bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper export contributes to low copper levels and copper tolerance in Emiliania huxleyi
Authors: Walsh Michael J. , Ahner Beth A. 
Published: April 2014

Previous studies have documented that the coccolithophore Emiliania huxleyi maintains lower cellular copper concentrations and is more tolerant to high copper than are many other species of marine algae. We confirm that in comparison to the diatom Thalassiosira pseudonana, E. huxleyi maintains substantially lower Cu levels while maintaining near maximal growth rates. Using the stable isotope 65Cu as a tracer, we show that a constitutive or rapidly induced mechanism for Cu efflux is present in Cu‐replete E. huxleyi cells. This was revealed during uptake experiments in which the accumulation of the isotopically enriched spike, as measured by the isotope fractionation, exceeded the total accumulated copper. Evidence of efflux was not observed during Cu uptake in T. pseudonana cells. In contrast, copper‐limited E. huxleyi cells exhibited no observable efflux during uptake over the same time period, though net uptake rates were similar to replete cells, suggesting that efflux is modulated by cellular copper needs. This Cu‐efflux mechanism is effective over a wide range of Cu concentrations, as E. huxleyi is able to maintain much lower cellular Cu levels than T. pseudonana during 4 h uptake experiments. Direct measurement of export from copper‐loaded cells provided further evidence of a very effective efflux mechanism in E. huxleyi, while loss of copper from T. pseudonana was considerably less. Improvements to cell washes to remove surface‐bound Cu were implemented.
Instantaneous movement of krill swarms in the Antarctic Circumpolar Current
Authors: Tarling Geraint A. , Thorpe Sally E. 
Published: April 2014

Antarctic krill are known to have strong swimming capabilities, but direct observations of the speed and direction of krill‐swarm movement within their natural environment are rare. We identified and examined 4060 swarms within the main flow of the Antarctic Circumpolar Current (Scotia Sea) using a combination of an EK60 echosounder, a 153.6 kHz acoustic Doppler current profiler, and ground‐truthing nets. Net displacement magnitude (m) and net angle of deviation (d) were determined by vector subtraction from the background flow immediately below them. Values were compared against control data sets in which swarms were absent. With greater background flow, m became increasingly lower than predicted, which suggests that drag influences swarm movement. The characteristics of the flow regime influenced swarm behavior, given that both m and d varied according to the direction of background flow. Furthermore, multiple‐regression analysis indicated that swarm area, the vicinity of the sea‐ice edge, and salinity had a significant influence on m, with levels of displacement being greatest in larger swarms and in low‐salinity regions close to the ice edge. The ice edge is a key environment for Antarctic krill and swarm behavior may assist in retaining this location. Only fluorescence was found to have a significant influence on d, with deviations being greatest in regions of highest fluorescence. This agrees with laboratory observations of krill turning more frequently within food patches. We demonstrate that it is possible to measure instantaneous movement patterns in Antarctic krill swarms and, at large scales, these movements are consistent with current understanding of responses of krill to local stimuli such as sea‐ice and patches of food.
Seasonal cycle of phytoplankton community structure and photophysiological state in the western subarctic gyre of the North Pacific
Authors: Fujiki Tetsuichi , Matsumoto Kazuhiko , Mino Yoshihisa , Sasaoka Kosei , Wakita Masahide , Kawakami Hajime , Honda Makio C. , Watanabe Shuichi , Saino Toshiro 
Published: April 2014

We investigated the seasonal variability of the phytoplankton community in the western subarctic gyre (WSG) of the northwestern North Pacific with respect to structure (abundance, size, and taxonomic composition) and photophysiological state from 2006 to 2012 by using the chemotaxonomy program CHEMTAX, microscopy, and fast‐repetition‐rate fluorometry. Chlorophyll a standing stock (∫Chl a) varied seasonally from 20 to 52 mg m−2 and increased frequently to > 40 mg m−2 in June and July. Diatoms (20–35%) and prymnesiophytes (13–23%) comprised major portions of the ∫Chl a during the bloom period. Diatoms decreased to < 23% during the postbloom period, and prymnesiophytes became the most abundant group (24–35%). Mean Fv : Fm ratios (potential photochemical efficiency of photosystem II) in the mixed layer were relatively high (0.41–0.47) in winter and early spring, decreased rapidly to 0.32–0.39 concomitant with bloom development, and remained at low levels in the summer and autumn, although macronutrients [NO−3, PO3−4, and Si(OH)4] in the mixed layer were not depleted at any time. In June 2012, onboard‐ship iron (Fe)‐enrichment experiments stimulated increases of Chl a concentrations (from 0.64 to 7.15 mg m−3) and Fv : Fm (from 0.33 to 0.44). Seasonal variability of the phytoplankton community in the WSG is controlled mainly by Fe, with light and temperature limitation occurring in winter and early spring. Our study also suggests that the magnitude and duration of blooms in the WSG are strongly affected by Fe availability.
Tidal migration and retention of estuarine zooplankton investigated using a particle‐tracking model
Authors: Kimmerer Wim J. , Gross Edward S. , MacWilliams Michael L. 
Published: April 2014

We used hydrodynamic and particle‐tracking models to investigate vertical movement of plankton and resulting retention in the San Francisco Estuary. The hydrodynamic model was UnTRIM, a three‐dimensional, unstructured grid model, which had been calibrated to historical conditions in this estuary for 1994–1997, a period of widely varying hydrology. Intensive field studies of hydrodynamics and vertical movements of organisms during 1994–1996 provided input data for the models. The particle‐tracking model was run with 14 alternative behaviors for three 45 d periods of contrasting hydrology. The behaviors included passive behavior, several simple tidal migration patterns, and several sinking speeds. Vertical positions of migrating and sinking particles resembled those seen in the field studies for copepods and epibenthos, respectively. Passive particles were advected from the estuary at rates that depended on freshwater flow. All of the non‐passive behaviors caused retention of the particles in the low‐salinity region of the estuary under some flow conditions. Tidal migration was very effective at maintaining position, but model results and a re‐examination of the field data suggested that migration speed should increase with increasing freshwater flow. Continuous sinking was also effective at retention, particularly in deep areas of low tidal velocity. We conclude that the vertical distributions observed in the field studies were a result of active patterns of movement, that these patterns can result in retention, and that retention in a bathymetrically complex estuary can be understood only in the context of the full time‐varying three‐dimensional flow field.
Use of deep autochthonous resources by zooplankton: Results of a metalimnetic addition of 13C to a small lake
Authors: Wilkinson Grace M. , Carpenter Stephen R. , Cole Jonathan J. , Pace Michael L. 
Published: April 2014

Resources in lakes are vertically partitioned due to stratification and trophic interactions. Metalimnetic phytoplankton could be an important resource for zooplankton that either reside in the metalimnion or migrate through this layer. However, it is difficult to estimate metalimnetic resource use, especially using isotope approaches, because surface and deep phytoplankton often have similar isotopic compositions. To overcome this limitation, we experimentally enriched the metalimnetic dissolved inorganic carbon (DIC) 13C pool in Peter Lake to enhance the isotopic separation between metalimnetic phytoplankton and other resources. Metalimnetic δ13C‐DIC peaked at 73.2‰ after the isotope addition and maintained an average enrichment of 34.5‰ above epilimnetic δ13C‐DIC for 62 d. Combining hydrogen and carbon stable isotope values, we estimated the epilimnetic, metalimnetic, and terrestrial resource use by zooplankton, using a Bayesian mixing model that accounted for uncertainties in both consumers and sources. We also measured diel vertical migration and net ecosystem production with in situ bottle incubations over the course of the experiment. Metalimnetic resource use was minor (0–8%) for zooplankton that either resided in the epilimnion of the lake during the day or migrated there at night. For consumers that resided in the metalimnion, metalimnetic phytoplankton accounted for 18–21% of zooplankton isotope composition. The most important resource for all zooplankton was terrestrial organic matter (56–73% of consumer mass), regardless of habitat. This experiment indicates that, in lakes like Peter Lake, metalimnetic autochthonous resources are of minor importance to zooplankton relative to epilimnetic autochthonous and allochthonous resources.
Ocean acidification enhances the growth rate of larger diatoms
Authors: Wu Yaping , Campbell Douglas A. , Irwin Andrew J. , Suggett David J. , Finkel Zoe V. 
Published: April 2014

Ocean acidification is changing the nature of inorganic carbon availability in the global oceans. Diatoms account for µ 40% of all marine primary productivity and are major contributors to the export of atmospheric carbon to the deep ocean. Larger diatoms are more likely to be stimulated by future increases in CO2 availability as a result of their low surface area to volume ratio and lower diffusive flux of CO2 relative to their carbon demand for growth. Here we quantify the effect of the partial pressure of carbon dioxide (PCO2), at levels of 190, 380, and 750 µL L−1, on the growth rate, photosystem II electron transport rate (ETR), and elemental composition for five diatom species ranging over five orders of magnitude in cell volume. Growth rates for all species were enhanced under 750 relative to 190 and 380 µL L−1, with little change in ETR or elemental stoichiometries, indicating an enhanced allocation of photochemical energy to growth under elevated PCO2. PCO2 enhancement of growth rates was size dependent. Under 750 vs. 190 µL L−1 partial pressures, growth rate was enhanced by µ 5% for the smaller diatom species to µ 30% for the largest species examined. The size dependence of CO2‐stimulated growth enhancement indicates that ocean acidification may selectively favor an increase in the growth rates of larger vs. smaller phytoplankton species in the sea, with potentially significant consequences for carbon biochemistry.
A Comment on George DeMartino's “Professional Economic Ethics: The Posnerian and Naïve Perspectives”
Authors: Tinari Frank D. 
Published: April 2014

Abstract
The DeMartino (2013) paper provides a provocative and informative review of the key aspects of the ethical problems faced by applied economists. The purpose of this Comment is not to challenge the contrasts drawn by the author between the two ethics perspectives. Rather, it is our intent to examine more closely the ethical issues that forensic economists may potentially encounter, as identified by the author. DeMartino's paper is rather ambiguous with respect to forensic economic ethics. On the one hand, the paper states that the pressures upon forensic economists are more powerful than those faced by other applied economists; yet, the paper identifies some reasons explaining why there are mechanisms that reduce such pressures.This Comment argues that the author has already identified the broad parameters that explain why ethical problems are less severe for practicing forensic economists. This Comment also expands upon the reasons for this more favorable situation. As a result, the author's conclusion that economics “today is a rogue profession” is excessively broad for two reasons: (1) the focus of the paper is on applied economics, not the entire economics profession, and (2) the phrase would more accurately be stated as: some but not all applied economics comprise a rogue profession.
Localized Critical Theory as an Expression of Community Archaeology Practice: with an Example from Inuvialuit Elders of the Canadian Western Arctic
Authors: Lyons Natasha 
Published: April 2014

AbstractCritical theory has been little used in archaeology, despite its exceptional ability to understand social relations and circumstances, both past and present. In this paper, I develop the concept of a localized critical theory that connects broadscale global processes, such as colonialism and capitalism, to cultural processes that occur at the local level. This expression of archaeological practice has the power to hear, cultivate, and share the voices of individuals and communities as they speak about their respective histories, while recognizing and acknowledging their broader social context. I explore how lnuvialuit Elders' memories are portrayed and interpreted within the lnuvialuit Living History project, focusing particularly on their memories of traditional beluga-whaling in the Mackenzie Delta of Canada’s Western Arctic that were evoked through the identification and handling of ancestral whaling artifacts. I use localized critical theory to explore how Elders’ distinctive perspectives and experiences of beluga-whaling through the course of the mid-twentieth century articulate with and comment on wider historical processes and the agendas of the Canadian nation-state.
Hunter-Gatherer Earth Ovens in the Archaeological Record: Fundamental Concepts
Authors: Black Stephen L. , Thorns Alston V. 
Published: April 2014

AbstractRemains of earth ovens with rock heating elements of various sizes and configurations are common at hunter-gatherer sites around the world. They span the last 30,000 years in the Old World and some 10,000 years in the New World. Although various foods were baked in these ovens, plants predominate. Earth ovens are ethnographically well documented as family-size and bulk cooking facilities, but related technology and its archaeological signatures remain poorly understood and understudied. These ubiquitous features are often mischaracterized as generic cooking facilities termed hearths. It is proposed that, in fact, most rock “hearths” are heating elements of earth ovens. Reliable identification and interpretation of earth ovens requires documentation of heating elements, pit structure, rock linings, and various remnants thereof. Fundamental technological concepts for investigating their archaeological signatures include thermodynamics, construction designs, and life cycles in systemic context, as informed by ethnographic, archaeological, and experimental data. Earth oven technology explains well the primary purpose of labor-intensive thermal storage for long-term cooking and conserving fuel. Information from the extensive archaeological record of earth ovens on the Edwards Plateau of south-central North America illustrates these points.
Stable Isotope Analysis of Turkey (Meleagriscc Gallopavo) Diet from Pueblo II and Pueblo III Sites, Middle San Juan Region, Northwest New Mexico
Authors: McCaffery Harlan , Tykot Robert H. , Durand Gore Kathy , DeBoer Beau R. 
Published: April 2014

AbstractThe transition from the Pueblo 11 Period (A.D. 1050–1150) to the Pueblo III Period (A.D. 1150–1300) in the San Juan Basin marks an intensification of turkey use, evidenced by an increase in the percentage of faunal assemblages representing turkey bones. We examine stable carbon (δ13C) and nitrogen ( δ15N) isotopic values of turkey bones from three ancestral Puebloan sites in the Middle San Juan Region to test the hypothesis that this intensification is linked to an increase in the amount of maize in the turkeys’ diets. We find no significant change in δ13C or δ15N across the two time periods, and all of the specimens’ values indicate maize consumption. A plot of bone apatite δ13C against collagen δ13C is consistent with a model of diets high in C4protein, indicating that the turkeys did not use an alternative source of protein to maize and/or fauna that fed on maize. The reliance of both humans and turkeys on maize indicates a degree of turkey-human interdependency not previously known in the Middle San Juan Region. Future inquiries into the paleodiet of turkeys should target times and places where there is likely to have been a transition from hunting to domestication.
Unnotched Triangular Points on Village Sites
Authors: Engelbrecht William 
Published: April 2014

AbstractUnnotched triangular arrowpoínts and point fragments are sometimes found in large numbers on village sites in the Midwest and East. The possible reason or reasons for this are rarely considered. These points were used for both warfare and hunting. An attack on a village with a volley of arrows provides the most obvious explanation for large numbers of points and point fragments. Alternatively, using arrowpoints that detached within their target prey would have resulted in points and point fragments being brought back to a village in meat. These possibilities are considered in explaining the large number of points from an iroquoian village site in western New York.
Semiconductor‐insulator Interfaces, High κ Dielectrics on (In)GaAs
Authors: Pi T.W. , Lin T.D. , Chang W.H. , Chang Y.C. , Hong M. , Kwo J. 
Published: April 2014

AbstractRecent development of high κ dielectric oxides on (In)GaAsis reviewed in the fields of electronic structure and electric performance; this includes studies of (In)GaAssurfaces with various surface reconstructions, different orientations, and Indium contents, and of high κ/(In)GaAsinterfaces. The oxide deposition was carried out using atomic‐layer deposition (ALD) and molecular beam epitaxy (MBE) viaex‐situorin‐situmethods. For the former approach, the semiconductor surfaces prior to the oxide deposition were obtained via chemical, arsenic‐cap or annealing treatments. For the latter, the high k's were deposited on pristine freshlyMBE‐grown (In)GaAssurfaces without any treatments. Surface being treated or not clearly determines the quality of the oxide interface which delivers different interfacial electronic structure and electric performance. Without exception, theex‐situtreated samples show remnant native oxides, which are never found in thein‐situsamples. The electronic structure has been investigated using photoemission measurements, in which the photon energy was provided byX‐ray and synchrotron radiation. The discussion on high κ/(In)GaAsinterfaces has been further extended to the electrical characterization including extraction of interfacial trap densities (Dit's). Especially, the distinct electrical characteristics of the In0.2Ga0.8As metal‐oxide‐semiconductor capacitors (MOSCAPs) usingMBE‐Ga2O3(Gd2O3) andALD‐Al2O3as the gate are elucidated. Finally, a summary and bench‐marking of the recent advances on enhancement modeIII‐V(In)GaAsMOSFETsis given, which reveals the great potential of inversion‐channel (In)GaAsMOSFETsfor ultimate complementaryMOS(CMOS) applications.
Advances in Planar Filters
Authors: Crnojević‐Bengin Vesna , Janković Nikolina 
Published: April 2014

Many microstrip filter configurations exist that exhibit advanced filtering characteristics, rely on new design techniques, or use original methods for filter miniaturization. For each filter type (lowpass, highpass, bandpass, and bandstop), we start with an overview of conventional planar filters, which are often used as a basis for the development of novel configurations, and then proceed to more advanced solutions. We classify the various advanced solutions found in the literature according to the underlying principle of design/operation: i) conventional filters using advanced geometries; ii) filters based on advanced theoretical concepts, such as the slow‐wave effect, defected ground structures (DGSs), electromagnetic‐bandgap (EBG) structures, or metamaterials (MTMs); and iii) filters based on advanced materials and technologies, such as superconducting, ferroelectric materials, and ferromagnetic materials.Finally, we present some of the advanced solutions not covered by the classification given above. We provide an overview of surface‐integrated waveguide (SIW) filters, followed by the discussion of various tunable and reconfigurable filter topologies. In the end, we present state‐of‐the art multiband filters.
The solar meridional circulation and sunspot cycle variability
Authors: Hathaway D. H. , Upton L. 
Published: April 2014

AbstractWe have measured the meridional motions of the magnetic elements in the Sun's surface layers since 1996 and find systematic and substantial variations. In general the meridional flow speed is fast at cycle minima and slow at cycle maxima. We find that these systematic variations are characterized by a weakening of the meridional flow on the poleward sides of the active (sunspot) latitudes. This can be interpreted as an inflow toward the sunspot zones superimposed on a more general poleward meridional flow profile. We also find variations in the meridional flow which vary from cycle to cycle. The meridional flow was slower at both the minimum and maximum of cycle 23 compared to similar phases of cycles 21, 22, and 24. Models of the magnetic flux transport by a variable meridional flow suggest that it can significantly modulate the size and timing of the following sunspot cycle through its impact on the Sun's polar magnetic fields. We suggest that the meridional flow variations observed in cycle 23 contributed to the weak polar fields at the end of the cycle which then produced a weak cycle 24 and the extraordinary cycle 23/24 minimum.
Temporal evolution of fractality in the Earth's magnetosphere and the solar photosphere
Authors: Domínguez Macarena , Muñoz Víctor , Valdivia Juan Alejandro 
Published: April 2014

AbstractThe study of complexity in two aspects of the magnetic activity in the Sun‐Earth system is presented. We compare the temporal evolution of the magnetic fluctuations in the Earth's magnetosphere and the spatial distribution of the magnetic field in the solar photosphere, by calculating fractal dimensions from the data. It is found that the fractal dimension of the Dst data decreases during magnetic storm states and is well correlated with other indexes of solar activity, such as the solar flare and coronal indexes. This correlation holds for individual storms, full‐year data, and the complete 23rd solar cycle. The fractal dimension from solar magnetogram data also correlates well with both the Dst index and solar flare index, although the correlation is much more clear at the larger temporal scale of the 23rd solar cycle, showing a clear increase around solar maximum.