bluuebunny/crossref_metadata_2025 huggingface dataset:
Naturally occurring phenolic sources: monomers and polymers
Authors: Lochab Bimlesh , Shukla Swapnil , Varma Indra K.
Published: March 2014

Phenolic compounds sourced from agro-based feedstock, viz. cashew nut shell liquid, lignin, tannin, palm oil, and coconut shell tar, have come up as sustainable alternatives to petro-based feedstock. This review explores their utility as green polymer feedstock with citation of ~ 600 references.
Microfluidic solvent extraction and separation of cobalt and nickel
Authors: Zhang Li-hua , Peng Jin-hui , Ju Shao-hua , Zhang Li-bo , Dai Lin-qing , Liu Neng-sheng
Published: March 2014

The extraction and separation of cobalt from sulphate solution containing Ni2+ and Co2+ by the process of microfluidic extraction was investigated on a counter-current flow interdigital micromixer with channels of 40 μm width, which has two opposite inlets and an upwards outlet.
Progress of 3-aminopyridinium-based synthetic receptors in anion recognition
Authors: Ghosh Kumaresh , Sarkar Avik Ranjan , Sarkar Tanmay , Panja Santanu , Kar Debasis
Published: March 2014

This review describes the overall development on synthetic receptors built on the pyridinium motif with different functionalities at the 3-position in anion recognition.
High-modulus all-carbon ladder polymer of hydroquinone and formaldehyde that bridges the gap between single-strand polymers and graphene nanoribbons
Authors: Zeng Shao-Zhong , Jin Neng-Zhi , Zhang Hai-Lu , Hai Bin , Chen Xiao-Hua , Shi Jianlin
Published: March 2014

An all-carbon ladder polymer with high modulus and high structural similarities to graphene nanoribbons is synthesized by a facile one-pot method.
A photonic crystal-based CdS–Au–WO3 heterostructure for efficient visible-light photocatalytic hydrogen and oxygen evolution
Authors: Cui Xiaofeng , Wang Yajun , Jiang Guiyuan , Zhao Zhen , Xu Chunming , Wei Yuechang , Duan Aijun , Liu Jian , Gao Jinsen
Published: March 2014

Photonic crystal-based CdS–Au–WO3 heterostructure that integrates slow photon effect and superior electron transfer exhibits efficient photocatalytic H2 and O2 evolution.
Facile method to synthesize silver nanoparticles on the surface of hollow glass microspheres and their microwave shielding properties
Authors: Huang Zheng , Chi Bo , Guan Jianguo , Liu Yaqing
Published: March 2014

In this paper, a facile method for the fabrication of hollow glass microspheres–Ag composite particles with core–shell structures is investigated.
Determination of sodium sulfide based on electrochemiluminescence of rhodamine B at a SWNT modified glassy carbon electrode
Authors: Liu Fengyu , Gao Yulong , Li Wei , Shao Jiantao , Meng Yang
Published: March 2014

Rhodamine B (RhB) was covalently linked with SWNTs through different linkages and modified on a glassy carbon (GC) electrode to detect sodium sulfide with good reproducibility and stability.
Precision polymers: a kinetic approach for functional poly(norbornenes)
Authors: Moatsou Dafni , Hansell Claire F. , O'Reilly Rachel K.
Published: March 2014

Control over monomer sequence in the ring-opening metathesis polymerization of functional norbornenes is explored based on the difference in reactivity of endo and exo isomers.
Alluaudite LiMnPO4: a new Mn-based positive electrode for Li rechargeable batteries
Authors: Kim Jongsoon , Kim Hyungsub , Park Kyu-Young , Park Young-Uk , Lee Seongsu , Kwon Hyung-Soon , Yoo Han-Ill , Kang Kisuk
Published: March 2014

A novel, Na-pillared LiMnPO4 with an alluaudite structure that allows fast lithium diffusion with stable electrochemical cycling as a cathode in lithium batteries.
Novel oxygen transport membranes with tunable segmented structures
Authors: Joo Jong Hoon , Yun Kyong Sik , Yoo Chung-Yul , Yu Ji Haeng
Published: March 2014

A novel oxygen permeation membrane with a tunable segmented configuration with high oxygen permeation is a promising alternative for industrial oxygen production.
Synthesis and characterization of benzo- and naphtho[2,1-b:3,4-b′]dithiophene-containing oligomers for photovoltaic applications
Authors: Löbert Mirjam , Mishra Amaresh , Uhrich Christian , Pfeiffer Martin , Bäuerle Peter
Published: March 2014

Planarization of the molecular backbone in A–D–A oligomers leads to high fill factors and efficiencies in vacuum-processed organic solar cells.
Communication Strategies and Accommodations Utilized by Health Care Providers With Hearing Loss: A Pilot Study
Authors: Trotter Alanna R. , Matt Susan B. , Wojnar Danuta
Published: March 2014

Purpose

Poor communication between health care providers and patients may negatively impact patient outcomes, and enhancing communication is one way to improve outcomes. Effective communication is particularly important for health care providers who have hearing loss. The authors found that a systematic survey of the communication strategies and experiences of health care providers with hearing loss had not yet been conducted.

Method

In this pilot study, 32 health care professionals with hearing loss were recruited via the Association of Medical Professionals With Hearing Losses and were asked to complete a 28-question survey.

Results

Health care providers with hearing loss already employ strategies that all health care providers are encouraged to use in order to enhance patient–provider communication, and survey participants have found the strategies to be effective.

Conclusions

The communication techniques and assistive technologies used by individuals with hearing loss seem to be effective: All participants reported feeling able to communicate effectively with patients at least most of the time. More research is needed to determine if use of these communication techniques has similar results for health care providers without hearing loss.
Force control of semi‐active valve lag dampers for vibration reduction in helicopters
Authors: Morales Rafael Mauricio , Turner Matthew C. , Court Peter , Hilditch Ross , Postlethwaite Ian
Published: March 2014

This study considers the design of a closed‐loop force‐tracking system for a semi‐active damper, designed to be used to reduce in‐plane vibrations caused by helicopter rotor blades during steady‐state forward flight conditions. The study describes the development of the control law and includes details of (i) how the initial mathematical model of the system is adapted for controller design; (ii) how a non‐linear dynamic inversion (NDI) control law is modified into a form suitable for implementation; and (iii) how the free parameters in the NDI controller can be optimised for various different operational modes. The success of the approach is demonstrated through both force‐tracking simulations and also more comprehensive tests in which the controller is incorporated into a large‐scale vibration simulation of the AgustaWestland 101 helicopter. The results show that the NDI‐based controller can provide a satisfactory level of performance and hence greatly assist in the reduction of unwanted vibrations.
Consensus of descriptor multi‐agent systems via dynamic compensators
Authors: Yang Xin‐Rong , Liu Guo‐Ping
Published: March 2014

This study deals with the consensus problem via dynamic output feedback (dynamic compensator) for descriptor (singular) multi‐agent systems with fixed topologies and agents described by general linear systems. Only output information of each agent can be delivered from its neighbour agents. Based on graph, algebra and descriptor linear system theory, the necessary and sufficient conditions are proposed for the existence of dynamic compensators solving the considered problem. The given conditions depend on both the topologies within descriptor multi‐agent systems and the structure properties of each agent dynamics. According to non‐zero eigenvalues of the Laplacian matrix of the weighted digraph are the same or different, two consensus algorithms via dynamic compensators are proposed, respectively. The provided examples demonstrate the effectiveness of the proposed consensus algorithms.
Prescribed performance fuzzy adaptive fault‐tolerant control of non‐linear systems with actuator faults
Authors: Xu Yinyin , Tong Shaocheng , Li Yongming
Published: March 2014

This study investigates the adaptive fuzzy fault‐tolerant control (FTC) problem for a class of uncertain non‐linear strict‐feedback systems with unmeasured states. The considered non‐linear systems contain unknown continuous functions and do not satisfy the matching condition. The actuator failures under study are types of both abrupt faults and lock‐in‐place and loss of effectiveness. The fuzzy logic systems are employed to approximate the unknown continuous functions, and a fuzzy state observer is developed and the unmeasured states are obtained. Under the framework of the backstepping design technique and incorporated by the dynamic surface control approach and predefined performance bounds, an adaptive fuzzy FTC method has been presented. From the Lyapunov stability analysis, it is shown that all the signals of the resulting closed‐loop system are bounded and the tracking error surfaces remain within the prescribed performance bounds in the presence of unknown non‐linear actuator faults. The simulation results and comparisons with the previous methods indicate the effectiveness of the proposed adaptive fuzzy FTC.
New emerging voltage source converter for high‐voltage application: hybrid multilevel converter with dc side H‐bridge chain links
Authors: Adam Grain Philip , Williams Barry W.
Published: March 2014

Hybrid multilevel converters (HMCs) are more attractive than the traditional multilevel converters, such as modular converters, because they offer all the features needed in a modern voltage source converter‐based dc transmission system with reduced size and weight, at a competitive level of semiconductor losses. Therefore this study investigates the viability of a HMC that uses dc side H‐bridge chain links, for high‐voltage dc and flexible ac transmission systems. In addition, its operating principle, modulation and capacitor voltage balancing, and control are investigated. This study focuses on response of this HMC to ac and dc network faults, with special attention paid to device issues that may arise under extreme network faults. Therefore the HMC with dc side chain links is simulated as one station of point‐to‐point dc transmission system that operates in an inversion mode, with all the necessary control systems incorporated. The major results and findings of subjecting this version of the hybrid converter to ac and dc networks faults are presented and discussed.
Enhanced anomalous photo-absorption from TiO2 nanostructures
Authors: Solanki Vanaraj , Majumder Subrata , Mishra Indrani , Dash P. , Singh C. , Kanjilal D. , Varma Shikha
Published: March 2014

Two dimensional nanostructures have been created on the rutile TiO2 (110) surfaces via ion irradiation technique. Enhanced anomalous photo- absorption response is displayed, where nanostructures of 15 nm diameter with 0.5 nm height, and not the smaller nanostructures with larger surface area, delineate highest absorbance. Comprehensive investigations of oxygen vacancy states, on ion- irradiated surfaces, display a remarkable result that the number of vacancies saturates for higher fluences. A competition between the number of vacancy sites on the nanostructure in conjunction with its size is responsible for the observed anomalous photo-absorption.
Communication: Self-interaction correction with unitary invariance in density functional theory
Authors: Pederson Mark R. , Ruzsinszky Adrienn , Perdew John P.
Published: March 2014

Standard spin-density functionals for the exchange-correlation energy of a many-electron ground state make serious self-interaction errors which can be corrected by the Perdew-Zunger self-interaction correction (SIC). We propose a size-extensive construction of SIC orbitals which, unlike earlier constructions, makes SIC computationally efficient, and a true spin-density functional. The SIC orbitals are constructed from a unitary transformation that is explicitly dependent on the non-interacting one-particle density matrix. When this SIC is applied to the local spin-density approximation, improvements are found for the atomization energies of molecules.
Qualitative link between work of adhesion and thermal conductance of metal/diamond interfaces
Authors: Monachon Christian , Schusteritsch Georg , Kaxiras Efthimios , Weber Ludger
Published: March 2014

We report Time-Domain ThermoReflectance experiments measuring the Thermal Boundary Conductance (TBC) of interfaces between diamond and metal surfaces, based on samples consisting of [111]-oriented diamond substrates with hydrogen or with sp2 carbon surface terminations created using plasma treatments. In a concurrent theoretical study, we calculate the work of adhesion between Ni, Cu, and diamond interfaces with (111) surface orientation, with or without hydrogen termination of the diamond surface, using first-principles electronic structure calculations based on density functional theory (DFT). We find a positive correlation between the calculated work of adhesion and the measured conductance of these interfaces, suggesting that DFT could be used as a screening tool to identify metal/dielectric systems with high TBC. We also explain the negative effect of hydrogen on the thermal conductance of metal/diamond interfaces.
Magnetic memory effects in nickel ferrite/polymer nanocomposites
Authors: Malik Rakesh , Sehdev Neeru , Lamba Subhalakshmi , Sharma Parmanand , Makino Akihiro , Annapoorni Subramanian
Published: March 2014

Memory effects are reported in the field cooled (FC) magnetization of pure nickel ferrite powders and nickel ferrite nanocomposites prepared by the solution casting method. Studies carried out at different concentrations of the nanocomposite indicate that memory effects are suppressed with increasing concentration of the magnetic component in the nanocomposite. This is linked to the increase in the dipolar interaction strength in the nanocomposites, which increase with increasing concentration, as confirmed by the Henkel plots. Model simulations of the FC magnetization carried out on an interacting array of monodispersed magnetic nanoparticles indicate that growing cluster sizes inhibit memory effects.
Resonant intersubband plasmon induced current in InGaAs quantum wells on GaAs
Authors: Holzbauer Martin , Klang Pavel , Detz Hermann , Maxwell Andrews Aaron , Strasser Gottfried , Bakshi Pradip , Gornik Erich
Published: March 2014

We present measurements of the current enhancement due to the coupling of two intersubband plasmons in In0.05Ga0.95As quantum wells. With changing bias, an emissive and an absorptive intersubband plasmon mode cross attractively and trapped electrons in the ground state gain enough energy from the plasma wave to be lifted up to the second subband, where they can contribute to the current. This effect can be directly observed as an increase of 33% in the current. A magnetic field applied parallel to the growth direction allows a control of the strength of the intersubband plasmon coupling up to a quenching.
Effects of Ta incorporation in La2O3 gate dielectric of InGaZnO thin-film transistor
Authors: Qian L. X. , Lai P. T. , Tang W. M.
Published: March 2014

The effects of Ta incorporation in La2O3 gate dielectric of amorphous InGaZnO thin-film transistor are investigated. Since the Ta incorporation is found to effectively enhance the moisture resistance of the La2O3 film and thus suppress the formation of La(OH)3, both the dielectric roughness and trap density at/near the InGaZnO/dielectric interface can be reduced, resulting in a significant improvement in the electrical characteristics of transistor. Among the samples with different Ta contents, the one with a Ta/(Ta + La) atomic ratio of 21.7% exhibits the best performance, including high saturation carrier mobility of 23.4 cm2/V·s, small subthreshold swing of 0.177 V/dec, and negligible hysteresis. Nevertheless, excessive incorporation of Ta can degrade the device characteristics due to newly generated Ta-related traps.
Clinical networks influencing policy and practice: the establishment of advanced practice pharmacist roles for specialist palliative care services in South Australia
Authors: Swetenham Kate , Rowett Debra , Stephenson David
Published: March 2014

Objectives To operationalise the concept of ‘advanced practice roles’ in pharmacy within the new integrated regionalised palliative care service model outlined in the Palliative Care Services Plan 2009–2016, SA Health. Methods A working group was established under the auspices of the Palliative Care Clinical Network to progress the development of advanced practice pharmacist roles for regionalised palliative care services. A pharmacy stakeholder forum was conducted in December 2010 to provide further guidance on the advanced practice pharmacist roles in the following domains: education; network links and partnerships; quality and safety; and research. Results Advanced practice pharmacist positions were created for each of the three regionalised palliative care services in South Australia (SA). Funding was obtained for a Statewide Palliative Care Pharmacy Network project, to build a sustainable community-based palliative care pharmacy network. Advanced practice pharmacists commenced in the regionalised palliative care services of SA on 4 October 2011. Conclusions The Statewide Palliative Care Clinical Network and the SA Palliative Care Plan provided a policy framework that supported involvement and advocacy in the planning of the advanced practice pharmacist roles. Collaboration between leaders in workforce reform, service planners, specialist palliative care providers and the pharmacy sector was a key enabler for developing the advanced practice pharmacist positions for regionalised palliative care services. What is known about the topic? The advanced practice palliative care pharmacist role reflects a new direction for the discipline of pharmacy and has been embraced at a time when a nationally endorsed Advanced Pharmacy Practice Framework has been published, while recognising that registration for pharmacists in Australia currently does not have specific endorsement for advanced practice. What does this paper add? This paper outlines the value of collaboration across settings and sectors. There is an opportunity for these roles to align with the new nationally endorsed framework for advanced practice in pharmacy. What are the implications for practitioners? These new positions strengthen the links between the hospital and community pharmacy sectors to enhance a quality use of medicines approach with improved access to end-of-life medicines for home-based palliative care clients, which actively facilitates a home death for those who choose it.
At the crossroads of violence and aggression in the emergency department: perspectives of Australian emergency nurses
Authors: Morphet Julia , Griffiths Debra , Plummer Virginia , Innes Kelli , Fairhall Robyn , Beattie Jill
Published: March 2014

Objective Violence is widespread in Australian emergency departments (ED) and most prevalent at triage. The aim of the present study was to identify the causes and common acts of violence in the ED perceived by three distinct groups of nurses. Methods The Delphi technique is a method for consensus-building. In the present study a three-phase Delphi technique was used to identify and compare what nurse unit managers, triage and non-triage nurses believe is the prevalence and nature of violence and aggression in the ED. Results Long waiting times, drugs and alcohol all contributed to ED violence. Triage nurses also indicated that ED staff, including security staff and the triage nurses themselves, can contribute to violence. Improved communication at triage and support from management to follow up episodes of violence were suggested as strategies to reduce violence in the ED Conclusion There is no single solution for the management of ED violence. Needs and strategies vary because people in the waiting room have differing needs to those inside the ED. Participants agreed that the introduction and enforcement of a zero tolerance policy, including support from managers to follow up reports of violence, would reduce violence and improve safety for staff. Education of the public regarding ED processes, and the ED staff in relation to patient needs, may contribute to reducing ED violence. What is known about the topic? Violence is prevalent in Australian healthcare, and particularly in emergency departments (ED). Several organisations and government bodies have made recommendations aimed at reducing the prevalence of violence in healthcare but, to date, these have not been implemented consistently, and violence continues. What does this paper add? This study examined ED violence from the perspective of triage nurses, nurse unit managers and non-triage nurses, and revealed that violence is experienced differently by emergency nurses, depending on their area of work. Triage nurses have identified that they themselves contribute to violence in the ED by their style of communication. Nurse unit managers and non-triage nurses perceive that violence is the result of drugs and alcohol, as well as long waiting times. What are the implications for practitioners? Strategies to reduce violence must address the needs of patients and staff both within the ED and in the waiting room. Such strategies should be multifaceted and include education of ED consumers and staff, as well as support from management to respond to reports of violence.
First impressions: towards becoming a health-literate health service
Authors: Johnson Anne
Published: March 2014

A ‘health-literate organisation’ recognises that miscommunication is very common and can negatively affect consumer care and outcomes, and makes it easier for people to navigate, understand, and use health information and services. This paper reports on the First Impressions Activities conducted by consumers to assess aspects of the literacy environment of a rural health service. The First Impressions Activities consists of three tools to assist health services to begin to consider some of the characteristics of their organisation that help and hinder a consumer’s ability to physically navigate their way to and about the health service. The results show that navigation to and within the rural health service was made more complex due to lack of information, difficulty finding information, inconsistent terminology used in signage, missing signage, signage obscured by foliage, and incorrect signage.

What is known about the topic?
The environment of a health service represents the health literacy expectations, preferences and skills of those providing health information and services.

What does this paper add?
This case study offers insight into the literacy demands placed on consumers, as well as an effective tool to assess aspects of those health literacy demands.

What are the implications for practitioners?
Health services can use the First Impressions Activities to actively engage consumers in the assessment of their first impressions of the health service shaped by a phone call, a visit to the website and a walk to the entrance and to different destinations. These activities can assist a health service to begin to examine the navigation of the service through ‘fresh eyes’, using a structured process to identify ways to decrease the health literacy demands on consumers.
Water uptake and redistribution during drought in a semiarid shrub species
Authors: Prieto Iván , Pugnaire Francisco I. , Ryel Ronald J.
Published: March 2014

In arid systems, most plant mortality occurs during long drought periods when water is not available for plant uptake. In these systems, plants often benefit from scarce rain events occurring during drought but some of the mechanisms underlying this water use remain unknown. In this context, plant water use and redistribution after a large rain event could be a mechanism that allows deep-rooted shrubs to conservatively use water during drought. We tested this hypothesis by comparing soil and plant water dynamics in Artemisia tridentata ssp. vaseyana (Rydb.) Beetle shrubs that either received a rain event (20 mm) or received no water. Soil water content (SWC) increased in shallow layers after the event and increased in deep soil layers through hydraulic redistribution (HR). Our results show that Artemisia shrubs effectively redistributed the water pulse downward recharging deep soil water pools that allowed greater plant water use throughout the subsequent drought period, which ameliorated plant water potentials. Shrubs used shallow water pools when available and then gradually shifted to deep-water pools when shallow water was being used up. Both HR recharge and the shift to shallow soil water use helped conserve deep soil water pools. Summer water uptake in Artemisia not only improved plant water relations but also increased deep soil water availability during drought.
Regulation of microtubule minus-end dynamics by CAMSAPs and Patronin
Authors: Hendershott Melissa C. , Vale Ronald D.
Published: March 2014

Significance

Many microtubule (MT) plus-end regulators have been described, but regulation of MT minus-ends remains poorly understood. Recently, the related calmodulin-regulated spectrin-associated proteins (CAMSAPs) CAMSAP2/3 (vertebrate) and Patronin (
Drosophila
) were shown to bind minus-ends, but their effects on MT dynamics in vitro have not been studied. Here, by using in vitro assays, we show that minus-end binding and stabilization are properties of all CAMSAPs. However, their effects on minus-end growth and decoration are variable among different members of this family. Together, these studies solidify the role of CAMSAPs/Patronin as MT minus-end regulatory proteins and reveal how evolution has tuned their activities to affect minus-ends in distinct ways.
Powerful knowledge and geographical education
Authors: Roberts Margaret
Published: March 2014

Michael Young has argued that pupils should be given access to ‘powerful knowledge’. This article examines the extent to which his concept of powerful knowledge is applicable to geographical education, in particular to the study of urban geography. It explores the distinction Young makes between everyday and school knowledge, how this relates to geographical education and to the academic subject of geography. It then considers the extent to which geographical disciplinary knowledge has the characteristics of powerful knowledge. Finally, it raises issues related to curriculum and pedagogy.
Cardiopulmonary Exercise Testing Suggests a Beneficial Response to Pulmonary Endarterectomy in a Patient with Chronic Thromboembolic Obstruction and Normal Preoperative Pulmonary Hemodynamics
Authors: McCabe Colm , Preston Stephen D. , Gopalan Deepa , Dunning John , Pepke‐Zaba Joanna
Published: March 2014

Pulmonary endarterectomy offers a symptomatic and survival benefit in patients with chronic thromboembolic pulmonary hypertension through sustained improvement in right ventricular function. However, its role in patients with symptom limitation, chronic thrombotic obstruction, and a normal pulmonary hemodynamic profile is less clear. Cardiopulmonary exercise testing (CPET) stresses the cardiopulmonary system and has a characteristic response in pulmonary hypertension. CPET may therefore reveal abnormalities in patients with chronic thrombotic obstruction where hemodynamic investigations conducted at rest are reassuring. Using incremental CPET, we demonstrated improvements in right ventricular performance and ventilatory efficiency following pulmonary endarterecomy in a patient with preoperative exercise limitation and normal pulmonary hemodynamics. Careful evaluation of exercise responses may extend the potential benefit offered by pulmonary endarterectomy in patients with chronic thromboembolic obstruction irrespective of their resting hemodynamic profile.
Hydrocortisone Normalizes Phosphodiesterase‐5 Activity in Pulmonary Artery Smooth Muscle Cells from Lambs with Persistent Pulmonary Hypertension of the Newborn
Authors: Perez Marta , Wedgwood Stephen , Lakshminrusimha Satyan , Farrow Kathryn N. , Steinhorn Robin H.
Published: March 2014

Phosphodiesterase‐5 (PDE5) is the primary phosphodiesterase in the pulmonary vasculature. It degrades cyclic guanosine monophosphate (cGMP) and inhibits cGMP‐mediated vasorelaxation. We previously reported that hydrocortisone treatment decreased hyperoxia‐induced PDE5 activity and markers of oxidative stress in lambs with persistent pulmonary hypertension of the newborn (PPHN) ventilated with 100% O2. The objective of our study was to determine the molecular mechanism by which hydrocortisone downregulates PDE5 and oxidative stress in fetal pulmonary artery smooth muscle cells (FPASMCs) from PPHN lambs. PPHN FPASMC were incubated for 24 hours in either 21% or 95% O2. Some cells were treated with 100 nM hydrocortisone and/or ±1 μM helenalin, an inhibitor of nuclear factor κ B (NFκB), a redox‐sensitive transcription factor. Exposure to hyperoxia led to increased PDE5 activity, oxidative stress, and NFκB activity. Pretreatment of PPHN FPASMC with hydrocortisone normalized PDE5 activity, decreased cytosolic oxidative stress, increased expression of extracellular superoxide dismutase and NFκB inhibitory protein, and decreased NFκB activity. Similarly, treatment with NFκB inhibitor, helenalin, decreased PDE5 activity. These data suggest that hyperoxia activates NFκB, which in turn induces PDE5 activity in PPHN FPASMC, whereas treatment with hydrocortisone attenuates these changes by blocking reactive oxygen species‐induced NFκB activity.
Water saturation effects on elastic wave attenuation in porous rocks with aligned fractures
Authors: Amalokwu Kelvin , Best Angus I. , Sothcott Jeremy , Chapman Mark , Minshull Tim , Li Xiang-Yang
Published: March 2014

Elastic wave attenuation anisotropy in porous rocks with aligned fractures is of interest to seismic remote sensing of the Earth's structure and to hydrocarbon reservoir characterization in particular. We investigated the effect of partial water saturation on attenuation in fractured rocks in the laboratory by conducting ultrasonic pulse-echo measurements on synthetic, silica-cemented, sandstones with aligned penny-shaped voids (fracture density of 0.0298 ± 0.0077), chosen to simulate the effect of natural fractures in the Earth according to theoretical models. Our results show, for the first time, contrasting variations in the attenuation (Q−1) of P and S waves with water saturation in samples with and without fractures. The observed Qs/Qp ratios are indicative of saturation state and the presence or absence of fractures, offering an important new possibility for remote fluid detection and characterization.
Alternative bacteriophage life cycles: the carrier state ofCampylobacter jejuni
Authors: Siringan Patcharin , Connerton Phillippa L. , Cummings Nicola J. , Connerton Ian F.
Published: March 2014

Members of the genusCampylobacterare frequently responsible for human enteric disease, often through consumption of contaminated poultry products. Bacteriophages are viruses that have the potential to control pathogenic bacteria, but understanding their complex life cycles is key to their successful exploitation. Treatment ofCampylobacter jejunibiofilms with bacteriophages led to the discovery that phages had established a relationship with their hosts typical of the carrier state life cycle (CSLC), where bacteria and bacteriophages remain associated in equilibrium. Significant phenotypic changes include improved aerotolerance under nutrient-limited conditions that would confer an advantage to survive in extra-intestinal environments, but a lack in motility eliminated their ability to colonize chickens. Under these circumstances, phages can remain associated with a compatible host and continue to produce free virions to prospect for new hosts. Moreover, we demonstrate that CSLC host bacteria can act as expendable vehicles for the delivery of bacteriophages to new host bacteria within pre-colonized chickens. The CSLC represents an important phase in the ecology ofCampylobacterbacteriophage.
Perpetuation of H5N1 and H9N2 avian influenza viruses in natural water bodies
Authors: Zhang Hongbo , Li Yan , Chen Jianjun , Chen Quanjiao , Chen Ze
Published: March 2014

Water bodies are an important route for the spread and transmission of avian influenza virus (AIV). The determining factor for an AIV to transmit through diffusion in water is the term of viability of the virus in the water body. To better understand the perpetuation of AIV in natural water bodies, and thus the risks of AIV spread and transmission via such bodies, we systematically studied the inactivation dynamics of two AIV strains (H5N1 and H9N2) at different temperatures in water bodies of important migratory bird habitats within China (Dongting Lake, Poyang Lake, the Hubei segment of the Yangtze River and Qinghai Lake). We also studied the impact of water-borne micro-organisms on the perpetuation of AIV. Our findings indicated that water is very likely an important route for the epidemic spread of AIV, especially during the autumn and winter seasons. In addition, water-borne micro-organisms might antagonize the persistence of AIV.
Susceptibility of European jackdaws (Corvus monedula) to experimental infection with lineage 1 and 2 West Nile viruses
Authors: Lim Stephanie M. , Brault Aaron C. , van Amerongen Geert , Sewbalaksing Varsha D. , Osterhaus Albert D. M. E. , Martina Byron E. E. , Koraka Penelope
Published: March 2014

Mass bird mortality has been observed in North America after the introduction ofWest Nile virus(WNV), most notably massive die-offs of American crows (Corvus brachyrhynchos). In contrast, WNV epidemic activity in Europe has been characterized by very low incidences of bird mortality. As the general susceptibility of European corvids to strains of WNV remains in question, European jackdaws (Corvus monedula) were inoculated with WNV strains circulating currently in Greece (Greece-10), Italy (FIN and Ita09) and Hungary (578/10), as well as a North American (NY99) genotype with a demonstrated corvid virulence phenotype. Infection with all strains except WNV-FIN resulted in mortality. Viraemia was observed for birds inoculated with all strains and virus was detected in a series of organs upon necropsy. These results suggested that jackdaws could potentially function as a sentinel for following WNV transmission in Europe; however, elicited viraemia levels might be too low to allow for efficient transmission of virus to mosquitoes.
How many digits in a mean are worth reporting?
Authors: Clymo R. S.
Published: March 2014

Most bioscientists need to report mean values, yet many have little idea of how many digits are significant, and at what point further digits are mere random junk. Thus a recent report that the mean of 17 values was 3.863 with a standard error of the mean (SEM) of 2.162 revealed only that none of the seven authors understood the limitations of their work. The simple rule derived here by experiment for restricting a mean value to its significant digits (sig-digs) is this: the last sig-dig in the mean value is at the same decimal decade as the first sig-dig (the first non-zero) in the SEM. An extended rule for the mean, and a different rule for the SEM itself are also derived. For the example above the reported values should be a mean of 4 with SEM 2.2. Routine application of these simple rules will often show that a result is not as compelling as one had hoped.
Inputs drive cell phenotype variability
Authors: Park James , Brureau Anthony , Kernan Kate , Starks Alexandria , Gulati Sonali , Ogunnaike Babatunde , Schwaber James , Vadigepalli Rajanikanth
Published: March 2014

What is the significance of the extensive variability observed in individual members of a single-cell phenotype? This question is particularly relevant to the highly differentiated organization of the brain. In this study, for the first time, we analyze the in vivo variability within a neuronal phenotype in terms of input type. We developed a large-scale gene-expression data set from several hundred single brainstem neurons selected on the basis of their specific synaptic input types. The results show a surprising organizational structure in which neuronal variability aligned with input type along a continuum of sub-phenotypes and corresponding gene regulatory modules. Correlations between these regulatory modules and specific cellular states were stratified by synaptic input type. Moreover, we found that the phenotype gradient and correlated regulatory modules were maintained across subjects. As these specific cellular states are a function of the inputs received, the stability of these states represents “attractor”-like states along a dynamic landscape that is influenced and shaped by inputs, enabling distinct state-dependent functional responses. We interpret the phenotype gradient as arising from analog tuning of underlying regulatory networks driven by distinct inputs to individual cells. Our results change the way we understand how a phenotypic population supports robust biological function by integrating the environmental experience of individual cells. Our results provide an explanation of the functional significance of the pervasive variability observed within a cell type and are broadly applicable to understanding the relationship between cellular input history and cell phenotype within all tissues.
Parameterization of the coupling between strain and order parameter for LuF[SeO3]
Authors: Magdysyuk Oxana V. , Müller Melanie , Dinnebier Robert E. , Lipp Christian , Schleid Thomas
Published: March 2014

The high-temperature phase transition of LuF[SeO3] has been characterized by time-resolved high-resolution synchrotron powder diffraction. On heating, a second-order structural phase transition was found at 393 K, while on cooling the same phase transition occurs at 371 K, showing a large hysteresis typical for a first-order phase transition. Detailed analysis using sequential and parametric whole powder pattern fitting revealed that the coupling between the strain and the displacive order parameter determines the behaviour of the material during the phase transition. Different possible coupling mechanisms have been evaluated and the most probable rationalized.
An iterative method to extract the size distribution of non-interacting polydisperse spherical particles from small-angle scattering data
Authors: Sen D. , Das Avik , Mazumder S.
Published: March 2014

In this article, an iterative method for estimating the size distribution of non-interacting polydisperse spherical particles from small-angle scattering data is presented. It utilizes the iterative addition of relevant contributions to an instantaneous size distribution, as obtained from the fractional difference between the experimental data and the simulated profile. An inverse relation between scattering vector and real space is assumed. This method does not demand the consideration of any basis function set together with an imposed constraint such as a Lagrange multiplier, nor does it depend on the Titchmarsh transform. It is demonstrated that the method works quite well in extracting several forms of distribution. The robustness of the present method is examined through the successful retrieval of several forms of distribution, namely monomodal, bimodal, trimodal, triangular and bitriangular distributions. Finally, the method has also been employed to extract the particle size distribution from experimental small-angle X-ray scattering data obtained from colloidal dispersions of silica.
On identification of symmetric and improperly quasi-symmetric grain boundaries
Authors: Glowinski Krzysztof
Published: March 2014

Symmetric and improperly quasi-symmetric grain boundaries have special geometric features. They are important reference boundaries in quantitative studies of boundary networks. Methods for identification of symmetric and improperly quasi-symmetric boundaries used so far, which are based on distance functions defined in the space of boundary parameters, are computationally complex and inefficient. In this article, new parameters that approximate the distances to the nearest symmetric and improperly quasi-symmetric boundaries are defined to simplify and speed up the analyses. Very strong correlations between the new parameters and the corresponding distances validate these new parameters to be a suitable replacement for the distances. Distributions of the introduced parameters may serve as characteristics of boundary networks. As an example, the new parameters are applied to the studies of symmetric and improperly quasi-symmetric characters of boundaries in three-dimensional microstructure data collected from a nickel-based superalloy.
An idealized molecular geometry library for refinement of poorly behaved molecular fragments with constraints
Authors: Guzei Ilia A.
Published: March 2014

An idealized molecular geometry library with 40 geometries of molecules and ions optimized by density functional theory methods has been created. All geometries are accessible through a web site. The library entries are tailored for constrained (also known as rigid body) refinements of problematic small-molecule structures with theOLEX2andSHELXLsoftware packages. The library application is demonstrated with the refinement of a Pd complex,trans-Pd(dimethyl sulfoxide)(OH2)(trifluoroacetate)2, that co-crystallizes in a 2:1 ratio with a solvent molecule of ethyl acetate disordered over an inversion center. Alternative approaches to constrained refinements are discussed.
Structure evolution with Sr content of the perovskite-like materials La2−xSrxCoTiO6(0 ≤x≤ 0.5)
Authors: Gómez-Pérez Alejandro , Pérez-Flores Juan Carlos , Ritter Clemens , Boulahya Khalid , Castro German R. , García-Alvarado Flaviano , Amador Ulises
Published: March 2014

The oxide series La2−xSrxCoTiO6(0 ≤x≤ 1.0) belong to the perovskite family with general formulaABO3. The evolution of the room-temperature structure as a function of the Sr content was studied using complementary techniques by applying the symmetry-adapted modes formalism (AMPLIMODES). In the compositional range presented in this article (0 ≤x≤ 0.5), the compounds adopt distorted perovskite structures of monoclinic (space groupP21/n) or orthorhombic (space groupPnma) symmetry, both with octahedral tilting scheme (a−a−c+) (out of phase along two perovskite main directions and in phase along the third direction). The main difference between these structures is the existence of rock-salt order ofBions in the monoclinic symmetry, which is lost forx≥ 0.30. As the Sr content increases, a better matching of theA—O andB—O distances occurs. This is produced by an elongation of theA—O distance as La3+is replaced by the larger ion Sr2+, and the shortening of theB—O distance due to the oxidation of Co2+to Co3+induced by the aliovalent substitution. As a result, the cuboctahedralA-site cavity becomes less and less distorted; theAion tends to occupy its ideal positions, increasing its coordination and giving rise to a more symmetrical structure. In the whole compositional range, the symmetry-adapted atomic displacements (modes) responsible for the out-of-phase tilting of theBO6octahedra remain active but those associated with the in-phase tilting become negligible, anticipating forx≥ 0.6 a transition to a new structure with tilting scheme either (a0a0c−) (space groupI4/mcm) or (a−a−a0) (space groupImma) or (a−a−a−) (space groupR\overline 3c).
Phase-sensitive small-angle neutron scattering
Authors: Majkrzak C. F. , Krycka K. , Krueger S. , Berk N. F. , Kienzle P. , Maranville B.
Published: March 2014

A method is described for determining the neutron scattering length density distribution of a molecular-scale object directly from phase-sensitive small-angle neutron scattering (SANS). The structure factor amplitude is obtained through the use of a reference structure for a collection of randomly oriented, identical objects in the dilute solution limit (negligible interparticle correlations). This work extends some of the techniques developed in recent years for phase-sensitive specular neutron reflectometry to SANS, although the approach presented here is applicable only within the range of validity of the Born approximation. The scattering object is treated as a composite consisting of an `unknown' part of interest plus a reference component, the real-space structure of the latter being completely known. If, for example, the reference part of the object is composed of a ferromagnetic material (the magnetization of which is saturated), then polarized neutron beams can be employed to extract the information required for an unambiguous inversion of the scattering data without chemical substitution. The angular averaging over all possible relative orientations of the composite object does not result in a cancellation of the phase information since the reference and unknown parts of each object have a fixed spatial relationship. The new approach proposed here is not simply another type of isomorphic substitution, but also involves a reformulation of the underlying mathematical analysis of this particular scattering problem.
Characterization of TEMPO-oxidized cellulose nanofibers in aqueous suspension by small-angle X-ray scattering
Authors: Su Ying , Burger Christian , Hsiao Benjamin S. , Chu Benjamin
Published: March 2014

Cellulose nanofibers, extracted from wood pulps using the (2,2,6,6-tetramethylpiperidine-1-yl)oxyl (TEMPO)-mediated oxidation method, are low-cost, sustainable and high-performance materials with potential usage in many applications. The structural information of these cellulose nanofibers in aqueous suspension was characterized by synchrotron small-angle X-ray scattering (SAXS). A simplified ribbon model having a near rectangular cross section was found to give the best fit to the SAXS results. The analytical expression of the ribbon model also led to a higher calculation efficiency compared with the more conventional parallelepiped model. The extracted structural information included the cross-section size and size distribution of the cellulose nanofibers. For example, for nanofibers prepared from the dried pulp of the maritime pine, the size-weighted averages of thickness and width were 3.2 and 12.7 nm, respectively, and the corresponding standard deviations were 2.2 and 5.5 nm, respectively. The scattering results of the size-weighted average of the nanofiber width are also consistent with those determined directly from transmission electron microscopy.
Structure determination from powder data without prior indexing, using a similarity measure based on cross-correlation functions
Authors: Habermehl Stefan , Mörschel Philipp , Eisenbrandt Pierre , Hammer Sonja M. , Schmidt Martin U.
Published: March 2014

A method to refine organic crystal structures from powder diffraction data with incorrect lattice parameters has been developed. The method is based on the similarity measure developed by de Gelderet al.[J. Comput. Chem.(2001),22, 273–289], using the cross- and auto-correlation functions of a simulated and an experimental powder pattern. The lattice parameters, molecular position, molecular orientation and selected intramolecular degrees of freedom are optimized until the similarity measure reaches a maximum; subsequently, a Rietveld refinement is carried out. The programFIDEL(FIt with DEviating Lattice parameters) implements this method. The procedure is also suitable for unindexed powder data, powder diagrams of very low quality and powder diagrams of non-phase-pure samples. Various applications are shown, including structure determinations from powder data using crystal structure predictions by standard force-field methods. Other useful applications include the automatic structure determination from powder data starting from the crystal structures of isostructural compounds (e.g.a solvate, hydrate or chemical derivative), or from crystal data measured at a different temperature or pressure.