Search results for "Diving"

The operational sex ratio of the sea urchin Paracentrotus lividus populations: the case of the Mediterranean marine protected area of Ustica Island (…

2009

We investigated, with a series of field and laboratory observations, the possible effect of the starfish Marthasteria glacialis predation on the operational sex ratio (OSR), i.e. the number of sexually mature males divided by the total number of sexually mature adults of both sexes at any one time, of the edible sea urchin Paracentrotus lividus. The OSR was estimated three times during the sea urchin summer spawning period (July 2004, June 2005 and July 2006) on barren substrates of Ustica Island Marine Protected Area (Southern Tyrrhenian Sea, Italy). Four sites were selected: two characterized by high M. glacialis density (take zone C) and two controls with low starfish density (no-take zo…

Subsurface swimming and stationary diving are metabolically cheap in adult Pacific walruses (Odobenus rosmarus divergens).

2021

ABSTRACT Walruses rely on sea-ice to efficiently forage and rest between diving bouts while maintaining proximity to prime foraging habitat. Recent declines in summer sea ice have resulted in walruses hauling out on land where they have to travel farther to access productive benthic habitat while potentially increasing energetic costs. Despite the need to better understand the impact of sea ice loss on energy expenditure, knowledge about metabolic demands of specific behaviours in walruses is scarce. In the present study, 3 adult female Pacific walruses (Odobenus rosmarus divergens) housed in professional care participated in flow-through respirometry trials to measure metabolic rates while…

Neurocognitive Markers During Prolonged Breath-Holding in Freedivers: An Event-Related EEG Study

2019

Since little is known concerning the psychological, cognitive, and neurophysiological factors that are involved in and important for phases of prolonged breath-holding (pBH) in freedivers, the present study uses electroencephalography (EEG) to investigate event-related neurocognitive markers during pBH of experienced freedivers that regularly train pBH. The purpose was to determine whether the well-known neurophysiological modulations elicited by hypoxic and hypercapnic conditions can also be detected during pBH induced hypoxic hypercapnia. Ten experienced free-divers (all male, aged 35.10 ± 7.89 years) were asked to hold their breath twice for 4 min per instance. During the first pBH, a ch…

Exploring motivational states in an international sample of competitive springboard and platform divers

2009

Tubal function in divers and non-divers: case control study

2009

Background. The aim of this study was to examine whether recurrent scuba diving during the time and frequent use of Valsalva’s manoeuvre while diving, increase functionality of divers’ Eustachian Tube (ET) comparison with non-divers. Methods. The study included 30 experienced divers (G1), mean age 25,8 years, who were diving from over 10 years. The control group consisted of 30 non-divers (G2), mean age 31,3 years. Each sample underwent clinical examination to identify predisposing conditions to middle ear barotraumas and ET dysfunction. ET function has been investigated by Inflation-Deflation test that shows baseline tympanogram, a second tympanogram shifted of the peak towards positive va…