The In-Vitro Life-Cycle Of A Perkinsus Species (Apicomplexa, Perkinsidae) Isolated From Macoma-Balthica (Linneaus, 1758)

Using standard sterile techniques and a single medium previously described (Kleinschuster and Swink 1993), the in vitro culture of a Perkinsus species isolated from Macoma balthica was possible. Zoosporulation, the release of zoospores, and the reestablishment of secondary cultures from the zoospores completed an in vitro life cycle

Domain structure of human complement C4b extends with increasing NaCl concentration: implications for its regulatory mechanism

During the activation of complement C4 to C4b, the exposure of its thioester domain (TED) is crucial for the attachment of C4b to activator surfaces. In the C4b crystal structure, TED forms an Arg(104)-Glu(1032) salt bridge to tether its neighbouring macroglobulin (MG1) domain. Here, we examined the C4b domain structure to test whether this salt bridge affects its conformation. Dual polarisation interferometry of C4b immobilised at a sensor surface showed that the maximum thickness of C4b increased by 0.46 nm with increase in NaCl concentration from 50 mM to 175 mM NaCl. Analytical ultracentrifugation showed that the sedimentation coefficient s20, w of monomeric C4b of 8.41 S in 50 mM NaCl buffer decreased to 7.98 S in 137 mM NaCl buffer, indicating that C4b became more extended. Small angle X-ray scattering reported similar RG values of 4.89-4.90 nm for C4b in 137-250 mM NaCl. Atomistic scattering modelling of the C4b conformation showed that TED and the MG1 domain were separated by 4.7 nm in 137-250 mM NaCl, this being greater than that of 4.0 nm in the C4b crystal structure. Our data reveal that in low NaCl concentrations, both at surfaces and in solution, C4b forms compact TED-MG1 structures. In solution, physiologically-relevant NaCl concentrations lead to the separation of the TED and MG1 domain, making C4b less able to bind to its complement regulators. These conformational changes are similar to those seen previously for complement C3b, confirming the importance of this salt bridge for regulating both C4b and C3b

A silicon-labelled amino acid suitable for late-stage fluorination and unexpected oxidative cleavage reactions in the preparation of a key intermediate in the Strecker synthesis

A novel silicon-substituted phenylalanine derivative was prepared using the Strecker amino acid synthesis. An unexpected oxidative cleavage was observed in the preparation of the aldehyde required for the Strecker reaction. In this step, a homobenzylic alcohol intermediate was oxidatively cleaved to the corresponding benzaldehyde using either chromium or palladium based oxidants. This undesired side reaction was overcome through the use of Dess-Martin Periodinane, or through an efficient TEMPO-bleach oxidation. The amino acid prepared in this study was then labelled with fluoride in aqueous solvent using a range of fluoride sources. The efficiency of this labelling motivates future studies in late-stage fluorination of peptide and protein therapeutics for use in positron emission tomography

Norbornene Probes for the Detection of Cysteine Sulfenic Acid in Cells.

Norbornene derivatives were validated as probes for cysteine sulfenic acid on proteins and in live cells. Trapping sulfenic acids with norbornene probes is highly selective and revealed a different reactivity profile than the traditional dimedone reagent. The norbornene probe also revealed a superior chemoselectivity when compared to a commonly used dimedone probe. Together, these results advance the study of cysteine oxidation in biological systems

Effects of the trawling ban on the diversity of demersal crustaceans (orders: decapoda and stomatopoda) in the marine environment of Hong Kong, South China

Oral PresentationFisheries & Marine Resources ManagementBottom trawling has been demonstrated to be one of the most destructive fishing methods to marine benthic communities. Since the 1970s, marine fishery resources in Hong Kong, especially large predatory species, have been overexploited by non-selective fishing gears including bottom and pelagic trawlers. This fishing down the trophic level has resulted in a benthic ecosystem primarily dominated by small herbivorous and omnivorous fishes and crustaceans. To mitigate such impacts, the Government of the Hong Kong Special Administrative Region has implemented a territory-wide trawling ban in local waters since 31 December 2012. This study aims to investigate whether crustacean resources, in particular of the orders Decapoda and ...postprin

Strategies for cellular decision-making

Stochasticity pervades life at the cellular level. Cells receive stochastic signals, perform detection and transduction with stochastic biochemistry, and grow and die in stochastic environments. Here we review progress in going from the molecular details to the information-processing strategies cells use in their decision-making. Such strategies are fundamentally influenced by stochasticity. We argue that the cellular decision-making can only be probabilistic and occurs at three levels. First, cells must infer from noisy signals the probable current and anticipated future state of their environment. Second, they must weigh the costs and benefits of each potential response, given that future. Third, cells must decide in the presence of other, potentially competitive, decision-makers. In this context, we discuss cooperative responses where some individuals can appear to sacrifice for the common good. We believe that decision-making strategies will be conserved, with comparatively few strategies being implemented by different biochemical mechanisms in many organisms. Determining the strategy of a decision-making network provides a potentially powerful coarse-graining that links systems and evolutionary biology to understand biological design

Neurospora from natural populations: Population genomics insights into the Life history of a model microbial Eukaryote

The ascomycete filamentous fungus Neurospora crassa played a historic role in experimental biology and became a model system for genetic research. Stimulated by a systematic effort to collect wild strains initiated by Stanford geneticist David Perkins, the genus Neurospora has also become a basic model for the study of evolutionary processes, speciation, and population biology. In this chapter, we will first trace the history that brought Neurospora into the era of population genomics. We will then cover the major contributions of population genomic investigations using Neurospora to our understanding of microbial biogeography and speciation, and review recent work using population genomics and genome-wide association mapping that illustrates the unique potential of Neurospora as a model for identifying the genetic basis of (potentially adaptive) phenotypes in filamentous fungi. The advent of population genomics has contributed to firmly establish Neurospora as a complete model system and we hope our review will entice biologists to include Neurospora in their research

DETERMINATION OF THE THERMODYNAMIC PARAMETERS FOR TRANSFER OF ALKOXYPHENOLS FROM AQUEOUS-SOLUTION TO SDS MICELLES BY A TAYLOR-ARIS DIFFUSION TECHNIQUE

Using Taylor-Aris diffusion techniques, thermodynamic parameters have been measured for the transfer of a series of alkoxyphenols from water into SDS micelles. The results are compared with those for transfer to bulk organic solvents and to cells of Escherichia coli. The SDS micelles are found to be marginally more polar than n-octanol, but the results reveal significant differences between bulk solvents and the more ordered micellar pseudophase.87172741274

Conserving intertidal habitats: what is the potential of ecological engineering to mitigate impacts of coastal structures?

Poster presentation: P-62Human ImpactsGlobally, coastal human population growth and urbanization continues in a fast pace, while climatic change leads to stormier seas and rising tides. Both driving forces jointly generate a strong and increasing demand for land reclamation and infrastructure protection in coastal areas which require engineered defence structures such as sea walls. This study aimed to review ecological impacts of coastal engineered structures on intertidal ecosystems, update the current status of ecological engineering to mitigate these impacts, and evaluate the effectiveness of such mitigations in relation to the conservation of intertidal habitats and biodiversity. Engineered structures alter important physical, chemical and biological processes of intertidal habitats, and ...postprin

Spatial and seasonal variations in trophic dynamics of benthic communities of marine molluscs in Hong Kong’s Coastal Waters before and after the Trawling Ban

Poster presentation: P-54Fisheries & Marine Resources ManagementTo rectify the detrimental impact of overfishing and destruction of benthic ecosystems, a territory-wide trawling ban has been imposed in Hong Kong’s coastal marine waters since 31 December 2012. It is anticipated that the local benthic marine ecosystem will gradually recover after the trawl-ban. Using stable isotope analysis (SIA), this study aims to compare trophic dynamics of benthic molluscan communities of eastern, southern and western waters of Hong Kong before and after the trawling ban. The results of this study will also serve as a baseline for studying long-term ecosystem recovery. Trawling ...postprin