3,174 research outputs found

    Interrupting the social amplification of risk process: a case study in collective emissions reduction

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    One of the main approaches we have for studying the progressive divergence of understandings around a risk issue is that of social risk amplification. This article describes a case study of a particular environmental contaminant, a chemical flame retardant that could be interpreted as having produced a risk amplifying process. It describes in particular how a group of industrial organizations acted collectively to reduce emissions of this contaminant, in an apparent attempt to avert regulation and boycotts—that is, to intercept the social amplification process and avoid its secondary effects. The aim of the study was to investigate the constitutive qualities of this collective action: the qualities that defined it and made it effective in the eyes of those involved. These include institutionalisation and independence, the ability to confer individual as well as collective benefit, the capacity to attract (rather than avoid) criticism, and the ‘branding’ that helps communicate what otherwise appear to be a set of unconnected, local actions. Although the risk amplification framework has been criticised for implying that there is some externally given risk level that is subsequently amplified, it does appear to capture the mentality of actors involved in issues of this kind. They talk and act as though they believe they are participants in a risk amplification process

    Solving the BM Camelopardalis puzzle

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    BM Camelopardalis (=12 Cam) is a chromospherically active binary star with a relatively large orbital eccentricity. Systems with large eccentricities usually rotate pseudosynchronously. However, BM Cam has been a puzzle since its observed rotation rate is virtually equal to its orbital period indicating synchronization. All available photometry data for BM Cam have been collected and analyzed. Two models of modulated ellipticity effect are proposed, one based on equilibrium tidal deformation of the primary star and the other on a dynamical tidal effect. When the starspot variability is removed from the data, the dynamical tidal model was the better approximation to the real physical situation. The analysis indicates that BM Cam is not rotating pseudosynchronously but rotating in virtual synchronism after all

    Targets for the MalI repressor at the divergent Escherichia coliK-12malX-malI promoters

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    Random mutagenesis has been used to identify the target DNA sites for the MalI repressor at the divergent Escherichia coli K-12 malX-malI promoters. The malX promoter is repressed by MalI binding to a DNA site located from position -24 to position -9, upstream of the malX promoter transcript start. The malI promoter is repressed by MalI binding from position +3 to position +18, downstream of the malI transcript start. MalI binding at the malI promoter target is not required for repression of the malX promoter. Similarly, MalI binding at the malX promoter target is not required for repression of the malI. Although the malX and malI promoters are regulated by a single DNA site for cyclic AMP receptor protein, they function independently and each is repressed by MalI binding to a different independent operator site

    Modelling the potential for permafrost development on a radioactive waste geological disposal facility in Great Britain

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    The safety case for a geological disposal facility (GDF) for radioactive waste based in Great Britain must consider the potential impact on the repository environment of permafrost during the 1 million years following GDF closure. The depth of penetration of permafrost, defined as ground which remains at or below 0 °C for at least 2 consecutive years, has been modelled for a future climate that uses the climate of the last glacial–interglacial cycle as an analogue. Two future climates are considered; an average estimate case considered to be the best estimate of ground surface temperatures during the last glacial–interglacial cycle, and a cold estimate case considered to be an extreme cold, but plausible future climate. Maximum modelled permafrost thicknesses across Great Britain range from 20 to 180 m for the average estimate climate and 180–305 m for the cold estimate climate. The presence of ice cover is an important determinant on permafrost development. Thick permafrost evolves during long periods of cold-based ice cover and during periods of ice retreat that results in ground exposure to very cold air temperatures. Conversely, warm-based ice has an insulating effect, shielding the ground from cold air temperatures that retards permafrost development. For a GDF at a depth greater than that predicted to be directly affected by permafrost, phenomena associated with permafrost, e.g., enhanced groundwater salinity at depth, will need to be taken into account when considering the impact on the engineered and natural barriers associated with a GDF

    Spawning, egg development, and early life history dynamics of arrowtooth flounder (Atheresthes stomias) in the Gulf of Alaska

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    Arrowtooth flounder (Atheresthes stomias) has the highest biomass of any groundfish species in the Gulf of Alaska, is a voracious predator of age 1 walleye pollock (Theragra chalcogramma), and is a major component in the diet of Steller sea lions (Eumetopias jubatus). Owing to its ecological importance in the Gulf of Alaska and the limited information available on its reproduction, interest has intensified in describing its spawning and early life history. A study was undertaken in late January–February 2001–2003 in the Gulf of Alaska to obtain information on adult spawning location, depth distribution, and sexual maturity, and to obtain fertilized eggs for laboratory studies. Adults were found 200–600 m deep east of Kodiak Island over the outer continental shelf and upper slope, and southwest along the shelf break to the Shumagin Islands. Most ripe females (oocytes extruded with light pressure) were found at 400 m and most ripe males (milt extruded with light pressure) were found at depths ≥450 m. Eggs were fertilized and incubated in the laboratory at 3.0°, 4.5°, and 6.0°C. Eggs were reared to hatching, but larvae did not survive long enough to complete yolk absorption and develop pigment. Eggs were staged according to morphological hallmarks and incubation data were used to produce a stage duration table and a regression model to estimate egg age based on water temperature and developmental stage. Arrowtooth flounder eggs (1.58–1.98 mm in diameter) were collected in ichthyoplankton surveys along the continental shelf edge, primarily at depths ≥400 m. Early-stage eggs were found in tows that sampled to depths of ≥450 m. Larvae, which hatch between 3.9 and 4.8 mm standard length, increased in abundance with depth. Observations on arrowtooth flounder eggs and early-stage larvae were used to complete the description of the published partial developmental series.(PDF file contains 34 pages.

    Activation of σ28-dependent transcription inEscherichia coliby the cyclic AMP receptor protein requires an unusual promoter organization

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    The Escherichia coli aer regulatory region contains a single promoter that is recognized by RNA polymerase containing the flagellar sigma factor, σ28. Expression from this promoter is dependent on direct activation by the cyclic AMP receptor protein, which binds to a target centred 49.5 base pairs upstream from the transcript start. Activator-dependent transcription from the aer promoter was reconstituted in vitro, and a tethered inorganic nuclease was used to find the position of the C-terminal domains of the RNA polymerase α subunits in transcriptionally competent open complexes. We report that the ternary activator-RNA polymerase-aer promoter open complex is organized differently from complexes at previously characterized promoters. Among other E. coli promoters recognized by RNA polymerase containing σ28, only the trg promoter is activated directly by the cyclic AMP receptor protein. The organization of the different promoter elements and the activator binding site at the trg promoter is the same as at the aer promoter, suggesting a common activation mechanism

    Guide to the identification of larval and early juvenile pricklebacks (Perciformes: Zoarcoidei: Stichaeidae) in the northeastern Pacific Ocean and Bering Sea

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    Stichaeidae, commonly referred to as pricklebacks, are intertidal and subtidal fishes primarily of the North Pacific Ocean. Broad distribution in relatively inaccessible and undersampled habitats has contributed to a general lack of information about this family. In this study, descriptions of early life history stages are presented for 25 species representing 18 genera of stichaeid fishes from the northeastern Pacific Ocean, Bering Sea, and Arctic Ocean Basin. Six of these species also occur in the North Atlantic Ocean. Larval stages of 16 species are described for the first time. Additional information or illustrations intended to augment previous descriptions are provided for nine species. For most taxa, we present adult and larval distributions, descriptions of morphometric, meristic, and pigmentation characters, and species comparisons, and we provide illustrations for preflexion through postflexion or transformation stages. New counts of meristic features are reported for several species

    Early Mesozoic Paleotectonic-Paleogeographic Reconstruction of Southern Sierra Nevada Region

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    A paleotectonic-paleogeographic reconstruction was based on structural, petrologic, and geochronologic studies of pre-Sierra Nevada batholith framework rocks exposed between the San Joaquin River and the Garlock fault. Most available fossil data from roof pendants of this region indicate Late Triassic to Early Jurassic ages. An additional fossil locality from the western wall rocks yields a Late Permian Tethyan fauna. This is a maximum age for the enclosing rocks, for the fossils are in a limestone olistolith. As yet there is no sign of Paleozoic strata in the region except perhaps along the eastern Sierran crest in small metamorphic septa, and in the western foothills where ophiolitic rocks are present

    Hemoglobin genotype has minimal influence on the physiological response of juvenile atlantic cod (Gadus morhua) to environmental challenges

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    Hemoglobin (Hb) polymorphism in cod is associated with temperature‐related differences in biogeographical distribution, and several authors have suggested that functional characteristics of the various hemoglobin isoforms (HbIs) directly influence phenotypic traits such as growth rate. However, no study has directly examined whether Hb genotype translates into physiological differences at the whole animal level. Thus, we generated a family of juvenile Atlantic cod consisting of all three main Hb genotypes (HbI‐1/1, HbI‐2/2, and HbI‐1/2) by crossing a single pair of heterozygous parents, and we compared their metabolic and cortisol responses to an acute thermal challenge (10&deg;C to their critical thermal maximum [CTM] or 22&deg;C, respectively) and tolerance of graded hypoxia. There were no differences in routine metabolism (at 10&deg;C), maximum metabolic rate, metabolic scope, CTM (overall mean 22.9&deg; &plusmn; 0.2&deg;C), or resting and poststress plasma cortisol levels among Hb genotypes. Further, although the HbI‐1/1 fish grew more (by 15%&ndash;30% during the first 9 mo) when reared at 10&deg; &plusmn; 1&deg;C and had a slightly enhanced hypoxia tolerance at 10&deg;C (e.g., the critical O2 levels for HbI‐1/1, HbI‐2/2, and HbI‐1/2 cod were 35.56% &plusmn; 1.24%, and 40.20% &plusmn; 1.99% air saturation, respectively), these results are contradictory to expectations based on HbI functional properties. Thus, our findings (1) do not support previous assumptions that growth rate differences among cod Hb genotypes result from a more efficient use of the oxygen supply&mdash;that is, reduced standard metabolic rates and/or increased metabolic capacity&mdash;and (2) suggest that in juvenile cod, there is no selective advantage to having a particular Hb genotype with regards to the capacity to withstand ecologically relevant environmental challenges.<br /

    Expanding the Entamoeba Universe: New Hosts Yield Novel Ribosomal Lineages.

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    Removing the requirement for cell culture has led to a substantial increase in the number of lineages of Entamoeba recognized as distinct. Surveying the range of potential host species for this parasite genus has barely been started and it is clear that additional sampling of the same host in different locations often identifies additional diversity. In this study, using small subunit ribosomal RNA gene sequencing, we identify four new lineages of Entamoeba, including the first report of Entamoeba from an elephant, and extend the host range of some previously described lineages. In addition, examination of microbiome data from a number of host animals suggests that substantial Entamoeba diversity remains to be uncovered
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