Shifts in coralline algae, macroalgae, and coral juveniles in the Great Barrier Reef associated with present-day ocean acidification.

Seawater acidification from increasing CO2 is often enhanced in coastal waters due to elevated nutrients and sedimentation. Our understanding of the effects of ocean and coastal acidification on present-day ecosystems is limited. Here we use data from three independent large-scale reef monitoring programs to assess coral reef responses associated with changes in mean aragonite saturation state (Ωar ) in the Great Barrier Reef World Heritage Area (GBR). Spatial declines in mean Ωar are associated with monotonic declines in crustose coralline algae (up to 3.1-fold) and coral juvenile densities (1.3-fold), while non-calcifying macroalgae greatly increase (up to 3.2-fold), additionally to their natural changes across and along the GBR. These three key groups of organisms are important proxies for coral reef health. Our data suggest a tipping point at Ωar 3.5-3.6 for these coral reef health indicators. Suspended sediments acted as an additive stressor. The latter suggests that effective water quality management to reduce suspended sediments might locally and temporarily reduce the pressure from ocean acidification on these organisms.

Managing a Destructive, Episodic Crop Disease: A National Survey of Wheat and Barley Growers' Experience With Fusarium Head Blight.

The main techniques for minimizing Fusarium head blight (FHB, or scab) and deoxynivalenol in wheat and barley are well established and generally available: planting of moderately FHB-resistant cultivars, risk monitoring, and timely use of the most effective fungicides. Yet the adoption of these techniques remains uneven across the FHB-prone portions of the U.S. cereal production area. A national survey was undertaken by the U.S. Wheat and Barley Scab Initiative in 17 states where six market classes of wheat and barley are grown. In 2014, 5,107 usable responses were obtained. The highest percentages reporting losses attributable to FHB in the previous 5 years were in North Dakota, Maryland, Kentucky, and states bordering the Great Lakes but across all states, ≥75% of respondents reported no FHB-related losses in the previous 5 years. Adoption of cultivar resistance was uneven by state and market class and was low except among hard red spring wheat growers. In 13 states, a majority of respondents had not applied an FHB-targeted fungicide in the previous 5 years. Although the primary FHB information source varied by state, crop consultants were considered to be an important source or their primary source of information on risk or management of FHB by the largest percentage of respondents. Use of an FHB risk forecasting website was about twice as high in North Dakota as the 17-state average of 6%. The most frequently cited barriers to adopting FHB management practices were weather or logistics preventing timely fungicide application, difficulty in determining flowering timing for fungicide applications, and the impracticality of FHB-reducing rotations. The results highlight the challenges of managing an episodically damaging crop disease and point to specific areas for improvement.

Subsurface temperature estimates from a Regional Ocean Modelling System (ROMS) reanalysis provide accurate coral heat stress indices across the Main Hawaiian Islands.

As ocean temperatures continue to rise, coral bleaching events around the globe are becoming stronger and more frequent. High-resolution temperature data is therefore critical for monitoring reef conditions to identify indicators of heat stress. Satellite and in situ measurements have historically been relied upon to study the thermal tolerances of coral reefs, but these data are quite limited in their spatial and temporal coverage. Ocean circulation models could provide an alternative or complement to these limited data, but a thorough evaluation against in situ measurements has yet to be conducted in any Pacific Islands region. Here we compared subsurface temperature measurements around the nearshore Main Hawaiian Islands (MHI) from 2010 to 2017 with temperature predictions from an operational Regional Ocean Modeling System (ROMS) to evaluate the potential utility of this model as a tool for coral reef management. We found that overall, the ROMS reanalysis presents accurate subsurface temperature predictions across the nearshore MHI region and captures a significant amount of observed temperature variability. The model recreates several temperature metrics used to identify coral heat stress, including predicting the 2014 and 2015 bleaching events around Hawai'i during the summer and fall months of those years. The MHI ROMS simulation proves to be a useful tool for coral reef management in the absence of, or to supplement, subsurface and satellite measurements across Hawai'i and likely for other Pacific Island regions.

Material properties of euphausiids and other zooplankton from the Bering Sea.

Acoustic assessment of Bering Sea euphausiids and their predators can provide useful data for ecosystem studies if the acoustic scattering characteristics of these animals are known. The amount of acoustic energy that is scattered by different marine zooplankton taxa is strongly affected by the contrast of the animal's density (g) and sound speed (h) with the surrounding seawater. Density and sound speed contrast were measured in the Bering Sea during the summer of 2008 for several different zooplankton and nekton taxa including: euphausiids (Thysanoessa inermis, Thysanoessa raschii, and Thysanoessa spinifera), copepods, amphipods, chaetognaths, gastropods, fish larvae, jellyfish, and squid. Density contrast values varied between different taxa as well as between individual animals within the same species. Sound speed contrast was measured for monospecific groups of animals and differences were found among taxa. The range, mean, and standard deviation of g and h for all euphausiid species were: g = 1.001-1.041; 1.018 ± 0.009 and h = 0.990-1.017; 1.006 ± 0.008. Changes in the relationship between euphausiid material properties and animal length, seawater temperature, seawater density, and geographic location were also evaluated. Results suggest that environmental conditions at different sample locations led to significant differences in animal density and material properties.

Progressive seawater acidification on the Great Barrier Reef continental shelf.

Coral reefs are highly sensitive to ocean acidification due to rising atmospheric CO2 concentrations. We present 10 years of data (2009-2019) on the long-term trends and sources of variation in the carbon chemistry from two fixed stations in the Australian Great Barrier Reef. Data from the subtropical mid-shelf GBRWIS comprised 3-h instrument records, and those from the tropical coastal NRSYON were monthly seawater samples. Both stations recorded significant variation in seawater CO2 fugacity (fCO2), attributable to seasonal, daytime, temperature and salinity fluctuations. Superimposed over this variation, fCO2 progressively increased by > 2.0 ± 0.3 µatm year-1 at both stations. Seawater temperature and salinity also increased throughout the decade, whereas seawater pH and the saturation state of aragonite declined. The decadal upward fCO2 trend remained significant in temperature- and salinity-normalised data. Indeed, annual fCO2 minima are now higher than estimated fCO2 maxima in the early 1960s, with mean fCO2 now ~ 28% higher than 60 years ago. Our data indicate that carbonate dissolution from the seafloor is currently unable to buffer the Great Barrier Reef against ocean acidification. This is of great concern for the thousands of coral reefs and other diverse marine ecosystems located in this vast continental shelf system.

ß-catenin promotes endothelial survival by regulating eNOS activity and flow-dependent anti-apoptotic gene expression.

Increased endothelial cell (EC) apoptosis is associated with the development of atherosclerotic plaques that develop predominantly at sites exposed to disturbed flow (DF). Strategies to promote EC survival may therefore represent a novel therapeutic approach in cardiovascular disease. Nitric oxide (NO) and ß-catenin have both been shown to promote cell survival and they interact in ECs as we previously demonstrated. Here we investigated the physiological role of ß-catenin as a mediator of NO-induced cell survival in ECs. We found that ß-catenin depleted human umbilical vein ECs (HUVEC) stimulated with pharmacological activators of endothelial NO synthase (eNOS) showed a reduction in eNOS phosphorylation (Ser1177) as well as reduced intracellular cyclic guanosine monophosphate levels compared to control cells in static cultures. In addition, ß-catenin depletion abrogated the protective effects of the NO donor, S-nitroso-N-acetylpenicillamine, during TNFα- and H2O2-induced apoptosis. Using an orbital shaker to generate shear stress, we confirmed eNOS and ß-catenin interaction in HUVEC exposed to undisturbed flow and DF and showed that ß-catenin depletion reduced eNOS phosphorylation. ß-catenin depletion promoted apoptosis exclusively in HUVEC exposed to DF as did inhibition of soluble guanylate cyclase (sGC) or ß-catenin transcriptional activity. The expression of the pro-survival genes, Bcl-2 and survivin was also reduced following inhibition of ß-catenin transcriptional activity, as was the expression of eNOS. In conclusion, our data demonstrate that ß-catenin is a positive regulator of eNOS activity and cell survival in human ECs. sGC activity and ß-catenin-dependent transcription of Bcl-2, survivin, BIRC3 and eNOS are essential to maintain cell survival in ECs under DF.

Density and sound speed of two gelatinous zooplankton: ctenophore (Mnemiopsis leidyi) and lion's mane jellyfish (Cyanea capillata).

The density and sound speed of two coastal, gelatinous zooplankton, Mnemiopsis leidyi (a ctenophore) and Cyanea capillata (lion's mane jellyfish), were measured. These parameters are important inputs to acoustic scattering models. Two different methods were used to measure the density of individual animals: one used a balance and graduated cylinder to determine the mass and displacement volume of the animal, the other varied the density of the solution the animal was immersed in. When the same animal was measured using both methods, density values were within 1% of each other. A travel-time difference method was used to measure the sound speed within the animals. The densities of both zooplankton slightly decreased as the animals increased in length, mass, and volume. The ratio of animal density and sound speed to the surrounding seawater (g and h, respectively) are reported for both animals. For Mnemiopsis leidyi ranging in length from 1 to 5 cm, the mean value (+/-standard deviation) of g and h were 1.009 (+/-0.004) and 1.007 (+/-0.001). For Cyanea capillata ranging in bell diameter from 2 to 11 cm, the mean value (+/-standard deviation) of g and single value of h were 1.009 (+/-0.004) and 1.0004.

Pontellid copepods, Labidocera spp., affected by ocean acidification: A field study at natural CO2 seeps.

CO2 seeps in coral reefs were used as natural laboratories to study the impacts of ocean acidification on the pontellid copepod, Labidocera spp. Pontellid abundances were reduced by ∼70% under high-CO2 conditions. Biological parameters and substratum preferences of the copepods were explored to determine the underlying causes of such reduced abundances. Stage- and sex-specific copepod lengths, feeding ability, and egg development were unaffected by ocean acidification, thus changes in these physiological parameters were not the driving factor for reduced abundances under high-CO2 exposure. Labidocera spp. are demersal copepods, hence they live amongst reef substrata during the day and emerge into the water column at night. Deployments of emergence traps showed that their preferred reef substrata at control sites were coral rubble, macro algae, and turf algae. However, under high-CO2 conditions they no longer had an association with any specific substrata. Results from this study indicate that even though the biology of a copepod might be unaffected by high-CO2, Labidocera spp. are highly vulnerable to ocean acidification.

The binding of the bone morphogenetic protein antagonist gremlin to kidney heparan sulfate: Such binding is not essential for BMP antagonism.

Gremlin-1, a bone morphogenetic protein (BMP) antagonist, has essential roles in kidney and limb bone development, and is important in chronic diseases including tissue fibrosis. It also functions as an activating ligand of the vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2), and binds strongly to the sulfated polysaccharide, heparin. Here we investigated the extent to which gremlin binds to the related polysaccharide heparan sulfate (HS), which unlike heparin is widely distributed spread within tissues. We determined that both highly sulfated HS and kidney HS are able to partially compete for the binding of heparin to gremlin, whereas low sulfated HS is a poor competitor. In further investigations of the interaction between gremlin and HS, we found that wild-type gremlin is able to bind broadly across the various regions of kidney in an HS-dependent manner, with particularly intense binding to tubular structures in the renal cortex. In a model of chronic kidney disease, fibrotic changes in the kidney result in a loss of gremlin binding sites. Gremlin mutants with reduced affinity for heparin showed negligible binding under the same conditions. These mutants nonetheless remain functional as BMP antagonists on C2C12 myoblastic cells transfected with a Smad 1 reporter gene construct. Overall our findings indicate that on secretion, gremlin will bind to HS structures on the cell surface and in the extracellular matrix, thus providing for a localised reservoir which can modulate BMP activity in a temporospatially restricted manner. Although binding of heparin/HS to gremlin has been shown elsewhere to be necessary for gremlin activation of VEGFR2, this does not appear to be essential for BMP antagonism by gremlin. Thus these sulfated polysaccharides differentially regulate the activities of gremlin.

Implementation of Web-Based Autism Screening in an Urban Clinic.

Screening toddlers for autism spectrum disorder (ASD) with the Modified Checklist for Autism in Toddlers, Revised (M-CHAT-R) has been shown to lower age of diagnosis by 2 years. In order to streamline ASD screening, research is exploring the use of web-based screening during well-child checkups. The current study examined implementation of the web-based M-CHAT-R in an urban pediatric clinic in Atlanta, Georgia. Toddlers (N = 2557; 87% African American) were screened during well-child visits (Mage = 22.43 months, SD = 3.65). Using the web-based version resulted in a 58.5% increase in the number of cases screened per month. A similar proportion of toddlers in each modality screened positive (P = .43), but significantly fewer children were missing "Follow-up" in the web-based administration (P < .001). These results suggest that it is feasible to implement web-based screening in underserved populations. Future research is necessary to understand factors that facilitate successful implementation of web-based ASD screening.

Reduced heterotrophy in the stony coral Galaxea fascicularis after life-long exposure to elevated carbon dioxide.

Ocean acidification imposes many physiological, energetic, structural and ecological challenges to stony corals. While some corals may increase autotrophy under ocean acidification, another potential mechanism to alleviate some of the adverse effects on their physiology is to increase heterotrophy. We compared the feeding rates of Galaxea fascicularis colonies that have lived their entire lives under ocean acidification conditions at natural carbon dioxide (CO2) seeps with colonies living under present-day CO2 conditions. When provided with the same quantity and composition of zooplankton as food, corals acclimatized to high CO2 showed 2.8 to 4.8 times depressed rates of zooplankton feeding. Results were consistent over four experiments, from two expeditions and both in field and chamber measurements. Unless replenished by other sources, reduced zooplankton uptake in G. fascicularis acclimatized to ocean acidification is likely to entail a shortage of vital nutrients, potentially jeopardizing their health and survival in future oceans.

25-hydroxyvitamin D status of healthy, low-income, minority children in Atlanta, Georgia.

OBJECTIVES: The goals were to determine the prevalence of vitamin D deficiency among minority children in a southern US city, to examine differences in serum 25-hydroxyvitamin D levels between non-Hispanic black and Hispanic children, and to determine dietary sources of vitamin D. METHODS: Low-income, minority children (N = 290; mean age: 2.5 +/- 1.2 years) were recruited during well-child clinic visits. Serum 25-hydroxyvitamin D and calcium levels were measured and dietary information was assessed. RESULTS: The mean 25-hydroxyvitamin D(3) level was 26.2 +/- 7.6 ng/mL, whereas 25-hydroxyvitamin D(2) was not detected. Overall, 22.3% of children had deficient serum 25-hydroxyvitamin D(3) levels (< or =20 ng/mL), 73.6% had less-than-optimal serum 25-hydroxyvitamin D levels (< or =30 ng/mL), and 1.4% had low serum calcium levels (< or =9 mg/dL). A significantly larger proportion of non-Hispanic black children, compared with Hispanic children, had vitamin D deficiency (26% vs 18%; P < .05). Age and season of recruitment were significantly associated with vitamin D deficiency and low serum calcium levels. Older children (> or =3 years) were less likely to have vitamin D deficiency (odds ratio [OR]: 0.89 [95% confidence interval [CI]: 0.81-0.96]; P < .001). Study enrollment during spring and summer reduced the likelihood of vitamin D deficiency by approximately 20% (spring, OR: 0.85 [95% CI: 0.73-0.98]; P = .03; summer, OR: 0.82 [95% CI: 0.73-0.92]; P < .01). Fortified milk provided most dietary vitamin D (62%), with Hispanic children reporting greater intake. CONCLUSIONS: Suboptimal vitamin D status was common among apparently healthy, low-income, minority children. Age and season were significant predictors of vitamin D deficiency.

Zinc and iron deficiency and their interrelations in low-income African American and Hispanic children in Atlanta.

BACKGROUND: Information about the zinc status of low-income minority children in the United States is lacking. OBJECTIVE: The objective was to determine the prevalence of zinc deficiency and anemia and their interrelation among low-income African American and Hispanic preschool children. DESIGN: This was a cross-sectional study in which a prospective 3-d food diary was completed, and hemoglobin, serum ferritin, zinc, copper, and C-reactive protein concentrations were measured. Children with elevated C-reactive protein concentrations were excluded from analysis. RESULTS: Of 292 children recruited, 280 (mean +/- SD age: 2.5 +/- 1.2 y) qualified for analysis. One hundred forty-six (52%) children were African American and 134 (48%) were Hispanic; 202 (72%) were enrolled in the Women, Infants, and Children nutrition program. A low serum zinc concentration (<10.7 mumol/L) was present in 34 (12%) children, and 37 (13%) were anemic (hemoglobin < 110 g/L). African American (odds ratio: 3.47; 95% CI: 1.51, 7.96) and anemic (odds ratio: 2.92; 95% CI: 1.24, 6.90) children had an increased risk of zinc deficiency. Serum zinc correlated with hemoglobin (r = 0.24, P < 0.001). Children with a height/length less than the fifth percentile had significantly lower mean serum zinc concentrations than those with a height/length greater than the fifth percentile (12.4 +/- 1.8 compared with 13.0 +/- 2.2 micromol/L; P < 0.001). In a multiple logistic regression model, African American race-ethnicity was associated with zinc deficiency (odds ratio: 0.26; P = 0.02). The main sources of iron and zinc in the diets were meat products and cereals. CONCLUSIONS: The prevalence of zinc deficiency and anemia was high in this population of low-income minority children, especially among African Americans. Further investigation of the incidence of zinc deficiency and the ability of anemia to screen for it is warranted.