42 research outputs found

    Nitrogen uptake and internal recycling in Zostera marina exposed to oyster farming: eelgrass potential as a natural biofilter

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    Oyster farming in estuaries and coastal lagoons frequently overlaps with the distribution of seagrass meadows, yet there are few studies on how this aquaculture practice affects seagrass physiology. We compared in situ nitrogen uptake and the productivity of Zostera marina shoots growing near off-bottom longlines and at a site not affected by oyster farming in San Quintin Bay, a coastal lagoon in Baja California, Mexico. We used benthic chambers to measure leaf NH4 (+) uptake capacities by pulse labeling with (NH4)-N-15 (+) and plant photosynthesis and respiration. The internal N-15 resorption/recycling was measured in shoots 2 weeks after incubations. The natural isotopic composition of eelgrass tissues and vegetative descriptors were also examined. Plants growing at the oyster farming site showed a higher leaf NH4 (+) uptake rate (33.1 mmol NH4 (+) m(-2) day(-1)) relative to those not exposed to oyster cultures (25.6 mmol NH4 (+) m(-2) day(-1)). We calculated that an eelgrass meadow of 15-16 ha (which represents only about 3-4 % of the subtidal eelgrass meadow cover in the western arm of the lagoon) can potentially incorporate the total amount of NH4 (+) excreted by oysters (similar to 5.2 x 10(6) mmol NH4 (+) day(-1)). This highlights the potential of eelgrass to act as a natural biofilter for the NH4 (+) produced by oyster farming. Shoots exposed to oysters were more efficient in re-utilizing the internal N-15 into the growth of new leaf tissues or to translocate it to belowground tissues. Photosynthetic rates were greater in shoots exposed to oysters, which is consistent with higher NH4 (+) uptake and less negative delta C-13 values. Vegetative production (shoot size, leaf growth) was also higher in these shoots. Aboveground/belowground biomass ratio was lower in eelgrass beds not directly influenced by oyster farms, likely related to the higher investment in belowground biomass to incorporate sedimentary nutrients

    Haematopoietic SCT in severe autoimmune diseases: updated guidelines of the European Group for Blood and Marrow Transplantation

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    In 1997, the first consensus guidelines for haematopoietic SCT (HSCT) in autoimmune diseases (ADs) were published, while an international coordinated clinical programme was launched. These guidelines provided broad principles for the field over the following decade and were accompanied by comprehensive data collection in the European Group for Blood and Marrow Transplantation (EBMT) AD Registry. Subsequently, retrospective analyses and prospective phase I/II studies generated evidence to support the feasibility, safety and efficacy of HSCT in several types of severe, treatment-resistant ADs, which became the basis for larger-scale phase II and III studies. In parallel, there has also been an era of immense progress in biological therapy in ADs. The aim of this document is to provide revised and updated guidelines for both the current application and future development of HSCT in ADs in relation to the benefits, risks and health economic considerations of other modern treatments. Patient safety considerations are central to guidance on patient selection and HSCT procedural aspects within appropriately experienced and Joint Accreditation Committee of International Society for Cellular Therapy and EBMT accredited centres. A need for prospective interventional and non-interventional studies, where feasible, along with systematic data reporting, in accordance with EBMT policies and procedures, is emphasized

    Items for developing revised classification criteria in systemic sclerosis: Results of a consensus exercise with the ACR/EULAR working committee for classification criteria in systemic sclerosis.

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    Background Classification criteria for systemic sclerosis (SSc) are being updated. Objective To select a set of items potentially useful for the classification of SSc using consensus procedures including the Delphi and nominal group techniques (NGT). Methods Items were identified through two independent consensus exercises performed by the Scleroderma Clinical Trials Consortium (SCTC) and the EULAR Scleroderma Trials and Research Group (EUSTAR). The first-round items from both exercises were collated and redundancies were removed leaving 168 items. A 3-round Delphi exercise was performed using a 1–9 scale (1=completely inappropriate and 9=completely appropriate) and a consensus meeting using NGT. During the last Delphi, the items were ranked on a 1–10 scale. Results Round 1: 106 experts rated the 168 items. Those with a median score <4 were removed, resulting in a list of 102 items. Round 2: The items were again rated for appropriateness and subjected to a consensus meeting using NGT by European and North American SSc experts (n=16), resulting in 23 items. Round 3: SSc experts (n=26) then individually scored each of the 23 items in a last Delphi round, using an appropriateness score (1–9) and ranking their 10 most appropriate items for classification of SSc. Presence of skin thickening, SSc-specific autoantibodies, abnormal nailfold capillary pattern and Raynaud’s phenomenon ranked highest in the final list that also included items indicating internal organ involvement. Conclusion The Delphi exercise and NGT resulted in a set of 23 items for classification of SSc which will be assessed for their discriminative properties in a prospective study
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