostat paradigm, there are several notable inconsistencies. Additional studies are needed to elucidate the nature of the mechanisms that govern the modeling and remodeling activities that produce and maintain normal bone. It is proposed that the artiodactyl calcaneus will provide a useful experimental model for these studies.

Animals↗
PubMed2002

Interplay among the changes of muscle strength, cross-sectional area and maximal explosive power: theory and facts.

A model has recently been proposed to predict the changes of mechanical power (W) during a maximal explosive effort (such as a standing high jump off both feet) following an adaptation (e.g. training/de-training). The model is based on the assumption that, all other things being equal (ceteris paribus), the predicted changes in W depend on the measured changes of muscle force (F) or cross-sectional area (CSA) only. It follows that, if the measured changes in W are not equal to those predicted by the model, factors other than a change in F (or CSA) must be responsible for this difference. The model does not allow the determination of factors specifically involved in the adaptation process but it helps in discriminating whether an adaptation has taken place at a local level (when the observed changes in F would be attributed to factors other than the observed changes in CSA, e.g. co-contractions, fibre type modifications...), or at a central level (when the observed changes in W would be attributed to other factors than the observed changes in F, e.g. co-ordination of multiple joints and muscle groups...), or in both regions. In this paper the model has been applied to data reported in the literature on disuse (BR, bed rest), de-conditioning (SF, space flight), strength training (ST) and de-training (DT). The results of these calculations have confirmed previous observations on the determinants of the adaptation process and further suggest: (1) that training for one specific motor task (e.g. ST) could affect the performance of a second task (e.g. a maximal explosive jump) but that, as soon as the trained motor task is terminated (DT), this ability is re-gained; and (2) that neuromuscular impairment in disuse (BR) is closer to de-training than to the de-conditioning brought about by weightlessness (SF).

Anatomy, Cross-Sectional↗
PubMed1993

Parental risk and resistance factors among children with juvenile rheumatic disease: a four-year predictive study.

Examined the extent to which baseline functioning and parental risk and resistance factors predicted disease-related (functional disability and pain) and psychosocial functioning (social competence and behavior problems) 4 years later among 172 children with juvenile rheumatic disease. The study also examined the extent to which fathers' risk and resistance factors explained patients' adaptation, above and beyond maternal factors. Poorer baseline functioning was a strong risk factor that predicted poorer functioning 4 years later. In addition, parental risk and resistance factors at baseline predicted patients' adjustment after patients' age and baseline functioning were controlled. Mothers' and fathers' personal strain and depressed mood, and fathers' drinking problems, were associated with poorer patient adjustment; mothers' and fathers' social functioning appeared to aid patients' adjustment. Fathers' risk and resistance factors contributed independently from those of mother, to predict patients' outcome.

Adaptation, Psychological↗
PubMed2025

Integrative Genomic, Transcriptomic and Epigenomic Analysis Reveals cis-regulatory Contributions to High-altitude Adaptation in Tibetan Pigs.

The Qinghai-Tibet Plateau, characterized by its extreme environmental conditions, presents significant challenges to life, making it an ideal region for studying adaptation and evolution. Tibetan pigs, known for their high genetic diversity and exceptional adaptability to high altitudes, serve as excellent models for investigating high-altitude adaptation. While previous studies have extensively identified genetic determinants associated with high-altitude adaptation, the molecular mechanisms, particularly cis-regulatory patterns, remain poorly understood. Here, we conducted a selective sweep analysis using 484 genomes from Chinese and Western pig breeds across various altitudes, revealing 38.56 Mb of genomic regions under selection in Tibetan pigs. Enrichment analysis identified the lung as the primary functional tissue involved in high-altitude adaptation, supported by tissue-specific transcriptional and regulatory patterns observed between Tibetan and Meishan pigs (low altitude). By integrating genomic, RNA-seq, ATAC-seq, and H3K27ac HiChIP data, we constructed comprehensive enhancer-promoter regulatory maps of candidate genes and pinpointed promising genetic determinants associated with high-altitude adaptation, including SNPs in EPAS1, KLF13, SPRED1, and CFD. These loci were predicted to influence chromatin accessibility and the interactions of regulatory elements, with altered binding strength of relevant transcription factors. Further in vitro experiments confirmed that these loci function as allele-specific enhancers, modulating the expression of target genes. Our findings elucidate the regulatory basis of high-altitude adaptation in Tibetan pigs and provide valuable insights for exploring hypoxia-related diseases in livestock and humans.

Animals↗
PubMed2000

Domain architecture of a Caenorhabditis elegans AKAP suggests a novel AKAP function.

A-kinase anchoring proteins (AKAPs) are adapter proteins that are involved in directing cAMP-dependent protein kinase and some other signaling enzymes to certain intracellular locations. In this study, we investigate the domain architecture of an AKAP from Caenorhabditis elegans (AKAP(CE)). We show that AKAP(CE) shares two domains with the Smad anchor for receptor activation, a FYVE-finger and a transforming growth factor beta (TGFbeta) receptor binding domain, suggesting that AKAP(CE) may interact with a receptor belonging to the TGFbeta receptor family. This predicted novel AKAP function supports the recent view of AKAPs as adapter proteins that can be involved in various signaling pathways.

A Kinase Anchor Proteins↗
PubMed2005

CD10 and Bcl-2 expression combined with the International Prognostic Index can identify subgroups of patients with diffuse large-cell lymphoma with very good or very poor prognoses.

AIMS: Diffuse large B-cell lymphoma (DLBCL) is characterized by marked biological heterogeneity. The identification of reproducible parameters that can be combined with the International Prognostic Index (IPI) to better predict outcome could lead to the development of effective risk-adaptive strategies. METHODS AND RESULTS: Bcl-2 and CD10 expression was determined by immunohistochemistry. The impact of the positivity on survival was evaluated in combination with the IPI in 86 patients with a confirmed diagnosis of DLBCL. Patients were divided according to the IPI into low-risk (no to two factors) or high-risk (three to five factors) groups. Positivity rates were 25% for CD10 and 42% for Bcl-2. In a Cox analysis, the high-risk IPI group [hazard ratio (HR) 5.98, P < 0.0001) and Bcl-2 expression (HR 2.43, P = 0.02) were independent poor prognostic factors, and expression of CD10 (HR 0.41, P = 0.052) predicted a favourable outcome. Among patients in the low-risk IPI group, CD10 positivity was associated with an excellent 8-year overall survival (92% versus 45%, P = 0.06). In the high-risk IPI group, Bcl-2 positivity identified a subgroup with invariably fatal disease. CONCLUSIONS: The expression of CD10 in the low-risk IPI group, and the expression of Bcl-2 in the high-risk IPI group can identify two subgroups of patients who might benefit from new risk-adaptive treatment approaches.

Adult↗