Effect of Sm-, Gd- codoping on structural modifications in aluminoborosilicate glasses under beta-irradiation

Two series of Sm-, Gd-codoped aluminoborosilicate glasses with different total rare earth content have been studied in order to examine the codoping effect on the structural modifications of beta-irradiated glasses. The data obtained by Electron Paramagnetic Resonance spectroscopy indicated that relative amount of Gd3+ ions located in network former position reveals non-linear dependence on Sm/Gd ratio. Besides, codoping leads to the evolution of the EPR signal attributed to defects created by irradiation: superhyperfine structure of boron oxygen hole centres EPR line becomes less noticeable and resolved with increase of Gd amount. This fact manifests that Gd3+ ions are mainly diluted in vicinity of the boron network. By Raman spectroscopy, we showed that the structural changes induced by the irradiation also reveal non-linear behaviour with Sm/Gd ratio. In fact, the shift of the Si-O-Si bending vibration modes has a clear minimum for the samples containing equal amount of Sm and Gd (50:50) in both series of the investigated glasses. In contrast, for single doped glass there is no influence of dopant's content on Si-O-Si shift (in case of Gd) or its diminution (in case of Sm) occurs which is explained by the reduction process influence. At the same time, no noticeable effect of codoping on Sm3+ intensity as well as on Sm2+ emission or on Sm reduction process was observed

Quality of the forage apparently consumed by beef calves in natural grassland under fertilization and oversown with cool season forage species

The objective of this study was to evaluate the chemical composition of the forage apparently consumed by steers in a natural grassland on region of Campanha, in Rio Grande do Sul, Brazil, subjected or not to different inputs: NP - natural pasture without inputs; FNP - fertilized natural pasture and INP - improved natural grassland with fertilization and over-seeded with cultivated winter species. Three Angus steers testers and a variable number of regulator animals per experimental unit were utilized in order to maintain 13 kg of DM/100 kg of live weight (LW) as forage allowance. One time at each season, hand plucking samples were performed along the daily grazing time simulating forage harvested by the animals. The collected samples after drying and grind were submitted to chemical analysis to determine the forage quality. Except in winter and spring, the values of neutral detergent fiber were higher than the critical value of 550 g/kg of DM, which could limit forage intake, demonstrating that the values of forage on offer provided (15.6; 13.7; 13.5; 15.8 kg of DM/100 kg of LW/day in summer, autumn, winter and spring, respectively) were not restrictive to intake. The oversowing of winter cultivated species or fertilization positively alter the degradable fiber content. The seasons had marked influence on the chemical composition of forage apparently consumed; positively increasing some fractions of forage chemical composition in the seasons in which native or cultivated winter species increased their participation. The forage chemical composition is the determining factor in animal performance in natural pasture

The use of taxonomic relationships among species in applied ecological research: Baseline, steps forward and future challenges

Taxonomy is more than a mere exercise of nomenclature and classification of biological diversity: it profiles the identity of species by investigating their biological and ecological traits. Taxonomy is intimately related to ecology which, in turn, cannot be a mere exercise in describing ecological patterns, but instead requires deep knowledge of species’ biological structures, roles, interactions and functions. Thus, the study of taxonomic and phylogenetic relatedness of species is of paramount importance in ecological research, enabling insights into potential evolutionary patterns and processes, allowing a more comprehensive view of biodiversity, and providing opportunities to improve the assessment and monitoring of ecological changes in time and space. The work of K. Robert (‘Bob’) Clarke forged new pathways in this direction, providing new ideas and statistical tools to include and exploit taxonomic relationships in applied marine ecological studies and beyond, also inspiring the next generation of ecologists. In this short review, we synthesise the application and development of these tools and concepts in marine biodiversity research over the last three decades and suggest future pathways in this evolving field

Quantifying the ecological diversity and health of online news

Contains fulltext : 195399pr.pdf (preprint version ) (Open Access) Contains fulltext : 195399.pdf (Publisher’s version ) (Open Access

Ochratoxin a removal from red wine by several oenological fining agents: Bentonite, egg albumin, allergen-free adsorbents, chitin and chitosan

The ability of several oenological fining agents to remove ochratoxin A (OTA) from red wine was studied. The adsorbents tested were activated sodium bentonite, egg albumin, allergen-free adsorbents (complex PVPP, plant protein and amorphous silica (complex) and high molecular weight gelatine), and the non-toxic biodegradable polymers (chitin and chitosan). Several dosages within the oenological use range were tested and the wine pH, colour parameters and polyphenol concentration impact associated with each fining agent were studied. Generally, OTA removal achieved in all treatments was higher when the adsorbent dosage increased, but the impact on wine quality also was higher. Chitin at 50ghl_1 removed 18% the OTA without affecting significantly the wine-quality parameters. At the highest dosage tested the gelatine and complex treatments achieved greater OTA removal (up to 39-40%) compared with bentonite, egg albumin and chitin. Moreover, the gelatine and the complex had a lower impact on colour parameters and polyphenol concentration compared with chitosan, whilst OTA was reduced to around 40%. Chitosan achieved the greatest OTA removal (67%), but it strongly affected the wine-quality parameters. Otherwise, bentonite showed a relative efficiency to remove OTA, but the CI value decreased considerably. The egg albumin treatment only removed OTA up to 16% and moreover affected strongly the CI value and CIELab parameters. The results of this survey showed that the non-toxic chitin adsorbent and the allergen-free adsorbents tested could be considered as alternative fining agents to reduce OTA in red wine.Peer reviewe

Desacidification of milk by continuou electric treatment

CONTENIDO Editorial Ramos Parra, César Valores hematológicos en caprinos del estado Zulia, Venezuela Hematological values in goats from Zulia state, Venezuela Arraga de Alvarado, Cruz María Desacidificación de la leche por tratamiento eléctrico continuo Desacidification of milk by continuou electric treatment Farias R., José F.; Boscán F., Luis A. y Elejalde V., Luis E. Progesterona postparto y comportamiento productivo - reproductivo de vacas mestizas primíparas postparttum progesterone and productive - reproductive performance in primiparous crossbred cows Ramírez I., Lílido N.; Soto B. Eleazar; González Stagnaro, Carlos; Soto C., Gustavo. y Rincón U., Edmundo. Efecto de la prostaglandina F2 alfa y cipionato de estradiol sobre la fertilidad en vacas mestizas lecheras entre 40 - 50 días postparto Effect of prostaglandin F2 alpha and estradiol cypionate on the fertility in cross breed milking cattle between 40 - 50 days postpartum González F., Rumualdo y Bustillos C., Sergio Efecto de diferentes niveles iniciales de nitrito y tipo de fibra en algunas características de productos curados Effect of different initial levels of nitrite and fiber types on some characteristics of cured products Márquez S., Enrique y Salazar, Arturo. Aspectos radiológicos de lesiones cavitantes en el pulmón de los animales Radiological aspects of cavitary pulmonary lesions in animals Alvarado Morillo, Manuel Perspectivas de investigación en zoonosis Research prospects in zoonosis Málaga, Hernán. Mensajes Institucionales18-26Nivel analíticobimestra

Estructuración de un portafolio óptimo de inversión en divisas representativas del mercado Forex

El mercado de divisas actual ofrece diferentes alternativas de inversión, donde cada moneda se caracteriza por tener una rentabilidad y un riesgo diferentes. Este trabajo plantea la aplicación de un modelo de optimización, utilizando el Excel, con el cual se permite la creación de portafolios eficientes, partiendo de la teoría de Harry Markowitz. Mediante la aplicación de dicho modelo se puede construir la frontera eficiente, al igual que hallar datos de gran importancia para la toma de decisiones respecto a la selección de activos. El resultado de la aplicación del modelo para este caso en particular arrojó un portafolio compuesto por 6 divisas, entre las que se encuentran el euro, la libra esterlina, el real brasilero, el peso colombiano, el franco suizo y el peso chileno, mezcla con la cual se logra superar la rentabilidad del benchmark y de la tasa libre de riesgo (bonos del tesoro americano), al igual que su riesgo, arrojando como resultado una rentabilidad anual del 8,76%, para un riesgo de 6,33%.Foreign currency market offers a wide array of options, where each currency shows different return and risk levels. The present paper proposes the application of an optimization model using Excel, by which efficient portfolios are obtained, based on Markowitz’s theory. The efficient frontier may be constructed from the application of the mentioned model. Important information needed by the structurer, in order to make decisions on the assets selection for a new portfolio, may be obtained as well. By simulating portfolios made of different assets, it is possible to find the optimal mix that allows for achieving higher returns and lower risk than that of the market, or those which satisfy the investor’s expected return and risk levels. The result of applying the model to this particular case presents a portfolio made of six different currencies: Euro, Pound Sterling, Brazilian Real, Colombian Peso, Swiss Franc and Chilean Peso. This mixture manages to outperform both the return level of the benchmark and the risk-free rate (American Treasury Bonds), as well as their risk levels, resulting in an annual return of 8,6%, and a 6,33% risk level

Post weaning growth of alpine and nubian crossbred young goats supplemented with multinutritional blocks

Se realizó un ensayo en una explotación de cabras mestizas lecheras del Municipio Jesús Enrique Losada del estado Zulia, ubicada en una zona de bosque muy seco tropical, con el objeto de evaluar el efecto de suplementación con bloques multinutricionales sobre el crecimiento en cabritonas mestizas Alpinas y Nubian. Se utilizaron 17 cabritonas en estabulación con alimentación tradicional de la granja, siendo agrupadas en dos tratamientos: T1: mezcla de yacija-harina de maíz (70 y 30%) y heno ad limitum (n=10) y T2: la misma dieta más bloques multinutricionales (n=7), durante 70 días con mediciones cada 14 días. Los datos obtenidos fueron analizados a través de un ANAVA (SAS). La ganancia de peso e incremento en perímetro torácico diarios y totales fueron significativamente mayores (P<0.05) en las cabritonas suplementadas con bloques Vs las no suplementadas: 36 Vs 50 g/día, 6.77 Vs 3.54 kg total; 0.07 vs 0.03 cm/día y 3.09 Vs 1.56 cm total para ambos grupos respectivamente. Los incrementos en alzada a la cruz y cadera no mostraron diferencias significativas (P<0.05). Se concluye que la suplementación con bloques mejoró el crecimiento constituyéndose en una práctica recomendable para cabritonas en crecimiento en estas condiciones ambientales.215 - 220CuatrimestralAn experiment was realized to evaluate the effect of a supplement of multinutritional blocks in growth using Alpine and Nubian crossbred young dairy-goats; it was carried out in a farm of crossbred dairy-goats located at the municipality of Jesus Enrique Lossada in the Zulia state, situated in a very dry tropical forest. Seventeen young stabled dairy-goats were used and were given the traditional food management divided into two treatments: T1: mixture of poultry manure conrflour (70-30%) and hay ad libitum (n=10) and T2: the same ration plus multinutritional blocks (n=7) for 700 days with measurements every 14 days. The data were analyzed thoughd the ANAVA (SAS) procedure, the daily and total gain in weight and the increase in thoracic perimeter were significantly higher (P<0.05) in the young dairy-goats supplemented with blocks Vs no supplemented: 96 Vs 50 g/day, 6.77 Vs 3.54 kg in total, 0.07 vs 0.03 cm/day and 3.09 vs 1.56 cm in total for both groups, respectively. The increase in elevation in withers and hips didn’t show significant differences (P>0.05). The conclusion is a that the supplementation with blocks improved growth, establishing a recommendable method of growth for young dairy-goats in these tropical conditions