Diversity of the composition and content of soluble carbohydrates in seeds of the genus <Emphasis Type="Italic">Vicia</Emphasis> (Leguminosae)

Low molecular weight carbohydrates of seeds of 10 species of Vicia, namely: V. angustifolia, V. articulata, V. cordata, V. ervilia, V. johannis, V. macrocarpa, V. monantha, V. narbonensis, V. pannonica and V. sativa were analyzed by the high resolution gas chromatography method. Seeds of the investigated species contain common (glucose, fructose, myo-inositol, sucrose, galactinol, di-galactosyl myo-inositol and raffinose family oligosaccharides—RFOs) and species-specific carbohydrates (d-pinitol and its α-d-galactosides—in V. articulata, V. monantha and V. pannonica or d-ononitol and its galactoside—in V. ervilia). Among the species containing in seeds RFOs as the main α-d-galactosides (V. angustifolia, V. cordata, V. johanensis, V. macrocarpa, V. narbonensis and V. sativa), an additional subgroup can be separated, which contains a set of unknown compounds (found in V. angustifolia, V. cordata and V. macrocarpa). Moreover, several other unidentified carbohydrate-containing compounds were detected exclusively in seeds of V. ervilia. The concentrations of total soluble carbohydrates (TSCs), including sugars, RFOs, cyclitols and galactosyl cyclitols and unknown compounds, in seeds differ significantly (P < 0.05) among the species. RFOs and sucrose are the main fractions in TSCs, with the exception of V. pannonica seeds, containing more galactosyl pinitols, and V. ervilia, in which unknown compounds account for 50% of TSCs. In V. ervilia RFOs occur at the lowest concentration (9.32 mg g^?1 seeds), and the concentration of DGMI (di-galactosyl myo-inositol) is comparable with that of RFOs, which is unusual among all the investigated Vicia species.     

A 10-year evaluation of the functional basis for regeneration habitat preference of trees in an African evergreen forest

The spatial distribution of tree juveniles in relation to light environments may reflect species differences in growth, survival, and functional traits and will shape the nature of forest regeneration. Long-term field experiments are important to evaluate this issue because of the potentially very long juvenile period in trees. Here, we combine a 10-year seedling survival–growth data with the results of community ordination and multivariate analyses of functional traits to ask how observed juvenile light guilds are related to species functional traits and seedling performance. We transplanted seedlings at a standardized height of 11 cm into the shaded understory and quantified their growth and survival for 10-years. Using the community-wide stem distribution data, we categorized 33 species including the focal 11 species to understory vs. gap/edge guilds. Then, we determined differences between the two guilds in seedling survival, growth, as well as seed size, adult height, and a series of leaf traits, including toughness and chemical traits (fiber, protein, phenolics, tannins, alkaloids, saponins). Among the 11 non-pioneer species whose seedlings were planted into the understory, there was no significant difference in 10-year survival between light guilds, but species in gap/edge guild tended to achieve greater height than species in the understory guild. The leaf chemical traits of 33 species did not differ between the two juvenile light guilds, but gap/edge species had smaller seeds, taller adults, and tougher leaves than understory species. We used logistic regression as a complementary approach to assess the extent to which plant traits varied between light guilds and the most parsimonious model based on AIC_c ranking included only leaf toughness and had an Akaike weight of 0.52. In addition, across the 11 species planted as seedlings, these traits were not significantly related to survivorship or growth over 10 years. A Principle Components Analysis illustrated associations among traits. We conclude that light guilds in terms of juvenile stem distribution could not be explained by long-term field performance of post-establishment seedlings alone. Earlier seedling stage or later sapling stage may be more important in differentiation of light guilds. For the species examined difference in growth rates could be linked to seed size and adult stature, but not to the adult leaf chemical traits considered. These results suggest the importance of examining ontogenetic shifts and relationships among functional traits for a better understanding of regeneration strategies of tropical trees.     

US grower perceptions and experiences with glyphosate-resistant weeds

BACKGROUND: A survey of 400 growers of maize, soybeans and cotton was made in the United States to determine perceptions, experiences and management practices with glyphosate-resistant weeds. The survey included growers in the north (corn belt) and south (cotton belt) of the USA in spring 2006. RESULTS: Interestingly, 24 and 39% of northern and southern growers, respectively, assumed they had glyphosate weed resistance on their farm. Of the 200 southern growers interviewed, 67% had planted continuous glyphosate-resistant (GR) crops for a period of 3-5 years. According to the survey respondents, the key method for managing glyphosate-resistant weeds was to rotate to other herbicides. CONCLUSION: Growers do value GR crop technology but are adopting measures to manage resistance only as needed.     

Toxicity and binding of copper,zinc, and cadmium by the blue-green alga,Chroococcus paris

The toxic effects and accumulation of the heavy metals, Cd, Cu, and Zn by the sheath forming blue-green alga Chroococcus paris were investigated. All three of the metals were bound rapidly. Approximately 90% of the total amount of the added metal was bound within 1 min. Further significant binding occurred at a slower rate. The maximum metal binding capacity, as determined by filtration studies, was determined to be 53, 120, and 65 mg g^?1 dry algal weight for Cd, Cu, and Zn, respectively. Binding curves for the metals followed the Langmuir adsorption isotherm model. The amount of metal bound increased with increasing pH. Metal binding increased significantly when pH was increased from 4 to 7. Nearly all of the metal was found to be rapidly EDTA extractable. Metals were found to be increasingly toxic to growing cultures in the order, Zn, Cd, and Cu. All of the metals studied exhibited toxic effects at concentrations greater than 1.0 mg L^?1. The lowest concentrations used which showed detectable toxicity were 0.1 mg L^?1 for Cu and >0.4 mg L^?1 for Cd and Zn.     

A review of the role of the physicochemical environment in the production of certain floc properties

The aggregation of suspended particles in water and wastewater treatment processes is one of the oldest practices in solid-liquid separation. However, most treatment operations at least occasionally experience poorly settling flocs or extensive deagregation. These problems, and the increasing attention paid to sludge volume reduction and product water quality, have stimulated interest in floc behavior and aggregate characteristics. And although it is clear that overall process performance may depend upon floc properties such as size, strength, density and permeability, these floc attributes are the result of the interaction of nonlinear, stochastic hydrodynamics with the products of a number of sequential and concurrent physicochemical processes. Failure to understand these interactions has constrained efforts to improve the design and operation of coagulation processes.     

Clinical efficacy of a single injection of ceftiofur crystalline free acid sterile injectable suspension versus three daily injections of ceftiofur sodium sterile powder for the treatment of footrot in feedlot cattle

A study was conducted in a feedlot in Alberta, Canada, to compare the clinical efficacy of a single injection of ceftiofur crystalline free acid sterile injectable suspension with three daily treatments of ceftiofur sodium sterile powder for the treatment of footrot. Use of a long-acting antimicrobial to treat footrot would reduce labor costs and hospital pen space requirements during high-risk periods. Four hundred cattle clinically diagnosed with footrot were systematically randomized to one of two treatment groups. The treatment success rate at 14 days after treatment (99.5% for ceftiofur crystalline free acid sterile injectable suspension and 99.0% for ceftiofur sodium sterile powder for injection) was not statistically different (P>.05) between the two drugs.     

Ertragsreaktion von wintergerste im internationalen organischen stickstoffdauerdüngungsversuch (IOSDV) WROClaw-swojec

Wintergerste in der Fruchtfolge: Zuckerrüben--Sommerweizen--Wintergerste reagierte auf die mineralische N-Düngung stärker als auf die organische Düngung. Der maximale Kornertrag (5,10 t/ha) wurde bei 135 kg N/ha der organischen Düngungsvariante mit Biokompost zur Zuckerrübe erreicht. Winter barley cultivated in crop rotation: sugar beet, spring wheat, winter barley reacted more on differentiated rates of mineral nitrogen than on various organic fertilization. Winter barley yielded highest (5,10 t/ha) upon the effect of 135 kg N/ha after vermicompost application under sugar beet.     

Prevalence of methicillin-resistant staphylococci in canine pyoderma cases in primary care veterinary practices in Canada: A preliminary study

Pyoderma in dogs is most commonly caused by Staphylococcus spp., and significant emergence of methicillin resistance in staphylococcal pyoderma has been reported. This preliminary study of the prevalence of methicillin resistance in canine pyoderma cases in Canadian primary care veterinary practices revealed that methicillin-resistant Staphylococcus spp. were present in 12.1% of 149 staphylococcal positive skin culture cases.     

Habitat alteration and habitat fragmentation differentially affect beta diversity of stream fish communities

Context

The cumulative impact of broad scale environmental change includes altered land-cover and fragmentation. Both altered land-cover and fragmentation have a negative effect on species diversity, but the scale they act on may differ because land-cover alters environmental characteristics, whereas fragmentation alters movement among sites.

Objectives

We evaluated the scale specific effects of land-cover, fragmentation, and habitat size on alpha and beta diversity (total, turnover, and nestedness).

Methods

Stream fish communities were sampled across five urbanizing watersheds. Generalized mixed linear models were used to test how diversity (alpha and beta) is affected by land-cover, connectivity, and habitat size. Indices of land-cover were calculated from correspondence analyses on land-cover data, fragmentation was estimated with the dendritic connectivity index, and habitat size was calculated as the length of the stream segment (alpha diversity) or the length of the stream network (beta diversity).

Results

Alpha diversity was most strongly related to land-cover variables associated with urban development and agriculture (negative relationship with urbanization). Whereas, beta diversity was most strongly influenced by habitat size (positive relationship) and fragmentation (positive relationship). Turnover was positively correlated with fragmentation and habitat size, whereas species loss was negatively correlated with habitat size.

Conclusions

Land-cover has a larger effect on alpha diversity because it alters the environmental conditions at a site, whereas fragmentation has a larger effect on beta diversity because it affects the movement of individuals among sites. Assessing the cumulative impact of environmental change requires a multiscale approach that simultaneously considers alpha and beta diversity.

     

Control of ecosystem state in a shallow,brackish lake: implications for the conservation of stonewort communities

• 1. The alternative stable states hypothesis for the behaviour of shallow lake communities requires switches to transform clear-water macrophyte-dominated communities to turbid algal-dominated ones. Such switches have rarely been demonstrated experimentally. This study shows the role of rising salinity as such a switch while contributing a solution to the conservation problems of an important nature reserve.
• 2. Hickling Broad changed from a clear-water, charophyte-dominated lake to a turbid, phytoplankton-dominated lake in the early 1970s, probably owing to guanotrophication by gulls and to increased salinity from more intensive pumping of the agricultural land that separates its main inflow from the nearby North Sea. Following a decline in nutrient loading as the gull flock moved away, the plants began to return during the 1980s and 1990s. In 1998/99, the water cleared and charophytes, including some very rare species, were abundant.
• 3. This was welcome to conservation bodies, but the vigorous growth precluded competitive sailing and there were conflicts with the local sailing club. The plants, however, began an irregular decline in 2000, though nutrient loadings and other conventional chemical drivers have remained steady.
• 4. Our hypothesis was that the unstable nature of the plant community was linked to high salinity, and that if salinity were lowered there would be vigorous and reliable growth, enabling annual cutting of plants to allow sailing races. In an experiment using mesocosms, salinities straddling the current values in the Broad led to declines in plant biomass, macrophyte species richness and macrophyte Shannon–Weaver diversity through increased release of phosphorus from the sediments, increased algal turbidity and reduction of zooplankton grazer activity.
• 5. Stabilization of the plant community of Hickling Broad would be achieved by a reduction of present salinities by about 20%. This would be possible by use of existing Environmentally Sensitive Area (High Level Environmental Stewardship) arrangements or diversion of some pumped drainage water to the sea. There remain some uncertainties about the future of the area because of rising sea levels.

Copyright © 2007 John Wiley & Sons, Ltd.