A note on log-convexity of q-Catalan numbers

The q-Catalan numbers studied by Carlitz and Riordan are polynomials in q with nonnegative coefficients. They evaluate, at q=1, to the Catalan numbers: 1, 1, 2, 5, 14,..., a log-convex sequence. We use a combinatorial interpretation of these polynomials to prove a q-log-convexity result. The sequence of q-Catalan numbers is not q-log-convex in the narrow sense used by other authors, so our work suggests a more flexible definition of q-log convex be adopted

Peter M. Flanigan to Senator James O. Eastland, 5 March 1973

Copy typed letter signed dated 5 March 1973 from Peter M. Flanigan, Assistant to the President for International Economic Affairs, to Eastland, re: export of logs to Japan, wood product prices. Attached: carbon typed letter dated 8 March 1973 from Eastland to Tom Korologos, Deputy Assistant to the President, re: transmission of letter from Tom W. Conger, Jr. to president on above topics.https://egrove.olemiss.edu/joecorr_f/1062/thumbnail.jp

Is S-adenosylmethionine (SAMe) an Effective Drug to Help Treat Patients with Depression?

Objective: The objective of the selective EBM review is to determine whether or not “Is Sadenosylmethionine (SAMe) an Effective Drug to Help Treat Patients with Depression?” Study Design: A systematic review of three randomized controlled trials (RCTs) published between 2016-2020. Data Sources: All three RCTs were discovered using PubMed. The articles were published in English in peer-reviewed journals and selected based on applicability to the clinical question. Outcome Measured: A reduction in depressive symptoms was the outcome measured in all three studies using the Montgomery-Asbery Depression Rating Scale (MADRS). The mean change in baseline was calculated once intervention was received. Results: In the RCT led by Sarris J, Murphy J, Stough C, et al., monotherapy with SAMe in combination with co-factor vitamin B12 and folininc acid led to a reduction in depressive symptoms compared with the control group (P = 0.13), indicated by a mean change from baseline of -11.4. In the RCT led by Sarris J, Bryne GJ, Bousman C, et al., adjunctive therapy with SAMe, in combination with co-factor B12 and folinic acid, led to a reduction in depressive symptoms, indicated by a mean change from baseline of -11.4 (P = 0.51). Lastly, Sarris J, Byrne GJ, Stough C, et al. illustrated a reduction in depressive symptoms using a nutraceutical combination with SAMe, indicated by a mean change from baseline of -9.95 with a statistical significance of P = 0.33 in the SAMe treatment group. Conclusion: All three studies in this review demonstrated that SAMe did not lead to a significant reduction in depressive symptoms as measured by the MADRS. In fact, two of the three studies showed a greater reduction in depressive symptoms with the placebo than withintervention with SAMe. This suggests that SAMe is not an effective or beneficial treatment for patients with depression. Due to high placebo response rates, future studies should include a placebo run-in period

Robotic and automatic welding development at the Marshall Space Flight Center

Welding automation is the key to two major development programs to improve quality and reduce the cost of manufacturing space hardware currently undertaken by the Materials and Processes Laboratory of the NASA Marshall Space Flight Center. Variable polarity plasma arc welding has demonstrated its effectiveness on class 1 aluminum welding in external tank production. More than three miles of welds were completed without an internal defect. Much of this success can be credited to automation developments which stabilize the process. Robotic manipulation technology is under development for automation of welds on the Space Shuttle's main engines utilizing pathfinder systems in development of tooling and sensors for the production applications. The overall approach to welding automation development undertaken is outlined. Advanced sensors and control systems methodologies are described that combine to make aerospace quality welds with a minimum of dependence on operator skill

DEVELOPING A PROJECT MANAGER COMPETENCY MODEL TO BETTER SERVE THE WARFIGHTER AND THE DOD

As of today, the Department of Defense (DOD) project management competencies are structured differently from industry. Industry has made advancements in project management that the DOD does not currently take advantage of. By better aligning the DOD and PMI competency standards we can decrease cost, schedule, and performance issues. Based on previous research on the topic, the current DOD competency model is not sufficient for assessing today’s program managers. The purpose of this research is to use the three PMI industry standards to develop a survey tool to better serve the DOD acquisition workforce. We were able to create this survey tool and hope that, by using this survey tool, future research teams will be able to effectively gauge the acquisition community’s correlation between the three PMI standards and the current DOD workload. The information gathered from this research can be useful not only to DOD acquisition communities, but also can set future guidelines to program managers in order to save the DOD on schedule, cost, and performance.Civilian, Department of the NavyCivilian, Department of the NavyApproved for public release. Distribution is unlimited

Potential formulation of the dispersion relation for a uniform, magnetized plasma with stationary ions in terms of a vector phasor

The derivation of the helicon dispersion relation for a uniform plasma with stationary ions subject to a constant background magnetic field is reexamined in terms of the potential formulation of electrodynamics. Under the same conditions considered by the standard derivation, the nonlinear self-coupling between the perturbed electron flow and the potential it generates is addressed. The plane wave solution for general propagation vector is determined for all frequencies and expressed in terms of a vector phasor. The behavior of the solution as described in vacuum units depends upon the ratio of conductivity to the magnitude of the background field. Only at low conductivity and below the cyclotron frequency can significant propagation occur as determined by the ratio of skin depth to wavelength.Comment: 10 pages, 6 figures, major revision, final version, to appear in Po

Immigration Enforcement and Fairness to Would-Be Immigrants

This chapter argues that governments have a duty to take reasonably effective and humane steps to minimize the occurrence of unauthorized migration and stay. While the effects of unauthorized migration on a country’s citizens and institutions have been vigorously debated, the literature has largely ignored duties of fairness to would-be immigrants. It is argued here that failing to take reasonable steps to prevent unauthorized migration and stay is deeply unfair to would-be immigrants who are not in a position to bypass visa regulations. Importantly, the argument here is orthogonal to the debate as to how much and what kinds of immigration ought to be allowed

Stationary and Axisymmetric Solutions of Higher-Dimensional General Relativity

We study stationary and axisymmetric solutions of General Relativity, i.e. pure gravity, in four or higher dimensions. D-dimensional stationary and axisymmetric solutions are defined as having D-2 commuting Killing vector fields. We derive a canonical form of the metric for such solutions that effectively reduces the Einstein equations to a differential equation on an axisymmetric D-2 by D-2 matrix field living in three-dimensional flat space (apart from a subclass of solutions that instead reduce to a set of equations on a D-2 by D-2 matrix field living in two-dimensional flat space). This generalizes the Papapetrou form of the metric for stationary and axisymmetric solutions in four dimensions, and furthermore generalizes the work on Weyl solutions in four and higher dimensions. We analyze then the sources for the solutions, which are in the form of thin rods along a line in the three-dimensional flat space that the matrix field can be seen to live in. As examples of stationary and axisymmetric solutions, we study the five-dimensional rotating black hole and the rotating black ring, write the metrics in the canonical form and analyze the structure of the rods for each solution.Comment: 43 pages, v2: typos fixed, refs adde