Observations of floating anthropogenic litter in the Barents Sea and Fram Strait,Arctic

Although recent reports indicate that anthropogenic waste has made it to the remotest parts of our oceans, there is still only limited information about its spread, especially in polar seas. Here, we present litter densities recorded during ship- and helicopter-based observer surveys in the Barents Sea and Fram Strait (Arctic). Thirty-one items were recorded in total, 23 from helicopter and eight from research vessel transects. Litter quantities ranged between 0 and 0.216 items km^?1 with a mean of 0.001 (±SEM 0.005) items km^?1. All of the floating objects observed were plastic items. Litter densities were slightly higher in the Fram Strait (0.006 items km^?1) compared with the Barents Sea (0.004 items km^?1). More litter was recorded during helicopter-based surveys than during ship-based surveys (0.006 and 0.004 items km^?1, respectively). When comparing with the few available data with the same unit (items km^?1 transect), the densities found herein are slightly higher than those from Antarctica but substantially lower than those from temperate waters. However, since anthropogenic activities in the Fram Strait are expanding because of sea ice shrinkage, and since currents from the North Atlantic carry a continuous supply of litter to the north, this problem is likely to worsen in years to come unless serious mitigating actions are taken to reduce the amounts of litter entering the oceans.     

Summer social structure of crabeater seal <Emphasis Type="Italic">Lobodon carcinophaga</Emphasis> in the Amundsen Sea,Antarctica

During the PS75 expedition of ice-breaking RV Polarstern in the Amundsen Sea, in February–March 2010, we studied the at-sea quantitative distribution of the “upper trophic levels,” seabirds and marine mammals. In the Amundsen Sea Embayment, 14,200 pinnipeds belonging to four species were recorded (2100 during 670 half-hour transect counts from the bridge and 12,100 during 50 h of helicopter flight). Crabeater seal Lobodon carcinophaga represented more than 97 % of the total. Two types of major aggregations of crabeaters were noted: on the one hand, very large groups hauled out on the pack ice, composed mainly of adults/bachelors and very few calves. On the other hand, swimming pods of calves were accompanied by one or two leading adults around icebergs. Our interpretation is that, after the beginning of the reproduction period with trios (cow, calf and future father) scattered on pack ice, such pods can be considered the last step of the breeding cycle.     

Fate of metallic engineered nanomaterials in constructed wetlands: prospection and future research perspectives

Metallic engineered nanomaterials (ENMs) undergo various transformations in the environment which affect their fate, toxicity and bioavailability. Although constructed wetlands (CWs) are applied as treatment systems for waste streams potentially containing metallic ENMs, little is known about the fate and effects of ENMs in CWs. Hence, literature data from related fields such as activated sludge wastewater treatment and natural wetlands is used to predict the fate and effects of ENMs in CWs and to analyze the risk of nanomaterials being released from CWs into surface waters. The ENMs are likely to reach the CW (partly) transformed and the transformations will continue in the CW. The main transformation processes depend on the type of ENM and the ambient environmental conditions in the CW. In general, ENMs are expected to undergo sorption onto (suspended) organic matter and plant roots. Although the risk of ENMs being released at high concentrations from CWs is estimated low, caution is warranted because of the estimated rise in the production of these materials. As discharge of (transformed) ENMs from CWs during normal operation is predicted to be low, future research should rather focus on the effects of system malfunctions (e.g. short-circuiting). Efficient retention in the CW and increasing production volumes in the future entail increasing concentrations within the CW substrate and further research needs to address possible adverse effects caused.     

Towards ecological goals for the heavily modified lakes in the IJsselmeer area,The Netherlands

The European Water Framework Directive (WFD) obliges EU member states to define ecological goals for water bodies and, if necessary, to take measures to achieve these goals by 2015. The goals and measures for the water bodies in the IJsselmeer area of The Netherlands are elaborated in this study, following an approach described by Irmer &; Pollard (2006, Alternative methodology for defining Good Ecological Potential (GEP) for Heavily Modified Water Bodies (HMWB) and Artificial Water Bodies (AWB). ECOSTAT). With the closure of the Afsluitdijk in 1932, the former Southern Sea estuary was transformed into the freshwater Lake IJsselmeer. Subsequently, a string of so-called border lakes and Lake Markermeer were created by land reclamation projects and the construction of dams. These alterations serve safety, provide drinking water supplies and created agricultural land. Owing to the change in category, the lakes are by (WFD) definition heavily modified. A natural lake rather than an estuary will be the starting point for determining ecological potential. However, damming and fixing the water table prevented the development of emergent vegetation and caused steep water-land gradients. The Maximum Ecological Potential includes the effect of these hydromorphological changes after all mitigation measures have been considered. Other pressures on the lakes are high nutrient loads, which cause phytoplankton blooms, the disappearance of aquatic macrophytes and intensive fishery, which overexploites the pikeperch and eel populations and causes indirect negative effects on water quality. Good Ecological Potential for these lakes is derived by estimating the effects of all effective hydromorphological measures that have no significant negative impact on existing functions or the wider environment, and the effects of all other measures. The suggested main measures are: construction of fish passages, adaptation of shore-lines, wind sheltered areas, reduction of nutrient load, reduction of fishery pressure and reduction of the bream stock. The effects of these measures are calculated from multivariate analyses that establish the relationships between (a) nutrients and chlorophyll-a, (b) chlorophyll-a and water transparency, (c) water transparency, depth distribution and vegetation coverage and (d) vegetation coverage and fish community. The proposed goals will be refined using new scientific insights and further discussions with stakeholders, and will finally be reported in the River Basin Management Plan 2009. It is expected that exemptions will be used for a phased achievement of the objectives.     

Cellular localization of a plant protein PSAM 1 in arbuscular mycorrhizas of Pisum sativum

Psam 1 is a single-copy gene which is activated during early plant-fungal interaction in wild-type pea inoculated with Glomus mosseae and which codes for PSAM 1, a putative protein of 108 amino acids. A synthetic peptide was designed in an antigenic region of this protein to produce a polyclonal antibody against PSAM 1 and to investigate its cellular localization. Western blot analysis revealed that a polypeptide of about 14.5 kDa accumulated more in mycorrhizal than non-mycorrhizal pea roots. The PSAM 1 antigen was immunolocated in planta in arbuscule-containing cells of mycorrhizal roots and especially in the cytoplasm surrounding young arbuscules in cortical cells, which suggests that its accumulation is somehow related to the symbiotic state of these cells. Received: 27 June 1998 / Accepted: 27 July 1998     

Development and activity of Glomus intraradices as affected by co-existence with Glomus claroideum in one root system

The co-existence of two arbuscular mycorrhizal fungal (AMF) species, Glomus intraradices and Glomus claroideum, in the root systems of plants was investigated in a greenhouse experiment aimed at reconstructing interactions during an early stage of primary succession on a coal-mine spoil bank in Central Europe. Two plant species, Tripleurospermum inodorum and Calamagrostis epigejos, were inoculated either with one or both AMF species. Fungal development, determined by trypan blue and alkaline phosphatase staining as well as by PCR amplification of rRNA genes with species-specific primers, and the expression of five genes with different metabolic functions in the intraradical structures of G. intraradices were followed after 6 and 9 weeks of cultivation. The two AMF closely co-existed in the root systems of both plants possibly through similar colonisation rates and competitivity. Inoculation with the two fungi, however, did not bring any additional benefit to the host plants in comparison with single inoculation; moreover, plant growth depression observed after inoculation with G. claroideum persisted also in mixed inoculation. The expression of all the assayed G. intraradices genes was affected either by host plant or by co-inoculation with G. claroideum. The effects of both factors depended on the time of sampling, which underlines the importance of addressing this topic in time-course studies.     

Patients lacking classical poor prognostic markers might also benefit from a step-down glucocorticoid bridging scheme in early rheumatoid arthritis: week 16 results from the randomized multicenter CareRA trial

IntroductionConsidering a lack of efficacy data in patients with early rheumatoid arthritis (eRA) presenting without classical markers of poor prognosis, we compared methotrexate (MTX) with or without step-down glucocorticoids in the CareRA trial.MethodsDisease-modifying antirheumatic drug–naïve patients with eRA were stratified into a low-risk group based on prognostic markers that included non-erosiveness, anti–citrullinated protein antibodies and rheumatoid factor negativity and low disease activity (Disease Activity Score in 28 joints based on C-reactive protein (DAS28(CRP)) ≤3.2). Patients were randomized to 15 mg of MTX weekly (MTX with tight step-up (MTX-TSU)) or 15 mg of MTX weekly with prednisone bridging, starting at 30 mg and tapered to 5 mg daily from week 6 (COmbinatie therapie bij Reumatoïde Artritis (COBRA Slim)). A TSU approach was applied. Outcomes assessed were DAS28(CRP)-determined remission, cumulative disease activity, Health Assessment Questionnaire (HAQ) scores and adverse events (AEs) after 16 treatment weeks.ResultsWe analyzed 43 COBRA Slim and 47 MTX-TSU patients and found that 65.1% in the COBRA Slim group and 46.8% in the MTX-TSU group reached remission (P = 0.081). Mean ± standard deviation area under the curve values of DAS28(CRP) were 13.84 ± 4.58 and 11.18 ± 4.25 for the MTX-TSU and COBRA Slim patients, respectively (P = 0.006). More COBRA Slim patients had an HAQ score of 0 (51.2% versus 23.4%, P = 0.006) at week 16. Therapy-related AEs between groups did not differ.ConclusionIn patients with low-risk eRA, MTX with step-down glucocorticoid bridging seems more efficacious than MTX step-up monotherapy, with a comparable number of AEs observed over the first 16 treatment weeks.

Trial registration

EU Clinical Trials Register Identifier: EudraCT number 2008-007225-39. Registered 5 November 2008.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0611-8) contains supplementary material, which is available to authorized users.     

Niche conservatism among non‐native vertebrates in Europe and North America

Niche conservatism, the hypothesis that niches remain constant through time and space, is crucial for the study of biological invasions as it underlies native‐range based predictions of invasion risk. Niche changes between native and non‐native populations are increasingly reported. However, it has been argued that these changes arise mainly because in their novel range, species occupy only a subset of the environments they inhabit in their native range, and not because they expand into environments entirely novel to them. Here, using occurrences of 29 vertebrate species native to either Europe or North America and introduced into the other continent, we assess the prevalence of niche changes between native and non‐native populations and assess whether the changes detected are caused primarily by native niche unfilling in the non‐native range rather than by expansion into novel environments. We show that niche overlap between native and non‐native populations is generally low because of a large degree of niche unfilling in the non‐native range. This most probably reflects an ongoing colonization of the novel range, as niche changes were smaller for species that were introduced longer ago and into a larger number of locations. Niche expansion was rare, and for the few species exhibiting larger amounts of niche overlap, an unfilling of the niche in the native range (e.g. through competition or dispersal limitations) is the most probable explanation. The fact that for most species, the realized non‐native niche is a subset of the realized native niche allows native‐range based niche models to generate accurate predictions of invasion risk. These results suggest that niche changes arising during biological invasions are strongly influenced by propagule pressure and colonization processes, and we argue that introduction history should be taken into account when evaluating niche conservatism in the context of biological invasions.