de Broglie-Proca and Bopp-Podolsky massive photon gases in cosmology

We investigate the influence of massive photons on the evolution of the expanding universe. Two particular models for generalized electrodynamics are considered, namely de Broglie-Proca and Bopp-Podolsky electrodynamics. We obtain the equation of state (EOS) $P=P(\varepsilon)$ for each case using dispersion relations derived from both theories. The EOS are inputted into the Friedmann equations of a homogeneous and isotropic space-time to determine the cosmic scale factor $a(t)$. It is shown that the photon non-null mass does not significantly alter the result $a\propto t^{1/2}$ valid for a massless photon gas; this is true either in de Broglie-Proca's case (where the photon mass $m$ is extremely small) or in Bopp-Podolsky theory (for which $m$ is extremely large).Comment: 8 pages, 2 figures; v2 matches the published versio

Light-induced protein clustering for optogenetic interference and protein interaction analysis in drosophila S2 cells

Drosophila Schneider 2 (S2) cells are a simple and powerful system commonly used in cell biology because they are well suited for high resolution microscopy and RNAi-mediated depletion. However, understanding dynamic processes, such as cell division, also requires methodology to interfere with protein function with high spatiotemporal control. In this research study, we report the adaptation of an optogenetic tool to Drosophila S2 cells. Light-activated reversible inhibition by assembled trap (LARIAT) relies on the rapid light-dependent heterodimerization between cryptochrome 2 (CRY2) and cryptochrome-interacting bHLH 1 (CIB1) to form large protein clusters. An anti-green fluorescent protein (GFP) nanobody fused with CRY2 allows this method to quickly trap any GFP-tagged protein in these light-induced protein clusters. We evaluated clustering kinetics in response to light for different LARIAT modules, and showed the ability of GFP-LARIAT to inactivate the mitotic protein Mps1 and to disrupt the membrane localization of the polarity regulator Lethal Giant Larvae (Lgl). Moreover, we validated light-induced co-clustering assays to assess protein-protein interactions in S2 cells. In conclusion, GFP-based LARIAT is a versatile tool to answer different biological questions, since it enables probing of dynamic processes and protein-protein interactions with high spatiotemporal resolution in Drosophila S2 cells.This research was funded by the National Funds through Fundação para a Ciência e a Tecnologia (FCT) under the project (PTDC/BEX-BCM/0432/2014). E.M. holds an FCT Investigator position. M.O. is supported by a fellowship from the GABBA PhD program from the University of Porto, PD/BD/105746/2014

Melhoramento genético do arroz de sequeiro no Nordeste do Brasil.

Disponível via Word Wide Web http://www.cpatsa.embrapa.br

Descritores morfo agronômicos e fenológicos de cultivares comerciais de arroz (Oryza sativa L.) de terras altas.

O presente trabalho teve por objetivo apresentar os descritores morfo agronômicos, fenológicos e culinários de oito novas cultivares de arroz de terras altas recomendadas nos anos de 2000 a 2003.bitstream/CNPAF/22920/1/doc_162.pd

Tempo de prateleira de cultivares de arroz de terras altas.

Este trabalho teve por objetivo verificar o comportamento culinário, após um período de repouso pós-colheita em condições de armazenamento, de algumas cultivares e linhagens promissoras de arroz de terras altas.bitstream/CNPAF/23593/1/comt_98.pd

Seleção de linhagens do arroz de terras altas na região Meio-Norte do Brasil.

Visando a selecao de linhagens com elevado potencial genetico de rendimento e superior qualidade de graos em relacao as cultivares atualmente em uso, no ano agricola 1996/97, foram realizados cinco ensaios de arroz de terras altas, atraves da Embrapa Meio-Norte, nos Estados do Piaui e Maranhao. Avaliaram-se quinze linhagens e cinco cultivares (Carajas, Caiapo, Progresso, Maravilha e Canastra) em Ensaios Comparativos Avancados, em Urucui, no Estado do Piaui, e em Sao Domingos do Azeitao, Sambaiba, Riachao e Tasso Fragoso, no Maranhao, mediante o delineamento de blocos casualizados. Com rendimento de graos superior a 1900 kg/ha, mesmo em condicoes climaticas adversas, destacaram-se as linhagens CNA 8305, CNA 8346, IAC 1464, CNA 8172 e CNA 8070. Esta ultima linhagem, com a denominacao de Primavera, e a cultivar Canastra, por apresentarem alto rendimento de graos e boas qualidades industriais e culinarias, foram indicadas para o ecossistema de terras altas do Meio-Norte.bitstream/item/35789/1/Bol21.pd