The hyoid arch and braincase anatomy of Acanthodes support chondrichthyan affinity of ‘acanthodians’

Solving the evolutionary relationships of the acanthodians is one of the key problems in reconstructing ancestral anatomical conditions for the jawed vertebrates (gnathostomes). Current debate concerns whether acanthodians are an assemblage of stem chondrichthyans, or a more generalized grade encompassing some early stem osteichthyans. The skull anatomy of Acanthodes bronni has been pivotal in these debates, owing to tension between chondrichthyan- and osteichthyan-like models of reconstruction. We use computed tomography scanning and traditional palaeontological techniques to resolve the long-standing debate about the anatomy of the jaw suspension. We establish the correct length of the hyomandibula and show that it attaches to a process on the ventrolateral angle of the braincase below the jugular vein groove. This condition corresponds precisely to that in chondrichthyans. This character represents an unambiguously optimized synapomorphy with chondrichthyans given current gnathostome phylogenies, corroborating the growing consensus of the chondrichthyan affinity of acanthodians.     

Leaf anatomy and water loss of in vitro PEG-treated ‘Valiant’ grape

Polyethylene glycol was used to induce water stress of micropropagated Valiant grape. Reduced growth and slow rooting were observed in treated plantlets with 2, 4 and 6% polyethylene glycol as compared to control plantlets with no polyethylene glycol in the rooting medium. At high concentrations of 4 and 6%, leaves exhibited wilting and necrosis. At the 2% level, plantlets recovered and grew satisfactorily. Detached leaves of treated plantlets with 2% polyethylene glycol lost less water than controls when exposed to low humidity for 4 hours. Leaf anatomy of plantlets treated with 2% polyethylene glycol, control (in vitro plantlets) and greenhouse-grown plants were compared under light microscopy. Leaves from control plantlets contained larger mesophyll cells, lacked normal palisade layer formation, had greater intercellular pore spaces and fewer chloroplasts. Leaves from polyethylene glycol-treated plantlets, however, had smaller mesophyll cells, a more defined palisade layer, reduced intercellular pore space and the greatest number of chloroplasts. These results suggest that an osmoticum such as polyethylene glycol may be used to induce more normal leaf anatomy and reduced water loss in micropropagated Valiant grapes.Abbreviations BA 6-benzylaminopurine - FAA formalin-acetol-alcohol - MS Murashige & Skoog (1962) medium - MW molecular weight - NAA napthaleneacetic acid - PEG polyethylene glycol - TBA tertiary butyl alcohol     

The imagination of ‘society’ in measurements of immigrant integration

Abstract

My aim in this contribution is to clarify in which way social scientific measurements of immigrant integration operate as a form of ‘social imagination’, that is, of the routinized and professionalized visualization of social life. Through such measurements, images of ‘society’ are produced that feed into larger social imaginaries. My discussion takes as an example Dutch discourse and research on integration. Crucial to the constitution of society in the Netherlands and many other Western European countries is what I call a culturist discourse that has many similarities to racism. This discourse demarcates the boundaries of society by rendering objectively observable the non-integrated who are considered to reside ‘outside society’. The image of society thereby produced is that of a morally cleansed realm: social problems are relegated to the domain ‘outside society’, consisting of persons in need of integration.     

The fate of ‘biodegradable’ plastics in municipal leaf compost

Summary Blends of starch with polypropylene, starch with polyethylene, polycaprolactone with polyethylene, and a copolymer of -hydroxybutyrate and -hydroxyvalerate (PHB/V) were exposed to degrading leaves in a municipal leaf composting operation. Every month for 6 months, duplicate samples were analyzed for changes in weight and tensile properties, and many of these samples were further analyzed for changes in molecular weight and surface morphology. All results were compared to controls which were incubated for 6 months in moist, sterile leaves at a leaf compost temperature. Very little change was noted for any of the polyolefin blends over the 6-month period. In contrast, PHB/V samples showed massive deterioration with substantial weight loss. Although there was a decrease in molecular weight and a loss of tensile properties in leaf-exposed PHB/V films, the sterile control films also showed similar changes, but without weight loss. Of the microbial isolates from film surfaces, only fungi possessed PHB/V depolymerase activity.     

The history of comparative anatomy in Jena — an overview

Summary Comparative anatomy and zoology both have long academic traditions in Jena. At first, the two subjects developed in parallel and had many similarites in research topics. This development is covered in the first part of the paper. The close relationship between the two subjects started to break apart when Carl Gegenbaur and Ernst Haeckel were active at Jena University. In 1865 Haeckel became the first full professor of zoology in Jena, and zoology became more independent from comparative anatomy. In the second part of our paper, we follow the developments in comparative anatomy in Jena from Gegenbaur’s immediate students up until the end of Hans B?ker’s tenure in Jena in the mid-1930s. Certain subjects are in focus throughout this period, for example vertebrate head morphology and development, (the “head problem”), the relationship between anatomy and biology, and evolutionary questions. Some of these subjects have remained important research topics in zoology and comparative anatomy in Jena until the present day.     

The ‘curse’ of Westermarck 1

This article consists of a critical application of recent theory of nationalism to the unusual case of Mauritius. It is a poly‐ethnic and poly‐religious society whose inhabitants neither share a mythical distant past nor consider themselves culturally identical, but where nation‐building has nevertheless been moderately successful since the late 1960s. Through an examination of the processes of institutional and cultural nation‐building in the island, it is argued that the current Eurocentric view of the nation (notably as a culturally homogeneous imagined community) must be modified to fit cases like this one. Thus, the value of nationalism and nationhood as comparative concepts is questioned.     

The message of ‘The Other North Sea’

This paper explains the objectives of organising the symposium ‘The Other North Sea’. A major goal is the submission of the conclusions and content of this symposium to the North Sea Task Force, an initiative of the Second Conference on the Protection of the North Sea (London, 1987) which is responsible for preparing a Quality Status Report on the North Sea by mid-1993. The conclusions and recommendations of the symposium are summarised and presented to the North Sea Task Force in connection with the preparations for the 1993 Quality Status Report. The paper stresses the need to subdivide the North Sea into areas of ecological entity and underlines the advantages of using diatom and meiofauna assemblages as indicators for present and past environmental actors in sediment conditions. A plea is also made for the promotion of research to improve understanding of disturbance of sensory perception and behaviour as an ecologically relevant early warning signal. The major role of fisheries in inducing changes of seabird and harbour porpoise populations is highlighted.     

The spectre of ‘spurious’ correlations

Summary Ecologists often standardize data through the use of ratios and indices. Such measures are employed generally to remove a size effect induced by some relatively uniteresting variable. The implications of using the resultant data in correlation and regression analyses are poorly recognized. We show that ratios and indices often provide surprising and spurious results due to their unusual properties. As a solution, we advocate the use of randomization tests to evaluate hypotheses confounded by spurious correlations. In addition, we emphasize that identifying the appropriate null correlation is of utmost importance when statistically evaluating ratios, although this issue is frequently ignored.     

The Meaning of ‘Self-Starvation’ in Impoverished Black Adolescents in South Africa

Recent surveys in South Africa have demonstrated that disordered eating is equally common among black and white female students. Self-report measures have been used in these surveys to establish levels of disordered eating. One study in Tanzania, where a two-stage design was implemented, showed that upon interview the majority of participants did not present with disordered eating. The absence of two-stage studies in South Africa brings into question some of the findings from these surveys. In the present study, we surveyed a sample of black and white high school students in South Africa to establish the prevalence of disordered eating. In the second phase of this study, we attempted to interview those black students from one particular school who scored high on the eating disorder measures. This process proved both challenging and elucidating. While a significant number of young black females endorsed eating disorder symptoms on self-report, interviews with some participants showed that self-starvation and related symptoms had a different meaning from what we would typically expect from someone with an eating disorder. Consequently, this study highlights the need to revisit the methods typically employed in cross-cultural research in eating disorders. Careful consideration of a variety of cultural factors that may alter the meaning of standard measures is called for.     

The Political Economy of ‘Trauma’ in Haiti in the Democratic Era of Insecurity

This article explores the challenges that emerge at the intersection of economies of compassion and terror: local, national, and international forms of humanitarian assistance; security practices in insecure social and institutional environments; questions of victimization and global reparations; and quests for justice, as revealed through an analysis of political violence and humanitarian interventions in Haiti during and after the 1991-94 coup period. Each domain is constrained by politics and history but can engender "occult economies" that challenge the intended consequences of restitution policies at international, national, and local levels of exchange. 'Trauma' and discourses about traumatic suffering are the hinge around which these economies pivot, generating new forms of political subjectivity for Haitian activists.     

The role of iron in the formation of Ediacaran ‘death masks’

The Ediacara biota are an enigmatic group of Neoproterozoic soft-bodied fossils that mark the first major radiation of complex eukaryotic and macroscopic life. These fossils are thought to have been preserved via pyritic “death masks” mediated by seafloor microbial mats, though little about the chemical constraints of this preservational pathway is known, in particular surrounding the role of bioavailable iron in death mask formation and preservational fidelity. In this study, we perform decay experiments on both diploblastic and triploblastic animals under a range of simulated sedimentary iron concentrations, in order to characterize the role of iron in the preservation of Ediacaran organisms. After 28 days of decay, we demonstrate the first convincing “death masks” produced under experimental laboratory conditions composed of iron sulfide and probable oxide veneers. Moreover, our results demonstrate that the abundance of iron in experiments is not the sole control on death mask formation, but also tissue histology and the availability of nucleation sites. This illustrates that Ediacaran preservation via microbial death masks need not be a “perfect storm” of paleoenvironmental porewater and sediment chemistry, but instead can occur under a range of conditions.     

‘It’s okay to be racist’: moral disengagement in online discussions of racist incidents in Australia

Racist views expressed on the Internet have damaging consequences for social harmony and well-being. This article examines how and why individuals express support or opposition to racist behaviour in a prominent online medium: comments on news websites. Specifically, we examine how supporters and opponents of racist behaviour use a particular type of subtle discursive strategies known as moral disengagement in their online responses to three notable racist incidents that occurred in Australia in 2013. Moral disengagement strategies allow individuals to avoid distress, self-condemnation, and social-sanctions when supporting or engaging in harmful behaviour by making that behaviour appear moral and acceptable. We show that supporters, but not opponents, of racist behaviour consistently use moral disengagement strategies in their rhetoric, and demonstrate that moral disengagement provides a powerful theoretical framework through which racist rhetoric on online news websites can be understood.