2,022 research outputs found
Simulator evaluation of optimal thrust management/fuel conservation strategies for airbus aircraft on short haul routes
The feasibility of incorporating optimal concepts into a practical system was determined. Various earlier theoretical analyses were confirmed, and insight was gained into the sensitivity of fuel conservation strategies to nonlinear and second order aerodynamic and engine characteristics. In addition to the investigation of optimal trajectories the study ascertained combined fuel savings by utilizing various procedure-oriented improvements such as delayed flap/decelerating approaches and great circle navigation
Computer Program for Assessing the Economic Feasibility of Solar Energy for Single Family Residences and Light Commercial Applications
Computer program, SHCOST, was used to perform economic analyses of operational test sites. The program allows consideration of the economic parameters which are important to the solar system user. A life cycle cost and cash flow comparison is made between a solar heating system and a conventional system. The program assists in sizing the solar heating system. A sensitivity study and plot capability allow the user to select the most cost effective system configuration
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CD28 interaction with B7 costimulates primary allogeneic proliferative responses and cytotoxicity mediated by small, resting T lymphocytes.
Engagement of the CD3/T cell antigen receptor complex on small, resting T cells is insufficient to trigger cell-mediated cytotoxicity or to induce a proliferative response. In the present study, we have used genetic transfection to demonstrate that interaction of the B7-BB1 B cell activation antigen with the CD28 T cell differentiation antigen costimulates cell-mediated cytotoxicity and proliferation initiated by either anti-CD2 or anti-CD3 monoclonal antibody (mAb). Moreover, a B7-negative Burkitt's lymphoma cell line that fails to stimulate an allogeneic mixed lymphocyte response is rendered a potent stimulator after transfection with B7. The mixed leukocyte reaction proliferative response against the B7 transfectant is inhibited by either anti-CD28 or B7 mAb. We also demonstrate that freshly isolated small, resting human T cells can mediate anti-CD3 or anti-CD2 mAb-redirected cytotoxicity against a murine Fc receptor-bearing mastocytoma transfected with human B7. These preexisting cytotoxic T lymphocytes in peripheral blood are present in both the CD4 and CD8 subsets, but are preferentially within the CD45RO+ "memory" population. While small, resting T cells apparently require costimulation by CD28/B7 interactions, this requirement is lost after T cell activation. Anti-CD3 initiates a cytotoxic response mediated by in vitro cultured T cell clones in the absence of B7 ligand. The existence of functional cytolytic T cells in the small, resting T cell population may be advantageous in facilitating rapid responses to immune challenge
Letter from Charles D. Lanier to John Muir, 1901 Aug 19.
article on the matter of the protection of the Big Trees left, it would be a most readable feature of the Review of Reviews, and at the sane time night stir up considerable interest in the matter of protecting these magnificent giants.What the present condition of the trees is, wliat dangers they ere subject to, what legislation there is on the subject, what there ought to be, and what chance there is of getting it, then, would make up perhaps the larger part of the article we have in mind We do not know that you would care to undertake such a piece of work, but we hope that you will, and we think it the more probable that you might, because the circulation of the Review of Reviews is such as to give tiny reeommendations you may have to make in regard to the preservation of the sequoya groves the widest and best introduction.We should be glad to have thisTHEAMERICAN MONTHLYREVIEW REVIEWShe REVIEW of REVIEWS CO.AugUSt 19, 190113 Astor Place, New YorkMr. John Muir,c/o Atlantic Monthly,Boston, Mass.Dear Sir:Your exceedingly charming article on the Big Trees, which I have been reading in the advance sheets of the Atlantic, has led me to wonder if you would not be willing to write a brief article for the Review of Reviews on the sequoyas, an article built on somewhat different lines, just as the Review of Reviews is rather a journalistic magazine, while the Atlentic Monthly is rather a literary magazine.Our thought had been that if you could give some of the dramatic facts of the size, age, beauty and life history of the Big Tree, the limits of its range, etc., and then proceed to make rather the larger part of the[02884], article in time for possible use in the October number, if you care to do it.This would necessitate our receiving the manuscript by about September 10 or 12. We have thought of an article of from 1,500 to 2,500 words.Your truly,P. S. - Do you happen to knov\u27 of any exceptionally good photographs of sequoyas
Production rates of neon xenon isotopes by energetic neutrons
As a first step in an experimental program to study the behavior of noble gases produced in situ in minerals, a suite of minerals and pure chemicals were irradiated with 14.5 MeV neutrons at LLNL's Rotating Target Neutron Source (RTNS-II) and production rates for noble gases were determined. While neutron effects in meteorites and lunar samples are dominated by low-energy neutron capture, more energetic cosmic-ray secondary neutrons can provide significant depth-dependent contributions to production of cosmogenic nuclides through endothermic reactions such as (n,2n), (n,np), (n,d) and (n,alpha). Production rates for nuclides produced by cosmic-ray secondary neutrons are therefore useful in interpreting shielding histories from the relative abundances of cosmogenic nuclides. Absolute production cross sections were calculated from isotope dilution analyses of NaCl, Mg, CsCl, and Ba(NO3)2 samples, assuming purity, stoichiometry, and quantitative noble gas retention and extraction. Relative production cross sections determined from neon isotopic ratios in the mineral samples were also considered in evaluating the neon production cross sections. Results are presented
Identification of a Candidate CD5 Homologue in the Amphibian Xenopus laevis
We identified a novel T cell Ag in the South African clawed toad (Xenopus laevis) by a mAb designated 2B1. This Ag is present in relatively high levels on most thymocytes, approximately 65% of splenocytes, 55% of PBL, and 65% of intestinal lymphocytes, but is rarely seen on IgM+ B cells in any of these tissues. Lymphocytes bearing the 2B1 Ag proliferate in response to stimulation with Con A or PHA, whereas the 2B1- lymphocytes are reactive to LPS. Biochemical analysis indicates that this Ag is a differentially phosphorylated glycoprotein of 71 to 82 kDa. The protein core of 64 kDa bears both N- and O-linked carbohydrate side chains. The amino-terminal protein sequence of the 2B1 Ag shares significant homology with both the macrophage scavenger receptor type 1 motif and the mammalian CD5/CD6 family. The biochemical characteristics and cellular distribution of the 2B1 Ag suggest that it represents the CD5 homologue in X. laevis. While T cells constitutively express this highly conserved molecule, Xenopus B cells acquire the CD5 homologue only when they are stimulated in the presence of T cell
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The T cell antigen receptor complex expressed on normal peripheral blood CD4-, CD8- T lymphocytes. A CD3-associated disulfide-linked gamma chain heterodimer.
IL-2-dependent cell lines were established from normal peripheral blood T lymphocytes that express neither CD4 nor CD8 differentiation antigens. CD3+,4-,8- cell lines from 15 different donors failed to react with WT31, an mAb directed against the T cell antigen receptor alpha/beta heterodimer. Anti-Leu-4 mAb was used to isolate the CD3/T cell antigen receptor complex from 125I-labeled CD3+,4-,8- (WT31-) T cells. Using detergent conditions that preserved the CD3/T cell antigen receptor complex, an approximately 90 kD disulfide-linked heterodimer, composed of approximately 45- and approximately 40- (or approximately 37-) kD subunits, was coimmunoprecipitated with the invariant 20-29-kD CD3 complex. Analysis of these components by nonequilibrium pH gradient electrophoresis indicated that the approximately 40-kD and approximately 37-kD subunits were similar, and quite distinct from the more basic approximately 45-kD subunit. None of these three subunits reacted with an antibody directed against a beta chain framework epitope. Heteroantiserum against a T cell receptor gamma chain peptide specifically reacted with both the approximately 37- and approximately 40-kD CD3-associated proteins, but not with the approximately 45-kD subunit. CD3+,4-,8- cells failed to transcribe substantial amounts of functional 1.3-kb beta or 1.6-kb alpha mRNA, but produced abundant 1.6-kb gamma mRNA. Southern blot analysis revealed that these CD3+,4-,8- cell lines rearranged both gamma and beta genes, and indicated that the populations were polyclonal. The expression of a CD3-associated disulfide-linked heterodimer on CD3+,4-,8- T cell lines established from normal, adult peripheral blood contrasts with prior reports describing a CD3-associated non-disulfide-linked heterodimer on CD3+/WT31- cell lines established from thymus and peripheral blood obtained from patients with immunodeficiency diseases. We propose that this discrepancy may be explained by preferential usage of the two C gamma genes in T lymphocytes
Everything Has Changed: The Depiction of the September 11, 2001 Terrorist Attacks in Historical Fiction for Young Adults
This study utilizes content analysis to examine 19 historical fiction novels for young adults, ages 12-18, which address the September 11, 2001 terrorist attacks. This study was conducted to identify any important trends regarding publication and supplemental information included in the sample, the scope of 9/11 described in the selected texts, and the diversity of the protagonists in each novel, and their connections and responses to the 9/11 attacks. Increasing numbers of 9/11 related historical fiction novels for young adults are being published that are better researched and offer readers a broader scope of the day’s events than earlier works in this genre. While white characters are most prominent, diversity is becoming more common over time, as well as the desire to portray the stories of characters that were directly affected by the terrorist attacks. Protagonists’ multifaceted grieving cycles have been a hallmark of this genre throughout time as well.Master of Science in Library Scienc
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Hypoimmunogenic Derivatives of Induced Pluripotent Stem Cells Evade Immune Rejection in Fully Immunocompetent Allogeneic Recipients
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