Post(al) Apocalypse: A Letter About Virginia Woolf\u27s Fictional Letters

I set out to write about eating distress in Virginia Woolf. I wanted to write about mothers, too, in her fiction and essays, because, as Chris Kraus puts it, “Mother is Food.” I began by investigating one of Woolf’s fictional letters, written in Jacob’s Room. There, the letter arrives at breakfast. This coincidence followed me into my other readings on mothering and food, so I decided to discuss Woolf’s fictional epistolary form for an entire chapter. And then, after winter break, an entire chapter became an entire thesis

CLIMATIC AND BIOTIC INTERACTIONS IN TERRESTRIAL SYSTEMS DURING ANCIENT WARM PERIODS

This work focuses on two terrestrial sedimentary records in the western United States that record the ancient greenhouse interval of the early Paleogene (~ 55 million years ago). The Paleogene, and past warm periods in general, offer a means of understanding potential biotic and environmental response to future warming scenarios. Part One of this dissertation establishes a new stable isotope climate record from the Bighorn Basin of Wyoming that is tied to an extensive fossil mammal assemblage (Chapter 1). This new stable isotope record captures carbon isotope excursions (CIEs) associated with the early Eocene hyperthermals ETM2, H2, and potentially I1 and provides the first record of these hyperthermals from the fossil-rich Fifteenmile Creek area of the south-central Bighorn Basin. Previously identified pulses in mammal turnover and diversity in this area are linked with these global warming events for the first time. These results also highlight spatial variability in the magnitude of these CIEs, with the Fifteenmile Creek area recording smaller-magnitude CIEs than more northerly records in the same basin. Part Two of this dissertation focuses on the Sheep Pass Formation in eastern Nevada. Sheep Pass Formation sediments record an ancient high-elevation lake and fluvial system that provides insight into how high-elevation settings responded to warming in the past. The age of the Sheep Pass Formation remains poorly resolved so rock magnetic, paleomagnetic, and additional geochronological data were collected to develop a better-resolved chronostratigraphy and to further understand how freshwater carbonates acquire a remanent magnetization. Rock magnetic results (Chapter 2) indicate that the Sheep Pass Formation preserves a heterogeneous assemblage of magnetic minerals, including primary and secondary phases. Many samples indicate the presence of goethite and/or maghemite that likely form as alteration products, in addition to a (titano)magnetite remanence carrier likely associated with deposition. New paleomagnetic and detrital zircon U-Pb age constraints on the Sheep Pass Formation (Chapter 3) allow its developing geochemical and sedimentological records to be correlated to the geologic timescale. These data support previous age estimates and place the formation within the Late Cretaceous to middle Eocene interval. The paleomagnetic record from the Sheep Pass Formation records two magnetic polarities, though these directions are influenced by a magnetic overprint producing a noticeable eastern directional bias in the record. Detrital zircon analyses from Member C in the Sheep Pass Formation produce a population of ~62 Ma grains, providing a new maximum depositional age for that part of the formation. The preferred age model based on all the relevant chronostratigraphic constraints suggests that the Sheep Pass Formation ranges from ~ 72 Ma to ~49 Ma with Member B limited to the latest Cretaceous to mid-late Paleocene. Member E is correlated to the nearby Bridgerian Elderberry Quarry Local Fauna (~47.5 – 52 Ma, early-middle Eocene) and correlates to either Chron C22n (~49 Ma) or C23n (~51 Ma). Together, this correlation suggests that the K-Pg boundary would likely have occurred in Member B, early Eocene hyperthermals might be recorded in Member C, and the Early Eocene Climate Optimum (EECO) could be recorded in Member E

The role of tropical-extratropical interaction and synoptic variability in maintaining the South Pacific Convergence Zone in CMIP5 models

The South Pacific Convergence Zone (SPCZ) is simulated as too zonal a feature in current generation climate models, including those in Phase 5 of the Coupled Model Intercomparison Project (CMIP5). This zonal bias induces errors in tropical convective heating, with subsequent effects on global circulation. The SPCZ structure, particularly in the subtropics, is governed by the tropical-extratropical interaction between transient synoptic systems and the mean background state. However, the fidelity of synoptic-scale interactions as simulated by CMIP5 models has not yet been evaluated. In this study, analysis of synoptic variability in the simulated subtropical SPCZ reveals that the basic mechanism of tropical-extratropical interaction is generally well simulated, with storms approaching the SPCZ along comparable trajectories to observations. However, there is a broad spread in mean precipitation and its variability across the CMIP5 ensemble. Inter-model spread appears to relate to a biased background state in which the synoptic waves propagate. In particular, the region of mean negative zonal stretching deformation or "storm graveyard" in the upper troposphere?a feature previously determined to play a key role in SPCZ-storm interactions?is typically displaced in CMIP5 models to the northeast of its position in reanalysis data, albeit with individual model graveyards displaying a pronounced (25 degree) longitudinal spread. From these findings, we suggest that SPCZs simulated by CMIP5 models are not simply too zonal; rather, in models the subtropical SPCZ manifests a diagonal tilt similar to observations while SST biases force an overly zonal tropical SPCZ, resulting in a more disjointed SPCZ than observed

Redox stress defines the small artery vasculopathy of hypertension: how do we bridge the bench-to-bedside gap?

Although convincing experimental evidence demonstrates the importance of vascular reactive oxygen and nitrogen species (RONS), oxidative stress, and perturbed redox signaling as causative processes in the vasculopathy of hypertension, this has not translated to the clinic. We discuss this bench-to-bedside disparity and the urgency to progress vascular redox pathobiology from experimental models to patients by studying disease-relevant human tissues. It is only through such approaches that the unambiguous role of vascular redox stress will be defined so that mechanism-based therapies in a personalized and precise manner can be developed to prevent, slow, or reverse progression of small-vessel disorders and consequent hypertension

Folic Acid Supplementation Improves Vascular Function in Professional Dancers With Endothelial Dysfunction

Objective To determine if folic acid supplementation improves vascular function (brachial artery flow-mediated dilation [FMD]) in professional dancers with known endothelial dysfunction. Design Prospective cross-sectional study. Setting Academic institution in the Midwestern United States. Subjects Twenty-two professional ballet dancers volunteered for this study. Main Outcome Measures Subjects completed a 3-day food record to determine caloric and micronutrient intake. Menstrual status was determined by interview and questionnaire. Endothelial function was determined as flow-induced vasodilation measured by high-frequency ultrasound of the brachial artery. A change in brachial diameter of Results Sixty-four percent of dancers (n = 14) had abnormal brachial artery FMD (P\u3c .0001). Conclusions This study reveals that vascular endothelial function improves in dancers after supplementation with folic acid (10 mg/day) for at least 4 weeks. This finding may have clinically important implications for future cardiovascular disease risk prevention

Association Between the Female Athlete Triad and Endothelial Dysfunction in Dancers

Objective: To determine the prevalence of the 3 components of the female athlete triad [disordered eating, menstrual dysfunction, low bone mineral density (BMD)] and their relationships with brachial artery flow-mediated dilation in professional dancers. Design: Prospective study. Setting: Academic institution in the Midwest. Participants: Twenty-two professional ballet dancers volunteered for this study. Interventions: The prevalence of the female athlete triad and its relationship to endothelial dysfunction. Main Outcome Measures: Subjects completed questionnaires to assess disordered eating and menstrual status/history. They also completed a 3-day food record and wore an accelerometer for 3 days to determine energy availability. Serum baseline thyrotropin, prolactin, and hormonal concentrations were obtained. Bone mineral density and body composition were measured with a GE Lunar Prodigy dual-energy X-ray absorptiometry. Endothelial function was determined as flow-mediated vasodilation measured by high-frequency ultrasound in the brachial artery. An increase in brachial diameter Results: Seventeen dancers (77%) had evidence of low/negative energy availability. Thirty-two percent had disordered eating (EDE-Q score). Thirty-six percent had menstrual dysfunction and 14% were currently using hormone contraception. Twenty-three percent had evidence of low bone density (Z-score \u3c -1.0). Sixty-four percent had abnormal brachial artery flow-mediated dilation ( Conclusions: Endothelial dysfunction was correlated with reduced BMD, menstrual dysfunction, and low serum estrogen. These findings may have profound implications for cardiovascular and bone health in professional women dancers

Terrestrial carbon isotope stratigraphy and mammal turnover during post-PETM hyperthermals in the Bighorn Basin, Wyoming, USA

Paleogene hyperthermals, including the Paleocene–Eocene Thermal Maximum (PETM) and several other smaller events, represent global perturbations to Earth’s climate system and are characterized by warmer temperatures, changes in floral and faunal communities, and hydrologic changes. These events are identified in the geologic record globally by negative carbon isotope excursions (CIEs), resulting from the input of isotopically light carbon into Earth’s atmosphere. Much about the causes and effects of hyperthermals remains uncertain, including whether all hyperthermals were caused by the same underlying processes, how biotic effects scale with the magnitude of hyperthermals, and why CIEs are larger in paleosol carbonates relative to marine records. Resolving these questions is crucial for a full understanding of the causes of hyperthermals and their application to future climate scenarios. The primary purpose of this study was to identify early Eocene hyperthermals in the Fifteenmile Creek area of the south-central Bighorn Basin, Wyoming, USA. This area preserves a sequence of fluvial floodplain sedimentary rocks containing paleosol carbonates and an extensive record of fossil mammals. Previous analysis of faunal assemblages in this area revealed two pulses of mammal turnover and changes in diversity interpreted to correlate with the ETM2 and H2 hyperthermals that follow the PETM. This was, however, based on long-distance correlation of the fossil record in this area with chemostratigraphic records from elsewhere in the basin. We present new carbon isotope stratigraphies using micrite δ13C values from paleosol carbonate nodules preserved in and between richly fossiliferous mammal localities at Fifteenmile Creek to identify the stratigraphic positions of ETM2 and H2. Carbon isotope results show that the ETM2 and H2 hyperthermals, and possibly the subsequent I1 hyperthermal, are recorded at Fifteenmile Creek. ETM2 and H2 overlap with the two previously recognized pulses of mammal turnover. The CIEs for these hyperthermals are also somewhat smaller in magnitude than in more northerly Bighorn Basin records. We suggest that basin-wide differences in soil moisture and/or vegetation could contribute to variable CIE amplitudes in this and other terrestrial records

Tropical cyclone projections: changing climate threats for Pacific island defense installations

Potential changing climate threats in the tropical and subtropical North Pacific Ocean were assessed, using coupled ocean-atmosphere and atmosphere-only general circulation models, to explore their response to projected increasing greenhouse gas emissions. Tropical cyclone occurrence, described by frequency and intensity, near islands housing major U.S. defense installations was the primary focus. Four island regions-Guam and Kwajalein Atoll in the tropical northwestern Pacific, Okinawa in the subtropical northwestern Pacific, and Oahu in the tropical north-central Pacific-were considered, as they provide unique climate and geographical characteristics that either enhance or reduce the tropical cyclone risk. Guam experiences the most frequent and severe tropical cyclones, which often originate as weak systems close to the equator near Kwajalein and sometimes track far enough north to affect Okinawa, whereas intense storms are the least frequent around Oahu. From assessments of models that simulate well the tropical Pacific climate, it was determined that, with a projected warming climate, the number of tropical cyclones is likely to decrease for Guam and Kwajalein but remain about the same near Okinawa and Oahu; however, the maximum intensity of the strongest storms may increase in most regions. The likelihood of fewer but stronger storms will necessitate new localized assessments of the risk and vulnerabilities to tropical cyclones in the North Pacific