bluuebunny/crossref_metadata_2025_split huggingface dataset:
Large‐amplitude GPS TEC variations associated with Pc5–6 magnetic field variations observed on the ground and at geosynchronous orbit
Authors: Watson Chris , Jayachandran P. T. , Singer Howard J. , Redmon Robert J. , Danskin Donald 
Published: August 2015

AbstractLarge‐amplitude variations in GPS total electron content (TEC) at Pc5–6 (<6.67 mHz) frequencies have been observed, using a high data rate Global Positioning System (GPS) receiver of the Canadian High Arctic Ionospheric Network. TEC variations with peak‐to‐peak amplitudes of 2–7 TEC units (1 TECU = 1016 el m−2) were observed over a 2.5 h period in the postnoon sector on 9 September 2011, during a period of high auroral activity within a moderate geomagnetic storm. TEC observations were from the Sanikiluaq, Nunavut (56.54°N, 280.77°E) GPS receiver located in the auroral region. Over this same time period, compressional Pc5–6 magnetic field variations were observed by the geosynchronous GOES 13 magnetometer and the ground‐based Sanikiluaq magnetometer. GOES 13 has a northern magnetic footprint in close proximity to Sanikiluaq. Cross‐correlation analysis indicates that magnetic field and TEC variations were possibly linked. No natural hazards or nuclear explosions capable of exciting TEC perturbations were reported on this day. Using a triangulation technique involving TEC measurements of multiple GPS satellites, the propagation velocity of TEC variations in the ionosphere was also calculated. This calculation revealed two distinct events: lower frequency (~0.9 mHz) TEC variations that propagated westward, consistent with the westward propagation of compressional Pc5 waves observed by GOES 13 and 15 satellites, and higher‐frequency (~3.3 mHz) TEC variations that propagated southward. This is the first report of variations in ionospheric TEC linked to satellite observations of Pc5–6 ULF waves.
Gravimetric and magnetic anomalies produced by dissolution‐crystallization at the core‐mantle boundary
Authors: Mandea Mioara , Narteau Clément , Panet Isabelle , Le Mouël Jean‐Louis 
Published: August 2015

AbstractUsing the unique data sets provided by satellite observations, correlated temporal variations in gravity and magnetic fields over a large area extending from the Atlantic to the Indian Ocean have been recently reported. On a timescale of few years to a decade, both field variations may be linked to changes at the top of the core. Here we propose that in addition to the topography generated by the convection in the mantle, the core‐mantle boundary (CMB) may be in a dynamic equilibrium state, mainly controlled by a dissolution‐crystallization process of the mantle silicate rocks in the liquid alloy of the core. Due to the resulting continuous changes in CMB topography, anomalies of hundreds of nGal and tens of nT yr−2might be produced by the corresponding mass redistribution and the secondary flow generated by the associated pressure field. Numerical modeling and both gravimetric and magnetic anomaly magnitudes suggest a rate of centimeters per year and a large range of length scales for the changes in the topography at the CMB.
On the shaping factors of the secondary microseismic wavefield
Authors: Gualtieri L. , Stutzmann E. , Capdeville Y. , Farra V. , Mangeney A. , Morelli A. 
Published: August 2015

AbstractSeismic noise in the period band 3–10 s is known as secondary microseism, and it is generated at the ocean surface by the interaction of ocean gravity waves coming from nearly opposite directions. In this paper, we investigate the seismic content of the wavefield generated by a source at the ocean surface and three of the major wavefield shaping factors using the 2‐D spectral element method: the ocean‐continent boundary, the source site effect, and the thickness of seafloor sediments. The seismic wavefield recorded on the vertical component seismograms below the seafloor is mainly composed of the fundamental mode and the first overtone of Rayleigh waves. A mode conversion from the first overtone to the fundamental mode of Rayleigh waves occurs at the ocean‐continent boundary. The presence of a continental shelf at the ocean‐continent boundary produces a negligible effect on land‐recorded seismograms, whereas the source site effect, i.e., the source location with respect to the local ocean depth and sediment thickness, plays the major role. A source in shallow water mostly enhances the fundamental mode of Rayleigh waves, whereas a source in deep water mainly enhances the first overtone of Rayleigh waves. Land‐recorded long‐period signals (T > 6 s) are mostly due to deep water sources, whereas land‐recorded short‐period signals (T < 6 s) are due to sources in relatively shallow water, located close to the shelf break. Seafloor sediments around the source region trap seismic waves reducing the amplitude of land‐recorded signals, especially at long periods (T > 6 s).
Could the Madagascar bloom be fertilized by Madagascan iron?
Authors: Srokosz M. A. , Robinson J. , McGrain H. , Popova E. E. , Yool A. 
Published: August 2015

AbstractIn the oligotrophic waters to the east of Madagascar, a large phytoplankton bloom is found to occur in late austral summer. This bloom is composed of nitrogen fixers and can cover up to ∼1% of the world's ocean surface area. Satellite observations show that its spatial structure is closely tied to the underlying mesoscale eddy field in the region. The causes of the bloom and its temporal behavior (timing of its initiation and termination) and spatial variability are poorly understood, in part due to a lack of in situ observations. Here an eddy resolving 1/12° resolution ocean general circulation model and Lagrangian particle tracking are used to examine the hypothesis that iron from sediments around Madagascar could be advected east by the mesoscale eddy field to fertilize the bloom, and that variability in advection could explain the significant interannual variability in the spatial extent of the bloom. The model results suggest that this is indeed possible and furthermore imply that the bloom could be triggered by warming of the mixed layer, leading to optimal conditions for nitrogen fixers to grow, while its termination could be due to iron exhaustion. It is found that advection of Madagascan iron could resupply the bloom region with this micronutrient in the period between the termination of one bloom and the initiation of the next in the following year.
Solar influences on spatial patterns of Eurasian winter temperature and atmospheric general circulation anomalies
Authors: Chen Haishan , Ma Hedi , Li Xing , Sun Shanlei 
Published: August 2015

AbstractSolar influences on spatial patterns of Eurasian winter climate and possible mechanisms are investigated based on a multiple linear regression method and multisource observational and reanalysis data. Robust and significant solar signals are detected in Eurasian surface air temperature (SAT), and strong solar activity evidently warms most area of the continent. The spatial pattern of sea level pressure (SLP) responses to solar activity is similar but not identical to that of the North Atlantic Oscillation (NAO). Compared to the NAO, geographic distribution of solar‐induced SLP anomalies shifts eastward, with significantly enhanced influences over northern Eurasia. Relatively weaker solar signals were also found in mid‐to‐upper troposphere. The spatial pattern of 500 hPa geopotential anomalies resembles a negative Scandinavia teleconnection pattern, and the 200 hPa subtropical jet is weakened, while zonal wind at high latitudes is enhanced due to strong solar activity. The anomalous zonal circulations can be attributed to the “top‐down” mechanism. During high solar activity winters, an enhanced stratospheric zonal wind anomaly propagates downward, causing zonal wind anomalies in the troposphere. However, the “bottom‐up” mechanisms may provide more reasonable explanations of the distinct solar influences on Eurasian climate. Solar‐induced strong warm advection in lower atmosphere tends to increase SAT but decrease SLP, resulting in enhanced solar influences over northern Eurasia. Meanwhile, change in the land‐ocean thermal contrast (LOTC) could also amplify the circulation anomaly. Inhomogeneous surface heating caused by anomalous solar activity modifies LOTC, which probably enhances the solar‐induced circulation patterns. Such a positive feedback may potentially strengthen the solar influences.
The ups and downs of North America: Evaluating the role of mantle dynamic topography since the Mesozoic
Authors: Liu Lijun 
Published: August 2015

AbstractThe driving force for transient vertical motions of Earth's surface remains an outstanding question. A main difficulty lies in the uncertain role of the underlying mantle, especially during the geological past. Here I review previous studies on both observational constraints and physical mechanisms of North American topographic evolution since the Mesozoic. I first summarize the North American vertical motion history using proxies from structural geology, geochronology, sedimentary stratigraphy, and geomorphology, based on which I then discuss the published physical models. Overall, there is a progressive consensus on the contribution of mantle dynamic topography due to buoyancy structures associated with the past subduction. At the continental scale, a largely west‐to‐east migrating deformation pattern suggests an eastward translation of mantle dynamic effects, consistent with models involving an eastward subduction and sinking of former Farallon slabs since the Cretaceous. Among the existing models, the inverse model based on an adjoint algorithm and time‐dependent data constraints provides the most extensive explanations for the temporal changes of North American topography since the Mesozoic. At regional scales, debates still exist on the predicted surface subsidence and uplift within both the western and eastern United States, where discrepancies are likely due to differences in model setup (e.g., mantle dynamic properties and boundary conditions) and the amount of time‐dependent observational constraints. Toward the development of the next‐generation predictive geodynamic models, new research directions may include (1) development of enhanced data assimilation capabilities, (2) exploration of multiscale and multiphysics processes, and (3) cross‐disciplinary code coupling.
The Compensatory Role of Implementation Intentions for Young Adults with Low Working Memory Capacity
Authors: Meeks J. Thadeus , Pitães Margarida , Brewer Gene A. 
Published: August 2015

SummaryMany factors improve prospective memory performance both inside and outside of the laboratory, including the detailed planning of the situational cue and intended action (i.e., implementation intentions). In the current study, we obtained measures of working memory capacity and laboratory event‐based prospective memory performance in college‐aged adults. Half of our participants formed an implementation intention in the prospective memory task. Because of evidence that implementation intentions increase the encoding/retrieval efficiency of the prospective memory, it was predicted that forming an implementation intention would serve as a compensatory strategy for those with low working memory ability. Our results supported this hypothesis in that working memory capacity no longer correlated with prospective memory performance when participants employed an implementation intention encoding strategy. These findings suggest that implementation intentions may be an effective way for individuals with low working memory capacity to improve their performance in an attentionally demanding prospective memory task. Copyright © 2015 John Wiley & Sons, Ltd.
Developmental energetics, sibling death, and parental instability as predictors of maturational tempo and life history scheduling in males from Cebu, Philippines
Authors: Gettler Lee T. , McDade Thomas W. , Bragg Jared M. , Feranil Alan B. , Kuzawa Christopher W. 
Published: August 2015

ABSTRACTObjectivesCross‐species comparisons show that high extrinsic mortality favors the evolution of “faster” life histories. There is interest in applying this principle to human life history plasticity, based on the idea that psychosocial stressors that correlate with extrinsic mortality accelerate reproductive pace. Most prior studies have been conducted in settings in which psychosocial stressors co‐occur with the maturation‐accelerating influence of nutritional abundance.Materials and MethodsWe evaluate cues of local mortality (sibling death) or low parental investment (paternal instability; maternal absence) and energetic measures during development as predictors of life history scheduling among males (n = 754) in a Philippine population with marginal developmental nutritional.ResultsMales who had more favorable nutritional status during childhood, as reflected in linear growth, skinfold thickness, and caloric intake, were more maturationally advanced in adolescence (all P < 0.05). Taller stature and higher caloric intake during childhood also predicted earlier ages at first sex (both P < 0.01), which persisted after controlling for the effect of nutrition on pubertal maturation. While psychosocial stressors did not predict accelerated maturation, males who as children grew up with an unstable paternal presence had sex earlier (P < 0.05) and tended to become fathers sooner than those with a stable fatherly presence. Those who had a sibling die became fathers sooner than those who did not (P < 0.05).DiscussionOur findings point to important energetic constraints on the onset of reproductive maturity, while psychosocial stressors accelerate entry to parenthood, which may be comparatively more socially, rather than biologically, constrained. Am J Phys Anthropol 158:175–184, 2015. © 2015 Wiley Periodicals, Inc.
Clavicular curvature and locomotion in anthropoid primates: A 3D geometric morphometric analysis
Authors: Squyres Nicole , DeLeon Valerie Burke 
Published: August 2015

ABSTRACTObjectives:As a component of the primate shoulder, the clavicle is expected to reflect locomotor adaptations. Whereas previous work has generally focused on clavicular length and torsion, the shape of clavicular curvature may better distinguish taxa and provide additional information about upper limb use in locomotion. This study uses three‐dimensional geometric morphometrics to analyze shape differences in the curvatures of the clavicle in different locomotor groups of anthropoid primates.Methods:Sliding semi‐landmarks were placed on clavicles of 10 Anthropoid primate species (total n = 85) that display a range of locomotor behaviors. Landmarks (k = 39) were chosen to capture the overall curvature of the clavicle in three dimensions.Results:The degree of ventral curvature in the clavicle represents a gradient from most‐curved in suspensory genera (e.g., Ateles, Hylobates, and Pongo) to least‐curved in genera that are rarely suspensory (e.g., Papio and Gorilla). This curvature may allow an increased range of craniodorsal movement without the clavicle impinging on the thoracic outlet. An inferior curvature of the medial clavicle is found in hominoids and brachiators. This curvature could help stabilize the shoulder and prevent superior dislocation of the clavicle in suspension. Finally, a superior curvature in the lateral part of the clavicle, most pronounced in quadrupedal monkeys, may be related to the relative position of the scapula and sternum.Conclusions:Patterns of clavicular curvature in anthropoid primates reflect locomotor behavior and successfully distinguished among taxonomic and locomotor groups. In the future, this method could be used to assess locomotor behavior in fossil primates. Am J Phys Anthropol 158:257–268, 2015. © 2015 Wiley Periodicals, Inc.
Evaluating the efficiency of different recording protocols for entheseal changes in regards to expressing activity patterns using archival data and cross‐sectional geometric properties
Authors: Michopoulou Efrossyni , Nikita Efthymia , Valakos Efstratios D. 
Published: August 2015

ABSTRACTObjectivesIn the past decade there have been extensive discussions on the potential utility of entheseal changes (EC) as activity markers. Nevertheless, no study to date has compared different EC recording protocols with respect to their correlation to activity patterns.Materials and MethodsThis article records changes on fibrocartilaginous entheses of the upper limbs of 90 male skeletons from the documented Athens Collection using the Hawkey and Merbs (Int J Osteoarchaeol 5 (1995) 324‐338), Mariotti et al. (Collegium Antropol 28 (2004) 145‐159), and Villotte et al. (Am J Phys Anthropol 142 (2010) 224‐234) recording schemes in order to determine which one exhibits the highest correlation with activity. Activity is assessed by means of the recorded profession of each individual, as well as employing cross‐sectional geometric properties. Generalized Linear Models are used to explore the impact of age, body mass, and activity on EC expression.ResultsOur results agree with previous studies that age is the primary factor determining EC, whereas body mass is the second most influential factor. In contrast, activity in the form of profession or cross‐sectional geometry rarely showed a significant correlation to EC expression and no clear pattern could be discerned irrespective of the recording technique. However, bilateral differences in the impact of age and body mass in EC expression were traced and may relate to activity patterns.ConclusionsThe differences found in the bilateral impact of age and body mass highlight the fact that the activity patterns of the individuals under examination must play an underlying role to EC expression, though current recording schemes for EC do not capture this, rendering further work in the direction of developing more elaborate recording standards imperative. Am J Phys Anthropol 158:557–568, 2015. © 2015 Wiley Periodicals, Inc.
Is honey a fallback food for wild chimpanzees or just a sweet treat?
Authors: McLennan Matthew R. 
Published: August 2015

ABSTRACTObjectivesHoney is a highly nutritious resource for any primate able to exploit it. Wild chimpanzees exploit nests of honey‐making bees (Apini and Meliponini) for honey and brood, typically using tools to overcome the bees’ defences. The universality of honey‐gathering among modern human foragers in tropical climates and chimpanzees suggests energy‐rich honey, acquired with tools, was likely a regular food for ancestral hominins. However, few studies have assessed its role in seasonal foraging strategies of chimpanzees. This study asks whether honey serves as a high‐quality fallback food for chimpanzees at Bulindi, Uganda.Materials and MethodsHoney consumption was investigated via fecal analysis over 22 months during two studies (Study 1: 2007–2008; Study 2: 2012–2014). Additionally, flower and fruit phenology was measured during Study 1; peak flowering intensity was expected to facilitate increased honey and/or brood production by bees.ResultsChimpanzees consumed honey (and/or brood) at low frequencies year‐round, but bees/beeswax appeared in feces at higher frequencies with decreasing fruit availability (Study 1). Honey consumption was unrelated to flowering and chimpanzees did not consume honey more frequently during the “honey season” when local people harvest beehives. Moreover, consumption was inversely related to fruit intake (both study periods).DiscussionAlthough honey fits the functional definition of a filler fallback food at Bulindi, the chimpanzees unlikely depend on honey to replace nutrients provided by fruit. Overall, honey best qualifies as an energy‐dense “treat” during low fruiting months. The data lend support to the hypothesis that tools can facilitate chimpanzees’ access to high‐quality fallbacks including insect foods when fruit availability is low. Am J Phys Anthropol 158:685–695, 2015. © 2015 Wiley Periodicals, Inc.
Quantifizierung des Umweltnutzens von gebrauchten Batterien aus Elektrofahrzeugen als gebäudeintegrierte 2nd‐Life‐Stromspeichersysteme
Authors: Kim David , Geissler Achim , Menn Claudio , Hengevoss Dirk 
Published: August 2015

AbstractAufgrund der Energieperspektiven 2050 des schweizerischen Bundesamtes für Energie (BFE) wird das zukünftige Potenzial von gebrauchten Lithium‐Ionen‐Batterien aus Elektrofahrzeugen als stationäre Stromspeicher in Gebäuden untersucht. In drei Szenarien wird der Umweltnutzen für das Jahr 2035 und 2050 ermittelt. Hierzu wird berechnet, wie viel Kapazität an herkömmlichen Speichern durch eine gewisse Kapazität an wiederverwendbaren gebrauchten Batterien substituiert werden kann. Das Substitutionspotenzial wird mit ausgewählten Wirkindikatoren wie dem Treibhauspotenzial (GWP) und dem kumulierten Energieaufwand (CED) analysiert. Im Jahr 2050 können ca. 760 bis 1170 MWh an herkömmlichen Speichern durch 2nd‐Life‐Speicher substituiert werden. Dabei kann das Treibhauspotenzial pro Jahr um ca. 11.000 bis 16.000 t CO2 Äq gesenkt und der kumulierte Energieaufwand um ca. 207.000 bis 305.000 GJ verringert werden. Die Resultate zeigen, dass der Einsatz von 2nd‐Life‐Batterien in stationären Anwendungen einen signifikanten Beitrag zur Reduktion der Umweltbelastung durch Batterien beitragen kann.Quantifying environmental benefits of used batteries coming from electric vehicles as stationary energy storage systems. Based on the “Energy Perspectives 2050” scenarios published by the Swiss Federal Office of Energy (SFOE), used lithium‐ion batteries coming from electric vehicles (EV) are being researched for their future potential to be implemented as stationary energy storage in buildings for. With the help of three investigation scenarios the environmental benefits for the years 2035 and 2050 are evaluated. Calculations are carried out on how much conventional battery storage capacity may be substituted by a certain amount of reusable 2nd‐Life batteries. The substitution potential is analyzed with selected category indicators such as the global warming potential (GWP) and the cumulative energy demand (CED). It is found that between 760 and 1170 MWh conventional energy storage may be substituted by 2nd‐Life by 2050. Thus, the global warming potential may be reduced by between 11,000 to 16,000 t CO2 eq. per year, and the cumulative energy demand between 207,000 to 305,000 GJ. Results show that utilising 2nd‐Life batteries in stationary systems can contribute significantly to reducing the environmental impact of batteries.