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

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

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

Essential oils of \u3ci\u3eCupressus funebris, Juniperus communis,\u3c/i\u3e and \u3ci\u3eJ. chinensis\u3c/i\u3e (Cupressaceae) as repellents against ticks (Acari: Ixodidae) and mosquitoes (Diptera: Culicidae) and as toxicants against mosquitoes

Juniperus communis leaf oil, J. chinensis wood oil, and Cupressus funebris wood oil (Cupressaceae) from China were analyzed by gas chromatography and gas chromatography-mass spectrometry. We identified 104 compounds, representing 66.8-95.5% of the oils. The major components were: α-pinene (27.0%), α-terpinene (14.0%), and linalool (10.9%) for J. communis; cuparene (11.3%) and δ-cadinene (7.8%) for J. chinensis; and α-cedrene (16.9%), cedrol (7.6%), and β-cedrene (5.7%) for C. funebris. The essential oils of C. funebris, J. chinensis, and J. communis were evaluated for repellency against adult yellow fever mosquitoes, Aedes aegypti (L.), host-seeking nymphs of the lone star tick, Amblyomma americanum (L.), and the blacklegged tick, Ixodes scapularis Say, and for toxicity against Ae. aegypti larvae and adults, all in laboratory bioassays. All the oils were repellent to both species of ticks. The EC95 values of C. funebris, J. communis, and J. chinensis against A. americanum were 0.426, 0.508, and 0.917 mg oil/cm2 filter paper, respectively, compared to 0.683 mg deet/cm2 filter paper. All I. scapularis nymphs were repelled by 0.103 mg oil/cm2 filter paper of C. funebris oil. At 4 h after application, 0.827 mg oil/cm2 filter paper, C. funebris and J. chinensis oils repelled ≥80% of A. americanum nymphs. The oils of C. funebris and J. chinensis did not prevent female Ae. aegypti from biting at the highest dosage tested (1.500 mg/cm2). However, the oil of J. communis had a Minimum Effective Dosage (estimate of ED99) for repellency of 0.029 ± 0.018 mg/cm2; this oil was nearly as potent as deet. The oil of J. chinensis showed a mild ability to kill Ae. aegypti larvae, at 80 and 100% at 125 and 250 ppm, respectivel