bluuebunny/crossref_metadata_2025 huggingface dataset:
Continuous‐Flow Asymmetric Hydrogenation of the β‐Keto Ester Methyl Propionylacetate in Ionic Liquid–Supercritical Carbon Dioxide Biphasic Systems
Authors: Theuerkauf Jens , Franciò Giancarlo , Leitner Walter
Published: January 2013

A continuous‐flow process for the asymmetric hydrogenation of methyl propionylacetate as a prototypical β‐keto ester in a biphasic system of ionic liquid and supercritical carbon dioxide (scCO2) is presented. An established ruthenium/2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl (BINAP) catalyst was immobilised in an imidazolium‐based ionic liquid while scCO2 was used as mobile phase transporting reactants in and products out of the reactor. The use of acidic additives led to significantly higher reaction rates and enhanced catalyst stability albeit at slightly reduced enantioselectivity. High single pass conversions (>90%) and good enantioselectivity (80–82% ee) were achieved in the first 80 h. The initial catalyst activity was retained to 91% after 100 h and to 69% after 150 h time‐on‐stream, whereas the enantioselectivity remained practically constant during the entire process. A total turnover number of ∼21,000 and an averaged space‐time yield (STYav) of 149 g L−1 h−1 were reached in a long‐term experiment. No ruthenium and phosphorus contaminants could be detected via inductively coupled plasma optical emission spectrometry (ICP‐OES) in the product stream and almost quantitative retention by the analysis of the stationary phase was confirmed. A comparison between batch‐wise and continuous‐flow operation on the basis of these data is provided.
The Determinants of Ownership Structure: Evidence from Brazilian Agricultural Cooperatives
Authors: de Moura Costa Davi R. , Chaddad Fabio , Furquim de Azevedo Paulo
Published: January 2013

The separation of ownership and control observed in large corporations is common to other organizations such as large professional partnerships, financial mutuals, nonprofits, and cooperatives. This separation gives rise to control and influence cost problems in cooperatives. However, it is not observed in all Brazilian agricultural cooperatives, where certain members have both residual claim and formal control rights. In this article, we examine the allocation of decision management and control rights and the determinants of ownership structure in a sample of Brazilian agricultural cooperatives. Using survey data, we employ multivariate regression techniques to empirically investigate the factors determining the allocation of ownership rights and the separation of ownership and control. Our findings do not lend strong support to agency theory, but they help inform research seeking to shed light on the determinants of decision rights allocation in agricultural cooperatives. [EconLit classification: Q130].
Cooperative CEO Identity and Efficient Governance: Member or Outside CEO?
Authors: Liang Qiao , Hendrikse George
Published: January 2013

A principal‐agent model is formulated to capture the efficiency of cooperatives with a member CEO and cooperatives with an employed outsider as CEO. Results of the model show that the incentive strength regarding the member CEO is stronger compared to that of the outside CEO in order to shift some effort of the member CEO from individual farming into the task of adding value to the cooperative enterprise. A cooperative with a member CEO is uniquely efficient when upstream and downstream tasks are substitutes to a certain extent, or complements. When the tasks are substitutes, the efficient CEO identity depends on the strength of the substitution effect and the difference of the marginal productivities between the two tasks. The scope of cooperatives with a member CEO being efficient becomes smaller when the substitution effect is at an intermediate level or the productivity difference between the two tasks is limited. [Econ Lit classification: D210, Q130].
Application of shear thickening fluid in ultra high molecular weight polyethylene fabric
Authors: Sun Liang‐Liang , Xiong Dang‐Sheng , Xu Cai‐Yun
Published: January 2013

An advanced stab‐resistant material composed of shear thickening fluid (STF) and ultra high molecular weight polyethylene (UHMWPE) fabric was investigated. STF was prepared by dispersing nanosilica (SiO2) into ethylene glycol. The shear thickening behavior of STF with the increase of the shear rate was observed by PhysicaMCR301. STF/UHMWPE composite fabric was synthesized by impregnating UHMWPE fabric in STF dilution. Stab resistant experiment was conducted on a self‐made stab test machine with knife and spike as stab tool. The results demonstrate that the stab resistant property of the UHMWPE fabric is greatly improved by impregnating STF. The stab resistant property is greatly increased with the increase of mass fraction of silica in STF. Especially, when the mass fraction of SiO2 in STF is 38%, the stab resistance force and energy absorption of STF/UHMWPE are optimal for knife and spike threats. With the same stab resistant properties, the flexibility of UHMWPE fabric impregnated with STF is higher than that of the neat fabric. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Thermomechanical and chemorheology properties of a thermosetting acrylic/melamine clearcoat modified with a hyperbranched polymer
Authors: Yari Hossein , Mohseni Mohsen , Ranjbar Zahra
Published: January 2013

The work presented here aims at studying the thermomechanical and chemorheological properties of an automotive clearcoat containing an acrylic/melamine resin modified with a hyperbranched poly ester‐amide (HBP) additive. Rheological experiments were conducted at ambient (25°C) and curing temperature (140°C). Dynamic mechanical thermal analysis and hardness measurements were performed to reveal the influence of HBP content on the behavior of the cured samples. It was found that the viscosity of the resin containing HBP samples considerably decreased. Although curing degree and mechanical properties were improved at low HBP loadings, a reverse effect was seen at higher contents. Dynamic rheological results during curing showed that although low amount of HBP resulted in an early gel point (GP), higher HBP loading postponed the GP. This loading‐dependent behavior was explained by the influence of HBP on viscosity and reactivity of the system on which the curing performance was influenced oppositely. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Electrospun nanofiber‐coated separator membranes for lithium‐ion rechargeable batteries
Authors: Lee Hun , Alcoutlabi Mataz , Watson Jill V. , Zhang Xiangwu
Published: January 2013

Nanofiber‐coated composite membranes were prepared by electrospinning polyvinylidene fluoride‐co‐chlorotrifluoroethylene (PVDF‐co‐CTFE) and PVDF‐co‐CTFE/polyvinylidene fluoride‐co‐hexafluoropropylene (PVDF‐co‐HFP) onto six different Celgard® microporous battery separator membranes. Application of a PVDF‐based copolymer nanofiber coating onto the surface of the battery separator membrane provides a method for improving the electrolyte absorption of the separator and the separator‐electrode adhesion. Peel tests showed that both PVDF‐co‐CTFE and PVDF‐co‐CTFE/PVDF‐co‐HFP nanofiber coatings have comparable adhesion to the membrane substrates. Electrolyte uptake capacity was investigated by soaking the nanofiber‐coated membranes in a liquid electrolyte solution. PVDF‐co‐CTFE and PVDF‐co‐CTFE/PVDF‐co‐HFP nanofiber‐coated membranes exhibited higher electrolyte uptake capacities than uncoated membranes. It was also found that PVDF‐co‐CTFE nanofiber‐coated membranes have higher electrolyte uptakes than PVDF‐co‐CTFE/PVDF‐co‐HFP nanofiber‐coated membranes due to the smaller diameters of PVDF‐co‐CTFE nanofibers and higher polarity of PVDF‐co‐CTFE. The separator–electrode adhesion properties were also investigated. Results showed PVDF‐co‐CTFE and PVDF‐co‐CTFE/PVDF‐co‐HFP nanofiber coatings improved the adhesion of all six membrane substrates to the electrode. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Miscibility of natural polyhydroxyalkanoate blend with controllable material properties
Authors: Tanadchangsaeng Nuttapol , Yu Jian
Published: January 2013

Polyhydroxyalkanoate (PHA) copolyesters were synthesized by Cupriavidus necator cells in continuous feeding of cosubstrates. During the PHA accumulation phase, the composition of 3‐hydroxybutyrate (3HB), 3‐hydroxyvalerate (3HV), and 4‐hydroxyvalerate (4HV) of the copolyesters changed with time, resulting in a change in their miscibility. The as‐produced PHA finally became a miscible blend of copolymers with a broad chemical composition distribution. The good miscibility and low crystallinity of the natural P(3HB‐co‐3HV‐co‐4HV) blend lead to a remarkable increase in ductility and elongation at break. It indicates that the material properties of copolyesters can be tailored via feeding control of cosubstrates. It was also found that the fractions of natural PHA blend exhibited distinctive thermal behavior and the overall behavior of the as‐produced PHA blend was primarily dependent on a fraction of high 3HB content. The material properties of a PHA blend are therefore not determined by its overall chemical composition but more likely by the combined effect of individual copolyesters or fractions. Moreover, the degree of X‐ray crystallinity of random P(3HB‐co‐3HV‐co‐4HV) blend declined significantly with the increase of 3HV and 4HV content, in contrast to the high crystallinity of well‐known P(3HB‐co‐3HV) copolyesters. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Vision‐Based Tracking and Position Estimation of Moving Targets for Unmanned Helicopter Systems
Authors: Lin Chien‐Hong , Hsiao Fu‐Yuen , Hsiao Fei‐Bin
Published: January 2013

The primary goal of this study is to track a ground‐moving target using a machine‐vision system installed on an unmanned helicopter, and to estimate its position if the target becomes unobservable. The machine‐vision system is accomplished using real‐time color images obtained from a charge‐coupled device (CCD) camera mounted on a computer‐controlled gimbaled system that can pitch and yaw. To avoid real‐time image‐tracking failure resulting from a moving target becoming concealed, the Kalman filtering technique is applied to predict the target's follow‐on position, so that the camera can continuously track the target. The entire system is initially tested on the ground and then mounted on a helicopter for in‐flight testing. The following three cases are shown in the flight tests: (1) an uncovered static target; (2) a moving visible target; and (3) a target that moves in a straight line at a constant speed and becomes temporarily concealed. The vision‐based tracking system with the developed algorithm is successfully applied in all three cases.
Developments in Direct CH Arylation of (Hetero)Arenes under Microwave Irradiation
Authors: Sharma Abhishek , Vacchani Dipak , Van der Eycken Erik
Published: January 2013

This minireview describes the progress made in the development of direct CH arylation approaches through the application of focused microwave irradiation. The synergistic combination of microwave‐assisted techniques with the rapidly evolving domain of CH arylation has opened new vistas in the efficient synthesis of a diverse array of biologically important (hetero)arenes.
Mechanistic Studies on the Roles of the Oxidant and Hydrogen Bonding in Determining the Selectivity in Alkene Oxidation in the Presence of Molybdenum Catalysts
Authors: Chandra Prakash , Pandhare Swati L. , Umbarkar Shubhangi B. , Dongare Mohan K. , Vanka Kumar
Published: January 2013

When the molybdenum oxo(peroxo) acetylide complex [CpMo(OO)(O)CCPh] is used as a catalyst for the oxidation of olefins, completely different product selectivity is obtained depending on the oxidant employed. When tert‐butyl hydroperoxide (TBHP, 5.5 M) in dodecane is used as the oxidant for the oxidation of cyclohexene, cyclohexene oxide is formed with high selectivity. However, when H2O2 is used as the oxidant, the corresponding cis‐1,2‐diol is formed as the major product. Calculations performed by using density functional theory revealed the nature of the different competing mechanisms operating during the catalysis process and also provided an insight into the influence of the oxidant and hydrogen bonding on the catalysis process. The mechanistic investigations can therefore serve as a guide in the design of molybdenum‐based catalysts for the oxidation of olefins.
Design and Synthesis of a New Family of Fluorinated Liquid Crystals
Authors: Nenajdenko Valentine G. , Goldberg Aleksey A. , Muzalevskiy Vasily M. , Balenkova Elizabeth S. , Shastin Aleksey V.
Published: January 2013

A convenient and simple three‐step pathway to the new family of CF2CF2S‐bridged alkanes and CF2S‐, CF2O‐bridged alkenes and alkynes was elaborated by using catalytic olefination reaction as a key step of the synthetic sequence. The obtained compounds revealed attractive liquid crystalline characteristics.
Cultural legacies, fire ecology, and environmental change in the Stone Country of Arnhem Land and Kakadu National Park, Australia
Authors: Trauernicht Clay , Murphy Brett P. , Tangalin Natalia , Bowman David M. J. S.
Published: January 2013

We use the fire ecology and biogeographical patterns of Callitris intratropica, a fire‐sensitive conifer, and the Asian water buffalo (Bubalus bubalis), an introduced mega‐herbivore, to examine the hypothesis that the continuation of Aboriginal burning and cultural integration of buffalo contribute to greater savanna heterogeneity and diversity in central Arnhem Land (CAL) than Kakadu National Park (KNP). The ‘Stone Country’ of the Arnhem Plateau, extending from KNP to CAL, is a globally renowned social–ecological system, managed for millennia by Bininj‐Kunwok Aboriginal clans. Regional species declines have been attributed to the cessation of patchy burning by Aborigines. Whereas the KNP Stone Country is a modern wilderness, managed through prescribed burning and buffalo eradication, CAL remains a stronghold for Aboriginal management where buffalo have been culturally integrated. We surveyed the plant community and the presence of buffalo tracks among intact and fire‐damaged C. intratropica groves and the savanna matrix in KNP and CAL. Aerial surveys of C. intratropica grove condition were used to examine the composition of savanna vegetation across the Stone Country. The plant community in intact C. intratropica groves had higher stem counts of shrubs and small trees and higher proportions of fire‐sensitive plant species than degraded groves and the savanna matrix. A higher proportion of intact C. intratropica groves in CAL therefore indicated greater gamma diversity and habitat heterogeneity than the KNP Stone Country. Interactions among buffalo, fire, and C. intratropica suggested that buffalo also contributed to these patterns. Our results suggest linkages between ecological and cultural integrity at broad spatial scales across a complex landscape. Buffalo may provide a tool for mitigating destructive fires; however, their interactions require further study. Sustainability in the Stone Country depends upon adaptive management that rehabilitates the coupling of indigenous culture, disturbance, and natural resources.
Quantitative structural characterization and thermal properties of birch lignins after auto‐catalyzed organosolv pretreatment and enzymatic hydrolysis
Authors: Wen Jia‐Long , Xue Bai‐Liang , Sun Shao‐Long , Sun Run‐Cang
Published: January 2013

BACKGROUND

To achieve the goals of economically feasible auto‐catalyzed organosolv pretreatments in bioethanol production, chemical conversion of the isolated lignin is needed. However, the structures and properties of lignin molecules produced after pretreatment have not been thoroughly investigated before its effective utilization.

RESULTS

The study focused on the auto‐catalyzed ethanol–water pretreatment of southwest birch, with the aim to clarify the structural transformations of birch lignin after pretreatment. Chemical structural elucidation of the isolated lignins was performed using multiple NMR methodologies (31P‐, 13C‐ and 2D‐HSQC NMR techniques). Results showed that the amount of β‐O‐4 linkages decreased in the order of AEOL (auto‐catalyzed ethanol organosolv lignin) < EHLP (enzymatic hydrolysis lignin, pretreated) < EHLU (unpretreated). The homolytic cleavage of β‐O‐4 linkages resulted in an increase of free phenolic hydroxyl groups and carboxylic acids in AEOL and EHLP compared with that of EHLU. In addition, α‐ethoxylation was the only modification in the auto‐catalyzed ethanol organosolv pretreatment (AEOP). Moreover, the thermal stability of the lignin samples is related to its inherent and condensed structures.

CONCLUSIONS

These findings would facilitate the further utilization of lignin as starting material for developing value‐added products in chemical and catalytic process. © 2013 Society of Chemical Industry
Diagnostic criterion to distinguish between incomplete and complete discoid lateral meniscus on MRI
Authors: Choi Sang‐Hee , Shin Kyung Eun , Chang Moon Jong , Woo Sook Young , Lee Sang Hak
Published: January 2013

Purpose

To determine a new cutoff value that can further distinguish between the incomplete and complete discoid lateral meniscus (DLM).

Materials and Methods

Twenty‐one cases of incomplete DLM and 42 cases of complete DLM without tear were included. In all, 105 patients with normal lateral menisci were included as a control group. We measured the ratio of the shortest width of the lateral meniscus to the longest width of the tibia (ratio 1) and the ratio of the shortest width of the medial meniscus to the shortest width of the lateral meniscus (ratio 2).

Results

By applying a cutoff value of ratio 1 as 0.32 between two incomplete and complete DLM groups, the proportion of the complete and incomplete DLM diagnosed cases among the true cases were 84% and 94%, respectively. By applying a cutoff value of ratio 2 as 0.40 between two incomplete and complete DLM groups, the proportion of the complete and incomplete DLM diagnosed cases among the true cases were 84% and 75%, respectively.

Conclusion

A cutoff value of 0.32 using the ratio of the shortest width of the lateral meniscus and the longest width of the tibia are probably useful to help distinguish between complete DLM and incomplete DLM. Additionally, the new ratio using the width of the medial meniscus is also useful to improve distinguishing between the types of DLM. J. Magn. Reson. Imaging 2013;38:417–421. © 2013 Wiley Periodicals, Inc.
Combined parallel and partial fourier MR reconstruction for accelerated 8‐channel hyperpolarized carbon‐13 in vivo magnetic resonance Spectroscopic imaging (MRSI)
Authors: Ohliger Michael A. , Larson Peder E.Z. , Bok Robert A. , Shin Peter , Hu Simon , Tropp James , Robb Fraser , Carvajal Lucas , Nelson Sarah J. , Kurhanewicz John , Vigneron Daniel B.
Published: January 2013

Purpose:

To implement and evaluate combined parallel magnetic resonance imaging (MRI) and partial Fourier acquisition and reconstruction for rapid hyperpolarized carbon‐13 (13C) spectroscopic imaging. Short acquisition times mitigate hyperpolarized signal losses that occur due to T1 decay, metabolism, and radiofrequency (RF) saturation. Human applications additionally require rapid imaging to permit breath‐holding and to minimize the effects of physiologic motion.

Materials and Methods:

Numerical simulations were employed to validate and characterize the reconstruction. In vivo MR spectroscopic images were obtained from a rat following injection of hyperpolarized 13C pyruvate using an 8‐channel array of carbon‐tuned receive elements.

Results:

For small spectroscopic matrix sizes, combined parallel imaging and partial Fourier undersampling resulted primarily in decreased spatial resolution, with relatively less visible spatial aliasing. Parallel reconstruction qualitatively restored lost image detail, although some pixel spectra had persistent numerical error. With this technique, a 30 × 10 × 16 matrix of 4800 3D MR spectroscopy imaging voxels from a whole rat with isotropic 8 mm3 resolution was acquired within 11 seconds.

Conclusion:

Parallel MRI and partial Fourier acquisitions can provide the shorter imaging times and wider spatial coverage that will be necessary as hyperpolarized 13C techniques move toward human clinical applications. J. Magn. Reson. Imaging 2013;38:701–713. © 2013 Wiley Periodicals, Inc.
Noninvasive visualization of endoleaks after endovascular aortic aneurysm repair through unenhanced MRI with motion‐sensitized driven equilibrium preparation: Phantom experiments
Authors: Saida Tsukasa , Mori Kensaku , Yabe Hitoshi , Shindo Masashi , Nasu Katsuhiro , Shiigai Masanari , Takahashi Hideto , Minami Manabu
Published: January 2013

Purpose:

To optimize imaging parameters for balanced turbo field echo (BTFE) sequence combined with motion‐sensitized driven equilibrium (MSDE) preparation for endoleak detection and type classification in phantom experiments.

Materials and Methods:

We prepared four phantoms: a pulsatile flow generator with an aortic aneurysm model simulating no endoleak, and a type‐1, type‐2, and type‐3 endoleak. Throughout the experiments, MSDE‐BTFE images with and without flow suppression were obtained at 1.5 T and subtraction images were used for image evaluation. The no‐endoleak phantom was imaged using different MSDE‐BTFE sequences to optimize the k‐space trajectory and evaluate the use of electrocardiogram gating. The relative contrast between flowing saline and background was calculated. Then all phantoms were imaged to determine the optimal velocity encoding (VENC) for endoleak detection and type classification. Three independent observers performed the image evaluation. Consistencies between the interpreted and true results were analyzed using kappa statistics.

Results:

The 3D low‐high k‐space trajectory with electrocardiogram gating provided the highest relative contrast. Low VENCs of 2–10 cm/s and high VENCs of 20 cm/s showed perfect consistency in endoleaks detection and type classification, respectively.

Conclusion:

MSDE‐BTFE sequences of appropriate VENCs has potential for endoleak detection and type classification, without contrast material. J. Magn. Reson. Imaging 2013;38:714–721. © 2013 Wiley Periodicals, Inc.
A fast protocol for infarct quantification in mice
Authors: Buonincontri Guido , Methner Carmen , Krieg Thomas , Carpenter T. Adrian , Sawiak Stephen J.
Published: January 2013

Purpose

To demonstrate and validate a late gadolinium enhancement (LGE) imaging protocol, optimized for tissue viability assessment in interventional mouse models of myocardial infarction.

Materials and Methods

The method uses an efficient sampling scheme using multiple slices in a single heartbeat interleaving slice packages between alternate TRs. Sampling multiple slices instead of multiple echoes or multiple k‐lines achieves higher SNR efficiency, and images covering the whole heart can be obtained in 3 min. Saturation effects are exploited for an optimum compromise between contrast and speed.

Results

The images obtained show high hyperenhancement with good contrast‐to‐noise. It is shown that inversion time optimization can be reliably omitted with this scheme, and that measured infarct sizes correlate well with histological measures.

Conclusion

Our protocol offers a new efficient tool for the measurement of infarct size in mouse models of heart disease. J. Magn. Reson. Imaging 2013;38:468–473. © 2012 Wiley Periodicals, Inc.
Study of near‐symmetric cyclodextrins by compressed sensing 2D NMR
Authors: Misiak Maria , Koźmiński Wiktor , Chmurski Kazimierz , Kazimierczuk Krzysztof
Published: January 2013

The compressed sensing NMR (CS‐NMR) is an approach to processing of nonuniformly sampled NMR data. Its idea is to introduce minimal lp‐norm (0 < p ≤ 1) constraint to a penalty function used in a reconstruction algorithm. Here, we demonstrate that 2D CS‐NMR spectra allow the full spectral assignment of near‐symmetric β‐cyclodextrin derivatives (mono‐modified at the C6 position). The application of CS‐NMR ensures experimental time saving and the resolution improvement, necessary because of very low chemical shift dispersion. In the overnight experimental time, the set of properly resolved 2D NMR spectra required for the unambiguous assignment of mono(6‐deoxy‐6‐(1‐1,2,3‐triazo‐4‐yl)‐1‐propane‐3‐O‐(phenyl)) β‐cyclodextrin was obtained. The highly resolved HSQC spectrum was reconstructed from 5.12% of the data. Moreover, reconstructed 2D HSQC–TOCSY spectrum yielded information about the correlations within one sugar unit, and 2D HSQC–NOESY technique allowed the sequential assignment of the glucosidic units. Copyright © 2013 John Wiley & Sons, Ltd.
Extraction of recoverable and permanent trapped charge resulting from negative bias temperature instability
Authors: Nguyen D. D. , Kouhestani C. , Kambour K. E. , Hjalmarson H. P. , Devine R. A. B.
Published: January 2013

We have studied defect charging and discharging resulting from negative bias temperature instability in nitrided SiO2 gate insulator field effect transistors. Using pseudo‐DC and pulsed stressing methods, we are able to extract at least three individual components associated with a) interface states at the semiconductor/insulator boundary, b) dynamically recoverable positive charging in the “bulk” of the insulator, and c) positive charge in the insulator which can be “eliminated” by application of a positive electric field across the insulator. It is argued that the charge variation in c) in fact arises via a charge neutralization process involving electron capture at switching traps and that this process can be simply reversed using a small negative field. The important role played by neutral oxygen vacancies (O3≡Si‐Si≡O3) and/or their variants involving partial N substitutions is emphasized. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling rare‐earth doped BaMgF4: a potential laser material
Authors: Littleford Thomas E. , Jackson Robert A. , Read Mark S. D.
Published: January 2013

Solid‐state optical materials are a continuing field of study that has many important applications including lasers. BaMgF4 is one material has been studied in detail however, no studies into the surface properties or crystal morphology have been carried out. This paper summarizes the key findings of a bulk study into the material and extends it to consider the morphology of BaMgF4 before looking at the segregation of rare earth dopants defect clusters to the low index surfaces. It is shown that there is strong segregation to all of the three morphology‐dominating surfaces. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Conjugate gradients versus multigrid solvers for diffusion‐based correlation models in data assimilation
Authors: Gratton S. , Toint P. L. , Tshimanga J.
Published: January 2013

This article provides a theoretical and experimental comparison between conjugate gradients and multigrid, two iterative schemes for solving linear systems, in the context of applying diffusion‐based correlation models in data assimilation. In this context, a large number of such systems has to be (approximately) solved if the implicit mode is chosen for integrating the involved diffusion equation over pseudo‐time, thereby making their efficient handling crucial for practical performance. It is shown that the multigrid approach has a significant advantage, especially for larger correlation lengths and/or large problem sizes.
The European Union: the polycentric climate policy leader?
Authors: Rayner Tim , Jordan Andrew
Published: January 2013

The European Union's (EU) claims to be a leader in international climate policy are well known. Since the early 1990s, a rich and vibrant academic literature has analyzed the internal sources and international consequences of its leadership aspirations, especially in relation to the challenges of mitigation. More recently, attention has turned to adaptation policy. The literature highlights how policy actors have successfully exploited many of the opportunities afforded by the EU's ‘polycentric’ form, while minimizing its downsides, but that acute challenges lie ahead, particularly if a strong global‐level framework remains elusive. It has continually underlined the fact that the EU's climate policy activities have enormous relevance well beyond European borders. Both in terms of its role as a driver of international policy and a source of transferable policy lessons on how to govern in ‘polycentric’ settings, appreciating the EU's experience is vital for those seeking to understand the governance of climate change, both within and between states. WIREs Clim Change 2013, 4:75–90. doi: 10.1002/wcc.205

This article is categorized under:

Policy and Governance > Multilevel and Transnational Climate Change Governance
Temperature Dependent Jahn‐Teller Distortion in the Prussian Blue Analogue Cu0.47Ni0.48Mn0.55[Fe(CN)6]·7.8H2O
Authors: Liu Min , Zhou Jian , Xu Ming‐Xiang
Published: January 2013

The Jahn‐Teller distortion properties of Cu0.47Ni0.48Mn0.55[Fe(CN)6]·7.8H2O were studied by powder X‐ray diffraction measurements in the temperature region from 80 to 298 K. In the cooling process, a new peak labeled “a” near the (220) peak appears at 110 K. Conversely, as the sample is warmed to 200 K, this peak disappears. The new peak “a” is attributed to a slight elongation by Jahn‐Teller distorted Cu2+ ions. The structural distortion is relatively little, and thus, the compound undergoes no formal phase change occurs with the temperature varied. Temperature dependent Jahn‐Teller distortion was directly observed in the multi‐metal prussian blue analogue Cu0.47Ni0.48Mn0.55[Fe(CN)6]·7.8H2O.
Suspensions of Iron Oxide Nanoparticles Stabilized by Anionic Surfactants
Authors: Wang Ziheng , Lam Albert , Acosta Edgar
Published: January 2013

Two common anionic surfactants, sodium oleate (SO) and sodium dodecyl benzene sulfonate (SDBS) were used to re‐suspend iron oxide nanoparticles in aqueous solutions. At certain SO concentrations, the SO formulations produced highly stable suspensions. In contrast, SDBS‐stabilized nanoparticles exhibited poor stability at all concentrations. The adsorption isotherm of SO on iron oxide nanoparticles revealed that stable suspensions were obtained when the equilibrium SO concentration (after adsorption) reached its critical micelle concentration (CMC). At this “optimal” condition, the maximum SO adsorption was reached, and the zeta‐potential of the particles was highly negative (∼ −50 mV). According to the SO isotherm, this optimal formulation coincided with the formation of a highly compact SO bilayer. The SDBS isotherm, on the other hand, revealed that SDBS is not strongly adsorbed on the surface of iron oxide nanoparticles and that is likely that a patchy, loosely packed bilayer, is formed on the surface of the iron oxide nanoparticles when the equilibrium SDBS concentration reaches its CMC. The DLVO theory confirmed the connection between formulation conditions and the corresponding stability. This works confirmed that the formation of a surfactant bilayer is an important element in producing stable nanoparticle suspensions with anionic surfactants. It was also confirmed that for anionic surfactants, electrostatic repulsions are an important factor in establishing an energy barrier against flocculation. This work also introduced two more elements into the design of nanoparticle suspensions. The first element is that, in order to ensure the best possible dispersion, the surfactant concentration in solution at equilibrium with the adsorbed surfactant should be close or slightly above its CMC. The second element is that the molecular structure of the surfactant should facilitate the formation of closely packed bilayers.
Alcohols Effect on Critic Micelle Concentration of Polysorbate 20 and Cetyl Trimethyl Ammonium Bromine Mixed Solutions
Authors: Sidim Taliha , Acar Gökhan
Published: January 2013

In this research, the micellar behavior of a cationic surfactant, cetyl trimethyl ammonium bromide (CTAB) and an nonionic surfactant, polysorbate 20 (Polyoxyethylene (20) sorbitan monolaurate) in different alcohol solutions media was investigated over the temperature range 293.15–313.15 K. The interaction between two surfactants in binary systems can be determined by calculating the values of their β parameters. The critical micelle concentrations (CMC) of the micelles were determined from the surface tension, the conductivity at different temperatures. The CMC behavior of CTAB and polysorbate 20 was analyzed in terms of the effect of temperature and the increase in the alcohol carbon chain. Changes in the critical micelle concentration of mixed surfactant systems of different alcohol solutions were measured. The CMC decreased sharply as the hydrocarbon chain length of the alcohols becomes larger. This shows that the more hydrophobic alcohols are, the more marked a decrease in CMC is observed.
Homeopathic treatment of premenstrual syndrome: a case series
Authors: Colas Aurélie , Terzan Laurence , Bordet Marie-France , Danno Karine
Published: January 2013

Objective: Observational, prospective study to describe the homeopathic management of premenstrual syndrome (PMS) by a group of French physicians.

Method: Women with PMS for >3 months were prescribed individualized homeopathic treatment. The intensity of 10 clinical symptoms of PMS was scored individually at inclusion and at a 3–6 month follow-up visit: absent = 0, mild = 1, moderate = 2, severe = 3. Total symptom score (range: 0–30) was calculated and compared for each patient at inclusion and at follow-up. PMS impact on daily activities (quality of life, QoL) was compared at inclusion and follow-up as: none, mild, moderate, severe, very severe.

Results: Twenty-three women were prescribed homeopathic treatment only (mean age: 39.7 years). Folliculinum (87%) was the most frequently prescribed homeopathic medicine followed by Lachesis mutus (52.2%). The most common PMS symptoms (moderate or severe) at inclusion were: irritability, aggression and tension (87%), mastodynia (78.2%) and weight gain and abdominal bloating (73.9%); and the most common symptoms at follow-up were: irritability, aggression and tension (39.1%), weight gain and abdominal bloating (26.1%) and mastodynia (17.4%). Mean global score for symptom intensity was 13.7 at inclusion and 6.3 at follow-up. The mean decrease in score (7.4) was statistically significant (p < 0.0001). Twenty-one women reported that their QoL also improved significantly (91.3%; p < 0.0001).

Conclusions: Homeopathic treatment was well tolerated and seemed to have a positive impact on PMS symptoms. Folliculinum was the most frequent homeopathic medicine prescribed. There appears to be scope for a properly designed, randomized, placebo-controlled trial to investigate the efficacy of individual homeopathic medicines in PMS.
Development of a food compositional database for the estimation of dietary intake of phyto-oestrogens in a group of postmenopausal women previously treated for breast cancer and validation with urinary excretion
Authors: Clarke Don B. , Lloyd Antony S. , Lawrence Judy M. , Brown Jonathan E. , Storey Lesley , Raats Monique , Rainsbury Richard M. , Culliford D. J. , Bailey-Horne Victoria A. , Parry Barbara M.
Published: January 2013

The scientific literature contains evidence suggesting that women who have been treated for breast cancer may, as a result of their diagnosis, increase their phyto-oestrogen (PE) intake. In the present paper, we describe the creation of a dietary analysis database (based on Dietplan6) for the determination of dietary intakes of specific PE (daidzein, genistein, glycitein, formononetin, biochanin A, coumestrol, matairesinol and secoisolariciresinol), in a group of women previously diagnosed and treated for postmenopausal breast cancer. The design of the database, data evaluation criteria, literature data entry for 551 foods and primary analysis by LC–MS/MS of an additional thirty-four foods for which there were no published data are described. The dietary intake of 316 women previously treated for postmenopausal breast cancer informed the identification of potential food and beverage sources of PE and the bespoke dietary analysis database was created to, ultimately, quantify their PE intake. In order that PE exposure could be comprehensively described, fifty-four of the 316 subjects completed a 24 h urine collection, and their urinary excretion results allowed for the description of exposure to include those identified as ‘equol producers’.
Acting with One Voice: Producing Unanimism in Algerian Reformist Theater
Authors: Goodman Jane E.
Published: January 2013

Scholars of democracy from Tocqueville to Habermas have long considered the proliferation of so-called voluntary associations as a sign of a flourishing civil society and as central to the rise of democratic modernity. I contend that the Algerian theatrical and musical associations of the reformist period anticipate another kind of civic history: a history of displays of unanimism in public life. I am interested in how and why Algerians learned to produce public displays of agreement for particular audiences (including themselves) at particular historical moments. I emphasize three factors that contributed to the production of unanimity: the achievement oftawḥīdor unity in the Islamic reform movement, vernacular practices of consensus-based argumentation, and French colonial legal and surveillance mechanisms. The essay engages theories of civil society, colonialism, and performance. It draws primarily on material from the French colonial archives for the city of Constantine, Algeria.
“History is stubborn”: Talk about Truth, Justice, and National Reconciliation in the Republic of Guinea
Authors: Arieff Alexis , McGovern Mike
Published: January 2013

This article uses an analysis of discussions of the November 1970 Portuguese attack on Guinea as a window into issues that continue to be raised concerning the country's first post-independence regime (1958–1984). We analyze ongoing debates among Guineans regarding the legacy of the former president, Sékou Touré, and whether or not there is a need for truth-telling and/or justice for abuses committed under his rule. One strand of this discussion focuses on legitimate political tactics and another on the politics of ethnicity in contemporary Guinea. The frequent assertion by Guinean interlocutors that “history is stubborn” points to both the perceived power of truth-telling and the ethno-political stakes with which these debates have become imbued. Debates among Guineans often focus on the uses and abuses of “truth and reconciliation” testimony, which for some Guineans is essential to breaking past cycles of violent state repression and for others is a kind of Pandora's box that could fuel not reconciliation but retribution. We show that Guineans are also engaged in a third order of analysis, of the status of “imported” notions of justice, agency, and culpability in an African setting.
An Irenic Idea about Metaphor
Authors: Lycan William G.
Published: January 2013

Donald Davidson notoriously rejected ‘metaphorical meaning’ and denied the existence of linguistic mechanisms by which metaphorical significance is conveyed. He contended that the meanings metaphorical sentences have are just their literal meanings, though metaphorical utterances may brute-causally have important cognitive effects. Contrastingly, John Searle offers a Gricean account of metaphor as an elaborated kind of implicature, and defends metaphorical meaning as speaker-meaning. Each of those positions is subject to very telling objections from the other's point of view. This paper proposes a synthesis that combines the respective virtues of Davidson's and Searle's accounts and avoids all the objections to each.
Communicating in 140 Characters or Less: Congressional Adoption of Twitter in the 111th Congress
Authors: Straus Jacob R. , Glassman Matthew Eric , Shogan Colleen J. , Smelcer Susan Navarro
Published: January 2013

Recently, new electronic technologies have supplemented older mechanisms of communication between members of Congress and their constituents. These technologies have enhanced members' options for communication, both with constituents and other interested parties. This research examines member use of one specific electronic communication medium: Twitter. Using original data to examine patterns of use, two models predict the probability of a member adopting Twitter based on political, personal, and district-level variables.
Between the Covers: International Relations in Books
Authors: Sharman J. C. , Weaver Catherine E.
Published: January 2013

Efforts to systematize our knowledge of international relations (IR) have tended to focus on journal articles while ignoring books. In contrast, we argue that to know IR we must know IR books. To this end, this article presents the first systematic analysis of such books based on coding 500 IR texts published by leading presses against variables covering methodology, theoretical paradigm, and policy application. We compare the results with those of the Teaching, Research, and International Policy (TRIP) project's coding of 2,800 journal articles against the same variables, and the 2008 and 2011 TRIP surveys of more than 3,000 IR scholars. The main findings are that books are much less quantitative than articles published in leading journals, are somewhat more representative of the field according to paradigm, and are more engaged with policy concerns.
The Desperation Argument for Geoengineering
Authors: Gardiner Stephen M.
Published: January 2013

Geoengineering has been roughly defined as “the intentional manipulation of planetary systems at a global scale” (Keith 2000; Schelling 1996). This definition is neither as precise nor as informative as some would like. Nevertheless, we can fix ideas by focusing on the most prominent current proposal, which is to inject sulfate aerosols into the stratosphere to deflect incoming radiation and so cool the Earth's surface. This is a paradigm case: if anything counts as geoengineering, stratospheric sulfate injection (hereafter SSI) does.
Situating and Abandoning Geoengineering: A Typology of Five Responses to Dangerous Climate Change
Authors: Heyward Clare
Published: January 2013

Geoengineering, the “deliberate, large-scale manipulation of the planetary environment in order to counteract anthropogenic climate change” (Shepherd et al. 2009, 1), is attracting increasing interest. As well as the Royal Society, various scientific and government organizations have produced reports on the potential and challenge of geoengineering as a potential strategy, alongside mitigation and adaptation, to avoid the vast human and environmental costs that climate change is thought to bring (Blackstock et al. 2009; GAO 2010; Long et al. 2011; Rickels et al. 2011). “Geoengineering” covers a diverse range of proposals conventionally divided into carbon dioxide removal (CDR) proposals and solar radiation management (SRM) proposals. This article argues that “geoengineering” should not be regarded as a third category of response to climate change, but should be disaggregated. Technically, CDR and SRM are quite different and discussing them together under the rubric of geoengineering can give the impression that all the technologies in the two categories of response always raise similar challenges and political issues when this is not necessarily the case. However, CDR and SRM should not be completely subsumed into the preexisting categories of mitigation and adaptation. Instead, they can be regarded as two parts of a five-part continuum of responses to climate change. To make this case, the first section of this article discusses whether geoengineering is distinctive, and the second situates CDR and SRM in relation to other responses to climate change.
PRIMARY MODEL GETS IT RIGHT AND EARLY
Authors: Norpoth Helmut , Bednarczuk Michael
Published: January 2013

In January of 2012, the Primary Model predicted that Barack Obama would defeat Mitt Romney by a comfortable margin. He did. Obama's popular vote total topped Romney's by more than four million votes. The Primary Model's forecast was by far the earliest of those assembled in the special 2012PSsymposium (45 (4): 614–617). Even so it predicted an Obama victory with greater certainty (almost 90%) than any other one. To put this performance in perspective, note that several models got it wrong in 2012, and hardly any of the other ones picking Obama to win did so with much certainty. Many preelection polls also failed to predict an Obama victory with their final estimate, including the venerable Gallup Poll. How did the Primary Model get it right so far in advance of Election Day 2012?
THE BREAD AND PEACE MODEL: 2012 PRESIDENTIAL ELECTION POSTMORTEM
Authors: Hibbs Douglas A.
Published: January 2013

President Obama received approximately 51.5% of the two-party vote in the 2012 election. The last Bread and Peace Model forecast of Obama's vote share, based on advance estimates of 2012:quarter 3 personal income posted on October 26, 2012, by the Bureau of Economic Analysis (BEA), was 46.6%—lower than the 47.5% forecast appearing in the October issue ofPS, which was based on July 27, 2012, BEA data. The Bread and Peace Model therefore underpredicted Obama's vote by 4 to 5 percentage points, equivalent to around 2 model standard errors. The president's vote therefore benefited from a +2-sigma composite shock to Bread and Peace Model fundamentals. Figure 1 shows actual and predicted values for 2012 in perspective of incumbent vote shares at all presidential elections 1952–2012.
FISCAL MODEL FAILURE: A MEASUREMENT PROBLEM? A PRELIMINARY ASSESSMENT
Authors: Cuzán Alfred G.
Published: January 2013

The Fiscal Model of presidential elections not only failed to predict that President Obama would win reelection handily, but the error incurred in the forecast of the incumbent share of the two-party vote was such (46.9%vs. 51.8% or more) as to warrant a rating of “inaccurate” or “quite inaccurate” in Campbell's table of benchmarks for evaluating forecasts (Campbell 2012, 611). This recap is a preliminary assessment of what went wrong.
2012 PRESIDENTIAL, US HOUSE, AND US SENATE FORECASTS
Authors: Klarner Carl E.
Published: January 2013

For the second presidential election in a row the prediction of the “Klarner Model” was within half a percent of the actual result. This model forecast that Obama would receive 51.3% of the two-party vote, while he actually received 51.8%. The model also called all states correctly, with the exception of Florida, which was predicted to be narrowly lost by Obama with 49.7% of the vote. These forecasts were made on July 15, 2012. This success does not indicate the model is better than the other models in the symposium as luck is a major determinant of which model gets closest to the mark. Although the Klarner Model correctly called 49 out of 50 states, that means little in an election where merely calling states on the basis of 2008 results would have called all but two correctly.
Power and Persuasion
Authors: West Lauren
Published: January 2013

109th APSA Annual Meeting, Chicago, August 29–Sept. 1, 2013

The APSA returns to Chicago, Illinois, and its roots, for the 2013 APSA Annual Meeting and Exhibition. In 1904, the association held its first Annual Meeting at Northwestern University and the University of Chicago. Home to these and other top colleges and universities, Chicago is again a fitting host for this leading intellectual gathering of political scientists.
Chin Up; Chest Out; Don't Panic
Authors: Laver Michael
Published: January 2013

Chin up; chest out; don't panic, yet. Yes, we who work in universities do face epic challenges described eloquently by King and Sen. Yes, we have indeed mostly ignored these—or rather have tended to wring our hands and wail operatically before planting our heads deeply in the sand. We will certainly experience massive technological disruptions of our traditional modus operandi and have only dim notions about how to respond to these. And all of us, if we are brutally honest, are deeply complicit in contributing to an unsustainably rising cost curve that, unchecked, will blow apart the very system that currently sustains our comfortable lives. These sorry truths are self-evident.