Effects of fire rotation interval and overstory type on ambient soil temperatures in ponderosa pine forests in Arizona

Ambient soil temperatures were measured every four weeks from May 1986 to November 1986 at three depths under the organic forest floor in ponderosa pine (Pinus ponderosa Lawson & C. Lawson) forests in three stand types subjected to periodic prescribed burning. Temperatures at the organic layer – soil surface interface in sawtimber stands were higher and more variable than in pole and saplings stands. Temperature variability reached a maximum in the summer and decreased into the fall and early winter. Soil temperature variability decreased as depth below the surface increased. Three years after the low-intensity prescribed burns, soil temperatures in the burned stands were not significantly different from the those in the unburned controls, suggesting that any effect, though none was detected, of the low-intensity prescribed burns on soil temperature and belowground processes affected by temperature is short-lived in these stands.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Prescribed Fire Impacts on Soil Carbon and Nitrogen

From the Proceedings of the 2002 Meetings of the Hydrology Section - Arizona-Nevada Academy of Science - April 6, 2002, Midwestern University, Glendale, ArizonaThis article is part of the Hydrology and Water Resources in Arizona and the Southwest collections. Digital access to this material is made possible by the Arizona-Nevada Academy of Science and the University of Arizona Libraries. For more information about items in this collection, contact [email protected]

Interplay between whole-genome doubling and the accumulation of deleterious alterations in cancer evolution

Whole-genome doubling (WGD) is a prevalent event in cancer, involving a doubling of the entire chromosome complement. However, despite its prevalence and prognostic relevance, the evolutionary selection pressures for WGD in cancer have not been investigated. Here, we combine evolutionary simulations with an analysis of cancer sequencing data to explore WGD during cancer evolution. Simulations suggest that WGD can be selected to mitigate the irreversible, ratchet-like, accumulation of deleterious somatic alterations, provided that they occur at a sufficiently high rate. Consistent with this, we observe an enrichment for WGD in tumor types with extensive loss of heterozygosity, including lung squamous cell carcinoma and triple-negative breast cancers, and we find evidence for negative selection against homozygous loss of essential genes before, but not after, WGD. Finally, we demonstrate that loss of heterozygosity and temporal dissection of mutations can be exploited to identify novel tumor suppressor genes and to obtain a deeper characterization of known cancer genes

Wildland Fire in Ecosystems Effects of Fire on Flora

This state-of-knowledge review about the effects of fire on flora and fuels can assist land managers with ecosystem and fire management planning and in their efforts to inform others about the ecological role of fire. Chapter topics include fire regime classification, autecological effects of fire, fire regime characteristics and postfire plant community developments in ecosystems throughout the United States and Canada, global climate change, ecological principles of fire regimes, and practical considerations for managing fire in an ecosytem context

Factors associated with pregnancy attempts among female young adult cancer survivors

PURPOSE: Little is known about pregnancy attempts among female young cancer survivors (YCS). We sought to determine fertility preservation (FP), demographic, cancer and reproductive characteristics associated with pregnancy attempts after cancer. METHODS: We recruited 251 female YCS (ages 18-44) to complete a survey on reproductive health outcomes. We used log-binomial regression models to estimate relative risks (RR) for characteristics associated with pregnancy attempts. RESULTS: For the entire cohort, median time since cancer diagnosis was 2.4 years (interquartile range 4.0). Fifty-two YCS (21%) attempted pregnancy after cancer diagnosis. In unadjusted analyses, lack of FP therapy prior to cancer treatment, older age, partnered relationship, higher income, history of stem cell or bone marrow transplant, and longer duration of survivorship were significantly associated with pregnancy attempts. In multivariable analyses, YCS who did not undergo FP therapy were more than twice as likely to attempt pregnancy as those who did undergo FP therapy (RR 2.4, 95%CI 1.3, 4.3). Partnered status (RR 7.1, 95%CI 2.5, 20.2) and >2 years since cancer diagnosis (RR 2.3, 95%CI 1.3, 4.1) were also significantly associated with attempts. CONCLUSIONS: In YCS, milestones including partnered relationships and longer duration of cancer survivorship are important to attempting pregnancy. A novel, inverse association between FP therapy and pregnancy attempts warrants further study. IMPLICATIONS FOR CANCER SURVIVORS: Pregnancy attempts after cancer were more likely after attaining both social and cancer-related milestones. As these milestones require time, YCS should be made aware of their potential for concomitant, premature loss of fertility in order to preserve their range of fertility options