bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abrupt magma chamber contraction and microseismicity at Campi Flegrei, Italy: Cause and effect determined from strainmeters and tiltmeters
Authors: Amoruso Antonella , Crescentini Luca , Scarpa Roberto , Bilham Roger , Linde Alan T. , Sacks I. Selwyn 
Published: July 2015

AbstractIn March 2010 two borehole strainmeters and three Michelson tiltmeters within the Campi Flegrei volcanic system, Italy, registered an abrupt deformation signal that was followed 20 min later by seismic slip on a pair of onshore normal faults. We demonstrate that the observed strain changes were caused by a small but rapid volume decrease in a previously identified offshore ellipsoidal magma source or part of it. Although the total deflation was below the detectability of interferometric synthetic aperture radar and GPS, deflation observed rates were briefly 2 orders of magnitude more rapid than decadal inflation rates. We conclude that this high dilatational contraction rate was responsible for triggering seismicity and that this process may be responsible for the normal faulting often observed in the Campi Flegrei region. Our study quantifies the crucial role played by a transient, minor reduction in dilatational stress, in triggering slip on a fault near critical failure. Our subsurface measurements of strain and tilt registered anomalous deformation three sigma above background noise levels 17 min before the onset of microseismicity suggesting strain measurements have potential utility as an early warning system for the city of Naples.
Measuring fluid flow and heat output in seafloor hydrothermal environments
Authors: Germanovich Leonid N. , Hurt Robert S. , Smith Joshua E. , Genc Gence , Lowell Robert P. 
Published: July 2015

AbstractWe review techniques for measuring fluid flow and advective heat output from seafloor hydrothermal systems and describe new anemometer and turbine flowmeter devices we have designed, built, calibrated, and tested. These devices allow measuring fluid velocity at high‐ and low‐temperature focused and diffuse discharge sites at oceanic spreading centers. The devices perform at ocean floor depths and black smoker temperatures and can be used to measure flow rates ranging over 2 orders of magnitude. Flow velocity is determined from the rotation rate of the rotor blades or paddle assembly. These devices have an open bearing design that eliminates clogging by particles or chemical precipitates as the fluid passes by the rotors. The devices are compact and lightweight enough for deployment from either an occupied or remotely operated submersible. The measured flow rates can be used in conjunction with vent temperature or geochemical measurements to obtain heat outputs or geochemical fluxes from both vent chimneys and diffuse flow regions. The devices have been tested on 30 Alvin dives on the Juan de Fuca Ridge and 3 Jason dives on the East Pacific Rise (EPR). We measured an anomalously low entrainment coefficient (0.064) and report 104 new measurements over a wide range of discharge temperatures (5°–363°C), velocities (2–199 cm/s), and depths (1517–2511 m). These include the first advective heat output measurements at the High Rise vent field and the first direct fluid flow measurement at Middle Valley. Our data suggest that black smoker heat output at the Main Endeavour vent field may have declined since 1994 and that after the 2005–2006 eruption, the high‐temperature advective flow at the EPR 9°50′N field may have become more channelized, predominately discharging through the Bio 9 structure. We also report 16 measurements on 10 Alvin dives and 2 Jason dives with flow meters that predate devices described in this work and were used in the process of their development. This includes the first advective measurements in the Lau Basin and at the EPR 9°39.5′N. We discuss potential error sources and how they may affect the accuracy of measurements by our devices and other devices. In particular, we use the turbulent plume theory to evaluate the effect of entrainment of ambient seawater.
On the dynamics of the Zanzibar Channel
Authors: Zavala‐Garay J. , Theiss J. , Moulton M. , Walsh C. , van Woesik R. , Mayorga‐Adame C. G. , García‐Reyes M. , Mukaka D. S. , Whilden K. , Shaghude Y. W. 
Published: July 2015

AbstractThe Zanzibar Channel lies between the mainland of Tanzania and Zanzibar Island in the tropical western Indian Ocean, is about 100 km long, 40 km wide, and 40 m deep, and is essential to local socioeconomic activities. This paper presents a model of the seasonal and tidal dynamics of the Zanzibar Channel based on the Regional Ocean Modeling System (ROMS) and a comparison of the model and observations. The seasonal dynamics of the channel is forced by remote processes and the local wind. Remote forcing creates the East African Coastal Current, a portion of which flows through the channel northward with a seasonally varying magnitude. The local wind enhances this seasonality in the surface Ekman layer, resulting in a stronger northward flow during the southwest monsoon season and a weak northward or occasionally southward flow during the northeast monsoon season. The tidal flows converge and diverge in the center of the channel and reduce the transport in the channel. The remotely forced, wind‐forced, and tidal dynamics contain 5%, 3%, and 92% of the total kinetic energy, respectively. Despite their low kinetic energy, the remotely forced and wind‐forced flows are most relevant in advecting channel water to the open ocean, which occurs in 19 days at the peak of the southwest monsoon season. The channel is well mixed, except during brief periods in the two rainy seasons, and temporarily cools between December and February. The dispersion of passive tracers is presented as an example of potential model applications.
Comparison of viscoelastic‐type models for ocean wave attenuation in ice‐covered seas
Authors: Mosig Johannes E. M. , Montiel Fabien , Squire Vernon A. 
Published: July 2015

AbstractContinuum‐based models that describe the propagation of ocean waves in ice‐infested seas are considered, where the surface ocean layer (including ice floes, brash ice, etc.) is modeled by a homogeneous viscoelastic material which causes waves to attenuate as they travel through the medium. Three ice layer models are compared, namely a viscoelastic fluid layer model currently being trialed in the spectral wave model WAVEWATCH III® and two simpler viscoelastic thin beam models. All three models are two dimensional. A comparative analysis shows that one of the beam models provides similar predictions for wave attenuation and wavelength to the viscoelastic fluid model. The three models are calibrated using wave attenuation data recently collected in the Antarctic marginal ice zone as an example. Although agreement with the data is obtained with all three models, several important issues related to the viscoelastic fluid model are identified that raise questions about its suitability to characterize wave attenuation in ice‐covered seas. Viscoelastic beam models appear to provide a more robust parameterization of the phenomenon being modeled, but still remain questionable as a valid characterization of wave‐ice interactions generally.
Debris entrainment and landform genesis during tidewater glacier surges
Authors: Lovell Harold , Fleming Edward J. , Benn Douglas I. , Hubbard Bryn , Lukas Sven , Rea Brice R. , Noormets Riko , Flink Anne E. 
Published: July 2015

AbstractThe englacial entrainment of basal debris during surges presents an opportunity to investigate processes acting at the glacier bed. The subsequent melt‐out of debris‐rich englacial structures during the quiescent phase produces geometrical ridge networks on glacier forelands that are diagnostic of surge activity. We investigate the link between debris entrainment and proglacial geomorphology by analyzing basal ice, englacial structures, and ridge networks exposed at the margins of Tunabreen, a tidewater surge‐type glacier in Svalbard. The basal ice facies display clear evidence for brittle and ductile tectonic deformation, resulting in overall thickening of the basal ice sequence. The formation of debris‐poor dispersed facies ice is the result of strain‐induced metamorphism of meteoric ice near the bed. Debris‐rich englacial structures display a variety of characteristics and morphologies and are interpreted to represent the incorporation and elevation of subglacial till via the squeezing of till into basal crevasses and hydrofracture exploitation of thrust faults, reoriented crevasse squeezes, and preexisting fractures. These structures are observed to melt‐out and form embryonic geometrical ridge networks at the base of a terrestrially grounded ice cliff. Ridge networks are also located at the terrestrial margins of Tunabreen, neighboring Von Postbreen, and in a submarine position within Tempelfjorden. Analysis of network characteristics allows these ridges to be linked to different formational mechanisms of their parent debris‐rich englacial structures. This in turn provides an insight into variations in the dominant tectonic stress regimes acting across the glacier during surges.
Predicting permeability from the characteristic relaxation time and intrinsic formation factor of complex conductivity spectra
Authors: Revil A. , Binley A. , Mejus L. , Kessouri P. 
Published: July 2015

AbstractLow‐frequency quadrature conductivity spectra of siliclastic materials exhibit typically a characteristic relaxation time, which either corresponds to the peak frequency of the phase or the quadrature conductivity or a typical corner frequency, at which the quadrature conductivity starts to decrease rapidly toward lower frequencies. This characteristic relaxation time can be combined with the (intrinsic) formation factor and a diffusion coefficient to predict the permeability to flow of porous materials at saturation. The intrinsic formation factor can either be determined at several salinities using an electrical conductivity model or at a single salinity using a relationship between the surface and quadrature conductivities. The diffusion coefficient entering into the relationship between the permeability, the characteristic relaxation time, and the formation factor takes only two distinct values for isothermal conditions. For pure silica, the diffusion coefficient of cations, like sodium or potassium, in the Stern layer is equal to the diffusion coefficient of these ions in the bulk pore water, indicating weak sorption of these couterions. For clayey materials and clean sands and sandstones whose surface have been exposed to alumina (possibly iron), the diffusion coefficient of the cations in the Stern layer appears to be 350 times smaller than the diffusion coefficient of the same cations in the pore water. These values are consistent with the values of the ionic mobilities used to determine the amplitude of the low and high‐frequency quadrature conductivities and surface conductivity. The database used to test the model comprises a total of 202 samples. Our analysis reveals that permeability prediction with the proposed model is usually within an order of magnitude from the measured value above 0.1 mD. We also discuss the relationship between the different time constants that have been considered in previous works as characteristic relaxation time, including the mean relaxation time obtained from a Debye decomposition of the spectra and the Cole‐Cole time constant.
Working Memory Capacity Offers Resistance to Mind‐Wandering and External Distraction in a Context‐Specific Manner
Authors: Robison Matthew K. , Unsworth Nash 
Published: July 2015

SummaryThe present study examined the impact of mind‐wandering and distraction in silent and noisy studying environments and how individual differences in working memory capacity offered resistance to these two distinct forms of attention failure. Two groups of participants read a text in different environments and answered reading comprehension questions. While reading, thought probes asked participants to indicate the current focus of their attention. Results showed that the relationship between working memory capacity and reading comprehension was partially driven by resistance to mind‐wandering in the silent condition and by resistance to external distraction in the noise condition. The findings support the distinction between mind‐wandering and external distraction, two separate yet related types of attention failure that impact task performance. Further, executive abilities seem to offer resistance to these two types of attention failure differentially depending on the context. Copyright © 2015 John Wiley & Sons, Ltd.
Information Integration Theory, Juror Bias, and Sentence Recommendations Captured Over Time in a Capital Trial
Authors: Estrada‐Reynolds Victoria C. , Gray Jennifer M. , Nuñez Narina 
Published: July 2015

SummaryInitial juror verdicts have been shown to predict final verdicts, leading researchers to conclude that jurors seek confirmatory information during trial (confirmation bias) or distort information to fit pre‐existing biases (pre‐decisional distortion). However, Information Integration Theory suggests that individuals are not distorting/ignoring this information, and instead, information influences judgments in the direction of the message. The current study sought to test these competing theories in a juror setting. Mock jurors were presented with the sentencing phase of a capital trial and were asked to give sentence recommendations at eight different time points. Additionally, they were grouped by their pretrial bias as being pro‐defense, neutral, or pro‐prosecution. Results showed support for Information Integration Theory; although jurors' pretrial bias predicted final sentence, sentence recommendations were affected in the direction of the testimony presented throughout the trial (e.g., pro‐defense testimony lowered death penalty decisions across all groups). Implications and future directions are discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Tracking analysis of augmented complex least mean square algorithm
Authors: Khalili Azam , Rastegarnia Amir 
Published: July 2015

SummaryThe augmented complex least mean‐square (ACLMS) algorithm is a suitable algorithm for the processing of both second‐order circular (proper) and noncircular (improper) signals. In this paper, we provide tracking analysis of the ACLMS algorithm in the non‐stationary environments. Using the established energy conservation argument, we derive a variance relation that contains moments that represent the effects of non‐stationary environment. We evaluate these moments and derive closed‐form expressions for the excess mean‐square error (EMSE) and mean‐square error (MSE). The derived expressions, supported by simulations, reveal that unlike the stationary case, the steady‐state EMSE, and MSE curves are not monotonically increasing functions of the step‐size parameter. We also use this observation to optimize the step‐size learning parameter. Simulation results illustrate the theoretical findings and match well with theory. Copyright © 2015 John Wiley & Sons, Ltd.
Synthesis of Quinolines by Visible‐Light Induced Radical Reaction of Vinyl Azides and α‐Carbonyl Benzyl Bromides
Authors: Wang Qile , Huang Jun , Zhou Lei 
Published: July 2015

AbstractA visible‐light induced radical reaction of vinyl azides and α‐carbonyl benzyl bromides was developed, which provides an efficient route to polysubstituted quinolines via a CC and CN bond formation sequence.magnified image
A Virtual geometric morphometric approach to the quantification of long bone bilateral asymmetry and cross‐sectional shape
Authors: Wilson Laura A.B. , Humphrey Louise T. 
Published: July 2015

ABSTRACTObjectiveThe widespread use of three‐dimensional digitization means that models of whole bone geometry are routinely captured for many applications in virtual anthropology. In this article, we test whether a geometric morphometric (GMM) approach can be used to accurately quantify directional bilateral asymmetry in cross‐sectional shape using virtual bone models.MethodsWe introduce a method to (1) orient virtual long bone models and extract cross sections and (2) collect GMM landmarks to analyze cross‐sectional shape. Landmark data, captured using polar radii, were analyzed for an example study set of paired humeri from Andaman Islanders sampled at 35%, 50%, and 65% locations.ResultsThe GMM method can (1) detect significant differences in left and right cross‐sectional shape and (2) allow the directionality of shape change (distribution of bone from centroid) to be evaluated in the context of whole outline shape and in relation to the axis of maximum bending rigidity. The protocol may be used with models created from laser (surface) scan or computed tomography (CT) scan data, and applied to cross‐sectional images that were collected using periosteal molding techniques.ConclusionsThe results demonstrate directional bilateral asymmetry in shape, but do not recover the same signal for size measurements. Our method offers a pathway to quantify both the pattern of variation in shape and the relationship between size and shape variation, opening new questions about how those patterns manifest over ontogeny, change temporally or differ in relation to the nature and intensity of the activity, and bone loading conditions. Am J Phys Anthropol 158:541–556, 2015. © 2015 Wiley Periodicals, Inc.
Ancient marine hunter‐gatherers from Patagonia and Tierra Del Fuego: Diversity and differentiation using uniparentally inherited genetic markers
Authors: de la Fuente Constanza , Galimany Jacqueline , Kemp Brian M. , Judd Kathleen , Reyes Omar , Moraga Mauricio 
Published: July 2015

ABSTRACTObjectivesThe human population history from Patagonia and Tierra del Fuego has been of great interest in the context of the American peopling. Different sources of evidence have contributed to the characterization of the local populations, but some main questions about their history remain unsolved. Among the native populations, two marine hunter‐gatherers groups inhabited the Patagonian channels below the 478S: Kawéskar and Yámana. Regardless of their geographical proximity and cultural resemblance, their languages were mutually unintelligible. In this study we aim to evaluate the genetic diversity of uniparental genetic markers in both groups and to test if there is a high genetic differentiation between them, mirroring their linguistic differences.Material and MethodsAncient DNA was extracted from 37 samples from both populations. We compared their genetic variability of their mitochondrial lineages and Y‐STR as well as with other modern native populations from the area and further north.Results and DiscussionWe observed an important differentiation in their maternal lineages: while Kawéskar shows a high frequency of D (80%), Yámana shows a high frequency of C (90%). The analysis of paternal lineages reveals the presence of only Q1a2a1a1 and little variation was found between individuals. Both groups show very low levels of genetic diversity compared with modern populations. We also notice shared and unique mitochondrial DNA variants between modern and ancient samples of Kawéskar and Yámana. Am J Phys Anthropol 158:719–729, 2015. © 2015 Wiley Periodicals, Inc.
The skeletal manifestation of malaria: An epidemiological approach using documented skeletal collections
Authors: Smith‐Guzmán Nicole E. 
Published: July 2015

ABSTRACTObjectivesRecent studies in paleopathology have shown promise in associating some skeletal lesions with malarial infection. However, malaria's skeletal manifestation has never been confirmed using a large clinical reference sample from an endemic area for malaria with known individual causes of death.Materials and MethodsTo pinpoint evidence of malaria infection on ancient skeletal remains, this study uses an epidemiological approach to compare skeletal lesions in a modern reference sample of 98 individuals from Uganda, where malaria is holoendemic, to a similar modern sample of 106 individuals from a malaria‐free area.ResultsFive porous skeletal lesions are identified that appear more frequently in the endemic area population, especially in anemic individuals. These appear on the cranium, vertebral column, and humeral and femoral necks. Periostitis also associates strongly with individuals in the endemic population; however, linear enamel hypoplasias show an inverse association. The identified lesions are tested for their association with each other, and then tested individually for their diagnostic power through measures of sensitivity and specificity. A diagnostic outcome algorithm is formed from the remaining skeletal lesions and their inter‐lesion associations.DiscussionSeveral etiological explanations for the characteristic malarial skeletal lesions are explored, including severe malarial anemia, an imbalance in bone remodeling, and extramedullary erythropoiesis. The importance of careful differential diagnoses between other infectious and noninfectious causes of these lesions is discussed, including the potential for coinfection of malaria with other infectious diseases. The findings of this study are pivotal in establishing diagnostic criteria by which we can identify the prevalence and impact of malaria on past populations. Am J Phys Anthropol 158:624–635, 2015. © 2015 Wiley Periodicals, Inc.
The effect of nasal irrigation formulation on the antimicrobial activity of nasal secretions
Authors: Woods Charmaine M. , Tan Sophia , Ullah Shahid , Frauenfelder Claire , Ooi Eng H. , Carney A. Simon 
Published: July 2015

BackgroundSaline‐based irrigation solutions are evidence‐based rhinological treatments; however, the formulation of these solutions could theoretically alter the function of innate antimicrobial peptides. The aim of this study was to determine if the antimicrobial activity of normal human nasal secretions in vivo is altered by commercially available large volume irrigation solutions.MethodsMinimally manipulated sinonasal secretions were collected from patients with chronic rhinosinusitis (CRS; n = 10) and normal healthy volunteers (n = 20). In a subset of control patients (n = 10) secretions were collected prior to, and at 1 hour, 6 hours, and 24 hours after nasal irrigation with 4 commercial irrigation solutions. Lysozyme and lactoferrin levels were analyzed and the antimicrobial activity of secretions determined using a radial diffusion assay.ResultsThe antimicrobial activity of nasal secretions was reduced in CRS patients compared to healthy volunteers (p < 0.01), but there was no significant difference in antimicrobial peptide concentrations. Isotonic nasal irrigation reduced lysozyme and lactoferrin levels, which returned to baseline levels by 6 hours; in addition to a sustained decrease in antimicrobial activity before returning to baseline at 24 hours. Low‐salt solution stimulated peptide secretion by approximately 40% at 6 hours and 24 hours, but produced a transient decrease in antimicrobial activity, returning to baseline levels by 6 hours. Hypertonic solution initially decreased lysozyme and lactoferrin levels but maintained baseline levels of antimicrobial activity and increased peptide secretion by approximately 30% at 24 hours.ConclusionThe formulation of nasal irrigation solutions significantly affects the measured levels and functionality of sinonasal antimicrobial peptides.