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Terrence R. Tiersch - One of the best experts on this subject based on the ideXlab platform.
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3-D Printed Customizable Vitrification Devices for Preservation of Genetic Resources of Aquatic Species.
Aquacultural engineering, 2020Co-Authors: Connor J. Tiersch, Terrence R. Tiersch, Yue Liu, William T. MonroeAbstract:Abstract Sperm vitrification as an alternative approach to conventional cryopreservation (equilibrium freezing) allows quick and low-cost sample preservation and is suitable for small-bodied Aquatic Species with miniscule testis, fieldwork at remote locations, and small-scale freezing for research purposes. The goal of this present study was to develop operational prototypes of 3-dimensional (3-D) printed vitrification devices with innovative components that can provide comprehensive functionalities for practical repository development for Aquatic Species. The design featured an elongated loop to suspend a thin film of sperm sample in cryoprotectant, a retractable sleeve to protect the vitrified samples and allow permanent labeling, a handle to facilitate processing and storage, and a shaft with annular grooves to guide positioning of the protective retractable sleeve. To span a wide range of sample capacities and configurations, a total of 39 different configurations (3 loop lengths ×13 loop heights) were fabricated by 3-D printing with the thermoplastics polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS). A total of 86 devices were fabricated with ABS filament with a print failure rate of 9%, and 97 devices were fabricated with PLA filament with a failure rate of 20 %. Major types of printing failures included disconnected loops, insufficient build surface adhesion, stringing, and inconsistent extrusion. The sample volume capacity ranged from 1 to 47 μL and had linear relationships to the loop lengths and layer numbers. Vitrified samples were observed in 10-mm and 15-mm loops fabricated with PLA and ABS but not in 20-mm loops. This study demonstrated the feasibility of development of standardized low-cost ($0.05 material cost) devices fabricated by 3-D printing with practical functions including vitrification, volume control, labeling, protection, and storage within conventional systems. These prototypes can be further developed, standardized, and used to assist development of germplasm repositories to protect the genetic resources of Aquatic Species by user groups such as breeders, hatcheries, aquariums, and researchers.
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addressing reproducibility in cryopreservation and considerations necessary for commercialization and community development in support of genetic resources of Aquatic Species
Journal of The World Aquaculture Society, 2018Co-Authors: Leticia Torres, Terrence R. TierschAbstract:Abstract For the past six decades a repeated cycle of developing new cryopreservation protocols or simply reinventing them to counteract a lack of reproducibility has led to hundreds of published studies that have offered little to the establishment of a genetic resources community for Aquatic Species. This has hampered repository development and inhibited industrial application. Most protocols were developed without standardized approaches, leading to irreproducible studies and questionable or meaningless comparisons. Thus cryopreservation of germplasm in Aquatic Species would greatly benefit from strategies to facilitate reproducibility. Our objectives were to: (1) identify major sources of irreproducibility across research, small-scale, repository, and commercial-scale development levels, (2) provide recommendations to address reproducibility challenges, and (3) offer suggestions on how researchers can directly influence commercial development and application of cryopreservation research. Sources of irreproducibility include lack of standardized procedural approaches, lack of standardized terminology, and lack of reporting guidelines. To address these challenges, we propose implementation of standard operating procedures (SOP), support of stock centers and internet content for development of training programs, and strengthening of the role of scientific journals and reviewers in reducing the frequency of irreproducible outcomes. Reproducibility is the foundation for quality management programs and product reliability, and therefore standardization is necessary to assure efficient transition to commercial-scale application and repository development. Progress can only be possible through community-based approaches focused on coalescence and consensus of disparate groups involved in Aquatic Species cryopreservation and management of genetic resources.
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Standardized Assessment of Thin-film Vitrification for Aquatic Species
North American journal of aquaculture, 2017Co-Authors: Nolan J. Tiersch, Terrence R. TierschAbstract:AbstractUltrarapid cooling under the appropriate conditions will produce vitrification, a glass-like state used to cryopreserve small sample volumes, but there are a number of major technical drawbacks impeding the application of vitrification to germplasm of Aquatic Species. These include a lack of suitable devices, and poor reproducibility and comparability among studies due to a lack of standardization. We used 3-D printing to produce a viewing pedestal coupled with a classification system to rapidly assess frozen film quality of vitrification loops. Classification time declined with practice from 2.1 ± 0.3 sec (mean ± SD) to 1.5 ± 0.2 sec (after 200 assessments), and assessments were consistently made in < 2.5 sec. Classifications should be reported with representative images allowing harmonization for quality control. This approach permits rapid classification and can be applied for the development of methods including the evaluation of vitrification solution components, concentrations of solutions a...
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Cryobanking of Aquatic Species
Aquaculture, 2017Co-Authors: Sonia Martínez-páramo, Ákos Horváth, Catherine Labbé, Tiantian Zhang, Vanesa Robles, Paz Herráez, Marc Suquet, Serean Adams, Ana Viveiros, Terrence R. TierschAbstract:This review is focused on the applications of genome cryobanking of Aquatic Species including freshwater and marine fish, as well as invertebrates. It also reviews the latest advances in cryobanking of model Species, widely used by the scientific community worldwide, because of their applications in several fields. The state of the art of cryopreservation of different cellular types (sperm, oocytes, embryos, somatic cells and primordial germ cells or early spermatogonia) is discussed focusing on the advantages and disadvantages of each procedure according to different applications. A special review on the need of standardization of protocols has also been carried out. In summary, this comprehensive review provides information on the practical details of applications of genome cryobanking in a range of Aquatic Species worldwide, including the cryobanks established in Europe, USA, Brazil, Australia and New Zealand, the Species and type of cells that constitute these banks and the utilization of the samples preserved.Statement of relevance: This review compiles the last advances on germplasm cryobanking of freshwater and marine fish Species and invertebrates, with high value for commercial aquaculture or conservation. It is reviewed the most promising cryopreservation protocols for different cell types, embryos and larvae that could be applied in programs for genetic improvement, broodstock management or conservation of stocks to guarantee culture production.
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Sources of variation in flow cytometric analysis of Aquatic Species sperm: The effect of cryoprotectants on flow cytometry scatter plots and subsequent population gating.
Aquaculture, 2012Co-Authors: Jonathan Daly, Terrence R. TierschAbstract:Abstract The use of fluorescent staining and flow cytometry to assess sperm quality in Aquatic Species has increased over the past decade, but comparisons among studies are difficult or impossible due to variation in application, analysis, and reporting of protocols and data. The goal of the present study was to determine the effect of exposure to two cryoprotectants commonly used for cryopreservation of sperm from Aquatic Species on the accuracy of flow cytometric assessment of sperm quality. Membrane integrity of zebrafish ( Danio rerio ) sperm exposed to 10% and 20% methanol and dimethyl sulfoxide (DMSO) in 300 mOsm kg − 1 Hanks' balanced salt solution (HBSS) or calcium-free HBSS was determined using SYBR 14/propidium iodide staining. Both cryoprotectants significantly affected forward-scatter and side-scatter characteristics of sperm samples, resulting in significant changes in the number of total and gated events, and in the number and percentage of intact cells. These results indicate that it cannot be assumed that the approach to flow cytometric analysis of fresh sperm will be applicable to cryoprotectant-treated or cryopreserved sperm. In total, we document examples of five potentially interacting factors that produce errors of 5 to 50% each, resulting in underestimates and overestimates of total and intact sperm (actual numbers and percentages) in the presence of the two most commonly used cryoprotectants at the concentrations used most often for cryopreservation of sperm from Aquatic Species. This study provides methods to reduce or eliminate these errors and recommendations necessary for standardization and reporting.
Janneke A. Hoekstra - One of the best experts on this subject based on the ideXlab platform.
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Variation in the sensitivity of Aquatic Species in relation to the classification of environmental pollutants
Chemosphere, 1997Co-Authors: Manon A. Vaal, Jan Tjalling Van Der Wal, Janneke A. Hoekstra, Joop L. M. HermensAbstract:Differences in Species sensitivity to toxicants can be substantial. In this study this among-Species variation in sensitivity was analyzed in relation to chemical's mode of action. Chemicals were classified as: non-polar narcotics, polar narcotics, reactive compounds and specifically acting compounds. Acute toxicity data of Aquatic Species were derived from the literature. Levels of enhanced toxicity, averaged over all Species, and interSpecies variation in sensitivity were analyzed for 35 chemicals, with data ranging from 12 to 62 Aquatic Species per compound. Non-polar and polar narcotic chemicals demonstrate the smallest variation in sensitivity and have levels of toxicity, which are highly predictable on the basis of their hydrophobicity. Reactive and specifically acting compounds can be much more toxic than predicted and variation in Species sensitivity can be as large as 10(5) to 10(6). In general, the larger this interSpecies variation the more asymmetric is the toxicity distribution due to extremely sensitive Species. Reactive and specifically acting compounds pose a potentially larger risk for Species in ecosystems than polar and non-polar narcotic compounds. They will need more testing to derive precisely equal estimates of safe environmental concentrations.
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Pattern analysis of the variation in the sensitivity of Aquatic Species to toxicants
Chemosphere, 1997Co-Authors: Manon A. Vaal, Jan Tjalling Van Der Wal, Joop L. M. Hermens, Janneke A. HoekstraAbstract:Abstract Our aim in this study was to identify groups of Species showing a similar pattern in their sensitivity to toxicants and to relate the patterns to the mode of toxic action and biological Species characteristics. A data matrix was composed of acute toxicity data for 26 Aquatic Species and 21 compounds. Most of the variation in the toxicological data was due to differences in toxicity of compounds and not intrinsic differences between Species, so that practically every Species can be used to order compounds with respect to average toxicity. Compounds with high overall toxicity also had large interSpecies variation in sensitivity. The toxicity of non-polar narcotics correlated well with the log K OW . Compounds with a specific or reactive mode of action were more than a factor 10 toxic than predicted by their log K OW . Patterns in Species sensitivity were more diffuse because only part of the variance in Species sensitivity could be explained. Fishes and amphibians were more sensitive to dieldrin, lindane and pentachlorophenol than were invertebrates. Among the arthropods, the Phyllopoda (daphnids) were the most sensitive Species. They were very sensitive to aniline, the heavy metals, malathion and parathion.
Murray A. Rudd - One of the best experts on this subject based on the ideXlab platform.
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Non-use Economic Values for Little-Known Aquatic Species at Risk: Comparing Choice Experiment Results from Surveys Focused on Species, Guilds, and Ecosystems
Environmental Management, 2016Co-Authors: Murray A. Rudd, Sheri Andres, Mary KilfoilAbstract:Accounting for non-market economic values of biological diversity is important to fully assess the benefits of environmental policies and regulations. This study used three choice experiments (Species-, guild-, and ecosystem-based surveys) in parallel to quantify non-use values for little-known Aquatic Species at risk in southern Ontario. Mean willingness-to-pay (WTP) ranged from $9.45 to $21.41 per listing status increment under Canada’s Species at Risk Act for both named and unnamed little-known Species. Given the broad range of valuable ecosystem services likely to accrue to residents from substantial increases in water quality and the rehabilitation of coastal wetlands, the difference in WTP between Species- and ecosystem-based surveys seemed implausibly small. It appeared that naming Species—the ‘iconization’ of Species in two of the three surveys—had an important effect on WTP. The results suggest that reasonable annual household-level WTP values for little-known Aquatic Species may be $10 to $25 per Species or $10 to $20 per listing status increment. The results highlighted the utility of using parallel surveys to triangulate on non-use economic values for little-known Species at risk.
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National values for regional Aquatic Species at risk in Canada
Endangered Species Research, 2009Co-Authors: Murray A. RuddAbstract:The goal of the present analysis was to assess the geographic scope and magnitude of non-market values for 6 regional Aquatic Species listed, or being considered for listing, as endan- gered under the Canadian Species at Risk Act. I used latent class analysis to partition responses from a national Internet-based survey that asked respondents about their preferred conservation program from amongst scenarios that varied according to target Species (Atlantic salmon Salmo salar, Atlantic whitefish Coregonus huntsmani, leatherback turtle Dermochelys coriacea, North Atlantic right whale Eubalaena glacialis, porbeagle shark Lamna nasus, and white sturgeon Acipenser transmontanus), program performance, cost, and method of payment. The large sample of the Canadian public (n = 2761) cleaved into 9 distinct segments that varied significantly in their patterns of preferences. Mean implicit prices, calculated using regression coefficients, ranged as high as CAD $85.99 annually for Atlantic salmon Salmo salar. There was strong support for programs that had a high probability of success even though increases in population abundance and improvements in listing status were each only significant for 4 of the 9 segments. I also found evidence that members of 1 segment were unwilling or unable to make tradeoffs between the program attributes (i.e. they exhibited 'lexico- graphic preferences'). Members from all 9 segments were distributed across Canada, implying that the proper geographic scope of benefits assessments should be expanded beyond the regions in which regional Aquatic Species at risk actually occur. These findings should help ensure that the broad societal benefits of conservation are captured when making endangered Species listing and investment decisions in Canada in the future.
Joop L. M. Hermens - One of the best experts on this subject based on the ideXlab platform.
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Variation in the sensitivity of Aquatic Species in relation to the classification of environmental pollutants
Chemosphere, 1997Co-Authors: Manon A. Vaal, Jan Tjalling Van Der Wal, Janneke A. Hoekstra, Joop L. M. HermensAbstract:Differences in Species sensitivity to toxicants can be substantial. In this study this among-Species variation in sensitivity was analyzed in relation to chemical's mode of action. Chemicals were classified as: non-polar narcotics, polar narcotics, reactive compounds and specifically acting compounds. Acute toxicity data of Aquatic Species were derived from the literature. Levels of enhanced toxicity, averaged over all Species, and interSpecies variation in sensitivity were analyzed for 35 chemicals, with data ranging from 12 to 62 Aquatic Species per compound. Non-polar and polar narcotic chemicals demonstrate the smallest variation in sensitivity and have levels of toxicity, which are highly predictable on the basis of their hydrophobicity. Reactive and specifically acting compounds can be much more toxic than predicted and variation in Species sensitivity can be as large as 10(5) to 10(6). In general, the larger this interSpecies variation the more asymmetric is the toxicity distribution due to extremely sensitive Species. Reactive and specifically acting compounds pose a potentially larger risk for Species in ecosystems than polar and non-polar narcotic compounds. They will need more testing to derive precisely equal estimates of safe environmental concentrations.
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Pattern analysis of the variation in the sensitivity of Aquatic Species to toxicants
Chemosphere, 1997Co-Authors: Manon A. Vaal, Jan Tjalling Van Der Wal, Joop L. M. Hermens, Janneke A. HoekstraAbstract:Abstract Our aim in this study was to identify groups of Species showing a similar pattern in their sensitivity to toxicants and to relate the patterns to the mode of toxic action and biological Species characteristics. A data matrix was composed of acute toxicity data for 26 Aquatic Species and 21 compounds. Most of the variation in the toxicological data was due to differences in toxicity of compounds and not intrinsic differences between Species, so that practically every Species can be used to order compounds with respect to average toxicity. Compounds with high overall toxicity also had large interSpecies variation in sensitivity. The toxicity of non-polar narcotics correlated well with the log K OW . Compounds with a specific or reactive mode of action were more than a factor 10 toxic than predicted by their log K OW . Patterns in Species sensitivity were more diffuse because only part of the variance in Species sensitivity could be explained. Fishes and amphibians were more sensitive to dieldrin, lindane and pentachlorophenol than were invertebrates. Among the arthropods, the Phyllopoda (daphnids) were the most sensitive Species. They were very sensitive to aniline, the heavy metals, malathion and parathion.
Manon A. Vaal - One of the best experts on this subject based on the ideXlab platform.
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Variation in the sensitivity of Aquatic Species in relation to the classification of environmental pollutants
Chemosphere, 1997Co-Authors: Manon A. Vaal, Jan Tjalling Van Der Wal, Janneke A. Hoekstra, Joop L. M. HermensAbstract:Differences in Species sensitivity to toxicants can be substantial. In this study this among-Species variation in sensitivity was analyzed in relation to chemical's mode of action. Chemicals were classified as: non-polar narcotics, polar narcotics, reactive compounds and specifically acting compounds. Acute toxicity data of Aquatic Species were derived from the literature. Levels of enhanced toxicity, averaged over all Species, and interSpecies variation in sensitivity were analyzed for 35 chemicals, with data ranging from 12 to 62 Aquatic Species per compound. Non-polar and polar narcotic chemicals demonstrate the smallest variation in sensitivity and have levels of toxicity, which are highly predictable on the basis of their hydrophobicity. Reactive and specifically acting compounds can be much more toxic than predicted and variation in Species sensitivity can be as large as 10(5) to 10(6). In general, the larger this interSpecies variation the more asymmetric is the toxicity distribution due to extremely sensitive Species. Reactive and specifically acting compounds pose a potentially larger risk for Species in ecosystems than polar and non-polar narcotic compounds. They will need more testing to derive precisely equal estimates of safe environmental concentrations.
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Pattern analysis of the variation in the sensitivity of Aquatic Species to toxicants
Chemosphere, 1997Co-Authors: Manon A. Vaal, Jan Tjalling Van Der Wal, Joop L. M. Hermens, Janneke A. HoekstraAbstract:Abstract Our aim in this study was to identify groups of Species showing a similar pattern in their sensitivity to toxicants and to relate the patterns to the mode of toxic action and biological Species characteristics. A data matrix was composed of acute toxicity data for 26 Aquatic Species and 21 compounds. Most of the variation in the toxicological data was due to differences in toxicity of compounds and not intrinsic differences between Species, so that practically every Species can be used to order compounds with respect to average toxicity. Compounds with high overall toxicity also had large interSpecies variation in sensitivity. The toxicity of non-polar narcotics correlated well with the log K OW . Compounds with a specific or reactive mode of action were more than a factor 10 toxic than predicted by their log K OW . Patterns in Species sensitivity were more diffuse because only part of the variance in Species sensitivity could be explained. Fishes and amphibians were more sensitive to dieldrin, lindane and pentachlorophenol than were invertebrates. Among the arthropods, the Phyllopoda (daphnids) were the most sensitive Species. They were very sensitive to aniline, the heavy metals, malathion and parathion.