Active shape oscillations of giant vesicles with cyclic closure and opening of membrane necks

Reaction-diffusion systems encapsulated within giant unilamellar vesicles (GUVs) can lead to shape oscillations of these vesicles as recently observed for the bacterial Min protein system. This system contains two Min proteins, MinD and MinE, which periodically attach to and detach from the GUV membranes, with the detachment being driven by ATP hydrolysis. Here, we address these shape oscillations within the theoretical framework of curvature elasticity and show that they can be understood in terms of a spontaneous curvature that changes periodically with time. We focus on the simplest case provided by a attachment–detachment kinetics that is laterally uniform along the membrane. During each oscillation cycle, the vesicle shape is transformed from a symmetric dumbbell with two subcompartments of equal size to an asymmetric dumbbell with two subcompartments of different size, followed by the reverse, symmetry-restoring transformation. This sequence of shapes is first analyzed within the spontaneous curvature model which is then extended to the area-difference-elasticity model by decomposing the spontaneous curvature into a local and nonlocal component. For both symmetric and asymmetric dumbbells, the two subcompartments are connected by a narrow membrane neck with a circular waistline. The radius of this waistline undergoes periodic oscillations, the time dependence of which can be reasonably well fitted by a single Fourier mode with an average time period of 56 s

Herpes zoster-associated trigeminal trophic syndrome: a case report and review

Litschel R, Winkler H, Dazert S, Sudhoff H. Herpes zoster-associated trigeminal trophic syndrome: a case report and review. European Archives of Oto-Rhino-Laryngology. 2003;260(2):86-90

Beating vesicles: Encapsulated protein oscillations cause dynamic membrane deformations

The bacterial Min protein system was encapsulated in giant unilamellar vesicles (GUVs). Using confocal fluorescence microscopy, we identified several distinct modes of spatiotemporal patterns inside spherical GUVs. For osmotically deflated GUVs, the vesicle shape actively changed in concert with the Min oscillations. The periodic relocation of Min proteins from the vesicle lumen to the membrane and back is accompanied by drastic changes in the mechanical properties of the lipid bilayer. In particular, two types of oscillating membrane‐shape changes are highlighted: 1) GUVs that repeatedly undergo fission into two connected compartments and fusion of these compartments back into a dumbbell shape and 2) GUVs that show periodic budding and subsequent merging of the buds with the mother vesicle, accompanied by an overall shape change of the vesicle reminiscent of a bouncing ball. These findings demonstrate how reaction–diffusion‐based protein self‐organization can directly yield visible mechanical effects on membrane compartments, even up to autonomous division, without the need for coupling to cytoskeletal elements

Eye tracker based study: Perception of faces with a cleft lip and nose deformity

Item does not contain fulltextAIM: Quantification of visual attention directed towards cleft stigmata and its impact on the perception of selected personality traits. METHODS: Forty observers were divided into two groups and their visual scan paths were recorded. Both groups observed a series of photographs displaying full frontal views of the faces of 18 adult patients with clefts, nine with residual cleft stigmata and nine with digitally-corrected stigmata (each patient only appeared once per series). Patients that appeared with residual stigmata in one series appeared digitally corrected in the other series and vice versa. Visual fixation times on the upper lip and nose were compared between the original and corrected photographs. Observers subsequently rated personality traits as perceived using visual analogue scales and the same photographs that they had observed in the series. RESULTS: In faces depicting cleft stigmata observers spent more time looking at the oronasal region of interest, followed by the eyes (39.6%; SD 5.0 and 35.1%; SD 3.6, respectively, p = 0.0198). Observers spent more time looking at the cleft lip compared with the corrected lip (21.2%; SD 4.0 and 16.7%; SD 5.0, respectively, p = 0.006). The differences between questionnaire scores for faces with cleft stigmata compared with faces with corrected stigmata for withdrawn-sociable, discontent-content, lazy-assiduous, unimaginative-creative, unlikeable-likeable, and the sum of individual personality traits were not significant. CONCLUSION: According to these findings, cleft lip and cleft nose have an attention-drawing potential with the cleft lip being the major attention drawing factor. These data do not provide supportive evidence for the notion reported in literature that patients with clefts are perceived as having negative personality traits

Dysphonie und Dysphagie nach anterioren Zugängen zur Halswirbelsäule

Hintergrund: Der anteriore Zugang zur Halswirbelsäule ist ein Standardverfahren der Wirbelsäulenchirurgie. Postoperative Stimm- und Schluckstörungen sind bekannte Komplikationen. Ziel der Studie war es, deren Häufigkeit und Verlauf zu evaluieren. Methoden: Es wurden prospektiv Patienten eingeschlossen, die an der Klinik für Neurochirurgie am Kantonsspital St. Gallen vom 01.03.2010–28.02.2011 mittels anteriorem Zugang an der Halswirbelsäule operiert wurden. Die Evaluation erfolgte mittels Laryngoskopie, fiberoptische endoskopische Evaluation des Schluckens (FEES), Stimmfeldmessung und validierten Fragebögen. Ergebnisse: Von 53 in die Studie eingeschlossenen Patienten konnten 40 auch im Verlauf untersucht werden. Die Häufigkeit einer postoperativen Dysphonie aufgrund einer Rekurrensparese war 4/40 (10 %), wobei sich 3 davon erholten. Pathologische Schluckuntersuchungen fanden sich postoperativ bei 7/37 (18,9 %) der Patienten. Der Wert im Swal-QoL (Swallowing Quality of Life Questionnaire) war postoperativ signifikant niedriger. Schlussfolgerung: Die meist temporäre Rekurrensparese ist mit einer Häufigkeit von 10 % eine relevante Komplikation. Postoperative Schluckstörungen sind häufig und sollten in der postoperativen Betreuung evaluiert und therapiert werden. BACKGROUND: Anterior cervical spine surgery is a common procedure for fusions and/or discectomies. Postoperative dysphonia and dysphagia are known complications. In this study, we examined the frequency and outcomes of these complications in this patient population. MATERIALS AND METHODS: Patients planned to receive anterior cervical spine surgery between 01.03.2010 and 28.02.2011 at the Department of Neurosurgery, St. Gallen were prospectively included. Patients were evaluated using laryngoscopy, fiberoptic endoscopic evaluation of swallowing (FEES), voice field measurements and validated questionnaires. RESULTS: From the 53 patients included in the study, 40 had at least one complete follow-up examination. The frequency of postoperative dysphonia due to recurrent nerve palsy was 4/40 (10 %), although this was temporary in 3 patients. FEES revealed a pathological result in 18.9 % of patients. Postoperative Swallowing Quality of Life Questionnaire (Swal-QoL) scores were significantly lower. CONCLUSION: At a frequency of 10 %, dysphonia due to recurrent nerve palsy is a relevant complication in cervical spine surgery, albeit temporary in most cases. Postoperative dysphagia is common and should be evaluated and treated during follow-up

Entwicklung eines optischen Systems fuer hochaufloesende Fernsehkameras Abschlussbericht

Available from TIB Hannover: F94B1448+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman