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PubMedDate not supplied

Salient and emerging developmental tasks in the transition to adulthood.

Drawing on data from a normative sample of 205 children tracked into adulthood, this study examined the predictive links from 3 salient (friendship, academic, conduct) and 2 emerging (work, romantic) developmental tasks during the transition years around age 20 to adult adaptation 10 years later. Results (a) confirm the utility of salient developmental tasks for predicting adult success, (b) suggest that emerging domains have limited long-term predictive significance, and (c) more generally support a view that developmental tasks follow a course through life of waxing and waning salience and organization that has implications for future adaptation.

Adaptation, Psychological↗
PubMed2004

The alternative sigma factor sigmaB of Bacillus cereus: response to stress and role in heat adaptation.

A gene cluster encoding the alternative sigma factor sigma(B), three predicted regulators of sigma(B) (RsbV, RsbW, and RsbY), and one protein whose function is not known (Orf4) was identified in the genome sequence of the food pathogen Bacillus cereus ATCC 14579. Western blotting with polyclonal antibodies raised against sigma(B) revealed that there was 20.1-fold activation of sigma(B) after a heat shock from 30 to 42 degrees C. Osmotic upshock and ethanol exposure also upregulated sigma(B), albeit less than a heat shock. When the intracellular ATP concentration was decreased by exposure to carbonyl cyanide m-chlorophenylhydrazone (CCCP), only limited increases in sigma(B) levels were observed, revealing that stress due to ATP depletion is not an important factor in sigma(B) activation in B. cereus. Analysis of transcription of the sigB operon by Northern blotting and primer extension revealed the presence of a sigma(B)-dependent promoter upstream of the first open reading frame (rsbV) of the sigB operon, indicating that transcription of sigB is autoregulated. A second sigma(B)-dependent promoter was identified upstream of the last open reading frame (orf4) of the sigB operon. Production of virulence factors and the nonhemolytic enterotoxin Nhe in a sigB null mutant was the same as in the parent strain. However, sigma(B) was found to play a role in the protective heat shock response of B. cereus. The sigB null mutant was less protected against the lethal temperature of 50 degrees C by a preadaptation to 42 degrees C than the parent strain was, resulting in a more-than-100-fold-reduced survival of the mutant after 40 min at 50 degrees C.

Adaptation, Physiological↗
PubMedDate not supplied

Brain reaggregate cultures in neurotoxicological investigations: adaptational and neuroregenerative processes following lesions.

In vitro neural systems can be predictive for CNS neurotoxicity, except where xenobiotics primarily affect the blood-brain barrier. The wide range of systems now used in neurobiological studies is available for mechanistic neurotoxicological investigations although the choice of system is generally arbitrary. A more rational approach may now be justified. There are many culture systems available including neural cell lines, organotypic explant or reaggregation cultures, and primary monolayer cultures of individual neural cell types: neurons, astrocytes, and oligodendrocytes. Of these models much success has recently been achieved using the organotypic explant culture type. Similarly in our laboratories, using rat whole-brain reaggregate cultures, we have demonstrated good in vitro/in vivo correlations for the cholinergic neurotoxicant ethylcholine mustard aziridinium (ECMA) where specific cholinergic lesions are produced using low concentrations of ECMA (12.5 microM). Higher concentrations (25-50 microM) were more cytotoxic, as shown, for example, by nonspecific effects on cerebellar glutamatergic granule neurons. Treatment of reaggregates lesioned with the cholinotoxin with a neurotrophic factor, nerve growth factor (NGF), did not reverse the lesion but treatment of control cells with NGF (50 ng/ml) elevated both choline acetyltransferase (ChAT) activity and muscarinic receptor binding. The "lesioned" reaggregate culture system may thus be of future value in evaluating potential therapeutic agents that could reverse such lesions in the CNS. By supplementing the information gained in the reaggregate system with tests using primary monolayer cultures of neurons or astrocytes we can propose a stepwise screening system for potential neurotoxicants in vitro. In its simplest form this is (1) screen initially using tumor-derived neural cell line, (2) test selected compounds in whole-brain reaggregates, and (3) supplement information with primary monolayer cultures of individual neural cell types.

Adaptation, Physiological↗
PubMed1992

Technical note: utilization of sainfoin by grazing steers and a method for predicting daily gain from small-plot grazing data.

Sainfoin (Onobrychis viciaefolia Scop.) is adapted to the calcareous soils of the southern Great Plains and can provide early season forage that does not induce bloating; however, little is known about performance by ruminants grazing sainfoin. Our objective was to determine the effect of plant growth stage and grazing pressures on potential animal production from sainfoin as predicted from energy intake as a multiple of maintenance. Nitrogen-fertilized (100 kg of N/ha) Renumex sainfoin was grown under irrigation on a Pullman clay loam (fine, mixed, thermic Torretic Paleustoll) near Lubbock, TX. Light (L), medium (M), and heavy (H) grazing pressures were applied with steers grazing sainfoin that was at the bud (B), flower (F), and seed shatter (S) stages of growth. The L, M, and H pressures were grazed to remove 50, 75, and 90% of the standing plant height. Across growth stages, L, M, and H grazing pressures averaged 52, 69, and 87% removal of pregrazed herbage mass. Dry matter intake as a percentage of BW of steers averaged 3.9, 2.8, and 1.7 for L, M, and H grazing pressures. Across growth stages, predicted live weight gain for L, M, and H grazing pressures averaged .86, .67, and .03 kg/d. Our findings indicate that the multiple of maintenance method may be useful for evaluating treatments from small-plot grazing experiments.

Animals↗
PubMed2002

[Stair climbing test in prediction of postoperative complications after lung cancer surgery].

Preoperative physical state of a patient is very important for adaptation of the patient after lung resections. Purpose of this work is to evaluate an information factor of a stair-climbing test while predicting of postoperative complications after lung cancer surgery. Fifty two patients were examined, who passed lung surgery of different volume. The patients are distributed to two groups: I(st) group included the patients able to climb 1-44 footsteps (n=22/42.3%) and the II(nd) group included the patients able to climb more than 44 footsteps at a moderate speed without stopping for rest (n=30/57.7%). One flight of stairs made up to 22 footsteps with 15 cm of height each. Postoperative myocardial ischemia, disorders of heart rhythm, pneumonias, atelectasis, prolonged artificial ventilation of lungs, sanative bronchoscopy, duration of treatment, and cases of death were registered. It was established that postoperative cardiac and lung complications occurred in 17 patients (32.7%), two patients died (3.8%). Rate of complications between the patients of the I(st) and II(nd) group was 82.4 ir 17.6 percent. Postoperative course was normal for those patients (n=11) who were able to climb five or more flights of stairs. It was noticed that duration of postoperative period has an inverse proportion to a number of the climbed up footsteps. The stair-climbing test is a simple, safe, cheap and informative enough for prediction of postoperative cardiopulmonary complications after lung cancer surgery.

Aged↗
PubMed2005

Prediction of gastric cancer lymph node status by sentinel lymph node biopsy and the Maruyama computer model.

AIMS: The extent of lymph node dissection in gastric cancer remains controversial. The Maruyama computer model and the sentinel lymph node biopsy (SLNB) are compared for their value to predict the nodal status and lead to stage-adapted surgery. METHODS: Thirty four patients with stage I-IV gastric cancer underwent both staging procedures. For SLNB, 15 patients underwent endoscopic, peri-tumoural injection of (99m)Tc-colloid, and 19 patients were injected of Patent blue V. All 'hot' or blue sentinel lymph nodes (SLNs) were separately excised and histopathologically assessed. If the SLN was negative after routine staining by H&E, it was processed completely and reanalysed after immunohistochemistry. RESULTS: At least, one SLN was detected by means of SLNB in 33/34 of the patients. The sensitivity to identify a positive nodal status was 22/33 and the specificity/positive predictive value was 10/10 and 22/22. Additional micrometastases or isolated tumour cells in the SLN led to 'upstaging' of 5/15, initially classified as nodal negative by H&E-staining. Using the Maruyama computer model, a sensitivity of 22/23 for the correct prediction of the lymph node involvement was associated with a specificity of 2/10 and a positive predictive value of 22/30. CONCLUSIONS: The clinical impact of the Maruyama computer model is limited due to low specificity and a low positive predictive value, rendering the method less useful as an indicator for individualised surgery.

Diagnosis, Computer-Assisted↗
PubMed2006

Tuning a bacterial chemoreceptor with protein-membrane interactions.

Chemoreceptors in Escherichia coli are homodimeric transmembrane proteins that convert environmental stimuli into intracellular signals controlling flagellar motion. Chemoeffectors bind to the extracellular (periplasmic) domain of the receptors, whereas their cytoplasmic domain mediates signaling and adaptation. The second transmembrane helix (TM2) connects these two domains. TM2 contains an aliphatic core flanked by amphipathic aromatic residues that have specific affinity for polar-hydrophobic membrane interfaces. We previously showed that Trp-209, near the cytoplasmic end of TM2, helps maintain the normal baseline-signaling state of the aspartate chemoreceptor (Tar) and that Tyr-210 plays an auxiliary role in this control. We have now repositioned the Trp-209/Tyr-210 pair in single-residue increments about the cytoplasmic polar-hydrophobic interface. Changes from WY-2 to WY+1 modulate the baseline-signaling state of the receptor in predictable and incremental steps that can be compensated by adaptive methylation/demethylation. Greater displacements, as in WY-3, WY+2, and WY+3, bias the receptor to the off kinase-inhibiting state or the on kinase-stimulating state, respectively, to a degree that cannot be fully compensated by the adaptation system. Aromatic residues analogous to Trp-209/Tyr-210 are present in other chemoreceptors and many transmembrane sensor kinases, where they may serve a similar function.

Amino Acid Sequence↗
PubMed1991

Individual differences in children's response to pain: role of temperament and parental characteristics.

Sixty-five families were enlisted in a study exploring factors associated with distress behavior in 5-year-old children receiving diphtheria-tetanus-pertussis immunizations. At a home visit 1 month before the immunization, the following measures were obtained: (1) the Behavioral Style Questionnaire, a measure of temperament: (2) parental self-reports of medically related attributes (eg. "good patient"); (3) parental attitudes toward pain in children and responsiveness to their child's pain; and (4) parental prediction of distress at upcoming immunization. The child's distress behavior during the immunization was evaluated using a modification of the Procedure Rating Scale-Revised and, after the procedure, the child's assessment of his or her pain was elicited using the Oucher. Children's mean Procedure Rating Scale-Revised score was 2.57 of a possible 11. Thirty-one (48%) had low (less than or equal to 1) and 7 (11%) had high distress scores (greater than or equal to 2 SD above the mean). Factors positively correlated with distressed behavior included more "difficult child" cluster characteristics, the individual temperamental dimension of adaptability, but few parental attitudes and attributes. Parent's predictions of distress were the strongest correlates. These findings document the variation that children demonstrate in response to pain and offer some insight into associated innate and environmental factors. These results imply that treatment strategies derived from parental knowledge and tailored to individual characteristics of the child may be most effective in alleviating pain-related distress in medical settings.

Attitude↗
PubMed2003

Childhood personality foreshadows adult personality and life outcomes two decades later.

In a normative sample of 205 children ages 8-12, tracked into adulthood, we examined the predictive links between four childhood personality traits--Mastery Motivation, Academic Conscientiousness, Surgency, and Agreeableness--and adult personality and adaptation 20 years later. Personality demonstrated modest to moderate continuity over those two decades and showed significant predictive validity for success in adult life, including academic attainment, work competence, rule-abiding versus antisocial conduct, and romantic and friend relationships. Results indicated that personality shows coherent patterns over time in terms of both stability and linkages to adaptive behavior. Explicating the processes underlying such patterns is the next frontier for a truly developmental science of personality.

Adult↗
PubMed2003

Cognitive adaptation: a comparison of cancer patients and healthy references.

OBJECTIVES: Taylor's theory of cognitive adaptation proposes that adjustment depends on the ability to sustain and modify illusions (i.e. unrealistic optimism, exaggerated perceptions of control, and self-aggrandizement) that buffer against threats but also against possible future setbacks. Because the question of whether cancer patients show these illusions has received little attention, the present study compared patients' perceptions of optimism, control, and self-esteem at different stages of the cancer process with that of healthy references. The effects of these perceptions on psychological distress were also assessed. DESIGN: The present study has a longitudinal design. Including a group of healthy references enabled us to draw more firm conclusions about the effect of cancer upon cognitive perceptions. METHODS: The participants were 67 cancer patients and 50 healthy references. Patients filled out questionnaires prior to their first radiotherapy (T1), at 2 weeks (T2), and at 3 months (T3) after completing radiotherapy. Healthy references were assessed at similar intervals. RESULTS: T tests revealed that patients experienced significantly higher levels of optimism and self-esteem than the healthy reference group. Concerning control, no group differences were found. Importantly, regression analyses showed that lower levels of optimism and control at T1 were predictive of feelings of anxiety at T3. Lower perceived control also predicted depressive symptoms. CONCLUSION: Results support the theory of cognitive adaptation in that patients are indeed able to respond to cancer with high levels of optimism and self-esteem and that lower levels of optimism and control are predictive of psychological distress.

Adaptation, Psychological↗
PubMed1980

Oscillatory potential and nyctometry in insulin-dependent diabetics.

The study draws a comparison between the oscillatory potential of the electroretinogram and the initial dark-adaptation measured by nyctometry, with the aim of assessing the predictive value of nyctometry in juvenile diabetics. The study included 61 insulin-dependent juvenile diabetics, aged 18-49 years, with a disease duration of more than five years. A statistically highly significant correlation could be demonstrated between alterations in the oscillatory potential and in the initial dark-adaptation. The results justify the assumption that nyctometry can be used as an easily handled clinical tool in selecting those at risk of developing proliferative retinopathy in their subsequent 6-8 years.

Adolescent↗
PubMed2003

A complex-valued nonlinear neural adaptive filter with a gradient adaptive amplitude of the activation function.

A complex-valued nonlinear gradient descent (CNGD) learning algorithm for a simple finite impulse response (FIR) nonlinear neural adaptive filter with an adaptive amplitude of the complex activation function is proposed. This way the amplitude of the complex-valued analytic nonlinear activation function of a neuron in the learning algorithm is made gradient adaptive to give the complex-valued adaptive amplitude nonlinear gradient descent (CAANGD). Such an algorithm is beneficial when dealing with signals that have rich dynamical behavior. Simulations on the prediction of complex-valued coloured and nonlinear input signals show the gradient adaptive amplitude, CAANGD, outperforming the standard CNGD algorithm.

Algorithms↗
PubMed1991

Life stressors, personal and social resources, and depression: a 4-year structural model.

By extending earlier stress-resistance research with a 1-year time lag, findings with 254 adults show that adaptive personality characteristics and positive family support operate prospectively over 4 years in predicting reduced depression, even when prior depression is controlled. By strengthening knowledge about the determinants and mediational role of coping, the results demonstrate in a 2-group LISREL analysis that the pattern of predictive relations differs under high and low stressors. Under high stressors, personal and social resources relate to future psychological health indirectly, through more adaptive coping strategies. Under low stressors, these resources relate directly to psychological health. The results support the idea that such resources play a causal role in maintaining psychological health, and they suggest the potential for a general, adaptively oriented framework applicable to adjustment under both high and low stressors.

Adaptation, Psychological↗
PubMed2001

Horizontal vestibuloocular reflex evoked by high-acceleration rotations in the squirrel monkey. IV. Responses after spectacle-induced adaptation.

The horizontal angular vestibuloocular reflex (VOR) evoked by sinusoidal rotations from 0.5 to 15 Hz and acceleration steps up to 3,000 degrees /s(2) to 150 degrees /s was studied in six squirrel monkeys following adaptation with x2.2 magnifying and x0.45 minimizing spectacles. For sinusoidal rotations with peak velocities of 20 degrees /s, there were significant changes in gain at all frequencies; however, the greatest gain changes occurred at the lower frequencies. The frequency- and velocity-dependent gain enhancement seen in normal monkeys was accentuated following adaptation to magnifying spectacles and diminished with adaptation to minimizing spectacles. A differential increase in gain for the steps of acceleration was noted after adaptation to the magnifying spectacles. The gain during the acceleration portion, G(A), of a step of acceleration (3,000 degrees /s(2) to 150 degrees /s) increased from preadaptation values of 1.05 +/- 0.08 to 1.96 +/- 0.16, while the gain during the velocity plateau, G(V), only increased from 0.93 +/- 0.04 to 1.36 +/- 0.08. Polynomial fits to the trajectory of the response during the acceleration step revealed a greater increase in the cubic than the linear term following adaptation with the magnifying lenses. Following adaptation to the minimizing lenses, the value of G(A) decreased to 0.61 +/- 0.08, and the value of G(V) decreased to 0.59 +/- 0.09 for the 3,000 degrees /s(2) steps of acceleration. Polynomial fits to the trajectory of the response during the acceleration step revealed that there was a significantly greater reduction in the cubic term than in the linear term following adaptation with the minimizing lenses. These findings indicate that there is greater modification of the nonlinear as compared with the linear component of the VOR with spectacle-induced adaptation. In addition, the latency to the onset of the adapted response varied with the dynamics of the stimulus. The findings were modeled with a bilateral model of the VOR containing linear and nonlinear pathways that describe the normal behavior and adaptive processes. Adaptation for the linear pathway is described by a transfer function that shows the dependence of adaptation on the frequency of the head movement. The adaptive process for the nonlinear pathway is a gain enhancement element that provides for the accentuated gain with rising head velocity and the increased cubic component of the responses to steps of acceleration. While this model is substantially different from earlier models of VOR adaptation, it accounts for the data in the present experiments and also predicts the findings observed in the earlier studies.

Acceleration↗
PubMed1984

[Phenomenon of pyrophosphate accumulation in the prognosis of different forms of ischemic heart disease].

The results of pyrophosphate 99mTc scintigraphy of the myocardium during exercise were compared with the parameters of the tolerance and adaptation to the load and the frequency of manifestations of myocardial ischemia during bicycle ergometry in relation to the prognostic value with regard to coronary heart disease (CHD) development. The studies involved 21 patients with myocardial infarction at the early recovery period and 23 CHD patients without a history of myocardial infarction. Manifestations of myocardial ischemia and the pattern of pyrophosphate build-up in the myocardium during exercise are approximately equally informative with regard to the prognosis of a high risk of complications in CHD patients. As regards the capacity to detect patients with a low risk of CHD complications, the finding of pyrophosphate 99mTc scintigraphy of the myocardium are more reliable than the electrocardiographic manifestations of myocardial ischemia or chest pain during bicycle ergometry. The parameters of the tolerance and adaptation to the load were found to be of little use in predicting CHD complications.

Adaptation, Physiological↗
PubMed2004

Minimal models of adapted neuronal response to in vivo-like input currents.

Rate models are often used to study the behavior of large networks of spiking neurons. Here we propose a procedure to derive rate models that take into account the fluctuations of the input current and firing-rate adaptation, two ubiquitous features in the central nervous system that have been previously overlooked in constructing rate models. The procedure is general and applies to any model of firing unit. As examples, we apply it to the leaky integrate-and-fire (IF) neuron, the leaky IF neuron with reversal potentials, and to the quadratic IF neuron. Two mechanisms of adaptation are considered, one due to an afterhyperpolarization current and the other to an adapting threshold for spike emission. The parameters of these simple models can be tuned to match experimental data obtained from neocortical pyramidal neurons. Finally, we show how the stationary model can be used to predict the time-varying activity of a large population of adapting neurons.

Action Potentials↗
PubMed1997

A novel role for HERG K+ channels: spike-frequency adaptation.

1. The regular firing of a Hodgkin-Huxley neurone endowed with fast Na+ and delayed K+ channels can be converted into adapting firing by appending HERG (human eag-related gene) channels. 2. The computer model predictions were verified by studying the firing properties of F-11 DRG neurone x neuroblastoma hybrid cells induced to differentiate by long-term exposure to retinoic acid. These cells, which express HERG currents (IHERG), show clear spike-frequency adaptation of their firing when current clamped with long depolarizations. 3. In agreement with the prediction, the selective blocking of IHERG by class III antiarrhythmic drugs always led to the disappearance of the spike-frequency adaptation, and the conversion of adapting firing to regular firing. 4. It is proposed that, in addition to their role in the repolarization of the heart action potential, HERG channels may sustain a process of spike-frequency adaptation, and hence contribute to the control of burst duration in a way that is similar to that of the K+ currents, IAHP, IC and IM. In addition to the known cardiac arrhythmia syndrome (LQT2), genetic mutations or an altered HERG expression could lead to continuous hyperexcitable states sustained by the inability of nerve or endocrine cells to accommodate to repetitive stimuli. This might help in clarifying the pathogenesis of still undefined idiopathic familial epilepsies.

Adaptation, Physiological↗
PubMed2006

Strengths and limitations of actuarial prediction of criminal reoffence in a German prison sample: a comparative study of LSI-R, HCR-20 and PCL-R.

Unlike many other countries, for many years, Germany disregarded structured instruments for assessing the risk of criminal reoffence. However, this negative attitude now seems to be gradually changing. An increasing number of contributions regarding structured instruments have been published in the German literature in the last years, and some instruments have already found their way into practice. However, studies that systematically examine the applicability of the mostly Anglo-American instruments to German criminals are still lacking. Therefore, the major objective of the current study was to test some internationally established procedures in a larger unselected sample from the German penal system. The following were included in the study: the Level of Service Inventory - Revised (LSI-R), the HCR-20 Scheme, and the Psychopathy Checklist - Revised (PCL-R). On the whole, the instruments proved to be applicable to German criminals with only a few adaptations to the German situation, and they achieved a predictive accuracy comparable to the values reported internationally. However, there were only minor differences in the predictive performance between the measures. Moreover, some basic limitations became apparent. Firstly, we found quite high percentages of criminals with medium scores and a correspondingly ambiguous prognosis. Furthermore, the predictive accuracy seemed to be dependent on demographic, criminological and psychopathological characteristics of the offenders. Finally, the instruments appeared to only partially utilize the empirical store of knowledge available regarding factors influencing the recidivism of criminals, since even a simple predictive model that only added a few further aspects besides the tested instruments (e. g. treatment yes or no) achieved systematically better predictions than the instruments alone. Altogether, the tested measures turned out to be useful instruments for risk assessments and may be conducive for a more systemized practice. However, due to the limitations inherent, they should be seen as a complement to a careful and clinically informed appraisal and not a substitute.

Actuarial Analysis↗