Thermal response testing of a fractured hard rock aquifer with and without induced groundwater flow

This study quantifies experimentally the influence of groundwater on the thermal conductivity measurements via thermal response tests (TRT) in a fractured hard rock with low matrix permeability. An artificial groundwater flow towards a nearby well was induced by groundwater extraction and a TRT performed simultaneously. The results were compared with a TRT performed 24?days later in the same well without groundwater extraction. The effect of the groundwater flow is shown indirectly by the enhanced effective thermal conductivity and directly through the comparison of temperature profiles before and 4?h after both TRTs. Simulations in FEFLOW show that a groundwater flow velocity of 130–1,300?m?d^?1 through one open horizontal fracture of small volume increases the effective thermal conductivity by 11?% in the studied system.     

Molecular,Biochemical, and Organismal Analyses of Tomato Plants Simultaneously Attacked by Herbivores from Two Feeding Guilds

Previous work identified aphids and caterpillars as having distinct effects on plant responses to herbivory. We sought to decipher these interactions across different levels of biological organization, i.e., molecular, biochemical, and organismal, with tomato plants either damaged by one 3rd-instar beet armyworm caterpillar (Spodoptera exigua), damaged by 40 adult potato aphids (Macrosiphum euphorbiae), simultaneous damaged by both herbivores, or left undamaged (controls). After placing insects on plants, plants were transferred to a growth chamber for 5 d to induce a systemic response. Subsequently, individual leaflets from non-damaged parts of plants were excised and used for gene expression analysis (microarrays and quantitative real-time PCR), C/N analysis, total protein analysis, proteinase inhibitor (PI) analysis, and for performance assays. At the molecular level, caterpillars up-regulated 56 and down-regulated 29 genes systemically, while aphids up-regulated 93 and down-regulated 146 genes, compared to controls. Although aphids induced more genes than caterpillars, the magnitude of caterpillar-induced gene accumulation, particularly for those associated with plant defenses, was often greater. In dual-damaged plants, aphids suppressed 27% of the genes regulated by caterpillars, while caterpillars suppressed 66% of the genes regulated by aphids. At the biochemical level, caterpillars induced three-fold higher PI activity compared to controls, while aphids had no effects on PIs either alone or when paired with caterpillars. Aphid feeding alone reduced the foliar C/N ratio, but not when caterpillars also fed on the plants. Aphid and caterpillar feeding alone had no effect on the amount of protein in systemic leaves; however, both herbivores feeding on the plant reduced the amount of protein compared to aphid-damaged plants. At the organismal level, S. exigua neonate performance was negatively affected by prior caterpillar feeding, regardless of whether aphids were present or absent. This study highlights areas of concordance and disjunction between molecular, biochemical, and organismal measures of induced plant resistance when plants are attacked by multiple herbivores. In general, our data produced consistent results when considering each herbivore separately but not when considering them together.     

A TV Prior for High-Quality Scalable Multi-View Stereo Reconstruction

We present a scalable multi-view stereo method able to reconstruct accurate 3D models from hundreds of high-resolution input images. Local fusion of disparity maps obtained with semi-global matching enables the reconstruction of large scenes that do not fit into main memory. Since disparity maps may vary widely in quality and resolution, careful modeling of the 3D errors is crucial. We derive a sound stereo error model based on disparity uncertainty, which can vary spatially from tenths to several pixels. We introduce a feature based on total variation that allows pixel-wise classification of disparities into different error classes. For each class, we learn a disparity error distribution from ground-truth data using expectation maximization. We present a novel method for stochastic fusion of data with varying quality by adapting a multi-resolution volumetric fusion process that uses our error classes as a prior and models surface probabilities via an octree of voxels. Conflicts during surface extraction are resolved using visibility constraints and preference for voxels at higher resolutions. Experimental results on several challenging large-scale datasets demonstrate that our method yields improved performance both qualitatively and quantitatively.     

Development and Characterization of a 96-Well Exposure System for Safety Assessment of Nanomaterials

In this study, a 96-well exposure system for safety assessment of nanomaterials is developed and characterized using an air–liquid interface lung epithelial model. This system is designed for sequential nebulization. Distribution studies verify the reproducible distribution over all 96 wells, with lower insert-to-insert variability compared to non-sequential application. With a first set of chemicals (TritonX), drugs (Bortezomib), and nanomaterials (silver nanoparticles and (non-)fluorescent crystalline nanocellulose), sequential exposure studies are performed with human lung epithelial cells followed by quantification of the deposited mass and of cell viability. The developed exposure system offers for the first time the possibility of exposing an air–liquid interface model in a 96-well format, resulting in high-throughput rates, combined with the feature for sequential dosing. This exposure system allows the possibility of creating dose-response curves resulting in the generation of more reliable cell-based assay data for many types of applications, such as safety analysis. In addition to chemicals and drugs, nanomaterials with spherical shapes, but also morphologically more complex nanostructures can be exposed sequentially with high efficiency. This allows new perspectives on in vivo-like and animal-free approaches for chemical and pharmaceutical safety assessment, in line with the 3R principle of replacing and reducing animal experiments.     

Targeting of Deregulated Wnt/β-Catenin Signaling by PRI-724 and LGK974 Inhibitors in Germ Cell Tumor Cell Lines

The majority of patients with testicular germ cell tumors (GCTs) can be cured with cisplatin-based chemotherapy. However, for a subset of patients present with cisplatin-refractory disease, which confers a poor prognosis, the treatment options are limited. Novel therapies are therefore urgently needed to improve outcomes in this challenging patient population. It has previously been shown that Wnt/β-catenin signaling is active in GCTs suggesting that its inhibitors LGK974 and PRI-724 may show promise in the management of cisplatin-refractory GCTs. We herein investigated whether LGK-974 and PRI-724 provide a treatment effect in cisplatin-resistant GCT cell lines. Taking a genoproteomic approach and utilizing xenograft models we found the increased level of β-catenin in 2 of 4 cisplatin-resistant (CisR) cell lines (TCam-2 CisR and NCCIT CisR) and the decreased level of β-catenin and cyclin D1 in cisplatin-resistant NTERA-2 CisR cell line. While the effect of treatment with LGK974 was limited or none, the NTERA-2 CisR exhibited the increased sensitivity to PRI-724 in comparison with parental cell line. Furthermore, the pro-apoptotic effect of PRI-724 was documented in all cell lines. Our data strongly suggests that a Wnt/β-catenin signaling is altered in cisplatin-resistant GCT cell lines and the inhibition with PRI-724 is effective in NTERA-2 CisR cells. Further evaluation of Wnt/β-catenin pathway inhibition in GCTs is therefore warranted.     

Unsteady response of hydrogen and methane flames to pressure waves

Recent measurements of the direct response of premixed hydrocarbon flames to acoustic pressure fluctuations have shed doubt on the validity of analytical models that use irreversible one-step chemistry (Wangher et al., 2008) [1], and suggest that more realistic chemical kinetic models are needed to fully describe the unsteady dynamics of premixed flames. In this paper we present experimental results and numerical simulations for planar hydrogen flames which have simpler chemical kinetics than hydrocarbon flames. The simulations employ detailed chemical kinetics, including OH¹ chemiluminescence chemistry, so that the validity of using the emission from the excited OH¹ radical as a marker of the reaction rate can be assessed. By comparing our numerical results with measurements on hydrogen, and with previous measurements on methane, we show that OH¹ chemiluminescence does not always provide a reliable measure of heat release rate in the presence of a pressure driven interaction. Finally, our results are compared to the predictions of an analytical model for two-step chemistry with a chain-branching and a chain-breaking reaction (Clavin and Searby, 2008) [2]. We conclude that multi-step chemistry must be taken into account when evaluating the unsteady response of flames to pressure waves.     

A Novel PowderMEMS Technique for Fabrication of Low-Cost High-Power-Factor Thermoelectric Films and Micro-Patterns

Thermoelectric (TE) films, which are normally fabricated by MicroElectroMechanical-Systems (MEMS) technology, are crucial for the development of micro-TE devices (e.g., Peltier coolers for hot-spot cooling, TE generators). However, achieving a significant TE property (e.g., high power factor) of TE films and a low-cost fabrication process is challenging. A novel fabrication technique named PowderMEMS to fabricate high-performance, low-cost TE films, and micro-patterns is presented in this article. The TE film is based on agglomeration of micro-sized N-type ${\text{Bi}}_2{\text{Te}}_{2.5}{\text{Se}}_{0.5}$(BTS) powders with stoichiometric composition by the molten binder bismuth (Bi). The influence of the key process parameters (e.g., the weight ratio between the TE powder and the binder, the hot-pressing duration, and pressure) on the TE performance is investigated. The TE film exhibits a maximum power factor of 1.7 ${\text{mW m}}^{-1}{\mathrm{K}}^{-2}$ at room temperature, which is the highest value reported so far for the state-of-the-art TE thick film (thickness > 10 μm). Besides, the PowderMEMS-based TE films are successfully patterned to the micro-pillar array, which opens up a new MEMS-compatible approach for manufacturing micro-TE devices.