Many agricultural landscapes are characterized by a high degree of heterogeneity and fragmentation. Landscape ecology focuses on the influence habitat in space time ecological processes. epidemiology aims at applying concepts approaches originating from landscape to study pathogen dynamics scale. However, despite strong that properties may have spread plant diseases, has still received little attention pathologists. Some recent methodological technological progress provides new powerful...

Abstract The global observation of profiles the atmospheric wind speed is highest-priority unmet need for numerical weather prediction. Satellite Doppler lidar most promising candidate to meet requirements on profile observations with high vertical resolution, precision, and accuracy. European Space Agency (ESA) decided implement a mission called Atmospheric Dynamics Mission Aeolus (ADM-Aeolus) demonstrate potential technology expected impact forecasting. An airborne prototype instrument...

Plant viruses are submitted to narrow population bottlenecks both during infection of their hosts and horizontal transmission between host individuals. The size exerted on virus populations plant invasion has been estimated in a few pathosystems but is not addressed yet for transmission. Using competition aphid two Potato Y variants, one them being noninfectious equally transmissible, we obtained estimates the an insect-borne its We found that transmitted average 0.5-3.2 particles, which...

In order to select for quantitative plant resistance pathogens, high throughput approaches that can precisely quantify disease severity are needed. Automation and use of calibrated image analysis should provide more accurate, objective faster analyses than visual assessments. contrast conventional visible imaging, chlorophyll fluorescence imaging is not sensitive environmental light variations provides single-channel images prone a segmentation by simple thresholding approaches. Among the...

• The deployment of resistant crops often leads to the emergence resistance-breaking pathogens that suppress yield benefit provided by resistance. Here, we theoretically explored how farmers' main leverages (resistant cultivar choice, resistance strategy, landscape planning and cultural practices) can be best combined achieve durability while minimizing losses as a result plant viruses. Assuming gene-for-gene type interaction, virus epidemics are modelled in composed mosaic susceptible...

An understanding of the evolution pathogen quantitative traits in response to host selective pressures is essential for development durable management strategies resistant crops. However, we still lack experimental data on effects partial resistance multiple phenotypic (aggressiveness) and evolutionary pathogens. We performed a cross-inoculation experiment with four grapevine hosts 103 isolates downy mildew (Plasmopara viticola) sampled from susceptible partially varieties. analysed neutral...

A simulator (Wa-LiD) was developed to simulate the reflection of LiDAR waveforms from water across visible wavelengths. The specific features include 1) a geometrical representation surface properties; 2) use laws radiative transfer in adjusted for wavelength and water's physical 3) modeling detection noise signal level due solar radiation. set simulated compared with observed acquired by HawkEye airborne Geoscience Laser Altimeter System (GLAS) satellite systems near infrared or green...

Abstract. The acquisition of atmospheric wind profiles on a global scale was realized by the launch Aeolus satellite, carrying unique Atmospheric LAser Doppler INstrument (ALADIN), first lidar in space. One major component ALADIN is its high-power, ultraviolet (UV) laser transmitter, which based an injection-seeded, frequency-tripled Nd:YAG and fulfills set demanding requirements terms pulse energy, length, repetition rate, spatial spectral beam properties. In particular, frequency stability...

This work aimed to prospect future space-borne LiDAR sensor capacities for global bathymetry over inland and coastal waters. The performances were assessed using a methodology based on waveform simulation. A representative simulated database is first built from the Wa-LiD (Water LiDAR) simulator distributions of water parameters assumed be at scale. detection estimation process thus applied each determine bathymetric measurement probabilities in waters, shallow lakes, deep lakes rivers range...

Estimating forest canopy height from large-footprint satellite LiDAR waveforms is challenging given the complex interaction between waveforms, terrain, and vegetation, especially in dense tropical equatorial forests. In this study, French Guiana was estimated using multiple linear regression models Random Forest technique (RF). This analysis either based on waveform metrics extracted GLAS (Geoscience Laser Altimeter System) spaceborne data terrain information derived SRTM (Shuttle Radar...

The breakdown of plant virus resistance genes is a major issue in agriculture. We investigated whether set would last longer when stacked into single cultivar (pyramiding) or deployed individually regional mosaics (mosaic strategy). modeled the genetic and epidemiological processes shaping demogenetic dynamics viruses under multilocus gene-for-gene system, from to landscape scales. consisted many fields, was subject seasonality, reservoir hosting year-round. Strategy performance depended...

The management of genes conferring resistance to plant-pathogens should make it possible control epidemics (epidemiological perspective) and preserve durability (evolutionary perspective). Resistant susceptible cultivars must be strategically associated according the principles cultivar mixture (within a season) rotation (between seasons). We explored these questions by modeling evolutionary epidemiological processes shaping dynamics pathogen population in landscape composed seasonal...

Prediction of pathogen emergence is an important field research, both in human health and agronomy. Most studies have focused on the ecological or anthropic factors involved rather than role intrinsic properties. The capacity pathogens to infect a large set host species, i.e. possess range breadth (HRB), tightly linked their propensity. Using extensive plant virus database, we found that four traits related genome transmission properties were strongly robustly HRB. Broader ranges observed...

LiDAR data has been successfully used to estimate forest parameters such as canopy heights and biomass. Major limitation of systems (airborne spaceborne) arises from their limited spatial coverage. In this study, we present a technique for height mapping using airborne spaceborne (from the Geoscience Laser Altimeter System (GLAS)). First, extracted both were extrapolated available environmental data. The estimated maps Random Forest (RF) regression or GLAS calibration datasets showed similar...

Abstract Grapevine trunk diseases cause yield losses and vine mortality in vineyards worldwide. However, there have been few quantitative studies evaluating grapevine dieback on a large spatial temporal scale. Here, we consolidated standardized databases from the 13 main wine regions of France, compiling records leaf symptoms associated with esca Eutypa 2082 plots 36 cultivars over 20-year period. This dataset was used (a) for analysis prevalence (number at least one symptomatic plant)...

Grapevine downy mildew, caused by the oomycete Plasmopara viticola (P. viticola, Berk. & M. A. Curtis; Berl. De Toni), is a global threat to Eurasian wine grapes Vitis vinifera. Although resistant grapevine varieties are becoming more accessible, P. populations rapidly evolving overcome these resistances. We aimed uncover avirulence genes related Rpv3.1-mediated resistance. sequenced genomes and characterized development of 136 strains on sensitive cultivars. A genome-wide association study...

SUMMARY Understanding the factors driving pathogen emergence and re-emergence is a major challenge, particularly in agriculture, where use of resistant plant cultivars imposes strong selective pressures on populations leads frequently to 'resistance breakdown'. Presently, durable resistances are only identified after long period large-scale cultivation cultivars. We propose new predictor durability resistance. Because resistance breakdown involves modifications avirulence pathogens, we...

The effective size of populations (Ne) determines whether selection or genetic drift is the predominant force shaping their structure and evolution. Populations having high Ne adapt faster, as acts more intensely, than low Ne, where random effects dominate. Estimating for various steps plant virus life cycle has been focus several studies in last decade, but no estimates are available vertical transmission viruses, although seed economically significant at least 18% viruses one species. Here...

Uncovering how natural selection and genetic drift shape the evolutionary dynamics of virus populations within their hosts can pave way to a better understanding emergence. Mathematical models already play leading role in these studies are intended predict future emergences. Here, using high-throughput sequencing, we analyzed within-host population four Potato Y (PVY) variants differing at most by two substitutions involved pathogenicity properties. Model procedures were used compare...

ABSTRACT The invention of next-generation sequencing (NGS) techniques marked the coming a new era in detection genetic diversity intrahost viral populations. A good understanding structure these populations requires, first, ability to identify different isolates or variants and, second, accurately quantify them. However, initial amplification step NGS studies can impose potential quantitative biases, modifying variant relative frequencies. In particular, number target molecules (NTM) used...