Playing Darwin. Part B. 20 years of domestication in Drosophila subobscura

Adaptation to a new environment (as well as its underlying mechanisms) is one of the most important topics in Evolutionary Biology. Understanding the adaptive process of natural populations to captivity is essential not only in general evolutionary studies but also in conservation programmes. Since 1990, the Group of Experimental Evolution (CBA/FCUL) has been performing long-term, real-time evolutionary studies, with the characterization of laboratory adaptation in populations of Drosophila subobscura founded in different times and from different locations. Initially, these experiments involved phenotypic assays and more recently were expanded to studies at the molecular level (microsatellite and chromosomal polymorphisms) and with different population sizes. Throughout these two decades, a clear pattern of evolutionary convergence to long-established laboratory populations has been consistently observed in several life-history traits. However, contingencies across foundations were also found during the adaptive process. In characters with complex evolutionary trajectories, the data suggested that the comparative method lacked predictive capacity relative to real-time evolutionary trajectories (experimental evolution). Microsatellite analysis revealed general similarity in gene diversity and allele number between studied populations, as well as an unclear association between genetic variability and evolutionary potential. Nevertheless, ongoing studies in all foundations are being carried out to further test this hypothesis. A comparison between recently introduced and long-term populations (founded from the same natural location) has shown higher degree of chromosomal polymorphism in recent ones. Finally, our findings suggest higher heterogeneity between small-sized populations, as well as a slower evolutionary rate in characters close to fitness (such as fecundity and mating behaviour). This comprehensive study is aimed at better understanding the processes and patterns underlying adaptation to captivity, as well as its genetic basis

Lâminas de irrigação no primeiro ciclo dos genótipos Prata-anã e Princesa nas condições do Norte de Minas.

O objetivo deste trabalho foi avaliar a resposta produtiva dos genótipos Prata-Anã e Princesa a diferentes lâminas de irrigação. O trabalho foi conduzido no norte de Minas Gerais. Utilizaram-se mudas plantadas nos espaçamento de 2,0 x 2,5 metros. Os tratamentos consistiram de cinco lâminas de irrigação (25%, 50%, 75%, 100% e 125% da evapotranspiração de referência - ETo) e dois genótipos de bananeira (Prata-Anã e Princesa). A lâmina de irrigação foi determinada com base na evaporação do Tanque Classe A. Utilizou-se o delineamento em blocos casualizados com esquema de parcela subdividida com três blocos. A produtividade aumentou linearmente com o aumento da lâmina de irrigação. O genótipo Prata-Anã possui menor ciclo vegetativo, o genótipo Princesa apresenta menor ciclo produtivo e maior produtividade de fruto e não há diferença entre os genótipos para o ciclo total. O ciclo produtivo estimado diminui 11,11% com o aumento da lâmina de irrigação de 25% da ETo para 125% da ETo. O ciclo total estimado diminui 8,82% com o aumento da lâmina de irrigação de 25% da ETo para 125% da ETo. A produtividade de fruto estimada aumenta 35,20% com o aumento da lâmina de irrigação de 25% da ETo para 125% da ETo

The Geometry of Mass Outflows and Fueling Flows in the Seyfert 2 Galaxy Mrk 3

We present a study of the resolved emission-line regions and an inner dust/gas disk in the Seyfert 2 galaxy Mrk 3, based on Hubble Space Telescope observations. We show that the extended narrow-line region (ENLR), spanning ~4 kpc, is defined by the intersection of the ionizing bicone of radiation from the AGN and the inner disk, which is not coplanar with the large-scale stellar disk. This intersection leads to different position and opening angles of the ENLR compared to the narrow-line region (NLR). A number of emission-line arcs in the ENLR appear to be continuations of dust lanes in the disk, supporting this geometry. The NLR, which consists of outflowing emission-line knots spanning the central ~650 pc, is in the shape of a backwards S. This shape may arise from rotation of the gas, or it may trace the original fueling flow close to the nucleus that was ionized after the AGN turned on.Comment: 22 page, 7 figures, accepted for publication in the Astronomical Journa

Economic value for the trait tick count in Brangus cattle.

Profitability of a beef cattle system may be significantly reduced by the effects of tick (Rhipicephalus (Boophilus) microplus).IMAS. Pôster 45209

The periodic Anderson model from the atomic limit and FeSi

The exact Green's functions of the periodic Anderson model for $U\to \infty$ are formally expressed within the cumulant expansion in terms of an effective cumulant. Here we resort to a calculation in which this quantity is approximated by the value it takes for the exactly soluble atomic limit of the same model. In the Kondo region a spectral density is obtained that shows near the Fermi surface a structure with the properties of the Kondo peak. Approximate expressions are obtained for the static conductivity $$ and magnetic susceptibility $\chi (T)$ of the PAM, and they are employed to fit the experimental values of FeSi, a compound that behaves like a Kondo insulator with both quantities vanishing rapidly for $T\to 0$. Assuming that the system is in the intermediate valence region, it was possible to find good agreement between theory and experiment for these two properties by employing the same set of parameters. It is shown that in the present model the hybridization is responsible for the relaxation mechanism of the conduction electrons.Comment: 26 pages and 8 figure

from theory to practice

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Global persistence exponent of the two-dimensional Blume-Capel model

The global persistence exponent $\theta_g$ is calculated for the two-dimensional Blume-Capel model following a quench to the critical point from both disordered states and such with small initial magnetizations. Estimates are obtained for the nonequilibrium critical dynamics on the critical line and at the tricritical point. Ising-like universality is observed along the critical line and a different value $\theta_g =1.080(4)$ is found at the tricritical point.Comment: 7 pages with 3 figure