738 research outputs found
Pilot Lt. Geraud Sitting in a SPAD Spa 65
No full textLt. Geraud in flight gear sitting in the cockpit of his SPAD. Image displayed (72 dpi JPEG), Master image (600 dpi TIFF)
Sparse multiple kernel learning: Support identification via mirror stratifiability
No full textIn statistical machine learning, kernel methods allow to consider infinite dimensional feature spaces with a computational cost that only depends on the number of observations. This is usually done by solving an optimization problem depending on a data fit term and a suitable regularizer. In this paper we consider feature maps which are the concatenation of a fixed, possibly large, set of simpler feature maps. The penalty is a sparsity inducing one, promoting solutions depending only on a small subset of the features. The group lasso problem is a special case of this more general setting. We show that one of the most popular optimization algorithms to solve the regularized objective function, the forward-backward splitting method, allows to perform feature selection in a stable manner. In particular, we prove that the set of relevant features is identified by the algorithm after a finite number of iterations if a suitable qualification condition holds. Our analysis rely on the notions of stratification and mirror stratifiability
The role of initial soil conditions in shallow landslide triggering. Insights from physically based approaches
No full textIn the last years, the shallow landslide phenomenon has increasingly been investigated through physically based models, which try to extend over large-area simplified slope stability analyses using physical and mechanical parameters of the involved material. However, the parameterization of such models is usually challenging even at the slope scale, due to the numerous parameters involved in the failure mechanism. In particular, considering the scale of the phenomenon, the role of transient hydrology is essential. For this reason, in this work we present the outcome of different experimental tests conducted on a soil slope model with a sloping flume. The tested material was sampled on Monte Mario Hill (Rome, Central Italy), an area which has been frequently affected by rainfall-induced landslide events in the past. In this respect, we also performed a physically based numerical analysis at the field conditions, in order to evaluate the response of the terrain to a recent extreme rainfall event. The results of the flume tests show that, for the same material, two different triggering mechanisms (i.e., uprise of a temporary water table and advance of the wetting front) occur by varying the initial water content only. At the same time, the results of the numerical simulations indicate that clayey sand and lean clay are the soil types mostly influenced by the abovementioned rainfall event, since the initial moisture conditions enhance the formation of a wide wetting front within the soil profile
First report ofPotato yellow mosaic virusinfectingSolanum americanumin Venezuela
No full textPotato yellow mosaic virus (PYMV) is one of the most important tomato begomoviruses in the Caribbean basin (Morales et al., 2006). In Venezuela, a recent survey showed that PYMV is the most widespread and prevalent begomovirus in tomato fields (Geraud-Pouey et al., 2016). However, little is known about natural reservoirs of the virus. In 2007 and 2008 PYMV surveys were performed in several Venezuelan tomato fields and weeds in the genus Solanum showing virus-like symptoms were also collected (Fig. 1). As summarised in Table 1, nine leaf samples from solanaceous weeds were tested using PCR with PYMV-specific primers (Geraud-Pouey et al., 2016). PYMV infection was detected in two plants each of Solanum americanum and S. pimpinellifolium. Solanum pimpinellifolium is considered a host of PYMV (Boissot et al., 2008). However, S. americanum has not been found previously to be infected by this begomovirus. Hence, the complete sequence of DNA-A of PYMV isolates from the two S. americanum plants (herafter, Tachira-949 and Lara-1203) were obtained by rolling circle-amplification (RCA) using ϕ29 DNA polymerase (TempliPhi kit, GE Healthcare, Germany). The RCA products were then digested with the endonuclease HindIII and inserted in pBluescript II (SK+) for cloning. The complete sequences of DNA-A of isolates Tachira-949 (2,597 bp) and Lara-1203 (2,596 bp) were deposited in GenBank under Accession Nos. KU665804 and KX389269, respectively. Blast analyses revealed that PYMV isolate (D00940) from Venezuela was the most closely related isolate to the isolates Tachira-949 and Lara-1203 showing 94 and 93% nucleotide identity, respectively. PYMV-like sequences in GenBank were retrieved to perform pairwise and phylogenetic analyses using Mega 6 (Tamura et al., 2013). Isolates Tachira-949 and Lara-1203 shared 96% nucleotide identity and they were most related phylogenetically to PYMV isolates from Central America and Venezuela (Fig. 2). Interestingly, the two PYMV-infected S. americanum plants were found in geographically distant tomato production zones of the country
Desarrollo y reproducci\uf3n de Capulinia sp. cercana a jaboticabae evon Ihering (Hemiptera: Eriococcidae) sobre guayabo
No full textCHIRINOS DT, GERAUD-POUEY F, ROMAY G. 2004. Development and
reproduction of Capulinia sp. near jaboticabae von Ihering
(Hemiptera: Eriococcidae) on Guava. Entomotropica 19(3): 135-142.
During January-October 1999 studies on the life history and the
fertility of Capulinia sp. were conducted. Duration of development, sex
ratio, fecundity (eggs/female) and adult longevity were evaluated. Eggs
hatched after 8 days. The female undergoes two and the male four
nymphal instars. First instar nymphs lasted 8.48\ub10.03 days. The
duration of the female second nymphal instar and the longevity of the
adult were 6.05\ub10.03 y 46.67\ub10.61 days respectively. The male
second, third and forth nymphal instars as well as the longevity of the
adult were 4.57\ub10.02, 2.04\ub10.01, 3.66\ub10.02,
1.10\ub10.01 days respectively. The sex ratio resulted of 1:1. The
fecundity was 2511.94\ub157.20 eggs/female. The high fecundity
explains the possibilities of developing large populations like those
observed in orchards during the initial colonization by this insect.
The life history are basic for understanding entomological problem
especially for species like Capulinia sp. on guava.CHIRINOS DT, GERAUD-POUEY F, ROMAY G. 2004. Desarrollo y
reproducci\uf3n de Capulinia sp. cercana a jaboticabae von Ihering
(Hemiptera: Eriococcidae) sobre Guayabo. Entomotropica 19(3): 135-142.
Durante el per\uedodo enero-octubre 1999 se realizaron estudios sobre
el ciclo biol\uf3gico y la fertilidad de Capulinia sp. sobre guayabo,
Psidium guajava L.. Se evalu\uf3 la duraci\uf3n del desarrollo,
la proporci\uf3n de sexos, la fecundidad de la hembra (huevos/hembra)
y la longevidad de adultos (d\uedas). Los huevos duraron 8,00
d\uedas. La hembra pasa por dos estadios ninfales y el macho por
cuatro. La ninfa del primer estad\uedo dur\uf3 8,48\ub10,03
d\uedas.Para hembras,la duraci\uf3n del segundo estad\uedo y la
longevidad del adulto fueron de 6,05\ub10,03 y 46,67\ub10,61
d\uedas,respectivamente.En machos las duraciones del segundo, tercer,
cuarto estad\uedo y longevidad del adulto fueron de 4,57\ub10,02,
2,04\ub10,01, 3,66\ub10,02, 1,10\ub10,01d\uedas,
respectivamente. La proporci\uf3n de sexos result\uf3 de
aproximadamente 1:1. La fecundidad fue de 2511,94\ub157,20
huevos/hembra. Esta alta fecundidad explica las posibilidades de
desarrollar grandes poblaciones tales como las observadas en huertos
durante el inicio de las colonizaciones por este insecto. Los estudios
de biolog\ueda permiten comprender los problemas entomol\uf3gicos,
especialmente en el caso de especies como Capulinia sp. sobre guayabo
Efecto físico de las exfoliaciones de la corteza del guayabo (Psidium guajava) sobre Capulinia sp. cercana a jaboticabae von Ihering (Hemiptera: Eriococcidae)
No full textGERAUD-POUEY F, CHIRINOS DT, ROMAY G. 2001. Physical effect of
exfoliation of guava tree bark on Capulinia sp. near to
jaboticabae von Ihering (Hemiptera: Eriococcidae). Entomotropica Vol
16(1):21-27. Since it appeared in Venezuela in early 1993 the guava
cottony scale, Capulinia sp. has become the greatest entomological
problem on guava trees, Psidium guajava L. However in the
field, trees with smooth bark (with little or without exfoliations)
tend to be much less infested by this insect. Therefore, during
May-July 1999 the physical effect of bark exfoliations on the
establishment, survival and development of Capulinia sp. was assessed,
in the laboratory. Three host plant /Criolla oja local selecction)
conditions were included: with natural exfoliations, with bark
mechanically smoothed (smooth bark) and exfoliations substituted by
pieces of absorbent paper adhered to the smoothed bark (artificial
exfoliations). Survival of first instar nymphs (crawlers) was
significantly increased (>70%, P< 0.05) by the presence of
exfoliations (natural and artificial) as places under which they settle
down to feed. However, duration of development was little affected by
the existence of exfoliations. Bark smoothness could constitute a
source of resistance of guava plants to diminish the incidence and
damages by Capulinia sp
Desarrollo y reproducción de Capulinia sp. cercana a jaboticabae von Ihering (Hemiptera: Eriococcidae) sobre guayabo
No full textCHIRINOS DT, GERAUD-POUEY F, ROMAY G. 2004. Development and
reproduction of Capulinia sp. near jaboticabae von Ihering
(Hemiptera: Eriococcidae) on Guava. Entomotropica 19(3): 135-142.
During January-October 1999 studies on the life history and the
fertility of Capulinia sp. were conducted. Duration of development, sex
ratio, fecundity (eggs/female) and adult longevity were evaluated. Eggs
hatched after 8 days. The female undergoes two and the male four
nymphal instars. First instar nymphs lasted 8.48±0.03 days. The
duration of the female second nymphal instar and the longevity of the
adult were 6.05±0.03 y 46.67±0.61 days respectively. The male
second, third and forth nymphal instars as well as the longevity of the
adult were 4.57±0.02, 2.04±0.01, 3.66±0.02,
1.10±0.01 days respectively. The sex ratio resulted of 1:1. The
fecundity was 2511.94±57.20 eggs/female. The high fecundity
explains the possibilities of developing large populations like those
observed in orchards during the initial colonization by this insect.
The life history are basic for understanding entomological problem
especially for species like Capulinia sp. on guava
Efecto físico de las exfoliaciones de la corteza del guayabo (Psidium guajava) sobre Capulinia sp. cercana a jaboticabae von Ihering (Hemiptera: Eriococcidae)
No full textGERAUD-POUEY F, CHIRINOS DT, ROMAY G. 2001. Physical effect of
exfoliation of guava tree bark on Capulinia sp. near to
jaboticabae von Ihering (Hemiptera: Eriococcidae). Entomotropica Vol
16(1):21-27. Since it appeared in Venezuela in early 1993 the guava
cottony scale, Capulinia sp. has become the greatest entomological
problem on guava trees, Psidium guajava L. However in the
field, trees with smooth bark (with little or without exfoliations)
tend to be much less infested by this insect. Therefore, during
May-July 1999 the physical effect of bark exfoliations on the
establishment, survival and development of Capulinia sp. was assessed,
in the laboratory. Three host plant /Criolla oja local selecction)
conditions were included: with natural exfoliations, with bark
mechanically smoothed (smooth bark) and exfoliations substituted by
pieces of absorbent paper adhered to the smoothed bark (artificial
exfoliations). Survival of first instar nymphs (crawlers) was
significantly increased (>70%, P< 0.05) by the presence of
exfoliations (natural and artificial) as places under which they settle
down to feed. However, duration of development was little affected by
the existence of exfoliations. Bark smoothness could constitute a
source of resistance of guava plants to diminish the incidence and
damages by Capulinia sp
Pilgrimage churches of eastern Aquitaine and Liturgical Sculpture. The example of Saint-Geraud abbey and it chancel screen (Aurillac,Cantal - 11/12th centuries)
No full textInternational audienceAt the western borders of Auvergne, the Saint-Geraud abbey of Aurillac (Cantal) found at the end of the 9th century shows up for the Romanesque period the existence of an important but scattered building decor. For a long time focused on specifics pieces as capitals some liturgicalselements were misunderstood by the historiography. In the Romanesques sculptures Corpus of the monastery (11-beginning of the 13th century) could be found some elements came out from liturgicals screens : plates and pilar fragment. Made at the end of the 11th century thosecarved elements permit a better understanding of the liturgicals installations in the pilgrimage churches. As large it is, the pilgrimage church should make choices to set up circulation spaces. The choir enclosure is one of the mains solutions. First goal wished, to separate the monk and the layman but also to preserve for the both the virtus of the saint, here Gerald of Aurillac. Several points should be questioned. How the saint Géraud cult have impacted the Aurillac abbey church ? Those liturgical screens are chancel plates or differents and more recents pluteum ?Moreover, those liturgicals sculptures shows up decoratives formulas of the western Auvergne, a testimony of ornemental choices which are present in all the territories of the feodal Aquitaine of the 11th and 12th centuries. With their wilds beasts representations and smooth leaves, its appears linked to the sculpture of others monasteries of the French Massif Central (Menat, Limoges) but also more distant as the Poitou churches. To these decorative criterias, could be add the dimensions and material characteristics which are others elements to consider to having datations. A third and last element of a Romanesque chancel screen is the top of pilar fragment. Covered on two faces by cross pattées it seems to belong to other screen structure, probably also from another church which is contain in the walls of the monastery as Saint-Clement. Those pieces could permit a better understanding of the liturgical spaces and also ornamental choices for this important Saint-Geraud abbey at the eastern borders of Duchy of Aquitaine, a step on the Santiago road
Evaluación de Metaphycus sp. (Hymenoptera: Encyrtidae) como agente de control natural de Capulinia sp. cercana a jaboticabae von Ihering (Hemiptera: Eriococcidae)
No full textGeraud-Pouey F, Chirinos DT, Aguirre R, Bravo Y, Quintero JA. 2001.
Evaluation of Metaphycus sp. (Hymenoptera: Encyrtidae) as
agent of natural control of Capulinia sp. near of jaboticabae
von Ihering (Hemiptera: Eriococcidae). Entomotropica 16(3):165-171. In
Venezuela, since its appearance in 1993, Capulinia sp. is the most
destructive pest on guava (Psidium guajava L.). By early 1996
parasitism for Metaphycus sp. was detected. To evaluate its effect
during March-May 1999 an assay under field conditions was conducted in
Mara County, State of Zulia, Venezuela. Utilizing exclusion techniques,
the treatments were evaluated: T1, guava branches completely exposed,
T2, branches closed into organza cages and T3, branches into organza
cages impregnated with insecticide. The populations of Capulinia were
counted and the percentage of parasitism was estimated (expressed as
parasitized female on female total). On T1, parasitism resulted highest
(100%, P<0.05), observing lower population mean (12.70 individual),
whereas on T3, Capulinia reached its population maxim levels (200.5
individual) detecting 39.66% of parasitism. Thus, Metaphycus sp.
resulted an important regulator factor on Capulinia populations during
this period
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