Estimating sharka dispersal function by stochastic spatiotemporal modelling

Plant viral diseases, and especially the ones transmitted by aerial vectors, can cause considerable yield losses. A good knowledge of the distances of spread is key to the understanding of disease dynamics. Exploratory approaches aiming at characterizing the spatiotemporal distribution of diseased plants are often used to get an insight into the distances of spread. A more powerful approach is based on stochastic spatiotemporal modelling in order to estimate the dispersal function of the disease (probability density function describing the probability for an infectious plant to infect a healthy plant at distance d). In this study, we implemented a method for estimating the dispersal function of the sharka disease. Sharka is one of the most serious diseases of stone fruit trees (Prunus sp.). It is caused by Plum pox virus (PPV, genus Potyvirus), transmitted by at least twenty different aphid species in a non persistent manner. Due to the inefficiency of insecticides and the very rare sources of resistance against the virus available in the host species, prophylactic disease control is based on the removal of the diseased trees in the orchards. Thus, a very good knowledge of the dispersal function of sharka is crucial for building epidemiological models and optimizing the strategies of surveillance and control. We adapted the methodology published by Gibson (1997) based on a Markov chain Monte Carlo (MCMC) algorithm in order to estimate sharka dispersal function from the maps of 157 contiguous peach orchards reporting the exact location and the sanitary status (asymptomatic/symptomatic) of each of the trees during six consecutive years. An estimation method based on the Gibbs sampling algorithm was developed taking into account the specificities of the dataset (more than two dates of observation, annual removal of diseased trees). This estimation algorithm was validated on simulated data and was proved to be more powerful and better adapted to large datasets than the one proposed by Gibson. Moreover, the influence of latency on the estimation of the dispersal function was quantified. This methodology was then used to estimate the dispersal function of the disease from a subset of the real dataset. The methods developed in this study are generic enough to be used and adapted for the estimation of dispersal functions of any disease transmitted in a non persistent manner, and even for diseases with similar characteristics. (Texte intégral

Tooth wear as a means to quantify intra-specific variations in diet and chewing movements

9 pagesInternational audienceIn mammals, tooth function, and its efficiency, depends both on the mechanical properties of the foodand on chewing dynamics. These aspects have rarely been studied in combination and/or at the intraspecificlevel. Here we applied 3D dental surface texture analysis to a sample of field voles (Microtusagrestis) trapped from Finnish Lapland at different seasons and localities to test for inter-populationvariations. We also explored intra-individual variation in chewing dynamics by analysing two facetson the second upper molars. Our results confirm that the two localities have similar environments andthat the voles feed on the same items there. On the other hand, the texture data suggest that diets areseasonally variable, probably due to varying concentrations of abrasives. Lastly, the textures on thebuccal facets are more isotropic and their direction deviates more from the mesial chewing directionthan the lingual facets. We interpret these results as reflecting food, rather than chewing, movements,where food particles are more guided on the lingual side of the molars. This has implications for theapplication of dental microwear analysis to fossils: only homologous facets can be compared, evenwhen the molar row seems to constitute a functional unit

Forêts de montagne et changement climatique : impacts et adaptation

This review identifies the main impacts of climate change on mountain forests, mainly in Europe, and the management practices proposed for forest adaption. The rise in temperatures, more frequent droughts and the multiplication of extreme events should lead, especially below 1000m in altitude, to the disappearance of highly drought-intolerant tree species (spruce, Scots pine) and their replacement by deciduous trees. In addition, recruitment of some species (fir, beech) is observed at higher altitudes and the duration of the growing season is increasing. Management recommendations for forest adaptation to climate change focus on reducing tree species' vulnerability to water stress and pests, as well as increasing their resilience and ability to respond to extreme weather events. They require genetic improvements and practices that encourage the establishment of suitable species, reduce water consumption and reduce the exposure of stands to risk.Les impacts du changement climatique sur les forêts de montagne sont déjà perceptibles et les prévisions nous montrent, par leurs contradictions, la complexité des phénomènes en jeu. L'objectif de cette étude bibliographique est d'abord de caractériser les principaux effets du changement climatique, principalement dans les forêts alpines, puis de présenter différentes options d'adaptation devant permettre de conserver les services actuellement fournis par la forêt. L'épicéa, le sapin et le hêtre, dominants dans les Alpes françaises, y sont privilégiés

Forêts de montagne et changement climatique : impacts et adaptations

This review identifies the main impacts of climate change on mountain forests, mainly in Europe, and the management practices proposed for forest adaption. The rise in temperatures, more frequent droughts and the multiplication of extreme events should lead, especially below 1000m in altitude, to the disappearance of highly drought-intolerant tree species (spruce, Scots pine) and their replacement by deciduous trees. In addition, recruitment of some species (fir, beech) is observed at higher altitudes and the duration of the growing season is increasing. Management recommendations for forest adaptation to climate change focus on reducing tree species' vulnerability to water stress and pests, as well as increasing their resilience and ability to respond to extreme weather events. They require genetic improvements and practices that encourage the establishment of suitable species, reduce water consumption and reduce the exposure of stands to risk.Cette étude bibliographique recense les principaux impacts du changement climatique sur les forêts de montagne, principalement européennes, ainsi que les pratiques de gestion proposées pour adapter les forêts à ces changements. La hausse des températures, les sécheresses plus fréquentes et la multiplication des évènements extrêmes devraient entrainer, surtout en-deçà de 1000m d'altitude, une réduction des essences les moins tolérantes à la sécheresse (épicéa, pin sylvestre) et leur remplacement par des feuillus. D'ores et déjà, le recrutement de certaines essences (sapin, hêtre) est observé à des altitudes plus élevées et la durée de la saison de végétation augmente. Les préconisations de gestion pour l'adaptation des forêts au changement climatique s'attachent à réduire la vulnérabilité des essences au stress hydrique et aux parasites, ainsi qu'à renforcer leur résilience et leur capacité de réponse aux évènements climatiques extrêmes. Elles passent par des améliorations génétiques et des pratiques qui favorisent l'installation d'espèces adaptées, réduisent la consommation d'eau et l'exposition des peuplements aux risques

Correspondence between the 3-form and non-minimal multiplet in supersymmetry

In analogy to the chiral-linear multiplet correspondence we establish a relationship between the 3-form (or gaugino condensate) multiplet and a coupled non-minimal (0,1/2) multiplet, illustrated by a simple explicit example.Comment: 10 page

Disruption of PHF21A causes syndromic intellectual disability with craniofacial anomalies, epilepsy, hypotonia, and neurobehavioral problems including autism

BACKGROUND: PHF21A has been associated with intellectual disability and craniofacial anomalies based on its deletion in the Potocki-Shaffer syndrome region at 11p11.2 and its disruption in three patients with balanced translocations. In addition, three patients with de novo truncating mutations in PHF21A were reported recently. Here, we analyze genomic data from seven unrelated individuals with mutations in PHF21A and provide detailed clinical descriptions, further expanding the phenotype associated with PHF21A haploinsufficiency. METHODS: Diagnostic trio whole exome sequencing, Sanger sequencing, use of GeneMatcher, targeted gene panel sequencing, and MiSeq sequencing techniques were used to identify and confirm variants. RT-qPCR was used to measure the normal expression pattern of PHF21A in multiple human tissues including 13 different brain tissues. Protein-DNA modeling was performed to substantiate the pathogenicity of the missense mutation. RESULTS: We have identified seven heterozygous coding mutations, among which six are de novo (not maternal in one). Mutations include four frameshifts, one nonsense mutation in two patients, and one heterozygous missense mutation in the AT Hook domain, predicted to be deleterious and likely to cause loss of PHF21A function. We also found a new C-terminal domain composed of an intrinsically disordered region. This domain is truncated in six patients and thus likely to play an important role in the function of PHF21A, suggesting that haploinsufficiency is the likely underlying mechanism in the phenotype of seven patients. Our results extend the phenotypic spectrum of PHF21A mutations by adding autism spectrum disorder, epilepsy, hypotonia, and neurobehavioral problems. Furthermore, PHF21A is highly expressed in the human fetal brain, which is consistent with the neurodevelopmental phenotype. CONCLUSION: Deleterious nonsense, frameshift, and missense mutations disrupting the AT Hook domain and/or an intrinsically disordered region in PHF21A were found to be associated with autism spectrum disorder, epilepsy, hypotonia, neurobehavioral problems, tapering fingers, clinodactyly, and syndactyly, in addition to intellectual disability and craniofacial anomalies. This suggests that PHF21A is involved in autism spectrum disorder and intellectual disability, and its haploinsufficiency causes a diverse neurological phenotype

Activation of FGF Signaling Mediates Proliferative and Osteogenic Differences between Neural Crest Derived Frontal and Mesoderm Parietal Derived Bone

BACKGROUND: As a culmination of efforts over the last years, our knowledge of the embryonic origins of the mammalian frontal and parietal cranial bones is unambiguous. Progenitor cells that subsequently give rise to frontal bone are of neural crest origin, while parietal bone progenitors arise from paraxial mesoderm. Given the unique qualities of neural crest cells and the clear delineation of the embryonic origins of the calvarial bones, we sought to determine whether mouse neural crest derived frontal bone differs in biology from mesoderm derived parietal bone. METHODS: BrdU incorporation, immunoblotting and osteogenic differentiation assays were performed to investigate the proliferative rate and osteogenic potential of embryonic and postnatal osteoblasts derived from mouse frontal and parietal bones. Co-culture experiments and treatment with conditioned medium harvested from both types of osteoblasts were performed to investigate potential interactions between the two different tissue origin osteoblasts. Immunoblotting techniques were used to investigate the endogenous level of FGF-2 and the activation of three major FGF signaling pathways. Knockdown of FGF Receptor 1 (FgfR1) was employed to inactivate the FGF signaling. RESULTS: Our results demonstrated that striking differences in cell proliferation and osteogenic differentiation between the frontal and parietal bone can be detected already at embryonic stages. The greater proliferation rate, as well as osteogenic capacity of frontal bone derived osteoblasts, were paralleled by an elevated level of FGF-2 protein synthesis. Moreover, an enhanced activation of FGF-signaling pathways was observed in frontal bone derived osteoblasts. Finally, the greater osteogenic potential of frontal derived osteoblasts was dramatically impaired by knocking down FgfR1. CONCLUSIONS: Osteoblasts from mouse neural crest derived frontal bone displayed a greater proliferative and osteogenic potential and endogenous enhanced activation of FGF signaling compared to osteoblasts from mesoderm derived parietal bone. FGF signaling plays a key role in determining biological differences between the two types of osteoblasts