10,070 research outputs found
The topological Singer construction
We study the continuous (co-)homology of towers of spectra, with emphasis on
a tower with homotopy inverse limit the Tate construction X^{tG} on a
G-spectrum X. When G=C_p is cyclic of prime order and X=B^p is the p-th smash
power of a bounded below spectrum B with H_*(B) of finite type, we prove that
(B^p)^{tC_p} is a topological model for the Singer construction R_+(H^*(B)) on
H^*(B). There is a map epsilon_B : B --> (B^p)^{tC_p} inducing the
Ext_A-equivalence epsilon : R_+(H^*(B)) --> H^*(B). Hence epsilon_B and the
canonical map Gamma : (B^p)^{C_p} --> (B^p)^{hC_p} are p-adic equivalences
The Segal conjecture for topological Hochschild homology of complex cobordism
We study the C_p-equivariant Tate construction on the topological Hochschild
homology THH(B) of a symmetric ring spectrum B by relating it to a topological
version R_+(B) of the Singer construction, extended by a natural circle action.
This enables us to prove that the fixed and homotopy fixed point spectra of
THH(B) are p-adically equivalent for B = MU and BP. This generalizes the
classical C_p-equivariant Segal conjecture, which corresponds to the case B =
S.Comment: Accepted for publication by the Journal of Topolog
Moth Species New to Michigan
This is a compilation of moth species previously unrecorded from Michigan. Moore\u27s (1955) publication has been critically examined necessitating some specific changes. All questionable material has been determined by present day specialists in their particular fields. The McDunnough (1938) checklist is followed in the arrangement of the new data together with most of the recent changes in nomenclature as presented by Forbes (1948, 1954, 1960), Hardwick (1970), Hodges (1971), and Covell (1970, 1971). With the advent of more sophisticated collecting equipment and the easier access to Michigan\u27s Upper Peninsula a total of 154 species has been added. Many institutional and private collections have been examined including the large collection at Michigan State University which was not considered in the Moore publication
Comparison of extraction methods for analysis of flavonoids in onions
Onions are known to contain high levels of flavonoids and a comparison of the efficiency, reproducibility and detection limits of various extraction methods has been made in order to develop fast and reliable analytical methods for analysis of flavonoids in onions.
Conventional and classical methods are time- and solvent-consuming and the presence of light and oxygen during sample preparation facilitate degradation reactions. Thus, classical methods were compared with microwave (irradiation) extraction, ultrasonic liquid extraction and accelerated solvent extraction
Bioactive metabolites in crops, diets and human samples
The objective of the PhD-project is to characterize bioactive metabolites, such as polyphenols, in selected crops and investigate the influence of different organic farming systems on the ability of crops to synthesize bioactive compounds with health promoting effects. The study includes two organic and one conventional farming system and is part of the OrgTrace project (content, bioavailability and health effects of trace elements and bioactive components in organic agricultural systems), where harvest takes place in autumn 2007 and 2008
Further Generalisations of Twisted Gabidulin Codes
We present a new family of maximum rank distance (MRD) codes. The new class
contains codes that are neither equivalent to a generalised Gabidulin nor to a
twisted Gabidulin code, the only two known general constructions of linear MRD
codes.Comment: 10 pages, accepted at the International Workshop on Coding and
Cryptography (WCC) 201
The Kuznets Curve and the Inequality Process
Four economists, Mauro Gallegati, Steven Keen, Thomas Lux, and Paul Ormerod, published a paper after the 2005 Econophysics Colloquium criticizing conservative particle systems as models of income and wealth distribution. Their critique made science news: coverage in a feature article in Nature. A particle system model of income distribution is a hypothesized universal statistical law of income distribution. Gallegati et al. (2006) claim that the Kuznets Curve shows that a universal statistical law of income distribution is unlikely and that a conservative particle system is inadequate to account for income distribution dynamics. The Kuznets Curve is the graph of income inequality (ordinate variable) against the movement of workers from rural subsistence agriculture into more modern sectors of the economy (abscissa). The Gini concentration ratio is the preferred measure of income inequality in economics. The Kuznets Curve has an initial uptick from the Gini concentration ratio of the earned income of a poorly educated agrarian labor force. Then the curve falls in near linear fashion toward the Gini concentration ratio of the earned incomes of a modern, educated labor force as the modern labor force grows. The Kuznets Curve is concave down and skewed to the right. This paper shows that the iconic Kuznets Curve can be derived from the Inequality Process (IP), a conservative particle system, presenting a counter-example to Gallegati et al.âs claim. The IP reproduces the Kuznets Curve as the Gini ratio of a mixture of two IP stationary distributions, one characteristic of the wage income distribution of poorly educated workers in rural areas, the other of workers with an education adequate for industrial work, as the mixing weight of the latter increases and that of the former decreases. The greater purchasing power of money in rural areas is taken into account.conservative particle system; gamma probability density function; Gini concentration ratio; income distribution; Inequality Process; Kuznets Curve; purchasing power
Quantification of root fungi using signature fatty acids
Both deleterious (pathogenic) and beneficial (mycorrhizal) fungi inhabit plant roots with strong impact on plant growth and health. Various methods have been used to quantify these fungi, such as indirect measurements of plant parameters, disease index, staining techniques and serological/genetic/biochemical markers. The objective of this work is to evaluate the possibility of using signature fatty acids to quantify root-inhabiting fungi in planta and in soil. Different fatty acid-based methods can be used to quantify fungi. Phospholid fatty acids (PLFA) can be used for biomass estimation and neutral lipid fatty acids (NLFA) for estimation of fungal energy reserves and the NLFA/PLFA ratio can give information on the physiological status of the fungus. It is quite laborious to make PLFA and NLFA analyses; so whole cell fatty acid (WCFA) analyses, which are much faster, can be used as a faster alternative to give information of root infection intensity.
Signature fatty acids have been used to quantify arbuscular mycorrhizal fungi (16:1Ď5) and the pea root pathogen Aphanomyces euteiches (14:1Ď9). Recently, we have further used arachadonic acid (20:4) to estimate root infection intensity of the plasmodiophorids Plasmodiophora brassica, causing club root in cabbage and Spongospora subterranea, the vector of mop top potato virus. Specificity of the various signature fatty acids of root-inhabiting fungi are discussed in relation to quantifying these fungi in both controlled greenhouse pot experiments and in the field. Furthermore, the possibility of using signature fatty acids to estimate soil inoculum potential of root-inhabiting fungi are discussed
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