Phylogenetic Relationships of Foliar Bacteria Within Cover Crops in an Organic Cropping System.

As the human population continues to grow, there is an increasing realization that there is a finite amount of land available to grow enough food to feed people in the long-term. Sustainable agriculture is one key part of the solution to this issue. One technique used in sustainable agriculture is cover cropping, which involves the planting of a non-cash crop that is used to restore nutrients or structure within the soil. Although these benefits of cover cropping are well documented, the effect that this practice has on the reduction of pathogens on cash crops has yet to be fully explored. Even though endophytes (asymptomatic microbes living inside of plant tissues) live cryptically within their plant host, they have also been noted to help reduce the disease symptoms of their plant host. If the relationship between endophytes and pathogens could be better understood, these interactions could be used to aid in pathogen reduction. Our objective is thus to quantify which bacterial taxa inhabit the leaves of cover crops (purple vetch, Vicia americana; daikon radish, Raphanus sativus var. longipinnatus; and fava beans, Vicia faba) in an organic agricultural setting. In coordination with a working farm in Marin County, California (Star Route Farms), we sampled cover crop leaves prior to the start of the cash crop growing season. Leaves were surface sterilized with dilute bleach and ethanol and leaf fragments were placed into slant tubes with malt extract agar to isolate emergent foliar bacteria. Microbial slant tube growth was quantified, and bacterial isolates were identified using 16S Sanger sequencing and BLAST queries of the NCBI Genbank database. The results from this research could provide a new technique for improving agricultural sustainability and could also contribute towards a better ecological understanding of these complex and economically critical agricultural systems

Investigating Alaskan Methane and Carbon Dioxide Fluxes Using Measurements from the CARVE Tower

Northern high-latitude carbon sources and sinks, including those resulting from degrading permafrost, are thought to be sensitive to the rapidly warming climate. Because the near-surface atmosphere integrates surface fluxes over large ( ∼ 500–1000 km) scales, atmospheric monitoring of carbon dioxide (CO2) and methane (CH4) mole fractions in the daytime mixed layer is a promising method for detecting change in the carbon cycle throughout boreal Alaska. Here we use CO2 and CH4 measurements from a NOAA tower 17 km north of Fairbanks, AK, established as part of NASA\u27s Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE), to investigate regional fluxes of CO2 and CH4 for 2012–2014. CARVE was designed to use aircraft and surface observations to better understand and quantify the sensitivity of Alaskan carbon fluxes to climate variability. We use high-resolution meteorological fields from the Polar Weather Research and Forecasting (WRF) model coupled with the Stochastic Time-Inverted Lagrangian Transport model (hereafter, WRF-STILT), along with the Polar Vegetation Photosynthesis and Respiration Model (PolarVPRM), to investigate fluxes of CO2 in boreal Alaska using the tower observations, which are sensitive to large areas of central Alaska. We show that simulated PolarVPRM–WRF-STILT CO2 mole fractions show remarkably good agreement with tower observations, suggesting that the WRF-STILT model represents the meteorology of the region quite well, and that the PolarVPRM flux magnitudes and spatial distribution are generally consistent with CO2 mole fractions observed at the CARVE tower. One exception to this good agreement is that during the fall of all 3 years, PolarVPRM cannot reproduce the observed CO2 respiration. Using the WRF-STILT model, we find that average CH4 fluxes in boreal Alaska are somewhat lower than flux estimates by Chang et al. (2014) over all of Alaska for May–September 2012; we also find that enhancements appear to persist during some wintertime periods, augmenting those observed during the summer and fall. The possibility of significant fall and winter CO2 and CH4 fluxes underscores the need for year-round in situ observations to quantify changes in boreal Alaskan annual carbon balance

Modeling surf zone tracer plumes : 1. Waves, mean currents, and low-frequency eddies

Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): C11027, doi:10.1029/2011JC007210.A model that accurately simulates surf zone waves, mean currents, and low-frequency eddies is required to diagnose the mechanisms of surf zone tracer transport and dispersion. In this paper, a wave-resolving time-dependent Boussinesq model is compared with waves and currents observed during five surf zone dye release experiments. In a companion paper, Clark et al. (2011) compare a coupled tracer model to the dye plume observations. The Boussinesq model uses observed bathymetry and incident random, directionally spread waves. For all five releases, the model generally reproduces the observed cross-shore evolution of significant wave height, mean wave angle, bulk directional spread, mean alongshore current, and the frequency-dependent sea surface elevation spectra and directional moments. The largest errors are near the shoreline where the bathymetry is most uncertain. The model also reproduces the observed cross-shore structure of rotational velocities in the infragravity (0.004 < f < 0.03 Hz) and very low frequency (VLF) (0.001 < f < 0.004 Hz) bands, although the modeled VLF energy is 2–3 times too large. Similar to the observations, the dominant contributions to the modeled eddy-induced momentum flux are in the VLF band. These eddies are elliptical near the shoreline and circular in the mid surf zone. The model-data agreement for sea swell waves, low-frequency eddies, and mean currents suggests that the model is appropriate for simulating surf zone tracer transport and dispersion.This research was supported by SCCOOS, CA Coastal Conservancy, NOAA, NSF, ONR, and CA Sea Grant.2012-05-1

An update to the Surface Ocean CO₂ Atlas (SOCAT version 2)

The Surface Ocean CO₂ Atlas (SOCAT), an activity of the international marine carbon research community, provides access to synthesis and gridded fCO₂ (fugacity of carbon dioxide) products for the surface oceans. Version 2 of SOCAT is an update of the previous release (version 1) with more data (increased from 6.3 million to 10.1 million surface water fCO₂ values) and extended data coverage (from 1968–2007 to 1968–2011). The quality control criteria, while identical in both versions, have been applied more strictly in version 2 than in version 1. The SOCAT website (http://www.socat.info/) has links to quality control comments, metadata, individual data set files, and synthesis and gridded data products. Interactive online tools allow visitors to explore the richness of the data. Applications of SOCAT include process studies, quantification of the ocean carbon sink and its spatial, seasonal, year-to-year and longerterm variation, as well as initialisation or validation of ocean carbon models and coupled climate-carbon models

An update to the Surface Ocean CO2 Atlas (SOCAT version 2)

The Surface Ocean CO2 Atlas (SOCAT), an activity of the international marine carbon research community, provides access to synthesis and gridded fCO(2) (fugacity of carbon dioxide) products for the surface oceans. Version 2 of SOCAT is an update of the previous release (version 1) with more data (increased from 6.3 million to 10.1 million surface water fCO(2) values) and extended data coverage (from 1968-2007 to 1968-2011). The quality control criteria, while identical in both versions, have been applied more strictly in version 2 than in version 1. The SOCAT website (http://www.socat.info/) has links to quality control comments, metadata, individual data set files, and synthesis and gridded data products. Interactive online tools allow visitors to explore the richness of the data. Applications of SOCAT include process studies, quantification of the ocean carbon sink and its spatial, seasonal, year-to-year and longer-term variation, as well as initialisation or validation of ocean carbon models and coupled climate-carbon models.</p

Risk factors for unintentional poisoning in children aged 1–3 years in NSW Australia: a case–control study

BACKGROUND: Unintentional poisoning in young children is an important public health issue. Age pattern studies have demonstrated that children aged 1–3 years have the highest levels of poisoning risk among children aged 0–4 years, yet little research has been conducted regarding risk factors specific to this three-year age group and the methodologies employed varied greatly. The purpose of the current study is to investigate a broad range of potential risk factors for unintentional poisoning in children aged 1–3 years using appropriate methodologies. METHODS: Four groups of children, one case group (children who had experienced a poisoning event) and three control groups (children who had been ‘injured’, ‘sick’ or who were ‘healthy’), and their mothers (mother-child dyads) were enrolled into a case–control study. All mother-child dyads participated in a 1.5-hour child developmental screening and observation, with mothers responding to a series of questionnaires at home. Data were analysed as three case–control pairs with multivariate analyses used to control for age and sex differences between child cases and controls. RESULTS: Five risk factors were included in the final multivariate models for one or more case–control pairs. All three models found that children whose mothers used more positive control in their interactions during a structured task had higher odds of poisoning. Two models showed that maternal psychiatric distress increased poisoning risk (poisoning-injury and poisoning-healthy). Individual models identified the following variables as risk factors: less proximal maternal supervision during risk taking activities (poisoning-injury), medicinal substances stored in more accessible locations in bathrooms (poisoning-sick) and lower total parenting stress (poisoning-healthy). CONCLUSIONS: The findings of this study indicate that the nature of the caregiver-child relationship and caregiver attributes play an important role in influencing poisoning risk. Further research is warranted to explore the link between caregiver-child relationships and unintentional poisoning risk. Caregiver education should focus on the benefits of close interaction with their child as a prevention measure

Self-Consistent Multiscale Theory of Internal Wave, Mean-Flow Interactions

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The research reported here produced new effective ways to solve multiscale problems in nonlinear fluid dynamics, such as turbulent flow and global ocean circulation. This was accomplished by first developing new methods for averaging over random or rapidly varying phases in nonlinear systems at multiple scales. We then used these methods to derive new equations for analyzing the mean behavior of fluctuation processes coupled self consistently to nonlinear fluid dynamics. This project extends a technology base relevant to a variety of multiscale problems in fluid dynamics of interest to the Laboratory and applies this technology to those problems. The project's theoretical and mathematical developments also help advance our understanding of the scientific principles underlying the control of complex behavior in fluid dynamical systems with strong spatial and temporal internal variability