3,609 research outputs found
Ambient ammonia measurements using laser photo-acoustic spectroscopy
Ammonia concentrations reached minimal levels (approximately 0.1 ppb) in early winter, followed by a sudden later winter increase. A direct relationship between ambient ammonia levels and air temperature was inferred from the data (linear correlation coefficient r=0.53). Ammonia concentrations were determined to be directly related to the absolute humidity of the air (r=0.72); a weaker relationship between ammonia concentrations and relative humidity was discovered (r=0.37). The data also indicated that ammonia levels were generally higher within continental air masses than those of maritime origin. Soil parameters such as pH and moisture content were found to have a major bearing on the release of gaseous ammonia from soils in the region
Microencapsulated diets to improve bivalve shellfish aquaculture.
Aquaculture is the fastest growing food sector and feeds over 3 billion people. Bivalve shellfish aquaculture makes up 25% of global aquaculture production and is worth annually US$19 billion, but continued growth is currently limited by suboptimal diets and limited tools for disease control. New advances in microencapsulation technology could provide an effective way to overcome these biological limitations. This study demonstrated that a new formulation of microencapsulated diet known as BioBullets could be ingested by a commercially farmed bivalve; the blue mussel Mytilus edulis. Microparticles could be captured by mussels with similar efficiency to natural foods. Microparticles too large for ingestion were rejected in pseudofaeces. Microparticles were successfully ingested and broken down by the gut. Further work is needed to assess the impact of BioBullets diets on bivalve growth. There is now an exciting opportunity to tailor the composition of microencapsulated diets for specific applications to improve production output and efficiency in the commercial bivalve shellfish industry
Recommended from our members
Microencapsulated diets to improve growth and survivorship in juvenile European flat oysters (Ostrea edulis).
Sustainable expansion of aquaculture is critical to global food security, and bivalve shellfish aquaculture represents a sustainable method to provide people with affordable nutritious food. Oysters represent 54% of the global bivalve market by value, with propagation of juveniles within hatcheries critical to allow the industry to grow. Growth and survival of juvenile oysters in hatchery systems is constrained by suboptimal feed. The live algal feed currently used is expensive, of variable quality, contamination prone, and the high level of skill and equipment required limits where hatcheries can be located. We demonstrate how a novel microencapsulated diet can increase the growth and survivorship of Ostrea edulis (European flat oyster) juveniles in both the laboratory and hatchery setting. The microcapsules are easily produced in large quantities, stable for long term storage, and can be customised to have exceptionally high levels of nutrients key for oyster growth. O. edulis larvae fed a combined diet of microcapsules and algae for 8 days had a 46% greater increase in maximum size, 171% greater increase in minimum size, and 5% higher survival than larvae fed algae alone. O. edulis spat of 4 mm fed the combined diet for 7 weeks also had significantly greater survivorship (16% greater in hatchery, 58% greater in laboratory) and growth comparable (hatchery) or better (laboratory experiments) than algae alone. Further tailoring of the nutritional composition of microcapsules to specific bivalve species or growth stages could allow microcapsules to replace a greater proportion of or even completely replace algal diets. There is potential for these diets to revolutionise bivalve shellfish farming globally
Historical evolution of the extraordinary item concept
The notion of extraordinary items has been clearly defined since the Accounting Principles Board issued Reporting the Results of Operations, Opinions of the Accounting Principles Board No. 30 in 1973. The opinion established the criteria of infrequency and unusualness for extraordinary item treatment. In addition, the opinion discussed the proper presentation of extraordinary items in an income statement format. Although extraordinary item treatment is a well-understood concept, little has been written about the forces and developments that led to the issuance of Opinion No. 30. The purpose of this paper is to review the historical developments that led to the evolution of the extraordinary item concept
Recommended from our members
Vitamin Bullets. Microencapsulated Feeds to Fortify Shellfish and Tackle Human Nutrient Deficiencies
Over two billion people worldwide are micronutrient deficient, with regionally specific deficiencies. Fortification of food with micronutrients has become an industry standard for enhancing public health. Bivalve shellfish (e.g., oysters, clams, and mussels) provide the most sustainable source of animal protein on the planet, and the market is rapidly growing—with production in China increasing 1,000-fold since 1980 to an annual 36 kg capita−1 consumption level. Bivalves are also unique in that micronutrients consumed at their end-life stage will be digested by humans, as humans consume the entire organism including the gut. We have developed a novel microencapsulated vehicle for delivering micronutrients to bivalves, tailored for optimal size, shape, buoyancy, and palatability, demonstrating the potential of fortified bivalves to tackle human nutrient deficiencies. Oysters fed vitamin A and D microcapsules at a 3% initial dosage for just 8 h had elevated tissue vitamin content. A serving of just two such bivalves provides enough vitamin A and D to meet human dietary RDAs. Scale-up of this technology and application to other bivalve species including clams and mussels could provide a low-cost and highly sustainable mechanism to contribute toward tackling nutrient deficiencies globally
The Importance of the Human Footprint in Shaping the Global Distribution of Terrestrial, Freshwater and Marine Invaders
Human activities such as transport, trade and tourism are likely to influence the spatial distribution of non-native species and yet, Species Distribution Models (SDMs) that aim to predict the future broad scale distribution of invaders often rely on environmental (e.g. climatic) information only. This study investigates if and to what extent do human activities that directly or indirectly influence nature (hereafter the human footprint) affect the global distribution of invasive species in terrestrial, freshwater and marine ecosystems. We selected 72 species including terrestrial plants, terrestrial animals, freshwater and marine invasive species of concern in a focus area located in NW Europe (encompassing Great Britain, France, The Netherlands and Belgium). Species Distribution Models were calibrated with the global occurrence of species and a set of high-resolution (9×9 km) environmental (e.g. topography, climate, geology) layers and human footprint proxies (e.g. the human influence index, population density, road proximity). Our analyses suggest that the global occurrence of a wide range of invaders is primarily limited by climate. Temperature tolerance was the most important factor and explained on average 42% of species distribution. Nevertheless, factors related to the human footprint explained a substantial amount (23% on average) of species distributions. When global models were projected into the focus area, spatial predictions integrating the human footprint featured the highest cumulative risk scores close to transport networks (proxy for invasion pathways) and in habitats with a high human influence index (proxy for propagule pressure). We conclude that human related information–currently available in the form of easily accessible maps and databases—should be routinely implemented into predictive frameworks to inform upon policies to prevent and manage invasions. Otherwise we might be seriously underestimating the species and areas under highest risk of future invasions.The first author would like to thank the constructive comments and advice on the manuscript made by Drs Montserrat Vilà , Juan Pedro González-Varo and Pablo González-Moreno.Peer reviewe
Making the best of a pest: the potential for using invasive zebra mussel (Dreissena polymorpha) biomass as a supplement to commercial chicken feed.
Invasive non-native species frequently occur in very high densities. When such invaders present an economic or ecological nuisance, this biomass is typically removed and landfill is the most common destination, which is undesirable from both an economic and ecological perspective. The zebra mussel, Dreissena polymorpha, has invaded large parts of Europe and North America, and is routinely removed from raw water systems where it creates a biofouling nuisance. We investigated the suitability of dried, whole zebra mussels as a supplement to poultry feed, thus providing a more attractive end-use than disposal to landfill. Measurable outcomes were nutrient and energy composition analyses of the feeds and production parameters of the birds over a 14 day period. Zebra mussels were a palatable feed supplement for chickens. The mussel meal contained high levels of calcium (344.9 g kg(-1)), essential for egg shell formation, which was absorbed and retained easily by the birds. Compared with standard feed, a mussel-supplemented diet caused no significant effects on production parameters such as egg weight and feed conversion ratio during the study period. However, protein and energy levels in the zebra mussel feed were much lower than expected from the literature. In order for zebra mussels to be a viable long-term feed supplement for poultry, flesh would need to be separated from the shells in an economically viable way. If zebra mussels were to be used with the shells remaining, it seems that the resultant mussel meal would be more suitable as a calcium supplement.This research project was funded through a Natural Environment Research Council CASE studentship to CM and DCA grant number [NE/H018697/1] in partnership with Anglian Water.This is the final published version. It's also available from Springer at http://link.springer.com/article/10.1007%2Fs00267-014-0335-6
Correlation and prediction of dynamic human isolated joint strength from lean body mass
A relationship between a person's lean body mass and the amount of maximum torque that can be produced with each isolated joint of the upper extremity was investigated. The maximum dynamic isolated joint torque (upper extremity) on 14 subjects was collected using a dynamometer multi-joint testing unit. These data were reduced to a table of coefficients of second degree polynomials, computed using a least squares regression method. All the coefficients were then organized into look-up tables, a compact and convenient storage/retrieval mechanism for the data set. Data from each joint, direction and velocity, were normalized with respect to that joint's average and merged into files (one for each curve for a particular joint). Regression was performed on each one of these files to derive a table of normalized population curve coefficients for each joint axis, direction, and velocity. In addition, a regression table which included all upper extremity joints was built which related average torque to lean body mass for an individual. These two tables are the basis of the regression model which allows the prediction of dynamic isolated joint torques from an individual's lean body mass
Fouling of European freshwater bivalves (Unionidae) by the invasive zebra mussel (Dreissena polymorpha)
1. The zebra mussel (Dreissena polymorpha) is well known for its invasive success and its
ecological and economic impacts. Of particular concern has been the regional extinction of
North American freshwater mussels (Order Unionoida) on whose exposed shells the zebra
mussels settle. Surprisingly, relatively little attention has been given to the fouling of
European unionoids.
2. We investigated interspecific patterns in fouling at six United Kingdom localities
between 1998 and 2008. To quantify the effect on two pan-European unionoids (Anodonta
anatina and Unio pictorum), we used two measures of physiological status: tissue
mass : shell mass and tissue glycogen content.
3. The proportion of fouled mussels increased between 1998 and 2008, reflecting the recent,
rapid increase in zebra mussels in the U.K. Anodonta anatina was consistently more heavily
fouled than U. pictorum and had a greater surface area of shell exposed in the water
column.
4. Fouled mussels had a lower physiological condition than unfouled mussels. Unlike
tissue mass : shell mass ratio, tissue glycogen content was independent of mussel size,
making it a particularly useful measure of condition. Unio pictorum showed a stronger
decline in glycogen with increasing zebra mussel load, but had a broadly higher condition
than A. anatina at the time of study (July).
5. Given the high conservation status and important ecological roles of unionoids, the
increased spatial distribution and fouling rates by D. polymorpha in Europe should receive
more attention.Malacological Society of London Research Grant was provided to FP to support this study. Howard Baylis and Barrie Fuller (Zoology Department, University of Cambridge) facilitated the glycogen assays. Many thanks to Philine zu Ermgassen, Rebecca Mant, Anna McIvor, Nicole Spann and Alexandra Zieritz for field and lab assistance. Special thanks to David Strayer, Alan Hildrew and an anonymous referee for helpful suggestions on the manuscript
- …