655 research outputs found
A pilot study: Digestion inhibiting effect of silver birch in moose
A pilot study: Digestion inhibiting effect of silver birch in moos
P04-16. Orally exposed uninfected individuals have systemic anti-HIV response correlating with partner's viral load
The Cambridge Prognostic Groups for improved prediction of disease mortality at diagnosis in primary non-metastatic prostate cancer: a validation study.
Purpose: To validate a new 5-tier prognostic classification system to better discriminate cancer specific mortality in men diagnosed with primary non-metastatic prostate cancer.
Patients and Methods: We applied a recently described 5 strata model (Cambridge Prognostic Groups-CPG) in 2 international cohorts and tested prognostic performance against the current standard 3 strata classification of low, intermediate or high-risk disease. Diagnostic clinico-pathological data of men from Prostate Cancer Data Base Sweden (PCBaSe) and the Singapore Health Study were used. The main outcome measure was prostate cancer mortality (PCM) stratified by age group and treatment
modality.
Results: The PCBaSe cohort included 72,337 men, of whom 7,162 died of prostate cancer. The CPG model successfully classified men with different risks of PCM with competing risk-regression confirming significant intergroup distinction (p<0.0001). The CPGs were significantly better at stratified prediction of PCM compared to the current 3-tier system (C-Index 0.81 vs. 0.77, p<0.0001). This superiority was maintained for every age group division (p<0.0001). Also in the ethnically different Singapore cohort of
2,550 men with 142 prostate cancer deaths, the CPG model outperformed the 3 strata categories (C-Index 0.79 vs. 0.76, p<0.0001). The model also retained superior prognostic discrimination in treatment sub-groups - Radical prostatectomy (n=20,586): C-Index 0.77 vs. 074, radiotherapy (n=11,872): C-Index 0.73 vs. 0.68, and conservative management (n=14,950): C-Index 0.74 vs. 0.73. The CPG groups that sub-divided the old intermediate (CPG2 vs. CPG3) and high-risk categories (CPG4 vs.CPG5) significantly discriminated PCM outcomes after radical therapy or conservative management (p<0.0001).
Conclusion: This validation study of nearly 75,000 men, confirms that the CPG 5-tiered prognostic model has superior discrimination in predicting prostate cancer death over the 3-tier model across different age and treatment groups. Crucially, it identifies distinct sub-groups of men within the old intermediate-risk and high-risk criteria who have very different prognostic outcomes We therefore propose adoption of the CPG model as a simple to use but more accurate prognostic stratification tool to help guide management for men with newly diagnosed prostate cancer
Nucleon structure from mixed action calculations using 2+1 flavors of asqtad sea and domain wall valence fermions
We present high statistics results for the structure of the nucleon from a
mixed-action calculation using 2+1 flavors of asqtad sea and domain wall
valence fermions. We perform extrapolations of our data based on different
chiral effective field theory schemes and compare our results with available
information from phenomenology. We discuss vector and axial form factors of the
nucleon, moments of generalized parton distributions, including moments of
forward parton distributions, and implications for the decomposition of the
nucleon spin.Comment: 68 pages, 47 figures. Main revision points: improved discussion of
chiral fits and systematic uncertainties, several minor refinements. Accepted
for publication in Phys.Rev.
Brane universes tested by supernovae
We discuss observational constrains coming from supernovae Ia
\cite{Perlmutter99} imposed on the behaviour of the Randall-Sundrum models. In
the case of dust matter on the brane, the difference between the best-fit
general relativistic model with a -term \cite{Perlmutter99} and the
best-fit brane models becomes detectable for redshifts . It is
interesting that brane models predict brighter galaxies for such redshifts
which is in agreement with the measurement of the supernova
\cite{Riess01} and with the New Data from the High Z Supernovae Search Team
\cite{schmit02}. We also demonstrate that the fit to supernovae data can also
be obtained, if we admit the "super-negative" dark energy
on the brane, where the dark energy in a way mimics the influence of the
cosmological constant. It also appears that the dark energy enlarges the age of
the universe which is demanded in cosmology. Finally, we propose to check for
dark radiation and brane tension by the application of the angular diameter of
galaxies minimum value test.Comment: 4 pages, 5 figures, REVTEX4, amended versio
Tight-binding g-Factor Calculations of CdSe Nanostructures
The Lande g-factors for CdSe quantum dots and rods are investigated within
the framework of the semiempirical tight-binding method. We describe methods
for treating both the n-doped and neutral nanostructures, and then apply these
to a selection of nanocrystals of variable size and shape, focusing on
approximately spherical dots and rods of differing aspect ratio. For the
negatively charged n-doped systems, we observe that the g-factors for
near-spherical CdSe dots are approximately independent of size, but show strong
shape dependence as one axis of the quantum dot is extended to form rod-like
structures. In particular, there is a discontinuity in the magnitude of
g-factor and a transition from anisotropic to isotropic g-factor tensor at
aspect ratio ~1.3. For the neutral systems, we analyze the electron g-factor of
both the conduction and valence band electrons. We find that the behavior of
the electron g-factor in the neutral nanocrystals is generally similar to that
in the n-doped case, showing the same strong shape dependence and discontinuity
in magnitude and anisotropy. In smaller systems the g-factor value is dependent
on the details of the surface model. Comparison with recent measurements of
g-factors for CdSe nanocrystals suggests that the shape dependent transition
may be responsible for the observations of anomalous numbers of g-factors at
certain nanocrystal sizes.Comment: 15 pages, 6 figures. Fixed typos to match published versio
Nucleon Generalized Parton Distributions from Full Lattice QCD
We present a comprehensive study of the lowest moments of nucleon generalized
parton distributions in N_f=2+1 lattice QCD using domain wall valence quarks
and improved staggered sea quarks. Our investigation includes helicity
dependent and independent generalized parton distributions for pion masses as
low as 350 MeV and volumes as large as (3.5 fm)^3, for a lattice spacing of
0.124 fm. We use perturbative renormalization at one-loop level with an
improvement based on the non-perturbative renormalization factor for the axial
vector current, and only connected diagrams are included in the isosinglet
channel.Comment: 40 pages, 49 figures; Revised chiral extrapolations in sections A-K,
main conclusions unchange
CAG repeat length in the androgen receptor gene is related to age at diagnosis of prostate cancer and response to endocrine therapy, but not to prostate cancer risk
The length of the polymorphic CAG repeat in the N-terminal of the androgen receptor (AR) gene is inversely correlated with the transactivation function of the AR. Some studies have indicated that short CAG repeats are related to higher risk of prostate cancer. We performed a case–control study to investigate relations between CAG repeat length and prostate cancer risk, tumour grade, tumour stage, age at diagnosis and response to endocrine therapy. The study included 190 AR alleles from prostate cancer patients and 186 AR alleles from female control subjects. All were whites from southern Sweden. The frequency distribution of CAG repeat length was strikingly similar for cases and controls, and no significant correlation between CAG repeat length and prostate cancer risk was detected. However, for men with non-hereditary prostate cancer (n = 160), shorter CAG repeats correlated with younger age at diagnosis (P = 0.03). There were also trends toward associations between short CAG repeats and high grade (P = 0.07) and high stage (P = 0.07) disease. Furthermore, we found that patients with long CAG repeats responded better to endocrine therapy, even after adjusting for pretreatment level of prostate-specific antigen and tumour grade and stage (P = 0.05). We conclude that short CAG repeats in the AR gene correlate with young age at diagnosis of prostate cancer, but not with higher risk of the disease. Selection of patients with early onset prostate cancer in case–control studies could therefore lead to an over-estimation of the risk of prostate cancer for men with short CAG repeats. An association between long CAG repeats and good response to endocrine therapy was also found, but the mechanism and clinical relevance are unclear. © 1999 Cancer Research Campaig
Finite volume corrections to the electromagnetic current of the nucleon
We compute corrections to both the isovector anomalous magnetic moment and
the isovector electromagnetic current of the nucleon to in the
framework of covariant two-flavor Baryon Chiral Perturbation Theory. We then
apply these corrections to lattice data for the anomalous magnetic moment from
the LHPC, RBC & UKQCD and QCDSF collaborations
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