3,854 research outputs found
Effective theories of scattering with an attractive inverse-square potential and the three-body problem
A distorted-wave version of the renormalisation group is applied to
scattering by an inverse-square potential and to three-body systems. In
attractive three-body systems, the short-distance wave function satisfies a
Schroedinger equation with an attractive inverse-square potential, as shown by
Efimov. The resulting oscillatory behaviour controls the renormalisation of the
three-body interactions, with the renormalisation-group flow tending to a limit
cycle as the cut-off is lowered. The approach used here leads to single-valued
potentials with discontinuities as the bound states are cut off. The
perturbations around the cycle start with a marginal term whose effect is
simply to change the phase of the short-distance oscillations, or the
self-adjoint extension of the singular Hamiltonian. The full power counting in
terms of the energy and two-body scattering length is constructed for
short-range three-body forces.Comment: 19 pages (RevTeX), 2 figure
Biomarker-assisted identification of sepsis-related acute liver impairment:A frequent and deadly condition in critically ill patients
NeutronC scattering near an Efimov state
The low-energy neutronC scattering in a neutron-neutron-core model is
studied with large scattering lengths near the conditions for the appearance of
an Efimov state. We show that the real part of the elastic wave phase-shift
() presents a zero, or a pole in , when the
system has an Efimov excited or virtual state. More precisely the pole scales
with the energy of the Efimov state (bound or virtual). We perform calculations
in the limit of large scattering lengths, disregarding the interaction range,
within a renormalized zero-range approach using subtracted equations. It is
also presented a brief discussion of these findings in the context of ultracold
atom physics with tunable scattering lengths
The ESO Nearby Abell Cluster Survey. XI. Segregation of cluster galaxies and subclustering
We study luminosity and morphology segregation of over 3000 cluster galaxies
in an ensemble cluster of 59 rich, nearby galaxy clusters observed in the ESO
Nearby Cluster Survey (ENACS). Within this sample we identify those galaxies
that are in substructures. We compare the distribution of projected
clustercentric distance, R, and 'normalized' relative line-of-sight velocity,
v, of several subsamples, using the 2D Kolmogorov-Smirnov test. We find
evidence of luminosity segregation only for the ellipticals outside
substructure and brighter than M_R = -22.0 +/- 0.1 (h0=100 km/s/Mpc). We
confirm the well-known segregation of early- and late-type galaxies. The early
and late spirals (Sa--Sb and Sbc--Ir respectively) outside substructure also
appear to have different (R,v)-distributions. In each morphological class, the
galaxies within substructure have different (R,v)-distributions from the
galaxies that are not in substructure. Among the samples of galaxies that are
not in substructure, at least 3 ensembles can and must be distinguished:
[E+S0], S_early, and [S_late+ELG]. The [E+S0] ensemble is most centrally
concentrated and has a fairly low velocity dispersion that hardly varies with
radius. The [S_late+ELG] ensemble is least concentrated and has the highest
velocity dispersion, which increases significantly towards the centre. The
(R,v)-distribution of S_early galaxies is intermediate between those of the two
other ensembles. Among the galaxies within substructure the S0 and [S_late+ELG]
galaxies have different (R,v) distributions. We discuss briefly the
implications of our results for processes of galaxy destruction and
transformation within clusters. [ABRIDGED]Comment: 18 pages. Accepted for publication in A
Reaction rates for Neutron Capture Reactions to C-, N- and O-isotopes to the neutron rich side of stability
The reaction rates of neutron capture reactions on light nuclei are important
for reliably simulating nucleosynthesis in a variety of stellar scenarios.
Neutron capture reaction rates on neutron-rich C-, N-, and O-isotopes are
calculated in the framework of a hybrid compound and direct capture model. The
results are tabulated and compared with the results of previous calculations as
well as with experimental results.Comment: 33 pages (uses revtex) and 9 postscript figures, accepted for
publication in Phys. Rev.
Selective inactivation of hypomethylating agents by SAMHD1 provides a rationale for therapeutic stratification in AML.
Hypomethylating agents decitabine and azacytidine are regarded as interchangeable in the treatment of acute myeloid leukemia (AML). However, their mechanisms of action remain incompletely understood, and predictive biomarkers for HMA efficacy are lacking. Here, we show that the bioactive metabolite decitabine triphosphate, but not azacytidine triphosphate, functions as activator and substrate of the triphosphohydrolase SAMHD1 and is subject to SAMHD1-mediated inactivation. Retrospective immunohistochemical analysis of bone marrow specimens from AML patients at diagnosis revealed that SAMHD1 expression in leukemic cells inversely correlates with clinical response to decitabine, but not to azacytidine. SAMHD1 ablation increases the antileukemic activity of decitabine in AML cell lines, primary leukemic blasts, and xenograft models. AML cells acquire resistance to decitabine partly by SAMHD1 up-regulation. Together, our data suggest that SAMHD1 is a biomarker for the stratified use of hypomethylating agents in AML patients and a potential target for the treatment of decitabine-resistant leukemia
Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research
Qualitative research investigating soccer practitioners’ perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: ‘importance of extra-time’, ‘rule changes’, ‘efficacy of extra-time hydro-nutritional provision’, ‘nutritional timing’,
‘future research directions’, ‘preparatory modulations’ and ‘recovery’. The majority of practitioners (63%) either agreed or strongly agreed that extra-time is an important period
for determining success in knockout football match-play. When asked if a fourth substitution
should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior
to extra-time was predominately considered important or very important. However; only
41% of practitioners felt that it was the most important time point for the use of nutritional
products. A similar number of practitioners account (50%) and do not (50%) account for the
potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority) were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses, acute injury risk, recovery modalities, training paradigms, injury epidemiology, and environmental considerations. This study presents novel insight into the practitioner perceptions of extra-time and provides information to readers about current
applied practices and potential future research opportunities
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Miscarriage and stillbirth following maternal Zika virus infection in nonhuman primates.
Zika virus (ZIKV) infection is associated with congenital defects and pregnancy loss. Here, we found that 26% of nonhuman primates infected with Asian/American ZIKV in early gestation experienced fetal demise later in pregnancy despite showing few clinical signs of infection. Pregnancy loss due to asymptomatic ZIKV infection may therefore be a common but under-recognized adverse outcome related to maternal ZIKV infection
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