Evaluación de ensilaje de triticale inoculado con bacterias homolácticas en minisilos de laboratorio

In two experiments, we studied the characteristics of ensiling and aerobic stability of triticale (x Triticosecale spp.) ensiled with or without a homolactic bacterial inoculant (HBI). The first experiment used 60 vacuum-sealed 0.946 L glass jar mini-silos (GJ) to determine the effect of ensiling on pH, dry matter recovery (DMR) and temperature. Three GJ per treatment were opened on d 0, 1, 2, 3, 5, 7, 14, 30, 105 and 123 of fermentation. Across all lengths of fermentation, inoculation decreased (P<0.05) average silage pH and temperature upon opening the mini-silos but did not influence (P>0.05) DMR versus the Non-HBI silage. Both silages had a similar (P>0.05) pH at the end of 123 d of fermentation. The second experiment compared the nutritional and fermentation characteristics and aerobic stability of triticale ensiled with or without HBI for 123 d in either 3L PVC mini-silos packed manually (PVC) or vacuum-sealed GJ. There was little difference (P>0.05) in silage nutrient content using PVC or GJ mini-silos, nor did inoculation affect these variables. Ensiling triticale decreased (P<0.05) its 30 h neutral detergent fiber (NDF) digestibility, the lowest value being that of Non-HBI/ PVC silage, which differed (P<0.05) from the HBI/PVC silage, but these did not differ (P>0.05) from the GJ silages. Differences among silages were not found (P>0.05) in NDF at 240 h (uNDF240), total tract NDF digestion (TTNDFD) and rate of NDF digestion (NDFkd). Triticale ensiled well in GJ, however the amount of material ensiled may have been too small to detect differences due to inoculation.En el primero de dos experimentos se determinó el efecto sobre el pH, la recuperación de materia seca (RMS) y la temperatura de ensilar triticale (x Triticosecale spp.) con o sin inoculante de bacteria homoláctica (IBH), utilizando 30 minisilos de vidrio de 0.946 L sellados al vacío (GJ) por tratamiento, que se abrieron a los días 0, 1, 2, 3, 5, 7, 14, 30, 105 y 123 de fermentación. Abarcando todos los largos de fermentación, la inoculación redujo (P<0.05) las medias de pH y temperatura al abrir los minisilos, pero no influyó (P>0.05) en la RMS relativo al ensilaje sin IBH. Ambos ensilajes tuvieron un pH similar (P>0.05) al finalizar el periodo de fermentación de 123 d. En el segundo experimento se compararon las características nutricionales, la fermentación y la estabilidad aeróbica del triticale ensilado con o sin IBH durante 123d en minisilos de 3L hechos de PVC y empacados manualmente o de GJ y sellados al vacío. Hubo mínimas diferencias (P>0.05) en el contenido nutricional del ensilaje fermentado en minisilos de PVC o GJ y la inoculación tampoco afectó estas variables. El ensilamiento de triticale disminuyó (P<0.05) la digestibilidad de la fibra detergente neutro (FDN) a las 30 h, correspondiendo el menor valor al ensilaje sin IBH/PVC, que difirió (P0.05) del ensilaje IBH/PVC, pero estos no tuvieron diferencia (P>0.05) con los ensilados en GJ. No hubo diferencia entre los ensilajes (P>0.05) en FDN no degradable a las 240 h (uFDN240), digestibilidad de FDN en el tracto entero (TTNDFD) y la velocidad de digestión de la FDN (NDFkd). El triticale fermentó bien en los minisilos de vidrio, sin embargo, la cantidad de material ensilado puede que no haya sido suficiente para poder detectar diferencias debido a la inoculación

Porcentaje de pérdida durante el proceso de fabricación del GSK-2809® tabletas

El proyecto se desarrolló en la planta de Laboratorios Claxo Smithkline (GSK), ubicado en la urbanización Industrial, corregimiento de Juan Díaz. GSK-Panamá se dedica a la producción y acondicionado de una amplia gama de especialidades farmacéuticas, exclusivamente de tipo sólido. El 98% de su línea está constituida por productos para exportación(Centroamérica, Suramérica, Hong Kong y, más recientemente, los Estados Unidos). En la actualidad, GSK tiene presencia en cerca de 130 países alrededor del mundo. Su misión: mejorar la calidad de vida de las personas, permitiéndoles hacer más cosas, sentirse mejor y vivir por más tiempo. La corporación nos manifestó su interés por abordar sistemáticamente un problema que ha venido afectando a las operaciones unitarias y los costos de fabricación de uno de sus productos líderes. A éste nos referiremos, en lo sucesivo, como el producto GSK2809 tabletas. De manera que, en esta coyuntura, el estudio fue orientado con el propósito de identificar las posibles causas de la desviación y sugerir medidas correctivas. En el primer capítulo de este informe, hacemos el planteamiento general del problema, su justificación, sus objetivos, sus antecedentes, su alcance y las limitaciones encontradas durante la ejecución. El segundo capítulo plantea la metodología utilizada. El tercero expone, analiza y discute los resultados. El cuarto y último presenta las conclusiones y la propuesta de mejoramiento. Sin embargo, el lector debe tener claro que, aunque las 488 horas de práctica nos permitieron alcanzar el origen del problema, no fueron suficientes para cristalizar una solución. algunos de los aspectos descritos en nuestra propuesta final podrían, incluso, favorecer las actividades generales de la planta. Es posible que ciertas debilidades y fortalezas que caracterizan el proceso de fabricación del GSK-2809 tabletas - ya sean de competencia técnica o administrativa- impacten también a otros productos

Background analysis and status of the ANAIS dark matter project

ANAIS (Annual modulation with NaI Scintillators) is a project aiming to set up at the new facilities of the Canfranc Underground Laboratory (LSC), a large scale NaI(Tl) experiment in order to explore the DAMA/LIBRA annual modulation positive result using the same target and technique. Two 12.5 kg each NaI(Tl) crystals provided by Alpha Spectra took data at the LSC in the ANAIS-25 set-up. The comparison of the background model for the ANAIS-25 prototypes with the experimental results is presented. ANAIS crystal radiopurity goals have been achieved for Th-232 and U-238 chains, but a Pb-210 contamination out-of-equilibrium was identified, whose origin has been studied. The high light collection efficiency obtained with these prototypes allows to anticipate an energy threshold of the order of 1 keVee. A new detector, with improved performances, was received in March 2015 and very preliminary results are shown.Comment: 6 pages, 7 figure

Preliminary results of ANAIS-25

The ANAIS (Annual Modulation with NaI(Tl) Scintillators) experiment aims at the confirmation of the DAMA/LIBRA signal using the same target and technique at the Canfranc Underground Laboratory. 250 kg of ultrapure NaI(Tl) crystals will be used as a target, divided into 20 modules, each coupled to two photomultipliers. Two NaI(Tl) crystals of 12.5 kg each, grown by Alpha Spectra from a powder having a potassium level under the limit of our analytical techniques, form the ANAIS-25 set-up. The background contributions are being carefully studied and preliminary results are presented: their natural potassium content in the bulk has been quantified, as well as the uranium and thorium radioactive chains presence in the bulk through the discrimination of the corresponding alpha events by PSA, and due to the fast commissioning, the contribution from cosmogenic activated isotopes is clearly identified and their decay observed along the first months of data taking. Following the procedures established with ANAIS-0 and previous prototypes, bulk NaI(Tl) scintillation events selection and light collection efficiency have been also studied in ANAIS-25.Comment: 4 pages, 6 Figure

Bulk NaI(Tl) scintillation low energy events selection with the ANAIS-0 module

Dark matter particles scattering off some target nuclei are expected to deposit very small energies in form of nuclear recoils (below 100 keV). Because of the low scintillation efficiency for nuclear recoils vs. electron recoils, in most of the scintillating targets considered in the search for dark matter, the region below 10 keVee concentrates most of the expected dark matter signal. For this reason, very low energy threshold (at or below 2 keVee) and very low background are required. This is the case of the ANAIS (Annual modulation with NaI Scintillators) experiment. A good knowledge of the detector response function for real scintillation events, a good characterization of other anomalous or noise event populations contributing in that energy range, and the development of convenient filtering procedures for the latter are mandatory to achieve the required low background at such a low energy. In this work we will present the specific protocols developed to select bulk scintillation events in NaI(Tl), and its application to data obtained with the ANAIS-0 prototype. Slight differences in time constants are expected in scintillation pulses produced by nuclear or electron recoils in NaI(Tl), so in order to analyze the effect of these filtering procedures in the case of a recoil population attributable to dark matter, data from a neutron calibration have been used.Comment: 13 pages, 22 figure

Chlamydia psittaci genotype B in a pigeon (Columba livia) inhabiting a public place in San José, Costa Rica

Human chlamydiosis is a zoonotic disease of avian origin caused by Chlamydia psittaci. The highest infection rates have been detected in parrots (Psittacidae) and pigeons (Columbiformes), the latter most frequently carry the genotypes B and E. These genotypes have been shown to also infect humans. Because pigeons (Columba livia) cohabit with humans in urban areas, C. psittaci present in the dust from dry feces of infected pigeons may be transmitted by inhalation and represent a significant public health problem. Between 2012 and 2013 a total of 120 fecal samples were collected from pigeons at four public places (Plaza de la Cultura, Parque Morazán, Parque Central de Guadalupe, Plaza de las Garantías Sociales) in San José, Costa Rica. A nested polymerase chain reaction (PCR) was used to amplify a region of the outer membrane protein A gene of C. psittaci. Only one sample was positive in PCR and the positive sample was further subjected to sequencing and genotyping. Sequencing identified this sample as C. psittaci genotype B. This study is the first report to show the presence of this organism in pigeons of Costa Rica, and shows that the infected pigeons may represent a significant risk for humans who visit public places that are inhabited by pigeons

Light yield determination in large sodium iodide detectors applied in the search for dark matter

Application of NaI(Tl) detectors in the search for galactic dark matter particles through their elastic scattering off the target nuclei is well motivated because of the long standing DAMA/LIBRA highly significant positive result on annual modulation, still requiring confirmation. For such a goal, it is mandatory to reach very low threshold in energy (at or below the keV level), very low radioactive background (at a few counts/keV/kg/day), and high detection mass (at or above the 100 kg scale). One of the most relevant technical issues is the optimization of the crystal intrinsic scintillation light yield and the efficiency of the light collecting system for large mass crystals. In the frame of the ANAIS (Annual modulation with NaI Scintillators) dark matter search project large NaI(Tl) crystals from different providers coupled to two photomultiplier tubes (PMTs) have been tested at the Canfranc Underground Laboratory. In this paper we present the estimates of the NaI(Tl) scintillation light collected using full-absorption peaks at very low energy from external and internal sources emitting gammas/electrons, and single-photoelectron events populations selected by using very low energy pulses tails. Outstanding scintillation light collection at the level of 15~photoelectrons/keV can be reported for the final design and provider chosen for ANAIS detectors. Taking into account the Quantum Efficiency of the PMT units used, the intrinsic scintillation light yield in these NaI(Tl) crystals is above 40~photoelectrons/keV for energy depositions in the range from 3 up to 25~keV. This very high light output of ANAIS crystals allows triggering below 1~keV, which is very important in order to increase the sensitivity in the direct detection of dark matter