Математичне моделювання стаціонарного теплопереносу в процесах випікання тонких плоских тістових заготовок

Розглянуто математичну модель стаціонарного теплопереносу в процесах випікання тонких плоских тістових заготовок. Проведено числове моделювання і аналіз стаціонарних температурних полів для нагрівальної плити і заготовки з точки зору забезпечення більшої рівномірності нагріву за різними напрямками із врахуванням частотних характеристик нагрівання.Mathematical model of stationary heat transfer for baking processes of thin flat pastry blanks are considered. Numerical modeling and analyze of stationary temperature fields for hot plane and blank are conducted with taking into account condition of regular heating for different directions and heating frequencies characteristics

Effect of grid section design on trawl size selectivity

Sorting grids are introduced in trawl fisheries to improve size selectivity and reduce the variability of results obtained with sorting devices constructed of netting e.g., codends. Grids are rigid or semi-rigid structures where the bar spacing defines the sizes of fish that can pass through. However, for size selection to occur, fish need to be oriented towards the grid in specific ways, which may depend on the netting construction where the grid is installed. In the Barents Sea gadoid trawl fishery, fishermen are allowed to use different netting configurations within the same type of grid, but it is unclear to which degree the performance of sorting grids depends on the construction characteristics of the netting section where they are installed. This study compares the size selective properties of a steel grid mounted in three different netting section configurations: 2-panel section, 4-panel section, and 4-panel section with a modified lifting panel. Overall, the results of the study demonstrate that the 2-panel configuration performs better than the two 4-panel configurations tested. The differences were smaller when the 2-panel and the 4-panel section with a modified lifting panel were compared. Specifically, the grid contact probability for haddock with the 2-panel configuration was 0.92 (0.90 – 0.95) and significantly higher than for the 4-panel configuration, which was estimated to be 0.82 (0.77 – 0.89). For cod, the grid contact probability between the different configurations did not vary more than 6% and the differences were not significant. The 4-panel configuration led to significantly higher retention of cod between 40 to 60 cm and haddock between 20 and 54 cm than the 2-panel configuration. The results also show that despite having been assumed to provide constant size selectivity, the performance of sorting grids is sensitive to relatively small design changes in the section where they are mounted

Productivity and mortality of laying hens in aviaries: a systematic review

A systematic review of investigations on productivity, mortality and cannibalism of laying hens housed in aviaries is presented. In Part One we reviewed the studies that compared these parameters between laying hens housed in aviaries and in conventional cages. In Part Two we investigated the relative impact of strain, beak trimming and rearing condition on productivity and mortality in aviaries. The comparative analysis revealed that aviary hens consumed 3.0 % more food than caged hens, and food conversion was 6.7 % higher in aviaries than in cages. On the other hand, the mortality rate and cannibalism rate did not differ significantly between the two housing systems. The analysis of causes of variation in productivity, mortality rate and cannibalism rate in aviaries revealed a strong effect of strain. Beak trimming was associated with a reduced prevalence of cannibalism rates but had no effect on overall mortality. It also reduced egg weight and food consumption. Early access to litter during the rearing period had a positive effect on egg weight; egg mass, food conversion and mortality rate. In conclusion, we found a slightly reduced productivity of aviaries in relation to cages although the mortality rates and the prevalence of cannibalism did not differ between these housing systems. To further improve productivity and reduce mortality of hens housed in aviaries we recommend the choice of suitable strains and the implementation of improved rearing conditions including early access to litte

Is there a limit to the potential effects of shortening lastridge ropes on the size selectivity of diamond mesh codends?

Shortening codend lastridge ropes can be an effective fishing gear modification to improve the size selection properties in diamond mesh codends. Lastridge ropes attached to codend selvedges withstand the longitudinal forces created by the catch building up and therefore, prevent the codend meshes from closing. However, the extent to which the lastridge ropes should be shortened to maximize the effect of this measure is unclear. Besides opening codend meshes, shortening lastridge ropes can also lead to net folding, which can potentially have negative consequences for size selectivity. In the present study, we tested the size selective properties of a 129 mm diamond mesh codend in three different configurations: 0 %, 15 % and 30 % shortened lastridge ropes. Selectivity data were collected for cod (Gadus morhua), haddock (Melanogrammus aeglefinus) and redfish (Sebastes spp.) in the Barents Sea gadoid bottom trawl fishery. Shortening the lastridge ropes by 15 % had a significant effect on the release efficiency of haddock between 35 and 50 cm, whereas to obtain a similar result for cod, the lastridge ropes had to be shortened by 30 %. However, the use of shortened lastridge ropes significantly increased the retention of fish below 35 cm for both species, especially when the lastridge ropes were shortened from 15 % to 30 %. The effect on redfish size selectivity was in general limited. Exploitation pattern indicators showed that there was no added benefit from shortening them further from 15 % to 30 % for any of the three species. This study concludes that, while shortening lastridge ropes can contribute to improved size selection of diamond mesh codends, reducing them beyond 15 % is not recommended because it can substantially increase the retention of undersized fish, probably due to net folding.publishedVersio

Managing size selectivity: the relevance of compulsory and alternative selection devices in the Northeast Atlantic bottom trawl fishery

Two decades of use of the compulsory selectivity gear configuration in the Northeast Atlantic bottom trawl fishery, which consists of a rigid sorting grid followed by a diamond mesh codend, have revealed problems with performance and efficiency. Size selectivity gear alternatives to this configuration are being pursued, and recent studies of codends with shortened lastridges have reported promising results. In this study, we compared the size selectivity and catch efficiency for cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) caught using a sorting grid with 55 mm bar spacing followed by a 130 mm knotted diamond mesh codend (i.e. the compulsory gear) that same configuration but considering only the catch in the 130 mm diamond mesh codend (regular codend), and an alternative knotless codend with shortened lastridge ropes and a thinner twine. We also addressed the question of whether size-selective gear is even needed to avoid exceeding the bycatch limits of the fishery. Our results demonstrated that the alternative codend improved size selectivity by reducing the loss of fish above minimum legal size (MLS), with a minor increase in the retention of fish below MLS, compared to the compulsory combined grid and codend configuration. The regular codend also reduced the loss of fish above MLS, but the retention of haddock below MLS approached the legal limit of 15% by number. Our results also showed that the abundance of cod below MLS in the fishing area during the trials was low. They also suggested that spatial and seasonal closures in combination with a flexible choice of selection device and modern monitoring tools could be an alternative to rigid enforcement of the use of selective fishing gear.publishedVersio

Ghost fishing efficiency by lost, abandoned or discarded pots in snow crab (Chionoecetes opilio) fishery

Marine pollution by lost, abandoned or otherwise discarded fishing gear (ALDFG) often has negative impact on the ecosystem through plastic pollution and continuous capture of marine animals, so-called “ghost fishing”. ALDFG in pot fisheries is associated with high ghost fishing risk. The snow crab (Chionoecetes opilio) pot fishery is conducted in harsh weather conditions increasing the risk of fishing gear loss. Due to plastic materials used in the pot construction, lost gear can most likely continue fishing for decades. This study presents a method to quantify ghost fishing efficiency relative to catch efficiency of actively fished pots. On average, the ghost fishing pots captured 8.29 % (confidence intervals: 4.33–13.73 %) target-sized snow crab compared to the actively fished pots, demonstrating that lost pots can continue fishing even when the bait is decayed. Given the large number of pots lost each year, the ghost fishing efficiency is a considerable challenge in this fishery.publishedVersio

Effect of the Nordmøre grid bar spacing on size selectivity, catch efficiency and bycatch of the Barents Sea Northern shrimp fishery

The introduction of the Nordmøre grid in shrimp trawls has reduced the bycatch of non-target species. In the Norwegian Northern shrimp (Pandalus borealis) fishery, the mandatory selective gear consists of a Nordmøre grid with 19 mm bar spacing combined with a 35 mm mesh size diamond mesh codend. However, fish bycatch in shrimp trawls remains a challenge and further modifications of the gear that can improve selectivity are still sought. Therefore, this study estimated and compared the size selectivity of Nordmøre grids with bar spacings of 17 and 21 mm. Further, the effect of applying these two grids on trawl size selectivity was predicted and compared to the legislated gear configuration. Experimental fishing trials were conducted in the Barents Sea where the bottom trawl fleet targets Northern shrimp. Results were obtained for the target species and two by-catch species: cod (Gadus morhua) and American plaice (Hippoglossoides platessoides). This study demonstrated that reducing bar spacing can significantly reduce fish bycatch while only marginally affecting catch efficiency of Northern shrimp. This is a potentially important finding from a management perspective that could be applicable to other shrimp fisheries where flexibility in the use of different grid bar spacings may be beneficial to maximize the reduction of unwanted bycatch while minimizing the loss of target species.publishedVersio

Comparative analysis of Ig and TCR gene rearrangements at diagnosis and at elapse of childhood precursor-B–ALL provides improved strategies for selection of stable PCR targets for monitoring of minimal residual disease

Immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements are excellent patient-specific polymerase chain reaction (PCR) targets for detection of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL), but they might be unstable during the disease course. Therefore, we performed detailed molecula