Indications of a link between seismotectonics and CH4 release from seeps off Costa Rica

Measurements of CH4 concentrations in the bottom water during two discrete sampling periods in subsequent years above different cold seeps at the Pacific margin off Costa Rica indicate large-scale variations of CH4 release. CH4 is emitted from mud extrusions and a slide scar at 1000–2300 m water depth. Maximum CH4 concentrations were found to be lower above all investigated sites in autumn 2003 than in autumn 2002 although seep sites are up to 300 km apart. Tidal and current changes were observed but found to apply only to individual seep sites. Increased seismic activity connected to the moment magnitude (M W ) 6.4 earthquake offshore Costa Rica in June 2002 could have had an impact on all seep sites and thereby caused an increase in CH4 emission. This is supported by the largest variations of CH4 concentration found above mud extrusions located above faults likely more strongly affected by tectonic movements. Even though our data indicate a relation between seismicity and CH4 seepage, the relation is not proven, and future work is needed to comprehensively test this hypothesis

Immobilien. Teil I: Zukünftige Entwicklungen auf den Wohnungsmärkten in Deutschland. Teil II: Das Mehrfamilienhaus als Kapitalanlage – mit besonderer Berücksichtigung des Standortes Hamburg

Die Entwicklung der Immobilienmärkte ist eng mit der regionalen demographischen Entwicklung verknüpft. So werden regionale Unterschiede in der Bevölkerungsentwicklung zu erheblich differierenden Entwicklungen auf den regionalen Immobilienmärkten führen. Die Studie zeigt, wie sich die Märkte für Wohnimmobilien unter den Bedingungen demographischer Veränderungen anpassen werden. Dazu werden zunächst die zentralen Determinanten des Angebots und der Nachfrage nach Wohnraum diskutiert

Wearable sensors objectively measure gait parameters in Parkinson's disease

Distinct gait characteristics like short steps and shuffling gait are prototypical signs commonly observed in Parkinson's disease. Routinely assessed by observation through clinicians, gait is rated as part of categorical clinical scores. There is an increasing need to provide quantitative measurements of gait, e.g. to provide detailed information about disease progression. Recently, we developed a wearable sensor-based gait analysis system as diagnostic tool that objectively assesses gait parameter in Parkinson's disease without the need of having a specialized gait laboratory. This system consists of inertial sensor units attached laterally to both shoes. The computed target of measures are spatiotemporal gait parameters including stride length and time, stance phase time, heel-strike and toe-off angle, toe clearance, and inter-stride variation from gait sequences. To translate this prototype into medical care, we conducted a cross-sectional study including 190 Parkinson's disease patients and 101 age-matched controls and measured gait characteristics during a 4x10 meter walk at the subjects' preferred speed. To determine intraindividual changes in gait, we monitored the gait characteristics of 63 patients longitudinally. Cross-sectional analysis revealed distinct spatiotemporal gait parameter differences reflecting typical Parkinson's disease gait characteristics including short steps, shuffling gait, and postural instability specific for different disease stages and levels of motor impairment. The longitudinal analysis revealed that gait parameters were sensitive to changes by mirroring the progressive nature of Parkinson's disease and corresponded to physician ratings. Taken together, we successfully show that wearable sensor-based gait analysis reaches clinical applicability providing a high biomechanical resolution for gait impairment in Parkinson's disease. These data demonstrate the feasibility and applicability of objective wearable sensor-based gait measurement in Parkinson's disease reaching high technological readiness levels for both, large scale clinical studies and individual patient care

Swing time variation is increased in PD patients with increased postural instability.

<p>Swing time variation is unchanged when grouped according to H&Y disease stage (A). PD patients with higher postural instability, as identified by a rating of the single item "postural stability" of the UPDRS-III, show increased swing time variation (B). Group data are displayed as mean ± SEM. and compared using one-way ANOVA followed by Bonferroni’s post-hoc test. *p < 0.05.</p

Measures of short steps in PD patients and controls (cross-sectional study).

<p>Stride length, gait velocity, stride time, stance phase, and swing phase time were calculated for controls and PD patients grouped according to H&Y disease stage (A), UPDRS-III total score (B), and the single item "gait" of the UPDRS-III (C). Group data are displayed as mean ± SEM. and compared using one-way ANOVA followed by Bonferroni’s post-hoc test. *p < 0.05.</p

Clinical characteristics of PD patients and healthy controls.

<p>Clinical characteristics of PD patients and healthy controls.</p