4,538 research outputs found
Microstructural changes of 'rocha' pear following storage under controlled atmosphere
This research effort was aimed at evaluating the influence of storage (for 4 mo at 2°C), under various controlled atmospheres (viz. 1.9 kPa O2 + 4.9 kPa CO2, 1.9 kPa O2 + 0.5 kPa CO2 and 1.9 kPa O2 + 0 kPa CO2), on the microstructure of ′Rocha′ pear. Toward this goal, the morphology of cellular disassembly, as well as the quantity of granules and intercellular space using scanning electron microscopy (SEM), were tentatively correlated with sensory and instrumental firmness, by 1, 6 and 8 d of exposure to air, at room temperature, after storage. A specific methodology, based on panel evaluation of SEM images, was developed and statistically validated. The degree of cellular disassembly increased throughout exposure time to air at room temperature. Pears stored under 1.9 kPa O2 + 0.5 kPa CO2 yielded a degree of cellular disassembly similar to that of the control
Entangled-State Lithography: Tailoring any Pattern with a Single State
We demonstrate a systematic approach to Heisenberg-limited lithographic image
formation using four-mode reciprocal binominal states. By controlling the
exposure pattern with a simple bank of birefringent plates, any pixel pattern
on a grid, occupying a square with the side half a
wavelength long, can be generated from a -photon state.Comment: 4 pages, 4 figure
Efecto de un programa de educación física regular y cuentos motores en la aptitud física y desarrollo motor de escolares costarricenses
Changes in Cardiovascular Resistance [RCV], Trunk Expander Force [FET] and Fundamental Movement Skills [DFM] in children were determined after receiving a Regular Physical Education Program [PEFR]; or, a Motor Story Program [PCM]; and, verifying differences between Moderate and Vigorous Physical Activity [AFMV]. 55 students completed the study, divided into three groups PEFR, PCM and Control Group (GC). The groups received 20 classes, not the GC. AFMV time was accounted for using POLAR®. FITNESSGRAM® and TGMD-2® were used to measure variables. The RCV and FET in operated groups improved. The DFM in both intervention groups improved. Although the subjects maintained a Low Coefficient of Motor Development (CDMG); the programs contributed to its improvement, but not the GC that kept a very poor CDMG. The PCM and the PEFR were effective in generating changes in physical fitness and skills analyzed.Se determinaron cambios en la Resistencia Cardiovascular [RCV], Fuerza del Extensor del Tronco [FET] y Destrezas Fundamentales de Movimiento [DFM] en niños, luego de recibir un Programa de Educación Física Regular [PEFR]; o, un Programa de Cuentos Motores [PCM]; y, comprobando diferencias entre Actividad Física Moderada y Vigorosa [AFMV]. 55 estudiantes completaron el estudio, distribuidos en tres grupos PEFR, PCM y Grupo Control (GC). Los grupos recibieron 20 clases no el GC. Se contabilizó el tiempo de AFMV mediante POLAR®. Se utilizó FITNESSGRAM® y TGMD-2® para medir variables. La RCV y FET en grupos intervenidos mejoró. Las DFM en ambos grupos intervenidos mejoró. A pesar de que los sujetos mantuvieron un Coeficiente de Desarrollo Motor Grueso (CDMG) bajo; los programas coadyuvaron a su mejoría, no así el GC que conservó un CDMG muy pobre. El PCM y el PEFR fueron eficaces para generar cambios en aptitud física y destrezas analizadas
First report of Solanum sisymbriifolium and S. americanum as Natural weed hosts of Tomato chlorosis virus (Genus Crinivirus) in South America.
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Development of an active risk-based surveillance strategy for avian influenza in Cuba
AbstractThe authors designed a risk-based approach to the selection of poultry flocks to be sampled in order to further improve the sensitivity of avian influenza (AI) active surveillance programme in Cuba. The study focused on the western region of Cuba, which harbours nearly 70% of national poultry holdings and comprise several wetlands where migratory waterfowl settle (migratory waterfowl settlements – MWS). The model took into account the potential risk of commercial poultry farms in western Cuba contracting from migratory waterfowl of the orders Anseriformes and Charadriiformes through dispersion for pasturing of migratory birds around the MWS. We computed spatial risk index by geographical analysis with Python scripts in ESRI® ArcGIS 10 on data projected in the reference system NAD 1927–UTM17. Farms located closer to MWS had the highest values for the risk indicator pj and in total 31 farms were chosen for targeted surveillance during the risk period. The authors proposed to start active surveillance in the study area 3 weeks after the onset of Anseriformes migration, with additional sampling repeated twice in the same selected poultry farms at 15 days interval (Comin et al., 2012; EFSA, 2008) to cover the whole migration season. In this way, the antibody detectability would be favoured in case of either a posterior AI introduction or enhancement of a previous seroprevalence under the sensitivity level. The model identified the areas with higher risk for AIV introduction from MW, aiming at selecting poultry premises for the application of risk-based surveillance. Given the infrequency of HPAI introduction into domestic poultry populations and the relative paucity of occurrences of LPAI epidemics, the evaluation of the effectiveness of this approach would require its application for several migration seasons to allow the collection of sufficient reliable data
Twitter como herramienta de apoyo a la docencia
Memoria ID-0062. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2017-2018
Development of a CMOS-compatible PCR chip : comparison of design and system strategies
Altres ajuts: this work was partly funded by the Consejo Superior de Investigaciones Científicas (CSIC), by grant TIC97-0569 from the Comision Interministerial de Ciencia y Tecnología (CICYT).In the last decade research in chips for DNA amplification through the polymerase chain reaction (PCR) has been relatively abundant, but has taken very diverse approaches, leaving little common ground for a straightforward comparison of results. Here we report the development of a line of PCR chips that is fully compatible with complementary-metal-oxide-semiconductor (CMOS) technology and its revealing use as a general platform to test and compare a wide range of experimental parameters involved in PCR-chip design and operation. Peltier-heated and polysilicon thin-film driven PCR chips have been produced and directly compared in terms of efficiency, speed and power consumption, showing that thin-film systems run faster and more efficiently than Peltier-based ones, but yield inferior PCR products. Serpentine-like chamber designs have also been compared with standard rectangular designs and with the here reported rhomboidal chamber shape, showing that serpentine-like chambers do not have detrimental effects in PCR efficiency when using non-flow-through schemes, and that chamber design has a strong impact on sample insertion/extraction yields. With an accurate temperature control (±0.2 °C) we have optimized reaction kinetics to yield sound PCR amplifications of 25 µl mixtures in 20 min and with 24.4 s cycle times, confirming that a titrated amount of bovine albumin serum (BSA, 2.5 µg µl−1) is essential to counteract polymerase adsorption at chip walls. The reported use of a CMOS-compatible technological process paves the way for an easy adaption to foundry requirements and for a scalable integration of electro-optic detection and control circuitr
Sub-wavelength lithography over extended areas
We demonstrate a systematic approach to sub-wavelength resolution
lithographic image formation on films covering areas larger than a wavelength
squared. For example, it is possible to make a lithographic pattern with a
feature size resolution of by using a particular -photon, multi-mode entangled state, where , and banks of birefringent
plates. By preparing a statistically mixed such a state one can form any pixel
pattern on a pixel grid occupying a square
with a side of wavelengths. Hence, there is a trade-off between
the exposed area, the minimum lithographic feature size resolution, and the
number of photons used for the exposure. We also show that the proposed method
will work even under non-ideal conditions, albeit with somewhat poorer
performance.Comment: 8 pages, 8 figures, 1 table. Written in RevTe
Actions for the Restoration of the Biodiversity of Forest Ecosystems in Cuba
The Earth is threatened daily by the degradation of its ecosystems due to fragmentation. One of the main consequences is biodiversity loss. Despite the economic progress and conservation actions carried out in many countries, the planet is losing genuine tropical forest due to diverse reasons. This chapter presents the results obtained during the restoration of three tropical forests in Cuba: 1) the mesophyll semi-deciduous forest in the western sector of the Biosphere Reserve 'Sierra del Rosario' (BRSR); 2) the riverside forest of the Cuyaguateje River in western Cuba; and 3) the exploited native rainforests of the sector Quibiján-Naranjal of the River Toa in eastern Cuba
Cross sections for proton induced high energy γ-ray emission (PIGE) in reaction 19F(p,αγ)16O at incident proton energies between 1.5 and 4 MeV
Plan I2C 2013 by Xunta de Galicia (ES) PEstOE/Fis/UI0275/2014 Sem PDF conforme despacho.We have studied the high energy gamma-rays produced in the reaction 19F(p,αγ)16O for incident proton energies from 1.5 to 4.0 MeV over NaF/Ag and CaF2/Ag thin targets in two different sets of data. Gamma-rays were detected with a High Purity Ge detector with an angle of 130° with respect to the beam axis. The cross-sections for the high energy gamma-rays of 6.129, 6.915 and 7.115 MeV have been measured for the whole group between 5 and 7.2 MeV with accuracy better than 10%. A new energy range was covered and more points are included in the cross-sections data base expanding the existing set of data. Results are in agreement with previous measurements in similar conditions.preprintpublishe
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