Amino acid composition of freshly harvested and stored potatoes

Total amino acid contents of several important U.S. potato cultivars grown in Maine, Idaho and The Red River Valley are listed along with nitrogen content. Differences in amino acid content among cultivars were roughly proportional to differences in total nitrogen. The effect of storage on amino acids in two cultivars was minor. The limiting essential amino acids compared to egg were MET and the sulphur amino acids.     

Mutation breeding for yield andPhytophthora infestans (Mont.) de Bary foliar resistance in potato (Solanum tuberosum L. cv. Golden Wonder) using computerized image analysis in selection

Summary Using visual selection for off-types and image analysis to select against maturation mutants, a line combining improved late blight resistance and yield was isolated in an in vitro mutagenesis programme from a population of 2101 putative mutants. The adventitious regenerants from mutagenesis treatment, including spontaneous mutants (somaclonal variants), were subjected to serial subculture of the apical bud in vitro and two cycles of apical cuttings in vivo to breakdown chimeras. The selected line was stable in trials over five years; others were unstable or failed to combine improvement in late blight resistance with high yield. Leaf and tuber image analysis was used to characterize selected lines. Lines that differed most from cv. Golden Wonder in yield and late blight resistance were more easily distinguished from the control by image analysis. The role of image analysis in negative selection and in determination of the relatedness of mutants to the control is discussed.     

Studies on composite filaments from nanoclay reinforced polypropylene

The development of high tenacity, high modulus monofilaments from Polypropylene/Clay nanocomposite has been investigated. Pure sodium montmorillonite nanoclay was modified using hexadecyl trimethyl ammonium bromide (HTAB) via an ion exchange reaction. Pure and modified clay were characterized through X-ray diffraction, FTIR and TGA. The modified clay was melt blended with polypropylene (PP) in presence of a swelling agent. Composite filaments from PP/Clay nanocomposite were prepared at different weight percentages of nanoclay and the spinning and drawing conditions were optimized. The filaments were characterized for their mechanical, morphological and thermal properties. The composite PP filaments with modified clay showed improved tensile strength, modulus and reduced elongation at break. The composite filaments with unmodified clay did not show any improvement in tensile strength but the modulus improved. The sharp and narrow X-ray diffraction peaks of PP/nanoclay composite filaments indicate increase in crystallinity in presence of modified clay at small loadings (0.5%). The improved thermal stability was observed in filaments with modified as well as unmodified clays.     

Histopathology of abnormal livers and other organs of starry flounder Platichthys stellatus (Pallas) from the estuary of the Duwamish River, Seattle, Washington, U.S.A.

Abstract. Starry flounder Platichthys stellatus (Pallas) from the Duwamish River estuary, which has received large volumes of pollutants in the past, and starry flounder from two relatively unpolluted reference areas were examined for pathological conditions. Gross and microscopic examination of starry flounders from the Duwamish River estuary revealed one or more of the following unusual liver characteristics in 92% (monthly range 85–100%) of the fish: liver discolouration, liver enlargement, severe fatty vacuolation of the hepatocytes, centrolobular cellular degeneration and necrosis of hepatocytes, megalocytic hepatocytes, proliferating perivascular fibroblasts displacing adjacent liver parenchyma, hepatic structural disarray and increased basophilia of hepatocytes in localized areas. Livers of starry flounders, usually spent spawners, from one of the reference areas also had one or more of these characteristics, although at a much lower frequency (<13%), and these included liver discolouration, increased fatty vacuolation of the hepatocytes and hepatic structural disarray.     

Influence of enteric helminths on the distribution of intestinal endocrine cells belonging to the diffuse endocrine system in brown trout,Salmo trutta L

The presence of intestinal helminths in the alimentary canal of brown trout, Salmo trutta L., can alter the number of cells that synthesize modulatory peptides. A total of 167 brown trout were collected from tributaries of the River Brenta (northern Italy), of which 119 (71.3%) specimens were infected with enteric helminths, 28 with the acanthocephalan Pomphorhynchus laevis Müller, 1776 with intensity of infection ranging from 1 to 162 (18.57 +/- 30.79) worms per host and 67 fish with the cestode Cyathocephalus truncatus Pallas, 1781. Intensity of infection with C. truncatus ranged from 1 to 85 (6.87 +/- 12.59) per fish. In 24 fish there were concurrent infections of both species of helminths. The caecal and middle regions of the intestine were the most heavily parasitized. Immunohistochemical tests showed a decrease in endocrine cells (ECs) of the diffuse endocrine system (DES) positive to gastrin, cholecystokinin-8, bombesin and secretin antisera in the intestine of the infected trout. The number of ECs immunoreactive to anti-glucagon serum did not show differences in the digestive tract of uninfected brown trout and in conspecifics parasitized with P. laevis. The density of cells containing glucagon-like material was low in the fish parasitized with C. truncatus. The results suggest that endoparasitic helminths induce alterations in the DES of infected S. trutta.