2,088 research outputs found
Probing Active to Sterile Neutrino Oscillations in the LENS Detector
Sterile neutrino conversion in meter scale baselines can be sensitively
probed using monoenergetic, sub-MeV, flavor pure e-neutrinos from an artificial
MCi source and the unique technology of LENS designed to oberve the low energy
solar neutrino spectrum via tagged CC e-neutrino capture in 115-In.
Active-sterile oscillations can be directly observed in the granular LENS
detector itself to critically test and extend resuls of short baseline
accelerator and reactor experiments.Comment: 4pages, 4 figures, text and figure change
Atlas: analysis tools for low-depth and ancient samples
Summary: Post-mortem damage (PMD) obstructs the proper analysis of ancient DNA samples and can currently only be addressed by removing or down-weighting potentially damaged data. Here we present ATLAS, a suite of methods to accurately genotype and estimate genetic diversity from ancient samples, while accounting for PMD. It works directly from raw BAM files and enables the building of complete and customized pipelines for the analysis of ancient and other low-depth samples in a very user-friendly way. Based on simulations we show that, in the presence of PMD, a dedicated pipeline of ATLAS calls genotypes more accurately than the state-of-the-art pipeline of GATK combined with mapDamage 2.0. Availability: ATLAS is an open- source C++ program freely available at https://bitbucket.org/phaentu/atlas
Comprehensive and highly accurate measurements of crane runways, profiles and fastenings
The process of surveying crane runways has been continually refined due to the competitive situation, modern surveying instruments, additional sensors, accessories and evaluation procedures. Guidelines, such as the International Organization for Standardization (ISO) 12488-1, define target values that must be determined by survey. For a crane runway these are for example the span, the position and height of the rails. The process has to be objective and reproducible. However, common processes of surveying crane runways do not meet these requirements sufficiently. The evaluation of the protocols, ideally by an expert, requires many years of experience. Additionally, the recording of crucial parameters, e.g., the wear of the rail, or the condition of the rail fastening and rail joints, is not regulated and for that reason are often not considered during the measurement. To solve this deficit the Advanced Rail Track Inspection System (ARTIS) was developed. ARTIS is used to measure the 3D position of crane rails, the cross-section of the crane rails, joints and, for the first time, the (crane-rail) fastenings. The system consists of a monitoring vehicle and an external tracking sensor. It makes kinematic observations with the tracking sensor from outside the rail run, e.g., the floor of an overhead crane runway, possible. In this paper we present stages of the development process of ARTIS, new target values, calibration of sensors and results of a test measurement.Federal Ministry of Economics and Energy (BMWi
Tracer Survey in the Cape Verde Region Traceraufnahme in der Kapverdenregion Cruise No. 10, Leg 1 October 31 – December 06, 2008 Ponta Delgada (Portugal) – Mindelo (Cape Verde Islands)
The research cruise MSM10/1 was extremely successful. All programs were able to collect high quality data and the anticipated goals of the expedition were fully met. We have been able to carry out the first comprehensive survey of a tracer release in the Guinea Upwelling region (GUTRE) roughly seven month after the tracer was released at 8°N 23°W in April 2008. We have estimated that a total of 40% of the tracer was found during this cruise. While the horizontal spreading and mixing was larger than anticipated, the vertical extent of the tracer found was small. The low vertical tracer spreading rate estimates are supported by the micro structure profile data. The extensive survey of the upper 1000m of the oxygen minimum zone (OMZ) allowed comparing our sections with several previous surveys. We found that the lowest oxygen values in the core of the OMZ have dropped at record low values below 40 μmol/kg. The preliminary findings from the trace metal work focused on Fe ligand measurements shows a slight higher excess ligand concentration in the surface (50m) for three stations. The two other stations show a slight decrease at this depth. A large number of biochemical samples were taken and were analyzed in Kiel for DNA and RNA diversity. The tracer release experiment provided an ideal environment for repeated biochemical sampling in the same water mass
Identifying Galactic Cosmic Ray Origins With Super-TIGER
Super-TIGER (Super Trans-Iron Galactic Element Recorder) is a new long-duration balloon-borne instrument designed to test and clarify an emerging model of cosmic-ray origins and models for atomic processes by which nuclei are selected for acceleration. A sensitive test of the origin of cosmic rays is the measurement of ultra heavy elemental abundances (Z > or equal 30). Super-TIGER is a large-area (5 sq m) instrument designed to measure the elements in the interval 30 < or equal Z < or equal 42 with individual-element resolution and high statistical precision, and make exploratory measurements through Z = 60. It will also measure with high statistical accuracy the energy spectra of the more abundant elements in the interval 14 < or equal Z < or equal 30 at energies 0.8 < or equal E < or equal 10 GeV/nucleon. These spectra will give a sensitive test of the hypothesis that microquasars or other sources could superpose spectral features on the otherwise smooth energy spectra previously measured with less statistical accuracy. Super-TIGER builds on the heritage of the smaller TIGER, which produced the first well-resolved measurements of elemental abundances of the elements Ga-31, Ge-32, and Se-34. We present the Super-TIGER design, schedule, and progress to date, and discuss the relevance of UH measurements to cosmic-ray origins
Throughflow centrality is a global indicator of the functional importance of species in ecosystems
To better understand and manage complex systems like ecosystems it is
critical to know the relative contribution of system components to system
functioning. Ecologists and social scientists have described many ways that
individuals can be important; This paper makes two key contributions to this
research area. First, it shows that throughflow, the total energy-matter
entering or exiting a system component, is a global indicator of the relative
contribution of the component to the whole system activity. It is global
because it includes the direct and indirect exchanges among community members.
Further, throughflow is a special case of Hubbell status as defined in social
science. This recognition effectively joins the concepts, enabling ecologists
to use and build on the broader centrality research in network science. Second,
I characterize the distribution of throughflow in 45 empirically-based trophic
ecosystem models. Consistent with expectations, this analysis shows that a
small fraction of the system components are responsible for the majority of the
system activity. In 73% of the ecosystem models, 20% or less of the nodes
generate 80% or more of the total system throughflow. Four or fewer dominant
nodes are required to account for 50% of the total system activity. 121 of the
130 dominant nodes in the 45 ecosystem models could be classified as primary
producers, dead organic matter, or bacteria. Thus, throughflow centrality
indicates the rank power of the ecosystems components and shows the power
concentration in the primary production and decomposition cycle. Although these
results are specific to ecosystems, these techniques build on flow analysis
based on economic input-output analysis. Therefore these results should be
useful for ecosystem ecology, industrial ecology, the study of urban
metabolism, as well as other domains using input-output analysis.Comment: 7 figures, 2 table
Possible Detection of Large Solar Particle Event at Balloon Altitudes during the 2001-2002 TIGER Flight
The Trans-Iron Galactic Element Recorder (TIGER) was launched on December 21, 2001 and flew for about 32 days on a long-duration balloon mission from McMurdo Base in Antarctica. On December 26, 2001 at about 5:30 UT, a
ground-level solar particle event (M7.6 flare) was observed by a number of neutron monitors. The SIS instrument aboard the ACE spacecraft measured the elemental composition and particle energy spectra up to ∼150MeV/nuc. While not designed to operate under such conditions, TIGER data for the same period show interesting variations in the count rate and composition of the measured particles that may be related to the detection of heavy Solar particles (Si to Fe)
in the ∼GeV/nuc range. We discuss the TIGER observations in relation to other available data from this event
Ultra-heavy cosmic-ray science--Are r-process nuclei in the cosmic rays produced in supernovae or binary neutron star mergers?
The recent detection of 60Fe in the cosmic rays provides conclusive evidence
that there is a recently synthesized component (few MY) in the GCRs (Binns et
al. 2016). In addition, these nuclei must have been synthesized and accelerated
in supernovae near the solar system, probably in the Sco-Cen OB association
subgroups, which are about 100 pc distant from the Sun. Recent theoretical work
on the production of r-process nuclei appears to indicate that it is difficult
for SNe to produce the solar system abundances relative to iron of r-process
elements with high atomic number (Z), including the actinides (Th, U, Np, Pu,
and Cm). Instead, it is believed by many that the heaviest r-process nuclei, or
perhaps even all r-process nuclei, are produced in binary neutron star mergers.
Since we now know that there is at least a component of the GCRs that has been
recently synthesized and accelerated, models of r-process production by SNe and
BNSM can be tested by measuring the relative abundances of these ultra-heavy
r-process nuclei, and especially the actinides, since they are radioactive and
provide clocks that give the time interval from nucleosynthesis to detection at
Earth. Since BNSM are believed to be much less frequent in our galaxy than SNe
(roughly 1000 times less frequent, the ratios of the actinides, each with their
own half-life, will enable a clear determination of whether the heaviest
r-process nuclei are synthesized in SNe or in BNSM. In addition, the r-process
nuclei for the charge range from 34 to 82 can be used to constrain models of
r-process production in BNSM and SNe. Thus, GCRs become a multi-messenger
component in the study of BNSM and SNe.Comment: Astro2020 Science White Pape
Equivalence of the realized input and output oriented indirect effects metrics in ecological network analysis
A new understanding of the consequences of how ecosystem elements are
interconnected is emerging from the development and application of Ecological
Network Analysis. The relative importance of indirect effects is central to
this understanding, and the ratio of indirect flow to direct flow (I/D) is one
indicator of their importance. Two methods have been proposed for calculating
this indicator. The unit approach shows what would happen if each system member
had a unit input or output, while the realized technique determines the ratio
using the observed system inputs or outputs. When using the unit method, the
input oriented and output oriented ratios can be different, potentially leading
to conflicting results. However, we show that the input and output oriented I/D
ratios are identical using the realized method when the system is at steady
state. This work is a step in the maturation of Ecological Network Analysis
that will let it be more readily testable empirically and ultimately more
useful for environmental assessment and management.Comment: 13 pages, 1 figure, 1 tabl
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