Computation of Dolphins' Sound ASPL While Foraging.

Scheduled scientific surveys are a valuable asset in beginning to understand the behavior and vocalization of free-ranging cetaceans. The fortuity of a nonscheduled survey has proven to be beneficial as well. In October 2003 a team of biologist oceanographers began a trip aboard a 44.29 feet catamaran sailing boat from Piraeus Greece to Cape Verde Archipelago intending to observe free-ranging cetaceans. Acoustic recordings were conducted using a towed stereophonic hydrophone array consisted of two Benthos AQ4 type hydrophones. Photographs were taken in order to ensure species identification. Information on vocalization administration during foraging of Lagenodelphis hosei and Steno bredanensis has been acquired. Calculation of ASPL (apparent source power level) revealed that dolphins' vocalizations did not match to usual vocalization activities. The relation of vocalization administration by dolphins with brain to mash ratio (BMR) is introduced as an additional predator's strategy.

Effect of marine litter on the benthic megafauna of coastal soft bottoms: a manipulative field experiment.

The effect of litter on the abundance and community structure of soft-bottom epibenthic megafauna was investigated in three coves of the Saronikos Gulf (Aegean Sea). At each site, two surfaces were defined on the sea-bottom. One of the surfaces was uniformly littered with debris (16 items per 100 m(2)), while the other remained 'clean' and acted as control. Benthic megafauna was censused with SCUBA diving, once before the littering episode and then monthly for one year. Both total abundance and the number of species showed an increasing trend in the impacted surfaces, either because the litter provided refuge or reproduction sites for mobile species or because hard-substratum sessile species had the opportunity to settle on provided surfaces. A marked gradual deviation in the community structure of the impacted surface from the control and a clear successional pattern of change in the community composition of the impacted surfaces were demonstrated.

Correlation between optical coherence tomography and multifocal electroretinogram findings with visual acuity in retinitis pigmentosa.

INTRODUCTION: Our purpose was to study the correlation between the macular morphology and function in eyes with retinitis pigmentosa (RP). METHODS: Sixty-six eyes from 33 patients with RP and with different visual acuity (VA) were studied using optical coherence tomography (OCT) and multifocal electroretinogram (mfERG). Correlation analysis was performed between VA, macular thickness, mfERG amplitude, and latency. RESULTS: Retinal thickness, retinal response density, and latency of the mfERG in the foveal area were independently and positively associated with VA (P = 0.002; P < 0.0001; P = 0.029; and P = 0.002, respectively), whereas there was no evidence for a correlation between VA and the amplitude of mfERG in the parafoveal area. Evidence of a correlation between the OCT and the mfERG evaluation was of borderline significance (P = 0.047). Also, there was evidence for an inverse association of VA with latency in ring 1 and ring 2 (b = -0.138; 95% confidence interval: -0.261, -0.015; P = 0.029). In accordance with the univariate findings, when foveal retinal thickness, mfERG amplitude, and latency in ring 1 were inserted simultaneously in the same model, all the three variables remained significantly associated with VA (P = 0.016; P < 0.0001; and P = 0.031, respectively). Nevertheless, some individual values deviated from the expected range. More specifically, 15 eyes showed a normal retinal thickness, whereas the respective VA was relatively low and the mfERG values were abnormal. Conversely, in seven eyes, despite the low retinal thickness, the respective VA was high. CONCLUSION: The combined use of OCT with mfERG appears to be more appropriate for the estimation of macular function.