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Beetle Outbreaks and Wildfires: Drivers of Fire Severity, Recruitment, and Structural Legacies for Sub-boreal Forests in British Columbia
Bark beetle outbreaks have left a legacy of tree mortality across fire-prone landscapes of western North America that could influence how these forests will burn and regenerate. While research has been focused on forests in the western United States, the potential interactions between mountain pine beetle (MPB) outbreaks and wildfires have yet to be investigated in the sub-boreal forests of British Columbia that have pervasive tree mortality.
In this dissertation, I explored the relationships between MPB outbreaks and wildfires through field-based approaches that evaluate the drivers of fire severity, legacy structures, and seedling recruitment, and through satellite-based approaches that evaluated the drivers of burn severity. The majority of this research focused on three fires that burned in 2012, 2013, and 2014 across two provincial parks in central interior British Columbia that are managed as wilderness, are dominated by lodgepole pine (Pinus contorta var. latifolia), and situated at the epicenter of the outbreaks in these sub-boreal forests. I examined the influence of outbreak severity on fire severity using typical first-order fire effects measured in the field as well as legacy structure related to the consumption of woody biomass on snags/trees. I evaluated post-fire seedling recruitment across a gradient of fire severity, including fire refugia - areas only affected by MPB outbreaks and absent of recent fire. I conducted a landscape-scale assessment of MPB outbreak and fire by developing satellite maps of outbreak and fire severity to evaluate the drivers of high burn severity across these landscapes. I supplemented this research with a chemical analysis of pyrogenic carbon on snags from the Pole Creek Fire that burned through lodgepole pine forest with outbreak mortality in the eastern portion of the Cascade Range in Oregon.
In my field study, MPB outbreak severity did not influence fire severity as it related to immediate first-order fire effects, with the exception of a high probability of formation of deep char. Related to this increased formation of deep char, outbreak severity substantially influenced fire severity by affecting postfire legacy structure in these forests. My findings indicate that fire weather and topography are largely influencing fire severity related to first-order fire effects, while biomass consumption related to the architecture of structural legacies that remain post-fire is strongly linked to the status of trees at time of fire (live trees versus deadwood). These results highlight important synergistic effects of outbreak severity and fire severity. Post-fire recruitment density of lodgepole pine was related to fire severity and the abundance of serotinous cones on nearby lodgepole trees, demonstrating that fire is a key mechanism for seed release. Comparison of burned sites to fire refugia with substantial MPB outbreak mortality showed that fire is critical for regeneration of these forests. The landscape-scale assessment based on satellite data indicated that high burn severity was driven predominantly by spatial patterns in fuels and weather, with prefire vegetation conditions having the greatest relative influence on high burn severity overall. The mixture of live and dead fuels associated with post-outbreak landscapes and characterized by remote sensing indices suggested that intermediate levels of outbreak generate a fuel arrangement that supports the greatest probability of high severity fire on these landscapes.
My small field study focused on the chemical characterization of carbon legacies generated by MPB and wildfire showed that the concentration of pyrogenic carbon was higher in samples from charred snags compared to scorched snags. These findings indicate a difference in the carbon legacy that remains on landscapes where fire burns through forests with substantial prefire tree mortality versus those where fire burns through stands dominated by live trees.
Overall, this research provides insights into the disturbance and fire ecology for forests dominated by lodgepole pine with substantial prefire tree mortality from previous, recent disturbance. These forests with pervasive tree mortality burn differently than forests dominated by live trees, leaving an altered legacy structure, but dominant species, lodgepole pine, is generally resilient when MPB outbreaks and wildfire occur in short intervals. This research can inform future research and forest management as it relates to fire severity and forest resilience at the epicenter of the MPB outbreaks
Le competenze infermieristiche avanzate nel trattamento dello stroke in fase acuta in Italia. Strategia per lâidentificazione (I parte)
Introduction: the goal of this study was to describe advanced nursing competences indicators for identification strategy in the stroke care in Italy
and develop a survey tool.
Problem: the new structure of the NHS and the needs expressed by patients increasingly require an advancement of the skills of health professionals.
To this end the authors have identified and described a method for the detection of advanced nursing skills. Starting from the theoretical structure
of AB Hamric have been identified analyzed and compared documents of a professionalizing and clinical from which have identified some
categories. For each indicator have been identified one or more items and has been developed ad hoc questionnaire. At the end this was validated.
Discussion: the methodology for the identification of the indicators has been efficacy in achieving the objectives. The strategy used in the study
is reproducible, since traced to a theoretical model, and contextualized to any clinical setting, where there are secondary sources of evidencebased.
It can also be adapted to post basic training course of a single reality.
Conclusions: advanced clinical knowledge and skills, frequently without a formal recognition because of the complexity and instability of the
patient, are used in the stroke care. ItĂs hoped to use the tool to verify the effectiveness and then play back the path in other clinical setting
Serious maternal complications after early preterm delivery (24-33 weeksâ gestation)
To describe the prevalence of serious maternal complications following early preterm birth by gestational age (GA), delivery route and type of cesarean incision
Preterm neonatal morbidity and mortality by gestational age: a contemporary cohort
Although preterm birth less than 37 weeks gestation is the leading cause of neonatal morbidity and mortality in the United States, the majority of data regarding preterm neonatal outcomes come from older studies, and many reports have been limited to only very preterm neonates. Delineation of neonatal outcomes by delivery gestational age is needed to further clarify the continuum of mortality and morbidity frequencies among preterm neonates
Defining failed induction of labor
BACKGROUND: While there are well-accepted standards for the diagnosis of arrested active-phase labor, the definition of a "failed" induction of labor remains less certain. One approach to diagnosing a failed induction is based on the duration of the latent phase. However, a standard for the minimum duration that the latent phase of a labor induction should continue, absent acute maternal or fetal indications for cesarean delivery, remains lacking.
OBJECTIVE: The objective of this study was to determine the frequency of adverse maternal and perinatal outcomes as a function of the duration of the latent phase among nulliparous women undergoing labor induction.
METHODS: This study is based on data from an obstetric cohort of women delivering at 25 U.S. hospitals from 2008-2011. Nulliparous women who had a term singleton gestation in the cephalic presentation were eligible for this analysis if they underwent a labor induction. Consistent with prior studies, the latent phase was determined to begin once cervical ripening had ended, oxytocin was initiated and rupture of membranes (ROM) had occurred, and was determined to end once 5 cm dilation was achieved. The frequencies of cesarean delivery, as well as of adverse maternal (e.g., cesarean delivery, postpartum hemorrhage, chorioamnionitis) and perinatal outcomes (e.g., a composite frequency of either seizures, sepsis, bone or nerve injury, encephalopathy, or death), were compared as a function of the duration of the latent phase (analyzed with time both as a continuous measure and categorized in 3-hour increments).
RESULTS: A total of 10,677 women were available for analysis. In the vast majority (96.4%) of women, the active phase had been reached by 15 hours. The longer the duration of a woman's latent phase, the greater her chance of ultimately undergoing a cesarean delivery (P<0.001, for time both as a continuous and categorical independent variable), although more than forty percent of women whose latent phase lasted for 18 or more hours still had a vaginal delivery. Several maternal morbidities, such as postpartum hemorrhage (P < 0.001) and chorioamnionitis (P < 0.001), increased in frequency as the length of latent phase increased. Conversely, the frequencies of most adverse perinatal outcomes were statistically stable over time.
CONCLUSION: The large majority of women undergoing labor induction will have entered the active phase by 15 hours after oxytocin has started and rupture of membranes has occurred. Maternal adverse outcomes become statistically more frequent with greater time in the latent phase, although the absolute increase in frequency is relatively small. These data suggest that cesarean delivery should not be undertaken during the latent phase prior to at least 15 hours after oxytocin and rupture of membranes have occurred. The decision to continue labor beyond this point should be individualized, and may take into account factors such as other evidence of labor progress
The association among cytochrome P450 3A, progesterone receptor polymorphisms, plasma 17-alpha hydroxyprogesterone caproate concentrations, and spontaneous preterm birth
Background Infants born <37 weeksâ gestation are of public health concern since complications associated with preterm birth are the leading cause of mortality in children <5 years of age and a major cause of morbidity and lifelong disability. The administration of 17-alpha hydroxyprogesterone caproate reduces preterm birth by 33% in women with history of spontaneous preterm birth. We demonstrated previously that plasma concentrations of 17-alpha hydroxyprogesterone caproate vary widely among pregnant women and that women with 17-alpha hydroxyprogesterone caproate plasma concentrations in the lowest quartile had spontaneous preterm birth rates of 40% vs rates of 25% in those women with higher concentrations. Thus, plasma concentrations are an important factor in determining drug efficacy but the reason 17-alpha hydroxyprogesterone caproate plasma concentrations vary so much is unclear. Predominantly, 17-alpha hydroxyprogesterone caproate is metabolized by CYP3A4 and CYP3A5 enzymes. Objective We sought to: (1) determine the relation between 17-alpha hydroxyprogesterone caproate plasma concentrations and single nucleotide polymorphisms in CYP3A4 and CYP3A5; (2) test the association between progesterone receptor single nucleotide polymorphisms and spontaneous preterm birth; and (3) test whether the association between plasma concentrations of 17-alpha hydroxyprogesterone caproate and spontaneous preterm birth varied by progesterone receptor single nucleotide polymorphisms. Study Design In this secondary analysis, we evaluated genetic polymorphism in 268 pregnant women treated with 17-alpha hydroxyprogesterone caproate, who participated in a placebo-controlled trial to evaluate the benefit of omega-3 supplementation in women with history of spontaneous preterm birth. Trough plasma concentrations of 17-alpha hydroxyprogesterone caproate were measured between 25-28 weeks of gestation after a minimum of 5 injections of 17-alpha hydroxyprogesterone caproate. We extracted DNA from maternal blood samples and genotyped the samples using TaqMan (Applied Biosystems, Foster City, CA) single nucleotide polymorphism genotyping assays for the following single nucleotide polymorphisms: CYP3A4*1B, CYP3A4*1G, CYP3A4*22, and CYP3A5*3; and rs578029, rs471767, rs666553, rs503362, and rs500760 for progesterone receptor. We adjusted for prepregnancy body mass index, race, and treatment group in a multivariable analysis. Differences in the plasma concentrations of 17-alpha hydroxyprogesterone caproate by genotype were evaluated for each CYP single nucleotide polymorphism using general linear models. The association between progesterone receptor single nucleotide polymorphisms and frequency of spontaneous preterm birth was tested using logistic regression. A logistic model also tested interaction between 17-alpha hydroxyprogesterone caproate concentrations with each progesterone receptor single nucleotide polymorphism for the outcome of spontaneous preterm birth. Results The association between CYP single nucleotide polymorphisms *22, *1G, *1B, and *3 and trough plasma concentrations of 17-alpha hydroxyprogesterone caproate was not statistically significant (P =.68,.44,.08, and.44, respectively). In an adjusted logistic regression model, progesterone receptor single nucleotide polymorphisms rs578029, rs471767, rs666553, rs503362, and rs500760 were not associated with the frequency of spontaneous preterm birth (P =.29,.10,.76,.09, and.43, respectively). Low trough plasma concentrations of 17-alpha hydroxyprogesterone caproate were statistically associated with a higher frequency of spontaneous preterm birth (odds ratio, 0.78; 95% confidence ratio, 0.61â0.99; P =.04 for trend across quartiles), however no significant interaction with the progesterone receptor single nucleotide polymorphisms rs578029, rs471767, rs666553, rs503362, and rs500760 was observed (P =.13,.08,.10,.08, and.13, respectively). Conclusion The frequency of recurrent spontaneous preterm birth appears to be associated with trough 17-alpha hydroxyprogesterone caproate plasma concentrations. However, the wide variation in trough 17-alpha hydroxyprogesterone caproate plasma concentrations is not attributable to polymorphisms in CYP3A4 and CYP3A5 genes. Progesterone receptor polymorphisms do not predict efficacy of 17-alpha hydroxyprogesterone caproate. The limitations of this secondary analysis include that we had a relative small sample size (n = 268) and race was self-reported by the patients
Dead forests burning: the influence of beetle outbreaks on fire severity and legacy structure in subâboreal forests
Abstract Recent regional mountain pine beetle (MPB) outbreaks have generated unprecedented tree mortality across the fireâprone landscapes of western North American forests and could potentially modify fire severity and postfire ecological effects. In 2012, 2013, and 2014, three fires burned through high mortality, grayâphase lodgepole pineâdominated forests in the plateau regions of central interior British Columbia, Canada, providing an opportunity to test for interactions between MPB outbreaks and wildfires. We inventoried 63 plots that spanned gradients of outbreak severity, fire severity, and burning conditions in a wilderness setting. Our objective was to evaluate the influence of outbreak severity on fire severity by assessing typical firstâorder fire effects as well as legacy structure related to the consumption of woody biomass on snags/trees. We found no evidence of a relationship between outbreak severity and fire severity for six of seven firstâorder fire effects, with the exception of deep charring. We found evidence that legacy structure in the form of consumed branch structure and deep char development had greater odds of occurrence on MPBâkilled snags compared to trees killed during wildfire. Our results indicate two key findings. First, fire severity as it relates to most firstâorder fire effects measures is not influenced by outbreak severity, instead it is more strongly influenced by the interaction of fuels, weather, and topography during fire events. Second, our results highlight how the interaction between outbreak severity and fire severity alters postfire structural legacies and their functional attributes, which could have important ecosystem implications
Composite Index for Measuring Italian Regionsâ Environmental Quality Over Time
Many socio-economic phenomena have a multidimensional nature and require the definition of a set of individual indicators in order to be properly assessed. The application of a specific statistical technique, called composite index, allows to synthesize the phenomenon making it one-dimensional. One of the main problems in constructing composite indices is the choice of a method that enables to assess changes over time. According to this target, in the paper, we apply a variant of the Mazziotta- Pareto Index (MPI) which allows spatial and time comparisons across units to be made. An application to a set of individual indicators of environmental quality in Italian regions is presented and the reference years are 2006 and 2011. According to the selected indicators, the results show, for a five-year period, an improving trend of environmental quality in all Italian regions