bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemometrics Tools in Detection and Quantitation of the Main Impurities Present in Aspirin/Dipyridamole Extended-Release Capsules
Authors: El-Ragehy Nariman A , Yehia Ali M , Hassan Nagiba Y , Tantawy Mahmoud A , Abdelkawy Mohamed
Published: June 2016

Aspirin (ASP) and dipyridamole (DIP) in combination is widely used in the prevention of secondary events after stroke and transient ischemic attack. Salicylic acid is a well-known impurity of ASP, and the DIP extended-release formulation may contain ester impurities originating from the reaction with tartaric acid. UV spectral data analysis of the active ingredients in the presence of their main impurities is presented using multivariate approaches. Four chemometric-assisted spectrophotometric methods, namely, partial least-squares, concentration residuals augmented classical least-squares (CRACLS), multivariate curve resolution (MCR) alternating least-squares (ALS), and artificial neural networks, were developed and validated. The quantitative analyses of all the proposed calibrations were compared by percentage recoveries, root mean square error of prediction, and standard error of prediction. In addition, r2 values between the pure and estimated spectral profiles were used to evaluate the qualitative analysis of CRACLS and MCR-ALS. The lowest error was obtained by the CRACLS model, whereas the best correlation was achieved using MCR-ALS. The four multivariate calibration methods could successfully be applied for the extended-release formulation analysis. The application results were also validated by analysis of the stored dosage-form solution, which showed a susceptibility of DIP esterification in the extended-release formulation. Statistical comparison between the proposed and official methods showed no significant difference.
Sensitive Determination of Uranium in Natural Waters Using UV-Vis Spectrometry After Preconcentration by Ion-Imprinted Polymer-Ternary Complexes
Authors: Bicim Tulin , Yaman Mehmet
Published: June 2016

The main purpose of this study was to achieve a substantial increase in the sensitivity of the uranium determination using UV-Vis spectrometry. To achieve this goal, ion-imprinted polymers were prepared for the uranyl (imprint) ion by the formation of a ternary (salicylaldoxime and 4-vinylpyridine) complex in 2-methoxy ethanol (porogen) following copolymerization with methacrylic acid. The synthesized polymers were characterized by FTIR analysis and thermogravimetric analysis. In the preconcentration step, the optimal pH was determined to be between values of 3.5 and 6.5. The adsorbed UO22+ was completely eluted by 10 mL of 3.0 mol L−1 HClO4. The developed method was applied to uranium (VI) determination in natural water samples. By using the initial volume of 500 mL and final volume of 5 mL, a concentration of 1 μg L−1 can be determined by applying the developed method in this study.
Changing Patterns of Fungal Toxins in Crops: Challenges for Analysts
Authors: Miller J David
Published: June 2016

This short review discusses the need to manage climate-driven expansion of old toxins in new geographic areas (e.g., aflatoxin or fumonisin in corn in historically cooler areas, and ergot where rainfall and cropping patterns have changed). In addition, a renewed consideration of the toxins that can occur in feed sources used in cool-season dairy areas is needed (e.g., silage and distillers dry grains with solubles). A separate issue concerns genetic changes that are occurring in the species that cause Fusarium head blight/Gibberella ear rot. Small differences in climate appear to determine the distribution of the two dominant populations (native to the new world and from Asia). The chemotype that produces deoxynivalenol via the monoacetate at the 3 position results in the accumulation of somewhat more deoxynivalenol than the native population, which involves the monoacetate at the 15 position. There are also genetic changes occurring that have resulted in populations that produce different metabolites. Similarly, an increase in the area where Aspergillus flavus can thrive and the discovery of the sexual stage of this fungus have raised the potential of genetic change accelerated by climate. To address all these issues, new methods and increased availability of reference standards, as well as training and awareness, will be required.
The (3,1)-ordering for 4-connected planar triangulations
Authors: Biedl Therese , Derka Martin
Published: June 2016

Canonical orderings of planar graphs have frequently been used in graph drawing and other graph algorithms. In this paper we introduce the notion of an
$(r,s)$-canonical order, which unifies many of the existing variants of
canonical orderings. We then show that $(3,1)$-canonical ordering
for 4-connected triangulations always exist; to our knowledge
this variant of canonical ordering was not previously known.
We use it to give much simpler proofs of two previously known graph drawing
results for 4-connected planar triangulations, namely, rectangular duals
and rectangle-of-influence drawings.
HIV‐positive pregnant and postpartum women's perspectives about Option B+ in Malawi: a qualitative study
Authors: Katirayi Leila , Namadingo Hazel , Phiri Mafayo , Bobrow Emily A , Ahimbisibwe Allan , Berhan Aida Yemane , Buono Nicole , Moland Karen Marie , Tylleskär Thorkild
Published: June 2016

Introduction

The implementation of lifelong antiretroviral treatment (ART) for all pregnant women (Option B+) in Malawi has resulted in a significant increase in the number of HIV‐positive pregnant women initiating treatment. However, research has highlighted the challenge of retaining newly initiated women in care. This study explores barriers and facilitators that affect a woman's decision to initiate and to adhere to Option B+.

Methods

A total of 39 in‐depth interviews and 16 focus group discussions were conducted. Eligible women were ≥18 years old, living with HIV and either pregnant and receiving antenatal care from a study site or had delivered a child within the last 18 months, breastfed their child and received services at one of the study sites. Eligible women were identified by healthcare workers (HCWs) in the antenatal clinic and ART unit. Focus groups were also conducted with HCWs employed in these departments. Qualitative data were analyzed using Maxqda version 10 (VERBI Software, Berlin, Germany).

Results

The general perception towards the drug regimen used in Option B+ was positive; women reported fewer side effects and acknowledged the positive benefits of ART. Women felt hopeful about prolonging their life and having an HIV‐uninfected baby, yet grappled with the fact that ART is a lifelong commitment. Women and HCWs discussed challenges with the counselling services for prevention of mother‐to‐child HIV transmission under the new Option B+ guidelines, and many women struggled with initiating ART on the same day as learning their HIV status. Women wanted to discuss their circumstances with their husbands first, receive a CD4 count and obtain an HIV test at another facility to confirm their HIV status. HCWs expressed concern that women might just agree to take the drugs to please them. HCWs also discussed concerns around loss to follow‐up and drug resistance.

Conclusions

Although Option B+ has significantly increased the number of women initiating ART, there are still challenges that need to be addressed to strengthen initiation, adherence and retention in care. Strategies to strengthen the counselling services upon diagnosis need to be developed to improve same‐day initiation of ART and long‐term adherence.
Phosphorylation acts positively and negatively to regulate MRTF-A subcellular localisation and activity
Authors: Panayiotou Richard , Miralles Francesc , Pawlowski Rafal , Diring Jessica , Flynn Helen R , Skehel Mark , Treisman Richard
Published: June 2016

The myocardin-related transcription factors (MRTF-A and MRTF-B) regulate cytoskeletal genes through their partner transcription factor SRF. The MRTFs bind G-actin, and signal-regulated changes in cellular G-actin concentration control their nuclear accumulation. The MRTFs also undergo Rho- and ERK-dependent phosphorylation, but the function of MRTF phosphorylation, and the elements and signals involved in MRTF-A nuclear export are largely unexplored. We show that Rho-dependent MRTF-A phosphorylation reflects relief from an inhibitory function of nuclear actin. We map multiple sites of serum-induced phosphorylation, most of which are S/T-P motifs and show that S/T-P phosphorylation is required for transcriptional activation. ERK-mediated S98 phosphorylation inhibits assembly of G-actin complexes on the MRTF-A regulatory RPEL domain, promoting nuclear import. In contrast, S33 phosphorylation potentiates the activity of an autonomous Crm1-dependent N-terminal NES, which cooperates with five other NES elements to exclude MRTF-A from the nucleus. Phosphorylation thus plays positive and negative roles in the regulation of MRTF-A.
Supercontinuum generation using a selectively water-filled photonic crystal fiber for enhancement in the visible spectral region
Authors: Yoshida Eiichi , Wada Akira , Karasawa Naoki
Published: June 2016

We generated a supercontinuum from a selectively water-filled photonic crystal fiber (PCF) for enhancement in the visible spectral region using an optical pulse from a Ti:sapphire oscillator at 804 nm. We prepared a 7-cm-long fused silica PCF, where the holes adjacent to the central core were filled with water, using a UV-curable adhesive to close holes selectively before filling holes with water by capillary force. Compared with that of the PCF without water, the group velocity dispersion curve of the selectively water-filled PCF became flatter near 800 nm and the intensity in the visible spectral region of the supercontinuum became higher and more uniform. The spectra simulated using the calculated dispersion properties of the selectively water-filled PCF showed good agreement with the experimental spectra.
Stability evaluation of parameter estimation of multi-Rayleigh model for ultrasound B-mode image of liver fibrosis
Authors: Mori Shohei , Ohashi Minori , Hirata Shinnosuke , Hachiya Hiroyuki
Published: June 2016

A diagnosis of liver fibrosis using an ultrasound B-mode image has the advantages of real-time observation and noninvasive properties. In our previous study, a multi-Rayleigh model was proposed to express a probability density function (PDF) of echo amplitudes from a fibrotic liver. From the multi-Rayleigh model, fibrosis parameters, such as the amount of fibrotic tissue and its progressive ratio, can be extracted. To quantitatively evaluate liver fibrosis using the multi-Rayleigh model, it is important to evaluate the stability of the estimation method of multi-Rayleigh model parameters. In this study, a numerical simulation using random variables following the multi-Rayleigh model was performed and the estimation stability of the parameters of the multi-Rayleigh model with two components was examined. From the simulation results, it was found that estimation becomes unstable under a certain condition owing to statistical variations of moments, which are inputs in the estimation algorithm. The instability of estimated parameters could be evaluated by focusing on changes in moments upon changes in multi-Rayleigh model parameters. It was indicated that we can evaluate the reliability of the estimated parameters of the multi-Rayleigh model only from the estimated values.
Shear wavelength estimation based on inverse filtering and multiple-point shear wave generation
Authors: Kitazaki Tomoaki , Kondo Kengo , Yamakawa Makoto , Shiina Tsuyoshi
Published: June 2016

Elastography provides important diagnostic information because tissue elasticity is related to pathological conditions. For example, in a mammary gland, higher grade malignancies yield harder tumors. Estimating shear wave speed enables the quantification of tissue elasticity imaging using time-of-flight. However, time-of-flight measurement is based on an assumption about the propagation direction of a shear wave which is highly affected by reflection and refraction, and thus might cause an artifact. An alternative elasticity estimation approach based on shear wavelength was proposed and applied to passive configurations. To determine the elasticity of tissue more quickly and more accurately, we proposed a new method for shear wave elasticity imaging that combines the shear wavelength approach and inverse filtering with multiple shear wave sources induced by acoustic radiation force (ARF). The feasibility of the proposed method was verified using an elasticity phantom with a hard inclusion.
Integrated microRNA, gene expression and transcription factors signature in papillary thyroid cancer with lymph node metastasis
Authors: Ab Mutalib Nurul-Syakima , Othman Sri Noraima , Mohamad Yusof Azliana , Abdullah Suhaimi Shahrun Niza , Muhammad Rohaizak , Jamal Rahman
Published: June 2016

Background. Papillary thyroid carcinoma (PTC) is the commonest thyroid malignancy originating from the follicle cells in the thyroid. Despite a good overall prognosis, certain high-risk cases as in those with lymph node metastasis (LNM) have progressive disease and poorer prognosis. MicroRNAs are a class of non-protein-coding, 19-24 nucleotides single-stranded RNAs which regulate gene expression and these molecules have been shown to play a role in LNM. The integrated analysis of miRNAs and gene expression profiles together with transcription factors (TFs) has been shown to improve the identification of functional miRNA-target gene-TF relationships, providing a more complete view of molecular events underlying metastasis process.

Objectives. We reanalyzed The Cancer Genome Atlas (TCGA) datasets on PTC to identify differentially expressed miRNAs/genes in PTC patients with LNM-positive (LNM-P) versus lymph node negative (LNN) PTC patients and to investigate the miRNA-gene-TF regulatory circuit that regulate LNM in PTC.

Results. PTC patients with LNM (PTC LNM-P) have a significantly shorter disease-free survival rate compared to PTC patients without LNM (PTC LNN) (Log-rank Mantel Cox test,p= 0.0049). We identified 181 significantly differentially expressed miRNAs in PTC LNM-P versus PTC LNN; 110 were upregulated and 71 were downregulated. The five topmost deregulated miRNAs were hsa-miR-146b, hsa-miR-375, hsa-miR-31, hsa-miR-7-2 and hsa-miR-204. In addition, 395 miRNAs were differentially expressed between PTC LNM-P and normal thyroid while 400 miRNAs were differentially expressed between PTC LNN and normal thyroid. We found four significant enrichment pathways potentially involved in metastasis to the lymph nodes, namely oxidative phosphorylation (OxPhos), cell adhesion molecules (CAMs), leukocyte transendothelial migration and cytokine--cytokine receptor interaction. OxPhos was the most significantly perturbed pathway (p= 4.70E−06) involving downregulation of 90 OxPhos-related genes. Significant interaction of hsa-miR-301b with HLF, HIF and REL/NFkB transcription factors were identified exclusively in PTC LNM-P versus PTC LNN.

Conclusion. We found evidence of five miRNAs differentially expressed in PTC LNM-P. Alteration in OxPhos pathway could be the central event in metastasis to the lymph node in PTC. We postulate that hsa-miR-301b might be involved in regulating LNM in PTC via interactions with HLF, HIF and REL/NFkB. To the best of our knowledge, the roles of these TFs have been studied in PTC but the precise role of this miRNA with these TFs in LNM in PTC has not been investigated.
Screening for drought tolerance in cultivars of the ornamental genusTagetes(Asteraceae)
Authors: Cicevan Raluca , Al Hassan Mohamad , Sestras Adriana F. , Prohens Jaime , Vicente Oscar , Sestras Radu E. , Boscaiu Monica
Published: June 2016

Drought tolerance was evaluated in twelve cultivars of three ornamentalTagetesspecies (T. patula,T. tenuifoliaandT. erecta). A stress treatment was performed by completely stopping watering of plants maintained in controlled greenhouse conditions. After three weeks, several plant growth parameters (stem length (SL), fresh weight (FW) and water content (WC)), photosynthetic pigments (chlorophylls and carotenoids (Car)), osmolytes (proline (Pro), glycine betaine (GB) and total soluble sugars (TSS)), an oxidative stress maker (malondialdehyde (MDA)) and antioxidants (total phenolic compounds (TPC) and total flavonoids (TF)) were measured. Considerable differences in the evaluated traits were found among the control and drought-stressed plants. Drought stress generally caused a marked reduction in plant growth and carotenoid pigments, and an increase in soluble solutes and oxidative stress. For most cultivars, proline levels in stressed plants increased between 30 and 70-fold compared to the corresponding controls. According to the different measured parameters, on averageT. erectaproved to be more tolerant to drought thanT. patulaandT. tenuifolia. However, a considerable variation in the tolerance to drought was found within each species. The traits with greater association to drought tolerance as well as the most tolerant cultivars could be clearly identified in a principal components analysis (PCA). Overall, our results indicate that drought tolerant cultivars ofTagetescan be identified at early stages using a combination of plant growth and biochemical markers.
Freshwater gastropods diversity hotspots: three new species from the Uruguay River (South America)
Authors: Gutiérrez Gregoric Diego E. , de Lucía Micaela
Published: June 2016

Background:The Atlantic Forest is globally one of the priority ecoregions for biodiversity conservation. In Argentina, it is represented by the Paranense Forest, which covers a vast area of Misiones Province between the Paraná and Uruguay rivers. The Uruguay River is a global hotspot of freshwater gastropod diversity, here mainly represented by Tateidae (genusPotamolithus) and to a lesser extent Chilinidae. The family Chilinidae (Gastropoda, Hygrophila) includes 21 species currently recorded in Argentina, and three species in the Uruguay River. The species of Chilinidae occur in quite different types of habitats, but generally in clean oxygenated water recording variable temperature ranges. Highly oxygenated freshwater environments (waterfalls and rapids) are the most vulnerable continental environments. We provide here novel information on three new species of Chilinidae from environments containing waterfalls and rapids in the Uruguay River malacological province of Argentina.

Materials and Methods:The specimens were collected in 2010. We analyzed shell, radula, and nervous and reproductive systems, and determined the molecular genetics. The genetic distance was calculated for two mitochondrial markers (cytochromecoxidase subunit I–COI- and cytochrome b -Cyt b-) for these three new species and the species recorded from the Misionerean, Uruguay River and Lower Paraná-Río de la Plata malacological provinces. In addition, the COI data were analyzed phylogenetically by the neighbor-joining and Bayesian inference techniques.

Results:The species described here are different in terms of shell, radula and nervous and reproductive systems, mostly based on the sculpture of the penis sheath. Phylogenetic analyses grouped the three new species with those present in the Lower Paraná-Río de la Plata and Uruguay River malacological provinces.

Discussion:Phylogenetic analyses confirm the separation between the Uruguay River and the Misionerean malacological provinces in northeast Argentina. These new endemic species from the Uruguay River add further support to the suggestion that this river is a diversity hotspot of freshwater gastropods (with 54 species present in this basin, 15 of them endemic). These endemic species from environments with rapids and waterfalls should be taken into account by government agencies before the construction of dams that modify those ecologic niches in the Uruguay River.
Sonographic Prediction of Pediatric Renal Scarring With Full Parameter Normalization
Authors: Stember Joseph N. , Lynch Dustin , Behr Gerald , Alam Shumyle
Published: June 2016

Objectives

To predict the chronic kidney disease (CKD) state for pediatric patients based on scaled renal cortical echogenicity.

Methods

Sonograms from a cohort of 26 patients, half of whom had stage 4 or 5 CKD, whereas the other half had normal renal function, were analyzed. For each patient image, a region of interest (ROI) was drawn around the renal cortex for comparison with an ROI drawn around the hepatic parenchyma. The latter ROI was shifted spatially to normalize the signal attenuations and time‐gain compensations of the two organs’ ROIs. Then the average pixel intensity of the renal ROI was divided by the corresponding hepatic value, resulting in scaled renal cortical echogenicity.

Results

The average scaled renal cortical echogenicity was higher for diseased than healthy kidneys by roughly a factor of 2 (2.01 [95% confidence interval, 1.62–2.40] versus 1.05 [95% confidence interval, 0.88–1.23] for normal kidneys). This difference was statistically significant (P < .001).

Conclusions

Our results show that the pediatric CKD state correlates with rigorously calculated scaled renal cortical echogenicity.
Artificial periodic irregularities in the high‐latitude ionosphere excited by the HAARP facility
Authors: Bakhmetieva N. V. , Grach S. M. , Sergeev E. N. , Shindin A. V. , Milikh G. M. , Siefring C. L. , Bernhardt P. A. , McCarrick M.
Published: June 2016

We present results of the new observations of artificial periodic irregularities (APIs) in the ionosphere using the High Frequency Active Auroral Research Program (HAARP) heating facility carried out in late May and early June 2014.The objective of this work is to detect API using high‐latitude facility and analyze possible differences of the temporal and spatial variations of the API echoes in the high (HAARP) and middle (Sura) latitudes. Irregularities were created by the powerful wave of X mode and were sounded using the short probing pulses signals of X mode. API echoes were observed in the D, E, and F regions of the ionosphere. Amplitudes and characteristic times of the API echoes were measured. The API growth and decay times at HAARP (high latitudes) observed were similar to those at the Sura heating facility (midlatitudes).
Dual assimilation of satellite soil moisture to improve streamflow prediction in data‐scarce catchments
Authors: Alvarez‐Garreton Camila , Ryu Dongryeol , Western Andrew W. , Crow Wade T. , Su Chun‐Hsu , Robertson David R.
Published: June 2016

This paper explores the use of active and passive microwave satellite soil moisture products for improving streamflow prediction within four large (>5000km2) semiarid catchments in Australia. We use the probability distributed model (PDM) under a data‐scarce scenario and aim at correcting two key controlling factors in the streamflow generation: the rainfall forcing data and the catchment wetness condition. The soil moisture analysis rainfall tool (SMART) is used to correct a near real‐time satellite rainfall product (forcing correction scheme) and an ensemble Kalman filter is used to correct the PDM soil moisture state (state correction scheme). These two schemes are combined in a dual correction scheme and we assess the relative improvements of each. Our results demonstrate that the quality of the satellite rainfall product is improved by SMART during moderate‐to‐high daily rainfall events, which in turn leads to improved streamflow prediction during high flows. When employed individually, the soil moisture state correction scheme generally outperforms the rainfall correction scheme, especially for low flows. Overall, the combined dual correction scheme further improves the streamflow predictions (reduction in root mean square error and false alarm ratio, and increase in correlation coefficient and Nash‐Sutcliffe efficiency). Our results provide new evidence of the value of satellite soil moisture observations within data‐scarce regions. We also identify a number of challenges and limitations within the schemes.
Changes in anthropogenic nitrogen and phosphorus inputs to the St. Lawrence sub‐basin over 110 years and impacts on riverine export
Authors: Goyette Jean‐Olivier , Bennett Elena M. , Howarth Robert W. , Maranger Roxane
Published: June 2016

Human activities have increased the flow of nitrogen (N) and phosphorus (P) over much of the Earth, leading to increased agricultural production, but also the degradation of air, soil, and water quality. Here we quantify the sources of anthropogenic N and P inputs to 76 watersheds of the St. Lawrence Basin (SLB) throughout the 20th century using NANI/NAPI (net anthropogenic N/P input to watersheds), a mass balance modeling approach, and estimate the fraction of these inputs exported to adjacent rivers. Our results show that since 1901, NANI and NAPI increased 4.5‐fold and 3.8‐fold, respectively, with a peak in 1991 mainly due to high atmospheric N deposition and P fertilizer application. However, the relative increase over the course of the last century was much higher in certain watersheds, particularly those where there was greater urbanization. Ranges in NANI and NAPI vary greatly among watersheds (110 to 9351 kg N km−2 yr−1 and 0.16 to 1938 kg P km−2 yr−1, respectively in 2011) and are strongly related to riverine fluxes (R2 = 0.87 and 0.71 for N and P, respectively). Our results suggest that 22% of NANI (ranging from 11% to 68% across watersheds) and 17% of NAPI (ranging from 3% to 173%) are exported to rivers. Predominant sources of inputs vary spatially and through time largely due to changes in farming practices. By tracking the main sources of inputs to specific watersheds and through time, our work provides insights for N and P management. Reduction strategies will likely need to be watershed specific, although through time, our results clearly show the large‐scale impact of targeted legislation.
Variability in the sensitivity among model simulations of permafrost and carbon dynamics in the permafrost region between 1960 and 2009
Authors: McGuire A. David , Koven Charles , Lawrence David M. , Clein Joy S. , Xia Jiangyang , Beer Christian , Burke Eleanor , Chen Guangsheng , Chen Xiaodong , Delire Christine , Jafarov Elchin , MacDougall Andrew H. , Marchenko Sergey , Nicolsky Dmitry , Peng Shushi , Rinke Annette , Saito Kazuyuki , Zhang Wenxin , Alkama Ramdane , Bohn Theodore J. , Ciais Philippe , Decharme Bertrand , Ekici Altug , Gouttevin Isabelle , Hajima Tomohiro , Hayes Daniel J. , Ji Duoying , Krinner Gerhard , Lettenmaier Dennis P. , Luo Yiqi , Miller Paul A. , Moore John C. , Romanovsky Vladimir , Schädel Christina , Schaefer Kevin , Schuur Edward A.G. , Smith Benjamin , Sueyoshi Tetsuo , Zhuang Qianlai
Published: June 2016

A significant portion of the large amount of carbon (C) currently stored in soils of the permafrost region in the Northern Hemisphere has the potential to be emitted as the greenhouse gases CO2 and CH4 under a warmer climate. In this study we evaluated the variability in the sensitivity of permafrost and C in recent decades among land surface model simulations over the permafrost region between 1960 and 2009. The 15 model simulations all predict a loss of near‐surface permafrost (within 3 m) area over the region, but there are large differences in the magnitude of the simulated rates of loss among the models (0.2 to 58.8 × 103 km2 yr−1). Sensitivity simulations indicated that changes in air temperature largely explained changes in permafrost area, although interactions among changes in other environmental variables also played a role. All of the models indicate that both vegetation and soil C storage together have increased by 156 to 954 Tg C yr−1 between 1960 and 2009 over the permafrost region even though model analyses indicate that warming alone would decrease soil C storage. Increases in gross primary production (GPP) largely explain the simulated increases in vegetation and soil C. The sensitivity of GPP to increases in atmospheric CO2 was the dominant cause of increases in GPP across the models, but comparison of simulated GPP trends across the 1982–2009 period with that of a global GPP data set indicates that all of the models overestimate the trend in GPP. Disturbance also appears to be an important factor affecting C storage, as models that consider disturbance had lower increases in C storage than models that did not consider disturbance. To improve the modeling of C in the permafrost region, there is the need for the modeling community to standardize structural representation of permafrost and carbon dynamics among models that are used to evaluate the permafrost C feedback and for the modeling and observational communities to jointly develop data sets and methodologies to more effectively benchmark models.
Asteroid bombardment and the core of Theia as possible sources for the Earth's late veneer component
Authors: Sleep Norman H.
Published: June 2016

The silicate Earth contains Pt‐group elements in roughly chondritic relative ratios, but with absolute concentrations <1% chondrite. This veneer implies addition of chondrite‐like material with 0.3–0.7% mass of the Earth's mantle or an equivalent planet‐wide thickness of 5–20 km. The veneer thickness, 200–300 m, within the lunar crust and mantle is much less. One hypothesis is that the terrestrial veneer arrived after the moon‐forming impact within a few large asteroids that happened to miss the smaller Moon. Alternatively, most of terrestrial veneer came from the core of the moon‐forming impactor, Theia. The Moon then likely contains iron from Theia's core. Mass balances lend plausibility. The lunar core mass is ∼1.6 × 1021kg and the excess FeO component in the lunar mantle is 1.3–3.5 × 1021kg as Fe, totaling 3–5 × 1021kg or a few percent of Theia's core. This mass is comparable to the excess Fe of 2.3–10 × 1021kg in the Earth's mantle inferred from the veneer component. Chemically in this hypothesis, Fe metal from Theia's core entered the Moon‐forming disk. H2O and Fe2O3in the disk oxidized part of the Fe, leaving the lunar mantle near a Fe‐FeO buffer. The remaining iron metal condensed, gathered Pt‐group elements eventually into the lunar core. The silicate Moon is strongly depleted in Pt‐group elements. In contrast, the Earth's mantle contained excess oxidants, H2O and Fe2O3, which quantitatively oxidized the admixed Fe from Theia's core, retaining Pt‐group elements. In this hypothesis, asteroid impacts were relatively benign with ∼1 terrestrial event that left only thermophile survivors.
The influences of solar wind pressure and interplanetary magnetic field on global magnetic field and outer radiation belt electrons
Authors: Yu J. , Li L.Y. , Cao J. B. , Reeves G. D. , Baker D. N. , Spence H.
Published: June 2016

Using the Van Allen Probe in situ measured magnetic field and electron data, we examine the solar wind dynamic pressure and interplanetary magnetic field (IMF) effects on global magnetic field and outer radiation belt relativistic electrons (≥1.8 MeV). The dynamic pressure enhancements (>2 nPa) cause the dayside magnetic field increase and the nightside magnetic field reduction, whereas the large southward IMFs (Bz‐IMF < −2nT) mainly lead to the decrease of the nightside magnetic field. In the dayside increased magnetic field region (magnetic local time (MLT) ~ 06:00–18:00, and L > 4), the pitch angles of relativistic electrons are mainly pancake distributions with a flux peak around 90° (corresponding anisotropic index A > 0.1), and the higher‐energy electrons have stronger pancake distributions (the larger A), suggesting that the compression‐induced betatron accelerations enhance the dayside pancake distributions. However, in the nighttime decreased magnetic field region (MLT ~ 18:00–06:00, and L ≥ 5), the pitch angles of relativistic electrons become butterfly distributions with two flux peaks around 45° and 135° (A < 0). The spatial range of the nighttime butterfly distributions is almost independent of the relativistic electron energy, but it depends on the magnetic field day‐night asymmetry and the interplanetary conditions. The dynamic pressure enhancements can make the nighttime butterfly distribution extend inward. The large southward IMFs can also lead to the azimuthal expansion of the nighttime butterfly distributions. These variations are consistent with the drift shell splitting and/or magnetopause shadowing effect.
Multipoint observations of the structure and evolution of foreshock bubbles and their relation to hot flow anomalies
Authors: Liu Terry Z. , Turner Drew L. , Angelopoulos Vassilis , Omidi Nick
Published: June 2016

When backstreaming foreshock ions pass through approaching solar wind discontinuities, they may get concentrated upstream of the discontinuities and form foreshock bubbles (FBs). Because FBs result in very intense global pressure variations upstream of and inside Earth's magnetosphere, they are important for solar wind‐magnetosphere coupling. Information about these recently discovered phenomena is limited, however. To elucidate FB spatial structure, evolution, expansion, and formation conditions, we use multipoint Time History of Events and Macroscale Interactions during Substorms observations in which three or more spacecraft observed the same events. From single‐case studies of two foreshock bubbles and one hot flow anomaly (HFA), we demonstrate how we determine FB spatial structure, evolution, and expansion and propose a model to explain these properties. We discuss the different conditions leading to formation of FBs and HFAs. Multiple case studies of six FBs, five HFAs, and one spontaneous HFA show that FBs typically expand faster than HFAs and their expansion speed is likely determined by the solar wind speed.
Evidence of rising and poleward shift of storm surge in western North Pacific in recent decades
Authors: Oey Lie‐Yauw , Chou Simon
Published: June 2016

Recently, there has been considerable interest in examining how sea‐level extremes due to storm surge may be related to climate change. Evidence of how storm‐surge extremes have evolved since the start of the most recent warming of mid‐1970s and early 1980s has not been firmly established however. Here we use 64 years (1950–2013) of observations and model simulations, and find evidence of a significant rise in the intensity as well as poleward‐shifting of location of typhoon surges in the western North Pacific after 1980s. The rising and poleward‐shifting trends are caused by the weakening of the steering flow in the tropics, which is related to climate warming, resulting in slower‐moving and longer‐lasting typhoons which had shifted northward.
Using CryoSat‐2 altimeter data to evaluate M2 internal tides observed from multisatellite altimetry
Authors: Zhao Zhongxiang
Published: June 2016

This paper evaluates M2 internal tides observed from multisatellite altimetry (MultiSat20yr) using CryoSat‐2 altimeter data. MultiSat20yr is constructed using 20 years of sea surface height measurements made by multiple satellite altimeters from 1992 to 2012. Here it is demonstrated that M2 internal tides can also be extracted using 4 years of CryoSat‐2 data from 2011 to 2014 (CryoSat4yr) by the same plane wave fit method. MultiSat20yr and CryoSat4yr are in good agreement in the central North Pacific, although they are from satellite data of different sampling patterns (1998 versus 10,688 tracks) and different observational periods (20 versus 4 years). Further comparisons are carried out for three isolated wave components. MultiSat20yr and CryoSat4yr agree very well for both Hawaiian components, suggesting that the Hawaiian Ridge is a relatively stable generation site. In contrast, the Aleutian Ridge is a relatively unstable source in that the M2 amplitudes in MultiSat20yr and CryoSat4yr are very different. With respect to MultiSat20yr, the M2 internal tide in 2011–2014 propagates slower (faster) to the south (north) of Hawaii, respectively, suggesting that the internal tide's propagation speed is subject to significant interannual variability. This feature is supported by M2 internal tides observed using multisatellite altimeter data in 2005 (MultiSat2005) and Argo measured upper ocean temperature profiles. MultiSat20yr is used to correct M2 internal tides in the CryoSat‐2 data. Significant and efficient variance reduction suggests that MultiSat20yr is a reliable internal tide model. A phase‐adjusted MultiSat20yr is built to account for the interannual variations, and it works better in internal tide correction.
Exploiting coastal altimetry to improve the surface circulation scheme over the central Mediterranean Sea
Authors: Jebri Fatma , Birol Florence , Zakardjian Bruno , Bouffard Jérome , Sammari Cherif
Published: June 2016

This work is the first study exploiting along track altimetry data to observe and monitor coastal ocean features over the transition area between the western and eastern Mediterranean Basins. The relative performances of both the AVISO and the X‐TRACK research regional altimetric data sets are compared using in situ observations. Both products are cross validated with tide gauge records. The altimeter‐derived geostrophic velocities are also compared with observations from a moored Acoustic Doppler Current Profiler. Results indicate the good potential of satellite altimetry to retrieve dynamic features over the area. However, X‐TRACK shows a more homogenous data coverage than AVISO, with longer time series in the 50 km coastal band. The seasonal evolution of the surface circulation is therefore analyzed by conjointly using X‐TRACK data and remotely sensed sea surface temperature observations. This combined data set clearly depicts different current regimes and bifurcations, which allows us to propose a new seasonal circulation scheme for the central Mediterranean. The analysis shows variations of the path and temporal behavior of the main circulation features: the Atlantic Tunisian Current, the Atlantic Ionian Stream, the Atlantic Libyan Current, and the Sidra Gyre. The resulting bifurcating veins of these currents are also discussed, and a new current branch is observed for the first time.
Using satellite‐derived optical thickness to assess the influence of clouds on terrestrial carbon uptake
Authors: Cheng S. J. , Steiner A. L. , Hollinger D. Y. , Bohrer G. , Nadelhoffer K. J.
Published: June 2016

Clouds scatter direct solar radiation, generating diffuse radiation and altering the ratio of direct to diffuse light. If diffuse light increases plant canopy CO2 uptake, clouds may indirectly influence climate by altering the terrestrial carbon cycle. However, past research primarily uses proxies or qualitative categories of clouds to connect the effect of diffuse light on CO2 uptake to sky conditions. We mechanistically link and quantify effects of cloud optical thickness (τc) to surface light and plant canopy CO2 uptake by comparing satellite retrievals of τc to ground‐based measurements of diffuse and total photosynthetically active radiation (PAR; 400–700 nm) and gross primary production (GPP) in forests and croplands. Overall, total PAR decreased with τc, while diffuse PAR increased until an average τc of 6.8 and decreased with larger τc. When diffuse PAR increased with τc, 7–24% of variation in diffuse PAR was explained by τc. Light‐use efficiency (LUE) in this range increased 0.001–0.002 per unit increase in τc. Although τc explained 10–20% of the variation in LUE, there was no significant relationship between τc and GPP (p > 0.05) when diffuse PAR increased. We conclude that diffuse PAR increases under a narrow range of optically thin clouds and the dominant effect of clouds is to reduce total plant‐available PAR. This decrease in total PAR offsets the increase in LUE under increasing diffuse PAR, providing evidence that changes within this range of low cloud optical thickness are unlikely to alter the magnitude of terrestrial CO2 fluxes.
Phosphorescence, Fluorescence, and Chemiluminescence in Clinical Chemistry
Authors: Albani Jihad R.
Published: June 2016

Several modern aspects of luminescence spectroscopy are considered, especially as they pertain to clinical analysis of endogenous substances and of drugs and their metabolites. Fluorescence and phosphorescence spectroscopies and chemiluminescence methods are compared. For this purpose, application of different dyes is described.
Chromatography in Process Analysis
Authors: Clemons Jerry
Published: June 2016

Process chromatography is an analytical technique that provides for the on‐line separation and measurement of the components of a mixture in a chemical process. The chromatographic analyzers utilized for on‐line analysis must operate in a continuous and automatic manner, taking a fixed quantity of sample, separating the chemical components using adsorption or partitioning columns, and measuring the concentration of each with a detector. The chromatograph provides both quantitative results, by measuring the area of the peak generated as the components pass through the detector, and qualitative results based on the retention time, which is measured from injection to detection.

The most commonly used process chromatographic analyzer is the process gas chromatograph because of its many applications in the hydrocarbon processing industry. A variety of valve, column, and detector configurations are available for these analyses, from parts per million to percent levels. All samples must be in gas phase or must be liquids that can be vaporized before analysis. The analyzers are controlled using a cyclic timing device that switches valves and columns as the components pass through the system to provide the necessary separation. This time cycle is a limitation of the technique for applications requiring continuous or very fast analysis times. Even with these limitations, the advantages of cost, flexibility, sensitivity, and reliability have made process gas chromatography (PGC) the most widely used analytical technique for on‐line process control.
Near‐Infrared Imaging of Polymers; from Basic Science to Industrial Applications
Authors: Shinzawa Hideyuki , Ishikawa Daitaro , Ishigaki Mika , Ozaki Yukihiro
Published: June 2016

This article aims at outlining recent progress in near‐infrared (NIR) imaging particularly for polymer science and engineering. NIR imaging is useful in nondestructive and in situ analysis of various kinds of polymers, even thick films and bulk materials. NIR imaging provides novel information about the spatial distribution of sample components, the distribution of different morphologies or physical properties, and dynamic process such as polymer dissolution. In this article, the characteristics and advantages of NIR imaging are described first and then two newly developed NIR imaging instruments are introduced. Finally, several examples of applications of NIR imaging to polymer science and engineering are discussed.
X
‐Ray Sources for Handheld
X
‐Ray Fluorescence Instruments
Authors: Cornaby Sterling , Kozaczek Kris
Published: June 2016

This article discusses the current status of X‐ray sources (tubes and power supplies) used in handheld X‐ray fluorescence instruments. It outlines the basics of the tube and high‐voltage power supply (HVPS) design and the functionality of X‐ray sources designed specifically for handheld X‐ray fluorescence (XRF). Further, the testing methodologies of the tubes and power supplies are discussed. Finally, the selection criteria for the X‐ray source for common applications are presented.
Using Advanced Correlative Microscopy to Study Complex Biological Samples
Authors: Sueters ‐ Di Meo Josey , Liv Nalan , Hoogenboom Jacob P.
Published: June 2016

Correlation between light, mostly fluorescence, and electron microscopy (EM) is needed to identify biological molecules within their ultrastructural context and/or to relate the ultrastructure to preceding dynamics of biological molecules. Recent development of labels, sample preparation techniques, and microscopy tools allow researchers to bridge the gap between these two modalities, while dedicated, integrated microscopes merge the two techniques into one. This not only allows broader possibilities for implementation of CLEM (correlative light and electron microscopy) in analytical sciences but also enables novel applications crossing boundaries between the traditional microscopes. We provide an overview of the different CLEM approaches, including common labels and sample preparation techniques, and focus attention specifically on the advanced instrumentation and the novel opportunities and challenges these bring for the chemical and biological sciences.
Metabolism‐Based Drug–Drug Interactions in Critically Ill Patients: Clinical Relevance and Predictability ofIn VitroSystems
Authors: Mouly Stéphane , Spriet Isabel , Wauters Joost , Annaert Pieter , Meune Christophe , Bergmann Jean‐François
Published: June 2016

Drug–drug interactions (DDIs) contribute mainly to the incidence of adverse drug reactions. Important advances in the knowledge of human drug‐metabolizing enzymes have fueled the integration of in vitro drug metabolism and clinical DDI studies for the use in drug development programs and in the clinical setting. The activities of cytochrome P450 (CYP) 3A4 and P‐glycoprotein are critical determinants of drug clearance and are involved in the mechanism of numerous clinically relevant DDI. Human liver, intestinal samples, and recombinant human CYP3A4 are now available as in vitro screening tools to predict the potential for in vivo DDI. The interpretation and extrapolation of in vitro interaction data to in vivo situations require a good understanding of pharmacokinetic principles. In this chapter, research on drug metabolism and DDI along with examples illustrating the utility of specific in vitro or in vivo approaches is presented. In addition, the impact and clinical relevance of complexities such as dosing‐route‐dependent effects, multisite kinetics of drug‐metabolizing enzymes, and non‐CYP determinants of metabolic clearance are addressed.
Metabolic Characterization of Cell Systems Used inIn VitroToxicology Testing
Authors: Garcia‐Canton Carolina , Minet Emmanuel
Published: June 2016

The use of cell lines is one of the pillars forin vitrotoxicology testing; however, most cell lines lack tissue‐specific metabolic capabilities. The absence of competency to exert physiologically relevant metabolism could lead to a bias in the setting of threshold doses for risk assessment purposes, especially in the context of the consumer product and pharmaceutical industries. Metabolism is therefore a key element and also a limitation in testing ofin vitrotoxicology. In this chapter,in vitrotoxicology models as an alternative to animal testing and the metabolism requirements expected in an optimal cell system have been summarized. The areas that are emerging and that could lead to the development of next‐generationin vitrosystems for toxicology testing, such as stem cells, are also reviewed. Overall, the benefits of clearly establishing the metabolic competency ofin vitrosystems are highlighted. This approach will help us to understand the possible limitations associated with a model that is included as part of a fully integrated human risk assessment strategy.