bluuebunny/crossref_metadata_2025 huggingface dataset:
The tandem β‐zipper: Modular binding of tandem domains and linear motifs
Authors: Matthews Jacqueline M. , Potts Jennifer R.
Published: January 2013

The tandem β‐zipper protein–protein binding interface involves an intrinsically disordered protein (IDP) binding two or more globular domains through β‐sheet‐augmentation in a modular fashion, and represents a paradigm in IDP‐mediated protein–protein interactions. While characterised tandem β‐zippers are rare, known examples are associated with diverse biological processes. A combination of their advantages (binding specificity and the ability to generate high affinity binding sites by linking multiple lower affinity motifs) and the prevalence of both tandem domains and IDPs points to the existence of many more β‐zippers in nature. The characterisation of these interactions has greatly enhanced the understanding of the biological systems involved but given their apparent tolerance to mutation, detecting other tandem β‐zipper interactions using bioinformatics may be challenging.
Knowledge and use of and opportunities for emergency contraception in Northern Haiti
Authors: Lathrop Eva , Telemaque Youseline , Haddad Lisa , Stephenson Rob , Goedken Peggy , Cwiak Carrie , Jamieson Denise J.
Published: January 2013

Objective

To evaluate the knowledge and experience of, and desire for, emergency contraception (EC) in postpartum women in Haiti, and to determine the knowledge and practices of EC providers.

Methods

As part of a larger postpartum family planning study, 6 focus groups were conducted with postpartum women (n = 33), 3 were conducted with providers (n = 22), and a questionnaire was given to postpartum women (n = 250).

Results

Of the 249 women who completed the survey, 145 (58.2%) were aware of the concept of EC as an emergency measure in the postcoital period. Of these, 130 (89.7%) had knowledge of traditional methods only. Twenty‐eight (11.2%) women had used some form of EC in the past, but only 2 (0.8%) reported ever using a modern form of EC. Providers reported that EC was offered to women only in cases of sexual assault. Their impression was that there was no demand for EC.

Conclusion

Awareness and use of EC is low in the context of high unmet need. The results demonstrate a need for improved education and provision of modern effective EC as part of the constellation of family planning choices.
The influence of task‐ and location‐specific complexity on the control and coordination costs in global outsourcing relationships
Authors: Handley Sean M. , Benton W.C.
Published: January 2013

Several reputable industry sources have recognized that many organizations fail to realize the financial benefits sought with outsourcing. Further, prior research has found that outsourcing organizations struggle to estimate accurately the so called “hidden costs” associated with managing these inter‐organizational relationships. This is especially true of complex, globally distributed outsourced services. In this study, we use dyadic data on 102 outsourcing relationships to investigate how dimensions of task‐ and location‐specific complexity influence the degree of control and coordination costs incurred by the customer organization. Results from our hierarchical regression analysis demonstrate that the scale of the service and the geographic distance between the customer and provider locations are associated with higher levels of both control and coordination costs. Task breadth and geographic dispersion are significantly associated with increased control costs, but not coordination costs. Counter to our expectations, control costs decrease with the degree of service customization, whereas both control and coordination costs are negatively related to the average cultural distance between provider and customer organizations. These findings contribute unique empirical evidence to the outsourcing, offshoring, and international service operations literature.
Enhanced HDL‐cholesterol‐associated anti‐oxidant PON‐1 activity in prostate cancer patients
Authors: Eroglu Muzaffer , Yilmaz Necat , Yalcinkaya Soner , Ay Nurullah , Aydin Ozgur , Sezer Cem
Published: January 2013

Increases in the generation of reactive oxygen species and decreases in antioxidant enzyme activities with aging have been reported in the prostate, and are also observed in age‐related disorders such as atherosclerosis, Alzheimer's disease, and cataracts. Several studies have demonstrated that proteins are targets for reactive oxidants in cells, and that oxidized proteins accumulate during aging, oxidative stress and in some pathological conditions. However, only a limited number of studies have actually evaluated oxidative damage in relation to HDL‐cholesterol‐associated antioxidant enzyme activities or have assessed its relationship with prostate cancer. In this study, we examined the effect of HDL‐cholesterol‐associated antioxidant enzyme activities, paraoxonase1, arylesterase and new oxidative stress parameters (total oxidant status, total antioxidant status [and oxidative stress index]) in newly‐diagnosed prostate cancer patients and healthy controls. There were no significant differences in oxidative stress parameters and lipid parameters between prostate cancer patients and controls, however, paraoxonase1 enzyme activity, and non‐HDL‐cholesterol levels were higher in prostate cancer patients than controls. The results of this study were derived from a small number of subjects, but might represent an important working hypothesis for further research in a larger number of cases to clarify the role of paraoxonase1 overproduction on the prostate and its clinical relevance.
VGLL3 expression is associated with a tumor suppressor phenotype in epithelial ovarian cancer
Authors: Gambaro Karen , Quinn Michael C.J. , Wojnarowicz Paulina M. , Arcand Suzanna L. , de Ladurantaye Manon , Barrès Véronique , Ripeau Jean-Sébastien , Killary Ann M. , Davis Elaine C. , Lavoie Josée , Provencher Diane M. , Mes-Masson Anne-Marie , Chevrette Mario , Tonin Patricia N.
Published: January 2013

Previous studies have implicated vestigial like 3 (VGLL3), a chromosome 3p12.3 gene that encodes a putative transcription co‐factor, as a candidate tumor suppressor gene (TSG) in high‐grade serous ovarian carcinomas (HGSC), the most common type of epithelial ovarian cancer. A complementation analysis based on microcell‐mediated chromosome transfer (MMCT) using a centric fragment of chromosome 3 (der3p12‐q12.1) into the OV‐90 ovarian cancer cell line haploinsufficient for 3p and lacking VGLL3 expression was performed to assess the effect on tumorigenic potential and growth characteristics. Genetic characterization of the derived MMCT hybrids revealed that only the hybrid that contained an intact VGLL3 locus exhibited alterations of tumorigenic potential in a nude mouse xenograft model and various in vitro growth characteristics. Only stable OV‐90 transfectant clones expressing low levels of VGLL3 were derived. These clones exhibited an altered cytoplasmic morphology characterized by numerous single membrane bound multivesicular‐bodies (MVB) that were not attributed to autophagy. Overexpression of VGLL3 in OV‐90 was achieved using a lentivirus‐based tetracycline inducible gene expression system, which also resulted in MVB formation in the infected cell population. Though there was no significant differences in various in vitro and in vivo growth characteristics in a comparison of VGLL3‐expressing clones with empty vector transfectant controls, loss of VGLL3 expression was observed in tumors derived from mouse xenograft models. VGLL3 gene and protein expression was significantly reduced in HGSC samples (>98%, p < 0.05) relative to either normal ovarian surface epithelial cells or epithelial cells of the fallopian tube, possible tissues of origin of HGSC. Also, there appeared to be to be more cases with higher staining levels in stromal tissue component from HGSC cases that had a prolonged disease‐free survival. The results taken together suggest that VGLL3 is involved in tumor suppressor pathways, a feature that is characterized by the absence of VGLL3 expression in HGSC samples.
Islamic and conventional banks' soundness during the 2007–2008 financial crisis
Authors: Bourkhis Khawla , Nabi Mahmoud Sami
Published: January 2013

The recent global financial crisis has induced a series of failure of many conventional banks and led to an increased interest in the Islamic banking business model. This paper attempts to answer empirically the following question: What was the effect of the 2007–2008 financial crisis on the soundness of Islamic banks and their conventional peers? Using the Z‐score as an indicator of bank stability, our regression analysis (covering a matched sample of 34 Islamic Banks (IBs) and 34 conventional banks (CBs) from 16 countries) shows that there is no significant difference in terms of the effect of the financial crisis on the soundness of IBs and CBs. This finding reveals that IBs are diverging from their theoretical business model which would have allowed them to keep the same level of soundness even during the crisis.
Nuclear Superiority and the Balance of Resolve: Explaining Nuclear Crisis Outcomes
Authors: Kroenig Matthew
Published: January 2013

Scholars have long debated whether nuclear superiority or the balance of resolve shapes the probability of victory in nuclear crises, but they have not clearly articulated a mechanism linking superiority to victory, nor have they systematically analyzed the entire universe of empirical cases. Beginning from a nuclear brinkmanship theory framework, I develop a new theory of nuclear crisis outcomes, which links nuclear superiority to victory in nuclear crises precisely through its effect on the balance of resolve. Using a new data set on fifty-two nuclear crisis dyads, I show that states that enjoy nuclear superiority over their opponents are more likely to win nuclear crises. I also find some support for the idea that political stakes shape crisis outcomes. These findings hold even after controlling for conventional military capabilities and for selection into nuclear crises. This article presents a new theoretical explanation, and the first comprehensive empirical examination, of nuclear crisis outcomes.
Unthinkable and Tragic: The Psychology of Weapons Taboos in War
Authors: Dolan Thomas M.
Published: January 2013

Discussions of weapons taboos have failed to take into account the possibility that prescriptive international and national norms of behavior may come into conflict. Using psychological studies of trade-offs and protected values as a guide, this article argues that when these conflicts exist, the taboos' individual-level constraining effects can be vitiated. An analysis of General George Marshall's proposal to use chemical weapons against the Japanese in 1945 demonstrates that normative conflict can produce a readiness to violate weapons taboos. In these situations, state decisions to violate taboos may depend on the extent to which the perception of normative conflict is shared by other decision makers and society more generally.
The Logic of Child Soldiering and Coercion
Authors: Beber Bernd , Blattman Christopher
Published: January 2013

Why do armed groups recruit large numbers of children as fighters, often coercively? The international community has tried to curb these crimes by shaming and punishing leaders who commit them—in short, making the crimes costlier. Are these policies effective and sufficient? The answer lies in more attention to the strategic interaction between rebel leaders and recruits. We adapt theories of industrial organization to rebellious groups and show how, being less able fighters, children are attractive recruits if and only if they are easier to intimidate, indoctrinate, and misinform than adults. This ease of manipulation interacts with the costliness of war crimes to influence rebel leaders' incentives to coerce children into war. We use a case study and a novel survey of former child recruits in Uganda to illustrate this argument and provide hard evidence not only that children are more easily manipulated in war, but also how—something often asserted but never demonstrated. Our theory, as well as a new “cross-rebel” data set, also support the idea that costliness matters: foreign governments, international organizations, diasporas, and local populations can discourage child recruitment by withholding resources or punishing offenders (or, conversely, encourage these crimes by failing to act). But punishing war crimes has limitations, and can only take us so far. Children's reintegration opportunities must be at least as great as adults' (something that demobilization programs sometimes fail to do). Also, indoctrination and misinformation can be directly influenced. We observe grassroots innovations in Uganda that could be models for the prevention and curbing of child soldiering and counterinsurgency generally.
A WARP-SPEED METHOD FOR CONDUCTING MONTE CARLO EXPERIMENTS INVOLVING BOOTSTRAP ESTIMATORS
Authors: Giacomini Raffaella , Politis Dimitris N. , White Halbert
Published: January 2013

We analyze fast procedures for conducting Monte Carlo experiments involving bootstrap estimators, providing formal results establishing the properties of these methods under general conditions.
MULTISTEP PREDICTION OF PANEL VECTOR AUTOREGRESSIVE PROCESSES
Authors: Greenaway-McGrevy Ryan
Published: January 2013

This paper considers the conventional recursive (otherwise known as plug-in) and direct multistep forecasts in a panel vector autoregressive framework. We derive asymptotic expressions for the mean square prediction error (MSPE) of both forecasts asN(cross sections) andT(time periods) grow large. Both the bias and variance of the least squares fitting are manifest in the MSPE. Using these expressions, we consider the effect of model specification on predictor accuracy. When the fitted lag order (q) is equal to or exceeds the true lag order (p), the direct MSPE is larger than the recursive MSPE. On the other hand, when the fitted lag order is underspecified, the direct MSPE is smaller than the recursive MSPE. The recursive MSPE is increasing inqfor allq≥p. In contrast, the direct MSPE is not monotonic inqwithin the permissible parameter space. Extensions to bias-corrected least squares estimators are considered.
INCONSISTENT VAR REGRESSION WITH COMMON EXPLOSIVE ROOTS
Authors: Phillips Peter C.B. , Magdalinos Tassos
Published: January 2013

Nielsen (Working paper, University of Oxford, 2009) shows that vector autoregression is inconsistent when there are common explosive roots with geometric multiplicity greater than unity. This paper discusses that result, provides a coexplosive system extension and an illustrative example that helps to explain the finding, gives a consistent instrumental variable procedure, and reports some simulations. Some exact limit distribution theory is derived and a useful new reverse martingale central limit theorem is proved.
A New Law—A New Perspective for Archaeological Heritage Preservation in the Republic of Moldova
Authors: Musteață Sergiu
Published: January 2013

Abstract: This article provides one of the first presentations of the Law of the Republic of Moldova on Archaeological Heritage Preservation recently approved by the Moldovan Parliament. Since 1993, Moldova has had a general law on monument preservation, but the part on archaeological heritage was poorly developed. The new law is the first of its kind in Moldova and was established according to the principles of the European and International Conventions signed in recent years by the Republic of Moldova. This law opens new avenues for Moldovan society to improve the situation in of its archaeological heritage, specifically to fight the black market in archaeology and illegal trafficking of antiquities.
Heritage Inc.: A Mini-Symposium on Heritage Protection and Private Actors. Held at the Faculty of Law, University of British Columbia, Vancouver, Canada, 16 March 2012
Authors: Paterson Robert K. , Telesetsky Anastasia
Published: January 2013

In response to the emerging phenomenon of the role of nonstate actors in heritage protection and preservation, a one-day symposium took place on 16 March 2012 in the new Allard Hall building of the Faculty of Law at the University of British Columbia in Vancouver, Canada. The conference was officially opened by Dean of Law, Professor Mary Anne Bobinski and received financial support from the University of British Columbia, Faculty of Law Conference Fund; the Pacific Northwest Canadian Studies Consortium; and Golder Associates Ltd. The conference brought together seven experts from both academia and practice to discuss contemporary practices and emerging legal and sociological trends in heritage protection by private actors.
1 January 2011–31 December 2011
Authors: Siehr Kurt
Published: January 2013

In Russia a new statute entered into force according to which all confiscated objects of the Orthodox Church should be given back to the former owner. Die Zeit, 3 February 2011, p. 58.
The serotype case-case design: a direct comparison of a novel methodology with a case-control study in a nationalSalmonellaEnteritidis PT14b outbreak in England and Wales
Authors: ZENNER D. , JANMOHAMED K. , LANE C. , LITTLE C. , CHARLETT A. , ADAK G. K. , MORGAN D.
Published: January 2013

Societal and technological changes render traditional study designs less feasible for investigation of outbreaks. We compared results obtained from case-case and case-control designs during the investigation of aSalmonellaEnteritidis PT14b (SE14b) outbreak in Britain to provide support for validation of this approach. Exposures of cases were compared to concurrent non-EnteritidisSalmonellacases and population controls recruited through systematic digit phone dialling. Infection with SE14b was associated with eating in oriental restaurants [odds ratio (OR) 35·8, 95% confidence interval (CI) 4·4–290·9] and consuming eggs away from home (OR 13·8, 95% CI 1·5–124·5) in the case-case study and was confirmed through a concurrent case-control study with similar effect estimates and microbiological findings of SE14b in eggs from a specific chicken flock on a Spanish farm. We found that the case-case design was feasible, quick and inexpensive, potentially minimized recall bias and made use of already interviewed cases with subtyping results. This approach has potential for use in future investigations.
Bioterrorism and the Fermi Paradox
Authors: Cooper Joshua
Published: January 2013

We proffer a contemporary solution to the so-called Fermi Paradox, which is concerned with conflict between Copernicanism and the apparent paucity of evidence for intelligent alien civilizations. In particular, we argue that every community of organisms that reaches its space-faring age will (1) almost immediately use its rocket-building computers to reverse-engineer its genetic chemistry and (2) self-destruct when some individual uses said technology to design an omnicidal pathogen. We discuss some of the possible approaches to prevention with regard to Homo sapiens’ vulnerability to bioterrorism, particularly on a short-term basis.
Ethnolinguistic Identity and Television Use in a Minority Language Setting
Authors: Harwood Jake , Vincze Laszlo
Published: January 2013

Based on the model of Reid, Giles and Abrams (2004 , Zeitschrift für Medienpsychologie, 16, 17–25), this paper describes and analyzes the relation between television use and ethnolinguistic-coping strategies among German speakers in South Tyrol, Italy. The data were collected among secondary school students (N = 415) in 2011. The results indicated that the television use of the students was dominated by the German language. A mediation analysis revealed that TV viewing contributed to the perception of ethnolinguistic vitality, the permeability of intergroup boundaries, and status stability, which in turn affected ethnolinguistic-coping strategies of mobility (moving toward the outgroup), creativity (maintaining identity without confrontation), and competition (fighting for ingroup rights and respect). Findings and theoretical implications are discussed.
Killing Is Positive!
Authors: Lang Annie , Bradley Samuel D. , Schneider Edward F. , Kim Sojung C. , Mayell Sharon
Published: January 2013

This paper reports a study designed to investigate whether playing violent video games elicits the psychological conditions theoretically required for media use to cause aggressive behavior. Specifically, the study was designed to examine whether these games elicit desensitization, facilitation, and disinhibition. Thus, does physiological arousal in response to violent activity decrease over time during game play, and is there a difference between novice and experienced game players (as would be expected if desensitization had occurred)? Do players experience positive emotional states when actively engaged in virtual violent behavior (fighting and killing opponents) – a necessary condition for disinhibition? Do game players frame their motivations in terms of self-defense and game success, as would be necessary for facilitation to occur? The results showed that playing first-person shooters did elicit these requisite patterns of cognitive, physiological, and emotional states. Violent game play is a positive, arousing, present, dominant experience, as required for disinhibition and facilitation. Experienced game players are less aroused than less experienced game players (as required for desensitization). Further, during a game-playing session, exploring and searching for enemies become less arousing, while fighting and killing become more arousing over time (as required by desensitization and facilitation).
EPR characterization of diamagnetic and magnetic organic soft materials using nitroxide spin probe techniques
Authors: Tamura Rui , Suzuki Katsuaki , Uchida Yoshiaki , Noda Yohei
Published: January 2013

This review article summarizes the recent advances in the EPR studies of the molecular orientation and magnetic properties in the various rod-like liquid crystalline (LC) phases of the second-generation of organic nitroxide radical materials in the bulk state or in a surface-stabilized LC cell, compared with the conventional EPR studies using classical organic nitroxide spin probes. Noteworthy is the first observation and characterization of a sort of spin glass-like ferromagnetic interactions (J > 0) induced by weak magnetic fields in the various LC phases of the second-generation of organic nitroxide radical materials. This unique magnetic property has been referred to as positive “magneto-LC effects”. The utility of such novel LC nitroxide radical materials as the EPR spin probes is also presented.
YB-1: oncoprotein, prognostic marker and therapeutic target?
Authors: Lasham Annette , Print Cristin G. , Woolley Adele G. , Dunn Sandra E. , Braithwaite Antony W.
Published: January 2013

Hanahan and Weinberg have proposed the ‘hallmarks of cancer’ to cover the biological changes required for the development and persistence of tumours [Hanahan and Weinberg (2011) Cell 144, 646–674]. We have noted that many of these cancer hallmarks are facilitated by the multifunctional protein YB-1 (Y-box-binding protein 1). In the present review we evaluate the literature and show how YB-1 modulates/regulates cellular signalling pathways within each of these hallmarks. For example, we describe how YB-1 regulates multiple proliferation pathways, overrides cell-cycle check points, promotes replicative immortality and genomic instability, may regulate angiogenesis, has a role in invasion and metastasis, and promotes inflammation. We also argue that there is strong and sufficient evidence to suggest that YB-1 is an excellent molecular marker of cancer progression that could be used in the clinic, and that YB-1 could be a useful target for cancer therapy.
Pediatric Orbital Fractures
Authors: Oppenheimer Adam J. , Monson Laura A. , Buchman Steven R.
Published: January 2013

It is wise to recall the dictum “children are not small adults” when managing pediatric orbital fractures. In a child, the craniofacial skeleton undergoes significant changes in size, shape, and proportion as it grows into maturity. Accordingly, the craniomaxillofacial surgeon must select an appropriate treatment strategy that considers both the nature of the injury and the child's stage of growth. The following review will discuss the management of pediatric orbital fractures, with an emphasis on clinically oriented anatomy and development.
Exploring the accessible frequency range of phase-resolved ferromagnetic resonance detected with x-rays
Authors: Warnicke P. , Knut R. , Wahlström E. , Karis O. , Bailey W. E. , Arena D. A.
Published: January 2013

We present time- and element-resolved measurements of the magnetization dynamics in a ferromagnetic trilayer structure. A pump-probe scheme was utilized with a microwave magnetic excitation field phase-locked to the photon bunches and x-ray magnetic circular dichroism in transmission geometry. Using a relatively large photon bunch length with a full width at half maximum of 650 ps, the precessional motion of the magnetization was resolved up to frequencies of 2.5 GHz, thereby enabling sampling at frequencies significantly above the inverse bunch length. By simulating the experimental data with a numerical model based on a forced harmonic oscillator, we obtain good correlation between the two. The model, which includes timing jitter analysis, is used to predict the accessible frequency range of x-ray detected ferromagnetic resonance.
Modeling of plasma chemistry in an atmospheric pressure Ar/NH3 cylindrical dielectric barrier discharge described using the one-dimensional fluid model
Authors: Li Zhi , Zhao Zhen , Li Xuehui
Published: January 2013

The keynote of our research is to study the gas phase chemistry in an atmospheric pressure Ar/NH3 cylindrical dielectric barrier discharge, which is very important to produce the iron-nitride magnetic fluid. For this purpose, a home-made one dimensional fluid model with the Scharfetter-Gummel method has been developed. The equations solved are the particle balances, assuming a drift-diffusion approximation for the fluxes, and the electron energy equation. The self-consistent electric field is obtained by the simultaneous solution of Poisson's equation. The simulations were carried out for the different ammonia concentrations (2%, 3.5%, and 7%), at a voltage of 1 kV, and a driving frequency of 20 kHz. It concluded that the major ion products of Ar are Ar+ and Ar2+. Ar+ is the most important positive ions, followed by Ar2+. It is shown that the NH+ density is smaller than that of the other ammonia ions. The density of NH4+ is more than that of the other ammonia ions when the ammonia concentration increased. The diffuse mode can be established after the discharge was ignited, and the mode changes to filamentary mode with an increase in ammonia concentration.
Optimal scale-free network with a minimum scaling of transport efficiency for random walks with a perfect trap
Authors: Yang Yihang , Zhang Zhongzhi
Published: January 2013

Average trapping time (ATT) is central in the trapping problem since it is a key indicator characterizing the efficiency of the problem. Previous research has provided the scaling of a lower bound of the ATT for random walks in general networks with a deep trap. However, it is still not well understood in which networks this minimal scaling can be reached. Particularly, explicit quantitative results for ATT in such networks, even in a specific network, are lacking, in spite that such networks shed light on the design for optimal networks with the highest trapping efficiency. In this paper, we study the trapping problem taking place on a hierarchical scale-free network with a perfect trap. We focus on four representative cases with the immobile trap located at the root, a peripheral node, a neighbor of the root with a single connectivity, and a farthest node from the root, respectively. For all the four cases, we obtain the closed-form formulas for the ATT, as well as its leading scalings. We show that for all the four cases of trapping problems, the dominating scalings of ATT can reach the predicted minimum scalings. This work deepens the understanding of behavior of trapping in scale-free networks, and is helpful for designing networks with the most efficient transport process.
Three-dimensional shape invariant non-separable model with equidistant spectrum
Authors: Bardavelidze M. S. , Cannata F. , Ioffe M. V. , Nishnianidze D. N.
Published: January 2013

A class of three-dimensional models, which satisfy supersymmetric intertwining relations with the simplest—oscillator-like—variant of shape invariance, is constructed. It is proved that the models are not amenable to the conventional separation of variables for the complex potentials, but their spectra are real and equidistant (such as, for isotropic harmonic oscillator). The special case of such potential with quadratic interaction is solved completely. The Hamiltonian of the system is non-diagonalizable, and its wave functions and associated functions are built analytically. The symmetry properties of the model and degeneracy of energy levels are studied.
Fusion rules of equivariantizations of fusion categories
Authors: Burciu Sebastian , Natale Sonia
Published: January 2013

We determine the fusion rules of the equivariantization of a fusion category \documentclass[12pt]{minimal}\begin{document}${\mathcal {C}}$\end{document}C under the action of a finite group G in terms of the fusion rules of \documentclass[12pt]{minimal}\begin{document}${\mathcal {C}}$\end{document}C and group-theoretical data associated to the group action. As an application we obtain a formula for the fusion rules in an equivariantization of a pointed fusion category in terms of group-theoretical data. This entails a description of the fusion rules in any braided group-theoretical fusion category.
Antibody-independent isolation of circulating tumor cells by continuous-flow dielectrophoresis
Authors: Shim Sangjo , Stemke-Hale Katherine , Tsimberidou Apostolia M. , Noshari Jamileh , Anderson Thomas E. , Gascoyne Peter R. C.
Published: January 2013

Circulating tumor cells (CTCs) are prognostic markers for the recurrence of cancer and may carry molecular information relevant to cancer diagnosis. Dielectrophoresis (DEP) has been proposed as a molecular marker-independent approach for isolating CTCs from blood and has been shown to be broadly applicable to different types of cancers. However, existing batch-mode microfluidic DEP methods have been unable to process 10 ml clinical blood specimens rapidly enough. To achieve the required processing rates of 106 nucleated cells/min, we describe a continuous flow microfluidic processing chamber into which the peripheral blood mononuclear cell fraction of a clinical specimen is slowly injected, deionized by diffusion, and then subjected to a balance of DEP, sedimentation and hydrodynamic lift forces. These forces cause tumor cells to be transported close to the floor of the chamber, while blood cells are carried about three cell diameters above them. The tumor cells are isolated by skimming them from the bottom of the chamber while the blood cells flow to waste. The principles, design, and modeling of the continuous-flow system are presented. To illustrate operation of the technology, we demonstrate the isolation of circulating colon tumor cells from clinical specimens and verify the tumor origin of these cells by molecular analysis.
Theory of liquid crystalline micelles
Authors: Matsuyama Akihiko
Published: January 2013

A theory is introduced to describe self-assembly of liquid crystalline AB diblock copolymers, consisting of a homopolymer (A) and a side-chain liquid crystalline polymer (B). We derive the free energy of the liquid crystalline micellar solutions and examine the equilibrium solution properties: critical micelle concentration (CMC), nematic-isotropic phase transition (NIT) of the rigid side-chains inside the micelle core, and phase separations. It is shown that there is a critical micelle size below which the NIT becomes continuous due to a packing effect. We also find re-entrant micellizations near the NIT temperature. The phase diagrams, including binodal, spinodal, CMC, and NIT curves are also examined on the temperature-concentration plane.
Incorporation of beams into bossed diaphragm for a high sensitivity and overload micro pressure sensor
Authors: Yu Zhongliang , Zhao Yulong , Sun Lu , Tian Bian , Jiang Zhuangde
Published: January 2013

The paper presents a piezoresistive absolute micro pressure sensor, which is of great benefits for altitude location. In this investigation, the design, fabrication, and test of the sensor are involved. By analyzing the stress distribution of sensitive elements using finite element method, a novel structure through the introduction of sensitive beams into traditional bossed diaphragm is built up. The proposed configuration presents its advantages in terms of high sensitivity and high overload resistance compared with the conventional bossed diaphragm and flat diaphragm structures. Curve fittings of surface stress and deflection based on ANSYS simulation results are performed to establish the equations about the sensor. Nonlinear optimization by MATLAB is carried out to determine the structure dimensions. The output signals in both static and dynamic environments are evaluated. Silicon bulk micromachining technology is utilized to fabricate the sensor prototype, and the fabrication process is discussed. Experimental results demonstrate the sensor features a high sensitivity of 11.098 μV/V/Pa in the operating range of 500 Pa at room temperature, and a high overload resistance of 200 times overpressure to promise its survival under atmosphere. Due to the excellent performance above, the sensor can be applied in measuring the absolute micro pressure lower than 500 Pa.
Formation and development of dislocation in graphene
Authors: Lee Gun-Do , Yoon Euijoon , Hwang Nong-Moon , Wang Cai-Zhuang , Ho Kai-Ming
Published: January 2013

The formation and development processes of dislocation in graphene are investigated by performing tight-binding molecular dynamics (TBMD) simulation and ab initio total energy calculation. It is found that the coalescence of pentagon-heptagon (5-7) pairs with vacancy defects induces the formation of dislocation due to the separation of two 5-7 pairs. In TBMD simulations, adatoms are ejected and evaporated from graphene surface so that the dislocation is developed. It is observed that diffusing carbon atoms nearby dangling bonds help non-hexagonal rings change into stable hexagonal rings. These results might give some ideas for the control of structural properties by inducing defect structures.
Relaxor behavior of ferroelectric Ca0.22Sr0.12Ba0.66Nb2O6
Authors: Shekhar Pandey Chandra , Schreuer Jürgen , Burianek Manfred , Mühlberg Manfred
Published: January 2013

The relaxor behavior of tetragonal tungsten bronze uniaxial relaxor ferroelectric calcium strontium barium niobate (Ca0.22Sr0.12Ba0.66Nb2O6 or CSBN-22) single crystal was studied by measuring elastic constants and thermal expansion with the aid of resonant ultrasound spectroscopy and dilatometry, respectively, in the temperature range 300 K–1503 K. Thermal expansion yields evidence of the Burns temperature TB and the intermediate characteristic temperature T*, which was also supported by the temperature evolutions of the elastic constants cij. CSBN-22 was found to be ∼2%–3% elastically stiffer than CBN-28. The presented results open the perspective to understand the relaxor behavior of CSBN.
Electromigration induced fast L1 ordering phase transition in perpendicular FePt films
Authors: Feng Chun , Li Xujing , Yang Meiyin , Gong Kui , Zhu Yuanmin , Zhan Qian , Sun Li , Li Baohe , Jiang Yong , Yu Guanghua
Published: January 2013

Realizing fast L10 ordering phase transition (LOPT) in L10 structured magnetic materials without heat treatment is crucial for their applications in spintronic devices. This article reports on the electromigration controlled momentum transfer and rapid ordering of Fe and Pt atoms in the as-deposited FePt films. Lattice defects in the films provide enough diffusion pathways and allow the Fe and Pt atoms rearranging. Through the current driven atomic motion and rearrangement, fast LOPT can result in the establishment of perpendicular magnetic anisotropy of the FePt films at room temperature. This effect is expected to work with other L10 typed magnetic materials for spintronic devices development.
Observation of terahertz absorption signatures in microliter DNA solutions
Authors: Zhang W. , Brown E. R. , Rahman M. , Norton M. L.
Published: January 2013

Strong, repeatable Terahertz (THz) signatures are measured in small samples of DNA solution using a THz photomixing spectrometer with custom conical-horn coupling. The DNA specimen is linear, single-stranded (ss), 13-mer polynucleotide, and is diluted in buffer solution to have a concentration of 0.15 μmol/ml. The strongest signature is centered ∼717 GHz, and has a strength of 2.5 × 1016 cm−1/mol, linewidth 48 GHz, and damping time of 6.6 ps. The origin of the signature is attributed to the hydrogen bond of locally cross-linked ssDNAs.
Electron current extraction from radio frequency excited micro-dielectric barrier discharges
Authors: Wang Jun-Chieh , Leoni Napoleon , Birecki Henryk , Gila Omer , Kushner Mark J.
Published: January 2013

Micro dielectric barrier discharges (mDBDs) consist of micro-plasma devices (10–100 μm diameter) in which the electrodes are fully or partially covered by dielectrics, and often operate at atmospheric pressure driven with radio frequency (rf) waveforms. In certain applications, it may be desirable to extract electron current out of the mDBD plasma, which necessitates a third electrode. As a result, the physical structure of the m-DBD and the electron emitting properties of its materials are important to its operation. In this paper, results from a two-dimensional computer simulation of current extraction from mDBDs sustained in atmospheric pressure N2 will be discussed. The mDBDs are sandwich structures with an opening of tens-of-microns excited with rf voltage waveforms of up to 25 MHz. Following avalanche by electron impact ionization in the mDBD cavity, the plasma can be expelled from the cavity towards the extraction electrode during the part of the rf cycle when the extraction electrode appears anodic. The electron current extraction can be enhanced by biasing this electrode. The charge collection can be controlled by choice of rf frequency, rf driving voltage, and permittivity of the dielectric barrier.
Positron scattering from hydrogen atom embedded in weakly coupled plasma
Authors: Ghoshal Arijit , Kamali M. Z. M. , Ratnavelu K.
Published: January 2013

The positron-hydrogen collision problem in weakly coupled plasma environment has been investigated by applying a formulation of the three-body collision problem in the form of coupled multi-channel two-body Lippmann-Schwinger equations. The interactions among the charged particles in the plasma have been represented by Debye-Huckel potentials. A simple variational hydrogenic wave function has been employed to calculate the partial-wave scattering amplitude. Plasma screening effects on various possible mode of fragmentation of the system e++H(1s) during the collision, such as 1s→1s and 2s→2s elastic collisions, 1s→2s excitation, positronium formation, elastic proton-positronium collisions, have been reported. Furthermore, a detailed study has been made on differential and total cross sections of the above processes in the energy range 13.6-350 eV of the incident positron.
Tunable electronic properties of ZnO nanowires and nanotubes under a transverse electric field
Authors: Wang Yanzong , Wang Baolin , Zhang Qinfang , Shi Daning , Yunoki Seiji , Kong Fanjie , Xu Ning
Published: January 2013

Using the density functional theory, we investigate the electronic properties of ZnO nanowires (NWs) and faceted nanotubes (NTs) under a transverse electric field. We find that the band gap of ZnO nanostructures tends to decrease as the electric field is increased, and the variation of the band gap is dependent upon the diameter and wall thickness. Furthermore, the applied electric field could induce semiconductor-metal transition and enhance the electron effective mass. These results provide a valuable guide for the future application of ZnO nanostructures in the field of microelectronic and optoelectronic materials and nanodevices.
Suppression of drift wave turbulence and zonal flow formation by changing axial boundary conditions in a cylindrical magnetized plasma device
Authors: Chakraborty Thakur Saikat , Xu Min , Manz Peter , Fedorczak Nicolas , Holland Chris , Tynan George R.
Published: January 2013

For drift wave turbulence, due to charge conservation, the divergence of the parallel current is coupled to the divergence of the perpendicular polarization current, which determines the effective radial momentum flux, i.e., the Reynolds stress. Changes in the current flow patterns also affect the nonlinear energy transfer from smaller to larger scales. Here, we show that by changing the end plate boundary conditions in a cylindrical plasma device, the radial currents through the plasma and hence the net momentum transport and the nonlinear coupling for the inverse energy transfer are strongly modified. The transition to drift wave turbulence and the formation of low frequency zonal flows can be either suppressed with conducting boundaries or enhanced with insulating boundaries.
Photopolymerizable organically modified holographic glass with enhanced thickness for spectral filters
Authors: Velasco A. V. , Calvo M. L. , Cheben P.
Published: January 2013

A novel formulation and synthesis method to overcome the thickness limitations in samples of photopolymerizable glasses with high refractive index species is presented. The reported method allows the recording of volume holographic diffraction gratings in samples of ∼500 μm thickness with a high optical quality and low scattering. Holographic grating recording is performed in a single coherent light exposure step, resulting in volume gratings of high optical quality. A holographic notch filter implemented in a 500 μm thick photopolymerizable glass with a spectral bandwidth below 0.3 nm and an excellent filter extinction ratio of <−27 dB is also demonstrated.
Transversal magnetic anisotropy in nanoscale PdNi-strips
Authors: Steininger D. , Hüttel A. K. , Ziola M. , Kiessling M. , Sperl M. , Bayreuther G. , Strunk Ch.
Published: January 2013

We investigate submicron ferromagnetic PdNi thin-film strips intended as contact electrodes for carbon nanotube-based spintronic devices. The magnetic anisotropy and micromagnetic structure are measured as function of temperature. Contrary to the expectation from shape anisotropy, magnetic hysteresis measurements of Pd0.3Ni0.7 on arrays containing strips of various width point towards a magnetically easy axis in the sample plane, but transversal to the strip direction. Anisotropic magnetoresistance measured on individual Pd0.3Ni0.7 contact strips and magnetic force microscopy images substantiate that conclusion.
Transport behavior of holes in boron delta-doped diamond structures
Authors: Balmer Richard S. , Friel Ian , Hepplestone Steven , Isberg Jan , Uren Michael J. , Markham Matthew L. , Palmer Nicola L. , Pilkington James , Huggett Paul , Majdi Saman , Lang Richard
Published: January 2013

Boron delta-doped diamond structures have been synthesized using microwave plasma chemical vapor deposition and fabricated into FET and gated Hall bar devices for assessment of the electrical characteristics. A detailed study of variable temperature Hall, conductivity, and field-effect mobility measurements was completed. This was supported by Schrödinger-Poisson and relaxation time calculations based upon application of Fermi's golden rule. A two carrier-type model was developed with an activation energy of ∼0.2 eV between the delta layer lowest subband with mobility ∼1 cm2/Vs and the bulk valence band with high mobility. This new understanding of the transport of holes in such boron delta-doped structures has shown that although Hall mobility as high as 900 cm2/Vs was measured at room temperature, this dramatically overstates the actual useful performance of the device.
Note: Measurements of fast electrons in the TORE-SUPRA tokamak by means of modified Cherenkov-type diamond detector
Authors: Jakubowski L. , Sadowski M. J. , Zebrowski J. , Rabinski M. , Jakubowski M. J. , Malinowski K. , Mirowski R. , Lotte Ph. , Goniche M. , Gunn J. , Colledani G. , Pascal J.-Y. , Basiuk V.
Published: January 2013

The Note reports on experimental studies of ripple born fast electrons within the TORE-SUPRA facility, which were performed by means of a modified measuring head equipped with diamond detectors designed especially for recording the electron-induced Cherenkov radiation. There are presented signals produced by fast electrons in the TORE-SUPRA machine, which were recorded during two experimental campaigns performed in 2010. Shapes of these electron-induced signals are considerably different from those observed during the first measurements carried out by the prototype Cherenkov probe in 2008. An explanation of the observed differences is given.
Effect of filament supports on emissive probe measurements
Authors: Wang X. , Howes C. T. , Horányi M. , Robertson S.
Published: January 2013

We have constructed an emissive probe with a thin tungsten filament spot-welded across two nickel wires insulated with ceramic paint. We show that the ceramic supports covering the nickel wires have a large effect on the potential measurements in low-density plasmas. It is found that the potential measured by the emissive probe is more negative than the potential derived from a Langmuir probe current-voltage (I-V) characteristic curve when the plasma density is so low that the emitting filament remains immersed in the sheaths of the ceramic supports. The length of the filament L needs to be larger than about 2 Debye lengths (L > 2λDe) in order to avoid the influence of the ceramic supports and to achieve reliable plasma potential measurements using emissive probes.
Criteria of radio-frequency ring-shaped hollow cathode discharge using H2 and Ar gases for plasma processing
Authors: Ohtsu Yasunori , Kawasaki Yujiro
Published: January 2013

In order to achieve high-density capacitively coupled plasma, a radio-frequency (RF) ring-shaped hollow cathode discharge has been developed as a candidate for processing plasma sources. The plasma density in the hollow cathode discharge reaches a high magnitude of 1010–1011 cm−3. The RF ring-shaped hollow cathode discharge depends on the pressure and mass of the working gas. Criteria required for producing a RF ring-shaped hollow cathode discharge have been investigated for various gas pressures using H2 and Ar gases for high-density plasma production. The results reveal that the criteria for the occurrence of the hollow cathode effect are that the trench width should be approximately equal to the sum of the electron-neutral mean free paths and twice the sheath thickness of the RF powered electrode.
A digital miniature x-ray tube with a high-density triode carbon nanotube field emitter
Authors: Jeong Jin-Woo , Kang Jun-Tae , Choi Sungyoul , Kim Jae-Woo , Ahn Seungjoon , Song Yoon-Ho
Published: January 2013

We have fabricated a digital miniature x-ray tube (6 mm in diameter and 32 mm in length) with a high-density triode carbon nanotube (CNT) field emitter for special x-ray applications. The triode CNT emitter was densely formed within a diameter of below 4 mm with the focusing-functional gate. The brazing process enables us to obtain and maintain a desired vacuum level for the reliable electron emission from the CNT emitters after the vacuum packaging. The miniature x-ray tube exhibited a stable and reliable operation over 250 h in a pulse mode at an anode voltage of above 25 kV.