Novel measurement system for respiratory aerosols and droplets in indoor environments

The SARS-CoV-2 pandemic has created a great demand for a better understanding of the spread of viruses in indoor environments. A novel measurement system consisting of one portable aerosol-emitting mannequin (emitter) and a number of portable aerosol-absorbing mannequins (recipients) was developed that can measure the spread of aerosols and droplets that potentially contain infectious viruses. The emission of the virus from a human is simulated by using tracer particles solved in water. The recipients inhale the aerosols and droplets and quantify the level of solved tracer particles in their artificial lungs simultaneously over time. The mobile system can be arranged in a large variety of spreading scenarios in indoor environments and allows for quantification of the infection probability due to airborne virus spreading. This study shows the accuracy of the new measurement system and its ability to compare aerosol reduction measures such as regular ventilation or the use of a room air purifier.     

A Potent Mimetic of the Siglec-8 Ligand 6’-Sulfo-Sialyl Lewisx

Siglecs are members of the immunoglobulin gene family containing sialic acid binding N-terminal domains. Among them, Siglec-8 is expressed on various cell types of the immune system such as eosinophils, mast cells and weakly on basophils. Cross-linking of Siglec-8 with monoclonal antibodies triggers apoptosis in eosinophils and inhibits degranulation of mast cells, making Siglec-8 a promising target for the treatment of eosinophil- and mast cell-associated diseases such as asthma. The tetrasaccharide 6’-sulfo-sialyl Lewis^x has been identified as a specific Siglec-8 ligand in glycan array screening. Here, we describe an extended study enlightening the pharmacophores of 6’-sulfo-sialyl Lewis^x and the successful development of a high-affinity mimetic. Retaining the neuraminic acid core, the introduction of a carbocyclic mimetic of the Gal moiety and a sulfonamide substituent in the 9-position gave a 20-fold improved binding affinity. Finally, the residence time, which usually is the Achilles tendon of carbohydrate/lectin interactions, could be improved.     

Role of Perceived Importance in Intergroup Contact.

Furthering G. W. Allport's (1954) contentions for optimal contact, the authors introduce a new construct: the perceived importance of contact. They propose that perceived importance is the best proximal predictor of contact's reduction of prejudice. If individuals have opportunities for contact at work or in the neighborhood, their chances to have intergroup acquaintances and friends increase. Intergroup contact among acquaintances and friends can be perceived as more or less important, which in turn determines intergroup evaluations. A 1st study shows that the new measure of perceived importance is indeed distinct from established quantity and quality indicators. The results are cross-validated in a 2nd study that also sheds light on the meaning of importance. In 3rd and 4th studies, structural equation analyses and a meta-analysis support the hypotheses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Agility through discipline: a debate

While Beck asserts that agility is only possible through greater discipline on the part of everyone involved, Boehm counters that you don't broaden the definition of "discipline" by rejecting parts of it. Yet, from inside extreme programming, it seems that the only way to achieve the desired results is to view the world in 'both-and" terms instead of "either-or" terms.     

Influence of stage of cycle, corpus luteum location, follicle size, and number of large follicles on estradiol-17 beta concentrations in bovine follicles

Concentrations of estradiol-17 beta in follicular fluid were correlated to follicular size, stage of estrous cycle, location of corpus luteum, and presence of large follicles. Paired ovaries were obtained from 481 nonpregnant cows at slaughter and follicles were classified as ipsilateral or contralateral to the corpus luteum. Follicular fluid estradiol-17 beta concentrations from 2494 small, 1485 medium, and 396 large follicles were quantified by radioimmunoassay. Stage of estrous cycle was estimated by visual examination of the corpus luteum. Follicles in stage 1 of the estrous cycle (d 1 to 4) had the highest estradiol-17 beta concentration and the smallest mean follicular diameter. Location of follicles relative to the corpus luteum had no influence on estradiol-17 beta concentrations. As follicular size increased, concentration of estradiol-17 beta also increased. The presence of a single large follicle did not affect the concentration of estradiol-17 beta in medium or small follicles. In contrast, if multiple large follicles occurred in the same cow, concentrations of estradiol-17 beta were significantly lower in medium but not small follicles.