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 1,513 records · Page 84Linked to original sources
PubMed2004

Adaptive allocation of stress-induced deformities on bird feathers.

Physiological stress during ontogeny is known to cause abnormalities in keratin structures of vertebrates, but little is known about if and how organisms have evolved mechanisms to reduce the negative effects of these abnormalities. Stress experienced during avian feather growth is known to lead to the formation of fault bars, and thereby to the weakening of feathers because of shortage and slimming of barbules. Here we propose and test a new hypothesis (the 'fault bar allocation hypothesis') according to which birds should have evolved adaptive strategies to counteract this evolutionary pressure. In particular, we predicted and tested the idea that in flying birds, natural selection should have selected for mechanisms to reduce fault bar load on feathers with high strength requirements during flight. Data on the growth of feathers of nestling white storks (Ciconia ciconia) revealed a consistent allocation of more, and more intense, fault bars in innermost than in outermost wing feathers as predicted by our hypothesis. Moreover, the same pattern emerged from feathers of adult storks. We discuss the generality of our results, and suggest avenues for further investigations in this area.

Adaptation, Physiological↗
PubMed1985

[Various mechanisms of the pathogenesis and etiotropic therapy of neurologic forms of epidemic parotitis].

Immunoenzymatic, clinical and follow up study of 3500 patients suffering from nervous forms of epidemic parotitis was performed. It is concluded that the adaptive humoral enzymes, ribonuclease and trypsin, the persistence of antigen to epidemic parotitis virus in CSF lymphocytes as well as the immunologic status of the patient at the disease onset play the leading role in the pathogenesis of its acute phase. It advisable to examine the factors enumerated in order to predict the clinical course of the disease. The treatment with adaptive enzymes was of great efficacy in 660 patients.

Child↗
PubMed2002

Dento-skeletal adaptation after bite-raising in growing rats with different masticatory muscle capacities.

The aim of this study was to analyse the effects of normal and hypofunctional masticatory muscles on dento-skeletal adaptation to posterior bite blocks in growing rats. Fifty-two young male rats were divided into two groups, fed a hard and soft diet, respectively, to develop different functional capacities in the masticatory muscles. Bone markers were inserted in the mandible on day 0. After two weeks, an appliance that raised the bite by 2 mm was inserted in half of each group. Lateral radiographs were taken on day 0, 14, 28, and 42 of the experiment. Images of the mandible were superimposed on the bone markers. Differences in cephalometric measurements were analysed by two-way ANOVA. The reduced muscle capacity resulted in an upward growth of the snout and a shorter mandibular ramus with less bone apposition on its lower border. Bite blocks induced a more upward growth of the snout and a shorter mandibular ramus, and inhibited the eruption of the upper molars and intruded the lower molars. The rats with weaker masticatory muscles had less inhibitory effect of the posterior bite blocks on upper molar eruption and showed different bone apposition in the ramus, especially during the first two weeks. In conclusion, masticatory muscle capacity seems to influence the effect of the posterior bite blocks on both tooth eruption and skeletal adaptation. The results suggest that the characteristics of the masticatory muscles should be taken into account when predicting the efficiency of a functional appliance.

Adaptation, Physiological↗
PubMed2004

Resources and resilience in the transition to adulthood: continuity and change.

Patterns of continuity and change in competence and resilience over the transition to adulthood were examined in relation to adversity and psychosocial resources, with a focus on adaptive resources that may be particularly important for this transition. Variable-focused and person-focused analyses drew on data from the Project Competence longitudinal study of a school cohort followed over 20 years from childhood through emerging adulthood (EA) into the young adulthood (YA) years with excellent retention (90%). Success in age-salient and emerging developmental tasks from EA to YA was examined in a sample of 173 of the original participants with complete data on adversity, competence, and key resources. Regressions and extreme-group analyses indicated striking continuity in competence and resilience, yet also predictable change. Success in developmental tasks in EA and YA was related to core resources originating in childhood (IQ, parenting quality, socioeconomic status) and also to a set of EA adaptive resources that included planfulness/future motivation, autonomy, adult support, and coping skills. EA adaptive resources had unique predictive significance for successful transitions to adulthood, both overall and for the small group of individuals whose pattern of adaptation changed dramatically from maladaptive to resilient over the transition. Results are discussed in relation to the possibility that the transition to adulthood is a window of opportunity for changing the life course.

Achievement↗
PubMed1986

Otoacoustic emissions, travelling waves and cochlear mechanisms.

The phenomenon of otoacoustic emissions is discussed in relation to the question--is the cochlear travelling wave actively enhanced? Distinctions are made between active loss reduction and true amplification, and between different types of emission source. The dynamic control exercised by the cochlea over the level of mechanical activity is analysed. An adaptive mechanism, capable of oscillatory transient behaviour is found both acoustically and psychophysically in response to strong low frequency stimulation. A feedback model is presented and used to predict aspects of emission behaviour.

Adaptation, Physiological↗
PubMed2004

New ICD-10 version of the Charlson comorbidity index predicted in-hospital mortality.

BACKGROUND AND OBJECTIVE: The ICD-9-CM adaptation of the Charlson comorbidity score has been a valuable resource for health services researchers. With the transition into ICD-10 coding worldwide, an ICD-10 version of the Deyo adaptation was developed and validated using population-based hospital data from Victoria, Australia. METHODS: The algorithm was translated from ICD-9-CM into ICD-10-AM (Australian modification) in a multistep process. After a mapping algorithm was used to develop an initial translation, these codes were manually examined by the coding experts and a general physician for face validity. Because the ICD-10 system is country specific, our goal was to keep many of the translated code at the three-digit level for generalizability of the new index. RESULTS: There appears to be little difference in the distribution of the Charlson Index score between the two versions. A strong association between increasing index scores and mortality exists: the area under the ROC curve is 0.865 for the last year using the ICD-9-CM version and remains high, at 0.855, for the ICD-10 version. CONCLUSION: This work represents the first rigorous adaptation of the Charlson comorbidity index for use with ICD-10 data. In comparison with a well-established ICD-9-CM coding algorithm, it yields closely similar prevalence and prognosis information by comorbidity category.

Algorithms↗
PubMed1992

Differences between patient and physician perceptions of predicted compliance.

One approach to improving patient compliance is for physicians to adapt their behaviour to fit patients' psychological characteristics. Previous university-based research has suggested that physician adaptation to patients' locus of control interferes with patient-physician congruence on expected compliance, but not with congruence on satisfaction with their relationship. This study was conducted in a community practice to clarify the relationship between the physician's adaptation to locus of control and likelihood of and commitment to compliance, and satisfaction with the doctor-patient match. One physician saw 148 patients with a variety of illnesses after they had completed the Health Locus of Control (HLC) questionnaire. The physician altered how he spoke with a patient based on whether the patient scored internally or externally on the HLC. After the encounter, both patient and physician rated the patient's likelihood of and commitment to complying with each of the three recommendations. The physician and each patient also rated their satisfaction with the match between them. Patients' ratings of commitment, likelihood, and satisfaction were significantly higher than those of the physician. Unlike earlier results, there were strong correlations between the patients' and physician's estimates of compliance (commitment and likelihood). Just as with the previous study, there was no correlation between the levels of physician and patient satisfaction with their match. This study indicates that physician adaptation to patients' locus of control does not interfere with compliance outcomes of doctor-patient encounters. Whether such adaptation will improve compliance outcomes is yet to be determined.

Adult↗
PubMed2004

Everyday activity predicts bone geometry in children: the iowa bone development study.

PURPOSE: Bone adapts to changing mechanical loads by altering the structure appropriately. These adaptations should be evident in the bone cross-sectional area (CSA) and section modulus (Z), indices of axial and bending strength, respectively. In this cross-sectional study, we investigated associations between physical activity, CSA, and Z in 467 young children (mean age 5.2 yr). We also examined whether lean tissue mass, which is predominantly muscle, mediates the relationship between physical activity and bone structural measures. METHODS: Physical activity was assessed using accelerometry and questionnaire. Proximal femur measures of the neck, intertrochanteric, and shaft CSA (cm) and Z (cm) were derived from dual-energy x-ray absorptiometry (DXA) scans using the Hip Structure Analysis program. Total body lean mass (kg) was also measured using DXA. RESULTS: Boys were more physically active than girls. Boys also had greater CSA, Z, and lean mass than girls. At each region, time spent in vigorous activity was positively and consistently associated with CSA and Z in boys and girls (r = 0.19 to 0.32). After adjustment for age, body mass, and height, vigorous activity explained, on average, 6.9% of the variability in CSA and Z. With additional adjustment for lean mass, vigorous activity explained 3.7% of the remaining variability in CSA and Z. CONCLUSION: This study demonstrates that everyday amounts of physical activity in healthy, normal children are associated with bone geometry and that differences in lean mass explain some, but not all, of this association. This suggests that, even in young, nonathletic children, bone may adapt to physical activity by structurally remodeling.

Anthropometry↗
PubMed1995

[Validation trial of a neonatal prophylactic antibiotic protocol in the delivery room].

Maternofetal infection occurs in 1 to 10 of every 1,000 newborns. Prognosis is poor and an extremely rapid the clinical course is sometimes observed. The situation suggests that widespread use of antibiotics and more than 90% of the newborns receiving antibiotics are not infected. A prospective study based on simple, recognized criteria predictive of maternal-fetal infection was conducted in 3,392 deliveries to evaluate the effect of an antibiotic prophylaxy protocol. Specificity, sensitivity, positive and negative predictive value were evaluated for each of the eleven criteria retained with the goal of increasing sensitivity and decrease the use of unnecessary antibiotics. Among the 3,392 infants delivered from January 1989 to December 1990, 286 (8.4%) newborns entered the study and were given mezlocillin (150 mg/kg/12 h). This treatment was stopped at 48 hours of life if the infant was not infected. RESULTS. Infection was confirmed in 48 of 3,392 infants (1.4%). All were in the risk group: 48/286 (16.7%). The germs the most often found were group B Streptococcus (n = 16), Escherichia coli (n = 8) and Listeria monocytogenes (n = 3). Nine criteria were well correlated with maternal-fetal infection. The two most important criteria were maternal pyrexia above 39 degrees C and Apgar score below 7 to 5 min (poor neonatal adaptation), with a 99% and 90% and a positive predictive value of 80% and 37% respectively. Inversely, Two criteria were poorly correlated with maternal-fetal infection: labour duration above 12 hours and instrumental extraction (positive predictive value from 10% to 17%).(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Infections↗
PubMed2004

Quantification of the cytoplasmic spaces of living cells with EGFP reveals arrestin-EGFP to be in disequilibrium in dark adapted rod photoreceptors.

The hypothesis is tested that enhanced green fluorescent protein (EGFP) can be used to quantify the aqueous spaces of living cells, using as a model transgenic Xenopus rods. Consistent with the hypothesis, regions of rods having structures that exclude EGFP, such as the mitochondrial-rich ellipsoid and the outer segments, have highly reduced EGFP fluorescence. Over a 300-fold range of expression the average EGFP concentration in the outer segment was approximately half that in the most intensely fluorescent regions of the inner segment, in quantitative agreement with prior X-ray diffraction estimates of outer segment cytoplasmic volume. In contrast, the fluorescence of soluble arrestin-EGFP fusion protein in the dark adapted rod outer segment was approximately threefold lower than predicted by the EGFP distribution, establishing that the fusion protein is not equilibrated with the cytoplasm. Arrestin-EGFP mass was conserved during a large-scale, light-driven redistribution in which approximately 40% of the protein in the inner segment moved to the outer segment in less than 30 minutes.

Animals↗
PubMed2002

Predictive microbiology: providing a knowledge-based framework for change management.

This contribution considers predictive microbiology in the context of the Food Micro 2002 theme, "Microbial adaptation to changing environments". To provide a reference point, the state of food microbiology knowledge in the mid-1970s is selected and from that time, the impact of social and demographic changes on microbial food safety is traced. A short chronology of the history of predictive microbiology provides context to discuss its relation to and interactions with hazard analysis critical control point (HACCP) and risk assessment. The need to take account of the implications of microbial adaptability and variable population responses is couched in terms of the dichotomy between classical versus quantal microbiology introduced by Bridson and Gould [Lett. Appl. Microbiol. 30 (2000) 95]. The role of population response patterns and models as guides to underlying physiological processes draws attention to the value of predictive models in development of novel methods of food preservation. It also draws attention to the paradox facing today's food industry that is required to balance the "clean, green" aspirations of consumers with the risk, to safety or shelf life, of removing traditional barriers to microbial development. This part of the discussion is dominated by consideration of models and responses that lead to stasis and inactivation of microbial populations. This highlights the consequence of change on predictive modelling where the need is now to develop interface and non-thermal death models to deal with pathogens that have low infective doses for general and/or susceptible populations in the context of minimal preservation treatments. The challenge is to demonstrate the validity of such models and to develop applications of benefit to the food industry and consumers as was achieved with growth models to predict shelf life and the hygienic equivalence of food processing operations.

Bacteria↗
PubMed2006

Crystal structures of a poxviral glutaredoxin in the oxidized and reduced states show redox-correlated structural changes.

Glutaredoxins act as reducing agents for the large subunit of ribonucleotide reductase (R1) in many prokaryotes and eukaryotes, including humans. The same relationship has been proposed for the glutaredoxin and R1 proteins expressed by all orthopoxviruses, including vaccinia, variola, and ectromelia virus. Interestingly, the orthopoxviral proteins share 45% and 78% sequence identity with human glutaredoxin-1 (Grx-1) and R1, respectively. To study structure-function relationships of the vertebrate Grx-1 family, and reveal potential viral adaptations, we have determined crystal structures of the ectromelia virus glutaredoxin, EVM053, in the oxidized and reduced states. The structures show a large redox-induced conformational rearrangement of Tyr21 and Thr22 near the active site. We predict that the movement of Tyr21 is a viral-specific adaptation that increases the redox potential by stabilizing the reduced state. The conformational switch of Thr22 appears to be shared by vertebrate Grx-1 and may affect the strictly conserved Lys20. A crystal packing-induced structural change in residues 68-70 affects the GSH-binding loop, and our structures reveal a potential interaction network that connects the GSH-binding loop and the active site. EVM053 also exhibits a novel cis-proline (Pro53) in a loop that has been shown to contribute to R1-binding in Escherichia coli Grx-1. The cis-peptide bond of Pro53 may be required to promote electrostatic interactions between Lys52 and the C-terminal carboxylate of R1. Finally, dimethylarsenite was covalently attached to Cys23 in one reduced EVM053 structure and our preliminary data show that EVM053 has dimethylarsenate reductase activity.

Animals↗
PubMed1988

Cardiovascular function and arterial blood gases during isolated ultrafiltration in healthy man.

In order to recognize possible cardiovascular signs of underhydration during isolated ultrafiltration (IUF), we have studied the physiological hemodynamic adaptation to IUF in healthy man both above and below normohydration. In 7 subjects IUF was performed with the subjects in a normohydrated state at the start of IUF. In 8 subjects the IUF was preceded by a 1-hour infusion of Ringer solution equal to 3% of body weight. By invasive techniques, cardiac index (thermodilution), stroke index, heart rate, brachial and pulmonary arterial blood pressures, systemic vascular resistance index, central blood temperature, PaO2 and PaCO2 were measured. Calf vascular resistance was assessed by venous occlusion plethysmography. A recirculation period of 30 min was followed by IUF in both study groups. During IUF with overhydration and normohydration at the start of IUF, cardiac output fell because of a decline in stroke volume and an unchanged heart rate. Blood pressure remained constant because of systemic vascular constriction. PaO2 and PaCO2 remained unchanged. IUF in healthy man is mainly characterized by vascular constriction and an unchanged heart rate. Thus, the cardiovascular adaptation to ultrafiltration was the same whether or not ultrafiltration was performed at overhydration or normohydration at the start of ultrafiltration. Therefore, it is unlikely that monitoring of heart rate or noninvasive recording of blood pressure can predict whether a subject is becoming underhydrated during isolated ultrafiltration. The adaptation to IUF is similar to that observed during the treatment of uremic patients without complications.

Blood Gas Analysis↗
PubMed2005

Up-regulation of PINCH in the stroma of oral squamous cell carcinoma predicts nodal metastasis.

Particularly interesting new cysteine-histidine rich protein (PINCH), an adapter protein involved in integrin and growth factor signalling, is up-regulated in the stroma of colorectal, breast, prostate, lung and skin cancer. Strong stromal immunostaining for PINCH is an independent prognostic indicator for reduced survival in colorectal cancer, suggesting that PINCH is involved in the signalling that promotes tumour progression. Since no study on PINCH has been carried out in oral squamous cell carcinoma (OSCC), this study aimed to determine PINCH expression in OSCC and its clinicopathological significance. PINCH protein expression was examined by immunohistochemistry in 20 normal oral mucosa and in 57 OSCC specimens. The frequency of strong PINCH immunostaining was higher in tumour-associated stroma of OSCC (37%) as compared to normal oral mucosa (10%) (p=0.02). Strong PINCH stromal immunostaining predicted nodal metastasis: 19/26 (73%) OSCC cases with nodal metastasis had strong PINCH immunostaining compared to 9/31 (29%) cases without nodal metastasis (p=0.02). The PINCH expression in OSCC was more intense in stroma at the invasive edge than in intratumoural stroma. In conclusion, the up-regulation of PINCH protein in stroma may be involved in promoting invasion and metastasis in OSCC.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Intraductal papillary-mucinous tumors of the pancreas: predictive criteria of malignancy according to pathological examination of 53 cases.

BACKGROUND: One of the main problems in the management and treatment of intraductal papillary-mucinous tumors is the lack of a reliable predictive factor for malignancy. HYPOTHESIS: Surgical treatment could be adapted to macroscopic criteria (presence of mural nodules and diameter of the pancreatic duct and of the lesion) or to tumor location (main duct, branch duct, or combined lesions) associated with benign or malignant forms. DESIGN: Retrospective study. SETTING: Two university and tertiary referral centers. PATIENTS: Fifty-three consecutive patients who underwent pancreatic resection for intraductal papillary-mucinous tumors between January 1, 1985, and December 31, 2000. RESULTS: Macroscopic analyses of tumors showed 6 main duct lesions, 12 branch duct lesions, and 35 combined lesions. A carcinoma was present in 33 cases (62%): 22 (41%) were invasive and 11 (21%) were noninvasive; 9 (17%) were borderline tumors and 11 (21%) were benign. Carcinoma and invasive carcinoma forms were less frequent in branch duct lesions (P<.001 and P =.009, respectively). Mural nodules were more frequent in carcinomas (P =.006) and invasive carcinomas (P<.001), with a positive predictive value of malignancy of 81%. The diameter of lesions (branch duct lesion > or =30 mm) or main duct (main pancreatic duct > or =15 mm in combined or main pancreatic duct lesions) did not correlate with malignancy. CONCLUSIONS: No carcinoma occurred in branch duct types smaller than 30 mm without mural nodules. Limited resection may be appropriate only in this type of tumor.

Adenocarcinoma, Mucinous↗