6,986 research outputs found
State Prescription Drug Price Web Sites: How Useful to Consumers?
Compares ten sites and identifies key limitations due to data omissions, gaps between insured and uninsured consumers, and varied program implementation. Presents alternative policy options such as requiring price lists from pharmacies
Design of a shim for a nanopositioner
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 37).The purpose of this thesis is to assist in the development of a low cost nanopositioner by designing a specific component - a shim that is located in the scan tip assembly of the nanopositioner. Nanopositioners must maximize precision to successfully produce features of fewer than 100 nm. The kinematic coupling used to place the tool tip is capable of producing a high level of precision across tool changes, assuming the groove mount is held in place. It is therefore very important to secure the groove mount to prevent dislocation and enhance the viability of nano-scale device fabrication. The shim developed within this thesis serves to secure the groove mount of the kinematic coupling, which was previously held in place solely with magnetic attraction. The shim secures the groove mount by applying a force to the side of the groove mount in addition to increasing the magnetic attraction between the groove mount and universal mount of the nanopositioner. It was first modeled with solid and magnetic modeling software before being manufactured and tested. With the addition of the shim, the vertical force required to displace the groove mount increased by a factor of 9.4, from 0.14 N to 1.29 N. Similarly the lateral force increased by a factor of 27.9, from 0.09 N to 2.45 N. As a result, the nanopositioner is significantly better suited to perform its function. The nanopositioner will be used to produce nano-scale devices including carbon nanotubes, molecular actuators, and transistors, with applications across several disciplines. Future work includes developing a tool to bend the shim tabs and simplify the manufacturing process.by Corey G. Harris.S.B
An Autoethnographic Review of Big Black Penis: Misadventures in Race and Masculinity
Autoethnography is a qualitative research method that allows a researcher to universalize their experience of being an individual, thus allowing others to experience their experience, be affected and continue a conversation. Big Black Penis: Misadventures in Race and Masculinity (Taylor, 2008) is a book that invites readers into the author’s experience as a Black male. As a Black male, I enter into, review, and continue the autoethnography dialogue started by Taylor. Big Black Penis is for those wanting to learn about the lived experiences of being a Black man in America
Borderlands: My Path to Becoming a Sex Therapist
Current studies focus on the practice of therapy more than the person of the therapist, which remains true in the practice of sex therapy. This study seeks to provide insight into the person-of-the-therapist by exploring the researcher’s personal journey to becoming a sex therapist. Using an autoethnography qualitative research approach, the researcher analyzed his inner experiences. The researcher demonstrated his life in the borderlands, how Eros reconciles his double-consciousness, and how this has led him to his work as a sex therapist. This study encourages readers to reflect and give voice to their own developmental experiences, adding to the collective wisdom, particularly those considering the career of sex therap
In Vivo Evaluation of the Secure Opportunistic Schemes Middleware using a Delay Tolerant Social Network
Over the past decade, online social networks (OSNs) such as Twitter and
Facebook have thrived and experienced rapid growth to over 1 billion users. A
major evolution would be to leverage the characteristics of OSNs to evaluate
the effectiveness of the many routing schemes developed by the research
community in real-world scenarios. In this paper, we showcase the Secure
Opportunistic Schemes (SOS) middleware which allows different routing schemes
to be easily implemented relieving the burden of security and connection
establishment. The feasibility of creating a delay tolerant social network is
demonstrated by using SOS to power AlleyOop Social, a secure delay tolerant
networking research platform that serves as a real-life mobile social
networking application for iOS devices. SOS and AlleyOop Social allow users to
interact, publish messages, and discover others that share common interests in
an intermittent network using Bluetooth, peer-to-peer WiFi, and infrastructure
WiFi.Comment: 6 pages, 4 figures, accepted in ICDCS 2017. arXiv admin note: text
overlap with arXiv:1702.0565
Protein Structure Prediction: The Next Generation
Over the last 10-15 years a general understanding of the chemical reaction of
protein folding has emerged from statistical mechanics. The lessons learned
from protein folding kinetics based on energy landscape ideas have benefited
protein structure prediction, in particular the development of coarse grained
models. We survey results from blind structure prediction. We explore how
second generation prediction energy functions can be developed by introducing
information from an ensemble of previously simulated structures. This procedure
relies on the assumption of a funnelled energy landscape keeping with the
principle of minimal frustration. First generation simulated structures provide
an improved input for associative memory energy functions in comparison to the
experimental protein structures chosen on the basis of sequence alignment
Isotopic replacement in ionic systems: the 4He2+ + 3He -> 3He4He+ + 4He reaction
Full quantum dynamics calculations have been carried out for the ionic
reaction 4He2+ + 3He and state-to-state reactive probabilities have been
obtained using both a time-dependent (TD) and a time-independent (TI) approach.
An accurate ab-initio potential energy surface has been employed for the
present quantum dynamics and the two sets of results are shown to be in
agreement with each other. The results for zero total angular momentum suggest
a marked presence of atom exchange (isotopic replacement) reaction with
probabilities as high as 60%. The reaction probabilities are only weakly
dependent on the initial vibrational state of the reactants while they are
slightly more sensitive to the degree of rotational excitation. A brief
discussion of the results for selected higher total angular momentum values is
also presented, while the l-shifting approximation [1] has been used to provide
estimates of the total reaction rates for the title process. Such rates are
found to be large enough to possibly become experimentally accessible
What is the best treatment for nocturnal enuresis in children?
For children with primary nocturnal enuresis,
treatment with enuresis alarms reduced the
number of wet nights by almost 4 per week, with almost half of patients remaining dry for 3 months after treatment (strength of recommendation [SOR]: A, based on a systematic review of homogeneous randomized control trials [RCTs]). Desmopressin (DDAVP) and tricyclic drugs reduce the number of wet nights by 1 to 2 per week during treatment, although the effect is not sustained after treatment is finished (SOR: A, based on a SR of homogeneous RCTs). Dry bed training with an alarm results in an additional reduction of wet nights over alarms alone (SOR: A, based on a systematic review of homogeneous RCTs]
Adiabatic Compressibility of Electrolytic Solutions and the X-Ray Diffraction Intensity Distributions
A study of the adiabatic compressibility and the X-ray diffraction intensity distributions of twenty-six strong electrolytes shows a correlation to the following extent. If one compares the rate of change of adiabatic compressibility per mole with the rate of change of the minor X-ray diffraction peak per mole in two thirds of the twenty-six samples these values increase in magnitude together. If one plots the values of the former, changing from one to eight times, and of the latter varying sixty times, the points are included within an angle of about 35° (with one exception). This approximate correspondence adds credence to the view-obtained on other grounds, that the water structure alters by the breaking of H bonds and that this is the chief cause of the variations in the adiabatic compressibility
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