59 research outputs found
CLAIRE -- Parallelized Diffeomorphic Image Registration for Large-Scale Biomedical Imaging Applications
We study the performance of CLAIRE -- a diffeomorphic multi-node, multi-GPU
image-registration algorithm, and software -- in large-scale biomedical imaging
applications with billions of voxels. At such resolutions, most existing
software packages for diffeomorphic image registration are prohibitively
expensive. As a result, practitioners first significantly downsample the
original images and then register them using existing tools. Our main
contribution is an extensive analysis of the impact of downsampling on
registration performance. We study this impact by comparing full-resolution
registrations obtained with CLAIRE to lower-resolution registrations for
synthetic and real-world imaging datasets. Our results suggest that
registration at full resolution can yield a superior registration quality --
but not always. For example, downsampling a synthetic image from to
decreases the Dice coefficient from 92% to 79%. However, the
differences are less pronounced for noisy or low-contrast high-resolution
images. CLAIRE allows us not only to register images of clinically relevant
size in a few seconds but also to register images at unprecedented resolution
in a reasonable time. The highest resolution considered is CLARITY images of
size . To the best of our knowledge, this is the
first study on image registration quality at such resolutions.Comment: 32 pages, 9 tables, 8 figure
Failure of catecholamines to shift T-cell cytokine responses toward a Th2 profile in patients with rheumatoid arthritis
To further understand the role of neuro-immunological interactions in the pathogenesis of rheumatoid arthritis (RA), we studied the influence of sympathetic neurotransmitters on cytokine production of T cells in patients with RA. T cells were isolated from peripheral blood of RA patients or healthy donors (HDs), and stimulated via CD3 and CD28. Co-incubation was carried out with epinephrine or norepinephrine in concentrations ranging from 10(-5 )M to 10(-11 )M. Interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-4, and IL-10 were determined in the culture supernatant with enzyme-linked immunosorbent assay. In addition, IFN-γ and IL-10 were evaluated with intracellular cytokine staining. Furthermore, basal and agonist-induced cAMP levels and catecholamine-induced apoptosis of T cells were measured. Catecholamines inhibited the synthesis of IFN-γ, TNF-α, and IL-10 at a concentration of 10(-5 )M. In addition, IFN-γ release was suppressed by 10(-7 )M epinephrine. Lower catecholamine concentrations exerted no significant effect. A reduced IL-4 production upon co-incubation with 10(-5 )M epinephrine was observed in RA patients only. The inhibitory effect of catecholamines on IFN-γ production was lower in RA patients as compared with HDs. In RA patients, a catecholamine-induced shift toward a Th2 (type 2) polarised cytokine profile was abrogated. Evaluation of intracellular cytokines revealed that CD8-positive T cells were accountable for the impaired catecholaminergic control of IFN-γ production. The highly significant negative correlation between age and catecholamine effects in HDs was not found in RA patients. Basal and stimulated cAMP levels in T-cell subsets and catecholamine-induced apoptosis did not differ between RA patients and HDs. RA patients demonstrate an impaired inhibitory effect of catecholamines on IFN-γ production together with a failure to induce a shift of T-cell cytokine responses toward a Th2-like profile. Such an unfavorable situation is a perpetuating factor for inflammation
Complication rates of peripherally inserted central catheters vs implanted ports in patients receiving systemic anticancer therapy: A retrospective cohort study
While implanted port catheters ("PORTs") have historically been the standard device for intravenous systemic anticancer therapy, the use of peripherally inserted central catheters (PICCs) has increased continuously and reliable catheter selection guidelines are lacking. We compare complication rates of PORTs and PICCs in cancer treatment in a retrospective study of 3365 patients with both solid organ (n = 2612) and hematologic (n = 753) malignancies, between 2001 and 2021. 26.4% (n = 890) of all patients were treated via PICCs and 73.6% (2475) via PORTs. 20.7% (578) experienced a major catheter-related complication with a higher rate in PICCs than in PORTs (23.5% vs 14.9%, P < .001). Among major complications, infections and mechanical complications were more common in PICCs than in PORTs (11.9% vs 6.4%, P = .001, 7.3% vs 4.2%, P = .002), whereas the rate of thrombosis was similar (3.4% vs 3.0%, P = .9). While PORTs had a higher rate of periprocedural complications (2.7% vs 1.1%, P < .05), PICCs overall complication rate exceeded PORTs within 3 days from implantation. Median follow-up was 49 (PICC) and 60 weeks (PORT). PORTs are safer and therefore should be preferred in this setting regardless of catheter dwell time
Reported barriers to evaluation in chronic care: experiences in six European countries.
INTRODUCTION: The growing movement of innovative approaches to chronic disease management in Europe has not been matched by a corresponding effort to evaluate them. This paper discusses challenges to evaluation of chronic disease management as reported by experts in six European countries. METHODS: We conducted 42 semi-structured interviews with key informants from Austria, Denmark, France, Germany, The Netherlands and Spain involved in decision-making and implementation of chronic disease management approaches. Interviews were complemented by a survey on approaches to chronic disease management in each country. Finally two project teams (France and the Netherlands) conducted in-depth case studies on various aspects of chronic care evaluation. RESULTS: We identified three common challenges to evaluation of chronic disease management approaches: (1) a lack of evaluation culture and related shortage of capacity; (2) reluctance of payers or providers to engage in evaluation and (3) practical challenges around data and the heterogeity of IT infrastructure. The ability to evaluate chronic disease management interventions is influenced by contextual and cultural factors. CONCLUSIONS: This study contributes to our understanding of some of the most common underlying barriers to chronic care evaluation by highlighting the views and experiences of stakeholders and experts in six European countries. Overcoming the cultural, political and structural barriers to evaluation should be driven by payers and providers, for example by building in incentives such as feedback on performance, aligning financial incentives with programme objectives, collectively participating in designing an appropriate framework for evaluation, and making data use and accessibility consistent with data protection policies
Methoden zur Auswertung hyperspektraler Fernerkundungsdaten für die Untersuchung von Zustandsveränderungen perennierender Pflanzen im Rahmen des Monitorings bergbaubedingter Umwelteinwirkungen
Absolute Calibration of the RapidEye Constellation - Progress and Plans
BlackBridge is a leading provider of quality high-resolution satellite imagery. With the RapidEye constellation of five earth observation satellites, BlackBridge images up to five million square kilometers of earth every day, and adds over one billion square kilometers of imagery to its archive every year. The satellites are equally phased in a sun-synchronous orbit which allows for the possibility of imaging any point on the Earth (between 75°S to 75°N) each day. As RapidEye data features a combination of wide area repetitive coverage and five meter pixel multi-spectral imagery covering visible and near infrared wavelengths, it is a natural choice for many industries and government agencies.
BlackBridge is always looking for ways to improve the usability and reliability of RapidEye data for its customers. For several years, the calibration and validation team at BlackBridge have partnered with the University of Arizona and South Dakota State University to ensure the RapidEye constellation was accurately absolutely calibrated. BlackBridge is continuing this relationship and is also looking into adding additional known calibration sites including the Marine Optical Buoy (MOBY). Also from the beginning, the RapidEye constellation was designed to complement and enhance existing and future freely available land imaging missions such as Landsat and Sentinel. To this end, BlackBridge has undertaken a cross-calibration campaign between the RapidEye constellation and Landsat 8 and will also have the ground work set to perform a cross-calibration with Sentinel 2 after its launch. These cross-calibrations will focus on target areas of interest to forestry and agriculture customers. BlackBridge thus hopes to benefit the user community by allowing it to more easily and confidently use RapidEye data combined with other datasets for their analyses. This presentation will summarize the most up to date results achieved from all the above efforts
DIN 18714-8 − Requirements to Image Quality
Photogrammetry and remote sensing provide procedures for deriving geometric and thematic information from image data. A variety of aircraft and space-based sensors are available to capture image data. According to the applications of German remote sensing and photogrammetry users DIN 18740 (DIN = German ISO regulations) defines this standard and specifies the quality requirements on optical remote sensing data.
Due to the possibilities of absolute geometric and radiometric calibration digital sensors provide new promising opportunities to create value added products like Digital Elevation Models, land-use maps etc. Such cameras combine the high geometric quality with the radiometric standards of earth observation systems.
The determination of the quality of remote sensing data can in principle be distinguished by (spectral) radiometric and geometric aspects. The standard contains different metrics for accuracy issues (spectral, radiometric and geometric accuracy ) and for performance parameters like SNR, MTF . Image artifacts are another topic of the described standard. The paper gives an overview of the current debate and the possibility of standardization
Bildqualität von optischen Fernerkundungsdaten
Photogrammetrie und Fernerkundung bieten eine ganze Reihe unterschiedlicher
Verfahren zur Ableitung geometrischer, radiometrischer und thematischer Informationen
aus Bilddaten. Zur Erfassung der dafür benötigten Bilddaten stehen eine Vielzahl
von Flugzeug- und Weltraumsensoren zur Verfügung.
Digitale Sensoren bieten auf Grund der Möglichkeiten der absoluten geometrischen und radiometrischen
Kalibrierung vielversprechende Möglichkeiten zur Schaffung von Mehrwertprodukten
wie digitale Höhenmodelle, Landnutzungskarten etc. Solche Kameras kombinieren
die hohe geometrische Qualität mit den radiometrischen Standards von Erdbeobachtungssystemen.
Für die Qualitätsbewertung optischer Fernerkundungsdaten sind verschiedene Standards
und Spezifikationen verfügbar. Bei der Bestimmung der Bildqualität kann dabei zwischen
(spektralen) radiometrischen und geometrischen Aspekten unterschieden werden. Normen
enthalten verschiedene Messgrößen für Genauigkeitsprobleme (spektrale, radiometrische
und geometrische Genauigkeit) sowie für Leistungsparameter wie SNR, MTF. Bildartefakte
sind ein weiteres wichtiges Thema.
Der Beitrag führt in die Thematik ein und stellt einen neuen Ansatz zur effizienten radiometrischen
Validierung und Kalibrierung operationeller satellitengetragener Fernerkundungssensoren
vor
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