10,998 research outputs found
Polyethylene imine-based receptor immobilization for label free bioassays
Polyethylene imine (PEI) based immobilization of antibodies is described and the concept is proved on the
label free assay of C-Reactive Protein (CRP). This novel immobilization method is composed of a hyperbranched
PEI layer which was deposited at a high pH (9.5) on the sensor surface. The free amino groups
of PEI were derivatized with neutravidin by Biotin N-hydroxysuccinimide ester and the biotinylated
anti-CRP antibody immobilized on this layer. Direct binding assay of recombinant CRP was successfully
performed in the low ÎŒg/ml concentrations using a label free optical waveguide biosensor
Characteristics of Feedback that Influence Student Confidence and Performance during Mathematical Modeling
This study focuses on characteristics of written feedback that influence studentsâ performance and confidence in addressing the mathematical complexity embedded in a Model-Eliciting Activity (MEA). MEAs are authentic mathematical modeling problems that facilitate studentsâ iterative development of solutions in a realistic context. We analyzed 132 first-year engineering studentsâ confidence levels and mathematical model scores on aMEA(pre and post feedback), along with teaching assistant feedback given to the students. The findings show several examples of affective and cognitive feedback that students reported that they used to revise their models. Studentsâ performance and confidence in developing mathematical models can be increased when they are in an environment where they iteratively develop models based on effective feedback
Scaling Relations and Exponents in the Growth of Rough Interfaces Through Random Media
The growth of a rough interface through a random media is modelled by a
continuous stochastic equation with a quenched noise. By use of the Novikov
theorem we can transform the dependence of the noise on the interface height
into an effective temporal correlation for different regimes of the evolution
of the interface. The exponents characterizing the roughness of the interface
can thus be computed by simple scaling arguments showing a good agreement with
recent experiments and numerical simulations.Comment: 4 pages, RevTex, twocolumns, two figures (upon request). To appear in
Europhysics Letter
Color-flavor locked strange matter
We analyze how the CFL states in dense matter work in the direction of
enhancing the parameter space for absolutely stable phases (strange matter). We
find that the "CFL strange matter" phase can be the true ground state of
hadronic matter for a much wider range of the parameters of the model (the gap
of the QCD Cooper pairs , the strange quark mass and the Bag
Constant ) than the state without any pairing, and derive a full equation of
state and an accurate analytic approximation to the lowest order in
and which may be directly used for applications. The effects of pairing
on the equation of state are found to be small (as previously expected) but not
negligible and may be relevant for astrophysics.Comment: 5 pages, 2 figure
âBasically... porn is everywhereâ: a rapid evidence assessment on the effects that access and exposure to pornography has on children and young people
This Rapid Evidence Assessment (REA) was commissioned by the Office of the Childrenâs Commissioner (OCC) as part of its Inquiry into Child Sexual Exploitation in Gangs and Groups (CSEGG). It was conducted by a consortium led by Middlesex University, to explore the effects that exposure and access to pornography have on children and young people. The CSEGG Inquiry was launched in October 2011 to better understand the scale, scope, extent and nature of child sexual exploitation in gangs and groups. An emergent issue was whether accessing and viewing pornography can have an impact on children and young peopleâs expectations and attitudes towards sexual activity and relationships. Despite limited recourse to previous evidence, professionals interviewed over the course of the CSEGG Inquiry raised concerns about the impact of pornography at 43 per cent of site visits and 48 per cent of evidence hearings (Berelowitz et al., 2012).
Professionals from many agencies reported particular concerns about the effects of pornography involving high levels of degradation, violence and humiliation, which they believe to be prevalent in material freely available online. Police case files that were reviewed cited instances of boys and young men referring to pornography during sexual assaults (Berelowitz et al., 2012). This REA was therefore commissioned to inform the CSEGG Inquiry Chair, Panel and Project Team, enabling them to add depth to their ultimate recommendations regarding child sexual exploitation in gangs and groups
The Negativity of the Overlap-Based Topological Charge Density Correlator in Pure-Glue QCD and the Non-Integrable Nature of its Contact Part
We calculate the lattice two-point function of topological charge density in
pure-glue QCD using the discretization of the operator based on the overlap
Dirac matrix. Utilizing data at three lattice spacings it is shown that the
continuum limit of the correlator complies with the requirement of
non-positivity at non-zero distances. For our choice of the overlap operator
and the Iwasaki gauge action we find that the size of the positive core is ~2a
(with a being the lattice spacing) sufficiently close to the continuum limit.
This result confirms that the overlap-based topological charge density is a
valid local operator over realistic backgrounds contributing to the QCD path
integral, and is important for the consistency of recent results indicating the
existence of a low-dimensional global brane-like topological structure in the
QCD vacuum. We also confirm the divergent short-distance behavior of the
correlator, and the non-integrable nature of the associated contact part.Comment: 13 pages, 5 figure
Nucleation of quark matter bubbles in neutron stars
The thermal nucleation of quark matter bubbles inside neutron stars is
examined for various temperatures which the star may realistically encounter
during its lifetime. It is found that for a bag constant less than a critical
value, a very large part of the star will be converted into the quark phase
within a fraction of a second. Depending on the equation of state for neutron
star matter and strange quark matter, all or some of the outer parts of the
star may subsequently be converted by a slower burning or a detonation.Comment: 13 pages, REVTeX, Phys.Rev.D (in press), IFA 93-32. 5 figures (not
included) available upon request from [email protected]
Overlap Valence on 2+1 Flavor Domain Wall Fermion Configurations with Deflation and Low-mode Substitution
The overlap fermion propagator is calculated on 2+1 flavor domain wall
fermion gauge configurations on 16^3 x 32, 24^3 x 64 and 32^3 x 64 lattices.
With HYP smearing and low eigenmode deflation, it is shown that the inversion
of the overlap operator can be expedited by ~ 20 times for the 16^3 x 32
lattice and ~ 80 times for the 32^3 x 64 lattice. Through the study of
hyperfine splitting, we found that the O(m^2a^2) error is small and these
dynamical fermion lattices can adequately accommodate quark mass up to the
charm quark. The low energy constant \Delta_{mix} which characterizes the
discretization error of the pion made up of a pair of sea and valence quarks in
this mixed action approach is calculated via the scalar correlator with
periodic and anti-periodic boundary conditions. It is found to be small which
shifts a 300 MeV pion mass by ~ 10 to 19 MeV on these sets of lattices. We have
studied the signal-to-noise issue of the noise source for the meson and baryon.
It is found that the many-to-all meson and baryon correlators with Z_3 grid
source and low eigenmode substitution is efficient in reducing errors for the
correlators of both mesons and baryons. With 64-point Z_3 grid source and
low-mode substitution, it can reduce the statistical errors of the light quark
(m_{\pi} ~ 200 - 300 MeV) meson and nucleon correlators by a factor of ~ 3-4 as
compared to the point source. The Z_3 grid source itself can reduce the errors
of the charmonium correlators by a factor of ~ 3.Comment: 30 pages, 18 figures, replaced with the version to be published in
PR
Treatment of benign prostatic hyperplasia by natural drugs
Benign prostatic hyperplasia (BPH) is one of the most common urinary diseases affecting men, generally after the age of 50. The prevalence of this multifactorial disease increases with age. With aging, the plasma level of testosterone decreases, as well as the testosterone/estrogen ratio, resulting in increased estrogen activity, which may facilitate the hyperplasia of the prostate cells. Another theory focuses on dihydrotestosterone (DHT) and the activity of the enzyme 5α-reductase, which converts testosterone to DHT. In older men, the activity of this enzyme increases, leading to a decreased testosterone/DHT ratio. DHT may promote prostate cell growth, resulting in hyperplasia. Some medicinal plants and their compounds act by modulating this enzyme, and have the above-mentioned targets. This review focuses on herbal drugs that are most widely used in the treatment of BPH, including pumpkin seed, willow herb, tomato, maritime pine bark, Pygeum africanum bark, rye pollen, saw palmetto fruit, and nettle root, highlighting the latest results of preclinical and clinical studies, as well as safety issues. In addition, the pharmaceutical care and other therapeutic options of BPH, including pharmacotherapy and surgical options, are discussed, summarizing and comparing the advantages and disadvantages of each therapy
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