bluuebunny/crossref_metadata_2025_split huggingface dataset:
AN OVERVIEW OF FACTORS THAT INFLUENCE THE DEVELOPMENT OF CANADIAN PEATLANDS
Authors: Vitt Dale H. 
Published: April 2011

AbstractCanadian peatlands can be classified into ombrotrophic bogs and minerotrophic fens, the latter subdivided into poor, moderate-rich, and extreme-rich fens, each with distinctive indicator species, acidity, alkalinity, and base cation content. If hydrology is considered the most important factor in peatland classification then the primary division must be between ombrotrophic bogs and minerotrophic fens; however both chemical and vegetational differences strongly indicate that the primary division of peatlands should be between acidic, Sphagnum-dominated bogs and poor fens on the one hand, and alkaline, brown-moss-dominated rich fens on the other. Although some metals such as sulphur and aluminum also vary along this gradient, nutrient contents of the surface waters do not. Bogs and fens are oligotrophic to mesotrophic wetlands that should be distinguished from eutrophic, non-peat-forming wetlands such as marshes and swamps by the presence in the former of a well-developed ground layer of bryophytes associated with relatively little seasonal water level fluctuation. Oligotrophy is probably maintained in bogs and poor fens by reduced water flow, whereas rich fens maintain mesotrophy by having larger water through-puts; however this is not well documented. Sphagnum appears to have real ecological significance, both in the initial stages of acidification and in controlling surface water temperature. Seasonal variation in surface water chemistry in all peatland types is relatively small, however precipitation events leading to changes in water levels do affect some chemical components. Although both autogenic and allogenic factors affect peatland development, initiation of peat formation and early development of peatlands during the Early and Mid Holocene were considerably influenced by regional climatic change. Later developmental patterns during the late Holocene and those seen at the present time appear to be more influenced by autogenic factors.
LABORATORY AND FIELD EVALUATIONS OF BEAUVERIA BASSIANA (BALSAMO) VUILLEMIN AGAINST GRASSHOPPERS AND LOCUSTS IN AFRICA
Authors: Delgado F.X. , Lobo-Lima M.L. , Bradley C. , Britton J.H. , Henry J.E. , Swearingen W. 
Published: April 2011

AbstractTwo isolates of the fungus Beauveria bassiana (Balsamo) Vuillemin, GHA and BF, were evaluated in Cape Verde in 1991 and 1992 for infectivity to the Senegalese grasshopper, Oedaleus senegalensis (Krauss), and the migratory locust, Locusta migratoria migratorioides (Reiche and Fairmaire). Evaluations included laboratory bioassays and small-scale field trials. Laboratory bioassays evaluated five different formulations. Four of the formulations tested showed strong dose–response patterns and significantly higher mortality than the untreated control or carriers minus spores. All four formulations achieved high mortality levels when applied at economically feasible dose rates. The GHA and BF isolates, formulated in an oil carrier with an emulsifier, were equally infectious to migratory locust nymphs. Six different formulations of GHA were evaluated in field trials. Field trials evaluated both direct effects (treatment of field plots infested with O. senegalensis) and indirect effects (treatment of plots without grasshoppers, after which grasshoppers were introduced). In both cases, all six formulations showed good biocontrol potential. Grasshoppers exposed to treated plots up to 72 h after application exhibited comparatively high mortality levels, indicating that large numbers of spores remained viable in the field for at least 3 days. This was confirmed by analysis of the viability of conidia from vegetation samples obtained in the field following treatment. In open-plot, small-scale field trials, two different formulations (oil and clay-based) of GHA resulted in high rates of infection and approximately 45% reductions in grasshopper densities in the treated plots 7 days after application, even though density-reduction results were "diluted" by grasshopper migration into and out of the test plots. Results of the Cape Verde evaluations demonstrate that biopesticides developed from B. bassiana represent a promising alternative to chemical pesticides for grasshopper and locust control.
CHARACTERIZATION AND VIRULENCE OF A BRAZILIAN ISOLATE OF METARHIZIUM FLAVOVIRIDE GAMS AND ROZSYPAL (HYPHOMYCETES)
Authors: Magalhães B.P. , Faria M. , Tigano M.S. , Sobral B.W.S. 
Published: April 2011

AbstractA new isolate of Metarhizium flavoviride Gams and Rozsypal (Hyphomycetes) (CG 423) found in Northeast Brazil infecting Schistocerca pallens (Thunberg) was identified using arbitrarily primed PCR. Cluster analysis of DNA markers revealed a high level of homogeneity (>83% similarity) among the Brazilian (CG 423) and two other M. flavoviride isolates from Nigeria (CG 366 = IMI 330189) and Australia (CG 291). However, M. flavoviride isolates were very distinct when compared with two isolates of Metarhizium anisopliae (Metschnikoff) Sorokin (6.4% similarity). Bioassays showed that strain CG 423 is as virulent as other isolates of M. flavoviride (CG 291, CG 366), M. anisopliae (CG 087), and Beauveria bassiana (Balsamo) Vuillemin (CG 425) against the grasshopper Rhammatocerus schistocercoides (Rehn) (Orthoptera: Acrididae), an important pest in Central Brazil. However, the Brazilian isolate of M. flavoviride (CG 423) is more virulent than the Brazilian isolate of B. bassiana (CG 250). Because conidia used in bioassays were formulated in soybean oil containing 5% kerosene, the effect of the kerosene present in the oil formulation was tested. Kerosene (0–10%) did not affect the virulence (P > 0.3) of M. flavoviride against R. schistocercoides. The native isolate of M. flavoviride (CG 423) is now being developed as a mycoinsecticide against grasshoppers in Brazil.
Larvae of the North American Tortricinae (Lepidoptera: Tortricidae)
Authors: MacKay Margaret Rae 
Published: April 2011

AbstractThis work is a continuation of that already published on the larvae of the Olethreutidae (now considered to be a subfamily, the Olethreutinae), and is to be used in association with the latter, since no larval characters as yet known separate the two subfamilies. Over 100 species of the North American Tortricinae are discussed, the late-instar larvae of 97 of these are described, and morphological characters of most of them illustrated. Many of them are well-known economic pests such as the spruce and pine budworms, the black-headed budworm, the omnivorous leaf tier, etc. Keys to tribes, genera, species groups and species are provided. The inadequacies of a taxonomic classification based solely upon adult characters are also demonstrated in an examination of the larvae of the genus Archips as presently established.
AQUATIC AND SEMIAQUATIC HETEROPTERA OF ALBERTA, SASKATCHEWAN, AND MANITOBA (HEMIPTERA)
Authors: Brooks Arthur R. , Kelton Leonard A. 
Published: April 2011

AbstractNinety-five species of aquatic and semiaquatic Heteroptera are recorded from the Prairie Provinces of Canada, representing the following families: Belostomatidae 3, Corixidae 41, Gelastocoridae 1, Gerridae 8, Hebridae 2, Hydrometridae 1, Mesoveliidae 1, Nepidae 2, Notonectidae 6, Pleidae 1, Saldidae 26, and Veliidae 3. Also included are data on distribution, habits, and biological information. Keys to families, genera, and species are given, with 138 illustrations.
Antixenosis and antibiosis resistance toCeutorhynchus obstrictusin novel germplasm derived fromSinapis albaxBrassica napus
Authors: Tansey James A. , Dosdall Lloyd M. , Keddie Andrew , Fletcher Ron S. , Kott Laima S. 
Published: April 2011

AbstractIntrogression of cabbage seedpod weevil,Ceutorhynchus obstrictus(Marsham) (Coleoptera: Curculionidae), resistance fromSinapis albaL. to susceptibleBrassica napusL. (Brassicaceae) has produced genetic lines resistant to the weevil in replicated field trials. In the current study, weevil feeding and oviposition onS. albaand on resistant novel lines developed by crossingS. alba×B. napuswere less frequent than on susceptible germplasm.Development times were greater and biomass was less when larvae were reared on resistant lines orS. alba. Oocyte development was faster in post-diapause springtime adult female weevils caged on susceptible plants than in those on a resistant line,S. alba, or an early-season food host,Thlaspi arvenseL (Brassicaceae). Our results suggest that antixenosis resistance and antibiosis resistance are expressed by resistant lines. These results and previous chemical analyses of these lines also suggest that resistance is potentially influenced by attractive and (or) feeding-stimulant effects of 2-phenylethyl glucosinolate and antifeedant or toxic effects of 1-methoxy-3-indolylmethyl glucosinolate.
Camptopeltes, a new Neotropical genus of oscinelline Chloropidae (Diptera)
Authors: Mlynarek Julia J. , Wheeler Terry A. 
Published: April 2011

AbstractCamptopeltesn.gen. is described for three new species: Camptopeltes atratumn. sp. (type species of the genus; type locality Cartago, Costa Rica); Camptopeltes citrinumn. sp. (type locality Yacambo, Venezuela); and Camptopeltes nubilatumn. sp. (type locality Aragua, Venezuela). Camptopeltes is distinguished from other oscinelline genera on the combination of a strongly convex scutum, a trapezoidal scutellum that is deflected dorsally relative to the scutum, a reduced flexure in wing vein CuA1, reduced cephalic bristling, reniform third antennal segment, and thin arista. Although its relationship to the rest of the Oscinellinae is unresolved, it may be closely related to the tribe Elachipterini.
Influence of elevation and avian or mammalian hosts on attraction of Culex pipiens (Diptera: Culicidae) in southern Ontario
Authors: Russell Curtis , Hunter Fiona F. 
Published: April 2011

AbstractWe studied Culex pipiens L. in the Niagara Region of Ontario, Canada, to establish whether or not these mosquitoes are attracted to hosts other than birds at different elevations or as the season progresses. Guinea-pigs and chickens were used as representative mammalian and avian hosts, respectively. Bait animals were placed next to modified CDC miniature light traps (no light and no CO2) hung 1.5 or 5 m above ground in a Niagara woodlot. The season was divided into three 6-week periods (early, middle, and late). Significantly more C. pipiens were captured at the 5 m than at the 1.5 m elevation. In general, chicken-baited traps were preferred over control and guinea-pig-baited traps, with one important exception: there was no significant difference among traps during the late period at 1.5 m elevation. The potential role of C. pipiens as a bridging vector of West Nile virus to humans is discussed.
Biology and development ofAcrolepiopsis assectella(Lepidoptera: Acrolepiidae) in eastern Ontario
Authors: Mason P. G. , Appleby M. , Juneja S. , Allen J. , Landry J.-F. 
Published: April 2011

AbstractLeek moth,Acrolepiopsis assectella, recently became established in the Ottawa Valley, where it significantly damages garlic, leek, and onion (AlliumL., Liliaceae) crops. At a threshold of 7 °C, populations in eastern Ontario require 444.6 day-degrees to develop from egg to adult. Pheromone-trap data identify spring, early-summer, and late-summer flight periods of overwintered 1st- and 2nd-generation adults, respectively. Depending on ambient temperatures, the life cycle takes 3–6 weeks in the field, with three generations possible. Management strategies such as application of reduced-risk foliar insecticides and use of row covers require precise timing to target appropriate life-cycle stages. Implementation windows can be determined by incorporating pheromone-trap data and ambient air temperature into a life-cycle development model. A proposed integrated pest management program will involve the use of pesticides, mechanical barriers, and classical biological control.
Distinctive TLR7 Signaling, Type I IFN Production, and Attenuated Innate and Adaptive Immune Responses to Yellow Fever Virus in a Primate Reservoir Host
Authors: Mandl Judith N. , Akondy Rama , Lawson Benton , Kozyr Natalia , Staprans Silvija I. , Ahmed Rafi , Feinberg Mark B. 
Published: April 2011

Abstract
Why cross-species transmissions of zoonotic viral infections to humans are frequently associated with severe disease when viruses responsible for many zoonotic diseases appear to cause only benign infections in their reservoir hosts is unclear. Sooty mangabeys (SMs), a reservoir host for SIV, do not develop disease following SIV infection, unlike nonnatural HIV-infected human or SIV-infected rhesus macaque (RM) hosts. SIV infections of SMs are characterized by an absence of chronic immune activation, in association with significantly reduced IFN-α production by plasmacytoid dendritic cells (pDCs) following exposure to SIV or other defined TLR7 or TLR9 ligands. In this study, we demonstrate that SM pDCs produce significantly less IFN-α following ex vivo exposure to the live attenuated yellow fever virus 17D strain vaccine, a virus that we show is also recognized by TLR7, than do RM or human pDCs. Furthermore, in contrast to RMs, SMs mount limited activation of innate immune responses and adaptive T cell proliferative responses, along with only transient antiviral Ab responses, following infection with yellow fever vaccine 17D strain. However, SMs do raise significant and durable cellular and humoral immune responses comparable to those seen in RMs when infected with modified vaccinia Ankara, a virus whose immunogenicity does not require TLR7/9 recognition. Hence, differences in the pattern of TLR7 signaling and type I IFN production by pDCs between primate species play an important role in determining their ability to mount and maintain innate and adaptive immune responses to specific viruses, and they may also contribute to determining whether disease follows infection.
Alternatives for enrichment of eggs and chicken meat with omega-3 fatty acids
Authors: González-Esquerra R. , Leeson S. 
Published: April 2011

Interest on the enrichment of eggs and poultry meat with omega-3 fatty acids (n-3 FA) has increased given their important role in human metabolism. The inclusion of n-3 FA into eggs and poultry meat is achieved by feeding ingredients such as flaxseed, fish oil, fish meal, marine algae and canola to birds. However, problems in various production parameters and sensory quality of eggs and meat may arise. The former possibly caused by antinutritional and physiological effects and the latter influenced by the interaction of volatile substances. Possible increases in formulation costs also deserve attention. Strategies to ameliorate these undesirable effects include limiting the inclusion levels of n-3 FA sources, time of feeding, mixing different n-3 FA sources in commercial rations, and including high levels of vitamin E along with high-quality ingredients. A mild heat treatment may eliminate some of the drawbacks of feeding flaxseed to birds. Key words: Omega-3, flaxseed, flax, menhaden oil, eggs, chicken meat
Sulphur fertilizer and tillage effects on early season sulphur availability and N:S ratio in canola in western Canada
Authors: Grant C. A. , Johnston A. M. , Clayton G. W. 
Published: April 2011

Field studies in Manitoba, Saskatchewan and Alberta over 3 yr evaluated immediate and residual effects of source, timing and placement of S fertilizers on sulphate-S supply to canola (Brassica napus L.). The treatments were compared under conventional tillage (CT) and in the establishment years of a reduced (RT) system. Sulphate-S in the soil was measured for two weeks after seeding, using PRSTM-probes. Sulphur concentration and N:S ratio were measured in canola tissue at flowering. Tillage system had little effect on available sulphate, tissue S concentration, N:S ratio or response to S fertilization. Ammonium sulphate (AS) generally increased tissue S concentration and reduced N:S ratio with all placements, and the effects of surface-applied ammonium thiosulphate (ATS) were similar to the effects of AS. Tiger 90, a bentonite-elemental S formulation, generally produced lower S concentrations in canola tissue at flowering than did AS, and levels were similar with elemental S and Tiger 90. Both tissue S concentration and N:S ratio were good indicators of S sufficiency for canola. Sulphate carryover from AS increased tissue S concentration and decreased N:S ratio in the year following application. In contrast, increases in tissue S concentration and decreases in N:S ratio were lower with Tiger 90 than AS. The oxidation of the residual elemental S in Tiger 90 could not be relied upon to increase tissue S concentration above deficiency levels in the year following application where soil sulphate levels were low. Key words: Elemental S, bentonite S, zero tillage, N:S ratio, PRS-probes
The indicator of risk of water contamination by nitrate-nitrogen
Authors: De Jong R. , Yang J Y , Drury C F , Huffman E C , Kirkwood V. , Yang X M 
Published: April 2011

Drriven by changes in agricultural production practices, nitrogen (N) inputs have increased steadily on Canadian farms. An agro-environmental indicator was developed to monitor potential water pollution by N: indicator risk of water contamination by nitrate-nitrogen (IROWC-N). The indicator links the residual soil nitrogen (RSN) indicator to climate and soil conditions to assess the likelihood of N moving through the soil and out of the agricultural system. The results are assessed in terms of Nlost via leached water (Nlost) and its concentration in the leached water (Nconc), with the IROWC-N risk classes based on Nlost and Nconc criteria. The estimated amount of Nlost in Canada ranged from 5.1 kg N ha-1 in 1991 to 6.4 kg N ha-1 in 2001. Nconc values remained fairly constant during the 1981 to 1996 census years (ranging from 3.7 to 4.5 mg N L-1), but increased sharply (27%) to 5.7 mg N L-1 in 2001 as compared with 1996. During the 1981 to 2001 period, close to 80% of the Canadian farmland area remained in the very low and low IROWC-N risk classes, but over the years 18% shifted to a higher risk class. In 2001, large areas (> 1 million ha) in the high risk IROWC-N class were found in Manitoba, southern and eastern Ontario and in Quebec. Provincial averages of Nlost over 5 census years (1981, 1986, 1991, 1996 and 2001) varied from less than 5 kg N ha-1 in Alberta and Saskatchewan to more than 20 kg N ha-1 in Ontario, Quebec and the Atlantic provinces. With the exception of Manitoba, provincial Nconc values did not exceed the Canadian drinking water guideline of 10 mg NO3-N L-1. In each of the census years, British Columbia, Alberta and Saskatchewan had more than 70% of the farmland area in the very low and low risk classes for IROWC-N. In Ontario and Quebec, most of the farmland area was either in the low or in the high risk class. More than 50% of the farmland area in New Brunswick, Nova Scotia and Newfoundland was in the very low, low and moderate risk classes, whereas in Manitoba and Prince Edward Island, more than 60% of the farmland was in the moderate and higher level risk classes for IROWC-N. Overall, the 20-yr trend in risk of water contamination by N was worsening. Key words: Water contamination by nitrogen, nitrate, water quality, Soil Landscapes of Canada, Census of Agriculture
Yield and N uptake of barley on two artificially eroded soils in north-central Alberta
Authors: Pradhan R. , Izaurralde R. C. , Nyborg M. , Malhi S. S. 
Published: April 2011

Topsoil depth is an indirect indicator of soil quality and crop productivity. A 2-yr field study was conducted in north-central Alberta with the following objectives: (1) to determine aboveground barley dry matter yield, N uptake, and fertilizer-use efficiency (FUE) in two artificially eroded soils of contrasting properties, and (2) to assess the effectiveness of KNO3 and urea in compensating for lost productivity. Field experiments were conducted on an Orthic Gray Luvisol (Site 1) and on an Eluviated Black Chernozem (Site 2) in 1991 and 1992. The treatments consisted of three depths of topsoil removal (0, 10 and 20 cm) and three N fertilizers (KNO3 and urea at 150 kg N ha−1, and the control). The plots were sown to barley (Hordeum vulgare L.). Yields and N uptake of aboveground barley dry matter decreased with each increment of topsoil removal and were lowest in the 20-cm topsoil removal. Fertilizer N improved yields and N uptake at each depth of erosion. In most of the erosion treatments barley yields and N uptake tended to be greater with KNO3 than with urea. The effectiveness of each N source, however, varied with site. At the 20-cm depth of erosion, KNO3 was more effective than urea. The trend in fertilizer-use efficiency increased with depth of erosion at Site 1 but decreased at Site 2. Key words: Artificial erosion, barley, fertilizer-use efficiency, potassium nitrate, urea
Chemical characterization of dissolved organic matter released by limed and unlimed forest soil horizons
Authors: Erich M. Susan , Trusty Georgette M. 
Published: April 2011

Liming of forest soils, currently practiced in Europe, may be necessary in the future in North America to counteract calcium (Ca) depletion due to whole tree harvesting. With current concerns over increasing carbon dioxide (CO2) levels in the atmosphere, the effects of forest practices such as liming on carbon (C) cycling in forest ecosystems has been receiving increasing attention. This laboratory study investigated the effect of an increase in pH on dissolved organic matter (DOM) in water extracts of organic horizons. Organic horizons were collected from nine forested sites, some predominantly hardwood and some predominantly softwood stand types. The soils were chemically characterized. Water extracts of limed and unlimed treatments of nine organic horizons were analyzed for pH, Al, Fe, Ca, C, and DOM negative charge density. Total luminescence fluorescence spectra were also obtained for each extract. The addition of lime (CaCO3) to organic horizons caused an average of 55% more C to be released than in unamended samples. Liming caused no significant changes in negative charge density of the DOM. Liming decreased organically-complexed aluminum (Al) and increased organically-complexed Ca. There was a negative correlation between Al concentration of extracts and fluorescence intensity. Chemical changes in the DOM released by liming were suggested by decreased fluorescence emission and excitation wavelengths due to liming. Hardwood samples did not respond differently than softwood samples with respect to DOM concentration, functional group concentration, or spectroscopic characteristics. However, there was a suggestion that particular tree species, such as cedar, may have unique effects on C concentrations and DOM chemistry. Key words: Lime, forest soil, dissolved organic matter, fluorescence