Nutrición y alimentación de rumiantes jóvenes

Los animales jóvenes representan uno de los mayores problemas de las explotaciones comerciales, puesto que es en este momento cuando se deben sentar las bases para un correcto crecimiento y es, a su vez, cuando más delicados son todos los animales en general

Valuation of defer and relocation options in photovoltaic generation investments by a stochastic simulation-based method

Risk management is crucial when committing investments in electricity markets. Investment projects for the generation of electricity are capital-intensive, in large part irreversible and future performance is subject to high uncertainty. Fortunately, most power generation projects have strategic flexibility for handling uncertainty and for mitigating risks under unfavorable scenarios. Modern corporate finance recognizes Real Option analysis (ROA) as the correct way to value investment projects with these characteristics. Due to both, environmental concerns and escalation of fuel prices, electricity generation from renewable sources has grown dramatically worldwide over the last decade. Renewable investment projects share many of the features mentioned. As such, option valuation methods should be applied to estimate the monetary value of flexibility in renewable energy investments. This work presents an appropriate methodology for assessing the economic value of a photovoltaic power plant under uncertainties. ROA is applied to determine the value of delaying the investment decision while waiting for better market information that would reduce acquisition costs due to progress in solar technology. The flexibility of relocating the solar facility in the future upon the appearance of a more attractive site in terms of cost, network accessibility or regulatory policies is also valued. The problem of option valuation is solved through stochastic simulation combined with recursive approximate dynamic programming techniques. The methodology developed might be used by investors for more efficient decision-making and by regulatory agencies for designing adequate support policies that encourage investment in renewable energy generation.Fil: Pringles, Rolando Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Energía Eléctrica. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; ArgentinaFil: Olsina, Fernando Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Energía Eléctrica. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; ArgentinaFil: Penizzotto Bacha, Franco Victor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Energía Eléctrica. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentin

Effect of stripe clearing on 4 grasses species and 2 broadleaves of caldenal

En la Región del Espinal, Distrito del Caldén, en la provincia de San Luis existe un fuerte proceso de agriculturización con la consecuente pérdida de remanentes de bosque nativo, peligro de conservación de especies nativas e invasión de especies exóticas. El objetivo del presente trabajo fue evaluar el efecto del desmonte en franjas sobre 6 especies del caldenal (4 gramíneas y 2 latifoliadas). El estudio se realizó en un campo a 15 km. al norte de la ciudad de Villa Mercedes (San Luis), sometido a un desmonte en franjas para uso agrícola en el año 2003. En 5 sitios ubicados en franjas remanentes de bosque nativo y 5 en bosque nativo sin desmonte, se trazaron transectas de 39 m de longitud, dirección NS y a lo largo de la misma se registraron las especies presentes en 14 unidades de muestreo de 1 m2. Los datos se analizaron utilizando IBM SPSS Statistics 19, mediante Métodos No Paramétricos, U de Mann-Whitney. El análisis estadístico mostró diferencias significativas (p<0.05) en Digitaria californica, Pappophorum pappiferum, Salsola kali y Cestrum parqui. El estudio demostró que el cultivo entre franjas de bosque nativo produjo un cambio en la frecuencia de poáceas nativas y de latifoliadas.In the region of “Espinal”, Calden Distrct in the province of San Luis there is a strong agriculturization process with the consequent loss of native forest remnants, conserving endangered native species and invasion of exotic species. The aim of this study was to evaluate the effect of the stripe clearing on 6 species of caldenal (4 grasses and 2 broa- dleaves). The study was conducted in a field 15 km to the north of the city of Villa Mercedes (San Luis), subjected to a strip-clearing for agricultural use, in the year 2003. On 5 sites into native forest remnants stripes and 5 into without clearing native forest, 39 m long tran- sects were laid, N-S direction, and along the same were recorded the presente species in 14 sampling units of 1 m2. Data were analyzed by IBM SPSS Statistics 19, through non- parametric methods, Mann-Whitney U. Statistical analysis showed significant differences (p <0.05) in Digitaria californica, Pappophorum pappiferum, Salsola kali and Cestrum par- qui. The study showed that the cultivation of native forest between stripes was a change in the frequency of native grasses and broadleaves.Fil: Ruiz, O. M.. Universidad Nacional de San Luis; Argentina;Fil: Luna, H. R.. Universidad Nacional de San Luis; Argentina;Fil: Bacha, Emmanuel Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - San Luis; Argentina; Universidad Nacional de San Luis; Argentina;Fil: Pedranzani, H.. Universidad Nacional de San Luis; Argentina;Fil: Gabutti, E.G.. Universidad Nacional de San Luis; Argentina

The Use of Silica Microparticles to Improve the Efficiency of Optical Hyperthermia (OH)

Although optical hyperthermia could be a promising anticancer therapy, the need for high concentrations of light-absorbing metal nanoparticles and high-intensity lasers, or large exposure times, could discourage its use due to the toxicity that they could imply. In this article, we explore a possible role of silica microparticles that have high biocompatibility and that scatter light, when used in combination with conventional nanoparticles, to reduce those high concentrations of particles and/or those intense laser beams, in order to improve the biocompatibility of the overall procedure. Our underlying hypothesis is that the scattering of light caused by the microparticles would increase the optical density of the irradiated volume due to the production of multiple reflections of the incident light: the nanoparticles present in the same volume would absorb more energy from the laser than without the presence of silica particles, resulting either in higher heat production or in the need for less laser power or absorbing particles for the same required temperature rise. Testing this new optical hyperthermia procedure, based on the use of a mixture of silica and metallic particles, we have measured cell mortality in vitro experiments with murine glioma (CT-2A) and mouse osteoblastic (MC3T3-E1) cell lines. We have used gold nanorods (GNRs) that absorb light with a wavelength of 808 nm, which are conventional in optical hyperthermia, and silica microparticles spheres (hereinafter referred to as SMSs) with a diameter size to scatter the light of this wavelength. The obtained results confirm our initial hypothesis, because a high mortality rate is achieved with reduced concentrations of GNR. We found a difference in mortality between CT2A cancer cells and cells considered non-cancer MC3T3, maintaining the same conditions, which gives indications that this technique possibly improves the efficiency in the cell survival. This might be related with differences in the proliferation rate. Since the experiments were carried out in the 2D dimensions of the Petri dishes, due to sedimentation of the silica particles at the bottom, whilst light scattering is a 3D phenomenon, a large amount of the energy provided by the laser escapes outside the medium. Therefore, better results might be expected when applying this methodology in tissues, which are 3D structures, where the multiple reflections of light we believe will produce higher optical density in comparison to the conventional case of no using scattering particles. Accordingly, further studies deserve to be carried out in this line of work in order to improve the optical hyperthermia technique.This study was partially supported by CIBER-BBN (Spain) and the NEUROCENTRO-CM (B2017/BMD-3760) Consortium. Characterization of the MNPs was performed by the ICTS ‘NANBIOSIS’, Unit 15, Functional Characterization of Magnetic Nanoparticles of the CIBER in Bioengineering, Biomaterials & Nanomedicine (CIBER-BBN) at the Center for Biomedical Technology (CTB) of the ‘Universidad Politécnica de Madrid’ (UPM). This work was carried out as a part of Project PGC2018-097531-B-I00, funded by the Ministry of Science of Spain

Global, regional, and national under-5 mortality, adult mortality, age-specific mortality, and life expectancy, 1970–2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND: Detailed assessments of mortality patterns, particularly age-specific mortality, represent a crucial input that enables health systems to target interventions to specific populations. Understanding how all-cause mortality has changed with respect to development status can identify exemplars for best practice. To accomplish this, the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) estimated age-specific and sex-specific all-cause mortality between 1970 and 2016 for 195 countries and territories and at the subnational level for the five countries with a population greater than 200 million in 2016. METHODS: We have evaluated how well civil registration systems captured deaths using a set of demographic methods called death distribution methods for adults and from consideration of survey and census data for children younger than 5 years. We generated an overall assessment of completeness of registration of deaths by dividing registered deaths in each location-year by our estimate of all-age deaths generated from our overall estimation process. For 163 locations, including subnational units in countries with a population greater than 200 million with complete vital registration (VR) systems, our estimates were largely driven by the observed data, with corrections for small fluctuations in numbers and estimation for recent years where there were lags in data reporting (lags were variable by location, generally between 1 year and 6 years). For other locations, we took advantage of different data sources available to measure under-5 mortality rates (U5MR) using complete birth histories, summary birth histories, and incomplete VR with adjustments; we measured adult mortality rate (the probability of death in individuals aged 15-60 years) using adjusted incomplete VR, sibling histories, and household death recall. We used the U5MR and adult mortality rate, together with crude death rate due to HIV in the GBD model life table system, to estimate age-specific and sex-specific death rates for each location-year. Using various international databases, we identified fatal discontinuities, which we defined as increases in the death rate of more than one death per million, resulting from conflict and terrorism, natural disasters, major transport or technological accidents, and a subset of epidemic infectious diseases; these were added to estimates in the relevant years. In 47 countries with an identified peak adult prevalence for HIV/AIDS of more than 0·5% and where VR systems were less than 65% complete, we informed our estimates of age-sex-specific mortality using the Estimation and Projection Package (EPP)-Spectrum model fitted to national HIV/AIDS prevalence surveys and antenatal clinic serosurveillance systems. We estimated stillbirths, early neonatal, late neonatal, and childhood mortality using both survey and VR data in spatiotemporal Gaussian process regression models. We estimated abridged life tables for all location-years using age-specific death rates. We grouped locations into development quintiles based on the Socio-demographic Index (SDI) and analysed mortality trends by quintile. Using spline regression, we estimated the expected mortality rate for each age-sex group as a function of SDI. We identified countries with higher life expectancy than expected by comparing observed life expectancy to anticipated life expectancy on the basis of development status alone. FINDINGS: Completeness in the registration of deaths increased from 28% in 1970 to a peak of 45% in 2013; completeness was lower after 2013 because of lags in reporting. Total deaths in children younger than 5 years decreased from 1970 to 2016, and slower decreases occurred at ages 5-24 years. By contrast, numbers of adult deaths increased in each 5-year age bracket above the age of 25 years. The distribution of annualised rates of change in age-specific mortality rate differed over the period 2000 to 2016 compared with earlier decades: increasing annualised rates of change were less frequent, although rising annualised rates of change still occurred in some locations, particularly for adolescent and younger adult age groups. Rates of stillbirths and under-5 mortality both decreased globally from 1970. Evidence for global convergence of death rates was mixed; although the absolute difference between age-standardised death rates narrowed between countries at the lowest and highest levels of SDI, the ratio of these death rates-a measure of relative inequality-increased slightly. There was a strong shift between 1970 and 2016 toward higher life expectancy, most noticeably at higher levels of SDI. Among countries with populations greater than 1 million in 2016, life expectancy at birth was highest for women in Japan, at 86·9 years (95% UI 86·7-87·2), and for men in Singapore, at 81·3 years (78·8-83·7) in 2016. Male life expectancy was generally lower than female life expectancy between 1970 and 2016, an