bluuebunny/crossref_metadata_2025 huggingface dataset:
Higher-Order Analysis of Kinematic Singularities of Lower Pair Linkages and Serial Manipulators
Authors: Müller Andreas
Published: November 2017

Kinematic singularities of linkages are configurations where the differential mobility changes. Constraint singularities are critical points of the constraint mapping defining the loop closure constraints. Configuration space (c-space) singularities are points where the c-space ceases to be a smooth manifold. These singularity types are not identical and can neither be distinguished nor identified by simply investigating the rank deficiency of the constraint Jacobian (linear dependence of joint screws). C-space singularities are reflected by the c-space geometry. In a previous work, a kinematic tangent cone was introduced as an approximation of the c-space, defined as the set of tangents to smooth curves in c-space. Identification of kinematic singularities amounts to analyze the local geometry of the set of critical points. As a computational means, a kinematic tangent cone to the set of critical points is introduced in terms of Jacobian minors. Closed form expressions for the derivatives of the minors in terms of Lie brackets of joint screws are presented. A computational method is introduced to determine a polynomial system defining the kinematic tangent cone. The paper complements the recently proposed mobility analysis using the tangent cone to the c-space. This allows for identifying c-space and kinematic singularities as long as the solution set of the constraints is a real variety. The introduced approach is directly applicable to the higher-order analysis of forward kinematic singularities of serial manipulators. This is briefly addressed in the paper.
Light absorption and scattering of 40–170 nm gold nanoparticles on glass substrates
Authors: Flatabø Ranveig , Holm Vårin R. A. , Eidsvåg Håkon , Holst Bodil , Greve Martin M.
Published: November 2017

The localized surface plasmon resonance (LSPR) effect in metal nanoparticles is important for many applications ranging from detectors and sensors to photovoltaic devices. The LSPR wavelength is sensitive to the shape, size, surface condition, and surrounding environment. Therefore, it is important to compare the optical properties of metal nanoparticles of nominally similar dimensions and external conditions, but fabricated with different techniques. Here, a systematic study of the optical properties of large, periodic arrays (3 × 3 mm) of cylindrical, gold nanoparticles with diameters ranging from 39 ± 4 nm to 167 ± 5 nm and a height of 25 ± 1 nm is presented. The large arrays allow us to investigate the optical properties using an integrating sphere setup collecting the light scattered and absorbed by the nanoparticles. To the best of our knowledge, such a setup has not been used previously for electron beam lithography (EBL) fabricated samples mainly due the large sample area required. The authors compare our results with relevant literature and find a good agreement, which confirms the expected reproducibility of EBL. Further, the authors compare our absorption and scattering measurements with previous absorption and scattering measurements on large arrays of gold nanoparticles prepared on glass using hole-mask colloidal lithography. Finally, a comparison with simulations using a finite difference time domain software package (Lumerical, Inc.) is presented. The simulation results matches well with experimental results and are also supporting and detailing our comparison with published literature. The authors find a good agreement between the two fabrication methods. The small deviations found can be contributed to differences in the particle size and density distributions.
Not All Doctoral Programs Are Created Equally
Authors: James Jeffrey D.
Published: November 2017

The 2017 Earle F. Zeigler Lecture Award presented in Denver, CO, addressed doctoral training in Sport Management programs. A review of the doctoral-granting degree programs listed on the website of the North American Society for Sport Management was completed. The review addressed the following three points: (a) number of hours required to earn a doctoral degree; (b) number of credit hours required for research tools, methods, and/or inquiry courses; and (c) whether program requirements included philosophy of science and/or philosophy of inquiry courses. The range of required hours for degree completion was 45–80. The number of required hours for research tools, methods, and/or inquiry ranged from 9 to 26. Four programs included specific content on the philosophy of science and/or inquiry. Concerns regarding the breadth, and to some degree the depth, of training were presented. Suggestions for action at the local level were shared as part of the conclusion.
Livestock drove ancient Old World inequality
Authors: Wade Lizzie
Published: November 2017

New World societies without draft animals had smaller gaps between haves and have-nots
Oldest images of dogs show hunting, leashes
Authors: Grimm David
Published: November 2017

Saudi find offers a window into how dogs helped humans survive in harsh conditions
Tunable excitons in bilayer graphene
Authors: Ju Long , Wang Lei , Cao Ting , Taniguchi Takashi , Watanabe Kenji , Louie Steven G. , Rana Farhan , Park Jiwoong , Hone James , Wang Feng , McEuen Paul L.
Published: November 2017

Pairing up electrons and holes in bilayer graphene

Excitons—bound pairs of electron and holes in solids—can be harnessed for optoelectronic applications. Being able to tune the exciton energy would bring functional flexibility to such devices. Although tunable excitons have been predicted to form in bilayer graphene, observing them experimentally has been difficult. Ju
et al.
used high-quality bilayer graphene samples sandwiched between layers of hexagonal boron nitride to observe excitons in this material. Exciton energy was tuned across a large range by controlling the gate voltages.

Science
, this issue p.
907
Self-assembling peptide semiconductors
Authors: Tao Kai , Makam Pandeeswar , Aizen Ruth , Gazit Ehud
Published: November 2017

Peptide-based semiconductors

For semiconductors, one often thinks of inorganic materials, such as doped silicon, or aromatic organic polymers and small molecules. Tao
et al.
review progress in making semiconductors based on self-assembling short peptides. The structures that form show extensive π and hydrogen bonding leading to a range of semiconductor properties, which can be tuned through doping or functionalization of the peptide sequences. These materials may shed light on biological semiconductors or provide an alternative for constructing biocompatible and therapeutic materials.

Science
, this issue p.
aam9756
Small vulnerable sets determine large network cascades in power grids
Authors: Yang Yang , Nishikawa Takashi , Motter Adilson E.
Published: November 2017

The domino effect in power failure

Sometimes a power failure can be fairly local, but other times, a seemingly identical initial failure can cascade to cause a massive and costly breakdown in the system. Yang
et al.
built a model for the North American power grid network based on samples of data covering the years 2008 to 2013 (see the Perspective by D'Souza). Although the observed cascades were widespread, a small fraction of all network components, particularly the ones that were most cohesive within the network, were vulnerable to cascading failures. Larger cascades were associated with concurrent triggering events that were geographically closer to each other and closer to the set of vulnerable components.

Science
, this issue p.
eaan3184
; see also p.
860
The structural basis of flagellin detection by NAIP5: A strategy to limit pathogen immune evasion
Authors: Tenthorey Jeannette L. , Haloupek Nicole , López-Blanco José Ramón , Grob Patricia , Adamson Elise , Hartenian Ella , Lind Nicholas A. , Bourgeois Natasha M. , Chacón Pablo , Nogales Eva , Vance Russell E.
Published: November 2017

Another spin at the wheel

The NLR (nucleotide-binding domain leucine-rich repeat) proteins are a key intracellular component of the early innate immune response to pathogens. After binding microbial ligands, assorted NLR family members assemble to form enormous signaling complexes (inflammasomes), which promote pro-inflammatory cytokine secretion and cell death. Tenthorey
et al.
used cryo-electron microscopy to visualize an assembled ligand-bound inflammasome. They find that when NAIP5 binds flagellin, it changes conformation, which triggers a rotation in monomeric NLRC4, catalyzing further NLRC4 recruitment. Steric clash results in a partially open structure, in contrast with previous descriptions of a closed symmetrical “wheel.” Furthermore, NAIP5 recognizes multiple regions of its ligand, and mutations of flagellin that allow for NAIP5 evasion compromise bacterial fitness.

Science
, this issue p.
888
Compacted dimensions and singular plasmonic surfaces
Authors: Pendry J. B. , Huidobro Paloma Arroyo , Luo Yu , Galiffi Emanuele
Published: November 2017

How to hide a dimension from view

Compacted dimensions are essential ingredients of advanced string theories; the extra dimensions used to describe the world are hidden from view, or compacted. Pendry
et al.
used concepts of transformation optics, in which metamaterials are designed to produce specific optical properties, to show theoretically that compacted dimensions could be possible in plasmonic structures. For example, simulations with a metallic grating and periodically doped graphene revealed that two-dimensional structures exhibit optical properties of a bulk material. To all intents and purposes, it looks as if one of the dimensions is compacted. The results could have practical application in designing broadband optical absorbers.

Science
, this issue p.
915
Advancing dengue vaccine development
Authors: Feinberg Mark B. , Ahmed Rafi
Published: November 2017

Insights into the natural history of dengue virus infection guide vaccine development
Curtailing cascading failures
Authors: D'Souza Raissa M.
Published: November 2017

The failure of a small but variable set of links can bring down a supply network
Feeding frenzy for cancer cells
Authors: Dang Chi V.
Published: November 2017

Cancer cells rewire metabolism to scavenge nutrients and waste products
Sensitivity analysis for mistakenly adjusting for mediators in estimating total effect in observational studies
Authors: Wang Tingting , Li Hongkai , Su Ping , Yu Yuanyuan , Sun Xiaoru , Liu Yi , Yuan Zhongshang , Xue Fuzhong
Published: November 2017

Objectives

In observational studies, epidemiologists often attempt to estimate the total effect of an exposure on an outcome of interest. However, when the underlying diagram is unknown and limited knowledge is available, dissecting bias performances is essential to estimating the total effect of an exposure on an outcome when mistakenly adjusting for mediators under logistic regression. Through simulation, we focused on six causal diagrams concerning different roles of mediators. Sensitivity analysis was conducted to assess the bias performances of varying across exposure-mediator effects and mediator-outcome effects when adjusting for the mediator.

Setting

Based on the causal relationships in the real world, we compared the biases of varying across the effects of exposure-mediator with those of varying across the effects of mediator-outcome when adjusting for the mediator. The magnitude of the bias was defined by the difference between the estimated effect (using logistic regression) and the total effect of the exposure on the outcome.

Results

In four scenarios (a single mediator, two series mediators, two independent parallel mediators or two correlated parallel mediators), the biases of varying across the effects of exposure-mediator were greater than those of varying across the effects of mediator-outcome when adjusting for the mediator. In contrast, in two other scenarios (a single mediator or two independent parallel mediators in the presence of unobserved confounders), the biases of varying across the effects of exposure-mediator were less than those of varying across the effects of mediator-outcome when adjusting for the mediator.

Conclusions

The biases were more sensitive to the variation of effects of exposure-mediator than the effects of mediator-outcome when adjusting for the mediator in the absence of unobserved confounders, while the biases were more sensitive to the variation of effects of mediator-outcome than those of exposure-mediator in the presence of an unobserved confounder.
Relationship between socioeconomic status and HIV infection: findings from a survey in the Free State and Western Cape Provinces of South Africa
Authors: Bunyasi Erick Wekesa , Coetzee David John
Published: November 2017

Background

Studies have shown a mixed association between socioeconomic status (SES) and prevalent HIV infection across and within settings in sub-Saharan Africa. In general, the relationship between years of formal education and HIV infection changed from a positive to a negative association with maturity of the HIV epidemic. Our objective was to determine the association between SES and HIV in women of reproductive age in the Free State (FSP) and Western Cape Provinces (WCP) of South Africa (SA).

Study design

Cross-sectional.

Setting

SA.

Methods

We conducted secondary analysis on 1906 women of reproductive age from a 2007 to 2008 survey that evaluated effectiveness of Prevention of Mother-to-Child HIV Transmission Programmes. SES was measured by household wealth quintiles, years of formal education and employment status. Our analysis principally used logistic regression for survey data.

Results

There was a significant negative trend between prevalent HIV infection and wealth quintile in WCP (P<0.001) and FSP (P=0.025). In adjusted analysis, every additional year of formal education was associated with a 10% (adjusted OR (aOR) 0.90 (95% CI 0.85 to 0.96)) significant reduction in risk of prevalent HIV infection in WCP but no significant association was observed in FSP (aOR 0.99; 95% CI 0.89 to 1.11). There was no significant association between employment and prevalent HIV in each province: (aOR 1.54; 95% CI 0.84 to 2.84) in WCP and (aOR 0.96; 95% CI 0.71 to 1.30) in FSP.

Conclusion

The association between HIV infection and SES differed by province and by measure of SES and underscores the disproportionately higher burden of prevalent HIV infection among poorer and lowly educated women. Our findings suggest the need for re-evaluation of whether current HIV prevention efforts meet needs of the least educated (in WCP) and the poorest women (both WCP and FSP), and point to the need to investigate additional or tailored strategies for these women.
Access to healthcare for men and women with disabilities in the UK: secondary analysis of cross-sectional data
Authors: Sakellariou Dikaios , Rotarou Elena S
Published: November 2017

Objectives

The aim of this study was to investigate differences in access to healthcare between people with and without disabilities in the UK. The hypotheses were that: (1) people with disabilities would be more likely to have unmet healthcare needs and (2) there would be gender differences, with women more likely to report unmet needs.

Setting and participants

We performed secondary analysis, using logistic regressions, of deidentified cross-sectional data from the European Health Interview Survey, Wave 2. The sample included 12 840 community-dwelling people over the age of 16 from across the UK, 5 236 of whom had a disability. The survey method involved face-to-face and telephone interviews.

Outcome measures

Unmet need for healthcare due to long waiting lists or distance or transportation problems; not being able to afford medical examination, treatment, mental healthcare or prescribed medicines. All measures were self-reported.

Results

Adjusting for age, sex and other factors, people with a severe disability had higher odds of facing unmet needs. The largest gap was in ‘unmet need for mental healthcare due to cost’, where people with a severe disability were 4.5 times (CI 95% 2.2 to 9.2) more likely to face a problem, as well as in ‘unmet need due to cost of prescribed medicine’, where people with a mild disability had 3.6 (CI 95% 2.2 to 5.9) higher odds of facing a difficulty. Women with a disability were 7.2 times (CI 95% 2.7 to 19.4) more likely to have unmet needs due to cost of care or medication, compared with men with no disability.

Conclusions

People with disabilities reported worse access to healthcare, with transportation, cost and long waiting lists being the main barriers. These findings are worrying as they illustrate that a section of the population, who may have higher healthcare needs, faces increased barriers in accessing services.
A randomised controlled trial of an online menu planning intervention to improve childcare service adherence to dietary guidelines: a study protocol
Authors: Yoong Sze Lin , Grady Alice , Wiggers John , Flood Victoria , Rissel Chris , Finch Meghan , Searles Andrew , Salajan David , O’Rourke Ruby , Daly Jaqueline , Gilham Karen , Stacey Fiona , Fielding Alison , Pond Nicole , Wyse Rebecca , Seward Kirsty , Wolfenden Luke
Published: November 2017

Introduction

The implementation of dietary guidelines in childcare settings is recommended to improve child public health nutrition. However, foods provided in childcare services are not consistent with guidelines. The primary aim of the trial is to assess the effectiveness of a web-based menu planning intervention in increasing the mean number of food groups on childcare service menus that comply with dietary guidelines regarding food provision to children in care.

Methods and analysis

A parallel group randomised controlled trial will be undertaken with 54 childcare services that provide food to children within New South Wales, Australia. Services will be randomised to a 12-month intervention or usual care. The experimental group will receive access to a web-based menu planning and decision support tool and online resources. To support uptake of the web program, services will be provided with training and follow-up support. The primary outcome will be the number of food groups, out of 6 (vegetables, fruit, breads and cereals, meat, dairy and ‘discretionary’), on the menu that meet dietary guidelines (Caring for Children) across a 1-week menu at 12-month follow-up, assessed via menu review by dietitians or nutritionists blinded to group allocation. A nested evaluation of child dietary intake in care and child body mass index will be undertaken in up to 35 randomly selected childcare services and up to 420 children aged approximately 3–6 years.

Ethics and dissemination

Ethical approval has been provided by Hunter New England and University of Newcastle Human Research Ethics Committees. This research will provide high-quality evidence regarding the impact of a web-based menu planning intervention in facilitating the translation of dietary guidelines into childcare services. Trial findings will be disseminated widely through national and international peer-reviewed publications and conference presentations.

Trial registration

Prospectively registered with Australian New Zealand Clinical Trial Registry (ANZCTR) ACTRN12616000974404.
Functional visual fields: a cross-sectional UK study to determine which visual field paradigms best reflect difficulty with mobility function
Authors: Subhi Hikmat , Latham Keziah , Myint Joy , Crossland Michael
Published: November 2017

Objectives

To develop an appropriate method of assessing visual field (VF) loss which reflects its functional consequences, this study aims to determine which method(s) of assessing VF best reflect mobility difficulty.

Setting

This cross-sectional observational study took place within a single primary care setting. Participants attended a single session at a University Eye Clinic, Cambridge, UK, with data collected by a single researcher (HS), a qualified optometrist.

Participants

50 adult participants with peripheral field impairment were recruited for this study. Individuals with conditions not primarily affecting peripheral visual function, such as macular degeneration, were excluded from the study.

Primary and secondary outcome measures

Participants undertook three custom and one standard binocular VF tests assessing VF to 60°, and also integrated monocular threshold 24–2 visual fields (IVF). Primary VF outcomes were average mean threshold, percentage of stimuli seen and VF area. VF outcomes were compared with self-reported mobility function assessed with the Independent Mobility Questionnaire, and time taken and patient acceptability were also considered. Receiver operating characteristic (ROC) curves determined which tests best predicted difficulty with mobility tasks.

Results

Greater VF loss was associated with greater self-reported mobility difficulty with all field paradigms (R20.38–0.48, all P<0.001). All four binocular tests were better than the IVF at predicting difficulty with at least three mobility tasks in ROC analysis. Mean duration of the tests ranged from 1 min 26 s (±9 s) for kinetic assessment to 9 min 23 s (±24 s) for IVF.

Conclusions

The binocular VF tests extending to 60° eccentricity all relate similarly to self-reported mobility function, and slightly better than integrated monocular VFs. A kinetic assessment of VF area is quicker than and as effective at predicting mobility function as static threshold assessment.
Cohort profile: the Mayo Clinic Cohort Study of Oophorectomy and Aging-2 (MOA-2) in Olmsted County, Minnesota (USA)
Authors: Rocca Walter A , Gazzuola Rocca Liliana , Smith Carin Y , Grossardt Brandon R , Faubion Stephanie S , Shuster Lynne T , Stewart Elizabeth A , Mielke Michelle M , Kantarci Kejal , Miller Virginia M
Published: November 2017

Purpose

This cohort study was established to investigate the effects of unilateral and bilateral oophorectomy on the ageing processes in women.

Participants

We used the records-linkage system of the Rochester Epidemiology Project (REP,http://www.rochesterproject.org) to identify 570 women who underwent unilateral oophorectomy and 1653 women who underwent bilateral oophorectomy in Olmsted County, Minnesota from 1988 through 2007 (20 years). Each woman was matched by age (±1 year) to a population-based referent woman who had not undergone any oophorectomy (570 referent women) or bilateral oophorectomy (1653 referent women). These four cohorts are being followed to assess morbidity and mortality and to study imaging and biological markers related to ageing.

Findings to date

An extensive medical record abstraction using the REP has been completed for each woman to obtain demographic, reproductive and adult life characteristics and extensive clinical information about the surgical procedure and subsequent oestrogen replacement therapy (or other sex steroid therapy). The cohorts have been used to date to study the accumulation of multiple chronic conditions following bilateral oophorectomy in women with or without chronic conditions at the time of the oophorectomy (or index date). From the cohorts, we have also derived a sample of 128 pairs of women for a case–control study linking adverse childhood or adult experiences to the risk of bilateral oophorectomy.

Future plans

We hypothesise that the abrupt hormonal changes caused by bilateral oophorectomy in younger women have a major effect on the ageing processes across the full body. Therefore, we plan to investigate the risk of a wide range of chronic conditions following bilateral oophorectomy. Specific studies are underway for kidney diseases, psychiatric diseases and neurological diseases. In addition, we plan to invite a subsample of women from the bilateral oophorectomy cohort to participate in an in-person study involving brain imaging and the collection of biomarkers.
ON THE EFFECT OF IMPERFECT COLLUSION ON PROFITABILITY AND R&D
Authors: ESCRIHUELA-VILLAR MARC , GUILLÉN JORGE
Published: November 2017

We consider a theoretical model where firms can reduce their initial unit costs by spending on R&D. We show that the degree of product market collusion (captured by the coefficient of cooperation) might reduce firms’ profits if innovation is made non-cooperatively. The intuition is that non-cooperative R&D introduces a negative externality where firms invest over and above the amount required to minimize costs so as to extract profits from their rival firm. Therefore, when product market competition drops below a certain level, a relatively large amount is spent on R&D with just a small output, making further collusion unprofitable. On the contrary, a Research Joint Venture (RJV) helps to internalize the externality and further product market collusion always increases firms’ profits. As a consequence, total welfare may be lower if R&D is made cooperatively.
One-loop radiative seesaw dark matter and neutrinoless double beta decay with two zero flavor neutrino mass texture
Authors: Kitabayashi Teruyuki , Ohkawa Shinya , Yasuè Masaki
Published: November 2017

We discuss the linkage between dark matter mass in the one-loop radiative seesaw model and the effective neutrino mass for the neutrinoless double beta decay. This linkage, which has been already numerically suggested, is confirmed to be a reasonable relationship by deriving analytical expressions for two zero flavor neutrino mass texture.
On quantum-mechanical equations of motion in representation dependent of external sources
Authors: Batalin Igor A. , Lavrov Peter M.
Published: November 2017

In the present paper, we consider in detail the aspects of the Heisenberg’s equations of motion, related to their transformation to the representation dependent of external sources. We provide with a closed solution as to the variation-derivative motion equations in the general case of a normal form (symbol) chosen. We show that the action in the path integral does depend actually on a particular choice of a normal symbol. We have determined both the aspects of the latter dependence: the specific boundary conditions for virtual trajectories, and the specific boundary terms in the action.
XUV pulse effect on harmonic emission spectra and attosecond pulse generation
Authors: Feng Liqiang , Castle R. S. , Li Yi
Published: November 2017

The generation of the high-order harmonic and the attosecond pulse from He atom driven by the near-infrared (NIR) field combined with the XUV pulse has been theoretically investigated by solving the three-dimensional time-dependent Schrödinger equation. The results show that by properly adding the XUV pulse into the NIR field, (i) not only the harmonic yield is enhanced, caused by the laser-induced excited state effect; but also the multi-cutoff extension of the harmonics can be found, caused by the absorption of the extra XUV photons during its recombination process. (ii) With the introduction of the XUV pulse, the frequency modulation of the high-order harmonic generation (HHG) can be found and controlled. (iii) By directly superposing the harmonics in the cutoff region, two isolated XUV pulses with the durations of 150 as can be obtained.
Optimal selection of photo-ionization and electric field ionization
Authors: Qi Xiao-Qiu , Dai Chang-Jian , Zhong Zhen-Xiang
Published: November 2017

In this paper, the dynamic characteristics of the two approaches of atomic ionization, photo-excitation plus photo-ionization (PE+PI) and the photo-excitation plus electric field ionization (PE+EFI) are investigated systematically. For the PE+PI process, two different schemes (I and II), with and without overlapping pulse duration, are designed and specified. The rate equations for both PE+PI and PE+EFI processes are established, numerical solutions of which provide profound characteristics. A detailed analysis of the theoretical results is carried out to observe the impacts on their overall ionization efficiency made by several factors, either atomic or laser parameters. Not only the ionization efficiency of both approaches is given, but also the optimal selection under some specific conditions is discussed. If the pulse widths of lasers are fixed, then the PE+EFI approach is superior to the PE+PI approach when laser powers are small, while the PE+PI approach is better otherwise.
Stability and Bifurcation Analysis in a Predator–Prey System with Constant Harvesting and Prey Group Defense
Authors: Luo Jianfeng , Zhao Yi
Published: November 2017

In this paper, we study a predator–prey system that the prey population gathers in herds to defend its predator and both are harvested by constant rate. The defensive strategy of the gathered prey makes the individuals at the border of the herd mostly suffer from the attacks of the predators. This behavior can be described by a modified Holling-type II functional response in mathematics. Notably, we consider harvesting under two cases: prey harvesting only and predator harvesting only. We investigate the existence of equilibria for both cases, and then find there exists the maximum sustainable yield for two cases to guarantee predator and prey to coexist. Moreover, both species can coexist under some conditions and initial values through investigation of stability of the interior equilibrium in the given system. These results demonstrate that, when hunting the prey or predator for economic interest, harvesting rate must be chosen at a suitable value (not merely less than the maximum sustainable yield) to maintain the coexistence of the predator and prey as well as ecological balance. Finally, we analyze the saddle-node bifurcation and Hopf bifurcation, and determine the direction of Hopf bifurcation by calculating the first Lyapunov number for both cases. In particular, Bogdanov–Takens bifurcation occurs only in the given system with predator harvesting.
No positive cone in a free product is regular
Authors: Hermiller Susan , Šunić Zoran
Published: November 2017

We show that there exists no left order on the free product of two nontrivial, finitely generated, left-orderable groups such that the corresponding positive cone is represented by a regular language. Since there are orders on free groups of rank at least two with positive cone languages that are context-free (in fact, 1-counter languages), our result provides a bound on the language complexity of positive cones in free products that is the best possible within the Chomsky hierarchy. It also provides a strengthening of a result by Cristóbal Rivas which states that the positive cone in a free product of nontrivial, finitely generated, left-orderable groups cannot be finitely generated as a semigroup. As another illustration of our method, we show that the language of all geodesics (with respect to the natural generating set) that represent positive elements in a graph product of groups defined by a graph of diameter at least 3 cannot be regular.
Noncanonical two-field inflation to order ξ2
Authors: Wang Yun-Chao , Wang Towe
Published: November 2017

In noncanonical two-field inflation models, deviations from the canonical model can be captured by a parameter [Formula: see text]. We show this parameter is usually one half of the slow-roll order and analytically calculate the primordial power spectra accurate to order [Formula: see text]. The super-horizon perturbations are studied with an improved method, which gives a correction of order [Formula: see text]. Three typical examples demonstrate that our analytical formulae of power spectra fit well with numerical simulation.
Historical perspective and future prospects for nuclear interactions
Authors: Machleidt R.
Published: November 2017

The nuclear force is the heart of nuclear physics and, thus, the significance of this force for all of nuclear physics can hardly be overstated. Research on this crucial force has by now spanned eight decades and we are still not done. I will first review the rich history of hope and desperation, which had spin-off far beyond just nuclear physics. Next, I will present the current status in the field which is characterized by the application of an effective field theory (EFT) that is believed to represent QCD in the low energy regime typical for nuclear physics. During the past two decades, this EFT has become the favorite vehicle to derive nuclear two- and many-body forces. Finally, I will take a look into the future: What developments can we expect from the next decades? Will the 30-year cycles of new and “better” ideas for efficiently describing nuclear forces go on for ever, or is there hope for closure?
STUDY ON THE PERMEABILITY OF RED SANDSTONE VIA IMAGE ENHANCEMENT
Authors: ZHU QINGYONG , YANG WEIBIN , YU HUAIZHONG
Published: November 2017

Scanning electron microscopy (SEM) is of great importance for studying fractal permeability. In this work, we presented a new technique, by applying the high-order upwind compact difference schemes to solve the hyperbolic conservation laws, to enhance textural differences for accurate segmentation of the SEM images. From the enhanced SEM images, the channels and pores can be obtained by using the two-stage image segmentation. Combining with the box counting method, the key parameters for evaluation of the fractal permeability such as the tortuosity fractal dimension, the pore area fractal dimension and the maximum pore area can be derived from the segmented images. Application of the technique to the SEM images of a red sandstone from south China shows remarkable enhancement of edge details, allowing the more accurate segmentation of the SEM images. Rather than the original image algorithm, the fractal permeability derived from this new approach is closer to the experimental value, especially when the magnification falls in the range of 500–600. The results evidence that our enhanced images approach may provide stronger constraints on evaluations of permeability of sandstones.
ESTIMATION OF THE FRACTAL DIMENSION OF WEIERSTRASS–MANDELBROT FUNCTION BASED ON CUCKOO SEARCH METHODS
Authors: DONG JIABIN , JU YANG , GAO FENG , XIE HEPING
Published: November 2017

The Weierstrass–Mandelbrot randomized function (WMRF) has been widely applied to characterize rough surface profiles with a specified fractal dimension ([Formula: see text]). However, it is difficult to accurately determine the specified [Formula: see text] for the WMRF. In this study, we proposed a novel approach to determine the [Formula: see text]. First, the cuckoo search (CS) algorithm is adopted as an optimization algorithm to extract the trend line of a rough profile instead of a traditional measurement method that measures profiles with a fixed length or a designed lag distance. Then, the total vertical distance ([Formula: see text]) of all the points on a profile to its optimal trend line that is extracted by the CS measurement method is calculated. Finally, it is found that the absolute exponent value of the power law relationship between [Formula: see text] and the number of steps ([Formula: see text]) has a linear relationship to [Formula: see text], and thus, in turn, provides a method to estimate the value of fractal dimension for WMRF by providing more details about the original profile simultaneously. The CS measurement method furnishes a better method for extracting the trend polyline with variable-step lengths and for characterizing the roughness of a rough profile directly as well.
Chronic maternal hypercortisolemia in late gestation alters fetal cardiac function at birth
Authors: Antolic Andrew , Wood Charles E. , Keller-Wood Maureen
Published: November 2017

Studies in our laboratory have shown that modest chronic increases in maternal cortisol concentrations over the last 0.20 of gestation impair maternal glucose metabolism and increase the incidence of perinatal stillbirth. Previous studies had found that an increase in maternal cortisol concentrations from 115 to 130 days of gestation in sheep increased both proliferation in fetal cardiomyocytes and apoptosis in the fetal cardiac Purkinje fibers. We hypothesized that the adverse effects of excess cortisol may result in defects in cardiac conduction during labor and delivery. In the present study, we infused cortisol (1 mg·kg−1·day−1) into late gestation pregnant ewes and continuously monitored fetal aortic pressure and ECG through labor and delivery. We found that, although the fetuses of cortisol infused ewes had normal late gestation patterns of arterial pressure and heart rate, there was a significant decrease in fetal aortic pressure and heart rate on the day of birth, specifically in the final hour before delivery. Significant changes in the fetal ECG were also apparent on the day of birth, including prolongation of the P wave and P-R interval. We speculate that chronic exposure to glucocorticoids alters cardiac metabolism or ion homeostasis, contributing to cardiac dysfunction, precipitated by active labor and delivery.
Tonic aortic depressor nerve stimulation does not impede baroreflex dynamic characteristics concomitantly mediated by the stimulated nerve
Authors: Kawada Toru , Turner Michael J. , Shimizu Shuji , Kamiya Atsunori , Shishido Toshiaki , Sugimachi Masaru
Published: November 2017

Although electrical activation of the carotid sinus baroreflex (baroreflex activation therapy) is being explored as a device therapy for resistant hypertension, possible effects on baroreflex dynamic characteristics of interaction between electrical stimulation and pressure inputs are not fully elucidated. To examine whether the electrical stimulation of the baroreceptor afferent nerve impedes normal short-term arterial pressure (AP) regulation mediated by the stimulated nerve, we electrically stimulated the right aortic depressor nerve (ADN) while estimating the baroreflex dynamic characteristics by imposing pressure inputs to the isolated baroreceptor region of the right ADN in nine anesthetized rats. A Gaussian white noise signal with a mean of 120 mmHg and standard deviation of 20 mmHg was used for the pressure perturbation. A tonic ADN stimulation (2 or 5 Hz, 10 V, 0.1-ms pulse width) decreased mean sympathetic nerve activity (367.0 ± 70.9 vs. 247.3 ± 47.2 arbitrary units, P < 0.01) and mean AP (98.4 ± 7.8 vs. 89.2 ± 4.5 mmHg, P < 0.01) during dynamic pressure perturbation. The ADN stimulation did not affect the slope of dynamic gain in the neural arc transfer function from pressure perturbation to sympathetic nerve activity (16.9 ± 1.0 vs. 14.7 ± 1.6 dB/decade, not significant). These results indicate that electrical stimulation of the baroreceptor afferent nerve does not significantly impede the dynamic characteristics of the arterial baroreflex concomitantly mediated by the stimulated nerve. Short-term AP regulation by the arterial baroreflex may be preserved during the baroreflex activation therapy.
Buffer Film Assisted Growth of Dense MWCNTs on Copper Foils for Flexible Electrochemical Applications
Authors: Pakdee Udomdej , Duangsawat Boonchai
Published: November 2017

The novel Inconel buffer films were prepared on copper foils using unbalance direct current (DC) magnetron sputtering. These films were employed as buffer layers for supporting the dense growth of multiwalled carbon nanotubes (MWCNTs). Thermal chemical vapor deposition (CVD) with metal alloys such as stainless steel (SS) type 304 films was considered to synthesize MWCNTs. To understand the effectiveness of these buffer films, the MWCNTs grown on buffer-free layer were carried out as a comparison. The main problem such as the diffusion of catalysts into the oxide layer of metal substrate during the CVD process was solved together with a creation of good electrical contact between substrate and nanotubes. The morphologies, crystallinities, and electrochemical behaviors of MWCNTs grown on Inconel buffer films with 304 SS catalysts revealed the better results for applying in flexible electrochemical applications.
Respiratory Tract Viral Infections and Coinfections Identified by Anyplex™ II RV16 Detection Kit in Pediatric Patients at a Riyadh Tertiary Care Hospital
Authors: Eifan Saleh A. , Hanif Atif , AlJohani Sameera Mohammed , Atif Muhammad
Published: November 2017

Respiratory infections are caused by an array of viruses, and limited information is available about viral coexistence, comparative symptoms, and the burden of illness. This retrospective cohort study aimed to determine the etiological agents responsible for respiratory tract infections by Anyplex II RV16 detection kit (RV16, Seegene), involving 2266 pediatric patients with respiratory infections admitted to the Department of Pediatrics at King Abdul-Aziz Medical City, Ministry of National Guard, Riyadh, from July 2014 to June 2015. The most frequent respiratory infections were recorded in the 1 to 5 year age group (44.7%). Rhinovirus (32.5%), Adenovirus (16.9%), and Respiratory syncytial virus (RSV) B (10.4%) were most common. In single viral infections, Rhinovirus (41.2%), Metapneumovirus (15.3%), and Bocavirus (13.7%) were most frequent. In multiple viral infections, Rhinovirus (36.7%), Adenovirus (35.2%), Bocavirus (11.2), RSV B (7.8%), and RSV A (6.7%) were most frequent. No significant difference was observed in clinical presentations; however, rhinorrhea and hypodynamia were significantly associated with viral respiratory infections. Most respiratory viral pathogens peaked during December, January, March, and April. Rhinovirus, Adenovirus, and Bocavirus circulations were detected throughout the year. Winter peaks were recorded for Rhinovirus, RSV B, Adenovirus, and RSV A, whereas the Metapneumovirus, and the Bocavirus peaked in March and April. These findings enhance understanding of viral etiology and distribution to improve respiratory infection management and treatment.
Evaluation of Factors Affecting E-Bike Involved Crash and E-Bike License Plate Use in China Using a Bivariate Probit Model
Authors: Guo Yanyong , Zhou Jibiao , Wu Yao , Chen Jingxu
Published: November 2017

The primary objective of this study is to evaluate factors affecting e-bike involved crash and license plate use in China. E-bike crashes data were collected from police database and completed through a telephone interview. Noncrash samples were collected by a questionnaire survey. A bivariate probit (BP) model was developed to simultaneously examine the significant factors associated with e-bike involved crash and e-bike license plate and to account for the correlations between them. Marginal effects for contributory factors were calculated to quantify their impacts on the outcomes. The results show that several contributory factors, including gender, age, education level, driver license, car in household, experiences in using e-bike, law compliance, and aggressive driving behaviors, are found to have significant impacts on both e-bike involved crash and license plate use. Moreover, type of e-bike, frequency of using e-bike, impulse behavior, degree of riding experience, and risk perception scale are found to be associated with e-bike involved crash. It is also found that e-bike involved crash and e-bike license plate use are strongly correlated and are negative in direction. The result enhanced our comprehension of the factors related to e-bike involved crash and e-bike license plate use.
Upregulations of Clcn3 and P-Gp Provoked by Lens Osmotic Expansion in Rat Galactosemic Cataract
Authors: Ji Lixia , Cheng Lixia , Yang Zhihong
Published: November 2017

Objective.Lens osmotic expansion, provoked by overactivated aldose reductase (AR), is the most essential event of sugar cataract. Chloride channel 3 (Clcn3) is a volume-sensitive channel, mainly participating in the regulation of cell fundamental volume, and P-glycoprotein (P-gp) acts as its modulator. We aim to study whether P-gp and Clcn3 are involved in lens osmotic expansion of galactosemic cataract.Methods and Results.In vitro, lens epithelial cells (LECs) were primarily cultured in gradient galactose medium (10–60 mM), more and more vacuoles appeared in LEC cytoplasm, and mRNA and protein levels of AR, P-gp, and Clcn3 were synchronously upregulated along with the increase of galactose concentration. In vivo, we focused on the early stage of rat galactosemic cataract, amount of vacuoles arose from equatorial area and scattered to the whole anterior capsule of lenses from the 3rd day to the 9th day, and mRNA and protein levels of P-gp and Clcn3 reached the peak around the 9th or 12th day.Conclusion. Galactosemia caused the osmotic stress in lenses; it also markedly leads to the upregulations of AR, P-gp, and Clcn3 in LECs, together resulting in obvious osmotic expansion in vitro and in vivo.
Some Hermite-Hadamard-Fejér Type Integral Inequalities for Differentiable η-Convex Functions with Applications
Authors: Rostamian Delavar M. , De La Sen M.
Published: November 2017

Using some results about generalized Hermite-Hadamard-Fejér type inequalities related to η-convex functions, we give some examples and applications for trapezoid and midpoint type inequalities for differentiable η-convex functions.
Microcystins Presence in Mussels(M. galloprovincialis)and Water of Two Productive Mediterranean’s Lagoons (Sardinia, Italy)
Authors: Baralla Elena , Varoni Maria Vittoria , Sedda Tiziana , Pasciu Valeria , Floris Antonello , Demontis Maria Piera
Published: November 2017

Microcystins (MCs) are hepatotoxins harmful for animal and human health. The most toxic type between them is MC-LR whose presence has been investigated in different reservoirs all around the world. In this work microcystins were monitored in spring and summer in water and mussels(Mytilus galloprovincialis)of two Sardinia lagoons: Cabras and Calich lagoons. A Solid Phase Extraction method was developed to clean and concentrate samples before the Enzyme Linked Immunosorbent Assay (ELISA) and the following Mass Spectrometry detection. MCs presence was detected using the screening ELISA test in both lagoons. MCs peak was revealed in July for water and mussels belonging to Cabras lagoon (0.75±0.07 ng/L in water and0.12±0.04 ng/g ww in mussels). In water of Calich lagoon there was a constant trend in the concentration of MCs during the considered months, while there was a MCs peak in July (0.6±0.5 ng/g ww) in mussels. The following LC-MS/MS analysis did not reveal MC-LR presence in all analyzed samples. These results can be useful to enrich knowledge on public health and consumer’s safeguard.
A New 3D Autonomous Continuous System with Two Isolated Chaotic Attractors and Its Topological Horseshoes
Authors: Zhou Ping , Ke Meihua
Published: November 2017

Based on the 3D autonomous continuous Lü chaotic system, a new 3D autonomous continuous chaotic system is proposed in this paper, and there are coexisting chaotic attractors in the 3D autonomous continuous chaotic system. Moreover, there are no overlaps between the coexisting chaotic attractors; that is, there are two isolated chaotic attractors (in this paper, named “positive attractor” and “negative attractor,” resp.). The “positive attractor” and “negative attractor” depend on the distance between the initial points (initial conditions) and the unstable equilibrium points. Furthermore, by means of topological horseshoes theory and numerical computation, the topological horseshoes in this 3D autonomous continuous system is found, and the topological entropy is obtained. These results indicate that the chaotic attractor emerges in the new 3D autonomous continuous system.