Variability of Virus Attachment Patterns to Butterhead Lettuce

2005 ◽  
Vol 68 (10) ◽  
pp. 2112-2117 ◽  
Author(s):  
EVERARDO VEGA ◽  
JEANON SMITH ◽  
JAY GARLAND ◽  
ANABELLE MATOS ◽  
SURESH D. PILLAI

Enteric viruses account for most foodborne illness in the United States. The objective of this study was to determine whether the isoelectric point (pI) of viruses such as feline calicivirus (FCV), echovirus 11, and bacteriophages φX174 and MS2 had any effect on their attachment to butterhead lettuce. The adsorption of virus particles to the lettuce was variable. Bacteriophage MS2 was the only virus that fit the current Derjaguin-Landau-Verway-Overbeek model of virus attachment. Echovirus 11 had the highest affinity to lettuce surface. Echovirus 11 appeared to exhibit reversible attachment above its pI, whereas below its pI strong adsorption was observed. Adsorption of FCV was at its maximum above its pI. Bacteriophage φX174 exhibited the most complex adsorption pattern, with attachment occurring only at the pH extremes (pH 3.0 and 8.0). These results suggest the current model for virus adsorption to sediment does not adequately explain the attachment of virus to lettuce. Importantly, the results indirectly suggest that current sample processing methods to recover viruses from lettuce may differentially select for the recovery of only certain virus types.

2008 ◽  
Vol 71 (3) ◽  
pp. 522-529 ◽  
Author(s):  
EVERARDO VEGA ◽  
JAY GARLAND ◽  
SURESH D. PILLAI

Enteric viruses are key foodborne pathogens. The objective of this study was to compare the relative contributions of electrostatic and hydrophobic forces with the nonspecific attachment of virus to butterhead lettuce. The attachment of four viruses (echovirus 11, feline calicivirus [FCV], MS2, and φX174) was studied. Three different conditions, namely (i) 1% Tween 80, (ii) 1 M NaCl, and (iii) 1% Tween 80 with 1 M NaCl, were investigated to determine the role of hydrophobic, electrostatic, and combined hydrophobic and electrostatic forces, respectively. Attachment above the pI of FCV and echovirus 11 was reduced or eliminated in the presence of NaCl, indicating an electrostatic interaction between the animal viruses and lettuce. The bacteriophage φX174 was not significantly affected by any treatment, indicating a lack of electrostatic or hydro-phobic interactions between the lettuce and phage φX174. Overall, 1 M NaCl was the most effective treatment in desorbing viruses from the surface of lettuce at pH 7 and 8. The results imply that electrostatic forces play a major role in controlling virus adsorption to lettuce. The results indicate that 1 M NaCl solution would improve the recovery or elution of unenveloped viruses from lettuce.


Author(s):  
Candace Barnes ◽  
Rebecca Barber ◽  
Keith R. Schneider ◽  
Michelle D. Danyluk ◽  
Anita C. Wright ◽  
...  

Human norovirus (HuNoV) is the leading causative agent of foodborne outbreaks and is associated with the second most prevalent cause of waterborne infections in the United States. The goal of this research was to investigate the antiviral activity of chitosan microparticles (CM) against HuNoV GII.4 Sydney and its cultivable surrogate, Tulane virus (TuV), in suspensions mimicking fecally-contaminated water. CM was prepared by crosslinking chitosan molecules with sodium sulfate, and then its anti-noroviral activity was assessed using infectivity assay on TuV and RT-qPCR on TuV and HuNoV. A 3% CM suspension in PBS (pH 7.2) showed binding to TuV particles but with a negligible impact on virus infectivity (p>0.05). TuV and HuNoV suspended in fecal suspensions showed a 1.5-log10 reduction in genomic copies per ml following a 10-min contact time (p<0.05). Despite the negligible impact on viral infectivity, CM moderately binds to virus particles and helps purify environmental water by removing infectious virus particles. In this study, TuV served as a suitable surrogate for HuNoV by showing a similar log10 reduction in fecal suspension. Overall, the outcomes of thisresearch highlight the potential application of CM as a novel, natural treatment to minimize the spread of water-transmitted viral pathogens.


2014 ◽  
Vol 9 (3) ◽  
pp. 83
Author(s):  
Richard Hayman

A Review of: Cirasella, J., & Bowdoin, S. (2013). Just roll with it? Rolling volumes vs. discrete issues in open access library and information science journals. Journal of Librarianship and Scholarly Communication, 1(4). http://dx.doi.org/10.7710/2162-3309.1086 Abstract Objective – To understand the prevalence of, motivations for, and satisfaction with using a rolling-volume publishing model, as opposed to publishing discrete issues, across open access academic journals in library and information science. Design – A 12 question survey questionnaire. Setting – English-language, open access library and information science (LIS) journals published in the United States of America. Subjects – A total of 21 open access LIS journals identified via the Directory of Open Access Journals that were actively publishing, and that also met the authors’ standard of scholarliness, which they established by identifying a journal’s peer-review process or other evidence of rigorous review. Based on responses, 12 journals published using discrete issues, while 9 published as rolling volumes or as rolling volumes with some discrete issues. Methods – In late 2011, the study’s authors invited lead editors or primary journal contacts to complete the survey. Survey participants were asked to identify whether their journal published in discrete issues, rolling volumes, or rolling volumes with occasional discrete issues, with the latter two categories combined as one for ease of results analysis. Survey logic split respondents into two groups, either discrete-issue or rolling-volume. Respondents in both categories were posed similar sets of questions, with the key difference being that the questions directed at each category accounted for the publication model the journals themselves identified as using. Editors from both groups were asked about the reasons for using the publication model they identified for their journal: within the survey tool, authors provided 16 potential reasons for using a discrete-issue model, and 13 potential reasons for using a rolling-volume model. Respondents from both groups were asked to mark all reasons that applied for their respective journals. The survey also included questions about whether the journal had ever used the alternate publishing model, the editor’s satisfaction with their current model, and the likelihood of the journal switching to the alternate publishing model in the foreseeable future. Main Results – The authors collected complete responses from 21 of the original 29 journals invited to participate in the study, a response rate of 72%. For the 12 journals that identified as using discrete issues, ease of production workflow (91.7%), clear production deadlines (75.0%), and journal publicity and promotion (75.0%) were the three most common reasons for using a discrete-issue model. For the nine journals using rolling volumes, improved production workflow (77.8%), decreased dependence on production deadlines (77.8%), and increased speed of research dissemination (66.7%) were the three most common reasons cited for using a rolling-volume model. Findings show that overall satisfaction with a journal’s particular publication model was a common factor regardless of publishing model in use, though only the rolling-volume editors unanimously reported being very satisfied with their model. This high satisfaction rate is reflected in editors’ positions that they were very unlikely to switch away from the rolling-volume method. While a majority of editors of discrete-issue journals also reported being very satisfied or somewhat satisfied with their current model, the mixed responses to whether they would contemplate switching to the alternate model suggests that awareness of the benefits of rolling-volume publishing is increasing. Conclusion – Researchers discovered a greater incidence of rolling-volume model journals with open access LIS journals than anticipated, suggesting that this is an area where additional research is necessary. The relative newness of the rolling-volume model may be a contributing factor to the high satisfaction rate among editors of journals using this model, as journal editors are likely to be more deliberate in selecting this model over the traditional discrete-issue publishing model. Workflow and production practices were identified as key characteristics for selecting a publishing model regardless of the model selected, and therefore this is another area in need of further investigation.


2013 ◽  
Vol 393 ◽  
pp. 839-844 ◽  
Author(s):  
Mohamad Shukri Zakaria ◽  
Kahar Osman ◽  
Mohd Noor Asril Saadun ◽  
Muhammad Zaidan Abdul Manaf ◽  
Mohd Hafidzal Mohd Hanafi

Research on the waste energy and emission has been quite intensive recently. The formation, venting and flared the Boil-off gas (BOG) considered as one of the contribution to the Greenhouse Gas (GHG) emission nowadays. The current model or method appearing in the literature is unable to analyze the real behavior of the vapor inside Liquefied Natural Gas (LNG) tank and unable to accurately estimate the amount of boil-off gas formation. In this paper, evaporation model is used to estimate LNG Boil-Off rate (BOR) inside LNG tank. Using User Define Function (UDF) hooked to the software ANSYS Fluent. The application enable drag law and alternative heat transfer coefficient to be included. Three dimensional membrane type LNG cargos are simulated with selected boundary condition located in the United States Gulf Coast based on average weather conditions. The result shows that the value of BOR agrees well with the previous study done with another model and with International Marine organization (IMO) standard which is less than 0.15% weight per day. The results also enable us to visualize the LNG evaporation behaviors inside LNG tanks.


2017 ◽  
Vol 7 (3) ◽  
pp. 893-917
Author(s):  
David Lausch ◽  
Eric Teman ◽  
Cody Perry

International students’ identities are complex and so are their needs. Semistructured interviews with 13 of the lead researcher’s former students from Dubai, United Arab Emirates, who are multi-national, multi-lingual and pursuing degrees in law, business, economics, medicine, education, art and media, in the United States, United Kingdom and Australia elucidated this reality. Their experiences demonstrated scholastic and pabulum frustrations that were offset in part by constant communication with their clans in person and through various technologies. Though the current model of higher education often seeks to identify and categorize international students as a group, this study shows that international students are unique individuals. Recognizing their individuality, higher education institutions and policymakers can more appropriately respond to international students’ needs.


Author(s):  
Robert Jackson ◽  
Georg Sørensen

This chapter examines three important debates in International Political Economy (IPE). The first debate concerns power and the relationship between politics and economics, and more specifically whether politics is in charge of economics or whether it is the other way around. The second debate deals with development and underdevelopment in developing countries. The third debate is about the nature and extent of economic globalization, and currently takes places in a context of increasing inequality between and inside countries. This debate is also informed by the serious financial crisis of 2008 and has raised questions regarding the viability of the current model of capitalism in the United States and Western Europe.


2020 ◽  
pp. 75-97
Author(s):  
Dawn Barker Floyd ◽  
Michael Funk Deckard

Colleges and universities in the United States have been challenged to implement sometimes vague and constantly evolving federal laws and departmental guidance regarding how to respond to and prevent gender-based violence (GBV). State legislatures are also creating laws that may not be consistent with federal law and guidance. This chapter challenges the current model for addressing GBV by suggesting that, to be truly transformational, universities must give pedagogical time and space to the root causes and cultural underpinnings of GBV. The chapter describes a year-long interdisciplinary course offered to freshmen, co-taught by a philosophy professor and the Title IX coordinator, which, to transform students’ understanding, uses philosophers such as Plato to examine sexual violence and how it is structured in Western culture. The authors advocate for universities to incorporate classroom and organizational responses and collaborations to mitigate a culture of violence to eradicate GBV from higher education.


1998 ◽  
Vol 64 (2) ◽  
pp. 405-410 ◽  
Author(s):  
Scot E. Dowd ◽  
Suresh D. Pillai ◽  
Sookyun Wang ◽  
M. Yavuz Corapcioglu

ABSTRACT Many of the factors controlling viral transport and survival within the subsurface are still poorly understood. In order to identify the precise influence of viral isoelectric point on viral adsorption onto aquifer sediment material, we employed five different spherical bacteriophages (MS2, PRD1, Qβ, φX174, and PM2) having differing isoelectric points (pI 3.9, 4.2, 5.3, 6.6, and 7.3 respectively) in laboratory viral transport studies. We employed conventional batch flowthrough columns, as well as a novel continuously recirculating column, in these studies. In a 0.78-m batch flowthrough column, the smaller phages (MS2, φX174, and Qβ), which had similar diameters, exhibited maximum effluent concentration/initial concentration values that correlated exactly with their isoelectric points. In the continuously recirculating column, viral adsorption was negatively correlated with the isoelectric points of the viruses. A model of virus migration in the soil columns was created by using a one-dimensional transport model in which kinetic sorption was used. The data suggest that the isoelectric point of a virus is the predetermining factor controlling viral adsorption within aquifers. The data also suggest that when virus particles are more than 60 nm in diameter, viral dimensions become the overriding factor.


2003 ◽  
Vol 69 (1) ◽  
pp. 350-357 ◽  
Author(s):  
Suphachai Nuanualsuwan ◽  
Dean O. Cliver

ABSTRACT The exceptional stability of enteric viruses probably resides in their capsids. The capsid functions of inactivated human picornaviruses and feline calicivirus (FCV) were determined. Viruses were inactivated by UV, hypochlorite, high temperature (72°C), and physiological temperature (37°C), all of which are pertinent to transmission via food and water. Poliovirus (PV) and hepatitis A virus (HAV) are transmissible via water and food, and FCV is the best available surrogate for the Norwalk-like viruses, which are leading causes of food-borne and waterborne disease in the United States. The capsids of all 37°C-inactivated viruses still protected the viral RNA against RNase, even in the presence of proteinase K, which contrasted with findings with viruses inactivated at 72°C. The loss of ability of the virus to attach to homologous cell receptors was universal, regardless of virus type and inactivation method, except for UV-inactivated HAV, and so virus inactivation was almost always accompanied by the loss of virus attachment. Inactivated HAV and FCV were captured by homologous antibodies. However, inactivated PV type 1 (PV-1) was not captured by homologous antibody and 37°C-inactivated PV-1 was only partially captured. The epitopes on the capsids of HAV and FCV are evidently discrete from the receptor attachment sites, unlike those of PV-1. These findings indicate that the primary target of UV, hypochlorite, and 72°C inactivation is the capsid and that the target of thermal inactivation (37°C versus 72°C) is temperature dependent.


2020 ◽  
Vol 158 (5) ◽  
pp. 416-430
Author(s):  
H. M. Menendez ◽  
L. O. Tedeschi

AbstractPerception of freshwater use varies between nations and has led to concerns of how to evaluate water use for sustainable food production. The water footprint of beef cattle (WFB) is an important metric to determine current levels of freshwater use and to set sustainability goals. However, current WFB publications provide broad WF values with inconsistent units preventing direct comparison of WFB models. The water footprint assessment (WFA) methodologies use static physio-enviro-managerial equations, rather than dynamic, which limits their ability to estimate cattle water use. This study aimed to advance current WFA methods for WFB estimation by formulating the WFA into a system dynamics methodology to adequately characterize the major phases of the beef cattle industry and provide a tool to identify high-leverage solutions for complex water use systems. Texas is one of the largest cattle producing areas in the United States, a significant water user. This geolocation is an ideal template for WFB estimation in other regions due to its diverse geography, management-cultures, climate and natural resources. The Texas Beef Water Footprint model comprised seven submodels (cattle population, growth, nutrition, forage, WFB, supply chain and regional water use; 1432 state variables). Calibration of our model replicated initial WFB values from an independent study by Chapagain and Hoekstra in 2003 (CH2003). This CH2003 v. Texas production scenarios evaluated model parameters and assumptions and estimated a 41–66% WFB variability. The current model provides an insightful tool to improve complex, unsustainable and inefficient water use systems.


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