A study of citizens' apathy toward civic responsibility in two communities with contrasting socio-economic status

Thesis (M.S.)--Boston Universit

Simulating Electronic Commerce:A Game Environment Utilizing Software and Human Agents

Electronic Commerce [EC] is still in the developmental stages. Neither the technological nor the cultural constructs have solidified. The result is that there is no way of predicting what applications of EC will prosper [Kala-96]. We propose a simulation environment, that incorporates software agents and human agents in a game format to create a quasi-natural setting, for evaluating aspects of electronic commerce

Charge-voltage curves of Shaker potassium channel are not hysteretic at steady state

Charge-voltage curves of many voltage-gated ion channels exhibit hysteresis but such curves are also a direct measure of free energy of channel gating and, hence, should be path-independent. Here, we identify conditions to measure steady-state charge-voltage curves and show that these are curves are not hysteretic. Charged residues in transmembrane segments of voltage-gated ion channels (VGICs) sense and respond to changes in the electric field. The movement of these gating charges underpins voltage-dependent activation and is also a direct metric of the net free-energy of channel activation. However, for most voltage-gated ion channels, the charge-voltage (Q-V) curves appear to be dependent on initial conditions. For instance, Q-V curves of Shaker potassium channel obtained by hyperpolarizing from 0 mV is left-shifted compared to those obtained by depolarizing from a holding potential of -80 mV. This hysteresis in Q-V curves is a common feature of channels in the VGIC superfamily and raises profound questions about channel energetics because the net free-energy of channel gating is a state function and should be path independent. Due to technical limitations, conventional gating current protocols are limited to test pulse durations of \u3c500 ms, which raises the possibility that the dependence of Q-V on initial conditions reflects a lack of equilibration. Others have suggested that the hysteresis is fundamental thermodynamic property of voltage-gated ion channels and reflects energy dissipation due to measurements under non-equilibrium conditions inherent to rapid voltage jumps (Villalba-Galea. 2017. Channels. https://doi.org/10.1080/19336950.2016.1243190). Using an improved gating current and voltage-clamp fluorometry protocols, we show that the gating hysteresis arising from different initial conditions in Shaker potassium channel is eliminated with ultra-long (18-25 s) test pulses. Our study identifies a modified gating current recording protocol to obtain steady-state Q-V curves of a voltage-gated ion channel. Above all, these findings demonstrate that the gating hysteresis in Shaker channel is a kinetic phenomenon rather than a true thermodynamic property of the channel and the charge-voltage curve is a true measure of the net-free energy of channel gating

Contested Subjects: Coalition-based Activism in the Library

Upholding values of diversity and inclusion in our libraries sometimes requires concrete measures that go beyond the delivery of information resources or services. One instance of this occurred at Dartmouth College in 2014, when a group of students discovered and subsequently protested the use of the phrase “illegal aliens” in the library catalog’s controlled vocabulary. Librarians at Dartmouth, awakened by the student protest, guided the students in submitting a petition to the Library of Congress to change the heading, which later inspired members of the American Library Association to lobby on their behalf. When the Library of Congress’ Policy and Standards Division announced on March 22, 2016 its plans to replace the subject heading “Aliens” with “Noncitizens” and “Illegal aliens” with two headings, “Noncitizens” and “Unauthorized immigration,” they acknowledged that the changes came as a result of “constituent requests.” The subject heading change was reported on widely by the media, eliciting both strong support and vehement backlash nationwide. For the first time in history, members of the US House of Representatives sought to intervene in the Library of Congress’ editorial practices by legislating that the subject heading change be reversed. On a fundamental level, this story highlights the potential of librarianship to recognize and confront instances of bias in its institutional systems and structures, and to work with users to produce a more inclusive library. It also raises questions about the moral and ethical dimensions of the profession, when and how to engage in disruption, and the responsibility of librarians to protect users and fight for inclusivity and social justice. However, the range of reactions to the subject heading change indicates that this story has impact far beyond the library, representing the struggles and the provocations of the wider immigration debate in the United States. Our presentation will cover the subject heading change from its origins in a one-on-one research consultation to its current status (as of November 2016, the Library of Congress still has not been enacted the change due to political pressures, but we may see some form of resolution by May 2017). We will discuss our experiences at Dartmouth and how the movement grew beyond Dartmouth\u27s campus. Having developed out of a collective effort between undergraduate students, public services and cataloging librarians, faculty and administrators, we will also show a 7-minute video that features interviews with some of the actors in this movement in order to represent as many voices as possible

Control interface concepts for CHARA 6-telescope fringe tracking with CHAMP+MIRC

Cophasing six telescopes from the CHARA array, the CHARA-Michigan Phasetracker (CHAMP) and Michigan Infrared Combiner (MIRC) are pushing the frontiers of infrared long-baseline interferometric imaging in key scientific areas such as star- and planet-formation. Here we review our concepts and recent improvements on the CHAMP and MIRC control interfaces, which establish the communication to the real-time data recording & fringe tracking code, provide essential performance diagnostics, and assist the observer in the alignment and flux optimization procedure. For fringe detection and tracking with MIRC, we have developed a novel matrix approach, which provides predictions for the fringe positions based on cross-fringe information.Comment: 6 pages, 4 figures, published in SPIE conference proceedings (http://dx.doi.org/10.1117/12.926559

Effect of calcium supplements on risk of myocardial infarction and cardiovascular events : meta-analysis

Peer reviewedPublisher PD