In this study, a changepoint model, which can detect either a mean shift or a trend change when accounting for autocorrelation in short time-series, was investigated with simulations and a new method is proposed. The changepoint hypotheses were tested using a likelihood ratio test. The test statistic does not follow a known distribution and depends on the length of the time-series and the autocorrelation. The results imply that it is not possible to detect autocorrelation and that the estimate of the autocorrelation parameter is biased. It is therefore recommended to use critical values from the empirical distribution for a fixed autocorrelation.
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Atlantic sea cucumber (Cucumaria frondosa) is a marine invertebrate that occurs naturally in the North Atlantic. Its collagen rich body walls make the sea cucumber an appreciated food source in many countries. The heteroglycans derived from the cartilage of Atlantic sea cucumbers have shown potential as a source of bioactive compounds, but further investigation is needed to confirm this hypothesis. The objectives of this work were to test the immunomodulating properties of heteroglycan fractions (FCFs) derived from Atlantic sea cucumbers toward phorbol 12-myristate 13-acetate (PMA) differentiated THP-1 macrophages. Oxygen Radical Absorbance Capacity (ORAC) was determined and cell culture media was collected and analyzed for the presence of pro-inflammatory and anti-inflammatory cytokines (TNF-α, IL-6, and IL-10). FCFs toxicity toward macrophages was evaluated by light microscopy and confirmed by XTT proliferation assay. Heteroglycans derived from cartilage of Atlantic sea cucumber showed immunomodulatory activity in THP-1 macrophages. FCF-1, −2, and - 3) at concentrations 0.1–100 µg / mL induced levels of TNF-α, IL-6, and IL-10 proofing their bioactivity towards THP-1 macrophages. However, fractions of FCF-1 and FCF-2 may have induced oxidative stress in the macrophages, which possibly could lead to decreased cellular viability.
This study utilized Life Cycle Assessment (LCA) to quantify the environmental impacts of 1 kg of live-weight Arctic char, cultivated in an Icelandic land-based aquaculture farm. The functional unit included assessments of three different feed types; standard feed with high inclusion levels of marine ingredients (Conv.), experimental feed with high inclusion levels of agricultural ingredients (ECO) and a hypothetical Black soldier fly larvae based feed (BSF). Results of the study indicated that the feed production causes the greatest environmental impacts from all feed types considered. The Black soldier fly based feed demonstrated the best environmental performance of the three feed types. Furthermore, it can be concluded that by increasing agriculture based ingredients at the cost of marine based ingredients, a better environmental performance can be reached. This study demonstrated the importance of feed production for aquaculture in terms of environmental impacts and showed that byoptimizing feed consumption, reducing the amount of fishmeal and fish oil and even creating new types of feed from novel ingredients, the overall impacts of aquaculture can be greatly reduced .
The thermophile Rhodothermus marinus produces extracellular polysaccharides (EPSs) that forms a distinct cellular capsule. Here, the first data on EPS production in strains DSM4252T and MAT493 are reported and compared. Cultures of both strains, supplemented with either glucose, sucrose, lactose or maltose showed that the EPS were produced both in the exponential and stationary growth phase and that production in the exponential phase was boosted by maltose supplementation, while stationary phase production was boosted by lactose . The latter was higher, resulting in 8.8 (DSM4252T) and 13.7 mg EPS / g cell dry weight (MAT493) in cultures in marine broth supplemented with 10 g / L lactose. The EPSs were heteropolymeric with an average molecular weight of 8 × 104 Da and different monosaccharides, including arabinose and xylose. FT-IR spectroscopy revealed presence of hydroxyl, carboxyl, N-acetyl, amine, and sulfate ester groups, showing that R. marinus produces unusual sulfated EPS with high arabinose and xylose content.
Interruption of a temperature-controlled cold-chain, is a common problem during transportation and storage of food. The objective of the study was to investigate stability of Atlantic mackerel as subjected to temperature abuse (−12 ° C for 1 month) followed by storage at a constant temperature (−25 ° C) for 9 months, and compared to stable storage (- 25 ° C). Diversity in composition of the raw material as affected by feeding state was investigated. Evaluation of quality attributes (gaping, peritoneum) was performed, as well as lipid hydroperoxide, thiobarbituric reactive substances, and free fatty acids. The temperature abuse resulted in increased gap and peritoneum deterioration, lipid degradation compared to fish stored at a constant temperature. Results indicated that fish caught in July has a higher amount of polyunsaturated and saturated fatty acids, but less monounsaturated fatty acids than fish caught in September. Therefore, fish from September was more prone to degradation during storage than fish caught in July.
The aim of this study was to investigate the effects of ambient temperatures (9, 16, 21 ° C) and holding time (0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 h) on rate and quantity of temperature changes and drip losses for whitefish fillets. Different types of fillets were used for the experiment, fresh deepwater redfish (Sebastes mentella) fillets (105 g) and two sizes of saithe (Pollachius virens) fillets (289 g and 634 g). The fillet temperature increased with time, and more rapidly at higher ambient temperatures, particularly with smaller sized fillets. Similarly, the rate and quantity of drip formation were affected by all experimental factors. The effects decreased (p <0.05) in the following order: holding time> type of fillets> ambient temperature. The rate of changes in both temperature and drip loss were greater during the first hour of holding but leveled off with longer holding time. Results indicated that time-temperature abuse, even during relatively short (<1 h) exposure of fillets, may lead to significant economic losses due to weight reduction of the products.
Although grass dominates most agricultural systems in the North Atlantic region (NAR), spring barley is the most important cereal and is used for animal feed and food and drink products. Recent changes in climate have resulted in warmer conditions across the NAR which have major implications for crop production. In this paper, we investigate the thermal requirement of spring barley in the region and use the results to examine the effects of recent trends in temperature and rainfall on barley cultivation, based on 11 regional meteorological sites. At these sites, between 1975 and 2015, we found significant warming trends for several months of the cropping season and significant trends for increases in the cropping season degree days (CSDD). In recent years, this has resulted in an increased proportion of years when the estimated minimum thermal requirement for barley has been met at sites above about 60 ° N. However, annual variations in CSDD are large and years still occur at these sites where this is insufficient. While warming could potentially allow an earlier start and later end to the cropping season, it is likely that high rainfall at maritime sites, and low rainfall at continental sites, will limit the ability of growers to benefit from this. Warming is considered to have been one of the main factors contributing to the large expansion of the area of barley cultivated in Iceland since the 1990s.
We describe an emerging initiative - the 'Functional Annotation of All Salmonid Genomes' (FAASG), which will leverage the extensive trait diversity that has evolved since a whole genome duplication event in the salmonid ancestor, to develop an integrative understanding of the functional genomic basis of phenotypic variation. The outcomes of FAASG will have diverse applications, ranging from improved understanding of genome evolution, to improving the efficiency and sustainability of aquaculture production, supporting the future of fundamental and applied research in an iconic fish lineage of major societal importance.
The effects of dietary lipid oxidation on fish are diverse and contradictory. In this study, herring oil was oxidized to five different levels (peroxide values (POV): 20.44, 182.97, 56.12, 33.27 and 0.00 meq kg- 1) and used to formulate five experimental diets. Juvenile Arctic charr (Salvelinus alpinus, mean body mass ± SD: 2.41 ± 0.11 g) were reared on the five diets for 67 days. In another experiment, juvenile Nile tilapia (Oreochromis niloticus) (1.71 ± 0.40 g) were reared on three diets formulated with oxidized oils having POV of 19.55, 447.27 and 32.72 respectively, for 90 days. Growth responses were monitored in quadruplicate groups of 60 individuals of Arctic charr and 100 for Nile tilapia, respectively. The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were only studied in Arctic charr.
At the end of the study, the Arctic charr group reared on a diet with oils in the primary oxidation state had significantly lower body mass and specific growth rate, but higher hepatosomatic index compared to the rest of the groups. The activities of CAT and GPx increased with dietary lipid oxidation while that of SOD remained fairly stable. In Nile tilapia, both final body mass and condition factor were significantly lower in the group fed fresh oil than in the groups fed oxidized oils. Fillet lipid content decreased with lipid oxidation while ash and protein did not differ amongst tilapia groups. The results suggest that Arctic charr are more susceptible to lipid oxidation than are Nile tilapia. These differences may be the result of species differences in tolerance to oxidized lipids, variable lipid intake or access to vitamin E / tocopherol in feed.
Unstable conditions are commonly encountered during industrial storage and transportation of frozen fish. Temperature stress and fluctuations may increase the amount of unfrozen water in the muscle and enzymatic activity and lipid oxidation can thus still take place during frozen storage. The aim of this study was to investigate the changes of characteristics of different muscle types of herring at unstable modeled conditions during storage and transportation. Compositional changes, lipid oxidation and lipid hydrolysis were monitored in light and dark muscle of Atlantic herring (Clupea harengus), during frozen storage, as affected by temperature stress (samples were stored at - 25 ° C for 2 months, then stressed at - 12 ° C for 1 month, followed by storage at a stable - 25 ° C for the remaining storage duration ), and compared to samples stored at a stable - 25 ° C for 14 months. The dark muscle was more sensitive to lipid oxidation than the light muscle, leading to faster degradation. Increased lipid oxidation and lipid hydrolysis were observed in temperature-stressed samples of both muscle types. The study demonstrated the importance of avoiding temperature stress during industrial frozen storage and transportation to improve the quality and shelf life of frozen herring products. Removal of dark muscle by deep skinning could benefit both processors and customers regarding the shelf life and nutritional value of the light herring muscle.