Mid-Pleistocene Pozzolanic Volcanic Ash in Ancient Roman Concretes

The hydrated lime-volcanic ash mortars of imperial age concrete construction in Rome owe their extraordinary durability to a specific alteration facies of scoriaceous ash from the Pozzolane Rosse ignimbrite, erupted at 456±3 ka from Alban Hills volcano. Stratigraphic, petrographic, and chemical investigations demonstrate that during the warm, humid period preceding marine isotope stage 11, hydrolytic pedogenesis produced an argillic horizon in Pozzolane Rosse, with thick illuvial clay that had little reactivity with hydrated lime, as shown by mortars from the Forum of Julius Caesar (46 to 44 BC). In the underlying soil horizon, however, translocated halloysite overlies opal and poorly crystalline clay surface coatings. Imperial age mortars, as from the Forum and Markets of Trajan (AD 96 to 115), show strong reactivity of these components, altered scoria groundmass, and zeolites with hydrated lime. Romans deliberately selected this alkali-rich ash for optimal performance of pozzolanic concretes

Major explosive activity in the Monti Sabatini Volcanic District(central Italy) over the 800-390ka interval: Geochronological-geochemical overview and tephrostratigraphic implications

A review of the existing chronological, stratigraphic and chemo-petrologic data of the major eruptive units from the early phase of activity (800-390ka) in the Monti Sabatini Volcanic District (MSVD), belonging to the ultra-potassic magmatic region of central Italy, is presented along with new radioisotopic age determinations and geochemical analyses. Through the combined use of electron microprobe glass compositions, selected trace-element compositions, and single-crystal 40Ar/39Ar age determinations, we provide a new chrono- and chemo-stratigraphic classification of the products emplaced in the 800-390ka time interval. Besides giving insights on the petrologic evolution of the Roman Comagmatic Region, the large dataset provides fundamental information that is applicable to tephrostratigraphic studies in the wide region encompassing the Tyrrhenian Sea margin to the Adriatic Sea basin. Distal tephras from this volcanic activity also act as important geochronologic markers for the coastal sedimentary successions deposited in response to glacio-eustatic fluctuations, as well as for successions in the Quaternary tectonic basins of the Central and Southern Apennines. An innovative approach based on the use of discrimination diagrams of Zr/Y vs Nb/Y ratios for fingerprinting altered volcanic rocks - recently developed and successfully employed in archaeometric studies - is here combined to the glass compositions for classifying the MSVD deposits and tested on two distal tephra layers, showing its potentiality for tephrostratigraphic correlation. © 2014 Elsevier Ltd

Protective effect of stromal Dickkopf-3 in prostate cancer: opposing roles for TGFBI and ECM-1

Aberrant transforming growth factor–β (TGF-β) signaling is a hallmark of the stromal microenvironment in cancer. Dickkopf-3 (Dkk-3), shown to inhibit TGF-β signaling, is downregulated in prostate cancer and upregulated in the stroma in benign prostatic hyperplasia, but the function of stromal Dkk-3 is unclear. Here we show that DKK3 silencing in WPMY-1 prostate stromal cells increases TGF-β signaling activity and that stromal cellconditioned media inhibit prostate cancer cell invasion in a Dkk-3-dependent manner. DKK3 silencing increased the level of the cell-adhesion regulator TGF-β–induced protein (TGFBI) in stromal and epithelial cell-conditioned media, and recombinant TGFBI increased prostate cancer cell invasion. Reduced expression of Dkk-3 in patient tumors was associated with increased expression of TGFBI. DKK3 silencing reduced the level of extracellular matrix protein-1 (ECM-1) in prostate stromal cell-conditioned media but increased it in epithelial cell-conditioned media, and recombinant ECM-1 inhibited TGFBI-induced prostate cancer cell invasion. Increased ECM1 and DKK3 mRNA expression in prostate tumors was associated with increased relapse-free survival. These observations are consistent with a model in which the loss of Dkk-3 in prostate cancer leads to increased secretion of TGFBI and ECM-1, which have tumor-promoting and tumor-protective roles, respectively. Determining how the balance between the opposing roles of extracellular factors influences prostate carcinogenesis will be key to developing therapies that target the tumor microenvironment

Enhanced El Niño‐Southern Oscillation variability in recent decades

The El Nino-Southern Oscillation (ENSO) represents the largest source of year-to-year global climate variability. While Earth system models suggest a range of possible shifts in ENSO properties under continued greenhouse gas forcing, many centuries of preindustrial climate data are required to detect a potential shift in the properties of recent ENSO extremes. Here we reconstruct the strength of ENSO variations over the last 7,000 years with a new ensemble of fossil coral oxygen isotope records from the Line Islands, located in the central equatorial Pacific. The corals document a significant decrease in ENSO variance of similar to 20% from 3,000 to 5,000 years ago, coinciding with changes in spring/fall precessional insolation. We find that ENSO variability over the last five decades is similar to 25% stronger than during the preindustrial. Our results provide empirical support for recent climate model projections showing an intensification of ENSO extremes under greenhouse forcing.Plain Language Summary Recent modeling studies suggest that El Nino will intensify due to greenhouse warming. Here new coral reconstructions of the El Nino-Southern Oscillation (ENSO) record sustained, significant changes in ENSO variability over the last 7,000 years and imply that ENSO extremes of the last 50 years are significantly stronger than those of the preindustrial era in the central tropical Pacific. These records suggest that El Nino events already may be intensifying due to anthropogenic climate change

The Hominin Sites and Paleolakes Drilling Project:High-Resolution Paleoclimate Records from the East African Rift System and Their Implications for Understanding the Environmental Context of Hominin Evolution

The possibility of a causal relationship between Earth history processes and hominin evolution in Africa has been the subject of intensive paleoanthropological research for the last 25 years. One fundamental question is: can any geohistorical processes, in particular, climatic ones, be characterized with sufficient precision to enable temporal correlation with events in hominin evolution and provide support for a possible causal mechanism for evolutionary changes? Previous attempts to link paleoclimate and hominin evolution have centered on evidence from the outcrops where the hominin fossils are found, as understanding whether and how hominin populations responded to habitat change must be examined at the local basinal scale. However, these outcrop records typically provide incomplete, low-resolution climate and environmental histories, and surface weathering often precludes the application of highly sensitive, state-of-the-art paleoenvironmental methods. Continuous and well-preserved deep-sea drill core records have provided an alternative approach to reconstructing the context of hominin evolution, but have been collected at great distances from hominin sites and typically integrate information over vast spatial scales. The goal of the Hominin Sites and Paleolakes Drilling Project (HSPDP) is to analyze climate and other Earth system dynamics using detailed paleoenvironmental data acquired through scientific drilling of lacustrine depocenters at or near six key paleoanthropological sites in Kenya and Ethiopia. This review provides an overview of a unique collaboration of paleoanthropologists and earth scientists who have joined together to explicitly explore key hypotheses linking environmental history and mammalian (including hominin) evolution and potentially develop new testable hypotheses. With a focus on continuous, high-resolution proxies at timescales relevant to both biological and cultural evolution, the HSPDP aims to dramatically expand our understanding of the environmental history of eastern Africa during a significant portion of the Late Neogene and Quaternary, and to generate useful models of long-term environmental dynamics in the regionpublishersversionPeer reviewe

Orbital control of Pleistocene euxinia in Lake Magadi, Kenya

Lake Magadi is an internally drained, saline and alkaline terminal sump in the southern Kenya Rift. Geochemistry of samples from an ∼200 m core representing the past ∼1 m.y. ofthe lake’s history shows some of the highest concentrations of transition metals and metalloidsever reported from lacustrine sediment, including redox-sensitive elements molybdenum,arsenic, and vanadium. Elevated concentrations of these elements represent times when thelake’s hypolimnion was euxinic—that is, anoxic, saline, and sulfide-rich. Euxinia was commonafter ca. 700 ka, and after that tended to occur during intervals of high orbital eccentricity.These were likely times when high-frequency hydrologic changes favored repeatedepisodes of euxinia and sulfide precipitation. High-amplitude environmental fluctuations atpeak eccentricity likely impacted water balance in terrestrial habitats and resource availabilityfor early hominins. These are associated with important events in human evolution,including the first appearance of Middle Stone Age technology between ca

Characterization of a Human Cell Line Stably Over-Expressing the Candidate Oncogene, Dual Specificity Phosphatase 12

Analysis of chromosomal rearrangements within primary tumors has been influential in the identification of novel oncogenes. Identification of the "driver" gene(s) within cancer-derived amplicons is, however, hampered by the fact that most amplicons contain many gene products. Amplification of 1q21-1q23 is strongly associated with liposarcomas and microarray-based comparative genomic hybridization narrowed down the likely candidate oncogenes to two: the activating transcription factor 6 (atf6) and the dual specificity phosphatase 12 (dusp12). While atf6 is an established transcriptional regulator of the unfolded protein response, the potential role of dusp12 in cancer remains uncharacterized.To evaluate the oncogenic potential of dusp12, we established stable cell lines that ectopically over-express dusp12 in isolation and determined whether this cell line acquired properties frequently associated with transformed cells. Here, we demonstrate that cells over-expressing dusp12 display increased cell motility and resistance to apoptosis. Additionally, over-expression of dusp12 promoted increased expression of the c-met proto-oncogene and the collagen and laminin receptor intergrin alpha 1 (itga1) which is implicated in metastasis.Collectively, these results suggest that dusp12 is oncologically relevant and exposes a potential association between dusp12 and established oncogenes that could be therapeutically targeted

TEAD1 and c-Cbl are novel prostate basal cell markers that correlate with poor clinical outcome in prostate cancer

Prostate cancer is the most frequently diagnosed male cancer, and its clinical outcome is difficult to predict. The disease may involve the inappropriate expression of genes that normally control the proliferation of epithelial cells in the basal layer and their differentiation into luminal cells. Our aim was to identify novel basal cell markers and assess their prognostic and functional significance in prostate cancer. RNA from basal and luminal cells isolated from benign tissue by immunoguided laser-capture microdissection was subjected to expression profiling. We identified 112 and 267 genes defining basal and luminal populations, respectively. The transcription factor TEAD1 and the ubiquitin ligase c-Cbl were identified as novel basal cell markers. Knockdown of either marker using siRNA in prostate cell lines led to decreased cell growth in PC3 and disrupted acinar formation in a 3D culture system of RWPE1. Analyses of prostate cancer tissue microarray staining established that increased protein levels of either marker were associated with decreased patient survival independent of other clinicopathological metrics. These data are consistent with basal features impacting on the development and clinical course of prostate cancers

The Hominin Sites and Paleolakes Drilling Project:Inferring the environmental context of human evolution from eastern African rift lake deposits

Funding for the HSPDP has been provided by ICDP, NSF (grants EAR-1123942, BCS-1241859, and EAR-1338553), NERC (grant NE/K014560/1), DFG priority program SPP 1006, DFG-CRC-806 “Our way to Europe”, the University of Cologne (Germany), the Hong Kong Research Grants Council (grant no. HKBU201912), the Peter Buck Fund for Human Origins Research (Smithsonian), the William H. Donner Foundation, the Ruth and Vernon Taylor Foundation, Whitney and Betty MacMillan, and the Smithsonian’s Human Origins Program.The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012–2014 HSPDP coring campaign.Publisher PDFPeer reviewe

Probing the Interstellar Medium in Early type galaxies with ISO observations

Four IRAS-detected early type galaxies were observed with ISO. With the exception of the 15 micron image of NGC1052, the mid-IR emission from NGC1052, NGC1155, NGC5866 and NGC6958 at 4.5, 7 and 15 microns show extended emission. Mid-IR emission from NGC1052, NGC1155, and NGC6958 follows a de Vaucouleurs profile. The ratio of 15/7 micron flux decreases with radius in these galaxies, approaching the values empirically observed for purely stellar systems. In NGC5866, the 7 and 15 micron emission is concentrated in the edge-on dust lane. All the galaxies are detected in the [CII] line, and the S0s NGC1155 and NGC5866 are detected in the [OI] line as well. The ISO-LWS observations of the [CII] line are more sensitive measures of cool, neutral ISM than HI and CO by about a factor of 10-100. Three of four early type galaxies, namely NGC1052, NGC6958 and NGC5866, have low ratio FIR/Blue and show a lower [CII]/FIR, which is due to a softer radiation field from old stellar populations. The low [CII]/CO ratio in NGC5866 ([CII]/CO(1-0) < 570) confirms this scenario. We estimate the UV radiation expected from the old stellar populations in these galaxies and compare it to that needed to heat the gas to account for the cooling observed [CII] and [OI] lines. In three out of four galaxies, NGC1052, NGC5866 and NGC6958, the predicted UV radiation falls short by a factor of 2-3. In view of the observed intrinsic scatter in the "UV-upturn" in elliptical galaxies and its great sensitivity to age and metallicity effects, this is not significant. However, the much larger difference (about a factor of 20) between the UV radiation from old stars and that needed to produce the FIR lines for NGC 1155 is strong evidence for the presence of young stars, in NGC1155.Comment: To appear in the Astrophysical Journal. Figure 1 appears as a separate jpg figur