17 research outputs found
Weight loss reduces head motion: Re-visiting a major confound in neuroimaging
Head motion during magnetic resonance imaging (MRI) induces image artifacts that affect virtually every brain measure. In parallel, cross‐sectional observations indicate a correlation of head motion with age, psychiatric disease status and obesity, raising the possibility of a systematic artifact‐induced bias in neuroimaging outcomes in these conditions, due to the differences in head motion. Yet, a causal link between obesity and head motion has not been tested in an experimental design. Here, we show that a change in body mass index (BMI) (i.e., weight loss after bariatric surgery) systematically decreases head motion during MRI. In this setting, reduced imaging artifacts due to lower head motion might result in biased estimates of neural differences induced by changes in BMI. Overall, our finding urges the need to rigorously control for head motion during MRI to enable valid results of neuroimaging outcomes in populations that differ in head motion due to obesity or other conditions
Tetrathiotetracene thin film morphology and electrical properties
The electrical properties of organic thin films are determined by their chemical constituents and the morphology of the films deposited. In this paper the morphology of vacuum sublimed (7∙10-6 mbar) tetrathiotetracene (TTT) thin films is shown to be strongly affected by the thermal deposition temperature (222-350 K) and rate of deposition. Mostly needle-like morphologies are identified by scanning electron microscopy. Optimal TTT purity (a pre-requisite for device preparation via subsequent oxidation) is evidenced by their initially low electrical conductivity. Altering the TTT morphology, by variation of the evaporation parameters, strongly affects this base electrical conductivity. Four probe conductivity measurements and charge extraction by linear increasing voltage methods are used to characterize film electrical properties. In-plane conductivity of up to 7.03∙10-5 S/cm is achieved for pure TTT thin films. Subsequent aerial oxidation resulted in a 3.4-fold increase in electrical conductivity
Weight loss reduces head motion: Revisiting a major confound in neuroimaging
Head motion during magnetic resonance imaging (MRI) induces image artifacts that affect virtually every brain measure. In parallel, cross‐sectional observations indicate a correlation of head motion with age, psychiatric disease status and obesity, raising the possibility of a systematic artifact‐induced bias in neuroimaging outcomes in these conditions, due to the differences in head motion. Yet, a causal link between obesity and head motion has not been tested in an experimental design. Here, we show that a change in body mass index (BMI) (i.e., weight loss after bariatric surgery) systematically decreases head motion during MRI. In this setting, reduced imaging artifacts due to lower head motion might result in biased estimates of neural differences induced by changes in BMI. Overall, our finding urges the need to rigorously control for head motion during MRI to enable valid results of neuroimaging outcomes in populations that differ in head motion due to obesity or other conditions
Resumes of the Bird Mission
The DLR micro satellite BIRD (Bi-Spectral Infra Red Detection)was the Indian Polar Satellite Launch Vehicle PSLV-C3 into a 570 km ciracular sun-synchronous orbit on 22 October 2001. The BIRD mission, fully funded by the DLR, answers topical technologal and scientific questions related to the operation of a compact infra-red push-broom sensor system on board of a micro satellite and demonstrates a new spacecraft bus technologies. BIRD mission control is conducted by DLR/GSOC in Oberpfaffenhofen commanding, data reception and data processing is performed via ground stations in Weilheim and Neustrelitz (Germany). The BIRD mission is a demonstrator for small satellite projects dedicated to the hazard detection and monitoring. In the year 2003 BIRD has been used in the ESA project FUEGOSAT to demonstrate the utilisation of innovative space technologies for fire risk management