Solving Four Dimensional Field Theories with the Dirichlet Fivebrane

The realization of ${\cal N}=2$ four dimensional super Yang-Mills theories in terms of a single Dirichlet fivebrane in type IIB string theory is considered. A classical brane computation reproduces the full quantum low energy effective action. This result has a simple explanation in terms of mirror symmetry.Comment: Final version to appear in Phys. Rev.

Cementing proteins provide extra mechanical stabilization to viral cages

The study of virus shell stability is key not only for gaining insights into viral biological cycles but also for using viral capsids in materials science. The strength of viral particles depends profoundly on their structural changes occurring during maturation, whose final step often requires the specific binding of ‘decoration’ proteins (such as gpD in bacteriophage lambda) to the viral shell. Here we characterize the mechanical stability of gpD-free and gpD-decorated bacteriophage lambda capsids. The incorporation of gpD into the lambda shell imparts a major mechanical reinforcement that resists punctual deformations. We further interrogate lambda particle stability with molecular fatigue experiments that resemble the sub-lethal Brownian collisions of virus shells with macromolecules in crowded environments. Decorated particles are especially robust against collisions of a few kBT (where kB is the Boltzmann’s constant and T is the temperature ~300 K), which approximate those anticipated from molecular insults in the environmentWe acknowledge the MINECO of Spain (PIB2010US-00233, FIS3011-29493, Consolider CSD2010-00024, CAMprojectNo.S3009/MAT-1467), and the US National Science Foundation (MCB-1158107) for their financial support of this researc

(1,0) superconformal models in six dimensions

We construct six-dimensional (1,0) superconformal models with non-abelian gauge couplings for multiple tensor multiplets. A crucial ingredient in the construction is the introduction of three-form gauge potentials which communicate degrees of freedom between the tensor multiplets and the Yang-Mills multiplet, but do not introduce additional degrees of freedom. Generically these models provide only equations of motions. For a subclass also a Lagrangian formulation exists, however it appears to exhibit indefinite metrics in the kinetic sector. We discuss several examples and analyze the excitation spectra in their supersymmetric vacua. In general, the models are perturbatively defined only in the spontaneously broken phase with the vev of the tensor multiplet scalars serving as the inverse coupling constants of the Yang-Mills multiplet. We briefly discuss the inclusion of hypermultiplets which complete the field content to that of superconformal (2,0) theories.Comment: 30 pages, v2: Note, some comments and references adde

Sample size for family evaluation in potato breeding programs.

Clonal families from a broad genetic base population in the Potato Breeding Program at the Universidade Federal de Lavras (UFLA), Brazil, were used in this trials. Twenty-five families were assessed in a 5 x 5 triple lattice design. Each plot consisted of 30 clones distributed in three rows of ten plants. Tuber yield per plant, percentage of large tubers, mean weight of large tubers, mean medium-sized tuber weight and tuber specific gravity were measured. Three hundred experiments were simulated varying the family sizes from three to 90 clones. The coefficients of experimental variation (CVe), the coefficients of genetic variation (CVg), heritabilities for family mean and the CVg/CVe ratio were estimated. Genetic parameters were stabilized with family sizes as small as six clones, depending on the trait. This indicates that the families can be adequately represented by a small sample of clones. Using the maximum curvature method it is possible to conclude that approximately 30 clones would be sufficient to represent each family, even for traits with the highest CVe. The genetic variance within family was greater than the genetic variance among families for all traits, indicating a favorable potential for within family selection. The correlation coefficients of the family means with the 5%, 10%, 15% and 20% best clones from each family, considering the five traits assessed, were always high, meaning that within the best families generally are the best clones

Higher Derivative BLG: Lagrangian and Supersymmetry Transformations

Working to lowest non-trivial order in fermions, we consider the four-derivative order corrected Lagrangian and supersymmetry transformations of the Euclidean Bagger-Lambert-Gustavsson theory. By demonstrating supersymmetric invariance of the Lagrangian we determine all numerical coefficients in the system. In addition, the supersymmetry algebra is shown to close on the scalar and gauge fields. We also comment on the extension to Lorentzian and other non-Euclidean $\mathcal{N}=8$ 3-algebra theories.Comment: 23 page

Results from South Africa's 2016 report card on physical activity for children and youth

Background: We present results of the 2016 Healthy Active Kids South Africa (HAKSA) Report Card on the current status of physical activity (PA) and nutrition in South African youth. The context in which we interpret the findings is that participation in PA is a fundamental human right, along with the right to "attainment of the highest standard of health." Methods: The HAKSA 2016 Writing Group was comprised of 33 authorities in physical education, exercise science, nutrition, public health, and journalism. The search strategy was based on peer-reviewed manuscripts, dissertations, and 'gray' literature. The core PA indicators are Overall Physical Activity Level; Organized Sport Participation; Active and Outdoor Play; Active Transportation; Sedentary Behaviors; Family and Peer Influences; School; Community and the Built Environment; and National Government Policy, Strategies, and Investment. In addition, we reported on Physical Fitness and Motor Proficiency separately. We also reported on nutrition indicators including Overweight and Under-nutrition along with certain key behaviors such as Fruit and Vegetable Intake, and policies and programs including School Nutrition Programs and Tuck Shops. Data were extracted and grades assigned after consensus was reached. Grades were assigned to each indicator ranging from an A, succeeding with a large majority of children and youth (81% to 100%); B, succeeding with well over half of children and youth (61% to 80%); C, succeeding with about half of children and youth (41% to 60%); D, succeeding with less than half but some children and youth (21% to 40%); and F, succeeding with very few children and youth (0% to 20%); INC is inconclusive. Results: Overall PA levels received a C grade, as we are succeeding with more than 50% of children meeting recommendations. Organized Sports Participation also received a C, and Government Policies remain promising, receiving a B. Screen time and sedentary behavior were a major concern. Under-and over-weight were highlighted and, as overweight is on the rise, received a D grade. Conclusion: In particular, issues of food security, obesogenic environments, and access to activity-supportive environments should guide social mobilization downstream and policy upstream. There is an urgent need for practice-based evidence based on evaluation of existing, scaled up interventions.Scopu

Qualitative evaluation of a physical activity-based chronic disease prevention program in a low-income, rural South African setting

Introduction: Chronic diseases, an increasing global concern, are prevalent in the low-income communities of South Africa, where rural health systems bear the double burden of infectious and chronic diseases. The Discovery Healthy Lifestyle Programme (DHLP) is a physical activity-based chronic disease prevention program that has been implemented in a low-income, rural setting in South Africa. The DHLP consists of both school- and primary healthcare clinic-based interventions for learners (Healthnutz) and adults (Live it Up), facilitated by teachers, nurses and community volunteers. The aim of this evaluation was to qualitatively assess the process by which the DHLP was implemented, identifying enabling factors and barriers. Methods: Data were collected in target communities at schools and clinics from semi-structured focus groups of program leaders and members, teachers and community members (n=45), situational analyses of the school physical activity environment, informal community observations and informal interviews with program coordinators. Results: The target communities faced socioeconomic and health inequalities and remained under-resourced and under-served. In spite of these and other challenges, the DHLP was well received by community members and stakeholders. It was valued by respondents for its health and psychosocial outcomes, evidenced by increased knowledge and awareness of the importance of physical activity and healthy lifestyles, and positively altered perceptions of physical activity. Program implementers believed the Live it Up component was growing, and this suggested the sustainability of the program. There were, however, some concerns about the fidelity of the Healthnutz intervention, due to timetabling difficulties. Despite this, teachers were positive about the program and its value for their learners, staff and school. The community characteristics of being under-resourced and underserved appeared to positively influence DHLP implementation. Local government involvement in the DHLP resulted in greater ownership of the program, which enabled successful implementation. Conclusions: This study presents a unique opportunity to assess the implementation and sustainability requirements of programs in environments of limited resources, considerable burden of infectious and chronic diseases and extensive socioeconomic challenges. The findings suggest that through enhancement of knowledge, transfer of appropriate skills and the provision of an enabling environment, participation in physical activity can be effectively promoted in a low-income, rural setting. Physical activity interventions that promote the participation and empowerment of rural communities can be feasible and accessible, thereby assisting in addressing the growing burden of chronic diseases in low-income

Resonant transmission of normal electrons through Andreev states in ferromagnets

Giant oscillations of the conductance of a superconductor - ferromagnet - superconductor Andreev interferometer are predicted. The effect is due to the resonant transmission of normal electrons through Andreev levels when the voltage $V$ applied to the ferromagnet is close to $2h_0/e$ ($h_0$ is the spin-dependant part of the electron energy). The effect of bias voltage and phase difference between the superconductors on the current and the differential conductance is presented. These efects allow a direct spectroscopy of Andreev levels in the ferromagnet.Comment: 4 pages, 4 figure

Cultivares de soja 2007/2008 regiões Norte e Nordeste.

Épocas de semeadura; População de plantas - densidade de semeadura; Grupos de maturação; Evolução da soja nos Estados do MA, PI, PA, e RR; Cultivares de soja convencionais; Cultivares de soja transgênicas; Cultivares de soja indicadas para as regições norte e nordeste.bitstream/item/57904/1/Documentos-284.pd

alpha-nucleus potentials for the neutron-deficient p nuclei

alpha-nucleus potentials are one important ingredient for the understanding of the nucleosynthesis of heavy neutron-deficient p nuclei in the astrophysical gamma-process where these p nuclei are produced by a series of (gamma,n), (gamma,p), and (gamma,alpha) reactions. I present an improved alpha-nucleus potential at the astrophysically relevant sub-Coulomb energies which is derived from the analysis of alpha decay data and from a previously established systematic behavior of double-folding potentials.Comment: 6 pages, 3 figures, accepted for publication in Phys. Rev.