bluuebunny/crossref_metadata_2025 huggingface dataset:
Physically active lessons in schools and their impact on physical activity, educational, health and cognition outcomes: a systematic review and meta-analysis
Authors: Norris Emma , van Steen Tommy , Direito Artur , Stamatakis Emmanuel
Published: October 2019

Objective

This review provides the first meta-analysis of the impact of physically active lessons on lesson-time and overall physical activity (PA), as well as health, cognition and educational outcomes.

Design

Systematic review and meta-analysis of controlled studies. Six meta-analyses pooled effects on lesson-time PA, overall PA, in-class educational and overall educational outcomes, cognition and health outcomes. Meta-analyses were conducted using the metafor package in R. Risk of bias was assessed using the Cochrane tool for risk of bias.

Data sources

PubMed, Embase, PsycINFO, ERIC and Web of Science, grey literature and reference lists were searched in December 2017 and April 2019.

Studies eligibility criteria

Physically active lessons compared with a control group in a randomised or non-randomised design, within single component interventions in general school populations.

Results

42 studies (39 in preschool or elementary school settings, 27 randomised controlled trials) were eligible to be included in the systematic review and 37 of them were included across the six meta-analyses (n=12 663). Physically active lessons were found to produce large, significant increases in lesson-time PA (d=2.33; 95% CI 1.42 to 3.25:k=16) and small, increases on overall PA (d=0.32; 95% CI 0.18 to 0.46:k=8), large, improvement in lesson-time educational outcomes (d=0.81; 95% CI 0.47 to 1.14:k=7) and a small improvement in overall educational outcomes (d=0.36; 95% CI 0.09 to 0.63:k=25). No effects were seen on cognitive (k=3) or health outcomes (k=3). 25/42 studies had high risk of bias in at least two domains.

Conclusion

In elementary and preschool settings, when physically active lessons were added into the curriculum they had positive impact on both physical activity and educational outcomes. These findings support policy initiatives encouraging the incorporation of physically active lessons into teaching in elementary and preschool setting.

Trial registration number

CRD42017076933.
Drug-related community issues and the required interventions in open drug scenes in Tehran, Iran: a qualitative study protocol
Authors: Saberi Zafarghandi Mohammad Bagher , Eshrati Sahar , Vameghi Meroe , Ranjbar Hadi , Arezoomandan Reza , Clausen Thomas , Waal Helge
Published: October 2019

Background and objectives

Many low-income and middle-income countries experience problems with open drug scenes and drug-related community issues (DRCIs). These experiences occur in settings with varying levels of health and law enforcement initiatives, and accordingly a range of approaches are implemented to curb the problem. Most of the published literature stems from Western and high-income societies. With this concern, the present study aims to describe a planned project to explore DRCIs in the open drug scenes of Tehran, including its typology, and predisposing and reinforcing factors. In addition, the study attempts to investigate the perceptions with respect to the required interventions and barriers to their accessibility.

Methods

To this end, the current study focuses on the Farahzad drug scene due to its structure and the difficult access to the scene by harm reduction providers. Data collection techniques encompass field observation, indepth interview and focus group discussion. Further, semistructured interviews are conducted with people who use drugs and other key informants who are engaged at this drug scene, including business, community, voluntary and statutory stakeholders, for an average of 90 min (average of 45 min for each part of the study). Furthermore, as a complementary method, field observation is performed regarding the themes of DRCIs at this scene. Then, focus group discussions are held to further describe the themes of DRCIs as well as to explore the required interventions, for an average of 90 min. Finally, the results are evaluated using qualitative content analysis.

Ethics and dissemination

Ethical approval for the study was obtained from the Ethics Committee of Iran University of Medical Sciences, Iran. Additionally, participants are to provide written informed consent. The findings of the study are expected to play a role in promoting the current intervention.
Presentation and healthcare delays among people with tuberculosis in London, and the impact on treatment outcome
Authors: Evenden Poppy , Roche Anita , Karo Basel , Balasegaram Sooria , Anderson Charlotte S
Published: October 2019

Background

A quarter of London’s pulmonary tuberculosis (TB) patients have over 4 months of delay. Late diagnosis increases disease severity and the risk of transmission. We aim to classify delays, identify associated risk factors and assess treatment outcome.

Methods

We conducted a retrospective cohort study using London surveillance data, 2012–2018 on adults aged ≥18 years with pulmonary TB. We defined presentation delay (days from symptom onset to first healthcare visit) and healthcare delay (first healthcare visit to treatment commencement) as dichotomous variables; positive delay being days equal or greater than the third quartile. We applied logistic regression models to identify risk factors associated with delays and treatment outcome at 12 months.

Results

Of 7216 people, 4539 reported presentation and 5193 healthcare delays. The third quartiles for presentation and healthcare delay were 84 and 61 days, respectively. Presentation delay was associated with female sex (adjusted OR (aOR)=1.21; 95% CI 1.04 to 1.39), increasing age (aOR=1.004; 95% CI 1.001 to 1.008), white compared to Asian ethnicity (aOR=1.35; 95% CI 1.12 to 1.62), previous imprisonment (aOR=1.66; 95% CI 1.22 to 2.26) and alcohol misuse (aOR=1.44; 95% CI 1.04 to 1.89). Healthcare delay was associated with female sex (aOR=1.39; 95% CI 1.21 to 1.59), increasing age (aOR=1.014; 95% CI 1.009 to 1.018) and white ethnicity (aOR=1.41; 95% CI 1.19 to 1.68). 16% of 5678 people with known outcome did not complete treatment. Neither delay was associated with non-completion (p value <0.05).

Conclusions

Female, white and older people with TB were more likely to experience both presentation and healthcare delays. Social risk factors were also associated with delay in presentation. Early diagnosis and treatment remain critical to reduce transmission, regardless of whether delay affected completion.
End-of-life care in intellectual disability: a retrospective cross-sectional study
Authors: Hunt Katherine , Bernal Jane , Worth Rhian , Shearn Julia , Jarvis Paul , Jones Edwin , Lowe Kathy , Madden Phil , Barr Owen , Forrester-Jones Rachel , Kroll Thilo , McCarron Mary , Read Sue , Todd Stuart
Published: October 2019

Background

Adults with intellectual disability (ID) experience inequality in access to healthcare that is considered to extend to end-of-life care. Their experiences of healthcare at the end of life and how these compare with the general population are unknown.

Aim

To describe the end-of-life care outcomes for adults with ID living in residential care in the UK using the VOICES-SF questionnaire and compare these with the general population.

Design

Nationwide population-based postbereavement survey.

Participants

38 ID care providers took part in the study. The supported over 13 000 people with ID. Over the 18-month period of data collection, 222 deaths were reported. The survey was completed, by care staff, for 157 (70.7%) of those deaths.

Results

Decedents had complex health, functional and behavioural needs. Death was unanticipated in a high proportion of cases. Quality of care provided across care settings was generally well rated. However, hospital care and care provided at the time of was less well rated, particularly in comparison with the general population. Respondents reported low levels of involvement in care and awareness of approaching death among adults with ID, and lower than in the general population.

Conclusions

Access to end-of-life care for adults with ID may be constrained by a failure to identify approaching the end of life. The high proportion of unexpected deaths in this population warrants further study. There is a need to increase and support the involvement of adults with ID to be active partners in planning care at the end of their lives.
Cretaceous flora and fauna of the Sustut Group near the Sustut River, northern British Columbia, Canada
Authors: Arbour Victoria M. , Evans David C. , Simon D. Jade , Cullen Thomas M. , Braman Dennis
Published: October 2019

A partial ornithischian dinosaur skeleton discovered near the Sustut River in 1971 has, to date, represented the only vertebrate fossil remains recovered from the Sustut Basin in northern British Columbia, Canada, but the geological provenance and age of this specimen has remained unclear. We provide new data on the age of this dinosaur specimen based on reconnaissance palaeontological prospecting along the Sustut River, and also report new vertebrate and plant fossils from this region. A skeletal fragment of a species of the turtle Basilemys Hay, 1902 was discovered at a site closely matching field notes describing the initial collection of the ornithischian dinosaur, suggesting that the new turtle fossil derives from the same locality as the dinosaur. Palynomorphs collected from this site include the marker taxon Pseudoaquilapollenites bertillonites (Sriv.), found in the lower Hell Creek Formation, and suggesting an age range of between 68.2 and 67.2 Ma for the locality. To the west of this locality we discovered multiple new fossil plant sites preserving wood and the leaves of Metasequoia Miki and several angiosperms, and one site preserved fronds resembling a species of the tree fern Coniopteris Brong., suggesting a Cenomanian or older age for sites in the area. The complex translational history of the Intermontane Terrane means that the newly discovered turtle may not represent a northern range extension for Basilemys, but it does represent one of the westernmost occurrences of this genus. The discovery of new vertebrate fossil remains in a region with relatively little accessible outcrop at present indicates the potential for future discoveries in the higher elevation outcrops of the Sustut Basin in this mountainous region of British Columbia.
Desiccation, dormancy, and storage of Pterocarya fraxinifolia (Juglandaceae) seeds: application in Hyrcanian and Colchian forest conservation
Authors: Wawrzyniak Mikołaj Krzysztof , Jasińska Anna Katarzyna , Chmielarz Paweł , Kozlowski Gregor
Published: October 2019

Pterocarya fraxinifolia (Poir.) Spach (Juglandaceae) is a model relict tree species native to South Caucasus and is a typical element of threatened riparian forests. Intensive land transformations, which are common in Transcaucasia, have resulted in loss of natural habitat and population decline of the species. One of the methods of ex situ conservation is seed banking. Cryopreservation in liquid nitrogen (−196 °C) is of particular interest, as it allows safe preservation of valuable plant genetic resources. However, the feasibility of seed cryopreservation is related to the desiccation tolerance and intrinsic composition of the seeds. In this study, we examined the physiological traits of Pterocarya fraxinifolia seeds, for which desiccation tolerance is unknown or controversial, and their feasibility for cryopreservation. Additionally, we tested stratification methods for dormancy assessment. Results showed that seeds survived desiccation to a moisture content of 2.8% with a germination rate of 64%. Stratification at a temperature of 3 °C for 8 weeks proved to be both fast and effective. Seed moisture content ranging from 2.8% to 18.1% was determined to be safe for cryopreservation. There was no difference in seedling emergence in seeds stored for 1 year regardless of the storage temperature (−3, −18, or −196 °C). Based on our results, Pterocarya fraxinifolia seeds can be classified as orthodox. This study demonstrates for the first time the feasibility of cryopreserving Pterocarya fraxinifolia seeds.
Forward–backward asymmetry in the gauge-Higgs unification at the International Linear Collider
Authors: Funatsu Shuichiro
Published: October 2019

The signals of the $$SO(5)\times U(1)$$SO(5)×U(1) gauge-Higgs unification model at the International Linear Collider are studied. In this model, Kaluza–Klein modes of the neutral gauge bosons affect fermion pair productions. The deviations of the forward–backward asymmetries of the $$e^+e^-\rightarrow \bar{b}b$$e+e-→b¯b, $$\bar{t}t$$t¯t processes from the standard model predictions are clearly seen by using polarised beams. The deviations of these values are predicted for two cases, the bulk mass parameters of quarks are positive and negative case.
Dynamical instability of anisotropic homogeneous cylinder
Authors: Sharif M. , Ama-Tul-Mughani Qanitah
Published: October 2019

In this paper, we consider a non-static cylindrically symmetric self-gravitating system with anisotropic matter configuration and investigate its stability regions by using a homogenous model. We establish perturbed form of dynamical equations by using Eulerian and Lagrangian approaches. The conservation of baryon number is applied to obtain adiabatic index as well as perturbed pressure. A variational principle is used to find characteristic frequency which helps to compute the instability criteria. It is found that dynamical instability can be prevented till the radius of a cylinder exceeds the limit R[Formula: see text]18. We conclude that the system becomes unstable against radial oscillations as the radial pressure increases relative to tangential pressure.
The g factor of an electron in hydrogenlike carbon and the precision determination of the electron mass
Authors: Sapirstein Jonathan
Published: October 2019

The role of the bound electron Green function in the recent high precision determination of the electron mass is discussed. Emphasis is placed on the connection to Schwinger’s use of such Green functions in his early work establishing the modern form of QED, his calculation of leading binding corrections, and his work on synchrotron radiation.
Unruh acceleration radiation revisited
Authors: Ben-Benjamin J. S. , Scully M. O. , Fulling S. A. , Lee D. M. , Page D. N. , Svidzinsky A. A. , Zubairy M. S. , Duff M. J. , Glauber R. , Schleich W. P. , Unruh W. G.
Published: October 2019

When ground-state atoms are accelerated and the field with which they interact is in its normal vacuum state, the atoms detect Unruh radiation. We show that atoms falling into a black hole emit acceleration radiation which, under appropriate initial conditions (Boulware vacuum), has an energy spectrum which looks much like Hawking radiation. This analysis also provides insight into the Einstein principle of equivalence between acceleration and gravity. The Unruh temperature can also be obtained by using the Kubo–Martin–Schwinger (KMS) periodicity of the two-point thermal correlation function, for a system undergoing uniform acceleration; as with much of the material in this paper, this known result is obtained with a twist.
The extended Zn-Heisenberg ferromagnet model
Authors: Gao Bian , Jiang Nana , Cui Jifeng , Yan Zhaowen
Published: October 2019

By virtue of taking values in a commutative subalgebra [Formula: see text] of Lie algebra [Formula: see text], we construct the [Formula: see text]-Heisenberg ferromagnet model which contains many Heisenberg ferromagnet-type equations. Moreover, we investigate the integrable properties of the [Formula: see text]-Heisenberg ferromagnet model. In terms of the gauge transformation, the gauge equivalent counterpart of the [Formula: see text]-Heisenberg ferromagnet model has been presented. Based on the differential geometry of curves and surfaces, the corresponding geometrical equivalence between the [Formula: see text]-Heisenberg ferromagnet model and [Formula: see text]-nonlinear Schrödinger equation has also been established. Furthermore, we also discuss the [Formula: see text]-generalized inhomogeneous Heisenberg ferromagnet model.
Noise test method for dual-gate MOSFET device
Authors: Jia Xiaofei , Chen Wenhao , Ding Bing , He Liang
Published: October 2019

In recent years, with the development of mesoscopic physics and nanoelectronics, the research on noise and testing technology of electronic components has been developed. It is well known that noise can characterize the transmission characteristics of carriers in nanoscale electronic components. With the continuous shrinking of the device size, the carrier transport of nanoscale MOSFET devices has been gradually transformed from the traditional drift-diffusion to become the quasi-ballistic or ballistic transport, and its current noise contains granular and thermal noise. The paper by Jeon et al. [The first observation of shot noise characteristics in 10-nm scale MOSFETs, in Proc. 2009 Symp. VLSI Technology (IEEE, Honolulu, 2009), pp. 48–49] presents the variation relation of 20 nm MOSFET current noise with source–drain current and voltage, and its current noise characteristic is between thermal noise and shot noise, so 20 nm MOSFET current noise is shot noise and thermal noise. The paper by Navid et al. [J. Appl. Phys. 101 (2007) 124501] shows through simulation that the 60 nm MOSFET current noise is suppressed shot noise and thermal noise. At present, the current noise has seriously affected the basic performance of the device, thus the circuit cannot work normally. Therefore, it is necessary to study the generation mechanism and characteristics of current noise in electronic components so as to suppress device noise, which can not only realize the reduction of device noise, but also play a positive role in the work-efficiency, life-span and reliability of electronic components.
Lump solitons and interaction phenomenon to a (3+1)-dimensional Kadomtsev–Petviashvili–Boussinesq-like equation
Authors: Liu Na , Liu Yansheng
Published: October 2019

This paper studies lump solutions and interaction solutions for a (3[Formula: see text]+[Formula: see text]1)-dimensional Kadomtsev–Petviashvili–Boussinesq-like equation. With the help of symbolic computation and Hirota’s bilinear form, we obtain bright–dark lump solutions, lump-soliton solutions, and lump-kink solutions. Meanwhile, the dynamics of the obtained three classes of solutions are analyzed and exhibited mathematically and graphically. These results provide us with useful information to grasp the propagation processes of nonlinear waves.
Evaluation of Statistics for Macrodiversity Systems Under the Influence of Specific Single Shadowing and Complex Fading
Authors: Milic Miljana , Krstic Dragana , Stefanovic Mihajlo , Nikolic Petar
Published: October 2019

Wireless signals often propagate in spaces containing large and small obstacles that affect the quality of such radiation. Obstacles cause a nonnegligible loss of the propagated power. The degradation of the signal quality is described by introducing fading and shadowing effects. A case of a wireless communication system that consists of a macro-level component represented by the selection combiner (SC) and two micro-level components consisting of the maximal ratio combiners (MRC) with [Formula: see text] branches is studied in this paper. The MRC component assumes the presence of a single-base station. The received signal is disturbed by simultaneous impact of the multipath Nakagami-[Formula: see text] fading and gamma shadowing. Consequently, the envelope is described by generalized-[Formula: see text] density function. On the other hand, SC component assumes the presence of two base stations, where the average power of the received signal is described using gamma distribution. The exact closed-form expression is obtained for probability density function of the signal at the output of the system, followed by the corresponding outage probability (Pout). Calculations are depicted graphically expressing influences of different fading values as well as the signal parameters.
Switching Characteristics of a Locally-Active Memristor with Binary Memories
Authors: Ying Jiajie , Wang Guangyi , Dong Yujiao , Yu Simin
Published: October 2019

A number of important applications would benefit from the introduction of locally-active memristors, which is defined to be any memristor that exhibits negative differential memristance for at least a voltage or a current applied to the memristor. Two leading examples are emerging nonvolatile memory based on memristor-based crossbar array architectures, and neural networks that exhibit improved computational complexity when operated at the edge of chaos. In this paper, a novel locally-active memristor model is presented for exploring the nonvolatile and switching mechanism of the memristor and the influence of local activity on the complexity of nonlinear circuits. We find that the memristor possesses three locally-active regions in its DC [Formula: see text]–[Formula: see text] plot and two asymptotically stable states (equilibrium points) on its power-off plot (POP) where voltage [Formula: see text], implying that the memristor is bistable, which can be used as a nonvolatile binary memory or binary switch. We also find the mechanism and the rule of switching between the two stable states by applying a single square voltage pulse of appropriate pulse width and pulse amplitude. We show that it is always possible to switch from one stable state to another of the memristor with an appropriate pulse amplitude and a pulse width, and that there is a trade-off between the voltage pulse amplitude and the pulse width for the faster switching between the two equilibrium points. We also show that fast switching between the two states is possible by using a periodic bipolar narrow pulse sequence. Local activity depends on the capability of a memristor circuit to amplify infinitesimal fluctuations in energy. Based on this principle, we designed a simplest chaotic oscillator that utilizes only three components in parallel: the proposed locally-active memristor, a linear capacitor and an inductor, which can oscillate around an equilibrium point located on its DC [Formula: see text]–[Formula: see text] plot. Its dynamic characteristics are verified by theoretical analyses, simulations and DSP experiments.
Bifurcation Analysis in a Diffusive Mussel-Algae Model with Delay
Authors: Shen Zuolin , Wei Junjie
Published: October 2019

In this paper, we consider the dynamics of a delayed reaction–diffusion mussel-algae system subject to Neumann boundary conditions. When the delay is zero, we show the existence of positive solutions and the global stability of the boundary equilibrium. When the delay is not zero, we obtain the stability of the positive constant steady state and the existence of Hopf bifurcation by analyzing the distribution of characteristic values. By using the theory of normal form and center manifold reduction for partial functional differential equations, we derive an algorithm that determines the direction of Hopf bifurcation and the stability of bifurcating periodic solutions. Finally, some numerical simulations are carried out to support our theoretical results.
Bifurcations of Time-Delay-Induced Multiple Transitions Between In-Phase and Anti-Phase Synchronizations in Neurons with Excitatory or Inhibitory Synapses
Authors: Li Li , Zhao Zhiguo , Gu Huaguang
Published: October 2019

Time-delay-induced synchronous behaviors and synchronization transitions have been widely investigated for coupled neurons, and they play important roles for physiological functions. In the present study, time-delay-induced synchronized subthreshold oscillations were simulated, and the bifurcations underlying the synchronized behaviors were identified for a pair of coupled FitzHugh–Nagumo neurons. Multiple transitions between in-phase and anti-phase synchronizations induced by the time delay were simulated for the inhibitory and excitatory couplings. Subcritical or supercritical Hopf bifurcations and the stability of the Hopf-bifurcating periodic subthreshold oscillations were acquired using center manifold reduction and normal form theory. The in-phase or anti-phase synchronizations of the stable periodic subthreshold oscillations, which appear for multiple values of the time delay, were interpreted with the related eigenspace. The distributions of the different dynamical behaviors, including the synchronizations and bifurcations in the two-parameter plane of the time delay and coupling strength, were acquired for both types of synapses, and the different roles of the inhibitory and excitatory couplings on the synchronization transitions were compared.
Nonlinear Dynamic Analysis of Functionally Graded Graphene Reinforced Composite Truncated Conical Shells
Authors: Wang Aiwen , Pang Youqing , Zhang Wei , Jiang Pengcheng
Published: October 2019

Functionally graded (FG) graphene reinforced composite (GRC) is a new class of advanced composite materials. In GRC, several layers of graphene platelets (GPLs) are randomly or uniformly dispersed in matrix. These GPLs have uniform arrangement, or are arranged with gradient, in the direction of thickness in accordance with three different graphene distribution rules. In this study, the nonlinear dynamic analysis of FG GRC truncated conical shells, subjected to a combined action of transverse excitation and axial force, is performed using the first shear deformation theory (FSDT). Estimation of equivalent Young’s modulus of the composites is calculated using a modified Halpin–Tsai model. In addition, a partial differential equation model is developed based on the Hamilton principle and nonlinear strain-displacement relationship. The Galerkin method and the fourth-order Runge–Kutta method are used to solve the equation. The dimensionless linear natural frequency of an FG GRC truncated conical shell is calculated by the Rayleigh–Ritz method and compared with available results in the literature to verify the accuracy of the present model. Simultaneously, significant effects of the different parameters, such as the total layer numbers, semi-vertex angles, GPLs weight fractions, distribution patterns and the length-to-thickness ratios, on the nonlinear dynamics including bifurcation and chaos of FG GRC truncated conical shells are investigated.
Spatiotemporal Dynamics in Reaction–Diffusion Neural Networks Near a Turing–Hopf Bifurcation Point
Authors: Lin Jiazhe , Xu Rui , Tian Xiaohong
Published: October 2019

Since the electromagnetic field of neural networks is heterogeneous, the diffusion phenomenon of electrons exists inevitably. In this paper, we investigate the existence of Turing–Hopf bifurcation in a reaction–diffusion neural network. By the normal form theory for partial differential equations, we calculate the normal form on the center manifold associated with codimension-two Turing–Hopf bifurcation, which helps us understand and classify the spatiotemporal dynamics close to the Turing–Hopf bifurcation point. Numerical simulations show that the spatiotemporal dynamics in the neighborhood of the bifurcation point can be divided into six cases and spatially inhomogeneous periodic solution appears in one of them.
Electrical Mode Transition of Hybrid Neuronal Model Induced by External Stimulus and Electromagnetic Induction
Authors: Liu Ying , Ma Jun , Xu Ying , Jia Ya
Published: October 2019

Based on a hybrid neuronal model of the Hindmarsh–Rose (HR) model (the slow negative feedback dynamics) with the Wilson model (the fast variable dynamics), the discharge modes of neurons are studied by using bifurcation analysis. When the hybrid neuronal model is driven by external stimulus current, the hybrid neuronal model is capable of simulating an extensive range of bursting patterns with different systemic parameters. With the increase of external stimulus, the multiple discharge patterns of neurons arise, and the electrical modes of the neurons appear for successive transitions. When the hybrid neuronal model is driven by electromagnetic induction, the electrical activities of the neurons have different responses to the variations in the amplitude and the angular frequency of high and low frequency electromagnetic radiations. It is found that the neuronal discharge activity is transformed from chaotic state to periodic state by increasing the angular frequency, and the firing pattern of neuron can be shifted from the bursting state to chaotic state by increasing the amplitude of the low frequency signal.
Synthesis of Gamma-Alumina Nanopowders Using Waste Metal Aluminum and Stability Surfactants
Authors: Nazari Sabereh , Nazari Sadegh , Mansourizadeh Fariba , Karimi Gholamreza
Published: October 2019

In this study, high purity gamma-alumina nanopowders with crystalline structures have been prepared via a sol–gel process by waste metal aluminum, HCl, NaOH, Polyethylene glycol (PEG) and polyvinyl alcohol (PVA). Polyethylene glycol and polyvinyl alcohol have been used as stabilizing agents. The characterization of the samples has been performed utilizing XRD, FTIR, SEM, N2 adsorption/desorption techniques. Prepared samples of gamma-alumina at 800∘C with PEG has an average crystallite size of 2.58[Formula: see text]nm, average particle size of 21[Formula: see text]nm, specific surface area (SSA) of 65.55[Formula: see text]m2/g, and pore volume of [Formula: see text]0.06[Formula: see text]cm3/g. The average crystallite size of 3.07[Formula: see text]nm, average particle size of 31[Formula: see text]nm, specific surface area of 131.25[Formula: see text]m2/g, and pore volume of [Formula: see text]0.14[Formula: see text]cm3/g, were obtained using PVA surfactant.
A Survey on Representation Learning Efforts in Cybersecurity Domain
Authors: Usman Muhammad , Jan Mian Ahmad , He Xiangjian , Chen Jinjun
Published: October 2019

In this technology-based era, network-based systems are facing new cyber-attacks on daily bases. Traditional cybersecurity approaches are based on old threat-knowledge databases and need to be updated on a daily basis to stand against new generation of cyber-threats and protect underlying network-based systems. Along with updating threat-knowledge databases, there is a need for proper management and processing of data generated by sensitive real-time applications. In recent years, various computing platforms based on representation learning algorithms have emerged as a useful resource to manage and exploit the generated data to extract meaningful information. If these platforms are properly utilized, then strong cybersecurity systems can be developed to protect the underlying network-based systems and support sensitive real-time applications. In this survey, we highlight various cyber-threats, real-life examples, and initiatives taken by various international organizations. We discuss various computing platforms based on representation learning algorithms to process and analyze the generated data. We highlight various popular datasets introduced by well-known global organizations that can be used to train the representation learning algorithms to predict and detect threats. We also provide an in-depth analysis of research efforts based on representation learning algorithms made in recent years to protect the underlying network-based systems against current cyber-threats. Finally, we highlight various limitations and challenges in these efforts and available datasets that need to be considered when using them to build cybersecurity systems.
A Survey of Metaprogramming Languages
Authors: Lilis Yannis , Savidis Anthony
Published: October 2019

Metaprogramming is the process of writing computer programs that treat programs as data, enabling them to analyze or transform existing programs or generate new ones. While the concept of metaprogramming has existed for several decades, activities focusing on metaprogramming have been increasing rapidly over the past few years, with most languages offering some metaprogramming support and the amount of metacode being developed growing exponentially. In this article, we introduce a taxonomy of metaprogramming languages and present a survey of metaprogramming languages and systems based on the taxonomy. Our classification is based on the metaprogramming model adopted by the language, the phase of the metaprogram evaluation, the metaprogram source location, and the relation between the metalanguage and the object language.
Seeing the Invisible
Authors: Le Ngo Anh Cat , Phan Raphaël C.-W.
Published: October 2019

The latest techniques in video motion magnification and relevant small motion analysis are surveyed. The main motion magnification techniques are discussed in chronological fashion, highlighting the inherent limitations of predecessor techniques in comparison with subsequent variants. The focus is then shifted to the specific stages within the motion magnification framework to discuss advancements that have been proposed in the literature, namely for spatial decomposition and for emphasizing, representing, and distinguishing different motion signals. The survey concludes with a treatment of different problems in varying application contexts that have benefited from motion magnification and small motion analysis.
Document Layout Analysis
Authors: Binmakhashen Galal M. , Mahmoud Sabri A.
Published: October 2019

Document layout analysis (DLA) is a preprocessing step of document understanding systems. It is responsible for detecting and annotating the physical structure of documents. DLA has several important applications such as document retrieval, content categorization, text recognition, and the like. The objective of DLA is to ease the subsequent analysis/recognition phases by identifying the document-homogeneous blocks and by determining their relationships. The DLA pipeline consists of several phases that could vary among DLA methods, depending on the documents’ layouts and final analysis objectives. In this regard, a universal DLA algorithm that fits all types of document-layouts or that satisfies all analysis objectives has not been developed, yet. In this survey paper, we present a critical study of different document layout analysis techniques. The study highlights the motivational reasons for pursuing DLA and discusses comprehensively the different phases of the DLA algorithms based on a general framework that is formed as an outcome of reviewing the research in the field. The DLA framework consists of preprocessing, layout analysis strategies, post-processing, and performance evaluation phases. Overall, the article delivers an essential baseline for pursuing further research in document layout analysis.
Tight Bounds for Undirected Graph Exploration with Pebbles and Multiple Agents
Authors: Disser Yann , Hackfeld Jan , Klimm Max
Published: October 2019

We study the problem of deterministically exploring an undirected and initially unknown graph with
n
vertices either by a single agent equipped with a set of pebbles or by a set of collaborating agents. The vertices of the graph are unlabeled and cannot be distinguished by the agents, but the edges incident to a vertex have locally distinct labels. The graph is explored when all vertices have been visited by at least one agent. In this setting, it is known that for a single agent without pebbles Θ(log
n
) bits of memory are necessary and sufficient to explore any graph with at most
n
vertices. We are interested in how the memory requirement decreases as the agent may mark vertices by dropping and retrieving distinguishable pebbles or when multiple agents jointly explore the graph. We give tight results for both questions showing that for a single agent with constant memory Θ(log log
n
) pebbles are necessary and sufficient for exploration. We further prove that using collaborating agents instead of pebbles does not help as Θ(log log
n
) agents with constant memory each are necessary and sufficient for exploration.

For the upper bounds, we devise an algorithm for a single agent with constant memory that explores any
n
-vertex graph using
O
(log log
n
) pebbles, even when
n
is not known
a priori
. The algorithm terminates after polynomial time and returns to the starting vertex. We further show that the algorithm can be realized with additional constant-memory agents rather than pebbles, implying that
O
(log log
n
) agents with constant memory can explore any
n
-vertex graph. For the lower bound, we show that the number of agents needed for exploring any graph with at most
n
vertices is already Ω(log log
n
) when we allow each agent to have at most
O
((log
n
)
1
-ε) bits of memory for any ε > 0. Our argument also implies that a single agent with sublogarithmic memory needs Θ(log log
n
) pebbles to explore any
n
-vertex graph.
Deciding Context Unification
Authors: Jeż Artur
Published: October 2019

In first-order term unification, variables represent well-formed terms over a given signature, and we are to solve equations built using function symbols from the signature and such variables; this problem is well-known to be decidable (in linear time). In second-order term unification, the variables take arguments (i.e., other terms) and a substitution uses those arguments an arbitrary number of times; for instance, an equation
f
(
X
(
c
),
X
(
c
)) =
X
(
f
(
c
,
c
)) has a solution
X
= •, where • is a special symbol denoting the place in which the argument is substituted. Under this substitution, both sides evaluate to
f
(
c
,
c
). There are other solutions, for instance
X
=
f
(•,•), which evaluates both sides to
f
(
f
(
c
,
c
),
f
(
c
,
c
)); in general, a solution that evaluates both sides to full binary tree of arbitrary height is easy to construct. Second-order unification is in general undecidable. Context unification is a natural problem in between first- and second-order unification—we deal with equations over terms, the variables take arguments, but we restrict the set of solutions: The argument is used exactly once. Formally, contexts are terms with exactly one occurrence of the special symbol • and in context unification, we are given an equation over terms with variables representing contexts and ask about the satisfiability of this equation. For instance, when the aforementioned equation
f
(
X
(
c
),
X
(
c
)) =
X
(
f
(
c
,
c
)) is treated as a context unification problem, then it has exactly one solution:
X
= •. Other substitutions that are solutions of it as an instance of the second-unification problem, say
X
=
f
(•, •), are not valid, as • is used more than once. Context unification also generalizes satisfiability of word equations, which is decidable (in PSPACE). The decidability status of context unification remained unknown for almost two decades. In this article, we show that context unification is in PSPACE (in EXPTIME , when tree regular constraints are also allowed). Those results are obtained by extending the recently developed recompression technique, which was previously defined for strings and used to obtain a new PSPACE algorithm for satisfiability of word equations. In this article, the technique is generalized to trees, and the corresponding algorithm is generalized from word equations to context unification. The idea of recompression is to apply simple compression rules (replacing pairs of neighboring function symbols) to the solution of the context equation; to this end, we appropriately modify the equation (without the knowledge of the actual solution) so compressing the solution can be simulated by compressing parts of the equation. It is shown that if the compression operations are appropriately chosen, then the size of the instance is polynomial during the whole algorithm, thus giving a PSPACE-upper bound.
A Survey on Interdependent Privacy
Authors: Humbert Mathias , Trubert Benjamin , Huguenin Kévin
Published: October 2019

The privacy of individuals does not only depend on their own actions and data but may also be affected by the privacy decisions and by the data shared by other individuals. This interdependence is an essential aspect of privacy and ignoring it can lead to serious privacy violations. In this survey, we summarize and analyze research on interdependent privacy risks and on the associated (cooperative and non-cooperative) solutions. We also demonstrate that interdependent privacy has been studied in isolation in different research communities. By doing so, we systematize knowledge on interdependent privacy research and provide insights on how this research should be conducted and which challenges it should address.
Survey of Text-based Epidemic Intelligence
Authors: Joshi Aditya , Karimi Sarvnaz , Sparks Ross , Paris Cécile , Macintyre C. Raina
Published: October 2019

Epidemic intelligence deals with the detection of outbreaks using formal (such as hospital records) and informal sources (such as user-generated text on the web) of information. In this survey, we discuss approaches for epidemic intelligence that use textual datasets, referring to it as “text-based epidemic intelligence.” We view past work in terms of two broad categories: health mention classification (selecting relevant text from a large volume) and health event detection (predicting epidemic events from a collection of relevant text). The focus of our discussion is the underlying computational linguistic techniques in the two categories. The survey also provides details of the state of the art in annotation techniques, resources, and evaluation strategies for epidemic intelligence.
A Survey on End-Edge-Cloud Orchestrated Network Computing Paradigms
Authors: Ren Ju , Zhang Deyu , He Shiwen , Zhang Yaoxue , Li Tao
Published: October 2019

Sending data to the cloud for analysis was a prominent trend during the past decades, driving cloud computing as a dominant computing paradigm. However, the dramatically increasing number of devices and data traffic in the Internet-of-Things (IoT) era are posing significant burdens on the capacity-limited Internet and uncontrollable service delay. It becomes difficult to meet the delay-sensitive and context-aware service requirements of IoT applications by using cloud computing alone. Facing these challenges, computing paradigms are shifting from the centralized cloud computing to distributed edge computing. Several new computing paradigms, including Transparent Computing, Mobile Edge Computing, Fog Computing, and Cloudlet, have emerged to leverage the distributed resources at network edge to provide timely and context-aware services. By integrating end devices, edge servers, and cloud, they form a hierarchical IoT architecture, i.e., End-Edge-Cloud orchestrated architecture to improve the performance of IoT systems. This article presents a comprehensive survey of these emerging computing paradigms from the perspective of end-edge-cloud orchestration. Specifically, we first introduce and compare the architectures and characteristics of different computing paradigms. Then, a comprehensive survey is presented to discuss state-of-the-art research in terms of computation offloading, caching, security, and privacy. Finally, some potential research directions are envisioned for fostering continuous research efforts.
Flexible organization of grip force control during movement frequency scaling
Authors: Grover Francis M. , Schwab Sarah M. , Silva Paula L. , Lorenz Tamara , Riley Michael A.
Published: October 2019

The grip force applied to maintain grasp of a handheld object has been typically reported as tightly coupled to the load force exerted by the object as it is actively manipulated, occurring proportionally and consistently in phase with changes in load force. However, continuous grip force-load force coupling breaks down when overall load force levels and oscillation amplitudes are lower (Grover F, Lamb M, Bonnette S, Silva PL, Lorenz T, Riley MA. Exp Brain Res 236: 2531–2544, 2018) or more predictable (Grover FM, Nalepka P, Silva PL, Lorenz T, Riley MA. Exp Brain Res 237: 687–703, 2019). Under these circumstances, grip force is instead only intermittently coupled to load force; continuous coupling is prompted only when load force levels or variations become sufficiently high or unpredictable. The current study investigated the nature of the transition between continuous and intermittent modes of grip force control by scaling the load force level and the oscillation amplitude continuously in time by means of scaling the required frequency of movement oscillations. Participants grasped a cylindrical object between the thumb and forefinger and oscillated their arm about the shoulder in the sagittal plane. Oscillation frequencies were paced with a metronome that scaled through an ascending or descending frequency progression. Due to greater accelerations, faster frequencies produced greater overall load force levels and more pronounced load oscillations. We observed smooth but nonlinear transitions between clear regimes of intermittent and continuous grip force-load force coordination, for both scaling directions, indicating that grip force control can flexibly reorganize as parameters affecting grasp (e.g., variations in load force) change over time.

NEW & NOTEWORTHY Grip force (GF) is synchronously coupled to changing load forces (LF) during object manipulation when LF levels are high or unpredictable, but only intermittently coupled to LF during less challenging grasp conditions. This study characterized the nature of transitions between synchronous and intermittent GF-LF coupling, revealing a smooth but nonlinear change in intermittent GF modulation in response to continuous scaling of LF amplitude. Intermittent, “drift-and-act” control may provide an alternative framework for understanding GF-LF coupling.
Evaluation of Copeptin during Pulmonary Exacerbation in Cystic Fibrosis
Authors: Wojsyk-Banaszak I. , Sobkowiak P. , Jończyk-Potoczna K. , Narożna B. , Langwiński W. , Szczepanik M. , Kycler Z. , Bręborowicz A. , Szczepankiewicz A.
Published: October 2019

Copeptin was found to be a stable biomarker of inflammation and stress response in cardiac, renal, metabolic, and respiratory conditions such as pneumonia. The aim of this study was to investigate the copeptin levels in biological fluids (serum and sputum supernatant) of cystic fibrosis pediatric patients during pulmonary exacerbation and remission and to investigate the possible influence of copeptin levels on disease severity and quality of life. Copeptin serum concentrations were measured in 28 pediatric cystic fibrosis (CF) patients: 13 in stable condition and 15 during pulmonary exacerbation. In 10 CF patients, copeptin was also measured in the sputum. In all the patients, we assessed complete blood count, BMI, sputum culture, lung function, and chest imaging (with Brasfield score). The severity of symptoms was assessed using the Shwachman-Kulczycki (SK) score, and the quality of life was assessed with the Cystic Fibrosis Quality of Life Questionnaire-Revised (CFQ-R). Copeptin concentrations in serum and sputum supernatant was measured using an ELISA kit. Statistical analysis was done in Statistica v.12. Serum and sputum copeptin levels were higher in CF patients during pulmonary exacerbation than in a stable period, but the differences were not significant (p=0.58 and p=0.13, respectively). Copeptin did not correlate significantly with any clinical, laboratory, or spirometry markers of exacerbation. There was, however, a significant inverse correlation between the serum copeptin level and symptoms severity (r=‐0.77, p=0.008) and radiological changes (r=‐0.5626, p=0.036) during pulmonary exacerbation in pediatric CF patients. Copeptin also inversely correlated with the quality of life domains in CF patients: vitality and eating habits, mostly loss of appetite (p=0.031 and p=0.016, respectively). Copeptin may be useful to identify patients with a higher risk of deterioration to improve their outcomes.