Air Traffic Control Operating Modes and the Management of Complexity

This report describes research exploring the relationship between structure and cognitive complexity in Air Traffic Control (ATC). Current work on structure and cognitive processes in ATC is reviewed leading to an ATC process model. Based on observations of the performance of the ATC system it appears that air traffic controllers have the ability to manipulate structure and structure-based abstractions in order to regulate the complexity of an ATC situation. The management of complexity has been integrated into the Controller Process Model through a Complexity Manager. It is hypothesized that the Complexity Manager operates by commanding switches between operating modes. In order to explore whether these operating modes can be observed in a simple ATC task, an experiment was designed. Participants were given scenarios with varying traffic levels. Their commands and their performance have been collected and analyzed. The experimental results show participants appeared to use each of the hypothesized operating modes. The use of the structure in each mode was also as expected

Challenges and special aspects of pulmonary hypertension in middle- to low-income regions: JACC state-of-the-art review

Challenges and special aspects related to the management and prognosis of pulmonary hypertension (PH) in middle- to low-income regions (MLIRs) range from late presentation to comorbidities, lack of resources and expertise, cost, and rare options of lung transplantation. Expert consensus recommendations addressing the specific challenges for prevention and therapy of PH in MLIRs with limited resources have been lacking. To date, 6 MLIR-PH registries containing mostly adult patients with PH exist. Importantly, the global prevalence of PH is much higher in MLIRs compared with high-income regions: group 2 PH (left heart disease), pulmonary arterial hypertension associated with unrepaired congenital heart disease, human immunodeficiency virus, or schistosomiasis are highly prevalent. This consensus statement provides selective, tailored modifications to the current PH guidelines to address the specific challenges faced in MLIRs, resulting in the first pragmatic and cost-effective consensus recommendations for PH care providers, patients, and their families

Human Norovirus Interactions with Histo-Blood Group Antigens and Human Milk Oligosaccharides

Human noroviruses interact with both human histo-blood group antigens (HBGAs) and human milk oligosaccharides (HMOs). The former are believed to be important for a virus infection, while the latter might act as natural decoys in the host during an infection. However, certain noroviruses are known to bind poorly to HBGAs and yet still cause infections; some interact with numerous HBGA types but are nonprevalent; and yet others bind HBGAs and seem to be increasing in prevalence. HBGAs and HMOs can be found as soluble antigens in humans, can be structurally alike, and can interact with equivalent residues at identical binding pockets on the capsid. In this Gem, we discuss HBGA and HMO binding studies for human noroviruses, concentrating on the clinically important genogroup II noroviruses. In short, the roles of HBGA and HMO interactions in norovirus infections are still unclear

Human Milk Oligosaccharides as Promising Antivirals

Human milk oligosaccharides (HMOs) are diverse unconjugated carbohydrates that are highly abundant in human breast milk. These glycans are investigated in the context of exhibiting multiple functions in infant growth and development. They seem to provide protection against infectious diseases, including a number of poorly manageable viral infections. Although the potential mechanism of the HMO antiviral protection is rather broad, much of the current experimental work has focused on studying of HMO antiadhesive properties. HMOs may mimic structures of viral receptors and block adherence to target cells, thus preventing infection. Still, the potential of HMOs as a source for new antiviral drugs is relatively unexploited. This can be partly attributed to the extreme complexity of the virus-carbohydrate interactions and technical difficulties in HMO isolation, characterization, and manufacturing procedures. Fortunately, we are currently entering a period of major technological advances that have enabled deeper insights into carbohydrate mediated viral entry, rational selection of HMOs as anti-entry inhibitors, and even evaluation of individual synthetic HMO structures. Here, we provide an up-to-date review on glycan binding studies for rotaviruses, noroviruses, influenza viruses, and human immunodeficiency viruses. We also discuss the preventive and therapeutic potential of HMOs as anti-entry inhibitors and address challenges on the route from fundamental studies to clinical trials

Avidity of alpha-fucose on human milk oligosaccharides and blood group-unrelated oligo/polyfucoses is essential for potent norovirus-binding targets

There is agreement with respect to norovirus infection routes in humans regarding binding of the pathogen to gastrointestinal epithelia via recognition of blood group-active mucin-typeO-glycans as the initiating and essential event. Among food additives playing a potential role in applications to protect newborns, human milk oligosaccharides (HMOs) as competitors are of major importance. By focusing on fractions of high-molecular mass HMOs with high fucose contents, we attempted to identify the structural elements required for norovirus GII.4 (Sydney 2012, JX459908) capsid binding in neoglycolipid-based arrays. We provide evidence that HMO fractions with the strongest binding capacities contained hepta- to decasaccharides expressing branches with terminal blood group H1 or Lewis-b antigen. H2 antigen, as recognized by UEA-I lectin, is apparently not expressed in high-mass HMOs. Beyond affinity, sterical and valency effects contribute more to virus-like particle binding, as revealed for oligovalent fucose conjugates of alpha-cyclodextrin and oligofucoses from fucoidan. Accordingly, high-mass HMOs with oligovalent fucose can exhibit stronger binding capacities compared with monovalent fucose HMOs. The above features were revealed for the most clinically relevant and prevalent GII.4 strain and are distinct from other strains, like GII.10 (Vietnam 026, AF504671), which showed a preference for blood group Lewis-a positive glycans