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1.
Reg Environ Change ; 23(2): 52, 2023.
Article in English | MEDLINE | ID: mdl-36968261

ABSTRACT

The dependence on imports of the Middle East and North Africa (MENA) region for its food needs has increased steadily since the early 1960s, from 10% to about 40%. This import dependence could continue to rise in coming decades due to the projected MENA population growth and the expected negative impacts of climate change on the region's natural resources and agricultural performances. To what extent the food import dependency of the MENA region will continue to increase up to 2050 and how the region could mitigate its rising reliance on food imports is both a key question for the region itself and a crucial geopolitical issue for the world as a whole. In this paper, we use a biomass balance model to assess the level of the food import dependency of the MENA region in 2050 resulting from six scenarios. We show that under current trends and severe impacts of climate change the food import dependency of the MENA would continue to rise and reach 50% in 2050. Maghreb would be particularly affected becoming dependent on imports for almost 70% of its food needs. Adopting a Mediterranean diet, reaching faster productivity growth in agriculture or reducing waste and loss along the food chain would contribute to decelerate the rise of the MENA's food import dependency. However, only the combination of these three options could significantly offset the increased import dependency in the most affected sub-regions: Maghreb, the Middle and the Near East. In all scenarios, Turkey strengthens its position as a net exporter of agricultural products. Supplementary Information: The online version contains supplementary material available at 10.1007/s10113-023-02045-y.

2.
Appl Environ Microbiol ; 80(4): 1469-76, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24362424

ABSTRACT

We investigated the amplification and purification of phage preparations with respect to titer, contamination level, stability, and technical affordability. Using various production systems (wave bags, stirred-tank reactors, and Erlenmeyer flasks), we obtained peak titers of 10(9) to 10(10) PFU/ml for T4-like coliphages. Phage lysates could be sterilized through 0.22-µm membrane filters without titer loss. Phages concentrated by differential centrifugation were not contaminated with cellular debris or bacterial proteins, as assessed by electron microscopy and mass spectrometry, respectively. Titer losses occurred by high-speed pelleting of phages but could be decreased by sedimentation through a sucrose cushion. Alternative phage concentration methods are prolonged medium-speed centrifugation, strong anion-exchange chromatography, and ultrafiltration, but the latter still allowed elevated lipopolysaccharide contamination. T4-like phages could not be pasteurized but maintained their infectivity titer in the cold chain. In the presence of 10 mM magnesium ions, phages showed no loss of titer over 1 month at 30°C.


Subject(s)
Bacteriophage T4/growth & development , Bacteriophage T4/isolation & purification , Biological Therapy/methods , Escherichia coli/virology , Centrifugation/methods , Drug Stability , Drug Storage , Filtration/methods , Mass Spectrometry , Microscopy, Electron , Virology/methods
3.
Virology ; 443(2): 187-96, 2013 Sep 01.
Article in English | MEDLINE | ID: mdl-23755967

ABSTRACT

Phage therapy has a long tradition in Eastern Europe, where preparations are comprised of complex phage cocktails whose compositions have not been described. We investigated the composition of a phage cocktail from the Russian pharmaceutical company Microgen targeting Escherichia coli/Proteus infections. Electron microscopy identified six phage types, with numerically T7-like phages dominating over T4-like phages. A metagenomic approach using taxonomical classification, reference mapping and de novo assembly identified 18 distinct phage types, including 7 genera of Podoviridae, 2 established and 2 proposed genera of Myoviridae, and 2 genera of Siphoviridae. De novo assembly yielded 7 contigs greater than 30 kb, including a 147-kb Myovirus genome and a 42-kb genome of a potentially new phage. Bioinformatic analysis did not reveal undesired genes and a small human volunteer trial did not associate adverse effects with oral phage exposure.


Subject(s)
Bacteriophages , Biological Therapy/adverse effects , Biological Therapy/methods , Escherichia coli Infections/therapy , Metagenomics/methods , Proteus Infections/therapy , Administration, Oral , Bacteriophages/classification , Bacteriophages/genetics , Bacteriophages/ultrastructure , Gram-Negative Bacteria/classification , Gram-Negative Bacteria/virology , Humans , Microscopy, Electron, Transmission , Myoviridae/classification , Myoviridae/genetics , Myoviridae/ultrastructure , Podoviridae/classification , Podoviridae/genetics , Podoviridae/ultrastructure , Russia , Siphoviridae/classification , Siphoviridae/genetics , Siphoviridae/ultrastructure , Treatment Outcome
4.
Langmuir ; 29(1): 38-49, 2013 Jan 08.
Article in English | MEDLINE | ID: mdl-23214931

ABSTRACT

The importance of surfactant self-assemblies in foam stabilization is well-known. The aim of the current study was to investigate the self-assemblies of the nonionic surfactant polyglycerol ester (PGE) in bulk solutions, at the interface and within foams, using a combined approach of small-angle neutron scattering, neutron reflectivity, and electron microscopy. PGE bulk solutions contain vesicles as well as open lamellar structures. Upon heating of the solutions the lamellar spacing increases, with significant differences in the presence of NaCl or CaCl(2) as compared to the standard solution. The adsorption of the multilamellar structures present in the bulk solutions lead to a multilayered film at the air-water interface. The ordering within this film was increased as a result of a 20% area compression mimicking a coalescence event. Finally, PGE foams were shown to be stabilized not only by strong interfacial films but also by agglomerated self-assemblies within the interstitial areas of the foams.

5.
Macromol Biosci ; 4(7): 639-48, 2004 Jul 14.
Article in English | MEDLINE | ID: mdl-15468257

ABSTRACT

The present work discusses the grafting by electron beam irradiation of poly(ethylene oxide) (PEO) star-shaped polymers onto porous expanded polytetrafluoroethylene (EXPTFE) surfaces. The resulting materials are intended to combine the good biocompatible properties of PEO with the outstanding mechanical properties of PTFE. The star-shaped PEOs were synthesized via anionic polymerization. 3 Mev electron beam irradiation was applied to graft these PEO stars onto porous EXPTFE surfaces. The hydrophobic EXPTFE surface had to be pre-modified with N-vinylpyrrolidone. ESCA was used to quantify the amount of grafted star-shaped PEO. Unmodified EXPTFE surfaces are well known, when implanted in a body, to be rapidly covered by a layer of cells and fibrin. The EXPTFE coated with PEO were implanted in the peritoneal cavity of rats (or under the back skin). This implantation did not induce any inflammation reactions and SEM analysis had attested the absence of adsorbed cells and fibrin. The glucose diffusion properties of these membranes were studied by a lag time analysis method and compared to those of pure PEO hydrogels. As expected, glucose diffuses through the hydrogel coated membrane and diffusion is not affected by the presence of the EXPTFE membrane.


Subject(s)
Glucose/metabolism , Hydrogel, Polyethylene Glycol Dimethacrylate/chemistry , Polyethylene Glycols/chemistry , Polytetrafluoroethylene/chemistry , Animals , Coated Materials, Biocompatible/chemistry , Microscopy, Electron, Scanning , Models, Chemical , Polyethylene Glycols/radiation effects , Rats , Surface Properties
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