1,309 research outputs found

    Improved antimicrobial activity of nisin-incorporated polymer films by formulation change and addition of food grade chelator

    Get PDF
    Aims: The following polymers were developed: polyethylene (PE), a PE and polyethylene oxide (70% PE and 30% PEO; PE + PEO) blend, PE and nisin (PE + nisin), PE, nisin, and EDTA (PE + nisin + EDTA), and PE + PEO with nisin (PE + PEO + nisin). Methods and Results: Of the polymers tested, PE and PE + PEO did not exhibit any antimicrobial activity against Brochothrix thermosphacta (BT); however, PE + nisin, PE + nisin + EDTA, and PE + PEO + nisin did. Beef surfaces were experimentally inoculated with 3·50 log10 cfu/cm2 of BT, vacuum packaged with each of the five polymers, and held at 4°C for 21 d. After 3 d at 4°C, BT was reduced \u3e 1·70 log10 by PE + nisin and \u3e 3·50 log10 with PE + nisin + EDTA or PE + PEO + nisin. By 21 d at 4°C, BT was reduced to 0·30 log10 cfu/cm2 when treated with PE + PEO + nisin. Conclusions: It appears that PE + PEO + nisin or PE + nisin + EDTA were more effective for reducing BT, as compared to polymers composed of PE + nisin. Significance and Impact of the Study: Nisin-incorporated polymers may control the growth of undesirable bacteria, thereby extending the shelf life and possibly enhancing the microbial safety of meats

    Improved antimicrobial activity of nisin-incorporated polymer films by formulation change and addition of food grade chelator

    Get PDF
    Aims: The following polymers were developed: polyethylene (PE), a PE and polyethylene oxide (70% PE and 30% PEO; PE + PEO) blend, PE and nisin (PE + nisin), PE, nisin, and EDTA (PE + nisin + EDTA), and PE + PEO with nisin (PE + PEO + nisin). Methods and Results: Of the polymers tested, PE and PE + PEO did not exhibit any antimicrobial activity against Brochothrix thermosphacta (BT); however, PE + nisin, PE + nisin + EDTA, and PE + PEO + nisin did. Beef surfaces were experimentally inoculated with 3·50 log10 cfu/cm2 of BT, vacuum packaged with each of the five polymers, and held at 4°C for 21 d. After 3 d at 4°C, BT was reduced \u3e 1·70 log10 by PE + nisin and \u3e 3·50 log10 with PE + nisin + EDTA or PE + PEO + nisin. By 21 d at 4°C, BT was reduced to 0·30 log10 cfu/cm2 when treated with PE + PEO + nisin. Conclusions: It appears that PE + PEO + nisin or PE + nisin + EDTA were more effective for reducing BT, as compared to polymers composed of PE + nisin. Significance and Impact of the Study: Nisin-incorporated polymers may control the growth of undesirable bacteria, thereby extending the shelf life and possibly enhancing the microbial safety of meats

    The biomechanical strength of olecranon fixation constructs: a systematic review and meta-regression

    Get PDF
    Olecranon fractures are often operative when displaced over 2 mm, but the most stable fixation construct is debated. The purpose of this study was to provide an overview of biomechanical properties of the most commonly used surgical fixations of olecranon fractures. This systematic review included 13 biomechanical studies comparing displacement during cyclic loading of olecranon fractures fixated with either tension band wiring (TBW), intramedullary screw, or plate fixation. In regard to overall gapping, plates displayed (and screws trended towards) increased stability versus TBW. However, there was no difference between the constructs in gapping at the articular surface. Plating displayed increased stability along the posterior surface. No construct allowed gapping over 2 mm, suggesting safe early post-operative motion with any of the techniques

    Reading sentences of uniform word length II: very rapid adaptation of the preferred saccade length

    Get PDF
    In the current study we investigated whether readers adjust their preferred saccade length (PSL) during reading on a trial-by-trial basis. The PSL refers to the distance between a saccade launch site and saccade target (i.e., the word center during reading) when participants neither undershoot nor overshoot this target (McConkie, Kerr, Reddix, & Zola, 1988). The tendency for saccades longer or shorter than the PSL to under or overshoot their target is referred to as the range error. Recent research by Cutter, Drieghe, and Liversedge (2017) has shown that the PSL changes to be shorter when readers are presented with thirty consecutive sentences exclusively made of three letter words, and longer when presented with thirty consecutive sentences exclusively made of five letter words. We replicated and extended this work by this time presenting participants with these uniform sentences in an unblocked design. We found that adaptation still occurred across different sentence types despite participants only having one trial to adapt. Our analyses suggested that this effect was driven by the length of the words readers were making saccades away from, rather than the length of the words in the rest of the sentence. We propose an account of the range error in which readers use parafoveal word length information to estimate the length of a saccade between the centre of two parafoveal words (termed the Centre-Based Saccade Length) prior to landing on the first of these words

    Indoor Carbon Monoxide: A Case Study in England for Detection and Interventions to Reduce Population Exposure

    Get PDF
    Background. Potential exposure to carbon monoxide (CO) in private homes is largely unquantified. Aim. To estimate prevalence of potential exposure to CO in residential dwellings and describe associated interventions in an inner-city community. Methods. A housing association in London, Hackney Homes, began fitting CO alarms in the 22,831 local authority homes it is responsible for in January 2010. A gas engineer investigated each alarm activation and recorded the information on a standard form. We undertook a cross-sectional study of all 22,831 homes, using data from these forms. Descriptive analysis was performed, including incidence, monthly variation, cause of alarm activation, and actions taken. Results. Between November 2011 and April 2012, 106 incidents were reported. Of these, 34.6% identified an issue with a gas appliance, and 10.6% identified misuse of cooking methods as the cause of activation. Relevant interventions were put in place, including disconnection of the gas appliance and education around cooking methods. Discussion. Little is known about the burden of CO poisoning in residential dwellings. This study provides important information on the path to quantifying population exposure to CO as well as establishing a possible approach to access this key information and realistic interventions to reduce potential exposure

    Divergent responses of Atlantic coastal and oceanic Synechococcus to iron limitation

    Get PDF
    Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 112 (2015): 9944-9949, doi:10.1073/pnas.1509448112.Marine Synechococcus are some of the most diverse and ubiquitous phytoplankton, and iron (Fe) is an essential micronutrient that limits productivity in many parts of the ocean. To investigate how coastal and oceanic Atlantic Synechococcus strains acclimate to Fe availability, we compared the growth, photophysiology, and quantitative proteomics of two Synechococcus strains from different Fe regimes. Synechococcus strain WH8102, from a region in the southern Sargasso Sea that receives substantial dust deposition, showed impaired growth and photophysiology as Fe declined, yet utilized few acclimation responses. Coastal WH8020, from the dynamic, seasonally variable New England shelf, displayed a multi-tiered, hierarchical cascade of acclimation responses with different Fe thresholds. The multi-tiered response included changes in Fe acquisition, storage, and photosynthetic proteins, substitution of flavodoxin for ferredoxin, and modified photophysiology, all while maintaining remarkably stable growth rates over a range of Fe concentrations. Modulation of two distinct ferric uptake regulator (Fur) proteins that coincided with the multi-tiered proteome response was found, implying the coastal strain has different regulatory threshold responses to low Fe availability. Low nitrogen (N) and phosphorus (P) availability in the open ocean may favor the loss of Fe response genes when Fe availability is consistent over time, whereas these genes are retained in dynamic environments where Fe availability fluctuates and N and P are more abundant.This work was supported by a National Science Foundation Postdoctoral Research Fellowship in Biology to K.R.M.M. (NSF 1103575), National Science Foundation Oceanography grants OCE-1220484, OCE-0928414, OCE-1233261, OCE- 1155566, OCE-1131387, and OCE-0926092, as well as Gordon and Betty Moore Foundation grants 3782 and 3934

    Divergent Responses of Atlantic Coastal and Oceanic Synechococcus to Iron Limitation

    Get PDF
    Marine Synechococcus are some of the most diverse and ubiquitous phytoplankton, and iron (Fe) is an essential micronutrient that limits productivity in many parts of the ocean. To investigate how coastal and oceanic Atlantic Synechococcus strains acclimate to Fe availability, we compared the growth, photophysiology, and quantitative proteomics of two Synechococcus strains from different Fe regimes. Synechococcus strain WH8102, from a region in the southern Sargasso Sea that receives substantial dust deposition, showed impaired growth and photophysiology as Fe declined, yet used few acclimation responses. Coastal WH8020, from the dynamic, seasonally variable New England shelf, displayed a multitiered, hierarchical cascade of acclimation responses with different Fe thresholds. The multitiered response included changes in Fe acquisition, storage, and photosynthetic proteins, substitution of flavodoxin for ferredoxin, and modified photophysiology, all while maintaining remarkably stable growth rates over a range of Fe concentrations. Modulation of two distinct ferric uptake regulator (Fur) proteins that coincided with the multitiered proteome response was found, implying the coastal strain has different regulatory threshold responses to low Fe availability. Low nitrogen (N) and phosphorus (P) availability in the open ocean may favor the loss of Fe response genes when Fe availability is consistent over time, whereas these genes are retained in dynamic environments where Fe availability fluctuates and N and P are more abundant

    Indoor Carbon Monoxide: A Case Study in England for Detection and Interventions to Reduce Population Exposure

    Get PDF
    Background. Potential exposure to carbon monoxide (CO) in private homes is largely unquantified. Aim. To estimate prevalence of potential exposure to CO in residential dwellings and describe associated interventions in an inner-city community. Methods. A housing association in London, Hackney Homes, began fitting CO alarms in the 22,831 local authority homes it is responsible for in January 2010. A gas engineer investigated each alarm activation and recorded the information on a standard form. We undertook a cross-sectional study of all 22,831 homes, using data from these forms. Descriptive analysis was performed, including incidence, monthly variation, cause of alarm activation, and actions taken. Results. Between November 2011 and April 2012, 106 incidents were reported. Of these, 34.6% identified an issue with a gas appliance, and 10.6% identified misuse of cooking methods as the cause of activation. Relevant interventions were put in place, including disconnection of the gas appliance and education around cooking methods. Discussion. Little is known about the burden of CO poisoning in residential dwellings. This study provides important information on the path to quantifying population exposure to CO as well as establishing a possible approach to access this key information and realistic interventions to reduce potential exposure
    corecore