bluuebunny/crossref_metadata_2025 huggingface dataset:
Erectile Dysfunction Among HIV Patients Undergoing Highly Active Antiretroviral Therapy: Dyslipidemia as a Main Risk Factor
Authors: Romero-Velez Gustavo , Lisker-Cervantes Andrés , Villeda-Sandoval Christian I. , Sotomayor de Zavaleta Mariano , Olvera-Posada Daniel , Sierra-Madero Juan Gerardo , Arreguin-Camacho Lucrecia O. , Castillejos-Molina Ricardo A.
Published: March 2014

Objective

To assess the prevalence and risk factors of erectile dysfunction (ED) in HIV patients from the HIV clinic of a tertiary referral center in Mexico City.

Design

Prevalence was obtained from cross-sectional studies, and the International Index of Erectile Function (IIEF), a standardized method, was used to assess ED.

Methods

A cross-sectional study was performed in the HIV clinic. Participants completed the IIEF to allow ED assessment. Information on demographics, clinical and HIV-related variables was retrieved from their medical records.

Results

One hundred and nine patients were included, with a mean age of 39.9 ± 8.8 years. ED was present in 65.1% of the individuals. Patients had been diagnosed with HIV for a mean of 92.7 ± 70.3 months and had undergone a mean 56.4 ± 45.5 months of HAART. The only variable associated with ED in the univariate analysis was dyslipidemia, and this association was also found in the multivariate analysis (P = 0.01).

Conclusions

ED is highly prevalent in HIV patients. Dyslipidemia should be considered as a risk factor for ED in HIV patients.
Mimicking Bubble Use in Nature: Propulsion of Janus Particles due to Hydrophobic‐Hydrophilic Interactions
Authors: Pinchasik Bat‐El , Möhwald Helmuth , Skirtach Andre G.
Published: March 2014

Bubbles are widely used by animals in nature in order to fulfill important functions. They are used by animals in order to walk underwater or to stabilize themselves at the water/air interface. The main aim of this work is to imitate such phenomena, which is the essence of biomimetics. Here, bubbles are used to propel and to control the location of Janus particles in an aqueous medium. The synthesis of Janus SiO2‐Ag and polystyrene‐Ag (PS‐Ag) particles through embedment in Parafilm is presented. The Janus particles, partially covered with catalytically active Ag nanoparticles, are redispersed in water and placed on a glass substrate. The active Ag sites are used for the splitting of H2O2 into water and oxygen. As a result, an oxygen bubble is formed on one side of the particle and promotes its propulsion. Once formed, the bubble‐particle complex is stable and therefore, can be manipulated by tuning hydrophilic‐hydrophobic interactions with the surface. In this way a transition between two‐ and three‐ dimensional motion is possible by changing the hydrophobicity of the substrate. Similar principles are used in nature.
Sexual dimorphism and courtship behavior in Drosophila prolongata
Authors: Setoguchi Shiori , Takamori Hisaki , Aotsuka Tadashi , Sese Jun , Ishikawa Yukio , Matsuo Takashi
Published: March 2014

Sexual dimorphism is often derived from sexual selection. In sexually dimorphic Drosophila species, exaggerated male structures are used for specific behaviors in male-to-male competition or courtship toward females. In Drosophila prolongata, a member of the melanogaster species group, males have enlarged forelegs whereas females do not. However, the adaptive role of the enlarged forelegs is unclear because little is known about the behavior of D. prolongata. In this study, the courtship behavior of D. prolongata was investigated in comparison with closely related species. Males of D. prolongata use their forelegs in a specific behavior, “leg vibration”, in which the male vigorously vibrates the female’s abdomen by extending his forelegs from in front of her. Leg vibration was observed immediately before “attempting copulation”, indicating that it has an adaptive role in the mating process. In contrast, leg vibration was not observed in closely related species. Because the large forelegs are necessary to accomplish leg vibration, it was suggested that the sexual dimorphism of D. prolongata forelegs is currently under the influence of sexual selection in courtship behavior.
Cross‐Sectional Associations of Food Consumption with Plasma Fatty Acid Composition and Estimated Desaturase Activities in Finnish Children
Authors: Venäläinen Taisa , Schwab Ursula , Ågren Jyrki , de Mello Vanessa , Lindi Virpi , Eloranta Aino‐Maija , Kiiskinen Sanna , Laaksonen David , Lakka Timo A.
Published: March 2014

Plasma fatty acid (FA) composition is known to be an indicator of dietary fat quality, but the associations of other dietary factors with plasma FA composition remain unknown in children. We investigated the cross‐sectional associations of food consumption with the proportions of FA and estimated desaturase activities in plasma cholesteryl esters (CE) and phospholipids (PL) among children. The subjects were a population sample of 423 children aged 6–8 years examined at baseline of The Physical Activity and Nutrition in Children (PANIC) Study. We assessed food consumption by food records and plasma FA composition by gas chromatography. We used linear regression models adjusted for age, sex, physical activity and total energy intake to analyze the associations. A higher consumption of vegetable oil‐based margarine (fat 60–80 %) was associated with a higher proportion of linoleic and α‐linolenic acids in plasma CE and PL. A higher consumption of high‐fiber grain products was related to a lower proportion of oleic acid in CE and PL. The consumption of candy was directly associated with the proportion of palmitoleic and oleic acid in plasma CE. The consumption of vegetable oil‐based margarine was inversely associated with estimated stearoyl‐CoA‐desaturase activity in plasma CE and PL and the consumption of candy was directly related to it in plasma CE. The results of our study suggest that plasma FA composition is not only a biomarker for dietary fat quality but also reflects the consumption of high‐fiber grain products and foods high in sugar among children.
Global linear stability analysis of falling films with inlet and outlet
Authors: Albert C. , Tezuka A. , Bothe D.
Published: March 2014

In this paper, the stability of falling films with different flow conditions at the inlet is studied. This is done with an algorithm for the numerical investigation of stability of steady-state solutions to dynamical systems, which is based on an Arnoldi-type iteration. It is shown how this algorithm can be applied to free boundary problems in hydrodynamics. A volume-of-fluid solver is employed to predict the time evolution of perturbations to the steady state. The method is validated by comparison to data from temporal and spatial stability theory, and to experimental results. The algorithm is used to analyse the flow fields of falling films with inlet and outlet, taking the inhomogeneity caused by different inlet conditions into account. In particular, steady states with a curved interface are analysed. A variety of reasonable inlet conditions is investigated. The instability of the film is convective and perturbations at the inlet could be of importance since they are exponentially amplified as they are transported downstream. However, the employed algorithm shows that there is no significant effect of the inlet condition. It is concluded that the flow characteristics of falling films are stable with respect to the considered time-independent inlet conditions.
DNA methylation, ageing and the influence of early life nutrition
Authors: Lillycrop Karen A. , Hoile Samuel P. , Grenfell Leonie , Burdge Graham C.
Published: March 2014

It is well established that genotype plays an important role in the ageing process. However, recent studies have suggested that epigenetic mechanisms may also influence the onset of ageing-associated diseases and longevity. Epigenetics is defined as processes that induce heritable changes in gene expression without a change in the DNA nucleotide sequence. The major epigenetic mechanisms are DNA methylation, histone modification and non-coding RNA. Such processes are involved in the regulation of tissue-specific gene expression, cell differentiation and genomic imprinting. However, epigenetic dysregulation is frequently seen with ageing. Relatively little is known about the factors that initiate such changes. However, there is emerging evidence that the early life environment, in particular nutrition, in early life can induce long-term changes in DNA methylation resulting in an altered susceptibility to a range of ageing-associated diseases. In this review, we will focus on the changes in DNA methylation that occur during ageing; their role in the ageing process and how early life nutrition can modulate DNA methylation and influence longevity. Understanding the mechanisms by which diet in early life can influence the epigenome will be crucial for the development of preventative and intervention strategies to increase well-being in later life.
Detecting objective and subjective cognitive effects of electroconvulsive therapy: intensity, duration and test utility in a large clinical sample
Authors: Fernie G. , Bennett D. M. , Currie J. , Perrin J. S. , Reid I. C.
Published: March 2014

Background

Electroconvulsive therapy (ECT) is an effective treatment for depression but the extent and persistence of cognitive side-effects remain uncertain. It has been reported that there is little evidence that impairments last longer than up to 15 days post-ECT. However, relatively few studies have followed patients for even as long as 1 month post-ECT. Here we report results from a brief cognitive battery given prior to ECT and repeated five times up to 6 months post-ECT.

Method

In a retrospective case-note study of routinely collected clinical data 126 patients treated with ECT completed two neuropsychological tests [Cambridge Neuropsychological Test Automated Battery (CANTAB) spatial recognition memory (SRM) and Mini Mental State Examination (MMSE)] and two subjective reports of memory function, prior to ECT. Patients were reassessed following ECT and at 1, 3 and 6 months post-ECT although not all patients completed all assessments.

Results

Performance relative to pre-ECT baseline was significantly poorer at each post-ECT assessment up to 3 months post-ECT using the CANTAB SRM, but was improved at 6 months. Conversely, MMSE score showed improvements relative to baseline from 1 month post-ECT. Mood and subjective memory scores improved following ECT and were correlated with one another, but not with either neuropsychological measure.

Conclusions

The CANTAB SRM task revealed reversible cognitive deficiencies relative to a pre-ECT baseline for at least 3 months following ECT, while MMSE score and patients' subjective reports showed only improvement. Visuospatial memory scores eventually exceeded baseline 6 months post-ECT.
Labor, Rematerialized: Putting Environments to Work in the Americas
Authors: Soluri John
Published: March 2014

The late Guyanese historian and political activist Walter Rodney began his posthumously publishedA History of the Guyanese Working People 1881–1905(1981) by analyzing the “physical environment and class interests” in coastal Guyana. Writing against narratives that privileged the roles played by European capital and technology, Rodney argued that working people made large contributions to the “humanization” of the Guyanese environment. He noted that a powerful planter class placed severe constraints on working people who were “in no position to control the available technology or to initiate environmental intervention.” Political power was important, but Rodney noted that the environment played “a determining role in limiting the activities ofallsections of the population [original emphasis].” Writing an “intelligible narrative” of Guyana's history then, was “impossible” without an understanding of Guyana's environment.
Taking the Measure of Labor: Rural Rationalization in Twentieth-Century Brazil
Authors: Rogers Thomas D.
Published: March 2014

Rural sugarcane workers in the Brazilian Northeast negotiated with planters in 1963 to establish guidelines for measuring jobs, producing a document they called the Task Table. This article situates the Table in historical context, placing it in a long-term process of agricultural rationalization that generated struggles over flexibility, control, and freedom on the job. The Table emerged at one moment in these battles and since conflicts like these over productivity, efficiency, and control are common to industrial and agricultural work alike, analyzing the Table offers insight into a broad struggle between workers and employers over the conditions and regulation of labor. For a region of hundreds of thousands of sugarcane workers, the Task Table reflected and facilitated the transformation of labor relationships, views of the working environment, and worker consciousness.
Visually impaired musicians’ insights: narratives of childhood, lifelong learning and musical participation
Authors: Baker David
Published: March 2014

With the support of the Royal National Institute of Blind People (RNIB), the life histories of five visually impaired (VI) musicians were collected and analysed between November 2011 and August 2012. This research was conducted as a pilot for a two-year, national investigation of VI musical participation, ‘Visually-impaired musicians’ lives’ (VIML) funded by the Arts and Humanities Research Council (AHRC, 2013–2015), which has brought together the Institute of Education, University of London, the RNIB and the Royal Academy of Music, London as project partners. In this instance, life histories were co-constructed narratives – foci were the self-identities of this unique group and ‘insider’ perspectives on education, musical participation and society. Analytic induction of the biographies revealed that a perceived barrier to lifelong learning was having the ability to read notation, either adapted print or in Braille format, and the access to educators who had expertise to teach musicians with visual impairments. The respondents commented on the great value of ensemble participation and adopting teaching roles too. With widespread lore in society about the exceptional musical abilities of those with visual impairment, longstanding traditions of blind musicianship, plus evidence of distinct neural development and hearing, they acknowledged the cachet associated with blind musicians but, regardless, wished to be considered musicians first and foremost. The findings raise questions about social and music educational inclusion.
Sometimes Psychopaths get it Right: A Utilitarian Response to ‘The Mismeasure of Morals’
Authors: PAYTAS TYLER
Published: March 2014

A well-publicized study entitled ‘The Mismeasure of Morals’ (Bartels and Pizarro, 2011) purportedly provides evidence that utilitarian solutions to a particular class of moral dilemmas are endorsed primarily by individuals with psychopathic traits. According to the authors, these findings give researchers reason to refrain from classifying utilitarian judgements as morally optimal. This article is a two-part response to the study. The first part comprises concerns about the methodology used and the adequacy of the data for supporting the authors’ conclusions. The second part seeks to undermine the suggestion that if anti-social individuals are the ones most likely to endorse utilitarian solutions to the target dilemmas, we should be sceptical about those solutions. I argue that the character of individuals most likely to make a given moral judgement is an unreliable indicator of the quality of that judgement.
The single-channel regime of transport through random media
Authors: Peña A. , Girschik A. , Libisch F. , Rotter S. , Chabanov A. A.
Published: March 2014

The propagation of light through samples with random inhomogeneities can be described by way of transmission eigenchannels, which connect incoming and outgoing external propagating modes. Although the detailed structure of a disordered sample can generally not be fully specified, these transmission eigenchannels can nonetheless be successfully controlled and used for focusing and imaging light through random media. Here we demonstrate that in deeply localized quasi-1D systems, the single dominant transmission eigenchannel is formed by an individual Anderson-localized mode or by a ‘necklace state’. In this single-channel regime, the disordered sample can be treated as an effective 1D system with a renormalized localization length, coupled through all the external modes to its surroundings. Using statistical criteria of the single-channel regime and pulsed excitations of the disordered samples allows us to identify long-lived localized modes and short-lived necklace states at long and short time delays, respectively.
The structure and substrate specificity of human Cdk12/Cyclin K
Authors: Bösken Christian A. , Farnung Lucas , Hintermair Corinna , Merzel Schachter Miriam , Vogel-Bachmayr Karin , Blazek Dalibor , Anand Kanchan , Fisher Robert P. , Eick Dirk , Geyer Matthias
Published: March 2014

Phosphorylation of the RNA polymerase II C-terminal domain (CTD) by cyclin-dependent kinases is important for productive transcription. Here we determine the crystal structure of Cdk12/CycK and analyse its requirements for substrate recognition. Active Cdk12/CycK is arranged in an open conformation similar to that of Cdk9/CycT but different from those of cell cycle kinases. Cdk12 contains a C-terminal extension that folds onto the N- and C-terminal lobes thereby contacting the ATP ribose. The interaction is mediated by an HE motif followed by a polybasic cluster that is conserved in transcriptional CDKs. Cdk12/CycK showed the highest activity on a CTD substrate prephosphorylated at position Ser7, whereas the common Lys7 substitution was not recognized. Flavopiridol is most potent towards Cdk12 but was still 10-fold more potent towards Cdk9. T-loop phosphorylation of Cdk12 required coexpression with a Cdk-activating kinase. These results suggest the regulation of Pol II elongation by a relay of transcriptionally active CTD kinases.
Antidepressant-like effects of auraptenol in mice
Authors: Gu Xiaosu , Zhou Yong , Wu Xiaomei , Wang Fen , Zhang Cai-Yi , Du Chenchen , Shen Lihua , Chen Xiang , Shi Jiansheng , Liu Chunfeng , Ke Kaifu
Published: March 2014

Depression is a major psychiatric disorder affecting nearly 21% of the world population and imposes a substantial health burden on society. Current available antidepressants are not adequate to meet the clinical needs. Here we report that auraptenol, an active component of the traditional Chinese medicine, angelicae dahuricae radix, had antidepressant-like effects in mice models of depression. In mouse forced swimming test and tail suspension test, two validated models of depression, auraptenol dose-dependently decreased the immobility duration within the dose range of 0.05–0.4 mg/kg. In addition, the antidepressant-like effects of auraptenol was significantly averted by a selective serotonin 5-HT1A receptor antagonist WAY100635 (1 mg/kg). These doses that affected the immobile response did not affect locomotor activity. In summary, this study for the first time identified an active component from the herbal medicine angelicae dahuricae radix that possesses robust antidepressant-like efficacy in mice. These data support further exploration for the possibility of developing auraptenol as a novel antidepressant agent in the treatment of major depression disorders.
Moyamoya disease-associated protein mysterin/RNF213 is a novel AAA+ ATPase, which dynamically changes its oligomeric state
Authors: Morito Daisuke , Nishikawa Kouki , Hoseki Jun , Kitamura Akira , Kotani Yuri , Kiso Kazumi , Kinjo Masataka , Fujiyoshi Yoshinori , Nagata Kazuhiro
Published: March 2014

Moyamoya disease is an idiopathic human cerebrovascular disorder that is characterized by progressive stenosis and abnormal collateral vessels. We recently identified mysterin/RNF213 as its first susceptibility gene, which encodes a 591-kDa protein containing enzymatically active P-loop ATPase and ubiquitin ligase domains and is involved in proper vascular development in zebrafish. Here we demonstrate that mysterin further contains two tandem AAA+ ATPase modules and forms huge ring-shaped oligomeric complex. AAA+ ATPases are known to generally mediate various biophysical and mechanical processes with the characteristic ring-shaped structure. Fluorescence correlation spectroscopy and biochemical evaluation suggested that mysterin dynamically changes its oligomeric forms through ATP/ADP binding and hydrolysis cycles. Thus, the moyamoya disease-associated gene product is a unique protein that functions as ubiquitin ligase and AAA+ ATPase, which possibly contributes to vascular development through mechanical processes in the cell.
Morphological evolution and toughening mechanism of polypropylene and polypropylene/poly(ethylene-co-octene) alternating multilayered materials with enhanced low-temperature toughness
Authors: Wang Jianfeng , Wang Cuilin , Zhang Xianlong , Wu Hong , Guo Shaoyun
Published: March 2014

In this paper, polypropylene (PP) and polypropylene/poly(ethylene-co-octene) blends (PP/POE) were fabricated into alternating multilayered materials to improve the low-temperature toughness of PP efficiently compared with conventional PP/POE blends.
Ceramic composite separators coated with moisturized ZrO2 nanoparticles for improving the electrochemical performance and thermal stability of lithium ion batteries
Authors: Kim Ki Jae , Kwon Hyuk Kwon , Park Min-Sik , Yim Taeeun , Yu Ji-Sang , Kim Young-Jun
Published: March 2014

Micropore formation around the ZrO2 nanoparticles is caused by the moisture adsorbed on the surface of nanoparticles. This significantly affects the physicochemical properties of the composite separators.
Magnetic scaffolds of polycaprolactone with functionalized magnetite nanoparticles: physicochemical, mechanical, and biological properties effective for bone regeneration
Authors: Kim Jung-Ju , Singh Rajendra K. , Seo Seog-Jin , Kim Tae-Hyun , Kim Joong-Hyun , Lee Eun-Jung , Kim Hae-Won
Published: March 2014

Novel nanocomposite magnetic scaffolds demonstrated excellent bone cell responses.
Template fabricated plasmonic nanoholes on analyte-sensitive substrates for real-time vapor sensing
Authors: Lindquist Nathan C. , Turner Mark A. , Heppner Benjamin P.
Published: March 2014

Plasmonic nanoholes on analyte-sensitive substrates are used for vapor sensing.
Fast fabrication of homogeneous Ag nanostructures on dual-acid doped polyaniline for SERS applications
Authors: Li Siwei , Xiong Lu , Liu Shuai , Xu Ping
Published: March 2014

We demonstrate a dual-acid doping technique for PANI membranes, which enables fast fabrication of homogeneous Ag nanostructures as SERS-active platforms for chemical detection.
Metal control of selectivity in acetate-assisted C–H bond activation: an experimental and computational study of heterocyclic, vinylic and phenylic C(sp2)–H bonds at Ir and Rh
Authors: Carr Kevin J. T. , Davies David L. , Macgregor Stuart A. , Singh Kuldip , Villa-Marcos Barbara
Published: March 2014

Experimental and DFT studies show the selectivity of C–H bond activation at [MCl2Cp*]2 (M = Ir, Rh) species can be controlled by the choice of metal catalyst, reflecting kinetic control at M = Ir and thermodynamic control at M = Rh.
Biocompatible cationic lipids for the formulation of liposomal DNA vectors
Authors: Montis Costanza , Sostegni Silvia , Milani Silvia , Baglioni Piero , Berti Debora
Published: March 2014

Liposomes containing ethylphosphocholine lipids for DNA delivery: phase behavior and interaction with model membranes.
Enhancing photocatalytic activity of disorder-engineered C/TiO2and TiO2nanoparticles
Authors: Wang Shu , Zhao Lei , Bai Lina , Yan Junmin , Jiang Qing , Lian Jianshe
Published: March 2014

This paper summarizes the applications of VOs-induced structural disorders of core-shell C/TiO2and reduced TiO2in improving solar-driven photocatalytic activities.
Fabrication of high-density silver nanoparticles on the surface of alginate microspheres for application in catalytic reaction
Authors: You Jun , Zhao Chengcheng , Cao Jinfeng , Zhou Jinping , Zhang Lina
Published: March 2014

High-density silver nanoparticles immobilized on the surface of alginate microspheres exhibit excellent catalytic activity by reduction of p-nitrophenol.
Modelling IEEE 802.15.6 slotted Aloha in heterogeneous condition
Authors: Chowdhury M.S. , Ashrafuzzaman K. , Kwak K.S.
Published: March 2014

The IEEE 802.15.6 standard for wireless body area network (WBAN) includes a slotted Aloha based protocol as an option for contention based medium access control. This protocol is different from the long studied classical version in that it has inherent considerations for certain priorities of users. An analytical model is presented for saturation throughput with this protocol in a network that is heterogeneous in user priorities. The model is validated against simulation.
Feasible routing selection mechanism in multichannel wireless networks
Authors: Zhang Fan , Cao Yewen
Published: March 2014

Considering more practical scenarios in the designing of joint routing, channel‐assignment and scheduling algorithms in multichannel wireless networks, a modified routing selection scheme based on a performance guaranteed MP mechanism is put forward. The assumption made in MP, that the balance factor chosen for each link αl = α for all links l is not reasonable, is pointed out and may influence the performance of MP badly in the case of channels with large diversity. Focusing on this point, a balance factor used for channel assignment in MP is taken into account in the stage of route selection and the limitation of original MP is relaxed. As a result, the proposed joint algorithm is able to better adapt to the condition of channels with large diversity. It is proved that the modified policy for MP is able to achieve the same capacity region as that of original MP.
Millimetre‐wave end‐fired antenna array for active 3D holographic imaging system
Authors: Fang Weihai , Fei Peng , Nian Feng
Published: March 2014

A compact Ka‐band (26.5–40 GHz) dielectric rod end‐fired antenna array for the three‐dimensional (3D) active holographic imaging system is presented. Without horn shape feeding, the new antenna array is specially designed with characteristics such as small size, high gain, good radiation pattern, easy realisation, low insertion loss and low mutual coupling. In the imaging system, the spacing of sending and receiving antenna units is 1.5 wavelengths with mutual coupling <−30 dB and a gain of 12–16 dB. The results and analysis provide guidelines for the design of millimetre‐wave end‐fired antenna arrays.
Polarisation‐independent wavelength filter using Si wire waveguide Bragg grating and multimode interference couplers
Authors: Okayama H. , Onawa Y. , Shimura D. , Takahashi H. , Miyamura S. , Yaegashi H. , Sasaki H.
Published: March 2014

A wavelength filter using Si wire waveguide Bragg grating and multimode interference couplers is reported. The device is designed for the optical network unit of the fibre to the home system. All the components are designed to achieve polarisation independence.
Impact of partial shading on the output power of PV systems under partial shading conditions
Authors: Balasubramanian Indu Rani , Ilango Ganesan Saravana , Chilakapati Nagamani
Published: March 2014

A major challenge in the photovoltaics (PV) systems is to make it energy efficient. Partial shading reduces the energy yield of PV systems and introduces multiple peaks in the P–V characteristics. The maximum power point trackers (MPPTs) work in conjunction with the boost converter and track the global peak in the P–V characteristics. The boost converter used for MPPT is generally designed to operate with high efficiency at the maximum power point (MPP) voltage of the array by assuming a single peak power point on the P–V characteristics. However, the efficiency of the boost converter varies with the input voltage, and the MPP of the load when the converter efficiency is considered is different from the MPP of the PV array. Since the maximisation of power in the load is ultimately desirable, this study focuses on the maximisation of power to the load. The power transferred to load under different shading patterns is analysed and the results of the study are demonstrated through simulation and experimental results.
Invariants of the electromagnetic field
Authors: Escobar C. A. , Urrutia L. F.
Published: March 2014

We present a constructive proof that, in electrodynamics, all of the gauge-invariant Lorentz scalars and pseudoscalars can be expressed as functions of the quadratic ones.
Absence of bound states for waveguides in two-dimensional periodic structures
Authors: Hoang Vu , Radosz Maria
Published: March 2014

We study a Helmholtz-type spectral problem in a two-dimensional medium consisting of a fully periodic background structure and a perturbation in form of a line defect. The defect is aligned along one of the coordinate axes, periodic in that direction (with the same periodicity as the background), and bounded in the other direction. This setting models a so-called “soft-wall” waveguide problem. We show that there are no bound states, i.e., the spectrum of the operator under study contains no point spectrum.
Observations of thermally excited ferromagnetic resonance on spin torque oscillators having a perpendicularly magnetized free layer
Authors: Tamaru S. , Kubota H. , Yakushiji K. , Konoto M. , Nozaki T. , Fukushima A. , Imamura H. , Taniguchi T. , Arai H. , Tsunegi S. , Yuasa S. , Suzuki Y.
Published: March 2014

Measurements of thermally excited ferromagnetic resonance were performed on spin torque oscillators having a perpendicularly magnetized free layer and in-plane magnetized reference layer (abbreviated as PMF-STO in the following) for the purpose of obtaining magnetic properties in the PMF-STO structure. The measured spectra clearly showed a large main peak and multiple smaller peaks on the high frequency side. A Lorentzian fit on the main peak yielded Gilbert damping factor of 0.0041. The observed peaks moved in proportion to the out-of-plane bias field. From the slope of the main peak frequency as a function of the bias field, Lande g factor was estimated to be about 2.13. The mode intervals showed a clear dependence on the diameter of the PMF-STOs, i.e., intervals are larger for a smaller diameter. These results suggest that the observed peaks should correspond to eigenmodes of lateral spin wave resonance in the perpendicularly magnetized free layer.
Equation-of-motion coupled cluster method for high spin double electron attachment calculations
Authors: Musiał Monika , Lupa Łukasz , Kucharski Stanisław A.
Published: March 2014

The new formulation of the equation-of-motion (EOM) coupled cluster (CC) approach applicable to the calculations of the double electron attachment (DEA) states for the high spin components is proposed. The new EOM equations are derived for the high spin triplet and quintet states. In both cases the new equations are easier to solve but the substantial simplification is observed in the case of quintets. Out of 21 diagrammatic terms contributing to the standard DEA-EOM-CCSDT equations for the R2 and R3 amplitudes only four terms survive contributing to the R3 part. The implemented method has been applied to the calculations of the excited states (singlets, triplets, and quintets) energies of the carbon and silicon atoms and potential energy curves for selected states of the Na2 (triplets) and B2 (quintets) molecules.
Polarized photoluminescence excitation spectroscopy of a-plane InGaN/GaN multiple quantum wells grown on r-plane sapphire
Authors: Kundys D. , Schulz S. , Oehler F. , Sutherland D. , Badcock T. J. , Dawson P. , Kappers M. J. , Oliver R. A. , Humphreys C. J.
Published: March 2014

We have performed a detailed study of the impact of basal plane stacking faults (BSFs) on the optical properties of both a-plane InGaN/GaN quantum wells (QWs) and GaN template samples grown on r-sapphire. In particular, we have used polarised photoluminescence excitation spectroscopy (P-PLE) to investigate the nature of the low temperature recombination as well as extracting information on the valence band (VB) polarisation anisotropy. Our low temperature P-PLE results revealed not only excitons associated with intersubband quantum well transitions and the GaN barrier material but also a transition associated with creation of excitons in BSFs. The strength of this BSF transition varied with detection energy across the quantum well emission suggesting that there is a significant contribution to the emission line width from changes in the local electronic environment of the QWs due to interactions with BSFs. Furthermore, we observed a corresponding progressive increase in the VB splitting of the QWs as the detection energy was varied across the quantum well emission spectrum.
Heat exchangers made of polymer-bonded La(Fe,Si)13
Authors: Skokov K. P. , Karpenkov D. Yu. , Kuz'min M. D. , Radulov I. A. , Gottschall T. , Kaeswurm B. , Fries M. , Gutfleisch O.
Published: March 2014

We report on magnetocaloric properties of polymer-bonded La(Fe,Si)13 heat exchangers with respect to the grain size of the powder used and the pressure applied for compaction of plates. Quite remarkably, it was found that the values of the adiabatic temperature change of polymer-bonded plates are 10% higher than in the initial bulk material. A critical value of the pressure applied during the compaction was found. Exceeding this value leads to a drastic reduction of the magnetocaloric effect due to cracking and comminution of the initial 50–100 μm grains down to 1–10 μm fragments. Compacting the LaFe11.6Si1.4 powder with 5 wt. % of silver epoxy under an optimal pressure of 0.1 GPa resulted in the production of 0.6 mm-thick plates. These plates were subsequently stacked and glued together into a simple porous heat exchanger with straight 0.6 mm-width channels.
Reduced Fokker-Planck models for fast particle distribution across a transition layer of disparate plasma temperatures
Authors: Tang Xian-Zhu , Berk H. L. , Guo Zehua , McDevitt C. J.
Published: March 2014

Across a transition layer of disparate plasma temperatures, the high energy tail of the plasma distribution can have appreciable deviations from the local Maxwellian distribution due to the Knudson layer effect. The Fokker-Planck equation for the tail particle population can be simplified in a series of practically useful limiting cases. The first is the approximation of background Maxwellian distribution for linearizing the collision operator. The second is the supra-thermal particle speed ordering of vTi ≪ v ≪ vTe for the tail ions and vTi ≪ vTe ≪ v for the tail electrons. Keeping both the collisional drag and energy scattering is essential for the collision operator to produce a Maxwellian tail distribution. The Fokker-Planck model for following the tail ion distribution for a given background plasma profile is explicitly worked out for systems of one spatial dimension, in both slab and spherical geometry. A third simplification is an expansion of the tail particle distribution using the spherical harmonics, which are eigenfunctions of the pitch angle scattering operator. This produces a set of coupled Fokker-Planck equations that contain energy-dependent spatial diffusion terms in two coordinates (position and energy), which originate from pitch angle scattering in the original Fokker-Planck equation. It is shown that the well-known diffusive Fokker-Planck model is a poor approximation of the two-mode truncation model, which itself has fundamental deficiency compared with the three-mode truncation model. The cause is the lack of even-symmetry representation in pitch dependence in the two-mode truncation model.
A comparative study of the tail ion distribution with reduced Fokker–Planck models
Authors: McDevitt C. J. , Tang Xian-Zhu , Guo Zehua , Berk H. L.
Published: March 2014

A series of reduced models are used to study the fast ion tail in the vicinity of a transition layer between plasmas at disparate temperatures and densities, which is typical of the gas and pusher interface in inertial confinement fusion targets. Emphasis is placed on utilizing progressively more comprehensive models in order to identify the essential physics for computing the fast ion tail at energies comparable to the Gamow peak. The resulting fast ion tail distribution is subsequently used to compute the fusion reactivity as a function of collisionality and temperature. While a significant reduction of the fusion reactivity in the hot spot compared to the nominal Maxwellian case is present, this reduction is found to be partially recovered by an increase of the fusion reactivity in the neighboring cold region.
Spin-wave based realization of optical computing primitives
Authors: Csaba G. , Papp A. , Porod W.
Published: March 2014

We use micromagnetic simulations to demonstrate that spin waves can perform optically inspired, non-Boolean computing algorithms. We propose and design coherent spin-wave sources and phase shifters, which act akin to the key components of an optical signal processing system. We show that the functionality of the proposed on-chip spin-wave based signal processing system is similar to known optical computing devices. We argue that such computing system can serve as a practical, energy efficient, and integrated component of nanoscale image processing systems.
Communication: The influence of vibrational parity in chiral photoionization dynamics
Authors: Powis Ivan
Published: March 2014

A pronounced vibrational state dependence of photoelectron angular distributions observed in chiral photoionization experiments is explored using a simple, yet realistic, theoretical model based upon the transiently chiral molecule H2O2. The adiabatic approximation is used to separate vibrational and electronic wavefunctions. The full ionization matrix elements are obtained as an average of the electronic dipole matrix elements over the vibrational coordinate, weighted by the product of neutral and ion state vibrational wavefunctions. It is found that the parity of the vibrational Hermite polynomials influences not just the amplitude, but also the phase of the transition matrix elements, and the latter is sufficient, even in the absence of resonant enhancements, to account for enhanced vibrational dependencies in the chiral photoionization dynamics.
Laser sintering of separated and uniformly distributed multiwall carbon nanotubes integrated iron nanocomposites
Authors: Lin Dong , Richard Liu C. , Cheng Gary J.
Published: March 2014

Uniform distribution of carbon nanotubes (CNTs) in metal matrix during additive manufacturing of nanocomposites is always a challenge since the CNTs tend to aggregate in the molten pool. In this study, Multiwall carbon nanotubes (MWNTs) were separated and distributed uniformly into iron matrix by laser sintering process. MWNTs and iron powders were mixed together by magnetic stir, coated on steel 4140 surface, followed by laser sintering. Due to the fast heating and cooling rate, the CNTs are evenly distributed in the metal matrix. The temperature field was calculated by multiphysics simulation considering size effects, including size dependent melting temperature, thermal conductivity, and heat capacity. The SEM, TEM, and XRD were used to understand the laser sintering of CNT integrated nanocomposites. The results proved the feasibility of this technique to synthesize MWNTS integrated metal matrix nanocomposites.
Analysis of single-event upset of magnetic tunnel junction used in spintronic circuits caused by radiation-induced current
Authors: Sakimura N. , Nebashi R. , Natsui M. , Ohno H. , Sugibayashi T. , Hanyu T.
Published: March 2014

This paper describes the possibility of a switching upset of a magnetic tunnel junction (MTJ) caused by a terrestrial radiation-induced single-event-upset (SEU) current in spintronic integrated circuits. The current waveforms were simulated by using a 3-D device simulator in a basic circuit including MTJs designed using 90-nm CMOS parameters and design rules. The waveforms have a 400 -μA peak and a 200-ps elapsed time when neutron particles with a linear energy transfer value of 14 MeV cm2/mg enter the silicon surface. The authors also found that the SEU current may cause soft errors with a probability of more than 10−12 per event, which was obtained by approximate solution of the ordinary differential equation of switching probability when the intrinsic critical current (IC0) became less than 30 μA.
In-situ weak-beam and polarization control of multidimensional laser sidebands for ultrafast optical switching
Authors: Liu Weimin , Wang Liang , Fang Chong
Published: March 2014

All-optical switching has myriad applications in optoelectronics, optical communications, and quantum information technology. To achieve ultrafast optical switching in a compact yet versatile setup, we demonstrate distinct sets of two-dimensional (2D) broadband up-converted multicolor arrays (BUMAs) in a thin type-I β-barium-borate crystal with two noncollinear near-IR femtosecond pulses at various phase-matching conditions. The unique interaction mechanism is revealed as quadratic spatial solitons (QSSs)-coupled cascaded four-wave mixing (CFWM), corroborated by numerical calculations of the governing phase-matching conditions. Broad and continuous spectral-spatial tunability of the 2D BUMAs are achieved by varying the time delay between the two incident pulses that undergo CFWM interaction, rooted in the chirped nature of the weak white light and the QSSs generation of the intense fundamental beam. The control of 2D BUMAs is accomplished via seeding a weak second-harmonic pulse in situ to suppress the 2D arrays with polarization dependence on the femtosecond timescale that matches the control pulse duration of ∼35 fs. A potential application is proposed on femtosecond all-optical switching in an integrated wavelength-time division multiplexing device.
Design of Ionic Liquid-Derived Polyelectrolyte Gels Toward Reversible Water Absorption/Desorption System Driven by Small Temperature Change
Authors: Deguchi Yuki , Kohno Yuki , Ohno Hiroyuki
Published: March 2014

Suitably designed polyelectrolytes derived from tributyl-n-alkylphosphonium 3-sulfopropylmethacrylate-type ionic liquid (IL) monomers undergo a lower critical solution temperature (LCST)-type phase transition, and their transition temperature is a function of the alkyl chain length on the phosphonium cations. Based on this finding, we have successfully prepared chemically cross-linked polyelectrolyte gels, poly(IL) gels, to show the LCST-type phase change. The hydrated state of the prepared poly(IL) gels varied widely with temperature. They desorbed water by elevating the temperature only by a few degrees. Their transition temperature was finely controlled by mixing the composition of IL monomers with different alkyl chain lengths.
Progress towards developing bloat-safe legumes for the farming industry
Authors: Hancock Kerry , Collette Vern , Chapman Elisabeth , Hanson Katherine , Temple Stephen , Moraga Roger , Caradus John
Published: March 2014

Proanthocyanidins (PAs) are polymeric flavonoids derived from the phenylpropanoid pathway, and they bind reversibly to forage proteins within the rumen, providing protection from bloat while enhancing protein utilisation and animal production. The occurrence of PAs varies greatly within forage legume species. Foliar PAs are present in Lotus corniculatus (birdsfoot trefoil) and Onobrychis viciifolia (sainfoin), but such species often show poor persistence under grazing. By contrast, Trifolium repens (white clover) and Medicago sativa (lucerne, or alfalfa) have good persistence but negligible amounts of foliar PAs. We altered the accumulation patterns present in lucerne and white clover by the overexpression of an R2R3-MYB transcription factor (TaMYB14) isolated from T. arvense (rabbit’s foot clover), a species with significant levels of leaf PA. Such plants effectively produced PAs of high degree of polymerisation (DP) in leaf tissue by upregulating genes of the PA pathway. By comparing transcriptome pools, we identified additional MYB transcription factors with putative involvement in PA synthesis in white clover and T. arvense, indicating that these species share a complex PA regulation system. Progress towards producing commercial cultivars of lucerne and white clover containing effective levels of PAs has begun. Such plants will provide a viable option for mitigating bloat in pastoral agriculture-based farming systems.
Eliminating factivity from syntax
Authors: de Cuba Carlos , Ürögdi Barbara
Published: March 2014

This paper contributes to the ongoing discussion on the syntax and semantics of object clauses. Using data from Hungarian and English, we claim that ‘factivity’ is a lexico-semantic concept without a direct correlate in syntax. Instead, we propose that ‘referentiality’ is the feature that differentiates a simple [CP] (the syntactic realization of a proposition) from a more complex [cP[CP]] (encoding a speech act). We support this analysis by looking at the interpretation of sentential embedding constructions and the distribution of clausal expletives in Hungarian. Our account allows us to appeal to the referential property of CP to explain wh-extraction patterns (i.e. the ‘factive island’ effect), as well as syntactic and semantic constraints on wh-expletive constructions.
Narrative as construction and discursive resource
Authors: Taylor Stephanie
Published: March 2014

Discursive psychologists (Edley, 2001; Potter & Wetherell, 1987; Wetherell, 1998) have analysed identity work in talk, including the ways in which understandings which prevail in a wider social context are taken up or resisted as speakers position themselves and are positioned by others. In these terms, a narrative is generally understood in two ways. The first is as an established understanding of sequence or consequence, such as a potential life trajectory, which becomes a discursive resource for speakers to draw on (cf. Bruner’s ‘canonical narratives’, 1991). The second is of a narrative as a situated construction, such as the biography produced by a speaker within a particular interaction. In this article, I propose an expanded analytic focus which considers how the versions of a biographical narrative produced in previous tellings become resources for future talk, thus setting constraints on a reflexive speaker’s work to construct a coherent identity across separate interactions and contexts (Taylor & Littleton, forthcoming).
Caste in and Recasting language
Authors: Prasad G.J.V.
Published: March 2014

This paper considers translation in Tamil as an internal process of changes within the language itself and focuses on how it has negotiated the pressures of the other classical language, accommodating and resisting Sanskrit sounds, words and literary concerns. This negotiation has been influenced by factors that contribute to the power structure—religion, caste and political patronage. Although early in the second millennium there was a movement to write a mixture of Tamil and Sanskrit, Tamil identity has consolidated around the idea of a classical language and culture distinct from that of Sanskrit. This led to repeated purification campaigns, some conducted on clear caste lines. The paper examines how Tamil was translated into a hybrid language and how in turn it has purified itself, especially over the last century.