University of Cologne

About: University of Cologne is a education organization based out in Cologne, Germany. It is known for research contribution in the topics: Population & Gene. The organization has 32050 authors who have published 66350 publications receiving 2210092 citations. The organization is also known as: Universität zu Köln & Universitatis Coloniensis.

An Interactive Technique for Three-Dimensional Image Registration: Validation for PET, SPECT, MRI and CT Brain Studies

Abstract: 0.32to 2.22 mm (a.d.)and of rotationangles from0.32 to 1.70 degrees. ft was always much smaller than the point-spreed full-widthhalf maximum of the device with the lower resolution. The accuracyof coregistration was examinedusingtwo arbi tredlymiep@ced imagesets.Inter1nd@dUal andintraindMdual variance were similar, which suggested that the influence of subjectivity was not significant. Average displacements after coregistration were 0.43 and 0.29 mm or less for PET and MRI data, respectively, which indicated the absence of a systematic bias. Conclusion: The results indicate the high reproducibility and accuracy ofthus three-dimenalonal coreg@trationtethnk@ue, which is comparable or superior to those of automated tech niquesand methodsbased on externalartificiallandmarks.

First results from the Giotto magnetometer experiment at comet Halley

Abstract: The Giotto magnetometer experiment at comet Halley has for the first time provided magnetic field measurements in all the important spatial regions characterizing the front-side interaction between the solar-wind magnetoplasma and a cometary atmosphere. Upstream waves of cometary origin have been observed at distances greater than two million km from the comet, both inbound and outbound. A cometary bow shock has been identified at 1.15 million inbound on the dawn side and a thick quasi-parallel cometary bow shock outbound. A turbulent magnetosheath has been observed further inside. A magnetic pile-up region has been identified inside 135,000 km, inbound, and 263,000 km, outbound, with fields up to 57 and 65 nT, respectively. A cavity region with essentially zero magnetic field has been discovered, with a width of 8500 km along the trajectory around closest approach.

Engraftment of engineered ES cell–derived cardiomyocytes but not BM cells restores contractile function to the infarcted myocardium

Abstract: Cellular cardiomyoplasty is an attractive option for the treatment of severe heart failure. It is, however, still unclear and controversial which is the most promising cell source. Therefore, we investigated and examined the fate and functional impact of bone marrow (BM) cells and embryonic stem cell (ES cell)-derived cardiomyocytes after transplantation into the infarcted mouse heart. This proved particularly challenging for the ES cells, as their enrichment into cardiomyocytes and their long-term engraftment and tumorigenicity are still poorly understood. We generated transgenic ES cells expressing puromycin resistance and enhanced green fluorescent protein cassettes under control of a cardiac-specific promoter. Puromycin selection resulted in a highly purified (>99%) cardiomyocyte population, and the yield of cardiomyocytes increased 6-10-fold because of induction of proliferation on purification. Long-term engraftment (4-5 months) was observed when co-transplanting selected ES cell-derived cardiomyocytes and fibroblasts into the injured heart of syngeneic mice, and no teratoma formation was found (n = 60). Although transplantation of ES cell-derived cardiomyocytes improved heart function, BM cells had no positive effects. Furthermore, no contribution of BM cells to cardiac, endothelial, or smooth muscle neogenesis was detected. Hence, our results demonstrate that ES-based cell therapy is a promising approach for the treatment of impaired myocardial function and provides better results than BM-derived cells.

The genomes of two key bumblebee species with primitive eusocial organization

Abstract: The shift from solitary to social behavior is one of the major evolutionary transitions Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation