Strength properties of black spruce wood under different treatment

Summary The effect of various forms of treatment — chemical, thermal and pressure — on the tensile properties of wood was investigated. Spruce was impregnated in water, sodium sulfite and/or sodium bicarbonate, and heated at temperatures ranging from 20 to 190 °C. At the end of cooking (190 °C), decompression was applied both slowly and suddenly.A rise in temperature, an increase in heating time, from 4 to 10 min. at 190 °C, as well as fast pressure release influenced the tensile strength. The chemical treatment resulted in lignin sulfonation while carboxylation produced fiber swelling and, consequently, tensile strength decreased.The authors wish to thank the FCAR (Québec), NSERC (Canada) and Stake Tech. Co. for their financial support     

Technological quality of field grown transgenic lines of commercial wheat cultivars expressing the 1Ax1 HMW glutenin subunit gene

Ten transgenic lines were studied which expressed a transgene encoding HMW subunit 1Ax1 in three elite spring wheat cultivars: Imp, Canon and Cadenza. These lines contained one to five copies of the transgene and the 1Ax1 subunit was expressed as 1–20% of the total glutenin protein. These lines were grown in field trials in a continental, arid climate (Martonvásár, Hungary) over two years (2004, 2005). The expression of the transgenes and their effects on the grain properties were stably inherited over the two years. Significant differences in yield were observed between three of the transgenic lines and the original genotypes, but no differences were found in their adaptiveness. Clear differences were found in the technological and rheological properties of four lines, with all the parameters characterising dough strength and extensibility (GI, W, G, Re, Ext, A) changing significantly. These differences were associated with increases in the ratio of HMW/LMW subunits and decreases in the ratios of 1Dx/1Dy and 1Bx/1By subunits. Two transgenic lines of cv Imp had high over-expression of the 1Ax1 subunit which in one line resulted in an overstrong type of dough, similar to that described previously for lines over-expressing HMW subunit 1Dx5. Transformation of cvs. Canon and Cadenza resulted in two lines with increased dough stability due to the significantly improved gluten quality. It is concluded that significant changes in the structure of the glutenin polymers caused by the altered ratio of x-type to y-type HMW subunits led to the changes in flour functional properties.     

Phytochemical and dietary fiber components in barley varieties in the HEALTHGRAIN Diversity Screen

Ten different barley varieties grown in one location were studied for their content of tocols, folate, plant sterols, alkylresorcinols, and phenolic acids, as well as dietary fiber components (arabinoxylan and beta-glucan). The samples included hulled and hull-less barley types and types with normal, high-amylose, and waxy starch. The aim was to study the composition of raw materials, and therefore the hulls were not removed from the hulled barleys. A large variation was observed in the contents of all phytochemicals and dietary fibers. Two varieties from the INRA Clermont Ferrand barley program in France (CFL93-149 and CFL98-398) had high content of tocopherols and alkylresorcinols, whereas the variety Dicktoo was highest in dietary fiber content and phenolics. Positive correlations were found between 1000 kernel weight, alkylresorcinols, and tocols, as well as between dietary fiber content and phenolic compounds. The results demonstrate that the levels of phytochemicals in barley can likely be affected by breeding and that the contents of single phytochemicals may easily be adjusted by a right selection of a genotype.     

Puroindoline genes and proteins in tetraploid and hexaploid species of Triticum

Six tetraploid (5 Triticum turgidum and 1 Triticum timopheevii) and four hexaploid (three Triticum aestivum and one Triticum kiharae) taxa of Triticum were studied in order to identify novel variation in Pin genes and proteins which can be exploited in the improvement of cultivated wheat. Western blotting with a highly specific antibody showed that puroindoline proteins were present in all of the hexaploid lines but were absent from the tetraploids. The immunoreactive bands differed slightly in their relative mobilities and their relative amounts, which could have resulted from variation in the allelic forms of Pin a and Pin b. This was supported by HPLC analyses which showed differences in the retention times and peaks heights of the putative puroindoline components in T. kiharae and T. timopheevii. Sequence analyses of cDNAs also showed variation in the sequences of expressed puroindoline genes. In particular, a sequence encoding a new form of Pin b was present in T. aestivum ssp. macha.     

Genetics of dietary fibre in bread wheat

Arabinoxylans (AX) are major components of cell walls in wheat endosperm. The water-extractable part, WEAX, is considered as dietary fibres with health promoting effects. AX exhibit large natural variations in their amount but few studies have been carried out on the genetics of WEAX content and structure in bread wheat. We first carried out a “forward” quantitative genetic approach, using two recombinant populations derived from crosses between WEAX-high and WEAX-low parents and the viscosity of flour extract (WEAX-viscosity) as a predictor of WEAX content. This allowed us to identify two QTL regions, one of them, found on chromosome 6B in both populations, having a major effect with as much as 59% of the phenotypic variation explained by a single QTL. Then, we focused on key enzymes involved in the biosynthetic pathway of arabinoxylans. Out of 34 homoeologous candidate genes studied by sequencing a set of 46 lines, representing a worldwide diversity179 show no polymorphism. In the 16 polymorphic candidate genes, 80 SNP (in 15 genes) and 16 indels (in 4 genes) were detected. Then 27 SNP (in 13 genes) were genotyped in a larger collection of 156 lines (Healthgrain diversity screen). Eight associations were significant at an indicative 5% threshold, but only one, between COMT (Caffeic acid O methyltransferase) on chromosome 7A and A/X in WEAX was significant at a 1% level. The usefulness of these approaches and preliminary results for breeding is discussed.     

Bilateral avulsion fracture (apophyseolysis) of the calcaneal tuber in a heifer

This case report describes the clinical, radiographic, ultrasonographic and histopathological findings of a six-month-old heifer, suffering from bilateral fracture of the calcaneal tuber caused by osteochondrosis. The young cattle was admitted to the clinic for the evaluation of a left hindlimb lameness, having persisted for several weeks. Orthopaedic examination revealed a highly stilted gait with a lameness of the left hind limb, so severe that the heifer was only able to put some weight on the tip of the toe. The calcaneal region on both hindlimbs showed a diffuse swelling, palpation being very painful. The radiological examination revealed a fracture of the calcaneal tuber (apophyseolysis) of both hindlimbs.     

High incidence of lymphoid neoplasia in a colony of Egyptian spiny-tailed lizards (Uromastyx aegyptius).

Hematopoietic malignancies are the most commonly reported neoplasms in lizards, occurring sporadically as in other reptiles. An unusually high incidence of lymphoid neoplasia occurred in a collection of Egyptian spiny-tailed lizards (Uromastyx aegyptius) from 1993-2001. Eight of 15 lizards necropsied at the Louisville Zoological Garden (53%) had multicentric lymphoma. Immunohistochemistry was not useful in characterizing the lineage of normal or neoplastic lymphocytes. By light and electron microscopy (EM), the neoplasms had plasmacytoid morphologic features suggesting B-cell origin, although some tumors also had a primitive lymphoblast component. A concurrent leukemic blood profile was identified in seven of the cases (88%). All were adult animals and no sex predilection was observed. No exposure to exogenous carcinogens was observed. Some of the lizards were unrelated, so hereditary factors were unlikely. Although examination by EM and viral isolation performed on archived tissues and plasma failed to detect viruses, an infectious etiology still warrants consideration.     

Mathematical modeling for evaluating gain of logging companies in the timber market

We propose a game-theoretic model for a first-price sealed-bid auction (FPSB auction) of standing timber. A FPSB auction means that bidders simultaneously submit sealed bids so that no bidder knows the bid of any other participant. The highest bidder pays the submitted price. The mathematical model has been elaborated considering only two bidders. Each bidder is supposed to know only the probability distribution of the bid of the other bidder. Using appropriate distributions, the adversity and propensity of a bidder to risk can be described. From the view point of a bidder, the conservative solution is calculated for both types of the other bidder. If a standing timber belongs to a public owner, the market has to follow a public evidence procedure, including public auctions. The function obtained is illustrated with a numerical example of a typical standing timber auction from a forest located in central Italy. Considering average costs and prices of the local chestnut timber market, winning bids and expected gains are estimated. Their amounts are comparable with the currently average stumpage price registered in this market.