564 research outputs found
Survivability of Psychrobacter cryohalolentis K5 Under Simulated Martian Surface Conditions
Spacecraft launched to Mars can retain viable terrestrial microorganisms on board that may survive the interplanetary transit. Such biota might compromise the search for life beyond Earth if capable of propagating on Mars. The current study explored the survivability of Psychrobacter cryohalolentis K5, a psychrotolerant microorganism obtained from a Siberian permafrost cryopeg, under simulated martian surface conditions of high ultraviolet irradiation, high desiccation, low temperature, and low atmospheric pressure. First, a desiccation experiment compared the survival of P. cryohalolentis cells embedded, or not embedded, within a medium/salt matrix (MSM) maintained at 25 degrees C for 24 hr within a laminar flow hood. Results indicate that the presence of the MSM enhanced survival of the bacterial cells by 1 to 3 orders of magnitude. Second, tests were conducted in a Mars Simulation Chamber to determine the UV tolerance of the microorganism. No viable vegetative cells of P. cryohalolentis were detected after 8 hr of exposure to Mars-normal conditions of 4.55 W/m(2) UVC irradiation (200-280 nm), -12.5 degrees C, 7.1 mbar, and a Mars gas mix composed of CO2 (95.3%), N2 (2.7%), Ar (1.6%), O2 (0.2%), and H(2)O (0.03%). Third, an experiment was conducted within the Mars chamber in which total atmospheric opacities were simulated at tau = 0.1 (dust-free CO2 atmosphere at 7.1 mbar), 0.5 (normal clear sky with 0.4 = dust opacity and 0.1 = CO2-only opacity), and 3.5 (global dust storm) to determine the survivability of P. cryohalolentis to partially shielded UVC radiation. The survivability of the bacterium increased with the level of UVC attenuation, though population levels still declined several orders of magnitude compared to UVC-absent controls over an 8 hr exposure period
Heritability of aggression following social evaluation in middle childhood: An fMRI study.
Middle childhood marks an important phase for developing and maintaining social relations. At the
same time, this phase is marked by a gap in our knowledge of the genetic and environmental influences on brain responses to social feedback and their relation to behavioral aggression. In a large
developmental twin sample (509 7- to 9-year-olds), the heritability and neural underpinnings of
behavioral aggression following social evaluation were investigated, using the Social Network
Aggression Task (SNAT). Participants viewed pictures of peers that gave positive, neutral, or negative feedback to the participantās profile. Next, participants could blast a loud noise toward the
peer as an index of aggression. Genetic modeling revealed that aggression following negative feedback was influenced by both genetics and environmental (shared as well as unique environment).
On a neural level (n 5 385), the anterior insula and anterior cingulate cortex gyrus (ACCg)
responded to both positive and negative feedback, suggesting they signal for social salience cues.
The medial prefrontal cortex (mPFC) and inferior frontal gyrus (IFG) were specifically activated during negative feedback, whereas positive feedback resulted in increased activation in caudate,
supplementary motor cortex (SMA), and dorsolateral prefrontal cortex (DLPFC). Decreased SMA
and DLPFC activation during negative feedback was associated with more aggressive behavior
aft
Disorganized attachment in early childhood: meta-analysis of precursors, concomitants, and sequelae
FSW - Gezinsopvoeding - Ou
Narrowing the Transmission Gap: A Synthesis of Three Decades of Research on Intergenerational Transmission of Attachment
wenty years ago, meta-analytic results (k = 19) confirmed the association between caregiver attachment representations and childācaregiver attachment (Van IJzendoorn, 1995). A test of caregiver sensitivity as the mechanism behind this intergenerational transmission showed an intriguing ātransmission gap.ā Since then, the intergenerational transmission of attachment and the transmission gap have been studied extensively, and now extend to diverse populations from all over the globe. Two decades later, the current review revisited the effect sizes of intergenerational transmission, the heterogeneity of the transmission effects, and the size of the transmission gap. Analyses were carried out with a total of 95 samples (total N = 4,819). All analyses confirmed intergenerational transmission of attachment, with larger effect sizes for secure-autonomous transmission (r = .31) than for unresolved transmission (r = .21), albeit with significantly smaller effect sizes than 2 decades earlier (r = .47 and r = .31, respectively). Effect sizes were moderated by risk status of the sample, biological relatedness of childācaregiver dyads, and age of the children. Multivariate moderator analyses showed that unpublished and more recent studies had smaller effect sizes than published and older studies. Path analyses showed that the transmission could not be fully explained by caregiver sensitivity, with more recent studies narrowing but not bridging the ātransmission gap.ā Implications for attachment theory as well as future directions for research are discussed. (PsycINFO Database Record (c) 2015 APA, all rights reserved)
Effective preventive interventions to support parents of young children: Illustrations from the Video-feedback Intervention to promote Positive Parenting and Sensitive Discipline (VIPP-SD)
Development Psychopathology in context: famil
Parenting, young children\u27s behavioral selfāregulation and the quality of their peer relationships
The quality of young children\u27s peer relationships is important for their development, and it is assumed that parenting and self-regulation skills shape children\u27s behavior when interacting with peers. In this multi-informant-multi-method study, we examined the direct and mediated associations between preschool parenting, children\u27s behavioral self-regulation, and peer aggression and peer relationship problems in elementary school-aged children and extended previous work by examining both positive and negative parenting of both mothers and fathers. In a large community sample (n = 698) of parents and children who were between 1 and 6 years old, we obtained information on observed maternal sensitivity, mother- and father-reported harsh discipline, observed child self-regulation, and child-reported aggression towards peers, peer rejection and victimization. Results from a structural equation model showed that maternal sensitivity was prospectively associated with children\u27s behavioral self-regulation and that lower levels of behavioral self-regulation were associated with higher levels of children\u27s peer aggression and peer relationship problems. However, children\u27s behavioral self-regulation did not mediate the association between maternal sensitivity and peer relationship problems. In addition, higher levels of paternal, but not maternal, harsh discipline were directly associated with more peer relationship problems, but again no mediation was found. The results highlight the importance of maternal sensitivity for children\u27s behavioral self-regulation and the role of paternal harsh discipline for the quality of children\u27s later peer relationships. Our findings suggest it is important to take maternal and paternal parenting practices into account as they might have different effects on the child
The role of supportive parenting and stress reactivity in the development of self-regulation in early childhood
Maternal sensitivity and supportive discipline are important determinants of child self-regulation. Some evidence suggests that specific genetic or temperamental markers determine childrenās susceptibility to the impact of maternal parenting on child self-regulation. Cortisol reactivity as a susceptibility marker moderating the relation between maternal parenting and child self-regulation has not yet been studied. In this longitudinal population-based study (N = 258), the moderating role of infant cortisol stress response to the Strange Situation Procedure at age 1 was examined in the association between parenting (sensitivity and supportive discipline) at age 3 and child self-regulation at age 3 and 4. Maternal sensitivity and supportive discipline were related to child immediate and prolonged delay of gratification at age 3, and maternal sensitivity was related to working memory skills at age 4. No evidence of differential susceptibility to maternal parenting was found, based on differences in infant cortisol stress response
Prenatal Maternal Stress and Child IQ
The evidence for negative influences of maternal stress during pregnancy on child cognition remains inconclusive. This study tested the association between maternal prenatal stress and child intelligence in 4,251 motherāchild dyads from a multiethnic population-based cohort in the Netherlands. A latent factor of prenatal stress was constructed, and child IQ was tested at age 6Ā years. In Dutch and Caribbean participants, prenatal stress was not associated with child IQ after adjustment for maternal IQ and socioeconomic status. In other ethnicities no association was found; only in the Moroccan/Turkish group a small negative association between prenatal stress and child IQ was observed. These results suggest that prenatal stress does not predict child IQ, except in children from less acculturated minority groups
Behavioral genetics of temperament and frontal asymmetry in early childhood
Temperament has been suggested to be influenced by genetic and environmental factors. The current study examined genetic shared environmental and unique environmental factors accounting for variation in Fear, Effortful Control (EC), and Frontal Asymmetry (FA) in 4- to 6-year-old children using bivariate behavioral genetic modeling. We included a total of 214 same-sex twin pairs: 127 monozygotic (MZ) and 87 dizygotic (DZ) pairs. FA was measured during a rest electroencephalogram (EEG) recording, and Fear and EC were measured using parent report. Results show that differences between twins were best explained by genetic factors (about a quarter of the variance) and unique environmental factors (about three quarters of the variance). However, the cross-trait, within-twin correlations were not significant, implying no overlapping genetic or environmental factors on Fear and EC or on Fear and FA. Future research should try to elucidate the large role of unique environmental factors in explaining variance in these temperament-related traits
- ā¦