321 research outputs found
Multiple genome-wide analyses of smoking behavior in the Framingham Heart Study
BACKGROUND: Cigarette smoking behavior may have a genetic basis. We assessed evidence for quantitative trait loci (QTLs) affecting the maximum number of cigarettes smoked per day, a trait meant to quantify this behavior, using data collected over 40 years as part of the Framingham Heart Study's original and offspring cohorts. RESULTS: Heritability was estimated to be approximately 21% using variance components (VC) methods (SOLAR), while oligogenic linkage and segregation analysis based on Bayesian Markov chain Monte Carlo (MCMC) methods (LOKI) estimated a mean of two large QTLs contributing approximately 28% and 20%, respectively, to the trait's variance. Genome-wide parametric (FASTLINK) and VC linkage analyses (SOLAR) revealed several LOD scores greater than 1.0, with peak LOD scores using both methods on chromosomes 2, 17, and 20; multi-point MCMC methods followed up on these chromosomes. The most robust linkage results were for a QTL between 65 and 84 cM on chromosome 20 with signals from multiple sex- and age-adjusted analyses including two-point LOD scores of 1.30 (parametric) and 1.07 (heritability = 0.17, VC) at 70.51 cM, a multi-point LOD score of 1.50 (heritability = 0.20, VC) at 84 cM, and an intensity ratio of 12.0 (MCMC) at 65 cM. CONCLUSION: Familial aggregation of the maximum number of cigarettes smoked per day was consistent with a genetic component to this behavior, and oligogenic segregation analyses using MCMC suggested two important QTLs. Linkage signals on chromosome 20 between 65 and 84 cM were seen using multiple analytical methods. No linkage result, however, met genome-wide statistical significance criteria, and the true relationship between these regions and smoking behavior remains unclear
Perceptions of Licensure: A Survey of Michigan Genetic Counselors
This study by the Michigan Genetic Counselor Licensure Committee is the first known published documentation of genetic counselors’ beliefs and attitudes about licensure. The response rate from genetic counselors in Michigan was 66% (41/62). Ninety‐five percent of respondents were supportive of licensure. Respondents believed licensure would legitimize genetic counseling as a distinct allied healthcare profession (97.5%), increase the public’s protection (75%), and allow genetic counselors to practice independently (67%). While 45% felt licensure would increase counselor involvement in lawsuits, this did not impact licensure support (p = 0.744). Opinions were split regarding physician supervision and ordering tests. Even though 28% favored physician supervision, there was overwhelming support for genetic counselors performing some components of genetic testing (95%) and ordering some types of genetic tests (82%) independent of a physician. Use of this survey may be helpful in other states to assess genetic counselors’ interest in licensure and for drafting legislation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147114/1/jgc40357.pd
Kaon Production and Interaction
Exclusive data on both the elementary kaon and antikaon production channels
have been taken at the cooler synchrotron COSY in proton-proton scattering. In
the kaon--hyperon production an enhancement by one order of magnitude of the
Lambda/Sigma0 ratio has been observed at excess energies below Q=13 MeV
compared to data at higher excess energies (Q>300 MeV). New results obtained at
the COSY-11 facility explore the transition region between the regime of this
low-energy Sigma0 suppression and excess energies of 60 MeV. A comparison of
the energy dependence of the Lambda and Sigma0 total cross sections exhibits
distinct qualitative differences between both hyperon production channels.
Studies of kaon-antikaon production have been motivated especially by the
ongoing discussion about the nature of the scalar resonances f0(980) and
a0(980) coupling to the K anti-K channel. For the reaction pp->ppK+K- a first
total cross section value is reported at an excess energy of Q=17 MeV, i.e.
below the phi threshold. Calculations obtained within an OBE model indicate
that the energy dependence of the available total cross section data close to
threshold is rather difficult to reconcile with the assumption of a phase-space
behaviour modified predominantly by the proton-proton final state interaction.Comment: 10 pages, 4 figures, Presented at Meson 2002: 7th International
Workshop on Meson Production, Properties and Interaction, Cracow, Poland,
24-28 May 200
Family history of cancer and head and neck cancer survival
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137774/1/lary26524_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137774/2/lary26524.pd
Environmental engineering applications of electronic nose systems based on MOX gas sensors
Nowadays, the electronic nose (e-nose) has gained a huge amount of attention due to its
ability to detect and differentiate mixtures of various gases and odors using a limited number of sensors.
Its applications in the environmental fields include analysis of the parameters for environmental
control, process control, and confirming the efficiency of the odor-control systems. The e-nose has
been developed by mimicking the olfactory system of mammals. This paper investigates e-noses
and their sensors for the detection of environmental contaminants. Among different types of gas
chemical sensors, metal oxide semiconductor sensors (MOXs) can be used for the detection of volatile
compounds in air at ppm and sub-ppm levels. In this regard, the advantages and disadvantages
of MOX sensors and the solutions to solve the problems arising upon these sensors’ applications
are addressed, and the research works in the field of environmental contamination monitoring are
overviewed. These studies have revealed the suitability of e-noses for most of the reported applications,
especially when the tools were specifically developed for that application, e.g., in the facilities
of water and wastewater management systems. As a general rule, the literature review discusses the
aspects related to various applications as well as the development of effective solutions. However,
the main limitation in the expansion of the use of e-noses as an environmental monitoring tool is
their complexity and lack of specific standards, which can be corrected through appropriate data
processing methods applications
Hadronic interaction of eta and eta-prime mesons with nucleons
Due to their short life-time, flavour-neutral mesons cannot be utilized as
free secondary beams or targets, and therefore a study of their interaction
with nucleons is not possible via direct scattering experiments.
This interaction is, however, accessible via its influence on the energy
dependence - and on the phase space distributions of the cross sections for
reactions in which these mesons are produced.
In case of the p p --> p p eta reaction the experimentally determined
distributions of the differential cross sections close to the production
threshold cannot be described by taking into account the S-wave proton-proton
and proton-eta interaction only. Here we show that the angular distributions
determined at the COSY-11 facility reveal some evidence for P-wave admixture in
the proton-proton subsystem already at an excess energy as low as Q = 15.5 MeV.
We also present that one can estimate the relative strength of the
eta-nucleon and eta-prime-nucleon interactions by comparison of the eta and
eta-prime production yield.Comment: 4 pages, 3 figures, Talk given at 16th International Conference on
Particles and Nuclei (PANIC 02), Osaka, Japan, 30 Sep - 4 Oct 200
COSY-11: an experimental facility for studying meson production in free and quasi-free nucleon-nucleon collisions
The COSY-11 experimental setup is an internal facility installed at the
COoler SYnchrotron COSY in Juelich. It allows to investigate meson production
in free and quasi-free nucleon-nucleon collisions, eg. pp --> pp meson and pd
--> p_sp np meson reactions. Drift chambers and scintillators permit to measure
outgoing protons, separated in magnetic field of COSY-11 dipole. Neutrons are
registered in the neutron modular detector installed downstream the beam.
Recently, the experimental setup has been extended with spectator detector,
deuteron drift chamber and polarization monitoring system, and since then meson
production can be investigated also as a function of spin and isospin of
colliding nucleons.Comment: Presented at LEAP05: International conference on Low Energy
Antiproton Physics, Bonn - Juelich, Germany, May 16-22, 200
General thoughts to the Kaon pair production in the threshold region
Simple--minded thoughts about the cross sections for the reactions
pp-->ppK+K- and pp-->ppK0K0 are presented, which certainly do not account for
the complex coupled channel problem but rather provide some ideas into the
mutual reaction dynamics.Comment: Talk given at 9th International Workshop on Meson Production,
Properties and Interaction, Cracow, Poland, 9-13 June 2006. 3 pages, 2
figure
Isospin dependence of the eta' meson production in nucleon--nucleon collisions
According to the quark model, the masses of eta and eta' mesons should be
almost equal. However, the empirical values of these masses differ by more than
the factor of two. Similarly, though the almost the same quark-antiquark
content, the total cross section for the creation of these mesons close to the
kinematical thresholds in the pp --> ppX reaction differs significantly. Using
the COSY-11 detection setup we intend to determine whether this difference will
also be so significant in the case of the production of these mesons in the
proton-neutron scattering. Additionally, the comparison of the pp --> pp eta'
and pn --> pn eta' total cross sections will allow to learn about the
production of the eta' meson in the channels of isospin I = 0 and I = 1 and to
investigate aspects of the gluonium component of the eta' meson.Comment: Presented at LEAP05: International conference on Low Energy
Antiproton Physics, Bonn - Juelich, Germany, May 16-22, 200
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