bluuebunny/crossref_metadata_2025 huggingface dataset:
Cosine faded harmonics binary offset carrier modulation for next‐generation GNSS
Authors: Liu Wei , Hu Yuan
Published: November 2015

A new family of faded harmonics modulations, cosine faded harmonics binary offset carrier modulations (FH‐BOCcos), is designed to account for the spectral overlap among global navigation satellite system (GNSS) signals. The generalised mathematical model and power spectral density function of FH‐BOCcos modulation are established. The spectral characteristics and modulation parameters are also analysed. The proposed modulations can suppress specific sidelobes of the spectrum while retaining similar signal performance compared with traditional BOC modulation.
Performance evaluation of broken gap Esaki tunnel diodes on Si and GaSb substrates
Authors: Thomas P.M. , Filmer M.J. , Gaur A. , Rommel S.L. , Bhatnagar K. , Droopad R.
Published: November 2015

n‐InAs/p‐GaSb Esaki diodes with 3 nm GaSb i‐layers are fabricated on Si and GaSb substrates. The on Si sample devices exhibit lower peak to valley ratios and peak current density than their on GaSb counterparts at 3.27 against 4.45 and 119 against 336 kA/cm2, respectively. The findings are similar to other reports of integrating III–V Esaki diodes onto Si.
Bandwidth enhancement of compact monopole antenna with triple band rejections
Authors: Li Tong , Zhu Cheng , Cao Xiangyu , Gao Jun
Published: November 2015

A compact monopole antenna with enhanced bandwidth and triple band rejections for ultra‐wideband applications is presented. The base of the proposed antenna is a semicircular patch which is fed by a modified tapered coplanar waveguide line. By using the trident‐shaped feed line, much wider impedance bandwidth is obtained. To avoid potential interferences, two trapezoid stubs and a C‐shaped stub are printed on the back surface of the substrate and are connected to the antenna through three vias. The proposed antenna is practically fabricated with a compact size of 20 × 24 mm2. Good agreement is achieved between the simulation and measurement, which shows that the proposed antenna offers a very wide bandwidth from 3.02 to 20.8 GHz (149%) with triple band rejections covering the 3.5 GHz WiMAX and 5.2/5.8 GHz WLAN bands.
High dynamic range single channel sampling of wideband RF signals using ultra‐fast nanoscale photoconductive switching
Authors: Tripon‐Canseliet C. , Zegaoui M. , Jestin G. , Coinon C. , Berger P. , Baili G. , Descamps‐Mandine A. , Maksimovic I. , Decoster D. , Hodé J.M. , Dolfi D. , Chazelas J.
Published: November 2015

This Letter reports on new experimental high dynamic range sub‐sampling performances obtained from nanoscale microwave photoconductive switches operating under a 0.8 µm wavelength pulsed illumination. Experimental results have been performed on different samples benefiting of a low temperature grown Gallium Arsenide absorbing layer on GaAs substrate, coplanar microwave electrode profile optimisation, and the use of an ultra‐low noise jitter optical source delivering optical pulses of 1 to10 ps pulse width at a 2 GHz repetition frequency at 0.8 µm optical wavelength. Thanks to carrier lifetime tunability achievement from 1 to 20 ps, in association with a carrier mobility of 3900 cm²/V.s, experimental demonstrations of 54 and 45 dB signal‐to‐noise ratio microwave signal sampling for signals at 5,76 and 20 GHz frequency bandwidth respectively confirms submicron devices functionality as a new class of single channel photonic analogue to digital converters.
Antenna selection for reduction of Rician distributed self‐interference effects in full duplex radio
Authors: Narieda S.
Published: November 2015

This Letter presents an antenna selection criterion to reduce Rician distributed self‐interference (SI) effects in full duplex radio. The presented criterion can minimise the effects of residual SI, which is caused by channel estimation errors, by maximising the desired signal power to the residual SI and the noise ratio. The presented approach using numerical examples is verified.
Very large bandwidth continuous time analogue equaliser in InP DHBT for beyond‐100 GBd optical communication applications
Authors: Mettetal R. , Dupuy J.‐Y. , Jorge F. , Riet M. , Nodjiadjim V. , Konczykowska A. , Ouslimani A.
Published: November 2015

The study, design and measurement of a continuous time analogue equaliser based on a differential cascode amplifier cell, using indium phosphide double heterojunction bipolar transistors (DHBTs) reaching an fT/fmax of 370/340 GHz are reported. A bandwidth of more than 110 GHz is achieved and a peaking of 18 dB at 95 GHz is reached. Simulations demonstrated an equalisation at 205 Gbit/s. This is believed to be the highest frequency peaking reported to date.
Economic power transaction using coalitional game strategy in micro‐grids
Authors: Ni Jianmo , Ai Qian
Published: November 2015

Due to the uncontrollability of renewable energy resources, micro‐grids (MGs) often have to exchange excessive or insufficient power with the utility grid in traditional non‐cooperative mode. In contrast, power transaction considering direct energy trading between MGs has been considered as a promising method to improve economic efficiency. Specifically, MGs with complementary power surplus or shortage have an incentive to cooperate with each other and perform direct trading due to lower costs and power losses. In this study, the authors focus on comprehensive economic power transaction of the multiple MGs network with multi‐agent system. A three‐stage algorithm based on coalitional game strategy is proposed consisting of request exchange stage, merge‐and‐split stage and cooperative transaction stage. The developed algorithm enables MGs to form coalitions, where each MG can exchange power directly by paying a transmission fee. With local power transaction, MGs can minimise their expenditures comprising the generation costs, transmission costs, power losses and load shedding compensation; hence, ensure the cost efficiency of the whole MGs network. Moreover, the implementation of load shedding is discussed and its benefit is demonstrated. Simulation results show that the proposed cooperative scheme significantly reduces the total cost of MGs compared with the non‐cooperative method.
Parallel resultant elimination algorithm to solve the selective harmonic elimination problem
Authors: Yang Kehu , Chen Liangyu , Zhang Jianjun , Hao Jun , Yu Wensheng
Published: November 2015

Although the resultant elimination method can get all the possible solutions for the selective harmonic elimination (SHE) problem without the selection of initial values, it still has some fatal shortcomings, such as the high computation burden and the huge memory consumption caused by the intermediate expression swell in the procedure of computing the symbolic determinant of the Sylvester matrix. On the basis of the principle of polynomial interpolation, an algorithm framework is proposed to compute the resultant polynomials, which contains the following two major steps: the evaluation of numerical interpolation points and the solution of linear equations. This approach avoids symbolic computing whose computation complexity is usually very high, furthermore, both of these two steps are suitable for parallel implementing which can speed up the computing tremendously. By using the extended n‐dimensional Björck–Pereyra's algorithm, this algorithm framework is implemented on a parallel computing system, and it has been used to solve the SHE equations for two‐level, three‐level, and multilevel inverters. As all the possible solutions can be found by this algorithm, the optimal solutions which have the lowest total harmonic distortion can be identified. Experiment results verify the correctness and effectiveness of the proposed method.
Detection of reverse recovery characteristics of power diodes
Authors: Wei Wensheng , Luo Fei , Zhang Chunxi , Shen Qi
Published: November 2015

A setup was constituted for measuring reverse recovery (RR) waveforms of current Irr and voltage Vrr, RR time trr, RR charges Qrr, as well as the ratio C of absolute value of RR peak voltage Vrm to amplitude of reverse biased pulse voltage Vr and so on, for power device under test (DUT). Forward pulse current If and the Vr were generated from a central processing unit (CPU). Amplitude of If was magnified by a transistor, while the scale was regulated via a Darlington array controlling relays for altering different resistors connected to emitter of the transistor to apply on DUT. Pulse of Vr was first shaped by a Schmitt trigger and then was magnified by a metal–oxide–semiconductor field‐effect transistor (MOSFET), while the edge commutating rate dIf/dt was adjusted through the Darlington controlling relays for changing different inductors linked to drain of the MOSFET to bias on DUT. The waveforms can be observed with an oscilloscope and sampled for further digitally processing. Inputting test parameters via keyboard, calculating and displaying of test results can be controlled by a host CPU. The parameters and metering results can be monitored by a liquid crystal displayer (LCD).
Comment on “Comment on ‘Superposition of elliptic functions as solutions for a large number of nonlinear equations”’ [J. Math. Phys. 56, 084101 (2015)]
Authors: Abraham-Shrauner Barbara
Published: November 2015

The assertion in a theorem that the superposition of two particular Jacobian elliptic functions is not a solution of the nonlinear Schrodinger equation is demonstrated to be invalid.
Emittance study of a 28 GHz electron cyclotron resonance ion source for the Rare Isotope Science Project superconducting linear accelerator
Authors: Park Bum-Sik , Hong In-Seok , Jang Ji-Ho , Jin Hyunchang , Choi Sukjin , Kim Yonghwan
Published: November 2015

A 28 GHz electron cyclotron resonance (ECR) ion source is being developed for use as an injector for the superconducting linear accelerator of the Rare Isotope Science Project. Beam extraction from the ECR ion source has been simulated using the KOBRA3-INP software. The simulation software can calculate charged particle trajectories in three dimensional complex magnetic field structures, which in this case are formed by the arrangement of five superconducting magnets. In this study, the beam emittance is simulated to understand the effects of plasma potential, mass-to-charge ratio, and spatial distribution. The results of these simulations and their comparison to experimental results are presented in this paper.
Understanding defect distributions in polythiophenes via comparison of regioregular and regiorandom species
Authors: Muntasir Tanvir , Chaudhary Sumit
Published: November 2015

Organic photovoltaics (OPVs) are regarded as promising for solar-electric conversion with steadily improving power conversion efficiencies. For further progress, it is crucial to understand and mitigate defect states (traps) residing in the band-gap of OPV materials. In this work, using capacitance measurements, we analyzed two major bands in the density of states (DOS) energy spectra of defects in poly(3-hexylthiophene) (P3HT); regio-regular and regio-random species of P3HT were compared to elucidate the role of morphological disorder. To accurately interpret the obtained DOS profile, trap emission prefactors and activation energy were extracted from temperature dependent capacitance-frequency measurements, while doping, Fermi energy, built-in voltage, and energy levels of the defects were extracted from capacitance-voltage measurements. We identified that the lower energy band—misinterpreted in literature as a defect distribution—stems from free carrier response. The higher energy defect distribution band for regio-random P3HT was an order of magnitude higher than region-regular P3HT, thus stemming from morphological disorder. Impedance spectroscopy was also employed for further comparison of the two P3HT species.
Optimal design and verification tests of cycloidal vertical axis wind turbine
Authors: Lee Choong Hee , Min Seung Yong , Park Cheon Jin , Kim Seung Jo
Published: November 2015

In this paper, research describing a high-efficiency vertical axis wind turbine (VAWT) system is presented. The proposed cycloidal vertical axis wind turbine (CWT) is straight-bladed; adopting the cycloidal blade system that is used as the propulsion system in a cyclocopter. The CWT actively controls the pitch angle of its rotor blades to improve turbine efficiency according to wind conditions. It can self-start by changing its pitch angle pattern and is able to achieve maximum operating efficiency. An optimization scheme based on the response surface method was used to find the most efficient design variables while performing computational fluid dynamics (CFD) analysis with variables including the number of blades, chord length, tip speed ratio, and maximum pitch angle. For the experiments, a 600 W (at 10 m/s of wind speed) class cycloidal VAWT was designed and developed. Two types of experiments were carried out and compared with the CFD results. The first test was a constant wind speed test. The constant wind speed was achieved by driving a truck at constant speed along a straight road with the CWT mounted on the truck. The second test was a field test that was conducted in a certification test site for small wind turbine systems at the Korea Institute of Energy Research in Jeju Island. The result of the constant wind speed test verified the CFD analysis and the field test demonstrated its reliability. Furthermore, another CWT with a flap control device is added in the tip of blades is also studied and designed for the highest efficiency. The flap control device, operated with simple mechanical linkages, can transform the blade airfoil's camber between positive and negative.
Effects of residual hydrogen in sputtering atmosphere on structures and properties of amorphous In-Ga-Zn-O thin films
Authors: Tang Haochun , Ishikawa Kyohei , Ide Keisuke , Hiramatsu Hidenori , Ueda Shigenori , Ohashi Naoki , Kumomi Hideya , Hosono Hideo , Kamiya Toshio
Published: November 2015

We investigated the effects of residual hydrogen in sputtering atmosphere on subgap states and carrier transport in amorphous In-Ga-Zn-O (a-IGZO) using two sputtering systems with different base pressures of ∼10−4 and 10−7 Pa (standard (STD) and ultrahigh vacuum (UHV) sputtering, respectively), which produce a-IGZO films with impurity hydrogen contents at the orders of 1020 and 1019 cm−3, respectively. Several subgap states were observed by hard X-ray photoemission spectroscopy, i.e., peak-shape near-valence band maximum (near-VBM) states, shoulder-shape near-VBM states, peak-shape near-conduction band minimum (near-CBM) states, and step-wise near-CBM states. It was confirmed that the formation of these subgap states were affected strongly by the residual hydrogen (possibly H2O). The step-wise near-CBM states were observed only in the STD films deposited without O2 gas flow and attributed to metallic In. Such step-wise near-CBM state was not detected in the other films including the UHV films even deposited without O2 flow, substantiating that the metallic In is segregated by the strong reduction effect of the hydrogen/H2O. Similarly, the density of the near-VBM states was very high for the STD films deposited without O2. These films had low film density and are consistent with a model that voids in the amorphous structure form a part of the near-VBM states. On the other hand, the UHV films had high film densities and much less near-VBM states, keeping the possibility that some of the near-VBM states, in particular, of the peak-shape ones, originate from –OH and weakly bonded oxygen. These results indicate that 2% of excess O2 flow is required for the STD sputtering to compensate the effects of the residual hydrogen/H2O. The high-density near-VBM states and the metallic In segregation deteriorated the electron mobility to 0.4 cm2/(V s).
Enhanced Catalytic Activity of Carbon Nanotubes for the Oxidation of Cyclohexane by Filling with Fe, Ni, and FeNi alloy Nanowires
Authors: Yang Xixian , Li Yuhang , Yu Hao , Gui Xuchun , Wang Hongjuan , Huang Hongyu , Peng Feng
Published: November 2015

Fe-, Ni-, and alloyed FeNi-filled carbon nanotubes (Fe@CNT, Ni@CNT, and FeNi@CNT) were prepared by a general strategy using a mixture of xylene and dichlorobenzene as carbon source, and ferrocene, nickelocene, and their mixture as catalysts. By tailoring the composition of the carbon precursor, the filling ratio and the wall thickness of metal@CNT could be controlled. For the catalytic oxidation of cyclohexane in liquid phase with molecular oxygen as oxidant, the highest activity was obtained over Fe@CNT synthesized from pure dichlorobenzene. However, Ni filling did not improve the activity of CNTs. The effects of metal filling, wall thickness, and defects on catalytic activity were investigated to determine the structure–activity relationship of the filled CNTs. The enhanced catalytic performance can be attributed to a combined contribution of thin walls of CNTs and confined electron-donating metals, which are favourable to electron transfer on the surfaces of CNTs. The modification of the electronic structure of CNTs upon Fe and Ni fillers insertion was elucidated through density functional theory calculations.
A diagnostic framework for biodiversity conservation institutions
Authors: Clement Sarah , Moore Susan A. , Lockwood Michael , Morrison Tiffany H.
Published: November 2015

Biodiversity loss is a critical issue on the environmental agenda, with species-based approaches failing to stem the decline. Landscape-scale approaches offer promise, but require institutional change. This article describes a novel conceptual framework for assessing institutional arrangements to tackle this persistent problem. In doing so, two critical issues for biodiversity governance are addressed. The first is a need to enrich largely theoretical descriptions of adaptive governance by considering how the practical realities of institutional environments (e.g. public agencies) limit achievement of an adaptive governance ‘ideal’. The second is enabling explicit consideration of the unique aspects of biodiversity as a ‘policy problem’ in the analysis of institutional arrangements. The framework contributes to efforts to design more adaptive institutional arrangements, through supporting a more sophisticated and grounded institutional analysis incorporating insights from institutional theory, especially literature on organisational environments and public administration. Concepts from Pragmatism also contribute to this grounding, providing insight into how public agencies can play a more productive role in biodiversity conservation and building public consent for management actions. The diagnostic categories in the framework include the attributes of the biodiversity problem and the involved players; the political context; and practices contributing to both competence and capacity. Guidance on how to apply the framework and an example of its application in Australia illustrate the utility of this tool for institutional diagnosis and design. Development of this diagnostic framework could be further enhanced by empirically informed elaboration of the relationships between its components, and of the nature of, and factors influencing, key concerns for adaptation, particularly learning, self-organising and buffering.
Sociodemographic correlates of smoking in pregnancy and antenatal-care attendance in Indigenous and non-Indigenous women in South Australia
Authors: Mittiga C. , Ettridge K. , Martin K. , Tucker G. , Dubyna R. , Catcheside B. , Scheil W. , Maksimovic L.
Published: November 2015

Smoking in pregnancy is a key health issue in Australia, particularly among Indigenous women. However, few studies have examined the sociodemographic factors associated with smoking in pregnancy or the predictors of antenatal-care attendance among Indigenous and non-Indigenous Australian women who smoke. Data from the South Australian perinatal statistics collection of all births from 2000–2010 (n=197538) were analysed separately by Indigenous status to determine the sociodemographic factors associated with smoking in pregnancy and antenatal-care attendance by women who smoke. For Indigenous and non-Indigenous women, smoking in pregnancy was significantly independently associated with socioeconomic disadvantage, residing in regional or remote areas, increased parity, unemployment, being a public patient and attending fewer antenatal care visits. Smoking in pregnancy was associated with younger age and not being partnered only for non-Indigenous women. For Indigenous and non-Indigenous pregnant women who smoked, antenatal-care attendance was lower among women who were of younger age, higher parity, unemployed and not partnered. Differences in attendance within sociodemographic factors were greater for Indigenous women. Therefore, while sociodemographic correlates of smoking in pregnancy and antenatal-care attendance are largely similar for Indigenous and non-Indigenous women, tailored cessation and antenatal-care programs that reflect the differences in sociodemographic groups most at risk may be beneficial.
Using the photoload technique with double sampling to improve surface fuel loading estimates
Authors: Tinkham Wade T. , Hoffman Chad M. , Canfield Jesse M. , Vakili Emma , Reich Robin M.
Published: November 2015

Accurate surface fuel load estimates based on the planar intercept method require a considerable amount of time and cost. Recently the photoload method has been proposed as an alternative for sampling of fine woody surface fuels. To evaluate the use of photoload fuel sampling, six simulated fuel beds of 100 photoload visual estimates and destructively sampled fuel loads were generated at three levels of fuel loading (0.016, 0.060, and 0.120  kg  m–2) and two levels of variability (coefficients of variation of ~42 and 85%). We assessed the accuracy and precision of simple random sampling with and without double sampling on surface fuel load estimation. Direct visual estimates often overestimated fuel loads where actual fuel loading was low and underestimated fuel loads where fuel loads were large. We found that double sampling with a classical regression estimation approach provided the most accurate and precise fuel load estimates, substantially improving the accuracy and precision achieved over standard photoload estimation when ń ≥ 20 and double sampling rate ≥20%. These results indicate that fine woody fuel loading estimation with the photoload technique can be improved by incorporating a double sampling approach.
Understanding the physiology of the asymptomatic diaphragm of the M1592V hyperkalemic periodic paralysis mouse
Authors: Ammar Tarek , Lin Wei , Higgins Amanda , Hayward Lawrence J. , Renaud Jean-Marc
Published: November 2015

The diaphragm muscle of hyperkalemic periodic paralysis (HyperKPP) patients and of the M1592V HyperKPP mouse model rarely suffers from the myotonic and paralytic symptoms that occur in limb muscles. Enigmatically, HyperKPP diaphragm expresses the mutant NaV1.4 channel and, more importantly, has an abnormally high Na+ influx similar to that in extensor digitorum longus (EDL) and soleus, two hindlimb muscles suffering from the robust HyperKPP abnormalities. The objective was to uncover the physiological mechanisms that render HyperKPP diaphragm asymptomatic. A first mechanism involves efficient maintenance of resting membrane polarization in HyperKPP diaphragm at various extracellular K+ concentrations compared with larger membrane depolarizations in HyperKPP EDL and soleus. The improved resting membrane potential (EM) results from significantly increased Na+ K+ pump electrogenic activity, and not from an increased protein content. Action potential amplitude was greater in HyperKPP diaphragm than in HyperKPP soleus and EDL, providing a second mechanism for the asymptomatic behavior of the HyperKPP diaphragm. One suggested mechanism for the greater action potential amplitude is lower intracellular Na+ concentration because of greater Na+ K+ pump activity, allowing better Na+ current during the action potential depolarization phase. Finally, HyperKPP diaphragm had a greater capacity to generate force at depolarized EM compared with wild-type diaphragm. Action potential amplitude was not different between wild-type and HyperKPP diaphragm. There was also no evidence for an increased activity of the Na+–Ca2+ exchanger working in the reverse mode in the HyperKPP diaphragm compared with the wild-type diaphragm. So, a third mechanism remains to be elucidated to fully understand how HyperKPP diaphragm generates more force compared with wild type. Although the mechanism for the greater force at depolarized resting EM remains to be determined, this study provides support for the modulation of the Na+ K+ pump as a component of therapy to alleviate weakness in HyperKPP.
Temporal development of coastal ecosystems in the Baltic Sea over the past two decades
Authors: Olsson Jens , Tomczak Maciej T. , Ojaveer Henn , Gårdmark Anna , Põllumäe Arno , Müller-Karulis Bärbel , Ustups Didzis , Dinesen Grete E. , Peltonen Heikki , Putnis Ivars , Szymanek Lena , Simm Mart , Heikinheimo Outi , Gasyukov Pavel , Axe Philip , Bergström Lena
Published: November 2015

Coastal areas are among the most biologically productive aquatic systems worldwide, but face strong and variable anthropogenic pressures. Few studies have, however, addressed the temporal development of coastal ecosystems in an integrated context. This study represents an assessment of the development over time in 13 coastal ecosystems in the Baltic Sea region during the past two decades. The study covers between two to six trophic levels per system and time-series dating back to the early 1990s. We applied multivariate analyses to assess the temporal development of biological ecosystem components and relate these to potential driving variables associated with changes in climate, hydrology, nutrient status, and fishing pressure. Our results show that structural change often occurred with similar timing in the assessed coastal systems. Moreover, in 10 of the 13 systems, a directional development of the ecosystem components was observed. The variables representing key ecosystem components generally differed across systems, due to natural differences and limitation to available data. As a result of this, the correlation between the temporal development of the biological components in each area and the driving variables assessed was to some extent area-specific. However, change in nutrient status was a common denominator of the variables most often associated with changes in the assessed systems. Our results, additionally, indicate existing strengths as well as future challenges in the capacity of currently available monitoring data to support integrated assessments and the implementation of an integrated ecosystem-based approach to the management of the Baltic Sea coastal ecosystems.
CXCR6 regulates the recruitment of pro-inflammatory IL-17A-producing T cells into atherosclerotic aortas
Authors: Butcher Matthew J. , Wu Chih-I , Waseem Tayab , Galkina Elena V.
Published: November 2015

The adaptive immune response is involved in the development and progression of atherosclerosis and IL-17A+ cells play a role in this disease. Although elevated number of CD4+ IL-17A+ (Th17) and IL-17A+TCRγδ+ T cells are found within murine atherosclerotic aortas and human plaques, the mechanisms governing IL-17A+ T-cell migration to atherosclerotic lesions are unclear. The chemokine receptor CXCR6 is expressed on several T-cell subsets and plays a pro-atherogenic role in atherosclerosis. Here, we used CXCR6-deficient (Cxcr6GFP/GFP) apolipoprotein E-deficient (Apoe−/−) mice to investigate the involvement of CXCR6 in the recruitment IL-17A+ T cells to atherosclerotic aortas. Flow cytometric analyses revealed reductions in Th17 and IL-17A+TCRγδ+ T cells within aged Cxcr6GFP/GFPApoe−/− aortas, in comparison with age-matched Cxcr6GFP/+Apoe−/− aortas. Although CXCR6-sufficient IL-17A+ T cells efficiently migrated toward CXCL16, the migration of CXCR6-deficient IL-17A+ T cells was abolished in transwell assays. Importantly, the recruitment of Cxcr6GFP/GFPApoe−/− IL-17A+ T cells into the aortas of Apoe−/− recipients was markedly reduced in short-term adoptive transfer experiments. Altogether these results demonstrate an important role of CXCR6 in the regulation of pathological Th17 and IL-17A+TCRγδ+ T-cell recruitment into atherosclerotic lesions.
Two Independent and Highly Efficient Open Source TKF91 Implementations
Authors: Baudis Nikolai , Barbera Pierre , Graf Sebastian , Lutteropp Sarah , Opitz Daniel , Flouri Tomáš , Stamatakis Alexandros
Published: November 2015

In the context of a master level programming practical at the computer science department of the Karlsruhe Institute of Technology, we developed and make available two independent and highly optimized open-source implementations for the pair-wise statistical alignment model, also known as TKF91, that was developed by Thorne, Kishino, and Felsenstein in 1991. This paper has two parts. In the educational part, we cover teaching issues regarding the setup of the course and the practical and summarize student and teacher experiences. In the scientific part, the two student teams (Team I: Nikolai, Sebastian, Daniel; Team II: Sarah, Pierre) present their solutions for implementing efficient and numerically stable implementations of the TKF91 algorithm. The two teams worked independently on implementing the same algorithm. Hence, since the implementations yield identical results —with slight numerical deviations— we are confident that the implementations are correct. We describe the optimizations applied and make them available as open-source codes in the hope that our findings and software will be useful to the community as well as for similar programming practicals at other universities.
Stimulation of neuronal cells by culture supernatant of T lymphocytes triggered by anti‐CD3 mAb followed by propagation in the presence of interleukin‐2
Authors: Ishiguro Masae , Okada Alan , Asai Kiyofumi , Kojima Kiyohide , Okada Hidechika
Published: November 2015

Performance status (PS) frequently improves occurs in cancer patients who have been infused with their own lymphokine‐activated killer T cells (LAK‐T). In the present study, a culture supernatant of LAK‐T (LAK‐T sup) administered to 8‐week‐old rats caused neurogenesis as evidenced by increased 5‐ethynyl‐2′‐deoxyuridine staining of brain tissues. Intravenous injection of granulocyte‐macrophage colony stimulating factor (GM‐CSF), a major cytokine in LAK‐T sup, had a similar effect. Furthermore, LAK‐T sup induced Ca++ increase in rat hippocampal brain slices that was detected in neuronal cells by emission of Fluo‐8 NW at 520 nm. The same effect was observed with an rGM‐CSF solution. GM‐CSF may activate neuronal cells by stimulating the glial cells that surround and attach to them. If so, GM‐CSF and LAK‐T sup may improve the motor neurons of patients with amyotrophic lateral sclerosis. The neurogenerative effect of GM‐CSF in LAK‐T sup may also help improve brain function in aged adults including those with dementia such as Alzheimer's disease.
Selective extinction drives taxonomic and functional alpha and beta diversities in island bird assemblages
Authors: Si Xingfeng , Baselga Andrés , Leprieur Fabien , Song Xiao , Ding Ping
Published: November 2015

Taxonomic diversity considers all species being equally different from each other and thus disregards species’ different ecological functions. Exploring taxonomic and functional aspects of biodiversity simultaneously can better understand the processes of community assembly.

We analysed taxonomic and functional alpha and beta diversities of breeding bird assemblages on land‐bridge islands in the Thousand Island Lake, China. Given the high dispersal ability of most birds at this spatial scale (several kilometres), we predicted (i) selective extinction driving alpha and beta diversities after the creation of land‐bridge islands of varying area and (ii) low taxonomic and functional beta diversities that were not correlated to spatial distance.

Breeding birds were surveyed on 37 islands annually from 2007 to 2014. We decomposed beta diversity of breeding birds into spatial turnover and nestedness‐resultant components, and related taxonomic and functional diversities to island area and isolation using power regression models (for alpha diversity) and multiple regression models on distance matrices (for beta diversity). We then ran simulations to assess the strength of the correlations between taxonomic and functional diversities.

Results revealed that both taxonomic and functional alpha diversities increased with island area. The taxonomic nestedness‐resultant and turnover components increased and decreased with difference in area, respectively, but functional counterparts did not. Isolation played a minor role in explaining alpha‐ and beta‐diversity patterns. By partitioning beta diversity, we found low levels of overall taxonomic and functional beta diversities. The functional nestedness‐resultant component dominated overall functional beta diversity, whereas taxonomic turnover was the dominant component for taxonomic beta diversity. The simulation showed that functional alpha and beta diversities were significantly correlated with taxonomic diversities, and the observed values of correlations were significantly different from null expectations of random extinction.

Our assessment of island bird assemblages validated the predictions of no distance effects and low beta diversity due to pervasive dispersal events among islands and also suggested that selective extinction drives taxonomic and functional alpha and beta diversities. The contrasting turnover and nestedness‐resultant components of taxonomic and functional beta diversities demonstrate the importance of considering the multifaceted nature of biodiversity when examining community assembly.
Effects of water level and grassland management on alpha and beta diversity of birds in restored wetlands
Authors: Żmihorski Michał , Pärt Tomas , Gustafson Tomas , Berg Åke
Published: November 2015

Nearly 60% of European wetlands have been lost to drainage or to the cessation of grassland management. Large amounts of resources are put into wetland restoration with the aim to recover biodiversity. However, few studies have simultaneously evaluated effects of management, wetness and flooding dynamics on biodiversity of restored wetlands such as seasonally flooded wet grasslands.

We inventoried bird communities over 4 years at 137 sites (each 3·1 ha) within five restored wet grassland areas in Sweden to investigate whether species richness and occurrence of 12 common wet grassland species were related to (i) local conditions such as management (grazing, mowing and unmanaged areas), basic wetness and spring flooding dynamics. Further, we investigated whether (ii) the composition of the adjacent landscape (20 ha) related to local bird diversity and (iii) species turnover (i.e. beta diversity) differed between sites characterized by their basic wetness, degree of flooding and predominant management regime.

Local species richness was positively linked to degree of flooding and basic wetness of grasslands but not to type of grassland management. Species richness tended also to be negatively linked to proportion of forest at the landscape scale. Although variable, the same results were also true concerning the probability of the occurrence of a single species at the local scale.

Species turnover between sites, and thus total species richness, was distinctly higher in (i) grazed as compared to mowed grasslands except in dry non‐flooded grasslands and (ii) flooded as compared to non‐flooded sites. Similar patterns held for the subset of 12 red‐listed species. We suggest that the high beta diversity in grazed and flooded grasslands is driven by the heterogeneous vegetation structure, resulting in good conditions for foraging and nesting for several wet grassland bird species.

Synthesis and applications. The selection of wetlands for conserving wet grassland birds should prioritize temporary flooded grasslands of moderate wetness, preferably far from forest edges. Restoration and management of wet grasslands should include water level management, removal of shrubs and trees, and low‐intensity grazing, whereas mowing could be used in non‐flooded grasslands of low basic wetness.
A Better Press: A Response to John Lloyd's ‘Regulate Yourself’
Authors: Cathcart Brian
Published: November 2015

Writing recently in The Political Quarterly, the journalist John Lloyd took issue with regulatory remedies for ‘bad journalism’ in the United Kingdom that were proposed by the Leveson inquiry of 2011–12 and endorsed by Parliament in 2013 in the form of a Royal Charter. State action will fail, he asserted, because only journalists can change journalism, and he urged British journalists to undertake this transformation. This response argues that Lloyd dismisses the Leveson process too lightly and takes too little account of the many victims of press abuses, who are entitled to better protection. A decent society had to do something about this, and the Leveson Charter process was a measured and constructive response that offers the best hope of higher press standards and of protection for ordinary citizens while safeguarding freedom of expression for journalists. Lloyd's proposal for action by journalists, by contrast, is impractical, not least because it ignores powerful forces preventing journalists from taking control.
Who does nutrition prevention work in Queensland? An investigation of structural and political workforce reforms
Authors: Vidgen Helen Anna , Adam Meg , Gallegos Danielle
Published: November 2015

Aim

This study aimed (i) to determine the change in the number of government‐funded nutrition positions following structural and political reforms and (ii) to describe the remaining workforce available to do nutrition prevention work, including student placements, in Queensland.

Methods

Positions funded by the Queensland government were counted using departmental human resource data and compared with data collected 4 years earlier. Positions not funded by the government were identified using formal professional networks and governance group lists. Both groups were sent an online survey that explored their position name, funding source, employer, qualifications, years of experience, work in prevention and ability to supervise students.

Results

There was a 90% reduction in the number of nutrition prevention positions funded by the government between 2009 (137 full time equivalents (FTE)) and 2013 (14 FTE). In 2013, 313 specialist (n = 92) and generalist (n = 221) practitioners were identified as potentially working in nutrition prevention throughout Queensland. A total of 30 permanent FTEs indicated over 75% of their work focused on prevention. This included the 14 FTE funded by the Queensland government and an additional 16 FTE from other sectors. Generalists did not consider themselves part of the nutrition workforce.

Conclusions

Queensland experienced an extreme reduction in its nutrition prevention workforce as a result of political and structural reforms. This disinvestment by the Queensland government was not compensated for by other sectors, and has left marked deficits in public health nutrition capacity, including student placements.
Potential cost‐effectiveness of supervised injection facilities in Toronto and Ottawa, Canada
Authors: Enns Eva A. , Zaric Gregory S. , Strike Carol J. , Jairam Jennifer A. , Kolla Gillian , Bayoumi Ahmed M.
Published: November 2015

Background and Aims

Supervised injection facilities (legally sanctioned spaces for supervised consumption of illicitly obtained drugs) are controversial public health interventions. We determined the optimal number of facilities in two Canadian cities using health economic methods.

Design

Dynamic compartmental model of HIV and hepatitis C transmission through sexual contact and sharing of drug use equipment.

Setting

Toronto and Ottawa, Canada.

Participants

Simulated population of each city.

Interventions

Zero to five supervised injection facilities.

Measurements

Direct health‐care costs and quality‐adjusted life‐years (QALYs) over 20 years, discounted at 5% per year; incremental cost‐effectiveness ratios.

Findings

In Toronto, one facility cost $4.1 million and resulted in a gain of 385 QALYs over 20 years, for an incremental cost‐effectiveness ratio (ICER) of $10 763 per QALY [95% credible interval (95CrI): cost‐saving to $278 311]. Establishing one facility in Ottawa had an ICER of $6127 per QALY (95CrI: cost‐saving to $179 272). At a $50 000 per QALY threshold, three facilities would be cost‐effective in Toronto and two in Ottawa. The probability that establishing three, four, or five facilities in Toronto was cost‐effective was 17, 21, and 41%, respectively. Establishing one, two, or three facilities in Ottawa was cost‐effective with 13, 35, and 41% probability, respectively. Establishing no facility was unlikely to be the most cost‐effective option (14% in Toronto and 10% in Ottawa). In both cities, results were robust if the reduction in needle‐sharing among clients of the facilities was at least 50% and fixed operating costs were less than $2.0 million.

Conclusions

Using a $50 000 per quality‐adjusted life‐years threshold for cost‐effectiveness, it is likely to be cost‐effective to establish at least three legally sanctioned spaces for supervised injection of illicitly obtained drugs in Toronto, Canada and two in Ottawa, Canada.
Salvia divinorum: An overview of the usage, misuse, and addiction processes
Authors: Mahendran Rathi , Lim Haikel A. , Tan Joyce Y.S. , Chua Shi Min , Winslow Munidasa
Published: November 2015

Salvia divinorum, a sage plant with leaves that can produce a psychoactive high, has been used for hundreds of years for its psycho‐mimetic effects in religious rituals in South America. Salvia has now become popular mainly with adolescents and young adults for the short‐lived relatively pleasant experiences many consider a “legal high” and its ready availability through Internet purchases. The main (psycho)active compound in salvia is Salvinorin A, a potent κ‐opioid agonist and although the short and long‐term effects have not been examined in sufficient detail, it is widely believed to have low addictive potential and low toxicity. Recent findings, however, seem to suggest that Salvinorin A can precipitate psychiatric symptoms and negatively affect cognition. Its ready availability and increasingly widespread use requires clinicians to have knowledge and awareness of its effects.
Psychometric properties of Malay neuropsychiatry unit cognitive assessment tool among Alzheimer's disease patients in comparison to Malay Montreal Cognitive Assessment
Authors: Thong Kai Shin , Chee Kok Yoon , Ng Chong Guan , Walterfang Mark , Velakoulis Dennis
Published: November 2015

This study aims to establish psychometric properties of the Malay Neuropsychiatry Unit Cognitive Assessment Tool (Malay NuCOG) in Alzheimer's disease. NuCOG was translated to Malay language and compared with Montreal Cognitive Assessment Tool on 80 individuals. The Malay NuCOG showed good internal consistency and reliability (Cronbach's alpha = 0.895). It demonstrated 100% sensitivity and 87.5% specificity at the cutoff score of 78.50/100. The Malay NuCOG is a valid and reliable cognitive instrument that is sensitive and specific for the detection of dementia and has clinical advantages in its ability to examine individual cognitive domains.
Review article: potential mechanisms of action of rifaximin in the management of hepatic encephalopathy and other complications of cirrhosis
Authors: Bajaj J. S.
Published: November 2015

Background

Progressive gut milieu (microbiota) changes occur in patients with cirrhosis and are associated with complications [e.g. hepatic encephalopathy (HE)].

Aim

To examine the role of rifaximin in the management of HE and other complications of cirrhosis, including potential mechanisms of action and the need for future studies.

Methods

A literature search was conducted using the keywords ‘rifaximin’, ‘hepatic encephalopathy’, ‘ascites’, ‘variceal bleeding’, ‘peritonitis’, ‘portal hypertension’, ‘portopulmonary hypertension’ and ‘hepatorenal syndrome’.

Results

The nonsystemic agent rifaximin reduces the risk of HE recurrence and HE‐related hospitalisations in cirrhosis. In patients with cirrhosis, rifaximin modulates the bacterial composition of the gut microbiota without a consistent effect on overall faecal microbiota composition. However, rifaximin can impact the function or activities of the gut microbiota. For example, rifaximin significantly increased serum levels of long‐chain fatty acids and carbohydrate metabolism intermediates in patients with minimal HE. Rifaximin also favourably affects serum proinflammatory cytokine and faecal secondary bile acid levels.

Conclusions

The gut microenvironment and associated microbiota play an important role in the pathogenesis of HE and other cirrhosis‐related complications. Rifaximin's clinical activity may be attributed to effects on metabolic function of the gut microbiota, rather than a change in the relative bacterial abundance.
Review article: potential mechanisms of action of rifaximin in the management of irritable bowel syndrome with diarrhoea
Authors: Pimentel M.
Published: November 2015

Background

The role of gut microbiota in the pathophysiology of irritable bowel syndrome (IBS) is supported by various lines of evidence, including differences in mucosal and faecal microbiota between patients with IBS and healthy individuals, development of post‐infectious IBS, and the efficacy of some probiotics and nonsystemic antibiotics (e.g. rifaximin).

Aim

To review the literature regarding the role of rifaximin in IBS and its potential mecha‐nism(s) of action.

Methods

A literature search was conducted using the terms ‘rifaximin’, ‘irritable bowel syndrome’ and ‘mechanism of action’.

Results

Rifaximin was approved in 2015 for the treatment of IBS with diarrhoea. In contrast to other currently available IBS therapies that require daily administration to maintain efficacy, 2‐week rifaximin treatment achieved symptom improvement that persisted ≥12 weeks post‐treatment. The mechanisms of action of rifaximin, therefore, may extend beyond direct bactericidal effects. Data suggest that rifaximin may decrease host proinflammatory responses to bacterial products in patients with IBS. In some cases, small intestinal bacterial overgrowth (SIBO) may play a role in the clinical symptoms of IBS. Because of the high level of solubility of rifaximin in the small intestine, rifaximin may reset microbial diversity in this environment. Consistent with this hypothesis, rifaximin has antibiotic efficacy against isolates derived from patients with SIBO.

Conclusion

Resetting microbial diversity via rifaximin use may lead to a decrease in bacterial fermentation and a reduction in the clinical symptoms of IBS.