bluuebunny/crossref_metadata_2025 huggingface dataset:
Manufacturing Skill‐biased Wage Inequality, Natural Resources and Institutions
Authors: Torres Nuno , Afonso Óscar , Soares Isabel
Published: October 2016

We use an extensive dataset on occupational wages to measure the manufacturing skill premium and assess, for the first time, the influence of natural resources and institutional quality—in addition to traditional drivers—for advanced and less‐advanced countries and the full sample. The new findings, regarding 21 countries between 1988 and 2008 in the main panel estimations, suggest the premium of advanced countries rises with tertiary enrollment, net foreign direct investment (FDI) and institutional quality, and falls with centralized wage negotiations and geographically diffuse natural resource activities, mainly re‐exportation related. In less‐advanced countries, the premium rises with net FDI, scale effects, centralized wage negotiations and geographically concentrated natural resource activities (absorbing scarce skilled workers), and falls with trade, diffuse natural resource exploration (using mainly unskilled workers) and high‐technology exports, as emerging national low‐end technology industrial exporters may lower skill pay compared with foreign industrial exporters. In the full sample, the premium rises with scale effects, trade, institutional quality and concentrated natural resources, and falls with the relative skilled‐labor supply, centralized wage negotiations and diffuse natural resources. The results account for a wider diversity of situations compared with the previous studies.
Sharing Social Network Data: Differentially Private Estimation of Exponential Family Random-Graph Models
Authors: Karwa Vishesh , Krivitsky Pavel N. , Slavković Aleksandra B.
Published: October 2016

Motivated by a real life problem of sharing social network data that contain sensitive personal information, we propose a novel approach to release and analyse synthetic graphs to protect privacy of individual relationships captured by the social network while maintaining the validity of statistical results. A case-study using a version of the Enron e-mail corpus data set demonstrates the application and usefulness of the proposed techniques in solving the challenging problem of maintaining privacy and supporting open access to network data to ensure reproducibility of existing studies and discovering new scientific insights that can be obtained by analysing such data. We use a simple yet effective randomized response mechanism to generate synthetic networks under ε-edge differential privacy and then use likelihood-based inference for missing data and Markov chain Monte Carlo techniques to fit exponential family random-graph models to the generated synthetic networks.
Cancer patients' effort to return to normal life: a hermeneutic study
Authors: Mardani‐Hamooleh Marjan , Heidari Haydeh
Published: October 2016

Background

The increasing population of patients with cancer highlights the need to develop an understanding of the patients' lived experiences.

Objective

The purpose of our study was to explore the lived experiences of Iranian patients regarding living with cancer.

Methods

A hermeneutic phenomenological study was performed. Twelve patients with cancer were interviewed to understand their lived experiences. We employed the seven‐stage hermeneutical process of data analysis.

Findings

One constitutive pattern ‘cancer patients' effort to return to normal life' and two associated themes, namely ‘pass through limitations and challenges' and ‘emotional and informational support seeking', were identified. ‘Pass through limitations and challenges' had two subcategories: ‘acceptance of reality' and ‘resist cultural taboos'. ‘Emotional and informational support seeking' also had two subcategories: ‘family and friends support' and ‘healthcare providers support'.

Conclusion

The findings present better understanding of the lived experiences of patients with cancer in Iran regarding the phenomena under the study.

Implications for Practice

Nurses have an obligation to educate patients with cancer about anticipated changes in their life.
The Influenza A Virus Non‐structural Protein NS1 Upregulates The Expression of Collagen Triple Helix Repeat Containing 1 Protein
Authors: Zhu C. , Peng G. , Yi W. , Song H. , Liu F. , Liu X.
Published: October 2016

Influenza A virus (IAV) infection induces a strong immune response and regulates the expression of many host proteins. The collagen triple helix repeat containing 1 (CTHRC1) protein is a secreted protein that exhibits increased expression during the viral infection process. However, the regulatory function of IAV on CTHRC1 expression is obscure. In this study, we investigated the effect of IAV on CTHRC1 expression and its regulatory mechanism. A total of 106 serum specimens from healthy people and 80 serum specimens from patients infected with IAV were collected. The CTHRC1 levels in the sera from the IVA patients and healthy individuals were measured using an enzyme‐linked immunosorbent assay (ELISA), and the differences were statistically analysed. A549 cells were infected with the IAV or delNS1 virus. Additionally, A549 cells were cotransfected with a eukaryotic non‐structural NS1 protein gene expression plasmid and the CTHRC1 gene promoter reporter plasmid (pCTHRC1‐Luc), and, the luciferase activities were assessed. The CTHRC1 mRNA and protein expression were detected using reverse transcription–polymerase chain reaction (RT‐PCR) and Western blotting, respectively. The serum CTHRC1 level was significantly higher in the IAV patients than in the healthy individuals. IAV upregulated the CTHRC1 mRNA and protein expression. The non‐structural NS1 protein specifically activated CTHRC1 gene promoter activity and upregulated CTHRC1 mRNA and protein expression. The activation function had a dose‐dependent effect, indicating that influenza virus upregulated CTHRC1 expression through its NS1 protein.
Role of carbohydrate in central fatigue: a systematic review
Authors: Khong T. K. , Selvanayagam V. S. , Sidhu S. K. , Yusof A.
Published: October 2016

Carbohydrate (CHO) depletion is linked to neuromuscular fatigue during exercise. While its role at peripheral level is relatively well understood, less is known about its impact centrally. The aim of this systematic review was to critically analyze the effects of CHO on central fatigue (CF) assessed by various neurophysiological techniques. Four databases were searched using PRISMA guidelines through February 2016. The inclusion criteria were: CHO as intervention against a placebo control, fatigue induced by prolonged exercise and assessed using neurophysiological measures [voluntary activation (VA), superimposed twitch (SIT), M‐wave, electromyography], alongside maximal voluntary contraction (MVC). Seven papers were reviewed, where exercise duration lasted between 115 and 180 min. CHO improved exercise performance in three studies, whereby two of them attributed it to CF via attenuation of VA and SIT reductions, while the other indicated peripheral involvement via attenuation of M‐wave reduction. Although a few studies suggest that CHO attenuates CF, data on its direct effects on neurophysiological outcome measures are limited and mixed. Generally, measures employed in these studies were inadequate to conclude central contribution to fatigue. Factors including the techniques used and the lack of controls render additional confounding factors to make definitive deductions. Future studies should employ consistent techniques and appropriate neurophysiological controls to distinguish CHO effect at central level. The use of pharmacological intervention should be incorporated to elucidate involvement of central mechanisms.
Friends in high places: A dyadic perspective on peer status as predictor of friendship quality and the mediating role of empathy and prosocial behavior
Authors: Meuwese Rosa , Cillessen Antonius H. N. , Güroğlu Berna
Published: October 2016

Friendships and peer status play important roles in the social landscape of adolescents and are related to developmental outcomes. Yet, how peer status is related to friendship quality and what role social skills play in this association remains unclear. In this study, we use Actor–Partner Interdependence (Mediation) Modeling (Ledermann, Macho, & Kenny, 2011) to investigate how two forms of peer status, preference and popularity, are related to positive and negative friendship quality in mid‐adolescence. Results show that adolescents who are friends with more preferred (i.e., likeable) and popular adolescents report higher friendship quality. These partner effects were partially mediated by adolescents’ own prosocial behavior and their friends’ empathy levels. Higher levels of empathy of one's friend and one's own lesser preference for equity explained why adolescents were more satisfied in a friendship with highly preferred (i.e., likeable) adolescents. Interestingly, empathy was not a mediator for the link between friendship quality and popularity. These findings promote a better understanding of the interplay between different levels of social complexity (i.e., individual, dyadic and peer group level) in adolescence.
Differential parenting and children's social understanding
Authors: Pauker Sharon , Perlman Michal , Prime Heather , Jenkins Jennifer M.
Published: October 2016

In the current study, a curvilinear association was examined between differential parenting and children's social understanding as measured using standardized assessments and behavioral observations. Social understanding was comprised of theory‐of‐mind and behavior indicating understanding of others’ minds (i.e., cognitive sensitivity and internal state talk and reasoning during sibling interactions). Data came from a community sample of 372 children (51.6% males; M age = 5.57, SD = 0.77), their younger siblings (M age = 3.14, SD = 0.27), and their mothers who were observed in their homes. We hypothesized that in families with higher levels of differential parenting, both favored and disfavored older siblings would display poorer social understanding, but that disfavored children would be more negatively impacted. Results from a hierarchical regression analysis indicated an inverse linear effect, rather than a curvilinear relationship, between being favored by mother and siblings’ social understanding. Specifically, disfavored older children showed higher levels of social understanding when interacting with their favored younger sibling. This relationship remained significant after controlling for variables such as age, SES, and language. Findings suggest that differential parenting plays a role in children's ability to understand others.
Adherence to secondary antibiotic prophylaxis for patients with rheumatic heart disease diagnosed through screening in Fiji
Authors: Engelman Daniel , Mataika Reapi L. , Kado Joseph H. , Ah Kee Maureen , Donath Susan , Parks Tom , Steer Andrew C.
Published: October 2016

Objectives

Echocardiographic screening for rheumatic heart disease (RHD) can detect subclinical cases; however, adequate adherence to secondary antibiotic prophylaxis (SAP) is required to alter disease outcomes. We aimed to investigate the adherence to SAP among young people with RHD diagnosed through echocardiographic screening in Fiji and to investigate factors associated with adherence.

Methods

Patients diagnosed with RHD through echocardiographic screening in Fiji from 2006 to 2014 were included. Dates of benzathine penicillin G injections were collected from 76 health clinics nationally from December 2011 to December 2014. Adherence was measured using the proportion of days covered (PDC). Multivariate logistic regression analysis was used to identify characteristics associated with any adherence (≥1 injection received) and adequate adherence (PDC ≥0.80).

Results

Of 494 patients, 268 (54%) were female and the median age was 14 years. Overall, 203 (41%) had no injections recorded and just 33 (7%) had adequate adherence. Multivariate logistic regression showed increasing age (OR 0.93 per year, 95% CI 0.87–0.99) and time since diagnosis ≥1.5 years (OR 0.53, 95% CI 0.37–0.79) to be inversely associated with any adherence. Non‐iTaukei ethnicity (OR 2.58, 95%CI 1.04–6.33) and urban residence (OR 3.36, 95% CI 1.54–7.36) were associated with adequate adherence, whereas time since diagnosis ≥1.5 years (OR 0.38, 95%CI 0.17–0.83) was inversely associated with adequate adherence.

Conclusions

Adherence to SAP after screening in Fiji is currently inadequate for individual patient protection or population disease control. Secondary prevention should be strengthened before further screening can be justified.
ABI4 represses the expression of type‐A ARRs to inhibit seed germination in Arabidopsis
Authors: Huang Xiaozhen , Zhang Xiaoyan , Gong Zhizhong , Yang Shuhua , Shi Yiting
Published: October 2016

The plant hormone abscisic acid (ABA) plays a crucial role in regulating seed germination and post‐germination growth. ABSCISIC ACID INSENSITIVE4 (ABI4), an APETALA2 (AP2)‐type transcription factor, is required for the ABA‐mediated inhibition of seed germination. Cytokinins promote seed germination and seedling growth by antagonizing ABA signaling. However, the interaction between ABA and cytokinin signaling during seed germination remains unclear. Here, we report that ABA signaling downregulates Arabidopsis response regulators (ARRs), a class of cytokinin‐inducible genes, during seed germination and cotyledon greening. We found that the application of exogenous ABA repressed the expression of type‐A ARRs in Arabidopsis seeds and seedlings. Among the type‐A ARR family members, the expression of ARR6, ARR7 and ARR15 was upregulated in ABA‐deficient mutants, indicating that the transcriptional inhibition of type‐A ARRs requires the ABA signaling pathway. Single and multiple mutations of these ARRs resulted in increased ABA sensitivity during germination and cotyledon greening; overexpression of ARR7 or ARR15 led to an ABA‐insensitive phenotype. These observations suggest that type‐A ARRs inhibit the ABA response during seed germination and cotyledon greening. Further analysis showed that ABI4 negatively regulated the transcription of ARR6, ARR7 and ARR15 by directly binding to their promoters. Genetic analysis showed that loss‐of‐function mutations of ARR7 and ARR15 partially rescued the ABA insensitivity of abi4‐1. Thus, this study revealed that ABI4 plays a key role in ABA and cytokinin signaling by inhibiting the transcription of type‐A ARRs to inhibit seed germination and cotyledon greening.
Pretreatment leukocyte ratios and concentrations as predictors of outcome in dogs with cutaneous mast cell tumours
Authors: Skor O. , Fuchs‐Baumgartinger A. , Tichy A. , Kleiter M. , Schwendenwein I.
Published: October 2016

Leukocyte ratios correlate with outcome in several human cancers. Little is known about their prognostic significance in mast cell tumour (MCT). The aim of the study was to evaluate the prognostic significance of pretreatment leukocyte concentrations and their ratios in dogs with MCT for survival. Medical records of 92 dogs with MCT were retrospectively reviewed. Tumour diagnosis was made by tumour biopsy or fine‐needle aspirate. Only dogs without prior treatment were included. Eosinophil, lymphocyte, monocyte and neutrophil concentration were obtained by ADVIA 2120™ (Siemens Healthcare, Vienna, Austria). Neutrophil‐to‐eosinophil ratio (NER), lymphocyte‐to‐monocyte ratio (LMR) and neutrophil‐to‐lymphocyte ratio (NLR) were calculated from collected leukocyte concentrations. Relative eosinophil concentration (REC), NER (P < 0.001), NLR (P = 0.001) and LMR (P < 0.001) were significant prognostic factors for outcome in univariate analysis. REC (P = 0.008) and NER (P = 0.001) remained independent predictors of survival in multiple analyses. Leukocyte concentrations and ratios, especially REC and NER may serve as prognostic indicators in MCT.
Risk factors for treatment‐related adverse events in cancer‐bearing dogs receiving piroxicam
Authors: Eichstadt L. R. , Moore G. E. , Childress M. O.
Published: October 2016

Piroxicam has antitumour effects in dogs with cancer, although side effects may limit its use. The purpose of this study was to retrospectively identify factors predisposing cancer‐bearing dogs to adverse events (AEs) following piroxicam therapy. Medical records of dogs presented to the Purdue Veterinary Teaching Hospital between 2005 and 2015 were reviewed, and 137 dogs met the criteria for study inclusion. Toxic effects of piroxicam in these dogs were graded according to an established system. Multivariate logistic regression was used to estimate the extent to which certain factors affected the risk for AEs. Age [odds ratio (OR) 1.250, P = 0.009; 95% confidence interval (CI) 1.057–1.479] and concurrent use of gastroprotectant medications (OR 2.612, P = 0.025; 95% CI 1.127–6.056) significantly increased the risk for gastrointestinal AEs. The results of this study may help inform the risk versus benefit calculation for clinicians considering the use of piroxicam to treat dogs with cancer.
Acetylcholine released by endothelial cells facilitates flow‐mediated dilatation
Authors: Wilson Calum , Lee Matthew D. , McCarron John G.
Published: October 2016

Key points

The endothelium plays a pivotal role in the vascular response to chemical and mechanical stimuli.

The endothelium is exquisitely sensitive to ACh, although the physiological significance of ACh‐induced activation of the endothelium is unknown.

In the present study, we investigated the mechanisms of flow‐mediated endothelial calcium signalling.

Our data establish that flow‐mediated endothelial calcium responses arise from the autocrine action of non‐neuronal ACh released by the endothelium.

Circulating blood generates frictional forces (shear stress) on the walls of blood vessels. These frictional forces critically regulate vascular function. The endothelium senses these frictional forces and, in response, releases various vasodilators that relax smooth muscle cells in a process termed flow‐mediated dilatation. Although some elements of the signalling mechanisms have been identified, precisely how flow is sensed and transduced to cause the release of relaxing factors is poorly understood. By imaging signalling in large areas of the endothelium of intact arteries, we show that the endothelium responds to flow by releasing ACh. Once liberated, ACh acts to trigger calcium release from the internal store in endothelial cells, nitric oxide production and artery relaxation. Flow‐activated release of ACh from the endothelium is non‐vesicular and occurs via organic cation transporters. ACh is generated following mitochondrial production of acetylCoA. Thus, we show ACh is an autocrine signalling molecule released from endothelial cells, and identify a new role for the classical neurotransmitter in endothelial mechanotransduction.
Temperature Rise Within a Mobile Refuge Alternative—Experimental Investigation and Model Validation
Authors: Yan Lincan , Yantek David , Klein Mark , Bissert Peter , Matetic Rudy
Published: October 2016

Mine Safety and Health Administration (MSHA) regulations require underground coal mines to install refuge alternatives (RAs). In the event of a disaster, RAs must be able to provide a breathable air environment for 96 h. The interior environment of an occupied RA, however, may become hot and humid during the 96 h due to miners' metabolic heat and carbon dioxide scrubbing system heat. The internal heat and humidity may result in miners suffering heat stress or even death. To investigate heat and humidity buildup with an occupied RA, the National Institute for Occupational Safety and Health (NIOSH) conducted testing on a training ten-person, tent-type RA in its Safety Research Coal Mine (SRCM) in a test area that was isolated from the mine ventilation system. The test results showed that the average measured air temperature within the RA increased by 11.4 °C (20.5 °F) and the relative humidity approached 90% RH. The test results were used to benchmark a thermal simulation model of the tested RA. The validated thermal simulation model predicted the average air temperature inside the RA at the end of 96 h to within 0.6 °C (1.1 °F) of the measured average air temperature.
Effect of Ambient Temperature and Humidity on Combustion and Emissions of a Spark-Assisted Compression Ignition Engine
Authors: Chang Yan , Mendrea Brandon , Sterniak Jeff , Bohac Stanislav V.
Published: October 2016

Spark-assisted compression ignition (SACI) offers more practical combustion phasing control and a lower pressure rise rate than homogeneous charge compression ignition (HCCI) combustion and improved thermal efficiency and lower NOx emissions than spark ignition (SI) combustion. Any practical passenger car engine, including one that uses SACI in part of its operating range, must be robust to changes in ambient conditions. This study investigates the effects of ambient temperature and humidity on stoichiometric SACI combustion and emissions. It is shown that at the medium speed and load SACI test point selected for this study, increasing ambient air temperature from 20 °C to 41 °C advances combustion phasing, increases maximum pressure rise rate, causes a larger fraction of the charge to be consumed by auto-ignition (and a smaller fraction by flame propagation), and increases NOx. Increasing ambient humidity from 32% to 60% retards combustion phasing, reduces maximum pressure rise rate, increases coefficient of variation (COV) of indicated mean effective pressure (IMEP), reduces NOx, and increases brake-specific fuel consumption (BSFC). These results show that successful implementation of SACI combustion in real-world driving requires a control strategy that compensates for changes in ambient temperature and humidity.
Structural Topology Optimization Through Explicit Boundary Evolution
Authors: Zhang Weisheng , Yang Wanying , Zhou Jianhua , Li Dong , Guo Xu
Published: October 2016

Traditional topology optimization is usually carried out with approaches where structural boundaries are represented in an implicit way. The aim of the present paper is to develop a topology optimization framework where both the shape and topology of a structure can be obtained simultaneously through an explicit boundary description and evolution. To this end, B-spline curves are used to describe the boundaries of moving morphable components (MMCs) or moving morphable voids (MMVs) in the structure and some special techniques are developed to preserve the smoothness of the structural boundary when topological change occurs. Numerical examples show that optimal designs with smooth structural boundaries can be obtained successfully with the use of the proposed approach.
Robotic intrafractional US guidance for liver SABR: System design, beam avoidance, and clinical imaging
Authors: Schlosser Jeffrey , Gong Ren Hui , Bruder Ralf , Schweikard Achim , Jang Sungjune , Henrie John , Kamaya Aya , Koong Albert , Chang Daniel T. , Hristov Dimitre
Published: October 2016

Purpose

To present a system for robotic 4D ultrasound (US) imaging concurrent with radiotherapy beam delivery and estimate the proportion of liver stereotactic ablative body radiotherapy (SABR) cases in which robotic US image guidance can be deployed without interfering with clinically used VMAT beam configurations.

Methods

The image guidance hardware comprises a 4D US machine, an optical tracking system for measuring US probe pose, and a custom‐designed robot for acquiring hands‐free US volumes. In software, a simulation environment incorporating the LINAC, couch, planning CT, and robotic US guidance hardware was developed. Placement of the robotic US hardware was guided by a target visibility map rendered on the CT surface by using the planning CT to simulate US propagation. The visibility map was validated in a prostate phantom and evaluated in patients by capturing live US from imaging positions suggested by the visibility map. In 20 liver SABR patients treated with VMAT, the simulation environment was used to virtually place the robotic hardware and US probe. Imaging targets were either planning target volumes (PTVs, range 5.9–679.5 ml) or gross tumor volumes (GTVs, range 0.9–343.4 ml). Presence or absence of mechanical interference with LINAC, couch, and patient body as well as interferences with treated beams was recorded.

Results

For PTV targets, robotic US guidance without mechanical interference was possible in 80% of the cases and guidance without beam interference was possible in 60% of the cases. For the smaller GTV targets, these proportions were 95% and 85%, respectively. GTV size (1/20), elongated shape (1/20), and depth (1/20) were the main factors limiting the availability of noninterfering imaging positions. The robotic US imaging system was deployed in two liver SABR patients during CT simulation with successful acquisition of 4D US sequences in different imaging positions.

Conclusions

This study indicates that for VMAT liver SABR, robotic US imaging of a relevant internal target may be possible in 85% of the cases while using treatment plans currently deployed in the clinic. With beam replanning to account for the presence of robotic US guidance, intrafractional US may be an option for 95% of the liver SABR cases.
Associated particle neutron elemental imaging in vivo: A feasibility study
Authors: Abel Michael R. , Koltick David S. , Nie Linda H.
Published: October 2016

Purpose

The purpose of this study is to develop a Monte Carlo simulation model for in vivo associated particle neutron elemental imaging (APNEI) and to study the feasibility of using APNEI to determine the iron distribution in a human liver with the defined model.

Methods

The model presented in this study was defined in mcnp by the basic geometry of the human body, the use of D + D source neutrons, iron as the element of interest, an iron‐containing voxel in the liver as the target region, and 2 large germanium detectors anterior and posterior to the trunk of the body. The f8 pulse height tally was employed in mcnp to determine the signal acquired from iron inelastic scatter gamma rays at various iron concentrations in the target liver voxel. Correspondingly, the f4 average flux tally in mcnp was modified by a dose function such that the equivalent dose to the whole liver and the effective dose to the whole body could be estimated and used as the basis for a limiting number of neutron histories which could feasibly allow for the collection of a sufficient volume of data to construct a 2D image of iron distribution in the liver voxel.

Results

Assuming an allowable equivalent dose to the liver of 5 mSv, 143 inelastic scatter iron gamma ray counts (at ∼847 keV) would ideally be registered at the germanium detectors for a 1 cm3 cube‐shaped liver voxel with an iron concentration of 1000 ppm. According to the simulation model, an image of iron distribution in the liver can be constructed with a 1 cm resolution at the level of 1000 ppm iron. Collecting such an image would yield an estimated whole body dose of 0.82 mSv. The mathematical introduction of image uncertainty resulting from source spot diameter and detector timing resolution more closely approximates the result of real world application.

Conclusions

APNEI of certain elements in vivo appears feasible given several timing, sensitivity, and resolution caveats. However, further study is required to determine what the detection limit of iron would be and what image resolution would be in an experimental setup as the present model contains idealized assumptions which overestimate the signal attributable to iron inelastic scatter gamma rays.
Measuring time-frequency importance functions of speech with bubble noise
Authors: Mandel Michael I. , Yoho Sarah E. , Healy Eric W.
Published: October 2016

Listeners can reliably perceive speech in noisy conditions, but it is not well understood what specific features of speech they use to do this. This paper introduces a data-driven framework to identify the time-frequency locations of these features. Using the same speech utterance mixed with many different noise instances, the framework is able to compute the importance of each time-frequency point in the utterance to its intelligibility. The mixtures have approximately the same global signal-to-noise ratio at each frequency, but very different recognition rates. The difference between these intelligible vs unintelligible mixtures is the alignment between the speech and spectro-temporally modulated noise, providing different combinations of “glimpses” of speech in each mixture. The current results reveal the locations of these important noise-robust phonetic features in a restricted set of syllables. Classification models trained to predict whether individual mixtures are intelligible based on the location of these glimpses can generalize to new conditions, successfully predicting the intelligibility of novel mixtures. They are able to generalize to novel noise instances, novel productions of the same word by the same talker, novel utterances of the same word spoken by different talkers, and, to some extent, novel consonants.
Fluid pressure diffusion effects on the seismic reflectivity of a single fracture
Authors: Barbosa Nicolás D. , Rubino J. Germán , Caspari Eva , Milani Marco , Holliger Klaus
Published: October 2016

When seismic waves travel through a fluid-saturated porous medium containing a fracture, fluid pressure gradients are induced between the compliant fracture and the stiffer embedding background. The resulting equilibration through fluid pressure diffusion (FPD) produces a frequency dependence of the stiffening effect of the fluid saturating the fracture. As the reflectivity of a fracture is mainly controlled by the stiffness contrast with respect to the background, these frequency-dependent effects are expected to affect the fracture reflectivity. The present work explores the P- and S-wave reflectivity of a fracture modeled as a thin porous layer separating two half-spaces. Assuming planar wave propagation and P-wave incidence, this article analyzes the FPD effects on the reflection coefficients through comparisons with a low-frequency approximation of the underlying poroelastic model and an elastic model based on Gassmann's equations. The results indicate that, while the impact of global flow on fracture reflectivity is rather small, FPD effects can be significant, especially for P-waves and low incidence angles. These effects get particularly strong for very thin and compliant, liquid-saturated fractures and embedded in a high-permeability background. In particular, this study suggests that in common environments and typical seismic experiments FPD effects can significantly increase the seismic visibility of fractures.
Comparison of perception-production vowel spaces for speakers of Standard Modern Greek and two regional dialects
Authors: Lengeris Angelos
Published: October 2016

This study compared the perception-production vowel spaces for speakers of Standard Modern Greek and two regional dialects. In experiment 1, participants produced the Greek vowels and chose vowel best exemplars (prototypes) in a natural sentence spoken in the participants' dialect. In experiment 2, the speakers who had made the recordings for experiment 1 chose themselves vowel prototypes. Cross-dialectal differences were found in both perception and production. Across dialects and experiments, participants' perceptual space was exaggerated compared to the acoustic one. Because participants' perceptual space in experiment 2 was calibrated to the participants own voice, perception and production data are directly comparable.
Spectral dynamics of sibilant fricatives are contrastive and language specific
Authors: Reidy Patrick F.
Published: October 2016

Previous research has extensively investigated the spectral properties of sibilant fricatives with little consideration to how these properties vary over time. To investigate such spectro-temporal variation, productions of English /s/ and /ʃ/ and of Japanese /s/ and /ɕ/ in word-initial, prevocalic position were elicited from adult native speakers. The spectral dynamics of these productions were analyzed in terms of a psychoacoustic measure of peak frequency: “peak ERBN number.” Peak ERBN number was computed at 17 evenly spaced points across each fricative production. The resulting peak ERBN number trajectories were analyzed with orthogonal polynomial growth-curve models, to determine how peak frequency varied temporally within each fricative. Three analyses compared (1) the English sibilants to each other, (2) the Japanese sibilants to each other, and (3) English /s/ to Japanese /s/. The results indicated that, in both English and Japanese, the sibilant fricatives differ acoustically in terms of both static (i.e., overall level) and dynamic (i.e., shape) aspects of the peak ERBN number trajectories. Furthermore, English /s/ and Japanese /s/ exhibited language-specific differences in the shape, but not overall level, of peak ERBN number trajectories.
Data-based depth estimation of an incoming autonomous underwater vehicle
Authors: Yang T. C. , Xu Wen
Published: October 2016

The data-based method for estimating the depth of a moving source is demonstrated experimentally for an incoming autonomous underwater vehicle traveling toward a vertical line array (VLA) of receivers at constant speed/depth. The method assumes no information on the sound-speed and bottom profile. Performing a wavenumber analysis of a narrowband signal for each hydrophone, the energy of the (modal) spectral peaks as a function of the receiver depth is used to estimate the depth of the source, traveling within the depth span of the VLA. This paper reviews the theory, discusses practical implementation issues, and presents the data analysis results.
The Effect of Dietary Nitrate Supplementation on Physiology and Performance in Trained Cyclists
Authors: McQuillan Joseph A. , Dulson Deborah K. , Laursen Paul B. , Kilding Andrew E.
Published: October 2016

Purpose:

To determine the effect of dietary nitrate (NO3 –) supplementation on physiology and performance in well-trained cyclists after 6–8 d of NO3 – supplementation.

Methods:

Eight competitive male cyclists (mean ± SD age 26 ± 8 y, body mass 76.7 ± 6.9 kg, VO2peak 63 ± 4 mL · kg–1 · min–1) participated in a double-blind, placebo-controlled, crossover-design study in which participants ingested 70 mL of beetroot juice containing ~4 mmol NO3 – (NIT) or a NO3 –-depleted placebo (PLA), each for 8 d. Replicating pretreatment measures, participants undertook an incremental ramp assessment to determine VO2peak and first (VT1) and second (VT2) ventilatory thresholds on d 6 (NIT6 and PLA6), moderate-intensity cycling economy on d 7 (NIT7 and PLA7), and a 4-km time trial (TT) on d 8 (NIT8 and PLA8).

Results:

Relative to PLA, 6 d of NIT supplementation produced unclear effects for VO2peak (mean ± 95% confidence limit: 1.8% ± 5.5%) and VT1 (3.7% ± 12.3%) and trivial effects for both VT2 (–1.0% ± 3.0%) and exercise economy on d 7 (–1.0% ± 1.6%). However, effects for TT performance time (–0.7% ± 0.9%) and power (2.4% ± 2.5%) on d 8 were likely beneficial.

Conclusions:

Despite mostly unclear outcomes for standard physiological determinants of performance, 8 d of NO3 – supplementation resulted in likely beneficial improvements to 4-km TT performance in well-trained male endurance cyclists.
Unpacking the Black Box: Applications and Considerations for Using GPS Devices in Sport
Authors: Malone James J. , Lovell Ric , Varley Matthew C. , Coutts Aaron J.
Published: October 2016

Athlete-tracking devices that include global positioning system (GPS) and microelectrical mechanical system (MEMS) components are now commonplace in sport research and practice. These devices provide large amounts of data that are used to inform decision making on athlete training and performance. However, the data obtained from these devices are often provided without clear explanation of how these metrics are obtained. At present, there is no clear consensus regarding how these data should be handled and reported in a sport context. Therefore, the aim of this review was to examine the factors that affect the data produced by these athlete-tracking devices and to provide guidelines for collecting, processing, and reporting of data. Many factors including device sampling rate, positioning and fitting of devices, satellite signal, and data-filtering methods can affect the measures obtained from GPS and MEMS devices. Therefore researchers are encouraged to report device brand/model, sampling frequency, number of satellites, horizontal dilution of precision, and software/firmware versions in any published research. In addition, details of inclusion/exclusion criteria for data obtained from these devices are also recommended. Considerations for the application of speed zones to evaluate the magnitude and distribution of different locomotor activities recorded by GPS are also presented, alongside recommendations for both industry practice and future research directions. Through a standard approach to data collection and procedure reporting, researchers and practitioners will be able to make more confident comparisons from their data, which will improve the understanding and impact these devices can have on athlete performance.
Validity of 10-HZ GPS and Timing Gates for Assessing Maximum Velocity in Professional Rugby Union Players
Authors: Roe Gregory , Darrall-Jones Joshua , Black Christopher , Shaw William , Till Kevin , Jones Ben
Published: October 2016

Purpose:

The purpose of this study was to investigate the validity of timing gates and 10-Hz global positioning systems (GPS) units (Catapult Optimeye S5) against a criterion measure (50-Hz radar gun) for assessing maximum sprint velocity (Vmax).

Methods:

Nine male professional rugby union players performed 3 maximal 40-m sprints with 3 min rest between efforts with Vmax assessed simultaneously via timing gates, 10-Hz GPSOpen (Openfield software), GPSSprint (Sprint software), and radar gun. Eight players wore 3 GPS units, while 1 wore a single unit during each sprint.

Results:

When compared with the radar gun, mean biases for GPSOpen, GPSSprint, and timing gates were trivial, small, and small, respectively. The typical error of the estimate (TEE) was small for timing gate and GPSOpen while moderate for GPSSprint. Correlations with radar gun were nearly perfect for all measures. Mean bias, TEE, and correlations between GPS units were trivial, small, and nearly perfect, respectively, while a small TEE existed when GPSOpenfield was compared with GPSSprint.

Conclusion:

Based on these findings, both 10-Hz GPS and timing gates provide valid measures of 40-m Vmax assessment compared with a radar gun. However, as error did exist between measures, the same testing protocol should be used when assessing 40-m Vmax over time. Furthermore, in light of the above results, it is recommended that when assessing changes in GPS-derived Vmax over time, practitioners should use the same unit for each player and perform the analysis with the same software, preferably Catapult Openfield.
Two Training-Load Paradoxes: Can We Work Harder and Smarter, Can Physical Preparation and Medical Be Teammates?
Authors: Gabbett Tim J. , Whiteley Rod
Published: October 2016

The authors have observed that in professional sporting organizations the staff responsible for physical preparation and medical care typically practice in relative isolation and display tension as regards their attitudes toward training-load prescription (much more and much less training, respectively). Recent evidence shows that relatively high chronic training loads, when they are appropriately reached, are associated with reduced injury risk and better performance. Understanding this link between performance and training loads removes this tension but requires a better understanding of the relationship between the acute:chronic workload ratio (ACWR) and its association with performance and injury. However, there remain many questions in the area of ACWR, and we are likely at an early stage of our understanding of these parameters and their interrelationships. This opinion paper explores these themes and makes recommendations for improving performance through better synergies in support-staff approaches. Furthermore, aspects of the ACWR that remain to be clarified—the role of shared decision making, risk:benefit estimation, and clearer accountability—are discussed.
Assessing the Measurement Sensitivity and Diagnostic Characteristics of Athlete-Monitoring Tools in National Swimmers
Authors: Crowcroft Stephen , McCleave Erin , Slattery Katie , Coutts Aaron J.
Published: October 2016

Purpose:

To assess measurement sensitivity and diagnostic characteristics of athlete-monitoring tools to identify performance change.

Methods:

Fourteen nationally competitive swimmers (11 male, 3 female; age 21.2 ± 3.2 y) recorded daily monitoring over 15 mo. The self-report group (n = 7) reported general health, energy levels, motivation, stress, recovery, soreness, and wellness. The combined group (n = 7) recorded sleep quality, perceived fatigue, total quality recovery (TQR), and heart-rate variability. The week-to-week change in mean weekly values was presented as coefficient of variance (CV%). Reliability was assessed on 3 occasions and expressed as the typical error CV%. Week-to-week change was divided by the reliability of each measure to calculate the signal-to-noise ratio. The diagnostic characteristics for both groups were assessed with receiver-operating-curve analysis, where area under the curve (AUC), Youden index, sensitivity, and specificity of measures were reported. A minimum AUC of .70 and lower confidence interval (CI) >.50 classified a “good” diagnostic tool to assess performance change.

Results:

Week-to-week variability was greater than reliability for soreness (3.1), general health (3.0), wellness% (2.0), motivation (1.6), sleep (2.6), TQR (1.8), fatigue (1.4), R-R interval (2.5), and LnRMSSD:RR (1.3). Only general health was a “good” diagnostic tool to assess decreased performance (AUC –.70, 95% CI, .61–.80).

Conclusion:

Many monitoring variables are sensitive to changes in fitness and fatigue. However, no single monitoring variable could discriminate performance change. As such the use of a multidimensional system that may be able to better account for variations in fitness and fatigue should be considered.
Lower Extremity Joint Work During Acceleration, Deceleration, and Steady State Running
Authors: Williams D.S. Blaise , Cole Jonathan H. , Powell Douglas W.
Published: October 2016

Running during sports and for physical activity often requires changes in velocity through acceleration and deceleration. While it is clear that lower extremity biomechanics vary during these accelerations and decelerations, the work requirements of the individual joints are not well understood. The purpose of this investigation was to measure the sagittal plane mechanical work of the individual lower extremity joints during acceleration, deceleration, and steady-state running. Ten runners were compared during acceleration, deceleration, and steady-state running using three-dimensional kinematics and kinetics measures. Total positive and negative joint work, and relative joint contributions to total work were compared between conditions. Total positive work progressively increased from deceleration to acceleration. This was due to greater ankle joint work during acceleration. While there was no significant change in total negative work during deceleration, there was a greater relative contribution of the knee to total negative work with a subsequent lower relative ankle negative work. Each lower extremity joint exhibits distinct functional roles in acceleration compared with deceleration during level running. Deceleration is dominated by greater contributions of the knee to negative work while acceleration is associated with a greater ankle contribution to positive work.
Individual Leg Muscle Contributions to the Cost of Walking: Effects of Age and Walking Speed
Authors: Pincheira Patricio A. , Stenroth Lauri , Avela Janne , Cronin Neil J.
Published: October 2016

This study examined the contributions of individual muscles to changes in energetic cost of transport (COT) over seven walking speeds, and compared results between healthy young and elderly subjects. Twenty six participants (13 young aged 18–30; 13 old aged 70–80) were recruited. COT (O2/kg body mass/km) was calculated by standardizing the mean oxygen consumption recorded during steady state walking. Electromyography signals from 10 leg muscles were used to calculate the cumulative activity required to traverse a unit of distance (CMAPD) for each muscle at each speed. In the old group CMAPD was correlated with COT, presented higher and more variable values, and showed greater increases around optimal speed for all studied muscles. Soleus CMAPD was independent of speed in the young group, but this was not evident with aging. Greater energy cost of walking in older individuals seems to be attributable to increased energy cost of all lower limb muscles.
He Dies, He Scores: Evidence That Reminders of Death Motivate Improved Performance in Basketball
Authors: Zestcott Colin A. , Lifshin Uri , Helm Peter , Greenberg Jeff
Published: October 2016

This research applied insights from terror management theory (TMT; Greenberg, Pyszczynski, & Solomon, 1986) to the world of sport. According to TMT, self-esteem buffers against the potential for death anxiety. Because sport allows people to attain self-esteem, reminders of death may improve performance in sport. In Study 1, a mortality salience induction led to improved performance in a “one-on-one” basketball game. In Study 2, a subtle death prime led to higher scores on a basketball shooting task, which was associated with increased task-related self-esteem. These results may promote our understanding of sport and provide a novel potential way to improve athletic performance.
Transfer of Training After an Organizational Intervention in Swedish Sports Clubs: A Self-Determination Theory Perspective
Authors: Stenling Andreas , Tafvelin Susanne
Published: October 2016

Leadership development programs are common in sports, but seldom evaluated; hence, we have limited knowledge about what the participants actually learn and the impact these programs have on sports clubs’ daily operations. The purpose of the current study was to integrate a transfer of training model with self-determination theory to understand predictors of learning and training transfer, following a leadership development program among organizational leaders in Swedish sports clubs. Bayesian multilevel path analysis showed that autonomous motivation and an autonomy-supportive implementation of the program positively predicted near transfer (i.e., immediately after the training program) and that perceiving an autonomy-supportive climate in the sports club positively predicted far transfer (i.e., 1 year after the training program). This study extends previous research by integrating a transfer of training model with self-determination theory and identified important motivational factors that predict near and far training transfer.