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Given the need for ever higher performance, and the failure of CPUs to keep providing single-threaded performance gains, engineers are increasingly turning to highly-parallel custom VLSI chips to implement expensive computations. In VLSI design, the gates and wires of a logical circuit are placed on a 2-dimensional chip with a small number of layers. Traditional VLSI models use gate delay to measure the time complexity of the chip, ignoring the lengths of wires. However, as technology has advanced, wire delay is no longer negligible; it has become an important measure in the design of VLSI chips [Markov, Nature (2014)]. Motivated by this situation, we define and study a model for VLSI chips, called wire-delay VLSI, which takes wire delay into account, going beyond an earlier model of Chazelle and Monier [JACM 1985]. - We prove nearly tight upper bounds and lower bounds (up to logarithmic factors) on the time delay of this chip model for several basic problems. For example, And, Or and Parity require Θ(n^{1/3}) delay, while Addition and Multiplication require ̃ Θ(n^{1/2}) delay, and Triangle Detection on (dense) n-node graphs requires ̃ Θ(n) delay. Interestingly, when we allow input bits to be read twice, the delay for Addition can be improved to Θ(n^{1/3}). - We also show that proving significantly higher lower bounds in our wire-delay VLSI model would imply breakthrough results in circuit lower bounds. Motivated by this barrier, we also study conditional lower bounds on the delay of chips based on the Orthogonal Vectors Hypothesis from fine-grained complexity. 

Abstract Background and Objectives Adopting healthy behaviors is often influenced by message framing; gain-framed messages emphasize the benefits of engaging in a behavior, whereas loss-framed messages highlight the consequences of not engaging in a behavior. Research has begun to uncover the underlying affective pathways involved in message framing. In the current study, we examined the role of affect in message framing to encourage exercise program enrollment among older adults. Research Design and Methods We mailed flyers to 126 volunteers assigned to a gain- or loss-framed condition and measured their affective reactions to the flyer and enrollment intentions. After the call, participants had the opportunity to contact us to enroll. Results Gain versus loss framing led to more positive affect toward the flyer, which predicted intentions and enrollment effort. In indirect effect analyses, frame indirectly influenced intentions and enrollment effort via positive affect. Discussion and Implications Although message framing plays an indirect role in influencing behavior, affect plays a central role. 

Abstract Background and Objectives Advanced age is generally associated with improved emotional well-being, but the coronavirus 2019 pandemic unleashed a global stressor that gravely threatened the physical well-being and ostensibly challenged the emotional well-being of older adults disproportionately. The current study investigated differences in emotional experiences and coping strategies between younger and older adults during the pandemic, and whether these differences were accounted for by age differences in appraisal of the pandemic. Research Design and Methods We asked younger (n = 181) and older (n = 176) adult participants to report their stress, appraisals of the pandemic, emotions, and the ways in which they were coping with the pandemic. Results Results indicated that older adults experienced less stress and less negative affect and used greater problem-focused coping and less avoidant coping in response to the pandemic than younger adults. Furthermore, age differences in affect and coping were partially accounted for by age differences in appraisals of the pandemic. Discussion and Implications Despite their objectively higher risk of illness and death due to the pandemic, older adults experienced less negative affect and used more agentic coping strategies than younger adults.