Establishment of surface functionalization methods for spore-based biosensors and implementation into sensor technologies for aseptic food processing

Aseptic processing has become a popular technology to increase the shelf-life of packaged products and to provide non-contaminated goods to the consumers. In 2017, the global aseptic market was evaluated to be about 39.5 billion USD. Many liquid food products, like juice or milk, are delivered to customers every day by employing aseptic filling machines. They can operate around 12,000 ready-packaged products per hour (e.g., Pure-Pak® Aseptic Filling Line E-PS120A). However, they need to be routinely validated to guarantee contamination-free goods. The state-of-the-art methods to validate such machines are by means of microbiological analyses, where bacterial spores are used as test organisms because of their high resistance against several sterilants (e.g., gaseous hydrogen peroxide). The main disadvantage of the aforementioned tests is time: it takes at least 36-48 hours to get the results, i.e., the products cannot be delivered to customers without the validation certificate. Just in this example, in 36 hours, 432,000 products would be on hold for dispatchment; if more machines are evaluated, this number would linearly grow and at the end, the costs (only for waiting for the results) would be considerably high. For this reason, it is very valuable to develop new sensor technologies to overcome this issue. Therefore, the main focus of this thesis is on the further development of a spore-based biosensor; this sensor can determine the viability of spores after being sterilized with hydrogen peroxide. However, the immobilization strategy as well as its implementation on sensing elements and a more detailed investigation regarding its operating principle are missing. In this thesis, an immobilization strategy is developed to withstand harsh conditions (high temperatures, oxidizing environment) for spore-based biosensors applied in aseptic processing. A systematic investigation of the surface functionalization’s effect (e.g., hydroxylation) on sensors (e.g., electrolyte-insulator semiconductor (EIS) chips) is presented. Later on, organosilanes are analyzed for the immobilization of bacterial spores on different sensor surfaces. The electrical properties of the immobilization layer are studied as well as its resistance to a sterilization process with gaseous hydrogen peroxide. In addition, a sensor array consisting of a calorimetric gas sensor and a spore-based biosensor to measure hydrogen peroxide concentrations and the spores’ viability at the same time is proposed to evaluate the efficacy of sterilization processes

DRAFT Report:Community Systems Strengthening Toward a Research Agenda

Communities have a long history of acting to preserve and promote the health of their members. Public health researchers, programmers, and funders are increasingly recognizing that community involvement is essential to improving health, especially among populations that are disproportionately affected by HIV. The Global Fund to fight AIDS, Tuberculosis and Malaria, together with civil society organizations and other development partners, created the Community Systems Strengthening (CSS) Framework to help Global Fund applicants frame, define, and quantify efforts to strengthen community contributions engagement (Global Fund 2011). Although the use of a CSS approach in health programming implementation shows promise, it lacks a theoretical framework to guide collaborations with communities. Additionally, it suffers from a paucity of program designs and evaluation practices, an incomplete evidence-based rationale for investing in CSS, and imprecise definitions (e.g., what is meant by “community” and “CSS”).The purpose of this paper is to highlight promising areas for future research related to CSS. Toward this objective, we propose to lay a foundation for a CSS research agenda by using theories and approaches relevant to CSS, reinforced with evidence from projects that employ similar approaches

Merecemos Saber/ We Deserve to Know

Safe Ag Safe Schools, a coalition of 50-plus organizations works with the community to reduce pesticide exposure in Monterey County. Although pesticides are used to kill and repel pests, pesticides put human health at risk. Despite the efforts addressing pesticides issues, Spanish speaking individuals are unaware of what those issues are. Merecemos Saber/ We Deserve to Know is an educational intervention aimed to increase Spanish speaking individuals’ knowledge and awareness about pesticide issues. This project included an educational intervention, mapping of expected pesticide applications near Greenfield schools, and a presentation conducted at the Community Forum on Pesticides in Greenfield City Council Chambers. Thirty-five participants observed three maps about 2018-2019 expected pesticide applications near the schools. Qualitative interviews indicated that participants found the maps useful to understand pesticide applications near the schools. Overall, more maps are needed to illustrate pesticide applications near Monterey County schools