bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soluble carbohydrate content of shoots of Arctic wetland plants that are consumed by lesser snow geese
Authors: Jefferies Robert L. , Edwards Kate A. 
Published: October 2008

We recorded seasonal changes in the total amounts of soluble carbohydrates in shoots of salt- and fresh-water coastal plants at La Pérouse Bay, northern Manitoba, to determine whether adult snow geese and their goslings selected forage rich in soluble carbohydrates during the breeding season. The selection of forage plants in spring and summer by adults and goslings was strongly linked to the presence of high amounts of soluble carbohydrates in tissues: on the order of 100 mg·g–1dry mass. When the content fell as a result of shoot development or leaf senescence, the geese switched to alternative sources of forage. The extent to which individual shoots rich in soluble carbohydrates of the primary freshwater forage species are grazed depends on the local density of breeding geese at the study site, which has fallen in the last decade as a result of the earlier destruction of much of the coastal vegetation by foraging geese.
Resistance-related metabolites in wheat against Fusarium graminearum and the virulence factor deoxynivalenol (DON)
Authors: Paranidharan V. , Abu-Nada Y. , Hamzehzarghani H. , Kushalappa A. C. , Mamer O. , Dion Y. , Rioux S. , Comeau A. , Choiniere L. 
Published: October 2008

Inoculation with the virulence factor deoxynivalenol (DON) can induce disease symptoms in wheat ( Triticum aestivum L.) spikelets, even though it is not needed for the initial invasion by Fusarium graminearum Schwabe, thus the mechanism of plant defense against both the pathogen and DON, was investigated. Wheat cultivars that are resistant (‘Sumai3’) or susceptible (‘Roblin’) to fusarium head blight (FHB) were inoculated with F. graminearum, DON, or water. Inoculated spikelets were harvested 48 h after inoculation, the metabolites were extracted in methanol–water and chloroform, then derivatized and analyzed by gas chromatography – mass spectrometry. The metabolite peaks were deconvoluted and identified by manually matching the mass spectra with those in the NIST and GMD libraries. The peaks were aligned, and abundances were measured. A total of 117 metabolites were tentatively identified, including several antimicrobial metabolites and signal molecules or their precursors. Out of these 117 metabolites, 15 and 18 were identified as possible resistance-related (RR) metabolites, following F. graminearum (RRIF) and DON (RRID) inoculations, respectively, with 4 metabolites common to both. Canonical discriminant analysis of marginally significant metabolites (105) identified those with constitutive and induced resistance functions. The metabolites with high canonical loading to the canonical vectors were used to explain these functions. The putative roles of these RR metabolites in plant defense, their metabolic pathways, and their potential application for screening of wheat breeding lines for resistance to FHB are discussed.
Endosporium, a new endoconidial genus allied to the Myriangiales
Authors: Tsuneda A. , Davey M. L. , Hambleton S. , Currah R. S. 
Published: October 2008

A new endoconidial genus, Endosporium gen. nov., is reported from Alberta, Canada. Two species are described: Endosporium populi-tremuloidis Tsuneda sp. nov. (type species) isolated from a heavily colonized bud of Populus tremuloides Michx., and Endosporium aviarium Tsuneda sp. nov. isolated from the skin of Bombycilla garrulus (L.) (Bohemian waxwing) and a twig of Populus balsamifera L. This genus is morphologically similar to Phaeotheca in forming black, slow-growing colonies (conidiomata) containing numerous, conidiogenous, cellular clumps, but different in that (i) colonies possess aerial, determinate hyphae on the surface; (ii) mature colonies eventually collapse to release a mixture of conidiogenous cellular clumps, endoconidia, and blastic conidia in slimy liquid; and (iii) endoconidia are hyaline. Phylogenetic analyses of nuclear rDNA SSU, LSU, and ITS sequences indicate that Endosporium is phylogenetically distant from other endoconidial taxa, including Phaeotheca, and is most closely related to the Myriangiales (Dothideomycetes). Similarities in stroma and conidioma development as well as ecology between the two taxa suggest that Endosporium can be accommodated within this order, making it the first endoconidial and first black meristematic genus reported in the Myriangiales.
Genetic background affects genetically modified ethylene sensing in birch–insect interaction
Authors: Alatalo Ira , Haviola Sanna , Saloniemi Irma 
Published: October 2008

Several studies suggest that ethylene is involved in the responses and resistance of plants against herbivores and pathogens, but the role of ethylene seems to vary depending on the system studied. Here we extend the studies of introduced Arabidopsis thaliana (L.) Heynh. ethylene receptor gene (etr1-1) to a new type of interaction: a woody plant, Betula pendula Roth (silver birch) and its herbivore, Epirrita autumnata (Borkhausen) (autumnal moth). We studied constitutive insect resistance of two wild-type birch genotypes, V and J, which were very different hosts for E. autumnata. On the J background, genetically modified ethylene insensitivity decreased the performance of E. autumnata, measured as leaf damage, larval mass, or pupal mass. However, hardly any changes were detectable in the V background, which is an inferior wild-type genotype for autumnal moth performance, except increased leaf damage caused by E. autumnata in ethylene-insensitive trees. Ethylene insensitivity caused clear side effects on birch phenology and morphology, especially in the J background. In this background, ethylene modification mainly acted via accelerating phenology, but this was hardly detectable in the V genotype. Also, the number of long shoots increased only in the modified J background. Taken together, it seems that the effects of ethylene on several birch traits relevant for E. autumnata and birch morphology depend on the birch genetic background.
Effects of temporal heterogeneity of watering on size of an annual forb, Perilla frutescens (Lamiaceae), depend on soil nutrient levels
Authors: Hagiwara Yousuke , Kachi Naoki , Suzuki Jun-Ichirou 
Published: October 2008

Temporal heterogeneity of watering affects plant growth. When the same total amount of water is supplied, frequent watering leads to greater plant size than infrequent watering. However, the effects of a given watering regime can differ when nutrient levels vary. An experiment was designed to test the hypothesis that the effects of temporal heterogeneity of watering on plant growth also vary as a function of nutrient levels. Perilla frutescens (L.) Britton was grown using different combinations of nutrient levels and watering frequencies, with total water held constant across the treatments. The effects on plant size were analysed after 36 d. Under nutrient-rich conditions, frequent watering resulted in significantly larger plants than infrequent watering. However, under nutrient-poor conditions, no significant difference was detected between the different watering frequencies. The temporal heterogeneity of watering thus appears to have different effects on plant growth at different nutrient levels. Therefore, the watering heterogeneity should be examined with nutrients as unity, because the watering heterogeneity and nutrients affect plant growth in an interactive manner.
Interactions between reserve mobilization and regulation of nitrate uptake during regrowth of Lolium perenne L.: putative roles of amino acids and carbohydrates
Authors: Louahlia S. , Laine P. , MacDuff J. H. , Ourry A. , Humphreys M. , Boucaud J. 
Published: October 2008

In most forage grass and legume species the recovery of leaf growth following severe defoliation depends on mobilization of carbon and nitrogen reserves from the remaining tissues. Unusually, Lolium perenne L. is able to compensate for low levels of available N storage compounds by rapid up-regulation of mineral N uptake. To investigate the physiological basis of this behaviour, perennial ryegrass plants were exposed to a 10 ​d period of optimal mineral N (high-N plants) or zero N (low-N plants) supply before defoliation. N deprivation decreased total N and amino acid concentrations in roots, and increased root water soluble carbohydrate concentrations. Compared with high-N plants (control), fructans and fructose concentrations in roots of low-N plants were 74% and 49% higher, respectively. Low-N plants had higher rates of nitrate uptake following defoliation, and lower amino acid concentrations in the roots (mainly as asparagine and glutamine); a causal role was suggested by the inhibition of nitrate uptake by external root supply of amino acids to low-N plants or by a stimulation of N uptake of high-N plants by sucrose supply to the roots. The results suggest that down-regulation of nitrate uptake following defoliation of plants with high levels of N reserves, may be effected through an increased cycling of amino acids within the plant and by a shortage of carbohydrates. Results are discussed in relation to the proteolytic activities and mobilization of C and N reserves to leaf meristem.
Mire vegetation gradient established as a result of interaction with a water reservoir
Authors: Horn Petr , Bastl Marek 
Published: October 2008

In 1958, 85% of the peat-bog complex Kyselovský les, in the Czech Republic, was flooded with water from the Lipno reservoir. A new vegetation pattern has spontaneously developed in the newly established shoreline and replaced the original peat-bog vegetation dominated by bog pine ( Pinus rotundata Link) forest. This vegetation pattern consists of zonal strips with relatively sharp borders. This zonation is a mosaic of sedge fens, reed canary grass ( Phalaris arundinacea L.) beds, tussock cottongrass ( Eriophorum vaginatum L.) stands, and a community dominated by ericaceous shrubs. The study focused on the vegetation development of this zonal vegetation. Measurements of the water table level, groundwater pH, and conductivity, together with terrain microtopography, were done to estimate the ways in which the water reservoir influences the mire vegetation. The most important factor is lake water fluctuation, which explained most of the vegetation gradient variability. Lake water fluctuations were represented by lake water levels, which directly flooded a certain part of the gradient from 1990 to 2006 for a known number of days.
Orchid–bird interactions: a case study from Angraecum (Vandeae, Angraecinae) and Zosterops (white-eyes, Zosteropidae) on Reunion Island
Authors: Micheneau Claire , Fournel Jacques , Humeau Laurence , Pailler Thierry 
Published: October 2008

Although angraecoid orchids are famous for their spectacular flowers, pollinated by hawkmoths in Madagascar, two species of Angraecum endemic to the Mascarenes (sect. Hadrangis ) have atypical unscented and short-spurred flowers that are pollinated by birds. We focused on the pollination and reproductive success of Angraecum bracteosum Balf.f. & S.Moore, a member of sect. Hadrangis. We investigated the breeding system by performing a set of hand-pollination experiments and by observing natural pollinators using video-captures. Pollinator efficiency (pollen removal and deposition) and reproductive success (fruit set) were quantified once a week in two natural island populations during three consecutive flowering seasons (2003–2005). The orchid is self-compatible but requires pollinator services to achieve reproduction. The two white-eye song-bird species (Zosteropidae) that occur on Reunion, Zosterops borbonicus Boddaert and Zosterops olivaceus L., were recorded as pollinators. However, while pollination events were rare and occasional following flower visits by Z. borbonicus, foraging of Z. oliveaceus resulted in a high frequency of successful pollinations. White-eyes typically perched on inflorescences, and probed most of the “fresh-looking” flowers for nectar. This study documents a probable case of bird-pollination specialization within Angraecum section Hadrangis, and sheds light on the role played by pollinators during the radiation of section Hadrangis in the Mascarene Archipelago.
Description of a novel organ in the gametophyte of the fernSchizaea pusillaand its contribution to overall plant architecture
Authors: Davidson Carla , Prusinkiewicz Przemyslaw , von Aderkas Patrick 
Published: October 2008

Plant architecture is determined by cell division and growth, thus simulation models describing these processes are ideal for determining how local development produces the overall plant form. Because fern gametophytes are structurally simple, they are ideal for investigating the effects of cellular growth and division on plant form. In this work we examine the gametophytic development of Schizaea pusilla Pursh., a small, bog-adapted fern whose gametophyte forms as a mass of single-celled filaments. Using light and scanning electron microscopy we made detailed observations of gametophyte development to generate data for a simulation mechanical model of S. pusilla gametophyte development. To examine how plant architecture is an emergent property of cell division, we constructed a simulation model expressed using the formalism of L-systems. While developing a model of growth in this fern we discovered a previously undescribed structure that contributes to the architecture of this plant, which we term knots. We document the development of knots and demonstrate how they contribute to the overall plant architecture.
Shock brecciation around the Kidd Creek deposit, Abitibi belt, Canada
Authors: Pitcairn I. K. , Arndt N. T. 
Published: October 2008

The Kidd–Munro assemblage, Abitibi belt, Canada, is an ultramafic–mafic–felsic volcanic sequence that contains the giant Kidd Creek volcanic-hosted massive sulfide (VMS) deposit. The Kidd basin, 1.6 km northeast of the deposit, contains pervasively brecciated pillowed and massive basalts. The breccia is distinctly different from most breccias in volcanic rocks, which form through volcanic processes or during later deformation or alteration. The Kidd Creek breccia occurs pervasively through otherwise undeformed pillow interiors and margins, and also in localized corridors of particularly intense brecciation. Clasts are angular, up to 4 cm wide, hosted in a very fine-grained matrix, and commonly show jig-saw fit texture. The chemical compositions of the breccia fragments and matrix are generally similar, although the matrix is slightly enriched in high field-strength elements (HFSE) and heavy rare-earth elements (HREE) and depleted in some mobile elements, such as Rb and Ba. The breccia contains altered basaltic clasts and fragments of in-filled amygdales and is crosscut by late-stage quartz–carbonate–sulfide veins. The observations imply that the breccia was formed in-situ, with minimal transport of material, and developed after solidification of the volcanic rocks. In-situ breccias, such as these, are known to form proximal to major fault zones, but no such structure occurs in the vicinity of the Kidd Basin. We suggest the brecciation was caused by the propagation of shock waves from explosive volcanic eruption, perhaps related to the emplacement of felsic volcanic rocks observed in the Kidd Creek Mine. The breccia was subject to enhanced hydrothermal fluid flow, perhaps linked to the formation of the ore deposit.
Holocene tephras in lake cores from northern British Columbia, Canada
Authors: Lakeman Thomas R. , Clague John J. , Menounos Brian , Osborn Gerald D. , Jensen Britta J.L. , Froese Duane G. 
Published: October 2008

Sediment cores recovered from alpine and subalpine lakes up to 250 km apart in northern British Columbia contain five previously unrecognized tephras. Two black phonolitic tephras, each 5–10 mm thick, occur within 2–4 cm of each other in basal sediments from seven lakes in the Finlay River – Dease Lake area. The upper and lower Finlay tephras are slightly older than 10 220 – 10 560 cal year B.P. and likely originate from two closely spaced eruptions of one or two large volcanoes in the northern Cordilleran volcanic province. The Finlay tephras occur at the transition between deglacial sediments and organic-rich postglacial mud in the lake cores and, therefore, closely delimit the termination of the Fraser Glaciation in northern British Columbia. Sediments in Bob Quinn Lake, which lies on the east edge of the northern Coast Mountains, contain two black tephras that differ in age and composition from the Finlay tephras. The lower Bob Quinn tephra is 3–4 mm thick, basaltic in composition, and is derived from an eruption in the Iskut River volcanic field about 9400 cal years ago. The upper Bob Quinn tephra is 12 mm thick, trachytic in composition, and probably 7000–8000 cal years old. A fifth tephra occurs as a cryptotephra near the top of two cores from the Finlay River area and is correlated to the east lobe of the White River tephra (ca. 1150 cal year B.P.). Although present throughout southern Yukon, the White River tephra has not previously been documented this far south in British Columbia. The tephras are valuable new isochrons for future paleoenvironmental studies in northern British Columbia.
Potential-energy curves of the CH radical molecule under spin-orbit coupling
Authors: Song C , Han H , Zhang Y , Yu Y , Gao T 
Published: October 2008

Potential energy curves for the ground and excited electronic states of the CH radical molecule were calculated employing spin-orbit multiconfiguration quasi-degenerate perturbation theory (SO-MCQDPT). The results of our present SO-MCQDPT calculation for the CH radical molecule indicate that the ground electronic state of X 2Π splits into lower X1 2Π1/2 and higher X2 2Π3/2Ω states. The excited electronic state of a 4Σ– splits into lower a1 4Σ–1/2 and higher a24Σ–3/2, and the excited electronic state of A 2Δ splits into lower A1 2Δ3/2 and higher A2 2Δ5/2. The spin-orbit splittings for the 2S+1Λ states X 2Π, a 4Σ–, and A 2Δ are determined to be 25.963, 0.016, and 0.992 cm–1, respectively. The splittings are in good agreement with the experimental data for X 2Π and A 2Δ , and there are no experimental data for a 4Σ–. The potential-energy curves for all calculated bound states of CH are fitted to an analytical potential-energy function in the large range of R = 0.06–0.55 nm, from which accurate spectroscopic parameters are derived. It is the first time that the eight Ω states (X1 2Π1/2, X2 2Π3/2, a1 4Σ–1/2, a2 4Σ–3/2, A1 2Δ3/2, A2 2Δ5/2, B2Σ–1/2, and C2Σ+1/2) generated from the five valence 2S+1 Λ states (X 2Π , a 4Σ–, A 2Δ, B 2Σ–, and C 2Σ+) among those dissociating up to H(2Sg)+C(1Dg) have been studied theoretically. In addition, the carbon atom was taken as an example to prove the validity of the SO-MCQDPT method. The agreement between calculated and observed spin-orbit coupling is vert good. PACS Nos.: 31.15.aj, 31.15.xh, 71.70.Ej
Sand–rubber mixtures (large rubber chips)
Authors: Kim H.-K. , Santamarina J. C. 
Published: October 2008

Mixtures of small rigid sand particles Dsand large soft rubber particles Drare prepared at different volume fractions and tested to investigate their small-strain and zero-lateral strain responses (Dr /Ds≈ 10). Both data sets are simultaneously gathered in an oedometer cell instrumented with bender elements. Data are analyzed in the context of mixture theory and with the aid of numerical simulations. Results show that the sand skeleton controls the mixture response when the volume fraction of rubber particles is Vrubber ≤ 0.3, while the rubber skeleton prevails at Vrubber ≥ 0.6. The large size and incompressibility of rubber particles provides high stress-induced stiffness in the sand skeleton near the equatorial plane of rubber particles. The corresponding increase in local small-strain shear modulus Gmaxresults in earlier wave arrivals in mixtures with Vrubber ≤ 0.3 than in pure sand, while the quasi-static constrained modulus is highest in pure sand. The constrained modulus and shear wave velocity are power functions of the applied effective stress in all mixtures. Results from this study (Dr /Ds≈ 10) and from a previous complementary study with small rubber particles (Dr /Ds= 0.25) show that the development of internal fabric, particle level processes, and the associated macroscale response of sand–rubber mixtures depend on the relative size between the soft rubber chips and the stiff sand particles Dr /Dsand their volume fractions.
Cyclic AMP-Responsive Element Binding Protein– and Nuclear Factor-κB–Regulated CXC Chemokine Gene Expression in Lung Carcinogenesis
Authors: Sun Hongxia , Chung Wen-Cheng , Ryu Seung-Hee , Ju Zhenlin , Tran Hai T. , Kim Edward , Kurie Jonathan M. , Koo Ja Seok 
Published: October 2008

AbstractThe recognition of the importance of angiogenesis in tumor progression has led to the development of antiangiogenesis as a new strategy for cancer treatment and prevention. By modulating tumor microenvironment and inducing angiogenesis, the proinflammatory cytokine interleukine (IL)-1β has been reported to promote tumor development. However, the factors mediating IL-1β–induced angiogenesis in non–small cell lung cancer (NSCLC) and the regulation of these angiogenic factors by IL-1β are less clear. Here, we report that IL-1β up-regulated an array of proangiogenic CXC chemokine genes in the NSCLC cell line A549 and in normal human tracheobronchial epithelium cells, as determined by microarray analysis. Further analysis revealed that IL-1β induced much higher protein levels of CXC chemokines in NSCLC cells than in normal human tracheobronchial epithelium cells. Conditioned medium from IL-1β–treated A549 cells markedly increased endothelial cell migration, which was suppressed by neutralizing antibodies against CXCL5 and CXCR2. We also found that IL-1β–induced CXC chemokine gene overexpression in NSCLC cells was abrogated with the knockdown of cyclic AMP-responsive element binding protein (CREB) or nuclear factor κB (NF-κB). Moreover, the expression of the CXC chemokine genes as well as CREB and NF-κB activities was greatly increased in the tumorigenic NSCLC cell line compared with normal, premalignant immortalized or nontumorigenic cell lines. A disruptor of the interaction between CREB-binding protein and transcription factors such as CREB and NF-κB, 2-naphthol-AS-E-phosphate (KG-501), inhibited IL-1β–induced CXC chemokine gene expression and angiogenic activity in NSCLC. We propose that targeting CREB or NF-κB using small-molecule inhibitors, such as KG-501, holds promise as a preventive and/or therapeutic approach for NSCLC.