203,508 research outputs found
Airborne organophosphate pesticides drift in Mediterranean climate: The importance of secondary drift
No full textPesticide application is a short-term air-pollution episode with near and far field effects due to atmospheric drift. In order to better evaluate resulting air concentrations in nearby communities following pesticide application, measurements of airborne pesticides were conducted at ~70 m from field edge. This was done following three different application events of the organophosphate pesticide Chlorpyrifos in a persimmon orchard. Complementary information on larger spatial scale was obtained using CALPUFF modeling in which application and meteorological data was used to better evaluate dispersion patterns.Measurements indicated high airborne concentrations during application hours (few μg m-3 for 8 h average), which dropped to tens of ng m-3 in the following days. Measured atmospheric concentrations show that secondary drift (i.e., post-application drift) involves significant loads of pesticides and hence should not be ignored in exposure considerations. Furthermore, CALPUFF modeling revealed the complex dispersion pattern when weak winds prevailed, and showed that during the 24 h after application air concentrations reached levels above the hourly Texas effect screening level (0.1 μg m-3). Interestingly, weak winds on the night after application resulted in a secondary peak in measured and modeled air concentrations.Long exposure time (when secondary drift is considered) and concentrations measured following such common air-assisted orchard application, suggest pesticide drift may have health repercussions that are currently unknown, and emphasize the need for further epidemiological studies
MSU Recent Art Acquisitions : Segal, Dali and Others, January 21-February 20, 2016
No full textThis exhibition catalogue is published in conjunction with the exhibition, MSU Recent Art Acquisitions : Segal, Dali and othershttps://digitalcommons.montclair.edu/all_books/1153/thumbnail.jp
Higher Segal spaces
No full textThis monograph initiates a theory of new categorical structures that generalize the simplicial Segal property to higher dimensions. The authors introduce the notion of a d-Segal space, which is a simplicial space satisfying locality conditions related to triangulations of d-dimensional cyclic polytopes. Focus here is on the 2-dimensional case. Many important constructions are shown to exhibit the 2-Segal property, including Waldhausen’s S-construction, Hecke-Waldhausen constructions, and configuration spaces of flags. The relevance of 2-Segal spaces in the study of Hall and Hecke algebras is discussed. Higher Segal Spaces marks the beginning of a program to systematically study d-Segal spaces in all dimensions d. The elementary formulation of 2-Segal spaces in the opening chapters is accessible to readers with a basic background in homotopy theory. A chapter on Bousfield localizations provides a transition to the general theory, formulated in terms of combinatorial model categories, that features in the main part of the book. Numerous examples throughout assist readers entering this exciting field to move toward active research; established researchers in the area will appreciate this work as a reference.Front Matter Pages i-xv Preliminaries Tobias Dyckerhoff, Mikhail Kapranov Pages 1-8 Topological 1-Segal and 2-Segal Spaces Tobias Dyckerhoff, Mikhail Kapranov Pages 9-30 Discrete 2-Segal Spaces Tobias Dyckerhoff, Mikhail Kapranov Pages 31-70 Model Categories and Bousfield Localization Tobias Dyckerhoff, Mikhail Kapranov Pages 71-84 The 1-Segal and 2-Segal Model Structures Tobias Dyckerhoff, Mikhail Kapranov Pages 85-94 The Path Space Criterion for 2-Segal Spaces Tobias Dyckerhoff, Mikhail Kapranov Pages 95-106 2-Segal Spaces from Higher Categories Tobias Dyckerhoff, Mikhail Kapranov Pages 107-124 Hall Algebras Associated to 2-Segal Spaces Tobias Dyckerhoff, Mikhail Kapranov Pages 125-151 Hall (∞, 2)-Categories Tobias Dyckerhoff, Mikhail Kapranov Pages 153-167 An (∞, 2)-Categorical Theory of Spans Tobias Dyckerhoff, Mikhail Kapranov Pages 169-199 2-Segal Spaces as Monads in Bispans Tobias Dyckerhoff, Mikhail Kapranov Pages 201-208 Back Matter Pages 209-21
Higher Segal spaces I
No full textThis is the first paper in a series on new higher categorical structures called higher Segal spaces. For every d > 0, we introduce the notion of a d-Segal space which is a simplicial space satisfying locality conditions related to triangulations of cyclic polytopes of dimension d. In the case d=1, we recover Rezk's theory of Segal spaces. The present paper focuses on 2-Segal spaces. The starting point of the theory is the observation that Hall algebras, as previously studied, are only the shadow of a much richer structure governed by a system of higher coherences captured in the datum of a 2-Segal space. This 2-Segal space is given by Waldhausen's S-construction, a simplicial space familiar in algebraic K-theory. Other examples of 2-Segal spaces arise naturally in classical topics such as Hecke algebras, cyclic bar constructions, configuration spaces of flags, solutions of the pentagon equation, and mapping class groups
The association of IS1133 with an aminoglycoside resistance gene, aacC2a, in Acinetobacter baumannii isolates
No full textIncludes bibliographical references (leaves 93-103)
Modeling Supreme Court Strategic Decision Making: Congressional Constraint
No full textThis paper addresses the contradictory results obtained in Segal (1997) and Spiller and Gely (1992) concerning the impact of institutional constraints on the US Supreme Court decisionmaking. by adapting the Spiller and Gely model to the data set utilized by Segal. The major findings are as follows: first, by adapting the Spiller and Gely (1992) maximum likelihood model to the Segal (1997) dataset, we find support for the hypothesis that the Court adjusts its decisions to Presidential and congressional preferences. Second, data from 1947-92 indicate that the average probability of the Court being constrained has been approximately one third. Third, we show that the results obtained in Segal (1997) are the product of biases introduced by a misspecified econometric model. Finally, the estimation highlights the usefulness of Krehbiel’s model of legislative decision-making.
Art Segal
No full textA portrait of Art Segal. The original description of the photo negative strip included Dorothy May Wilson , Art Seagal , H. M. Ackerley , and Wayne Barr .https://scholarworks.uni.edu/uniphotos/3848/thumbnail.jp
Shape classification of (projective m-space)-like continua
No full textAbstractThe Mardešić-Segal approach to shape classification of M-like continua (M a compact metric ANR) is reformulated in an algebraic setting. A functor Sh from the category of semigroups to the category of sets is defined which, when applied to [M, M], the semigroup of homotopy classes maps of M into itself, yields the shape classification of M-like continua. The shape classification of all (real projective m-space)-like continua is completely solved
El teorema de completación de Atiyah-Segal
No full textThis dissertation is about Atiyah-Segal's theorem of completion. The first part studies the basic concepts of vector bundles and representation theory. Then we study K-theory and equivariant K-theory. Lastly, we construct and prove Atiyah-Segal's theorem with emphasis on inverse systems.Esta tesis es sobre el teorema de completación de Atiyah-Segal. La primera parte estudia los conceptos básicos de fibrados vectoriales y teoría de representación. Luego, se estudia la K-teoría y la K-teoría equivariante. Finalmente, se construye y prueba el teorema de Atiyah-Segal, con énfasis en sistemas inversos.Línea de Investigación: Topología AlgebraicaMaestrí
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