Excavation of a chimpanzee stone tool site in the African rainforest

Chimpanzees from the Tai forest of C?te d'Ivoire produce unintentional flaked stone assemblages at nut-cracking sites, leaving behind a record of tool use and plant consumption that is recoverable with archaeological methods. About 40 kilograms of nutshell and 4 kilograms of stone were excavated at the Panda 100 site. The data unearthed show that chimpanzees transported stones from outcrops and soils to focal points, where they used them as hammers to process foodstuff. The repeated use of activity areas led to refuse accumulation and site formation. The implications of these data for the interpretation of the earliest hominin archaeological record are explored.     

Structure of a thiol monolayer-protected gold nanoparticle at 1.1 A resolution

Structural information on nanometer-sized gold particles has been limited, due in part to the problem of preparing homogeneous material. Here we report the crystallization and x-ray structure determination of a p-mercaptobenzoic acid (p-MBA)-protected gold nanoparticle, which comprises 102 gold atoms and 44 p-MBAs. The central gold atoms are packed in a Marks decahedron, surrounded by additional layers of gold atoms in unanticipated geometries. The p-MBAs interact not only with the gold but also with one another, forming a rigid surface layer. The particles are chiral, with the two enantiomers alternating in the crystal lattice. The discrete nature of the particle may be explained by the closing of a 58-electron shell.     

The unusual nature of recent snowpack declines in the North American cordillera

In western North America, snowpack has declined in recent decades, and further losses are projected through the 21st century. Here, we evaluate the uniqueness of recent declines using snowpack reconstructions from 66 tree-ring chronologies in key runoff-generating areas of the Colorado, Columbia, and Missouri River drainages. Over the past millennium, late 20th century snowpack reductions are almost unprecedented in magnitude across the northern Rocky Mountains and in their north-south synchrony across the cordillera. Both the snowpack declines and their synchrony result from unparalleled springtime warming that is due to positive reinforcement of the anthropogenic warming by decadal variability. The increasing role of warming on large-scale snowpack variability and trends foreshadows fundamental impacts on streamflow and water supplies across the western United States.     

Sensitivity in the estimation of parameters fitted by simple linear regression models in the ratio of blueberry buds to fruits in Chile using percentage counting

Blueberry exporting is an important activity in Chile, with fresh blueberries commanding the highest prices and being among the most exported products to the European and North American markets. To maintain quality in the centres of consumption, farmers must continuously improve the logistics of harvesting and shipping the blueberries. Thus every year they must calculate the production of the orchard well in advance in order to hire staff and ensure the logistic cold chain. For this calculation they use a count of flower buds and a simple linear model of which the slope parameter represents the number of fruits per bud. However, due to the cost of the counting procedure, some producers count only a fraction of each plant (25%, 50% or 100%), and furthermore they do not know what effect the variety and productive age of the plants may have on the estimation. The objective of this work is to measure the impact of the cultivated variety, the age of the plant in productive years, and the percentage of fruits counted in estimating the parameter fruits per bud. The study involved monitoring 310 plants of different varieties and ages distributed in northern, central and southern Chile (over an area of approximately 700 km × 200 km). The parameter was estimated by fitting simple linear regression models (SLRM) as a function of the number of fruits and flower buds. To evaluate the impact on the parameter, the SLRM was fitted considering the variables observed in all the plants, by percentage counted, by variety and by variety-age of the plant. The major findings indicate significant differences in the estimation of the parameter, suggesting that in order to estimate fruits per bud the whole plant must be counted and its age and variety taken into account.     

Characterization of Dissolved Organic Matter from Sewage Sludge using 3D-Fluorescence Spectroscopy and Chemometric Tools

The aim of the present article is to show the possibilities of chemometric tools and the parallel factor analysis (PARAFAC) model, as well as to understand the complexities of the fluorescence emission-excitation matrix (EEM) of water-soluble organic matter (WSOM) extracted from sewage sludge samples obtained with different origins and stabilization procedures. The variation in the composition of WSOM in the different sewage sludge samples could be correlated with the conditions of stabilization; therefore, the use of fluorescence spectroscopy to monitor these changes can be a useful tool to optimize the management of this residual flux, avoiding environmental pollution. However, the “contour density” EEM maps obtained with fluorescence present continuous spectra with different peaks, valleys, and shoulders where manual peak picking can be complicated and subjective, especially in complex matrixes such as sewage sludge. With the PARAFAC algorithm, it is possible to resolve the emission and excitation spectra of the different fluorescence components present in the samples and their contribution to the total fluorescence. Also, the contribution (scores) of the different fluorophors can be coupled with another chemometric tool to provide an effective classification method using the stabilization conditions of sewage sludge as main criterion. In this study, a wide survey of sewage sludge samples (287) was characterized by fluorescence emission-excitation matrix. The final molecular composition of the sewage sludge samples was not related to the stabilization (aerobic vs anaerobic) treatments. However, a sewage sludge classification based on a combined spectroscopic-chemometric approach was obtained, which could be used for the optimization of sewage sludge use in agriculture, minimizing the environmental risks.     

Enhanced resistance to bacterial infection byErwinia carotovora subsp.atroseptica in transgenic potato plants expressing the attacin or the cecropin SB-37 genes

Blackleg and soft rot diseases, caused by the bacteriumErwinia carotovora, are among the diseases that cause important losses in culture and storage of potato. In this paper, we introduced bacterial resistance into potato, via genes encoding for proteins with antibacterial activity. For this purpose, potato clones were transformed either with the gene encoding the acidic attacin protein fromHyalophora cecropia, or with the gene encoding the cecropin analog peptide SB37. These clones were evaluated for soft rot and blackleg resistance, after inoculation with the bacterial strainErwinia carotovora subsp.atroseptica T7. Results reported in this paper indicate that a considerable percentage of the potato clones (15–22%) showed increased resistance to bacterial infection, revealed by reduced severity of blackleg or soft rot symptoms. Expression of the transgenes was demonstrated in some of the clones by Northern blot analysis. This is the first report indicating that expression of the gene encoding for an attacin protein and for the cecropin SB-37 peptide in transgenic potato confers increased resistance to bacterial infection.     

Digital radiography (DR) and imaging analysis for evaluating the penetration and distribution of organic substances used in wood conservation

Consolidation treatments are commonly employed in museum conservation studios for treating biologically deteriorated wooden cultural heritage objects. Impregnation using either a solvent/resin or a polymerizing system is an example of such an intervention, which is often difficult to describe in terms of its behavior within the object’s structure. A new simple method has been devised to evaluate the effectiveness of these impregnation treatments in terms of spatial distribution of consolidant solution. A combination of digital radiography and imaging analysis has permitted to evaluate the degree of penetration of a consolidant and to determine its location within the artifact by studying the X-ray images taken before, during, and after treatment. The adequacy of polymer solutions or their effectiveness as wood consolidants is properties which are often difficult to investigate due to limited visual access to the interior of the object. The proposed method provides an alternative way of studying these parameters through analysis of X-ray attenuation recorded on two images: taken before and after the conservation treatment. The resulting image is then converted into a two-dimensional map of consolidation agent within the object using a straightforward calibration procedure.     

Conception in mares following intrauterine therapy with amikacin

The semisynthetic aminoglycoside amikacin is a potentially valuable antibiotic in broodmare practice due to its efficiency against Gram negative bacteria which have developed resistance to gentamicin. Each of 4 mares conceived when amikacin at 200 ug/ml in buffered extender was used in artificial insemination or as a prebreeding infusion. After intrauterine infusion of 2 g amikacin in 200 ml saline, 4 mares conceived to natural service or insemination with untreated semen after seven hours. In unbuffered saline solutions, amikacin (1 g/100 ml) and gentamicin (1 mg/ml) were spermicidal in vitro.     

A newly established bovine intestinal epithelial cell line is effective for in vitro screening of potential antiviral immunobiotic microorganisms for cattle

We evaluated whether a bovine intestinal epithelial (BIE) cell line could serve as a useful in vitro model system for studying antiviral immune responses in bovine intestinal epithelial cells (IECs) and for the primary screening of immunobiotic microorganisms with antiviral protective capabilities. Immunofluorescent analyses revealed that toll-like receptor 3 (TLR3) was expressed in BIE cells, and the results of real-time quantitative PCR showed that these cells respond to stimulation with poly(I:C) by up-regulating pro-inflammatory cytokines and type I interferons. In addition, we demonstrated that BIE cells are useful for the primary screening of immunobiotic lactic acid bacteria strains which are able to beneficially modulate antiviral immune responses triggered by TLR3 activation in bovine IECs. The characterization of BIE cells performed in the present study represents an important step towards the establishment of a valuable bovine in vitro system that could be used for the development of immunomodulatory feed for bovine hosts.