110 research outputs found
Experimentelle Untersuchungen zum Fließverhalten von wassergesättigten, grobkörnigen Böden
Die Arbeit beschäftigt sich mit der Grundlagenforschung zum Fließverhalten von wassergesättigten, grobkörnigen Böden, die im Rahmen eines DFG-Forschungsvorhabens gemeinsam mit der Ruhr-Universität Bochum durchgeführt wurde. Durch die Entwicklung eines neuartigen Großversuchsstands und unter Verwendung der optischen Messmethode Particle-Image-Velocimetry (PIV) konnten detaillierte Kenntnisse über das Fließverhalten unterschiedlicher Böden gewonnen werden. Auf Basis der gewonnenen Kenntnisse zur Geschwindigkeitsentwicklung der wassergesättigten, grobkörnigen Böden konnte ein Vergleich zur Geschwindigkeit von Wasser nach der Ausflussformel von Torricelli gezogen werden. Für die untersuchten sandigen Böden konnte die den Untersuchungen zugrunde liegende Annahme, dass der wassergesättigte, grobkörnige Boden wie eine zähe Flüssigkeit fließt, bestätigt und ein erster Ansatz für die Erweiterung der Ausflussformel nach Torricelli entwickelt werden. Die gewonnen Erkenntnisse sind eine solider Datenfundus zur Implementierung und Kalibrierung von numerischen Modellen und dienen u.a. zur Bestimmung der Viskosität von Boden-Wasser-Gemischen
Safety Assurance for Challenging Geotechnical Civil Engineering Constructions in Urban Areas
Safety is the most important aspect during design, construction and service time of any structure, especially for challenging projects like high-rise buildings and tunnels in urban areas. A high level design considering the soil-structure- interaction, based on a qualified soil investigation is required for a safe and optimised design. Due to the complexity of geotechnical constructions the safety assurance guaranteed by the 4-eye-principle is essential. The 4-eye-principle consists of an independent peer review by publicly certified experts combined with the observational method. The paper presents the fundamental aspects of safety assurance by the 4-eye-principle. The application is explained on several examples, as deep excavations, complex foundation systems for high-rise buildings and tunnel constructions in urban areas. The experiences made in the planning, design and construction phases are explained and for new inner urban projects recommendations are given
Critical Micronutrients in Pregnancy, Lactation, and Infancy: Considerations on Vitamin D, Folic Acid, and Iron, and Priorities for Future Research
The Early Nutrition Academy and the European Commission-funded EURRECA Network of Excellence jointly sponsored a scientific workshop on critical micronutrients in pregnancy, lactation, and infancy. Current knowledge and unresolved questions on the supply of vitamin D, folic acid, and iron for pregnant women, lactating women, and infants, and their health effects were discussed. The question was addressed of whether, and under which circumstances, supplementation with these micronutrients in addition to usual dietary intakes is advisable. The workshop participants concluded that public health strategies for improving supplementation with these micronutrients in pregnancy, lactation, and infancy are required. Further research priorities should focus on adequately powered human intervention trials to obtain a stronger evidence base for the amounts of vitamin D, folic acid, and iron that have optimal effects on health. The conclusions of the workshop should help to inform the scientific community as well as public health policy strategies. Copyright (C) 2011 S. Karger AG, Base
Impacto na Aprendizagem Envolvendo o Desenvolvimento de Aplicativos na Educação Básica: um Mapeamento Sistemático da Literatura
O ensino de computação na Educação Básica tem se apresentado como uma alternativa para o desenvolvimento de habilidades do século XXI. Vem sendo tipicamente ensinado por meio de linguagens de programação como App Inventor, ferramenta que possibilita o desenvolvimento de aplicativos móveis para smartphones. Porém, ainda não se tem uma compreensão dos impactos que práticas pedagógicas têm gerado na aprendizagem dos alunos com esse enfoque específico no ambiente de programação. O artigo apresenta o resultado de um Mapeamento Sistemático da Literatura em que se buscou analisar os impactos de práticas pedagógicas de desenvolvimento de aplicativos com o App Inventor na aprendizagem de conteúdos curriculares da Educação Básica tanto no Brasil quanto internacionalmente. Os resultados mostram que há práticas realizadas em ambiente de programação em atividades extracurriculares, especialmente no contraturno e em período de férias, indicando que há ainda poucas práticas interligando o currículo com o App Inventor. Os resultados positivos têm relação com as estratégias metodológicas escolhidas para a aplicação das práticas, cujos melhores resultados estão relacionados aos interesses, aos problemas do cotidiano dos alunos e a partir da formação de professores das instituições. Por outro lado, as dificuldades apontadas envolvem limitações dos alunos em conhecimentos básicos e pouco tempo para o desenvolvimento das atividades
Formation of ultracold SrYb molecules in an optical lattice by photoassociation spectroscopy: theoretical prospects
State-of-the-art {\em ab initio} techniques have been applied to compute the
potential energy curves for the SrYb molecule in the Born-Oppenheimer
approximation for the ground state and first fifteen excited singlet and
triplet states within the coupled-cluster framework. The leading long-range
coefficients describing the dispersion interactions at large interatomic
distances are also reported. The electric transition dipole moments have been
obtained as the first residue of the polarization propagator computed with the
linear response coupled-cluster method restricted to single and double
excitations. Spin-orbit coupling matrix elements have been evaluated using the
multireference configuration interaction method restricted to single and double
excitations with a large active space. The electronic structure data was
employed to investigate the possibility of forming deeply bound ultracold SrYb
molecules in an optical lattice in a photoassociation experiment using
continuous-wave lasers. Photoassociation near the intercombination line
transition of atomic strontium into the vibrational levels of the strongly
spin-orbit mixed , , , and states with
subsequent efficient stabilization into the vibrational
level of the electronic ground state is proposed. Ground state SrYb molecules
can be accumulated by making use of collisional decay from
to . Alternatively, photoassociation and stabilization to
can proceed via stimulated Raman adiabatic passage
provided that the trapping frequency of the optical lattice is large enough and
phase coherence between the pulses can be maintained over at least tens of
microseconds
Y-box protein-1/p18 fragment identifies malignancies in patients with chronic liver disease
<p>Abstract</p> <p>Background</p> <p>Immunohistochemical detection of cold shock proteins is predictive for deleterious outcome in various malignant diseases. We recently described active secretion of a family member, denoted Y-box (YB) protein-1. We tested the clinical and diagnostic value of YB-1 protein fragment p18 (YB-1/p18) detection in blood for malignant diseases.</p> <p>Methods</p> <p>We used a novel monoclonal anti-YB-1 antibody to detect YB-1/p18 by immunoblotting in plasma samples of healthy volunteers (n = 33), patients with non-cancerous, mostly inflammatory diseases (n = 60), hepatocellular carcinoma (HCC; n = 25) and advanced solid tumors (n = 20). YB-1/p18 was then tested in 111 patients with chronic liver diseases, alongside established tumor markers and various diagnostic measures, during evaluation for potential liver transplantation.</p> <p>Results</p> <p>We developed a novel immunoblot to detect the 18 kD fragment of secreted YB-1 in human plasma (YB-1/p18) that contains the cold-shock domains (CSD) 1-3 of the full-length protein. YB-1/p18 was detected in 11/25 HCC and 16/20 advanced carcinomas compared to 0/33 healthy volunteers and 10/60 patients with non-cancerous diseases. In 111 patients with chronic liver disease, YB-1/p18 was detected in 20 samples. Its occurrence was not associated with advanced Child stages of liver cirrhosis or liver function. In this cohort, YB-1/p18 was not a good marker for HCC, but proved most powerful in detecting malignancies other than HCC (60% positive) with a lower rate of false-positive results compared to established tumor markers. Alpha-fetoprotein (AFP) was most sensitive in detecting HCC, but simultaneous assessment of AFP, CA19-9 and YB-1/p18 improved overall identification of HCC patients.</p> <p>Conclusions</p> <p>Plasma YB-1/p18 can identify patients with malignancies, independent of acute inflammation, renal impairment or liver dysfunction. The detection of YB-1/p18 in human plasma may have potential as a tumor marker for screening of high-risk populations, e.g. before organ transplantation, and should therefore be evaluated in larger prospective studies.</p
LTER HAUSGARTEN 2018 - Long-Term Ecological Research in the Fram Strait, Cruise No. MSM77, September 15 - October 13, 2018, Longyearbyen (Svalbard) - Edinburgh (Scotland)
The 77th cruise of the RV MARIA S. MERIAN contributed to various large national and international research and infrastructure projects (FRAM, ARCHES, INTAROS, ICOS, SIOS) as well as to the research programme PACES-II (Polar Regions and Coasts in the changing Earth System) of the Alfred-Wegener-Institute Helmholtz-Center for Polar and Marine Research (AWI). Investigations within Work Package 4 (Arctic sea ice and its interaction with ocean and ecosystems) of the PACES-II programme, aim at assessing and quantifying ecosystem changes from surface waters to the deep ocean in response to the retreating sea ice, and at exploring the most important (feedback) processes determining temporal and spatial variability. Contributions to the PACES-II Work Package 6 (Large scale variability and change in polar benthic biota and ecosystem functions) include the identification of spatial patterns and temporal trends in relevant benthic community functions, and the development of a comprehensive science community reference collection of observational data. Work carried out within WPs 4 and 6 will support the time-series studies at the LTER (Long-Term Ecological Research) observatory HAUSGARTEN (Fig. 1.1), where we document Global Change induced environmental variations on a polar deep-water ecosystem. This work is carried out in close co-operation between the HGF-MPG Joint Research Group on Deep-Sea Ecology and Technology and the PEBCAO Group (Phytoplankton Ecology and Biogeochemistry in the Changing Arctic Ocean) at AWI as well as the working group Microbial Geochemistry at the GEOMAR and the HGF Young Investigators Group SEAPUMP (Seasonal and regional food web interactions with the biological pump)
Long-Term Summertime Investigations of Pelagic and Benthic Realms with Continuous Observations of Vertical Particle Flux in the Fram Strait and the Central Arctic Ocean
Sea ice volume and extent currently experience massive reduction in the Arctic Ocean due to climate change. Our long-term study aims at tracing effects of environmental changes in pelagic and benthic systems and investigate accompanying impacts on the fate of organic matter produced in the upper water column on its way down to the seafloor. Since the start of our observations in 1999, we have already seen some effects and will present selected data sets from the upper water column and benthic data during summer expeditions as well as results from vertical particle flux measurements that were obtained from annually deployed sediment traps at the LTER (Long-Term Ecological Research) observatory HAUSGARTEN in the eastern Fram Strait (79°/4°E) and on fewer occasions in the central Arctic Ocean (CAO).
Highest biomass was found in the eastern Fram Strait and lowest in the heavily ice-covered regions in the CAO. Flux rates of POC where at least one order of magnitude lower in the CAO than in the eastern Fram Strait. While in the CAO ice algae dominate the recognizable flux fraction, faecal material prevailed in eastern Fram Strait traps. This points towards different systems of organic matter production and modification and, thus, different mechanisms determine the efficiency of the biological carbon pump. These differences are also reflected in the benthic communities in the CAO and in the eastern Fram Strait.
These first results have shown the importance of long-term observations and encouraged the continuation of the Arctic Ocean Observing System FRAM (FRontiers in Arctic marine Monitoring) to record environmental and biological data at high temporal and spatial resolution
- …