Integral field spectroscopy with the GEMINI multiobject spectrographs

We describe the integral field unit (IFU) which converts the Gemini Multiobject Spectrograph (GMOS) installed on the Gemini-North telescope to an integral field spectrograph,which produces spectra over a contiguous field of view of 7 × 5 arcsec with spatial sampling of 0.2 arcsecover the wavelength range 0.4-1.0 μm.GMOS is converted to this mode by the remote insertion of the IFU into thebeam in place of the masks used for the multiobject mode. A separate fieldof half the area of the main field, but otherwise identical, is alsoprovided to improve background subtraction. The IFU contains 1500lenslet-coupled fibres and was the first facility of any type for integralfield spectroscopy employed on an 8/10 m telescope.We describe the design, construction and testing of the GMOS IFU and present measurements of the throughput both in the laboratory and at the telescope. We compare these with a theoretical prediction made before construction started. All are in good agreement with each other, with the on-telescope throughput exceeding 60% (averaged over wavelength). Finallywe show an example of data obtained during commissioning to illustrate the power of the device.     

Mussel Periostracum from Deep-Sea Redox Communities as a Microbial Habitat: 3. Secondary Inhabitants

Abstract. Vacated microborings in periostracum of live mussels of the Florida Escarpment redox community (depth of 3266 m) become a habitat for a prolific secondary microbiota consisting of a variety of prokaryotic and a few eukaryotic organisms. Periostracum surface is also colonized by diverse microorganisms, dominated by presumed chemolithotrophic bacteria with stacks of intracellular lamellae. Unlike sheltered microflora within borings, the surface community is heavily grazed upon by numerous archaeogastropods and ciliates.     

Monumental space and the uncanny

This paper takes up the attempt to theorize the relation between the subjectivity of the political actor and the ideological aura of the monumental site. It does this with reference to the spatial history of Strijdom Square in Pretoria, South Africa, a cultural precinct and monumental space which was the site of a series of brutal racist killings committed by the Square’s unrelated namesake, militant right-winger Barend Strydom. This troubling intersection of subjectivity, space and ideology represents something of an explanatory limit for spatio-discursive approaches, certainly in as much as they are ill-equipped to conceptualize the powerfully affective, bodily and fantasmatic qualities of monumental spaces. In contrast to such approaches I offer a psychoanalytically informed account which grapples with the individualized and imaginative identities of space, with space as itself a form of subjectivity. I do this so as understand the ideological aura of monuments as importantly linked to the ‘intersubjectivity’ of subject and personified space. I then turn to Freud’s notion of the uncanny as a theory able to explain a series of disturbing affects of monuments, such as those of ‘embodied absence’ and ‘disembodied presence’. These and similar affects of ‘ontological dissonance’ (such as unexplained instances of doubling or repetition) may function in an ideological manner, both so as to impose a ‘supernaturalism of power’, and to effect an uncanny form of interpellation.     

Phylogeography of the pelagic fish Seriola lalandi at different scales: confirmation of inter-ocean population structure and evaluation of southern African genetic diversity

The study investigated the global and regional phylogeography of the yellowtail kingfish Seriola lalandi by examining genetic diversity and population genetic structure of this species at inter-and intra-ocean level and on a regional scale. DNA fragments of two mitochondrial genes, cytochrome b (Cytb) and cytochrome c oxidase subunit I (COI) and one nuclear gene, recombination activating gene 1 (RAG1), were sequenced to investigate the global-scale phylogeography of this species. The population genetic structure within the South Pacific, as well as along the South African coastline, was examined further using six microsatellite markers. Three distinct clades were identified for S. lalandi, which correspond with previously described subspecies of the North-East Pacific, North-West Pacific and the Southern Hemisphere. Within the latter, additional divergence was observed between the South Pacific and the South-East Atlantic regions. Divergence estimates were indicative of a Pacific origin for S. lalandi populations, because of Pleistocene vicariant events. Microsatellite analyses revealed overall significant genetic differentiation between South African and South Pacific samples. This corroborates recent findings on the global phylogeography of the species. No population differentiation was observed within South Africa, indicating high levels of gene flow.     

Age of the Pomeranian ice‐marginal position in northeastern Germany determined by Optically Stimulated Luminescence (OSL) dating of glaciofluvial sediments

Lüthgens, C., Böse, M. & Preusser, F. 2011: Age of the Pomeranian ice‐marginal position in northeastern Germany determined by Optically Stimulated Luminescence (OSL) dating of glaciofluvial sediments. Boreas, 10.1111/j.1502‐3885.2011.00211.x. ISSN 0300‐9843 The Pomeranian ice margin is one of the most prominent ice‐marginal features of the Weichselian glaciation in northern Europe. Previous results of surface‐exposure dating (SED) of this ice margin disagree with established chronologies and ice retreat patterns, i.e. are much younger than previously expected. We crosscheck the age of the Pomeranian ice‐marginal position in northeastern Germany using single‐grain quartz Optically Stimulated Luminescence (OSL) dating of glaciofluvial sediments. OSL dating indicates an active ice margin between 20.1±1.6 ka and 19.4±2.4 ka forming outwash plains attributed to the Pomeranian ice‐marginal position. On the basis of these results, we suggest a critical reassessment of previous SED data available for the Pomeranian ice‐marginal position within their respective regional geomorphological contexts. From a process‐based point of view, SED ages derived from glacigenic boulders document the stabilization of the landscape after melting of dead ice and landscape transformation under periglacial conditions rather than the presence of an ice margin. SED indicates a first phase of boulder stabilization at around 16.4±0.7 ka, followed by landscape stabilization within the area attributed to the recessional Gerswalder subphase around 15.2±0.5 ka. A final phase of accumulation of glaciolacustrine and glaciofluvial sediments at around 14.7±1.0 ka documents the melting of buried dead ice at that time.     

Thermal maturity and organic composition of Pennsylvanian coals and carbonaceous shales, north-central Texas: Implications for coalbed gas potential

Thermal maturity was determined for about 120 core, cuttings, and outcrop samples to investigate the potential for coalbed gas resources in Pennsylvanian strata of north-central Texas. Shallow (< 600 m; 2000 ft) coal and carbonaceous shale cuttings samples from the Middle-Upper Pennsylvanian Strawn, Canyon, and Cisco Groups in Archer and Young Counties on the Eastern Shelf of the Midland basin (northwest and downdip from the outcrop) yielded mean random vitrinite reflectance (R_o) values between about 0.4 and 0.8%. This range of R_o values indicates rank from subbituminous C to high volatile A bituminous in the shallow subsurface, which may be sufficient for early thermogenic gas generation. Near-surface (< 100 m; 300 ft) core and outcrop samples of coal from areas of historical underground coal mining in the region yielded similar R_o values of 0.5 to 0.8%. Carbonaceous shale core samples of Lower Pennsylvanian strata (lower Atoka Group) from two deeper wells (samples from ~ 1650 m; 5400 ft) in Jack and western Wise Counties in the western part of the Fort Worth basin yielded higher R_o values of about 1.0%. Pyrolysis and petrographic data for the lower Atoka samples indicate mixed Type II/Type III organic matter, suggesting generated hydrocarbons may be both gas- and oil-prone. In all other samples, organic material is dominated by Type III organic matter (vitrinite), indicating that generated hydrocarbons should be gas-prone. Individual coal beds are thin at outcrop (< 1 m; 3.3 ft), laterally discontinuous, and moderately high in ash yield and sulfur content. A possible analog for coalbed gas potential in the Pennsylvanian section of north-central Texas occurs on the northeast Oklahoma shelf and in the Cherokee basin of southeastern Kansas, where contemporaneous gas-producing coal beds are similar in thickness, quality, and rank.     

Analysis of bycatch in the South African midwater trawl fishery for horse mackerel Trachurus capensis based on observer data

The South African midwater trawl fishery targets adult horse mackerel Trachurus capensis. The bulk of the catch is taken by a single freezer-trawler, the biggest fishing vessel operating in South African waters. As fishing takes place off the south coast in ecologically sensitive areas, there are concerns about the potential impacts of this fishing operation on non-target species. Fishing behaviour and bycatch of this fishery from 2004 to 2014 were investigated by analysing observer records with regard to catch composition, volume and temporal and spatial patterns. The midwater trawl fishery was estimated to have caught 25 415 tonnes annually, with a bycatch of 6.9% of the total catch, by weight. There are species overlaps with various fisheries, namely the demersal trawl, small-pelagic, line, shark longline and squid fisheries, yet the total bycatch estimates from this fishery are generally small relative to catches taken in the target fisheries. Bycatch species with the highest average annual catches were chub mackerel Scomber japonicus, redeye roundherring Etrumeus whiteheadi, ribbonfish Lepidopus caudatus and hake Merluccius spp. Large-fauna bycatch species included sunfish Mola mola as well as a number of CITES II- and IUCN-listed species, such as Cape fur seal Arctocephalus pusillus, dusky shark Carcharhinus obscurus, smooth hammerhead shark Sphyrna zygaena and thresher sharks Alopias spp. The 97.9% observer coverage is high and the 6.9% bycatch rate low compared to other South African fisheries; however, due to the large size of the individual hauls (average of 46.3 t), the average sampling rate of 1.56% is low. Our analyses suggest that bycatch in the South African midwater trawl fishery has been lower than in other South African fisheries and similar fisheries elsewhere, but due to the combination of high catch volumes and low sampling rates, estimation errors for rare species are high and there is a substantial risk of incidental unmonitored bycatch of rare large fauna and aggregations of small fauna. This could be mitigated by spatio-temporal management of this fishery, to avoid fishing in high-risk areas, and the introduction of an electronic monitoring programme.     

The impact of health financing and CO<Subscript>2</Subscript> emission on health outcomes in Sub-Saharan Africa: A cross-country analysis

The current paper examines the relationship between health financing (public and out-of-pocket health financing), CO₂ emission and health outcomes in 35 Sub-Saharan African countries for the period of 1995–2012. The panel unit root and cointegration tests are conducted as pre-tests, followed by the estimation of the parameters using the FM-OLS and DOLS techniques. The findings of the study show the importance of public health financing as one of the major factors that lead to better health outcomes, whereas the out-of-pocket expenditure is found to be harmful to population health since it leads to increase under-5 mortality rate. Although the results show a negative relationship between CO₂ and health outcomes, still these results remain inclusive. In addition, the findings reveal the importance of socioeconomic factors such as income and education as key determinants of health outcomes.     

Fishing and Farming at Lake Chad: Responses to Lake-level Fluctuations

Lake Chad lies at the southern extreme of the Sahara Desert and is well known for large fluctuations in its surface area this century. Seasonal fluctuations, however, have received much less attention. This paper presents the results of two complimentary research efforts on the south-west shore of the lake. These illustrate how important both inter and intra-annual fluctuations in the level of the lake are, both in terms of their impact on the environment and in the response of the communities living on the lake shore. The paper compares a time series of the fluctuations in the level of Lake Chad as monitored by the TOPEX/POSEIDON satellite with findings from participatory research with the communities of the south-west lake shore. It shows how the communities of the lake have responded to lake-level fluctuations with their livelihood choices. These results are used to show that although vastly different in scope, a high degree of complimentarity exists between remotely-sensed information and community-based research and that they are of potentially great value to development initiatives on the shores of Lake Chad.     

Community ecology of the metazoan parasites of snoek Thyrsites atun (Euphrasen, 1791) (Perciformes: Gempylidae) off South Africa

The parasite assemblage of snoek Thyrsites atun, a commercially important fish in the Benguela system, was examined over a one-year period. In all, 16 parasite taxa including eight new host records (Bolbosoma vasculosum, Caligus coryphaenae, Caligus dakari, Corynosoma australe, Hatschekia conifera, Nothobomolochus fradei, Rhadinorhynchus cadenati, Tentacularia coryphaenae) and four new locality records (B. vasculosum, C. dakari, Molicola uncinatus, Pseudoterranova sp.) were recovered from 210 specimens. The dominance of larval helminths in the component community suggests that T. atun occupies an intermediate position in the food web. The ‘nestedness metric based on overlap and decreasing fill’ (NODF) indicated that the parasite assemblage exhibited no nestedness (NODF = 73.3, p = 0.103). Generalised additive mixed modelling results indicated that host length is the main determinant of parasite species richness in T. atun. PERMANOVA and ANOSIM suggested that infracommunity structure varied little with respect to the sex, length, seasonality and capture region of the host. The stability and randomness in parasite acquisition, as indicated by the lack of nestedness of the parasite assemblage, can be ascribed to the opportunistic feeding behaviour and nomadic movement of T. atun in the southern Benguela. The homogeneity of the community structure of long-lived endoparasites suggests that a single T. atun stock occurs off South Africa.