3,534 research outputs found
Effects of canola, wheat and faba bean on yield and nitrogen use efficiency in potato production systems
Non-Peer Reviewe
High accuracy measure of atomic polarizability in an optical lattice clock
Despite being a canonical example of quantum mechanical perturbation theory,
as well as one of the earliest observed spectroscopic shifts, the Stark effect
contributes the largest source of uncertainty in a modern optical atomic clock
through blackbody radiation. By employing an ultracold, trapped atomic ensemble
and high stability optical clock, we characterize the quadratic Stark effect
with unprecedented precision. We report the ytterbium optical clock's
sensitivity to electric fields (such as blackbody radiation) as the
differential static polarizability of the ground and excited clock levels:
36.2612(7) kHz (kV/cm)^{-2}. The clock's fractional uncertainty due to room
temperature blackbody radiation is reduced an order of magnitude to 3 \times
10^{-17}.Comment: 5 pages, 3 figures, 2 table
Sixty-five foot diameter DGB parachute planetary entry parachute program Design report
Structural design and component test data for disk gap-band planetary entry parachut
Photometric Mapping with ISOPHOT using the "P32" Astronomical Observation Template
The ``P32'' Astronomical Observation Template (AOT) provided a means to map
large areas of sky (up to 45 x 45 arcmin) in the far-infrared (FIR) at high
redundancy and with sampling close to the Nyquist limit using the ISOPHOT C100
(3 x 3) and C200 (2 x 2) detector arrays on board the Infrared Space
Observatory (ISO). However, the transient response behaviour of the Ga:Ge
detectors, if uncorrected, can lead to severe systematic photometric errors and
distortions of source morphology on maps. We describe the basic concepts of an
algorithm which can successfully correct for transient response artifacts in
P32 observations. Examples are given to demonstrate the photometric and imaging
performance of ISOPHOT P32 observations of point and extended sources corrected
using the algorithm. For extended sources we give the integrated flux densities
of the nearby galaxies NGC6946, M51 and M101 and an image of M101 at 100
micron.Comment: 15 pages, 16 figures, published in A&A 410, 107
Variability survey in the CoRoT SRa01 field: Implications of eclipsing binary distribution on cluster formation in NGC 2264
Time-series photometry of the CoRoT field SRa01 was carried out with the
Berlin Exoplanet Search Telescope II (BEST II) in 2008/2009. A total of 1,161
variable stars were detected, of which 241 were previously known and 920 are
newly found. Several new, variable young stellar objects have been discovered.
The study of the spatial distribution of eclipsing binaries revealed the higher
relative frequency of Algols toward the center of the young open cluster NGC
2264. In general Algol frequency obeys an isotropic distribution of their
angular momentum vectors, except inside the cluster, where a specific
orientation of the inclinations is the case. We suggest that we see the orbital
plane of the binaries almost edge-on.Comment: 18 pages, 8 figures, accepted for publication in Ap
The Berlin Exoplanet Search Telescope II. Catalog of Variable Stars. I. Characterization of Three Southern Target Fields
A photometric survey of three Southern target fields with BEST II yielded the
detection of 2,406 previously unknown variable stars and an additional 617
stars with suspected variability. This study presents a catalog including their
coordinates, magnitudes, light curves, ephemerides, amplitudes, and type of
variability. In addition, the variability of 17 known objects is confirmed,
thus validating the results. The catalog contains a number of known and new
variables that are of interest for further astrophysical investigations, in
order to, e.g., search for additional bodies in eclipsing binary systems, or to
test stellar interior models.
Altogether, 209,070 stars were monitored with BEST II during a total of 128
nights in 2009/2010. The overall variability fraction of 1.2-1.5% in these
target fields is well comparable to similar ground-based photometric surveys.
Within the main magnitude range of , we identify
0.67(3)% of all stars to be eclipsing binaries, which indicates a completeness
of about one third for this particular type in comparison to space surveys.Comment: accepted to A
Atypical presentation of Crimean-Congo haemorrhagic fever: Lessons learned
An atypical case of Crimean-Congo haemorrhagic fever is presented. The diagnosis of the case in the presence of several comorbidities was complicated and illustrates the importance of maintaining a high index of suspicion for viral haemorrhagic fever in cases presenting with multisystem disease and an epidemiological history that could present opportunities for exposure to a haemorrhagic fever virus
Drop-in biofuel production using fatty acid photodecarboxylase from Chlorella variabilis in the oleaginous yeast Yarrowia lipolytica.
Background: Oleaginous yeasts are potent hosts for the renewable production of lipids and harbor great potential for derived products, such as biofuels. Several promising processes have been described that produce hydrocarbon drop-in biofuels based on fatty acid decarboxylation and fatty aldehyde decarbonylation. Unfortunately, besides fatty aldehyde toxicity and high reactivity, the most investigated enzyme, aldehyde-deformylating oxygenase, shows unfavorable catalytic properties which hindered high yields in previous metabolic engineering approaches. Results: To demonstrate an alternative alkane production pathway for oleaginous yeasts, we describe the production of diesel-like, odd-chain alkanes and alkenes, by heterologously expressing a recently discovered light-driven oxidase from Chlorella variabilis (CvFAP) in Yarrowia lipolytica. Initial experiments showed that only strains engineered to have an increased pool of free fatty acids were susceptible to sufficient decarboxylation. Providing these strains with glucose and light in a synthetic medium resulted in titers of 10.9 mg/L of hydrocarbons. Using custom 3D printed labware for lighting bioreactors, and an automated pulsed glycerol fed-batch strategy, intracellular titers of 58.7 mg/L were achieved. The production of odd-numbered alkanes and alkenes with a length of 17 and 15 carbons shown in previous studies could be confirmed. Conclusions: Oleaginous yeasts such as Yarrowia lipolytica can transform renewable resources such as glycerol into fatty acids and lipids. By heterologously expressing a fatty acid photodecarboxylase from the algae Chlorella variabilis hydrocarbons were produced in several scales from microwell plate to 400 mL bioreactors. The lighting turned out to be a crucial factor in terms of growth and hydrocarbon production, therefore, the evaluation of different conditions was an important step towards a tailor-made process. In general, the developed bioprocess shows a route to the renewable production of hydrocarbons for a variety of applications ranging from being substrates for further enzymatic or chemical modification or as a drop-in biofuel blend
Religion ist irrational und Irrationalität ist dysfunktional?
Der Rational-Emotiven-Theorie (RET) von Albert Ellis zufolge sind irrationale Gedanken eine zentrale Ursache für dysfunktionale psychopathologische Zustände. Auch Religiosität wird in diesem Sinne als irrational dargestellt. Hieraus wird abgeleitet, dass religiösere Menschen in höherer Weise zu dysfunktionalen irrationalen Gedanken neigen, die wiederum die Lebenszufriedenheit negativ beeinflussen. Zur Hypothesenprüfung beantworteten Probanden in einer Fragebogenstudie Skalen zur Erfassung verschiedener Religiositätsaspekte (intrinsische und extrinsische Religiosität, Durch-Gott-Mediierte Kontrolle) und klinisch validierte Skalen zu irrationalen Einstellungen sowie eine Frage zur Lebenszufriedenheit. Es zeigen sich signifikante Zusammenhänge zwischen den Religiositätsskalen und Irrationalitätsskalen. Insbesondere die extrinsische Religiosität, die als oberflächlicher Glaube zur bloßen Sicherung von sozialer Akzeptanz konzipiert ist, korreliert signifikant stärker mit klinischen Irrationalitätsskalen als die intrinsische Religiosität, die als verinnerlichter, verantwortlich gelebter Glaube definiert ist. Die Irrationalitätsskalen wiederum korrelieren hypothesenkonform signifikant mit der Lebenszufriedenheit. Quasiexperimentelle Extremgruppenvergleiche zwischen schwach und stark religiösen Personen erbringen für letztere signifikant erhöhte Irrationalitätswerte
- …