A formally verified compiler back-end

This article describes the development and formal verification (proof of semantic preservation) of a compiler back-end from Cminor (a simple imperative intermediate language) to PowerPC assembly code, using the Coq proof assistant both for programming the compiler and for proving its correctness. Such a verified compiler is useful in the context of formal methods applied to the certification of critical software: the verification of the compiler guarantees that the safety properties proved on the source code hold for the executable compiled code as well

Clades of huge phages from across Earth's ecosystems

Bacteriophages typically have small genomes and depend on their bacterial hosts for replication. Here we sequenced DNA from diverse ecosystems and found hundreds of phage genomes with lengths of more than 200 kilobases (kb), including a genome of 735 kb, which is-to our knowledge-the largest phage genome to be described to date. Thirty-five genomes were manually curated to completion (circular and no gaps). Expanded genetic repertoires include diverse and previously undescribed CRISPR-Cas systems, transfer RNAs (tRNAs), tRNA synthetases, tRNA-modification enzymes, translation-initiation and elongation factors, and ribosomal proteins. The CRISPR-Cas systems of phages have the capacity to silence host transcription factors and translational genes, potentially as part of a larger interaction network that intercepts translation to redirect biosynthesis to phage-encoded functions. In addition, some phages may repurpose bacterial CRISPR-Cas systems to eliminate competing phages. We phylogenetically define the major clades of huge phages from human and other animal microbiomes, as well as from oceans, lakes, sediments, soils and the built environment. We conclude that the large gene inventories of huge phages reflect a conserved biological strategy, and that the phages are distributed across a broad bacterial host range and across Earth's ecosystems

Temporal progression in migratory status and sexual maturation in European silver eels during downstream migration

The onset of downstream migration of European eels is accompanied by a cessation of feeding and the start of sexual maturation which stresses the link between metabolism and sexual maturation, also suggesting an important role for exercise. Exercise has been tested with eels in swim tunnels and was found to stimulate the onset of sexual maturation. In this study, we have investigated the interplay between migration and maturation in the field during the downstream migration of female silver eels. Temporal changes in migratory status and sexual maturation among silver eels of the upstream Rhine River system over 3 months of the migration season (August, September and October) were determined in biometrical parameters, plasma 17β-estradiol and calcium levels, oocyte histology and gonadal fat levels. Furthermore, the ecological relevant parameters age as determined by otolithometry and health aspects indicated by haematocrit, haemoglobin and swim-bladder parasite load were measured. Silver eels were estimated to be 14 years old. A strong temporal progression in migratory stage was shown over the months of downstream migration. Catches probably represented a mix of reproductive migrants and feeding migrants of which the ratio increased over time. Furthermore, this study confirmed our hypothesis linking the migratory stage to early maturation as indicated by enlargement of the eyes, oocyte growth and fat deposition in the oocytes, exactly the same changes as found induced by exercise but not ruling out environmental influences. Migrants show extensive fat uptake by the oocytes, probably stimulated by the swimming exercise. In addition, at least 83% of the silver eels in this spawning run may have suffered from negative effects of swim-bladder parasites on their swimming performance

Syngas Production, Storage, Compression and Use in Gas Turbines

This chapter analyses syngas production through pyrolysis and gasification, its compression and its use in gas turbines. Syngas compression can be performed during or after thermal treatment processes. Important points are discussed related to syngas ignition, syngas explosion limit at high temperatures and high pressures and syngas combustion kinetics. Kinetic aspects influence ignition and final emissions which are obtained at the completion of the combustion process. The chapter is organized into four subsections, dealing with (1) innovative syngas production plants, (2) syngas compressors and compression process, (3) syngas ignition in both heterogeneous and homogeneous systems and (4) syngas combustion kinetics and experimental methods. Particular attention is given to ignition regions that affect the kinetics, namely systems that operate at temperatures higher than 1000 K can have strong ignition, whereas those operating at lower temperatures have weak ignition. Keywords: Pyrogas Pyrolysis Ignition Syngas Compression GasificationacceptedVersio

Gerenciamento de Enfermagem e administração das organizações do Terceiro Setor Gerencia de Enfermería y la administración de las organizaciones del Tercer Sector Managment in Nursing and the administration of Third Sector organizations

Neste artigo de revisão bibliográfica procurou-se verificar a evolução do terceiro setor e as relações entre gerenciamento em enfermagem nestas organizações. Constata-se um crescimento deste setor na área de saúde, trazendo a ampliação do mercado de trabalho para enfermeiros. Assim, considera-se que é preciso alertar os enfermeiros a estarem preparados para a gestão nestas organizações, buscando seu desenvolvimento na gestão hospitalar. O terceiro setor vem sendo valorizado como forma de promoção social nos segmentos de saúde, educação, assistência social e outros, reunindo indivíduos e instituições de forma participativa.<br>En este artículo de revisión bibliográfica se objectivó verificar la evolución del tercer sector y las relaciones entre gerenciamento en enfermería en estas organizacioneslas. Verificase un crescimiento de este sector en la area de salud, trayendo la ampliación en el mercado de trabajo para los enfermeros. Así, considerase que es necesario alertar a los enfermeros para supreparo para la gestión en estas organizaciones, buscando su desarrollo en la gestión hospitalaria. El tercer sector viene siendo valorado como forma de promoción social en la salud, educación, ayuda social y otros segmientos, juntando individuos y instituciones de una forma participativa.<br>In this article of bibliographical revision it was aimed at verifying the evolution of the third sector and the relations between nursing management in that organizations. It is observed a growing of this sector in health area, bringing a market anplification in the work of the nurse. Thus, it is considered the need for warning the nurses to be prepared for the management in these organizations, seeking for development in hospital management. Third sector is being valued as a form of social promotion in the health, education, social assistance and others segments, congregating individuals and institutions in a participative form