bluuebunny/crossref_metadata_2025 huggingface dataset:
SCREENING FOR SUDDEN CARDIAC DEATH IN ATHLETES: THE PSYCHOLOGICAL IMPACT OF BEING DIAGNOSED WITH POTENTIALLY LETHAL DISEASE
Authors: Asif I , Price D , Fisher L , Zakrajsek R , Raabe J , Bejar M , Larsen L , Rao A , Harmon K , Drezner J
Published: March 2014

Background

The purpose of cardiovascular screening in athletes is the identification of disorders at risk for sudden cardiac death. No study has assessed the experiences of athletes diagnosed with a serious cardiovascular condition.

Objective

To determine the psychological impact of young athletes who are diagnosed with a potentially lethal cardiac condition.

Design

Semi-structured interview.

Setting

Young competitive US Athletes.

Participants

25 athletes (52% male, 80% Caucasian, median age 17.7) previously diagnosed (>6 months) with potentially lethal cardiac conditions (5 HCM, 8 WPW, 4 LQTS, 3 ASD, 2 SVT, 3 other) voluntarily participated.

Assessment of risk factors

Athletes shared reactions and experiences regarding diagnosis, lifestyle implications, coping strategies, major concerns, and overall impact on psychosocial functioning.

Main outcome measurements

Audio interviews were transcribed and analyzed using consensual qualitative research (CQR) to identify themes and sub-themes.

Results

Athletes recalled anxiety, confusion, denial, and shock shortly after diagnosis. Disqualified collegiate athletes described prolonged emotional impact due to identity change, and had mixed emotions regarding participation in team activities in another role. Disqualified high school athletes were more accepting of their condition and chose to participate in lower intensity sports. Those undergoing simple corrective procedures depicted mentally overcoming their diagnosis quickly with little impact on daily life; however, individuals with cardiomyopathy or channelopathy had persistent reminders such as taking daily medication, monitoring HR during activity, and ensuring the presence of onsite defibrillators in case of cardiac arrest. Only a minority of athletes described emotional support mechanisms from medical programs. Diagnosis often led to new life purposes such as mentoring or coaching. Despite its impact, all athletes were appreciative and would undergo advanced cardiovascular screening again.

Conclusions

College athletes and those with cardiac conditions requiring disqualification from sport are at greater risk of adverse psychological consequences. Improved support mechanisms from medical programs are needed to assist athletes diagnosed with a serious cardiac disorder.
SPORT-RELATED INJURIES DURING YOUTH AND NATIONAL COMBINED EVENTS CHAMPIONSHIPS
Authors: Edouard P , Samozino P , Escudier G , Baldini A , Morin JB
Published: March 2014

Background

In International Association of Athletics Federation and European Athletics competitions, higher injury incidences were reported for athletes participating in combined events.

Objective

To record and analyze the incidence and characteristics of injuries incurred during Youth and National combined events Championships.

Design

Prospective recording of newly occurred injuries.

Setting

French Athletics Combined Events Championships in Athletics 2010 in Saint-Etienne, France.

Participants

Local Organising Committee (LOC) physicians and physiotherapists working in the Medical Centres at the stadium.

Main outcome measures

Incidence and characteristics of newly occurred injuries.

Results

A total of 51 injuries and 9 time-loss injuries were recorded among 107 registered athletes, corresponding in an incidence of 477 injuries and 84 time-loss injuries per 1000 registered athletes. 72.5% of injuries affected lower limbs. The most common diagnosis was thigh strain (17.6%), followed by trunk muscle cramps (11.8%), knee tendinopathy (9.8%), and ankle sprain (9.8%). Overuse injuries were the most common injury cause (60.8%), either with gradual (33.3%) and sudden onset (27.5%), followed by non-contact trauma (31.4%). Among the 14 dropouts recorded, about two third were caused by an injury (57.1%).

Conclusions

During combined events championships at the youth and national, over one third of the registered athletes incurred an injury. This represented a higher injury incidence than during international elite athletics competitions. Moreover, these injuries concerned a younger population and affecting immature musculoskeletal structures. In combined events, preventive interventions should mainly focus on overuse and thigh injuries.
INJURY REPORTING VIA SMS TEXT MESSAGING IN COMMUNITY SPORT
Authors: Ekegren C , Gabbe B , Finch CF
Published: March 2014

Background

The use of text messaging or short message service (SMS) for injury reporting is a recent innovation in sport and has not yet been trialled at the community level. Considering the lack of personnel and resources in community sport, SMS may represent a viable option for ongoing injury surveillance.

Objective

To evaluate the feasibility of injury self-reporting via SMS in community Australian football.

Design

Cohort study.

Setting

Community Australian football clubs.

Participants

Of the 316 Australian football players eligible from four community clubs (male and aged 18+ years), 44% (n=139) agreed to participate. Seventeen participants were lost to follow up over the season.

Main outcome measurements

Consenting players received an SMS after each football round asking whether they had been injured in the preceding week. Outcome variables included the number of SMS-reported injuries, players' response rates and response time. Poisson regression was used to evaluate any change in response rate over the season and the association between response rate and the number of reported injuries.

Results

In the sample of 139 football players, 167 injuries were reported via SMS over the course of the season. The total response rate ranged from 90-98%. Of those participants who replied on the same day, 47% replied within five minutes. The number of reported injuries decreased as the season progressed but this was not significantly associated with a change in the response rate.

Conclusions

The number of injuries reported via SMS was consistent with previous studies in community Australian football. Injury reporting via SMS yielded a high response rate and fast response time and should be considered a viable injury reporting method for community sports settings.
INJURY SURVEILLANCE IN COMMUNITY SPORT: CAN WE OBTAIN VALID DATA FROM SPORTS TRAINERS?
Authors: Ekegren C , Gabbe B , Finch CF
Published: March 2014

Background

A lack of available injury data on non-elite sports participants has hampered the development of informed preventative strategies for the broad base of sports participation. In community sports settings, sports trainers are well-placed to carry out injury surveillance but few studies have evaluated the validity of the data they record.

Objective

To investigate the capture rate, completeness and agreement between sports trainers and other sources of injury data in community sport.

Design

Validation study.

Setting

Community Australian football clubs.

Participants

Of the 316 Australian football players eligible from four community clubs (male and aged 18+ years), 44% (n=139) agreed to participate. Seventeen participants were lost to follow up over the season. At each club, an on-site sports trainer agreed to record players' injuries.

Main outcome measurements

Throughout the football season (16–18 rounds) players reported their injuries to the club's sports trainer. To validate injury data recorded by sports trainers, we obtained self-reported injury data from players via short message service (SMS) and additionally from treating health-care practitioners. We reported the percentage of all injuries registered by sports trainers only, by players only (via SMS) and by both. For any injuries reported by sports trainers, players and health-care practitioners, we reported agreement between sources on a range of injury variables using the kappa (Κ) co-efficient.

Results

In total, 210 discrete injuries were recorded, 59% by players via SMS only, 21% by sports trainers only and 21% by both. Kappa coefficients ranged from 0.32 (0.27–0.37) for date of return to football and 1.00 (1.00–1.00) for activity at time of injury.

Conclusions

Injury data collected by sports trainers within community clubs is of adequate quality for providing an understanding of the profile of injuries. However, data are likely to underestimate true injury rates and therefore must be interpreted with caution.
WEIGHTY PROBLEMS: SPORT INJURIES IN OVERWEIGHT OR OBESE ACTIVE CANADIAN ADOLESCENTS
Authors: Ezzat A , Schneeberg A , Koehoorn M
Published: March 2014

Background

Despite the multitude of benefits of sport participation, it is the leading cause of injury requiring medical attention in Canadian youth. Previous research found both increased exposure to sport and body mass index (BMI) are injury risk factors. As a modifiable risk factor, further examination of the association between being obese or overweight and sport injury is warranted, accounting for sport exposure level.

Objective

To examine the relationship between sport injury and overweight and obese weight, versus normal weight, among a sub-sample of adolescents. It is hypothesized that overweight and obese adolescents will have increased odds of sport injury.

Design

Cross-sectional analysis of the national population-based Canadian Community Health Survey (2009/10) by Statistics Canada.

Setting

Canada.

Participants

Nationally representative sample (n=6163) of Canadian adolescents aged 12–19 years, classified ‘active’ by daily energy expenditure in physical activity minimum 3 METS (Kcal/kg/day).

Risk factor assessment

BMI was calculated using self-report data. Using Coles Classification System, participants were grouped: normal, overweight, or obese categories. Other variables (sex, ethnicity, daily physical activity, socio-economic status) were included in the multivariable logistic regression analysis to control for confounding.

Main outcome measurements

Sport injury: an injury in the past 12 months while engaged in sport or exercise.

Results

Among the sample of active adolescents, 25% (n=1 529) reported a sport injury in the past 12 months. In the final adjusted model, no significant relationship was found between being overweight and sport injury (OR=1.05 95% CI=0.90–1.22). A significantly reduced odds of sport injury was observed among obese adolescents (OR=0.72 95% CI=0.53–0.99) compared to their normal weight counterparts.

Conclusions

Overweight or obese active adolescents do not appear to be at increased risk of sports injury in this sample. The decreased odds among obese adolescents may be because of differences in intensity of sport participation or type of sporting activity.
PSYCHOLOGICAL IMPLICATIONS OF ADVANCED CARDIAC SCREENING: NO DIFFERENCES IN ANXIETY LEVELS BASED ON REASON FOR FALSE POSITIVE RESULT
Authors: Asif I , Price D , Jenkins J , Lett A , Irwin M , Johnson S , Toresdahl B , Pelto H , Smith T , Harmon K , Drezner J
Published: March 2014

Background

The American Heart Association (AHA) cites excessive anxiety in athletes with false positive results as a major deterrent to ECG screening during the PPE. No study has examined the experiences of athletes with false positive test results during cardiovascular screening.

Objective

To determine the psychological impact of young athletes with false positive results by history, exam, or ECG during cardiovascular screening.

Design

Prospective, multi-site investigation (22 schools).

Setting

Young competitive athletes.

Participants

1 506 high school athletes (59.3% male, mean age 15.5 years, 53.7% Caucasian, 23.4% African American).

Assessment of risk factors

Athletes underwent screening with a standardized AHA-based history and physical exam and ECG.

Main outcome measurements

Pre- and post-screen validated assessments for health attitudes, anxiety, and impact of screening on sport.

Results

74.1% of athletes had normal screens, 22.1% false positive results (12.9% history, 4.2% exam, 3.1% ECG), and 0.9% were diagnosed with a cardiac disorder. Before screening, females preferred to know about underlying cardiac conditions compared to males (P<.001). African-Americans were less concerned (P<.001) and less interested (P<.001) in cardiac screening compared to Caucasians. As a group, athletes did not report anxiety during screening and there were no differences in anxiety levels among athletes screening normal or false positive (P=.69). There were no differences in anxiety levels based on reason for false positive result (history, exam, or ECG) both during (P=.95) and after (P=.40) screening. Athletes with false positive outcomes reported they would recommend ECG screening and that it positively impacted their training. Athletes diagnosed with disease described anxiety after screening completion, but felt all athletes should receive an ECG prior to competition.

Conclusions

The AHA supposition that ECG screening causes excessive anxiety in athletes with false positive results is unsubstantiated. Psychological distress should not be used as a rationale against ECG screening.
PELVIC TILT: RELIABILITY OF MEASURING THE STANDING POSITION AND RANGE OF MOTION IN ADOLESCENT ATHLETES
Authors: Fourchet F , Materne O , Rajeb A , Horobeanu C , Farooq A
Published: March 2014

Background

Standing pelvic posture remains a common assessment in sports therapy. The palpation technique assessing the relative position of the anterior and posterior superior iliac spines is widely used to quantify the asymmetry in pelvic position, but the reliability of this approach in adolescent athletes is not determined.

Objective

The aim of the present study was to examine the inter-rater and intra-rater reliability of palpation meter (PALM) measures for assessing standing pelvic tilt in adolescent athletes.

Design

Test-retest study.

Setting

Sports academy physiotherapy laboratory.

Participants

A group of highly-trained adolescent multi-sport athletes (n=75, age=14.9±1.7 yr) training in a national sports academy.

Interventions

On two occasions (10 min apart), two physiotherapists took the measurements of standing neutral pelvic tilt, anterior pelvic tilt and posterior pelvic tilt using the PALM. In each position an average of three measurements was taken by each examiner, alternatively for each side.

Main outcome measurements:

Reliability of standing pelvic tilt measures was assessed by calculating the between-session and the between-physiotherapists differences expressed as Cohen's d and the standard error of measurement (SEM: CV).

Results

All measured parameters showed good inter-rater and intra-rater reproducibility. The standardized differences between two trials or two physiotherapists was trivial with Cohen's d<0.2 in each case. Most importantly the SEM was low when comparing measurements of neutral and anterior pelvic tilts positions between physiotherapists (CV≤15.8% and CV≤8.8% respectively) and between sessions (CV≤14.0% % and CV≤7.3% respectively), but not regarding posterior tilt position (CV≥38.9% between physiotherapists and CV≥24.8% between sessions).

Conclusions

The present method for assessing neutral and anterior standing pelvic tilt measurements has a good reliability level and may integrate longitudinal screening and clinical examination routines in young athletes. However, posterior pelvic tilt measurements should be cautiously interpreted due to lower measurements' reliability.
SAGITTAL SPINAL CURVATURES IN MAXIMAL TRUNK FLEXION OF YOUNG FEMALE DANCERS
Authors: Esparza-Ros F , Vaquero-Cristóbal R , Alacid F , Martínez-Ruiz E , López-Miñarro PA
Published: March 2014

Background

Kyphotic postures in both thoracic and lumbar curves have been associated to increased shear and compressive forces in the intervertebral joints. Hamstring extensibility influences pelvic, thoracic and lumbar curvatures when trunk bending movements are performed. Some studies have found higher hamstring muscle extensibility in dancers than other athletes.

Objective

To classify sagittal thoracic and lumbar curves when performed a maximum trunk flexion with knees extended (sit-and-reach test) in female dancers with high hamstring extensibility.

Design

Descriptive study.

Setting

Dance Conservatory professional. The sample included dance students of Professional education teaching.

Participants

86 female dancers (mean±SD, age: 15.18±2.62 years-old) with a straight leg raise test greater than 90° were recruited for this study.

Interventions

Not applicable.

Main outcome measurements

Thoracic and lumbar curvatures were measured when maximal trunk flexion with knees extended (sit-and-reach test) was reached using a Spinal Mouse®. Thoracic values were classificated in three categories: slight (<45°), mild (45–60°) or high (>60°) kyphotic curve. Lumbar values were also classificated in three categories: slight (<23°), mild (23–31°) or high (>31°) kyphotic curve.

Results

Most dancers showed slight (43.02%) and mild (33.72%) thoracic curvature whereas the frequency of high thoracic kyphosis was 23.26%. Thirty-seven dancers showed thoracic angles between -5 and 44° (slight group) (mean value: 30.35±11.42°). The mean thoracic kyphosis of mild group was 51.55±4.80°. The high group showed values between 61 and 79° (mean value: 66.95±5.43°). With regards to the lumbar curvature, a large amount of the sample showed high (46.51%) and mild (37.20%) kyphotic curves.

Conclusions

Dance training is associated to increased lumbar kyphosis when maximum trunk flexion with knees extended is performed. Greater intervertebral bending of the lumbar spine in dancers could be associated to their high hamstring extensibility.
THE EFFECT OF CRYOTHERAPY APPLICATION TO THE ANKLE JOINT ON DYNAMIC POSTURAL STABILITY IN AN ELITE ATHLETIC POPULATION
Authors: Fullam K , Caulfield B , Coughlan GF , Delahunt E
Published: March 2014

Background

Decreased postural stability is a primary risk factor for lower limb musculoskeletal injuries. During athletic competitions, cryotherapy may be applied during short breaks in play or during half-time; however its effects on postural stability remain unclear.

Objective

To investigate the acute effects of a 15-minute ankle joint cryotherapy application on dynamic postural stability.

Design

Experimental study.

Setting

University biomechanics laboratory.

Participants

29 elite level collegiate male field-sport athletes.

Interventions

Participants were tested on the anterior (ANT), posterior-lateral (PL) and posterior-medial (PM) reach directions of the Star Excursion Balance Test (SEBT) both pre- and post- a 15-minute ankle joint cryotherapy application.

Main outcome measurements

Normalized reach distances, along with sagittal plane kinematics of the hip, knee and ankle joints, as well as associated MVELO and AREAsw of the center-of-pressure (COP) path during the performance of the ANT, PL and PM reach directions of the SEBT.

Results

There was a statistically significant decrease in ANT, PL and PM reach direction reach distance scores from pre-cryotherapy to post-cryotherapy (P≤.05). No significant differences were observed in hip, knee or ankle joint sagittal plane kinematics (P≥.05). There was a significant decrease in MVELO of the COP path from pre-cryotherapy to post-cryotherapy (P≤.05) in all reach directions (P≤.05). AREAsw of the COP path was significantly decreased from pre-cryotherapy to post-cryotherapy in the ANT and PM reach directions (P≥.05).

Conclusions

The results of the present study indicate that dynamic postural stability is adversely affected immediately following cryotherapy application to the ankle joint.
Production d'une substance rhizogène à effet similaire à celui de l'acide indole acétique par le ver de terreLumbricus terrestris
Authors: Harti Abdellatif El , Saghi Mohamed , Molina J -AE , Teller Gérard
Published: March 2014

In vitro biological tests show that excreta or gross total and partial extracts of Lumbricus terrestris stimulate rhizogenesis and enhance root growth in young plants of the bean Phaseolus vulgaris. Similar results were obtained in experiments with worms freshly collected in the field and with worms previously deprived of food for 4 weeks. The rhizogenous substance produced by the worms is therefore not of exogenous origin, coming from the soil via the digestive tract. The similar effects of indol acetic acid at different concentrations and of excreta and gross extracts of worms in various dilutions indicate that the rhizogenous substance is similar to indol acetic acid, a well-known phytohormone in plants. Expressed as indol acetic acid equivalents, the quantity of the rhizogenous substance in worms would be approximately 18 × 103ng/g, of which half (9 × 103ng/g) is released in the excreta alone.[Journal translation]
Production de composés indoliques rhizogènes par le ver de terre Lumbricus terrestris
Authors: Harti Abdellatif El , Saghi Mohamed , Molina J -AE , Teller Gérard
Published: March 2014

In vitro application of total gross extract of earthworms (Lumbricus terrestris) in diverse dilutions stimulates rhizogenesis in young bean plants (Phaseolus vulgaris). The observed effect is similar to that of indol acetic acid, a well-known growth enhancer in plants, used here as a control in various concentrations. Fragmentation of worm extract by column chromatography results in three groups of fractions. Only the polar group of fractions has a significant rhizogenous effect, which is, however, inferior to that observed in the presence of total gross extract of worms or of indol acetic acid. Gross extract analyses using thin layer chromatography, with appropriate chromatography systems and reagents, revealed that indol acetic acid is not present, but is probably replaced by other indol-derived substances that have a neutral to basic chromatographic behaviour. These presumed indol-derived substances are identified as methyl-tryptophane, serotonin, and hydroxy-indol acetic acid. Analyses using mass spectrometry combined with gas chromatography, following fragmentation and purification of the group of rhyzogenous fractions, have revealed the presence of hydroxy-indol carboxylic acid, which seems to take the form of several isomeres.[Journal translation]
Differential responses of coyotes to novel stimuli in familiar and unfamiliar settings
Authors: Harris Charles E , Knowlton Frederick F
Published: March 2014

We studied behavioral responses of captive and wild coyotes (Canis latrans) toward novel objects and artificial scent stations to determine how they might respond to novel stimuli used in coyote management and research. When captive coyotes encountered novel stimuli in unfamiliar surroundings they showed little avoidance, while the same stimuli caused avoidance and neophobic reactions among coyotes when encountered in familiar surroundings. In the field phase of the study, radio-collared coyotes in southern Texas were intensively monitored in order to relate space-use patterns to the locations where these coyotes were exposed to artificial scent stations. Coyotes were more likely to respond to and score (record visits by leaving tracks) at artificial scent stations when these were encountered outside or on the periphery of their home areas than when they were encountered within their home area. This suggests that indices of coyote abundance that employ responses to novel situations may more readily record coyotes that are outside the central portions of their home areas and that transient or dispersing coyotes are more likely to be "counted" than residents.
Abundance, diversity, and community structure of small mammals in forest fragments in Prince Edward Island National Park, Canada
Authors: Silva M
Published: March 2014

Anthropogenic activities in Prince Edward Island (Canada) have created a mosaic of fragmented uneven-aged forests and agricultural and pasture lands, as well as large amounts of edge habitat. Although the mammalian fauna of the province is largely composed of small mammals, no previous study has investigated how they respond to habitat fragmentation. I surveyed 14 forest fragments in Prince Edward Island National Park to assess the effects of habitat fragmentation on the abundance and diversity of small mammals. A total of 897 small mammals from 11 different species were captured during 10 231 trap-nights. The most frequently captured species were the eastern chipmunk, Tamias striatus (53.5%), and the deer mouse, Peromyscus maniculatus (24.9%). Neither species richness, total population size, nor the ShannonWiener species-diversity index (H') was significantly associated with either fragment area or perimeter length. The results also indicated no difference in species diversity between linear fragments and other-shaped fragments. The only species showing a response to edge habitat was the eastern chipmunk. We concluded that future research in Prince Edward Island National Park should assess the abilities of small mammals and their predators to use edge habitats and agricultural fields.
On CR volume growth estimate in a complete pseudohermitian 3-manifold
Authors: Chang Shu-Cheng , Chang Ting-Hui
Published: March 2014

In this paper, we first derive the CR Reilly's formula and a CR Ricatti equation for sub-Laplacian of the Carnot–Carathéodory distance in a complete pseudohermitian 3-manifold. As a consequence, we obtain the CR volume growth estimate in a complete pseudohermitian 3-manifold under a lower bound of pseudohermitian curvature tensors. This is a generalization of Nagel, Stein and Wainger's volume growth estimate for the Heisenberg ball in the standard Heisenberg group.
A review on speech enhancement algorithms and why to combine with environment classification
Authors: Nidhyananthan S. Selva , Kumari R. Shantha Selva , Prakash A. Arun
Published: March 2014

Speech enhancement has been an intensive research for several decades to enhance the noisy speech that is corrupted by additive noise, multiplicative noise or convolutional noise. Even after decades of research it is still the most challenging problem, because most papers rely on estimating the noise during the nonspeech activity assuming that the background noise is uncorrelated (statistically independent of speech signal), nonstationary and slowly varying, so that the noise characteristics estimated in the absence of speech can be used subsequently in the presence of speech, whereas in a real time environment such assumptions do not hold for all the time. In this paper, we discuss the historical development of approaches that starts from the year 1970 to, the recent, 2013 for enhancing the noisy speech corrupted by additive background noise. Seeing the history, there are algorithms that enhance the noisy speech very well as long as a specific application is concerned such as the In-car noisy environments. It has to be observed that a speech enhancement algorithm performs well with a good estimation of the noise Power Spectral Density (PSD) from the noisy speech. Our idea pops up based on this observation, for online speech enhancement (i.e. in a real time environment) such as mobile phone applications, instead of estimating the noise from the noisy speech alone, the system should be able to monitor an environment continuously and classify it. Based on the current environment of the user, the system should adapt the algorithm (i.e. enhancement or estimation algorithm) for the current environment to enhance the noisy speech.
Regularized lattice BGK versus highly accurate spectral methods for cavity flow simulations
Authors: Montessori Andrea , La Rocca Michele , Falcucci Giacomo , Succi Sauro
Published: March 2014

The regularized lattice BGK (RLBGK) is validated against high-accuracy spectral Chebyshev methods for lid-driven cavity flows. RLBGK is shown to provide a viable alternative to standard lattice BGK schemes, with significant enhancement of numerical stability at a very moderate computational extra-cost.
Competitive dynamics of lexical innovations in multi-layer networks
Authors: Javarone Marco Alberto
Published: March 2014

We study the introduction of lexical innovations into a community of language users. Lexical innovations, i.e. new term added to people's vocabulary, plays an important role in the process of language evolution. Nowadays, information is spread through a variety of networks, including, among others, online and offline social networks and the World Wide Web. The entire system, comprising networks of different nature, can be represented as a multi-layer network. In this context, lexical innovations diffusion occurs in a peculiar fashion. In particular, a lexical innovation can undergo three different processes: its original meaning is accepted; its meaning can be changed or misunderstood (e.g. when not properly explained), hence more than one meaning can emerge in the population. Lastly, in the case of a loan word, it can be translated into the population language (i.e. defining a new lexical innovation or using a synonym) or into a dialect spoken by part of the population. Therefore, lexical innovations cannot be considered simply as information. We develop a model for analyzing this scenario using a multi-layer network comprising a social network and a media network. The latter represents the set of all information systems of a society, e.g. television, the World Wide Web and radio. Furthermore, we identify temporal directed edges between the nodes of these two networks. In particular, at each time-step, nodes of the media network can be connected to randomly chosen nodes of the social network and vice versa. In doing so, information spreads through the whole system and people can share a lexical innovation with their neighbors or, in the event they work as reporters, by using media nodes. Lastly, we use the concept of "linguistic sign" to model lexical innovations, showing its fundamental role in the study of these dynamics. Many numerical simulations have been performed to analyze the proposed model and its outcomes.
The structural comparison of central counterparty interoperability
Authors: Feng Xiaobing , Pritsker Matthew
Published: March 2014

While a more integrated central counterparty (CCP) network via interoperability will provide users more cost efficient clearing and settlement services, it also increases the default transmission through the system. Using epidemic spreading model, it is found that a vertically interoperated CCP network is more robust compared with a horizontally interoperated one when certain condition is satisfied. Variation of the different transmission rates from both internal and external sources leads to different equilibrium. The safe range which is free from the crisis explosion state is identified and can be reached with certain policy coordination among nations.
Features of a 2d gauge theory with vanishing chiral condensate
Authors: Landa-Marbán David , Bietenholz Wolfgang , Hip Ivan
Published: March 2014

The Schwinger model with Nf ≥ 2 flavors is a simple example for a fermionic model with zero chiral condensate Σ (in the chiral limit). We consider numerical data for two light flavors, based on simulations with dynamical chiral lattice fermions. We test properties and predictions that were put forward in the recent literature for models with Σ = 0, which include IR conformal theories. In particular, we probe the decorrelation of low lying Dirac eigenvalues, and we discuss the mass anomalous dimension and its IR extrapolation. Here, we encounter subtleties, which may urge caution with analogous efforts in other models, such as multi-flavor QCD.
Sol-gel-based doped granulated silica for the rapid production of optical fibers
Authors: Romano Valerio , Pilz Soenke , Etissa Dereje
Published: March 2014

In the recent past we have studied the granulated silica method as a versatile and cost effective way of fiber preform production. We have used the sol-gel technology combined with a laser-assisted remelting step to produce high homogeneity rare earth or transition metal-activated microsized particles for the fiber core. For the fiber cladding pure or index-raised granulated silica has been employed. Silica glass tubes, appropriately filled with these granular materials, are then drawn to fibers, eventually after an optional quality enhancing vitrification step. The process offers a high degree of compositional flexibility with respect to dopants; it further facilitates to achieve high concentrations even in cases when several dopants are used and allows for the implementation of fiber microstructures. By this "rapid preform production" technique, that is also ideally suited for the preparation of microstructured optical fibers, several fibers have been produced and three of them will be presented here.
Elastic and electronic properties of cubic cerium oxide under pressure via first principles
Authors: Niu Z. W. , Zhu B. , Cheng Y. , Song R. N. , Ji G. F.
Published: March 2014

The elastic and electronic properties of cubic structure CeO 2 under pressure are investigated in the frame of density functional theory (DFT). By using the local-density approximation (LDA) plus U( LDA +U) method with U = 6 eV, the calculated lattice parameters, bulk modulus and elastic properties of the cubic CeO 2 at 0 GPa and 0 K are in good agreement with the available experimental data. The pressure dependences of lattice parameters, bulk and shear modulus, Debye temperature, Young's moduli, Poisson's ratio and the compressional and shear wave velocities of the cubic CeO 2 are obtained successfully. In addition, the total density of states (TDOS) and the band gaps of the cubic CeO 2 under pressures are also investigated. By comparing the results of LDA and LDA+U, both the conventional LDA and the LDA+U methods can be used to describe the structure of the cubic CeO 2 due to the electronic localization of 4f-electron in Ce which is not so strong. However, the LDA+U approach can obtain a proper shape of the density of electronic states that agrees well with the measured values.
Quantum solitons in the Fermi–Pasta–Ulam model
Authors: Li De-Jun , Tang Bing
Published: March 2014

In this paper, quantum solitons in the Fermi–Pasta–Ulam (FPU) model are investigated analytically. By using the canonical transform method and number-conserving approximation, we obtain the normal form of the phonon-conserving quantized Hamiltonian. In order to convert the quantized Hamiltonian into the coordinate space, we employ the inverse Fourier transform. With the help of the Hartree approximate and the semidiscrete multiple-scale method, the nonlinear Schrödinger (NLS) equation is derived. The results show that quantum solitons may exist in the FPU model. Moreover, it is found that moving quantum solitons become quantum intrinsic localized modes under certain condition. In addition, we obtain the energy level of quantum solitons, which indicates that the energy of such quantum solitons is quantized.
Tiny warming of residual anthropogenicCO2
Authors: Gervais François
Published: March 2014

The residual fraction of anthropogenic CO2emissions which has not been captured by carbon sinks and remains in the atmosphere, is estimated by two independent experimental methods which support each other: the13C /12C ratio and the temperature-independent fraction of d( CO2)/dt on a yearly scale after subtraction of annual fluctuations the amplitude ratio of which reaches a factor as large as 7. The anthropogenic fraction is then used to evaluate the additional warming by analysis of its spectral contribution to the outgoing long-wavelength radiation (OLR) measured by infrared spectrometers embarked in satellites looking down. The anthropogenic CO2additional warming extrapolated in 2100 is found lower than 0.1°C in the absence of feedbacks. The global temperature data are fitted with an oscillation of period 60 years added to a linear contribution. The data which support the 60-year cycle are summarized, in particular sea surface temperatures and sea level rise measured either by tide gauge or by satellite altimetry. The tiny anthropogenic warming appears consistent with the absence of any detectable change of slope of the 130-year-long linear contribution to the temperature data before and after the onset of large CO2emissions.
Recognizing M10 by spectrum in the class of all groups
Authors: Jabara Enrico , Lytkina Daria , Mamontov Andrey
Published: March 2014

We prove that a group with spectrum {1, 2, 3, 4, 5, 8} is locally finite and is isomorphic to M10, where M10 = A6 ⋅ 2 is the 3-transitive Mathieu group of degree 10, i.e. the corresponding maximal subgroup of the sporadic simple group M11.
The cogrowth series forBS(N, N) is D-finite
Authors: Elder Murray , Rechnitzer Andrew , Janse van Rensburg Esaias J. , Wong Thomas
Published: March 2014

We compute the cogrowth series for Baumslag–Solitar groups BS (N, N) = 〈a,b|aNb = baN〉, which we show to be D-finite. It follows that their cogrowth rates are algebraic numbers.
PHYSICAL ORIGINS OF 1/f NOISE IN Si δ-DOPED SCHOTTKY DIODES
Authors: KLYUEV ALEXEY V. , SHMELEV EVGENY I. , YAKIMOV ARKADY V.
Published: March 2014

A model of Schottky diode with δ-doping is suggested. The aim is the determination of technological areas of the diode, which are responsible for the 1/f noise. Series resistance of base and contacts, and the possible leakage are taken into account. Equivalent parameters of the diode are defined from the analysis of the current–voltage characteristic. The model of fluctuations in the charge of non-compensated donors in δ-layer of Schottky junction (ΔNs – model) and model of 1/f noise in leakage current are suggested for an explanation of experimental data. Our study show that, in the investigated diodes, in a million atomic impurities, there are about 1–10 special impurity atoms with stochastically modulated ionization energy.
NOISE-INDUCED OSCILLATING BISTABILITY AND TRANSITION TO CHAOS IN FITZHUGH–NAGUMO MODEL
Authors: BASHKIRTSEVA IRINA , RYASHKO LEV , SLEPUKHINA EUDOKIA
Published: March 2014

Stochastic dynamics of the FitzHugh–Nagumo (FHN) neuron model in the limit cycles zone is studied. For weak noise, random trajectories are concentrated in the small neighborhood of the unforced deterministic cycle. As the noise intensity increases, in the Canard-like cycles zone of the FHN model, a bundle of the stochastic trajectories begins to split into two parts. This phenomenon is investigated using probability density functions for the distribution of random trajectories. It is shown that the intensity of noise generating this splitting bifurcation significantly depends on the stochastic sensitivity of cycles. Using the stochastic sensitivity function (SSF) technique, we find a critical value of the parameter corresponding to the supersensitive cycle. For the neighborhood of this critical value, a comparative parametrical analysis of the phenomenon of the stochastic cycle splitting is performed. To predict the splitting bifurcation and estimate a threshold value of the noise intensity, we use a confidence domains method based on SSF. A phenomenon of the noise-induced chaotization is studied. We show that P-bifurcation of the splitting of stochastic cycles implies a D-bifurcation of a noise-induced chaotization.
A Multi-Product Newsvendor Problem with Budget and Loss Constraints
Authors: Zhou Yanju , Chen Xiaohong , Xu Xuanhua , Yu Changjun
Published: March 2014

The solution space of a multi-product newsvendor problem (MPNP) with two constraints is analyzed and divided by four cases. One constraint is a loss constraint, which is nonlinear and has the integral symbol, while the other is a budget constraint. The threshold values of different solution regions are calculated and the corresponding solving methods for each case are provided, reducing the complexity of problem solving. The paper suggests the loss-based marginal utility deleting method solves non-negative constraint problems, and the linear approximate approach deals with nonlinear constraint optimal problems with an integral symbol in the model. Numerical examples are given, showing that the solving approach is more effective.
The average errors for linear combinations of Bernstein–Kantorovich operators on the Wiener space
Authors: Jiang Yanjie , Zhang Zengbo
Published: March 2014

In this paper, we discuss the average errors of function approximation by linear combinations of Bernstein–Kantorovich operators. The strongly asymptotic orders for the average errors of these operators sequence are determined on the Wiener space.
Functionality indexes assessed through a simple model of muscle activation, fatigue and recovery
Authors: Fattorini Luigi , Lacitignola Deborah
Published: March 2014

A nonlinear dynamical system is proposed as a qualitative mathematical model with the twofold aim to reasonably describe the force behavior in a fatiguing sub-maximal contraction and to be possibly employed in assessing muscular activation indexes. The model's properties are studied in terms of its equilibria and their stability properties and the existence of the fatigue equilibrium is ensured as the only system's attractor in the feasibility range of the parameters. Suitable mathematical indicators — related to the dynamical properties of resilience and reactivity — are introduced to characterize the asymptotic and the transient system's behavior. The practical impact of the analytical results is elucidated and a connection is established between the introduced mathematical indicators and muscle functionality indexes as rate of force development, task failure time and complete restore time. Experimental validation with handgrip force signal at high load and possible practical applications are also presented.
MAGNETIC RESPONSE OF Pr1-xLaCexCuO4 IN COMPARISON WITH HOLE-DOPED CUPRATES
Authors: SHERMAN A.
Published: March 2014

The origin of differences in the magnetic responses of Pr 1-x LaCe x CuO 4 with x = 0.11–0.12 and moderately doped p-type cuprates is investigated using the t–J model, the Mori projection operator technique and dispersions of charge carriers derived from photoemission experiments. These differences are related to the proximity of the former crystal to the boundary of the antiferromagnetic (AF) phase and to the remoteness of p-type compounds from it. This leads to different nesting vectors of the low-frequency equi-energy contours of carrier dispersions in these crystals. The strong nesting with the AF momentum as the nesting vector produces the commensurate low-frequency response and the coexistence of two spin-excitation branches in Pr 1-x LaCe x CuO 4, while incommensurate nesting vectors in p-type crystals lead to the incommensurate low-frequency response and the hourglass dispersion of susceptibility maxima.
On the benefits of providing versioning support for end users
Authors: Kuttal Sandeep K. , Sarma Anita , Rothermel Gregg
Published: March 2014

End users with little formal programming background are creating software in many different forms, including spreadsheets, web macros, and web mashups. Web mashups are particularly popular because they are relatively easy to create, and because many programming environments that support their creation are available. These programming environments, however, provide no support for tracking versions or provenance of mashups. We believe that versioning support can help end users create, understand, and debug mashups. To investigate this belief, we have added versioning support to a popular wire-oriented mashup environment, Yahoo! Pipes. Our enhanced environment, which we call “Pipes Plumber,” automatically retains versions of pipes and provides an interface with which pipe programmers can browse histories of pipes and retrieve specific versions. We have conducted two studies of this environment: an exploratory study and a larger controlled experiment. Our results provide evidence that versioning helps pipe programmers create and debug mashups. Subsequent qualitative results provide further insights into the barriers faced by pipe programmers, the support for reuse provided by our approach, and the support for debugging provided.
Report on the first Heidelberg Laureate Forum
Authors: White John R.
Published: March 2014

In late 2011, the Klaus Tschira Foundation and the Heidelberg Institute of Theoretical Studies approached ACM, the International Mathematical Union, and the Norwegian Academy of Science and Letters with a proposal for a forum modeled after the Lindau Forum for Nobel Laureates and young researchers. The Lindau meeting brings Nobel Laureates into close contact with young researchers from all over the world. These meetings have taken place for over sixty years, and they are extremely popular among young scientists---and among Nobel laureates as well.
Up close and personal
Authors: Jakobsen Mikkel R. , HornbÆk Kasper
Published: March 2014

Multitouch wall-sized displays afford new forms of collaboration: They can be used up close by several users simultaneously, offer high resolution, and provide sufficient space for intertwining individual and joint work. The difference to displays without these capabilities is not well understood. To better understand the collaboration of groups around high-resolution multitouch wall displays, we conducted an exploratory study. Pairs collaborated on a problem-solving task using a 2.8m × 1.2m multitouch display with 24.8 megapixels. The study examines how participants collaborate; navigate relative to the display and to each other; and interact with and share the display. Participants physically navigated among different parts of the display, switched fluidly between parallel and joint work, and shared the display evenly. The results contrast earlier research that suggests difficulties in sharing and collaborating around wall displays. The study suggests that multitouch wall displays can support different collaboration styles and fluid transitions in group work.
Ubiquity symposium: The science in computer science: the computing sciences and STEM education
Authors: Rosenbloom Paul S.
Published: March 2014

In this latest installment of "The Science in Computer Science," Prof. Paul Rosenbloom continues the discussion on whether or not computer science can be considered a "natural science." He argues not only is computing the basis for a true science, it is in fact an entire scientific domain.
Understanding and addressing real-world accessibility issues in mainstream video games
Authors: Porter John R.
Published: March 2014

Video games have become an important part of various facets of society and culture. However, due to widespread and often critical accessibility issues, many gamers with disabilities are finding themselves cut off from full participation in the world of gaming. Although game accessibility has received a fair amount of interest from our community in recent years, this work lacks adequate consideration of the real-world context of the mainstream gaming. Here, I consider limitations in the existing body of game accessibility research, outline my proposed work as a solution and its contributions to our community, discuss the current status of my research, and state my interest in participation in the ASSETS '13 Doctoral Consortium.
The development of novel eyes-free exercise technologies using participatory design
Authors: Rector Kyle
Published: March 2014

People who are blind or low vision may have a harder time participating in exercise classes due to inaccessibility, travel difficulties, or lack of experience. My dissertation research will attempt to lower the barrier between people who are blind or low-vision and exercising independently. Three new fitness technologies will be developed: Eyes-Free Yoga, Eyes-Free Rock Climbing, and Eyes-Free Track Running. In addition, I plan on collaborating with the visually impaired and those who are involved in their fitness. This will materialize into a focus group and a list of priorities for Eyes-Free Exercise Technology. So far, I have completed Eyes-Free Yoga and completed formative work toward Eyes-Free Rock Climbing. With participatory design and collaboration, I hope to design and develop technologies that will be beneficial for blind and low-vision wellness.