The solution of the delta function model for helium like ions

Fredholm solution of delta function model for two electron helium like ion

Degree of the generalized Pl\"ucker embedding of a Quot scheme and Quantum cohomology

We compute the degree of the generalized Pl\"ucker embedding $\kappa$ of a Quot scheme $X$ over \PP^1. The space $X$ can also be considered as a compactification of the space of algebraic maps of a fixed degree from \PP^1 to the Grassmanian $\rm{Grass}(m,n)$. Then the degree of the embedded variety $\kappa (X)$ can be interpreted as an intersection product of pullbacks of cohomology classes from $\rm{Grass}(m,n)$ through the map $\psi$ that evaluates a map from \PP^1 at a point x\in \PP^1. We show that our formula for the degree verifies the formula for these intersection products predicted by physicists through Quantum cohomology~\cite{va92}~\cite{in91}~\cite{wi94}. We arrive at the degree by proving a version of the classical Pieri's formula on the variety $X$, using a cell decomposition of a space that lies in between $X$ and $\kappa (X)$.Comment: 18 pages, Latex documen

Output Feedback Invariants

The paper is concerned with the problem of determining a complete set of invariants for output feedback. Using tools from geometric invariant theory it is shown that there exists a quasi-projective variety whose points parameterize the output feedback orbits in a unique way. If the McMillan degree $n\geq mp$, the product of number of inputs and number of outputs, then it is shown that in the closure of every feedback orbit there is exactly one nondegenerate system.Comment: 15 page

Integrating genomics and phylogenetics in understanding the history of Trichinella species

In 2004, funding was received by Washington University’s Genome Sequencing Center through NHGRI, to completely sequence several nematode genomes as part of a holistic effort to advance our understanding of the human genome and evolution within the Metazoa. Trichinella spiralis was among this group of worms because of its strategic location at the base of the phylum Nematoda, and the belief that extant species represented an ancient divergent event that occurred as early as the Paleozoic. At the same time, a concerted effort was put forth to solidify the phylogeny of extant species of Trichinella based upon molecular analyses of a multi-gene system to understand the history of the genus and thereby enhance utilization of the forthcoming sequence data. Since the inception of this research, several findings have emerged: (1) the size of T. spiralis genome estimated by flow cytometry (71.3 Mb) is substantially smaller than originally predicted (270 Mb); (2) to date, a subset of the total of 3,534,683 sequences have been assembled into a 59.3 Mb unique sequence; (3) 19% of the assembled sequence is comprised of repetitive elements; and (4) sequence data are predicated upon extant T. spiralis which probably diverged as little as 20 million years ago. Thus, the utility of the T. spiralis genome as representative of an archaic species must be tempered with the knowledge that encapsulated and non-encapsulated clades probably separated during the mid-Miocene as temperate ecosystems changed

Shorter Leukocyte Telomere Length in Relation to Presumed Nonalcoholic Fatty Liver Disease in Mexican-American Men in NHANES 1999-2002.

Leukocyte telomere length is shorter in response to chronic disease processes associated with inflammation such as diabetes mellitus and coronary artery disease. Data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2002 was used to explore the relationship between leukocyte telomere length and presumed NAFLD, as indicated by elevated serum alanine aminotransferase (ALT) levels, obesity, or abdominal obesity. Logistic regression models were used to evaluate the relationship between telomere length and presumed markers of NAFLD adjusting for possible confounders. There was no relationship between elevated ALT levels, abdominal obesity, or obesity and telomere length in adjusted models in NHANES (OR 1.13, 95% CI 0.48-2.65; OR 1.17, 95% CI 0.52-2.62, resp.). Mexican-American men had shorter telomere length in relation to presumed NAFLD (OR 0.07, 95% CI 0.006-0.79) and using different indicators of NAFLD (OR 0.012, 95% CI 0.0006-0.24). Mexican origin with presumed NAFLD had shorter telomere length than men in other population groups. Longitudinal studies are necessary to evaluate the role of telomere length as a potential predictor to assess pathogenesis of NALFD in Mexicans

SUPPRESSION AND STIMULATION OF IMMUNOGLOBULIN SYNTHESIS BY AGENTS PRESENT IN RHEUMATOID SYNOVIAL EFFUSIONS

SUMMARY Synovial effusions from 14 patients with rheumatoid arthritis contain factors capable of enhancing and suppressing the production of immunoglobulin when added to normal peripheral lymphocyte cultures in vitro. Utilizing a radioactive immune coprecipitation technique it could be demonstrated that enhancement was observed upon addition of relatively small amounts of synovial fluid, while addition of higher amounts resulted in suppression of immunoglobulin synthesis. Nine of ten non-rheumatoid joint effusions showed neither enhancing nor suppressing activities. The possible relationship of these events to lymphokine production in the joint is discusse