102 research outputs found
Evidence of Presence of the Eltville Tuff Layer in Dutsch and Belgian Limbourg and the Consequences for the Loess Stratigraphy
Anfang 1979 ist zum ersten Male in den Niederlanden ein vulkanischer Tuff in den Lößablagerungen von Süd-Limburg gefunden worden (Meijs 1980a). Auf Grund der stratigraphischen Lage, des makroskopischen Aussehens und der mineralogischen Zusammensetzung wurde dieser Tuff mit dem Eltviller Tuff korreliert. In dieser Veröffentlichung werden die Korrelierungsbeweisgründe eingehend behandelt und mit den Ergebnissen mikromorphologischer und röntgenologischer Untersuchungen ergänzt. Die Entdeckung des Eltviller Tuffs in dieser Region gerade unter dem Kesselt-Paläoboden (= Nagelbeek Horizont) bedeutet, daß dieser Paläoboden ein stratigraphisches Äquivalent des E4-Naßbodens ist. Dieses steht im Widerspruch mit der in Belgien und den Niederlanden herrschenden Ansicht, laut der der Kesselt-Paläoboden mit dem im Denekamp Interstadial geformten Stillfried-B Paläoboden korreliert wird (z. B. Zagwijn & Paepe 1968). Der letztgenannte Paläoboden liegt aber stratigraphisch unter dem Eltviller Tuff und ist ungefähr 10.000 Jahr älter als der E4-Naßboden (Semmel 1967, Vogel & van der Hammen 1967).researc
The AARTFAAC All-Sky Monitor: System Design and Implementation
The Amsterdam-ASTRON Radio Transients Facility And Analysis Center (AARTFAAC)
all sky monitor is a sensitive, real time transient detector based on the Low
Frequency Array (LOFAR). It generates images of the low frequency radio sky
with spatial resolution of 10s of arcmin, MHz bandwidths, and a time cadence of
a few seconds, while simultaneously but independently observing with LOFAR. The
image timeseries is then monitored for short and bright radio transients. On
detection of a transient, a low latency trigger will be generated for LOFAR,
which can interrupt its schedule to carry out follow-up observations of the
trigger location at high sensitivity and resolutions. In this paper, we
describe our heterogeneous, hierarchical design to manage the 240 Gbps raw data
rate, and large scale computing to produce real-time images with minimum
latency. We discuss the implementation of the instrumentation, its performance,
and scalability.Comment: Submitted to Journal of Astronomical Instrumentation, Special issue
on 'Digital Signal Processing (DSP) in Radio Astronomy
Micronutrient Status of Critically Ill Patients with COVID-19 Pneumonia
Micronutrient deficiencies can develop in critically ill patients, arising from factors such as decreased intake, increased losses, drug interactions, and hypermetabolism. These deficiencies may compromise important immune functions, with potential implications for patient outcomes. Alternatively, micronutrient blood levels may become low due to inflammation-driven redistribution rather than consumption. This explorative pilot study investigates blood micronutrient concentrations during the first three weeks of ICU stay in critically ill COVID-19 patients and evaluates the impact of additional micronutrient administration. Moreover, associations between inflammation, disease severity, and micronutrient status were explored. We measured weekly concentrations of vitamins A, B6, D, and E; iron; zinc; copper; selenium; and CRP as a marker of inflammation state and the SOFA score indicating disease severity in 20 critically ill COVID-19 patients during three weeks of ICU stay. Half of the patients received additional (intravenous) micronutrient administration. Data were analyzed with linear mixed models and Pearson’s correlation coefficient. High deficiency rates of vitamins A, B6, and D; zinc; and selenium (50–100%) were found at ICU admission, along with low iron status. After three weeks, vitamins B6 and D deficiencies persisted, and iron status remained low. Plasma levels of vitamins A and E, zinc, and selenium improved. No significant differences in micronutrient levels were found between patient groups. Negative correlations were identified between the CRP level and levels of vitamins A and E, iron, transferrin, zinc, and selenium. SOFA scores negatively correlated with vitamin D and selenium levels. Our findings reveal high micronutrient deficiency rates at ICU admission. Additional micronutrient administration did not enhance levels or expedite their increase. Spontaneous increases in vitamins A and E, zinc, and selenium levels were associated with inflammation resolution, suggesting that observed low levels may be attributed, at least in part, to redistribution rather than true deficiencies.</p
Micronutrient Status of Critically Ill Patients with COVID-19 Pneumonia
Micronutrient deficiencies can develop in critically ill patients, arising from factors such as decreased intake, increased losses, drug interactions, and hypermetabolism. These deficiencies may compromise important immune functions, with potential implications for patient outcomes. Alternatively, micronutrient blood levels may become low due to inflammation-driven redistribution rather than consumption. This explorative pilot study investigates blood micronutrient concentrations during the first three weeks of ICU stay in critically ill COVID-19 patients and evaluates the impact of additional micronutrient administration. Moreover, associations between inflammation, disease severity, and micronutrient status were explored. We measured weekly concentrations of vitamins A, B6, D, and E; iron; zinc; copper; selenium; and CRP as a marker of inflammation state and the SOFA score indicating disease severity in 20 critically ill COVID-19 patients during three weeks of ICU stay. Half of the patients received additional (intravenous) micronutrient administration. Data were analyzed with linear mixed models and Pearson’s correlation coefficient. High deficiency rates of vitamins A, B6, and D; zinc; and selenium (50–100%) were found at ICU admission, along with low iron status. After three weeks, vitamins B6 and D deficiencies persisted, and iron status remained low. Plasma levels of vitamins A and E, zinc, and selenium improved. No significant differences in micronutrient levels were found between patient groups. Negative correlations were identified between the CRP level and levels of vitamins A and E, iron, transferrin, zinc, and selenium. SOFA scores negatively correlated with vitamin D and selenium levels. Our findings reveal high micronutrient deficiency rates at ICU admission. Additional micronutrient administration did not enhance levels or expedite their increase. Spontaneous increases in vitamins A and E, zinc, and selenium levels were associated with inflammation resolution, suggesting that observed low levels may be attributed, at least in part, to redistribution rather than true deficiencies.</p
Material Symmetry to Partition Endgame Tables
Many games display some kind of material symmetry . That
is, some sets of game elements can be exchanged for another set of game
elements, so that the resulting position will be equivalent to the original
one, no matter how the elements were arranged on the board. Material
symmetry is routinely used in card game engines when they normalize
their internal representation of the cards.
Other games such as chinese dark chess also feature some form of
material symmetry, but it is much less clear what the normal form of a
position should be. We propose a principled approach to detect material
symmetry. Our approach is generic and is based on solving multiple rel-
atively small sub-graph isomorphism problems. We show how it can be
applied to chinese dark chess , dominoes , and skat .
In the latter case, the mappings we obtain are equivalent to the ones
resulting from the standard normalization process. In the two former
cases, we show that the material symmetry allows for impressive savings
in memory requirements when building endgame tables. We also show
that those savings are relatively independent of the representation of the
tables
Optimized Trigger for Ultra-High-Energy Cosmic-Ray and Neutrino Observations with the Low Frequency Radio Array
When an ultra-high energy neutrino or cosmic ray strikes the Lunar surface a
radio-frequency pulse is emitted. We plan to use the LOFAR radio telescope to
detect these pulses. In this work we propose an efficient trigger
implementation for LOFAR optimized for the observation of short radio pulses.Comment: Submitted to Nuclear Instruments and Methods in Physics Research
Section
The distributed ASCI supercomputer project
The Distributed ASCI Supercomputer (DAS) is a homogeneous wide-area distributed system consisting of four cluster computers at different locations. DAS has been used for research on communication software, parallel languages and programming systems, schedulers, parallel applications, and distributed applications. The paper gives a preview of the most interesting research results obtained so far in the DAS project
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