Stabilized Radiation Pressure Acceleration and Neutron Generation in Ultrathin Deuterated Foils.

Premature relativistic transparency of ultrathin, laser-irradiated targets is recognized as an obstacle to achieving a stable radiation pressure acceleration in the "light sail" (LS) mode. Experimental data, corroborated by 2D PIC simulations, show that a few-nm thick overcoat surface layer of high Z material significantly improves ion bunching at high energies during the acceleration. This is diagnosed by simultaneous ion and neutron spectroscopy following irradiation of deuterated plastic targets. In particular, copious and directional neutron production (significantly larger than for other in-target schemes) arises, under optimal parameters, as a signature of plasma layer integrity during the acceleration.

Time-resolved study of holeboring in realistic experimental conditions.

The evolution of dense plasmas prior to the arrival of the peak of the laser irradiation is critical to understanding relativistic laser plasma interactions. The spectral properties of a reflected laser pulse after the interaction with a plasma can be used to gain insights about the interaction itself, whereas the effect of holeboring has a predominant role. Here we developed an analytical model, describing the non-relativistic temporal evolution of the holeboring velocity in the presence of an arbitrary overdense plasma density and laser intensity profile. We verify this using two-dimensional particle-in-cell simulations, showing a major influence on the holeboring dynamic depending on the density profile. The influence on the reflected laser pulse has been verified during an experiment at the PHELIX laser. We show that this enables the possibility to determine the sub-micrometer scale length of the preplasma by measuring the maximum holeboring velocity and acceleration during the laser-plasma interaction.

Inducing signal-verified lucid dreams in 40% of untrained novice lucid dreamers within two nights in a sleep laboratory setting.

Dreams in which the dreamer is aware of the dream state (lucid dreams, LD) are difficult to induce in naïve subjects in-laboratory. Recently, Stumbrys and Erlacher (2014) used a combination of existing induction techniques together with a self-developed experiment protocol and achieved comparatively high LD induction rates. In this study, we simplified their methodology slightly and repeated their experiment with twenty naïve subjects who spent one or two nights in our sleep laboratory. After about six hours of sleep, they were woken up during REM sleep and engaged in a series of cognitive tasks before going back to bed. Ten subjects reported a LD during the following period of sleep in one of the nights. Eight of these subjects gave a predefined eye signal, which was clearly visible in the electrooculogram during REM sleep. In summary, we replicated Stumbrys and Erlacher's results using a simplified version of their induction protocol.

Maximum Proton Energy above 85 MeV from the Relativistic Interaction of Laser Pulses with Micrometer Thick CH_{2} Targets.

We present a study of laser-driven ion acceleration with micrometer and submicrometer thick plastic targets. Using laser pulses with high temporal contrast and an intensity of the order of 10^{20} W/cm^{2} we observe proton beams with cutoff energies in excess of 85 MeV and particle numbers of 10^{9} in an energy bin of 1 MeV around this maximum. We show that applying the target normal sheath acceleration mechanism with submicrometer thick targets is a very robust way to achieve such high ion energies and particle fluxes. Our results are backed with 2D particle in cell simulations furthermore predicting cutoff energies above 200 MeV for acceleration based on relativistic transparency. This predicted regime can be probed after a few technically feasible adjustments of the laser and target parameters.

Calibration of time of flight detectors using laser-driven neutron source.

Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

Spatially invariant coding of numerical information in functionally defined subregions of human parietal cortex.

Macaque electrophysiology has revealed neurons responsive to number in lateral (LIP) and ventral (VIP) intraparietal areas. Recently, fMRI pattern recognition revealed information discriminative of individual numbers in human parietal cortex but without precisely localizing the relevant sites or testing for subregions with different response profiles. Here, we defined the human functional equivalents of LIP (feLIP) and VIP (feVIP) using neurophysiologically motivated localizers. We applied multivariate pattern recognition to investigate whether both regions represent numerical information and whether number codes are position specific or invariant. In a delayed number comparison paradigm with laterally presented numerosities, parietal cortex discriminated between numerosities better than early visual cortex, and discrimination generalized across hemifields in parietal, but not early visual cortex. Activation patterns in the 2 parietal regions of interest did not differ in the coding of position-specific or position-independent number information, but in the expression of a numerical distance effect which was more pronounced in feLIP. Thus, the representation of number in parietal cortex is at least partially position invariant. Both feLIP and feVIP contain information about individual numerosities in humans, but feLIP hosts a coarser representation of numerosity than feVIP, compatible with either broader tuning or a summation code.

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers.

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C(6+), O(8+), etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser.

Neuroimaging of diving-related decompression illness: current knowledge and perspectives.

Diving-related decompression illness is classified into 2 main categories: arterial gas embolism and decompression sickness. The latter is further divided into types 1 and 2, depending on the clinical presentation. MR imaging is currently the most accurate neuroimaging technique available for the detection of brain and spinal cord lesions in neurologic type 2 decompression sickness. Rapid bubble formation in tissues and the bloodstream during ascent is the basic pathophysiologic mechanism in decompression illness. These bubbles can damage the central nervous system through different mechanisms, namely arterial occlusion, venous obstruction, or in situ toxicity. Neuroimaging studies of decompression sickness have reported findings associated with each of these mechanisms: some typical results are summarized and illustrated in this article. We also review the limitations of previous work and make practical methodologic suggestions for future neuroimaging studies.

Treatment with the interleukin-17A-blocking antibody secukinumab does not interfere with the efficacy of influenza and meningococcal vaccinations in healthy subjects: results of an open-label, parallel-group, randomized single-center study.

Our objective was to evaluate the efficacy of influenza and meningococcal vaccinations in healthy subjects exposed to the anti-interleukin-17A (IL-17A) monoclonal antibody (MAb) secukinumab. We used an open-label, parallel-group, randomized single-center study of 50 healthy subjects. Subjects received a single 150-mg dose of secukinumab or no treatment, followed by vaccination with inactivated trivalent subunit influenza virus and conjugate group C meningococcal vaccine (Agrippal and Menjugate, respectively) 2 weeks later. Primary efficacy variables were responses of ≥4-fold increases in antibody titer (hemagglutination inhibition [HI; for influenza virus] and serum bactericidal assay [SBA; for Neisseria meningitides]) for meningococcus and influenza (at least two out of three serotypes), both at 4 weeks postvaccination. All subjects randomized to secukinumab (n = 25) or the control (n = 25) completed the study. Antibody responses to vaccinations measured at 4 weeks were comparable in both groups, with ≥4-fold increased responses following influenza virus vaccination of 20/25 (80%) for both groups and following meningococcal vaccination of 19/25 (76%) for the secukinumab group and 18/25 (72%) for the control group. Differences between groups were 0% (90% confidence intervals [CI], 19 and 19%) and 4% (90% CI, 16 and 24%) for influenza virus and meningococcal vaccines, respectively. Antibody responses were comparable between the 2 groups at different time points. Headache was the most frequently reported adverse effect. No deaths or serious adverse events were reported. Blockade of IL-17A by secukinumab does not appear to interfere with efficacy of influenza and meningococcal vaccinations, as assessed by the achievement of protective antibody levels. A protective (≥4-fold) immune response to both vaccinations at 4 weeks was achieved in 80 and 76% of subjects exposed to secukinumab and the control, respectively.

Scale-Free and Multifractal Time Dynamics of fMRI Signals during Rest and Task.

Scaling temporal dynamics in functional MRI (fMRI) signals have been evidenced for a decade as intrinsic characteristics of ongoing brain activity (Zarahn et al., 1997). Recently, scaling properties were shown to fluctuate across brain networks and to be modulated between rest and task (He, 2011): notably, Hurst exponent, quantifying long memory, decreases under task in activating and deactivating brain regions. In most cases, such results were obtained: First, from univariate (voxelwise or regionwise) analysis, hence focusing on specific cognitive systems such as Resting-State Networks (RSNs) and raising the issue of the specificity of this scale-free dynamics modulation in RSNs. Second, using analysis tools designed to measure a single scaling exponent related to the second order statistics of the data, thus relying on models that either implicitly or explicitly assume Gaussianity and (asymptotic) self-similarity, while fMRI signals may significantly depart from those either of those two assumptions (Ciuciu et al., 2008; Wink et al., 2008). To address these issues, the present contribution elaborates on the analysis of the scaling properties of fMRI temporal dynamics by proposing two significant variations. First, scaling properties are technically investigated using the recently introduced Wavelet Leader-based Multifractal formalism (WLMF; Wendt et al., 2007). This measures a collection of scaling exponents, thus enables a richer and more versatile description of scale invariance (beyond correlation and Gaussianity), referred to as multifractality. Also, it benefits from improved estimation performance compared to tools previously used in the literature. Second, scaling properties are investigated in both RSN and non-RSN structures (e.g., artifacts), at a broader spatial scale than the voxel one, using a multivariate approach, namely the Multi-Subject Dictionary Learning (MSDL) algorithm (Varoquaux et al., 2011) that produces a set of spatial components that appear more sparse than their Independent Component Analysis (ICA) counterpart. These tools are combined and applied to a fMRI dataset comprising 12 subjects with resting-state and activation runs (Sadaghiani et al., 2009). Results stemming from those analysis confirm the already reported task-related decrease of long memory in functional networks, but also show that it occurs in artifacts, thus making this feature not specific to functional networks. Further, results indicate that most fMRI signals appear multifractal at rest except in non-cortical regions. Task-related modulation of multifractality appears only significant in functional networks and thus can be considered as the key property disentangling functional networks from artifacts. These finding are discussed in the light of the recent literature reporting scaling dynamics of EEG microstate sequences at rest and addressing non-stationarity issues in temporally independent fMRI modes.

[Increased self-confidence and decreased sexual discomfort after subpectoral mammaplasty]. / Gesteigertes Selbstvertrauen und vermindertes körperlich-sexuelles Missempfinden nach subpektoraler Mammaaugmentation.

INTRODUCTION: The study objectively discusses the causal relationship between submuscular breast augmentation mammaplasty and improved aspects of quality of life. The goal was to assess a possible increase in certain aspects after undergoing cosmetic breast enlargement surgery under consideration of 4 different aspects. MATERIALS AND METHODS: Between 2005 and 2006, a total of 65 women were given a standardised patient questionnaire (body image assessment questionnaire) preoperatively as well as 6 months postoperatively after undergoing cosmetic submuscular augmentation mammaplasty: 58 of these questionnaires could be evaluated successfully. All of the patients had undergone augmentation mammaplasty for the first time. The following criteria were assessed and evaluated using a point value system (0-100 points): attractiveness/self-confidence, insecurity/anxiety, emphasis placed on physical appearance, and sexual discomfort. RESULTS: With regard to the questions dealing with attractiveness/self-confidence, a highly significant improvement in the patient's self-assessment of said criteria after undergoing cosmetic submuscular augmentation mammaplasty as compared to their own preoperative assessment was apparent. In addition, a significantly improved level of sexual satisfaction after the medical procedure was also demonstrated. In the same fashion, the answers to the series of questions dealing with emphasis placed on physical appearance also exhibited a positive change. The only topic that exhibited next to no change was the series of questions dealing with insecurity/anxiety. CONCLUSION: Cosmetic augmentation mammaplasty is an available therapy that can increase a patient's own self-assessment of attractiveness and self-confidence in a significant way. In addition, this operation leads to a significant increase in sexual satisfaction, and because of this and the aforementioned change of emphasis placed on physical appearance, an overall improvement in certain aspects of the quality of life can be achieved.

Influenza and meningococcal vaccinations are effective in healthy subjects treated with the interleukin-1 beta-blocking antibody canakinumab: results of an open-label, parallel group, randomized, single-center study.

The objective of this study was to evaluate the efficacy of influenza and meningococcal vaccines in healthy subjects exposed to the anti-interleukin-1ß (anti-IL-1ß) monoclonal antibody canakinumab. This was an open-label, parallel group, randomized, single-center study of healthy subjects (aged 18 to 45 years). At baseline, antibody (Ab) titers were measured and subjects were randomized (1:1) to a single 300-mg canakinumab dose administered subcutaneously (s.c.) or received no treatment (control group). After 2 weeks, subjects were treated with inactivated, unadjuvanted influenza and conjugated group C meningococcal (MenC) vaccines, administered intramuscularly (i.m.). The primary efficacy variable was the response (≥ 2-fold increase in Ab titer in ≥ 2 of 3 influenza virus strains) after 4 weeks in subjects treated with canakinumab compared to the control group. Secondary efficacy variables were the antibody response to vaccines at different thresholds and time points. Fifty-one of 112 subjects screened were randomized to canakinumab (n = 25) or the control group (n = 26). Antibody responses to vaccinations measured against different influenza virus strains and one MenC strain at 4 weeks were comparable in the canakinumab and control groups. The primary efficacy variable, the response to influenza vaccination (≥ 2-fold increase in Ab titer in ≥ 2 of 3 serotypes) at 4 weeks, was shown in 24/25 subjects in the canakinumab group compared to 25/25 subjects in the control group. Antibody responses remained comparable in the two groups at the different time points assessed. Headache was the most frequently reported adverse event. No deaths or serious adverse events were reported during the study. We concluded that a single dose of 300 mg canakinumab s.c. does not affect the induction or persistence of antibody responses after vaccination with unadjuvanted influenza or alum-adjuvanted MenC vaccines in healthy subjects.

A group model for stable multi-subject ICA on fMRI datasets.

Spatial Independent Component Analysis (ICA) is an increasingly used data-driven method to analyze functional Magnetic Resonance Imaging (fMRI) data. To date, it has been used to extract sets of mutually correlated brain regions without prior information on the time course of these regions. Some of these sets of regions, interpreted as functional networks, have recently been used to provide markers of brain diseases and open the road to paradigm-free population comparisons. Such group studies raise the question of modeling subject variability within ICA: how can the patterns representative of a group be modeled and estimated via ICA for reliable inter-group comparisons? In this paper, we propose a hierarchical model for patterns in multi-subject fMRI datasets, akin to mixed-effect group models used in linear-model-based analysis. We introduce an estimation procedure, CanICA (Canonical ICA), based on i) probabilistic dimension reduction of the individual data, ii) canonical correlation analysis to identify a data subspace common to the group iii) ICA-based pattern extraction. In addition, we introduce a procedure based on cross-validation to quantify the stability of ICA patterns at the level of the group. We compare our method with state-of-the-art multi-subject fMRI ICA methods and show that the features extracted using our procedure are more reproducible at the group level on two datasets of 12 healthy controls: a resting-state and a functional localizer study.

Development and restructuring of a burn centre in an emerging nation, based on the example of Kyrgyzstan.

AIM: To implement and review a four-tier plan to develop a burn centre in an emerging nation (Kyrgyzstan). METHOD: From 2001, the developing burn centre in Bishkek was supported with numerous material donations and, once a year, teams from Germany operatively treated numerous burn victims on site. Training and further education for our Kyrgyzstani colleagues were based on 'helping them to help themselves', with additional consultations on conceptual hygienic and structural improvements. RESULTS: Material donations were delivered personally by the project teams. Education and training were also limited due to physician emigration. However, in the seven trips made by the team from Germany, numerous operations were performed and there was fundamental progress in the areas of bandaging protocols, hygienic concepts and structural improvements. CONCLUSION: An exact plan patiently tailored to the local situation and culture must be followed, to provide cost-effective support.

Recent advances in recording electrophysiological data simultaneously with magnetic resonance imaging.

Simultaneous recording of brain activity by different neurophysiological modalities can yield insights that reach beyond those obtained by each technique individually, even when compared to those from the post-hoc integration of results from each technique recorded sequentially. Success in the endeavour of real-time multimodal experiments requires special hardware and software as well as purpose-tailored experimental design and analysis strategies. Here, we review the key methodological issues in recording electrophysiological data in humans simultaneously with magnetic resonance imaging (MRI), focusing on recent technical and analytical advances in the field. Examples are derived from simultaneous electroencephalography (EEG) and electromyography (EMG) during functional MRI in cognitive and systems neuroscience as well as in clinical neurology, in particular in epilepsy and movement disorders. We conclude with an outlook on current and future efforts to achieve true integration of electrical and haemodynamic measures of neuronal activity using data fusion models.

Where the BOLD signal goes when alpha EEG leaves.

Previous studies using simultaneous EEG and fMRI recordings have yielded discrepant results regarding the topography of brain activity in relation to spontaneous power fluctuations in the alpha band of the EEG during eyes-closed rest. Here, we explore several possible explanations for this discrepancy by re-analyzing in detail our previously reported data. Using single subject analyses as a starting point, we found that alpha power decreases are associated with fMRI signal increases that mostly follow two distinct patterns: either 'visual' areas in the occipital lobe or 'attentional' areas in the frontal and parietal lobe. On examination of the EEG spectra corresponding to these two fMRI patterns, we found greater relative theta power in sessions yielding the 'visual' fMRI pattern during alpha desynchronization and greater relative beta power in sessions yielding the 'attentional' fMRI pattern. The few sessions that fell into neither pattern featured the overall lowest theta and highest beta power. We conclude that the pattern of brain activation observed during spontaneous power reduction in the alpha band depends on the general level of brain activity as indexed over a broader spectral range in the EEG. Finally, we relate these findings to the concepts of 'resting state' and 'default mode' and discuss how - as for sleep - EEG-based criteria might be used for staging brain activity during wakefulness.

Visual search in patients with subcortical vascular dementia: short fixations but long reaction times.

Visual search is a cognitive function of high ecological relevance. It involves rapid alternations between allocating and shifting attention. In patients with Alzheimer's disease, the duration of fixations during visual search increases already in the early stage of the illness. Subcortical vascular dementia (SVD), a newly defined subgroup of vascular dementia, has not yet been examined in this respect. SVD affects patients with a history of lacunar infarctions and/or transient ischemic attacks, focal neurological signs and evidence of subcortical white matter lesions as well as lacunes in the deep grey matter. Here, we report our findings from tracking eye movements during a visual search task with different array sizes in 9 patients with SVD and compare the number and duration of eye fixations they made with the values obtained in 9 healthy elderly control subjects. While patients with SVD were significantly slower in the tasks with longer center to target distances (mean reaction time), the number and duration of fixations they made did not differ from those in controls. Impairment of visual search in patients with SVD seems to be an effect of general cognitive slowing in more demanding arrays of visual search rather than a specific deficit in parameters of eye fixation.

Effects of arousing emotional scenes on the distribution of visuospatial attention: changes with aging and early subcortical vascular dementia.

BACKGROUND: The modulation of attention by emotionally arousing stimuli is highly important for each individual's social function. Disturbances of emotional processing are a supportive feature for the diagnosis of subcortical vascular dementia (SVD). We address here whether these disturbances might be useful as an early disease marker. METHODS: In order to examine the modulation of visual attention by emotionally arousing stimuli of different valence, 12 elderly patients with early SVD, 12 age-comparable healthy adults and 12 young healthy subjects were studied while looking at pairs of pictures from the International Affective Picture Battery that were either neutral-neutral, neutral-positive or neutral-negative in terms of emotional content. Eye movements were recorded with an infrared eye-tracking system. The direction of the first saccade and the dwell time during the 10 s of presentation were measured and compared among groups with parametric tests. RESULTS: All subjects showed a modulation of initial attentional orienting as well as a higher percentage of dwell time towards the pictures containing emotional material. Patients with SVD and old controls did not differ in either experimental measure. Young patients showed a stronger bias towards emotionally negative material than both groups of older individuals. CONCLUSIONS: Modulation of visuospatial attention is preserved in early SVD. This might have implications for therapeutic interventional approaches. A weakened sustained attention towards negative but not positive emotional pictures in the elderly is in accordance with the socioemotional selectivity theory, describing a relative selection of positive stimuli with aging.

Contributions of sensory input, auditory search and verbal comprehension to cortical activity during speech processing.

We studied eight normal subjects in an fMRI experiment where they listened to natural speech sentences and to matched simple or complex speech envelope noises. Neither of the noises (simple or complex) were understood initially, but after the corresponding natural speech sentences had been heard, comprehension was close to perfect for the complex but still absent for the simple speech envelope noises. This setting thus involved identical stimuli that were understood or not and permitted to identify (i) a neural substrate of speech comprehension unconfounded by stimulus acoustic properties (common to natural speech and complex noises), (ii) putative correlates of auditory search for phonetic cues in noisy stimuli (common to simple and complex noises once the matching natural speech had been heard) and (iii) the cortical regions where speech comprehension and auditory search interact. We found correlates of speech comprehension in bilateral medial (BA21) and inferior (BA38 and BA38/21) temporal regions, whereas acoustic feature processing occurred in more dorsal temporal regions. The left posterior superior temporal cortex (Wernicke's area) responded to the acoustic complexity of the stimuli but was additionally sensitive to auditory search and speech comprehension. Attention was associated with recruitment of the dorsal part of Broca's area (BA44) and interaction of auditory attention and comprehension occurred in bilateral insulae, the anterior cingulate and the right medial frontal cortex. In combination, these results delineate a neuroanatomical framework for the functional components at work during natural speech processing, i.e. when comprehension results from concurrent acoustic processing and effortful auditory search.