The submarine hydrothermal activity on and near the Galápagos Rift has been explored with the aid of the deep submersible Alvin. Analyses of water samples from hydrothermal vents reveal that hydrothermal activity provides significant or dominant sources and sinks for several components of seawater; studies of conductive and convective heat transfer suggest that two-thirds of the heat lost from new oceanic lithosphere at the Galápagos Rift in the first million years may be vented from thermal springs, predominantly along the axial ridge within the rift valley. The vent areas are populated by animal communities. They appear to utilize chemosynthesis by sulfur-oxidizing bacteria to derive their entire energy supply from reactions between the seawater and the rocks at high temperatures, rather than photosynthesis.

Nocturnal asthma is a frequent problem, but the mechanism is unclear. We investigated the possibility that airways inflammation occurred during the night. Bronchoalveolar lavage fluid was analyzed in asthmatic patients with (n = 7) and without nocturnal asthma (n = 7) at 1600 and 0400 h. The nocturnal asthma group had an increase in the total leukocyte count (24.0 +/- 7.0 to 41.1 +/- 9.9 x 10(4) cells/ml, p less than 0.05), neutrophils (1.1 +/- 0.6 to 3.7 +/- 1.5 x 10(4) cells/ml, p less than 0.05), and eosinophils (0.5 +/- 0.1 to 1.7 +/- 0.7 x 10(4) cells/ml, p less than 0.05) from 1600 to 0400 h. Cellular components for the non-nocturnal asthma group did not change. Between groups, the 1600-h cells were similar. At 0400 h the nocturnal asthma group had significantly higher total leukocyte, neutrophil, eosinophil, lymphocyte, and epithelial cell counts. For all subjects, the overnight fall in peak expiratory flow rates was correlated to the change in neutrophils (r = 0.54, p less than 0.05) and eosinophils (r = 0.77, p less than 0.05). We conclude that the nocturnal worsening of asthma has an associated cellular inflammatory response that is not seen in patients without overnight decrements in lung function. This inflammatory response together with epithelial damage may be important factors in the etiology of nocturnal asthma.

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It has long been known that pillow basalts are a dominant feature of oceanic volca-

T supplementation was well tolerated and improved body composition but had no effect on functional performance. T supplementation improved upper body strength only in nonexercisers compared with placebo.

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This paper describes a vision-based, large-area, simultaneous localization and mapping (SLAM) algorithm that respects the low-overlap imagery constraints typical of underwater vehicles while exploiting the inertial sensor information that is routinely available on such platforms. We present a novel strategy for efficiently accessing and maintaining consistent covariance bounds within a SLAM information filter, thereby greatly increasing the reliability of data association. The technique is based upon solving a sparse system of linear equations coupled with the application of constant-time Kalman updates. The method is shown to produce consistent covariance estimates suitable for robot planning and data association. Real-world results are presented for a vision-based 6-DOF SLAM implementation using data from a recent ROV survey of the wreck of the RMS Titanic.

A significant number of patients with obstructive sleep apnea neither tolerate positive airway pressure (PAP) therapy nor achieve successful outcomes from either upper airway surgeries or use of an oral appliance. The purpose of this paper, therefore, was to systematically evaluate available peer-reviewed data on the effectiveness of adjunctive medical therapies and summarize findings from these studies. A review from 1985 to 2005 of the English literature reveals several practical findings. Weight loss has additional health benefits and should be routinely recommended to most overweight patients. Presently, there are no widely effective pharmacotherapies for individuals with sleep apnea, with the important exceptions of individuals with hypothyroidism or with acromegaly. Treating the underlying medical condition can have pronounced effects on the apnea/hypopnea index. Stimulant therapy leads to a small but statistically significant improvement in objective sleepiness. Nonetheless, residual sleepiness remains a significant health concern. Supplemental oxygen and positional therapy may benefit subsets of patients, but whether these therapies reduce morbidities as PAP therapy does will require rigorous randomized trials. PAP therapy has set the bar high for successful treatment of sleep apnea and its associated morbidities. Nonetheless, we should strive towards the development of universally effective pharmacotherapies for sleep apnea. To accomplish this, we require a greater knowledge of the neurochemical mechanisms underlying sleep apnea, and we must use this infrastructure of knowledge to design well-controlled, adequately powered studies that examine, not only effects on the apnea/hypopnea index, but also the effects of pharmacotherapies on all health related outcomes shown beneficial with PAP therapy.