bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nighttime sensitivity of ionospheric VLF measurements to X‐ray bursts from a remote cosmic source
Authors: Raulin Jean‐Pierre , Trottet Gérard , Giménez de Castro C. Guillermo , Correia Emilia , Macotela E. Liliana 
Published: May 2014

AbstractOn 22 January 2009, a series of X‐ray bursts were emitted by the soft gamma ray repeater SGR J1550‐5418. Some of these bursts produced enhanced ionization in the nighttime lower ionosphere. These ionospheric disturbances were studied using X‐ray measurements from the Anti‐Coincidence Shield of the Spectrometer for Integral onboard the International Gamma‐Ray Astrophysics Laboratory and simultaneous phase and amplitude records from two VLF propagation paths between the transmitter Naval Radio Station, Pearl Harbor (Hawaii) and the receivers Radio Observatorio do Itapetinga (Brazil) and Estação Antarctica Commandante Ferraz (Antarctic Peninsula). The VLF measurements have been obtained with an unprecedented high time resolution of 20 ms. We find that the illumination factor I (illuminated path length times the cosine of the zenith angle), which characterizes the propagation paths underlying the flaring object, is a key parameter which determines the sensitivity threshold of the VLF detection of X‐ray bursts from nonsolar transients. For the present VLF measurements of bursts from SGR J1550‐5418, it is found that for I ≥ 1.8 Mm, all X‐ray bursts with fluence in the 25 keV to 2 MeV range larger than F25_min ~ 1.0 × 10−6 erg/cm2 produce a measurable ionospheric disturbance. Such a lower limit of the X‐ray fluence value indicates that moderate X‐ray bursts, as opposed to giant X‐ray bursts, do produce ionospheric disturbances larger than the sensitivity limit of the VLF technique. Therefore, the frequency of detection of such events could be improved, for example by increasing the coverage of existing VLF receiving networks. The VLF detection of high‐energy astrophysical bursts then appears as an important observational diagnostic to complement their detection in space. This would be especially important when space observations suffer from adverse conditions, like saturation, occultation from the Earth, or the passage of the spacecraft through the South Atlantic anomaly.
Spatiotemporal evolution of seismic and aseismic slip on the Longitudinal Valley Fault, Taiwan
Authors: Thomas Marion Y. , Avouac Jean‐Philippe , Champenois Johann , Lee Jian‐Cheng , Kuo Long‐Chen 
Published: May 2014

AbstractThe Longitudinal Valley Fault (LVF) in eastern Taiwan is a high slip rate fault (about 5 cm/yr), which exhibits both seismic and aseismic slip. Deformation of anthropogenic features shows that aseismic creep accounts for a significant fraction of fault slip near the surface, whereas a fraction of the slip is also seismic, since this fault has produced large earthquakes with five Mw>6.8 events in 1951 and 2003. In this study, we analyze a dense set of geodetic and seismological data around the LVF, including campaign mode Global Positioning System(GPS) measurements, time series of daily solutions for continuous GPS stations (cGPS), leveling data, and accelerometric records of the 2003 Chenkung earthquake. To enhance the spatial resolution provided by these data, we complement them with interferometric synthetic aperture radar (InSAR) measurements produced from a series of Advanced Land Observing Satellite images processed using a persistent scatterer technique. The combined data set covers the entire LVF and spans the period from 1992 to 2010. We invert this data to infer the temporal evolution of fault slip at depth using the Principal Component Analysis‐based Inversion Method. This technique allows the joint inversion of diverse data, taking the advantage of the spatial resolution given by the InSAR measurements and the temporal resolution afforded by the cGPS data. We find that (1) seismic slip during the 2003 Chengkung earthquake occurred on a fault patch which had remained partially locked in the interseismic period, (2) the seismic rupture propagated partially into a zone of shallow aseismic interseismic creep but failed to reach the surface, and (3) that aseismic afterslip occurred around the area that ruptured seismically. We find consistency between geodetic and seismological constraints on the partitioning between seismic and aseismic creep. About 80–90% of slip on the southern section of LVF in the 0–26 km, seismogenic depth range, is actually aseismic. We infer that the clay‐rich Lichi Mélange is the key factor promoting aseismic creep at shallow depth.
Decadal Δ17O record of tropospheric CO2: Verification of a stratospheric component in the troposphere
Authors: Thiemens Mark H. , Chakraborty Subrata , Jackson Teresa L. 
Published: May 2014

AbstractFor quantification and prediction of global warming due to anthropogenic carbon dioxide (CO2) emissions, high‐resolution determination of carbon cycle reservoir size and rates of exchange is vital. Isotope ratio measurements of 13C and 18O in CO2 have proven their utility in resolving the carbon cycle. Here we report a long‐term record of triple oxygen isotopic composition of tropospheric CO2. A presence of a steady state stratospheric component (Δ17O = ln[(δ17O + 1) − 0.522 ln(δ18O + 1)] = 0.08 ± 0.04‰) is observed in tropospheric CO2 after modeling via a long‐term spline fit of the record, adding an additional technique for quantification of CO2 fluxes. The δ18O of CO2 (measured as O2 for oxygen triple isotopic composition) from the present study is compared to the measurements of the Scripps Institute of Oceanography CO2 network (measured as CO2 for δ13C and δ18O) and found to be comparable. We note that the triple oxygen isotopic signal (Δ17O) significantly decreased to 0.02 ± 0.02‰ from the steady state value of 0.08 ± 0.04‰ during the 1997–1999 time period. The possible causes for this depletion are evaluated and discussed. An enhanced role of global primary productivity, facilitating water‐CO2 isotope exchange is possible, and future measurements and modeling strategies may develop this further.
Comprehensive ecosystem model‐data synthesis using multiple data sets at two temperate forest free‐air CO2 enrichment experiments: Model performance at ambient CO2 concentration
Authors: Walker Anthony P. , Hanson Paul J. , De Kauwe Martin G. , Medlyn Belinda E. , Zaehle Sönke , Asao Shinichi , Dietze Michael , Hickler Thomas , Huntingford Chris , Iversen Colleen M. , Jain Atul , Lomas Mark , Luo Yiqi , McCarthy Heather , Parton William J. , Prentice I. Colin , Thornton Peter E. , Wang Shusen , Wang Ying‐Ping , Warlind David , Weng Ensheng , Warren Jeffrey M. , Woodward F. Ian , Oren Ram , Norby Richard J. 
Published: May 2014

AbstractFree‐air CO2 enrichment (FACE) experiments provide a remarkable wealth of data which can be used to evaluate and improve terrestrial ecosystem models (TEMs). In the FACE model‐data synthesis project, 11 TEMs were applied to two decadelong FACE experiments in temperate forests of the southeastern U.S.—the evergreen Duke Forest and the deciduous Oak Ridge Forest. In this baseline paper, we demonstrate our approach to model‐data synthesis by evaluating the models' ability to reproduce observed net primary productivity (NPP), transpiration, and leaf area index (LAI) in ambient CO2 treatments. Model outputs were compared against observations using a range of goodness‐of‐fit statistics. Many models simulated annual NPP and transpiration within observed uncertainty. We demonstrate, however, that high goodness‐of‐fit values do not necessarily indicate a successful model, because simulation accuracy may be achieved through compensating biases in component variables. For example, transpiration accuracy was sometimes achieved with compensating biases in leaf area index and transpiration per unit leaf area. Our approach to model‐data synthesis therefore goes beyond goodness‐of‐fit to investigate the success of alternative representations of component processes. Here we demonstrate this approach by comparing competing model hypotheses determining peak LAI. Of three alternative hypotheses—(1) optimization to maximize carbon export, (2) increasing specific leaf area with canopy depth, and (3) the pipe model—the pipe model produced peak LAI closest to the observations. This example illustrates how data sets from intensive field experiments such as FACE can be used to reduce model uncertainty despite compensating biases by evaluating individual model assumptions.
Hyporheic transport and biogeochemical reactions in pool‐riffle systems under varying ambient groundwater flow conditions
Authors: Trauth Nico , Schmidt Christian , Vieweg Michael , Maier Uli , Fleckenstein Jan H. 
Published: May 2014

AbstractAt the interface between stream water, groundwater, and the hyporheic zone (HZ), important biogeochemical processes that play a crucial role in fluvial ecology occur. Solutes that infiltrate into the HZ can react with each other and possibly also with upwelling solutes from the groundwater. In this study, we systematically evaluate how variations of gaining and losing conditions, stream discharge, and pool‐riffle morphology affect aerobic respiration (AR) and denitrification (DN) in the HZ. For this purpose, a computational fluid dynamics model of stream water flow is coupled to a reactive transport model. Scenarios of variations of the solute concentration in the upwelling groundwater were conducted. Our results show that solute influx, residence time, and the size of reactive zones strongly depend on presence, magnitude, and direction of ambient groundwater flow. High magnitudes of ambient groundwater flow lower AR efficiency by up to 4 times and DN by up to 3 orders of magnitude, compared to neutral conditions. The influence of stream discharge and morphology on the efficiency of AR and DN are minor, in comparison to that of ambient groundwater flow. Different scenarios of O2 and NO3 concentrations in the upwelling groundwater reveal that DN efficiency of the HZ is highest under low upwelling magnitudes accompanied with low concentrations of O2 and NO3. Our results demonstrate how ambient groundwater flow influences solute transport, AR, and DN in the HZ. Neglecting groundwater flow in stream‐groundwater interactions would lead to a significant overestimation of the efficiency of biogeochemical reactions in fluvial systems.
Navigating financial and supply reliability tradeoffs in regional drought management portfolios
Authors: Zeff Harrison B. , Kasprzyk Joseph R. , Herman Jonathan D. , Reed Patrick M. , Characklis Gregory W. 
Published: May 2014

AbstractRising development costs and growing concerns over environmental impacts have led many communities to explore more diversified water management strategies. These “portfolio”‐style approaches integrate existing supply infrastructure with other options such as conservation measures or water transfers. Diversified water supply portfolios have been shown to reduce the capacity and costs required to meet demand, while also providing greater adaptability to changing hydrologic conditions. However, this additional flexibility can also cause unexpected reductions in revenue (from conservation) or increased costs (from transfers). The resulting financial instability can act as a substantial disincentive to utilities seeking to implement more innovative water management techniques. This study seeks to design portfolios that employ financial tools (e.g., contingency funds and index insurance) to reduce fluctuations in revenues and costs, allowing these strategies to achieve improved performance without sacrificing financial stability. This analysis is applied to the development of coordinated regional supply portfolios in the “Research Triangle” region of North Carolina, an area comprising four rapidly growing municipalities. The actions of each independent utility become interconnected when shared infrastructure is utilized to enable interutility transfers, requiring the evaluation of regional tradeoffs in up to five performance and financial objectives. Diversified strategies introduce significant tradeoffs between achieving reliability goals and introducing burdensome variability in annual revenues and/or costs. Financial mitigation tools can mitigate the impacts of this variability, allowing for an alternative suite of improved solutions. This analysis provides a general template for utilities seeking to navigate the tradeoffs associated with more flexible, portfolio‐style management approaches.
Characterizing magnetofossils from first‐order reversal curve (FORC) central ridge signatures
Authors: Heslop David , Roberts Andrew P. , Chang Liao 
Published: May 2014

AbstractThe central ridge structure of a first‐order reversal curve (FORC) distribution is indicative of uniaxial noninteracting single domain magnetic particles, which provides the opportunity to identify and characterize biogenic magnetic mineral remains (magnetofossils) in sediments. Recent studies have shown that magnetofossils are widespread in the geological record and that they carry useful environmental information and contribute to paleomagnetic recording, which makes it essential to quantify how these biogenic components contribute to the magnetic properties of sediments. We present results from six sedimentary sequences whose magnetic mineral assemblages contain a significant magnetofossil contribution. Using principal component analysis, we find that the central ridge properties exhibit both intra‐sequnce and inter‐sequence variability that may be ascribed to external environmental factors. While samples from individual sediment sequences tend to cluster together, there is a continuum of inter‐sequence behavior that appears to be related to a variety of magnetofossil properties. We demonstrate the complexity of biogenic magnetic components in sedimentary environments, but also the power and potential of FORC central ridges for understanding magnetic mixtures and unraveling environmental information.
Dayside episodic ion outflow from Martian magnetic cusps and/or magnetosheath boundary motion associated with plasma oscillations
Authors: Duru F. , Gurnett D. A. , Morgan D. D. , Lundin R. , Duru I. H. , Winningham J. D. , Frahm R. A. 
Published: May 2014

AbstractThe radar sounder on the Mars Express Spacecraft is able to make measurements of electron densities in the Martian ionosphere from both local electron plasma oscillations and remote soundings. A study of thousands of orbits shows that in some cases the electron plasma oscillations disappear and reappear abruptly near the upper boundary of the dayside ionosphere. In some cases, the Analyzer of Space Plasmas and Energetic Atoms (ASPERA‐3) data show clear evidence of upwardly accelerated ionospheric ions, on interconnected magnetic field lines. In other cases, ASPERA‐3 data show that when the plasma oscillations disappear, the spacecraft is in the magnetosheath and when they return, the ionospheric plasma reappears. These intermittent appearances of plasma suggest the multiple crossings of the magnetosheath boundary. The motion of the boundary or plasma clouds and ionospheric streamers (a relatively narrow strip of plasma attached to the ionosphere) can cause these multiple crossings.
Dynamic auroral storms on Saturn as observed by the Hubble Space Telescope
Authors: Nichols J. D. , V.Badman S. , Baines K. H. , Brown R. H. , Bunce E. J. , Clarke J. T. , Cowley S. W. H. , Crary F. J. , Dougherty M. K. , Gérard J.‐C. , Grocott A. , Grodent D. , Kurth W. S. , Melin H. , Mitchell D. G. , Pryor W. R. , Stallard T. S. 
Published: May 2014

AbstractWe present observations of significant dynamics within two UV auroral storms observed on Saturn using the Hubble Space Telescope in April/May 2013. Specifically, we discuss bursts of auroral emission observed at the poleward boundary of a solar wind‐induced auroral storm, propagating at ∼330% rigid corotation from near ∼01 h LT toward ∼08 h LT. We suggest that these are indicative of ongoing, bursty reconnection of lobe flux in the magnetotail, providing strong evidence that Saturn's auroral storms are caused by large‐scale flux closure. We also discuss the later evolution of a similar storm and show that the emission maps to the trailing region of an energetic neutral atom enhancement. We thus identify the auroral form with the upward field‐aligned continuity currents flowing into the associated partial ring current.
The atmospheric anomalies associated with the drought over the Yangtze River basin during spring 2011
Authors: Lu Er , Liu Siyuan , Luo Yali , Zhao Wei , Li Hui , Chen Hongxing , Zeng Yingting , Liu Peng , Wang Xiaomin , Higgins R. Wayne , Halpert Mike S. 
Published: May 2014

AbstractThe middle and lower reaches of the Yangtze River basin (MLRY) suffered a once‐in‐a‐50‐year drought during the spring of 2011. The abnormality of the atmospheric circulation in the spring is characterized by the deeper‐than‐normal trough over East Asia and the northwest Pacific while stronger‐than‐normal high‐pressure system over the west, which results in a stronger‐than‐normal meridional circulation. Meanwhile, the western Pacific subtropical high is weaker than normal and retreats to the east, so the spring monsoonal moist air from lower latitudes is relatively weak. The anomalous northerly wind in higher latitudes suppresses the northward motion of the moist air and brings dry air to the MLRY. The northerly wind also suppresses the northward motion of warm air and brings cold air to the MLRY. So finally, the air over the MLRY is drier, but colder than normal, which is different from many other droughts. The coldness of the air plays a negative role to the drought. Results from comparing the Cq and CT, the measures of the changes in moisture and temperature between this spring and the normal spring defined based on the tight precipitation‐relative humidity relation, indicate that the dryness of the air is much stronger than the coldness, and the air over the MLRY thus maintains a lower‐than‐normal relative humidity. The animation of daily Cq and CT shows that dry and cold air moves from the northwest to the MLRY in a manner of low‐frequency oscillation.
Manufacturing: An Introduction to Production Technology, Quality Assurance, and
SCM
Authors: Ueda Naoki 
Published: May 2014

Abstract

This chapter gives a brief overview and description of production technology for electronic control unit (
ECU
) production using an engine
ECU
as a representative example of an
ECU
and also summarizes quality assurance approaches and methods during
ECU
production. Supplier chain management, which is an essential part of production activities, is also outlined in view of significant supply issues that have surfaced in recent years.
Forty‐five year trends in overweight and obesity in an indigenous arctic inuit society in transition and spatiotemporal trends
Authors: Andersen Stig , Rex Karsten Fleischer , Noahsen Paneeraq , Sørensen Hans Christian Florian , Larsen Nicolai Hardenberg , Mulvad Gert , Laurberg Peter 
Published: May 2014

ABSTRACTObjectivesOverweight and obesity associate with increased morbidity and premature death. Westernization of societies heralds rising obesity rates. A steep increase in body mass index (BMI) and overweight in Greenland from 1963 to 1998 led us to follow‐up on height, weight, BMI, and rates of overweight among populations in Greenland and assess time trends between different stages of transition.MethodsBMI was calculated from height and weight measured on Inuit and non‐Inuit aged 50 through 69 years surveyed in 1963, 1998, and 2008 in Ammassalik district in East Greenland and in 1998 and 2008 in the capital Nuuk in West Greenland.ResultsA total of 1,186 were surveyed in 1963 (52 men/63 women), 1998 (309/226), and 2008 (297/239). BMI increased with time (P < 0.001; 1963/1998/2008 23.3/24.3/26.2 kg/m2). In addition, BMI increased with urbanization in Inuit men (P = 0.001; settlements/town/city, in 1998, 23.9/24.9/25.5 kg/m2; in 2008, 25.0/26.0/27.0 kg/m2) while not in Inuit women (P = 0.18). The number of overweight Inuit (BMI >27 kg/m2) increased with time in men (4.0/25.6/33.2% in 1963/1998/2008, P = 0.001) and in women (13.6/30.7/37.3%, P = 0.001). BMI was above 30 kg/m2 in 2.0/10.8/17.5% of all Inuit men in 1963/1998/2008 (P = 0.003) and in 8.3%/23.0/24.5% of all Inuit women (P = 0.02) respectively.ConclusionsOverweight and obesity rates rise with time and with societal transition in Greenland. Settlements and town are catching up with the city where the rate of increase is diminishing, although there were gender differences. Am. J. Hum. Biol. 26:511–517, 2014. © 2014 Wiley Periodicals, Inc.
Revisiting the daily human birth pattern: Time of delivery at casa de maternidad in Madrid (1887–1892)
Authors: Varea Carlos , Fernández‐Cerezo Susana 
Published: May 2014

ABSTRACTObjectivesAmong the ancestral characteristics of the primate group to which Homo sapiens belongs we find a pattern of daytime physical activity, but one notable exception is birthing which usually begins with night‐time labor. In populations with a moderate or high level of medicalized labor, there is evidence that the medical preferences interfere with the underlying biological mechanism for the circadian pattern of human birth.MethodsThis study analyses the hourly patterns of 4,599 single live births in the House of Maternity in Madrid between 1887 and 1892, a period of very limited obstetric intervention and without the influence of artificial lighting. In order to determine the influence of natural light on labor, two periods of maximum and minimum light have been established around the summer and winter solstices of the years in question.ResultsA clear circadian pattern of births emerges, with very early morning and early morning births dominating, and a sharp drop from midday until nightfall. The hourly distribution on both solstices follows this pattern, but with a clear peak shift: in winter, there is a greater concentration of deliveries in the early morning, whereas in the summer, the highest concentration is between 8 and 12 in the morning.ConclusionsThe results confirm that non‐intervened human birth has a clear diurnal cycle, with a higher incidence of deliveries in the early morning or morning. The shift in distribution during the winter and summer solstices seems to confirm the effect of light on the labor process. Am. J. Hum. Biol. 26:707–709, 2014. © 2014 Wiley Periodicals, Inc.
Questions of khoesan continuity: Dental affinities among the indigenous holocene peoples of South Africa
Authors: Irish Joel D. , Black Wendy , Sealy Judith , Ackermann Rebecca Rogers 
Published: May 2014

ABSTRACTThe present report follows up on the findings of previous research, including recent bioarchaeological study of well‐dated Khoesan skeletal remains, that posits long term biological continuity among the indigenous peoples of South Africa after the Pleistocene. The Arizona State University Dental Anthropology System was used to record key crown, root, and intraoral osseous nonmetric traits in six early‐through‐late Holocene samples from the Cape coasts. Based on these data, phenetic affinities and an identification of traits most important in driving intersample variation were determined using principal components analysis and the mean measure of divergence distance statistic. To expand biological affinity comparisons into more recent times, and thus preliminarily assess the dental impact of disproportionate non‐Khoesan gene flow into local peoples, dental data from historic Khoekhoe and San were also included. Results from the prehistoric comparisons are supportive of population continuity, though a sample from Matjes River Rockshelter exhibits slight phenetic distance from other early samples. This and some insignificant regional divergence among these coastal samples may be related to environmental and cultural factors that drove low‐level reproductive isolation. Finally, a close affinity of historic San to all samples, and a significant difference of Khoekhoe from most early samples is reflective of documented population history following immigration of Bantu‐speakers and, later, Europeans into South Africa. Am J Phys Anthropol 155:33–44, 2014. © 2014 Wiley Periodicals, Inc.