415 research outputs found

    Internal Colonization of Salmonella enterica Serovar Typhimurium in Tomato Plants

    Get PDF
    Several Salmonella enterica outbreaks have been traced back to contaminated tomatoes. In this study, the internalization of S. enterica Typhimurium via tomato leaves was investigated as affected by surfactants and bacterial rdar morphotype, which was reported to be important for the environmental persistence and attachment of Salmonella to plants. Surfactants, especially Silwet L-77, promoted ingress and survival of S. enterica Typhimurium in tomato leaves. In each of two experiments, 84 tomato plants were inoculated two to four times before fruiting with GFP-labeled S. enterica Typhimurium strain MAE110 (with rdar morphotype) or MAE119 (without rdar). For each inoculation, single leaflets were dipped in 109 CFU/ml Salmonella suspension with Silwet L-77. Inoculated and adjacent leaflets were tested for Salmonella survival for 3 weeks after each inoculation. The surface and pulp of ripe fruits produced on these plants were also examined for Salmonella. Populations of both Salmonella strains in inoculated leaflets decreased during 2 weeks after inoculation but remained unchanged (at about 104 CFU/g) in week 3. Populations of MAE110 were significantly higher (P<0.05) than those of MAE119 from day 3 after inoculation. In the first year, nine fruits collected from one of the 42 MAE119 inoculated plants were positive for S. enterica Typhimurium. In the second year, Salmonella was detected in adjacent non-inoculated leaves of eight tomato plants (five inoculated with strain MAE110). The pulp of 12 fruits from two plants inoculated with MAE110 was Salmonella positive (about 106 CFU/g). Internalization was confirmed by fluorescence and confocal laser microscopy. For the first time, convincing evidence is presented that S. enterica can move inside tomato plants grown in natural field soil and colonize fruits at high levels without inducing any symptoms, except for a slight reduction in plant growth

    Proyecto de producción y exportación de dulce de membrillo a inmigrantes ecuatorianos que residen en la ciudad de nueva york, estados unidos

    Get PDF
    Project Production and Export of Sweet Quince aims to reach the market for Ecuadorian migrants residing in the New York City. The market strategy is to appeal to the sentiment of the Ecuadorian immigrants, who yearn to enjoy its typical products of Ecuador. Through market research, it was determined that there is a high degree of acceptance of the product. About 90% of respondents, who have already tried sweet quince, are willing to buy the product. 16% of people who consume traditional sweets Ecuadorians in New York City, they qualify sweet quince as your preference. Regarding the Technical Study emphasizes that the project does not require a large investment in terms of investment in equipment and physical works, which becomes attractive relative to the project. In the Financial Study two scenarios were developed, one with a debt of 40% debt and 60% equity and the other method under 100% of equity. In both cash flows the NPV is a positive value and the IRR is higher than TMAR, making the project profitable

    Explanation and Elaboration Document for the STROBE-Vet Statement: Strengthening the Reporting of Observational Studies in Epidemiology—Veterinary Extension

    Get PDF
    The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement was first published in 2007 and again in 2014. The purpose of the original STROBE was to provide guidance for authors, reviewers and editors to improve the comprehensiveness of reporting; however, STROBE has a unique focus on observational studies. Although much of the guidance provided by the original STROBE document is directly applicable, it was deemed useful to map those statements to veterinary concepts, provide veterinary examples and highlight unique aspects of reporting in veterinary observational studies. Here, we present the examples and explanations for the checklist items included in the STROBE-Vet Statement. Thus, this is a companion document to the STROBE-Vet Statement Methods and process document, which describes the checklist and how it was developed

    Methods and Processes of Developing the Strengthening the Reporting of Observational Studies in Epidemiology – Veterinary (STROBE-Vet) Statement

    Get PDF
    BACKGROUND Reporting of observational studies in veterinary research presents challenges that often are not addressed in published reporting guidelines. OBJECTIVE To develop an extension of the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement that addresses unique reporting requirements for observational studies in veterinary medicine related to health, production, welfare, and food safety. DESIGN Consensus meeting of experts. SETTING Mississauga, Canada. PARTICIPANTS Seventeen experts from North America, Europe, and Australia. METHODS Experts completed a pre-meeting survey about whether items in the STROBE statement should be modified or added to address unique issues related to observational studies in animal species with health, production, welfare, or food safety outcomes. During the meeting, each STROBE item was discussed to determine whether or not rewording was recommended and whether additions were warranted. Anonymous voting was used to determine consensus. RESULTS Six items required no modifications or additions. Modifications or additions were made to the STROBE items 1 (title and abstract), 3 (objectives), 5 (setting), 6 (participants), 7 (variables), 8 (data sources/measurement), 9 (bias), 10 (study size), 12 (statistical methods), 13 (participants), 14 (descriptive data), 15 (outcome data), 16 (main results), 17 (other analyses), 19 (limitations), and 22 (funding). CONCLUSION The methods and processes used were similar to those used for other extensions of the STROBE statement. The use of this STROBE statement extension should improve reporting of observational studies in veterinary research by recognizing unique features of observational studies involving food-producing and companion animals, products of animal origin, aquaculture, and wildlife

    Estimation of Resilience in University Students

    Get PDF
    The objective of the work is to estimate the resilience level of university students for future resilience interventions. The paper presents a conceptual analysis of the term resilience, based on the criteria of contemporary authors framed in two generations. The methods and techniques used in the work are exposed, where two tools for measuring resilience are highlighted. The importance of the study of resilience in the university environment is discussed and the statistical and graphical results related to the application of the aforementioned instruments are shown in terms of measuring the resilience level in the university students of seven faculties of the Technical University of Manabí

    Autonomy, Good Humor and Support Networks, Potential of Community Resilience Intervention in People Victims of the Earthquake in the Calderón Parish

    Full text link
    Resilience is a concept widely used in recent years, especially when it comes to evaluating the level of recovery of communities that are hit by natural phenomena. It can be stated that conceptually resilience constitutes the ability to react effectively and quickly to the effects of disasters, being a complex phenomenon to evaluate and define. And although the level of resilience does not necessarily imply greater control of vulnerability, it can be affirmed that the reduction of vulnerable conditions can strengthen and consolidate the resilient capacity of individuals and communities, in the face of the effects of natural disasters

    Microbubble-Based Model Analysis of Liquid Breakdown Initiation by a Submicrosecond Pulse

    Get PDF
    An electrical breakdown model for liquids in response to a submicrosecond(∼100ns) voltage pulse is presented, and quantitative evaluations carried out. It is proposed that breakdown is initiated by field emission at the interface of pre-existing microbubbles. Impact ionization within the microbubble gas then contributes to plasma development, with cathode injection having a delayed and secondary role. Continuous field emission at the streamer tip contributes to filament growth and propagation. This model can adequately explain almost all of the experimentally observed features, including dendritic structures and fluctuations in the prebreakdown current. Two-dimensional, time-dependent simulations have been carried out based on a continuum model for water, though the results are quite general. Monte Carlo simulations provide the relevant transport parameters for our model. Our quantitative predictions match the available data quite well, including the breakdown delay times and observed optical emission

    DFTB+, a software package for efficient approximate density functional theory based atomistic simulations

    Get PDF
    DFTB+ is a versatile community developed open source software package offering fast and efficient methods for carrying out atomistic quantum mechanical simulations. By implementing various methods approximating density functional theory (DFT), such as the density functional based tight binding (DFTB) and the extended tight binding method, it enables simulations of large systems and long timescales with reasonable accuracy while being considerably faster for typical simulations than the respective ab initio methods. Based on the DFTB framework, it additionally offers approximated versions of various DFT extensions including hybrid functionals, time dependent formalism for treating excited systems, electron transport using non-equilibrium Green’s functions, and many more. DFTB+ can be used as a user-friendly standalone application in addition to being embedded into other software packages as a library or acting as a calculation-server accessed by socket communication. We give an overview of the recently developed capabilities of the DFTB+ code, demonstrating with a few use case examples, discuss the strengths and weaknesses of the various features, and also discuss on-going developments and possible future perspectives

    Evaluación de tres dosis de potasio en la producción de lechuga (Lactuca sativa L. var. Crispa) bajo el sistema hidropónico recirculante NTF bajo invernadero

    Get PDF
    Three doses of potassium were evaluated in the production of lettuce (Lactuca sativa L. var. Crispa), under the recirculable NFT hydroponic system in the greenhouse of the Department of Horticulture of the ESPOCH. A completely randomized block design was used with three treatments and three replications. The doses evaluated were: low dose (LD) with 224,33 ppm, medium dose (MD) with 470,00 ppm, and high dose (HD) with 716,67 ppm. Evaluated parameters were: potassium content in leaves and root, fresh weights of the aerial part and root, yield per net plot and hectare. The economic analysis was carried out according to the relation benefit/cost. The best results for most of the parameters evaluated were obtained with the low dose (LD), obtaining fresh weights of the aerial part and root of 193,01 and 36,65 g respectively. It has a yield per net plot of 2,04 kilograms and per hectare of 15338,75 kilograms, and the highest cost benefit with 4,63 dollars equivalent to 362,75%. On the other hand, the highest content of potassium in leaves and root up to 40 days after transplant (DAT) was obtained with the medium dose (MD) with 5,13 and 6,00% of total potassium, respectively. In all treatments, maintaining turgor in the plants throughout the cycle is very important. From the agronomic and economic point of view, the use a nutritive solution containing 224,33 ppm of potassium was recommended
    • …
    corecore