196,421 research outputs found
Plasticity of thermal tolerance and associated gill transcriptome in ballan wrasse (Labrus bergylta)
No full textThermal condition has profound influence on physiology and behaviour of ballan wrasse (Labrus bergylta), a cleaner fish commonly deployed in salmon cages to control sea lice infection. To address knowledge gaps on the species thermal biology, critical thermal limits were determined by acclimating fish (21.5 ± 3.1 g, 10.5 ± 0.4 cm) at a range of temperatures (6, 10, or 14°C) found in its natural habitat on the west coast of Scotland for one week and subjecting them to ramping temperature (~0.3°C/min) until loss of equilibrium. Critical thermal maxima (CT max), minima (CT min), and thermal breadth values increased with acclimation temperature. Thermal tolerance polygon was constructed and showed the intrinsic (7.9 to 16.8°C) and acquired (3.4°C and 22.8°C) thermal tolerance zones, supporting the seasonal differences in behaviour and delousing efficacy of ballan wrasse deployed in salmon farms. Gill transcriptomic profiles of ballan wrasse were performed following thermal acclimation and subsequent exposure to CT max and CT min. Initial acclimation resulted in unique differentially expressed genes (DEGs) and enrichment of GO terms that were almost exclusively found in each acclimation group. Transcriptome response to CT max and CT min also varied between acclimation groups. CT max and CT min shared 0% DEGs at 6°C, 43% at 10°C, and 7% at 14°C, but some overlapping GO terms. This study is the first to investigate the thermal tolerance limits of ballan wrasse and provides new data into the plasticity of thermal tolerance limits and molecular response to thermal stimuli in fish
Video annotation and retrieval using ontologies and rule learning
No full textAn approach for automatic annotation and retrieval of video content uses semantic concept classifiers and ontologies to permit expanded queries to synonyms and concept specializations
Commander Ballan, officer on Bosquet's staff
No full textCommander Ballan, full-length portrait, standing, facing slightly left.Title transcribed from verso."Captain Thomas" written, then crossed out on verso. DLCRestricted access: Materials extremely fragile; Served by appointment only.Purchase; Frances M. Fenton; 1944.Forms part of: Roger Fenton Crimean War photograph collection
Effective Codebooks for Human Action Representation and Classification in Unconstrained Videos
No full textRecognition and classification of human actions for annotation of unconstrained video sequences has proven to be challenging because of the variations in the environment, appearance of actors, modalities in which the same action is performed by different persons, speed and duration and points of view from which the event is observed. This variability reflects in the difficulty of defining effective descriptors and deriving appropriate and effective codebooks for action categorization.
In this paper we propose a novel and effective solution to classify human actions in unconstrained videos. It improves on previous contributions through the definition of a novel local descriptor that uses image gradient and optic flow to respectively model the appearance and motion of human actions at interest point regions. In the formation of the codebook we employ radius-based clustering with soft assignment in order to create a rich vocabulary that may account for the high variability of human actions. We show that our solution scores very good performance with no need of parameter tuning. We also show that a strong reduction of computation time can be obtained by applying codebook size reduction with Deep Belief Networks with little loss of accuracy
Application of passive-acoustic telemetry to explore the behaviour of ballan wrasse (Labrus bergylta) and lumpfish (Cyclopterus lumpus) in commercial Scottish salmon sea-pens
No full textA passive-acoustic telemetry system was used for the first time for the fine-scale, three-dimensional tracking of individual cleaner fish in commercial Scottish salmon sea-pens in full commercial operation. The aim was to test the system performance and provide baseline data on the comparative distribution and swimming activity of individual ballan wrasse and lumpfish under standard farm practices with the long-term aim of informing stocking and husbandry strategies. In March 2015, wild ballan wrasse (Labrus bergylta) (115 ± 20 g; n = 13) and farmed lumpfish (Cyclopterus lumpus) (281 ± 42 g; n = 13) previously deployed in June–October 2014 were recaptured, implanted with acoustic tags pinging every 6–12 s and released into their original sea cage holding Atlantic salmon (Q2 2014; 2059 ± 35 g mean-weight). Control tags were deployed in cleaner fish hides to validate the system performance. Positional data from nine specimens per species were analysed from March 24th to June 1st 2015, during which time water temperature rose from 7.2 to 9.1 °C and water salinity averaged 26.8 ± 1.5 ppt at 4 m depth. The accuracy of the acoustic positions averaged 0.6 m across the three dimensions of all control tags and was < 1 m in 93% of all cases. Significant differences in the distribution and activity of ballan wrasse and lumpfish were observed. Ballan wrasses spent 60 ± 2% of the day-time at or below 15 m, were positioned at significantly shallower depths at night and seldom used the hides provided despite an apparent resting behaviour at the pen bottom and corners. In comparison, lumpfish spent over 80% of the time above 10 m, used hides extensively and preferentially at night (50.1 ± 2.1% at night), but to a lesser extent when the water temperature increased. The acoustic tracking system proved to be an effective tool for visualising cleaner fish behaviour under challenging farm conditions, and the study highlights the critical role of hides in cleaner fish husbandry. Overall, the study quantified species-specific cleaner fish distribution in salmon net-pens supporting distinct interactions with the salmon stock and seasonal behaviour profiles. The results support the current commercial strategy of using two cleaner fish species against sea lice and the need for species-specific management strategies to optimise delousing activity
Bacterial Communities of Ballan Wrasse (Labrus bergylta) Eggs at a Commercial Marine Hatchery
No full textBallan wrasse (Labrus bergylta, Ascanius 1767) are cleaner fish cultured in northern Europe to remove sea lice from farmed Atlantic salmon (Salmo salar, Linnaeus 1758). Despite increasing appreciation for the importance of the microbiota on the phenotypes of vertebrates including teleosts, the microbiota of wrasse eggs has yet to be described. Therefore, the aim of this present study was to describe the bacterial component of the microbiota of ballan wrasse eggs shortly after spawning and at 5 days, once the eggs had undergone a routine incubation protocol that included surface disinfection steps in a common holding tank. Triplicate egg samples were collected from each of three spawning tanks and analysis of 16S rRNA gene sequences revealed that 88.6% of reads could be identified to 186 taxonomic families. At Day 0, reads corresponding to members of the Vibrionaceae, Colwelliaceae and Rubritaleaceae families were detected at greatest relative abundances. Bacterial communities of eggs varied more greatly between tanks than between samples deriving from the same tank. At Day 5, there was a consistent reduction in 16S rRNA gene sequence richness across the tanks. Even though the eggs from the different tanks were incubated in a common holding tank, the bacterial communities of the eggs from the different tanks had diverged to become increasingly dissimilar. This suggests that the disinfection and incubation exerted differential effects of the microbiota of the eggs from each tank and that the influence of the tank water on the composition of the egg microbiota was lower than expected. This first comprehensive description of the ballan wrasse egg bacterial community is an initial step to understand the role and function of the microbiota on the phenotype of this fish. In future, mass DNA sequencing methods may be applied in hatcheries to screen for pathogens and as a tool to assess the health status of eggs.</p
Human Action Recognition and Localization using Spatio-temporal Descriptors and Tracking
No full textIn this paper we propose a system for human action tracking and recognition using a robust particle filter-based visual tracker and a novel descriptor, to represent spatio-temporal interest points, based on an effective combination of a new 3D gradient descriptor with an optic flow descriptor. These points are used to represent video sequences using a bag of spatio-temporal visual words, following the successful results achieved in object and scene classification. The tracker assigns the points to each individual in a scene, allowing the classification of the action performed by each person. The system has been extensively tested on the standard KTH and Weizmann actions datasets, as well as on real world surveillance videos
Mining livestock genome datasets for an unconventional characterization of animal DNA viromes
No full textWhole genome sequencing (WGS) datasets, usually generated for the investigation of the individual animal genome, can be used for additional mining of the fraction of sequencing reads that remains unmapped to the respective reference genome. A significant proportion of these reads contains viral DNA derived from viruses that infected the sequenced animals. In this study, we mined more than 480 billion sequencing reads derived from 1471 WGS datasets produced from cattle, pigs, chickens and rabbits. We identified 367 different viruses among which 14, 11, 12 and 1 might specifically infect the cattle, pig, chicken and rabbit, respectively. Some of them are ubiquitous, avirulent, highly or potentially damaging for both livestock and humans. Retrieved viral DNA information provided a first unconventional and opportunistic landscape of the livestock viromes that could be useful to understand the distribution of some viruses with potential deleterious impacts on the animal food production systems
A comprehensive overview of mitochondrial DNA insertions in the nuclear genome of the pig
No full textThe integration of nuclear mitochondrial DNA into the mammalian genomes is an ongoing but
rare evolutionary process that produces nuclear sequences of mitochondrial origin (NUMTs).
In this study we identified and analysed NUMTs of the porcine genome. We first constructed a
comparative distribution map of NUMTs in the Sscrofa11.1 reference genome and in other 14
assembled and drafted pig genomes (of Asian and European origin). Then, a total of 581 whole
genome sequencing datasets, from 35 different breeds or populations, were analysed for the
discovery of recently integrated and polymorphic NUMT positions. Overall, we built a comprehensive catalogue of more than 500 NUMTs, some of which were not included in the assemble genomes. Breed-specific NUMTs as well as segregating NUMTs were also identified.
This work lays the base for in-depth studies on the phylogeny of Sus scrofa populations
Tag Suggestion and Localization in User-Generated Videos Based on Social Knowledge
No full textNowadays, almost any web site that provides means for sharing user-generated multimedia content, like Flickr, Facebook, YouTube and Vimeo, has tagging functionalities to let users annotate the material that they want to share. The tags are then used to retrieve the uploaded content, and to ease browsing and exploration of these collections, e.g. using tag clouds. However, while tagging a single image is straightforward, and sites like Flickr and Facebook allow also to tag easily portions of the uploaded photos, tagging a video sequence is more cumbersome, so that users just tend to tag the overall content of a video. Moreover, the tagging process is completely manual, and often users tend to spend as few time as possible to annotate the material, resulting in a sparse annotation of the visual content. A semi-automatic process, that helps the users to tag a video sequence would improve the quality of annotations and thus the overall user experience. While research on image tagging has received a considerable attention in the latest years, there are still very few works that address the problem of automatically assigning tags to videos, locating them temporally within the video sequence. In this paper we present a system for video tag suggestion and temporal localization based on collective knowledge and visual similarity of frames. The algorithm suggests new tags that can be associated to a given keyframe exploiting the tags associated to videos and images uploaded to social sites like YouTube and Flickr and visual features
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