Screening \u3ci\u3eBrachiaria\u3c/i\u3e Introductions for Resistance to Spittlebugs (Homoptera: Cercopidae)

Spittlebugs are the most evident and damaging pests of Signal grasses (Brachiaria) in tropical America. Damage caused by these insects can result in the complete loss of available forage, thereby reducing the carrying capacity of infested pastures. Host plant resistance is a low-cost method of controlling insects. High level of spittlebug resistance is found in the cultivar Marandu (B. brizantha), but it requires more fertile soils. Brachiaria germplasm provided by the International Center for Tropical Agriculture (CIAT) is available at National Beef Cattle Research Center of the Brazilian Agricultural Research Corporation (Embrapa Beef Cattle) and it is being screened for spittlebug resistance. In the present study, 23 introductions of Brachiaria were evaluated for resistance to the spittlebug Deois flavopicta, based on the parameters: nymphal survival and nymphal period. The introductions CIAT 16125 and CIAT 16309, both B. brizantha, were selected as resistant in this test. Given the great number of available introductions and hybrids, tests like this have been conducted routinely at Embrapa Beef Cattle. A total of 551 introductions and hybrids have already been screened in the past few years. As a result 40 introductions and 11 hybrids were found resistant. The aim of continuing evaluations is to release new spittlebug resistant Brachiaria cultivars

Selecting New \u3ci\u3eBrachiaria\u3c/i\u3e for Brazilian Pastures

Brazilian beef production relies heavily on cultivated pastures, of which about 80% are planted mainly to two Brachiaria cultivars. The narrowness of diversity associated with reproduction by apomixis of most plants in this genus prompted an intense search for new cultivars amongst recently collected and introduced ecotypes from Africa. This paper reports results for a three-year evaluation of 21 pre-selected ecotypes in two typical Cerrado ecosystems. Plots, replicated four times, were seeded in rows and cut every 6 weeks during the rainy season followed by a cut in the middle and one at the end of the dry season. Significant differences were found between ecotypes, seasons and years for total, leaf or leaf + stem dry matter production, percentage of leaves, leaf: stem ratio and regrowth rate. Ecotypes differed in the two ecosystems for percentage of leaves, leaf: stem ratio and regrowth. Superior ecotypes (BRA004308, 003361, 002844, 003204, 003441) could be identified and were equally advantageous in both ecosystems

Caracterização de uma conta de vidro proveniente do povoado fortificado calcolítico da Moita da Ladra (Vila Franca de Xira)

The full excavation of the fortified Chalcolithic settlement of Moita da Ladra by one of us (J.L.C.) has shown the existence of a single archaeological layer corresponding to the occupation of the site during the second half of the 3rd millennium BC. Among the archaeological remains collected during the field campaigns there is a bead, with a spheroid shape, longitudinally fractured, presenting a black matrix with numerous whitish spots. The fracture presents a vitreous greasy surface, and exposes a suspension cylindrical bore. Various techniques were used to identify the material that was used in the manufacture of the artifact, including CHN elemental analysis, EDXRF, μ-PIXE and XRD, conducted by the other authors. It was found that the material is not organic (carbon is absent), presenting significant amounts of the elements Si, K, Ca, Ti, Fe, Sr, Zr, and Sb. The X-ray diffraction spectra indicates that the material has an essentially vitreous nature, being the whitish particles dispersed in the vitreous mass identified as quartz. μ-PIXE results show a chemical composition that is consistent with an artificial glass, which implies a much more recent chronology for the bead than that of the Chalcolithic archaeological layer where it was recovered. Thus, although the bead was recorded from a Chalcolithic context, its provenance must be ascribed to the Late Bronze Age occupation recorded nearby and resulting from the early Phoenician trade.info:eu-repo/semantics/publishedVersio

Determinants of the income velocity of money in Portugal: 1891–1998

This paper performs a long-run time series analysis of the behaviour of the income velocity of money in Portugal between 1891 and 1998 by assessing the importance of both macroeconomic and institutional factors and looking for particularities in the Portuguese case. We estimate two cointegration vectors for the income velocity of money, macroeconomic variables and institutional variables. It is apparent that one of these vectors reflects the relationship between income velocity and macroeconomic variables, while the other reflects the relationship between income velocity and institutional variables. Moreover, a regression analysis reveals that the usual U-shaped pattern is displayed with a relatively late inflection point located around 1970, which is consistent with the Spanish case. It is further noted that this is a feature of countries with a late economic and institutional development process.info:eu-repo/semantics/publishedVersio

The Composition of the São Brás Copper Hoard in Relation to the Bell Beaker Metallurgy in the South-western Iberian Peninsula

A large ceramic vessel was discovered at São Brás (southern Portugal) containing a metallic hoard from the Chalcolithic/Early Bronze Age period. These weapons and tools were characterized by microanalytical techniques as being composed of copper with varying arsenic contents (2.2± 1.6 wt%) and minor amounts of lead, bismuth and iron. The collection shows a clear association between daggers and copper with a higher arsenic content, which can be explained by the high status of these silvery alloys. Finally, the compositional distribution of the hoard was compared with the metallurgy of the Bell Beaker and non–Bell Beaker communities inhabiting the south-western Iberian Peninsula.info:eu-repo/semantics/acceptedVersio

The structure of a recent nova shell as observed by ALMA

High resolution ALMA observations of the recent (2.52 yr old) shell of Nova V5668 Sgr (2015) show a highly structured ionized gas distribution with small (10^15 cm) clumps. These are the smallest structures ever observed in the remnant of a stellar thermonuclear explosion. No extended contiguous emission could be found above the 2.5σ level in our data, while the peak hydrogen densities in the clumps reach 10^6 cm^−3. The millimetre continuum image suggests that large scale structures previously distinguished in other recent nova shells may result from the distribution of bright unresolved condensations.publishe