36 research outputs found

    Decoupling marine export production from new production

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    We investigate the relationship between annually integrated new and export production for the central Californian marine upwelling system using an eddy-resolving coupled physical-ecosystem-biogeochemical model. We find that when averaged over the annual cycle lateral transport leads to a substantial spatial decoupling of export from new production, with a length-scale of decoupling on the order of 300 km. The decoupling is largely caused by mean horizontal fluxes induced by persistent meso- and submesoscale circulation structures and to a lesser degree by the mean lateral offshore transport induced by Ekman transport. This indicates that the concept of numerically equal new and export production has to be used with great care, particularly in dynamic oceanic environments

    T-level downstaging and complete pathologic response after preoperative long-term radiochemotherapy for locally advanced rectal cancer

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    Advantages of neoadjuvant chemoradiotherapy for locally advanced carcinoma of the middle and the lower third of the rectum are downstaging and downsizing of the tumor. Results of pathologic results are affected by post-treatment tissue changes and may influence the choice of surgical procedure. Forthy-three consecutive patients (27 male, 16 female; mean age 64 years) were operated after receiving a long-term chemoradiotherapy during a period of 16 months. The data of initial staging procedure (high resolution magnetic resonance imaging) and results of pathological examination of the surgical specimens were analyzed. Regression of tumor was assessed by the absence of vital tumor cells and the post-treatment fibrotic tissue alterations. Regression of tumor size was seen in 42/43 patients leading to an improved T-stage in 27 patients. R0-resection was possible in all cases, although there was a perirectal tumor infiltration to less than 2 mm to circumference of the surgical specimen in 2 cases and unexpected small liver metastasis in 5 cases. Complete remission rate was 23.3% (10 cases). Detecting small amounts of vital tumor cells in altered tissue after chemoradiotherapy is a major problem of pathological examination procedure and should be taken into consideration by the surgeons. The choice of operation (resection vs. abdominoperineal extirpation vs. local excision) should be committed to the initial imaging procedure and not to any restaging procedure after neoadjuvant chemoradiotherap

    Sustained growth of the Southern Ocean carbon storage in a warming climate

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    Abstract We investigate the mechanisms controlling the evolution of Southern Ocean carbon storage under a future climate warming scenario. A subset of Coupled Model Intercomparison Project Phase 5 models predicts that the inventory of biologically sequestered carbon south of 40°S increases about 18-34 Pg C by 2100 relative to the preindustrial condition. Sensitivity experiments with an ocean circulation and biogeochemistry model illustrates the impacts of the wind and buoyancy forcings under a warming climate. Intensified and poleward shifted westerly wind strengthens the upper overturning circulation, not only leading to an increased uptake of anthropogenic CO 2 but also releasing biologically regenerated carbon to the atmosphere. Freshening of Antarctic Surface Water causes a slowdown of the lower overturning circulation, leading to an increased Southern Ocean biological carbon storage. The rectified effect of these processes operating together is the sustained growth of the carbon storage in the Southern Ocean, even under the warming climate with a weaker global ocean carbon uptake

    Superhydrophobic Aluminum Surfaces: Preparation Routes, Properties and Artificial Weathering Impact

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    Among the materials that can be treated in order to impart superhydrophobic properties are many originally hydrophilic metals. For this, they must undergo a sequential treatment, including roughening and hydrophobic coating. This contribution presents various preparation routes along with various characterization methods, such as dynamic contact angle (DCA) measurements, scanning electron microscopy (SEM) and spectroscopic techniques (FT–IRRAS, XPS, EIS). Micro-rough surfaces of pure and alloyed aluminum were generated most easily by using a modifie Sulfuric Acid Anodization under Intensifie conditions (SAAi). This produces a micro-mountain-like oxide morphology with peak-to-valley heights of 2 μm and sub-μm roughness components. Additionally, micro-embossed and micro-blasted surfaces were investigated. These micro-roughened initial states were chemically modifie with a solution of a hydrophobic compound, such as the reactive f uoroalkylsilane PFATES, the reactive alkyl group containing polymer POMA, or the polymer Teflo ® AF. Alternatively, the chemical modificatio was made by a Hot Filament Chemical Vapor Deposition (HFCVD) of a PTFE layer. The latter can form a considerably higher thickness than the wet-deposited coatings, without detrimental leveling effects being observed in comparison with the original micro-rough surface. The inherent and controllable morphology of the PTFE layers represents an important feature. The impacts of a standardized artificia weathering (WTH) on the wetting behavior and the surface-chemical properties were studied and discussed in terms of possible damage mechanisms. A very high stability of the superhydrophobicity was observed for the f uorinated wet-deposited PFATES and Teflo ® AF coatings as well as for some of the PTFE layer variants, all on SAAi-pretreated substrates. Very good results were also obtained for specimens produced by appropriate mechanical roughening and PTFE coating

    Eddy-resolving simulation of plankton ecosystem dynamics in the California Current System

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    Author Posting. © Elsevier B.V., 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 53 (2006): 1483-1516, doi:10.1016/j.dsr.2006.06.005.We study the dynamics of the planktonic ecosystem in the coastal upwelling zone within the California Current System using a three-dimensional, eddy-resolving circulation model coupled to an ecosystem/biogeochemistry model. The physical model is based on the Regional Oceanic Modeling System (ROMS), configured at a resolution of 15 km for a domain covering the entire U.S. West Coast, with an embedded child grid covering the central California upwelling region at a resolution of 5 km. The model is forced with monthly mean boundary conditions at the open lateral boundaries as well as at the surface. The ecological/biogeochemical model is nitrogen based, includes single classes for phytoplankton and zooplankton, and considers two detrital pools with different sinking speeds. The model also explicitly simulates a variable chlorophyll-to-carbon ratio. Comparisons of model results with either remote sensing observations (AVHRR, SeaWiFS) or in situ measurements from the CalCOFI program indicate that our model is capable of replicating many of the large-scale, time averaged features of the coastal upwelling system. An exception is the underestimation of the chlorophyll levels in the northern part of the domain, perhaps because of the lack of short-term variations in the forcing from the atmosphere. Another shortcoming is that the modeled thermocline is too diffuse, and that the upward slope of the isolines toward the coast is too small. Detailed time-series comparisons with observations from Monterey Bay reveal similar agreements and discrepancies. We attribute the good agreement between the modeled and observed ecological properties in large part to the accuracy of the physical fields. In turn, many of the discrepancies can be traced back to our use of monthly mean forcing. Analysis of the ecosystem structure and dynamics reveal that the magnitude and pattern of phytoplankton biomass in the nearshore region are determined largely by the balance of growth and zooplankton grazing, while in the offshore region, growth is balanced by mortality. The latter appears to be inconsistent with in situ observations and is a result of our consideration of only one zooplankton size class (mesozooplankton), neglecting the importance of microzooplankton grazing in the offshore region. A comparison of the allocation of nitrogen into the different pools of the ecosystem in the 3-D results with those obtained from a box model configuration of the same ecosystem model reveals that only a few components of the ecosystem reach a local steady-state, i.e. where biological sources and sinks balance each other. The balances for the majority of the components are achieved by local biological source and sink terms balancing the net physical divergence, confirming the importance of the 3-D nature of circulation and mixing in a coastal upwelling system.Most of this work has been made possible by two grants from NASA. Additional support is acknowledged from NSF’s ITR program

    Daratumumab plus lenalidomide and dexamethasone for untreated myeloma

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    This is an accepted manuscript of an article published by Massachusetts Medical Society in New England Journal of Medicine on 30/05/2019, available online: https://doi.org/10.1056/NEJMoa1817249 The accepted version of the publication may differ from the final published version.Copyright © 2019 Massachusetts Medical Society. Lenalidomide plus dexamethasone is a standard treatment for patients with newly diagnosed multiple myeloma who are ineligible for autologous stem-cell transplantation. We sought to determine whether the addition of daratumumab would significantly reduce the risk of disease progression or death in this population. METHODS We randomly assigned 737 patients with newly diagnosed multiple myeloma who were ineligible for autologous stem-cell transplantation to receive daratumumab plus lenalidomide and dexamethasone (daratumumab group) or lenalidomide and dexamethasone alone (control group). Treatment was to continue until the occurrence of disease progression or unacceptable side effects. The primary end point was progression-free survival. RESULTS At a median follow-up of 28.0 months, disease progression or death had occurred in 240 patients (97 of 368 patients [26.4%] in the daratumumab group and 143 of 369 patients [38.8%] in the control group). The estimated percentage of patients who were alive without disease progression at 30 months was 70.6% (95% confidence interval [CI], 65.0 to 75.4) in the daratumumab group and 55.6% (95% CI, 49.5 to 61.3) in the control group (hazard ratio for disease progression or death, 0.56; 95% CI, 0.43 to 0.73; P<0.001). The percentage of patients with a complete response or better was 47.6% in the daratumumab group and 24.9% in the control group (P<0.001). A total of 24.2% of the patients in the daratumumab group, as compared with 7.3% of the patients in the control group, had results below the threshold for minimal residual disease (1 tumor cell per 105 white cells) (P<0.001). The most common adverse events of grade 3 or 4 were neutropenia (50.0% in the daratumumab group vs. 35.3% in the control group), anemia (11.8% vs. 19.7%), lymphopenia (15.1% vs. 10.7%), and pneumonia (13.7% vs. 7.9%).Published versio

    Effizienzsteigerung des AGG – eine rechtsökonomische Analyse

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    Dieser Beitrag untersucht das Urteil in dem Verfahren Frau Sule Eisele-Gaffaroglu gegen die R+V Lebensversicherungs AG, Arbeitsgericht Wiesbaden. Mittelpunkt der rechtsökonomischen Analyse bilden die drei für das Arbeitsrecht wesentlichen Paragrafen des Allgemeinen Gleichbehandlungsgesetzes (AGG): § 22 – Beweislast durch den Kläger und die mögliche Beweisverlagerung auf den Beklagten, § 15 Abs. 1 – Ersatz des materiellen Schadens und § 15 AGG Abs. 2 – Ersatz des immateriellen Schadens. Das Ergebnis der Urteilsanalyse ergibt, dass das AGG in der derzeit geltenden Fassung nicht effizient ist. Gleichzeitig zeigt der Beitrag aber auch Möglichkeiten zur Effizienzsteigerung des AGG auf.   Improvement in Efficiency of the General Act on Equal Treatment (AGG) – a Legal and Economic Analysis This article analyses the verdict reached at the end of the proceedings of Mrs Sule Eisele-Gaffaroglu versus R+V Lebensversicherungs AG, which was heard at the Wiesbaden labour court. The focal points of the analysis, which adopts both legal and economic perspectives, are the three main paragraphs of the General Act on Equal Treatment (Allgemeines Gleichbehandlungsgesetz – abbreviated AGG). These are paragraph 22, which covers the burden of proof for the plaintiff and reverses the onus of proof to the defendant; paragraph 15 (1), which addresses compensation for material damage; and paragraph 15 (2), which details monetary compensation for non-economic loss. The analysis shows that the AGG is, in its current form, not efficient. Building on the analysis and findings, this article provides recommendations for the adequate improvement of the AGG

    Hbgc123D: A High-Performance Computer Model Of Coupled Hydrogeological And Biogeochemical Processes

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    Groundwater flow and transport models have been used to assist management of subsurface water resources and water quality. The needs of more efficient use of technical and financial resources have recently motivated the development of more effective remediation techniques and complex models of coupled hydrogeological and biogeochemical processes. We present a high-performance computer model of the coupled processes, HBGC123D. The model uses a hybrid Eulerian-Lagrangian finite element method to solve the solute transport equation and a Newton\u27s method to solve the system of nonlinear, mixed kinetics and equilibrium reaction equations. Application of the model to a laboratory soil column with multispecies tracer injection suggests that one may use the model to derive important parameters of subsurface solute fate and transport. These parameters may be used for predictive purpose in similar field problems. To this end, we present a three-dimensional, hypothetical bioremediation simulation on an aquifer contaminated by CoNTA. The simulation suggests that, using oxygen alone to stimulate the biodegradation of the contaminant, one may reduce the waste to 40% in 10 years. Using a refined mesh of this three-dimensional model, we also conduct a performance study of HBGC123D on an array of SGI Origin 2000 distributed shared-memory processors. Both the computational kernels and the entire model show very good performance up to 32 processors. The CPU time is essentially reduced by 20-fold using 64 processors. This result suggests that HBGC123D may be a useful tool in assisting environmental restoration efforts such as waste site characterization and remediation. © 2001 Elsevier Science Ltd. All rights reserved
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