1,261 research outputs found

    New light on the patria of Arnald of Villanova : the case for Villanova de Jiloca near Daroca

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    Trotula, women's problems, and the professionalization of medicine in the Middle Ages

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    The professionalization of medicine in the twelfth and thirteenth centuries led to an exclusion of women practitioners from the best paid and most respected medical positions. Male doctors controlled the teaching and theory of women's medicine, and their gynecological literature incorporated male experience, understanding and learning. The treatises attributed to Trotula, which survive in nearly 100 manuscripts, were the most popular texts used by academic physicians in the later Middle Ages. Although Georg Kraut's Strassburg edition of 1544 treats the treatises of "Trotula" as a single, unified work, three separate texts circulated in the Middle Ages, and on stylistic and other grounds it is likely that each was written by a different author. Reasonably solid evidence demonstrates the existence of a woman physician at Salerno named Trota or Trotula, but she was not a magistra (as is often asserted), and it seems that she did not write even one of the three texts attributed to her. Instead, she produced a Practica from which extracts appear in a Practica secundum Trotam, which survives as a single mansucript in Madrid, and in De aegritudinum curatione in the Wrociaw (Breslau) Codex Salernitanus. This paper is to be published by the Bulletin of the History of Medicine in 1985

    Consciousness of self and of "personality" in the Renaissance of the twelfth century.

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    Suger's life and personality

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    The text which follows was presented as the introductory paper at the International Symposium on Abbot Suger and Saint-Denis held at Columbia University, 11 April 1981. It gives a brief chronology of Suger's life -- born c. 1081, became abbot 1122, died 1151. Suger, who came from a family of minor knights, tells us almost nothing of his childhood and background. He got early administrative training as a provost of priories in Normandy and Beauce and also served King Louis VI as an emissary. As Abbot of Saint-Denis he served both Louis VI and his son, Louis VII as a counsellor, and during the Second Crusade he acted as regent. His policies showed a consistent preference for negotiated settlement and peace. Suger's three major monuments were his writing, his administrative and financial reforms, and his artistic achievement in the rebuilding and embellishment of the abbey church. On all these he left marks of his own strong sense of self

    Non-Random Spatial Distribution of Impacts in the Stardust Cometary Collector

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    In January 2004, the Stardust spacecraft flew through the coma of comet P81/Wild2 at a relative speed of 6.1 km/sec. Cometary dust was collected at in a 0.1 sq m collector consisting of aerogel tiles and aluminum foils. Two years later, the samples successfully returned to earth and were recovered. We report the discovery that impacts in the Stardust cometary collector are not distributed randomly in the collecting media, but appear to be clustered on scales smaller than approx.10 cm. We also report the discovery of at least two populations of oblique tracks. We evaluated several hypotheses that could explain the observations. No hypothesis was consistent with all the observations, but the preponderance of evidence points toward at least one impact on the central Whipple shield of the spacecraft as the origin of both clustering and low-angle oblique tracks. High-angle oblique tracks unambiguously originate from a noncometary impact on the spacecraft bus just forward of the collector. Here we summarize the observations, and review the evidence for and against three scenarios that we have considered for explaining the impact clustering found on the Stardust aerogel and foil collectors

    Effects of habitat composition and landscape structure on worker foraging distances of five bumblebee species

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    Bumblebees (Bombus spp.) are important pollinators of both crops and wild flowers. Their contribution to this essential ecosystem service has been threatened over recent decades by changes in land use, which have led to declines in their populations. In order to design effective conservation measures it is important to understand the effects of variation in landscape composition and structure on the foraging activities of worker bumblebees. This is because the viability of individual colonies is likely to be affected by the trade-off between the energetic costs of foraging over greater distances and the potential gains from access to additional resources. We used field surveys, molecular genetics and fine resolution remote sensing to estimate the locations of wild bumblebee nests and to infer foraging distances across a 20 km2 agricultural landscape in southern England. We investigated five species, including the rare B. ruderatus and ecologically similar but widespread B. hortorum. We compared worker foraging distances between species and examined how variation in landscape composition and structure affected foraging distances at the colony level. Mean worker foraging distances differed significantly between species. Bombus terrestris, B. lapidarius and B. ruderatus exhibited significantly greater mean foraging distances (551 m, 536 m, 501 m, respectively) than B. hortorum and B. pascuorum (336 m, 272 m, respectively). There was wide variation in worker foraging distances between colonies of the same species, which was in turn strongly influenced by the amount and spatial configuration of available foraging habitats. Shorter foraging distances were found for colonies where the local landscape had high coverage and low fragmentation of semi-natural vegetation, including managed agri-environmental field margins. The strength of relationships between different landscape variables and foraging distance varied between species, for example the strongest relationship for B. ruderatus being with floral cover of preferred forage plants. Our findings suggest that favourable landscape composition and configuration has the potential to minimise foraging distances across a range of bumblebee species. There is thus potential for improvements in the design and implementation of landscape management options, such as agri-environment schemes, aimed at providing foraging habitat for bumblebees and enhancing crop pollination services

    In situ detection of boron by ChemCam on Mars

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    We report the first in situ detection of boron on Mars. Boron has been detected in Gale crater at levels Curiosity rover ChemCam instrument in calcium-sulfate-filled fractures, which formed in a late-stage groundwater circulating mainly in phyllosilicate-rich bedrock interpreted as lacustrine in origin. We consider two main groundwater-driven hypotheses to explain the presence of boron in the veins: leaching of borates out of bedrock or the redistribution of borate by dissolution of borate-bearing evaporite deposits. Our results suggest that an evaporation mechanism is most likely, implying that Gale groundwaters were mildly alkaline. On Earth, boron may be a necessary component for the origin of life; on Mars, its presence suggests that subsurface groundwater conditions could have supported prebiotic chemical reactions if organics were also present and provides additional support for the past habitability of Gale crater

    Molecular and Functional Characterization of the Odorant Receptor2 (OR2) in the Tiger Mosquito Aedes albopictus

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    In mosquitoes, the olfactory system plays a crucial role in many types of behavior, including nectar feeding, host preference selection and oviposition. Aedes albopictus, known also as the tiger mosquito, is an anthropophilic species, which in the last few years, due to its strong ecological plasticity, has spread throughout the world. Although long considered only a secondary vector of viruses, the potential of its vector capacity may constitute a threat to public health. Based on the idea that an improved understanding of the olfactory system of mosquitoes may assist in the development of control methods that interfere with their behavior, we have undertaken a study aimed at characterizing the A. albopictus Odorant Receptors. Here we report the identification, cloning and functional characterization of the AalOR2 ortholog, that represents the first candidate member of the odorant receptor (OR) family of proteins from A. albopictus. AalOR2 is expressed in the larval heads and antennae of adults. Our data indicate that A. albopictus OR2 (AalOR2) shares a high degree of identity with other mosquito OR2 orthologs characterized to date, confirming that OR2 is one of the most conserved mosquito ORs. Our data indicate that AalOR2 is narrowly tuned to indole, and inhibited by (-)-menthone. In agreement with this results, these two compounds elicit two opposite effects on the olfactory-based behavior of A. albopictus larvae, as determined through a larval behavioral assay. In summary, this work has led to the cloning and de-orphaning of the first Odorant Receptor in the tiger mosquito A. albopictus. In future control strategies this receptor may be used as a potential molecular target

    Performance of the LHCb vertex locator

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    The Vertex Locator (VELO) is a silicon microstrip detector that surrounds the proton-proton interaction region in the LHCb experiment. The performance of the detector during the first years of its physics operation is reviewed. The system is operated in vacuum, uses a bi-phase CO2 cooling system, and the sensors are moved to 7 mm from the LHC beam for physics data taking. The performance and stability of these characteristic features of the detector are described, and details of the material budget are given. The calibration of the timing and the data processing algorithms that are implemented in FPGAs are described. The system performance is fully characterised. The sensors have a signal to noise ratio of approximately 20 and a best hit resolution of 4 ÎĽm is achieved at the optimal track angle. The typical detector occupancy for minimum bias events in standard operating conditions in 2011 is around 0.5%, and the detector has less than 1% of faulty strips. The proximity of the detector to the beam means that the inner regions of the n+-on-n sensors have undergone space-charge sign inversion due to radiation damage. The VELO performance parameters that drive the experiment's physics sensitivity are also given. The track finding efficiency of the VELO is typically above 98% and the modules have been aligned to a precision of 1 ÎĽm for translations in the plane transverse to the beam. A primary vertex resolution of 13 ÎĽm in the transverse plane and 71 ÎĽm along the beam axis is achieved for vertices with 25 tracks. An impact parameter resolution of less than 35 ÎĽm is achieved for particles with transverse momentum greater than 1 GeV/c
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