182 research outputs found

    Integrated geophysical and aerial sensing methods for archaeology: A case history in the Punic site of Villamar (Sardinia, Italy)

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    In this paper, the authors present a recent integrated survey carried out on an archaeological urban site, generally free of buildings, except some temporary structures related to excavated areas where multi-chamber tombs were found. The two methods used to investigate this site were thermal infrared and ground penetrating radar (GPR). The thermography was carried out with the sensor mounted under a helium balloon simultaneously with a photographic camera. In order to have a synthetic view of the surface thermal behavior, a simplified version of the existing night thermal gradient algorithm was applied. By this approach, we have a wide extension of thermal maps due to the balloon oscillation, because we are able to compute the maps despite collecting few acquisition samples. By the integration of GPR and the thermal imaging, we can evaluate the depth of the thermal influence of possible archaeological targets, such as buried Punic tombs or walls belonging to the succeeding medieval buildings, which have been subsequently destroyed. The thermal anomalies present correspondences to the radar time slices obtained from 30 to 50 cm. Furthermore, by superimposing historical aerial pictures on the GPR and thermal imaging data, we can identify these anomalies as the foundations of the destroyed building

    The Relaxation Properties of Myofibrils Are Compromised by Amino Acids that Stabilize α-Tropomyosin

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    We investigated the functional impact of α-tropomyosin (Tm) substituted with one (D137L) or two (D137L/G126R) stabilizing amino acid substitutions on the mechanical behavior of rabbit psoas skeletal myofibrils by replacing endogenous Tm and troponin (Tn) with recombinant Tm mutants and purified skeletal Tn. Force recordings from myofibrils (15°C) at saturating [Ca(2+)] showed that Tm-stabilizing substitutions did not significantly affect the maximal isometric tension and the rates of force activation (k(ACT)) and redevelopment (k(TR)). However, a clear effect was observed on force relaxation: myofibrils with D137L/G126R or D137L Tm showed prolonged durations of the slow phase of relaxation and decreased rates of the fast phase. Both Tm-stabilizing substitutions strongly decreased the slack sarcomere length (SL) at submaximal activating [Ca(2+)] and increased the steepness of the SL-passive tension relation. These effects were reversed by addition of 10 mM 2,3-butanedione 2-monoxime. Myofibrils also showed an apparent increase in Ca(2+) sensitivity. Measurements of myofibrillar ATPase activity in the absence of Ca(2+) showed a significant increase in the presence of these Tms, indicating that single and double stabilizing substitutions compromise the full inhibition of contraction in the relaxed state. These data can be understood with the three-state (blocked-closed-open) theory of muscle regulation, according to which the mutations increase the contribution of the active open state in the absence of Ca(2+) (M(−)). Force measurements on myofibrils substituted with C-terminal truncated TnI showed similar compromised relaxation effects, indicating the importance of TnI-Tm interactions in maintaining the blocked state. It appears that reducing the flexibility of native Tm coiled-coil structure decreases the optimum interactions of the central part of Tm with the C-terminal region of TnI. This results in a shift away from the blocked state, allowing myosin binding and activity in the absence of Ca(2+). This work provides a basis for understanding the effects of disease-producing mutations in muscle proteins

    The homozygous K280N troponin T mutation alters cross-bridge kinetics and energetics in human HCM

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    Hypertrophic cardiomyopathy (HCM) is a genetic form of left ventricular hypertrophy, primarily caused by mutations in sarcomere proteins. The cardiac remodeling that occurs as the disease develops can mask the pathogenic impact of the mutation. Here, to discriminate between mutation-induced and disease-related changes in myofilament function, we investigate the pathogenic mechanisms underlying HCM in a patient carrying a homozygous mutation (K280N) in the cardiac troponin T gene (TNNT2), which results in 100% mutant cardiac troponin T. We examine sarcomere mechanics and energetics in K280N-isolated myofibrils and demembranated muscle strips, before and after replacement of the endogenous troponin. We also compare these data to those of control preparations from donor hearts, aortic stenosis patients (LVHao), and HCM patients negative for sarcomeric protein mutations (HCMsmn). The rate constant of tension generation following maximal Ca2+ activation (k ACT) and the rate constant of isometric relaxation (slow k REL) are markedly faster in K280N myofibrils than in all control groups. Simultaneous measurements of maximal isometric ATPase activity and Ca2+-activated tension in demembranated muscle strips also demonstrate that the energy cost of tension generation is higher in the K280N than in all controls. Replacement of mutant protein by exchange with wild-type troponin in the K280N preparations reduces k ACT, slow k REL, and tension cost close to control values. In donor myofibrils and HCMsmn demembranated strips, replacement of endogenous troponin with troponin containing the K280N mutant increases k ACT, slow k REL, and tension cost. The K280N TNNT2 mutation directly alters the apparent cross-bridge kinetics and impairs sarcomere energetics. This result supports the hypothesis that inefficient ATP utilization by myofilaments plays a central role in the pathogenesis of the disease

    Report on identification of keystone species and processes across regional seas. DEVOTES FP7 Project

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    WP6, Deliverable 6.1, DEVOTES ProjectIn managing for marine biodiversity, it is worth recognising that, whilst every species contributes to biodiversity, each contribution is not of equal importance. Some have important effects and interactions, both primary and secondary, on other components in the community and therefore by their presence or absence directly affect the biodiversity of the community as a whole. Keystone species have been defined as species that have a disproportionate effect on their environment relative to their abundance. As such, keystone species might be of particular relevance for the marine biodiversity characterisation within the assessment of Good Environmental Status (GEnS), for the Marine Strategy Framework Directive (MSFD).The DEVOTES Keystone Catalogue and associated deliverable document is a review of potential keystone species of the different European marine habitats. The catalogue has 844 individual entries, which includes 210 distinct species and 19 groups classified by major habitat in the Baltic Sea, North East Atlantic, Mediterranean, Black Sea (EU Regional Seas) and Norwegian Sea (Non-­‐EU Sea). The catalogue and the report make use/cite 164 and 204 sources respectively. The keystones in the catalogue are indicated by models, by use as indicators, by published work (e.g. on traits and interactions with other species), and by expert opinion based on understanding of systems and roles of species/groups. A total of 74 species were considered to act as keystone predators, 79 as keystone engineers, 66 as keystone habitat forming species, while a few were thought of having multiple roles in their marine ecosystems. Benthic invertebrates accounted for 50% of the reported keystone species/groups, while macroalgae contributed 17% and fish12%. Angiosperms were consistently put forward as keystone habitat forming and engineering species in all areas. A significant number of keystones were invasive alien species.Only one keystone, the bivalve Mya arenaria, was common to all four EU regional seas. The Mediterranean Sea had the largest number of potential keystones (56% of the entries) with the least in the Norwegian Sea. There were very few keystones in deep waters (Bathyal-­‐Abyssal, 200+ m), with most reported in sublittoral shallow and shelf seabeds or for pelagic species in marine waters with few in reduced/variable salinity waters. The gaps in coverage and expertise in the catalogue are analysed at the habitat and sea level, within the MSFD biodiversity component groups and in light of knowledge and outputs from ecosystem models (Ecopath with Ecosim).The understanding of keystones is discussed as to when a species may be a dominant or keystone with respect to the definition term concerning ‘disproportionate abundance’, how important are the ‘disproportionate effects’ in relation to habitat formers and engineers, what separates a key predator and key prey for mid-­‐trophic range species and how context dependency makes a species a keystone. Keystone alien invasive species are reviewed and the use of keystone species model outputs investigated. In the penultimate sections of the review the current level of protection on keystone species and the possibilities for a keystone operational metric and their use in management and in GEnS assessments for the MSFD are discussed. The final section highlights the one keystone species and its interactions not covered in the catalogue but with the greatest impact on almost all marine ecosystems, Homo sapiens

    Estudio de Seeing en la Zona del Cerro ChampaquĂ­ (I)

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    Resumen: Se reportan los resultados del estudio mĂĄs reciente de seeing que hemos realizado en la zona del Cerro ChampaquĂ­ (2800 m) en el cordĂłn de las Sierras Grandes en la Provincia de CĂłrdoba. Se describe ademĂĄs, el dispositivo DIMM de alta frecuencia construido para este trabajo. Este instrumento se empleĂł en otros muestreos de seeing realizados en las provincias de San Juan y San Luis como parte de un proyecto de bĂșsqueda de sitios con muy baja turbulencia atmosfĂ©rica y adecuados para observaciones con Ăłptica activa y adaptable en el rango infrarrojo cercano, iniciado en 2006. Dos de estos sitios han sido monitoreados un total de 46 noches distribuidas en seis meses del periodo 2011-2012. Los resultados indican que se darĂ­an condiciones de seeing estable, inferior al segundo de arco por prolongados perĂ­odos de tiempo, en al menos un sitio del cordĂłn montañoso del SO de CĂłrdoba y NE de San Luis.Abstract: Abstract. We report the results of the most recent seeing feasibility study performed in the region of Cerro ChampaquĂ­ (2800 m) at the mountain range of Sierras Grandes at the Province of CĂłrdoba. We also describe the high frequency DIMM device built for this and other seeing samplings obtained at the provinces of San Juan, San Luis and CĂłrdoba. This work is part of a long term project started in 2006, in search of sites of very low turbulence and suited for near infrared telescopes with active and adaptive optics. Two of the sites have been monitored during a total of 46 nights distributed in six months of the period 2011-2012. The preliminary results suggest the existence of ‘sub-arcsecond’ seeing conditions during extended periods of time in at least one location in the mountain range in the SW of CĂłrdoba and NE of San Luis provinces.www.astronomiaargentina.orgpublishedVersionFil: DĂ­az, RubĂ©n JoaquĂ­n. Universidad Nacional de CĂłrdoba. Observatorio AstronĂłmico de CĂłrdoba; Argentina.Fil: DĂ­az, RubĂ©n JoaquĂ­n. Conicet, Instituto de Ciencias AstronĂłmicas, de la Tierra y del Espacio. Argentina.MeteorologĂ­a y Ciencias AtmosfĂ©rica

    Sertoli Cells as potential Pharmaceutical Carriers: uptake and stability

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    Sertoli cells (SC) have been used for their immunomodulatory properties in cell transplants (Emerich et al., 2003). Moreover, SC themselves may prevent immune rejection (Sipone et al., 2006) and possess a natural phagocytic activity: the latter may make them suitable as biocompatible drug delivery carriers. Porcine SC were loaded with PLA microspheres containing pharmaceutical agents (SC-MS). Phagocytosis was monitored over 24 hours; the uptake was measured by HPLC at fixed time points and followed up through 6 days. SC viability and morphology were monitored together with reactive oxygen species (ROS), DNA damage and parameters of SC functionality and immunomodulatory properties over time. A preliminary antibacterial activity was assessed in vitro. SC-MS were cryopreserved in liquid nitrogen and after plating underwent the same characterization. SC internalized drug loaded MS with an uptake rate of about 20% at 5 hours, that increased by 30% until day two. The uptake was stable up to 6 days with no differences in ROS, DNA damage, functional and immunomodulatory properties observed between control and loaded SC, even after cryopreservation/thawing. A spontaneous in vitro activity against pseudomonas strain, presented with SC alone, increased in presence of MS, and was maintained after cryoperservation. These results encourage further studies to understand the real potential of SC as drug delivery vehicles in trials in “in vivo” animal models

    Ecological indicators to capture the effects of fishing on biodiversityand conservation status of marine ecosystems

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    IndiSeas (“Indicators for the Seas”) is a collaborative international working group that was established in2005 to evaluate the status of exploited marine ecosystems using a suite of indicators in a comparative framework. An initial shortlist of seven ecological indicators was selected to quantify the effects of fishing on the broader ecosystem using several criteria (i.e., ecological meaning, sensitivity to fishing, data avail-ability, management objectives and public awareness). The suite comprised: (i) the inverse coefficient of variation of total biomass of surveyed species, (ii) mean fish length in the surveyed community, (iii)mean maximum life span of surveyed fish species, (iv) proportion of predatory fish in the surveyed community, (v) proportion of under and moderately exploited stocks, (vi) total biomass of surveyed species,and (vii) mean trophic level of the landed catch. In line with the Nagoya Strategic Plan of the Convention on Biological Diversity (2011–2020), we extended this suite to emphasize the broader biodiversity and conservation risks in exploited marine ecosystems. We selected a subset of indicators from a list of empirically based candidate biodiversity indicators initially established based on ecological significance to complement the original IndiSeas indicators. The additional selected indicators were: (viii) mean intrinsic vulnerability index of the fish landed catch, (ix) proportion of non-declining exploited species in the surveyed community, (x) catch-based marine trophic index, and (xi) mean trophic level of the surveyed community. Despite the lack of data in some ecosystems, we also selected (xii) mean trophic level of the modelled community, and (xiii) proportion of discards in the fishery as extra indicators. These additional indicators were examined, along with the initial set of IndiSeas ecological indicators, to evaluate whether adding new biodiversity indicators provided useful additional information to refine our under-standing of the status evaluation of 29 exploited marine ecosystems. We used state and trend analyses,and we performed correlation, redundancy and multivariate tests. Existing developments in ecosystem-based fisheries management have largely focused on exploited species. Our study, using mostly fisheries independent survey-based indicators, highlights that biodiversity and conservation-based indicators are complementary to ecological indicators of fishing pressure. Thus, they should be used to provide additional information to evaluate the overall impact of fishing on exploited marine ecosystems
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