The effects of exercise intensity and post-exercise recovery time on cortical activation as revealed by EEG alpha peak frequency.

Acute physical exercise (APE) induces an increase in the individual alpha peak frequency (iAPF), a cortical parameter associated with neural information processing speed. The aim of this study was to further scrutinize the influence of different APE intensities on post-exercise iAPF as well as its time course after exercise cessation. 95 healthy young (18-35 years) subjects participated in two randomized controlled experiments (EX1 and EX2). In EX1, all participants completed a graded exercise test (GXT) until exhaustion and were randomly allocated into different delay groups (immediately 0, 30, 60 and 90 min after GXT). The iAPF was determined before, immediately after as well as after the group-specific delay following the GXT. In EX2, participants exercised for 35 min at either 45-50%, 65-70% or 85-90% of their maximum heart rate (HRmax). The iAPF was determined before, immediately after as well as 20 min after exercise cessation. In EX1, the iAPF was significantly increased immediately after the GXT in all groups. This effect was not any more detectable after 30 min following exercise cessation. In EX2, a significant increase of the iAPF was found only after high-intensity (85-90% HRmax) exercise. The results indicate intense or exhaustive physical exercise is required to induce a transient increase in the iAPF that persists about 30 min following exercise cessation. Based on these findings, further research will have to scrutinize the behavioral implications associated with iAPF modulations following exercise.

Long-term treatment of aged Long Evans rats with a dietary supplement containing neuroprotective peptides (N-PEP-12) to prevent brain aging: effects of three months daily treatment by oral gavage.

Aging is associated with morphological and functional changes in the brain, resulting in the deterioration of cognitive performance. Growth factors like BDNF are suggested to be involved in the regulation of age-related processes in the brain. A novel dietary supplement produced from purified nerve cell proteins, N-PEP-12, has shown to share properties with naturally occurring peptide growth factors by stimulating neurite outgrowth and beneficial effects on neuronal survival and protection against metabolic stress in cell cultures. The current study investigates the effects of long-term intake on age-dependent memory decline by assessing cognitive performance and synaptic density. All the experiments were performed in aged Long Evans rats randomly assigned to saline or N-PEP-12 once daily by gavage over a period of three months. Behavioral tests were performed in the Morris Water Maze after one, two and three months of treatment. Histological examinations were performed in the hippocampal formation and in the entorhinal cortex by measuring the synaptic density. This study shows that the oral intake of N-PEP-12 has beneficial effects on the cognitive performance of aged animals and that these effects go along with an increase in the synaptic density. Thus, N-PEP-12 may help maintain memory and learning performance during the aging process.

[Clinical evaluation of evidence-based criteria for CT diagnostics in the treatment of mild traumatic brain injury]. / Klinische Evaluation evidenzbasierter Kriterien für die CT-Diagnostik bei der Behandlung der Commotio cerebri.

AIM: The mild traumatic brain injury (MTBI) is one of the most frequent diseases treated in emergency departments. Extensive studies addressing evidence-based treatment criteria have been published, the indication for CT scans depending on clinical symptoms appeared to be one of the critical issues. In this study, the question was raised whether or not the developed evidence-based criteria may be transferred to the patients of a German level 1 trauma centre. PATIENTS AND METHODS: Within 2 years (2004/05) 1841 patients with a traumatic brain injury were treated, 1042 patients with a mild traumatic brain injury and with an age over 14 years were included in the study. The indication for a head CT scan was checked by criteria of a phase 3 study (New Orleans Criteria - NOC). Furthermore, the length of hospitalisation, number and character of secondary aggravation, and kind of inpatient care were analysed. RESULTS: 69.5 % of our patients were diagnosed with the help of a CT scan, according to the evidence criteria 98.8 % of the patients should have been scanned (p > 0.001). A secondary aggravation caused by a cerebral lesion was found in 3 patients without a CT scan, all of these patients would have been scanned according to the NOC (n. s.). The fraction of patients with alcohol intoxication reached 44 %, a rate that is significantly higher compared to other international studies. These patients were not as often scanned (p < 0.001) and had a shorter hospital stay (p < 0.001) compared to other patients. Duration of hospital stay was prolonged depending on the severity of the brain injury and occurrence of secondary aggravation (p < 0.001). CONCLUSION: Summarising, the high sensitivity of the investigated evidence-based criteria (NOC) could be confirmed, but the application would not have led to a reduction of CT scans within our population.

Targeted-HASTE imaging with automated device tracking for MR-guided needle interventions in closed-bore MR systems.

Percutaneous MR-guided interventions with needles require fast pulse sequences to image the needle trajectory with minimal susceptibility artifacts. Spin-echo pulse sequences are well suited for reducing artifact size; however, even with single-shot turbo spin-echo techniques, such as rapid acquisition with relaxation enhancement (RARE) or half-Fourier acquisition single-shot turbo spin-echo (HASTE), fast imaging remains challenging. In this work we present a HASTE pulse sequence that is combined with inner-volume excitation to reduce the scan time and limit the imaging field of view (FOV) to a small strip close to the needle trajectory (targeted-HASTE). To compensate for signal saturation from fast repeated acquisitions, a magnetization restore pulse (driven equilibrium Fourier transform (DEFT)) is used. The sequence is combined with dedicated active marker coils to measure the position and orientation of the needle so that the targeted-HASTE image slice is automatically repositioned. In an animal experiment the coils were attached to an MR-compatible robotic assistance system for MR-guided interventions. Needle insertion and infusion via the needle could be visualized with a temporal resolution of 1 s, and the needle tip could be localized even in the presence of a stainless steel mandrel.

Phase unwrapping with the branch-cut method: role of phase-field direction.

Phase unwrapping with the branch-cut method has been successfully used in many different applications in recent years. Most methods to set the branch cuts minimize the overall cut length. However, this technique fails in different cases, since this criterion is based mainly on statistical examinations. We show how the orientation and direction of the phase map help to create additional physical criteria that can be used to optimize the setting of the branch cuts. We show how these new criteria can be implemented into an energy function that will be minimized by a simulated annealing algorithm in order of a correct setting of the branch cuts. Finally, we present experimental results from electronic speckle pattern interferometry and digital holography phase maps.

An exceptional group-I intron-like insertion in the SSU rDNA of lichen mycobionts.

An exceptional group-I intron-like insertion at position 940 of the nuclear small subunit rDNA is found in lichen mycobionts of the families Parmeliaceae and Lecanoraceae. This shared insertion site is exceptional as it follows a G. Although several features of the self-splicing Tetrahymena intron are missing, the conserved structure of the presumed core region indicates that the new intron-like insertion, which is missing in mature transcripts, is not part of a silenced ribosomal repeat. It is unlikely that the new insertion is horizontally transferred from the adjacent position 943. A phylogenetic analysis indicates congruence with lichen phylogeny and suggests that the insertion has been vertically inherited.

Phase unwrapping with the branch-cut method: clustering of discontinuity sources and reverse simulated annealing.

The branch-cut method is a powerful tool for correct unwrapping of phase maps in optical metrology. However, this method encounters the problem of the correct setting of the cuts, which belongs to the class of nondeterministic-polynomial-time-complete problems. Simulated annealing is an algorithm used to solve problems of this kind in a polynomial-time execution. However, the algorithm still requires an enormous calculation time if the number of discontinuity sources and thus the number of branch cuts is high. We illustrate the motivation for the use of this algorithm and show how the running time can be severely reduced by use of reverse simulated annealing, starting from the nearest-neighbor solution to find a proper initial configuration, and by clustering of discontinuity sources.

Phase-shifter calibration and error detection in phase-shifting applications: a new method.

The phase-shifting technique is used in optical metrology to evaluate the local phase of a fringe pattern. Accurate calibration of the shifting device is often essential but sometimes hardly possible because of deviations of the fringe pattern from the ideal sinusoidal shape and because of a nonconstant phase shift between consecutive frames. We introduce a new technique for calculating the phase shift between frames even in the presence of high noise and nonsinusoidal fringe patterns. In addition, this technique permits the identification of different error sources such as low signal-to-noise ratio, higher harmonics contained in the fringe pattern, and nonconstant phase shift.

Application of fuzzy-rule-based postprocessing to correlation methods in pattern recognition.

The use of fuzzy-logic techniques on the correlation output plane is analyzed as a method to improve the discrimination capabilities of pattern-recognition procedures. The study is divided into two parts: one recounts a computer-simulated example corresponding to pattern recognition by the use of input images that may be defocused, tilted, or corrupted by additive Gaussian noise, and the second part describes an experimental setup in which the deformation of foam material is studied.

[Experiences with oral immunization of foxes against rabies in Hesse]. / Erfahrungen mit der oralen Immunisierung von Füchsen gegen Tollwut in Hessen.

Since spring 1983 a field trial to immunize foxes by the oral route against rabies has been carried out in a heavily infected area of Hessen measuring about 1,500 km2. The vaccine strain SAD B 19, produced by the Federal Research Institute for Animal Virus Diseases at Tübingen and filled into 2 ml aliquots, was inserted into chicken heads and distributed by forest rangers in the trial area, 15 baits per km2. Up to the present day five baiting campaigns, two per year in spring and autumn, have been completed and in all 110,000 vaccine baits additionally marked with 150 mg tetracycline were layed out. Four baitings have been previously evaluated. With the exception of some rabies cases on the border to the unvaccinated region in the northwest, rabies was reduced impressively. A secondary outbreak in the region of Hausen/Kiedrich, caused by an extremely high density of the fox population, was eradicated by increasing the baits to 25 per km2. The number of rabies cases, which amounted to 238 within 15 months prior to the vaccination trial, went down from 38 in the first 6 months to 6 cases after the fourth baiting. As innocuity control 2,273 wild and domestic animals from the vaccination area were examined for the presence of the vaccine virus. The results were always negative indicating that rabies strain SAD B 19 had not established an infective cycle in wildlife. As could be shown by the marker studies, an average of 78 per cent of the foxes (variation of the baitings from 62 per cent to 82 per cent) had taken up one or more baits. Seroconversion had been achieved in 65 per cent of the foxes (variation from 43 per cent to 70 per cent) as demonstrated by the presence of neutralizing antibodies. From experiences in Switzerland it can be expected, that rabies will be extinguished, if 50 per cent of the population are successfully immunized. This value has been surpassed in the field trial in Hessen. These very promising results have led to the project of an enlargement of the vaccination area to 12,000 km2. The neighbouring states of Rheinland-Pfalz and Nordrhein-Westfalen have joined in this effort, which has started in autumn 1985 with a new artificial vaccine bait developed at the Tübingen research institute.