bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep crustal deformation of the Longmen Shan, eastern margin of the Tibetan Plateau, from seismic reflection and Finite Element modeling
Authors: Feng Shao‐ying , Zhang Pei‐zhen , Liu Bao‐jin , Wang Ming , Zhu Shou‐biao , Ran Yong‐kan , Wang Wei‐tao , Zhang Zhu‐qi , Zheng Wen‐jun , Zheng De‐wen , Zhang Hui‐ping , Tian Xiao‐feng
Published: December 2015

Rivaling the Himalaya in relief, the Longmen Shan is probably one of the most enigmatic mountain ranges in the world: high mountains reach more than 4000 m relief but without adjacent foreland subsidence and with only slow active convergence. What are geological and geodynamic processes that built the Longmen Shan? Coseismic deformation associated with the 2008 Wenchuan earthquake could hold clues to answer these questions. The primary features associated with the 2008 Wenchuan earthquake rupture have been narrowly distributed coseismic deformation and predominantly vertical displacements that could be interpreted as the result of slips on high‐angle listric seismogenic faults. Deep sounding seismic reflection profiling across the seismogenic faults indeed reveals high‐angle listric reverse faulting in the brittle upper crust and east‐dipping reflectors that we interpret as ductile shearing, in the viscous lower crust. In conjunction with a visco‐elastic finite element modeling of coseismic displacements associated with the Wenchuan earthquake, we show that the high‐angle listric nature of earthquake faults produces insignificant horizontal shortening across the fault and facilitates upward slips along the fault that both explain the localized coseismic deformation and vertical displacement, as well as the presence of high mountains without adjacent foreland flexure. We suggest that the formation of the Longmen Shan may be better understood in terms of partitioned lithospheric pure‐shear thickening in which upward high‐angle listric faulting of brittle upper crust is linked to thickening of the more viscous lithospheric mantle through downward ductile shearing of rheologically deformable lower crust.
Forecasting the path of a laterally propagating dike
Authors: Heimisson Elías Rafn , Hooper Andrew , Sigmundsson Freysteinn
Published: December 2015

An important aspect of eruption forecasting is predicting the path of propagating dikes. We show how lateral dike propagation can be forecast using the minimum potential energy principle. We compare theory to observed propagation paths of dikes originating at the Bárðarbunga volcano, Iceland, in 2014 and 1996, by developing a probability distribution for the most likely propagation path. The observed propagation paths agree well with the model prediction. We find that topography is very important for the model, and our preferred forecasting model considers its influence on the potential energy change of the crust and magma. We tested the influence of topography by running the model assuming no topography and found that the path of the 2014 dike could not be hindcasted. The results suggest that lateral dike propagation is governed not only by deviatoric stresses but also by pressure gradients and gravitational potential energy. Furthermore, the model predicts the formation of curved dikes around cone‐shaped structures without the assumption of a local deviatoric stress field. We suggest that a likely eruption site for a laterally propagating dike is in topographic lows. The method presented here is simple and computationally feasible. Our results indicate that this kind of a model can be applied to mitigate volcanic hazards in regions where the tectonic setting promotes formation of laterally propagating vertical intrusive sheets.
Stress‐driven relaxation of heterogeneous upper mantle and time‐dependent afterslip following the 2011 Tohoku earthquake
Authors: Hu Yan , Bürgmann Roland , Uchida Naoki , Banerjee Paramesh , Freymueller Jeffrey T.
Published: December 2015

Understanding of postseismic deformation following great subduction zone earthquakes is complicated by the combined effects of viscoelastic relaxation of earthquake‐induced stresses in the upper mantle and time‐dependent afterslip on the megathrust. We integrate geodetic observations and constraints on afterslip from small repeating earthquakes on the megathrust to better distinguish contributions from these two postseismic processes. We have developed a three‐dimensional, spherical viscoelastic finite element model to study the postseismic deformation of the 2011 Mw9.0 Tohoku earthquake that has been recorded at unprecedented high resolution in space and time. We model stress‐driven afterslip in a 2 km thick weak shear zone away from historic rupture zones on the megathrust. We model both the viscoelastic relaxation of the upper mantle and shear zone deformation with a transient Burgers body rheology. The transient Kelvin viscosity is assumed to be one order of magnitude lower than that of the Maxwell viscosity. Viscoelastic relaxation of the mantle wedge alone causes postseismic uplift and seaward motion in the upper plate, opposite to the pattern from relaxation of just the oceanic upper mantle. Afterslip on the fault produces uplift updip of the afterslip zone and subsidence over its downdip edge and mostly seaward motion above the afterslip zone. The best fit Maxwell viscosity of the shear zone at depths ≤50 km is 1017 Pa s, constrained by afterslip estimates from repeating earthquakes. The optimal viscosities of the deep weak shear zone, continental mantle wedge, and oceanic upper mantle are determined to be 5 × 1017 Pa s, 3 × 1019 Pa s, and 5 × 1019 Pa s, respectively. The stress‐driven afterslip in the shear zone is up to ~3.5 m in the first 2 years after the earthquake, equivalent to an Mw8.4. Our model reproduces the first‐order pattern of the GPS observations both in horizontal and in vertical directions. Seafloor geodetic observations of subsidence and landward motions near the high‐slip zone of the earthquake provide evidence for a low‐viscosity asthenosphere below the oceanic lithosphere.
Tomographic image of a seismically active volcano: Mammoth Mountain, California
Authors: Dawson Phillip , Chouet Bernard , Pitt Andrew
Published: December 2015

High‐resolution tomographic P wave, S wave, and VP/VS velocity structure models are derived for Mammoth Mountain, California, using phase data from the Northern California Seismic Network and a temporary deployment of broadband seismometers. An anomalous volume (5.1 × 109 to 5.9 × 1010m3) of low P and low S wave velocities is imaged beneath Mammoth Mountain, extending from near the surface to a depth of ∼2 km below sea level. We infer that the reduction in seismic wave velocities is due to the presence of CO2 distributed in oblate spheroid pores with mean aspect ratio α = 1.6 × 10−3 to 7.9 × 10−3 (crack‐like pores) and mean gas volume fraction ϕ = 8.1 × 10−4 to 3.4 × 10−3. The pore density parameter κ = 3ϕ/(4πα) = na3=0.11, where n is the number of pores per cubic meter and a is the mean pore equatorial radius. The total mass of CO2 is estimated to be 4.6 × 109 to 1.9 × 1011 kg. The local geological structure indicates that the CO2 contained in the pores is delivered to the surface through fractures controlled by faults and remnant foliation of the bedrock beneath Mammoth Mountain. The total volume of CO2 contained in the reservoir suggests that given an emission rate of 500 tons day−1, the reservoir could supply the emission of CO2 for ∼25–1040 years before depletion. Continued supply of CO2 from an underlying magmatic system would significantly prolong the existence of the reservoir.
Tiber delta CO2‐CH4 degassing: A possible hybrid, tectonically active Sediment‐Hosted Geothermal System near Rome
Authors: Ciotoli G. , Etiope G. , Marra F. , Florindo F. , Giraudi C. , Ruggiero L.
Published: December 2015

Fiumicino town in the Tiber River delta, near Rome International Airport (Italy), is historically affected by large amounts of carbon dioxide (CO2) in the ground and gas eruptions triggered by shallow drilling. While it is known that CO2 originates from carbonate thermometamorphism and/or mantle degassing, the origin of methane (CH4) associated with CO2 is uncertain and the outgassing spatial distribution is unknown. Combining isotope gas geochemistry, soil gas, and structural‐stratigraphic analyses, we provide evidence for a hybrid fluid source system, classifiable as Sediment‐Hosted Geothermal System (SHGS), where biotic CH4 from sedimentary rocks is carried by deep geothermic CO2 through active segments of a half‐graben. Molecular and isotopic composition of CH4 and concentration of heavier alkanes (ethane and propane), obtained from gas vents and soil gas throughout the delta area, reveal that thermogenic CH4 (up to 3.7 vol% in soil gas; δ13CCH4: −37 to −40‰ VPDB‐Vienna Peedee Belemnite, and δ2HCH4: −162 to −203‰ VSMOW ‐ Vienna Standard Mean Ocean Water in gas vents) prevails over possible microbial and abiotic components. The hydrocarbons likely result from known Meso‐Cenozoic petroleum systems of the Latium Tyrrhenian coast. Overmaturation of source rocks or molecular fractionation induced by gas migration are likely responsible for increased C1/C2+ ratios. CO2 and CH4 soil gas anomalies are scattered along NW‐SE and W‐E alignments, which, based on borehole, geomorphologic, and structural‐stratigraphic analyses, coincide with active faults of a half‐graben that seems to have controlled the recent evolution of the Tiber delta. This SHGS can be a source of considerable greenhouse gas emissions to the atmosphere and hazards for humans and buildings.
Satellite assessment of sea spray aerosol productivity: Southern Ocean case study
Authors: Witek Marcin L. , Diner David J. , Garay Michael J.
Published: December 2015

Despite many years of observations by multiple sensors, there is still substantial ambiguity regarding aerosol optical depths (AOD) over remote oceans, in particular, over the pristine Southern Ocean. Passive satellite retrievals (e.g., Multiangle Imaging Spectroradiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS)) and global aerosol transport models show a distinct AOD maximum around the 60°S latitude band. Sun photometer measurements performed by the Maritime Aerosol Network (MAN), on the other hand, indicate no increased AODs over the Southern Ocean. In this study elevated Southern Ocean AODs are examined from the modeling perspective. The primary aerosol component over the Southern Ocean is sea spray aerosol (SSA). Multiple simulations of SSA concentrations and optical depths are carried out using a single modeling framework, the Navy Aerosol Analysis and Prediction System (NAAPS) model. Several SSA emission functions are examined, including recently proposed formulations with sea surface temperature corrections. The differences between NAAPS simulations are primarily due to different SSA emission formulations. The results are compared against satellite‐derived AODs from the MISR and MODIS instruments. MISR and MODIS AOD retrievals are further filtered to eliminate retrievals potentially affected by cloud contamination and cloud adjacency effects. The results indicate a very large impact of SSA emission parameterization on the simulated AODs. For some scenarios, the Southern Ocean AOD maximum almost completely disappears. Further MISR and MODIS AOD quality screening substantially improves model/satellite agreement. Based on these comparisons, an optimal SSA emission function for global aerosol transport models is recommended.
Using data insertion with the NAME model to simulate the 8 May 2010 Eyjafjallajökull volcanic ash cloud
Authors: Wilkins K. L. , Watson I. M. , Kristiansen N. I. , Webster H. N. , Thomson D. J. , Dacre H. F. , Prata A. J.
Published: December 2015

A data insertion method, where a dispersion model is initialized from ash properties derived from a series of satellite observations, is used to model the 8 May 2010 Eyjafjallajökull volcanic ash cloud which extended from Iceland to northern Spain. We also briefly discuss the application of this method to the April 2010 phase of the Eyjafjallajökull eruption and the May 2011 Grímsvötn eruption. An advantage of this method is that very little knowledge about the eruption itself is required because some of the usual eruption source parameters are not used. The method may therefore be useful for remote volcanoes where good satellite observations of the erupted material are available, but little is known about the properties of the actual eruption. It does, however, have a number of limitations related to the quality and availability of the observations. We demonstrate that, using certain configurations, the data insertion method is able to capture the structure of a thin filament of ash extending over northern Spain that is not fully captured by other modeling methods. It also verifies well against the satellite observations according to the quantitative object‐based quality metric, SAL—structure, amplitude, location, and the spatial coverage metric, Figure of Merit in Space.
Origins of tropospheric ozone interannual variation over Réunion: A model investigation
Authors: Liu Junhua , Rodriguez Jose M. , Thompson Anne M. , Logan Jennifer A. , Douglass Anne R. , Olsen Mark A. , Steenrod Stephen D. , Posny Françoise
Published: December 2015

Observations from long‐term ozonesonde measurements show robust variations and trends in the evolution of ozone in the middle and upper troposphere over Réunion Island (21.1°S, 55.5°E) in June–August. Here we examine possible causes of the observed ozone variation at Réunion Island using hindcast simulations by the stratosphere‐troposphere Global Modeling Initiative chemical transport model for 1992–2014, driven by assimilated Modern‐Era Retrospective Analysis for Research and Applications meteorological fields. Réunion Island is at the edge of the subtropical jet, a region of strong stratospheric‐tropospheric exchange. Our analysis implies that the large interannual variation (IAV) of upper tropospheric ozone over Réunion is driven by the large IAV of the stratospheric influence. The IAV of the large‐scale, quasi‐horizontal wind patterns also contributes to the IAV of ozone in the upper troposphere. Comparison to a simulation with constant emissions indicates that increasing emissions do not lead to the maximum trend in the middle and upper troposphere over Réunion during austral winter implied by the sonde data. The effects of increasing emission over southern Africa are limited to the lower troposphere near the surface in August–September.
High‐resolution wind hindcast over the Bohai Sea and the Yellow Sea in East Asia: Evaluation and wind climatology analysis
Authors: Li Delei , von Storch Hans , Geyer Beate
Published: December 2015

A 34 year (1979–2012) high‐resolution (7 km grid) atmospheric hindcast over the Bohai Sea and the Yellow Sea (BYS) has been performed using COSMO‐CLM (CCLM) forced by ERA‐Interim reanalysis data (ERA‐I). The accuracy of CCLM in surface wind reproduction and the added value of dynamical downscaling to ERA‐I have been investigated through comparisons with the QuikSCAT Level2B 12.5 km version 3 (L2B12v3) swath data and in situ observations. The results revealed that CCLM has a reliable ability to reproduce the regional wind characteristics over the BYS. Added value to ERA‐I has been detected in the coastal areas with complex orography. CCLM wind quality had strong seasonal variability, with better performance in the summer relative to ERA‐I, even in the offshore areas. CCLM was better able to represent light and moderate winds but had even more added value for strong winds relative to ERA‐I. The spatial digital filter method was used to investigate the scale of the added value, and the results show that CCLM adds value to ERA‐I mainly in medium scales of wind variability. Furthermore, wind climatology was investigated, and significant increasing trends in the south Yellow Sea especially in winter and spring were found for seasonal mean wind speeds.
Evaluation of the performance characteristics of the European Lightning Detection Network EUCLID in the Alps region for upward negative flashes using direct measurements at the instrumented Säntis Tower
Authors: Azadifar Mohammad , Rachidi Farhad , Rubinstein Marcos , Paolone Mario , Diendorfer Gerhard , Pichler Hannes , Schulz Wolfgang , Pavanello Davide , Romero Carlos
Published: December 2015

In this paper, we present a performance analysis of the European Cooperation for Lightning Detection (EUCLID) lightning detection network using data obtained on lightning currents measured at the Säntis Tower (located in northeastern of Switzerland) from June 2010 to December 2013. In the considered period of analysis, a total number of 269 upward negative flashes were recorded at the Säntis Tower. The performance of the EUCLID lightning detection network is evaluated in terms of detection efficiency, location accuracy, and peak current estimates for upward flashes. Excluding flashes containing only an initial continuous current with no superimposed pulses exceeding 2 kA, the flash detection efficiency for upward flashes is estimated to be 97%. The recorded flashes contained a total of 2795 pulses (including return strokes and International Conference on Communications pulses characterized by risetimes lower than 8 µs and peaks greater than 2 kA). The overall pulse detection efficiency was found to be 73%. For pulses with peak values higher than 5 kA, the pulse detection efficiency was found to be about 83%. Peak current estimates provided by the EUCLID network were found to be significantly larger than their directly measured counterparts. This overestimation might be attributed to the enhancement of the radiated electromagnetic fields associated with the presence of the tower and the mountain. The median of the absolute distance error, defined as the median distance between the Säntis Tower location and the EUCLID's stroke locations, was found to be 186 m, the majority of large location errors being associated with measured current peaks lower than 10 kA. The analysis revealed also that the location accuracy of the EUCLID network improved significantly in 2013 as a result of an upgrade in the location algorithms to take into account propagation effects.
Effects of permafrost aggradation on peat properties as determined from a pan‐Arctic synthesis of plant macrofossils
Authors: Treat C. C. , Jones M. C. , Camill P. , Gallego‐Sala A. , Garneau M. , Harden J. W. , Hugelius G. , Klein E. S. , Kokfelt U. , Kuhry P. , Loisel J. , Mathijssen P. J. H. , O'Donnell J. A. , Oksanen P. O. , Ronkainen T. M. , Sannel A. B. K. , Talbot J. , Tarnocai C. , Väliranta M.
Published: December 2015

Permafrost dynamics play an important role in high‐latitude peatland carbon balance and are key to understanding the future response of soil carbon stocks. Permafrost aggradation can control the magnitude of the carbon feedback in peatlands through effects on peat properties. We compiled peatland plant macrofossil records for the northern permafrost zone (515 cores from 280 sites) and classified samples by vegetation type and environmental class (fen, bog, tundra and boreal permafrost, and thawed permafrost). We examined differences in peat properties (bulk density, carbon (C), nitrogen (N) and organic matter content, and C/N ratio) and C accumulation rates among vegetation types and environmental classes. Consequences of permafrost aggradation differed between boreal and tundra biomes, including differences in vegetation composition, C/N ratios, and N content. The vegetation composition of tundra permafrost peatlands was similar to permafrost‐free fens, while boreal permafrost peatlands more closely resembled permafrost‐free bogs. Nitrogen content in boreal permafrost and thawed permafrost peatlands was significantly lower than in permafrost‐free bogs despite similar vegetation types (0.9% versus 1.5% N). Median long‐term C accumulation rates were higher in fens (23 g C m−2 yr−1) than in permafrost‐free bogs (18 g C m−2 yr−1) and were lowest in boreal permafrost peatlands (14 g C m−2 yr−1). The plant macrofossil record demonstrated transitions from fens to bogs to permafrost peatlands, bogs to fens, permafrost aggradation within fens, and permafrost thaw and reaggradation. Using data synthesis, we have identified predominant peatland successional pathways, changes in vegetation type, peat properties, and C accumulation rates associated with permafrost aggradation.
Spatiotemporal variations of phytoplankton in the East China Sea and the Yellow Sea revealed by lipid biomarkers
Authors: Wu Peng , Bi Rong , Duan Shanshan , Jin Haiyan , Chen Jianfang , Hao Qiang , Cai Yuming , Mao Xinyan , Zhao Meixun
Published: December 2015

The East China Sea (ECS) and the Southern Yellow Sea (SYS) ecosystem is undergoing dramatic changes, but the spatiotemporal patterns and forcing mechanisms of phytoplankton variations remain understudied. Phytoplankton lipid biomarkers are useful proxies for productivity and community structure changes, and they were measured in suspended particles of more than 81 sites from spring and summer of 2011 in the ECS and SYS. In spring, the concentrations of brassicasterol (4.7–127 ng L−1) and dinosterol (0.7–37 ng L−1) were markedly higher in the northern and central SYS, while C37 alkenones (0–15 ng L−1) were detected at only seven sites in the ECS. In summer, brassicasterol (25.3–1178 ng L−1) and dinosterol (0–125 ng L−1) showed high values off the Changjiang River Estuary (CRE), while C37 alkenones (0–410 ng L−1) had high values in the northwest and central SYS. The mean concentrations of the three lipid biomarkers in summer were 3 to 61 times higher than those in spring. Spatiotemporal patterns of biomarkers reveal higher ratios of diatom/dinoflagellate and diatom/haptophyte in higher productivity areas, off the CRE in summer and the northern and central SYS in spring. This study validates the applicability of brassicasterol, dinosterol, and alkenones as proxies of productivity and community structure of the three phytoplankton taxa: diatoms, dinoflagellates, and haptophytes. The results indicate that nutrients (in summer) and turbidity‐induced photosynthetic available radiation (in spring) play important roles in regulating spatiotemporal variations of phytoplankton in the ECS and SYS.
Effect of Graphitization on the Microstructure and Properties of Mo2C‐Modified C/C–Cu Composites
Authors: Zhou Wen Yan , Peng Ke , Ran Li Ping , Ge Yi Cheng , Yi Mao Zhong
Published: December 2015

Carbon/carbon–copper(C/C–Cu) composites are fabricated by infiltration of Cu into Mo2C interlayer‐modified carbon/carbon(C/C) preforms. Effect of graphitization on the microstructure and properties of the C/C–Cu composites is studied. The C/C–Cu composite with graphitization shows lower electrical resistivity, thermal expansion coefficient, friction coefficient, and an obvious higher thermal conductivity due to higher graphitization degree. However, it presents lower flexural strength, impact toughness, and higher wear rate. The composite with graphitization exhibits mainly abrasive wear while that without graphitization exhibits mainly adhesion wear, and both composites show oxidation wear.
Advanced Materials for the Recognition and Capture of Whole Cells and Microorganisms
Authors: Bole Amanda L. , Manesiotis Panagiotis
Published: December 2015

Selective cell recognition and capture has recently attracted significant interest due to its potential importance for clinical, diagnostic, environmental, and security applications. Current methods for cell isolation from complex samples are largely dependent on cell size and density, with limited application scope as many of the target cells do not exhibit appreciable differences in this respect. The most recent and forthcoming developments in the area of selective recognition and capture of whole cells, based on natural receptors, as well as synthetic materials utilising physical and chemical properties of the target cell or microorganism, are highlighted. Particular focus is given to the development of cell complementary surfaces using the cells themselves as templating agents, by means of molecular imprinting, and their combination with sensing platforms for rapid cell detection in complex media. The benefits and challenges of each approach are discussed and a perspective of the future of this research area is given.
Generating Light from Upper Excited Triplet States: A Contribution to the Indirect Singlet Yield of a Polymer OLED, Helping to Exceed the 25% Singlet Exciton Limit
Authors: Jankus Vygintas , Aydemir Murat , Dias Fernando B. , Monkman Andrew P.
Published: December 2015

The mechanisms by which light is generated in an organic light emitting diode have slowly been elucidated over the last ten years. The role of triplet annihilation has demonstrated how the “spin statistical limit” can be surpassed, but it cannot account for all light produced in the most efficient devices. Here, a further mechanism is demonstrated by which upper excited triplet states can also contribute to indirect singlet production and delayed fluorescence. Since in a device the population of these TN states is large, this indirect radiative decay channel can contribute a sizeable fraction of the total emission measured from a device. The role of intra‐ and interchain charge transfer states is critical in underpinning this mechanism.
Multicolor Electroluminescence from Intermediate Band Solar Cell Structures
Authors: López Nair , Yu Kin Man , Tanaka Tooru , Walukiewicz Wladyslaw
Published: December 2015

Intermediate band solar cells are a new generation of photovoltaics that allow for better utilization of the solar spectrum. The key and most challenging requirement for these cells is an efficient optical coupling between the intermediate band and the charge conducting bands. GaNAs based intermediate band solar cells have been used to generate electroluminescence. Two electroluminescence peaks are generated in the structure with electrically blocked intermediate band. The peaks are observed for both forward and reverse bias configuration and are attributed to optical transitions from the conduction to the intermediate band, and from the intermediate band to the valence band. The origin of the electroluminescence is confirmed by the temperature dependence of the electroluminescence peak energies that is consistent with the band anticrossing model of the intermediate band formation in dilute nitride alloys. This is the first direct observation of the optical transitions required for the operation of intermediate band solar cells. The results also demonstrate that properly modified intermediate band solar cell structures could be used as multicolor light emitters.
Upper molar morphology of the early oligocene egyptian anthropoid Qatrania wingi
Authors: Beard K. Christopher , Coster Pauline M. C.
Published: December 2015

Objectives

Qatrania wingi is a poorly documented fossil anthropoid known only from Quarry E in the Jebel Qatrani Formation, Fayum Depression, Egypt. This report augments our knowledge of the dental morphology of Qatrania in order to clarify its phylogenetic relationships with other early African anthropoids.

Materials and Methods

YPM 18008 from Quarry E is the first example of an upper molar fragment that can reasonably be assigned to Qatrania wingi. Maximum parsimony phylogenetic analyses incorporating the new data from YPM 18008 were performed.

Results

If YPM 18008 is treated as a separate OTU, it is reconstructed as a member of Qatraniinae (the parapithecid clade containing Qatrania and Apidium). The only qatraniine known to occur at Quarry E is Qatrania wingi, and YPM 18008 is allocated to this species based on its size, provenance, and morphology. Despite its small size and early stratigraphic occurrence, the upper molar morphology of Qatrania wingi is highly derived with respect to that of other parapithecids aside from Apidium. Like that of Apidium, the upper molar morphology of Qatrania bears multiple neomorphic cusps and cuspules. These features appear to be synapomorphies linking Apidium and Qatrania to the exclusion of other parapithecids for which upper molar morphology is known, namely Simonsius grangeri and Biretia spp.

Discussion

YPM 18008 supports the recent proposal of a Qatrania + Apidium clade within Parapithecidae. This conflicts with earlier hypotheses, in which Qatrania was reconstructed as being phylogenetically basal to a clade including the younger, larger‐bodied parapithecid taxa Apidium, Parapithecus, and Simonsius. Am J Phys Anthropol 159:714–721, 2016. © 2015 Wiley Periodicals, Inc.
Neutron microtomography‐based virtual extraction and analysis of a cercopithecoid partial cranium (STS 1039) embedded in a breccia fragment from sterkfontein member 4 (South Africa)
Authors: Beaudet Amélie , Braga José , de Beer Frikkie , Schillinger Burkhard , Steininger Christine , Vodopivec Vladimira , Zanolli Clément
Published: December 2015

The Plio‐Pleistocene karstic sedimentary deposits of Sterkfontein Cave, South Africa, yielded numerous fossil primate specimens embedded in blocks of indurated breccia, including the partial cercopithecoid cranium labelled STS 1039. Because the surrounding matrix masks most of its morphology, the specimen remains taxonomically undetermined. While the use of X‐ray microtomography did not allow extracting any structural information about the specimen, we experimented a new investigative technique based on neutron microtomography. Using this innovative approach, we successfully virtually extracted, reconstructed in 3D and quantitatively assessed the preserved dentognathic structural morphology of STS 1039, including details of its postcanine maxillary dentition. Following comparative analyses with a number of Plio‐Pleistocene and extant cercopithecoid taxa, we tentatively propose a taxonomic attribution to the taxon Cercopithecoides williamsi. Our experience highlights the remarkable potential of this novel imaging method to extract diagnostic information and to identify the fossil remains embedded in hard breccia from the South African hominin‐bearing cave sites. Am J Phys Anthropol 159:737–745, 2016. © 2015 Wiley Periodicals, Inc.
Fabrication and analysis of polymer microstructures through ion microprobe techniques
Authors: Stori Elis Moura , de Souza Claudia Telles , Dias Johnny Ferraz
Published: December 2015

In this work, we explored the capabilities of energetic focused beams of light ions for the fabrication and analysis of microstructures produced on commercial polyethylene terephthalate (PET) foils. To that end, single lines and multi‐structure patterns were drawn directly on the foils using Proton Beam Writing (PBW) techniques followed by chemical etching. The characterization of the microstructures was carried out with on‐axis Scanning Transmission Ion Microscopy (STIM) employing H+1, He+2, and Li+3 ions in the MeV range. Scanning Electron Microscopy (SEM) was employed as well. The results show that a polymer like PET can be patterned trough a proper combination of irradiation parameters and etching times. However, aspect ratios obtained in this way are quite poor. Moreover, STIM images obtained from different regions of the ion energy spectra reveal patterns and cavities seen neither by conventional STIM, where the whole energy spectrum is used, nor by SEM. Moreover, striking differences are observed when different ions are used for STIM analysis. The results suggest that heavier ions provide additional information of the structures under analysis when compared with usual STIM employing protons. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43253.
Mitochondria and the non‐genetic origins of cell‐to‐cell variability: More is different
Authors: Guantes Raúl , Díaz‐Colunga Juan , Iborra Francisco J.
Published: December 2015

Gene expression activity is heterogeneous in a population of isogenic cells. Identifying the molecular basis of this variability will improve our understanding of phenomena like tumor resistance to drugs, virus infection, or cell fate choice. The complexity of the molecular steps and machines involved in transcription and translation could introduce sources of randomness at many levels, but a common constraint to most of these processes is its energy dependence. In eukaryotic cells, most of this energy is provided by mitochondria. A clonal population of cells may show a large variability in the number and functionality of mitochondria. Here, we discuss how differences in the mitochondrial content of each cell contribute to heterogeneity in gene products. Changes in the amount of mitochondria can also entail drastic alterations of a cell's gene expression program, which ultimately leads to phenotypic diversity.

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Reprogramming the genetic code: The emerging role of ribosomal frameshifting in regulating cellular gene expression
Authors: Advani Vivek M. , Dinman Jonathan D.
Published: December 2015

Reading frame maintenance is a critical property of ribosomes. However, a number of genetic elements have been described that can induce ribosomes to shift on mRNAs, the most well understood of which are a class that directs ribosomal slippage by one base in 5' (‐1) direction. This is referred to as programmed ‐1 ribosomal frameshifting (‐1 PRF). Recently, a new ‐1 PRF promoting element was serendipitously discovered in a study examining the effects of stretches of adenosines in the coding sequences of mRNAs. Here, we discuss this finding, recent studies describing how ‐1 PRF is used to control gene expression in eukaryotes, and how ‐1 PRF is itself regulated. The implications of dysregulation of ‐1 PRF on human health are examined, as are possible new areas in which novel ‐1 PRF promoting elements might be discovered.

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Biolabile peptidyl delivery systems toward sequential drug release
Authors: Ragozin Elena , Redko Boris , Tuchinsky Elena , Rozovsky Alex , Albeck Amnon , Grynszpan Flavio , Gellerman Gary
Published: December 2015

Compact carriers for peptidyl delivery systems (PDSs) loaded with various drugs were synthesized using a simple and convenient solid phase organic synthesis strategy, including semi‐orthogonal functional group protection schemes. Each attachment point of the compact carrier can thus be bound to an anticancer agent through a biodegradable covalent link. Chemo‐ and biostability experiments of a model peptidyl platform loaded with three different drugs revealed pH and liver homogenate (metabolic) dependent sequential release behavior. The versatility of this approach will serve to expedite the preparation of PDS libraries. This approach may prove useful for applications suitable for personalized medicine where multiple drug delivery is required in a sequential and controlled fashion. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 119–132, 2016.
Acute stroke from paradoxical embolism of dense fibrous tissue following pacemaker lead extraction: salvation by mechanical thrombectomy
Authors: Dayal Nicolas B. , Narata Ana Paula , Burri Haran
Published: December 2015

Key Clinical Message

Systemic embolization is a dreaded complication of transvenous lead extraction (TLE), even without visible vegetations. Preoperative patent foramen ovale evaluation is important, justifying neurological surveillance or consideration of surgical extraction in selected cases. In case of stroke after TLE, mechanical thrombectomy is a successful therapy, and should be readily available.
Improving the material efficiency of recycled furnish for papermaking through enzyme modifications
Authors: Verma Piyush Kumar , Bhardwaj Nishi Kant , Singh Surendra Pal
Published: December 2015

Fibre fines and fibrils within recycled cellulosic pulp have high amorphous cellulose content. These fines, having a high surface area, restrict the free drainage of water and retain bound water within the pressed sheet but contribute little to the hydrogen bonding potential of the fibre slurry. The advantage of higher freeness, achieved by selective hydrolysis of excess fines through enzymes, can be used for enhancement of the drainage rate, leading to increased paper production. In this study, monocomponent cellulase treatment of recycled pulp for drainage improvement as a result of selective and controlled hydrolysis is investigated. The effectiveness of specific types of enzyme activity, endoglucanase or cellobiohydrolase, is studied. The increased solubilization of amorphous cellulose mediated by endoglucanase treatments improved pulp drainability by 11–25 %, along with providing better paper properties such as tensile index and smoothness.
Three‐dimensional brain atlas of pygmy squid, Idiosepius paradoxus, revealing the largest relative vertical lobe system volume among the cephalopods
Authors: Koizumi Motoki , Shigeno Shuichi , Mizunami Makoto , Tanaka Nobuaki K.
Published: December 2015

Cephalopods have the largest and most complex nervous system of all invertebrates, and the brain‐to‐body weight ratio exceeds those of most fish and reptiles. The brain is composed of lobe units, the functions of which have been studied through surgical manipulation and electrical stimulation. However, how information is processed in each lobe for the animal to make a behavioral decision has rarely been investigated. To perform such functional analyses, it is necessary to precisely describe how brain lobes are spatially organized and mutually interconnected as a whole. We thus made three‐dimensional digital brain atlases of both hatchling and juvenile pygmy squid, Idiosepius paradoxus. I. paradoxus is the smallest squid and has a brain small enough to scan as a whole region in the field‐of‐view of a low‐magnification laser scan microscope objective. Precise analyses of the confocal images of the brains revealed one newly identified lobe and also that the relative volume of the vertical lobe system, the higher association center, in the pygmy squid represents the largest portion compared with the cephalopod species reported previously. In addition, principal component analyses of relative volumes of lobe complexes revealed that the organization of I. paradoxus brain is comparable to those of Decapodiformes species commonly used to analyze complex behaviors such as Sepia officinalis and Sepioteuthis sepioidea. These results suggest that the pygmy squid can be a good model to investigate the brain functions of coleoids utilizing physiological methods. J. Comp. Neurol. 524:2142–2157, 2016. © 2016 Wiley Periodicals, Inc.
Different tonotopic regions of the lateral superior olive receive a similar combination of afferent inputs
Authors: Gómez‐Álvarez Marcelo , Saldaña Enrique
Published: December 2015

The mammalian lateral superior olive (LSO) codes disparities in the intensity of the sound that reaches the two ears by integrating ipsilateral excitation and contralateral inhibition, but it remains unclear what particular neuron types convey acoustic information to the nucleus. It is also uncertain whether the known conspicuous morphofunctional differences and gradients along the tonotopic axis of the LSO relate to qualitative and/or quantitative regional differences in its afferents. To clarify these issues, we made small, single injections of the neuroanatomical tracer biotinylated dextran amine (BDA) into different tonotopic regions of the LSO of albino rats and analyzed the neurons labeled retrogradely in brainstem auditory nuclei. We demonstrate that the LSO is innervated tonotopically by four brainstem neuron types: spherical bushy cells and planar multipolar neurons of the ipsilateral ventral cochlear nucleus, principal neurons of the ipsilateral medial nucleus of the trapezoid body, and small multipolar neurons of the contralateral ventral nucleus of the trapezoid body. Unexpectedly, the proportion of labeled neurons of each type was virtually identical in all cases, thus indicating that all tonotopic regions of the LSO receive a similar combination of inputs. Even more surprisingly, our data also suggest that the representation of frequencies in the LSO differs from that of the nuclei that innervate it: compared to the latter nuclei, the LSO seems to possess a relatively larger portion of its volume devoted to processing frequencies in the lower‐middle part of the spectrum, and a relative smaller portion devoted to higher frequencies. J. Comp. Neurol. 524:2230–2250, 2016. © 2015 Wiley Periodicals, Inc.
Alterations in the subcellular distribution of NADPH oxidase p47phox in hypothalamic paraventricular neurons following slow‐pressor angiotensin II hypertension in female mice with accelerated ovarian failure
Authors: Van Kempen Tracey A. , Narayan Ankita , Waters Elizabeth M. , Marques‐Lopes Jose , Iadecola Costantino , Glass Michael J. , Pickel Virginia M. , Milner Teresa A.
Published: December 2015

At younger ages, women have a lower risk for hypertension than men, but this sexual dimorphism declines with the onset of menopause. These differences are paralleled in rodents following “slow‐pressor” angiotensin II (AngII) administration: young male and aged female mice, but not young females, develop hypertension. There is also an established sexual dimorphism both in the cardiovascular response to the neurohypophyseal hormone arginine vasopressin (AVP) and in the expression of oxidative stress. We examined the relationship between AngII‐mediated hypertension and the cellular distribution of the superoxide generating NADPH oxidase (NOX) in AVP‐expressing hypothalamic paraventricular nucleus (PVN) neurons in “menopausal” female mice. Dual‐labeling immunoelectron microscopy was used to determine whether the subcellular distribution of the organizer/adapter NOX p47phox subunit is altered in PVN dendrites following AngII administered (14 days) during the “postmenopausal” stage of accelerated ovarian failure (AOF) in young female mice treated with 4‐vinylcyclohexene diepoxide. Slow‐pressor AngII elevated blood pressure in AOF females and induced a significant increase in near plasmalemmal p47phox and a decrease in cytoplasmic p47phox in PVN AVP dendrites. These changes are the opposite of those observed in AngII‐induced hypertensive male mice (Coleman et al. [2013] J. Neurosci. 33:4308‐4316) and may be ascribed in part to baseline differences between young females and males in the near plasmalemmal p47phox on AVP dendrites seen in the present study. These findings highlight fundamental differences in the neural substrates of oxidative stress in the PVN associated with AngII hypertension in postmenopausal females compared with males. J. Comp. Neurol. 524:2251–2265, 2016. © 2015 Wiley Periodicals, Inc.
Role of primary afferents in the developmental regulation of motor axon synapse numbers on Renshaw cells
Authors: Siembab Valerie C. , Gomez‐Perez Laura , Rotterman Travis M. , Shneider Neil A. , Alvarez Francisco J.
Published: December 2015

Motor function in mammalian species depends on the maturation of spinal circuits formed by a large variety of interneurons that regulate motoneuron firing and motor output. Interneuron activity is in turn modulated by the organization of their synaptic inputs, but the principles governing the development of specific synaptic architectures unique to each premotor interneuron are unknown. For example, Renshaw cells receive, at least in the neonate, convergent inputs from sensory afferents (likely Ia) and motor axons, raising the question of whether they interact during Renshaw cell development. In other well‐studied neurons, such as Purkinje cells, heterosynaptic competition between inputs from different sources shapes synaptic organization. To examine the possibility that sensory afferents modulate synaptic maturation on developing Renshaw cells, we used three animal models in which afferent inputs in the ventral horn are dramatically reduced (ER81−/− knockout), weakened (Egr3−/− knockout), or strengthened (mlcNT3+/− transgenic). We demonstrate that increasing the strength of sensory inputs on Renshaw cells prevents their deselection and reduces motor axon synaptic density, and, in contrast, absent or diminished sensory afferent inputs correlate with increased densities of motor axons synapses. No effects were observed on other glutamatergic inputs. We conclude that the early strength of Ia synapses influences their maintenance or weakening during later development and that heterosynaptic influences from sensory synapses during early development regulates the density and organization of motor inputs on mature Renshaw cells. J. Comp. Neurol. 524:1892–1919, 2016. © 2016 Wiley Periodicals, Inc.
Proton Transverse Relaxation as a Sensitive Probe for Structure Determination in Solid Proteins
Authors: Rovó Petra , Grohe Kristof , Giller Karin , Becker Stefan , Linser Rasmus
Published: December 2015

The front cover artwork is provided by the group of Dr. Rasmus Linser from the Max Planck Institute for Biophysical Chemistry. The image shows a protein chemically modified to contain a paramagnetic spin label. By quantifying the effects on proton spin states in solid‐state NMR, this effect is employed to shed light on the protein structure. Read the full text of the article at 10.1002/cphc.201500799
Utility of serum lipid ratios for predicting incident type 2 diabetes: the Isfahan Diabetes Prevention Study
Authors: Janghorbani Mohsen , Amini Masoud
Published: December 2015

Background

In this study, we evaluate the association between triglyceride to high‐density lipoprotein cholesterol (TG/HDL) ratio and total cholesterol (TC) to HDL (TC/HDL) ratio and the risks of type 2 diabetes (T2D) in an Iranian high‐risk population.

Methods

We analysed 7‐year follow‐up data (n = 1771) in non‐diabetic first‐degree relatives of consecutive patients with T2D 30–70 years old. The primary outcome was the diagnosis of T2D based on repeated oral glucose tolerance tests. We used Cox proportional hazard models to estimate hazard ratio for incident T2D across tertiles of TG/HDL and TC/HDL ratios and plotted a receiver operating characteristic (ROC) curve to assess discrimination.

Results

The highest tertile of TG/HDL and TC/HDL ratios compared with the lowest tertile was not associated with T2D in age‐ and gender‐adjusted models (HR 0.99, 95% CI: 0.88, 1.11 for TG/HDL ratio and 1.10, 95% CI: 0.97, 1.23 for TC/HDL ratio). Further adjustment for waist circumference or body mass index, fasting plasma glucose, and low‐density lipoprotein cholesterol did not appreciably alter the hazard ratio compared with the age‐ and gender‐adjusted model. The area under the ROC curve for TG/HDL ratio was 57.7% (95% CI: 54.0, 61.5) and for TC/HDL ratio was 55.1% (95% CI: 51.2, 59.0).

Conclusions

TG/HDL and TC/HDL ratios were not robust predictors of T2D in high‐risk individuals in Iran. Copyright © 2015 John Wiley & Sons, Ltd.