Evidence for clonal selection of gamma/delta T cells in response to a human pathogen.

T cells bearing gamma/delta antigen receptors comprise a resident population of intraepithelial lymphocytes in organs such as skin, gut, and lungs, where they are strategically located to contribute to the initial defense against infection. An important unsolved question about antigen-driven gamma/delta T cell responses regards the breadth of their T cell receptor (TCR) repertoire, since many specific epithelial compartments in mice display limited diversity. We have examined the diversity of TCR delta gene expression among human gamma/delta T cells from skin lesions induced by intradermal challenge with Mycobacterium leprae. We show that the vast majority of gamma/delta cells from M. leprae lesions use either V delta 1-J delta 1 or V delta 2-J delta 1 gene rearrangements and, within a given region of the lesion, display limited junctional diversity. This contrasts markedly with the extensive diversity of gamma/delta T cells from peripheral blood of these same individuals, as well as skin from normal donors. These results indicate that the gamma/delta response to M. leprae involves the selection of a limited number of clones from among a diverse repertoire, probably in response to specific mycobacterial and/or host antigens

IODP Proposal 626: "Cenozoic Equatorial Age Transect – Following the Palaeo-equator"

As the largest ocean, the Pacific is intricately linked to major changes in the global climate system that took place during the Cenozoic. Throughout the Cenozoic the Pacific plate has had a northward component. Thus, the Pacific is unique, in that the thick sediment bulge of biogenic rich deposits from the currently narrowly focused zone of equatorial upwelling is slowly moving away from the equator. Hence, older sections are not deeply buried and can be recovered by drilling. Previous ODP Legs 138 and 199 were designed as transects across the paleo-equator in order to study the changing patterns of sediment deposition across equatorial regions, while this proposal aims to recover an orthogonal “age-transect” along the paleo-equator. Both previous legs were remarkably successful in giving us new insights into the workings of the climate and carbon system, productivity changes across the zone of divergence, time dependent calcium carbonate dissolution, bio- and magnetostratigraphy, the location of the ITCZ, and evolutionary patterns for times of climatic change and upheaval. Together with older DSDP drilling in the eastern equatorial Pacific, both Legs also helped to delineate the position of the paleo-equator and variations in sediment thickness from approximately 150°W to 110°W. As we have gained more information about the past movement of plates, and where in time “critical” climate events are located, we now propose to drill an age-transect (“flow-line”) along the position of the paleo-equator in the Pacific, targeting selected time-slices of interest where calcareous sediments have been preserved best. Leg 199 enhanced our understanding of extreme changes of the calcium carbonate compensation depth across major geological boundaries during the last 55 million years. A very shallow CCD during most of the Paleogene makes it difficult to obtain well preserved sediments, but we believe our siting strategy will allow us to drill the most promising sites and to obtain a unique sedimentary biogenic carbonate archive for time periods just after the Paleocene- Eocene boundary event, the Eocene cooling, the Eocene/Oligocene transition, the “one cold pole” Oligocene, the Oligocene-Miocene transition, and the Miocene, contributing to the objectives of the IODP Extreme Climates Initiative, and providing material that the previous legs were not able to recover

Comparative assessment of young learners' foreign language competence in three Eastern European countries

This paper concerns teacher practices in, and beliefs about, the assessment of young learners' progress in English in three Eastern European countries (Slovenia, Croatia, and the Czech Republic). The central part of the paper focuses on an international project involving empirical research into assessment of young learners' foreign language competence in Slovenia, Croatia and the Czech Republic. With the help of an adapted questionnaire, we collected data from a non-random sample of primary and foreign language teachers who teach foreign languages at the primary level in these countries. The research shows that English as a foreign language is taught mostly by young teachers either primary specialists or foreign language teachers. These teachers most frequently use oral assessment/interviews or self-developed tests. Other more authentic types of assessment, such as language portfolios, are rarely used. The teachers most frequently assess speaking and listening skills, and they use assessment involving vocabulary the most frequently of all. However, there are significant differences in practice among the three countries

Effectiveness evaluation of STOL transport operations

A short-takeoff and landing (STOL) systems simulation model has been developed and implemented in a computer code (known as STOL OPS) which permits evaluation of the operation of a STOL aircraft and its avionics in a commercial airline operating environment. STOL OPS concentrated on the avionics functions of navigation, guidance, control, communication, hazard aviodance, and systems management. External world factors influencing the operation of the STOL aircraft include each airport and its geometry, air traffic at each airport, air traffic control equipment and procedures, weather (including winds and visibility), and the flight path between each airport served by the route. The development of the STOL OPS program provides NASA a set of computer programs which can be used for detailed analysis of a STOL aircraft and its avionics and permit establishment of system requirements as a function of airline mission performance goals

Studies of factors affecting performance of growing-finishing lambs

This bulletin is a report on Department of Animal Husbandry Research Project 356, 'Lamb fattening'--P. [3].Digitized 2007 AES.Includes bibliographical references (pages 61-65)

Site 1220

Site 1220 (10°10.600´N, 142°45.503´W; 5218 meters below sea level (mbsl); Fig. F1) forms a southerly component of the 56-Ma transect drilled during Leg 199. It is situated about midway between the Clipperton and Clarion Fracture Zones in typical abyssal hill topography. On the basis of regional magnetic anomalies, we anticipated basement age at Site 1220 to be equivalent to Chron C25n (~56 Ma; Cande et al., 1989), slightly older than at Site 1219. At the outset of drilling at Site 1220, our estimate for total sediment depth was ~225 meters below seafloor (mbsf) (Fig. F2). Based upon a fixed hotspot model (Gripp and Gordon, 1990, for 0- to 5-Ma Pacific hotspot rotation pole; Engebretson et al., 1985, for older poles), Site 1220 should have been located ~3° south of the equator at 56 Ma and in an equatorial position at 40 Ma. Thus, Site 1220 should have been situated underneath the South Equatorial Current in the early Eocene. A nearby piston core (EW9709-13PC) taken during the site survey cruise recovered >16 m of red clay, with the base of the core dated as middle-early Miocene on the basis of radiolarian biostratigraphy (Lyle, 2000). Site 1220 will be used to study equatorial ocean circulation from the late Paleocene through the late Eocene during the early Cenozoic thermal maximum. Sediment records from this site will help to define the calcite compensation depth (CCD) and lysocline during the Paleocene-Eocene and Eocene-Oligocene transitions. In this and other respects, Site 1220 will act as an interesting analog to Site 1218. Both sites are thought to have been located on the equator at ~40 Ma, but the older crustal age anticipated at Site 1220 dictates a greater paleowater depth than for contemporaneous sediments accumulating at Site 1218

Site 1216

Site 1216 (21°27.16´N, 139°28.79´W; 5152 meters below sea level [mbsl]; Fig. F1) is situated in abyssal hill topography south of the Molokai Fracture Zone and two small associated unnamed parasitic fracture zones (Fig. F2). Based on magnetic lineations, Site 1216 appears to be situated on normal ocean crust formed during the C25r magnetic anomaly (~57 Ma; Atwater and Severinghaus, 1989). Site 1216 was chosen for drilling because it is near the thickest section of lower Eocene sediments along the 56-Ma transect, which was based upon the seismic stratigraphy of seismic reflection data acquired on site survey cruise EW9709 during transits between the proposed drill sites (Lyle et al., this volume; Moore et al., 2002). The Cenozoic history of sedimentation in this region was poorly constrained prior to Leg 199, being largely based on two Deep Sea Drilling Project (DSDP) drill sites (40 and 41) and piston core data (EW9709-3PC) from ~1.5° in latitude to the south. Based on data from these drill sites, we expected the sedimentary sequence at Site 1216 to comprise red clays (a mixture of wind-blown dust and authigenic precipitates) overlying a biogenic sediment section composed of an upper middle Eocene radiolarian ooze and lower carbonate ooze deposited when the site was near the ridge crest in the late Paleocene and early Eocene. The broad paleoceanographic objectives of drilling the sedimentary sequence anticipated at Site 1216 are as follows: (1) to help define the shift in the Intertropical Convergence Zone through the Paleogene by following the change in eolian-dust composition and flux through time (red clays) and (2) to help define the latitudinal extent, composition, and mass accumulation of plankton communities in the north equatorial Pacific region thereby constraining ocean circulation patterns and the extent of the equatorial high-productivity belt in the Eocene ocean. Results from Site 1216 will also provide important information to test whether there was significant motion of the Hawaiian hotspot with respect to the Earth's spin axis during the early Cenozoic. At 56 Ma, the backtracked location of Site 1216 based upon a hotspot reference frame (Gripp and Gordon, 1990, for 0- to 5-Ma Pacific hotspot rotation pole; Engebretson et al., 1985, for older poles) is about 9°N, 108°W. If significant hotspot motion or true polar wander occurred since 57 Ma (Petronotis et al., 1994), this drill site could have been much nearer to the equator

Site 1222

Site 1222 (13°48.98´N, 143°53.35´W; 4989 meters below sea level [mbsl]; Fig. F1) forms a south-central component of the 56-Ma transect drilled during Leg 199 and is situated ~2° south of the Clarion Fracture Zone in typical abyssal hill topography. On the basis of regional magnetic anomalies, we anticipated basement age at Site 1222 to be equivalent to Chron C25r or Chron C25n (~56-57 Ma) (Cande et al., 1989), which is slightly older than at Site 1219. At the outset of drilling at Site 1222, our estimate for total sediment thickness was ~115 m (Fig. F2). Based upon a fixed hotspot model (Gripp and Gordon, 1990, for 0- to 5-Ma Pacific hotspot rotation pole; Engebretson et al., 1985, for older poles) Site 1222 should have been located ~1° north of the equator at 56 Ma and ~4°N at 40 Ma. A nearby gravity core (EW9709-17GC), taken during the site survey cruise, recovered >5 m of red clay with a late-middle Miocene age on the basis of radiolarian biostratigraphy (Lyle, 2000). Deep Sea Drilling Project (DSDP) Site 42 located ~4° east of Site 1222, was not drilled to basement but contains a thin sedimentary section (~100 m thick) of upper Oligocene nannofossil ooze through middle Eocene radiolarian nannofossil ooze. In turn, DSDP Site 162 lies ~1° north of DSDP Site 42 and is situated on young crust (49 Ma) that contains ~150 m of clayey radiolarian and nannofossil oozes of early Oligocene-middle Eocene age. Site 1222 will be used to study the position of the Intertropical Convergence Zone in the late Eocene and Oligocene, to sample late Paleocene and early Eocene sediments in the central tropical Pacific Ocean, and to help determine whether or not there has been significant southward movement of the hotspots with respect to the spin axis prior to 40 Ma