Cloning, Sequencing and Regulation of the Rhodobacter capsulatushemE Gene.

In Rhodobacter capsulatus, a purple nonsulfur bacterium, the tetrapyrrole pathway yields four end products: siroheme, vitamin B12, heme and bacteriochlorophyll. Growth of R. capsulatus under low oxygen tension increases carbon flow through the tetrapyrrole pathway up to 100 fold. The mechanism(s) for this regulation is currently unknown. One regulatory mechanism could be transcriptional control of one or more of the genes in the common portion of the tetrapyrrole pathway. The fifth gene in the pathway, hemE, has been cloned by complementation of an Escherichia coli hemE::miniTn10 mutant. Sequence data of hemE revealed the presence of an upstream palindrome that is homologous to consensus sequences reported upstream of seven other R. capsulatus bch, crt and puc genes. Under low oxygen tension, transcription of the palindrome-containing bch and crt genes is increased 2 to 4 fold and transcription of the puc gene is increased 40 fold. It has been speculated that the upstream motif represents a binding site for a regulatory protein involved in oxygen-mediated transcriptional control. Both dot blot analysis and chloramphenicol acetyltransferase assays were used to measure transcription of the R. capsulatus hemE gene under conditions of high and low oxygen tensions. The results indicated that transcription is not regulated by oxygen. If the palindrome upstream of the R. capsulatus hemE gene is a binding site for a regulatory protein, it is not a protein which responds to changes in oxygen tension

UN FORUM SERIES – business and human rights: no progress without protection for defenders

This post was contributed by Michael Ineichen, Programme Manager and Human Rights Council Advocacy Director at the International Service for Human Rights. The level of protection enjoyed by those defending rights has long been recognised as a vital indicator for the overall respect for human rights in a given context and country. Tracking progress on business respect for human rights therefore cannot ignore the evidence of increasing restrictions placed on human rights defenders and civil society in a number of countries around the world

Détection et analyse d'un problème de congestion réseau

Ce travail a pour but de mettre en place une solution qui permette de détecter et alerter des problèmes de congestion réseau. Il est divisé en deux étapes bien distinctes : La première étape est une démarche de recherche/analyse sur les méthodes de détection de la congestion réseau dans laquelle on trouve trois parties distinctes : 1. Introduction à la problématique de la congestion réseau 2. Détection de la congestion 3. Transmission / alerte de la congestion La deuxième étape (pratique) consiste au montage de trois schémas prototypes type afin de générer de la congestion et d’y appliquer la démarche de la première étape. Le trafic sera créé avec le générateur de trafic Iperf. La congestion sera détectée par l’équipement, signalée avec le protocole SNMP et analysée avec NetFlow. La mise en oeuvre et les différents outils utilisés pour la réalisation du montage seront décrits en détail dans ce rapport

Ability of the Oriental Fruit Moth Grapholita molesta (Lepidoptera: Tortricidae) to Detoxify Juglone, the Main Secondary Metabolite of the Non-host Plant Walnut

Many plant species produce toxic secondary metabolites that limit attacks by herbivorous insects, and may thereby constrain insect expansion to new hosts. Walnut is a host for the codling moth Cydia pomonella, which efficiently detoxifies the main walnut defensive compound juglone (5-hydroxy-1,4-naphthoquinone). The oriental fruit moth Grapholita molesta, which also belongs to the tribe Grapholitini, does not feed on walnut. We tested the performance of G. molesta, a highly invasive species, on artificial diets containing juglone at levels mimicking those found in walnut over the growing season. Juglone-fed G. molesta survived relatively well to adulthood, but larval and adult body weights were reduced, and larval developmental time was prolonged in a dose-dependent fashion. Chemical analysis of frass from larvae that had been fed a juglone-containing diet suggests that G. molesta reduces juglone to non-toxic 1,4,5-trihydroxynaphthalene in its gut. This unexpected tolerance of G. molesta to high levels of juglone may facilitate expansion of the host range beyond the current rosacean fruit trees used by this invasive pes

Sensitivity of GPS and GLONASS orbits with respect to resonant geopotential parameters

The Center for Orbit Determination in Europe (CODE) has been involved in the processing of combined GPS/GLONASS data during the International GLONASS Experiment (IGEX). The resulting precise orbits were analyzed using the program SORBDT. Introducing one satellite's positions as pseudo-observations, the program is capable of fitting orbital arcs through these positions using an orbit improvement procedure based on the numerical integration of the satellite's orbit and its partial derivative with respect to the orbit parameters. For this study, the program was enhanced to estimate selected parameters of the Earth's gravity field. The orbital periods of the GPS satellites are —in contrast to those of the GLONASS satellites - 2:1 commensurable (P Sid:P GPS) with the rotation period of the Earth. Therefore, resonance effects of the satellite motion with terms of the geopotential occur and they influence the estimation of these parameters. A sensitivity study of the GPS and GLONASS orbits with respect to the geopotential coefficients reveals that the correlations between different geopotential coefficients and the correlations of geopotential coefficients with other orbit parameters, in particular with solar radiation pressure parameters, are the crucial issues in this context. The estimation of the resonant geopotential terms is, in the case of GPS, hindered by correlations with the simultaneously estimated radiation pressure parameters. In the GLONASS case, arc lengths of several days allow the decorrelation of the two parameter types. The formal errors of the estimates based on the GLONASS orbits are a factor of 5 to 10 smaller for all resonant term

Wirkung verschiedener Insektizide und deren Kombination mit Fettsäuren und Rapsöl gegen die Salatblattlaus Nasonovia ribis-nigri

Fragestellung: Mit welchen Insektiziden und in welcher Kombination mit Beistoffen können die Salatblattläuse am effizientesten bekämpft werden? Wie nützlingsschonend sind die verschiedenen Insektizide und Insektizid/Beistoff-Kombinationen