Forecasting the combined effects of anticipated climate change and agricultural conservation practices on fish recruitment dynamics in Lake Erie

Many aquatic ecosystems are experiencing multiple anthropogenic stressors that threaten their ability to support ecologically and economically important fish species. Two of the most ubiquitous stressors are climate change and non- point source nutrient pollution.Agricultural conservation practices (ACPs, i.e. farming practices that reduce runoff, prevent erosion, and curb excessive nutrient loading) offer a potential means to mitigate the negative effects of non- point source pollution on fish populations. However, our understanding of how ACP implementation amidst a changing climate will affect fish production in large ecosystems that receive substantial upstream sediment and nutrient inputs remains incomplete.Towards this end, we explored how anticipated climate change and the implementation of realistic ACPs might alter the recruitment dynamics of three fish populations (native walleye Sander vitreus and yellow perch Perca flavescens and invasive white perch Morone americana) in the highly productive, dynamic west basin of Lake Erie. We projected future (2020- 2065) recruitment under different combinations of anticipated climate change (n = 2 levels) and ACP implementation (n = 4 levels) in the western Lake Erie catchment using predictive biological models driven by forecasted winter severity, spring warming rate, and Maumee River total phosphorus loads that were generated from linked climate, catchment- hydrology, and agricultural- practice- simulation models.In general, our models projected reduced walleye and yellow perch recruitment whereas invasive white perch recruitment was projected to remain stable or increase relative to the recent past. Our modelling also suggests the potential for trade- offs, as ACP implementation was projected to reduce yellow perch recruitment with anticipated climate change.Overall, our study presents a useful modelling framework to forecast fish recruitment in Lake Erie and elsewhere, as well as offering projections and new avenues of research that could help resource management agencies and policy- makers develop adaptive and resilient management strategies in the face of anticipated climate and land- management change.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156436/2/fwb13515.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156436/1/fwb13515_am.pd

Response of streambreeding salamander larvae to sediment deposition in southern Appalachian (U.S.A.) headwater streams

SUMMARY 1. Increased fine sediment deposition is a prevalent threat to stream biodiversity and has been shown to impact stream-breeding salamanders negatively. However, their complex life histories make it difficult to determine which stage is affected. 2. We conducted field experiments from 26 August to 11 September 2010 and 11 October to 11 November 2010 in two southern Appalachian headwater streams (U.S.A.) to examine the response of larval salamanders to increased fine sediment deposition. Fine sediment was increased in artificial stream channels by 0, 33 and 67%. The number of larvae observed at the end of the experiments was used to determine whether larval microhabitat selection was influenced by fine sediment deposition. A concurrent survey of aquatic larvae in three nearby streams complemented this experiment. Stream substratum composition at survey sites was quantified to examine the effects of fine sediment on larval salamander abundance. 3. Increases in fine sediment deposition failed to explain the number of larval salamanders detected in stream channels. Similarly, a negligible effect of fine sediment was observed on abundance estimates. 4. These results suggest that fine sediment deposition has a minimal impact on aquatic salamander larvae. Therefore, the effects of increased fine sediment loads on stream-breeding salamanders may not be the result of deleterious effects on the aquatic larvae but instead may be the result of effects on other stages. Management efforts that consider these other stages are therefore needed to protect stream-breeding salamander communities

Perturbations of peripheral B lymphocyte homoeostasis in children with systemic lupus erythematosus

Objective: To investigate the distribution of peripheral B cell subpopulations of children with active and inactive systemic lupus erythematosus (SLE) compared with healthy controls. Methods: Peripheral B cell subpopulations of 11 children with SLE (6 with active and 5 with inactive disease) and 14 age matched normal healthy children were analysed. Active disease was diagnosed in children with a flare of SLE, who received treatment by IV cyclophosphamide or IV methylprednisolone pulse to control the disease. Additionally, the peripheral B cells of the children with SLE were compared with those of 13 consecutive patients with adult onset SLE. Results: No major difference was found in the frequency and total number of CD27(-)/CD19(+) naïve B cells and CD27(+)/CD19(+) memory B cells between patients with active and inactive lupus and healthy controls, but there was a significant increase in CD27(high) expressing plasma blasts in patients with active SLE. These cells coexpress CD38(+), HLA-DR(dim), surface Ig(low) and lack the expression of CD20 but are clearly positive for intracellular Ig, indicative of early plasma cells. Most CD138(+) cells coexpress CD27(high)/CD19(+). The enhanced frequency of peripheral plasma blasts in children with active SLE is consistent with previous findings in adult patients with SLE, whereas a relative predominance of CD27(+) memory B cells was only identified in the adult patients. Conclusions: Profound abnormalities in the distribution of B cell compartments are more pronounced in older patients with SLE, but an enhanced frequency and cell number of peripheral plasma blasts is characteristic of both diseases during active stages. Thus detection of CD27(high) plasma blasts significantly correlates with active lupus in both children and adults

“Periodic fever” without fever: two cases of non‐febrile TRAPS with mutations in the TNFRSF1A gene presenting with episodes of inflammation or monosymptomatic amyloidosis

BACKGROUND: Tumour necrosis factor (TNF) receptor associated periodic syndrome (TRAPS) is caused by dominant mutations in the TNFRSF1A gene. In typical cases TRAPS begins early in childhood and is characterised by high and remittent fever over a period of 1–4 weeks or longer, accompanied by systemic and local inflammation. CASE REPORTS: Patient 1 presented with recurrent episodes of weakness, migrating myalgias, arthralgias, exanthema, and chest pain lasting for 1–4 weeks, but without any fever over an initial period of 4 years at least. Diagnosis of TRAPS was confirmed by the heterozygous mutation Y20H in TNFRSF1A. Patient 2, a 23 year old woman never had any symptoms indicative of TRAPS. Genetic evaluation of all members of her family with a TRAPS index patient disclosed the T50M mutation in TNFRSF1A. A medical check up showed proteinuria, and renal biopsy disclosed AA amyloidosis. CONCLUSIONS: TRAPS associated mutations can induce considerable inflammation that is not necessarily accompanied by fever. Even monosymptomatic severe amyloidosis can occur in these patients. Genetic counselling and appropriate management to prevent or mitigate amyloidosis may be necessary