1,714 research outputs found
Definition of experimental studies for determining gaseous and particulate cloud environment of manned spacecraft and applications to cometary physics Final report
Cosmic gas environment surrounding manned spacecraf
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Contrasting Experimentally Device-Manipulated and Device-Free Smiles.
Researchers in psychology have long been interested in not only studying smiles, but in examining the downstream effects of experimentally manipulated smiles. To experimentally manipulate smiles unobtrusively, participants typically hold devices (e.g., pens or chopsticks) in their mouths in a manner that activates the muscles involved in smiling. Surprisingly, despite decades of research using these methods, no study has tested to what degree these methods activate the same muscles as more natural, device-free smiles. Our study fills this gap in the literature by contrasting the magnitude of muscle activation in device-free smiles against the popular chopstick/pen manipulation. We also contrast these methods against the Smile Stick, a new device specifically designed to manipulate smiles in a comfortable and hygienic fashion. One hundred fifty-nine participants each participated in three facial expression manipulations that were held for 1 min: smile manipulation via Smile Stick, smile manipulation via chopsticks, and device-free smile. Facial electromyography was used to measure the intensity of the activation of the two main types of muscles involved in genuine, Duchenne smiling: the orbicularis oculi (a muscle group around the eyes) and the zygomaticus major (a muscle group in the cheeks). Furthermore, following each manipulation, participants rated their experience of the manipulation (i.e., comfort, fatigue, and difficulty), experienced affect (positive and negative), and levels of arousal. Results indicated that the Smile Stick and chopsticks performed equally across all measurements. Device-free smiles were rated as most comfortable but also the most fatiguing, and procured the greatest levels of positive affect and lowest levels of negative affect. Furthermore, device-free smiles resulted in significantly higher levels of both zygomaticus major (by ∼40%) and orbicularis oculi (by ∼15%) muscle activation than either the Smile Stick or chopsticks. The two devices were not different from each other in muscle activation. This study reveals that while device-free smiling procures the greatest changes in muscle activation and affect change, smiling muscle groups are activated by device manipulations, and expected changes in affect do occur, albeit to a lesser degree than device-free smiling. It also indicates that the Smile Stick is an acceptable and comparable alternative to disposable chopsticks
Laboratory and theoretical investigation of chemical release experiment Final report, 8 Oct. 1965 - 10 Nov. 1966
Chemical release experiments in upper atmospher
Direct force-measuring transducer used in blood pressure research
Direct force measuring transducer acts as an arterial tonometer, gives a direct readout to instrumentation, and is unaffected by ambient noise. It uses a semiconductor strain gage which is deflected by pressure pulses in the artery. The deflection changes the resistance of the gage and alters the voltage reading on the associated instrumentation
Elastic cavitation, tube hollowing, and differential growth in plants and biological tissues
Elastic cavitation is a well-known physical process by which elastic materials under stress can open cavities. Usually, cavitation is induced by applied loads on the elastic body. However, growing materials may generate stresses in the absence of applied loads and could induce cavity opening. Here, we demonstrate the possibility of spontaneous growth-induced cavitation in elastic materials and consider the implications of this phenomenon to biological tissues and in particular to the problem of schizogenous aerenchyma formation
When is Affect Variability Bad for Health? The Association between Affect Variability and Immune Response to the Influenza Vaccination
Objectives—This study addresses methodological and theoretical questions about the association between affect and physical health. Specifically, we examine the role of affect variability and its interaction with mean levels of affect to predict antibody (Ab) levels in response to an influenza vaccination.
Methods—Participants (N = 83) received the vaccination and completed daily diary measures of affect four times a day for 13 days. At one and four months post-vaccination, blood was collected from the participants to assess Ab levels.
Results—Findings indicate that affect variability and its interaction with mean levels of affect predict an individual’s immune response. Those high in mean positive affect (PA) who had more PA variability were more likely to have a lower Ab response in comparison to those who had high mean PA and less PA variability. Although it did not interact with mean negative affect (NA), NA variability on its own was associated with Ab response, whereby those with less NA variability mounted a more robust immune response.
Conclusion—Affect variability is related to immune response to an influenza vaccination and, in some cases, interacts with mean levels of affect. These oscillations in affective experiences are critical to consider in order to unpack the intricacies of how affect influences health. These findings suggest that future researchers should consider the important role of affect variability on physical health-relevant outcomes as well as examine the moderating effect of mean affect levels
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Misremembering pain: A memory blindness approach to adding a better end.
How people remember feeling in the past informs future decisions; however, memory for past emotion is subject to a number of biases. Previous research on choice blindness has shown that people often fail to notice when they are exposed to misinformation about their own decisions, preferences, and memories. This type of misinformation can influence how they later remember past events. In the present study, we examined the memory blindness effect in a new domain: memory for pain. Participants (N = 269) underwent a cold-pressor task and rated how much pain, distress, and positive and negative affect they had experienced. Later, participants were shown their pain ratings and asked to explain them. Some of the participants were shown lower pain ratings than they had actually made. In a second session, participants recalled how painful the task had been and how much distress and positive and negative affect they remembered experiencing. The results indicated that the majority of participants who were exposed to misinformation failed to detect the manipulation, and subsequently remembered the task as being less painful. The participants in the misinformation condition were not overall more willing to repeat the study tasks, but the participants who recalled less distress, less negative affect, and more positive affect were more willing to repeat the study tasks again in a future experiment. These results demonstrate the malleability of memory for painful experiences and that willingness to repeat aversive experiences may depend more on memory for affective reactions to the original experience than on memory for the physical pain itself
Linearly Parameterized Bandits
We consider bandit problems involving a large (possibly infinite) collection
of arms, in which the expected reward of each arm is a linear function of an
-dimensional random vector , where .
The objective is to minimize the cumulative regret and Bayes risk. When the set
of arms corresponds to the unit sphere, we prove that the regret and Bayes risk
is of order , by establishing a lower bound for an
arbitrary policy, and showing that a matching upper bound is obtained through a
policy that alternates between exploration and exploitation phases. The
phase-based policy is also shown to be effective if the set of arms satisfies a
strong convexity condition. For the case of a general set of arms, we describe
a near-optimal policy whose regret and Bayes risk admit upper bounds of the
form .Comment: 40 pages; updated results and reference
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