Natural Evolution (natural + evolution)

Distribution by Scientific Domains


Selected Abstracts


Natural evolution of regurgitation in healthy infants

ACTA PAEDIATRICA, Issue 7 2009
Badriul Hegar
Abstract Objectives:, To determine the natural history of infant regurgitation during the first year of life. Methods: Parents recorded prospectively the frequency of regurgitation for 1 week before consultation during the first year of life. A sub-group analysis according to the method of feeding was planned. Results:, A total of 130 infants of an original sample of 163 (80%) newborns were followed up for 1 year. Daily spilling was highest during the first month of life (73%) and decreased gradually to 50% during the fifth month of life. During the first 2 months of life, 20% of the infants regurgitated more than four times per day. After the age of 12 months, only 4% of the infants had daily regurgitations. Exclusively breastfed infants did regurgitate less than partially breastfed infants. Weight gain was influenced by the frequency of regurgitation, especially in partially breastfed infants. Conclusion: Regurgitation in infancy is common, decreasing from birth, and tends to disappear by 12 months of age. Weight gain during the first 4 months of life is decreased in infants who regurgitate more than four times a day. Our data suggest that exclusively breastfed infants regurgitate less than partially breastfed babies. [source]


Changes in Mini Mental State Examination score after stroke: lacunar infarction predicts cognitive decline

EUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2006
P. Appelros
Stroke and cognitive impairment are inter-related. The purpose of this study was to show the natural evolution of cognitive performance during the first year after a stroke, and to show which factors that predict cognitive decline. Subjects were patients with a first-ever stroke who were treated in a stroke unit. A total of 160 patients were included. At baseline patients were evaluated with regard to stroke type, stroke severity, pre-stroke dementia and other risk factors. Mini Mental State Examinations (MMSE) were performed after 1 week and after 1 year. Patients had a median increase of 1 point (range ,8 to +9) on the MMSE. Thirty-two pre cent of the patients deteriorated, 13% were unchanged, and 55% improved. Lacunar infarction (LI) and left-sided stroke were associated with a failure to exhibit improvement. Patients with LI had an average decline of 1.7 points, whilst patients with other stroke types had an average increase of 1.8 points. Most stroke survivors improve cognitively during the first year after the event. The outcome for LI patients is worse, which suggests that LI may serve as a marker for concomitant processes that cause cognitive decline. [source]


Assessing the predictive performance of artifIcial neural network-based classifiers based on different data preprocessing methods, distributions and training mechanisms

INTELLIGENT SYSTEMS IN ACCOUNTING, FINANCE & MANAGEMENT, Issue 4 2005
Adrian Costea
We analyse the implications of three different factors (preprocessing method, data distribution and training mechanism) on the classification performance of artificial neural networks (ANNs). We use three preprocessing approaches: no preprocessing, division by the maximum absolute values and normalization. We study the implications of input data distributions by using five datasets with different distributions: the real data, uniform, normal, logistic and Laplace distributions. We test two training mechanisms: one belonging to the gradient-descent techniques, improved by a retraining procedure, and the other is a genetic algorithm (GA), which is based on the principles of natural evolution. The results show statistically significant influences of all individual and combined factors on both training and testing performances. A major difference with other related studies is the fact that for both training mechanisms we train the network using as starting solution the one obtained when constructing the network architecture. In other words we use a hybrid approach by refining a previously obtained solution. We found that when the starting solution has relatively low accuracy rates (80,90%) the GA clearly outperformed the retraining procedure, whereas the difference was smaller to non-existent when the starting solution had relatively high accuracy rates (95,98%). As reported in other studies, we found little to no evidence of crossover operator influence on the GA performance. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Responding to society's needs: Prescription privileges for psychologists

JOURNAL OF CLINICAL PSYCHOLOGY, Issue 6 2002
Mary Ann Norfleet
The health care revolution has contributed to the natural evolution of the role of psychologists. This has led to the necessity for future psychologists to have the authority to prescribe psychotropic medications in order to offer the best-available, comprehensive treatment to the public. Psychologists' training gives them a unique role in addressing the psychosocial aspects of medical problems, in collaboration with primary-care physicians. Prescribing psychologists are cost-effective, many practice in rural areas where people have no other access to mental health care, and they will be able to treat other underserved populations such as the poor, the elderly, the chronically mentally ill, children, and prisoners in the criminal justice system. Prescribing psychologists will have an increasingly prominent role in future health care policy decisions and practice. © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 599,610, 2002. [source]


The Influence of Local Urban Containment Policies and Statewide Growth Management on the Size of United States Urban Areas,

JOURNAL OF REGIONAL SCIENCE, Issue 1 2006
Robert W. Wassmer
This paper describes a regression-based analysis that finds that different forms of these policies are achieving their desired goal of shrinking the square mile size of an urban area. A comparison of the influence of the various forms of urban containment and growth management policies with other "natural evolution,""flight from blight," and "fiscalization of land use" factors that also influence the square mile size of an urban area is made, and policy implications are offered. [source]


A Polylinker Approach to Reductive Loop Swaps in Modular Polyketide Synthases

CHEMBIOCHEM, Issue 16 2008
Laurenz Kellenberger Dr.
Abstract Multiple versions of the DEBS 1-TE gene, which encodes a truncated bimodular polyketide synthase (PKS) derived from the erythromycin-producing PKS, were created by replacing the DNA encoding the ketoreductase (KR) domain in the second extension module by either of two synthetic oligonucleotide linkers. This made available a total of nine unique restriction sites for engineering. The DNA for donor "reductive loops," which are sets of contiguous domains comprising either KR or KR and dehydratase (DH), or KR, DH and enoylreductase (ER) domains, was cloned from selected modules of five natural PKS multienzymes and spliced into module 2 of DEBS 1-TE using alternative polylinker sites. The resulting hybrid PKSs were tested for triketide production in vivo. Most of the hybrid multienzymes were active, vindicating the treatment of the reductive loop as a single structural unit, but yields were dependent on the restriction sites used. Further, different donor reductive loops worked optimally with different splice sites. For those reductive loops comprising DH, ER and KR domains, premature TE-catalysed release of partially reduced intermediates was sometimes seen, which provided further insight into the overall stereochemistry of reduction in those modules. Analysis of loops containing KR only, which should generate stereocentres at both C-2 and C-3, revealed that the 3-hydroxy configuration (but not the 2-methyl configuration) could be altered by appropriate choice of a donor loop. The successful swapping of reductive loops provides an interesting parallel to a recently suggested pathway for the natural evolution of modular PKSs by recombination. [source]


Need for hospice and palliative care services in patients with end-stage heart failure treated with intermittent infusion of inotropes

CLINICAL CARDIOLOGY, Issue 1 2004
Angel López-Candales M.D. FACC
Abstract Background: Hospice and palliative care programs to relieve suffering and optimize management of terminally ill patients have grown rapidly in the United States. However, there are no data on the need for these services among patients with end-stage heart failure receiving intermittent infusion of intravenous inotropes. Hypothesis: The need for hospice and palliative care programs among patients in end-stage heart failure who receive intermittent infusion of inotropes is investigated. Methods: The study included all stable patients with refractory heart failure symptoms treated with inotropes in our outpatient unit. A total of 73 patients (65 ± 12years; left ventricular ejection fraction 22 ± 9%; New York Heart Association class 3.6 ± 0.4) were seen during a 49-month period. Of these, 3 5 patients (48%) met hospice or palliative care evaluation criteria upon referral but were offered, and accepted, the alternative of parenteral inotropes. In all, 1,737 individual outpatient treatment sessions were given, with a mean of 24 ± 19 sessions per patient (range 5 to 118 sessions), representing a minimum of 9,948 h of inotrope therapy. Results: A total of 18 (25%) patients died, 6 (8%) patients were withdrawn from the program (3 by their primary physicians and 3 because of significant travel limitations); 4 (5%) patients required continuous intravenous home therapy; and 44 (61%) patients were discharged with significant improvement in their heart failure symptoms. Only 7 of the 18 patients who died had received hospice or palliative care intervention, mainly for the sake of comfort and to ease the transition among family members. The rest of the patients were comfortable and had accepted the natural evolution of their disease; they were not interested in or did not require hospice or palliative care intervention. Of the patients discharged from the outpatient cardiac infusion unit, the interval free of heart failure symptoms after the final infusion treatment ranged from 201 to 489 days, with no need for hospitalization or emergency room visits. Conclusion: Our results demonstrate that intermittent infusion of intravenous inotropes can be safely administered and can improve symptoms in a significant number of patients, probably by slowing the natural progression of heart failure. Although the full clinical impact of inotrope therapy in an outpatient setting has not been fully defined, other nonhemodynamic-related benefits should be sought and investigated. Our results suggest that intermittent infusion of intravenous inotropes is one of the prominent variables that requires particular attention. In our experience, the institution of intermittent infusions of intravenous inotropes can, in fact, modify end-stage heart failure symptoms that, in most patients, are currently perceived to lead to a terminal event. Thus, appropriate use of intermittent infusion of intravenous inotropes may not only improve functional class and symptoms in a significant number of patients identified as terminal by their poor response to conventional therapy, but it may also facilitate better utilization of hospice and palliative care resources among patients with end-stage heart failure. Furthermore, the need for hospice and palliative care in patients with heart failure should be revisited in view of adjuvant treatment options such as intermittent infusion of intravenous inotropes. [source]