152 research outputs found
A Comparison of Three Methods for Visually Assessing Reef Fish Communities: Time and Area Compensated
Reef fish assemblage survey results using Transect, Point, and Random in situ visual assessment techniques were evaluated and compared on a coral reef biotope off the southwestern coast of Puerto Rico. Parameters compared were: number of species, number of individuals, and species diversity (H\u27). No significant effect attributable to the time-of-day when the surveys were conducted was noted to occur. Variability in observations between divers was not noted for any of the dependent variables while conducting the Transect method. Divers using the Random technique recorded the highest number of species per survey, while the assemblage parameters recorded using Transect and Point methods were statistically similar for most dependent variables. Point surveys, however, had a higher and less variable species diversity. When the data were adjusted for amount of survey time and area it was determined that divers were more efficient in sampling numbers of individuals when using the Transect method
Macondo-1 well oil-derived polycyclic aromatic hydrocarbons
Mesozooplankton (>200 mm) collected in August and September of 2010 from the northern Gulf of Mexico show evidence of exposure to polycyclic aromatic hydrocarbons (PAHs). Multivariate statistical analysis revealed that distributions of PAHs extracted from mesozooplankton were related to the oil released from the ruptured British Petroleum Macondo-1 (M-1) well associated with the R/V Deepwater Horizon blowout. Mesozooplankton contained 0.03–97.9 ng g 1 of total PAHs and ratios of fluoranthene to fluoranthene + pyrene less than 0.44, indicating a liquid fossil fuel source. The distribution of PAHs isolated from mesozooplankton extracted in this study shows that the 2010 Deepwater Horizon spill may have contributed to contamination in the northern Gulf of Mexico ecosystem
Political masculinities, crisis tendencies, and social transition: Toward an understanding of change
This introduction to the special issue on “Political Masculinities and Social Transition” rethinks the notion of “crisis in masculinity” and points to its weaknesses, such as cyclical patterns and chronicity. Rather than viewing key moments in history as points of rupture, we understand social change as encompassing ongoing transitions marked by a “fluid nature” (Montecinos 2017, 2). In line with this, the contributions examine how political masculinities are implicated within a wide range of social transitions, such as nation building after war, the founding of a new political party in response to an economic crisis, an “authoritarian relapse” of a democracy, attempts at changing society through terrorism, rapid industrialization as well as peace building in conflict areas. Building on Starck and Sauer’s definition of “political masculinities” we suggest applying the concept to instances in which power is explicitly either being (re)produced or challenged. We distinguish between political masculinities that are more readily identified as such (e.g., professional politicians) and less readily identified political masculinities (e.g., citizens), emphasizing how these interact with each other. We ask whether there is a discernible trajectory in the characteristics of political masculinities brought about by social transition that can be confirmed across cultures. The contributors’ findings indicate that these political masculinities can contribute to different kinds of change that either maintain the status quo, are progressive, retrogressive, or a mixture of these. Revolutionary transitions, it seems, often promote the adherence to traditional forms of political masculinity, whereas more reformatory transition leaves discursive spaces for argument
Macondo-1 well oil-derived polycyclic aromatic hydrocarbons in mesozooplankton from the northern Gulf of Mexico
Copyright 2012 by the American Geophysical UnionMesozooplankton (>200 μm) collected in August and September of 2010 from the northern Gulf of Mexico show evidence of exposure to polycyclic aromatic hydrocarbons (PAHs). Multivariate statistical analysis revealed that distributions of PAHs extracted from mesozooplankton were related to the oil released from the ruptured British Petroleum Macondo-1 (M-1) well associated with the R/VDeepwater Horizon blowout. Mesozooplankton contained 0.03–97.9 ng g−1 of total PAHs and ratios of fluoranthene to fluoranthene + pyrene less than 0.44, indicating a liquid fossil fuel source. The distribution of PAHs isolated from mesozooplankton extracted in this study shows that the 2010 Deepwater Horizon spill may have contributed to contamination in the northern Gulf of Mexico ecosystem
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Macondo-1 well oil-derived polycyclic aromatic hydrocarbons in mesozooplankton from the northern Gulf of Mexico
Mesozooplankton (>200 μm) collected in August and September of 2010 from the northern Gulf of Mexico show evidence of exposure to polycyclic aromatic hydrocarbons (PAHs). Multivariate statistical analysis revealed that distributions of PAHs extracted from mesozooplankton were related to the oil released from the ruptured British Petroleum Macondo-1 (M-1) well associated with the R/V Deepwater Horizon blowout. Mesozooplankton contained 0.03–97.9 ng g⁻¹ of total PAHs and ratios of fluoranthene to fluoranthene + pyrene less than 0.44, indicating a liquid fossil fuel source. The distribution of PAHs isolated from mesozooplankton extracted in this study shows that the 2010 Deepwater Horizon spill may have contributed to contamination in the northern Gulf of Mexico ecosystem
M31 satellite masses compared to CDM subhaloes
We have selected the positions of 54 6.7 GHz methanol masers from the Methanol Multibeam Survey catalogue, covering a range of longitudes between 20◦ and 34◦ of the Galactic plane. These positions were mapped in the J = 3−2 transition of both the 13CO and C18O lines. A total of 58 13CO emission peaks are found in the vicinity of these maser positions. We search for outflows around all 13CO peaks, and find evidence for high-velocity gas in all cases, spatially resolving the red and blue outflow lobes in 55 cases. Of these sources, 44 have resolved kinematic distances, and are closely associated with the 6.7 GHz masers, a subset referred to as Methanol Maser Associated Outflows (MMAOs). We calculate the masses of the clumps associated with each peak using 870 µm continuum emission from the ATLASGAL survey. A strong correlation is seen between the clump mass and both outflow mass and mechanical force, lending support to models in which accretion is strongly linked to outflow. We find that the scaling law between outflow activity and clump masses observed for low-mass objects, is also followed by the MMAOs in this study, indicating a commonality in the formation processes of low-mass and high-mass stars
Scanning Tunneling Microscopy Study and Nanomanipulation of Graphene-Coated Water on Mica
We study interfacial water trapped between a sheet of graphene and a
muscovite (mica) surface using Raman spectroscopy and ultra-high vacuum
scanning tunneling microscopy (UHV-STM) at room temperature. We are able to
image the graphene-water interface with atomic resolution, revealing a layered
network of water trapped underneath the graphene. We identify water layer
numbers with a carbon nanotube height reference. Under normal scanning
conditions, the water structures remain stable. However, at greater electron
energies, we are able to locally manipulate the water using the STM tip.Comment: In press, 5 figures, supplementary information at Nano Letters
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