2,246 research outputs found
Can Frequency Domain Heart Rate Measures Detect Impaired Driver Performance?
An overnight driving simulation scenario with partial sleep deprivation was utilized to induce driver performance impairment. Heart rate (HR) was recorded over the entire experiment; frequency domain HR measures were derived and correlated to variation of lane deviation (VLD), a driving performance measure, and to the driver\u27s state, which was estimated by the Karolinska Sleepiness Scale (KSS). The aim of this study is to evaluate whether frequency domain heart rate measures can be used to detect impaired driver performance as well as reduced driver state. We generalize the concept of the conventional frequency domain HR measures – namely the very-low frequency (VLF), low frequency (LF) band and high frequency (HF) band – into finer-grained frequency bands of 0.02 Hz width. These newly defined frequency bands show a more detailed correlation to driving performance and to driver sleepiness state, taking subjectspecific differences into account
Synthesis and characterization of dicarboxymethyl cellulose
Associate Laboratory for Green Chemistry-LAQV which is financed by national funds from FCT/MCTES (UID/QUI/50006/2019).
FCT, Portugal (ROTEIRO/0031/2013–PINFRA/22161/2016, co-financed by FEDER through COMPETE 2020, POCI, and PORL and FCT through PIDDAC).Synthesis of dicarboxymethyl cellulose (DCMC) under heterogeneous conditions was examined. Cellulose was etherified using sodium bromomalonate in isopropanol/water in the presence of NaOH. The reaction was performed with five different NaOH concentrations (5–30 w/v %) and the products were characterized by anion-exchange high-performance liquid chromatography (AE-HPLC), inductively coupled plasma atomic emission- (ICP-AES), Fourier transform infrared- (FTIR), and nuclear magnetic resonance (1D-/2D-NMR) spectroscopy. Adjusting the amount of NaOH resulted in increasing functionalization of the cellulose achieving an average degree of substitution (DS) between 0.05 and 0.51. Both ICP-AES and AE-HPLC gave comparable DS values. NMR spectroscopic analysis showed that etherification occurred preferably at O-6 and, to a certain extent, at the secondary positions depending on the reaction conditions. Graphic abstract: [Figure not available: see fulltext.].authorsversionpublishe
First On-Sky High Contrast Imaging with an Apodizing Phase Plate
We present the first astronomical observations obtained with an Apodizing
Phase Plate (APP). The plate is designed to suppress the stellar diffraction
pattern by 5 magnitudes from 2-9 lambda/D over a 180 degree region. Stellar
images were obtained in the M' band (4.85 microns) at the MMTO 6.5m telescope,
with adaptive wavefront correction made with a deformable secondary mirror
designed for low thermal background observations. The measured PSF shows a halo
intensity of 0.1% of the stellar peak at 2 lambda/D (0.36 arcsec), tapering off
as r^{-5/3} out to radius 9 lambda/D. Such a profile is consistent with
residual errors predicted for servo lag in the AO system.
We project a 5 sigma contrast limit, set by residual atmospheric
fluctuations, of 10.2 magnitudes at 0.36 arcsec separation for a one hour
exposure. This can be realised if static and quasi-static aberrations are
removed by differential imaging, and is close to the sensitivity level set by
thermal background photon noise for target stars with M'>3. The advantage of
using the phase plate is the removal of speckle noise caused by the residuals
in the diffraction pattern that remain after PSF subtraction. The APP gives
higher sensitivity over the range 2-5 lambda/D compared to direct imaging
techniques.Comment: 22 pages, 5 figures, 1 table, ApJ accepte
Architecture of a consent management suite and integration into IHE-based regional health information networks
<p>Abstract</p> <p>Background</p> <p>The University Hospital Heidelberg is implementing a Regional Health Information Network (RHIN) in the Rhine-Neckar-Region in order to establish a shared-care environment, which is based on established Health IT standards and in particular Integrating the Healthcare Enterprise (IHE). Similar to all other Electronic Health Record (EHR) and Personal Health Record (PHR) approaches the chosen Personal Electronic Health Record (PEHR) architecture relies on the patient's consent in order to share documents and medical data with other care delivery organizations, with the additional requirement that the German legislation explicitly demands a patients' opt-in and does not allow opt-out solutions. This creates two issues: firstly the current IHE consent profile does not address this approach properly and secondly none of the employed intra- and inter-institutional information systems, like almost all systems on the market, offers consent management solutions at all. Hence, the objective of our work is to develop and introduce an extensible architecture for creating, managing and querying patient consents in an IHE-based environment.</p> <p>Methods</p> <p>Based on the features offered by the IHE profile Basic Patient Privacy Consent (BPPC) and literature, the functionalities and components to meet the requirements of a centralized opt-in consent management solution compliant with German legislation have been analyzed. Two services have been developed and integrated into the Heidelberg PEHR.</p> <p>Results</p> <p>The standard-based Consent Management Suite consists of two services. The Consent Management Service is able to receive and store consent documents. It can receive queries concerning a dedicated patient consent, process it and return an answer. It represents a centralized policy enforcement point. The Consent Creator Service allows patients to create their consents electronically. Interfaces to a Master Patient Index (MPI) and a provider index allow to dynamically generate XACML-based policies which are stored in a CDA document to be transferred to the first service. Three workflows have to be considered to integrate the suite into the PEHR: recording the consent, publishing documents and viewing documents.</p> <p>Conclusions</p> <p>Our approach solves the consent issue when using IHE profiles for regional health information networks. It is highly interoperable due to the use of international standards and can hence be used in any other region to leverage consent issues and substantially promote the use of IHE for regional health information networks in general.</p
Strain and composition dependence of the orbital polarization in nickelate superlattices
A combined analysis of x-ray absorption and resonant reflectivity data was
used to obtain the orbital polarization profiles of superlattices composed of
four-unit-cell-thick layers of metallic LaNiO3 and layers of insulating RXO3
(R=La, Gd, Dy and X=Al, Ga, Sc), grown on substrates that impose either
compressive or tensile strain. This superlattice geometry allowed us to partly
separate the influence of epitaxial strain from interfacial effects controlled
by the chemical composition of the insulating blocking layers. Our quantitative
analysis reveal orbital polarizations up to 25%. We further show that strain is
the most effective control parameter, whereas the influence of the chemical
composition of the blocking layers is comparatively small.Comment: 9 pages, 8 figure
Hochauflösende Bestimmung der konzentrationsabhängigen Substrataffinität von Enzymen im Tiefenverlauf eines Dystric Cambisols
Enzyme sind für die Umsetzung und Speicherung von Nährstoffen im Boden von großer Bedeutung. Im Gegensatz zum Oberboden sind die Prozesse und Mechanismen der Kohlenstoff- und Nährstoffflüsse im Unterboden jedoch weitaus weniger erforscht und deren Wichtigkeit im globalen Stoffkreislauf weitestgehend unterschätzt. Für die Untersuchungen wurden auf der Langzeitmessfläche "Grinderwald" der SUBSOM Forschergruppe 40 km nord-westlich von Hannover aus einem Dystric Cambisol (FAO-WRB 2014) unter Buchenwald Bodenproben aus 15 Tiefenstufen (0-1 m alle 10 cm und 1-2 m alle 20 cm) an drei fest installierten Observatorien bis zu einer Tiefe von 2 m mit Rammkernsonden entnommen. Je Observatorium wurden zwei Teilflächen mit je drei Bohrungen beprobt, die für die weitere Analyse zu tiefenbezogenen Mischproben vereint wurden. Insgesamt wurden daher sechs Tiefenprofile analysiert. Stellvertretend für den C-, C/N-, N-, P- und S-Kreislauf wurde die Enzymaktivität von β-Glucosidase (C), Chitinase (C/N), Arginin-Aminopeptidase (N), saure-Phosphatase (P) und Sulfatase (S) mit dem von Marx et al. (2001) entwickelten Mikrotiterplattensystems bestimmt. Zur Ermittlung der Michaelis-Menten Kinetik wurde dabei die Reaktionsraten der Enzyme bei steigenden Substratkonzentrationen bestimmt, um somit die maximale Substrataffinität abbilden zu können. Für jedes Enzym wurde die Reaktionsrate bei den Substratkonzentrationen 0, 25, 50, 75, 100 und 200 µmol pro g Boden bestimmt. Es wird erwartet, dass die Ergebnisse dieser Untersuchung Aufschluss über die spezifischen Reaktionsraten von Enzymen entlang des Tiefengradienten liefern, um somit das Verständnis von dem Einfluss von Enzymen auf die Stoffumsätze im Boden weiter verbessern zu können
About the connection between vacuum birefringence and the light-light scattering amplitude
Birefringence phenomena stemming from vacuum polarization are revisited in
the framework of coherent scattering. Based on photon-photon scattering, our
analysis brings out the direct connection between this process and vacuum
birefringence. We show how this procedure can be extended to the Kerr and the
Cotton-Mouton birefringences in vacuum, thus providing a unified treatment of
various polarization schemes, including those involving static fields
Is there a Pronounced Giant Dipole Resonance in ^4He?
A four-nucleon calculation of the total ^4He photodisintegration cross
section is performed. The full final-state interaction is taken into account
for the first time. This is achieved via the method of the Lorentz integral
transform. Semi-realistic NN interactions are employed. Different from the
known partial two-body ^4He(\gamma,n)^3He and ^4He(\gamma,p)^3H cross sections
our total cross section exhibits a pronounced giant resonance. Thus, in
contrast to older data, we predict quite a strong contribution of
the channel at the giant resonance peak energy.Comment: 10 pages, Latex (REVTEX), 4 Postscript figures, to appear in Phys.
Rev. Let
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