Effects of the COVID-19 pandemic on disclosures in passenger airlines’ financial statements

This article analyses the impact of COVID-19 on the disclosures of 24 financial statements of passenger airline companies in Europe (including United Kingdom), North America, China (including Hong Kong), Middle East and South America for financial year 2020. This impact is significant in our research sample as evidenced by a total revenue decrease of 60% compared to previous year. We have examined for specific areas whether the airline companies contribute to transparent reporting and useful information to existing and potential investors, regulators, supportive government bodies and other stakeholders following the COVID-19 pandemic. The areas of our research focus on going concern, rent concessions, significant judgements and estimates, impairments, governmental support and the auditor's report. Our study shows diversity in the extent of transparency in both financial statements and auditor's opinions. Good financial practices are included and discussed in this study to further stimulate transparency in corporate reporting

Automated airborne pest monitoring of drosophila suzukii in crops and natural habitats

Drosophila suzukii has become a serious pest in Europe attacking many soft-skinned crops such as several berry species and grapevines since its spread in 2008 to Spain and Italy. An efficient and accurate monitoring system to identify the presence of Drosophila suzukii in crops and their surroundings is essential for the prevention of damage to economically valuable fruit crops. Existing methods for monitoring Drosophila suzukii are costly, time and labor intensive, prone to errors, and typically conducted at a low spatial resolution. To overcome current monitoring limitations, we are developing a novel system consisting of sticky traps which are monitored by means of Unmanned Aerial Vehicles (UAVs) and an image processing pipeline that automatically identifies and counts the number of Drosophila suzukii per trap location. To this end, we are currently collecting high resolution RGB imagery of Drosophila suzukii flies in sticky traps taken from both a static position (tripod) and from a UAV, which are then used as input to train deep learning models. Preliminary results show that a large part of the of Drosophila suzukii flies that are caught in the sticky traps can be correctly identified by the trained deep learning models. In the future, an autonomously flying UAV platform will be programmed to capture imagery of the sticky traps under field conditions. The collected imagery will be transferred directly to cloud-based storage for subsequent processing and analysis to identify the presence and count of Drosophila suzukii in near real time. This data will be used as input to a decision support system (DSS) to provide valuable information for farmers

A new setup to measure bidirectional reflectance distribution functions

The Plant Facility, a new laboratory goniometer system, built by the Wageningen University has been tested in order to take bidirectional reflectance distribution function (BRDF) measurements. An ASD FieldSpec 3 spectroradiometer mounted on an industrial robot arm is able to measure small targets over the full hemispherical dome. Due to the fast acquisition time it is a promising setup for BRDF measurements of natural targets. In this paper, the preliminary results of BRDF measurements of freshly grown watercress and lawn grass are presented. The results show that both watercress and lawn grass show anisotropic behavior and that LAI plays an important role

The use of positively charged or low surface free energy coatings versus polymer brushes in controlling biofilm formation

Biofilm formation on biomaterials implant surfaces and subsequent infectious complications are a frequent reason for failure of many biomedical devices, such as total hip arthroplasties, vascular catheters and urinary catheters. The development of a biofilm is initiated by the formation of a conditioning film of adsorbed macromolecules, such as proteins, followed by adhesion of microorganisms, where after they grow and anchor through secretion of extracellular polymeric substances. Adhesion of microorganisms is influenced by the physico-chemical properties of the biomaterial surface. Positively charged materials stimulate bacterial adhesion, but prevent growth of adhering bacteria. The use of low surface free energy materials did not always reduce in vitro adhesion of bacteria, but has been found beneficial in in vivo applications where fluctuating shear forces prevail, like on intra-oral devices and urine catheters. Polymer brushes have shown a very high reduction in in vitro adhesion of a great variety of microorganisms. However, for clinical application, the long term stability of polymer brushes is still a limiting factor. Further effort is therefore required to enhance the stability of polymer brushes on biomaterial implant surfaces to facilitate clinical use of these promising coating

Inhibition of adhesion of yeasts and bacteria by poly(ethylene oxide-)brushes on glass in a parallel plate flow chamber

Poly(ethylene oxide) (PEO)-brushes are generally recognized as protein-repellent surfaces, and although a role in discouraging microbial adhesion has been established for some strains and species, no study exists on the effects of PEO-brushes on a large variety of bacterial and yeast strains. In this paper, a PEO-brush has been covalently attached to glass and silica by reaction in a polymer melt. Subsequently, the presence of a PEO-brush was demonstrated using contact angle measurements, X-ray photoelectron spectroscopy and ellipsometry. For five bacterial (Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus salivarius, Escherichia coli and Pseudomonas aeruginosa) and two yeast strains (Candida albicans and Candida tropicalis), adhesion to PEO-brushes was compared with adhesion to bare glass in a parallel plate flow chamber. The initial deposition rates of Sta. epidermidis, Sta. aureus and Str. salivarius to glass were relatively high, between 2400 and 2600 cm-2 s-1, while E. coli and P. aeruginosa deposited much more slowly. The initial deposition rates of the yeasts to glass were 144 and 444 cm-2 s-1 for C. albicans GB 1/2 and C. tropicalis GB 9/9, respectively. Coating of the glass surface with a PEO-brush yielded more than 98 % reduction in bacterial adhesion, although for the more hydrophobic P. aeruginosa a smaller reduction was observed. For both yeast species adhesion suppression was less effective than for the bacteria and here too the more hydrophobic C. tropicalis showed less reduction than the more hydrophilic C. albicans. The PEO-brush had a thickness of 22 nm in water, as inferred from ellipsometry. Assuming that on bare glass the adhered micro-organisms are positioned only a few nanometers away from the surface and that the brush keeps them at a distance of 22 nm, it is calculated that the brush yields a sevenfold attenuation of the Lifshitz–Van der Waals attraction to the surface between the micro-organisms and the surface. Decreased Lifshitz–van der Waals attraction may be responsible for the suppression of the microbial adhesion observed