760 research outputs found

    Prospects for the Study of Evolution in the Deep Biosphere

    Get PDF
    Since the days of Darwin, scientists have used the framework of the theory of evolution to explore the interconnectedness of life on Earth and adaptation of organisms to the ever-changing environment. The advent of molecular biology has advanced and accelerated the study of evolution by allowing direct examination of the genetic material that ultimately determines the phenotypes upon which selection acts. The study of evolution has been furthered through examination of microbial evolution, with large population numbers, short generation times, and easily extractable DNA. Such work has spawned the study of microbial biogeography, with the realization that concepts developed in population genetics may be applicable to microbial genomes (Martiny et al., 2006; Manhes and Velicer, 2011). Microbial biogeography and adaptation has been examined in many different environments. Here we argue that the deep biosphere is a unique environment for the study of evolution and list specific factors that can be considered and where the studies may be performed. This publication is the result of the NSF-funded Center for Dark Energy Biosphere Investigations (C-DEBI) theme team on Evolution (www.darkenergybiosphere.org)

    The compositional and evolutionary logic of metabolism

    Full text link
    Metabolism displays striking and robust regularities in the forms of modularity and hierarchy, whose composition may be compactly described. This renders metabolic architecture comprehensible as a system, and suggests the order in which layers of that system emerged. Metabolism also serves as the foundation in other hierarchies, at least up to cellular integration including bioenergetics and molecular replication, and trophic ecology. The recapitulation of patterns first seen in metabolism, in these higher levels, suggests metabolism as a source of causation or constraint on many forms of organization in the biosphere. We identify as modules widely reused subsets of chemicals, reactions, or functions, each with a conserved internal structure. At the small molecule substrate level, module boundaries are generally associated with the most complex reaction mechanisms and the most conserved enzymes. Cofactors form a structurally and functionally distinctive control layer over the small-molecule substrate. Complex cofactors are often used at module boundaries of the substrate level, while simpler ones participate in widely used reactions. Cofactor functions thus act as "keys" that incorporate classes of organic reactions within biochemistry. The same modules that organize the compositional diversity of metabolism are argued to have governed long-term evolution. Early evolution of core metabolism, especially carbon-fixation, appears to have required few innovations among a small number of conserved modules, to produce adaptations to simple biogeochemical changes of environment. We demonstrate these features of metabolism at several levels of hierarchy, beginning with the small-molecule substrate and network architecture, continuing with cofactors and key conserved reactions, and culminating in the aggregation of multiple diverse physical and biochemical processes in cells.Comment: 56 pages, 28 figure

    Parent–Infant Room Sharing During the First Months of Life: Longitudinal Links With Behavior During Middle Childhood

    Get PDF
    Current recommendations encourage parent–infant room sharing for the first 6 months of life. This longitudinal study (N = 193) is the first to examine long-term relations of early room sharing with three domains of child behavior: sleep, behavior problems, and prosocial behavior. Information on room sharing was collected daily for infants’ first 6 months. At ages 6, 7, and 8 years, outcomes were assessed with maternal and teacher questionnaires and behavioral observations. Early room sharing was not related to sleep problems or behavior problems. Additionally, more weeks of room sharing were positively related to higher maternal ratings of child sleep quality and more prosocial behavior. In conclusion, early room sharing appears to be related to positive, but not negative, behavior outcomes in middle childhood.https://doi.org/10.1111/cdev.1314

    Mother-to-infant and father-to-infant initial emotional involvement

    Get PDF
    While infant attachment has been largely studied, parental attachment is still relatively unknown, especially when referred to fathers. However, it is mainly recognised that parents’ emotional involvement with the newborn contributes to the quality of the interaction and the care they provide. The aim of this study was to study mother-to-infant and father-to-infant initial emotional involvement; namely, differences between mothers and fathers and changes in mother’s emotions toward the neonate within the first days after delivery. The Bonding Scale, an extended Portuguese version of the ‘New Mother-to-Infant Bonding Scale’, was administered during the first two days after childbirth to a sample of 315 mothers and 141 fathers (n = 456), at the Júlio Dinis Maternity Hospital (Portugal). Most mothers and fathers show positive emotions and only a few of them showed negative emotions toward the infant. Maternal and paternal emotional involvement toward the newborn tend to be similar; nevertheless, fathers show less fear and better emotional involvement with the neonate, while mothers are sadder and show more emotions not related to bonding. During the first days following delivery, emotions not related to bonding, such as fear, seem to decrease in mothers.Bial Foundation - Grant 58/02.Human Development and Health Service of the Calouste Gulbenkian Foundation - Grant 48914

    Prospective organisation of neonatal arm movements : a motor foundation of embodied agency, disrupted in premature birth

    Get PDF
    Prospective motor control moves the body into the future, from where one is to where one wants to be. It is a hallmark of intentionality. But its origins in development is uncertain. In this study, we tested whether or not the arm movements of newborn infants were prospectively controlled. We measured the spatiotemporal organisation of 480 neonatal arm movements and 384 arm movements of infants prematurely born at-risk for neurodevelopmental disorder. We found 75% of healthy term-birth neonatal movements and 68% of prematurely-born infant movements conformed to the tauG-coupling model of prospective sensorimotor control. Prospective coupling values were significantly reduced in the latter (p = .010, r = .087). In both cases prospectively controlled movements were tightly organised by fixed-duration units with a base duration of 218 ms and additional temporal units of 145 ms. Yet distances remained constant. Thus, we demonstrate for the first time a precise prospective spatiotemporal organisation of neonatal arm movements and demonstrate at-risk infants exhibit reduced sensorimotor control. Prospective motor control is a hallmark of primary sensorimotor intentionality and gives a strong embodied foundation to conscious motor agency

    Evaluation of a new Rapid Antimicrobial Susceptibility system for Gram-negative and Gram-positive bloodstream infections: speed and accuracy of Alfred 60AST.

    Get PDF
    BACKGROUND: Blood stream infections (BSIs) are a major cause of morbidity and mortality. The time from taking blood cultures to obtain results of antibiotic sensitivity can be up to five days which impacts patient care. The Alfred 60 AST™ can reduce laboratory time from positive culture bottle to susceptibility results from 16 to 25 h to 5-6 h, transforming patient care. To evaluate the diagnostic accuracy of a rapid antimicrobial susceptibility system, the Alfred 60 AST™, in clinical isolates from patients with BSIs and confirm time to results. 301 Gram-negative and 86 Gram-positive isolates were analysed directly from positive blood culture bottles following Gram staining. Antimicrobial susceptibility results and time-to-results obtained by rapid Alfred 60 AST system and BD Phoenix were compared . RESULTS: A total of 2196 antimicrobial susceptibility test results (AST) were performed: 1863 Gram-negative and 333 Gram-positive. AST categorical agreement (CA) for Alfred 60 AST™ was 95% (1772/1863) for Gram-negative and 89% (295/333) for Gram-positive isolates. Gram-negative CA: ampicillin 96% (290/301); ciprofloxacin 95% (283/297); ceftriaxone 96% (75/78); meropenem 97% (288/297); piperacillin-tazobactam 95% (280/295); gentamicin 94% (279/297) and amikacin 93% (277/298). The median time to susceptibility results from blood culture flagging positive was 6.3 h vs 20 h (p < 0.01) for Alfred system vs BD Phoenix™. CONCLUSION: Alfred 60 AST system greatly reduced time to antimicrobial susceptibility results in Gram-negative and Gram-positive BSIs with good performance and cost, particularly for Gram-negative bacteraemia

    Infants’ behavioral and physiological profile and mother–infant interaction

    Get PDF
    This study aims to (a) identify and profile groups of infants according to their behavioral and physiological characteristics, considering their neurobehavioral organization, social withdrawal behavior, and endocrine reactivity to stress, and to (b) analyze group differences in the quality of mother–infant interaction. Ninety seven 8-week-old infants were examined using the Neonatal Behavioral Assessment Scale and the Alarm Distress Baby Scale. Cortisol levels were measured both before and after routine inoculation between 8 and 12 weeks. At 12 to 16 weeks mother–infant interaction was assessed using the Global Rating Scales of Mother–Infant Interaction. Three groups of infants were identified: (a) ‘‘withdrawn’’; (b) ‘‘extroverted’’; (c) ‘‘underaroused.’’ Differences between them were found regarding both infant and mother behaviors in the interaction and the overall quality of mother–infant interaction. The identification of behavioral and physiological profiles in infants is an important step in the study of developmental pathways

    Determinants of breastfeeding initiation within the first hour of life in a Brazilian population: cross-sectional study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Breastfeeding within the first hour of life is a potential mechanism for health promotion. The purpose of this study was to evaluate the prevalence of breastfeeding initiation within the first hour of life in Feira de Santana, Bahia, Brazil, between 2004 and 2005, and investigate the influence of maternal, child and prenatal factors on this practice.</p> <p>Methods</p> <p>This is a cross-sectional study extracted from the results of a contemporary cohort conducted in 10 maternity hospitals in the city of Feira de Santana, Bahia, Brazil. A group of 1,309 mother-child pairs was included in the study. Information about mother's and baby's characteristics, pregnancy, birth, and time of breastfeeding initiation was collected in the first 72 hours after delivery, through interview with mothers and hospital records. The data gathered were stored and analyzed using the SPSS 16.0 and R 8.0. The chi-square test and binary logistic regression analysis were used to examine the relationship between breastfeeding within the first hour and different variables.</p> <p>Results</p> <p>47.1% of the mothers initiated breastfeeding within the first hour after birth. Early initiation of breastfeeding was associated with birth at full term pregnancy (adjusted Prevalence Ratio 1.43; 95% confidence interval 1.10 to 2.00), mothers who received prenatal guidance regarding the advantages of breastfeeding (aPR1.23; 95% CI 1.11 to 1.41) and vaginal delivery (aPR 2.78; 95% CI 2.38 to 3.23).</p> <p>Conclusions</p> <p>In order to improve the rates of breastfeeding within the first hour of life, health care professionals must promote the factors favoring this practice such as prenatal guidance regarding the advantages of breastfeeding, vaginal delivery and full term birth, and stimulate this practice in vulnerable situations such as mothers with cesarean section and preterm birth.</p
    corecore