CONICET Digital

Lutzomyia longipalpis urbanisation and control

Lutzomyia longipalpis urbanisation and control Salomón, Oscar Daniel; Feliciangeli, María Dora; Quintana, María Gabriela; Afonso, Margarete Martins Dos Santos; Rangel, Elizabeth Ferreira Since the description of Lutzomyia longipalpis by Lutz and Neiva more than 100 years ago, much has been written in the scientific literature about this phlebotomine species. Soares and Turco (2003) and Lainson and Rangel (2005) have written extensive reviews focused on vector-host-parasite interactions and American visceral leishmaniasis ecology. However, during the last two decades, the success of Lu. longipalpis in colonising urban environments and its simultaneous geographical spreading have led to new theoretical and operational questions. Therefore, this review updates the general information about this species and notes the more challenging topics regarding the new scenario of urbanisation-spreading and its control in America. Here, we summarise the literature on these issues and the remaining unsolved questions, which pose recommendations for operational research.

Amphibians in a changing world: a global look at their conservation status

Amphibians in a changing world: a global look at their conservation status Loyola, Rafael; Lemes, Priscila; Urbina Cardona, Nicolás; Baldo, Juan Diego; Lescano, Julian; Nori, Javier Currently, more than 40% of extant amphibian species are threatened with extinction and a quarter of them still lack information to be classified as threatened, being therefore enlisted as Data Deficient by the International Union for the Conservation of Nature (IUCN) (1,2). Furthermore, amphibians are the greatest underrepresented group in the global network of protected areas (PAs) worldwide. A decade ago, some studies showed that around 17% of amphibian species lived completely outside of protected areas (3). Obviously, the underrepresentation of amphibians in protected areas is much higher for range-restricted species that inhabit highly humanmodified landscapes. Even in face of this worrying scenario, since 2004 not a single update has been published showing amphibian species represented inside PAs at the global scale. Actually, there is a large gap of information, especially if we consider that today data on the distribution of many amphibian species are available, and the areas covered by PAs has increased over the last ten years from 11% to more than 13% worldwide

First insights on the retroelement Rex1 in the cytogenetics of frogs

First insights on the retroelement Rex1 in the cytogenetics of frogs Nascimento, Juliana; Baldo, Juan Diego; Lourenço, Lucina Background: While some transposable elements (TEs) have been found in the sequenced genomes of frog species, detailed studies of these elements have been lacking. In this work, we investigated the occurrence of the Rex1 element, which is widespread in fish, in anurans of the genus Physalaemus. We isolated and characterized the reverse transcriptase (RT)-coding sequences of Rex1 elements of five species of this genus. Results: The amino acid sequences deduced from the nucleotide sequences of the isolated fragments allowed us to unambiguously identify regions corresponding to domains 3-7 of RT. Some of the nucleotide sequences isolated from Physlaemus ephippifer and P. albonotatus had internal deletions, suggesting that these fragments are likely not active TEs, despite being derived from a Rex1 element. When hybridized with metaphase chromosomes, Rex1 probes were revealed at the pericentromeric heterochromatic region of the short arm of chromosome 3 of the P. ephippifer karyotype. Neither other heterochromatin sites of the P. ephippifer karyotype nor any chromosomal regions of the karyotypes of P. albonotatus, P. spiniger and P. albifrons were detected with these probes. Conclusions: Rex1 elements were found in the genomes of five species of Physalaemus but clustered in only the P. ephippifer karyotype, in contrast to observations in some species of fish, where large chromosomal sites with Rex1 elements are typically present.

Los avatares de la gubernamentalidad y la cuestión del Estado. una aproximación crítica desde el gobierno de la pobreza y las prácticas de resistencia (Salta, Argentina)

Los avatares de la gubernamentalidad y la cuestión del Estado. una aproximación crítica desde el gobierno de la pobreza y las prácticas de resistencia (Salta, Argentina); The vicissitudes of governmentality and the question of the State. a critical approach from the government of poverty and practices of resistance (Salta, Argentina) Paulizzi, Maria Cora; Milana, Maria Paula El artículo pretende aportar algunos trazos teóricos, metodológicos y prácticos para la lectura de la cuestión del Estado y el poder, desde la perspectiva de la gubernamentalidad sugerida por Foucault y sus herencias latinoamericanas. Se parte del supuesto de que en la actualidad argentina y salteña, la multiplicidad de lógicas y prácticas de gobierno que codifican al Estado y sus avatares encuentran una clara expresión en el gobierno de la pobreza y en los diagramas vinculares entre gobernados y gobernantes, tejidos en los móviles del poder y la resistencia. En esta dirección, se delinean dos ejes expositivos. Por un lado, una analítica de los conceptos y cuestiones sugeridas desde la propuesta de la gubernamentalidad; por otro lado, una aproximación al gobierno de la pobreza y con ello a dos casos que dan cuenta del entramado relacional entre gobernados-gobernantes y prácticas de gobierno, resistencia y autogobierno entre las cuales se configura y re-configura el rol del Estado. Apostando a una “una ontología del presente”, se analizan formas de poder y resistencia que aún hoy en día se constituyen, reconfigurándose. Asimismo se sugiere un cruce metodológico entre genealogía y etnografía, en la apuesta a un ejercicio crítico de pensamiento a fines de contribuir a desnaturalizar y des-sustancializar las prácticas de gobierno, sus lógicas y nuestras conductas presentes.; This article aims to provide some theoretical, methodological and practical devices about the question of the state and power, from the governmentality perspective suggested by Foucault and their Latin American heritage. It is assumed that in Argentina’s and Salta’s present, multiple logics and practices of government that codify the state and its vicissitudes are clearly expressed in the government of poverty and in relational frames between rulers and ruled, woven into power and resistance. It is proposed to place this exercise around two expositive axes, beginning with an analysis of concepts and suggested issues by the governmentality perspective; on the other hand an approach to the government of poverty, illustrating this through two case studies around relational frameworks between rulers and ruled, practices of government, resistance and self-government, which configures and reconfigures the state’s role. This work brings into play "an ontology of the present", analyzing forms of power and resistance that still constitutes and reconfigures. It implies a methodological crossroad between genealogy and ethnography, contributing to denature governance practices and logics as well as our present behavior.

Influence of raw material moisture on the synthesis of black tea production process

Influence of raw material moisture on the synthesis of black tea production process Vargas, Rafael Roque Alejandro; Vecchietti, Aldo Tea industry is one of the main activities in the northeast of Argentina. It presents some particularities respect of tea production in other regions of the world, mainly in the high level of automation in tea shoots harvesting. Besides, the factory configurations in terms of the equipment used in tea production are different and it is not clear if they are efficient or not. The objective of this work is to study the effects of the moisture in the raw material (tea shoots) in the optimal design of a tea manufacturing plant not only in the investment but also in the operation costs. A superstructure that includes all the equipment involved in black tea manufacturing is proposed and a Generalized Disjunctive Programming model (GDP) is formulated to find the optimal flow sheet to produce black tea minimizing investment and operation cost, considering different wet contents in the tea shoots. A comparisonwas also made among the optimal plant and typical factories configurations to analyze their performance. From the results obtained can be observed that if the moisture of raw material is below of 4.5 kg of water per kg of dry matter the optimal plant configuration does not change; above this value more investment is needed to extract the extra water content. A similar conclusion can be obtained from the analysis of the operation costs. The optimal configuration is formed by conventional preservation chambers, continuous withering belts, Rotorvane crusher, continuous fermenting machines and fluid bed dryers. Comparing other typical configurations against the optimal one, the operative unit cost is about 20% - 60% greater.

Sobre la atribución genérica de la especie 'Cerithium' valeriae de Verneuil & de Lorière, 1868

Sobre la atribución genérica de la especie 'Cerithium' valeriae de Verneuil & de Lorière, 1868 Cataldo, Cecilia Soledad; Calzada, Sebastián Se recuerdan y discuten las diferentes asignaciones genéricas de la especie Cerithium valeriae de Verneuil & de Lorière, 1868. Provisionalmente se propone dejar su atribución genérica abierta.; The different generic assignments for Cerithium valeriae are reminded. For the moment, the following assignment is proposed: “Cerithium” valeriae.

Phylogenetic analysis and taxonomic position of section Verrucosa of Panicum and its relationship with taxa of the Sacciolepis–Trichanthecium clade (Poaceae: Panicoideae: Paniceae)

Phylogenetic analysis and taxonomic position of section Verrucosa of Panicum and its relationship with taxa of the Sacciolepis–Trichanthecium clade (Poaceae: Panicoideae: Paniceae) Nicola, Marcela Viviana; Lizarazu, Mabel Angela; Scataglini, María Amalia The new genus Kellochloa is proposed, on the basis of morphological and molecular characters, to include two North American species of Panicum s.l., previously classified in sect. Verrucosa: P.brachyanthum and P. verrucosum. Both species are annual, with decumbent culms branching divaricately at the lower nodes, and erect culms with terminal and axillary inflorescences. The spikelets are pilose, with lower glume 1/6 to 1/4 the length of the spikelet, upper glume and lower lemma subequal, 3–5-nerved, the lower anthecium reduced to the lower lemma, and upper anthecium indurate, with bicellular microhairs and simple papillae evenly distributed all over the lemma and palea. Molecular phylogenetic studies, analyzing plastid ndhF and rpoA sequences, confirmed that these morphological characters are differential. The phylogenetic position and taxonomic features of the new genus are established and compared with Panicum s.str. and other taxa of the Sacciolepis–Trichanthecium clade. Full synonymies and descriptions, a distribution map, illustrations of both species, and a key are provided. Two new combinations are proposed. In addition, four African ungrouped species of Panicum s.l. were, for the first time, included in the phylogenetic analysis to analyze their relationship with the new genus and its positions in the Sacciolepis–Trichanthecium clade.

Laboratory and field studies to evaluate the potential of an open rearing system of Lysiphlebus testaceipes for the control of Aphis craccivora in Argentina

Laboratory and field studies to evaluate the potential of an open rearing system of Lysiphlebus testaceipes for the control of Aphis craccivora in Argentina Zumoffen, Leticia; Tavella, Julia Rita; Signorini, Marcelo; Salvo, Silvia Adriana The aim of this work was to examine, both in the field and in the laboratory, ecological aspects of selected plant–aphid–parasitoid interactions to evaluate their potential for the open rearing of the parasitoid Lysiphlebus testaceipes (Cresson) (Hymenoptera: Aphidiinae) for the control of Aphis craccivora (Koch) (Hemiptera: Aphididae) in alfalfa agroecosystems. To this end quantitative samplings of parasitoids and aphids were made fortnightly in three alfalfa crop fields and their spontaneously vegetated edges, in Rafaela (Santa Fe, Argentina), during three years (2009–2011). Three sink webs based on L.testaceipes, on a per-year basis, were constructed to assess the strength of the interactions established by aphids and parasitoids, the host ranges of alternative aphid species, and the tendencies in parasitoid host use across years. In the laboratory, emergence rates, parasitism rates, larval and pupal development times, and adult lifespan of L. testaceipes were analyzed by means of choice tests, including the alternative and the target aphid species in the assays. About 84 % of adults of L. testaceipes obtained in the samples came from Aphis nerii (Boyer de Fonscolombe), an innocuous aphid species only associated with plants of the genus Araujia Brotero (Apocynaceae). Based on our results, the system proposed has many features that support its feasibility to be used as an open rearing system of L. testaceipes: unrisky alternative aphid, easy reproduction of the banker plant and similar suitability of innocuous and pest aphid species for the parasitoid to oviposit and complete their development without noticeably preference for specific hosts.

Persistence of plants and pollinators in the face of habitat loss: Insights from trait-based metacommunity models

Persistence of plants and pollinators in the face of habitat loss: Insights from trait-based metacommunity models Astegiano, Julia; Guimarães Jr., Paulo R.; Cheptou, Pierre Olivier; Morais Vidal, Mariana; Mandai, Camila Yumi; Ashworth, Lorena; Massol, François The loss of natural habitats is one of the main causes of the global decline of biodiversity. Understanding how increasing habitat loss affects ecological processes is critical for mitigating the effects of environmental changes on biodiversity and thus on the supply of ecosystem services by natural habitats. Habitat loss negatively affects pollinator diversity and the pollination service provided by insects, a key ecosystem service supporting the quantity, quality and diversity of crops directly consumed by humans and the sexual reproduction of most flowering plants. By integrating evolutionary relationships among traits that may modulate plant response to habitat loss, the structure of plant ? pollinator interaction networks and metacommunity models, we examine how plant ? pollinator metacommunities might respond to habitat loss. The main predictions of our trait-based metacommunity model are that (1) variation on dispersal ability among plant species may prevent full metacommunity collapse under pollinator loss associated with increasing habitat loss; (2) habitat loss may select for plants with higher dispersal ability and higher autogamous self-pollination, and will typically decrease the incidence of pollination generalist plants; (3) metacommunities that comprise plants with high autonomous self-pollination ability may harbour higher richness of rare plant species when pollinator diversity declines with increased habitat loss. We discuss the implications of our results for the vulnerability of pollination services for biotically pollinated wild plants and crops co-occurring in human-dominated landscapes.

Isotope effect on the superconducting critical temperature of cuprates in the presence of charge order

Isotope effect on the superconducting critical temperature of cuprates in the presence of charge order Greco, Andres Francisco; Zeyher, Roland Using the large-N limit of the t–J model and also allowing for phonons and the electron–phonon interaction, we study the isotope effect α for coupling constants appropriate for YB2C3O y . We find that α has a minimum at optimal doping and increases strongly (slightly) towards the underdoped (overdoped) region. Using values for the electron–phonon interaction from the local density approximation we get good agreement for α as a function of T c and doping δ with recent experimental data in YB2C3O y . Our results strongly suggest that the large increase of α in the underdoped region is (a) caused by the shift of electronic spectral density from low to high energies associated with a competing phase (in our case a charge density wave) and the formation of a gap, and (b) compatible with the small electron–phonon coupling constants obtained from the local density approximation. We propose a similar explanation for the anomalous behavior of α in Sr-doped La2CuO4 near the doping 1/8.

Transiciones y afinidades biogeográficas

Transiciones y afinidades biogeográficas Ferro, Luis Ignacio Las transiciones biogeográficas involucran el pasaje de una entidad biogeográfica a otra en el espacio terrestre u oceánico del planeta. La naturaleza de las entidades o unidades biogeográficas puede ser variable de acuerdo al énfasis que se haga en la observación de los distintos aspectos de la distribución de la vida sobre la Tierra. Por ejemplo, en ecología del paisaje, las diferentes unidades se definen por homogeneidad estructural y de procesos funcionales (Forman, 1995; Vila Subirós et al., 2006). El ejemplo más gráfico quizás es un mosaico de bosques, pastizales, humedales, cultivos y áreas urbanas. Cada uno de los elementos del paisaje presenta características estructurales, morfológicas y/o de composición específica similares que los agrupan en una categoría dada y los diferencia de los restantes elementos. Sus límites tienen gran importancia funcional en el flujo e intercambio de materiales, energía e información genética; pueden ser sumamente diversos tanto morfológica como funcionalmente y han sido unificados bajo el concepto de bordes ecológicos (Cadenasso et al., 2003).

Pilot Field Trial of the EG95 Vaccine Against Ovine Cystic Echinococcosis in Rio Negro, Argentina: Second Study of Impact

Pilot Field Trial of the EG95 Vaccine Against Ovine Cystic Echinococcosis in Rio Negro, Argentina: Second Study of Impact Larrieu, Edmundo Juan; Mujica, Guillermo; Gauci, Charles G.; Vizcaychipi, Katherina; Seleiman, Marcos; Herrero, Eduardo; Labanchi, José Luis; Araya, Daniel; Sepúlveda, Luis; Grizmado, Claudia; Calabro, Arnoldo; Talmon, Gabriel; Poggio, Thelma Veronica; Crowley, Pablo; Cespedes, Graciela; Santillán, Graciela; García Cachau, Mariela; Lamberti, Roberto; Gino, Lilia; Donadeu, Meritxell; Lightowlers, Marshall W. Cystic echinococcosis (CE) is an important zoonotic disease caused by the cestode parasite Echinococcus granulosus. It occurs in many parts of the world where pastoral activities predominate, including the Rio Negro province of Argentina. Although CE control activities have been undertaken in the western regions of Rio Negro for more than two decades, the disease continues to remain prevalent in both the human and livestock animal populations. Vaccination of animal intermediate hosts of CE with the EG95 vaccine may provide a new opportunity to improve the effectiveness of CE control measures, although data are lacking about field application of the vaccine. Aims: Evaluate the impact of EG95 vaccination in sheep on the transmission of Echinococcus granulosus in a field environment. Methodology: Two trial sites were established in western Rio Negro province within indigenous communities. Vaccination of lambs born into one trial site was introduced and continued for 6 years. Prior to initiation of the trial, and at the end of the trial, the prevalence of CE in sheep was determined by necropsy. Weaned lambs received two injections of EG95 vaccine, approximately one month apart, and a single booster injection one year later. Vaccination was not implemented at the second trial site. A total of 2725 animals were vaccinated in the first year. Animals from this cohort as well as age-matched sheep from the control area were evaluated by necropsy. Key results: Introduction of the vaccine led to a statistically significant in the number and size of hydatid cysts in comparison to the situation prior to the introduction of the vaccine, or compared to CE prevalence in the control area where the vaccine was not applied. The prevalence of infection in the vaccinated area was also significantly reduced by 62% compared to the re-intervention level, being lower than the prevalence seen in the control area, although the difference from the control area after the intervention was not significant possibly due to limitations in the numbers of animals available for necropsy. Conclusions: Vaccination of sheep with the EG95 vaccine provides a valuable new tool which improves the effectiveness of CE control activities. Vaccination was effective even in a difficult, remote environment where only approximately half the lambs born into the communities were fully vaccinated.

T-duality and α′-corrections

T-duality and α′-corrections Marques, Diego; Nuñez, Carmen Alicia We construct an O(d, d) invariant universal formulation of the first-order alpha-prime-corrections of the string effective actions involving the dilaton, metric and two-form fields. Two free parameters interpolate between four-derivative terms that are even and odd with respect to a Z 2-parity transformation that changes the sign of the two-form field. The Z 2-symmetric model reproduces the closed bosonic string, and the heterotic string effective action is obtained through a Z 2-parity-breaking choice of parameters. The theory is an extension of the generalized frame formulation of Double Field Theory, in which the gauge transformations are deformed by a first-order generalized Green-Schwarz transformation. This deformation defines a duality covariant gauge principle that requires and fixes the four-derivative terms. We discuss the O(d, d) structure of the theory and the (non-)covariance of the required field redefinitions.

About the role of typical spacer/crosslinker on the design of efficient magnetic biocatalysts based on nanosized magnetite

About the role of typical spacer/crosslinker on the design of efficient magnetic biocatalysts based on nanosized magnetite Nicolás, Paula; Lassalle, Verónica Leticia; Ferreira, María Luján The immobilization of Candida antarctica lipase B (CALB) was carried out using glutaraldehyde (GLUT) and/or 3-aminopropyl-triethoxisilane (APTS). The aim of this work was to elucidate the role of these crosslinkers/functionalizers on the efficiency of the prepared nanosized catalysts in solvent-free oleic acid esterification.A series of biocatalysts were prepared in presence or absence of GLUT and APTS. The impact of the amount of initial CALB was also explored. An experimental design was utilized to study the variables that maximize biocatalyst activity.A strong dependence of enzymatic activity with the nominal amount of GLUT as well as the final protein/CALB loading was found. Nominal quantity of APTS did not affect catalyst́s activity when used in combination with GLUT. Additional studies demonstrated that stability during storage was mainly dependent on the enzyme loading. The optimum biocatalyst was reused 6 cycles without mass loss. Biocatalyst́s performance decreased with reuse. Mechanisms justifying these results were proposed.The role of GLUT and APTS on stability during storage and on differences between initial enzymatic activity and the performance in the reaction after two months was discussed. The problem of mixed interaction of CALB (covalent bonding plus simple adsorption) was carefully addressed to explain leaching of the lipaseLeaching and stability on storage should be included in the analysis of modifiers impact when support́s modifiers are used. The fresh and stored biocatalyst enzymatic activity has to be addressed looking at the practical aspects of implementation in technological settings.

Manejo de la recreación y el turismo en conservación

Manejo de la recreación y el turismo en conservación Encabo, Matilde; Boschi de Bergallo, Ana Maria; Sanchez, Sandra E.; Torre, María Gabriela; Paz Barreto, Daniel; Andrés, Juan Manuel; Mastrocola, Yusara Isis; Vazquez, Maria Victoria; Cánepa, Luis Homero; Buchiniz, Yanina Este proyecto de Investigación promueve el cambio de paradigma en el turismo y la recreación en naturaleza. Su objetivo general es desarrollar y evaluar conocimientos, metodologías y procesos científico tecnológicos que aporten al manejo del Turismo y la Recreación sustentable en áreas naturales y áreas naturales protegidas. Se basa en metodologías de la Ecología de la Recreación y el Turismo. aplicadas a la complejidad ecosistémica y territorial como: Limite de Cambio aceptable, Capacidad de carga Turística, Sistema Integral de Evaluación de Impactos a la Biodiversidad - Actividades de Turismo, entre otras. Algunas conclusiones son: Reforzar los aspectos ambientales de la sustentabilidad en el uso público turístico recreativo en naturaleza; Generar metodologías de análisis, evaluación y control con conocimiento científico de la naturaleza; Avanzar en aspectos teórico – prácticos del modelo Recreación y Turismo en Conservación.

Experiencia en la aplicación de la enseñanza de química de sólidos inorgánicos en forma de proyecto corto

Experiencia en la aplicación de la enseñanza de química de sólidos inorgánicos en forma de proyecto corto Belletti, Gustavo Daniel; Alconchel, Silvia Alejandra Se describe el desarrollo y puesta en ejecución de una metodología de enseñanza de Química de Sólidos Inorgánicos para alumnos de la carrera de Licenciatura en Química de la FIQ-UNL. Se empleó una estructura centrada en un proyecto corto de investigación sobre un sólido de interés tecnológico. En torno al mismo, los alumnos aprenden los contenidos teóricos-prácticos de una nueva asignatura e incorporan herramientas valiosas para su futuro desempeño profesional

El rol de los ambientes semi- naturales en la abundancia y diversidad de coleópteros edáficos en los viñedos de la Costa de Berisso, Argentina

El rol de los ambientes semi- naturales en la abundancia y diversidad de coleópteros edáficos en los viñedos de la Costa de Berisso, Argentina Paleologos, María Fernanda; Pereyra, Patricia Cecilia; Sarandon, Santiago Javier; Cicchino, Armando Conrado Los ambientes semi-naturales que rodean los cultivos aseguran el mantenimiento de las funciones ecológicas. Sin embargo, el aumento de la diversidad dentro de las parcelas cultivadas también contribuiría a mejorar las funciones ecológicas en el agroecosistema. Se evaluó la influencia de hábitats semi-naturales en la abundancia, riqueza y diversidad de coleópteros, así como la dominancia relativa de los diferentes grupos funcionales (depredadores, descomponedores, fitófagos). Este estudio se llevó a cabo en dos fincas de vid con diferente composición de la cobertura vegetal: un viñedo con manejo tradicional de tierras bajas e inundables y un "nuevo" viñedo de tierras altas no inundables. Los coleópteros se muestrearon mediante trampas de caída. Se identificaron 24 familias de coleópteros en el sistema de la zona baja y 23 en el de zona alta. El grado de importancia de los ambientes semi-naturales fue marcadamente diferente entre regiones. En el sistema “tradicional”, la abundancia de coleópteros y la abundancia de los grupos tróficos fue mayor en la parcela cultivada que en los ambientes semi-naturales. En el “nuevo” viñedo fueron mayores en ambientes semi-naturales que en la parcela cultivada. Nuestros resultados muestran que el papel de los ambientes semi-naturales, para favorecer la presencia de fauna, depende de sus características ambientales, y de su complejidad vegetal dentro de las parcelas de cultivo.

Exploring food preferences and the limits of feeding flexibility of seed-eating desert birds

Exploring food preferences and the limits of feeding flexibility of seed-eating desert birds Camín, Sergio Ramón; Cueto, Víctor; Lopez de Casenave, Javier Nestor; Marone, Luis Habitat degradation caused by cattle grazing may be a serious threat for seed-eating birds because theavailability of beneficial seeds usually diminishes in grazed areas. Ecologically plastic species might, however, circumventfood deprivation via changes in foraging behaviour. We studied the limits of feeding flexibility and factors affecting seedpreferences in Zonotrichia capensis, Diuca diuca, and Saltatricula multicolor.We experimentally assessed preferences forseeds of eight grass and eight forb species by using a protocol that combines choice and non-choice trials, and employed adifferent batch of experiments to evaluate some plausible causes of different feeding flexibility. On average, birds consumed45?140% more grass than forb seeds, confirming previous results. Z. capensis preferred several grass and forb seeds, andshowed maximum feeding flexibility. S. multicolor and, to a lesser extent, D. diuca, were grass specialists that preferredlarge and medium-sized grass seeds. The size of forb seeds did not affect preferences. Coat thickness of grass seeds didnot seriously reduce consumption levels. Birds showed low ability to feed on resources characteristic of degradedenvironments (i.e. annual grass seeds). Species-specific differences in behavioural flexibility could be used to predictdietary and numerical responses of seed-eating birds to habitat degradation.

Antimicrobial resistance in thermotolerant Campylobacter isolated from different stages of the poultry meat supply chain in Argentina

Antimicrobial resistance in thermotolerant Campylobacter isolated from different stages of the poultry meat supply chain in Argentina Zbrun, María Virginia; Olivero, Carolina Raquel; Romero Scharpen, Analía; Rossler, Eugenia; Soto, Lorena Paola; Astesana, Diego Martín; Blajman, Jesica; Berisvil, Ayelén Patricia; Signorini Porchietto, Marcelo Lisandro; Frizzo, Laureano Sebastian The objective of this study was to investigate the antimicrobial resistance in thermotolerant Campylobacter spp. isolated from different stages of the poultry meat supply chain in Argentina. Six poultry meat chains were studied from the reproductive farm to the chicken at the retail. Chickens sampled along each food chain were from the same batch. Samples collected were: a) cloacal samples from hens and chickens on the farm, b) chicken carcasses from the slaughterhouse and retail market. Samples obtained were examined for Campylobacter spp. Antimicrobial resistance was evaluated using the disk diffusion method. Almost all isolates were resistant to nalidixic acid (91.2%) and ciprofloxacin (88.2%). A large proportion of thermotolerant Campylobacter isolated from hens and broilers <1wk showed resistance to erythromycin in comparison with the rest of the stages of the poultry meat supply chain (P=0.031). Campylobacter isolated from broilers (both <1wk and >5wk) and carcasses at slaughterhouse and at retail showed a proportion of resistance to ciprofloxacin and enrofloxacin higher than isolates from hens (P=0.015 and P=0.031, respectively). One strain was resistant to all the antibiotics analyzed, and 46.1% of the isolates were resistant to three or more drug classes. Almost 50% of the isolates were resistant to all quinolones tested (ciprofloxacin, nalidixic acid, and enrofloxacin), and 13.2% were resistant to all quinolones and erythromycin. Campylobacter strains isolated from carcasses at retail showed higher resistance to all quinolones than strains isolated from hens (P=0.016). These results reflect an alarming situation with potential serious consequences to the public health.

Controlling Rotavirus-associated diarrhea: Could single-domain antibody fragments make the difference?

Controlling Rotavirus-associated diarrhea: Could single-domain antibody fragments make the difference?; Hacia el control de la diarrea por rotavirus A: ¿podrían los nanoanticuerpos VHH marcar la diferencia? Maffey, Lucía; Vega, Celina Guadalupe; Parreño, Gladys Viviana; Garaicoechea, Lorena Laura Group A Rotavirus (RVA) remains a leading cause of severe diarrhea and child mortality. The variable domain of camelid heavy chain antibodies (VHH) display potent antigen-binding capacity, have low production costs and are suitable for oral therapies. Two sets of anti-RVA VHHs have been developed: ARP1-ARP3; 2KD1-3B2. Here, we explore the potential of both sets as a prevention strategy complementary to vaccination and a treatment option against RVA-associated diarrhea in endangered populations. Both sets have been expressed in multiple production systems, showing extensive neutralizing capacity against strains of RVA in vitro. They were also tested in the neonatal mouse model with various degrees of success in preventing or treating RVA-induced diarrhea. Interestingly, mitigation of the symptoms was also achieved with freeze-dried ARP1, so that it could be applied in areas where cold chains are difficult to maintain. 3B2 was tested in a pre-clinical trial involving gnotobiotic piglets where it conferred complete protection against RVA-induced diarrhea. ARP1 was used in the first clinical trial for anti-RVA VHHs, successfully reducing stool output in infants with RVA diarrhea, with no detected side effects.

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