bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the Effect of a Novice Driver Training Program on Citations and Crashes
Authors: Zhang Tingru , Li Jinzheng , Thai Hugh , Zafian Tracy , Samuel Siby , Fisher Donald L.
Published: September 2016

Novice driver training programs have been shown to change behaviors known to be linked to increases in crash risks, behaviors such as long glances inside the vehicle and failures to glance towards latent hazards. However, until recently no program had been shown to change the actual frequency of citations and crashes. The one program that has been shown to reduce crashes was delivered once, at the time of licensure, took only 17 minutes in length to complete, and addressed only hazard anticipation. We asked whether a training program that addressed both hazard anticipation and attention maintenance skills, Distractology 101, was roughly twice as long in length, and was delivered once in person and once over the internet would prove at least as effective, not only with drivers who had just received their license, but also drivers who had up to 36 months of experience. The results showed that this training program reduced citations and crashes significantly and similarly across drivers with different driving experience.
Bayesian Highest Density Intervals of Take-Over Times for Highly Automated Driving in Different Traffic Densities
Authors: Körber Moritz , Radlmayr Jonas , Bengler Klaus
Published: September 2016

Current human factors research on automated driving aims to ensure its safe introduction into road traffic. Although informative results are crucial for this purpose, most studies rely on point estimates and dichotomous reject-nonreject decisions that have been declared obsolete by more recent statistical approaches like new statistics (Cumming, 2014) or Bayesian parameter estimation (Kruschke, 2015). In this work, we show the objective advantages of Bayesian parameter estimation and demonstrate its abundance of information on parameters. In Study 1, we estimate take-over times with a relatively uninformed prior distribution. In Study 2, the resulting posterior distributions of Study 1 were then used as informed prior distributions for interval estimations of mean, standard deviation and distribution shape of take-over time in different traffic densities. We obtained 95 % credible interval widths between 490 ms and 600 ms for mean take-over times, depending on the condition. These intervals include the 95 % most probable values of the mean take-over time and represent a quantification of uncertainty in the estimation. Given the data and the experimental conditions, a take-over requires most likely 2.51 seconds [2.27, 2.76] when there is no traffic, 3.40 seconds [3.11, 3.71] in medium traffic and 3.50 seconds [3.21, 3.78] in high traffic. Bayesian model comparison with Bayes Factor is discussed as an alternative approach in conclusion.
Trust in Automation as a Matter of Media Influence and Experi-ence of Automated Vehicles
Authors: Feldhütter Anna , Gold Christian , Hüger Adrian , Bengler Klaus
Published: September 2016

Highly automated vehicles (HAV), which could help to enhance road safety and efficiency, are very likely to enter the market within the next decades. To have an impact, these systems need to be purchased, which is a matter of trust and acceptance. These factors are dependent on the level of information that one has about such systems. One important source of information is various media, such as newspapers, magazines and videos, in which highly automated driving (HAD) is currently a frequent topic of discussion. To evaluate the influence of media on the perception of HAD, 31 participants were presented with three different types of media addressing HAD in a neutral manner. Afterwards, the participants experienced HAD in the driving simulator. In between these steps, the participants completed questionnaires assessing comfort, trust in automation, increase in safety, intention to use and other factors in order to analyze the effect of the media and the driving simulation experience. Results indicate that the perception of some aspects of HAD were affected by the media presented, while experiencing HAD in the driving simulator generally did not have an effect on the attitude of the participants. Other aspects, such as trust, were not affected by either media or experience. In addition, gender-related differences in the perception of HAD were found.
Repetitive Lifting Tasks in Logistics – Effects on Humans at Different Lifting Task Durations
Authors: Knott Verena C. , Wiest Alexander , Bengler Klaus
Published: September 2016

A volunteer study at the Chair of Ergonomics (TUM) investigates which cardiovascular effects on the human body are to be expected from repetitive lifting movements at different load times, and which requirements arise accordingly with respect to different lifting task durations by using the cardiopulmonary exercise testing (CPET) method. Two different weight classes and three different load times are combined with a conventional lifting task. In addition to the acquisition of objective data, such as oxygen consumption (V’O2/kg) or heart rate (HR), the subjective stress using the Borg RPE scale is determined and analyzed. 27 test persons (M=27.6 years, SD=±3.1) participated in the study. At 70.4% less than three quarter of the participants in the test were men. Both the objective and subjective data show significant differences between the mentioned weight classes. A load time of more than 10 minutes for analyzing manual handling tasks by using CPET is recommended.
Assessing Corporate Perceptions of a Human Factors Lab using Thematic Text Analysis
Authors: Dorton Stephen , Spaulding Ronald , Burton Patrick , Wetzel Angelique
Published: September 2016

To assess and increase the organizational maturity of a new human factors lab in a distributed, multi-disciplinary company, a briefing on lab capabilities, goals, and available resources was given to employees at a business meeting. An open-ended survey question was posed to employees pre- and post-briefing to assess corporate perceptions of the human factors lab. Thematic text analysis was used to assess the overall corporate perception of the lab, as well as any differences in the pre- and post-brief perceptions, and differences in perceptions across both technical and managerial personnel. Three major themes emerged from employee responses (the lab as a corporate mechanism, actions performed by the lab, and technical domains of the lab), which did not differ in prevalence across pre- and post-brief responses. Technical personnel had a larger proportion of their mental model attributed to the actions performed by the lab than did the managerial personnel.
The effects of immersiveness and future VR expectations on subjec-tive-experiences during an educational 360° video
Authors: Rupp Michael A. , Kozachuk James , Michaelis Jessica R. , Odette Katy L. , Smither Janan A. , McConnell Daniel S.
Published: September 2016

Virtual reality may potentially create immersive experiences compelling people to believe they are physically present in a virtual space. This may augment learning by increasing interest in the learning content. However, not all technology is equal. Current devices range from limited devices to next generation technology. At the extremes, devices may distract users from learning content by presenting a sub-optimal learning experience which may be affected by expectations of VR. Participants viewed a 360-degree educational video with the goal of learning as much as possible. Each participant used one of three devices: a smartphone, Google Card-board, or Oculus Rift DK2. Overall, more immersive devices induced greater feelings of presence. However, we failed to support the sub-optimal experience hypothesis. We also found that greater expectations and reported feelings of presence led to less information recalled during the simulation, potentially indicating the novelty of VR experiences may overwhelm learners.
Physical Activity After Stroke Is Associated With Increased Interhemispheric Connectivity of the Dorsal Attention Network
Authors: Veldsman Michele , Churilov Leonid , Werden Emilio , Li Qi , Cumming Toby , Brodtmann Amy
Published: September 2016

Background. Attention is frequently impaired after stroke, and its impairment is associated with poor quality of life. Physical activity benefits attention in healthy populations and has also been associated with recovery after brain injury. Objective. We investigated the relationship between objectively measured daily physical activity, attention network connectivity, and attention task performance after stroke. We hypothesized that increased daily physical activity would be associated with improved attention network function. Methods. Stroke patients (n = 62; mean age = 67 years, SD = 12.6 years) and healthy controls (n = 27; mean age = 68 years, SD = 6 years) underwent cognitive testing and 7 minutes of functional magnetic resonance imaging in the resting-state. Patients were tested 3 months after ischemic stroke. Physical activity was monitored with an electronic armband worn for 7 days. Dorsal and ventral attention network function was examined using seed-based connectivity analyses. Results. Greater daily physical activity was associated with increased interhemispheric connectivity of the superior parietal lobule in the dorsal attention network (DAN; P < .05, false discovery rate corrected). This relationship was not explained by stroke lesion volume. Importantly, stronger connectivity in this region was related to faster reaction time in 3 attention tasks, as revealed by robust linear regression. The relationship remained after adjusting for age, gray matter volume, and white matter hyperintensity load. Conclusions. Daily physical activity was associated with increased resting interhemispheric connectivity of the DAN. Increased connectivity was associated with faster attention performance, suggesting a cognitive correlate to increased network connectivity. Attentional modulation by physical activity represents a key focus for intervention studies.
Usability of Medical Devices for Patients With Diabetes Who Are Visually Impaired or Blind
Authors: Heinemann Lutz , Drossel Diana , Freckmann Guido , Kulzer Bernhard
Published: September 2016

The estimation is that every third to fourth patient with diabetes suffers from some degree of diabetic retinopathy. Medical products for insulin administration (such as insulin pens and pumps) or glucose monitoring not optimized to the needs of these patients’ represent a high barrier for optimal diabetes therapy in daily practice. To date, the number of devices suitable for visually impaired and blind patients with diabetes is scarce. This manuscript outlines the specific needs of this patient group with regard to systems for insulin administration, blood glucose measurement, and continuous glucose monitoring. We see the clear need for a policy requirement for manufacturers to provide accessible/user friendly technical aids for visually impaired and blind patients with diabetes. This would represent an important step toward improving the situation for this impressively large patient group.
Activin and Nodal Are Not Suitable Alternatives to TGFβ for Chondrogenic Differentiation of Mesenchymal Stem Cells
Authors: Kroon Laurie M. G. de , Davidson Esmeralda N. Blaney , Narcisi Roberto , Farrell Eric , Kraan Peter M. van der , van Osch Gerjo J. V. M.
Published: September 2016

Objective

Previously, we demonstrated the importance of transforming growth factor-β (TGFβ)-activated SMAD2/3 signaling in chondrogenesis of bone marrow–derived mesenchymal stem cells (BMSCs). However, TGFβ also signals via the SMAD1/5/9 pathway, which is known to induce terminal differentiation of BMSCs. In this study, we investigated whether other SMAD2/3-activating ligands, Activin and Nodal, can induce chondrogenic differentiation of BMSCs without inducing terminal differentiation.

Design

Activation of SMAD2/3 signaling and chondrogenesis were evaluated in human BMSCs ( N = 3 donors) stimulated with TGFβ, Activin, or Nodal. SMAD2/3 activation was assessed by determining phosphorylated-SMAD2 (pSMAD2) protein levels and SMAD2/3-target gene expression of SERPINE1. Chondrogenesis was determined by ACAN and COL2A1 transcript analysis and histological examination of proteoglycans and collagen type II.

Results

Both Activin and TGFβ enhanced pSMAD2 and SERPINE1 expression compared to the control condition without growth factors, demonstrating activated SMAD2/3 signaling. pSMAD2 and SERPINE1 had a higher level of expression following stimulation with TGFβ than with Activin, while Nodal did not activate SMAD2/3 signaling. Of the 3 ligands tested, only TGFβ induced chondrogenic differentiation as shown by strongly increased transcript levels of ACAN and COL2A1 and positive histological staining of proteoglycans and collagen type II.

Conclusions

Even with concentrations up to 25 times higher than that of TGFβ, Activin and Nodal do not induce chondrogenic differentiation of BMSCs; thus, neither of the 2 ligands is an interesting alternative candidate for TGFβ to induce chondrogenesis without terminal differentiation. To obtain stable cartilage formation by BMSCs, future studies should decipher how TGFβ-induced terminal differentiation can be prevented.
Rifampicin and isoniazid plasma concentrations in relation to adverse reactions in tuberculosis patients: a retrospective analysis
Authors: Aït Moussa L. , El Bouazzi O. , Serragui S. , Soussi Tanani D. , Soulaymani A. , Soulaymani R.
Published: September 2016

Objective:

High concentrations of antituberculosis (anti-TB) drugs can be associated with many adverse drug reactions (ADRs). The objective of this study was to examine the plasma concentrations of rifampicin (RMP) and isoniazid (INH) in patients with and without ADRs.

Methods:

Concentration monitoring data of patients treated with anti-TB drugs were retrospectively analyzed from 2009 to 2011. RMP and INH plasma concentrations were measured 2 and 3 h after drug administration respectively using high-performance liquid chromatography.

Results:

A total of 54 out of 120 patients have experienced ADRs to anti-TB drugs. The median concentrations [interquartile range (IQR)] obtained in patients with and without ADRs were 6.7 mg/l (3.7–9.9) and 5.6 mg/l (2.9–8.6) ( p = 0.56) for RMP and 4.3 mg/l (2.3–5.3) and 3.1 mg/l (1.7–4.8) ( p = 0.04) for INH, respectively. Related median doses (IQR) were 8.7 mg/kg (8.0–10.0) and 8.6 mg/kg (6.5–9.9) ( p = 0.42) for RMP and 4.8 mg/kg (4.3–5.0) and 4.0 mg/kg (2.8–5) ( p < 0.01) for INH, respectively. Concentrations above the expected range in patients with and without ADRs were not reached for RMP, but were 76% and 65% for INH, respectively. Correlation between concentrations and doses has not been established for RMP or INH. In addition, high INH concentrations showed no association with sex, age, liver injury or renal or diabetes.

Conclusions:

High INH concentrations were common in patients with and without ADRs whereas RMP concentrations were low or within the normal range in most patients. Further studies are required to assess the association between high INH concentrations and the occurrence of ADRs.
Effective treatment of benign biliary strictures with a removable, fully covered, self‐expandable metal stent: A prospective, multicenter European study
Authors: Schmidt Arthur , Pickartz Tilman , Lerch Markus M , Fanelli Fabrizio , Fiocca Fausto , Lucatelli Pierleone , Cereatti Fabrizio , Hoffmeister Albrecht , van Steenbergen Werner , Kraft Matthias , Meier Benjamin , Caca Karel
Published: September 2016

Background

Temporary placement of removable, fully covered, self‐expandable metal stents (fcSEMS) for treatment of benign biliary strictures (BBS) has been reported to be effective. However, the optimal extraction time point remains unclear and stent migration has been a major concern.

Objective

The objective of this study was to evaluate the efficacy and safety of this treatment modality using an fcSEMS with a special antimigration design and prolonged stent indwell time.

Methods

We performed a prospective, single‐arm study at six tertiary care centers in Europe. Patients with BBS underwent endoscopic or percutaneous implantation of an fcSEMS (GORE® VIABIL® Biliary Endoprosthesis, W.L. Gore & Associates, Flagstaff, AZ, USA). The devices were scheduled to be removed nine months later, and patients were to return for follow‐up for an additional 15 months.

Results

Forty‐three patients were enrolled in the study. Stricture etiology was chronic pancreatitis in the majority of patients (57.5%). All fcSEMS were placed successfully, either endoscopically (76.7%) or percutaneously (23.3%). Stent migration was observed in two patients (5.2%). Primary patency of the SEMS prior to removal was 73.0%. All attempted stent removals were successful. At removal, stricture was resolved or significantly improved without need for further therapy in 78.9% of patients. Stricture recurrence during a follow‐up of two years post‐implant was observed in two patients.

Conclusions

Temporary placement of the fcSEMS is a feasible, safe and effective treatment for BBS. The design of the device used in this study accounts for very low migration rates and facilitates easy stent retrieval, even after it has been in place for up to 11 months.
Relationship Quality and Alcohol-Related Social Reinforcement During Couples Interaction
Authors: Fairbairn Catharine E. , Testa Maria
Published: September 2016

Individuals who are unhappy in their intimate partnerships are at risk for developing alcohol problems. But little is known about the mechanisms underlying this link. One possibility is that couples with poor relationship quality gain more reinforcement from alcohol in certain contexts—a possibility that has never previously been empirically examined. In the current study, 304 individuals (152 couples) were assigned to receive alcohol (target BAC .08%) or a nonalcoholic beverage. They then engaged in a conflict-resolution interaction with their partners. Videotaped interactions were coded by trained observers. Results revealed a significant interaction between alcohol and relationship quality across multiple measures. Alcohol decreased negative behaviors, decreased negative reciprocity, and enhanced self-reported experience to a greater extent during interactions involving individuals reporting low relationship quality and had comparatively little effect among those reporting high relationship quality. Findings point to a potential mechanism underlying problem drinking among couples with poor relationship quality.
Preferred Compression Speed for Speech and Music and Its Relationship to Sensitivity to Temporal Fine Structure
Authors: Moore Brian C. J. , Sęk Aleksander
Published: September 2016

Multichannel amplitude compression is widely used in hearing aids. The preferred compression speed varies across individuals. Moore (2008) suggested that reduced sensitivity to temporal fine structure (TFS) may be associated with preference for slow compression. This idea was tested using a simulated hearing aid. It was also assessed whether preferences for compression speed depend on the type of stimulus: speech or music. Twenty-two hearing-impaired subjects were tested, and the stimulated hearing aid was fitted individually using the CAM2A method. On each trial, a given segment of speech or music was presented twice. One segment was processed with fast compression and the other with slow compression, and the order was balanced across trials. The subject indicated which segment was preferred and by how much. On average, slow compression was preferred over fast compression, more so for music, but there were distinct individual differences, which were highly correlated for speech and music. Sensitivity to TFS was assessed using the difference limen for frequency at 2000 Hz and by two measures of sensitivity to interaural phase at low frequencies. The results for the difference limens for frequency, but not the measures of sensitivity to interaural phase, supported the suggestion that preference for compression speed is affected by sensitivity to TFS.
Complex-Tone Pitch Discrimination in Listeners With Sensorineural Hearing Loss
Authors: Bianchi Federica , Fereczkowski Michal , Zaar Johannes , Santurette Sébastien , Dau Torsten
Published: September 2016

Physiological studies have shown that noise-induced sensorineural hearing loss (SNHL) enhances the amplitude of envelope coding in auditory-nerve fibers. As pitch coding of unresolved complex tones is assumed to rely on temporal envelope coding mechanisms, this study investigated pitch-discrimination performance in listeners with SNHL. Pitch-discrimination thresholds were obtained for 14 normal-hearing (NH) and 10 hearing-impaired (HI) listeners for sine-phase (SP) and random-phase (RP) complex tones. When all harmonics were unresolved, the HI listeners performed, on average, worse than NH listeners in the RP condition but similarly to NH listeners in the SP condition. The increase in pitch-discrimination performance for the SP relative to the RP condition ( F0DL ratio) was significantly larger in the HI as compared with the NH listeners. Cochlear compression and auditory-filter bandwidths were estimated in the same listeners. The estimated reduction of cochlear compression was significantly correlated with the increase in the F0DL ratio, while no correlation was found with filter bandwidth. The effects of degraded frequency selectivity and loss of compression were considered in a simplified peripheral model as potential factors in envelope enhancement. The model revealed that reducing cochlear compression significantly enhanced the envelope of an unresolved SP complex tone, while not affecting the envelope of a RP complex tone. This envelope enhancement in the SP condition was significantly correlated with the increased pitch-discrimination performance for the SP relative to the RP condition in the HI listeners.
Investigating Differences in Preferred Noise Reduction Strength Among Hearing Aid Users
Authors: Neher Tobias , Wagener Kirsten C.
Published: September 2016

Even though hearing aid (HA) users can respond very differently to noise reduction (NR) processing, knowledge about possible drivers of this variability (and thus ways of addressing it in HA fittings) is sparse. The current study investigated differences in preferred NR strength among HA users. Participants were groups of experienced users with clear preferences (“NR lovers”; N = 14) or dislikes (“NR haters”; N = 13) for strong NR processing, as determined in two earlier studies. Maximally acceptable background noise levels, detection thresholds for speech distortions caused by NR processing, and self-reported “sound personality” traits were considered as candidate measures for explaining group membership. Participants also adjusted the strength of the (binaural coherence-based) NR algorithm to their preferred level. Consistent with previous findings, NR lovers favored stronger processing than NR haters, although there also was some overlap. While maximally acceptable noise levels and detection thresholds for speech distortions tended to be higher for NR lovers than for NR haters, group differences were only marginally significant. No clear group differences were observed in the self-report data. Taken together, these results indicate that preferred NR strength is an individual trait that is fairly stable across time and that is not easily captured by psychoacoustic, audiological, or self-report measures aimed at indexing susceptibility to background noise and processing artifacts. To achieve more personalized NR processing, an effective approach may be to let HA users determine the optimal setting themselves during the fitting process.
Sentence Recognition Prediction for Hearing-impaired Listeners in Stationary and Fluctuation Noise With FADE
Authors: Kollmeier Birger , Schädler Marc René , Warzybok Anna , Meyer Bernd T. , Brand Thomas
Published: September 2016

To characterize the individual patient’s hearing impairment as obtained with the matrix sentence recognition test, a simulation Framework for Auditory Discrimination Experiments (FADE) is extended here using the Attenuation and Distortion (A+D) approach by Plomp as a blueprint for setting the individual processing parameters. FADE has been shown to predict the outcome of both speech recognition tests and psychoacoustic experiments based on simulations using an automatic speech recognition system requiring only few assumptions. It builds on the closed-set matrix sentence recognition test which is advantageous for testing individual speech recognition in a way comparable across languages. Individual predictions of speech recognition thresholds in stationary and in fluctuating noise were derived using the audiogram and an estimate of the internal level uncertainty for modeling the individual Plomp curves fitted to the data with the Attenuation (A-) and Distortion (D-) parameters of the Plomp approach. The “typical” audiogram shapes from Bisgaard et al with or without a “typical” level uncertainty and the individual data were used for individual predictions. As a result, the individualization of the level uncertainty was found to be more important than the exact shape of the individual audiogram to accurately model the outcome of the German Matrix test in stationary or fluctuating noise for listeners with hearing impairment. The prediction accuracy of the individualized approach also outperforms the (modified) Speech Intelligibility Index approach which is based on the individual threshold data only.
Toward a Diagnostic Test for Hidden Hearing Loss
Authors: Plack Christopher J. , Léger Agnès , Prendergast Garreth , Kluk Karolina , Guest Hannah , Munro Kevin J.
Published: September 2016

Cochlear synaptopathy (or hidden hearing loss), due to noise exposure or aging, has been demonstrated in animal models using histological techniques. However, diagnosis of the condition in individual humans is problematic because of (a) test reliability and (b) lack of a gold standard validation measure. Wave I of the transient-evoked auditory brainstem response is a noninvasive electrophysiological measure of auditory nerve function and has been validated in the animal models. However, in humans, Wave I amplitude shows high variability both between and within individuals. The frequency-following response, a sustained evoked potential reflecting synchronous neural activity in the rostral brainstem, is potentially more robust than auditory brainstem response Wave I. However, the frequency-following response is a measure of central activity and may be dependent on individual differences in central processing. Psychophysical measures are also affected by intersubject variability in central processing. Differential measures may help to reduce intersubject variability due to unrelated factors. A measure can be compared, within an individual, between conditions that are affected differently by cochlear synaptopathy. Validation of the metrics is also an issue. Comparisons with animal models, computational modeling, auditory nerve imaging, and human temporal bone histology are all potential options for validation, but there are technical and practical hurdles and difficulties in interpretation. Despite the obstacles, a diagnostic test for hidden hearing loss is a worthwhile goal, with important implications for clinical practice and health surveillance.
Perceptual Spaces Induced by Cochlear Implant All-Polar Stimulation Mode
Authors: Marozeau Jeremy , McKay Colette M.
Published: September 2016

It has been argued that a main limitation of the cochlear implant is the spread of current induced by each electrode, which activates an inappropriately large range of sensory neurons. To reduce this spread, an alternative stimulation mode, the all-polar mode, was tested with five participants. It was designed to activate all the electrodes simultaneously with appropriate current levels and polarities to recruit narrower regions of auditory nerves at specific intracochlear electrode positions (denoted all-polar electrodes). In this study, the all-polar mode was compared with the current commercial stimulation mode: the monopolar mode. The participants were asked to judge the sound dissimilarity between pairs of two-electrode pulse-train stimuli that differed in the electrode positions and were presented in either monopolar or all-polar mode with pulses on the two electrodes presented either sequentially or simultaneously. The dissimilarity ratings were analyzed using a multidimensional scaling technique and three-dimensional stimulus perceptual spaces were produced. For all the conditions (mode and simultaneity), the first perceptual dimension was highly correlated with the position of the most apical activated electrode of the electrical stimulation and the second dimension with the position of the most basal electrode. In both sequential and simultaneous conditions, the monopolar and all-polar stimuli were significantly separated by a third dimension, which may indicate that all-polar stimuli have a perceptual quality that differs from monopolar stimuli. Overall, the results suggest that both modes might successfully represent spectral information in a sound processing strategy.
Aged neutrophils contribute to the first line of defense in the acute inflammatory response
Authors: Uhl Bernd , Vadlau Yannick , Zuchtriegel Gabriele , Nekolla Katharina , Sharaf Kariem , Gaertner Florian , Massberg Steffen , Krombach Fritz , Reichel Christoph A.
Published: September 2016

Key Points

Aged neutrophils exhibit a distinct, highly reactive phenotype that depends on age-related changes in their molecular repertoire. This specific phenotype of aged neutrophils enables them to serve as “first responders” in inflammatory reactions.
Regional tau deposition measured by [18F]THK5317 positron emission tomography is associated to cognition via glucose metabolism in Alzheimer’s disease
Authors: Saint-Aubert Laure , Almkvist Ove , Chiotis Konstantinos , Almeida Rita , Wall Anders , Nordberg Agneta
Published: September 2016

Background

The recent development of tau-specific positron emission tomography (PET) tracers has allowed in vivo quantification of regional tau deposition and offers the opportunity to monitor the progression of tau pathology along with cognitive impairment. In this study, we investigated the relationships of cerebral tau deposition ([18F]THK5317-PET) and metabolism ([18F]FDG-PET) with concomitant cognitive function in patients with probable Alzheimer’s disease (AD).

Methods

Nine patients diagnosed with AD dementia and 11 with prodromal AD (mild cognitive impairment, amyloid-positive on [11C]PiB-PET) were included in this study. All patients underwent PET scans using each tracer, as well as episodic memory and global cognition assessment. Linear models were used to investigate the association of regional [18F]THK5317 retention and [18F]FDG uptake with cognition. The possible mediating effect of local metabolism on the relationship between tau deposition and cognitive performance was investigated using mediation analyses.

Results

Significant negative associations were found between [18F]THK5317 regional retention, mainly in temporal regions, and both episodic memory and global cognition. Significant positive associations were found between [18F]FDG regional uptake and cognition. The association of [18F]FDG with global cognition was regionally more extensive than that of [18F]THK5317, while the opposite was observed with episodic memory, suggesting that [18F]THK5317 retention might be more sensitive than [18F]FDG regional uptake to early cognitive impairment. Finally, [18F]FDG uptake had a mediating effect on the relationship between [18F]THK5317 retention in temporal regions and global cognition.

Conclusions

These findings suggest a mediating role for local glucose metabolism in the observed association between in vivo tau deposition and concomitant cognitive impairment in AD.
Ontology mapping and semantics of web interface signs
Authors: Islam Muhammad Nazrul , Islam A. K. M. Najmul
Published: September 2016

Although, intuitive interface signs are crucial elements of a good user interface (UI), prior research ignored these in UI design and usability evaluation process. This paper argues that ontology (the set of concepts and skills for understanding the referential meaning of an interface sign) mapping is critical for intuitive sign design. An experiment with fourteen participants and twelve signs (total 168 cases) has been carried out. The data has been analysed using both qualitative and quantitative approaches. The findings suggest that ontology mapping is important for understanding the semantics of interface signs. The paper concludes with design implications and future research plan.
An improved high-quality draft genome sequence of Carnobacterium inhibens subsp. inhibens strain K1T
Authors: Nicholson Wayne L. , Davis Christina L. , Shapiro Nicole , Huntemann Marcel , Clum Alicia , Reddy T. B. K. , Pillay Manoj , Markowitz Victor , Varghese Neha , Pati Amrita , Ivanova Natalia , Kyrpides Nikos , Woyke Tanja
Published: September 2016

Despite their ubiquity and their involvement in food spoilage, the genus Carnobacterium remains rather sparsely characterized at the genome level. Carnobacterium inhibens K1T is a member of the Carnobacteriaceae family within the class Bacilli. This strain is a Gram-positive, rod-shaped bacterium isolated from the intestine of an Atlantic salmon. The present study determined the genome sequence and annotation of Carnobacterium inhibens K1T. The genome comprised 2,748,608 bp with a G + C content of 34.85 %, which included 2621 protein-coding genes and 116 RNA genes. The strain contained five contigs corresponding to presumptive plasmids of sizes: 19,036; 24,250; 26,581; 65,272; and 65,904 bp.
Wavefront picking for 3D tomography and full-waveform inversion
Authors: AlTheyab Abdullah , Schuster G. T.
Published: September 2016

We have developed an efficient approach for picking first-break wavefronts on coarsely sampled time slices of 3D shot gathers. Our objective was to compute a smooth initial velocity model for multiscale full-waveform inversion (FWI). Using interactive software, first-break wavefronts were geometrically modeled on time slices with a minimal number of picks. We picked sparse time slices, performed traveltime tomography, and then compared the predicted traveltimes with the data in-between the picked slices. The picking interval was refined with iterations until the errors in traveltime predictions fell within the limits necessary to avoid cycle skipping in early arrivals FWI. This approach was applied to a 3D ocean-bottom-station data set. Our results indicate that wavefront picking has 28% fewer data slices to pick compared with picking traveltimes in shot gathers. In addition, by using sparse time samples for picking, data storage is reduced by 88%, and therefore allows for a faster visualization and quality control of the picks. Our final traveltime tomogram is sufficient as a starting model for early arrival FWI.
Physics-based seismic evaluation method: Evaluating possible seismic moment based on microseismic information due to fluid stimulation
Authors: Mukuhira Yusuke , Asanuma Hiroshi , Ito Takatoshi , Häring Markus O.
Published: September 2016

The forecasting and risk assessment of induced seismicity associated with fluid injection have considerable importance for subsurface energy development. We have developed a seismic evaluation method called the possible seismic moment (PoSeMo) model to assess the potential seismic moment that could be released in the future based on current seismic activity. The PoSeMo model assumes the existence of a representative parameter that can describe the seismic characteristics of a given field. This parameter is defined as the seismic moment density, which quantifies the seismic moment able to be released per rock volume. The rock volume presumed to be in critical condition because of stimulation is defined as the stimulated rock volume. The current stimulation condition for the PoSeMo model can be estimated from the product of these two parameters. The difference between the output of the PoSeMo model and the observed cumulative seismic moment corresponds to the cumulative seismic moment that could be released in the future. This value can be transformed into the possible maximum magnitude that has clear physical meaning and that can be used as feedback on the stimulation operation for seismic hazard assessment. We have applied this model to a microseismic data set from the Basel engineered geothermal system project. We have successfully estimated reasonable values for seismic moment density and stimulated rock volume. The PoSeMo model performed well, and it provided reasonable estimates of seismic moment. The maximum magnitude estimated by the PoSeMo model was almost identical to the largest event that had occurred previously. Thus, it was concluded that the PoSeMo model satisfactorily demonstrated its feasibility as a real-time seismic evaluation method, based on physical parameters derived from microseismic information.
Diffraction imaging method by Mahalanobis-based amplitude damping
Authors: Zhao Jingtao , Peng Suping , Du Wenfeng , Li Xiaoting
Published: September 2016

Clarifying and locating small-scale discontinuities or inhomogeneities in the subsurface, such as faults and collapsed columns, plays a vital role in safe coal mining because these discontinuities or inhomogeneities may destroy the continuity of layers and result in dangerous mining accidents. Diffractions carry key information from these objects and therefore can be used for high-resolution imaging. However, diffracted/scattered waves are much weaker than reflected waves and consequently require separation before being imaged. We have developed a Mahalanobis-based diffraction imaging method by modifying the classic Kirchhoff formula with an exponential function to account for the dynamic differences between reflections and diffractions in the shot domain. The imaging method can automatically account for destroying of reflected waves, constructive stacking of diffracted waves, and strengthening of scattered waves. The method can overcome the difficulties in handling Fresnel apertures, and it is suitable for high-resolution imaging because of the consistency of the waveforms in the shot domain. Although the proposed method in principle requires a good migration velocity model for calculating elementary diffraction traveltimes, it is robust to an inaccurate migration velocity model. Two numerical experiments demonstrate the feasibility of the proposed method in removing reflections and highlighting diffractions, and one field application further confirms its efficiency in resolving masked faults and collapsed columns.
Full-waveform inversion with extrapolated low-frequency data
Authors: Li Yunyue Elita , Demanet Laurent
Published: September 2016

The availability of low-frequency data is an important factor in the success of full-waveform inversion (FWI) in the acoustic regime. The low frequencies help determine the kinematically relevant, low-wavenumber components of the velocity model, which are in turn needed to avoid convergence of FWI to spurious local minima. However, acquiring data less than 2 or 3 Hz from the field is a challenging and expensive task. We have explored the possibility of synthesizing the low frequencies computationally from high-frequency data and used the resulting prediction of the missing data to seed the frequency sweep of FWI. As a signal-processing problem, bandwidth extension is a very nonlinear and delicate operation. In all but the simplest of scenarios, it can only be expected to lead to plausible recovery of the low frequencies, rather than their accurate reconstruction. Even so, it still requires a high-level interpretation of band-limited seismic records into individual events, each of which can be extrapolated to a lower (or higher) frequency band from the nondispersive nature of the wave-propagation model. We have used the phase-tracking method for the event separation task. The fidelity of the resulting extrapolation method is typically higher in phase than in amplitude. To demonstrate the reliability of bandwidth extension in the context of FWI, we first used the low frequencies in the extrapolated band as data substitute, to create the low-wavenumber background velocity model, and then we switched to recorded data in the available band for the rest of the iterations. The resulting method, extrapolated FWI, demonstrated surprising robustness to the inaccuracies in the extrapolated low-frequency data. With two synthetic examples calibrated so that regular FWI needs to be initialized at 1 Hz to avoid local minima, we have determined that FWI based on an extrapolated [1, 5] Hz band, itself generated from data available in the [5, 15] Hz band, can produce reasonable estimations of the low-wavenumber velocity models.
Laboratory evidence for Krauklis-wave resonance in fractures and implications for seismic coda wave analysis
Authors: Shih Pei-Ju Rita , Frehner Marcel
Published: September 2016

Krauklis waves are of major interest because they can lead to resonance effects in fluid-filled fractures. This resonance is marked by seismic signals with a dominant signature frequency, which may reveal fracture-related rock properties. In our laboratory study, we used homogeneous Plexiglas samples containing a single well-defined (i.e., manufactured) fracture. We recorded the signals obtained from propagating ultrasonic P- and S-waves (source frequency: 0.6, 1, and 2.25 MHz) along a sample without a fracture and samples with a fracture with different inclination angles of 30°, 45°, and 60° with respect to the short axis. The experimental results obtained from an incident S-wave confirmed that the presence of the fracture led to resonance effects at frequencies lower than the dominant source frequency, which slowly decayed over time in the recorded seismic coda after the first arrival. The resonance frequency was independent of the fracture orientation and the source frequency. We have interpreted this narrow-banded coda signal as a resonance in the fracture, and the frequency at which this occurred was an intrinsic property of the fracture size and elastic properties. To verify our laboratory results, we used an analytical solution, which provided a relationship between the fracture width, fracture length, resonance frequency, and temporal quality factor (i.e., exponential decay over time). The temporal quality factor obtained from our laboratory data agreed very well with the analytical solution. Hence, we concluded that the observed signature frequency (approximately 0.1 MHz) in the seismic coda was indeed a resonance effect. Finally, we have developed possible applications on the reservoir scale to infer fracture-related properties based on seismic coda analysis.
Prevalence of mental disorders in elderly people: The European MentDis_ICF65+ study
Authors: Andreas Sylke , Schulz Holger , Volkert Jana , Dehoust Maria , Sehner Susanne , Suling Anna , Ausín Berta , Canuto Alessandra , Crawford Mike , Da Ronch Chiara , Grassi Luigi , Hershkovitz Yael , Muñoz Manuel , Quirk Alan , Rotenstein Ora , Santos-Olmo Ana Belén , Shalev Arieh , Strehle Jens , Weber Kerstin , Wegscheider Karl , Wittchen Hans-Ulrich , Härter Martin
Published: September 2016

Background

Except for dementia and depression, little is known about common mental disorders in elderly people.

Aims

To estimate current, 12-month and lifetime prevalence rates of mental disorders in different European and associated countries using a standardised diagnostic interview adapted to measure the cognitive needs of elderly people.

Method

The MentDis_ICF65+ study is based on an age-stratified, random sample of 3142 older men and women (65–84 years) living in selected catchment community areas of participating countries.

Results

One in two individuals had experienced a mental disorder in their lifetime, one in three within the past year and nearly one in four currently had a mental disorder. The most prevalent disorders were anxiety disorders, followed by affective and substance-related disorders.

Conclusions

Compared with previous studies we found substantially higher prevalence rates for most mental disorders. These findings underscore the need for improving diagnostic assessments adapted to the cognitive capacity of elderly people. There is a need to raise awareness of psychosocial problems in elderly people and to deliver high-quality mental health services to these individuals.
Women with bipolar disorder and pregnancy: factors influencing their decision-making
Authors: Dolman Clare , Jones Ian R. , Howard Louise M.
Published: September 2016

Background

Women with bipolar disorder are at increased risk of having a severe episode of illness associated with childbirth.

Aims

To explore the factors that influence the decision-making of women with bipolar disorder regarding pregnancy and childbirth.

Method

Qualitative study with a purposive sample of women with bipolar disorder considering pregnancy, or currently or previously pregnant, supplemented by data from an online forum. Data were analysed using thematic analysis.

Results

Twenty-one women with bipolar disorder from an NHS organisation were interviewed, and data were used from 50 women's comments via the online forum of the UK's national bipolar charity. The centrality of motherhood, social and economic contextual factors, stigma and fear were major themes. Within these themes, new findings included women considering an elective Caesarian section in an attempt to avoid the deleterious effects of a long labour and loss of sleep, or trying to avoid the risks of pregnancy altogether by means of adoption or surrogacy.

Conclusions

This study highlights the information needs of women with bipolar disorder, both pre-conception and when childbearing, and the need for improved training for all health professionals working with women with bipolar disorder of childbearing age to reduce stigmatising attitudes and increase knowledge of the evidence base on treatment in the perinatal period.
Integrated network analysis reveals distinct regulatory roles of transcription factors and microRNAs
Authors: Guo Yu , Alexander Katherine , Clark Andrew G. , Grimson Andrew , Yu Haiyuan
Published: September 2016

Analysis of transcription regulatory networks has revealed many principal features that govern gene expression regulation. MicroRNAs (miRNAs) have emerged as another major class of gene regulators that influence gene expression post-transcriptionally, but there remains a need to assess quantitatively their global roles in gene regulation. Here, we have constructed an integrated gene regulatory network comprised of transcription factors (TFs), miRNAs, and their target genes and analyzed the effect of regulation on target mRNA expression, target protein expression, protein–protein interaction, and disease association. We found that while target genes regulated by the same TFs tend to be co-expressed, co-regulation by miRNAs does not lead to co-expression assessed at either mRNA or protein levels. Analysis of interacting protein pairs in the regulatory network revealed that compared to genes co-regulated by miRNAs, a higher fraction of genes co-regulated by TFs encode proteins in the same complex. Although these results suggest that genes co-regulated by TFs are more functionally related than those co-regulated by miRNAs, genes that share either TF or miRNA regulators are more likely to cause the same disease. Further analysis on the interplay between TFs and miRNAs suggests that TFs tend to regulate intramodule/pathway clusters, while miRNAs tend to regulate intermodule/pathway clusters. These results demonstrate that although TFs and miRNAs both regulate gene expression, they occupy distinct niches in the overall regulatory network within the cell.