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Nest building and burrowing are highly motivated natural behaviors in rodents, and changes in these behaviors can serve as welfare assessment tools. In this study, we investigated: 1) the limits of agreement between 2 observers for a refined scoring method for nest-building behavior; 2) the effect of repeated exposure to 15 min of isoflurane on nest-building behavior; 3) the effect of 24 h of grid-floor housing, repeated exposure to 15 min isoflurane, and daily intraperitoneal injection of 0.2 mL 0.9% isotonic saline for 3 d on burrowing behavior; and 4) the effect of exposure to grid-floor housing, isoflurane, and intraperitoneal injections on fecal corticosterone metabolites, body weight, fur status, and sucrose preference in mice. SPF C57BL/6NTac female mice (n = 27) were included in the study and were assessed first for burrowing behavior, followed by 2 wk of rest and then for nesting behavior. The refined scoring method for nest-building activity had good inter observer agreement. According to this method, a single exposure to anesthesia with isoflurane led to a decrease in nest-building activity and sucrose preference; a second exposure to anesthesia with isoflurane had no effect on nest building. Neither grid-floor housing nor repeated exposure to isoflurane anesthesia had any effect on burrowing behavior in mice. In contrast, intraperitoneal injections increased burrowing behavior. In conclusion, a refined scoring method for nest-building activity test that we developed for this study proved to be objective and sensitive to the effect of an initial exposure to anesthesia with isoflurane.

When introducing environmental enrichment in laboratory animals, positive and/or negative effects on behavioural and physiological parameters should be evaluated. This three-step randomised controlled trial in male C57BL/6 mice investigated the effect of supplementing the environment with one or more hemp ropes. In part 1, the effect of a hemp rope on aggressive and social behaviour, stress and anxiety levels was assessed by social interaction test, elevated plus maze behaviour, and faecal corticosterone metabolites, respectively (n = 224 mice). In part 2, the effect of 1, 2 or 7 hemp ropes on aggressive behaviour in mice subjected to routine handling was evaluated by assessing the number of wounded companion animals and wounds per animal (n = 224). In part 3, climbing activity in the rope and amount of material shredded from the rope was assessed (n = 56). Mice housed with one hemp rope engaged in social behaviour for longer time than mice housed without a hemp rope, while no difference was detected in stress and anxiety levels. No difference was seen in the number of wounded animals or wounds per animal when adding 1, 2 or 7 hemp ropes to the existing environment in mice undergoing minimal human handling. The mice continuously shredded and climbed the rope, even when provided with a new rope, although time spent climbing decreased slightly over time. Thus, a hemp rope can be used as additional environmental enrichment amongst male C57BL/6 mice.

Objectives To study chronic headache and medication-overuse headache (MOH) prevalence; to identify groups with high prevalence of these conditions; and to identify the most frequently used pain medications among respondents with chronic headache. Background Chronic headache and MOH prevalence in Denmark were last estimated in 2010. Methods In this cross-sectional study, 104,950 individuals aged ≥16 years were randomly sampled for the 2017 Danish Capital Region Health Survey. Responses to questions about headache and use of acute pain medications were linked to demographic registries. MOH was defined as headache ≥15 days/month plus self-report of use of pain medications ≥10 or 15 days/month, in the last three months. Weighted prevalence proportions were calculated. Results Among 55,185 respondents, chronic headache prevalence was 3.0% (95% CI: 2.3–3.2) and MOH prevalence was 2.0% (95% CI: 1.8–2.1). Both conditions were more common among females and the middle-aged. Respondents on social welfare or receiving early retirement pensions had the highest prevalences. Among those with chronic headache, 44.7% overused over-the-counter analgesics for headache; paracetamol 41.5%; a combination of different pain relievers 25.3%; ibuprofen 21.9%; opioids 17.0%; combination preparations 14.3%; and triptans 9.1%. Conclusions The highest prevalence of chronic headache and MOH was seen among people with low socioeconomic position. Overuse of paracetamol was most common. Reported opioid use was higher than expected. Groups with high prevalence of MOH should be the focus of public health interventions on rational use of OTC and prescription pain medications.

Introduction Repeated blood sampling is a common procedure in laboratory mice, but at present it is unknown which technique has the least impact on the animals when large or repeated blood samples are required. Retro-bulbar sinus puncture is a reliable technique but has been shown to cause many changes in the animals, why sublingual and facial vein puncture have been suggested as suitable alternatives. This study investigated 1) which of the three blood sampling techniques had the least impact on nest building activity, level of faecal corticosterone metabolites, body weight, fur status, and macroscopic changes, 2) whether the blood sampling techniques gave rise to variation in blood quality between blood samples, and 3) whether sublingual and facial vein puncture should be performed with or without anaesthesia in female C57BL/6 mice. Method Three hundred and sixty C57BL/6 female mice divided into five batches were included in the study and randomized to a short (blood sampling on Day 8, 9 and 10) or a long protocol (blood sampling on Day 8, 15 and 22). Each protocol consisted of six identical groups: sublingual vein puncture (SVP), sublingual vein puncture in isoflurane (SVPiso), facial vein puncture (FVP), facial vein puncture in isoflurane (FVPiso), retro-bulbar sinus puncture (RBP), and a control group (CONTROL) with only scruffing being performed. At baseline (Day 2) nest building activity (NBA) was assessed and faecal pellets collected for evaluation of faecal corticosterone metabolites (FCM). The day after each blood sampling day NBA and FCM were reassessed. Results and conclusion None of the blood sampling techniques proved to be superior to the others in any of the measured parameters. Finally, sublingual and facial vein puncture performed under anaesthesia gave rise to variation in the quality of the blood. A refinement of all three techniques are therefore warranted.

It is argued that mice have poor colour vision and are insensitive to the colour red, which they in theory perceive as dark. Therefore, the red tinted Bio-Serv Mouse Igloo® is used to provide mice with a dark shelter while enabling humans to monitor the animals through the shelter without disturbing them. However, we do not know if mice like the colour red. Therefore, this study investigated whether mice prefer an amber or blue igloo over a red igloo, still making it possible for humans to see through the igloos. A preference test consisting of 3 cages each containing a different coloured igloo, connected to a barren central cage, was conducted for 11 h 20 min in 32 female B6 mice. The results showed that some female B6 mice did not like to use the Bio-Serv Mouse Igloo® as a shelter, regardless of colour. Almost half of the mice chose to stay outside the igloos, but when choosing an igloo the mice preferred the blue or amber igloo over the red igloo., Scandinavian Journal of Laboratory Animal Sciences, Vol. 44 (2018)

Burrowing and nest building are examples of highly motivated innate behaviours in rodents. Assessments based on these behaviours can be used as non-invasive indicators of pain, distress and suffering. In this study, we investigated the effect of three stressful procedures, namely grid floor housing for 24 h, 15 min of isoflurane anaesthesia and an intraperitoneal saline injection daily for three days, on nest building and burrowing in female C57BL/6NTac mice. For burrowing, we also investigated the effect of the presence of a shelter and nesting material (standard home cage enrichment) versus no shelter and nesting material, and whether the test can be performed during normal working hours. Alongside this, we investigated the effect of grid floor, isoflurane anaesthesia and intraperitoneal injections on stress hormone level, body weight, fur status and sucrose preference. The burrowing test was found to be sensitive to 24 h grid floor housing when no shelter but only a cardboard tube was present during testing. The mice burrowed a mean of 21 g less after grid floor housing (P .01). This change was accompanied by decreased sucrose preference (P .01) and body weight (P .01). 15 min of anaesthesia with isoflurane induced changes in the nest building activity test. After exposure to isoflurane the mice built less complex nests (P = .04). This was accompanied by a decrease in sucrose preference (P .01), a decrease in body weight (P .01), and elevated stress hormone levels (P .01). One daily intraperitoneal injection of saline for three days did not result in changes in nest building activity (P .01). We also found that the mice burrowed equal amount during normal working hours and prior to the dark phase, indicating that the burrowing test can be performed during normal working hours instead of prior to the dark phase (P = .62).

Infrared thermography has been suggested as a non-invasive, objective tool to evaluate animal welfare. In this study, we investigated: 1) how body temperature, measured through thermal imaging, is affected by different mild stressors frequently experienced by laboratory mice; 2) which methodology to use for assessing temperature variations with infrared thermography; 3) whether the chosen stressors cause anxiety in mice. Eighty C57BL/6 male mice were included in the study. The mice were allocated to either a control group or one of three groups being subjected to a mild stressor once daily for 4 days: 1) anaesthesia with isoflurane for 10 min; 2) handling by scruffing; 3) intraperitoneal injection of 0.2 ml 0.9% saline. On all four intervention days, thermal images were obtained in all groups and all animals were assessed for fur status and body weight. On day five, all animals were tested in the elevated-plus-maze for 5 min. From the thermal images, the maximum eye temperature, the maximum tail base temperature and the average body temperature were obtained. Ten minutes of anaesthesia with isoflurane led to a decrease in maximum eye temperature, average body temperature and maximum tail base temperature. The animals recovered from this drop in temperature within 10 min. No drop in temperature was seen after scruffing or intraperitoneal injection of saline. Based on the number of missing values, intra-rater and inter-rater agreement, the average body temperature was found most ideal for measuring body temperature variations in mice. Finally, the elevated plus maze did not reveal any differences in anxiety between the groups and the body weight did not decrease at any time point during the study.

This paper presents the development of a predictive model for topside annulus vent gas flow from a flexible riser and the infrastructure to feed live operational data from the offshore process, subsea and vent systems to a cloud solution. The presented data is accessed and processed through analytics prior to live presentation on a digital platform accessible to offshore and onshore subsea engineers, and to anyone inside or outside the operator's organization in need for the data and operational status. The aim is to use all available sensor data related to five operative high temperature flexible risers to reveal emerging evolvement of a failure mode previously experienced on similar risers in similar service. Carcass collapse in the seabed segment of the flexible riser is identified as the key failure mode in need for mitigation actions. The collapse is caused by excessive pressure in pipe designs with multi-layer pressure sheath, and has been observed on several occasions during startup after longer maintenance and shut down periods. As the flow rate in the risers is moderate and the performance of wells varies, it is not possible to identify the carcass collapse by pressure drop monitoring, not even with detailed analysis of pressure differences topside and subsea. Concatenating all pressure, temperature, annulus volume testing, inspection and annulus monitoring data in real time established the basis for applying machine learning techniques to identify when a carcass failure emerged. Combining data analytics with in depth understanding of the flexible pipe cross section, failure mode development and pipe dissection experiences enabled an analytics solution providing early warning of an emerging damage. As all the utilized measurement data was available, also for two previous carcass damages in identical risers, validation and confidence of the models could be established to identify these damages early. On this basis, it was concluded that the focused monitoring and digital analytics gave sufficient risk mitigation for the five remaining operating risers of the same type.

With basis in field experiences from several carcass axial failures in HT/HP unbonded flexible risers a comprehensive program was initiated to determine the root cause and develop a theoretical framework for prediction of the loads and mechanisms leading to damage initiation and development. The physical understanding, theory, tools and methods were developed in a close cooperation between the field operator Statoil, 4Subsea and DNV GL. Following the discovery of carcass tearing as a new failure mode in May 2011 substantial work has been put into small- and mid-scale testing together with the establishment of various analysis models to describe the carcass tearing phenomenon. This development and test work has been presented at OMAE-2013/14. Since 2011 substantial work has been put into small- and mid-scale testing together with various analysis models to describe the carcass pull-out phenomenon. As a final full-scale validation, an onshore fully instrumented test was conducted to assess the accuracy of the carcass tearing models and evaluate variability and uncertainties related to use of the developed tools and methods for risk assessment of similar HT/HP pipes still in operation. The flexible riser used for the test was a full length 830m long pipe recovered after 15 years’ successful operation at a North Sea Field. The pipe integrity was not jeopardized and the pipe was fully functional at the time of recovery. The pipe was recovered due to unfavorable risk assessment and plans for full-scale testing. The full-scale test gathers as many aspects as possible into a single test to verify the analytical solutions proposed during this work. The test pipe was used with the original end-fittings with the full pipe length intact. The end sections of length were unreeled, secured, protected and supported. As preparation to the test, finite element analyses of the flexible riser were performed to predict the carcass axial load in the end-fitting. The analysis also served as valuable input to the test procedure and instrumentation plan. Along with analyses, a set of novel measurement and instrument solutions were developed. This includes, live video monitoring of carcass movements and strain measurements at carcass, with temperature and pressure well outside standard solutions. Bore temperature and pressure varied from 0–90 °C and 0–500 barg, respectively. Several temperature and pressure cycles were done. Comparison between detailed finite element analysis and full-scale results shows excellent correlation. The riser and end-fittings have been dissected after testing. Key findings from dissection match the predicted behavior well.

This paper discusses the structural challenges associated with high axial temperature gradients and the corresponding internal cross section forces. A representative flexible pipe section designed for high operational temperature has been subject to full scale testing with temperature profiles obtained by external heating and cooling. The test is providing detailed insight in onset and magnitude of relative layer movements and layer forces. As part of the full-scale testing, novel methods for temperature gradient testing of unbonded flexible pipes have been developed, along with layer force- and deflection-measurement techniques. The full-scale test set-up has been subject to numerous temperature cycles of various magnitudes, gradients, absolute temperatures, as well as tension cycling to investigate possible couplings to dynamics. Extensive use of finite element analysis has efficiently supported test planning, instrumentation and execution, as well as enabling increased understanding of the structural interaction within the unbonded flexible pipe cross section. When exploiting the problem by finite element analysis, key inputs will be correct material models for the polymeric layers, and as-built dimensions/thicknesses. Finding the balance between reasonable simplification and model complexity is also a challenge, where access to high quality full-scale tests and dissected pipes coming back from operation provides good support for these decisions. Considering the extensive full scale testing, supported by advanced finite element analysis, it is evident that increased attention will be needed to document reliable operation in the most demanding high temperature flexible pipe applications.