Beetroot juice: effects on blood pressure, intraocular pressure, and ocular vessel density in healthy adults

Background: The blood pressure (BP)-lowering effect of beetroot is attributed to its high nitrate concentration, which converts to the vasodilator nitric oxide. Nitric oxide may also mediate ocular aqueous outflow to regulate intraocular pressure (IOP). Aims: We investigated the effect of beetroot juice on IOP and ocular vessel density. Subjects and Methods: With a single-blind, crossover design, 19 healthy young adults participated on 2 days 1 week apart. On Visit 1, baseline IOP, BP, and ocular vessel density (optical coherence tomography angiography, disc, and macula) were measured. Three hours after consumption of 16 ounces of beetroot juice or water (randomly assigned), all measurements were repeated. On Visit 2, baseline and 3-hour post-consumption measurements were assessed, with each subject consuming the drink not ingested on Visit 1. Results: Paired-samples t-test showed 1) no difference in IOP change post-water vs post-beet root juice (P = 0.27), and 2) mean systolic and diastolic BPs were lower only post-beet root juice (systolic: -4.8 (SEM ± 2.1) mm Hg, P = 0.032, 95% CI (0.47, 9.11); diastolic: -6.2 (SEM± 1.4) mm Hg, P <0.001, 95% CI (3.27, 9.15)). Superficial vessel density was significantly lower in several macular regions post-beet root juice, but not post-water (Wilcoxon signed ranks test, immediately superior, inferior, and temporal to center; respective P values of 0.016, 0.035, and 0.046). Conclusions: Beetroot juice lowers BP and macular vessel density, but does not lower IOP in young, healthy adults. Further investigation into its effect on IOP and vessel density in glaucomatous eyes is warranted. Keywords: beetroot, blood pressure, intraocular pressure, vessel density.

Assessment of Nitrate Removal Capacity of Two Selected Eukaryotic Green Microalgae

Eutrophication is a leading problem in water bodies all around the world in which nitrate is one of the major contributors. The present study was conducted to study the effects of various concentrations of nitrate on two eukaryotic green microalgae, Chlamydomonas sp. MACC-216 and Chlorella sp. MACC-360. For this purpose, both microalgae were grown in a modified tris-acetate-phosphate medium (TAP-M) with three different concentrations of sodium nitrate, i.e., 5 mM (TAP-M5), 10 mM (TAP-M10) and 15 mM (TAP-M15), for 6 days and it was observed that both microalgae were able to remove nitrate completely from the TAP-M5 medium. Total amount of pigments decreased with the increasing concentration of nitrate, whereas protein and carbohydrate contents remained unaffected. High nitrate concentration (15 mM) led to an increase in lipids in Chlamydomonas sp. MACC-216, but not in Chlorella sp. MACC-360. Furthermore, Chlamydomonas sp. MACC-216 and Chlorella sp. MACC-360 were cultivated for 6 days in synthetic wastewater (SWW) with varying concentrations of nitrate where both microalgae grew well and showed an adequate nitrate removal capacity.

Concurrent increases of PM2.5 and Ozone observed in Seoul, May 2019

&lt;p&gt;&amp;#160;In Seoul, PM&lt;sub&gt;2.5&lt;/sub&gt; concentrations were frequently elevated with O&lt;sub&gt;3&lt;/sub&gt; in May 2019. The most abundant constituent of PM&lt;sub&gt;2.5&lt;/sub&gt; was nitrate, which was the best correlated with OC (organic carbon) as well as NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;. An intensive experiment was conducted in the eastern part of Seoul from March 29 to June 19, 2019. Measurement was made for PM&lt;sub&gt;2.5 &lt;/sub&gt;and its chemical composition including NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2-&lt;/sup&gt;, NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+ &lt;/sup&gt;, OC, EC (elemental carbon), and reactive gases including O&lt;sub&gt;3&lt;/sub&gt;, NO, NO&lt;sub&gt;2&lt;/sub&gt;, CO, HONO, HNO&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, and SO&lt;sub&gt;2&lt;/sub&gt;, and meteorological variables including vertical winds and mixed layer height (MLH). The particle number concentration was measured using SMPS (Scanning Mobility Particle Sizer). All measurements were averaged for 1 hour according to the resolution of PM&lt;sub&gt;2.5&lt;/sub&gt; chemical composition. For the entire experiment, the mean mass concentrations of PM&lt;sub&gt;2.5&lt;/sub&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2-&lt;/sup&gt;, NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;, OC, and EC were 20.40 &amp;#956;g/m&lt;sup&gt;3&lt;/sup&gt;, 4.07 &amp;#956;g/m&lt;sup&gt;3&lt;/sup&gt;, 2.62 &amp;#956;g/m&lt;sup&gt;3&lt;/sup&gt;, 2.01 &amp;#956;g/m&lt;sup&gt;3&lt;/sup&gt;, 4.01 &amp;#956;g/m&lt;sup&gt;3&lt;/sup&gt;, and 1.04 &amp;#956;g/m&lt;sup&gt;3&lt;/sup&gt;, respectively. For reactive gases, the mean concentration was 1.03 ppbv for HONO, 0.70 ppbv for HNO&lt;sub&gt;3&lt;/sub&gt;, 14.87 ppbv for NH&lt;sub&gt;3&lt;/sub&gt;, 2.77 ppbv for SO&lt;sub&gt;2&lt;/sub&gt;, and 48.79 ppbv for O&lt;sub&gt;3&lt;/sub&gt;.&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;The maximum PM&lt;sub&gt;2.5&lt;/sub&gt; concentration of 72.81 &amp;#956;g/m&lt;sup&gt;3 &lt;/sup&gt;was observed under the influence of weak Asian dust event in the end of April. In May, there were three distinct episodes with highly enhanced PM&lt;sub&gt;2.5&lt;/sub&gt;. In the early May, the maximum nitrate concentration (36.11 &amp;#956;g/m&lt;sup&gt;3&lt;/sup&gt;) was observed with high HONO (2.41 ppbv) on 4 May. In the middle of May, PM&lt;sub&gt;2.5&lt;/sub&gt; was raised with SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2-&lt;/sup&gt; under stagnant condition. On 25 May, PM&lt;sub&gt;2.5&lt;/sub&gt; was raised up to 92 &amp;#956;g/m&lt;sup&gt;3 &lt;/sup&gt;with high nitrate concentration (18.56 &amp;#956;g/m&lt;sup&gt;3&lt;/sup&gt;) , when O&lt;sub&gt;3&lt;/sub&gt; reached 205 ppbv. In this episode, O&lt;sub&gt;3&lt;/sub&gt; concentration remained around 90 ppbv at night and OC and EC were well correlated with highly enhanced K&lt;sup&gt;+&lt;/sup&gt;. Thus, the concurrent enhancement of PM&lt;sub&gt;2.5&lt;/sub&gt; and O&lt;sub&gt;3&lt;/sub&gt; was likely due to the influence of aged biomass combustion plume laden air transported from southeast China. At the same time, HNO&lt;sub&gt;3&lt;/sub&gt; and HONO concentration was highly elevated, indicating that heterogeneous reactions played a role.&lt;/p&gt;

High-resolution physical–biogeochemical structure of a filament and an eddy of upwelled water off northwest Africa

Nutrient-rich water upwells offshore of northwest Africa and is subsequently advected westwards. There it forms eddies and filaments with a rich spatial structure of physical and biological/biogeochemical properties. Here we present a high-resolution (2.5 km) section through upwelling filaments and an eddy obtained in May 2018 with a TRIAXUS towed vehicle equipped with various oceanographic sensors. Physical processes at the mesoscale and submesoscale such as symmetric instability, trapping of fluid in eddies, and subduction of low potential vorticity (which we use as a water mass tracer) water can explain the observed distribution of biological production and export. We found a nitrate excess (higher concentrations of nitrate than expected from oxygen values if only influenced by production and remineralization processes) core of an anticyclonic mode water eddy. We also found a high nitrate concentration region of ≈5 km width in the mixed layer where symmetric instability appears to have injected nutrients from below into the euphotic zone. Similarly, further south high chlorophyll-a concentrations suggest that nutrients had been injected there a few days earlier. Considering that such interactions of physics and biology are ubiquitous in the upwelling regions of the world, we assume that they strongly influence the productivity of such systems and their role in CO2 uptake. The intricate interplay of different parameters at the kilometer scale needs to be taken into account when interpreting single-profile and/or bottle data in dynamically active regions of the ocean.

High-resolution physical-biogeochemical structure of a filament and an eddy of upwelled water off Northwest Africa

Nutrient rich water upwells offshore of Northwest Africa and is subsequently advected westwards. There it forms eddies and filaments with a rich spatial structure of physical and biological/biogeochemical properties. Here we present a high resolution (2.5 km) section through upwelling filaments and an eddy obtained in May 2018 with a Triaxus towed vehicle equipped with various oceanographic sensors. Physical processes at the mesoscale and submesoscale such as symmetric instability, trapping of fluid in eddies, and subduction of low potential vorticity (which we use as a water mass tracer) water can explain the observed distribution of biological production and export. We found a nitrate excess (higher nitrate concentrations than would be expected from oxygen values if only influenced by production and remineralization processes) core of an anti-cyclonic mode water eddy. We also found a high nitrate concentration region of ~5 km width in the mixed layer where symmetric instability appears to have injected nutrients from below into the euphotic zone. A similar region a little further south had high chlorophyll-a concentrations suggesting that nutrients had been injected there a few days earlier. Considering that such interactions of physics and biology are ubiquitous in the world's upwelling regions, we assume that they have strong influences on the productivity of such systems and their role in CO2 uptake. The intricate interplay of different parameters at kilometer scale needs to be taken into account when interpreting single profile and/or bottle data in dynamically active regions of the ocean.

Modelling nitrate concentration of groundwater using adaptive neural-based fuzzy inference system

High nitrate concentration in groundwater is a major problem in agricultural areas in Iran. Nitrate pollution in groundwater of the particular regions in Isfahan province of Iran has been investigated. The objective of this study was to evaluate the performance of Adaptive Neural-Based Fuzzy Inference System (ANFIS) for estimating the nitrate concentration. In this research, 175 observation wells were selected and nitrate, potassium, magnesium, sodium, chloride, bicarbonate, sulphate, calcium and hardness were determined in groundwater samples for five consecutive months. Electrical conductivity (EC) and pH were also measured and the sodium absorption ratio (SAR) was calculated. The five-month average of bicarbonate, hardness, EC, calcium and magnesium are taken as the input data and the nitrate concentration as the output data. Based on the obtained structures, four ANFIS models were tested against the measured nitrate concentrations to assess the accuracy of each model. The results showed that ANFIS1 was the most accurate (RMSE = 1.17 and R² = 0.93) and ANFIS4 was the worst (RMSE = 2.94 and R² = 0.68) for estimating the nitrate concentration. In ranking the models, ANFIS2 and ANFIS3 ranked the second and third, respectively. The results showed that all ANFIS models underestimated the nitrate concentration. In general, the ANFIS1 model is recommendable for prediction of nitrate level in groundwater of the studied region.

Remote-Sensing-Based Estimation of Surface Nitrate and Its Variability in the Southern Peninsular Indian Waters

A relationship between sea surface temperature (SST) and surface nitrate concentrations has been obtained for the first time based on in situ datasets retrieved from U.S. JGOFS (1991–96) and Indian cruises (2000–2006) in the Arabian Sea, Bay of Bengal and Indian Ocean region around the southern Indian tip. The dataset includes 1537 points. A sigmoid relationship obtained with value 0.912. NOAA-AVHRR pathfinder satellite monthly averaged SST data retrieved from the PODAAC/JPL/NASA archive during July 1999–June 2004. The datasets imported in the ERDAS-Imagine software and SST images generated on monthly and seasonal scales, for latitudes 5–12°N and longitudes 75–85°E. The ocean surface nitrate images retrieved based on the established sigmoid relationship with SST. The nitrate concentrations ranged between 0.01–3.0 μM and categorized into five ranges. The significant seasonal upwelling zone around the southwest coast of India (Kerala coast, Latitude 80.10–9.30°N and Longitude 75.60–76.20°E) was identified during July–September 1999–2004 with very high nitrate concentration (~1.00 μM). Low nitrate and nitrate-depleted zones observed during summer (March–May). In the Arabian Sea and northern Indian Ocean, high nitrate concentration (~0.50 μM) observed during the southwest monsoon (SWM), whereas the Bay of Bengal was marked with high nitrate (~0.50 μM) during the northeast monsoon (NEM). SST was high (~29°C) in the Bay of Bengal and low (~26°C) in the Arabian Sea and northern Indian Ocean during SWM and vice versa during the NEM. There is a clear inverse relationship between nitrate and SST in the study area during July 1999–June 2004.