bluuebunny/crossref_metadata_2025 huggingface dataset:
Topological Effects on Globular Protein‐ELP Fusion Block Copolymer Self‐Assembly
Authors: Qin Guokui , Glassman Matthew J. , Lam Christopher N. , Chang Dongsook , Schaible Eric , Hexemer Alexander , Olsen Bradley D.
Published: December 2014

Perfectly defined, monodisperse fusion protein block copolymers of a thermoresponsive coil‐like protein, ELP, and a globular protein, mCherry, are demonstrated to act as fully biosynthetic analogues to protein‐polymer conjugates that can self‐assemble into biofunctional nanostructures such as hexagonal and lamellar phases in concentrated solutions. The phase behavior of two mCherry‐ELP fusions, E10‐mCherry‐E10 and E20‐mCherry, is investigated to compare linear and bola fusion self‐assembly both in diluted and concentrated aqueous solution. In dilute solution, the molecular topology impacts the stability of micelles formed above the thermal transition temperature of the ELP block, with the diblock forming micelles and the bola forming unstable aggregates. Despite the chemical similarity of the two protein blocks, the materials order into block copolymer‐like nanostructures across a wide range of concentrations at 30 wt% and above, with the bola fusion having a lower order‐disorder transition concentration than the diblock fusion. The topology of the molecule has a large impact on the type of nanostructure formed, with the two fusions forming phases in the opposite order as a function of temperature and concentration. This new system provides a rich landscape to explore the capabilities of fusion architecture to control supramolecular assemblies for bioactive materials.
Biomineral Coating Increases Bone Formation by Ex Vivo BMP‐7 Gene Therapy in Rapid Prototyped Poly(l‐lactic acid) (PLLA) and Poly(ε‐caprolactone) (PCL) Porous Scaffolds
Authors: Saito Eiji , Suarez‐Gonzalez Darilis , Murphy William L. , Hollister Scott J.
Published: December 2014

Porousbiodegradable polymer scaffolds are widely utilized for bone tissue engineering, but are not osteoconductive like calcium phosphate scaffolds. We combine indirect solid freeform fabrication (SFF), ex vivo gene therapy, with biomineral coating to compare the effect of biomineral coating on bone regeneration for Poly (l‐lactic acid) (PLLA) and Poly (ε‐caprolactone) (PCL) scaffolds with the same porous architecture. Scanning electron microscope (SEM) and micro‐computed tomography (μ‐CT) demonstrate PLLA and PCL scaffolds have the same porous architecture and are completely coated. All scaffolds are seeded with human gingival fibroblasts (HGF) transduced with adenovirus encoded with either bone morphogenetic protein 7 (BMP‐7) or green fluorescent protein (GFP), and implanted into mice subcutaneously for 3 and 10 weeks. Only scaffolds with BMP‐7 transduced HGFs show mineralized tissue formation. At 3 weeks some blood vessel‐like structures are observed in coated PLLA and PCL scaffolds, but there is no significant difference in bone ingrowth between the coated and uncoated scaffolds for either PLLA or PCL. At 10 weeks, however, coated scaffolds (both PLLA and PCL) have significantly more bone ingrowth than uncoated scaffolds, which have more fibrous tissue. Coated PLLA scaffolds have improved mechanical properties compared with uncoated PLLA scaffolds due to increased bone ingrowth.
When Eutectics Meet Plasmonics: Nanoplasmonic, Volumetric, Self‐Organized, Silver‐Based Eutectic
Authors: Sadecka Katarzyna , Gajc Marcin , Orlinski Krzysztof , Surma Hancza B. , Klos Andrzej , Jozwik‐Biala Iwona , Sobczak Kamil , Dluzewski Piotr , Toudert Johann , Pawlak Dorota A.
Published: December 2014

Due to the development of novel manufacturing technologies and the increasing availability of nano‐/micromaterials, plasmonics has become an emerging field in photonics research. Although the fabrication of metallic elements has already been widely demonstrated, the development of 3D plasmonic materials is progressing slowly. This paper reports the development of a self‐organized, 3D nanoplasmonic eutectic composite that exhibits localized surface plasmon resonance at 595 nm. This eutectic composite is produced by directional solidification with the micro‐pulling‐down method and consists of a 3D, multiscale network of silver, nanometer‐thick, micron‐long sheets, and triangular cross‐section microprecipitates embedded in a crystalline bismuth oxide matrix. Annealing at 600 °C further refined the structure and introduced metallic nanoparticles that exhibited plasmonic resonance in the optical region of the spectrum. This is the first demonstration of plasmonic behavior in a eutectic‐based composite, which is engineered specifically for this purpose using a self‐organization mechanism.
Healthy baby delivered vaginally from a brain‐dead mother
Authors: Kinoshita Yoshihiro , Kamohara Hidenobu , Kotera Atsushi , Sagishima Katsuyuki , Tashiro Takahiro , Niimori Daisuke
Published: December 2014

Case

A pregnant (20 gestational weeks) 32‐year‐old woman was found in cardiac arrest. Spontaneous circulation returned after 15 min. She became brain dead on the 13th hospital day. The patient was in stable circulatory condition under nasal desmopressin and 20–30 mg/day of hydrocortisone. On the 92nd hospital day at gestational week 33 + 3 days, natural labor began and a healthy 2,130‐g girl (Apgar 6/8) was delivered vaginally with minimum assistance.

Outcome

The baby was discharged 40 days after birth and followed up regularly.

Conclusion

Brain death remains a hopeless condition for patients, but a brain‐dead woman may still be able to naturally deliver a healthy baby.
Sodium channel slow inactivation as a therapeutic target for myotonia congenita
Authors: Novak Kevin R. , Norman Jennifer , Mitchell Jacob R. , Pinter Martin J. , Rich Mark M.
Published: December 2014

Objective

Patients with myotonia congenita have muscle hyperexcitability due to loss‐of‐function mutations in the chloride channel in skeletal muscle, which causes spontaneous firing of muscle action potentials (myotonia), producing muscle stiffness. In patients, muscle stiffness lessens with exercise, a change known as the warmup phenomenon. Our goal was to identify the mechanism underlying warmup and to use this information to guide development of novel therapy.

Methods

To determine the mechanism underlying warmup, we used a recently discovered drug to eliminate muscle contraction, thus allowing prolonged intracellular recording from individual muscle fibers during induction of warmup in a mouse model of myotonia congenita.

Results

Changes in action potentials suggested slow inactivation of sodium channels as an important contributor to warmup. These data suggested that enhancing slow inactivation of sodium channels might offer effective therapy for myotonia. Lacosamide and ranolazine enhance slow inactivation of sodium channels and are approved by the US Food and Drug Administration for other uses in patients. We compared the efficacy of both drugs to mexiletine, a sodium channel blocker currently used to treat myotonia. In vitro studies suggested that both lacosamide and ranolazine were superior to mexiletine. However, in vivo studies in a mouse model of myotonia congenita suggested that side effects could limit the efficacy of lacosamide. Ranolazine produced fewer side effects and was as effective as mexiletine at a dose that produced none of mexiletine's hypoexcitability side effects.

Interpretation

We conclude that ranolazine has excellent therapeutic potential for treatment of patients with myotonia congenita. Ann Neurol 2015;77:320–332.
Asymmetric Dual‐Reagent Catalysis: Mannich‐type Reactions Catalyzed by Ion Pair
Authors: Wang Hong‐Yu , Zhang Kai , Zheng Chang‐Wu , Chai Zhuo , Cao Dong‐Dong , Zhang Jia‐Xing , Zhao Gang
Published: December 2014

The combination of a new bifunctional phosphine and an acrylate generate a zwitterion in situ and it serves as an efficient catalyst for asymmetric reactions through a homogeneous ion‐pairing mode. This new catalytic system has been successfully applied to Mannich‐type reactions to give excellent results and it demonstrates a broad substrate scope. Such reactivity is not accessible with general organophosphine catalytic modes. Preliminary investigations into the mechanism are also presented.
Medical student perceptions of radiology use in anatomy teaching
Authors: Murphy Kevin P. , Crush Lee , O'Malley Eoin , Daly Fergus E. , Twomey Maria , O'Tuathaigh Colm M.P. , Maher Michael M. , Cryan John F. , O'Connor Owen J.
Published: December 2014

The use of radiology in the teaching of anatomy to medical students is gaining in popularity; however, there is wide variation in how and when radiology is introduced into the curriculum. The authors sought to investigate students' perceptions regarding methods used to depict and teach anatomy and effects of integrated radiology instruction on students' abilities to correctly identify imaging modalities and anatomical structures on radiological images. First‐year medical students completed questionnaires at the beginning and end of the first academic year that incorporated ten hours of radiologic anatomy teaching in the anatomy curriculum. Questions used a combination of Likert scales, rankings, and binary options. Students were tested on their ability to identify radiology modalities and anatomical structures on radiology images. Preresponse and postresponse rates were 93% (157/168) and 85% (136/160), respectively. Postmodule, 96.3% of students wanted the same or more radiology integration. Furthermore, 92.4% premodule and 96.2% postmodule agreed that “Radiology is important in medical undergraduate teaching.” Modality and structure identification scores significantly increased from 59.8% to 64.3% (P < 0.001) and from 47.4% to 71.2% (P < 0.001), respectively. The top three preferred teaching formats premodule and postmodule were (1) anatomy laboratory instruction, (2) interactive sessions combining radiology with anatomy, and (3) anatomy lectures. Postmodule, 38.3% of students were comfortable reviewing radiology images. Students were positive about integrating radiology into anatomy teaching and most students wanted at least the same level of assimilation but that it is used as an adjunct rather than primary method of teaching anatomy. Anat Sci Educ 8: 510–517. © 2014 American Association of Anatomists.
Beyond ethanol: a techno‐economic analysis of an integrated corn biorefinery for the production of hydrocarbon fuels and chemicals
Authors: Wang Kaige , Ou Longwen , Brown Tristan , Brown Robert C.
Published: December 2014

Dried distillers grains with solubles (DDGS) are potential feedstocks for the production of hydrocarbon fuels and chemicals from catalytic pyrolysis. This study evaluates the economic feasibility of a 2000‐metric‐ton‐corn‐per‐day integrated biorefinery with an add‐on facility processing corn DDGS to hydrocarbons. In addition to ethanol, the integrated facility would produce a wide range of hydrocarbons, including aromatics, olefins, and synthetic gasoline and diesel. The hydrocarbon products command a substantially higher market value than that of the pre‐processed DDGS: $109 million per year vs. $78 million per year. The add‐on DDGS conversion facility contributes an extra $152 million of capital investment compared with the stand‐alone corn ethanol production scenario. The operating costs for the integrated scenario are also higher than for the stand‐alone scenario, mainly due to increases in utilities, labor costs, and capital depreciation. The minimum fuel selling price (MFSP) for the integrated scenario is $2.27/gallon, which is comparable to the MFSP of $2.18/gallon for the stand‐alone scenario. Sensitivity analysis shows that the feedstock cost, hydrocarbon yield, and fixed capital investment have the greatest impacts on the MFSP. With the benefit of products diversity, the proposed integrated corn biorefinery may be competitive with conventional stand‐alone ethanol production. © 2014 Society of Chemical Industry and John Wiley & Sons, Ltd
Potentiometric detection in UPLC as an easy alternative to determine cocaine in biological samples
Authors: Daems Devin , van Nuijs Alexander L. N. , Covaci Adrian , Hamidi‐Asl Ezat , Van Camp Guy , Nagels Luc J.
Published: December 2014

The analytical methods which are often used for the determination of cocaine in complex biological matrices are a prescreening immunoassay and confirmation by chromatography combined with mass spectrometry. We suggest an ultra‐high‐pressure liquid chromatography combined with a potentiometric detector, as a fast and practical method to detect and quantify cocaine in biological samples. An adsorption/desorption model was used to investigate the usefulness of the potentiometric detector to determine cocaine in complex matrices. Detection limits of 6.3 ng mL−1 were obtained in plasma and urine, which is below the maximum residue limit (MRL) of 25 ng mL−1. A set of seven plasma samples and 10 urine samples were classified identically by both methods as exceeding the MRL or being inferior to it. The results obtained with the UPLC/potentiometric detection method were compared with the results obtained with the UPLC/MS method for samples spiked with varying cocaine concentrations. The intraclass correlation coefficient was 0.997 for serum (n =7) and 0.977 for urine (n =8). As liquid chromatography is an established technique, and as potentiometry is very simple and cost‐effective in terms of equipment, we believe that this method is potentially easy, inexpensive, fast and reliable. Copyright © 2014 John Wiley & Sons, Ltd.
Smoking and mortality after breast cancer diagnosis: the health and functioning in women study
Authors: Izano Monika , Satariano William A. , Hiatt Robert A. , Braithwaite Dejana
Published: December 2014

We examined the effect of smoking on long‐term mortality from breast cancer and other causes among a cohort of women with breast cancer. A total of 975 women diagnosed with breast cancer and aged 40–84 years were followed for a median follow‐up of 11 years in the U.S. Health and Functioning in Women (HFW) study. The impact of the individual smoking status and smoking intensity reported in the first few months following breast cancer diagnosis on the risk of mortality from breast cancer and other causes was examined using Cox proportional hazards models. In this study, former smoking was associated with increased risk of other‐cause mortality (hazard ratio [HR] = 1.47, 95% confidence interval [CI]: 1.13–1.90), and the risk doubled with increased intensity (HR for <50 pack‐years [py]: 1.36, 95% CI: 1.03–1.79; HR for ≥50 py: 2.45, 95% CI: 1.41–4.23). Current smoking (HR = 2.45, 95% CI: 1.81–3.32) and each additional 10 py smoked (HR = 1.16, 95% CI: 1.11–1.22) were associated with statistically significant increases in the risk of other‐cause mortality. The effect of current smoking on other‐cause mortality decreased with advancing stage and increasing body mass index (BMI). Breast cancer‐specific mortality was associated with current smoking of ≥50 py (HR = 2.36, 95% CI: 1.26–4.44), and each additional 10 py smoked (HR = 1.07, 95% CI: 1.01–1. 14). Current smoking, but not former smoking, was associated with increased risk of breast cancer‐specific mortality in women with local disease (HR = 2.32, 95% CI: 1.32–4.09), but not in those with regional and distant disease (HR = 1.10, 95% CI: 0.73–1.68). Our findings suggest that current smoking at the time of breast cancer diagnosis may be associated with increased risk of breast‐cancer specific and other‐cause mortality, whereas former smoking is associated with increased risk of other‐cause mortality. Smoking cessation at the time of diagnosis may lead to better prognosis among women with breast cancer.
Lithium–Air Batteries: Performance Interplays with Instability Factors
Authors: Ye Luhan , Lv Weiqiang , Cui Junyi , Liang Yachun , Wu Peng , Wang Xiaoning , He Han , Lin Senjun , Wang Wei , Dickerson James H. , He Weidong
Published: December 2014

Lithium–air batteries are considered to be promising electrochemical storage devices, due to their high specific energy density. However, instability limits their cyclic performance and rate capacity and also leads to a high overpotential; lithium–air batteries are typically characterized by capacity degradation and short cycle life. Such challenges prevent lithium–air batteries from entering and competing in the battery market. Electrodes, organic solvents, the interface between electrolyte and cathode, and ambient conditions have all been demonstrated to impact substantially the stability of the lithium–air battery. In this Minireview, we focus on electrode and electrolyte decomposition, side reactions, and physical mass transport in aprotic lithium–air batteries, as well as other types of lithium–air batteries, and aim to understand comprehensively their performance and association with instability factors.
Prediction of azeotropic behaviour by the inversion of functions from the plane to the plane
Authors: Guedes Aline L. , Moura Neto Francisco D. , Platt Gustavo M.
Published: December 2014

Azeotropy is a thermodynamic phenomenon where liquid and vapour coexisting phases have the same composition. In binary mixtures, the azeotropy calculation is represented by a 2 × 2 nonlinear system of algebraic equations with temperature (or pressure) and one molar fraction as unknowns. On rare occasions, this nonlinear system exhibits two solutions, characterizing a double azeotrope. In this work, we calculate double azeotropes with a geometry‐based methodology: the numerical inversion of functions from the plane to the plane. We present results for two mixtures where the double azeotropy phenomenon occurs: the system benzene + hexafluorobenzene and the system 1,1,1,2,3,4,4,5,5,5‐decafluoropentane + oxolane. The persistence of double azeotropes across different pressures is made clear by this global geometric approach. Moreover the vanishing of the existence of a pair of azeotropes is explained by the coalescence of them in just one, as can be easily understood from a global geometric viewpoint presented of the nonlinear function involved. The results indicate that this methodology can be a powerful tool for a better understanding of nonlinear algebraic systems in phase coexistence problems.
A computational fluid dynamics comparison between different outflow graft anastomosis locations of Left Ventricular Assist Device (LVAD) in a patient‐specific aortic model
Authors: Caruso Maria Vittoria , Gramigna Vera , Rossi Michele , Serraino Giuseppe Filiberto , Renzulli Attilio , Fragomeni Gionata
Published: December 2014

Left ventricular assist devices (LVADs) are mechanical supports used in case of heart failure. Little is known as the height of the anastomosis in aorta might influence the hemodynamic. The aim of the study was to evaluate the fluid dynamic behavior due to the outflow graft placement of a continuous flow LVAD in ascending aorta and to identify the insertion site with the best hemodynamic profile.

Computational fluid dynamic studies were carried out to analyze 4 different anastomosis locations in a patient‐specific aorta 3D model coupled with a lumped parameters model: 1 cm (case 1), 2 cm (case 2), 3 cm (case 3) and 4 cm (case 4) above the ST junction.

In cases 1 and 2, epiaortic vessels presented a steady flow, while in cases 3 and 4 the flow was whirling. Moreover, maximum velocity occurred before: brachiocephalic trunk (case 1), brachiocephalic and left carotid arteries (case 2), left carotid and left subclavian artery (case 3) and left subclavian vessel and upper wall of aortic arch (case 4). Maximum time averaged wall shear stress (TAWSS) was located in: the ascending aorta (cases 1 and 2), the inferior curvature of the arch (case 3); at the origin of epiaortic vessels (case 4). Furthermore, a flow recirculation (cases 1 and 2), a blood stagnation and chaotic flow (cases 3 and 4) occurred above the aortic valve.

The results suggested that the placement of the outflow graft at 2 cm above the ST junction gave the most favorable hemodynamic profile. Copyright © 2015 John Wiley & Sons, Ltd.
Enhanced Ferromagnetism in a Mn3C12N12H12 Sheet
Authors: Liu Junyi , Sun Qiang
Published: December 2014

Based on a recent experimental study on the Ni3C12S12 sheet [J. Am. Chem. Soc. 2013, 135, 2462] and a theoretical study on the Mn3C12S12 sheet [Nanoscale­ 2013, 5, 10404], by using density functional theory combined with a thermodynamic model, it is shown that when sulfur atoms are replaced by NH groups the resulting Mn3C12N12H12 sheet can exhibit strong ferromagnetism with a Curie temperature of 450 K. The enhanced ferromagnetism is due to two main factors: the reduced lattice constant and nitrogen is more effective in mediating magnetic couplings through p–d exchange interactions. Furthermore, it is also confirmed that the Mn3C12N12H12 sheet is kinetically and thermally stable, and displays half metallicity.
A power‐efficient 600‐mVpp voltage‐mode driver with independently matched pull‐up and pull‐down impedances
Authors: Bae Woorham , Jeong Deog‐Kyoon
Published: December 2014

In this study, a large‐swing, low‐power voltage‐mode driver with independently matched pull‐up and pull‐down impedances is proposed. To achieve large swing and constant impedances during a transition, a P‐over‐N structure is implemented with regulators calibrating the impedances. Two regulators are dedicated to matching the pull‐up and pull‐down impedances by regulating the supply voltages of the driver and predriver, respectively. Because background impedance calibration loops are adopted to track the process, voltage, and temperature (PVT) variations, the proposed driver can operate properly without additional calibration time. To reduce the power consumption of the calibration loops, scaled replicas of the actual driver are used. Moreover, an analysis of design optimization for the proposed driver is presented. The proposed driver was fabricated in 65‐nm CMOS technology and verified at a 5‐Gb/s data rate. Measurement results show that the proposed driver has a voltage swing of 600 mVpp and a horizontal eye opening of 0.5 UI. The prototype chip consumes 6 mW at a 1.0‐V supply. Copyright © 2014 John Wiley & Sons, Ltd.
Modeling and analysis of magnetically coupled resonant wireless power transfer system with rectifier bridge LED load
Authors: Lu Weiguo , Zhao Mao , Zhou Luowei , Iu Herbert H. C. , Zhao Junkai
Published: December 2014

The system of magnetically coupled resonant wireless power transfer (MCR‐WPT) for a rectifier bridge light‐emitting diode (LED) load is modeled, and its transmission characteristics for different LED arrays are analyzed and validated in this paper. On the basis of the derived equivalent steady‐state circuit model consisting of the high‐frequency alternating current source, the WPT networks and the rectifier bridge LED load, transmission efficiency and transmission distance related to the LED connection forms are obtained in theory. In our concerned scheme, the total power of LED arrays is chosen as its rated one so as to guarantee a rated current of each LED. More accurate system parameters are measuring, and some theoretical results for two feasible connection forms of LED arrays are validated in experiment. The theoretical and experimental results at the two working points are consistent approximately, which validates the feasibility of the derived equivalent circuit model of the concerned MCR‐WPT system. Copyright © 2014 John Wiley & Sons, Ltd.
Nonlinear Transport Processes in Non‐Ideal Media
Authors: Pavlov G. A. , Troshchiev Yu. V.
Published: December 2014

The theory of non‐linear transport is elaborated to determine the Burnett transport properties of non‐ideal multielement plasma and neutral systems. The procedure of the comparison of the phenomenological conservation equations of a continuous dense medium and the microscopic equations for dynamical variables operators in the form of the generalized nonlinear Langevin equations is used for the definition of these properties. In consequence, the microscopic expressions of transport coefficients corresponding to second order thermal disturbances (temperature, mass velocity, etc.) have been found in the long‐wavelength and low frequency limits of correlations functions. Situations are considered when the use of nonlinear transport characteristics (in the Burnett approximation) significantly affects the results of modeling of hydrodynamic processes in dense charged and neutral media. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Collective cell migration of the nephric duct requires FGF signaling
Authors: Attia Lital , Schneider Jenny , Yelin Ronit , Schultheiss Thomas M.
Published: December 2014

Background: During the course of development, the vertebrate nephric duct (ND) extends and migrates from the place of its initial formation, adjacent to the anterior somites, until it inserts into the bladder or cloaca in the posterior region of the embryo. The molecular mechanisms that guide ND migration are poorly understood. Results: A novel Gata3‐enhancer‐Gfp‐based chick embryo live imaging system was developed that permits documentation of ND migration at the individual cell level for the first time. FGF Receptors and FGF response genes are expressed in the ND, and FGF ligands are expressed in surrounding tissues. FGF receptor inhibition blocked nephric duct migration. Individual inhibitors of the Erk, p38, or Jnk pathways did not affect duct migration, but inhibition of all three pathways together did inhibit migration of the duct. A localized source of FGF8 placed adjacent to the nephric duct did not affect the duct migration path. Conclusions: FGF signaling acts as a “motor” that is required for duct migration, but other signals are needed to determine the directionality of the duct migration pathway. Developmental Dynamics 244:157–167, 2015. © 2014 Wiley Periodicals, Inc.
Using a Bayesian network model to assess ecological responses to hydrological factor interactions
Authors: Kath Jarrod M. , Le Brocque Andrew F. , Maron Martine
Published: December 2014

Interactions between environmental factors can dramatically influence the relationships between a species and its environment. However, multiple types of interaction are possible, and as such, some may be overlooked. We used a Bayesian network to model the response of a riparian tree species, Eucalyptus camaldulensis Dehnh., to the interactive influences of hydrological factors. We used a novel conceptual framework, which included not only synergistic and antagonistic interactions but also qualitative interactions (i.e. the effect of an environmental factor that switches from positive to negative or vice versa depending on the value of another factor). Synergistic, antagonistic and qualitative interactions were all detected in the response of E. camaldulensis to hydrological factor interactions. The predicted influence of environmental factors varied dramatically when interactions were considered. In some instances, the likelihood of a certain outcome differed by greater than 80% when interactions were considered. For example, the negative impact of grazing on E. camaldulensis was far greater in areas of deep groundwater relative to areas of shallow groundwater. Interactions also led to qualitatively different predictions (i.e. a qualitative interaction occurred). For example, frequent wetland inundation had a positive influence on tree vigour in wetlands minimally impacted by weirs, but a negative influence in wetlands close to weirs. Considering interactions may therefore substantially change understanding of ecohydrological relationships. Thinking of interactions between factors as potentially qualitative, and not only as synergistic and antagonistic, is likely to be important in situations where multiple management interventions are proposed. Copyright © 2014 John Wiley & Sons, Ltd.
Assessing Written Communication in Higher Education: Review and Recommendations for Next‐Generation Assessment
Authors: Sparks Jesse R. , Song Yi , Brantley Wyman , Liu Ou Lydia
Published: December 2014

Written communication is considered one of the most critical competencies for academic and career success, as evident in surveys of stakeholders from higher education and the workforce. Emphasis on writing skills suggests the need for next‐generation assessments of writing proficiency to inform curricular and instructional improvement. This article presents a comprehensive review of definitions of writing proficiency from key higher education and workforce frameworks; the strengths and weaknesses of existing assessments; and challenges related to designing, implementing, and interpreting such assessments. Consistent with extant frameworks, we propose an operational definition including 4 strands of skills: (a) social and rhetorical knowledge, (b) domain knowledge and conceptual strategies, (c) language use and conventions, and (d) the writing process. Measuring these aspects of writing requires multiple assessment formats (including selected‐response [SR] and constructed‐response [CR] tasks) to balance construct coverage and test reliability. Next‐generation assessments should balance authenticity (e.g., realistic writing tasks) and psychometric quality (e.g., desirable measurement properties), while providing institutions and faculty with actionable data. The review and operational definition presented here should serve as an important resource for institutions that seek to either adopt or design an assessment of students' writing proficiency.
Estimating Item Difficulty With Comparative Judgments
Authors: Attali Yigal , Saldivia Luis , Jackson Carol , Schuppan Fred , Wanamaker Wilbur
Published: December 2014

Previous investigations of the ability of content experts and test developers to estimate item difficulty have, for the most part, produced disappointing results. These investigations were based on a noncomparative method of independently rating the difficulty of items. In this article, we argue that, by eliciting comparative judgments of difficulty, judges can more accurately estimate item difficulties. In this study, judges from different backgrounds rank ordered the difficulty of SAT® mathematics items in sets of 7 items. Results showed that judges are reasonably successful in rank ordering several items in terms of difficulty, with little variability across judges and content areas. Simulations of a possible implementation of comparative judgments for difficulty estimation show that it is possible to achieve high correlations between true and estimated difficulties with relatively few comparisons. Implications of these results for the test development process are discussed.
Comparison of odour thresholds and odour qualities of the enantiomers of 4‐mercapto‐2‐alkanones and 4‐acetylthio‐2‐alkanones
Authors: Wakabayashi Motoko , Wakabayashi Hidehiko , Nörenberg Svenja , Kubota Kikue , Engel Karl‐Heinz
Published: December 2014

4‐Mercapto‐2‐alkanones constitute a class of naturally occurring polyfunctional thiols; 4‐mercapto‐2‐heptanone, for example, has been reported in cooked red bell pepper. The objective of this study was to determine the impact of the chain length on the odour thresholds and the odour qualities of the enantiomers of these chiral volatiles. 4‐Acetylthio‐2‐pentanone and 4‐acetylthio‐2‐hexanone and the corresponding 4‐mercapto‐2‐alkanones were synthesized by the addition of thioacetic acid to 3‐alkene‐2‐ones and subsequent lipase‐catalysed hydrolysis. The absolute configurations and the gas chromatography (GC) elution order of the enantiomers on a chiral stationary phase were determined on the basis of 1H NMR anisotropy effects in combination with lipase‐catalysed enantioselective hydrolysis. These compounds were included into a homologous series of 4‐mercapto‐2‐alkanones and 4‐acetylthio‐2‐alkanones exhibiting alkyl carbon chain lengths from 5 to 10. The odour thresholds of the enantiomers were compared using capillary gas chromatography‐olfactometry (GC‐O). The odour thresholds of the mercapto‐compounds were consistently lower than those of the corresponding acetylthio‐compounds. Both series of compounds exhibited minima of the odour thresholds at alkyl carbon chain lengths of 7 and 8, respectively. Odour thresholds of the (S)‐enantiomers of 4‐mercapto‐2‐hexanone and 4‐acetylthio‐2‐hexanone were significantly lower than those of the corresponding (R)‐enantiomers. The (S)‐enantiomers of the mercapto‐compounds had more fruity and pleasant notes than the (R)‐enantiomers. Although the number of judges was limited, the comparative data demonstrate the impact of the chain length on odour thresholds and odour qualities of members of a homologous series and underline the role of the configurations for the sensory properties of chiral volatiles. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of Water Transport on Swelling and Stresses in PFSA Membranes
Authors: Khattra N. S. , Santare M. H. , Karlsson A. M. , Schmiedel T. , Busby F. C.
Published: December 2014

The mechanical durability of membranes used in proton exchange membrane fuel cells (PEMFC) is directly linked to the stresses that evolve in the membrane during fuel cell operation. The stresses are primarily induced due to the swelling of the membrane as it absorbs water, within the mechanical constraints in the fuel cell assembly. Thus, in order to predict the membrane stresses, the water content in the perfluorosulphonic acid (PFSA) membranes is determined numerically via three different absorption models based on experimentally determined water uptake data from the literature. Two models are based on a single, humidity‐dependent Fickian transport coefficient for the bulk PFSA membrane. In the third, two transport properties are modeled to account for a possible difference in transport resistance between the bulk membrane and the outer surface. The membrane sorption behaviors characterized from these three models are then independently incorporated in a representative fuel cell finite element model and subjected to a standard relative humidity (RH) protocol designed for measuring mechanical durability of PEMFCs. The results show that the sorption behavior has a significant effect on the membrane stresses and therefore, may impact the lifetime of the membrane.
Precision‐guided sampling schedules for efficient T1ρ mapping
Authors: Johnson Casey P. , Thedens Daniel R. , Magnotta Vincent A.
Published: December 2014

Purpose

To describe, assess, and implement a simple precision estimation framework for optimization of spin‐lock time (TSL) sampling schedules for quantitative T1ρ mapping using a mono‐exponential signal model.

Materials and Methods

A method is described for estimating T1ρ precision, and a cost function based on the precision estimates is evaluated to determine efficient TSL sampling schedules. The validity of the framework was tested by imaging a phantom with various sampling schedules and comparing theoretical and experimental precision values. The method utility was demonstrated with in vivo T1ρ mapping of brain tissue using a similar procedure as the phantom experiment. To assist investigators, optimal sampling schedules are tabulated for various tissue types and an online calculator is implemented.

Results

Theoretical and experimental precision values followed similar trends for both the phantom and in vivo experiments. The mean absolute percentage error (MAPE) of theoretical estimates of T1ρ map signal‐to‐noise ratio (SNR) was typically 5% in the phantom experiment and 33% in the in vivo demonstration. In both experiments, optimal TSL schedules yielded greater T1ρ map SNR efficiency than typical schedules.

Conclusion

The framework can be used to improve the imaging efficiency of T1ρ mapping protocols and to guide selection of imaging parameters. J. Magn. Reson. Imaging 2015;41:242–250. © 2014 Wiley Periodicals, Inc.
In‐plane and out‐of‐plane defects of graphite bombarded by H, D and He investigated by atomic force and Raman microscopies
Authors: Pardanaud Cedric , Martin Celine , Cartry Gilles , Ahmad Ahmad , Schiesko Loic , Giacometti Gregory , Carrere Marcel , Roubin Pascale
Published: December 2014

Graphite samples exposed to H, D and He plasma at fluencies from 1016 to 1018 cm−2 have been investigated by means of atomic force and Raman microscopies. The ion energy was varied between 40 and 800 eV, and the ion incidence was either perpendicular (Highly Oriented Pyrolitic Graphite) or parallel (carbon/carbon composite) to the basal plane. When increasing the impinging ion energy, the growth of nanometric domes at the surface has been observed by atomic force microscopy and the incident kinetic energy has been found as the parameter determining their height. Two different Raman signatures related to (1) a graphitic nano‐crystalline component similar to that of a 1014 cm−2 bombarded 1‐, 2‐ and 3‐layer graphene, and to (2) an amorphous component, have been evidenced. Polarization studies have revealed that these components are related to regions with either in‐plane or out‐of‐plane disorder, coexisting in the material. These Raman studies have also revealed that both the defect–defect distance in the first case and the aromatic domain size in the second case are typically 1 nm. When the number of vacancies created in the material increases, the number of in‐plane defects decreases to the benefit of the out‐of‐plane defects. Copyright © 2014 John Wiley & Sons, Ltd.
Biophysical Controlling Factors in Upper Catchments and Braided Rivers in Drylands: The Case of a Marginal Graben of the Ethiopian Rift Valley
Authors: Demissie Biadgilgn , Frankl Amaury , Haile Mitiku , Nyssen Jan
Published: December 2014

The Raya Graben is a marginal graben of the Ethiopian Rift Valley located in North Ethiopia. The purpose of this study is to investigate the impacts of biophysical factors in the headwater catchments on the morphology of braided rivers in the graben bottom over the period between 1972 and 2010. In this study, 20 representative catchments on the escarpment were selected to analyse the relationship between the morphology (length and area) of the braided rivers in the graben bottom and the biophysical controls in upper catchments (vegetation cover, extremely degraded land, catchment area, compactness, and slope gradient in both the steep upper catchments and the gentle graben bottom). Landsat imagery was used to calculate the normalized difference vegetation index (NDVI), and to map vegetation cover and the total length of the braided rivers. Spot imagery available from Google Earth was used to quantify the total area of the braided rivers in 2005. In regression analyses, both length of braided rivers in the graben bottom (p < 0·0001, R2 = 0·549, n = 100) and area occupied by the braided rivers in the graben bottom (p = 0·0001, R2 = 0·585, n = 20) were positively correlated with upper catchment area. The NDVI in the upper catchments shows an increasing trend (R2 = 0·73, p = 0·067) over the last 40 years. The trend in the NDVI and the length of the braided rivers shows an inverse relationship. Hence, upper catchment area and vegetation cover are important factors of the morphology of braided rivers in drylands. Copyright © 2014 John Wiley & Sons, Ltd.
The Effect of Stabilizer on the Mechanical Response of Double‐Emulsion‐Templated Polymersomes
Authors: Jang Woo‐Sik , Park Seung Chul , Kim Miju , Doh Junsang , Lee Daeyeon , Hammer Daniel A.
Published: December 2014

Recent studies have shown that polymersomes templated by microfluidic double‐emulsion possess several advantages such as high monodispersity and encapsulation efficiency compared with those generated based on thin‐film rehydration and electroformation. Stabilizers, including bovine serum albumin (BSA) and polyvinyl alcohol (PVA), have been used to enhance the formation and stability of double emulsions that are used as templates for the generation of polymersomes. In this work, the effect of stabilizers on the mechanical response of double‐emulsion‐templated polymersomes using micropipette aspiration is investigated. It is demonstrated that the existence of stabilizers results in the inelastic response in poly­mersomes in the early stage of solvent removal. However, aged polymersomes that have little residual solvent show elastic behavior. Polymersomes prepared from PVA‐stabilized double emulsions have noticeably lower area expansion moduli than polymersomes prepared from stabilizer‐free and BSA‐stabilized double emulsions, suggesting that PVA is incorporated in the bilayer membrane of polymersomes.

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Der russische Kohlenbergbau im Jahr 2014
Authors: Hartlieb‐Wallthor Peter v.
Published: December 2014

Der Russland‐Ukraine‐Konflikt, dem sich auch deutsche Bergbauzulieferer nicht entziehen können, sorgt weiter für Verunsicherung. Für viele deutsche Bergbauzulieferer sind russischen Bergbaukonzerne und Schachtanlagen als gute Kunden seit vielen Jahren von besonderer Bedeutung. Die gute Nachricht ist, dass die dortige Kohleindustrie weiterhin einer nachhaltigen Aufrüstung und Modernisierung entgegensieht. Der Anteil der Kohle an der russischen Stromerzeugung beträgt 2014 über 25 %, Tendenz stark steigend. Russlands Technologiebedarf im Bergbaubereich kann für die deutschen Bergbauzulieferer eine gute Geschäftsgrundlage sein. Deutsche Bergbauconsultants und Fachfirmen kamen in der Vergangenheit als Lieferanten häufiger zum Zuge, wenn es um ganzheitliche Ansätze oder um technisch anspruchsvolle Lösungen ging.
Factors Associated with the Referral of Anxious Children to Mental Health Care: the Influence of Family Functioning, Parenting, Parental Anxiety and Child Impairment
Authors: Jongerden Loes , Simon Ellin , Bodden Denise H. M. , Dirksen Carmen D. , Bögels Susan M.
Published: December 2014

This study aims to identify factors that predict the mental health care referral of anxious children. In total, 249 children and families, aged 8–13 years, participated: 73 children were referred with anxiety disorders to mental health care [mean (M) age =10.28, standard deviation (SD) =1.35], 176 non‐referred anxious children recruited in primary schools (M age =9.94, SD =1.22). Child anxiety and other disorders were assessed with semi‐structured interviews. Child anxiety symptoms, behavioural problems, parental anxiety, the parenting styles overprotection, autonomy encouragement, rejection, and the family functioning dimensions control and relational functioning, were assessed with child, father and mother report on questionnaires. The summed interference rating of children's anxiety disorders was a predictor of referral, consistent over child and parent reports, but not comorbidity. Most family and parenting variables did not predict referral, nor differed between the referred and non‐referred sample. Contrary to our hypothesis, maternal self‐reported anxiety decreased the odds of referral and child reported parental autonomy granting increased, while child reported overprotection decreased the odds of referral. The impairment for the child due to the number and severity of their anxiety disorder(s) is, based on child, mother and father report associated with referral. This indicates that those who need it most, receive clinical treatment. Copyright © 2014 John Wiley & Sons, Ltd.
Isolation of Flavonoids and Triterpenoids from the Fruits of Alphitonia Neocaledonica and Evaluation of their Anti‐oxidant, Anti‐tyrosinase and Cytotoxic Activities
Authors: Muhammad Dima , Hubert Jane , Lalun Nathalie , Renault Jean‐Hugues , Bobichon Hélène , Nour Mohammed , Voutquenne‐Nazabadioko Laurence
Published: December 2014

Introduction

Alphitonia neocaledonica (Rhamnaceae) is an endemic tree of New Caledonia. Although three flavonoids have been identified in the leaves, the secondary metabolite profile of the fruits has never been investigated.

Objective

Phytochemical investigation of A. neocaledonica fruits and evaluation of their anti‐oxidant, anti‐tyrosinase and cytotoxic activities.

Methods

A hydromethanolic extract was fractionated by liquid–liquid extraction to obtain ethyl acetate and n‐butanolic fractions. The ethyl‐acetate‐soluble part was purified by silica‐gel column chromatography and high‐performance liquid chromatography (HPLC). The n‐butanol‐soluble part was fractionated by centrifugal partition extraction (CPE) and the collected fractions were further purified by centrifugal partition chromatography (CPC) and HPLC. The chemical structures of the purified compounds were identified by nuclear magnetic resonance and mass spectrometry.

Results

Three triterpenoids and one flavonoid were isolated from the ethyl‐acetate‐soluble part. Fractions enriched in triterpenoids, flavonoids and catechin derivatives were obtained from the n‐butanol‐soluble part. Gallocatechin and flavonoids were obtained as pure compounds by further CPC and HPLC purification. The n‐butanolic‐soluble part showed anti‐oxidant and anti‐tyrosinase activities due to the presence of tannins and gallocatechin. The triterpenoid alphitolic acid showed a moderate cytotoxic activity against KB cell line (median inhibition concentration = 8.5 μM).

Conclusions

Nine known compounds including three triterpenes, five flavonoids and (+) gallocatechin, as well as a new 3‐O‐(6‐E‐feruloyl)‐β‐D‐glucopyranosyl‐(1 → 2)‐[β‐D‐xylopyranosyl‐(1 → 2)‐]α‐L‐rhamnopyranosyl‐quercetin, were isolated from A. neocaledonia fruits. The hydromethanolic extract possesses a potential cytotoxic activity due to the presence of triterpenes, and it can also be valuable as a cosmetic ingredient for its anti‐oxidant and anti‐tyrosinase activities. Copyright © 2014 John Wiley & Sons, Ltd.
Qualitative and Quantitative Analysis of Potentilla fulgens Roots by NMR, Matrix‐assisted Laser Desorption/Ionisation with Time‐of‐Flight MS, Electrospray Ionisation MS/MS and HPLC/UV
Authors: Choudhary Alka , Radhika Manukonda , Chatterjee Anupam , Banerjee Uttam Chand , Singh Inder Pal
Published: December 2014

Introduction

Potentilla fulgens is a commonly used folk medicine by natives of northeast India, Nepal and Bhutan and is rich in polyphenolic and triterpene constituents.

Objective

To identify chemomarkers in the roots of P. fulgens by an interplay of 13C‐NMR, matrix‐assisted laser desorption/ionisation with time‐of‐flight (MALDI/TOF) MS, electrospray ionisation (ESI) MS/MS and HPLC/UV.

Material and methods

The 13C‐NMR spectrum of crude methanolic extract was recorded in deuterated dimethyl sulphoxide. For MALDI/TOF/MS analysis, 2,5‐dihydroxybenzoic acid was used as the matrix. For determination of chemical constituents, two independent simple isocratic HPLC/UV methods for monomeric/oligomeric flavanols and triterpene acids were developed and validated.

Results

The 13C‐NMR spectrum of the methanolic extract indicated the presence of B‐type oligomeric polyphenolics containing mainly epicatechin/catechin (epicat/cat) and epiafzelechin/afzelechin (epiafz/afz) as the monomeric units. Several isobaric monomeric and oligomeric flavanols and triterpenoids were tentatively identified by MALDI/TOF/MS and ESI/MS/MS. Fourteen compounds (four monomeric and five dimeric flavanols and five triterpene acids) were isolated using repeated column chromatography and semi‐preparative HPLC, and were quantitated using HPLC/UV.

Conclusion

It is evident from these analyses that roots of P. fulgens contain flavans, including oligomeric flavanols, as major constituents followed by triterpene acids. The methods described can be applied to other Potentilla species to identify their constituents. Copyright © 2014 John Wiley & Sons, Ltd.