52 research outputs found
Visuelle Medien und die (Wieder-)Herstellung von Unmittelbarkeit
Die Verfasser argumentieren, dass bei aller berechtigten Skepsis gegenĂŒber visuellen Medien die ethnografische Forschung pragmatisch auf sie zurĂŒckgreifen muss. Als empirisch fundierte Forschung lĂ€sst sie sich von der Teilnahme an sozialen Praktiken leiten und irritieren und ist dafĂŒr auf Importe aus den untersuchten Feldern und ihren Praktiken angewiesen. An zwei Fallbeispielen aus der soziologischen Praxisforschung wird gezeigt, dass der Einsatz von visuellen Medien als Vermittlern konzeptuell und vor allem praktisch voraussetzungsvoll ist. Der Einsatz von visuellen Medien setzt die Anreicherung des generierten Datenmaterials mit in der Praxis erworbenem bzw. erfahrenem Kontext- und Wahrnehmungswissen durch den Ethnografen voraus, damit dieses als Dokument in der wissenschaftlichen Praxis funktioniert. Die Art zu sehen, die der Forscher im Feld gelernt hat, muss er dem Betrachter seiner Bilder vermitteln. Erst so kann Unmittelbarkeit zwischen der Forschergruppe und dem Bildmaterial entstehen - und es kann Teil der ethnografischen Praxis werden. (entnommen aus Sowiport.de
IncP âtype plasmids carrying genes for antibiotic resistance or for aromatic compound degradation are prevalent in sequenced Aromatoleum and Thauera strains
Self-transferable plasmids of the incompatibility group P-1 (IncP-1) are considered important carriers of genes for antibiotic resistance and other adaptive functions. In the laboratory, these plasmids have a broad host range; however, little is known about their in situ host profile. In this study, we discovered that Thauera aromatica K172T, a facultative denitrifying microorganism capable of degrading various aromatic compounds, contains a plasmid highly similar to the IncP-1 Δ archetype pKJK5. The plasmid harbours multiple antibiotic resistance genes and is maintained in strain K172T for at least 1000 generations without selection pressure from antibiotics. In a subsequent search, we found additional nine IncP-type plasmids in a total of 40 sequenced genomes of the closely related genera Aromatoleum and Thauera. Six of these plasmids form a novel IncP-1 subgroup designated Ξ, four of which carry genes for anaerobic or aerobic degradation of aromatic compounds. Pentanucleotide sequence analyses (k-mer profiling) indicated that Aromatoleum spp. and Thauera spp. are among the most suitable hosts for the Ξ plasmids. Our results highlight the importance of IncP-1 plasmids for the genetic adaptation of these common facultative denitrifying bacteria, and provide novel insights into the in situ host profile of these plasmids
TotalSegmentator: robust segmentation of 104 anatomical structures in CT images
We present a deep learning segmentation model that can automatically and
robustly segment all major anatomical structures in body CT images. In this
retrospective study, 1204 CT examinations (from the years 2012, 2016, and 2020)
were used to segment 104 anatomical structures (27 organs, 59 bones, 10
muscles, 8 vessels) relevant for use cases such as organ volumetry, disease
characterization, and surgical or radiotherapy planning. The CT images were
randomly sampled from routine clinical studies and thus represent a real-world
dataset (different ages, pathologies, scanners, body parts, sequences, and
sites). The authors trained an nnU-Net segmentation algorithm on this dataset
and calculated Dice similarity coefficients (Dice) to evaluate the model's
performance. The trained algorithm was applied to a second dataset of 4004
whole-body CT examinations to investigate age dependent volume and attenuation
changes. The proposed model showed a high Dice score (0.943) on the test set,
which included a wide range of clinical data with major pathologies. The model
significantly outperformed another publicly available segmentation model on a
separate dataset (Dice score, 0.932 versus 0.871, respectively). The aging
study demonstrated significant correlations between age and volume and mean
attenuation for a variety of organ groups (e.g., age and aortic volume; age and
mean attenuation of the autochthonous dorsal musculature). The developed model
enables robust and accurate segmentation of 104 anatomical structures. The
annotated dataset (https://doi.org/10.5281/zenodo.6802613) and toolkit
(https://www.github.com/wasserth/TotalSegmentator) are publicly available.Comment: Accepted at Radiology: Artificial Intelligenc
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XUV double-pulses with femtosecond to 650 ps separation from a multilayer-mirror-based split-and-delay unit at FLASH
Extreme ultraviolet (XUV) and X-ray free-electron lasers enable new scientific opportunities. Their ultra-intense coherent femtosecond pulses give unprecedented access to the structure of undepositable nanoscale objects and to transient states of highly excited matter. In order to probe the ultrafast complex light-induced dynamics on the relevant time scales, the multi-purpose end-station CAMP at the free-electron laser FLASH has been complemented by the novel multilayer-mirror-based split-and-delay unit DESC (DElay Stage for CAMP) for time-resolved experiments. XUV double-pulses with delays adjustable from zero femtoseconds up to 650â
picoseconds are generated by reflecting under near-normal incidence, exceeding the time range accessible with existing XUV split-and-delay units. Procedures to establish temporal and spatial overlap of the two pulses in CAMP are presented, with emphasis on the optimization of the spatial overlap at long time-delays via time-dependent features, for example in ion spectra of atomic clusters
Soft X-ray spectroscopy as a probe for gas-phase protein structure:Electron impact ionization from within
Preservation of protein conformation upon transfer into the gasâphase is key for structure determination of free single molecules, e.g. using Xâray freeâelectron lasers. In the gas phase, the helicity of melittin decreases strongly as the protein's protonation state increases. We demonstrate the sensitivity of soft Xâray spectroscopy to the gas phase conformation of melittin cations ([melittin+qH]q+, q=2â4) in a cryogenic linear radiofrequency ion trap. With increasing helicity we observe a decrease of the dominating carbon 1sâï°* transition in the amide C=O bonds for nonâdissociative single ionization and an increase for nonâdissociative double ionization. As the underlying mechanism we identify inelastic electron scattering. Using an independent atom model we show that the more compact nature of the helical protein conformation substantially increases the probability for offâsite intramolecular ionization by inelastic Auger electron scattering
Radiotherapy Versus Inguinofemoral Lymphadenectomy as Treatment for Vulvar Cancer Patients With Micrometastases in the Sentinel Node: Results of GROINSS-V II
PURPOSE:
The Groningen International Study on Sentinel nodes in Vulvar cancer (GROINSS-V)-II investigated whether inguinofemoral radiotherapy is a safe alternative to inguinofemoral lymphadenectomy (IFL) in vulvar cancer patients with a metastatic sentinel node (SN).
METHODS:
GROINSS-V-II was a prospective multicenter phase-II single-arm treatment trial, including patients with early-stage vulvar cancer (diameter < 4 cm) without signs of lymph node involvement at imaging, who had primary surgical treatment (local excision with SN biopsy). Where the SN was involved (metastasis of any size), inguinofemoral radiotherapy was given (50 Gy). The primary end point was isolated groin recurrence rate at 24 months. Stopping rules were defined for the occurrence of groin recurrences.
RESULTS:
From December 2005 until October 2016, 1,535 eligible patients were registered. The SN showed metastasis in 322 (21.0%) patients. In June 2010, with 91 SN-positive patients included, the stopping rule was activated because the isolated groin recurrence rate in this group went above our predefined threshold. Among 10 patients with an isolated groin recurrence, nine had SN metastases > 2 mm and/or extracapsular spread. The protocol was amended so that those with SN macrometastases (> 2 mm) underwent standard of care (IFL), whereas patients with SN micrometastases (†2 mm) continued to receive inguinofemoral radiotherapy. Among 160 patients with SN micrometastases, 126 received inguinofemoral radiotherapy, with an ipsilateral isolated groin recurrence rate at 2 years of 1.6%. Among 162 patients with SN macrometastases, the isolated groin recurrence rate at 2 years was 22% in those who underwent radiotherapy, and 6.9% in those who underwent IFL (P = .011). Treatment-related morbidity after radiotherapy was less frequent compared with IFL.
CONCLUSION:
Inguinofemoral radiotherapy is a safe alternative for IFL in patients with SN micrometastases, with minimal morbidity. For patients with SN macrometastasis, radiotherapy with a total dose of 50 Gy resulted in more isolated groin recurrences compared with IFL
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