1,399 research outputs found

    Erupciones Volcánicas de la Cuenca de México y sus effectos en poblaciones humanas tempranas del Pleistoceno Superior-Holoceno Temprano.

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    La Cuenca de México esta situada a una altura de 2,500 metros y se localiza dentro del Eje Volcánico Transmexicano. Todas las montañas que rodean a la Cuenca son de origen volcánico. En particular 3 erupciones volcánicas importantes de tipo Pliniano produjeron depósitos volcánicos asociados con cenizas volcánicas “marcadoras” en la Cuenca producidas durante la transición del Pleistoceno Superior – Holoceno Temprano. Estas son: 1) Gran Ceniza Basáltica, producida por la Sierra de Santa Catarina, con una edad de 28,600 años; 2) Pómez con Andesita producida por el Volcán Popocatépetl hace14,600 años 3) Pómez Toluca Superior (Tripatita) producida por el Volcán Nevado de Toluca, hace 10,500 años. Durante este intervalo de tiempo se tienen fechados varios sitios Paleoindios con la presencia tanto de esqueletos humanos embebidos en ceniza volcánica asociada con la Pómez Toluca Superior (Hombre del Metro Balderas), asi como sitios con megafauna asociada con lahares (flujos de lodo volcánico) en el sitio de Mamuts de Tocuila. Las erupciones volcánicas tuvieron un impacto muy importante tanto en el medio ambiente de la Cuenca asi como en las poblaciones humanas Paleoindias y la megafauna asociada (mamuts, camellos, caballos, gliptodontes) durante la transición del Pleistoceno-Holoceno Temprano

    Erupciones Volcánicas de la Cuenca de México y sus effectos en poblaciones humanas tempranas del Pleistoceno Superior-Holoceno Temprano.

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    La Cuenca de Mexico esta situada a una altura de 2,500 metros y se localiza dentro del Eje Volcánico Transmexicano. Todas las montañas que rodean la Cuenca son de origen volcánico. En particular 3 erupciones volcánicas de tipo Pliniano produjeron depósitos volcanicos asociados con cenizas volcánicas marcadoras en la Cuenca producidas durante la transición del Pleistoceno-Holoceno Superior. Estas son: 1) Gran Ceniza Basáltica, producida por la Sierra de Santa Catarina, con una edad de 28,600 años; 2) Pómez con Andesita producida por el Volcán Popocatépetl hace14,600 años y 3) Pómez Toluca Superior (Tripatita) producida por el Volcán Nevado de Toluca, hace 10,500 años. Durante este intervalo de tiempo se tienen fechados, varios sitios Paleoindios con la presencia tanto de esqueletos humanos embebidos en ceniza volcánica asociada con la Pomez Toluca Superior (Hombre del Metro Balderas), asi como sitios con megafauna asociada con lahares (flujos de lodo volcánico) en los sitios de Mamutes de Tocuila. Las erupciones volcanicas han tenido un impacto muy importante tanto en el medio ambiente de la Cuenca asi como en las poblaciones humanas Paleoindias y la megafauna asociada (mamutes, camellos, gliptodontes) durante la transición del Pleistoceno-Holoceno Superior

    Computer-aided display control Final report

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    Human composition and modification of computer driven cathode ray tube displa

    Five Younger Dryas black mats in Mexico and their stratigraphic and paleoenvironmental context

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    The Younger Dryas interval (YD) was a period of widespread, abrupt climate change that occurred between 12,900 and 11,700 cal yr BP (10,900–10,000 14 C BP). Many sites in the Northern Hemisphere preserve a sedimentary record across the onset of the YD interval, including sites investigated in sedimentary basins located in central Mexico (Chapala, Cuitzeo, Acambay), the Basin of Mexico (Tocuila), and northern Mexico (El Cedral). Deposits consist of lacustrine or marginal lake sediments that were deposited during the Pleistocene and the Holocene. At the Tocuila and Acambay sites, Pleistocene fossil vertebrate assemblages, mainly mammoths (Mammuthus columbi), are found in association with a distinctive organic layer, sometimes called the black mat that formed during the YD. At the Chapala, Cuitzeo, Acambay, and Tocuila sites the black mats contain a suite of distinctive microscopic and mineralogical signatures and are accompanied by a sharp change in the depositional environments as supported by diatom and pollen studies reported here. The signatures include magnetic, Fe-rich microspherules, silica melted droplets with aerodynamic shapes (tektites), large amounts of charcoal, and sometimes nanodiamonds (Cuitzeo), all of which were deposited at the onset of the YD. The geochemistry of the microspherules indicates that they are not anthropogenic, authigenic or of cosmic or volcanic origin, and instead, were produced by melting and quenching of terrestrial sediments. Here, we present the stratigraphy at five field sites, the analyses of magnetic microspherules, including major element composition and scanning electron microscopy images. All of these materials are associated with charcoal and soot, which are distinctive stratigraphic markers for the YD layer at several sites in Mexico. © 2017 Springer Science+Business Media B.V

    Cumulative Burden of Morbidity Among Testicular Cancer Survivors After Standard Cisplatin-Based Chemotherapy: A Multi-Institutional Study

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    Purpose In this multicenter study, we evaluated the cumulative burden of morbidity (CBM) among > 1,200 testicular cancer survivors and applied factor analysis to determine the co-occurrence of adverse health outcomes (AHOs). Patients and Methods Participants were ≤ 55 years of age at diagnosis, finished first-line chemotherapy ≥ 1 year previously, completed a comprehensive questionnaire, and underwent physical examination. Treatment data were abstracted from medical records. A CBM score encompassed the number and severity of AHOs, with ordinal logistic regression used to assess associations with exposures. Nonlinear factor analysis and the nonparametric dimensionality evaluation to enumerate contributing traits procedure determined which AHOs co-occurred. Results Among 1,214 participants, approximately 20% had a high (15%) or very high/severe (4.1%) CBM score, whereas approximately 80% scored medium (30%) or low/very low (47%). Increased risks of higher scores were associated with four cycles of either ifosfamide, etoposide, and cisplatin (odds ratio [OR], 1.96; 95% CI, 1.04 to 3.71) or bleomycin, etoposide, and cisplatin (OR, 1.44; 95% CI, 1.04 to 1.98), older attained age (OR, 1.18; 95% CI, 1.10 to 1.26), current disability leave (OR, 3.53; 95% CI, 1.57 to 7.95), less than a college education (OR, 1.44; 95% CI, 1.11 to 1.87), and current or former smoking (OR, 1.28; 95% CI, 1.02 to 1.63). CBM score did not differ after either chemotherapy regimen ( P = .36). Asian race (OR, 0.41; 95% CI, 0.23 to 0.72) and vigorous exercise (OR, 0.68; 95% CI, 0.52 to 0.89) were protective. Variable clustering analyses identified six significant AHO clusters (χ2 P < .001): hearing loss/damage, tinnitus (OR, 16.3); hyperlipidemia, hypertension, diabetes (OR, 9.8); neuropathy, pain, Raynaud phenomenon (OR, 5.5); cardiovascular and related conditions (OR, 5.0); thyroid disease, erectile dysfunction (OR, 4.2); and depression/anxiety, hypogonadism (OR, 2.8). Conclusion Factors associated with higher CBM may identify testicular cancer survivors in need of closer monitoring. If confirmed, identified AHO clusters could guide the development of survivorship care strategies

    Preserving the impossible: conservation of soft-sediment hominin footprint sites and strategies for three-dimensional digital data capture.

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    Human footprints provide some of the most publically emotive and tangible evidence of our ancestors. To the scientific community they provide evidence of stature, presence, behaviour and in the case of early hominins potential evidence with respect to the evolution of gait. While rare in the geological record the number of footprint sites has increased in recent years along with the analytical tools available for their study. Many of these sites are at risk from rapid erosion, including the Ileret footprints in northern Kenya which are second only in age to those at Laetoli (Tanzania). Unlithified, soft-sediment footprint sites such these pose a significant geoconservation challenge. In the first part of this paper conservation and preservation options are explored leading to the conclusion that to 'record and digitally rescue' provides the only viable approach. Key to such strategies is the increasing availability of three-dimensional data capture either via optical laser scanning and/or digital photogrammetry. Within the discipline there is a developing schism between those that favour one approach over the other and a requirement from geoconservationists and the scientific community for some form of objective appraisal of these alternatives is necessary. Consequently in the second part of this paper we evaluate these alternative approaches and the role they can play in a 'record and digitally rescue' conservation strategy. Using modern footprint data, digital models created via optical laser scanning are compared to those generated by state-of-the-art photogrammetry. Both methods give comparable although subtly different results. This data is evaluated alongside a review of field deployment issues to provide guidance to the community with respect to the factors which need to be considered in digital conservation of human/hominin footprints

    The present and future of serum diagnostic tests for testicular germ cell tumours.

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    Testicular germ cell tumours (GCTs) are the most common malignancy occurring in young adult men and the incidence of these tumours is increasing. Current research priorities in this field include improving overall survival for patients classified as being 'poor-risk' and reducing late effects of treatment for patients classified as 'good-risk'. Testicular GCTs are broadly classified into seminomas and nonseminomatous GCTs (NSGCTs). The conventional serum protein tumour markers α-fetoprotein (AFP), human chorionic gonadotrophin (hCG) and lactate dehydrogenase (LDH) show some utility in the management of testicular malignant GCT. However, AFP and hCG display limited sensitivity and specificity, being indicative of yolk sac tumour (AFP) and choriocarcinoma or syncytiotrophoblast (hCG) subtypes. Furthermore, LDH is a very nonspecific biomarker. Consequently, seminomas and NSGCTs comprising a pure embryonal carcinoma subtype are generally negative for these conventional markers. As a result, novel universal biomarkers for testicular malignant GCTs are required. MicroRNAs are short, non-protein-coding RNAs that show much general promise as biomarkers. MicroRNAs from two 'clusters', miR-371-373 and miR-302-367, are overexpressed in all malignant GCTs, regardless of age (adult or paediatric), site (gonadal or extragonadal) and subtype (seminomas, yolk sac tumours or embryonal carcinomas). A panel of four circulating microRNAs from these two clusters (miR-371a-3p, miR-372-3p, miR-373-3p and miR-367-3p) is highly sensitive and specific for the diagnosis of malignant GCT, including seminoma and embryonal carcinoma. In the future, circulating microRNAs might be useful in diagnosis, disease monitoring and prognostication of malignant testicular GCTs, which might also reduce reliance on serial CT scanning. For translation into clinical practice, important practical considerations now need addressing.The authors would like to acknowledge grant funding from CwCUK/GOSHCC (M.J.M. N.C. grant W1058), SPARKS (M.J.M. N.C. grant 11CAM01), CRUK (N.C. grant A13080) MRC (M.J.M. grant MC_EX_G0800464) and National Health Service funding to the Royal Marsden/Institute of Cancer Research National Institute for Health Research Biomedical Research Centre for Cancer (R.A.H.). The authors also thank the Max Williamson Fund, the Josh Carrick Foundation and The Perse Preparatory School, Cambridge for support.This is the author accepted manuscript. The final version is available fromNature Publishing Group via https://doi.org/10.1038/nrurol.2016.17

    Randomized, Double-Blind, Placebo-Controlled Phase III Study of Tasquinimod in Men With Metastatic Castration-Resistant Prostate Cancer

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    PURPOSE: Tasquinimod, a novel oral therapy targeting the tumor microenvironment, significantly improved progression-free survival (PFS) in a randomized, placebo-controlled phase II trial in men with metastatic castration-resistant prostate cancer (mCRPC). This phase III study was conducted to confirm the phase II results and to detect an overall survival (OS) benefit. PATIENTS AND METHODS: Men with chemotherapy-naïve mCRPC and evidence of bone metastases were assigned (2:1) to receive tasquinimod once per day or placebo until progression or toxicity. The primary end point was radiographic PFS (rPFS; time from random assignment to radiologic progression or death) per Prostate Cancer Working Group 2 criteria and RECIST 1.1. The study had 99.9% power to detect an rPFS hazard ratio (HR) of 0.6 with a two-sided alpha error of .05 and 80% power to detect a target HR of 0.8 for OS, the key secondary end point. RESULTS: In all, 1,245 patients were randomly assigned to either tasquinimod (n = 832) or placebo (n = 413) between March 2011 and December 2012 at 241 sites in 37 countries. Baseline characteristics were balanced between groups: median age, 71 years; Karnofsky performance status ≥ 90%, 77.3%; and visceral metastases, 21.1%. Estimated median rPFS by central review was 7.0 months (95% CI, 5.8 to 8.2 months) with tasquinimod and 4.4 months (95% CI, 3.5 to 5.5 months) with placebo (HR, 0.64; 95% CI, 0.54 to 0.75; P < .001). Median OS was 21.3 months (95% CI, 19.5 to 23.0 months) with tasquinimod and 24.0 months (95% CI, 21.4 to 26.9 months) with placebo (HR, 1.10; 95% CI, 0.94 to 1.28; P = .25). Grade ≥ 3 adverse events were more frequent with tasquinimod (42.8% v 33.6%), the most common being anemia, fatigue, and cancer pain. CONCLUSION: In chemotherapy-naïve men with mCRPC, tasquinimod significantly improved rPFS compared with placebo. However, no OS benefit was observed

    Stock Exchanges and Issuers: A Changing Relationship

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    The nature of the relation between stock exchanges and firms seeking a listing has changed considerably over the past decades. In this paper, we argue that the relationship has lost most of its historic complexity and has almost been reduced to a standardized contract in the sense that there are few contractual properties distinguishing listing on different exchanges apart from granting access to a specific liquidity pool. Analyzing the actual specifications of listing agreements at five major stock exchanges, we demonstrate that the contractual features are converging towards a standardized agreement. Furthermore, we show that some of the functions formerly fulfilled by exchanges are now performed by other institutions. We analyze whether these changes are reflected by policy makers in their efforts to create integrated European capital markets.Die Beziehung zwischen Börsen und Eigenkapitalemittenten hat sich in den vergangenen Jahrzehnten fundamental verändert. In diesem Beitrag argumentieren wir, dass diese Beziehung einer standardisierten Vertragsbeziehung gleicht, die ihre historische Komplexität weitgehend verloren hat. Während Börsen in der Vergangenheit unterschiedlich gestaltete Listinganforderungen an Unternehmen gestellt und durchgesetzt haben, ist heute ihr wesentliches Differenzierungsmerkmal die Liquidität der gehandelten Aktien. Eine Untersuchung der Listinganforderungen von fünf bedeutenden Börsen zeigt, dass die wichtigsten Vertragsbestandteile des Abkommens zwischen Emmittent und Börse weitgehend vereinheitlicht sind. Wir zeigen weiterhin, dass neue Institutionen wie etwa nationale Börsenaufsichtsbehörden einige der früher von Börsen wahrgenommenen Aufgaben übernommen haben. Abschließend untersuchen wir, ob und in welchem Maße diese Veränderungen in den gegenwärtigen Bemühungen zur Schaffung integrierter europäischer Kapitalmärkte berücksichtigt werden
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