The N N -> NN pi+ Reaction near Threshold in a Chiral Power Counting Approach

Power-counting arguments are used to organize the interactions contributing to the N N -> d pi, p n pi reactions near threshold. We estimate the contributions from the three formally leading mechanisms: the Weinberg-Tomozawa (WT) term, the impulse term, and the $\Delta$-excitation mechanism. Sub-leading but potentially large mechanisms, including $S$-wave pion-rescattering, the Galilean correction to the WT term, and short-ranged contributions are also examined. The WT term is shown to be numerically the largest, and the other contributions are found to approximately cancel. Similarly to the reaction p p -> p p pi0, the computed cross sections are considerably smaller than the data. We discuss possible origins of this discrepancy.Comment: 31 pages, 17 figure

Aspectos fotomorfogenéticos de plantas jovens de jatobá (Hymenaea courbaril L.).

Organizado por Patricia Póvoa de Mattos, Celso Garcia Auer, Rejane Stumpf Sberze, Katia Regina Pichelli e Paulo César Botosso

Uso de dardos anestésicos para a captura de veados campeiros (Ozotoceros bezoarticus) no Pantanal.

Existem poucos relatos sobre a captura de cervídeos na América do Sul. Até hoje, a captura do veado campeiro (Ozotoceros bezoarticus) em vida livre foi feita principalmente com uso de redes, seguida de contenção química. Neste trabalho, avaliou-se a viabilidade de captura de indivíduos da espécie utilizando dardos anestésicos, lançados à distância. Essa técnica, também conhecida como ?darting?, nunca havia sido reportada para captura de O. bezoarticus na natureza, pois se acreditava que os animais morreriam em fuga, devido ao estresse relacionado ao tiro. A fim de evitar tal possibilidade, a técnica apresentada incluiu uma fase longa de abordagem dos animais. No geral, a trajetória descrita durante a aproximação teve formato de espiral em torno dos alvos e, via de regra, o atirador adotou ângulos oblíquos para aproximar-se, até alcançar a condição de tiro (<20 m). Entre os anos de 2005 e 2006, foram realizadas 23 capturas de veados campeiros com uso de Zolazepan + Tiletamina (1:1), na dosagem de 10 mg/kg ou Telazol + Xilazina (2:1), na dosagem de 3 a 4,5 mg/kg e 1,5 a 2,25 mg/kg, respectivamente. Os dardos foram lançados com de pistola de gás comprimido ?dartgun? ou zarabatana. Todos os animais capturados recuperam-se após a captura e nenhuma injúria visível foi registrada. Apenas uma mortalidade foi observada durante o estudo. O método mostrou-se eficaz e pode substituir com vantagens o anterior, uma vez que a equipe necessária é menor e o risco de mortalidade mais baixo. A alternativa apresentada é recomendada para futuras capturas de O. bezoarticus. A experiência do atirador é um fator limitante ao método.bitstream/CPAP/55937/1/BP71.pdfFormato eletrônic

Experiments on computer assisted optimization of the escherichia coli fermentation process using Optferm

We used the software Optferm to model and optimize the bioprocess of escherichia coli fermentation, simulating the conditions of a fed-batch bioreactor. The results, obtained by employing different AI approaches, provided useful orientation for nutrient feed strategies for increased productivity. In conclusion, we believe in silico tools can perform a rapid and valid optimization of bioprocesses avoiding expensive experiments

LaF3 core/shell nanoparticles for subcutaneous heating and thermal sensing in the second biological-window

We report on Ytterbium and Neodymium codoped LaF3 core/shell nanoparticles capable of simultaneous heating and thermal sensing under single beam infrared laser excitation. Efficient light-to-heat conversion is produced at the Neodymium highly doped shell due to non-radiative de-excitations. Thermal sensing is provided by the temperature dependent Nd3+ → Yb3+ energy transfer processes taking place at the core/shell interface. The potential application of these core/shell multifunctional nanoparticles for controlled photothermal subcutaneous treatments is also demonstratedThis work was supported by the Spanish Ministerio de Economıa y Competitividad (MAT2013-47395-C4-1-R), by Brazilian Agencies: FINEP (Financiadora de Estudos e Projetos) through the Grant Nos. INFRAPESQ-11 and INFRAPESQ-12; CNPq (Conselho Nacional de Desenvolvimento Cientıfico e Tecnologico) Grants INCT NANO(BIO)SIMES and Project Universal No. 483238/2013-9; CAPES (Coordenadoria de Aperfeiçoamento de Pessoal de Ensino Superior) by means of the Project PVE No. A077/2013. Erving C. Ximendes is supported by a Ph.D. scholarship from CNPq and currently by the PVE A077/2013 Project by means of a Ph.D. sandwich program developed at the Universidad Autonoma de Madrid, Spain. Prof. Dr. Daniel Jaque is the PVE (Pesquisador Visitante Especial) of the Project No. A077/2013. Dr. K. U. Kumar is a post-doctoral fellow of this Project. Dr. Ueslen Rocha is supported by a Post Doctoral Fellowship grant PDE/CAPES at the Universidad Autonoma de Madrid-Spain through the Project No. 2108-14-

Relativistic O(q4)O(q^4) two-pion exchange nucleon-nucleon potential: configuration space

We have recently performed a relativistic $O(q^4)$ chiral expansion of the two-pion exchange $NN$ potential, and here we explore its configuration space content. Interactions are determined by three families of diagrams, two of which involve just $g_A$ and $f_{\pi}$, whereas the third one depends on empirical coefficients fixed by subthreshold $\pi N$ data. In this sense, the calculation has no adjusted parameters and gives rise to predictions, which are tested against phenomenological potentials. The dynamical structure of the eight leading non-relativistic components of the interaction is investigated and, in most cases, found to be clearly dominated by a well defined class of diagrams. In particular, the central isovector and spin-orbit, spin-spin, and tensor isoscalar terms are almost completely fixed by just $g_A$ and $f_{\pi}$. The convergence of the chiral series in powers of the ratio (pion mass/nucleon mass) is studied as a function of the internucleon distance and, for $r>$ 1 fm, found to be adequate for most components of the potential. An important exception is the dominant central isoscalar term, where the convergence is evident only for $r>$ 2.5 fm. Finally, we compare the spatial behavior of the functions that enter the relativistic and heavy baryon formulations of the interaction and find that, in the region of physical interest, they differ by about 5%.Comment: 27 pages, 33 figure

Chiral Perturbation Theory in Few-Nucleon Systems

The low-energy effective theory of nuclear physics based on chiral symmetry is reviewed. Topics discussed include the nucleon-nucleon force, few-body potentials, isospin violation, pion-deuteron scattering, proton-neutron radiative capture, pion photoproduction on the deuteron, and pion production in proton-proton collisions.Comment: 15 pages, 2 figures, Latex, aipproc.sty and epsfig, invited talk at the 6th Conference on the Intersections of Particle and Nuclear Physics, Big Sky, May 199