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From crisis management to multi-level interinstitutional partnerships: Development of the southeastern conference deans nursing coalition. J Prof Nurs 2023; 48:66-70. [PMID: 37775243 PMCID: PMC10282598 DOI: 10.1016/j.profnurs.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 06/01/2023] [Accepted: 06/06/2023] [Indexed: 10/01/2023]
Abstract
The Southeastern Conference (SEC) Nursing Dean's Coalition is a purposeful alliance organized to collaboratively address several challenges that arose during the COVID-19 pandemic. Over the last three years, this strategic team of academic leaders has evolved from a crisis response team to a multidimensional support team, leveraging both individual and collective strengths, to provide several benefits to the dean members, as well as other SEC nursing faculty members, students, and institutions. Participation has grown from the original 12 deans to engage a broader team of associate deans and nurse leaders in faculty development, research, service, and diversity, equity, and inclusion. This article describes the origin, evolution, and outcomes of this coalition to date, as well as visions for the future.
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Developing a two‐way learning monitoring program for
Mankarr
(Greater Bilby) in the Western Desert, Western Australia. ECOLOGICAL MANAGEMENT & RESTORATION 2022. [DOI: 10.1111/emr.12543] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
The academic-practice gap in nursing is well documented. Academe is criticized for producing nurses insufficiently prepared to fully participate in patient care. Practice settings are criticized for having unrealistic expectations of new graduates. This article is based on a review of the literature and an exploration of contemporary practices used to bridge academic and practice partnerships. Differences in outcome expectations for new graduates between academe and practice are outlined and consequences of the gap for new graduates, patients, and employers are discussed. Five specific strategies to address the gap are discussed, with the primary realm and responsibility for two falling to education, one to practice, and two to both. Strategies discussed include increased use of simulated learning in nursing education; disruptive innovations in education that promote learner-centered active learning; extended orientation/Transition to Practice Programs for new graduates; dedicated education units; and academic service partnerships. Current literature suggests the viewpoints of academic and practice leaders continue to appear divergent. Closing the gap will require a dedicated and coordinated response from both academe and clinical practice.
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Re-envisioning clinical education for nurse practitioner programs: themes from a national leaders' dialogue. J Prof Nurs 2014; 30:273-8. [PMID: 24939338 DOI: 10.1016/j.profnurs.2014.03.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Indexed: 10/25/2022]
Abstract
As the need for primary care providers increases, nursing education programs face significant challenges to meet future workforce needs. A more resource-efficient approach for the clinical education of nurse practitioner students is needed. A think tank involving 20 thought leaders representing multiple disciplines was convened to discuss this issue. This article presents seven themes that emerged from this national leaders' dialog: academic practice co-design, standardized preclinical preparation, standardized student assessment, entrustable professional activities, immersive clinical experiences, interprofessional education for team-based care, and innovative education practices.
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A Perfect Storm: A Window of Opportunity for Revolution in Nurse Practitioner Education. J Nurs Educ 2012; 51:539-41. [DOI: 10.3928/01484834-20120920-01] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Department of Health and Human Services releases new immersive simulation experience to improve infection control knowledge and practices among health care workers and students. Am J Infect Control 2012; 40:258-9. [PMID: 21784556 DOI: 10.1016/j.ajic.2011.03.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 03/19/2011] [Accepted: 03/21/2011] [Indexed: 11/17/2022]
Abstract
In this article, we review a newly developed evidence-based immersive simulation experience for use with health care personnel and students. The article provides information necessary for infection control professionals to understand the development process of the training. Evidence supporting the use of such training is provided, and opportunities to integrate this training into the health care setting and classroom are discussed.
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A numerical study of combined use of two biocontrol agents with different biocontrol mechanisms in controlling foliar pathogens. PHYTOPATHOLOGY 2011; 101:1032-1044. [PMID: 21385011 DOI: 10.1094/phyto-10-10-0267] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Effective use of biocontrol agents is an important component of sustainable agriculture. A previous numerical study of a generic model showed that biocontrol efficacy was greatest for a single biocontrol agent (BCA) combining competition with mycoparasitism or antibiosis. This study uses the same mathematical model to investigate whether the biocontrol efficacy of combined use of two BCAs with different biocontrol mechanisms is greater than that of a single BCA with either or both of the two mechanisms, assuming that two BCAs occupy the same host tissue as the pathogen. Within the parameter values considered, a BCA with two biocontrol mechanisms always outperformed the combined use of two BCAs with a single but different biocontrol mechanism. Similarly, combined use of two BCAs with a single but different biocontrol mechanism is shown to be far less effective than that of a single BCA with both mechanisms. Disease suppression from combined use of two BCAs was very similar to that achieved by the more efficacious one. As expected, a higher BCA introduction rate led to increased disease suppression. Incorporation of interactions between two BCAs did not greatly affect the disease dynamics except when a mycoparasitic and, to a lesser extent, an antibiotic-producing BCA was involved. Increasing the competitiveness of a mycoparasitic BCA over a BCA whose biocontrol mechanism is either competition or antibiosis may lead to improved biocontrol initially and reduced fluctuations in disease dynamics. The present study suggests that, under the model assumptions, combined use of two BCAs with different biocontrol mechanisms in most cases only results in control efficacies similar to using the more efficacious one alone. These predictions are consistent with published experimental results, suggesting that combined use of BCAs should not be recommended without clear understanding of their main biocontrol mechanisms and relative competitiveness, and experimental evaluation.
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Combined use of biocontrol agents to manage plant diseases in theory and practice. PHYTOPATHOLOGY 2011; 101:1024-1031. [PMID: 21554184 DOI: 10.1094/phyto-08-10-0216] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Effective use of biological control agents (BCAs) is a potentially important component of sustainable agriculture. Recently, there has been an increasing interest among researchers in using combinations of BCAs to exploit potential synergistic effects among them. The methodology for investigating such synergistic effects was reviewed first and published results were then assessed for available evidence for synergy. Correct formulation of hypotheses based on the theoretical definition of independence (Bliss independence or Loewe additivity) and the subsequent and statistical testing for the independence-synergistic-antagonistic interactions have rarely been carried out thus far in studies on biocontrol of plant diseases. Thus, caution must be taken when interpreting reported "synergistic" effects without assessing the original publications. Recent theoretical modeling work suggested that disease suppression from combined use of two BCAs was, in general, very similar to that achieved by the more efficacious one, indicating no synergistic but more likely antagonistic interactions. Only in 2% of the total 465 published treatments was there evidence for synergistic effects among BCAs. In the majority of the cases, antagonistic interactions among BCAs were indicated. Thus, both theoretical and experimental studies suggest that, in combined use of BCAs, antagonistic interactions among BCAs are more likely to occur than synergistic interactions. Several research strategies, including formulation of synergy hypotheses in relation to biocontrol mechanisms, are outlined to exploit microbial mixtures for uses in biocontrol of plant diseases.
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Numerical studies of biocontrol efficacies of foliar plant pathogens in relation to the characteristics of a biocontrol agent. PHYTOPATHOLOGY 2010; 100:814-21. [PMID: 20626285 DOI: 10.1094/phyto-100-8-0814] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A previously published generic mathematic model has been used in a numerical study to understand the dynamics of foliar pathogens in relation to mechanisms, and timing and coverage of biocontrol agent (BCA) applications. With the model parameter values used, it was demonstrated that a BCA possessing either competition or induced resistance as the main mechanism of biological control was more effective in reducing disease development than a BCA with either mycoparasitism or antibiosis as its mechanism. Application coverage, ranging from 50 to 90%, had little effect on biocontrol efficacy, particularly for a BCA with competition and induced resistance as the main mechanism of biocontrol. Conversely, delayed application of BCA had more profound effects on biocontrol efficacy for those with competition or induced resistance as their main mechanism than those with mycoparasitism and antibiosis. Biocontrol efficacy was greatest for a single BCA combining competition with mycoparasitism or antibiosis. The efficacy for a single BCA combining induced resistance with competition critically depended on application time; the efficacy was greatly reduced for delayed applications. The present study suggests that development of an effective strategy for BCA application is critically dependent upon our quantitative understanding of several key biocontrol processes and their interactions. Without reliable quantitative estimation of these processes, it is impossible to make quantitative predictions about biological control and hence to optimize BCA application strategies.
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A generic theoretical model for biological control of foliar plant diseases. J Theor Biol 2008; 256:201-14. [PMID: 18983855 DOI: 10.1016/j.jtbi.2008.09.036] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 08/01/2008] [Accepted: 09/26/2008] [Indexed: 11/16/2022]
Abstract
We have developed a generic modelling framework to understand the dynamics of foliar pathogen and biocontrol agent (BCA) populations in order to predict the likelihood of successful biocontrol in relation to the mechanisms involved. The model considers biocontrol systems for foliar pathogens only and, although it is most applicable to fungal BCA systems, does not address a specific biocontrol system. Four biocontrol mechanisms (competition, antibiosis, mycoparasitism and induced resistance) were included within the model rubric. Because of the wide range of mechanisms involved we use Trichoderma/Botrytis as an exemplar system. Qualitative analysis of the model showed that the rates of a BCA colonising diseased and/or healthy plant tissues and the time that the BCA remains active are two of the more important factors in determining the final outcome of a biocontrol system. Further evaluation of the model indicated that the dynamic path to the steady-state population levels also depends critically on other parameters such as the host-pathogen infection rate. In principle, the model can be extended to include other potential mechanisms, including spatio-temporal heterogeneity, fungicide effects, non-fungal BCA and strategies for BCA application, although with a cost in model tractability and ease of interpretation.
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Abstract
The use of commercially available cryogenic vials (Microbank vials) stored at -70 degrees C for the storage and preservation of dermatophyte fungi was investigated. None of the 200 strains of dermatophytes examined, representing 21 species, showed a loss of viability after they had been stored for periods ranging from 1 week to 2 years at -70 degrees C. All strains showed typical colonial and microscopic morphologies following revival.
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Abstract
BACKGROUND Virtual reality simulators allow trainees to practice techniques without consequences, reduce potential risk associated with training, minimize animal use, and help to develop standards and optimize procedures. Current intravenous (IV) catheter placement training methods utilize plastic arms, however, the lack of variability can diminish the educational stimulus for the student. This study compares the effectiveness of an interactive, multimedia, virtual reality computer IV catheter simulator with a traditional laboratory experience of teaching IV venipuncture skills to both nursing and medical students. METHODS A randomized, pretest-posttest experimental design was employed. A total of 163 participants, 70 baccalaureate nursing students and 93 third-year medical students beginning their fundamental skills training were recruited. The students ranged in age from 20 to 55 years (mean 25). Fifty-eight percent were female and 68% percent perceived themselves as having average computer skills (25% declaring excellence). The methods of IV catheter education compared included a traditional method of instruction involving a scripted self-study module which involved a 10-minute videotape, instructor demonstration, and hands-on-experience using plastic mannequin arms. The second method involved an interactive multimedia, commercially made computer catheter simulator program utilizing virtual reality (CathSim). RESULTS The pretest scores were similar between the computer and the traditional laboratory group. There was a significant improvement in cognitive gains, student satisfaction, and documentation of the procedure with the traditional laboratory group compared with the computer catheter simulator group. Both groups were similar in their ability to demonstrate the skill correctly. CONCLUSIONS; This evaluation and assessment was an initial effort to assess new teaching methodologies related to intravenous catheter placement and their effects on student learning outcomes and behaviors. Technology alone is not a solution for stand alone IV catheter placement education. A traditional learning method was preferred by students. The combination of these two methods of education may further enhance the trainee's satisfaction and skill acquisition level.
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Abstract
AIMS The formation of sectors was observed during subculturing of an isolate of the entomopathogenic fungus Metarhizium anisopliae, a fungus used for biological control of insect pests. The aim of the investigation was to establish whether sector formation was accompanied by changes in physiological characters. METHODS AND RESULTS Four degenerative morphological states, with reduced sporulation capacity, were characterized. Subcultures were taken from each sector and four new culture lines established. The new lines were further subcultured every 21 d. A physiological assessment of each line was undertaken after 42 d using TLC of secondary metabolites and fluorogenic enzyme tests. Full sporulation capacity was not regained on subculture, although some cultures recovered partially. Changes in secondary metabolite profiles and the loss in detection of activity of specific enzymes were observed. CONCLUSIONS Sector formation was frequently accompanied by changes in the ability to produce secondary metabolites and enzymes. SIGNIFICANCE AND IMPACT OF THE STUDY The results illustrate the importance of maintaining the stability of important cultures during routine subculture. The consequences could have significant implications if degenerate cultures are used as inocula for liquid fermentation cultures or industrial scale production.
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Ribotyping of rhizobia nodulating Acacia mangium and Paraserianthes falcataria from different geographical areas in Indonesia using PCR-RFLP-SSCP (PRS) and sequencing. Environ Microbiol 2001; 3:273-80. [PMID: 11359513 DOI: 10.1046/j.1462-2920.2001.00191.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Acacia mangium and Paraserianthes falcataria are leguminous tree species widely grown for timber in Indonesia and other tropical countries, yet little is known about the identity of their rhizobial symbionts. Polymerase chain reaction-restriction fragment length polymorphism-single-strand conformational polymorphism (PRS) analysis of the 16S rRNA gene was used along with sequencing to assess the diversity of 57 rhizobia isolated from nodules of A. mangium and P. falctaria in Indonesia. In total, 26 rhizobia isolated from A. mangium were analysed by PRS and sequencing. The PRS patterns indicated that 12 (46%) clustered with Bradyrhizobium elkanii, 13 (50%) with B. lianoningense/japonicum and one (4%) with Mesorhizobium loti. Thirty-one isolates were analysed from P. falcataria: five (16%) clustered with B. elkanii and 26 (84%) with B. lianoningense/japonicum. These results were confirmed by phylogenetic analysis of sequences. Intraspecific diversity of the 16S rRNA genes from rhizobia nodulating A. mangium and P. falcataria revealed by PRS was low, only one genotype was found within the isolates that clustered with B. elkanii and two within the B. liaoningense/japonicum group. These Bradyrhizobium species are apparently ubiquitous throughout the Indonesian archipelago and it is clear why the two tree species are able to successfully establish outside their native range without the need for inoculation with indigenous rhizobia.
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Developing cryopreservation protocols to secure fungal gene function. CRYO LETTERS 2001; 22:115-24. [PMID: 11788850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Protocols that involve a freezing process are frequently used for the preservation of fungi, but there have been few studies to assess the physiological and genetic stability of isolates after preservation. In this study, the effects of cryopreservation and lyophilisation on the viability, physiology and genetic stability of isolates of Metarhizium anisopliae, Fusarium oxysporum and Serpula lacrymans were examined. It was found that preservation regime influenced the characters of some of the test isolates. Secondary metabolite profiles and extracellular enzyme production can be affected by preservation. Polymorphism's were detected after PCR fingerprinting in replicates of 2 isolates of Metarhizium that had been preserved by cryopreservation and lyophilisation. The results indicated a need to improve existing preservation protocols. Research is being undertaken to develop novel cryopreservation regimes for recalcitrant micro-organisms. Biochemical and molecular techniques will be used to assess the effectiveness of preservation.
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Management of indigenous plant-microbe symbioses aids restoration of desertified ecosystems. Appl Environ Microbiol 2001; 67:495-8. [PMID: 11157208 PMCID: PMC92612 DOI: 10.1128/aem.67.2.495-498.2001] [Citation(s) in RCA: 352] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2000] [Accepted: 11/13/2000] [Indexed: 11/20/2022] Open
Abstract
Disturbance of natural plant communities is the first visible indication of a desertification process, but damage to physical, chemical, and biological soil properties is known to occur simultaneously. Such soil degradation limits reestablishment of the natural plant cover. In particular, desertification causes disturbance of plant-microbe symbioses which are a critical ecological factor in helping further plant growth in degraded ecosystems. Here we demonstrate, in two long-term experiments in a desertified Mediterranean ecosystem, that inoculation with indigenous arbuscular mycorrhizal fungi and with rhizobial nitrogen-fixing bacteria not only enhanced the establishment of key plant species but also increased soil fertility and quality. The dual symbiosis increased the soil nitrogen (N) content, organic matter, and hydrostable soil aggregates and enhanced N transfer from N-fixing to nonfixing species associated within the natural succession. We conclude that the introduction of target indigenous species of plants associated with a managed community of microbial symbionts is a successful biotechnological tool to aid the recovery of desertified ecosystems.
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Molecular differences distinguish clonal lineages within East African populations of Fusarium oxysporum f.sp. cubense. J Appl Microbiol 1999. [DOI: 10.1046/j.1365-2672.1999.00635.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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VEGETATIVE COMPATIBILITY GROUPS WITHIN KENYAN POPULATIONS OF FUSARIUM OXYSPORUM F. SP. CUBENSE. ACTA ACUST UNITED AC 1998. [DOI: 10.17660/actahortic.1998.490.30] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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The detection of Glomus spp. (arbuscular mycorrhizal fungi) forming mycorrhizas in three plants, at different stages of seedling development, using mycorrhiza-specific isozymes. THE NEW PHYTOLOGIST 1998; 138:225-239. [PMID: 33863087 DOI: 10.1046/j.1469-8137.1998.00112.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A series of glasshouse experiments was used to determine mycorrhiza-specific isozymes (MSIs) produced by five species of Glomus colonizing roots of a desert shrub legume (Anthyllis cytisoides L.), Thymus vulgaris L. and Allium porrum L. over time. Extracts of colonized roots were electrophoresed on non-denaturing polyacrylamide gels (PAGE) and stained for 10 different enzymes. Staining protocols for esterase, glutamate oxaloacetate transaminase, alkaline phosphatase and malate dehydrogenase provided MSIs for the mycorrhizas formed by different arbuscular mycorrhizal (AM) fungi that had colonized roots of the three host plants. There was no apparent correlation between levels of colonization or arbuscular intensities, at or between each sampling, and the presence of MSIs. The development of colonization by the AM fungi differed little between the three plants when assessed with two methods of estimating fungal biomass. The variety of MSIs detected might reflect the diversity of metabolic activities of these Glomus species and, possibly, differing ecological functions. The high-level induction of two alkaline phosphatase MSIs in the mycorrhizas of Anthyllis cytisoides colonized by Glomus microaggregatum BEG56 was used to track the fate of this fungus when the same plant was inoculated and transplanted into a semi-arid site in south-east Spain. The probable fungal origin of the isozyme was indicated by detection of the same isozyme in the extraradical mycelium formed by Glomus microaggregatum BEG56 on Allium porrum. The use of MSIs to detect the mycorrhizas of species of Glomus in colonized roots is discussed.
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Abstract
A survey of the natural mycorrhizal potential has been carried out in a representative area of a desertified semiarid ecosystem in the southeast of Spain. Many indigenous plants from the field site were mycorrhizal, including the dominant Anthyllis cytisoides, which had high levels of colonization by arbuscular mycorrhizal fungi (AMF). Low numbers of AMF spores were present in the soil, although a range of species, including Scutellospora calospora, Glomus coronatum, Glomus constrictum, and several Acaulospora species, was represented. Soil infectivities, as determined by a soil dilution method, were similar for most plants tested but were significantly lower for Anthyllis cytisoides. Nevertheless, when a less disruptive method to determine soil infectivity was used, the importance of the mycelial network in maintaining the infectivity of soil under perennial shrubs, such as Anthyllis cytisoides, was highlighted. Seasonal variations in the mycorrhizal infectivity showed that it was higher towards the end of the summer period than in midwinter. In screening trials in a greenhouse, the indigenous AMF did not significantly improve the growth of plants compared with that of noninoculated controls. Augmentation of the soil with an inoculum of Glomus intraradices resulted in improved growth of Anthyllis cytisoides in both sterile and nonsterile conditions, in contrast to results obtained following inoculation with Glomus mosseae or another Glomus sp. Our findings suggest that the indigenous inoculum levels of AMF are inadequate to support an extensive revegetation program in the absence of an additional mycorrhizal inoculum.
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The influence of moisture on the suppression of Pseudomonas syringae by Aureobasidium pullulans on an artificial leaf surface. FEMS Microbiol Ecol 1995. [DOI: 10.1111/j.1574-6941.1995.tb00279.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Production of antibacterial compounds by phylloplane-inhabiting yeasts and yeastlike fungi. Appl Environ Microbiol 1994; 60:927-31. [PMID: 8161185 PMCID: PMC201412 DOI: 10.1128/aem.60.3.927-931.1994] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The production of antibacterial compounds by yeasts and yeastlike fungi isolated from the phylloplane is reported. Aureobasidium pullulans, Citeromyces matritensis, Cryptococcus laurentii, Rhodotorula glutinis, and Sporobolomyces roseus produced antibacterial compounds inhibitory to both Pseudomonas fluorescens and Staphylococcus aureus in an overlay bioassay. In contrast, isolates of Candida albicans, Filobasidium uniguttulatum, Saccharomyces cerevisiae, Torulaspora delbruckii, Tremella foliacea, Trichosporon beigelii, and Trichosporon dulcitum obtained from soil or from culture collections did not produce inhibitory compounds when screened by the same procedure. The production of antibacterial compounds was examined in more detail, using several isolates of A. pullulans distinguished by cluster analysis on the basis of biochemical and physiological tests. They were found to produce a range of antibacterial compounds with different activities. Two distinct antibiotics were produced by an isolate of A. pullulans in liquid culture during both the logarithmic and the stationary phases of growth.
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Effects of fertilizers and arbuscular mycorrhizal fungi on the post-vitro growth of micropropagated strawberry. ACTA ACUST UNITED AC 1992. [DOI: 10.1051/agro:19921020] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Abstract
The infection of leaf and stem tissues of Phaseolus by Sclerotinia sclerotiorum was studied using electron microscopy. Direct entry of the intact plant surface was achieved by hyphae from simple or compound appressoria. A closely appressed hyphal tip developed an electron-lucent region at the apex, in which a plasmalemmal invagination formed. This invagination surrounded a region of extracytoplasmic vesicular material which penetrated the cuticle during invasion. Penetration occurred by a narrow infection peg which passed through the cuticle via a narrow pore and caused little change in cuticle integrity. Once the cuticle was breached, a walled subcuticular vesicle developed from which infection hyphae spread laterally. Destruction of the epidermal cell walls was both rapid and extensive. Leaf and stem colonization occurred by intercellular growth of undifferentiated hyphae accompanied by cellular necrosis in advance of the mycelial front.
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Comparative studies of cultural and biochemical characteristics used for distinguishing species within Sclerotinia. ACTA ACUST UNITED AC 1985. [DOI: 10.1016/s0007-1536(85)80001-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Changes occurring in chloroplasts of Phaseolus following infection by Sclerotinia: a cytochemical study. J Cell Sci 1985; 75:195-205. [PMID: 4044671 DOI: 10.1242/jcs.75.1.195] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dramatic changes occur in the ultrastructure of chloroplasts within host tissues during the infection of Phaseolus by the plant pathogenic fungus Sclerotinia. Electron-opaque deposits develop initially in the peripheral region of the chloroplast stroma, in cells in advance of the hyphal front. As infection continues, the amount and intensity of deposition increases and spreads throughout the chloroplast. The deposits possess a high degree of structural integrity in the form of a crystalline square lattice with 10 nm periodicity. Enzyme digestion studies have been used to show that the deposits are proteinaceous. Similar deposits are also induced by treatment with oxalic and citric acids, but not by the potassium salts of these acids buffered at pH 7.2. It is suggested that a pH change within the chloroplasts, resulting from oxalic acid secretion by the fungus, is responsible for induction of protein deposition. The likelihood that the deposits are ribulose, 1,5-bisphosphate carboxylase-oxygenase is discussed.
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Zygospore Structure in Cokeromyces Recurvatus with Notes on the Asexual Apparatus. Mycologia 1983. [DOI: 10.1080/00275514.1983.12023714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Average similarities of Fourier spectra. APPLIED OPTICS 1980; 19:2661-2663. [PMID: 20234486 DOI: 10.1364/ao.19.002661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Mycoparasitism by Piptocephalis unispora (Mucorales): host range and reaction with Phascolomyces articulosus. ACTA ACUST UNITED AC 1978. [DOI: 10.1139/b78-297] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Using light and electron microscopy, mycoparasitism by Piptocephalis unispora was investigated. Parasitism by P. unispora is restricted to certain members of the Mucorales. Piptocephalis unispora is also shown to infect germinating spores and hyphae of the potential thamnidiaceous host, Phascolomyces articulosus. Appressoria, penetration pegs, and haustoria are formed during the infection process but further development of the mycoparasite ceases. Reaction papillae and material present at infection sites and around degenerate haustoria are associated with the mechanism of resistance. The process of infection is compared with previous studies of the infection of Cokeromyces recurvatus (Thamnidiaceae) by Piptocephalis unispora.
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Ultrastructure of the dormant and germinating sporangiospore of Phascolomyces articulosus (Mucorales). ACTA ACUST UNITED AC 1978. [DOI: 10.1139/b78-085] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Using results obtained with light and scanning electron microscopy of critical-point-dried material and transmission electron microscopy of carbon replicas and freeze-fracture and ultra-thin sections, the structure and germination of the sporangiospore of Phascolomyces articulosus Boedijn is described. The sporangial wall is trilaminate and the ornamented spore wall is two layered. During germination, a new wall layer develops between the plasmalemma and the original spore wall. Sporangial structure is related to that of other members of the Thamnidiaceae and the use of germinating spores of P. articulosus for infection studies of the mycoparasite Piptocephalis unispora is indicated.
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Physiology and fine structure of sporangiospore germination in Piptocephalis unispora prior to infection. Arch Microbiol 1976; 107:99-107. [PMID: 1252091 DOI: 10.1007/bf00427874] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Germination of the sporangiospore of Piptocephalis unispora Benjamin, observed by means of light and electron microscopy, involved the formation of a new inner wall which became continuous with the inner layer of the wall of the germ tube. The outer wall layer of the germ tube was continuous with the original inner wall layer of the dormant spore. Preliminary details of appressorium structure were noted. Nutritional experiments indicated that sporangiospores required external sources of utilisable nitrogen and carbon compounds for maximal swelling and germ tube production. Limited development occurred when either nutrient was supplied singly. Comparison of germination of the asexual spore with that in other Mucorales, especially the Kickxellaceae, has been made, and the merosporangial status in P. unispora discussed.
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Abstract
Sporangiospore structure in Piptocephalis unispora Benjamin was studied using light microscopy, freeze-etching, scanning and transmission electron microscopy, and compared with that of other members of the Mucorales. A merosporangial wall, plasmalemmal invaginations, and wall protuberances were demonstrated in sections and their possible significance discussed.
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