bluuebunny/crossref_metadata_2025 huggingface dataset:
Arctic gypsum endoliths: a biogeochemical characterization of a viable and active microbial community
Authors: Ziolkowski L. A. , Mykytczuk N. C. S. , Omelon C. R. , Johnson H. , Whyte L. G. , Slater G. F.
Published: November 2013

Abstract. Extreme environmental conditions such as those found in the polar regions on Earth are thought to test the limits of life. Microorganisms living in these environments often seek protection from environmental stresses such as high UV exposure, desiccation and rapid temperature fluctuations, with one protective habitat found within rocks. Such endolithic microbial communities, which often consist of bacteria, fungi, algae and lichens, are small-scale ecosystems comprised of both producers and consumers. However, the harsh environmental conditions experienced by polar endolithic communities are thought to limit microbial diversity and therefore the rate at which they cycle carbon. In this study, we characterized the microbial community diversity, turnover rate and microbe–mineral interactions of a gypsum-based endolithic community in the polar desert of the Canadian high Arctic. 16S/18S/23S rRNA pyrotag sequencing demonstrated the presence of a diverse community of phototrophic and heterotrophic bacteria, archaea, algae and fungi. Stable carbon isotope analysis of the viable microbial membranes, as phospholipid fatty acids and glycolipid fatty acids, confirmed the diversity observed by molecular techniques and indicated that present-day atmospheric carbon is assimilated into the microbial community biomass. Uptake of radiocarbon from atmospheric nuclear weapons testing during the 1960s into microbial lipids was used as a pulse label to determine that the microbial community turns over carbon on the order of 10 yr, equivalent to 4.4 g C m−2 yr−1 gross primary productivity. Scanning electron microscopy (SEM) micrographs indicated that mechanical weathering of gypsum by freeze–thaw cycles leads to increased porosity, which ultimately increases the habitability of the rock. In addition, while bacteria were adhered to these mineral surfaces, chemical analysis by micro-X-ray fluorescence (μ-XRF) spectroscopy suggests little evidence for microbial alteration of minerals, which contrasts with other endolithic habitats. While it is possible that these communities turn over carbon quickly and leave little evidence of microbe–mineral interaction, an alternative hypothesis is that the soluble and friable nature of gypsum and harsh conditions lead to elevated erosion rates, limiting microbial residence times in this habitat. Regardless, this endolithic community represents a microbial system that does not rely on a nutrient pool from the host gypsum cap rock, instead receiving these elements from allochthonous debris to maintain a more diverse and active community than might have been predicted in the polar desert of the Canadian high Arctic.
The declining uptake rate of atmospheric CO2 by land and ocean sinks
Authors: Raupach M. R. , Gloor M. , Sarmiento J. L. , Canadell J. G. , Frölicher T. L. , Gasser T. , Houghton R. A. , Le Quéré C. , Trudinger C. M.
Published: November 2013

Abstract. Through 1959–2012, an airborne fraction (AF) of 44% of total anthropogenic CO2 emissions remained in the atmosphere, with the rest being taken up by land and ocean CO2 sinks. Understanding of this uptake is critical because it greatly alleviates the emissions reductions required for climate mitigation. An observable quantity that reflects sink properties more directly than the AF is the CO2 sink rate (kS), the combined land-ocean CO2 sink flux per unit excess atmospheric CO2 above preindustrial levels. Here we show from observations that kS declined over 1959–2012 by a factor of about 1 / 3, implying that CO2 sinks increased more slowly than excess CO2. We attribute the decline in kS to four mechanisms: slower-than-exponential CO2 emissions growth (~ 35% of the trend), volcanic eruptions (~ 25%), sink responses to climate change (~ 20%), and nonlinear responses to increasing CO2, mainly oceanic (~ 20%). The first of these mechanisms is associated purely with extrinsic forcings, and the last two with intrinsic, nonlinear responses of sink processes to changes in climate and atmospheric CO2. Our results indicate that the effects of these intrinsic, nonlinear responses are already detectable in the global carbon cycle. Although continuing future decreases in kS will occur under all plausible CO2 emission scenarios, the rate of decline varies between scenarios in non-intuitive ways because extrinsic and intrinsic mechanisms respond in opposite ways to changes in emissions: extrinsic mechanisms cause kS to decline more strongly with increasing mitigation, while intrinsic mechanisms cause kS to decline more strongly under high-emission, low-mitigation scenarios as the carbon–climate system is perturbed further from a~near-linear regime.
Comparing modelled fire dynamics with charcoal records for the Holocene
Authors: Brücher T. , Brovkin V. , Kloster S. , Marlon J. R. , Power M. J.
Published: November 2013

Abstract. An Earth System model of intermediate complexity, CLIMBER-2, and a land surface model JSBACH that represents vegetation dynamically are used to simulate natural fire dynamics through the last 8000 yr. Output variables of the fire model (burned area and fire carbon emissions) are used to compare model results with sediment-based charcoal reconstructions and several approaches of model output processing are tested. Charcoal data are reported in Z-scores and have been used for the period 8000 to 200 BP to exclude the post-Industrial period of strong anthropogenic forcing during the last two centuries. The model-data comparison reveals a robust correspondence in fire trends for most regions considered, while few regions, such as Europe, display different trends between simulated and observed trends. The difference between the modelled and observed fire activity could be linked to an absence of the anthropogenic forcing (e.g., human ignitions and suppression) in the model simulations, but also related to limitations of model assumptions for modelling fire dynamics. For the model trends, the usage of spatial averaging or Z-score processing of model output resulted in similar directions of trend. However, modelled Z-scores resulted in higher rank correlations with the charcoal Z-scores in most of the regions. Therefore, while both metrics are useful, the Z-score processing is more preferable for the modelled fire comparison with the charcoal records than the areal averaging.
An orthogonal curvilinear terrain-following coordinate for atmospheric models
Authors: Li Y. , Wang B. , Wang D.
Published: November 2013

Abstract. We have designed an orthogonal curvilinear terrain-following coordinate (the orthogonal σ coordinate, or the OS coordinate) to overcome two well-known problems in the classic σ coordinate, namely, pressure gradient force (PGF) errors and advection errors. First, in the design of basis vectors, we rotate the basis vectors of the z coordinate in a particular way in order to reduce the PGF errors and add a special rotation parameter b to each rotation angel in order to reduce the advection errors. Second, the corresponding definition of each OS coordinate is solved through its basis vectors. Third, the scalar equations of the OS coordinate are solved by expanding the vector equation using the basis vectors. Since the computational form of PGF has only one term in each momentum equation of the OS coordinate, the PGF errors will be significantly reduced, according to Li et al. (2012). When a proper b is chosen, the σ levels over a steep terrain can be significantly smoothed, therefore alleviating the advection errors in the OS coordinate. This is demonstrated by a series of 2-D linear advection experiments under a unified framework.
Development of a new semi-empirical parameterization for below-cloud scavenging of size-resolved aerosol particles by both rain and snow
Authors: Wang X. , Zhang L. , Moran M. D.
Published: November 2013

Abstract. A parameter called the scavenging coefficient Λ is widely used in aerosol chemical transport models (CTMs) to describe below-cloud scavenging of aerosol particles by rain and snow. However, uncertainties associated with available size-resolved theoretical formulations for Λ span one to two orders of magnitude for rain scavenging and nearly three orders of magnitude for snow scavenging. Two recent reviews of below-cloud scavenging of size-resolved particles recommended that the upper range of the available theoretical formulations for Λ should be used in CTMs based on uncertainty analyses and comparison with limited field experiments. Following this recommended approach, a new semi-empirical parameterization for size-resolved Λ has been developed for below-cloud scavenging of atmospheric aerosol particles by both rain (Λrain) and snow (Λsnow). The new parameterization is based on the 90th percentile of Λ values from an ensemble data set containing calculated using all possible "realizations" of available theoretical Λ formulas and covering a large range of aerosol particle sizes and precipitation intensities (R). For any aerosol particle size of diameter d, a strong linear relationship between the 90th-percentile log10(Λ) and log10(R), which is equivalent to a power-law relationship between Λ and R, is identified. The log-linear relationship, which is characterized by two parameters (slope and y-intercept), is then further parameterized by fitting these two parameters as polynomial functions of aerosol size d. A comparison of the new parameterization with limited measurements in the literature in terms of the magnitude of Λ and the relative magnitudes of Λrain and Λsnow suggests that it is a reasonable approximation. Advantages of this new semi-empirical parameterization compared to traditional theoretical formulations for Λ include its applicability to below-cloud scavenging by both rain and snow over a wide range of particle sizes and precipitation intensities, ease of implementation in any CTM with a representation of size-distributed particulate matter, and a known representativeness based on the consideration in its development of all available theoretical formulations and field-derived estimates for Λ(d) and their associated uncertainties.
CISG and Arbitration Clauses: Issues of Intent and Validity
Authors: Vorobey Dmytro V.
Published: November 2013

CISG and Arbitration Clauses: Issues of Intent and Validity
FORUM SHOPPING AND THE COST OF ACCESS TO JUSTICE: COST AND CERTAINTY IN INTERNATIONAL COMMERCIAL LITIGATION AND ARBITRATION
Authors: Assareh Ali
Published: November 2013

FORUM SHOPPING AND THE COST OF ACCESS TO JUSTICE COST AND CERTAINTY IN INTERNATIONAL COMMERCIAL LITIGATION AND ARBITRATION
BIG AND SMALL FISH IN THE SEA OF PATENT LITIGATION: AN ANALYSIS OF THE AMP v. USPTO DECISION AND ITS EFFECT ON LARGE AND SMALL BUSINESSES
Authors: Hershey Kevin
Published: November 2013

BIG AND SMALL FISH IN THE SEA OF PATENT LITIGATION: AN ANALYSIS OF THE AMP v. USPTO DECISION AND ITS EFFECT ON LARGE AND SMALL BUSINESSES
Presentación Vol.32
Authors: Editora La
Published: November 2013

DOI: http://dx.doi.org/10.5377/lrd.v32i0.1248 Revista de Derecho, Vol. 32, Nº 1, Año 2011
Separation and Determination of Copper in Bottled Water Samples by Combination of Dispersive Liquid–Liquid Microextraction and Microsample Introduction Flame Atomic Absorption Spectrometry
Authors: Citak Demirhan , Tuzen Mustafa
Published: November 2013

A new and simple method for the determination of trace amounts of Cu(II) was developed by combination of dispersive liquid–liquid microextraction (DLLME) preconcentration and microsample introduction flame atomic absorption spectrometry. In this method, ethanol and chloroform were chosen as disperser and extraction solvents, respectively, and 1-nitroso-2-naphthol was used as the complexing agent. The factors affecting the extraction efficiency and determination of Cu(II), including extraction and disperser solvent nature and volume, concentration of the complexing agent, pH of the solution, extraction time, and matrix ions, were investigated. Under optimal conditions, the LOD for Cu(II) was 0.95 μg/L with a preconcentration factor of 70. The RSD was 1.9%. The accuracy of the developed DLLME method was verified by determination of Cu(II) in a certified reference material (NRCC-SLRS-4 river water). The relative error was –3.31%. The developed preconcentration procedure was successfully applied to the analysis of bottled drinking water samples.
Hierarchical Cluster Analysis of Matrix Effects on 110 Pesticide Residues in 28 Tea Matrixes
Authors: Li Yan , Pang Guo-Fang , Fan Chun-Lin , Chen Xi
Published: November 2013

Matrix effects on 110 pesticides in 28 tea matrixes of different varieties and origins by LC/MS/MS were studied, and most of the pesticides exhibited soft and medium signal suppression. To better understand the influence of the tea varieties and the physicochemical characteristics of pesticides on the matrix effects, the multivariate analysis tool called hierarchical cluster analysis was applied. Tea matrixes were grouped into three clusters: unfermented, fermented, and post-fermented teas. Any type of tea can be chosen from each cluster as a corresponding representative matrix within that cluster to make matrix-matched solutions, which could simplify analysis while guaranteeing its accuracy. Matrix effects on most pesticides were similar despite the physicochemical diversities of the pesticides.
Analytical Method and Interlaboratory Study for the Quantitation of Aminocyclopyrachlor Residues in Vegetation by Liquid Chromatography/Tandem Mass Spectrometry
Authors: Nanita Sergio C , Stewart Dustin J , Rodgers Carol A , Tesfai Elen , Schwarz Timo , Robaugh Erin C , Henze Robert M , Pentz Anne M , Moate Thomas , Vogl Emily , Weintraub Randy , Robaugh David , Krening Amanda , Hidalgo Edison , Class Thomas , Reibach Paul , McLachlan Tracy , Lowrie Christopher
Published: November 2013

The quick, easy, cheap, effective, rugged, and safe (QuEChERS) and the U. S. Food and Drug Administration pesticide multiresidue methods were systematically tested for the analysis of aminocyclopyrachlor, a new synthetic auxin herbicide. Results revealed that these procedures are not suitable, highlighting the need for a publicly available residue method for this new active ingredient. Such a method has been developed and is reported herein for aminocyclopyrachlor residue analysis in vegetation, including white pine, Norway spruce, grass forage, and grass hay. Aminocyclopyrachlor residues were purified from plant tissue extracts by filtration through SPE cartridges with strong anion exchange stationary phases and analyzed using LC/MS/MS. This method was validated at five laboratories across the United States; their results were compared to evaluate reproducibility and ruggedness. The method LOQ was 0.01 mg/kg (ppm) and the LOD 0.003 mg/kg (ppm) for the matrixes tested. A qualitative procedure to confirm the molecular identity of residues based on retention time measurements and ion transition peak area ratios (m/z 214 → 68/m/z 214 → 101) is also presented.
One-Step Simultaneous Differential Scanning Calorimetry-FTIR Microspectroscopy to Quickly Detect Continuous Pathways in the Solid-State Glucose/Asparagine Maillard Reaction
Authors: Hwang Deng-Fwu , Hsieh Tzu-Feng , Lin Shan-Yang
Published: November 2013

The stepwise reaction pathway of the solid-state Maillard reaction between glucose (Glc) and asparagine (Asn) was investigated using simultaneous differential scanning calorimetry (DSC)-FTIR microspectroscopy. The color change and FTIR spectra of Glc-Asn physical mixtures (molar ratio = 1:1) preheated to different temperatures followed by cooling were also examined. The successive reaction products such as Schiff base intermediate, Amadori product, and decarboxylated Amadori product in the solid-state Glc-Asn Maillard reaction were first simultaneously evidenced by this unique DSC-FTIR microspectroscopy. The color changed from white to yellow-brown to dark brown, and appearance of new IR peaks confirmed the formation of Maillard reaction products. The present study clearly indicates that this unique DSC-FTIR technique not only accelerates but also detects precursors and products of the Maillard reaction in real time.
Evaluation of 3M™ Molecular Detection Assay (MDA) Salmonella for the Detection of Salmonella in Selected Foods: Collaborative Study
Authors: Bird Patrick , Fisher Kiel , Boyle Megan , Huffman Travis , Benzinger, Jr M Joseph , Bedinghaus Paige , Flannery Jonathan , Crowley Erin , Agin James , Goins David , Benesh DeAnn , David John ,   Collaborators:, Awad D , Bandu M , Blanchard K , Bosco D , Brooks R , Clark D , Dammann H , Dyszel J , Gill V , Greenwell M , Gwinn C , Horan M , Jurgens J , Kelly M , Lewis D , Luce S , Marchent J , McMahon W , Mello I , Montez S , Moosekian S , Morey A , Newman K , Oltman M , Ontiberos M , Rajkowski K , Ruebl J , Stawick B , Thompson L , Vross M
Published: November 2013

The 3M™ Molecular Detection Assay (MDA) Salmonella is used with the 3M™ Molecular Detection System for the detection of Salmonella spp. in food, food-related, and environmental samples after enrichment. The assay utilizes loop-mediated isothermal amplification to rapidly amplify Salmonella target DNA with high specificity and sensitivity, combined with bioluminescence to detect the amplification. The 3M MDA Salmonella method was compared using an unpaired study design in a multilaboratory collaborative study to the U. S. Department of Agriculture/Food Safety and Inspection Service-Microbiology Laboratory Guidebook (USDA/FSIS-MLG 4.05), Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg and Catfish Products for raw ground beef and the U.S. Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) Chapter 5 Salmonella reference method for wet dog food following the current AOAC guidelines. A total of 20 laboratories participated. For the 3M MDA Salmonella method, raw ground beef was analyzed using 25 g test portions, and wet dog food was analyzed using 375 g test portions. For the reference methods, 25 g test portions of each matrix were analyzed. Each matrix was artificially contaminated with Salmonella at three inoculation levels: an uninoculated control level (0 CFU/test portion), a low inoculum level (0.2–2 CFU/test portion), and a high inoculum level (2–5 CFU/test portion). In this study, 1512 unpaired replicate samples were analyzed. Statistical analysis was conducted according to the probability of detection (POD). For the low-level raw ground beef test portions, the following dLPOD (difference between the POD of the reference and candidate method) values with 95% confidence intervals were obtained: –0.01 (–0.14, +0.12). For the low-level wet dog food test portions, the following dLPOD with 95% confidence intervals were obtained: –0.04 (–0.16, +0.09). No significant differences were observed in the number of positive samples detected by the 3M MDA Salmonella method versus either the USDA/FSIS-MLG or FDA/BAM methods.
Applicability of Preparative Overpressured Layer Chromatography and Direct Bioautography in Search of Antibacterial Chamomile Compounds
Authors: Móricz Ágnes M , Ott Péter G , Alberti Ágnes , Böszörményi Andrea , Lemberkovics Éva , Szőke Éva , Kéry Ágnes , Mincsovics Emil
Published: November 2013

In situ sample preparation and preparative overpressured layer chromatography (OPLC) fractionation on a 0.5 mm thick adsorbent layer of chamomile flower methanol extract prepurified by conventional gravitation accelerated column chromatography were applied in searching for bioactive components. Sample cleanup in situ on the adsorbent layer subsequent to sample application was performed using mobile phase flow in the opposite direction (the input and output of the eluent was exchanged). The antibacterial effect of the fractions obtained from the stepwise gradient OPLC separation with the flow in the normal direction was evaluated by direct bioautography against two Gram-negative bacteria: the luminescence gene tagged plant pathogenic Pseudomonas syringae pv. maculicola, and the naturally luminescent marine bacterium Vibrio fischeri. The fractions having strong activity were analyzed by SPME-GC/MS and HPLC/MS/MS. Mainly essential oil components, coumarins, flavonoids, phenolic acids, and fatty acids were tentatively identified in the fractions.
Unintended Reporting of Misleading Hb A1c Values When Using Assays Incapable of Detecting Hemoglobin Variants
Authors: Rhea Jeanne M. , Koch David , Ritchie James , Singh Harsh V. , Young Andrew N. , Burgess Tom , Molinaro Ross J.
Published: November 2013

Context.—It is recommended that hemoglobin (Hb) A1c (Hb A1c) not be used to assess average glycemia in patients who have altered red blood cell life span.

Objective.—To investigate the frequency of reporting an Hb A1c value for Hb variant samples that do not include Hb A.

Design.—Hb A1c samples (n = 500) were procured and screened for Hb variants that may affect Hb A1c interpretation (Hb SS, Hb SC, and Hb S–β-thalassemia). Five of each of these samples were tested by ion-exchange high-performance liquid chromatography, immunoturbidimetric assay, second-generation immunoturbidimetric assay, and affinity chromatography.

Results.—Eleven (2.2%) homozygous Hb SS, 6 (1.2%) Hb SC, and 5 (1.0%) Hb S–β-thalassemia samples were identified out of the 500 samples tested. Three of 4 instruments investigated in this study are known to not be plagued by analytic interference from these Hb variants but disturbingly reported Hb A1c values in the absence of Hb A.

Conclusions.—The improved analytic specificity of Hb A1c platforms has by and large eliminated interferences from the most common heterozygous Hb variants. A consequence, however, is the potential for unintended reporting of Hb A1c results in the presence of homozygous and compound heterozygous Hb variants that lack Hb A and the inability to distinguish those samples not recommended to be used for patient care. The ability to identify samples harboring Hb variants that preclude the utility of Hb A1c may be beneficial in high prevalence populations.
Réplica ao artigo de Jurandyr L. Ross, "O contexto tectônico e a morfogênese da Província Serrana de Mato Grosso", Rev. IG 12(1/2): 21-37
Authors: Petri Setembrino , Fúlfaro Vicente José
Published: November 2013

o Dr. Ross apresenta interessante trabalho sobre a Província Serrana, divisor de água dos rios Cuiabá e Paraguai, Arinos e Teles Pires. É natural que como geomorfólogo enfatize as interpretações de superfícies erosivas. A discordância, relativa a nossa interpreta- ção de que a Província Serrana poderia ter sido área-fonte tanto da Formação Parecis como Bauru, não se encontra, a nosso ver, suficientemente embasada. O
From GRID to gridlock: the relationship between scientific biomedical breakthroughs and HIV/AIDS policy in the US Congress
Authors: Platt Matthew B , Platt Manu O
Published: November 2013

Introduction

From the travel ban on people living with HIV (PLHIV) to resistance to needle exchange programmes, there are many examples where policy responses to HIV/AIDS in the United States seem divorced from behavioural, public health and sociological evidence. At its root, however, the unknowns about HIV/AIDS lie at biomedical science, and scientific researchers have made tremendous progress over the past 30 years of the epidemic by using antiretroviral therapy to increase the life expectancy of PLHIV almost to the same level as non‐infected individuals; but a relationship between biomedical science discoveries and congressional responses to HIV/AIDS has not been studied. Using quantitative approaches, we directly examine the hypothesis that progress in HIV/AIDS biomedical science discoveries would have a correlative relationship with congressional response to HIV/AIDS from 1981 to 2010.

Methods

This study used original data on every bill introduced, hearing held and law passed by the US Congress relating to HIV/AIDS over 30 years (1981–2010). We combined congressional data with the most cited and impactful biomedical research scientific publications over the same time period as a metric of biomedical science breakthroughs. Correlations between congressional policy and biomedical research were then analyzed at the aggregate and individual levels.

Results

Biomedical research advancements helped shape both the level and content of bill sponsorship on HIV/AIDS, but they had no effect on other stages of the legislative process. Examination of the content of bills and biomedical research indicated that science helped transform HIV/AIDS bill sponsorship from a niche concern of liberal Democrats to a bipartisan coalition when Republicans became the majority party. The trade‐off for that expansion has been an emphasis on the global epidemic to the detriment of domestic policies and programmes.

Conclusions

Breakthroughs in biomedical science did associate with the number and types of HIV/AIDS bills introduced in Congress, but that relationship did not extend to the passage of laws or to hearings. When science matters, it cannot be separated from political considerations. An important implication of our work has been the depoliticizing role that science can play. Scientific breakthroughs helped to transform HIV/AIDS policy from a niche of liberal Democrats into bipartisan support for the global fight against the disease.
Energy balance in a warm world without the ocean conveyor belt and sea ice
Authors: Hu Aixue , Meehl Gerald A. , Han Weiqing , Lu Jianhua , Strand Warren G.
Published: November 2013

Under a strong global warming scenario, the global mean temperature could rise up to 10°C, causing the global ocean conveyor belt to collapse and the summer sea ice to disappear. This will lead to profound changes in our climate system and to impact drastically the living conditions of the globe. Here we study how the global heat redistribution and regional heat balance will respond to these changes using the National Center for Atmospheric Research Community Climate System Model version 4. Results show that the collapsed ocean conveyor belt reduces the oceanic northward meridional heat transport (MHT) by nearly 60% with a minor increase in the atmospheric MHT. The polar amplified warming is primarily caused by the increased absorption of longwave radiation due to the increased greenhouse gases and cloudiness and by the increased absorption of shortwave radiation due to a lower albedo associated with the disappeared summer sea ice.
Recent variability of the tropical tropopause inversion layer
Authors: Wang Wuke , Matthes Katja , Schmidt Torsten , Neef Lisa
Published: November 2013

The recent variability of the tropopause temperature and the tropopause inversion layer (TIL) are investigated with Global Positioning System Radio Occultation data and simulations with the National Center for Atmospheric Research's Whole Atmosphere Community Climate Model (WACCM). Over the past decade (2001–2011) the data show an increase of 0.8 K in the tropopause temperature and a decrease of 0.4 K in the strength of the tropopause inversion layer in the tropics, meaning that the vertical temperature gradient has declined, and therefore that the stability above the tropopause has weakened. WACCM simulations with finer vertical resolution show a more realistic TIL structure and variability. Model simulations show that the increased tropopause temperature and the weaker tropopause inversion layer are related to weakened upwelling in the tropics. Such changes in the thermal structure of the upper troposphere and lower stratosphere may have important implications for climate, such as a possible rise in water vapor in the lower stratosphere.
THEMIS observations of compressional poloidal pulsations in the dawnside magnetosphere: A case study
Authors: Korotova G. I. , Sibeck D. G. , Angelopoulos V. , Walsh B. M.
Published: November 2013

We present results from a case study of compressional poloidal pulsations with periods ranging from 5 to 12 min in the dawn magnetosphere from 1630 to 2000 UT on 27 February 2011. However, we employ THEMIS (Time History of Events and Macroscale Interactions during Substorms) magnetic field, plasma, and energetic particle observations to determine azimuthal wavelengths (7000–27,000 km) and velocities (9–28 km/s) consistent with previous work. We then apply a new method invoking the north to south motion of the THEMIS spacecraft and the fact that the equatorial node exhibited north‐south oscillations to derive the meridional structure of the wave in great detail. We determined that the amplitude of the meridional motion of the equatorial node was ~0.8 RE, and that the meridional wave length exceeded 3 RE.
When is cloud condensation nuclei activity sensitive to particle characteristics at emission?
Authors: Fierce Laura , Riemer Nicole , Bond Tami C.
Published: November 2013

The cloud condensation nuclei (CCN) activity of an aerosol population depends on individual particles' size and composition. However, these properties are modified shortly after emission by condensation of semivolatile substances and coagulation with other particles. It is, therefore, unclear to what extent particle characteristics at emission affect CCN activity after aging by condensation and coagulation. We present a process‐level analysis of particles emitted from a particular source, diesel engines, in which we isolate the separate effects of condensation and coagulation on the CCN activation of primary aerosol. We simulated aerosol dynamics in a polluted area with the Particle Monte Carlo model coupled to the Model for Simulating Aerosol Interactions and Chemistry and evaluated three factors influencing particle CCN activity shortly after emission: (1) particle characteristics at the time of emission, (2) aging conditions near the emission source, and (3) the water vapor supersaturation at which CCN activity is evaluated. CCN concentrations were sensitive to particle properties at emission only under specific environmental conditions. Diesel emissions did not strongly influence local CCN concentrations at low cloud supersaturation thresholds (s<0.2%), regardless of particle characteristics at emission or aging conditions. At higher supersaturation thresholds (s>0.2%) and under conditions of rapid secondary aerosol formation, changes in CCN concentrations showed a greater sensitivity to particles' emission size than composition.
Assessing temporal and spatial variations in atmospheric dust over Saudi Arabia through satellite, radiometric, and station data
Authors: Yu Yan , Notaro Michael , Liu Zhengyu , Kalashnikova Olga , Alkolibi Fahad , Fadda Eyad , Bakhrjy Fawzieh
Published: November 2013

Temporal and spatial variations in atmospheric dust over Saudi Arabia are studied for 2000–2010 using satellite and ground‐based aerosol optical depth (AOD) and station dust storm observations. These data sets show a consistent seasonal cycle in dust activity, which peaks in spring–summer in northern‐central Saudi Arabia and in early spring and summer across southern‐western Saudi Arabia, associated with strong winds and westerly transport, respectively. Over the desert regions, anomalies in dust activity from satellite and station observations are highly correlated on the monthly timescale and statistically consistent on the daily timescale. However, the coastal and mountainous regions exhibit limited consistency between these data sets, likely associated with the coarse spatial resolution and short sampling time in the satellite data, as well as non‐aeolian aerosol contamination. We conclude that satellite AOD is a reliable index for dust activity over desert regions but not over low dust, coastal, and topographically complex regions in Saudi Arabia.
Risk Factors for Early Revision After Total Hip Arthroplasty
Authors: Dy Christopher J. , Bozic Kevin J. , Pan Ting Jung , Wright Timothy M. , Padgett Douglas E. , Lyman Stephen
Published: November 2013

Objective

Revision total hip arthroplasty (THA) is associated with increased cost, morbidity, and technical challenge compared to primary THA. A better understanding of the risk factors for early revision is needed to inform strategies to optimize patient outcomes.

Methods

A total of 207,256 patients who underwent primary THA between 1997–2005 in California and New York were identified from statewide databases. Unique patient identifiers were used to identify early revision THA (<10 years from index procedure). Patient characteristics (demographics, comorbidities, insurance type, and preoperative diagnosis), community characteristics (education level, poverty, and population density), and hospital characteristics (annual THA volume, bed size, and teaching status) were evaluated using multivariable regression to determine risk factors for early revision.

Results

The probabilities of undergoing early aseptic revision and early septic revision were 4% and <1% at 5 years, respectively. Women were 29% less likely than men to undergo early septic revision (P < 0.001). Patients with Medicaid and Medicare were 91% and 24%, respectively, more likely to undergo early septic revision than privately insured patients (P = 0.01 and P < 0.001, respectively). Hospitals performing <200 THAs annually had a 34% increased risk of early aseptic revision compared to hospitals performing >400 THAs annually (P < 0.001).

Conclusion

A number of identifiable factors, including younger age, Medicaid, and low hospital volume, increase the risk of undergoing early revision THA. Patient‐level characteristics distinctly affect the risk of revision within 10 years, particularly if due to infection. Our findings reinforce the need for continued investigation of the predictors of early failure following THA.
First Ray Kinematics in Women With Rheumatoid Arthritis and Bunion Deformity: A Gait Simulation Imaging Study
Authors: Glasoe Ward M. , Jensen Daniel D. , Kampa Brian B. , Karg Lara K. , Krych Angela R. , Pena Fernando A. , Ludewig Paula M.
Published: November 2013

Objective

The first ray plays a role in the development of bunion foot deformity, but for unknown reasons. This prospective, cross‐sectional study investigated first ray kinematics in women with rheumatoid arthritis (RA) and bunion.

Methods

Nine participants having RA‐bunion were analyzed in comparison to a control group (n = 10). Data were acquired using a magnetic resonance scanner. Conditions were standardized to simulate gait midstance, heel off, and terminal stance. Foot posture (hallux angle, intermetatarsal angle, arch angle, and calcaneus angle) and relative first ray position angles/helical axis parameters registered across gait conditions were measured. An analysis of variance model compared data between groups and across conditions, and correlation assessed the relationship between selected variables.

Results

Eversion of the calcaneus averaged 9°, and adduction of the first ray was increased (F = 6.29, P = 0.02) by ≥4.6° across conditions in the RA‐bunion group. There was an interaction (F = 7.73, P = 0.01) for the first ray axis. Followup comparisons identified increased inclination of the first ray axis over middle stance compared to late stance in the group with RA and bunion. There was moderate correlation (r = −0.42) between the calcaneus angle of eversion and inclination of the first ray axis.

Conclusion

Optimal treatment for bunion has not been defined. This research identified calcaneus eversion and first ray adduction, as well as inclination of the first ray axis as risk factors of bunion. This result may inform the evaluation and treatment of bunion in women with RA.
Highly Conductive Ordered Mesoporous Carbon Based Electrodes Decorated by 3D Graphene and 1D Silver Nanowire for Flexible Supercapacitor
Authors: Zhi Jian , Zhao Wei , Liu Xiangye , Chen Angran , Liu Zhanqiang , Huang Fuqiang
Published: November 2013

Ordered mesoporous carbon (OMC) is considered one of the most promising materials for electric double layer capacitors (EDLC) given its low‐cost, high specific surface area, and easily accessed ordered pore channels. However, pristine OMC electrode suffers from poor electrical conductivity and mechanical flexibility, whose specific capacitance and cycling stability is unsatisfactory in flexible devices. In this work, OMC is coated on the surface of highly conductive three‐dimensional graphene foam, serving as both charge collector and flexible substrate. Upon further decoration with silver nanowires (Ag NWs), the novel architecture of Ag NWs/3D‐graphene foam/OMC (Ag‐GF‐OMC) exhibits exceptional electrical conductivity (up to 762 S cm−1) and mechanical robustness. The Ag‐GF‐OMC electrodes in flexible supercapacitors reach a specific capacitance as high as 213 F g−1, a value five‐fold higher than that of the pristine OMC electrode. Moreover, these flexible electrodes also exhibit excellent long‐term stability with >90% capacitance retention over 10 000 cycles, as well as high energy and power density (4.5 Wh kg−1 and 5040 W kg−1, respectively). This study provides a new procedure to enhance the device performance of OMC based supercapacitors, which is a promising candidate for the application of flexible energy storage devices.
Solution‐Processed Small‐Molecule Bulk Heterojunction Ambipolar Transistors
Authors: Cheng Shiau‐Shin , Huang Peng‐Yi , Ramesh Mohan , Chang Hsiu‐Chieh , Chen Li‐Ming , Yeh Chia‐Ming , Fung Chun‐Lin , Wu Meng‐Chyi , Liu Chung‐Chi , Kim Choongik , Lin Hong‐Cheu , Chen Ming‐Chou , Chu Chih‐Wei
Published: November 2013

Solution‐processed small‐molecule bulk heterojunction (BHJ) ambipolar organic thin‐film transistors are fabricated based on a combination of [2‐phenylbenzo[d,d']thieno[3,2‐b;4,5‐b']dithiophene (P‐BTDT) : 2‐(4‐n‐octylphenyl)benzo[d,d']thieno[3,2‐b;4,5‐b']dithiophene (OP‐BTDT)] and C60. Treating high electrical performance vacuum‐deposited P‐BTDT organic semiconductors with a newly developed solution‐processed organic semiconductor material, OP‐BTDT, in an optimized ratio yields a solution‐processed p‐channel organic semiconductor blend with carrier mobility as high as 0.65 cm2 V−1 s−1. An optimized blending of P‐BTDT:OP‐BTDT with the n‐channel semiconductor, C60, results in a BHJ ambipolar transistor with balanced carrier mobilities for holes and electrons of 0.03 and 0.02 cm2 V−1 s−1, respectively. Furthermore, a complementary‐like inverter composed of two ambipolar thin‐film transistors is demonstrated, which achieves a gain of 115.
ZnO Nanorods with Broadband Antireflective Properties for Improved Light Management in Silicon Thin‐Film Solar Cells
Authors: Nowak Regina‐Elisabeth , Vehse Martin , Sergeev Oleg , Voss Tobias , Seyfried Moritz , von Maydell Karsten , Agert Carsten
Published: November 2013

Zinc oxide nanorod structures constitute a promising concept to improve light management in photovoltaic devices. This paper reports on the antireflective properties of zinc oxide nanorod arrays in hydrogenated amorphous silicon thin‐film solar cells. Arrays with different structure sizes, grown by electrochemical deposition on aluminum doped zinc oxide seed layers with different thicknesses (400 nm, 800 nm, 1200 nm), are compared. The results show a reduction in the average weighted cell reflectivity by up to 6.1%, as well as enhanced quantum efficiencies and short circuit current densities for all nanorod cells. Optical simulations, describing the nanorod arrays as an effective medium, show that refractive index grading is the main antireflective effect. The improved optical properties result in enhanced power‐conversion efficiencies, demonstrating the feasibility of the nanorod concept for different seed layer thickness and array structure sizes.
Tetraethylammonium Bromide‐Catalyzed Oxidative Thioesterification of Aldehydes and Alcohols
Authors: Zhu Xuebin , Shi Yan , Mao Haibin , Cheng Yixiang , Zhu Chengjian
Published: November 2013

A metal‐free, tetraethylammonium bromide‐catalyzed oxidative coupling of aldehydes or alcohols with thiophenols or disulfides has been developed. This protocol affords an efficient and inexpensive approach to the synthesis of a wide range of thioesters in high yields.

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Iron Chloride‐Catalyzed Three‐Component Domino Sequences: Syntheses of Functionalized α‐Oxy‐N‐acylhemiaminals and α‐Oxyimides
Authors: Drouet Fleur , Zhu Jieping , Masson Géraldine
Published: November 2013

The iron(III) chloride‐multicatalyzed dioxygenation of enamides with TEMPO in the presence of alcohols has been developed. This multicomponent domino process affords efficient new strategies for the synthesis of α‐oxy‐N‐acylhemiaminals or α‐oxyimides in good to excellent yields under mild conditions.

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Transport characteristics and transporter‐based drug–drug interactions of TM‐25659, a novel TAZ modulator
Authors: Choi Min‐Koo , Kwon Mihwa , Ahn Jin Hee , Kim Nak Jung , Bae Myung‐Ae , Song Im‐Sook
Published: November 2013

The in vitro metabolic stability and transport mechanism of TM‐25659, a novel TAZ modulator, was investigated in human hepatocytes and human liver microsomes (HLMs) based on the preferred hepatobiliary elimination in rats. In addition, the in vitro transport mechanism and transporter‐mediated drug–drug interactions were evaluated using oocytes and MDCKII cells overexpressing clinically important drug transporters. After a 1 h incubation in HLMs, 92.9 ± 9.5% and 95.5 ± 11.6% of the initial TM‐25659 remained in the presence of NADPH and UDPGA, respectively. Uptake of TM‐25659 readily accumulated in human hepatocytes at 37 ºC (i.e. 6.7‐fold greater than that at 4 ºC), in which drug transporters such as OATP1B1 and OATP1B3 were involved. TM‐25659 had a significantly greater basal to apical transport rate (5.9‐fold) than apical to basal transport rate in the Caco‐2 cell monolayer, suggesting the involvement of an efflux transport system. Further studies using inhibitors of efflux transporters and overexpressing cells revealed that MRP2 was involved in the transport of TM‐25659. These results, taken together, suggested that TM‐25659 can be actively influxed into hepatocytes and undergo biliary excretion without substantial metabolism. Additionally, TM‐25659 inhibited the transport activities of OATP1B1 and OATP1B3 with IC50 values of 36.3 and 25.9 μm, respectively. TM‐25659 (100 μm) increased the accumulation of the probe substrate by 160% and 213%, respectively, through the inhibition of efflux function of P‐gp and MRP2. In conclusion, OATP1B1, OATP1B3, P‐gp and MRP2 might be major transporters responsible for the pharmacokinetics and drug–drug interaction of TM‐25659, although their contribution to in vivo pharmacokinetics needs to be further investigated. Copyright © 2013 John Wiley & Sons, Ltd.
Real‐time monitoring and control of soluble signaling factors enables enhanced progenitor cell outputs from human cord blood stem cell cultures
Authors: Csaszar Elizabeth , Chen Kun , Caldwell Julia , Chan Warren , Zandstra Peter W.
Published: November 2013

Monitoring and control of primary cell cultures is challenging as they are heterogenous and dynamically complex systems. Feedback signaling proteins produced from off‐target cell populations can accumulate, inhibiting the production of the desired cell populations. Although culture strategies have been developed to reduce feedback inhibition, they are typically optimized for a narrow range of process parameters and do not allow for a dynamically regulated response. Here we describe the development of a microbead‐based process control system for the monitoring and control of endogenously produced signaling factors. This system uses quantum dot barcoded microbeads to assay endogenously produced signaling proteins in the culture media, allowing for the dynamic manipulation of protein concentrations. This monitoring system was incorporated into a fed‐batch bioreactor to regulate the accumulation of TGF‐β1 in an umbilical cord blood cell expansion system. By maintaining the concentration of TGF‐β1 below an upper threshold throughout the culture, we demonstrate enhanced ex vivo expansion of hematopoietic progenitor cells at higher input cell densities and over longer culture periods. This study demonstrates the potential of a fully automated and integrated real‐time control strategy in stem cell culture systems, and provides a powerful strategy to achieve highly regulated and intensified in vitro cell manufacturing systems. Biotechnol. Bioeng. 2014;111: 1258–1264. © 2013 The Authors Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.
Variations of coronary hemodynamic responses to intravenous adenosine infusion: Implications for fractional flow reserve measurements
Authors: Seto Arnold H. , Tehrani David M. , Bharmal Murtaza I. , Kern Morton J.
Published: November 2013

Background

Continuous intravenous adenosine infusion reportedly produces stable and maximal hyperemia to allow for fractional flow reserve (FFR) measurement; however, several observers have noted variation of the coronary/aortic (Pd/Pa) pressure ratio during the course of an adenosine infusion.

Methods

Pd/Pa pressure recordings during continuous peripheral intravenous adenosine infusion were examined in 51 patients (68 measurements) with data collected for at least 150 sec and for at least 30 sec after the lowest Pd/Pa reading. The lowest recorded Pd/Pa ratio was used as the true FFR value at maximal hyperemia. The highest subsequent Pd/Pa during the remaining period of adenosine infusion was recorded. A separate cohort of 12 patients had Pd/Pa values measured with both peripheral and central infusion.

Results

The average FFR value was 0.82 ± 0.10 and was recorded 99 ± 33 sec into the infusion. The Pd/Pa value showed a subsequent average increase of 0.08 ± 0.07 at 135 ± 32 sec. From the lowest measurement, Pd/Pa changed from a ratio ≤0.80 to >0.80 in 28% of recordings. In the cohort with matched recordings, central infusion reduced the severity (mean change of 0.08 vs. 0.11, P = 0.09) but not the incidence of Pd/Pa variability compared with peripheral infusion.

Conclusion

Instability of Pd/Pa measurements is common over the course of a continuous intravenous adenosine infusion. FFR remains valid as the lowest value of Pd/Pa observed, however, Pd/Pa variability may subsequently occur and complicate pullback measurements for serial or multiple lesions. © 2013 Wiley Periodicals, Inc.
Inhibition of Hypoxia‐Induced Gene Transcription by Substituted Pyrazolyl Oxadiazoles: Initial Lead Generation and Structure–Activity Relationships
Authors: Härter Michael , Thierauch Karl‐Heinz , Boyer Stephen , Bhargava Ajay , Ellinghaus Peter , Beck Hartmut , Greschat‐Schade Susanne , Hess‐Stumpp Holger , Unterschemmann Kerstin
Published: November 2013

The transcription factors hypoxia‐inducible factor‐1 and ‐2 (HIF‐1 and HIF‐2) orchestrate a multitude of processes that allow tumor cells to survive under conditions of low oxygen and nutrients, and that lead to resistance to some apoptotic pathways and facilitate invasion and metastasis. Therefore, inhibition of transactivation by HIF has become an attractive target in cancer research. Herein we present the results of a cell‐based screening approach that led to the discovery of substituted 1H‐pyrazole‐3‐carboxamides. Chemical optimization of the hit class with respect to potency and metabolic stability is described; it resulted in novel 5‐(1H‐pyrazol‐3‐yl)‐1,2,4‐oxadiazoles that inhibit the hypoxia‐induced accumulation of HIF‐1α and HIF‐2α. The HIF inhibitory potency in the screening cell system was improved from IC50 190 to 0.7 nM, and significant parts of the SAR are disclosed. For a key compound, the ability to suppress the hypoxia‐induced expression of HIF target genes was studied in A549 human lung adenocarcinoma cells. The same compound shows a favorable pharmacokinetic profile in rats after i.v. and p.o. administration.