Benthic foraminifera: Their importance to future reef island resilience

The provenance, age and redistribution of sediments across Raine Reef (11°35’28”S 144°02’17”E), northern Great Barrier Reef (GBR) are described. Sediments of both the reef flat and sand cay beaches are composed predominantly of benthic foraminifera (35.2% and 41.5% respectively), which is a common occurrence throughout the Pacific region. The major contemporary sediment supply to the island was identified as Baculogypsina sphaerulata, a relatively large (1-2 mm exclusive of spines) benthic foraminifera living on the turf algae close to the reef periphery, and responsible for beach sand nourishment. Radiometric ages of foraminiferal tests of ranging taphonomic preservation (pristine to severely abraded) included in surficial sediments collected across the reef flat were remarkably young (typically <60 years). Results indicate rapid transport and/or breakdown of sand with a minimal storage time on the reef (likely <102 years), inferring a tight temporal link between the reef island and sediment production on the surrounding reef. This study demonstrates the critical need for further research on the precise residence times of the major reef sediment components and transport pathways, which are fundamental to predicting future island resilience. © Copyright belongs to the authors

Modelling and water yield assessment of Lake Sibhayi

This study has been undertaken to establish the probable causes of the almost 4 m drop in the level of Lake Sibhayi between 2001 and 2014, to assess the impact of abstractions for domestic water consumption and by commercial plantations on lake levels, and to determine what sustainable yield can be abstracted from Lake Sibhayi. From the analysis and simulations undertaken, it is concluded that the major cause of the drop in the level of Lake Sibhayi was the below-average rainfall over the period 2001 to 2011. However, while the simulation results show that the effect on lake levels of abstractions for domestic usage over this period has been negligible, they do indicate that nearly 1.4 m of the drop in lake level can be attributed to the impact of the afforestation which began in the catchment in the 1990s. A yield analysis of simulated results with historical developments in the catchment for the 65-year period of observed climate record was undertaken using both a fixed minimum allowable lake level or a maximum drop from a reference lake level as criteria for system failure. Results from simulating lake levels using the historical climate record with the area afforested and abstractions levels fixed at 2014 values indicate that no sustainable additional yield is possible because of the sustained decline in both the simulated lake levels and conceptual groundwater store, which would be environmentally, socially and ecologically unacceptable. Preliminary simulated results indicate that the removal of approximately 5 km2 of forestry is required to release 1 MCM/yr for domestic abstractions. However, these preliminary results require improved verification of input data and a review of the modelling for increased confidence in the results.Keywords: hydrology of Lake Sibhayi, lake level, abstractions, afforestation and yiel

Syk tyrosine kinase is critical for B cell antibody responses and memory B cell survival

Signals from the BCR are required for Ag-specific B cell recruitment into the immune response. Binding of Ag to the BCR induces phosphorylation of immune receptor tyrosine-based activation motifs in the cytoplasmic domains of the CD79a and CD79b signaling subunits, which subsequently bind and activate the Syk protein tyrosine kinase. Earlier work with the DT40 chicken B cell leukemia cell line showed that Syk was required to transduce BCR signals to proximal activation events, suggesting that Syk also plays an important role in the activation and differentiation of primary B cells during an immune response. In this study, we show that Syk-deficient primary mouse B cells have a severe defect in BCR-induced activation, proliferation, and survival. Furthermore, we demonstrate that Syk is required for both T-dependent and T-independent Ab responses, and that this requirement is B cell intrinsic. In the absence of Syk, Ag fails to induce differentiation of naive B cells into germinal center B cells and plasma cells. Finally, we show that the survival of existing memory B cells is dependent on Syk. These experiments demonstrate that Syk plays a critical role in multiple aspects of B cell Ab responses

Education Can Compensate for Society - a Bit

In this paper I reflect on the findings of a number of loosely related research projects undertaken with colleagues over the last ten years. Their common theme is equity, in formal education and beyond, in wider family and social settings, and with inequity expressed as the stratification of a variety of educational outcomes. The projects are based on a standard mixture of pre-existing records, official documents, large-scale surveys, observations, interviews and focus groups. The numeric data were largely used to create biographical models of educational experiences, and the in-depth data were used to try to explain individual decisions and disparities at each stage of the model. Data have been collected for England and Wales, in five other countries of the European Union and for Japan. A meta-view of these various findings suggests that national school intakes tend to be at least moderately segregated by prior attainment and socio-economic factors, and that learning outcomes as assessed by formal means, such as examinations, are heavily stratified by these same factors. There is no convincing evidence that compulsory schooling does very much to overcome the initial disparity in the resources and attainment of school intakes. On the other hand, there are indications that the nature of a national school system and the social experiences of young people in schools can begin to equalise educational outcomes as more widely envisaged, including learning to trust and willingness to help others, aspirations, and attitudes to continuing in education and training. The cost-free implications of the argument in this paper, if accepted, are that everything possible should be done to make school intakes comprehensive, and that explicit consideration, by teachers and leaders, of the applied principles of equity could reduce potentially harmful misunderstandings in educational contexts

Strain-induced shape transition of VSi₂ clusters on Si(111)

We investigated the growth and shape of vanadium silicide clusters on Si(111) using scanning tunneling microscopy, atomic force microscopy and scanning electron microscopy. The deposition of 8 monolayers of vanadium on Si(111) and subsequent annealing at 1200 K leads to the formation of large elongated VSi2 clusters. This is in marked contrast to the deposition of submonolayer amounts of V where the VSi2 islands have a compact shape. The shape transition can be explained by a competition between edge formation and strain relaxation energy terms. The VSi2 clusters, which are aligned along the three high symmetry directions of the Si(111) surface and surrounded by a denuded zone, form a two-dimensional network.</p

Schistosoma mansoni: importance of skin and pulmonary phases to concomitant immunity in albino mice

Fourteen-day-old schistosomula obtained from mice previously infected were surgically transferred to the portal vein of receptor mice. Another group of mice was infected with cercariae by transcutaneous route. After 90 days, those groups were challenged with 100 cercariae, transcutaneously, as well as a control group. Two weeks later the animals were perfused and mature and immature worms counted separately. Statistically significant differences were observed in the recovery of immature worms, when the control group was compared with those twice infected. No statistical difference was detected between the group infected transcutaneously, and that infected by worm inoculation in portal vein. Results demonstrated that suppression of skin and lung migration of the parasite does not interfere with the development of the so called concomitant immunity

Micronutrients: highlights and research challenges from the 1994-5 National Diet and Nutrition Survey of people aged 65 years and over

The aims of the National Diet and Nutrition Survey series are summarized, and the new National Diet and Nutrition Survey of people aged 65 years and over is explored, with particular emphasis on micronutrient intakes and status indices. Mean nutrient intakes were generally satisfactory for most micronutrients, but intakes of vitamin D, Mg, K and Cu were low. Intakes of vitamin D were far below the reference nutrient intake for people aged 65 years and over, and there was also biochemical evidence of vitamin D deficiency, for 8% of free-living and 37% of institution participants, attributed partly to limited exposure to sunlight. A substantial proportion of people living in institutions had inadequate biochemical status indices, notably for vitamin C, Fe and folate. Relationships between intake and status were close for vitamins. Mineral intakes did not correlate well with currently used status indices. Some intakes and indices, especially those of vitamin C, carotenoids, Na and K, were strongly correlated with socio-economic status and with north-south gradients in Britain. Future research challenges should address the functional and health significance of low intakes and sub-optimal biochemical indices for certain micronutrients, especially for people living in institutions; the shortcomings of mineral status indices especially as indicators of mineral intake; the social and geographical inequalities of micronutrient intakes and status, and why micronutrient status deteriorates with increasing age. The answers to these questions will help to define the characteristics of nutritional risk for older people in Britain, and to clarify future needs for education and intervention