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Afro-descendant women in Esmeraldas, Ecuador, are amongst the most marginalized groups in the country. Living in a region severely affected by environmental degradation due to multiple and overlapping forms of resource extraction, they also face the impacts of drug-trafficking conflicts crossing the Colombian border, as well as institutional and everyday racism. Many of these conditions are rooted in a long history of colonialism. In this article, we highlight the relative absence of Afro-Ecuadorian women's voices, histories and experiences from research on resource extraction and argue that Black feminist theoretical approaches provide an essential tool for understanding intersections of gender, race and activism, as well as (alternatives to) development, and the impacts of natural resource extraction in Ecuador. In so doing, the article proposes a theoretical framework to open up spaces that situate Afro-Ecuadorian women's knowledge at the centre of efforts to resist marginalization and extractivism. [ABSTRACT FROM AUTHOR]

Simulation studies of a section of a spherically imploding plasma liner, formed by the merger of six hypersonic plasma jets, have been performed at conditions relevant to the Plasma Liner Experiment (PLX) [S. C. Hsu et al., IEEE Trans. Plasma Sci. 46, 1951–1961 (2018)]. The main aim of simulations was to study the sensitivity of the detailed structure of plasma liners and their global properties to experimental mass variations and timing jitter across the six plasma jets. Experimentally observable synthetic quantities have been computed using simulation data and compared with the available experimental data. Simulations predicted that the primary oblique shock wave structure is preserved at small experimental variations. At later phases of the liner implosion, primary shocks and, especially, secondary shocks are more sensitive to experimental variations. These conclusions follow from the simulation data and experimental CCD camera images. Small displacements of shock wave structures may also cause significant changes in the synthetic interferometer data at early time. Our studies showed that such global properties of the plasma liners such as the averaged Mach number and averaged ram pressure along the leading edges of plasma liners are less sensitive to experimental variations. Simulation data of the liner structure were largely confirmed by the PLX experimental data. [ABSTRACT FROM AUTHOR]

Spherically imploding plasma liners, formed by merging hypersonic plasma jets, are a proposed standoff driver to compress magnetized target plasmas to fusion conditions (Hsu et al. in IEEE Trans Plasma Sci 40:1287, 2012). In this paper, the parameter space and physics criteria are identified for a subscale, plasma-liner-formation experiment to provide data, e.g., on liner ram-pressure scaling and uniformity, that are relevant for addressing scientific issues of full-scale plasma liners required to achieve fusion conditions. Based on these criteria, we quantitatively estimate the minimum liner kinetic energy and mass needed, which informed the design of a subscale plasma liner experiment now under development. [ABSTRACT FROM AUTHOR]

Animal size is a highly variable trait regulated by complex interactions between biological and environmental processes. Despite the importance of understanding the mechanistic bases of growth, predicting size variation in early stages of development remains challenging. Pedigreed lines of the Pacific oyster (Crassostrea gigas) were crossed to produce contrasting growth phenotypes to analyze the metabolic bases of growth variation in larval stages. Under controlled environmental conditions, substantial growth variation of up to 430% in shell length occurred among 12 larval families. Protein was the major biochemical constituent in larvae, with an average protein-to-lipid content ratio of 2.8.On average, 86%of protein synthesizedwas turned over (i.e. only 14% retained as protein accreted), with a regulatory shift in depositional efficiency resulting in increased protein accretion during later larval growth. Variation in protein depositional efficiency among families did not explain the range in larval growth rates. Instead, changes in protein synthesis rates predicted 72% of growth variation. High rates of protein synthesis to support faster growth, in turn, necessitated greater allocation of the total ATP pool to protein synthesis. An ATP allocation model is presented for larvae of C. gigas that includes the major components (82%) of energy demand: protein synthesis (45%), ion pump activity (20%), shell formation (14%) and protein degradation (3%). The metabolic tradeoffs between faster growth and the need for higher ATP allocation to protein synthesis could be a major determinant of fitness for larvae of different genotypes responding to the stress of environmental change. [ABSTRACT FROM AUTHOR]

Exogenous environmental factors alter growth rates, yet information remains scant on the biochemical mechanisms and energy trade-offs that underlie variability in the growth of marine invertebrates. Here we study the biochemical bases for differential growth and energy utilization (as adenosine triphosphate [ATP] equivalents) during larval growth of the bivalve Crassostrea gigas exposed to increasing levels of experimental ocean acidification (control, middle, and high p CO2, corresponding to ∼400, ∼800, and ∼1100 µatm, respectively). Elevated p CO2 hindered larval ability to accrete both shell and whole-body protein content. This negative impact was not due to an inability to synthesize protein per se , because size-specific rates of protein synthesis were upregulated at both middle and high p CO2 treatments by as much as 45% relative to control p CO2. Rather, protein degradation rates increased with increasing p CO2. At control p CO2, 89% of cellular energy (ATP equivalents) utilization was accounted for by just 2 processes in larvae, with protein synthesis accounting for 66% and sodium-potassium transport accounting for 23%. The energetic demand necessitated by elevated protein synthesis rates could be accommodated either by reallocating available energy from within the existing ATP pool or by increasing the production of total ATP. The former strategy was observed at middle p CO2, while the latter strategy was observed at high p CO2. Increased p CO2 also altered sodium-potassium transport, but with minimal impact on rates of ATP utilization relative to the impact observed for protein synthesis. Quantifying the actual energy costs and trade-offs for maintaining physiological homeostasis in response to stress will help to reveal the mechanisms of resilience thresholds to environmental change. [ABSTRACT FROM AUTHOR]

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Physiological increases in energy expenditure frequently occur in response to environmental stress. Although energy limitation is often invoked as a basis for decreased calcification under ocean acidification, energy-relevant measurements related to this process are scant. In this study we focus on first-shell (prodissoconch I) formation in larvae of the Pacific oyster, Crassostrea gigas. The energy cost of calcification was empirically derived to be≤1.1 μJ (ng CaCO3)-1. Regardless of the saturation state of aragonite (2.77 vs. 0.77), larvae utilize the same amount of total energy to complete first-shell formation. Even though there was a 56% reduction of shell mass and an increase in dissolution at aragonite undersaturation, first-shell formation is not energy limited because sufficient endogenous reserves are available to meet metabolic demand. Further studies were undertaken on larvae from genetic crosses of pedigreed lines to test for variance in response to aragonite undersaturation. Larval families show variation in response to ocean acidification, with loss of shell size ranging from no effect to 28%. These differences show that resilience to ocean acidification may exist among genotypes. Combined studies of bioenergetics and genetics are promising approaches for understanding climate change impacts on marine organisms that undergo calcification. [ABSTRACT FROM AUTHOR]

Understanding and predicting biological stability and change in the face of rapid anthropogenic modifications of ecosystems and geosystems are grand challenges facing environmental and life scientists. Physiologically, organisms withstand environmental stress through changes in biochemical regulation that maintain homeostasis, which necessarily demands tradeoffs in the use of metabolic energy. Evolutionarily, in response to environmentally forced energetic tradeoffs, populations adapt based on standing genetic variation in the ability of individual organisms to reallocate metabolic energy. Combined study of physiology and genetics, separating “Nature and Nurture,” is, thus, the key to understanding the potential for evolutionary adaptation to future global change. To understand biological responses to global change, we need experimentally tractable model species that have the well-developed physiological, genetic, and genomic resources necessary for partitioning variance in the allocation of metabolic energy into its causal components. Model species allow for discovery and for experimental manipulation of relevant phenotypic contrasts and enable a systems-biology approach that integrates multiple levels of analyses to map genotypic-to-phenotypic variation. Here, we illustrate how combined physiological and genetic studies that focus on energy metabolism in developmental stages of a model marine organism contribute to an understanding of the potential to adapt to environmental change. This integrative research program provides insights that can be readily incorporated into individual-based ecological models of population persistence under global change. [ABSTRACT FROM AUTHOR]

For a given chord through a plasma, changes in the line integrated index of refraction as a result of a transverse density gradient can be observed by measuring the angle of deflection of a laser beam. In contrast to laser interferometers, this method of density profile measurement places modest requirements on laser quality and alignment procedures, allowing measurements to be conducted with short coherence length commercial laser diodes and segmented photodiode detectors. A prototype implementation of this scheme has been constructed and tested on the compact toroid injection experiment (CTIX). At densities comparable to magnetic fusion plasmas, laser deflections in the nanoradian range were measured. By assuming a particular density profile, a sensitivity of ∼1012 cm-3/nrad was obtained. This produced estimates of CTIX peak density in reasonable agreement with conventional interferometry data. The final goal of this diagnostic is a simple, reliable, array deployable density profile diagnostic. [ABSTRACT FROM AUTHOR]

summary¶we evaluate united kingdom meteorological office (ukmo) one-month ensemble forecasts of mean sea-level pressure (mslp) in the southern hemisphere (sh) to 60° s, with a special focus on their utility near new zealand (nz). there are 105 9-member ensembles, at approximately two-week intervals, between 1995 and 1999. each forecast is averaged over two successive 15-day periods and verified against the ncep/ncar reanalysis data set. compared to climatology, the skill of the ensemble mean is slightly positive in days 1-15, and slightly negative in days 16-30. skill near nz is slightly lower than the sh averages. for sh-scale circulation patterns (as seen in the first few principal components), skill is greater than for most individual grid points, but is still negligible or negative in days 16-30. moderate skill-spread correlations (ρ ≉-0.5) were found for some skill scores. the way that skill varies with season and the southern oscillation index is consistent with other research but not statistically significant for this small data set. probabilistic forecasts of low and high pressures have skill similar to that of the ensemble mean. the ensemble spread is generally too small, in that the analysis lies within the ensemble less often than the theoretically optimum value of 80% of the time. measured as a fraction of the natural variability, the spread increases substantially with time and latitude: it is less than 0.5 near the equator in days 1-15, and takes values near 1 only at higher latitudes during days 16-30. the initial sequential structure of the ensembles (a consequence of the use of time lags in their genesis) is still apparent in days 1-15 but has disappeared by days 16-30. three potential alternatives to the ensemble mean were all found to have less skill than it. [ABSTRACT FROM AUTHOR]

Several studies have examined predictors of mortality among elderly patients hospitalized with heart failure. In some, elderly African American patients hospitalized for heart failure were reported to have lower risk-adjusted in-hospital mortality compared with Whites. Whether this difference is sustained in the long term and what factors account for this difference remain poorly understood. The objective of this study was to compare risk-adjusted short-term and long-term mortality of a cohort of elderly African American and White patients hospitalized for heart failure to all 30 hospitals in northeast Ohio. The database used for this analysis includes information on demographics and detailed clinical information abstracted from patients' hospital records. Crude and adjusted 30-day and 18-month survival were compared using Kaplan Meier method and logistic regression models for multivariate analysis. African American patients had significantly lower 30-day mortality compared with Whites. However, this difference diminished over time and when adjusted for important explanatory covariates, including "do not resuscitate" orders. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to a previously published editorial by David E. Davis entitled "Job Shortage?".

A letter to the editor is presented in response to the article "Job Retraining," by Alice Kenyon in the April 1972 issue.

A letter to the editor is presented in response to the article "Teaching-Research," by Jeffrey J. W. Baker in the March 15, 1970 issue.