bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of β2‐α2 loop mutation on amyloidogenic properties of the prion protein
Authors: Dutta Arpana , Chen Shugui , Surewicz Witold K.
Published: July 2013

Recent studies revealed that elk‐like S170N/N174T mutation in mouse prion protein (moPrP), which results in an increased rigidity of β2‐α2 loop, leads to a prion disease in transgenic mice. Here we characterized the effect of this mutation on biophysical properties of moPrP. Despite similar thermodynamic stabilities of wild type and mutant proteins, the latter was found to have markedly higher propensity to form amyloid fibrils. Importantly, this effect was observed even under fully denaturing conditions, indicating that the increased conversion propensity of the mutant protein is not due to loop rigidity but rather results from greater amyloidogenic potential of the amino acid sequence within the loop region of S170N/N174T moPrP.
The role of the N‐terminal tail for the oligomerization, folding and stability of human frataxin
Authors: Faraj Santiago E. , Venturutti Leandro , Roman Ernesto A. , Marino-Buslje Cristina B. , Mignone Astor , Tosatto Silvio C.E. , Delfino José M. , Santos Javier
Published: July 2013

The N‐terminal stretch of human frataxin (hFXN) intermediate (residues 42–80) is not conserved throughout evolution and, under defined experimental conditions, behaves as a random‐coil. Overexpression of hFXN56–210 in Escherichia coli yields a multimer, whereas the mature form of hFXN (hFXN81–210) is monomeric. Thus, cumulative experimental evidence points to the N‐terminal moiety as an essential element for the assembly of a high molecular weight oligomer. The secondary structure propensity of peptide 56–81, the moiety putatively responsible for promoting protein–protein interactions, was also studied. Depending on the environment (TFE or SDS), this peptide adopts α‐helical or β‐strand structure. In this context, we explored the conformation and stability of hFXN56–210. The biophysical characterization by fluorescence, CD and SEC‐FPLC shows that subunits are well folded, sharing similar stability to hFXN90–210. However, controlled proteolysis indicates that the N‐terminal stretch is labile in the context of the multimer, whereas the FXN domain (residues 81–210) remains strongly resistant. In addition, guanidine hydrochloride at low concentration disrupts intermolecular interactions, shifting the ensemble toward the monomeric form. The conformational plasticity of the N‐terminal tail might impart on hFXN the ability to act as a recognition signal as well as an oligomerization trigger. Understanding the fine‐tuning of these activities and their resulting balance will bear direct relevance for ultimately comprehending hFXN function.
The Prevalence of Alcohol Prevention Efforts in Swedish Workplaces
Authors: Källmén Håkan , Leifman Håkan , Hermansson Ulric , Vinberg Stig
Published: July 2013

This article presents results from a survey aimed at identifying the extent of alcohol prevention efforts in Swedish workplaces focusing on the dissemination of a model for secondary prevention — the ‘Risk Drinking model’. From a random sample of 929 human resource managers at Swedish workplaces, 374 answered a web-based questionnaire (response rate = 40%). Results showed that about 70% had an alcohol policy at their workplace, 51% were engaged in alcohol prevention efforts and about 19% used the Risk Drinking model. Regression analyses showed that large workplaces, workplaces where employees received training on alcohol, public sector and female-dominated workplaces were significantly associated with alcohol prevention activities. We conclude that training is important for the implementation of alcohol prevention at Swedish workplaces, and is of particular importance in small enterprises.
High frequency oscillatory flows in a slightly rarefied gas according to the Boltzmann–BGK equation
Authors: Nassios Jason , Sader John E.
Published: July 2013

The Boltzmann equation provides a rigorous theoretical framework to study dilute gas flows at arbitrary degrees of rarefaction. Asymptotic methods have been applied to steady flows, enabling the development of analytical formulae. For unsteady (oscillatory) flows, two important limits have been studied: (i) at low oscillation frequency and small mean free path, slip models have been derived; and (ii) at high oscillation frequency and large mean free path, the leading-order dynamics are free-molecular. In this article, the complementary case of small mean free path and high oscillation frequency is examined in detail. All walls are solid and of arbitrary smooth shape. We perform a matched asymptotic expansion of the unsteady linearized Boltzmann–BGK equation in the small parameter $\nu / \omega $, where $\nu $ is the collision frequency of gas particles and $\omega $ is the characteristic oscillation frequency of the flow. Critically, an algebraic expression is derived for the perturbed mass distribution function throughout the bulk of the gas away from any walls, at all orders in the frequency ratio $\nu / \omega $. This is supplemented by a boundary layer correction defined by a set of first-order differential equations. This system is solved explicitly and in complete generality. We thus provide analytical expressions up to first order in the frequency ratio, for the density, temperature, mean velocity and stress tensor of the gas, in terms of the temperature and mean velocity of the wall, and the applied body force. In stark contrast to other asymptotic regimes, these explicit formulae eliminate the need to solve a differential equation for a body of arbitrary geometry. To illustrate the utility of these results, we study the oscillatory thermal creep problem for which we find a tangential boundary layer flow arises at first order in the frequency ratio.
Innovations in US Banking Practices and the Credit Boom of the 1920s
Authors: Rötheli Tobias
Published: July 2013

The 1920s were important for the development of banking in the United States because new lending practices strongly favored credit expansion. Those innovations pertained to the measurement of credit risk and to new sales methods for banks. In particular, I describe the development of scientific credit analysis and so-called credit barometrics. Credit barometrics indicated credit worthiness based on statistical analysis and replaced old rules of thumb. These indicators were flawed and induced an erroneous belief in a future with rational and safe credit management. By studying the course of major New York banks as well as aggregate data, I show how the innovations in banking methods contributed to the credit boom that ended with the crash in 1929.
Récits idéologiques et logique démocratique : pour une réévaluation de l'idéologie à partir de Claude Lefort et Paul Ricoeur
Authors: Dutrisac Myrtô
Published: July 2013

Résumé.Mon objectif est de mettre de l'avant une dimension souvent négligée du discours idéologique, dimension positive qui en fait un type de récit politique permettant à un groupe de se nommer et de se définir. Je cherche plus précisément à compléter l'analyse de l'idéologie proposée par Claude Lefort en m'appuyant sur les observations qu'offre Paul Ricoeur sur ce phénomène. Lefort, lecteur de Marx, semble mettre essentiellement de l'avant la dimension dissimulatrice de l'idéologie. Pourtant, il aurait selon moi tout à gagner à reconnaître sa dimension positive, dimension jouant un rôle essentiel dans la construction de l'imaginaire social collectif. Mon hypothèse est la suivante : il ne faut pas négliger cet apport positif du discours idéologique, reconnu par Ricoeur, puisque ce discours, aussi longtemps qu'il reste bien visible, est un moteur essentiel du jeu démocratique. Même quand l'idéologie s'expose comme pur discours de domination, servant à défendre les intérêts d'une classe dominante, elle nourrit la compétition ou la logique démocratique en s'offrant comme un discours d'autorité auquel on peut réagir. L'étude du mouvement du discours idéologique, mouvement entre affirmation et dissimulation, permettrait même d'offrir de nouvelles perspectives de réponse au problème de la crise de l'imaginaire social qui occupe Lefort à l'époque où il publie ses textes sur l'idéologie, à la fin des années soixante-dix.

Abstract.Ideology is often perceived as an instrument used by a group of people to secure its domination over others. It is used to disguise certain aspects of social reality. I want to bring forward another dimension of ideology, a positive dimension that makes it a necessary component of the affirmation, and therefore the births, of social groups. To do this, I wish to supplement French philosopher Claude Lefort's analysis of ideology with the addition of a few ideas inspired by the work of one of his peers, Paul Ricoeur. Lefort, a reader of Marx, focuses essentially on the dissimulative dimension of this phenomenon. By doing so, he does not take into consideration its role in the construction of social imaginaries. I wish to argue that this positive aspect of ideology, acknowledged by Ricoeur, plays an essential role in the democratic experience, as long as the ideological discourse remains visible for everyone. Even when this discourse presents itself solely as an instrument of domination used by a class in order to preserve its own interests, it sustains the internal logic of democracy. By establishing itself as the main discourse of authority, its legitimacy will undoubtedly be put into question in the course of the democratic competition for power. It nourishes this competition. I feel that the study of this movement of ideology between affirmation and dissimulation can even offer new solutions to the crisis of the social imaginary diagnosed by Lefort during the 1970s, when he wrote his essays on ideology.
Pontobdella muricata infection of Raja clavata and Dasyatis pastinaca off the coast of Lesvos, Greece
Authors: Bakopoulos Vasileios , Ksidia Vasiliki-Chrysa
Published: July 2013

An investigation of ectoparasites of skates caught off the coast of Lesvos Island, north-eastern Aegean, Greece was performed from May 2010 to February 2012. One parasite, identified as the marine leech Pontobdella muricata, was found on the skin of 0.43% of Raja clavata and 3.6% of Dasyatis pastinaca specimens examined during the investigation period. This is the first record of D. pastinaca as being a host to P. muricata. Macroscopic and microscopic observation of the lesions caused by the parasitism, revealed haemorrhages and swelling of the skin of R. clavata, a milder inflammation of the skin of D. pastinaca, congestion, necrosis and liquefaction of the skin at the site of leech attachment and a lesion with disappearance of upper skin layers after the detachment of the leech.
Evidence-based management to regulate the impact of tourism at a key marine turtle rookery on Zakynthos Island, Greece
Authors: Katselidis Kostas A. , Schofield Gail , Stamou Giorgos , Dimopoulos Panayotis , Pantis John D.
Published: July 2013

This study evaluates how key beach features influence suitability for nesting by Endangered loggerhead marine turtles Caretta caretta at an internationally important rookery on Zakynthos Island, Greece. During 2007–2009 we assimilated information on beach structure (elevation above sea level and width), the distribution of all nesting (turtle tracks that resulted in nests) and non-nesting (turtle tracks that did not result in nests) turtle emergences from the sea along 6 km of beach, nest placement parameters (distance from sea and elevation above sea level), and beach use by visitors. We found that turtles preferentially emerged on steeper sections of beach, with higher nesting densities occurring on the most environmentally stable beaches. Elevation was a more reliable indicator of nest placement (1 m above sea level) than distance to shore. However, because nests on steeper slopes are located closer to shore, the risk of damage by tourism is increased in such areas. We calculated a potential 36% overlap of natural nest locations with use of the beach by tourists; however, the recorded overlap was 7% because of existing management protocols. This overlap could be further reduced by focusing conservation effort (i.e. further restricting use by people) on beach sections with the steepest inclines. For example, slopes of > 22° comprise 1 km of total beach area annually, the closure of which (above the immediate shoreline to allow passage) would completely protect 50% of nests. This study shows the value of evidence-based management as a practical scientific tool to conserve threatened species in dynamic protected areas that are of both environmental and economic importance.
Structures of colonialism in Itō Sei's “Yūki no machi”
Authors: Dodd Stephen
Published: July 2013

In Itō Sei's (1905–69) “Yūki no machi” (Streets of ghosts, 1937), a narrator returns to his native town of Otaru, Hokkaido, where he experiences a hellish and hallucinatory encounter with people from his past. He is forced to confront shameful aspects of his youthful life that he had tried to repress. In this paper, I propose that a close examination of the story sheds useful light on the real fears, tensions and expectations surrounding colonialism that had become an integral part of Japanese culture and society during the late 1930s. Structures of colonialism, which speak of uneven power relationships between a dominant centre and a distant weaker locality, are spelt out, for example, through the railway network and racist ideology that appear in the story. I also explore the story's depiction of a colonial relationship between mainland Japanese culture centred round Tokyo and the peripheral outpost of Hokkaido. More generally, I suggest that the story illuminates a global power configuration between Japan and its colonies that was entering an increasingly aggressive and bellicose phase during the late 1930s.
Cunobelinus' Bronze Coinage
Authors: Morris Francis M.
Published: July 2013

Cunobelinus was the most significant figure in Britain during the decades leading up to the Roman invasion, though his reign has received relatively little attention. Cunobelinus' coinage is of great importance to understanding the socio-political structure of South-East Britain prior to the Roman invasion and whilst studies of his gold and silver have been published in previous editions ofBritannia(Allen 1975; de Jersey 2001), his bronzes have been subject to surprisingly little work, particularly considering that they are by far the most common struck bronze issues known from Iron Age Britain, with a total of 2,608 examples currently recorded in the Celtic Coin Index and on the PAS database combined. This study proposes a broad typological scheme with which Cunobelinus' bronzes can be ordered and demonstrates that, like Cunobelinus' silver, but unlike his gold, they can be divided into three regional groupings, which it can be argued correspond to three different political sub-groupings under Cunobelinus' control. In addition, the bronze's metallurgy and metrology and the mints at which they were struck are investigated. This article examines the contribution of coinage to understanding Cunobelinus' political history, and how he used imagery to reinforce and legitimate his power in the different regions under his control at different times during his reign. The types of sites at which Cunobelinus' bronzes have been found are also outlined and the likely function of the coins discussed.
Optical breakdown threshold in fused silica with femtosecond laser pulses
Authors: Bendib A. , Bendib-Kalache K. , Deutsch C.
Published: July 2013

A theoretical model for electrons in the conduction band intend to investigate the optical breakdown threshold in femtosecond laser pulse-fused silica interaction is presented. The model is derived from a rate equation that includes the avalanche and multi-photon ionization processes of Thornber and Keldysh, respectively, and also the three-body and exciton recombination mechanisms. In addition, the time evolution of electron mean energy is also considered through the energy balance equation. The mean energy acts as a trigger for the avalanche mechanism. The evolution of electron density profiles is calculated and discussed with respect to the ionization and recombination mechanisms. The results for the fluence threshold as a function of the pulse duration fall in good agreement with the experimental data reported in the literature.
Seeing the Light: Lysander Spooner's Increasingly Popular Constitutionalism
Authors: Knowles Helen J.
Published: July 2013

On Tuesday July 4, 1854, it was hot and humid at Harmony Grove; “the heat of the weather…was extreme.” But this did not deter a large audience from gathering at this location in Framingham, Massachusetts. This was the spot upon which many of them had assembled, under the organization of the Massachusetts Anti-Slavery Society, for the past 8 years. They came by crowded railroad cars (from Boston, Milford, and Worcester), and by horse and carriage from many other surrounding towns, eager to hear speeches by prominent members of the antislavery community. William Lloyd Garrison was not the first to speak, but his actions were the most memorable. Addressing the audience, Garrison held up, and systematically burned, three documents: a copy of the 1850 Fugitive Slave Act; a copy of a recent court decision that ordered the free state of Massachusetts to use its facilities to assist in the capture of fugitive slaves; and a copy of the United States Constitution. This was no mere symbolic act; it conveyed an important part of the Garrisonian argument. Namely, that the Constitution was “a covenant with death, and an agreement with hell.”
A case for multiple views of function in design based on a common definition
Authors: Chakrabarti Amaresh , Srinivasan V. , Ranjan B.S.C. , Lindemann Udo
Published: July 2013

Functions are important in designing. However, several issues hinder progress with the understanding and usage of functions: lack of a clear and overarching definition of function, lack of overall justifications for the inevitability of the multiple views of function, and scarcity of systematic attempts to relate these views with one another. To help resolve these, the objectives of this research are to propose a common definition of function that underlies the multiple views in literature and to identify and validate the views of function that are logically justified to be present in designing. Function is defined as a change intended by designers between two scenarios: before and after the introduction of the design. A framework is proposed that comprises the above definition of function and an empirically validated model of designing, extended generate, evaluate, modify, and select of state-change, and an action, part, phenomenon, input, organ, and effect model of causality (Known as GEMS of SAPPhIRE), comprising the views of activity, outcome, requirement–solution–information, and system–environment. The framework is used to identify the logically possible views of function in the context of designing and is validated by comparing these with the views of function in the literature. Describing the different views of function using the proposed framework should enable comparisons and determine relationships among the various views, leading to better understanding and usage of functions in designing.
Making function modeling practically usable
Authors: Tomiyama Tetsuo , van Beek Thom J. , Alvarez Cabrera Andrés Alberto , Komoto Hitoshi , D'Amelio Valentina
Published: July 2013

Function modeling is considered potentially useful in various fields of engineering, including engineering design. However, a close look at practices reveals that practitioners do not use formal function modeling so much, while the concept of “function” frequently appears in many practical methods without a vigorous definition. This paper tries to understand why formal function modeling is not practically utilized in industry by analyzing usage cases of function. By observing product development activities in industry, the paper identifies three problems that prevent formal function modeling from wider applications in practices, namely, practitioners' neglect of function modeling, the lack of practically useful function reasoning, and the complexity of the methods and tools of formal function modeling that make them impractical. Finally, the paper proposes strategies to tackle these problems and illustrates some research efforts in this regard.
D'al-Khwārizmī à Descartes
Authors: Sasaki Chikara
Published: July 2013

The volume D'al-Khwārizmī à Descartes is a monumental contribution to the world history of mathematical sciences, showing clearly that Arabic mathematics was an indispensable predecessor of early modern European mathematics. Roshdi Rashed is known, first of all, as an editor of classical mathematical writings in Arabic by such authors as al-Khwārizmī, Thābit ibn Qurra, Ibrāhīm ibn Sinān, Ibn al-Haytham, al-Khayyām, Sharaf al-Dīn al-Ṭūsī, as well as of the Arabic versions of Apollonius' Conics, Diophantus' Arithmetica, and Diocles' Burning Mirrors. As the volume under review shows, he is also a historian of mathematics of the first class who has transformed historiography. This book is, in a sense, a manifesto of Prof. Rashed's entire œuvre.
A Theology of Everything
Authors: Coyne S.J. George V.
Published: July 2013

The rise of natural theology in the seventeenth century did not originate in theology, but in science. It was not started by theologians trying from above to impress a religious perspective on science. On the contrary, the natural theology of the century of the Enlightenment began as a grass-roots movement among believing scientists who were convinced both that God's existence could be proved and some of His attributes described from below, that is, on the basis of the expanding world of scientific knowledge. Essentially they were arguing for the existence of a Deity whose direct intervention would explain the gaps in the scientific discourse. But this manner of reasoning made natural theology extremely vulnerable. It would clearly lose its power at the moment when the scientific discourse itself became sufficiently advanced to close the gaps by its own force.
From Evidence to Understanding: A Precarious Path
Authors: Hand David J.
Published: July 2013

Falsifiability is the cornerstone of science. However, Rutherford notwithstanding, almost by definition science functions at the limits of measurement accuracy and theoretical grasp, so that statistical analysis is central to scientific advance. This applies as much to physics as it does to psychology, as much to geology as to biology. I look at some of the potholes in the path of scientific discovery, showing how easy it is to stumble, and at some of the consequences for the scientific endeavour.
Climate Change Sceptics
Authors: Legras Bernard
Published: July 2013

By predicting a global change of the Earth's climate, scientists are delivering an uncomfortable message. The release of the fourth IPCC report in 2007 has led to a surge of scepticism and criticism of both the science and the scientists. All this has received a lot of press coverage. Here I discuss the roots of climate change scepticism and how it has been triggered by the complex and novel aspects of climate science. I also call for more transparent and open practice in science, as more light is precisely what its opponents cannot afford.
DIRECTED TECHNOLOGICAL CHANGE: A KNOWLEDGE-BASED MODEL
Authors: Li Tailong , Pan Shiyuan , Zou Heng-fu
Published: July 2013

In a knowledge-based growth model where skilled workers are used in innovation and production, skill-biased technological change may lower average R&D productivity via an innovation possibilities frontier effect that eliminates scale effects. We show that skill-biased technological change increases the skill premium even if the elasticity of substitution between skilled and unskilled workers is less than two. Trade between developed countries promotes skill-biased technological change, thus raising wage inequality. Trade between developed and developing countries has differing effects: it induces relatively skill-replacing technological change and lowers wage inequality in the developed country but has the opposite effects in the developing country. Finally, we show that trade can stimulate or hurt economic growth.
A Fast Nonlinear Regression Method for Estimating Permeability in CT Perfusion Imaging
Authors: Bennink Edwin , Riordan Alan J , Horsch Alexander D , Dankbaar Jan Willem , Velthuis Birgitta K , de Jong Hugo W
Published: July 2013

Blood–brain barrier damage, which can be quantified by measuring vascular permeability, is a potential predictor for hemorrhagic transformation in acute ischemic stroke. Permeability is commonly estimated by applying Patlak analysis to computed tomography (CT) perfusion data, but this method lacks precision. Applying more elaborate kinetic models by means of nonlinear regression (NLR) may improve precision, but is more time consuming and therefore less appropriate in an acute stroke setting. We propose a simplified NLR method that may be faster and still precise enough for clinical use. The aim of this study is to evaluate the reliability of in total 12 variations of Patlak analysis and NLR methods, including the simplified NLR method. Confidence intervals for the permeability estimates were evaluated using simulated CT attenuation-time curves with realistic noise, and clinical data from 20 patients. Although fixating the blood volume improved Patlak analysis, the NLR methods yielded significantly more reliable estimates, but took up to 12 x longer to calculate. The simplified NLR method was ~4 x faster than other NLR methods, while maintaining the same confidence intervals (CIs). In conclusion, the simplified NLR method is a new, reliable way to estimate permeability in stroke, fast enough for clinical application in an acute stroke setting.
Rate and Phonological Variation in Preschool Children: Effects of Modeling and Directed Influence
Authors: Torrington Eaton Catherine , Bernstein Ratner Nan
Published: July 2013

Purpose

To explore the effect of modeling and explicit elicitation of slow and accurately produced speech in typically developing preschool children. Optional phonological reductions (e.g., deleted final stops) and changes in speech rate were examined in response to an adult conversational speaker's speech style.

Method

Forty 3- and 4-year-olds (20 each) were tested in 3 tasks: (a) immediate repetition of a model, (b) spontaneous speech, and (c) directed speech style (cueing to correct “sloppy” speech). In Task 1, half of each group heard fast and hypoarticulated versus slow and hyperarticulated speech for a between-group response-to-model comparison. Tasks 2 and 3 were compared within subjects.

Results

Task 1 demonstrated that both age groups aligned with the speaker's rate and phonological variants usage when repeating a model. Tasks 2 and 3 revealed that 4-year-olds varied phonological reduction patterns according to the task demands, whereas 3-year-olds maintained consistent patterns of usage. In addition, neither group successfully realigned with the rapid speech rate in Task 3.

Conclusions

These results contribute to an evidence base supporting the practice of modeling slow and clear speech to children with various production disorders. Further research is needed to explore the cognitive–linguistic processes underlying alignment before findings are applied to clinical populations.

Supplemental Material

https://doi.org/10.23641/asha.14963580
Systematic Assessment and Instruction of Assistive Technology for Cognition (ATC) Following Brain Injury: An Introduction
Authors: Powell Laurie Ehlhardt , Glang Ann , Ettel Deborah
Published: July 2013

This article provides a summary of crucial issues related to implementation of Assistive Technology for Cognition (ATC) following brain injury. Components of assessment, instruction, and outcome measurement are highlighted, clinically-applicable checklists are provided, pertinent research is described, and practical considerations are addressed.
Assistive Technology for Cognition Following Brain Injury: A Clinician's Perspective
Authors: Daly Mary Pat
Published: July 2013

Whether working in a specialized brain injury program, outpatient clinic, acute care hospital, or private practice, speech-language pathologists serving adults with cognitive impairments due to acquired brain injury (ABI) are faced with many challenges: assessment, treatment planning, client and family education, documentation, team conferences, and billing. The combination of these demands requires a high level of efficiency. Include the rapidly expanding field of assistive technology for cognition (ATC) — cell phones, smart phones, tablets, and apps used to compensate for cognitive impairments — and the most experienced and adept clinician can feel overwhelmed. This article describes the practical application of ATC assessment and training in the brain injury day treatment program at the Brain Injury Rehabilitation Center (BIRC), Portland, OR, across three domains: (a) a clinician’s perceptions of ATC and its integration into clinical practice, (b) selected ATC assessment processes and training techniques, and (c) challenges associated with the implementation of ATC in a clinical setting.
Speech-Related Breathing in Infants: How Much Do We Really Know?
Authors: Parham Douglas F.
Published: July 2013

A rich area of research is the question of how infants learn to use the respiratory system to produce increasingly complex utterances during the first 2 years of life. Understanding infant speech-related breathing is foundational to properly describing human speech development. This article serves as a brief introduction to research on speech-related breathing in infancy. The goal of this summary article is to provide a springboard—and an invitation—for researchers interested in pursuing the respiratory aspects of early speech development.
Perioperative Voice Recovery: A Wound-Healing Perspective
Authors: Branski Ryan C.
Published: July 2013

To describe the wound healing process through an oversimplified graphic, a classic cartoon in a Dermatology Clinics textbook shows a Volkswagen Beetle, with the license plate TRAUMA that has driven through a wooden fence, leaving both a substantive hole in the fence and piles of broken wooden planks. The obvious priority would be to rebuild the fence so that it is identical to its pretrauma state. This analogy and accompanying graphic provide a framework for a unique perspective on wound healing. For the sake of simplicity, let us assume that the vocal fold is a fence, and instead of a Volkswagen Beetle, the trauma is surgical excision of a vocal fold lesion. Immediately following surgery, the human body initiates the process of rebuilding vocal fold tissue. From a physiological perspective, it would be ideal to regain the original architecture of the vocal fold to ensure minimal alteration to phonatory physiology. Unfortunately, beyond the 2nd trimester of gestation, wounds heal with subsequent scarring. In the vocal folds, this scarring can have significant deleterious effects on vocal fold pliability and lead to dysphonia. However, investigators have shown that wounds heal regeneratively (i.e., no scarring) in the fetal environment. This observation provides potential targets for therapies to direct wound healing toward a more favorable outcome. In this article, I provide a brief overview of the biochemical processes associated with wound healing. Subsequently, I outline the underlying rationale for tissue mobilization in the context of acute vocal fold injury.
Ferroelectric mechanism of croconic acid: A first-principles and Monte Carlo study
Authors: Cai Yaxuan , Luo Shijun , Zhu Zhanwu , Gu Haoshuang
Published: July 2013

The ferroelectric mechanism of croconic acid in terms of the electronic structure and the molecular structure was studied by first principles using the density functional theory with the generalized gradient approximation. The spontaneous polarization (Ps) was simulated by the Berry phase method. It is found that the large polarization originates from charge transfer due to the strong “push-pull” effect of electron-releasing and -withdrawing groups along the hydrogen bond. According to the characteristics of polarization of croconic acid, we constructed a one-dimensional ferroelectric Hamiltonian model to describe the ferroelectric properties of croconic acid. Based on the Hamiltonian model, the thermal properties of the ferroelectricity of croconic acid were studied by Monte Carlo method. The simulated Curie temperature is 756 K, and the spontaneous polarization keeps well temperature range stability up to 400 K. These results are in good agreement with the experimental data.
Numerical and experimental study of thermal explosions in LX-10 and PBX 9501: Influence of thermal damage on deflagration processes
Authors: Tringe J. W. , Kercher J. R. , Springer H. K. , Glascoe E. A. , Levie H. W. , Hsu P. , Willey T. M. , Molitoris J. D.
Published: July 2013

We employ in-situ flash x-ray imaging, together with a detailed multiphase convective burn model, to demonstrate how explosives' binder characteristics influence the burning processes in thermal explosions. Our study focuses on the HMX-based explosives LX-10 and PBX 9501. While the HMX (cyclotetramethylene-tetranitramine) crystallite size distributions for these two explosives are nearly identical before heating, our experiments and simulations indicate that after heating, variations result due to differences in binder composition. Post-ignition flash x-ray images reveal that the average density decreases at late times more rapidly in PBX 9501 than LX-10, suggesting a faster conductive burning rate in PBX-9501. Heated permeability measurements in LX-10 and PBX 9501 demonstrate that the binder system characteristics influence the evolution of connected porosity. Once ignited, connected porosity provides pathways for product gas heating ahead of the reaction front and additional surface area for burning, facilitating the transition from conductive to convective burning modes. A multiphase convective burn model implemented in the ALE3D code is used to better understand the influence on burn rates of material properties such as porosity and effective thermally damaged particle size. In this context, particles are defined as gas-impermeable binder-coated crystallites and agglomerations with a set of effective radii reff. Model results demonstrate quantitative agreement with containment wall velocity for confined PBX 9501 and LX-10, and qualitative agreement with density as a function of position in the burning explosive. The model predicts a decrease in post-ignition containment wall velocity with larger radii in reff. These experimental data and model results together provide insight into the initiation and propagation of the reaction wave that defines the convective burn front in HMX-based explosives, a necessary step toward predicting violence under a broad range of conditions.
Comparison of edge turbulence imaging at two different poloidal locations in the scrape-off layer of Alcator C-Mod
Authors: Zweben S. J. , Terry J. L. , Agostini M. , Davis W. M. , Diallo A. , Ellis R. A. , Golfinopoulos T. , Grulke O. , Hughes J. W. , LaBombard B. , Landreman M. , Myra J. R. , Pace D. C. , Stotler D. P.
Published: July 2013

This paper describes 2D imaging measurements of plasma turbulence made in the scrape-off layer of the Alcator C-Mod tokamak simultaneously at two different poloidal locations, one near the outer midplane and the other near the divertor X-point region. These images were made with radial and poloidal resolution using two gas puff imaging diagnostics not directly connected along a B field line. The turbulence correlation structure has a significantly different tilt angle with respect to the local flux surfaces for the midplane and X-regions, and a slightly different ellipticity and size. The time-averaged turbulence velocities can be different in the midplane and X-regions, even within the same flux surface in the same shot. The structures are partially consistent with a magnetic flux tube mapping model, and the velocities are compared with various models for turbulence flow.
Adaptive single replica multiple state transition interface sampling
Authors: Du Wei-Na , Bolhuis Peter G.
Published: July 2013

The multiple state transition path sampling method allows sampling of rare transitions between many metastable states, but has the drawback that switching between qualitatively different pathways is difficult. Combination with replica exchange transition interface sampling can in principle alleviate this problem, but requires a large number of simultaneous replicas. Here we remove these drawbacks by introducing a single replica sampling algorithm that samples only one interface at a time, while efficiently walking through the entire path space using a Wang-Landau approach or, alternatively, a fixed bias. We illustrate the method on several model systems: a particle diffusing in a simple 2D potential, isomerization in a small Lennard Jones cluster, and isomerization of the alanine dipeptide in explicit water.
Generalized coupling parameter expansion: Application to square well and Lennard-Jones fluids
Authors: Ramana A. Sai Venkata
Published: July 2013

The coupling parameter expansion in thermodynamic perturbation theory of simple fluids is generalized to include the derivatives of bridge function with respect to coupling parameter. We applied seventh order version of the theory to Square-Well (SW) and Lennard-Jones (LJ) fluids using Sarkisov Bridge function. In both cases, the theory reproduced the radial distribution functions obtained from integral equation theory (IET) and simulations with good accuracy. Also, the method worked inside the liquid-vapor coexistence region where the IETs are known to fail. In the case of SW fluids, the use of Carnahan-Starling expression for Helmholtz free energy density of Hard-Sphere reference system has improved the liquid-vapor phase diagram (LVPD) over that obtained from IET with the same bridge function. The derivatives of the bridge function are seen to have significant effect on the liquid part of the LVPD. For extremely narrow SW fluids, we found that the third order theory is more accurate than the higher order versions. However, considering the convergence of the perturbation series, we concluded that the accuracy of the third order version is a spurious result. We also obtained the surface tension for SW fluids of various ranges. Results of present theory and simulations are in good agreement. In the case of LJ fluids, the equation of state obtained from the present method matched with that obtained from IET with negligible deviation. We also obtained LVPD of LJ fluid from virial and energy routes and found that there is slight inconsistency between the two routes. The applications lead to the following conclusions. In cases where reference system properties are known accurately, the present method gives results which are very much improved over those obtained from the IET with the same bridge function. In cases where reference system data is not available, the method serves as an alternative way of solving the Ornstein-Zernike equation with a given closure relation with the advantage that solution can be obtained throughout the phase diagram with a proper choice of the reference system.
Dynamic coupling of magnetic resonance modes in pairs of mesoscopic rectangles
Authors: Swoboda Christian , Kuhlmann Nils , Martens Michael , Vogel Andreas , Meier Guido
Published: July 2013

We investigate the magnetization dynamics in pairs of mesoscopic permalloy (Ni80Fe20) rectangles by means of broadband-ferromagnetic resonance measurements and micromagnetic simulations. Each pair consists of two rectangles that differ in their geometry. The local effective field at each element is significantly affected by the stray field of its neighbor for small center-to-center distances between the rectangles. In antiparallel magnetization alignment, this dynamic dipolar coupling becomes prominent and anticrossing between ferromagnetic resonance modes and higher-order spin-wave modes is observed. Combination of the experimental and the simulational findings provides a comprehensive understanding of dynamically coupled rectangles.
Lower estimates of the growth order of solutions to the second Painlevé hierarchy
Authors: Sasaki Yoshikatsu
Published: July 2013

This article concerns with the second Painlevé hierarchy, i.e., the 2nth order analogues of the second Painlevé equation. Though several higher order analogues of the second Painlevé equation are proposed by several authors, we investigate one derived from the KdV hierarchy by similarity reduction, and give the lower estimate of the growth order of transcendental meromorphic solutions to the second Painlevé hierarchy with an integer parameter. Moreover, the first lemma in Appendix supplements an incompleteness of Li and He [“On analytic properties of higher analogs of the second Painlevé equation,” J. Math. Phys. 43, 1106–1115 (2002)]10.1063/1.1420396 and Li [“Some properties of the solutions of higher analogue of the Painlevé equation,” Acta Math. Appl. Sin. 22, 59–64 (2006)]10.1007/s10255-005-0285-0.
Lévy flights and nonlocal quantum dynamics
Authors: Garbaczewski Piotr , Stephanovich Vladimir
Published: July 2013

We develop a fully fledged theory of quantum dynamical patterns of behavior that are nonlocally induced. To this end we generalize the standard Laplacian-based framework of the Schrödinger picture quantum evolution to that employing nonlocal (pseudodifferential) operators. Special attention is paid to the Salpeter (here, m ⩾ 0) quasirelativistic equation and the evolution of various wave packets, in particular to their radial expansion in 3D. Foldy's synthesis of “covariant particle equations” is extended to encompass free Maxwell theory, which however is devoid of any “particle” content. Links with the photon wave mechanics are explored.
Basis set expansion for inverse problems in plasma diagnostic analysis
Authors: Jones B. , Ruiz C. L.
Published: July 2013

A basis set expansion method [V. Dribinski, A. Ossadtchi, V. A. Mandelshtam, and H. Reisler, Rev. Sci. Instrum. 73, 2634 (2002)]10.1063/1.1482156 is applied to recover physical information about plasma radiation sources from instrument data, which has been forward transformed due to the nature of the measurement technique. This method provides a general approach for inverse problems, and we discuss two specific examples relevant to diagnosing fast z pinches on the 20–25 MA Z machine [M. E. Savage, L. F. Bennett, D. E. Bliss, W. T. Clark, R. S. Coats, J. M. Elizondo, K. R. LeChien, H. C. Harjes, J. M. Lehr, J. E. Maenchen, D. H. McDaniel, M. F. Pasik, T. D. Pointon, A. C. Owen, D. B. Seidel, D. L. Smith, B. S. Stoltzfus, K. W. Struve, W. A. Stygar, L. K. Warne, J. R. Woodworth, C. W. Mendel, K. R. Prestwich, R. W. Shoup, D. L. Johnson, J. P. Corley, K. C. Hodge, T. C. Wagoner, and P. E. Wakeland, in Proceedings of the Pulsed Power Plasma Sciences Conference (IEEE, 2007), p. 979]. First, Abel inversion of time-gated, self-emission x-ray images from a wire array implosion is studied. Second, we present an approach for unfolding neutron time-of-flight measurements from a deuterium gas puff z pinch to recover information about emission time history and energy distribution. Through these examples, we discuss how noise in the measured data limits the practical resolution of the inversion, and how the method handles discontinuities in the source function and artifacts in the projected image. We add to the method a propagation of errors calculation for estimating uncertainties in the inverted solution.
Parameter spaces for linear and nonlinear whistler-mode waves
Authors: Summers Danny , Tang Rongxin , Omura Yoshiharu , Lee Dong-Hun
Published: July 2013

We examine the growth of magnetospheric whistler-mode waves which comprises a linear growth phase followed by a nonlinear growth phase. We construct time-profiles for the wave amplitude that smoothly match at the transition between linear and nonlinear wave growth. This matching procedure can only take place over a limited “matching region” in (Nh/N0,AT)-space, where AT is the electron thermal anisotropy, Nh is the hot (energetic) electron number density, and N0 is the cold (background) electron number density. We construct this matching region and determine how the matching wave amplitude varies throughout the region. Further, we specify a boundary in (Nh/N0,AT)-space that separates a region where only linear chorus wave growth can occur from the region in which fully nonlinear chorus growth is possible. We expect that this boundary should prove of practical use in performing computationally expensive full-scale particle simulations, and in interpreting experimental wave data.
Plastic flows and phase transformations in materials under compression in diamond anvil cell: Effect of contact sliding
Authors: Feng Biao , Levitas Valery I. , Zarechnyy Oleg M.
Published: July 2013

Modeling of coupled plastic flows and strain-induced phase transformations (PTs) under high pressure in a diamond anvil cell is performed with the focus on the effect of the contact sliding between sample and anvils. Finite element software abaqus is utilized and a combination of Coulomb friction and plastic friction is considered. Results are obtained for PTs to weaker, equal-strength, and stronger high pressure phases, using different scaling parameters in a strain-controlled kinetic equation, and with various friction coefficients. Compared to the model with cohesion, artificial shear banding near the constant surface is eliminated. Sliding and the reduction in friction coefficient intensify radial plastic flow in the entire sample (excluding a narrow region near the contact surface) and a reduction in thickness. A reduction in the friction coefficient to 0.1 intensifies sliding and increases pressure in the central region. Increases in both plastic strain and pressure lead to intensification of strain-induced PT. The effect of self-locking of sliding is revealed. Multiple experimental phenomena are reproduced and interpreted. Thus, plastic flow and PT can be controlled by controlling friction.
A novel Gaussian Binning (1GB) analysis of vibrational state distributions in highly excited ${\rm H}_\text{2}$H2O from reactive quenching of OH* by ${\rm H}_\text{2}$H2
Authors: Conte Riccardo , Fu Bina , Kamarchik Eugene , Bowman Joel M.
Published: July 2013

As shown in experiments by Lester and co-workers [J. Chem. Phys. 110, 11117 (1999)]10.1063/1.479053, the reactive quenching of OH* by \documentclass[12pt]{minimal}\begin{document}${\rm H}_\text{2}$\end{document}H2 produces highly excited \documentclass[12pt]{minimal}\begin{document}${\rm H}_\text{2}$\end{document}H2O. Previous limited analysis of quasiclassical trajectory calculations using standard Histogram Binning (HB) was reported [B. Fu, E. Kamarchik, and J. M. Bowman, J. Chem. Phys. 133, 164306 (2010)]10.1063/1.3488167. Here, we examine the quantized internal state distributions of \documentclass[12pt]{minimal}\begin{document}${\rm H}_\text{2}$\end{document}H2O in more detail, using two versions of Gaussian Binning (denoted 1GB). In addition to the standard version of 1GB, which relies on the harmonic energies of the states (1GB-H), we propose a new and more accurate technique based on exact quantum vibrational energies (1GB-EQ). Data from about 42 000 trajectories from previous calculations that give excited water molecules are used in the two versions of 1GB as well as HB. For the vibrationally hot molecules considered in this study, the classical internal energy distribution serves as a benchmark to estimate the accuracy of the different binning methods analyzed. The 1GB discretization methods, especially the one using exact quantum energies, reconstruct the classical distribution much more accurately than HB and also the original, more elaborate Gaussian Binning method. Detailed quantum state distributions are presented for pure overtone excitations as well as several antisymmetric stretch distributions. The latter are focused on because the antisymmetric stretch has the largest emission oscillator strength of the three water modes.