Temporal study of natural populations of Heterorhabditid and Steinernematid nematodes in horticultural crop soils

La dynamique des populations de nématodes entomopathogènes dans des sols horticoles a été étudiée par des prélèvements mensuels en huit sites de Catalogne (nord-est de l'Espagne) pendant 14 mois. Ces nématodes entomopathogènes ont été détectés dans six des huit sites et ont continué à l'être quels qu'aient été les traitements agricoles pratiqués sur ces sites. Pendant cette étude, les sites ont été labourés, détruisant ainsi l'habitat naturel des nématodes, puis laissés en jachère pendant plusieurs mois, sans que la présence des nématodes n'en paraisse affectée. Cependant, une influence saisonnière peut être observée, la présence des nématodes étant plus faible pendant les mois d'été où la température est élevée. Cette influence saisonnière apparaît également affecter la répartition verticale des nématodes qui migrent vers les couches plus profondes du sol, vraisemblablement pour éviter les effets néfastes de la température et du manque d'humidité. Les résultats de cette étude montrent que les populations naturelles de nématodes entomopathogènes sont capables de persister et de survivre dans le sol pendant de longues périodes en s'adaptant aux conditions fluctuantes et adverses de leur habitat naturel. (Résumé d'auteur

Entanglement detection in coupled particle plasmons

When in close contact, plasmonic resonances interact and become strongly correlated. In this work we develop a quantum mechanical model, using the language of continuous variables and quantum information, for an array of coupled particle plasmons. This model predicts that when the coupling strength between plasmons approaches or surpasses the local dissipation, a sizable amount of entanglement is stored in the collective modes of the array. We also prove that entanglement manifests itself in far-field images of the plasmonic modes, through the statistics of the quadratures of the field, in what constitutes a novel family of entanglement witnesses. This protocol is so robust that it is indeed independent of whether our own model is correct. Finally, we estimate the amount of entanglement, the coupling strength and the correlation properties for a system that consists of two or more coupled nanospheres of silver, showing evidence that our predictions could be tested using present-day state-of-the-art technology.Comment: 8 pages (6 main text + 2 supplemental), 3 figure

The Configuration of a Fiscal-Type Municipal Treasury. The Case of Santa Cruz de Tenerife, 1850-1880

La pedanía de Santa Cruz de Tenerife accedió a la categoría de villa exenta en 1803, para luego adquirir el rango de capital provincial por el sistema político-administrativo propuesto por el régimen liberal. Por ello, el municipio debió constituir su hacienda de manera ex novo, aunque no consiguió disponer de los recursos económicos necesarios. Desde 1850, se creó una hacienda de carácter fiscal que hizo factible comenzar a dotar de bienes esenciales a la nueva urbe. Ello se vio acompañado de una mejora de sus actividades económicas, principalmente del comercio, el puerto e industrias asociadas. En el presente trabajo estudiaremos las transformaciones socioeconómicas que se produjeron a mediados del siglo xix, para luego adentrarnos en el análisis de la nueva configuración de la hacienda municipal.The district of Santa Cruz de Tenerife acceded to the category of villa exenta in 1803, to then acquire the rank of provincial capital by the political-administrative system proposed by the liberal regime. For this reason, the municipality had to establish its treasury ex novo, although it did not manage to have the necessary economic resources. From 1850, it had a fiscal-type municipal treasury for the provision of essential services required by the new city. This was accompanied by an improvement in their economic activities, mainly in the commerce, the port and its associated industries. In the present work we will study the socioeconomic transformations that took place in the middle of the xix century, to later get into the analysis of the new configuration of the municipal treasury

La letra de cambio: un instrumento de pago del donativo a la Hacienda Real en Canarias (s. XVII)

Los mecanismos de financiación de la deuda de la Hacienda castellana en el siglo XVII fueron insuficientes. Ello compelió a dicha institución a la búsqueda de nuevas fuentes de ingresos mediante cargas extraordinarias, y el donativo fue una de ellas. Sin embargo, la escasez de recursos indujo a la Corona a la búsqueda de otros medios, como la letra de cambio. Ésta brindaba la posibilidad de suministrar los pagos del donativo mediante el crédito que proporcionaba a los agentes que operaban con ella, como funcionarios reales, cargos públicos y mercaderes. Fueron estos últimos los intermediarios encargados de recabar el dinero en metálico en plazas de proyección internacional, en virtud de los acuerdos suscritos entre ellos en las letras emitidas. Así, la Corona se involucraba también en el crédito del Mundo Moderno.In the seventeenth century, the financial management of the Castilian debt forced the Treasury to look for new sources of income. The donativo was one of those extraordinary taxes. However, the insufficiency of cash induced the Crown to use other medium of payment, such us bill of exchange. The possibility of credit was achieved. Agents like government employees or merchants worked with it and they were the intermediaries in charge of collecting cash in international places. Therefore, the Castilian Crown entered into the credit lines of Modern World

Adaptation and therapeutic exploitation of the plasma membrane of African trypanosomes

African trypanosomes are highly divergent from their metazoan hosts, and as part of adaptation to a parasitic life style have developed a unique endomembrane system. The key virulence mechanism of many pathogens is successful immune evasion, to enable survival within a host, a feature that requires both genetic events and membrane transport mechanisms in African trypanosomes. Intracellular trafficking not only plays a role in immune evasion, but also in homeostasis of intracellular and extracellular compartments and interactions with the environment. Significantly, historical and recent work has unraveled some of the connections between these processes and highlighted how immune evasion mechanisms that are associated with adaptations to membrane trafficking may have, paradoxically, provided specific sensitivity to drugs. Here, we explore these advances in understanding the membrane composition of the trypanosome plasma membrane and organelles and provide a perspective for how transport could be exploited for therapeutic purposes

A Minor Dihydropyran Apocarotenoid from Mated Cultures of Blakeslea trispora

The heterocyclic C15 apocarotenoid 1 was isolated from mated cultures of the strains F986 (+) and F921 (−) of Blakeslea trispora. This new compound formed during sexual interaction is a minor constituent of the culture media and its structure was elucidated by spectroscopic data, including 2D-NMR. A plausible biosynthetic pathway involving a double degradation of β-carotene, followed by several oxidations of the resulting monocyclofarnesane C15 fragment is proposed.This research was financed by Junta de Andalucía (Grants FQM 340, CVI 910, and P08-CVI-03901) and the Spanish Government (Grant CTQ 2010-16818, subprogram BQ)

Bubble concentration on spheres for supercritical elliptic problems

We consider the supercritical Lane-Emden problem (P_\eps)\qquad -\Delta v= |v|^{p_\eps-1} v \ \hbox{in}\ \mathcal{A} ,\quad u=0\ \hbox{on}\ \partial\mathcal{A} where $\mathcal A$ is an annulus in \rr^{2m}, $m\ge2$ and p_\eps={(m+1)+2\over(m+1)-2}-\eps, \eps>0. We prove the existence of positive and sign changing solutions of (P_\eps) concentrating and blowing-up, as \eps\to0, on $(m-1)-$dimensional spheres. Using a reduction method (see Ruf-Srikanth (2010) J. Eur. Math. Soc. and Pacella-Srikanth (2012) arXiv:1210.0782)we transform problem (P_\eps) into a nonhomogeneous problem in an annulus \mathcal D\subset \rr^{m+1} which can be solved by a Ljapunov-Schmidt finite dimensional reduction

Plus ça change : pots, crucibles and the development of metallurgy in Chalcolithic Las Pilas (Mojácar, Spain)

This paper considers the structure of production, distribution and consumption of ceramics within Chalcolithic communities of SE Iberia, an important region for modelling social and technological change in the recent prehistory of Eurasia. Our research provides new data through the comparative analysis of domestic and metallurgical ceramics, as well as building and other clay-rich materials from the archaeological site of Las Pilas (2875–2620 cal. BC 2σ to 2460–2205 cal. BC 2σ) (Mojácar, Almería). In total, 56 samples are characterised by optical petrography, with SEM analysis of 22 of those individuals, in order to assess firing conditions. Results point to the existence of a local tradition in which domestic and metallurgical wares exhibit important similarities in their production processes. In terms of technology, the assemblage shows a relative homogeneity, although firing conditions, surface treatment and decoration seem to have played an important role in the differentiation of highly symbolic wares from other ceramics. We conclude that raw material procurement and processing at Las Pilas differ from those at other Copper Age sites already studied in SE and SW Iberia. This is in agreement with earlier archaeometallurgical studies on Las Pilas, suggesting the development of local and community-based technological traditions. As such, the paper attempts to bridge the recent divide between re-emergent top-down models and our detailed understandings of technological practice