julilili42/papers huggingface dataset:
The invariance of surface color representations across illuminant changes in the human cortex
2016-09-01

Color is the brain's estimate of reflectance for a given surface. Reflectance describes how much light a surface reflects at different wavelengths. Since the light reflected from a surface depends on its reflectance and on the spectral power distribution of the incident light, it is impossible to predict surface reflectance directly from the wavelength composition of the reflected light. Despite this computational problem, the human visual system is remarkably accurate at inferring the reflectance – perceived as color – of surfaces across different illuminants. This ability is referred to as color constancy and it is essential for the organism to use color as a cue in object search, recognition, and identification. We devised images of two surfaces presented under three different illuminants using physically realistic rendering methods to study the neural architecture underlying surface color perception. Measuring patterns of fMRI voxel activity elicited by these images, we tested to what extent responses to surface color in various retinotopically mapped areas remained stable across illuminants and which regions encoded illuminant information. We made three important observations: First, patterns of fMRI responses to surface color generalized across illuminants in V1 but not V2, V3, hV4, or VO1. Second, accuracy of illuminant decoding was positively correlated with psychophysically measured color constancy as predicted by the Equivalent Illuminant Model. Third, when fMRI activity was elicited by stimuli that were matched in reflected light but differed in illumination and therefore also differed in perceived surface color, there was a gradient from lower to higher visual areas to distinguish between the two inputs in terms of a difference in surface color rather than illumination. Our results demonstrate that V1 represents chromatic invariances in the stimulus environment (possibly via feedback) whereas downstream visual areas are more biased to link chromatic differences to different surface color percepts. Meeting abstract presented at VSS 2016
Pull-out strength of cemented solidversusfenestrated pedicle screws in osteoporotic vertebrae
2016-09-01

Objectives Cement augmentation of pedicle screws could be used to improve screw stability, especially in osteoporotic vertebrae. However, little is known concerning the influence of different screw types and amount of cement applied. Therefore, the aim of this biomechanical in vitro study was to evaluate the effect of cement augmentation on the screw pull-out force in osteoporotic vertebrae, comparing different pedicle screws (solid and fenestrated) and cement volumes (0 mL, 1 mL or 3 mL). Materials and Methods A total of 54 osteoporotic human cadaver thoracic and lumbar vertebrae were instrumented with pedicle screws (uncemented, solid cemented or fenestrated cemented) and augmented with high-viscosity PMMA cement (0 mL, 1 mL or 3 mL). The insertion torque and bone mineral density were determined. Radiographs and CT scans were undertaken to evaluate cement distribution and cement leakage. Pull-out testing was performed with a material testing machine to measure failure load and stiffness. The paired t-test was used to compare the two screws within each vertebra. Results Mean failure load was significantly greater for fenestrated cemented screws (+622 N; p ⩽ 0.001) and solid cemented screws (+460 N; p ⩽ 0.001) than for uncemented screws. There was no significant difference between the solid and fenestrated cemented screws (p = 0.5). In the lower thoracic vertebrae, 1 mL cement was enough to significantly increase failure load, while 3 mL led to further significant improvement in the upper thoracic, lower thoracic and lumbar regions. Conclusion Conventional, solid pedicle screws augmented with high-viscosity cement provided comparable screw stability in pull-out testing to that of sophisticated and more expensive fenestrated screws. In terms of cement volume, we recommend the use of at least 1 mL in the thoracic and 3 mL in the lumbar spine. Cite this article: C. I. Leichtle, A. Lorenz, S. Rothstock, J. Happel, F. Walter, T. Shiozawa, U. G. Leichtle. Pull-out strength of cemented solid versus fenestrated pedicle screws in osteoporotic vertebrae. Bone Joint Res 2016;5:419–426.
Clinical and laboratory tests for the diagnosis of heparin-induced thrombocytopenia
2016-09-01

Summary A rapid diagnostic work-up is required in patients with suspected heparin-induced thrombocytopenia (HIT). However, diagnosis of HIT is challenging due to a number of practical issues and methodological limitations. Many laboratory tests and a few clinical scoring systems are available but the individual characteristics and the diagnostic accuracy of these are hard to appraise. The 4Ts score is a well evaluated clinical assessment tool with the potential to rule out HIT in many patients. Still, it requires experience and is subject to a relevant inter-observer variability. Immunoassays such as enzyme-linked immunosorbent assays or recently developed rapid assays are able to exclude HIT in a number of patients. But, accuracy of immunoassays differs depending on type of assay, threshold, antibody specificity and even manufacturer. Due to a comparatively low positive predictive value, HIT cannot be confirmed by immunoassays alone. In addition, only some of them are immediately accessible, particularly in small laboratories. While functional assays such as the serotonin release assay (SRA) and the heparin-induced platelet activation assay (HIPA) are considered as gold standard for diagnosis of HIT, they require a highly specialised laboratory. In addition, some of them are not adequately evaluated. In clinical practice, we recommend an integrated diagnostic approach combining not only clinical assessment (the 4Ts score) but immunoassays and functional assays as well. We propose a clear diagnostic algorithm supporting clinical decision-making. Furthermore, we provide an overview of all current laboratory techniques for HIT and discuss diagnostic pathways and strategies to reduce diagnostic errors, and future perspectives.
A Thalamocortical Neural Mass Model of the EEG during NREM Sleep and Its Response to Auditory Stimulation
2016-09-01

Few models exist that accurately reproduce the complex rhythms of the thalamocortical system that are apparent in measured scalp EEG and at the same time, are suitable for large-scale simulations of brain activity. Here, we present a neural mass model of the thalamocortical system during natural non-REM sleep, which is able to generate fast sleep spindles (12-15 Hz), slow oscillations (<1 Hz) and K-complexes, as well as their distinct temporal relations, and response to auditory stimuli. We show that with the inclusion of detailed calcium currents, the thalamic neural mass model is able to generate different firing modes, and validate the model with EEG-data from a recent sleep study in humans, where closed-loop auditory stimulation was applied. The model output relates directly to the EEG, which makes it a useful basis to develop new stimulation protocols.
Optimizing Research Payoff
2016-09-01

In this article, we present a model for determining how total research payoff depends on researchers’ choices of sample sizes, α levels, and other parameters of the research process. The model can be used to quantify various trade-offs inherent in the research process and thus to balance competing goals, such as (a) maximizing both the number of studies carried out and also the statistical power of each study, (b) minimizing the rates of both false positive and false negative findings, and (c) maximizing both replicability and research efficiency. Given certain necessary information about a research area, the model can be used to determine the optimal values of sample size, statistical power, rate of false positives, rate of false negatives, and replicability, such that overall research payoff is maximized. More specifically, the model shows how the optimal values of these quantities depend upon the size and frequency of true effects within the area, as well as the individual payoffs associated with particular study outcomes. The model is particularly relevant within current discussions of how to optimize the productivity of scientific research, because it shows which aspects of a research area must be considered and how these aspects combine to determine total research payoff.
Impella 5.0 as a Second‐Line Mechanical Circulatory Support Strategy After Extracorporeal Life Support
2016-09-01

Abstract The catheter‐based Impella 5.0 left ventricular assist device is a powerful and less invasive alternative for patients in cardiogenic shock. The use as second‐line therapy in patients with precedent extracorporeal life support (ECLS) has not been described before now. We analyzed our experience of consecutive patients treated with this alternative strategy. From April 2014 to December 2014, eight patients had been implanted as a second‐line option after ECLS support. The reason for the change from ECLS to Impella 5.0 was absence of cardiac recovery for primary weaning and complications of ECLS therapy. The mean time of ECLS support prior to Impella implantation was 12 ± 7 days. The implantation of the Impella 5.0/CP was technically successful in all patients, and the ECLS could be explanted in all eight patients who received Impella implantation as a second‐line treatment. The second‐line Impella 5.0 therapy resulted in two patients who turned into left ventricular assist device (LVAD) candidates, two primary weaning candidates, and four patients who died in the setting of sepsis or absent cardiac recovery and contraindications for durable LVAD therapy. Thereby, the overall hospital discharge survival as well as the 180‐day survival was 50% for Impella 5.0 implantations as second‐line procedure after ECLS. The latest follow‐up survival of this second‐line strategy after ECLS was three out of eight, as one patient died after 299 days of LVAD support due to sepsis. The use of Impella 5.0 constitutes a possible second‐line therapeutic option for those patients who do not show cardiac recovery during prolonged ECLS support or suffer from complications of ECLS therapy. This treatment allows additional time for decisions regarding cardiac recovery or indication for durable LVAD therapy.
schoRsch: An R package for analyzing and reporting factorial experiments
2016-09-01

The schoRsch package aims at improving the usability of the open-source software R for researchers in psychology and related disciplines. It provides easy-to-use functions to format the results of typical tests used in psychology and related fields according to the current style guidelines of the American Psychological Association (APA). These and several other convenience functions, allow for efficient data analysis and aim at expediting the workflow when reporting test results in scientific publications.
Black hole solutions in functional extensions of Born-Infeld gravity
2016-09-01

We consider electrovacuum black hole spacetimes in classical extensions of Eddington-inspired Born-Infeld gravity. By rewriting Born-Infeld action as the square root of the determinant of a matrix , we consider the family of models , and study black hole solutions for a power-law family of models labelled by a simple parameter. We show how the innermost structure of the corresponding black holes is modified as compared to their General Relativity counterparts, discussing in which cases a wormhole structure replaces the point-like singularity. We go forward to argue that in such cases a geodesically complete and thus non-singular spacetime is present, despite the existence of curvature divergences at the wormhole throat.
Exploring the wakes of large offshore wind farms
2016-09-01

Offshore meteorological characteristics set specific conditions for the operation of offshore wind farms. One specific feature is low turbulence intensity which on the one hand reduces loads on turbines but on the other hand is the reason for much longer turbine and farm wakes than over land. The German Government is presently funding a research project called WIPAFF (Wind PArk Far Field) which heads for the analysis of properties and impacts of offshore wind park far fields. The focus is on the analysis of wind farm wakes, their interaction among each other and their regional climate impact. This is done by in-situ, extensive aircraft and satellite measurements and by operating meso-scale wind field models and an analytical wind farm model.
Comparison of Different Measurement Techniques and a CFD Simulation in Complex Terrain
2016-09-01

This paper deals with a comparison of data collected by measurements and a simulation for a complex terrain test site in southern Germany. Lidar, met mast, unmanned aerial vehicle (UAV) measurements of wind speed and direction and Computational Fluid Dynamics (CFD) data are compared to each other. The site is characterised regarding its flow features and the suitability for a wind turbine test field. A Delayed-Detached-Eddy- Simulation (DES) was employed using measurement data to generate generic turbulent inflow. A good agreement of the wind profiles between the different approaches was reached. The terrain slope leads to a speed-up, a change of turbulence intensity as well as to flow angle variations.
Correlation between positron emission tomography and Cerenkov luminescence imagingin vivoandex vivousing 64Cu-labeled antibodies in a neuroblastoma mouse model
2016-09-01

Antibody-based therapies gain momentum in clinical therapy, thus the need for accurate imaging modalities with respect to target identification and therapy monitoring are of increasing relevance. Cerenkov luminescence imaging (CLI) are a novel method detecting charged particles emitted during radioactive decay with optical imaging. Here, we compare Position Emission Tomography (PET) with CLI in a multimodal imaging study aiming at the fast and efficient screening of monoclonal antibodies (mAb) designated for targeting of the neuroblastoma-characteristic epitope disialoganglioside GD2. Neuroblastoma-bearing SHO mice were injected with a 64Cu-labeled GD2-specific mAb. The tumor uptake was imaged 3 h, 24 h and 48 h after tracer injection with both, PET and CLI, and was compared to the accumulation in GD2-negative control tumors (human embryonic kidney, HEK-293). In addition to an in vivo PET/CLI-correlation over time, we also demonstrate linear correlations of CLI- and γ-counter-based biodistribution analysis. CLI with its comparably short acquisition time can thus be used as an attractive one-stop-shop modality for the longitudinal monitoring of antibody-based tumor targeting and ex vivo biodistribution.These findings suggest CLI as a reliable alternative for PET and biodistribution studies with respect to fast and high-throughput screenings in subcutaneous tumors traced with radiolabeled antibodies. However, in contrast to PET, CLI is not limited to positron-emitting isotopes and can therefore also be used for the visualization of mAb labeled with therapeutic isotopes like electron emitters.
Development and in vitro characterization of poly(lactide-<em>co</em>-glycolide) microspheres loaded with an antibacterial natural drug for the treatment of long-term bacterial infections
2016-09-01

Biodegradable polymers, especially poly(lactide-<i>co</i>-glycolide) (PLGA), have good biocompatibility and toxicological properties. In combination with active ingredients, a specialized drug delivery system can be generated. The aim of the present study was to develop a drug delivery system consisting of PLGA microspheres loaded with the natural active ingredient totarol, which has several antimicrobial mechanisms. Totarol, isolated from the <i>Podocarpus totara</i> tree, was purified using column chromatography, and the eluate was checked for purity using thin layer chromatography. The spherically shaped microspheres with mean diameters of 147.21±3.45 μm and 131.14±3.69 μm (totarol-loaded and -unloaded microspheres, respectively) were created using the single emulsion evaporation method. Furthermore, the encapsulation efficiency, in a range of 84.72%±6.68% to 92.36%±0.99%, was measured via UV/vis spectroscopy. In a 90-day in vitro drug release study, the release of totarol was investigated by UV/vis spectroscopy as well, showing a release of 53.76%. The toxicity on cells was determined using BJ fibroblasts or Human Embryonic Kidney cells and an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, which showed no influence on the cell growth. The minimal inhibitory concentration was ascertained. A totarol concentration between 64 μg/mL and 128 μg/mL was necessary to inhibit the bacterial growth over a period of 24 hours. Biofilm formation on the surface of totarol-loaded microspheres was determined using transmission electron microscopy. No biofilm formation could be detected, even if the totarol concentration was below the minimal inhibitory concentration. The hemocompatibility investigations on various markers with fresh heparinized blood (1.5 IU/mL) showed that totarol and totarol-loaded microspheres have no influence on different blood parameters. The PLGA microspheres characterized by slow release of totarol and great entrapment efficiency represent a novel drug delivery system, which may be highly beneficial for the long-term therapy of bacterial infections.
The associated beetle fauna ofHohenbergia augustaandVriesea friburgensis(Bromeliaceae) in southern Brazil
2016-09-01

Albertoni, Fabiano F., Steiner, Josefina, Zillikens, Anne (2016): The associated beetle fauna of Hohenbergia augusta and Vriesea friburgensis (Bromeliaceae) in southern Brazil. Journal of Natural History 50: 2917-2939, DOI: 10.1080/00222933.2016.1218079, URL: http://dx.doi.org/10.1080/00222933.2016.1218079
Feature-based attentional influences on the accommodation response
2016-09-01

Accommodation is known as the process by which the vertebrate eye changes optical power to maintain focus on an object as its distance varies. This process is considered as an oculomotor reflex which is controlled by the Edinger-Westphal nucleus. Afferent limb of the neural circuit of accommodation also involves the visual association cortex which is responsible for complex visual processing. It has been shown that visual imagery and concurrent mental activity can modulate accommodative response. In the present study, we investigate possible effects of covert attention on accommodation response. We tested the hypothesis that covertly attending to a moving object could modulate accommodation. We used an autorefractor in a custom made setup to measure the accommodation of the human eyes. The subjects have been instructed to fixate on the center of the infrared camera, while attending to a linearly moving target in their peripheral visual field. They were asked to report the position of the target by pushing a button when it crossed certain markers. We found that the accommodation was significantly altered from the baseline at the moments of focused attention, although there was no displacement of the fixation point. We confirmed that the subjects have not made saccades to the moving target by analyzing the gaze direction. It has been shown extensively that higher cognitive functions of the brain such as visual attention could change the pupil size and dynamics. We provided further evidence that attentional state is reflected in the accommodative response. These findings could shed light on the mechanisms and neural circuits of accommodation and oculomotor system. Moreover, our finding could provide a new behavioral tool to monitor attentional state when pupil dynamics are not reliable. Next steps in this study would be measuring different feature-based attentional effects on multiple accommodative states of the eye. Meeting abstract presented at VSS 2016
Student Characteristics and Behaviours in Childhood Predict Self–reported Health in Middle Adulthood
2016-09-01

We examined how self–reported and teacher–rated student characteristics in primary school were associated with adult self–reported health. A representative sample of Luxembourgish students was assessed in 1968 ( M age = 11.9, SD = 0.6) and 2008 (N = 745; M age = 51.8, SD = 0.6). Self–reported sense of inferiority and pessimism in childhood were negatively related to subjective health and vitality–related quality of life/health in adulthood (rs = −.08 to −.12); teacher–rated studiousness (age 12 years) was positively related to subjective health, healthcare utilization and vitality–related quality of life/health (age 52 years; rs = .13 to .16). After controlling for childhood IQ, parental socio–economic status, educational attainment and sex in multiple regression analyses, most effects of teacher–rated studiousness showed incremental validity beyond the controls. School entitlement, sense of inferiority, impatience and pessimism were positively related to body mass index (rs = .08 to .13). The responsible student scale and teacher–rated studiousness were negatively related to body mass index (rs = −.09 to −.13). The findings demonstrate that childhood characteristics and behaviours are important life–course predictors of key health dimensions beyond childhood IQ and parental socio–economic status. In addition, this narrower level of assessment adds significantly to the empirical body of knowledge on long–term predictors of health outcomes in adulthood. Copyright © 2016 European Association of Personality Psychology.
Learning to Comprehend Foreign‐Accented Speech by Means of Production and Listening Training
2016-09-01

The effects of production and listening training on the subsequent comprehension of foreign‐accented speech were investigated in a training‐test paradigm. During training, German nonnative (L2) and English native (L1) participants listened to a story spoken by a German speaker who replaced all English /θ/s with /t/ (e.g., * teft for theft ) or they produced the story themselves with the t‐substitutes. During test, participants made auditory lexical decisions to English words with t‐substitutes. L2 participants’ reaction times to words from the training were significantly faster after having produced the story than after no training; having listened to the short story also resulted in faster reaction times, but less strongly so. For L1 participants, the facilitatory effect of training did not differ significantly between production and listening training. Thus, only for L2 participants, the effect of accent production for adaptation was superior to accent listening.
Precision performance surgery for CostgreSQL
2016-09-01

We demonstrate how the compilation of SQL expressions into machine code leads to significant query runtime improvements in PostgreSQL 9. Our primary goal is to connect recent research in query code generation with one of the most widely deployed database engines. The approach calls on LLVM to translate arithmetic and filter expressions into native x86 instructions just before SQL query execution begins. We deliberately follow a non-invasive design that does not turn PostgreSQL on its head: interpreted and compiled expression evaluation coexist and both are used to execute the same query. We will bring an enhanced version of PostgreSQL that exhibits notable runtime savings and provides visual insight into exactly where and how execution plans can benefit from SQL expression compilation.