bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and design optimisation of compact UWB slot antenna
Authors: Bekasiewicz A. , Koziel S.
Published: February 2016

A structure and computationally efficient design optimisation procedure of a novel miniaturised UWB slot antenna has been proposed. Upon geometry parameter adjustment, the structure exhibits a very small footprint of just 161 mm2. This has been achieved by introducing sufficient number of degrees of freedom, including the parameterised multi‐section slot and a multi‐section load of the feed line as well as efficient numerical optimisation of all relevant geometry dimensions of the structure. The design process has been formulated as explicit size reduction problem. The electrical performance parameters (here, a maximum in‐band reflection) are controlled by suitably defined constraints. The final design has been verified through full‐wave electromagnetic simulation as well as physical measurements of the fabricated antenna prototype.
Optical phase‐locking of two longitudinal modes of a dual‐mode laser for millimetre‐wave signal generation
Authors: Hyodo M. , Sato K. , Kawakami A. , Saito S. , Watanabe M. , Adachi M.
Published: February 2016

Phase‐locking of two longitudinal oscillating modes of a dual‐mode microchip laser that has 101 GHz longitudinal‐mode spacing has been successfully demonstrated by using electronic negative‐feedback control. Since the two longitudinal modes were oscillating simultaneously in the same laser cavity, the common‐mode fluctuation cancels, resulted in the small required control bandwidth of ∼4 kHz. This narrow‐bandwidth phase‐locking technique is useful for generating high‐spectral‐purity millimetre‐wave signals with a considerably simpler setup.
Compact sext‐band bandpass filter based on single multimode resonator with high band‐to‐band isolations
Authors: Ai Jing , Zhang Yonghong , Xu Kai Da , Guo Yingjiang , Joines William Thomas , Liu Qing Huo
Published: February 2016

On the basis of a single multimode resonator (MMR), a miniaturised microstrip sext‐band bandpass filter (BPF) with high band‐to‐band isolations has been presented. The proposed MMR is an stepped impedance resonator (SIR) with one short‐circuited stub loaded in the middle and two identical open‐circuited stubs located at two sides. Transmission poles (TPs) and transmission zeros (TZs) can be excited when the electrical lengths of two open stubs increase. The TZs introduced by open stubs separate the TPs into multiple groups; therefore, the design of a sext‐band BPF becomes available. Moreover, two input/output tapped branches and radical stub‐loaded short‐circuited lines are treated as perturbation structures in order to increase design freedoms for improving filter performance. Good agreement between simulated and measured results validates the design method.
Optical single sideband signal generation relying on a single‐drive Mach–Zehnder modulator for radio over fibre communications
Authors: Antony Thomas Varghese , El‐Hajjar Mohammed , Hanzo Lajos
Published: February 2016

Optical single sideband (OSSB) signals are conventionally generated using a dual‐drive Mach–Zehnder modulator (MZM) or by using a single‐drive MZM in conjunction with a fibre Bragg grating filter. In this study, the authors propose and mathematically characterise a novel radio over fibre downlink in which an OSSB signal is generated using a single‐drive, rather than dual‐drive, MZM without any additional filter. Additionally, their proposed scheme can achieve optical upconversion of the electronic signal. Furthermore, in addition to cost advantages, the proposed scheme's bit error ratio (BER) performance is better than the classical OSSB signal generation scheme.
Joint user scheduling and channel allocation for cellular networks with full duplex base stations
Authors: Yu Guanding , Wen Dingzhu , Qu Fengzhong
Published: February 2016

Full‐duplex communication (FDC) can potentially double the network capacity by allowing a device to transmit and receive simultaneously on the same frequency band. In this study, a novel resource allocation and user scheduling algorithm is proposed to maximise the network throughput for a cellular network with full‐duplex (FD) base stations (BSs). The authors consider that FDC is utilised at the BS with imperfect self‐interference (SI) cancellation while user devices only work in the traditional half‐duplex (HD) way. In addition, to potentially cancel co‐channel interference caused by other users, the opportunistic interference cancellation (OIC) technique is applied at user side. Since FDC does not always perform better than HD due to residual SI (RSI), a joint mode selection, user scheduling, and channel allocation problem is formulated to maximise the system throughput. The optimisation problem is non‐convex and NP‐hard, thereby a suboptimal heuristic algorithm with low computational complexity is proposed. Numerical results demonstrate that user diversity gain, FD gain, and OIC gain can be achieved by the proposed algorithm, respectively. The performance of FDC depends on the intensity of RSI and the distribution of user devices.
Semi‐global stabilisation with guaranteed regional performance for delta operator systems subject to actuator saturation
Authors: Yang Hongjiu , Zhang Luyang , Xia Yuanqing , Li Li
Published: February 2016

In this study, the domain of attraction is further enlarged for delta operator systems subject to actuator saturation by considering semi‐global stabilisation with guaranteed regional performance. An original feedback law is designed to guarantee certain close‐loop performance in a fixed region which is a compact subset of the null controllable region. Some fixed regions that cover compact subsets of the null controllable region are obtained by a finite sequence of state feedback laws. The union of all obtained fixed regions is the final domain of attraction for the delta operator systems with actuator saturation. A numerical example is provided to illustrate the effectiveness of the proposed techniques.
Dimensionality reduction of Fisher vectors for human action recognition
Authors: Oruganti Venkata Ramana Murthy , Goecke Roland
Published: February 2016

Automatic analysis of human behaviour in large collections of videos is rapidly gaining interest, even more so with the advent of file sharing sites such as YouTube. From one perspective, it can be observed that the size of feature vectors used for human action recognition from videos has been increasing enormously in the last five years, in the order of ∼100–500K. One possible reason might be the growing number of action classes/videos and hence the requirement of discriminating features (that usually end up to be higher‐dimensional for larger databases). In this study, the authors review and investigate feature projection as a means to reduce the dimensions of the high‐dimensional feature vectors and show their effectiveness in terms of performance. They hypothesise that dimensionality reduction techniques often unearth latent structures in the feature space and are effective in applications such as the fusion of high‐dimensional features of different types; and action recognition in untrimmed videos. They conduct all the authors’ experiments using a Bag‐of‐Words framework for consistency and results are presented on large class benchmark databases such as the HMDB51 and UCF101 datasets.
Feature detection and matching on atmospheric nuclear detonation video
Authors: Schmitt Daniel T. , Peterson Gilbert L.
Published: February 2016

Automated feature matching of nuclear detonations (NUDETs) enables three‐dimensional point cloud reconstruction, and establishment a volume‐based model to reduce uncertainty in estimating the yield of NUDETs solely from video. Establishing a volume‐based model requires feature correspondences between wide viewpoints of 58°–110° that are larger than scale‐invariant feature transform‐based techniques can reliably match. The presented technique detects relative bright features in the NUDET known as ‘hotspots,’ and matches them across wide viewpoints using a spherical based object model. Results show that hotspots can be detected with a 71.95% hit rate and 86.03% precision. Hotspots are matched to films from different viewpoints with 76.6% correctness and a standard deviation of 16.4%. Hotspot descriptors are also matched in time sequence with 99.6% correctness and a standard deviation of 1.07%. The results demonstrate that a spherical model can serve as a viable descriptor model for matching across wide viewpoints when the object is known to be spherical. It also demonstrates an automated feature detection and matching combination that enables features to be matched from unsynchronised video across wide viewpoints of 58°–110° on spherical objects where state‐of‐the‐art techniques are insufficient.
Multiple deep features learning for object retrieval in surveillance videos
Authors: Guo Haiyun , Wang Jinqiao , Lu Hanqing
Published: February 2016

Efficient indexing and retrieving objects of interest from large‐scale surveillance videos are a significant and challenging topic. In this study, the authors present an effective multiple deep features learning approach for object retrieval in surveillance videos. Based on the discriminative convolutional neural network (CNN), they can learn multiple deep features to comprehensively describe the visual object. To be specific, they utilise the CNN model pre‐trained on ImageNet ILSVRC12 and fine‐tuned on our dataset to abstract structure information. In addition, they train another CNN model supervised by 11 colour names to deliver the colour information. To improve the retrieval performance, the deep features are encoded into short binary codes by locality‐sensitive hash and fused to fast retrieve the object of interest. Retrieval experiments are performed on a dataset of 100k objects extracted from multi‐camera surveillance videos. Comparison results with other common visual features show the effectiveness of the proposed approach.
A one-step optimal energy decay formula for indirectly nonlinearly damped hyperbolic systems coupled by velocities
Authors: Alabau-Boussouira Fatiha , Wang Zhiqiang , Yu Lixin
Published: February 2016

In this paper, we consider the energy decay of a damped hyperbolic system of wave-wave type which is coupled through the velocities. We are interested in the asymptotic properties of the solutions of this system in the case of indirect nonlinear damping, i.e. when only one equation is directly damped by a nonlinear damping. We prove that the total energy of the whole system decays as fast as the damped single equation. Moreover, we give a one-step general explicit decay formula for arbitrary nonlinearity. Our results shows that the damping properties are fully transferred from the damped equation to the undamped one by the coupling in velocities, different from the case of couplings through displacements as shown in [F. Alabau, C. R. Acad. Sci. Paris Sér. I Math. 328 (1999) 1015–1020; F. Alabau, P. Cannarsa and V. Komornik, J. Evol. Equ. 2 (2002) 127–150; F. Alabau, SIAM J. Control Optim. 41 (2002) 511–541; F. Alabau-Boussouira and M. Léautaud, ESAIM: COCV 18 (2012) 548–582] for the linear damping case, and in [F. Alabau-Boussouira, NoDEA 14 (2007) 643–669] for the nonlinear damping case. The proofs of our results are based on multiplier techniques, weighted nonlinear integral inequalities and the optimal-weight convexity method of [F. Alabau-Boussouira, Appl. Math. Optim. 51 (2005) 61–105; F. Alabau-Boussouira, J. Differ. Equ. 248 (2010) 1473–1517].
Stiffness optimization of geometrically nonlinear structures and the level set based solution
Authors: Xia Qi , Shi Tielin
Published: February 2016

Load-normalized strain energy increments between consecutive load steps are aggregated through the Kreisselmeier-Steinhauser (KS) function, and the KS function is proposed as a stiffness criterion of geometrically nonlinear structures. A topology optimization problem is defined to minimize the KS function together with the perimeter of structure and a volume constraint. The finite element analysis is done by remeshing, and artificial weak material is not used. The topology optimization problem is solved by using the level set method. Several numerical examples in two dimensions are provided. Other criteria of stiffness, i.e., the end compliance and the complementary work, are compared.
Influence of the liquid helium meniscus on neutron reflectometry data
Authors: Kinane C. J. , Kirichek O. , Charlton T. R. , McClintock P. V. E.
Published: February 2016

Neutron reflectometry offers a unique opportunity for the direct observation of nanostratification in 3He-4He mixtures in the ultra-low temperature limit. Unfortunately the results of recent experiments could not be well-modelled on account of a seemingly anomalous variation of reflectivity with momentum transfer. We now hypothesize that this effect is attributable to an optical distortion caused by the liquid's meniscus near the container wall. The validity of this idea is tested and confirmed through a subsidiary experiment on a D2O sample, showing that the meniscus can significantly distort results if the beam size in the horizontal plane is comparable with, or bigger than, the diameter of the container. The meniscus problem can be eliminated if the beam size is substantially smaller than the diameter of the container, such that reflection takes place only from the flat region of the liquid surface thus excluding the meniscus tails. Practical measures for minimizing the meniscus distortion effect are discussed.
Heat capacity of xenon adsorbed on nanobundle grooves
Authors: Chishko K. A. , Sokolova E. S.
Published: February 2016

A model of a one-dimensional nonideal gas in an external transverse force field is used to interpret the experimentally observed thermodynamic properties of xenon deposited in grooves on the surface of carbon nanobundles. A nonideal gas model with pairwise interactions is not entirely adequate for describing dense adsorbates (at low temperatures), but makes it easy to account for the exchange of particles between the 1D adsorbate and the 3D atmosphere, which is an important factor at intermediate (on the order of 35 K for xenon) and, especially, high (∼100 K) temperatures. In this paper, we examine a 1D real gas taking only the one-dimensional Lennard-Jones interaction into account, but under exact equilibrium with respect to the number of particles between the 1D adsorbate and the 3D atmosphere of the measurement cell. The low-temperature branch of the specific heat is fitted independently by an elastic chain model so as to obtain the best agreement between theory and experiment over the widest possible region, beginning at zero temperature. The gas approximation sets in after temperatures for which the phonon specific heat of the chain essentially transforms to a one-dimensional equipartition law. Here the basic parameters of both models can be chosen so that the heat capacity C(T) of the chain transforms essentially continuously into the corresponding curve for the gas approximation. Thus, it can be expected that an adequate interpretation of the real temperature dependences of the specific heat of low-dimensionality atomic adsorbates can be obtained through a reasonable combination of the phonon and gas approximations. The main parameters of the gas approximation (such as the desorption energy) obtained by fitting the theory to experiments on the specific heat of xenon correlate well with published data.
Interference effects in silicon-germanium heterostructures with quantum wells of different widths
Authors: Berkutov I. B. , Andrievskii V. V. , Komnik Yu. F. , Kolesnichenko Yu. A. , Berkutova A. I. , Leadley D. R. , Mironov O. A.
Published: February 2016

Weak localization effects and the interactions of charge carriers are studied in two Si0.7Ge0.3/Si0.2Ge0.8/Si0.7Ge0.3 p-type heterostructures, where one or two quantum levels are filled, respectively. A weak localization effect for two-dimensional charge carriers is found to occur in weak magnetic fields when the spin-orbital and inelastic scattering times are close, which is indicative of splitting of the spin states under the influence of a perturbing potential related to the formation of a two-dimensional potential well (Rashba mechanism). In higher magnetic fields when one quantum level is occupied, interaction effects appear that are caused by Coulomb interactions with a scatterer. When the two quantum levels are occupied, the dominant mechanism is scattering on Friedel oscillations of the charge carrier density induced by an impurity electric field. In all regions, the quantum corrections are in good agreement with modern theoretical predictions.
Contributed Review: Recent developments in acoustic energy harvesting for autonomous wireless sensor nodes applications
Authors: Khan Farid Ullah , Khattak Muhammad Umair
Published: February 2016

Rapid developments in micro electronics, micro fabrication, ultra-large scale of integration, ultra-low power sensors, and wireless technology have greatly reduced the power consumption requirements of wireless sensor nodes (WSNs) and make it possible to operate these devices with energy harvesters. Likewise, other energy harvesters, acoustic energy harvesters (AEHs), have been developed and are gaining swift interest in last few years. This paper presents a review of AEHs reported in the literature for the applications of WSNs. Based on transduction mechanism, there are two types of AEHs: piezoelectric acoustic energy harvesters (PEAEHs) and electromagnetic acoustic energy harvesters (EMAEHs). The reported AEHs are mostly characterized under the sound pressure level (SPL) that ranges from 45 to 161 dB. The range for resonant frequency of the produced AEHs is from 146 Hz to 24 kHz and these produced 0.68 × 10−6 μW to 30 mW power. The maximum power (30 mW) is produced by a PEAEH, when the harvester is subjected to a SPL of 161 dB and 2.64 kHz frequency. However, for EMAEHs, the maximum power reported is about 1.96 mW (at 125 dB and 143 Hz). Under the comparable SPLs, the power production by the reported EMAEHs is relatively better than that of PEAEHs, moreover, due to lower resonant frequency, the EMAEHs are more feasible for the low frequency band acoustical environment.
A new approach to studying the luminescence spectra of free icosahedral and crystalline argon nanoclusters
Authors: Doronin Yu. S. , Vakula V. L. , Kamarchuk G. V. , Tkachenko A. A. , Samovarov V. N.
Published: February 2016

We propose a new approach to analyzing the cathodoluminescence spectra of free argon nanoclusters, forming in a supersonic jet flowing into vacuum. Based on this approach, we conduct an analysis of the intensities of the luminescence bands of neutral and charged excimer complexes (Ar2)* and (Ar+4)*, measured for clusters with an average size ranging from 500 to 8900 atoms per cluster, and a diameter of 32–87 Å. It is shown that the concentration of the substance condensed into clusters, which determines the integrated intensity of the bands, is proportional to the logarithm of the average size of the clusters in the jet. An analysis of the normalized intensities of the (Ar2)* and (Ar+4)* bands for crystalline clusters with an fcc structure allowed us to establish that the luminescence of neutral (Ar2)* molecules comes from within the volume of the cluster, while the charged complexes (Ar+4)* emit from the subsurface layer. We highlighted an area of cluster dimensions at which the jet is dominated by quasi-crystalline clusters with an icosahedral structure, and it is shown that the transition from icosahedral clusters to fcc structures occurs when the average size of the cluster in the jet is N¯ = (1000–1800) atoms/cluster.
Photothermal effects of plasmonic metal nanoparticles in a fluid
Authors: Norton Stephen J. , Vo-Dinh Tuan
Published: February 2016

There is a strong interest in the use of plasmonic metal nanoparticles in medical applications involving photothermal therapy. In this study, the problem of calculating the temperature elevation of a fluid arising from the absorption of light by a suspension of plasmonic nanoparticles is examined. The dependence of this temperature increase on the absorption cross section of nanoparticles of different shapes, in particular, nanospheres, nanospheroids, and nanostars, is studied. The nanoparticles behave as point sources of heat production and the time-dependent heat transfer equation is solved assuming that the nanoparticles are confined to a limited region. From this solution, the steady-state temperature of the fluid medium can be calculated and the time constant to achieve this temperature determined.
Gate control of ferromagnetic insulating phase in lightly-doped La0.875Sr0.125MnO3−δ film
Authors: Kuang H. , Wang J. , Hu F. X. , Zhao Y. Y. , Liu Y. , Wu R. R. , Sun J. R. , Shen B. G.
Published: February 2016

The electric field effect on the lightly doped La0.875Sr0.125MnO3−δ (LSMO) thin film in electric double-layer transistors was investigated by measuring transport properties of the film under various gate voltages. It was found that the positive gate bias leads to an increase of the charge-orbital ordering (COO) transition temperature and a decrease of the Curie temperature TC, indicating the suppression of ferromagnetic metal (FMM) phases and preference of COO/ferromagnetic insulator (FMI) with the hole depletion by gate bias. Such different electric field effects can be ascribed to the weakening of the ferromagnetic interaction and enhancement of Jahn-Teller (JT) distortion caused by the transformation of JT inactive Mn4+-ions to JT active Mn3+-ions. Moreover, a step-like increase in the high temperature region of the ρ-T curve, which is related to the transition of cooperative JT distortion, was found to develop with increasing the positive bias, indicating that the cooperative JT distorted phase is stabilized by the depletion of holes in LSMO film. These results demonstrate that the modulation of holes via electric field strongly affects the balance between energy gains of different interactions and thus produce different effects on the competing FMI, FMM, and cooperative JT distorted phases in LSMO film.
Back-gated Nb-doped MoS2 junctionless field-effect-transistors
Authors: Mirabelli Gioele , Schmidt Michael , Sheehan Brendan , Cherkaoui Karim , Monaghan Scott , Povey Ian , McCarthy Melissa , Bell Alan P. , Nagle Roger , Crupi Felice , Hurley Paul K. , Duffy Ray
Published: February 2016

Electrical measurements were carried out to measure the performance and evaluate the characteristics of MoS2 flakes doped with Niobium (Nb). The flakes were obtained by mechanical exfoliation and transferred onto 85 nm thick SiO2 oxide and a highly doped Si handle wafer. Ti/Au (5/45 nm) deposited on top of the flake allowed the realization of a back-gate structure, which was analyzed structurally through Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). To best of our knowledge this is the first cross-sectional TEM study of exfoliated Nb-doped MoS2 flakes. In fact to date TEM of transition-metal-dichalcogenide flakes is extremely rare in the literature, considering the recent body of work. The devices were then electrically characterized by temperature dependent Ids versus Vds and Ids versus Vbg curves. The temperature dependency of the device shows a semiconductor behavior and, the doping effect by Nb atoms introduces acceptors in the structure, with a p-type concentration 4.3 × 1019 cm−3 measured by Hall effect. The p-type doping is confirmed by all the electrical measurements, making the structure a junctionless transistor. In addition, other parameters regarding the contact resistance between the top metal and MoS2 are extracted thanks to a simple Transfer Length Method (TLM) structure, showing a promising contact resistivity of 1.05 × 10−7 Ω/cm2 and a sheet resistance of 2.36 × 102 Ω/sq.
A model of conference interpretation
Authors: Al-Kufaishi Adil
Published: February 2016

The objective of this research is to develop a model of consecutive interpretation that can cope with a number of linguistic, pragmatic, stylistic, thematic, discourse and communicative problems a conference interpreter encounters while interpreting from English into Arabic or vice versa. A linguistic corpus of one hundred page English speeches delivered at the United Nation General Assembly sessions and interpreted into Arabic is analysed. The proposed model caters for both the SL and TL communicative contexts and views the conference interpreter as a mediator who decodes the original message and encodes it appropriately. The model is tested against the collected sample of linguistic data. It has proved to be capable of identifying inconsistencies and inaccuracies in five major areas: textual, stylistic, lexical, collocation and structural; the percentage of each is statistically calculated.

The stylistic aspects constitute 39.3% of the inconsistencies; these cover the deviant forms that are not acceptable in Arabic: the stylistic variants, the modes of request, and the language forms that need to be reformulated in order to be consistent with the Arabic rhetorical patterns. The inappropriate rendering of lexical items makes up 26.1% of the inconsistencies; this comprises the inappropriately rendered collocation patterns, clichés and idiomatic expressions. The structural aspects constitute 18 % of the incorrectly interpreted language forms; these are the inappropriately rendered passive and modification constructions. The textual aspects constitute 10.9% of the inconsistencies; these are the parallel constructions that are not properly handled in Arabic. Translation inaccuracies, items missed or incorrectly interpreted, constitute 5.1% of the inconsistencies.
6. Peer interaction in F2F and CMC contexts
Authors: Loewen Shawn , Wolff Dominik
Published: February 2016

The current chapter adopts an interactionist perspective to investigate various characteristics of L2 learners’ interaction in three different communication modalities: face-to-face, oral synchronous computer-mediated communication, and written synchronous computer-mediated communication. Forty-eight intermediate proficiency L2 learners of English engaged in three different interactive tasks in one of the three communicative contexts. Characteristics of interaction that are considered to be beneficial for L2 development, namely negotiation for meaning, recasts, and language-related episodes, were identified in the discourse and compared across the three modalities. In addition, task effects on interaction were compared. Results indicated that interaction during the face-to-face and oral synchronous computer-mediated communication was similar, but differed from written synchronous computer-mediated communication in terms of a greater number of confirmation checks and language-related episodes. However, no differences in interactional features were found across the three different tasks. These results suggest that different communication modalities may afford different opportunities for learners.
7. Thai EFL learners’ interaction during collaborative writing tasks and its relationship to text quality
Authors: McDonough Kim , Crawford William J. , De Vleeschauwer Jindarat
Published: February 2016

Second language (L2) writing research has shown that L2 learners routinely scaffold each other when working together to co-construct written texts. The analysis of peer interaction has focused largely on the occurrence of language-related episodes (LREs), with fewer studies documenting how learners discuss other elements of written texts, such as their content or organization (Elola & Oskoz 2010; Storch 2005; Storch & Wigglesworth 2007; Wigglesworth & Storch 2009), or establishing a link between student interaction and text quality. This chapter describes the interaction that occurred when Thai EFL students worked in pairs to write summary and problem/solution paragraphs and explores whether their discussions were related to text quality in the form of analytic ratings. The results indicated that problem/solution collaborative writing tasks showed a positive relationship between student talk and text quality and elicited significantly more discussion of content, organization, and language than summary tasks. Implications are discussed in terms of pedagogical considerations for the use of collaborative writing tasks in EFL contexts.
10. A focus on mode
Authors: Rouhshad Amir , Storch Neomy
Published: February 2016

Research on pair and small group work has shown that collaborative writing tasks generally encourage learners to focus on language. However, some studies (e.g., Storch 2002) have also shown that patterns of interaction during collaborative writing tasks affect the quantity and quality of learners’ attention to language and ultimately language learning. The study reported in this chapter compared patterns of interaction of the same pairs of intermediate ESL learners completing a collaborative writing task in a face-to-face and a computer-mediated mode (Google Docs). The study found that mode had an impact on patterns of interaction and attention to language. Learners were more likely to collaborate in the face-to-face mode and to cooperate in the computer-mediated mode. It was only when learners collaborated, that they engaged extensively in deliberations about language.
Overdispersion in the Estimation of Salmon Escapements by Mark–Recapture Surveys and Its Related Factors
Authors: Miyakoshi Yasuyuki , Kitada Shuichi
Published: February 2016

The Petersen method, a well‐known mark–recapture method, is frequently used in the estimation of escapement of Pacific salmon Oncorhynchus spp. Robust estimates and associated variances can be obtained when the underlying assumptions of this method are met. However, in field surveys, it is often difficult to meet these assumptions because wild animals are often not randomly distributed. When the sampling variance of the estimator exceeds its binomial variance (resulting in overdispersion), the Petersen model underestimates variance. We assessed the occurrence of overdispersion in the mark–recapture data collected to estimate the escapements of Masu Salmon Oncorhynchus masou in a river in northern Japan in 1998 and 1999. The dispersion parameters estimated from 2‐year data were 2.89 and 2.51 for males and 1.45 and 1.52 for females, indicating that overdispersion occurred in all cases. The magnitude of overdispersion for males exceeded that for females, probably related to differences in the postspawning behaviors of the sexes, as represented by the changes of the sex ratio of Masu Salmon recovered on the spawning grounds. In this paper, we propose a simple procedure to detect the occurrence of overdispersion in multiple‐recovery mark–recapture data.

Received February 8, 2015; accepted November 3, 2015
Juvenile Lake Sturgeon Go To School: Life‐Skills Training for Hatchery Fish
Authors: Sloychuk Janelle R. , Chivers Douglas P. , Ferrari Maud C. O.
Published: February 2016

Hatchery supplementation of declining fish populations is commonly employed to try to increase year‐class strength. However, the success of such programs is often hampered from low postrelease survival as a result of the failure of hatchery fish to appropriately recognize predation threats. Not surprisingly, there has been considerable effort to train prey to recognize predators prior to release. The objective of our current work was to characterize the antipredator response of hatchery‐reared, predator‐naive young‐of‐the‐year Lake Sturgeon Acipenser fulvescens (an endangered species) to alarm cues from injured conspecifics and test whether these alarm cues could be used to train sturgeon to recognize unknown predators. We found that skin‐derived alarm cues elicited an antipredator response without learning and that learning required cues coming from whole‐body grinds, presumably because they represent a much more reliable indicator of risk. When the experiment was repeated with older sturgeon from Wolf River (Wisconsin), training with cues from whole‐body grinds did not enhance the response. Subjecting the fish to several training sessions (six over 3 d) led to some alteration in behavior. Our results provide insights into how ontogenetic changes (size, scute growth) could explain the different learning outcomes from the larger fish as related to hatcheries and conservation programs.

Received June 24, 2015; accepted November 17, 2015
Distribution of Infectious Pancreatic Necrosis Virus (IPNV) Based on Surveillance Programs in Freshwater Trout Farms of Mexico
Authors: Ortega César , Valladares Benjamín , Arguedas Donald , Vega Fernando , Montes de Oca Roberto , Murray Alexander G
Published: February 2016

Diagnostic testing was performed between 2000 and 2012 to determine the distribution of infectious pancreatic necrosis virus (IPNV) in the main states of the Mexican Republic with freshwater Rainbow Trout Oncorhynchus mykiss (Walbaum) farms. This virus was positively identified from Rainbow Trout farms in seven of the eight states assessed. Due to nonnormal data distribution, a logistic regression model was applied for statistical analysis, the results of which indicated that virus prevalence was variable between states, with moderate but significant differences. Regarding the time periods evaluated, IPNV prevalence was higher during the first years of the study. The susceptible, infected, removed model was used to examine this phenomenon, which indicated that the decreased prevalence during the latter years of the study could be associated with a real elimination of the infection. The information of the cases analyzed also suggests a relationship with the irregularity in the submission of samples to the laboratory and emphasizes other factors that have contributed to the transmission of IPNV throughout the country.

Received November 10, 2014; accepted December 5, 2015.
Biocompatibility and mechanical behaviour of three-dimensional scaffolds for biomedical devices: process–structure–property paradigm
Authors: Kumar A. , Nune K. C. , Murr L. E. , Misra R. D. K.
Published: February 2016

We elucidate here process–structure–property relationships in implantable biomaterials processed by rapid prototyping approaches that are based on the principle of additive manufacturing. The conventional methods of fabrication of biomedical devices including freeze casting and sintering are limited because of difficulties in adaptation at the host site and mismatch in micro/macrostructure, mechanical and physical properties with the host tissue. Moreover, additive manufacturing has the advantage of fabricating patient-specific designs, which can be obtained from the computed tomography scan of the defect site. The discussion here comprises two parts – the first part briefly describes the evolution and underlying reasons that have led to 3D printing of scaffolds for tissue regeneration. The second part focuses on biocompatibility and mechanical properties of 3D scaffolds, fabricated by different approaches. The article concludes with a discussion on functionally graded scaffolds and vascularisation of 3D porous scaffolds that are envisaged to meet the requirements of the biomedical industry. In general, the mechanical properties of 3D printed scaffolds are governed by pore architecture, pore volume and percentage porosity. To ensure long-term endurance and the ability to withstand abrupt impact, it is important that the fabricated materials have a good combination of strength and energy absorption capability. While scaffolds with high interconnected porosity are preferred for tissue regeneration, such structures lack adequate mechanical strength and energy absorption capability. These mutually opposing requirements of high porosity and mechanical strength in conjunction with high energy absorption have hindered the application of 3D scaffolds as biomedical devices. In this regard, functionally graded 3D structures with high strength and energy absorption are potentially attractive for biomedical devices.
Learning affordances of language and communication national curricula
Authors: Scott David
Published: February 2016

This article focuses on the learning affordances of different language and communication curricula in the world. For reasons of space, only two national education systems (Finland and Singapore) and their language and communication curricula are referred to. The accounts of national education systems consist of the identification of mechanisms operating in real‐life contexts. A curriculum is a set of ideas, which is then subsequently transformed into an arrangement of teaching and learning practices. These transformations constitute marked changes in the form, nature or appearance of the curriculum between different time points; and they can be expressed as a series of stages, such as exploration and development, re‐contextualisation, implementation, re‐implementation and institutionalisation. What this also implies is that school curricula round the world are different in content, form, relations between their different parts, intended effects, prescriptive capacity and internal coherence. If we take one issue, that of language and communication standards, we can see that there are different models and we can conjecture that they will have different effects.
Alpha-CENTAURI: assessing novel centromeric repeat sequence variation with long read sequencing
Authors: Sevim Volkan , Bashir Ali , Chin Chen-Shan , Miga Karen H.
Published: February 2016

Motivation: Long arrays of near-identical tandem repeats are a common feature of centromeric and subtelomeric regions in complex genomes. These sequences present a source of repeat structure diversity that is commonly ignored by standard genomic tools. Unlike reads shorter than the underlying repeat structure that rely on indirect inference methods, e.g. assembly, long reads allow direct inference of satellite higher order repeat structure. To automate characterization of local centromeric tandem repeat sequence variation we have designed Alpha-CENTAURI (ALPHA satellite CENTromeric AUtomated Repeat Identification), that takes advantage of Pacific Bioscience long-reads from whole-genome sequencing datasets. By operating on reads prior to assembly, our approach provides a more comprehensive set of repeat-structure variants and is not impacted by rearrangements or sequence underrepresentation due to misassembly.

Results: We demonstrate the utility of Alpha-CENTAURI in characterizing repeat structure for alpha satellite containing reads in the hydatidiform mole (CHM1, haploid-like) genome. The pipeline is designed to report local repeat organization summaries for each read, thereby monitoring rearrangements in repeat units, shifts in repeat orientation and sites of array transition into non-satellite DNA, typically defined by transposable element insertion. We validate the method by showing consistency with existing centromere high order repeat references. Alpha-CENTAURI can, in principle, run on any sequence data, offering a method to generate a sequence repeat resolution that could be readily performed using consensus sequences available for other satellite families in genomes without high-quality reference assemblies.

Availability and implementation: Documentation and source code for Alpha-CENTAURI are freely available at http://github.com/volkansevim/alpha-CENTAURI.

Contact:  ali.bashir@mssm.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Applying organized scepticism to ocean acidification research
Authors: Browman Howard I.
Published: February 2016

“Ocean acidification” (OA), a change in seawater chemistry driven by increased uptake of atmospheric CO2 by the oceans, has probably been the most-studied single topic in marine science in recent times. The majority of the literature on OA report negative effects of CO2 on organisms and conclude that OA will be detrimental to marine ecosystems. As is true across all of science, studies that report no effect of OA are typically more difficult to publish. Further, the mechanisms underlying the biological and ecological effects of OA have received little attention in most organismal groups, and some of the key mechanisms (e.g. calcification) are still incompletely understood. For these reasons, the ICES Journal of Marine Science solicited contributions to this special issue. In this introduction, I present a brief overview of the history of research on OA, call for a heightened level of organized (academic) scepticism to be applied to the body of work on OA, and briefly present the 44 contributions that appear in this theme issue. OA research has clearly matured, and is continuing to do so. We hope that our readership will find that, when taken together, the articles that appear herein do indeed move us “Towards a broader perspective on ocean acidification research”.
Acute Thoracic Vascular Syndromes
Authors: Hayim Morris , Marone Louis A. , Lo Hao S. , Abujudeh Hani H.
Published: February 2016

Acute thoracic vascular syndromes are life-threatening. Systemic arterial injuries include intramural hematoma, aortic dissection, penetrating atherosclerotic ulcer, and acute aortic traumatic injuries. Pulmonary arterial injuries include bland thrombotic and septic emboli. CT angiography is the modality of choice for diagnosis. In aortic dissection, CTA can clearly differentiate the true and false lumen and demonstrate any extension into the major aortic branch vessels, and other complications including pericardial effusion/tamponade and end-organ ischemia within the kidneys. In intramural hematomas, CT angiography is preferred. A high index of suspicion is crucial. Any abnormality seen on chest radiography should prompt CT angiography for further characterization. Accompanying history is very helpful in clinching the diagnosis.
Pleural Collections and Emergencies
Authors: Shin Heeseop , Marone Louis , Abujudeh Hani H.
Published: February 2016

This chapter provides information on different types of pleural collections in the emergency setting. These include pleural effusion, pneumothorax, hemothorax, chylothorax, and empyema. Normal anatomy and physiology of the pleural space are important to understanding the development of pathology. Clinical information such as presenting symptoms, physical examination and laboratory findings, and intervention are discussed. Pertinent imaging findings, pitfalls, and differential diagnoses for each pleural collection are presented. Complications related to disease progression and/or management include tension pneumothorax, re-expansion pulmonary edema, and bronchopleural fistula.
Right Lower Quadrant Emergencies
Authors: Shenoy-Bhangle Anuradha , Gill Harman Singh , Baliyan Vinit , Abujudeh Hani H. , Kambadakone Avinash
Published: February 2016

Acute appendicitis is a major cause of right lower quadrant pain not only in the pediatric but also in the adult population. A close mimic in young adults is terminal ileitis of which, early presentation of Crohn disease is a common culprit. Although ultrasound is a good screening tool, computed tomography (CT) has gained popularity, especially when obese patient body habitus limits optimal evaluation. CT is also useful in accurate diagnosis of non-surgical conditions such as omental infarction or epiploic appendagitis that can mimic acute appendicitis. Typhilitis is largely a clinical diagnosis commonly presenting in an immunocompromised patient, and CT is a good imaging tool to further confirm this diagnosis or exclude other differentials of right lower quadrant pain. The following chapter (15) focuses on key imaging features of common conditions presenting as right lower quadrant pain in adults.
Epigastric Pain
Authors: Shenoy-Bhangle Anuradha , Baliyan Vinit , Abujudeh Hani H. , Kambadakone Avinash
Published: February 2016

Acute epigastric pain in adults can be the result of a variety of causes, ranging from reflux esophagitis to gastric and pancreatic carcinoma. Imaging plays a crucial role in the early evaluation and management of patients presenting with acute epigastric pain. In this chapter, we review the commonly encountered causes for epigastric pain and discuss their imaging characteristics.
Penile Emergencies
Authors: Uyeda Jennifer W. , Harisinghani Mukesh
Published: February 2016

Penile emergencies are rare and are usually secondary to vascular pathologies such as priapism and venous thrombosis, or penetrating or blunt trauma. Clinical history plays a large role in diagnosis of penile pathologies. Imaging is used for diagnostic confirmation and for characterization and assessment of penile trauma.
Trauma of the Lower Urinary Tract
Authors: Cruz-Romero Cinthia
Published: February 2016

Isolated traumatic ureteral injury must be considered in the differential diagnosis of blunt trauma. It is most commonly seen in the setting of underlying hidroureter caused by obstructive calculus. Diagnosis is established on computer tomography. The most common associated fracture to ureteral injury is pelvic fracture. The ureteropelvic junction (UPJ) is the most common site of disruption. A non-contrast acquisition before contrast must be performed. Periureteral collection, hematoma, and stranding may or may not be present, hence delayed excretory images should be acquired, and the complete ureter must be visualized. The differentiation of avulsion from complete ureteral tear is crucial. Found abnormalities should be correlated with clinical history and/or variants, such as presence of calculi, known duplications, and recent surgical procedures.
Emergencies of the Knee and Lower Leg, Part 1
Authors: Moy Matthew P. , Huang Ambrose J. , Abujudeh Hani H. , Chang Connie Y.
Published: February 2016

The knee is the largest joint in the human body and is a major weight-bearing joint of the lower extremity. It consists of the articulations of the femur, tibia, and patella and accompanying supporting soft tissue structures. The knee is particularly susceptible to trauma, given its location and role in ambulation. Knee trauma has been estimated as the chief complaint of over 650,000 emergency department visits in the United States annually.
Emergencies of the Knee and Lower Leg, Part 2
Authors: Moy Matthew P. , Huang Ambrose J. , Abujudeh Hani H. , Chang Connie Y.
Published: February 2016

The knee is the largest joint in the human body and is a major weight-bearing joint of the lower extremity. It consists of the articulations of the femur, tibia, and patella and accompanying supporting soft tissue structures. The knee is particularly susceptible to trauma given its location and role in ambulation. Knee trauma has been estimated as the chief complaint of over 650,000 emergency department visits in the United States annually. The clinical features are discussed in greater detail in the “Knee and Lower Leg Part 1” chapter. Soft-tissue injuries often result in a sensation of popping, joint clicking or catching, decreased range of motion, and joint instability. Joint effusion is common.
Visceral Venous Thrombosis Imaging and Intervention
Authors: Karcich Jenika , Patel Dhruv , Nicola Refky , Contractor Sohail
Published: February 2016

Visceral venous thrombosis is thrombosis of the visceral veins and includes thrombosis of the splenic, hepatic, portal, mesenteric, renal, and ovarian veins, among others. Thrombosis can be either acute or chronic and have variable clinical presentations. The pathophysiology, often distinct in each case, often includes hypercoagulable states. Due to the often ambiguous clinical presentation, imaging plays crucial role in the diagnosis of visceral thrombosis, with ultrasound often the first line of imaging study. Treatment options vary from anticoagulation alone to percutaneous endovascular and surgical interventions depending on site, acuteness, and etiology of the thrombosis. In this chapter, we discuss clinical features, anatomy, pathophysiology, approach to imaging studies, imaging differential, and crucial management considerations for Budd-Chiari syndrome (BCS), portal venous thrombosis, and renal and ovarian vein thrombosis.