The rate of sediment supply from erosional catchment to depositional basin depends primarily upon climate, relief, catchment slope and lithology. It varies in both time and space. Spatial changes in erosion rates due to variations in lithology are illustrated by contrasting rates of drainage divide migration away from faults of known ages. Time variations in relative sediment supply are extremely complex and vary widely according to the direction and magnitude of climate change. In many parts of the Great Basin and south-western USA, glacial maximum climates were characterized by higher effective moisture and the altitudinal downward spread of woods and forests. Sparse data from alluvial fans indicate reduced sediment supply, despite the increased runoff evident from higher lake levels. The situation in Mediterranean areas is less clear, with rival climatic scenarios for vegetation ecotypes predicting contrasting runoff. In order to test these latter we run Cumulative Seasonal Erosion Potential [CSEP] experiments for present-day and a variety of full-glacial Mediterranean candidate climates. The results indicate the likelihood of enhanced sediment supply and runoff compared to the present day during full-glacial times for a cool wet winter climate and a reduction in sediment supply and runoff for a full-glacial cool dry winter climate. We then explore the consequences of such phase differences in sediment supply, and sea and lake levels for the stratigraphy of sedimentary basins. Highstands and lowstands of sea or lake may be accompanied by greater or lesser sediment and water supply, as determined by the regional climate and the direction of climatic change. Thus marine lowstands are not necessarily periods of great transfer of coarse clastic sediments to shelves and deep water basinal environments. Unsteady sediment supply has greatest implications for alluvial systems, in particular the effect that changing relative supplies of water and sediment have upon river and fan channel incision. basin-bordering catchments, minus any sediment stored

Background Acute lymphoblastic leukemia (ALL) accounts for almost one quarter of pediatric cancer in the United States. Despite cooperative group therapeutic trials, there remains a paucity of large cohort data on which to conduct epidemiology and comparative effectiveness research studies. Research Design We designed a three-step process utilizing ICD-9 discharge diagnoses codes and chemotherapy exposure data contained in the Pediatric Health Information System administrative database to establish a cohort of children with de novo ALL. This process was validated by chart review at one of the pediatric centers. Results An ALL cohort of 8,733 patients was identified with a sensitivity of 88% (95% CI: 83–92%) and a positive predictive value of 93% (95% CI: 89–96%). The 30-day all cause inpatient case fatality rate using this three-step process was 0.80% (95% CI: 0.63–1.01%), which was significantly different than the case fatality rate of 1.40% (95% CI: 1.23–1.60%) when ICD-9 codes alone were used. Conclusions This is the first report of assembly and validation of a cohort of de novo ALL patients from a database representative of free standing children's hospitals across the United States. Our data demonstrate that the use of ICD-9 codes alone to establish cohorts will lead to substantial patient misclassification and result in biased outcome estimates. Systematic methods beyond the use of just ICD-9 codes must be employed prior to analysis to establish accurate cohorts of patients with malignancy. A similar approach should be followed when establishing future cohorts from administrative data.

The direct demonstration by McMaster and Hudack (1) of the production of antibody in lymph nodes led to a long search for the cell in the lymph node which synthesized antibody. Early evidence by Harris, Grimm, Mertens, and Ehrich (2), Dougherty, Chase, and White (3), and Harris and Harris (4) that the lymphocyte was the cell of synthesis was followed by the studies of BjSrnehoe and Gormsen (5), and Fagraeus (6) indicating the plasma cell as the cell which produced antibody. The following years produced studies of the cellular source of antibody by at least six experimental approaches, each of which led some authors to conclude that the plasmacytic series of cells was involved, and others, the lymphocytic series (7).The culmination, in 1955, of this decade and a half of intensive research was the actual finding of antibody within plasma cells, by Coons and his colleagues (8-10), using the indirect fluorescent antibody technique. These cells were found in antibody-producing lymph nodes; antibody-containing plasma cells were soon also found in other situations, i.e., in sites of deposition of transferred lymph node cells, by Dixon and his colleagues (11-13), and in chambers containing antigen-stimulated lymph node cells, by several groups of workers (14-16). Also supporting this association was the observation of Nossal (17), in single cell preparations from active lymph nodes, that virtually all the cells which were identified as antibody-producing were plasma cells.More recently, however, a number of reported observations have again given direct evidence of a role of the lymphocyte in antibody formation. In single cell droplet studies which involved a more sensitive antibody assay than that of Nossal (17), Attardi, Cohn, Horibata, and Lennox (18) found lymphocytes among the antibody-forming cells, the frequency of antibody-producing cells among the lymphocytes found being roughly one-third that found among plasma cells. Balfour, Cooper, and Alpen (19) found, after a secondary injection of diphtheria toxoid, that of the cells in the regional lymph node

Typhoid vaccine and sheep erythrocytes were injected subcutaneously into the feet of rabbits, and the subsequent formation of agglutinins and hemolysins in the popliteal lymph node was compared with the output of lymphocytes through the efferent lymph and with changes in the lymph node. Antibodies began to appear in the efferent lymph 2 to 4 days after the injection of the antigen and reached their highest titer after 6 days. This was preceded by a sharp rise in the output of lymphocytes through the efferent lymph, while in the lymph node there was lymphatic hyperplasia after preliminary infiltration of granulocytes and monocytes. This hyperplasia was first of a diffuse type, but was later superseded by large so called germinal centers, the latter lagging somewhat behind the rise in antibody titer. The fact that the tissue response accompanying the formation of antibodies was chiefly a lymphocytic one points to the lymphocyte as a factor in the formation of antibodies.