Community Structure in Time-Dependent, Multiscale, and Multiplex Networks

Network science is an interdisciplinary endeavor, with methods and applications drawn from across the natural, social, and information sciences. A prominent problem in network science is the algorithmic detection of tightly-connected groups of nodes known as communities. We developed a generalized framework of network quality functions that allowed us to study the community structure of arbitrary multislice networks, which are combinations of individual networks coupled through links that connect each node in one network slice to itself in other slices. This framework allows one to study community structure in a very general setting encompassing networks that evolve over time, have multiple types of links (multiplexity), and have multiple scales.Comment: 31 pages, 3 figures, 1 table. Includes main text and supporting material. This is the accepted version of the manuscript (the definitive version appeared in Science), with typographical corrections included her

Influencia del sedentarismo en las desviaciones raquídeas de la población escolar de Léon

Nuestra investigación trata de evaluar los hábitos sedentarios, en los escolares de 10 y 14 años de una zona de León, y su influencia en las desviaciones raquídeas. Para la obtención de los hábitos nos basamos en el tets de Medoza, R. también se realizó una evaluación física de los niños para observar las desviaciones raquídeas. En el tratamiento de la información se utilizó el análisis de la varianza univariante y multivariante, además del análisis de componentes principales y análisis discriminante. Llegando a la conclusión, respecto al tiempo de televisión que el día de la semana que más tiempo dedican los niños a ver la televisión es discrimante de los escolares que tienen desviación raquídea

Measurement of \u3csup\u3e17\u3c/sup\u3eF + p reactions with ANASEN

Reactions involving radioactive nuclei play an important role in stellar explosions, but those reactions involving short-lived nuclei have only limited experimental information available due to currently limited beam intensities. Several facilities are aiming to provide greater access to these unstable isotopes at higher beam intensities, but more efficient and selective techniques and devices are needed to properly study these important reactions. The Array for Nuclear Astrophysics Studies with Exotic Nuclei (ANASEN), a charged particle detector designed by Louisiana State University (LSU) and Florida State University (FSU), was created for this purpose. ANASEN is used to study the reactions important in the αp- and rp- processes with proton-rich exotic nuclei, providing essentially complete solid angle coverage through an array of 40 silicon-strip detectors backed with CsI scintillators, covering an area of roughly 1300 cm2. ANASEN also includes an active gas target/detector in a position-sensitive annular gas proportional counter, which allows direct measurement of (α,p) reactions in inverse kinematics. The first in-beam measurements with a partial implementation of ANASEN were performed at the RESOLUT radioactive beam facility of FSU during the summer of 2011. They included stable beam experiments and measurements of the 17F(p,p) 17F and 17F(p,α)14O reactions which are important to understanding the structure of 18Ne and the 14O(α,p)17F reaction rate. The performance of ANASEN and initial results from the 17F studies will be presented. © Published under licence by IOP Publishing Ltd

Clustering in non-self-conjugate nuclei \u3csup\u3e10\u3c/sup\u3eBe and \u3csup\u3e18\u3c/sup\u3eO

Clustering phenomena in 10Be and 18O were studied by means of resonance elastic scattering of α-particles on 6He and 14C. Excitation functions for α+6He and α+14C were measured and detailed R-matrix analyses of the excitation functions was performed. We compare the experimental results with the predictions of modern theoretical approaches and discuss properties of cluster rotational bands

Measurement of F 17 (d,n) Ne 18 and the impact on the F 17 (p,γ) Ne 18 reaction rate for astrophysics

Background: The F17(p,γ)Ne18 reaction is part of the astrophysical hot CNO cycles that are important in astrophysical environments like novas. Its thermal reaction rate is low owing to the relatively high energy of the resonances and therefore is dominated by direct, nonresonant capture in stellar environments at temperatures below 0.4 GK. Purpose: An experimental method is established to extract the proton strength to bound and unbound states in experiments with radioactive ion beams and to determine the parameters of direct and resonant capture in the F17(p,γ)Ne18 reaction. Method: The F17(d,n)Ne18 reaction is measured in inverse kinematics using a beam of the short-lived isotope F17 and a compact setup of neutron, proton, γ-ray, and heavy-ion detectors called resoneut. Results: The spectroscopic factors for the lowest l=0 proton resonances at Ec.m.=0.60 and 1.17 MeV are determined, yielding results consistent within 1.4σ of previous proton elastic-scattering measurements. The asymptotic normalization coefficients of the bound 21+ and 22+ states in Ne18 are determined and the resulting direct-capture reaction rates are extracted. Conclusions: The direct-capture component of the F17(p,γ)Ne18 reaction is determined for the first time from experimental data on Ne18

Experimental Investigation of the Ne 19 (p,γ)20Na Reaction Rate and Implications for Breakout from the Hot CNO Cycle

The Ne19(p,γ)Na20 reaction is the second step of a reaction chain which breaks out from the hot CNO cycle, following the O15(α,γ)Ne19 reaction at the onset of x-ray burst events. We investigate the spectrum of the lowest proton-unbound states in Na20 in an effort to resolve contradictions in spin-parity assignments and extract reliable information about the thermal reaction rate. The proton-transfer reaction Ne19(d,n)Na20 is measured with a beam of the radioactive isotope Ne19 at an energy around the Coulomb barrier and in inverse kinematics. We observe three proton resonances with the Ne19 ground state, at 0.44, 0.66, and 0.82 MeV c.m. energies, which are assigned 3+, 1+, and (0+), respectively. In addition, we identify two resonances with the first excited state in Ne19, one at 0.20 MeV and one, tentatively, at 0.54 MeV. These observations allow us for the first time to experimentally quantify the astrophysical reaction rate on an excited nuclear state. Our experiment shows an efficient path for thermal proton capture in Ne19(p,γ)Na20, which proceeds through ground state and excited-state capture in almost equal parts and eliminates the possibility for this reaction to create a bottleneck in the breakout from the hot CNO cycle

Determining the \u3csup\u3e14\u3c/sup\u3eO(α,p)\u3csup\u3e17\u3c/sup\u3eF astrophysical rate from Measurements at TwinSol

The 14O(α,p)17F reaction is an important trigger reaction to the α-p process in X-ray bursts. The most stringent experimental constraints on its astrophysical rate come from measurements of the time-inverse reaction, 17F(p,α)14O. Previous studies of this inverse reaction have sufficiently characterized the high-energy dependence of the cross section but there are still significant uncertainties at lower energies. A new measurement of the 17F(p,α)14O cross section is underway at the Twin Solenoid (TwinSol) facility at the University of Notre Dame using an in-flight secondary 17F beam. The initial results are promising but improvements are needed to complete the measurement. The initial data and plans for an improved measurement are presented in this manuscript

Recent Nuclear Astrophysics Measurements using the TwinSol Separator

Many astrophysical events, such as novae and X-ray bursts, are powered by reactions with radioactive nuclei. Studying the properties of these nuclei in the laboratory can therefore further our understanding of these astrophysical explosions. The TwinSol separator at the University of Notre Dame has recently been used to produce intense (∼106 pps) beams of 17F. In this article, some of the first measurements with these beams are discussed