bluuebunny/crossref_metadata_2025 huggingface dataset:
Terpenoid metabolite profiling in Sitka spruce identifies association of dehydroabietic acid, (+)-3-carene, and terpinolene with resistance against white pine weevil
Authors: Robert Jeanne A. , Madilao Lufiani L. , White Rick , Yanchuk Alvin , King John , Bohlmann Jörg
Published: October 2010

The white pine weevil ( Pissodes strobi Peck) is an important insect pest in the Pacific Northwest that attacks the apical stem leaders of spruce ( Picea spp.) causing damage to tree form, growth, and stand development. Because of attacks by weevils, Sitka spruce ( P. sitchensis Bong.) is not commonly replanted as a commercial species in coastal British Columbia, despite its economic and ecological importance. In the last decade, the focus of research on Sitka spruce resistance against weevils has moved from silvicultural approaches to breeding for resistance. The British Columbia Ministry of Forests and Range, in collaboration with the Canadian Forest Service, has developed a successful program to screen populations and select tree genotypes for resistance to weevil attack. Part of this effort has been the establishment of clonebanks that contain genotypes from throughout the range of Sitka spruce. For metabolite profiling, using gas chromatography coupled with flame ionization detection or mass spectrometry, we analysed 111 different genotypes to determine the relationship of mono- and di-terpenoid oleoresin compounds with the resistance rating. Dehydroabietic acid, a diterpene, was identified as a strong indicator of resistance. Two monoterpenes, (+)-3-carene and terpinolene, were also associated with resistance in genotypes originating from one of the areas (Haney) in which resistance has been noted.
Conspecificity of DAOM 197198, the model arbuscular mycorrhizal fungus, with Glomus irregulare: molecular evidence with three protein-encoding genes
Authors: Sokolski Serge , Dalpé Yolande , Séguin Sylvie , Khasa Damase , Lévesque C. André , Piché Yves
Published: October 2010

Ribosomal nuclear genes are routinely utilized in the molecular identification of fungi. The variation in the multiple copies of these genes within each Glomeromycota strain and species reduces their usefulness for molecular characterization of arbuscular mycorrhizal fungi. To explore the potential of molecular tools for the identification of Glomus species, a multi-gene analysis approach was undertaken. Three protein-encoding genes were tested, namely elogation factor 1-α (765 bp), V-H+-ATPase VHA5 (1468 bp), and F0F1-ATPase β-subunit (621 bp). The latter is newly reported for the Glomeromycetes. Eleven species, including the type-specimen of Glomus irregulare Blaszk., Wubet, Renker & Buscot, a reference strain of G. intraradices N.C. Schenck & G.S. Sm. (DAOM 225240), and five strains of Glomus sp. formerly identified as G. intraradices, were analysed. These genes did not show polymorphisms within strains, and results indicated a close relationship between molecular identification and morphological characterization. Species with closely related spore morphological features, G. aggregatum N.C. Schenck & G.S. Sm., G. diaphanum Morton & Walker, G. irregulare , and Glomus sp. DAOM 197198, showed more than 99% nucleotide similarity, while the morphologically distinct species, G. cerebriforme McGee, G. clarum T.H. Nicolson & N.C. Schenck, G. claroideum N.C. Schenck & G.S. Sm., G. custos C. Cano & Dalpé, G. mosseae (T.H. Nicolson & Gerd.) Gerd. & Trappe, and G. proliferum Dalpé & Declerck, showed less than 97% similarity for at least one gene. A 100% molecular similarity for all three genes was found between G. irregulare and Glomus sp. DAOM 197198, confirming the new identity of the model arbuscular mycorrhizal fungus. Similarity thresholds for identification by DNA sequencing are discussed.
Effect of three salts on germination and seedling survival of dimorphic seeds of Chenopodium album
Authors: Yao Shixiang , Chen Shasha , Zhao Juan , Xu Dongsheng , Lan Haiyan , Zhang Fuchun
Published: October 2010

Chenopodium album  L., a salt-tolerant species that is widely distributed in the semi-arid areas of Xinjiang, China, produces numerous dimorphic seeds (black and brown). To investigate the effects of three salts (NaCl, KCl, and CaCl2, which constitute the main salt cations in the soil in semi-arid areas) on seed germination and seedling survival of C. album, seeds were germinated in different salinity treatments: 0, 100, 200, and 250 mmol·L–1 of NaCl or KCl; or, 300 and 400 mmol·L–1 NaCl or KCl, each amended with CaCl2 (0, 2.5, 5.0, 7.5, and 10.0 mmol·L–1). Results showed that the brown seeds were more salt tolerant, and a higher percentage germinated than black seeds in the different salinity treatments. The percentage of germinating of black seeds could be significantly improved, when under saline conditions, by the synergetic action of ethephon (C2H6ClO3P) and KNO3. The addition of low concentrations of CaCl2 improved seed germination for seeds exposed to 300 mmol·L–1 NaCl or KCl, and the alleviating effects were stronger for the brown than for the black seeds. Seedling survival could also be enhanced by the addtion of CaCl2. These results suggest that the dimorphic seeds of C. album exhibit different germination patterns under different salinity conditions, and that the diversity in salt tolerance of dimorphic seeds enables C. album to adapt to semi-arid areas successfully. The physiological mechanism by which CaCl2 enhances the germination of dimorphic seeds requires further study.
Population genetic structure and phylogeographic patterns in the Chinese endemic speciesSagittaria lichuanensis, inferred from cpDNAatpB–rbcL intergenic spacers
Authors: Liu Fan , Zhao Shu-Ying , Li Wei , Chen Jin-Ming , Wang Qing-Feng
Published: October 2010

Both historical (e.g., glaciations) and spatial (geological features) factors are considered to have had significant influences on the distribution and genetic structure of many plants. To understand the effects of such factors on the current genetic and geographical distributions of plant species in the Nanling and central regions in China, we examined genetic variation and phylogeographical patterns of Sagittaria lichuanensis J.K. Chen (Alismataceae), an endangered and endemic species in China, using chloroplast DNA atpB–rbcL intergenic spacer sequence variation. In this study, a total of 9 haplotypes from 47 individuals in 6 populations of S. lichuanensis were detected. The NST(0.193) was significantly higher than GST(0.082) (P < 0.05), indicating a significant phylogeographical structure. In the minimum spanning network (MSN) of the haplotypes, the distribution of haplotypes showed an east–west split. The results of the Mantel test analysis showed that there was no correlation between the genetic distance and geographical distance (r = 0.539, P > 0.05). The formation of barriers to dispersal might have played an important role in shaping the population genetic structure of S. lichuanensis. Within each region (east and west regions), high levels of gene flow between populations and low levels of population differentiation were found. Several conditions, such as co-ancestry due to recent common ancestry or short period of isolation, might have occurred among the populations studied. In the MSN, all tip haplotypes except for two (A and G) occurred in two or more populations, and the haplotype D in the interior node was widespread. The haplotype D is likely to be an ancestral haplotype and represents the relic, widely distributed haplotype before the populations were fragmented and isolated by mountain uplift.
A taxonomic revision ofAllium(Alliaceae) in the Canadian prairie provinces
Authors: Choi Hyeok Jae , Cota-Sánchez J. Hugo
Published: October 2010

The taxonomy, rarity, and conservation status of Allium  L. is revised for the Canadian prairie provinces, based on analyses of herbarium specimens and fieldwork. Five species are recognized: Allium schoenoprasum  L., A. geyeri S. Watson var. tenerum M.E. Jones, A. textile A. Nelson & J.F. Macbride, A. cernuum Roth, and A. stellatum Ker Gawler. Distribution maps and a key to species are provided, as well as complete descriptions of the species examined, including new illustrations, information on nomenclatural types, synonymies, and chromosomal and ecological data. A lectotype is designated for A. geyeri var. tenerum. In this study, A. geyeri var. geyeri reported from Alberta and Saskatchewan and ranked in these provinces as having rarity levels S2 and S1, respectively, by the Nature Conservancy, is excluded from the Canadian flora and the rare list of these provinces because it was misidentified from a herbarium specimen of A. textile. Allium tricoccum Solander in W. Aiton is regarded as a non-native species to Manitoba. The rarity and conservation status of Allium in the Canadian prairie provinces is as follows: (i) A. schoenoprasum, listed as S2 in Saskatchewan, is rare in Manitoba, although its rarity status has not been formally assessed in the province; (ii) A. geyeri var. tenerum is the rarest Allium taxon, with distribution restricted to the Waterton Lakes National Park areas of Alberta, and is currently listed as S2; and (iii) A. cernuum was re-evaluated and a rarity level of S1S2 was recommended for the species in Saskatchewan, particularly in its southwestern distributional habitat.
Mineral nutrient concentration influences sunflower infection by broomrape (Orobanche cumana)
Authors: Labrousse P. , Delmail D. , Arnaud M. C. , Thalouarn P.
Published: October 2010

Orobanche cumana Wallr., a root parasitic angiosperm, causes severe yield losses in Helianthus annuus  L. (sunflower) in Europe. Until now, the only effective method of controlling this parasite has been the use of resistant sunflower genotypes. Broomrape resistance is, however, poorly understood even though previous studies have revealed several defence mechanisms. The study of a susceptible (2603) and a resistant (LR1) sunflower genotype in hydroponic co-culture showed that the degree of infection by broomrape is influenced by the concentration of nutrients in the growth medium. For the susceptible genotype, an increase in broomrape necrosis was observed when the nutrient concentration was increased. In the resistant genotype LR1, the rate of infection was reduced by increasing the concentration of mineral nutrients, measured as a decrease in broomrape attachments and a lack of underground stem development. When sunflowers were cultivated in full-strength medium, these findings correlated with a lower 14C incorporation in broomrape and a change in carbon allocation to host plant organs with a reinforced “shoot apex sink strength”. Results demonstrated that in controlled conditions, the nutrient concentration directly affects sunflower resistance potential towards broomrape.
The illustrated life cycle ofMicrobotryumon the host plantSilene latifolia
Authors: Schäfer Angela Maria , Kemler Martin , Bauer Robert , Begerow Dominik
Published: October 2010

The plant-parasitic genus Microbotryum (Pucciniomycotina) has been used as a model for various biological studies, but fundamental aspects of its life history have not been documented in detail. The smut fungus is characterized by a dimorphic life cycle with a haploid saprophytic yeast-like stage and a dikaryotic plant-parasitic stage, which bears the teliospores as dispersal agents. In this study, seedlings and flowers of Silene latifolia Poir. (Caryophyllaceae) were inoculated with teliospores or sporidial cells of Microbotryum lychnidis-dioicae (DC. ex Liro) G. Deml & Oberw. and the germination of teliospores, the infection process, and the proliferation in the host tissue were documented in vivo using light and electron microscopy. Although germination of the teliospore is crucial for the establishment of Microbotryum, basidium development is variable under natural conditions. In flowers, where the amount of nutrients is thought to be high, the fungus propagates as sporidia, and mating of compatible cells takes place only when flowers are withering and nutrients are decreasing. On cotyledons (i.e., nutrient-depleted conditions), conjugation occurs shortly after teliospore germination, often via intrapromycelial mating. After formation of an infectious hypha with an appressorium, the invasion of the host occurs by direct penetration of the epidermis. While the growth in the plant is typically intercellular, long distance proliferation seems mediated through xylem tracheary elements. At the beginning of the vegetation period, fungal cells were found between meristematic shoot host cells, indicating a dormant phase inside the plant. By using different microscopy techniques, many life stages of Microbotryum are illustrated for the first time, thereby allowing new interpretations of laboratory data.
Maternal effects and drought tolerance determine seedling establishment success in a common roadside plant,Dipsacus fullonumsubspsylvestris
Authors: Beaton Laura L. , Dudley Susan A.
Published: October 2010

Previous studies have demonstrated that plants collected as seeds from roadside populations of Dipsacus fullonum L. subsp sylvestris (Huds.) Claphamare more tolerant of high salinity, low osmotic potentials, and hypoxia during juvenile growth stages than those from oldfield populations. However, it is unclear how tolerance to these abiotic stressors translates into performance in the roadside environment. Here, we conducted a reciprocal transplant experiment between oldfield and roadside environments. Seeds from three roadside and three oldfield populations were planted into oldfield and roadside sites in late fall. Throughout the spring and summer, the survivorship and size of the seedlings were monitored to examine differences in performance in the two habitats. We also assessed the relation between performance in the field and previous in vitro measures of salt and drought tolerance of each population. A drought caused high mortality levels in the oldfield and roadside. Individuals from roadside populations did not exhibit increased growth or survivorship in the roadside environment. In the early months of seedling growth, neither salt nor drought tolerance were significantly correlated with performance in the roadside during seedling establishment. Rather, during these early months, the average size of individuals in each population in the field was positively correlated with the population’s average seed mass, indicating that maternal provisioning had a greater impact than tolerance to particular environmental stresses during the juvenile stages of development. However, later in the summer, after the drought began, the average size of individuals from each population in the field was positively correlated with that population’s average drought tolerance.
Energy dynamics and growth of Chinook salmon (Oncorhynchus tshawytscha) from the Central Valley of California during the estuarine phase and first ocean year
Authors: MacFarlane R. Bruce
Published: October 2010

The greatest rates of energy accumulation and growth in subyearling Chinook salmon ( Oncorhynchus tshawytscha ) occurred during the first month following ocean entry, supporting the importance of this critical period. Data from an 11-year study in the coastal ocean off California and the San Francisco Estuary revealed that juvenile salmon gained 3.2 kJ·day–1and 0.8 g·day–1, representing 4.3%·day–1and 5.2% day–1, respectively, relative to estuary exit values. Little gain in energy (0.28 kJ·day–1) or size (0.07 g·day–1) occurred in the estuary, indicating that the nursery function typically ascribed to estuaries can be deferred to initial ocean residence. Calculated northern anchovies ( Engraulis mordax ) equivalents to meet energy gains were one anchovy per day in the estuary (8% body weight·day–1) and about three per day immediately following ocean entry (15% body weight·day–1). Energy content in the estuary was positively related to higher salinity and lower freshwater outflow, whereas in the ocean, cooler temperatures, lower sea level, and greater upwelling resulted in greater gains. These results suggest that greater freshwater flows, warmer sea temperatures, and reduced or delayed upwelling, all of which are indicated by some (but not all) climate models, will likely decrease growth of juvenile Chinook salmon, leading to reduced survival.
Bioenergetic responses of a benthic forage fish (Fundulus heteroclitus) to habitat degradation and altered prey community in polluted salt marshes
Authors: Goto Daisuke , Wallace William G.
Published: October 2010

In this study, we examined bioenergetic responses of age-2+ and age-3+ mummichogs ( Fundulus heteroclitus ) to degraded habitat condition and impoverished benthic prey community in polluted salt marshes by incorporating in situ food consumption rates with the mercury mass balance model technique. In general, bioenergetic responses of mummichogs appeared to be more related to benthic prey community than habitat condition. Fish from prey-impoverished marsh (PIM) sites generally had significantly elevated total metabolic costs compared with those from non-prey-impoverished marsh (NPIM) sites. However, the PIM populations also had ~two- to three-fold higher consumption rates than the NPIM populations, suggesting that the PIM populations may be capable of adjusting food consumption to offset elevated metabolic costs. Furthermore, only age-2+ females of the PIM populations had significantly reduced growth rates, whereas there was little among-site differences for age-2+ males and age-3+ fish, indicating that an increased consumption by the PIM populations may also have been a compensatory mechanism to maintain growth. Most of the PIM populations, however, had substantially (up to 80%) lower growth conversion efficiency relative to the NPIM populations. These findings suggest that pollution-tolerant fishes such as mummichogs may have energetic costs of living in chronically degraded habitats.
Large effective population size and temporal genetic stability in Atlantic cod (Gadus morhua) in the southern Gulf of St. Lawrence
Authors: Therkildsen Nina Overgaard , Nielsen Einar Eg , Swain Douglas P. , Pedersen Jes Søe
Published: October 2010

Worldwide, many commercial fish stocks have experienced dramatic declines due to overfishing. Such fisheries-induced population reductions could potentially erode the genetic diversity of marine fish populations. Based on analyses of DNA extracted from archived and contemporary samples, this paper compares the genetic variability at nine microsatellite loci in a Canadian population of Atlantic cod ( Gadus morhua ) over 80 years, spanning from before the fishery intensified to now when the population is at historically low abundance. Extensively validated genetic data from the temporally spaced samples were used to estimate the effective population size. Over the period, we observed no loss of either heterozygosity or allelic diversity. Several of the estimation methods applied could not distinguish the effective population size from infinity, and the lower 95% confidence limit on estimates was generally >500, suggesting that the effective population size is probably considerably larger than this. Hence, it appears that the southern Gulf of St. Lawrence cod stock has maintained genetic variability to sustain future evolution despite a dramatic population decline.
Direct and indirect effects of fish on pelagic nitrogen and phosphorus availability in oligotrophic Arctic Alaskan lakes
Authors: Johnson Cody R. , Luecke Chris , Whalen Stephen C. , Evans Mary Anne
Published: October 2010

The importance of fish nutrient recycling for lake primary production increases with lake productivity. However, fish in low-productivity lakes may have substantial indirect effects on nutrient recycling from lower trophic levels. We measured nutrient excretion rates from fish and zooplankton in oligotrophic Arctic lakes and investigated direct and indirect fish effects on consumer nutrient recycling. Fish nutrient excretion rates were small relative to phytoplankton nutrient demand. Zooplankton excretion, however, supplied 19%–130% and 37%–200% of phytoplankton nitrogen and phosphorus demand, respectively. Fish had a significant effect on zooplankton biomass; in lakes with fish, this was approximately 80% lower than in lakes without fish. The difference in zooplankton biomass was due primarily to a decrease in zooplankton density; no significant difference in average zooplankton size was observed between fish and fishless lakes. Fish also impacted zooplankton community composition; communities in lakes with fish were dominated by copepods compared with cladoceran dominance in lakes without fish. Because of lower zooplankton biomass, lakes with fish showed lower rates of zooplankton nitrogen and phosphorus excretion relative to lakes without fish. Thus, our results support the hypothesis that fish have major indirect effects on lake nutrient cycles, even when direct excretion from fish is minimal.
Long-term exposure of Atlantic cod (Gadus morhua) to components of produced water: condition, gonad maturation, and gene expression
Authors: Holth Tor Fredrik , Thorsen Anders , Olsvik Pål A. , Hylland Ketil
Published: October 2010

Effects related to offshore contamination have been observed in gadoid species in the North Sea, but uncertainties regarding exposure conditions have led to the need for environmentally relevant exposure studies. In the current study, Atlantic cod ( Gadus morhua ) were sampled at regular intervals during an 11-month continuous or pulsed water-borne exposure to a mixture of produced water components. There was variation in time to female maturation between and within treatment groups; although differences were not significant, there was a tendency towards delayed maturation in intermittently exposed females not seen in continuously exposed females. Physiological parameters such as condition factor, liver somatic index, gonadosomatic index, or hematocrit did not appear to be affected by the treatments. A range of toxicologically relevant genes were differentially expressed in the exposed fish, including AhR-responsive genes (CYP1A, UDP-GT) and genes relevant to immune function (complement C3, MHC 1, CYP27B), apoptosis (PERP), and oxidative stress (hepcidin, serotransferrin, glutathione peroxidase). Although powerful in their depiction of the complexity of cellular responses to environmental stressors, the use of molecular tools should be accompanied by biochemical and physiological endpoints, and results should be holistically interpreted in terms of individual health and function.
Coptotermes gestroi (Isoptera: Rhinotermitidae) in Brazil: possible origins inferred by mitochondrial cytochrome oxidase II gene sequences
Authors: Martins C. , Fontes L. R. , Bueno O. C. , Martins V. G.
Published: October 2010

The Asian subterranean termite, Coptotermes gestroi , originally from northeast India through Burma, Thailand, Malaysia, and the Indonesian archipelago, is a major termite pest introduced in several countries around the world, including Brazil. We sequenced the mitochondrial COII gene from individuals representing 23 populations. Phylogenetic analysis of COII gene sequences from this and other studies resulted in two main groups: (1) populations of Cleveland (USA) and four populations of Malaysia and (2) populations of Brazil, four populations of Malaysia, and one population from each of Thailand, Puerto Rico, and Key West (USA). Three new localities are reported here, considerably enlarging the distribution of C. gestroi in Brazil: Campo Grande (state of Mato Grosso do Sul), Itajaí (state of Santa Catarina), and Porto Alegre (state of Rio Grande do Sul).
Construction of a Coix BAC library and isolation of the 22 kDa α-coixin gene cluster
Authors: Meng Xiangzong , Huang Binbin , Zhou Liangliang , He Yunxia , Chen Qi , Yuan Yiwei , Xu Zhengkai , Song Rentao
Published: October 2010

Coix lacryma-jobi L. (Coix) is a close relative of maize and is considered a valuable genetic resource for crop improvement. Here we report the construction of the first Coix bacterial artificial chromosome (BAC) library using accession PI 324059. This BAC library contains about 230 400 clones with an average insert size of 113 kb, has low organellar DNA contamination, and provides 16.3-fold coverage of the genome. The library was stored in 12 × 96 pools that could be screened with a PCR protocol. Library screening was performed for the 22 kDa α-coixin gene family. A total of 57 positive pools were identified, and single clones were isolated from 19 of these pools. Based on DNA fingerprinting and Southern blot analysis, these 19 BAC clones form a single contig of about 340 kb in length, indicating that the 22 kDa α-coixin genes occur in a cluster. These results demonstrated the suitability of this BAC library for gene isolation and comparative genomics studies of the Coix genome.
Mapping of quantitative trait loci for fire blight resistance in the apple cultivars ‘Florina’ and ‘Nova Easygro’
Authors: Le Roux P.-M. F. , Khan M. A. , Broggini G. A.L. , Duffy B. , Gessler C. , Patocchi A.
Published: October 2010

Fire blight is a devastating bacterial disease of rosaceous plants. Its damage to apple production is a major concern, since no existing control option has proven to be completely effective. Some commercial apple varieties, such as ‘Florina’ and ‘Nova Easygro’, exhibit a consistent level of resistance to fire blight. In this study, we used an F1progeny of ‘Florina’ × ‘Nova Easygro’ to build parental genetic maps and identify quantitative trait loci (QTLs) related to fire blight resistance. Linkage maps were constructed using a set of microsatellites and enriched with amplified fragment length polymorphism (AFLP) markers. In parallel, progeny plants were artificially inoculated with Erwinia amylovora strain CFBP 1430 in a quarantine glasshouse. Shoot length measured 7 days after inoculation (DAI) and lesion length measured 7 and 14 DAI were used to calculate the lesion length as a percentage of the shoot length (PLL1 and PLL2, respectively). Percent lesion length data were log10-transformed (log10(PLL)) and used to perform the Kruskal–Wallis test, interval mapping (IM), and multiple QTL mapping (MQM). Two significant fire blight resistance QTLs were detected in ‘Florina’. One QTL was mapped on linkage group 10 by IM and MQM; it explained 17.9% and 15.3% of the phenotypic variation by MQM with log10(PLL1) and log10(PLL2) data, respectively. A second QTL was identified on linkage group 5 by MQM with log10(PLL2) data; it explained 10.1% of the phenotypic variation. Genotyping the plants of ‘Florina’ pedigree with the microsatellites flanking the QTLs showed that the QTLs on linkage groups 5 and 10 were inherited from ‘Jonathan’ and ‘Starking’ (a ‘Red Delicious’ sport mutation), respectively. Other putative QTLs (defined as QTLs with LOD scores above the chromosomal threshold and below the genome-wide threshold) were detected by IM on linkage groups 5 and 9 of ‘Nova Easygro’.
The ionotropic γ-aminobutyric acid receptor gene family of the silkworm, Bombyx mori
Authors: Yu Lin-Lin , Cui Ying-Jun , Lang Guo-Jun , Zhang Ming-Yan , Zhang Chuan-Xi
Published: October 2010

γ-Aminobutyric acid (GABA) is a very important inhibitory neurotransmitter in both vertebrate and invertebrate nervous systems. GABA receptors (GABARs) are known to be the molecular targets of a class of insecticides. Members of the GABAR gene family of the silkworm, Bombyx mori , a model insect of Lepidoptera, have been identified and characterized in this study. All putative silkworm GABAR cDNAs were cloned using the reverse transcriptase polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). Bombyx mori appears to have the largest insect GABAR gene family known to date, including three RDL, one LCCH3, and one GRD subunit. The silkworm RDL1 gene has RNA-editing sites, and the RDL1 and RDL3 genes possess alternative splicing. These mRNA modifications enhance the diversity of the silkworm’s GABAR gene family. In addition, truncated transcripts were found for the RDL1 and LCCH3 genes. In particular, the three RDL subunits may have arisen from two duplication events.
Evolution of seismic design provisions in theNational building code of Canada
Authors: Mitchell Denis , Paultre Patrick , Tinawi René , Saatcioglu Murat , Tremblay Robert , Elwood Kenneth , Adams John , DeVall Ronald
Published: October 2010

The purpose of this paper is to provide a summary of the evolution of seismic design in Canada. This paper presents the significant changes to the approach taken in determining seismic hazards and seismic hazard maps, and describes the evolution of the seismic design provisions of the National building code of Canada. The introduction of important parameters in determining the seismic base shear such as the period of vibration of the structure, the influence of type of soil, and the concepts of ductility and energy dissipation capacity of elements and structures are presented. The levels of seismic design base shears, determined from different versions of the National Building Code of Canada, are compared for reinforced concrete frame and wall structures to illustrate the changes.
Simulation-based aggregate planning of batch plant operations
Authors: Tian Xueying , Mohamed Yasser , AbouRizk Simaan
Published: October 2010

Production and supply of construction materials plays a significant role in the delivery of constructed facilities, especially for concrete and asphalt batch plants. The construction material (e.g., concrete) supply chain presents unique challenges, but is a key factor in successfully delivering facilities. This paper presents the development and application of a simulation-based aggregate planning approach that facilitates modeling and coordination of a batch plant’s supply chain. The tool is applied to a real case of asphalt production operations, where fluctuating demand affects the service level of the production plant and makes the planning of production and inventory processes a challenging task. The model quantifies the effects of different parameters of the asphalt production plant on its level of service and assists in finding the best configurations for the plant’s production, inventory, and distribution processes.
Strain monitoring in a reinforced concrete slab sustaining service loads by distributed Brillouin fibre optic sensors
Authors: Martín-Pérez Beatriz , Deif Amre , Cousin Bruno , Zhang Chunshu , Bao Xiaoyi , Li Wenhai
Published: October 2010

Reinforced concrete (RC) structures deteriorate and as a result crack due to extreme loading and (or) environmental conditions. Damage accumulation as such adversely affects the structure’s durability properties, impairing its service life. The intensity of cracking in an RC structure is usually regarded as the key criterion toward damage assessment and repair intervention. This paper presents the results of an experimental program in which the concrete strains of a small-scale RC slab sustaining in-service loads were monitored by traditional electrical strain gauges and distributed Brillouin fibre optic sensors in an attempt to detect damage due to crack formation. A comparison of these measurements with classical bending theory is also presented. The results show that distributed Brillouin fibre optic sensors can capture both tensile and compressive strains in concrete; however, the accuracy of their measurements is dependent on the proper installation of the sensors and the fibre length over which the strains are to be measured.
Optimisation de la granulométrie des matériaux granulaires de fondation des chaussées
Authors: Bilodeau Jean-Pascal , Doré Guy , Pierre Pascale
Published: October 2010

Les matériaux granulaires de fondations de chaussées jouent un rôle structural important mais sont aussi affectés par l’environnement. La granulométrie et la source de granulats vont changer la façon dont ces matériaux réagissent à ces sollicitations. Cette étude cherche donc à évaluer la performance globale des matériaux granulaires face aux contraintes mécanique et environnementale. Le module réversible, la déformation permanente, la gélivité et la conductivité hydraulique ont été mesurés pour six granulométries et trois sources. Les résultats montrent l’effet significatif de la granulométrie et de la source dans le contexte d’un fuseau granulaire et permettent de suggérer des fenêtres de performance granulométrique adaptées à des contextes de performance typiques. Ces effets de la granulométrie et de la source peuvent atteindre des facteurs 14 et 7 d’un point de sensibilité aux contraintes environnementales et des facteurs 3 et 2,5 d’un point de vue de la sensibilité aux contraintes mécaniques.
Estimating continuous highway vertical alignment using the least-squares method
Authors: Easa Said M. , Wang Fujian
Published: October 2010

Highway profile information may not be available or may not be up to date, especially for old highways. In these cases, profile data are collected using global positioning systems (GPS) or by extracting them from digital images. This paper presents an optimization model for estimating the parameters of continuous vertical alignments, involving multiple parabolic vertical curves that best fit existing highway profile data using the least-squares method. The optimization involves two levels: single-curve optimization and multiple-curve optimization. The former is used to obtain the approximate length of each vertical curve based on the approximate tangent parameters determined from the outline controlling points. The latter is used to obtain the global optimal parameters for tangents and vertical curves. The model is validated and applied using actual data of a vertical alignment. The proposed model presents a useful extension to existing methods for estimating simple vertical alignments and therefore should be of interest to highway engineering professionals.
Prevention of cytokine withdrawal-induced apoptosis by Mcl-1 requires interaction between Mcl-1 and Bim
Authors: Jamil Sarwat , Wang Shih Wei , Bondy Lise , Mojtabavi Shadi , Duronio Vincent
Published: October 2010

Growth factor withdrawal from hemopoietic cells results in activation of the mitochondrial pathway of apoptosis. Members of the Bcl-2 family regulate this pathway, with anti-apoptotic members counteracting the effects of pro-apoptotic members. We investigated the effect on Mcl-1 function of mutation at a conserved threonine 163 residue (T163) in its proline, glutamate, serine, and threonine rich (PEST) region. Under normal growth conditions, Mcl-1 half-life increased with alteration of T163 to glutamic acid, but decreased with mutation to alanine. However, both T163 mutants exhibited greater pro-survival effects compared with the wild type, which can be explained by an increased stability of the T163A mutant in cytokine-starved conditions. Both the mutant forms exhibited prolonged binding to pro-apoptotic Bim in cytokine-deprived cells. The extent to which Mcl-1 mutants were able to exert their anti-apoptotic effects correlated with their ability to associate with Bim. We further observed that primary bone marrow derived macrophages survived following cytokine withdrawal as long as Bim and Mcl-1 remained associated. In our study, we were unable to detect a role for GSK-3-mediated regulation of Mcl-1 expression. Based on these results we propose that upon cytokine withdrawal, survival of hemopoietic cells depends on association between Mcl-1 and Bim. Furthermore, alteration of T163 of Mcl-1 may change the protein such that its association with Bim is affected, resulting in prolonged association and increased survival.
Trends in matrix metalloproteinase research from 1986–2007: a bibliometric study
Authors: Robert Claude , Wilson Concepción S. , Gaudy Jean-François , Hornebeck William , Arreto Charles-Daniel
Published: October 2010

Using the SCI-expanded database, this study provides a quantitative description of the development of the research involving matrix metalloproteinase (MMP) over a period of 20 years. From 1986 to 2007 the scientific literature related to MMP increased sevenfold (397 papers in 1986–1987 and 2834 in 2006–2007). The number of countries participating in MMP-related research doubled during this period (33 in 1986–1987 to 67 in 2006–2007), and the USA continually remained the leader. Several industrialized nations (Japan, Germany, UK, Canada, and France) also continuously played important roles, with some emerging Asian countries joining the top 10 most productive countries in 2006–2007: China (ranked 5th), South Korea (6th), and Taiwan (10th). The MMP-related literature was distributed among a continuously growing number of journals (188 in 1986–1987, 527 in 1996–1997, and 913 in 2006–2007) and The Journal of Biological Chemistry remained the most prolific throughout the entire period. The development of the research involving MMPs during the past two decades was also characterized by a progressive transfer of interest from basic research to clinical medicine; cell biology and pharmacology were important routes of investigation generally pursued by researchers. Journals dedicated to oncology have progressively risen to the top 8 most prolific journals during the 20 year period analyzed.
Role of Met-542 as a guide for the conformational changes of Phe-601 that occur during the reaction of β-galactosidase (Escherichia coli)
Authors: Dugdale Megan L. , Dymianiw Dayna L. , Minhas Bhawanjot K. , D’Angelo Igor , Huber Reuben E.
Published: October 2010

The Met-542 residue of β-galactosidase is important for the enzyme’s activity because it acts as a guide for the movement of the benzyl side chain of Phe-601 between two stable positions. This movement occurs in concert with an important conformational change (open vs. closed) of an active site loop (residues 794–803). Phe-601 and Arg-599, which interact with each other via the π electrons of Phe-601 and the guanidium cation of Arg-599, move out of their normal positions and become disordered when Met-542 is replaced by an Ala residue because of the loss of the guide. Since the backbone carbonyl of Phe-601 is a ligand for Na+, the Na+also moves out of its normal position and becomes disordered; the Na+binds about 120 times more poorly. In turn, two other Na+ligands, Asn-604 and Asp-201, become disordered. A substrate analog (IPTG) restored Arg-599, Phe-601, and Na+to their normal open-loop positions, whereas a transition state analog (d-galactonolactone) restored them to their normal closed-loop positions. These compounds also restored order to Phe-601, Asn-604, Asp-201, and Na+. Binding energy was, however, necessary to restore structure and order. The Ksvalues of oNPG and pNPG and the competitive Kivalues of substrate analogs were 90–250 times higher than with native enzyme, whereas the competitive Kivalues of transition state analogs were ~3.5–10 times higher. Because of this, the E•S energy level is raised more than the E•transition state energy level and less activation energy is needed for galactosylation. The galactosylation rates (k2) of M542A–β-galactosidase therefore increase. However, the rate of degalactosylation (k3) decreased because the E•transition state complex is less stable.
Effets du couplage source–conduit vocal sur le modèle à deux masses
Authors: Teffahi H. , Kherouf S.
Published: October 2010

Nous présentons une simulation de la source vocale, connue comme modèle à deux masses. Ce modèle simule le fonctionnement des cordes vocales humaines. Une étude qualitative des effets du couplage source–conduit sur la forme et le spectre de l’onde de débit de la glotte est entreprise. Cette simulation va permettre de mieux cerner le processus acoustique de production de la parole.
MHD convection with Soret and Dufour effects in a three-dimensional flow past an infinite vertical porous plate
Authors: Ahmed N.
Published: October 2010

In this paper, the Soret and Dufour effects on a mixed convective mass transfer flow past an infinite vertical porous plate with transverse sinusoidal suction velocity in presence of a uniform transverse magnetic field have been studied analytically. The magnetic Reynolds number is assumed to be so small that the induced magnetic field can be neglected. The nondimensional equations governing the flow and heat and mass transfer are solved by regular perturbation technique, on the assumption that the solution consists of two parts: a mean part and a perturbed part. The expressions for the velocity, temperature and concentration fields, skin friction at the plate in the direction of the free stream, Nusselt number and Sherwood number at the plate, and the current density are obtained in nondimensional forms. The effects of the Hartmann number M, the Soret number Sr, the Dufour number Du, the Reynolds number Re, Schmidt number Sc, and the Prandtl number Pr on the flow and transport characteristics are discussed through graphs and tables. It is seen that viscous drag on the plate is reduced under the effect of thermal-diffusion (Soret) and diffusion-thermo (Dufour). On the other hand, the rate of heat transfer from the plate to the fluid falls because of the Dufour effect and rises under the Soret effect, whereas the mass flux from the plate to the fluid is delayed under the thermal-diffusion effect, but the reverse occurs under the effect of diffusion-thermo.
A review of 41 legal cases involving geotechnical practice in Canada
Authors: Abdulahad Suhail , Jergeas George , Ruwanpura Janaka
Published: October 2010

This paper explores factors that contribute to claims of changed soil conditions in infrastructure and building projects through a limited review of Canadian legal cases. Forty-one cases, relating to geotechnical problems covering a period of 25 years (1982–2006), were studied. The information obtained was categorized according to the causes for geotechnical claims. The most frequent causes of geotechnical disputes were found to be different soil conditions and recommendations than expected from those given in the geotechnical report, inaccuracies in the design plans and specifications, and the owner’s failure to disclose important information. The paper also discusses the special requirements for preparing geotechnical information for construction and suggests precautionary measures to reduce the number of disputes or to arrive at an equitable resolution. These measures require more proactive planning and may require additional funds before the bidding stage to perform a more detailed soil investigation, keep communication clear among all participants, and make a greater effort to provide accurate designs and specifications.
Determination of distribution coefficient of geomaterials and immobilizing agents
Authors: Arnepalli D. N. , Hanumantha Rao B. , Shanthakumar S. , Singh D. N.
Published: October 2010

The fate and transport of reactive contaminant(s) in geomaterials (i.e., soils and rocks) and efficacy of the immobilization–remediation methodology of the contaminated geomaterials is governed mainly by the sorption and desorption characteristics of these geomaterials and immobilizing agents. As such, establishment of these characteristics becomes mandatory. To achieve this, batch tests are usually conducted and a distribution coefficient is obtained from Freundlich, linear, and Langmuir isotherms. However, the relative efficiency of these isotherms needs to be ascertained for selection of the appropriate distribution coefficient for a contaminant geomaterial – immobilizing agent system. With this in mind, conventional batch tests were conducted on various geomaterials and immobilizing agents, to establish their sorption and desorption characteristics. However, it should be noted that batch tests do not represent the real-life contaminant geomaterial – immobilizing agent interaction, and are quite cumbersome and time-consuming. Under these circumstances, correlating sorption and desorption characteristics of these materials with the electrical conductivity of their solutions seems to be a potential alternative. Utility of this concept for modeling real-life contaminant geomaterial – immobilizing agent interaction has also been demonstrated very well in this study.
Shear strength and dilative characteristics of an unsaturated compacted completely decomposed granite soil
Authors: Hossain Md. Akhtar , Yin Jian-Hua
Published: October 2010

Shear strength and dilative characteristics of a re-compacted completely decomposed granite (CDG) soil are studied by performing a series of single-stage consolidated drained direct shear tests under different matric suctions and net normal stresses. The axis-translation technique is applied to control the pore-water and pore-air pressures. A soil-water retention curve (SWRC) is obtained for the CDG soil from the equilibrium water content corresponding to each applied matric suction value for zero net normal stress using a modified direct shear apparatus. Shear strength increases with matric suction and net normal stress, and the failure envelope is observed to be linear. The apparent angle of internal friction and cohesion intercept increase with matric suction. A greater dilation angle is found at higher suctions with lower net normal stresses, while lower or zero dilation angles are observed under higher net normal stresses with lower suctions, also at a saturated condition. Experimental shear strength data are compared with the analytical shear strength results obtained from a previously modified model considering the SWRC, effective shear strength parameters, and analytical dilation angles. The experimental shear strength data are slightly higher than the analytical results under higher net normal stresses in a higher suction range.
Keratinolytic activity from new recombinant fusant AYA2000, derived from endophyticMicromonosporastrains
Authors: El-Bondkly Ahmed M. , El-Gendy Mervat M.A.
Published: October 2010

Two different endophytic strains, ESRAA1997 and ALAA2000, were isolated from the Egyptian herbal plant Anastatica hierochuntica . The 2 strains produced alkaline serine protease and were identified based on their phenotypic and chemotypic characteristics as different strains of Micromonospora spp. Both strains grew and produced keratinase, using different keratinous waste substances as the sole source of carbon and nitrogen. In our study, the activity and properties of keratinase enzymes of the wild strains ESRAA1997 and ALAA2000 were altered by genetic recombination through protoplast fusion between them, leading to a potent keratinolytic fusant Micromonospora strain AYA2000 with improved properties (activity, stability, specificity, and tolerance to inhibitors). Using a mixture of yeast extract, peptone, and malt extract as a supplement to the bovine hair medium increased keratinase production by 48%, and addition of 1% glucose suppressed enzyme production by Micromonospora strain AYA2000. The enzyme was purified by ammonium sulphate precipitation and DEAE–cellulose chromatography followed by gel filtration. The molecular weight, estimated using SDS–PAGE, was 39 kDa. The enzyme exhibited remarkable activity towards all keratinous wastes used and could also adapt to a broad range of pH and temperatures, with optima at pH 11 and 60 °C. The enzyme was not influenced by chelating reagents, metal ions, or alcohols. These properties make AYA2000 keratinase an ideal candidate for biotechnological application.