On the usefulness of finding charts Or the runaway carbon stars of the Blanco & McCarthy field 37

We have been recently faced with the problem of cross--identifying stars recorded in historical catalogues with those extracted from recent fully digitized surveys (such as DENIS and 2MASS). Positions mentioned in the old catalogues are frequently of poor precision, but are generally accompanied by finding charts where the interesting objects are flagged. Those finding charts are sometimes our only link with the accumulated knowledge of past literature. While checking the identification of some of these objects in several catalogues, we had the surprise to discover a number of discrepancies in recent works.The main reason for these discrepancies was generally the blind application of the smallest difference in position as the criterion to identify sources from one historical catalogue to those in more recent surveys. In this paper we give examples of such misidentifications, and show how we were able to find and correct them.We present modern procedures to discover and solve cross--identification problems, such as loading digitized images of the sky through the Aladin service at CDS, and overlaying entries from historical catalogues and modern surveys. We conclude that the use of good finding charts still remains the ultimate (though time--consuming) tool to ascertain cross--identifications in difficult cases.Comment: 4 pages, 1 figure, accepted by A&

Protein multi-scale organization through graph partitioning and robustness analysis: Application to the myosin-myosin light chain interaction

Despite the recognized importance of the multi-scale spatio-temporal organization of proteins, most computational tools can only access a limited spectrum of time and spatial scales, thereby ignoring the effects on protein behavior of the intricate coupling between the different scales. Starting from a physico-chemical atomistic network of interactions that encodes the structure of the protein, we introduce a methodology based on multi-scale graph partitioning that can uncover partitions and levels of organization of proteins that span the whole range of scales, revealing biological features occurring at different levels of organization and tracking their effect across scales. Additionally, we introduce a measure of robustness to quantify the relevance of the partitions through the generation of biochemically-motivated surrogate random graph models. We apply the method to four distinct conformations of myosin tail interacting protein, a protein from the molecular motor of the malaria parasite, and study properties that have been experimentally addressed such as the closing mechanism, the presence of conserved clusters, and the identification through computational mutational analysis of key residues for binding.Comment: 13 pages, 7 Postscript figure

Identification and geographic distribution of genetic groups of Erysiphe necator in Chilean vineyards

The grapevine powdery mildew, caused by the biotrophic fungus Erysiphe necator, is one of the most important diseases of this crop in Chile. We converted existing single nucleotide polymorphisms in β-tubulin, rDNA intergenic spacer region 1 and eburicol 14-α-demethylase into three cleaved amplified polymorphic sequences (CAPS). These CAPS markers were used for the genetic characterization of Erysiphe necator isolates collected on clusters of Vitis vinifera cv. 'Cabernet Sauvignon' in 23 vineyards across Chile. Among the 105 Chilean isolates analyzed, 103 revealed to belong to genetic group B and 2 to genetic group A. These results correspond to the first report of the presence of genetic groups A and B of E. necator in Chile

Tempo and mode of early gene loss in endosymbiotic bacteria from insects

BACKGROUND: Understanding evolutionary processes that drive genome reduction requires determining the tempo (rate) and the mode (size and types of deletions) of gene losses. In this study, we analysed five endosymbiotic genome sequences of the gamma-proteobacteria (three different Buchnera aphidicola strains, Wigglesworthia glossinidia, Blochmannia floridanus) to test if gene loss could be driven by the selective importance of genes. We used a parsimony method to reconstruct a minimal ancestral genome of insect endosymbionts and quantified gene loss along the branches of the phylogenetic tree. To evaluate the selective or functional importance of genes, we used a parameter that measures the level of adaptive codon bias in E. coli (i.e. codon adaptive index, or CAI), and also estimates of evolutionary rates (Ka) between pairs of orthologs either in free-living bacteria or in pairs of symbionts. RESULTS: Our results demonstrate that genes lost in the early stages of symbiosis were on average less selectively constrained than genes conserved in any of the extant symbiotic strains studied. These results also extend to more recent events of gene losses (i.e. among Buchnera strains) that still tend to concentrate on genes with low adaptive bias in E. coli and high evolutionary rates both in free-living and in symbiotic lineages. In addition, we analyzed the physical organization of gene losses for early steps of symbiosis acquisition under the hypothesis of a common origin of different symbioses. In contrast with previous findings we show that gene losses mostly occurred through loss of rather small blocks and mostly in syntenic regions between at least one of the symbionts and present-day E. coli. CONCLUSION: At both ancient and recent stages of symbiosis evolution, gene loss was at least partially influenced by selection, highly conserved genes being retained more readily than lowly conserved genes: although losses might result from drift due to the bottlenecking of endosymbiontic populations, we demonstrated that purifying selection also acted by retaining genes of greater selective importance

Obstacles, levers and impacts of organic farming development in Camargue

We are presenting an analysis of the obstacles and levers for the development of organic cropping systems in Camargue, documented with a multicriteria analysis of scenarios of organic farming (OF) development. This communication is built using results from on-farm agronomic monitoring, stakeholders and farmers’ interviews and the use of models for integrated assessment of scenarios. At the farm level, the obstacles are related to identification of profitable cropping systems and rotations that include enough rice, conversion being therefore risky as impacting financial management and requiring a labour reorganisation. At the regional level, the constraints are related to the absence of advisory services for technical issues, and to the lack of coordination among the different stakeholders, to the low incentive of the public policies to convert, and to a relatively opaque organization of the supply chains. At the regional level, we analysed the consequences of two scenarios related to OF development on criteria such as the rice surface area, the quantity and quality of water, energy consumption or the employment generated. These results are expected to contribute to the definition of an action plan about OF development by the local stakeholders

Smoothened receptor signaling regulates the developmental shift of GABA polarity in rat somatosensory cortex.

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordSonic Hedgehog (Shh) and its patched-smoothened receptor complex control a variety of functions in the developing central nervous system such as neural cell proliferation and differentiation. Recently, Shh signaling components have been found to be expressed at the synaptic level in the postnatal brain, suggesting a potential role in the regulation of synaptic transmission. Using in utero electroporation of constitutively active and negative-phenotype forms of the Shh signal transducer smoothened (Smo), we studied the role of Smo signaling in the development and maturation of GABAergic transmission in the somatosensory cortex. Our results show that enhancing Smo activity during development accelerates the shift from depolarizing to hyperpolarizing GABA in dependence on functional expression of potassium-chloride cotransporter type 2 (KCC2). On the other hand, blocking Smo activity maintains GABA response in a depolarizing state in mature cortical neurons resulting in altered chloride homeostasis and increased seizure susceptibility. This study reveals an unexpected function of Smo signaling on the regulation of chloride homeostasis through the control of KCC2 cell surface stability and on the timing of the GABA inhibitory/excitatory shift in brain maturation

Diffusive limits on the Penrose tiling

In this paper random walks on the Penrose lattice are investigated. Heat kernel estimates and the invariance principle are shown

Improved Procedures for Purification of the Bandeiraea simplicifolia I Isolectins and Bandeiraea simplicifolia II Lectin by Affinity Chromatography

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66350/1/j.1432-1033.1980.tb07197.x.pd