Energetics of ion competition in the DEKA selectivity filter of neuronal sodium channels

The energetics of ionic selectivity in the neuronal sodium channels is studied. A simple model constructed for the selectivity filter of the channel is used. The selectivity filter of this channel type contains aspartate (D), glutamate (E), lysine (K), and alanine (A) residues (the DEKA locus). We use Grand Canonical Monte Carlo simulations to compute equilibrium binding selectivity in the selectivity filter and to obtain various terms of the excess chemical potential from a particle insertion procedure based on Widom's method. We show that K$^{+}$ ions in competition with Na$^{+}$ are efficiently excluded from the selectivity filter due to entropic hard sphere exclusion. The dielectric constant of protein has no effect on this selectivity. Ca$^{2+}$ ions, on the other hand, are excluded from the filter due to a free energetic penalty which is enhanced by the low dielectric constant of protein.Comment: 14 pages, 7 figure

What Are Kinship Terminologies, and Why Do We Care? A Computational Approach to Analyzing Symbolic Domains

Kinship is a fundamental feature and basis of human societies. We describe a set of computational tools and services, the Kinship Algebra Modeler, and the logic that underlies these. These were developed to improve how we understand both the fundamental facts of kinship, and how people use kinship as a resource in their lives. Mathematical formalism applied to cultural concepts is more than an exercise in model building, as it provides a way to represent and explore logical consistency and implications. The logic underlying kinship is explored here through the kin term computations made by users of a terminology when computing the kinship relation one person has to another by referring to a third person for whom each has a kin term relationship. Kinship Algebra Modeler provides a set of tools, services and an architecture to explore kinship terminologies and their properties in an accessible manner

Robust (and Backward) Instructional Design for an Online Information Literacy Course

Online information literacy courses have been taught for credit at The Ohio State University for over a decade with only minor or technology-driven changes. A small team of librarians within the Teaching & Learning Unit overhauled the course using the latest research and emerging trends in information behavior to create a more engaging, evidence-based class. Preparation for and development of the new course also included workshops and consultations with various departments on campus, including the University Center for the Advancement of Teaching, the Center for the Study and Teaching of Writing, and the Digital Union (a learning technology department). In this presentation, the team leader will describe how they used the backwards design process and other frameworks to build the best online course possible. Additionally, the pedagogical theories and philosophies that served as foundation for the design will be briefly discussed. Attendees will learn in an open dialogue the granular details of the inherently ill-structured online course design process, recommended best practices, and potential pitfalls

Schwinger, Pegg and Barnett and a relationship between angular and Cartesian quantum descriptions

From a development of an original idea due to Schwinger, it is shown that it is possible to recover, from the quantum description of a degree of freedom characterized by a finite number of states (\QTR{it}{i.e}., without classical counterpart) the usual canonical variables of position/momentum \QTR{it}{and} angle/angular momentum, relating, maybe surprisingly, the first as a limit of the later.Comment: 7 pages, revised version, to appear on J. Phys. A: Math and Ge

Developing a Visualization Tool for Archived Social Science Research Data

When researchers access electronically-archived datasets, is the information readily comprehensible? For survey research, this is often not the case. When online surveys use skip patterns, the path respondents take through the survey will vary depending on how each question is answered. Such skip logic programming is not always obvious when looking at the linear version of the survey instrument. Using the Workforce Issues in Library and Information Science (WILIS) surveys as test cases, a schema was designed to visualize the flow and logic of complex surveys. Wireframes were created to illustrate the schema's potential use as an analysis tool within the open-source Dataverse Network maintained by the Odum Institute for Research in Social Science. Focus groups were used to explore responses to the survey visualization tool by researchers

Enhancing Nanoparticle Accumulation and Retention in Desmoplastic Tumors via Vascular Disruption for Internal Radiation Therapy

Aggressive, desmoplastic tumors are notoriously difficult to treat because of their extensive stroma, high interstitial pressure, and resistant tumor microenvironment. We have developed a combination therapy that can significantly slow the growth of large, stroma-rich tumors by causing massive apoptosis in the tumor center while simultaneously increasing nanoparticle uptake through a treatment-induced increase in the accumulation and retention of nanoparticles in the tumor. The vascular disrupting agent Combretastatin A-4 Phosphate (CA4P) is able to increase the accumulation of radiation-containing nanoparticles for internal radiation therapy, and the retention of these delivered radioisotopes is maintained over several days. We use ultrasound to measure the effect of CA4P in live tumor-bearing mice, and we encapsulate the radio-theranostic isotope 177Lutetium as a therapeutic agent as well as a means to measure nanoparticle accumulation and retention in the tumor. This combination therapy induces prolonged apoptosis in the tumor, decreasing both the fibroblast and total cell density and allowing further tumor growth inhibition using a cisplatin-containing nanoparticle

Identification of Violence in the Home - Pediatric and Parental Reports

Objectives: To compare the rates of domestic violence reported by mothers with those identified by physicians, to compare the rates of harsh discipline practices reported by mothers with the rates of abuse identified by physicians, and to examine the relationship between reported domestic violence and harsh discipline practices. Design: Interviews with parents and pediatricians to compare pediatric detection of domestic violence and child abuse with parental reports of domestic violence and harsh discipline practices. Setting: Community-based pediatric practices in the 13-town greater New Haven, Conn, area. Participants: Of the 23 practices invited, 19 agreed to participate. Of the 2006 parents of eligible 4- to 8-year-olds asked to participate, 1886 (94%) completed the Child Behavior Checklist. Of those invited into the interview portion, 1148 (83%) completed the 90-minute in-person interview. Main Outcome Measures: Percentages of cases of domestic violence identified by pediatricians and reported by mothers. Percentages of cases of child abuse detected by pediatricians and percentages of mothers reporting that they have hit their children and left a mark. Results: Pediatricians detected domestic violence in 0.3% of the cases, but parents reported domestic violence in 4.2% (kappa = 0.106 [95% confidence interval, -0.007 to 0.219]). Pediatricians identified physical abuse of children in 0.5% of the cases, while mothers reported hitting their children and leaving a mark in 21.6% (kappa = 0.003 [95% confidence interval, -0.018 to 0.024]). Mothers reporting domestic violence were significantly more likely to report hitting hard enough to leave a mark (relative risk, 1.6 ([95% confidence interval, 1.09-2.38]) compared with those not reporting domestic violence. Physicians identifying domestic violence were not significantly more likely to report child abuse than those not identifying domestic violence. Conclusions: Parents report more cases of violence than pediatricians detect. Pediatricians should ask parents directly about domestic violence and harsh discipline