Validation of the Munich Swallowing Score (MUCSS) in patients with neurogenic dysphagia: A preliminary study.

BACKGROUND: The Munich Swallowing Score (MUCSS) is a clinician rated scale for the assessment of the functional level of swallowing saliva/secretions, food and liquids. The MUCSS consists of two eight-point subscales, MUCSS-Saliva and MUCSS-Nutrition. In a previous article, content validity and interrater reliability were described. OBJECTIVE: The aim of the present study was to investigate criterion validity and sensitivity to change of the MUCSS. METHODS: The research was conducted at a tertiary care academic hospital. Data were collected retrospectively in a cohort of 100 acute and subacute neurologic patients. Criterion validity was judged by comparison to the Gugging Swallowing Screen (GUSS), the Barthel Index (BI), Early Rehabilitation Barthel Index (ERI), Extended Barthel Index (EBI) and also by comparison to three physiological scales drawn from FEES videos: The Penetration - Aspiration Scale (PAS), the Yale Pharyngeal Residue Severity Rating Scale (YPR) and the Murray Secretion Scale (MSS). Changes in oral intake and saliva swallowing were followed up for three months. RESULTS: Between MUCSS and scores directly reflecting dysphagic symptoms (GUSS, PAS, YPR, MSS, ERI), strong to moderate correlations were found, weaker but statistically significant associations were seen with global measures of disability (BI isolated, EBI-subscale cognitive functions). MUCSS was sensitive to positive change of saliva swallowing and oral intake during the recovery period. CONCLUSIONS: These preliminary data suggest that the MUCCS is a valid scale and may be appropriate for documenting clinical change in swallowing abilities of patients with neurogenic dysphagia.

Controlling the Self-Injection Threshold in Laser Wakefield Accelerators.

Controlling the parameters of a laser plasma accelerated electron beam is a topic of intense research with a particular focus placed on controlling the injection phase of electrons into the accelerating structure from the background plasma. An essential prerequisite for high-quality beams is dark-current free acceleration (i.e., no electrons accelerated beyond those deliberately injected). We show that small-scale density ripples in the background plasma are sufficient to cause the uncontrolled (self-)injection of electrons. Such ripples can be as short as ∼50 µm and can therefore not be resolved by standard interferometry. Background free injection with substantially improved beam characteristics (divergence and pointing) is demonstrated in a gas cell designed for a controlled gas flow. The results are supported by an analytical theory as well as 3D particle in cell simulations.

TIMP3 is Regulated by Pericytes upon Shear Stress Detection Leading to a Modified Endothelial Cell Response.

OBJECTIVES: Atherosclerosis is a hallmark of cardiovascular disease. Shear stress on endothelial cells has been linked to atherogenesis and to fibrous cap thinning and rupture. Pericytes reside in the sub-endothelial space of vessels and have vasoprotective effects. They are subjected to shear stress when endothelial cell integrity is disrupted. The aim was to investigate the susceptibility and response of pericytes to shear stress. METHODS: Endothelial cells and pericytes were seeded in two dimensional monocultures and co-cultures, and in a novel three dimensional co-culture system and were subjected to no, low and high shear stress (0, 10, 30 dyne/cm2) for 48 h. The morphological response to flow was assessed by histology and the expression of extracellular matrix proteins was analysed using quantitative polymerase chain reaction, immunoblotting, and ELISA. RESULTS: While endothelial cells aligned into flow direction, pericytes aligned perpendicularly (p < .001), indicating that they must be capable of sensing flow. When pericytes were embedded into a 3D matrix they showed similar alignment and pericytes built long processes towards the lumen. Under shear stress endothelial cells upregulated "a disintegrin and metalloproteinase with thrombospondin motif 1" (ADAMTS-1) (p < .01) and pericytes upregulated "tissue inhibitor of matrix metalloproteinase" (TIMP) 3 (p < .05), an inhibitor of ADAMTS-1, meanwhile differential expression of extracellular matrix (ECM) proteins could be detected in co-cultures of both cells. For TIMP3 expression direct cell-cell contact between endothelial cells and pericytes was required. CONCLUSION: The experiments highlight that pericytes are able to sense direct flow thereby regulating ECM proteins known to be involved in vascular remodelling. Furthermore, pericytes counter-regulate endothelial ADAMTS-1 by protective TIMP3 expression to prevent matrix degradation and maintain vascular stability. For this protective effect direct cell contact was necessary. This observation might represent an adaptive, protective mechanism of pericytes to counteract endothelial damage in the onset of atherosclerosis.

Subcortical Contributions to Motor Speech: Phylogenetic, Developmental, Clinical.

Vocal learning is an exclusively human trait among primates. However, songbirds demonstrate behavioral features resembling human speech learning. Two circuits have a preeminent role in this human behavior; namely, the corticostriatal and the cerebrocerebellar motor loops. While the striatal contribution can be traced back to the avian anterior forebrain pathway (AFP), the sensorimotor adaptation functions of the cerebellum appear to be human specific in acoustic communication. This review contributes to an ongoing discussion on how birdsong translates into human speech. While earlier approaches were focused on higher linguistic functions, we place the motor aspects of speaking at center stage. Genetic data are brought together with clinical and developmental evidence to outline the role of cerebrocerebellar and corticostriatal interactions in human speech.

High field electron paramagnetic resonance spectroscopy under ultrahigh vacuum conditions--a multipurpose machine to study paramagnetic species on well defined single crystal surfaces.

A new ultrahigh vacuum (UHV) electron paramagnetic resonance (EPR) spectrometer operating at 94 GHz to investigate paramagnetic centers on single crystal surfaces is described. It is particularly designed to study paramagnetic centers on well-defined model catalysts using epitaxial thin oxide films grown on metal single crystals. The EPR setup is based on a commercial Bruker E600 spectrometer, which is adapted to ultrahigh vacuum conditions using a home made Fabry Perot resonator. The key idea of the resonator is to use the planar metal single crystal required to grow the single crystalline oxide films as one of the mirrors of the resonator. EPR spectroscopy is solely sensitive to paramagnetic species, which are typically minority species in such a system. Hence, additional experimental characterization tools are required to allow for a comprehensive investigation of the surface. The apparatus includes a preparation chamber hosting equipment, which is required to prepare supported model catalysts. In addition, surface characterization tools such as low energy electron diffraction (LEED)/Auger spectroscopy, temperature programmed desorption (TPD), and infrared reflection absorption spectroscopy (IRAS) are available to characterize the surfaces. A second chamber used to perform EPR spectroscopy at 94 GHz has a room temperature scanning tunneling microscope attached to it, which allows for real space structural characterization. The heart of the UHV adaptation of the EPR experiment is the sealing of the Fabry-Perot resonator against atmosphere. To this end it is possible to use a thin sapphire window glued to the backside of the coupling orifice of the Fabry Perot resonator. With the help of a variety of stabilization measures reducing vibrations as well as thermal drift it is possible to accumulate data for a time span, which is for low temperature measurements only limited by the amount of liquid helium. Test measurements show that the system can detect paramagnetic species with a density of approximately 5 × 10(11) spins/cm(2), which is comparable to the limit obtained for the presently available UHV-EPR spectrometer operating at 10 GHz (X-band). Investigation of electron trapped centers in MgO(001) films shows that the increased resolution offered by the experiments at W-band allows to identify new paramagnetic species, that cannot be differentiated with the currently available methodology.

Characterization of 700 µJ T rays generated during high-power laser solid interaction.

Laser-produced solid density plasmas are well-known as table-top sources of electromagnetic radiation. Recent studies have shown that energetic broadband terahertz pulses (T rays) can also be generated from laser-driven compact ion accelerators. Here we report the measurement of record-breaking T-Ray pulses with energies no less than 0.7 mJ. The terahertz spectrum has been characterized for frequencies ranging from 0.1-133 THz. The dependence of T-Ray yield on incident laser energy is linear and shows no tendencies of saturation. The noncollinear emission pattern and the high yield reveal that the T rays are generated by the transient field at the rear surface of the solid target.

Observation of gigawatt-class THz pulses from a compact laser-driven particle accelerator.

We report the observation of subpicosecond terahertz (T-ray) pulses with energies ≥460 µJ from a laser-driven ion accelerator, thus rendering the peak power of the source higher even than that of state-of-the-art synchrotrons. Experiments were performed with intense laser pulses (up to 5×10(19) W/cm(2)) to irradiate thin metal foil targets. Ion spectra measured simultaneously showed a square law dependence of the T-ray yield on particle number. Two-dimensional particle-in-cell simulations show the presence of transient currents at the target rear surface which could be responsible for the strong T-ray emission.

Recovery from auditory and visual neglect after optokinetic stimulation with pursuit eye movements--transient modulation and enduring treatment effects.

Optokinetic stimulation (OKS) modulates many facets of the neglect syndrome. This sensory stimulation technique is known to activate multiple brain regions (temporo-parietal cortex, basal ganglia, brain stem, cerebellum) some of which are involved in auditory and visual space coding. Here, we evaluated whether OKS modulates auditory neglect transiently and induces a sustained effect (Study 1), and whether repetitive OKS permanently recovers auditory neglect (Study 2). In Study 1, 20 patients with visuospatial neglect and auditory neglect in an auditory midline task following rightsided stroke were randomly allocated to an experimental and a control group matched for neglect severity and socio-demographic factors. Both groups showed a stable, pathological shift of their auditory subjective median plane (ASMP) in front space to the right side. During leftward OKS the experimental group showed a complete normalization of the shift of the ASMP, which endured until 30 min poststimulation, and returned almost to baseline values 24h after OKS. In contrast, the control group who viewed the identical but static dot pattern, showed neither change in their ASMP during this condition, nor any significant change at 30 min or 24h poststimulation. In Study 2, we show in two samples of neglect patients (N = 3 each) that repetitive leftward OKS with smooth pursuit eye movements as a therapy induces lasting improvements in auditory (the ASMP) and visual neglect while visual scanning therapy yielded no measurable effects on auditory and significantly smaller effects on visual neglect. In conclusion, the experiments show that a single session of OKS induces rapid though transient recovery from auditory neglect including a sustained effect after termination of stimulation, while repetitive OKS therapy yields enduring and multimodal recovery from auditory and visual neglect. OKS therapy with pursuit eye movements therefore represents a multimodally effective and easily applicable technique for the treatment of auditory and visual neglect.

Auditory-motor integration during fast repetition: the neuronal correlates of shadowing.

This fMRI study examined which structures of a proposed dorsal stream system are involved in the auditory-motor integration during fast overt repetition. We used a shadowing task which requires immediate repetition of an auditory-verbal input and is supposed to elicit unconscious imitation effects of phonologically irrelevant speech parameters. Subjects' responses were recorded in the scanner. To examine automated auditory-motor mapping of speech gestures of others onto one's own speech production system we contrasted the shadowing of pseudowords produced by multiple speakers (men, women, and children) with the shadowing of pseudowords produced by a single speaker. Furthermore, we asked whether behavioral variables predicted changes in functional activation during shadowing. Shadowing multiple speakers compared to a single speaker elicited increased bilateral activation predominantly in the superior temporal sulci. These regions may mediate acoustic-phonetic speaker normalization in preparation of a translation of perceptual into motor information. Additional activation in Broca's area and the thalamus may reflect motor effects of the adaptation to multiple speaker models. Item-wise correlational analyses of response latencies with BOLD signal changes indicated that longer latencies were associated with increased activation in the left parietal operculum, suggesting that this area plays a central role in the actual transfer of auditory-verbal information to speech motor representations. A multiple regression of behavioral with imaging data showed activation in a right inferior parietal area near the temporo-parietal boundary which correlated positively with the degree of speech rate imitation and negatively with response latency. This activation may be attributable to attentional and/or paralinguistic processes.

Verb generation in children and adolescents with acute cerebellar lesions.

The aim of the present study was to examine verb generation in a larger group of children and adolescents with acute focal lesions of the cerebellum. Nine children and adolescents with cerebellar tumours participated. Subjects were tested a few days after tumour surgery. For comparison, a subgroup was tested also 1 or 2 days before surgery. None of the children had received radiation or chemotherapy at or before the time of testing. Eleven age- and education-matched control subjects participated. Subjects had to generate verbs to blocked presentations of photographs of objects. As control condition, the objects had to be named. Furthermore, dysarthria was quantified by means of a sentence production and syllable repetition task. Detailed analysis of individual 3D-MR images revealed that lesions affected cerebellar hemispheres in all children and adolescents. The right cerebellar hemisphere was affected in four and the left hemisphere in five subjects. In the present study, naming and verb generation accuracy were preserved in the majority of subjects with cerebellar lesions. No significant signs of learning deficits were observed, as reduction of reaction times over blocks was not different compared to controls. There was a trend of children and adolescents with right-hemispheric lesions to perform worse compared to controls. In this group, however, significant signs of dysarthria were present. In sum, no significant signs of disordered verb generation were observed in children and adolescents with acute cerebellar lesions. Findings suggest that the role of the cerebellum in verb generation may be less pronounced than previously suggested. Findings need to be confirmed in a larger group of subjects with acute focal lesions.

Laser-plasma acceleration of quasi-monoenergetic protons from microstructured targets.

Particle acceleration based on high intensity laser systems (a process known as laser-plasma acceleration) has achieved high quality particle beams that compare favourably with conventional acceleration techniques in terms of emittance, brightness and pulse duration. A long-term difficulty associated with laser-plasma acceleration--the very broad, exponential energy spectrum of the emitted particles--has been overcome recently for electron beams. Here we report analogous results for ions, specifically the production of quasi-monoenergetic proton beams using laser-plasma accelerators. Reliable and reproducible laser-accelerated ion beams were achieved by intense laser irradiation of solid microstructured targets. This proof-of-principle experiment serves to illuminate the role of laser-generated plasmas as feasible particle sources. Scalability studies show that, owing to their compact size and reasonable cost, such table-top laser systems with high repetition rates could contribute to the development of new generations of particle injectors that may be suitable for medical proton therapy.

Succession after stand replacing disturbances by fire, wind throw, and insects in the dark Taiga of Central Siberia.

The dark taiga of Siberia is a boreal vegetation dominated by Picea obovata, Abies sibirica, and Pinus sibirica during the late succession. This paper investigates the population and age structure of 18 stands representing different stages after fire, wind throw, and insect damage. To our knowledge, this is the first time that the forest dynamics of the Siberian dark taiga is described quantitatively in terms of succession, and age after disturbance, stand density, and basal area. The basis for the curve-linear age/diameter relation of trees is being analyzed. (1) After a stand-replacing fire Betula dominates (4,000 trees) for about 70 years. Although tree density of Betula decreases rapidly, basal area (BA) reached >30 m2/ha after 40 years. (2) After fire, Abies, Picea, and Pinus establish at the same time as Betula, but grow slower, continue to gain height and eventually replace Betula. Abies has the highest seedling number (about 1,000 trees/ha) and the highest mortality. Picea establishes with 100-400 trees/ha, it has less mortality, but reached the highest age (>350 years, DBH 51 cm). Picea is the most important indicator for successional age after disturbance. Pinus sibirica is an accompanying species. The widely distributed "mixed boreal forest" is a stage about 120 years after fire reaching a BA of >40 m2/ha. (3) Wind throw and insect damage occur in old conifer stands. Betula does not establish. Abies initially dominates (2,000-6,000 trees/ha), but Picea becomes dominant after 150-200 years since Abies is shorter lived. (4) Without disturbance the forest develops into a pure coniferous canopy (BA 40-50 m2/ha) with a self-regenerating density of 1,000 coniferous canopy trees/ha. There is no collapse of old-growth stands. The dark taiga may serve as an example in which a limited set to tree species may gain dominance under certain disturbance conditions without ever getting monotypic.

Children and adolescents with chronic cerebellar lesions show no clinically relevant signs of aphasia or neglect.

We studied language and visuospatial functions of 12 children and adolescents who had undergone surgery for cerebellar astrocytoma without subsequent radiation or chemotherapy and compared them with 27 age-, gender-, and education-matched healthy control subjects. To study possible lateralization of the functions of the left and right cerebellar hemispheres, subjects performed several language tasks including a verb-generation task as well as standard neglect and extinction tests. Three-dimensional-MR images confirmed that lesions affected cerebellar hemispheres in all children but one who had a pure vermal lesion. The right cerebellar hemisphere was affected in six, the left hemisphere in four children, and both hemispheres in one child. There were no signs of aphasia in the children or adolescents with cerebellar lesions. Language abilities did not differ between cerebellar patients and control subjects except for small increases in reaction times in verb generation in patients with left-sided lesions. Visuospatial functions were also intact in cerebellar subjects except for minor group differences in neglect tasks. In sum, chronic focal cerebellar lesions acquired in childhood or youth do not result in persistent language disorders or clinically significant signs of spatial neglect or extinction.

Incidence of dysarthria in children with cerebellar tumors: a prospective study.

The present study investigated dysarthric symptoms in children with cerebellar tumors. Ten children with cerebellar tumors and 10 orthopedic control children were tested prior and one week after surgery. Clinical dysarthric symptoms were quantified in spontaneous speech. Syllable durations were analyzed in syllable repetition and sentence production tasks. Localization of the cerebellar lesions were defined after manual transfer from individual 2D-MR images onto 3D images of a spatially normalized healthy brain. Cerebellar children showed few and mild clinical signs of dysarthria. No difference was present in the sentence production task compared to controls. In five cerebellar children, syllables were prolonged in the syllable repetition task after surgery. Syllable duration normalized in an additional four-week session in all but one case. The MR-analysis showed that superior paravermal cerebellar areas likely involved in dysarthria in adults (paravermal lobules HVI, Crus I) were not significantly affected. In children, speech impairments appear to be rare after cerebellar surgery because tumors most commonly affect posterior-inferior and medial parts of the cerebellum while critical cerebellar regions are likely spared. The results suggest a similar localization of speech functions in the cerebellum in children and adults.

Cerebellar mutism--report of four cases.

The aim of the present study was to investigate the manifestations of mutism after surgery in children with cerebellar tumors. Speech impairment following cerebellar mutism in children was investigated based on standardized acoustic speech parameters and perceptual criteria. Mutistic and non-mutistic children after cerebellar surgery as well as orthopedic controls were tested pre-and postoperatively. Speech impairment was compared with the localization of cerebellar lesions (i. e. affected lobules and nuclei). Whereas both control groups showed no abnormalities in speech and behavior, the mutistic group could be divided into children with dysarthria in post mutistic phase and children with mainly behavioral disturbances. In the mutistic children involvement of dentate and fastigial nuclei tended to be more frequent and extended than in the nonmutistic cerebellar children. Cerebellar mutism is a complex phenomenon of at least two types. Dysarthric symptoms during resolution of mutism support the anarthria hypothesis, while mainly behavioral changes suggest an explanation independent from speech motor control.

Preserved verb generation in patients with cerebellar atrophy.

A role of the right cerebellar hemisphere has been suggested in linguistic functions. Nevertheless, studies of verb generation in cerebellar patients provide inconsistent results. The aim of the present study was to examine verb generation in a larger group of cerebellar patients with well-defined lesions. Ten subjects with degenerative cerebellar disorders and ten healthy matched controls participated. Subjects had to generate verbs to the blocked presentation of photographs of objects (i.e. four blocks of sixteen objects). As control condition, the objects had to be named. Furthermore, dysarthria was quantified by means of a sentence production and syllable repetition task. Volumetric analysis of individual 3D-MR scans was performed to quantify cerebellar atrophy. Cerebellar patients were slower in the sentence production and syllable repetition tasks, and cerebellar volume was decreased compared to controls. Despite cerebellar atrophy and dysarthria, the answers produced did not differ between patients and controls. In addition, both groups revealed the same amount of decrease in verbal reaction time over blocks (i.e. learning). The results suggest that the role of the cerebellum in verb generation is less pronounced than previously suggested.

[Intrastomal refractive surgery with ultra-short laser pulses. Results from initial in vitro experiments]. / Intrastromale refraktive Chirurgie mit ultrakurzen Laserpulsen Ergebnisse erster In-vitro-Experimente.

PURPOSE: To investigate the possibilities and techniques for intrastromal ablation of the cornea by the use of ultra-short laser pulses. METHOD: A laser-induced plasma with a diameter of 8 mu was generated 100-300 mu below Bowmans membrane by focussing of a Ti:Saphir laser (lambda=805 nm, pulse width: 115 fs, energy: 0.6-3.3 microJ). Scanning the laser beam enabled arbitrary transsections in the corneal stroma. All experiments were performed in porcine eyes 1-4 h post-mortem. RESULTS: Two-dimensional sections were achieved applying a minimal laser energy of 0.6 microJ at a separation of the single laser effects of 10 micrometer. A 150 micrometer thick disc was excised 150 micrometer below Bowmans membrane and extracted through a keratotomy performed by the laser. Sharp-cut edges were observed by slit-lamp biomicroscopy. CONCLUSIONS: Ultra-short laser pulses are suitable for precise intrastromal ablation.

[The Werther effect. Significance, mechanisms, consequences]. / Der Werther-Effekt. Bedeutung, Mechanismen, Konsequenzen.

The Werther effect is a highly regarded phenomenon in media effect research. Since the trail-blazing studies conducted by the American sociologist Phillips, there have been a great many attempts to quantify and evaluate imitative deeds that follow genuine suicides and apparent attempts at suicide. This paper starts by tracing the milestones along the way of research into the Werther effect. The concrete imitation patterns following suicides are then discussed, and the implications for responsible journalistic reporting that arise out of them are presented. This seems to be necessary, since despite many-sided and detailed findings on the Werther effect in Germany, there have so far been no experiments devoted to ways of exploiting these research results practically in a suicide prevention programme. Whilst in other countries preliminary guidelines for journalistic reporting have already been elaborated and in some countries even implemented, such efforts are still only in the very early stages in Germany.

Plasma volume expansion in early pregnancy.

OBJECTIVE: To determine the time course of plasma volume expansion in early pregnancy. METHODS: We prospectively measured plasma volume by Evans blue dye dilution during the menstrual (cycle day 2--3), follicular (cycle day 9--10), and luteal phases (cycle day urinary leutinizing hormone [LH] surge plus 9--10) of the menstrual cycle and at three additional time points (LH surge + 16 days, LH surge + 28 days, and LH surge + 70 days) in women achieving pregnancy. Twenty-one subjects were examined during 38 menstrual cycles to establish baseline menstrual cycle data. Ten subjects conceived within 1 year of menstrual cycle studies. All ten pregnancies were viable and reached the third trimester. Analyses used repeated-measures analysis of variance with P <.05 accepted for significance. RESULTS: Mean plasma volume was found to change significantly across the period of observation (P <.008) in those who conceived. Plasma volume at LH surge + 70 days (12 menstrual weeks, 2320 +/- 280 mL) was greater than either menstrual cycle estimates or early pregnancy estimates of plasma volume. There was no difference in plasma volume at LH surge + 16 days (2077 +/- 288 mL) or LH surge + 28 days (2010 +/- 271 mL) compared with menstrual cycle measurements during the menstrual phase (2156 +/- 292 mL), follicular phase (2036 +/- 280 mL), and luteal phase (2120 +/- 425 mL). There was no significant difference between those who conceived and those who did not in their mean menstrual cycle plasma volume. CONCLUSION: Plasma volume expansion in early human pregnancy cannot be identified until after the sixth menstrual week. By 12 menstrual weeks, plasma volume has expanded by approximately 14% +/- 12% (mean +/- SD) over follicular phase measurements.