2,038 research outputs found

    Iridium to provenance ancient silver

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    © 2017 Elsevier Ltd Trace levels of iridium in ancient silver artefacts can provide information on the sources of silver-bearing ores as well as the technologies used to extract silver. A geographically and chronologically disparate legacy dataset, comprised of Near Eastern objects from the Sasanian and Byzantine Empires (1st Millennium AD) and coins circulating around the Mediterranean in the mid-1st Millennium BC, shows that Ag-Au-Ir log-ratio plots can help identify silver derived from the same mining areas, as well as broadly differentiating between the ore types exploited. Combining trace element and lead isotope analyses through the Pb crustal age of the ore, further delimits interpretations on the compositions and locations of silver ore sources. Furthermore, it is shown that silver artefacts of Near Eastern origin have exceptionally high iridium levels, suggesting a unique silver-bearing ore source, potentially in the Taurus mountain range of southern Anatolia. The wide range of crustal ages identified for ancient Greek coins and Near Eastern objects suggest that the addition of exogenous lead as a silver collector during smelting was common practice in the Near East as early as 475BCE. The practice of mixing silver from different sources has also been identified by triangulating the log-ratio subcomposition plots, Pb crustal ages of the ore from which the silver derived and absolute values of trace levels of gold and iridium in silver artefacts

    The buccal mucosa fenestrated graft for Bracka first stage urethroplasty: experimental study in rabbits

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    Objective To histologically evaluate, in an experimental study in rabbits, the integration process of the buccal mucosa fenestrated graft applied in the corpora cavernosa for Bracka first stage urethroplasty. Materials and Methods A urethral defect was surgically created in 16 male rabbits of the New Zealand breed through the excision of the penile urethra. The urethral defect was corrected by applying buccal mucosa fenestrated graft through two cruciform incisions in the distal portions of its longitudinal axis. The animals were sacrificed at 2, 4, 8 and 12 weeks post surgery and their genitals were subjected to clinical and histological assessment. Results The buccal mucosa fenestrated graft showed complete uptake in all groups, with keratinization squamous metaplasia and mucosal proliferation of the fenestrated areas. The fenestrated graft area represented an increase in length of 25% in length in relation to the original standard graft. Conclusions The fenestrated buccal mucosa graft presented total integration to the adjacent epithelia with re-epithelization of the incision areas of the graft (fenestrations) and no significant inflammatory or scarring reactions when compared to other mucosa transplanted areas; therefore its application is viable in cases of extensive urethral defect whenever the donating area might be insufficient.Federal University of São Paulo Departament of Urology (PO, HB, AR, UBjr, VO, AMjr) Department of Pathology (RD)UNIFESP, Departament of Urology (PO, HB, AR, UBjr, VO, AMjr) Department of Pathology (RD)SciEL

    The Offline Software Framework of the Pierre Auger Observatory

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    The Pierre Auger Observatory is designed to unveil the nature and the origins of the highest energy cosmic rays. The large and geographically dispersed collaboration of physicists and the wide-ranging collection of simulation and reconstruction tasks pose some special challenges for the offline analysis software. We have designed and implemented a general purpose framework which allows collaborators to contribute algorithms and sequencing instructions to build up the variety of applications they require. The framework includes machinery to manage these user codes, to organize the abundance of user-contributed configuration files, to facilitate multi-format file handling, and to provide access to event and time-dependent detector information which can reside in various data sources. A number of utilities are also provided, including a novel geometry package which allows manipulation of abstract geometrical objects independent of coordinate system choice. The framework is implemented in C++, and takes advantage of object oriented design and common open source tools, while keeping the user side simple enough for C++ novices to learn in a reasonable time. The distribution system incorporates unit and acceptance testing in order to support rapid development of both the core framework and contributed user code.Comment: 4 pages, 2 figures, presented at IEEE NSS/MIC, 23-29 October 2005, Puerto Ric

    Periods Of Weed Interference In Maize Crops Cultivated In The First And Second Cycles

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    The interference of weeds in maize production may be reflected in grain yield losses that vary as a function of the density, stage and degree of aggressiveness of the species present. In the agricultural ecosystem, crops and weeds demand light, water, nutrients and space, which are frequently not available in sufficient quantities, leading to competition. The aim of this work was to determine the period of interference of weed plants, in particular of naked crabgrass (Digitaria nuda) on maize crop in the first and second harvest. The treatments were defined as increasing periods of coexistence and increasing control of weed community (7, 14, 21, 28, 35, 42, 49, and 56 days), two more controls, a control including one with weed control until the end of the culture cycle and another with coexistence until the harvest. For each period, were evaluated the stand of maize plants, length of ear, number of grains per row, number of rows per ear, cob, 100-grain weight, and grain productivity. The data obtained were subjected to analysis of variance using the F test, with average treatments compared using Tukey's test at 5% probability. Crop productivity was evaluated by means of regressions, the critical periods of interference were estimated. The critical timing of weed removal was 25 days for both harvests. The critical weed free period was 54 and 27 days for the first and second harvest respectively. For the conditions of the first and second harvest, the critical period of weed control was of 29 and 2 days respectively.3752867287

    Elective appendicovesicostomy in association with monfort abdominoplasty in the treatment of prune belly syndrome

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    OBJECTIVE: To evaluate the role of elective appendicovesicostomy in association with Monfort abdominoplasty to avoid urinary tract infection (UTI) and renal damage in the post-operative follow-up of patients with prune belly syndrome. MATERIALS AND METHODS: We followed 4 patients operated in our institution (UNIFESP) (Monfort, orchidopexy and Mitrofanoff) and compared them to 2 patients treated similarly, but without an appendicovesicostomy, in a second institution (UFBA). We evaluated postoperative clinical complications, UTI and preservation of renal parenchyma. Patients were followed as outpatients with urinalysis, ultrasonography (US) and occasionally with renal scintigraphy. RESULTS: Mean follow-up was 23.5 months. Immediate post-operative course was uneventful. We observed that only one patient with the Mitrofanoff channel persisted with UTI, while the 2 patients used as controls persisted with recurrent pyelonephritis (> 2 UTI year). CONCLUSION: Our data suggest that no morbidity was added by the appendicovesicostomy to immediate postoperative surgical recovery and that this procedure may have a beneficial effect in reducing postoperative UTI events and their consequences by reducing the postvoid residuals in the early abdominoplasty follow-up. However, we recognize that the series is small and only a longer follow-up with a larger number of patients will allow us to confirm our suppositions. We could not make any statistically significant assumptions regarding differences in renal preservation due to the same limitations.Federal University of São Paulo Division of UrologyFederal University of Bahia Division of UrologyUNIFESP, Division of UrologySciEL

    Assessment of the stresses produced on the bone implant/tissue interface to the different insertion angulations of the implant - a three-dimensional analysis by the finite elements method

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    The present study aimed to assess the stresses produced on the surface of the bone tissue around dental implants with three different insertion angulations subjected to axial and oblique loading. The study was created according to the recommendations of the Checklist for Reporting In-vitro Studies (CRIS). The Straumann? bone level RC (4.1 x 10 mm) implant, Cone Morse connection (CM), RC Straumann Variobase? with abutment (3.5 mm) was placed in the region of element 16, with the platform positioned at the height of the bone crest. Three assessment models were produced: model M1 or control - implant perpendicular to the bone crest; model M2 - implant angulated at 17° relative to the bone crest; and model M3 - implant angulated at 30° relative to the bone crest. The masticatory loads were simulated with 100 N of intensity and two loading patterns (axial and oblique) were applied to each model. Then, the models were exported to the finite elements simulation software Ansys Workbench V19.2 (Ansys Inc., Canonsburg, PA, USA). To assess the finite elements, qualitative and quantitative analyses were performed. It was observed that, under axial loading, qualitatively, the peaks occurred in the cavosurface region, palatal aspect in M1 and M2, and buccal aspect in M3. Quantitatively, the greatest angulation resulted in a low stress peak. Under oblique loading, qualitatively, the peaks occurred in the cavosurface region, buccal aspect in the three groups. Quantitatively, the greatest angulation of the implant resulted in an increase in stress peaks on the buccal aspect. Under axial loading, the three insertion angulations of the implant - M1, M2, and M3 - were clinically viable. When subjected to oblique loading, the 30° angulation (M3) suggested a significant risk of bone loss and it was contraindicated

    The Offline Software Framework of the Pierre Auger Observatory

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    To be published in the ProceedingsInternational audienceThe Pierre Auger Observatory is designed to unveil the nature and the origins of the highest energy cosmic rays. The large and geographically dispersed collaboration of physicists and the wide-ranging collection of simulation and reconstruction tasks pose some special challenges for the offline analysis software. We have designed and implemented a general purpose framework which allows collaborators to contribute algorithms and sequencing instructions to build up the variety of applications they require. The framework includes machinery to manage these user codes, to organize the abundance of user-contributed configuration files, to facilitate multi-format file handling, and to provide access to event and time-dependent detector information which can reside in various data sources. A number of utilities are also provided, including a novel geometry package which allows manipulation of abstract geometrical objects independent of coordinate system choice. The framework is implemented in C++, and takes advantage of object oriented design and common open source tools, while keeping the user side simple enough for C++ novices to learn in a reasonable time. The distribution system incorporates unit and acceptance testing in order to support rapid development of both the core framework and contributed user code

    Implant insertion angle and depth : peri-implant bone stress analysis by the finite element method

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    The study aimed to assess the influence of different implant insertion angles and depths on the stresses produced on the surface of peri-implant bone tissue under axial and oblique loading. The entire study followed the recommendations of the Checklist
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