3,359 research outputs found
Mobile Communication Signatures of Unemployment
The mapping of populations socio-economic well-being is highly constrained by
the logistics of censuses and surveys. Consequently, spatially detailed changes
across scales of days, weeks, or months, or even year to year, are difficult to
assess; thus the speed of which policies can be designed and evaluated is
limited. However, recent studies have shown the value of mobile phone data as
an enabling methodology for demographic modeling and measurement. In this work,
we investigate whether indicators extracted from mobile phone usage can reveal
information about the socio-economical status of microregions such as districts
(i.e., average spatial resolution < 2.7km). For this we examine anonymized
mobile phone metadata combined with beneficiaries records from unemployment
benefit program. We find that aggregated activity, social, and mobility
patterns strongly correlate with unemployment. Furthermore, we construct a
simple model to produce accurate reconstruction of district level unemployment
from their mobile communication patterns alone. Our results suggest that
reliable and cost-effective economical indicators could be built based on
passively collected and anonymized mobile phone data. With similar data being
collected every day by telecommunication services across the world,
survey-based methods of measuring community socioeconomic status could
potentially be augmented or replaced by such passive sensing methods in the
future
Exoplanet Catalogues
One of the most exciting developments in the field of exoplanets has been the
progression from 'stamp-collecting' to demography, from discovery to
characterisation, from exoplanets to comparative exoplanetology. There is an
exhilaration when a prediction is confirmed, a trend is observed, or a new
population appears. This transition has been driven by the rise in the sheer
number of known exoplanets, which has been rising exponentially for two decades
(Mamajek 2016). However, the careful collection, scrutiny and organisation of
these exoplanets is necessary for drawing robust, scientific conclusions that
are sensitive to the biases and caveats that have gone into their discovery.
The purpose of this chapter is to discuss and demonstrate important
considerations to keep in mind when examining or constructing a catalogue of
exoplanets. First, we introduce the value of exoplanetary catalogues. There are
a handful of large, online databases that aggregate the available exoplanet
literature and render it digestible and navigable - an ever more complex task
with the growing number and diversity of exoplanet discoveries. We compare and
contrast three of the most up-to-date general catalogues, including the data
and tools that are available. We then describe exoplanet catalogues that were
constructed to address specific science questions or exoplanet discovery space.
Although we do not attempt to list or summarise all the published lists of
exoplanets in the literature in this chapter, we explore the case study of the
NASA Kepler mission planet catalogues in some detail. Finally, we lay out some
of the best practices to adopt when constructing or utilising an exoplanet
catalogue.Comment: 14 pages, 6 figures. Invited review chapter, to appear in "Handbook
of Exoplanets", edited by H.J. Deeg and J.A. Belmonte, section editor N.
Batalh
Confirmation of low genetic diversity and multiple breeding females in a social group of Eurasian badgers from microsatellite and field data
The Eurasian badger (
Meles meles
) is a facultatively social carnivore that shows only rudimentary
co-operative behaviour and a poorly defined social hierarchy. Behavioural evidence
and limited genetic data have suggested that more than one female may breed in a
social group. We combine pregnancy detection by ultrasound and microsatellite locus
scores from a well-studied badger population from Wytham Woods, Oxfordshire, UK, to
demonstrate that multiple females reproduce within a social group. We found that at least
three of seven potential mothers reproduced in a group that contained 11 reproductive age
females and nine offspring. Twelve primers showed variability across the species range and only five of these were variable in Wytham. The microsatellites showed a reduced repeat number, a significantly higher number of nonperfect repeats, and moderate heterozygosity
levels in Wytham. The high frequency of imperfect repeats and demographic phenomena might be responsible for the reduced levels of variability observed in the badger
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State of the California current 2013-14: El niño looming
In 2013, the California current was dominated by strong coastal upwelling and high productivity. Indices of total cumulative upwelling for particular coastal locations reached some of the highest values on record. Chlorophyll a levels were high throughout spring and summer. Catches of upwelling-related fish species were also high. After a moderate drop in upwelling during fall 2013, the California current system underwent a major change in phase. Three major basin-scale indicators, the PDO, the NPGO, and the ENSO-MEI, all changed phase at some point during the winter of 2013/14. The PDO changed to positive values, indicative of warmer waters in the North Pacific; the NPGO to negative values, indicative of lower productivity along the coast; and the MEI to positive values, indicative of an oncoming El Niño. Whereas the majority of the California Current system appears to have transitioned to an El Niño state by August 2014, based on decreases in upwelling and chlorophyll a concentration, and increases in SST, there still remained pockets of moderate upwelling, cold water, and high chlorophyll a biomass at various central coast locations, unlike patterns seen during the more major El Niños (e.g., the 97-98 event). Catches of rockfish, market squid, euphausiids, and juvenile sanddab remained high along the central coast, whereas catches of sardine and anchovy were low throughout the CCS. 2014 appears to be heading towards a moderate El Niño state, with some remaining patchy regions of upwellingdriven productivity along the coast. Superimposed on this pattern, three major regions have experienced possibly non-El Niño-related warming since winter: the Bering Sea, the Gulf of Alaska, and offshore of southern California. It is unclear how this warming may interact with the predicted El Niño, but the result will likely be reduced growth or reproduction for many key fisheries species
Ultra-stiff metallic glasses through bond energy density design
The elastic properties of crystalline metals scale with their valence electron density. Similar observations have been made for metallic glasses. However, for metallic glasses where covalent bonding predominates, such as metalloid metallic glasses, this relationship appears to break down. At present, the reasons for this are not understood. Using high energy x-ray diffraction analysis of melt spun and thin film metallic glasses combined with density functional theory based molecular dynamics simulations, we show that the physical origin of the ultrahigh stiffness in both metalloid and non-metalloid metallic glasses is best understood in terms of the bond energy density. Using the bond energy density as novel materials design criterion for ultra-stiff metallic glasses, we are able to predict a CoTaB short range ordered material by density functional theory based molecular dynamics simulations with a high bond energy density of 0.94 eV Å and a bulk modulus of 263 GPa, which is 17% greater than the stiffest Co-B based metallic glasses reported in literature.The authors acknowledge support by the German National Science Foundation (DFG) within the SPP-1594. Simulations were performed with computing resources granted by JARA-HPC from RWTH Aachen University under project JARA0131. Parts of this research were carried out at the light source PETRA III (beamline P02.1) at DESY, a member of the Helmholtz Association (HGF). WJC also acknowledges the support of the EPSRC/Rolls-Royce Strategic Partnership (EP/M005607/1)
The completed SDSS-IV extended baryon oscillation spectroscopic survey: Geometry and growth from the anisotropic void-galaxy correlation function in the luminous red galaxy sample
We present an analysis of the anisotropic redshift-space void-galaxy correlation in configuration space using the Sloan Digital Sky Survey extended Baryon Oscillation Spectroscopic Survey (eBOSS) Data Release 16 luminous red galaxy (LRG) sample. This sample consists of LRGs between redshifts 0.6 and 1.0, combined with the high redshift z > 0.6 tail of the Baryon Oscillation Spectroscopic Survey Data Release 12 CMASS sample. We use a reconstruction method to undo redshift-space distortion (RSD) effects from the galaxy field before applying a watershed void-finding algorithm to remove bias from the void selection. We then perform a joint fit to the multipole moments of the correlation function for the growth rate fσ 8 and the geometrical distance ratio DM/DH, finding f σ8 (zeff ) = 0.356 ± 0.079 and DM /DH (zeff ) = 0.868 ± 0.017 at the effective redshift zeff = 0.69 of the sample. The posterior parameter degeneracies are orthogonal to those from galaxy clustering analyses applied to the same data, and the constraint achieved on DM/DH is significantly tighter. In combination with the consensus galaxy BAO and full-shape analyses of the same sample, we obtain fσ 8 = 0.447 ± 0.039, DM/rd = 17.48 ± 0.23, and DH/rd = 20.10 ± 0.34. These values are in good agreement with the ΛCDM model predictions and represent reductions in the uncertainties of 13 per cent, 23 per cent, and 28 per cent, respectively, compared to the combined results from galaxy clustering, or an overall reduction of 55 per cent in the allowed volume of parameter space
Recurrent hemarthrosis after total knee arthroplasty
This report describes a case of spontaneous recurrent hemarthrosis of the knee that presented 4 weeks after total knee arthroplasty. Femoral arteriography showed a false aneurysm of a branch of the inferior lateral geniculate artery. Therapeutic embolization of the arterial branch was performed using three platinum coils with good clinical result and good knee joint function. Hemarthrosis has not recurred since embolization
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State of the California current 2012-13: No such thing as an “average” year
This report reviews the state of the California Current System (CCS) between winter 2012 and spring 2013, and includes observations from Washington State to Baja California. During 2012, large-scale climate modes indicated the CCS remained in a cool, productive phase present since 2007. The upwelling season was delayed north of 42°N, but regions to the south, especially 33° to 36°N, experienced average to above average upwelling that persisted throughout the summer. Contrary to the indication of high production suggested by the climate indices, chlorophyll observed from surveys and remote sensing was below average along much of the coast. As well, some members of the forage assemblages along the coast experienced low abundances in 2012 surveys. Specifically, the concentrations of all lifestages observed directly or from egg densities of Pacific sardine, Sardinops sagax, and northern anchovy, Engraulis mordax, were less than previous years’ survey estimates. However, 2013 surveys and observations indicate an increase in abundance of northern anchovy. During winter 2011/2012, the increased presence of northern copepod species off northern California was consistent with stronger southward transport. Krill and small-fraction zooplankton abundances, where examined, were generally above average. North of 42°N, salps returned to typical abundances in 2012 after greater observed concentrations in 2010 and 2011. In contrast, salp abundance off central and southern California increased after a period of southward transport during winter 2011/2012. Reproductive success of piscivorous Brandt’s cormorant, Phalacrocorax penicillatus, was reduced while planktivorous Cassin’s auklet, Ptychoramphus aleuticus was elevated. Differences between the productivity of these two seabirds may be related to the available forage assemblage observed in the surveys. California sea lion pups from San Miguel Island were undernourished resulting in a pup mortality event perhaps in response to changes in forage availability. Limited biological data were available for spring 2013, but strong winter upwelling coastwide indicated an early spring transition, with the strong upwelling persisting into early summer
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