Fish Offal Recycling by the Black Soldier Fly Produces a Foodstuff High in Omega-3 Fatty Acids

Abstract.— The black soldier fly, Hermetia illucens , has the potential to reduce animal waste on livestock facilities and produce an animal-grade feedstuff high in protein and fat. The lipid content of insects is largely dependent on their diet. Data from this study suggest that black soldier fly prepupae incorporate α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) when fish offal is included in their diet. Fly larvae were fed three different proportions of fish offal and cow manure diets over a 21-d trial. An additional group of larvae were fed 22% fish offal diet within 24 h of their pupation. Larvae fed fish offal were, on average, 30% lipid, which was 43% more than the controls fed cow manure only, and approximately 3% of this lipid was omega-3 fatty acids (EPA, DHA, and ALA). Furthermore, this concentration of omega-3 fatty acids was achieved within 24 h of feeding fish offal. These omega-3 fatty-acid-enhanced prepupae may be a suitable fish meal and fish oil replacement for carnivorous fish and other animal diets. In addition, they may provide a method of reducing and recycling fish offal from processing plants.     

Does Age Matter? The Influence of Age on Response Rates in a Mixed-Mode Survey

The appeal of cost savings and faster results has fish and wildlife management agencies considering the use of Internet surveys instead of traditional mail surveys to collect information from their constituents. Internet surveys, however, may suffer from differential age-related response rates, potentially producing biased results if certain age groups respond to Internet surveys differently than they do to mail surveys. We examined this concern using data from a mixed-mode angler survey conducted in South Dakota following the 2011 fishing season. Results indicated that young anglers (16–18) had the lowest return rates and senior anglers (65+) had the highest, regardless of survey mode. Despite this consistency in response rates, we note two concerns: (a) lower Internet response rates and (b) different age groups represented by the Internet and mail survey samples differed dramatically. Findings indicate that constituent groups may be represented differently with the use of various survey modes.     

Medicine. Stroke--tPA and the clinic

Clinical trial results are not always rapidly incorporated into routine medical practice. This Policy Forum describes a variety of barriers that have impeded the more widespread use of thrombolytic therapy (tPA, tissue plasminogen activator) for selected patients with acute ischemic stroke. These barriers are not insurmountable but will require a concerted effort to overcome.     

Southern Ocean iron enrichment experiment: carbon cycling in high- and low-Si waters

The availability of iron is known to exert a controlling influence on biological productivity in surface waters over large areas of the ocean and may have been an important factor in the variation of the concentration of atmospheric carbon dioxide over glacial cycles. The effect of iron in the Southern Ocean is particularly important because of its large area and abundant nitrate, yet iron-enhanced growth of phytoplankton may be differentially expressed between waters with high silicic acid in the south and low silicic acid in the north, where diatom growth may be limited by both silicic acid and iron. Two mesoscale experiments, designed to investigate the effects of iron enrichment in regions with high and low concentrations of silicic acid, were performed in the Southern Ocean. These experiments demonstrate iron's pivotal role in controlling carbon uptake and regulating atmospheric partial pressure of carbon dioxide.     

Oxytocin, vasopressin, and the neurogenetics of sociality

There is growing evidence that the neuropeptides oxytocin and vasopressin modulate complex social behavior and social cognition. These ancient neuropeptides display a marked conservation in gene structure and expression, yet diversity in the genetic regulation of their receptors seems to underlie natural variation in social behavior, both between and within species. Human studies are beginning to explore the roles of these neuropeptides in social cognition and behavior and suggest that variation in the genes encoding their receptors may contribute to variation in human social behavior by altering brain function. Understanding the neurobiology and neurogenetics of social cognition and behavior has important implications, both clinically and for society.     

Electrolyte leakage of aging potato tubers and its relationship with sprouting capacity

Summary With advancing physiological age of potato tubers an increase in electrolyte leakage from tuber tissue was observed for various seed lots. This increase was most marked after tubers exhibited sprout growth and corresponded with a decline in tuber water content. Leakage increased minimally with storage time when sprouting was prevented or limited by either dormancy, low storage temperature, or frequent desprouting. Sprouting capacity of tubers increased to a maximum and then declined with storage time. This decline coincided with the increase in electrolyte leakage, suggesting that membrane integrity was one determinant in vigour of seed potato tubers. The pattern of electrolytes leaking from tuber tissue could be described by a function composed of a saturable and a linear component, suggesting two different sources contributing to the leakage. The saturable component, expected to reflect membrane integrity, was most responsive to aging treatments. H/LA Paper No. 93-13. Department of Horticulture and Landscape Architecture, Project No. 1984. College of Agriculture and Home Economics Research Center, Washington State University. This work was supported in part by grant funding from the Washington State Potato Commission.     

Evaluation of on-farm irrigation scheduling methods for potatoes

The neutron probe, infrared thermometry and crop water stress index (CWSI), and a computer-assisted irrigation scheduling method were evaluated in terms of their effect on tuber yield, tuber quality, and water use. The experiment was conducted during 1990 and 1991 near Othello, central Washington, using Russet Burbank potatoes grown in a silt loam soil. Irrigation treatments did not commence until after tuber initiation. In general, no differences in total number of tubers and total tuber yield resulted from the different scheduling methods. However, the canopy temperature method showed reduction in the yield of number one tubers in 1990. The least total irrigation water was applied during the growing season with the neutron probe method. Using CWSI values above 0.5 to 1.0 (scale 0 to 10) for two consecutive days as a threshold to schedule irrigations appeared to be adequate for potatoes grown in silt loam soils. However, shortcomings of infrared thermometry suggested that this method may not be practical for scheduling irrigation of potatoes.     

THE EFFECT OF DEFOLIATION ON THE SEED-PRODUCING CAPACITY OF BRED STRAINS OF GRASSES

A leafy strain of timothy and of perennial ryegrass showed no significant reductions in seed yields following grazing at different dates from October to January, when extra nitrogen was applied.
Spring and winter + spring grazing, together with extra nitrogen, significantly reduced the seed yield of S50 timothy for three successive harvest years.
Perennial ryegrass S101 showed no reduction after spring or winter + spring grazing when defoliation was made not later than mid-April, but when grazing was delayed until May and drought occurred there was a significant reduction in seed yield.