Tracking mite trophic interactions by multiplex PCR

BACKGROUND A thorough knowledge of trophic webs in agroecosystems is essential to achieve successful biological pest control. Phytoseiid mites are the most efficient natural enemies of tetranychid mites, which include several important pests worldwide. Nevertheless, phytoseiids may feed on other food sources including other microarthropods, plants and even other phytoseiids (intraguild predation), which can interfere with biological control services. Molecular gut content analysis is a valuable tool for characterizing trophic interactions, mainly when working on microarthropods such as mites. We have designed new primers for Phytoseiidae, Tetranychidae and Thysanoptera identification and they have been multiplexed in a polymerase chain reaction (PCR) together with universal plant primers. Additionally, we have estimated prey DNA detectability success over time (DS50) considering the most probable events in Spanish citrus orchards: the phytoseiid Euseius stipulatus as a predator, the phytoseiid Phytoseiulus persimilis as intraguild prey, and the thrips Frankliniella occidentalis and Anaphothrips obscurus as alternative prey to Tetranychus urticae. RESULTS The designed multiplex PCR allows the identification of phytoseiids (both predator and intraguild prey) and detects alternative food sources mentioned above in the gut of the phytoseiid predator. DS50 for E. stipulatus as the predator were 1.3, 2.3 and 18.7 h post feeding for F. occidentalis, A. obscurus and P. persimilis as prey, respectively. CONCLUSION Tracking of the trophic relationships within the citrus acarofauna, and the unveiling of the role of alternative food sources will pave the way for enhancing T. urticae biological control. This multiplex PCR approach could be applicable for these purposes in similar agroecosystems

Preservation of phytosterol and PUFA during ready-to-eat lettuce shelf-life in active bio-package

Natural preservatives are used in food packages to improve the shelf life of perishable products. Carvacrol and thymol, the main components of oregano essential oil (OEO), are used in active packaging due to their antimicrobial and antioxidant properties. Here, the effect of a bioactive polylactic acid (PLA)/polybutylene succinate (PBS) package in the conservation of lettuce compounds with dietetic value is studied. Analytical pyrolysis (Py- GC/MS) was used to detect changes in dietary components such are phytosterols (PHSTs) and polyunsaturated fatty acids (PUFAs) after 1, 4 and 8 days of packaged in PLA/PBS (95:5%) films containing different OEO concentrations (2–10%). Lettuce PUFAs and PHSTs content decreased when packed in films without OEO. However, when packed in films containing 5 and 10% OEO, these bioactive components were preserved during the estimated lettuce shelf life, for up to 8 days of storage

Antimicrobial Properties of Ethylene Vinyl Alcohol/Epsilon-Polylysine Films and Their Application in Surimi Preservation

[EN] Polymer films based on ethylene vinyl copolymers (EVOH) containing a 29 % (EVOH 29) and a 44 % molar percentage of ethylene (EVOH 44), and incorporating epsilon-polylysine (EPL) at 0 %, 1 %, 5 % and 10 % were successfully made by casting. The optical properties and the amount of EPL released from the films to phosphate buffer at pH 7.5 were evaluated, films showing great transparency and those of EVOH 29 copolymer releasing a greater amount of EPL. The antimicrobial properties of the resulting films were tested in vitro against different foodborne microorganisms and in vivo in surimi sticks. With regard to the antimicrobial capacity tested in vitro in liquid medium at 37 A degrees C and 4 A degrees C against Listeria monocytogenes and Escherichia coli over a period of 72 h, films showed a considerable growth inhibitory effect against both pathogens, more notably against L. monocytogenes, and being EVOH 29 more effective than EVOH 44 films. At 37 A degrees C, total growth inhibition was observed for EVOH 29 films incorporating 10 % EPL against both microorganisms whereas the copolymer EVOH 44 did show total inhibition against L. monocytogenes and the growth of E. coli was reduced by 6.64 log units. At 4 A degrees C, no film was able to inhibit completely bacterial growth. Scanning electron microscopy micrographs showed corrugated cell surfaces with blisters and bubbles, and collapse of the cells appearing shorter and more compact after treatment with EPL. Finally, the films were successfully used to increase the shelf life of surimi sticks. The results show the films developed have a great potential for active food packaging applications.The authors acknowledge the financial support of the Spanish Ministry of Economy and Competitiveness, projects AGL2012-39920-C03-01, and fellowship funding for V. M.-G.Muriel-Galet, V.; Lopez-Carballo, G.; Gavara Clemente, R.; Hernández-Muñoz, P. (2014). Antimicrobial Properties of Ethylene Vinyl Alcohol/Epsilon-Polylysine Films and Their Application in Surimi Preservation. Food and Bioprocess Technology. 7(12):3548-3559. https://doi.org/10.1007/s11947-014-1363-1S35483559712Adams, M. R., & Moss, M. O. (2008). Food microbiology. UK: The Royal Society of Chemistry Cambridge.Aucejo, S., Catala, R., & Gavara, R. (2000). Interactions between water and EVOH food packaging films. Food Science and Technology International, 6(2), 159–164.Brandt, A. L., Castillo, A., Harris, K. B., Keeton, J. T., Hardin, M. D., & Taylor, T. M. (2010). Inhibition of Listeria monocytogenes by food antimicrobials applied singly and in combination. Journal of Food Science, 75(9), 557–563.Buchanan, R. L., & Doyle, M. P. (1997). Foodborne disease significance of Escherichia coli O157:H7 and other enterohemorrhagic E-coli. Food Technology, 51(10), 69–76.Chang, S.-S., Lu, W.-Y. W., Park, S.-H., & Kang, D.-H. (2010). Control of foodborne pathogens on ready-to-eat roast beef slurry by epsilon-polylysine. International Journal of Food Microbiology, 141(3), 236–241.Chang, Y., McLandsborough, L., & McClements, D. J. (2012). Cationic antimicrobial (epsilon-polylysine)-anionic polysaccharide (Pectin) interactions: influence of polymer charge on physical stability and antimicrobial efficacy. Journal of Agricultural and Food Chemistry, 60(7), 1837–1844.Chi-Zhang, Y. D., Yam, K. L., & Chikindas, M. L. (2004). Effective control of Listeria monocytogenes by combination of nisin formulated and slowly released into a broth system. International Journal of Food Microbiology, 90(1), 15–22.Coton, M., Denis, C., Cadot, P., & Coton, E. (2011). Biodiversity and characterization of aerobic spore-forming bacteria in surimi seafood products. Food Microbiology, 28(2), 252–260.FAO (2005) Further processing of fish Fisheries and Aquaculture Department, Rome. Updated 27 May 2005 Retrieved 14 March 2011.FDA (2004) Agency reponse letter GRAS Notice No. GRN 00135.Gambarin, P., Magnabosco, C., Losio, M. N., Pavoni, E., Gattuso, A., Arcangeli, G., et al. (2012). Listeria monocytogenes in ready-to-rat seafood and potential hazards for the consumers. International Journal of Microbiology, 2012, 497–635.Geornaras I, Yoon Y., Belk K. E., Smith G. C., Sofos J. N. (2007). Antimicrobial activity of epsilonpolylysine against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in various food extracts. Journal of Food Science, 72(8), M330–4.Gunlu, A., & Koyun, E. (2013). Effects of vacuum packaging and wrapping with chitosan-based edible film on the extension of the shelf life of sea bass (Dicentrarchus labrax) fillets in cold storage (4 A degrees C). Food and Bioprocess Technology, 6(7), 1713–1719.Hiraki, J. (1995). Basic and applied studies on ε-polylysine. Journal of Antibacterial Antifungal Agents Japan, 23, 349–493.Hiraki, J. (2000). ε-Polylysine, its development and utilization. Fine Chemistry, 29, 18–25.Hiraki, J., Ichikawa, T., Ninomiya, S., Seki, H., Uohama, K., Kimura, S., et al. (2003). Use of ADME studies to confirm the safety of epsilon-polylysine as a preservative in food. Regulatory Toxicology and Pharmacology, 37(2), 328–340.Ho, Y. T., Ishizaki, S., & Tanaka, M. (2000). Improving emulsifying activity of epsilon-polylysine by conjugation with dextran through the Maillard reaction. Food Chemistry, 68(4), 449–455.Huss, H. H., Jorgensen, L. V., & Vogel, B. F. (2000). Control options for Listeria monocytogenes in seafoods. International Journal of Food Microbiology, 62(3), 267–274.Kaneko, K., Hayashidani, H., Ohtomo, Y., Kosuge, J., Kato, M., Takahashi, K., et al. (1999). Bacterial contamination of ready-to-eat foods and fresh products in retail shops and food factories. Journal of Food Protection, 62(6), 644–649.Kang, E. T., Tan, K. L., Kato, K., Uyama, Y., & Ikada, Y. (1996). Surface modification and functionalization of polytetrafluoroethylene films. Macromolecules, 29(21), 6872–6879.Li, J., Han, Q., Chen, W., & Ye, L. (2012). Antimicrobial activity of Chinese bayberry extract for the preservation of surimi. Journal of the Science of Food and Agriculture, 92(11), 2358–2365.Lopez de Dicastillo, C., Nerin, C., Alfaro, P., Catala, R., Gavara, R., & Hernandez-Munoz, P. (2011). Development of new antioxidant active packaging films based on ethylene vinyl alcohol copolymer (EVOH) and green tea extract. Journal of Agricultural and Food Chemistry, 59(14), 7832–7840.Lopez-de-Dicastillo, C., Alonso, J. M., Catala, R., Gavara, R., & Hernandez-Munoz, P. (2010). Improving the antioxidant protection of packaged food by incorporating natural flavonoids into ethylene-vinyl alcohol copolymer (EVOH) dilms. Journal of Agricultural and Food Chemistry, 58(20), 10958–10964.Lopez-de-Dicastillo, C., Pezo, D., Nerin, C., Lopez-Carballo, G., Catala, R., Gavara, R., et al. (2012). Reducing oxidation of foods through antioxidant active packaging based on ethyl vinyl alcohol and natural flavonoids. Packaging Technology and Science, 25(8), 457–466.M100-S22 (2012) Performance Standards for Antimicrobial Susceptibility Testing: Eighteenth Informational Supplement. Clinical and Laboratory Standards Institute. Advancing Quality in Health Care Testing. Vol. 32 No. 3. Replaces M100-S21 . Vol. 31 No. 1Mead, P. S., & Griffin, P. M. (1998). Escherichia coli O157:H7. Lancet, 352(9135), 1207–1212.Miya, S., Takahashi, H., Ishikawa, T., Fujii, T., & Kimura, B. (2010). Risk of Listeria monocytogenes xontamination of raw ready-to-eat seafood products available at retail outlets in Japan. Applied and Environmental Microbiology, 76(10), 3383–3386.Muriel-Galet, V., Cerisuelo, J. P., Lopez-Carballo, G., Lara, M., Gavara, R., & Hernandez-Munoz, P. (2012a). Development of antimicrobial films for microbiological control of packaged salad. International Journal of Food Microbiology, 157(2), 195–201.Muriel-Galet, V., Lopez-Carballo, G., Gavara, R., & Hernandez-Munoz, P. (2012b). Antimicrobial food packaging film based on the release of LAE from EVOH. International Journal of Food Microbiology, 157(2), 239–244.Muriel-Galet, V., Cerisuelo, J. P., Lopez-Carballo, G., Aucejo, S., Gavara, R., & Hernandez-Munoz, P. (2013a). Evaluation of EVOH-coated PP films with oregano essential oil and citral to improve the shelf-life of packaged salad. Food Control, 30(1), 137–143.Muriel-Galet, V., López-Carballo, G., Hernández-Muñoz, P., & Gavara, R. (2013b). Characterization of ethylene–vinyl alcohol copolymer containing lauril arginate (LAE) as material for active antimicrobial food packaging. Food Packaging and Shelf Life, 1, 10–17.Park, J. W. (2014). Surimi and surimi seafood. Boca Raton: CRC Press.Shima, S., & Sakai, H. (1977). Polylysine produced by Streptomyces. Agricultural and Biological Chemistry, 41(9), 1807–1809.Shima, S., Matsuoka, H., Iwamoto, T., & Sakai, H. (1984). Antimicrobial action of epsilon-poly-l-lysine. Journal of Antibiotics, 37(11), 1449–1455.Singh, R. K., & Balange, A. K. (2005). Characteristics of pink perch (Nemipterus japonicus) surimi at frozen temperature. Journal of Food Processing and Preservation, 29(1), 75–83.Suppakul, P., Miltz, J., Sonneveld, K., & Bigger, S. W. (2003). Active packaging technologies with an emphasis on antimicrobial packaging and its applications. Journal of Food Science, 68(2), 408–420.Ting, H. Y., Ishizaki, S., & Tanaka, M. (1999). Epsilon-polylysine improves the quality of surimi products. Journal of Muscle Foods, 10(4), 279–294.Tzschoppe, M., Martin, A., & Beutin, L. (2012). A rapid procedure for the detection and isolation of enterohaemorrhagic Escherichia coli (EHEC) serogroup O26, O103, O111, O118, O121, O145 and O157 strains and the aggregative EHEC O104:H4 strain from ready-to-eat vegetables. International Journal of Food Microbiology, 152(1–2), 19–30.Uchida, E., Uyama, Y., & Ikada, Y. (1993). Sorption of low-molecular-weight anions into thin polycation layers grafted onto a film. Langmuir, 9(4), 1121–1124.Unalan, I. U., Ucar, K. D. A., Arcan, I., Korel, F., & Yemenicioglu, A. (2011). Antimicrobial potential of polylysine in edible films. Food Science and Technology Research, 17(4), 375–380.Venugopal, V., & Shahidi, F. (1995). Value-added products from underutilized fish species. Critical Reviews in Food Science and Nutrition, 35(5), 431–453.Zambuchini, B., Fiorini, D., Verdenelli, M. C., Orpianesi, C., & Ballini, R. (2008). Inhibition of microbiological activity during sole (Solea solea L.) chilled storage by applying ellagic and ascorbic acids. LWT--Food Science and Technology, 41(9), 1733–1738.Zinoviadou, K. G., Koutsoumanis, K. P., & Biliaderis, C. G. (2010). Physical and thermo-mechanical properties of whey protein isolate films containing antimicrobials, and their effect against spoilage flora of fresh beef. Food Hydrocolloids, 24(1), 49–59

Bioluminescence Imaging of Angiogenesis in a Murine Orthotopic Pancreatic Cancer Model

Angiogenesis is essential for physiological processes as well as for carcinogenesis. New approaches to cancer therapy include targeting angiogenesis. One target is VEGF-A and its receptor VEGFR2. In this study, we sought to investigate pancreatic cancer angiogenesis in a genetically modified VEGFR2-luc-KI mouse

Gender gaps in education

This chapter reviews the growing body of research in economics which concentrates on the education gender gap and its evolution, over time and across countries. The survey first focuses on gender differentials in the historical period that roughly goes from 1850 to the 1940s and documents the deep determinants of the early phase of female education expansion, including preindustrial conditions, religion, and family and kinship patterns. Next, the survey describes the stylized facts of contemporaneous gender gaps in education, from the 1950s to the present day, accounting for several alternative measures of attainment and achievement and for geographic and temporal differentiations. The determinants of the gaps are then summarized, while keeping a strong emphasis on an historical perspective and disentangling factors related to the labor market, family formation, psychological elements, and societal cultural norms. A discussion follows of the implications of the education gender gap for multiple realms, from economic growth to family life, taking into account the potential for reverse causation. Special attention is devoted to the persistency of gender gaps in the STEM and economics fields

Gender Gaps in Education

This chapter reviews the growing body of research in economics which concentrates on the education gender gap and its evolution, over time and across countries. The survey first focuses on gender differentials in the historical period that roughly goes from 1850 to the 1940s and documents the deep determinants of the early phase of female education expansion, including preindustrial conditions, religion, and family and kinship patterns. Next, the survey describes the stylized facts of contemporaneous gender gaps in education, from the 1950s to the present day, accounting for several alternative measures of attainment and achievement and for geographic and temporal differentiations. The determinants of the gaps are then summarized, while keeping a strong emphasis on an historical perspective and disentangling factors related to the labor market, family formation, psychological elements, and societal cultural norms. A discussion follows of the implications of the education gender gap for multiple realms, from economic growth to family life, taking into account the potential for reverse causation. Special attention is devoted to the persistency of gender gaps in the STEM and economics fields

Deep learning-based phenotyping reclassifies combined hepatocellular-cholangiocarcinoma.

Primary liver cancer arises either from hepatocytic or biliary lineage cells, giving rise to hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICCA). Combined hepatocellular- cholangiocarcinomas (cHCC-CCA) exhibit equivocal or mixed features of both, causing diagnostic uncertainty and difficulty in determining proper management. Here, we perform a comprehensive deep learning-based phenotyping of multiple cohorts of patients. We show that deep learning can reproduce the diagnosis of HCC vs. CCA with a high performance. We analyze a series of 405 cHCC-CCA patients and demonstrate that the model can reclassify the tumors as HCC or ICCA, and that the predictions are consistent with clinical outcomes, genetic alterations and in situ spatial gene expression profiling. This type of approach could improve treatment decisions and ultimately clinical outcome for patients with rare and biphenotypic cancers such as cHCC-CCA