116 research outputs found
Erratum: "Random and block copolymers based on 4-methyl-1-pentene and 1-pentene" (Polymer (2012) 53 (3096-3106))
No full textSexual Dimorphism in Neutral Lipid Metabolism in the Indian-Meal Moth, Plodia Interpunctella (Hubner)
No full textAuthor Institution: Department of Biology, Millersville State College, Millersville, PennsylvaniaOf last larval instar Indian-meal moths, Plodia interpunctella (Hubner), males contain slightly more total neutral lipid per gram live weight than do females. The qualitative composition of the various neutral fractions is similar in both sexes. During the pupal period, the female catabolizes considerably more triglyceride than the male, resulting in a much lower triglyceride content in the newly emerged adult female. There is an almost equal rate of lipid utilization in both sexes during the first three days of adult life
Random and block copolymers based on 4-methyl-1-pentene and 1-pentene
No full textThe zirconium acetamidinate catalyst {Cp*Zr(Me)2[N(Et)C(Me)N(tBu)]} (Cp* = ŋ5-C5Me5) was used to synthesize both random and block copolymers based on 4-methyl-1-pentene (4M1P) and 1-pentene. The polymers have been characterized by NMR spectroscopy, SEC, DSC, high temperature HPLC and CRYSTAF. Unexpectedly, the yields and molecular weights decreased with increasing amounts of 1-pentene. The reason for this behavior is that 1-pentene occasionally undergoes 2,1-misinsertions trapping the catalyst in a dormant state. These 2,1-misinsertions do not seem to occur with the bulky 4M1P (branched α-olefin). Adding a small amount of ethylene reactivates the catalyst. Unlike most semi-crystalline polymers, the density of the crystalline phase of isotactic P4M1P can be lower than of the amorphous phase, when crystallized under very high pressures. To characterize this peculiar behavior of 4M1P-based polymers, various samples have been subjected to Pressure-Volume-Temperature (PVT) measurements. While the P4M1P homopolymers and block copolymers show the expected decrease in specific volume upon crystallization, the 4M1P-rich random copolymers proved not to vary in specific volume under the same conditions
Synthesis and characterization of iPP-sPP stereoblock produced by a binary metallocene system
No full textStereoblock polypropylenes comprising of iPP and sPP segments are synthesized by polymerization of the following binary system of metallocenes: the Cs-symmetric [2,7-t-Bu2(Flu)2Ph2C(Cp)ZrCl2] and the C2-symmetric rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2. Blends of samples made either by each catalyst individually (solution blend) with materials obtained with the mixed catalyst system (reactor blend) are compared. The simultaneous presence of MAO and DEZ, enhancing fast and reversible transfer of the growing chains between the two active centers, leads to the formation of a stereoblock microstructure. In this case, low molecular weight polymers are obtained. The junction between the blocks is qualitatively observed in 13C NMR. When made in toluene, the stereoblock material consists of a majority of syndiotactic sequences, whereas the ratio is more equilibrated when the polymerization was conducted in the more polar chlorobenzene. This is confirmed by the results obtained with 13C NMR, CRYSTAF, HT HPLC, DSC, SSA, WAXD, and optical microscopy
Eco-Wisdom in Mythotype
No full textПредставлена версия экологической мудрости в составе мифотипа. Автор разделяет взгляды А. Ф. Лосева, И. Т. Фролова, К. Хюбнера на особое место мифа в культуре человечества.Presented the version of ecological wisdom as part of the mythotype. The author shares the views of A. F. Loseva, I. T. Frolova, K. Hubner on the special place of myth in the culture of mankind
Down to a r/science: Integrating Computational Approaches to the Study of Credibility on Reddit
No full textDigital trace data enable researchers to study communication processes at a scale previously impossible. We combine social network analysis and automated content analysis to examine source and message factors’ impact on credibility ratings. We found that the expertise of the author, the network position that the author occupies, and characteristics of the content the author creates have a significant impact on how that content will be assessed by others. By observationally examining a large-scale online community, we provide a real-world test of how source and message characteristics are evaluated by message consumers. Our results show that it is important to think of online communication as occurring interactively between networks of individuals, and that the network positions people inhabit may inform their behavior
Ecological Studies of Velvetbean Caterpillar, Anticarsia Gemmatalis Hubner, Pupae in Louisiana Soybean Fields.
No full textThe microhabitat distribution of velvetbean caterpillar (VBC), Anticarsia gemmatalis Hubner (Lepidoptera: Noctuidae) was studied in soybean field cages and fields during 1985, 1986 and 1987. Larval density did not affect pupal horizontal distribution patterns related to direction and distance from the plant row. Pupae were found equally on both sides of soybean plant rows in a cage study. Pupae were found on and below the soil surface, but not on the plant. In 51 cm row spacing, both equal number and similar dispersion pattern of pupae were found on either side of the plant row. In 91 cm row spacing, pupal densities were slightly biased to the north side (4:6) of the plant rows in 1986 and this trend was extreme (2:8) in 1987 when plant canopy was barely closed. The degree of plant canopy closure appeared to influence pupal horizontal distribution. In 91 cm row spacing, pupal densities varied inversely with distance from the row. Taylor\u27s power law analyses indicated that VBC pupal spatial dispersion patterns were random in both 51 and 91 cm row spacings for a sample unit (90 by 90 cm) and a subsample unit (90 by 15 cm parallel to the plant row and 15 by 90 cm across the plant row in 51 and 91 cm row spacings, respectively). Significant linear relationships between larval and pupal densities were found for all three larval size classes (small, 1st and 2nd instars (0-12.5 mm long); medium, 3rd and 4th instars (12.5-25 mm long); large, (25 mm long)) in 51 and 91 cm row spacing fields in 1986 but only for medium larvae in 1987. Simple linear regression equations were developed to predict pupal density from larval density. The survivorship and predation of VBC pupae were studied in 1986 and 1987. Seven species of insects including ground beetles, tiger beetles, earwigs and the red imported fire ant, Solenopsis invicta Buren, were identified in laboratory feeding trials as VBC pupal predators. Predation was the principal mortality factor, accounting for 37.5 to 95.2% mortality in plots with fire ants. (Abstract shortened with permission of author.)
Agência na sociologia: os diferentes usos do conceito de agência em Weber, Giddens e Latour
No full textThe present article seeks to analyze the notion of agency in sociology from Weber, Giddens and Latour. Although the notion or concept is the same, it presents some significant differences. Thus, we can see what are the interchangeable elements and their specificities in each author. The notion of agency has been widely used, often losing its real meaning from the authors who are used. The article is divided into three parts. The first introductory, introduces the notion of agency in Weber to demonstrate the question of subjectivity in the sociological view. The second part deals with the question of the agency in Giddens, demonstrating a greater complexity of the notion where the notion of competent actor gains notoriety. In the third and final part, the notion of agency in Latour is approached, where the agency is observed as a construction of socio-technical networks from nonhumans. The results point to a heterogeneity in the notions of agency in sociology, and the notion of agency in Giddens is much more sophisticated in understanding human action, while the association of nonhumans in Latour allows us to observe other relationships in larger networks.O presente artigo procura analisar a noção de agência na sociologia a partir de Weber, Giddens e Latour. Apesar da noção ou do conceito ser o mesmo, ele apresenta algumas diferenças significativas. Assim, podemos observar quais são os elementos intercambiáveis e suas especificidades em cada autor. A noção de agência tem sido utilizada de maneira ampla, muitas vezes perdendo o seu real significado a partir dos autores que são utilizados. O artigo está dividido em três partes. A primeira introdutória, apresenta o conceito de agência em Weber para demonstrar a questão da subjetividade na ótica sociológica. Já a segunda parte aborda a questão da agência em Giddens, demonstrando uma maior complexidade do conceito aonde a noção de ator competente ganha notoriedade. Na terceira e última parte é abordada o conceito de agência em Latour, aonde a agência é observada como uma construção de redes sociotécnicas a partir dos não-humanos. Os resultados apontam para uma heterogeneidade dos conceitos de agência na sociologia, sendo muito mais sofisticado o conceito de agência em Giddens para compreender a ação dos humanos, enquanto que a associação de não-humanos em Latour permite observar outras relações em redes mais amplas
A REPRESENTAÇÃO EM HOBBES-ROUSSEAU: UM HÍBRIDO POLÍTICO CONTIDO NOS PARÂMETROS DA DEMOCRACIA
No full textThis article seeks to analyse a possible interface in the theory of Hobbes na Rousseau, from the perspective of the democratic of representaitiness. It is a review of a theorentician, whose work entitled “Science in Democracy. Expertise, Institutions, and Representations” by Mark Brown, allowed to connect these contractualists, in order to think democratic possibilities in the parameters of the two contractualists. Some of the authors’ consonances and dissonances are also presented, as there are elements that converge and others that diverge, related to the state of nature, the theory of elites and democracy. The methodology used consists of bibliographic research, the comparative method, the role of facts in relation to theory and the fact reformulating and rejecting theories. Some of key concepts of the authors’ political theory ate analyzed, such as Author and Actor in Hobbes and Active Sovereign and Passive Subject coexisting in Rousseau, in order to demonstrate a hybrid in the representation model that does not distance the thinkinh of these two authors as is generally observed, but which brings them closer to key elements of Civil Liberty contained in th Social Contract. As a partial result, we infer a hybridity of the Hobbes-Rousseau representativeness, which is as Actor-Ficional-Sovereign as Atcive, and Author-Subject-Natural as subject. Allowing to observed both the bloblem contained in the Social Contract in Rousseau about the guarantee of freedon, as well as removing individuals from the State of war in Hobbes, finding legitimacy in this process.El presente artículo busca analizar una posible interfaz en la teoría de Hobbes y Rousseau, en la perspectiva de la teoría democrática de representatividad. Se trata de una revisión teórica, cuya obra titulada "Science in Democracy. Expertise, Institutions, and Representations" de Mark Brown, permitió conectar estos contractualistas, a fin de pensar posibilidades democráticas en los parámetros de los dos contractualistas. También se presentan algunas de las consonancias y disonancias de los autores, pues existen elementos que convergen y otros que divergen, relativos al estado de naturaleza, la teoría de las élites y la democracia. La metodología utilizada consiste en la investigación bibliográfica, el método comparativo, el papel de los hechos en relación con la teoría y el hecho reformulando y rechazando teorías. Se analizan algunos de los conceptos claves de la teoría política de los autores, como Autor y Actor en Hobbes y Soberano Activo y Súbdito Pasivo coexistiendo en Rousseau, con el fin de demostrar un híbrido en el modelo de representación que no aleja el pensamiento de estos dos autores como se observa generalmente, sino que los acerca a elementos clave de la Libertad Civil contenida en el Contrato Social. Como resultado parcial inferimos un hibridismo de la representatividad Hobbes-Rousseau que es un Actor-Ficticio-Soberano como Activo, y, Autor-Súbdito-Natural como súbdito. permitiendo observar tanto el problema contenido en el Contrato Social en Rousseau sobre la garantía de la libertad, así como retirar a los individuos del Estado de guerra en Hobbes, encontrando una legitimidad en este proceso.O presente artigo procura analisar uma possível interface na teoria de Hobbes e Rousseau, na perspectiva da teoria democrática de representatividade. Trata-se de uma revisão bibliográfica, cuja obra intitulada Science in Democracy. Expertise, Institutions, and Representations, de Mark Brown (2009) permitiu conectar estes contratualistas, a fim de pensar possibilidades democráticas nos parâmetros dos dois contratualistas. Também são apresentadas algumas das consonâncias e dissonâncias dos autores, pois existem elementos que convergem e outros que divergem, relativos ao estado de natureza, à teoria das elites e à democracia. A metodologia utilizada consiste na pesquisa bibliográfica, no método comparativo, no papel dos fatos em relação à teoria e no fato reformulando e rejeitandoteorias. São analisados alguns dos conceitos-chave da teoria política dos autores, como Autor e Ator em Hobbes e Soberano Ativo e Súdito Passivo coexistindo em Rousseau, a fim de demonstrar um híbrido no modelo de representação que não afasta o pensamento destes dois autores conforme geralmente é observado, mas que os aproxima a elementos chave da Liberdade Civil contida no Contrato Social. Como resultado parcial inferimos um hibridismo da representatividade Hobbes-Rousseau que é um Ator-Fictício-Soberano enquanto ativo e, Autor-Súdito-Natural enquanto súdito, permitindo observar tanto o problema contido no Contrato Social em Rousseau sobre a garantia da liberdade, bem como retirar os indivíduos do Estado de guerra em Hobbes, encontrando uma legitimidade neste processo.
DOI: https://doi.org/10.5935/2358-3541.2025142003-pt
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