It is shown that the jet mechanism derivable from the Lorentz deformation picture leads to a nearly constant average jet transverse momentum. It is pointed out that this is consistent with the high-energy experimental data. It is pointed out further that this result strengthens the physical basis for the minimal time-energy uncertainty combined covariantly with Heisenberg's space-momentum uncertainty relation.

Two experiments examined how affective values from visual and auditory modalities are integrated. Experiment 1 paired music and videos drawn from three levels of valence while holding arousal constant. Experiment 2 included a parallel combination of three levels of arousal while holding valence constant. In each experiment, participants rated their affective states after unimodal and multimodal presentations. Experiment 1 revealed a congruency effect in which stimulus combinations of the same extreme valence resulted in more extreme state ratings than component stimuli (...) presented in isolation. An interaction between music and video valence reflected the greater influence of negative affect. Video valence was found to have a significantly greater effect on combined ratings than music valence. The pattern of data was explained by a five parameter differential weight averaging model that attributed greater weight to the visual modality and increased weight with decreasing values of valence. Experiment 2 revealed a congruency effect only for high arousal combinations and no interaction effects. This pattern was explained by a three parameter constant weight averaging model with greater weight for the auditory modality and a very low arousal value for the initial state. These results demonstrate key differences in audiovisual integration between valence and arousal. (shrink)

Modern longitudinal studies collect feature data at many timepoints, often of the same order of sample size. Such studies are typically affected by dropout and positivity violations. We tackle these problems by generalizing effects of recent incremental interventions to accommodate multiple outcomes and subject dropout. We give an identifying expression for incremental intervention effects when dropout is conditionally ignorable and derive the nonparametric efficiency bound for estimating such effects. Then we present efficient nonparametric estimators, showing that they converge at fast (...) parametric rates and yield uniform inferential guarantees, even when nuisance functions are estimated flexibly at slower rates. We also study the variance ratio of incremental intervention effects relative to more conventional deterministic effects in a novel infinite time horizon setting, where the number of timepoints can grow with sample size and show that incremental intervention effects yield near-exponential gains in statistical precision in this setup. Finally, we conclude with simulations and apply our methods in a study of the effect of low-dose aspirin on pregnancy outcomes. (shrink)

We report the identification of a recurrent, 520-kb 16p12.1 microdeletion associated with childhood developmental delay. The microdeletion was detected in 20 of 11,873 cases compared with 2 of 8,540 controls and replicated in a second series of 22 of 9,254 cases compared with 6 of 6,299 controls. Most deletions were inherited, with carrier parents likely to manifest neuropsychiatric phenotypes compared to non-carrier parents. Probands were more likely to carry an additional large copy-number variant when compared to matched controls. The clinical (...) features of individuals with two mutations were distinct from and/or more severe than those of individuals carrying only the co-occurring mutation. Our data support a two-hit model in which the 16p12.1 microdeletion both predisposes to neuropsychiatric phenotypes as a single event and exacerbates neurodevelopmental phenotypes in association with other large deletions or duplications. Analysis of other microdeletions with variable expressivity indicates that this two-hit model might be more generally applicable to neuropsychiatric disease. © 2010 Nature America, Inc. All rights reserved. (shrink)

Although informed consent is important in clinical research, questions persist regarding when it is necessary, what it requires, and how it should be obtained. The standard view in research ethics is that the function of informed consent is to respect individual autonomy. However, consent processes are multidimensional and serve other ethical functions as well. These functions deserve particular attention when barriers to consent exist. We argue that consent serves seven ethically important and conceptually distinct functions. The first four functions pertain (...) principally to individual participants: (1) providing transparency; (2) allowing control and authorization; (3) promoting concordance with participants' values; and (4) protecting and promoting welfare interests. Three other functions are systemic or policy focused: (5) promoting trust; (6) satisfying regulatory requirements; and (7) promoting integrity in research. Reframing consent around these functions can guide approaches to consent that are context sensitive and that maximize achievable goals. (shrink)

BackgroundReflexive pitch perturbation experiments are commonly used to investigate the neural mechanisms underlying vocal motor control. In these experiments, the fundamental frequency–the acoustic correlate of pitch–of a speech signal is shifted unexpectedly and played back to the speaker via headphones in near real-time. In response to the shift, speakers increase or decrease their fundamental frequency in the direction opposing the shift so that their perceived pitch is closer to what they intended. The goal of the current work is to develop (...) a quantitative model of responses to reflexive perturbations that can be interpreted in terms of the physiological mechanisms underlying the response and that captures both group-mean data and individual subject responses.MethodsA model framework was established that allowed the specification of several models based on Proportional-Integral-Derivative and State-Space/Directions Into Velocities of Articulators (DIVA) model classes. The performance of 19 models was compared in fitting experimental data from two published studies. The models were evaluated in terms of their ability to capture both population-level responses and individual differences in sensorimotor control processes.ResultsA three-parameter DIVA model performed best when fitting group-mean data from both studies; this model is equivalent to a single-rate state-space model and a first-order low pass filter model. The same model also provided stable estimates of parameters across samples from individual subject data and performed among the best models to differentiate between subjects. The three parameters correspond to gains in the auditory feedback controller’s response to a perceived error, the delay of this response, and the gain of the somatosensory feedback controller’s “resistance” to this correction. Excellent fits were also obtained from a four-parameter model with an additional auditory velocity error term; this model was better able to capture multi-component reflexive responses seen in some individual subjects.ConclusionOur results demonstrate the stereotyped nature of an individual’s responses to pitch perturbations. Further, we identified a model that captures population responses to pitch perturbations and characterizes individual differences in a stable manner with parameters that relate to underlying motor control capabilities. Future work will evaluate the model in characterizing responses from individuals with communication disorders. (shrink)

When there are disasters in our society, whether on an individual, organizational or systemic level, individuals or groups of individuals are often singled out for blame, and commonly it is assumed that the alleged culprits engaged in deliberate misdeeds. But sometimes, at least, these disasters occur not because of deliberate malfeasance, but rather because of complex organizational and systemic circumstances that result in these negative outcomes. Using the Boeing Corporation and its 737 MAX aircraft crashes as an example, this ethical (...) analysis will examine some of the organizational problems that led to changes in management in Boeing and ultimately resulted in the fatal accidents. We will examine ethical blind spots within the company that led to the deadly accidents, and we will study the kinds of circumstances that are particularly acute in organizations such as Boeing, and which contributed to the malfunctions in the 737 MAX and the two resulting crashes. The Boeing 737 MAX example is not a singular case, but rather shares similarities with other engineering disasters such as the Challenger and Columbia explosions, and the ignition switch failures at General Motors each of which seem to have been at least partly the result of organizational shortcomings involving a compromise in commitment to safety. These parallels lead us to conclude that organizational malfeasance poses a serious ethical challenge for engineers and their organizations. We will conclude with some tentative suggestions for avoiding such tragic incidents in the future. (shrink)

The language $L_A(\Finv)$ is formed by adding the quantifier $\Finv x$ , "few x", to the infinitary logic L A on an admissible set A. A complete axiomatization is obtained for models whose universe is the set of ordinals of A and where $\Finv x$ is interpreted as there exist A-finitely many x. For well-behaved A, every consistent sentence has a model with an A-recursive diagram. A principal tool is forcing for $L_A(\Finv)$.

Late in 1990, the Center for the Study of Ethics in the Professions at Illinois Institute of Technology (lIT) received a grant of more than $200,000 from the National Science Foundation to try a campus-wide approach to integrating professional ethics into its technical curriculum.! Enough has now been accomplished to draw some tentative conclusions. I am the grant's principal investigator. In this paper, I shall describe what we at lIT did, what we learned, and what others, especially philosophers, can learn (...) from us. We set out to develop an approach that others could profitably adopt. I believe that we succeeded. (shrink)

The spatial dynamics of the optical emission from an array of 50 times 50 individual microcavity plasma devices is investigated. The array is operated in argon and argon-neon mixtures close to atmospheric pressure with an ac voltage. The optical emission is analysed with phase and space resolution. It has been found that the emission is not continuous over the entire ac period, but occurs once per half period. Each of the observed emission phases shows a self-pulsing of the discharge, with (...) several bursts of emission of fixed width and repetition rate. The number of emission bursts depends on applied voltage and frequency. Spatially resolved measurements prove that the emission bursts are formed by overlapping emission pulses from single discharge cavities. Intensity differences between positive and negative half-wave can be interpreted through spatially resolved measurements of single discharge cavities. (shrink)

Background: Financial conflict of interest in clinical research is an area of active debate. While data exist on the perspectives and roles of academic institutions, investigators, industry sponsors, and scientific journals, little is known about the perspectives of potential research participants.Methods: The authors surveyed potential research participants over the internet, using the Harris Interactive Chronic Illness Database. A potential research participant was defined by: self report of diagnosis by a health care professional and willingness to participate in clinical trials. Email (...) invitations were sent to 20 205 persons with coronary artery disease, breast cancer, or depression; a total of 6363 persons were screened; of these, 86% or 5478 met inclusion criteria and completed the survey. The outcome measures were respondents’ ratings on: importance of knowing conflict of interest information, whether its disclosure ought to be required, and its effect on willingness to participate—across seven widely discussed scenarios of financial conflicts of interest .Results: Majority responded that knowing conflict of interest information was “extremely” or “very” important; a larger majority felt financial conflicts of interest should be disclosed as part of informed consent . In all seven scenarios, a majority was still willing to participate but in some scenarios a sizable minority would be wary of participation. Respondents were more wary of individual than institutional conflicts of interest. Illness group and sociodemographic factors had modest effects and did not affect the main trends.Conclusions: The prevailing practice of non-disclosure of financial conflicts of interest in clinical research appears contrary to the values of potential research participants. (shrink)

Selected response items and constructed response items are often found in the same test. Conventional psychometric models for these two types of items typically focus on using the scores for correctness of the responses. Recent research suggests, however, that more information may be available from the CR items than just scores for correctness. In this study, we describe an approach in which a statistical topic model along with a diagnostic classification model was applied to a mixed item format formative test (...) of English and Language Arts. The DCM was used to estimate students’ mastery status of reading skills. These mastery statuses were then included in a topic model as covariates to predict students’ use of each of the latent topics in their written answers to a CR item. This approach enabled investigation of the effects of mastery status of reading skills on writing patterns. Results indicated that one of the skills, Integration of Knowledge and Ideas, helped detect and explain students’ writing patterns with respect to students’ use of individual topics. (shrink)

The language $L_A$ is formed by adding the quantifier $\Finv x$ , "few x", to the infinitary logic L A on an admissible set A. A complete axiomatization is obtained for models whose universe is the set of ordinals of A and where $\Finv x$ is interpreted as there exist A-finitely many x. For well-behaved A, every consistent sentence has a model with an A-recursive diagram. A principal tool is forcing for $L_A$.

While stigmatisation is universal, stigma research in low- and middle-income countries (LMIC) is limited. LMIC stigma research predominantly concerns health-related stigma, primarily regarding HIV/AIDS or mental illness from an adult perspective. While there are commonalities in stigmatisation, there are also contextual differences. The aim of this study in DR Congo (DRC), as a formative part in the development of a common stigma reduction intervention, was to gain insight into the commonalities and differences of stigma drivers (triggers of stigmatisation), facilitators (factors (...) positively or negatively influencing stigmatisation), and manifestations (practices and experiences of stigmatisation) with regard to three populations: unmarried mothers, children formerly associated with armed forces and groups (CAAFAG), and an indigenous population. Group exercises, in which participants reacted to statements and substantiated their reactions, were held with the ‘general population’ (15 exercises, n = 70) and ‘populations experiencing stigma’ (10 exercises, n = 48). Data was transcribed and translated, and coded in Nvivo12. We conducted framework analysis. There were two drivers mentioned across the three populations: perceived danger was the most prominent driver, followed by perceived low value of the population experiencing stigma. There were five shared facilitators, with livelihood and personal benefit the most comparable across the populations. Connection to family or leaders received mixed reactions. If unmarried mothers and CAAFAG were perceived to have taken advice from the general population and changed their stereotyped behaviour this also featured as a facilitator. Stigma manifested itself for the three populations at family, community, leaders and services level, with participation restrictions, differential treatment, anticipated stigma and feelings of scapegoating. Stereotyping was common, with different stereotypes regarding the three populations. Although stigmatisation was persistent, positive interactions between the general population and populations experiencing stigma were shared as well. This study demonstrated utility of a health-related stigma and discrimination framework and a participatory exercise for understanding non-health related stigmatisation. Results are consistent with other studies regarding these populations in other contexts. This study identified commonalities between drivers, facilitators and manifestations—albeit with population-specific factors. Contextual information seems helpful in proposing strategy components for stigma reduction. (shrink)