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Seasons in the Stream: River Ecosystem Phenology in a Changing Climate
No full textPatterns of primary productivity are primarily dictated by seasonal factors like light availability and temperature. In small rivers, primary productivity often peaks opposite that of terrestrial ecosystems, where overhanging canopies shade the river channel impeding light reaching the water surface. The degree to which river primary productivity is affected by the surrounding terrestrial environment depends on the river size. As rivers widen, river primary productivity increases, with more light reaching the stream channel. While light availability may set up the “window of metabolic opportunity” for river primary producers, factors like flow disturbance and grazing pressure from invertebrates can constrain the overall magnitude of gross primary productivity, or GPP. My dissertation seeks to evaluate what processes control the pattern and magnitude of primary productivity in rivers. I evaluate this driving question by analyzing the efficiency by which river ecosystems convert light energy into autotrophic biomass across 64 rivers (Chapter 2), through a series of in-depth experiments and careful monitoring of algae in a small forested river (Chapter 3), and in evaluating whether ice cover determines patterns of primary productivity along a river continuum (Chapter 4). Finally, I provide a framework for evaluating how climate change may be impacting the patterns of primary productivity in rivers (Chapter 5). In Chapter 2, we found that rivers are extremely efficient at converting light energy to biomass (i.e. have a high ecosystem light use efficiency, LUE). The range of LUEs reported in our study encompasses the entire range for any ecosystem LUE measured in forests, crops, lakes, and previous river studies. While river ecosystems have the potential to have high LUE on their “best days,” variability of flow constrains LUE throughout the year. In Chapter 3, we found that algae in the oligotrophic and steep headwaters of Hubbard Brook Experimental Forest were both more abundant than past studies and preferentially grew within substrates that simulate the physical structure of bryophytes. Throughout four separate nutrient diffusing substrate deployments, we found that nutrients rarely limited algal biomass. This chapter explores the previously unsuspected role of bryophytes in providing refugia for algae in this high-gradient and nutrient-poor stream. In Chapter 4, we combined three metrics of ice cover (satellite-, field camera-, and temperature-based) with a proxy for primary productivity across a river continuum. We found that satellite and field camera-based ice cover records reveal two important aspects of ice dynamics in a 3rd to 6th Strahler order river. First, river ice in narrow channels is dynamic, with more complete ice cover days and mid-winter breakups happening on the narrowest section of the reach. Second, ice cover is habitat-specific, with riffle sequences along the river never reaching complete ice cover. In comparing ice dynamics to a proxy of GPP, diel dissolved oxygen amplitude, we found that ice on rivers not only affects the overall pattern of primary productivity, but also affects our ability to measure primary productivity by affecting river gas exchange. Finally, in Chapter 5, I provide examples of relevant drivers of change for river ecosystem GPP in a warming climate. More studies that attempt to disentangle how climate change is affecting light availability, nutrients, temperature, ice cover, etc., or how climate change is shifting the “windows of metabolic opportunity” for rivers, will be imperative in the Anthropocene. </p
Evaluation of the association between maternal smoking, childhood obesity, and metabolic disorders: a national toxicology program workshop review.
No full textBackgroundAn emerging literature suggests that environmental chemicals may play a role in the development of childhood obesity and metabolic disorders, especially when exposure occurs early in life.ObjectiveHere we assess the association between these health outcomes and exposure to maternal smoking during pregnancy as part of a broader effort to develop a research agenda to better understand the role of environmental chemicals as potential risk factors for obesity and metabolic disorders.MethodsPubMed was searched up to 8 March 2012 for epidemiological and experimental animal studies related to maternal smoking or nicotine exposure during pregnancy and childhood obesity or metabolic disorders at any age. A total of 101 studies-83 in humans and 18 in animals-were identified as the primary literature.DiscussionCurrent epidemiological data support a positive association between maternal smoking and increased risk of obesity or overweight in offspring. The data strongly suggest a causal relation, although the possibility that the association is attributable to unmeasured residual confounding cannot be completely ruled out. This conclusion is supported by findings from laboratory animals exposed to nicotine during development. The existing literature on human exposures does not support an association between maternal smoking during pregnancy and type 1 diabetes in offspring. Too few human studies have assessed outcomes related to type 2 diabetes or metabolic syndrome to reach conclusions based on patterns of findings. There may be a number of mechanistic pathways important for the development of aberrant metabolic outcomes following perinatal exposure to cigarette smoke, which remain largely unexplored.ConclusionsFrom a toxicological perspective, the linkages between maternal smoking during pregnancy and childhood overweight/obesity provide proof-of-concept of how early-life exposure to an environmental toxicant can be a risk factor for childhood obesity
Use of Preservation in North Carolina Wetland and Stream Mitigation
No full textTo better protect the nation’s wetlands and streams, the Clean Water Act allows use of compensatory mitigation to replace the benefits of lost wetlands and streams. This study summarizes North Carolina’s use of preservation for compensatory mitigation by private mitigation banks and a state-operated in-lieu fee (ILF) program. Within private mitigation banks, preservation activities have generated 5.6% of wetland credits and 9.1% of stream credits since 2008. Within the state in-lieu fee program run by the Division of Mitigation Services, 45.0% of wetland credits and 6.2% of stream credits have resulted from preservation. However, a majority of the wetland credits generated by preservation in the ILF program came from one site described as unusually large by program staff. Since 2008, North Carolina’s ILF program and mitigation banks have continued to use preservation at relatively low rates for both wetland and stream mitigation. Mitigation providers have stated that the clarity of the state’s preservation policy makes it easier for preservation to be included in projects in North Carolina than in projects in some other states. Notably, between 2012 and 2015, no wetland preservation was used for mitigation by the ILF program
The Quiet Company
No full texthttp://www.amazon.com/Tomorrow-Karen-Henderson/dp/0987565702/ref=sr_1_2?s=books&ie=UTF8&qid=1372543812&sr=1-
166 Predictive Modeling of Length of Hospital Stay Following Adult Spinal Deformity Correction: Analysis of 653 Patients With an Accuracy of 75% Within 2 Days
No full textINTRODUCTION: The length of stay (LOS) following adult spinal deformity (ASD) surgery is a critical time period allowing for recovery to levels safe enough to return home or to rehabilitation. Thus, the goal is to minimize it for conserving hospital resources and third-party payer pressure. Factors related to LOS have not been studied nor has a predictive model been created. The goal of this study was to construct a preadmission predictive model based on patients' baseline variables and modifiable surgical parameters
Governing a Boomburb: Guiding Cary's Growth Into The Future
No full textWhat lessons can Cary draw on from Boomburbs around the country to best navigate the governance challenges associated with this form of municipality?
Boomburbs are municipalities which have a population of more than 100,000 people and which have grown at a double-digit rate for multiple decades yet remain only the second largest community in their metropolitan area. This report explores the above policy question by highlighting common demographic and governance characteristics of Boomburbs and identifying how Cary aligns with these descriptors. It then utilizes a qualitative research methodology informed by interviews with Boomburb council members and city managers to gather insights on Cary and four other comparable Boomburbs from across the country.
This research revealed several common themes between Cary and its peer Boomburbs. Decisions from state legislatures altered political influences in elections within all communities. Several municipalities had well-tenured council bodies guiding their growth and success. Strategic planning and mechanisms to increase citizen engagement in government were common across Boomburbs. Cary stood apart from its fellow Boomburbs, however, by maintaining its identity as a “town” despite its leading growth rate. Cary included more partisan identifiers for current council members in online town materials than other case study locations. The town had the most tenured
yet lowest paid town or city council of all five Boomburbs.
Promoting pathways to leadership spanning from Cary’s citizen academy to the town council would increase the likelihood that new leaders are prepared to continue on Cary’s current level of excellence and foster greater and more diverse community engagement at higher levels of local government. Combining these pathways with strategies to expand professional development opportunities for government staff and utilize strategic management to establish a unified vision across the town would further fuel Cary’s future success as a Boomburb
Queer Muslim Environmental Futurisms: Taqwa (Introspection) and Barzakh (Liminality and Paradox)
No full textThrough Orientalism, EuroAmerican hegemony constructs nature and sexuality to control ideas and resources around Muslims and nonhumans. EuroAmerican colonizers introduced to Islamic theology the very association of sexuality with “natural/unnatural.” As a result, claims by numerous Islamic scholars that homosexuality is forbidden in Islam because it is “unnatural” echo Orientalist constructions of nature and sexuality.
This thesis draws from intersectional queer Muslim perspectives to question Orientalist constructions of nature. I examine academic literature, artistic mediums, and political realities to theorize Queer Muslim Environmental Futurisms (QMEF). Reckoning with the “paradox” of their identities, queer Muslims offer non-linear temporalities that reject Orientalist binaries between humans and nature, queerness and Muslimness. Dismantling Orientalist binaries, I argue that Queer Muslim Environmental Futurisms (QMEF) instead embrace the barzakh (liminality and paradox) of queer/Muslim and human/nature relationships.
I first outline a QMEF to facilitate dialogue between queer and Muslim environmental literature over different points of time. I then analyze Saba Taj’s there are gardens at the margins, a mixed-media visual arts exhibition highlighting queer Muslim relationships, to demonstrate how barzakh can negotiate new temporalities and relationships for queer Muslims and nonhumans. I also examine moments of QMEF during the Gezi Park Protests in Turkey, which show queer-Muslim coalition and blips of breakage in linear time. In these examples, I unpack how queer Muslims embrace contradictions, bringing opposites together as a whole. This thesis thus demonstrates how QMEF heals separations between queerness and Muslimness, human and nonhuman creatio
Comparative Assessment of the Absorbed Doses Resulted from Occupational Exposure and Computed Tomography
No full textA comparative assessment of the absorbed doses resulted from computed tomography (CT) examinations, and the dose resulted from occupational external gamma exposure of the “Mayak” workers was carried out. The patients’ diagnostic radiation dose was reconstructed using Monte-Carlo simulation on a population of 58 virtual adult phantoms across 13 CT protocol categories. Archival records of CT examinations of patients were used for the dose reconstruction. Information on technical parameters of scanning was extracted from DICOM files. The study sample has been linked to the Mayak worker register database to identify persons who had professional contact with ionizing radiation. Annual occupational dose records for the Mayak workers were obtained from the Dose-2013 dosimetry system. In this study, information on 212 patients was collected from 303 records. Among them, 42 Mayak employees were identified, including 24 persons who had non-zero dose of external gamma radiation, and 16 persons with internal alpha radiation dose due to occupational intake of 239Pu. Individual doses absorbed in the organs resulted from exposure to computed tomography and occupational activities has been compared. The results showed significant variability of the absorbed organ dose depending on the area of CT examination. The brain and lens were subjected to the highest radiation exposure during head CT. The average absorbed dose in brain was 24.5 mGy per single examination (the maximum brain dose accumulated over the entire study period was 82.3 mGy), and 27.7 mGy for the lens of the eye (the maximum lens dose reached 92.9 mGy). Relevant comparison of the absorbed dose of diagnostic and occupational exposure, accumulated during one year, has been performed. The average estimate of cumulative radiation dose absorbed in the organs during computed tomography was an order of magnitude lower than the one from occupational external gamma exposure of Mayak personnel, except brain dose. Annual CT dose equivalent of external gamma radiation was 2.82.</jats:p
Absolute Continuity of Singular SPDEs and Bayesian Inference on Dynamical Systems
No full textWe explore the interplay among probability, stochastic analysis, and dynamical systems through two lenses: (1) absolute continuity of singular stochastic partial differential equations (SPDEs); (2) Bayesian inference on dynamical systems.In the first part, we prove that up to a certain singular regime, the law of the stochastic Burgers equation at a fixed time is absolutely continuous with respect to the corresponding stochastic heat equation with the nonlinearity removed. The results follow from an extension of the Girsanov Theorem to handle less spatially regular solutions while only proving absolute continuity at a fixed time. To deal with the singularity, we introduce a novel decomposition in the spirit of Da Prato-Debussche and Gaussian chaos decomposition in singular SPDEs, by separating out the noise into different levels of regularity, along with a number of renormalization techniques. The number of levels in this decomposition diverges to infinite as we move to the stochastic Burgers equation associated with the KPZ equation. This result illustrates the fundamental probabilistic structure of a class of singular SPDEs and a notion of ``ellipticity'' in the infinite-dimensional setting. In the second part, we establish connections between large deviations and a class of generalized Bayesian inference procedures on dynamical systems. We show that posterior consistency can be derived using a combination of classical large deviation techniques, such as Varadhan's lemma, conditional/quenched large deviations, annealed large deviations, and exponential approximations. We identified the divergence term as the Donsker-Varadhan relative entropy rate, also related to the Kolmogorov-Sinai entropy in ergodic theory. As an application, we prove new quenched/annealed large deviation asymptotics and a new Bayesian posterior consistency result for a class of mixing stochastic processes. In the case of Markov processes, one can obtain explicit conditions for posterior consistency, when estimates for log-Sobolev constants are available, which makes our framework essentially a black box. We also recover state-of-the-art posterior consistency on classical dynamical systems with a simple proof. Our approach has the potential of proving posterior consistency for a wide range of Bayesian procedures in a unified way.</p
Annotation of phenotypes using ontologies: a gold standard for the training and evaluation of natural language processing systems.
No full textNatural language descriptions of organismal phenotypes, a principal object of study in biology, are abundant in the biological literature. Expressing these phenotypes as logical statements using ontologies would enable large-scale analysis on phenotypic information from diverse systems. However, considerable human effort is required to make these phenotype descriptions amenable to machine reasoning. Natural language processing tools have been developed to facilitate this task, and the training and evaluation of these tools depend on the availability of high quality, manually annotated gold standard data sets. We describe the development of an expert-curated gold standard data set of annotated phenotypes for evolutionary biology. The gold standard was developed for the curation of complex comparative phenotypes for the Phenoscape project. It was created by consensus among three curators and consists of entity-quality expressions of varying complexity. We use the gold standard to evaluate annotations created by human curators and those generated by the Semantic CharaParser tool. Using four annotation accuracy metrics that can account for any level of relationship between terms from two phenotype annotations, we found that machine-human consistency, or similarity, was significantly lower than inter-curator (human-human) consistency. Surprisingly, allowing curatorsaccess to external information did not significantly increase the similarity of their annotations to the gold standard or have a significant effect on inter-curator consistency. We found that the similarity of machine annotations to the gold standard increased after new relevant ontology terms had been added. Evaluation by the original authors of the character descriptions indicated that the gold standard annotations came closer to representing their intended meaning than did either the curator or machine annotations. These findings point toward ways to better design software to augment human curators and the use of the gold standard corpus will allow training and assessment of new tools to improve phenotype annotation accuracy at scale