Diet of the White-tailed Kite (Elanus leucurus) in Argentina

Aproximadamente 61 especies de Falconiformes se distribuyen en territorio argentino (Canevari et al. 1991). Contrastando con este elevado número, sólo unas pocas (e.g., Geranoaetus melanoleucus, Circus buffoni, Falco femoralis) han recibido alguna atención, especialmente en los últimos años, en cuanto a sus hábitos dietarios (véase Pardiñas & Cirignoli en prensa y las referencias allí citadas).Fil: Leveau, Lucas Matias. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Leveau, Carlos Marcelo. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina. Universidad Nacional de La Plata; Argentin

Inhibition of Xanthomonas fragariae, Causative Agent of Angular Leaf Spot of Strawberry, through Iron Deprivation.

In commercial production settings, few options exist to prevent or treat angular leaf spot (ALS) of strawberry, a disease of economic importance and caused by the bacterial pathogen Xanthomonas fragariae. In the process of isolating and identifying X. fragariae bacteria from symptomatic plants, we observed growth inhibition of X. fragariae by bacterial isolates from the same leaf macerates. Identified as species of Pseudomonas and Rhizobium, these isolates were confirmed to suppress growth of X. fragariae in agar overlay plates and in microtiter plate cultures, as did our reference strain Pseudomonas putida KT2440. Screening of a transposon mutant library of KT2440 revealed that disruption of the biosynthetic pathway for the siderophore pyoverdine resulted in complete loss of X. fragariae antagonism, suggesting iron competition as a mode of action. Antagonism could be replicated on plate and in culture by addition of purified pyoverdine or by addition of the chelating agents tannic acid and dipyridyl, while supplementing the medium with iron negated the inhibitory effects of pyoverdine, tannic acid and dipyridyl. When co-inoculated with tannic acid onto strawberry plants, X. fragariae's ability to cause foliar symptoms was greatly reduced, suggesting a possible opportunity for iron-based management of ALS. We discuss our findings in the context of 'nutritional immunity,' the idea that plant hosts restrict pathogen access to iron, either directly, or indirectly through their associated microbiota

The failed liberalisation of Algeria and the international context: a legacy of stable authoritarianism

The paper attempts to challenge the somewhat marginal role of international factors in the study of transitions to democracy. Theoretical and practical difficulties in proving causal mechanisms between international variables and domestic outcomes can be overcome by defining the international dimension in terms of Western dominance of world politics and by identifying Western actions towards democratising countries. The paper focuses on the case of Algeria, where international factors are key in explaining the initial process of democratisation and its following demise. In particular, the paper argues that direct Western policies, the pressures of the international system and external shocks influence the internal distribution of power and resources, which underpins the different strategies of all domestic actors. The paper concludes that analysis based purely on domestic factors cannot explain the process of democratisation and that international variables must be taken into more serious account and much more detailed

\u3cem\u3eiac\u3c/em\u3e Gene Expression in the Indole-3-Acetic Acid-Degrading Soil Bacterium \u3cem\u3eEnterobacter soli\u3c/em\u3e LF7

We show for soil bacterium Enterobacter soli LF7 that the possession of an indole-3-acetic acid catabolic (iac) gene cluster is causatively linked to the ability to utilize the plant hormone indole-3-acetic acid (IAA) as a carbon and energy source. Genome-wide transcriptional profiling by mRNA sequencing revealed that these iac genes, chromosomally arranged as iacHABICDEFG and coding for the transformation of IAA to catechol, were the most highly induced (\u3e29-fold) among the relatively few (iac cluster were genes for a major facilitator superfamily protein (mfs) and enzymes of the β-ketoadipate pathway (pcaIJD-catBCA), which channels catechol into central metabolism. This entire iacHABICDEFG-mfs-pcaIJD-catBCA gene set was constitutively expressed in an iacR deletion mutant, confirming the role of iacR, annotated as coding for a MarR-type regulator and located upstream of iacH, as a repressor of iac gene expression. In E. soli LF7 carrying the DNA region upstream of iacH fused to a promoterless gfp gene, green fluorescence accumulated in response to IAA at concentrations as low as 1.6 μM. The iacH promoter region also responded to chlorinated IAA, but not other aromatics tested, indicating a narrow substrate specificity. In an iacR deletion mutant, gfp expression from the iacH promoter region was constitutive, consistent with the predicted role of iacR as a repressor. A deletion analysis revealed putative −35/−10 promoter sequences upstream of iacH, as well as a possible binding site for the IacR repressor

Dieta de la Lechuza de Campanario (Tyto alba) a lo largo de un gradiente longitudinal-latitudinal en Argentina Central

Se analizó la dieta de la Lechuza de Campanario (Tyto alba) basada en muestras provenientes de nueve localidades a lo largo de un gradiente ambiental de 5º de latitud y 5º de longitud, sobre 500 km en dirección N-S y E-O, en la provincia de Buenos Aires (Argentina). Se identificaron 3251 items presa, principalmente roedores sigmodontinos nativos. Oligoryzomys flavescens fue la presa predominante hacia el noreste del gradiente, mientras que Calomys spp. fueron las presas más comunes hacia el sudoeste. La diversidad y riqueza de presas fue mayor hacia el sur. Los ensambles de roedores consumidos por la Lechuza de Campanario mostraron diferencias significativas entre aquellas localidades ubicadas en los extremos del gradiente, correspondientes a diferentes unidades fitogeográficas.We studied the food habits of the Barn Owl (Tyto alba) based on samples from nine coastal localities along an environmental gradient of 5º of latitude and 5º of longitude, about 500 km N-S and EW, in the Buenos Aires Province (Argentina). We identified 3251 prey items, mainly native sigmodontine rodents. Oligoryzomys flavescens was the predominant prey species in the diet of the owls in the northeastern part of the gradient, while Calomys spp. were the most common prey species toward the southwestward. Prey diversity and total vertebrate prey richness were greater towards the south. The rodent assemblages consumed by Barn Owls showed significant differences among the localities settled at the opposite extremes of the gradient, corresponding to different phytogeographic units Prey diversity and total vertebrate prey richness were greater towards the south. The rodent assemblages consumed by Barn Owls showed significant differences among the localities settled at the opposite extremes of the gradient, corresponding to different phytogeographic units part of the gradient, while Calomys spp. were the most common prey species toward the southwestward. Prey diversity and total vertebrate prey richness were greater towards the south. The rodent assemblages consumed by Barn Owls showed significant differences among the localities settled at the opposite extremes of the gradient, corresponding to different phytogeographic units Prey diversity and total vertebrate prey richness were greater towards the south. The rodent assemblages consumed by Barn Owls showed significant differences among the localities settled at the opposite extremes of the gradient, corresponding to different phytogeographic units localities along an environmental gradient of 5º of latitude and 5º of longitude, about 500 km N-S and EW, in the Buenos Aires Province (Argentina). We identified 3251 prey items, mainly native sigmodontine rodents. Oligoryzomys flavescens was the predominant prey species in the diet of the owls in the northeastern part of the gradient, while Calomys spp. were the most common prey species toward the southwestward. Prey diversity and total vertebrate prey richness were greater towards the south. The rodent assemblages consumed by Barn Owls showed significant differences among the localities settled at the opposite extremes of the gradient, corresponding to different phytogeographic units Prey diversity and total vertebrate prey richness were greater towards the south. The rodent assemblages consumed by Barn Owls showed significant differences among the localities settled at the opposite extremes of the gradient, corresponding to different phytogeographic units part of the gradient, while Calomys spp. were the most common prey species toward the southwestward. Prey diversity and total vertebrate prey richness were greater towards the south. The rodent assemblages consumed by Barn Owls showed significant differences among the localities settled at the opposite extremes of the gradient, corresponding to different phytogeographic units Prey diversity and total vertebrate prey richness were greater towards the south. The rodent assemblages consumed by Barn Owls showed significant differences among the localities settled at the opposite extremes of the gradient, corresponding to different phytogeographic unitsFil: Leveau, Lucas Matias. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Bogdaschewsky, Rodolfo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentin

The Roman centuriated landscape: conception, genesis and development as inferred from the Ager Tarraconensis case

Although centuriation was only one system of Roman land division, its impact on the landscape and its visibility in modern field arrangements make it the most commonly recognized expression of Roman landscapes. Centuriated grid systems are usually analyzed from a materialistic point of view and consequently regarded as an assertion of Roman dominance over conquered territories. In this sense, their productive function is clear. The hinterland of Tarraco (the ancient capital of the Roman province of Tarraconensis) offers one of the most clearly documented examples of multiple-grid centuriated systems. From 2006 to 2010, the Landscape Archaeology Research Group (GIAP) of the Catalan Institute of Classical Archaeology employed a wide array of digital and field methodologies at Tarraco to record the traces of centuriated land divisions and their Roman origin. Most importantly, these methods have allowed research to move beyond pure description of the traces to explore the concepts and ideas behind the making of a centuriated landscape. By using Tarraco as a case study, this article shows how centuriation was not only a system for dividing the land but also a conceptual appropriation of the landscape based on a strong mythical and religious backgroun

Understanding the physiology of Lactobacillus plantarum at zero growth

The physiology of Lactobacillus plantarum at extremely low growth rates, through cultivation in retentostats, is much closer to carbon-limited growth than to stationary phase, as evidenced from transcriptomics data, metabolic fluxes, and biomass composition and viability.Using a genome-scale metabolic model and constraint-based computational analyses, amino-acid fluxes—in particular, the rather paradoxical excretion of Asp, Arg, Met, and Ala—could be rationalized as a means to allow extensive metabolism of other amino acids, that is, that of branched-chain and aromatic amino acids.Catabolic products from aromatic amino acids are known to have putative plant-hormone action. The metabolism of amino acids, as well as transcription data, strongly suggested a plant environment-like response in slow-growing L. plantarum, which was confirmed by significant effects of fermented medium on plant root formation