bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of submesoscale processes on dynamics of phytoplankton filaments
Authors: Shulman Igor , Penta Bradley , Richman James , Jacobs Gregg , Anderson Stephanie , Sakalaukus Peter
Published: February 2015

In Monterey Bay, CA, during northwesterly, upwelling favorable winds, the development of a southward flowing cold jet along the entrance to the Bay is often observed. This dense cold jet separates warm waters of the anticyclonic circulation offshore from the water masses inside the Bay. Interactions between the cold jet and the offshore anticyclonic circulation generate ageostrophic secondary circulation (ASC) cells due to submesoscale processes as, for example, flow interaction with the development of surface frontogenesis and nonlinear Ekman pumping. Based on observations and modeling studies, we evaluate the impact of these submesoscale processes on the formation of chlorophyll a filaments during late spring‐earlier summer, and late summer time frames. We show that during the late summer time frame, ASC leads to the development of filaments with high values of chlorophyll a concentration along the edge of the cold jet–in contrast to the earlier summer time, when the ASC mixes phytoplankton much deeper to the area below of the euphotic depth, and chlorophyll a filaments are 3–4 times weaker.
On the origin and propagation of Denmark Strait overflow water anomalies in the Irminger Basin
Authors: Jochumsen Kerstin , Köllner Manuela , Quadfasel Detlef , Dye Stephen , Rudels Bert , Valdimarsson Heðinn
Published: February 2015

Denmark Strait Overflow Water (DSOW) supplies the densest contribution to North Atlantic Deep Water and is monitored at several locations in the subpolar North Atlantic. Hydrographic (temperature and salinity) and velocity time series from three multiple‐mooring arrays at the Denmark Strait sill, at 180 km downstream (south of Dohrn Bank) and at a further 320 km downstream on the east Greenland continental slope near Tasiilaq (formerly Angmagssalik), were analyzed to quantify the variability and track anomalies in DSOW in the period 2007–2012. No long‐term trends were detected in the time series, while variability on time scales from interannual to weekly was present at all moorings. The hydrographic time series from different moorings within each mooring array showed coherent signals, while the velocity fluctuations were only weakly correlated. Lagged correlations of anomalies between the arrays revealed a propagation from the sill of Denmark Strait to the Angmagssalik array in potential temperature with an average propagation time of 13 days, while the correlations in salinity were low. Entrainment of warm and saline Atlantic Water and fresher water from the East Greenland Current (via the East Greenland Spill Jet) can explain the whole range of hydrographic changes in the DSOW measured downstream of the sill. Changes in the entrained water masses and in the mixing ratio can thus strongly influence the salinity variability of DSOW. Fresh anomalies found in downstream measurements of DSOW within the Deep Western Boundary Current can therefore not be attributed to Arctic climate variability in a straightforward way.
Large variability of the Kuroshio at 23.75°N east of Taiwan
Authors: Jan Sen , Yang Yiing Jang , Wang Joe , Mensah Vigan , Kuo Tien‐Hsia , Chiou Ming‐Da , Chern Ching‐Sheng , Chang Ming‐Huei , Chien Hwa
Published: February 2015

Synoptic features of the Kuroshio at 23.75°N were quantified using nine ship‐based surveys between September 2012 and September 2014. The new ship‐based data set provides an unprecedented view of the Kuroshio east of Taiwan and suggest tremendous variability in its velocity, hydrography, volume, heat, and salt transports, and water masses. The Kuroshio maximum velocity varied in 0.7–1.4 m s−1; the core current width, delineated with the limit v ≥ 0.2 m s−1, ranged from 85 to 135 km, and the thickness varied from 400 to 600 m. A dual velocity maximum in the Kuroshio core current, though unexpected, was observed in three of nine cruises. The Kuroshio core transport, integrated from the directly measured velocity, varied between 10.46 and 22.92 Sv (1 Sv=106 m3 s−1). The corresponding heat transport referenced to 0°C was 0.838–1.793 × 1015 W, and the salt transport was 345.0–775.9 × 106 kg s−1. The geostrophic transport estimated using the thermal wind relation with the observed hydrographic data and reference velocity at 900 m is comparable to the directly measured Kuroshio transport during most of the surveys, suggesting the directly measured velocity is mostly in geostrophic balance.
Hemispheric asymmetries and seasonality of mean age of air in the lower stratosphere: Deep versus shallow branch of the Brewer‐Dobson circulation
Authors: Konopka Paul , Ploeger Felix , Tao Mengchu , Birner Thomas , Riese Martin
Published: February 2015

Based on multiannual simulations with the Chemical Lagrangian Model of the Stratosphere, (CLaMS) driven by ECMWF ERA‐Interim reanalysis, we discuss hemispheric asymmetries and the seasonality of the mean age of air (AoA) in the lower stratosphere. First, the planetary wave forcing of the Brewer‐Dobson circulation is quantified in terms of Eliassen Palm flux divergence calculated by using the isentropic coordinate θ. While the forcing of the deep branch at θ = 1000 K (around 10 hPa) has a clear maximum in each hemisphere during the respective winter, the shallow branch of the Brewer‐Dobson circulation, i.e., between 100 and 70 hPa (380 < θ < 420 K), shows almost opposite seasonality in both hemispheres with a pronounced minimum between June and September in the Southern Hemisphere. Second, we decompose the time‐tendency of AoA into the contributions of the residual circulation and of eddy mixing by analyzing the zonally averaged tracer continuity equation. In the tropical lower stratosphere between ±30°, the air becomes younger during boreal winter and older during boreal summer. During boreal winter, the decrease of AoA due to tropical upwelling outweighs aging by isentropic mixing. In contrast, weaker isentropic mixing outweighs an even weaker upwelling in boreal summer and fall making the air older during these seasons. Poleward of 60°, the deep branch locally increases AoA and eddy mixing locally decreases AoA with the strongest net decrease during spring. Eddy mixing in the Northern Hemisphere outweighs that in the Southern Hemisphere throughout the year.
The summer 2012 Greenland heat wave: In situ and remote sensing observations of water vapor isotopic composition during an atmospheric river event
Authors: Bonne Jean‐Louis , Steen‐Larsen Hans Christian , Risi Camille , Werner Martin , Sodemann Harald , Lacour Jean‐Lionel , Fettweis Xavier , Cesana Grégory , Delmotte Marc , Cattani Olivier , Vallelonga Paul , Kjær Helle Astrid , Clerbaux Cathy , Sveinbjörnsdóttir Árny Erla , Masson‐Delmotte Valérie
Published: February 2015

During 7–12 July 2012, extreme moist and warm conditions occurred over Greenland, leading to widespread surface melt. To investigate the physical processes during the atmospheric moisture transport of this event, we study the water vapor isotopic composition using surface in situ observations in Bermuda Island, South Greenland coast (Ivittuut), and northwest Greenland ice sheet (NEEM), as well as remote sensing observations (Infrared Atmospheric Sounding Interferometer (IASI) instrument on board MetOp‐A), depicting propagation of similar surface and midtropospheric humidity and δD signals. Simulations using Lagrangian moisture source diagnostic and water tagging in a regional model showed that Greenland was affected by an atmospheric river transporting moisture from the western subtropical North Atlantic Ocean, which is coherent with observations of snow pit impurities deposited at NEEM. At Ivittuut, surface air temperature, humidity, and δD increases are observed. At NEEM, similar temperature increase is associated with a large and long‐lasting ∼100‰δD enrichment and ∼15‰ deuterium excess decrease, thereby reaching Ivittuut level. We assess the simulation of this event in two isotope‐enabled atmospheric general circulation models (LMDz‐iso and ECHAM5‐wiso). LMDz‐iso correctly captures the timing of propagation for this event identified in IASI data but depict too gradual variations when compared to surface data. Both models reproduce the surface meteorological and isotopic values during the event but underestimate the background deuterium excess at NEEM. Cloud liquid water content parametrization in LMDz‐iso poorly impacts the vapor isotopic composition. Our data demonstrate that during this atmospheric river event the deuterium excess signal is conserved from the moisture source to northwest Greenland.
Modeling seismic energy propagation in highly scattering environments
Authors: Blanchette‐Guertin J.‐F. , Johnson C. L. , Lawrence J. F.
Published: February 2015

Meteoroid impacts over millions to billions of years can produce a highly fractured and heterogeneous megaregolith layer on planetary bodies such as the Moon that lack effective surface recycling mechanisms. The energy from seismic events on these bodies undergoes scattering in the fractured layer(s) and generates extensive coda wave trains that follow major seismic wave arrivals. The decay properties of these codas are affected by the planetary body's interior structure. To understand the propagation of seismic waves in such media, we model the transmission of seismic energy in highly scattering environments using an adapted phonon method. In this Monte Carlo simulation approach, we track a large number of seismic wavelets as they leave a source and we record the resulting ground deformation each time a wavelet reaches a surface receiver. Our method provides the first numerical global modeling of 3‐D scattering, with user‐defined power law distributions of scatterer length scales and frequency‐dependent intrinsic attenuation, under the assumption of 1‐D background velocity models. We model synthetic signals for simple, but highly scattering interior models and vary the model parameters independently to assess their individual effects on the coda. Results show that the magnitude of the decay times is most affected by the background velocity model, in particular the presence of shallow low‐velocity layers, the event source depth, and the intrinsic attenuation level. The decay times are also controlled to a lesser extent by the size‐frequency distribution of scatterers, the thickness of the scattering layer, and the impedance contrast at the scatterers.
Spectral comparison and stability of red regions on Jupiter
Authors: Simon Amy A. , Sanchez‐Lavega Agustin , Legarreta Jon , Sanz‐Requena Jose Francisco , Perez‐Hoyos Santiago , Garcia‐Melendo Enrique , Carlson Robert W.
Published: February 2015

A rare red cyclone visible on Jupiter in 1994 and 1995 falls in a class of vortices that are intensely colored, yet low altitude, unlike the Great Red Spot (GRS). Dynamical modeling indicates that the presence of nearby anticyclones both aids in formation and lead to the destruction of the cyclone. A study of absolute spectral reflectance from Hubble Space Telescope imaging data shows that GRS is not typically the “reddest” region of the planet. Rather, transient red cyclones and the reddest parts of the North Equatorial Belt show less reflectance than the GRS at all wavelengths, with enhanced absorption at wavelengths near 500 nm. Temporal analysis shows that the darkest regions of the North Equatorial Belt and transient red cyclones are relatively constant in color from 1995 to 2014, while the spectral slope and absolute brightness of the GRS core vary over time. Laboratory data of colored materials that yield a good qualitative fit to the GRS spectrum do not match the spectra of other regions, and wavelengths from 400 to 700 nm may be most diagnostic of chromophore identification.
Maskelynite formation via solid‐state transformation: Evidence of infrared and X‐ray anisotropy
Authors: Jaret Steven J. , Woerner William R. , Phillips Brian L. , Ehm Lars , Nekvasil Hanna , Wright Shawn P. , Glotch Timothy D.
Published: February 2015

We present the results of a combined study of shocked labradorite from the Lonar crater, India, using optical microscopy, micro‐Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, high‐energy X‐ray total scattering experiments, and micro‐Fourier transform infrared (micro‐FTIR) spectroscopy. We show that maskelynite of shock class 2 is structurally more similar to fused glass than to crystalline plagioclase. However, there are slight but significant differences—preservation of original preimpact igneous zoning, anisotropy at infrared wavelengths, X‐ray anisotropy, and preservation of some intermediate range order—which are all consistent with a solid‐state transformation from plagioclase to maskelynite.
A study of the composition, characteristics, and origin of modern driftwood on the western coast of Nunavik (Quebec, Canada)
Authors: Steelandt Stéphanie , Marguerie Dominique , Bhiry Najat , Delwaide Ann
Published: February 2015

Data concerning driftwood is of value to researchers in fields as diverse as oceanography, geomorphology, and human occupation. Yet studies on the subject in the Canadian Arctic have only recently been carried out, and the present study is the first in Nunavik (northeastern Canada). This paper documents the composition, characteristics, and origin of modern driftwood pieces on the beaches of the eastern coast of Hudson Bay. A total of 1057 samples from Ivujivik, Akulivik, Inukjuak, and Umiujaq were identified as belonging to four coniferous species (Picea sp., Larix sp., Abies sp. likely balsamea, and Thuja sp. likely occidentalis) and four deciduous species (Salix sp., Populus sp., Alnus sp., and Betula sp., likely papyrifera). Spruce largely predominate; white birch, white cedar, and fir are rare. The presence of the latter species proves that some of the wood originated from south‐southeast of James Bay. Driftwood found in the southern area (Umiujaq) are more numerous, larger, and less degraded than driftwood in the north (Ivujivik). However, many large coniferous samples were found as far north as Akulivik, indicating that they likely traveled a great distance, unlike the smaller wood specimens (especially deciduous samples). All of the wood that we analyzed died relatively young, with an average age of 63 years for conifers and 23 years for deciduous. Measurements of ring widths and the cross‐dating of samples with existing reference chronologies of living trees along Hudson Bay and James Bay revealed several possible correlations and origins for wood found in same areas.
Thermodynamics in the hydrologic response: Travel time formulation and application to Alpine catchments
Authors: Comola F. , Schaefli B. , Rinaldo A. , Lehning M.
Published: February 2015

This paper presents a spatially explicit model for hydrothermal response simulations of Alpine catchments, accounting for advective and nonadvective energy fluxes in stream networks characterized by arbitrary degrees of geomorphological complexity. The relevance of the work stems from the increasing scientific interest concerning the impacts of the warming climate on water resources management and temperature‐controlled ecological processes. The description of the advective energy fluxes is cast in a travel time formulation of water and energy transport, resulting in a closed form solution for water temperature evolution in the soil compartment. The application to Alpine catchments hinges on the boundary conditions provided by the fully distributed and physically based snow model Alpine3D. The performance of the simulations is illustrated by comparing modeled and measured hydrographs and thermographs at the outlet of the Dischma catchment (45 km2) in the Swiss Alps. The Monte Carlo calibration shows that the model is robust and that a simultaneous fitting of streamflow and stream temperature reduces the uncertainty in the hydrological parameters estimation. The calibrated model also provides a good fit to the measurements in the validation period, suggesting that it could be employed for predictive applications, both for hydrological and ecological purposes. The temperature of the subsurface flow, as described by the proposed travel time formulation, proves warmer than the stream temperature during winter and colder during summer. Finally, the spatially explicit results of the model during snowmelt show a notable hydrothermal spatial variability in the river network, owing to the small spatial correlation of infiltration and meteorological forcings in Alpine regions.
Thermal Stability of the Commercial Mg‐PSZ Powders
Authors: Pavlyuchkov Dmytro , Martin Stefan , Reichel Benedikt , Weigelt Christian , Fabrichnaya Olga
Published: February 2015

Using X‐ray diffraction and scanning electron microscopy two commercial Mg‐PSZ ceramics were studied regarding their thermal stability at 1350 °C. The Mg‐PSZ material was investigated in as‐received, sintered, and powdered states. Drastic increasing of the m‐ZrO2 content was observed for the as‐received powders. Whereas the Mg‐PSZ ceramics sintered at 1600 °C exhibit certainly better thermal stability. Two mechanisms of thermal destabilization were defined using observations of the sintered Mg‐PSZ material. Influence of the particle size of Mg‐PSZ on its thermal stability is defined.
Signatures of Quantized Energy States in Solution‐Processed Ultrathin Layers of Metal‐Oxide Semiconductors and Their Devices
Authors: Labram John G. , Lin Yen‐Hung , Zhao Kui , Li Ruipeng , Thomas Stuart R. , Semple James , Androulidaki Maria , Sygellou Lamprini , McLachlan Martyn , Stratakis Emmanuel , Amassian Aram , Anthopoulos Thomas D.
Published: February 2015

Physical phenomena such as energy quantization have to‐date been overlooked in solution‐processed inorganic semiconducting layers, owing to heterogeneity in layer thickness uniformity unlike some of their vacuum‐deposited counterparts. Recent reports of the growth of uniform, ultrathin (<5 nm) metal‐oxide semiconductors from solution, however, have potentially opened the door to such phenomena manifesting themselves. Here, a theoretical framework is developed for energy quantization in inorganic semiconductor layers with appreciable surface roughness, as compared to the mean layer thickness, and present experimental evidence of the existence of quantized energy states in spin‐cast layers of zinc oxide (ZnO). As‐grown ZnO layers are found to be remarkably continuous and uniform with controllable thicknesses in the range 2–24 nm and exhibit a characteristic widening of the energy bandgap with reducing thickness in agreement with theoretical predictions. Using sequentially spin‐cast layers of ZnO as the bulk semiconductor and quantum well materials, and gallium oxide or organic self‐assembled monolayers as the barrier materials, two terminal electronic devices are demonstrated, the current–voltage characteristics of which resemble closely those of double‐barrier resonant‐tunneling diodes. As‐fabricated all‐oxide/hybrid devices exhibit a characteristic negative‐differential conductance region with peak‐to‐valley ratios in the range 2–7.
Investigation of Thermomechanical Properties of UHMWPE/Graphene Oxide Nanocomposites Prepared by In situ Ziegler–Natta Polymerization
Authors: Bahrami Hiva , Ramazani S. A. Ahmad , Kheradmand Amanj , Shafiee Mojtaba , Baniasadi Hossein
Published: February 2015

The graphene‐based Ziegler–Natta catalyst has been used to prepare ultrahigh molecular weight polyethylene/graphene oxide (UHMWPE/GO) nanocomposite via in situ polymerization. The morphological investigations have been conducted using X‐ray diffraction patterns and scanning electron microscopy method. The obtained results indicated that no diffraction peak is detected in a GO pattern, which could be due to the exfoliation of graphene nanosheets in the UHMWPE matrix. Morphological investigations indicated that GO nanosheets are dispersed almost uniformly in polymeric matrix, and that there should exist a good interaction between nanofillers and matrix. The mechanical properties of the nanocomposites were studied, and the results showed that the Young (tensile) modulus and tensile strength of the prepared nanocomposites were significantly increased by increasing the filler content, which should be due to the high aspect ratio of GO plates and their uniform dispersion in the UHMWPE matrix. The thermogravimetery investigations reveal that the thermal stability of nanocomposites increase with increasing GO content and that initiation thermal decomposition temperature shifts to higher values.
Nanoflake‐Assembled Hierarchical Na3V2(PO4)3/C Microflowers: Superior Li Storage Performance and Insertion/Extraction Mechanism
Authors: An Qinyou , Xiong Fangyu , Wei Qiulong , Sheng Jinzhi , He Liang , Ma Dongling , Yao Yan , Mai Liqiang
Published: February 2015

Na3V2(PO4)3 (NVP) has excellent electrochemical stability and fast ion diffusion coefficient due to the 3D Na+ ion superionic conductor framework, which make it an attractive cathode material for lithium ion batteries (LIBs). However, the electrochemical performance of NVP needs to be further improved for applications in electric vehicles and hybrid electric vehicles. Here, nanoflake‐assembled hierarchical NVP/C microflowers are synthesized using a facile method. The structure of as‐synthesized materials enhances the electrochemical performance by improving the electron conductivity, increasing electrode–electrolyte contact area, and shortening the diffusion distance. The as‐synthesized material exhibits a high capacity (230 mAh g−1), excellent cycling stability (83.6% of the initial capacity is retained after 5000 cycles), and remarkable rate performance (91 C) in hybrid LIBs. Meanwhile, the hybrid LIBs with the structure of NVP || 1 m LiPF6/EC (ethylene carbonate) + DMC (dimethyl carbonate) || NVP and Li4Ti5O12 || 1 m LiPF6/EC + DMC || NVP are assembled and display capacities of 79 and 73 mAh g−1, respectively. The insertion/extraction mechanism of NVP is systematically investigated, based on in situ X‐ray diffraction. The superior electrochemical performance, the design of hybrid LIBs, and the insertion/extraction mechanism investigation will have profound implications for developing safe and stable, high‐energy, and high‐power LIBs.
Viscosity and density of isobutane measured in wide ranges of temperature and pressure including the near‐critical region
Authors: Herrmann Sebastian , Hassel Egon , Vogel Eckhard
Published: February 2015

Accurate ηρpT data for isobutane were measured for nine isotherms between 298.15 and 498.15 K using simultaneously a vibrating‐wire viscometer and a single‐sinker densimeter. The maximum pressure was 93% of the saturated for subcritical isotherms and 30 MPa for supercritical isotherms. The density measurements are generally characterized by an uncertainty of ≤0.1%. Allocation errors for temperature and pressure influence significantly their uncertainty in the near‐critical region. A comparison with the equation of state by Bücker and Wagner shows agreement normally within ±0.1%. The near‐critical isotherm 410.15 K reveals differences to −3.7% exceeding the uncertainty of 1.9%. The uncertainty in viscosity is ≤0.3%. The comparison with the correlation of Vogel et al. yields deviations exceeding the uncertainty of the correlation (3%). The critical enhancement becomes evident for the near‐critical isotherm amounting to 1.4%. The new data will improve the viscosity surface correlation. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3116–3137, 2015
Methylcyclohexane dehydrogenation for hydrogen production via a bimodal catalytic membrane reactor
Authors: Meng Lie , Yu Xin , Niimi Takuya , Nagasawa Hiroki , Kanezashi Masakoto , Yoshioka Tomohisa , Tsuru Toshinori
Published: February 2015

The dehydrogenation of methylcyclohexane (MCH) to toluene (TOL) for hydrogen production was theoretically and experimentally investigated in a bimodal catalytic membrane reactor (CMR), that combined Pt/Al2O3 catalysts with a hydrogen‐selective organosilica membrane prepared via sol‐gel processing using bis(triethoxysilyl) ethane (BTESE). Effects of operating conditions on the membrane reactor performance were systematically investigated, and the experimental results were in good agreement with those calculated by a simulation model with a fitted catalyst loading. With H2 extraction from the reaction stream to the permeate stream, MCH conversion at 250°C was significantly increased beyond the equilibrium conversion of 0.44–0.86. Because of the high H2 selectivity and permeance of BTESE‐derived membranes, a H2 flow with purity higher than 99.8% was obtained in the permeate stream, and the H2 recovery ratio reached 0.99 in a pressurized reactor. A system that combined the CMR with a fixed‐bed prereactor was proposed for MCH dehydrogenation. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1628–1638, 2015
Long‐term health outcomes of work‐related injuries among construction workers—findings from the National Longitudinal Survey of Youth
Authors: Dong Xiuwen Sue , Wang Xuanwen , Largay Julie A. , Sokas Rosemary
Published: February 2015

Background

This study examined the relationship between work‐related injuries and health outcomes among a cohort of blue‐collar construction workers.

Materials and Methods

Data were from the National Longitudinal Survey of Youth, 1979 cohort (NLSY79; n = 12,686). A range of health outcomes among blue‐collar construction workers (n = 1,435) were measured when they turned age 40 (1998–2006) and stratified by these workers' prior work‐related injury status between 1988 and 2000. Univariate and multivariate analyses were conducted to measure differences among subgroups.

Results

About 38% of the construction cohort reported injuries resulting in days away from work (DAFW); another 15% were injured but reported no DAFW (NDAFW). At age 40, an average of 10 years after injury, those with DAFW injury had worse self‐reported general health and mental health, and more diagnosed conditions and functional limitations than those without injury. This difference was statistically significant after controlling for major demographics.

Discussion

Adverse health effects from occupational injury among construction workers persist longer than previously documented. Am. J. Ind. Med. 58:308–318, 2015. © 2015 Wiley Periodicals, Inc.
Breast cancer incidence in a cohort of U.S. flight attendants
Authors: Schubauer‐Berigan Mary K. , Anderson Jeri L. , Hein Misty J. , Little Mark P. , Sigurdson Alice J. , Pinkerton Lynne E.
Published: February 2015

Background

Flight attendants may have elevated breast cancer incidence (BCI). We evaluated BCI's association with cosmic radiation dose and circadian rhythm disruption among 6,093 female former U.S. flight attendants.

Methods

We collected questionnaire data on BCI and risk factors for breast cancer from 2002–2005. We conducted analyses to evaluate (i) BCI in the cohort compared to the U.S. population; and (ii) exposure‐response relations. We applied an indirect adjustment to estimate whether parity and age at first birth (AFB) differences between the cohort and U.S. population could explain BCI that differed from expectation.

Results

BCI was elevated but may be explained by lower parity and older AFB in the cohort than among U.S. women. BCI was not associated with exposure metrics in the cohort overall. Significant positive associations with both were observed only among women with parity of three or more.

Conclusions

Future cohort analyses may be informative on the role of these occupational exposures and non‐occupational risk factors. Am. J. Ind. Med. 58:252–266, 2015. © 2015 Wiley Periodicals, Inc.
Airborne fiber size characterization in exposure estimation: Evaluation of a modified transmission electron microcopy protocol for asbestos and potential use for carbon nanotubes and nanofibers
Authors: Dement John M. , Kuempel Eileen D. , Zumwalde Ralph D. , Ristich Anna M. , Fernback Joseph E. , Smith Randall J.
Published: February 2015

Background

Airborne fiber size has been shown to be an important factor relative to adverse lung effects of asbestos and suggested in animal studies of carbon nanotubes and nanofibers (CNT/CNF).

Materials and Methods

The International Standards Organization (ISO) transmission electron microscopy (TEM) method for asbestos was modified to increase the statistical precision of fiber size determinations, improve efficiency, and reduce analysis costs. Comparisons of the fiber size distributions and exposure indices by laboratory and counting method were performed.

Results

No significant differences in size distributions by the ISO and modified ISO methods were observed. Small but statistically‐significant inter‐lab differences in the proportion of fibers in some size bins were found, but these differences had little impact on the summary exposure indices. The modified ISO method produced slightly more precise estimates of the long fiber fraction (>15 μm).

Conclusions

The modified ISO method may be useful for estimating size‐specific structure exposures, including CNT/CNF, for risk assessment research. Am. J. Ind. Med. 58:494–508, 2015. © 2015 Wiley Periodicals, Inc.
The Inclusion of Women in Studies of Occupational Cancer: A Review of the Epidemiologic Literature From 1991–2009
Authors: Hohenadel Karin , Raj Priyanka , Demers Paul A. , Zahm Shelia Hoar , Blair Aaron
Published: February 2015

Introduction

Since the early 1990s, researchers have been concerned with the low rate at which women are included in epidemiologic studies of occupational cancer. A previous evaluation determined that one‐third of articles published between 1970 and 1990 included women.

Methods

To assess whether there has been an improvement in recent years, papers on occupational cancer between 1991 and 2009 were reviewed in fifteen journals.

Results

The proportion of articles that included men remained stable around 90%, while the proportion of articles that included women increased substantially, from 39% in 1991–1995 to 62% in 2006–2009. Articles that assessed risk among men only or men and women presented a higher number of risk estimates and were more likely to evaluate dose‐response relationships than studies including women.

Conclusions

Despite advances in the inclusion of women in studies of occupational cancer, disparities remain in the number of studies of occupational cancer and depth of analysis in studies that included women. Am. J. Ind. Med. 58:276–281, 2015. © 2015 Wiley Periodicals, Inc.
Movement disorders and other motor abnormalities in adults with 22q11.2 deletion syndrome
Authors: Boot Erik , Butcher Nancy J , van Amelsvoort Thérèse AMJ , Lang Anthony E , Marras Connie , Pondal Margarita , Andrade Danielle M , Fung Wai Lun Alan , Bassett Anne S
Published: February 2015

Movement abnormalities are frequently reported in children with 22q11.2 deletion syndrome (22q11.2DS), but knowledge in this area is scarce in the increasing adult population. We report on five individuals illustrative of movement disorders and other motor abnormalities in adults with 22q11.2DS. In addition to an increased susceptibility to neuropsychiatric disorders, seizures, and early‐onset Parkinson disease, the underlying brain dysfunction associated with 22q11.2DS may give rise to an increased vulnerability to multiple movement abnormalities, including those influenced by medications. Movement abnormalities may also be secondary to treatable endocrine diseases and congenital musculoskeletal abnormalities. We propose that movement abnormalities may be common in adults with 22q11.2DS and discuss the implications and challenges important to clinical practice. © 2015 Wiley Periodicals, Inc.
One‐Pot Synthesis of 2‐Arylbenzoxazoles by Gas‐Free Carbonylation using Dicobalt Octacarbonyl as a Solid Carbon Monoxide Source
Authors: Baburajan Poongavanam , Elango Kuppanagounder P.
Published: February 2015

A simple, mild, and facile carbonylation procedure to synthesise 2‐arylbenzoxazole derivatives using dicobalt octacarbonyl [Co2(CO)8] as an in situ carbon monoxide source is described. This method is tolerant of a variety of functional groups and the compounds are obtained in high to excellent yields. Moreover, the reaction is performed in one‐pot with a simple workup procedure. The choice of catalytic system as well as base is important in order to ensure a high yield and chemoselectivity in the reaction. Both electron‐rich and electron‐deficient aryl bromides worked well in this reaction.
Diversity of nutcracking tool sites used bySapajus libidinosusin BrazilianCerrado
Authors: Mendes Francisco Dyonísio C. , Cardoso Raphael Moura , Ottoni Eduardo B. , Izar Patrícia , Villar Daniell Nunes A. , Marquezan Rogério F.
Published: February 2015

Cracking nuts with tools is a behavior documented in a small number of populations of tufted capuchins, mainly in semi‐aridCaatingaandCaatinga–Cerradotransitional environments of northeastern Brazil. Only one of these populations inhabits the less aridCerradoin Central Brazil, where environments are composed of a heterogeneous mosaic of fields, savannas and forest formations. We conducted surveys in 10 of 20 localities where nutcracking by capuchins was reported by the local inhabitants in theCerrradoof Northern Goiás and Tocantins. Our purpose was to evaluate nutcracking sites (anvils and associated hammers and nuts) based on indirect evidence of extensive pounding of nuts and seeds. Nutcracking was confirmed at all 10 surveyed localities. A total of 270 sites were identified. Surveyed localities included areas that were ecologically similar to those where capuchins crack nuts inCaatinga, as well as less arid localities with more typicalCerradohabitat. Anvils and hammers were made of materials including quartz, limestone, sandstone and wood, and displayed a wider range of sizes (i.e., 60–3,750 g for hammers’ weight) than reported at previously studied localities. Nuts of seven genera were found in association with anvils and hammers. We conclude that nutcracking by capuchins are not restricted to arid environments and argue that the occurrence and diversity of nutcracking tool sites result from complex interactions of environmental variables (e.g., availability of food and mineral resources, density of canopy cover) and social variables (e.g., spatial cohesiveness and tolerance among group members) that need to be examined through long‐term research of habituated groups. Localities in theCerradoof Northern Goiás and Tocantins vary considerable in the ecological conditions faced by wild groups, and therefore offer the opportunity to examine these interactions. Am. J. Primatol. 77:535–546, 2015. © 2015 Wiley Periodicals, Inc.
Influence of age, reproductive cycling status, and menstruation on the vaginal microbiome in baboons (Papio anubis)
Authors: Uchihashi M. , Bergin I. L. , Bassis C. M. , Hashway S. A. , Chai D. , Bell J. D.
Published: February 2015

The vaginal microbiome is believed to influence host health by providing protection from pathogens and influencing reproductive outcomes such as fertility and gestational length. In humans, age‐associated declines in diversity of the vaginal microbiome occur in puberty and persist into adulthood. Additionally, menstruation has been associated with decreased microbial community stability. Adult female baboons, like other non‐human primates (NHPs), have a different and highly diverse vaginal microbiome compared to that of humans, which is most commonly dominated by Lactobacillus spp. We evaluated the influence of age, reproductive cycling status (cycling vs. non‐cycling) and menstruation on the vaginal microbiome of 38 wild‐caught, captive female olive baboons (Papio anubis) by culture‐independent sequencing of the V3–V5 region of the bacterial 16S rRNA gene. All baboons had highly diverse vaginal microbial communities. Adult baboons had significantly lower microbial diversity in comparison to subadult baboons, which was attributable to decreased relative abundance of minor taxa. No significant differences were detected based on cycling state or menstruation. Predictive metagenomic analysis showed uniformity in relative abundance of metabolic pathways regardless of age, cycle stage, or menstruation, indicating conservation of microbial community functions. This study suggests that selection of an optimal vaginal microbial community occurs at puberty. Since decreased diversity occurs in both baboons and humans at puberty, this may reflect a general strategy for selection of adult vaginal microbial communities. Comparative evaluation of vaginal microbial community development and composition may elucidate mechanisms of community formation and function that are conserved across host species or across microbial community types. These findings have implications for host health, evolutionary biology, and microbe‐host ecosystems. Am. J. Primatol. 77:563–578, 2015. © 2015 Wiley Periodicals, Inc.
Paternal lineages in Libya inferred from Y‐chromosome haplogroups
Authors: Triki‐Fendri Soumaya , Sánchez‐Diz Paula , Rey‐González Danel , Ayadi Imen , Carracedo Ángel , Rebai Ahmed
Published: February 2015

Many studies based on genetic diversity of North African populations have contributed to elucidate the modelling of the genetic landscape in this region. North Africa is considered as a distinct spatial‐temporal entity on geographic, archaeological, and historical grounds, which has undergone the influence of different human migrations along its shaping. For instance, Libya, a North African country, was first inhabited by Berbers and then colonized by a variety of ethnic groups like Phoenicians, Greeks, Romans, Arabs and, in recent times, Italians. In this study, we contribute to clarify the genetic variation of Libya and consequently, of North African modern populations, by the study of Libyan male lineages. A total of 22 Y‐chromosome‐specific SNPs were genotyped in a sample of 175 Libyan males, allowing the characterization of 18 Y‐chromosomal haplogroups. The obtained data revealed a predominant Northwest African component represented by haplogroup E‐M81 (33.7%) followed by J(xJ1a,J2)‐M304 (27.4%), which is postulated to have a Middle Eastern origin. The comparative study with other populations (∼5,400 individuals from North Africa, Middle East, Sub‐Saharan Africa, and Europe) revealed a general genetic homogeneity among North African populations (FST = 5.3 %; P‐value < 0.0001). Overall, the Y‐haplogroup diversity in Libya and in North Africa is characterized by two genetic components. The first signature is typical of Berber‐speaking people (E‐M81), the autochthonous inhabitants, whereas the second is (J(xJ1a,J2)‐M304), originating from Arabic populations. This is in agreement with the hypothesis of an Arabic expansion from the Middle East, shaping the North African genetic landscape. Am J Phys Anthropol 157:242–251, 2015. © 2015 Wiley Periodicals, Inc.
Familial risk of chronic rhinosinusitis with and without nasal polyposis: genetics or environment
Authors: Oakley Gretchen M. , Curtin Karen , Orb Quinn , Schaefer Carole , Orlandi Richard R. , Alt Jeremiah A.
Published: February 2015

Background

Chronic rhinosinusitis (CRS) is a highly prevalent inflammatory condition, with significant effects on morbidity and quality of life, yet little is known about its pathogenesis. Preliminary evidence suggests there is a heritable component to the multifactorial etiology of CRS; however, our understanding of this genetic susceptibility is limited.

Methods

Using an extensive genealogical database linked to medical records, the risk of CRS with nasal polyps (CRSwNP) and without polyps (CRSsNP) was calculated for relatives and spouses of adult probands (1638 CRSwNP and 24,200 CRSsNP patients diagnosed between 1996 and 2011) and were compared to random population controls matched 5:1 on sex and birth year from Cox regression models.

Results

First‐degree relatives (1stDRs) of CRSwNP patients demonstrated a 4.1‐fold increased risk (p < 10−3) of carrying the same diagnosis, whereas second‐degree relatives (2ndDRs) demonstrated a 3.3‐fold increased risk (p < 0.004), compared to controls. In CRSsNP patients, 1stDRs were at 2.4‐fold increased risk (p < 10−15), whereas 2ndDRs were at 1.4‐fold increased risk (p < 10−15) of the same diagnosis. Third‐degree relatives (3rdDRs) had a slight increased risk at 1.1‐fold (p < 10−7). Spouses of CRSsNP patients, who likely share environmental circumstances, exhibited a 2‐fold increased risk (p < 10−15). No increased risk was observed in spouses of CRSwNP patients.

Conclusion

In the largest population study to date, a significant familial risk is confirmed in CRSwNP and CRSsNP, which may have a shared genetic and environmental component. Further understanding of the genetic basis of CRS and its interplay with environment factors could clarify disease etiology and lead to more effective targeted treatments.
The Nucleoside Uridine Isolated in the Gas Phase
Authors: Peña Isabel , Cabezas Carlos , Alonso José L.
Published: February 2015

Herein we present the first experimental observation of the isolated nucleoside uridine, placed in the gas phase by laser ablation and characterized by Fourier transform (FT) microwave techniques. Free from the bulk effects of their native environments, anti/C2′‐endo‐g+ conformation has been revealed as the most stable form of uridine. Intramolecular hydrogen bonds involving uracil and ribose moieties have been found to play an important role in the stabilization of the nucleoside.
Advanced Biotechnology: Metabolically Engineered Cells for the Bio‐Based Production of Chemicals and Fuels, Materials, and Health‐Care Products
Authors: Becker Judith , Wittmann Christoph
Published: February 2015

Corynebacterium glutamicum, Escherichia coli, and Saccharomyces cerevisiae in particular, have become established as important industrial workhorses in biotechnology. Recent years have seen tremendous progress in their advance into tailor‐made producers, driven by the upcoming demand for sustainable processes and renewable raw materials. Here, the diversity and complexity of nature is simultaneously a challenge and a benefit. Harnessing biodiversity in the right manner through synergistic progress in systems metabolic engineering and chemical synthesis promises a future innovative bio‐economy.
Photonic Patterns Printed in Chiral Nematic Mesoporous Resins
Authors: Khan Mostofa K. , Bsoul Anas , Walus Konrad , Hamad Wadood Y. , MacLachlan Mark J.
Published: February 2015

Chiral nematic mesoporous phenol‐formaldehyde resins, which were prepared using cellulose nanocrystals as a template, can be used as a substrate to produce latent photonic images. These resins undergo swelling, which changes their reflected color. By writing on the films with chemical inks, the density of methylol groups in the resin changes, subsequently affecting their degree of swelling and, consequently, their color. Writing on the films gives latent images that are revealed only upon swelling of the films. Using inkjet printing, it is possible to make higher resolution photonic patterns both as text and images that can be visualized by swelling and erased by drying. This novel approach to printing photonic patterns in resin films may be applied to anti‐counterfeit tags, signage, and decorative applications.
A TEMPO‐Free Copper‐Catalyzed Aerobic Oxidation of Alcohols
Authors: Xu Boran , Lumb Jean‐Philip , Arndtsen Bruce A.
Published: February 2015

The copper‐catalyzed aerobic oxidation of primary and secondary alcohols without an external N‐oxide co‐oxidant is described. The catalyst system is composed of a Cu/diamine complex inspired by the enzyme tyrosinase, along with dimethylaminopyridine (DMAP) or N‐methylimidazole (NMI). The Cu catalyst system works without 2,2,6,6‐tetramethyl‐l‐piperidinoxyl (TEMPO) at ambient pressure and temperature, and displays activity for un‐activated secondary alcohols, which remain a challenging substrate for catalytic aerobic systems. Our work underscores the importance of finding alternative mechanistic pathways for alcohol oxidation, which complement Cu/TEMPO systems, and demonstrate, in this case, a preference for the oxidation of activated secondary over primary alcohols.
The Catalytic Mechanism of Human Parainfluenza Virus Type 3 Haemagglutinin‐Neuraminidase Revealed
Authors: Dirr Larissa , El‐Deeb Ibrahim M. , Guillon Patrice , Carroux Cindy J. , Chavas Leonard M. G. , von Itzstein Mark
Published: February 2015

Human parainfluenza virus type 3 (hPIV‐3) is one of the leading causes for lower respiratory tract disease in children, with neither an approved antiviral drug nor vaccine available to date. Understanding the catalytic mechanism of human parainfluenza virus haemagglutinin‐neuraminidase (HN) protein is key to the design of specific inhibitors against this virus. Herein, we used 1H NMR spectroscopy, X‐ray crystallography, and virological assays to study the catalytic mechanism of the HN enzyme activity and have identified the conserved Tyr530 as a key amino acid involved in catalysis. A novel 2,3‐difluorosialic acid derivative showed prolonged enzyme inhibition and was found to react and form a covalent bond with Tyr530. Furthermore, the novel derivative exhibited enhanced potency in virus blockade assays relative to its Neu2en analogue. These outcomes open the door for a new generation of potent inhibitors against hPIV‐3 HN.
Manufacturing and mechanical response optimization of epoxy resin/Luffa Cylindrica composite
Authors: Papanicolaou George C. , Psarra Erato , Anastasiou Dimitris
Published: February 2015

The present investigation pertains to the existent possibilities of the fibrous natural material Luffa Cylindrica (LC) as reinforcement to thermoset resins. The main purpose was the manufacturing of an engineering material that would, simultaneously, lead to a more sustainable world. In an effort to optimize the final mechanical properties, semi‐ green Epoxy Resin/Luffa Cylindrica (ER/LC) composites were manufactured, applying a number of different manufacturing parameters combinations. The manufacturing parameters taken into account were: (a) fiber chemical treatments; (b) the external applied pressure during curing; (c) number of plies; (d) stacking sequence effect; (e) LC's structural characteristics; and (f) the influence of fiber weight fraction on composite's behavior. The elastic flexural response of the composite polymer was found improved with respect to neat polymer's response due to fibers' nature and the applied manufacturing optimization process. This improvement was reflected to material's stiffness which optimally increased by 48% for a mechanically applied pressure of 4.6 kPa during curing. Additionally, LC fibers chemically treated with Acetone/ CH3COOH 1 wt % led to stiffness' improvement up to 30%. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41992.
Aqueous, interfacial, and electrochemical polymerization pathways of aniline with thiophene: Nano size materials for supercapacitor
Authors: Male Umashankar , Singu Bal Sydulu , Srinivasan Palaniappan
Published: February 2015

Aniline was mixed with thiophene and oxidized by ammonium persulfate in the presence of sulfuric acid via an aqueous polymerization pathway (PAT‐AP). Aqueous polymerization was also carried by sodium lauryl sulfate surfactant, and also by interfacial and electrochemical polymerization pathways. Polymers prepared were characterized by physical, spectral, and electrochemical methods. Nanofibers (30–60 nm diameter) was obtained in the case of aqueous polymerization pathway, whereas interfacial (40–60 nm) and electrochemical polymerization pathways show particulate (500–600 nm) morphology. Polymer samples were used as electrode materials in supercapacitor. Among the four different pathways, PAT‐AP nanofibers show higher capacitance of 614 F g−1 at 1 mV s−1. The values of specific capacitance, energy, and power densities of PAT‐AP were found to be 400 F g−1, 20 W h kg−1 and 1200 W kg−1, respectively, at a current density of 2 A g−1. The retention capacitance is 78% after completion of 1000 cycles. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42013.