Margaret M. Byrne

Ecology of twig-dwelling ants in a wet lowland tropical forest

Ants of tropical wet forests are common, yet practically unstudied, despite their importance in nutrient cycling and seed bank dynamics. I investigated the ecology of a leaf litter assemblage of twig-dwelling ants in lowland tropical wet forest and contrasted it with the better known ecologies of ground- and tree-dwelling ants. Nest densities at La Selva, Costa Rica were high (7.48 nests/m 2 ) and potential nest sites were abundant. Colonies moved frequently (residence times for species ranged from 35 to 146 days) from one twig nest to another, occupying a wide range of twig types. Experiments with artificial nests showed that colonization was not reduced by the presence of resident ant colonies

African American and Poor Patients Have a Dramatically Worse Prognosis for Head and Neck Cancer : An Examination of 20,915 Patients

Differences in cancer survival based on race, ethnicity, and socioeconomic status (SES) are a major issue. To identify points of intervention and improve survival, the authors sought to determine the impact of race, ethnicity, and socioeconomic status for patients with cancers of the head and neck (HN).

Is surgical resection superior to transplantation in the treatment of hepatocellular carcinoma

Objective:To compare outcomes for patients with hepatocellular carcinoma (HCC) treated with either liver resection or transplantation. Methods:A retrospective, single-institution analysis of 413 HCC patients from 1999 to 2009. Results:A total of 413 patients with HCC underwent surgical resection (n = 106) and transplantation (n = 270) or were listed without receiving transplantation (n = 37). Excluding transplanted patients with incidental tumors (n = 50), 257 patients with suspected HCC were listed with the intent to transplant (ITT). The median diameter of the largest tumor by radiography was 6.0 cm in resected, 3.0 cm in transplanted, and 3.4 cm in the listed-but-not-transplanted patients. Median time to transplant was 48 days. Recurrence rates were 19.8% for resection and 12.1% for all ITT patients. Overall, patient survival for resection versus ITT patients was similar (5-year survival of 53.0% vs 52.0%, not significant). However, for HCC patients with model end-stage liver disease (MELD) scores less than 10 and who radiologically met Milan or UCSF (University of California, San Francisco) criteria, 1-year and 5-year survival rates were significantly improved in resected patients. For patients with MELD score less than 10 and who met Milan criteria, 1-year and 5-year survival were 92.0% and 63.0% for resection (n = 26) versus 83.0% and 41.0% for ITT (n = 73, P = 0.036). For those with MELD score less than 10 and met UCSF criteria, 1-year and 5-year survival was 94.0% and 62.0% for resection (n = 33) versus 81.0% and 40.0% for ITT (n = 78, P = 0.027). Conclusions:Among known HCC patients with preserved liver function, resection was associated with superior patient survival versus transplantation. These results suggest that surgical resection should remain the first line therapy for patients with HCC and compensated liver function who are candidates for resection.

Relationship between clinical conditions and use of veterans affairs health care among Medicare-enrolled veterans

OBJECTIVE To determine how reliance on Veterans Affairs (VA) for medical care among veterans enrolled in Medicare is affected by medical conditions, access, and patient characteristics. DATA SOURCES/STUDY SETTING Department of Veterans Affairs. STUDY DESIGN We examined reliance on the VA for inpatient, outpatient, and overall medical care among all VA users in fiscal years 2003 and 2004 who were also enrolled in Medicare. We calculated the marginal effects of patient factors on VA reliance using fractional logistic regression; we also analyzed overall VA reliance separately for under-65 and age-65+ groups. The primary focus of this analysis was the relationship between aggregated condition categories (ACCs), which represent medical conditions, and reliance on the VA. PRINCIPAL FINDINGS Mean VA reliance was significantly higher in the under-65 population than in the age-65+ group (0.800 versus 0.531). Lower differential distance to the VA, and higher VA-determined priority for health care, predicted higher VA reliance. Most individual ACCs were negatively associated with VA reliance, though substance abuse and mental health disorders were significantly associated with increased reliance on VA care. Conditions of the eyes and ears/nose/throat had positive marginal effect on VA reliance for the under 65, while diabetes was positive for age 65+. Among inpatients, veterans with ACCs for mental health conditions, eye conditions, amputations, or infectious and parasitic conditions had higher likelihood of a VA hospitalization than inpatients without these conditions. CONCLUSIONS Many dually enrolled Veterans use both Medicare and VA health care. Age, accessibility, and priority level for VA services have a clear relationship with VA reliance. Because dual use is common, coordination of care among health care settings for such patients should be a policy priority.

Anxiety, Fear of Cancer, and Perceived Risk of Cancer following Lung Cancer Screening

Background. Lung cancer screening can result in a high rate of indeterminate findings and has not yet been proven to be efficacious in reducing mortality. To date, the psychological consequences of receiving an indeterminate screening result are not known. Methods. Four hundred individuals were recruited into this study. Participants completed 4 surveys: baseline, after lung screening results were known, and at 6 and 12 mo after screening. Demographics, state/trait anxiety, fear of cancer, and perceived risk of lung cancer were measured. Mixed-model regressions were used to determine whether the levels and time trends of outcome variables were different among individuals with different screening outcomes. Results. An indeterminate screening result increased state anxiety of participants, although anxiety then decreased over time. The objective risk of cancer is lower for individuals with an indeterminate screen than their initial perceived risk, and screening did not change their perceived risk of cancer. Those with a suspicious screening result had increased perceived risk of cancer and fear of cancer after screening, and these effects also diminished over time. Individuals with a negative screen had a temporary reduction in perceived risk of cancer. Conclu sions. Individuals who are screened for lung cancer and receive an indeterminate or suspicious screening result have some negative psychological effects from being screened. The results suggest that individuals who are considering screening should be fully informed of the risk of negative psychosocial consequences and that individuals who have been screened should receive clear and detailed information on interpreting screening results.

Participation in Cancer Clinical Trials Why Are Patients Not Participating

Background. Participation in cancer clinical trials is low, particularly in racial and ethnic minorities in some cases, which has negative consequences for the generalizability for study findings. The objective of this study was to determine what factors are associated with patients’ participation or willingness to participate and whether these factors vary by race/ethnicity. Design or Methods. White, Hispanic, and black participants were obtained through the Florida cancer registry and who were diagnosed with breast, lung, colorectal, or prostate cancer (N = 1100). Participants were surveyed via telephone to obtain demographic information, past participation, and willingness to participate in clinical trials, as well as barriers and facilitators to participation. Logistic and Poisson regressions were performed. Results. Respondents were on average 67.4 years old, 42.7% were male, and 50.1% were married. In this population, 7.7% of respondents had participated in a clinical trial, and 36.5% stated that they would be willing to participate. In multivariate models, blacks and Hispanics were equally likely as whites to be willing to participate in cancer trials, but Hispanics were less likely to have participated, and this was especially more likely in non–English-speaking Hispanics compared with English-speaking Hispanics. Notable barriers across race/ethnicity were mistrust and lack of knowledge of clinical trials. Limitations. Cross-sectional design limits cause-and-effect conclusions. Conclusions. There are racial differences in participation rates but not in willingness to participate. We hypothesize that willingness to participate is not very high because people are uninformed about participating, particularly in non–English-speaking Hispanics. Barriers and facilitators to participation vary by race. Improved understanding of cultural differences that can be addressed by physicians may restore faith, comprehension, and acceptability of clinical trials by all patients.

Do racial or socioeconomic disparities exist in lung cancer treatment

Determine the effects of race, socioeconomic status, and treatment on outcomes for patients diagnosed with lung cancer.

Is growth a dirty word? Pollution, abatement and endogenous growth

Abstract Potential conflicts between economic growth and environmental degradation are central to the sustainable development debate. An endogenous growth model is used to investigate tradeoffs between economic growth and environmental quality, where growth is dependent on technology improvements, emissions are generated during final goods production, and physical resources can be used to abate pollution. Pollution growth is higher in a decentralized economy, but technology growth rates can not be ranked between the efficient and equilibrium paths. Even with restricted abatement activity, second-best pollution growth will be below the unregulated level. Zero economic growth policies may increase the rate of environmental degradation.

A positive analysis of financial incentives for cadaveric organ donation.

Financial incentives of various kinds have been suggested to alleviate the chronic shortage of transplantable organs in the United States. This paper analyzes the possible consequences of financial incentives on organ supply. We show that under current practice and current law (which are not the same), inducements to donate organs or to register as an organ donor may lead to a decline in the supply of organs. Furthermore, some financial incentives that have been proposed lead to time inconsistent choices.

Willingness to Pay per Quality-Adjusted Life Year in a Study of Knee Osteoarthritis:

Background. Determining whether a particular medical intervention is cost-effective requires that a threshold of cost per benefit gained be established. As debate continues over the appropriate threshold, we present measures of willingness to pay (WTP) per quality-adjusted life year (QALY) for own health and 2 hypothetical osteoarthritis scenarios. Methods. One hundred ninety-three persons, located through random digit dialing in Harris County, Texas, completed face-to-face interviews collecting demographic information and health preferences using visual analog scale, time tradeoff, standard gamble, and WTP methodologies. Results. The mean WTP/QALY for all methods was lower (range,