Radar for Europa Assessment and Sounding: Ocean to Near-Surface (REASON).

The Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) is a dual-frequency ice-penetrating radar (9 and 60 MHz) onboard the Europa Clipper mission. REASON is designed to probe Europa from exosphere to subsurface ocean, contributing the third dimension to observations of this enigmatic world. The hypotheses REASON will test are that (1) the ice shell of Europa hosts liquid water, (2) the ice shell overlies an ocean and is subject to tidal flexing, and (3) the exosphere, near-surface, ice shell, and ocean participate in material exchange essential to the habitability of this moon. REASON will investigate processes governing this material exchange by characterizing the distribution of putative non-ice material (e.g., brines, salts) in the subsurface, searching for an ice-ocean interface, characterizing the ice shell's global structure, and constraining the amplitude of Europa's radial tidal deformations. REASON will accomplish these science objectives using a combination of radar measurement techniques including altimetry, reflectometry, sounding, interferometry, plasma characterization, and ranging. Building on a rich heritage from Earth, the moon, and Mars, REASON will be the first ice-penetrating radar to explore the outer solar system. Because these radars are untested for the icy worlds in the outer solar system, a novel approach to measurement quality assessment was developed to represent uncertainties in key properties of Europa that affect REASON performance and ensure robustness across a range of plausible parameters suggested for the icy moon. REASON will shed light on a never-before-seen dimension of Europa and - in concert with other instruments on Europa Clipper - help to investigate whether Europa is a habitable world.

Clinical overview of algal-docosahexaenoic acid: effects on triglyceride levels and other cardiovascular risk factors.

The cardiovascular benefits of fish-derived long-chain polyunsaturated fatty acids, docosahexaenoic acid (DHA), and eicosapentaenoic acid are well established. Less studied are specific effects of individual long-chain polyunsaturated fatty acids. Based on data from 16 published clinical trials, this review examines effects of DHA triglyceride (TG) oil derived from algae (algal-DHA) on serum TG levels and related parameters. Study populations included subjects with both normal and elevated TG levels including those with persistent hypertriglyceridemia treated with concomitant 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) therapy. At doses of 1-2 g/d, algal-DHA significantly lowered plasma TG levels (up to 26%) either administered alone or in combination with statins. The reduction in TG levels was markedly greater in hypertriglyceridemic than in normal subjects. Algal-DHA modestly increased plasma levels of both high-density lipoprotein and low-density lipoprotein cholesterol. The increased plasma level of low-density lipoprotein cholesterol was associated with a shift of lipoprotein particle size toward larger, less atherogenic subfractions. In some subjects, blood pressure and heart rate were significantly reduced. Algal-DHA was safe and well tolerated. Unlike fish oil, algal-DHA seldom caused gastrointestinal complaints such as fishy taste and eructation, attributes of importance for patient compliance in high-dose therapy. Regression analysis that showed a linear relationship between baseline TG and magnitude of TG reduction suggests that a study of patients with very high TG levels (>500 mg/dL) is warranted. Future pharmacologic therapies for treating hypertriglyceridemia may include algal-DHA.

Algal-oil capsules and cooked salmon: nutritionally equivalent sources of docosahexaenoic acid.

Food and nutrition professionals question whether supplement-sourced nutrients appear to be equivalent to those derived from natural food sources. We compared the nutritional availability of docosahexaenoic acid (DHA) from algal-oil capsules to that from assayed cooked salmon in 32 healthy men and women, ages 20 to 65 years, in a randomized, open-label, parallel-group study. In this 2-week study comparing 600 mg DHA/day from algal-oil capsules to that from assayed portions of cooked salmon, mean change from baseline in plasma phospholipids and erythrocyte DHA levels was analyzed and DHA levels were compared by Student's t tests. In post-hoc analyses to determine bioequivalence, least-squares mean ratios of percent change from baseline in plasma phospholipid and erythrocyte DHA levels were compared. DHA levels increased by approximately 80% in plasma phospholipids and by approximately 25% in erythrocytes in both groups. Changes in DHA levels in plasma phospholipids and erythrocytes were similar between groups. As measured by delivery of DHA to both plasma and erythrocytes, fish and algal-oil capsules were equivalent. Both regimens were generally well-tolerated. These results indicate that algal-oil DHA capsules and cooked salmon appear to be bioequivalent in providing DHA to plasma and red blood cells and, accordingly, that algal-oil DHA capsules represent a safe and convenient source of non-fish-derived DHA.

Bioequivalence of Docosahexaenoic acid from different algal oils in capsules and in a DHA-fortified food.

Docosahexaenoic acid (DHA), a long-chain omega-3 fatty acid, is important for eye and brain development and ongoing visual, cognitive, and cardiovascular health. Unlike fish-sourced oils, the bioavailability of DHA from vegetarian-sourced (algal) oils has not been formally assessed. We assessed bioequivalence of DHA oils in capsules from two different algal strains versus bioavailability from an algal-DHA-fortified food. Our 28-day randomized, placebo-controlled, parallel group study compared bioavailability of (a) two different algal DHA oils in capsules ("DHASCO-T" and "DHASCO-S") at doses of 200, 600, and 1,000 mg DHA per day (n = 12 per group) and of (b) an algal-DHA-fortified food (n = 12). Bioequivalence was based on changes in plasma phospholipid and erythrocyte DHA levels. Effects on arachidonic acid (ARA), docosapentaenoic acid-n-6 (DPAn-6), and eicosapentaenoic acid (EPA) were also determined. Both DHASCO-T and DHASCO-S capsules produced equivalent DHA levels in plasma phospholipids and erythrocytes. DHA response was dose-dependent and linear over the dose range, plasma phospholipid DHA increased by 1.17, 2.28 and 3.03 g per 100 g fatty acid at 200, 600, and 1,000 mg dose, respectively. Snack bars fortified with DHASCO-S oil also delivered equivalent amounts of DHA on a DHA dose basis. Adverse event monitoring revealed an excellent safety and tolerability profile. Two different algal oil capsule supplements and an algal oil-fortified food represent bioequivalent and safe sources of DHA.