Food sources, behaviour, and distribution of hydrothermal vent shrimps at the Mid-Atlantic Ridge

Five species of bresilioid shrimp were investigated at seven hydrothermal sites on the Mid-Atlantic Ridge: Menez Gwen, Lucky Strike, Rainbow, Broken Spur, TAG, Snake Pit and Logatchev. Samples were prepared for analysis of stable isotopes, elemental composition and lipids. Shrimp behaviour was observed from the submersible ‘Alvin’ and in the laboratory aboard RV ‘Atlantis’. The distribution and zonation of the shrimp species was recorded. Juvenile shrimp of all species arrive at the vents carrying reserves of photosynthetic origin, built-up in the pelagic larval stages. These reserves are used while the shrimp metamorphose to the adult form and, in Rimicaris exoculata and Chorocaris chacei, while they develop epibiotic bacteria supporting structures, the modified mouthparts and the inside of the carapace. The main food of adult R. exoculata is filamentous bacteria that grow on these structures. The intermediate sizes of C. chacei also feed on such bacteria, but the final stage gets some food by scavenging or predation. Mirocaris species scavenge diverse sources; they are not trophically dependent on either R. exoculata or mussels. Adults of Alvinocaris markensis are predators of other vent animals, including R. exoculata. The dense swarms of R. exoculata, with their exosymbionts, can be compared to endosymbiont-containing animals such as Bathymodiolus and the vestimentiferan tube-worms of the Pacific vents. Such associations, whether endo- or ectosymbiotic, may be necessary for the development of flourishing communities at hydrothermal vents.

Neurobiological model of visuo-spatial cognition in young Williams Syndrome children: measures of dorsal-stream and frontal function

We examine hypotheses for the neural basis of the profile of visual cognition in young children with Williams syndrome (WS). These are: (a) that it is a consequence of anomalies in sensory visual processing; (b) that it is a deficit of the dorsal relative to the ventral cortical stream; (c) that it reflects deficit of frontal function, in particular of fronto-parietal interaction; (d) that it is related to impaired function in the right hemisphere relative to the left. The tests reported here are particularly relevant to (b) and (c). They form part of a more extensive programme of investigating visual, visuospatial, and cognitive function in large group of children with WS children, aged 8 months to 15 years. To compare performance across tests, avoiding floor and ceiling effects, we have measured performance in children with WS in terms of the ‘age equivalence’ for typically developing children. In this paper the relation between dorsal and ventral function was tested by motion and form coherence thresholds respectively. We confirm the presence of a subgroup of children with WS who perform particularly poorly on the motion (dorsal) task. However, such performance is also characteristic of normally developingchildren up to 5 years: thus the WS performance may reflect an overall persisting immaturity of visuospatial processing which is particularly evident in the dorsal stream. Looking at the performance on the global coherence tasks of the entire WS group, we find that there is also a subgroup who have both high form and motion coherence thresholds, relative to the performance of children of the same chronological age and verbal age on the BPVS, suggesting a more general global processing deficit. Frontal function was tested by a counterpointing task, ability to retrieve a ball from a ‘detour box’, and the Stroop-like ‘day-night’ task, all of which require inhibition of a familiar response. When considered in relation to overall development as indexed by vocabulary, the day-night task shows little specific impairment, the detour box shows a significant delay relative to controls, and the counterpointing task shows a marked and persistent deficit in many children. We conclude that frontal control processes show most impairment in WS when they are associated with spatially directed responses, reflecting a deficit of fronto-parietal processing. However, children with WS may successfully reduce the effect of this impairment by verbally mediated strategies. On all these tasks we find a range of difficulties across individual children and a small subset of WS who show very good performance, equivalent to chronological age norms of typically developing children. Neurobiological models of visuo-spatial cognition in children with WS p.4 Overall, we conclude that children with WS have specific processing difficulties with tasks involving frontoparietal circuits within the spatial domain. However, some children with WS can achieve similar performance to typically developing children on some tasks involving the dorsal stream, although the strategies and processing may be different in the two groups.

Mathematical prerequisites for learning statistics in Psychology: Assessing core skills of numeracy and mathematical reasoning among undergraduates.

This study sought to extend earlier work by Mulhern and Wylie (2004) to investigate a UK-wide sample of psychology undergraduates. A total of 890 participants from eight universities across the UK were tested on six broadly defined components of mathematical thinking relevant to the teaching of statistics in psychology - calculation, algebraic reasoning, graphical interpretation, proportionality and ratio, probability and sampling, and estimation. Results were consistent with Mulhern and Wylie's (2004) previously reported findings. Overall, participants across institutions exhibited marked deficiencies in many aspects of mathematical thinking. Results also revealed significant gender differences on calculation, proportionality and ratio, and estimation. Level of qualification in mathematics was found to predict overall performance. Analysis of the nature and content of errors revealed consistent patterns of misconceptions in core mathematical knowledge , likely to hamper the learning of statistics.

An Investigation into the Link between UK Credit Union Characterisitics, Location and their Success

The unique characteristics of credit unions reduces the information asymmetry that is prevalent in credit making decisions, enabling them to provide loans where other financial institutions cannot. This makes them a potential tool in the fight against financial exclusion. Yet, the UK credit union movement is not regarded as being successful, even though there is evidence of much financial exclusion. This study is cross sectional in form, and evaluates characteristics that may contribute to the success of the UK credit union movement at national and regional level, in 2000. The findings are used to consider the impact of recent regulatory changes on the movement. The key findings are that there is a significant relationship between the success of a credit union, its size and the deprivation of the ward from which it sources its members. More specifically, larger credit unions and those located in more affluent wards, are more successful. Affiliation to the Irish League of Credit Unions and having a common bond of occupation, are also found to be contributing factors to credit union success. These results are taken as providing support for the recent changes implemented by the Financial Services Authority (FSA), which is likely to result in the emergence of larger credit unions (through mergers), run by appropriately qualified persons, serving a more mixed-income membership base. It is, however, noted that the history of the UK movement is one of missed opportunities and only time will tell whether credit unions have the wherewithal to accept current opportunities.

Self-focusing and envelope pulse generation in nonlinear magnetic metamaterials

The self-modulation of waves propagating in nonlinear magnetic metamaterials is investigated. Considering the propagation of a modulated amplitude magnetic field in such a medium, we show that the self-modulation of the carrier wave leads to a spontaneous energy localization via the generation of localized envelope structures (envelope solitons), whose form and properties are discussed. These results are also supported by numerical calculations.

Understandings of citizenship education in Northern Ireland and the Republic of Ireland: Public discourses among stakeholders in the public and private sectors

Internationally, citizenship education has come to the fore in the past decade. It may be particularly importantwithin the context of societies with a legacy of political conflict, such as Northern Ireland and the Republic of Ireland, where it is being implemented as part of the statutory curriculum. This article explores understandingsof citizenship education among stakeholders in the private and public sectors in Northern Ireland and the Republic of Ireland with the aim to compare these with curricular conceptualizations of citizenship inboth contexts. Semi-structured interviews were conducted in both societies involving non-governmentalorganizations, political parties, trade unions and the police. Results indicated that levels of awareness aboutcitizenship education varied substantially and understandings mainly reflected current theory and curriculumpractice in citizenship. Commonalities emerged as in both societies similar key concepts were identified whiledifferences transpired over issues relating to national identity and political conflict, which may raise questionsfor history and citizenship education in both societies.

Analysis of UDP-galactose 4'-epimerase mutations associated with the intermediate form of type III galactosaemia

Type III galactosaemia is a hereditary disease caused by reduced activity in the Leloir pathway enzyme, UDP-galactose 4'-epimerase (GALE). Traditionally, the condition has been divided into two forms-a mild, or peripheral, form and a severe, or generalized, form. Recently it has become apparent that there are disease states which are intermediate between these two extremes. Three mutations associated with this intermediate form (S81R, T150M and P293L) were analysed for their kinetic and structural properties in vitro and their effects on galactose-sensitivity of Saccharomyces cerevisiae cells that were deleted for the yeast GALE homologue Gal10p. All three mutations result in impairment of the kinetic parameters (principally the turnover number, k(cat)) compared with the wild-type enzyme. However, the degree of impairment was mild compared with that seen with the mutation (V94M) associated with the generalized form of epimerase deficiency galactosaemia. None of the three mutations tested affected the ability of the protein to dimerize in solution or its susceptibility to limited proteolysis in vitro. Finally, in the yeast model, each of the mutated patient alleles was able to complement the galactose-sensitivity of gal10 Delta cells as fully as was the wild-type human allele. Furthermore, there was no difference from control in metabolite profile following galactose exposure for any of these strains. Thus we conclude that the subtle biochemical and metabolic abnormalities detected in patients expressing these GALE alleles likely reflect, at least in part, the reduced enzymatic activity of the encoded GALE proteins.

Forma y transgresión: el discurso del arte

El arte, en sus diferentes campos, desarrolla un tipo de discurso que nada tiene que ver con el de otros ámbitos. Se vale de combinaciones de elementos diversos, normalmente pertenecientes a lenguajes convencionales, para elaborar un enunciado único y nuevo, donde una idea encuentra finalmente su forma. El contenido y la estructura se fusionan en un punto indisoluble. En este artículo se plantean las búsquedas de paradigmas clásicos de la forma artística y una reflexión al respecto desde el ámbito de las Artes Visuales. Se parte de la consideración que durante muchos siglos se tenía de la representación o imitación de la realidad no solo como vehículo de la expresión sino como la finalidad del arte. Se continua por el foco que la Transgresión de Dadá estableció en aquellas formas artísticas que buscan una conmoción emocional para que la creación alcance los territorios íntimos del receptor. Por último, se explica el fundamental hallazgo de Duchamp de señalar que es el propio discurso de la obra el que proporciona un nuevo pensamiento al mundo.

Teaching stylistics: analysing cohesion and narrative structure in a short story by Ernest Hemingway

The main aim of this article is to propose an exercise in stylistic analysis which can be employed in the teaching of English language. It details the design and results of a workshop activity on narrative carried out with undergraduates in a university department of English. The methods proposed are intended to enable students to obtain insights into aspects of cohesion and narrative structure; insights, it is suggested, which are not as readily obtainable through more traditional techniques of stylistic analysis. The text chosen for analysis is a short story by Ernest Hemingway comprising only 11 sentences. A jumbled version of this story is presented to students who are asked to assemble a cohesive and well-formed version of the story. Their (re)constructions are then compared with the original Hemingway version. Much interest, it is argued, lies in the ways in which the students justify their own versions in terms of their expectations about well-formedness in narrative. The activity is also intended to encourage students to see literary texts as a valuable means of providing insights into the subtleties of linguistic form and function.

Coalitional Games and Contracts Based on Individual Deviations

We study what coalitions form and how the members of each coalition split the coalition value in coalitional games in which only individual deviations are allowed. In this context we employ three stability notions: individual, contractual, and compensational stability. These notions differ in terms of the underlying contractual assumptions. We characterize the coalitional games in which individually stable outcomes exist by means of the top-partition property. Furthermore, we show that any coalition structure of maximum social worth is both contractually and compensationally stable.

National attachment and patriotism in a European nation: A British study

This study explores identification with one's national group using two distinct but interrelated concepts: identity content and relational orientation. Theoretical distinctions were drawn between two forms of identity content: traditional-cultural and civic, and between two forms of relational orientation: blind and constructive. The multidimensionality of both identity content and relational orientation and the relationships amongst these components were examined in a British sample: positive relationships were hypothesized between blind orientation and traditional-cultural content and between constructive orientation and civic content. Principal components analyses confirmed the hypothesized factor structures, and the resulting scales were highly reliable. Relationships amongst the resulting factors were explored using regression analyses. The overall results indicate support for the orthogonality of both the two orientation dimensions and the two content dimensions. Moreover, the hypothesized relationships between forms of orientation and content were largely supported. In conclusion, this study highlights the importance of looking at the relationship between identity content and relational orientation. The implications of these observations for theory and research are discussed with reference to using categories to

Thermodynamic properties and atomistic structure of the dry amorphous silica surface from a reactive force field model

A force field model of the Keating type supplemented by rules to break, form, and interchange bonds is applied to investigate thermodynamic and structural properties of the amorphous SiO2 surface. A simulated quench from the liquid phase has been carried out for a silica sample made of 3888 silicon and 7776 oxygen atoms arranged on a slab similar to 40 angstrom thick, periodically repeated along two directions. The quench results into an amorphous sample, exposing two parallel square surfaces of similar to 42 nm(2) area each. Thermal averages computed during the quench allow us to determine the surface thermodynamic properties as a function of temperature. The surface tension turns out to be gamma=310 +/- 20 erg/cm(2) at room temperature and gamma=270 +/- 30 at T=2000 K, in fair agreement with available experimental estimates. The entropy contribution Ts-s to the surface tension is relatively low at all temperatures, representing at most similar to 20% of the surface energy. Almost without exceptions, Si atoms are fourfold coordinated and oxygen atoms are twofold coordinated. Twofold and threefold rings appear only at low concentration and are preferentially found in proximity of the surface. Above the glass temperature T-g=1660 +/- 50 K, the mobility of surface atoms is, as expected, slightly higher than that of bulk atoms. The computation of the height-height correlation function shows that the silica surface is rough in the equilibrium and undercooled liquid phase, becoming smooth below the glass temperature T-g.