bluuebunny/crossref_metadata_2025 huggingface dataset:
Crustal and uppermost mantle structure beneath western Tibet using seismic traveltime tomography
Authors: Razi Ayda Shokoohi , Levin Vadim , Roecker Steven W. , Huang Guo‐chin Dino
Published: January 2014

We study the elastic wave speed structure of the crust and the uppermost mantle in western Tibet using P wave and S wave arrival times from regional earthquakes recorded by a temporary seismic network. We relocate the earthquakes, and subsequently invert travel time residuals for 3‐D distributions of wave speed. Resolution tests with a variety of input structures are used to verify the reliability of our results. The crust beneath western Tibet has low P wave speed (5.9–6.3 km/s) throughout its nearly 80 km thickness, with lower values in this range concentrated within the Lhasa block. Beneath the Himalaya wave speeds are higher. Southern and western limits of the slow material beneath the Tibetan Plateau correlate with the Karakoram fault, and dip beneath the plateau at ∼40° angle. We find no evidence of a subhorizontal low velocity zone in the crust. In the uppermost mantle, we find a long and narrow region of fast (up to 8.4 km/s) P wave speed extending from the Karakoram fault in NE direction, and crossing the Bangong‐Nujiang suture. In a north‐south cross section, the distribution of relatively fast P wave speed suggests a ramp‐flat geometry consistent with India underthrusting the Tibetan Plateau at least as far as 32.5°N. A plausible interpretation of the upper mantle fast feature is the formation of eclogite from the mafic lower‐crustal material of India after it is underthrust beneath Tibet. Notably, in western Tibet this process only takes place in a narrow region.
Spatial localization and ducting of EMIC waves: Van Allen Probes and ground‐based observations
Authors: Mann I. R. , Usanova M. E. , Murphy K. , Robertson M. T. , Milling D. K. , Kale A. , Kletzing C. , Wygant J. , Thaller S. , Raita T.
Published: January 2014

On 11 October 2012, during the recovery phase of a moderate geomagnetic storm, an extended interval (> 18 h) of continuous electromagnetic ion cyclotron (EMIC) waves was observed by Canadian Array for Real‐time Investigations of Magnetic Activity and Solar‐Terrestrial Environment Program induction coil magnetometers in North America. At around 14:15 UT, both Van Allen Probes B and A (65° magnetic longitude apart) in conjunction with the ground array observed very narrow (ΔL ~ 0.1–0.4) left‐hand polarized EMIC emission confined to regions of mass density gradients at the outer edge of the plasmasphere at L ~ 4. EMIC waves were seen with complex polarization patterns on the ground, in good agreement with model results from Woodroffe and Lysak (2012) and consistent with Earth's rotation sweeping magnetometer stations across multiple polarization reversals in the fields in the Earth‐ionosphere duct. The narrow L‐widths explain the relative rarity of space‐based EMIC occurrence, ground‐based measurements providing better estimates of global EMIC wave occurrence for input into radiation belt dynamical models.
North Pacific dissolved inorganic carbon variations related to the Pacific Decadal Oscillation
Authors: Yasunaka Sayaka , Nojiri Yukihiro , Nakaoka Shin‐ichiro , Ono Tsuneo , Mukai Hitoshi , Usui Norihisa
Published: January 2014

We elucidated multiyear variations of sea surface dissolved inorganic carbon (DIC) concentrations in the North Pacific from 2002 to 2008 by using monthly DIC maps derived from partial pressure CO2 observations. The Pacific Decadal Oscillation (PDO) was related to an east‐west seesaw pattern in the North Pacific DIC anomaly field. In the western North Pacific, DIC concentrations were relatively high from mid‐2002 to mid‐2005 and low after late 2007 compared with climatological values, and in the eastern North Pacific the opposite change was observed. Changes of the forcing factors associated with the PDO could explain the DIC east‐west seesaw pattern: horizontal advection, freshwater fluxes and vertical mixing in most regions, CO2 fluxes south of 40°N, and biological production in the subarctic.
An improved mass budget for the Greenland ice sheet
Authors: Enderlin Ellyn M. , Howat Ian M. , Jeong Seongsu , Noh Myoung‐Jong , van Angelen Jan H. , van den Broeke Michiel R.
Published: January 2014

Extensive ice thickness surveys by NASA's Operation IceBridge enable over a decade of ice discharge measurements at high precision for the majority of Greenland's marine‐terminating outlet glaciers, prompting a reassessment of the temporal and spatial distribution of glacier change. Annual measurements for 178 outlet glaciers reveal that, despite widespread acceleration, only 15 glaciers accounted for 77% of the 739 ± 29 Gt of ice lost due to acceleration since 2000 and four accounted for ~50%. Among the top sources of loss are several glaciers that have received little scientific attention. The relative contribution of ice discharge to total loss decreased from 58% before 2005 to 32% between 2009 and 2012. As such, 84% of the increase in mass loss after 2009 was due to increased surface runoff. These observations support recent model projections that surface mass balance, rather than ice dynamics, will dominate the ice sheet's contribution to 21st century sea level rise.
Storm time observations of plasmasphere erosion flux in the magnetosphere and ionosphere
Authors: Foster J. C. , Erickson P. J. , Coster A. J. , Thaller S. , Tao J. , Wygant J. R. , Bonnell J. W.
Published: January 2014

Plasmasphere erosion carries cold dense plasma of ionospheric origin in a storm‐enhanced density plume extending from dusk toward and through the noontime cusp and dayside magnetopause and back across polar latitudes in a polar tongue of ionization. We examine dusk sector (20 MLT) plasmasphere erosion during the 17 March 2013 storm (Dst ~ −130 nT) using simultaneous, magnetically aligned direct sunward ion flux observations at high altitude by Van Allen Probes RBSP‐A (at ~3.0 Re) and at ionospheric heights (~840 km) by DMSP F‐18. Plasma erosion occurs at both high and low altitudes where the subauroral polarization stream flow overlaps the outer plasmasphere. At ~20 UT, RBSP‐A observed ~1.2E12 m−2 s−1 erosion flux, while DMSP F‐18 observed ~2E13 m−2 s−1 sunward flux. We find close similarities at high and low altitudes between the erosion plume in both invariant latitude spatial extent and plasma characteristics.
Wind forced variability of the Antarctic Circumpolar Current south of Africa between 1993 and 2010
Authors: Domingues Ricardo , Goni Gustavo , Swart Sebastiaan , Dong Shenfu
Published: January 2014

The variability of the Antarctic Circumpolar Current (ACC) system is largely linked to the atmospheric forcing. The objective of this work is to assess the link between local wind forcing mechanisms and the variability of the upper‐ocean temperature and the dynamics of the different fronts in the ACC region south of South Africa. To accomplish this, in situ and satellite‐derived observations are used between 1993 and 2010. The main finding of this work is that meridional changes in the westerlies linked with the Southern Annular Mode (SAM) drive temperature anomalies in the Ekman layer and changes in the Subantarctic Front (SAF) and Antarctic Polar Front (APF) transports through Ekman dynamics. The development of easterly anomalies between 35°S and 45°S during positive SAM is linked to reduced (increased) SAF (APF) transports and a warmer mixed layer in the ACC. The link between the changes in the wind stress and the SAF and APF transport variations occurs through the development of Ekman pumping anomalies near the frontal boundaries, driving an opposite response on the SAF and APF transports. The observed wind‐driven changes in the frontal transports suggest small changes to the net ACC transport. In addition, observations indicate that the SAF and APF locations in this region are not linked to the local wind forcing, emphasizing the importance of other factors (e.g., baroclinic instabilities generated by bottom topography) to changes in the frontal location. Results obtained here highlight the importance of repeat XBT temperature sections and their combined analysis with other in situ and remote sensing observations.
Deterioration of perennial sea ice in the Beaufort Gyre from 2003 to 2012 and its impact on the oceanic freshwater cycle
Authors: Krishfield R. A. , Proshutinsky A. , Tateyama K. , Williams W. J. , Carmack E. C. , McLaughlin F. A. , Timmermans M.‐L.
Published: January 2014

Time series of ice draft from 2003 to 2012 from moored sonar data are used to investigate variability and describe the reduction of the perennial sea ice cover in the Beaufort Gyre (BG), culminating in the extreme minimum in 2012. Negative trends in median ice drafts and most ice fractions are observed, while open water and thinnest ice fractions (<0.3 m) have increased, attesting to the ablation or removal of the older sea ice from the BG over the 9 year period. Monthly anomalies indicate a shift occurred toward thinner ice after 2007, in which the thicker ice evident at the northern stations was reduced. Differences in the ice characteristics between all of the stations also diminished, so that the ice cover throughout the region became statistically homogenous. The moored data are used in a relationship with satellite radiometer data to estimate ice volume changes throughout the BG. Summer solid fresh water content decreased drastically in consecutive years from 730 km3 in 2006 to 570 km3 in 2007, and to 240 km3 in 2008. After a short rebound, solid fresh water fell below 220 km3 in 2012. Meanwhile, hydrographic data indicate that liquid fresh water in the BG in summer increased 5410 km3 from 2003 to 2010 and decreased at least 210 km3 by 2012. The reduction of both solid and liquid fresh water components indicates a net export of approximately 320 km3 of fresh water from the region occurred between 2010 and 2012, suggesting that the anticyclonic atmosphere‐ocean circulation has weakened.
Water level effects on breaking wave setup for Pacific Island fringing reefs
Authors: Becker J. M. , Merrifield M. A. , Ford M.
Published: January 2014

The effects of water level variations on breaking wave setup over fringing reefs are assessed using field measurements obtained at three study sites in the Republic of the Marshall Islands and the Mariana Islands in the western tropical Pacific Ocean. At each site, reef flat setup varies over the tidal range with weaker setup at high tide and stronger setup at low tide for a given incident wave height. The observed water level dependence is interpreted in the context of radiation stress gradients specified by an idealized point break model generalized for nonnormally incident waves. The tidally varying setup is due in part to depth‐limited wave heights on the reef flat, as anticipated from previous reef studies, but also to tidally dependent breaking on the reef face. The tidal dependence of the breaking is interpreted in the context of the point break model in terms of a tidally varying wave height to water depth ratio at breaking. Implications for predictions of wave‐driven setup at reef‐fringed island shorelines are discussed.
Air pollution over the Ganges basin and northwest Bay of Bengal in the early postmonsoon season based on NASA MERRAero data
Authors: Kishcha Pavel , da Silva Arlindo M. , Starobinets Boris , Alpert Pinhas
Published: January 2014

The MERRA Aerosol Reanalysis (MERRAero) has been recently developed at NASA's Global Modeling Assimilation Office. This reanalysis is based on a version of the Goddard Earth Observing System‐5 (GEOS‐5) model radiatively coupled with Goddard Chemistry, Aerosol, Radiation, and Transport aerosols, and it includes assimilation of bias‐corrected aerosol optical thickness (AOT) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on both Terra and Aqua satellites. In October over the period 2002–2009, MERRAero showed that AOT was lower over the east of the Ganges basin than over the northwest of the Ganges basin: this was despite the fact that the east of the Ganges basin should have produced higher anthropogenic aerosol emissions because of higher population density, increased industrial output, and transportation. This is evidence that higher aerosol emissions do not always correspond to higher AOT over the areas where the effects of meteorological factors on AOT dominate those of aerosol emissions. MODIS AOT assimilation was essential for correcting modeled AOT mainly over the northwest of the Ganges basin, where AOT increments were maximal. Over the east of the Ganges basin and northwest Bay of Bengal (BoB), AOT increments were low and MODIS AOT assimilation did not contribute significantly to modeled AOT. Our analysis showed that increasing AOT trends over northwest BoB (exceeding those over the east of the Ganges basin) were reproduced by GEOS‐5, not because of MODIS AOT assimilation but mainly because of the model capability of reproducing meteorological factors contributing to AOT trends. Moreover, vertically integrated aerosol mass flux was sensitive to wind convergence causing aerosol accumulation over northwest BoB.
The contribution of anthropogenic SO2 emissions to the Asian tropopause aerosol layer
Authors: Neely R. R. , Yu P. , Rosenlof K. H. , Toon O. B. , Daniel J. S. , Solomon S. , Miller H. L.
Published: January 2014

Recent observations reveal a seasonally occurring layer of aerosol located from 0° to 100°E, 20° to 45°N and extending vertically from about 13 km to 18 km; this has been termed the Asian tropopause aerosol layer (ATAL), and its existence is closely associated with the Asian summer monsoon circulation. Observational studies argue that the ATAL is a recent phenomenon, as the layer is not observed in the satellite record prior to 1998. This suggests that the ATAL may be of anthropogenic origin associated with a shift in the dominant regional emission of sulfur dioxide (SO2) to China and India in the late 1990s. Here we test the hypothesis that SO2emitted from Asia led to the formation of the ATAL using an aerosol microphysical model coupled to a global chemistry climate model. This is the first modeling study to specifically examine the ATAL and its possible origin. From our results, we conclude that the ATAL is most likely due to anthropogenic emissions, but its source cannot solely be attributed to emissions from Asia. Specifically, the results indicate that Chinese and Indian emissions contribute ∼30% of the sulfate aerosol extinction in the ATAL during volcanically quiescent periods. We also show that even small volcanic eruptions preclude our ability to make any conclusions about the existence of the ATAL before 1998 with observations alone.
SPARE‐ICE: Synergistic ice water path from passive operational sensors
Authors: Holl G. , Eliasson S. , Mendrok J. , Buehler S. A.
Published: January 2014

This article presents SPARE‐ICE, the Synergistic Passive Atmospheric Retrieval Experiment‐ICE. SPARE‐ICE is the first Ice Water Path (IWP) product combining infrared and microwave radiances. By using only passive operational sensors, the SPARE‐ICE retrieval can be used to process data from at least the NOAA 15 to 19 and MetOp satellites, obtaining time series from 1998 onward. The retrieval is developed using collocations between passive operational sensors (solar, terrestrial infrared, microwave), the CloudSat radar, and the CALIPSO lidar. The collocations form a retrieval database matching measurements from passive sensors against the existing active combined radar‐lidar product 2C‐ICE. With this retrieval database, we train a pair of artificial neural networks to detect clouds and retrieve IWP. When considering solar, terrestrial infrared, and microwave‐based measurements, we show that any combination of two techniques performs better than either single‐technique retrieval. We choose not to include solar reflectances in SPARE‐ICE, because the improvement is small, and so that SPARE‐ICE can be retrieved both daytime and nighttime. The median fractional error between SPARE‐ICE and 2C‐ICE is around a factor 2, a figure similar to the random error between 2C‐ICE ice water content (IWC) and in situ measurements. A comparison of SPARE‐ICE with Moderate Resolution Imaging Spectroradiometer (MODIS), Pathfinder Atmospheric Extended (PATMOS‐X), and Microwave Surface and Precipitation Products System (MSPPS) indicates that SPARE‐ICE appears to perform well even in difficult conditions. SPARE‐ICE is available for public use.
Low cloud reduction in a greenhouse‐warmed climate: Results from Lagrangian LES of a subtropical marine cloudiness transition
Authors: Bretherton Christopher S. , Blossey Peter N.
Published: January 2014

Lagrangian large‐eddy simulations of a composite stratocumulus to cumulus transition case over the subtropical northeast Pacific Ocean are subject to perturbed forcings that isolate the cloud response to CO2, to overall tropical warming, and to increased inversion stability over the subtropical subsidence regions. These simulations show that a tropical surface warming of 4 K induces substantial stratocumulus thinning via a thermodynamic mechanism: increased cloud layer humidity flux in a warmer climate induces an entrainment liquid‐flux adjustment that dries the stratocumulus cloud layer, whether well mixed or cumulus coupled. A radiative mechanism amplifies this response: increased emissivity of the free troposphere due to increased CO2 and water vapor reduces radiative driving of turbulence in a stratocumulus‐capped boundary layer; a thinner stratocumulus layer accompanies less turbulence. In combination, a 4 K warming and CO2 quadrupling greatly reduce low cloud and weaken the simulated shortwave cloud radiative effect by over 50%. Large increases in inversion stability in the stratocumulus regions could counter much of this cloudiness reduction.
Observer design for nonlinear parameter‐varying systems: Application to diesel engines
Authors: Boulkroune B. , Aitouche A. , Cocquempot V.
Published: January 2014

This paper deals with the problem of designing a nonlinear observer for diesel engines. The goal is to estimate the masses entering the cylinders and the inlet and exhaust pressures. To achieve this, the considered model subject to disturbances contains linear parameter‐varying part and nonlinear part having a large Lipschitz constant. The H ∞  criterion is used to reject the disturbances. Besides, the modified mean value theorem is applied to express the nonlinear error dynamics as a convex combination of known matrices with time‐varying coefficients. The sufficient conditions are derived and given in terms of linear matrix inequality. The advantage of the proposed method is that it can be applied to a wider class of nonlinear systems, particulary our case: diesel engines. The proposed approach is tested and evaluated using an advanced diesel engine professional simulator AMEsim (LMS International, Leuven, Belgium). Copyright © 2014 John Wiley & Sons, Ltd.
Digital Doppelgängers: Future Scanscapes
Authors: Shaw Matthew , Trossell William
Published: January 2014

Over the course of the last two years, ScanLAB Projects have explored various fragments of the natural and man‐made world through the eyes of their forensic measuring machine. From surface mapping of Arctic ice floes in the Fram Strait (gateway to the Arctic) to the documentation of torture and detention sites in the Balkans, via the accidental editing of a Richard Long sculpture, to purposeful acts of detail theft from Foster and Wren. Here, Matthew Shaw and William Trossell discuss the capture, analysis and refabrication of their digital architectural doppelgängers.
What We Want Is in That Room
Authors: Gaynor Ilona , Singleton Benedict
Published: January 2014

Ilona Gaynor and Benedict Singleton, founding partners of design and research studio The Department of No, look beyond the specific technological possibilities of acute accuracy and explore the principle of zero tolerance as an aesthetic of precision. How is such an aesthetic at work when an architectural strategy places a heightened emphasis on the exact placement of objects in space and time? Could the precision in which a single spatial intervention is pursued have more fundamental and far‐reaching consequences than we ever imagined?
Tripping the Flight Fantastic: Slipstream, Terminal 2, Heathrow Airport
Authors: Parker Ralph , Lucas Tim
Published: January 2014

Ralph Parker and Tim Lucas of Price & Myers Geometrics explain the complex architectural and engineering challenges of turning a simple idea – solidifying the motion of a joyfully cartwheeling aircraft – into a vast kit‐of‐parts jigsaw puzzle for Richard Wilson's new sculpture at Heathrow.
Gehry Partners' Fondation Louis Vuitton: Crowdsourcing Embedded Intelligence
Authors: Nolte Tobias , Witt Andrew
Published: January 2014

The complexity of the mass‐customised forms of Gehry Partners' new art museum in Paris, the Fondation Louis Vuitton pour la création, has taken high‐definition simulation techniques and embedded intelligence to a new level. Tobias Nolte and Andrew Witt of Gehry Technologies describe how the realisation of the Fondation required the development of a 3D concurrent design system that could synchronise hundreds of participants. This self‐optimisation system has enabled both ‘intricate collaboration and unprecedented engineering’. The benefits have been far reaching, ranging from the detailing of tolerances to material constraints.
Impossible Objects
Authors: Kruysman Brandon , Proto Jonathan
Published: January 2014

Jonathan Proto and Brandon Kruysman of Kruysman‐Proto, both design technologists at San Francisco‐based Bot & Dolly, a design and engineering studio that specialises in automation, robotics and filmmaking, describe their radical approach to architectural representation. They explain how by combining cinematic techniques and advanced robotic manufacturing they have been able to explore a new model for making that shifts the role of robotics in fabrication away from a process largely focused on geometric rationalisation into the sphere of visualisation and ideas creation.
To the Micron: A New Architecture Through High‐Resolution Multi‐Scalar Design and Manufacturing
Authors: Beckett Richard , Babu Sarat
Published: January 2014

Rapidly shrinking tolerances and increasing fidelity of emerging additive layer systems are beginning to afford a new opportunity: the ability to design below the macroscopic scale. This is resulting in the engineering of hybrid materials in which every element of their properties can be prescribed at the point of design conception. Richard Beckett of the Digital Manufacturing Centre (DMC), London, and the Bartlett School of Architecture, UCL, and Sarat Babu of Betatype explore a potential new architecture that encompasses a scalar hierarchy of matter, enabling design to take place concurrently at scales ranging from the micrometre to the metre.
4D Printing: Multi‐Material Shape Change
Authors: Tibbits Skylar
Published: January 2014

How might 4D printing overcome the obstacles that are hampering the rolling out and scaling up of 3D printing? Skylar Tibbits, Director of the Self‐Assembly Lab at the Massachusetts Institute of Technology (MIT), describes how the Lab has partnered up with Stratasys Ltd, an industry leader in the development of 4D Printing, and is making the development of self‐assembly programmable materials and adaptive technologies for industrial application in building design and construction its focus.
Soft Tolerance: An Approach for Additive Construction on Site
Authors: Malé‐Alemany Marta , Portell Jordi
Published: January 2014

Does high precision have to result in highly defined slick forms? Marta Malé‐Alemany and Jordi Portell of the FABbots research studio describe their unique approach that relies on the customisation of existing mechanical devices and the use of locally available materials. Though exacting in their execution of machine code, they maintain a delight in the natural characteristics of materials that are shaped with a ‘soft tolerance’.
Why We Need Architecture of Tolerance
Authors: Kolarevic Branko
Published: January 2014

Professor and Chair in Integrated Design at the University of Calgary Faculty of Environmental Design, Branko Kolarevic has established an international reputation as an author and commentator on digital design and manufacturing in architecture. Here he questions the importance of high‐definition tolerance in construction itself. As an industry that operates at far greater sizes and scales than other manufacturing bases, has the ‘messy world of building’ not always had to allow for a reasonable tolerance of errors? Should high‐definition processes, which negate or negotiate zero tolerance, really be for architects and construction professionals the Holy Grail that they first appear?
Electronic Structure of Fullerene Heterodimer in Bulk‐Heterojunction Blends
Authors: Poluektov Oleg G. , Niklas Jens , Mardis Kristy L. , Beaupré Serge , Leclerc Mario , Villegas Carmen , Erten‐Ela Sule , Delgado Juan L. , Martín Nazario , Sperlich Andreas , Dyakonov Vladimir
Published: January 2014

To increase performance of organic solar cells, the optimization of the electron‐accepting fullerenes has received less attention. Here, an electronic structure study of a novel covalently linked C60‐C70‐heterodimer in blend with the polymer PCDTBT (poly[9‐(1‐octylnonyl)‐9H‐carbazole‐2,7‐diyl]‐2,5‐thiophenediyl‐2,1,3‐benzothiadiazole‐4,7‐diyl‐2,5‐thiophenediyl) is presented. Upon optical excitation of polymer:heterodimer solid films, the unpaired electron is shared between both C60 and C70 cages. In contrast, in the solution the electron is localized on one half of the dimer. Electronic structure calculations reveal that for the C60‐C70‐heterodimer two nearly isoenergetic minima exist, essentially the cis and trans conformers, which are separated by a thermodynamically accessible rotational barrier. In the cis conformation, the edge‐to‐edge distance between the two cages is ca. 4 Å and an unpaired electron is shared between two dimer halves, while in the trans conformation the separation between the fullerene cages is larger and favors electron localization on one half of the heterodimer. By comparison with the experimental data, it is concluded that the cis conformation is preferable in films, and the trans conformation in solution. Modification of the linking molecular bridge opens the possibility to influence the electronic properties of fullerene dimers, which in turn may have an impact on the charge carrier generation efficiency in solar cells.
Failure Modes and Fast Repair Procedures in High Voltage Organic Solar Cell Installations
Authors: Hösel Markus , Søndergaard Roar R. , Jørgensen Mikkel , Krebs Frederik C.
Published: January 2014

Steadily increasing efficiencies of organic solar cells are frequently published but the practical demonstration of actual large‐scale installations with high power output has been very limited. Here, the real‐world challenges and opportunities of organic solar cells fabricated on thin plastic foil and mounted in solar cell arrays of more than 1 kW are shown. In this configuration defects in form of burns that have never been reported before are observed. The reason can be seen in the combination of high power production, water ingress, and the use of thin plastic foil as the substrate. Environmental impact such as lightning was also observed to cause randomly distributed burn holes that initiate self‐sustained damaging under illumination. The large solar cell modules each with more than 220 Wpeak are based only on serially connected cells and need no time‐consuming manual wiring of single cells. Although burns that locally destroy the modules are observed the efficiency is not much affected. Simple repair procedures developed throughout the lifetime study enable the cut and replace of small pieces of the module. A complete replacement as it is carried out for malfunctioning conventional Si‐based PV modules is not necessary. This enables cost‐effective maintenance over the lifetime of the organic solar cells.
The carcinogenic effects of aspartame: The urgent need for regulatory re‐evaluation
Authors: Soffritti Morando , Padovani Michela , Tibaldi Eva , Falcioni Laura , Manservisi Fabiana , Belpoggi Fiorella
Published: January 2014

Aspartame (APM) is an artificial sweetener used since the 1980s, now present in >6,000 products, including over 500 pharmaceuticals. Since its discovery in 1965, and its first approval by the US Food and Drugs Administration (FDA) in 1981, the safety of APM, and in particular its carcinogenicity potential, has been controversial.

The present commentary reviews the adequacy of the design and conduct of carcinogenicity bioassays on rodents submitted by G.D. Searle, in the 1970s, to the FDA for market approval. We also review how experimental and epidemiological data on the carcinogenic risks of APM, that became available in 2005 motivated the European Commission (EC) to call the European Food and Safety Authority (EFSA) for urgent re‐examination of the available scientific documentation (including the Searle studies). The EC has further requested that, if the results of the evaluation should suggest carcinogenicity, major changes must be made to the current APM specific regulations.

Taken together, the studies performed by G.D. Searle in the 1970s and other chronic bioassays do not provide adequate scientific support for APM safety. In contrast, recent results of life‐span carcinogenicity bioassays on rats and mice published in peer‐reviewed journals, and a prospective epidemiological study, provide consistent evidence of APM's carcinogenic potential. On the basis of the evidence of the potential carcinogenic effects of APM herein reported, a re‐evaluation of the current position of international regulatory agencies must be considered an urgent matter of public health. Am. J. Ind. Med. 57:383–397, 2014. © 2014 Wiley Periodicals, Inc.
Musculoskeletal and neurological injuries associated with work organization among immigrant latino women manual workers in North Carolina
Authors: Arcury Thomas A. , Cartwright Michael S. , Chen Haiying , Rosenbaum Daryl A. , Walker Francis O. , Mora Dana C. , Quandt Sara A.
Published: January 2014

Background

This analysis examines the associations of work organization attributes among Latino women in manual occupations with musculoskeletal and neurological injuries.

Methods

Participants included 234 women in western North Carolina. Outcome measures included epicondylitis, rotator cuff syndrome, back pain, and carpal tunnel syndrome. Independent measures included indicators of job demand, job control, and job support, as well as personal characteristics.

Results

Latina workers commonly experienced epicondylitis, rotator cuff syndrome, back pain, and CTS. Awkward posture and decision latitude were associated with epicondylitis. Rotator cuff syndrome was associated with awkward posture and psychological demand. Awkward posture and psychological demand, and decreased skill variety and job control were related to CTS.

Conclusions

Work organization factors are potentially important for musculoskeletal and neurological injury among vulnerable workers. Research is required to understand the associations of work and health outcomes of these women. Policy initiatives need to consider how work organization affects health. Am. J. Ind. Med. 57:468–475, 2014. © 2014 Wiley Periodicals, Inc.
Kinetic Resolution of Diols via Etherification Catalyzed by a Chiral Phosphoric Acid: Concise Synthesis of (+)‐Sacidumlignan D
Authors: Xie Changmin , Bai Donghu , Huang Sha‐Hua , Jia Xueshun , Hong Ran
Published: January 2014

A kinetic resolution of a diol via etherification catalyzed by a chiral phosphoric acid was developed and applied in the concise total synthesis of (+)‐sacidumlignan D, the antipode of natural sacidumlignan D. A zinc‐mediated crotylation of a diarylketone and subsequent lactonization quickly established the carbon framework of this class of tetrahydrofuran lignans.
Lanthanide‐Doped LiLuF4 Upconversion Nanoprobes for the Detection of Disease Biomarkers
Authors: Huang Ping , Zheng Wei , Zhou Shanyong , Tu Datao , Chen Zhuo , Zhu Haomiao , Li Renfu , Ma En , Huang Mingdong , Chen Xueyuan
Published: January 2014

Lanthanide‐doped upconversion nanoparticles (UCNPs) have shown great promise in bioapplications. Exploring new host materials to realize efficient upconversion luminescence (UCL) output is a goal of general concern. Herein, we develop a unique strategy for the synthesis of novel LiLuF4:Ln3+ core/shell UCNPs with typically high absolute upconversion quantum yields of 5.0 % and 7.6 % for Er3+ and Tm3+, respectively. Based on our customized UCL biodetection system, we demonstrate for the first time the application of LiLuF4:Ln3+ core/shell UCNPs as sensitive UCL bioprobes for the detection of an important disease marker β subunit of human chorionic gonadotropin (β‐hCG) with a detection limit of 3.8 ng mL−1, which is comparable to the β‐hCG level in the serum of normal humans. Furthermore, we use these UCNPs in proof‐of‐concept computed tomography imaging and UCL imaging of cancer cells, thus revealing the great potential of LiLuF4:Ln3+ UCNPs as efficient nano‐bioprobes in disease diagnosis.
Effect of triarylphosphane ligands on the rhodium‐catalyzed hydrosilylation of alkene
Authors: Xue Mei , Li Jiayun , Peng Jiajian , Bai Ying , Zhang Guodong , Xiao Wenjun , Lai Guoqiao
Published: January 2014

A series of triarylphosphanes (1a, 2a, 3a, 4a, 5a, 6a, 7a, 8a, 9a, 10a, 11a) have been synthesized. An X‐ray crystal structure analysis of (2‐bromophenyl)diphenylphosphane (1a) unambiguously confirmed the constitution of the functionalized phosphane. The hydrosilylation reaction of styrene with triethoxysilane catalyzed with RhCl3/triarylphosphane was studied. In comparison with the classic Wilkinson's catalyst, rhodium complexes with functionalized triarylphosphane ligands are characterized by a very high catalytic effectiveness for the hydrosilylation of alkene. Among these catalysts tested, RhCl3/diphenyl(2‐(trimethylsilyl)phenyl)phosphane (8a) exhibited excellent catalytic properties. Using this silicon‐containing phosphane ligand for the rhodium‐catalyzed hydrosilylation of styrene, both higher conversion of alkene and higher β‐adduct selectivity were obtained than with Wilkinson's catalyst. Copyright © 2014 John Wiley & Sons, Ltd.
Distribution, structure and function of Nordic eelgrass (Zostera marina) ecosystems: implications for coastal management and conservation
Authors: Boström Christoffer , Baden Susanne , Bockelmann Anna‐Christina , Dromph Karsten , Fredriksen Stein , Gustafsson Camilla , Krause‐Jensen Dorte , Möller Tiia , Nielsen Søren Laurentius , Olesen Birgit , Olsen Jeanine , Pihl Leif , Rinde Eli
Published: January 2014

This paper focuses on the marine foundation eelgrass species, Zostera marina, along a gradient from the northern Baltic Sea to the north‐east Atlantic. This vast region supports a minimum of 1480 km2 eelgrass (maximum >2100 km2), which corresponds to more than four times the previously quantified area of eelgrass in Western Europe.

Eelgrass meadows in the low salinity Baltic Sea support the highest diversity (4–6 spp.) of angiosperms overall, but eelgrass productivity is low (<2 g dw m‐2 d‐1) and meadows are isolated and genetically impoverished. Higher salinity areas support monospecific meadows, with higher productivity (3–10 g dw m‐2 d‐1) and greater genetic connectivity. The salinity gradient further imposes functional differences in biodiversity and food webs, in particular a decline in number, but increase in biomass of mesograzers in the Baltic.

Significant declines in eelgrass depth limits and areal cover are documented, particularly in regions experiencing high human pressure. The failure of eelgrass to re‐establish itself in affected areas, despite nutrient reductions and improved water quality, signals complex recovery trajectories and calls for much greater conservation effort to protect existing meadows.

The knowledge base for Nordic eelgrass meadows is broad and sufficient to establish monitoring objectives across nine national borders. Nevertheless, ensuring awareness of their vulnerability remains challenging. Given the areal extent of Nordic eelgrass systems and the ecosystem services they provide, it is crucial to further develop incentives for protecting them.

© 2014 The Authors. Aquatic Conservation: Marine and Freshwater Ecosystems published by John Wiley & Sons, Ltd.
A Synthetic Approach for Constructing the 3/6/6/5‐Fused Tetracyclic Skeleton of Tenuipesine A
Authors: Tian Jin‐Miao , Zhao Xiong , Tu Yong‐Qiang , Gong Wei , Zhang Fu‐Min , Zhang Shu‐Yu , Wang Shao‐Hua
Published: January 2014

An efficient approach toward the 3/6/6/5‐fused tetracyclic skeleton of tenuipesine A has been accomplished. The strategy featured 1) a tandem Mitsunobu and 3,3‐rearrangement reaction yielding the key intermediate 7 with two adjacent all‐carbon quaternary centers with high d.r.; and 2) a tandem DBDMH‐mediated semipinacol rearrangement via a 1,2‐oxygen migration of an allylic hemiketal to construct the highly substituted tetrahydropyran ring.
THE DEVELOPMENT OF FALSE‐POSITIVE OUTCOMES DURING FUNCTIONAL ANALYSES OF PROBLEM BEHAVIOR
Authors: Jessel Joshua , Hausman Nicole L. , Schmidt Jonathan D. , Darnell Lily C. , Kahng SungWoo
Published: January 2014

False‐positive outcomes of functional analyses exist when exposure to the consequences in a condition strengthens a relation that did not previously exist. Two functional analyses (aggression and spitting) were conducted with a child with an intellectual disability. High rates of problem behavior occurred immediately in the attention condition of the functional analysis across response topographies, suggesting a clear functional response class. However, rates of aggression and spitting increased in the demand condition, following the initial block of sessions, indicating the possible creation of a novel contingent relation for spitting. Copyright © 2014 John Wiley & Sons, Ltd.
Trends in performance indicators of neuroimaging anatomy research publications: A bibliometric study of major neuroradiology journal output over four decades based on web of science database
Authors: Wing Louise , Massoud Tarik F.
Published: January 2014

Quantitative, qualitative, and innovative application of bibliometric research performance indicators to anatomy and radiology research and education can enhance cross‐fertilization between the two disciplines. We aim to use these indicators to identify long‐term trends in dissemination of publications in neuroimaging anatomy (including both productivity and citation rates), which has subjectively waned in prestige during recent years. We examined publications over the last 40 years in two neuroradiological journals, AJNR and Neuroradiology, and selected and categorized all neuroimaging anatomy research articles according to theme and type. We studied trends in their citation activity over time, and mathematically analyzed these trends for 1977, 1987, and 1997 publications. We created a novel metric, “citation half‐life at 10 years postpublication” (CHL‐10), and used this to examine trends in the skew of citation numbers for anatomy articles each year. We identified 367 anatomy articles amongst a total of 18,110 in these journals: 74.2% were original articles, with study of normal anatomy being the commonest theme (46.7%). We recorded a mean of 18.03 citations for each anatomy article, 35% higher than for general neuroradiology articles. Graphs summarizing the rise (upslope) in citation rates after publication revealed similar trends spanning two decades. CHL‐10 trends demonstrated that more recently published anatomy articles were likely to take longer to reach peak citation rate. Bibliometric analysis suggests that anatomical research in neuroradiology is not languishing. This novel analytical approach can be applied to other aspects of neuroimaging research, and within other subspecialties in radiology and anatomy, and also to foster anatomical education. Clin. Anat. 28:16–26, 2015. © 2014 Wiley Periodicals, Inc.
Sternalis muscle, what every anatomist and clinician should know
Authors: Snosek Michael , Tubbs R. Shane , Loukas Marios
Published: January 2014

The sternalis muscle is a well documented but rare muscular variation of the anterior thoracic wall. It lies between the superficial fascia and the pectoral fascia and is found in about 8% of the population. It presents in several morphological variants both unilaterally and bilaterally and has no apparent physiological function. There is still much disagreement about its nerve supply and embryological origin. With the advent of medical imaging and thoracic surgery the clinical importance of this muscle has been re‐emphasized. It has been implicated in misdiagnosis of breast masses on routine mammograms owing to its parasternal location and relative unfamiliarity among radiologists. When undetected before any thoracic surgery, it has the potential to interfere with and prolong such procedures. When present and detected preoperatively it can be used as a muscular flap in reconstructive surgeries of the breast and neck. This article will present the sternalis muscle with special emphasis on its morphology, homology, and clinical significance. Clin. Anat. 27:866–884, 2014. © 2014 Wiley Periodicals, Inc.
Lipochitin Oligosaccharides Immobilized through Oximes in Glycan Microarrays Bind LysM Proteins
Authors: Maolanon Nicolai N. , Blaise Mickael , Sørensen Kasper K. , Thygesen Mikkel B. , Cló Emiliano , Sullivan John T. , Ronson Clive W. , Stougaard Jens , Blixt Ola , Jensen Knud J.
Published: January 2014

Glycan microarrays have emerged as novel tools to study carbohydrate–protein interactions. Here we describe the preparation of a covalent microarray with lipochitin oligosaccharides and its use in studying proteins containing LysM domains. The glycan microarray was assembled from glycoconjugates that were synthesized by using recently developed bifunctional chemoselective aminooxy reagents without the need for transient carbohydrate protecting groups. We describe for the first time the preparation of a covalent microarray with lipochitin oligosaccharides and its use for studying proteins containing LysM domains. Lipochitin oligosaccharides (also referred to as Nod factors) were isolated from bacterial strains or chemoenzymatically synthesized. The glycan microarray also included peptidoglycan‐related compounds, as well as chitin oligosaccharides of different lengths. In total, 30 ligands were treated with the aminooxy linker molecule. The identity of the glycoconjugates was verified by mass spectrometry, and they were then immobilized on the array. The presence of the glycoconjugates on the array surface was confirmed by use of lectins and human sera (IgG binding). The functionality of our array was tested with a bacterial LysM domain‐containing protein, autolysin p60, which is known to act on the bacterial cell wall peptidoglycan. P60 showed specific binding to Nod factors and to chitin oligosaccharides. Increasing affinity was observed with increasing chitin oligomer length.
Solid‐Phase Synthesis and Biological Evaluation of N‐Dipeptido L‐Homoserine Lactones as Quorum Sensing Activators
Authors: Hansen Mette R. , Le Quement Sebastian T. , Jakobsen Tim H. , Skovstrup Søren , Taboureau Olivier , Tolker‐Nielsen Tim , Givskov Michael , Nielsen Thomas E.
Published: January 2014

Bacteria use small signaling molecules to communicate in a process termed “quorum sensing” (QS), which enables the coordination of survival strategies, such as production of virulence factors and biofilm formation. In Gram‐negative bacteria, these signaling molecules are a series of N‐acylated L‐homoserine lactones. With the goal of identifying non‐native compounds capable of modulating bacterial QS, a virtual library of N‐dipeptido L‐homoserine lactones was screened in silico with two different crystal structures of LasR. The 30 most promising hits were synthesized on HMBA‐functionalized PEGA resin and released through an efficient acid‐mediated cyclative release mechanism. Subsequent screening for modulation of QS in Pseudomonas aeruginosa and E. coli identified six moderately strong activators. A follow‐up library designed from the preliminary derived structure–activity relationships was synthesized and evaluated for their ability to activate the QS system in this bacterium. This resulted in the identification of another six QS activators (two with low micromolar activity) thus illuminating structural features required for QS modulation.
On One Leg: Trehalose Monoesters Activate Macrophages in a Mincle‐Dependent Manner
Authors: Stocker Bridget L. , Khan Ashna A. , Chee Stephanie H. , Kamena Faustin , Timmer Mattie S. M.
Published: January 2014

The C22 and C26 trehalose monoesters, each containing a single acyl chain, were synthesised in good overall yields and found to activate macrophages in a Mincle‐dependent manner. The activities of the monoesters paralleled those of their diester counterparts, and both mono‐ and diesters could activate the immune response in the absence of priming. This is the first time that trehalose monoesters have been found to activate macrophages, and these studies thus provide an important framework for the rational design of other Mincle agonists.
Impact of CMS coverage decision on access to transcatheter aortic valve replacement
Authors: O'Neill Brian P. , O'Neill William W. , Williams Donald , Cohen Mauricio G. , Heldman Alan W. , Macon Conrad , Martinez Claudia A. , Alfonso Carlos E. , Clark Pedro Martinez , Velasquez Omaida , Seo David , Clermont Pascal Goldschmidt , Moscucci Mauro
Published: January 2014

Objectives

To assess the impact of the Centers for Medicare and Medicaid Services (CMS) national coverage determination (NCD) on access for patients with aortic stenosis (AS) with transcatheter aortic valve replacement (TAVR) in a tertiary care center.

Background

TAVR has given hope to patients with AS who are deemed inoperable. The effects of the NCD on access to patients with AS has not been evaluated.

Materials and Methods

A total of 94 inoperable AS patients were evaluated and treated from December 2011 through June of 2012 with TAVR. Patients who underwent transfemoral (TF) vs. non‐TF access were compared. The CMS NCD was released on May 1, 2012 and on July 1, 2012, the nontransfemoral access program was put on hold due to lack of reimbursement.

Results

Patients in the TF (n = 33) and non‐TF access (n = 61) groups were similar in age (85.2 ± 6.3 vs. 84.8 ± 6.6 P = 0.74) and STS mortality (9.38 ± 5.33 vs. 7.91 ± 3.69, P = 0.074). The iliofemoral arteries were larger diameter in the TF group (7.72 ± 1.49 vs. 6.21 ± 1.78, P < 0.001) and males (7.39 ± 1.81 vs. 6.1 ± 1.61 P < 0.001). More women underwent valve implantation via non‐TF access (73 vs. 23%, P = 0.03). After the NCD, 21 patients who previously qualified for non‐TF TAVR would not be reimbursed by CMS. Four died soon after.

Conclusions

After the NCD, the proportion of inoperable patients with severe AS that can be treated with TAVR was greatly reduced due the lack of reimbursement for TAVR via non‐TF access. This effect is particularly pronounced in women. © 2014 Wiley Periodicals, Inc.