Host biology, ecology and the environment influence microbial biomass and diversity in 101 marine fish species.

Fish are the most diverse and widely distributed vertebrates, yet little is known about the microbial ecology of fishes nor the biological and environmental factors that influence fish microbiota. To identify factors that explain microbial diversity patterns in a geographical subset of marine fish, we analyzed the microbiota (gill tissue, skin mucus, midgut digesta and hindgut digesta) from 101 species of Southern California marine fishes, spanning 22 orders, 55 families and 83 genera, representing ~25% of local marine fish diversity. We compare alpha, beta and gamma diversity while establishing a method to estimate microbial biomass associated with these host surfaces. We show that body site is the strongest driver of microbial diversity while microbial biomass and diversity is lowest in the gill of larger, pelagic fishes. Patterns of phylosymbiosis are observed across the gill, skin and hindgut. In a quantitative synthesis of vertebrate hindguts (569 species), we also show that mammals have the highest gamma diversity when controlling for host species number while fishes have the highest percent of unique microbial taxa. The composite dataset will be useful to vertebrate microbiota researchers and fish biologists interested in microbial ecology, with applications in aquaculture and fisheries management.

A randomized, double-blind, placebo-controlled, parallel study to assess the efficacy and safety of once-a-day tadalafil in men with erectile dysfunction who are naïve to PDE5 inhibitors.

INTRODUCTION: The majority of subjects included in previous tadalafil once-a-day clinical trials were non-naïve to previous phosphodiesterase 5 (PDE5) inhibitors on demand. A study on PDE5 inhibitor naïve subjects was therefore warranted. AIM: To evaluate the efficacy and safety of once-a-day tadalafil in PDE5 inhibitor-naïve men with erectile dysfunction (ED). MAIN OUTCOMES MEASURES: Primary efficacy end points were changes from baseline to end point in the International Index of Erectile Function (IIEF) Erectile Function (EF) domain score and the per-subject proportion of "yes" responses to sexual encounter profile (SEP) question 2 (SEP2) and question 3 (SEP3). METHODS: PDE5 inhibitor-naïve men with ED (N=217) were randomized in a 1:2 ratio to receive placebo or tadalafil 5 mg once a day for 12 weeks. Enrollment began in January 2009 and the last subject completed in January 2010. RESULTS: At end point, least square mean change from baseline IIEF-EF domain score (7.3 vs. 3.4), SEP2 (23.8% vs. 12.2%) and SEP3 (39.5% vs. 21.5%), was significantly larger for tadalafil vs. placebo (all P<0.001). The most common adverse events (AEs) in tadalafil-treated subjects were back pain, nasopharyngitis, dyspepsia, headache, and myalgia. Four subjects (2.7%) in the tadalafil group and one subject (1.4%) in the placebo group discontinued because of AEs. CONCLUSIONS: In PDE5 inhibitor-naïve men, tadalafil once a day significantly improved EF compared with placebo. Safety results were consistent with previous tadalafil once-a-day clinical trials.

Acoustic characteristics of ultrasonic coded transmitters for fishery applications: could marine mammals hear them?

Ultrasonic coded transmitters (UCTs) producing frequencies of 69-83 kHz are used increasingly to track fish and invertebrates in coastal and estuarine waters. To address concerns that they might be audible to marine mammals, acoustic properties of UCTs were measured off Mission Beach, San Diego, and at the U.S. Navy TRANSDEC facility. A regression model fitted to VEMCO UCT data yielded an estimated source level of 147 dB re 1 µPa SPL @ 1 m and spreading constant of 14.0. Based on TRANSDEC measurements, five VEMCO 69 kHz UCTs had source levels ranging from 146 to 149 dB re 1 µPa SPL @ 1 m. Five Sonotronics UCTs (69 kHz and 83 kHz) had source levels ranging from 129 to 137 dB re 1 µPa SPL @ 1 m. Transmitter directionality ranged from 3.9 to 18.2 dB. Based on propagation models and published data on marine mammal auditory psychophysics, harbor seals potentially could detect the VEMCO 69 kHz UCTs at ranges between 19 and >200 m, while odontocetes potentially could detect them at much greater ranges. California sea lions were not expected to detect any of the tested UCTs at useful ranges.