2,915 research outputs found
Pinguicula rosmarieae Casper, Bussmann & T.Henning (Lentibulariaceae), a new butterwort from the Amotape-Huancabamba Zone (northern Peru)
The insectivorous genus Pinguicula occurs along the whole Andean mountain chain from Colombia-Venezuela in the north to Tierra del Fuego in the south with a short interruption in the Peruvian-Chilean desert range. This paper describes a new and striking species of Pinguicula that occurs in the south-eastern part of the Amotape-Huancabamba Zone in north Peru. It grows either as a lithophyte on moist rocks or as an epiphyte on Polylepis multijuga Pilg. in the wet highlands of the Cordillera Central. Pinguicula rosmarieae Casper, Bussmann & T.Henning, sp. nov. is clearly distinguished by a basal rosette of ovate-obovate leaves spread out flat on the ground and especially by a two-partite corolla with a straight uniform tube-spur complex, two features unknown from other Andean Pinguicula species. The morphological similarity to P. calyptrata Kunth is discussed and the habitat and distribution of P. rosmarieae are characterised
Internationale Direktinvestitionen : Determinanten und Konsequenzen fĂŒr den Standort Deutschland
Internationale Direktinvestitionen sind zum wichtigsten Motor der Globalisierung geworden. WĂ€hrend sich die westdeutschen Exporte seit 1980 etwa verdoppelten, stiegen die auslĂ€ndischen DirektinvestitionsbestĂ€nde deutscher Unternehmen im gleichen Zeitraum auf das Vierfache an. Die Zahl der BeschĂ€ftigten in auslĂ€ndischen Industrieunternehmen mit deutscher Beteiligung liegt derzeit bei 1,7 Millionen; das entspricht mehr als 20 vH der inlĂ€ndischen IndustriebeschĂ€ftigung. Das primĂ€re Ziel von Direktinvestitionen liegt in der Ausnutzung unternehmensspezifischer GröĂenvorteile auf auslĂ€ndischen AbsatzmĂ€rkten. Dementsprechend liegt das regionale Schwergewicht der deutschen Direktinvestitionen in IndustrielĂ€ndern und das sektorale Schwergewicht bei jenen Branchen, die ĂŒberdurchschnittlich exportintensiv sind und auch im Inland ĂŒber eine vergleichsweise starke Marktposition verfĂŒgen. Dazu zĂ€hlen vor allem die Chemische Industrie, der StraĂenfahrzeugbau und die Elektrotechnik. Das auĂerordentlich niedrige Niveau auslĂ€ndischer Direktinvestitionen in Deutschland hat vielfĂ€ltige Ursachen: Erstens dĂŒrften die im internationalen Vergleich stark gestiegenen Arbeitskosten viele Auslandsunternehmen dazu veranlaĂt haben, ihre BrĂŒckenköpfe zur ErschlieĂung der europĂ€ischen AbsatzmĂ€rkte in anderen EU-LĂ€ndern zu errichten. Zweitens wird der Erwerb deutscher Unternehmensbeteiligungen durch den niedrigen Börsenkapitalisierungsgrad und die traditionell einfluĂreiche Rolle der Hausbanken bei der Unternehmensfinanzierung erschwert. Und drittens behindert die hohe Regulierungsdichte im deutschen Dienstleistungssektor das Investitionsengagement auslĂ€ndischer Unternehmen gerade in jenen Branchen, die eigentlich das gröĂte Potential fĂŒr einflieĂende Direktinvestitionsströme bieten. Der Saldo der Direktinvestitionen stellt fĂŒr sich genommen keinen verlĂ€Ălichen Indikator fĂŒr die StandortqualitĂ€t eines Landes dar. So weisen fĂŒr die achtziger und frĂŒhen neunziger Jahre neben Deutschland zahlreiche andere EU-LĂ€nder (darunter auch GroĂbritannien) ein Defizit in der Direktinvestitionsbilanz aus, ohne daĂ all diesen LĂ€ndern eine pauschale StandortschwĂ€che bescheinigt werden mĂŒĂte. Auch in Japan ist das Defizit in der Direktinvestitionsbilanz nicht erst mit der Wirtschaftskrise der neunziger Jahre aufgetreten, sondern war auch schon in den wachstumsstarken Jahrzehnten zuvor zu verzeichnen, wĂ€hrend die Vereinigten Staaten sowohl in wachstumsstarken als auch in wachstumsschwachen Perioden traditionell einen ĂberschuĂ bei den auslĂ€ndischen Direktinvestitionen im Inland aufweisen. Wie attraktiv ein Land fĂŒr international mobile Kapitalanleger ist, kommt besser in den gesamten Pro-Kopf-Investitionen zum Ausdruck. Nach diesem Indikator hat sich die Position Westdeutschlands gegenĂŒber anderen IndustrielĂ€ndern lĂ€ngerfristig kaum verĂ€ndert. Insgesamt tragen sowohl die deutschen Direktinvestitionen im Ausland als auch die auslĂ€ndischen Direktinvestitionen im Inland maĂgeblich zur Vertiefung der internationalen Arbeitsteilung bei. Sie verschĂ€rfen zwar den Anpassungsdruck im weltweiten Strukturwandel, bieten aber auch die Chance, Wachstum und Wohlstand durch âgains from globalization" zu steigern. --
A comprehensive examination of the Eps Eri system -- Verification of a 4 micron narrow-band high-contrast imaging approach for planet searches
Due to its proximity, youth, and solar-like characteristics with a spectral
type of K2V, Eps Eri is one of the most extensively studied systems in an
extrasolar planet context. Based on radial velocity, astrometry, and studies of
the structure of its circumstellar debris disk, at least two planetary
companion candidates to Eps Eri have been inferred in the literature (Eps Eri
b, Eps Eri c). Some of these methods also hint at additional companions
residing in the system. Here we present a new adaptive optics assisted
high-contrast imaging approach that takes advantage of the favourable planet
spectral energy distribution at 4 microns, using narrow-band angular
differential imaging to provide an improved contrast at small and intermediate
separations from the star. We use this method to search for planets at orbits
intermediate between Eps Eri b (3.4 AU) and Eps Eri c (40 AU). The method is
described in detail, and important issues related to the detectability of
planets such as the age of Eps Eri and constraints from indirect measurements
are discussed. The non-detection of companion candidates provides stringent
upper limits for the masses of additional planets. Using a combination of the
existing dynamic and imaging data, we exclude the presence of any planetary
companion more massive than 3 Mjup anywhere in the Eps Eri system.
Specifically, with regards to the possible residual linear radial velocity
trend, we find that it is unlikely to correspond to a real physical companion
if the system is as young as 200 Myr, whereas if it is as old as 800 Myr, there
is an allowed semi-major axis range between about 8.5 and 25 AU.Comment: 11 pages, 8 figures, A&A accepte
Two-Dimensional Tomographic Simultaneous Multi-Species VisualizationâPart I: Experimental Methodology and Application to Laminar and Turbulent Flames
In recent years, the tomographic visualization of laminar and turbulent flames has received much attention due to the possibility of observing combustion processes on-line and with high temporal resolution. In most cases, either the spectrally non-resolved flame luminescence or the chemiluminescence of a single species is detected and used for the tomographic reconstruction. In this work, we present a novel 2D emission tomographic setup that allows for the simultaneous detection of multiple species (e.g., OH*, CH* and soot but not limited to these) using a single image intensified CCD camera. We demonstrate the simultaneous detection of OH* (310 nm), CH* (430 nm) and soot (750 nm) in laminar methane/air, as well as turbulent methane/air and ethylene/air diffusion flames. As expected, the reconstructed distributions of OH* and CH* in laminar and turbulent flames are highly correlated, which supports the feasibility of tomographic measurements on these kinds of flames and at timescales down to about 1 ms. In addition, the possibilities and limitations of the tomographic approach to distinguish between locally premixed, partially premixed and non-premixed conditions, based on evaluating the local intensity ratio of OH* and CH* is investigated. While the tomographic measurements allow a qualitative classification of the combustion conditions, a quantitative interpretation of instantaneous reconstructed intensities (single shot results) has a much greater uncertainty
The young binary HD 102077: Orbit, spectral type, kinematics, and moving group membership
The K-type binary star HD 102077 was proposed as a candidate member of the TW
Hydrae Association (TWA) which is a young (5-15 Myr) moving group in close
proximity (~50 pc) to the solar system. The aim of this work is to verify this
hypothesis by different means. We first combine diffraction-limited
observations from the ESO NTT 3.5m telescope in SDSS-i' and -z' passbands and
ESO 3.6m telescope in H-band with literature data to obtain a new, amended
orbit fit, estimate the spectral types of both components, and reanalyse the
Hipparcos parallax and proper motion taking the orbital motion into account.
Moreover, we use two high-resolution spectra of HD 102077 obtained with the
fibre-fed optical echelle spectrograph FEROS at the MPG/ESO 2.2m telescope to
determine the radial velocity and the lithium equivalent width of the system.
The trajectory of HD 102077 is well constrained and we derive a total system
mass of M and a semi-major axis of AU. From the i'-z' colours we infer an integrated spectral type of K2V,
and individual spectral types of K0 +/- 1 and K5 +/- 1. The radial velocity
corrected for the orbital motion of the system is km/s. Even
though the parallax determination from the Hipparcos data is not influenced by
the orbital motion, the proper motion changes to mas/yr and mas/yr. With
the resultant space motion, the probability of HD 102077 being a member of TWA
is less than 1%. Furthermore, the lithium equivalent width of m\AA
is consistent with an age between 30 Myr and 120 Myr and thus older than
the predicted age of TWA. In conclusion, HD 102077's age, galactic space
motion, and position do not fit TWA or any other young moving group
Interplay between Kondo effect and Ruderman-Kittel-Kasuya-Yosida interaction
The interplay between the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction
and the Kondo effect is expected to provide the driving force for the emergence
of many phenomena in strongly correlated electron materials. Two magnetic
impurities in a metal are the smallest possible system containing all these
ingredients and define a bottom up approach towards a long term understanding
of concentrated / dense systems. Here we report on the experimental and
theoretical investigation of iron dimers buried below a Cu(100) surface by
means of low temperature scanning tunnelling spectroscopy (STS) combined with
density functional theory (DFT) and numerical renormalization group (NRG)
calculations. The Kondo effect, in particular the width of the Abrikosov-Suhl
resonance, is strongly altered or even suppressed due to magnetic coupling
between the impurities. It oscillates as function of dimer separation revealing
that it is related to the RKKY interaction mediated by the conduction
electrons. Simulations based on density functional theory support this concept
showing the same oscillation period and trends in the coupling strength as
found in the experiment
User Guide for CMSY++
CMSY++ is an advanced state-space Bayesian method for stock assessment that estimates fisheries reference points (MSY, Fmsy, Bmsy) as well as status or relative stock size (B/Bmsy) and fishing pressure or exploitation (F/Fmsy) from catch and (optionally) abundance data, a prior for resilience or productivity (r), and broad priors for the ratio of biomass to unfished biomass (B/k) at the beginning, an intermediate year, and the end of the time series. For the purpose of this User Guide, the whole package is referred to as CMSY++ whereas the part of the method that deals with catch-only data is referred to as CMSY (catch MSY), and the part of the method that requires additional abundance data is referred to as BSM (Bayesian Schaefer Model). Both methods are based on a modified Schaefer surplus production model (see paper cited above for more details). The main advantage of BSM, compared to other implementations of surplus production models, is the focus on informative priors and the acceptance of short and incomplete (i.e., fragmented, with missing years) abundance data. This document provides a simple step-by-step guide for researchers who want to apply CMSY++ to their own data
Nesting in bark â the peculiar life history of the rare boreoalpine osmiine bee Osmia (Melanosmia) nigriventris (Hymenoptera, Megachilidae)
Osmia (Melanosmia) nigriventris (Zetterstedt) is a predominantly boreoalpine megachilid bee species, whose biology is poorly known due to its pronounced rarity all over Central Europe. The discovery of 19 nests in the Grisons and Valais (Switzerland) allowed for the investigation of its nesting biology and prompted the assessment of the speciesâ host-plant spectrum, phenology and distribution. All nests were in thick bark pieces of Larixdecidua, which lay in grassy vegetation on sun-exposed ground of open subalpine forests dominated by larch. The nests contained 1â26 brood cells constructed within one to several burrows tunneled out by the female bees with their specialized mandibles, which are distinctly stronger than those of related O. (Melanosmia) species known to nest in preexisting cavities or loose soil. The linearly arranged brood cells were separated from each other by three-layered partitions consisting of an interlayer of densely packed small bark particles sandwiched between two thin layers of chewed green leaves (âleaf pulpâ). DNA metabarcoding of several nest plugs revealed that Potentilla (Rosaceae) and Helianthemum (Cistaceae) served as source of the leaf pulp. Anthraxanthrax (Bombyliidae) and Sapygasimilis (Sapygidae) parasitized the brood cells of O.nigriventris as shown by DNA barcoding of prepupae overwintering in the hostâs nests. O.nigriventris is mesolectic and harvests pollen almost exclusively on Fabaceae (e.g. Lotus, Hippocrepis), Ericaceae (Rhododendron, Vaccinium) and Cistaceae (Helianthemum). Depending on the altitude, O.nigriventris emerges from the beginning of May to the first decade of June and thus qualifies as an early flying bee active in spring and early summer similar to the other European O. (Melanosmia) species. It likely needs two years for its development in the subalpine zone of the Alps and overwinters as prepupa in the first and probably as imago in the second winter. O.nigriventris has a Holarctic distribution, its disjunct Palaearctic range encompasses the boreal zone from Scandinavia eastwards to the Russian Far East, the Caucausus, the Alps as well as scattered locations at lower altitudes throughout Central Europe, where it is regarded as a glacial relict and has probably suffered strong declines during the last decades
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