253puse of red clover in premenopausal breast cancer patients receiving hormonal adjuvant treatment biological and clinical implications from a randomized clinical trial

n/

The RNA Helicase DDX6 Controls Cellular Plasticity by Modulating P-Body Homeostasis

Post-transcriptional mechanisms have the potential to influence complex changes in gene expression, yet their role in cell fate transitions remains largely unexplored. Here, we show that suppression of the RNA helicase DDX6 endows human and mouse primed embryonic stem cells (ESCs) with a differentiation-resistant, “hyper-pluripotent” state, which readily reprograms to a naive state resembling the preimplantation embryo. We further demonstrate that DDX6 plays a key role in adult progenitors where it controls the balance between self-renewal and differentiation in a context-dependent manner. Mechanistically, DDX6 mediates the translational suppression of target mRNAs in P-bodies. Upon loss of DDX6 activity, P-bodies dissolve and release mRNAs encoding fate-instructive transcription and chromatin factors that re-enter the ribosome pool. Increased translation of these targets impacts cell fate by rewiring the enhancer, heterochromatin, and DNA methylation landscapes of undifferentiated cell types. Collectively, our data establish a link between P-body homeostasis, chromatin organization, and stem cell potency

Major factors controlling Late Pleistocene to Holocene soil development in the Vesuvius area (southern Italy)

In this paper the role of time and late Pleistocene to middle Holocene climate changes in the Somma-Vesuvius volcano foothill (southern Italy) is investigated with a multidisciplinary approach. Four volcanic soils inter-layered between five well-known and well-dated primary tephra layers were characterized. Chronological constraints were provided by the pyroclastic layers identified in the field (Pomici di Base, Pomici Verdoline, Agnano Pomici Principali, Mercato and Avellino), ranging between 22 and 3.8 thousand years (ka) before present (BP). These represent products of explosive eruptions of Somma-Vesuvius and the Phlegrean Fields. Another pyroclastic layer (Agnano Monte Spina) from the Phlegrean Fields was also identified, and other ash layers previously unknown in the Somma-Vesuvius stratigraphy. These were characterized with SEM-EDS analyses, and correlated with other eruptions from the Phlegrean Fields (Soccavo 4-5 and Tufi Biancastri) around 12 and 21 ka BP, respectively, thus resulting in further time constraints for phases of soil development. A detailed characterization of the four pedons integrated morphological, physical, chemical, mineralogical and micromorphological analyses. Soil features were interpreted in terms of dominant genetic processes and environmental conditions. The extent of soil development, assessed with pedogenetic indices and the degree of weathering of primary pumices, was only in part consistent with time-spans of soil formation, suggesting a more important role of climate than soil age. The different extents of expression of andic properties, pumice weathering and varying clay mineralogy allowed us to relate changes to the main climatic phases that occurred during the late Pleistocene to the mid Holocene. © 2014 British Society of Soil Science

Soil genesis, morphodynamic processes and chronological implications in two soil transects of SE Sardinia, Italy: Traditional pedological study coupled with laser ablation ICP-MS and radionuclide analyses

Soils are characterized by an intrinsic variability through time and space at different scales of observation and are often affected by morphodynamic processes strictly interacting with pedogenesis, under changing (paleo) environmental/climatic conditions. We focus on exploring this interplay in modern soils and paleosols of southeast Sardinia (Italy), integrating two innovative techniques to a traditional pedological study: (i) laser ablation ICP-MS spot analyses applied to detect microscale distribution of trace elements in discrete soil features of organic-mineral (A) and argillic (Bt) horizons in thin section, and (ii) radioactive disequilibria as tracers and chronometers of pedogenetic alteration and geomorphic dynamics. The Pleistocene paleosols developed mainly during interglacial periods, with important clay illuviation and rubification. The other soils are essentially characterized by organic matter incorporation into the profiles. Field discontinuities described within soil profiles, related to phases of sediment aggradation and/or surface erosion, are often supported by laboratory results, mainly micromorphological and geochemical data. LA-ICP-MS data show an overall trend of increase of most trace elements (REEs included) from skeletal rock fragments to both clayey and organic-rich soil matrix to clay coatings. This pathway is clearly controlled by the degree of weathering of primary minerals and by pedogenetic processes, where element adsorption onto reactive sites of organic matter and clay particles and clay illuviation play prominent roles. Recent trends of the studied soils/paleosols in terms of geomorphic stability (equilibrium) or morphodynamic processes (erosion/accumulation rates) are estimated using radionuclide disequilibria in the order of 1 cm/a or lower