The averaged periodogram estimator for a power law in coherency

We prove the consistency of the averaged periodogram estimator (APE) in two new cases. First, we prove that the APE is consistent for negative memory parameters, after suitable tapering. Second, we prove that the APE is consistent for a power law in the cross‐spectrum and therefore for a power law in the coherency, provided that sufficiently many frequencies are used in estimation. Simulation evidence suggests that the lower bound on the number of frequencies is a necessary condition for consistency. For a Taylor series approximation to the estimator of the power law in the cross‐spectrum, we consider the rate of convergence and obtain a central limit theorem under suitable regularity conditions.     

Consumer Sensory Analysis of High Flavonoid Transgenic Tomatoes

Tomatoes have ameliorative effects on cardiovascular disease and cancer. In this study, metabolic engineering of flavonoids was utilized to improve the nutritional value of tomatoes by increasing flavonol and anthocyanin content. Total flavonol content was significantly increased in both the peel and flesh using the onion chalcone isomerase (CHI) gene. The Delila (Del) and Rosea1 (Ros1) genes from the snapdragon Antirrhinum majus were concomitantly expressed to produce an anthocyanin‐rich tomato which was purple in color. Sensory evaluation by a panel of 81 untrained consumers revealed no significant difference in liking of color or texture between CHI, Del/Ros1, and wild‐type tomatoes. Consumers reported marginal but significantly higher preference for the flavor and overall liking of CHI tomatoes over Del/Ros1 and wild‐type tomatoes. This study is the first to report the results of sensory tests of transgenic tomatoes by a consumer panel representing the general consuming public.     

Spray drying of a phenolic‐rich membrane filtration fraction of olive mill wastewater: optimisation and dried product quality

Olive mill wastewater (OMWW) from 3‐ and 2‐phase mills was subjected to a two‐step membrane filtration process. The obtained reverse osmosis retentate (RO‐R) is a phenolic‐rich coproduct stream, and the reverse osmosis permeate is a near‐pure water stream. A pilot‐scale spray dryer was used for the production of RO‐R powder. The optimum temperature/feed pump conditions were obtained for 3‐phase (150°C/4.4 Hz) and for 2‐phase RO‐R (175°C/3.8 Hz). The powders obtained by spray drying under these conditions were analysed for physicochemical properties, including identification and quantification of phenolic compounds. Protocatechuic acid, 3‐hydroxytyrosol, tyrosol, vanillic acid and p‐coumaric acid were quantified in both RO‐R powders, which show the possibility to obtain a phenolic‐rich powder from an OMWW filtration fraction. This will lead towards better usage of by‐products from olive oil production.     

Adhesion of a chemically deposited monetite coating to a Ti substrate

Monetite is a promising biomaterial for restoring the function of the compromised skeletal structures due to its superior osteoconductive and resorption properties. However, its potential as a coating for orthopaedic implants in load bearing applications has not yet been investigated. The aim of this study was to prepare monetite coating on Ti substrate in mild conditions, which may allow incorporation of protein-based drugs during the coating deposition. Coatings were prepared using chemical deposition of monetite on Ti substrate in acidic conditions at 75 °C for 24 h. Coatings were characterised by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Adhesion of the coatings to Ti substrate was measured using tensile tests. EDS confirmed the calcium phosphate nature of the coating and XRD and FTIR confirmed the monetite phase of the coatings. SEM revealed that the coatings were formed of densely packed plate-like monetite crystals, with the crystal size approximately 20 × 10 × 5 μm. Adhesion tests showed cohesive failure of the monetite coatings and the tensile strength of the coating was in the range of 15.43 ± 0.20 MPa. Mechanical tests showed that monetite coatings were stable and could be considered for use with Ti orthopaedic implants.     

Influence of dynamic stimulation,visual perception and individual susceptibility to car sickness during controlled stop-and-go driving

Forschung im Ingenieurwesen - The enjoyment and usage of highly automated vehicles might be reduced by motion sickness. This study addresses the influencing factors of dynamic stimulation, visual...     

The Innate Immune Glycoprotein Lactoferrin Represses the Helicobacter pylori cag Type IV Secretion System

Chronic infection with Helicobacter pylori increases risk of gastric diseases including gastric cancer. Despite development of a robust immune response, H. pylori persists in the gastric niche. Progression of gastric inflammation to serious disease outcomes is associated with infection with H. pylori strains which encode the cag Type IV Secretion System (cag T4SS). The cag T4SS is responsible for translocating the oncogenic protein CagA into host cells and inducing pro-inflammatory and carcinogenic signaling cascades. Our previous work demonstrated that nutrient iron modulates the activity of the T4SS and biogenesis of T4SS pili. In response to H. pylori infection, the host produces a variety of antimicrobial molecules, including the iron-binding glycoprotein, lactoferrin. Our work shows that apo-lactoferrin exerts antimicrobial activity against H. pylori under iron-limited conditions, while holo-lactoferrin enhances bacterial growth. Culturing H. pylori in the presence of holo-lactoferrin prior to co-culture with gastric epithelial cells, results in repression of the cag T4SS activity. Concomitantly, a decrease in biogenesis of cag T4SS pili at the host-pathogen interface was observed under these culture conditions by high-resolution electron microscopy analyses. Taken together, these results indicate that acquisition of alternate sources of nutrient iron plays a role in regulating the pro-inflammatory activity of a bacterial secretion system and present novel therapeutic targets for the treatment of H. pylori-related disease.     

The New ChemPren Process for the Conversion of Waste Plastic to Chemicals and Fuel

A new technology, ChemPren, is being developed for the catalytic conversion of mixed municipal waste plastic to valuable chemicals and fuel. ChemPren provides a sustainable, clean energy solution to society’s challenge of addressing the 100+ million tons of waste plastic generated annually worldwide. Currently only 7 % is recycled, with the remaining 93+ million being discarded to landfills or burned without useful energy generation.     

Mg2FeH6–LiBH4 and Mg2FeH6–LiNH2 composite materials for hydrogen storage

Two composite hydrogen storage materials based on Mg₂FeH₆ were investigated for the first time. The Mg₂FeH₆–LiBH₄ composite of molar ratio 1:5 showed a hydrogen desorption capacity of 5.6 wt.% at 370 °C, and could be rehydrogenated to 3.6 wt.% with the formation of MgH₂, as the material was heated to 445 °C and held at this temperature. The Mg₂FeH₆–LiNH₂ composite of 3:10 molar ratio exhibited a hydrogen desorption capacity of 4.3 wt.% and released hydrogen at 100 °C lower then the Mg₂FeH₆–LiBH₄ composite, but this mixture could not be rehydrogenated. Compared to neat Mg₂FeH₆, both composites show enhanced hydrogen storage properties in terms of desorption kinetics and capacity at these low temperatures. In particular, Mg₂FeH₆–LiNH₂ exhibits a much lower desorption temperature than neat Mg₂FeH₆, but only Mg₂FeH₆–LiBH₄ re-absorbs hydrogen.