bluuebunny/crossref_metadata_2025 huggingface dataset:
Encountering climate change: ‘seeing’ is more than ‘believing’
Authors: Reser Joseph P. , Bradley Graham L. , Ellul Michelle C.
Published: May 2014

Individuals' direct exposure to and experience of climate change are arguably integral aspects of their risk perceptions, understandings, and engagement with the issue. Recent research investigating these experiences has thrown into sharp relief some fundamental considerations with respect to public risk perceptions and responses, in particular the extent to which such perceived encounters might reflect a priori beliefs and motivated reasoning. Findings to date are intriguing and compelling, both in regard to the escalating percentages of individuals who report having such personal encounters, and conclusions being drawn with respect to the nature, significance, and influence of such direct experience. These findings have also led to some intuitively reasonable but possibly problematic recommendations regarding policy and issue and behavioural engagement implications. A focus on underlying processes of experience and belief, oversimplified in terms of ‘seeing’ or ‘believing’, has however deflected attention from other issues such as the nature and contexts of individual climate change encounters, the clarity of the constructs and validity of the measures being used for ‘belief’ and ‘experience’, and the transactional and phenomenological nature of climate change encounters. There is nonetheless current and convergent evidence that perceived direct experience of environmental changes or events deemed to be manifestations of climate change influences psychological responses such as risk perception, acceptance, belief certainty, distress, and psychological and behavioural adaptation. These findings suggest that such experiences, for many, foster a contextualized and more personally meaningful realisation of what climate change portends, implies, and ultimately means, locally and globally.

This article is categorized under:

Perceptions, Behavior, and Communication of Climate Change > Perceptions of Climate Change
Synthesis and Surface‐Active Behavior of New Fluorinated Hyperbranched Polymer
Authors: Zhang Yue , Wang Yan , Zhang Huimin , Wang Xi , Zhao Yongxiang , Liu Jun , Wang Feng
Published: May 2014

In this article, a series of novel hyperbranched fluorinated polymer with polyglycerol (PG) as the hydrophilic core and poly(2,2,2‐trifluoroethyl methacrylate) (PTFEMA) as solvophobic arms were synthesized. When the atom transfer radical polymerization was carried out using N,N‐dimethylformamide (DMF) as the solvent, [M]/[I] ratio of 200, and [CuBr]/[NBr] ratio of 0.1 at 30 °C, controlled polymerization was achieved. The surface active properties of the polymer at the dimethyl sulfoxide (DMSO)/air and chloroform/water interface were studied by pendant drop measurements. The results showed that the copolymers could reduce surface tension (interfacial tension) in a manner analogous to the conventional surfactant in aqueous solutions. Thermodynamic analysis suggested that the solvophobic PTFEMA chains play an important role in determining the driving force of the aggregate formation in DMSO.
Performance Management Tools Motivate Change at the Frontlines
Authors: Smith Christopher , Christiansen Tanya , Dick Don , Howden Jane Squire , Wasylak Tracy , Werle Jason
Published: May 2014

Performance management tools commonly used in business, such as incentives and the balanced scorecard, can be effectively applied in the public healthcare sector to improve quality of care. The province of Alberta applied these tools with the Institute for Health Improvement Learning Collaborative method to accelerate adoption of a clinical care pathway for hip and knee replacements. The results showed measurable improvements in all quality dimensions, including shorter hospital stays and wait times, higher bed utilization, earlier patient ambulation, and better patient outcomes.
Créer et maintenir de la valeur: Instaurer une culture d'amélioration continue
Authors: Chattergoon Saleem , Darling Shelley , Devitt Rob , Klassen Wolf
Published: May 2014

En 2011, le Toronto East General Hospital (TEGH) a entrepris de mettre sur pied une culture d'amélioration continue. Il a fini par adopter un système d'amélioration dans l'ensemble de son organisation grâce à son engagement envers la responsabilité financière, l'innovation pratique, la gestion du rendement des équipes et les systèmes de gestion quotidienne. Grâce à cette culture, le TEGH se targue du temps d'attente le moins long du réseau local d'intégration des services de santé à la salle d'urgence pour les patients admis et a réduit de 46 % le séjour hospitalier des patients atteints d'une maladie pulmonaire obstructive chronique.
Computer‐navigated minimally invasive total knee arthroplasty for patients with retained implants in the femur
Authors: Lin Sung‐Yen , Chen Chung‐Hwan , Huang Peng‐Ju , Fu Yin‐Chih , Huang Hsuan‐Ti
Published: May 2014

Total knee arthroplasty (TKA) in patients with knee arthritis and retained implants in the ipsilateral femur is a challenge for knee surgeons. Use of a conventional intramedullary femoral cutting guide is not practical because of the obstruction of the medullary canal by implants. Previous studies have shown that computer‐assisted surgery (CAS) can help restore alignment in conventional TKA for patients with knee arthritis with retained femoral implants or extra‐articular deformity, without the need for implant removal or osteotomy. However, little has been published regarding outcomes with the use of navigation in minimally invasive surgery (MIS)‐TKA for patients with this complex knee arthritis. MIS has been proven to provide less postoperative pain and faster recovery than conventional TKA, but MIS‐TKA in patients with retained femoral implants poses a greater risk in limb malalignment. The purpose of this study is to report the outcome of CAS‐MIS‐TKA in patients with knee arthritis and retained femoral implants. Between April 2006 and March 2008, eight patients with knee arthritis and retained femoral implants who underwent the CAS‐MIS‐TKA were retrospectively reviewed. Three of the eight patients had extra‐articular deformity, including two femur bones and one tibia bone, in the preoperative examination. The anteroposterior, lateral, and long‐leg weight‐bearing radiographs carried out at 3‐month follow‐up was used to determine the mechanical axis of lower limb and the position of components. The mean preoperative femorotibial angle in patients without extra‐articular deformity was 3.8° of varus and was corrected to 4.6° of valgus. With the use of navigation in MIS‐TKA, the two patients in this study with extra‐articular femoral deformity also obtained an ideal postoperative mechanical axis within 2° of normal alignment. Overall, there was a good restoration of postoperative mechanical alignment in all cases, with a mean angle of 0.4° of varus. No limb malalignment or component malposition was found. In clinical assessments, there were also significant improvements in knee specific scores, functional scores, and motion arc. The results of this study suggest that navigation can help achieve accurate alignment and proper prosthesis positioning in MIS‐TKA for patients with retained femoral implants and for whom intramedullary rod guidance is impractical.
The Early Issues of the First Newspaper in Hausa Gaskiya ta fi Kwabo, 1939–1945
Authors: Philips John Edward
Published: May 2014

The first years of Gaskiya ta fi Kwabo, the oldest Hausa newspaper, have recently been made available online for research. They provide a sometimes idiosyncratic perspective on the Second World War.
Using an FFQ to assess intakes of dietary flavonols and flavones among female adolescents in the Suihua area of northern China
Authors: Sun Caihong , Wang Hui , Wang Dong , Chen Yanping , Zhao Yan , Xia Wei
Published: May 2014

Objective

The present study aimed to (i) evaluate the reproducibility and validity of a designed FFQ, (ii) apply the FFQ for estimating the dietary intakes of four flavonols and two flavones in female adolescents and (iii) explain their major dietary sources.

Design

The reproducibility between the first and second FFQ administrations (1 year interval) was estimated using the intra-class correlation coefficient. The validity of the first FFQ relative to the average of four three-day 24 h dietary recalls (24-HR) from four seasons was assessed using the Spearman correlation coefficient. Using a flavonoid content database, the individual flavonol and flavone intakes were calculated and the major food sources were estimated.

Setting

Middle school in Suihua area of Heilongjiang Province, northern China.

Subjects

Female adolescents (n 887) aged 12–18 years.

Results

Better reproducibility and validity were obtained in the present study. The flavonol and flavone intakes were 16·29 and 4·31 mg/d, respectively. Quercetin and kaempferol were the major contributors (26·8 % and 23·7 %, respectively) to the total intake of flavonols and flavones. The main food sources of flavonols and flavones were apples (14·1 %), followed by potatoes (7·5 %), lettuce (7·3 %) and oranges (7·3 %).

Conclusions

The dietary flavonol and flavone intakes among female adolescents in northern China were similar to those reported in several countries, but significant differences were observed in the food sources ascribed to the geographical location and dietary characteristics.
Photosynthetic potential of planets in 3 : 2 spin–orbit resonances
Authors: Brown S.P. , Mead A.J. , Forgan D.H. , Raven J.A. , Cockell C.S.
Published: May 2014

Photosynthetic life requires sufficient photosynthetically active radiation to metabolize. On Earth, plant behaviour, physiology and metabolism are sculpted around the night–day cycle by an endogenous biological circadian clock. The evolution of life was influenced by the Earth–Sun orbital dynamic, which generates the photo-environment incident on the planetary surface. In this work, the unusual photo-environment of an Earth-like planet (ELP) in 3 : 2 spin–orbit resonance is explored. Photo-environments on the ELP are longitudinally differentiated, in addition to differentiations related to latitude and depth (for aquatic organisms) which are familiar on Earth. The light environment on such a planet could be compatible with Earth's photosynthetic life although the threat of atmospheric freeze-out and prolonged periods of darkness would present significant challenges. We emphasize the relationship between the evolution of life on a planetary body with its orbital dynamics.
The Mt John University Observatory search for Earth-mass planets in the habitable zone of α Centauri
Authors: Endl Michael , Bergmann Christoph , Hearnshaw John , Barnes Stuart I. , Wittenmyer Robert A. , Ramm David , Kilmartin Pam , Gunn Fraser , Brogt Erik
Published: May 2014

The ‘holy grail’ in planet hunting is the detection of an Earth-analogue: a planet with similar mass as the Earth and an orbit inside the habitable zone. If we can find such an Earth-analogue around one of the stars in the immediate solar neighbourhood, we could potentially even study it in such great detail to address the question of its potential habitability. Several groups have focused their planet detection efforts on the nearest stars. Our team is currently performing an intensive observing campaign on the α Centauri system using the High Efficiency and Resolution Canterbury University Large Échelle Spectrograph (Hercules)at the 1 m McLellan telescope at Mt John University Observatory in New Zealand. The goal of our project is to obtain such a large number of radial velocity (RV) measurements with sufficiently high temporal sampling to become sensitive to signals of Earth-mass planets in the habitable zones of the two stars in this binary system. Over the past few years, we have collected more than 45 000 spectra for both stars combined. These data are currently processed by an advanced version of our RV reduction pipeline, which eliminates the effect of spectral cross-contamination. Here we present simulations of the expected detection sensitivity to low-mass planets in the habitable zone by theHerculesprogramme for various noise levels. We also discuss our expected sensitivity to the purported Earth-mass planet in a 3.24-day orbit announced by Dumusqueet al.(2012).
Peace operations by proxy: implications for humanitarian action of UN peacekeeping partnerships with non-UN security forces
Authors: Labbé Jérémie , Boutellis Arthur
Published: May 2014

Mandates of United Nations (UN) peacekeeping missions increasingly include stabilisation and peace enforcement components, which imply a proactive use of force often carried out by national, regional or multinational non-UN partners, operating either in support of or with the support of the UN, acting as ‘proxies’. This article analyses the legal, policy and perception/security implications of different types of ‘peace operations by proxy’ and the additional challenges that such operations create for humanitarian action. It suggests some mitigating measures, including opportunities offered by the UN Human Rights Due Diligence Policy, for a more coherent approach to the protection of civilians, but also acknowledges some of the limitations to an independent UN-led humanitarian action.
Triglyceride to high density lipoprotein cholesterol ratio, total cholesterol to high density lipoprotein cholesterol ratio and low ankle brachial index in an elderly population
Authors: Zhan Yiqiang , Yu Jinming , Ding Rongjing , Sun Yihong , Hu Dayi
Published: May 2014

Background: The associations of triglyceride (TG) to high-density lipoprotein cholesterol ratio (HDL‑C) and total cholesterol (TC) to HDL‑C ratio and low ankle brachial index (ABI) were seldom investigated. Patients and methods: A population based cross-sectional survey was conducted and 2982 participants 60 years and over were recruited. TG, TC, HDL‑C, and low-density lipoprotein cholesterol (LDL-C) were assessed in all participants. Low ABI was defined as ABI ≤ 0.9 in either leg. Multiple logistic regression models were applied to study the association between TG/HDL‑C ratio, TC/HDL‑C ratio and low ABI. Results: The TG/HDL‑C ratios for those with ABI > 0.9 and ABI ≤ 0.9 were 1.28 ± 1.20 and 1.48 ± 1.13 (P < 0.0001), while the TC/HDL‑C ratios were 3.96 ± 1.09 and 4.32 ± 1.15 (P < 0.0001), respectively. After adjusting for age, gender, body mass index, obesity, current drinking, physical activity, hypertension, diabetes, lipid-lowering drugs, and cardiovascular disease history, the odds ratios (ORs) with 95 % confidence intervals (CIs) of low ABI for TG/HDL‑C ratio and TC/HDL‑C ratio were 1.10 (0.96, 1.26) and 1.34 (1.14, 1.59) in non-smokers. When TC was further adjusted, the ORs (95 % CIs) were 1.40 (0.79, 2.52) and 1.53 (1.21, 1.93) for TG/HDL‑C ratio and TC/HDL‑C ratio, respectively. Non-linear relationships were detected between TG/HDL‑C ratio and TC/HDL‑C ratio and low ABI in both smokers and non-smokers. Conclusions: TC/HDL‑C ratio was significantly associated with low ABI in non-smokers and the association was independent of TC, TG, HDL‑C, and LDL-C. TC/HDL‑C might be considered as a potential biomarker for early peripheral arterial disease screening.
Ankle brachial index and pneumoplethysmographic pulse-volume recordings for detection of peripheral arterial disease
Authors: Jahn Jürgen , Zimmermann Werner , Moysidis Theodoros , Kröger Knut
Published: May 2014

Background: The measurement of the ankle-brachial index (ABI) is a straightforward method for the detection of atherosclerosis in the lower limbs. Pneumoplethysmographic pulse-volume recordings (PVR) investigations are supposed to be less valid. Thus we compared the sensitivity of ABI and PVR in detection of PAD and its improvement by combining both methods. Patients and methods: 122 consecutive patients admitted for PAD treatment were included. All patients (81 females; mean age 70 ± 15 years) had angiographic imaging of their peripheral arteries, a standardized personal interview and a determination of the ABI based on the highest (ABI high) and lowest (ABI low) ankle pressure. PVR parameters were oscillometric index (OI) and time to normalisation (TN) after exercise. Results: There was a small variation of ABI with different segmental manifestations of PAD. The OI did not vary with different segmental manifestations. TN was longest in iliac artery manifestation and got shorter with more distal manifestation. Correlation of TN and ABI high and ABI low was low. Sensitivity of ABI high in all legs was 78 %, but only 40 % in isolated crural manifestation. ABI low has higher sensitivities with 87 % in all legs, but a much lower specificity. Combining ABI and TN increases both sensitivity and specificity. The best sensitivity and specificity was seen using ABI low + TN in combination in all kinds of manifestations with 94 % and 96 %, respectively. Conclusions: Combined assessment of ABI low and TN in post-exercise PVR seems to be a highly sensitive but also specific method to look for PAD compared to ABI high alone.
Treatment options of crural pseudoaneurysms
Authors: Gratl Alexandra , Klocker Josef , Glodny Bernhard , Wick Marius , Fraedrich Gustav
Published: May 2014

Background: Pseudoaneurysms (PAs) of crural arteries represent rare complications of vascular interventions or surgery. Management of crural PAs includes different treatment options, conservative treatment as well as open surgery or endovascular procedures. We reviewed our experience. Patients and methods: We retrospectively analysed all patients who were diagnosed with crural PAs since 2003. We evaluated etiology, treatment and outcome. Endpoints were target vessel patency, vascular re-intervention and limb loss. Results: A total of 30 patients were diagnosed with crural PAs. PA was caused by vascular intervention in 27 patients (90 %): open balloon thrombectomy (n = 25), subfascial endoscopic perforator vein surgery (n = 1) and transcutaneous catheter-assisted thrombus aspiration (n = 1). In 3 patients (10 %) it was caused by orthopaedic surgical procedures. Location of crural PAs were peroneal artery (n = 11; 36.7 %), posterior tibial artery (n = 10; 33.3 %), anterior tibial artery (n = 5; 16.7 %), and tibioperoneal trunk (n = 4; 13.3 %). Treatment of crural PAs included open surgery (n = 3; 10 %), endovascular procedures (n = 13; 43.3 %) such as endograft implantation (n = 9) or coil embolisation (n = 4), and conservative management (n = 14; 46.7 %). After a median follow-up period of 7 months (range: 0 - 46 months) 8 of 9 endografts were occluded, in none of these patients a minor or a major amputation was necessary. None of the surgically, endovascularly and conservatively treated patients needed a re-intervention for crural PA. A major amputation was necessary in 4 patients due to progression of peripheral arterial disease; none was a directly consequence of the crural PA. Conclusions: Crural PAs are mainly caused by vascular intervention, most frequently by catheter thrombectomy. As a consequence, we recommend fluoroscopic-assisted balloon thrombectomy over a guide wire as routine technique. In many cases of crural PAs, conservative management is sufficient. The choice of treatment of crural PAs depends on size, location and associated symptoms. Endovascular treatment using endografts is limited by poor long-term patency.
Phorbol myristate acetate, but not CD40L, induces the differentiation of CLL B cells into Ab‐secreting cells
Authors: Ghamlouch Hussein , Ouled‐Haddou Hakim , Guyart Aude , Regnier Aline , Trudel Stéphanie , Claisse Jean‐François , Fuentes Vincent , Royer Bruno , Marolleau Jean‐Pierre , Gubler Brigitte
Published: May 2014

In this study, we investigated the capacity of chronic lymphocytic leukemia (CLL) B cells to undergo terminal differentiation into Ig‐secreting plasma cells in T cell‐independent and T cell‐dependent responses. We used a two‐step model involving stimulation with phorbol myristate acetate (PMA) and CD40L, together with cytokines (PMA/c and CD40L/c), for 7 days. We describe immunophenotypic modifications, changes in the levels of mRNA and protein for transcription factors and morphological and functional events occurring during the differentiation of CLL B cells into antibody‐secreting cells (ASCs). The induction of differentiation differed significantly between the CD40L/c and PMA/c culture systems. The PMA/c culture system allowed CLL B cells to differentiate into IgM‐secreting cells with an immunophenotype and molecular profile resembling those of preplasmablasts. By contrast, CD40L/c‐stimulated cells had a phenotype and morphology similar to those of activated B cells and resembling those of the CLL B cells residing in the lymph node and bone marrow. These data suggest that the CLL B cells are not frozen permanently at a stage of differentiation and are able to differentiate into ASCs as appropriate stimulation are provided. The data presented here raise questions about the molecular processes and stimulation required for CLL B‐cell differentiation and about the inability of CD40 ligand to induce differentiation of the CLL B cells.
Multiple metabolomics of uropathogenic E. coli reveal different information content in terms of metabolic potential compared to virulence factors
Authors: AlRabiah Haitham , Xu Yun , Rattray Nicholas J. W. , Vaughan Andrew A. , Gibreel Tarek , Sayqal Ali , Upton Mathew , Allwood J. William , Goodacre Royston
Published: May 2014

No single analytical method can cover the whole metabolome and the choice of which platform to use may inadvertently introduce chemical selectivity.
Fabrication of lipophilic gold nanoparticles for studying lipids by surface enhanced Raman spectroscopy (SERS)
Authors: Driver Michael , Li Yue , Zheng Jinkai , Decker Eric , Julian McClements David , He Lili
Published: May 2014

A simple fabrication method for preparing lipophilic gold nanoparticles (AuNPs) suitable for use as substrates in surface-enhanced Raman scattering (SERS) applications of lipids was developed.
Chiral separation of ten arylphenoxypropionate herbicides on four chiral columns by supercritical fluid chromatography
Authors: Yang Xue , Ma Binbin , Zheng Xiaqiong , Lin Chunmian
Published: May 2014

Many chemical products used in the agrochemical industries contain chiral centers and consist of one or two pairs of enantiomers, which can have important consequences regarding bioactivity.
Determination of sesamol in sesame oil by anion exchange solid phase extraction coupled with HPLC
Authors: Sun Weihong , Xiao Ronghui
Published: May 2014

A novel, sensitive and reliable anion exchange SPE procedure method for cleanup and extraction of sesamol in sesame oil was developed.
Amplified electrochemiluminescence of lucigenin triggered by electrochemically reduced graphene oxide and its sensitive detection of bisphenol A
Authors: Dai Hong , Zhang Shupei , Lin Yanyu , Ma Yan , Gong Lingshan , Xu Guifang , Fu Mei , Li Xiuhua , Chen Guonan
Published: May 2014

An amplified and stable electrochemiluminescent signal of lucigenin on electrochemically reduced graphene oxide-containing sensing platform was obtained, and exhibited obvious analytical properties towards bisphenol A.
A rational approach for generating cardiac troponin I selective Spiegelmers
Authors: Szeitner Zsuzsanna , Lautner Gergely , Nagy Szilvia K. , Gyurcsányi Róbert E. , Mészáros Tamás
Published: May 2014

We report the first protein selective Spiegelmers of diagnostic relevance by rational identification of a target epitope and reverse screening of Spiegelmer candidates following the selection procedure.
Self-organized cobalt fluoride nanochannel layers used as a pseudocapacitor material
Authors: Lee Chong-Yong , Su Zixue , Lee Kiyoung , Tsuchiya Hiroaki , Schmuki Patrik
Published: May 2014

Aligned CoF2 nanochannel layers were synthesized by self-ordering anodization. These layers show an almost ideal rectangular pseudocapacitive behavior, and may thus be promising for supercapacitor applications.
Membrane-mediated cascade reactions by enzyme–polymer proteinosomes
Authors: Huang Xin , Li Mei , Mann Stephen
Published: May 2014

Proteinosomes comprising a triad of enzyme–polymer amphiphilic building blocks capable of operating together as a multi-step membrane-mediated cascade system are prepared and characterized.
Dihydrothiophenes containing quaternary stereogenic centres by sequential stereospecific rearrangements and ring-closing metathesis
Authors: Mingat Gaëlle , McDouall Joseph J. W. , Clayden Jonathan
Published: May 2014

Tandem stereospecific rearrangements by [3,3]-sigmatropic shift and N to C aryl migration give tertiary thiols that undergo ring closing metathesis to dihydrothiophenes.
Synthesis of hollow rare-earth compound nanoparticles by a universal sacrificial template method
Authors: Jia Yue , Sun Tian-Ying , Wang Jia-Hong , Huang Hao , Li Penghui , Yu Xue-Feng , Chu Paul K.
Published: May 2014

A universal sacrificial-template method to synthesize hollow structured materials with fluorescence properties.
A structural framework of biologically active coumarin derivatives: crystal structure and Hirshfeld surface analysis
Authors: Małecka Magdalena , Budzisz Elzbieta
Published: May 2014

The relation between the lipophilicity parameter (log P) and the contribution of C–H⋯π interactions to the Hirshfeld surface has been investigated.
Substituent effect on the formation of helical to layered hydrogen bond networks in hydroxyl and carboxyl substituted 1-aryl-1H-1,2,3-triazoles
Authors: Sureshbabu Bemineni , Venkatachalam Ramkumar , Sankararaman Sethuraman
Published: May 2014

Interplay of twisted conformations and O–H⋯N and O–H⋯O hydrogen bond synthons on supramolecular chirality in OH and COOH substituted 1-aryl-1H-1,2,3-triazoles.
Non-innocent side-chains with dipole moments in organic solar cells improve charge separation
Authors: de Gier Hilde D. , Broer Ria , Havenith Remco W. A.
Published: May 2014

Polymer side-chains with dipole moments are electronically not innocent spectators, but exert electronic effects that could facilitate charge separation.
Direct amination of benzene to aniline with H2O2 and NH3·H2O over Cu/SiO2 catalyst
Authors: Yu Tianhua , Yang Ruiguang , Xia Sheng , Li Guiying , Hu Changwei
Published: May 2014

Cu/S-1 catalyst activated the N–H bond of NH3 and C–H bond of benzene leading to the formation of aniline.
Semi-catalytic reduction of secondary amides to imines and aldehydes
Authors: Lee Sun-Hwa , Nikonov Georgii I.
Published: May 2014

Ruthenium catalyzed reduction of iminoyl chlorides by HSiMe2Ph allows for a two-step conversion of secondary amides into imines and aldehydes.
StyletChip: a microfluidic device for recording host invasion behaviour and feeding of plant parasitic nematodes
Authors: Hu Chunxiao , Kearn James , Urwin Peter , Lilley Catherine , O' Connor Vincent , Holden-Dye Lindy , Morgan Hywel
Published: May 2014

StyletChip electrophysiologically records activity of the stylet, a lance-like structure which protrudes from the mouth (position indicated by red arrow) of plant parasitic nematodes and which is integral to parasitic behaviour.
Tessellated gold nanostructures from Au144(SCH2CH2Ph)60 molecular precursors and their use in organic solar cell enhancement
Authors: Bauld Reg , Hesari Mahdi , Workentin Mark S. , Fanchini Giovanni
Published: May 2014

Two solar cell architectures fabricated utilizing gold nanoparticles (AuNPs) in PEDOT:PSS. Tessellated AuNPs (Tess-AuNPs) enhance the power conversion efficiency of 10% relative to a control cell.
Reversible metallisation of soft UV patterned substrates
Authors: Prompinit Panida , Achalkumar Ammathnadu S. , Walton Alexander S. , Bushby Richard J. , Wälti Christoph , Evans Stephen D.
Published: May 2014

Patterned surface created through soft UV (365 nm) patterning of ortho-nitrobenzyl functionalized thiol-on-gold self-assembled monolayers (SAMs) is suitable for electro-deposition with high selectivity and fully reversibility of deposition/stripping process.
Talker Identification Across Source Mechanisms: Experiments With Laryngeal and Electrolarynx Speech
Authors: Perrachione Tyler K. , Stepp Cara E. , Hillman Robert E. , Wong Patrick C. M.
Published: May 2014

Purpose

The purpose of this study was to determine listeners' ability to learn talker identity from speech produced with an electrolarynx, explore source and filter differentiation in talker identification, and describe acoustic-phonetic changes associated with electrolarynx use.

Method

Healthy adult control listeners learned to identify talkers from speech recordings produced using talkers' normal laryngeal vocal source or an electrolarynx. Listeners' abilities to identify talkers from the trained vocal source (Experiment 1) and generalize this knowledge to the untrained source (Experiment 2) were assessed. Acoustic-phonetic measurements of spectral differences between source mechanisms were performed. Additional listeners attempted to match recordings from different source mechanisms to a single talker (Experiment 3).

Results

Listeners successfully learned talker identity from electrolarynx speech but less accurately than from laryngeal speech. Listeners were unable to generalize talker identity to the untrained source mechanism. Electrolarynx use resulted in vowels with higher F1 frequencies compared with laryngeal speech. Listeners matched recordings from different sources to a single talker better than chance.

Conclusions

Electrolarynx speech, although lacking individual differences in voice quality, nevertheless conveys sufficient indexical information related to the vocal filter and articulation for listeners to identify individual talkers. Psychologically, perception of talker identity arises from a “gestalt” of the vocal source and filter.
Kolmogorov spectrum consistent optimization for multi-scale flow decomposition
Authors: Mishra M. , Liu X. , Skote M. , Fu C.-W.
Published: May 2014

Multi-scale analysis is widely adopted in turbulence research for studying flow structures corresponding to specific length scales in the Kolmogorov spectrum. In the present work, a new methodology based on novel optimization techniques for scale decomposition is introduced, which leads to a bandpass filter with prescribed properties. With this filter, we can efficiently perform scale decomposition using Fourier transform directly while adequately suppressing Gibbs ringing artifacts. Both 2D and 3D scale decomposition results are presented, together with qualitative and quantitative analysis. The comparison with existing multi-scale analysis technique is conducted to verify the effectiveness of our method. Validation of this decomposition technique is demonstrated both qualitatively and quantitatively. The advantage of the proposed methodology enables a precise specification of continuous length scales while preserving the original structures. These unique features of the proposed methodology may provide future insights into the evolution of turbulent flow structures.
Mixed quantum classical calculation of proton transfer reaction rates: From deep tunneling to over the barrier regimes
Authors: Xie Weiwei , Xu Yang , Zhu Lili , Shi Qiang
Published: May 2014

We present mixed quantum classical calculations of the proton transfer (PT) reaction rates represented by a double well system coupled to a dissipative bath. The rate constants are calculated within the so called nontraditional view of the PT reaction, where the proton motion is quantized and the solvent polarization is used as the reaction coordinate. Quantization of the proton degree of freedom results in a problem of non-adiabatic dynamics. By employing the reactive flux formulation of the rate constant, the initial sampling starts from the transition state defined using the collective reaction coordinate. Dynamics of the collective reaction coordinate is treated classically as over damped diffusive motion, for which the equation of motion can be derived using the path integral, or the mixed quantum classical Liouville equation methods. The calculated mixed quantum classical rate constants agree well with the results from the numerically exact hierarchical equation of motion approach for a broad range of model parameters. Moreover, we are able to obtain contributions from each vibrational state to the total reaction rate, which helps to understand the reaction mechanism from the deep tunneling to over the barrier regimes. The numerical results are also compared with those from existing approximate theories based on calculations of the non-adiabatic transmission coefficients. It is found that the two-surface Landau-Zener formula works well in calculating the transmission coefficients in the deep tunneling regime, where the crossing point between the two lowest vibrational states dominates the total reaction rate. When multiple vibrational levels are involved, including additional crossing points on the free energy surfaces is important to obtain the correct reaction rate using the Landau-Zener formula.
Effects of dimensionality and spatial distribution on the magnetic relaxation of interacting ferromagnetic nanoclusters: A Monte Carlo study
Authors: Brinis D. , Laggoun A. , Ledue D. , Patte R.
Published: May 2014

The magnetization dynamics of one- or two-dimensional self-organized assemblies of interacting nanoclusters, which are potential candidates for ultra-high density magnetic recording media, was investigated using Monte Carlo simulations. The study was focused on the temperature variation of the ac-susceptibility as well as the decay over time of the magnetization of cobalt nanoparticles having the same anisotropy axis. Evidence was found of significant dipolar interaction effects on the peak position of the imaginary part of the ac-susceptibility and on the relaxation time due to the common easy axis and the low-dimensionality of the assemblies even for low concentration (less than 10%). With increasing the strength of the dipolar interactions, the peak of the out-of-phase component shifts towards higher or lower temperatures depending on whether the magnetic moments are oriented in the plane assembly or perpendicular to it. A peak shift towards higher (lower) temperatures is clearly linked to an increase (decrease) of the relaxation time. The relaxation time in the presence of dipolar interactions still follows an Arrhenius law with an effective energy barrier which is either larger or smaller than the anisotropy energy barrier. It is also shown that random positions slightly strengthen the influence of dipolar interactions.
Comparison between kinetic-ballooning-mode-driven turbulence and ion-temperature-gradient-driven turbulence
Authors: Maeyama S. , Ishizawa A. , Watanabe T.-H. , Nakata M. , Miyato N. , Yagi M. , Idomura Y.
Published: May 2014

Electromagnetic turbulence driven by kinetic ballooning modes (KBMs) in high-β plasma is investigated based on the local gyrokinetic model. Analysis of turbulent fluxes, norms, and phases of fluctuations shows that KBM turbulence gives narrower spectra and smaller phase factors than those in ion-temperature-gradient (ITG)-driven turbulence. This leads to the smaller transport fluxes in KBM turbulence than those in ITG turbulence even when they have similar linear growth rates. From the analysis of the entropy balance relation, it is found that the entropy transfer from ions to electrons through the field-particle interactions mainly drives electron perturbations, which creates radial twisted modes by rapid parallel motions of electrons in a sheared magnetic geometry. The nonlinear coupling between the dominant unstable mode and its twisted modes is important for the saturation of KBM turbulence, in contrast to the importance of zonal flow shearing in ITG turbulence. The coupling depends on the flux-tube domain with the one-poloidal-turn parallel length and on the torus periodicity constraint.
Indirect-direct band gap transition through electric tuning in bilayer MoS2
Authors: Zhang Z. Y. , Si M. S. , Wang Y. H. , Gao X. P. , Sung Dongchul , Hong Suklyun , He Junjie
Published: May 2014

We investigate the electronic properties of bilayer MoS2 exposed to an external electric field by using first-principles calculations. It is found that a larger interlayer distance, referring to that by standard density functional theory (DFT) with respect to that by DFT with empirical dispersion corrections, makes indirect-direct band gap transition possible by electric control. We show that external electric field effectively manipulates the valence band contrast between the K- and Γ-valleys by forming built-in electric dipole fields, which realizes an indirect-direct transition before a semiconductor-metal transition happens. Our results provide a novel efficient access to tune the electronic properties of two-dimensional layered materials.
Fluid flow and scalar transport through porous fins
Authors: Coletti F. , Muramatsu K. , Schiavazzi D. , Elkins C. J. , Eaton J. K.
Published: May 2014

Lotus-type porous metals are a promising alternative for compact heat transfer applications. In lotus-type porous fins, jet impingement and transverse mixing play important roles for heat transfer: jets emerging from the pores impinge on the following fin and enhance heat transfer performance, while the transverse fluid motion advects heat away from the fin surface. By means of magnetic resonance imaging we have performed mean flow and scalar transport measurements through scaled-up replicas of two kinds of lotus-type porous fins: one with a deterministic hole pattern and staggered alignment, and one with a random hole pattern, but the same porosity and mean pore diameter. The choice of geometric parameters (fin spacing, thickness, porosity, and hole diameter) is based on previous thermal studies. The Reynolds number based on the mean pore diameter and inner velocity ranges from 80 to 3800. The measurements show that in the random hole pattern the jet characteristic length scale is substantially larger with respect to the staggered hole pattern. The random geometry also produces long coherent vortices aligned with the streamwise direction, which improves the transverse mixing. The random hole distribution causes the time mean streamlines to meander in a random-walk manner, and the diffusivity coefficient associated to the mechanical dispersion (which is nominally zero in the staggered hole configuration) is several times larger than the fluid molecular diffusivity at the higher Reynolds numbers. From the trends in maximum streamwise velocity, streamwise vorticity, and mechanical diffusivity, it is inferred that the flow undergoes a transition to an unsteady/turbulent regime around Reynolds number 300. This is supported by the measurements of concentration of an isokinetic non-buoyant plume of scalar injected upstream of the stack of fins. The total scalar diffusivity for the fully turbulent regime is found to be 22 times larger than the molecular diffusivity, but only 6 times higher than the mechanical diffusivity, indicating that the latter plays a significant role for heat transfer and mixing.
The direct enstrophy cascade of two-dimensional soap film flows
Authors: Rivera M. K. , Aluie H. , Ecke R. E.
Published: May 2014

We investigate the direct enstrophy cascade of two-dimensional decaying turbulence in a flowing soap film channel. We use a coarse-graining approach that allows us to resolve the nonlinear dynamics and scale-coupling simultaneously in space and in scale. From our data, we verify an exact relation due to Eyink [“Local energy flux and the refined similarity hypothesis,” J. Stat. Phys. 78, 335–351 (1995); Eyink “Exact results on scaling exponents in the 2D enstrophy cascade,” Phys. Rev. Lett. 74, 3800–3803 (1995)] between traditional 3rd-order structure function and the enstrophy flux obtained by coarse-graining. We also present experimental evidence that enstrophy cascades to smaller (larger) scales with a 60% (40%) probability, in support of theoretical predictions by Merilees and Warn [“On energy and enstrophy exchanges in two-dimensional non-divergent flow,” J. Fluid Mech. 69, 625–630 (1975)] which appear to be valid in our flow owing to the ergodic nature of turbulence. We conjecture that their kinematic arguments break down in quasi-laminar 2D flows. We find some support for these ideas by using an Eulerian coherent structure identification technique, which allows us to determine the effect of flow topology on the enstrophy cascade. A key finding is that “centers” are inefficient at transferring enstrophy between scales, in contrast to “saddle” regions which transfer enstrophy to small scales with high efficiency.
Compact bubble clusters in Newtonian and non-Newtonian liquids
Authors: Vélez-Cordero J. Rodrigo , Lantenet Johanna , Hernández-Cordero Juan , Zenit Roberto
Published: May 2014

We studied the terminal velocity of a packed array of bubbles, a bubble cluster, rising in different fluids: a Newtonian fluid, an elastic fluid with nearly constant viscosity (Boger fluid), and a viscoelastic fluid with a shear dependent viscosity, for small but finite Reynolds numbers (1 × 10−4 < Re < 4). In all three cases, the cluster velocity increased with the total volume, following the same trend as single bubbles. For the case of clusters in elastic fluids, interestingly, the so-called velocity discontinuity was not observed, unlike the single bubble case. In addition to the absence of jump velocity, the clusters did not show the typical teardrop shape of large bubbles in viscoelastic fluids and the strength of the negative wake is much weaker than the one observed behind single bubbles. Dimensional analysis of the volume-velocity plots allowed us to show that, while the equivalent diameter (obtained from the total cluster volume) is the appropriate length to determine buoyancy forces and characteristic shear rates, the individual bubble size is the appropriate scale to account for surface forces.
Thermal conductivity of high performance carbon nanotube yarn-like fibers
Authors: Mayhew Eric , Prakash Vikas
Published: May 2014

In the present paper, we present results of thermal conductivity measurements in free standing carbon nanotube (CNT) yarn-like fibers. The measurements are made using a T-type experimental configuration utilizing a Wollaston-wire hot probe inside a scanning electron microscope. In this technique, a suspended platinum wire is used both as a heater and a thermal sensor. A low frequency alternating current source is used to heat the probe wire while the third harmonic voltage across the wire is measured by a lock-in amplifier. The conductivity is deduced from an analytical model that relates the drop in the spatially averaged temperature of the wire to that of the sample. The average thermal conductivity of the neat CNT fibers and the CNT –polymer composite fibers is found to be 448 W/m-K and 225 W/m-K, respectively. These values for conductivity are amongst the highest measured for CNT yarn-like fibers fabricated using a dry spinning process from vertically aligned CNT arrays. The enhancement in thermal conductivity is understood to be due to an increase in the CNT fiber elastic stiffness during the draw and twist operations, lower CNT thermal contact resistance due to increase in CNT contact area, and better alignment of the CNT fibrils along the length of the fiber.
Nanoscale transport of phonons: Dimensionality, subdiffusion, molecular damping, and interference effects
Authors: Walczak Kamil , Yerkes Kirk L.
Published: May 2014

We examine heat transport carried by acoustic phonons in the systems composed of nanoscale chains of masses coupled to two thermal baths of different temperatures. Thermal conductance is obtained by using linearized Landauer-type formula for heat flux with phonon transmission probability calculated within atomistic Green's functions (AGF) method. AGF formalism is extended onto dissipative chains of masses with harmonic coupling beyond nearest-neighbor approximation, while atomistic description of heat reservoirs is also included into computational scheme. In particular, the phonon lifetimes and the phonon frequency shifts are discussed for harmonic lattices of different dimensions. Further, resonant structure of phonon transmission spectrum is analyzed with respect to reservoir-induced effects, molecular damping, and mass-to-mass harmonic coupling. Analysis of transmission zeros (antiresonances) and their accompanied Fano-shape resonances are discussed as a result of interference effects between different vibrational modes. Finally, we also predict subdiffusive transport regime for low-frequency ballistic phonons propagated along a linear chain of harmonically coupled masses.
Electric field control of spin-resolved edge states in graphene quantum nanorings
Authors: Farghadan R. , Saffarzadeh A.
Published: May 2014

The electric-field effect on the electronic and magnetic properties of triangular and hexagonal graphene quantum rings with zigzag edge termination is investigated by means of the single-band tight-binding Hamiltonian and the mean-field Hubbard model. It is shown how the electron and spin states in the nanoring structures can be manipulated by applying an electric field. We find different spin-depolarization behaviors with variation of electric field strength due to the dependence of spin densities on the shapes and edges of this kind of nanorings. In the case of triangular quantum rings, the magnetization on the inner and outer edges can be selectively tuned and the spin states depolarize gradually as the field strength is increased, while in the case of hexagonal nanorings, the transverse electric field reduces the magnetic moments on both inner and outer edges symmetrically and rapidly.
Bipolar and unipolar resistive switching modes in Pt/Zn0.99Zr0.01O/Pt structure for multi-bit resistance random access memory
Authors: Xu D. L. , Xiong Y. , Tang M. H. , Zeng B. W. , Xiao Y. G.
Published: May 2014

In this work, we report the coexistence of bipolar resistive switching (BRS) and unipolar resistive switching (URS) modes in Pt/Zn0.99Zr0.01O/Pt structure device. After the forming process, this device with URS behavior exhibits either URS mode in the same direction or BRS mode in the opposite direction during the reset process. Controllable multi-state resistances in the low and high resistance states for the BRS mode were obtained by imposing different compliance currents (Icc) and the span of voltage sweeping in the reset process (Vstop). These results suggest that our devices have high potential for the next generation of nonvolatile memory applications.
Identification of dominant scattering mechanism in epitaxial graphene on SiC
Authors: Lin Jingjing , Guo Liwei , Jia Yuping , Yang Rong , Wu Shuang , Huang Jiao , Guo Yu , Li Zhilin , Zhang Guangyu , Chen Xiaolong
Published: May 2014

A scheme of identification of scattering mechanisms in epitaxial graphene (EG) on SiC substrate is developed and applied to three EG samples grown on SiC (0001), (112¯0), and (101¯0) substrates. Hall measurements combined with defect detection technique enable us to evaluate the individual contributions to the carrier scatterings by defects and by substrates. It is found that the dominant scatterings can be due to either substrate or defects, dependent on the substrate orientations. The EG on SiC (112¯0) exhibits a better control over the two major scattering mechanisms and achieves the highest mobility even with a high carrier concentration, promising for high performance graphene-based electronic devices. The method developed here will shed light on major aspects in governing carrier transport in EG to harness it effectively.