The SeaCoRe system for large scale kelp aquaculture: a plug-and-play,compatible, open-source system for the propagation and transport of clonal gametophyte cultures

Journal of Applied Phycology - The future of large-scale kelp aquaculture is standing at a crossroad, with the diverging paths being characterized by two fundamentally different cultivation methods...     

Photoacclimation of Scenedesmus protuberans (Chlorophyceae) to fluctuating irradiances simulating vertical mixing

Photoacclimation of Scenedesmus protuberans Fritsch to fluctuatingirradiances, simulating vertical mixing, was studied in light-limitedcontinuous cultures. The algae were exposed to a simple sinusoidallight regime simulating diumal irradiance, and two fluctuatingregimes in which light fluctuations resulting from four andeight vertical circulations of the algae through the water columnwere imposed on the sinusoidal light regime. The total dailylight dose (TDLD) was kept constant. Maximum photosynthesisincreased, and cellular chlorophyll content and photosyntheticunit size decreased in response to light fluctuations. The efficiencyof photosynthesis decreased during the light period in the sinusoidallight regime, whereas it remained at the same level in the fluctuatinglight regimes. The results suggest that prolonged exposure tointermediate irradiances lowers the photosynthetic efficiencyof S.protuberans more than short exposure to high irradiancesalternated by lowlight periods, and that this species is ableto optimize its photosynthesis in fluctuating light.     

Cloning and characterization of the bgxA gene from Erwinia chrysanthemi D1 which encodes a β-glucosidase/xylosidase enzyme

A β-glucosidase/xylosidase gene from Erwinia chrysanthemi strain D1 was cloned and sequenced. This gene, named bgxA, encodes a ca. 71 kDa protein product which, following removal of the leader peptide, resulted in a ca. 69 kDa mature protein that accumulated in the periplasmic space of E. chrysanthemi strain D1 and Escherichia coli cells expressing the cloned gene. The protein exhibited both β-glucosidase and β-xylosidase activities but gave no detectable activity on xylan or carboxymethyl cellulose. The enzyme was classified as a type 3 glycosyl hydrolase, but was unusual in having a truncated B region at the carboxyl-terminus. Several E. chrysanthemi strains isolated from corn produced the glucosidase/xylosidase activity but not those isolated from dicot plants. However, bgxA marker exchange mutants of strain D1 were not detectably altered in virulence on corn leaves.     

‘I was celebrating the justice that the victims got’: exploring irreconciliation among Bangladeshi human rights activists in London

This essay investigates transnational human rights activist networks seeking justice for war crimes committed during the Bangladesh War of 1971, especially in light of the International Crimes Tribunal in Dhaka, Bangladesh. Focusing on activists in London, it demonstrates the need to engage with transitional justice initiatives discursively and ethnographically in order to avoid losing sight of the ways in which uses of human rights concepts can veil power dimensions through universalist legalistic abstractions. The essay explores engagements with atrocities of the war by mapping the travel and uses of human rights tropes to articulate claims of justice. It showcases how in addressing the violence of the Bangladesh War, victor justice and punishment are emphasized while futures are imagined in which enemies no longer exist. In the examples, a language of justice is employed to call for prosecution, but justice is reframed so that it is equated with the impossibility of reconciling people on opposing sides during the war.     

Adaptive responses in resurgent Lake Victoria cichlids over the past 30 years

Textbook examples of adaptive radiation like the Galapagos finches and the East-African cichlids form a subject of major interest in evolutionary biology. Many of these species often show rapid morphological changes in response to a perturbed environment. The dramatic ecological changes in Lake Victoria during the past three decades, e.g. Nile perch predation and eutrophication, provide a unique opportunity to study environmental effects on cichlid morphology. Preliminary research has revealed that the lake’s haplochromines tend to be extremely plastic and sensitive to these environmental changes. So far, long-term ecomorphological studies at short-term intervals are extremely rare. In this study, we examined morphological changes over a 30 year period in six haplochromine species. Geometric morphometric analyses at intervals of approximately 3 years revealed adaptive responses. Three out of four resurgent haplochromines had a smaller head surface/caudal peduncle area (HS/CPA) ratio during the upsurge of the predatory Nile perch. During the same period, all four resurgent species had a larger cheek depth and a smaller eye size. The smaller HS/CPA ratio and larger cheek depth are likely to be adaptive responses to a high predation pressure and a diet shift to larger prey. The smaller eye size seems to be the result of a trade off between the eyes and other morphological structures in the smaller head of these species. Interestingly, the direction of the morphological changes was different between the four resurgent cichlid species and two species that became extremely rare or even may have gone extinct. The HS/CPA ratio increased in the extinct species where it decreased in the resurgent species. This study suggests that predation is a major driver of these morphological changes, which may be due to either phenotypic plasticity or adaptive changes.