Sindicador de canales de noticias
Desarrollo Global desde una perspectiva local: importancia de la vinculación y diplomacia en las Ciencias, Educación, y Formación continua; Global development from local perspective: importance of Entailment and Diplomacy in Sciences, Education, and Continuous formation
Bracamonte Gontero, Lucia V.; Bracamonte, Angel Guillermo
Esta breve comunicación intenta hacer reflexionar sobre el desarrollo a todos los niveles que se puedan evaluar en el bienestar humano desde un desarrollo local, hacia una escala global o planetaria. Y en este sentido los principales ejes en los cuales se basa son sobre la importancia en la vinculación de los individuos en sus cercanías al igual que a mayores distancias físicas e igualmente culturales. Y se debe mencionar estos dos aspectos en una realidad en donde existen diferencias culturales. Estos factores afectan al desarrollo tecnológico, educación; nivel, y calidad de vida. Es así que los diferentes índices de desarrollo tales como índices estadísticos en Demografía y Economía pueden ser muy variados. Pero, es importante destacar que para realizar una mejora local en tiempos más acotados, hay que vincularse para interactuar sea recibiendo o brindando un bien material u abstracto el cual pueda acelerar ese proceso deseado. Y es allí que la Vinculación y transferencia en Tecnología y Educación en diferentes esferas de desarrollo humano es vital. De igual manera la formación continua, la cual en las últimas generaciones se ha producido cambios drásticos en políticas de Educación mediante la creación de diferentes estrategias basadas en los medios de comunicación en diferentes formatos para acercar la información hacia los diferentes estratos sociales. De esta manera, se pueden acoplar diferentes niveles educativos con un factor en común relacionado con la curiosidad y con mentes abiertas para aprender, trabajar, y vivir en comunidad en el contexto de desarrollos de nuevas maneras sustentables inteligentes para vivir. Con estas perspectivas, el desarrollo y educación a nivel Universitario y de Postgrado en Ciencias teniendo en cuenta la transmisión de la importancia de los factores mencionados tales como; i) la vinculación, iii) desarrollo de conocimiento, y iii) transferencia, es fundamental. Finalmente, se debe destacar la particular necesidad de a todos los niveles de las buenas relaciones humanas, inteligencia emocional, y diplomacia para tener éxito desde los más simples hacia los más complicados desafíos a abordar en el transcurso de cualquier desarrollo.
Advances in Quantum properties of Graphene applied for targeted functional Nanomaterials and Metamaterials
Advances in Quantum properties of Graphene applied for targeted functional Nanomaterials and Metamaterials
Bracamonte, Angel Guillermo
In the present work we describe the most important quantum properties of graphene and derivatives recently published. We discuss how these properties were incorporated into varied hybrid materials such as substrates for specific tuning of matter to track varied quantum signals. Their potential applications were analyzed from nanomaterial and nanotechnology. In particular graphene, its derivatives and other carbon-based allotropes were chosen due to their special chemical structure and properties from the nanoscale to larger lengths, according to specific applications. As expected, these carbon-based and related materials’ highly ordered and condensed electronic configuration showed particular electronic properties below the nanoscale. Thus, we discussed the generation of pseudo-electromagnetic fields and conduction bands. This particular property could also interact with different quantized energy levels and quantum properties, such as those focused on: i) Dirac electron interaction and conduction, ii) anomalous quantized hall effects, iii) magnetic effects, iv) excitons, v) polaron generations, d vi) Fermi and Landau levels. These different phenomena were discussed about the particular topological states of graphene by tuning their 3D chemical structures. Therefore, quantum phenomena and their possible modifications such as quantum interference, potential improvements and encrypted signal transduction were considered for applications.
Pseudo-dual pairs and branching of Discrete Series
Pseudo-dual pairs and branching of Discrete Series
Vargas, Jorge Antonio
For a semisimple Lie group G, we study Discrete Series representations with admissible branching to a symmetric subgroup H. This is done using a canonical associated symmetric subgroup H0, forming a pseudo-dual pair with H, and a corresponding branching law for this group with respect to its maximal compact subgroup. This is in analogy with either Blattner's or Kostant-Heckmann multiplicity formulas, and has some resemblance to Frobenius reciprocity. We give several explicit examples and links to Kobayashi-Pevzner theory of symmetry breaking and holographic operators. Our method is well adapted to computer algorithms, such as for example the Atlas program.
Subutilización de la fuerza de trabajo antes y después del escenario COVID-19 en la Argentina
Subutilización de la fuerza de trabajo antes y después del escenario COVID-19 en la Argentina; Labor force underutilization before and after the covid-19 scenario in Argentina
Poy Piñeiro, Santiago; Alfageme, Camila Alejandra; Salvia, Hector Agustin
Este artículo se interesa por las consecuencias de la dinámica macroeconómica del período 2014-2021 en la reproducción de las asimetrías sistémicas que caracterizan al mercado de trabajo urbano argentino. ¿En qué medida el ciclo de estancamiento y crisis del período 2014-2019, agravado por la pandemia, provocó una acentuación de tales desequilibrios? Abordamos aquí la relación entre ciclos de bajo crecimiento económico, crisis y absorción productiva de la fuerza de trabajo El artículo evidencia que el ciclo prolongado de estancamiento y crisis agravada por la pandemia tuvo como resultado una expansión de distintas formas de excedentes de fuerza de trabajo y empobrecimiento transversal en la estructura social del trabajo. En este sentido, se concluye que el ciclo de crisis agravado por la pandemia ha generado condiciones adversas en términos de desigualdad y nuevas marginaciones socioeconómicas, para cuya reversión no ha bastado la recuperación económica del año 2021.; this article is interested in the consequences of the macroeconomic dynamics of the 2014-2021 period on the reproduction of the systemic asymmetries that characterize the argentine urban labor market. to what extent did the cycle of stagnation and crisis of the 2014-2019 period, aggravated by the pandemic, lead to an accentuation of such imbalances? We address here the relationship between cycles of low economic growth, crisis and productive absorption of the labor force the article evidences that the prolonged cycle of stagnation and crisis aggravated by the pandemic resulted in an expansion of different forms of surplus labor force and transversal impoverishment in the social structure of labor. in this sense, it is concluded that the cycle of crisis aggravated by the pandemic has generated adverse conditions in terms of inequality and new socio-economic marginalization, for whose reversal the economic recovery of the year 2021 has not been sufficient.
Macroinvertebrate biomonitoring in Latin America: Progress and challenges
Macroinvertebrate biomonitoring in Latin America: Progress and challenges
Cortelezzi, Agustina; Paz, Laura Estefania
Macroinvertebrates are used as bioindicators worldwide, but the high diversity of macroinvertebrate species and endemism in Latin America (LA) requires greater knowledge of this group to increase the effectiveness of biomonitoring. We examined some of the primary taxonomic and ecological studies on macroinvertebrates in the region, quantified the number of papers that used foreign and local indices, examined alternative approaches to bioassessment that may be more relevant for the region, and explored freshwater ecosystem management in LA. Here, we highlight the need to increase taxonomic knowledge and the number of specialists in local fauna, establish and maintain taxonomic collections in public institutions, and make online databases on the biodiversity in each country available. However, we also demonstrate that taxonomy specialists of different nationalities do collaborate on the generation of fundamental information about biodiversity in LA. We found that 57% of the 215 reviewed scientific articles from LA used foreign but locally adapted indices for biomonitoring aquatic ecosystems. Only 21% of these articles presented local indices developed in LA. New technologies, such as environmental DNA, offer substantial potential for bioassessment but only in regions where sufficient taxonomic knowledge exists and where species-level stressor–response relationships are well described. In the absence of more complete taxonomic re-cords, there could be some value in developing biological trait and multimetric indices, and occupancy models could be developed to analyze the relationship between taxa and stress factors. These tools could be adopted by researchers to generate more accurate biotic indices based on local taxa. Finally, in LA, bioindicators are used to support scientific research more often than as environmental monitoring tools. Environmental laws and regulations that support the biomonitoring of LA freshwaters and unified criteria for evaluating and monitoring aquatic ecosystems are essential to face regional and global challenges.
Fighting cichlids: An integrated multimodal analysis to understand female and male aggression in Cichlasoma dimerus
Fighting cichlids: An integrated multimodal analysis to understand female and male aggression in Cichlasoma dimerus
Scaia, María Florencia; Trudeau, Vance L.; Somoza, Gustavo Manuel; Pandolfi, Matias
Aggression has been historically linked to males and androgen levels and, even if females from different species also display aggressive behavior, female aggression is still widely understudied. The aim of the present work is to disentangle how sex differences in social plasticity can be explained by sex steroid hormone levels, gonadal state and/or morphometric characteristics. In this context, we performed intrasexual dyadic encounters to identify social plasticity after acquiring a winner or loser status in males and females of Cichlasoma dimerus. This integral analysis suggests that the reproductive and hormonal variables analyzed explain the behavioral variation among winner and loser males and females, and that there are significant differences between sexes and contest outcome when individual morphometric variables are excluded from the analysis. Interestingly, there are no sex differences in aggressive and submissive behaviors, and clustering into winners and losers is mainly explained by specific behavioral displays, such as bites, chases, approaches, passive copings, and escapes. Correlation heatmaps show a positive correlation between estradiol with aggression and a negative correlation with submission, suggesting estrogens may have a dual role regulating agonistic behavior. Finally, these results suggest that size difference can help to understand aggression in females but not in males, and that assessment of the opponent's body size is important to understand aggression also before the initiation of the contest in both sexes. Overall, this study constitutes an integral approach adding insights into the importance of reproductive and hormonal variables to understand social plasticity in males and females.
Enhanced electroseismic coupling at charged interfaces
Enhanced electroseismic coupling at charged interfaces
Thompson, A. H.; Monachesi, Leonardo Bruno; Zyserman, Fabio Ivan; Jouniaux, L.
Published field-scale studies of electroseismic (ES) surveying have detected harmonics of the source frequency in the recorded seismic signal. At the time the data were collected, the cause of these high frequencies was unknown. We have found that electric fields applied to lithologic interfaces create harmonics of the source frequency. At these interfaces, there are gradients in ionic concentrations in pore fluids and in situ electric fields associated with gradients in the electrochemical (EC) potential. When an electric field is applied to the junction in the direction of the internal field, the internal voltage gradient decreases and the resistivity decreases. When the applied field opposes the internal field, the internal field increases and the resistivity is high. Harmonics of the applied AC field occur when the amplitude of the applied electric field is comparable to the internal field. We use the sandstone/limestone interface as an illustrative example. An analytical model of rock interfaces predicts the wavelet response to an applied field. The theoretically predicted signal characteristics agree with the laboratory data. The model predicts that the distortion of the electric field induces strains on the rock matrix that are qualitatively similar to field measurements of the ES conversion. The estimated response from an EC junction is substantially larger than the electrokinetic conversion associated with the displacement of the pore-surface dipole layers.
Origin of Late Triassic Granitoids of the Coastal Cordillera of Southern Central Chile (34°–37°S): Multi-Isotopic Evidence of Slab Tearing Effects on Pre-Andean Magmagenesis
Origin of Late Triassic Granitoids of the Coastal Cordillera of Southern Central Chile (34°–37°S): Multi-Isotopic Evidence of Slab Tearing Effects on Pre-Andean Magmagenesis
Rossel, Pablo; Gianni, Guido Martin; Reinoso, Valeria; Fanning, C. Mark; Ducea, Mihai N.; Muñoz, Tamara; Salvat, Daniela
The Coastal Cordillera of Central Chile (34°–37°S) holds a series of Late Triassic granitoids classically interpreted as early Andean subduction-related magmatism based on their arc-like geochemical signature. Here, we present geochemical, isotopic, and geochronological data and a tomotectonic analysis that challenge this idea indicating a local interruption of the normal subduction process likely associated with a slab-tearing event. Our results suggest that the source of the magmas is related to melting of asthenospheric mantle and crustal rocks of a metasedimentary Paleozoic complex. We suggest that partial melting of these sources was triggered by a slab tear-related asthenosphere upwelling producing high-silica S/I- and S-Type granites of the Constitución and Hualpén areas, and anorogenic A-Type granitoids in Cobquecura area. Also, partial melting of a metasomatized asthenospheric mantle plus continental crust that experienced previous high-temperature hydrothermal alteration would have generated high-silica magmas with low δ18O, high Pb, CHUR-like 87Sr/86Sr, and 143Nd/144Nd ratios that originated La Estrella Granite. Our results offer an alternative explanation for the existence of subtle magmatic arc-like geochemical signatures in the study area and support a segmentation of the active margin during the Late Triassic. The widespread upper-plate magmatic record of slab-tearing, spanning the Coastal Cordillera of Central Chile to the intraplate Neuquén basin in Argentina, and the lower mantle record of a slab gap, detected in ours and previous tomotectonic analyses, make the Late Triassic slab-tearing event in southwestern Pangea the most robustly constrained pre-Cenozoic slab tear process so far.
Una nota breve sobre desastres naturales y crecimiento
Una nota breve sobre desastres naturales y crecimiento; A short note on natural disasters and growth
González, Fernando Antonio Ignacio
Los desastres naturales constituyen una seria amenaza a nivel global. Cada año una creciente cantidad de desastres naturales tiene lugar en diferentes regiones del mundo (Centre for Research on the Epidemiology of Disasters [CRED], 2020a), y se espera que esto se profundice, a futuro, a consecuencia del cambio climático (Intergovernmental Panel on Climate Change [IPCC], 2018). En esta nota breve se analizan las predicciones teóricas del impacto de los desastres naturales sobre el crecimiento económico, con especial énfasis en los contrastes presentes en los diferentes modelos.; Natural disasters constitute a serious threat on a global level. Each year they generate large losses, and their consequences affect macroeconomic magnitudes such as growth. The literature on this topic (disasters and growth) is scarce and the theoretical predictions are not unambiguous. In this note, this topic is revisited based on different growth models. The results indicate that the direction of the effect is not obvious from a theoretical perspective and presents wide heterogeneities: thus, the effect differs according to the parameter that is assumed to be affected by the occurrence of the disaster (capital stock, savings rate, technology, etc.) and according to the time horizon considered. Contrary to expectations, a disaster could result in increased growth if it promotes (precautionary) saving, facilitates capital upgrading (replacement of destroyed capital with a newer one), or encourages investment in R&D.
Experiences of preservice mathematics teachers during their education in times of pandemic
Experiences of preservice mathematics teachers during their education in times of pandemic
Villarreal, Monica Ester; Villa Ochoa, Jhony Alexander; Galleguillos, Jeannette
Due to the COVID-19 pandemic, educational institutions at all levels closed their doors and began to operate remotely. In this paper, we analyze the educational experiences of preservice mathematics teachers (PMTs) enrolled in mathematics teacher education programs from three South American universities, as the pandemic was unfolding. An exploratory study was conducted, based on an inductive and thematic qualitative text analysis of narratives written by 24 PMTs. Based on the study, we report on the following aspects: (1) experiences of PMTs in the passage to remote education (RE) mode (considering characteristics of remote classes—interactions, the rhythm of the class, teaching work—time management, home–classroom fusion, and physical and psychological discomfort), and (2) opportunities and limitation experienced by PMTs in relation to the use of technologies. The results of the study suggest the need to rethink teacher education programs regarding the integration of technologies in mathematics classes, the opportunities offered by hybrid education, and teacher education for distance teaching.
Caracterización geotécnica de los flujos de tierra en las barrancas del río Paraná, en Santa Elena, provincia de Entre Ríos, Argentina
Caracterización geotécnica de los flujos de tierra en las barrancas del río Paraná, en Santa Elena, provincia de Entre Ríos, Argentina; Geotechnical characterization of the landslides in the Paraná river cliffs of Santa Elena, Entre Ríos Province, Argentina
Soffiantini, Javier; Brunetto, Ernesto
La ciudad de Santa Elena, ubicada en el noroeste de la provincia de Entre Ríos, expone enormes barrancas sobre la costa del río Paraná. Además del magnífico escenario natural que exhibe la ciudad, la actividad retrocedente de las barrancas, representa una verdadera amenaza geológica para los habitantes del lugar. Este fenómeno se manifiesta mediante súbitos y repentinos movimientos gravitacionales. El último episodio causante de grandes daños fue en 2016, coincidente con un periodo de grandes lluvias y crecidas extraordinarias del río Paraná producto de un fuerte Niño-Oscilación del Sur (ENSO). El evento húmedo aumentó considerablemente el nivel del río y la saturación de los sedimentos que conforman las barrancas. A partir de un detallado reconocimiento de campo que incluyó estudios estratigráficos y reconocimiento de los principales rasgos dejados por el movimiento gravitacional, junto con datos aportados por una serie de 6 perforaciones geotécnicas, fue posible construir un modelo de remoción en masa. Las características geomorfológicas y los parámetros geotécnicos medidos en las perforaciones sugieren la ocurrencia de un proceso de tipo Flujo de Tierra. La identificación de las causas que precipitan la desestabilización de la barranca junto con un adecuado modelo interpretativo de remoción en masa permite adecuar las obras de ingeniería factibles de mitigar o neutralizar potenciales daños.; Santa Elena city in the Entre Ríos province exposes huge cliffs along the shorelines of the Paraná River. This scenario of the city provides a wonderful view of the river. However, the height and the steep slopes of these cliffs pose a permanent hazard to people that live there. Landslides are the main cause of backward movement of the cliffs. Both the stratigraphic features and the increase of water saturation by infiltration play an essential role to trigger this type of landslides. The last big episode of landslides occurred in 2016, simultaneously with a strong El Niño Southern Oscillation event (ENSO), which caused high precipitation and flooding of the Paraná River. Through exhaustive fieldwork, we could recognize the main structures that characterize the landslide mechanism. Additionally, new data provided by six geotechnical boreholes helped us to understand the mechanism that triggers the landslides. The observed geomorphic features and geotechnical information suggest that this is a case of Earthflow process. An appropriate interpretation of the type of movement and the identification of the causes, could be used to predict and build suitable engineering works to mitigate the impact of the landslides.
Stilobezzia Kieffer (Diptera: Ceratopogonidae) from the Brazilian Amazon: three new species, redescription of S. (Stilobezzia) maculata Lane and new records
Stilobezzia Kieffer (Diptera: Ceratopogonidae) from the Brazilian Amazon: three new species, redescription of S. (Stilobezzia) maculata Lane and new records
da Silva, Irene M.; Ferreira Keppler, Ruth L.; Cazorla, Carla Gisela
Three new species of Stilobezzia Kieffer, 1911 are described and illustrated from the Brazilian Amazon, two in the nominotypical subgenus Stilobezzia: S. (Stilobezzia) brasiliensis n. sp. and S. (Stilobezzia) campinaranensis n. sp., and one in the subgenus Acanthohelea: S. (Acanthohelea) medialuna n. sp. We also redescribe and re-illustrate S. (Stilobezzia) maculata Lane based on the examination of type material and additional specimens. In addition, S. (Eukraiohelea) proxima Cazorla & Felippe-Bauer, S. (Eukraiohelea) quasielegantula Cazorla & Felippe-Bauer, S. (Stilobezzia) chaconi Macfie, S. (Stilobezzia) glauca Macfie, and S. (Stilobezzia) maculata are recorded for the first time from the state of Amazonas, northern Brazil. The number of Stilobezzia species in Brazilian Amazon increases from 11 to 19.
In Vitro Studies of Pegylated Magnetite Nanoparticles in a Cellular Model of Viral Oncogenesis: Initial Studies to Evaluate Their Potential as a Future Theranostic Tool
In Vitro Studies of Pegylated Magnetite Nanoparticles in a Cellular Model of Viral Oncogenesis: Initial Studies to Evaluate Their Potential as a Future Theranostic Tool
Principe, Gabriel; Lezcano, Virginia Alicia; Tiburzi, Silvina Mabel; Miravalles, Alicia Beatriz; Rivero, Paula Sofia; Montiel Schneider, María Gabriela; Lassalle, Verónica Leticia; González Pardo, María Verónica
Magnetic nanosystems represent promising alternatives to the traditional diagnostic and treatment procedures available for different pathologies. In this work, a series of biological tests are proposed, aiming to validate a magnetic nanoplatform for Kaposi’s sarcoma treatment. The selected nanosystems were polyethylene glycol-coated iron oxide nanoparticles (MAG.PEG), which were prepared by the hydrothermal method. Physicochemical characterization was performed to verify their suitable physicochemical properties to be administered in vivo. Exhaustive biological assays were conducted, aiming to validate this platform in a specific biomedical field related to viral oncogenesis diseases. As a first step, the MAG.PEG cytotoxicity was evaluated in a cellular model of Kaposi’s sarcoma. By phase contrast microscopy, it was found that cell morphology remained unchanged regardless of the nanoparticles’ concentration (1–150 µg mL−1). The results, arising from the crystal violet technique, revealed that the proliferation was also unaffected. In addition, cell viability analysis by MTS and neutral red assays revealed a significant increase in metabolic and lysosomal activity at high concentrations of MAG.PEG (100–150 µg mL−1). Moreover, an increase in ROS levels was observed at the highest concentration of MAG.PEG. Second, the iron quantification assays performed by Prussian blue staining showed that MAG.PEG cellular accumulation is dose dependent. Furthermore, the presence of vesicles containing MAG.PEG inside the cells was confirmed by TEM. Finally, the MAG.PEG steering was achieved using a static magnetic field generated by a moderate power magnet. In conclusion, MAG.PEG at a moderate concentration would be a suitable drug carrier for Kaposi’s sarcoma treatment, avoiding adverse effects on normal tissues. The data included in this contribution appear as the first stage in proposing this platform as a suitable future theranostic to improve Kaposi’s sarcoma therapy.
¿El ciudadano que resiste o el sujeto que obedece? Tensiones entre la resistencia y la obediencia en la filosofía de Spinoza
¿El ciudadano que resiste o el sujeto que obedece? Tensiones entre la resistencia y la obediencia en la filosofía de Spinoza; The citizen who resists or the subject who obeys: Tensions between resistance and obedience in Spinoza’s philosophy
Rozenberg, Antonio David; Ricci Cernadas, Gonzalo
El presente artículo analiza la relación entre obediencia y resistencia en el pensamiento de Baruch Spinoza. El mismo parte de la afirmación hecha por Laurent Bove de que la resistencia es el principio de la libertad política y no la obediencia. Para demostrar la relación contingente y no necesaria que existe entre los términos sustanciales de los cuales trata este artículo, dividimos el mismo en tres partes. La primera parte analiza a la resistencia desde la relación entre deseo e ingenium. La segunda parte se centra en el problema de la obediencia a partir de la figura del súbdito y su relación con el Estado. La tercera y última parte analiza las formas de libertad política en el pensamiento de Spinoza y da cuenta de cómo en la relación entre obediencia y resistencia no implica necesariamente la prioridad de la segunda sobre la primera.; This article analyzes the relationship between obedience and resistance in the thought of Baruch Spinoza. To demonstrate the contingent and not necessary relationship that exists between the terms, the author divides the ar ticle into three par ts. The first par t analyzes resistance from the rela-tionship between desire and ingenium. The second par t focuses on the problem of obedience from the figure of the subject and his relationship with the State. The third and final part analyzes the forms of political freedom in Spinoza’s thought and shows how the relationship bet ween obedience and resistance does not necessarily imply the priority of the second over the first.
Cannabidiol repairs behavioral and brain disturbances in a model of fetal alcohol spectrum disorder
Cannabidiol repairs behavioral and brain disturbances in a model of fetal alcohol spectrum disorder
Gasparyan, Ani; Navarro, Daniela; Navarrete, Francisco; Austrich Olivares, Amaya; Scoma, Ernest R.; Hambardikar, Vedangi D.; Acosta, Gabriela Beatriz; Solesio, María E.; Manzanares, Jorge
Fetal alcohol spectrum disorder (FASD) includes neuropsychiatric disturbances related to gestational and lactational ethanol exposure. Available treatments are minimal and do not modulate ethanol-induced damage. Developing animal models simulating FASD is essential for understanding the underlying brain alterations and searching for efficient therapeutic approaches. The main goal of this study was to evaluate the effects of early and chronic cannabidiol (CBD) administration on offspring exposed to an animal model of FASD. Ethanol gavage (3 g/kg/12 h, p.o.) was administered to C57BL/6 J female mice, with a previous history of alcohol consumption, between gestational day 7 and postnatal day 21. On the weaning day, pups were separated by sex, and CBD administration began (30 mg/kg/day, i.p.). After 4–6 weeks of treatment, behavioral and neurobiological changes were analyzed. Mice exposed to the animal model of FASD showed higher anxiogenic and depressive-like behaviors and cognitive impairment that were evaluated through several experimental tests. These behaviors were accompanied by alterations in the gene, cellular and metabolomic targets. CBD administration normalized FASD model-induced emotional and cognitive disturbances, gene expression, and cellular changes with sex-dependent differences. CBD modulates the metabolomic changes detected in the hippocampus and prefrontal cortex. Interestingly, no changes were found in mitochondria or the oxidative status of the cells. These results suggest that the early and repeated administration of CBD modulated the long-lasting behavioral, gene and protein alterations induced by the FASD model, encouraging the possibility of performing clinical trials to evaluate the effects of CBD in children affected with FASD.
A century of parasitology in fisheries and aquaculture
A century of parasitology in fisheries and aquaculture
Timi, Juan Tomas; Buchmann, Kurt
Fish parasitological research associated with fisheries and aquaculture has expanded remarkably over the past century. The application of parasites as biological tags has been one of the fields in which fish parasitology has generated new insight into fish migration and stock assessments worldwide. It is a well-established discipline whose methodological issues are regularly reviewed and updated. Therefore, no concepts or case-studies will be repeated here; instead, we summarize some of the main recent findings and achievements of this methodology. These include the extension of its use in hosts other than bony fishes; the improvements in the selection of parasite tags; the recognition of the host traits affecting the use of parasite tags; and the increasingly recognized need for integrative, multidisciplinary studies combining parasites with classical methods and modern techniques, such as otolith microchemistry and genetics. Archaeological evidence points to the existence of parasitic problems associated with aquaculture activities more than a thousand years ago. However, the main surge of research within aquaculture parasitology occurred with the impressive development of aquaculture over the past century. Protozoan and metazoan parasites, causing disease in domesticated fish in confined environments, have attracted the interest of parasitologists and, due to their economic importance, funding was made available for basic and applied research. This has resulted in a profusion of basic knowledge about parasite biology, physiology, parasite-host interactions, life cycles and biochemistry. Due to the need for effective control methods, various solutions targeting host-parasite interactions (immune responses and host finding), genetics and pharmacological aspects have been in focus.
Modelling relative abundance of Oligoryzomys flavescens, an Orthohantavirus reservoir, in an endemic hantavirus pulmonary syndrome zone
Modelling relative abundance of Oligoryzomys flavescens, an Orthohantavirus reservoir, in an endemic hantavirus pulmonary syndrome zone
Vadell, María Victoria; Gonzalez Fischer, Carlos Maria; Codesido, Mariano; Carbajo, Anibal Eduardo; Bilenca, David Norberto; Gomez Villafañe, Isabel Elisa
Hantavirus pulmonary syndrome (HPS) is a zoonotic emerging infectious disease caused by New World orthohantaviruses (family Hantaviridae) hosted by rodents of the family Cricetidae. In Argentina, one of its main hosts is the sigmodontine rodent Oligoryzomys flavescens, a widely distributed mouse of the Pampas, Delta and Espinal ecoregions of central-east Argentina. Because the abundance of the reservoir and its proportion in the rodent community affects both virus prevalence and human exposure risk, its estimation throughout its known geographical distribution is of key importance for the design of public health strategies to prevent HPS. The aim of this study was therefore to model the relative abundance of O. flavescens in most of the Pampas ecoregion within Buenos Aires Province, Argentina, where hantavirus pulmonary syndrome is endemic. To do this we used owl-pellet samples collected between 2006 and 2008 from 51 sites distributed throughout most of Buenos Aires province. Mammalian prey in each pellet was identified to the lowest possible taxonomic level by examination of the skulls, dentaries and molars. We modelled the frequency of O. flavescens found in each sample as a function of climatic, environmental, and topographic data of each site. The two best models were applied to a Geo referential Information System to build maps of estimated frequency (as a proxy of relative abundance) within Buenos Aires province. Estimated relative abundance of O. flavescens in Buenos Aires province was significantly associated with annual mean temperature, annual precipitation and presence of freshwater bodies, and varied among sub-regions, with the Inland and Rolling Pampas being the regions with highest frequencies. Knowing in which areas O. flavescens abundance is expected to be higher can be used to concentrate limited sanitary efforts in those areas that are most needed in order to reduce transmission and increase detection.
A New Carleman Inequality for a Linear Schrödinger Equation on Some Unbounded Domains
A New Carleman Inequality for a Linear Schrödinger Equation on Some Unbounded Domains
Sanchez Fernandez de la Vega, Constanza Mariel; de Teresa, Luz; Torres, Pablo Andres
This article presents a new Carleman inequality for a linear Schrödinger equation which is suitable for both bounded and unbounded domains. We characterize the conditions on the auxiliary function necessary to obtain the global inequality. The novelty of this result is the construction of the auxiliary function on some unbounded domains and for a corresponding valid control region ω. As a consequence, we prove some results on the controllability of a linear Schrödinger equation on unbounded domains.
Tripartite networks show that keystone species can multitask
Tripartite networks show that keystone species can multitask
Timóteo, Sérgio; Albrecht, Jörg; Rumeu, Beatriz; Norte, Ana C.; Traveset, Anna; Frost, Carol M.; Marchante, Elizabete; López Núñez, Francisco A.; Peralta, Guadalupe; Memmott, Jane; Olesen, Jens M.; Costa, José M.; da Silva, Luís P.; Carvalheiro, Luísa G.; Correia, Marta; Staab, Michael; Blüthgen, Nico; Farwig, Nina; Hervías Parejo, Sandra; Mironov, Sergei; Rodríguez Echeverría, Susana; Heleno, Ruben
Keystone species are disproportionately important for ecosystem functioning. While all species engage in multiple interaction types with other species, keystone species importance is often defined based on a single dimension of their Eltonian niche, that is, one type of interaction (e.g. keystone predator). It remains unclear whether the importance of keystone species is unidimensional or if it extends across interaction types. We conducted a meta-analysis of tripartite interaction networks examining whether species importance in one dimension of their niche is mirrored in other niche dimensions, and whether this is associated with interaction outcome, intimacy or species richness. We show that keystone species importance is positively associated across multiple ecological niche dimensions, independently of abundance, and find no evidence that multidimensionality of keystone species is influenced by the explanatory variables. We propose that the role of keystone species extends across multiple ecological niche dimensions, with important implications for ecosystem resilience and conservation. Read the free Plain Language Summary for this article on the Journal blog.
Tan spot of wheat: Can biological control interact with actual management practices to counteract this global disease?
Tan spot of wheat: Can biological control interact with actual management practices to counteract this global disease?
Reynoso, Agustina; Sautua, Francisco; Carmona, Marcelo Anibal; Chulze, Sofia Noemi; Palazzini, Juan Manuel
Tan spot is a devastating foliar disease of wheat caused by Pyrenophora tritici-repentis, a necrotrophic ascomycete, which causes considerable yield losses worldwide. To control this disease, an integrated management plan must be implemented by the combination of different tools such as the use of wheat varieties with resistance to Tan spot, crop rotation, tillage systems, balanced fertilization and fungicide application. However, there are increasing worldwide restrictions related to the use of chemical products due to environmental and human risks, aggravated by the fact that consumers are demanding food produced in a more environmentally-friendly way. These facts encouraged producers and scientists to exploit the use of native beneficial microorganisms to control phytopathogens of wheat, that can be used as a tool to control Tan spot. This review focuses on the combination of microorganisms with different management practices to produce wheat in a more sustainable way.
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