Non-linear unsteady wing theory, part 1. Quasi two-dimensional behavior: Airfoils and slender wings

The initial phases of a study of the large-amplitude unsteady aerodynamics of wings in severe maneuver are reported. The research centers on vortex flows, their initiation at wing surfaces, their subsequent convection, and interaction dynamically with wings and control surfaces. The focus is on 2D and quasi-2D aspects of the problem and features the development of an exact nonlinear unsteady airfoil theory as well as an approach to the crossflow problem for slender wing applications including leading-edge separation. The effective use of interactive on-line computing in quantifying and visualizing the nonsteady effects of severe maneuver is demonstrated. Interactive computational work is now possible, in which a maneuver can be initiated and its effects observed and analyzed immediately

Long-term human hematopoiesis in the SCID-hu mouse.

Coimplantation of small fragments of human fetal thymus and fetal liver into immunodeficient SCID mice resulted in the formation of a unique structure (Thy/Liv). Thereafter, the SCID-hu mice showed reproducible and long-term reconstitution of human hematopoietic activity. For periods lasting 5-11 mo after transplantation, active T lymphopoiesis was observed inside the grafts and cells that were negative for T cell markers were found to have colony-forming units for granulocyte/macrophage (CFU-GM) and erythroid burst-forming unit (BFU-E) activity in the methylcellulose colony assay. In addition, structures similar to normal human bone marrow were observed inside the Thy/Liv grafts, consisting of blast cells, mature and immature forms of myelomonocytic cells, and megakaryocytes. These data indicate long-term maintenance, in vivo, of human progenitor cells for the T lymphoid, myelomonocytic, erythroid, and megakaryocytic lineages. The role of the implanted fetal liver fragments was analyzed using HLA-mismatched Thy/Liv implants. The HLA type of the liver donor was found on T cells and macrophages in the graft. In addition, cells grown in the methylcellulose colony assay and cells in a bone marrow-like structure, the thymic isle, expressed the HLA type of the liver donor. Thus, the Thy/Liv implants provided a microenvironment in which to follow human hematopoietic progenitor cells for multiple lineages. The formation of the Thy/Liv structures also results in a continuous source of human T cells in the peripheral circulation of the SCID-hu mouse. Though present for 5-11 mo, these cells did not engage in a xenograft (graft-versus-host) reaction. This animal model, the first in which multilineage human hematopoietic activity is maintained for long periods of time, should be useful for the analysis of human hematopoiesis in vivo

Control of poultry disease outbreaks (1990)

"Poultry owners should immediately begin an investigation if a disease is suspected in a flock. Obvious disease signs and symptoms can be identified on the farm while others may require laboratory assistance for proper diagnosis."--First page.E.L. McCune (School of Veterinary Medicine), and J.M. Vandepopuliere (Animal Sciences Department)Revised 5/90/4

Lubrication system with tolerance for reduced gravity

A lubrication system includes an auxiliary lubricant tank 48, a supply conduit 58 extending from a source of lubricant 26 to the auxiliary lubricant tank. A reduced-G bypass line 108 branches from the conduit and enters the auxiliary tank at a first elevation E.sub.1. The system also includes an auxiliary tank discharge conduit 116, a portion of which resides within the tank. The resident portion has an opening 122 at least partially at a second elevation E.sub.2 higher than the first elevation

Control of poultry disease outbreaks (1993)

Poultry owners should immediately begin an investigation if a disease is suspected in a flock. Obvious disease signs and symptoms can be identified on the farm, while others may require laboratory assistance for proper diagnosis. Missouri poultry owners have several state-operated and commercial laboratories available. The services of these laboratories are generally available at minimal cost. They are equipped to identify disease problems and make recommendations for control

It all just clicked: a longitudinal perspective on transitions within University

This paper explores the transitions that a group of students, admitted from further education colleges as part of broader widening access initiative at a Scottish research–intensive university, made across the lifetime of their degrees. It investigates how they negotiate their learning careers beyond the first year, and how they (re)define their approaches to independent learning as they progress to the later years of their courses. Evidence is drawn from 20 students who were interviewed during each of their three or four years of study to provide a longitudinal account of their experiences of engagement and participation at the university. We draw attention to three ways in which the students made transitions across the course of their degrees: to increased knowledge of the conventions of academic writing; to enhanced critical skills; and to practical strategies to prioritise learning

Lifting-line theory for subsonic axial compressor rotors

July 1972Includes bibliographical references (leaf 25)The three-dimensional compressible vortex theory of an axial compressor rotor or ducted fan is extended by relating blade loading to blade geometry in the lifting-line approximation. The resulting integral equation, which is valid up to high subsonic Mach numbers, is solved for both design and off-design problems. It is shown that three-dimensional effects must be taken into account, for rotors with non-uniform spanwise loading, in order to obtain accurate predictions of flow angles and other performance parameters.This Research carried out in the Gas Turbine Laboratory, M.I.T., supported by NASA Lewis Research Center, under Grant No. NGL 22-009-38

Direct evidence for thymic function in adult humans.

The understanding of human thymic function and evaluation of its contribution to T cell homeostasis are matters of great importance. Here we report the development of a novel assay to quantitate the frequency and diversity of recent thymic emigrants (RTEs) in the peripheral blood of humans. Such cells were defined by the presence of T cell receptor (TCR) rearrangement deletion circles (DCs), episomal byproducts of TCR-beta V(D)J rearrangement. DCs were detected in T cells in the thymus, cord blood, and adult peripheral blood. In the peripheral blood of adults aged 22 to 76 years, their frequency was highest in the CD4(+)CD45RA(+) CD62L(+) subpopulation of naive T cells. TCR DCs were also observed in other subpopulations of peripheral blood T cells, including those with the CD4(+)CD45RO(-)CD62L(+) and CD4(+)CD45RO(+)CD62L(+) phenotypes. RTEs were observed to have more than one Vbeta rearrangement, suggesting that replenishment of the repertoire in the adult is at least oligoclonal. These results demonstrate that the normal adult thymus continues to contribute, even in older individuals, a diverse set of new T cells to the peripheral circulation

Stimulus-Mediated Ultrastable Radical Formation

Organic radicals are reactive, often short-lived species typically formed through either the addition of a chemical agent or photochemical means. On account of their open-shell electronic structure they have attracted attention based upon their magnetic properties and desirable spectroscopic behaviour. Redox sensitive molecules such as viologen (V) undergo one-electron reductions to form radical species. These species hold significant potential in myriad applications but are limited as they are rapidly quenched by oxygen in air. Using methyl viologen as an example, we show that the MV radical (MV+·) can be formed through electrochemical, chemical, photochemical and a novel thermal stimulus in various Deep Eu- tectic Solvents (DES) and was found to be exceptionally stable. The conductive properties of DES allowed for fabrication of an aerobic electrochromic device through a straightforward, economical approach. Our report represents a unique approach to extend reactive radical lifetimes in air without alteration of the parent structure.J.A.M. would like to acknowledge the EPSRC for a PhD studentship (EP/K503009/1). O.A.S. acknowledges ERC Consolidator grant CAM-RIG (No.726470) and UK Engineering and Physical Sciences Research Council grant EP/L027151/1. M.F.K. and E.R. acknowledge Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy and the National Foundation for Research, Technology and Development), the OMV Group and the EPSRC (IAA Follow-on Fund)