bluuebunny/crossref_metadata_2025 huggingface dataset:
Under-reporting of notifiable infectious disease hospitalizations: significant improvements in the Irish context
Authors: BRABAZON E. D. , SHERIDAN A. , FINNEGAN P. , CARTON M. W. , BEDFORD D.
Published: July 2014

Notification of infectious disease is essential for prompt public health action and epidemiological analysis. The aim of this study was to compare national hospitalization data to national notification data in order to assess if there was significant under-reporting of hospitalized notifiable infectious diseases in recent years in Ireland. All in-patient discharges from public hospitals in the Republic of Ireland from 2006 to 2011 with a principal diagnosis of a notifiable disease were compared with national notification data. It was found that only a potential 1·8% of extra notifications could have arisen due to these hospitalization events and would represent a tenfold reduction on a previous estimate of under-reporting in the Irish context. Viral meningitis, viral encephalitis, bacterial meningitis not otherwise specified and malaria were the most common diseases for which there were more hospitalizations than notifications reported. The results of this study support the conclusion that the reduction in under-reporting can mainly be accounted for by the introduction of laboratories as notifiers in conjunction with the roll out of the Computerized Infectious Disease Reporting system (CIDR). However, for the diseases highlighted, the notification data underestimates the true burden of disease and this has implications for understanding the epidemiology of these diseases.
Detection of methicillin-resistant Staphylococcus aureus carrying the mecC gene in human samples in Slovenia
Authors: DERMOTA U. , ZDOVC I. , STRUMBELJ I. , GRMEK-KOSNIK I. , RIBIC H. , RUPNIK M. , GOLOB M. , ZAJC U. , BES M. , LAURENT F. , MUELLER-PREMRU M.
Published: July 2014

Following the recognition of a mecC MRSA isolate from a patient hospitalized in the northeastern region of Slovenia, a national collection of 395 community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) isolates from 2006 to 2013 was screened. An additional six mecC MRSA strains were found and characterized as spa types t843, t9397 and t10009, and multilocus sequence type ST130. The low oxacillin minimum inhibitory concentrations and absence of the mecA gene make recognition of these MRSA strains problematical for diagnostic laboratories. In such strains the presence of mecC should be determined.
A Method to Test the Performance of an Energy-Dispersive X-Ray Spectrometer (EDS)
Authors: Hodoroaba Vasile-Dan , Procop Mathias
Published: July 2014

A test material for routine performance evaluation of energy-dispersive X-ray spectrometers (EDS) is presented. It consists of a synthetic, thick coating of C, Al, Mn, Cu, and Zr, in an elemental composition that provides interference-free characteristic X-ray lines of similar intensities at 10 kV scanning electron microscope voltage. The EDS energy resolution at the C-K, Mn-Lα, Cu-Lα, Al-K, Zr-Lα, and Mn-Kα lines, the calibration state of the energy scale, and the Mn-Lα/Mn-Kα intensity ratio as a measure for the low-energy detection efficiency are calculated by a dedicated software package from the 10 kV spectrum. Measurements at various input count rates and processor shaping times enable an estimation of the operation conditions for which the X-ray spectrum is not yet corrupted by pile-up events. Representative examples of EDS systems characterized with the test material and the related software are presented and discussed.
The AMINO experiment: methane photolysis under Solar VUV irradiation on the EXPOSE-R facility of the International Space Station
Authors: Carrasco Nathalie , Cottin Hervé , Cloix Mégane , Jérome Murielle , Bénilan Yves , Coll Patrice , Gazeau Marie-Claire , Raulin François , Saiagh Kafila , Chaput Didier , Szopa Cyril
Published: July 2014

The scientific aim of the present campaign is to study the whole chain of methane photo-degradation, as initiated by Solar vacuum-ultraviolet irradiation in Titan's atmosphere. For this purpose, the AMINO experiment on the EXPOSE-R mission has loaded closed cells for gas-phase photochemistry in space conditions. Two different gas mixtures have been exposed, named Titan 1 and Titan 2, involving both N2–CH4 gas mixtures, without and with CO2, respectively. CO2 is added as a source of reactive oxygen in the cells. The cell contents were analysed thanks to infrared absorption spectroscopy, gas chromatography and mass spectrometry. Methane consumption leads to the formation of saturated hydrocarbons, with no detectable influence of CO2. This successful campaign provides a first benchmark for characterizing the whole methane photochemical system in space conditions. A thin film of tholin-like compounds appears to form on the cell walls of the exposed cells.
The Spaces of Personalisation: Place and Distance in Caring Labour
Authors: Needham Catherine
Published: July 2014

The cluster of reforms to English social care associated with personalisation mark a break with recent thinking about what spaces are considered relevant and appropriate for people with an assessed social care need. The promise of personalisation from a spatial perspective appears to be twofold: expanding the physical spaces that are available to people, while at the same time contracting interpersonal spaces between people and those who support them to emphasise attentiveness and particularism. However, there is a danger that personalisation is much more variable in its impacts. The physical spaces for some are expanding while for others they contract, and these opportunities are likely to be unequally distributed in ways that overlay other forms of inequality. The attentiveness and particularism promised by personalisation is again patchily distributed, with wide variation in the quality of support planning and person-centred care. For the formal care workforce, the two concepts of space (physical environment and interpersonal closeness) intersect as physical spaces shape the capacity to deliver attentive, responsive care. The article brings these concepts together through a discussion of ‘caring labour’ at the intersection of the physical and emotional aspects of space.
STRUCTURAL PROPERTIES OF QUALITATIVE AND QUANTITATIVE ACCOUNTS TO COHERENCE
Authors: SCHIPPERS MICHAEL
Published: July 2014

This paper evaluates four different qualitative (probabilistic) accounts to coherence with a focus on structural properties (symmetries, asymmetries, and transitivity). It is shown that while coherence is not transitive on any of these accounts, there are screening-off conditions that render coherence transitive. In a second step, an array of quantitative (probabilistic) accounts to coherence is considered. The upshot is that extant measures differ considerably with respect to a number of symmetry constraints.
Pentecostalism as an Informal Political Institution: Experimental Evidence from Ghana
Authors: McCauley John F.
Published: July 2014

Informal institutions continue to govern political exchange in Africa, but the traditional, ethnic-based form of “big man rule” is now threatened by an alternative informal institution — charismatic Pentecostalism. This study evaluates the status of Pentecostalism empirically, in a micro-level experiment in Ghana. Using data from a variant of the dictator game, in which participants divide a resource endowment with randomly assigned partners as well as cultural leaders, the study provides evidence of Pentecostal exclusivity, excessive allegiance to leaders, and a shift away from ethnic-based patronage to Pentecostal patronage. As Pentecostalism continues to expand, these findings suggest a modification in the exchange of resources for loyalty in Africa, and grounds for viewing the movement as a new form of big man rule in the region.
Development and Validity of the Emotion and Motivation Self-Regulation Questionnaire (EMSR-Q)
Authors: Alonso-Tapia Jesús , Panadero Calderón Ernesto , Díaz Ruiz Miguel A.
Published: July 2014

This study has two objectives, first, to develop and validate the “Emotion and Motivation Self-regulation Questionnaire” (EMSR-Q), and second, to analyze (in the context of the questionnaire validation process) the relationships between self-regulation styles (SRS) rooted in goal orientations, and classroom motivational climate (CMC). A total of 664 Secondary Education students from Madrid (Spain) formed the sample of the study. It was divided randomly in two groups to perform confirmatory factor analysis and to cross-validate the results. Both analyses supported a five first-order factor structure, organized around two second-order factors, “Learning self-regulation style” (LSR) and “Avoidance self-regulation style” (ASR): (χ2/df = 2.71; GFI = .89; IFI = .84; CFI = .84; RMSEA = .07). Hypotheses concerning the relationships between SRS, goal orientations and expectancies are supported by additional correlation and factor analyses. Moreover, several regression analyses supported for the most part of the remaining hypotheses concerning the role of self-regulation styles as predictors of classroom motivational climate (CMC) perception, of change in self-regulation attributed to teacher work, and of students’ satisfaction with this same work. Theoretical and practical implications are discussed.
Managing Multiple Roles: Development of the Work-Family Conciliation Strategies Scale
Authors: Matias Marisa , Fontaine Anne Marie
Published: July 2014

Juggling the demands of work and family is becoming increasingly difficult in today's world. As dual-earners are now a majority and men and women's roles in both the workplace and at home have changed, questions have been raised regarding how individuals and couples can balance family and work. Nevertheless, research addressing work-family conciliation strategies is limited to a conflict-driven approach and context-specific instruments are scarce. This study develops an instrument for assessing how dual-earners manage their multiple roles detaching from a conflict point of view highlighting the work-family conciliation strategies put forward by these couples. Through qualitative and quantitative procedures the Work-Family Conciliation Strategies Scales was developed and is composed by 5 factors: Couple Coping; Positive Attitude Towards Multiple Roles, Planning and Management Skills, Professional Adjustments and Institutional Support; with good adjustment [χ2/df = 1.22; CFI = .90, RMSEA = .04, SRMR = .08.] and good reliability coefficients [from .67 to .87]. The developed scale contributes to research because of its specificity to the work-family framework and its focus on the proactive nature of balancing work and family roles. The results support further use of this instrument.
Stem memory T cells (TSCM)—their role in cancer and HIV immunotherapies
Authors: Flynn Jacqueline K , Gorry Paul R
Published: July 2014

Stem memory T cells (TSCM) have been described in mice, non‐human primates and in humans, constituting approximately 2–4% of the total CD4+ and CD8+ T‐cell population in the periphery. TSCM represent the earliest and long‐lasting developmental stage of memory T cells, displaying stem cell‐like properties, and exhibiting a gene profile between naïve and central memory T cells. Their self‐renewal capacity and long‐term survival has sparked interest in the cancer and human immunodeficiency virus (HIV) fields. How and when the formation of TSCM occurs during the immune response to pathogens and the therapeutic potential of these cells are currently being investigated. This review will explore the potential role of TSCM to be used as, or targeted by, immunotherapies and vaccines for treatment of cancer and HIV.
Revealing the micromechanisms behind semi-solid metal deformation with time-resolved X-ray tomography
Authors: Kareh K. M. , Lee P. D. , Atwood R. C. , Connolley T. , Gourlay C. M.
Published: July 2014

The behaviour of granular solid–liquid mixtures is key when deforming a wide range of materials from cornstarch slurries to soils, rock and magma flows. Here we demonstrate that treating semi-solid alloys as a granular fluid is critical to understanding flow behaviour and defect formation during casting. Using synchrotron X-ray tomography, we directly measure the discrete grain response during uniaxial compression. We show that the stress–strain response at 64–93% solid is due to the shear-induced dilation of discrete rearranging grains. This leads to the counter-intuitive result that, in unfed samples, compression can open internal pores and draw the free surface into the liquid, resulting in cracking. A soil mechanics approach shows that, irrespective of initial solid fraction, the solid packing density moves towards a constant value during deformation, consistent with the existence of a critical state in mushy alloys analogous to soils.
Guest-induced supramolecular chirality in a ditopic azoprobe–cyclodextrin complex in water
Authors: Nonaka Kentaro , Yamaguchi Mai , Yasui Masashi , Fujiwara Shoji , Hashimoto Takeshi , Hayashita Takashi
Published: July 2014

The novel supramolecular sensors induced by the clockwise twisted structures due to multi-point recognition in water.
Unique ultrafast energy transfer in a series of phenylene-bridged subporphyrin–porphyrin hybrids
Authors: Oh Juwon , Sung Jooyoung , Kitano Masaaki , Inokuma Yasuhide , Osuka Atsuhiro , Kim Dongho
Published: July 2014

A series of phenylene-bridged subporphyrin–Zn(ii) porphyrin (SubP–ZnP) hybrid systems undergo extraordinarily fast excitation energy transfer (EET) processes from the SubP to the ZnP, aided by conjugative electronic elongation of the SubP to the phenylene-bridge.
Copper-catalyzed intermolecular azidocyanation of aryl alkenes
Authors: Xu Li , Mou Xue-Qing , Chen Zhi-Min , Wang Shao-Hua
Published: July 2014

A copper-catalyzed Markovnikov-type intermolecular azidocyanation of aryl alkenes has been developed for the first time.
Transmission electron microscopy enables the reconstruction of the catenane and ring forms of CS2 hydrolase
Authors: Wang Joseph Che-Yen , Zlotnick Adam , Mecinović Jasmin
Published: July 2014

Transmission electron microscopic studies on CS2 hydrolase provide direct evidence for the existence of the hexadecameric catenane and octameric ring topologies. Reconstructions of both protein assemblies are in good agreement with crystallographic analyses.
C60 fullerenol as an active and stable catalyst for the synthesis of cyclic carbonates from CO2 and epoxides
Authors: Sun Yong-Bin , Cao Chang-Yan , Yang Shu-Liang , Huang Pei-Pei , Wang Chun-Ru , Song Wei-Guo
Published: July 2014

C60 fullerenol was first found to be a highly active, selective and stable catalyst for cycloaddition of CO2 and epoxides to produce various cyclic carbonates with excellent yields (89–99%). A solid/liquid interfacial hydrogen-bond assisted mechanism was proposed to account for its high efficiency.
Mn(ii) coordination polymers assembled from 8 or 9-connected trinuclear secondary building units: topology analysis and research of magnetic properties
Authors: Liu Lu , Lv Xiaofeng , Zhang Lin , Guo Li'an , Wu Jie , Hou Hongwei , Fan Yaoting
Published: July 2014

Two highly-connected trinuclear Mn(ii)-cluster polymers were successfully fabricated. The FC and ZFC data of 1 show a divergence over a temperature range of 40–3.5 K. 2 features a ferrimagnetic chain with a (5/2, 10/2) spin topology.
Electronic transport, transition-voltage spectroscopy, and the Fano effect in single molecule junctions composed of a biphenyl molecule attached to metallic and semiconducting carbon nanotube electrodes
Authors: Brito da Silva Júnior Carlos Alberto , Pereira Leal José Fernando , Pureza Aleixo Vicente Ferrer , Pinheiro Felipe A. , Del Nero Jordan
Published: July 2014

We investigate electronic transport in semiconductor–molecule–metal junctions consisting of a biphenyl molecule attached to a p-doped semiconductor and metallic carbon nanotubes.
Butterfly effects: novel functional materials inspired from the wings scales
Authors: Zhang Wang , Gu Jiajun , Liu Qinglei , Su Huilan , Fan Tongxiang , Zhang Di
Published: July 2014

This review will provide a perspective overview of the research inspired from butterfly wing structures in recent years.
Plasma chemical and chemical functionalization of polystyrene colloidal crystals
Authors: Wegewitz L. , Prowald A. , Meuthen J. , Dahle S. , Höfft O. , Endres F. , Maus-Friedrichs W.
Published: July 2014

A method to stabilize templates of colloidal crystals for subsequent electrochemical deposition from ionic liquids is presented.
Hydrogen bond dynamics of superheated water and methanol by ultrafast IR-pump and EUV-photoelectron probe spectroscopy
Authors: Vöhringer-Martinez E. , Link O. , Lugovoy E. , Siefermann K. R. , Wiederschein F. , Grubmüller H. , Abel B.
Published: July 2014

Snapshot of superheated water 40 ps after fs-IR laser excitation; representative aggregates formed during the simulation (close-up) compared to one obtained from superheated methanol phase (inset).
Ultrafast photo-induced ligand solvolysis of cis-[Ru(bipyridine)2(nicotinamide)2]2+: experimental and theoretical insight into its photoactivation mechanism
Authors: Greenough Simon E. , Roberts Gareth M. , Smith Nichola A. , Horbury Michael D. , McKinlay Russell G. , Żurek Justyna M. , Paterson Martin J. , Sadler Peter J. , Stavros Vasilios G.
Published: July 2014

Kinetic model of a Ru(ii) pyridyl complex for potential use in photodynamic therapy.
A microchip platform for interrogating tumor–macrophage paracrine signaling at the single-cell level
Authors: Elitas Meltem , Brower Kara , Lu Yao , Chen Jonathan J. , Fan Rong
Published: July 2014

An antibody barcode microchamber array chip permits the measurement of secreted proteins from pairs of individual tumor and macrophage cells and quantifying paracrine signaling-induced functional changes.
A polydimethylsiloxane–polycarbonate hybrid microfluidic device capable of generating perpendicular chemical and oxygen gradients for cell culture studies
Authors: Chang Chia-Wen , Cheng Yung-Ju , Tu Melissa , Chen Ying-Hua , Peng Chien-Chung , Liao Wei-Hao , Tung Yi-Chung
Published: July 2014

This paper reports a PDMS–PC hybrid microfluidic device capable of performing cell culture under combinations of chemical and oxygen gradients.
Informative Bayesian Model Selection: a method for identifying interactions in genome-wide data
Authors: Aflakparast Mehran , Masoudi-Nejad Ali , . Bozorgmehr Joseph H , Visweswaran Shyam
Published: July 2014

In high-dimensional genome-wide (GWA) data, a key challenge is to detect genomic variants that interact in a nonlinear fashion in their association with disease.
Effect of conformational rigidity on the stereoselectivity of nucleophilic additions to five-membered ring bicyclic oxocarbenium ion intermediates
Authors: Lavinda Olga , Tran Vi Tuong , Woerpel K. A.
Published: July 2014

Nucleophilic substitution reactions of five-membered ring acetals bearing fused rings reveal that subtle changes in the structure of the fused ring can exert dramatic influences on selectivity.
Solid-phase peptide synthesis: an overview focused on the preparation of biologically relevant peptides
Authors: Palomo Jose M.
Published: July 2014

Tailor-made design preparation of complex peptide sequence including posttranslational modifications, fluorescent labels, unnatural amino acids are of exceptional value for biological studies of several important diseases. The possibility to obtain these molecules in sufficient amounts in relative short time is thanks to the solid-phase approach.
Simple and efficient synthesis of tetrahydro-β-carbolines via the Pictet–Spengler reaction in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)
Authors: Wang Li-Na , Shen Su-Li , Qu Jin
Published: July 2014

1,1,1,3,3,3-Hexafluoro-2-propanol (HFIP) can act as both the solvent and the catalyst to effectively promote the Pictet–Spengler reaction.
Magnetic and electrical properties of three-dimensional (La,Pr,Ca)MnO3 nanofilm/ZnO nanorod p–n junctions
Authors: Zheng Ming , Zhu Qiu-Xiang , Li Xue-Yan , Li Xiao-Min , Zheng Ren-Kui
Published: July 2014

Excellent room temperature rectification performance and enhanced ferromagnetic phase transition temperature was achieved for the La0.5Pr0.17Ca0.33MnO3 nanofilm/ZnO nanorod p–n junctions prepared by depositing the La0.5Pr0.17Ca0.33MnO3 shell layer on the ZnO nanorods.
Reinforced shape-tunable microwrinkles formed on a porous-film-embedded elastomer surface
Authors: Ohzono T. , Hirai Y. , Suzuki K. , Shimomura M. , Uchida N.
Published: July 2014

A new structural design for wrinkling to improve mechanical durability by exploiting a porous polymer film embedded on the surface of an elastomer is proposed. The embedded thin porous film acts as a hard layer, which buckles into wrinkles, and the interpenetrated structure effectively suppresses fatal failures such as delamination and cracking.
High performance LiMnPO4/C prepared by a crystallite size control method
Authors: Zhao Ming , Fu Yu , Xu Ning , Li Guoran , Wu Mengtao , Gao Xueping
Published: July 2014

The as-prepared LiMnPO4/C sample presents higher discharge potential plateau, larger discharge capacity, excellent high-rate capability, and good cycle stability.
Getting real: influence of structural disorder on the performance of plasmonic hole array sensors fabricated by a bottom-up approach
Authors: Quint S. B. , Pacholski C.
Published: July 2014

Periodic hole arrays in gold films showing extraordinary transmission of light are fabricated using solely chemical methods. The degree of order of the hole arrays has a strong impact on their transmission properties, which can be utilized for a spectral quality control of the produced plasmonic sensors.
Current Trends in Pediatric Cochlear Implant Candidate Selection and Postoperative Follow-Up
Authors: Uhler Kristin , Gifford René H.
Published: July 2014

Purpose

In this article, the authors describe current pediatric cochlear implant (CI) assessment and postoperative scheduling protocols in the United States.

Method

A survey was conducted in 2 phases.

Results

Response rates were similar between Phase I (10%) and Phase II (13%). Across phases, nearly all respondents reported assessing speech perception both preoperatively and postoperatively. The most frequently used parent questionnaires were the Infant–Toddler Meaningful Auditory Integration Scale (Robbins, Renshaw, & Berry, 1991), the Meaningful Auditory Integration Scale (Robbins et al., 1991), and LittlEARS (Kuehn-Inacken, Weichboldt, Tsiakpini, Coninx, & D'Haese, 2003). The most commonly used speech perception measure for children <23 months of age was the Early Speech Perception Test–Low Verbal (ESP-LV; Moog & Geers, 1990). The most commonly used measures for children 24–35 months of age were the ESP-LV, the Northwestern University of Children's Perception of Speech (Elliot & Katz, 1980), and the Mr. Potato Head task (Robbins, 1993). For children >36 months of age, there was a wide variety of speech perception tests utilized. Patient follow-up visits were weekly or biweekly immediately following CI activation, then every 3 months for the remainder of the 1st year. After the 1st year, most children were seen semiannually.

Conclusions

Although trends emerged, there is a lack of consistency in the selection of speech perception measures utilized across centers for children <36 months of age. The development of a working group to establish a standard minimum pediatric test battery (similar to the adult Minimum Speech Test Battery) would promote uniformity in clinical protocols used to assess children who receive CIs.
Children's Understanding of Instructions Presented in Noise and Reverberation
Authors: Lewis Dawna E. , Manninen Crystal M. , Valente Daniel L. , Smith Nicholas A.
Published: July 2014

Purpose

This study examined children's ability to follow audio–visual instructions presented in noise and reverberation.

Method

Children (8–12 years of age) with normal hearing followed instructions in noise or noise plus reverberation. Performance was compared for a single talker (ST), multiple talkers speaking one at a time (MT), and multiple talkers with competing comments from other talkers (MTC). Working memory was assessed using measures of digit span.

Results

Performance was better for children in noise than for those in noise plus reverberation. In noise, performance for ST was better than for either MT or MTC, and performance for MT was better than for MTC. In noise plus reverberation, performance for ST and MT was better than for MTC, but there were no differences between ST and MT. Digit span did not account for significant variance in the task.

Conclusions

Overall, children performed better in noise than in noise plus reverberation. However, differing patterns across conditions for the 2 environments suggested that the addition of reverberation may have affected performance in a way that was not apparent in noise alone. Continued research is needed to examine the differing effects of noise and reverberation on children's speech understanding.
An Overview of Managing Stuttering in Japan
Authors: Chu Shin Ying , Sakai Naomi , Mori Koichi
Published: July 2014

Purpose

The purpose of this article is to describe the rapid development of speech-language pathology in Japan since governmental licensing started in 1997 and to summarize the current trends in assessing and treating stuttering for preschoolers, school-age children, adolescents, and adults.

Method

The authors review relevant information about the current assessment and treatment services for people who stutter in Japan and discuss the issues and challenges faced by speech-language pathologists in managing stuttering.

Conclusion

It is predicted that as expertise in stuttering grows in Japan, the role of stuttering specialists in allied health, school districts, and research will increase.
The Rules of the Game: Properties of a Database of Expository Language Samples
Authors: Heilmann John , Malone Thomas O.
Published: July 2014

Purpose

The authors created a database of expository oral language samples with the aims of describing the nature of students' expository discourse and providing benchmark data for typically developing preteen and teenage students.

Method

Using a favorite game or sport protocol, language samples were collected from 235 typically developing students in Grades 5, 6, 7, and 9. Twelve language measures were summarized from this database and analyses were completed to test for differences across ages and topics. To determine whether distinct dimensions of oral language could be captured with language measures from these expository samples, a factor analysis was completed.

Results

Modest differences were observed in language measures across ages and topics. The language measures were effectively classified into four distinct dimensions: syntactic complexity, expository content, discourse difficulties, and lexical diversity.

Conclusion

Analysis of expository data provides a functional and curriculum-based assessment that has the potential to allow clinicians to document multiple dimensions of children's expressive language skills. Further development and testing of the database will establish the feasibility of using it to compare individual students' expository discourse skills to those of their typically developing peers.
Evolutionary dynamics of morphological stability in a long‐term experiment with Escherichia coli
Authors: Cui Fangshu , Yuan Bo
Published: July 2014

To investigate the questions in morphological evolution, some biologists seek to carry out evolution experiments owing to the incompleteness and uncontrollability of the fossil record and natural populations. To quantitatively analyse the morphology (cell size) evolution observed from a long‐term experiment with Escherichia coli, the authors present three mathematical approximations to the Wright–Fisher model of the morphological evolution. They firstly use a deterministic approximation, which fails to predict evolutionary dynamics of cell size and proves the importance of stochasticity in large populations. Then, they develop a stochastic approximation and derive an analytic expression for the anticipated waiting time to reach the stability of cell size. The results show that the calculation of this waiting time is in good agreement with the experimental data and that the selective advantage plays a prominent role in cell size evolution, with mutation rate and population size having less impact. Finally, they employ a multistep process to approximate the Wright–Fisher model of cell size evolution and acquire an analytical formula for the median waiting time until the stability of cell size. This median time supports the idea that the selective advantage is the dominant force for the morphological evolution in the long‐term experiment.
A photoelectron spectroscopy and ab initio study of the structures and chemical bonding of the B25− cluster
Authors: Piazza Zachary A. , Popov Ivan A. , Li Wei-Li , Pal Rhitankar , Cheng Zeng Xiao , Boldyrev Alexander I. , Wang Lai-Sheng
Published: July 2014

Photoelectron spectroscopy and ab initio calculations are used to investigate the structures and chemical bonding of the B25− cluster. Global minimum searches reveal a dense potential energy landscape with 13 quasi-planar structures within 10 kcal/mol at the CCSD(T)/6-311+G(d) level of theory. Three quasi-planar isomers (I, II, and III) are lowest in energy and nearly degenerate at the CCSD(T) level of theory, with II and III being 0.8 and 0.9 kcal/mol higher, respectively, whereas at two density functional levels of theory isomer III is the lowest in energy (8.4 kcal/mol more stable than I at PBE0/6-311+G(2df) level). Comparison with experimental photoelectron spectroscopic data shows isomer II to be the major contributor while isomers I and III cannot be ruled out as minor contributors to the observed spectrum. Theoretical analyses reveal similar chemical bonding in I and II, both involving peripheral 2c-2e B−B σ-bonding and delocalized interior σ- and π-bonding. Isomer III has an interesting elongated ribbon-like structure with a π-bonding pattern analogous to those of dibenzopentalene. The high density of low-lying isomers indicates the complexity of the medium-sized boron clusters; the method dependency of predicting relative energies of the low-lying structures for B25− suggests the importance of comparison with experiment in determining the global minima of boron clusters at this size range. The appearance of many low-lying quasi-planar structures containing a hexagonal hole in B25− suggests the importance of this structural feature in maintaining planarity of larger boron clusters.
Exotic exchange bias at epitaxial ferroelectric-ferromagnetic interfaces
Authors: Paul Amitesh , Reitinger Christoph , Autieri Carmine , Sanyal Biplab , Kreuzpaintner Wolfgang , Jutimoosik Jaru , Yimnirun Rattikorn , Bern Francis , Esquinazi Pablo , Korelis Panagiotis , Böni Peter
Published: July 2014

Multiferroics in spintronics have opened up opportunities for future technological developments, particularly in the field of ferroelectric (FE)-ferromagnetic (FM) oxide interfaces with functionalities. We find strong exchange bias shifts (up to 84 Oe) upon field cooling in metal-oxide (Fe/BaTiO3) films combining FM and FE layers. The saturation magnetic moment of the FM layer is also significantly higher than in bulk (3.0 ± 0.2 μB/atom) and the reversal mechanism occurs via a domain nucleation process. X-ray absorption spectroscopy at the Fe K-edge and Ba L3-edge indicate presence of few monolayers of antiferromagnetic FeO at the interface without the formation of any BaFeO3 layer. Polarized neutron reflectometry corroborates with our magnetization data as we perform depth profiling of the magnetic and structural densities in these bilayers. Our first principles density functional calculations support the formation of antiferromagnetic FeO layers at the interface along with an enhancement of Fe magnetic moments in the inner ferromagnetic layers.
A novel femtosecond-gated, high-resolution, frequency-shifted shearing interferometry technique for probing pre-plasma expansion in ultra-intense laser experiments
Authors: Feister S. , Nees J. A. , Morrison J. T. , Frische K. D. , Orban C. , Chowdhury E. A. , Roquemore W. M.
Published: July 2014

Ultra-intense laser-matter interaction experiments (>1018W/cm2) with dense targets are highly sensitive to the effect of laser “noise” (in the form of pre-pulses) preceding the main ultra-intense pulse. These system-dependent pre-pulses in the nanosecond and/or picosecond regimes are often intense enough to modify the target significantly by ionizing and forming a plasma layer in front of the target before the arrival of the main pulse. Time resolved interferometry offers a robust way to characterize the expanding plasma during this period. We have developed a novel pump-probe interferometry system for an ultra-intense laser experiment that uses two short-pulse amplifiers synchronized by one ultra-fast seed oscillator to achieve 40-fs time resolution over hundreds of nanoseconds, using a variable delay line and other techniques. The first of these amplifiers acts as the pump and delivers maximal energy to the interaction region. The second amplifier is frequency shifted and then frequency doubled to generate the femtosecond probe pulse. After passing through the laser-target interaction region, the probe pulse is split and recombined in a laterally sheared Michelson interferometer. Importantly, the frequency shift in the probe allows strong plasma self-emission at the second harmonic of the pump to be filtered out, allowing plasma expansion near the critical surface and elsewhere to be clearly visible in the interferograms. To aid in the reconstruction of phase dependent imagery from fringe shifts, three separate 120° phase-shifted (temporally sheared) interferograms are acquired for each probe delay. Three-phase reconstructions of the electron densities are then inferred by Abel inversion. This interferometric system delivers precise measurements of pre-plasma expansion that can identify the condition of the target at the moment that the ultra-intense pulse arrives. Such measurements are indispensable for correlating laser pre-pulse measurements with instantaneous plasma profiles and for enabling realistic Particle-in-Cell simulations of the ultra-intense laser-matter interaction.
High tunability of the work function of (001) surface of ReO3 with O-vacancies: First principles analysis
Authors: Suchitra  , Pan Jaysree , Waghmare Umesh V.
Published: July 2014

Physical and chemical properties of transition metal oxides are central to the emerging field of oxide electronics. However, they are greatly influenced by defects, particularly, oxygen vacancies, which are always present in oxides. Here, we show how the control of oxygen vacancies at (001) surface of ReO3 can be used to tune its work function from 7 to 3 eV, based on first-principles density functional theoretical calculations of its structure, electronic and magnetic properties. The work function is shown to correlate directly with the stability of surface and exhibit a linear dependence on surface energy. We further assess the stability of ReO3 surface by determining its phonon dispersion, and explain how the surface stresses effectively strengthen structural instability leading to size dependence of its pressure dependent structural phase transitions observed experimentally. Our results highlight how significantly oxygen vacancies alter the work function of a metallic oxide and has important consequences to development of electronic devices and catalysts based on oxide heterostructures.
One- and two-photon absorption in solution: The effects of a passive auxiliary beam
Authors: Ford J. S. , Andrews D. L.
Published: July 2014

The efficiencies of one- and two-photon absorption by chromophores in solution may be significantly modified by a sufficiently intense beam of off-resonant light. A molecular analysis based on quantum electrodynamics (QED) fully accounts for this phenomenon of laser-modified absorption. A time-dependent perturbation-theory treatment describes the process in terms of stimulated forward Rayleigh-scattering of the auxiliary beam occurring simultaneously with the absorption interaction(s). Our formulation accommodates media modifications to the basic character of light-matter interactions, taking into account the refractive and dispersive properties of a solution-phase environment. This introduces the bulk refractive index of the solvent directly into the QED framework. The measurable electronic response of molecules freely rotating in solution is defined by an average of all orientations. We explicitly derive fixed-orientation and rotationally averaged calculations for the Fermi-rule rate of laser-modified one- and two-photon absorption. For a given beam polarization geometry, the solution-phase molecular response is expressible as a set of natural invariant scalars. These results reveal details of the dependence on the beam polarisations and on the rotationally averaged molecular response: we illustrate the breadth of variation available via geometric manipulation of beam polarization, and raise new possibilities for quantum weak measurements of laser states.
Conceptual design of a fast-ion D-alpha diagnostic on experimental advanced superconducting tokamak
Authors: Huang J. , Heidbrink W. W. , Wan B. , von Hellermann M. G. , Zhu Y. , Gao W. , Wu C. , Li Y. , Fu J. , Lyu B. , Yu Y. , Shi Y. , Ye M. , Hu L. , Hu C.
Published: July 2014

To investigate the fast ion behavior, a fast ion D-alpha (FIDA) diagnostic system has been planned and is presently under development on Experimental Advanced Superconducting Tokamak. The greatest challenges for the design of a FIDA diagnostic are its extremely low intensity levels, which are usually significantly below the continuum radiation level and several orders of magnitude below the bulk-ion thermal charge-exchange feature. Moreover, an overlaying Motional Stark Effect (MSE) feature in exactly the same wavelength range can interfere. The simulation of spectra code is used here to guide the design and evaluate the diagnostic performance. The details for the parameters of design and hardware are presented.
Using X-mode L, R and O-mode reflectometry cutoffs to measure scrape-off-layer density profiles for upgraded ORNL reflectometer on NSTX-U
Authors: Lau C. , Wilgen J. B. , Caughman J. B. , Hanson G. R. , Hosea J. , Perkins R. , Ryan P. M. , Taylor G.
Published: July 2014

The pre-existing ORNL scrape-off-layer (SOL) reflectometer that operated with the X-mode R-cutoff at 6-27 GHz to measure SOL density profiles on NSTX is being upgraded to be functional at the increased magnetic fields on NSTX-U spherical tokamak. Rather than increasing the operating frequencies to measure the higher X-mode R-cutoff frequencies on NSTX-U, it will be shown that the combined use of the X-mode R, L and O-mode cutoffs at 6-27 GHz can obtain the desired SOL density profiles. The potential capabilities and obstacles of this technique to measure SOL density profiles and possibly SOL magnetic field profiles on NSTX-U will be discussed.
Does liquid slippage within a rough channel always increase the flow rate?
Authors: Lee Anna , Kim Ho-Young
Published: July 2014

Slippage of liquid over rough superhydrophobic surfaces that induce the Cassie-Baxter state decreases frictional force on the flow. This may easily lead to a hasty conclusion that liquid slip enhances the flow rate in rough channels. Here, we show that flow rates can be rather reduced by roughening and hydrophobizing microchannel walls to support liquid slippage, depending on the topography of the roughness. We consider theoretical models that predict liquid flow rates in channels of different roughness and wetting conditions, to construct criteria for the surface structure that determine whether slip or no-slip would be advantageous in enhancing flow rates. It is shown that liquid slips are advantageous only in channels with highly hydrophobic, short, sparsely distributed protrusions. We corroborate our theoretical predictions with microchannels decorated with micropillars of varying wettabilities.
Development of microwave imaging reflectometry on the HL-2A tokamak
Authors: Zhongbing Shi , Min Jiang , Yonglong Che , Bin Wang , Yong Yin , Lin Meng , Wulu Zhong , Wei Chen , Peiwan Shi , Zhetian Liu , Binzhong Fu , Xuantong Ding , Yi Liu , Qingwei Yang , Xuru Duan
Published: July 2014

A microwave imaging reflectometry system has been developed to visualize the density fluctuations on the HL-2A tokamak. This system is characterized by a quasi-optical system, a four frequency microwave transmitter, and a microwave quadrature receiver system with a 3D adjustable U-shaped horn antenna array, that generate 8 (poloidal) × 4 (radial) × 2 (toroidal) = 64 channel images of density fluctuations. Simulations and laboratory tests of the optical system have been conducted. The test results are in good agreement with the simulations.
Glass transition and relaxation dynamics of propylene glycol–water solutions confined in clay
Authors: Elamin Khalid , Björklund Jimmy , Nyhlén Fredrik , Yttergren Madeleine , Mårtensson Lena , Swenson Jan
Published: July 2014

The molecular dynamics of aqueous solutions of propylene glycol (PG) and propylene glycol methylether (PGME) confined in a two-dimensional layer-structured Na-vermiculite clay has been studied by broadband dielectric spectroscopy and differential scanning calorimetry. As typical for liquids in confined geometries the intensity of the cooperative α-relaxation becomes considerably more suppressed than the more local β-like relaxation processes. In fact, at high water contents the calorimetric glass transition and related structural α-relaxation cannot even be observed, due to the confinement. Thus, the intensity of the viscosity related α-relaxation is dramatically reduced, but its time scale as well as the related glass transition temperature Tg are for both systems only weakly influenced by the confinement. In the case of the PGME-water solutions it is an important finding since in the corresponding bulk system a pronounced non-monotonic concentration dependence of the glass transition related dynamics has been observed due to the growth of hydrogen bonded relaxing entities of water bridging between PGME molecules [J. Sjöström, J. Mattsson, R. Bergman, and J. Swenson, Phys. Chem. B 115, 10013 (2011)]. The present results suggest that the same type of structural entities are formed in the quasi-two-dimensional space between the clay platelets. It is also observed that the main water relaxation cannot be distinguished from the β-relaxation of PG or PGME in the concentration range up to intermediate water contents. This suggests that these two processes are coupled and that the water molecules affect the time scale of the β-relaxation. However, this is most likely true also for the corresponding bulk solutions, which exhibit similar time scales of this combined relaxation process below Tg. Finally, it is found that at higher water contents the water relaxation does not merge with, or follow, the α-relaxation above Tg, but instead crosses the α-relaxation, indicating that the two relaxation processes are independent of each other. This can only occur if the two processes do not occur in the same parts of the confined solutions. Most likely the hydration shell of the interlayer Na+ ions is causing this water relaxation, which does not participate in the α-relaxation at any temperature.
Scandium induced structural transformation and B′:B″ cationic ordering in Pb(Fe0.5Nb0.5)O3 multiferroic ceramics
Authors: Mallesham B. , Ranjith R. , Manivelraja M.
Published: July 2014

The current study explores non-magnetic Sc3+ induced structural transformation, evolution of local B-site cation ordering and associated effect on ferroelectric phase transition temperature Tmax (temperature corresponding to dielectric maxima) on increasing the atom percent of Sc substitution in [Pb(Fe0.5Nb0.5)O3 (PFN)] ceramics. In this regard, the phase pure Pb[(Fe0.5−xScx)Nb0.5]O3 ceramics with x varying from 0 to 0.5 were synthesized through solid state reaction route. The detailed structural analysis through Rietveld refinement confirms the room temperature transformation from a monoclinic Cm to rhombohedral R3m structure at x = 0.3 mol. % of Sc. Absorption spectra studies show that there is a considerable increment in the bandgap at higher scandium content. Most interestingly, the Tmax exhibited an increment for lower scandium contents (x = 0.1 to 0.25) followed by a drop in Tmax (x = 0.3 to 0.5). Such anomalous behavior in Tmax is expected to arise due to the onset of B′, B″ local cation ordering beyond Sc content x = 0.25. The B-site cation ordering at and beyond x = 0.3 was also confirmed by the evolution of cation order induced Pb-O coupled vibrational mode in Raman scattering studies. In addition, the Mössbauer spectra of PFN (x = 0) and Pb(Fe0.4Sc0.1Nb0.5)O3 (x = 0.1) are reported to verify the spin state and oxidation state of iron. The lattice distortion due to the radius ratio difference between a Sc3+ cation and Fe3+ cation in low spin state is responsible for the structural transformation, which in turn facilitates a B′:B″ cation ordering.
Ion-temperature-gradient sensitivity of the hydrodynamic instability caused by shear in the magnetic-field-aligned plasma flow
Authors: Mikhailenko V. V. , Mikhailenko V. S. , Lee Hae June , Koepke M. E.
Published: July 2014

The cross-magnetic-field (i.e., perpendicular) profile of ion temperature and the perpendicular profile of the magnetic-field-aligned (parallel) plasma flow are sometimes inhomogeneous for space and laboratory plasma. Instability caused either by a gradient in the ion-temperature profile or by shear in the parallel flow has been discussed extensively in the literature. In this paper, (1) hydrodynamic plasma stability is investigated, (2) real and imaginary frequency are quantified over a range of the shear parameter, the normalized wavenumber, and the ratio of density-gradient and ion-temperature-gradient scale lengths, and (3) the role of inverse Landau damping is illustrated for the case of combined ion-temperature gradient and parallel-flow shear. We find that increasing the ion-temperature gradient reduces the instability threshold for the hydrodynamic parallel-flow shear instability, also known as the parallel Kelvin-Helmholtz instability or the D'Angelo instability. We also find that a kinetic instability arises from the coupled, reinforcing action of both free-energy sources. For the case of comparable electron and ion temperature, we illustrate analytically the transition of the D'Angelo instability to the kinetic instability as (a) the shear parameter, (b) the normalized wavenumber, and (c) the ratio of density-gradient and ion-temperature-gradient scale lengths are varied and we attribute the changes in stability to changes in the amount of inverse ion Landau damping. We show that near a normalized wavenumber k⊥ρi of order unity (i) the real and imaginary values of frequency become comparable and (ii) the imaginary frequency, i.e., the growth rate, peaks.