Magnetostratigraphic and Biostratigraphic Synthesis of Ocean Drilling Program Leg 105: Labrador Sea and Baffin Bay

During Ocean Drilling Program (ODP) Leg 105, three sites (Sites 645 through 647) were drilled in Baffin Bay and the Labrador Sea to examine the tectonic evolution and the climatic and oceanic histories of this region. Biostratigraphic and magnetostratigraphic results vary at each site, while stratigraphic resolution depends on the limited abundance of marker species and the completeness of the paleomagnetic record. Because of the paucity of planktonic micro- fossils and the poor paleomagnetic record signatures, stratigraphic determinations at Site 645 often rely on defining minimum temporal constraints on specific samples or stratigraphic intervals. The completed stratigraphy indicates that the sedimentary sequence recovered at Site 645 is early Miocene to Holocene in age. The magnetostratigraphy and biostratigraphies are better defined at Sites 646 and 647 in the Labrador Sea. Site 646 generally contains a well-developed magnetostratigraphy and calcareous microfossil biostratigraphy. This biostratigraphy is based on calcareous nannofossils and planktonic foraminifers typical of the North Atlantic Ocean. Siliceous microfossils are also present at Site 646, but they are restricted to upper Pliocene through Holocene sediments. The strati-graphic sequence recovered at Site 646 is late Miocene to Holocene in age. Based primarily on the calcareous nannofossil stratigraphy, the sequence recovered at Site 647 consists of lower Eocene to lower Oligocene, lower Miocene, upper Miocene, and upper Pliocene through Holocene sediments. Three hiatuses are present in this sequence: the older hiatus separates lower Oligocene sediments from lower Miocene sediments, another hiatus separates lower Miocene sediments from upper Miocene sediments, and the youngest one separates up¬per Miocene from upper Pliocene sediments. A magnetostratigraphy is defined for the interval from the Gauss/Matuyama boundary through the Brunhes (Clement et al., this volume). Both planktonic foraminifers and siliceous micro- fossils have restricted occurrences. Planktonic foraminifers occur in Pliocene and younger sediments, and siliceous microfossils are present in lower Miocene and lower Oligocene sediments. The near-continuous Eocene through lower Oligocene sequence recovered at Site 647 allows the calcareous nannofossils and diatom stratigraphies at this site to act as a Paleogene stratigraphic framework. This framework can be com¬pared with the stratigraphy previously completed for DSDP Site 112

Evolution of the diatoms: insights from fossil, biological and molecular data

Molecular sequence analyses have yielded many important insights into diatom evolution, but there have been few attempts to relate these to the extensive fossil record of diatoms, probably because of unfamiliarity with the data available, which are scattered widely through the geological literature. We review the main features of molecular phylogenies and concentrate on the correspondence between these and the fossil record; we also review the evolution of major morphological, cytological and life cycle characteristics, and possible diatom origins. The first physical remains of diatoms are from the Jurassic, and well-preserved, diverse floras are available from the Lower Cretaceous. Though these are unequivocally identifiable as centric diatoms, none except a possible Stephanopyxis can be unequivocally linked to lineages of extant diatoms, although it is almost certain that members of the Coscinodiscophyceae (radial centrics) and Mediophyceae (polar centrics) were present; some display curious morphological features that hint at an unorthodox cell division mechanism and life cycle. It seems most likely that the earliest diatoms were marine, but recently discovered fossil deposits hint that episodes of terrestrial colonization may have occurred in the Mesozoic, though the main invasion of freshwaters appears to have been delayed until the Cenozoic. By the Upper Cretaceous, many lineages are present that can be convincingly related to extant diatom taxa. Pennate diatoms appear in the late Cretaceous and raphid diatoms in the Palaeocene, though molecular phylogenies imply that raphid diatoms did in fact evolve considerably earlier. Recent evidence shows that diatoms are substantially underclassified at the species level, with many semicryptic or cryptic species to be recognized; however, there is little prospect of being able to discriminate between such taxa in fossil material

Radioimmunotherapy-augmented BEAM chemotherapy vs BEAM alone as the high-dose regimen for autologous stem cell transplantation (ASCT) in relapsed follicular lymphoma (FL): Retrospective study of the EBMT Lymphoma Working Party

Relapse remains the most common cause of treatment failure in patients receiving autologous stem cell transplantation (ASCT) for follicular lymphoma (FL). The aim of this study was to evaluate the effect of adding radioimmunotherapy or rituximab (R) to BEAM (carmustine, etoposide, ara-c, melphalan) high-dose therapy for ASCT in patients with relapsed FL. Using the European Society for Blood and Marrow Transplantation registry, we conducted a cohort comparison of BEAM (n=1973), Zevalin-BEAM (Z-BEAM) (n=207) and R-BEAM (n=179) and also a matched-cohort analysis of BEAM vs Z-BEAM including 282 and 154 patients, respectively. BEAM, Z-BEAM and R-BEAM groups were well balanced for age, time from diagnosis to ASCT and disease status at ASCT. The cumulative incidences of relapse (IR) at 2 years were 34, 34 and 32% for Z-BEAM, R-BEAM and BEAM, respectively. By multivariate analysis, there were no significant differences with Z-BEAM or R-BEAM compared with BEAM for IR, non-relapse mortality, event-free survival or overall survival. With the caveat that the limitations of registry analyses have to be taken into account, this study does not support adding radioimmunotherapy or R to BEAM in ASCT for relapsed FL. However, we cannot rule out the existence a particular subset of patients who could benefit from Z-BEAM conditioning that cannot be identified in our series, and this should be tested in a randomized trial.Bone Marrow Transplantation advance online publication, 22 May 2017; doi:10.1038/bmt.2017.88.</p