Coordination polymers of osmium: the nature of osmium black

The design of cytochemical reagents that yield osmiophilic products from which an osmium black may be derived on exposure to osmium tetroxide has resulted in new methods described previously for the ultrastructural demonstration of enzyme activity and functional groups of macromolecules with the electron microscope. Attempts to determine the nature of the osmium black end products have been frustrated by their insolubility. The preparation of watersoluble analogs and their characterization as polymers suggest that the insoluble osmium blacks are coordination polymers. This is consonant with the unusually favorable properties of osmium black in electron microscopy. Although polymers of osmium have frequently been postulated as the end products of reaction of osmium tetroxide with tissue conistituents or with other organic compounds, this is the first example of their characterization.     

Effect of repeated heating and cooling cycles on the pasting properties of starch

The properties of starch and starch–lipid pastes have been explored using a novel extended Rapid Visco Analyser (RVA) profile, in which the heating and cooling cycles are repeated five times. Starches from four wheat varieties with amylose content ranging from 23 to 27%, and waxy starches of wheat, rice and maize were tested, alone and in mixtures with lauric acid and monopalmitin (glyceryl-1-monopalmitin). Gels of all of the starches formed and melted reproducibly during repeated heating and cooling in the RVA. The addition of lauric acid to the waxy starches had no effect on the multiple RVA profile. Monopalmitin caused an increase in viscosity during the heating stage of the second to the fifth cycles with the waxy starches, which was attributed to the presence of monopalmitin aggregates. Changes in the multiple cycle viscosity traces observed when monopalmitin or lauric acid was added to the amylose-containing starches were complex. It was concluded that RVA paste viscosities were determined by starch–lipid interactions, as well as by free lipid in the starch mixtures. The water solubility of the lipid and association of proteins with starch granules influence these interactions.     

Effects of Soil Type and Tillage on Protein and Starch Quality in Three Related Wheat Genotypes

An experiment was conducted using three related wheat (Triticum aestivum L.) genotypes grown on two different soil types (a grey vertosol and a red kandosol) using two different tillage practices (complete and zero) to test the effects of environmental influence on grain quality. Wheat grains from plants grown in each environment were milled into flour; protein and starch were analyzed. The soil type had the biggest impact on both protein and starch content, with the grains from the grey vertosol soil having higher total, insoluble, and soluble protein contents, and lower starch content and flour swelling values. When protein was analyzed using SDS‐PAGE, the major difference observed between grains from the two soil types was an increased intensity of polypeptide bands corresponding to β‐amylase in grains from plants grown on grey vertosol soils.     

Genotype and Environmental Influences on Pasting Properties of Rice Flour

The pasting behavior of flour from several Australian rice (Oryza sativa L.) cultivars, differing in amylose content and grown in three different locations and three seasons, were determined using the Rapid Visco Analyser. Genotype, growth season, and growth location all affected the pasting behavior of rice flour. The amylose content of the same cultivar was significantly higher in the coolest growing season, resulting in RVA traces with lower peak viscosity and higher setback than samples with lower amylose content. When the same cultivar of rice was grown in different locations in the same season, there were no significant differences in the total starch, protein, lipid, and amylose content of the flour, but there were significant differences in the pasting behavior. This indicates that environmental as well as genetic factors influence the pasting behavior of rice flour. Flour from parboiled and quick‐cooking rice did not paste and had low viscosities compared with unprocessed rice. Results from this study showed that the pasting behavior of rice flour was related to genotype and was influenced by environmental factors that brought about subtle changes in the grains that were not picked up by chemical analyses.     

Economic Evaluation of a Small-Scale Recirculating System for Ongrowing of Captive Wild Black Sea Bass Centropristis striata in North Carolina

An economic analysis of a hypothetical small‐scale marine recirculating aquaculture system (RAS) is conducted for ongrowing small, wild black sea bass Centropristis striata at the University of North Carolina Wilmington, Center for Marine Science (UNCW‐CMS) aquaculture facility in Wrightsville Beach, North Carolina (NC). The analysis is based on production data from field trials and marketing data from the sale of tank‐grown product. The growout facility consists of four 16.7‐m³ (dia. x ht. = 5.58 × 1 m) fiberglass tanks supported by state‐of‐the‐art RAS components, including particle traps and swirl separators, drum screen filter, trickling biological filter, UV sterilizer, heat pump, protein skimmer, and oxygen cone. Wild‐caught, above minimum legal size black sea bass (24.2 cm TL, 350 g, 0.77 lb) were purchased from a commercial fisherman for $3.14/ kg ($1.4011b), stocked at a density of 21.1 kg/m³, and grown to a final weight of 1 kg (2.24 lb) in 200 d at 23 C resulting in 1.8 production cycles per year. Fish were fed a commercial pelleted diet ($0.94/kg; $0.42/Ib) with a feed conversion ratio of 1.5. Final harvest density was 60 kg/m³ (0.50 lb/gal), and total harvestable weight was 3,982 kg (8,919 Ibs) of fish per cycle, or 6,760 kg (15,022 lb) per year. The economic analysis assumes that the facility owner manages and operates the system on coastal property zoned commercial/industrial, where full strength seawater is available on demand from natural sources. Under the base case scenario, initial investment in construction and equipment is $84,506 (10‐yr life), fish are grown to a harvestable weight of lkg/fish (2.24 lb/fish), product price (farm gate basis) is $10.10/kg ($4.50/lb), and breakeven price is $7.02/kg ($3.13/lb). Depreciation, fingerlings, interest paid, electricity, and feed, account for 19.6%,17.4%, 16.9%, 16.6%, and 12.3%, respectively, of total annual costs. Measures of financial performance for the base case, 10‐yr scenario are: annual return to management, $18,819; net present value (5% discount rate), $145,313; internal rate of return on initial investment, 37%; and discounted payback period on initial investment, 3.2 yr. Sensitivity analysis showed that product price changes have the largest impact on annual returns, while changes in daily growth rate, initial weight, and survival have a strong impact on financial performance. Moderate effects are seen with changes in fingerling costs, feed costs, feed conversion ratio (FCR), final weight, and interest rates.     

Onset and progression in inherited ALS determined by motor neurons and microglia

Dominant mutations in superoxide dismutase cause amyotrophic lateral sclerosis (ALS), a progressive paralytic disease characterized by loss of motor neurons. With the use of mice carrying a deletable mutant gene, expression within motor neurons was shown to be a primary determinant of disease onset and of an early phase of disease progression. Diminishing the mutant levels in microglia had little effect on the early disease phase but sharply slowed later disease progression. Onset and progression thus represent distinct disease phases defined by mutant action within different cell types to generate non-cell-autonomous killing of motor neurons; these findings validate therapies, including cell replacement, targeted to the non-neuronal cells.     

Amylolysis of wheat starches. II. Degradation patterns of native starch granules with varying functional properties

Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to investigate degradation patterns of native starch granules from wheat (Triticum aestivum L.) by different starch-degrading enzymes. The starches examined were from a waxy wheat and four varieties with slightly elevated amylose content, but with different functional properties. Differences in the digestion patterns after partial α-amylolysis of starch granules were noted between the starches. The waxy starch seemed to be degraded by endocorrosion, whereas the amylose-rich starches followed a slower mode of hydrolysis starting from the granular surface. X-ray diffractograms of the amylose-rich starches were not significantly altered by 2 h of α-amylolysis, whereas partial hydrolysis of the waxy starch decreased scattering intensity at higher 2θ angles, consistent with a different mode of attack by α-amylase in the initial digestion stages of granules of waxy and amylose-rich starches. We propose these differences are due to the combined effects of the change in packing density and partial preference for hydrolysis of amorphous material. The native starch granules were also attacked by beta-amylase, isoamylase and amyloglucosidase, which indicates that α-amylase is not the only starch-degrading enzyme that is able to initiate starch hydrolysis of native granules.     

China's distant‐water fisheries in the 21st century

We conservatively estimate the distant‐water fleet catch of the People's Republic of China for 2000–2011, using a newly assembled database of reported occurrence of Chinese fishing vessels in various parts of the world and information on the annual catch by vessel type. Given the unreliability of official statistics, uncertainty of results was estimated through a regionally stratified Monte Carlo approach, which documents the presence and number of Chinese vessels in Exclusive Economic Zones and then multiplies these by the expected annual catch per vessel. We find that China, which over‐reports its domestic catch, substantially under‐reports the catch of its distant‐water fleets. This catch, estimated at 4.6 million t year^?1 (95% central distribution, 3.4–6.1 million t year^?1) from 2000 to 2011 (compared with an average of 368 000 t·year^?1 reported by China to FAO), corresponds to an ex‐vessel landed value of 8.93 billion € year^?1 (95% central distribution, 6.3–12.3 billion). Chinese distant‐water fleets extract the largest catch in African waters (3.1 million t year^?1, 95% central distribution, 2.0–4.4 million t), followed by Asia (1.0 million t year^?1, 0.56–1.5 million t), Oceania (198 000 t year^?1, 144 000–262 000 t), Central and South America (182 000 t year^?1, 94 000–299 000 t) and Antarctica (48 000 t year^?1, 8 000–129 000 t). The uncertainty of these estimates is relatively high, but several sources of inaccuracy could not be fully resolved given the constraints inherent in the underlying data and method, which also prevented us from distinguishing between legal and illegal catch.