Commuting families in Hecke and Temperley-Lieb algebras

Abstract We define analogs of the Jucys-Murphy elements for the affine Temperley-Lieb algebra and give their explicit expansion in terms of the basis of planar Brauer diagrams. These Jucys-Murphy elements are a family of commuting elements in the affine Temperley-Lieb algebra, and we compute their eigenvalues on the generic irreducible representations. We show that they come from Jucys-Murphy elements in the affine Hecke algebra of type A, which in turn come from the Casimir element of the quantum group . We also give the explicit specializations of these results to the finite Temperley-Lieb algebra.12

Composition of South Dakota Silages

Questions are sometimes raised about the nutritional quality of silages which are harvested and put up in South Dakota. Therefore, chemical data on 1973-75 samples from throughout South Dakota were averaged and subjected to statistical treatment by the coefficient of variation methods. Comparisons were made with United States values on similar feed as reported in the Atlas of Nutritional Data on United States and Canadian Feeds and published by the National Academy of Sciences (NAS, 1971). Total digestible nutrient values (TDN\u27s) were calculated on the South Dakota feeds by use of the digestion coefficients listed in the NAS (1971) reference

Suicide and socioeconomic context in the Appalachian region

Significant economic changes have occurred over the past thirty years that have altered the geoeconomic landscape of the United States. Although a considerable literature examines economic impacts that have resulted from these changes, there has been less work devoted to understanding the extraeconomic affects of economic change. Many places in the U.S. have experienced large-scale employment and industry losses over the past thirty years. At the same time some places have experienced rapid industrial and employment growth. Together these events represent the continued process of geographic uneven development and provide the context for examining potential affects that economic conditions and elements of change may have on local populations.;Some of the potential extraeconomic affects of large-scale economic changes include increasing levels of stress, anxiety, depression, and generally poor mental health among populations who suffer adversity from these changes. Increasing incidence of suicide is a possible outcome of these processes of economic change. This dissertation examines geographic variability in rates and trends in suicide for two distinct time periods 1980-1990 and 1990-2000 in the Appalachian region. Over the period 1980 through 2000 a number of broad swings have occurred in the U.S. economy; an economic recession in the early 1980s, post-recession structural adjustment in the mid-to-late 1980s, another economic recession in the early 1990s, followed by several years of economic growth through the end of the 1990s.;Associations between aggregate rates of suicide, trends in suicide, socioeconomic setting (context), and industrial changes are examined among labor market areas in the Appalachian region. The first part of the analysis identifies and describes geographic variability in rates and trends of suicide along with corresponding measures of socioeconomic context and industrial change. The second part of the analysis examines statistical associations between aggregate rates of suicide, trends in suicide, and measures of socioeconomic and industrial change.;The results suggest that there are persistent, positive associations between rurality (measured by percent urban population and population density) and aggregate rates of suicide for both age-groups and time-periods. The models for suicide trends also suggest a persistent association with measures of rurality, although the changing direction of the association is more difficult to assess and may be complicated by suggestions that decreases in rates of suicide in the 1990s were influenced by increased use of antidepressant medications. The models used in this analysis, in general perform poorly, in terms of identifying associations between specific measures of socioeconomic context, industrial change, aggregate suicide rates, and trends in suicide

Frequency stability characterization of a broadband fiber Fabry-Perot interferometer

An optical etalon illuminated by a white light source provides a broadband comb-like spectrum that can be employed as a calibration source for astronomical spectrographs in radial velocity (RV) surveys for extrasolar planets. For this application the frequency stability of the etalon is critical, as its transmission spectrum is susceptible to frequency fluctuations due to changes in cavity temperature, optical power and input polarization. In this paper we present a laser frequency comb measurement technique to characterize the frequency stability of a custom-designed fiber Fabry-Perot interferometer (FFP). Simultaneously probing the stability of two etalon resonance modes, we assess both the absolute stability of the etalon and the long-term stability of the cavity dispersion. We measure mode positions with MHz precision, which corresponds to splitting the FFP resonances by a part in 500 and to RV precision of ~1 m/s. We address limiting systematic effects, including the presence of parasitic etalons, that need to be overcome to push the metrology of this system to the equivalent RV precision of 10 cm/s. Our results demonstrate a means to characterize environmentally-driven perturbations of etalon resonance modes across broad spectral bandwidths, as well as motivate the benefits and challenges of FFPs as spectrograph calibrators.Comment: 15 pages, 9 figures, accepted to Opt. Expres

The Hexaemeron in Peter Comestor’s \u3cem\u3eHistoria Scholastica\u3c/em\u3e

As a part of the larger Historia Scholastica Project, we are transcribing and translating text from the “Genesis” chapter of the Historia Scholastica found in the Albertson’s Library. Our work began in fall of 2018. Our goal is to locate source material that informed Comestor’s understanding of the content of “Genesis” to better understand and therefore better translate Comestor. We are researching sources that possibly contributed to Comestor’s understanding of cosmology, philosophy, and the biblical creation account, in addition to transcribing and translating the text. Our methodology focuses on ten lines per week, applying textual criticism to identify textual differences and assist where our copy is damaged. We are using Patrologia Latinae 198, the Lugdunensis copy on Wiki, and the online Internet Archive of the Historia Scholastica located in Strasbourg, France. We then filter any possible translations through the lens of biblical studies taking place in medieval France in the late 12th and early 13th centuries. Our goal is to produce 100 lines of quality Latin by the end of the semester; to date we have completed approximately 40%. This project will provide groundwork for future researchers in other portions of the Historia Scholastica

Biomonitoring Study of a Constructed Wetland Site Treating Acid Mine Drainage

Acid mine drainage (AMD) from an underground coal mine in the Jones Branch watershed in McCreary County, KY, substantially reduced water quality in Jones Branch. Downstream from the mine seeps, the pH was routinely below 4.5 and concentrations of most heavy metals, especially iron, were elevated. A cattail wetland (1,022 m2) was constructed on Jones Branch in 1989 to obviate the effects of the AMD. Monthly chemical monitoring was performed on the water from above, from below, and from the 26 cells within the wetland. Based on chemical monitoring, the wetland initially improved water quality, increasing the pH and removing substantial amounts of heavy metals. Beginning in the spring of 1991, water quality at the wetland outfall began to decline, and has not improved to date. To augment the chemical monitoring, a biomonitoring study was initiated in the spring of 1990. Acute 48-hr static tests were conducted with newly hatched fathead minnows (Pimephales promelas). Water samples were obtained from the seep inlet, four cells within the wetland, and from Jones Branch above and below the wetland site. Median lethal concentration (LC50) values determined monthly reflect the decline in water quality at the outfall over time. However, within the wetland there was gradual improvement in survivability from inlet to outlet, providing evidence that the wetland was responsible for a modest improvement in water quality

Archeops: an instrument for present and future cosmology

Archeops is a balloon-borne instrument dedicated to measure the cosmic microwave background (CMB) temperature anisotropies. It has, in the millimetre domain (from 143 to 545 GHz), a high angular resolution (about 10 arcminutes) in order to constrain high l multipoles, as well as a large sky coverage fraction (30%) in order to minimize the cosmic variance. It has linked, before WMAP, Cobe large angular scales to the first acoustic peak region. From its results, inflation motivated cosmologies are reinforced with a flat Universe (Omega_tot=1 within 3%). The dark energy density and the baryonic density are in very good agreement with other independent estimations based on supernovae measurements and big bang nucleosynthesis. Important results on galactic dust emission polarization and their implications for Planck are also addressed.Comment: 4 pages, 2 figures, to appear in Proceedings of the Multiwavelength Cosmology Conference, June 2003, Mykonos Island, Greec

Cosmological Parameter Extraction from the First Season of Observations with DASI

The Degree Angular Scale Interferometer (\dasi) has measured the power spectrum of the Cosmic Microwave Background anisotropy over the range of spherical harmonic multipoles 100<l<900. We compare this data, in combination with the COBE-DMR results, to a seven dimensional grid of adiabatic CDM models. Adopting the priors h>0.45 and 0.0<=tau_c<=0.4, we find that the total density of the Universe Omega_tot=1.04+/-0.06, and the spectral index of the initial scalar fluctuations n_s=1.01+0.08-0.06, in accordance with the predictions of inflationary theory. In addition we find that the physical density of baryons Omega_b.h^2=0.022+0.004-0.003, and the physical density of cold dark matter Omega_cdm.h^2=0.14+/-0.04. This value of Omega_b.h^2 is consistent with that derived from measurements of the primordial abundance ratios of the light elements combined with big bang nucleosynthesis theory. Using the result of the HST Key Project h=0.72+/-0.08 we find that Omega_t=1.00+/-0.04, the matter density Omega_m=0.40+/-0.15, and the vacuum energy density Omega_lambda=0.60+/-0.15. (All 68% confidence limits.)Comment: 7 pages, 4 figures, minor changes in response to referee comment

Specific Isotopic Labeling and Photooxidation-linked Structural Changes in the Manganese-stabilizing Subunit of Photosystem II

Photosystem II (PSII) oxidizes water to molecular oxygen; the catalytic site is a cluster of four manganese ions. The catalytic site undergoes four sequential light-driven oxidation steps to form oxygen; these sequentially oxidized states are referred to as the Sn states, where n refers to the number of oxidizing equivalents stored. The extrinsic manganese stabilizing protein (MSP) of PSII influences the efficiency and stability of the manganese cluster, as well as the rates of the S state transitions. To understand how MSP influences photosynthetic water oxidation, we have employed isotope editing and difference Fourier transform infrared spectroscopy. MSP was expressed in Escherichia coli under conditions in which MSP aspartic and glutamic acid residues label at yields of 65 and 41%, respectively. Asparagine and glutamine were also labeled by this approach. GC/MS analysis was consistent with minimal scrambling of label into other amino acid residues and with no significant scrambling into the peptide bond. Selectively labeled MSP was then reconstituted to PSII, which had been stripped of native MSP. Difference Fourier transform infrared spectroscopy was used to probe the S 1QA to S2QA- transition at 200 K, as well as the S1QB to S2Q B- transition at 277 K. These experiments show that aspargine, glutamine, and glutamate residues in MSP are perturbed by photooxidation of manganese during the S1 to S2 transition