bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arsenic Speciation and Fucoxanthin Analysis from Seaweed Dietary Supplements Using LC-MS
Authors: Avula Bharathi , Wang Yan-Hong , Khan Ikhlas A 
Published: April 2015

Abstract
The study involves the analysis of total arsenic (As) in metallic form, and organic and inorganic As species from seaweeds and dietary supplements. The analysis provides data for dietary exposure estimatesof inorganic species that are considered more toxic to humans than organic and total As. Total As was determined by acid digestion followed by inductively coupled plasma (ICP)-MS. To characterize the As species, solvent extraction with sonication and microwaveextraction using various aqueous and aqueous/organicsolvent mixtures were initially evaluated. The optimum As speciation method was determined to be water extraction followed by anion exchange HPLC coupled with ICP-MS. Optimization of chromatographic conditions led to baseline separation for six As species, including As acid, arsenous acid, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, and arsenocholine, in approximately 8 min using gradient elution. Detection limits for all six compounds were in therange of 10–15 ng/mL. The data presented herewill be valuable for the QA of analytical method development and surveys of total As and As species indietary supplements. The most abundant As species found were arsenite [As(III)] and arsenate [As(V)]. The sum of inorganic As species present in the dietary supplements ranged from 1.2 to 31 μg/day. In addition, the dietary supplements purported to contain fucoxanthin, a carotenoid having pharmacological activities, were analyzed using ultra-performance LC-UV/MS.
HPTLC with Fluorescence Densitometry for Simultaneous Determination of Some Angiotensin II Receptor Blockers in Tablets and Plasma
Authors: Hussein Samiha Abd El-Rahman , El-Wadood Hanaa Mohamed Abd , Abdallah Mohamed Abou-El Wafa , Khorshed A Abd El-Hamid 
Published: April 2015

Abstract
A selective, accurate, precise, and highly sensitive HPTLC assay with reflectance/fluorescence densitometry was developed to separate and quantify some angiotensin II receptor blockers (ARBs), namely, losartan potassium, irbesartan, valsartan, and olmesartan medoxomil, in tablets and plasma. Separation of the target ARBs was performed on precoated silica gel HPTLC plates developed using chloroform–glacial acetic acid (7.5 + 2.5, v/v) mobile phase. The drugs were adequately resolved. After the exposure of the chromatograms to concentrated hydrochloric acid vapor for 10 min, the scanner was set in the reflectance/fluorescence mode with 255 nm excitation wavelength and &gt;400 nm emission filter. The linear regression analysis data for the calibration curves of all studied drugs produced a good linear relationshipwith correlation coefficients ranging from 0.9991 to0.9999 over the concentration range of 2–20 ng/band. LOD and LOQ values of all studied drugs ranged from 0.6 to 0.8 and from 1.7 to 2.4 ng/band, respectively. The developed method was successfully applied for analysis of the target ARBs in tablets and spiked human plasma samples with good precision and accuracy.
Chlorogenic Acid Stability in Pressurized Liquid Extraction Conditions
Authors: Wianowska Dorota , Typek Rafał , Dawidowicz Andrzej L 
Published: April 2015

Abstract
Chlorogenic acids (CQAs) are phenolic compounds naturally occurring in all higher plants. They are potentially useful in pharmaceuticals, foodstuffs, food additives, and cosmetics due to their recently suggested biomedical activity. Hence, research interestin CQA properties, their isomers, and natural occurrence has been growing. Pressurized liquid extraction(PLE) is regarded as an effective and quick sample preparation method in plant analysis. The short time of PLE decreases the risk of chemical degradation ofextracted compounds, thus increasing the attractiveness of its application. However, PLE applied for plant sample preparation is not free from limitations. We found that trans-5-O-caffeoylquinic acid (trans-5-CQA), the main CQA isomer, isomerizes to 3- and 4-O-caffeoylquinic acids and undergoes transesterification, hydrolysis, and reaction with water even in rapid PLE. Moreover, the number and concentration of trans-5-CQA derivatives formed in PLE strongly depends on extractant composition, its pH, and extraction time and temperature. It was not possible to find the PLE conditions in which the transformation process of trans-5-CQA would be eliminated.
Vivione Bioscience RAPID-B®E. coli O157 Test Kit and non-O157 STEC Test Kit Evaluation
Authors: Miller Melinda , Ramsaroop Shawn , Lopez Chris , Brahmanda Bharath 
Published: April 2015

Abstract
RAPID-B® is a high performance, integrated microbiology/infectious disease diagnostic system. The system uses hardware and software that are specifically designed for optimal detection using custom, immuno-based reagents designed to react to cell surface antigens of the target bacteria. The Vivione Bioscience RAPID-B Escherichia coli O157 and non-O157 Shiga toxin-producing E. coli (STEC) kits were validated alongside the U.S. Department of Agriculture, Food Safety and Inspection Service (FSIS), Microbiology Laboratory Guidebook (MLG) 5.07 (for E. coli O157) and FSIS MLG 5B.04 (fornon-O157 STEC) reference methods for the detection of E. coli O157 and STEC. The matrixes, ground beef and beef trim, were inoculated with appropriate CFU/test portion of E. coli O157 and STEC so as to generate fractional positives results, 5 to 15 positives out of 20 inoculated samples. Samples were enriched in prewarmed Brain Heart Infusion broth at 42 ± 1°C for 6.5–7.5 h or 8.5–9.5 h depending on thesample size. All samples were confirmed using the MLG reference method, regardless of initial screen result. The RAPID-B test methods were statistically equivalent to the reference method for the detection ofE. coli O157 and STEC in all testedsamples. Inclusivity and exclusivity testing of the RAPID-B methods showed 100% specificity for both kits. Finally, the RAPID-B test methods were shown to be robust when variations were applied to enrichment time, broth temperature, and vortexing time.
Rapid Visual Detection of Eight Meat Species Using Optical Thin-Film Biosensor Chips
Authors: Wang Wei , Zhu Yepei , Chen Ying , Xu Xinglian , Zhou Guanghong 
Published: April 2015

Abstract
Adulteration of meat products has become a very serious issue nowadays. To protect consumer rights, food labeling is required in many countries, and efficient and accurate detection methods are essential as well. This paper reports an innovative method for the rapid detection and identification of meat species based on a silicon-based optical thin-film biosensor chip with which color change results can be perceived by the naked eye without any expensive instruments. This biosensor system can simultaneously and specifically detect eight meat species, including deer, rabbit, duck, chicken, beef, horse, sheep, and pork. The absolute detection limit of this method was 0.5 pg of deer/beef DNA, and the practical detectionlimit was 0.001%. The biosensor detection can be completed within 30 min after PCR amplification. Therefore, this assay permits specific, sensitive, rapid, and simple detection of meat species in raw or cooked meat products.
Characterization and Quantitation of Yohimbine and Its Analogs in Botanicals and Dietary Supplements Using LC/QTOF-MS and LC/QQQ-MS for Determination of the Presence of Bark Extract and Yohimbine Adulteration
Authors: Lucas Derick , Neal-Kababick James , Zweigenbaum Jerry 
Published: April 2015

Abstract
The compound yohimbine HCl has been restricted in Australia and categorized as a scheduled prescription drug in other parts of the world, including the United States where it is monographed as a drug in the U. S. Pharmacopeia. However, the bark of the yohimbe plant and its extract is considered a botanical that can be used as a dietarysupplement in some partsof the world. For these reasons, methods to characterize the indole alkaloids of the bark and quantify yohimbine and its analogs are presented using accurate mass LC/quadrupole time-of-flight (QTOF)-MS and triple quadrupole LC/MS, respectively. Samples were extracted with a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method to characterize and quantify the indole alkaloids. With the LC/QTOF-MS in auto MS/MS mode the indole alkaloids were identified,and the isomeric response of each could be used to determine whether the actual bark or extract was in samples of dietary supplements and not adulteration with yohimbine HCl. Analogs were identified and include yohimbic acid, methyl yohimbine, and hydroxyl yohimbine. Many isomers of each were also detected, butidentified only by the number of chromatographic peaks. Quantification of yohimbine and ajmalicine spiked extracts showed recoveries of 99 to 103% with RSD of 3.6% or lower and LODs of less than 100 ppt. Calibration of the two standards gave r2 = 0.9999 in a range from 0.1 to 100 ppb. Dietary supplements quantified for these two compounds showed a range from not detected to 3x the amounts found in thebark.
Ion distributions in the Earth's foreshock: Hybrid‐Vlasov simulation and THEMIS observations
Authors: Kempf Yann , Pokhotelov Dimitry , Gutynska Olga , Wilson III Lynn B. , Walsh Brian M. , Alfthan Sebastian von , Hannuksela Otto , Sibeck David G. , Palmroth Minna 
Published: April 2015

AbstractWe present the ion distribution functions in the ion foreshock upstream of the terrestrial bow shock obtained with Vlasiator, a new hybrid‐Vlasov simulation geared toward large‐scale simulations of the Earth's magnetosphere (http://vlasiator.fmi.fi). They are compared with the distribution functions measured by the multispacecraft Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission. The known types of ion distributions in the foreshock are well reproduced by the hybrid‐Vlasov model. We show that Vlasiator reproduces the decrease of the backstreaming beam speed with increasing distance from the foreshock edge, as well as the beam speed increase and density decrease with increasing radial distance from the bow shock, which have been reported before and are visible in the THEMIS data presented here. We also discuss the process by which wave‐particle interactions cause intermediate foreshock distributions to lose their gyrotropy. This paper demonstrates the strength of the hybrid‐Vlasov approach which lies in producing uniformly sampled ion distribution functions with good resolution in velocity space, at every spatial grid point of the simulation and at any instant. The limitations of the hybrid‐Vlasov approach are also discussed.
What frequencies of standing surface waves can the subsolar magnetopause support?
Authors: Archer M. O. , Plaschke F. 
Published: April 2015

AbstractIt is has been proposed that the subsolar magnetopause may support its own eigenmode, consisting of propagating surface waves which reflect at the northern/southern ionospheres forming a standing wave. While the eigenfrequencies of these so‐called Kruskal‐Schwarzschild (KS) modes have been estimated under typical conditions, the potential distribution of frequencies over the full range of solar wind conditions is not known. Using models of the magnetosphere and magnetosheath applied to an entire solar cycle's worth of solar wind data, we perform time‐of‐flight calculations yielding a database of KS mode frequencies. Under nonstorm times or northward interplanetary magnetic field (IMF), the most likely fundamental frequency is calculated to be  mHz, consistent with previous estimates and indirect observational evidence for such standing surface waves of the subsolar magnetopause. However, the distributions exhibit significant spread (of order ±0.3 mHz) demonstrating that KS mode frequencies, especially higher harmonics, should vary considerably depending on the solar wind conditions. The implications of such large spread on observational statistics are discussed. The subsolar magnetopause eigenfrequencies are found to be most dependent on the solar wind speed, southward component of the IMF, and the Dst index, with the latter two being due to the erosion of the magnetosphere by reconnection and the former an effect of the expression for the surface wave phase speed. Finally, the possible occurrence of KS modes is shown to be controlled by the dipole tilt angle.
Overview and early results of the Global Lightning and Sprite Measurements mission
Authors: Sato M. , Ushio T. , Morimoto T. , Kikuchi M. , Kikuchi H. , Adachi T. , Suzuki M. , Yamazaki A. , Takahashi Y. , Inan U. , Linscott I. , Ishida R. , Sakamoto Y. , Yoshida K. , Hobara Y. , Sano T. , Abe T. , Nakamura M. , Oda H. , Kawasaki Z.‐I. 
Published: April 2015

AbstractGlobal Lightning and Sprite Measurements on Japanese Experiment Module (JEM‐GLIMS) is a space mission to conduct the nadir observations of lightning discharges and transient luminous events (TLEs). The main objectives of this mission are to identify the horizontal distribution of TLEs and to solve the occurrence conditions determining the spatial distribution. JEM‐GLIMS was successfully launched and started continuous nadir observations in 2012. The global distribution of the detected lightning events shows that most of the events occurred over continental regions in the local summer hemisphere. In some events, strong far‐ultraviolet emissions have been simultaneously detected with N2 1P and 2P emissions by the spectrophotometers, which strongly suggest the occurrence of TLEs. Especially, in some of these events, no significant optical emission was measured by the narrowband filter camera, which suggests the occurrence of elves, not sprites. The VLF receiver also succeeded in detecting lightning whistlers, which show clear falling‐tone frequency dispersion. Based on the optical data, the time delay from the detected lightning emission to the whistlers was identified as ∼10 ms, which can be reasonably explained by the wave propagation with the group velocity of whistlers. The VHF interferometer conducted the spaceborne interferometric observations and succeeded in detecting VHF pulses. We observed that the VHF pulses are likely to be excited by the lightning discharge possibly related with in‐cloud discharges and measured with the JEM‐GLIMS optical instruments. Thus, JEM‐GLIMS provides the first full set of optical and electromagnetic data of lightning and TLEs obtained by nadir observations from space.
The relative influence of environmental characteristics on tropical deep convective morphology as observed by CloudSat
Authors: Igel Matthew R. , van den Heever Susan C. 
Published: April 2015

AbstractUtilizing a previously developed CloudSat cloud object database, the sensitivity of oceanic, mature, deep convective cloud morphology to cloud‐scale environmental characteristics is examined. Convective available potential energy (CAPE), aerosol optical depth, midlevel vertical velocity, and tropospheric deep shear are all used to characterize the environment. The sensitivity of various aspects of convective morphology to each one of these environmental quantities is assessed individually. The results demonstrate that clouds tend to be invigorated by higher CAPE, aerosol, and upward midlevel vertical velocity. Stronger shear tends to make clouds wider but also shallower. The relative importance of each of these and some additional environmental measures to trends in cloud morphology are compared. It is found that aerosol, deep‐layer shear, and sea surface temperature tend to be the most influential environmental factors to convective morphology. The results are shown to be insensitive to the manner in which the environmental characteristics are defined. The potentially surprising weak sensitivity of cloud morphology to CAPE is discussed in detail.
A theory‐based parameterization for heterogeneous ice nucleation and implications for the simulation of ice processes in atmospheric models
Authors: Savre J. , Ekman A. M. L. 
Published: April 2015

AbstractA new parameterization for heterogeneous ice nucleation constrained by laboratory data and based on classical nucleation theory is introduced. Key features of the parameterization include the following: a consistent and modular modeling framework for treating condensation/immersion and deposition freezing, the possibility to consider various potential ice nucleating particle types (e.g., dust, black carbon, and bacteria), and the possibility to account for an aerosol size distribution. The ice nucleating ability of each aerosol type is described using a contact angle (θ) probability density function (PDF). A new modeling strategy is described to allow the θ PDF to evolve in time so that the most efficient ice nuclei (associated with the lowest θ values) are progressively removed as they nucleate ice. A computationally efficient quasi Monte Carlo method is used to integrate the computed ice nucleation rates over both size and contact angle distributions. The parameterization is employed in a parcel model, forced by an ensemble of Lagrangian trajectories extracted from a three‐dimensional simulation of a springtime low‐level Arctic mixed‐phase cloud, in order to evaluate the accuracy and convergence of the method using different settings. The same model setup is then employed to examine the importance of various parameters for the simulated ice production. Modeling the time evolution of the θ PDF is found to be particularly crucial; assuming a time‐independent θ PDF significantly overestimates the ice nucleation rates. It is stressed that the capacity of black carbon (BC) to form ice in the condensation/immersion freezing mode is highly uncertain, in particular at temperatures warmer than −20°C. In its current version, the parameterization most likely overestimates ice initiation by BC.
Coseismic and postseismic deformation due to the 2007 M5.5 Ghazaband fault earthquake, Balochistan, Pakistan
Authors: Fattahi H. , Amelung F. , Chaussard E. , Wdowinski S. 
Published: April 2015

AbstractTime series analysis of interferometric synthetic aperture radar data reveals coseismic and postseismic surface displacements associated with the 2007 M5.5 earthquake along the southern Ghazaband fault, a major but little studied fault in Pakistan. Modeling indicates that the coseismic surface deformation was caused by ~9 cm of strike‐slip displacement along a shallow subvertical fault. The earthquake was followed by at least 1 year of afterslip, releasing ~70% of the moment of the main event, equivalent to a M5.4 earthquake. This high aseismic relative to the seismic moment release is consistent with previous observations for moderate earthquakes (M < 6) and suggests that smaller earthquakes are associated with a higher aseismic relative to seismic moment release than larger earthquakes.
GRACE gravity observations constrain Weichselian ice thickness in the Barents Sea
Authors: Root B. C. , Tarasov L. , van der Wal W. 
Published: April 2015

AbstractThe Barents Sea is subject to ongoing postglacial uplift since the melting of the Weichselian ice sheet that covered it. The regional ice sheet thickness history is not well known because there is only data at the periphery due to the locations of Franz Joseph Land, Svalbard, and Novaya Zemlya surrounding this paleo ice sheet. We show that the linear trend in the gravity rate derived from a decade of observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission can constrain the volume of the ice sheet after correcting for current ice melt, hydrology, and far‐field gravitational effects. Regional ice‐loading models based on new geologically inferred ice margin chronologies show a significantly better fit to the GRACE data than that of ICE‐5G. The regional ice models contain less ice in the Barents Sea than present in ICE‐5G (5–6.3 m equivalent sea level versus 8.5 m), which increases the ongoing difficulty in closing the global sea level budget at the Last Glacial Maximum.
Pattern of cryospheric seismic events observed at Ekström Ice Shelf, Antarctica
Authors: Hammer Conny , Ohrnberger Matthias , Schlindwein Vera 
Published: April 2015

AbstractMobility of glaciers such as rapid retreat or disintegration of large ice volumes produces a large variety of different seismic signals. Thus, evaluating cryospheric seismic events (e.g., changes of their occurrence in space and time) allows to monitor glacier dynamics. We analyze a 1 year data span recorded at the Neumayer seismic network in Antarctica. Events are automatically recognized using hidden Markov models. In this study we focused on a specific event type occurring close to the grounding line of the Ekström ice shelf. Observed waveform characteristics are consistent with an initial fracturing followed by the resonance of a water‐filled cavity resulting in a so‐called hybrid event. The number of events detected strongly correlates with dominant tide periods. We assume the cracking to be driven by existing glacier stresses trough bending. Voids are then filled by seawater, exciting the observed resonance. In agreement with this model, events occur almost exclusively during rising tides where cavities are opened at the bottom of the glacier, i.e., at the sea/ice interface.
Three‐dimensional current systems and ionospheric effects associated with small dipolarization fronts
Authors: Palin L. , Jacquey C. , Opgenoorth H. , Connors M. , Sergeev V. , Sauvaud J.‐A. , Nakamura R. , Reeves G. D. , Singer H. J. , Angelopoulos V. , Turc L. 
Published: April 2015

AbstractWe present a case study of eight successive plasma sheet (PS) activations (usually referred to as bursty bulk flows or dipolarization fronts), associated with small individual increases on 31 March 2009 (0200–0900 UT), observed by the Time History of Events and Macroscale Interactions During Substorms mission. This series of events happens during very quiet solar wind conditions, over a period of 7 h preceding a substorm onset at 1230 UT. The amplitude of the dipolarizations increases with time. The low‐amplitude dipolarization fronts are associated with few (1 or 2) rapid flux transport events (RFT, Eh>2 mV/m), whereas the large‐amplitude ones encompass many more RFT events. All PS activations are associated with small and localized substorm current wedge (SCW)‐like current system signatures, which seems to be the consequence of RFT arrival in the near tail. The associated ground magnetic perturbations affect a larger part of the contracted auroral oval when, in the magnetotail, more RFT are embedded in PS activations (>5). Dipolarization fronts with very low amplitude, a type usually not included in statistical studies, are of particular interest because we found even those to be associated with clear small SCW‐like current system and particle injections at geosynchronous orbit. This exceptional data set highlights the role of flow bursts in the magnetotail and leads to the conclusion that we may be observing the smallest form of a substorm or rather its smallest element. This study also highlights the gradual evolution of the ionospheric current disturbance as the plasma sheet is observed to heat up.