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The purpose of this study was to investigate the effects of self-selected respite music on upper-body resistance exercise performance. In a crossover, counterbalanced study design, resistance-trained males ( n = 10) participated in two bench press trials each with a different condition: 1) No music (NM), 2) Listening to respite music (RM; i.e. during rest periods). Following a warm-up, participants completed 3 sets × repetitions to failure (RTF) at 75% of 1-RM separated by 2 minutes of rest. During the 2-minute rest, participants either listened to NM or RM until the next subsequent set. A linear position transducer was used to measure mean barbell velocity during the first 3 repetitions and averaged for analysis. Rate of perceived exertion (RPE) and motivation were obtained after each set. Results indicate that mean velocity was higher during set 2 ( p = 0.009; d = 1.34) and set 3 ( p = 0.048; d = 0.95) while listening to RM versus NM. Furthermore, motivation was significantly higher following set 2 ( p = 0.005; d = 1.15) and set 3 ( p < 0.001; d = 1.79) while listening to RM compared to NM. No changes in RTF or RPE were noted between conditions ( p > 0.05). These findings indicate listening to music during recovery may enhance subsequent explosive resistance performance and suggest that listening to music in between bouts of maximal effort could be an effective tool for optimizing performance during competition or training.

Different environmental conditions support optimal growth by Aphanizomenon and Microcystis in Ford Lake, Michigan, USA, based on weekly species biovolume and water chemistry measurements from June through October 2005-2007. Experimental withdrawal of hypolimnetic water through the outlet dam was conducted in 2006, with 2005 and 2007 acting as control years, to test theory regarding management of nuisance and toxic cyanobacteria. The dynamics of Aphanizomenon and Microcystis blooms in Ford Lake appear to be driven largely by NO3(-) concentrations, with higher levels shifting the advantage to Microcystis (P<0.0001). Aphanizomenon was most successful with a mean TN:TP ratio (mol:mol) of 48.3:1, whereas Microcystis thrived with a mean ratio of 70.1:1. Withdrawal of hypolimnetic water successfully destabilized the water column and led to higher levels of NO3(-) and the near elimination of the Aphanizomenon bloom in 2006 (P<0.0001). Selective withdrawal did not reduce Microcystis biovolume or microcystin toxicity. Microcystis biovolume and NO3(-) levels were positively correlated with microcystin toxin (P=0.01) and jointly accounted for 30.5% of the variability in the data. Selective withdrawal may be a viable management option for improving water quality under certain circumstances. To fully address the problem of nuisance and toxic algal blooms in Ford Lake, however, an integrated approach is required that targets cyanobacteria biovolume dynamics as well as conditions suited for toxin production.

Spring development of diatoms in Ford Lake, Michigan, USA was markedly different in 2004 from 2005 and 2006. In 2004, diatom biovolume surpassed 15 mm(3)l(-1) but in 2005 and 2006 maximum biovolume was less than 5 mm(3)l(-1). Soluble reactive silica (SRSi) in 2004 fell below 5 microM whereas in 2005 and 2006, SRSi remained above 30 microM. Taxonomic composition was similar among years and consisted mainly of Asterionella, Cyclotella, Fragilaria, Aulacoseira, and Synedra. Bioassay experiments in 2005 demonstrated that P rather than Si was the element most limiting biomass development. However, P supply rate did not account for the differences among years. Model simulations of Si uptake, washout rates, and sinking implicated hydrologic differences among years as the cause of differential success by diatom populations in April of each year. Bioassay experiments performed after overturn demonstrated that diatoms could grow well in unamended lake water, but they did not flourish in the lake; model simulations implicated sinking losses as the reason. In summer 2006, we performed a selective withdrawal of hypolimnetic water from the outlet dam and weakened density stratification. An Aulacoseira bloom resulted in early to mid-August, depleting SRSi to less than 30 microM. The lake, which had been acting as a P source, changed to a P sink during the bloom, and cyanobacteria did not develop as they had in all previous years. Stoichiometric calculations indicate that the net SRSi uptake and the net DP uptake during the induced bloom were consistent with diatom production.

Both track autoradiography and grain-density autoradiography show that individual zooplankton create miniature patches of dissolved nutrients and that algae exploit those regions to absorb phosphate. The patches are short lived and can be dispersed artificially by small-scale turbulence. Our data support a simple model of encounters between algae and nutrient plumes produced by swimming zooplankton.

Autoradiography was used to identify the presence of nutrient patches produced by zooplankton. Algal cells which encounter patches of phosphorus-33 released by swimming animals accumulate more label than cells that do not enter the patches. Differential labeling of algae does not occur when turbulence in the fluid is increased by stirring. Nutrient patchiness at the scale of millimeters or less in nature probably influences the course of competition and coexistence among the phytoplankton.

Bythotrephes cederstroemii Schoedler, a predatory freshwater zooplankter (Crustacea: Cladocera), was first found in the Laurentian Great Lakes in December 1984. The first individuals were from Lake Huron, followed in 1985 with records from Lakes Erie and Ontario. By late August, 1986 the species had spread to southern Lake Michigan (43°N). Bythotrephes has not previously been reported from North America, but has been restricted to a northern and central Palearctic distribution. Its dramatic and widespread rise in abundance in Lake Michigan was greatest in offshore regions. Bythotrephes appears to be invading aggressively, but avoiding habitats presently occupied by glacio-marine relict species that became established in deep oligotrophic North American lakes after the Wisconsin glaciation. Because it is a voracious predator its invasion may lead to alterations in the native zooplankton fauna of the Great Lakes. It offers the chance to study how invading plankton species join an existing community. Judging from its persistence and success in deep European lakes, Bythotrephes may now become a permanent member of zooplankton communities in the Nearctic.