151 research outputs found
Microorganismal Cues Involved in Host-Location in Asilidae Parasitoids
Parasitoids are organisms that kill their host before completing their development. Typical parasitoids belong to Hymenoptera, whose females search for the hosts. But some atypical Diptera parasitoids also have searching larvae that must orientate toward, encounter, and accept hosts, through cues with different levels of detectability. In this work, the chemical cues involved in the detection of the host by parasitoid larvae of the genus Mallophora are shown with a behavioral approach. Through olfactometry assays, we show that two species of Mallophora orient to different host species and that chemical cues are produced by microorganisms. We also show that treating potential hosts with antibiotics reduces attractiveness on M. ruficauda but not to M. bigoti suggesting that endosymbiotic bacteria responsible for the host cues production should be located in different parts of the host. In fact, we were able to show that M. bigoti is attracted to frass from the most common host. Additionally, we evaluated host orientation under a context of interspecific competence and found that both parasitoid species orient to Cyclocephaala signaticollis showing that host competition could occur in the field. Our work shows how microorganisms mediate orientation to hosts but differences in their activity or location in the host result in differences in the attractiveness of different cues. We show for the first time that M. bigoti behaves similar to M. ruficauda extending and reinforcing that all Mallophora species have adopted a parasitoid lifestyle.Fil: Castelo, Marcela Karina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Crespo, José Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentin
Compensatory mechanisms during development contribute to overcome intraspecific competition in a dipteran solitary ectoparasitoid with larval active host seeking behaviour
1. Superparasitism has been rendered many times as detrimental for fitness, although there are examples in which the competing winning larvae compensate for its development. Here, we studied if, in the host-parasitoid system Cyclocephala signaticollis (Coleoptera: Scarabaeidae) – Mallophora ruficauda (Diptera: Asilidae), larvae have compensatory mechanisms during development to overcome competition. 2. Through a combination of behavioural and artificial parasitism protocols, we investigated if host instar or time between parasitism events influences the probability of a larva winning the competition. In addition, we studied the effect that superparasitism has in terms of some fitness traits like sex ratio, size, and shape. 3. Our results showed that M. ruficauda has compensatory mechanisms like differential larval survival according to host availability. In addition, we found that as the time between parasitism events increased, the second larva lowers its chance to win the competition in favour of the first arriving larva. Larvae under competition develop at a similar rate compared to larvae that had not experienced competition for hosts. Finally, our results show that wing shape is different between groups, and this could influence flight and courtship. 4. Our study suggests that superparasitism in M. ruficauda is an advantageous strategy under some circumstances although it might influence adult performance with flight related behaviours.Fil: Crespo, José Emilio. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Castelo, Marcela Karina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin
Diving lice: The exception to the rule that there are no insects in the (deep) ocean
Insects are present in virtually all possible habitats on the mainland but virtually absent in the ocean which constitutes 90% of the biosphere. Only a few species are present in the sea, but remaining at the surface, salt marshes, estuaries, or shallow waters. Remarkably, a group of species manages to endure long immersion periods in the open sea, as well as deep dives, i.e. seal lice. We discuss here some of the adaptations that allow seal lice to cope with the amphibious habits of their hosts and how they can help understanding why are insect so rare in the ocean.Fil: Leonardi, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; ArgentinaFil: Crespo, José Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Soto, Florencia Anabella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; ArgentinaFil: Lazzari, Claudio R.. Universite de Tours; Francia. Centre National de la Recherche Scientifique; FranciaThe 1st International Electronic Conference on EntomologySuizaInsects JournalMultidisciplinary Digital Publishing Institut
Characterization of volcanic structures using ground penetrating radar and additional inverse modelling: Multidisciplinary geophysical investigation in the Timanfaya National Park (Spain)
—A ground penetrating radar survey is presented
over a recent lava flow at the volcanic area of Timanfaya
National Park (Canary Island, Spain). The purpose was to locate
lava tubes into the lava flow through the combination of field and
simulated data. Different modelling strategies were used for the
analysis and knowledge of the signal behaviour. Finite-difference
time-domain algorithm was considered for simulations, and the
pattern of reflections generated from previously known volcanic
structures were characterized. After the characterization of the
radar-wave response, the interpretation achieved was applied
over the field data acquired at other non-studied area in which
different lava tubes were recognized.Authors thanks to the financial support of the National
Parks Network of the Spanish Ministry of Environment and
Rural and Marine Affairs (320/2011 – project “Caracterización
estructural del Parque Nacional de Timanfaya mediante uso
combinado de técnicas y métodos geodésicos y geofísicos”.
The staff of National Park of Timanfaya is also acknowledged,
as well as the Applied Geotechnologies research group from
the University of Vigo for providing the RAMAC/GPR
equipment. Additionally, this study is a contribution to the EU
funded COST Action TU-1208.Peer reviewe
Tipificación de Statice dichotoma Cav. (Plumbaginaceae)
A lectotype and an epitype are here designated for Statice dichotoma Cav. (Plumbaginaceae), an endemic taxon from the central part of the Iberian Peninsula, which is currently named Limonium dichotomum (Cav.) Kuntze.Se designan un lectótipo y un epítipo para Statice dichotoma Cav. (Plumbaginaceae), un taxon endémico del centro de la península Ibérica, actualmente denominado Limonium dichotomum (Cav.) Kuntze
SeDeLo: Using semantics and description logics to support aided clinical diagnosis.
Automated medical diagnosis systems based on knowledge-oriented descriptions have gained momentum with the emergence of semantic descriptions. The objective of this paper is to propose a normalized design that solves some of the problems which have been detected by authors in previous tools. The authors bring together two different technologies to develop a new clinical decision support system: description logics aimed at developing inference systems to improve decision support for the prevention, treatment and management of illness and semantic technologies. Because of its new design, the system is capable of obtaining improved diagnostics compared with previous efforts. However, this evaluation is more focused in the computational performance, giving as result that description logics is a good solution with small data sets. In this paper, we provide a well-structured ontology for automated diagnosis in the medical field and a three-fold formalization based on Description Logics with the use of Semantic Web technologiesThis work is supported by the Spanish Ministry
of Industry, Tourism, and Commerce under the project TRAZAMED
(IPT 090000 2010 007).Publicad
PSA-NCAM is expressed in immature, but not recently generated, neurons in the adult cat cerebral cortex layer II
Neuronal production persists during adulthood in the dentate gyrus and the olfactory bulb, where substantial numbers of immature neurons can be found. These cells can also be found in the paleocortex layer II of adult rodents, but in this case most of them have been generated during embryogenesis. Recent reports have described the presence of similar cells, with a wider distribution, in the cerebral cortex of adult cats and primates and have suggested that they may develop into interneurons. The objective of this study is to verify this hypothesis and to explore the origin of these immature neurons in adult cats. We have analyzed their distribution using immunohistochemical analysis of the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) and their phenotype using markers of mature neurons and different interneuronal populations. Additionally, we have explored the origin of these cells administering 5′bromodeoxyuridine (5′BrdU) during adulthood. Immature neurons were widely dispersed in the cerebral cortex layers II and upper III, being specially abundant in the piriform and entorhinal cortices, in the ventral portions of the frontal and temporoparietal lobes, but relatively scarce in dorsal regions, such as the primary visual areas. Only a small fraction of PSA-NCAM expressing cells in layer II expressed the mature neuronal marker NeuN and virtually none of them expressed calcium binding proteins or neuropeptides. By contrast, most, if not all of these cells expressed the transcription factor Tbr-1, specifically expressed by pallium-derived principal neurons, but not CAMKII, a marker of mature excitatory neurons. Absence of PSA-NCAM/5'BrdU colocalization suggests that, as in rats, these cells were not generated during adulthood. Together, these results indicate that immature neurons in the adult cat cerebral cortex layer II are not recently generated and that they may differentiate into principal neurons.Ministerio de Ciencia e Innovación BFU2009-12284/BF
Geotechnical and geomechanical characterization of the fault gouge of the Alhama de Murcia active fault, SE Spain
Here we present the results of the mechanical and mineralogical study of the fault rock of the Alhama de Murcia fault. This fault is one of the most active faults in the Iberian Peninsula. It shows segments partially formed by exhumed fine grained fault rocks (fault gouge FG) with a thickness of more than 50 m developed mainly in a brittle regime. Several strength and strain tests have been carried out, both in-situ and in laboratory, considering different stress orientations in relation to the tectonic fabric. Undisturbed samples encountered from two fault observatory boreholes drilled near Lorca, (FAM-1 and FAMSIS-IGN, of 174 and 40 m depth, respectively) has been used for the laboratory tests. The FG shows a hard soil and soft rock like mechanical behavior with uniaxial compressive strength 1.19) for planes unfavourably oriente
Comparative study of imputation algorithms applied to the prediction of student performance
[Abstract]: Student performance and its evaluation remain a serious challenge for education systems. Frequently, the recording and processing of students’ scores in a specific curriculum have several f laws for various reasons. In this context, the absence of data from some of the student scores undermines the efficiency of any future analysis carried out in order to reach conclusions. When this is the case, missing data imputation algorithms are needed. These algorithms are capable of substituting, with a high level of accuracy, the missing data for predicted values. This research presents the hybridization of an algorithm previously proposed by the authors called adaptive assignation algorithm (AAA), with a well-known technique called multivariate imputation by chained equations (MICE). The results show how the suggested methodology outperforms both algorithms.Ministerio de Economía y Competitividad ; AYA2014-57648-PAsturias. Consejería de Economía y Empleo ; FC-15-GRUPIN14-01
School of Sciences embraces programming (Exactas Programa): reaching every corner of Science
Las herramientas computacionales juegan un rol cada vez mas importante en casi todas las disciplinas cientificas y tecnologicas, asi como el sector gubernamental y la industria. El saber programar, por otro lado, no ha sido formalmente incorporado como conocimiento requerido para los graduados de las distintas instituciones educativas, tales como laFacultad de Ciencias Exactas y Naturales (o simplemente Exactas como la llamamos) de la Universidad de Buenos Aires en Argentina. Esta fuerte contradiccion podria llevarnos a que los futuros cientificos tengan una pobre preparacion en terminos de las herramientas computacionales que deberian utilizar en sus tareas diarias. Para solucionar este complejo escenario, es necesario incorporar el potencial que ofrece la Computacion en las diferentes carreras. Saber como escribir un programa para resolver un problema es mucho que aprender a programar, es una aproximacion activa que ayuda a los estudiantes a organizar su razonamiento logico en forma de pasos claros y concisos.Ayuda a consolidar el entendimiento del problema en si, mas alla de la disciplina de que se trate. Nuestro objetivo al crear Exactas Programa es proveer los elementosesenciales de programacion, sin introducir una asignatura completa en su plan de estudios ya exigente, buscando que los estudiantes puedan incorporar a la computadora como una herramienta practica que los asista en la resolucion de problemas.Con este objetivo en mente, hemos formado un equipo de trabajo conformado por profesores, auxiliares, estudiantes de doctorado de diferentes disciplinas para asegurar una mirada interdisciplinaria que combine diferentes motivaciones para el uso de la computadora para presentar desafios transversales a las distintas disciplinas. El resultado, ExactasPrograma, no es un curso de programacion, es un taller de resolucion de problemas en el que la computadora tiene el rol principal.En este trabajo, compartimos la estructura del curso, los detalles de las actividades incluidas y algunas lecciones que aprendimos luego de haber dictado el taller en cinco oportunidades.Computational tools play an increasingly central role in almost all scientific and technological disciplines, as well as throughout both Government and Industry sectors. Programming skills, on the contrary, have not been formally incorporated as required knowledge for graduates of educational institutions, such as the School of Sciences (or simply Exactas as we call it in Spanish) of the Universidad de Buenos Aires in Argentina. This sharp contradiction could lead to the poor preparation of future scientists in terms of the necessary use of computational tools in their daily activities. To address this skill gap, it is necessary to incorporate the great potential of computing into the different curricula. Knowing how to write a program to solve a problem is far more than learning to write a piece of code; it is an active learning approach that helps students organize the logical reasoning steps and fosters a solid understanding of the subject matter, regardless of the discipline. Our objective in creating Exactas Programs was to provide the essential elements of programming- without introducing another stumbling block in their already challenging degree programs- so that students of any major can incorporate the computer as a practical problem solving tool. With this objective in mind, we formed a working group of professors, teaching assistants, and doctoral students of different scientific backgrounds to ensure a multidisciplinary initiative that combines different motivations and contexts for the use of the computer in addressing challenges that traverse all majors. The result, Exactas Programs, is not a programming course; it is a short problem-solving workshop in which the computer is the central tool. In this work, we share our proposal’s structure, the details of some of the activities that comprise it, and the lessons learned after five editions of the workshop.Fil: López y Rosenfeld, Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación; ArgentinaFil: Mocskos, Esteban Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación; ArgentinaFil: González Lebrero, Mariano Camilo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Crespo, José Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Arrar, Mehrnoosh. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Caridi, Délida Inés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Cálculo; ArgentinaFil: Sued, Raquel Mariela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Cálculo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
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