25 research outputs found

    Vesicular-arbuscular Mycorrhizal Inoculation of Hawaiian Plants: A Conservation Technique for Endangered Tropical Species

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    Forty species of plants (including 28 species endemic to the Hawaiian Islands) were evaluated in the greenhouse for their response to inoculation with the vesicular-arbuscular mycorrhizal fungus Glomus intraradices Schenck & Smith. Seedlings, cuttings, and established plants were inoculated. Several kinds of growth media were used. Increased growth and survival most frequently occurred when plants were grown in a gravel or fine sand medium that included calcined clay (up to 50% by volume) or sphagnum peat (up to 20%). Significant increases in height, weight, leaf number and size, and survival were noted in 10 of 14 species of seedlings grown in media in which peat content was 20% or less. Mycorrhizae were only rarely present in the noninoculated plants except for plants grown from cuttings. The latter routinely formed mycorrhizae in the absence of added inoculum. Addition of mycorrhizal fungi to potting mixes appears to have value as a conservation technique for some plants that are difficult to propagate

    Mycorrhizal Status of Gunnera petaloidea in Hawai'i

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    Eight collections of the endemic Hawaiian angiosperm Gunnera petaloidea ssp. kauaiensis were examined for mycorrhizae. Soil-inhabiting roots of all specimens possessed extensive vesicular-arbuscular mycorrhizae 01AM). Aerial roots lacked mycorrhizae. Soil from the root zones of the plants contained propagules of VAM fungi, and spores of two species of VAM fungi were found in the soil. The discovery of mycorrhizae in Gunnera adds another symbiont to the Gunnera-Nostoc symbiosis

    Do graduate entry nursing student’s experience ‘Imposter Phenomenon’?: an issue for debate

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    The recruitment of Graduates into the nursing profession is seen as advantageous in the academic literature. Conversely educated nurses are often portrayed in the media as “too posh to wash”. We would argue these conflicting discourses have a negative effect on graduate entry nurse education. Graduate nursing students may be particularly susceptible to “Imposter Phenomenon” a concept that describes an "internal experience of intellectual phoniness" exhibited by individuals who appear successful to others, but internally feel incompetent. We would like to encourage debate through the presentation of a small set of pilot data that established that 74% of the participants had frequent to intense experiences of Imposter Phenomenon. Students experienced feelings of failure despite consistent high achievement. Our findings and the prevalent negative rhetoric surrounding highly educated student nurses raise concerns regarding the impact of the anti-intellectualism on the Graduate entry student’s perception of self. Others may argue that this could simply be a 'natural' or expected level of anxiety in a time of transition that has no lasting impact. We debate this issue in relation to the existing literature to encourage critical dialogue

    Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk

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    BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4×10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific associat

    Common and rare variant association analyses in amyotrophic lateral sclerosis identify 15 risk loci with distinct genetic architectures and neuron-specific biology

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    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a lifetime risk of one in 350 people and an unmet need for disease-modifying therapies. We conducted a cross-ancestry genome-wide association study (GWAS) including 29,612 patients with ALS and 122,656 controls, which identified 15 risk loci. When combined with 8,953 individuals with whole-genome sequencing (6,538 patients, 2,415 controls) and a large cortex-derived expression quantitative trait locus (eQTL) dataset (MetaBrain), analyses revealed locus-specific genetic architectures in which we prioritized genes either through rare variants, short tandem repeats or regulatory effects. ALS-associated risk loci were shared with multiple traits within the neurodegenerative spectrum but with distinct enrichment patterns across brain regions and cell types. Of the environmental and lifestyle risk factors obtained from the literature, Mendelian randomization analyses indicated a causal role for high cholesterol levels. The combination of all ALS-associated signals reveals a role for perturbations in vesicle-mediated transport and autophagy and provides evidence for cell-autonomous disease initiation in glutamatergic neurons.peer-reviewe

    Mycorrhizal Status of Two Hawaiian Plant Species (Asteraceae) in a Tropical Alpine Habitat: The Threatened Haleakala Silversword (Argyroxiphium sandwicense subsp. macrocephalum) and the Endemic Dubautia menziesii

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    Samples of roots and root-zone soil from the threatened species Argyroxiphium sandwicense subsp. macrocephalum and the endemic species Dubautia menziesii, both members of the Asteraceae, were collected in a tropical alpine area in Haleakala National Park, Maui, Hawai'i, and examined for arbuscular mycorrhizal fungi (AMF). All root samples exhibited the Paris-type of mycorrhizae with arbuscules produced on hyphal coils, and all soil collections included spores of AMF. Spores of Acaulospora, Entrophospora, Glomus, and Scutellospora spp. were recovered from this site

    Mycorrhizae in Hawaiian Epiphytes

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    In surveys in the Hawaiian Islands, mycorrhizae occurred frequently in epiphytic, nonorchidaceous angiosperms and pteridophytes. Both vesicular-arbuscular (VA) and ericoid mycorrhizae were present in epiphytes growing 1-3 m above the forest floor on dead and living tree trunks and on living tree ferns in montane wet forest sites. All eight angiosperm species were mycorrhizal, and 13 of 22 pteridophytes possessed VA mycorrhizae. The high frequency of mycorrhizae in epiphytic species suggests that propagules of mycorrhizal fungi routinely are dispersed to these microsites. Possible means of dispersal are discussed

    Arbuscular Mycorrhizal Fungi in Hawaiian Sand Dunes: Island of Kaua'i

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    Fourteen species of arbuscular mycorrhizal (AM) fungi were isolated from the roots of plants growing on sand dunes of Kaua'i. The dominant AM fungal species included Scutellospora hawaiiensis Koske & Gemma, Glomus 807 (an undescribed species), G. intraradices Schenck & Smith, and G. spurcum Walker ined. Species richness per sample was low and ranged from 0 to 6 (avg. 2.0). Mean abundance of live spores was 8.9 spores per 100 cm3, and many more dead or parasitized spores were present. The AM fungal community of the dunes of Kaua'i was very similar to that of the dunes of the island of Hawai'i. The long-distance dispersal mechanisms and similarity of habitats that have resulted in a relatively uniform angiosperm flora on dunes of the tropical Pacific may have produced a corresponding AM fungal community in these sites

    Arbuscular Mycorrhizae Effects on Growth of Two Hawaiian Species:Indigenous Osteomeles anthyllidifolia (Rosaceae) and Invasive Psidium cattleianum (Myrtaceae).

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    v. ill. 23 cm.QuarterlyTwo important plant species of Hawai‘i, the indigenous Osteomeles anthyllidifolia (Sm.) Lindl., a component of Hawai‘i’s most endangered habitat, and the highly invasive Psidium cattleianum Sabine were grown with or without arbuscular mycorrhizal fungi in a soilless mix at different soil solution phosphorus (P) levels. At P levels similar to those in the field (0.007 mg P/liter), shoot biomass of inoculated plants of O. anthyllidifolia was 189% greater than that of controls, and that of P. cattleianum was 93% greater. Root weight of O. anthyllidifolia and leaf-tissue P of both species also were significantly higher in inoculated plants. At a higher concentration of soil-solution P (0.020 mg P/liter), inoculated plants of O. anthyllidifolia had 176% more biomass than controls, and those of P. cattleianum had 49% more. In a growth medium with soilsolution P equivalent to that of good agricultural soil (0.200 mg P/liter), inoculated plants of O. anthyllidifolia were 101% larger than controls. Results suggest that presence of arbuscular mycorrhizal fungi is of vital importance to establishment of O. anthyllidifolia in Hawaiian soils and that their absence may limit P. cattleianum invasion of sites that are highly deficient in available P
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