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1.
J Urol ; 206(2): 346-353, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33818139

RESUMO

PURPOSE: Oncologic, urinary, and sexual outcomes are important to patients receiving prostate cancer surgery. The objective of this study was to determine if providing surgical report cards (SuReps) to surgeons resulted in improved patient outcomes. MATERIALS AND METHODS: A prospective before-and-after study was conducted at The Ottawa Hospital. A total of 422 consecutive patients undergoing radical prostatectomy were enrolled. The intervention was provision of report cards to surgeons. The control cohort was patients treated before report card feedback (pre-SuRep), and the intervention cohort was patients treated after report card feedback (post-SuRep). The primary outcomes were postoperative erectile function, urinary continence, and positive surgical margins. RESULTS: Baseline characteristics were similar between groups. Almost all patients (99%) were continent and the majority (59%) were potent prior to surgery. Complete 1-year followup was available for 400 patients (95%). Nerve sparing surgery increased from 70% pre-SuRep to 82% post-SuRep (p=0.01). There was a nonstatistically significant increase in the proportion of patients with a positive surgical margin post-SuRep (31% pre-SuRep vs 39% post-SuRep, p=0.08). There was no difference in postoperative erectile function (17% vs 18%, p=0.7) and a decrease in continence (75% vs 65%, p=0.02) at 1 year postoperatively. CONCLUSIONS: The SuRep platform allows accurate reporting of surgical outcomes that can be used for patient counseling. However, the provision of surgical report cards did not improve functional or oncologic outcomes. Longer durations of feedback, report card modifications, or targeted interventions are likely necessary to improve outcomes.


Assuntos
Competência Clínica , Retroalimentação , Prostatectomia/normas , Melhoria de Qualidade , Cirurgiões , Auditoria Clínica , Estudos Controlados Antes e Depois , Disfunção Erétil/prevenção & controle , Humanos , Masculino , Margens de Excisão , Pessoa de Meia-Idade , Ontário , Complicações Pós-Operatórias , Estudos Prospectivos , Neoplasias da Próstata/cirurgia , Qualidade de Vida , Incontinência Urinária/prevenção & controle
2.
Entropy (Basel) ; 23(7)2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34202081

RESUMO

The Carnot cycle and the attendant notions of reversibility and entropy are examined. It is shown how the modern view of these concepts still corresponds to the ideas Clausius laid down in the nineteenth century. As such, they reflect the outmoded idea, current at the time, that heat is motion. It is shown how this view of heat led Clausius to develop the entropy of a body based on the work that could be performed in a reversible process rather than the work that is actually performed in an irreversible process. In consequence, Clausius built into entropy a conflict with energy conservation, which is concerned with actual changes in energy. In this paper, reversibility and irreversibility are investigated by means of a macroscopic formulation of internal mechanisms of damping based on rate equations for the distribution of energy within a gas. It is shown that work processes involving a step change in external pressure, however small, are intrinsically irreversible. However, under idealised conditions of zero damping the gas inside a piston expands and traces out a trajectory through the space of equilibrium states. Therefore, the entropy change due to heat flow from the reservoir matches the entropy change of the equilibrium states. This trajectory can be traced out in reverse as the piston reverses direction, but if the external conditions are adjusted appropriately, the gas can be made to trace out a Carnot cycle in P-V space. The cycle is dynamic as opposed to quasi-static as the piston has kinetic energy equal in difference to the work performed internally and externally.

3.
Environ Microbiol ; 16(7): 2301-15, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24612372

RESUMO

As a species complex, Pseudomonas syringae exists in both agriculture and natural aquatic habitats. P.viridiflava, a member of this complex, has been reported to be phenotypically largely homogenous. We characterized strains from different habitats, selected based on their genetic similarity to previously described P.viridiflava strains. We revealed two distinct phylogroups and two different kinds of variability in phenotypic traits and genomic content. The strains exhibited phase variation in phenotypes including pathogenicity and soft rot on potato. We showed that the presence of two configurations of the Type III Secretion System [single (S-PAI) and tripartite (T-PAI) pathogenicity islands] are not correlated with pathogenicity or with the capacity to induce soft rot in contrast to previous reports. The presence/absence of the avrE effector gene was the only trait we found to be correlated with pathogenicity of P.viridiflava. Other Type III secretion effector genes were not correlated with pathogenicity. A genomic region resembling an exchangeable effector locus (EEL) was found in S-PAI strains, and a probable recombination between the two PAIs is described. The ensemble of the variability observed in these phylogroups of P.syringae likely contributes to their adaptability to alternating opportunities for pathogenicity or saprophytic survival.


Assuntos
Regulação Bacteriana da Expressão Gênica , Variação Genética , Genoma Bacteriano , Pseudomonas syringae/patogenicidade , Pseudomonas/patogenicidade , Solanum tuberosum/microbiologia , Adaptação Biológica , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sistemas de Secreção Bacterianos/genética , Loci Gênicos , Ilhas Genômicas , Genótipo , Fenótipo , Filogenia , Doenças das Plantas/microbiologia , Pseudomonas/classificação , Pseudomonas/genética , Pseudomonas/metabolismo , Pseudomonas syringae/genética , Pseudomonas syringae/metabolismo , Virulência
4.
Glob Chang Biol ; 20(2): 341-51, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24399753

RESUMO

Landscapes influence precipitation via the water vapor and energy fluxes they generate. Biologically active landscapes also generate aerosols containing microorganisms, some being capable of catalyzing ice formation and crystal growth in clouds at temperatures near 0 °C. The resulting precipitation is beneficial for the growth of plants and microorganisms. Mounting evidence from observations and numerical simulations support the plausibility of a bioprecipitation feedback cycle involving vegetated landscapes and the microorganisms they host. Furthermore, the evolutionary history of ice nucleation-active bacteria such as Pseudomonas syringae supports that they have been part of this process on geological time scales since the emergence of land plants. Elucidation of bioprecipitation feedbacks involving landscapes and their microflora could contribute to appraising the impact that modified landscapes have on regional weather and biodiversity, and to avoiding inadvertent, negative consequences of landscape management.


Assuntos
Bactérias/metabolismo , Planeta Terra , Ecossistema , Gelo , Chuva , Atmosfera , Bactérias/classificação
5.
Pest Manag Sci ; 80(1): 65-71, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37682845

RESUMO

The high-level view of global food systems identifies three all-encompassing barriers to the adoption of food systems solutions: knowledge, policy, and finance. These barriers, and the siloed characteristics of each of these, have hindered the development and adoption of microbial herbicides. How knowledge, policy, and finance are related to the Toothpick Project's path of commercializing a new bioherbicide, early in the scope of the industry, is discussed here. The Toothpick Project's innovation, developed over four decades and commercialized in 2021, uses strains of Fusarium oxysporum f.sp. strigae selected for overproduction and excretion of specific amino acids, killing the parasitic weed Striga hermonthica (Striga or witchweed), Africa's worst pest threat to food security. Historically, bioherbicides have not been a sufficient alternative to the dominant use of synthetic chemical herbicides. To be used safely as bioherbicides, plant pathogens need to be host specific, non-toxic, and yet sufficiently virulent to control a specific weed. For commercialization, bioherbicides must be affordable and require a sufficient shelf life for distribution. Given the current triple storm encountered by the chemical herbicide industry (herbicide-resistant weeds, lawsuits, and consumer pushback), there exists an opportunity to use certain plant pathogens as bioherbicides by enhancing their virulence. By discussing barriers in the scope of knowledge, policy, and finance in the development of the Toothpick Project's new microbial bioherbicide, we hope to help others to anticipate the challenges and provide change-leaders, particularly in policy and finance, a ground level perspective of bioherbicide development. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Herbicidas , Striga , Quênia , Virulência , Plantas Daninhas , Herbicidas/farmacologia
6.
Pest Manag Sci ; 80(1): 149-155, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37139834

RESUMO

Witchweed (Striga hermonthica), also called striga, is a parasitic weed that causes high yield losses in maize on more than 200 000 ha in Kenya alone. A new commercial, biological herbicide developed in Kenya is able to control striga effectively. The product was approved for use by the Pest Control Products Board in Kenya in September, 2021. It is self-produced in villages using a secondary inoculum provided by a commercial company. The formulated product has some disadvantages, which are a complicated production process, a very short shelf life and high application rate. Additionally, the product has to be applied manually and therefore can only be used in manual production, leaving out the opportunity for farmers using mechanization. For this reason, efforts have been made to formulate the active ingredient Fusarium oxysporum f. sp. strigae strain DSM 33471, as a powder and to use it as a seed coating agent. This article deals with the production of the Fusarium spore powder, its properties, its application to the seed, and its herbicidal effect demonstrated in the first two field trials. The F. oxysporum strain was originally isolated from a wilting striga plant in Kenya. The strain was virulence enhanced to over produce the amino acids leucine, methionine and tyrosine. These amino acids are responsible for a second mode of action apart from the wilting causing effect of the fungus on striga. Whereas leucine and tyrosine have a herbicidal effect, ethylene from methionine triggers the germination of striga seeds in the soil. Additionally, the strain has been improved to be resistant to the fungicide captan, which is commonly used to treat maize seed in Kenya. Seed coating tests conducted on 25 striga-infested small holder farms spread out in six counties of western Kenya reported yield increases of up to 88%. A second trial carried out by the Kenyan Agricultural and Livestock Research Organization showed a 93% reduction of emerged striga plants. © 2023 Society of Chemical Industry.


Assuntos
Striga , Quênia , Leucina , Pós/farmacologia , Sementes , Tirosina/farmacologia , Metionina
7.
PLoS One ; 18(5): e0255764, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37216356

RESUMO

Potatoes are a dietary staple consumed by a significant portion of the world, providing valuable carbohydrates and vitamins. However, most commercially produced potatoes have a high content of highly branched amylopectin starch, which generally results in a high glycemic index (GI). Consumption of foods with high levels of amylopectin elicit a rapid spike in blood glucose levels, which is undesirable for individuals who are pre-diabetic, diabetic, or obese. Some cultivars of potatoes with lower amylopectin levels have previously been identified and are commercially available in niche markets in some countries, but they are relatively unavailable in the United States and Latin America. The high glycemic index of widely available potatoes presents a problematic "consumer's dilemma" for individuals and families that may not be able to afford a better-balanced, more favorable diet. Some native communities in the Andes (Bolivia, Chile, and Peru) reportedly embrace a tradition of providing low glycemic tubers to people with obesity or diabetes to help people mitigate what is now understood as the negative effects of high blood sugar and obesity. These cultivars are not widely available on a global market. This study examines 60 potato cultivars to identify potatoes with low amylopectin. Three independent analyses of potato starch were used: microscopic examination of granule structure, water absorption, and spectrophotometric analysis of iodine complexes to identify potato cultivars with low amylopectin Differences among cultivars tested were detected by all three types of analyses. The most promising cultivars are Huckleberry Gold, Muru, Multa, Green Mountain, and an October Blue x Colorado Rose cross. Further work is necessary to document the ability of these low amylopectin cultivars to reduce blood glucose spike levels in human subjects.


Assuntos
Solanum tuberosum , Amido , Humanos , Amido/química , Amilopectina/química , Solanum tuberosum/química , Glicemia , Obesidade
8.
Urol Pract ; 9(4): 294-305, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37145778

RESUMO

INTRODUCTION: Same-day discharge (SDD) following robot-assisted radical prostatectomy (RARP) is emerging as the standard of care. We conducted a systematic review and meta-analysis to evaluate the differences in perioperative characteristics, complication/readmissions rates and satisfaction/cost data between inpatient (IP) RARP and SDD RARP. METHODS: This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was prospectively registered with PROSPERO (CRD42021258848). A comprehensive search of PubMed®, Embase®, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov and conference abstract publications was performed. A leave-one-out sensitivity analysis was performed to control for heterogeneity and risk of bias. RESULTS: A total of 14 studies were included with a pooled population of 3,795 patients, including 2,348 (61.9%) IP RARPs and 1,447 (38.1%) SDD RARPs. SDD pathways varied, though many commonalities were present in patient selection, perioperative recommendations and postoperative management. When compared to IP RARP, SDD RARP had no differences in ≥grade 3 Clavien-Dindo complications (RR: 0.4, 95% CI 0.2, 1.1, p=0.07), 90-day readmission rates (RR: 0.6, 95% CI 0.3, 1.1, p=0.10) or unscheduled emergency department visits (RR: 1.0, 95% CI 0.3, 3.1, p=0.97). Cost savings per patient ranged between $367 and $2,109, and overall satisfaction was high at 87.5%-100%. CONCLUSIONS: SDD following RARP is both feasible and safe, while potentially offering health care cost savings with high patient satisfaction rates. Data from this study will inform the uptake and development of future SDD pathways in contemporary urological care such that it may be offered to a broader patient population.

9.
Proc Natl Acad Sci U S A ; 105(48): 18854-9, 2008 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-19028877

RESUMO

Biological ice nucleators (IN) function as catalysts for freezing at relatively warm temperatures (warmer than -10 degrees C). We examined the concentration (per volume of liquid) and nature of IN in precipitation collected from Montana and Louisiana, the Alps and Pyrenees (France), Ross Island (Antarctica), and Yukon (Canada). The temperature of detectable ice-nucleating activity for more than half of the samples was > or = -5 degrees C based on immersion freezing testing. Digestion of the samples with lysozyme (i.e., to hydrolyze bacterial cell walls) led to reductions in the frequency of freezing (0-100%); heat treatment greatly reduced (95% average) or completely eliminated ice nucleation at the measured conditions in every sample. These behaviors were consistent with the activity being bacterial and/or proteinaceous in origin. Statistical analysis revealed seasonal similarities between warm-temperature ice-nucleating activities in snow samples collected over 7 months in Montana. Multiple regression was used to construct models with biogeochemical data [major ions, total organic carbon (TOC), particle, and cell concentration] that were accurate in predicting the concentration of microbial cells and biological IN in precipitation based on the concentration of TOC, Ca(2+), and NH(4)(+), or TOC, cells, Ca(2+), NH(4)(+), K(+), PO(4)(3-), SO(4)(2-), Cl(-), and HCO(3)(-). Our results indicate that biological IN are ubiquitous in precipitation and that for some geographic locations the activity and concentration of these particles is related to the season and precipitation chemistry. Thus, our research suggests that biological IN are widespread in the atmosphere and may affect meteorological processes that lead to precipitation.


Assuntos
Geografia , Gelo , Chuva/química , Estações do Ano , Neve/química , Regiões Antárticas , Precipitação Química , Análise por Conglomerados , Clima Frio , Cristalização , França , Louisiana , Montana , Chuva/microbiologia , Neve/microbiologia , Temperatura , Água/análise , Yukon
10.
J Immigr Minor Health ; 20(4): 763-765, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28735454

RESUMO

The number of Internally Displaced People is growing globally with a significant number travelling to countries such as Canada. These individuals have unique health care needs that are significantly impacted by several social determinants of health, which provides a challenge to the physician as they must address the biological, psychological and social factors in order to effectively improve the health of this population. The physician must work at the individual, national, and international levels and collaborate with other health care workers in order to effectively address these complex health care issues. Some recent strategies that show promise in targeting these complex care issues include knowledge sharing among medical professionals, specialized treatment approaches including treatment through telemedicine as well as political advocacy. The application of strategies such as these, along with increased awareness and commitment from physicians, will work to improve health care and prevent negative health outcomes in this growing population.


Assuntos
Atenção à Saúde/organização & administração , Emigrantes e Imigrantes , Nível de Saúde , Saúde Mental/etnologia , Papel do Médico , Canadá , Comportamento Cooperativo , Humanos , Disseminação de Informação , Política , Saúde da População , Trauma Psicológico/etnologia , Determinantes Sociais da Saúde/etnologia , Estresse Psicológico/etnologia , Telemedicina/organização & administração , Populações Vulneráveis/etnologia
11.
Can J Ophthalmol ; 53(4): 349-353, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30119788

RESUMO

OBJECTIVE: To assess corticosteroid-sparing and inflammation control in patients with noninfectious scleritis treated with methotrexate. DESIGN: Retrospective review. PARTICIPANTS: Patients who received methotrexate treatment for noninfectious scleritis and who had 12 months of follow-up after treatment initiation were included in this review. METHODS: The clinical records of noninfectious scleritis patients presenting at the University of Ottawa Eye Institute between September 1, 2010 and December 31, 2014 treated with methotrexate were retrospectively reviewed. Seventeen patients (21 eyes) were included in the study. Main outcome included inflammation control and corticosteroid-sparing success. Secondary outcomes were reduction of immunosuppression load and best-corrected visual acuity. RESULTS: The proportion of eyes with corticosteroid-sparing success was 69.2% at 3 months and 92.3% at 12 months. The proportion of eyes that achieved inflammation control was 61.9% at 3 months and 90.5% at 12 months. The corticosteroid immunosuppression load at treatment start was 1.9 ± 2.07 and at 12 months was 0.48 ± 1.03 (p < 0.01). There was no statistically significant difference in best-corrected visual acuity. CONCLUSIONS: The treatment of noninfectious scleritis with methotrexate appears to be effective at both achieving steroid-sparing success and controlling inflammation during 12 months of therapy. Immunosuppression load decreased significantly over 12 months of therapy while best corrected visual acuity was stable.


Assuntos
Metotrexato/administração & dosagem , Esclera/patologia , Esclerite/tratamento farmacológico , Acuidade Visual , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Humanos , Imunossupressores/administração & dosagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Esclerite/diagnóstico , Resultado do Tratamento
12.
Infect Genet Evol ; 7(1): 84-92, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16807133

RESUMO

The biology and ecology of plant pathogenic bacteria have been studied almost exclusively in agricultural contexts. In contrast, for numerous human pathogens their biological activity in niches outside of medical contexts is well-known. Whereas there is increasing evidence that traits fostering survival in 'environmental' niches can be the basis for virulence factors of human pathogens, niches for plant pathogenic bacteria outside of plants or of agricultural settings have not been elucidated. Most phytopathogenic bacteria are not obligate parasites, some of them can be transported to altitudes of several kilometres, they are scrubbed from the atmosphere by rainfall, and thus they are presumably transported to and might survive in a wide range of habitats. We isolated Pseudomonas syringae from river epilithon (rock-attached biofilms composed of algae, diatoms, rotifers, bacteria and nematodes) at densities up to 6000 cells g(-1) in France and the USA, some in pristine settings where waters flowed directly from snow melt and had not passed through agricultural zones. These strains induced hypersensitivity in indicator plants (tobacco) suggesting the presence of functional pathogenicity systems, and many induced disease in 1-7 of the plant species tested and produced a syringomycin-like toxin. Strains also were resistant to some antibiotics used to control plant diseases but not to copper sulphate. Sequencing of the 16S rDNA of epilithon strains and of reference strains of P. syringae revealed that a genetic lineage containing the strains with the broadest host range was distributed across several continents. Is it likely that wide spread dissemination of P. syringae occurs via aerosols and precipitation. This work highlights our limited understanding of non-agricultural niches in the ecology and evolution of plant pathogenic bacteria, of their role in the development of agricultural epidemics both as sources of inoculum and as sources of novel traits that may enhance bacterial pathogenicity and fitness.


Assuntos
Fenômenos Fisiológicos Bacterianos , Plantas/microbiologia , Pseudomonas syringae/fisiologia , Filogenia , Pseudomonas syringae/genética , Pseudomonas syringae/patogenicidade
13.
HSS J ; 13(1): 2-6, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28167866

RESUMO

BACKGROUND: The current role of metal-on-metal (MoM) bearings in hip arthroplasty remains controversial. The low wear offered by MoM bearings compared to metal-on-polyethylene and the possibility of a lower risk of dislocation with larger head sizes, encouraged a trend towards the re-introduction of the MoM bearing couple. However, recent evidence has shown that not all designs of the MoM bearing have been successful. QUESTIONS/PURPOSES: The purpose of this paper is to provide an update on the use of MoM bearings and address the following issues: (1) the reintroduction of metal-on-metal bearings in total hip arthroplasty, (2) the failure of metal-on-metal bearings in stemmed total hip arthroplasty, (3) the role of metal-on-metal hip resurfacing in modern orthopaedics and (4) metal-on-metal hip resurfacing versus total hip arthroplasty. METHODS: A literature search strategy was conducted using various search terms in MEDLINE and Embase. The highest quality articles that met the inclusion criteria and best answered the topics of focus of this review were selected. Key search terms included 'metal-on-metal', 'total hip arthroplasty' and 'hip resurfacing'. RESULTS: The initial search retrieved 1240 articles. Twenty-two articles were selected and used in the review. CONCLUSION: Metal-on-metal hip resurfacing is still a suitable treatment option in specific patient populations with the appropriate implant design and surgical skill, while stemmed metal-on-metal total hip arthroplasty should be avoided in all patient populations. Continued follow-up of patients undergoing metal-on-metal hip resurfacing is critical in order to further understand the long-term outcomes of these patients and why certain complications tend to occur with this procedure.

14.
Urol Pract ; 9(4): 304-305, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37145792
15.
Front Plant Sci ; 8: 842, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28588599

RESUMO

Certain amino acids induce inhibitory effects in plant growth due to feedback inhibition of metabolic pathways. The inhibition patterns depend on plant species and the plant developmental stage. Those amino acids with inhibitory action on specific weeds could be utilized as herbicides, however, their use for weed control has not been put into practice. Orobanche minor is a weed that parasitizes red clover. O. minor germination is stimulated by clover root exudates. The subsequent seedling is an obligated parasite that must attach quickly to the clover root to withdraw its nutrients. Early development of O. minor is vulnerable to amino acid inhibition and therefore, a series of in vitro, rhizotron, and field experiments were conducted to investigate the potential of amino acids to inhibit O. minor parasitism. In in vitro experiments it was found that among a collection of 20 protein amino acids, lysine, methionine and tryptophan strongly interfere with O. minor early development. Field research confirmed their inhibitory effect but revealed that methionine was more effective than lysine and tryptophan, and that two successive methionine applications at 308 and 543 growing degree days inhibited O. minor emergence in red clover up to 67%. We investigated additional effects with potential to influence the practical use of amino acids against broomrape weeds, whether the herbicidal effect may be reversible by other amino acids exuded by host plants or may be amplified by inducing host resistance barriers against O. minor penetration. This paper suggests that amino acids may have the potential to be integrated into biorational programs of broomrape management.

17.
Front Plant Sci ; 7: 1121, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27551284

RESUMO

Striga hermonthica (witchweed) is a parasitic weed that attacks and significantly reduces the yields of maize, sorghum, millet, and sugarcane throughout sub-Saharan Africa. Low cost management methods such as hand weeding, short crop rotations, trap cropping, or conventional biocontrol have not been effective. Likewise, Striga-tolerant or herbicide-resistant maize cultivars are higher yielding, but are often beyond the economic means of sustenance farmers. The fungal pathogen, Fusarium oxysporum f.sp. strigae, has been the object of numerous studies to develop Striga biocontrol. Under experimental conditions this pathogen can reduce the incidence of Striga infestation but field use is not extensive, perhaps because it has not been sufficiently effective in restoring crop yield and reducing the soil Striga seed bank. Here we brought together Kenyan and US crop scientists with smallholder farmers to develop and validate an effective biocontrol strategy for management of Striga on smallholder farms. Key components of this research project were the following: (1) Development of a two-step method of fungal delivery, including laboratory coating of primary inoculum on toothpicks, followed by on-farm production of secondary field inoculum in boiled rice enabling delivery of vigorous, fresh inoculum directly to the seedbed; (2) Training of smallholder farmers (85% women), to produce the biocontrol agent and incorporate it into their maize plantings in Striga-infested soils and collect agronomic data. The field tests expanded from 30 smallholder farmers to a two-season, 500-farmer plot trial including paired plus and minus biocontrol plots with fertilizer and hybrid seed in both plots and; (3) Concerted selection of variants of the pathogen identified for enhanced virulence, as has been demonstrated in other host parasite systems were employed here on Striga via pathogen excretion of the amino acids L-leucine and L-tyrosine that are toxic to Striga but innocuous to maize. This overall strategy resulted in an average of >50% increased maize yield in the March to June rains season and >40% in the September to December rains season. Integration of this enhanced plant pathogen to Striga management in maize can significantly increase the maize yield of smallholder farmers in Kenya.

19.
PLoS One ; 9(9): e105547, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25184292

RESUMO

The Pseudomonas syringae complex is composed of numerous genetic lineages of strains from both agricultural and environmental habitats including habitats closely linked to the water cycle. The new insights from the discovery of this bacterial species in habitats outside of agricultural contexts per se have led to the revelation of a wide diversity of strains in this complex beyond what was known from agricultural contexts. Here, through Multi Locus Sequence Typing (MLST) of 216 strains, we identified 23 clades within 13 phylogroups among which the seven previously described P. syringae phylogroups were included. The phylogeny of the core genome of 29 strains representing nine phylogroups was similar to the phylogeny obtained with MLST thereby confirming the robustness of MLST-phylogroups. We show that phenotypic traits rarely provide a satisfactory means for classification of strains even if some combinations are highly probable in some phylogroups. We demonstrate that the citrate synthase (cts) housekeeping gene can accurately predict the phylogenetic affiliation for more than 97% of strains tested. We propose a list of cts sequences to be used as a simple tool for quickly and precisely classifying new strains. Finally, our analysis leads to predictions about the diversity of P. syringae that is yet to be discovered. We present here an expandable framework mainly based on cts genetic analysis into which more diversity can be integrated.


Assuntos
Citrato (si)-Sintase/genética , Genes Bacterianos , Genoma Bacteriano , Filogenia , Pseudomonas syringae , Sequência de Bases , Bases de Dados Genéticas , Ecossistema , Genes Essenciais , Variação Genética , Genótipo , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Fenótipo , Pseudomonas syringae/classificação , Pseudomonas syringae/genética
20.
Genome Announc ; 2(1)2014 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-24459267

RESUMO

Here, we report the draft genome sequences for 7 phylogenetically diverse isolates of Pseudomonas syringae, obtained from numerous environmental sources and geographically proximate crop species. Overall, these sequences provide a wealth of information about the differences (or lack thereof) between isolates from disease outbreaks and those from other sources.

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