Modeling and Experimental Investigation of Resonant Viscosity and Mass Density Sensors Considering their Cross-Sensitivity to Temperature

AbstractIn this contribution we discuss a generalized, reduced order model for resonant viscosity and mass density sensors which considers also the devices’ cross sensitivities to temperature. The applicability of the model is substantiated by experimental results from measurements obtained with a circular steel tuning fork in various liquids and temperatures. Advantages of this model are its simplicity, its general applicability for resonant mass density and viscosity sensors which furthermore facilitates the comparison of different sensors

Numerical Optimization of an Open-Ended Coaxial Slot Applicator for the Detection and Microwave Ablation of Tumors

A multiobjective optimization method for a dual-mode microwave applicator is proposed. Dual-modality means that microwaves are used apart from the treatment, and also for the monitoring of the microwave ablation intervention. (1) The use of computational models to develop and improve microwave ablation applicator geometries is essential for further advances in this field. (2) Numerical electromagnetic–thermal coupled simulation models are used to analyze the performance of the dual-mode applicator in liver tissue; the sensitivity evaluation of the dual-mode applicator’s sensing mode constrains the set of optimal solutions. (3) Three Pareto-optimal design parameter sets are derived that are optimal in terms of applicator efficiency as well as volume and sphericity of the ablation zone. The resulting designs of the dual-mode applicator provide a suitable sensitivity to distinguish between healthy and tumorous liver tissue. (4) The optimized designs are presented and numerically characterized. An improvement on the performance of previously proposed dual-mode applicator designs is achieved. The multiphysical simulation model of electromagnetic and thermal properties of the applicator is applicable for future comprehensive design procedures

Gradient-Index-Based Frequency-Coded Retroreflective Lenses for mm-Wave Indoor Localization

This article introduces retroreflective lenses for millimeter-wave radio-frequency indoor localization. A three-dimensional (3D) gradient-index Luneburg lens is employed to increase radar cross section (RCS) of photonic-crystal high-Q resonators and its performance is compared to conventional radar retroreflectors. A classic Luneburg lens with and without a reflective layer is realized with 25 mm diameter (6.7 lambda(0)), showing a realized gain of 24.6 dBi and a maximum RCS of -9.22 dBm(2) at 80 GHz. The proposed Luneburg lens with embedded high-Q resonators as frequency-coded particles in a photonic crystal structure, operating as a reflective layer, achieved a maximum RCS of -15.84 dBm(2) at the resonant frequency of 76.5 GHz and showed a repeatable response each 18 degrees over +/- 36 degrees in two perpendicular planes. With this high RCS of the Luneburg lens, a maximum readout range of 1.3 m could be achieved compared to 0.15 m without the lens at 76.5 GHz for the same transmit power, receiver sensitivity, and gain of the reader antenna

Wide-Angle Ceramic Retroreflective Luneburg Lens Based on Quasi-Conformal Transformation Optics for Mm-Wave Indoor Localization

This paper presents a quasi-conformal transformation optics (QCTO) based three-dimensional (3D) retroreflective attened Luneburg lens for wide-angle millimeter-wave radio-frequency indoor localization. The maximum detection angle and radar cross-section (RCS) are investigated, including an impedance matching layer (IML) between the lens antenna and the free-space environment. The 3D QCTO Luneburg lenses are fabricated in alumina by lithography-based ceramic manufacturing, a 3D printing process. The manufactured structures have a diameter of 29.9 mm (4 lambda_0), showing a maximum realized gain of 16.51 dBi and beam steering angle of +-70° at 40 GHz. The proposed QCTO Luneburg lens with a metallic reflective layer achieves a maximum RCS of -20.05 dBsqm at 40 GHz with a wide-angle response over +-37°, while the structure with an IML between the lens and air improves these values to a maximum RCS of -15.78 dBsqm and operating angular response between +-50°

Transcriptional profiling of mature Arabidopsis trichomes reveals that NOECK encodes the MIXTA-like transcriptional regulator MYB106

Leaf hairs (trichomes) of Arabidopsis (Arabidopsis thaliana) have been extensively used as a model to address general questions in cell and developmental biology. Here, we lay the foundation for a systems-level understanding of the biology of this model cell type by performing genome-wide gene expression analyses. We have identified 3,231 genes that are up-regulated in mature trichomes relative to leaves without trichomes, and we compared wild-type trichomes with two mutants, glabra3 and triptychon, that affect trichome morphology and physiology in contrasting ways. We found that cell wall-related transcripts were particularly overrepresented in trichomes, consistent with their highly elaborated structure. In addition, trichome expression maps revealed high activities of anthocyanin, flavonoid, and glucosinolate pathways, indicative of the roles of trichomes in the biosynthesis of secondary compounds and defense. Interspecies comparisons revealed that Arabidopsis trichomes share many expressed genes with cotton (Gossypium hirsutum) fibers, making them an attractive model to study industrially important fibers. In addition to identifying physiological processes involved in the development of a specific cell type, we also demonstrated the utility of transcript profiling for identifying and analyzing regulatory gene function. One of the genes that are differentially expressed in fibers is the MYB transcription factor GhMYB25. A combination of transcript profiling and map-based cloning revealed that the NOECK gene of Arabidopsis encodes AtMYB106, a MIXTA-like transcription factor and homolog of cotton GhMYB25. However, in contrast to Antirrhinum, in which MIXTA promotes epidermal cell outgrowth, AtMYB106 appears to function as a repressor of cell outgrowth in Arabidopsis

Endoreplication Controls Cell Fate Maintenance

Cell-fate specification is typically thought to precede and determine cell-cycle regulation during differentiation. Here we show that endoreplication, also known as endoreduplication, a specialized cell-cycle variant often associated with cell differentiation but also frequently occurring in malignant cells, plays a role in maintaining cell fate. For our study we have used Arabidopsis trichomes as a model system and have manipulated endoreplication levels via mutants of cell-cycle regulators and overexpression of cell-cycle inhibitors under a trichome-specific promoter. Strikingly, a reduction of endoreplication resulted in reduced trichome numbers and caused trichomes to lose their identity. Live observations of young Arabidopsis leaves revealed that dedifferentiating trichomes re-entered mitosis and were re-integrated into the epidermal pavement-cell layer, acquiring the typical characteristics of the surrounding epidermal cells. Conversely, when we promoted endoreplication in glabrous patterning mutants, trichome fate could be restored, demonstrating that endoreplication is an important determinant of cell identity. Our data lead to a new model of cell-fate control and tissue integrity during development by revealing a cell-fate quality control system at the tissue level

Endogenous overexpression of Populus MYB186 increases trichome density, improves insect pest resistance, and impacts plant growth

Trichomes are specialized epidermal cells that generally play a role in reducing transpiration and act as a deterrent to herbivory. In a screen of activation-tagged Populus tremula  ×  Populus alba 717-1B4 trees, we identified a mutant line, fuzzy , with increased foliar trichome density. This mutant also had a 35% increase in growth rate and a 200% increase in the rate of photosynthesis as compared with wild-type poplar. The fuzzy mutant had significant resistance to feeding by larvae of the white-spotted tussock moth ( Orgyia leucostigma ), a generalist insect pest of poplar trees. The fuzzy trichome phenotype is attributable to activation tagging and increased expression of the gene encoding PtaMYB186 , which is related to Arabidopsis thaliana MYB106 , a known regulator of trichome initiation. The fuzzy phenotype can be recapitulated by overexpressing PtaMYB186 in poplar. PtaMYB186 overexpression results in reconfiguration of the poplar transcriptome, with changes in the transcript abundance of suites of genes that are related to trichome differentiation. It is notable that a plant with misexpression of a gene responsible for trichome development also had altered traits related to growth rate and pest resistance, suggesting that non-intuitive facets of plant development might be useful targets for plant improvement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79232/1/TPJ_4343_sm_FigsS1-S3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/79232/2/j.1365-313X.2010.04343.x.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/79232/3/TPJ_4343_sm_TableS5.pd