Experiment and Theory in Computations of the He Atom Ground State

Extensive variational computations are reported for the ground state energy of the non-relativistic two-electron atom. Several different sets of basis functions were systematically explored, starting with the original scheme of Hylleraas. The most rapid convergence is found with a combination of negative powers and a logarithm of the coordinate s = r_{1}+ r_{2}. At N=3091 terms we pass the previous best calculation (Korobov's 25 decimal accuracy with N=5200 terms) and we stop at N=10257 with E = -2.90372 43770 34119 59831 11592 45194 40444 ... Previous mathematical analysis sought to link the convergence rate of such calculations to specific analytic properties of the functions involved. The application of that theory to this new experimental data leaves a rather frustrating situation, where we seem able to do little more than invoke vague concepts, such as ``flexibility.'' We conclude that theoretical understanding here lags well behind the power of available computing machinery.Comment: 15 page

The University Library and the Problem of Knowledge

The problem of knowledge, on the broadest level, is that the scope, specialization, and cross-disciplinarity of the research enterprise have long surpassed any overarching framework. The key question, on the campus level, is whether the development of research collections by the library is aligned with the university’s strategic aims and overall institutional development. A straightforward (though uncommon) way to make the university/library relationship more effective in this regard is for the library to have a meaningful role in the academic program review process. This essay describes such a role, singling out the particular situation of some 40 predominately undergraduate institutions that have been reclassified as research-level in the Carnegie scheme. As a rule, when a university’s institutional identity or ambition outstrips its library’s capability, collection development is bound to become a campuswide concern.</jats:p

Reassessing Prospects for the Open Access Movement

Open access may well be a turning point for the scholarly communication system, but not on the basis claimed by its advocates. As opposed to the claim that open access means a less costly system, in reality it entails redundant expenditures and inflationary pressures. The true significance of open access, involving processes of institutional development of the system, has not entered into the public debate. Such processes are chiefly twofold: the adjustment of the open-access movement to the different needs and cultures of the various stakeholder groups, and the advent of a more complex system architecture that facilitates research productivity and scholarly innovation.</jats:p

The Department of Defense Acquisition Workforce: Background, Analysis, and Questions for Congress

[Excerpt] This report provides background on the Department of Defense (DOD) acquisition workforce. Specifically, the report addresses the following questions: What is the acquisition workforce? What is the current size of the acquisition workforce? How has Congress sought to improve the acquisition workforce in the past? What are some potential questions for Congress to explore in the area of acquisition workforce management to improve acquisitions

The Strength of Weak Ties in Electronic Development of the Scholarly Communication System

published or submitted for publicatio

Computations in Large N Matrix Mechanics

The algebraic formulation of Large N matrix mechanics recently developed by Halpern and Schwartz leads to a practical method of numerical computation for both action and Hamiltonian problems. The new technique posits a boundary condition on the planar connected parts X_w, namely that they should decrease rapidly with increasing order. This leads to algebraic/variational schemes of computation which show remarkably rapid convergence in numerical tests on some many- matrix models. The method allows the calculation of all moments of the ground state, in a sequence of approximations, and excited states can be determined as well. There are two unexpected findings: a large d expansion and a new selection rule for certain types of interaction.Comment: 27 page

Faculty-Librarian Collaboration in Building the Curriculum for the Millennium: The US Experience

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68104/2/10.1177_034003529902500402.pd

In Silico Modeling the Effects of Missense Mutations Causing Snyder-Robinson Syndrome and Rescuing the Effects by Small Molecules Binding

Snyder-Robinson Syndrome (SRS) is an X-linked mental retardation disorder. Three missense mutations (G56S, V132G and I150T) on human spermine synthase (SMS) were reported to cause SRS. SMS is an important enzyme which converts spermindine into spermine, both of which are two polyamines controlling the normal cell growth and development. In vitro experiments showed that the dimer conformation played a crucial role on the SMS function. Our in silico studies including energy calculation, pKa calculation and molecular dynamics (MD) simulation based on the available 3D structure of SMS revealed that these mutations affected SMS function by affecting the dimer affinity, monomer stability or hydrogen bond network. One of the above sites, G56S, is accessible from the water phase, thus it provides the opportunity to rescue the disease-causing effect by binding an appropriate small molecule to the vicinity of the mutation site. Currently we run MD simulation to generate multiple receptor conformations and identified two potent binding pockets. Then two programs, Surflex and Autodock Vina, were applied for structure-based virtual screening (SBVS) and a consensus list of about 200 common compounds selected by both of the programs was created, and these compounds were tested experimentally by our collaborators

Taxonomic changes in the gut microbiota are associated with cartilage damage independent of adiposity, high fat diet, and joint injury

Abstract Lipodystrophic mice are protected from cartilage damage following joint injury. This protection can be reversed by the implantation of a small adipose tissue graft. The purpose of this study was to evaluate the relationship between the gut microbiota and knee cartilage damage while controlling for adiposity, high fat diet, and joint injury using lipodystrophic (LD) mice. LD and littermate control (WT) mice were fed a high fat diet, chow diet, or were rescued with fat implantation, then challenged with destabilization of the medial meniscus surgery to induce osteoarthritis (OA). 16S rRNA sequencing was conducted on feces. MaAslin2 was used to determine associations between taxonomic relative abundance and OA severity. While serum LPS levels between groups were similar, synovial fluid LPS levels were increased in both limbs of HFD WT mice compared to all groups, except for fat transplanted animals. The Bacteroidetes:Firmicutes ratio of the gut microbiota was significantly reduced in HFD and OA-rescued animals when compared to chow. Nine novel significant associations were found between gut microbiota taxa and OA severity. These findings suggest the presence of causal relationships the gut microbiome and cartilage health, independent of diet or adiposity, providing potential therapeutic targets through manipulation of the microbiome

Infrared Imaging of Boundary Layer Transition Flight Experiments

The Hypersonic Thermodynamic Infrared Measurement (HYTHIRM) project is presently focused on near term support to the Shuttle program through the development of an infrared imaging capability of sufficient spatial and temporal resolution to augment existing on-board Orbiter instrumentation. Significant progress has been made with the identification and inventory of relevant existing optical imaging assets and the development, maturation, and validation of simulation and modeling tools for assessment and mission planning purposes, which were intended to lead to the best strategies and assets for successful acquisition of quantitative global surface temperature data on the Shuttle during entry. However, there are longer-term goals of providing global infrared imaging support to other flight projects as well. A status of HYTHIRM from the perspective of how two NASA-sponsored boundary layer transition flight experiments could benefit by infrared measurements is provided. Those two flight projects are the Hypersonic Boundary layer Transition (HyBoLT) flight experiment and the Shuttle Boundary Layer Transition Flight Experiment (BLT FE), which are both intended for reducing uncertainties associated with the extrapolation of wind tunnel derived transition correlations for flight application. Thus, the criticality of obtaining high quality flight data along with the impact it would provide to the Shuttle program damage assessment process are discussed. Two recent wind tunnel efforts that were intended as risk mitigation in terms of quantifying the transition process and resulting turbulent wedge locations are briefly reviewed. Progress is being made towards finalizing an imaging strategy in support of the Shuttle BLT FE, however there are no plans currently to image HyBoLT