40 research outputs found

    Low molecular weight poly(lactic acid) microparticles for controlled release of the herbicide metazachlor: Preparation, morphology, and release kinetics

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    The preemergence chloroacetamide herbicide metazachlor was encapsulated in biodegradable low molecular weight poly(lactic acid) micro- and submicroparticles, and its release to the water environment was investigated. Three series of particles, S, M, and L, varying in their size (from 0.6 to 8 μm) and with various initial amounts of the active agent (5%, 10%, 20%, 30% w/w) were prepared by the oil-in-water solvent evaporation technique with gelatin as biodegradable surfactant. The encapsulation efficiencies reached were about 60% and appeared to be lower for smaller particles. Generally, it was found that the rate of herbicide release decreased with increasing size of particles. After 30 days the portions of the herbicide released for its highest loading (30% w/w) were 92%, 56%, and 34% for about 0.6, 0.8, and 8 μm particles, respectively. The release rates were also lower for lower herbicide loadings. Metazachlor release from larger particles tended to be a diffusion-controlled process, while for smaller particles the kinetics was strongly influenced by an initial burst release. © 2012 American Chemical Society

    Who lived on the Swiss Plateau around 3300 BCE? Analyses of commingled human skeletal remains from the dolmen of Oberbipp

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    Nowadays, the discovery and excavation of an almost intact Late Neolithic dolmen is rare, as those monuments were often visible in the landscape and have been investigated or destroyed in earlier times; therefore, information about the buried individuals has often been lost. The excavation of the dolmen, a stone grave chamber, from Oberbipp, Switzerland, in 2012 provided a unique opportunity to study human skeletal remains from a Late Neolithic collective burial (3350–2650 BCE). Over 2,000 fragmented and commingled skeletal elements were recovered and form the basis of this morphological study. Established morphological methods were employed to evaluate the minimum number of individuals, age at death, sex, stature, and the presence of pathological alterations and trauma. Sex was determined additionally by aDNA analysis. Elements of the entire human skeleton were recovered indicating a primary burial site. At least 42 individuals (femora) from all age classes (57%:43% adults to subadults) were buried in the dolmen. Based on aDNA analysis (n = 23, partes petrosae) slightly more males than females (44%:35% males to females, 22% indeterminate) were recovered. Stature was estimated from complete femora (n = 3) indicating an average body height between 154–157 cm. Pathological alterations and trauma could be observed on several bones, however, without indications for major interpersonal violence. The caries intensity of Swiss samples seems to be higher compared with other Neolithic European sites. A possible separation of burial areas for males and females based on the recovery of skeletal elements within the dolmen along with aDNA results is postulated. In addition, this article contributes to a better understanding of Late Neolithic populations in Central Europe

    Humeral development from neonatal period to skeletal maturity—application in age and sex assessment

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    The goal of the present study is to examine cross-sectional information on the growth of the humerus based on the analysis of four measurements, namely, diaphyseal length, transversal diameter of the proximal (metaphyseal) end of the shaft, epicondylar breadth and vertical diameter of the head. This analysis was performed in 181 individuals (90 ♂ and 91 ♀) ranging from birth to 25 years of age and belonging to three documented Western European skeletal collections (Coimbra, Lisbon and St. Bride). After testing the homogeneity of the sample, the existence of sexual differences (Student"s t- and Mann-Whitney U-test) and the growth of the variables (polynomial regression) were evaluated. The results showed the presence of sexual differences in epicondylar breadth above 20 years of age and vertical diameter of the head from 15 years of age, thus indicating that these two variables may be of use in determining sex from that age onward. The growth pattern of the variables showed a continuous increase and followed first- and second-degree polynomials. However, growth of the transversal diameter of the proximal end of the shaft followed a fourth-degree polynomial. Strong correlation coefficients were identified between humeral size and age for each of the four metric variables. These results indicate that any of the humeral measurements studied herein is likely to serve as a useful means of estimating sub-adult age in forensic samples

    Fauna Europaea - all European animal species on the web

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    Fauna Europaea is Europe's main zoological taxonomic index, making the scientific names and distributions of all living, currently known, multicellular, European land and freshwater animals species integrally available in one authoritative database. Fauna Europaea covers about 260,000 taxon names, including 145,000 accepted (sub)species, assembled by a large network of (>400) leading specialists, using advanced electronic tools for data collations with data quality assured through sophisticated validation routines. Fauna Europaea started in 2000 as an EC funded FP5 project and provides a unique taxonomic reference for many user-groups such as scientists, governments, industries, nature conservation communities and educational programs. Fauna Europaea was formally accepted as an INSPIRE standard for Europe, as part of the European Taxonomic Backbone established in PESI. Fauna Europaea provides a public web portal at faunaeur.org with links to other key biodiversity services, is installed as a taxonomic backbone in wide range of biodiversity services and actively contributes to biodiversity informatics innovations in various initiatives and EC programs
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