Early Identification of Violent Criminal Gang Members

Gang violence is a major problem in the United States accounting for a large fraction of homicides and other violent crime. In this paper, we study the problem of early identification of violent gang members. Our approach relies on modified centrality measures that take into account additional data of the individuals in the social network of co-arrestees which together with other arrest metadata provide a rich set of features for a classification algorithm. We show our approach obtains high precision and recall (0.89 and 0.78 respectively) in the case where the entire network is known and out-performs current approaches used by law-enforcement to the problem in the case where the network is discovered overtime by virtue of new arrests - mimicking real-world law-enforcement operations. Operational issues are also discussed as we are preparing to leverage this method in an operational environment.Comment: SIGKDD 201

Configurational temperature control for atomic and molecular systems

A new configurational temperature thermostat suitable for molecules with holonomic constraints is derived. This thermostat has a simple set of motion equations, can generate the canonical ensemble in both position and momentum space, acts homogeneously through the spatial coordinates, and does not intrinsically violate the constraints. Our new configurational thermostat is closely related to the kinetic temperature Nosé-Hoover thermostat with feedback coupled to the position variables via a term proportional to the net molecular force. We validate the thermostat by comparing equilibrium static and dynamic quantities for a fluid of n-decane molecules under configurational and kinetic temperature control. Practical aspects concerning the implementation of the new thermostat in a molecular dynamics code and the potential applications are discussed

Discovery of optical pulsations in V2116 Ophiuchi/GX 1+4

We report the detection of pulsations with $\sim 124$ s period in V2116 Oph, the optical counterpart of the low-mass X-ray binary GX 1+4. The pulsations are sinusoidal with modulation amplitude of up to 4% in blue light and were observed in ten different observing sessions during 1996 April-August using a CCD photometer at the 1.6-m and 0.6-m telescopes of Laborat\'orio Nacional de Astrof\'{\i}sica, in Brazil. The pulsations were also observed with the $UBVRI$ fast photometer. With only one exception the observed optical periods are consistent with those observed by the BATSE instrument on board the Compton Gamma Ray Observatory at the same epoch. There is a definite correlation between the observability of pulsations and the optical brightness of the system: V2116~Oph had $R$ magnitude in the range $15.3-15.5$ when the pulsed signal was detected, and $R = 16.0-17.7$ when no pulsations were present. The discovery makes GX 1+4 only the third of $\sim 35$ accretion-powered X-ray pulsars to be firmly detected as a pulsating source in the optical. The presence of flickering and pulsations in V2116 Oph adds strong evidence for an accretion disk scenario in this system. The absolute magnitude of the pulsed component on 1996 May 27 is estimated to be $M_V \sim -1.5$. The implied dimensions for the emitting region are 1.1 R_{\sun}, 3.2 R_{\sun}, and 7.0 R_{\sun}, for black-body spectral distributions with $T = 10^5$ K, $2 \times 10^4$ K, and $1 \times 10^4$ K, respectively.Comment: 9 pages, 3 figures in PostScript, latex, accepted for publication on the Astrophysical Journal Letter

Alterações oftalmológicas na gravidez

Pregnancy is needed for the perpetuation of the human species, and it leads to physiological adaptations of the various maternal organs and systems. The eye, although a closed space, also undergoes some modifications, most of which are relatively innocuous, but they may occasionally become pathological. For women, pregnancy is a susceptibility period; however, for many obstetricians, their knowledge of the ocular changes that occur during pregnancy tends to be limited. For this reason, this is a important area of study as is necessary the development of guidelines to approach those changes. Of equal importance are the knowledge of the possible therapies for ophthalmological problems in this period and the evaluation of the mode of delivery in particular conditions. For this article, an extensive review of the literature was performed, and a summary of the findings is presented.A gravidez é necessária à perpetuação da espécie humana, levando a adaptações fisiológicas dos diversos órgãos e sistemas maternos. O olho, apesar de uma cavidade fechada, sofre também algumas modificações, a maioria relativamente inócuas, que pontualmente poderão se tornar patológicas. A gravidez assume-se como um período particular de suscetibilidade para a mulher; no entanto, muitos obstetras têm conhecimento limitado sobre as alterações oftalmológicas na gravidez. Por conseguinte, impõe-se o seu estudo, bem como a elaboração de diretrizes para lidar com essas mudanças. De igual importância são o conhecimento da eventual terapêutica para problemas oftalmológicos neste período e a avaliação do tipo do parto em condições particulares. Desta forma, foi efetuada uma revisão bibliográfica extensa e apresentada uma síntese do tema.info:eu-repo/semantics/publishedVersio

Optical and Near-Infrared UBVRIJHK Photometry for the RR Lyrae stars in the Nearby Globular Cluster M4 (NGC 6121)

We present optical and near-infrared UBVRIJHK photometry of stars in the Galactic globular cluster M4 (NGC 6121) based upon a large corpus of observations obtained mainly from public astronomical archives. We concentrate on the RR Lyrae variable stars in the cluster, and make a particular effort to accurately reidentify the previously discovered variables. We have also discovered two new probable RR Lyrae variables in the M4 field: one of them by its position on the sky and its photometric properties is a probable member of the cluster, and the second is a probable background (bulge?) object. We provide accurate equatorial coordinates for all 47 stars identified as RR Lyraes, new photometric measurements for 46 of them, and new period estimates for 45. We have also derived accurate positions and mean photometry for 34 more stars previously identified as variable stars of other types, and for an additional five non-RR Lyrae variable stars identified for the first time here. We present optical and near-infrared color-magnitude diagrams for the cluster and show the locations of the variable stars in them. We present the Bailey (period-amplitude) diagrams and the period-frequency histogram for the RR Lyrae stars in M4 and compare them to the corresponding diagrams for M5 (NGC 5904). We conclude that the RR Lyrae populations in the two clusters are quite similar in all the relevant properties that we have considered. The mean periods, pulsation-mode ratios, and Bailey diagrams of these two clusters show support for the recently proposed "Oosterhoff-neutral" classification.Comment: 33 pages, 16 figures, 7 table

Vibrational energy transfer in N(2D)+N2 collisions: a quasiclassical trajectory study

Rate coefficients for the N(2D)+N2 collisions were calculated employing quasiclassical trajectories and the first available set of potential energy surfaces for such excited nitrogen interactions. The details of the vibrational energy transfer are discussed, such as the contributions from reactive and non-reactive trajectories as well as the contribution of each electronic symmetry. The calculated state-to-state and state-to-all rate coefficients show that deactivation is far more probable than excitation, and multi-quanta deactivation play an important role

Glueball Regge trajectories from gauge/string duality and the Pomeron

The spectrum of light baryons and mesons has been reproduced recently by Brodsky and Teramond from a holographic dual to QCD inspired in the AdS/CFT correspondence. They associate fluctuations about the AdS geometry with four dimensional angular momenta of the dual QCD states. We use a similar approach to estimate masses of glueball states with different spins and their excitations. We consider Dirichlet and Neumann boundary conditions and find approximate linear Regge trajectories for these glueballs. In particular the Neumann case is consistent with the Pomeron trajectory.Comment: In this revised version we made some additional remarks on the text. We also included 2 more references. The glueball spectrum and Regge trajectories are unchanged. 10 pages, 2 eps figure

Efeito do zinco, boro, molibdênio e calagem na produção de soja-perene (Glycine javanica L.) cultivada em solos de cerrado, em condições de casa-de-vegetação.

Este trabalho foi conduzido em casa-de-vegetacao, com amostras de solos do municipio de Sete Lagoas, Estado de Minas Gerais. Foram coletadas amostras de solo: Latossolo Vermelho-Amarelo e Latossolo Vermelho-Escuro, fase cerrado, de 0 a 20 cm de profundidade. Este trabalho teve como objetivo estudar a resposta da soja-perene (Glycine javanica L.) variedade "Tinaroo", a aplicacao de zinco, boro molibdenio e calagem bem como observar a influencia da calagem na disponibilidade de alguns nutrientes. As plantas foram analisadas quanto aos testes totais de nitrogenio, fosforo, potassio, calcio, magnesio, zinco, boro e molibdenio