scholarly journals A Weather-Driven Model for Predicting Infections of Grapevines by Sporangia of Plasmopara viticola

2021 ◽  
Vol 12 ◽  
Author(s):  
Chiara Brischetto ◽  
Federica Bove ◽  
Giorgia Fedele ◽  
Vittorio Rossi
Keyword(s):  
High Risk ◽  
Downy Mildew ◽  
Environmental Conditions ◽  
Posterior Probability ◽  
Prior Probability ◽  
Mechanistic Model ◽  
Plasmopara Viticola ◽  
Low Risk ◽  
Secondary Infections

A mechanistic model was developed to predict secondary infections of Plasmopara viticola and their severity as influenced by environmental conditions; the model incorporates the processes of sporangia production and survival on downy mildew (DM) lesions, dispersal and deposition, and infection. The model was evaluated against observed data (collected in a 3-year vineyard) for its accuracy to predict periods with no sporangia (i.e., for negative prognosis) or with peaks of sporangia, so that growers can identify periods with no/low risk or high risk. The model increased the probability to correctly predict no sporangia [P(P−O−) = 0.67] by two times compared to the prior probability, with fewer than 3% of the total sporangia found in the vineyard being sampled when not predicted by the model. The model also correctly predicted peaks of sporangia, with only 1 of 40 peaks unpredicted. When evaluated for the negative prognosis of infection periods, the model showed a posterior probability for infection not to occur when not predicted P(P−O−) = 0.87 with only 9 of 108 real infections not predicted; these unpredicted infections were mild, accounting for only 4.4% of the total DM lesions observed in the vineyard. In conclusion, the model was able to identify periods in which the DM risk was nil or very low. It may, therefore, help growers avoid fungicide sprays when not needed and lengthen the interval between two sprays, i.e., it will help growers move from calendar-based to risk-based fungicide schedules for the control of P. viticola in vineyards.

scholarly journals Evaluation of a Disease Warning System for Downy Mildew of Grapes

Plant Disease ◽  
2000 ◽  
Vol 84 (5) ◽  
pp. 549-554 ◽  
Author(s):  
L. V. Madden ◽  
M. A. Ellis ◽  
N. Lalancette ◽  
G. Hughes ◽  
L. L. Wilson
Keyword(s):  
Linear Model ◽  
Downy Mildew ◽  
Environmental Conditions ◽  
Generalized Linear Model ◽  
Disease Incidence ◽  
Warning System ◽  
Plasmopara Viticola ◽  
Effective Control ◽  
Subsequent Infection ◽  
Grape Downy Mildew

An electronic warning system for grape downy mildew— based on models for the infection of leaves of Vitis lambrusca, production of sporangia by Plasmopara viticola in lesions, and sporangial survival—was tested over 7 years in Ohio. Grapevines were sprayed with metalaxyl plus mancozeb (Ridomil MZ58) when the warning system indicated that environmental conditions were favorable for sporulation and subsequent infection. Over the 7 years, plots were sprayed from one to four times according to the warning system, and from four to 10 times according to the standard calendar-based schedule (depending on the date of the initiation of the experiment). The warning system resulted in yearly reductions of one to six sprays (with median of three sprays). Disease incidence (i.e., proportion of leaves with symptoms) in unsprayed plots at the end of the season ranged from 0 to 86%, with a median of 68%. Incidence generally was very similar for the warning-system and standard-schedule treatments (median of 7% of the leaves with symptoms), and both of these incidence values were significantly lower (P < 0.05) than that found for the unsprayed control, based on a generalized-linear-model analysis. Simplifications of the disease warning system, where sprays were applied based only on the infection or sporulation components of the system, were also effective in controlling the disease, although more fungicide applications sometimes were applied. Effective control of downy mildew, therefore, can be achieved with the use of the warning system with fewer sprays than a with a standard schedule.

scholarly journals Simulation of potential epidemics of downy mildew of grapevine in different scenarios of disease conduciveness

2020 ◽  
Vol 158 (3) ◽  
pp. 599-614
Author(s):  
Federica Bove ◽  
Serge Savary ◽  
Laetitia Willocquet ◽  
Vittorio Rossi
Keyword(s):  
Climate Change ◽  
Downy Mildew ◽  
Environmental Conditions ◽  
Growth And Development ◽  
Simulation Experiment ◽  
Quantitative Information ◽  
Climate Scenarios ◽  
Grapevine Downy Mildew ◽  
Secondary Infections ◽  
Temperature Factors

Abstract The parameterisation process of a previously developed modelling structure of the grapevine-downy mildew pathosystem is described. The model incorporates primary and secondary infections, host crop growth and development, along with a linkage between disease on foliage and disease on clusters. This process-based model was developed with a main objective of understanding the behaviour of the pathosystem under different, variable, environmental conditions, or under climate change. Six scenarios of disease conduciveness were developed in order to capture the range of environmental conditions under which potential downy mildew of grapevine epidemics can develop. These climate scenarios were based on moisture and temperature factors. The scenarios were translated into vectors of parameters for primary and secondary infections in the model. Model testing was performed in three steps: (i) an analysis of potential epidemics was conducted from the literature on grapevine downy mildew in order to delineate the behaviour of the pathosystem under different scenarios; (ii) a simulation experiment was conducted to investigate the response of the model to different patterns of environmental conditions, corresponding to six scenarios of disease conduciveness; and (iii) expected and simulated epidemics under these scenarios were compared. In scenarios, the model mobilised existing quantitative information on downy mildew of grapevine and generated outputs that are congruent with expected patterns of potential epidemic. This study indicates that the model is a reliable tool for simulating accurate and robust potential epidemics of downy mildew of grapevine in a scenario analysis. This can have many applications, such as the understanding of the behaviour of the pathosystem under climate change or when partial host resistance is involved.

scholarly journals Analysis of Climatic Risk Favorability of Grapevine Fungal Disease Occurrence for Santa Teresa, Espírito Santo State, Brazil

2019 ◽  
Vol 11 (14) ◽  
pp. 121
Author(s):  
Lucas Alves Rodrigues ◽  
Evandro Chaves de Oliveira ◽  
Maria Emília Borges Alves ◽  
Ramon Amaro de Sales ◽  
Jadier de Oliveira Cunha Junior ◽  
...  
Keyword(s):  
High Risk ◽  
Downy Mildew ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Plasmopara Viticola ◽  
The State ◽  
Fungal Diseases ◽  
Soil Conditions ◽  
Climatic Risk ◽  
Disease Occurrence

The State of Esp&iacute;rito Santo, Brazil, has micro-regions with different climatic and soil conditions, which promote grapevine cultivation vine in several municipalities. However, the grape production process is strongly threatened by foliar fungal diseases, and its control increases the cost of production significantly. In turn, the use of models of prediction of disease occurrence allows the identification of regions with climatic risk potential for grapevine. Hence, the objective of this work was to analyze the agro-climatic favorability of climatic risk for occurrence of fungal diseases of downy mildew (Plasmopara viticola) and Botrytis cinerea on the grapevine for the municipality of Santa Teresa, in the state of Esp&iacute;rito Santo. Predictive models of favorability of downy mildew and B. cinerea were used. The number of sprayings was determined by the calendar system and by the rainfall system, according to the length of the cycle. Therefore, a series of meteorological data from 2007 to 2016 was used. The results showed that the frequency of days with low risk of mildew was 2%, medium risk 5%, high risk 93%. For B. cinerea, these values were 32%, 68%, and 0%, with low, medium and high risk, respectively. The number of required sprayings, according to the weather conditions, was lower than the number of sprayings recommended by the calendar system. The relationship between the risk of occurrence of the evaluated diseases showed a higher agro-meteorological favorability of occurrence of mildew in relation to B. cinerea.

Papillary Thyroid Carcinoma: How Radical Lymphadenectomy Should be Performed?

Swiss Surgery ◽  
2003 ◽  
Vol 9 (2) ◽  
pp. 63-68
Author(s):  
Schweizer ◽  
Seifert ◽  
Gemsenjäger
Keyword(s):  
High Risk ◽  
Papillary Thyroid Carcinoma ◽  
Thyroid Carcinoma ◽  
Low Risk ◽  
Papillary Thyroid ◽  
Sentinel Nodes ◽  
Fand Sich ◽  
Radical Lymphadenectomy ◽  
N Status

Fragestellung: Die Bedeutung von Lymphknotenbefall bei papillärem Schilddrüsenkarzinom und die optimale Lymphknotenchirurgie werden kontrovers beurteilt. Methodik: Retrospektive Langzeitstudie eines Operateurs (n = 159), prospektive Dokumentation, Nachkontrolle 1-27 (x = 8) Jahre, Untersuchung mit Bezug auf Lymphknotenbefall. Resultate: Staging. Bei 42 Patienten wurde wegen makroskopischem Lymphknotenbefall (cN1) eine therapeutische Lymphadenektomie durchgeführt, mit pN1 Status bei 41 (98%) Patienten. Unter 117 Patienten ohne Anhalt für Lymphknotenbefall (cN0) fand sich okkulter Befall bei 5/29 (17%) Patienten mit elektiver (prophylaktischer) Lymphadenektomie, und bei 2/88 (2.3%) Patienten ohne Lymphadenektomie (metachroner Befall) (p < 0.005). Lymphknotenrezidive traten (1-5 Jahre nach kurativer Primärtherapie) bei 5/42 (12%) pN1 und bei 3/114 (2.6%) cN0, pN0 Tumoren auf (p = 0009). Das 20-Jahres-Überleben war bei TNM I + II (low risk) Patienten 100%, d.h. unabhängig vom N Status; pN1 vs. pN0, cN0 beeinflusste das Überleben ungünstig bei high risk (>= 45-jährige) Patienten (50% vs. 86%; p = 0.03). Diskussion: Der makroskopische intraoperative Lymphknotenbefund (cN) hat Bedeutung: - Befall ist meistens richtig positiv (pN1) und erfordert eine ausreichend radikale, d.h. systematische, kompartiment-orientierte Lymphadenektomie (Mikrodissektion) zur Verhütung von - kurablem oder gefährlichem - Rezidiv. - Okkulter Befall bei unauffälligen Lymphknoten führt selten zum klinischen Rezidiv und beeinflusst das Überleben nicht. Wir empfehlen eine weniger radikale (sampling), nur zentrale prophylaktische Lymphadenektomie, ohne Risiko von chirurgischer Morbidität. Ein empfindlicherer Nachweis von okkultem Befund (Immunhistochemie, Schnellschnitt von sampling Gewebe oder sentinel nodes) erscheint nicht rational. Bei pN0, cN0 Befund kommen Verzicht auf 131I Prophylaxe und eine weniger intensive Nachsorge in Frage.

Individuals at high risk for suicide are categorically distinct from those at low risk.

2017 ◽  
Vol 29 (4) ◽  
pp. 382-393 ◽  
Author(s):  
Tracy K. Witte ◽  
Jill M. Holm-Denoma ◽  
Kelly L. Zuromski ◽  
Jami M. Gauthier ◽  
John Ruscio
Keyword(s):  
High Risk ◽  
Low Risk

A Critical Overview of Systematic Reviews of Chemotherapy for Advanced and Locally Advanced Pancreatic Cancer using both AMSTAR2 and ROBIS as Quality Assessment Tools

2020 ◽  
Vol 15 ◽  
Author(s):  
Amit Dang ◽  
Surendar Chidirala ◽  
Prashanth Veeranki ◽  
BN Vallish
Keyword(s):  
Pancreatic Cancer ◽  
High Risk ◽  
Systematic Reviews ◽  
Locally Advanced ◽  
Advanced Pancreatic Cancer ◽  
Risk Of Bias ◽  
Low Risk ◽  
Locally Advanced Pancreatic Cancer ◽  
Grade 3 ◽  
Critical Overview

Background: We performed a critical overview of published systematic reviews (SRs) of chemotherapy for advanced and locally advanced pancreatic cancer, and evaluated their quality using AMSTAR2 and ROBIS tools. Materials and Methods: PubMed and Cochrane Central Library were searched for SRs on 13th June 2020. SRs with metaanalysis which included only randomized controlled trials and that had assessed chemotherapy as one of the treatment arms were included. The outcome measures, which were looked into, were progression-free survival (PFS), overall survival (OS), and adverse events (AEs) of grade 3 or above. Two reviewers independently assessed all the SRs with both ROBIS and AMSTAR2. Results: Out of the 1,879 identified records, 26 SRs were included for the overview. Most SRs had concluded that gemcitabine-based combination regimes, prolonged OS and PFS, but increased the incidence of grade 3-4 toxicities, when compared to gemcitabine monotherapy, but survival benefits were not consistent when gemcitabine was combined with molecular targeted agents. As per ROBIS, 24/26 SRs had high risk of bias, with only 1/26 SR having low risk of bias. As per AMSTAR2, 25/26 SRs had critically low, and 1/26 SR had low, confidence in the results. The study which scored ‘low’ risk of bias in ROBIS scored ‘low confidence in results’ in AMSTAR2. The inter-rater reliability for scoring the overall confidence in the SRs with AMSTAR2 and the overall domain in ROBIS was substantial; ROBIS: kappa=0.785, SEM=0.207, p<0.001; AMSTAR2: kappa=0.649, SEM=0.323, p<0.001. Conclusion: Gemcitabine-based combination regimens can prolong OS and PFS but also worsen AEs when compared to gemcitabine monotherapy. The included SRs have an overall low methodological quality and high risk of bias as per AMSTAR2 and ROBIS respectively.

scholarly journals Content of trans-resveratrol in leaves and berries of interspecific grapevine (Vitis sp.) varieties

2009 ◽  
Vol 26 (Special Issue) ◽  
pp. S13-S17 ◽  
Author(s):  
P. Bábíková ◽  
N. Vrchotová ◽  
J. Tříska ◽  
M. Kyseláková
Keyword(s):  
Powdery Mildew ◽  
Downy Mildew ◽  
Plasmopara Viticola ◽  
Fungal Diseases ◽  
Uncinula Necator ◽  
Botryotinia Fuckeliana

The aim of this project was to study changes in the content of <i>trans</i>-resveratrol in berries and leaves of grapevine (<i>Vitis</i> sp.) infested by fungal diseases, especially by <i>Botryotinia fuckeliana</i> Whetzel, called as grey mildew, <i>Plasmopara viticola</i> (Berk. & M.A. Curtis) Berl & De Toni, called downy mildew and <i>Uncinula necator</i> (Schw.) Burr, called powdery mildew. In our experiments two white and two blue varieties were used. Contents of <i>trans</i>-resveratrol were determined in healthy and infested leaves and in healthy berries. Infested leaves of white varieties contained more <i>trans</i>-resveratrol than those of blue varieties. The content of <i>trans</i>-resveratrol in berries was lower than that in leaves.

scholarly journals Proposal for the use of echocardiography in bloodstream infections due to different streptococcal species

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sandra Chamat-Hedemand ◽  
Niels Eske Bruun ◽  
Lauge Østergaard ◽  
Magnus Arpi ◽  
Emil Fosbøl ◽  
...  
Keyword(s):  
Risk Factors ◽  
Risk Factor ◽  
High Risk ◽  
Blood Culture ◽  
Positive Blood Culture ◽  
Bloodstream Infections ◽  
Low Risk ◽  
Moderate Risk ◽  
Streptococcal Species ◽  
Very High

Abstract Background Infective endocarditis (IE) is diagnosed in 7–8% of streptococcal bloodstream infections (BSIs), yet it is unclear when to perform transthoracic (TTE) and transoesophageal echocardiography (TOE) according to different streptococcal species. The aim of this sub-study was to propose a flowchart for the use of echocardiography in streptococcal BSIs. Methods In a population-based setup, we investigated all patients admitted with streptococcal BSIs and crosslinked data with nationwide registries to identify comorbidities and concomitant hospitalization with IE. Streptococcal species were divided in four groups based on the crude risk of being diagnosed with IE (low-risk < 3%, moderate-risk 3–10%, high-risk 10–30% and very high-risk > 30%). Based on number of positive blood culture (BC) bottles and IE risk factors (prosthetic valve, previous IE, native valve disease, and cardiac device), we further stratified cases according to probability of concomitant IE diagnosis to create a flowchart suggesting TTE plus TOE (IE > 10%), TTE (IE 3–10%), or “wait & see” (IE < 3%). Results We included 6393 cases with streptococcal BSIs (mean age 68.1 years [SD 16.2], 52.8% men). BSIs with low-risk streptococci (S. pneumoniae, S. pyogenes, S. intermedius) are not initially recommended echocardiography, unless they have ≥3 positive BC bottles and an IE risk factor. Moderate-risk streptococci (S. agalactiae, S. anginosus, S. constellatus, S. dysgalactiae, S. salivarius, S. thermophilus) are guided to “wait & see” strategy if they neither have a risk factor nor ≥3 positive BC bottles, while a TTE is recommended if they have either ≥3 positive BC bottles or a risk factor. Further, a TTE and TOE are recommended if they present with both. High-risk streptococci (S. mitis/oralis, S. parasanguinis, G. adiacens) are directed to a TTE if they neither have a risk factor nor ≥3 positive BC bottles, but to TTE and TOE if they have either ≥3 positive BC bottles or a risk factor. Very high-risk streptococci (S. gordonii, S. gallolyticus, S. mutans, S. sanguinis) are guided directly to TTE and TOE due to a high baseline IE prevalence. Conclusion In addition to the clinical picture, this flowchart based on streptococcal species, number of positive blood culture bottles, and risk factors, can help guide the use of echocardiography in streptococcal bloodstream infections. Since echocardiography results are not available the findings should be confirmed prospectively with the use of systematic echocardiography.

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