Swinburne in Miniature

This article describes John Mayfield\u27s acquisition of a rare notebook written by English poet A.C. Swinburne, which contains unpublished poetry that was later used in a miniature book publication

Molecular Factors Affecting the Accumulation of Recombinant Proteins in the Chlamydomonas reinhardtii Chloroplast

In an effort to develop microalgae as a robust system for the production of valuable proteins, we analyzed some of the factors affecting recombinant protein expression in the chloroplast of the green alga Chlamydomonas reinhardtii. We monitored mRNA accumulation, protein synthesis, and protein turnover for three codon-optimized transgenes including GFP, bacterial luciferase, and a large single chain antibody. GFP and luciferase proteins were quite stable, while the antibody was less so. Measurements of protein synthesis, in contrast, clearly showed that translation of the three chimeric mRNAs was greatly reduced when compared to endogenous mRNAs under control of the same atpA promoter/UTR. Only in a few conditions this could be explained by limited mRNA availability since, in most cases, recombinant mRNAs accumulated quite well when compared to the atpA mRNA. In vitro toeprint and in vivo polysome analyses suggest that reduced ribosome association might contribute to limited translational efficiency. However, when recombinant polysome levels and protein synthesis are analyzed as a whole, it becomes clear that other steps, such as inefficient protein elongation, are likely to have a considerable impact. Taken together, our results point to translation as the main step limiting the expression of heterologous proteins in the C. reinhardtii chloroplast

A nonlinear land use regression approach for modelling NO2 concentrations in urban areas—Using data from low-cost sensors and diffusion tubes

Land Use Regression (LUR) based on multiple linear regression model is one of the techniques used most frequently for modelling the spatial variability of air pollution and assessing exposure in urban areas. In this paper, a nonlinear generalised additive model is proposed for LUR and its performance is compared to a linear model in Sheffield, UK for the year 2019. Pollution models were estimated using NO2 measurements obtained from 188 diffusion tubes and 40 low-cost sensors. Performance of the models was assessed by calculating several statistical metrics including correlation coefficient (R) and root mean square error (RMSE). High resolution (100 m × 100 m) maps demonstrated higher levels of NO2 in the city centre, eastern side of the city and on major roads. The results showed that the nonlinear model outperformed the linear counterpart and that the model estimated using NO2 data from diffusion tubes outperformed the models using data from low-cost sensors or both low-cost sensors and diffusion tubes. The proposed method provides a basis for further application of advanced nonlinear modelling approaches to constructing LUR models in urban areas which enable quantifying small scale variability in pollution levels

Diet of the west coast rock lobster Jasus Lalandii: Influence of lobster size, sex, capture depth, latitude and moult stage

Diets of male and female West Coast rock lobster Jasus lalandii in South Africa were compared across a large size range of 10–85 mm carapace length (CL). The diets of male rock lobsters were compared betweentwo different depths, different seasons, across the moult cycle, and among eight sites along the South-Western Cape coast. There was no significant difference in diet between male and female rock lobsters for any of thesize-classes examined. Male rock lobsters showed large differences in diet between small and large size-classes. The diet of small lobsters (80mm CL) fed on few species, and fish and ribbed mussels were their most abundant prey items. There were some dietary differences between individuals captured at 20 m and those collected at 50 m, but these differences were less marked than between the two sampling sites (the Knol and Olifantsbos). There was seasonal variation in diet at the Dassen Island and Olifantsbos sites. Cannibalism was highest during the moulting periods. Gut fullness varied seasonally at Dassen Island, and was consistently high at Olifantsbos. However, the proportion of the population feeding showed marked seasonal trends at both sites, tracking the commercial catch per unit effort of rock lobster. Ribbed mussels were a ubiquitous and dominant component of the diet at the eight sites sampled. However, south of Dassen Island, black mussels Choromytilus meridionalis were scarce in the diet of rock lobster and sponges predominated. Gut fullness was lowest at the northernmostsites

The potential for using acoustic tracking to monitor the movement of the West Coast rock lobster Jasus lalandii

Although acoustic tracking has been used to study the movement of several species of clawed and spiny lobsters, only recent technological advances have provided sufficiently small transmitters to examine the utility of using acoustic tracking as a means to analyse the movement of relatively small spiny lobsters, such as Jasus lalandii. The effect of the transmitter on the mobility of J. lalandii was tested in aquarium experiments and was shown to have no influence on movement in three separate experiments. Thereafter, adult male rock lobsters (86–98mm carapace length) were tracked in field trials for up to 32 days at Betty's Bay (n = 4) and Hermanus (n = 5) off the Western Cape, South Africa. Tracking J. lalandii in the field using acoustic tags was successful, even in areas with dense kelp beds and rocky outcrops. The signal from the transmitters was readily detectable from the surface and subsequent use of underwater tracking equipment enabled visual confirmation of the position of the rock lobsters. Lobsters moved significantly longer distances (>45m day−1) in the first two days following tagging than during any subsequent time period (<10m day−1). This suggests that transmitter attachment and/or handling altered the movement pattern for the first 72 hours after tagging. During the period of observation, J. lalandii displayed classical nomadic behaviour

AQUARIUM EXPERIMENTS COMPARING THE FEEDING BEHAVIOUR OF ROCK LOBSTER JASUS LALANDII ON ABALONE AND SEA URCHINS AT TWO SITES ON THE WEST COAST OF SOUTH AFRICA

Predation by the rock lobster Jasus lalandii is influential in regulating the composition of shallow-reef communities on the west coast of South Africa. Two previous and independent studies addressing this topic, but conducted 600 km apart (one in Cape Town and the other in Port Nolloth on the west coast of South Africa) and using different experimental protocols, revealed contradictory results regarding the feeding behaviour of J. lalandii. The Port Nolloth study showed that juvenile abalone Haliotis midae hiding under sea urchins Parechinus angulosus were safe from predation by rock lobsters, which seemed to prefer the sea urchins as food. However, the Cape Town study showed that rock lobsters preferentially selected juvenile abalone over sea urchins. Because of the importance of these results to abalone ranching and the South African abalone fishery, the experiments were repeated at the two study sites, using a standardized experimental protocol. Rock lobsters from both sites showed a strong preference for juvenile abalone over sea urchins, even in the presence of kelp Ecklonia maxima. There was no significant difference (F3.92 = 0.09, p &#62 0.1) in abalone consumption by rock lobsters between the two sites. Therefore, at least in the absence of preferred prey such as mussels, sea urchins appear to provide only limited protection to juvenile abalone from rock lobsters.Afr. J. mar. Sci. 25: 377–38

Predation by West Coast rock lobsters (Jasus lalandii) on two species of winkle (Oxystele sinensis and Turbo cidaris)

Rock lobsters, Jasus lalandii, may play an important role in structuring the communities on shallow reef ecosystems and have recently increased in density in the area between Cape Hangklip and Danger Point on the southwest coast of South Africa. This has probably resulted in increased predation on natural populations of smooth turban shells (Turbo cidaris) and pink-lipped topshells (Oxystete sinensis), both of which are proposed targets for small-scale commercial fisheries. This study examines the size selectivity, prey species preferences and consumption rates of rock lobsters feeding on these two winkle species. Rock lobsters showed a strong preference for small O. sinensis, and were limited to taking a maximum (or critical) size of prey, which increased linearly with rock-lobster size. By contrast, rock lobsters of all size classes tested were able to crack and consume a full size range of T. cidaris, and no size preferences were evident. When the two gastropods were offered simultaneously, rock lobsters preferentially consumed the thinner shelled O. sinensis.Consumption rates increased linearly with rock-lobster size. Population consumption rates indicate that rock lobsters will have a profound effect on winkle stocks in the area, even if winkles constituted less than 1% of the diet. This in turn suggests that commercial exploitation of these stocks is unlikely to remain sustainable

Postscriptum

John S. Mayfield fleshes out the discovery of a hiterto unknown description of the English poet Swinburne written by Ambrose Bierce. It was discovered by Professor Grenander. Although Swinburne\u27s life is already well chronicled, the new discovery adds an amusing aside from a satirical master