475 research outputs found

    The effect of cave illumination on bats

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    Artificial light at night has large impacts on nocturnal wildlife such as bats, yet its effect varies with wavelength of light, context, and across species involved. Here, we studied in two experiments how wild bats of cave-roosting species (Rhinolophus mehelyi, R. euryale, Myotis capaccinii and Miniopterus schreibersii) respond to LED lights of different colours. In dual choice experiments, we measured the acoustic activity of bats in response to neutral-white, red or amber LED at a cave entrance and in a flight room – mimicking a cave interior. In the flight room, M. capaccinii and M. schreibersii preferred red to white light, but showed no preference for red over amber, or amber over white light. In the cave entrance experiment, all light colours reduced the activity of all emerging species, yet red LED had the least negative effect. Rhinolophus species reacted most strongly, matching their refusal to fly at all under any light treatment in the flight room. We conclude that the placement and light colour of LED light should be considered carefully in lighting concepts for caves both in the interior and at the entrance. In a cave interior, red LED light could be chosen – if needed at all – for careful temporary illumination of areas, yet areas important for bats should be avoided based on the precautionary principle. At cave entrances, the high sensitivity of most bat species, particularly of Rhinolophus spp., towards light sources almost irrespective of colour, calls for utmost caution when illuminating cave entrances

    Fractional Fokker-Planck Equations for Subdiffusion with Space-and-Time-Dependent Forces

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    We have derived a fractional Fokker-Planck equation for subdiffusion in a general space-and- time-dependent force field from power law waiting time continuous time random walks biased by Boltzmann weights. The governing equation is derived from a generalized master equation and is shown to be equivalent to a subordinated stochastic Langevin equation.Comment: 5 page

    First-principles study of Co- and Cu-doped Ni2MnGa along the tetragonal deformation path

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    The influence of Co and Cu doping on Ni-Mn-Ga Heusler alloy is investigated using the first-principles exact muffin-tin orbital method in combination with the coherent-potential approximation. Single-element doping and simultaneous doping by both elements are investigated in Ni50−xCoxMn25−yGa25−zCuy+z alloys, with dopant concentrations x,y, and z up to 7.5 at. %. Doping with Co in the Ni sublattice decreases the (c/a)NM ratio of the nonmodulated (NM) martensite, but it simultaneously increases the cubic phase stability with respect to the NM phase. Doping with Cu in the Mn or in Ga sublattices does not change the (c/a)NM ratio significantly and it decreases the cubic phase stability. For simultaneous doping by Co in the Ni sublattice and Cu in the Mn or Ga sublattices, the effects of the individual dopants are independent and about the same as for the single-element doping. Thus, the (c/a)NM ratio can be adjusted by Co doping while the phase stability can be balanced by Cu doping, resulting in stable martensite with a reduced (c/a)NM. The local stability of the cubic phase with respect to the tetragonal deformation can be understood on the basis of a density-of-states analysis.Peer reviewe

    Possible Signatures of a Cold-Flow Disk from MUSE using a z=1 galaxy--quasar pair towards SDSSJ1422-0001

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    We use a background quasar to detect the presence of circum-galactic gas around a z=0.91z=0.91 low-mass star forming galaxy. Data from the new Multi Unit Spectroscopic Explorer (MUSE) on the VLT show that the host galaxy has a dust-corrected star-formation rate (SFR) of 4.7±\pm0.2 Msun/yr, with no companion down to 0.22 Msun/yr (5 σ\sigma) within 240 kpc (30"). Using a high-resolution spectrum (UVES) of the background quasar, which is fortuitously aligned with the galaxy major axis (with an azimuth angle α\alpha of only 1515^\circ), we find, in the gas kinematics traced by low-ionization lines, distinct signatures consistent with those expected for a "cold flow disk" extending at least 12 kpc (3×R1/23\times R_{1/2}). We estimate the mass accretion rate M˙in\dot M_{\rm in} to be at least two to three times larger than the SFR, using the geometric constraints from the IFU data and the HI column density of logNHI20.4\log N_{\rm HI} \simeq 20.4 obtained from a {\it HST}/COS NUV spectrum. From a detailed analysis of the low-ionization lines (e.g. ZnII, CrII, TiII, MnII, SiII), the accreting material appears to be enriched to about 0.4 ZZ_\odot (albeit with large uncertainties: logZ/Z=0.4 ± 0.4\log Z/Z_\odot=-0.4~\pm~0.4), which is comparable to the galaxy metallicity (12+logO/H=8.7±0.212+\log \rm O/H=8.7\pm0.2), implying a large recycling fraction from past outflows. Blue-shifted MgII and FeII absorptions in the galaxy spectrum from the MUSE data reveal the presence of an outflow. The MgII and FeII doublet ratios indicate emission infilling due to scattering processes, but the MUSE data do not show any signs of fluorescent FeII* emission.Comment: 17 pages, 11 figures, in press (ApJ), minor edits after the proofs. Data available at http://muse-vlt.eu/science/j1422

    An Indication of African Catfish's (Clarias Gariepinus) Behavioral Changes as a Response for Increased Seismic Activity

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    This report was aimed to describe the behavioral changes of catfish as observed before two different earthquakes hit the Province of Aceh, Indonesia in year of 2012. A number of 5 African's catfish (Clarias gariepinus) were placed in an aquarium located in Gapang, Sukakarya Sub-district of Sabang Town, Aceh. Their behavior activities were observed manually at three different times (08.00 AM, 01.00 PM, and 05.00 PM) every day from 1st March up to 11th April 2012. The result of observation showed that the activity of catfish was different between all of them from 1st March 2012 up to morning observation on 11th April 2012. Most of those activities was not showed as very active behavior. However, their behavior was very active in the same pattern when observed at noon and afternoon times on 11 April 2012. On this date, there were two consecutive earthquakes happened at magnitude of >8 Richter Scale at 03.38 PM and 05.43 PM. The epicenter of this earthquake was in Simeulue, with the distance of more and less of 390 km from observation station of catfish in Gapang. It was noted that this abnormal behavior possibly showed as an indication of their ability to detect the increase of pre-seismic activity at 2.38 hours and 43 minutes before the two earthquakes. Perhaps, it is the result of their response to the increase of pre-seismic electromagnetic wave. Further continuous observation and research is needed to ensure the role of African's catfish (Clarias gariepinus) as abio-sensor for the increase of seismic activity

    Genetic analysis of long-lived families reveals novel variants influencing high density-lipoprotein cholesterol

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    The plasma levels of high-density lipoprotein cholesterol (HDL) have an inverse relationship to the risks of atherosclerosis and cardiovascular disease, and have also been associated with longevity. We sought to identify novel loci for HDL that could potentially provide new insights into biological regulation of HDL metabolism in healthy-longevous subjects. We performed a genome-wide association scan on HDL using a mixed model approach to account for family structure using kinship coefficients. A total of 4,114 subjects of European descent (480 families) were genotyped at ~2.3 million SNPs and ~38 million SNPs were imputed using the 1000 Genome Cosmopolitan reference panel in MACH. We identified novel variants near-NLRP1 (17p13) associated with an increase of HDL levels at genome-wide significant level (p< 5.0E-08). Additionally, several CETP (16q21) and ZNF259-APOA5-A4-C3-A1 (11q23.3) variants associated with HDL were found, replicating those previously reported in the literature. A possible regulatory variant upstream of NLRP1 that is associated with HDL in these elderly LLFS subjects may also contribute to their longevity and health. Our NLRP1 intergenic SNPs show a potential regulatory function in ENCODE; however, it is not clear whether they regulate NLRP1 or other more remote gene. NLRP1 plays an important role in the induction of apoptosis, and its inflammasome is critical for mediating innate immune responses. Nlrp1a (a mouse ortholog of human NLRP1) interacts with SREBP-1a (17p11) which has a fundamental role in lipid concentration and composition, and is involved in innate immune response in macrophages. The NLRP1 region is conserved in mammals, but also has evolved adaptively showing signals of positive selection in European populations that might confer an advantage. NLRP1 intergenic SNPs have also been associated with immunity/inflammasome disorders which highlights the biological importance of this chromosomal region

    Current Issues in Asteroseismology

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    In this contribution we briefly review some of the current issues and promises for the future by asteroseismology. We are entering a new phase in this field driven by the wealth of data that has been collected and data that will soon be available for asteroseismology across the HR Diagram. Major difficulties in the descriptions of stellar interiors that arose in the second half of the 20th century may now be in part addressed and solved (this is the expectation!) by asteroseismology with unprecedented precision. In this contribution we list some of the key open questions in stellar physics, the seismic data we expect to collect in the near future, and some techniques that will provide the tools to connect data and models.Comment: 9 pages, 2 figures - to appear in Helioseismology, Asteroseismology and MHD Connections, (Eds) L. Gizon et al., Journal of Physics Conference Series, 2008 [Revision 1 - english; Revision 2 - references

    Asteroseismology and interferometry of the red giant star epsilon Oph

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    The GIII red giant star epsilon Oph has been found to exhibit several modes of oscillation by the MOST mission. We interpret the observed frequencies of oscillation in terms of theoretical radial p-mode frequencies of stellar models. Evolutionary models of this star, in both shell H-burning and core He-burning phases of evolution, are constructed using as constraints a combination of measurements from classical ground-based observations (for luminosity, temperature, and chemical composition) and seismic observations from MOST. Radial frequencies of models in either evolutionary phase can reproduce the observed frequency spectrum of epsilon Oph almost equally well. The best-fit models indicate a mass in the range of 1.85 +/- 0.05 Msun with radius of 10.55 +/- 0.15 Rsun. We also obtain an independent estimate of the radius of epsilon Oph using high accuracy interferometric observations in the infrared K' band, using the CHARA/FLUOR instrument. The measured limb darkened disk angular diameter of epsilon Oph is 2.961 +/- 0.007 mas. Together with the Hipparcos parallax, this translates into a photospheric radius of 10.39 +/- 0.07 Rsun. The radius obtained from the asteroseismic analysis matches the interferometric value quite closely even though the radius was not constrained during the modelling.Comment: 11 pages, accepted for publication in Astronomy & Astrophysic
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