3,704 research outputs found
Not talking about sex : indirect parental communication and risky adolescent sexual behavior
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on August 11, 2009)Thesis (M.A.) University of Missouri-Columbia 2008.The present study presents a newly adapted measure of participant reported indirect parental sexual communication. Undergraduate psychology students (N=297) were given an online survey which was utilized to investigate the relationship between participant reported indirect parental sexual communication and self-reported risky adolescent sexual behavior. This relationship was investigated to determine if it is mediated by adolescent perception of parental attitudes and whether various demographic variables act as moderators. The goal of the study was to begin to clarify the influence of participant perceived indirect parental sexual communication on risky adolescent sexual behavior so that interventions to reduce risk may be developed in the future.Includes bibliographical reference
Phase Diagrams of Quasispecies Theory with Recombination and Horizontal Gene Transfer
We consider how transfer of genetic information between individuals
influences the phase diagram and mean fitness of both the Eigen and the
parallel, or Crow-Kimura, models of evolution. In the absence of genetic
transfer, these physical models of evolution consider the replication and point
mutation of the genomes of independent individuals in a large population. A
phase transition occurs, such that below a critical mutation rate an
identifiable quasispecies forms. We generalize these models of quasispecies
evolution to include horizontal gene transfer. We show how transfer of genetic
information changes the phase diagram and mean fitness and introduces
metastability in quasispecies theory, via an analytic field theoretic mapping.Comment: 5 pages, 1 figure, to appear in Physics Review Letter
The Nonlinear Evolution of Instabilities Driven by Magnetic Buoyancy: A New Mechanism for the Formation of Coherent Magnetic Structures
Motivated by the problem of the formation of active regions from a
deep-seated solar magnetic field, we consider the nonlinear three-dimensional
evolution of magnetic buoyancy instabilities resulting from a smoothly
stratified horizontal magnetic field. By exploring the case for which the
instability is continuously driven we have identified a new mechanism for the
formation of concentrations of magnetic flux.Comment: Published in ApJL. Version with colour figure
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Sample preparation for point of care molecular diagnostics of STIs
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Brunel DoCLab is part of the esti2 consortium developing electronic self-testing instruments for sexually transmitted infections using nucleic acid amplification testing (NAAT). A proprietary sample collection device has been designed to integrate directly with a microfluidic cartridge. Cell lysis was conducted using a chemical method and nucleic acid purification was done on an activated cellulose membrane. The microfluidic device incorporates passive mixing of the lysis-binding buffers and sample. Preliminary results have shown extraction efficiencies for this new membrane of 69% and 57% compared to the commercial Qiagen extraction method of 85% and 59.4% for 0.1ng/μL and 100ng/μL salmon sperm DNA spiked in phosphate buffered solution. Preliminary extraction experiments in the passive mixer cartridges with lysis and nucleic acid purification showed extraction efficiency around 80% of the commercial Qiagen kit. Isothermal amplification was conducted using thermophillic helicase dependant amplification. A low cost benchtop real-time isothermal amplification platform has been developed capable of running six amplifications simultaneously. Work to integrate sample collection, nucleic acid extraction and isothermal amplification is currently underway
Metastability and anomalous fixation in evolutionary games on scale-free networks
We study the influence of complex graphs on the metastability and fixation
properties of a set of evolutionary processes. In the framework of evolutionary
game theory, where the fitness and selection are frequency-dependent and vary
with the population composition, we analyze the dynamics of snowdrift games
(characterized by a metastable coexistence state) on scale-free networks. Using
an effective diffusion theory in the weak selection limit, we demonstrate how
the scale-free structure affects the system's metastable state and leads to
anomalous fixation. In particular, we analytically and numerically show that
the probability and mean time of fixation are characterized by stretched
exponential behaviors with exponents depending on the network's degree
distribution.Comment: 5 pages, 4 figures, to appear in Physical Review Letter
Statistical Properties of Height of Japanese Schoolchildren
We study height distributions of Japanese schoolchildren based on the
statictical data which are obtained from the school health survey by the
ministry of education, culture, sports, science and technology, Japan . From
our analysis, it has been clarified that the distribution of height changes
from the lognormal distribution to the normal distribution in the periods of
puberty.Comment: 2 pages, 2 figures, submitted to J. Phys. Soc. Jpn.; resubmitted to
J. Phys. Soc. Jpn. after some revisio
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