Heavy episodic drinking on college campuses: Does changing the legal drinking age make a difference

ABSTRACT. Objective: This article extends the compartmental model previously developed by Scribner et al. in the context of college drinking to a mathematical model of the consequences of lowering the legal drinking age. Method: Using data available from 32 U.S. campuses, the analyses separate underage and legal age drinking groups into an eight-compartment model with different alcohol availability (wetness) for the underage and legal age groups. The model evaluates the likelihood that underage students will incorrectly perceive normative drinking levels to be higher than they actually are (i.e., misperception) and adjust their drinking accordingly by varying the interaction between underage students in social and heavy episodic drinking compartments. Results: The results evaluate the total heavy episodic drinker population and its dependence on the difference in misperception, as well as its dependence on underage wetness, legal age wetness, and drinking age. Conclusions: Results suggest that an unrealistically extreme combination of high wetness and low enforcement would be needed for the policies related to lowering the drinking age to be effective. (J. Stud. Alcohol Drugs, 72

Overview of mathematical approaches used to model bacterial chemotaxis II: bacterial populations

We review the application of mathematical modeling to understanding the behavior of populations of chemotactic bacteria. The application of continuum mathematical models, in particular generalized Keller–Segel models, is discussed along with attempts to incorporate the microscale (individual) behavior on the macroscale, modeling the interaction between different species of bacteria, the interaction of bacteria with their environment, and methods used to obtain experimentally verified parameter values. We allude briefly to the role of modeling pattern formation in understanding collective behavior within bacterial populations. Various aspects of each model are discussed and areas for possible future research are postulated

Independent and Opposing Roles For Btk and Lyn in B and Myeloid Signaling Pathways

Transphosphorylation by Src family kinases is required for the activation of Bruton's tyrosine kinase (Btk). Differences in the phenotypes of Btk−/− and lyn−/− mice suggest that these kinases may also have independent or opposing functions. B cell development and function were examined in Btk−/−lyn−/− mice to better understand the functional interaction of Btk and Lyn in vivo. The antigen-independent phase of B lymphopoiesis was normal in Btk−/−lyn−/− mice. However, Btk−/−lyn−/− animals had a more severe immunodeficiency than Btk−/− mice. B cell numbers and response to T cell–dependent antigens were reduced. Btk and Lyn therefore play independent or partially redundant roles in the maintenance and function of peripheral B cells. Autoimmunity, hypersensitivity to B cell receptor (BCR) cross-linking, and splenomegaly caused by myeloerythroid hyperplasia were alleviated by Btk deficiency in lyn−/− mice. A transgene expressing Btk at ∼25% of endogenous levels (Btklo) was crossed onto Btk−/− and Btk−/−lyn−/− backgrounds to demonstrate that Btk is limiting for BCR signaling in the presence but not in the absence of Lyn. These observations indicate that the net outcome of Lyn function in vivo is to inhibit Btk-dependent pathways in B and myeloid cells, and that Btklo mice are a useful sensitized system to identify regulatory components of Btk signaling pathways

Students’ Perceptions of Learning Processes as Co-Authors of Digital Tabletop Activities

We conducted a small-scale study in order to explore students’ perceptions of the learning processes when engaged as co-authors of content for collaborative higher order thinking skills learning tasks. We specifically designed the process to allow for self-critique – where authors can observe their creations being solved and therefore understand where they may improve their design. We collected data over a three-day period from a sample of twelve thirteen year olds, working in teams, authoring content for Digital Mysteries (a higher order thinking skills collaborative learning application based on the digital tabletop). The study was structured to follow Bloom’s taxonomy, a continuum of cognitive skills that develop during a learning process. We found that 1) rather than follow this continuum, skills developed in a non-linear manner due to the abstract nature of the authoring activity, and 2) the students’ demonstrated good metacognitive insights into the authoring task, technology and collaborative learning as a whole

Salt restriction in kidney disease—a missed therapeutic opportunity?

The importance of salt restriction in the treatment of patients with renal disease has remained highly controversial. In the following we marshal the current evidence that salt plays a definite role in the genesis of hypertension and target organ damage, point to practical problems of salt restriction, and report on novel pathomechanisms of how salt affects blood pressure and causes target organ damage