Distributive Lattices, Affine Semigroups, and Branching Rules of the Classical Groups

We study algebras encoding stable range branching rules for the pairs of complex classical groups of the same type in the context of toric degenerations of spherical varieties. By lifting affine semigroup algebras constructed from combinatorial data of branching multiplicities, we obtain algebras having highest weight vectors in multiplicity spaces as their standard monomial type bases. In particular, we identify a family of distributive lattices and their associated Hibi algebras which can uniformly describe the stable range branching algebras for all the pairs we consider.Comment: 30 pages, extensively revise

Deliberate masquerades: socialised stigma, HIV/AIDS and altered gay male body image

Three themes are developed in this exegesis. Firstly, it discusses the conceptual base that informs the creative outcomes of this research. This centres on homo-sexuality, disease, illness and the deliberate masquerades that are often under-taken by HIV-positive Australian homosexual males as a response to socialised stigma. Through these masquerades, they enhance the physicality of their bodies so as to conform to Western cultural perceptions of masculine and healthy body ideals and thus avoid stigma that would otherwise be placed on them. This exploration draws upon theories from sociology to discuss these physical enhancements with an emphasis on the period since the onset of HIV/AIDS in the early 1980s. Secondly, it explores the works of visual artists that comment on the HIV/AIDS pandemic prior to the mid 1990s when no effective long-term treatments were available. Thirdly, it investigates HIV/AIDS-based art produced since the mid 1990s, after long-term treatments became available, and discusses how this work contrasts with the earlier works. Also discussed are the parallels and differences between the body of work that is supported by this exegesis and these other contemporary artworks that address HIV/AIDS issues

Dyck tilings, increasing trees, descents, and inversions

Cover-inclusive Dyck tilings are tilings of skew Young diagrams with ribbon tiles shaped like Dyck paths, in which tiles are no larger than the tiles they cover. These tilings arise in the study of certain statistical physics models and also Kazhdan--Lusztig polynomials. We give two bijections between cover-inclusive Dyck tilings and linear extensions of tree posets. The first bijection maps the statistic (area + tiles)/2 to inversions of the linear extension, and the second bijection maps the "discrepancy" between the upper and lower boundary of the tiling to descents of the linear extension.Comment: 24 pages, 9 figure

Prostaglandins and Their Receptors in Insect Biology

We treat the biological significance of prostaglandins (PGs) and their known receptors in insect biology. PGs and related eicosanoids are oxygenated derivatives of arachidonic acid (AA) and two other C20 polyunsaturated fatty acids. PGs are mostly appreciated in the context of biomedicine, but a growing body of literature indicates the biological significance of these compounds extends throughout the animal kingdom, and possibly beyond. The actions of most PGs are mediated by specific receptors. Biomedical research has discovered a great deal of knowledge about PG receptors in mammals, including their structures, pharmacology, molecular biology and cellular locations. Studies of PG receptors in insects lag behind the biomedical background, however, recent results hold the promise of accelerated research in this area. A PG receptor has been identified in a class of lepidopteran hemocytes and experimentally linked to the release of prophenoloxidase. PGs act in several crucial areas of insect biology. In reproduction, a specific PG, PGE2, releases oviposition behavior in most crickets and a few other insect species; PGs also mediate events in egg development in some species, which may represent all insects. PGs play major roles in modulating fluid secretion in Malpighian tubules, rectum and salivary glands, although, again, this has been studied in only a few insect species that may represent the Class. Insect immunity is a very complex defense system. PGs and other eicosanoids mediate a large number of immune reactions to infection and invasion. We conclude that research into PGs and their receptors in insects will lead to important advances in our understanding of insect biology

Willingness to pay for locally produced foods: A customer intercept study of direct market and grocery store shoppers

Increasingly, grocery stores are marketing foods differentiated as locally produced. Freshness and taste are obvious reasons for consumer preference for these goods, but also important may be home-bias. Whatever the motive, there is substantial evidence that some consumers are willing to pay premium prices for food characterized as locally produced. A customer-intercept survey and a choice experiment of food shoppers in direct markets and traditional grocery stores was analyzed using Conjoint methods to evaluate WTP for characteristics related to locally grown fresh strawberries. Our results suggest that consumers are willing to pay more for locally produced berries: Customers intercepted in grocery stores would pay an average of 64 cents more per quart, while those intercepted at direct markets would pay nearly $1.17 more per carton of strawberries that was grown locally rather than berries identified simply as "produced in the U.S." These conclusions provide a solid rationale for the existence of niche market potential for local berry producers.Consumer/Household Economics,

Quality and Quantity Modeling of a Production Line

During the past three decades, the success of the Toyota Production System has spurred research in the area of manufacturing systems engineering. Two research fields, productivity and quality, have been extensively studied and reported separately both in the manufacturing systems research literature and the practitioner, but there is a lack of research in the intersection of these areas. In addition to that, most studies on the relationship among manufacturing system design, quality and productivity are based on anecdotal evidence or qualitative reasoning that lack sound scientific quantitative foundations. This study tries to establish a scientific foundation to investigate how production system design and operation influence productivity and product quality by developing conceptual and computational models and performing experiments. By doing so, this study will show an important part of the way to produce high quality products with minimum cost.Singapore-MIT Alliance (SMA

Significance analysis of lexical bias in microarray data

BACKGROUND: Genes that are determined to be significantly differentially regulated in microarray analyses often appear to have functional commonalities, such as being components of the same biochemical pathway. This results in certain words being under- or overrepresented in the list of genes. Distinguishing between biologically meaningful trends and artifacts of annotation and analysis procedures is of the utmost importance, as only true biological trends are of interest for further experimentation. A number of sophisticated methods for identification of significant lexical trends are currently available, but these methods are generally too cumbersome for practical use by most microarray users. RESULTS: We have developed a tool, LACK, for calculating the statistical significance of apparent lexical bias in microarray datasets. The frequency of a user-specified list of search terms in a list of genes which are differentially regulated is assessed for statistical significance by comparison to randomly generated datasets. The simplicity of the input files and user interface targets the average microarray user who wishes to have a statistical measure of apparent lexical trends in analyzed datasets without the need for bioinformatics skills. The software is available as Perl source or a Windows executable. CONCLUSION: We have used LACK in our laboratory to generate biological hypotheses based on our microarray data. We demonstrate the program's utility using an example in which we confirm significant upregulation of SPI-2 pathogenicity island of Salmonella enterica serovar Typhimurium by the cation chelator dipyridyl