Genetic variability and differentiation in niche components of marine phytoplankton species

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution January, 1980The acclimated asexual reproduction rates of many clones of Emiliania huxleyi (82), Gephrocapsa oceanica (19), Cyclococcolithina leptopora (31), Prorocentrum micans (28), Dissodinium lunula (22), Thoracosphaera heimi (20), and Gonyaulax tamarensis (83) were measured in several light and temperature regimes. The data were used to determine the amount of genetic variability and the spatial patterns of genetic differentiation in these species. None of the species examined exist purely as clones in nature. Statistically significant genetic variability is found even among clones isolated from single water bottles. The amount of genetic variability in asexual reproduction rates in individual phytoplankton populations ranged from 3 t o 13% (coefficients of variation). There is no obvious relationship between the amounts of genetic variability in the populations and the variability or predictability of the environments from which they were collected. No genetic differentiation was found within the Sargasso Sea in any of the oceanic species, but strong genetic differentiation was found between oceanic and neritic populations of the two species (E. huxleyi and G. oceanica) found on both sides of the Gulf Stream. The spatial patterns of genetic differentiation appear to be different in these two species, however. Genetic differentiation was found between populations from the Sargasso Sea and the slope water off New England is G. oceanica. In E. huxleyi the Sargasso Sea and slope water were similar, but different from the Gulf of Maine populations. Of the three species for which populations were collected at different times of the year (E. huxleyi, C. leptopora, and T. heimi), there is evidence of significant seasonal genetic changes in only one (C. leptopora).This research was supported by the National Science Foundation, Grant Nos. OCE 77-10876, OCE 78-08858, and OCE 79-03621. I was supported by a National Science Foundation Graduate Fellowship, a National Science Foundation National Needs Traineeship, and the Woods Hole Oceanographic Institution Graduate Education Program

Coccolith Morphology and Paleoclimatology - 2. Cell Ultrastructure and Formation of Coccoliths in Cyclococcolithina leptopora (Murray and Blackman) Wilcoxon and Gephyrocapsa oceanica Kamptner.

Current interest in utilization of coccoliths for paleoclimate reconstruction necessitates background information on environmental limits for growth and coccolith production as well as examination of cell ultrastructure in specimens collected in the field and in cultured representatives. Successful isolation of the two geologically important species Gephyrocapsa oceanica (strain A674) and Cyclococcolithina leptopora (strain A650) allows investigation of ultrastructure in cultured forms. Fine structure of cells and coccoliths was observed in the SEM using critical point dried preparations and ultrastructure was examined with the transmission electron microscope. Coccoliths are formed intracellularly and appear to form within Golgi-derived vesicles located near the nuclear membrane. Formation and development of coccoliths in the two species resemble these processes in Emiliania huxleyi but differ from those of Cricosphaera carterae, notably in the absence of coccolithosomes and scales and in the fact that coccoliths are produced intracellularly one at a time

Lunar Architecture Team - Phase 2 Habitat Volume Estimation: "Caution When Using Analogs"

The lunar surface habitat will serve as the astronauts' home on the moon, providing a pressurized facility for all crew living functions and serving as the primary location for a number of crew work functions. Adequate volume is required for each of these functions in addition to that devoted to housing the habitat systems and crew consumables. The time constraints of the LAT-2 schedule precluded the Habitation Team from conducting a complete "bottoms-up" design of a lunar surface habitation system from which to derive true volumetric requirements. The objective of this analysis was to quickly derive an estimated total pressurized volume and pressurized net habitable volume per crewmember for a lunar surface habitat, using a principled, methodical approach in the absence of a detailed design. Five "heuristic methods" were used: historical spacecraft volumes, human/spacecraft integration standards and design guidance, Earth-based analogs, parametric "sizing" tools, and conceptual point designs. Estimates for total pressurized volume, total habitable volume, and volume per crewmember were derived using these methods. All method were found to provide some basis for volume estimates, but values were highly variable across a wide range, with no obvious convergence of values. Best current assumptions for required crew volume were provided as a range. Results of these analyses and future work are discussed

SKYLAB II - Making a Deep Space Habitat from a Space Launch System Propellant Tank

Called a "House in Space," Skylab was an innovative program that used a converted Saturn V launch vehicle propellant tank as a space station habitat. It was launched in 1973 fully equipped with provisions for three separate missions of three astronauts each. The size and lift capability of the Saturn V enabled a large diameter habitat, solar telescope, multiple docking adaptor, and airlock to be placed on-orbit with a single launch. Today, the envisioned Space Launch System (SLS) offers similar size and lift capabilities that are ideally suited for a Skylab type mission. An envisioned Skylab II mission would employ the same propellant tank concept; however serve a different mission. In this case, the SLS upper stage hydrogen tank is used as a Deep Space Habitat (DSH) for NASA s planned missions to asteroids, Earth-Moon Lagrangian point and Mars

Filtration efficiency of air conditioner filters and face masks to limit exposure to aerosolized algal toxins

Harmful algal blooms (HABs) can generate toxins that can be aerosolized and negatively impact human health through inhalation. HABs are often found in waterways near residences, therefore, aerosolized HAB toxins can potentially affect both indoor and outdoor air quality. Given that HABs are predicted to increase worldwide, effective mitigation strategies are needed to prevent the inhalation of aerosolized HAB toxins. In this work, we characterized both the particle filtration efficiency using particle sizing instruments as well as the mass concentration of different congeners of aerosolized microcystin (MC) toxins that penetrate through commercially available face masks and air conditioner (AC) filters. Particles were generated from cultures of the toxin-producing cyanobacteria Microcystis aeruginosa. Hydrophobic congeners of microcystin including MC-LF and MC-LW were enriched in aerosols compared to water, with MC-LR being the most abundant, which has implications for the toxicity of inhalable particles generated from HAB-contaminated waters. Particle transmission efficiencies and toxin filtration efficiencies scaled with the manufacturer-provided filter performance ratings. Up to 80% of small, microcystin-containing aerosols were transmitted through AC filters with low filter performance ratings. In contrast, both face masks as well as AC filters with high filter performance ratings efficiently removed toxin-containing particles to below limits of quantification. Our findings suggest that face masks and commercially available AC filters with high filtration efficiency ratings are suitable mitigation strategies to avoid indoor and outdoor air exposure to aerosolized HAB toxins. This work also has relevance for reducing airborne exposure to other HAB toxins, non-HAB toxins, pathogens, and viruses, including SARS-CoV-2, the virus responsible for the COVID-19 pandemic

Centers for Oceans and Human Health : a unified approach to the challenge of harmful algal blooms

© 2008 Author et al. This is an open access article distributed under the terms of the Creative Commons Attribution License The definitive version was published in Environmental Health 7 (2008): S2, doi:10.1186/1476-069X-7-S2-S2.Harmful algal blooms (HABs) are one focus of the national research initiatives on Oceans and Human Health (OHH) at NIEHS, NOAA and NSF. All of the OHH Centers, from the east coast to Hawaii, include one or more research projects devoted to studying HAB problems and their relationship to human health. The research shares common goals for understanding, monitoring and predicting HAB events to protect and improve human health: understanding the basic biology of the organisms; identifying how chemistry, hydrography and genetic diversity influence blooms; developing analytical methods and sensors for cells and toxins; understanding health effects of toxin exposure; and developing conceptual, empirical and numerical models of bloom dynamics. In the past several years, there has been significant progress toward all of the common goals. Several studies have elucidated the effects of environmental conditions and genetic heterogeneity on bloom dynamics. New methods have been developed or implemented for the detection of HAB cells and toxins, including genetic assays for Pseudo-nitzschia and Microcystis, and a biosensor for domoic acid. There have been advances in predictive models of blooms, most notably for the toxic dinoflagellates Alexandrium and Karenia. Other work is focused on the future, studying the ways in which climate change may affect HAB incidence, and assessing the threat from emerging HABs and toxins, such as the cyanobacterial neurotoxin β-N-methylamino-L-alanine. Along the way, many challenges have been encountered that are common to the OHH Centers and also echo those of the wider HAB community. Long-term field data and basic biological information are needed to develop accurate models. Sensor development is hindered by the lack of simple and rapid assays for algal cells and especially toxins. It is also critical to adequately understand the human health effects of HAB toxins. Currently, we understand best the effects of acute toxicity, but almost nothing is known about the effects of chronic, subacute toxin exposure. The OHH initiatives have brought scientists together to work collectively on HAB issues, within and across regions. The successes that have been achieved highlight the value of collaboration and cooperation across disciplines, if we are to continue to advance our understanding of HABs and their relationship to human health.This work was funded through grants from the NSF/NIEHS Centers for Oceans and Human Health, NIEHS P50 ES012742 and NSF OCE-043072 (DLE and DMA), NSF OCE04-32479 and NIEHS P50 ES012740 (PB and RRB), NSF OCE-0432368 and NIEHS P50 ES12736 (LEB), NIEHS P50 ES012762 and NSF OCE-0434087 (RCS, KAL, MSP, MLW, and KAH). Additional support was provided by the ECOHAB Grant program NSF Grant OCE-9808173 and NOAA Grant NA96OP0099 (DMA), NOAA OHHI NA04OAR4600206 (RRB) and Washington State Sea Grant NA16RG1044 (RCS). KAL and VLT were supported in part by the West Coast Center for Oceans and Human Health (WCCOHH) as part of the NOAA Oceans and Human Health Initiative

Stellar Spectroscopy in the Near-infrared with a Laser Frequency Comb

The discovery and characterization of exoplanets around nearby stars is driven by profound scientific questions about the uniqueness of Earth and our Solar System, and the conditions under which life could exist elsewhere in our Galaxy. Doppler spectroscopy, or the radial velocity (RV) technique, has been used extensively to identify hundreds of exoplanets, but with notable challenges in detecting terrestrial mass planets orbiting within habitable zones. We describe infrared RV spectroscopy at the 10 m Hobby-Eberly telescope that leverages a 30 GHz electro-optic laser frequency comb with nanophotonic supercontinuum to calibrate the Habitable Zone Planet Finder spectrograph. Demonstrated instrument precision <10 cm/s and stellar RVs approaching 1 m/s open the path to discovery and confirmation of habitable zone planets around M-dwarfs, the most ubiquitous type of stars in our Galaxy

The United Kingdom and British Empire: A Figurational Approach

Drawing upon the work of Norbert Elias and the process [figurational] sociology perspective, this article examines how state formation processes are related to, and, affected by, expanding and declining chains of international interdependence. In contrast to civic and ethnic conceptions, this approach focuses on the emergence of the nation/nation-state as grounded in broader processes of historical and social development. In doing so, state formation processes within the United Kingdom are related to the expansion and decline of the British Empire. That is, by focusing on the functional dynamics that are embedded in collective groups, one is able to consider how the UK’s ‘state’ and ‘imperial’ figurations were interdependently related to changes in both the UK and the former British Empire. Consequently, by locating contemporary UK relations in the historical context of former imperial relationships, nationalism studies can go ‘beyond’ the nation/nation-state in order to include broader processes of imperial expansion and decline. Here, the relationship between empire and nationalism can offer a valuable insight into contemporary political movements, especially within former imperial groups

CCNE1 and survival of patients with tubo-ovarian high-grade serous carcinoma: An Ovarian Tumor Tissue Analysis consortium study

BACKGROUND: Cyclin E1 (CCNE1) is a potential predictive marker and therapeutic target in tubo-ovarian high-grade serous carcinoma (HGSC). Smaller studies have revealed unfavorable associations for CCNE1 amplification and CCNE1 overexpression with survival, but to date no large-scale, histotype-specific validation has been performed. The hypothesis was that high-level amplification of CCNE1 and CCNE1 overexpression, as well as a combination of the two, are linked to shorter overall survival in HGSC. METHODS: Within the Ovarian Tumor Tissue Analysis consortium, amplification status and protein level in 3029 HGSC cases and mRNA expression in 2419 samples were investigated. RESULTS: High-level amplification (>8 copies by chromogenic in situ hybridization) was found in 8.6% of HGSC and overexpression (>60% with at least 5% demonstrating strong intensity by immunohistochemistry) was found in 22.4%. CCNE1 high-level amplification and overexpression both were linked to shorter overall survival in multivariate survival analysis adjusted for age and stage, with hazard stratification by study (hazard ratio [HR], 1.26; 95% CI, 1.08-1.47, p = .034, and HR, 1.18; 95% CI, 1.05-1.32, p = .015, respectively). This was also true for cases with combined high-level amplification/overexpression (HR, 1.26; 95% CI, 1.09-1.47, p = .033). CCNE1 mRNA expression was not associated with overall survival (HR, 1.00 per 1-SD increase; 95% CI, 0.94-1.06; p = .58). CCNE1 high-level amplification is mutually exclusive with the presence of germline BRCA1/2 pathogenic variants and shows an inverse association to RB1 loss. CONCLUSION: This study provides large-scale validation that CCNE1 high-level amplification is associated with shorter survival, supporting its utility as a prognostic biomarker in HGSC