Who acquires infection from whom? Estimating herpesvirus transmission rates between wild rodent host groups

To date, few studies of parasite epidemiology have investigated ‘who acquires infection from whom’ in wildlife populations. Nonetheless, identifying routes of disease transmission within a population, and determining the key groups of individuals that drive parasite transmission and maintenance, are fundamental to understanding disease dynamics. Gammaherpesviruses are a widespread group of DNA viruses that infect many vertebrate species, and murine gammaherpesviruses (i.e. MuHV-4) are a standard lab model for studying human herpesviruses, for which much about the pathology and immune response elicited to infection is well understood. However, despite this extensive research effort, primarily in the lab, the transmission route of murine gammaherpesviruses within their natural host populations is not well understood. Here, we aimed to understand wood mouse herpesvirus (WMHV) transmission, by fitting a series of population dynamic models to field data on wood mice naturally infected with WMHV and then estimating transmission parameters within and between demographic groups of the host population. Different models accounted for different combinations of host sex (male/female), age (subadult/adult) and transmission functions (density/frequency-dependent). We found that a density-dependent transmission model incorporating explicit sex groups fitted the data better than all other proposed models. Male-to-male transmission was the highest among all possible combinations of between- and within-sex transmission classes, suggesting that male behaviour is a key factor driving WMHV transmission. Our models also suggest that transmission between sexes, although important, wasn’t symmetrical, with infected males playing a significant role in infecting naïve females but not vice versa. Overall this work shows the power of coupling population dynamic models with long-term field data to elucidate otherwise unobservable transmission processes in wild disease systems

RNA G-Quadruplexes in the model plant species Arabidopsis thaliana: prevalence and possible functional roles

Tandem stretches of guanines can associate in hydrogen-bonded arrays to form G-quadruplexes, which are stabilized by K+ ions. Using computational methods, we searched for G-Quadruplex Sequence (GQS) patterns in the model plant species Arabidopsis thaliana. We found ∼1200 GQS with a G3 repeat sequence motif, most of which are located in the intergenic region. Using a Markov modeled genome, we determined that GQS are significantly underrepresented in the genome. Additionally, we found ∼43 000 GQS with a G2 repeat sequence motif; notably, 80% of these were located in genic regions, suggesting that these sequences may fold at the RNA level. Gene Ontology functional analysis revealed that GQS are overrepresented in genes encoding proteins of certain functional categories, including enzyme activity. Conversely, GQS are underrepresented in other categories of genes, notably those for non-coding RNAs such as tRNAs and rRNAs. We also find that genes that are differentially regulated by drought are significantly more likely to contain a GQS. CD-detected K+ titrations performed on representative RNAs verified formation of quadruplexes at physiological K+ concentrations. Overall, this study indicates that GQS are present at unique locations in Arabidopsis and that folding of RNA GQS may play important roles in regulating gene expression

TBVAC2020 : advancing tuberculosis vaccines from discovery to clinical development

TBVAC2020 is a research project supported by the Horizon 2020 program of the European Commission (EC). It aims at the discovery and development of novel tuberculosis (TB) vaccines from preclinical research projects to early clinical assessment. The project builds on previous collaborations from 1998 onwards funded through the EC framework programs FP5, FP6, and FP7. It has succeeded in attracting new partners from outstanding laboratories from all over the world, now totaling 40 institutions. Next to the development of novel vaccines, TB biomarker development is also considered an important asset to facilitate rational vaccine selection and development. In addition, TBVAC2020 offers portfolio management that provides selection criteria for entry, gating, and priority settings of novel vaccines at an early developmental stage. The TBVAC2020 consortium coordinated by TBVI facilitates collaboration and early data sharing between partners with the common aim of working toward the development of an effective TB vaccine. Close links with funders and other consortia with shared interests further contribute to this goal

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

La gestion intégrée de la zone côtière au Québec : un regard sur 10 ans de pratique

La gestion intégrée de la zone côtière est une approche adoptée par plusieurs pays afin de répondre aux enjeux environnementaux et socio-économiques permettant l’implication des collectivités côtières dans le processus de prise de décisions. Au Canada, la Loi sur les océans promulguée en 1997 offre un cadre légal pour la gestion intégrée des océans et des zones côtières.  Dans les années subséquentes, des professionnels du ministère des Pêches et des Océans, région administrative du Québec, ont développé une démarche méthodologique et proposé un modèle général d’application de la gestion intégrée de la zone côtière (GIZC) adaptés aux collectivités.  Plusieurs initiatives communautaires se sont inspirées de cette démarche et ont développé, au fil des années, leur propre expertise et compétence en GIZC. Les deux initiatives examinées dans le cadre de cet article ont été mises en place selon des modes différents. La détermination de leur territoire d’action, de leur structure, de leur fonctionnement et de leurs actions est adaptée aux particularités de leur milieu et des acteurs impliqués. Dans les deux cas, les réalisations et retombées concrètes qui en découlent démontrent le dynamisme et la volonté des collectivités côtières à s'impliquer dans la gestion de leur milieu. Les deux initiatives ont réussi à maintenir la mobilisation d'une vaste gamme d'intervenants et à se positionner comme des acteurs majeurs pour le développement de leur communauté. En élargissant l'examen aux autres initiatives de GIZC au Québec, les mêmes constats peuvent s'appliquer. Ne s'étant pas doté de processus de suivi et d'évaluation, le rôle et les actions des initiatives demeurent toutefois méconnus en dehors de leur cercle d’influence. Aujourd’hui au Québec, les organismes gouvernementaux, tant fédéraux que provinciaux, reconnaissent la gestion intégrée comme approche à privilégier et souhaitent sa mise en place pour le Saint-Laurent. Une entente Canada-Québec sur le Saint-Laurent (2005-2010) vise notamment la mise en place d’un modèle de gouvernance pour la gestion intégrée de ce grand cours d’eau. Il y a donc une occasion pour les intervenants locaux, régionaux et communautaires impliqués ou intéressés à la GIZC de faire connaître et reconnaître l'expérience et l'expertise acquises ces dix dernières années.Integrated coastal zone management is an approach that has been adopted by a number of countries in order to address environmental and socio-economic issues and allow coastal communities to participate in the decision-making process. In Canada, the Oceans Act, enacted in 1997, provides a legal framework for the integrated management of oceans and coastal zones. Since the legislation was passed, experts with the federal Department of Fisheries and Oceans, Quebec Region, have developed a methodological approach and proposed a general model for integrated coastal zone management (ICZM) that enables communities to play a central role. A number of communities have drawn inspiration from this approach in carrying out their own initiatives and, over the years, these communities have developed expertise and know-how in the area of ICZM. The two initiatives discussed in this document involved different modes of implementation. Their geographic area of action, structure, mode of operation and activities have all been defined with reference to the unique attributes of the local environment and the actors involved. The accomplishments and concrete benefits resulting from the two initiatives attest to the coastal communities’ dynamism and their desire to play an active role in managing their environment. In both cases, a wide range of stakeholders has been mobilized and have become key players in the development of their communities. A broader study encompassing other ICZM initiatives in Quebec would yield similar findings. Since no monitoring or evaluation procedures have been put in place for these coastal zone initiatives, their role and their activities have not received attention outside their respective zones of influence. At present, in Quebec, federal and provincial government agencies view integrated management as a valuable approach and one that should be implemented for the benefit of the St. Lawrence. The goal of the Canada–Quebec Agreement on the St. Lawrence (2005-2010) is to put in place a governance model for the integrated management of this major waterway. This approach provides the opportunity for local, regional and community stakeholders who are already engaged in or want to take part in ICZM to give visibility to and recognize the experience and expertise acquired in this area over the past 10 years

Using angular speed measurement with Hall effect sensors to observe grinding operation with flexible robot

Hydro-Quebec has developed and implemented a portable robotic technology to facilitate the maintenance of hydraulic turbines. To improve the quality of the grinding, it is thus necessary to reduce the vibrations caused by the flexibility of the portable robot «SCOMPI». Steady vibration responses of the dynamic model during grinding shows repeating and high frequency impacts between the wheel and workpiece. High speed camera observations confirm the existence of a vibro-impact process. From our experiments, it is shown that angular speed signal can be very useful for monitoring grinding, by detecting the exact location on the wheel and energy content of each impact. These detections can allow online modification of the commands of the robot, such as normal force or feed speed, so as to better control the material removal rate. A comparison between built in Hall effect sensors and added encoder shows too many differences, and even if the first results are promising, an improved encoder need to be designed

Angular analysis of the cyclic impacting oscillations in a robotic grinding process

International audienceIn a robotic machining process, a light-weight cutter or grinder is usually held by an articulated robot arm. Material removal is achieved by the rotating cutting tool while the robot end effector ensures that the tool follows a programmed trajectory in order to work on complex curved surfaces or to access hard-to-reach areas. One typical application of such process is maintenance and repair work on hydropower equipment. This paper presents an experimental study of the dynamic characteristics of material removal in robotic grinding, which is unlike conventional grinding due to the lower structural stiffness of the tool-holder robot. The objective of the study is to explore the cyclic nature of this mechanical operation to provide the basis for future development of better process control strategies. Grinding tasks that minimize the number of iterations to converge to the target surface can be better planned based on a good understanding and modeling of the cyclic material removal mechanism. A single degree of freedom dynamic analysis of the process suggests that material removal is performed through high-frequency impacts that mainly last for only a small fraction of the grinding disk rotation period. To detect these discrete cutting events in practice, a grinder is equipped with a rotary encoder. The encoder's signal is acquired through the angular sampling technique. A running cyclic synchronous average is applied to the speed signal to remove its non-cyclic events. The measured instantaneous rotational frequency clearly indicates the impacting nature of the process and captures the transient response excited by these cyclic impacts. The technique also locates the angular positions of cutting impacts in revolution cycles. It is thus possible to draw conclusions about the cyclic nature of dynamic changes in impact-cutting behavior when grinding with a flexible robot. The dynamics of the impacting regime and transient responses to impact-cutting excitations captured synchronously using the angular sampling technique provide feedback that can be used to regulate the material removal process. The experimental results also make it possible to correlate the energy required to remove a chip of metal through impacting with the measured drop in angular speed during grinding

Balloon-borne sample analysis of organic compounds present across atmospheric layers ranging from the troposphere to lower stratosphere

International audienceAtmospheric aerosols play an important role in the Earth’s climate system. We present the analysis of atmospheric molecules/particles collected with a sampling system that can fly under regular weather balloons. The flights took place on 10 October 2022 from Reims and on 13 December 2022 from Orléans (France). The samples collected on activated carbon filters were analyzed by high-resolution mass spectrometry (Orbitrap Q-Exactive). Using Desorption electrospray ionization (DESI), we could derive hundreds of chemical formulas for organic species present in different layers from the troposphere to the stratosphere (up to 20 km). Measurements of O3, CO, and aerosol concentrations a few hours before these flights took place to contextualize the sampling. Chemical analysis of samples taken at different altitudes shows, in addition to a common set of chemical compounds, significant differences in the number and size of organic species detected. This finding must reflect the unique composition of the atmospheric layers, but also a common pattern of organic compounds. In the tropospheric samples, we found significant oxidised and saturated components, with carbon numbers below 30, which could be explained by complex organic chemistry originating from local and distant emission sources. In samples from the upper troposphere and stratosphere, we detected chemical formulae with higher carbon numbers (C>30). Significantly lower unsaturation numbers were observed in the compounds collected in the stratosphere, which could be the result of UV radiation.The multimodal distributions of carbon numbers in chemical formulas observed between 15-20 km suggest that oligomerization and growth of organic molecules may take place in aged air masses of tropical origin that are known to carry organic compounds even several km above the tropopause where their lifetime significantly increases. Overall, these results are consistent with the injection of fire smoke months before the in-situ observations and with thermodynamics inherent to conditions prevailing in the stratosphere This new analysis method meets the requirements of balloon flights in terms of flexibility and cost