Gravitational wave recoils in non-axisymmetric Robinson-Trautman spacetimes

We examine the gravitational wave recoil waves and the associated net kick velocities in non-axisymmetric Robinson-Trautman spacetimes. We use characteristic initial data for the dynamics corresponding to non-head-on collisions of black holes. We make a parameter study of the kick distributions, corresponding to an extended range of the incidence angle $\rho_0$ in the initial data. For the range of $\rho_0$ examined ($3^{\circ} \leq \rho_0 \leq 110^{\circ}$) the kick distributions as a function of the symmetric mass parameter $\eta$ satisfy a law obtained from an empirical modification of the Fitchett law, with a parameter $C$ that accounts for the non-zero net gravitational momentum wave fluxes for the equal mass case. The law fits accurately the kick distributions for the range of $\rho_0$ examined, with a rms normalized error of the order of $5 \%$. For the equal mass case the nonzero net gravitational wave momentum flux increases as $\rho_0$ increases, up to $\rho_0 \simeq 55^{\circ}$ beyond which it decreases. The maximum net kick velocity is about $190 {\rm km/s}$ for for the boost parameter considered. For $\rho_0 \geq 50^{\circ}$ the distribution is a monotonous function of $\eta$. The angular patterns of the gravitational waves emitted are examined. Our analysis includes the two polarization modes present in wave zone curvature.Comment: 10 pages, 5 figures. arXiv admin note: substantial text overlap with arXiv:1403.4581, arXiv:1202.1271, arXiv:1111.122

The low dimensional dynamical system approach in General Relativity: an example

In this paper we explore one of the most important features of the Galerkin method, which is to achieve high accuracy with a relatively modest computational effort, in the dynamics of Robinson-Trautman spacetimes.Comment: 7 pages, 5 figure

Estudo da diversidade genética e estrutura populacional de castanheira-do-brasil (Bertholletia excelsa) em florestas nativas do Mato Grosso.

Em espécies vegetais, estudos da diversidade e estrutura genética, estrutura genética espacial (EGE), sistema de reprodução e dispersão de pólen em populações naturais são fundamentais para a conservação genética, visto que permitem determinar quais populações são mais aptas para a conservação in situe para a coleta de sementes para a conservação ex situ. Para tanto, amostras de DNA foram coletadas de castanheiras adultas de quatro populações localizadas no estado de Mato Grosso - Alta Floresta, Cotriguaçu, Juína e Itaúba. Para as análises com marcadores moleculares foram utilizados sete loci microssatélites. Para o estudo de diversidade genética foi utilizada a medida de diferenciação genética de Hedrick (2005). Em uma dessas populações (Itaúba), todos os indivíduos adultos foram avaliados e as sementes foram coletadas para a formação das progênies. A estrutura genética espacial, o sistema de reprodução e o fluxo de pólen foram estudados na população Itaúba e os resultados preliminares revelam estruturação significativa entre adultos até 163 m, sugerindo que plantas localizadas dentro desta distância são parentes entre si. Foi observado também cruzamentos entre indivíduos aparentados e a maior parte da diversidade genética está distribuída entre populações

Hybrid photonic-bandgap accelerating cavities

In a recent investigation, we studied two-dimensional point-defected photonic bandgap cavities composed of dielectric rods arranged according to various representative periodic and aperiodic lattices, with special emphasis on possible applications to particle acceleration (along the longitudinal axis). In this paper, we present a new study aimed at highlighting the possible advantages of using hybrid structures based on the above dielectric configurations, but featuring metallic rods in the outermost regions, for the design of extremely-high quality factor, bandgap-based, accelerating resonators. In this framework, we consider diverse configurations, with different (periodic and aperiodic) lattice geometries, sizes, and dielectric/metal fractions. Moreover, we also explore possible improvements attainable via the use of superconducting plates to confine the electromagnetic field in the longitudinal direction. Results from our comparative studies, based on numerical full-wave simulations backed by experimental validations (at room and cryogenic temperatures) in the microwave region, identify the candidate parametric configurations capable of yielding the highest quality factor.Comment: 13 pages, 5 figures, 3 tables. One figure and one reference added; minor changes in the tex

A Phase II Trial of Fixed-Dose Rate Gemcitabine plus Capecitabine in Metastatic/Advanced Biliary Tract Cancer Patients

Background: This phase II trial was conducted to determine the activity and safety of the combination of fixed-dose rate (FDR) gemcitabine and capecitabine in metastatic biliary tract cancer (BTC) patients. Methods: Patients with unresectable BTC who had pathologically confirmed adenocarcinoma, no prior chemotherapy, Eastern Cooperative Oncology Group (ECOG) performance status 641 and measurable disease were enrolled. Treatment consisted of FDR gemcitabine at 800 mg/m 2 on days 1 and 8 every 21 days with capecitabine administered orally b.i.d. in equal doses (650 mg/m 2 b.i.d.) for 14 days (28 doses). Results: Between May 2005 and February 2009, 30 patients were enrolled. The median age was 67 years (45-76) and there were 14 males. Thirty patients were evaluable for response and toxicity. A total of 221 cycles were administered (median 7, range 2-16). One patient achieved complete response and 7 patients achieved partial response, giving an overall response rate of 26.7% in the intention-to-treat population. Twelve patients (40.0%) had stable disease. The median progression-free survival was 6.33 months. The median overall survival was 10.8 months. Grade 3/4 neutropenia and thrombocytopenia were noted in 13 and 7% of the patients, respectively. Grade 2/3 nonhematologic toxicities were asthenia (54% of patients), diarrhea (17%), stomatitis (23%) and hand-foot syndrome (7%). There was no treatment-related death. The drugs taken were skipped at least once in 45% of the patients and the dose was reduced in 26% of them. Conclusions: The combination of FDR gemcitabine and capecitabine in this 3-week cycle is safe and seems to have a good activity in advanced biliary cancer

Caracterização do Sistema Extrativista e Coeficientes Técnicos de Produção Para o Sistema Extrativo da Castanheira-do-Brasil (Bertholletia Excelsa H.b.k) Praticado Pelos Índios WAiWAi Em Roraima.

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Primary tumor sidedness and benefit from FOLFOXIRI plus bevacizumab as initial therapy for metastatic colorectal cancer. Retrospective analysis of the TRIBE trial by GONO

Right-sided metastatic colorectal cancer (mCRC) patients have poor prognosis and achieve limited benefit from first-line doublets plus a targeted agent. In this unplanned analysis of the TRIBE study, we investigated the prognostic and predictive impact of primary tumor sidedness in mCRC patients and the differential impact of the intensification of the chemotherapy in subgroups defined according to both primary tumor sidedness and RAS and BRAF mutational status