Increasing demand for limited water supplies in populated arid regions over the next decade may require implementation of new water-use practices. Eliminating use of high-quality water for landscape irrigation by using low-quality water delivered through secondary systems is an ideal option for conserving potable water. However, irrigation of woody landscape plants using waters high in inorganic salts may adversely affect soil fertility, structure, plant growth and appearance. Twelve woody ornamentals commonly used in landscapes in Salt Lake County, Utah, were treated with three blends of Utah Lake and Provo River water to assess the quality of plants produced. Three irrigation treatments, designated high-, medium-, and low-quality water were blended to maintain sodium concentrations of 15, 80 and 120 mg/liter respectively. Soils irrigated with medium-and low-quality water developed significantly higher adjusted sodium absorption ratio (SAR) and salinity than soils irrigated with high quality water and the effect varied with time. Except for four species, medium-and low-quality water did not significantly lower scores for plant appearance. Results of this two-year study support development of secondary water systems and use of lower-quality water for landscape irrigation.

Receptors for Advanced Glycation End Products (RAGE) and Toll Like Receptor 4 (TLR‐4) have been shown to play a role in the development of Osteoarthritis (OA). We have previously shown that knocking out RAGE in mice slows the disease progression in articular cartilage of the knee. The objective of this study was to determine if application of the compound TAK‐242, a TLR‐4 specific inhibitor, in conjunction with knocking out RAGE could further attenuate the disease. Destabilization of the medial meniscus of RAGE KO and Wild Type (WT mice) was performed, and severity of OA was qualitatively analyzed through two standardized scoring systems (Mankin and OARSI). We also performed immunohistochemistry to analyze levels of HtrA1 and TGF‐β1, known biomarkers for the disease. Surprisingly, addition of the TLR blocker disrupted the protection afforded by knocking out RAGE, and its application to WT mice had no protective effect. We conclude that while blockage of the RAGE pathway alone is beneficial to the attenuation of OA, hampering the TLR‐4 pathway offers no protective benefits. We hypothesize that blocking TLR‐4 receptor mitigates the beneficial effects of knocking out RAGE on OA.

Prior research has indicated that a pathway exists in the molecular progression of Osteoarthritis (OA) involving key biomarkers HtrA1, Ddr‐2 and Mmp‐13. We and others have recently shown, by immunohisotchemical staining, that HtrA1 and TGF‐β1 show a unique, inverse relationship in OA. The objective of this research is to provide supporting data and clarification to this interaction via Enzyme‐Linked Immunosorbent Assay (ELISA) and quantitative Polymerase Chain Reaction (qPCR) analysis. Cartilage samples from the hip and synovial fluid samples form the knee of wild type (WT) mice, treated to induce OA, were assayed for quantitative presence of TGF‐β1 biomarker using ELISA and quantitative mRNA presence using qRTPCR. We observed initially high levels of TGF‐β1 protein that subsequently decreased 50% as OA progressed and became more severe over time. We hypothesize that TGF‐β1, as a cytokine growth factor, is over expressed in early OA resulting in an increased expression of HtrA1, a serine protease, which subsequently impairs TGF‐β1 cell maintenance activity and dooms the cell to apoptosis.