349 research outputs found

    Northwest Forest Plan The First 15 Years (1994-2008): Watershed Condition Status and Trend

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    We used two data sets to evaluate stream and watershed condition for sixth-field watersheds in each aquatic province within the Northwest Forest Plan (NWFP) area: stream data and upslope data. The stream evaluation was based on inchannel data (e.g., substrate, pieces of large wood, water temperature, pool frequency, and macroinvertebrates) we sampled from 2002 to 2009 (193 watersheds) as part of a repeating sample design. We just completed our first round of sampling, so only current condition was calculated for this data set. When condition scores for the inchannel data were grouped into categories, relatively few fell into the low (10 percent) and very low (1 percent) categories. The majority of inchannel attribute scores fell into the moderate (35 percent) and high (41 percent) condition ranges, with relatively few (12 percent) in the very high category. For low-scoring watersheds, water temperature was often the most influential factor. Aquatic invertebrate scores also appeared influential in producing the low scores. An evaluation of upslope and riparian (watershed-wide) conditions for all 1,379 sixth-field watersheds in the NWFP area with significant federal ownership was based on mapped data, including road metrics from U.S. Forest Service and Bureau of Land Management geographic information system road layers and vegetation metrics derived from satellite imagery. Watershed-wide condition scores were calculated for 1994 and 2008, and the difference between these scores was used to represent trend. Regarding status, the overall condition scores of the 1,379 watersheds mostly fell into the low (21 percent), moderate (27 percent), high (26 percent), and very high (22 percent) categories; relatively few watersheds scored in the very low (4 percent) category. The majority of watersheds (69 percent) had a positive change in condition scores (trend). Of those with larger positive changes, most were driven by both improvements in road (decommissioning) and vegetation (natural growth) scores. The greatest negative score changes were caused by the Biscuit Fire and other fires along the eastern side of the Cascades. Half of the fire-affected watersheds were in congressional reserves, 35 percent in late-successional reserves, and 15 percent in matrix (lands identified for timber production)

    Carbon monoxide fluxes measured using the eddy covariance method from an intensively managed grassland in Ireland

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    Carbon monoxide (CO) is classed as a secondary greenhouse gas (GHG) as it can extend the lifetime of GHGs such as methane and ozone by reacting with hydroxyl (OH) radicals and thus controlling the oxidizing capacity of the atmosphere. CO fluxes were measured from a fertilized and grazed temperate grassland in south-east Ireland using a high frequency quantum cascade laser (QCL) and the eddy covariance method. Measurements were carried out in 2019 (12 months) and 2020 (10 months). In both datasets, a diurnal pattern was observed where CO fluxes peaked between 8 am and 6 pm, and between 8 pm and 2 am during the colder months of the year. Quality controlled CO flux data was gap-filled using a general additive model (GAM) that incorporated photosynthetic photon flux density (PPFD), air temperature, water-filled pore space (WFPS) and month of the year. Modelled CO emissions showed less divergence with measured CO fluxes in 2020 compared to 2019, suggesting that the environmental variables in the GAM were the predominant driver of CO emissions in 2020 but not in 2019. Cumulative CO emissions in 2019 and 2020 were 39.7 ± 147.1 mgCO–C per m2 per month and 31.5 ± 75.2 mgCO–C per m2 per month, respectively. While soils are typically considered a sink of CO, our results show that managed pastures can act as a source of CO and thus warrant further investigation into the implications CO may have on GHG dynamics from agricultural landscapes

    Nitrogen fertiliser interactions with urine deposit affect nitrous oxide emissions from grazed grasslands

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    Cattle excreta deposited on grazed pastures are responsible for one fifth of the global anthropogenic nitrous oxide (N2O) emissions. One of the key nitrogen (N) sources is urine deposited from grazing animals, which contributes to very large N loadings within small areas. The main objective of this plot study was to establish whether the application of N fertiliser and urine deposit from dairy cows synergistically interacts and thereby increases N2O emissions, and how such interaction is influenced by the timing of application. The combined application of fertiliser (calcium ammonium nitrate) and urine significantly increased the cumulative N2O emissions as well as the N2O emission factor (EF) from 0.35 to 0.74 % in spring and from 0.26 to 0.52 % in summer. By contrast, EFs were lower when only fertiliser (0.31 % in spring, 0.07 % in summer) or urine was applied (0.33 % in spring, 0.28 % in summer). In autumn, N2O emissions were larger than in other seasons and the emissions from the combined application were not statistically different to those from either the separately applied urine or N fertiliser (EF ranging from 0.72 to 0.83, p-value < 0.05). The absence of significant synergistic effect could be explained by weather conditions, particularly rainfall during the three days prior to and after application in autumn. This study implies that the interactive effects of N fertilisation and urine deposit, as well as the timing of the application on N2O emission need to be taken into account in greenhouse gas emission inventories

    A Leptin-regulated Circuit Controls Glucose Mobilization During Noxious Stimuli

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    Adipocytes secrete the hormone leptin to signal the sufficiency of energy stores. Reductions in circulating leptin concentrations reflect a negative energy balance, which augments sympathetic nervous system (SNS) activation in response to metabolically demanding emergencies. This process ensures adequate glucose mobilization despite low energy stores. We report that leptin receptor–expressing neurons (LepRb neurons) in the periaqueductal gray (PAG), the largest population of LepRb neurons in the brain stem, mediate this process. Application of noxious stimuli, which often signal the need to mobilize glucose to support an appropriate response, activated PAG LepRb neurons, which project to and activate parabrachial nucleus (PBN) neurons that control SNS activation and glucose mobilization. Furthermore, activating PAG LepRb neurons increased SNS activity and blood glucose concentrations, while ablating LepRb in PAG neurons augmented glucose mobilization in response to noxious stimuli. Thus, decreased leptin action on PAG LepRb neurons augments the autonomic response to noxious stimuli, ensuring sufficient glucose mobilization during periods of acute demand in the face of diminished energy stores

    Bifidobacterial biofilm formation is a multifactorial adaptive phenomenon in response to bile exposure

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    In the current study, we show that biofilm formation by various strains and species belonging to Bifidobacterium, a genus that includes gut commensals with reported health-promoting activities, is induced by high concentrations of bile (0.5% (w/v) or higher) and individual bile salts (20&nbsp;mM or higher), rather than by acid or osmotic stress. The transcriptomic response of a bifidobacterial prototype Bifidobacterium breve UCC2003 to such high bile concentrations was investigated and a random transposon bank of B. breve UCC2003 was screened for mutants that affect biofilm formation in order to identify genes involved in this adaptive process. Eleven mutants affected in their ability to form a biofilm were identified, while biofilm formation capacity of an insertional mutation in luxS and an exopolysaccharide (EPS) negative B. breve UCC2003 was also studied. Reduced capacity to form biofilm also caused reduced viability when exposed to porcine bile. We propose that bifidobacterial biofilm formation is an adaptive response to high concentrations of bile in order to avoid bactericidal effects of high bile concentrations in the gastrointestinal environment. Biofilm formation appears to be a multi-factorial process involving EPS production, proteins and extracellular DNA release, representing a crucial strategy in response to bile stress in order to enhance fitness in the gut environment

    Data Package of Samples Collected for Hydrogeologic and Geochemical Characterization: 300 Area RI/FS Sediment Cores

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    This is a data package for sediment samples received from the 300 FF 5 OU. This report was prepared for CHPRC. Between August 16, 2010 and April 25, 2011 sediment samples were received from 300-FF-5 for geochemical studies. The analyses for this project were performed at the 331 building located in the 300 Area of the Hanford Site. The analyses were performed according to Pacific Northwest National Laboratory (PNNL) approved procedures and/or nationally recognized test procedures. The data sets include the sample identification numbers, analytical results, estimated quantification limits (EQL), and quality control data. The preparatory and analytical quality control requirements, calibration requirements, acceptance criteria, and failure actions are defined in the on-line QA plan 'Conducting Analytical Work in Support of Regulatory Programs' (CAW). This QA plan implements the Hanford Analytical Services Quality Assurance Requirements Documents (HASQARD) for PNNL

    Phosphorus and nitrogen losses from temperate permanent grassland on clay-loam soil after the installation of artificial mole and gravel mole drainage

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    peer-reviewedMole (M) and gravel-mole (GM) drainage systems improve the permeability of soils with high clay contents. They collect and carry away infiltrating water during episodic rainfall events. Characterisation of nutrient fluxes (concentration and flows) in overland flow (OF) and in mole drain flow (MF) across sequential rainfall events is important for environmental assessment of such drainage systems. The objective of this study is to assess the impact of drainage systems on soil nutrient losses. Three treatments were imposed on grazed permanent grassland on a clay loam soil in Ireland (52°30′N, 08°12′W) slope 1.48%: undrained control (C), mole drainage (M) and gravel mole drainage (GM). Plots (100 m × 15 m) were arranged in a randomized complete block design with four replicated blocks. Nitrogen (N) and phosphorus (P) concentrations in OF, MF and groundwater (GW) were measured from each plot over 15 consecutive rainfall events. The results showed that M and GM (P < 0.05) deepened the watertable depth and decreased OF. M and GM increased losses of nitrate-N (22%) and ammonium-N (14%) in GW. Nitrate-N concentrations from all the flow pathways (mean and standard error (s.e.): 0.99 s.e. 0.10 mg L−1) were well below the 11.3 mg L−1 threshold for drinking water. Ammonium-N concentrations from all the flow pathways (mean: 0.64 s.e. 0.14 mg L−1) exceeded drinking water quality standards. On the other hand M and GM lowered total P losses (mean annual losses from C, M and GM: 918, 755 and 853 s.e. 14.1 g ha−1 year−1) by enhancing soil P sorption. Hence M and GM can be implemented on farms under similar management to that described in the present study with a minor impact on N (increased concentration on averaged 18% to GW) and P (reduced by on avenged 114 g ha−1 year−1)

    Hanford Site Guidelines for Preparation and Presentation of Geologic Information

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    A complex geology lies beneath the Hanford Site of southeastern Washington State. Within this geology is a challenging large-scale environmental cleanup project. Geologic and contaminant transport information generated by several U.S. Department of Energy contractors must be documented in geologic graphics clearly, consistently, and accurately. These graphics must then be disseminated in formats readily acceptable by general graphics and document producing software applications. The guidelines presented in this document are intended to facilitate consistent, defensible, geologic graphics and digital data/graphics sharing among the various Hanford Site agencies and contractors
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