122 research outputs found
Stereological estimations and neurochemical characterization of neurons expressing GABAA and GABAB receptors in the rat pedunculopontine and laterodorsal tegmental nuclei
To better understand GABAergic transmission at two targets of basal ganglia downstream projections, the pedunculopontine (PPN) and laterodorsal (LDT) tegmental nuclei, the anatomical localization of GABAA and GABAB receptors was investigated in both nuclei. Specifically, the total number of neurons expressing the GABAA receptor γ2 subunit (GABAAR γ2) and the GABAB receptor R2 subunit (GABAB R2) in PPN and LDT was estimated using stereological methods, and the neurochemical phenotype of cells expressing each subunit was also determined. The mean number of non-cholinergic cells expressing GABAAR γ2 was 9850 ± 1856 in the PPN and 8285 ± 962 in the LDT, whereas those expressing GABAB R2 were 7310 ± 1970 and 9170 ± 1900 in the PPN and LDT, respectively. In addition, all cholinergic neurons in both nuclei co-expressed GABAAR γ2 and 95–98% of them co-expressed GABAB R2. Triple labeling using in situ hybridization revealed that 77% of GAD67 mRNA-positive cells in the PPT and 49% in the LDT expressed GABAAR γ2, while 90% (PPN) and 65% (LDT) of Vglut2 mRNA-positive cells also expressed GABAAR γ2. In contrast, a similar proportion (~2/3) of glutamatergic and GABAergic cells co-expressed GABAB R2 in both nuclei. The heterogeneous distribution of GABAAR and GABABR among non-cholinergic cells in PPN and LDT may give rise to physiological differences within each neurochemical subpopulation. In addition, the dissimilar proportion of GABAAR γ2-expressing glutamatergic and GABAergic neurons in the PPN and LDT may contribute to some of the functional differences found between the two nuclei
Protein diagenesis in archaeological gastropod shells and the suitability of this material for amino acid racemisation dating: Phorcus lineatus (da Costa, 1778)
Abstract: The inter-and intra-crystalline fractions of the topshell Phorcus lineatus recovered from modern specimens and shells from archaeological sites in Northern Spain covering Neolithic, Mesolithic, and Upper Magdalenian periods were examined for amino acidcomposition and racemisation over time. The main loss of proteins from the inter-crystalline fraction occurred within the first 6000 years after the death of the organism. In contrast, the intra-crystalline fraction isolated by bleaching?with a different protein composition to that of the inter-crystalline fraction?appeared to behave like a closed system for at least 12.6 ka, as reflected by the lack of a significant decrease in amino acid content. However, changes in the relative composition of the amino acids present in these shells occurred during this period. The concentration of aspartic acid remained almost constant with age within the intra-crystalline fraction and its contribution to the total amino acid content also remained the same. Good correspondence was obtained between Asx D/L values in unbleached and bleached samples and age, thereby allowing the dating of archaeological sites and the determination of chronometric age.This research was part of the projects HAR2010-22115-C02-01, HAR2010-22115-C02-02, and HAR2013-46802-P, all of them funded by the Spanish Ministry of Economy and Competitiveness. IGZ was supported by the Newton International Fellowships scheme (grant number NF100413) and the Juan de la Cierva Research Programme (grant number This research was part of the projects HAR2010-22115-C02-01, HAR2010-22115-C02-02, and HAR2013-46802-P, all of them funded by the Spanish Ministry of Economy and Competitiveness. IGZ was supported by the Newton International Fellowships scheme (grant number NF100413) and the Juan de la Cierva Research Programme (grant number JCI-2012-12094)
How well is Patella vulgata Linnaeus 1758 reflecting changes in sea surface temperatures (SST)? First results using living and archaeological samples from Northern Spain
Human populations have been exploiting coastal regions in different parts of the planet, at least since the Middle Palaeolithic. In Cantabrian Spain, the study of the exploitation of molluscs and shell middens formation during the late Pleistocene and early Holocene has shown the importance of these resources in human diets, being one of the most commonly collected species the limpet Patella vulgata which is present from the upper Palaeolithic to the Neolithic (ca. 40,000-5700 cal BP)
Shells and humans: molluscs and other coastal resources from the earliest human occupations at the Mesolithic shell midden of El Mazo (Asturias, Northern Spain)
Human populations exploited coastal areas with intensity during the Mesolithic in Atlantic Europe, resulting in the accumulation of large shell middens. Northern Spain is one of the most prolific regions, and especially the so-called Asturian area. Large accumulations of shellfish led some scholars to propose the existence of intensification in the exploitation of coastal resources in the region during the Mesolithic. In this paper, shell remains (molluscs, crustaceans and echinoderms) from stratigraphic units 114 and 115 (dated to the early Mesolithic c. 9 kys cal BP) at El Mazo cave (Asturias, northern Spain) were studied in order to establish resource exploitation patterns and environmental conditions. Species representation showed that limpets, top shells and sea urchins were preferentially exploited. One-millimetre mesh screens were crucial in establishing an accurate minimum number of individuals for sea urchins and to determine their importance in exploitation patterns. Environmental conditions deduced from shell assemblages indicated that temperate conditions prevailed at the time of the occupation and the morphology of the coastline was similar to today (rocky exposed shores). Information recovered relating to species representation, collection areas and shell biometry reflected some evidence of intensification (reduced shell size, collection in lower areas of exposed shores, no size selection in some units and species) in the exploitation of coastal resources through time. However, the results suggested the existence of changes in collection strategies and resource management, and periods of intense shell collection may have alternated with times of shell stock recovery throughout the Mesolithic.This research was performed as part of the project “The human response to the global climatic change in a littoral zone: the case of the transition to the Holocene in the Cantabrian coast (10,000–5000 cal BC) (HAR2010-22115-C02-01)” funded by the Spanish Ministry of Economy and Competitiveness. AGE was funded by the University of Cantabria through a predoctoral grant and IGZ was funded by the Spanish Ministry of Economy and Competitiveness through a Juan de la Cierva grant. We also would like to thank the University of Cantabria and the IIIPC for providing support, David Cuenca-Solana, Alejandro García Moreno and Lucia Agudo Pérez for their help. We also thank Jennifer Jones for correcting the English. Comments from two anonymous reviewers helped to improve the paper
Producción de espacios de conservación en Veracruz, México / Production of conservation spaces in Veracruz, Mexico
Este trabajo examina la producción de espacios concebidos para la conservación, analizando la forma en que se legitiman espacios de verdor, mientras que se generan discursos vacíos de relaciones histórico-sociales. Bajo el modelo del conservacionismo neoliberal, la producción de espacios para la conservación está interconectada con el suministro de agua para la ciudad. Esta generación de espacios existe por sus representaciones, legitimadas con elementos como: mandato de la conservación, espectáculo de la naturaleza, intervención planeada, construcción de identidades y cogestión integral. Estos componentes materializan el espacio verde, proveedor de servicios ambientales para la sociedad urbana en crisis. En este contexto, las resistencias campesinas quedan desactivadas mediante proyectos de desarrollo, haciendo invisible el flujo de los pobladores, quienes quedan inmersos en nuevos cercamientos y despojos verdes y azules. De manera encubierta, las familias reconfiguran sus tiempos y espacios, nostálgica y silenciosamente, en los intersticios de los lugares que antes habitaron.
Protein diagenesis in "Patella" shells: Implications for amino acid racemisation dating
Abstract: The inter- and intra-crystalline fractions of Patella vulgata limpets recovered from archaeological sites in Northern Spain (covering Neolithic, Mesolithic, Magdalenian, Solutrean, and Aurignacian periods) were examined for amino acid composition and racemisation over time. The calcitic apex and rim areas of the shells were found to probably be composed of similar proteins, as the D/L values and amino acids were comparable and varied in the same way with increasing age; however, the mineral structures present in these areas differed. The aragonitic intermediate part of the shell showed a distinctly different amino acid composition and mineral structure. The main protein leaching from the inter-crystalline fraction occurred within the first 6000 yr after the death of the organism. In contrast, the intra-crystalline fraction d comprised of a different protein composition than the inter-crystalline fraction d appeared to behave as a closed system for at least 34 ka, as reflected by the lack of a significant decrease in the amino acid content; however, changes in the amino acid percentages occurred during this period. The concentration of aspartic acid remained almost constant with age both in inter- and intra-crystalline proteins, and its contribution to the total amino acid content increased with age at the expense of other amino acids such as glutamic acid, serine, glycine and alanine. Temperature is thought to play a key role in the amino acid racemisation of P. vulgata and could explain why in the localities belonging to the Gravettian and Solutrean period, which formed during relatively cold conditions, D/L values were similar to those detected in shells from sites formed during the Magdalenian.This paper was made possible by funding from the Spanish Ministry of Science and Innovation projects: HAR2010-22115-C02-01 “La respuesta humana al cambio climático global en una zona litoral: el caso del tránsito al Holoceno en la costa cantábrica (10000-5000 cal BC)”, and HAR2010-22115-C02-02 “Aplicación del análisis de sustancias orgánicas e inorgánicas a la reconstrucción paleoambiental, cronológica y tafonómica de yacimientos arqueológicos del Norte de España”
Cyclodextrin/cellulose hydrogel with gallic acid to prevent wound infection
Cyclodextrin-based hydrogels have been described as suitable for the controlled-release of bioactive molecules to be used as wound dressing. These materials have major advantages, since they gather the hydrogel properties (high degree of swelling and easy manipulation) and the encapsulation ability of cyclodextrins. β-cyclodextrin (β) or hydroxypropyl-β-cyclodextrin (HPβ) was cross-linked (1,4-butanediol diglycidyl ether) with hydroxypropyl methylcellulose under mild conditions. The hydrogels were chemically characterized by swelling degree, FTIR, DSC and contact angle. The gallic acid loading and release was also analysed, as well the antibacterial activity and cytotoxicity of the polymeric networks. The hydrogels obtained were firm and transparent, with good swelling ability. The gel-HPβ had a surface more hydrophilic when compared with the gel-β. Nevertheless, both hydrogels were capable to incorporate gallic acid and sustain the release for 48 h. The antibacterial activity of gallic acid was maintained after its adsorption within the polymeric matrix, as well as, gallic acid effect on fibroblast proliferation. Therefore, gel-β and gel-HPβ conjugated with gallic acid were shown to be a viable option for antibacterial wound dressing.The authors thank the FCT Strategic Projects PEst-OE/EQB/LA0023/2013, PEst-C/CTM/UI0264/2011, the Project "BioHealth-Biotechnology and Bioengineering approaches to improve health quality'', Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional doNorte (ON.2-ONovoNorte), QREN, FEDER, and E. Pinho grant (SFRH/BD/62665/2009)
Shell we cook it? An experimental approach to the microarchaeological record of shellfish roasting
In this paper, we investigate the microarchaeological traces and archaeological visibility of shellfish cooking activities through a series of experimental procedures with direct roasting using wood-fueled fires and controlled heating in a muffle furnace. An interdisciplinary geoarchacological approach, combining micromorphology, FTIR (in transmission and ATR collection modes), TGA and XRD, was used to establish a baseline on the mineralogical transformation of heated shells from aragonite to calcite and diagnostic sedimentary traces produced by roasting fire features. Our experimental design focused on three main types of roasting procedures: the construction of shallow depressions with heated rocks (pebble cuvette experiments), placing shellfish on top of hot embers and ashes (fire below experiment), and by kindling short-lived fires on top of shellfish (fire above experiments). Our results suggest that similar shellfish roasting procedures will largely create microstratigraphic signatures of anthropogenically reworked combusted material spatially "disconnected" from the actual combustion locus. The construction of shallow earth ovens might entail an increased archaeological visibility, and some diagnostic signatures of in situ hearths can be obtained by fire below roasting activities. We also show that macroscopic visual modifications and mineralogical characterization of discarded shellfish might be indicative of specific cooking activities versus secondary burning.Max Planck Societyinfo:eu-repo/semantics/publishedVersio
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