bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced dense attosecond electron bunch generation by irradiating an intense laser on a cone target
Authors: Hu Li-Xiang , Yu Tong-Pu , Shao Fu-Qiu , Zou De-Bin , Yin Yan
Published: March 2015

By using two-dimensional particle-in-cell simulations, we demonstrate enhanced spatially periodic attosecond electron bunches generation with an average density of about 10nc and cut-off energy up to 380 MeV. These bunches are acquired from the interaction of an ultra-short ultra-intense laser pulse with a cone target. The laser oscillating field pulls out the cone surface electrons periodically and accelerates them forward via laser pondermotive force. The inner cone wall can effectively guide these bunches and lead to their stable propagation in the cone, resulting in overdense energetic attosecond electron generation. We also consider the influence of laser and cone target parameters on the bunch properties. It indicates that the attosecond electron bunch acceleration and propagation could be significantly enhanced without evident divergency by attaching a plasma capillary to the original cone tip.
A comparison of ion beam measurements by retarding field energy analyzer and laser induced fluorescence in helicon plasma devices
Authors: Gulbrandsen N. , Fredriksen Å. , Carr J. , Scime E.
Published: March 2015

Both Laser-Induced Fluorescence (LIF) and Retarding Field Energy Analyzers (RFEA) have been applied to the investigation of beams formed in inductively coupled helicon plasmas. While the LIF technique provides a direct measurement of the velocity distribution in the plasma, the RFEA measures ion flux as a function of a retarding potential. In this paper, we present a method to compare the two techniques, by converting the LIF velocity distribution to an equivalent of a RFEA measurement. We applied this method to compare new LIF and RFEA measurements in two different experiments; the Hot Helicon Experiment (HELIX) - Large Experiment on Instabilities and Anisotropies (LEIA) at West Virginia University and Njord at University of Tromsø. We find good agreement between beam energies of the two methods. In agreement with earlier observations, the RFEA is found to measure ion beams with densities too low for the LIF to resolve. In addition, we present measurements of the axial development of the ion beam in both experiments. Beam densities drop exponentially with distance from the source, both in LIF and RFEA measurements. The effective quenching cross section from LIF in LEIA is found to be σb,*=4×10−19 m2, and the effective beam collisional cross sections by RFEA in Njord to be σb=1.7×10−18 m2.
A new magnetic compound fluid slurry and its performance in magnetic field-assisted polishing of oxygen-free copper
Authors: Wang Youliang , Wu Yongbo , Guo Huiru , Fujimoto Masakazu , Nomura Mitsuyoshi , Shimada Kunio
Published: March 2015

In nano-precision surface finishing of engineering materials using MCF (magnetic compound fluid) slurry, the water-based MCF slurry is preferable from the viewpoint of the environmental issue and the running cost of cleaning workpiece and equipment. However, the uncoated-CIPs (carbonyl-iron-powders) within the conventional MCF slurry have low ability against aqueous corrosion, leading to the performance deterioration and working life shortening of the conventional MCF slurry. This study proposed a new MCF slurry containing ZrO2-coated CIPs instead of the uncoated CIPs. Its performance in the polishing of oxygen-free copper was compared experimentally with that of the conventional one. The results showed that the work-surface finish polished with the new slurry was in the same level as that with the conventional one when the slurry was used soon after prepared, i.e., the settling time was 0 min; however, as the settling time increased the uncoated-CIPs got rusty, leading to a deterioration in the slurry performance. By contrast, no rust was observed on ZrO2-coated CIPs even the settling time reached several days, indicating the employment of ZrO2-coated CIPs prolonged the working-life of the MCF slurry greatly.
Lubricant reflow after laser heating in heat assisted magnetic recording
Authors: Wu Haoyu , Mendez Alejandro Rodriguez , Xiong Shaomin , Bogy David B.
Published: March 2015

In heat assisted magnetic recording (HAMR) technology for hard disk drives, the media will be heated to about 500 °C during the writing process in order to reduce its magnetic coercivity and thus allow data writing with the magnetic head transducers. The traditional lubricants such as Z-dol and Z-tetraol may not be able to perform in such harsh heating conditions due to evaporation, decomposition and thermal depletion. However, some of the lubricant depletion can be recovered due to reflow after a period of time, which can help to reduce the chance of head disk interface failure. In this study, experiments of lubricant thermal depletion and reflow were performed using a HAMR test stage for a Z-tetraol type lubricant. Various lubricant depletion profiles were generated using different laser heating conditions. The lubricant reflow process after thermal depletion was monitored by use of an optical surface analyzer. In addition, a continuum based lubrication model was developed to simulate the lubricant reflow process. Reasonably good agreement between simulations and experiments was achieved.
Stratification of discharge in noble gases from the viewpoint of the discrete dynamics
Authors: Golubovskii Yu. , Pelyukhova E. , Sigeneger F. , Nekuchaev V.
Published: March 2015

Based on the analysis of electron phase trajectories in sinusoidal electric fields, a new point of view on discharge stratification is proposed. It is shown that the positive column can be considered as a spatial resonator in which electric fields with a fundamental period length LS or higher mode length qpLS establish, where p and q are integers and p > q. The fundamental mode length LS is equivalent to the distance on which electrons gain energy equal to the lowest excitation threshold. This distance determines a length of the S-striation. Unlike kinetic theory, in the presented model resonance properties of the discharge column are not connected with elastic collision energy losses. A point map is used to obtain the resonance trajectories of electrons in the phase plane. Stable points for the positions of inelastic collisions in the resonance trajectories have been found at the positions of field maxima in the case of integer ratios pq. For non-integer ratios pq, multiple resonance trajectories arise according to a more complex stability criterion. From this point of view, S-, P-, and R-striations in noble gas discharges can be explained. Due to energy losses in elastic collisions, initial electron energy distribution functions converge to the resonance trajectories (the so-called “bunch effect”). The findings of the discrete model agree with results of kinetic theory and experiment. The new approach avoids difficulties of the kinetic theory in the case of exceptionally large relaxation lengths which can even exceed the positive column length.
Towards an optical far-field measurement of higher-order multipole contributions to the scattering response of nanoparticles
Authors: Bauer Thomas , Orlov Sergej , Leuchs Gerd , Banzer Peter
Published: March 2015

We experimentally show an all-optical multipolar decomposition of the lowest-order eigenmodes of a single gold nanoprism using azimuthally and radially polarized cylindrical vector beams. By scanning the particle through these tailored field distributions, the multipolar character of the eigenmodes gets encoded into 2D-scanning intensity maps even for higher-order contributions to the eigenmode that are too weak to be discerned in the direct far-field scattering response. This method enables a detailed optical mode analysis of individual nanoparticles.
Ultrafast thermionic emission from metal irradiated using a femtosecond laser and an electric field in combination
Authors: Wang Tingfeng , Guo Jin , Shao Junfeng , Wang Dinan , Chen Anmin , Jin Mingxing
Published: March 2015

Ultrafast thermionic emission from gold film irradiated with a femtosecond laser pulse in the presence of an additional electric field is analyzed using a two-temperature equation combined with a modified Richardson equation. The calculated results show that the duration of the emission is below 1 ps. Supplying an additional electric field is found to change the emission from the metal surface. Given the same laser fluence, this additional field reduces the work function of the metal, and thus improves the efficiency of thermionic emission. These results help to understand the mechanism and suggest ways to improve emissions in the context of ultrafast thermalized electron systems.
Semi-insulating Sn-Zr-O: Tunable resistance buffer layers
Authors: Barnes Teresa M. , Burst James M. , Reese Matthew O. , Perkins Craig L.
Published: March 2015

Highly resistive and transparent (HRT) buffer layers are critical components of solar cells and other opto-electronic devices. HRT layers are often undoped transparent conducting oxides. However, these oxides can be too conductive to form an optimal HRT. Here, we present a method to produce HRT layers with tunable electrical resistivity, despite the presence of high concentrations of unintentionally or intentionally added dopants in the film. This method relies on alloying wide-bandgap, high-k dielectric materials (e.g., ZrO2) into the host oxide to tune the resistivity. We demonstrate SnxZr1−xO2:F films with tunable resistivities varying from 0.001 to 10 Ω cm, which are controlled by the Zr mole fraction in the films. Increasing Zr suppresses carriers by expanding the bandgap almost entirely by shifting the valence-band position, which allows the HRT layers to maintain good conduction-band alignment for a low-resistance front contact.
Probing the nature of electron transfer in metalloproteins on graphene-family materials as nanobiocatalytic scaffold using electrochemistry
Authors: Gupta Sanju , Irihamye Aline
Published: March 2015

Graphene-based nanomaterials have shown great promise not only in nanoelectronics due to ultrahigh electron mobility but also as biocatalytic scaffolds owing to irreversible protein surface adsorption and facilitating direct electron transfer. In this work, we synthesized stable dispersions of graphene using liquid-phase exfoliation approach based on non-covalent interactions between graphene and 1-pyrenesulfonic acid sodium salt (Py–1SO3), 1-pyrenemethylamine salt (Py − Me-NH2) and Pluronic® P-123 surfactant using only water as solvent compatible with biomolecules. The resulting graphene nanoplatelets (Gr_LPE) are characterized by a combination of analytical (microscopy and spectroscopy) techniques revealing mono- to few-layer graphene displaying that the exfoliation efficiency strongly depends upon the type of pyrene-based salts and organic surfactants. Moreover being completely water-based approach, we build robust nanoscaffolds of graphene-family nanomaterials (GFNs) namely, monolayer graphene, Gr_LPE (the one prepared with Pluronic® P-123), graphene oxide (GO) and its reduced form (rGO) on glassy carbon electrode surface with three important metalloproteins include cytochrome c (Cyt c) [for electron transfer], myoglobin (Mb) [for oxygen storage] and horseradish peroxidase (HRP) [for catalyzing the biochemical reaction]. In order to demonstrate the nanobiocatalytical activity of these proteins, we used electrochemical interfacial direct electron transfer (DET) kinetics and attempt to determine the rate constant (kET) using two different analytical approaches namely, linear sweep voltammetry and Laviron’s theory. We elucidated that all of the metalloproteins retain their structural integrity (secondary structure) upon forming mixtures with GFNs confirmed through optical and vibrational spectroscopy and biological activity using electrochemistry. Among the GFNs studied, Gr-LPE, GO and rGO support the efficient electrical wiring of the redox centers (with an increase in catalytic efficiency of Cyt c and Mb in the presence of GFNs attributed partially to the surface functional (carboxyl, epoxide and hydroxyl) groups on GO and rGO facilitating rapid charge transfer.
Impact of post-deposition annealing on interfacial chemical bonding states between AlGaN and ZrO2 grown by atomic layer deposition
Authors: Ye Gang , Wang Hong , Ng Serene Lay Geok , Ji Rong , Arulkumaran Subramaniam , Ng Geok Ing , Li Yang , Liu Zhi Hong , Ang Kian Siong
Published: March 2015

The effect of post-deposition annealing on chemical bonding states at interface between Al0.5Ga0.5N and ZrO2 grown by atomic layer deposition (ALD) is studied by angle-resolved x-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. It has been found that both of Al-O/Al 2p and Ga-O/Ga 3d area ratio decrease at annealing temperatures lower than 500 °C, which could be attributed to “clean up” effect of ALD-ZrO2 on AlGaN. Compared to Ga spectra, a much larger decrease in Al-O/Al 2p ratio at a smaller take-off angle θ is observed, which indicates higher effectiveness of the passivation of Al-O bond than Ga-O bond through “clean up” effect near the interface. However, degradation of ZrO2/AlGaN interface quality due to re-oxidation at higher annealing temperature (>500 °C) is also found. The XPS spectra clearly reveal that Al atoms at ZrO2/AlGaN interface are easier to get oxidized as compared with Ga atoms.
Erasure temperature measurements of heat assisted magnetic recording media
Authors: Chen Y. J. , Yang H. Z. , Leong S. H. , Cher K. M. , Hu J. F. , Sethi P. , Lew W. S.
Published: March 2015

For heat assisted magnetic recording (HAMR) media development, measurement of erasure temperature (Te) is interesting and important for practical HAMR testing and applications. Here, we present an investigation on Te measurements of L10 ordered FePt granular HAMR media made using a Laser Heating (LH) method on a home-built HAMR write test system versus that from a bulk heating approach. The HAMR write test system provides HAMR writing, micro-MOKE (magneto-optical Kerr effect) signal detection, and MOKE imaging functions at the same testing spot in one single system. Magnetic force microscopy (MFM) and magnetic Kerr microscopy observations of the scanning laser induced degradation/erasure/demagnetization of the pre-recorded magnetic patterns on disk media (over a wide area of a few hundreds of μm2) show that the magnetic (MFM and Kerr signal) amplitude of the pre-recorded magnetic patterns decreases slowly with increasing laser power (Pw) (/temperature rise) for Pw ≲ 66 mW and then drops sharply to nearly zero for Pw ≥ ∼72 mW (the laser power corresponding to complete thermal erasure when the media temperature is ∼Te). It was further found that this trend of magnetic amplitude reduction with increased Pw is similar to that from magnetic amplitude decrease of pre-recorded magnetic patterns with increased bulk heating temperature. The temperature for complete erasure at laser power, Pw = 72 mW for the LH method, corresponds therefore to ∼650 K (≈Te) for the bulk heating methods. Besides fast measurement, LH (as a comparable and viable approach for erasure measurement) is dynamic, localized, and has time scales closer to practical HAMR situation.
Method to determine the optimal silicon nanowire length for photovoltaic devices
Authors: Li Yingfeng , Li Meicheng , Li Ruike , Fu Pengfei , Chu Lihua , Song Dandan
Published: March 2015

The length of the silicon nanowire (SiNW) is a key parameter in photovoltaic devices, as it dramatically decides the light-harvesting and carrier recombination. Here, we develop a method to determine the optimal SiNW length for photovoltaic devices, by comparing the light-harvesting efficiency of SiNWs with various lengths. The light-harvesting efficiency is measured by the light intensity in the SiNW, and the fraction of the length with high light intensity in its whole length. Under these criteria, we find that the optimal SiNW length is around 3 μm. This method is helpful in further optimization and application of SiNW-based solar cells.
Streamline based design guideline for deterministic microfluidic hydrodynamic single cell traps
Authors: Guan Allan , Shenoy Aditi , Smith Richard , Li Zhenyu
Published: March 2015

A prerequisite for single cell study is the capture and isolation of individual cells. In microfluidic devices, cell capture is often achieved by means of trapping. While many microfluidic trapping techniques exist, hydrodynamic methods are particularly attractive due to their simplicity and scalability. However, current design guidelines for single cell hydrodynamic traps predominantly rely on flow resistance manipulation or qualitative streamline analysis without considering the target particle size. This lack of quantitative design criteria from first principles often leads to non-optimal probabilistic trapping. In this work, we describe an analytical design guideline for deterministic single cell hydrodynamic trapping through the optimization of streamline distributions under laminar flow with cell size as a key parameter. Using this guideline, we demonstrate an example design which can achieve 100% capture efficiency for a given particle size. Finite element modelling was used to determine the design parameters necessary for optimal trapping. The simulation results were subsequently confirmed with on-chip microbead and white blood cell trapping experiments.
Surface plasmons at the Brillouin zone boundary of an oblique lattice
Authors: Constant Thomas J. , Vukusic Pete , Hibbins Alastair P. , Sambles J. Roy
Published: March 2015

In periodic systems of low-symmetry, the Bragg condition for the complete interference of waves along the contour of the Brillouin zone (BZ) boundary is not generally satisfied. As a result, band-gaps do not necessarily occur at this boundary. This letter demonstrates this experimentally by recording the iso-frequency contours for surface plasmon polaritons (SPPs) supported on a diffraction grating with an underlying 2D oblique Bravias lattice. It is shown that these contours do not intersect the BZ boundary perpendicularly, as the symmetry operations of the lattice place no conditions on the surface wave interference at this boundary.
Typical form of characteristic function of two-point velocity distribution in homogeneous isotropic turbulence and its extension to the three-point version
Authors: Hosokawa Iwao
Published: March 2015

A necessary and sufficient form of two-point velocity characteristic function to embody two-point velocity distribution in turbulence is constructed on the mathematical basis of homogeneity and isotropy. This is applied in the first equation (for one-point velocity probability density) of the Monin-Lundgren hierarchy to see its substantial effect on the dynamics of homogeneous isotropic turbulence, the pressure term in which then is proved to vanish, as argued in “One-point velocity statistics in decaying homogeneous isotropic turbulence,” Phys. Rev. E 78, 066312 (2008). Furthermore, an approximate form of three-point velocity characteristic function is searched on this basis, so that we obtain a simple closed hierarchy at the second equation stage. Thereby a certain closure method for the hierarchy in homogeneous, isotropic turbulence is illuminated from a new point of view.
Models for the study of whole-body insulin kinetics: a mathematical synthesis.
Authors: McKnight L. L. , Lopez S. , Shoveller A. K. , France J.
Published: March 2015

Insulin is an anabolic hormone that plays a central role in glucose homeostasis. Synthesis, secretion and appearance of insulin in portal and peripheral circulation are complex and tightly regulated. As many of the tissues involved are not directly accessible, mathematical models have been developed to describe insulin kinetics. This paper presents a mathematical synthesis of models for the study of insulin kinetics and is meant as a supplemental to our recent review of glucose kinetics models, some of which encompass insulin sub-models. Models are described in steady and non-steady state and are grouped into compartmental and non-compartmental schemes.
War of words: the impact of Russian state television on the Russian Internet
Authors: Cottiero Christina , Kucharski Katherine , Olimpieva Evgenia , Orttung Robert W.
Published: March 2015

How effective is Russian state television in framing the conflict in Ukraine that began with the Euromaidan protests and what is its impact on Russian Internet users? We carried out a content analysis of Dmitrii Kiselev's “News of the Week” show, which allowed us to identify the two key frames he used to explain the conflict – World War II-era fascism and anti-Americanism. Since Kiselev often reduces these frames to buzzwords, we were able to track the impact of these words on Internet users by examining search query histories on Yandex and Google and by developing quantitative data to complement our qualitative analysis. Our findings show that much of what state media produces is not effective, but that the “fascist” and anti-American frames have had lasting impacts on Russian Internet users. We argue that it does not make sense to speak of competition between a “television party” and an “Internet party” in Russia since state television has a strong impact in setting the agenda for the Internet and society as a whole. Ultimately, the relationship between television and the Internet in Russia is a continual loop, with each affecting the other.
Making Sense: Dramatherapy with Adults with Asperger's Syndrome
Authors: Porter Rebekah J
Published: March 2015

In search of effective treatment approaches, a service for adults with Asperger's Syndrome funded two brief Dramatherapy pilots comprising individual Dramatherapy sessions for four individuals. This article records and reflects on the results of these pilots. By considering the diagnosis and reviewing the four interventions the article demonstrates that in order to work with the problems presented by Asperger's Syndrome, work must begin with the person so as to release agency with which to approach the problem. Where this is not readily manageable for the individual, Dramatherapy's rich resources become key to the client connecting with themselves, the therapy and their sense of agency.
Generation of specific monoclonal antibodies against the extracellular loops of human claudin-3 by immunizing mice with target-expressing cells
Authors: Ando Hiroshi , Suzuki Masayo , Kato-Nakano Mariko , Kawamoto Shinobu , Misaka Hirofumi , Kimoto Naoya , Furuya Akiko , Nakamura Kazuyasu
Published: March 2015

Human claudin-3 (CLDN3) is a tetraspanin transmembrane protein of tight junction structures and is known to be over-expressed in some malignant tumors. Although a specific monoclonal antibody (MAb) against the extracellular domains of CLDN3 would be a valuable tool, generation of such MAbs has been regarded as difficult using traditional hybridoma techniques, because of the conserved sequence homology of CLDN3s among various species. In addition, high sequence similarity is shared among claudin family members, and potential cross-reactivity of MAb should be evaluated carefully. To overcome these difficulties, we generated CLDN3-expressing Chinese hamster ovary and Sf9 cells to use an immunogens and performed cell-based screening to eliminate cross-reactive antibodies. As a result, we generated MAbs that recognized the extracellular loops of CLDN3 but not those of CLDN4, 5, 6, or 9. Further in vitro studies suggested that the isolated MAbs possessed the desired binding properties for the detection or targeting of CLDN3.
Salivary testosterone and cortisol responses to four different rugby training exercise protocols
Authors: Gaviglio Christopher M. , Osborne Mark , Kelly Vincent G. , Kilduff Liam P. , Cook Christian J.
Published: March 2015

This study assessed the acute response of salivary testosterone and cortisol concentrations to four exercise protocols in 27 elite male rugby players. Each athlete completed four protocols in random order on separate in‐season weeks. Two protocols were resistance training based consisting of four exercises (high pull, bench press, squat and chin‐ups/prone row): Protocol 1 consisted of 5 sets of 15 repetitions at 55% of 1 repetition maximum (1 RM) with 1‐minute rest (5 × 15–55%). Protocol 2 consisted of three sets of five repetitions at 85% 1 RM with 2‐minute rest (3 × 5–85%). Protocol 3 was a strongman (STRNG) session consisting of three stations within a circuit of exercises that included exercises such as battling ropes, prowler push, farmer's walk and tyre flips. Protocol 4 was based on boxing and wrestling inspired exercises (combative – COMB). Salivary testosterone and cortisol concentrations were measured before (PRE) and immediately after exercise (POST). Testosterone did not significantly change as a result of any intervention, whereas cortisol declined and the testosterone to cortisol (T/C) ratio increased significantly in both the 5 × 15–55% and 3 × 5–85% protocol. When results were retrospectively grouped and analysed according to the protocol that demonstrated the greatest absolute testosterone response, significant (P < 0.01) increases for the 5 × 15–55%, STRNG and COMB protocols were observed. The individualised hormone response to exercise observed in this study highlights the importance of recognising a protocol‐dependent approach to training athletes. Furthermore this study also highlights a potential usefulness of employing STRNG and COMB training protocols as an alternative stimulus to resistance training.
Deception in Experiments: Towards Guidelines on use in Applied Economics Research
Authors: Rousu Matthew C. , Colson Gregory , Corrigan Jay R. , Grebitus Carola , Loureiro Maria L.
Published: March 2015

Many applied economics journals ban the use of deception in experiments, which contrasts with the policies in other academic disciplines. We examine the cases for and against deception, and describe the ways deception can be employed in applied economics experiments. We create a general ranking of harms from deception in experiments and present evidence from a survey (conducted in summer 2014) of agricultural and applied economists eliciting attitudes towards ten different deceptive practices. Survey respondents view inflicting physical or psychological harm on participants and not making promised payments as the most severe forms of deception. Less severe forms of deception include providing participants with incomplete product information and conducting an experiment using participants who are not aware they are part of an experiment. Finally, we provide recommendations for policies addressing deception in experiments.
Using pop-up satellite archival tags to inform selectivity in fisheries stock assessment models: a case study for the blue shark in the South Atlantic Ocean
Authors: Carvalho Felipe , Ahrens Robert , Murie Debra , Bigelow Keith , Aires-Da-Silva Alexandre , Maunder Mark N. , Hazin Fábio
Published: March 2015

Selectivity has traditionally been well estimated internally in stock assessment models when length or age composition data are available. However, in stock assessment, temporal or spatial variation in fishery or stock structure can lead to misspecification of the selectivity pattern, which can contribute substantially to the uncertainty in stock assessment results. Consequently, generating auxiliary information to help stock assessment scientists avoid unrealistic specifications of selectivity patterns should be encouraged. Here, we combine data from pop-up satellite archival tags (PSATs) deployed on blue sharks in the South Atlantic Ocean, and information on maximum pelagic longline fishing depths, to introduce an alternative approach for estimating selectivity of fishing gear. Further, we present how this externally estimated tag-based selectivity can be used to inform the most appropriate form of selectivity curves (e.g. asymptotic or dome-shaped) in a spatially structured stock assessment model for the South Atlantic blue shark population. The estimated tag-based selectivity showed substantially different selectivity patterns within the area of the assessed stock, in one area the depth range of the longline gear is inhabited mostly by adults, which is consistent with an asymptotic selectivity. In another area, the overlap shifts to younger ages, with older sharks located in deeper waters, consequently the expected selectivity is more dome-shaped. To account for this variability in the stock assessment model, we assigned fishing fleets with different selectivity patterns. The form of the selectivity curve assigned for each fleet was based on the tag-based selectivity estimates for the area of where that fleet operates. The assessment model demonstrated relatively good fit to the data and that the estimated management quantities were robust. This study provides additional evidence that externally derived estimates of selectivity using PSATs data can assist implementing stock assessments that capture some of the spatial variability of pelagic fish species.
Effect of tailored antibiotic stewardship programmes on the appropriateness of antibiotic prescribing in nursing homes
Authors: van Buul Laura W. , van der Steen Jenny T. , Achterberg Wilco P. , Schellevis François G. , Essink Rob T. G. M. , de Greeff Sabine C. , Natsch Stephanie , Sloane Philip D. , Zimmerman Sheryl , Twisk Jos W. R. , Veenhuizen Ruth B. , Hertogh Cees M. P. M.
Published: March 2015

Objectives

To evaluate the effect of tailored interventions on the appropriateness of decisions to prescribe or withhold antibiotics, antibiotic use and guideline-adherent antibiotic selection in nursing homes (NHs).

Methods

We conducted a quasi-experimental study in 10 NHs in the Netherlands. A participatory action research (PAR) approach was applied, with local stakeholders in charge of selecting tailored interventions based on opportunities for improved antibiotic prescribing that they derived from provided baseline data. An algorithm was used to evaluate the appropriateness of prescribing decisions, based on infections recorded by physicians. Effects of the interventions on the appropriateness of prescribing decisions were analysed with a multilevel logistic regression model. Pharmacy data were used to calculate differences in antibiotic use and recorded infections were used to calculate differences in guideline-adherent antibiotic selection.

Results

The appropriateness of 1059 prescribing decisions was assessed. Adjusting for pre-test differences in the proportion of appropriate prescribing decisions (intervention, 82%; control, 70%), post-test appropriateness did not differ between groups (crude: P = 0.26; adjusted for covariates: P = 0.35). We observed more appropriate prescribing decisions at the start of data collection and before receiving feedback on prescribing behaviour. No changes in antibiotic use or guideline-adherent antibiotic selection were observed in intervention NHs.

Conclusions

The PAR approach, or the way PAR was applied in the study, was not effective in improving antibiotic prescribing behaviour. The study findings suggest that drawing prescribers' attention to prescribing behaviour and monitoring activities, and increasing use of diagnostic resources may be promising interventions to improve antibiotic prescribing in NHs.
A simple mechanism for the anti-glitch observed in AXP 1E 2259+586
Authors: García Federico , Ranea-Sandoval Ignacio F.
Published: March 2015

In this letter, we develop a simple internal mechanism that can account for the recent ‘anti-glitch’ observed for AXP 1E 2259+586 (|Δν/ν| ≳ 10− 7). We propose that the cumulative decay of the internal toroidal magnetic field component will eventually become large enough to turn an originally stable prolate stellar configuration into an unstable one. The subsequent rearrangement of the stellar structure will result in a sudden spin-down of the whole star. We present order-of-magnitude calculations to give confidence to this scenario, using a simple, but physically reasonable, analytical stellar model. We estimate the energy released by the proposed mechanism and show that it is in agreement with the observations. Based on this model, we predict that to achieve the observed sudden spin-down, a minimum magnetar-like value for the magnetic field strength is needed. Consequently, we do not expect this kind of anti-glitch activity to occur in normal pulsars.
Jatrophihabitans soli sp. nov., isolated from soil
Authors: Kim Soo-Jin , Moon Ji-Young , Lim Jun-Muk , Hamada Moriyuki , Ahn Jae-Hyung , Weon Hang-Yeon , Suzuki Ken-ichiro , Kwon Soon-Wo
Published: March 2015

One bacterial strain, designated KIS75-12T, isolated from a soil sample collected from Wonsando island located in Boryeong city, Republic of Korea, was characterized as aerobic, Gram-stain-positive, non-flagellated and a short rod. It grew between temperatures of 15–37 °C, pH 4–9 and 0–3.0 % (w/v) NaCl. The 16S rRNA gene analysis showed the strain was moderately related toJatrophihabitans endophyticusS9-650T(97.7 %) and revealed low sequence similarity (≤94.7 %) with all the other species with validly published names. Its major fatty acid was iso-C16 : 0. The predominant menaquinone of strain KIS75-12Twas MK-9(H4). The polar lipids consisted of diphosphatidylglycerol and several small amounts of phosphatidylinositol, aminolipids and glycolipid. The peptidoglycan containedmeso-A2pm as diagnostic diamino acid and the peptidoglycan type is A4γ. The genomic DNA G+C content of the type strain was 72.1 mol%. The combined phenotypic, chemotaxonomic and phylogenetic data showed that strain KIS75-12Tcould be clearly distinguished from the only member of the genusJatrophihabitans,J. endophyticus. Therefore, the results of this study indicate the existence of a representative of a novel species of the genusJatrophihabitans, for which we propose the nameJatrophihabitans solisp. nov., with strain KIS75-12T( = KACC 17298T = DSM 45908T =  NBRC 109658T) as the type strain. An emended description of the genusJatrophihabitansis also given.
Microbacterium proteolyticum sp. nov. isolated from roots of Halimione portulacoides
Authors: Alves Artur , Riesco Raúl , Correia António , Trujillo Martha E.
Published: March 2015

An endophytic actinobacterial strain RZ36T, isolated from roots of the salt-marsh plantHalimione portulacoides, was subjected to a polyphasic taxonomic characterization. 16S rRNA gene sequence analysis revealed that this strain belonged to the genusMicrobacterium. The closest phylogenetic relative wasMicrobacterium hominisDSM 12509T, with a pairwise 16S rRNA gene sequence similarity of 98.8 %. The DNA–DNA hybridization value between strain RZ36TandM. hominisDSM 12509Twas 16 %. The affiliation to the genusMicrobacteriumwas corroborated by phenotypic and chemotaxonomic characteristics. The cell-wall peptidoglycan type was B2β and the diagnostic diamino acid was ornithine. Whole-cell sugars detected were galactose, glucose, rhamnose, ribose and xylose. The major fatty acids were anteiso-C15 : 0and iso-C16 : 0and the major menaquinone was MK-11 (64 %). Main polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and two unknown glycolipids. The genomic DNA G+C content was 69.7 mol%. Thus, on the basis of phenotypic, genotypic and chemotaxonomic data, strain RZ36Tis considered to represent a novel species of the genusMicrobacterium, for which the nameMicrobacterium proteolyticumsp. nov. (type strain RZ36T = DSM 27100T = CECT 8356T) is proposed.
Klebsiella Pneumoniae Liver Abscesses and A Distinct Invasive Syndrome: Case Reports and Review of The Literature
Authors: Gillies Jenna , Inkster Teresa
Published: March 2015

Introduction:

Over the past 20 years there has been an increasing awareness of a distinct invasive clinical syndrome caused byKlebsiella pneumoniaein patients from Asian descent.

Case presentation:

Here we report two cases of invasiveK.pneumoniaeinfection in Asian patients who both presented in Glasgow, UK, with liver abscesses within a 6‐month period.

Conclusion:

Clinicians should be vigilant for mucoid strains ofK. pneumoniaeisolated from patients with liver abscesses of Asian descent and thorough in their investigation for metastatic complications.
Successful ceftolozane/tazobactam treatment of chronic pulmonary infection with pan‐resistant Pseudomonas aeruginosa
Authors: Soliman Reham , Lynch Sarah , Meader Emma , Pike Rachel , Turton Jane F. , Hill Robert L. R. , Woodford Neil , Livermore David M.
Published: March 2015

Introduction:

The treatment of chronic Pseudomonas aeruginosa infections is challenging, with resistance and antibiogram diversity accumulating during successive therapies. Some isolates are resistant to all licensed agents, creating treatment problems and an urgent need for new therapies. Among antibiotics in advanced development, ceftolozane/tazobactam has potent in vitro antipseudomonal activity, with low MICs even for strains with AmpC β‐lactamase‐, impermeability‐ and efflux‐mediated resistance to other β‐lactams.

Case presentation:

A bronchiectasis exacerbation in a 59‐year‐old man involved pan‐resistant P. aeruginosa. Meropenem/colistin therapy failed. Named‐patient ceftolozane/tazobactam 2+1 g every 8 h for 14 days restored baseline respiratory and inflammatory marker status, and the patient was discharged; the ceftolozane/tazobactam MIC was 8 µg ml−1, with most growth inhibited at 2 µg ml−1.

Conclusion:

A positive outcome in this difficult infection due to an otherwise pan‐resistant P. aeruginosa is notable, especially as the patient had failed prior therapy with other agents. We urge formal evaluation of ceftolozane/tazobactam in chronic pseudomonal lung infections.
The origins of a novel butterfly wing patterning gene from within a family of conserved cell cycle regulators
Authors: Nadeau Nicola J. , Pardo-Diaz Carolina , Whibley Annabel , Supple Megan , Wallbank Richard , Wu Grace C. , Maroja Luana , Ferguson Laura , Hines Heather , Salazar Camilo , ffrench-Constant Richard , Joron Mathieu , Owen McMillan W. , Jiggins Chris D.
Published: March 2015

A major challenge in evolutionary biology is to understand the origins of novel structures. The wing patterns of butterflies and moths are derived phenotypes unique to the Lepidoptera. Here we identify a gene that we namepoikilomousa(poik), which regulates colour pattern switches in the mimeticHeliconiusbutterflies. Strong associations between phenotypic variation and DNA sequence variation are seen in three differentHeliconiusspecies, in addition to associations between gene expression and colour pattern. Colour pattern variants are also associated with differences in splicing ofpoiktranscripts.poikis a member of the conserved fizzy family of cell cycle regulators. It belongs to a faster evolving subfamily, the closest functionally characterised orthologue being thecortexgene inDrosophila,a female germ-line specific protein involved in meiosis.poikappears to have adopted a novel function in the Lepidoptera and become a major target for natural selection acting on colour and pattern variation in this group.
Crystal structure ofcatena-poly[[silver(I)-{μ-2,6-bis[(1H-pyrazol-1-yl)methyl]pyridine-κ3N1,N2:N2′}] nitrate]
Authors: Kim Daeyoung , Kang Sung Kwon
Published: March 2015

In the title complex, {[Ag(C13H13N5)]NO3}n, the AgIatom is coordinated by three N atoms from two bidentate/monodentate pyrazolylpyridyl ligands to form a distorted trigonal–planar geometry [range of angles: 83.34 (6) (chelate ring) to 139.15 (7) °]. The chelate ring has a distorted boat conformation. The dihedral angle between the pyridyl ring and the coordinating pyrazolyl ring is 67.22 (6)°. The non-coordinating pyrazolyl ring is twisted by 62.97 (7)° from the pyridyl ring. In the crystal, the complex cations are arranged in polymeric chains along thec-axis direction, with the nitrate counter-anions situated in between. Weak C—H...O hydrogen bonds link the ions into a three-dimensional network.
Crystal structure of 4-azidomethyl-6-isopropyl-2H-chromen-2-one
Authors: Krishnamurthy M. S. , Begum Noor Shahina , Shamala D. , Shivashankar K.
Published: March 2015

In the title molecule, C13H13N3O2, the benzopyran ring system is essentially planar, with a maximum deviation of 0.017 (1) Å. In the crystal, weak C—H...O hydrogen bonds link molecules into ladders along [010]. In addition, π–π interactions between inversion-related molecules, with centroid–centroid distances in the range 3.679 (2)–3.876 (2) Å, complete a two-dimensional network parallel to (001).
Contingency modelling for construction projects using fuzzy-set theory
Authors: Salah Ahmad , Moselhi Osama
Published: March 2015

Purpose

– The purpose of this paper is to present a newly developed fuzzy-set based model for estimating, allocating, depleting, and managing contingency fund over the life cycle of construction projects.

Design/methodology/approach

– Fuzzy set theory is utilized in the design and development of proposed contingency modelling framework to incorporate uncertainties associated with the development phases of construction projects. A set of developed indices, measures, and ratios are introduced to quantify and characterize these uncertainties. The developed framework is designed to incorporate expert opinion and provide user-system interaction.

Findings

– The results obtained from the application of the developed framework on actual project case not only illustrate its accuracy, but also demonstrate its capabilities for contingency management over life cycle of construction projects. Unlike other methods, the framework provides project managers with structured method for contingency depletion utilizing a set of depletion curves and selection factors.

Originality/value

– The novelty of the developed framework lies not only in its new developments for contingency estimating but also its modelling for contingency allocation and depletion. It is expected to be of direct value to industry professionals and academics interested in contingency management over the entire life cycle of construction projects. The proposed framework provides management functions and features beyond those generated through Monte Carlo simulation and even those developed using fuzzy set theory.
Effect of adoption of relational contracting practices on relationship quality in public projects in Singapore
Authors: Ling Florence Y.Y. , Tan Peng Chong , Ning Yan , Teo Albert , Gunawansa Asanga
Published: March 2015

Purpose

– The purpose of this paper is to investigate relational contracting (RC) practices that give rise to higher quality interpersonal relations between these pairs of stakeholders at the end of public projects: clients and contractors; contractors and consultants; and clients and consultants. It developed models to predict the level of quality of interpersonal relations between the stakeholders at the completion of public projects.

Design/methodology/approach

– Using a set of questionnaire, data were collected from randomly selected construction industry practitioners who have had experience in public projects in Singapore. The data were analysed to identify association between the use of RC practices and quality of interpersonal relations between stakeholders. In-depth interviews with experts were conducted.

Findings

– It was found that when certain RC practices were adopted to a larger extent, public projects also have significantly higher quality of interpersonal relations between clients, contractors and consultants. Three mathematical models were developed to predict the relationship quality between stakeholders at the end of the public project.

Research limitations/implications

– The limitations include the subjective nature of the Likert scale that was used in answering the questionnaire survey and the limited number of interviews. The effect of existing good relations among stakeholders was not taken into account.

Practical implications

– Suitable RC practices for adoption by public clients, contractors and consultants in public projects are recommended. These include developing deeper mutual trust and understanding, sharing project information, and having real gain-share/pain-share among contracting parties.

Originality/value

– RC practices that are significantly associated with relationships among contracting parties in public projects in Singapore are uncovered. Contracting parties may use the recommendations to help enhance their relationships with one another in a public project.
Challenges in recruiting hard-to-reach populations focusing on Latin American recent immigrants
Authors: Vahabi Mandana , Isaacs Sandra , Koc Mustafa , Damba Cynthia
Published: March 2015

Purpose

– Recruiting immigrant populations, particularly recent arrivals, is challenging due to lack of sampling frames and other factors. The purpose of this paper is to report the feasibility of using a quasi-random sampling strategy for recruiting recent Latin American (LA) immigrants.

Design/methodology/approach

– The initial recruitment strategy included random selection of two census tracts (CTs) with high concentrations and numbers of recent LAs in Toronto, and door-to-door recruitment. Based on challenges encountered this strategy was modified by consulting trusted community members and recruiting participants residing in selected CTs using cultural venues.

Findings

– Door-to-door recruitment of the target group is difficult. Challenges included accessing individuals living in apartment buildings, lack of trust and fear of deportation, transitory residency, and difficulty recruiting very recent arrivals. The modified strategy was more efficient and yielded higher recruitment rates, and was more acceptable to participants.

Research limitations/implications

– The limited timeframe of the study and lack of timely census data may have prevented full exploration of study methodologies.

Originality/value

– The study demonstrated that recruitment rates of recent immigrants and refugees can be improved by randomly selecting CTs with high concentrations and numbers of recent immigrants and using culturally appropriate recruitment strategies. These groups may not be homogeneously distributed in selected geographic areas (e.g. CTs); it may be necessary to focus on pockets of high concentration as identified by community members who are familiar with the area.