[Transport des pylônes dédiés à la bataille de la Somme, allégorie de la victoire, vers l'avenue des Champs-Elysées, autour du 13 juillet 1919] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 54838

PRPF31 alternative splicing and expression in human retina

PURPOSE: To provide a mechanistic link between mutations in PRPF31, and essential and ubiquitously expressed gene, and retinitis pigmentosa, a disorder restricted to the eye. METHODS: We investigated the existence of retina-specific PRPF31 isoforms and the expression of this gene in human retina and other tissues, as well as in cultured human cell lines. PRPF31 transcripts were examined by RT-PCR, quantitative PCR, cloning and sequencing. RESULTS: Database searching revealed the presence of a retina-specific PRPF31 isoform in mouse. However, this isoform could not be experimentally identified in transcripts from human retina or from a human whole eye. Nevertheless, four different PRPF31 isoforms, that were common to all analyzed tissues and cell lines, were isolated. Three of these harbored the full-length PRPF31 coding sequence, whereas the fourth was very short and probably non-coding. The amount of PRPF31 mRNA was previously found to be lower in patients with mutations in this gene than in healthy individuals, making it likely that retinal cells are more sensitive to variation in PRPF31 expression. However, quantitative PCR experiments revealed that PRPF31 mRNA levels in human retina were comparable to those detected in other tissues. CONCLUSIONS: Our results show that the retina-restricted phenotype caused by PRPF31 mutations cannot be explained by the presence of tissue-specific isoforms, or by differential expression of PRPF31 in the retina. As a consequence, the etiology of PRPF31-associated retinitis pigmentosa likely relies on other, probably more subtle molecular mechanisms.

Localization in sucrose gradients of the pyrophosphate-dependent proton transport of maize root membranes.

A maize (Zea mays L. cv LG 11) root homogenate was prepared and centrifuged to sediment the mitochondria. The pellet (6 KP) and the supernatant (6 KS) were collected and fractionated on linear sucrose density gradients. Marker enzymes were used to study the distribution of the different cell membranes in the gradients. The distribution of the ATP- and pyrophosphate-dependent proton pumping activities was similar after 3 hours of centrifugation of the 6 KS or the 6 KP fraction. The pumps were clearly separated from the mitochondrial marker cytochrome c oxidase and the plasmalemma marker UDP-glucose-sterolglucosyl-transferase. The pyrophosphate-dependent proton pump might be associated with the tonoplast, as the ATP-dependent pump, despite the lack of a specific marker for this membrane. However, under all the conditions tested, the two pumps overlapped the Golgi markers latent UDPase and glucan synthase I and the ER marker NADH-cytochrome c reductase. It is therefore not possible to exclude the presence of proton pumping activities on the Golgi or the ER of maize root cells. The two pumps (but especially the pyrophosphate-dependent one) were more active (or more abundant) in the tip than in the basal part of maize roots, indicating that these activities might be important in growth processes.

Acoustic transport of charge and spins in GaAs-based heterostructures

Report for the scientific sojourn carried out at the Paul Drude Institut für Festkörperelektronik of the Stanford University, USA, from 2010 to 2012. The objective of this project is the transport and control of electronic charge and spin along GaAs-based semiconductor heterostructures. The electronic transport has been achieved by taking advantage of the piezolectric field induced by surface acoustic waves in non-centrosymmetric materials like GaAs. This piezolectric field separates photogenerated electrons and holes at different positions along the acoustic wave, where they acummulate and are transported at the same velocity as the wave. Two different kinds of structures have been studied: quantum wells grown along the (110) direction, both intrinsic and n-doped, as well as GaAs nanowires. The analysis of the charge acoustic transport was performed by micro-photoluminescence, whereas the detection of the spin transport was done either by analyzing the polarization state of the emitted photoluminescence or by Kerr reflectometry. Our results in GaAs quantum wells show that charge and spin transport is clearly observed at the non-doped structures,obtaining spin lifetimes of the order of several nanoseconds, whereas no acoutically induced spin transport was detected for the n-doped quantum wells. In the GaAs nanowires, we were able of transporting successfully both electrons and holes along the nanowire axis, but no conservation of the spin polarization has been observed until now. The photoluminescence emitted by these structures after acoustic transport, however, shows anti-bunching characteristics, making this system a very good candidate for its use as single photon emitters.

Nanomotors: new strategies of (bio)sensing based on motion

Nanomotors are nanoscale devices capable of converting energy into movement and forces. Among them, self-propelled nanomotors offer considerable promise for developing new and novel bioanalytical and biosensing strategies based on the direct isolation of target biomolecules or changes in their movement in the presence of target analytes. The mainachievements of this project consists on the development of receptor-functionalized nanomotors that offer direct and rapid target detection, isolation and transport from raw biological samples without preparatory and washing steps. For example, microtube engines functionalized with aptamer, antibody, lectin and enzymes receptors were used for the direct isolation of analytes of biomedical interest, including proteins and whole cells, among others. A target protein was also isolated from a complex sample by using an antigen-functionalized microengine navigating into the reservoirs of a lab-on-a-chip device. The new nanomotorbased target biomarkers detection strategy not only offers highly sensitive, rapid, simple and low cost alternative for the isolation and transport of target molecules, but also represents a new dimension of analytical information based on motion. The recognition events can be easily visualized by optical microscope (without any sophisticated analytical instrument) to reveal the target presence and concentration. The use of artificial nanomachines has shown not only to be useful for (bio)recognition and (bio)transport but also for detection of environmental contamination and remediation. In this context, micromotors modified with superhydrophobic layer demonstrated that effectively interacted, captured, transported and removed oil droplets from oil contaminated samples. Finally, a unique micromotor-based strategy for water-quality testing, that mimics live-fish water-quality testing, based on changes in the propulsion behavior of artificial biocatalytic microswimmers in the presence of aquatic pollutants was also developed. The attractive features of the new micromachine-based target isolation and signal transduction protocols developed in this project offer numerous potential applications in biomedical diagnostics, environmental monitoring, and forensic analysis.

The Geographical Scope of Industrial Location Determinants: An Alternative Approach

This paper considers the estimation of the geographical scope of industrial location determinants. While previous studies impose strong assumptions on the weighting scheme of the spatial neighbour matrix, we propose a exible parametrisation that allows for di fferent (distance-based) de finitions of neighbourhood and di fferent weights to the neighbours. In particular, we estimate how far can reach indirect marginal e ffects and discuss how to report them. We also show that the use of smooth transition functions provides tools for policy analysis that are not available in the traditional threshold modelling. Keywords: count data models, industrial location, smooth transition functions, threshold models. JEL-Codes: C25, C52, R11, R30.

A general definition and nomenclature for alternative splicing events

Understanding the molecular mechanisms responsible for the regulation of the transcriptome present in eukaryotic cells isone of the most challenging tasks in the postgenomic era. In this regard, alternative splicing (AS) is a key phenomenoncontributing to the production of different mature transcripts from the same primary RNA sequence. As a plethora ofdifferent transcript forms is available in databases, a first step to uncover the biology that drives AS is to identify thedifferent types of reflected splicing variation. In this work, we present a general definition of the AS event along with anotation system that involves the relative positions of the splice sites. This nomenclature univocally and dynamically assignsa specific ‘‘AS code’’ to every possible pattern of splicing variation. On the basis of this definition and the correspondingcodes, we have developed a computational tool (AStalavista) that automatically characterizes the complete landscape of ASevents in a given transcript annotation of a genome, thus providing a platform to investigate the transcriptome diversityacross genes, chromosomes, and species. Our analysis reveals that a substantial part—in human more than a quarter—ofthe observed splicing variations are ignored in common classification pipelines. We have used AStalavista to investigate andto compare the AS landscape of different reference annotation sets in human and in other metazoan species and found thatproportions of AS events change substantially depending on the annotation protocol, species-specific attributes, andcoding constraints acting on the transcripts. The AStalavista system therefore provides a general framework to conductspecific studies investigating the occurrence, impact, and regulation of AS.

Alternative Solutions to Meet the Service Needs of Low Volume Bridges in lowa, June 2004

There is a nationwide need for a safe, efficient and cost effective transportation system. An essential component of this system is the bridges. Local agencies perhaps have an even greater task than federal and state agencies in maintaining the low volume road (LVR) bridge system due to lack of sufficient resources and funding. The primary focus of this study was to review the various aspects of off-system bridge design, rehabilitation, and replacement. Specifically, a reference report was developed to address common problems in LVR bridges. The source of information included both Iowa and national agencies. This report is intended to be a “user manual” or “tool box” of information, procedures and choices for county engineers to employ in the management of their bridge inventory plus identify areas and problems that need to be researched

Vasopressin-dependent coupling between sodium transport and water flow in a mouse cortical collecting duct cell line.

Water balance is achieved through the ability of the kidney to control water reabsorption in the connecting tubule and the collecting duct. In a mouse cortical collecting duct cell line (mCCD(c11)), physiological concentrations of arginine vasopressin increased both electrogenic, amiloride-sensitive, epithelial sodium channel (ENaC)-mediated sodium transport measured by the short-circuit current (Isc) method and water flow (Jv apical to basal) measured by gravimetry with similar activation coefficient K(1/2) (6 and 12 pM, respectively). Jv increased linearly according to the osmotic gradient across the monolayer. A small but highly significant Jv was also measured under isoosmotic conditions. To test the coupling between sodium reabsorption and water flow, mCCD(c11) cells were treated for 24 h under isoosmotic condition with either diluent, amiloride, vasopressin or vasopressin and amiloride. Isc, Jv, and net chemical sodium fluxes were measured across the same monolayers. Around 30% of baseline and 50% of vasopressin-induced water flow is coupled to an amiloride-sensitive, ENaC-mediated, electrogenic sodium transport, whereas the remaining flow is coupled to an amiloride-insensitive, nonelectrogenic sodium transport mediated by an unknown electroneutral transporter. The mCCD(c11) cell line is a first example of a mammalian tight epithelium allowing quantitative study of the coupling between sodium and water transport. Our data are consistent with the 'near isoosmotic' fluid transport model.

Médecines complémentaires: vers un consensus "evidence-based" à l'hôpital universitaire. [Complementary and alternative medicines (CAM): towards an "evidence-based" consensus in the University hospital]

Après la votation fédérale demandant de prendre en compte les médecines complémentaires, un consensus a été recherché dans quatorze services et unités du Centre hospitalier universitaire vaudois (CHUV). Confrontés aux données de la littérature (Plus de 2000 publications en "Evidence-based complementary medicine" depuis 1998), les soignants étaient tous surpris par l'ampleur des résultats cliniques disponibles actuellement. Tous identifiaient un besoin en formation et en informations sur le sujet. Une prise de position officielle de l'institution était aussi souhaitée, instituant l'enseignement et la recherche sur les médecines complémentaires et assurant la production d'informations rigoureuses et pertinentes pour la clinique. [Abstract] While a popular vote supported a new article on complementary and alternative medicines (CAM) in the Swiss Constitution, this assessment in 14 wards of the University Hospital of Lausanne, Switzerland, attempted at answering the question: How can CAM use be better taken into account and patients informed with more rigor and respect for their choices? Confronted with a review of the literature (> 2000 publications in "Evidence-based cornplementary medicine" since 1998), respondents declared their ignorance of the clinical data presently available on CAM. All were in favour of more teaching and information on the subject, plus an official statement from the Hospital direction, ensuring production and diffusion of rigorous and cJinically significant information on CAM.

Deciphering 3'ss selection in the yeast genome reveals an RNA thermosensor that mediates alternative splicing

Poor understanding of the spliceosomal mechanisms to select intronic 3' ends (3'ss) is a major obstacle to deciphering eukaryotic genomes. Here, we discern the rules for global 3'ss selection in yeast. We show that, in contrast to the uniformity of yeast splicing, the spliceosome uses all available 3'ss within a distance window from the intronic branch site (BS), and that in 70% of all possible 3'ss this is likely to be mediated by pre-mRNA structures. Our results reveal that one of these RNA folds acts as an RNA thermosensor, modulating alternative splicing in response to heat shock by controlling alternate 3'ss availability. Thus, our data point to a deeper role for the pre-mRNA in the control of its own fate, and to a simple mechanism for some alternative splicing.

Differentiated evolutionary rates in alternative exons and the implications for splicing regulation

Background: Alternatively spliced exons play an important role in the diversification of gene function in most metazoans and are highly regulated by conserved motifs in exons and introns. Two contradicting properties have been associated to evolutionary conserved alternative exons: higher sequence conservation and higher rate of non-synonymous substitutions, relative to constitutive exons. In order to clarify this issue, we have performed an analysis of the evolution of alternative and constitutive exons, using a large set of protein coding exons conserved between human and mouse and taking into account the conservation of the transcript exonic structure. Further, we have also defined a measure of the variation of the arrangement of exonic splicing enhancers (ESE-conservation score) to study the evolution of splicing regulatory sequences. We have used this measure to correlate the changes in the arrangement of ESEs with the divergence of exon and intron sequences. Results: We find evidence for a relation between the lack of conservation of the exonic structure and the weakening of the sequence evolutionary constraints in alternative and constitutive exons. Exons in transcripts with non-conserved exonic structures have higher synonymous (dS) and non-synonymous (dN) substitution rates than exons in conserved structures. Moreover, alternative exons in transcripts with non-conserved exonic structure are the least constrained in sequence evolution, and at high EST-inclusion levels they are found to be very similar to constitutive exons, whereas alternative exons in transcripts with conserved exonic structure have a dS significantly lower than average at all EST-inclusion levels. We also find higher conservation in the arrangement of ESEs in constitutive exons compared to alternative ones. Additionally, the sequence conservation at flanking introns remains constant for constitutive exons at all ESE-conservation values, but increases for alternative exons at high ESE-conservation values. Conclusion: We conclude that most of the differences in dN observed between alternative and constitutive exons can be explained by the conservation of the transcript exonic structure. Low dS values are more characteristic of alternative exons with conserved exonic structure, but not of those with non-conserved exonic structure. Additionally, constitutive exons are characterized by a higher conservation in the arrangement of ESEs, and alternative exons with an ESE-conservation similar to that of constitutive exons are characterized by a conservation of the flanking intron sequences higher than average, indicating the presence of more intronic regulatory signals.

Determination and Evaluation of Alternative Methods for Managing and Controlling Highway-Related Dust Phase II—Demonstration Project, June 2005

The State of Iowa currently has approximately 69,000 miles of unpaved secondary roads. Due to the low traffic count on these unpaved o nts as ng e two dust ed d roads, paving with asphalt or Portland cement concrete is not economical. Therefore to reduce dust production, the use of dust suppressants has been utilized for decades. This study was conducted to evaluate the effectiveness of several widely used dust suppressants through quantitative field testing on two of Iowa’s most widely used secondary road surface treatments: crushed limestone rock and alluvial sand/gravel. These commercially available dust suppressants included: lignin sulfonate, calcium chloride, and soybean oil soapstock. These suppressants were applied to 1000 ft test sections on four unpaved roads in Story County, Iowa. Tduplicate field conditions, the suppressants were applied as a surface spray once in early June and again in late August or early September. The four unpaved roads included two with crushed limestone rock and two with alluvial sand/gravel surface treatmewell as high and low traffic counts. The effectiveness of the dust suppressants was evaluated by comparing the dust produced on treated and untreated test sections. Dust collection was scheduled for 1, 2, 4, 6, and 8 weeks after each application, for a total testiperiod of 16 weeks. Results of a cost analysis between annual dust suppressant application and biennial aggregate replacement indicated that the cost of the dust suppressant, its transportation, and application were relatively high when compared to that of thaggregate types. Therefore, the biennial aggregate replacement is considered more economical than annual dust suppressant application, although the application of annual dust suppressant reduced the cost of road maintenance by 75 %. Results of thecollection indicated that the lignin sulfonate suppressant outperformed calcium chloride and soybean oil soapstock on all four unpavroads, the effect of the suppressants on the alluvial sand/gravel surface treatment was less than that on the crushed limestone rock, the residual effects of all the products seem reasonably well after blading, and the combination of alluvial sand/gravel surface treatment anhigh traffic count caused dust reduction to decrease dramatically.

Modification du style de vie : une alternative au traitement pharmacologique lors d'hypertension modérée

[But de l'étude] Il s'agit d'effectuer un projet pilote afin de développer la méthodologie pour une large étude et d'en examiner les possibilités de réalisation. Cette large étude devrait permettre de tester l'hypothèse qu'une thérapeutique non médicamenteuse de l'hypertension artérielle modérée est une alternative valable au traitement chimiothérapeutique en termes de résultats cliniques et de rapport coût/efficacité. [Auteurs, p. 4]