Langage intermédiaire et transformations de modèles pour le développement de systèmes temps-réel : retour d'expérience sur la chaîne de vérification formelle Fiacre

6 pagesInternational audienceWe discuss the results obtained during the development of a formal verification toolchain for AADL based on a model driven engineering approach. Our approach is characterized by the use of the pivot language FIACRE to facilitate verification activities and transformations between models. We quickly analyse the first return on experience and present ongoing work started in the scope of the Quarteft project to improve the verification chain.Nous présentons les résultats obtenus durant le développement d’une chaîne de vérifi-cation formelle pour le langage d’architecture AADL basé sur une approche ingénierie dirigéepar les modèles. Notre approche se caractérise par l’utilisation du langage pivot FIACRE pourfaciliter les activités de vérification et de transformations entre modèles. Nous commentonsles premiers retours d’expérience issus de la mise en oeuvre de cette chaîne de vérification etprésentons en conclusion les travaux en cours dans le cadre du projet Quarteft qui visent àl’améliore

Formal Verification of AADL models with Fiacre and Tina

9 pagesInternational audienceThis paper details works undertaken in the scope of the Spices project concerning the behavioral verification of AADL models. We give a high-level view of the tools involved and describe the successive transformations performed by our verification process. We also report on an experiment carried out in order to evaluate our framework and give the first experimental results obtained on real-size models. This demonstrator models a network protocol in charge of data communications between an airplane and ground stations. From this study we draw a set of conclusions about the integration of model-checking tools in an industrial development process

Condensed Matter Theory of Dipolar Quantum Gases

Recent experimental breakthroughs in trapping, cooling and controlling ultracold gases of polar molecules, magnetic and Rydberg atoms have paved the way toward the investigation of highly tunable quantum systems, where anisotropic, long-range dipolar interactions play a prominent role at the many-body level. In this article we review recent theoretical studies concerning the physics of such systems. Starting from a general discussion on interaction design techniques and microscopic Hamiltonians, we provide a summary of recent work focused on many-body properties of dipolar systems, including: weakly interacting Bose gases, weakly interacting Fermi gases, multilayer systems, strongly interacting dipolar gases and dipolar gases in 1D and quasi-1D geometries. Within each of these topics, purely dipolar effects and connections with experimental realizations are emphasized.Comment: Review article; submitted 09/06/2011. 158 pages, 52 figures. This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in Chemical Reviews, copyright American Chemical Society after peer review. To access the final edited and published work, a link will be provided soo

FUNCTIONAL ANALYSIS OF MAIZE GENES INVOLVED IN SEEDLING DEVELOPMENT AND IN PLANT ¿ ENVIRONMENT INTERACTION

Maize is one of the most important cultivated plants on a world scale, with a total production which exceeds one billion tonnes per year (FAOSTAT 2017). It is an important human food source in many parts of the world, but is also intensely exploited for biofuel and feed production. Furthermore, maize is also a model plant for research studies in the field of biology and genetics. For these reasons, maize is one of the most intensively studied crops, with the aim of improving its productivity, which in the USA has increased nearly five times since the 1940s. This dramatic yield improvement is due to the development and widespread use of new farming technologies. An important role was played by genetic improvement, with the use of highly productive maize hybrids and, more recently, biotechnology. However, the increases in annual productivity of maize and the other main crops exploited for food production seem to have reached a stall phase in recent years. It has been estimated that the world population will increase from 7.5 to 9.7 billion people by 2050. To meet the food needs of the increasing population, and to satisfy diets that will include more meat, according to the Food and Agricultural Organization (FAO), worldwide crop production will have to increase by 70%. It is a tough task, made even more difficult by the fact that the worldwide area of cultivable soil is decreasing as a consequence of increasing urbanization and climate change. To reach the target, new strategies are required, which will include multiple and integrated approaches, among them genetic improvement. One of the main challenges will be to develop new plant ideotypes that will combine the capability to tolerate biotic and abiotic stress with no reduction in yield. Within this perspective, the work carried out in this thesis project was aimed at understanding the molecular mechanisms involved in plant response to environmental factors. The work was organized in two parts, which are presented here in two different chapters. Both chapters are focused on genes that control plant development as well as plant- environment interactions. The first chapter deals with the study of the genetic regulation of cuticle deposition in maize. The cuticle is an important plant organ and constitutes the first barrier against many environmental stresses, including water deprivation and pathogen interaction. The cuticle is produced by epidermal cells and is composed of a complex array of long chain hydrocarbons, constantly deposed on the aerial surface for all the plant\u2019s life. To investigate the cuticle biosynthesis process in maize, our strategy was based on the functional characterization of ZmMYB94, also known as fused leaves 1 (fdl1). This gene encodes a transcription factor of the R2R3-MYB subfamily, expressed in embryo, seedling and silk tissues. A mutant in this gene, referred to as fdl1-1, was available for this study. It originated from the insertion of an Enhancer/Suppressor (En/Spm) element in the third exon of the ZmMYB94 gene. The mutation has a pleiotropic effect on seedling development. The main features of fdl1-1 mutant plants are irregular coleoptile opening and the presence of regions of adhesion between the coleoptile and the first leaf and between the first and second leaves. Deeper studies of the fdl1-1 mutant, performed by electron microscopy analysis, showed that, in regions of organ adhesion, cuticle was absent and, on the epidermal surface, epicuticular wax deposition occurred irregularly. These observations led to the hypothesis that phenotypic alterations observed in the mutant seedlings may be attributable to defects in the cuticle-related biosynthetic pathways. To gain insight into the role of fdl1 in controlling cuticle formation, a large-scale RNA sequencing analysis was carried out in this work. By means of this approach, more than one thousand differentially expressed genes (DEGs) were found in the fdl1-1 mutant compared with the wild type seedling transcriptome. The analysis of single DEGs confirmed that fdl1 is involved in the regulation of the biosynthesis of both cuticle components, since genes for the cuticular waxes deposition as well as cutin biosynthesis were detected. In particular, five genes with a reduced expression level and one with an increased expression level in the fdl1-1 mutant encoded for enzymes involved in the Fatty acid elongation complex, the main source of basic compounds exploited in cutin and waxes biosynthesis. Furthermore, two genes found with a reduced expression level in the mutant were also involved in the cutin biosynthesis. Interesting sidelights on these two genes are available from the study of their orthologues in rice (OsONI3) and in Arabidopsis (AtEDA17). The knock-out mutant of ONI3 in rice shows a phenotype that is very similar to that of the fdl1-1 mutant in maize, with defects in cutin deposition and fusions between the coleoptile and the first leaves. Moreover, the knock-out mutant of EDA17 in Arabidopsis shows defects in cutin deposition and fusions between floral organs. Other two genes found differentially expressed in fdl1-1 encode for enzymes involved in epicuticular waxes biosynthesis, thus explaining the defects observed in fdl1-1 mutants. On the basis of these observations, we developed a model that explains the mode of action of fdl1 in controlling cuticle formation. Furthermore, the large-scale RNA sequencing analysis done in this study revealed a considerable number of genes differentially expressed in the fdl1-1 mutant that are involved in other important processes, such as plant clock regulation, plant pathogen interaction and hormone signalling. A deeper investigation of the role of these genes will be of help in elucidating the action of fdl1 in controlling different aspects of plant development. We also demonstrated in the present study that fdl1 is actively involved in the drought stress response in maize seedlings. Indeed, an expression analysis showed strong differences in the fdl1 transcript level in seedlings exposed to drought stress condition compared with seedlings grown in well-watered conditions. Indeed, in normally watered plants, the fdl1 transcript level constantly increased during leaf expansion, until it reached a high expression level. In plants exposed to drought stress conditions, the fdl1 transcript level showed a different pattern, with a strong increment in the first day of stress, and then a decrease until the initial level was reached and maintained for the whole duration of drought conditions. We may speculate that the involvement of fdl1 in the plant response to drought conditions, consists in promoting a modification of cuticle composition that will reduce water loss. To further investigate the involvement of fdl1 in drought stress tolerance, its orthologous gene was identified in Eragrostis curvula. This species is particularly interesting for our purposes, because its genome is very similar to the maize genome. Furthermore, unlike maize, in Eragrostis different ecotypes, characterized by different drought stress tolerance, have been described. In a preliminary analysis, we observed that the expression pattern of Ecfdl1 is different among three Eragrostis ecotypes. Differently from what was observed in maize, Ecfdl1 appeared to be expressed in different adult tissues. Moreover, differences in the Ecfdl1 expression profile were detected in different ecotypes. Besides in young maize tissues, fdl1 also appears to have an active role in controlling cuticle deposition in silk tissues. We detected differences between the fdl1-1 mutant and wild type plants in the composition of the wax layer covering the silks. Since maize silks constitute the main route of entry for pathogens to reach the seeds, in our opinion the differences found in silk coverage can influence the plant-pathogen interaction. This hypothesis was confirmed by comparing fusarium ear rot symptoms between wild type and fdl1-1 mutant ears experimentally inoculated with Fusarium verticillioides in a two year experiment. Our results seem to indicate that the fdl1-1 mutant is less susceptible to fusarium infection compared with the wild type. In conclusion to this part of the work, our studies provided details about the involvement of fdl1 in the regulation of cuticle biosynthesis and deposition during two of the most important moments of the plant life cycle: the seedling stage and silk development. Furthermore, in these two delicate moments, we have evidence showing that fdl1 plays an active role in drought stress response and pathogen interaction. In the second chapter, the role of brassinosteroids (BRs) in leaf permeability and architecture was further analysed. BRs are a class of steroid hormones essential for plant growth and development. BRs are involved in many developmental traits of agronomic importance such as seed germination, plant architecture, flowering time and seed yield. In addition to having an important role in development, brassinosteroids exert anti-stress effects on plants and are essential for the ability of plants to adapt to abiotic stresses. This part of the work was focused on the characterization of the maize lilliputian1-1 (lil1-1) mutant, which is impaired in one of the last steps of brassinosteroid biosynthesis. The subtending gene putatively encodes for a brassinosteroid C-6 oxidase (brC-6 oxidase). The mutant appears severely compromised in height, floral development and overall plant architecture. Leaf primordia are more compressed compared with wild type, and mutant leaves appear thicker than wild type leaves, exhibiting altered shape and the presence of supernumerary cell layers in the mesophyll region between the leaf vessels and the adaxial leaf epidermis. In this study, alterations in epicuticular waxes deposition were found in the lil1-1 mutant. Furthermore, it was shown that the leaf epidermis of lil1-1 shows a significantly lower permeability than wild type. These findings are in accordance with previous observations obtained in our laboratory, which showed that the lil1-1 mutant shows a better dehydration tolerance. In our hypothesis, the thicker epidermis observed in lil1-1 compared with wild type, can explain the lower permeability and the better dehydration tolerance. Furthermore, in this chapter we used the lil1-1 mutant to better investigate the BRs biosynthesis pathway. This is a complex pathway and, although it has been the subject of several studies in recent years, some aspects are still to be clarified. For this purpose, we analysed the interaction between the lil1-1 mutant, and another well-known maize BRs mutant, i.e. the nana1-1 (na1-1) mutant. Both nana1 and lil1 genes have key roles in the BR biosynthesis pathway. The product of nana1 is involved in two parallel pathways, therefore lack of its action may lead to an interruption of both. The lil1 gene product, however, is involved in the last steps of the pathway, leading to the formation of castasterone and brassinolide. Our analysis revealed that lil1-1 is epistatic to na1-1. These data suggest the existence in the maize BR pathway of an additional na1-independent branch leading to the production of CS precursors. In conclusion, this part of the work demonstrated the involvement of brassinosteroids in passive leaf permeability and provided new information that will be useful to unravel the complex BR biosynthetic pathway in plants. Overall, the work developed in this thesis project provides indications useful to better understanding the genetic mechanisms that regulate plant resistance to drought and pathogens. A good comprehension of these mechanisms can ultimately be useful to identify new genetic tools of interest, and to develop crops more adapted to the challenges of the future. Because of the appointment with 2050, only 32 annual production cycles remain

The spatial coverage of dairy cattle urine patches in an intensively grazed pasture system

Accurate field data on the paddock area affected by cow urine depositions are critical to the estimation and modelling of nitrogen (N) losses and N management in grazed pasture systems. A new technique using survey-grade global positioning system (GPS) technology was developed to precisely measure the paddock spatial area coverage, diversity and distribution of dairy cattle urine patches in grazed paddocks over time. A 4-year study was conducted on the Lincoln University Dairy Farm (LUDF), Canterbury, New Zealand, from 2003 to 2007. Twelve field plots, each 100m² in area, were established on typical grazing areas of the farm. All urine and dung deposits within the plots were visually identified, the pasture response area (radius) measured and position marked with survey-grade GPS. The plots were grazed as part of the normal grazing rotation of the farm and urine and dung deposits measured at 12-week intervals. The data were collated using spatial (GIS) software and an assessment of annual urine patch coverage and spatial distribution was made. Grazing intensities ranged from 17645 to 30295 cow grazing h/ha/yr. Mean annual areas of urine patches ranged from 0·34 to 0·40m² (4-year mean 0·37±0·009m²), with small but significant variation between years and seasons. Mean annual urine patch numbers were 6240±124 patches/ha/yr. The mean proportional area coverage for a single sampling event or season was 0·058 and the mean proportional annual urine patch coverage was 0·232±0·0071. There was a strong linear relationship between annual cow grazing h/ha and urine patch numbers/ha (R²=0·69) and also annual urine patch area coverage (R²=0·77). Within the stocking densities observed in this study, an annual increase of 10 000 cow grazing h/ha increased urine patch numbers by 1800 urine patches/ha/yr and annual urine patch area coverage by 0·07. This study presents new quantitative data on urine patch size, numbers and the spatial coverage of patches on a temporal basis

Primer registro de cría del Águila Crestuda Real (Spizaetus ornatus) en el sur de Brasil

We provide the first record of breeding of the Ornate Hawk-Eagle (Spizaetus ornatus) for southern Brazil. In September 2005 a nest was found inside the reservoir of the Barra Grande Hydroelectric Power Station, northern Rio Grande do Sul. On the nest there was a nestling around two months old. Based in prey remains collected on the nest, birds were the main item in diet. This is an endangered species in the Atlantic Rain Forest biome in Brazil and the presence of the nest and nestling offer evidence of reproduction in Southern Brazil.Se presenta el primer registro de cría del Águila Crestuda Real (Spizaetus ornatus) en el sur de Brasil. Se encontró un nido en septiembre de 2005 en el embalse de la usina hidroeléctrica Barra Grande, en el norte de Rio Grande do Sul. En el nido había un pichón de unos dos meses de edad. Sobre la base de los restos de presas encontrados en el nido, las aves eran los principales ítems en la dieta. Esta especie se encuentra en peligro de extinción en el Bosque Atlántico en Brasil y la presencia del nido y el pichón ofrece pruebas de la reproducción de la especie en el sur de Brasil

Universal hydrophilic coating of thermoplastic polymers currently used in microfluidics

A number of materials used to fabricate disposable microfluidic devices are hydrophobic in nature with water contact angles on their surface ranging from 80 to over 100. This characteristic makes them unsuitable for a number of microfluidic applications. Both the wettability and analyte adsorption parameters are highly dependent on the surface hydrophobicity. In this article, we propose a general method to coat the surface of five materials: polydimethylsiloxane (PDMS), cyclic olefin copolymer (COC), polyethylene terephthalate (PET), polycarbonate (PC), and polytetrafluoroethylene (PTFE). This fast and robust process, which is easily implementable in any laboratory including microfabrication clean room facilities, was devised by combining gas-phase and wet chemical modification processes. Two different coatings that improve the surface hydrophilicity were prepared via the "dip and rinse" approach by immersing the plasma oxidized materials into an aqueous solution of two different poly(dimethylacrylamide) copolymers incorporating a silane moiety and functionalized with either N-acryloyloxysuccinimide (NAS) (poly(DMA-NAS-MAPS) or glycidyl methacrylate (GMA) (poly(DMA-GMA-MAPS). The coating formation was confirmed by contact angle (CA) analysis comparing the variation of CAs of uncoated and coated surfaces subjected to different aging treatments. The antifouling character of the polymer was demonstrated by fluorescence and interferometric detection of proteins adsorbed on the surafce. This method is of great interest in microfluidics due to its broad applicability to a number of materials with varying chemical compositions

The S phase checkpoint promotes the Smc5/6 complex dependent SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε

Replication fork stalling and accumulation of single-stranded DNA trigger the S phase checkpoint, a signalling cascade that, in budding yeast, leads to the activation of the Rad53 kinase. Rad53 is essential in maintaining cell viability, but its targets of regulation are still partially unknown. Here we show that Rad53 drives the hyper-SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε, principally following replication forks stalling induced by nucleotide depletion. Pol2 is the main target of SUMOylation within the replisome and its modification requires the SUMO-ligase Mms21, a subunit of the Smc5/6 complex. Moreover, the Smc5/6 complex co-purifies with Pol ε, independently of other replisome components. Finally, we map Pol2 SUMOylation to a single site within the N-terminal catalytic domain and identify a SUMO-interacting motif at the C-terminus of Pol2. These data suggest that the S phase checkpoint regulate Pol ε during replication stress through Pol2 SUMOylation and SUMO-binding abilit

“Pacchetto lavoro” e assenza di contenuti previdenziali

Con il recente “Pacchetto Lavoro” varato con d.l. 28 giugno 2013, n. 76, conv. con modif. dalla l. 9 agosto 2013, n. 99 il legislatore interviene ancora sul mercato del lavoro, secondo una prospettiva di affannosa ri-cerca di quella ideale configurazione dello stesso in grado di accompagnare, in modo più efficace, la ripresa economica e la crescita dell’occupazione. Detto della consueta difficoltà di lettura del testo legislativo nel suo complesso considerato, testo, peraltro, ancora una volta infarcito di continui rinvii ad altri testi normati-vi già per loro conto strutturalmente complessi, nel presente scritto si tenta un primo rapido esame di quel-le disposizioni che più direttamente interessano l’ambito previdenziale. Il reticolato normativo costituito dal d.l. n. 76 del 2013, come convertito dalla l. n. 99 del 2013, oltre ad avere come suo “entroterra” legislativo necessitato la difficile situazione economico-sociale che attraversa il nostro Paese, contempla anche, per l’individuazione della ratio a esso sottesa, il complessivo quadro di riferimento del mercato del lavoro, nella sua configurazione attuale come delineato dagli ultimi interventi legislativi sulla materia. Per queste ragioni, dunque, il contributo muove dalla complessa odierna fase congiunturale e dalle ragioni dell’intervento legi-slativo qui in esame, per poi giungere, dopo alcune brevi considerazioni generali sulle misure adottate dal Governo, nel loro complesso considerate, alla individuazione dei caratteri “previdenziali” delle misure stes-se (e, soprattutto, di quello che, sotto tale profilo, è ancora una volta assente)