Effect of Overhead Spray and Brush Roller Treatment on the Survival of Pectobacterium and Salmonella on Tomato Surfaces

2015 ◽  
Vol 78 (1) ◽  
pp. 51-56 ◽  
Author(s):  
ALINA N. BALAGUERO ◽  
ASWATHY SREEDHARAN ◽  
KEITH R. SCHNEIDER
Keyword(s):  
Relative Humidity ◽  
Plant Pathogen ◽  
Tomato Fruit ◽  
Soft Rot ◽  
Human Pathogen ◽  
Physical Damage ◽  
Tomato Quality ◽  
Negative Effect ◽  
Survival And Growth ◽  
Salmonella Survival

Overhead spray and brush roller (OSBR) treatment has been shown to remove significantly more Salmonella from tomato surfaces than flume treatment. However, OSBR is not widely used in tomato packing facilities compared with other commodities, and little is known about whether brushing causes microabrasions or other physical damage. Bacteria such as Pectobacterium, a soft rot–producing plant pathogen, and Salmonella, a human pathogen, show increased survival and growth on damaged tomato surfaces. This study evaluated whether OSBR treatment had a negative effect on the safety and/or marketability of tomatoes by examining its effect on Pectobacterium and Salmonella survival. Pectobacterium survival was evaluated on inoculated tomatoes that were OSBR treated with water or sanitizer (100 ppm of NaOCl, 5 ppm of ClO2, or 80 ppm of peracetic acid). A 15-s OSBR treatment using water or sanitizer achieved a 3-log CFU/ml reduction in Pectobacterium levels. Survival of Pectobacterium and Salmonella on OSBR-treated, untreated, and puncture-wounded tomatoes stored at 25°C and 75 to 85% relative humidity for 7 days was also assessed. Both Pectobacterium and Salmonella populations declined rapidly on OSBR-treated and untreated tomatoes, indicating that brushing does not damage tomato fruit to the extent of promoting better pathogen survival. In contrast, the survival of both organisms was significantly (P ≤ 0.05) higher on artificially wounded fruit. These results indicate that OSBR treatment does not increase the survival and growth of Pectobacterium or Salmonella on tomato surfaces and that it is effective in reducing Pectobacterium levels on the surface of inoculated tomatoes. These results suggest that, if used properly, an OSBR system in packinghouses is effective in removing surface contamination and does not affect tomato quality or safety.

scholarly journals Isolated individuals and groups show opposite preferences toward humidity

2018 ◽  
Author(s):  
Mariano Calvo Martín ◽  
Stamatios C. Nicolis ◽  
Isaac Planas-Sitjà ◽  
Jean-Christophe de Biseau ◽  
Jean-Louis Deneubourg
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Group Level ◽  
Individual Level ◽  
Negative Effect ◽  
Multi Level ◽  
The Individual ◽  
Shed Light ◽  
Selection Of

AbstractCockroaches, like most social arthropods, are led to choose collectively among different alternative resting places. These decisions are modulated by different factors, such as environmental conditions (temperature, relative humidity) and sociality (groups size, nature of communications). The aim of this study is to establish the interplay between environmental conditions and the modulation of the interactions between individuals within a group leading to an inversion of preferences. We show that the preferences of isolated cockroaches and groups of 16 individuals, on the selection of the relative humidity of a shelter are inversed and shed light on the mechanisms involved. We suggest that the relative humidity has a multi-level influence on cockroaches, manifested as an attractant effect at the individual level and as a negative effect at the group level, modulating the interactions.

scholarly journals First Report of Sclerotinia Stem Rot and Watery Soft Rot Caused by Sclerotinia sclerotiorum on Sand Rocket (Diplotaxis tenuifolia) in Italy

Plant Disease ◽  
2005 ◽  
Vol 89 (11) ◽  
pp. 1241-1241 ◽  
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino
Keyword(s):  
Relative Humidity ◽  
Sclerotinia Sclerotiorum ◽  
Severe Disease ◽  
Soil Surface ◽  
Soft Rot ◽  
Sclerotinia Stem Rot ◽  
First Report ◽  
Initial Symptoms ◽  
Stem Necrosis ◽  
White Mycelium

Several species of Diplotaxis (D. tenuifolia, D. erucoides, and D. muralis), known as wild or sand rocket, are widely cultivated in Italy. Rocket is used in Mediterranean cuisine as salad, a component of packaged salad products, and as a garnish for food. In winter 2003, a severe disease was observed on D. tenuifolia grown in unheated glasshouses on commercial farms near Albenga in northern Italy. Initial symptoms included stem necrosis at the soil level and darkening of leaves. As stem necrosis progressed, infected plants wilted and died. Wilt, characterized by the presence of soft and watery tissues, occurred within a few days on young plants. The disease was extremely severe in the presence of high relative humidity and mild temperature (15°C). Necrotic tissues became covered with white mycelium that produced dark sclerotia. Diseased stem tissue was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 ppm streptomycin sulfate. Sclerotinia sclerotiorum (1) was consistently recovered from infected stem pieces. Sclerotia observed on infected plants measured 1.23 to 3.00 × 1.40 to 5.38 mm (average 2.10 × 2.85 mm). Sclerotia produced on PDA measured 1.00 to 4.28 × 1.00 to 6.01 mm (average 2.38 × 3.23 mm). Pathogenicity of three isolates obtained from infected plants was confirmed by inoculating 30-day-old plants of D. tenuifolia grown in 18-cm-diameter pots in a glasshouse. Inoculum, 2 g per pot of wheat kernels infested with mycelium and sclerotia of each isolate, was placed on the soil surface around the base of each plant. Three replicates of five pots each were used per isolate. Noninoculated plants served as controls. The inoculation trial was repeated once. All plants were kept at temperatures ranging between 10 and 26°C (average 15°C) with an average relative humidity of 80% and were watered as needed. Inoculated plants developed symptoms of leaf yellowing within 12 days, soon followed by the appearance of white mycelium and sclerotia, and eventually wilted. Control plants remained symptomless. S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of infection of D. tenuifolia by S. sclerotiorum in Italy as well as worldwide. The disease currently has been observed in the Liguria Region but not yet in other areas where sand rocket is cultivated. The economic importance of this disease for the crop can be considered medium at the moment, but is expected to increase in the future. Reference: (1) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 75, 1949.

scholarly journals Fauna asociada a la pesquería de Arca Zebra (Mollusca Bivalvia: Arcidae) en Venezuela

2018 ◽  
Vol 47 (1) ◽  
Author(s):  
Roberto Díaz-Fermín ◽  
Vanessa Acosta-Balbás
Keyword(s):  
Community Structure ◽  
New Record ◽  
Diversity Index ◽  
Economic Viability ◽  
Total Biomass ◽  
Total Abundance ◽  
Physical Damage ◽  
Negative Effect ◽  
Fishing Resources ◽  
Pinctada Imbricata

Arca zebra, constitutes one of the fishing resources with the greatest economic impact in northeastern Venezuela, since it forms banks of commercial importance. During a period of nine months (May 2010-August2011) the community structure of the organisms from the trawling fishery carried out by the fishermen of the area was identified, quantified and described. The biomass and abundance of the different groups were estimated to perform Abundance-Biomass Comparison Curves (ABC) with the objective of determining the degree of affectation by the trawling activity. A total of3 249 organisms belonging to 130 species were grouped in five Phyla: Mollusca, Annelida, Arthropoda, Echinodermata and Chordata. The Sanders' diversity index was 122.9 with mollusks (70.87) and polychaetes (29.91) as the most diverse taxa. Mollusks had the highest abundance followed by polychaetes, crustaceans, echinoderms and ascidians. Mollusks and echinoderms made the largest contribution to total biomass. The most frequent species were: Mithraculus forceps, Phallucia nigra, Echinometra lucunter, Eunice rubra and Pinctada imbricata. The microgastropods Triphora melanura is recognized as a new record for the area and the polychaete Oenone fulgida, for Venezuela. The ABC curve showed that total abundance of organisms was above total biomass, suggesting that the fishery of Arca zebra has a negative effect on most groups of organisms, mainly on echinoderms, since many of them suffer strong physical damage at the time of extraction, therefore, there is a need to modify the trawl nets, increasing the mesh opening, butwithout endangering the economic viability of the fishery.

Absolute humidity of atmospheric air and COVID-19

2021 ◽  
pp. 8-24
Author(s):  
Vladimir Vasilievich Krivosheev ◽  
Artem Igorevich Stolyarov ◽  
Aleksandr Aleksandrovich Semenov
Keyword(s):  
Relative Humidity ◽  
Absolute Humidity ◽  
Atmospheric Parameter ◽  
Natural Factor ◽  
Incidence And Mortality ◽  
Optimal Value ◽  
Negative Effect ◽  
Northern Territories ◽  
High Degree ◽  
The Impact

Today COVID-19 is number one global point of focus. Therefore, study of the effects of environmental conditions, in which exist pandemic subjects — people and viruses, on pandemic dynamics and results is extremely important. The authors made a correlation analysis of dependence between incidence/mortality of population and absolute and relative humidity in 73 countries and regions on different continents of the Earth. The methodology developed defines how and in what periods of time the environmental factors effect on human incidence and mortality, how strongly particular atmospheric parameter affects the process of infection and disease flow. The undertaken calculations allowed to prove that the absolute humidity is one of the dominant natural factor which influences on pandemic COVID-19 and other infectious diseases dynamics. The growth of absolute air humidity can have both positive and negative effect on incidence and mortality of population while the effect’s character depends on absolute humidity’s own level and other atmospheric parameters. Correlation of absolute and relative humidity with incidence/mortality at the same time can be different in value or sign. Existing regulations at the federal level in Russian Federation are established without taking into account the minimum allowable and physiologically optimal value of absolute humidity, and need corrections. The question of the impact of absolute humidity is of great importance for northern territories, where most of the year the value of absolute humidity is less than the minimum allowed. The achieved results show high degree of the impact of absolute humidity on incidence and mortality of population due to COVID-19 and contribute to better understanding of pandemic peaks cyclicality and conscious forecasting of start of periods of the most dangerous epidemiological reality.

Survival of Salmonella on Chamomile, Peppermint, and Green Tea during Storage and Subsequent Survival or Growth following Tea Brewing

2015 ◽  
Vol 78 (4) ◽  
pp. 661-667 ◽  
Author(s):  
SUSANNE E. KELLER ◽  
CHRISTINA N. STAM ◽  
DANA R. GRADL ◽  
ZHENGZAI CHEN ◽  
EMILY L. LARKIN ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Thermal Resistance ◽  
Green Tea ◽  
Storage Conditions ◽  
Tea Leaves ◽  
Brewing Process ◽  
Green Tea Leaves ◽  
Survival And Growth ◽  
D Values ◽  
Chamomile Flowers

The survival of Salmonella on dried chamomile flowers, peppermint leaves, and green tea leaves stored under different conditions was examined. Survival and growth of Salmonella was also assessed after subsequent brewing using dried inoculated teas. A Salmonella enterica serovar cocktail was inoculated onto different dried tea leaves or flowers to give starting populations of approximately 10 log CFU/g. The inoculum was allowed to dry (at ambient temperature for 24 h) onto the dried leaves or flowers prior to storage under 25 and 35°C at low (<30% relative humidity [RH]) and high (>90% RH) humidity levels. Under the four storage conditions tested, survival followed the order 25°C with low RH > 35°C with low RH > 25° C with high RH > 35°C with high RH. Salmonella losses at 25°C with low RH occurred primarily during drying, after which populations showed little decline over 6 months. In contrast, Salmonella decreased below detection after 45 days at 35°C and high RH in all teas tested. The thermal resistance of Salmonella was assessed at 55°C immediately after inoculation of tea leaves or flowers, after drying (24 h) onto tea leaves or flowers, and after 28 days of storage at 25°C with low RH. All conditions resulted in similar D-values (2.78 ± 0.12, 3.04 ± 0.07, and 2.78 ± 0.56, at 0 h, 24 h, and 28 days, respectively), indicating thermal resistance of Salmonella in brewed tea did not change after desiccation and 28 days of storage. In addition, all brewed teas tested supported the growth of Salmonella. If Salmonella survives after storage, it may also survive and grow after a home brewing process.

Non-Repair Dynamically Balanced Device of Wheel Set in Vehicles

2012 ◽  
Vol 510 ◽  
pp. 431-436
Author(s):  
Chao Liu ◽  
Chao Zou ◽  
Dong Ju Wang ◽  
Zai Lin Ge
Keyword(s):  
Mass Distribution ◽  
High Speed ◽  
Dynamic Balance ◽  
Mass Center ◽  
Physical Damage ◽  
Limited Effect ◽  
Negative Effect ◽  
Weight Method ◽  
Economy Benefit

In order to make the mass distribution of the wheel set symmetrical about the axis of the wheel axle, which is able to remove the periodical exciter source and many consequences coming from it, including having negative effect on the stationarity and stability during the running of the train, shortening the lifetime of the wheels, bearings and many other parts of the train, design a set of balanced device to regulate the mass center of the wheel set. The set of device collects data by relevant detection devices in order to find the mass distribution condition, and then regulate the circumferential positions of the objects with a certain mass in the tapered groove which can make the mass distribution of the wheel set symmetrical about the axis of the wheel axle. The device has many advantages, such as simplicity, high precision, excellent regulating effects, and, at the same time, conquers the disadvantages of many other ways. For the time being, the means to solve the problem are mainly Adding Weight Method and Removing Weight Method, which both cause physical damage to the wheel. Furthermore, these two methods have a lot of disadvantages, such as low stability, limited effect, limited repairing numbers and high labor strength. The device not only conquers these disadvantages of the two methods, but also has many advantages, and in the future, it can be automatically controlled by microcomputers. Wheel sets are very essential to the running of the train, whose quality has outstanding effect on the safety and quality of the running of the train, especially in the condition that trains run faster and faster, which requires wheel sets to meet higher standards on dynamic balance, especially for new high-speed bogie. Thus, the device has a large economy benefit and society benefit.

Relative humidity and temperature modify the mechanical properties of isolated tomato fruit cuticles

2005 ◽  
Vol 92 (3) ◽  
pp. 462-468 ◽  
Author(s):  
A. J. Matas ◽  
G. Lopez-Casado ◽  
J. Cuartero ◽  
A. Heredia
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Tomato Fruit

scholarly journals Role of Major Weather Parameters in the Production of Black Pepper in Kerala

2021 ◽  
pp. 259-267
Author(s):  
Nayana S. Nair ◽  
M. Thilagavathi ◽  
M. Prahadeeswaran ◽  
M. R. Duraisamy
Keyword(s):  
Relative Humidity ◽  
Secondary Data ◽  
Black Pepper ◽  
Total Production ◽  
Farming Practices ◽  
Unit Increase ◽  
Indian State ◽  
Negative Effect ◽  
Weather Parameters

Aim: The present study intends to analyse the influence of weather parameters on the production of black pepper in six major pepper producing districts of Kerala, the Indian state which contributes a considerable share to national spice exports. Methodology: This research is based on secondary data which is limited to six major black pepper producing districts of Kerala which were chosen based on their contribution to total production of the state 2020. More than 50% of the production was from Idukki district followed by Wayanad (8%), and around 3 to 3.5% from Kannur, Kasargod, Kottayam and Kollam districts respectively. Annual precipitation, Relative humidity, Maximum and Minimum temperatures were the parameters taken into consideration along with production data of over 15 years (2005-2019) which was then subjected to regression analysis using panel data. Results: According to the results, significant reduction in production by 2.52% and 1.88% was recorded for unit increase maximum (P= 0.047) and minimum temperature (P=0.03) respectively. Likewise, unit rise in relative humidity and rainfall was responsible for decrease In production by 1.1%, and 0.07% respectively though they were reported to be insignificant. Conclusion: From the present study, it could be concluded that maximum and minimum temperatures were found to be significant in affecting the production of black pepper. However the negative regression coefficients obtained for other factors like rainfall and relative humidity implied its negative effect on production. In order to combat these variations, there is therefore, the need to create awareness to farmers in India on the need to adopt best farming practices in order to improve yield of this important crop.

scholarly journals Controlling Relative Humidity in Modified Atmosphere Packages of Tomato Fruit

HortScience ◽  
1992 ◽  
Vol 27 (4) ◽  
pp. 336-339 ◽  
Author(s):  
Ahmad Shirazi ◽  
Arthur C. Cameron
Keyword(s):  
Relative Humidity ◽  
Lycopersicon Esculentum ◽  
Sorption Isotherm ◽  
Control Method ◽  
Tomato Fruit ◽  
Storage Life ◽  
Simple System ◽  
Modified Atmosphere ◽  
Humidity Control ◽  
Fruit Mass

The feasibility of controlling relative humidity in modified atmosphere packages using compounds possessing Type III sorption isotherm behavior was studied. Ten grams each of dry sorbitol, xylitol, NaCl, KCl, or CaCl2 sealed with one maturegreen tomato (Lycopersicon esculentum L.) fruit at 20C in simulated packages for 48 days resulted in stable relative humidities of ≈75%, 80%, 75%, 85%, and 35%, respectively. Relative humidity was a function of the ratio of chemical to fruit mass. Relative humidities within control packages were in the range of 96% to 100% throughout the experiments. A simple system that uses spunbonded polyethylene pouches for the application of this humidity control method to packages is described. The storage life of packaged red-ripe tomato fruit at 20C was extended from 5 days using no pouch to 15 to 17 days with a pouch containing NaCl, mainly by retardation of surface mold development.

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