Antigen presenting capacity of murine splenic myeloid cells

BACKGROUND: The spleen is an important site for hematopoiesis. It supports development of myeloid cells from bone marrow-derived precursors entering from blood. Myeloid subsets in spleen are not well characterised although dendritic cell (DC) subsets are clearly defined in terms of phenotype, development and functional role. Recently a novel dendritic-like cell type in spleen named ‘L-DC’ was distinguished from other known dendritic and myeloid cells by its distinct phenotype and developmental origin. That study also redefined splenic eosinophils as well as resident and inflammatory monocytes in spleen. RESULTS: L-DC are shown to be distinct from known splenic macrophages and monocyte subsets. Using a new flow cytometric procedure, it has been possible to identify and isolate L-DC in order to assess their functional competence and ability to activate T cells both in vivo and in vitro. L-DC are readily accessible to antigen given intravenously through receptor-mediated endocytosis. They are also capable of CD8(+) T cell activation through antigen cross presentation, with subsequent induction of cytotoxic effector T cells. L-DC are MHCII(−) cells and unable to activate CD4(+) T cells, a property which clearly distinguishes them from conventional DC. The myeloid subsets of resident monocytes, inflammatory monocytes, neutrophils and eosinophils, were found to have varying capacities to take up antigen, but were uniformly unable to activate either CD4(+) T cells or CD8(+) T cells. CONCLUSION: The results presented here demonstrate that L-DC in spleen are distinct from other myeloid cells in that they can process antigen for CD8(+) T cell activation and induction of cytotoxic effector function, while both L-DC and myeloid subsets remain unable to activate CD4(+) T cells. The L-DC subset in spleen is therefore distinct as an antigen presenting cell

Alien Registration- Hey, Henry C. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/23928/thumbnail.jp

Frohlich mass in GaAs-based structures

The Frohlich interaction is one of the main electron-phonon intrinsic interactions in polar materials originating from the coupling of one itinerant electron with the macroscopic electric field generated by any longitudinal optical (LO) phonon. Infra-red magneto-absorption measurements of doped GaAs quantum wells structures have been carried out in order to test the concept of Frohlich interaction and polaron mass in such systems. These new experimental results lead to question the validity of this concept in a real system.Comment: 4 pages, 3 figure

Supporting the 'Sharing Institution' - Practical Steps Towards a More Open Teaching and Learning Culture

4th International Conference on Open RepositoriesThis presentation was part of the session : Conference PresentationsDate: 2009-05-19 03:00 PM – 04:30 PMInstitutional repositories for research output have developed progressively over the last few years. Although a primary motivation is Open Access both institutional and academic needs must also be met in order to foster this spirit effectively. There is now a greater emphasis on creating a more open culture for teaching and learning and institutions are again beginning to play their part more readily. On a larger scale, there are pioneering global examples of courses being preserved and complex learning materials being deposited in national and international databases. But what does fostering a more open culture in the practice of teaching mean for the institution itself and its academics? The virtual learning environment has given greater opportunities for effective administration of courses but in other ways it has had the opposite effect on sharing and re-use. There is potential for institutional solutions which are complementary to the global landscape. In this paper we report on the practical experiences and issues met, in setting up a institutional resource, EdShare, as a vehicle for sharing educational materials more easily in a multi-disciplinary institution. With constructive feedback from faculty, within the EdSpace project, EdShare has migrated into a more visual, web 2.0 style, resource with a flexible deposit process promoting 'micro-sharing'. It now offers a range of sharing options to support the teaching workflow in an encouraging atmosphere. Other features will support the growing emphasis on multidisciplinary teaching and collaboration - both internally and externally.JIS

Quantized Dispersion of Two-Dimensional Magnetoplasmons Detected by Photoconductivity Spectroscopy

We find that the long-wavelength magnetoplasmon, resistively detected by photoconductivity spectroscopy in high-mobility two-dimensional electron systems, deviates from its well-known semiclassical nature as uncovered in conventional absorption experiments. A clear filling-factor dependent plateau-type dispersion is observed that reveals a so far unknown relation between the magnetoplasmon and the quantum Hall effect.Comment: 5 pages, 3 figure

The impact of the spacecraft system SÄNGER on the composition of the middle atmosphere

A two-dimensional chemical model and physical considerations are used to estimate the impact of the spacecraft system SÄNGER on stratospheric and mesospheric ozone in relation to other spacecraft and other anthropogenic perturbations. Perturbations of middle atmospheric NOy H2O and H2 concentrations, and their impact on the radiative balance of the atmosphere, including contrail formation, are discussed. It is found, that in case of about 24 launches per year the perturbations due to SÄGER are about negligible on a global scale. However, if a SÄGER version would be used for a hypersonic fleet of commercial aircraft a serious ozone depletion is predicted. © 1992 by Wax Planck Society

Bathymetric Artifacts in Sea Beam Data: How to Recognize Them and What Causes Them

Sea Beam multibeam bathymetric data have greatly advanced understanding of the deep seafloor. However, several types of bathymetric artifacts have been identified in Sea Beam\u27s contoured output. Surveys with many overlapping swaths and digital recording on magnetic tape of Sea Beam\u27s 16 acoustic returns made it possible to evaluate actual system performance. The artifacts are not due to the contouring algorithm used. Rather, they result from errors in echo detection and processing. These errors are due to internal factors such as side lobe interference, bottom-tracking gate malfunctions, or external interference from other sound sources (e.g., 3.5 kHz echo sounders or seismic sound sources). Although many artifacts are obviously spurious and would be disregarded, some (particularly the omega effects described in this paper) are more subtle and could mislead the unwary observer. Artifacts observed could be mistaken for volcanic constructs, abyssal hill trends, hydrothermal mounds, slump blocks, or channels and could seriously affect volcanic, tectonic, or sedimentological interpretations. Misinterpretation of these artifacts may result in positioning errors when seafloor bathymetry is used to navigate the ship. Considering these possible geological misinterpretations, a clear understanding of the Sea Beam system\u27s capabilities and limitations is deemed essential