bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility of standardized injury surveillance and reporting: a comparison of data from four Asian nations
Authors: Nakahara S , Jayatilleke A U , Ichikawa M , Marasinghe A , Kimura A , Yoshida K
Published: April 2008

Background:

To address the increasing number of injuries in developing countries, the World Health Organization (WHO) encourages the establishment of hospital-based surveillance systems and systematic data collection. Although a computerized system is preferable in terms of efficiency, many developing countries have difficulty accessing the appropriate resources.

Objectives:

To assess the possibility of comparing and sharing data among countries, and then to discuss the possibility of establishing an international data management system through the internet.

Methods:

A point-by-point comparison of data directories from injury surveillance systems in Thailand, Cambodia, Sri Lanka, and Japan was conducted using guidelines published by WHO as the standard.

Results:

Thailand, Cambodia, and Sri Lanka used data items that are comparable to each other and to WHO guidelines, with few, readily amenable, differences. The Japanese system used quite different data items.

Conclusions:

Data comparability suggests the feasibility of a global data management system that can store data from various countries. Such a system, if made accessible over the internet, would benefit resource-constrained countries by providing them with a ready-made framework to implement a surveillance system at low cost.
Effectiveness of multifaceted fall-prevention programs for the elderly in residential care
Authors: Cusimano M D , Kwok J , Spadafora K
Published: April 2008

Background:

Unintentional falls are particularly prevalent among older people and constitute a public health concern. Not much is known about the implications of multifaceted intervention programs implemented in residential care settings.

Objectives:

To evaluate the effectiveness of multifaceted intervention programs in reducing the number of falls, fallers, recurrent fallers, and injurious falls among older people living in residential care facilities.

Search strategy:

Comprehensive searches of Medline, PubMed, and EMBASE up to July 2007, the cited literature lists of each included study, and the internet engines Google Scholar, Yahoo, and Dogpile were performed to identify eligible studies.

Selection criteria:

Eligible studies for this review were those that had randomized, controlled trials with adequate follow-up study components in their design. Studies that included elderly people in residential care who participated in multifaceted falls-prevention programs were included.

Data collection and analysis:

Two authors independently extracted the necessary data. Studies were assessed for quality by the criteria of Downs and Black. The results of the included studies have been reviewed narratively.

Main results:

From 21 articles potentially relevant to the topic, five studies met the inclusion criteria and all were reasonably well conducted. Three reported significant reductions in the number of recurrent fallers, two reported significant reductions in the number of falls, and one reported significant reductions in the number of fallers. One other reported a reduction in the number of injurious falls in those who received the multifaceted prevention program compared with the control group. However, the analyses of this specific study were not based on intent-to-treat, so the effect of intervention on the number of injurious falls remains inconclusive. No study reported on adverse events, costs, or sustainability of the interventions.

Conclusions:

Multifaceted programs that encompass a wide range of intervention strategies have shown some evidence of efficacy. However, more well-designed research is required that assesses effects on injurious falls, quality of life, cost-effectiveness, and sustainability.
The Advocacy in Action Study a cluster randomized controlled trial to reduce pedestrian injuries in deprived communities: Figure 1
Authors: Lyons R A , Towner E , Christie N , Kendrick D , Jones S J , Hayes M , Kimberlee R , Sarvotham T , Macey S , Brussoni M , Sleney J , Coupland C , Phillips C
Published: April 2008

Background

Road trafficrelated injury is a major global public health problem. In most countries, pedestrian injuries occur predominantly to the poorest in society. A number of evaluated interventions are effective in reducing these injuries. Very little research has been carried out into the distribution and determinants of the uptake of these interventions. Previous research has shown an association between local political influence and the distribution of traffic calming after adjustment for historical crash patterns. This led to the hypothesis that advocacy could be used to increase local politicians knowledge of pedestrian injury risk and effective interventions, ultimately resulting in improved pedestrian safety.

Objective

To design an intervention to improve the uptake of pedestrian safety measures in deprived communities.

Setting

Electoral wards in deprived areas of England and Wales with a poor record of pedestrian safety for children and older adults.

Methods

Design mixedmethods study, incorporating a cluster randomized controlled trial. Data mixture of Geographical Information Systems data collision locations, road safety interventions, telephone interviews, and questionnaires. Randomization 239 electoral wards clustered within 57 local authorities. Participants 615 politicians representing intervention and control wards. Intervention a package of tailored information including maps of pedestrian injuries was designed for intervention politicians, and a general information pack for controls.

Outcome measures

Primary outcome number of road safety interventions 25months after randomization. Secondary outcomes politicians interest and involvement in injury prevention cost of interventions. Process evaluation use of advocacy pack, facilitators and barriers to involvement, and success.
Growth and differentiation in mechanically isolated mesophyll cells of Ipomoea quamoclit
Authors: Bhatt P. H. , Mehta A. R.
Published: April 2008

The present communication deals with induction of callus from mechanically isolated mesophyll cells of Ipomoea quamoclit Linn. Growth of the callus and potentiality for differentiation are also examined.
The fine structure of conidium development in Phialocephala dimorphospora
Authors: Carroll George C. , Carroll Fanny E.
Published: April 2008

Sequential developmental stages from synchronously sporulating cultures of Phialocephala dimorphospora Kendrick have been examined. Apical vesicles characterize growth of the primary conidium. These are not, however, seen during secondary conidium formation; instead, large vesicles containing minute membrane fragments develop just below the phialide neck and contribute to wall formation as they fuse with the plasmalemma. The occurrence of microtubules in the neck of the phialide is restricted to primary conidium formation. Just as the primary conidial initial begins to swell, electron-dense granules 50-75 nm in diameter arise in association with the plasmalemma. Such granules are not seen during secondary conidium formation; they are thought to be involved in pigment deposition in the collarette. During both primary and secondary conidium production the conidia go through a sequence of maturation in which the cytoplasm becomes very dense and contains lipid bodies and flocculent aggregations of electron-transparent granules. Subsequently the conidia become less electron dense and reveal a simple internal substructure consisting of a nucleus, mitochondria, micro-bodies, free ribosomes, and presumed storage bodies. The plasmalemma becomes convoluted in a network of interdigitated grooves. Septum formation occurs rapidly and involves the fusion of vesicles with the lateral wall. Mature septa are non-perforate. Although Woronin bodies have been repeatedly observed in young conidia, they are never seen in mature conidia. Myelin figures associated with mitochondria occur consistently in the body of the phialide during conidiation. These may be the source of the lipid bodies in the conidia. In phialides from cultures over 1 week old, signs of senescence are apparent. These include vacuolization of the upper portion of the phialide and the presence of many disorganized sheets of membrane. Spores still present within the collarette of such phialides are smaller than those produced early in the life of the phialide.
Ultrastructural studies of concentric bodies in the ascomycetous fungus Venturia inaequalis
Authors: Granett A. L.
Published: April 2008

Concentric bodies about 280 nm in diameter were often observed as inclusions in hyphae of the perithecial wall and infrequently were seen in the vegetative hyphae and conidiophores of Venturia inaequalis. These apparently spherical bodies were found singly or in clusters and consisted of several distinct layers. The inclusions appeared to be identical with those found in a number of lichen mycobionts.
Ectendomycorrhizae in Pinus resinosa seedlings. I. Characteristics of mycorrhizae produced by a black imperfect fungus
Authors: Wilcox Hugh E. , Ganmore-Neumann Ruth
Published: April 2008

A black imperfect fungus isolated from 3-year-old nursery seedlings of Pinus resinosa was tested for its ability to form mycorrhizae on red pine in monoxenic culture. It was found to stimulate seedling growth. The fungal invasion passed through three successive stages of development during the 7 months after inoculation. At 3 months, intracellular hyphae occurred in all long- and short-root branches, with intercellular hyphae scattered only at isolated loci in the intercellular spaces. After 5 months the infection in the cortex changed abruptly from an intracellular infection to a completely intercellular Hartig net. Although the Hartig net was remarkably thin when first initiated, at its culmination it reached a massive thickness and sent penetrating hyphae into the cortical cells, resulting in the formation of distinctive ectendomycorrhizae. By the end of 7 months the secondary intracellular invasions were often found in the vicinity of the meristems in all root branches except the largest-diameter long-roots, and the fungus-root association had developed toward a predominant ectendomycorrhizal condition. The ectendomycorrhizal infection was distinctively different from the one produced by the so-called E-strains that have been commonly observed in coniferous nurseries.
Floral development of Comptonia peregrina (Myricaceae)
Authors: Macdonald Alastair D.
Published: April 2008

Early stages of development of the male and female flower are similar; two second-order bracts arise in the transversal plane on either side of the floral apex before the apex flattens and becomes somewhat concave because of growth activity at the flank of the apex. In the female flower, the gynoecium develops as an extension of the girdling gynoecial primordium and the two primordial stigmas each result from more rapid growth in the median plane at the distal portion of the gynoecial wall. The floral apex resumes growth to form the unitegmic ovule. Third-order lanceolate-shaped bracts develop from a meristem situated in the axil of each second-order bract. In the male flower, staminate primordia arise at three or four loci on the ridge surrounding the apex. The apex briefly resumes growth. Growth of the second-order bracts terminates at an early stage. The floral construction is compared to other myricaceous species. It is concluded that the axillary scale-like bracts of the female flower are third-order bracts; the gynoecium does not overtop the second-order axis and the female flower is not a reduced cyme; the male flower is more floral- than inflorescence-like compared to some other myricaceous species.
Scanning electron microscopy of perithecial development in a species of Phyllactinia on oak
Authors: Harris James L. , Roth Ivan L.
Published: April 2008

A species of Phyllactinia on oak was examined by scanning electron microscopy. The naturally dried fungus was minimally manipulated in preparation for study. Development was followed by examining various stages from initial to mature perithecium. Immature perithecial appendages were found to be less rigid than those which had matured. The sticky apical mucilage droplet on the maturing perithecium was observed, but the penicillate cells that form the droplet were not easily seen. As the appendages dried they lifted the perithecium off the surrounding surface. Some perithecia were found that had overturned and adhered to the hyphae-covered leaf by means of the mucilage droplet. This study has resulted in visualization of Phyllactinia surface structure in more detail than heretofore reported. Other plant pathogenic fungi, especially those producing naturally dry mature fruiting bodies, should be amenable to study by this method.
Etude des modes de ramification sympodiale chez Lycopersicum esculentum et L. pimpinellifolium
Authors: Silvy A.
Published: April 2008

In Lycopersicum esculentum Mill, and L. pimpinellifolium Dun. ramification modes of plants with determinate and indeterminate habits are studied by macroscopic observation (apex evolution, phyllotaxis, and leaf number of the different branches of a mature plant) and also by analyzing mutated sectors after seed treatment. While the first inflorescence, a cyme, originates from the greater part of the prefloral apex, the top of which bears the first flower, second-order axes come up at the axils of the last two leaves. In all the varieties, the axillary bud of the second-last leaf produces a sympodial lateral ramification. On the other hand, that of the last leaf, which becomes visible on the side of the prefloral apex, as anticipated, immediately bears a second inflorescence in varieties with determinate habit, but makes up the second-order axis of the main sympodium in varieties with indeterminate habit. The characteristics of these two bud patterns are compared.
Effect of cotton root exudate constituents on growth and pectolytic enzyme production by Verticillium albo-atrum
Authors: Booth J. A.
Published: April 2008

New Mexico Acala cotton cultivar 8229 (Verticillium tolerant) exuded 3.5 times more choline from roots than did susceptible 1517-C cultivar. Other exuded growth factors were not significantly different between cultivars. The choline difference and the earlier discovery that alanine is exuded in greater quantities by the susceptible cultivar prompted an investigation into the effects of these metabolites on growth and pectic enzyme production by the pathogen. L-Alanine (0.002 M) increased Verticillium growth 320% (dry weight basis), but when 2.0 μg/ml choline was also added, growth was reduced to 41% of control cultures. Polygalacturonase activity was also stimulated by 0.002 M L-alanine (17.2 units/mg dry weight of growth vs. 10.4 units for control cultures). When choline was added, the activity was suppressed (7.4 units). Choline without L-alanine had little effect on growth or polygalacturonase production. When alanine was taken up by excised cotton seedlings or supplied in nutrient solution supplied to older plants before inoculation, the tolerance characteristic of cultivar 8229 was reversed.
Isolation and axenic culture of poplar rust
Authors: Lane W. David , Shaw Michael
Published: April 2008

Surface-sterilized leaf pieces of black cottonwood (Populus trichocarpa) leaves centered on uredial infections of Melampsora occidentalis Pers. were placed, pustule side up, on a defined, agar-based medium. After 4 months the fungus became established on the medium. Axenic colonies, some of which produced urediospores, were established by transfer to fresh medium and were capable of reinfecting excised leaf pieces of the host. The technique bypasses germling development in vitro. This is the first report of the axenic culture of Melampsora occidentalis.
The economic value of plant systematics in Canadian agriculture
Authors: Small Ernest
Published: April 2008

Agriculture is like a house, resting on a foundation of biological systematics. That foundation is seriously deteriorating, in part because of lack of appreciation of its vital roles and economic relevance. Support for biological sciences is concentrating in seemingly lucrative disciplines, without much realization that the financial benefits often can not be realized without the materials and information provided by systematics. A variety of considerations supports the economic wisdom of investing in systematics research in Canada, most particularly on behalf of the agricultural sector, and suggest that failure to do so could lead to serious, even catastrophic, consequences. In particular, the present scarcity of expertise for identification of vanishing invaluable wild crop germ plasm may permanently penalize both agriculture and society. While it is essential that systematists retain their fundamental orientation to the clarification and cataloging of biological diversity, emphasis on the useful roles played and products produced is both an economic necessity and a social responsibility. Key words: plant, systematics, taxonomy, agriculture, economic.
Mycorrhizae of Japanese black pine (Pinus thunbergii): protection of seedlings from acid mist and effect of acid mist on mycorrhiza formation
Authors: Maehara Noritoshi , Kikuchi Junichi , Futai Kazuyoshi
Published: April 2008

To determine the effects of acid precipitation on Japanese black pine (Pinus thunbergii Parl.) with and without mycorrhizae (Pisolithus tinctorius (Pers.) Coker et Couch), 1-year-old seedlings were exposed to simulated acid mist, pH 3.0, for 10 min per day twice a week for 3 or 4 months. Simulated acid mist adversely affected the transpiration rate and lowered the extractable phosphorus content of seedlings, but seedlings with mycorrhizae were less affected by acid mist than were nonmycorrhizal seedlings. Simulated acid mist also retarded mycorrhiza formation. Key words: mycorrhizae, phosphorus content, Pinus thunbergii, Pisolithus tinctorius, simulated acid mist, transpiration rate.
A bicarbonate-containing medium for the solution culture of submersed plants
Authors: Smith Craig S.
Published: April 2008

A bicarbonate-buffered hard-water medium was evaluated for the solution (nonrooted) culture of submersed aquatic plants. The new medium had an initial pH of 8.2, and after 2 weeks of plant growth in it, pH values remained similar to those in hard-water lakes. Several plants from hard-water lakes grew more rapidly in the new medium than in the commonly used Gerloff medium. When cultures were aerated with air, Myriophyllum spicatum growth was nearly twice as great in the new medium as in Gerloff medium, and growth of Vallisneria americana and Elodea canadensis in the new medium was 4 and 13 times that in Gerloff medium, respectively. When both cultures were aerated with 1% CO2, growth rates of M. spicatum and E. canadensis in the new medium were not distinguishable from those in Gerloff medium, but the growth of V. americana was 40% greater in the new medium. Myriophyllum spicatum was much less susceptible to attack by the fungal pathogen Colletotrichum gloeosporioides in the new medium than in Gerloff medium, similar to the susceptibility shown in nutrient-amended lake water. Key words: aquatic plants, culture techniques, plant pathogens.
A synopsis with keys for the genus Antennaria (Asteraceae: Inuleae: Gnaphaliinae) of North America
Authors: Bayer Randall J. , Stebbins G. Ledyard
Published: April 2008

Keys to all species of Antennaria of North America and Mexico are presented. The number of taxa acknowledged in the current treatment is 46, including 35 species with 17 subspecies circumscribed among some of the more diverse species. The treatment is a highly conservative one, considering the fact that over 350 taxa of Antennaria have been described for North America, the majority in the last 100 years. A synopsis enumerates all the recognized taxa and provides their correct name, widely used synonyms, basionym, type locality, key morphological features, and assorted taxonomic notes. The new combinations, Antennaria friesiana (Trautv.) Ekman ssp. neoalaskana (A.E. Pors.) Bayer & Stebbins comb, et stat.nov. and Antennaria luzuloides Torr. & A. Gray ssp. aberrans (E. Nels.) Bayer & Stebbins comb.nov., are proposed. Key words: Antennaria, Asteraceae, Compositae, Inuleae, taxonomic revision, Flora of North America.
Cauline meristems in leptosporangiate ferns: structure, lateral appendages, and branching
Authors: Hébant-Mauri R.
Published: April 2008

This study on shoot apical meristem structures in leptosporangiate ferns examines the precise initiation of lateral appendages in the meristems. Interrelationships and early development of the main stem, fronds, and branches are described. Ontogeny and histology within the apical meristem must be considered in a reasonable morphological interpretation of the adult plant, especially with respect to the lateral system (i.e. frond and bud assemblage) in creeping branched ferns. Key words: branching, lateral initiations, meristem structure, morphology, ontogeny.
Seasonal dynamics of dominant species of arbuscular mycorrhizae in burned and unburned sand prairies
Authors: Dhillion Shivcharn S. , Anderson Roger C.
Published: April 2008

Seasonal variation in abundance of spores of arbuscular mycorrhizal fungi was examined for four growing seasons on burned and unburned sand prairies in Illinois. The three leading mycorrhizal species were an undescribed species of Glomus, Scutettospora heterogama, and Sclerocystis rubiformis, in order of decreasing abundance. Mycorrhizal spore abundance for all species generally showed similar seasonal patterns on burned and unburned sites during the sampling period, i.e., minimal in the middle of the growing season and maximal near the end of the season. Individual species, however, exhibited different seasonal patterns of sporulation or sporulation strategies. Burning caused a 2-year depression in spore abundance for Glomus species and Scutellospora heterogama, and a 3-year long depression in spore abundance for Sclerocystis rubiformis. The seasonal patterns observed were more discernible in root zone than in randomly collected soil. Spore abundances were always significantly lower on burned sites than on unburned sites early in the growing season. The results of this study, and studies conducted parallel to this one, suggest that the greater decline in spore abundance in burned sites than in unburned sites early in the growing season may be indirectly due to greater root growth, and (or) related changes in host physiology, in response to fire. Key words: mycorrhizae, fire, sand prairie, grassland, sporulation, inoculum, fungi.
Limited taxonomic value of palea intercostal characteristics in North American Festuca (Poaceae)
Authors: Consaul L. L. , Aiken S. G.
Published: April 2008

Morphology of the intercostal palea region of 34 Festuca species found in North America was investigated using scanning electron microscopy. Palea epidermal features are most diverse in the palea apical region and fully developed in florets approaching anthesis. The intercostal region has long cells 3–15 times longer than wide, with walls that vary from slightly to prominently thickened, and from almost straight to strongly undulate. This variation was observed among paleas collected from different locations and sometimes even on a single palea. The distribution of short cells, almost square in outline, among the long cells varied with species from solitary to paired and from abundant to sparse. Four forms of trichomes were recorded: papillae, hook trichomes, prickle hairs, and macrohairs, with one form usually predominating per species. Silicon was detected in some short cells and commonly in the tips of trichomes. A key to species groups is presented. Key words: scanning electron microscopy, palea, trichomes, silicon, epidermal features, Festuca.
The origin of the Lotus corniculatus (Fabaceae) complex: a synthesis of diverse evidence
Authors: Grant William F. , Small Ernest
Published: April 2008

Lotus corniculatus, birdsfoot trefoil, is a Eurasian perennial legume, popular in temperate climates for pasture or hay and silage production. Its ancestry is controversial. While innumerable studies of L. corniculatus and allied species have been published, comprehensive morphological, geographical, and genetic studies are still needed. Nevertheless, there is sufficient information for a provisional analysis of the origin and relationships of this important economical species. Although sometimes defined to have diploid populations, L. corniculatus essentially appears to be tetraploid. Biochemical and genetic evidence indicates that this species is an allotetraploid. Although about a dozen diploid species have been proposed as ancestral to L. corniculatus, the evidence points strongly to four of these species. Lotus uliginosus uniquely shares a rhizomatous habit, an acyanogenic factor, and a tannin characteristic with L. corniculatus, clearly showing an especially close relationship, and reflecting the possibility that it is one of two direct parental species. Principal candidates for a second parent include Lotus alpinus, Lotus japonicus, and Lotus tenuis. A phenetic analysis presented here accords well with the hypothesis favoured in this paper that L. corniculatus arose as a hybrid of L. tenuis and L. uliginosus. Cytogenetic evidence indicates that L. japonicus is especially closely related to L. corniculatus. Flower colour in the hybrids between L. uliginosus and L. tenuis suggest maternal inheritance and that L. tenuis could have been the female parent. An evolutionary sequence is suggested in which L. uliginosus hybridized with L. tenuis followed by introgression from L. alpinus and L. japonicus. Alternatively, a prototype of L. alpinus, L. japonicus, and L. tenuis could have been the female parent of L. corniculatus, based on evidence from maternal inheritance of flower colour intensity and interactions of Rhizobium strains. Keywords: polyploidy, hybridization, evolution, Lotus species, Fabaceae, birdsfoot trefoil, Lotus corniculatus.
Identification and microgeographic distribution of Mazzaella splendens and Mazzaella linearis (Gigartinaceae, Rhodophyta)
Authors: Shaughnessy Frank J.
Published: April 2008

Existing descriptions of the sister species Mazzaella splendens and Mazzaella linearis were insufficient to identify all low intertidal Mazzaella thalli along a wave exposure gradient in Barkley Sound, British Columbia. After sampling size classes of sporophytes and gametophytes, uni- and multi-variate analyses indicated that thalli at low and intermediate exposure sites were M. splendens, whereas thalli at the high exposure site were M. linearis. The longer and thicker stipe of M. linearis best distinguishes it from M. splendens, whereas the previously emphasized characters of blade width and angle at the blade base were not useful. The latter characters demonstrated gradual clines, and for the longer size class, blade width was not isomorphic between phases. The species alternated with each other along the shoreline depending on how rock topography influenced the arrangement of low, intermediate, and high wave exposure sites. Regressions that used an indicator of water motion (i.e., sucrose candy weight loss) to predict morphological variation were often significant. These regressions suggest that some factors affecting the distribution of M. splendens and M. linearis along the gradient are the degree of wave exposure itself as well as light and nutrient availability. Keywords: Mazzaella, Iridaea, cline, wave exposure, gametophyte, sporophyte.
Callose deposition in the primary wall of suspension cells and regenerating protoplasts, and its relationship to patterned cellulose synthesis
Authors: Amstel Ton N. M. van , Kengen Harry M. P.
Published: April 2008

Monitoring cell-wall formation in vivo with Fluorescent Brightener 28, by fluorescence microscopy, revealed that tobacco protoplasts regeneration started within 30 min indicated by cellulose microfibril formation at distinct sites on the protoplast surface. Oriented cellulose microfibril deposition was apparent before elongation and indicated the early polarization of protoplasts. The sequence of cellulose microfibril deposition correlates with an helicoidal-like texture. Within 6 h, a texture was completed. Tobacco suspension cells, stained by decolourized aniline blue, showed radiant granular callose fluorescence in cell plates and transverse walls. During the culture cycle of suspension cells, transverse fibrillar deposits of callose gradually appeared in the lateral walls during the log-phase, and subsequently disappeared in the early stationary phase of the cell culture. Similar callose transitions were observed in regenerated elongating protoplasts. Culture cells of Morinda citrifolia L. only showed transient granular depositions in the lateral walls. The callose formations did not result from artificial wounding. The transient appearance of callose might be related to cellulose microfibril deposition. Keywords: aniline blue, Calcofluor White ST, callose, cellulose, Fluorescent Brightener 28, Morinda citrifolia, Nicotiana tabacum.
Isozyme diversity among hard pine stem rust fungi in the western United States
Authors: Vogler D. R. , Cobb Jr. F. W. , Geils B. W. , Nelson D. L.
Published: April 2008

Isozyme analysis was used to determine species relationships and diversity among stem rust fungi (Cronartium and Peridermium spp.) infecting hard pines (subg. Pinus) in the western United States. Electrophoresis was carried out on aeciospore extracts of 270 hard pine stem rust isolates representing nine species and forms. Consistent banding patterns (electromorphs interpreted as phenotypes) were obtained for all isolates at 11 enzyme loci. Within species groups, multilocus phenotypes were diverse at several loci. Nevertheless, each species exhibited a unique set of phenotypes that distinguished it from all others. For diagnostic purposes, banding patterns from just two loci were sufficient to distinguish all species and most forms or races examined. Two taxa that were thought to be forms of existing species may be new, undescribed species. For comparison with western hard pine stem rusts, multilocus phenotypes were determined for 13 additional isolates of four related pine stem rust species. Phenotypes for all rust species were analyzed in all possible combinations using pairwise distance analysis (neighbor-joining). When Cronartium ribicola is treated as the outgroup, the resulting phenogram groups all 72 multilocus phenotypes into distinct species clades. Origins of autoecious, short-cycled Peridermium spp. may be inferred from their placements relative to macrocyclic, heteroecious Cronartium spp. Keywords: Cronartium, Peridermium, species diversity, species relationships.
Genetic variation in populations of the endemicAchillea millefoliumssp.megacephalafrom the Athabasca sand dunes and the widespread ssp.lanulosain western North America
Authors: Purdy Brett G. , Bayer Randall J.
Published: April 2008

As part of an analysis of genetic diversity in endemic taxa of the Athabasca sand dunes in northern Saskatchewan, Canada, genetic variation was examined by starch gel electrophoresis in six populations of the endemic Achillea millefolium ssp. megacephala, and 13 populations of the closely related widespread taxon, A. millefolium ssp. lanulosa. Endemic populations had more alleles per locus, a higher percentage of polymorphic loci, and greater genetic diversity than did populations of the widespread taxon. At polymorphic loci, total gene diversity was comparable in both taxa, although within-population gene diversity was higher in the endemic taxon. Population differentiation (GST) was considerably lower in ssp. megacephala than in ssp. lanulosa, although GSTvalues were reduced when the parameter was calculated separately for geographic subdivisions of the widespread taxon. Our results differ from previous studies in which the endemic is typically depauperate of genetic variation relative to related widespread species. We suggest that obligate sexual reproduction and the absence of long-term asexual reproduction may be one of a number of factors that help populations of ssp. megacephala maintain higher levels of genetic variation on the Athabasca sand dunes. Keywords: genetic variation, endemic, rare species, Athabasca sand dunes, Achillea millefolium.
Large globoid particles in the cotyledons of Cucurbita maxima seedlings
Authors: Pitt Michael W. , Lott John N. A.
Published: April 2008

Light microscopy and transmission electron microscopy revealed the location of previously identified large protein body globoids within the cotyledons of Cucurbita maxima seedlings. Large globoids formed in the three cell layers of the spongy mesophyll above the lower epidermis. The large globoids share morphological similarities to typical globoids by being spherical and naturally electron dense, but they were approximately four times the size of regular globoids, ranging from 4 to 8 μm in diameter. The formation of the large globoid particles occurred around 3 days of seedling growth and likely resulted from fusion of a number of typically sized globoids. This method of formation was supported by the appearance of clusters of regular globoids prior to the formation of the unusually large globoids. The volume of a large globoid was less than the combined volume of all the typical-sized globoids found within a mesophyll cell earlier in seedling growth. Keywords: large globoids, cotyledon, Cucurbita maxima, mesophyll, seedling, protein bodies.
Fitness distribution and transgressive segregation across 40 environments in a hybrid progeny population of the human-pathogenic yeastCryptococcus neoformans
Authors: Shahid Morvarid , Han Susan , Yoell Heather , Xu Jianping
Published: April 2008

The opportunistic human fungal pathogen Cryptococcus neoformans includes two varieties, C. neoformans var. grubii and C. neoformans var. neoformans, which correspond to serotypes A and D, respectively. Recent population genetic studies revealed that multiple natural hybridizations have occurred recently between these two divergent lineages. However, the biological effects of such hybridizations are little understood. In this study, we used colony size as a proxy for vegetative fitness to examine the phenotypic effects of hybridization between these two lineages in a laboratory cross. Two genetically diverged parental strains that differed in their growth at different temperatures and on different media as well as in their susceptibility to the common antifungal drug fluconazole were chosen. A total of 269 progeny were obtained and their vegetative growth was determined in 40 environments that differed in nutrients, temperature, and fluconazole concentration. Our analyses indicated little evidence for outbreeding depression or heterosis in the average vegetative fitness of the hybrid progeny population. The progeny, each of the three environmental variables, and their two-way, three-way, and four-way interactions all contributed significantly to the overall vegetative fitness variation. Interestingly, a variable number of progeny displayed evidence of transgressive segregation in vegetative fitness among the tested environments. Our study suggests that hybridization could play a significant role in the phenotypic evolution of this important human-pathogenic fungus.
Genetic and epigenetic changes of rDNA in a synthetic allotetraploid, Aegilops sharonensis × Ae. umbellulata
Authors: Shcherban A. B. , Badaeva E. D. , Amosova A. V. , Adonina I. G. , Salina E. A.
Published: April 2008

The synthetic allotetraploid Aegilops sharonensis × Ae. umbellulata (genomic formula SshU) was used to study inheritance and expression of 45S rDNA during early stages of allopolyploid formation. Using silver staining, we revealed suppression of the NORs (nucleolar organizing regions) from the Ssh genome in response to polyploidization. Most allopolyploid plants of the S2–S4 generations retained the chromosomal location of 45S rDNA typical for the parental species, except for two S3 plants in which a deletion of the rDNA locus on one of the homologous 6Ssh chromosomes was revealed. In addition, we found a decrease in NOR signal intensity on both 6Ssh chromosomes in a portion of the S3 and S4 allopolyploid plants. As Southern hybridization showed, the allopolyploid plants demonstrated additive inheritance of parental rDNA units together with contraction of copy number of some rDNA families inherited from Ae. sharonensis. Also, we identified a new variant of amplified rDNA unit with MspAI1 restriction sites characteristic of Ae. umbellulata. These genetic alterations in the allopolyploid were associated with comparative hypomethylation of the promoter region within the Ae. umbellulata–derived rDNA units. The fast uniparental elimination of rDNA observed in the synthetic allopolyploid agrees well with patterns observed previously in natural wheat allotetraploids.
Cytomorphological and molecular diversity in backcross-derived inbred lines of sunflower (Helianthus annuusL.)
Authors: Sujatha M. , Prabakaran A. J. , Dwivedi Sangam L. , Chandra S.
Published: April 2008

A set of 250 distinct, stable, and uniform backcross-derived inbred lines were developed in sunflower through 5 interspecific cross combinations involving 4 wild diploid annual species ( Helianthus argophyllus , H. petiolaris , H. annuus , and H. debilis ). The presence of the wild-species genome in these inbred lines was confirmed through higher chromosome associations (tri- and quadrivalents) at diakinesis. Maximum structural rearrangements of chromosomes were observed in lines derived from H. petiolaris. Forty morphologically diverse inbred lines along with 2 controls were subjected to measurements of phenotypic and genetic distance using 118 simple sequence repeat (SSR) markers of known map location. A total of 204 alleles were identified and the number of alleles per locus varied between 2 and 5. There were 46 unique alleles and the number of unique alleles was highest in the lines derived from the cross involving H. petiolaris. The polymorphism information content (PIC) values ranged from 0.05 to 0.575. The pair-wise comparison values based on genetic dissimilarity estimates computed using molecular marker data varied between 0.143 and 0.486 among the 42 lines. The results indicate that the sunflower gene pool could benefit from introgression of novel alleles from the latent genetic diversity present in the wild species and particularly through exploitation of the diploid annual H. petiolaris.
Modeling the effect of agricultural best management practices on water quality under various climatic scenarios
Authors: Parker G. T. , Droste R. L. , Kennedy K. J.
Published: April 2008

The South Nation (SN) watershed in Eastern Ontario was studied for improvements in surface water quality due to best management practices (BMPs). Contributions of non-point sources (NPS) to nutrient loadings are both significant and poorly defined in the region. The study used the dynamic Annualized Agricultural NPS (AnnAGNPS) model to run continuous annual simulations, coupled with a dynamic water-quality model for simulation of riverine water chemistry. The simulation case matrix focused on the potential of BMPs within the context of climate change. Results of the work were then analyzed to determine ecological intensity (severity), duration, and frequency (IDF) of violations to species survivability within the stream network. Best management practices were found to reduce water quality impacts but stream standards were not reached. Adjustment of fertilizer application rates (FAR) and vegetative filter strips (VFS) outperformed alternative BMPs in the model. Results suggest that agricultural activity within the watershed must be diminished to reach standards.
Improving the evaluation of filtration robustness
Authors: Li Tong , Huck Peter M.
Published: April 2008

Drinking water filtration systems should be as robust as possible to consistently provide finished water of high quality to protect public health. The quantification of robustness makes it possible to evaluate the status of a given system. This paper introduces a newly developed turbidity robustness index, which differentially weights average performance and deviations from average. A second new robustness evaluation method — the probability method — was also developed. This method provides the basis to implement almost real-time online monitoring of filtration robustness as the filter cycle develops. This may be particularly useful in smaller systems, which usually have less direct operator oversight. Both of the newly developed robustness approaches were applied to assess filtration turbidity performance at selected full-scale water treatment plants.
Process water treatment in Canada’s oil sands industry: I. Target pollutants and treatment objectives
Authors: Allen Erik W.
Published: April 2008

Process water treatment has become a critical issue for Canada’s oil sands industry. Continuous recycling of tailings pond water (TPW) has contributed to a decline in water quality that has consequences for bitumen recovery, water consumption, and reclamation efforts. Potential roles for water treatment were assessed through a review of process water quality and toxicity data from two long-term oil sands operations. Target pollutants were identified according to exceedances of environmental and industrial water quality guidelines. From 1980 to 2001, the salinity of TPW increased at a rate of 75 mg/L per year. Recent increases in hardness, sulphate, chloride, and ammonia have raised concerns over scaling and corrosion. Naphthenic acids released during bitumen extraction are the primary source of toxicity in TPW. Biodegradation of naphthenic acids has been demonstrated in pond experiments;; however, recalcitrant compounds may contribute to chronic toxicity in reclaimed environments. Water treatment objectives established in this review provide benchmarks for the selection of candidate water treatment technologies.
Microwave enhanced advanced oxidation process for sewage sludge treatment: The effects of ozone addition
Authors: Yin G.Q. , Lo K.V. , Liao P.H.
Published: April 2008

Microwave enhanced advanced oxidation processes (MWAOP), with combinations of oxidants, were studied for sewage sludge treatment. Various operating conditions, using a computer statistical software design, were selected to determine the importance of factors affecting solids destruction and nutrients release from sewage sludge. For phosphate solubilization, the most significant factors, in the order from most to least, are heating temperature, ozone dosage, and a combined effect of temperature and hydrogen peroxide. For ammonia release, these are hydrogen peroxide dosage, a combined effect of hydrogen peroxide and temperature, and then temperature and ozone. For the destruction of sludge particles, the most significant factors are hydrogen peroxide and temperature. The best solubilization result was obtained with additions of 2% hydrogen peroxide by weight, 5.09 mg/mL of ozone, and microwave heating at 120 °C. About 95%, 32%, and 78% of TP, TKN, and COD were released into the solution, respectively. Results showed that addition of ozone improved the MWAOP process. A higher amount of oxidants used in the MWAOP facilitated the release of nutrients and sludge solids disintegration.
Ultrastructural localization of heavy metals in the extraradical mycelium and spores of the arbuscular mycorrhizal fungusGlomus intraradices
Authors: González-Guerrero Manuel , Melville Lewis H. , Ferrol Nuria , Lott John N.A. , Azcón-Aguilar Concepción , Peterson R. Larry
Published: April 2008

Arbuscular mycorrhizal fungi, obligate symbionts of most plant species, are able to accumulate heavy metals, thereby, protecting plants from metal toxicity. In this study, the ultrastructural localization of Zn, Cu, and Cd in the extraradical mycelium and spores of the arbuscular mycorrhizal fungus Glomus intraradices grown in monoxenic cultures was investigated. Zinc, Cu, or Cd was applied to the extraradical mycelium to final concentrations of 7.5, 5.0, or 0.45 mmol/L, respectively. Samples were collected at time 0, 8 h, and 7 days after metal application and were prepared for rapid freezing and freeze substitution. Metal content in different subcellular locations (wall, cytoplasm, and vacuoles), both in hyphae and spores, was determined by energy-dispersive X-ray spectroscopy. In all treatments and fungal structures analysed, heavy metals accumulated mainly in the fungal cell wall and in the vacuoles, while minor changes in metal concentrations were detected in the cytoplasm. Incorporation of Zn into the fungus occurred during the first 8 h after metal addition with no subsequent accumulation. On the other hand, Cu steadily accumulated in the spore vacuoles over time, whereas Cd steadily accumulated in the hyphal vacuoles. These results suggest that binding of metals to the cell walls and compartmentalization in vacuoles may be essential mechanisms for metal detoxification.
Comparison of treatment efficacy and stability of microbial populations between raw and anaerobically treated liquid pig manure, using PCR–DGGE and 16S sequencing
Authors: Bouity-Voubou Maurice Dieudonné , Frigon Jean Claude , Guiot Serge , Brousseau Roland
Published: April 2008

The effects of adding an adapted inoculum to liquid pig manure (LPM) prior to anaerobic digestion were evaluated by standard analytical methods. In parallel, the phylogenetic diversity of the microbial community of raw and anaerobically digested pig manure was studied by both denaturing gradient gel electrophoresis (DGGE) and sequence analysis of 16S rRNA fragments amplified by polymerase chain reaction. Gas production, volative fatty acid production, removal of soluble chemical oxygen demand, and removal of volatile soluble solids were measured on raw and on inoculated liquid pig manure subjected to anaerobic digestion. DGGE profiles of 16S rRNA genes were used to compare the major elements of the bacterial community composition in raw LPM with those present under various incubation conditions. Major bands were excised and sequenced to gain insight into the identities of the bacterial populations from LPM treated under different conditions. The results show that the addition of an adapted inoculum did not have a major impact on the conversion of pig manure into soluble organic matter and did not significantly change the microbial populations present during anaerobic digestion of LPM. Bacterial composition also indicated that Clostridium species are important constituents of the LPM community.
Plesiomonas shigelloides hugZ encodes an iron-regulated heme binding protein required for heme iron utilization
Authors: Oldham Athenia L. , Wood Trisha A. , Henderson Douglas P.
Published: April 2008

Plesiomonas shigelloides is an intestinal pathogen that uses heme as an iron source. The P. shigelloides heme utilization system consists of 10 genes, 7 of which permit heme transport and 3 of which are associated with utilization of heme as an iron source once it is inside the cell. The goal of this study was to examine hugZ, 1 of the 3 genes associated with utilization of heme iron. DPH8, a hugZ mutant, failed to grow to full cell density in media containing heme as the iron source, indicating that hugZ is required for heme iron utilization. Western blots using antibodies against Vibrio cholerae HutZ to detect the P. shigelloides HugZ indicated that hugZ encodes an iron-regulated cytoplasmic protein, which is absent in DPH8. A heme affinity bead assay performed on soluble protein fractions from P. shigelloides DPH8/pHUG24.5 (pHUG24.5 encodes hugZ) indicated that HugZ binds heme. Heme utilization was restored in DPH8 by hox1, which encodes the α-heme oxygenase from Synechocystis sp. strain PCC6803. However, HugZ did not exhibit α-heme oxygenase activity in an assay that detects the conversion of heme to the bilin functional group present in phycobiliproteins. These results do not rule out that HugZ exhibits another type of heme oxygenase activity not detected in the assay.