Ghost fishing in the pot fishery for blue swimmer crabs Portunus pelagicus in Queensland, Australia

Blue swimmer crabs (Portunus pelagicus) are an economically important crab caught in baited traps throughout the Indo-west Pacific and Mediterranean. In Australia they are traditionally caught using rigid wire traps (approximate to pots) but there has been a recent increase in the use of collapsible pots constructed from polyethylene trawl mesh. Two experiments were conducted in Moreton Bay, Queensland, to determine the ghost fishing potential of lost crab pots on both target and bycatch species and to evaluate the differences between traditional and contemporary pot designs. A lost contemporary, collapsible trawl mesh pot will catch between 3 and 223 R pelagicus per year after the bait has been exhausted, while a traditional wire mesh pot would catch 11-74 crabs peryear. As most fishers now use the collapsible trawl mesh pots, ghost fishing mortality could be as high as 111,811-670,866 crabs per year. Bycatch retention was also higher in contemporary designs. Periods of strong winds appeared to increase the ghost fishing potential of lost pots. The use of escape gaps, larger mesh sizes and construction options that allow for the deterioration of entrance funnels to minimise ghost fishing are recommended to reduce environmental impacts

Local Guided Wavefield Analysis for Characterization of Delaminations in Composites

Delaminations in composite laminates resulting from impact events may be accompanied by minimal indication of damage at the surface. As such, inspection techniques are required to ensure defects are within allowable limits. Conventional ultrasonic scanning techniques have been shown to effectively characterize the size and depth of delaminations but require physical contact with the structure. Alternatively, a noncontact scanning laser vibrometer may be used to measure guided wave propagation in the laminate structure. A local Fourier domain analysis method is presented for processing guided wavefield data to estimate spatially-dependent wavenumber values, which can be used to determine delamination depth. The technique is applied to simulated wavefields and results are analyzed to determine limitations of the technique with regards to determining defect size and depth. Finally, experimental wavefield data obtained in quasi-isotropic carbon fiber reinforced polymer (CFRP) laminates with impact damage is analyzed and wavenumber is measured to an accuracy of 8.5% in the region of shallow delaminations. Keywords: Ultrasonic wavefield imaging, Windowed Fourier transforms, Guided waves, Structural health monitoring, Nondestructive evaluatio

Simulation of Reclaimed-Water Injection and Pumping Scenarios and Particle-Tracking Analysis Near Mount Pleasant, South Carolina

2010 S.C. Water Resources Conference - Science and Policy Challenges for a Sustainable Futur

The Role of Delta Sarcoglycan in Dystrophin-Glycoprotein Complex Function in Cardiac Muscle.

Delta sarcoglycan (δSG) is a highly conserved member of the sarcoglycan complex and the dystrophin-glycoprotein complex (DGC) in muscle cells. The DGC is a multimeric complex at the lateral sarcolemma in muscle that acts as a functional linkage between the cytoskeleton and the extracellular matrix. Muscle undergoes consistent strain through stretch and contraction and the DGC is hypothesized to help protect sarcolemmal integrity during mechanical activity. The role of δSG in the function of the DGC is not well understood. Mutations in the SGCD (coding the δSG protein) gene that are recessively inherited disturb the normal assembly of the DGC resulting in absence of not only δSG, but also the entire sarcoglycan complex and a reduction of dystrophin at the plasma membrane, resulting in limb-girdle muscular dystrophy 2F (LGMD2F). In general, LGMD2F patients have skeletal muscle dystrophy that is on the milder end of the clinical spectrum but patients are at risk for early death from cardiomyopathy. A surprising and unique feature of δSG is that dominantly inherited mutations within the δSG gene have been linked to dilated cardiomyopathy (DCM) with no accompanying skeletal muscle phenotype. The lack of skeletal muscle dystrophy indicates the likely presence of an intact and functional DGC within skeletal muscle. In this thesis, I tested the overall working hypothesis that dominant mutations in the extracellular domain of δSG alter protein structure or post-translational modifications causing DGC dysfunction and lead to disrupted mechanical stability of cardiac myocytes. I show here that DCM-linked δSG mutants R97Q and R71T, when expressed integrate into the plasma membrane and do not disturb the natural localization and assembly of the DGC indicating a likely dominant negative mechanism of action. When submitted to mechanical strain cardiac myocytes expressing δSG mutant R97Q or R71T have compromised sarcolemmal integrity indicating that δSG plays a functional role in the protection of the plasma membrane by the DGC during mechanical activity.PhDMolecular and Integrative PhysiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/98049/1/mdcampbe_1.pd

Surviving the effects of barotrauma: assessing treatment options and a ‘natural’ remedy to enhance the release survival of line caught pink snapper (Pagrus auratus)

A new technique to ameliorate the effects of barotrauma was tested based on observations of pink snapper, Pagrus auratus (Forster), inadvertently piercing their everted stomach with their teeth and releasing trapped swim bladder gases. This technique was termed buccal venting and involved piercing the everted stomach protruding into the buccal cavity or out of the mouth with a 16-gauge hypodermic needle (a practice previously not encouraged). Short-term (~3 days) survival of buccal-vented fish was not significantly different from laterally vented fish nor untreated controls. Both buccal and lateral venting techniques were shown to cause no harm and allowed fish to return to depth. The short-term (1–3 days) post-release survival of line caught snapper was 88% with no significant difference in survival across three depth ranges tested (37–50, 51–100 and 101–180 m). Survival of sublegal pink snapper ( 0.05) from that of legal-sized fish (≥35 cm TL). Healing of the swim bladder was observed in 27% of pink snapper dissected after ≤3 days in captivity, and healing of stomachs was observed in 64% of pink snapper that had been buccal vented. Relatively high post-release survival rates of line caught pink snapper may offer some protection for snapper stocks where high fishing pressure and legal size restrictions result in the majority of the catch having to be released

Oxidation state of a polyurethane membrane after plasma etching

Low moduli cell culture substrates can be used to apply dynamic mechanical strain to cells, by surface deformation. Understanding the surface interaction with cells is critical to improving cell adhesion and normal growth. A medical grade polyurethane (PU), Chronoflex AL 80A, was modified by oxygen plasma etching and characterised by X-ray photoelectron spectroscopy. Etching resulted in increased cross-linking at the isocyanate bond and formation of new oxygen moieties. The model, derived from patent data and XPS data of the unetched PU, indicated that the additional oxygen was likely to be hydroxyl and carbonyl groups. Etched membranes enhanced protein adhesion, resulting in full surface coverage compared to unetched PU. The etched PU supported cell adhesion and spreading, while the unetched PU was not conducive to monolayer formation

Short-term survival of discarded pearl perch (Glaucosoma scapulare Ramsay, 1881) caught by hook-and-line in Queensland, Australia

Post-release survival of line-caught pearl perch (Glaucosoma scapulare) was assessed via field experiments where fish were angled using methods similar to those used by commercial, recreational and charter fishers. One hundred and eighty-three individuals were caught during four experiments, of which >91% survived up to three days post-capture. Hook location was found to be the best predictor of survival, with the survival of throat- or stomach-hooked pearl perch significantly (P < 0.05) lower than those hooked in either the mouth or lip. Post-release survival was similar for both legal (≥35 cm) and sub-legal (<35 cm) pearl perch, while those individuals showing no signs of barotrauma were more likely to survive in the short term. Examination of the swim bladders in the laboratory, combined with observations in the field, revealed that swim bladders rupture during ascent from depth allowing swim bladder gases to escape into the gut cavity. As angled fish approach the surface, the alimentary tract ruptures near the anus allowing swim bladder gases to escape the gut cavity. As a result, very few pearl perch exhibit barotrauma symptoms and no barotrauma mitigation strategies were recommended. The results of this study show that pearl perch are relatively resilient to catch-and-release suggesting that post-release mortality would not contribute significantly to total fishing mortality. We recommend the use of circle hooks, fished actively on tight lines, combined with minimal handling in order to maximise the post-release survival of pearl perch

The initiator methionine tRNA drives cell migration and invasion leading to increased metastatic potential in melanoma

The cell's repertoire of transfer RNAs (tRNAs) has been linked to cancer. Recently, levels of the initiator methionine tRNA (tRNAiMet) in stromal fibroblasts have been shown to influence extracellular matrix (ECM) secretion to drive tumour growth and angiogenesis. Here we show that increased tRNAiMet within cancer cells does not influence tumour growth, but drives cell migration and invasion via a mechanism that is independent from ECM synthesis and dependent on α5β1 integrin and levels of the translation initiation ternary complex. In vivo and ex vivo migration (but not proliferation) of melanoblasts is significantly enhanced in transgenic mice which express additional copies of the tRNAiMet gene. We show that increased tRNAiMet in melanoma drives migratory, invasive behaviour and metastatic potential without affecting cell proliferation and primary tumour growth, and that expression of RNA polymerase III-associated genes (which drive tRNA expression) are elevated in metastases by comparison with primary tumours. Thus specific alterations to the cancer cell tRNA repertoire drive a migration/invasion programme that may lead to metastasis

Securing tropical forest carbon: the contribution of protected areas to REDD

Forest loss and degradation in the tropics contribute 6-17% of all greenhouse gas emissions. Protected areas cover 217.2 million ha (19.6%) of the world's humid tropical forests and contain c. 70.3 petagrams of carbon (Pg C) in biomass and soil to 1 m depth. Between 2000 and 2005, we estimate that 1.75 million ha of forest were lost from protected areas in humid tropical forests, causing the emission of 0.25-0.33 Pg C. Protected areas lost about half as much carbon as the same area of unprotected forest. We estimate that the reduction of these carbon emissions from ongoing deforestation in protected sites in humid tropical forests could be valued at USD 6,200-7,400 million depending on the land use after clearance. This is >1.5 times the estimated spending on protected area management in these regions. Improving management of protected areas to retain forest cover better may be an important, although certainly not sufficient, component of an overall strategy for reducing emissions from deforestation and forest degradation (REDD