bluuebunny/crossref_metadata_2025 huggingface dataset:
An Investigation on the Students’ Opinions of Bilingual Teaching in Universities of Western China
Authors: Yuqian Yang
Published: September 2018

In the western areas of China, bilingual teaching is in the beginning phrase, and hasn’t reached the desirable outcomes. In order to know the development phase of bilingual teaching in less-developed areas of China, this paper chose students and teachers from two universities which respectively located in two provinces of the western areas of China and have different teaching levels as representative examples, and issued total of 352 valid questionnaires to reflect the bilingual teaching comprehensively. The research finds that learners have pessimistic attitude toward bilingual teaching and don’t realize that the great importance of bilingual teaching in terms of personal development in the long run. The efficiency of bilingual teaching is affected by multitude of factors, including students’ attitudes and learning methods, learning situation in and after class, teacher’s levels, assessment methods and students’ understanding levels. The thesis also investigates the evaluation systems of bilingual teaching and finds that students prefer the combination of oral and written exam.
Exercise Addiction: A Comparison Between the Individuals Who Exercise for Physical Recreation and Who Receive Personal Exercise Training
Authors: Basoglu Umut Davut
Published: September 2018

In the study, we aim to investigate the exercise addiction levels of the individuals who join sports centers for recreational activity and the ones who also receive personal exercise training. The universe of this study is the individuals who are members of The Club sports center located in Istanbul province, the European side of Esenyurt. The sample is composed of 120 members who are selected by the simple random sampling. The participants are all the members of the sports center who have regularly exercised for at least one year and continue to sports center at least two days a week. Participants have received enlightened approvals for voluntary participation either.In order to measure exercise addiction level, we used "Exercise Addiction Scale-21" developed by Hausenblas and Downs (2002) and adapted to Turkish by Yeltep and İkizler (2007).Frequency test is used to reveal the features of the participants. The data were not normally distributed. So Kruskal-Wallis and Mann Whitney U Tests were used for cross-group comparisons. Findings were accepted as statistically significant at p <0.05 level.Results show that exercise addiction levels of individuals who have received special training and those who spend more time on monthly and weekly exercise are higher than the rest.As a conclusion, the increase in the number of days and the number of hours of exercises seems to be an antecedent, of exercise addiction. We also find out that the exercise addiction levels of individuals who receive personal exercise training are higher.
The Impact of Out-of-School Learning Environments on 6th Grade Secondary School Students Attitude Towards Science Course
Authors: Yildirim Halil Ibrahim
Published: September 2018

This study was conducted for the purpose of determining the impacts of out-of-school learning environments on 6th-grade students’ attitudes towards science course. In the study, the quasi-experimental model and pretest-posttest control grouped experimental design was employed. The experimental process step of the study was carried out on 6th-grade students who receive education in a secondary school in Turkey in 2017 and maintained for 18 weeks. 60 students are included in the study group of the research (control group=30, experimental group=30). For the purpose of measuring the attitude scores towards science course, “The Scale of Attitude towards Science Lesson” was used. The experimental phase was performed by science lesson teacher both in the control and experimental groups. No experimental process was applied in the control group. The instruction was provided in accordance with the Science Course Curriculum. While the instruction was provided in line with the control group in the experimental group, out-of-school learning environments were also included in the teaching process. Out-of-school learning environments were specified by considering the learning outcomes in the 6th-grade science curricula. Experimental group students visited out-of-school learning environments with the guidance of the science teacher. Science museum, anatomy museum, planetarium, nature trip, science festivals, energy park and aqua park are among the out-of-school learning environments. As a result of the study, it was seen that the attitudes of the students in the experimental group were increased at a significant level, and no significant improvement was realized in control group students’ attitudes.
Normal stress in magnetorheological polymer gel under large amplitude oscillatory shear
Authors: Pang Haoming , Pei Lei , Sun Chuanlin , Gong Xinglong
Published: September 2018

In this study, the normal stress in magnetorheological polymer gel (MRPG) under large amplitude oscillatory shear was investigated using experiments and particle-level simulations. Under large amplitude oscillatory shear, an intensely oscillating normal stress was measured with a period of exactly half the strain period. As the amplitude of the strain increased, the peak of the normal stress increased and the trough decreased. Changes in the normal stress were mainly caused by two factors: the Poynting effect, in which shear produces a normal force perpendicular to the shear direction, and magnetic-induced normal stress, which changes with the particle structure. In MRPG, both effects are related to the particle structure. The particle structure in MRPG with different strain was calculated and the simulation results show that the amplitude of the structural strain in oscillatory shearing is less than that of the applied strain. Additionally, a phase difference was observed between the structural strain and the applied strain. Based on the calculated particle structure, the change in the normal stress was obtained and found to agree well with the experimental results.
Flow-rate based method for velocity of fully developed laminar flow in tubes
Authors: Kim Sun Kyoung
Published: September 2018

This work proposes an explicit method to determine velocity profiles of non-Newtonian fluids flowing in the laminar fully developed regime through a straight tube with a circular cross section. An integral expression for local velocity is derived by introducing the concept of a core-flow rate at a point in the tube as the rate of the partial flow passing through a coaxially centered circular cross section with a radius equal to the radial position of that point. In this approach, the velocity is expressed as the difference between the mean core velocity from the core-flow rate and the mean velocity of the flow through a virtual tube with its wall at the corresponding radial position. First, this method has been verified using velocities for the Newtonian and power law models. Then, it has been applied to velocity calculations for fluids obeying the Carreau, Cross, and Phan–Thien–Tanner (PTT) models. Moreover, the velocity result for the Carreau model has been applied to the viscosity reconstruction by the inverse parameter estimation from the measured velocity. Specifically, for the PTT model case, the slip boundary condition has also been considered. The mean velocity of the virtual tube flow can be determined by the difference between the measured and the core velocities. Therefore, a measured velocity profile allows the acquisition of the apparent shear rates of many virtual tube flows. These virtual tube flows have different wall shear stresses because of the differences in radii despite having the same pressure gradient. With the apparent shear rate and the wall shear stress, the Rabinowitsch correction has been conducted to retrieve the true wall shear rate, which facilitates accurate estimation of the viscosity and the Reynolds number. It has been found that the obtained Reynolds number closely follows the generalized Reynolds number.
Exploring Religiosity and Spirituality in Coping With Sport Injuries
Authors: Wiese-Bjornstal Diane M. , Wood Kristin N. , Wambach Amanda J. , White Andrew C. , Rubio Victor J.
Published: September 2018

The purpose of this study was to explore religiosity/spirituality (R/S) in coping with sport injuries, based on predictions of the integrated model of psychological response to the sport injury and rehabilitation process. A concurrent mixed methods design framed an online survey incorporating quantitative measures of R/S identification and commitment, health locus of control for sport injury, and ways of coping with sport injury, as well as qualitative open-ended questions about mechanisms through which R/S affected and was affected by coping with sport injuries. Participants included 49 physically active adults who experienced sport injuries, with 37 identifying as R/S. Quantitative findings among R/S participants showed religious commitment was a predictor of God health locus of control and positive religious coping. Quantitative results relative to differences between R/S and no-R/S participants showed that those self-identified as R/S relied on a God health locus of control and utilized active coping more so than did those self-identified as no-R/S, whereas no-R/S participants relied more than did R/S participants on an internal health locus of control. Thematic analyses exploring qualitative data revealed three main themes characterizing mechanisms through which R/S affected and was affected by coping with sport injuries: positive, negative, and no R/S coping strategies and effects. Findings support the predictions of the integrated model of psychological response to the sport injury and rehabilitation process and provide evidence-bases for clinical and counseling interventions that reflect cultural competence in accommodating patient or client R/S during recovery from sport injury.
Elite Academy Soccer Players’ Perceptions Towards Cognitive Behavioral Therapy
Authors: Wilkins Luke , Sweeney Jen , Zaborski Zoella , Nelson Carl , Tweddle Simon , Beukes Eldre , Allen Peter
Published: September 2018

The purpose of the present study was to address perceptions towards Cognitive Behavioral Therapy (CBT) in soccer. Twenty-four male, elite academy soccer players (Mage = 20.04) completed a custom-made questionnaire which included education on CBT. The results found that: i) initially, only 8% of players had heard of CBT whilst only 4% of players knew what CBT was, ii) players strongly agreed that CBT should be offered to all players, iii) not knowing how/where to seek help was identified as the main barrier to CBT, iv) players indicated a preference for one-to-one and face-to-face CBT, as opposed to small-group or online-CBT, and v) players perceived they would receive most support from family/friends, and least support from teammates, if they were to undertake CBT. These findings demonstrate that whilst initial awareness and knowledge of CBT is low, general perceptions towards CBT are positive once athletes are educated on the area.
Letting Go of Gold: Examining the Role of Autonomy in Elite Athletes’ Disengagement from Their Athletic Careers and Well-Being in Retirement
Authors: Holding Anne , Fortin Jo-Annie , Carpentier Joëlle , Hope Nora , Koestner Richard
Published: September 2018

Retirement from competitive sports significantly influences former athletes’ well-being. We propose that disengaging from the former athletic career is a crucial factor in retired athletes’ adaptation. Using the theoretical framework of Self-Determination Theory (SDT) we propose that sport motivation at the career peak and motivation for retirement are important determinants of athletes’ disengagement progress from a terminated athletic career. We also seek to examine how motivation for retirement and disengagement progress predict retired athletes’ well-being. Using a mixed-retrospective/prospective longitudinal design we followed 158 government-supported elite athletes who had recently retired from an athletic career. In two online surveys administered 1.5 years apart, retired athletes reported on motivation, disengagement, and well-being. Results suggested that SDT motivation factors are important predictors for elite athletes career disengagement and well-being in retirement. The clinical implications of these findings for athletic career transition and support programs are discussed.
Turning the Corner: A Comparison of Collegiate Athletes’ and Non-Athletes’ Turning Points in Eating Disorder Recovery
Authors: Arthur-Cameselle Jessyca N. , Curcio Molly
Published: September 2018

The purpose of this qualitative study was to identify turning points in eating disorder recovery in collegiate female athletes compared to non-athletes. The sample included 12 varsity athletes and 17 non-athlete college students who previously met criteria for Anorexia Nervosa (AN; n = 17); Bulimia Nervosa (BN; n = 3); Binge Eating Disorder (n = 1); or both AN and BN (n = 8). Participants completed individual interviews and responses were analyzed inductively. There was some commonality in the athletes’ and non-athletes’ experiences. For example, the most frequent turning point for both groups was Insight/Self Realization. Regarding the next three most frequent turning points, athletes reported Sport Performance, Confrontation, and Support/Concern from Others, whereas non-athletes reported Professional Treatment, Hitting a Low, and Support/Concern from Others. This study contributes to the sparse literature on competitive athletes’ recovery. Results indicated that athletes’ turning points differed from non-athletes; therefore, findings are discussed concerning athlete-specific treatment recommendations and suggestions for coaches.
Eating Disorders in Sport: Comparing Eating Disorder Symptomatology in Athletes and Non-Athletes During Intensive Eating Disorder Treatment
Authors: Fewell Laura K. , Nickols Riley , Schlitzer Tierney Amanda , Levinson Cheri A.
Published: September 2018

The current study tested if athlete patients differed from non-athlete patients in measures of eating disorder (ED) and related pathology. Athlete (n = 91 in Study 1; n = 39 in Study 2) and non-athlete (n = 76 in Study 1; n = 26 in Study 2) patients completed self-report measures, and body mass index (BMI) was calculated. Athlete patients had significantly lower ED symptomatology and depression than non-athlete patients (ps < .05). ED impairment, worry, psychosocial functioning, BMI, obsessive-compulsiveness, and compulsive exercise did not significantly differ between groups (ps > .08). Greater ED symptomatology was associated with higher psychosocial functioning among athlete patients and higher obsessive-compulsive symptoms and compulsive exercise among non-athlete patients. This is a novel study comparing ED symptomatology and related measures of mental health in athlete and non-athlete patients engaged in residential or partial hospitalization ED treatment. Future research should further investigate how participation in high-level sport impacts the presentation, treatment, and outcome of individuals with EDs.
Multidimensional spectroscopy with attosecond extreme ultraviolet and shaped near-infrared pulses
Authors: Marroux Hugo J. B. , Fidler Ashley P. , Neumark Daniel M. , Leone Stephen R.
Published: September 2018

We demonstrate the first multidimensional spectroscopy in the extreme ultraviolet using attosecond pulses and pulse shaping.
Efficient Counterselection for Methylococcus capsulatus (Bath) by Using a Mutated
pheS
Gene
Authors: Ishikawa Masahito , Yokoe Sho , Kato Souichiro , Hori Katsutoshi
Published: September 2018

Methanotrophs have long been considered promising strains for biologically reducing methane from the environment and converting it into valuable products, because they can oxidize methane at ambient temperatures and pressures. Although several methodologies and tools for the genetic manipulation of methanotrophs have been developed, their mutagenic efficiency remains lower than that of tractable strains such as
Escherichia coli
. Therefore, further improvements are still desired. The significance of our study is that we increased the efficiency of counterselection in
M. capsulatus
(Bath) by employing
pheS
*, which was newly constructed as a counterselectable marker. This will allow for the efficient production of gene-disrupted and gene-integrated mutants of
M. capsulatus
(Bath). We anticipate that this counterselection system will be utilized widely by the methanotroph research community, leading to improved productivity of methane-based bioproduction and new insights into methanotrophy.
Chromate Resistance Mechanisms in Leucobacter chromiiresistens
Authors: Sturm Gunnar , Brunner Stefanie , Suvorova Elena , Dempwolff Felix , Reiner Johannes , Graumann Peter , Bernier-Latmani Rizlan , Majzlan Juraj , Gescher Johannes
Published: September 2018

Chromate is a highly toxic oxyanion. Extensive industrial use and inadequate waste management has caused the toxic pollution of several field sites. Understanding the chromate resistance mechanisms that enable organisms to thrive under these conditions is fundamental to develop (micro)biological strategies and applications aiming at bioremediation of contaminated soils or waters. Potential detoxifying microorganisms are often not sufficient in their resistance characteristics to effectively perform, e.g., chromate reduction or biosorption. In this study, we describe the manifold strategies of
L. chromiiresistens
to establish an extremely high level of chromate resistance. The multitude of mechanisms conferring it make this organism suitable for consideration as a new model organism to study chromate resistance.
Sleep and epilepsy: unfortunate bedfellows
Authors: Gibbon Frances Mary , Maccormac Elizabeth , Gringras Paul
Published: September 2018

The relationship between sleep and seizure disorders is a particularly vicious cycle. Nocturnal seizures can interrupt sleep while a number of factors, including antiepileptics and sleep disorders that cause sleep fragmentation, can worsen seizures. Understanding and managing seizures and related sleep disturbance is therefore an important and treatable intervention target that could potentially improve children’s sleep, but also their learning, mood, behaviour, seizures and parental quality of life.
Exploration of ‘perception of self’ as medical leader: does perception of self require a paradigm shift from clinician to clinical leader?
Authors: Moen Charlotte , Brown Jeremy , Kaehne Axel
Published: September 2018

Background

Clinical leadership is key to quality improvement; however, there is limited research regarding doctors’ perceptions of clinical leadership.

Aim

To investigate senior trainees’ perception of self as medical leader and explore what influenced their perception.

Methods

A questionnaire with open and closed questions was distributed before and after a medical leadership module. Twelve trainees were then interviewed.

Results

One hundred and fifty-six questionnaires were completed (95.7 % response rate). A significant number of senior trainees did not consider themselves to be a leader; however, there was a statistically significant shift in their self-perception during the programme. Themes identified during the interviews includeda lack of understanding of the leadership concept,a lack of clarity of the medical leader’s roleandvehicles for perspective transformation.

Conclusions

To our knowledge, this is the first study to explore senior trainees’ perception of self as medical leader. Findings suggest, following a paradigm shift from clinician to clinical leader, senior trainees are a potential, valuable resource for quality improvement. To aid understanding of the leadership self-development process, a conceptual model is offered. The significance of the model is its focus on the individual’s leadership paradigm, as the starting point for self-exploration. This model could inform leadership development programmes.
The politics of female pain: women’s citizenship, twilight sleep and the early birth control movement
Authors: MacIvor Thompson Lauren
Published: September 2018

The medical intervention of ‘twilight sleep’, or the use of a scopolamine–morphine mixture to anaesthetise labouring women, caused a furore among doctors and early 20th-century feminists. Suffragists and women’s rights advocates led the Twilight Sleep Association in a quest to encourage doctors and their female patients to widely embrace the practice. Activists felt the method revolutionised the notoriously dangerous and painful childbirth process for women, touting its benefits as the key to allowing women to control their birth experience at a time when the maternal mortality rate remained high despite medical advances in obstetrics. Yet many physicians attacked the practice as dangerous for patients and their babies and antithetical to the expectations for proper womanhood and motherly duty. Historians of women’s health have rightly cited Twilight Sleep as the beginning of the medicalisation and depersonalisation of the childbirth process in the 20th century. This article instead repositions the feminist political arguments for the method as an important precursor for the rhetoric of the early birth control movement, led by Mary Ware Dennett (a former leader in the Twilight Sleep Association) and Margaret Sanger. Both Twilight Sleep and the birth control movement represent a distinct moment in the early 20th century wherein pain was deeply connected to politics and the rhetoric of equal rights. The two reformers emphasised in their publications and appeals to the public the vast social significance of reproductive pain—both physical and psychological. They contended that women’s lack of control over both pregnancy and birth represented the greatest hindrance to women’s fulfilment of their political rights and a danger to the healthy development of larger society. In their arguments for legal contraception, Dennett and Sanger placed women’s pain front and centre as the primary reason for changing a law that hindered women’s full participation in the public order.
Three-dimensional material point method modeling of runout behavior of the Hongshiyan landslide
Authors: Xu Xiaorong , Jin Feng , Sun Qicheng , Soga Kenichi , Zhou Gordon G.D.
Published: September 2018

This study presents a field-scale simulation of the Hongshiyan landslide in China. It uses an advanced numerical approach (material point method (MPM)) and a constitutive model (the Drucker–Prager model + μ(I) rheological relation) for the three-dimensional (3D) simulation. The performance of the developed MPM model is validated with laboratory-scale experimental data on granular collapse before being applied to field-scale analyses. ArcGIS data are used to create a 3D MPM model of the soil body with complicated geometry. Although the developed model can describe the multiple phases of granular flow, it focuses on the runout behavior of the landslide in this work. The landslide is assumed to have occurred suddenly due to an earthquake, and global sudden failure rather than progressive failure is modeled. The MPM simulation results match reasonably well with the measured post-earthquake topography (e.g., deposit height of about 120 m and stretch length of about 900 m in the river) and landslide duration of about 1 min. The velocity of the sliding mass increases rapidly during flow, especially in the first 20 s. The velocity profiles along the depth direction at different locations of the sliding body exhibit an exponential distribution similar to that of a Bagnold-type profile, indicating that the sliding body is fully mobilized. The rate-dependent dissipation parameter β used in the model significantly influences the runout behavior (e.g., flow speed, velocity distribution, and deposit shape).
Five-dimensional spherical symmetric perfect fluid collapse in f(R, T) gravity
Authors: Amir M. Jamil , Sattar Sadia
Published: September 2018

This paper contains the study of spherically symmetric perfect fluid collapse in the framework of f(R, T) modified theory of gravity using five-dimensional background. We consider the five-dimensional spherical symmetric metric as the interior region and a five-dimensional Schwarzschild metric as an exterior region. The Darmois junction conditions between exterior and interior regions are discussed. By taking the particular f(R, T) model, the corresponding field equations are evaluated for both marginally bound L(r) = 1 and non-marginally bound L(r) ≠ 1 cases. We find the gravitational mass of the collapsing system and discuss the apparent horizons and their time formation for different possible cases. Also, the cosmological and black hole horizons have been discussed. It has been concluded that the term involving λ plays a double role: it accelerates the collapse in the region where ρ0 < 4p0 and it slows down the collapsing of matter when ρ0 > 4p0. Further, it is noted that our results reduce to the results found by Sharif and Ahmad (J. Korean Phys. Soc. 52, 980 (2008). doi: 10.3938/jkps.52.980) in general relativity for λ = 0.
Time evolution and thermodynamics for a nonequilibrium system in phase-space
Authors: Wu Chen-Huan
Published: September 2018

The integrable system is constrained strictly by the conservation law during the time evolution, and the prethermal state from the nearly integrable system is also constrained by the conserved parameters (the constants of motion) with the corresponding generalized Gibbs ensemble (GGE), which is indubitably a powerful tool in the prediction of the relaxation dynamics. For stochastic evolution dynamics with considerable noise, the two-point correlation of local operators (like the density of kinks or transverse magnetization correlators), which do not exhibit the thermal features, display the behaviors of nonthermalization and an asymptotic GGE. In fact it is an asymptotic quasi-steady state with an infinite temperature, therefore the required distance to the nonthermal steady state is in an infinite time average. In this paper, we unambiguously investigate the relaxation of a nonequilibrium system in a canonical ensemble for integrable and nonintegrable systems. Temporal behavior of the many-body quantum system and the corresponding linear-coupling between the harmonic oscillators are discussed. The matrix-method in entropy ensemble is utilized to discuss the boundary and the diagonalization algebraically. The approximation results for nonintegrable system under the considerable perturbations are also presented.
Study on the growth and optical properties of ZnO thin films fabricated by ultrasonic spray pyrolysis
Authors: Yang Weiguang , Yang Zhen , Li Ding , Zhang Xiaoying , Zhou Ziliang , Tian Song , Tong Yanqiu , Xia Chuanhui , Liu Miao , Li Li , Wang Feng
Published: September 2018

In this paper, ZnO nanofilms are prepared on quartz substrate by ultrasonic spray pyrolysis (USP) technology. The effects of substrate temperature and deposition time on the micro-structural, morphological and optical properties of ZnO thin films are investigated in detail. Measurements indicate that the growth process of the film is as follows: Micro grains accumulation [Formula: see text] grains’ expansion [Formula: see text] grow into certain nanostructures under different temperature. Nanostructures of the film are as follows: Irregular broken hexagonal-like structure ([Formula: see text]C); coexisting of broken hexagonal- and sheet-like structure (450–500[Formula: see text]C); regular closed packed sheets-like structure ([Formula: see text]C). In addition, all results show that RMS roughness of the films is less than 20 nm. Moreover, the visible transmittance of these samples is higher than 90%. Which display that ZnO films with low roughness and excellent optical properties can be also fabricated by low-cost USP method.
No surface-knot of genus one has triple point number two
Authors: Al Kharusi A. , Yashiro T.
Published: September 2018

It is known that there is no 2-knot with triple point number two. The present paper shows that there is no surface-knot of genus one with triple point number two.
Smoothing closed gridded surfaces embedded in ℝ4
Authors: Díaz Juan Pablo , Hinojosa Gabriela , Valdez Rogelio , Verjovsky Alberto
Published: September 2018

We say that a topological [Formula: see text]-manifold [Formula: see text] is a cubical [Formula: see text]-manifold if it is contained in the [Formula: see text]-skeleton of the canonical cubulation [Formula: see text] of [Formula: see text] ([Formula: see text]). In this paper, we prove that any closed, oriented cubical [Formula: see text]-manifold has a transverse field of 2-planes in the sense of Whitehead and therefore it is smoothable by a small ambient isotopy.
A distance on the equivalence classes of spherical curves generated by deformations of type RI
Authors: Funakoshi Yukari , Hashizume Megumi , Ito Noboru , Kobayashi Tsuyoshi , Murai Hiroko
Published: September 2018

In this paper, we introduce a distance [Formula: see text] on the equivalence classes of spherical curves under deformations of type RI and ambient isotopies. We obtain an inequality that estimate its lower bound (Theorem 1). In Theorem 2, we show that if for a pair of spherical curves [Formula: see text] and [Formula: see text], [Formula: see text] and [Formula: see text] and [Formula: see text] satisfy a certain technical condition, then [Formula: see text] is obtained from [Formula: see text] by a single weak RIII only. In Theorem 3, we show that if [Formula: see text] and [Formula: see text] satisfy other conditions, then [Formula: see text] is ambient isotopic to a spherical curve that is obtained from [Formula: see text] by a sequence of a particular local deformations, which realizes [Formula: see text].
Index polynomials for virtual tangles
Authors: Petit Nicolas
Published: September 2018

We generalize the index polynomial invariant, originally introduced by Turaev [Cobordism of knots on surfaces, J. Topol. 1(2) (2008) 285–305] and Henrich [A sequence of degree one vassiliev invariants for virtual knots, J. Knot Theory Ramifications 19(4) (2010) 461–487], to the case of virtual tangles. Three polynomial invariants result from this generalization; we give a brief overview of their definition and some basic properties.
A DYNAMIC MODEL OF CENTRAL COUNTERPARTY RISK
Authors: BIELECKI TOMASZ R. , CIALENCO IGOR , FENG SHIBI
Published: September 2018

We introduce a dynamic model of the default waterfall of derivatives central counterparties and propose a risk sensitive method for sizing the initial margin, and the default fund and its allocation among clearing members. Using a Markovian structure model of joint credit migrations, our evaluation of the default fund takes into account the joint credit quality of clearing members as they evolve over time. Another important aspect of the proposed methodology is the use of the time consistent dynamic risk measures for computation of the initial margin and the default fund. We carry out a comprehensive numerical study, where, in particular, we analyze the advantages of the proposed methodology and its comparison with the currently prevailing methods used in industry.
THE EFFECTS OF SCOLIOSIS ON SPINAL MUSCLES LENGTH AND JOINT CONTACT FORCES
Authors: NADI AZADEH , KARIMI MOHAMMAD TAGHI , FATOYE FRANCIS , JAFARI AZADEH
Published: September 2018

Background: Although there are a few studies on kinetic and kinematic parameters of scoliotic subjects, it is still controversial whether gait performance of scoliotic subjects differs from that of normal subjects or not. Moreover, there is lack of information regarding joint contact force of scoliotic on convex and concave sides. Therefore, this study examined these issues.

Method: Two groups of children (healthy and children with scoliosis, each group consisting of 5 subjects) participated in this study. The force applied on leg and motions of body parts were evaluated using a Kistler force plate and motion analysis system, respectively. Joint contact forces, muscles length were evaluated in both groups and on both sides (in scoliotic subjects) with OpenSim software. The difference in the parameters between healthy children and scoliotic subjects, and also concave and convex sides, was determined using the independent [Formula: see text] test. [Formula: see text] value was set at [Formula: see text].

Results: The results of this study showed that there was no difference between the forces applied on the leg, range of motions of the joints (hip, knee, ankle, pelvic and trunk), muscles length and joint contact force, neither between normal and children with scoliosis, nor between concave and convex sides [Formula: see text].

Conclusion: The findings revealed that scoliosis deformity with curve less than [Formula: see text] does not have any significant effect on joint contact force, kinetic and kinematic parameters.
Study on a susceptible–infected–vaccinated model with delay and proportional vaccination
Authors: Gan Shuqi , Wei Fengying
Published: September 2018

A susceptible–infected–vaccinated epidemic model with proportional vaccination and generalized nonlinear rate is formulated and investigated in the paper. We show that the stochastic epidemic model admits a unique and global positive solution with probability one when constructing a proper [Formula: see text]-function therewith. Then a sufficient condition that guarantees the disappearances of diseases is derived when the indicator [Formula: see text]. Further, if [Formula: see text], then we obtain that the solution is weakly permanent with probability one. We also derived the sufficient conditions of the persistence in the mean for the susceptible and infected when another indicator [Formula: see text].
Duality relations for second-order programming problem under (G,αf)-bonvexity assumptions
Authors: Dubey Ramu , Mishra Vishnu Narayan , Tomar Puneet
Published: September 2018

In this paper, we introduce the definition of [Formula: see text]-bonvex/[Formula: see text]-pseudobonvex functions and to show the existence of such functions, we construct nontrivial numerical examples. In the next section, we formulate a pair of second-order symmetric dual model in optimization problem and proved the duality results under [Formula: see text]-bonvexity/[Formula: see text]-pseudobonvexity assumptions. Further, we also construct nontrivial concrete examples which justifying definitions as well as the weak duality theorem presented in the paper.
Effects of erosional scours on reservoir properties of heterolithic, distal lower-shoreface sandstones
Authors: Onyenanu God'spower I. , Hampson Gary J. , Fitch Peter J. R. , Jackson Matthew D.
Published: September 2018

Distal intervals of interbedded sandstones and mudstones in shallow-marine, wave-dominated shoreface and deltaic reservoirs may contain significant hydrocarbon resources, but their reservoir properties are difficult to predict. Relatively small-scale (200 × 100 × 20 m) three-dimensional object-based reservoir models, conditioned to outcrop analogue data, have been used to investigate the controls on the proportion of sandstone, the proportion of sandstone beds that are connected by sandstone-filled erosional scours and the effective vertical-to-horizontal permeability ratio (
k
v
/
k
h
) of such intervals. The proportion of sandstone is controlled by sandstone-bed and mudstone-interbed thickness, and by parameters that describe the geometry, dimensions and lateral-stacking density of sandstone-filled scours. Sandstone-bed connectivity is controlled by the interplay between the thickness of mudstone interbeds and sandstone-filled erosional scours. Effective
k
v
/
k
h
is controlled by the proportion of sandstone, which represents the effects of variable distributions and dimensions of mudstones produced by scour erosion, provided that scour thickness is greater than mudstone-interbed thickness. These modelling results provide a means of estimating the effective
k
v
/
k
h
at the scale of typical reservoir-model grid cells using values of mudstone-interbed thickness and the proportion of sandstone that can potentially be provided by core data.
You, the Web, and Your Device
Authors: Vassio Luca , Drago Idilio , Mellia Marco , Houidi Zied Ben , Lamali Mohamed Lamine
Published: September 2018

Understanding how people interact with the web is key for a variety of applications, e.g., from the design of effective web pages to the definition of successful online marketing campaigns. Browsing behavior has been traditionally represented and studied by means of
clickstreams
, i.e., graphs whose vertices are web pages, and edges are the paths followed by users. Obtaining large and representative data to extract clickstreams is, however, challenging.

The evolution of the web questions whether browsing behavior is changing and, by consequence, whether properties of clickstreams are changing. This article presents a longitudinal study of clickstreams from 2013 to 2016. We evaluate an anonymized dataset of HTTP traces captured in a large ISP, where thousands of households are connected. We first propose a methodology to identify actual URLs requested by users from the massive set of requests automatically fired by browsers when rendering web pages. Then, we characterize web usage patterns and clickstreams, taking into account both the temporal evolution and the impact of the device used to explore the web. Our analyses precisely quantify various aspects of clickstreams and uncover interesting patterns, such as the typical short paths followed by people while navigating the web, the fast increasing trend in browsing from mobile devices, and the different roles of search engines and social networks in promoting content.

Finally, we contribute a dataset of anonymized clickstreams to the community to foster new studies.1
A Systematic Literature Review of Automated Feedback Generation for Programming Exercises
Authors: Keuning Hieke , Jeuring Johan , Heeren Bastiaan
Published: September 2018

Formative feedback, aimed at helping students to improve their work, is an important factor in learning. Many tools that offer programming exercises provide automated feedback on student solutions. We have performed a systematic literature review to find out what kind of feedback is provided, which techniques are used to generate the feedback, how adaptable the feedback is, and how these tools are evaluated. We have designed a labelling to classify the tools, and use Narciss’ feedback content categories to classify feedback messages. We report on the results of coding a total of 101 tools. We have found that feedback mostly focuses on identifying mistakes and less on fixing problems and taking a next step. Furthermore, teachers cannot easily adapt tools to their own needs. However, the diversity of feedback types has increased over the past decades and new techniques are being applied to generate feedback that is increasingly helpful for students.
H2S mediates the vasodilator effect of endothelin-1 in the cerebral circulation
Authors: Patel Shalinkumar , Fedinec Alexander L. , Liu Jiangxiong , Weiss Max A. , Pourcyrous Massroor , Harsono Mimily , Parfenova Helena , Leffler Charles W.
Published: September 2018

H2S is an endogenous gasotransmitter that increases cerebral blood flow. In the cerebral vascular endothelium, H2S is produced by cystathionine δ-lyase (CSE). Endothelin-1 (ET-1) has constrictor and dilator influences on the cerebral circulation. The mechanism of the vasodilation caused by ET-1 may involve endothelium-derived factors. We hypothesize that ET-1-elicited dilation of pial arterioles requires an elevation of H2S production in the cerebral vascular endothelium. We investigated the effects of ET-1 on CSE-catalyzed brain H2S production and pial arteriolar diameter using cranial windows in newborn pigs in vivo. H2S was measured in periarachnoid cerebrospinal fluid. ET-1 (10−12–10−8 M) caused an elevation of H2S that was reduced by the CSE inhibitors propargylglycine (PPG) and β-cyano-l-alanine (BCA). Low doses of ET-1 (10−12–10−11 M) produced vasodilation of pial arterioles that was blocked PPG and BCA, suggesting the importance of H2S influences. The vasodilator effects of H2S may require activation of smooth muscle cell membrane ATP-sensitive K+ (KATP) channels and large-conductance Ca2+-activated K+ (BK) channels. The KATP inhibitor glibenclamide and the BK inhibitor paxilline blocked CSE/H2S-dependent dilation of pial arterioles to ET-1. In contrast, the vasoconstrictor response of pial arterioles to 10−8 M ET-1 was not modulated by PPG, BCA, glibenclamide, or paxilline and, therefore, was independent of CSE/H2S influences. Pial arteriolar constriction response to higher levels of ET-1 was independent of CSE/H2S and KATP/BKCa channel activation. These data suggest that H2S is an endothelium-derived factor that mediates the vasodilator effects of ET-1 in the cerebral circulation via a mechanism that involves activation of KATP and BK channels in vascular smooth muscle.

NEW & NOTEWORTHY Disorders of the cerebral circulation in newborn infants may lead to lifelong neurological disabilities. We report that vasoactive peptide endothelin-1 exhibits vasodilator properties in the neonatal cerebral circulation by stimulating production of H2S, an endothelium-derived messenger with vasodilator properties. The ability of endothelin-1 to stimulate brain production of H2S may counteract the reduction in cerebral blood flow and prevent the cerebral vascular dysfunction caused by stroke, asphyxia, cerebral hypoxia, ischemia, and vasospasm.
RNA-Binding Protein HuR Regulates Both Mutant and Wild-Type IDH1 in IDH1-Mutated Cancer
Authors: Zarei Mahsa , Lal Shruti , Vaziri-Gohar Ali , O'Hayer Kevin , Gunda Venugopal , Singh Pankaj K. , Brody Jonathan R. , Winter Jordan M.
Published: September 2018

Isocitrate dehydrogenase 1 (IDH1) is the most commonly mutated metabolic enzyme in human malignancy. A heterozygous genetic alteration, arginine 132, promotes the conversion of α-ketoglutarate to D-2-hydroxyglutarate (2-HG). Although pharmacologic inhibitors of mutant IDH1 are promising, resistance mechanisms to targeted therapy are not understood. Additionally, the role of wild-type IDH1 (WT.IDH1) in cancer requires further study. Recently, it was observed that the regulatory RNA-binding protein, HuR (ELAVL1), protects nutrient-deprived cancer cells without IDH1 mutations, by stabilizing WT.IDH1 transcripts. In the present study, a similar regulatory effect on both mutant (Mut.IDH1) and WT.IDH1 transcripts in heterozygous IDH1-mutant tumors is observed. In ribonucleoprotein immunoprecipitation assays of IDH1-mutant cell lines, wild-type and mutant IDH1 mRNAs each bound to HuR. Both isoforms were profoundly downregulated at the mRNA and protein levels after genetic suppression of HuR (siRNAs or CRISPR deletion) in HT1080 (R132C IDH1 mutation) and BT054 cells (R132H). Proliferation and invasion were adversely affected after HuR suppression and metabolomic studies revealed a reduction in Pentose Phosphate Pathway metabolites, nucleotide precursors, and 2-HG levels. HuR-deficient cells were especially sensitive to stress, including low glucose conditions or a mutant IDH1 inhibitor (AGI-5198). IDH1-mutant cancer cells were rescued by WT.IDH1 overexpression to a greater extent than Mut.IDH1 overexpression under these conditions. This study reveals the importance of HuR's regulation of both mutant and wild-type IDH1 in tumors harboring a heterozygous IDH1 mutation with implications for therapy.

Implications:

This study highlights the HuR–IDH1 (mutant and wild-type IDH1) regulatory axis as a critical, actionable therapeutic target in IDH1-mutated cancer, and incomplete blockade of the entire HuR–IDH1 survival axis would likely diminish the efficacy of drugs that selectively target only the mutant isoenzyme.
Genome-Informed Targeted Therapy for Osteosarcoma
Authors: Sayles Leanne C. , Breese Marcus R. , Koehne Amanda L. , Leung Stanley G. , Lee Alex G. , Liu Heng-Yi , Spillinger Aviv , Shah Avanthi T. , Tanasa Bogdan , Straessler Krystal , Hazard Florette K. , Spunt Sheri L. , Marina Neyssa , Kim Grace E. , Cho Soo-Jin , Avedian Raffi S. , Mohler David G. , Kim Mi-Ok , DuBois Steven G. , Hawkins Douglas S. , Sweet-Cordero E. Alejandro
Published: September 2018

Osteosarcoma is a highly aggressive cancer for which treatment has remained essentially unchanged for more than 30 years. Osteosarcoma is characterized by widespread and recurrent somatic copy-number alterations (SCNA) and structural rearrangements. In contrast, few recurrent point mutations in protein-coding genes have been identified, suggesting that genes within SCNAs are key oncogenic drivers in this disease. SCNAs and structural rearrangements are highly heterogeneous across osteosarcoma cases, suggesting the need for a genome-informed approach to targeted therapy. To identify patient-specific candidate drivers, we used a simple heuristic based on degree and rank order of copy-number amplification (identified by whole-genome sequencing) and changes in gene expression as identified by RNA sequencing. Using patient-derived tumor xenografts, we demonstrate that targeting of patient-specific SCNAs leads to significant decrease in tumor burden, providing a road map for genome-informed treatment of osteosarcoma.

Significance:

Osteosarcoma is treated with a chemotherapy regimen established 30 years ago. Although osteosarcoma is genomically complex, we hypothesized that tumor-specific dependencies could be identified within SCNAs. Using patient-derived tumor xenografts, we found a high degree of response for “genome-matched” therapies, demonstrating the utility of a targeted genome-informed approach.

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FAP Delineates Heterogeneous and Functionally Divergent Stromal Cells in Immune-Excluded Breast Tumors
Authors: Cremasco Viviana , Astarita Jillian L. , Grauel Angelo L. , Keerthivasan Shilpa , MacIsaac Kenzie , Woodruff Matthew C. , Wu Michael , Spel Lotte , Santoro Stephen , Amoozgar Zohreh , Laszewski Tyler , Migoni Sara Cruz , Knoblich Konstantin , Fletcher Anne L. , LaFleur Martin , Wucherpfennig Kai W. , Pure Ellen , Dranoff Glenn , Carroll Michael C. , Turley Shannon J.
Published: September 2018

Cancer-associated fibroblasts (CAFs) are generally associated with poor clinical outcome. CAFs support tumor growth in a variety of ways and can suppress antitumor immunity and response to immunotherapy. However, a precise understanding of CAF contributions to tumor growth and therapeutic response is lacking. Discrepancies in this field of study may stem from heterogeneity in the composition and function of fibroblasts in the tumor microenvironment. Furthermore, it remains unclear whether CAFs directly interact with and suppress T cells. Here, mouse and human breast tumors were used to examine stromal cells expressing fibroblast activation protein (FAP), a surface marker for CAFs. Two discrete populations of FAP+ mesenchymal cells were identified on the basis of podoplanin (PDPN) expression: a FAP+PDPN+ population of CAFs and a FAP+PDPN− population of cancer-associated pericytes (CAPs). Although both subsets expressed extracellular matrix molecules, the CAF transcriptome was enriched in genes associated with TGFβ signaling and fibrosis compared with CAPs. In addition, CAFs were enriched at the outer edge of the tumor, in close contact with T cells, whereas CAPs were localized around vessels. Finally, FAP+PDPN+ CAFs suppressed the proliferation of T cells in a nitric oxide–dependent manner, whereas FAP+PDPN− pericytes were not immunosuppressive. Collectively, these findings demonstrate that breast tumors contain multiple populations of FAP-expressing stromal cells of dichotomous function, phenotype, and location.