Cutting edge: thymic crosstalk regulates delta-like 4 expression on cortical epithelial cells.

Interactions between Notch1 receptors on lymphoid progenitors and Delta-like 4 (DL4) ligands on cortical thymic epithelial cells (cTEC) are essential for T cell lineage commitment, expansion, and maturation in the thymus. Using a novel mAb against DL4, we show that DL4 levels on cTEC are very high in the fetal and neonatal thymus when thymocyte expansion is maximal but decrease dramatically in the adult when steady-state homeostasis is attained. Analysis of mutant mouse strains where thymocyte development is blocked at different stages indicates that lymphostromal interactions ("thymus crosstalk") are required for DL4 down-regulation on cTEC. Reconstitution of thymocyte development in these mutant mice further suggests that maturation of thymocytes to the CD4(+)CD8(+) stage and concomitant expansion are needed to promote DL4 down-regulation on cTEC. Collectively, our data support a model where thymic crosstalk quantitatively regulates the rate of Notch1-dependent thymopoiesis by controlling DL4 expression levels on cTEC.

Cutting edge: a novel viral TNF receptor superfamily member in virulent strains of human cytomegalovirus.

The UL144 open reading frame found in clinical isolates of human CMV (HCMV) encodes a structural homologue of the herpesvirus entry mediator, a member of the TNFR superfamily. UL144 is a type I transmembrane glycoprotein that is expressed early after infection of fibroblasts; however, it is retained intracellularly. A YXXZ motif in the highly conserved cytoplasmic tail contributes to UL144 subcellular distribution. The finding that no known ligand of the TNF family binds UL144 suggests that its mechanism of action is distinct from other known viral immune evasion genes. Specific Abs to UL144 can be detected in the serum of a subset of HCMV seropositive individuals infected with HIV. This work establishes a novel molecular link between the TNF superfamily and herpesvirus that may contribute to the ability of HCMV to escape immune clearance.

Termination of major ductile strike-slip shear and differential cooling along the Insubric line (Central Alps): U-Pb, Rb-Sr and 40Ar/39Ar ages of cross-cutting pegmatites

To constrain the age of strike-slip shear, related granitic magmatism, and cooling along the Insubric line, 29 size fractions of monazite and xenotime were dated by the U-Pb method, and a series of 25 Rb-Sr and Ar-40/Ar-39 ages were measured on different size fractions of muscovite and biotite. The three pegmatitic intrusions analyzed truncate high-grade metamorphic mylonite gneisses of the Simplon shear zone, a major Alpine structure produced in association with dextral strike-slip movements along the southern edge of the European plate, after collision with its Adriatic indenter. Pegmatites and aplites were produced between 29 and 25 Ma in direct relation to right-lateral shear along the Insubric line, by melting of continental crust having Sr-87/Sr-86 between 0.7199 and 0.7244 at the time of melting. High-temperature dextral strike-slip shear was active at 29.2 +/- 0.2 (2 sigma) Ma, and it terminated before 26.4 +/- 0.1 Ma. During dike injection, temperatures in the country rocks of the Isorno-Orselina and Monte Rosa structural units did not exceed approximate to 500 degrees C, leading to fast initial cooling, followed by slower cooling to approximate to 350 degrees C within several million years. In one case, initial cooling to approximate to 500 degrees C was significantly delayed by about 4 m.y., with final cooling to approximate to 300 degrees C at 20-19 Ma in all units. For the period between 29 and 19 Ma, cooling of the three sample localities was non-uniform in space and time, with significant variations on the kilometre scale. These differences are most likely due to strongly varying heat flow, and/or heterogeneous distribution of unroofing rates within the continuously deforming Insubric line. If entirely ascribed to differences in unroofing, corresponding rates would vary between 0.5 and 2.5 mm/y, for a thermal gradient of 30 degrees/km.

Syntaxonomic conspectus of the vegetation of Catalonia and Andorra. I: Hygrophilous herbaceous communities.

The first part of a general survey of the vegetation of Catalonia andAndorra, this paper reports all the phytocoenological associations and subassociations recorded in this area. For each community, we provide the correct name and usual synonyms, its typification (where appropriate), all the references including relevés, and the most outstanding features of its structure, species composition, ecology, distribution and diversity. Moreover, associations and subassociations are ordered appropriately in a syntaxonomic scheme. Syntaxonomic ranks are considered in a fairly broad, conservative sense. This classification established 101 associations, which correspond to the classes Lemnetea, Zosteretea, Potametea, Littorelletea, Montio-Cardaminetea, Phragmiti-Magnocaricetea, Scheuchzerio-Caricetea, Isoeto-Nanojuncetea and Molinio-Arrhenatheretea.

Effect of soil-water tension on herbaceous cotton yield

A field experiment was conducted during two years, 1990/91, in an alluvial soil, in the State of Paraíba, Brazil, to study the effect of the levels of soil-water tension, 50, 100, 200, 300, 400 and 600 kPa, at 20 cm depth, on upland cotton (Gossypium hirsutum L.r. latifolium Hutch, cv. CNPA-6H) yield. The experimental design was a complete randomized block with six treatments and four repetitions. There was an effect of the treatments on plant height, leaf area index and cotton yield, but the precocity index was not modified. Water should be applied when the soil-water tension, measured at 20 cm depth, reaches values around 200 kPa. There was a quadratic (R² = 0.893**) response of cotton yields to soil water tension, with the maximum when water was applied at 52% of soil water depletion.

Lihahygienialainsäädännön omavalvontasäädökset ja käytäntö Oy Snellman Ab:n teurastamossa ja leikkaamossa, osa I Osa 1 : Owncontrol directions in meat hygiene legislation and their practical implementation in the slaughterhouse and cutting plant of Snellman Ltd, part I

Summary: Owncontrol directions in meat hygiene legislation and their practical implementation in the slaughterhouse and cutting plant of Snellman Ltd, part I

Export of dissolved organic carbon, nitrogen and phosphorus following clear-cutting of three Norway spruce forest growing on drained peatlands in southern Finland

Abstract

Cutting edge: cell autonomous rather than environmental factors control bacterial superantigen-induced T cell anergy in vivo.

Anergic T cells display a marked decrease in their ability to produce IL-2 and to proliferate in the presence of an appropriate antigenic signal. Two nonmutually exclusive classes of models have been proposed to explain the persistence of T cell anergy in vivo. While some reports indicate that anergic T cells have intrinsic defects in signaling pathways or transcriptional activities, other studies suggest that anergy is maintained by environmental "suppressor" factors such as cytokines or Abs. To distinguish between these conflicting hypotheses, we employed the well-characterized bacterial superantigen model system to evaluate in vivo the ability of a trace population of adoptively transferred naive or anergized T cells to proliferate in a naive vs anergic environment upon subsequent challenge. Our data clearly demonstrate that bacterial superantigen-induced T cell anergy is cell autonomous and independent of environmental factors.

Phosphorus analysis in soil under herbaceous perennial leguminous cover by nuclear magnetic spectroscopy

The availability and the reserves of organic phosphorus are controlled by its mineralization rate and are also influenced by changes in soil management. The objective of this study was to evaluate the influence of soil covering with different leguminous plant on soil organic P by 31P-NMR spectroscopy. Alkaline soil extracts were obtained from two depths (0-5 and 5-10 cm) of an Ultisol cultivated with herbaceous perennial leguminous plants (Arachis pintoi, Pueraria phaseoloides, Macroptilium atropurpureum). In an adjacent area, samples of the same soil cover with a secondary tropical forest and grass (Panicum maximum) were also collected. The leguminous management was divided into with removal and without removal of shoot parts after cut on soil surface. Phosphate monoesters are the dominant P species in all soil samples and P diesters accumulated on the superficial layer of secondary forest soil. The P amount of this fraction is higher for the legume covered soil when compared with the grass covered soil. The permanence of leguminous plants on the topsoil after the cut promoted an increase in P diester/P monoester ratios. These findings can be accounted for an enhancement of P availability to plants in soils cultivated with leguminous plants.

Automation of DEM Cutting for Hydrologic/Hydraulic Modeling, TR-631, 2015

Hydrologic analysis is a critical part of transportation design because it helps ensure that hydraulic structures are able to accommodate the flow regimes they are likely to see. This analysis is currently conducted using computer simulations of water flow patterns, and continuing developments in elevation survey techniques result in higher and higher resolution surveys. Current survey techniques now resolve many natural and anthropogenic features that were not practical to map and, thus, require new methods for dealing with depressions and flow discontinuities. A method for depressional analysis is proposed that uses the fact that most anthropogenically constructed embankments are roughly more symmetrical with greater slopes than natural depressions. An enforcement method for draining depressions is then analyzed on those depressions that should be drained. This procedure has been evaluated on a small watershed in central Iowa, Walnut Creek of the South Skunk River, HUC12 # 070801050901, and was found to accurately identify 88 of 92 drained depressions and place enforcements within two pixels, although the method often tries to drain prairie pothole depressions that are bisected by anthropogenic features.

Degree of previous cutting in explaining the differences in diameter distributions between mature managed and natural Norway spruce forests

Abstract

Comparison of Setting Time Measured Using Ultrasonic Wave Propagation with Saw-Cutting Times on Pavements, TR-675, 2015

At present, there is little fundamental guidance available to assist contractors in choosing when to schedule saw cuts on joints. To conduct pavement finishing and sawing activities effectively, however, contractors need to know when a concrete mixture is going to reach initial set, or when the sawing window will open. Previous research investigated the use of the ultrasonic pulse velocity (UPV) method to predict the saw-cutting window for early entry sawing. The results indicated that the method has the potential to provide effective guidance to contractors as to when to conduct early entry sawing. The aim of this project was to conduct similar work to observe the correlation between initial setting and conventional sawing time. Sixteen construction sites were visited in Minnesota and Missouri over a two-year period. At each site, initial set was determined using a p-wave propagation technique with a commercial device. Calorimetric data were collected using a commercial semi-adiabatic device at a majority of the sites. Concrete samples were collected in front of the paver and tested using both methods with equipment that was set up next to the pavement during paving. The data collected revealed that the UPV method looks promising for early entry and conventional sawing in the field, both early entry and conventional sawing times can be predicted for the range of mixtures tested.