Implications of macrophyte abundance on algal growth management: The case of three natural swimming pools with distinct macrophyte abundance

Natural swimming pools are small constructed lakes for recreational proposes. They are composed by a swimming area merging with an area planted with emergent and submerged macrophytes, which function as biological filters. Fish are absent, however a wide diversity of phytoplankton, zooplankton and macroinvertebrate species colonize these pools. Therefore, pools can be regarded as the ideal systems to extrapolate the implications of macrophyte abundance management on algal growth control. The present study was taken in three pools (A, B and C) located in Minho Region (Northern Portugal) In early summer the macrophyte area had a 30% of cover in Pool A, in B 40% and in C 60%. Phytoplankton, zooplankton and filamentous algae abundance as well as conductivity, pH, dissolved oxygen, hardness, nitrates, nitrites, ammonia, phosphates were recorded in February, April and June. The lowest densities of phytoplankton were observed in pool C. Besides, filamentous algae were abundant in the pool A, whereas in B and C they were recorded only in summer. In Pool A, zooplankton assemblage was always dominated specialists on small particle feeding, which food preference are detritus and bacteria. Conversely, in the Pool C herbivorous zooplankton was predominant. The low algal densities observed in the Pool C are explained by the presence of a well established macrophyte assemblage. These plants contribute to the reduction of algal densities by (1) creating of areas of shade; (2) removing nutrients from water column and (3) provide refuges for herbivorous zooplankton. Therefore, the present study stresses the pertinence of take in account the key role of aquatic macrophytes when management practices for algal growth control are developed

General self-efficacy scale (GSE). Outcomes measurement tool: attitudes & feelings - self-efficacy.

The ten-item General Self-Efficacy Scale is correlated to emotion, optimism and work satisfaction. Negative coefficients were found for depression, stress, health complaints, burnout, and anxiety

Evidence that process simulations reduce anxiety in patients receiving dental treatment: randomized exploratory trial

Process simulations – mental simulations that ask people to imagine the process of completing a task – have been shown to decrease anxiety in students facing hypothetical or psychological threats in the short term. The aim of the present study was to see whether process simulations could reduce anxiety in a sample of the general population attending a dental practice, and whether these effects could be sustained throughout treatment. Participants (N = 75) were randomized to an experimental condition where they were asked to simulate mentally the process of seeing the dentist, or to a control condition where they were asked to simulate mentally the outcome of seeing the dentist. Findings showed that participants in the experimental condition were significantly less anxious both before and after their consultations. Self-efficacy and self-esteem remained unchanged. This study suggests that process simulation is one active ingredient in anxiety treatment programs and further research is required to enhance its effects

Fluid Induced Particle Size Segregation in Sheared Granular Assemblies

We perform a two-dimensional molecular-dynamics study of a model for sheared bidisperse granular systems under conditions of simple shear and Poiseuille flow. We propose a mechanism for particle-size segregation based on the observation that segregation occurs if the viscous length scale introduced by a liquid in the system is smaller than of the order of the particle size. We show that the ratio of shear rate to viscosity must be small if one wants to find size segregation. In this case the particles in the system arrange themselves in bands of big and small particles oriented along the direction of the flow. Similarly, in Poiseuille flow we find the formation of particle bands. Here, in addition, the variety of time scales in the flow leads to an aggregation of particles in the zones of low shear rate and can suppress size segregation in these regions. The results have been verified against simulations using a full Navier-Stokes description for the liquid.Comment: 11 pages, REVTEX format, ps figures compressed uuencoded separately or by e-mail from [email protected]. A postscript version of the paper will be available from http://www.ica1.uni-stuttgart.de/local/WWW/papers/papers.htm

Notch pathway inhibition controls myeloma bone disease in the murine MOPC315.BM model

Despite evidence that deregulated Notch signalling is a master regulator of multiple myeloma (MM) pathogenesis, its contribution to myeloma bone disease remains to be resolved. Notch promotes survival of human MM cells and triggers human osteoclast activity in vitro. Here, we show that inhibition of Notch through the γ-secretase inhibitor XII (GSI XII) induces apoptosis of murine MOPC315.BM myeloma cells with high Notch activity. GSI XII impairs murine osteoclast differentiation of receptor activator of NF-κB ligand (RANKL)-stimulated RAW264.7 cells in vitro. In the murine MOPC315.BM myeloma model GSI XII has potent anti-MM activity and reduces osteolytic lesions as evidenced by diminished myeloma-specific monoclonal immunoglobulin (Ig)-A serum levels and quantitative assessment of bone structure changes via high-resolution microcomputed tomography scans. Thus, we suggest that Notch inhibition through GSI XII controls myeloma bone disease mainly by targeting Notch in MM cells and possibly in osteoclasts in their microenvironment. We conclude that Notch inhibition is a valid therapeutic strategy in MM