Activin promotes oocyte development in ovine preantral follicles in vitro

Activins have been implicated as important regulating factors for many reproductive processes. The aim of this study was to determine the effect of activin A on the development of ovine preantral follicles in vitro. Mechanically isolated preantral follicles (161 ± 2 microm) were cultured for 6 days in the presence of human recombinant activin A (0, 10 and 100 ng/ml). Half of the medium was replaced every second day and follicle diameters were measured. Conditioned medium was subsequently analysed for oestradiol content using a delayed enhancement lanthanide fluorometric immunoassay (DELFIA). At the end of the culture period, follicles were fixed and processed for histology, after which oocyte diameter and granulosa cell death were measured. There was significant follicle growth over 6 days in all groups (p < 0.001). Activin, at both concentrations, increased follicle growth over control levels by Day 6 (p < 0.05). Oocyte diameters were also significantly increased by Day 6 of culture in all groups (p < 0.05), with 100 ng/ml activin increasing oocyte diameter over control levels (p < 0.05). Activin, at both concentrations, increased oestradiol production on Day 2 of culture, but this increase was not sustained during the culture period. Moreover, activin did not have any effect on antrum formation or follicle survival. In conclusion, activin promoted ovine preantral follicle and oocyte growth in vitro, but did not accelerate follicle differentiation over a six-day culture period. These results support a paracrine role for activin A during early oocyte and follicular development

The potential impact of technological innovation on the aquaculture industry

From Executive Summary: Farming of the sea has a long history in many countries, essentially based on a range of modified low-input natural systems, including ponds, shellfish beds and simple enclosures or cages. In the last two decades the intensive farming of marine fish and the scaling up of shellfish culture has been a major trend, prompted by rising demand for aquatic food products precisely when traditional supplies from capture fisheries are in steep decline

Absolute Position of Targets Measured Through a Chamber Window Using Lidar Metrology Systems

Lidar is a useful tool for taking metrology measurements without the need for physical contact with the parts under test. Lidar instruments are aimed at a target using azimuth and elevation stages, then focus a beam of coherent, frequency modulated laser energy onto the target, such as the surface of a mechanical structure. Energy from the reflected beam is mixed with an optical reference signal that travels in a fiber path internal to the instrument, and the range to the target is calculated based on the difference in the frequency of the returned and reference signals. In cases when the parts are in extreme environments, additional steps need to be taken to separate the operator and lidar from that environment. A model has been developed that accurately reduces the lidar data to an absolute position and accounts for the three media in the testbed air, fused silica, and vacuum but the approach can be adapted for any environment or material. The accuracy of laser metrology measurements depends upon knowing the parameters of the media through which the measurement beam travels. Under normal conditions, this means knowledge of the temperature, pressure, and humidity of the air in the measurement volume. In the past, chamber windows have been used to separate the measuring device from the extreme environment within the chamber and still permit optical measurement, but, so far, only relative changes have been diagnosed. The ability to make accurate measurements through a window presents a challenge as there are a number of factors to consider. In the case of the lidar, the window will increase the time-of-flight of the laser beam causing a ranging error, and refract the direction of the beam causing angular positioning errors. In addition, differences in pressure, temperature, and humidity on each side of the window will cause slight atmospheric index changes and induce deformation and a refractive index gradient within the window. Also, since the window is a dispersive media, the effect of both phase and group indices have to be considered. Taking all these factors into account, a method was developed to measure targets through multiple regions of different materials and produce results that are absolute measurements of target position in three-dimensional space, rather than simply relative position. The environment in which the lidar measurements are taken must be broken down into separate regions of interest and each region solved for separately. In this case, there were three regions of interest: air, fused silica, and vacuum. The angular position of the target inside the chamber is solved using only phase index and phase velocity, while the ranging effects due to travel from air to glass to vacuum/air are solved with group index and group velocity. When all parameters are solved simultaneously, an absolute knowledge of the position of each target within an environmental chamber can be derived. Novel features of this innovation include measuring absolute position of targets through multiple dispersive and non-dispersive media, deconstruction of lidar raw data from a commercial off-the-shelf unit into reworkable parameters, and use of group velocities to reduce range data. Measurement of structures within a vacuum chamber or other harsh environment, such as a furnace, may now be measured as easily as if they were in an ambient laboratory. This analysis permits transformation of the raw data into absolute spatial units (e.g., mm). This technique has also been extended to laser tracker, theodolite, and cathetometer measurements through refractive media

Biology and stock status of inshore demersal scalefish indicator species in the Gascoyne Coast Bioregion

(114°50\u27E), includes the iconic Shark Bay and Ningaloo World Heritage areas plus the regional centre of Carnarvon and coastal towns of Denham, Coral Bay and Exmouth. The Gascoyne Bioregion is a transition zone between tropical and temperate waters and supports a diverse range of commercial invertebrate and scalefish fisheries and provides a large variety of recreational fishing opportunities. This report investigates the stock status of the inshore demersal scalefish “suite” of species for the Gascoyne region. These bottom dwelling fish are primarily taken by line fishing in waters of 20-250 m depth by both the commercial and recreational sectors

A Risk Benefit Analysis of Mariculture as a means to Reduce the Impacts of Terrestrial Production of Food and Energy

The Scottish Aquaculture Research Forum (SARF) and WWF-UK commissioned this study to investigate whether the pressure on land and freshwater for future food and energy resources, and impacts on the climate, related to greenhouse gas (GHG) emissions, may be reduced through expansion of global mariculture. The study has undertaken a high level assessment of the &lsquo;environmental footprint&rsquo; of global mariculture and terrestrial-based food and energy production systems through the collation and assessment of available Life Cycle Assessments (LCA) for key food products (beef, pork, chicken, freshwater finfish, marine finfish, shellfish and crustacean species) and biomass (terrestrial and algal) for energy production. The outputs of the footprint comparison were then used to assess the risks and benefits of increasing global mariculture, through the development of projected future scenarios in which mariculture contributes differing proportions of projected future food requirements. The analysis also qualitatively considered the socio-economic and wider environmental risks and benefits (e.g. in relation to ecosystem services) of global mariculture expansion, where expansion may occur geographically and whether future technological developments may help mitigate against identified impacts. The study identifies the key uncertainties and limitations of the risk/benefit analysis and makes prioritised recommendations on how these limitations can be addressed and the analysis developed for more regional or site-specific assessments

OXIDATIVE ENZYMES AND THE INJURY METABOLISM OF DIAPAUSING CECROPIA SILKWORMS *

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75474/1/j.1749-6632.1960.tb27576.x.pd

Clinical applications and limitations of current ovarian stem cell research: a review

The publication of a report in Nature in 2004 by the Tilly group suggesting that mouse ovaries are capable of generating oocytes de novo post-natally, has sparked interest in a problem long thought to have been resolved from classical studies in a variety of mammalian species. Within a nearly two year time period, laboratories around the world have taken up the challenge to dogma raised by this initial report, either to test this concept in an experimental basic science setting or give direction to clinical applications that could result, were the original premises of this work in the mouse valid for extrapolation to humans. This review provides a status report for this promising area of research, (1) to summarize recent findings in the literature with respect to the validity of the original hypothesis proffered by the Tilly group, and, (2) to gauge the potential utility of ovarian stem cells as a treatment for certain forms of human infertility

Strategic Considerations for Locational Regulation of Shellfish Aquaculture in Scotland

Aquaculture is an increasingly important industry for Scotland, helping to sustain economic growth in the rural and coastal communities, and producing Scotland’s most valuable food export. In 2014, the Scottish shellfish farming industry produced almost 8,000 tonnes of shellfish for consumption, estimated to be worth approximately £10.5million. The Scottish shellfish aquaculture industry is aiming to double production volumes by 2020, compared to 2012, and the Scottish Government supports the achievement of these growth targets, with due regard to the marine environment, and refers to the targets in Scotland’s National Marine Plan (NMP) and Strategic Framework for Scottish Aquaculture. Sustainable development demands that such expansion respects environmental limits so that the capacity of the marine environment to accommodate economic development activity is not exceeded. This requires consistent and effective regulation of shellfish aquaculture development to set limits which protect the marine environment but which don’t unnecessarily constrain expansion. The Scottish Aquaculture Research Forum (SARF) commissioned this study to undertake a systematic review of the shellfish aquaculture planning decision-making process after concerns regarding the degree of consistency with which planning applications are treated in different parts of Scotland were raised by the Ministerial Group on Sustainable Aquaculture (MGSA), particularly in relation to the issue of biological carrying capacity. The study objectives were met through undertaking a review of the shellfish planning applications and determinations made in Scotland between 2009 and 2014 and through consultation with key stakeholders in the process including local planning authorities (LPAs), regulators, other statutory consultees in the planning process, industry representatives and individual shellfish businesses/farmers. The initial findings were also discussed with key stakeholders at a project workshop held in October 2015. The results of the planning review showed that of the 148 planning applications made between 2009 and 2014 (118 for mussels, 26 for oyster and 4 for integrated multi-trophic aquaculture (IMTA) developments), 131 were granted (89%), 9 were withdrawn (6%) and 8 were refused (5%). These results do not indicate that the planning determination system has unduly constrained the development of the industry over this time period through overly conservative determinations. Overall, the study found that there was consistency in the approach to planning considerations and determinations across Scotland. The one exception to this was the finding that the current model used to assess the risk of exceedance of biological carrying capacity for proposed shellfish developments produced different results when used by the two end users (the LPA and the statutory consultee) who assess this issue for applications in the Shetland Islands. The reason for this relates to the LPA making allowance for the carrying capacity for the indigenous wild shellfish populations within the model (i.e. using a safety margin for wild shellfish stocks), while the statutory consultee does not as they consider the model to be sufficiently precautionary. Consultation with stakeholders did highlight a number of more minor but nevertheless important issues, where there is opportunity to improve both the planning and wider consenting process and help support sustainable expansion of the industry. Within the determination process, landscape and visual impacts (particularly cumulative impacts) and impacts on commercial fisheries are relatively difficult considerations for LPAs to assess. Aspects of the planning process which concerned industry stakeholders included the cost of the process (including the proportionality of the planning fees for the shellfish industry), competition for space with other marine sectors and unutilised capacity (consented sites not producing fish or shellfish). Stakeholders also felt that the wider consenting regime for the aquaculture industry was complex and that there was an element of duplication between the different consents required. The study also briefly considered future influences on the planning process and the shellfish aquaculture industry. Indicative future projections of shellfish production suggested that the 2020 production targets (13,000 tonnes) may not be met at the current industry growth rate. Expansion of the industry requires expansion at existing and new sites to be available with suitable natural resources and minimal constraints relating to other marine users. The incoming regional marine plans, where based on good data, should be a useful source of information for developers and support industry development where it is appropriate