3,301 research outputs found

    Local cluster aggregation models of explosive percolation

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    We introduce perhaps the simplest models of graph evolution with choice that demonstrate discontinuous percolation transitions and can be analyzed via mathematical evolution equations. These models are local, in the sense that at each step of the process one edge is selected from a small set of potential edges sharing common vertices and added to the graph. We show that the evolution can be accurately described by a system of differential equations and that such models exhibit the discontinuous emergence of the giant component. Yet, they also obey scaling behaviors characteristic of continuous transitions, with scaling exponents that differ from the classic Erdos-Renyi model.Comment: Final version as appearing in PR

    Effectiveness of Childbirth Education on Nulliparous Women’s Knowledge of Childbirth Preparation, Pregnancy Anxiety and Pregnancy Outcomes

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    Background: The emerging number of cesarean sections among nulliparous women due to high pregnancy-related anxiety is a major concern of maternity care providers. Childbirth preparations enable women to cope with pregnancy anxiety and enhance pregnancy outcomes. Limited studies evaluated the impact of childbirth educational interventions on pregnancy-specific anxiety and pregnancy outcomes. Objectives: The aim of this study was to evaluate the effectiveness of childbirth educational intervention on nulliparous women’s knowledge on childbirth preparation, pregnancy anxiety, and pregnancy outcomes. Methods: A randomized controlled trial approach with a two-group pretest/ posttest design was used among hundred nulliparous third trimester pregnant women. All participants were pretested for their knowledge on childbirth preparation and pregnancy anxiety level using knowledge questionnaire, state trait anxiety inventory, and pregnancy-specific anxiety inventory. The experimental group (n = 50) received three sessions of childbirth education. All participants were post- tested before delivery, and their pregnancy outcomes were noted from labor records. Data were collected from a major maternity hospital in Kerala, India. GLM repeated measures analysis and paired t-test were used for data analysis. Results: The experimental group demonstrated a significantly higher level of knowledge on childbirth preparation (P < 0.001), with high reported mean knowledge scores of (54.30 ± 3.86) childbirth preparation than the control group (31.08 ± 1.96). A lower mean scores of pregnancy-specific anxiety among experimental group (102 ± 4.65) (P < 0.001) compared to control group (139.96 ± 4.9) signifies the relevance of childbirth education in reducing pregnancy-specific anxiety. Significant reductions of caesarean birth (50%) among nulliparous women along with a 12% increase in newborn’s birth weights were the main positive birth outcomes. Conclusions: Childbirth education significantly reduced pregnancy-specific anxiety and the adverse pregnancy outcomes. The emerging number of cesarean sections on maternal request due to childbirth anxiety could be reduced by empowering nulliparous women through childbirth education

    Preon Prophecies by the Standard Model

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    The Standard Model of quarks and leptons is, at first sight, nothing but a set of {\it ad hoc} rules, with no connections, and no clues to their true background. At a closer look, however, there are many inherent prophecies that point in the same direction: {\it Compositeness} in terms of three stable preons.Comment: 13 pages, 8 eps-figures, invited talk at Beyond the Desert '03, Schloss Ringberg, Bavaria, June 2003; to be published in the Proceeding

    Environmental and genetic influences on neurocognitive development: the importance of multiple methodologies and time-dependent intervention

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    Genetic mutations and environmental factors dynamically influence gene expression and developmental trajectories at the neural, cognitive, and behavioral levels. The examples in this article cover different periods of neurocognitive development—early childhood, adolescence, and adulthood—and focus on studies in which researchers have used a variety of methodologies to illustrate the early effects of socioeconomic status and stress on brain function, as well as how allelic differences explain why some individuals respond to intervention and others do not. These studies highlight how similar behaviors can be driven by different underlying neural processes and show how a neurocomputational model of early development can account for neurodevelopmental syndromes, such as autism spectrum disorders, with novel implications for intervention. Finally, these studies illustrate the importance of the timing of environmental and genetic factors on development, consistent with our view that phenotypes are emergent, not predetermined

    Performance Analysis of Mesh-based NoC’s on Routing Algorithms

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    The advent of System-on-Chip (SoCs), has brought about a need to increase the scale of multi-core chip networks. Bus Based communications have proved to be limited in terms of performance and ease of scalability, the solution to both bus – based and Point-to-Point (P2P) communication systems is to use a communication infrastructure called Network-on-Chip (NoC). Performance of NoC depends on various factors such as network topology, routing strategy and switching technique and traffic patterns. In this paper, we have taken the initiative to compile together a comparative analysis of different Network on Chip infrastructures based on the classification of routing algorithm, switching technique, and traffic patterns. The goal is to show how varied combinations of the three factors perform differently based on the size of the mesh network, using NOXIM, an open source SystemC Simulator of mesh-based NoC. The analysis has shown tenable evidence highlighting the novelty of XY routing algorithm

    Physical volcanology and geochemistry of Paleoarchean komatiite lava flows from the western Dharwar craton, southern India: Implications. for Archean mantle evolution and continental growth.

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    Palaeoarchaean (3.38–3.35 Ga) komatiites from the Jayachamaraja Pura (J.C. Pura) and Banasandra greenstone belts of the western Dharwar craton, southern India were erupted as submarine lava flows. These high-temperature (1450–1550°C), low-viscosity lavas produced thick, massive, polygonal jointed sheet flows with sporadic flow top breccias. Thick olivine cumulate zones within differentiated komatiites suggest channel/conduit facies. Compound, undifferentiated flow fields developed marginal-lobate thin flows with several spinifex-textured lobes. Individual lobes experienced two distinct vesiculation episodes and grew by inflation. Occasionally komatiite flows form pillows and quench fragmented hyaloclastites. J.C. Pura komatiite lavas represent massive coherent facies with minor channel facies, whilst the Bansandra komatiites correspond to compound flow fields interspersed with pillow facies. The komatiites are metamorphosed to greenschist facies and consist of serpentine-talc ± carbonate, actinolite–tremolite with remnants of primary olivine, chromite, and pyroxene. The majority of the studied samples are komatiites (22.46–42.41 wt.% MgO) whilst a few are komatiitic basalts (12.94–16.18 wt.% MgO) extending into basaltic (7.71 – 10.80 wt.% MgO) composition. The studied komatiites are Al-depleted Barberton type whilst komatiite basalts belong to the Al-undepleted Munro type. Trace element data suggest variable fractionation of garnet, olivine, pyroxene, and chromite. Incompatible element ratios (Nb/Th, Nb/U, Zr/Y Nb/Y) show that the komatiites were derived from heterogeneous sources ranging from depleted to primitive mantle. CaO/Al2O3 and (Gd/Yb)N ratios show that the Al-depleted komatiite magmas were generated at great depth (350–400 km) by 40–50% partial melting of deep mantle with or without garnet (majorite?) in residue whilst komatiite basalts and basalts were generated at shallow depth in an ascending plume. The widespread Palaeoarchaean deep depleted mantle-derived komatiite volcanism and sub-contemporaneous TTG accretion implies a major earlier episode of mantle differentiation and crustal growth during ca. 3.6–3.8 Ga

    Network Growth with Feedback

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    Existing models of network growth typically have one or two parameters or strategies which are fixed for all times. We introduce a general framework where feedback on the current state of a network is used to dynamically alter the values of such parameters. A specific model is analyzed where limited resources are shared amongst arriving nodes, all vying to connect close to the root. We show that tunable feedback leads to growth of larger, more efficient networks. Exact results show that linear scaling of resources with system size yields crossover to a trivial condensed state, which can be considerably delayed with sublinear scaling.Comment: 4 pages, 4 figure
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