The President and Nuclear Weapons: Authorities, Limits, and Process

There is no more consequential decision for a president than ordering a nuclear strike. In the Cold War, the threat of sudden nuclear annihilation necessitated procedures emphasizing speed and efficiency and placing sole decision-making authority in the president’s hands. In today’s changed threat environment, the legal authorities and process a U.S. president would confront when making this grave decision merit reexamination. This paper serves as a resource in the national discussion about a president’s legal authority and the procedures for ordering a nuclear strike, and whether to update them

Switchable coatings for Biomedical applications

Bellingham, Washingto

Clearing the Path for First-Generation College Students:Qualitative and Intersectional Studies of Educational Mobility

Clearing the Path for First-Generation College Students comprises a wide range of studies that explore the multidimensional social processes and meanings germane to the experiences of first-generation college students before and during their matriculation into institutions of higher education. The chapters offer timely, empirical examinations of the ways that these students negotiate experiences shaped by structural inequities in higher education institutions and the pathways that lead to them. This volume provides insight into the dilemmas that arise from the transformation of students’ class identities in pursuit of upward mobility, as well as their quest for community and a sense of “belonging” on college campuses that have not been historically designed for them. While centering first-generation status, this collection also critically engages the ways in which other dimensions of social identity intersect to inform students’ educational experiences in relation to dynamics of race, ethnicity, socioeconomic class, gender, and immigration. Additionally, this book takes a holistic approach by exploring the ways in which first-generation college students are influenced by, and engage with, their families and communities of origin as they undertake their educational careers.https://scholarship.richmond.edu/bookshelf/1305/thumbnail.jp

Using sulcal and gyral measures of brain structure to investigate benefits of an active lifestyle

Background: Physical activity is associated with brain and cognitive health in ageing. Higher levels of physical activity are linked to larger cerebral volumes, lower rates of atrophy, better cognitive function and lesser risk of cognitive decline and dementia. Neuroimaging studies have traditionally focused on volumetric brain tissue 17 measures to test associations between factors of interest (e.g. physical activity) and brain structure. However, cortical sulci may provide additional information to these more standard measures. Method: Associations between physical activity, brain structure, and cognition were investigated in a large, community-based sample of cognitively healthy individuals (N = 317) using both sulcal and volumetric measures. Results: Physical activity was associated with narrower width of the Left Superior Frontal Sulcus and the Right Central Sulcus,while volumetric measures showed no association with physical activity. In addition, Left Superior Frontal Sulcal width was associated with processing speed and executive function. Discussion: These findings suggest sulcalmeasuresmay be a sensitive index of physical activity related to cerebral health and cognitive function in healthy older individuals. Further research is required to confirm these findings and to examine how sulcal measures may be most effectively used in neuroimaging

Haptics and directional audio using acoustic metasurfaces

The ability to control acoustic fields offers many possible applications in loudspeaker design, ultrasound imaging, medical therapy, and acoustic levitation. Sound waves are currently shaped using phased array systems, even though the complex electronics required are expensive and hinder widespread use. Here we show how to control, direct, and manipulate sound using 2-dimensional, planar, acoustic metasurfaces that require only one driving signal. This offers the advantages of ease of use and versatility over currently available phased arrays. We demonstrate the creation of a haptic sensation and steering of a beam produced by a parametric speaker. This simple, yet highly effective, method of creating single-beam manipulators could be introduced in medical or manufacturing applications

Effects of eating rate on satiety:A role for episodic memory?

AbstractEating slowly is associated with a lower body mass index. However, the underlying mechanism is poorly understood. Here, our objective was to determine whether eating a meal at a slow rate improves episodic memory for the meal and promotes satiety. Participants (N=40) consumed a 400ml portion of tomato soup at either a fast (1.97ml/s) or a slow (0.50ml/s) rate. Appetite ratings were elicited at baseline and at the end of the meal (satiation). Satiety was assessed using; i) an ad libitum biscuit ‘taste test’ (3h after the meal) and ii) appetite ratings (collected 2h after the meal and after the ad libitum snack). Finally, to evaluate episodic memory for the meal, participants self-served the volume of soup that they believed they had consumed earlier (portion size memory) and completed a rating of memory ‘vividness’. Participants who consumed the soup slowly reported a greater increase in fullness, both at the end of the meal and during the inter-meal interval. However, we found little effect of eating rate on subsequent ad libitum snack intake. Importantly, after 3h, participants who ate the soup slowly remembered eating a larger portion. These findings show that eating slowly promotes self-reported satiation and satiety. For the first time, they also suggest that eating rate influences portion size memory. However, eating slowly did not affect ratings of memory vividness and we found little evidence for a relationship between episodic memory and satiety. Therefore, we are unable to conclude that episodic memory mediates effects of eating rate on satiety

Switchable surface coatings for control over protein adsorption

Control over biomolecule interactions at interfaces is becoming an increasingly important goal for a range of scientific fields and is being intensively studied in areas of biotechnological, biomedical and materials science. Improvement in the control over materials and biomolecules is particularly important to applications such as arrays, biosensors, tissue engineering, drug delivery and 'lab on a chip' devices. Further development of these devices is expected to be achieved with thin coatings of stimuli responsive materials that can have their chemical properties 'switched' or tuned to stimulate a certain biological response such as adsorptionldesorption of proteins. Switchable coatings show great potential for the realisation of spatial and temporal immobilisation of cells and biomolecules such as DNA and proteins. This study focuses on protein adsorption onto coatings of the thermosensitive polymer poly(N-isopropylacrylamide) (pNIPAM) which can exhibit low and high protein adsorption properties based on its temperature dependent conformation. At temperatures above its lower critical solution temperature (LCST) pNIPAM polymer chains are collapsed and protein adsorbing whilst below the LCST they are hydrated and protein repellent. Coatings of pNIPAM on silicon wafers were prepared by free radical polymerisation in the presence of surface bound polymerisable groups. Surface analysis and protein adsorption was carried out using X-ray photoelectron spectroscopy, time of flight secondary ion mass spectrometry and contact angle measurements. This study is expected to aid the development of stimuli-responsive coatings for biochips and biodevices.Bellingham, US

The effect of perceived appearance judgements on psychological and biological stress processes across adulthood

Social self-preservation theory posits that stress is experienced when an aspect of an individual's identity has the potential to be negatively evaluated. Appearance is a central part of identity; however, little research has examined whether perceived appearance judgements are a source of social-evaluative stress. In addition, stress may be an explanatory link in the association between appearance perceptions and depressive symptoms. This study examined whether perceived appearance judgements were associated with increased stress and greater depressive symptoms among adults. Study 1 examined the associations between self-reported appearance judgements and cortisol stress responses in response to a laboratory stressor (Trier Social Stress Test) among 71 individuals aged 18–65. Study 2 assessed self-reported appearance judgements and depressive symptoms among 498 adults ages 18–65 via an online survey data collection. Appearance judgement was associated with a stronger cortisol response, higher self-reported stress, and greater depressive symptoms. Stress mediated all associations between appearance judgements and depressive symptoms and neither age nor gender moderated these associations. The findings suggest that appearance judgements contribute to psychological and biological stress processes and demonstrated that stress mediated the association between appearance judgements and depressive symptoms