Search

Background: Foliar moisture content influences crown fire ignition and behaviour. Some spatial variation in foliar moisture is attributable to differences in stand conditions but evidence describing this role is lacking or contradicting. Aims: To examine the role of stand conditions on tree physiology and foliar moisture content in Oregon white oak (Quercus garryana) and Douglas-fir (Pseudotsuga menziesii). Methods: We monitored foliar moisture content in both species, and tree physiology (stomatal conductance and leaf water potential) in oak, across three stand conditions, including intact stands (unencroached), stands invaded by Douglas-fir (encroached), and thinned stands with Douglas-fir removed. Key results: Encroached stands had higher foliar moisture content than intact or thinned stands. Higher stand density was associated with higher foliar moisture content in both species and foliage ages. Encroached stands also had higher midday leaf water potential compared with intact or thinned stands. Conclusions: These findings provide strong evidence that stand conditions and thinning treatments can influence foliar moisture content in Oregon white oak ecosystems, with likely implications for other ecosystems. Implications: Better understanding of the role of stand conditions on foliar moisture content may contribute to improved spatial and temporal prediction of foliar moisture content and modelling of potential crown fire behaviour. Stand conditions within a fire-excluded Oregon white oak ecosystem affected foliar moisture content. Encroached stands consistently had higher foliar moisture content, and were associated with stand density and leaf water potential. Better understanding of the role of stand conditions may contribute to improved modelling of potential crown fire behaviour. [ABSTRACT FROM AUTHOR]

Premise: Ecogeographic isolation, or geographic isolation caused by ecological divergence, is thought to be of primary importance in speciation, yet is difficult to demonstrate and quantify. To determine whether distributions are limited by divergent adaptation or historical contingency, the gold standard is to reciprocally transplant species between their geographic ranges. Alternatively, ecogeographic isolation is inferred from species distribution models and niche divergence tests using widely available environmental and occurrence data. Methods: We tested for ecogeographic isolation between two sister species of California annual wildflowers, Clarkia concinna and C. breweri, with a hybrid approach. We used niche models to predict water availability as the major axis of ecological divergence and then tested that with a greenhouse experiment. Specifically, we manipulated water availability in field soils for two populations of each species and predicted higher fitness in conditions representing home habitats to those representing the environment of each's sister species. Results: Water availability and soil representing C. concinna generally increased both species' fitness. Thus, water and soil may indeed limit C. concinna from colonizing the range of C. breweri, but not vice versa. We suggest that the competitive environment and pollinator availability, which are not directly captured with either approach, may be key biotic factors correlated with climate that contribute to unexplained ecogeographic isolation for C. breweri. Conclusions: Ours is a valuable approach to assessing ecogeographic isolation, in that it balances feasibility with model validation, and our results have implications for species distribution modeling efforts geared toward predicting climate change responses. [ABSTRACT FROM AUTHOR]

Abstract: Aims: We investigated the association between cumulative lifetime and current marijuana use with total abdominal adipose tissue (AT), visceral AT, subcutaneous AT, intermuscular AT, and mean liver attenuation (LA) at mid‐life. Design: Longitudinal and cross‐sectional secondary data analysis of participants in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Setting: CARDIA field centers in Birmingham, AL; Chicago, IL; Minneapolis, MN; and Oakland, CA, USA. Participants: CARDIA participants, aged 18–30 years in 1985–1986, who were present at the clinic examination in 2010–2011 (n = 2902). Measurements: Marijuana use was assessed from responses to self‐administered questionnaires at 8 CARDIA examinations over 25 years, determined as cumulative marijuana‐years and current use status. Non‐contrast computed tomography imaging of the abdomen was obtained in 2010–2011. Findings: In 2010–2011, 84% of participants reported a history of marijuana use with 11% reporting use within the past 30 days. Before adjustment, we observed greater cumulative marijuana use was associated with lower total abdominal and subcutaneous AT volume and lower LA and current marijuana use was associated with lower subcutaneous AT. However, after adjustment for age, sex, race, field center, cigarette pack‐years and current use, regular alcohol consumption, cumulative drink‐years, and physical activity, neither cumulative marijuana use nor current use showed an association with any abdominal adipose depot. Our estimates did not differ by age, sex, or race nor after accounting for cohort attrition. Conclusion: Neither cumulative marijuana use nor current marijuana use is associated with total abdominal, visceral, subcutaneous, or intermuscular adipose tissue, or liver attenuation in mid‐life. [ABSTRACT FROM AUTHOR]

In this article the author discusses the 2007 Academy Awards ceremony held at the Kodak Theatre in Hollywood, California. He argues that the presence of Al Gore during the event appeared to confirm the doubt of many conservative Americans that there is a close collaboration between Hollywood and the Democratic Party. Moreover, the queen and king of comedy television (TV) programs, the promotional role of Hollywood stars, and the trend of children films are also discussed.

One thousand consecutive intakes at an outpatient psychiatric clinic were screened for past suicide attempts and present suicidal ideation and diagnosed using DSM-III-R criteria. A full range of thoughts about death and suicide were prevalent in all diagnostic groups. Over one-third of patients with major depression and borderline personality disorder had actual plans to kill themselves, and over two-thirds of patients with borderline personality disorder had made one or more suicide attempts.