1,305 research outputs found
Age differences in learning emerge from an insufficient representation of uncertainty in older adults
Healthy aging can lead to impairments in learning that affect many laboratory
and real-life tasks. These tasks often involve the acquisition of dynamic
contingencies, which requires adjusting the rate of learning to environmental
statistics. For example, learning rate should increase when expectations are
uncertain (uncertainty), outcomes are surprising (surprise) or contingencies
are more likely to change (hazard rate). In this study, we combine
computational modelling with an age-comparative behavioural study to test
whether age-related learning deficits emerge from a failure to optimize
learning according to the three factors mentioned above. Our results suggest
that learning deficits observed in healthy older adults are driven by a
diminished capacity to represent and use uncertainty to guide learning. These
findings provide insight into age-related cognitive changes and demonstrate
how learning deficits can emerge from a failure to accurately assess how much
should be learned
Development of peach flower buds under low winter chilling conditions
Here, we reviewed both endogenous and exogenous factors involved in the processes of flower bud formation and flower development in peach, analyzing how they can be affected by climatic change in temperate zones, explored the expansion of peach to tropical or subtropical zones. The process of flower bud formation in peach differs between low winter chilling and temperate conditions. Although the main steps of flower development are maintained, the timing in which each one occurs is different, and some processes can be altered under low winter chilling conditions, with a great impact on fruit production and crop management. Further studies on flower bud induction and differentiation under warmer conditions are fundamental for addressing the alterations in flower bud development that negatively impact on next season’s harvest. In the future, horticulturalists and scientists will face several challenges, mainly how high temperatures affect the expression of the main genes regulating flower formation and how to improve crop management in these conditions
Finding and counting vertex-colored subtrees
The problems studied in this article originate from the Graph Motif problem
introduced by Lacroix et al. in the context of biological networks. The problem
is to decide if a vertex-colored graph has a connected subgraph whose colors
equal a given multiset of colors . It is a graph pattern-matching problem
variant, where the structure of the occurrence of the pattern is not of
interest but the only requirement is the connectedness. Using an algebraic
framework recently introduced by Koutis et al., we obtain new FPT algorithms
for Graph Motif and variants, with improved running times. We also obtain
results on the counting versions of this problem, proving that the counting
problem is FPT if M is a set, but becomes W[1]-hard if M is a multiset with two
colors. Finally, we present an experimental evaluation of this approach on real
datasets, showing that its performance compares favorably with existing
software.Comment: Conference version in International Symposium on Mathematical
Foundations of Computer Science (MFCS), Brno : Czech Republic (2010) Journal
Version in Algorithmic
Feasibilty of Transcutaneous pCO2 Monitoring During Immediate Transition After Birth\u2014A Prospective Observational Study
Background: According to recommendations, non-invasive monitoring during neonatal resuscitation after birth includes heart rate (HR) and oxygen saturation (SpO2). Continuous transcutaneous monitoring of carbon dioxide partial pressure (tcpCO2) may further offer quantitative information on neonatal respiratory status. Objective: We aimed to investigate feasibility of tcpCO2 measurements in the delivery room during immediate neonatal transition and to compare the course of tcpCO2 between stable term and preterm infants. Methods: Neonates without need for cardio-respiratory intervention during immediate transition after birth were enrolled in a prospective observational study. In these term and preterm neonates, we measured HR and SpO2 by pulse oximetry on the right wrist and tcpCO2 with the sensor applied on the left hemithorax during the first 15 min after birth. Courses of tcpCO2 were analyzed in term and preterm neonates and groups were compared. Results: Fifty-three term (gestational age: 38.8 \ub1 0.9 weeks) and 13 preterm neonates (gestational age: 34.1 \ub1 1.5 weeks) were included. First tcpCO2 values were achieved in both groups at minute 4 after birth, which reached a stable plateau after the equilibration phase at minute 9. Mean tcpCO2 values 15 min after birth were 46.2 (95% CI 34.5\u201357.8) mmHg in term neonates and 48.5 (95%CI 43.0\u201354.1) mmHg in preterm neonates. Preterm and term infants did not show significant differences in the tcpCO2 values at any time point. Conclusion: This study demonstrates that tcpCO2 measurement is feasible during immediate neonatal transition after birth and that tcpCO2 values were comparable in stable term and preterm neonates
Impact of bradycardia and hypoxemia on oxygenation in preterm infants requiring respiratory support at birth
Aim of the study: Analysis of the impact of bradycardia and hypoxemia on the course of cerebral and peripheral oxygenation parameters in preterm infants in need for respiratory support during foetal-to-neonatal transition. Methods: The first 15 min after birth of 150 preterm neonates in need for respiratory support born at the Division of Neonatology, Graz (Austria) were analyzed. Infants were divided into different groups according to duration of bradycardia exposure (no Bradycardia, brief bradycardia <2 min, and prolonged bradycardia 652 min) and to systemic oxygen saturation (SpO2) value at 5 min of life (<80% or 6580%). Analysis was performed considering the degree of bradycardia alone (step 1) and in association with the presence of hypoxemia (step 2). Results: In step 1, courses of SpO2 differed significantly between bradycardia groups (p = 0.002), while courses of cerebral regional oxygen saturation (crStO2) and cerebral fractional tissue oxygen extraction (cFTOE) were not influenced (p = 0.382 and p = 0.878). In step 2, the additional presence of hypoxemia had a significant impact on the courses of SpO2 (p < 0.001), crStO2 (p < 0.001) and cFTOE (p = 0.045). Conclusion: Our study shows that the degree of bradycardia has a significant impact on the course of SpO2 only, but when associated with the additional presence of hypoxemia a significant impact on cerebral oxygenation parameters was seen (crStO2, cFTOE). Furthermore, the additional presence of hypoxemia has a significant impact on FiO2 delivered. Our study emphasizes the importance of HR and SpO2 during neonatal resuscitation, underlining the relevance of hypoxemia during the early transitional phase
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