Search results for "Hopper"
showing 10 items of 49 documents
The Inner Border: Edward Hopper’s Reimagining the Frontier
2020
International audience
An optical device for ultra-cold neutrons - Investigation of systematic effects and applications
2010
We developed an optical device for ultra-cold neutrons and investigated the influence of a tilt of its guiding components. A measurement of the time-of-flight of the neutrons through the device by means of a dedicated chopper system was performed and a light-optical method for the alignment of the guiding components is demonstrated. A comparative analysis of former experiments with our results shows the potential of such a device to test the electrical neutrality of the free neutron on the $10^{-22} q_{\rm e}$ level and to investigate the interaction of neutrons with gravity.
La écfrasis pictórica en la poesía de Irene Sánchez Carrón
2008
En este artículo se desarrolla el análisis comparado de dos poemas de Irene Sánchez Carrón, titulados “Después del baño, mujer secándose” (del libro Porque no somos dioses, Premio de Poesía Hermanos Argensola de 1997) y “Habitación de hotel. 1931” (de Escenas principales de un actor secundario, Premio de Poesía Adonais de 1999), que tienen en común su carácter de ejercicio ecfrástico. Asimismo, se analizan las fuentes pictóricas de Edgar Degas y Edward Hopper que aparecen en la génesis de los poemas. El comentario exhaustivo de las obras ayudará a ilustrar el viejo problema, planteado al menos desde Lessing, de los medios, los modos y los objetos con que literatura, por un lado, y artes plá…
The syndrome "basses richesses" of sugar beet in France is associated with different pathogen types and insect vectors
2007
International audience; The syndrome “basses richesses” (SBR) of sugar beet in France is associated with two phloem-restricted uncultivable bacteria: a stolbur phytoplasma and a y-3 proteobacteria. The known vector of proteobacteria is a cixiid planthopper, Pentastiridius leporinus (Hemiptera Cixiidae), formerly shown to transmit both the prokaryotes. The role of P. leporinus and of two other planthopper species, Cixius wagneri and Hyalesthes obsoletus, in spreading the two pathogens to sugar beet were compared and quantified. Because of its abundance and high infection rates with proteobacterium, P. leporinus was confirmed to be the economic vector of SBR disease. P. leporinus and C. wagne…
Norisoprenoids from Centaurea aspera and C. salmantica
1993
Abstract From aerial parts of Centaurea aspera var. subinermis a new homoderivative of the grasshopper ketone has been isolated. Its structure was deter
Dorsthippus and Aethiopiacris: synonymic genera of Dwarf Grasshoppers of the Ethiopian highlands (Orthoptera: Acrididae)
2020
The grasshopper species of the genera Dorsthippus Donskoff, 1977 (D. baleensis) and Aethiopiacris La Greca, 1994 (A. parva) of the Ethiopian highlands are very poorly known. Little information is a...
Association with the Syndrome "Basses Richesses" of Sugar Beet of a Phytoplasma and a Bacterium-Like Organism Transmitted by a Pentastiridius sp.
2002
The syndrome “basses richesses” of sugar beet (SBR) was first observed in 1991 in Burgundy, France. A cixiid planthopper, Pentastiridius beieri, has been proved to be involved in the transmission to sugar beet of a stolbur phytoplasma, which could be detected in some affected plants. In 2000, periwinkle and sugar beet exposed to field-collected cixiids developed symptoms similar to SBR on sugar beet. Use of 4′-6-diamidino-2-phenylindole (DAPI) staining and transmission electron microscopy confirmed the presence of phytoplasma in some of the plants, which were also positive for this pathogen in a polymerase chain reaction (PCR) analysis. A phloem-restricted gram-negative bacteria was seen i…
Pyrgomorphid grasshoppers of the genus Phymateus contain species-specific decapeptides of the AKH/RPCH family regulating lipid-mobilization during fl…
1996
. Using heterologous and conspecific bioassays, two peptides have been isolated from methanolic extracts of corpora cardiaca from the pyrgomorphid grasshopper Phymateus morbillosus L.The structures of both peptides were elucidated by a combination of Edman degradation, after deblocking the N-terminal pyroglutamic acid residue, and mass spectrometric techniques.One peptide is an octapeptide (pGlu-Leu-Asn-Phe-Ser-Thr-Gly-TrpNH2) which also occurs in other insects and is code-named Scg-AKH-II.The second peptide is a novel decapeptide member of the AKH/RPCH family (pGlu-Leu-Asn-Phe-Thr-Pro-Asn-Trp-Gly-SerNH2 code-named here Phm-AKH.It is the first example of a different peptide in the same genu…
Population structure and incidence of the stolbur phytoplasma vectorHyalesthes obsoletus(Cixiidae) among geographic regions in Switzerland
2013
The dissemination of stolbur phytoplasma (16Sr-XIIA group)-induced yellows diseases depends on the dispersal biology and host plant fidelity of the planthopper vector Hyalesthes obsoletus (Hemiptera: Cixiidae). We analysed the degree of these two properties in H. obsoletus by studying its population genetic structure and stolbur infection rates relative to the two major host plants, Convolvolus arvensis and Urtica dioica, in order to infer relevant divisions for stolbur epidemiology in Swiss viticultural regions. Three regional populations with the potential to determine stolbur epidemiology in distinct ways were identified. First, populations associated with U. dioica in northern Switzerla…
Origin of a sudden mass occurrence of the stolbur phytoplasma vectorHyalesthes obsoletus(Cixiidae) in Austria
2014
The grapevine disease ‘bois noir’ is widespread in European viticulture, but in many regions there is a lack of correspondence between disease spread and abundance of the main insect vector, the planthopper Hyalesthes obsoletus. This was the situation in Austria until 2012, when a mass occurrence of the vector was observed on Urtica dioica, a new host plant for the vector and reservoir plant for the pathogen, stolbur phytoplasma, in this area. Here we analyse the origin of the Austrian vector populations using genetic markers. The origin was unambiguously assigned to two regional populations, and two causes for the population expansion: immigration of East Central European populations and l…