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- ItemIntestinal flow rates, absorption of felodipine from the small intestine and attributes of chyme collected at midgut from Labradors(Tübingen : Universitätsbibliothek Tübingen, 2023) Diebold, Steffen M.The objectives of the present study were (1) to investigate gastrointestinal hydrodynamics of Labradors as a model for human midgut (2) to examine various attributes of intestinal fluids in vivo and (3) to study the influence of hydrodynamics on the dissolution and absorption of a poorly soluble drug from various suspensions. Gastrointestinal flow rates were determined volumetrically using an aspiration method. Isotonic saline and 20 % glucose solutions were used to alter gastrointestinal hydrodynamics. Felodipine, a BCS class II substance, was suspended in these fluids. Osmolality, pH, bile acid concentration and drug solubility in various chyme samples were determined. Blood plasma levels of felodipine were recorded while gastrointestinal dissolution was ongoing. Fluid recovery at midgut fistula was significantly higher (>100 %) for glucose 20 % than for isotonic saline solutions (70 %). After administration of 200 ml glucose 20 % the (overall) grand median of differential gastrointestinal flow rates (DFR) was 8.3 ml/min.. Individual spike flow ranged from 20 up to 60 ml/min. Corresponding flow rates after administration of 200 ml isotonic saline were 35.0 ml/min. for the grand median including individual spike flows beyond 100 ml/min.. Within and between-dog variability in flow rate data was similar. In general, glucose solutions released more evenly. Following oral administration of glucose solution 20 % osmolality of intestinal fluids decreased within 40 min. from about 1000 mOsm. towards more physiological values of about 350 mOsm.. Saturation solubility of felodipine (Cs) in jejunal chyme after administration of either solution (saline or glucose) was determined to be about 10 (µg/ml) on average (median), exposing high variability with time! The intestinal solubility varied greatly within the course of an experiment. However, a strong correlation was observed between the aspirated fluid volume and the dissolved amount of felodipine confirming the well known relationship of Noyes, Whitney, Nernst and Brunner in-vivo. Grand median of pH in jejunal chyme of labradors was determined to be 6.68. Median values range from 4.38-7.62. The pharmacokinetic data showed a slight trend to differences based on particle size and on fluid administered.
- ItemSocial media reveals consistently disproportionate tourism pressure on a threatened marine vertebrate(Oxford [u.a.] : Wiley-Blackwell, 2020) Papafitsoros, K.; Panagopoulou, A.; Schofield, G.Establishing how wildlife viewing pressure is distributed across individual animals within a population can inform the management of this activity, and ensure targeted individuals or groups are sufficiently protected. Here, we used social media data to quantify whether tourism pressure varies in a loggerhead sea turtle Caretta caretta population and elucidate the potential implications. Laganas Bay (Zakynthos, Greece) supports both breeding (migratory, and hence transient) and foraging (resident) turtles, with turtle viewing representing a major component of the tourism industry. Social media entries spanning two seasons (April to November, 2018 and 2019) were evaluated, and turtles were identified via photo-identification. For the 2 years, 1684 and 2105 entries of 139 and 122 unique turtles were obtained from viewings, respectively (boats and underwater combined). However, while residents represented less than one-third of uniquely identified turtles, they represented 81.9 and 87.9% of all entries. Even when the seasonal breeding population was present (May to July), residents represented more than 60% of entries. Notably, the same small number of residents (<10), mostly males, were consistently viewed in both years; however, different individuals were targeted by boats versus underwater. Thus, turtles appear to remain in the area despite high viewing intensity, possibly indicating low disturbance. However, photo-identification records revealed a high risk of propeller and boat strike to residents (30%) leading to trauma and mortality. To reduce this threat, we recommend the compulsory use of propeller guards for all boats, compliance with speed regulations and the creation of temporary ‘refuge’ zones for resident animals at viewing hotspots, with these suggestions likely being relevant for other wildlife with similar population dynamics. In conclusion, social media represents a useful tool for monitoring individuals at a population scale, evaluating the pressure under which they are placed, and providing sufficient data to refine wildlife viewing guidelines and/or zoning. © 2020 The Authors. Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of London
- ItemDynamic cooling strategy based on individual animal response mitigated heat stress in dairy cows(Amsterdam : Elsevier, 2020) Levit, H.; Pinto, S.; Amon, T.; Gershon, E.; Kleinjan-Elazary, A.; Bloch, V.; Ben Meir, Y.A.; Portnik, Y.; Jacoby, S.; Arnin, A.; Miron, J.; Halachmi, I.Technological progress enables individual cow's temperatures to be measured in real time, using a bolus sensor inserted into the rumen (reticulorumen). However, current cooling systems often work at a constant schedule based on the ambient temperature and not on monitoring the animal itself. This study hypothesized that tailoring the cooling management to the cow's thermal reaction can mitigate heat stress. We propose a dynamic cooling system based on in vivo temperature sensors (boluses). Thus, cooling can be activated as needed and is thus most efficacious. A total of 30 lactating cows were randomly assigned to one of two groups; the groups received two different evaporative cooling regimes. A control group received cooling sessions on a preset time-based schedule, the method commonly used in farms; and an experimental group, which received the sensor-based (SB) cooling regime. Sensor-based was changed weekly according to the cow's reaction, as reflected in the changes in body temperatures from the previous week, as measured by reticulorumen boluses. The two treatment groups of cows had similar milk yields (44.7 kg/d), but those in the experimental group had higher milk fat (3.65 vs 3.43%), higher milk protein (3.23 vs 3.13%), higher energy corrected milk (ECM, 42.84 vs 41.48 kg/d), higher fat corrected milk 4%; (42.76 vs 41.34 kg/d), and shorter heat stress duration (5.03 vs 9.46 h/day) comparing to the control. Dry matter intake was higher in the experimental group. Daily visits to the feed trough were less frequent, with each visit lasting longer. The sensor-based cooling regime may be an effective tool to detect and ease heat stress in high-producing dairy cows during transitional seasons when heat load can become severe in arid and semi-arid zones.
- ItemOpinion paper : Measuring livestock robustness and resilience : are we on the right track?(Amsterdam : Elsevier, 2019) Llonch, P.; Hoffmann, G.; Bodas, R.; Mirbach, D.; Verwer, C.; Haskell, M.J.[No abstract available]