Ancient tin production: Slags from the Iron Age Carvalhelhos hillfort (NW Iberian Peninsula)

Provenance and production of tin in the Ancient World has since long been a major topic of discussion among archaeologists. In Western Europe, where significant tin ore (cassiterite) deposits are known, only a few remains of ancient tin production, such as tin slags, have been detected. In the present work, elemental and microstructural analyses by WDXRF, SEM-EDS and XRD were performed on recently recognised tin slags from the Iron Age Carvalhelhos hillfort located in NW Iberia, a territory that represents the largest extension with tin mineralisation in Western Europe. Elemental and microstructural characterisation of cassiterite collected in a pilot field survey in the region of the hillfort are presented and discussed, as well as two ceramic fragments that could be part of a smelting structure and an iron slag from the settlement. Results show that the tin slags have variable but high contents in Sn, similarly to Pre-Medieval tin slags found in other Western European areas, but also high contents of Ta and Nb, which specifically distinguish them from other tin slags, such as those found in SW Britain. Tin ores from the hillfort region frequently have Ta and Nb in cassiterite solid solution or as inclusions of columbite group minerals, relating well with the Carvalhelhos tin slags. Up to present, the Carvalhelhos slags are amongst the very few ancient tin slags known in Western Europe, and their study can contribute to a better knowledge on ancient tin sources and trade routes

Fuzzy Subtractive Clustering Technique Applied to Demand Response in a Smart Grid Scope

AbstractThis paper focuses on demand response in a smart grid scope using a fuzzy subtractive clustering technique for modeling demand response. Domestic consumption is classified into profiles in order to favorable cover the adequate modeling. The fuzzy subtractive clustering technique is applied to a case study of domestic consumption demand response with three scenarios and a comparison of the results is presented. The demand response developed model intends to support consumer's decisions given a compromise between the consumption imperative needs and possible economical benefits due to reshape and reschedule

Orientalizing Artifacts from Fraga dos Corvos Rock Shelter in North Portugal

An unusual set of metallic artifacts with orientalizing character, attributed to a late period of the Late Bronze Age (LBA), was found in a shelter in Northern Portugal. Conventional and micro-energy dispersive X-ray fluorescence (XRF) analyses have been performed to determine the metal composition. The microstructures of some artifacts have also been studied under optical and scanning electron microscope (SEM). The results show that most of the items are made of a copper–tin alloy with low lead content and show a recrystallized grained microstructure.Fundação para a Ciência e Tecnologi

Comparison between two common methods for measuring Giardia lamblia susceptibility to antiparasitic drugs in vitro

In this study a comparison between two different methods for measuring the susceptibility of Giardia lamblia trophozoites to metronidazole and albendazole is performed. Modifications of Meloni’s method, based on the loss of adherence of parasites to surfaces, and the Hill method, based on the loss of parasite division capacity, are compared. A logistic model was used to calculate the inhibitory concentrations IC10, IC50 and IC90 that were further compared using the respective standard errors. The results obtained, after contact of parasites with the antiparasitic drugs for 24 h, show that the adherence method is more sensitive than the multiplication method for low and moderate inhibitory concentrations of albendazole. Conversely for metronidazole the multiplication method seems to be more sensitive for high inhibitory concentrations of the drug. For screening the IC50, both methods seem to be effective, however, the inhibition of adherence method have even better performance for the benzimidazole like drugs.info:eu-repo/semantics/publishedVersio

Generation and characterization of a recombinant chimeric protein (rCpLi) consisting of B-cell epitopes of a dermonecrotic protein from Loxosceles intermedia spider venom

AbstractA chimeric protein was constructed expressing three epitopes of LiD1, a dermonecrotic toxin from the venom of Loxosceles intermedia spider. This species is responsible for a large number of accidents involving spiders in Brazil. We demonstrated that the chimeric protein (rCpLi) generated is atoxic and that antibodies previously developed in rabbits against synthetic epitopes reactive with rCpLi in ELISA and immunoblot assays. The antibody response in rabbits against the rCpLi was evaluated by ELISA and we have detected an antibody response in all immunized animals. Overlapping peptides covering the amino acid sequence of the rCpLi were synthesized on a cellulose membrane, and their recognition by rabbit anti-rCpLi serum assessed. Three different antigenic regions were identified. The percentage of inhibition of the dermonecrotic, hemorrhagic and edematogenic activities caused by the recombinant protein LiD1r in naïve rabbits was assessed by pre-incubation with anti-rCpLi antibodies. Anti-rCpLi induced good dermonecrotic and hemorrhagic protection. The levels of protection were similar to the antiboides anti-LiD1r. In summary, we have developed a polyepitope recombinant chimeric protein capable of inducing multiple responses of neutralizing antibodies in a rabbit model. This engineered protein may be a promising candidate for therapeutic serum development or vaccination

Fuzzy cluster validation using the partition negentropy criterion

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-04277-5_24Proceedings of the 19th International Conference, Limassol, Cyprus, September 14-17, 2009We introduce the Partition Negentropy Criterion (PNC) for cluster validation. It is a cluster validity index that rewards the average normality of the clusters, measured by means of the negentropy, and penalizes the overlap, measured by the partition entropy. The PNC is aimed at finding well separated clusters whose shape is approximately Gaussian. We use the new index to validate fuzzy partitions in a set of synthetic clustering problems, and compare the results to those obtained by the AIC, BIC and ICL criteria. The partitions are obtained by fitting a Gaussian Mixture Model to the data using the EM algorithm. We show that, when the real clusters are normally distributed, all the criteria are able to correctly assess the number of components, with AIC and BIC allowing a higher cluster overlap. However, when the real cluster distributions are not Gaussian (i.e. the distribution assumed by the mixture model) the PNC outperforms the other indices, being able to correctly evaluate the number of clusters while the other criteria (specially AIC and BIC) tend to overestimate it.This work has been partially supported with funds from MEC BFU2006-07902/BFI, CAM S-SEM-0255-2006 and CAM/UAM project CCG08-UAM/TIC-442

Os machados Bujões/Barcelos e as origens da metalurgia do bronze na fachada atlântica peninsular

Os artefactos metálicos produzidos durante a Primeira Idade do Bronze (2250‑1250 AC) na Ibéria seguem geralmente modelos e tecnologias conservadoras que, progressivamente, se afastam do utilizado na Europa Ocidental Centro‑Atlântica até que, no Bronze Final, se generaliza a produção de bronzes binários. A introdução dos primeiros bronzes binários parece ocorrer de norte para sul ao longo do Ocidente Ibérico. Protagonistas de tal percurso parecem ser os machados planos de gume largo e aberto de tipo Bujões/Barcelos.Evidências recentes, no Norte Português, de produção de bronzes binários em contextos domésticos do Bronze Médio (1750‑1250 a.C.) associadas à revisão e estudo arqueometalúrgico de anteriores achados do Centro‑Sul de Portugal permitem‑nos reflectir sobre as modalidades de transmissão tecnológica.Iberian produced metallic artefacts during the Early/Middle Bronze Age (2250‑1250 BC) generally follow very conservative models and technologies (namely arsenical copper) that, as time goes by, get farther apart from those in use at Centre‑Atlantic Western Europe, till the Late Bronze Age when production of binary bronze finally sees a late generalization. Know‑how dispersion to produce binary bronze seems to occur from north to south through Western Iberia, the main role in the process being played by broad edged axes of Bujões/Barcelos type. Early production of binary bronze (1750‑1250BC) comes from recent findings in Northern Portugal. This recent evidence and the archaeometallurgical study of ancient finds of axes of the referred types allow the discussion of know‑how transmission modalitie