In the sediment of the shallow, hypertrophic Lake Sønderby, Denmark, potentially mobile phosphorus (Pmobile) was determined by a sequential extraction technique as the sum of porewater P, iron-bound P, and nonreactive P (i.e., polyphosphates and organic P). A good agreement was observed between loss rates of Pmobile in the top 10 cm of the sediment from winter to summer, P release rates measured in undisturbed sediment cores, and rates of P accumulation in the lake water from winter to summer (22, 32, and 30 mg of P m(-2) day(-1), respectively). This suggests that the operationally defined Pmobile was the sediment P fraction responsible for the internal loading in the lake. In autumn 2001, 11 mg of aluminum (Al) L(-1), equivalent to 31 g of Al m(-2), was added to the lake water. This dosage represented a 4:1 molar ratio between Al and Pmobile. The Al treatment significantly decreased lake water P, and P precipitated from the lake water was recovered as Al-bound P in the sediment after the treatment. Internal P loading was reduced by 93% in the two posttreatment years, relative to 2001. Accordingly, average summer concentrations of total P in lake water declined from 1.28 (SE = 0.17) and 1.3 (SE = 0.14) mg L(-1) in the two pretreatment years to 0.09 (SE = 0.01) and 0.13 (SE = 0.01) mg L(-1) in the posttreatment years. pH levels remained unchanged relative to pretreatment levels, while the total alkalinity was reduced from 3.2 (SE = 0.04) to 2.7 (SE = 0.03) mequiv L(-1).

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Although adipose-derived stromal cells (ADSCs) have been a major focus as an alternative to autologous bone graft in orthopedic surgery, bone formation potential of ADSCs is not well known and cytokines as osteogenic inducers on ADSCs are being investigated. This study aimed at isolating ADSCs from ovine adipose tissue (AT) and optimizing osteogenic differentiation of ovine ADSCs (oADSC) by culture medium and growth factors. Four AT samples were harvested from two female ovine (Texel/Gotland breed), and oADSCs were isolated and analyzed by flow cytometry for surface markers CD29, CD44, CD31, and CD45. Osteogenic differentiation was made in vitro by seeding oADSCs in osteogenic induction medium (OIM) containing fibroblast growth factor basic (FGFb), bone morphogenetic protein 2 (BMP2), or NEL-like molecule 1 (NELL1) in 4 different dosages (1, 10, 50, and 100 ng/ml, respectively). Basic medium (DMEM) was used as control. Analysis was made after 14 days by Alizarin red staining (ARS) and quantification. This study successfully harvested AT from ovine and verified isolated cells for minimal criteria for adipose stromal cells which suggests a feasible method for isolation of oADSCs. OIM showed significantly higher ARS to basic medium, and FGFb 10 ng/ml revealed significantly higher ARS to OIM alone after 14 days.