Subject-specific musculoskeletal model of the lower limb in a lying and standing position

Accurate estimation of joint loads implies using subject-specific musculoskeletal models. Moreover, as the lines of action of the muscles are dictated by the soft tissues, which are in turn influenced by gravitational forces, we developed a method to build subject-specific models of the lower limb in a functional standing position. Bones and skin envelope were obtained in a standing position, whereas muscles and a set of bony landmarks were obtained from conventional magnetic resonance images in a lying position. These muscles were merged with the subject-specific skeletal model using a nonlinear transformation, taking into account soft tissue movements and gravitational effects. Seven asymptomatic lower limbs were modelled using this method, and results showed realistic deformations. Comparing the subject-specific skeletal model to a scaled reference model rendered differences in terms of muscle length up to 4% and in terms of moment arm for adductor muscles up to 30%. These preliminary findings enlightened the importance of subject-specific modelling in a functional position

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

Directorium divini cultus ad Cathedralis Ecclesiae Minoriccensis : eiusque Dioecesis usum

Fecha de imprenta tomada del título

Effects of leaf surface and temperature on monocyclic processes in Podosphaera aphanis, causing powdery mildew of strawberry

International audiencePowdery mildew of strawberry, caused by Podosphaera aphanis, is an important constraint to production in tunnels and greenhouses. A better knowledge of the effect of environment on the disease is needed to design efficient management methods. In diseases such as strawberry powdery mildew, the very notion of lesion is difficult to grasp, and progress in disease management has been slow because observations pertaining to the monocyclic processes are difficult and time consuming. Experiments under controlled conditions were conducted to measure the effects of leaf surface (abaxial or adaxial) and air temperature on the different monocyclic processes of the disease. The fraction of germinated spores on the lower (abaxial) leaf surface (0.51–0.84) was 10%-20% larger than on the upper (adaxial) leaf surface. Infection efficiency was 10 times lower on the upper than on the lower leaf surface. Temperature strongly influenced all monocyclic processes considered: spore germination, infection efficiency, latent period, colony size, and colony sporulation. The optimum temperature was 22 °C, and no infection occurred at 32 °C. Implications of the results on disease management are discussed.L’oïdium du fraisier, causé par Podosphaera aphanis, est une importante contrainte pour la production de fraisiers en serre et sous tunnel. Une meilleure connaissance des effets de l’environnement sur cette maladie est nécessaire pour élaborer des méthodes de gestion efficaces. Comme c’est le cas pour de nombreuses maladies telles que l’oïdium du fraisier, où la notion même de lésion est difficile à appréhender, les progrès pour la gestion de cette maladie ont été lents car les observations liées aux processus monocycliques sont difficiles et laborieuses. Des expérimentations en conditions contrôlées ont été conduites pour mesurer les effets de la température de l’air et de la surface de feuille (abaxiale ou adaxiale) sur les différents processus monocycliques de cette maladie. Le taux de germination sur face inférieure (abaxiale) de feuilles (0.51–0.84) était 10 % à 20 % plus grand que sur la face supérieure (adaxiale). L’efficacité d’infection était 10 fois plus faible sur la face supérieure que sur la face inférieure de feuille. La température influençait fortement tous les processus monocycliques considérés : germination des spores, efficacité d’infection, période de latence, taille des colonies, sporulation. La température optimale était de 22 °C, et aucune infection ne s’est développée à 32 °C. Les implications de ces résultats pour la gestion de cette maladie sont discutées

Genetic structure and aggressiveness of Erysiphe necator populations during grapevine powdery mildew epidemics

International audienceIsolates of the causal ascomycete of grapevine powdery mildew, Erysiphe necator, correspond to two genetically differentiated groups (A and B) that coexist on the same host. This coexistence was analyzed by investigating temporal changes in the genetic and phenotypic structures of E. necator populations during three epidemics. Group A was present only at the start of the growing season, whereas group B was present throughout all three epidemics. Group A was less aggressive in terms of germination and infection efficiency but was more aggressive than group B in terms of the latency period, lesion diameter, and spore production. Our results are consistent with a temporal differentiation of niches, preventing recombination, and suggest an association between the disease level and the frequencies of genetic groups

Polar coastal soundscapes: Tridimensional mapping of benthic biophony and ice geophony with a compact sensor array

International audiencePolar areas show fast changes linked to global warming. The reduction of the ice pack and the melting of the ice sheet modify the conditions of living of marine fauna. We propose the simultaneous monitoring of the ice and benthic fauna using passive acoustics. Thanks to a compact sensor array of 4 hydrophones (2m*2m*2m), we detected, localized and mapped in three dimensions ({azimuth, elevation} or {x, y, z}) the biophonic and geophonic contributions made up of short and wideband pulses. Tridimensional maps of benthic biophony and ice geophony of Antarctic and Arctic 7 days-long recording sessions (2015, 2016) are built and analyzed over a surface of the order of 1 km2. Benthic invertebrates emit high energetic pulses with peak frequencies ranging from 2 to 55 kHz, most of them below 15 kHz. Geophony is structured into two parts. The ice sheet, located several kilometers or tens of kilometers away, creates a stable spatial distribution of low energetic pulses (representing the majority of pulses in the soundscape) modulated by the temporal variability. The movements of isolated icebergs or pack ice produce localized acoustic events identifiable by the high sound levels and the stable peak frequencies of the emitted pulses

Simultaneous quantification of sporangia and zoospores in a biotrophic oomycete with an automatic particle analyzer: Disentangling dispersal and infection potentials

Quantitative pathogenicity traits drive the fitness and dynamics of pathogens in agricultural ecosystems and are key determinants of the correct management of crop production over time. However, traits relating to infection potential (i.e. zoospore production) have been less thoroughly investigated in oomycetes than traits relating to dispersal (i.e. sporangium production). We simultaneously quantified sporangium and zoospore production in a biotrophic oomycete, for the joint assessment of life-cycle traits relating to dispersal and infection potentials. We used an automatic particle analyzer to count and size the sporangia and/or zoospores produced at t = 0 min (no zoospore release) and t = 100 min (zoospore release) in 43 Plasmopara viticola isolates growing on the susceptible Vitis vinifera cv. Cabernet Sauvignon. We were able to differentiate and quantify three types of propagules from different stages of the pathogen life cycle: full sporangia, empty sporangia and zoospores. The method was validated by comparing the sporangium and zoospore counts obtained with an automatic particle analyzer and under a stereomicroscope (manual counting). Each isolate produced a mean of 5.8 ± 1.9 (SD) zoospores per sporangium. Significant relationships were found between sporangium production and sporangium size (negative) and between sporangium size and the number of zoospores produced per sporangium (positive). However, there was a significant positive correlation between total sporangium production and total zoospore production. This procedure can provide a valid quantification of the production of both sporangia and zoospores by oomycetes in large numbers of samples, facilitating joint estimation of the dispersal and infection potentials of plant pathogens in various agro-ecological contexts

Polar Coastal Soundscapes : tridimensional mapping with a compact 4 hydrophones array

International audienc