67 research outputs found

    Nanogeles de quitosano para la liberación controlada de polioxometalatos con aplicaciones biomédicas

    Get PDF
    [ES] Durante muchos años, la utilización de polímeros de origen natural se ha visto limitada al uso de materiales de tipo cotidiano como la lana, la seda o el caucho natural. No obstante, los biomateriales, tradicionalmente definidos como materiales de uso clínico, han presenciado un aumento en su grado de sofisticación y estos son el objeto de estudio de muchas líneas de investigación relacionadas con la medicina, biotecnología, genética y farmacia. Este desarrollo de nuevos biomateriales ha impulsado el uso de polímeros biodegradables para aplicaciones biomédicas. En este ámbito, los hidrogeles son de gran relevancia

    Nanogeles de quitosano para la liberación controlada de polioxometalatos con aplicaciones biomédicas

    Get PDF
    [ES] Durante muchos años, la utilización de polímeros de origen natural se ha visto limitada al uso de materiales de tipo cotidiano como la lana, la seda o el caucho natural. No obstante, los biomateriales, tradicionalmente definidos como materiales de uso clínico, han presenciado un aumento en su grado de sofisticación y estos son el objeto de estudio de muchas líneas de investigación relacionadas con la medicina, biotecnología, genética y farmacia. Este desarrollo de nuevos biomateriales ha impulsado el uso de polímeros biodegradables para aplicaciones biomédicas. En este ámbito, los hidrogeles son de gran relevancia

    Estudio de factibilidad para un minimercado de conveniencia en el Plan Parcial La Asomadera

    Get PDF
    Este trabajo pretende analizar la factibilidad de establecer un auto-mercado de conveniencia en el Plan Parcial La Asomadera (barrio El Poblado, Medellín) a través de un estudio del mercado constructor en la ciudad -- El proceso se realizará mediante una metodología que evalúe la factibilidad legal, ambiental, comercial, técnica y financiera del proyecto, con el fin de sentar las bases para un emprendimiento futur

    Long-Term Measurement of Piglet Activity Using Passive Infrared Detectors

    Get PDF
    Measuring animal activity is useful for monitoring animal welfare in real time. In this regard, passive infrared detectors have been used in recent years to quantify piglet activity because of their robustness and ease of use. This study was conducted on a commercial farm in Northwest Spain during six complete breeding cycles. The hourly average activity of weaned piglets with a body mass of 6–20 kg was recorded and further analyzed by using a multiplicative decomposition of the series followed by a wavelet analysis. Finally, the real series were compared to the theoretical models of activity. Results showed a high level of movement immediately after weaning and a sustained level of activity throughout the cycles. The daily behavior of the piglets followed a clear circadian pattern with several peaks of activity. No differences in behavior were observed between spring–summer cycles and autumn–winter cycles. Single-peak models achieved the best predictive results. In addition, the installed sensors were found to underestimate mild activityThis research was funded by Consellería de Educación, Universidade e Formación Profesional and Consellería de Economía, Emprego e Industria da Xunta de Galicia, grant number ED431B 2018/12-GPCS

    New Fertilizer Strategies Combining Manure and Urea for Improved Rice Growth in Mozambique

    Get PDF
    The cost of chemical fertilizers is increasing and becoming unaffordable for smallholders in Africa. The present study aimed to assess the impact of combined fertilization strategies using urea and animal manure (beef cattle manure and poultry litter manure) on rice yield and nutrient uptake. For this, a field experiment was carried out on a loam sandy soil in the Chókwè Irrigation Scheme. We set seven treatments in a Randomized Complete Block Design (RCBD), namely: T0: no fertilizer, T1: 100% urea, T2: 100% beef cattle manure, T3: 100% poultry litter, T4: 50% urea + 50% beef cattle manure, T5: 50% urea + 50% poultry litter and T6: 40% urea + 30% beef cattle manure + 30% poultry litter, replicated four times each. All treatments, except T0, received an amount of nitrogen (N) equivalent to 100 kgN ha1. Results revealed that the highest yield grain (425 g m2), plant height (115 cm), number of tillers (18) and thousand-grain weight (34g) were observed in treatments combining urea with manure (T4, T5 and T6) indicating that N supply in the mixture (urea + manure) is more efficient than in isolated applications of N (T1, T2 and T3). The data obtained in this study suggest that a combination of fertilizers (T6) lead to competitive yields and is thus recommended for best soil management practicesinfo:eu-repo/semantics/publishedVersio

    Evolution of NH3 Concentrations in Weaner Pig Buildings Based on Setpoint Temperature

    Get PDF
    Ammonia (NH3) concentration has seldom been used for environmental control of weaner buildings despite its impact on environment, animal welfare, and workers’ health. This paper aims to determine the effects of setpoint temperature (ST) on the daily evolution of NH3 concentration in the animal-occupied zone. An experimental test was conducted on a conventional farm, with ST between 23 °C and 26 °C. NH3 concentrations in the animal-occupied zone were dependent on ST insofar as ST controlled the operation of the ventilation system, which effectively removed NH3 from the building. The highest NH3 concentrations occurred at night and the lowest concentrations occurred during the daytime. Data were fitted to a sinusoidal model using the least squares setting (LSS) and fast Fourier transform (FFT), which provided R2 values between 0.71 and 0.93. FFT provided a better fit than LSS, with root mean square errors (RMSEs) between 0.09 ppm for an ST of 23 °C and 0.55 ppm for an ST of 25 °C. A decrease in ST caused a delay in the wave and a decrease in wave amplitude. The proposed equations can be used for modeling NH3 concentrations and implemented in conventional controllers for real-time environmental control of livestock buildings to improve animal welfare and productivityThis research was funded by Xunta de Galicia, grant number GPC-ED431B 2018/012S

    Validation of an AutoRegressive Integrated Moving Average model for the prediction of animal zone temperature in a weaned piglet building

    Get PDF
    An AutoRegressive Integrated Moving Average model was validated for the prediction of temperatures in the animal zone of conventional weaned piglet barn. The validation period covered seven cycles and recorded values at 10-min intervals for 292 days. Average weight was 5.75 ± 0.86 kg at the beginning of the production cycle and 18.41 ± 2.12 kg at the end of the cycle. Mean outdoor air temperatures ranged 6.14 to 17.85 °C with deviations in the range 2.49 °C to 5.24 °C, which involved marked differences in the operation of the ventilation system. The Mean Average Percentage Error was below 4%, with a mean error of ≤1 °C. The Root Mean Square Error was in the range 0.77 °C to 1.19 °C, whereas the coefficient of determination ranged between 0.52 and 0.81. Despite the changes in environmental conditions and in animal weight and management, the accuracy of the model remained stable with low dispersion of values. The model showed good accuracy and reliability covering all the seasons under changing meteorological conditions because it considered the operation of the heating and ventilation systems and changes in animal weight. The residuals obtained from the validation of the seven production cycles were Gaussian distributed, which confirmed the validity of the model. The generated model can be used for more effective environmental control systems that are capable of anticipating events and show a better response, which helps improve energy savings and animal welfareThe authors are grateful to the regional government Xunta de Galicia for funding this research through the “Programme of consolidation and structuring of competitive research units” (GPC2014/072)S

    Energy, Production and Environmental Characteristics of a Conventional Weaned Piglet Farm in North West Spain

    Get PDF
    Postweaning is one of the most sensitive and energy-demanding phases of swine production. The objective of this research was to assess the energy, production and environmental characteristics of a conventional farm with temperature-based environmental control. The selected energy, environmental and production variables were measured on farm, in a high livestock density area of NW Spain, for seven production cycles. The quantification of variables was aimed at obtaining the maximum performance with the lowest possible use of resources, focusing on animal welfare and production efficiency. The Brown–Forsythe, Welch and Games-Howell tests revealed significant differences in terms of temperature, relative humidity and CO2 concentrations among production cycles, and among the critical, postcritical and final periods. Improved humidity management resulted in a 17% reduction of climate control energy, which involved energy savings in the range of 33% to 47% per kg produced at the end of the postweaning cycle. Accordingly, adding humidity as a control variable could result in higher ventilation rates, thereby improving animal welfare, reducing heating energy use and increasing weight gain per unit climate control energy. In addition, the strong correlations found between heating energy and relative humidity (R2 = 0.73) and ventilation energy and CO2 (R2 = 0.99) suggest that these variables could be readily estimated without additional sensor costsThis research has received funding from European Regional Development Fund (ERDF) (2007–2013) under the project Control and automation strategies for energy and production efficiency in weaned farms, included in the research and innovation programme for Galicia, PEME I+D SumaS

    Evolution and neural network prediction of CO2 emissions in weaned piglet farms

    Get PDF
    This paper aims to study the evolution of CO2 concentrations and emissions on a conventional farm with weaned piglets between 6.9 and 17.0 kg live weight based on setpoint temperature, outdoor temperature, and ventilation flow. The experimental trial was conducted during one transition cycle. Generally, the ventilation flow increased with the reduction in setpoint temperature throughout the cycle, which caused a reduction in CO2 concentration and an increase in emissions. The mean CO2 concentration was 3.12 g m–3. Emissions of CO2 had a mean value of 2.21 mg s−1 per animal, which is equivalent to 0.195 mg s−1 kg−1. A potential function was used to describe the interaction between 10 min values of ventilation flow and CO2 concentrations, whereas a linear function was used to describe the interaction between 10 min values of ventilation flow and CO2 emissions, with r values of 0.82 and 0.85, respectively. Using such equations allowed for simple and direct quantification of emissions. Furthermore, two prediction models for CO2 emissions were developed using two neural networks (for 10 min and 60 min predictions), which reached r values of 0.63 and 0.56. These results are limited mainly by the size of the training period, as well as by the differences between the behavior of the series in the training stage and the testing stageThis research was funded by Consellería de Educación, Universidade e Formación Profesional and Consellería de Economía, Emprego e Industria from the Galician Government (Xunta de Galicia). Granted with reference ED431B 2018/12-GPCS

    Shared HLA Class II in Six Autoimmune Diseases in Latin America: A Meta-Analysis

    Get PDF
    The prevalence and genetic susceptibility of autoimmune diseases (ADs) may vary depending on latitudinal gradient and ethnicity. The aims of this study were to identify common human leukocyte antigen (HLA) class II alleles that contribute to susceptibility to six ADs in Latin Americans through a meta-analysis and to review additional clinical, immunological, and genetic characteristics of those ADs sharing HLA alleles. DRB1∗03:01 (OR: 4.04; 95%CI: 1.41–11.53) was found to be a risk factor for systemic lupus erythematosus (SLE), Sjogren’s syndrome (SS), and type 1 diabetes mellitus (T1D). DRB1 ¨ ∗04:05 (OR: 4.64; 95%CI: 2.14–10.05) influences autoimmune hepatitis (AIH), rheumatoid arthritis (RA), and T1D; DRB1∗04:01 (OR: 3.86; 95%CI: 2.32–6.42) is a susceptibility factor for RA and T1D. Opposite associations were found between multiple sclerosis (MS) and T1D. DQB1∗06:02 and DRB1∗15 alleles were risk factors for MS but protective factors for T1D. Likewise, DQB1∗06:03 allele was a risk factor for AIH but a protective one for T1D. Several common autoantibodies and clinical associations as well as additional shared genes have been reported in these ADs, which are reviewed herein. These results indicate that in Latin Americans ADs share major loci and immune characteristics
    corecore