bluuebunny/crossref_metadata_2025 huggingface dataset:
Research progress on the preparation and application of monodisperse cationic polymer latex particles
Authors: Liu Qingquan , Li Yanlu , Duan Yinxiang , Zhou Hu
Published: August 2012

This review is focused on the features, preparation and applications of uniform cationic polymer latex particles, as well as on the formation mechanism of uniform latex particles. Substantial progress in the size and shape control of polymer latex particles has been made using several methods such as dispersion polymerization, conventional emulsion polymerization, surfactant‐free emulsion polymerization and seeded emulsion polymerization. Uniform cationic polymer latex particles have wide applications such as drug carriers, diagnostics, templates and additives. However, two major problems are the inhomogeneous size and low surface charge density, which limit further functionalization and the application of cationic polymer latex particles. Finally, the future trends and perspectives are described. Copyright © 2012 Society of Chemical Industry
High‐resolution ultra‐high mass spectrometry: Increasing the m/z range of protein analysis
Authors: Chen Huijuan , Lee Jeonghoon , Reilly Peter T. A.
Published: August 2012

The proof of principle for high‐resolution TOF mass analysis spanning the entire range of intact singly charged proteins has recently been demonstrated. The centers of the isotope distributions of individual proteins in a complex distribution can be defined to within 0.5 Da or better up to 200 kDa with internal calibration. This achievement will have an enormous effect on the process of routine protein analysis over the next few years as the technology mainstreams. The greatest obstacle to high‐resolution in the ultra‐high mass range (m/z > 20 000) is the expansion‐induced kinetic energy (KE) and its spread. The solution to this problem is to trap the ions in a buffer gas so that the motion of the ions can be completely defined by the applied fields. If this can accomplished without mass dependence, then any ion, regardless of size, can be mass analyzed with high resolution. This article discusses the methodology that we used to capture atmosphere sampled singly charged proteins in vacuum at a point just before they enter the mass analyzer to completely eliminate the expansion‐induced KE. We then used digitally created quadrupole waveforms to inject the ions into the mass analyzer in a well‐collimated plug with a controlled amount of KE. Trapping the ions to remove the expansion‐induced KE and then electrodynamically manipulating the ions are the key steps to high‐resolution mass analysis at any value of m/z. The impact of this technology will be discussed.
Substituent‐induced regioselective hydroxylation of the aromatic C–H bond on naphthalene with metachloroperbenzoic acid catalyzed by F20TPPMnCl
Authors: Chen Chang‐Di , Sheng Wen‐Bing , Shi Guo‐Jun , Guo Can‐Cheng
Published: August 2012

The regioselective hydroxylation of the aromatic C–H bond on a series of naphthalenes with different β‐substituent R (R = H, Me, Et, i‐Pr, OMe, COOH, Br, etc.) was studied, and the substituent effect on the regioselectivity was investigated. The electron‐donating substituent afforded the aromatic C–H bond hydroxylation at the 1α position with more than 80% selectivity, while the electron‐withdrawing substituent afforded the aromatic C–H bond hydroxylation at the 4α position with more than 60% selectivity of β‐substituted naphthalene hydroxylated with metachloroperbenzoic acid catalyzed by tetrakis(pentafluorophenyl)porphyrin manganese(III) chloride. The research showed that the steric and electronic effects of the substituent appeared to play a significant role in determining the regioselectivity, and the electronic effect was of more importance than the steric effect of the substituent in the current situation. The studies may provide additional proofs for the stepwise mechanism of the aromatic C–H bond hydroxylation through a cationic intermediate. Copyright © 2012 John Wiley & Sons, Ltd.
Hetero‐difunctional dimers as building blocks for the synthesis of poly(amidoamine)s with hetero‐difunctional chain terminals and their derivatives
Authors: Ferruti Paolo , Mauro Nicolò , Manfredi Amedea , Ranucci Elisabetta
Published: August 2012

This article reports on a simple and straightforward preparation method of poly(amidoamine)s (PAAs) with hetero‐difunctional chain ends as well as of several up to now hardly obtainable PAA derivatives of biotechnological interest, such as for instance PAAs of controlled molecular weight and narrow polydispersity mono‐functionalized at one end with an acrylamide group, PAAs with star‐like molecular architecture, graft‐PAA‐protein conjugates, “tadpole‐like” PAA conjugates with hydrophobic moieties able to self assemble into nanoparticles in aqueous media. The key step was to design suitable building blocks consisting of hetero‐difunctional dimers (HDDs). In particular, the HDDs considered were the mono‐addition products of bis‐sec‐amines and bisacrylamides expected to give PAAs of proven biomedical potential and were obtained as hydrochlorides or trifluoroacetates. In this form, they could be indefinitely kept dormant at 0–5 °C in the dry state, whereas at room temperature and in aqueous media, they polymerized at pH > 7.5. The preparation of the above‐cited PAA derivatives did not necessarily involve the preliminary synthesis of hetero‐difunctional PAAs but was directly achieved by one‐pot polymerization of HDDs in the presence of the substrates of interest. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Synthesis of polyarylacetylenes by γ‐ray‐induced polymerization of terminal alkynes. Nanostructures of ortho‐substituted derivatives
Authors: Bassetti Mauro , Fratoddi Ilaria , Lilla Laura , Pasquini Chiara , Vittoria Russo Maria , Ursini Ornella
Published: August 2012

Terminal aryl alkynes RC6H4CCH with substituents of different electronic properties and ring position (R = H, 4‐CF3, 4‐OMe, 2‐CF3, 2‐OMe, 2‐Me) were exposed to γ‐radiation (50–400 kGy) in organic solvents (hexane, 1,4‐dioxane, ethylacetate, methanol, tetrahydrofuran), at room temperature. The effects arising from substituent, solvent, dilution, and radiation dose allowed to define the conditions suitable for polymerization, which was favored in methanol at increasing dilution of the alkyne. Ortho‐substitution represented the key structural element in the substrate, and the derived polyarylacetylenes were characterized in detail, including gel permeation chromatography, thermal analysis, infrared, NMR, UV–vis, fluorescence, and scanning electron microscope spectroscopy. The results are consistent with the formation of irregular polymers mainly composed of trans‐transoid chains. Controlled aggregation of the polymers by means of an osmosis‐based procedure in solvent/non‐solvent mixtures allowed the formation of nanostructured materials, in particular of hollow nanospheres from THF/water. The methodology sets the basis for the development of γ‐rays‐induced polymerization of alkynes, in a transition metal catalyst‐free environment. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Aqueous solution behavior of comb‐shaped poly(2‐ethyl‐2‐oxazoline)
Authors: Weber Christine , Rogers Sarah , Vollrath Antje , Hoeppener Stephanie , Rudolph Tobias , Fritz Nicole , Hoogenboom Richard , Schubert Ulrich S.
Published: August 2012

A series of comb polymers consisting of a methacrylate backbone and poly(2‐ethyl‐2‐oxazoline) (PEtOx) side chains was synthesized by a combination of cationic ring‐opening polymerization and reversible addition–fragmentation chain transfer polymerization. Small‐angle neutron scattering (SANS) studies revealed a transition from an ellipsoidal to a cylindrical conformation in D2O around a backbone degree of polymerization of 30. Comb‐shaped PEtOx has lowered Tg values but a similar elution behavior in liquid chromatography under critical conditions in comparison to its linear analog was observed. The lower critical solution temperature behavior of the polymers was investigated by turbidimetry, dynamic light scattering, transmission electron microscopy, and SANS revealing decreasing Tcp in aqueous solution with increasing molar mass, the presence of very few aggregated structures below Tcp, a contraction of the macromolecules at temperatures 5 °C above Tcp but no severe conformational change of the cylindrical structure. In addition, the phase diagram including cloud point and coexistence curve was developed showing an LCST of 75 °C of the binary mixture poly[oligo(2‐ethyl‐2‐oxazoline)methacrylate]/water. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Relationships between perceived diagnostic disclosure, patient characteristics, psychological distress and illness perceptions in Indian cancer patients
Authors: Chittem Mahati , Norman Paul , Harris Peter R.
Published: August 2012

Objective

Non‐disclosure of a cancer diagnosis is a common practice in many Asian cultures where family‐based medical decision making is the norm. The present study sought to compare Indian cancer patients who were aware versus unaware of their cancer diagnosis on a range of patient characteristics, levels of psychological distress and illness perceptions.

Methods

A sample of 329 Indian cancer patients were interviewed about their understanding of their illness (to assess awareness of a cancer diagnosis) and administered the following measures: the modified Rotterdam Symptom Checklist, the Hospital Anxiety and Depression Scale, and the Brief Illness Perceptions Questionnaire. Demographic and medical details were also obtained.

Results

Over half of the sample (54.1%) was unaware of their cancer diagnosis. A logistic regression analysis predicting perceived diagnostic disclosure indicated that awareness of a cancer diagnosis was associated with being involved in medical decisions, receiving multiple treatments, longer treatment durations, greater perceived understanding of one's illness (illness coherence) and citing a cause for one's illness.

Conclusions

The results highlight the importance of the context in which decisions about the patient's illness are made (e.g. by whom) as well as illness perceptions relating to patients' understanding of their illness. Copyright © 2012 John Wiley & Sons, Ltd.
Calorimetric and spectroscopic investigation of the interaction between the C‐terminal domain of Enzyme I and its ligands
Authors: Yun Young‐Joo , Suh Jeong‐Yong
Published: August 2012

Enzyme I initiates a series of phosphotransfer reactions during sugar uptake in the bacterial phosphotransferase system. Here, we have isolated a stable recombinant C‐terminal domain of Enzyme I (EIC) of Escherichia coli and characterized its interaction with the N‐terminal domain of Enzyme I (EIN) and also with various ligands. EIC can phosphorylate EIN, but their binding is transient regardless of the presence of phosphoenolpyruvate (PEP). Circular dichroism and NMR indicate that ligand binding to EIC induces changes near aromatic groups but not in the secondary structure of EIC. Binding of PEP to EIC is an endothermic reaction with the equilibrium dissociation constant (KD) of 0.28 mM, whereas binding of the inhibitor oxalate is an exothermic reaction with KD of 0.66 mM from calorimetry. The binding thermodynamics of EIC and PEP compared to that of Enzyme I (EI) and PEP reveals that domain–domain motion in EI can contribute as large as ∼−3.2 kcal/mol toward PEP binding.
ALS herbicide resistance mutations in Raphanus raphanistrum: evaluation of pleiotropic effects on vegetative growth and ALS activity
Authors: Li Mei , Yu Qin , Han Heping , Vila‐Aiub Martin , Powles Stephen B
Published: August 2012

Background

Gene mutations that endow herbicide resistance may cause pleiotropic effects on plant ecology and physiology. This paper reports on the effect of a number of known and novel target‐site resistance mutations of theALSgene (Ala‐122‐Tyr, Pro‐197‐Ser, Asp‐376‐Glu or Trp‐574‐Leu) on vegetative growth traits of the weedRaphanus raphanistrum.

Results

The results from a series of experiments have indicated that none of theseALSresistance mutations imposes negative pleiotropic effects on relative growth rate (RGR), photosynthesis and resource‐competitive ability inR. raphanistrumplants. The absence of pleiotropic effects on plant growth occurs in spite of increased (Ala‐122‐Tyr, Pro‐197‐Ser, Asp‐376‐Glu) and decreased (Trp‐574‐Leu) extractable ALSactivity.

Conclusion

The absence of detrimental pleiotropic effects on plant growth associated with theALStarget‐site resistance mutations reported here is a contributing factor in resistance alleles being at relatively high frequencies inALS‐herbicide‐unselectedR. raphanistrumpopulations.© 2012 Society of Chemical Industry
Formation mechanism of cross‐linking Maillard compounds in peptide–xylose systems
Authors: Liu Ping , Zhang Xiaoming , Huang Meigui , Song Shiqing , Nsor‐Atindana John
Published: August 2012

The formation mechanism of Maillard peptides was explored in Maillard reaction through diglycine/glutathione(GSH)/(Cys‐Glu‐Lys‐His‐Ile‐Met)–xlyose systems by heating at 120 °C for 30–120 min. Maximum fluorescence intensity of Maillard reaction products (MRPs) with an emission wavelength of 420~430 nm in all systems was observed, and the intensity values were proportional to the heating time. Taken diglycine/GSH–[13C5]xylose systems as a control, it was proposed that the compounds with high m/z values of 379 and 616 have the high molecular weight (HMW) products formed by cross‐linking of peptides and sugar. In (Cys‐Glu‐Lys‐His‐Ile‐Met)–xylose system, the m/z value of HMW MRPs was not observed, which might be due to the weak signals of these products. According to the results of gel permeation chromatography, HMW MRPs were formed by Maillard reaction, especially in (Cys‐Glu‐Lys‐His‐Ile‐Met)–xylose system, the percentage of Maillard peptides reached 52.90%. It was concluded that Maillard peptides can be prepared through the cross‐linking of sugar and small peptides with a certain MW range. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.
Laparoscopic and robotic distal gastrectomy for gastrointestinal stromal tumour: case report
Authors: Ortiz‐Oshiro Elena , Exposito Patricia Benito , Sierra Jesus Moreno , Gonzalez Jesus Diaz , Barbosa Diego Sierra , Fernandez‐Represa Jesus Alvarez
Published: August 2012

Background

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the digestive tract. The most frequent site of occurrence is the stomach. Due to the high potential for malignancy of GIST, resection should be the first‐line treatment. Minimally invasive surgery may be used for surgical resection of GISTs.

Methods

We describe a case of laparoscopic and robotic distal gastrectomy in a patient with diagnosis of GIST in the gastric antrum. Laparoscopy was useful for dissection and a da Vinci robot was used for Roux‐en‐Y reconstruction.

Results

The postoperative course was uneventful.

Conclusions

Minimally invasive surgery offers benefits compared to open surgery, and laparoscopic and robot‐assisted gastrectomy for the treatment of GIST could be technically feasible and safe because of the advantageous movements provided by the robotic arms. Copyright © 2012 John Wiley & Sons, Ltd.
Application of maximum elevation angle probability density function to macroscopic selection diversity in low earth orbiting satellite constellation systems
Authors: Li Sheng‐Yi , Wang Kai‐Yuan
Published: August 2012

In a low earth orbiting satellite constellation of communication satellites, the so‐called macroscopic selection‐diversity (SD) scheme selects the satellite with the maximum elevation angle among the visible satellites as being capable of providing the best quality link for signal propagation. To evaluate the performance of this scheme, we developed a model based on macroscopic SD to describe the probability density function of the maximum elevation angles from an earth station to each visible satellite. The model has the advantage of not involving orbital simulations for data collection, thus avoiding statistical processing as well as curve fitting. We evaluated the model by using it to simulate the bit‐error‐rate performance of binary‐phase‐shift‐keying modulation in the Globalstart‐like Walker 48/8/1 satellite constellation. Copyright © 2012 John Wiley & Sons, Ltd.
Scientific considerations for assessing biosimilar products
Authors: Chow Shein‐Chung , Wang Jun , Endrenyi Laszlo , Lachenbruch Peter A.
Published: August 2012

The problem for assessing biosimilarity and drug interchangeability of follow‐on biologics (biosimilar products) is studied. Unlike the generic products, the development of biosimilar products is much more complicated because of fundamental differences in functional structures and manufacturing processes. As a result, the criteria and standard methods for the design and analysis of bioequivalence assessment of generic drug products may not be directly applicable to assessing biosimilarity of biosimilar products. In this article, we provide some scientific considerations for criteria, design, and analysis regarding the assessment of biosimilarity and drug interchangeability of biosimilar products. In addition, we discuss scientific and practical issues raised at the 2010 FDA public hearing and the 2011 FDA public meeting on biosimilar products. Copyright © 2012 John Wiley & Sons, Ltd.
Current issues in clinical trials: standing on the shoulders of Jerome Cornfield
Authors: Ellenberg Susan S.
Published: August 2012

Jerome Cornfield was one of the leading biostatisticians of the mid‐20th century and made major contributions to the methods and practice of statistics in many areas. One of Cornfield's major areas of interest was clinical trials. He considered and wrote about many of the issues that continue to concern clinical trialists today. His work ranged from philosophical treatises about the approaches to inference from clinical trials, all the way to assessing the details of the conduct of a particular trial to determine how to best interpret the results. It is interesting to see how many of today's ‘hot topics’ in clinical trials methodology were addressed in Cornfield's works in the 1960s and 1970s. Copyright © 2012 John Wiley & Sons, Ltd.
Microfluidics for Manipulating Cells
Authors: Mu Xuan , Zheng Wenfu , Sun Jiashu , Zhang Wei , Jiang Xingyu
Published: August 2012

Microfluidics, a toolbox comprising methods for precise manipulation of fluids at small length scales (micrometers to millimeters), has become useful for manipulating cells. Its uses range from dynamic management of cellular interactions to high‐throughput screening of cells, and to precise analysis of chemical contents in single cells. Microfluidics demonstrates a completely new perspective and an excellent practical way to manipulate cells for solving various needs in biology and medicine. This review introduces and comments on recent achievements and challenges of using microfluidics to manipulate and analyze cells. It is believed that microfluidics will assume an even greater role in the mechanistic understanding of cell biology and, eventually, in clinical applications.
Anthropocentrism and Well‐being: A Way Out of the Lobster Pot?
Authors: McIntyre‐Mills Janet Judy
Published: August 2012

The paper is focused on exploring the following questions: How can policy makers develop agreement on (i) what constitutes and (ii) supports the well‐being of the planet, rather than the gross domestic product of a nation state? How can we design Participatory Democracy and Systemic Governance to (i) support the appropriate distribution and consumption of resources and (ii) protect social and environmental diversity and justice? The paper discusses thinking and practice to test out ‘technologies of humility’ in the sense used by Jasonoff. It suggests the potential for a hybrid bricolage of laws and praxis to enable the transformation of our designs for living to support biospheres. Biospheres need to be understood as oceans, rivers, the air we breathe, the earth that supports the food chain and the universe of which we are a part. In other words, this reframed definition extends beyond the original definitions of that which was outside the boundaries of a nation state. Instead, it locates nation states within the regional biosphere, which sustains them. Caretaking needs to be rooted in many kinds of knowledge to: (i) ‘De‐centre’ anthropocentricism (by drawing on the work of Rose Bird, Wynne and Mathews); and (ii) ‘Address’ the convergent social, cultural and economic crisis. The challenge is to ‘promote’ an ever extending or widening circle of solidarity to ‘care for’ the next generation of life. It also requires the creation of new global narratives arising out of a cross‐pollination of spiritual ideas from a range of religious and spiritual practices. This appreciation of narratives could inform discursive engagement to help establish ethical processes to support well‐being (Braun, et al.) at a post national level. This requires discursive engagement as well as participatory governance to enable accountability and whistleblowing on the misuse of power or resources. Copyright © 2012 John Wiley & Sons, Ltd.
Governance Matters and Entrepreneurial Activities
Authors: Fereidouni Hassan Gholipour , Masron Tajul Ariffin
Published: August 2012

This study uses Global Entrepreneurship Monitor (GEM) and World Bank Group Entrepreneurship Survey data from 40 countries from 2002 to 2008 to examine the linkage between governance matters and entrepreneurial activities. Based on the conceptual model of GEM and by using fixed‐effects panel analysis, the results show that political stability and absence of violence, rule of law, and control of corruption are highly significant determinants of entrepreneurial activities. © 2012 Wiley Periodicals, Inc.
The Faltering Solid Organ Donor Pool in the United States (2001–2010)
Authors: Saidi Reza F. , Markmann James F. , Jabbour Nicolas , Li YouFu , Shah Shimul A. , Cosimi A. B. , Bozorgzadeh Adel
Published: August 2012

Background

Organ shortage is the greatest challenge facing the field of organ transplantation today. Use of more organs of marginal quality has been advocated to address the shortage.

Method

We examined the pattern of donation and organ use in the United States as shown in the Organ Procurement and Transplantation Network/United Network for Organ Sharing database of individuals who were consented for and progressed to organ donation between January 2001 and December 2010.

Results

There were 66,421 living donors and 73,359 deceased donors, including 67,583 (92.1 %) identified as donation after brain death and 5,776 (7.9 %) as donation after circulatory death (DCD). Comparing two periods, era 1 (01/2001–12/2005) and era 2 (01/2006–12/2010), the number of deceased donors increased by 20.3 % from 33,300 to 40,059 while there was a trend for decreasing living donation. The DCD subgroup increased from 4.9 to 11.7 % comparing the two eras. A significant increase in cardiovascular/cerebrovascular disease as a cause of death was also noted, from 38.1 % in era 1 to 56.1 % in era 2 (p < 0.001), as was a corresponding decrease in the number of deaths due to head trauma (48.8 vs. 34.9 %). The overall discard rate also increased from 13,411 (11.5 %) in era 1 to 19,516 (13.7 %) in era 2. This increase in discards was especially prominent in the DCD group [440 (20.9 %) in era 1 vs. 2,089 (24.9 %) in era 2].

Conclusions

We detect a significant change in pattern of organ donation and use in the last decade in the United States. The transplant community should consider every precaution to prevent the decay of organ quality and to improve the use of marginal organs.
Relationships among Teachers’ Knowledge and Beliefs Regarding the Teaching of Evolution: A Case for Turkey
Authors: Tekkaya Ceren , Akyol Gülsüm , Sungur Semra
Published: August 2012

The research study investigated the possible associations among science and biology teachers’ knowledge and belief variables concerning teaching evolution in science and biology classes. Specifically, this study examined how a set of variables including teachers’ understanding of evolution and nature of science (NOS) is related to the set of variables including teachers’ acceptance of evolution and perceptions of teaching evolution (i.e., perceptions of the necessity of addressing evolution in their classrooms, perceptions of the factors that impede addressing evolution in their classrooms, and personal science teaching efficacy beliefs regarding evolution). Data were collected from science and biology teachers through administration of Evolution Content Knowledge Test, Measure of Acceptance of the Theory of Evolution, Nature of Science as Argument Questionnaire and Teachers’ Perceptions of Teaching Evolution Scale. Canonical correlation analysis findings suggested that teachers who had thorough understanding of evolution and NOS were likely to both accept the scientific validity of evolution and believe the necessity of addressing evolution in the classrooms. On the other hand, teachers with thorough understanding of evolution and NOS did not necessarily believe that they have a stronger sense of self-efficacy beliefs regarding teaching evolution and that there are fewer obstacles to addressing evolution in the classroom. The research is significant in that it provides empirical evidence clarifying the interactions between teachers’ understanding and beliefs in teaching evolution. Implications for science teacher education are discussed.
A direct numerical simulation study of turbulence and flame structure in transverse jets analysed in jet-trajectory based coordinates
Authors: Grout R. W. , Gruber A. , Kolla H. , Bremer P.-T. , Bennett J. C. , Gyulassy A. , Chen J. H.
Published: August 2012

An${\mathrm{H} }_{2} / {\mathrm{N} }_{2} $jet in cross-flow (JICF) of air is studied using three-dimensional direct numerical simulation with and without chemical reaction in order to investigate the role of the complex JICF turbulent flow field in the mechanism of fast fuel-oxidant mixing and of aerodynamic flame stabilization in the near field of the jet nozzle. Focus is on delineating the flow/mixing/chemistry conditions that are necessary and/or sufficient to achieve flame anchoring that ultimately enables the formulation of more reliable and precise guidelines for design of fuel injection nozzles. A mixture averaged diffusion formulation that includes the effect of thermal diffusion is used along with a detailed chemical kinetics mechanism for hydrogen–air combustion. A new parametrization technique is used to describe the jet trajectory: solution of Laplace’s equation upon, and then within, an opportune scalar surface anchored by Dirichlet boundary conditions at the jet nozzle and plume exit from the domain provides a smoothly varying field along the jet path. The surface is selected to describe the scalar mixing and reaction associated with a transverse jet. The derived field,$j(\mathbi{x})$, is used as a condition to mark the position along the natural jet trajectory when analysing the variation of relevant flow, mixing and reaction quantities in the present direct numerical simulation (DNS) datasets. Results indicate the presence of a correlation between the flame base location in parameter space and a region of low velocity magnitude, high enstrophy, high mixing rate and high equivalence ratio (flame root region). Instantaneously, a variety of vortical structures, well known from the literature as important contributors to fuel-oxidant mixing, are observed in both inert and reactive cases with a considerable span in length scales. Moreover, instantaneous plots from reactive cases illustrate that the most upstream flame tongues propagate close to the trailing edge of the fuel jet potential core near the jet shear layer vortex shedding position. Some degree of asymmetry with respect to the domain mid-plane in the spanwise direction is observed in the averaged fields, both for the inert and reactive cases.
Feedback control of cavity flow oscillations using simple linear models
Authors: Illingworth Simon J. , Morgans Aimee S. , Rowley Clarence W.
Published: August 2012

Using data from direct numerical simulations, linear models of the compressible flow past a rectangular cavity are found. The emphasis is on forming simple models which capture the input–output behaviour of the system, and which are useful for feedback controller design. Two different approaches for finding a linear model are investigated. The first involves using input–output data of the linearized cavity flow to form a balanced, reduced-order model directly. The second approach is conceptual, and involves modelling each element of the flow physics separately using simple analytical expressions, the parameters of which are chosen based on simulation data at salient points in the cavity’s computational domain. Both models are validated: first in the time domain by comparing their impulse responses to that of the full system in direct numerical simulations; and second in the frequency domain by comparing their frequency responses. Finally, the validity of both linear models is shown most clearly by using them for feedback controller design, and then applying each controller in direct numerical simulations. Both controllers completely eliminate oscillations, and demonstrate the advantages of model-based feedback controllers, even when the models upon which they are based are very simple.
Direct numerical simulation of premixed flame boundary layer flashback in turbulent channel flow
Authors: Gruber A. , Chen J. H. , Valiev D. , Law C. K.
Published: August 2012

Direct numerical simulations are performed to investigate the transient upstream propagation (flashback) of premixed hydrogen–air flames in the boundary layer of a fully developed turbulent channel flow. Results show that the well-known near-wall velocity fluctuations pattern found in turbulent boundary layers triggers wrinkling of the initially flat flame sheet as it starts propagating against the main flow direction, and that the structure of the characteristic streaks of the turbulent boundary layer ultimately has an important impact on the resulting flame shape and on its propagation mechanism. It is observed that the leading edges of the upstream-propagating premixed flame are always located in the near-wall region of the channel and assume the shape of several smooth, curved bulges propagating upstream side by side in the spanwise direction and convex towards the reactant side of the flame. These leading-edge flame bulges are separated by thin regions of spiky flame cusps pointing towards the product side at the trailing edges of the flame. Analysis of the instantaneous velocity fields clearly reveals the existence, on the reactant side of the flame sheet, of backflow pockets that extend well above the wall-quenching distance. There is a strong correspondence between each of the backflow pockets and a leading edge convex flame bulge. Likewise, high-speed streaks of fast flowing fluid are found to be always colocated with the spiky flame cusps pointing towards the product side of the flame. It is suggested that the origin of the formation of the backflow pockets, along with the subsequent mutual feedback mechanism, is due to the interaction of the approaching streaky turbulent flow pattern with the Darrieus–Landau hydrodynamic instability and pressure fluctuations triggered by the flame sheet. Moreover, the presence of the backflow pockets, coupled with the associated hydrodynamic instability and pressure–flow field interaction, greatly facilitate flame propagation in turbulent boundary layers and ultimately results in high flashback velocities that increase proportionately with pressure.
Novel microsatellite DNA markers indicate strict parthenogenesis and few genotypes in the invasive willow sawflyNematus oligospilus
Authors: Caron V. , Norgate M. , Ede F.J. , Nyman T. , Sunnucks P.
Published: August 2012

Invasive organisms can have major impacts on the environment. Some invasive organisms are parthenogenetic in their invasive range and, therefore, exist as a number of asexual lineages (=clones). Determining the reproductive mode of invasive species has important implications for understanding the evolutionary genetics of such species, more especially, for management-relevant traits. The willow sawflyNematus oligospilusFörster (Hymenoptera: Tenthredinidae) has been introduced unintentionally into several countries in the Southern Hemisphere where it has subsequently become invasive. To assess the population expansion, reproductive mode and host-plant relationships of this insect, microsatellite markers were developed and applied to natural populations sampled from the native and expanded range, along with sequencing of the cytochrome-oxidase I mitochondrial DNA (mtDNA) region. Other tenthredinids across a spectrum of taxonomic similarity toN. oligospilusand having a range of life strategies were also tested. Strict parthenogenesis was apparent within invasiveN. oligospiluspopulations throughout the Southern Hemisphere, which comprised only a small number of genotypes. Sequences of mtDNA were identical for all individuals tested in the invasive range. The microsatellite markers were used successfully in several sawfly species, especiallyNematusspp. and other genera of the Nematini tribe, with the degree of success inversely related to genetic divergence as estimated from COI sequences. The confirmation of parthenogenetic reproduction inN. oligospilusand the fact that it has a very limited pool of genotypes have important implications for understanding and managing this species and its biology, including in terms of phenotypic diversity, host relationships, implications for spread and future adaptive change. It would appear to be an excellent model study system for understanding evolution of invasive parthenogens that diverge without sexual reproduction and genetic recombination.
Cohomological uniqueness of some p-groups
Authors: Díaz Antonio , Ruiz Albert , Viruel Antonio
Published: August 2012

We consider classifying spaces of a family of p-groups and prove that mod p cohomology enriched with Bockstein spectral sequences determines their homotopy type among p-completed CW-complexes.
Clandestine Recruitment Networks in the Bight of Biafra: Fernando Pó's Answer to the Labour Question, 1926–1945
Authors: Martino Enrique
Published: August 2012

The “Labour Question”, a well-known obsession pervading the archives of Africa, was posed by colonial rulers as a calculated question of scarcity and coercion. On the Spanish plantation island of Fernando Pó the shortage and coercive recruitment of labour was particularly intense. This article examines two distinct clandestine labour recruitment operations that took hold of Rio Muni and eastern Nigeria, on the east and the north of the Bight of Biafra. The trails of the recruitment networks were successfully constructed by the specifically aligned “mediators” of kinship, ethnicity, money, law, commodities, and administration. The conceptual focus on flat “mediators” follows Bruno Latour's sociology of associations and has been set against the concept of an “intermediary” that serves to join and uphold the structure/agency and global/local binaries.
Synchronous spontaneous cerebrospinal fluid leaks in the nose and ear
Authors: Schraven S P , Bisdas S , Wagner W
Published: August 2012

Objective:

The majority of spontaneous cerebrospinal fluid leaks occur at the anterior skull base; few cases at the temporal bone have been described. There have been no previous reports of synchronous leaks at the anterior skull base and temporal bone in the same patient.

Methods:

Case report and brief review of management of spontaneous cerebrospinal fluid leaks in the nose and ear.

Case report:

A 34-year-old, pregnant woman presented with watery nasal discharge and unilateral middle-ear effusion. The nasal and ear secretions both proved to be cerebrospinal fluid. Radiological imaging showed defects in both the ethmoid roof and the mastoid roof (middle cranial fossa). These defects were surgically closed using duraplasties.

Conclusion:

A literature review indicated that this is the first reported case of synchronous spontaneous cerebrospinal fluid leaks via the anterior skull base and temporal bone.
Diel variations in Centropages tenuiremis (Copepoda) feeding, spawning and its relationship with temperature
Authors: Wu Lisheng , Gao Qiujing , Wang Guizhong , Liu Yusha
Published: August 2012

Diel rhythms in feeding and spawning were investigated in Centropages tenuiremis from Xiamen Bay in March to May, 2006. Circular statistics were used to determine the peak time of spawning. The results showed that the feeding activities of females were stably higher at night-time, and there was a remarkable earlier shift in spawning peak time with warmer seawater. Thus, the lag times between peak times of gut pigment content and spawning were shortened with the increase of temperature. It suggested that there was a direct effect of feeding rhythms on egg production variations in copepods, and the seawater temperature would work on the converting time and then influence the spawning peak time. So the effect of temperature cannot be ignored in the investigation of the effects of feeding on egg production.
The safety of oats in the dietary treatment of coeliac disease
Authors: Richman Emile
Published: August 2012

Coeliac disease is a permanent inflammatory disorder of the small bowel affecting approximately 1% of the population. The only effective treatment that exists is exclusion of gluten from the diet. The present paper aims to review the literature as to whether oats are safe to eat for people with coeliac disease. Much data exist on the restrictive nature that adhering to a gluten-free diet imposes on an individual. If oats could be eaten, this would help reduce the restrictive nature of the diet. This in turn could lead to an increase in the quality of life. Oats are of high-nutritional value, providing a rich source of fibre, vitamins and minerals. The fibre source contains soluble fibre which is believed to help reduce LDL-cholesterol. A systematic review of the literature was conducted. Earlier studies conducted are difficult to compare as they used different methodologies and it is not known whether samples of oats in the studies were contaminated with gluten from other cereals. Many studies reviewed do not state the strain of oat used. Recent research has suggested that it may only be in certain strains of oats which could produce a toxic response to people with coeliac disease. In conclusion, research suggests that the risk from consuming oats may be less harmful than first thought; however, may vary according to the strain of oat. Handling that risk in clinical practice remains controversial.
Shifted risk preferences in pathological gambling
Authors: Ligneul R. , Sescousse G. , Barbalat G. , Domenech P. , Dreher J.-C.
Published: August 2012

Background

Pathological gambling (PG) is an impulse control disorder characterized by excessive monetary risk seeking in the face of negative consequences. We used tools from the field of behavioral economics to refine our description of risk-taking behavior in pathological gamblers. This theoretical framework allowed us to confront two hypotheses: (1) pathological gamblers distort winning probabilities more than controls; and (2) pathological gamblers merely overweight the whole probability range.

Method

Eighteen pathological gamblers and 20 matched healthy participants performed a decision-making task involving choices between safe amounts of money and risky gambles. The online adjustment of safe amounts, depending on participants' decisions, allowed us to compute ‘certainty equivalents’ reflecting the subjective probability weight associated with each gamble. The behavioral data were then fitted with a mathematical function known as the ‘probability weighting function’, allowing us to disentangle our two hypotheses.

Results

The results favored the second hypothesis, suggesting that pathological gamblers' behavior reflects economic preferences globally shifted towards risk, rather than excessively distorted probability weighting. A mathematical parameter (elevation parameter) estimated by our fitting procedure was found to correlate with gambling severity among pathological gamblers, and with gambling affinity among controls.

Conclusions

PG is associated with a specific pattern of economic preferences, characterized by a global (i.e. probability independent) shift towards risky options. The observed correlation with gambling severity suggests that the present ‘certainty equivalent’ task may be relevant for clinical use.
Towards a universal model of reading
Authors: Frost Ram
Published: August 2012

In the last decade, reading research has seen a paradigmatic shift. A new wave of computational models of orthographic processing that offer various forms of noisy position or context-sensitive coding have revolutionized the field of visual word recognition. The influx of such models stems mainly from consistent findings, coming mostly from European languages, regarding an apparent insensitivity of skilled readers to letter order. Underlying the current revolution is the theoretical assumption that the insensitivity of readers to letter order reflects the special way in which the human brain encodes the position of letters in printed words. The present article discusses the theoretical shortcomings and misconceptions of this approach to visual word recognition. A systematic review of data obtained from a variety of languages demonstrates that letter-order insensitivity isneithera general property of the cognitive systemnora property of the brain in encoding letters. Rather, it is avariantand idiosyncratic characteristic of some languages, mostly European, reflecting a strategy of optimizing encoding resources, given the specific structure of words. Since the main goal of reading research is to develop theories that describe thefundamental and invariantphenomena of reading across orthographies, an alternative approach to model visual word recognition is offered. The dimensions of a possible universal model of reading, which outlines the common cognitive operations involved in orthographic processing in all writing systems, are discussed.
Explaining word recognition, reading, the universe, and beyond: A modest proposal
Authors: Grainger Jonathan , Hannagan Thomas
Published: August 2012

Frost proposes a new agenda for reading research, whereby cross-linguistic experiments would uncover linguistic universals to be integrated within a universal theory of reading. We reveal the dangers of following such a call, and demonstrate the superiority of the very approach that Frost condemns.
Consideration of the linguistic characteristics of letters makes the universal model of reading more universal
Authors: Kim Kyungil , Lee Chang H. , Lee Yoonhyoung
Published: August 2012

We suggest that the linguistic characteristics of letters also need to be considered to fully understand how a reader processes printed words. For example, studies in Korean showed that unambiguity in the assignment of letters to their appropriate onset, vowel, or coda slot is one of the main sources of the letter-transposition effect. Indeed, the cognitive system that processes Korean is tuned to the structure of the Korean writing system.
What and where is the word?
Authors: McBride-Chang Catherine , Chen Hsuan-Chih , Kasisopa Benjawan , Burnham Denis , Reilly Ronan , Leppänen Paavo
Published: August 2012

Examples from Chinese, Thai, and Finnish illustrate why researchers cannot always be confident about the precise nature of the word unit. Understanding ambiguities regarding where a word begins and ends, and how to model word recognition when many derivations of a word are possible, is essential for universal theories of reading applied to both developing and expert readers.
Flashing out or fleshing out? A developmental perspective on a universal model of reading
Authors: Homer Bruce D. , Miller Russell , Donnelly Seamus
Published: August 2012

The principles for universal reading models proposed by Frost correspond to developmental theories, in which neurocognitive constraints and cultural experiences shape development. We question his contention that Hebrew word identification is fundamentally about roots, excluding verbal and nominal word-pattern morphemes; and we propose that readers use all information available in stimuli, adjusting for volume and usefulness.
The limitations of the reverse-engineering approach to cognitive modeling
Authors: Rueckl Jay G.
Published: August 2012

Frost's critique reveals the limitations of the reverse-engineering approach to cognitive modeling – the style of psychological explanation in which a stipulated internal organization (in the form of a computational mechanism) explains a relatively narrow set of phenomena. An alternative is to view organization as both the explanation for some phenomena and a phenomenon to be explained. This move poses new and interesting theoretical challenges for theories of word reading.
Frost and fogs, or sunny skies? Orthography, reading, and misplaced optimalism
Authors: Share David L.
Published: August 2012

I argue that the study of variability rather than invariance should head the reading research agenda, and that strong claims of orthographic “optimality” are unwarranted. I also expand briefly on Frost's assertion that an efficient orthography must represent sound and meaning, by considering writing systems as dual-purpose devices that must provide decipherability for novice readers and automatizability for the expert.
A universal approach to modeling visual word recognition and reading: Not only possible, but also inevitable
Authors: Frost Ram
Published: August 2012

I have argued that orthographic processing cannot be understood and modeled without considering the manner in which orthographic structure represents phonological, semantic, and morphological information in a given writing system. A reading theory, therefore, must be a theory of the interaction of the reader with his/her linguistic environment. This outlines a novel approach to studying and modeling visual word recognition, an approach that focuses on the common cognitive principles involved in processing printed words across different writing systems. These claims were challenged by several commentaries that contested the merits of my general theoretical agenda, the relevance of the evolution of writing systems, and the plausibility of finding commonalities in reading across orthographies. Other commentaries extended the scope of the debate by bringing into the discussion additional perspectives. My response addresses all these issues. By considering the constraints of neurobiology on modeling reading, developmental data, and a large scope of cross-linguistic evidence, I argue that front-end implementations of orthographic processing that do not stem from a comprehensive theory of the complex information conveyed by writing systems do not present a viable approach for understanding reading. The common principles by which writing systems have evolved to represent orthographic, phonological, and semantic information in a language reveal the critical distributional characteristics of orthographic structure that govern reading behavior. Models of reading should thus be learning models, primarily constrained by cross-linguistic developmental evidence that describes how the statistical properties of writing systems shape the characteristics of orthographic processing. When this approach is adopted, a universal model of reading is possible.