bluuebunny/crossref_metadata_2025 huggingface dataset:
Interfacial Dynamics and Solar Fuel Formation in Dye‐Sensitized Photoelectrosynthesis Cells
Authors: Song Wenjing , Chen Zuofeng , Glasson Christopher R. K. , Hanson Kenneth , Luo Hanlin , Norris Michael R. , Ashford Dennis L. , Concepcion Javier J. , Brennaman M. Kyle , Meyer Thomas J.
Published: June 2012

Dye‐sensitized photoelectrosynthesis cells (DSPECs) represent a promising approach to solar fuels with solar‐energy storage in chemical bonds. The targets are water splitting and carbon dioxide reduction by water to CO, other oxygenates, or hydrocarbons. DSPECs are based on dye‐sensitized solar cells (DSSCs) but with photoexcitation driving physically separated solar fuel half reactions. A systematic basis for DSPECs is available based on a modular approach with light absorption/excited‐state electron injection, and catalyst activation assembled in integrated structures. Progress has been made on catalysts for water oxidation and CO2 reduction, dynamics of electron injection, back electron transfer, and photostability under conditions appropriate for water splitting. With added reductive scavengers, as surrogates for water oxidation, DSPECs have been investigated for hydrogen generation based on transient absorption and photocurrent measurements. Detailed insights are emerging which define kinetic and thermodynamic requirements for the individual processes underlying DSPEC performance.
Computational Strategies for Spectroscopy: From Small Molecules to Nano Systems. Edited by V. Barone
Authors: Jacob Christoph R.
Published: June 2012

Wiley, 2011, 608 pp., $125.00
Human amygdala development in the absence of species‐expected caregiving
Authors: Tottenham Nim
Published: June 2012

In altricial species, like the human, caregiver presence is necessary for typical emotional development. Children who have been raised in institutional care early in life experience caregiver deprivation and are at significantly elevated risk for emotional difficulties. The current manuscript examines the non‐human and human literatures on amygdala development following caregiver deprivation and presents an argument that in the absence of the species‐expected caregiver presence, human amygdala development exhibits rapid development and perhaps premature engagement that results in some of the emotional phenotypes observed following early institutional care. © 2012 Wiley Periodicals,Inc. Dev Psychobiol 54: 598–611, 2012.
Sensorless sinusoidal wave drive for control of power factor of PM motor by detection of inverter bus current
Authors: Matsushita Motoshi , Kameyama Hiroyuki , Ikeboh Yasuhiro , Morimoto Shigeo
Published: June 2012

Permanent‐magnet synchronous motors (PMSMs) with sinusoidal back EMF are widely used in domestic appliances for the reduction of acoustic noise and energy consumption. PMSMs are generally controlled with a sinusoidal waveform current. Typically, PMSMs are controlled by vector‐controlled sinusoidal drives, which require substantial computational resources. Hence, simpler sinusoidal wave drives such as V/f drives, which control the phase difference between the voltage and the current (the power factor of the PM motor), have been proposed for controlling PMSMs, This paper presents a new method that does not require current sensors but can be used to estimate the phase difference by sampling the voltage of the shunt resistor, which is used to detect the overcurrent supplied to the inverter. This method allows for detection of the current and accurate estimation and appropriate control of the phase difference. Using this method, we were able to control the phase difference and achieve high efficiency, cost reduction, and high reliability. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(4): 57–65, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21201
Dependence of internal pressure rise due to arc on current waveform and ignition position
Authors: Tanaka Shin‐Ichi , Miyagi Tsukasa , Iwata Mikimasa , Amakawa Tadashi
Published: June 2012

This paper describes an experimental study concerning the pressure rise due to high current arcs in a closed chamber. In this study, the arcs were ignited in certain chambers of varying size under the same conditions, namely, an arc current of 12.5 kA and an arc duration of 0.1 s. Moreover, the pressure rises in the chambers were measured while varying the current waveform, namely, the frequency of the AC power source and the DC component of the current, and the ignition position. Based on each measured waveform, not only the maximum value $\Delta {P_{{\rm{max}}}}$ but also the middle value $\Delta {P_{{\rm{mid}}}}$, which was the midpoint of the amplitude around the time point of $\Delta {P_{{\rm{max}}}}$, were extracted. As a result of the evaluation using both $\Delta {P_{{\rm{max}}}}$ and $\Delta {P_{{\rm{mid}}}}$, it was shown that $\Delta {P_{{\rm{max}}}}/\Delta {P_{{\rm{mid}}}}$ varied with both the current waveform and the ignition position, whereas $\Delta {P_{{\rm{mid}}}}$ was independent of them. Through FFT analysis of both the pressure rise and the arc power waveforms, it was verified that this experimental result was related to the resonance effect between the pressure rise and the arc power oscillations. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(4): 18–28, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22271
Osteopontin promotes inflammation in patients with acute coronary syndrome through its activity on IL‐17 producing cells
Authors: Zheng Yingxia , Wang Zhihao , Deng Lin , Yuan Xiangliang , Ma Yanhui , Zhang Guanghui , Gantier Michael P. , Liu Jun‐Ping , Shen Lisong , Xu Dakang
Published: June 2012

Atherosclerosis is a progressive disease with a strong inflammatory component. Here we confirm the existence of a critical imbalance in the ratio of Th17 to Treg‐cell populations in peripheral CD4+ T cells from patients with acute coronary syndrome (ACS), which favors inflammation. This was concurrent with increased IL‐17 production from the CD4+CD45RA−FOXP3lo Treg‐cell subset, and elevated osteopontin (OPN) levels in serum from ACS patients. We demonstrate a direct effect of OPN in serum from ACS patients on increased IL‐17 production by CD4+CD45RA−FOXP3lo T cells, mediated through recruitment of the OPN receptors CD29 and CD44, and dependent on STAT3 and the nuclear hormone receptor retinoic‐acid‐related orphan receptor‐γt (RORγt) pathway, but not IL‐6 production. To our knowledge and beyond the disease context of ACS, this study constitutes the first demonstration of a critical role for OPN in the positive regulation of inflammation through increased IL‐17 production by CD4+CD45RA−FOXP3lo cells.
Insensitive Nitrogen‐Rich Energetic Compounds Based on the 5,5′‐Dinitro‐3,3′‐bi‐1,2,4‐triazol‐2‐ide Anion
Authors: Dippold Alexander A. , Klapötke Thomas M. , Winter Nils
Published: June 2012

In this contribution the improvements achieved in the synthesis of the thermally stable energetic heterocycle 5,5′‐dinitro‐2H,2′H‐3,3′‐bi‐1,2,4‐triazole (DNBT) are described. The main goal was the synthesis of at least equally stable but more powerful energetic compounds based on the DNBT2– anion in combination with nitrogen‐rich cations. A complete structural and spectroscopic characterization, including IR, Raman, and multinuclear NMR analyses of the uncharged compound is presented. In addition, X‐ray crystallographic measurements on DNBT revealed a very high density of 1.903 g cm–3. To increase both performance and stability, highly nitrogen‐rich salts of DNBT formed from ammonium, hydroxyammonium, hydrazinium, guanidinium, aminoguanidinium and triaminoguanidinium cations were prepared and fully characterized by vibrational and multinuclear NMR spectroscopy, DSC, and X‐ray diffraction measurements. The standard enthalpies of formation were calculated for selected compounds at the CBS‐4M level of theory and the detonation parameters were calculated by using the EXPLO5.5 program. In addition, the impact as well as friction sensitivities and sensitivity against electrostatic discharge were determined.
Planar rocking response and stability analysis of an array of free‐standing columns capped with a freely supported rigid beam
Authors: Makris Nicos , Vassiliou Michalis F.
Published: June 2012

This paper investigates the planar rocking response of an array of free‐standing columns capped with a freely supported rigid beam in an effort to explain the appreciable seismic stability of ancient free‐standing columns that support heavy epistyles together with the even heavier frieze atop. Following a variational formulation, the paper concludes to the remarkable result that the dynamic rocking response of an array of free‐standing columns capped with a rigid beam is identical to the rocking response of a single free‐standing column with the same slenderness yet with larger size, that is a more stable configuration. Most importantly, the study shows that the heavier the freely supported cap beam is (epistyles with frieze atop), the more stable is the rocking frame regardless of the rise of the center of gravity of the cap beam, concluding that top‐heavy rocking frames are more stable than when they are top light. This ‘counter intuitive’ finding renders rocking isolation a most attractive alternative for the seismic protection of bridges with tall piers, whereas its potential implementation shall remove several of the concerns associated with the seismic connections of prefabricated bridges. Copyright © 2012 John Wiley & Sons, Ltd.
Why dual enrollment?
Authors: Hofmann Eric
Published: June 2012

Providing an overview of the volume, this chapter summarizes the evolution of dual enrollment programs over the past decade and discusses the role dual enrollment can play in the nation's college‐completion agenda.
Does dual enrollment increase students’ success in college? Evidence from a quasi‐experimental analysis of dual enrollment in New York City
Authors: Allen Drew , Dadgar Mina
Published: June 2012

This chapter reviews previous studies on dual enrollment and discusses the results of an evaluation of College Now, the dual enrollment program of The City University of New York. The authors find that dual enrollment participation increases postsecondary achievement.
Using college placement exams as early signals of college readiness: An examination of California's Early Assessment Program and New York's At Home in College program
Authors: Venezia Andrea , Voloch Daniel
Published: June 2012

This chapter highlights policies and practices associated with two postsecondary preparation programs that use college placement exams and specially designed courses to create better alignment between secondary and postsecondary institutions.
Seeding of the percutaneous endoscopic gastrostomy site from head and neck carcinoma: Case report and review of the literature
Authors: Sinapi I. , Navez B. , Hamoir M. , Schmitz S. , Machiels J. P. , Deprez P. H. , Van den Eynde M.
Published: June 2012

Background

Percutaneous endoscopic gastrostomy (PEG) is a relatively safe procedure and is an important supportive treatment for patients with advanced head and neck cancer. Although tumor seeding has been reported in various sites, seeding at the PEG exit site is a rare complication.

Methods and Results

We describe a clinical case in which squamous cell carcinoma of the hypopharynx implanted at the site of PEG insertion and was successfully removed by surgery. PEG was previously placed by the “pull” technique. A review of the literature, discussion of the mechanism of spread, and recommendations to avoid this complication are discussed.

Conclusions

To avoid this rare and poor prognostic complication, the “pull” technique should be avoided for PEG placement in any patient with head and neck squamous cell carcinoma. An alternative method such as the “push” technique should be preferred. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Cross‐classified random effects models in institutional research
Authors: Meyers Laura E.
Published: June 2012

This chapter provides an example of how cross‐classified random effects modeling can be used in institutional research by examining faculty gender pay gaps overall and by principal activity.
Multilevel modeling: Presenting and publishing the results for internal and external constituents
Authors: Pike Gary R. , Rocconi Louis M.
Published: June 2012

Multilevel modeling provides several advantages over traditional ordinary least squares regression analysis; however, reporting results to stakeholders can be challenging. This chapter identifies some useful principles for reporting results.
Targeted therapy: The new lease on life for acute promyelocytic leukemia, and beyond
Authors: Chen Sai‐Juan , Zhou Guang‐Biao
Published: June 2012

Leukemia, a group of hematological malignancies characterized by abnormal proliferation, decreased apoptosis, and blocked differentiation of hematopoietic stem/progenitor cells, is a disease involving dynamic change in the genome. Chromosomal translocation and point mutation are the major mechanisms in leukemia, which lead to production of oncogenes with dominant gain of function and tumor suppressor genes with recessive loss of function. Targeted therapy refers to treatment strategies perturbing the molecules critical for leukemia pathogenesis. The t(15;17) which generates PML‐RARα, t(8;21) that produces AML1‐ETO, and t(9;22) which generates BCR‐ABL are the three most frequently seen chromosomal translocations in myeloid leukemia. The past two to three decades have witnessed tremendous success in development of targeted therapies for acute and chronic myeloid leukemia caused by the three fusion proteins. Here, we review the therapeutic efficacies and the mechanisms of action of targeted therapies for myeloid leukemia and show how this strategy significantly improve the clinical outcome of patients and even turn acute promyelocytic leukemia from highly fatal to highly curable. © 2012 IUBMB IUBMB Life, 64(8): 671–675, 2012
DO INTERNATIONAL NON‐GOVERNMENTAL ORGANIZATIONS WALK THE TALK? RECONCILING THE ‘TWO PARTICIPATIONS’ IN INTERNATIONAL DEVELOPMENT
Authors: Brunt Carol , McCourt Willy
Published: June 2012

International non‐governmental organizations (INGOs) espouse principles of participation and empowerment, for the most part applied to INGOs' beneficiaries rather than their staff. Evidence from a study of seven INGOs operating in Kenya indicates that beneficiaries participate much less, and staff somewhat more, than INGO rhetoric would suggest. Although participation of both groups was limited, beneficiary involvement was episodic at best, whereas staff had continuous, albeit constrained access to regular meetings and other fora. The need to be accountable to donors was a major limiting factor. However, all stakeholders, including donors, share an interest in achieving long‐term results, and the evidence from the literature and our own empirical findings is that participation facilitates achieving those results. Thus, our study suggests that the ‘two participations’ can be reconciled through a focus on the long‐term interests of INGOs' intended beneficiaries. Copyright © 2012 John Wiley & Sons, Ltd.
The Effects of Coding Bias on Estimates of Behavioural Similarity in Crime Linking Research of Homicides
Authors: Pakkanen Tom , Zappalà Angelo , Grönroos Caroline , Santtila Pekka
Published: June 2012

This study explored whether a coding bias due to knowledge of which crimes have been committed by the same offender exists when behavioural variables are coded in serial murder cases. The study used an experimental approach where the information given to the participants (N = 60) concerning correct linkages between a number of murder series was manipulated. The participants were divided into three different groups (n = 20 in each). These three groups received correct, incorrect, or no information about the linked series prior to the coding. The results showed that there is no clear evidence to support the hypothesis of a bias in the coding. The risk of expectancy effects and suggestions on how to minimise them in behavioural crime linking research were discussed, and suggestions on how to improve the validity of possible future replications of the experiment were given. The practical implications of expectancy effects on behavioural crime linking decisions for the justice system were also discussed. Copyright © 2012 John Wiley & Sons, Ltd.
The prevalence of different HPV types in Turkish women with a normal Pap smear
Authors: Demir Esra Tamburaci , Ceyhan Mehmet , Simsek Mehmet , Gunduz Tonguc , Arlier Sefa , Aytac Rusen , Aycan Ahmet Emre , Gurbuz Venhar
Published: June 2012

The age‐specific human papillomavirus (HPV) seroprevalence and HPV type distribution in women with normal cervical cytology were studied. Cervical smear samples obtained using liquid‐based smears from 582 clinically healthy women aged between 15 and 68 years from five centers from four different regions of Turkey, were studied between February 2010 and January 2011. Overall, 530 of the women with normal cytology were included and the samples were analyzed for the presence of HPV by AmpliTaq. Positive samples were typed further for 37 different HPV genotypes by a line blot assay. HPV was positive in 17.9% of the women. HPV prevalence was highest in the age group of 25–29 years (31.8%), and decreased with increasing age. HPV 16 was the most common type (3.6%) followed by type 6 (2.6%) and type 45 (2.2%). Types 11 and 18 were rare (0.6% and 0.4%, respectively). Among the risk factors, number of sexual partners and parity were positively correlated with HPV positivity. In the present study, a large number of sex partners and high parity increased the risk for HPV infection. The age‐specific distribution of HPV in women with normal Pap smears did not show a U‐shaped curve in contrast to European countries and the USA. J. Med. Virol. 84: 1242–1247, 2012. © 2012 Wiley Periodicals, Inc.
Prevalence, risk factors, and molecular epidemiology of hepatitis B and hepatitis delta virus in pregnant women and in patients in Mauritania
Authors: Mansour Wael , Malick F‐ Zahra Fall , Sidiya Ahmad , Ishagh Elkhalil , Chekaraou Mariama Abdou , Veillon Pascal , Ducancelle Alexandra , Brichler Ségolène , Le Gal Frédéric , Lo Baidy , Gordien Emmanuel , Lunel‐Fabiani Françoise
Published: June 2012

No recent data are available on hepatitis B virus (HBV) and hepatitis Delta virus (HDV) prevalence in Mauritania. One thousand twenty pregnant women and 946 patients visiting for routine checkups were screened for HBV and HDV infection. Demographic, epidemiological, ethnic, clinical, and biological data were recorded. HBV and HDV genotypes were determined by sequencing and phylogenetic analyses. In the pregnant women and patients cohorts, respectively, the prevalence of HBsAg (10.7% and 18.3%) and anti‐HBcAb (66.3% and 76.5%) indicated high HBV endemicity. In pregnant women, exposure to HBV was significantly associated in multivariate analysis with education level, ethnicity, blood transfusion, and occupation. HDV antibodies (HDVAb) were found in 14.7% of pregnant women. In patients, HBsAg was found less frequently in females than in males. Again in multivariate analysis, exposure to HBV was significantly correlated with gender (males), and HDVAb positivity with age and gender. The HBV DNA viral load was >3 log IU/ml in only 10.1% of pregnant women and in 17.3% of patients. HDV‐RNA was detectable in 21 (67.7%) of the 31 patients positive for HDVAb, and in 11 of the 16 pregnant women positive for HDVAb (68.8%). The most frequent HBV genotypes were: HBV/D, 53%; HBV/E, 35%; and HBV/A, 12%. Sub‐genotyping revealed HBV/D1,/D7, and the recently described/D8. HDV genotypes were: HDV‐1, 90.3% and HDV‐5, 9.7%. This study confirms the high prevalence of HBV and HDV infections in Mauritania and demonstrates the high genetic diversity of HBV in this country. J. Med. Virol. 84: 1186–1198, 2012. © 2012 Wiley Periodicals, Inc.
Biodegradation of plastified starch obtained by corotation twin‐screw extrusion
Authors: Bajer Krzysztof , Richert Agnieszka , Bajer Dagmara , Korol Jerzy
Published: June 2012

The potato starch has been subjected to plastification with glycerol using twin‐screw extruder in different conditions. The structure of obtained samples has been determined by Fourier transform infrared spectroscopy with attenuated total reflectance methods. The average molecular weights by chromatographic method and solubility in water have also been determined. Next, the susceptibility of all samples to activity of microorganisms such as bacteria, fungi, and actinomycetes has been checked. It has been stated that increasing rotation speed of extruder screws causes the degradation of starch slightly, influencing the later bio‐decomposition. The actinomycetes are the most effective in this process. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Modification of lignin and its application as char agent in intumescent flame‐retardant poly(lactic acid)
Authors: Zhang Rui , Xiao Xifu , Tai Qilong , Huang Hua , Hu Yuan
Published: June 2012

Urea‐modified lignin was prepared according to the Mannich reaction and well characterized by Fourier transform infrared spectrometer, elemental ananlyses, and scanning electron microscopy (SEM). Ammonium polyphosphate (APP) and urea‐modified lignin were added into poly(lactic acid) (PLA) as a novel intumescent flame‐retardant (IFR) system to improve flame retardancy of PLA. The flammability of IFR–PLA composites was studied using limiting oxygen index, UL‐94 vertical burning method and cone calorimeter test, and their thermal stability was evaluated by thermogravimetric analysis. The results showed that the urea‐modified lignin combined with APP exhibited much better flame retardancy and thermal stability than that of the combination of virgin lignin and APP. The improvement may be attributed to the better char morphology with more phosphoric char evidenced by SEM and X‐ray photoelectron spectroscopy. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
In situ fourier‐transform infrared spectra analysis of hydrogen bond in polypropylene/chlorinated polypropylene/polyaniline composite
Authors: Yang Lin , Zhang Zhiye , Wang Xinlong , Chen Jinyao , Li Huilin
Published: June 2012

The previous studies suggest that hydrogen bond between chlorinated polypropylene (CPP) and polyaniline (PANI) plays a prominent role in the decision of polypropylene/CPP/PANI composites' electric property. In situ Fourier‐transform infrared spectra were employed to detect and identify the relationship between the hydrogen bond and the temperature. Two kinds of hydrogen bond were carefully studied in the nitrogen–hydrogen bond (NH) stretching, sulfur–oxygen double bond (SO) stretching, and carbon–chlorine bond (CCl) stretching regions, using an iterative least‐squares computer program to obtain the best fit of spectra. The ratio of absorptivity coefficients and the mole fraction of the “free” and two kinds of H‐bonded NH were calculated. There exists an apparent turning point in the curves of the relationship between the fraction of two kinds of H‐bonded NH and temperature. This phenomenon also exists in the SO stretching region, and the turning point is at about 60°C. The mole fraction of H‐bonded CCl decreases, and that of “free” CCl increases with increasing temperature. The enthalpy gap between the H‐bonded NH…OS and the H‐bonded NH…ClC dissociation was also obtained as 23.2 KJ/mol. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Cellular polypropylene‐based piezoelectric films
Authors: Qaiss Abouelkacem , Saidi Hassan , Fassi‐Fehri Omar , Bousmina Mosto
Published: June 2012

Cellular polypropylene‐calcium carbonate based piezoelectric films were obtained using biaxial stretching and gas‐mediated inflation followed by a corona discharge treatment using home‐made devices. The obtained results revealed a cellular structure that develops at the interface between the solid particles and the polymer matrix and the final piezoelectric coefficient was found to depend both on the gas pressure profile and on time. The inflation step gives better results when the gas pressure is increased in stepwise manner allowing the gas to adequately intrude the cavities and maintain the required pressure. The overall results are discussed in terms of processing conditions and in terms of the developed microstructure. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Rheological behavior of cycloolefin copolymer/graphite composites
Authors: Kasgoz Alper , Akın Dinçer , Durmus Ali
Published: June 2012

In this study, morphological and rheological properties of cycloolefin copolymer (COC)/graphite composites prepared in a twin screw extruder by using various amounts of graphite (G) and expanded graphite (EG) were investigated in detail. Rheological behaviors of the samples were measured in a dynamic oscillatory rheometer in the melt state. Rheology data were analyzed in different ways in order to quantify the microstructural features which indicate the solid‐state physical properties of the composite materials. In the linear viscoelastic region, increasing of storage modulus (G′) with the filler amount and the van Gurp‐Palmen plots were used to determine the percolation threshold which is the critical filler amount for the physical network formation by the G sheets. Percolation threshold values were found to be about 21.5 phr and 3.8 phr for the G‐ and EG‐loaded samples, respectively. Microstructures of the samples which include quite higher amount of filler than the percolation were observed in a scanning electron microscopy. It was found that the sheets of pristine G maintained their original stack form while the EG was successfully dispersed in the COC phase and formed three dimensional house‐of‐card structures without a compatibilizer. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Experimental analyses of the poly(vinyl chloride) foams' mechanical anisotropic behavior
Authors: Tita Volnei , Caliri Mauricio Francisco , Angélico Ricardo Afonso , Canto Rodrigo Bresciani
Published: June 2012

Assessing a full set of mechanical properties is a rather complicate task in the case of foams, especially if material models must be calibrated with these results. Many issues, for example anisotropy and heterogeneity, influence the mechanical behavior. This article shows through experimental analyses how the microstructure affects different experimental setups and it also quantifies the degree of anisotropy of a poly(vinyl chloride) foam. Monotonic and cyclic experimental tests were carried out using standard compression specimens and non‐standard tensile specimens. Results are complemented and compared with the aid of a digital image correlation technique and scanning electron microscopy analyses. Mechanical properties (e.g., elastic and plastic Poisson's ratios) are evaluated for compression and tensile tests, for two different material directions (normal and in‐plane). The material is found to be transversely isotropic. Differences in the results of the mechanical properties can be as high as 100%, or even more depending on the technique used and the loading direction. Also, the experimental analyses show how the material's microstructure behavior, like the evolution of the herein identified “yield fronts” and a “spring back” phenomenon, can influence the phenomenological response and the failure mechanisms as well as the hardening curves. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Studying the Thermal Properties of a Cotton/Epoxy Composite Inhibitor
Authors: Shahedifar Vahideh , Tajik Hamid Reza , Rezadoust Amir Masoud
Published: June 2012

The inhibitory effect of double‐base solid propellants is used to control and prevent the burning degree of exposed areas, induced by longer burning time. In recent years, inhibition with cellulose derivatives including cellulose acetate and ethyl cellulose has become popular, but these monolithic systems usually suffer from the drawback of a high erosion rate and demand high thickness and low burning time. A composite inhibitor based on cotton fibers/epoxy resin containing some chlorinated flame retardants (CFR), which were added in inhibitor composition to control its burning process, is described in this article. The thermal properties of the composite inhibitor were studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), thermomechanical analysis (TMA), and flame retardancy. Finally, the inhibited propellant charge, statically fired at ambient temperature, was found to display a smooth and flat pressure‐time profile, confirming the successful performance of the composite inhibition system without the application of any barrier coat.
Quantifying LOPA uncertainty
Authors: Freeman Raymond “Randy”
Published: June 2012

Layer of protection analysis (LOPA) is a semi‐quantitative risk evaluation tool. The methodology is widely used in setting safety integrity level (SIL) targets for safety instrumented systems (SIS). The methodology is often used to evaluate the adequacy of existing protective systems against corporate risk targets. The LOPA method is based on the use of conservative but representative estimates of the failure probability of protective systems. The results of these studies are presented to management for concurrence with the conclusions and for funding of recommendations. Management sometimes asks questions such as:

What is the uncertainty in the results?

How sensitive are the results to the underlying data and assumptions?

How conservative is the LOPA methodology? Should additional independent protection layers be recommended from the LOPA study to compensate for uncertainty in the results?

There is no existing method for the analysis of uncertainty in a LOPA study. This article presents a framework to answer management questions related to the LOPA uncertainty. Guidance is presented on methods to incorporate an uncertainty analysis into a LOPA or quantitative risk analysis study. © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012
A Study of Nonlinear Effects in a Cushion‐Product System on its Vibration Transmissibility Estimates with the Reverse Multiple Input–Single Output Technique
Authors: A. Sek Michael , Rouillard Vincent , Parker Anthony J.
Published: June 2012

The Reverse Multiple Input–Single Output (R‐MISO) identification technique was implemented to determine vibration transmissibility frequency response functions (FRFs) of a cushion‐product system that accounts for nonlinearities known to exist in such systems. The signed quadratic x|x| nonlinear term was used. The results were compared with the classical linear approximation FRFs calculated with the single input–single output identification method. Comparisons were made for five types of expanded polystyrene (EPS) cushions with varying density and two levels of band‐limited random excitation. It was shown that vibration transmissibility FRFs obtained with the R‐MISO method and with the inclusion of a signed quadratic x|x| nonlinear term significantly (up to ~70%) improved the total coherence of the nonlinear vibration transmissibility FRFs for the EPS cushions subjected to the static load selected to coincide with the optimum of their respective cushion curves. The R‐MISO technique was successful in accounting for some of the nonlinearities in the EPS cushion‐product system. However, its ability to deal with nonlinearities is not specific to the EPS but rather common to cushion‐product systems subjected to vertical vibrations. Copyright © 2012 John Wiley & Sons, Ltd.
Beryllium cluster cages endohedrally doped by hydrogen: H2@Ben (8 ≤ n ≤ 14)
Authors: Naumkin Fedor Y. , Wales David J.
Published: June 2012

Core‐shell structures of hydrogen‐beryllium clusters are predicted to be higher energy isomers relative to the separate H2 and Ben components, the hydrogen molecule dissociating inside the beryllium cage due to strong charge transfer. Variations of the system shape and stability with the relative orientation of the molecular core inside the metal shell and with its size are analyzed. Pathways and energy barriers for extraction of H2 and for its dissociative attachment to Ben from outside are evaluated. The effect of such endohedral doping on the electronic properties, including dipole moment, electronic excitation, ionization and electron attachment are also examined. © 2012 Wiley Periodicals, Inc.
Molecular determinants for ligand binding at serotonin 5‐HT2A and 5‐HT2C GPCRs: Experimental affinity results analyzed by molecular modeling and ligand docking studies
Authors: Córdova‐Sintjago Tania , Sakhuja Rajeev , Kondabolu Krishnakanth , Canal Clinton E. , Booth Raymond G.
Published: June 2012

Ligands that activate the serotonin 5‐HT2C G protein‐coupled receptor (GPCR) may be therapeutic for psychoses, addiction, and other neuropsychiatric disorders. Ligands that are antagonists at the closely related 5‐HT2A GPCR also may treat neuropsychiatric disorders; in contrast, 5‐HT2A activation may cause hallucinations. 5‐HT2C‐specific agonist drug design is challenging because 5‐HT2 GPCRs share 80% transmembrane (TM) homology, same second messenger signaling, and no crystal structures are reported. To help delineate molecular determinants underlying differential binding and activation of 5‐HT2 GPCRs, 5‐HT2A, and 5‐HT2C homology models were built from the β2‐adrenergic GPCR crystal structure and equilibrated in a lipid phosphatidyl choline bilayer performing molecular dynamics simulations. Ligand docking studies at the 5‐HT2 receptor models were conducted with the (2R, 4S)‐ and (2S, 4R)‐enantiomers of the novel 5‐HT2C agonist/5‐HT2A/2B antagonist trans‐4‐phenyl‐N,N‐dimethyl‐2‐aminotetralin (PAT) and its 4′‐chlorophenyl congners. Results indicate PAT–5‐HT2 molecular interactions especially in TM domain V are important for the (2R, 4S) enantiomer, whereas, TM domain VI and VII interactions are more important for the (2S, 4R) enantiomer. © 2012 Wiley Periodicals, Inc.
Peak shape analysis of Ag 3d core‐level X‐ray photoelectron spectra of Au@Ag core‐shell nanoparticles using an asymmetric Gaussian–Lorentzian mixed function
Authors: Maenosono Shinya , Lee JaeDong , Dao Anh Thi Ngoc , Mott Derrick
Published: June 2012

This article reports on the peak shape analysis of X‐ray photoelectron spectra of gold‐silver core‐shell (Au@Ag) nanoparticles (NPs) using an asymmetric Gaussian–Lorentzian mixed function. Unlike Ag NPs, Au@Ag NPs have no oxide peak and show asymmetric line shape with a high energy tail in Ag 3d core‐level spectra. A monotonic increase in the Ag 3d binding energy and a decrease in the degree of asymmetry with increasing the Ag shell thickness were observed supporting the occurrence of charge transfer from Au core to Ag shell. Copyright © 2012 John Wiley & Sons, Ltd.
Estimation of mediation effects for zero‐inflated regression models
Authors: Wang Wei , Albert Jeffrey M.
Published: June 2012

The goal of mediation analysis is to identify and explicate the mechanism that underlies a relationship between a risk factor and an outcome via an intermediate variable (mediator). In this paper, we consider the estimation of mediation effects in zero‐inflated (ZI) models intended to accommodate ‘extra’ zeros in count data. Focusing on the ZI negative binomial models, we provide a mediation formula approach to estimate the (overall) mediation effect in the standard two‐stage mediation framework under a key sequential ignorability assumption. We also consider a novel decomposition of the overall mediation effect for the ZI context using a three‐stage mediation model. Estimation of the components of the overall mediation effect requires an assumption involving the joint distribution of two counterfactuals. Simulation study results demonstrate low bias of mediation effect estimators and close‐to‐nominal coverage probability of confidence intervals. We also modify the mediation formula method by replacing ‘exact’ integration with a Monte Carlo integration method. The method is applied to a cohort study of dental caries in very low birth weight adolescents. For overall mediation effect estimation, sensitivity analysis was conducted to quantify the degree to which key assumption must be violated to reverse the original conclusion. Copyright © 2012 John Wiley & Sons, Ltd.
Different ranking approaches defining association and agreement measures of paired ordinal data
Authors: Svensson Elisabeth
Published: June 2012

Rating scales are common for self‐assessments of qualitative variables and also for expert‐rating of the severity of disability, outcomes, etc. Scale assessments and other ordered classifications generate ordinal data having rank‐invariant properties only. Hence, statistical methods are often based on ranks. The aim is to focus at the differences in ranking approaches between measures of association and of disagreement in paired ordinal data. The Spearman correlation coefficient is a measure of association between two variables, when each data set is transformed to ranks. The augmented ranking approach to evaluate disagreement takes account of the information given by the pairs of data, and provides identification and measures of systematic disagreement, when present, separately from measures of additional individual variability in assessments. The two approaches were applied to empirical data regarding relationship between perceived pain and physical health and reliability in pain assessments made by patients. The art of disagreement between the patients' perceived levels of outcome after treatment and the doctor's criterion‐based scoring was also evaluated. The comprehensive evaluation of observed disagreement in terms of systematic and individual disagreement provides valuable interpretable information of their sources. The presence of systematic disagreement can be adjusted for and/or understood. Large individual variability could be a sign of poor quality of a scale or heterogeneity among raters. It was also demonstrated that a measure of association must not be used as a measure of agreement, even though such misuse of correlation coefficients is common. Copyright © 2012 John Wiley & Sons, Ltd.
Validating pragmatic reuse tasks by leveraging existing test suites
Authors: Makady Soha , Walker Robert J.
Published: June 2012

Traditional industrial practice often involves the ad hoc reuse of source code that was not designed for that reuse. Such pragmatic reuse tasks play an important role in disciplined software development. Pragmatic reuse has been seen as problematic due to a lack of systematic support, and an inability to validate that the reused code continues to operate correctly within the target system. Although recent work has successfully systematized support for pragmatic reuse tasks, the issue of validation remains unaddressed. In this paper, we present a novel approach and tool to semi‐automatically reuse and transform relevant portions of the test suite associated with pragmatically reused code, as a means to validate that the relevant constraints from the originating system continue to hold, while minimizing the burden on the developer. We conduct a formal experiment with experienced developers, to compare the application of our approach versus the use of a standard IDE (the ‘manual approach’). We find that, relative to the manual approach, our approach: reduces task completion time; improves instruction coverage by the reused test cases; and improves the correctness of the reused test cases. Copyright © 2012 John Wiley & Sons, Ltd.
Using self‐generated analogies in teaching of thermodynamics
Authors: Haglund Jesper , Jeppsson Fredrik
Published: June 2012

Using self‐generated analogies has been proposed as a method in a constructivist tradition for students to learn about a new subject, by use of what they previously know. We report on a group exercise on using self‐generated analogies to make sense of two thermodynamic processes, reversible adiabatic expansion and free adiabatic expansion of an ideal gas. The participants (N = 8) were physics preservice teacher students at the fourth year of the teacher education program. A main finding was that work with self‐generated analogies tended to be accompanied by the students assuming ownership for their learning, manifested in terms of actions of choice and control and the use of exploratory talk. Consequently, several self‐generated analogies were elaborated and developed to a high‐order relational structure. However, we also found that with the use of self‐generated analogies in science teaching follows the risks of developing idiosyncratic explanations of the encountered phenomena or getting stuck in overly complex comparisons.

Sammanfattning: Självgenererade analogier har förts fram som en metod i en konstruktivistisk tradition för att elever och studenter ska kunna lära sig något nytt genom att relatera till vad de redan vet. Vi redogör här för en gruppövning där självgenererade analogier användes för att förstå två termodynamiska processer: reversibel adiabatisk expansion, respektive fri adiabatisk expansion av en ideal gas. Åtta (N = 8) lärarstudenter på fjärde året av utbildningen med inriktning mot fysik på gymnasiet deltog i studien. Ett viktigt resultat var att vid arbete med självgenererade analogier tenderade studenterna att ta ägandeskap för sitt lärande, vilket tog sig uttryck i handlingar såsom aktiva val, kontroll över processen och explorativ dialog. Som en följd utvecklades flera av de självgenererade analogierna till ett stort strukturellt djup. Samtidigt såg vi att vid skapande av egna analogier löper studenter risken att utveckla egna förklaringar av de studerade fenomenen som inte svarar mot dem inom vetenskapen eller snärja in sig i alltför komplexa jämförelser. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 898–921, 2012
Mechanisms and implications of programmed translational frameshifting
Authors: Dinman Jonathan D.
Published: June 2012

While ribosomes must maintain translational reading frame in order to translate primary genetic information into polypeptides, cis‐acting signals located in mRNAs represent higher order information content that can be used to fine‐tune gene expression. Classes of signals have been identified that direct a fraction of elongating ribosomes to shift reading frame by one base in the 5′ (−1) or 3′ (+1) direction. This is called programmed ribosomal frameshifting (PRF). Although mechanisms of PRF differ, a common feature is induction of ribosome pausing, which alters kinetic partitioning rates between in‐frame and out‐of‐frame codons at specific ‘slippery’ sequences. Many viruses use PRF to ensure synthesis of the correct ratios of virus‐encoded proteins required for proper viral particle assembly and maturation, thus identifying PRF as an attractive target for antiviral therapeutics. In contrast, recent studies indicate that PRF signals may primarily function as mRNA destabilizing elements in cellular mRNAs. These studies suggest that PRF may be used to fine‐tune gene expression through mRNA decay pathways. The possible regulation of PRF by noncoding RNAs is also discussed. WIREs RNA 2012 doi: 10.1002/wrna.1126

This article is categorized under:

RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems

RNA Evolution and Genomics > Computational Analyses of RNA

Translation > Translation Regulation
Conditioning and Interpretation Shifts
Authors: Romeijn Jan-Willem
Published: June 2012

This paper develops a probabilistic model of belief change under interpretation shifts, in the context of a problem case from dynamic epistemic logic. Van Benthem [4] has shown that a particular kind of belief change, typical for dynamic epistemic logic, cannot be modelled by standard Bayesian conditioning. I argue that the problems described by van Benthem come about because the belief change alters the semantics in which the change is supposed to be modelled: the new information induces a shift in the interpretation of the sentences. In this paper I show that interpretation shifts can be modeled in terms of updating by conditioning. The model derives from the knowledge structures developed by Fagin et al [8], and hinges on a distinction between the propositional and informational content of sentences. Finally, I show that Dempster-Shafer theory provides the appropriate probability kinematics for the model.
An Introduction to Africana Philosophy
Authors: Gordon Lewis R.
Published: June 2012

In this undergraduate textbook Lewis R. Gordon offers the first comprehensive treatment of Africana philosophy, beginning with the emergence of an Africana (i.e. African diasporic) consciousness in the Afro-Arabic world of the Middle Ages. He argues that much of modern thought emerged out of early conflicts between Islam and Christianity that culminated in the expulsion of the Moors from the Iberian Peninsula, and from the subsequent expansion of racism, enslavement, and colonialism which in their turn stimulated reflections on reason, liberation, and the meaning of being human. His book takes the student reader on a journey from Africa through Europe, North and South America, the Caribbean, and back to Africa, as he explores the challenges posed to our understanding of knowledge and freedom today, and the response to them which can be found within Africana philosophy.
Authoritarianism and Polarization in American Politics
Authors: Hetherington Marc J. , Weiler Jonathan D.
Published: June 2012

Although politics at the elite level has been polarized for some time, a scholarly controversy has raged over whether ordinary Americans are polarized. This book argues that they are and that the reason is growing polarization of worldviews - what guides people's view of right and wrong and good and evil. These differences in worldview are rooted in what Marc J. Hetherington and Jonathan D. Weiler describe as authoritarianism. They show that differences of opinion concerning the most provocative issues on the contemporary issue agenda - about race, gay marriage, illegal immigration, and the use of force to resolve security problems - reflect differences in individuals' levels of authoritarianism. Events and strategic political decisions have conspired to make all these considerations more salient. The authors demonstrate that the left and the right have coalesced around these opposing worldviews, which has provided politics with more incandescent hues than before.
Bayesian Econometric Methods
Authors: Koop Gary , Poirier Dale J. , Tobias Justin L.
Published: June 2012

This volume in the Econometric Exercises series contains questions and answers to provide students with useful practice, as they attempt to master Bayesian econometrics. In addition to many theoretical exercises, this book contains exercises designed to develop the computational tools used in modern Bayesian econometrics. The latter half of the book contains exercises that show how these theoretical and computational skills are combined in practice, to carry out Bayesian inference in a wide variety of models commonly used by econometricians. Aimed primarily at advanced undergraduate and graduate students studying econometrics, this book may also be useful for students studying finance, marketing, agricultural economics, business economics or, more generally, any field which uses statistics. The book also comes equipped with a supporting website containing all the relevant data sets and MATLAB computer programs for solving the computational exercises.
Bayesian Methods for Ecology
Authors: McCarthy Michael A.
Published: June 2012

The interest in using Bayesian methods in ecology is increasing, however many ecologists have difficulty with conducting the required analyses. McCarthy bridges that gap, using a clear and accessible style. The text also incorporates case studies to demonstrate mark-recapture analysis, development of population models and the use of subjective judgement. The advantages of Bayesian methods, are also described here, for example, the incorporation of any relevant prior information and the ability to assess the evidence in favour of competing hypotheses. Free software is available as well as an accompanying web-site containing the data files and WinBUGS codes. Bayesian Methods for Ecology will appeal to academic researchers, upper undergraduate and graduate students of Ecology.