324 research outputs found

    An S-FSCW Based Multi-Channel Reader System for Beamforming Applications using Surface Acoustic Wave Sensors

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    Interrogating multiple surface acoustic wave (SAW) sensors located within the same radar beam require techniques to separate the multiple superposing SAW sensor responses. The presented multi-channel reader features four parallel transceiver channels, which are based on the switched frequency-stepped continuous-wave principle and high-speed parallelized baseband electronics. Thus classical beamforming applications including angle of arrival measurement of single SAW tags and the angular separation of multiple SAW sensors are presented and compared to a multiple-input multiple-output (MIMO) approach. Due to the larger virtual array in the MIMO approach a larger aperture can be synthesized, which leads to significantly better angular separation results. The level analysis for the given system is verified by baseband-power measurements at different readout distances, considering the hardware parameters as well as the free-space propagation aspects. Finally measurements assess the maximum interrogation distance for the system

    Building an integrated modeling framework for assessing land-use change and its consequences for areal water balance in mountainous Southwest China

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    The opening up of China's industry towards market orientation has a distinct impact on natural resources as well as on social structures. The example of rubber introduction in Yunnan province (SW China) shows the mutual interdependencies between economy, natural resources, and social structures. We assess the impacts of rubber introduction and possible development paths in the study area. An integrated modeling framework (NabanFrame) is developed for the catchment of the Naban River (size 270 km2), a tributary to the Mekong River. NabanFrame comprises an agro-economic, ecological, and social model. Altogether they interact with a land-use change model via defined interfaces. Effects on the water cycle are considered by additionally integrating the spatially distributed rainfall-runoff and water balance model AKWA-MÂź in the model framework. Therefore, a reasonable parameterization is needed to assess the land-use changes on areal water fluxes. The authors conclude that the chosen hydrological model is able to assess the impacts of land conversion (from forest to rubber plantations) on catchment hydrology and address further adaptations to be implemented in the hydrological model.BMBF/LILA

    Natural fermion mass hierarchy and mixings in family unification

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    We present an SU(9) model of family unification with three light chiral families, and a natural hierarchy of charged fermion masses and mixings. The existence of singlet right handed neutrions with masses about two orders of magnitude smaller than the GUT scale, as needed to understand the light neutrinos masses via the see-saw mechanism, is compelling in our model.Comment: 7 pages, no figur

    Towards Sustainable Research Data Management in Human-Computer Interaction

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    We discuss important aspects of HCI research regarding Research Data Management (RDM) to achieve better publication processes and higher reuse of HCI research results. Various context elements of RDM for HCI are discussed, including examples of existing and emerging infrastructures for RDM. We briefly discuss existing approaches and come up with additional aspects which need to be addressed. This is to apply the so-called FAIR principle fully, which -- besides being findable and accessible -- also includes interoperability and reusability. We also discuss briefly the kind of research data types that play a role here and propose to build on existing work and involve the HCI scientific community to improve current practices

    A Clinical Trial

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    Purpose The aim of this study was the systematic image quality evaluation of coronary CT angiography (CTA), reconstructed with the 3 different levels of adaptive iterative dose reduction (AIDR 3D) and compared to filtered back projection (FBP) with quantum denoising software (QDS). Methods Standard-dose CTA raw data of 30 patients with mean radiation dose of 3.2 ± 2.6 mSv were reconstructed using AIDR 3D mild, standard, strong and compared to FBP/QDS. Objective image quality comparison (signal, noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), contour sharpness) was performed using 21 measurement points per patient, including measurements in each coronary artery from proximal to distal. Results Objective image quality parameters improved with increasing levels of AIDR 3D. Noise was lowest in AIDR 3D strong (p≀0.001 at 20/21 measurement points; compared with FBP/QDS). Signal and contour sharpness analysis showed no significant difference between the reconstruction algorithms for most measurement points. Best coronary SNR and CNR were achieved with AIDR 3D strong. No loss of SNR or CNR in distal segments was seen with AIDR 3D as compared to FBP. Conclusions On standard- dose coronary CTA images, AIDR 3D strong showed higher objective image quality than FBP/QDS without reducing contour sharpness

    Bodenchemische Charakteristka entlang prĂ€ferentieller Fließwege in Waldböden mit unterschiedlicher P-VerfĂŒgbarkeit

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    In der vorliegenden Studie wurden die prĂ€ferentiellen Fließwege in verschiedenen Waldböden charakterisiert und bodenchemische Parameter im Bereich der Fließwege sowie der nicht-durchflossenen Bodenmatrix analysiert. Die untersuchten Waldstandorte unterscheiden sich signifikant hinsichtlich der VerfĂŒgbarkeit mineralischer Phosphor-Quellen (P-reich zu P-arm), was sehr wahrscheinlich die ErnĂ€hrungsstrategie der Buchenbestockung an diesen Standorten wesentlich beeinflusst. Zur Charakterisierung der prĂ€ferentiellen Fließwege in den Böden wurde diese mittels Farbtracer-Experimenten, digitaler Bildanalyse und statistischer Auswertung der Verteilungsmuster untersucht. Die bodenchemische Charakterisierung der Fließwege erfolgte anhand Analyse der chemischen Bindungsformen von P, Al, Fe und Mn, der C- und N-Gesamtgehalte sowie daraus berechneter VerhĂ€ltnisse (z.B. C:P). Die Ergebnisse zeigen, dass sich sowohl die Fließweg-Verteilung in den Böden als auch die Verteilung der bodenchemischen Parameter an den einzelnen Standorten deutlich unterscheiden. Trotz sehr unterschiedlicher P-Gehalte im Boden wiesen die Gehalte an labilem, leicht pflanzenverfĂŒgbarem P in den organischen Auflagen aller Standorte Ă€hnliche GrĂ¶ĂŸenordnungen auf. WĂ€hrend der P-arme Standort jedoch sehr stark sinkende labile P-Gehalte mit der Tiefe zeigte, war der Tiefengradient dieser Fraktion am P-reichen Standort deutlich schwĂ€cher ausgeprĂ€gt. Die VerhĂ€ltnisse von C zu organisch gebundenem P (C:Po) waren am P-reichen Standort gering und nahmen ĂŒber die intermediĂ€ren bis hin zum schlecht P-versorgten Standort deutlich zu. Am P-armen Standort deuten die sehr hohen C:Po-Werte, insbesondere in der organischen Auflage, auf intensive P-Recyclingprozesse hin. Des Weiteren wurden Hinweise auf eine Anreicherung organisch gebundender P-Formen in prĂ€ferentiellen Fließwegen im Vergleich zur Bodenmatrix gefunden, die mit einem erhöhten C:Po in den Fließwegen einhergehen

    Follistatin protein enhances satellite cell counts in reinnervated muscle

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    Background Muscle recovery following peripheral nerve repair is sup-optimal. Follistatin (FST), a potent muscle stimulant, enhances muscle size and satellite cell counts following reinnervation when administered as recombinant FST DNA via viral vectors. Local administration of recombinant FST protein, if effective, would be more clinically translatable but has yet to be investigated following muscle reinnervation. Objective  The aim of this study is to assess the effect of direct delivery of recombinant FST protein on muscle recovery following muscle reinnervation. Materials and Methods  In total, 72 Sprague-Dawley rats underwent temporary (3 or 6 months) denervation or sham denervation. After reinnervation, rats received FST protein (isoform FS-288) or sham treatment via a subcutaneous osmotic pump delivery system. Outcome measures included muscle force, muscle histomorphology, and FST protein quantification. Results  Follistatin treatment resulted in smaller muscles after 3 months denervation ( p  = 0.019) and reduced force after 3 months sham denervation ( p  < 0.001). Conversely, after 6 months of denervation, FST treatment trended toward increased force output ( p  = 0.066). Follistatin increased satellite cell counts after denervation ( p  < 0.001) but reduced satellite cell counts after sham denervation ( p  = 0.037). Conclusion  Follistatin had mixed effects on muscle weight and force. Direct FST protein delivery enhanced satellite cell counts following reinnervation. The positive effect on the satellite cell population is intriguing and warrants further investigation

    PKB/SGK-resistant GSK-3 signaling following unilateral ureteral obstruction

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    Background/Aims: Renal tissue fibrosis contributes to the development of end-stage renal disease. Causes for renal tissue fibrosis include obstructive nephropathy. The development of renal fibrosis following unilateral ureteral obstruction (UUO) is blunted in gene-targeted mice lacking functional serum- and glucocorticoid-inducible kinase SGK1. Similar to Akt isoforms, SGK1 phosphorylates and thus inactivates glycogen synthase kinase GSK-3. The present study explored whether PKB/SGK-dependent phoshorylation of GSK-3α/ÎČ impacts on pro-fibrotic signaling following UUO. Methods: UUO was induced in mice carrying a PKB/SGK-resistant GSK-3α/ÎČ (gsk-3KI) and corresponding wild-type mice (gsk-3WT). Three days after the obstructive injury, expression of fibrosis markers in kidney tissues was analyzed by quantitative RT-PCR and western blotting. Results: GSK-3α and GSK-3ÎČ phosphorylation was absent in both, the non-obstructed and the obstructed kidney tissues from gsk-3KI mice but was increased by UUO in kidney tissues from gsk-3WT mice. Expression of α-smooth muscle actin, type I collagen and type III collagen in the non-obstructed kidney tissues was not significantly different between gsk-3KI mice and gsk-3WT mice but was significantly less increased in the obstructed kidney tissues from gsk-3KI mice than from gsk-3WT mice. After UUO treatment, renal ÎČ-catenin protein abundance and renal expression of the ÎČ-catenin sensitive genes: c-Myc, Dkk1, Twist and Lef1 were again significantly less increased in kidney tissues from gsk-3KI mice than from gsk-3WT mice. Conclusions: PKB/SGK-dependent phosphorylation of glycogen synthase kinase GSK-3 contributes to the pro-fibrotic signaling leading to renal tissue fibrosis in obstructive nephropathy

    Paths Explored, Paths Omitted, Paths Obscured: Decision Points & Selective Reporting in End-to-End Data Analysis

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    Drawing reliable inferences from data involves many, sometimes arbitrary, decisions across phases of data collection, wrangling, and modeling. As different choices can lead to diverging conclusions, understanding how researchers make analytic decisions is important for supporting robust and replicable analysis. In this study, we pore over nine published research studies and conduct semi-structured interviews with their authors. We observe that researchers often base their decisions on methodological or theoretical concerns, but subject to constraints arising from the data, expertise, or perceived interpretability. We confirm that researchers may experiment with choices in search of desirable results, but also identify other reasons why researchers explore alternatives yet omit findings. In concert with our interviews, we also contribute visualizations for communicating decision processes throughout an analysis. Based on our results, we identify design opportunities for strengthening end-to-end analysis, for instance via tracking and meta-analysis of multiple decision paths
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