Origin and significance of 'dispersed facies' basal ice: Svínafellsjökull, Iceland

Dispersed facies basal ice - massive (i.e. structureless) ice with dispersed debris aggregates - is present at the margins of many glaciers and, as a product of internal glacial processes, has the potential to provide important information about the mechanisms of glacier flow and the nature of the subglacial environment. The origin of dispersed facies is poorly understood, with several hypotheses having been advanced for its formation, and there is disagreement as to whether it is largely a sedimentary or a tectonic feature. We test these established hypotheses at the temperate glacier Svfnafellsjokull, Iceland, and find that none fully account for dispersed facies characteristics at this location. Instead, dispersed facies physical, sedimentological and stable-isotope (5180, 8D) characteristics favour a predominantly tectonic origin that we suggest comprises the regelation and straininduced metamorphism of debris-rich basal ice that has been entrained into an englacial position by tectonic processes operating at the base of an icefall. Further thickening of the resultant dispersed facies may also occur tectonically as a result of ice flow against the reverse bed slope of a terminal overdeepening. Lack of efficient subglacial drainage in the region of the overdeepening may limit basal melting and thus favour basal ice preservation, including the preservation of dispersed facies. Despite the relatively low sediment content of dispersed facies (~1.6% by volume), its thickness (up to 25 m) and ubiquity at Svfnafellsjokull results in a significant contribution to annual sediment discharge (1635-3270 m3 a"1) that is ~6.5 times that contributed by debris-rich stratified facies basal ice

Lag effects in the impacts of mass coral bleaching on coral reef fish, fisheries, and ecosystems

Recent episodes of coral bleaching have led to wide-scale loss of reef corals and raised concerns over the effectiveness of existing conservation and management efforts. The 1998 bleaching event was most severe in the western Indian Ocean, where coral declined by up to 90% in some locations. Using fisheries-independent data, we assessed the long-term impacts of this event on fishery target species in the Seychelles, the overall size structure of the fish assemblage, and the effectiveness of two marine protected areas (MPAs) in protecting fish communities. The biomass of fished species above the size retained in fish traps changed little between 1994 and 2005, indicating no current effect on fishery yields. Biomass remained higher in MPAs, indicating they were effective in protecting fish stocks. Nevertheless, the size structure of the fish communities, as described with size-spectra analysis, changed in both fished areas and MPAs, with a decline in smaller fish (<30 cm) and an increase in larger fish (>45 cm). We believe this represents a time-lag response to a reduction in reef structural complexity brought about because fishes are being lost through natural mortality and fishing, and are not being replaced by juveniles. This effect is expected to be greater in terms of fisheries productivity and, because congruent patterns are observed for herbivores, suggests that MPAs do not offer coral reefs long-term resilience to bleaching events. Corallivores and planktivores declined strikingly in abundance, particularly in MPAs, and this decline was associated with a similar pattern of decline in their preferred corals. We suggest that climate-mediated disturbances, such as coral bleaching, be at the fore of conservation planning for coral reefs.\u

Perceptions of trends in Seychelles artisanal trap fisheries: comparing catch monitoring, underwater visual census and fishers' knowledge

Fisheries scientists and managers are increasingly engaging with fishers' knowledge (FK) to provide novel information and improve the legitimacy of fisheries governance. Disputes between the perceptions of fishers and scientists can generate conflicts for governance, but can also be a source of new perspectives or understandings. This paper compares artisanal trap fishers' reported current catch rates with landings data and underwater visual census (UVC). Fishers' reports of contemporary 'normal' catch per day tended to be higher than recent median landings records. However, fishers' reports of 'normal' catch per trap were not significantly different from the median CPUE calculated from landings data, and reports of 'good' and 'poor' catch rates were indicative of variability observed in landings data. FK, landings and UVC data all gave different perspectives of trends over a ten-year period. Fishers' perceptions indicated greater declines than statistical models fitted to landings data, while UVC evidence for trends varied between sites and according to the fish assemblage considered. Divergence in trend perceptions may have resulted from differences in the spatial, temporal or taxonomic focus of each dataset. Fishers may have experienced and understood behavioural changes and increased fishing power, which may have obscured declines from landings data. Various psychological factors affect memory and recall, and may have affected these memory-based estimates of trends, while different assumptions underlying the analysis of both interview data and conventional scientific data could also have led to qualitatively different trend perceptions. Differing perspectives from these three data sources illustrate both the potential for 'cognitive conflicts' between stakeholders who do not rely on the same data sources, as well as the importance of multiple information sources to understand dynamics of fisheries. Collaborative investigation of such divergence may facilitate learning and improve fisheries governance

The zebrafish xenograft platform-A novel tool for modeling KSHV-associated diseases

Kaposi\u27s sarcoma associated-herpesvirus (KSHV, also known as human herpesvirus-8) is a gammaherpesvirus that establishes life-long infection in human B lymphocytes. KSHV infection is typically asymptomatic, but immunosuppression can predispose KSHV-infected individuals to primary effusion lymphoma (PEL); a malignancy driven by aberrant proliferation of latently infected B lymphocytes, and supported by pro-inflammatory cytokines and angiogenic factors produced by cells that succumb to lytic viral replication. Here, we report the development of the firs

3-dimensional Cauchy-Riemann structures and 2nd order ordinary differential equations

The equivalence problem for second order ODEs given modulo point transformations is solved in full analogy with the equivalence problem of nondegenerate 3-dimensional CR structures. This approach enables an analog of the Feffereman metrics to be defined. The conformal class of these (split signature) metrics is well defined by each point equivalence class of second order ODEs. Its conformal curvature is interpreted in terms of the basic point invariants of the corresponding class of ODEs

ナンキョク ケンキュウ カガク イインカイ ノ レンゾク プランクトン サイシュウキ センモンカ グループ ワークショップ ホウコク

2010年11月22-26日に国立極地研究所にて「南極研究科学委員会(以下SCAR)連続プランクトン採集器(以下CPR)専門家グループワークショップ」を開催した.4カ国から12名が参加し,南大洋CPR観測実務担当者の間で,観測データの品質管理,種同定やデータ分析手法の再確認,及び今後の活動についての詳細な討議を行った.前半は文献資料及び顕微鏡観察を通して,動物プランクトンの分類群ごとに種同定の情報交換及び具体的な分類カテゴリーの統一を図った.まとめられた種同定基準を用いて新たにマニュアルを作成することとなった.後半はデータ分析手法とデータマネージメント,さらには将来的な観測計画を確認した.今後,定期的にワークショップを開催し,各国間で統一された試料処理及びデータ管理を維持していくことで合意した."Southern Ocean Continuous Plankton Recorder (SO-CPR) Standards Workshop: SCAR Expert Group on CPR Research" was held at the National Institute of Polar Research (NIPR) on 22-26 November 2011. Twelve participants from four countries attended. The purposes of the workshop were to ensure that consistent and high standards of species identification, methodology, and data quality were being maintained amongst all participants and laboratories in the SO-CPR survey, and to discuss future contributions of the SO-CPR program to a global CPR network. The first three and a half days of the workshop were focused on assessing the accuracy and consistency of species identifications. We concluded that our species identifications and procedures are accurate and uniform, and that the SO-CPR database is of the highest possible standard. Certain taxonomic criteria developed at the workshop will be described in a new laboratory procedures manual. Four major gaps in the database (spatial, temporal, taxonomic, and data analysis gaps) were identified and discussed. Participants concurred that there should be more regular workshops to ensure that the high standards of the SO-CPR program are maintained

Governing the souls of young women: exploring the perspectives of mothers on parenting in the age of sexualisation

The sexualisation of young women has emerged as a growing concern within contemporary western cultures. This has provoked adult anxieties that young women are growing up too fast by adopting inappropriate sexual practices and subjectivies. Psychological discourses have dominated which position sexualisation as a corrupting force that infects the ‘true self’ of young women, so they develop in abnormal ways. This in turn allows psychological practices to govern how to parent against sexualisation within families. To explore this further, six mothers each with daughters aged between eight and twelve years old took part in one to one semi-structured interviews designed to explore how they conceptualised and parented against the early sexualisation of young women. A Foucauldian inspired discourse analysis was employed, which suggested that the mothers talk was situated within a psychological discourse. This enabled sexualisation to be positioned as a corrupting force that disrupted the natural development of young women through deviant bodily practices (e.g. consuming sexualised goods), which prevented them from becoming their ‘true self’. Through the disciplinary gaze of psychology, class inequalities were reproduced where working class families were construed as ‘chavs’ who were bad parents and a site of contagion for sexualisatio

X-raying the AU Microscopii debris disk

AU Mic is a young, nearby X-ray active M-dwarf with an edge-on debris disk. Debris disk are the successors of the gaseous disks usually surrounding pre-main sequence stars which form after the first few Myrs of their host stars' lifetime, when - presumably - also the planet formation takes place. Since X-ray transmission spectroscopy is sensitive to the chemical composition of the absorber, features in the stellar spectrum of AU Mic caused by its debris disk can in principle be detected. The upper limits we derive from our high resolution Chandra LETGS X-ray spectroscopy are on the same order as those from UV absorption measurements, consistent with the idea that AU Mic's debris disk possesses an inner hole with only a very low density of sub-micron sized grains or gas.Comment: 11 pages, 10 figures, accepted for publication in A&

Echo in Optical Lattices: Stimulated Revival of Breathing Oscillations

We analyze a stimulated revival (echo) effect for the breathing modes of the atomic oscillations in optical lattices. The effect arises from the dephasing due to the weak anharmonicity being partly reversed in time by means of additional parametric excitation of the optical lattice. The shape of the echo response is obtained by numerically simulating the equation of motion for the atoms with subsequent averaging over the thermal initial conditions. A qualitative analysis of the phenomenon shows that the suggested echo mechanism combines the features of both spin and phonon echoes.Comment: 13 pages, 3 figure