688 research outputs found

    The astrometric recognition of the solar Clementine gnomon (1702)

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    The Clementine gnomon has been built in 1702 to measure the Earth's obliquity variation. For this reason the pinhole was located in the walls of Diocletian's times (305 a. D.) in order to remain stable along the centuries, but its original form and position have been modified. We used an astrometric method to recover the original position of the pinhole: reshaping the pinhole to a circle of 1.5 cm of diameter, the positions of the Northern and Southern limbs have been compared with the ephemerides. A sistematic shift of 4.5 mm Southward of the whole solar image shows that the original pinhole was 4.5 mm North of the actual position, as the images in the Bianchini's book (1703) suggest. The oval shape of the actual pinhole is also wrong. Using a circle the larger solar spots are clearly visible. Some reference stars of the catalogue of Philippe de la Hire (1702), used originally for measuring the ecliptic latitude of the Sun, are written next to the meridian line, but after the last restauration (2000), four of them are wrongly located. Finally the deviation from the true North, of the meridian line's azimuth confirms the value recovered in 1750. This, with the local deviations of a true line, will remain as systematic error, like for all these historical instruments.Comment: 5 pages, 2 figures. Proceedings of the Third Galileo - Xu Guangqi meeting, October 11-15, 2011 National Astronomical Observatories - Beijing (China) The Sun, the Stars, the Universe, and General Relativit

    Geographic distribution of the Gerridae in Argentina (Insect, Heteroptera)

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    Distributional data for the fourteen species of Gerridae known to occur in Argentina are given: Eurygerris fuscinervis (herein first recorded from San Juan and San Luis Provinces), Limnogonus (Limnogonus) aduncus (herein first recorded from Formosa Prov.), L. (L.) ignotus, L. (L.)profugus, L. (Neogerris) lubricus (herein first recorded from Cordoba Prov.), Brachymetra albinerva albinerva (herein first recorded from Salta Prov.), Rheumatobates (Rheumatobates) bonariensis, R. (R.)crassifemur crassifemur (herein first recorded from Santa Fe Prov.), Halobatopsis platensis, H. spiniventris (herein first recorded from Entre Rios Prov.), Metrobates plaumanni plaumanni, M. vigilis, Ovatametra gualeguay (herein first recorded from Buenos Aires Prov.), and Trepobates taylori (herein first recorded from Jujuy Prov.). In addition distributional maps are provided. The species characteristic for each main geographic area of Argentina are: E. fuscineruis and T. taylori for the Northwestern mountainous area; L. ignotus, L. lubricus, and R. crassifemur for the Chacoan plain; L. ignotus and H. platensis for the Bonarian plain; L. ignotus, R. bonariensis, H. platensis and 0 . gualeguay for the Mesopotamian plain. E. fuscinervis and T. taylori are restricted to mountain rivers and rivulets, whereas the remaining species seem to be genuine inhabitants of either rivulets in forested hilly areas (L. aduncus, L. profugus, B. albinerva, H. spiniventris, M. plaumanni and M. vigilis), or rivers, rivulets and ponds in plains (L. ignotus, L. lubricus, R. bonariensis, R. crassifemur, H. platensis, and 0 . gualeguay). L. ignotus is a pioneer species in lowlands, readily colonizing new pools. Excepting L. aduncus, L. profugus, and 0. gualeguay which are rare, the remaining species are common in Argentina (no enough data are available for B. albinerva, M. plaumanni, and M. vigilis). Gregariousness is high in E. fuscinervis, R. bonariensis, R. crassifemur, and H. platensis, and probably also in B. albinerva. The other species mentioned seem not to be gregarious, but 0 . gualeguay appears sometimes in the dense aggregations of H. platensis, suggesting some gregarious tendency

    Morphometry and chaetotaxy of the nymphs of Ectemnostega (Ectemnostegella) quechua (Bachmann 1961) (Insecta: Hemiptera: Heteroptera: Corixidae)

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    The egg and the five nymphal instars of Ectemnostega quechua are described and illustrated for the first time. The eggs of Ectemnostega have a short stalk, and the shape, size and chorionic structure differ among groups of species. The nymphal characters most useful in identifying instars I-V of Ectemnostega are: body length; number of rostrum sulcations; number of setae on inner surface of protibiotarsus; spines and setae, and spines on posteroventral surface of mesofemur and mesotibia, respectively; setae on posterodorsal surface of mesotibia and mesotarsus; spines and setae on anteroventral surface and setae on posterior surface of metatibia; swimming hairs on anteroventral and posterodorsal surfaces of metatarsus; and the grade of development of wing pads. The nymphs of E. quechua can be easily distinguished fromother species of Ectemnostega by the number of spines and setae on the posteroventral surface of mesofemur.Fil: Konopko, Susana Amanda. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mazzucconi, Silvia Ana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Repeated successful use of eltrombopag in chronic primary immune thrombocytopenia: description of an intriguing case.

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    Thrombopoietin receptor agonists (TPO-RAs) are used as effective alternative treatments in ITP patients unresponsive to first-/second-line therapies. TPO- RAs can also be used to normalize platelet count to safely perform invasive pro- cedures and chemotherapy, in case of malignancies. In few responsive patients, TPO-RAs can be suspended maintaining a sustained respons

    Studies on the chorionic structure of the eggs of Corixoidea (Hemiptera: Heteroptera) with scanning electron microscopy

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    The chorionic structure of the eggs of sixteen species of Corixoidea (Ectemnostega (Ectemnostega) quadrata (Signoret), E. (Ectemnostegella) quechua (Bachmann), Trichocorixa mendozana Jaczewski, Centrocorisa kollari (Fieber), Heterocorixa brasiliensis Hungerford, Sigara (Aphelosigara) tucma Bachmann, S. (Tropocorixa) denseconscripta (Breddin), S. (T.) platensis Bachmann, S. (T.) rubyae (Hungerford), S. (T.) santiagiensis (Hungerford), S. (T.) schadei (Hungerford), S. (T.) yala Bachmann, Tenagobia (Incertagobia) incerta Lundblad, T. (Fuscagobia) fuscata (Stål), T. (Schadeogobia) schadei Lundblad, and T. (Tenagobia) pulchra Hungerford) is described for the first time using scanning electron microscopy. In addition, the eggs of some of these species are described based on color and morphometry. The sculpturing of the chorion and the structure of the micropylar area here in studied using scanning electron microscopy together with the length of the stalk distinguish the eggs of the genera (except Sigara, genus without a uniform pattern on the sculpturing of the chorion) and subgenera (including Aphelosigara and Tropocorixa) of Corixoidea present in Argentina. The above mentioned characters, together with the egg length, proved to be useful for the identification of the Argentinian species. An identification key to the eggs of Argentinian species of Corixoidea based on the material herein studied, and additional data present in the literature, is providedFil: Konopko, Susana Amanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; ArgentinaFil: Mazzucconi, Silvia Ana. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Biodiversidad y Biologia Experimental. Laboratorio de Entomologia; ArgentinaFil: López Ruf, Monica. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentin

    Studies on the chorionic structure of the eggs of <i>Corixoidea</i> (Hemiptera: Heteroptera) with scanning electron microscopy

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    The chorionic structure of the eggs of sixteen species of Corixoidea (Ectemnostega (Ectemnostega) quadrata (Signoret), E. (Ectemnostegella) quechua (Bachmann), Trichocorixa mendozana Jaczewski, Centrocorisa kollari (Fieber), Heterocorixa brasiliensis Hungerford, Sigara (Aphelosigara) tucma Bachmann, S. (Tropocorixa) denseconscripta (Breddin), S. (T.) platensis Bachmann, S. (T.) rubyae (Hungerford), S. (T.) santiagiensis (Hungerford), S. (T.) schadei (Hungerford), S. (T.) yala Bachmann, Tenagobia (Incertagobia) incerta Lundblad, T. (Fuscagobia) fuscata (Stål), T. (Schadeogobia) schadei Lundblad, and T. (Tenagobia) pulchra Hungerford) is described for the first time using scanning electron microscopy. In addition, the eggs of some of these species are described based on color and morphometry. The sculpturing of the chorion and the structure of the micropylar area here in studied using scanning electron microscopy together with the length of the stalk distinguish the eggs of the genera (except Sigara, genus without a uniform pattern on the sculpturing of the chorion) and subgenera (including Aphelosigara and Tropocorixa) of Corixoidea present in Argentina. The above mentioned characters, together with the egg length, proved to be useful for the identification of the Argentinian species. An identification key to the eggs of Argentinian species of Corixoidea based on the material herein studied, and additional data present in the literature, is provided.Facultad de Ciencias Naturales y Muse

    Studies on the chorionic structure of the eggs of <i>Corixoidea</i> (Hemiptera: Heteroptera) with scanning electron microscopy

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    The chorionic structure of the eggs of sixteen species of Corixoidea (Ectemnostega (Ectemnostega) quadrata (Signoret), E. (Ectemnostegella) quechua (Bachmann), Trichocorixa mendozana Jaczewski, Centrocorisa kollari (Fieber), Heterocorixa brasiliensis Hungerford, Sigara (Aphelosigara) tucma Bachmann, S. (Tropocorixa) denseconscripta (Breddin), S. (T.) platensis Bachmann, S. (T.) rubyae (Hungerford), S. (T.) santiagiensis (Hungerford), S. (T.) schadei (Hungerford), S. (T.) yala Bachmann, Tenagobia (Incertagobia) incerta Lundblad, T. (Fuscagobia) fuscata (Stål), T. (Schadeogobia) schadei Lundblad, and T. (Tenagobia) pulchra Hungerford) is described for the first time using scanning electron microscopy. In addition, the eggs of some of these species are described based on color and morphometry. The sculpturing of the chorion and the structure of the micropylar area here in studied using scanning electron microscopy together with the length of the stalk distinguish the eggs of the genera (except Sigara, genus without a uniform pattern on the sculpturing of the chorion) and subgenera (including Aphelosigara and Tropocorixa) of Corixoidea present in Argentina. The above mentioned characters, together with the egg length, proved to be useful for the identification of the Argentinian species. An identification key to the eggs of Argentinian species of Corixoidea based on the material herein studied, and additional data present in the literature, is provided.Facultad de Ciencias Naturales y Muse

    Flexibilidad interna e inseguridad jurídica: disfunciones del régimen legal que desincentivan el uso de esta herramienta

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    Identification and analysis of some of the interpretative problems and applicative dysfunctions presented by the current legal configuration of the internal flexibility figures, which, for generating juridical uncertainty, impede that this type of tools could properly carry out the role entrusted by the legislature, as a great lifeguard of the employment.Identificación y análisis de algunos de los problemas interpretativos y disfunciones aplicativas que presenta la actual configuración legal de las figuras de flexibilidad interna, y que, por generar situaciones de inseguridad jurídica, dificultan que este tipo de herramientas puedan desempeñar adecuadamente el papel encomendado por el legislador, como gran salvavidas del empleo

    Cuestiones prácticas sobre tiempo de trabajo

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    En materia de tiempo de trabajo mucho se ha dicho y escrito, pues se trata de un tema ciertamente amplio y de contenido heterogéneo. En consonancia con ello, el abanico de pronunciamientos y pautas judiciales relevantes al respecto es igualmente extenso y variado. A continuación se expone una reducida selección de sentencias, que no responde a otro objetivo más que ofrecer al lector un brevísimo muestrario de criterios interesantes sobre distintos aspectos de la materia, algunos de ellos no exentos de polémica y que han sido objeto de análisis y debate en la ponencia del Curso de Perfeccionamiento y Actualización Laboral que sobre esta materia ha organizado el CEF

    Development of acute myocardial infarction in a young female patient with essential thrombocythemia treated with anagrelide: a case report

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    Essential thrombocythemia (ET) is a chronic myeloproliferative disorder with a prolonged clinical course. Since this disorder is considered to be at increased risk of thromboembolism, therapy is mainly focused on the decreased risk of thrombohemorrhagic events by use of cytotoxic agents. Anagrelide is a phosphodiesterase III inhibitor which is utilized in the treatment of ET for the reduction of platelets. However, patients treated with anagrelide might experience cardiovascular adverse effects including myocardial infarction (MI), although these events are rare. Herein, we report a case of a 30-year-old female with well controlled ET by anagrelide, who eventually developed an acute non-ST elevation myocardial infarction (MI). There has no found any cardiovascular risk factors in this ET patient, strongly suggesting that anagrelide might be the cause of MI. Therefore, cardiovascular function should be monitored in those patients prescribed with anagrelide
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