Loxodontomys pikumche (Rodentia, Cricetidae): nueva especie para Argentina

We report the first record of occurrence of Loxodontomys pikumche Spotorno et al., 1998, in the Central Andes of Argentina. We briefly describe external characters, skull, karyotype, and habitat; also, we provide general comparisons with the other known species in the genus, L. micropus.Se reporta el primer registro de ocurrencia de Loxodontomys pikumche Spotorno et al., 1998, para los Andes Centrales de Argentina. Se describen brevemente los caracteres externos, morfología craneal, cariotipo y hábitat; además, se ofrece una comparación general con la otra especie conocida en el género, L. micropus.Fil: Novillo, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Ojeda, Agustina Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Ojeda, Ricardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin

Design of a motorcycle mount with integrated roll-and-pitch-torque measurement on a motorcycle simulator

On the new motorcycle simulator developed by the Institute of Automotive Engineering (FZD) of the Technische Universität Darmstadt, a measuring system should be incorporated with the aim of deter-mining the forces generated by the motion of therider. The objective of this thesis is to design a mount for the future simulator capable of measuringthe two main outputsof rider motion: the roll and pitch rider-induced torques. The current simulator of the department located at WIVW measures only the torque around the rolling axis and the used concept does not provide the desired performance nor precision; the solution designed in this thesis should present an improvement in regards to those features as well.In order to come up with the most suitable design, the standard product development proceeding has been followed. First, by defining the demands of the mount on a request list. Next, following an organized creative process, several concepts have been proposed. All the alternatives have been eval-uated in regards to relevant criteria and the most appropriate solution has been chosen. An exhaustive multibody model has been developed using MatLAB/Simulink with Simscape extension in order to analyze the dynamic behavior of the chosen solution under any possible scenario.Finally, a basic CAD of the system has been carried out in order to materialize the constructive solutions that will bring the concept into reality. Other constructive insights have been also treated, like the bearing selection, among others. The selected approach consists on a three-legged surface that is attached to the motion platform of the simulator and serves as a base for the mock-up attachment.The orientation of the legs define the height of two coincident rotating axes(rolling and pitching), creating a mechanism able to rotateits surfacearound a desired center of rotation.When the rotation around those axes is fixed trough meas-uring elements, the rider-induced torques measuring system is enabled. By positioning said CoR at the height of the system’s CoG, most of the measuring imprecisions that presents the current simulator are eliminated, since the greatest part of inertial forces generated by the platform motion have no longer an effect on the measuring dat

Motorcycle frame design and optimization

The objective of this project is to develop the chassis of an electric motorcycle that takes part in the international competition Smart Moto Challenge 2016, showing the work that has been done inside the e-Ride ETSEIB team. It focuses on the design of the frame and the swing arm, their FEM simulation and the manufacturing process to obtain them. Design is done taking in account the different requirements that must accomplish the motorcycle, such as the components that must hold the structure or the desired geometry of the chassis. Final design not only includes the frame and the swing arm, but also all the commercial parts that form the chassis assembly: wheels, fork, suspension, brakes, bearings, handlebar, footrests... The FEM study includes stiffness simulations of the frame and the swing arm in order to prove the dynamic properties of the motorcycle. It also has been considered several resistance simulations of the parts of the chassis that receive the higher loads to guarantee that they will resist any unforeseen critical stresses during the life of the motorcycle. All the simulations and the consequent optimization process have been done with the aim of keeping the weight of the tested parts as low as possible. The manufacturing process of both frame and swing arm is explained with detail and has been proved by the manufacturing sponsor that is going to build these parts

Alternative diff-in-diffs estimators with several pretreatment periods

This paper deals with the identification of treatment effects using difference-in-differences estimators when several pretreatment periods are available. We define a family of identifying nonnested assumptions that lead to alternative difference-in-differences estimators. We show that the most usual difference-in-differences estimators imply equivalence conditions for the identifying nonnested assumptions. We further propose a model that can be used to test multiple equivalence conditions without imposing any of them. We conduct a Monte Carlo analysis and apply our approach to several recent papers to show its practical relevance.We gratefully acknowledge the financial support by the Ministerio Economía y Competitividad (Spain), through grant ECO2015-65204-P. Ricardo Mora also acknowledges the financial support from the grants MDM 2014-0431, and MadEco-CM (S2015/HUM-3444)

New records of Tympanoctomys barrerae (Rodentia, Octodontidae)

La rata vizcacha colorada, Tympanoctomys barrerae, presenta un rango geográfico reducido y ocurre a modo de parches poblacionales aislados y asociados a salares. En esta nota reportamos nuevos registros de distribución para las provincias de San Juan, Neuquén y La Pampa, y ampliamos considerablemente la distribución septentrional (340 km) y meridional (279 km) de la especie. Este conjunto de datos, sumado al registro fósil recientemente descubierto, extiende notablemente la distribución pasada y reciente de este género.The red vizcacha rat, Tympanoctomys barrerae, shows a reduced geographic range and a patchy distribution of its populations associated to salt basins. We report new distributional records for San Juan, Neuquén and La Pampa provinces, with a significant extension of their septentrional (340 km) and meridional (279 km) distribution. These set of data, coupled with the fossil record recently discovered, expand the past and actual distribution for the genera considerably.Fil: Ojeda, Agustina Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Gallardo Narcisi, Milton Hermes. Universidad Austral; ChileFil: Mondaca, Fredy. Universidad Austral; ChileFil: Ojeda, Ricardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin

Estocásticos en el segundo grado de educación especial

El estudio enfoca el tratamiento de estocásticos en el segundo grado de educación especial. La perspectiva teórica considera aspectos en el orden epistemológico, el cognitivo y el social. La investigación, de carácter cualitativo, sigue los lineamientos del órgano operativo y de la célula de análisis. Se caracterizan los procesos de enseñanza realizados en aula alterna, para lo cual se juzga esencial el tipo de actividades propuestas y el análisis del papel del habla. Participan en el estudio niños con diagnósticos de lento aprendizaje y de problemas de lenguaje. El examen de la propuesta institucional para el grado educativo en cuestión resulta en un tratamiento de estocásticos insuficiente, por lo que se han incluido para el aula actividades relativas a la idea de azar. Referente a las actividades en aula alterna, se realizó la distinción de la situación de referencia y el signo, y de las ideas fundamentales. Se notaron, tanto en aula como en las entrevistas, el uso de esquemas compensatorios

Flea parasites of small mammals in the Monte Desert biome in Argentina with new host and locality records

Fleas associated with small mammals from the Argentinean Monte Desert, were examined. The research was carried out in Ñacuñán Biosphere Reserve (34°02´S, 67°58´W), in the Chaqueña Biogeographic Subregion of the Neotropical Region. Mammal species trapped were as follows: Rodentia, Muridae, Sigmodontinae: Akodon molinae Contreras, 1968 (N = 44), Graomys griseoflavus (Waterhouse, 1837) (N = 15), Calomys musculinus (Thomas, 1913) (N = 12), and Eligmodontia typus F. Cuvier, 1837 (N = 7); Didelphiomorphia, Didelphidae, Mamorsinae: Thylamys pusillus (Desmarest, 1804) (N = 1). A total of 236 fleas were collected: Stephanocircidae, Craneopsyllinae: Craneopsylla minerva wolffhuegeli (Rothschild, 1909); Rhopalopsyllidae, Rhopalopsyllinae: Polygenis (Polygenis) bohlsi bohlsi (Wagner, 1901), Polygenis (Polygenis) platensis cisandinus (Jordan, 1939) and Polygenis (Neopolygenis) puelche Del Ponte, 1963; Rhopalopsyllidae, Parapsyllinae: Ectinorus (Ectinorus) barrerai Jordan, 1939. High values of total mean abundance (MA = 2.99) and total prevalence (P = 73.41%) were obtained. A. molinae (MA = 3.14; P = 93.18; flea specific richness S = 5; Shannon specific diversity index H = 1.25) and G. griseoflavus (MA = 6.40; P = 100%; S = 5; H = 0.76) showed the highest values of the infestation parameters. No fleas were collected from E. typus, possibly because of its habits. Fleas associated with T. pusillus are reported for the first time. Our collections extend the western limits of the distribution of both P. (N.) puelche and P. (P.) b. bohlsi. In addition, new host species are reported for every flea species and subspecies, and seven host-flea associations are mentioned for the first time.Fil: Lareschi, Marcela. Universidade Federal de Minas Gerais; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Ojeda, Ricardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Linardi, Pedro M.. Conselho Nacional de Desenvolvimiento Científico e Tecnológico; Brasi

Concert: Ithacappella

Objetivo: Comparar la eficacia de 3 protocolos de limpieza intraconducto utilizados previo a la cementación de pernos protésicos.Materiales y métodos: A 40 dientes anteriores se les realizó un tratamiento endodóntico en mano, mediante la técnica de condensación lateral. Luego de dos semanas, se realizó la desobturación de los mismos retirando la cantidad de gutapercha que otorgue el espacio necesario para alojar un poste. A continuación, los dientes fueron divididos aleatoriamente en grupos; superficie radicular tratada con clorhexidina (CHX) activado con ultrasonido (US) (grupo I), con clorhexidina activado con instrumental sónico (S) (grupo II), con clorhexidina sin activación (grupo III) y sin ningún tratamiento (grupo IV). Todos los dientes se fracturaron longitudinalmente obteniendo 2 secciones. Se microfotografió el tercio medio del conducto radicular  con microscopio electrónico de barrido (MEB) y se midió la superficie contaminada con detritus usando ImageJ 1.47. Se analizó con test Kruskall-Wallis usando GraphPad-Prism 5.01.Resultados: La mediana del porcentaje de área contaminada del Grupo I fue 20,06%, Grupo II de 19,3%, Grupo III de 36,05% y Grupo IV de 56,45%.Conclusión: Existen diferencias significativas entre los distintos protocolos de limpieza intraconducto en la eficacia de eliminación de detritus del conducto radicular, siendo los protocolos activados más eficientes.Objective: Compare efficacy 3 intracanal cleaning protocols used previous to cementation of prosthetic bolts.Material and Methods: 40 anterior teeth which received endodontic treatment in hand, using the technique of lateral condensation. After two weeks, the unblocking of the anterior teeth was carried out removing the amount of gutta-percha that grants the necessary space to accommodate a post. Then, the teeth were randomly divided into groups; root surface treated with chlorhexidine (CHX) activated by ultrasound (US) (group I), chlorhexidine activated with sonic instrument (S) (group II), chlorhexidine without activation (group III) and chlorhexidine without treatment (group IV). All teeth were fractured longitudinally getting 2 sections. The middle third of the root canal was micro photographed with a scanning electron microscope (SEM) and the contaminated surface was measured using detritus ImageJ 1.47. It was analyzed with Kruskal-Wallis-test using GraphPad Prism 5.01.Results: The median percentage of contaminated area of the Group I was 20.06%, Group II 19.3%, Group III 36.05% and Group IV 56.45%.Conclusion: There are significant differences among different intracanal cleaning protocols in the removal efficiency of detritus from the root canal, being the activated protocols the most effective ones

Evolution of the largest mammalian genome

The genome of the red vizcacha rat (Rodentia, Octodontidae, Tympanoctomys barrerae) is the largest of all mammals, and about double the size of their close relative, the mountain vizcacha rat Octomys mimax, even though the lineages that gave rise to these species diverged from each other only about five million years ago. The mechanism for this rapid genome expansion is controversial, and hypothesized to be a consequence of whole genome duplication or accumulation of repetitive elements. To test these alternative but nonexclusive hypotheses, we gathered and evaluated evidence from whole transcriptome and whole genome sequences of T. barrerae and O. mimax. We recovered support for genome expansion due to accumulation of a diverse assemblage of repetitive elements, which represent about one half and one fifth of the genomes of T. barrarae and O. mimax, respectively, but we found no strong signal of whole genome duplication. In both species, repetitive sequences were rare in transcribed regions as compared to the rest of the genome, and mostly had no close match to annotated repetitive sequences from other rodents. These findings raise new questions about the genomic dynamics of these repetitive elements, their connection to widespread chromosomal fissions that occurred in the T. barrerae ancestor, and their fitness effects ? including during the evolution of hypersaline dietary tolerance in T. barrerae.Fil: Evans, Ben J.. Mc Master University; CanadáFil: Upham, Nathan S.. Mc Master University; Canadá. Field Museum of Natural History; Estados Unidos. University of Yale; Estados UnidosFil: Golding, G. Brian. Mc Master University; CanadáFil: Ojeda, Ricardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Ojeda, Agustina Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin