2,630 research outputs found
Sedimentary evidence relating to the tectonic evolution of the Lau Basin, SW Pacific, from ODP Sites 834-839 (ODP Leg 135)
No full textSix sites were drilled during Ocean Drilling Program Leg 135 in the western Lau backarc basin in the southwest Pacific (Sites 834–839). These sites are all located in basins within a horst and graben terrain and form an approximate transect across the rifted arc basement onto crust considered to have been formed at the East Lau Spreading Centre. The sedimentary sequences recovered from these backarc sites range in age from the late Miocene to the Holocene; they consist primarily of a lower succession of volcaniclastic sediment gravity-flow deposits interbedded with hemipelagic clayey nannofossil oozes and nannofossil clays, overlain by a distinctive upper succession of hydrothermally stained hemipelagic, and locally redeposited, clayey nannofossil oozes. The volcaniclastic sediment gravity-flow deposits are predominantly massive, proximal, vitric gravels, sands and silts, that are mainly locally derived from adjacent basement ridges and intrabasin seamount volcanoes.
At Site 835, which was drilled in a small extensional sub-basin in the oldest part of the Lau Basin, the upper clayey nannofossil ooze sequence is anomalously thick and rigorous sedimentological analysis shows that much of this sequence is redeposited. Thick clayey nannofossil ooze turbidite muds are identified that closely resemble the enclosing clayey nannofossil ooze hemipelagites. These thick turbidite muds are associated with mudclast conglomerates, interpreted as muddy debris-flow deposits, and a number of coherent rafted blocks of older hemipelagic sediment. These allochthonous deposits testify to several episodes of instability in the sub-basin that may be related to large-scale tectonic activity caused by the southward passage of ocean-ridge propagator tips past the latitude of the drillsite. Episodes of increased sediment deposition, due to increased frequency of turbidite emplacement, are evident at all of the Lau Basin backarc drillsites, and these correlate moderately well with the closest approach of the propagating ridge tip to each sub-basin. The research presented illustrates how turbidites, once identified, can be used to decipher complex tectonic histories, and demonstrates the importance of local tectonic controls on sediment redeposition in backarc basins
Sedimentation on basin plains
No full textDeep sea basin plains are commonly characterised by thick sediment sequences dominated by allochthonous sediments deposited by sediment gravity flows. These allochthonous deposits commonly include turbidite muds, especially in distal settings. The present research assesses the significance of thick mud turbidites in deep sea basin plain sedimentation. Investigation of basin plain sequences enhances our understanding of how sediment proceeds from the continental shelves or other high ground to the deep sea, and thereby how basins develop and fill. Deep sea basin plain sediments are generally rare in the geological record, because they tend to be subducted in the long term. Until relatively recently the turbidite facies model was largely based on the study of proximal turbidites from the ancient record. However, effective facies models must combine data from both ancient and recent sediments. Our knowledge concerning the nature and extent of turbidites in modern oceans has increased markedly in recent years and there is a need to refine the turbidite facies model considering new data. This research uses the extensive database of over 80 good quality piston cores collected from the Madeira Abyssal Plain (Canary Basin, NE Atlantic) over the last decade to describe the evolution of a modern oceanic basin fill. The late Quaternary sequence is dominated by commonly thick, laterally extensive turbidite muds, many of which have been deposited by large volume turbidity currents. Complex coarse-grained basal facies in many turbidites are interpreted as caused by fluctuating flow velocities and reflection from adjacent high ground. In some settings, turbiditic and hemipelagic deep sea muds can appear visually very similar. However, this research demonstrates that they can be distinguished through rigorous sedimentological analysis. Such analysis is used to identify, otherwise obscure, turbidite muds in visually rather uniform sequences of allochthonous and autochthonous clayey nannofossil oozes which form basin fill in small graben within the western Lau Basin, SW Pacific.</p
G2 & G1 plants species of SW Colorado
No full textPresented at the 16th symposium held on September 27, 2019 in Grand Junction, Colorado.2019 G2 species of SW Colorado -- 2019 G1 species of SW Colorado
Differentiation of adipose-derived stem cells into Schwann cell phenotype induces expression of P2X receptors that control cell death.
No full textSchwann cells (SCs) are fundamental for development, myelination and regeneration in the peripheral nervous system. Slow growth rate and difficulties in harvesting limit SC applications in regenerative medicine. Several molecules, including receptors for neurosteroids and neurotransmitters, have been suggested to be implicated in regulating physiology and regenerative potential of SCs. Adipose-derived stem cells (ASCs) can be differentiated into SC-like phenotype (dASC) sharing morphological and functional properties with SC, thus representing a valid SC alternative. We have previously shown that dASC express γ-aminobutyric-acid receptors, which modulate their proliferation and neurotrophic potential, although little is known about the role of other neurotransmitters in ASC. In this study, we investigated the expression of purinergic receptors in dASC. Using reverse transriptase (RT)-PCR, western blot analyses and immunocytochemistry, we have demonstrated that ASCs express P2X3, P2X4 and P2X7 purinoceptors. Differentiation of ASCs towards glial phenotype was accompanied by upregulation of P2X4 and P2X7 receptors. Using Ca(2+)-imaging techniques, we have shown that stimulation of purinoceptors with adenosine 5'-triphosphate (ATP) triggers intracellular Ca(2+) signals, indicating functional activity of these receptors. Whole-cell voltage clamp recordings showed that ATP and BzATP induced ion currents that can be fully inhibited with specific P2X7 antagonists. Finally, using cytotoxicity assays we have shown that the increase of intracellular Ca(2+) leads to dASC death, an effect that can be prevented using a specific P2X7 antagonist. Altogether, these results show, for the first time, the presence of functional P2X7 receptors in dASC and their link with critical physiological processes such as cell death and survival. The presence of these novel pharmacological targets in dASC might open new opportunities for the management of cell survival and neurotrophic potential in tissue engineering approaches using dASC for nerve repair
Dependence of unsaturated chloride diffusion on the pore structure in cementitious materials
No full textConceptual analysis is performed to examine the effects of pore features on the water continuity in unsaturated porous systems. The roles of pore features in relative chloride diffusion coefficient (Drc) of mortar specimens at various degrees of water saturation (Sw) were studied based on mercury intrusion porosimetry and resistivity tests. It is found that the role of pore structure in the Drc-Sw relationship is a result of its effect on the water continuity. Porosity and tortuosity are not relevant to the Drc-Sw relationship. A finer pore size distribution or lower pore connectivity tends to result in a lower Drc. The pore size effect on the Drc is pronounced primarily at high Sw, while the Drc is dominated by the pore connectivity at low Sw. Cement mortar with a higher water-to-binder ratio shows larger chloride diffusion at high relative humidity levels but smaller chloride diffusion at low relative humidity levels.Accepted Author ManuscriptMaterials and Environmen
Total Cost of Ownership for Application Replatform by Open-source SW
No full textAbstractIn intra-company IT environment, the use of open-source software (OSS) should be expanded to reduce IT costs and to establish SW governance. This requires the migration of systems from the existing commercial SW to open-source SW, but the attempt of application replatform is prevented by the expenses for application reprogramming and data migration. This study proposes a methodology for TCO calculation of application replatform using open-source SW. In practice, a five-year TCO shows a cost reduction effect of 78% - 83%. This TCO could be further reduced if the application size is increased due to data accumulation and the company gets open-source SW capabilities internally. In addition, it is possible to directly apply an application developed from open-source SW to a virtualized infrastructure environment, which enables to operate in a hybrid cloud environment. This enables a scalable, efficient and flexible IT operation and a sustainable TCO reduction in the futur
Review of previous meetings, Part 3: Montrose, SW Colorado, G2G3 species
No full textSymposium held on September 28, 2012 in Canyon City, Colorado.Title from website.2008 Montrose: SW Colorado G2G3 species -- 2009 Loveland: NW & central Colorado G2G3 species
Review of previous meetings, Part 3: SW Colorado G2, NW Colorado G2 species
No full textSymposium held on September 23, 2016 in Boulder, Colorado.Title page states Golden, Colorado, should be Boulder, Colorado.Title from website.2008/2016 SW Colorado G2G3 species -- 2009/2014 NW & central Colorado G2G3 species
Overdiagnosis in breast cancer screening: the importance of length of observation period and lead time
No full textPMCID: PMC3706885This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Change management of the SW projects in the small and medium business
No full textThe bachelor thesis focuses on SW projects, ways of their management and mainly change management in the small and medium business. This thesis is devided into two parts. Author deals with SW projects and most common mistakes during their development in the theory part. The main aim of this part is to refer to these mistakes the reader, who is interested in SW projects. Next, there is a comparision of the two famous methodics, which are well-known in the SW development. These are ITIL and RUP. Author will choose the one, which will be more acceptable for the Cleverdecision. At this time, Cleverdecision has no change management and every change during the SW development is managed by contracting condition. That is why author formulates the ways of change management in the practical part. This will be based on the chosen methodics from the theory part. This formulation is the main aim of this thesis. The contribution of the thesis is in the definition of the change management workflow and in the proposition of the templates for setting the change requests. These templates are sufficient for unification concepts and easier specification of the change requests. Insertion of the change management into the contract is part of the thesis as well
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