J. A. Pitcher results 26
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Expansion of adult stem cells in culture increases the percent of senescent cells, reduces their differentiation capacity and limits their clinical use. Here, we investigated whether treatment with certain senotherapeutic drugs would reduce the accumulation of senescent cells during expansion of human liver stem cells (HLSCs) while maintaining their differentiation capacity. Our results demonstrate that chronic treatment with...
Bottom trawl fishing is a controversial activity. It yields about a quarter of the world's wild seafood, but also has impacts on the marine environment. Recent advances have quantified and improved understanding of large‐scale impacts of trawling on the seabed. However, such information needs to be coupled with distributions of benthic invertebrates (benthos) to assess whether these populations are being sustained under curren...
We describe a human and large animal Langendorff experimental apparatus for live electrophysiological studies and measure the electrophysiological changes due to gap junction uncoupling in human and porcine hearts. The resultant ex vivo intact human and porcine model can bridge the translational gap between smaller simple laboratory models and clinical research. In particular, electrophysiological models would benefit from the...
Choosing best practices for managing impacts of trawl fishing on seabed habitats and biotaNARA Subscribed
Bottom trawling accounts for almost one quarter of global fish landings but may also have significant and unwanted impacts on seabed habitats and biota. Management measures and voluntary industry actions can reduce these impacts, helping to meet sustainability objectives for fisheries, conservation and environmental management. These include changes in gear design and operation of trawls, spatial controls, impact quotas and ef...
Bottom‐contact fishing gears are globally the most widespread anthropogenic sources of direct disturbance to the seabed and associated biota. Managing these fishing disturbances requires quantification of gear impacts on biota and the rate of recovery following disturbance. We undertook a systematic review and meta‐analysis of 122 experiments on the effects‐of‐bottom fishing to quantify the removal of benthos in the path of th...
This study examined whether polyandrous female Chinook salmon Oncorhynchus tshawytscha obtain benefits compared with monandrous females through an increase in hatching success. Both of the alternative reproductive tactics present in male O. tshawytscha (large hooknoses and small, precocious jacks) were used, such that eggs were either fertilized by a single male (from each tactic) or multiple males (using two males from the sa...
Plenty more fish in the sea?NARA Subscribed
Only in the last century did humans overwhelmingly accept that fisheries resources are finite. Consequently, ‘there are more fish still in the sea than ever came out of it’ served as a popular metaphor for unbounded expectations for half a millennium, expectations that also extended to use of the planet in general. By reconstructing historical fishing back 1200 years, we identify when this metaphor actually ceased to be true....
Prioritization of knowledge‐needs to achieve best practices for bottom trawling in relation to seabed habitatsNARA Subscribed
Management and technical approaches that achieve a sustainable level of fish production while at the same time minimizing or limiting the wider ecological effects caused through fishing gear contact with the seabed might be considered to be ‘best practice’. To identify future knowledge‐needs that would help to support a transition towards the adoption of best practices for trawling, a prioritization exercise was undertaken wit...
Provenance of global seafoodNARA Subscribed
Knowing where and how seafood is caught or farmed is central to empowering consumers, and the importers that supply them, with informed choices. Given the wide‐ranging, complex and at times commercially sensitive nature of global seafood trade, it can prove very challenging to link imported seafood with information about its provenance. The databases involved are incomplete, at times vague and not harmonized. Here, we present...
Improvements to Rapfish: a rapid evaluation technique for fisheries integrating ecological and human dimensions aNARA Subscribed
This paper reports recent developments in Rapfish, a normative, scalable and flexible rapid appraisal technique that integrates both ecological and human dimensions to evaluate the status of fisheries in reference to a norm or goal. Appraisal status targets may be sustainability, compliance with a standard (such as the UN code of conduct for responsible fisheries) or the degree of progress in meeting some other goal or target....
Bayesian Decision‐Network Modeling of Multiple Stakeholders for Reef Ecosystem Restoration in the Coral TriangleNARA Subscribed
Proposals for marine conservation measures have proliferated in the last 2 decades due to increased reports of fishery declines and interest in conservation. Fishers and fisheries managers have often disagreed strongly when discussing controls on fisheries. In such situations, ecosystem‐based models and fisheries‐stock assessment models can help resolve disagreements by highlighting the trade‐offs that would be made under alte...
Biophysical patterns in benthic assemblage composition across contrasting continental margins off New ZealandNARA Subscribed
Aim To examine whether benthic assemblages are more diverse in a region of high topographic and oceanographic complexity by comparing benthic invertebrate assemblages across continental margins with contrasting environments. Location Challenger Plateau and Chatham Rise, to the west and east of New Zealand, respectively. Methods Benthic faunal data were sourced from extensive seabed surveys in 2007, when both margins were sampl...
Uncertainties in climate stabilizationNARA Subscribed
A study was undertaken to examine sperm morphometry in relation to sperm velocity and sperm longevity in the redside dace Clinostomus elongatus . There was significant between‐male variance in sperm size and shape metrics (total sperm length, sperm head length, flagellum length and sperm head length to width ratio) and positive relationships were found between these morphometrics and sperm velocity. There were no significant r...
The onset of sexual behaviour in three age classes of male guppy Poecilia reticulata occurred in synchrony with the appearance of body colouration and anal fin differentiation but not with sperm production. There was also a positive correlation between sperm production and sexual behaviour in the two older age classes.
Foraging, timidity and shoal size in minnows and goldfishNARA Subscribed