Nuevos aportes documentales sobre la cooperación CONICET-CNR

Se aportan nuevos datos documentales sobre   la aplicación de convenios bilaterales CNR‐ CONICET, obtenidos en una visita de estudio al Archivo de Documentación del CNR (diciembre 2012) sobre los proyectos presentados por investigadores de ambas instituciones durante casi 20 años (de 1980 a 1998). Se trata del análisis de 154 formularios presentados al CNR en el período indicado, con análisis por períodos, investigadores, temas y duraciónThe current paper presents the data of the documents concerning the bilateral agreement between CNR and CONICET. The data were collected during a visit to the Documentation Archive of CNR, in December 2012. The documentation refers to the projects implemented by the researchers of both institutes during almost 20 years, from 1980 until 1998. The analysis centred on the 154 forms submitted to CNR in the mentioned period, with an analysis for different periods, researchers, subjects, and durationFil: Lertora Mendoza, Celina Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

SALUD Y CONDICIONES DE VIDA DE ESCOLARES EN BARILOCHE

¿Cuál es el estado de salud de los niños en edad escolar de la ciudad de Bariloche? Las condiciones socioeconómicas y culturales de los distintos sectores sociales, ¿guardan relación con su estado de salud? En este sentido, ¿existen factores de riesgo para la salud asociados a ciertas condiciones de vida? Éstos son algunos de los interrogantes expresados por un grupo de médicos pediatras de Bariloche a partir de los cuales se decidió llevar adelante este estudio, junto con integrantes del Departamento de Estadística del Centro Regional Universitario Bariloche de la Universidad Nacional del Comahue

Monte Carlo Generation of Bohmian Trajectories

We report on a Monte Carlo method that generates one-dimensional trajectories for Bohm's formulation of quantum mechanics that doesn't involve differentiation or integration of any equations of motion. At each time, t=n\delta t (n=1,2,3,...), N particle positions are randomly sampled from the quantum probability density. Trajectories are built from the sorted N sampled positions at each time. These trajectories become the exact Bohm solutions in the limits N->\infty and \delta t -> 0. Higher dimensional problems can be solved by this method for separable wave functions. Several examples are given, including the two-slit experiment.Comment: 10 pages, 6 figure

Doubly Differential Cross Sections of Low-Energy Electrons Emitted in the Ionization of Molecular Hydrogen by Bare Carbon Ions

We have measured the double differential cross sections (DDCS) (d2σ/dεedΩe) of low-energy electron emission in the ionization of H2 bombarded by bare carbon ions of energy 30 MeV. The energy and angular distributions of the electron DDCS have been obtained for 12 different emission angles and for electron energies varying between 0.1 and 300 eV. We have also deduced the single differential and total ionization cross section from the measured DDCS. The data have been compared with the predictions of first Born approximations and the CDW-EIS (continuum distorted wave–eikonal initial state) model. The CDW-EIS model provides an excellent agreement with the data. [S1050-2947~96!10109-8

Dual community assembly processes in dryland biocrust communities

1. Biocrusts are critical components of drylands where they regulate a wide range of ecosystem functions, however, their response to the world‐wide phenomenon of shrub encroachment and to livestock grazing, the most extensive land use in drylands, is not well studied. Grazing by livestock and increases in shrub cover could influence biocrust communities directly via trampling or shading, or indirectly, by altering biotic interactions amongst biocrust taxa. The extent of these changes in biocrust cover, diversity and composition are poorly known. 2. We used linear models and structural equation modelling to examine the direct effects of grazing and shrubs on biocrust community composition and the indirect effects mediated by changes in species interactions. 3. Biocrust richness and cover increased with increasing shrub cover at the site level. This pattern occurred despite the negative response we found (lower cover and richness) under shrub patches versus open areas, which was consistent irrespective of the grazing level. Functional diversity and evenness were similar between shrubs and open at low grazing intensity, but at high grazing functional diversity was greater in the open. Competition between biocrust species was an important driver of their community assembly irrespective of shrub cover, grazing intensity or patch type. Structural equation models showed that the effects of grazing and shrub cover on functional evenness, functional diversity and richness were controlled by biotic interactions within the shrub microsites. In the open, however, these effects were either direct or mediated by changes in cover. 4. Biocrust cover, species richness and functional diversity increase with shrub cover at the site scale, despite the negative effects at the microsite level. We demonstrate here that drivers of community assembly differ markedly at small spatial scales. Though biocrust communities were directly driven by environmental filtering in the open, biotic interactions played a fundamental role in their assembly when growing beneath shrubs.Both authors acknowledge support from the Hermon Slade Foundation Grant no. HSF13/1. S.S. was supported by the Spanish Government under the Ramón y Cajal contract (RYC-2016-20604)

The effect of a large expansion of pre-primary school facilities on preschool attendance and maternal employment

We provide evidence on the impact of a large construction of pre-primary school facilities in Argentina. We estimate the causal impact of the program on pre-primary school attendance and maternal labor supply. Identification relies on a differences-in-differences strategy where we combine differences across regions in the number of facilities built with differences in exposure across cohorts induced by the timing of the program. We find a sizeable impact of the program on pre-primary school participation among children aged between 3 and 5. In fact, we cannot reject the null hypothesis of a full take-up of newly constructed places. In addition, we find that the childcare subsidy induced by the program increases maternal employment and that this effect is in line with the one previously found for the US.

Rancang Bangun Peralatan Uji Karakteristik Pompa Sentrifugal Susunan Seri dan Paralel untuk Pembelajaran Sistem Pompa dan Perpipaan

In shipping industry, especially on  ships, centrifugal pumps are used in piping systems. Pumps are the most component used for fluid transferring process of piping systems such as ballast systems, bilga systems, fire fighting systems, sanitary systems, fresh water systems and engine cooling systems. The used of pump capacity may varies depending on system requirements. On pump operation, especially centrifugal pumps can be used as a single, series, or parallel according to flow requirements and working pressure (pressure head). The characteristics of centrifugal pumps that are operated in series and parallel can be known through direct pump operation or can be done through the use of a visual aid. The pump operation trainer is designed as a learning aids to determine the characteristics of series and parallel centrifugal pumps. The purpose of this research is to design a model of test equipment for the characteristics of a series and parallel arrangement of centrifugal pumps. The research method is carried out in several stages such as designs, build and testing This research also made a plans for further development of automatic control and monitoring systemsPada industri perkapalan khususnya pada kapal, pompa sentrifugal digunakan pada sistem perpipaan kapal. Pompa menjadi komponen utama dalam proses pemindahan fluida (fluid transferring) sistem perpipaan seperti sistem ballast, sistem bilga, sistem pemadam kebakaran, sistem sanitary, sistem air tawar dan sistem pendinginan mesin. Besarnya kapasitas pompa yang digunakan bervariasi tergantung kebutuhan sistem. Pada proses pengoperasian pompa, khususnya pompa sentrifugal dapat dilakukan secara tunggal, seri, maupun paralel sesuai kebutuhan aliran (flowrate) dan tekanan kerja (pressure head). Karakteristik pompa sentrifugal yang dioperasikan secara seri dan paralel dapat diketahui melalui pengoperasian pompa secara langsung ataupun dapat dilakukan melalui penggunaan sebuah alat peraga. Alat peraga pengoperasian pompa dirancang secara khusus sebagai media pembelajaran untuk mengetahui karakteristik pompa sentrifugal seri dan paralel. Tujuan dari penelitian ini adalah membuat rancang bangun model peralatan uji karakteristik pompa sentrifugal susunan seri dan paralel untuk pembelajaran sistem pompa dan perpipaan kapal. Metode penelitian yang dilakukan melalui beberapa tahapan yaitu membuat rancangan/desain, proses pembuatan alat uji, melakukan uji coba alat yang telah dibuat dan melakukan evaluasi terhadap alat yang telah dibuat dengan melibatkan dosen dan mahasiswa sebagai pengguna alat. Pada penelitian ini juga dibuat rencana pengembangan lanjutan pada sistem kontrol dan monitoring otomati

ASPECTO SOCIOCULTURAL DE LOS PADRES Y DESARROLLO PSICOMOTOR DE NIÑOS DE 0 A 30 MESES DEL CLAS PILLCOMARCA – HUÁNUCO, 2016

Objetivo. Determinar la relación entre el aspecto sociocultural de los padres y el desarrollo psicomotor de niños. Métodos. Se llevó a cabo un estudio correlacional con 91 padres y sus niños de 0 a 30 meses, procedentes del CLAS Pillcomarca – Huánuco, durante el periodo 2016. En la recolección de los datos se utilizaron una guía de entrevista y una guía de observación. Para el análisis inferencial se utilizó la Prueba Chi cuadrada de independencia. Resultados. El 82.4% (75 niños) presentaron desarrollo psicomotor normal. El 76.9% de padres tuvieron estado civil de unión libre, la mayoría (madre=56.0%; padre=65.9%) educación secundaria completa, 56.0% de madres y 96.7% de padres trabajaban, el 100.0% hablaban castellano, la mayoría (madre=80.2%; padre=90,1%) profesaban la religión católica y como cultura huanuqueña, 42.9% de madres indicaron la gastronomía y 39.6% de padres la música. Por otro lado, se encontró relación significativa entre desarrollo psicomotor de niños y estado civil (p≤0.000); grado de instrucción de la madre (p≤0.002) y del padre (p≤0.000); trabajo del padre (p≤0.000) y elemento representativa de la cultura huanuqueña del padre (p≤0.000). Conclusiones. Existe relación significativa entre el desarrollo psicomotor de niños de 0 a 30 meses y el aspecto sociocultural de los padres

Estudio histológico de huevos ováricos partenogenéticos de Moina eugeniae, Olivier 1954

Moina eugeniae is one of the most abundant zooplankton species found in ponds and lakes in Buenos Aires Province. Its importance is due to the common use of cladocerans as food fish. The aim of the present study was to investigate the reproductive structures through histological techniques. Samples were taken with a plankton net (150 μm) from the Calderón lake (Buenos Aires) during Spring 2006. The specimens were anesthetized with CO2 “in situ” and fixed with formaldehyde 4%. Parthenogenetic females in different reproductive stages were selected to perform with them routine histological techniques. No males were identified during our study. The ovaries are pair, secular and disposed dorsally in the body. The oocytes are polyedric with three different stages of maturation: previtellogenic (dense nuclear cromatine), vitellogenic (abundant yolk in cytoplasm and large granules of cromatine in the nucleous) and mature (abundant lipidic drops in cytoplasm). Many of the morphological features observed are similar to those of Daphnia genus. Further investigation is needed to elucidate the reproductive cycle of this species.Instituto de Limnología "Raúl A. Ringuelet