Widespread and persistent oligotrophication of northern rivers.

Phosphorus (P) is often a limiting nutrient in freshwaters and most management actions aim to reduce eutrophication associated with excess anthropogenic P inputs. Here, we report on the opposite problem, persistent and widespread oligotrophication (i.e.

Trends in mercury, lead and cadmium concentrations in 27 European streams and rivers: 2000-2020.

Temporal trends for concentrations of mercury (Hg), lead (Pb) and cadmium (Cd) were evaluated from year 2000-2020 in 20 (Hg), 23 (Pb) and 11 (Cd) watercourses in remote forest catchments in Europe. Decreasing trends were observed in 15% (Hg), 39% (Pb) and 45% (Cd) of the watercourses during the period of evaluation. Decreasing trends were mainly observed between 2000 and 2005 for Hg and between 2000 and 2015 for Pb and Cd.

A model for predicting reduction in mobile phosphorus of lake sediment by aluminum drinking water treatment residuals.

Drinking water treatment residual (DWTR) derived from flocculation and sedimentation of raw water using aluminum coagulants is a valuable environmental remediation byproduct capable of inactivating phosphorus (P). However, no generalizable model exists in the literature to describe reduction of releasable (mobile) P in lake sediment as a result of DWTR addition. The reduction of mobile P (sum of labile P and reductant soluble P) was investigated in over 100 sub-samples using five sediment samples from two lakes and three DWTRs from different water treatment plants.

A 25-year retrospective analysis of factors influencing success of aluminum treatment for lake restoration.

For more than 50 years, aluminum (Al)-salts have been used with varying degrees of success to inactivate excess mobile phosphorus (P) in lake sediments and restore lake water quality. Here, we analyzed the factors influencing effectiveness and longevity of Al-treatments performed in six Swedish lakes over the past 25 years. Trends in post-treatment measurements of total phosphorus (TP), Chlorophyll a (Chl_a), Secchi disk depth (SD) and internal P loading rates (Li) were analyzed and compared to pre-treatment conditions.

Optimization of aluminum treatment efficiency to control internal phosphorus loading in eutrophic lakes.

Historical accumulation of phosphorus (P) in lake sediment often contributes to and sustains eutrophic conditions in lakes, even when external sources of P are reduced. The most cost-effective and commonly used method to restore the balance between P and P-binding metals in the sediment is aluminum (Al) treatment. The binding efficiency of Al, however, has varied greatly among treatments conducted over the past five decades, resulting in substantial differences in the amount of P bound per unit Al.

A comparison of aluminum dosing methods for reducing sediment phosphorus release in lakes.

Aluminum (Al) treatment is one of the most commonly used approaches to reduce internal phosphorus (P) loading in lakes. However, the adequate amount of Al that should be added to permanently inactivate mobile (releasable) sediment P can be determined using many different methods. These methods differ substantially in their specified design sediment depth, targeted P pool(s), and expected binding ratio.

Ecological resilience in lakes and the conjunction fallacy.

There is a pressing need to apply stability and resilience theory to environmental management to restore degraded ecosystems effectively and to mitigate the effects of impending environmental change. Lakes represent excellent model case studies in this respect and have been used widely to demonstrate theories of ecological stability and resilience that are needed to underpin preventative management approaches. However, we argue that this approach is not yet fully developed because the pursuit of empirical evidence to underpin such theoretically grounded management continues in the absence of an objective probability framework.

Persistent and widespread long-term phosphorus declines in Boreal lakes in Sweden.

We present an analysis of long-term (1988-2013; 26years) total phosphorus (TP) concentration trends in 81 Swedish boreal lakes subject to minimal anthropogenic disturbance. Near universal increases in dissolved organic carbon (DOC) concentrations and a widespread but hitherto unexplained decline in TP were observed. Over 50% of the lakes (n=42) had significant declining TP trends over the past quarter century (Sen's slope=2.

In-lake measures for phosphorus control: The most feasible and cost-effective solution for long-term management of water quality in urban lakes.

Both in-lake and catchment measures designed to reduce phosphorus (P) loading were implemented as part of a 12.3 million USD restoration project for the Minneapolis Chain of lakes in Minnesota (USA). Treatment wetlands, 'in-pipe' measures, and in-lake aluminum sulfate (alum) treatment were applied to restore water quality in the four urban lakes.

Longevity and effectiveness of aluminum addition to reduce sediment phosphorus release and restore lake water quality.

114 lakes treated with aluminum (Al) salts to reduce internal phosphorus (P) loading were analyzed to identify factors driving longevity of post-treatment water quality improvements. Lakes varied greatly in morphology, applied Al dose, and other factors that may have affected overall treatment effectiveness. Treatment longevity based on declines in epilimnetic total P (TP) concentration averaged 11 years for all lakes (range of 0-45 years).

Anthropogenic oligotrophication via liming: Long-term phosphorus trends in acidified, limed, and neutral reference lakes in Sweden.

Restoration of acidified lakes by liming does not, in many cases, improve productivity to a pre-acidified state. We hypothesize that the poor recovery detected in many of these lakes is due to constrained in-lake phosphorous (P) cycling caused by enhanced precipitation of metals in higher pH, limed waters. Long-term (1990-2012) data for 65 limed, circum-neutral (pH 6-8), and acidified lakes in Sweden were analyzed to determine trends for P and potential drivers of these trends.

A simple model for predicting aluminum bound phosphorus formation and internal loading reduction in lakes after aluminum addition to lake sediment.

The conversion of mobile phosphorus (P) to aluminum bound P (Al-P) after addition of Al to over 300 sub-samples from 35 sediment cores collected from 20 lakes in the upper Midwest, United States was investigated in this study. Consistent relationships between mobile P reduction and Al-P formation were detected across a broad range of mobile sediment P contents (0.04-2.

Prediction of reference phosphorus concentrations in Swedish lakes.

The relationship between total phosphorus (TP) and chemical, climatic, morphological, and geographic variables was examined for over a thousand reference lakes across Sweden. A significant relationship was found between TP and both absorbance of irradiance (at 420 nm, filtered) and altitude for all lakes. These two variables alone, however, were not able to adequately predict TP concentrations in naturally turbid lakes.

Variability in phosphorus binding by aluminum in alum treated lakes explained by lake morphology and aluminum dose.

Sediment cores from six aluminum sulfate treated lakes in Minneapolis, MN were analyzed to determine the effectiveness of phosphorus (P) binding by aluminum (Al). Two of the study lakes are polymictic and the remaining four are dimictic. Above background concentrations of Al and Al-bound-P (P(Al)) were detected in all six lakes at varying sediment depths.

A method for comparative evaluation of whole-lake and inflow alum treatment.

A method is described to evaluate two methods of phosphorus (P) management in lakes using aluminum sulfate (alum)--in-lake and tributary (inflow) treatment--and compare the resulting in-lake P levels. For in-lake treatment, a technique is described to calculate the optimum alum dose based on measurement of "mobile P" in lake sediments. Mobile P is defined as loosely sorbed and Fe-P, the fraction of sediment P subject to release under anoxic conditions.

Atrial natriuretic peptide release and volume regulation following kidney transplantation.

The major stimulus for atrial natriuretic peptide (ANP) release is atrial stretch and increased values are observed in volume overload states such as chronic renal failure. Since successful kidney transplantation restores volume homeostasis, we compared the effects of human cadaveric kidney transplantation on time course and changes of plasma ANP in the early postoperative period in 4 patients with successful and 4 patients with failed transplantation. ANP concentrations were elevated before transplantation in both groups (91 +/- 16 and 70 +/- 32 pmol/l) and decreased after successful (50 +/- 27 pmol/l, day 16) but increased after failed transplantation (146 +/- 45 pmol/l, day 16).

Risks and benefits of graft biopsy in renal transplantation under cyclosporin-A.

261 patients who received a kidney transplant under cyclosporin-A immunosuppression were reviewed in order evaluate the benefits and the risks of renal graft biopsies. 240 graft biopsies were performed in 124 of the 261 patients. The biopsy diagnoses were 103x rejection, 90x cyclosporin-A toxicity, 8x acute tubular necrosis, 8x glomerulonephritis, 9x different biopsy results, and 12 cases of normal renal tissue.

The efficacy and tolerability of cyclosporine G in human kidney transplant recipients.

Twelve consecutive first cadaveric kidney transplant recipients received cyclosporine G (CsG)(initial dose 12 mg/kg per day) as basic immunosuppressive treatment along with prednisone (initial dose 0.5 mg/kg per day) for the first three months after transplantation. Thereafter CsG was replaced by Sandimmun (cyclosporine, CsA).

Giant mitochondria in "zero-hour" transplant biopsies.

Giant mitochondria in kidneys have increasingly been observed since the introduction of Cyclosporin A (CSA) as immunosuppressant in kidney transplants and in patients with autoimmune disorders. In animals treated with CSA, giant mitochondria were also described. In a study of "zero-hour" biopsies taken immediately before or after reperfusion of the renal transplant, giant mitochondria were often unexpectedly found.

Renal graft rejection or cyclosporin toxicity? Early diagnosis by a combination of Papanicolaou and immunocytochemical staining of urinary cytology specimens.

A method is described for distinguishing between graft rejection and cyclosporin nephrotoxicity in renal allograft recipients by analyzing fresh morning urine samples. The technique combines classic Papanicolaou with immunocytochemical staining and was performed in urine specimens from a series of 42 patients. Early-stage cyclosporin toxicity was usually associated with increased numbers of proximal tubular cells only, whereas in rejection and late-stage toxicity there were increases in both tubular cells and in lymphocytes and monocytes (greater than 2000 cells/ml urine).

Early diagnosis of kidney transplant rejection and cyclosporin nephrotoxicity by urine cytology.

A total of 2000 urine samples from 53 kidney transplant recipients were studied to develop a routine method for the early diagnosis of rejection and cyclosporin (CSA) nephrotoxicity in urine. New-Sternheimer staining and an immunocytochemical technique were used together with classical Papanicolaou staining to differentiate cells in the urine. After cell count and differentiation of second morning urine samples with New-Sternheimer and Papanicolaou stains, immunocytochemistry was performed using antibodies against the following antigens: CD2, CD4, CD8, CD25, CD71 (transferrin receptor), HLA-DR and cytokeratin (Lu-5).