986 resultados para 202-1240
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This dataset contains the collection of available published paired Uk'37 and Tex86 records spanning multi-millennial to multi-million year time scales, as well as a collection of Mg/Ca-derived temperatures measured in parallel on surface and subsurface dwelling foraminifera, both used in the analyses of Ho and Laepple, Nature Geoscience 2016. As the signal-to-noise ratios of proxy-derived Holocene temperatures are relatively low, we selected records that contain at least the last deglaciation (oldest sample >18kyr BP).
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In this study we review a global set of alkenone- and foraminiferal Mg/Ca-derived sea surface temperatures (SST) records from the Holocene and compare them with a suite of published Eemian SST records based on the same approach. For the Holocene, the alkenone SST records belong to the actualized GHOST database (Kim, J.-H., Schneider R.R., 2004). The actualized GHOST database not only confirms the SST changes previously described but also documents the Holocene temperature evolution in new oceanic regions such as the Northwestern Atlantic, the eastern equatorial Pacific, and the Southern Ocean. A comparison of Holocene SST records stemming from the two commonly applied paleothermometry methods reveals contrasting - sometimes divergent - SST evolution, particularly at low latitudes where SST records are abundant enough to infer systematic discrepancies at a regional scale. Opposite SST trends at particular locations could be explained by out-of-phase trends in seasonal insolation during the Holocene. This hypothesis assumes that a strong contrast in the ecological responses of coccolithophores and planktonic foraminifera to winter and summer oceanographic conditions is the ultimate reason for seasonal differences in the origin of the temperature signal provided by these organisms. As a simple test for this hypothesis, Eemian SST records are considered because the Holocene and Eemian time periods experienced comparable changes in orbital configurations, but had a higher magnitude in insolation variance during the Eemian. For several regions, SST changes during both interglacials were of a similar sign, but with higher magnitudes during the Eemian as compared to the Holocene. This observation suggests that the ecological mechanism shaping SST trends during the Holocene was comparable during the penultimate interglacial period. Although this "ecology hypothesis" fails to explain all of the available results, we argue that any other mechanism would fail to satisfactorily explain the observed SST discrepancies among proxies.
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Abundant hydroclimatic evidence from western Amazonia and the adjacent Andes documents wet conditions during Heinrich Stadial 1 (HS1, 18-15 ka), a cold period in the high latitudes of the North Atlantic. This precipitation anomaly was attributed to a strengthening of the South American summer monsoon due to a change in the Atlantic interhemispheric sea surface temperature (SST) gradient. However, the physical viability of this mechanism has never been rigorously tested. We address this issue by combining a thorough compilation of tropical South American paleorecords and a set of atmosphere model sensitivity experiments. Our results show that the Atlantic SST variations alone, although leading to dry conditions in northern South America and wet conditions in northeastern Brazil, cannot produce increased precipitation over western Amazonia and the adjacent Andes during HS1. Instead, an eastern equatorial Pacific SST increase (i.e., 0.5-1.5 °C), in response to the slowdown of the Atlantic Meridional Overturning Circulation during HS1, is crucial to generate the wet conditions in these regions. The mechanism works via anomalous low sea level pressure over the eastern equatorial Pacific, which promotes a regional easterly low-level wind anomaly and moisture recycling from central Amazonia towards the Andes.
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The leaf-tying moth Hypocosmia pyrochroma Jones (Lepidoptera: Pyralidae), a native of sub tropical South America, has been introduced as a biological control agent for cat’s claw creeper, Dolichandra unguis-cati (L.) Lohman (Bignoniaceae), in Australia and South Africa. So far there has been no evidence of its field establishment in either country. A narrow temperature tolerance is a potential limiting factor for the establishment of weed biological control insects in novel habitats. In this study, we evaluated the effect of seven constant temperatures (12–40 °C) on the survival and development of H. pyrochroma in temperature-controlled cabinets. Temperatures between 20 and 30 °C were the most favorable for adult survival, oviposition, egg hatching, and larval and pupal development. Adult survival (12–40 °C) and egg development (15–35 °C) showed tolerance for wider temperature ranges than oviposition, and larval and pupal development, which were all negatively affected by both high (>30 °C) and low (<20 °C) temperatures. The degree-day (DD) requirement to complete a generation was estimated as 877 above a threshold temperature of 12 °C. Based on DD requirements and an obligatory winter diapause of pupae from mid-autumn to mid-spring, the potential number of generations (egg to adult) the leaf-tying moth can complete in a year in Australia or South Africa range from one to three. A climate-matching model predicted that the inland regions of both Australia and South Africa are less favorable for H. pyrochroma than the coastal areas. The study suggested that H. pyrochroma is more likely to establish in the coastal areas of Australia where most of the cat’s claw creeper infestations occur, than in South Africa where most of the cat’s claw creeper infestations are inland.
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The leaf-tying moth Hypocosmia pyrochroma Jones (Lepidoptera: Pyralidae), a native of sub tropical South America, has been introduced as a biological control agent for cat’s claw creeper, Dolichandra unguis-cati (L.) Lohman (Bignoniaceae), in Australia and South Africa. So far there has been no evidence of its field establishment in either country. A narrow temperature tolerance is a potential limiting factor for the establishment of weed biological control insects in novel habitats. In this study, we evaluated the effect of seven constant temperatures (12–40 °C) on the survival and development of H. pyrochroma in temperature-controlled cabinets. Temperatures between 20 and 30 °C were the most favorable for adult survival, oviposition, egg hatching, and larval and pupal development. Adult survival (12–40 °C) and egg development (15–35 °C) showed tolerance for wider temperature ranges than oviposition, and larval and pupal development, which were all negatively affected by both high (>30 °C) and low (<20 °C) temperatures. The degree-day (DD) requirement to complete a generation was estimated as 877 above a threshold temperature of 12 °C. Based on DD requirements and an obligatory winter diapause of pupae from mid-autumn to mid-spring, the potential number of generations (egg to adult) the leaf-tying moth can complete in a year in Australia or South Africa range from one to three. A climate-matching model predicted that the inland regions of both Australia and South Africa are less favorable for H. pyrochroma than the coastal areas. The study suggested that H. pyrochroma is more likely to establish in the coastal areas of Australia where most of the cat’s claw creeper infestations occur, than in South Africa where most of the cat’s claw creeper infestations are inland.
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This dissertation examines the concept of beatific enjoyment (fruitio beatifica) in scholastic theology and philosophy in the thirteenth and early fourteenth century. The aim of the study is to explain what is enjoyment and to show why scholastic thinkers were interested in discussing it. The dissertation consists of five chapters. The first chapter deals with Aurelius Augustine's distinction between enjoyment and use and the place of enjoyment in the framework of Augustine's view of the passions and the human will. The first chapter also focuses upon the importance of Peter Lombard's Sentences for the transmission of Augustine's treatment of enjoyment in scholastic thought as well as upon Lombard's understanding of enjoyment. The second chapter treats thirteenth-century conceptions of the object and psychology of enjoyment. Material for this chapter is provided by the writings - mostly Sentences commentaries - of Alexander of Hales, Albert the Great, Bonaventure, Thomas Aquinas, Peter of Tarentaise, Robert Kilwardby, William de la Mare, Giles of Rome, and Richard of Middleton. The third chapter inspects early fourteenth-century views of the object and psychology of enjoyment. The fourth chapter focuses upon discussions of the enjoyment of the Holy Trinity. The fifth chapter discusses the contingency of beatific enjoyment. The main writers studied in the third, fourth and fifth chapters are John Duns Scotus, Peter Aureoli, Durandus of Saint Pourçain, William of Ockham, Walter Chatton, Robert Holcot, and Adam Wodeham. Historians of medieval intellectual history have emphasized the significance of the concept of beatific enjoyment for understanding the character and aims of scholastic theology and philosophy. The concept of beatific enjoyment was developed by Augustine on the basis of the insight that only God can satisfy our heart's desire. The possibility of satisfying this desire requires a right ordering of the human mind and a detachment of the will from the relative goals of earthly existence. Augustine placed this insight at the very foundation of the notion of Christian learning and education in his treatise On Christian Doctrine. Following Augustine, the twelfth-century scholastic theologian Peter Lombard made the concept of enjoyment the first topic in his plan of systematic theology. The official inclusion of Lombard's Sentences in the curriculum of theological studies in the early universities stimulated vigorous discussions of enjoyment. Enjoyment was understood as a volition and was analyzed in relation to cognition and other psychic features such as rest and pleasure. This study shows that early fourteenth-century authors deepened the analysis of enjoyment by concentrating upon the relationship between enjoyment and mental pleasure, the relationship between cognition and volition, and the relationship between the will and the beatific object (i.e., the Holy Trinity). The study also demonstrates the way in which the idea of enjoyment was affected by changes in the method of theological analysis - the application of Aristotelian logic in a Trinitarian context and the shift from virtue ethics to normative ethics.
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Deputados progressistas da Assembleia Nacional Constituinte (ANC) se unem para apresentar emendas. Divididos em vinte e nove grupos, avaliam o substitutivo do Relator Bernardo Cabral (PMDB-AM). O Deputado Plínio Arruda Sampaio (PT-SP) considera que, se formarem uma base sólida, os progressistas terão melhores condições de negociar com os outros grupos. O Deputado Vivaldo Barbosa (PDT-RJ) informa dos pontos de consenso do grupo. Na Sessão para discussão de emendas populares, o debate dos direitos dos trabalhadores teve com ponto polêmico a estabilidade no emprego. Luiz Carlos Mandelli, representando o movimento pela livre iniciativa, critica a emenda que dá estabilidade ao empregado. O Deputado Mário Lima (PMDB-BA) afirma que os empresários estão cometendo um equívoco muito grande, pois o trabalhador quando tem estabilidade no emprego produz mais e melhor. Outra emenda popular propõe que o serviço de transporte coletivo seja estatizado. Ela foi defendida por João Bosco, Presidente da CONAN (Confederação Nacional das Associações de Moradores), que considera que cabe às prefeituras a gestão, planejamento e operacionalização do transporte coletivo. A CONAN ainda reivindica 25% do orçamento nacional para a construção de casas populares. Dalva Stella Medeiros (Vice-presidente da CONAN) defende que o poder público deve assumir o direito à moradia popular para todos os cidadãos. Na sessão O Povo Pergunta, cidadã gostaria de saber se os constituintes estão pensando em fazer uma Constituição voltada para pequenos interesses ou para os interesses da grande maioria da população. O Deputado Assis Canuto (PFL-RO) responde que há uma tendência de particularizar a Constituição brasileira, mas cabe a sociedade e aos constituintes fazerem uma Constituição para todos os brasileiros.
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Recent research has shown that the biomass of bacteria in lakes and other water-bodies can attain significant values. The huge production of bacteria is brought about by their great rate of reproduction. In a series of cases their biomass exceeds the biomass of phytoplankton. Therefore in a study of the biological productivity of water bodies it is necessary to calculate the biomass and production not only of the phyto- and zooplankton, but also of bacteria.The authors uses different methods and formulae to to compare the time of one generation of the bacteria.
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The original method, proposed by Yentsch (1957), of determination of chlorophyll directly in the cells, attracts attention by its simplicity. In order to measure the content of chlorophyll by this method, a determined volume of suspension of algae is filtered through a membrane filter. The latter is dried a little, clarified by immersion oil, clamped between two glasses, and spectrophotometrized. Extinction is read off at , wavelengths equal to 670 millimicrons (around the maximum absorption of chlorophyll a in the cell) and 750 millimicrons (correction for non- specific absorption and dispersion of light by particles of the preparation). The method of Yentsch was employed by the authors for determination of chlorophyll-a in samples of phytoplankton. They conclude that in spite of the simplicity and convenience of determination the method must be applied sufficiently carefully. It is more suitable for analysis of cultures of algae, where, non-specific absorption of light is insignificant.
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Eudiaptomus vulgaris Schmeil is the most abundant copepod in Lake Maggiore and forms also, in respect to other entomostraca, the most important element, through its average biomass and because it is fairly numerous throughout the year. Plankton samples collected in a systematic and quantitative way, gave the opportunity to study some aspects of the dynamics of the population of this copepod, in safety in view of the uncertainty which in this kind of study can ensue when samples are taken only at a single station - in consequence of the changes in size of population between different water masses. The results of the biometrical observations are of the population of Eudiaptomus vulgaris is presented.
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A label-free and highly sensitive impedimetric aptasensor based on a polyamidoamine dendrimer modified gold electrode was developed for the determination of thrombin. Amino-terminated polyamidoamine dendrimer was firstly covalently attached to the cysteine functionalized gold electrode through glutaraldehyde coupling. Subsequently, the dendrimer was activated with glutaraldehyde, and amino-modified thrombin aptamer probe was immobilized onto the activated dendrimer monolayer film. The layer-by-layer assembly process was traced by surface plasmon resonance and electrochemical impedance spectroscopy.
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11 fotografías, diez a color.
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This presentation is about a song, ”Catford Riddim” by the A-Team, a group of grime artists from South London, specifically about how it came to be played, perhaps a bit too loudly, in the back of the 202 bus one January morning on a teenager’s mobile phone. As an illustration of how social networks and technological networks converge, the ”Catford Riddim,” insisting on the music’s own provenance from the SE6 postcode, shows the formation of a local ethnoscape in the global networks of peer-to-peer file sharing and online DIY distribution sites such as MySpace. Contesting the narrative of online social networks as routes to fame, I suggest that on the contrary they illustrate the emergence of local, even insular, ”scenes” of musicians, events and audiences.