Ciencia y Tecnología

Comunicación, energía y construcción: los pilares alemanes en el desarrollo tecnológico de Buenos Aires

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Comunicación, energía y construcción: los pilares alemanes en el desarrollo tecnológico de Buenos Aires Mendez, Patricia Susana Este texto explica la historia de aquellas empresas de origen alemán instaladas en la Argentina de fines del siglo XIX y que perduraron hasta la década del 40. El análisis se centra en función de la productividad que tuvieron y su relación con la construcción; fundamentalmente, apoyadas en tres importantes renglones en el desarrollo tecnológico del país: la energía eléctrica, las comunicaciones y las construcciones en hormigón armado. Nombres como los de CATE, GEOPÉ, Dykerdoff and Widman y la Siemens en sus tres facetas se detallan desde su nacimiento, producción y obras realizadas en la ciudad de Buenos Aires.

Educación terapéutica de las personas con diabetes tipo 2

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Educación terapéutica de las personas con diabetes tipo 2 Gagliardino, Juan Jose; Assad, Daniel; Gagliardino, Gabriel G.; Lahera, Elba; Rizzutti, Liliana; Zufriategui, Zulma Desde el capítulo 1 hemos venido diciendo que la diabetes mellitus (DM) es una enfermedad crónica que requiere tratamiento permenente a partir del momento de su diagnóstico. Ya en 1922 lo destacaba el Profesor Joslin y recientemente lo confirmaron diversos estudios previamente mencionados como Malmo, DCCT, UKPDS, DaQin, DPP2: “la educación de las personas con o en riesgo de desarrollar diabetes, es un componente esencial de las estrategias de prevención y tratamiento.”

"Computer, please, tell me what I have to do...": An approach to agent-aided application composition

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"Computer, please, tell me what I have to do...": An approach to agent-aided application composition Campo, Marcelo Ricardo; Diaz Pace, Jorge Andres; Trilnik, Federico U. The process of starting to use any reuse technology is usually one of the most frustrating factors for novice users. For this reason, tools able to reduce the learning curve are valuable to augment the potential of the technology to rapidly build new applications. In this work, we present Hint, an environment for assisting the instantiation of Java applications based on software agents technology. Hint is built around a software agent that has the knowledge about how to use a reusable asset and, using this knowledge, is able to propose a sequence of programming activities that should be carried out in order to implement a new application satisfying the functionality the user wants to implement. The most relevant contribution of this work is the use of planning techniques to guide the execution of instantiation activities for a given technology.

Niveles de calidad de vida urbana y el estado de necesidades básicas en servicios e infraestructura

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Niveles de calidad de vida urbana y el estado de necesidades básicas en servicios e infraestructura Discoli, Carlos Alberto; San Juan, Gustavo Alberto; Rosenfeld, Elias; Martini, Irene; Barbero, Dante Andrés; Ferreyro, Carlos; Ramírez Casas, Jimena; Dicroce, Luciano; Dominguez, Cristina El trabajo expone aspectos teórico-conceptuales y resultados de un modelo de calidad de vida urbana (CVU). El mismo considera las interacciones entre los servicios básicos, la infraestructura y los aspectos ambientales, la cobertura y/o área de influencia y la opinión/percepción de los usuarios. Se elaboraron mapas orientados a territorializar y definir el estado de necesidades básicas relacionadas a los servicios urbanos y de infraestructura. Asimismo, se muestran las tendencias en términos de calidad de vida en función de la integración de diferentes aspectos urbanos y de su consolidación. Por último, se realizan algunas consideraciones metodológicas y operativas en cuanto a ventajas y limitaciones que se experimentan en la aplicación del modelo.; This work exposes theoretical-conceptual aspects and results of the quality of urban life model (CVU). It considers the interaction between the basic services, the infrastructure and environmental aspects, the influenced area, and users’ opinion/perception. Maps were elaborated that tend to express geographically and to define the basic necessities state related to the urban and infrastructure services. Tendencies are also shown in terms of life quality in function of different urban aspects integration and of their consolidation. Some methodological and operative considerations are carried out taking into account the advantages and limitations that are experienced in the application of the model.

Una visión global de la respuesta inmune

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Una visión global de la respuesta inmune Geffner, Jorge Raúl El sistema inmune permite que, a pesar de vivir en un ambiente densamente poblado de agentes microbianos potencialmente patógenos, sólo en pocas ocasiones suframos procesos infecciosos evidentes desde el punto de vista clínico. Más aún, cuando esto sucede, la infección suele resolverse con rapidez gracias al desarrollo de una respuesta inmune que integra mecanismos propios de las inmunidades innata y adaptativa...

Inmunidad innata: neutrófilos, macrófagos y células natural killer

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Inmunidad innata: neutrófilos, macrófagos y células natural killer Trevani, Analía Silvina; Geffner, Jorge Raúl; Faimboin, Leonardo Mientras que sólo los linfocitos T y B componen las células de la inmunidad adaptativa, las células de la inmunidad innata comprenden un amplio abanico de tipos celulares. En sentido genérico, puede afirmarse que todas las células del organismo participan en la inmunidad innata, ya que son capaces de mediar diferentes mecanismos antimicrobianos. En el capítulo anterior, definimos la capacidad de los queratinocitos y células epiteliales de los tractos para orquestar una serie de respuestas tendientes a evitar la colonización de las superficies expuestas y eliminar los focos infecciosos que pudieran establecerse.

On limit cycle approximations in the van der Pol oscillator

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On limit cycle approximations in the van der Pol oscillator Padín, Mirta S.; Robbio, Federico I.; Moiola, Jorge Luis; Chen, Guanrong This paper applies bifurcation analysis to the well-known van der Pol oscillator to obtain approximations of its periodic solutions in the nearly sinusoidal regime. A frequency domain method based on harmonic balance approximations is used for small values of the bifurcation parameter. Moreover, a comparison with some other frequency domain approaches is also given. Finally, a total harmonic distortion is computed using the information provided by the frequency domain approach.

Expression of Fluorescent Genes in Trypanosoma cruzi and Trypanosoma rangeli (Kinetoplastida: Trypanosomatidae): Its Application to Parasite-Vector Biology

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Expression of Fluorescent Genes in Trypanosoma cruzi and Trypanosoma rangeli (Kinetoplastida: Trypanosomatidae): Its Application to Parasite-Vector Biology Guevara, Palmira; Dias, Manuel; Rojas, Agustina; Crisante, Gladys; Abreu Blanco, Maria Teresa; Umezawa, Eufrozina; Vazquez, Martin Pablo; Levin, Mariano Jorge; Añez, Nestor; Ramirez, Jose Luis Two Trypanosoma cruzi-derived cloning vectors, pTREX-n and pBs:CalB1/CUB01, were used to drive the expression of green fluorescent protein (GFP) and DsRed in Trypanosoma rangeli Tejera, 1920, and Trypanosoma cruzi Chagas, 1909, isolates, respectively. Regardless of the species, group, or strain, parasites harboring the transfected constructs as either episomes or stable chromosomal integrations showed high-level expression of fluorescent proteins. Tagged flagellates of both species were used to experimentally infect Rhodnius prolixus Stal, 1953. In infected bugs, single or mixed infections of T. cruzi and T. rangeli displayed the typical cycle of each species, with no apparent interspecies interactions. In addition, infection of kidney monkey cells (LLC-MK2) with GFP-T. cruzi showed that the parasite retained its fluorescent tag while carrying out its life cycle within cultured cells. The use of GFP-tagged parasites as a tool for biological studies in experimental hosts is discussed, as is the application of this method for copopulation studies of same-host parasites

Zeolite washcoating onto cordierite honeycomb reactors for environmental applications

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Zeolite washcoating onto cordierite honeycomb reactors for environmental applications Zamaro, Juan Manuel; Ulla, Maria Alicia del H.; Miro, Eduardo Ernesto The preparation conditions to obtain zeolite washcoats with optimum loading and homogeneous distribution are studied for mordenite, ferrierite and ZSM5, The slurry concentration and the number of immersions were combined to obtain different coating thickness and geometry. The solid concentration increases the viscosity of the slurry resulting in an exponential growth of the zeolite loading. In order to obtain more homogeneous washcoatings it is preferable to use diluted suspensions and perform more than one immersion. It was found that the washcoating adherence increases with the decrease in the size of the aggregates deposited on the monolith. This improves the packaging and interaction between particles and facilitates a convenient filling of the surface cordierite macropores, producing a more effective anchorage. In this vein, the order of washcoat stability tested with an ultrasound method is ZSM5 > mordenite > ferrierite. The addition of SiO2 as a binder improves the adherence of the three zeolites under study probably due to an improvement in the interparticle cohesion. The performance of an In-ZSM5 washcoated monolith was tested for the selective reduction of NOx with methane under oxygen excess. It was observed that the activity of the monolithic catalyst was as good as those for the In-ZSM5 powder, which indicates that there are no diffusive restrictions due to coating thickness.

Morfometría de los estadios ninfales de Cornops aquaticum Bruner (1906) (Acrididae: Leptysminae) en Argentina

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Morfometría de los estadios ninfales de Cornops aquaticum Bruner (1906) (Acrididae: Leptysminae) en Argentina; Morphometry of the nymphal stages in Cornops aquaticum (Acrididae: Leptysminae) from Argentina Franceschini, Maria Celeste; Capello, Soledad; Lhano, Marcos G.; Adis, Joachim; de Wysiecki, Maria Laura Cornops aquaticum está ampliamente distribuída en toda Latinoamérica y su ciclo biológico está estrechamente relacionado a Eichhornia crassipes (Mart.) Solms y Eichhornia azurea KUNTH (Pontederiacea). La correcta determinación de los estadíos ninfales de C. aquaticum resulta de fundamental importancia para conocer la estructura de las poblaciones en una determinada región. El objetivo del presente trabajo es evaluar la utilidad de los caracteres morfométricos de las ninfas de C. aquaticum para determinar los distintos estadíos ninfales. Para esto se realizó la cría de ninfas de primer estadío en laboratorio, en Corrientes (N= 29, 28 y 24) y Santa Fé (N= 26, 16), donde se encuentran diferentes condiciones de temperatura e insolación. Las ninfas fueron pesadas y medidas al inicio de la experiencia y después de producida la ecdisis: distancia desde el fastigium hasta el final de las pterotecas o pronotum (A), distancia desde el fastigium hasta el final del abdomen (B), longitus del fémur posterior (H), longitud de la antena (L), número de antenómeros (N° Ant. ) y peso fresco (Peso). La longitud del fémur posterior mostró ser la medida más constante en cada estadío ninfal. En contraste con otros caracteres, presenta la ventaja de ser preciso y constituye además una medida sencilla de registrar cuando se trabaja con un gran número de individuos. Con la información morfométrica, se espera complementar los estudios morfológicos ya existntes y contribuir al conocimiento ecológico de la especie.; Cornops aquaticum is a widely distributed species in Latin America and has a life cycle associated with Eichhornia crassipes (MART.) SOLMS and E. azurea (SW.) KUNTH (Pontederiaceae). The correct determination of the nymphal stages in C. aquaticum is important to study the population structure in a specific region. The purpose of this study is to evaluate if morphometric characters can be used to determine the different nymphal stages in C. aquaticum. For this reason, first-stage nymphs were reared at two localities (Corrientes: N = 29, 28, 24; Santa Fe: N = 26, 16) under different conditions of temperature and insolation. After hatching and after each moult, fresh weight ("Peso") of nymphs was determined and measurements of the following morphometrical characters were taken: distance from fastigium to end of pterothecas or pronotum (A), distance from fastigium to end of abdomen (B), length of hind femur (H), length of antenna (L), and number of antennal segments (N Ant.). Length of the hind femur (H) was the most constant and precise character in each nymphal stage, subjected to little measuring bias and easy to measure when working with a high population density. Morphometrical and morphological data are expected to contribute to the ecological knowledge of this species.

Galectins as modulators of tumour progression

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Galectins as modulators of tumour progression Liu, Fu Tong; Rabinovich, Gabriel Adrián Galectins are a family of animal lectins with diverse biological activities. They function both extracellularly, by interacting with cell-surface and extracellular matrix glycoproteins and glycolipids, and intracellularly, by interacting with cytoplasmic and nuclear proteins to modulate signalling pathways. Current research indicates that galectins have important roles in cancer; they contribute to neoplastic transformation, tumour cell survival, angiogenesis and tumour metastasis. They can modulate the immune and inflammatory responses and might have a key role helping tumours to escape immune surveillance. How do the different members of the Galectin family contribute to these diverse aspects of tumour biology?

The role of urban air pollutants on the heavy metals accumulation performance of Usnea amblyoclada

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The role of urban air pollutants on the heavy metals accumulation performance of Usnea amblyoclada Carreras, Hebe Alejandra; Wannaz, Eduardo Daniel; Pérez, Carlos A.; Pignata, Maria Luisa Lichens incorporate heavy metals according to a selectivity sequence; therefore, their uptake rate can be affected when elements with a high affinity for cell wall exchange sites or that provoke harmful alterations to the metabolism of lichen thalli are present in the environment.The aim of this study was to examine the effect of urban pollutants on the accumulation of some heavy metals in Usnea amblyoclada.Lichen samples were transplanted for 1 month to both a polluted and a nonpolluted area in Córdoba, Argentina.They were then collected and soaked in tridistilled water or in solutions containing different concentrations of Cu, Ni, Pb, and Zn salts.The uptake of Cu2+, Ni2+, Zn2+, and Pb2+, and other parameters indicative of lichen damage were measured in all the lichen samples.The thalli retrieved from the polluted area showed significant increases in both the malonaldehyde content and the electrical conductivity of the water in which they had been immersed.These results indicate that the atmospheric pollutants could be responsible for the significant damage to the lichen’s cellular membranes, thus altering several mechanisms related to the uptake of heavy metals.Both the area of transplantation and the concentration of the metallic solutions had significant effects on the levels of Cu, Ni, and Pb measured in lichen thalli; however, no significant differences were observed in Zn concentrations.The highest uptakes corresponded to Pb and Cu, suggesting that they probably have a higher affinity with the lichen cell wall exchange sites.This study confirms the fact that, although lichens can be useful biological indicators, the physiological mechanisms involved in metal uptake should be carefully analyzed.Therefore, when estimating the heavy metal content of an environment, the competitive mechanism for cation uptake should be considered especially in areas where the presence of high levels of metals with a strong binding affinity is suspected.The presence of secondary products in the lichens could be responsible for the selective uptake of cations and for a possible tolerance to their presence.

Stationary and dynamical descriptions of strong correlated systems

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Stationary and dynamical descriptions of strong correlated systems Goldberg, Edith Catalina; Flores, F.; Monreal, R. This work is mainly devoted to the description of processes that involve the interaction between an atom and a surface, in which a strong Coulomb repulsion on the atomic site sUd limits the charge exchange to one electron sinfinite-U limitd. In this limit, the Anderson Hamiltonian for a many-fold sNd of states localized on the atomic site can be represented in terms of auxiliary bosons and physical operators in the mixed bosonelectron space can be defined. In this work the Hamiltonian is solved by defining appropriate Green’s functions for physical operators. Then we solved the equations of motion of these Green’s functions, up to a second order in the atom-surface coupling, either for the stationary case or for a real time-dependent problem. We show that our approach reproduces the known exact results in the nondegenerate sN=1d case, and for Ns1 gives excellent agreement with exact calculations and approximations valid for large N sthe 1/N expansiond. Finally, the accurate description of dynamical processes is shown by the comparison with the exact results available for a small four-level system. In this case we also compare with results obtained by using the noncrossing approximation and with the usual spinless model calculation.

Surfaces and local anisotropy effect in the magnetic order of Fe-Co-B nanoparticles

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Surfaces and local anisotropy effect in the magnetic order of Fe-Co-B nanoparticles Molina Concha, B.; Zysler, Roberto Daniel; Troiani, Horacio Esteban; Romero, H. 3 nm (FexCo1 x)yB1 y (0pxp1; y 0:6) nanoparticles were synthesized by chemical route. XDR and TEM measurement show the amorphous nature of the samples. Size distribution was characterized by light-scattering measurement. Magnetization vs. magnetic field measurements at room temperature show hysteresis loop for all compositions, typical of blocked single domains. In powder samples, room temperature coercive field and remanent are larger for Fe- or Co-rich composition, and saturation magnetization exhibit a minimum at x ¼ 0:15: This behaviour is related to the composition of the different local anisotropy associated to Fe and Co ions.

Estudio micropaleontológico de dos secuencias de la Cuenca Neuquina, centro oeste de Argentina

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Estudio micropaleontológico de dos secuencias de la Cuenca Neuquina, centro oeste de Argentina; A micropalaeontological study of two Jurassic sequences in the Neuquén Basin, central-west Argentina Ballent, Sara Cristina An example of application of calcareous microfossils to palaeoenvironmental reconstruction is presented. Foraminifers and Ostracoda from across the Aalenian-Bajocian boundary at the Picún Leufú section and Mid Callovian at the María Rosa Curicó section, both in Neuquén Basin, in central western Argentina, are analysed. The resulting data are presented as the following parameters: faunal density and specific diversity in both groups; test composition and vertical distribution of morphogroups in foraminifers; carapace morphology, adult valves to carapaces ratio and population age-structures in Ostracoda. Conclusions from the microfossils agree with those proposed by other authors based on sedimentological and palynological data. Additionally, two new Jurassic species (Middle Callovian) are described as new: the attached foraminifer Ammovertellina simeonae sp. nov. and the ostracod Cytherella mediodepressa sp. nov. Resumen. ESTUDIO MICROPALEONTOLÓGICO DE DOS SECUENCIAS DE LA CUENCA NEUQUINA, CENTRO OESTE DE ARGENTINA. Se analizan las asociaciones de foraminíferos y ostrácodos en las secciones Picún Leufú (límite Aaleniano-Bajociano) y María Rosa Curicó (Caloviano medio), ambas en la cuenca Neuquina. Los datos fueron organizados de acuerdo a los siguientes parámetros: densidad faunística y diversidad específica en ambos grupos; composición de la conchilla y distribución vertical de morfogrupos en foraminíferos; morfología del caparazón, relación en adultos entre valvas y caparazones y estructura poblacional en ostrácodos. Las conclusiones obtenidas a partir de los microfósiles coinciden con aquéllas provenientes de estudios sedimentológicos y palinológicos. Se describen como nuevos para el Caloviano medio, el foraminífero adherido Ammovertellina simeonae sp. nov. y el ostrácodo Cytherella mediodepressa sp. nov.; An example of application of calcareous microfossils to palaeoenvironmental reconstruction is presented. Foraminifers and Ostracoda from across the Aalenian-Bajocian boundary at the Picún Leufú section and Mid Callovian at the María Rosa Curicó section, both in Neuquén Basin, in central western Argentina, are analysed. The resulting data are presented as the following parameters: faunal density and specific diversity in both groups; test composition and vertical distribution of morphogroups in foraminifers; carapace morphology, adult valves to carapaces ratio and population age-structures in Ostracoda. Conclusions from the microfossils agree with those proposed by other authors based on sedimentological and palynological data. Additionally, two new Jurassic species (Middle Callovian) are described as new: the attached foraminifer Ammovertellina simeonae sp. nov. and the ostracod Cytherella mediodepressa sp. nov.

Static response in disk packings

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Static response in disk packings Moukarzel, Cristian Fernando; Pacheco Martínez, Hector; Ruiz-Suarez, J. C.; Vidales, Ana Maria We present experimental and numerical results for displacement response functions in packings of rigid frictional disks under gravity. The central disk on the bottom layer is shifted upwards by a small amount, and the motions of disks above it define the displacement response. Disk motions are measured with the help of a still digital camera. The responses so measured provide information on the force-force response, that is, the excess force at the bottom produced by a small overload in the bulk. We find that, in experiments, the vertical-force response shows a Gaussian-like shape, broadening roughly as the square root of distance, as predicted by diffusive theories for stress propagation in granulates. However, the diffusion coefficient obtained from a fit of the response width is ten times larger than predicted by such theories. Moreover we notice that our data is compatible with a crossover to linear broadening at large scales. In numerical simulations on similar systems (but without friction), on the other hand, a double-peaked response is found, indicating wave-like propagation of stresses. We discuss the main reasons for the different behaviors of experimental and model systems, and compare our findings with previous works.

Remaining coverage in associative desorption process

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Remaining coverage in associative desorption process Furlong, Octavio Javier; Manzi, Sergio Javier; Costanza, Gregorio José; Pereyra, Victor Daniel In this paper the kinetic of dissociative adsorption of dimers followed by associative desorption is analyzed. The coupled differential equations which describe the kinetics of the process were obtained by applying the so-called local evolution rules. Particular interest presents the irreversible desorption process. In fact, given that desorption proceeds from the reacting nearest-neighbor monomers, a remaining coverage results from those isolated particles when the mobility is neglected, therefore, the resulting configuration can be considered as a jamming state of the system. The exact solution for the remaining coverage is obtained in one-dimensional chain, where the effect of the lateral interactions are also included. The two-dimensional case is analyzed by using Monte Carlo simulation. The equilibrium solutions and the thermal desorption spectra are also studied.

¿Fundamentar o resignificar?: Observaciones sobre el sentido moderno de tolerancia

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¿Fundamentar o resignificar?: Observaciones sobre el sentido moderno de tolerancia Parente, Diego Carlos El presente trabajo indaga la siguiente pregunta: ¿es la noción moderna de tolerancia un concepto obsoleto o, al menos, debilitado? Y, en caso afirmativo, ¿cómo sustituirlo, cómo resignificarlo, cómo tomar su lugar, teniendo en cuenta que dicho concepto no regula algo irrelevante sino la misma trama de las relaciones humanas? Para sugerir una respuesta, se intenta previamente una aproximación a otra serie de nociones que se conectan de manera directa con la tolerancia (tales como ciudadanía y democracia). Posteriormente, se revisan el rescate rortyano de la noción humeana de "empatía" a fin de defender una alternativa a la tolerancia moderna que sea capaz de evitar su carácter paternalista.

Larval development of the subantarctic king crabs Lithodes santolla and Paralomis granulosa reared in the laboratory

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Larval development of the subantarctic king crabs Lithodes santolla and Paralomis granulosa reared in the laboratory Calcagno, Javier Ángel; Anger, K.; Lovrich, Gustavo Alejandro; Thatje, S.; Kaffenberger, A. The larval development and survival in the two subantarctic lithodid crabs Lithodes santolla (Jaquinot) and Paralomis granulosa (Molina) from the Argentine Beagle Channel were studied in laboratory cultures. In L. santolla, larval development lasted about 70 days, passing through three zoeal stages and the megalopa stage, with a duration of approximately 4, 7, 11 and 48 days, respectively. The larval development in P. granulosa is more abbreviated, comprising only two zoeal stages and the megalopa stage, with 6, 11 and 43 days' duration, respectively. In both species, we tested for effects of presence versus absence of food (Artemia nauplii) on larval development duration and survival rate. In P. granulosa, we also studied effects of different rearing conditions, such as individual versus mass cultures, as well as aerated versus unaerated cultures. No differences in larval development duration and survival were observed between animals subjected to those different rearing conditions. The lack of response to the presence or absence of potential food confirms, in both species, a complete lecithotrophic mode of larval development. Since lithodid crabs are of high economic importance in the artisanal fishery in the southernmost parts of South America, the knowledge of optimal rearing conditions for lithodid larvae is essential for future attempts at repopulating the collapsing natural stocks off Tierra del Fuego.

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