INTERACTIONS AMONG CLIMATE, FIRE, AND ECOSYSTEM PROCESSES ACROSS MULTIPLE SPATIAL AND TEMPORAL SCALES IN ROCKY MOUNTAIN FORESTS

Warmer and drier climate conditions over recent decades are contributing to widespread increases in fire activity across western North America. The combined impacts of changing climate and fire activity threaten to undermine the longstanding resilience of forest ecosystems to wildfires, potentially leading to ecological transformations. This context creates a pressing need to understand the direct effects of climate and wildfire on ecosystem processes, and how longer-term changes in climate, fire activity, and ecosystem processes interact to determine ecological trajectories. This dissertation advances our understanding of the causes and ecosystem consequences of wildfire and changing fire regimes in northern Rocky Mountain forests over years to millennia. In Chapter 1, I utilized extensive field sampling in two recent wildfires in western Montana to document how fires alter microclimatic conditions in biologically meaningful ways for regenerating and surviving vegetation. Through a subsequent study that tracked conifer seedling demography over the first three years following these wildfires, Chapter 2 highlights how spatial heterogeneity in fire effects can facilitate tree regeneration following wildfires, provided suitable post-fire climate. Overall, forests are exhibiting early signs of resilience to these two fire events. Chapters 3 and 4 utilized paleoecological methods to address questions of long-term ecosystem change, and relationships among climate, fire activity, and ecosystem processes. In Chapter 3 I used a high-resolution, multiproxy lake-sediment record from the northern Rockies to reconstruct fire activity and ecosystem change over the past 4800 years. Changes in vegetation and fire activity coincident with increased effective moisture c. 2000 years ago highlight the overarching impact of climate on shaping ecosystem processes. Past wildfires had diverse, detectable impacts on biogeochemical processes, and evidence of ecosystem resilience to wildfires was consistent across variations in climate, vegetation, and fire activity over the late Holocene. Chapter 4 addressed variability in fire activity across a broader landscape, much of it burned during the historic 1910 fire season. I developed a network of 12 lake-sediment records to reconstruct a landscape-scale fire history over the past 2500 years and quantify the historical range of variability. This perspective reveals that contemporary burning, including the 1910 fires, remains within the historical range of fire activity in subalpine forests in this region. My findings imply that northern Rocky Mountain subalpine forests are currently experiencing fire activity and ecological dynamics broadly consistent with historical variability. However, each chapter also highlights the sensitivity of multiple forest ecosystem processes to climate conditions and climate variability. Given the rapid rate of ongoing climatic change, subalpine forests will become increasingly vulnerable to widespread shifts in composition and structure. Future research could focus on identifying thresholds to change and early warning signals

Do antibiotics interfere with the efficacy of oral contraceptives?

Among antibiotics, only rifampin has been demonstrated to interfere with the effectiveness of oral contraceptives (OCs) (strength of recommendation [SOR]: C, limited case series). There is little convincing evidence to show a systematic interaction between other antibiotics and oral contraceptive steroids (SOR: B, based on systematic reviews, case reports, and pharmacologic studies). However, current studies may not have separately evaluated the minority of women whose metabolism of contraceptive steroids makes them more vulnerable to OC failure. Given the significant consequences of unintended pregnancy, some experts recommend a conservative approach, including patient education and backup forms of birth control (SOR: C, expert opinion)

Advancing Arts Education through an Expanded School Day: Lessons from Five Schools

In schools across the country, educators recognize the power of the arts to change young lives. They know that students' sustained engagement with enriching, high-quality experiences in the arts promotes essential skills and perspectives -- like the capacity to solve problems, express ideas, harness and hone creativity, and persevere toward a job well done. And yet today, educators at many schools that operate with conventional schedules are forced to choose between offering their students valuable opportunities to pursue the arts and focusing on other rigorous core classes that also are necessary for success in the 21st century. This study, which highlights an exciting new approach, is produced by the National Center on Time & Learning (NCTL), an organization dedicated to expanding learning time to improve student achievement and enable a well-rounded education, with support from The Wallace Foundation, a national philanthropy seeking to improve education and enrichment for disadvantaged children. In these pages, we present portraits of five schools that are advancing arts education through an expanded school day as they create vibrant and inclusive models of truly enriching education for all students

Does screening for diabetes in at-risk patients improve long-term outcomes?

No randomized clinical trials or prospective studies have demonstrated adequate evidence to screen individuals for diabetes mellitus. A recently published meta-analysis for the United States Preventative Services Task Force (USPSTF) stated that "until we have better evidence about its benefits, harms, and costs, the role of screening as a strategy to reduce the burden of suffering of diabetes will remain uncertain"� (strength of recommendation [SOR]: B, based on inconclusive studies). The group of patients most likely to benefit from diabetes screening are patients with hypertension (SOR: B), or those whose risk for coronary heart disease is such that a diagnosis of diabetes would mandate addition of aspirin or lipid-lowering agents (SOR: C)

Should we use SSRIs to treat adolescents with depression?

Yes. B ased on current evidence, fluoxetine is the most effective selective serotonin reuptake inhibitor (SSRI) for treatment of major depressive disorder in adolescents. It is the only agent approved by the US Food and Drug Administration (FDA) for use in children (strength of recommendation [SOR]: A, based on meta-analysis of RCTs). All SSRI medications increase the risk of suicidal behavior in adolescents, but do not increase the risk of completing suicide (SOR: A, based on meta-analysis of RCTs)

High Frequency of Extra-Pair Paternity in Eastern Kingbirds

Genetic parentage in the socially monogamous and territorial Eastern Kingbird( Tyrannust tyrannus) was examined in a central New York population by multilocus DNA fingerprinting. Extra-pair young were identified in 60% (12 of 20) of nests. Of the 64 nestlings profiled, 42% were sired by extra-pair males, but no cases of conspecific brood parasitism were detected. These results are markedly different from a previous electrophoretic study of the same species in a Michigan population, which reported 39% of nestlings were unrelated to one (typically the mother, quasiparasitismo)r both (conspecificb roodp arasitism) of the putative parents. In the New York population, extra-pairp aternityw as most common among females that returned to breed on a former territory. Among females that were new to a breeding territory, extrapair paternity increased directly with breeding density. Although the power of the tests was low, neither breeding synchrony nor male experience with a breeding territory appeared to be associated with the occurrence of extra-pair young

What predicts a successful smoking cessation attempt?

Quit date abstinence (strength of recommendation [SOR]: B, based on low-quality randomized controlled trial [RCT] of healthy subjects) and refraining from tobacco products within the first 2 weeks after an attempt (SOR: A, based on 2 RCTs) predict long-term abstinence from smoking. Inconsistent studies variously identify being married, a diagnosis of coronary artery disease (CAD) within the past 2 years, a higher education level, advanced age, and social status (such as being a homeowner) as factors correlated with successful smoking cessation (SOR: C, based on prospective cohort studies with conflicting results)

Fluorescence resonance energy transfer sensors for quantitative monitoring of pentose and disaccharide accumulation in bacteria

<p>Abstract</p> <p>Background</p> <p>Engineering microorganisms to improve metabolite flux requires detailed knowledge of the concentrations and flux rates of metabolites and metabolic intermediates <it>in vivo</it>. Fluorescence resonance energy transfer sensors represent a promising technology for measuring metabolite levels and corresponding rate changes in live cells. These sensors have been applied successfully in mammalian and plant cells but potentially could also be used to monitor steady-state levels of metabolites in microorganisms using fluorimetric assays. Sensors for hexose and pentose carbohydrates could help in the development of fermentative microorganisms, for example, for biofuels applications. Arabinose is one of the carbohydrates to be monitored during biofuels production from lignocellulose, while maltose is an important degradation product of starch that is relevant for starch-derived biofuels production.</p> <p>Results</p> <p>An <it>Escherichia coli </it>expression vector compatible with phage λ recombination technology was constructed to facilitate sensor construction and was used to generate a novel fluorescence resonance energy transfer sensor for arabinose. In parallel, a strategy for improving the sensor signal was applied to construct an improved maltose sensor. Both sensors were expressed in the cytosol of <it>E. coli </it>and sugar accumulation was monitored using a simple fluorimetric assay of <it>E. coli </it>cultures in microtiter plates. In the case of both nanosensors, the addition of the respective ligand led to concentration-dependent fluorescence resonance energy transfer responses allowing quantitative analysis of the intracellular sugar levels at given extracellular supply levels as well as accumulation rates.</p> <p>Conclusion</p> <p>The nanosensor destination vector combined with the optimization strategy for sensor responses should help to accelerate the development of metabolite sensors. The new carbohydrate fluorescence resonance energy transfer sensors can be used for <it>in vivo </it>monitoring of sugar levels in prokaryotes, demonstrating the potential of such sensors as reporter tools in the development of metabolically engineered microbial strains or for real-time monitoring of intracellular metabolite during fermentation.</p

The Iowa Homemaker vol.39A, no.3

Halloween-Time for Fanciful Goodies, Rachel Davis, page 5 Checkerboard Summer, Jane Gibson, page 6 Imagination + Independence Encouraged By Honors Program, Carol Shellenbarger, page 8 Honoraries Stress Scholarship, Diane Houser, page 9 Have You Lost Your Marbles?, Carol Armstrong Wolf, page 10 Add a Jibber to Your Wardrobe, Marty Keeney, page 12 Dishpan Hands Soon Obsolete, Beth Beecher, page 13 Key to Personality – Your Walk, Suzanne Guernsey, page 14 How Do You Rate With Your Professor?, Mary Stoner, page 15 What’s Going On, page 1