Nash equilibria in random games

We consider Nash equilibria in 2-player random games and analyze a simple Las Vegas algorithm for finding an equilibrium. The algorithm is combinatorial and always finds a Nash equilibrium; on m × n payoff matrices, it runs in time O(m2n log log n + n2m log lo gm) with high probability. Our result follows from showing that a 2-player random game has a Nash equilibrium with supports of size two with high probability, at least 1 − O(1 / log n). Our main tool is a polytop

African American Adults’ Experiences with the Health Care System: In Their Own Words

African Americans suffer a disproportionate burden of death and illness from a number of different chronic diseases. Inequalities in health care practices and poor patient and provider communication between African American patients and health care professionals contribute to these disparities. We describe findings from focus groups with 79 urban African Americans in which the participants discussed their interactions with the healthcare system as well as beliefs and opinions of the healthcare system and professionals. Analysis revealed five major themes: (1) historical and contextual foundations; (2) interpersonal experiences with physicians and other health care workers; (3) discrimination; (4) trust, opinions and attitudes, and (5) improving health care experiences. These findings indicate that perceptions of discrimination and racism were prevalent among African Americans in this study, and that the expectation of a negative interaction is a barrier to seeking care. Authors discuss prevention and public health implications of these findings and make recommendations for health care practitioners

Use of culturally focused theoretical frameworks for adapting diabetes prevention programs: A qualitative review

INTRODUCTION: Diabetes disproportionately affects underserved racial/ethnic groups in the United States. Diabetes prevention interventions positively influence health; however, further evaluation is necessary to determine what role culture plays in effective programming. We report on the status of research that examines cultural adaptations of diabetes prevention programs. METHODS: We conducted database searches in March and April 2014. We included studies that were conducted in the United States and that focused on diabetes prevention among African Americans, American Indians/Alaska Natives, Asian Americans/Pacific Islanders, and Latinos. RESULTS: A total of 58 studies were identified for review; 29 were excluded from evaluation. Few adaptations referenced or followed recommendations for cultural adaptation nor did they justify the content modifications by providing a rationale or evidence. Cultural elements unique to racial/ethnic populations were not assessed. CONCLUSION: Future cultural adaptations should use recommended processes to ensure that culture’s role in diabetes prevention–related behavioral changes contributes to research

On the odd-minor variant of Hadwiger's conjecture

A {\it $K_l$ -expansion} consists of $l$ vertex-disjoint trees, every two of which are joined by an edge. We call such an expansion {\it odd} if its vertices can be two-coloured so that the edges of the trees are bichromatic but the edges between trees are monochromatic. We show that, for every $l$, if a graph contains no odd $K_l$ -expansion then its chromatic number is $O(l \sqrt{\log l})$. In doing so, we obtain a characterization of graphs which contain no odd $K_l$ -expansion which is of independent interest. We also prove that given a graph and a subset $S$ of its vertex set, either there are $k$ vertex-disjoint odd paths with endpoints in $S$, or there is a set X of at most $2k − 2$ vertices such that every odd path with both ends in $S$ contains a vertex in $X$. Finally, we discuss the algorithmic implications of these results

On the odd-minor variant of Hadwiger's conjecture

A {\it $K_l$ -expansion} consists of $l$ vertex-disjoint trees, every two of which are joined by an edge. We call such an expansion {\it odd} if its vertices can be two-coloured so that the edges of the trees are bichromatic but the edges between trees are monochromatic. We show that, for every $l$, if a graph contains no odd $K_l$ -expansion then its chromatic number is $O(l \sqrt{\log l})$. In doing so, we obtain a characterization of graphs which contain no odd $K_l$ -expansion which is of independent interest. We also prove that given a graph and a subset $S$ of its vertex set, either there are $k$ vertex-disjoint odd paths with endpoints in $S$, or there is a set X of at most $2k − 2$ vertices such that every odd path with both ends in $S$ contains a vertex in $X$. Finally, we discuss the algorithmic implications of these results

Perceptions of the US National Tobacco Quitline among adolescents and adults: A qualitative study, 2012–2013

INTRODUCTION: Tobacco quitlines are critical components of comprehensive tobacco control programs. However, use of the US National Tobacco Quitline (1-800-QUIT-NOW) is low. Promoting quitlines on cigarette warning labels may increase call volume and smoking cessation rates but only if smokers are aware of, and receptive to, quitline services. METHODS: We conducted qualitative interviews with a diverse subset (n = 159) of adolescent (14–17 y) and adult (≥18 y) participants of a larger quantitative survey about graphic cigarette warning labels (N = 1,590). A convenience sample was recruited from schools and community organizations in 6 states. Interviews lasted 30 to 45 minutes and included questions to assess basic knowledge and perceptions of the quitline number printed on the warning labels. Data were analyzed using content analysis. RESULTS: Four themes were identified: available services, caller characteristics, quitline service provider characteristics, and logistics. Participants were generally knowledgeable about quitline services, including the provision of telephone-based counseling. However, some adolescents believed that quitlines provide referrals to “rehab.” Quitline callers are perceived as highly motivated — even desperate — to quit. Few smokers were interested in calling the quitline, but some indicated that they might call if they were unable to quit independently. It was generally recognized that quitline services are or should be free, confidential, and operated by governmental or nonprofit agencies, possibly using tobacco settlement funds. CONCLUSION: Future marketing efforts should raise awareness of the nature and benefits of quitline services to increase use of these services and, consequently, reduce tobacco use, improve public health, and reduce tobacco-related health disparities

A tale of two community networks program centers: Operationalizing and assessing CBPR principles and evaluating partnership outcomes

BACKGROUND: Community Networks Program (CNP) centers are required to use a community-based participatory research (CBPR) approach within their specific priority communities. Not all communities are the same and unique contextual factors and collaborators’ priorities shape each CBPR partnership. There are also established CBPR and community engagement (CE) principles shown to lead to quality CBPR in any community. However, operationalizing and assessing CBPR principles and partnership outcomes to understand the conditions and processes in CBPR that lead to achieving program and project level goals is relatively new in the science of CBPR. OBJECTIVES: We sought to describe the development of surveys on adherence to and implementation of CBPR/CE principles at two CNP centers and examine commonalities and differences in program- versus project-level CBPR evaluation. METHODS: A case study about the development and application of CBPR/CE principles for the Missouri CNP, Program for the Elimination of Cancer Disparities, and Minnesota CNP, Padres Informados/Jovenes Preparados, surveys was conducted to compare project versus program operationalization of principles. Survey participant demographics were provided by CNP. Specific domains found in CBPR/CE principles were identified and organized under an existing framework to establish a common ground. Operational definitions and the number of survey items were provided for each domain by CNP. CONCLUSION: There are distinct differences in operational definitions of CBPR/CE principles at the program and project levels of evaluation. However, commonalities support further research to develop standards for CBPR evaluation across partnerships and at the program and project levels

Schedule-selective biochemical modulation of 5-fluorouracil in advanced colorectal cancer – a phase II study

BACKGROUND: 5-fluorouracil remains the standard therapy for patients with advanced/metastatic colorectal cancer. Pre-clinical studies have demonstrated the biological modulation of 5-fluorouracil by methotrexate and leucovorin. This phase II study was initiated to determine the activity and toxicity of sequential methotrexate – leucovorin and 5-fluorouracil chemotherapy in patients with advanced colorectal cancer. METHODS: Ninety-seven patients with metastatic colorectal cancer were enrolled onto the study. Methotrexate – 30 mg/m(2) was administered every 6 hours for 6 doses followed by a 2 hour infusion of LV – 500 mg/m(2). Midway through the leucovorin infusion, patients received 5-fluorouracil – 600 mg/m(2). This constituted a cycle of therapy and was repeated every 2 weeks until progression. RESULTS: The median age was 64 yrs (34–84) and the Eastern Cooperative Group Oncology performance score was 0 in 37%, 1 in 55% and 2 in 8% of patients. Partial and complete responses were seen in 31% of patients with a median duration of response of 6.4 months. The overall median survival was 13.0 months. The estimated 1-year survival was 53.7%. Grade III and IV toxic effects were modest and included mucositis, nausea and vomiting. CONCLUSIONS: This phase II study supports previously reported data demonstrating the modest clinical benefit of 5-FU modulation utilizing methotrexate and leucovorin in patients with metastatic colorectal cancer. Ongoing studies evaluating 5-fluorouracil modulation with more novel agents (Irinotecan and/or oxaliplatin) are in progress and may prove encouraging