From microbes to mammals: Pond biodiversity homogenization across different land-use types in an agricultural landscape

Local biodiversity patterns are expected to strongly reflect variation in topography, land use, dispersal boundaries, nutrient supplies, contaminant spread, management practices, and other anthropogenic influences. Contrary to this expectation, studies focusing on specific taxa revealed a biodiversity homogenization effect in areas subjected to long-term intensive industrial agriculture. We investigated whether land use affects biodiversity levels and community composition (α- and β-diversity) in 67 kettle holes (KH) representing small aquatic islands embedded in the patchwork matrix of a largely agricultural landscape comprising grassland, forest, and arable fields. These KH, similar to millions of standing water bodies of glacial origin, spread across northern Europe, Asia, and North America, are physico-chemically diverse and differ in the degree of coupling with their surroundings. We assessed aquatic and sediment biodiversity patterns of eukaryotes, Bacteria, and Archaea in relation to environmental features of the KH, using deep-amplicon-sequencing of environmental DNA (eDNA). First, we asked whether deep sequencing of eDNA provides a representative picture of KH aquatic biodiversity across the Bacteria, Archaea, and eukaryotes. Second, we investigated if and to what extent KH biodiversity is influenced by the surrounding land use. We hypothesized that richness and community composition will greatly differ in KH from agricultural land use compared with KH in grasslands and forests. Our data show that deep eDNA amplicon sequencing is useful for in-depth assessments of cross-domain biodiversity comprising both micro- and macro-organisms, but has limitations with respect to single-taxa conservation studies. Using this broad method, we show that sediment eDNA, integrating several years to decades, depicts the history of agricultural land-use intensification. Aquatic biodiversity was best explained by seasonality, whereas land-use type explained little of the variation. We concluded that, counter to our hypothesis, land use intensification coupled with landscape wide nutrient enrichment (including atmospheric deposition), groundwater connectivity between KH and organismal (active and passive) dispersal in the tight network of ponds, resulted in a biodiversity homogenization in the KH water, leveling off today's detectable differences in KH biodiversity between land-use types. These findings have profound implications for measures and management strategies to combat current biodiversity loss in agricultural landscapes worldwide

Importance of ion energy on SEU in CMOS SRAMs

The single-event upset (SEU) responses of 16 Kbit to 1 Mbit SRAMs irradiated with low and high-energy heavy ions are reported. Standard low-energy heavy ion tests appear to be sufficiently conservative for technologies down to 0.5 {micro}m

Interactions entre l'avifaune sauvage et les élevages de volailles : quel risque épidémiologique vis à vis de l'Influenza aviaire ?

Textes issus des travaux du programme Casdar "Innovation et Partenariat" de 2007 et présentés lors d'un colloque le 4 décembre 2012, sous l'égide du GIS Relance AgronomiqueNational audienceThe outbreak of highly pathogenic avian Influenza that has spread to the territories of Western Europe in 2006 generated questions about the risks of contact between wild birds and poultry that have access to an outdoor trail. Within this framework, the birds likely to attend the courses of poultry as well as their surroundings were characterized on the territories of the Dombes, Bresse, the Pays de la Loire and the Landes with standard observation protocols. Specific monitoring of the movements of Mallard, species the AI tank, has been implemented. At the end of this study, certain factors increasing or decreasing the risk of exposure of poultry to the virus have been highlighted. Furthermore, the mallard duck does not appear to come into contact with poultry. The question arose on the role of birds frequenting both ponds and farms, which can be an intermediary between mallard ducks and poultry.L’épizootie d’Influenza aviaire hautement pathogène qui s’est propagée aux territoires d’Europe occidentale en 2006 a engendré des questionnements quant aux risques de contacts entre l’avifaune sauvage et les volailles qui ont accès à un parcours extérieur. Dans ce cadre, l’avifaune susceptible de fréquenter les parcours de volailles ainsi que leurs abords a été caractérisée sur les territoires de la Dombes, de la Bresse, des Pays de Loire et des Landes à partir de protocoles d’observation standards. Un suivi spécifique des mouvements du canard colvert, espèce réservoir des Influenzas, a été mis en place. A l’issue de cette étude, certains facteurs d’augmentation ou de diminution du risque d’exposition des volailles au virus ont été mis en évidence. Par ailleurs, le canard colvert ne semble pas entrer en contact avec les volailles. La question se pose alors du rôle des oiseaux fréquentant à la fois les étangs et les élevages, pouvant être un intermédiaire entre le canard colvert et les volailles

Interactions entre l'avifaune sauvage et les élevages de volailles : quel risque épidémiologique vis à vis de l'Influenza aviaire ?

L’épizootie d’Influenza aviaire hautement pathogène qui s’est propagée aux territoires d’Europe occidentale en 2006 a engendré des questionnements quant aux risques de contacts entre l’avifaune sauvage et les volailles qui ont accès à un parcours extérieur. Dans ce cadre, l’avifaune susceptible de fréquenter les parcours de volailles ainsi que leurs abords a été caractérisée sur les territoires de la Dombes, de la Bresse, des Pays de Loire et des Landes à partir de protocoles d’observation standards. Un suivi spécifique des mouvements du canard colvert, espèce réservoir des Influenzas, a été mis en place. A l’issue de cette étude, certains facteurs d’augmentation ou de diminution du risque d’exposition des volailles au virus ont été mis en évidence. Par ailleurs, le canard colvert ne semble pas entrer en contact avec les volailles. La question se pose alors du rôle des oiseaux fréquentant à la fois les étangs et les élevages, pouvant être un intermédiaire entre le canard colvert et les volailles.The outbreak of highly pathogenic avian Influenza that has spread to the territories of Western Europe in 2006 generated questions about the risks of contact between wild birds and poultry that have access to an outdoor trail. Within this framework, the birds likely to attend the courses of poultry as well as their surroundings were characterized on the territories of the Dombes, Bresse, the Pays de la Loire and the Landes with standard observation protocols. Specific monitoring of the movements of Mallard, species the AI tank, has been implemented. At the end of this study, certain factors increasing or decreasing the risk of exposure of poultry to the virus have been highlighted. Furthermore, the mallard duck does not appear to come into contact with poultry. The question arose on the role of birds frequenting both ponds and farms, which can be an intermediary between mallard ducks and poultry

Worst-Case Bias During Total Dose Irradiation of SOI Transistors

The worst case bias during total dose irradiation of partially depleted SOI transistors (from SNL and from CEA/LETI) is correlated to the device architecture. Experiments and simulations are used to analyze SOI back transistor threshold voltage shift and charge trapping in the buried oxide

Worst-Case Bias During Total Dose Irradiation of SOI Transistors

The worst case bias during total dose irradiation of partially depleted SOI transistors (from SNL and from CEA/LETI) is correlated to the device architecture. Experiments and simulations are used to analyze SOI back transistor threshold voltage shift and charge trapping in the buried oxide

Monocotyledonous plants graft at the embryonic root–shoot interface

Grafting is possible in both animals and plants. Although in animals the process requires surgery and is often associated with rejection of non-self, in plants grafting is widespread, and has been used since antiquity for crop improvement1. However, in the monocotyledons, which represent the second largest group of terrestrial plants and include many staple crops, the absence of vascular cambium is thought to preclude grafting2. Here we show that the embryonic hypocotyl allows intra- and inter-specific grafting in all three monocotyledon groups: the commelinids, lilioids and alismatids. We show functional graft unions through histology, application of exogenous fluorescent dyes, complementation assays for movement of endogenous hormones, and growth of plants to maturity. Expression profiling identifies genes that unify the molecular response associated with grafting in monocotyledons and dicotyledons, but also gene families that have not previously been associated with tissue union. Fusion of susceptible wheat scions to oat rootstocks confers resistance to the soil-borne pathogen Gaeumannomyces graminis. Collectively, these data overturn the consensus that monocotyledons cannot form graft unions, and identify the hypocotyl (mesocotyl in grasses) as a meristematic tissue that allows this process. We conclude that graft compatibility is a shared ability among seed-bearing plants

Monocotyledonous plants graft at the embryonic root-shoot interface.

Grafting is possible in both animals and plants. Although in animals the process requires surgery and is often associated with rejection of non-self, in plants grafting is widespread, and has been used since antiquity for crop improvement1. However, in the monocotyledons, which represent the second largest group of terrestrial plants and include many staple crops, the absence of vascular cambium is thought to preclude grafting2. Here we show that the embryonic hypocotyl allows intra- and inter-specific grafting in all three monocotyledon groups: the commelinids, lilioids and alismatids. We show functional graft unions through histology, application of exogenous fluorescent dyes, complementation assays for movement of endogenous hormones, and growth of plants to maturity. Expression profiling identifies genes that unify the molecular response associated with grafting in monocotyledons and dicotyledons, but also gene families that have not previously been associated with tissue union. Fusion of susceptible wheat scions to oat rootstocks confers resistance to the soil-borne pathogen Gaeumannomyces graminis. Collectively, these data overturn the consensus that monocotyledons cannot form graft unions, and identify the hypocotyl (mesocotyl in grasses) as a meristematic tissue that allows this process. We conclude that graft compatibility is a shared ability among seed-bearing plants.BBSRC (BB/P003117/1) European Research Council Gates PhD scholarships Ceres Agrictech fun