bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calcium inhibition halts developmental programmed cell death in the lace plant, Aponogeton madagascariensis?
Authors: Elliott Anna , Gunawardena Arunika H.L.A.N. 
Published: March 2010

This study examined the effect of the calcium channel blocker ruthenium red (RR) on developmental programmed cell death (PCD) and perforation formation in leaves of the aquatic lace plant ( Aponogeton madagascariensis (Mirbel) H. Bruggen). Plant immersion experiments were conducted using various concentrations (0, 10, 20, 30, and 40 µmol·L–1) of RR applied to whole plants over a 3 to 4 week period. The ratio of number of leaf perforations per centimetre of leaf length along with leaf length were used to assess treatment effect. While the ratio of number of perforations per centimetre of leaf length was significantly reduced with RR treatment, leaf length was not, overall, significantly affected by RR. Therefore, it was concluded that RR was able to inhibit calcium movement and halt PCD, thus reducing perforation formation without having detrimental effects on leaf growth. The present research provides indirect evidence of the possible role of calcium in developmental PCD in vivo during leaf morphogenesis in the lace plant. Furthermore, it suggests the usefulness of the lace plant as a model system for pharmacological studies involving developmental PCD.
Introduced deer and the pollination and reproduction of an animal-pollinated herb
Authors: Vázquez Diego P. , Gresser Julie , Martin Jean-Louis 
Published: March 2010

We evaluated the hypothesis that the modified population density of Aquilegia formosa Fisch. ex DC. (Ranunculaceae) resulting from the introduction of Sitka black-tailed deer ( Odocoileus hemionus sitkensis ) in the Haida Gwaii archipelago affects the pollination and reproductive performance of this herbaceous species. We compared the population density, pollination, and reproductive success of A. formosa among three small islands colonized by deer and three deer-free islands. Islands with deer had a substantially lower absolute density and a greater relative density of A. formosa than deer-free islands. The presence of deer was associated with higher pollen deposition, which probably resulted from the greater relative density of A. formosa on islands with deer. However, the presence of deer had no significant effect on individual reproductive success. The latter result is likely a consequence of the lack of pollen limitation in this species, as well as of the conflicting relationship between the absolute and relative densities of A. formosa and the presence of deer.
Riparian alder ecosystems as epiphytic lichen refugia in sub-boreal spruce forests of British Columbia
Authors: Doering Matthew , Coxson Darwyn 
Published: March 2010

Alder-dominated riparian forests represent only a small proportion of the landscape in central-interior British Columbia. However, they possess a suite of attributes that may allow them to function as refugia for canopy macrolichens. These include their deciduous habitat, their location in moist nutrient receiving sites, and their distribution as narrow corridors that cross broad regional landscapes. We have examined their potential role as lichen refugia by assessing canopy macrolichen communities in 75 riparian alder forests across a 200 km longitudinal gradient in central-interior British Columbia. Study sites were stratified equally between three climate subzones of the Sub-Boreal Spruce biogeoclimatic zone. Forty-nine macrolichen taxa were observed, including the old-growth indicator cyanolichen species Lobaria scrobiculata (Scop.) DC., L. retigera (Bory) Trevisan, Nephroma isidiosum (Nyl.) Gyelnik, and Sticta limbata (Sm.) Ach. Canonical correspondence analysis identified mean annual temperature, mean annual precipitation, age of adjacent conifer forest, and abundance of large stems (dbh >10 cm) as significant explanatory variables. Regional precipitation gradients explained the exclusion of many lichen species from both the most westerly and most easterly riparian forests, with drier summer conditions and heavy winter snowpack, respectively, being major limiting factors. Lichens preferentially occupied large leaning stems, which may provide greater precipitation interception and continuity of substrate, when compared with smaller upright alder stems. We conclude that alder-dominated riparian forests represent a major refugium for old-growth dependent lichens in British Columbia’s sub-boreal spruce landscapes and as such may provide valuable dispersal corridors between remnant old-growth coniferous forest patches.
Kennetcook thrust system: late Paleozoic transpression near the southern margin of the Maritimes Basin, Nova Scotia
Authors: Waldron John W.F. , Roselli Carlos G. , Utting John , Johnston Stanley K. 
Published: March 2010

A major zone of deformation affects Early Carboniferous rocks in the southern part of the Maritimes Basin of Nova Scotia, close to the boundary between the Avalon and Meguma terranes of the Appalachians. Field relationships at Cheverie indicate thrusting of Tournaisian Horton Group clastics over Viséan Windsor Group carbonates, evaporites, and clastics, a relationship confirmed by the Cheverie #01 well. Mapped relationships to the south indicate that a system of thrusts, here termed the Kennetcook thrust system, climbs upsection to the southeast, becoming a décollement within Windsor Group evaporites. Industry seismic profiles clearly show deformed Windsor Group, and include fold and fault structures indicative of evaporite flow and solution collapse. Below the Windsor Group, half-grabens filled with Horton Group are clearly imaged; offsets at graben-related faults show that these structures were inverted during later shortening. Above the Windsor Group, less deformed rocks of the Pennsylvanian Scotch Village Formation (Cumberland Group) fill minibasins created by the withdrawal or solution of deformed Windsor evaporites. The timing of thrusting is constrained by these relationships and by crosscutting intrusions to a narrow interval around the Mississippian–Pennsylvanian boundary prior to ∼315 Ma. Deformation was probably related to dextral transpression along the former Avalon–Meguma boundary. Depending on how shortening was transmitted to the southeast, up to 1500 km2 of southern mainland Nova Scotia may be underlain by tectonically transported rocks.
Insights into the metamorphic evolution of the Belt–Purcell basin; evidence from Lu–Hf garnet geochronology
Authors: Zirakparvar N. A. , Vervoort J. D. , McClelland W. , Lewis R. S. 
Published: March 2010

We have determined Lu–Hf garnet ages from spatially separated garnet bearing localities in northern Idaho. The Lu–Hf ages are diverse and reflect a progression of Mesoproterozoic metamorphic events. The oldest Lu–Hf garnet age determined in this study is 1463 ± 24 Ma for garnet within a kyanite schist exposed in the core-zone of the Boehls Butte metamorphic complex. A garnet schist from the Priest River complex yields a well-defined age of 1379 ± 8 Ma. A garnet–staurolite schist, a garnet–mica schist, and a gem-grade Idaho star garnet sample all from the general vicinity of Clarkia, Idaho, yield ages of 1064 ± 10, 1081 ± 20, and 1078 ± 17 Ma, respectively. A garnet amphibolite, also collected from the Boehls Butte metamorphic complex, yields an age of 1151 ± 41 Ma for garnet porphyroblasts and 137 ± 25 Ma for diffuse overgrowths. The Hf in all of the Proterozoic garnets is extraordinarily radiogenic with εHf values ranging from +1210 to +10546, which attest to both their high Lu/Hf ratios and their great antiquity. All of the samples analyzed in this study are from the rocks of the Mesoproterozoic Belt–Purcell Supergroup or its basement. These data provide evidence of polymetamorphism in northwestern Laurentia during the Mesoproterozoic.
Empirical evaluation of predator-driven diel vertical migration in Lake Superior
Authors: Stockwell Jason D. , Hrabik Thomas R. , Jensen Olaf P. , Yule Daniel L. , Balge Matthew 
Published: March 2010

Recent studies on Lake Superior suggest that diel vertical migration (DVM) of prey (generalized Coregonus spp.) may be influenced by the density of predatory siscowet ( Salvelinus namaycush ). We empirically evaluated this hypothesis using data from acoustic, midwater trawl, and bottom trawl sampling at eight Lake Superior sites during three seasons in 2005 and a subset of sites in 2006. We expected the larger-bodied cisco ( Coregonus artedi ) to exhibit a shallower DVM compared with the smaller-bodied kiyi ( Coregonus kiyi ). Although DVM of kiyi and cisco were consistent with expectations of DVM as a size-dependent, predator-mediated process, we found no relationship between siscowet density and the magnitude of DVM of either coregonid. Cisco appear to have a size refuge from siscowet predation. Kiyi and siscowet co-occur in demersal habitat > 150 m during the day, where visual predation is unlikely, suggesting predator avoidance is not a factor in the daytime distribution of kiyi. Seasonal patterns of kiyi DVM were consistent with reported DVM of their primary prey Mysis relicta . Our results suggest that consideration of nonvisual foraging, rather than light-based foraging theory (i.e., the antipredation window), is necessary to understand the processes driving DVM in deepwater systems.
Forecasting the distribution of the invasive round goby (Neogobius melanostomus) in Wisconsin tributaries to Lake Michigan
Authors: Kornis Matthew S. , Vander Zanden M. Jake 
Published: March 2010

The Laurentian Great Lakes host more than 180 non-native species, including several that have resulted in major economic and ecological effects. This list includes the round goby ( Neogobius melanostomus ), an aggressive, benthic Ponto-Caspian fish that has established large populations in coastal Great Lakes habitats. Here, we document the inland dispersal of round gobies into Wisconsin tributaries of Lake Michigan. Round gobies were detected in 26 of 73 streams (36%) and found >10 km upstream of Lake Michigan in nine watersheds. Round goby presence–absence was modeled using landscape-scale data from these invaded streams. We forecasted the future spread of round goby within Wisconsin’s Lake Michigan basin using our best model (80% accuracy), which included watershed area, stream gradient, and watershed slope as predictors. Round gobies were predicted to invade 1369 km of stream habitat up to the first stream barrier, and 8878 km of stream was identified as suitable looking beyond barriers at the broader Lake Michigan watershed (Wisconsin only). Our results depict the Great Lakes as a springboard for invasive species to disperse into inland ecosystems and, because round gobies are not usually reported in small streams in their native range, emphasize the utility of data from invaded regions when forecasting invasive species distributions.
Conductivity percolation of carbon nanotubes (CNT) in polystyrene (PS) latex film
Authors: Uğur Ş. , Yargi Ö. , Pekcan Ö. 
Published: March 2010

In this study, the effect of multiwalled carbon nanotubes (MWNT) on film formation behaviour and electrical conductivity properties of polystrene (PS) latex film was investigated by using the photon transmission technique and electrical conductivity measurements. Films were prepared by mixing PS latex with different amounts of MWNTs, varying in the range between 0 and 20 wt%. After drying, MWNT content films were separately annealed above the glass transition temperature (Tg) of PS, ranging from 100 to 270 °C, for 10 min. To monitor film formation behavior of PS–MWNT composites, transmitted light intensity, Itr, was measured after each annealing step. The surface conductivity of annealed films at 170 °C was measured and found to increase dramatically above a certain fraction of MWNT (4 wt%) following the percolation theory. This fraction was defined as the percolation threshold of conductivity, Rc. The conductivity scales with the mass fraction of MWNT as a power law with exponent 2.27, which is extremely close to the value of 2.0 predicted by percolation theory. In addition, the increase in Itr during annealing was explained by void closure and interdiffusion processes. Film formation stages were modeled and the corresponding activation energies were measured.
Can structural and functional characteristics be used to identify riparian zone width in southern Appalachian headwater catchments?
Authors: Clinton Barton D. , Vose James M. , Knoepp Jennifer D. , Elliott Katherine J. , Reynolds Barbara C. , Zarnoch Stanley J. 
Published: March 2010

We characterized structural and functional attributes along hillslope gradients in headwater catchments. We endeavored to identify parameters that described significant transitions along the hillslope. On each of four catchments, we installed eight 50 m transects perpendicular to the stream. Structural attributes included woody and herbaceous vegetation; woody debris and forest floor mass, nitrogen (N) and carbon (C); total soil C and N; litterfall amount and quality by species; and microclimatic conditions. Functional attributes included litter decomposition, soil microarthropods, soil CO2evolution, soil solution chemistry, and soil extractable N. Forest floor mass, N and C, and soil depth increased with distance from the stream and transitioned between 10 and 20 m. In contrast, litterfall N rate (kilograms of nitrogen per hectare per day), downed woody debris, soil A-horizon C and N, and soil solution NO3concentration all decreased with distance, and exhibited significant transitions. Certain overstory species were more abundant in the uplands than near the stream. Herbaceous diversity and richness were similar across the hillslope, but species distributions varied in response to hillslope moisture content. Taken together, these results suggest that at 10–20 m from the stream, transitions occur that separate riparian from upland conditions and may provide valuable insight into riparian zone definition.
Regeneration dynamics after patch cutting and scarification in yellow birch – conifer stands
Authors: Prévost Marcel , Raymond Patricia , Lussier Jean-Martin 
Published: March 2010

We present the 6 year effects of different cutting patterns (patch-selection cutting with 20, 30, and 40 m diameter gaps, 1 ha patch clear-cut, and uncut control) and spot scarification, on seedbed coverage and regeneration dynamics in yellow birch ( Betula alleghaniensis Britton) – conifer stands in eastern Quebec, Canada. After 3 years, yellow birch had established better in cutting patterns with gaps than in the patch clear-cut and in the control, while its density was 7 times higher in scarified than in nonscarified subplots. After 6 years, scarified openings and the borders of openings had 3–5 times more seedlings >30 cm in height than nonscarified openings and the understory between the gaps. The loss of advance growth in openings was the main result for conifer species, although recruitment of new balsam fir ( Abies balsamea (L.) Mill.) seedlings was accelerated by scarification. Despite the abundance of red spruce ( Picea rubens Sarg.) seed-trees on the site, our treatment combinations failed to promote its natural regeneration. Varying gap size did not change the total density of competing vegetation but modified the composition of this shrub layer. Our 6 year results suggest that maintaining conifer species, and the mixed composition of the stands, is uncertain over the long term.
Fine root decomposition in two subalpine forests during the freeze–thaw season
Authors: Wu Fuzhong , Yang Wanqin , Zhang Jian , Deng Renju 
Published: March 2010

Little is known about fine root decomposition during the freeze–thaw season. To characterize fine root decomposition during this time (from October 2006 to April 2007), a field experiment was conducted to examine the decomposition of fine roots (diameters of 0–1 and 1–2 mm) of Minjiang fir ( Abies faxoniana Rehd. & E.H. Wilson) and Asian white birch ( Betula platyphylla Sukaczev) using buried litterbags in their respective habitats in western Sichuan, China. Over one freeze–thaw season, 14%–20% of mass was lost and 12%–31% of C, 6%–36% of N, 15%–25% of P, and 37%–43% of K were released. These losses accounted for about 40%–55% of mass lost and 23%–54% of C, 23%–89% of N, 25%–42% of P, and 48%–58% of K released within the first year of fine root decomposition. The amount of mass loss and bioelements release during the freeze–thaw season correlated closely with initial substrate quality and bioelement traits. Compared with birch fine root, fir fine root decomposition could be influenced more by decomposition processes during the freeze–thaw season. Results suggest that fine root decomposition during the freeze–thaw season can strongly contribute to ecosystem C and nutrient cycling.
Influence of moisture and freeze–thaw on leaf microbial community dynamics
Authors: Corrigan C. , Oelbermann M. 
Published: March 2010

In forest ecosystems, litterfall that collects in trapping devices, to quantify organic matter and nutrient inputs, is exposed to periods of wetting, drying, freezing, and thawing. These fluctuating environmental conditions may influence the microbial community structure inhabiting the leaves and may result in the loss of mobile nutrients, leading to an underestimation of actual organic matter and nutrient inputs. The objectives of this study were to evaluate the influence of (i) different quantities of moisture (LOW = 30 mm, MED = 60 mm, HI = 100 mm) and (ii) freeze–thaw (FT) on leaf (sugar maple ( Acer saccharum Marsh.), American basswood ( Tilia americana L.), and American beech ( Fagus grandifolia Ehrh.)) microbial activity and community structure. There was a significantly greater (p < 0.05) CO2production rate in LOW and FT treatments for sugar maple and beech, and in HI and FT treatments for basswood. A similar trend occurred for leaf nitrogen concentration but not for carbon (C). Utilization of C substrates was up to 10% greater in the FT treatments. Principal components analysis on the activity of C source utilization showed a distinct clustering between leaf species and between treatments following a pattern similar to that of microbial respiration. Results from this study suggested that the collection of litter should take place more frequently during seasons when frost is imminent.
Functional Neuroimaging Can Support Causal Claims about Brain Function
Authors: Weber Matthew J. , Thompson-Schill Sharon L. 
Published: March 2010

Abstract
Cognitive neuroscientists habitually deny that functional neuroimaging can furnish causal information about the relationship between brain events and behavior. However, imaging studies do provide causal information about those relationships—although not causal certainty. Although popular portrayals of functional neuroimaging tend to attribute too much inferential power to the technique, we should restrain ourselves from ascribing it too little.
Honoring the Form: Zen Moves in Charles Johnson’s Oxherding Tale
Authors: Collins Richard 
Published: March 2010

AbstractIn Being and Race Charles Johnson compares a writer working with traditional forms to a martial artist who “honors the form” of his predecessors. In his 1982 novel Oxherding Tale Johnson honors the form of a number of traditional fictional genres, including the slave narrative, the picaresque novel, the philosophical novel of ideas, and Zen texts such as koans, sutras, and the twelfth-century graphic narrative, the “Oxherding Pictures.” Calling his novel a “slave narrative that serves as the vehicle for exploring Eastern philosophy,” Johnson alludes to Hindu, Taoist and Buddhist texts, as well as to Western literary and philosophical works, to dissolve the dualistic thinking at the heart of what he calls “the samsara of racial politics.” To be free of the illusory nature of “ontological dualism,” however, one must journey through stages of increasing awareness, admirably depicted in the ten illustrations of the “Oxherding Pictures.” From seeking a self (ox) that one thinks one has lost, to glimpsing the self that is first elusive and finally illusory, the seeker comes to realize that all identities are constructed and therefore temporary, including such notions as “race” and “self.” Like some biracial Everyman, Johnson’s narrator may not complete the journey by the end of the novel but he discovers much about the insubstantiality and inter-connectedness of himself in the world along the way.
Morphological, morphometrical and molecular characterisation of Filenchus fungivorus n. sp., a fungivorous nematode from Japan in a most likely polyphyletic genus (Nematoda: Tylenchina)
Authors: Bert Wim , Okada Hiroaki , Tavernier Ines , Borgonie Gaetan , Houthoofd Wouter 
Published: March 2010

Abstract
Filenchus fungivorus n. sp., isolated from autumn bellflower (Gentiana
scrabra Bunge) in Japan and maintained on a fungus culture, is described
based on LM, SEM and molecular data. The new species is characterised by
combination of the following features: two lateral lines, short body
(284-331 μm), short stylet (7.0-8.7 μm), amphid aperture associated with
characteristic depression, short ovary, undifferentiated spermatheca,
post-vulval sac shorter than corresponding body diam. and short (59-80 μm)
non-filiform, almost straight tail and absence of males. According to a
principal component analysis, a small tail/vulva-anus (1.3-1.8) and V′ ratio
have the highest morphometrical power to separate F. fungivorus n. sp. from
the remaining analysed Filenchus spp. (with the exception of F. misellus).
Molecular analyses based on SSU rDNA placed F. fungivorus n. sp. within a
clade that contained Filenchus sp. (heathland, Belgium), F. (Ottolenchus)
discrepans, Malenchus andrassyi and F. misellus. However, the position of
this clade could not be resolved within the Tylenchomorpha. Although the
phylogenetic analyses, confirmed by Shimodaira-Hasegawa tests, significantly
rejected the monophyly of Filenchus (P < 0.001), F. fungivorus n. sp. is
placed within Filenchus in anticipation of a review of the Tylenchidae.
Morphological and molecular characterisation of Hemicycliophora lutosa Loof & Heyns, 1969 and H. typica de Man, 1921 from South Africa (Nematoda: Hemicycliophoridae)
Authors: den Berg Esther van , Subbotin Sergei A. , Tiedt Louwrens R. 
Published: March 2010

AbstractTwo Hemicycliophora species, H. lutosa and H. typica, found in samples from fallow soil and sugarcane soil in South Africa, were studied morphologically and, for the first time, molecularly. Diagnostic PCR-IT-rRNA-RFLP profiles generated by five restriction enzymes are provided. Study of phylogenetic relationships using D2-D3 expansion segment of 28S rRNA gene sequences revealed that H. lutosa was related to H. poranga. Hemicycliophora lutosa and H. poranga are compared morphologically. SEM photographs are given for H. typica and for H. lutosa for the first time. The male of H. typica represents a first report for South Africa.