The Ethics of Placebo-controlled Trials: Methodological Justifications

The use of placebo controls in clinical trials remains controversial. Ethical analysis and international ethical guidance permit the use of placebo controls in randomized trials when scientifically indicated in four cases: (1) when there is no proven effective treatment for the condition under study; (2) when withholding treatment poses negligible risks to participants; (3) when there are compelling methodological reasons for using placebo, and withholding treatment does not pose a risk of serious harm to participants; and, more controversially, (4) when there are compelling methodological reasons for using placebo, and the research is intended to develop interventions that can be implemented in the population from which trial participants are drawn, and the trial does not require participants to forgo treatment they would otherwise receive. The concept of methodological reasons is essential to assessing the ethics of placebo controls in these controversial last two cases. This article sets out key considerations relevant to considering whether methodological reasons for a placebo control are compelling

How the News Frames Child Maltreatment: Unintended Consequences

While advocates are usually gratified to see attention paid to their issue in the news, the coverage can often be a mixed blessing, as research by the FrameWorks Institute and others has shown. It is the way that stories are told in the news that affects public thinking, and many of these stories do not guide thinking in constructive directions. A story that seems to convey important information may also have unintended, damaging consequences for public understanding and engagement. This document summarizes some of the major patterns in news coverage of child maltreatment -- the key narratives, frames and causal stories that are conveyed to the public on the issue. The material for the analysis includes a collection of roughly 120 news articles collected by Prevent Child Abuse America and Cultural Logic. Additionally, the review included a collection of several dozen TV news stories assembled by the Center for Communications and Community at UCLA. The premise behind this study is that once advocates have a better idea about the way their issue is portrayed in the media, they can be strategic about choosing which narratives to reinforce, which to challenge, and which to downplay. A close examination of news coverage also gives advocates a window into what they are up against as they try to increase public engagement. This research analysis is part of New FrameWorks Research on Child Abuse and Neglect Prevention, and was conducted in collaboration with the FrameWorks Institute, and commissioned by Prevent Child Abuse America, with funding from the Doris Duke Charitable Foundation. Please visit our website for more information

Two Cognitive Obstacles to Preventing Child Abuse: The 'Other Mind' Mistake and the 'Family Bubble'

Following decades of effective publicity about the issue, Americans are now aware of the horrors of child abuse and have an idea (even an exaggerated idea) of the pervasiveness of all types of maltreatment. Making further headway in engaging the public on the issue will have to involve more than raising the volume on awareness campaigns. Such campaigns can even backfire by intensifying the public's media-fed association between abuse and sensational crimes -- which only "sick monsters" could commit and no programs can ever totally eliminate.To take the public to the next step in engagement, communications will need to address counterproductive patterns of reasoning that hinder better understanding of the issue. One of the most pervasive of these is the "Other-Minds" mistake: Lay people misperceive a child as a little mind which develops through abstract processes like learning, memory and choice; or which does not "develop" at all, and exists from the beginning as something like an adult mind which just needs to be "filled" or "guided." This fallacy effectively obscures any scientific understanding of development of biological systems which guide these and all other aspects of behavior. This fallacy is natural, we suggest, because of a highly evolved (and very useful) human mechanism for interpreting the content of Other-Minds (known to psychologists as the "Other-Minds module"). While the "Other-Minds" module is extremely useful for trying to read the minds of other adults, it also leads to a number of distortions that make child maltreatment more likely to happen, and less likely to be prevented. These distortions include a tendency to believe that an infant has an "agenda" that conflicts with ours; an exaggerated sense of children's ability to "get past" abuse through force of will; a sense that even one year-old children can benefit from punishment for breaking moral rules; and a difficulty understanding the concept of "neglect" except as something like "underinvolvement;" among others. An additional cognitive obstacle which communications need to address is the "Family Bubble" -- the default mode of thinking in which events within the family (including child rearing and child maltreatment) take place in a sphere that is separate and different from the public sphere. This default understanding is stronger than a mere belief that families should be autonomous. It means that even thinking about the interaction between child rearing and public policy is difficult for people, and that communications based on reinforcing the "Village," while appealing, can lead to conflictedness rather than change. This research analysis is part of New FrameWorks Research on Child Abuse and Neglect Prevention, and was conducted in collaboration with the FrameWorks Institute, and commissioned by Prevent Child Abuse America, with funding from the Doris Duke Charitable Foundation

Fracture toughness testing of polymer matrix composites

A review of the interlaminar fracture indicates that a standard specimen geometry is needed to obtain consistent fracture toughness measurements in polymer matrix composites. In general, the variability of measured toughness values increases as the toughness of the material increases. This variability could be caused by incorrect sizing of test specimens and/or inconsistent data reduction procedures. A standard data reduction procedure is therefore needed as well, particularly for the tougher materials. Little work has been reported on the effects of fiber orientation, fiber architecture, fiber surface treatment or interlaminar fracture toughness, and the mechanisms by which the fibers increase fracture toughness are not well understood. The little data that is available indicates that woven fiber reinforcement and fiber sizings can significantly increase interlaminar fracture toughness

Vibration testing of impact-damaged composite laminates

A new test is described that can be used to measure changes in the vibration properties of impact damaged composite materials. Impact-induced delamination was observed to significantly affect natural frequencies of vibration and damping properties in cross-ply graphite/epoxy laminates. Natural frequencies are shown to drop by as much as half of their original value, and modal damping ratios can increase by a factor of up to eight when large amounts of damage are present. A simple finite element model of the damaged impact specimens was used to predict the effect of delamination on certain vibration properties. A comparison of the finite element calculations with the experimental measurements suggests that delamination was the dominant mechanism of flexural stiffness loss resulting from the transverse impact

Effect of heat treatment on stiffness and damping of SiC/Ti-15-3

The effect of heat treatment on material properties of SiC/Ti-15-3 was measured by vibration tests. Heat treatment changes the microstructure, which was found to stiffen the matrix and reduce its damping capacity. Test results indicate how these changes in the matrix affect the corresponding properties of the composite. Measurements show that heat treatment affects damping properties of the composite to a greater extent than stiffness properties. The extent of change in mechanical properties is shown to depend on heat treatment temperature and exposure time

A NASTRAN DMAP alter for linear buckling analysis under dynamic loading

A unique modification to the NASTRAN solution sequence for transient analysis with direct time integration (COSMIC NASTRAN rigid format 9) was developed and incorporated into a DMAP alter. This DMAP alter calculates the buckling stability of a dynamically loaded structure, and is used to predict the onset of structural buckling under stress wave loading conditions. The modified solution sequence incorporates the linear buckling analysis capability (rigid format 5) of NASTRAN into the existing Transient solution rigid format in such a way as to provide a time dependent eigensolution which is used to assess the buckling stability of the structure as it responds to the impulsive load. As a demonstration of the validity of this modified solution procedure, the dynamic buckling of a prismatic bar subjected to an impulsive longitudinal compression is analyzed and compared to the known theoretical solution. In addition, a dynamic buckling analysis is performed for the analytically less tractable problem of the localized dynamic buckling of an initially flawed composite laminate under transverse impact loading. The addition of this DMAP alter to the transient solution sequence in NASTRAN facilitates the prediction of both time and mode of buckling

Evaluation of thermal and mechanical loading effects on the structural behavior of a SiC/titanium composite

Composite specimens of titanium-15-3 matrix reinforced with continuous SCS-6 silicon carbide fibers were tested under a variety of thermal and mechanical loadings. A combined experimental/finite element approach was used to estimate the effective in-situ modulus of the matrix material and to evaluate changes in modulus due to the applied loads. Several fiber orientations were tested. Results indicate that the effect of the thermal loads on composite stiffness varies with fiber orientation. Applications of this method to test specimens damaged by uniaxial tension, thermal cycling, and isothermal fatigue loadings are used to illustrate that by monitoring overall structural behavior, changes in stiffness caused by thermomechanical loading can be detected