Adaptive Contract Design for Crowdsourcing Markets: Bandit Algorithms for Repeated Principal-Agent Problems

Crowdsourcing markets have emerged as a popular platform for matching available workers with tasks to complete. The payment for a particular task is typically set by the task's requester, and may be adjusted based on the quality of the completed work, for example, through the use of "bonus" payments. In this paper, we study the requester's problem of dynamically adjusting quality-contingent payments for tasks. We consider a multi-round version of the well-known principal-agent model, whereby in each round a worker makes a strategic choice of the effort level which is not directly observable by the requester. In particular, our formulation significantly generalizes the budget-free online task pricing problems studied in prior work. We treat this problem as a multi-armed bandit problem, with each "arm" representing a potential contract. To cope with the large (and in fact, infinite) number of arms, we propose a new algorithm, AgnosticZooming, which discretizes the contract space into a finite number of regions, effectively treating each region as a single arm. This discretization is adaptively refined, so that more promising regions of the contract space are eventually discretized more finely. We analyze this algorithm, showing that it achieves regret sublinear in the time horizon and substantially improves over non-adaptive discretization (which is the only competing approach in the literature). Our results advance the state of art on several different topics: the theory of crowdsourcing markets, principal-agent problems, multi-armed bandits, and dynamic pricing.Comment: This is the full version of a paper in the ACM Conference on Economics and Computation (ACM-EC), 201

Cross-cultural Differences in Perceived Responses to Capitalization Attempts and Relationship Satisfaction

HonorsPsychologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/169388/1/xtho.pd

Resource guide for speech-language practitioners : side effects of seizure medications

textSide effects of seizure medications in individuals with intellectual disabilities (ID) may affect speech and language development for this population. Research information about these effects may be useful for speech-language pathologist practitioners, since they will most likely work in environments that involve assessing and treating individuals with ID. In this meta-analysis, a total of 19 articles were reviewed to examine the side effects of AEDs in individuals with ID and seizure disorders. Side effects from AEDs were found; however, research regarding how AEDs and seizure disorders affected speech and language development was not available. Based on the findings, participants on AEDs regimens experienced a variety of side effects that included behavioral side effects, adverse cognitive side effects, and non-behavioral side effects. However, information regarding AEDs side effects and speech and language development was nonexistent. Based on the findings, further research in this is much needed for practicing speech-language pathologists in this topic.Communication Sciences and Disorder

Evaluating the Effectiveness of Peer Engagement and Knowledge (PEAK): A Community-Based Group Intervention for Youth in Hawai‘i

This study is a program evaluation with a mixed methods design that evaluated the effectiveness of Peer Engagement and Knowledge (PEAK), a six-week community-based group intervention that incorporates mindfulness-based interventions (MBIs) to address multiple health behaviors for multiracial youth in Hilo, Hawai‘i. A total of 51 youth, ages 12-23 years old, participated in this study which included pre-/posttest analyses of health risk factors such as substance use and depression and health promoting factors such as resilience, self-esteem, and mindfulness. Responses from two subsets of participants, who engaged in a focus group (n = 11) and composed gratitude letters (n = 12), were analyzed using a thematic analysis approach. At baseline, 41.17% of youth endorsed moderate or severe levels of depressive symptomatology, 29.41% endorsed using at least one substance within the past 30 days, 94.12% endorsed high levels of resilience, 31.37% endorsed high levels of self-esteem, and 7.84% endorsed high utilization of mindfulness skills. Following their completion of PEAK, youth demonstrated statistically significant improvements on their levels of depression, resilience, self-esteem, and mindfulness scores, but not on substance use behaviors. Overall, youth’s health risk profiles improved such that the number of health risks decreased and the number of health promoting factors increased. Youth also found the MBIs to be acceptable and beneficial to their overall well-being, as it served as a positive coping strategy for stress and a mechanism to improve decision-making skills. PEAK demonstrates promise to be an effective community-based group intervention that enhances multiple health behaviors for multiracial youth in Hilo. Due to the small sample size, generalizability of results is limited. Limitations and implications for future research are also discussed

Genetic Suppression of Basement Membrane Defects in Caenorhabditis elegans by Gain of Function in Extracellular Matrix and Cell-Matrix Attachment Genes.

Basement membranes are extracellular matrices essential for embryonic development in animals. Peroxidasins are extracellular peroxidases implicated in the unique sulfilimine cross-links between type IV basement membrane collagens. Loss of function in the Caenorhabditis elegans peroxidasin PXN-2 results in fully penetrant embryonic or larval lethality. Using genetic suppressor screening, we find that the requirement for PXN-2 in development can be bypassed by gain of function in multiple genes encoding other basement membrane components, or proteins implicated in cell-matrix attachment. We identify multiple alleles of let-805, encoding the transmembrane protein myotactin, which suppress phenotypes of pxn-2 null mutants and of other basement membrane mutants such as F-spondin/spon-1 These let-805 suppressor alleles cause missense alterations in two pairs of FNIII repeats in the extracellular domain; they act dominantly and have no detectable phenotypes alone, suggesting they cause gain of function. We also identify suppressor missense mutations affecting basement membrane components type IV collagen (emb-9, let-2) and perlecan (unc-52), as well as a mutation affecting spectraplakin (vab-10), a component of the epidermal cytoskeleton. These suppressor alleles do not bypass the developmental requirement for core structural proteins of the basement membrane such as laminin or type IV collagen. In conclusion, putative gain-of-function alterations in matrix proteins or in cell-matrix receptors can overcome the requirement for certain basement membrane proteins in embryonic development, revealing previously unknown plasticity in the genetic requirements for the extracellular matrix

Cohesion in parent-adolescent relationships within different family structures and birth orders

Abstract only availablePrevious research reports relationship closeness and cohesion between parents and adolescents decrease throughout adolescence (Collins, 1990; Collins & Russell, 1991; Hill & Holmbeck, 1987). It has also been found that birth order and family structure play a role in changes in conflict and cohesion (Campione-Barr, N. & Pasch, 2008; Campione-Barr & Smetana, under review; Vandewater, E.A., & Lansford, J.E. 1998). The purpose of the present study was to examine cohesion and closeness between parents and adolescents in different family structures and birth orders. It was hypothesized that two-parent families with first-borns would have greatest cohesion, followed by two-parent later-borns, then single/step-parent family first-borns and then single/step later-borns would show lowest cohesion. Participants included 118 adolescent boys and girls in 7th and 10th grade, along with a parent. Participants were equally divided between two groups: those who were first-born in their families and those who were later-born. Three separate hierarchical regression analyses were used to test the hypotheses; one for adolescents' relationships with their mothers, one for their relationships with their fathers, and one for the participating parent's relationship with their adolescent. According to adolescents, those in two-parent families had more trust and communication with fathers than those in single or step-parent families. According to parents, trust and communication were greater in two-parent families than in step-parent families and relationships were better with first-borns than with later-borns. There were no significant effects for adolescents' reports with mothers.Emerge Summer Undergraduate Research Internshi

Salvianolic acids: small compounds with multiple mechanisms for cardiovascular protection

Salvianolic acids are the most abundant water-soluble compounds extracted from Radix Salvia miltiorrhiza (Danshen). In China, Danshen has been wildly used to treat cardiovascular diseases for hundreds of years. Salvianolic acids, especially salvianolic acid A (Sal A) and salvianolic acid B (Sal B), have been found to have potent anti-oxidative capabilities due to their polyphenolic structure. Recently, intracellular signaling pathways regulated by salvianolic acids in vascular endothelial cells, aortic smooth muscle cells, as well as cardiomyocytes, have been investigated both in vitro and in vivo upon various cardiovascular insults. It is discovered that the cardiovascular protection of salvianolic acids is not only because salvianolic acids act as reactive oxygen species scavengers, but also due to the reduction of leukocyte-endothelial adherence, inhibition of inflammation and metalloproteinases expression from aortic smooth muscle cells, and indirect regulation of immune function. Competitive binding of salvianolic acids to target proteins to interrupt protein-protein interactions has also been found to be a mechanism of cardiovascular protection by salvianolic acids. In this article, we review a variety of studies focusing on the above mentioned mechanisms. Besides, the target proteins of salvianolic acids are also described. These results of recent advances have shed new light to the development of novel therapeutic strategies for salvianolic acids to treat cardiovascular diseases