N. Cobb | Geology Reports

USGS2011

Breast and cervical cancer screening patterns among American Indian women at IHS clinics in Montana and Wyoming

Objectives. We investigated factors associated with primary and secondary breast and cervical cancer screening among American Indian (AI) women receiving care from the Indian Health Service (IHS) in Montana and Wyoming. Methods. Rates of primary screening (i.e., screening without evidence of a prior abnormal) and secondary screening during a three-year period (2004–2006) were determined in an age- and clinic-stratified random sample of 1,094 women at six IHS units through medical record review. Results. Three-year mammography prevalence rates among AI women aged ≥45 years were 37.7% (95% confidence interval [CI] 34.1, 41.3) for primary and 58.7% (95% CI 43.9, 73.5) for secondary screening. Among women aged ≥18 years, three-year Pap test prevalence rates were 37.8% (95% CI 34.9, 40.6) for primary and 53.2% (95% CI 46.0, 60.4) for secondary screening. Primary mammography screening was positively associated with number of visits and receiving care at an IHS hospital (both p <0.001). Primary Pap test screening was inversely associated with age and positively associated with the number of patient visits (both p <0.001). Secondary mammography screening was inversely associated with driving distance to an IHS facility ( p =0.035). Conclusion. Our results are consistent with other surveys among AI women, which report that Healthy People 2010 goals for breast (90%) and cervical (70%) cancer screening have not been met. Improvements in breast and cervical cancer screening among AI women attending IHS facilities are needed.

Montana, Wyoming↗

USGS2010

A global overview of drought and heat-induced tree mortality reveals emerging climate change risks for forests

Greenhouse gas emissions have significantly altered global climate, and will continue to do so in the future. Increases in the frequency, duration, and/or severity of drought and heat stress associated with climate change could fundamentally alter the composition, structure, and biogeography of forests in many regions. Of particular concern are potential increases in tree mortality associated with climate-induced physiological stress and interactions with other climate-mediated processes such as insect outbreaks and wildfire. Despite this risk, existing projections of tree mortality are based on models that lack functionally realistic mortality mechanisms, and there has been no attempt to track observations of climate-driven tree mortality globally. Here we present the first global assessment of recent tree mortality attributed to drought and heat stress. Although episodic mortality occurs in the absence of climate change, studies compiled here suggest that at least some of the world's forested ecosystems already may be responding to climate change and raise concern that forests may become increasingly vulnerable to higher background tree mortality rates and die-off in response to future warming and drought, even in environments that are not normally considered water-limited. This further suggests risks to ecosystem services, including the loss of sequestered forest carbon and associated atmospheric feedbacks. Our review also identifies key information gaps and scientific uncertainties that currently hinder our ability to predict tree mortality in response to climate change and emphasizes the need for a globally coordinated observation system. Overall, our review reveals the potential for amplified tree mortality due to drought and heat in forests worldwide.

Forest Ecology and Management↗