A 24 Hour Ecotoxicity Test for Acid Mine Drainage Using Hatching Success in Daphnia magna

A bioassay utilizing the cladoceran Daphnia magna hatching success is presented for testing the toxicity of acid mine drainage (AMD) sediments. AMD sediments contain complex mixtures of potential toxins and a rapid, sensitive bioassay is valuable for assessing toxicity in the field, particularly after transient environmental events. Daphnia magna was incubated in water exposed to 1. clean sand spiked with different proportions of a mixture of metal salts and 2. sand mixed with different proportions of AMD sediments. Hatching success was linearly related to both the proportion of artificially spiked sediments (r= -0.83; p= 0.0002) and the proportion of AMD sediments (r = -0.74; p= 0.02) that Daphnia magna was exposed to during incubations. No animals hatched during the first 18 hrs of observation under any treatments, so a single observation at 24 h is practical for this assay. The assay should be generally applicable to toxicity testing, particularly when assessing complex mixtures of pollutants in field settings. The novelty of the proposed study lies in the fact that it proposes the fastest ecotoxicity assay that we know of using Dahpnia magna. Potentially, after appropriate calibration for the particular pollutant of interest, it could be used to test for a wide array of aquatic pollutants

Regenerative peripheral nerve interfaces for real-time, proportional control of a Neuroprosthetic hand

Abstract Introduction Regenerative peripheral nerve interfaces (RPNIs) are biological constructs which amplify neural signals and have shown long-term stability in rat models. Real-time control of a neuroprosthesis in rat models has not yet been demonstrated. The purpose of this study was to: a) design and validate a system for translating electromyography (EMG) signals from an RPNI in a rat model into real-time control of a neuroprosthetic hand, and; b) use the system to demonstrate RPNI proportional neuroprosthesis control. Methods Animals were randomly assigned to three experimental groups: (1) Control; (2) Denervated, and; (3) RPNI. In the RPNI group, the extensor digitorum longus (EDL) muscle was dissected free, denervated, transferred to the lateral thigh and neurotized with the residual end of the transected common peroneal nerve. Rats received tactile stimuli to the hind-limb via monofilaments, and electrodes were used to record EMG. Signals were filtered, rectified and integrated using a moving sample window. Processed EMG signals (iEMG) from RPNIs were validated against Control and Denervated group outputs. Results Voluntary reflexive rat movements produced signaling that activated the prosthesis in both the Control and RPNI groups, but produced no activation in the Denervated group. Signal-to-Noise ratio between hind-limb movement and resting iEMG was 3.55 for Controls and 3.81 for RPNIs. Both Control and RPNI groups exhibited a logarithmic iEMG increase with increased monofilament pressure, allowing graded prosthetic hand speed control (R2 = 0.758 and R2 = 0.802, respectively). Conclusion EMG signals were successfully acquired from RPNIs and translated into real-time neuroprosthetic control. Signal contamination from muscles adjacent to the RPNI was minimal. RPNI constructs provided reliable proportional prosthetic hand control.https://deepblue.lib.umich.edu/bitstream/2027.42/146521/1/12984_2018_Article_452.pd

Determination of the efficacy and side-effect profile of lower doses of intrathecal morphine in patients undergoing total knee arthroplasty

<p>Abstract</p> <p>Background</p> <p>Intrathecal (IT) morphine provides excellent post-operative analgesia, but causes multiple side effects including nausea and vomiting (PONV), pruritus and respiratory depression, particularly at higher doses. The lowest effective dose of spinal morphine in patients undergoing total knee arthroplasty is not known.</p> <p>Methods</p> <p>We evaluated the analgesic efficacy and side effect profile of 100 – 300 μg IT morphine in patients undergoing elective total knee replacement in this prospective, randomized, controlled, double-blind study. Sixty patients over the age of 60 undergoing elective knee arthroplasty were enrolled. Patients were randomized to receive spinal anaesthesia with 15 mg Bupivacaine and IT morphine in three groups: (i) 100 μg; (ii) 200 μg; and (iii) 300 μg.</p> <p>Results</p> <p>Both 200 μg and 300 μg IT morphine provided comparable levels of postoperative analgesia. However, patients that received 100 μg had greater pain postoperatively, with higher pain scores and a greater requirement for supplemental morphine. There were no differences between groups with regard to PONV, pruritus, sedation, respiratory depression or urinary retention.</p> <p>Conclusion</p> <p>Both 200 μg and 300 μg provided comparable postoperative analgesia, which was superior to that provided by 100 μg IT morphine in patients undergoing total knee arthroplasty. Based on these findings, we recommend that 200 μg IT morphine be used in these patients.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Identifier NCT00695045</p

Effect of phytosterol supplementation on Acartia egg production (PhytosterolsZooplank project)

Dataset: Sterols and Acartia egg productionThis dataset includes viable egg production of the copepod Acartia tonsa that were fed a diet supplemented with a variety of phytosterols at two food concentrations. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/724158NSF Division of Ocean Sciences (NSF OCE) OCE-1061973, NSF Division of Ocean Sciences (NSF OCE) OCE-106195

Effect of phytosterol supplementation on Artemia growth (PhytosterolsZooplank project)

Dataset: Sterols and Artemia growthThis dataset includes growth rates measured as biomass change of the brine shrimp Artemia that were fed a diet supplemented with a variety of phytosterols. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/724179NSF Division of Ocean Sciences (NSF OCE) OCE-1061973, NSF Division of Ocean Sciences (NSF OCE) OCE-106195

Habitat temperature is an important determinant of cholesterol contents in copepods

Effects of habitat and acclimation temperature on cholesterol contents were examined in oceanic and inshore species of copepods. The cholesterol content of five species of thermally acclimated copepods was determined, and nine species (representing six families) were sampled to assess the role of habitat temperature. The species selected have maximum habitat temperatures (and temperature tolerances) that vary at least twofold. Levels of dietary cholesterol required to achieve maximum growth were also studied at different acclimation temperatures in a eurythermal copepod. Both eggs and copepodites of Calanus finmarchicus had higher cholesterol levels at the warm acclimation temperature (16°C) than at the cooler temperature (6°C). Neither Acartia tonsa, Acartia hudsonica, Temora longicornis nor Eurytemora affinis altered cholesterol contents with acclimation temperature. Maximum growth rates were achieved at fourfold higher concentrations of dietary cholesterol in warm-acclimated Eurytemora affinis than in cold-acclimated animals. The most consistent trend is the positive relationship between cholesterol content and habitat temperature. Species residing in warmer habitats (e.g. Centropages typicus, Eurytemora affinis) had approximately twice the cholesterol of species living in colder waters (e.g. Calanus glacialis, Euchaeta norvegica). A similar pattern was observed for comparisons of species within genera (Calanus, Acartia and Centropages), with the species abundant at lower latitudes having more cholesterol than the northern congener. These data indicate that habitat temperature is an important determinant of cholesterol content, and cholesterol endows membranes with the stability required for a range of body temperatures

National Oceanic and Atmospheric Administration Report 215

From introduction: This data report is intended to provide a detailed data summary of station information and copepod abundances that will be used for future publication of the analyzed data set. A data report on larval fish distributions from the same seasonal cruises will also be issued, and the distribution of tuna larvae has been discussed

A 24 Hour Ecotoxicity Test for Acid Mine Drainage Using Hatching Success in Daphnia magna

A bioassay utilizing the cladoceran Daphnia magna hatching success is presented for testing the toxicity of acid mine drainage (AMD) sediments. AMD sediments contain complex mixtures of potential toxins and a rapid, sensitive bioassay is valuable for assessing toxicity in the field, particularly after transient environmental events. Daphnia magna was incubated in water exposed to 1. clean sand spiked with different proportions of a mixture of metal salts and 2. sand mixed with different proportions of AMD sediments. Hatching success was linearly related to both the proportion of artificially spiked sediments (r= -0.83; p= 0.0002) and the proportion of AMD sediments (r = -0.74; p= 0.02) that Daphnia magna was exposed to during incubations. No animals hatched during the first 18 hrs of observation under any treatments, so a single observation at 24 h is practical for this assay. The assay should be generally applicable to toxicity testing, particularly when assessing complex mixtures of pollutants in field settings. The novelty of the proposed study lies in the fact that it proposes the fastest ecotoxicity assay that we know of using Dahpnia magna. Potentially, after appropriate calibration for the particular pollutant of interest, it could be used to test for a wide array of aquatic pollutants