268 research outputs found
Estimación de los principales indicadores productivos de ganadería bovina del departamento Curuzú Cuatiá, Corrientes, Argentina
In the present study, the physical indicators of bovine livestock in Curuzú Cuatiá department were estimated in order to provide useful information for the different economic, political, social and academic actors, as input for correct decision-making. The estimation was carried out using a methodology to measure the physical outcomes of agricultural companies according to the guidelines of the Argentine Association of Regional Consortiums for Agricultural Experimentation (AARCAE). The bovine load was calculated in cow equivalent ha-1, the calf-cow ratio and meat production in kg ha-1. The results obtained demonstrate that the productive indicators in Curuzú Cuatiá department are favorable when compared to the same indicators in the province of Corrientes. This information will enable strengthening decision-making and the proper evaluation of the impact of various factors affecting the activity with the aim of improving the productive indicators in the province of Corrientes.En el presente estudio se estimaron los indicadores físicos de ganadería bovina del departamento de Curuzú Cuatiá con la finalidad de contar con información que resulte de utilidad a los distintos actores económicos, políticos, sociales y académicos, como insumo para la correcta toma de decisiones. Para su estimación se utilizó la metodología para medir los resultados físicos de las empresas agropecuarias acorde a los lineamientos de la Asociación Argentina de Consorcios Regionales de Experimentación Agrícola (AACREA). Se calculó la carga bovina en equivalente vaca ha-1, la relación ternero- vaca y la producción de carne en kg ha-1. Los resultados obtenidos demuestran que los indicadores productivos en el departamento Curuzú Cuatiá son favorables al compararlos con los mismos indicadores de la provincia de Corrientes. Esta información permitirá fortalecer la toma de decisión y la adecuada evaluación del impacto de los diferentes factores que afectan la actividad con el objeto de mejor los indicadores productivos en la provincia de Corrientes
Rapid detection of trace bacteria in biofluids using porous monoliths in microchannels
We present advancements in microfluidic technology for rapid detection of as few as 10 rickettsial organisms in complex biological samples. An immuno-reactive filter, macroporous polyacrylamide monolith (PAM), fabricated within a microfluidic channel enhances solid-phase immuno-capture, staining and detection of targeted bacteria. Bacterial cells in samples flowing through the channel are forced to interact with the PAM filter surface due to size exclusion, overcoming common transport and kinetic limitations for rapid (min), high-efficiency (~100%) capture. In the process, targeted cells in sample volumes of 10 ?l to >100 ?l are concentrated within a sub-50 nl region at the PAM filter edge in the microchannel, thus concentrating them over 1000-fold. This significantly increases sensitivity, as the hydrophilic PAM also yields low non-specific immuno-fluorescence backgrounds with samples including serum, blood and non-targeted bacteria. The concentrated target cells are detected using fluorescently-labeled antibodies. With a single 2.0�0�3 mm PAM filter, as few as 10 rickettsial organisms per 100 祃 of lysed blood sample can be analyzed within 60 min, as compared to hours or even days needed for conventional detection methods. This method is highly relevant to rapid, multiplexed, low-cost point of care diagnostics at early stages of infection where diagnostics providing more immediate and actionable test results are needed to improve patient outcomes and mitigate potential natural and non-natural outbreaks or epidemics of rickettsial diseases
Extremely low secondary electron emission from metal/dielectric particulate coatings
Research on low secondary electron emission coatings is essential for the design and manufacture of space high-power RF devices without multipactor discharge. This paper discusses some of the factors that reduce secondary electron emission for metal-dielectric surfaces. We have studied the total electron yield (TEY) behavior of a particulate coating composed of a mixture of a metal (aluminum) nanoparticulates in solid state contact with a particulate dielectric material (polyimide thermosetting resin). Surface charging, roughness, and volume fraction are utilized as the main parameters to characterize the electron emission behavior, which can effectively be determined by continuous (total dose 42.5 nC/mm2) and pulsed (1,1 fC/mm2/pulse) electron irradiation methods. Apart from the important role played by surface composition in the TEY, the influence of the dielectric volume fraction has demonstrated to be critical to achieve a significant reduction of TEY. Analytical surface techniques such as field emission scanning microscopy and X-ray photoelectron spectroscopy were used, because they are very effective in providing insight into the effect of charging on the surface. Typical TEY parameters of the aluminum foil exposed to the air are: the first crossover energy, E1=20 eV, TEY maximum, σmax = 2.9, and Emax = XXX eV; these contrast with the dielectric values: E1= 30 eV, σmax = 2.5, and Emax = XXX eV. However, it was found that E1 of the particulate sample increased with increasing dielectric volume fraction. An extremely high first crossover energy, E1\u3e1000eV, was obtained after the gold metallization of the metal/dielectric coatings of 0.75 volume fraction. It is also remarkable that TEY was 0.2 for E\u3c1000\u3eeV, the low energy emitted electrons appear to be reabsorbed. Another remarkable fact is that TEY curves measured by using either the continuous or the pulsed methods overlap in the whole primary energy range, dissipate the much larger electron dose of the continuous method as compared to the very low dose of the pulsed method; this result is usually understood as an indication of minimal influence of charging on TEY
Open Clusters IC 4665 and Cr 359 and a Probable Birthplace of the Pulsar PSR B1929+10
Based on the epicyclic approximation, we have simulated the motion of the
young open star clusters IC 4665 and Collinder 359. The separation between the
cluster centers is shown to have been minimal 7 Myr ago, 36 pc. We have
established a close evolutionary connection between IC 4665 and the
Scorpius-Centaurus association -- the separation between the centers of these
structures was pc 15 Myr ago. In addition, the center of IC 4665
at this time was near two well-known regions of coronal gas: the Local Bubble
and the North Polar Spur. The star HIP 86768 is shown to be one of the
candidates for a binary (in the past) with the pulsar PSR B1929+10. At the
model radial velocity of the pulsar km s, a close
encounter of this pair occurs in the vicinity of IC 4665 at a time of -1.1 Myr.
At the same time, using currently available data for the pulsar B1929+10 at its
model radial velocity km s, we show that the hypothesis
of Hoogerwerf et al. (2001) about the breakup of the Oph--B1929+10
binary in the vicinity of Upper Scorpius (US) about 0.9 Myr ago is more
plausible.Comment: 19 pages, 8 figure
Establecimiento y mantenimiento de una colonia de Aedes taeniorhynchus, Wiedemann, 1821 (Díptera: Cullicidae) cepa Barranquilla, Colombia
A colony of Aedes taeniorhynchus, an efficient vector of venezuelan Equine Encephalitis, epidemo-epizootic type, was established. It was started by using adult forms, collected from regions close to the Atlantic coast town of Barranquilla (Colombia) Some biological aspects of this insect were studied, including life cycles and longevity. Actuarialtables were prepared and likewise, somephysical, environmental and nutritional parameters were established that guaranteed the maintainance and continuity of the species in laboratory conditions. The objective of this colony was to provide biological raw material for embryonic tissue explants that have been used to establish cell lines of continued growth.Se estableció una colonia del mosquito Aedes taeniorhynchus, eficientevector del virus de la encefalitis equina venezolana, tipo epidemo-epizoótico, a partir deformas adultas, recolectados en regiones cercanas a Barranquilla, Atlántico (Colombia). Se estudiaron algunos aspectos de la biología de este insecto (ciclo de vida y longevidad), elaboración de tablas de vida e igualmente se maximizaron algunos parámetrosfísicos, ambientales y nutricionales que garantizarán el mantenimiento y la continuidad de la especie en condiciones de laboratorio. Esta colonia fue establecida con el objeto de proporcionar la materia prima biológica para los explantes de tejidos embrionarios que se han venido utilizando para establecer líneas celulares de crecimiento continuo
Searching for chameleon-like scalar fields with the ammonia method
(Abridged) The ammonia method, which has been proposed to explore the
electron-to-proton mass ratio, mu = m_e/m_p, is applied to nearby dark clouds
in the Milky Way. This ratio, which is measured in different physical
environments of high (terrestrial) and low (interstellar) densities of baryonic
matter is supposed to vary in chameleon-like scalar field models, which predict
strong dependence of both masses and coupling constant on the local matter
density. High resolution spectral observations of molecular cores in lines of
NH3 (J,K) = (1,1), HC3N J = 2-1, and N2H+ J = 1-0 were performed at three radio
telescopes to measure the radial velocity offsets, DeltaV = V_rot - V_inv,
between the inversion transition of NH3 (1,1) and the rotational transitions of
other molecules with different sensitivities to the parameter dmm = (mu_obs -
mu_lab)/mu_lab. The measured values of DeltaV exhibit a statistically
significant velocity offset of 23 +/- 4_stat +/- 3_sys m/s. When interpreted in
terms of the electron-to-proton mass ratio variation, this infers that dmm =
(2.2 +/- 0.4_stat +/- 0.3_sys)x10^{-8}. If only a conservative upper bound is
considered, then the maximum offset between ammonia and the other molecules is
|DeltaV| <= 30 m/s. This gives the most accurate reference point at z = 0 for
dmm: |dmm| <= 3x10^{-8}.Comment: 23 pages, 11 figures, 6 tables. Accepted for publication in A&A.
Title and text corrected, references update
Some cultural consequences in Spain of the Spanish Invasion of Morocco 1859-60
This article argues is a contribution to the study of interrelationships between colonialism, art, and literature in the nineteenth century. The article argues that the Spanish invasion of Morocco in 1859 led to contradictions and tensions within liberal nationalism, not least because of concerns about the tensions between the need for military reassertion of Spain and the respect for the independence of nations. This led to some reconfiguration of Spanish intellectuals' already complex relationship with North Africa and Islam. A major, perhaps surprising consequence of this reconfiguration, was some equation of Moroccan identity with a monotonous surface that was resistant to the gaze. In consequence, the Catalan painter Fortuny's crucial experience of Morocco led him to value near blank surfaces, and thus to make a major contribution to the origins of modern art
Observations of chemical differentiation in clumpy molecular clouds
We have extensively mapped a sample of dense molecular clouds (L1512, TMC-1C,
L1262, Per 7, L1389, L1251E) in lines of HC3N, CH3OH, SO and C^{18}O. We
demonstrate that a high degree of chemical differentiation is present in all of
the observed clouds. We analyse the molecular maps for each cloud,
demonstrating a systematic chemical differentiation across the sample, which we
relate to the evolutionary state of the cloud. We relate our observations to
the cloud physical, kinematical and evolutionary properties, and also compare
them to the predictions of simple chemical models. The implications of this
work for understanding the origin of the clumpy structures and chemical
differentiation observed in dense clouds are discussed.Comment: 20 pages, 7 figures. Higher quality figures appear in the published
journal articl
GASKAP -- The Galactic ASKAP Survey
A survey of the Milky Way disk and the Magellanic System at the wavelengths
of the 21-cm atomic hydrogen (HI) line and three 18-cm lines of the OH molecule
will be carried out with the Australian Square Kilometre Array Pathfinder
telescope. The survey will study the distribution of HI emission and absorption
with unprecedented angular and velocity resolution, as well as molecular line
thermal emission, absorption, and maser lines. The area to be covered includes
the Galactic plane (|b|< 10deg) at all declinations south of delta = +40deg,
spanning longitudes 167deg through 360deg to 79deg at b=0deg, plus the entire
area of the Magellanic Stream and Clouds, a total of 13,020 square degrees. The
brightness temperature sensitivity will be very good, typically sigma_T ~ 1 K
at resolution 30arcsec and 1 km/s. The survey has a wide spectrum of scientific
goals, from studies of galaxy evolution to star formation, with particular
contributions to understanding stellar wind kinematics, the thermal phases of
the interstellar medium, the interaction between gas in the disk and halo, and
the dynamical and thermal states of gas at various positions along the
Magellanic Stream.Comment: 45 pages, 8 figures, Pub. Astron. Soc. Australia (in press
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