162 research outputs found
Bacterial cellulose-lactoferrin as an antimicrobial edible packaging
Bacterial cellulose (BC) films from two distinct sources (obtained by static culture with Gluconacetobacter xylinus ATCC 53582 (BC1) and from a commercial source (BC2)) were modified by bovine lactoferrin (bLF) adsorption. The functionalized films (BC+bLF) were assessed as edible antimicrobial packaging, for use in direct contact with highly perishable foods, specifically fresh sausage as a model of meat products. BC+bLF films and sausage casings were characterized regarding their water vapour permeability (WVP), mechanical properties, and bactericidal efficiency against two food pathogens, Escherichia coli and Staphylococcus aureus. Considering their edibility, an in vitro gastrointestinal tract model was used to study the changes occurring in the BC films during passage through the gastrointestinal tract. Moreover, the cytotoxicity of the BC films against 3T3 mouse embryo fibroblasts was evaluated.
BC1 and BC2 showed equivalent density, WVP and maximum tensile strength. The percentage of bactericidal efficiency of BC1 and BC2 with adsorbed bLF (BC1+bLF and BC2+bLF, respectively) in the standalone films and in inoculated fresh sausages, was similar against E. coli (mean reduction 69 % in the films per se versus 94 % in the sausages) and S. aureus (mean reduction 97 % in the films per se versus 36 % in the case sausages). Moreover, the BC1+bLF and BC2+bLF films significantly hindered the specific growth rate of both bacteria. Finally, no relevant cytotoxicity against 3T3 fibroblasts was found for the films before and after the simulated digestion. BC films with adsorbed bLF may constitute an approach in the development of bio-based edible antimicrobial packaging systems.The authors would like to acknowledge Portuguese Foundation
for Science and Technology (Fundação para a Ciência e Tecnologia)
for the research grants: Jorge Padrão SFRH/BD/64901/2009, Sara
Gonçalves SFRH/BD/63578/2009, João Pedro Silva SFRH/BPD/
64958/2009, Ana Cristina Pinheiro SFRH/BPD/101181/2014. V.
Sencadas thanks support from the COST Action MP1206: “Electrospun
nano-fibres for bio inspired composite materials and innovative
industrial applications” and MP1301: “New Generation
Biomimetic and Customized Implants for Bone Engineering”. The
authors would also like to thank the co-funded by the Programa
Operacional Regional do Norte (ON.2 e O Novo Norte), QREN,
FEDER Projects “BioHealth e Biotechnology and Bioengineering
approaches to improve health quality”, Ref. NORTE-07-0124-
FEDER-000027; “BioInd e Biotechnology and Bioengineering for
improved Industrial and Agro-Food processes”, REF. NORTE-07-
0124-FEDER-000028; Strategic Project PEST-C/FIS/UI607/2014;
Matepro eOptimizing Materials and Processes”, ref. NORTE-07-
0124-FEDER-000037; Strategic Project PEst-OE/EQB/LA0023/2013
and project ref. RECI/BBB-EBI/0179/2012 (project number FCOMP-
01-0124-FEDER-027462). Finally, the authors thank the Fundação
para a Ciência e Tecnologia for the strategic funding from the UID/
BIO/04469/2013 unit
Epistemic policy networks in the European Union’s CBRN risk mitigation policy
This paper offers insights into an innovative and currently flagship approach of the European Union (EU) to the mitigation of chemical, biological, radiological, and nuclear (CBRN) risks. Building on its long-time experience in the CBRN field, the EU has incorporated methods familiar to the students of international security governance: it is establishing regional networks of experts and expertise. CBRN Centers of Excellence, as they are officially called, aim to contribute to the security and safety culture in different parts of Africa, the Middle East, South East Asia, and South East Europe, in the broadly construed CBRN area. These regional networks represent a modern form of security cooperation, which can be conceptualized as an epistemic policy networks approach. It offers flexibility to the participating states, which have different incentives to get involved. At the same, however, the paper identifies potential limitations and challenges of epistemic policy networks in this form
Work Hours and Self rated Health of Hospital Doctors in Norway and Germany. A comparative study on national samples
<p>Abstract</p> <p>Background</p> <p>The relationship between extended work hours and health is well documented among hospital doctors, but the effect of national differences in work hours on health is unexplored. The study examines the relationship between work hours and self rated health in two national samples of hospital doctors.</p> <p>Methods</p> <p>The study population consisted of representative samples of 1,260 German and 562 Norwegian hospital doctors aged 25-65 years (N = 1,822) who received postal questionnaires in 2006 (Germany) and 2008 (Norway). The questionnaires contained items on demography, work hours (number of hours per workday and on-call per month) and self rated subjective health on a five point scale - dichotomized into "good" (above average) and "average or below".</p> <p>Results</p> <p>Compared to Norway, a significantly higher proportion of German doctors exceeded a 9 hour work day (58.8% vs. 26.7%) and 60 hours on-call per month (63.4% vs. 18.3%). Every third (32.2%) hospital doctor in Germany worked more than this, while this pattern was rare in Norway (2.9%). In a logistic regression model, working in Norway (OR 4.17; 95% CI 3.02-5.73), age 25-44 years (OR 1.66; 95% CI 1.29-2.14) and not exceeding 9 hour work day and 60 hours on-call per month (OR 1.35; 95% CI 1.03-1.77) were all independent significant predictors of good self reported health.</p> <p>Conclusion</p> <p>A lower percentage of German hospital doctors reported self rated health as "good", which is partly explained by the differences in work time pattern. Initiatives to increase doctors' control over their work time are recommended.</p
Explosion reactivity characterisation of pulverised torrefied spruce wood
Pulverised biomass is increasingly being used for power generation in 100% biomass plants or mixed with coal as a way of reducing greenhouse gas emissions. The fire and explosion hazards of pulverised wood and other agricultural waste materials have been recognised for some time. However, safety data for biomass are very scarce in the public literature, and non-existent for upgraded biomass products such as torrefied biomass. This is largely due to the challenges that biomass poses for explosion characterisation in the standard methods (1 m3 ISO vessel or 20 L sphere). The authors have developed and calibrated a new system for the 1 m3 ISO vessel that overcomes these challenges. In this work we present the first data in the open literature for the explosion characteristics of torrefied biomass. Results for untreated Norway spruce wood and Kellingley coal are also included for comparison. Flame speeds and post-explosion residue analysis results are also presented. Torrefied spruce wood was found to be more reactive than Kellingley coal and slightly more reactive than its parent material in terms of KSt, Pmax and flame speed. The differences between coal and biomass samples highlight that it should not be assumed that safety systems for coal can be applied to torrefied or raw wood materials without suitable modifications
Computational toxicology using the OpenTox application programming interface and Bioclipse
BACKGROUND: Toxicity is a complex phenomenon involving the potential adverse effect on a range of biological functions. Predicting toxicity involves using a combination of experimental data (endpoints) and computational methods to generate a set of predictive models. Such models rely strongly on being able to integrate information from many sources. The required integration of biological and chemical information sources requires, however, a common language to express our knowledge ontologically, and interoperating services to build reliable predictive toxicology applications. FINDINGS: This article describes progress in extending the integrative bio- and cheminformatics platform Bioclipse to interoperate with OpenTox, a semantic web framework which supports open data exchange and toxicology model building. The Bioclipse workbench environment enables functionality from OpenTox web services and easy access to OpenTox resources for evaluating toxicity properties of query molecules. Relevant cases and interfaces based on ten neurotoxins are described to demonstrate the capabilities provided to the user. The integration takes advantage of semantic web technologies, thereby providing an open and simplifying communication standard. Additionally, the use of ontologies ensures proper interoperation and reliable integration of toxicity information from both experimental and computational sources. CONCLUSIONS: A novel computational toxicity assessment platform was generated from integration of two open science platforms related to toxicology: Bioclipse, that combines a rich scriptable and graphical workbench environment for integration of diverse sets of information sources, and OpenTox, a platform for interoperable toxicology data and computational services. The combination provides improved reliability and operability for handling large data sets by the use of the Open Standards from the OpenTox Application Programming Interface. This enables simultaneous access to a variety of distributed predictive toxicology databases, and algorithm and model resources, taking advantage of the Bioclipse workbench handling the technical layers
The Minimum Balance at Risk: A Proposal to Mitigate the Systemic Risks Posed by Money Market Funds
This paper introduces a proposal for money market fund (MMF) reform that could mitigate systemic risks arising from these funds by protecting shareholders, such as retail investors, who do not redeem quickly from distressed funds. Our proposal would require that a small fraction of each MMF investor's recent balances, called the minimum balance at risk (MBR), be demarcated to absorb losses if the fund is liquidated. Most regular transactions in the fund would be unaffected, but redemptions of the MBR would be delayed for thirty days. A key feature of the proposal is that large redemptions would subordinate a portion of an investor's MBR, creating a disincentive to redeem if the fund is likely to have losses. In normal times, when the risk of MMF losses is remote, subordination would have little effect on incentives. We use empirical evidence, including new data on MMF losses from the U.S. Treasury and the Securities and Exchange Commission, to calibrate an MBR rule that would reduce the vulnerability of MMFs to runs and protect investors who do not redeem quickly in crises
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