35 research outputs found

    Food waste to new food: Risk assessment and microbial community analysis of anaerobic digestate as a nutrient source in hydroponic production of vegetables

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    In this study, the microbiological food safety of using anaerobic digestate as a fertilizer in hydroponic production of vegetables was evaluated. The used anaerobic digestate was a liquid residue obtained from the digestion of food waste in the production of biogas. Replacing the customary inorganic fertilizer used in hydroponic production with this recycled fertilizer (biofertilizer) could allow for sustainable urban food production close to retailers and consumers. However, in striving for circular food production, it is vital that the food safety of utilizing recycled resources is ensured. Especially in the application of hydroponic farming, where the nutrient loop is shorter than on arable land, a microbiological food safety risk assessment is crucial when adopting new and recycled fertilizers. The biofertilizer based on anaerobic digestate was therefore studied with regard to its microbial community (16S rRNA gene amplicon sequencing) during production of vegetables in a hydroponic system. The biofertilizer was also challenge tested with food borne pathogens (Salmonella enterica, Listeria monocytogenes and Bacillus cereus). Furthermore, the microbial activity of the biofertilizer was studied using isothermal calorimetry. The results showed that the microbial community of the biofertilizer changed distinctly through a necessary initial nitrification process, and that the most abundant genus was Mycobacterium. Deliberate contaminations with 5 log10 CFU mL−1 of either S. enterica or L. monocytogenes in the nitrified biofertilizer were no longer detectable with selective plating after 48 h of incubation at 20 °C. Selective plating for B. cereus revealed that the biofertilizer contained low levels (∼10 CFU mL−1) of the bacterium, and an inoculation of 5 log10 CFU mL−1 B. cereus decreased to these levels within 24 h of incubation at 20 °C. Analysis of the microbial activity of the biofertilizer indicated that the biofertilizer does not seem to support microbial activity without the addition of an external nutrient source that contains an accessible carbon source and trace elements. The type of biofertilizer investigated in this study is thus regarded as microbiologically safe for use in hydroponic cultivation. The constant presence of viable B. cereus, however, emphasizes the fundamental importance of continuous risk assessment in case of any modifications or supplementations of the biofertilizer, since it clearly can act as a reservoir for bacterial endospores

    A systematic review of the incidence of schizophrenia: the distribution of rates and the influence of sex, urbanicity, migrant status and methodology

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    BACKGROUND: Understanding variations in the incidence of schizophrenia is a crucial step in unravelling the aetiology of this group of disorders. The aims of this review are to systematically identify studies related to the incidence of schizophrenia, to describe the key features of these studies, and to explore the distribution of rates derived from these studies. METHODS: Studies with original data related to the incidence of schizophrenia (published 1965–2001) were identified via searching electronic databases, reviewing citations and writing to authors. These studies were divided into core studies, migrant studies, cohort studies and studies based on Other Special Groups. Between- and within-study filters were applied in order to identify discrete rates. Cumulative plots of these rates were made and these distributions were compared when the underlying rates were sorted according to sex, urbanicity, migrant status and various methodological features. RESULTS: We identified 100 core studies, 24 migrant studies, 23 cohort studies and 14 studies based on Other Special Groups. These studies, which were drawn from 33 countries, generated a total of 1,458 rates. Based on discrete core data for persons (55 studies and 170 rates), the distribution of rates was asymmetric and had a median value (10%–90% quantile) of 15.2 (7.7–43.0) per 100,000. The distribution of rates was significantly higher in males compared to females; the male/female rate ratio median (10%–90% quantile) was 1.40 (0.9–2.4). Those studies conducted in urban versus mixed urban-rural catchment areas generated significantly higher rate distributions. The distribution of rates in migrants was significantly higher compared to native-born; the migrant/native-born rate ratio median (10%–90% quantile) was 4.6 (1.0–12.8). Apart from the finding that older studies reported higher rates, other study features were not associated with significantly different rate distributions (e.g. overall quality, methods related to case finding, diagnostic confirmation and criteria, the use of age-standardization and age range). CONCLUSIONS: There is a wealth of data available on the incidence of schizophrenia. The width and skew of the rate distribution, and the significant impact of sex, urbanicity and migrant status on these distributions, indicate substantial variations in the incidence of schizophrenia

    Development of an international Core Outcome Set (COS) for best care for the dying person: study protocol

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    Background: In contrast to typical measures employed to assess outcomes in healthcare such as mortality or recovery rates, it is difficult to define which specific outcomes of care are the most important in caring for dying individuals. Despite a variety of tools employed to assess different dimensions of palliative care, there is no consensus on a set of core outcomes to be measured in the last days of life. In order to optimise decision making in clinical practice and comparability of interventional studies, we aim to identify and propose a set of core outcomes for the care of the dying person. Methods: Following the COMET initiative approach, the proposed study will proceed through four stages to develop a set of core outcomes: In stage 1, a systematic review of the literature will identify outcomes measured in existing peer reviewed literature, as well as outcomes derived through qualitative studies. Grey literature, will also be included. Stage 2 will allow for the identification and determination of patient and proxy defined outcomes of care at the end of life via quantitative and qualitative methods at an international level. In stage 3, from a list of salient outcomes identified through stages 1 and 2, international experts, family members, patients, and patient advocates will be asked to score the importance of the preselected outcomes through a Delphi process. Stage 4 consists of a face-to-face consensus meeting of in

    ULTRASTRUCTURE OF THE RAT THYMUS

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