Cryptic diversity in the leptothecate genera Laodicea and Tiaropsis (Cnidaria: Hydrozoa)

Postponed access: the file will be accessible after 2022-09-01Although they are an ecologically and economically important group of animals, hydrozoans are understudied because of their difficult identification due to their small size and fragility. Hydrozoans as a group show a great diversity in life strategies, and often include both a polyp and a medusa stage in their life cycle, which complicates their taxonomy because both stages may be needed for a correct identification. For the two leptothecate hydrozoan genera Laodicea (Family Laodiceidae) and Tiaropsis (Family Tiaropsidae), the polyp stage is very small and easy to overlook, while the medusa stage is conspicuous and relatively straightforward to identify, at least to genus level. Only one species of each of these genera is believed to occur in Norwegian waters, Laodicea undulata (Forbes &Goodsir, 1853) and Tiaropsis multicirrata (M. Sars, 1835), but preliminary data suggest that the diversity of these taxa in the region is higher than previously thought. In this study, I used DNA barcoding and different molecular species delimitation methods (based on mitochondrial markers 16S and COI and the nuclear marker ITS) in combination with a detailed morphological analysis of both the hydroid and medusa stages to assess the species diversity of the genera Laodicea and Tiaropsis in Norway. Based on molecular evidence, Laodicea undulatais shown to comprise two molecularly distinct Norwegian clades, which appear not to be sister species. Specimens morphologically identified as T. multicirrata split up into three distinct clades in Norway according to the evaluated molecular markers, indicating cryptic diversity in Tiaropsis for the studied region. For both Tiaropsis and Laodicea, the results suggest that the observed clades correspond to undescribed species, but further work is necessary to place them in a broader phylogenetic perspective and to identify any potential morphological characters that define them.Master's Thesis in BiologyBIO399MAMN-BIOMAMN-HAVS

Red Cell Distribution Width: an Unacknowledged Predictor of Mortality and Length of Stay following Revision Arthroplasty

Introduction Red blood cell distribution width (RDW), a measure of variability in size of circulating erythrocytes, is routinely reported in complete blood cell analysis, and together with mean cell volume (MCV) has conventionally been used to distinguish the cause of anemia. It is calculated by (Standard deviation of MCV÷ mean MCV) x 100, with normal range being 11.5%-14.5%. Several recent publications have described RDW as an independent predictor of adverse outcome and mortality in patients with different underlying medical conditions such as acute and chronic heart failure, peripheral artery disease, chronic pulmonary disease and acute kidney injury1. The purposes of this study were 1) to investigate possible relationship between RDW levels and length of stay (LOS) and mortality following revision total joint arthroplasty (TJA), and if that correlation existed, 2) to develop predictive models for LOS and mortality based on preoperative patient-related factors including RDW values

Operating Room Traffic Increases Aerosolized Particles and Compromises the Air Quality: A Simulated Study.

BACKGROUND: Strategies to prevent bacterial fallout and reduce particle count in the operating room (OR) are key components of preventing periprosthetic joint infection. Although OR traffic control is an important factor, a quantitative study has not been performed to investigate the influence of personnel and door opening on OR air quality. This simulated study aimed to examine the influence of these 2 factors on particle density in OR with and without the laminar air flow (LAF). METHODS: Both experiments took place within an empty OR of an arthroplasty unit equipped with an LAF system. First, the number of particles in the air was counted using a particle counting apparatus while 9 persons entered the room, one every 15 minutes. Second, the door was opened and closed starting with zero door openings per minute and increasing to 4 in 15-minute increments. Both experiments were performed once with the LAF turned on and once without. RESULTS: The number of personnel in the OR and the number of door openings per minute correlate with the density of particles. Both relationships were significantly reduced by turning the LAF on (correlation coefficients CONCLUSION: This study confirms that personnel and door opening are a major source of particles in the OR air. Controlling traffic is critical for reduction of particles and is likely to be a key preventative strategy in reducing periprosthetic joint infection. LAF is protective against the negative influence of number of people and door openings