Developments in benthos and fish in gullies in an area closed for human use in the Wadden Sea : 2002-2016

In the eastern Dutch Wadden Sea an area was closed for anthropogenic bottom-disturbing activities in 2005. The ‘natural’ development of the fauna in gullies located within this area was monitored and compared with the development in gullies outside the closed area. Emphasis was put on sampling the benthic fauna (every autumn). Eleven years after closure (2016) the fish population was sampled again and additional benthic samples were taken, the sea floor was mapped and the fishing pressures were calculated. Preliminary results show that throughout the investigated period the open gullies were subject to moderate shrimp fishing pressures and that the closed gullies were not fished. Closure of the gullies has not yet led to the formation of biogenic structures on the seafloor, but has led to an increase in the species richness of small benthic fauna and to subtle changes in benthic species composition. Due to the limited availability of data it was not possible to detect statistically significant differences in the fish population. Sinds november 2005 is een klein deel van de Nederlandse Waddenzee gesloten voor (potentieel) schadelijke menselijke activiteiten. Het gebied ligt ten zuiden van Rottumerplaat en Rottumeroog en beslaat zo’n 7400 hectare. Doel van de sluiting is om de ongestoorde ontwikkeling van de natuur in de Waddenzee te kunnen volgen. Dit rapport beschrijft de tussentijdse resultaten, 11 jaar naar sluiting. In het monitorprogramma is de nadruk gelegd op veranderingen in de bodemfauna die jaarlijks en vanaf 2002 in het najaar bemonsterd worden. In 2016 zijn aanvullende bemonsteringen uitgevoerd. In dat jaar is de visgemeenschap herbemonsterd, zijn additionele bodemmonsters genomen gericht op het bemonsteren van de wat grotere organismen, zijn de karakteristieken van het bodemoppervlak in kaart gebracht en is de visserijdruk in het gebied berekend. Voorlopige resultaten laten zien dat in de open geulen garnalenvisserij heeft plaatsgevonden gedurende de hier bestudeerde periode en dat in de gesloten geulen geen visserij heeft plaatsgevonden na 2005. Sluiting van de geulen heeft nog niet geleid tot vestiging van biogene structuren. Wel is de soortenrijkdom toegenomen en hebben er zich subtiele veranderingen in bodemdiersamenstelling voorgedaan. Vanwege de beperkte hoeveelheid gegevens was het niet mogelijk om uitspraken te doen over veranderingen in de vispopulatie

In vivo pharmacokinetics of a gentamicin-loaded collagen sponge in acute periprosthetic infection - Serum values in 19 patients

Background The in vivo pharmacokinetics of gentamycin- loaded collagen fleeces in humans have not been described in the current literature. We therefore analyzed in vivo pharmacokinetics of these fleeces when used in the treatment of periprosthetic infections. Patients and methods Gentamycin concentrations were measured in 19 consecutive patients with an acute periprosthetic infection. Each patient received 2-5 fleeces (130 mg gentamycin/fleece). Results Initially, the blood concentration increased to 3.2-7.2 mg/L, depending on the number of fleeces that were applied. The serum peak concentrations resulted in peak/MIC ratios of 2.5-36 for P. aeruginosa, S. aureus, and Klebsiella spp. Subsequently, the serum values decreased almost linearly below 0.3 mg/L in 18 to 62 hours. After 24 hours, the serum levels of gentamicin dropped below 2 mg/L, the toxicity threshold. Interpretation The application of 2 to 5 130-mg gentamycin-loaded collagen fleeces may be useful as an adjuvant treatment for implant-related infections, since no toxic concentrations were measured 24 hours postoperatively

First geolocator tracks of Swedish red-necked phalaropes reveal the Scandinavia-Arabian Sea connection

We studied migration and wintering patterns of a wader with a pelagic lifestyle during the non-breeding period, the rednecked phalarope Phalaropus lobatus . Using light-level geolocation, we obtained three full annual tracks and one autumn migration track of male red-necked phalaropes caught during breeding in Scandinavia. Th ese tracks confi rmed expectations that individuals from the Scandinavian population winter in the Arabian Sea. Migration was accomplished in two to four migration leaps, staging for a few days in the Gulf of Finland (autumn) or the southern Baltic Sea (spring) and for up to a month in or near the Black and Caspian Sea (autumn and spring). In addition, travel speeds suggested that only the fl ights between the Baltic and Black/Caspian Sea are non-stop, and thus the birds seem to make additional short stops during the other flights. Stopover time in the Black/Caspian Sea is only 8 – 10 d in spring but up to 36 d in autumn, which is longer than expected if only used for pre-migratory fattening to cover the ca 2000 km to the Gulf of Oman. After entering the Arabian Sea via the Gulf of Oman, birds dispersed over the entire presumed winter range. Winter movements appear to correspond to the spatio-temporal patterns in primary production linked to seasonally changing monsoon winds. Th ese are not only the first tracks of Scandinavian red-necked phalaropes, but also the fi rst seabird tracks in the Arabian Sea, one of the most productive and dynamic marine areas on the planet

Eggs in the Freezer: Energetic Consequences of Nest Site and Nest Design in Arctic Breeding Shorebirds

Birds construct nests for several reasons. For species that breed in the Arctic, the insulative properties of nests are very important. Incubation is costly there and due to an increasing surface to volume ratio, more so in smaller species. Small species are therefore more likely to place their nests in thermally favourable microhabitats and/or to invest more in nest insulation than large species. To test this hypothesis, we examined characteristics of nests of six Arctic breeding shorebird species. All species chose thermally favourable nesting sites in a higher proportion than expected on the basis of habitat availability. Site choice did not differ between species. Depth to frozen ground, measured near the nests, decreased in the course of the season at similar non-species-specific speeds, but this depth increased with species size. Nest cup depth and nest scrape depth (nest cup without the lining) were unrelated to body mass (we applied an exponent of 0.73, to account for metabolic activity of the differently sized species). Cup depth divided by diameter2 was used as a measure of nest cup shape. Small species had narrow and deep nests, while large species had wide shallow nests. The thickness of nest lining varied between 0.1 cm and 7.6 cm, and decreased significantly with body mass. We reconstruct the combined effect of different nest properties on the egg cooling coefficient using previously published quantitative relationships. The predicted effect of nest cup depth and lining depth on heat loss to the frozen ground did not correlate with body mass, but the sheltering effect of nest cup diameter against wind and the effects of lining material on the cooling coefficient increased with body mass. Our results suggest that small arctic shorebirds invest more in the insulation of their nests than large species

Instabilities in a continuous medium model for the retina

Abstract. The shape of the spatial response of the retina on a small light stimulus as found b

A General Treatment of Solubility 4. Description and Analysis of a PCA Model for Ostwald Solubility Coefficients

Article discussing a general treatment of solubility and a description and analysis of a principal component analysis (PCA) model for Ostwald solubility coefficients

Poor accuracy of freehand cup positioning during total hip arthroplasty

Several studies have demonstrated a correlation between the acetabular cup position and the risk of dislocation, wear and range of motion after total hip arthroplasty. The present study was designed to evaluate the accuracy of the surgeon’s estimated position of the cup after freehand placement in total hip replacement. Peroperative estimated abduction and anteversion of 200 acetabular components (placed by three orthopaedic surgeons and nine residents) were compared with measured outcomes (according to Pradhan) on postoperative radiographs. Cups were placed in 49.7° (SD 6.7) of abduction and 16.0° (SD 8.1) of anteversion. Estimation of placement was 46.3° (SD 4.3) of abduction and 14.6° (SD 5.9) of anteversion. Of more interest is the fact that for the orthopaedic surgeons the mean inaccuracy of estimation was 4.1° (SD 3.9) for abduction and 5.2° (SD 4.5) for anteversion and for their residents this was respectively, 6.3° (SD 4.6) and 5.7° (SD 5.0). Significant differences were found between orthopaedic surgeons and residents for inaccuracy of estimation for abduction, not for anteversion. Body mass index, sex, (un)cemented fixation and surgical approach (anterolateral or posterolateral) were not significant factors. Based upon the inaccuracy of estimation, the group’s chance on future cup placement within Lewinnek’s safe zone (5–25° anteversion and 30–50° abduction) is 82.7 and 85.2% for anteversion and abduction separately. When both parameters are combined, the chance of accurate placement is only 70.5%. The chance of placement of the acetabular component within 5° of an intended position, for both abduction and anteversion is 21.5% this percentage decreases to just 2.9% when the tolerated error is 1°. There is a tendency to underestimate both abduction and anteversion. Orthopaedic surgeons are superior to their residents in estimating abduction of the acetabular component. The results of this study indicate that freehand placement of the acetabular component is not a reliable method