bluuebunny/crossref_metadata_2025 huggingface dataset:
Chitosan–alginate multilayered films with gradients of physicochemical cues
Authors: Silva Joana M. , Caridade Sofia G. , Oliveira Nuno M. , Reis Rui L. , Mano João F.
Published: April 2015

A new approach was used to create multilayered films with gradients of physicochemical properties. This approach shows promise for the development of other types of gradients, which will be useful to mimic extracellular architecture.
High homocysteine induces betaine depletion
Authors: Imbard Apolline , Benoist Jean-François , Esse Ruben , Gupta Sapna , Lebon Sophie , de Vriese An S , de Baulny Helene Ogier , Kruger Warren , Schiff Manuel , Blom Henk J.
Published: April 2015

Betaine is the substrate of the liver- and kidney-specific betaine-homocysteine (Hcy) methyltransferase (BHMT), an alternate pathway for Hcy remethylation. We hypothesized that BHMT is a major pathway for homocysteine removal in cases of hyperhomocysteinaemia (HHcy). Therefore, we measured betaine in plasma and tissues from patients and animal models of HHcy of genetic and acquired cause. Plasma was collected from patients presenting HHcy without any Hcy interfering treatment. Plasma and tissues were collected from rat models of HHcy induced by diet and from a mouse model of cystathionine β-synthase (CBS) deficiency. S-adenosyl-methionine (AdoMet), S-adenosyl-homocysteine (AdoHcy), methionine, betaine and dimethylglycine (DMG) were quantified by ESI—LC–MS/MS. mRNA expression was quantified using quantitative real-time (QRT)-PCR. For all patients with diverse causes of HHcy, plasma betaine concentrations were below the normal values of our laboratory. In the diet-induced HHcy rat model, betaine was decreased in all tissues analysed (liver, brain, heart). In the mouse CBS deficiency model, betaine was decreased in plasma, liver, heart and brain, but was conserved in kidney. Surprisingly, BHMT expression and activity was decreased in liver. However, in kidney, BHMT and SLC6A12 expression was increased in CBS-deficient mice. Chronic HHcy, irrespective of its cause, induces betaine depletion in plasma and tissues (liver, brain and heart), indicating a global decrease in the body betaine pool. In kidney, betaine concentrations were not affected, possibly due to overexpression of the betaine transporter SLC6A12 where betaine may be conserved because of its crucial role as an osmolyte.
Improved delay‐dependent exponential stability of singular systems with mixed interval time‐varying delays
Authors: Van Hien Le , Vu Le Huy , Phat Vu Ngoc
Published: April 2015

This study deals with the problem of exponential stability analysis for a class of singular systems with interval time‐varying discrete and distributed delays. By constructing a set of improved Lyapunov–Krasovskii functionals, new delay‐dependent conditions are established in terms of linear matrix inequalities ensuring the regularity, impulse free and exponential stability of the system. This approach allows the authors to compute simultaneously the two bounds that characterise the exponential stability rate of the solution by various efficient convex optimisation algorithms. Numerical examples are given to illustrate the effectiveness of the obtained results.
Common‐mode voltage mitigation with a predictive control method considering dead time effects of three‐phase voltage source inverters
Authors: Kwak Sangshin , Mun Sungki
Published: April 2015

This study proposes a technique to mitigate common‐mode voltages with dead time effects taken into account in three‐phase voltage source inverters (VSIs), on the basis of finite‐set model predictive control methods. The effects of dead time on common‐mode voltage in three‐phase VSIs controlled by the model predictive control method are investigated. On the basis of the investigation, a common‐mode voltage reduction method is proposed, which is not affected by the inevitable dead time of the VSIs. The proposed method pre‐excludes, from the candidates for future vectors, those voltage vectors which can increase the common‐mode voltage during the dead time. In addition, when zero vectors are chosen as an optimal vector from the standpoints of current errors, each zero vector is replaced with two non‐zero vectors in opposite directions, so as not to deteriorate current performance by simply excluding the zero vectors. On the basis of the proposed pre‐selective technique, the proposed method can restrict the common‐mode voltage within ±Vdc/6 of the three‐phase VSIs, whereas the common‐mode voltages of the conventional method vary within ±Vdc/2. Simulation and experimental results are presented to verify the effectiveness of the proposed method.
Graphics processing unit‐based alignment of protein interaction networks
Authors: Xie Jiang , Zhou Zhonghua , Ma Jin , Xiang Chaojuan , Nie Qing , Zhang Wu
Published: April 2015

Network alignment is an important bridge to understanding human protein–protein interactions (PPIs) and functions through model organisms. However, the underlying subgraph isomorphism problem complicates and increases the time required to align protein interaction networks (PINs). Parallel computing technology is an effective solution to the challenge of aligning large‐scale networks via sequential computing. In this study, the typical Hungarian‐Greedy Algorithm (HGA) is used as an example for PIN alignment. The authors propose a HGA with 2‐nearest neighbours (HGA‐2N) and implement its graphics processing unit (GPU) acceleration. Numerical experiments demonstrate that HGA‐2N can find alignments that are close to those found by HGA while dramatically reducing computing time. The GPU implementation of HGA‐2N optimises the parallel pattern, computing mode and storage mode and it improves the computing time ratio between the CPU and GPU compared with HGA when large‐scale networks are considered. By using HGA‐2N in GPUs, conserved PPIs can be observed, and potential PPIs can be predicted. Among the predictions based on 25 common Gene Ontology terms, 42.8% can be found in the Human Protein Reference Database. Furthermore, a new method of reconstructing phylogenetic trees is introduced, which shows the same relationships among five herpes viruses that are obtained using other methods.
Frühzeitige Selektion von Risikopatienten für Typ-2-Diabetes in der Hausarztpraxis durch Medizinische Fachangestellte – Eine Machbarkeitsstudie
Authors: Schnakenberg R. , Rothe M. , Bleckwenn M.
Published: April 2015

Ziel der Studie: Wir untersuchten, ob Risikopatienten für einen Typ-2-Diabetes von Medizinischen Fachangestellten (MFA) im hausärztlichen Praxisalltag anhand weniger Merkmale erkannt werden können. Durch eine gezielte Ansprache von krankheitsgefährdeten Personen könnte die Effektivität eines Diabetes-Risiko-Screenings verbessert werden.

Methode: Im Rahmen der Machbarkeitsstudie „SeRiFIN“ wurden in 6 Hausarztpraxen (Interventionsgruppe) Patienten zwischen 20 und 50 Jahren mit einer positiven Familienanamnese für Diabetes und einer bauchbetonten Adipositas von geschulten MFA angesprochen. Zur Feststellung des Diabetesrisikos sollten die selektionierten Patienten den FINDRISK-Fragebogen ausfüllen. In den 5 Kontrollpraxen wurden Patienten aus derselben Altersgruppe ohne bekannten Typ-2-Diabetes gebeten, eine Risikoanalyse mit dem FINDRISK-Bogen durchzuführen.

Ergebnisse: Es wurden 916 FINDRISK-Fragebögen ausgewertet. In der Selektionsgruppe gaben 62% der befragten Patienten einen Diabetes in der Verwandtschaft an. Bei 86% der Patienten war der Taillenumfang vergrößert. Bei 22% der angesprochenen Patienten wurde ein Risiko von über 30% in den nächsten 10 Jahren einen Typ-2-Diabetes zu entwickeln festgestellt. In der nicht selektionierten Gruppe hatten nur 7% der Patienten ein abklärungsbedürftiges Risiko. Darüber hinaus unterschied sich die Risikogruppe in der angegebenen täglichen Bewegung und im Essverhalten signifikant von der Kontrollgruppe. Die MFA-Schulung wurde ebenso wie die Durchführung der Intervention gut angenommen und als machbar neben der Routinearbeit einer MFA eingeschätzt und die MFA drückten ihr Erstaunen über die Effektivität dieser Vorselektion aus.

Schlussfolgerung: Nach einer Schulung erkennen MFA Risikopatienten für einen Typ-2-Diabetes verlässlich in ihrem Praxisalltag. Die gezielte Ansprache von Risikopatienten kann an die MFA delegiert werden. Dadurch sind die Zeitressourcen der Ärzte effektiver für eine Präventionsbehandlung einsetzbar. Vor allem kardiovaskuläre Risikopatienten könnten von einer möglichst frühen Identifikation und Ansprache profitieren.
Dynamic patterns in the reduced Craik–Leibovich equations
Authors: Zhang Zhexuan , Chini Gregory P. , Julien Keith , Knobloch Edgar
Published: April 2015

Numerical simulations of an asymptotically reduced version of the Craik–Leibovich (CL) equations are described. By filtering surface waves, the CL equations facilitate simulations of surface-wave driven or surface-wave modified phenomena in the upper ocean—most notably, Langmuir circulation (LC)—with time scales long relative to the period of the dominant waves. Although numerical simulations of the fully three-dimensional CL equations are now routine, simulations in spatially extended domains, hundreds of times the characteristic width of individual LC vortices, require immense computing resources. The reduced CL (rCL) equations render numerical simulations in very long domains more feasible by exploiting the strongly anisotropic structure of LC that emerges in the strong CL “vortex force” limit. Here, simulations of the rCL equations are performed to explore the dynamics admitted by the reduced system. Spatially quasi-coherent, three-dimensional flow structures that drift downwind are found to be a prominent feature of the reduced dynamics in the parameter regime explored. The spatial form and temporal variability of these structures are associated with a resonance between pairs of LC vortices with cross-wind (transverse) wavenumbers in a 2:1 ratio. Depending upon the strength of the wind and surface-wave forcing, this spatial resonance leads to either periodic or aperiodic temporal oscillations in the number of LC vortices crossing a fixed downwind station, a process that is accompanied by the formation of Y-shaped features in Lagrangian surface patterns. The stems of these “Y-junctions” are preferentially oriented downwind, as is commonly reported in field observations of LC.
Magnetically tunable wideband microwave filter using ferrite-based metamaterials
Authors: Bi Ke , Zhu Wenting , Lei Ming , Zhou Ji
Published: April 2015

Magnetically tunable wideband microwave filters have been designed and prepared by using ferrite-based metamaterial structures. The microwave properties of the filters have been investigated by experiments and simulations. The negative permeability appears around the ferromagnetic resonance frequency, which leads to a remarkable stopband for the bandstop filter. The bandpass filter is composed of two kinds of ferrite rods with different saturation magnetization. The bandwidth of the passband can be tuned by adjusting the saturation magnetization of the ferrite rods. Both the experimental and the simulated results show that those filters possess magnetically tunable property. This approach opens a way for designing tunable wideband microwave filters.
The impact of poloidal asymmetries on tungsten transport in the core of JET H-mode plasmas
Authors: Angioni C. , Casson F. J. , Mantica P. , Pütterich T. , Valisa M. , Belli E. A. , Bilato R. , Giroud C. , Helander P. ,   JET Contributors
Published: April 2015

Recent progress in the understanding and prediction of the tungsten behaviour in the core of JET H-mode plasmas with ITER-like wall is presented. Particular emphasis is given to the impact of poloidal asymmetries of the impurity density. In particular, it is shown that the predicted reduction of temperature screening induced by the presence of low field side localization of the tungsten density produced by the centrifugal force is consistent with the observed tungsten behaviour in a JET discharge in H-mode baseline scenario. This provides first evidence of the role of poloidal asymmetries in reducing the strength of temperature screening. The main differences between plasma parameters in JET baseline and hybrid scenario discharges which affect the impact of poloidally asymmetric density on the tungsten radial transport are identified. This allows the conditions by which tungsten accumulation can be avoided to be more precisely defined.
Characterization of the magnetic interactions of multiphase magnetocaloric materials using first-order reversal curve analysis
Authors: Franco V. , Béron F. , Pirota K. R. , Knobel M. , Willard M. A.
Published: April 2015

In order to understand the magnetocaloric response of materials, it is important to analyze the interactions between the different phases present in them. Recent models have analyzed the influence of these interactions on the magnetocaloric response of composites, providing an estimate value of the interaction field that is consistent with experimental results. This paper analyzes to which extent magnetization first-order reversal curve (FORC) method can be used to calculate these interactions. It is shown that the different field ranges that are explored using these techniques (inside the hysteretic region for FORC; close to magnetic saturation for magnetocaloric effect) produce interaction field values that differ in order of magnitude, with FORC being sensitive to the lower values of the interaction field and magnetocaloric analysis accounting for the larger interactions.
Theory of femtosecond coherent double-pump single-molecule spectroscopy: Application to light harvesting complexes
Authors: Chen Lipeng , Gelin Maxim F. , Domcke Wolfgang , Zhao Yang
Published: April 2015

We develop a first principles theoretical description of femtosecond double-pump single-molecule signals of molecular aggregates. We incorporate all singly excited electronic states and vibrational modes with significant exciton-phonon coupling into a system Hamiltonian and treat the ensuing system dynamics within the Davydov D1 Ansatz. The remaining intra- and inter-molecular vibrational modes are treated as a heat bath and their effect is accounted for through lineshape functions. We apply our theory to simulate single-molecule signals of the light harvesting complex II. The calculated signals exhibit pronounced oscillations of mixed electron-vibrational (vibronic) origin. Their periods decrease with decreasing exciton-phonon coupling.
Turbulent transport regimes and the scrape-off layer heat flux width
Authors: Myra J. R. , D'Ippolito D. A. , Russell D. A.
Published: April 2015

Understanding the responsible mechanisms and resulting scaling of the scrape-off layer (SOL) heat flux width is important for predicting viable operating regimes in future tokamaks and for seeking possible mitigation schemes. In this paper, we present a qualitative and conceptual framework for understanding various regimes of edge/SOL turbulence and the role of turbulent transport as the mechanism for establishing the SOL heat flux width. Relevant considerations include the type and spectral characteristics of underlying instabilities, the location of the gradient drive relative to the SOL, the nonlinear saturation mechanism, and the parallel heat transport regime. We find a heat flux width scaling with major radius R that is generally positive, consistent with the previous findings [Connor et al., Nucl. Fusion 39, 169 (1999)]. The possible relationship of turbulence mechanisms to the neoclassical orbit width or heuristic drift mechanism in core energy confinement regimes known as low (L) mode and high (H) mode is considered, together with implications for the future experiments.
Analytical theory of the shear Alfvén continuum in the presence of a magnetic island
Authors: Cook C. R. , Hegna C. C.
Published: April 2015

The effect of a magnetic island chain on the shear Alfvén continuum is calculated analytically. Using a WKB approximation of the linearized ideal MHD equations, the island is shown to cause an upshift in the continuum accumulation point frequency. This minimum of the frequency spectrum is shifted from the rational surface to the island separatrix. The structure of the eigenmodes is also presented.
Effects of extrinsic point defects in phosphorene: B, C, N, O, and F adatoms
Authors: Wang Gaoxue , Pandey Ravindra , Karna Shashi P.
Published: April 2015

Phosphorene is emerging as a promising 2D semiconducting material with a direct band gap and high carrier mobility. In this paper, we examine the role of the extrinsic point defects including surface adatoms in modifying the electronic properties of phosphorene using density functional theory. The surface adatoms considered are B, C, N, O, and F with a [He] core electronic configuration. Our calculations show that B and C, with electronegativity close to P, prefer to break the sp3 bonds of phosphorene and reside at the interstitial sites in the 2D lattice by forming sp2 like bonds with the native atoms. On the other hand, N, O, and F, which are more electronegative than P, prefer the surface sites by attracting the lone pairs of phosphorene. B, N, and F adsorption will also introduce local magnetic moment to the lattice. Moreover, B, C, N, and F adatoms will modify the band gap of phosphorene, yielding metallic transverse tunneling characters. Oxygen does not modify the band gap of phosphorene, and a diode like tunneling behavior is observed. Our results therefore offer a possible route to tailor the electronic and magnetic properties of phosphorene by the adatom functionalization and provide the physical insights of the environmental sensitivity of phosphorene, which will be helpful to experimentalists in evaluating the performance and aging effects of phosphorene-based electronic devices.
Microfluidic emulsification through a monolithic integrated glass micronozzle suspended inside a flow-focusing geometry
Authors: Liu Yifan , Yobas Levent
Published: April 2015

Microfluidic devices have shown remarkable success in generating emulsions with precise control over their size. Yet, highly sensitive nature of generation mechanism to surface wettability requires such devices to be built out of specific materials showing homogenous wettability that favors the continuous phase rather than the dispersed phase. Moreover, the need to switch the continuous phase and the dispersed phase requires switching the device wettability by applying a suitable surface treatment. Here, we demonstrate a microfluidic device that can generate water-in-oil and oil-in-water emulsions without the necessity of surface treatment. The device features a suspended glass micronozzle integrated inside a flow-focusing geometry formed by silicon and poly(dimethylsiloxane) channels where drops of the dispersed phase can be sheared off at the micronozzle tip without touching channel walls in a coflow of the continuous phase. The micronozzle structure is a partially released segment of a self-enclosed capillary entirely built in phosphosilicate glass and with a cylindrical lumen ∼1.5 μm in diameter. Owing to high fluidic resistance of such fine capillary, emulsion generation in the device takes place in a dripping process and no noticeable jet formation of the dispersed phase has been observed throughout the tested flow rates. The effect of the flow rates on the diameter of the emulsions and their rate of generation has been experimentally investigated and found to show a similar trend to that of a simple physical model based on the critical Capillary number.
Diffusion current characteristics of defect-limited nBn mid-wave infrared detectors
Authors: Savich G. R. , Sidor D. E. , Du X. , Morath C. P. , Cowan V. M. , Wicks G. W.
Published: April 2015

Mid-wave infrared, nBn detectors remain limited by diffusion current generated in the absorber region even when defect concentrations are elevated. In contrast, defect-limited conventional pn-junction based photodiodes are subject to Shockley-Read-Hall generation in the depletion region and subsequent carrier drift. Ideal nBn-architecture devices would be limited by Auger 1 generation; however, typical nBn detectors exhibit defect-dominated performance associated with Shockley-Read-Hall generation in the quasi-neutral absorbing region. Reverse saturation current density characteristics for defect-limited devices depend on the minority carrier diffusion length, absorbing layer thickness, and the dominant minority carrier generation mechanism. Unlike pn-based photodiodes, changes in nBn dark current due to elevated defect concentrations do not manifest at small biases, thus, the zero bias resistance area product, RoA, is not a useful parameter for characterizing nBn-architecture photodetector performance.
Apertureless scanning microscope probe as a detector of semiconductor laser emission
Authors: Dunaevskiy Mikhail , Dontsov Anton , Alekseev Prokhor , Monakhov Andrei , Baranov Alexei , Girard Paul , Arinero Richard , Teissier Roland , Titkov Alexander
Published: April 2015

An operating semiconductor laser has been studied using a scanning probe microscope. A shift of the resonance frequency of probe that is due to its heating by laser radiation has been analyzed. The observed shift is proportional to the absorbed radiation and can be used to measure the laser near field or its output power. A periodical dependence of the measured signal has been observed as a function of distance between the probe and the surface of the laser due to the interference of the outgoing and cantilever-reflected waves. Due to the multiple reflections resulting in the interference, the light absorption by the probe cantilever is greatly enhanced compared with a single pass case. Interaction of infrared emission of a diode laser with different probes has been studied.
Broadband unidirectional transmission of sound in unblocked channel
Authors: Zhu Yi-Fan , Zou Xin-Ye , Liang Bin , Cheng Jian-Chun
Published: April 2015

We have designed and experimentally fabricated a straight channel capable of realizing unidirectional acoustic transmission within a broad band while leaving a gap much wider than the wavelength that may serve as a passage for other entities such as fluids or objects. This extraordinary feature stems from a distinctly different mechanism that directs the sound path asymmetrically by employing acoustic metasurfaces. The numerical and experimental results agree quite well with the theoretical predictions. Our scheme may open up avenue for the design of acoustic one-way devices and have potentials in various applications such as architectural acoustics or medical ultrasound.
Investigation of chemical distribution in the oxide bulk layer in Ti/HfO2/Pt memory devices using x-ray photoelectron spectroscopy
Authors: Jiang Ran , Du Xianghao , Han Zuyin , Sun Weideng
Published: April 2015

Resistive switching (RS) of Ti/HfO2/Pt memory devices was studied using X-ray photoelectron spectroscopy. Hf4+ monotonously decreases with depth increasing towards to HfO2/Pt interface in low resistance state, while a fluctuation distribution of Hf4+ is shown in high resistance state (HRS) and in the pristine Ti/HfO2/Pt devices (without any SET or RESET process). It is explained by the existence of locally accumulated oxygen vacancies (clusters) in the oxide bulk layer in HRS and pristine states. A dynamic model of RS processes was proposed that the oxygen vacancy clusters dominantly determines the resistivity by the connecting/rupture between the neighbor cluster sites in the bulk.
Splash, pop, sizzle: Information processing with phononic computing
Authors: Sklan Sophia R.
Published: April 2015

Phonons, the quanta of mechanical vibration, are important to the transport of heat and sound in solid materials. Recent advances in the fundamental control of phonons (phononics) have brought into prominence the potential role of phonons in information processing. In this review, the many directions of realizing phononic computing and information processing are examined. Given the relative similarity of vibrational transport at different length scales, the related fields of acoustic, phononic, and thermal information processing are all included, as are quantum and classical computer implementations. Connections are made between the fundamental questions in phonon transport and phononic control and the device level approach to diodes, transistors, memory, and logic.
Effects of lithium insertion on thermal conductivity of silicon nanowires
Authors: Xu Wen , Zhang Gang , Li Baowen
Published: April 2015

Recently, silicon nanowires (SiNWs) have been applied as high-performance Li battery anodes, since they can overcome the pulverization and mechanical fracture during lithiation. Although thermal stability is one of the most important parameters that determine safety of Li batteries, thermal conductivity of SiNWs with Li insertion remains unclear. In this letter, using molecular dynamics simulations, we study room temperature thermal conductivity of SiNWs with Li insertion. It is found that compared with the pristine SiNW, there is as much as 60% reduction in thermal conductivity with 10% concentration of inserted Li atoms, while under the same impurity concentration the reduction in thermal conductivity of the mass-disordered SiNW is only 30%. With lattice dynamics calculations and normal mode decomposition, it is revealed that the phonon lifetimes in SiNWs decrease greatly due to strong scattering of phonons by vibrational modes of Li atoms, especially for those high frequency phonons. The observed strong phonon scattering phenomenon in Li-inserted SiNWs is similar to the phonon rattling effect. Our study serves as an exploration of thermal properties of SiNWs as Li battery anodes or weakly coupled with impurity atoms.
The demonstration of a D-SMT stressor on Ge planer n-MOSFETs
Authors: Liao M.-H. , Chen P.-G.
Published: April 2015

An approximately 31% Id,sat improvement and 42% mobility enhancement are achieved on the planer Ge n-Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) by implementing the dislocation-stress memorization technology (D-SMT) stressor for the first time, based on an investigation of crystal re-growth velocities along different directions and the optimization of the dislocation angle (θ) in Ge. Ultra-high stress (>3 GPa) capping SiN film is found to be essential for modifying the crystal re-growth velocities along the [100] and [110] directions to optimize the θ. The change of crystal re-growth velocities and the mobility enhancement ratio with the stress along the assigned directions in Ge is also discussed, respectively.
Ultrafast laser and swift heavy ion irradiation: Response of Gd2O3 and ZrO2 to intense electronic excitation
Authors: Rittman Dylan R. , Tracy Cameron L. , Cusick Alex B. , Abere Michael J. , Torralva Ben , Ewing Rodney C. , Yalisove Steven M.
Published: April 2015

In order to investigate the response of materials to extreme conditions, there are several approaches to depositing extremely high concentrations of energy into very small volumes of material, including ultrafast laser and swift heavy ion (SHI) irradiation. In this study, crystalline-to-crystalline phase transformations in cubic Gd2O3 and monoclinic ZrO2 have been investigated using ultrafast laser irradiation. The phases produced by the extreme conditions of irradiation were characterized by grazing incidence x-ray diffraction (GIXRD) and Raman spectroscopy. Gd2O3 exhibited a cubic-to-monoclinic phase transformation, as evidenced by the appearance of the monoclinic (402¯), (003), (310), and (112¯) peaks in the GIXRD pattern and of four Ag and three Bg Raman modes. ZrO2 underwent a monoclinic-to-tetragonal phase transformation, as evidenced by the emergence of the tetragonal (101) peak in the GIXRD pattern and of Eg and A1g Raman modes. The new phases formed by ultrafast laser irradiation are high temperature polymorphs of the two materials. No evidence of amorphization was seen in the GIXRD data, though Raman spectroscopy indicated point defect accumulation. These results are identical to those produced by irradiation with SHIs, which also deposit energy in materials primarily through electronic excitation. The similarity in damage process and material response between ultrafast laser and SHI irradiation suggests a fundamental relationship between these two techniques.
Modeling of long range surface plasmon polariton cladded membrane waveguides with integrated grating couplers as hydrogen sensors
Authors: Fong Norman R. , Berini Pierre , Tait R. Niall
Published: April 2015

The design of a long range surface plasmon polariton cladded membrane waveguide with grating couplers is proposed. The device consists of a gold stripe embedded in a thin Cytop membrane with a palladium over-layer and can be used as a hydrogen sensor. Input and output light coupling is achieved through integrated gold grating couplers directly on the waveguides. The design is approached through finite element method modeling. Waveguide and sensor designs are compared and discussed via a 2D modal analysis. The design and optimization of input and output grating couplers are also presented.
Productivity results and physiological response of the gastrointestinal tract of rabbits fed diets containing rapeseed cake and wheat distillers dried grains with solubles
Authors: Gugołek A. , Juśkiewicz J. , Wyczling P. , Kowalska D. , Strychalski J. , Konstantynowicz M. , Zwoliński C.
Published: April 2015

This study was aimed at determining the possibility of applying rapeseed cake (RC) and wheat distillers dried grains with solubles (DDGS) in diets for HYPLUS meat-type rabbits (n = 64, aged 35–84 days). Control diet (SC) contained 5% of extracted soybean meal. In RC diet, the soybean meal was replaced by RC, in DG diet – by wheat DDGS, whereas in RC–DG diet – by a mixture of RC and wheat DDGS (2.5% each). The study included production analyses, digestibility-balance experiment and physiological assessment of gut response to experimental factors hence data was collected on daily bodyweight gains, feed intake and slaughter performance, nutrients digestibility, nitrogen retention and gut response. The latter included assessment of parameters describing the small intestinal, cecal, and colonic environment of rabbits (e.g. digesta viscosity, ammonia concentration, bacterial enzymes activity, short-chain fatty acid concentration). The highest productivity results were reported for SC group and the lowest ones for DG group. The RC and RC–DG groups were characterised by intermediate productivity. Dressing percentage and contents of carcass elements did not differ among the groups (except for the hind part). Nutrients digestibility and nitrogen retention were the highest in the SC group and the lowest in DG group. The dietary incorporation of DDGS resulted in undesired responses of the gastrointestinal tract including excessively watery digesta in the small intestine, increased concentration of cecal and colonic ammonia, enhanced activity of potentially harmful bacterial β-glucuronidase in cecal digesta, and increased cecal concentration of putrefactive short-chain fatty acids. These negative effects were not due to RC and RC–DG dietary treatments, apart from decreased dry matter concentration in the small intestine in the RC–DG group. In general, the results of our study demonstrated that 5% rape cake can be successfully incorporated into rabbit dietary regimen as a substitute of dietary soybean meal. Considering that the productivity of rabbits fed 2.5% of DDGS (with 2.5% rape cake) and these receiving 5% rape cake was comparable, optional seems also dietary inclusion of up to 2.5% wheat DDGS The higher content of DDGS (5%) in the diet deteriorated most of the growth parameters of rabbits.
A promising and simple method to quantify soil/manure mixing on beef feedlot pens
Authors: Pratt Chris , Redding Matthew , Hill Jaye
Published: April 2015

On beef cattle feed pen surfaces, fresh and decayed manure is mixed with base rock or soil (base). Quantifying this mixing has beneficial applications for aspects including nutrient and greenhouse gas budgeting. However, no practical methods exist to quantify mixing. We investigated if measuring element concentrations in: (A) fresh manure, (B) base material, and (C) pen manure offers a promising method to quantify manure/base mixing on pen surfaces. Using three operational beef feedlots as study sites, we targeted carbon (C), and silicon (Si), which are the two most abundant and easily measurable organic and inorganic elements. Our results revealed that C concentrations were strongly (>15 times) and significantly (P < 0.05) higher whereas Si concentrations strongly (>10 times) and significantly (P < 0.01) lower in fresh manure than base material at all three sites. These relative concentrations were not significantly impacted by manure decay, as determined by an 18-week incubation experiment. This suggested that both of these elements are suitable markers for quantifying base/manure mixing on pens. However, due to the chemical change of manure during decay, C was shown to be an imprecise marker of base/manure mixing. By contrast, using Si to estimate base/manure mixing was largely unaffected by manure decay. These findings were confirmed by measuring C and Si concentrations in stockpiled pen surface manure from one of the sites. Using Si concentrations is a promising approach to quantify base/manure mixing on feed pens given that this element is abundantly concentrated in soils and rocks.
A survey of the meat goat industry in Queensland and New South Wales. 1. General property information, goat and pasture management
Authors: Nogueira D. M. , Gardiner C. P. , Gummow B. , Cavalieri J. , Fitzpatrick L. A. , Parker A. J.
Published: April 2015

This study aimed to survey farmers’ knowledge and practices on the management of pastures, stocking rates and markets of meat goat-producing enterprises within New South Wales and Queensland, Australia. An interview-based questionnaire was conducted on properties that derived a significant proportion of their income from goats. The survey covered 31 landholders with a total land area of 567 177 ha and a reported total of 160 010 goats. A total of 55% (17/31) of producers were involved in both ‘opportunistic harvesting’ and commercial goat operations, and 45% (14/31) were specialised seedstock producers. Goats were the most important livestock enterprise on 55% (17/31) of surveyed properties. Stocking rate varied considerably (0.3–9.3 goats/ha) within and across surveyed properties and was found to be negatively associated with property size and positively associated with rainfall. Overall, 81% (25/31) of producers reported that the purpose of running goats on their properties was to target international markets. Producers also cited the importance of targeting markets as a way to increase profitability. Fifty-three percent of producers were located over 600 km from a processing plant and the high cost of freight can limit the continuity of goats supplied to abattoirs. Fencing was an important issue for goat farmers, with many producers acknowledging this could potentially add to capital costs associated with better goat management and production. Producers in the pastoral regions appear to have a low investment in pasture development and opportunistic goat harvesting appears to be an important source of income.
Integrating forest fuels and land cover data for improved estimation of fuel consumption and carbon emissions from boreal fires
Authors: Anderson Kerry , Simpson Brian , Hall Ronald J. , Englefield Peter , Gartrell Michael , Metsaranta Juha M.
Published: April 2015

Estimating carbon emissions from wildland fires is complicated by the large variation in both forest fuels and burning conditions across Canada’s boreal forest. The potential for using spatial fuel maps to improve wildland fire carbon emission estimates in Canada’s National Forest Carbon Monitoring, Accounting and Reporting System (NFCMARS) was evaluated for select wildfires (representing a transect across western Canada) occurring in 2003 and 2004 at four study areas in western Canada. Area-normalised emission rates and total emissions differed by fuels data source, mainly as a function of the treatment of open fuels in the higher resolution spatial fuel models. The use of spatial data to refine the selection of stand types that probably burned and the use of fire weather conditions specific to the fire increased the precision of total carbon emission estimates, relative to computational procedures used by Canada’s NFCMARS. Estimates of total emissions from the NFCMARS were consistent with the regional and national data sources following the spatial approach, suggesting the two approaches had equivalent accuracies. Though it cannot be said with certainty that the inclusion of this detailed information improved accuracy, the spatial approach offers the promise or potential for more accurate results, pending more consistent fuel maps, especially at finer scales.
The Sonata Principle Reformulated for Haydn Post-1770 and a Typology of his Recapitulatory Strategies
Authors: Riley Matthew
Published: April 2015

Haydn's ‘recomposition’ of the recapitulation is well known, but this article proposes, against received wisdom, that Haydn composed as though following a rule in the recapitulations of fast sonata-form movements from the 1770s onwards. The article extends William E. Caplin's functional theory to the Haydn recapitulation in order to revive the ‘sonata principle’, restated and limited to fast movements in Haydn's instrumental cycles. It then lays out a typology of Haydn's recapitulatory strategies that unfold within the constraints of the sonata principle.
‘Sparks of Meaning’: Comics, Music and Alan Moore
Authors: Summers Tim
Published: April 2015

Comics have become a significant part of modern popular culture. This article examines the ways in which music is involved with comics, and develops methods for analysing musical moments in comic books. The output of the writer Alan Moore (b. 1953) is used as the domain for examining music and comics. This popular author's works are notable for their sophisticated use of music and their interaction with wider musical culture. Using case studies from the comic books V for Vendetta (1982–9), Watchmen (1986–7) and the second and third volumes of The League of Extraordinary Gentlemen (2002–12), the article demonstrates that the comic can be a musically significant medium (even to the point of becoming a piece of virtual musical theatre), and argues that music in comics serves to encourage readers to engage in hermeneutic criticism of musical and musical-literary texts.
Recurrence of dual-strainClostridium difficileinfection in anin vitrohuman gut model
Authors: Crowther Grace S. , Chilton Caroline H. , Todhunter Sharie L. , Nicholson Scott , Freeman Jane , Wilcox Mark H.
Published: April 2015

Background

Clostridium difficile infection (CDI) is still a major challenge to healthcare facilities. The detection of multiple C. difficile strains has been reported in some patient samples during initial and recurrent CDI episodes. However, the behaviour of individual strains and their contribution to symptomatic disease is unclear.

Methods

An in vitro human gut model was used to investigate the germination and proliferation of two distinct C. difficile strains during initial and recurrent simulated CDI, as well as their response to vancomycin treatment. The gut model was inoculated with a pooled human faecal emulsion and indigenous gut microbiota, C. difficile populations (vegetative and spore forms), cytotoxin levels and antimicrobial activity were monitored throughout the experiment.

Results

Both C. difficile strains germinated and proliferated in response to ceftriaxone instillation, with cytotoxin detected during the peak vegetative growth. Vancomycin instillation resulted in a rapid decline in the vegetative forms of both strains, with only spores remaining 2 days after the start of dosing. A recrudescence of both strains occurred following the cessation of vancomycin installation, although this was observed more quickly, and to a greater extent, in one strain than the other.

Conclusions

Within a human gut model, multiple C. difficile strains are able to germinate and proliferate concurrently in response to antibiotic challenge (the onset of simulated CDI). Similarly, more than one strain can proliferate during simulated recurrent CDI, although with differences in germination and growth rate and timing. It appears probable that multiple strains can contribute to CDI within an individual patient, with possible implications for management and bacterial transmission.
Failure to Validate a Multivariable Clinical Prediction Model to Identify Pediatric Intensive Care Unit Patients at High Risk for Candidemia
Authors: Fisher Brian T. , Ross Rachael K. , Roilides Emmanuel , Palazzi Debra L. , Abzug Mark J. , Hoffman Jill A. , Berman David M. , Prasad Priya A. , Localio A. Russell , Steinbach William J. , Vogiatzi Lambrini , Dutta Ankhi , Zaoutis Theoklis E.
Published: April 2015

We attempted to validate a previously derived clinical prediction rule for candidemia in the pediatric intensive care unit. This multicenter case control study did not identify significant association of candidemia with most of the previously identified predictors. Additional study in larger cohorts with other predictor variables is needed.
Switch to Raltegravir From Protease Inhibitor or Nonnucleoside Reverse-Transcriptase Inhibitor Does not Reduce Visceral Fat In Human Immunodeficiency Virus-Infected Women With Central Adiposity
Authors: Lake Jordan E. , McComsey Grace A. , Hulgan Todd , Wanke Christine A. , Mangili Alexandra , Walmsley Sharon L. , Currier Judith S.
Published: April 2015

Human immunodeficiency virus-infected women with central adiposity switched to raltegravir-based antiretroviral therapy immediately or after 24 weeks. No statistically significant changes in computed tomography-quantified visceral adipose tissue (VAT) or subcutaneous fat were observed, although 48 weeks of raltegravir was associated with a 6.4% VAT decline. Raltegravir for 24 weeks was associated with improvements in lipids.
FromAnimaculumto single molecules: 300 years of the light microscope
Authors: Wollman Adam J. M. , Nudd Richard , Hedlund Erik G. , Leake Mark C.
Published: April 2015

Although not laying claim to being the inventor of the light microscope, Antonj van Leeuwenhoek (1632–1723) was arguably the first person to bring this new technological wonder of the age properly to the attention of natural scientists interested in the study of living things (people we might now term ‘biologists’). He was a Dutch draper with no formal scientific training. From using magnifying glasses to observe threads in cloth, he went on to develop over 500 simple single lens microscopes (Baker & Leeuwenhoek 1739Phil. Trans.41, 503–519. (doi:10.1098/rstl.1739.0085)) which he used to observe many different biological samples. He communicated his finding to the Royal Society in a series of letters (Leeuwenhoek 1800The select works of Antony Van Leeuwenhoek, containing his microscopical discoveries in many of the works of nature, vol. 1) including the one republished in this edition ofOpen Biology. Our review here begins with the work of van Leeuwenhoek before summarizing the key developments over the lastca300 years, which has seen the light microscope evolve from a simple single lens device of van Leeuwenhoek's day into an instrument capable of observing the dynamics of single biological molecules inside living cells, and to tracking every cell nucleus in the development of whole embryos and plants.
How could preventive therapy affect the prevalence of drug resistance? Causes and consequences
Authors: Kunkel Amber , Colijn Caroline , Lipsitch Marc , Cohen Ted
Published: April 2015

Various forms of preventive and prophylactic antimicrobial therapies have been proposed to combat HIV (e.g. pre-exposure prophylaxis), tuberculosis (e.g. isoniazid preventive therapy) and malaria (e.g. intermittent preventive treatment). However, the potential population-level effects of preventative therapy (PT) on the prevalence of drug resistance are not well understood. PT can directly affect the rate at which resistance is acquired among those receiving PT. It can also indirectly affect resistance by altering the rate at which resistance is acquired through treatment for active disease and by modifying the level of competition between transmission of drug-resistant and drug-sensitive pathogens. We propose a general mathematical model to explore the ways in which PT can affect the long-term prevalence of drug resistance. Depending on the relative contributions of these three mechanisms, we find that increasing the level of coverage of PT may result in increases, decreases or non-monotonic changes in the overall prevalence of drug resistance. These results demonstrate the complexity of the relationship between PT and drug resistance in the population. Care should be taken when predicting population-level changes in drug resistance from small pilot studies of PT or estimates based solely on its direct effects.
Big city, small world: Density, contact rates, and transmission of dengue across Pakistan
Authors: Kraemer M.U.G. , Perkins T.A. , Cummings D.A.T. , Zakar R. , Hay S.I. , Smith D.L. , Reiner R.C.
Published: April 2015

Macroscopic descriptions of populations commonly assume that encounters between individuals are well mixed; i.e., each individual has an equal chance of coming into contact with any other individual. Relaxing this assumption can be challenging though, due to the difficulty of acquiring detailed knowledge about the non-random nature of encounters. Here, we fitted a mathematical model of dengue virus transmission to spatial time series data from Pakistan and compared maximum-likelihood estimates of “mixing parameters” when disaggregating data across an urban-rural gradient. We show that dynamics across this gradient are subject not only to differing transmission intensities but also to differing strengths of nonlinearity due to differences in mixing. We furthermore show that neglecting spatial variation in mixing can lead to substantial underestimates of the level of effort needed to control a pathogen with vaccines or other control efforts. We complement this analysis with relevant contemporary environmental drivers of dengue.