331 research outputs found
Coherence and phase locking of intracerebral activation during visuo- and audio-motor learning of continuous tracking movements
The aim of the present study was to assess changes in EEG coherence and phase locking between fronto-parietal areas, including the frontal and parietal motor areas, during early audio- and visuo-motor learning of continuous tracking movements. Subjects learned to turn a steering-wheel according to a given trajectory in order to minimise the discrepancy between a changing foreground stimulus (controllable by the subjects) and a constant background stimulus (uncontrollable) for both the auditory and the visual modality. In the auditory condition, we uncovered a learning-related increase in inter-hemispheric phase locking between inferior parietal regions, suggesting that coupling between areas involved in audiomotor integration is augmented during early learning stages. Intra-hemispheric phase locking between motor and superior parietal areas increased in the left hemisphere as learning progressed, indicative of integrative processes of spatial information and movement execution. Further tests show a significant correlation of intra-hemispheric phase locking between the motor and the parietal area bilaterally and movement performance in the visual condition. These results suggest that the motor-parietal network is operative in the auditory and in the visual condition. This study confirms that a complex fronto-parietal network subserves learning of a new movement that requires sensorimotor transformation and demonstrates the importance of interregional coupling as a neural correlate for successful acquisition and implementation of externally guided behaviou
Preliminary Investigation of Continuous Self-Improvement, Confidence, & Resilience
https://fuse.franklin.edu/ss2018/1039/thumbnail.jp
The effects of practice distribution upon the regional oscillatory activity in visuomotor learning.
RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: The aim of this study was to investigate the effects of a massed compared to a distributed practice upon visuomotor learning as well as upon the regional oscillatory activity in the sensorimotor cortex. METHODS: A continuous visuomotor tracking task was used to assess visuomotor learning; the underlying neuronal correlates were measured by means of EEG. The massed practice group completed a continuous training of 60 minutes, while the distributed practice group completed four 15 minutes practice blocks separated by rest intervals. RESULTS: While the massed and the distributed practice group did not differ in performance, effects of practice distribution were evident in the regional oscillatory activity. In the course of practice, the massed training group showed a higher task-related theta power and a strong task-related power decrease in the upper alpha frequency over the sensorimotor cortex compared to the distributed practice group. CONCLUSIONS: These differences in the regional oscillatory activity indicate a higher cognitive effort and higher attention demands in the massed practice group. The results of this study support the hypothesis, that a distributed practice is superior to a massed practice in visuomotor learning
Influence of Weathering on Pore Size Distribution of Soft Rocks
Soft rocks can weather and lose their structure within a short time due to drying out and rewetting. Thus they are very sensitive to weathering. Since these rocks are often found in the shallow subsurface, they are of great practical relevance in the foundation of constructions. The rock properties change during the weathering process. Particularly relevant is the softening of the material and the decrease of its mechanical properties, which are determined typically using mechanical laboratory or field tests. The objective of this study is to examine in more detail how the microstructure of rocks changes over the course of weathering, which results in a decrease in mechanical properties. Sulfate rocks of the Grabfeld-Formation in Stuttgart, Germany were investigated. Using XRD analyses it was revealed that initially a chemical weathering processes occurs whereby the rocks leach out, followed by a physical weathering process. Investigations with a mercury porosimeter showed that during chemical weathering the intraaggregate pore content greatly increases, whereas the proportion of interaggregate pores only slightly increases
Fucus distichus: Investigating Humidity and Temperature Between Tides
Environmental elements such as changing rapidly changing temperature, prolonged periods of low to no water exposure, desiccation, predation and increased wave action can influence the diversity of microhabitats that inhabit the littoral zones. When making observations of various shorelines, specifically the physical conditions of the surrounding marine vegetation (i.e. Fucus distichus), an inquiry is made as to the role of Fucus in the amelioration of stressors on the marine habitat during low tide (MLLW), however, due to time considerations, temperature and humidity are the focus of this study. Using temperature and humidity probes, monitoring data shows that Fucus provides relatively humid and cooler conditions for organisms residing beneath the canopy during low tide. Varied weather during the experimental trials allows for monitoring during cool, overcast, and sunny days, allowing for evaluation of Fucus distichus\u27 efficacy in innate conditions. Further investigation, requiring warmer conditions and additional replicates are needed to fully assess the ability of Fucus to moderate environmental conditions beneath its canopy
Coherent intracerebral brain oscillations during learned continuous tracking movements
The aim of the present study was to assess changes in electroencephalogram (EEG) phase locking between fronto-parietal areas, including the frontal and parietal motor areas, during audiomotor learning of continuous tracking movements. Subjects learned to turn a steering wheel according to a given trajectory in order to minimise the discrepancy between a changing foreground stimulus (controllable by the subjects) and a constant background stimulus. The results of the present study show that increasing practice of continuous tracking movements that are continuously performed in the presence of auditory feedback is not accompanied by decrease in phase locking between areas involved. Moreover, the study confirms that internally produced movements show enhanced coherent activities compared to externally guided movements and therefore suggests that the motor-parietal network is more engaged during internally produced than externally produced movement
Implementation of a dermatoscopy curriculum during residency at Augsburg University Hospital in Germany
Background and objectives
To date, there is no structured program for dermatoscopy training during residency in Germany. Whether and how much dermatoscopy training is acquired is left to the initiative of each resident, although dermatoscopy is one of the core competencies of dermatological training and daily practice. The aim of the study was to establish a structured dermatoscopy curriculum during residency at the University Hospital Augsburg.
Patients and methods
An online platform with dermatoscopy modules was created, accessible regardless of time and place. Practical skills were acquired under the personal guidance of a dermatoscopy expert. Participants were tested on their level of knowledge before and after completing the modules. Test scores on management decisions and correct dermatoscopic diagnosis were analyzed.
Results
Results of 28 participants showed improvements in management decisions from pre- to posttest (74.0% vs. 89.4%) and in dermatoscopic accuracy (65.0% vs. 85.6%). Pre- vs. posttest differences in test score (7.05/10 vs. 8.94/10 points) and correct diagnosis were significant (p < 0.001).
Conclusions
The dermatoscopy curriculum increases the number of correct management decisions and dermatoscopy diagnoses. This will result in more skin cancers being detected, and fewer benign lesions being excised. The curriculum can be offered to other dermatology training centers and medical professionals
Reducing the manual length setting error of a passive Gough-Stewart platform for surgical template fabrication using a digital measurement system
As recently demonstrated, a passive Gough-Stewart platform (a.k.a. hexapod) can be used to create a personalized surgical template to achieve minimally invasive access to the cochlea. The legs of the hexapod are manually adjusted to the desired length, which must be read off an analog scale. Previous experiments have shown that manual length setting of the hexapod's legs is error-prone because of the imprecise readability of the analog scale. The objective of this study is to determine if integration of a linear encoder and digitally displaying the measured length help reduce the length setting error. Two experiments were conducted where users set the leg length manually. In both experiments, the users were asked to set the leg length to 20 nominal values using the whole setting range from 0 mm to 10 mm. In the first experiment, users had to rely only on the analog scale; in the second experiment, the electronic display additionally showed the user the actual leg length. Results show that the mean length setting error without using the digital display and only relying on the analog scale was (0.036 ± 0.020) mm (max: 0.107 mm) in contrast to (0.001 ± 0.000) mm (max: 0.002 mm) for the experiment with the integrated digital measurement system. The results support integration of digital length measurement systems as a promising tool to increase the accuracy of surgical template fabrication and thereby patients' safety. Future studies must be conducted to evaluate if integration of a linear encoder in each of the six legs is feasible
Effects of broccoli extract and various essential oils on intestinal and faecal microflora and on xenobiotic enzymes and the antioxidant system of piglets
Objective: Since the ban of antibiotics as growth promoting feed additives in
the EU in 2006 research in alternatives has gained importance. Phytogenic feed
additives represent a heterogenous class of different plant derived substances
that are discussed to improve the health of farm animals by direct and
indirect antioxidant effects and by influencing microbial eubiosis in the
gastrointestinal tract. Consequently our study aimed to investigate the
influence of broccoli extract and the essential oils of tur- meric, oregano,
thyme and rosemary, as selected individual additives, on intestinal and faecal
microflora, on xenobiotic enzymes, and on the antioxidant system of piglets.
Methods: 48 four weeks old male weaned piglets were assigned to 6 groups of 8.
The piglets were housed individually in stainless steel pens with slatted
floor. The control group (Con) was fed a diet without an additive for 4 weeks.
The diet of group BE contained 0.15 g/kg sulforaphane in form of a broccoli
extract. 535, 282, 373 and 476 mg/kg of the essential oils of turmeric (Cuo),
oregano (Oo), thyme (To) and rosemary (Ro) were added to the diets of the
remaining 4 groups to stan-dardise supplementation to 150 mg/kg of the oils’
key terpene compounds ar-turmerone, carvacrol, thymol and 1,8-cineole. The
composition of bacterial microflora was examined by cultivating samples of
jejeunal and colonic mucosa and of faeces under specific conditions. The mRNA
expression of xenobiotic and antioxidant enzymes was determined by reversing
transcrip- tase real time detection PCR (RT-PCR). Total antioxidant status was
assayed using the Trolox Equivalent Antioxidant Capacity (TEAC), and lipid
peroxidation was determined by measuring thiobarbioturic acid reactive
substances (TBA- RS). Results: Compared to Con piglets all additives
positively influenced weight gain and feed conversion in week 1. Over the
whole trial period no significant differences in performance parameters
existed between the experimental groups. Compared to group Con performance of
Ro piglets was, however, slightly impaired. Com- pared to Con piglets Cuo, Oo
and To increased the ratio of Lactobacilli:E. coli attached to the jejunal
mucosa, whereas BE and Ro impaired this ratio slightly. In contrast in colonic
mucosa Ro improved Lactobacilli:E. coli ratio. In faecal samples an
improvement of Lactobacilli:E. coli ratio could be analysed for To and Ro. Ro
was the only additive that reduced the incidence rate of piglets tested
positive for enterotoxic E. coli (ETEC). All additives significantly increased
jejunal TEAC and reduced TBA-RS. In the liver BE, Cuo, Oo and To increased
TEAC in tendency and Ro significantly. Liver TBA-RS were slightly reduced by
all additives compared to Con piglets. Whereas the influence of BE, To and Ro
on jejunal TEAC mainly was derived from the induction of xenobiotic and
antioxidant enzymes (indirect antioxidant effects), Cuo and Oo influenced TEAC
by direct antioxidant effects. Discussion and Conclusions: Our results have
shown: That within the labiatae oils Oo and To have the potential to improve
performance slightly. That phytogenic substances have a small but not sig-
nificant influence on intestinal microflora. That phytogenic feed additives
up-regulate the anti- oxidant system of piglets either by direct or by
indirect antioxidant effects and that they may thereby improve health status.
That within the labiatae oils Oo has a high direct antioxidant potential
whereas Ro potently induces xenobiotic and antioxidant enzymes. That broccoli
extract is an attractive new phytogenic additive, improving antioxidant status
by indirect antioxidant effects. That defined combinations of selected
phytogenic substances may produce additive effects. That health promoting
effects of phytogenic additives in the future should be studied systematically
under the challenge with pathogenic microorganisms or food derived to-xins
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