184 research outputs found
Geraniol and Linalool Loaded Nanoemulsions and Their Antimicrobial Activity
Geraniol and linalool have been found to be effective against foodborne microorganisms in vitro. However, due to their hydrophobic nature, it is difficult to achieve an even dispersion in foods with high water content resulting in dramatic loss of activity. The aim of the study was to fabricate geraniol or linalool nanoemulsions and investigate their effect against Escherichia coli K12, Listeria innocua and Pseudomonas lundensis in a meat simulation medium. The agar diffusion assay revealed that both geraniol and linalool had a potent antimicrobial activity against all bacteria. Dynamic light scattering showed that geraniol and linalool nanoemulsions had a mean diameter of 68.22±2.46 and 173.59±4.15 nm, respectively. Killing assay results showed that both nanoemulsions were able to significantly reduce E. coli and L. innocua counts by approx. 3 log CFU/ml. Ps. lundensis proved to be more resistant to both nanoemulsions showing a reduction of approx. 1.2 log CFU/ml,. Overall, this study showed that nanoemulsions loaded with geraniol or linalool represent a promising antimicrobial system to improve food preservation and food safety
Microstructural Characterization of a Prototype Titanium Alloy Structure Processed via Direct Laser Deposition (DLD)
Parameterising User Uptake in Economic Evaluations: The role of discrete choice experiments.
Model-based economic evaluations of new interventions have shown that user behaviour (uptake) is a critical driver of overall impact achieved. However, early economic evaluations, prior to introduction, often rely on assumed levels of uptake based on expert opinion or uptake of similar interventions. In addition to the likely uncertainty surrounding these uptake assumptions, they also do not allow for uptake to be a function of product, intervention, or user characteristics. This letter proposes using uptake projections from discrete choice experiments (DCE) to better parameterize uptake and substitution in cost-effectiveness models. A simple impact model is developed and illustrated using an example from the HIV prevention field in South Africa. Comparison between the conventional approach and the DCE-based approach shows that, in our example, DCE-based impact predictions varied by up to 50% from conventional estimates and provided far more nuanced projections. In the absence of observed uptake data and to model the effect of variations in intervention characteristics, DCE-based uptake predictions are likely to greatly improve models parameterizing uptake solely based on expert opinion. This is particularly important for global and national level decision making around introducing new and probably more expensive interventions, particularly where resources are most constrained
Vertical stratification of phytoplankton biomass in a deep estuary site: implications for satellite-based net primary productivity
The accuracy of satellite estimates for water column net primary productivity (NPP) are contingent upon the reliability of surface phytoplankton biomass, specifically chlorophyll a (Chl.a) and carbon (Cphyt), as indicators of euphotic biomass and photosynthetic rate. We assessed patterns in water column biomass at a deep estuary site (~40 m) in the Firth of Thames, Hauraki Gulf, New Zealand, using ten years (2005-2015) of in situ sampling (40 seasonal voyages and moored instrumentation). Seasonal biomass stratification coincided with physical and chemical stratification and exhibited a reasonable predictability based on surface Chl.a measures from mooring timeseries. High Chl.a (but not Cphyt) accumulated from late-spring (Nov.) in the lower portion of the water column, under nutrient deficient, clear surface water with deep euphotic zone conditions, peaking in mid-summer (Jan.) and ending by early autumn (Mar.). Satellite (MODIS-Aqua) NPP (2002-2018), was estimated with and without correction for deep biomass in two vertically generalized production models (Chl.a-VGPM and Cphyt-CbPM). Mean annual NPP (220-161 g C m-2 y-1, VGPM and CbPM respectively) increased 5-18% after accounting for euphotic zone deep biomass with a mid-summer maxim (Jan.: 30-33%). Interannual anomalies in biomass and NPP (about -10% to 10%) were an order of magnitude greater than small decreasing trends (<< 1% y-1). We discuss the impacts of observational factors on biomass and NPP estimation. We offer contextual insights into seasonal patterns by considering previous observations of biomass trends and nutrient enrichment in the Firth of Thames region. We propose future directions in accounting for deep biomass variations from shallow coastal areas to deeper continental shelf waters
A novel natural antimicrobial can reduce the in vitro and in vivo pathogenicity of T6SS positive Campylobacter jejuni and campylobacter coli chicken isolates
© 2018 Sima, Stratakos, Ward, Linton, Kelly, Pinkerton, Stef, Gundogdu, Lazar and Corcionivoschi. Human campylobacteriosis is considered one of the most common foodborne diseases worldwide with poultry identified as the main source of infection accounting for 50-80% of human cases. Highly virulent Campylobacter spp., positive for the Type VI secretion system (T6SS), which have an increased ability to adhere to and invade the host gastrointestinal epithelium are highly prevalent in poultry. Multidrug resistant strains of bacteria are rapidly evolving and therefore, new antimicrobials to supplement animal feed that are able to control Campylobacter species, are in great need. The work presented herein indicates that a novel phenolic antimicrobial, Auranta 3001, is able to reduce the adhesion and invasion of human intestinal epithelial cells (HCT-8) by two T6SS positive chicken isolates, C. jejuni RC039 (p < 0.05) and C. coli RC013 (p < 0.001). Exposure of C. jejuni RC039 and C. coli RC013 to Auranta 3001 downregulated the expression of hcp and cetB genes, known to be important in the functionality of T6SS. Furthermore, the reduced adhesion and invasion is associated with a significant decrease in bacterial motility of both isolates (p < 0.05-p < 0.001) in vitro. Most importantly our in vivo results show that Auranta 3001 is able to reduce cecum colonization levels from log 8 CFU/ml to log 2 CFU/ml for C. jejuni RC039 and from log 7 CFU/ml to log 2 CFU/ml for C. coli RC013. In conclusion, this novel antimicrobial is able to reduce the pathogenic properties of T6SS campylobacters in vitro and also to decrease colonization in vivo
Attenuation of Vibrio parahaemolyticus Virulence Factors by a Mixture of Natural Antimicrobials.
Reducing acute mortality in aquatic crustaceans using natural alternatives to antibiotics has become a necessity, firstly for its positive impact on the aquaculture industry and, secondly, because the extensive use of antibiotics may lead to increased levels of drug resistance in pathogenic microorganisms. This study aimed to investigate the effect of a mixture of natural antimicrobials on the in vitro and in vivo virulence abilities of Type VI secretion system (T6SS)-positive Vibrio parahaemolyticus (A3 and D4), strains known as having potentially harmful health consequences for aquatic crustaceans and consumers. Herein, we report that a natural antimicrobial mixture (A3009) was capable of significantly reducing the virulence of V. parahaemolyticus strains A3 and D4 in an in vitro infection model, using the fish cell line CHSE-214, an effect which correlates with the bacterial downregulation of hcp1 and hcp2 gene expression and with the ability of the antimicrobial to efficiently retain low cytotoxic levels (p < 0.001). We show for the first time that a natural antimicrobial is able to significantly reduce the mortality of shrimps in a challenge experiment and is able to significantly attenuate H2O2 release during infection (p < 0.001), indicating that it could harbor positive intestinal redox balance effects
The Grizzly, September 4, 2014
Zipcar Comes to Ursinus • Freshmen Placed in Main Street Houses • New Janitorial Staff at Ursinus • International Students on the Rise • Thousands Flock to Phoenixville • Discomfort of Coming Home • Access Urban Areas for Under $20 • Opinion: Ice Bucket Challenge Raises Millions, Most People Take the Easy Way Out; Lost Da Vinci Fresco • Field Hockey Looking to Repeat • Hitting the Ground Runninghttps://digitalcommons.ursinus.edu/grizzlynews/1907/thumbnail.jp
The Grizzly, October 23, 2014
Website Launching • Homecoming Kicking Off This Weekend • Board to Discuss New President • Good Neighbors Debuting This Week • Grizzly Gala Returning • American Class Style Can be Surprising • Throop Researches Medieval Europe • U-Innovate Competition Returns • Don\u27t Forget About Small Majors • Opinion: The Problem With Capital Punishment; Extraterrestrial Existence: Reason to Believe? • Football Team Preparing for Homecoming • Serving Up Success • Field Hockey Dashes to 11-2 Starthttps://digitalcommons.ursinus.edu/grizzlynews/1913/thumbnail.jp
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