Structural aspects of the growth and reproduction of Saprolegnia SPP

Imperial Users onl

Building a compliance audit for BS7988 “Code of practice for the use of information technology (IT) in the delivery of assessments”

The BS7988 standard is now formally published, and is broadly in line with the provisional specification presented by John Kleeman, David Keech and Stephen Wright to this conference last year. Compliance with the standard requires quality assurance across a wide range of areas - hardware, software, network, data storage and human issues are all covered. It requires consideration of security, reliability and accessibility. In this session we will work collectively to build a provisional framework for a QA system to cover those areas of the Standard that fall within the remit of conference delegates, principally those relating to software development. The output of the session will be a draft of a quality audit that can be published as part of the conference proceedings. While clearly this will be very much a first-stage document, we hope that it will provide pointers for further work in this area

The Role of Matrix Metalloproteinases In Influencing Stem Cell Behavior and Skeletal Muscle Healing

Stem cells are highly valued for their capacity to aid in the functional recovery of damaged or diseased tissue. They are defined by their remarkable ability to maintain their undifferentiated state through countless cycles of cell division and to differentiate into variable types of specialized cells. Since ethical controversy has hindered funding for embryonic stem cell research and induced pluripotent stem cells are in the initial stages of investigations, much research has been conducted using adult stem cells. The use of adult stem cells in clinical applications is gradually becoming a reality; however, the major limitation is the difficulty to isolate, purify and expand them in culture. Matrix metalloproteinases (MMPs) have been regarded as a group of zinc-endopeptidases that influence tissue remodeling by degrading constituents of the extracellular matrix to actively promote cell proliferation, migration, apoptosis and differentiation. They have been suggested to play important roles in the regeneration of amputated newt limbs by contributing to a population of undifferentiated stem cells, called a blastema, which is likely formed by cell dedifferentiation. The research presented here builds on previous work investigating the therapeutic use of MMP1. Investigations have demonstrated the ability of MMP1 to aid in the recovery of skeletal muscle tissue by degrading fibrous scar tissue to facilitate cell migration and differentiation. This work examines the potential of MMP1 in skeletal muscle healing to stimulate stem cell behavior by the expression of certain muscle stem cell markers and its impact on cell differentiation. In addition, stem cells derived from skeletal muscle tissue were investigated to thoroughly elucidate the effect of blocking MMP signaling. MMP inhibition using GM6001 was observed to negatively impact muscle stem cell migration, stem cell associated markers and their differentiation capacity thus indicating the key role of MMPs in muscle stem cell behavior

A phase field method for tomographic reconstruction from limited data.

Classical tomographic reconstruction methods fail for problems in which there is extreme temporal and spatial sparsity in the measured data. Reconstruction of coronal mass ejections (CMEs), a space weather phenomenon with potential negative effects on the Earth, is one such problem. However, the topological complexity of CMEs renders recent limited data reconstruction methods inapplicable. We propose an energy function, based on a phase field level set framework, for the joint segmentation and tomographic reconstruction of CMEs from measurements acquired by coronagraphs, a type of solar telescope. Our phase field model deals easily with complex topologies, and is more robust than classical methods when the data are very sparse. We use a fast variational algorithm that combines the finite element method with a trust region variant of Newton’s method to minimize the energy. We compare the results obtained with our model to classical regularized tomography for synthetic CME-like images

Fate of the Organophosphate Insecticide, Chlorpyrifos, in Leaves, Soil, and Air Following Application

A field study was conducted to further our understanding about the fate and transport of the organophosphate insecticide, chlorpyrifos, and its degradation product, chlorpyrifos oxon. Leaf, soil and air sampling was conducted for 21 days after chlorpyrifos application to a field of purple tansy (Phacelia tanacetifolia). Air samples were collected using a high-volume air sampler (HVAS) and seven battery-operated medium-volume active air samplers placed around the field and on a 500-m transect extending away from the field. Chlorpyrifos was detected every day of the sampling period in all matrices, with concentrations decreasing rapidly after application. Chlorpyrifos oxon was only detected in air samples collected with the HVAS during the first three days after application. Wind direction played a significant role in controlling the measured air concentrations in near-field samples. The SCREEN3 model and chlorpyrifos’ Characteristic Travel Distance (CTD) were used to predict modelled chlorpyrifos concentrations in air along the transect. The concentration trend predicted by the SCREEN3 model was similar to that of measured concentrations whereas CTD-modelled concentrations decreased at a significantly slower rate, indicating that downwind chlorpyrifos concentrations in air were primarily controlled by air dispersion. The SCREEN3-predicted chlorpyrifos concentrations were \u3e5 times higher than measured concentrations, indicating that simple approaches for calculating accurate pesticide volatilization fluxes from agricultural fields are still needed. Finally, we found that measured concentrations in air on Days 0–2 at locations up to 500 m from the field were at levels considered concerning for human health

(-)-Epigallocatechin-3-gallate (EGCG) maintains k-casein in its pre-fibrillar state without redirecting its aggregation pathway

The polyphenol (-)-epigallocatechin-3-gallate (EGCG) has recently attracted much research interest in the field of protein-misfolding diseases because of its potent anti-amyloid activity against amyloid-beta, alpha-synuclein and huntingtin, the amyloid-fibril-forming proteins involved in Alzheimer\u27s, Parkinson\u27s and Huntington\u27s diseases, respectively. EGCG redirects the aggregation of these polypeptides to a disordered off-folding pathway that results in the formation of non-toxic amorphous aggregates. whether this anti-fibril activity is specific to these disease-related target proteins or ismore generic remains to be established. In addition, the mechanism by which EGCG exerts its effects, as with all anti-amyloidogenic polyphenols, remains unclear. To address these aspects, we have investigated the ability of EGCG to inhibit amyloidogenesis of the generic model fibril-forming protein RCMkappa-CN (reduced and carboxymethylated kappa-casein) and thereby protect pheochromocytoma-12 cells from RCMkappa-CN amyloid-induced toxicity. We found that EGCG potently inhibits in vitro fibril formation byRCMkappa-CN [the IC50 for 50 uM RCMkappa-CN is 1 uM]. Biophysical studies reveal that EGCG prevents RCMkappa-CN fibril formation by stabilising RCMkappa-CN in its nativelike state rather than by redirecting its aggregation to the disordered, amorphous aggregation pathway. Thus, while it appears that EGCG is a generic inhibitor of amyloid-fibril formation, the mechanism by which it achieves this inhibition is specific to the target fibril-forming polypeptide. It is proposed that EGCG is directed to the amyloidogenic sheet-turn-sheet motif of monomeric RCMkappa-CN with high affinity by strong non-specific hydrophobic associations. Additional non-covalent pi-pi stacking interactions between the polyphenolic and aromatic residues common to the amyloidogenic sequence are also implicated