Co-infection dynamics of a major food-borne zoonotic pathogen in chicken

A major bottleneck in understanding zoonotic pathogens has been the analysis of pathogen co-infection dynamics. We have addressed this challenge using a novel direct sequencing approach for pathogen quantification in mixed infections. The major zoonotic food-borne pathogen Campylobacter jejuni, with an important reservoir in the gastrointestinal (GI) tract of chickens, was used as a model. We investigated the co-colonisation dynamics of seven C. jejuni strains in a chicken GI infection trial. The seven strains were isolated from an epidemiological study showing multiple strain infections at the farm level. We analysed time-series data, following the Campylobacter colonisation, as well as the dominant background flora of chickens. Data were collected from the infection at day 16 until the last sampling point at day 36. Chickens with two different background floras were studied, mature ( treated with Broilact, which is a product consisting of bacteria from the intestinal flora of healthy hens) and spontaneous. The two treatments resulted in completely different background floras, yet similar Campylobacter colonisation patterns were detected in both groups. This suggests that it is the chicken host and not the background flora that is important in determining the Campylobacter colonisation pattern. Our results showed that mainly two of the seven C. jejuni strains dominated the Campylobacter flora in the chickens, with a shift of the dominating strain during the infection period. We propose a model in which multiple C. jejuni strains can colonise a single host, with the dominant strains being replaced as a consequence of strain-specific immune responses. This model represents a new understanding of C. jejuni epidemiology, with future implications for the development of novel intervention strategies

The Transition Towards a Fossil Free Freight Transport Sector – Policy Evaluations and Effects of Proposed Policy Instruments

The overall aim of this thesis is to improve the knowledge about how policy instruments can contribute to effective and efficient reductions of greenhouse gas emissions in the freight and maritime transport sectors. Paper I addresses this aim by analysing how policy evaluations contribute with information about whether policy instruments in the freight transport sector have been successful in achieving their targets and how to improve or correct already implemented ones. A meta-evaluation of ex-post climate policy evaluations is carried out, and by analysing the outcomes and quality of the evaluations, the study investigates whether estimated effects of policy instruments can be compared between evaluations and if the results are appropriate to use for evidence-based decision making. The study shows that there is a lack of systematic climate policy evaluation which hinders reliable conclusions about the effects of policy instruments. Consequently, there is a need for more systematic monitoring and evaluation of implemented policy instruments and the study suggests that evidence-based decision making can be improved by adjusting current policy evaluation guidelines and by introducing an evaluation obligation. Paper II addresses the overall aim by developing a modelling tool, referred to as the Swedish Energy Transition of Shipping (SETS) model, that can be used for policy scenario analyses of shipowners’ investment decisions in the Swedish maritime transport sector over the time period 2020-2045. The main contribution of the developed SETS model is that it can take into account data for individual ships and their operational patterns when estimating the impact of potential policy instruments. Hence, the model can contribute to an improved understanding of how proposed policy instruments can affect future greenhouse gas emission reductions in the maritime transport sector

Efficacy of insect larval meal to replace fish meal in juvenile barramundi, Lates calcarifer reared in freshwater

The present experiment was conducted to evaluate the efficacy of dietary protein from black soldier fly, Hermetia illucens, larval meal (BSFL) to replace fish meal (FM) protein in juvenile barramundi, Lates calcarifer. Larvae of black soldier fly were fed with the underutilised crop, sesbania, Sesbania grandiflora. Five isonitrogenous (44% crude protein) and isocaloric (16.0 kJ available energy/g) experimental diets were formulated to replace FM using processed BSFL meal at 0 (control), 25% (BSFL25), 50% (BSFL50), 75% (BSFL75) and 100% (BSFL100). Data for proximate and amino acid analysis suggested BSFL meal as an inferior protein ingredient than FM, but parallel to soybean meal. At the end of 8 weeks of fish feeding trial, there were no significant differences in the average weight gain (WG) and specific growth rate among the group of fish-fed control, BSFL25 and BSFL50 diets (P < 0.05). Although numerical differences were recorded in the fish whole-body proximate composition, crude protein and moisture content were not much affected by the different dietary treatments. Essential amino acids including arginine, histidine, lysine and methionine were found to be higher in the whole body of fish-fed BSFL100 diet. Broken line regression analysis of average WG showed an optimum FM replacement level of 28.4% with BSFL meal. Therefore, the present experiment clearly demonstrates that the maximal dietary inclusion level of BSFL meal as FM protein replacer for the optimum growth of juvenile barramundi reared in freshwater could be greater than 28.4% but less than 50%, without any adverse effects on the fish whole-body proximate and amino acid composition

A meta-evaluation of climate policy evaluations: findings from the freight transport sector

Knowledge about how implemented policy instruments have performed is important for designing effective and efficient policy instruments that contribute to reductions of greenhouse gas emissions. This paper carries out a meta-evaluation of ex-post evaluations of climate policy instruments in the freight transport sector. By analysing the outcomes and quality of evaluations, the aim is to identify whether estimated effects of policy instruments can be compared between evaluations and if the results are appropriate to use for evidence-based decision making. To analyse these aspects, commonly applied evaluation criteria are assessed and classified according to an assessment scale. We confirm that few ex-post evaluations are carried out and that there is a gap between evaluation theory and how ex-post policy evaluations are performed in practice, where evaluation criteria recommended in policy evaluation guidelines are found to often be neglected in evaluations. The result is a lack of systematic climate policy evaluation which hinders reliable conclusions about the effect of policy instruments. There is a need for more systematic monitoring and evaluation of implemented policy instruments and we suggest that evidence-based decision making can be improved by adjusting current policy evaluation guidelines and by introducing an evaluation obligation

Within-species variation in the gut microbiome of medaka (Oryzias latipes) is driven by the interaction of light intensity and genetic background

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Impact of Westernized Diet on Gut Microbiota in Children on Leyte Island

10.3389/fmicb.2017.00197Frontiers in Microbiology8FEB19

Gut microbiome biogeography in reindeer supersedes millennia of ecological and evolutionary separation

publishedVersionpublishedVersio

Assessment of the impact of wastewater and sewage sludge treatment methods on antimicrobial resistance. Scientific opinion of the Panel on Microbial Ecology of the Norwegian Scientific Committee for Food and Environment

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Assessment of the impact of wastewater and sewage sludge treatment methods on antimicrobial resistance. Scientific opinion of the Panel on Microbial Ecology of the Norwegian Scientific Committee for Food and Environment

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Surveillance of antimicrobial resistance in the environment - Scientific Opinion of the Panel on Microbial Ecology, Norwegian Scientific Committee for Food and Environment

publishedVersionpublishedVersio