7 CFR 1493.40 - Application for payment guarantee.

Code of Federal Regulations, 2012 CFR

2012-01-01

... CORPORATION, DEPARTMENT OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Export Credit Guarantee Program (GSM-102) and CCC Intermediate Export Credit Guarantee Program (GSM-103) Operations § 1493..., if necessary, a request for CCC to reserve coverage up to the maximum quantity permitted by the...

7 CFR 1493.40 - Application for payment guarantee.

Code of Federal Regulations, 2014 CFR

2014-01-01

... CORPORATION, DEPARTMENT OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Export Credit Guarantee Program (GSM-102) and CCC Intermediate Export Credit Guarantee Program (GSM-103) Operations § 1493..., if necessary, a request for CCC to reserve coverage up to the maximum quantity permitted by the...

7 CFR 1493.40 - Application for payment guarantee.

Code of Federal Regulations, 2013 CFR

2013-01-01

... CORPORATION, DEPARTMENT OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Export Credit Guarantee Program (GSM-102) and CCC Intermediate Export Credit Guarantee Program (GSM-103) Operations § 1493..., if necessary, a request for CCC to reserve coverage up to the maximum quantity permitted by the...

Wood Export and Deposition Dynamics in Mountain Watersheds

NASA Astrophysics Data System (ADS)

Senter, Anne Elizabeth

Wood dynamics that store, transport, break down, and ultimately export wood pieces through watershed networks are key elements of stream complexity and ecosystem health. Efforts to quantify wood processes are advancing rapidly as technological innovations in field data collection, remotely sensed data acquisition, and data analyses become increasingly sophisticated. The ability to extend the temporal and spatial scales of wood data acquisition has been particularly useful to the investigations presented herein. The primary contributions of this dissertation are focused on two aspects of wood dynamics: watershed-scale wood export processes as identified using the depositional environment of a mountain reservoir, and wood deposition mechanisms in a bedrock-dominated mountain river. Three chapters present this work: In Chapter 1, continuous video monitoring of wood in transport revealed seasonal and diurnal hydrologic cycle influences on the variable rates at which wood transports. This effort supports the efficacy of utilizing continuous data collection methods for wood transport studies. Annual wood export data were collected via field efforts and aerial image analyses from New Bullards Bar Reservoir on the North Yuba River, Sierra Nevada, California. Examination of data revealed linkages between decadal-scale climatic patterns, large flood events, and episodic wood export quantities. A watershed-specific relation between wood export quantities and annual peak discharge contributes to the notion that peak discharge is a primary control on wood export, and yielded prediction of annual wood export quantities where no data were available. Linkages between seasonality, climatic components, and hydrologic events that exert variable control on watershed scale wood responses are presented as a functional framework. An accompanying conceptual model supports the framework presumption that wood responses are influenced by seasonal variations in Mediterranean-montane climate conditions and accompanying hydrologic responses. Chapter 2 contains development of new theory in support of the introduction of multiplicative coefficients, categorized by water year type, that were used to predict wood export quantities via utilization of an existing discharge-based theoretical equation. This new theory was the product of continued investigations into watershed-scale factors in search of explanation of observed variation of wood export rates into New Bullards Bar Reservoir. The gap between known variability and the attribution of wood export to one hydrologic relation continues to be a persistent issue, as the hierarchical and stochastic temporal and spatial nature of wood budget components remain difficult to quantify. The development of "watershed processes" coefficients was specifically focused on a generalized, parsimonious approach using water year type categories, with validation exercises supporting the approach. In dry years, predictions more closely represented observed wood export quantities, whereas the previously derived annual peak discharge relation yielded large over-predictions. Additional data are needed to continue development of these watershed-specific coefficients. This new approach to wood export prediction may be beneficial in regulated river systems for planning purposes, and its efficacy could be tested in other watersheds. Chapter 3 presents the results of an investigation into wood deposition mechanisms in a 12.2 km segment of the confined, bedrock-dominated South Yuba River watershed. Inclusion of coarse wood particles in the analyses was essential in recognizing depositional patterns, thus supporting the value of utilizing a wider wood-size range. A near-census data collection effort yielded myriad data, of which topographic wetted width and bed elevation data, developed for an observed 4.5-year flood event, were standardized in 10-m intervals and then univariate and linked values were ordered into landform classifications using decision tree analyses. Digital imagery collected via kite-blimp was mosaicked into a geographic information system and all resolvable wood pieces greater then 2.5 cm in one dimension were delineated and categorized into piece count density classes. Visual imagery was also key in identifying two river corridor terrains: bedrock outcrops and cobble-boulder-vegetation patches. A conceptual model framed an investigation into how topographic variability and structural elements might influence observed wood deposition dynamics. Forage ratio test results that quantified wood piece utilization versus interval availability revealed that high-density wood deposition patterns were most significantly co-located with five discrete bedrock outcrops that dominated small portions of the river corridor in high flow conditions. Topographic variations and cobble-boulder-vegetation patches were found to be subordinate factors in wood deposition patterns. Bedrock outcrops with specific structural components were the primary depositional environments that acted as floodplain extents for coarse wood deposition, with mechanisms such as topographic steering, eddying, trapping, stranding, backwater effects, and lateral roughness features inferred to be responsible for observed wood deposition patterns.

Template for Annual Report for a Person Exporting Cathode Ray Tubes (CRTs) for Recycling

EPA Pesticide Factsheets

CRT exporters must file with EPA no later than March 1 of each year, an annual report summarizing the quantities, frequency of shipment, and ultimate destination(s) of all used CRTs exported during the previous calendar year.

40 CFR 82.23 - Transfers of allowances of class II controlled substances.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., any production, and allowable imports and exports of class II controlled substances reported by the... quantity of the transferor's class II consumption allowances, production allowances, export production... EPA; and (G) For trades of consumption allowances, production allowances, export production allowances...

The role of hydrology in annual organic carbon loads and terrestrial organic matter export from a midwestern agricultural watershed

NASA Astrophysics Data System (ADS)

Dalzell, Brent J.; Filley, Timothy R.; Harbor, Jon M.

2007-03-01

Defining the control that hydrology exerts on organic carbon (OC) export at the watershed scale is important for understanding how the source and quantity of OC in streams and rivers is influenced by climate change or by landscape drainage. To this end, molecular (lignin phenol), stable carbon isotope, and dissolved organic carbon (DOC) data were collected over a range of flow conditions to examine the influence of hydrology on annual OC export from an 850 km 2 Midwestern United States agricultural watershed located in west central Indiana. In years 2002 and 2003, modeled annual DOC loads were 19.5 and 14.1 kg ha -1yr -1, while 71% and 85%, respectively, of the total annual OC was exported in flow events occurring during less than 20% of that time. These results highlight the importance of short-duration, high-discharge events (common in smaller watersheds) in controlling annual OC export. Based on reported increases in annual stream discharge coupled with current estimates of DOC export, annual DOC loads in this watershed may have increased by up to 40% over the past 50 years. Molecular (lignin phenol) characterization of quantity and relative degradation state of terrestrial OC shows as much temporal variability of lignin parameters (in high molecular weight dissolved organic carbon) in this one watershed as that demonstrated in previously published studies of dissolved organic matter in the Mississippi and Amazon Rivers. These results suggest that hydrologic variability is at least as important in determining the nature and extent of OC export as geographic variability. Moreover, molecular and bulk stable carbon isotope data from high molecular weight dissolved organic carbon and colloidal organic carbon showed that increased stream flow from the study watershed was responsible for increased export of agriculturally derived OC. When considered in the context of results from other studies that show the importance of flood events and in-stream processing of terrestrial organic carbon, our results show how hydrologic variability in smaller watersheds can reflect landscape-scale carbon dynamics in ways that cannot necessarily be measured at the outlets of large rivers due to multiple source signals and attenuated hydrology.

7 CFR 1530.106 - License charges and credits.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., DEPARTMENT OF AGRICULTURE THE REFINED SUGAR RE-EXPORT PROGRAM, THE SUGAR CONTAINING PRODUCTS RE-EXPORT... charged or credited for the quantity of sugar entered, transferred, exported, or used, adjusted to a dry... 100 degrees polarity on a dry weight basis. (1) To adjust the raw value for sugar with a polarization...

7 CFR 1493.430 - Application for a payment guarantee.

Code of Federal Regulations, 2013 CFR

2013-01-01

... CORPORATION, DEPARTMENT OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Supplier... quantity, contract loading tolerance and, if the exporter chooses, a request for CCC to reserve coverage up... is also being used as the basis for an application for participation in any of the following CCC or...

7 CFR 1493.430 - Application for a payment guarantee.

Code of Federal Regulations, 2014 CFR

2014-01-01

... CORPORATION, DEPARTMENT OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Supplier... quantity, contract loading tolerance and, if the exporter chooses, a request for CCC to reserve coverage up... is also being used as the basis for an application for participation in any of the following CCC or...

7 CFR 1493.430 - Application for a payment guarantee.

Code of Federal Regulations, 2012 CFR

2012-01-01

... CORPORATION, DEPARTMENT OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Supplier... quantity, contract loading tolerance and, if the exporter chooses, a request for CCC to reserve coverage up... is also being used as the basis for an application for participation in any of the following CCC or...

15 CFR 745.1 - Advance notification and annual report of all exports of Schedule 1 chemicals to other States...

Code of Federal Regulations, 2014 CFR

2014-01-01

... plan to export any quantity of a Schedule 1 chemical controlled under the EAR and licensed by the... chemicals subject to the EAR or from the Department of State for the export of Schedule 1 chemicals subject... State Party. This is in addition to the requirement to obtain an export license under the EAR for...

15 CFR 745.1 - Advance notification and annual report of all exports of Schedule 1 chemicals to other States...

Code of Federal Regulations, 2012 CFR

2012-01-01

... plan to export any quantity of a Schedule 1 chemical controlled under the EAR and licensed by the... chemicals subject to the EAR or from the Department of State for the export of Schedule 1 chemicals subject... State Party. This is in addition to the requirement to obtain an export license under the EAR for...

15 CFR 745.1 - Advance notification and annual report of all exports of Schedule 1 chemicals to other States...

Code of Federal Regulations, 2013 CFR

2013-01-01

... plan to export any quantity of a Schedule 1 chemical controlled under the EAR and licensed by the... chemicals subject to the EAR or from the Department of State for the export of Schedule 1 chemicals subject... State Party. This is in addition to the requirement to obtain an export license under the EAR for...

Flood Pulse Influence on Export of Terrestrial Organic Matter

NASA Astrophysics Data System (ADS)

Dalzell, B. J.; Harbor, J. M.; Filley, T. R.

2004-12-01

While much attention has been placed on characterizing Terrestrial Organic Matter (TOM) export from large rivers, recent research has shown that in-stream processing of TOM in smaller streams and rivers over shorter time scales can be an important upland component of regional carbon budgets not detected at the outlets of large rivers. With predictions of climate change accompanied by more intense rainfall patterns in some areas, it is important to understand the linkage between flood events and watershed export of TOM. To this end, we have collected water samples from Big Pine Creek watershed, an 850km2 watershed located in west central Indiana. Organic carbon in dissolved, colloidal, and particulate size fractions has been described with molecular and stable carbon isotope techniques to track source, quantity, and compositional changes of TOM over changing flow conditions. Results from these samples show that flood conditions export dramatically more TOM; not only from increases in discharge, but also from increases in concentration of terrestrial organic carbon to all size fractions. While molecular biomarkers show increases in terrestrial organic matter, bulk stable carbon isotope values show that the sources of TOM do not remain constant. Rather, relative contributions from C4 plants (corn in this study area) increase during flood conditions by up to 40 percent. Finally, increases in rainfall intensity are likely to disproportionately increase organic carbon export from terrestrial systems, especially from smaller watersheds where short duration and high intensity flow events dominate annual discharge.

Long-term dynamics of organic matter and elements exported as coarse particulates from two Caribbean montane watersheds

Treesearch

T. Heartsill Scalley; F.N. Scatena; S. Moya; A.E. Lugo

2012-01-01

In heterotrophic streams the retention and export of coarse particulate organic matter and associated elements are fundamental biogeochemical processes that influence water quality, food webs and the structural complexity of forested headwater streams. Nevertheless, few studies have documented the quantity and quality of exported organic matter over multiple years and...

Characteristics of Riverine DIN Export in Subtropical High-standing Island, Taiwan

NASA Astrophysics Data System (ADS)

Huang, J. C.; Kao, S. J.; Lee, T. Y.; Lin, T. C.

2016-12-01

Increases in nitrogen (N) availability and mobility resulting from anthropogenic activities has substantially altered nitrogen cycle both locally and globally. Taiwan characterized by the subtropical montane landscape with abundant rainfall, downwind to the most rapidly industrializing east coast of China can be a demonstration site for extreme high N input and riverine DIN (dissolved inorganic N) export. We used 49 watersheds with similar climatic and landscape settings, but classified into low-, moderate-, and highly-disturbed categories based on population density to illustrate their differences in nitrogen inputs through atmospheric N deposition, synthetic fertilizer and human emission and DIN export ratios. Our results showed that the island-wide average riverine DIN export is 3800 kg-N/km2yr, approximately 18-fold higher than the global average mostly due to the large input of synthetic fertilizer. The average riverine DIN export ratio is 0.30-0.51, which is much higher than the average of 0.20-0.25 of large rivers around the world indicating excessive N input relative to ecosystem demand or retention capacity. The low-disturbed watersheds despite of high input only export 0.06-0.18 of the input and well buffered to changes in input quantity suggesting high efficiency of nitrogen usage or high N retention capacity of the less disturbed watersheds. The moderate-disturbed watersheds show a linear increase of output with increases in total N inputs and a mean DIN export ratio of 0.20 to 0.31. The main differences in land use between low and moderately disturbed watershed are the relative proportions of agricultural land and forests, not the built-up lands. The export ratio of the highly-disturbed watersheds is 0.42-0.53, which is very high and suggests that much of the N input is transported downstream. The increases in riverine DIN export ratio along with the gradient of human disturbance in subtropical Taiwan shows a gradient in excess N saturation. Our results help to understand factors controlling riverine DIN export and provide a sound basis for N emissions/pollution control.

Targeted opportunities to address the climate-trade dilemma in China

NASA Astrophysics Data System (ADS)

Liu, Zhu; Davis, Steven J.; Feng, Kuishuang; Hubacek, Klaus; Liang, Sai; Anadon, Laura Diaz; Chen, Bin; Liu, Jingru; Yan, Jinyue; Guan, Dabo

2016-02-01

International trade has become the fastest growing driver of global carbon emissions, with large quantities of emissions embodied in exports from emerging economies. International trade with emerging economies poses a dilemma for climate and trade policy: to the extent emerging markets have comparative advantages in manufacturing, such trade is economically efficient and desirable. However, if carbon-intensive manufacturing in emerging countries such as China entails drastically more CO2 emissions than making the same product elsewhere, then trade increases global CO2 emissions. Here we show that the emissions embodied in Chinese exports, which are larger than the annual emissions of Japan or Germany, are primarily the result of China’s coal-based energy mix and the very high emissions intensity (emission per unit of economic value) in a few provinces and industry sectors. Exports from these provinces and sectors therefore represent targeted opportunities to address the climate-trade dilemma by either improving production technologies and decarbonizing the underlying energy systems or else reducing trade volumes.

27 CFR 28.321 - Tax assessed on loss not accounted for.

Code of Federal Regulations, 2010 CFR

2010-04-01

... TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Losses Beer and Beer Concentrate... penalties and interest, on; (a) The quantity of beer not satisfactorily accounted for, or (b) the quantity of beer used to produce the quantity of beer concentrate which is not satisfactorily accounted for...

27 CFR 28.321 - Tax assessed on loss not accounted for.

Code of Federal Regulations, 2012 CFR

2012-04-01

... TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Losses Beer and Beer Concentrate... penalties and interest, on; (a) The quantity of beer not satisfactorily accounted for, or (b) the quantity of beer used to produce the quantity of beer concentrate which is not satisfactorily accounted for...

27 CFR 28.321 - Tax assessed on loss not accounted for.

Code of Federal Regulations, 2013 CFR

2013-04-01

... TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL EXPORTATION OF ALCOHOL Losses Beer and Beer Concentrate... penalties and interest, on; (a) The quantity of beer not satisfactorily accounted for, or (b) the quantity of beer used to produce the quantity of beer concentrate which is not satisfactorily accounted for...

27 CFR 28.321 - Tax assessed on loss not accounted for.

Code of Federal Regulations, 2014 CFR

2014-04-01

... TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL EXPORTATION OF ALCOHOL Losses Beer and Beer Concentrate... penalties and interest, on; (a) The quantity of beer not satisfactorily accounted for, or (b) the quantity of beer used to produce the quantity of beer concentrate which is not satisfactorily accounted for...

21 CFR 1304.22 - Records for manufacturers, distributors, dispensers, researchers, importers and exporters.

Code of Federal Regulations, 2010 CFR

2010-04-01

... other controlled or noncontrolled substances in finished form, (i) The name of the substance; (ii) The... manufactured; (E) The quantity used in quality control; (F) The quantity lost during manufacturing and the... controlled substances used in the manufacturing process; (vi) The quantity used to manufacture other...

27 CFR 28.321 - Tax assessed on loss not accounted for.

Code of Federal Regulations, 2011 CFR

2011-04-01

... TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Losses Beer and Beer Concentrate... penalties and interest, on; (a) The quantity of beer not satisfactorily accounted for, or (b) the quantity of beer used to produce the quantity of beer concentrate which is not satisfactorily accounted for...

Permafrost Thaw and Vegetation Cover Change May Alter Silicon Exports to Arctic Coastal Receiving Waters

NASA Astrophysics Data System (ADS)

Spencer, R.; Carey, J.; Tang, J.

2016-12-01

Silicon (Si) availability in Arctic coastal waters is a critical factor dictating phytoplankton species composition, as diatoms require as much Si as nitrogen (N) on a molar basis to survive. Riverine exports are the main source of Si to Arctic coastal waters annually and thus, the timing and magnitude of river Si fluxes have direct implications for marine ecology and global carbon dynamics. Although geochemical factors exert large controls on Si exports to marine waters, watershed land cover has recently been shown to alter the retention and transport of Si along the land-ocean continuum in lower latitudes, due in large part to the ability of terrestrial vegetation to store large quantities of Si in its tissue. However, it is unclear how shifts in basin land cover and climatic warming will alter Si exports in the Arctic, as increasing shrubiness and northward migration of treeline may increase Si retention on land, but permafrost thaw and elevated weathering rates may stimulate Si exports towards coastal waters. In this study we investigate how permafrost thaw and vegetation cover shifts are altering Arctic riverine Si export using the geochemical signatures of ten rivers draining a 700 km north-south gradient across the Yukon and Arctic North Slope basins in Alaska. Across the 2016 spring freshet, average dissolved Si (DSi) concentrations across sites ranged from 22 to 115 µM, with a significant negative relationship observed between average DSi concentration and latitude (r=-0.95, p<0.05). Conversely, average biogenic Si (BSi) concentrations showed no trends with latitude and were more uniform across the permafrost-vegetation cover gradient, ranging from 8 to 15 µM BSi. Si yields followed a similar pattern as concentrations across the gradient. We use data on basin lithology and land cover, instantaneous discharge, and the concentrations of inorganic nutrients (N, phosphorous), chlorophyll a, total suspended solids (TSS), and Ge (Germanium)/Si ratios, to determine the drivers of these patterns in Si behavior. In turn, our results will be used to create the first predictive framework to assess how future warming will alter fluvial Si exports to Arctic receiving waters.

Estimated historical and current nitrogen balances for Illinois.

PubMed

David, M B; McIsaac, G F; Royer, T V; Darmody, R G; Gentry, L E

2001-10-23

The Midwest has large riverine exports of nitrogen (N), with the largest flux per unit area to the Mississippi River system coming from Iowa and Illinois. We used historic and current data to estimate N inputs, outputs, and transformations for Illinois where human activity (principally agriculture and associated landscape drainage) have had a dominant impact. Presently, approximately 800,000 Mg of N is added each year as fertilizer and another 420,000 Mg is biologically fixed, primarily by soybean (Glycine max L. Merr.). These annual inputs are greater than exports in grain, which results in surplus N throughout the landscape. Rivers within the state export approximately 50% of this surplus N, mostly as nitrate, and the remainder appears to be denitrified or temporarily incorporated into the soil organic matter pool. The magnitude of N losses for 1880, 1910, 1950, and 1990 are compared. Initial cultivation of the prairies released large quantities of N (approximately 500,000 Mg N year(-1)), and resulted in riverine N transport during the late 19th century that appears to have been on the same order of magnitude as contemporary N losses. Riverine flux was estimated to have been at a minimum in about 1950, due to diminished net mineralization and low fertilizer inputs. Residual fertilizer N from corn (Zea mays L.), biological N fixed by soybean, short-circuiting of soil water through artificial drainage, and decreased cropping-system diversity appear to be the primary sources for current N export.

Effect of kafirin protein coating on sensory quality and shelf-life of 'Packham's Triumph' pears during ripening.

PubMed

Buchner, Sonya; Kinnear, Marise; Crouch, Ian J; Taylor, Janet; Minnaar, Amanda

2011-12-01

Pears are exported in large quantities from South Africa, resulting in large revenues. Minimisation of quality losses once the fruit has reached the export destination is as important as following strict export and distribution protocols. Kafirin can form edible films. In this study an edible coating made from 20 g kg(-1) kafirin coating solution was applied as a postharvest treatment to retard quality deterioration of 'Packham's Triumph' pears during storage at the typical ripening temperature (20 °C). Changes in physicochemical and sensory quality were monitored over a period of 24 days. The kafirin coating was unable to retard the onset of ripening but decreased the respiration rate and retarded the progression of senescence. However, moisture loss was exacerbated in the kafirin-coated fruit during ripening at 20 °C, especially towards the end of the shelf-life. The kafirin coating extended the eat-ripe quality of the pears by 1-2 weeks. However, the appearance of the fruit was unacceptable after 14 days of storage in terms of wrinkled skin. Further work is needed to improve the water barrier properties of the kafirin coating by incorporating a wax or triglyceride into the coating formulation or more simply by applying a kafirin coating to waxed fruit. Copyright © 2011 Society of Chemical Industry.

7 CFR 984.472 - Reports of merchantable walnuts shipped.

Code of Federal Regulations, 2010 CFR

2010-01-01

... MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE... shipped; whether they were shipped into domestic or export channels; and for exports, the quantity by... remainder of that marketing year. (b) Reports of walnuts purchased directly from growers by handlers who are...

76 FR 56489 - Request for a License To Export Radioactive Waste

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-13

... NUCLEAR REGULATORY COMMISSION Request for a License To Export Radioactive Waste Pursuant to 10 CFR... quantity End use country Duratek Services, Inc., August Class A radioactive Radionuclide Non-conforming Canada. 17, 2011, August 18, 2011, waste in the form reallocation: materials XW010/02, 11005620. of...

7 CFR 984.472 - Reports of merchantable walnuts shipped.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Reports of merchantable walnuts shipped. 984.472... walnuts shipped. (a) Reports of merchantable walnuts shipped during a month shall be submitted to the... shipped; whether they were shipped into domestic or export channels; and for exports, the quantity by...

7 CFR 984.472 - Reports of merchantable walnuts shipped.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Reports of merchantable walnuts shipped. 984.472... walnuts shipped. (a) Reports of merchantable walnuts shipped during a month shall be submitted to the... shipped; whether they were shipped into domestic or export channels; and for exports, the quantity by...

7 CFR 984.472 - Reports of merchantable walnuts shipped.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Reports of merchantable walnuts shipped. 984.472... walnuts shipped. (a) Reports of merchantable walnuts shipped during a month shall be submitted to the... shipped; whether they were shipped into domestic or export channels; and for exports, the quantity by...

7 CFR 984.472 - Reports of merchantable walnuts shipped.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Reports of merchantable walnuts shipped. 984.472... walnuts shipped. (a) Reports of merchantable walnuts shipped during a month shall be submitted to the... shipped; whether they were shipped into domestic or export channels; and for exports, the quantity by...

Organic carbon and nitrogen export from a tropical dam-impacted floodplain system

NASA Astrophysics Data System (ADS)

Zurbrügg, R.; Suter, S.; Lehmann, M. F.; Wehrli, B.; Senn, D. B.

2012-06-01

Tropical floodplains play an important role in organic matter transport, storage, and transformation between headwaters and oceans. However, the fluxes and quality of organic carbon (OC) and organic nitrogen (ON) in tropical river-floodplain systems are not well constrained. We explored the quantity and characteristics of dissolved and particulate organic matter (DOM and POM) in the Kafue River flowing through the Kafue Flats (Zambia). The Kafue Flats are a tropical dam-impacted river-floodplain system in the Zambezi River basin. During the flooding season, >80% of the Kafue River water passed through the floodplain, mobilizing large quantities of OC and ON, which resulted in a net export of 75 kg OC km-2 d-1 and 2.9 kg ON km-2 d-1, 80% of which was in the dissolved form. Mass budget estimates showed that ON export, denitrification, and burial caused an annual deficit of ~21 000 t N yr-1 in the Kafue Flats. A N isotope balance and the δ15N of DON and PON suggest that N-fixation must level out the large N losses. The elemental C:N ratio of ~20, the δ13C values of higher than -24‰, and spectroscopic properties (excitation-emission matrices) showed that DOM in the river was mainly of terrestrial origin. Despite a threefold increase in OC loads due to inputs from the floodplain, the river DOM characteristics remained relatively constant along the sampled 400-km river reach. This suggested that floodplain DOM had similar properties than DOM from the upstream reservoir. In contrast, based on its low δ13C of -29‰ and the C:N ratio of ~8, POM originated from phytoplankton production in the upstream reservoir and in the floodplain. While the reservoir had little impact on DOM properties, terrestrial POM was efficiently trapped and, instead, phytoplankton-derived POM was discharged to the downstream Kafue Flats.

19 CFR 144.37 - Withdrawal for exportation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Form 7512 or CBP Form 7501 must contain all of the statistical information as provided in § 141.61(e... exportation. (e) Weight, gauge, or measure. Merchandise in bulk and packaged articles which are customarily... excess of 4 liters and cigarettes in quantities in excess of 3 cartons. Also, the address requirement is...

19 CFR 144.37 - Withdrawal for exportation.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Form 7512 or CBP Form 7501 must contain all of the statistical information as provided in § 141.61(e... exportation. (e) Weight, gauge, or measure. Merchandise in bulk and packaged articles which are customarily... excess of 4 liters and cigarettes in quantities in excess of 3 cartons. Also, the address requirement is...

19 CFR 144.37 - Withdrawal for exportation.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Form 7512 or CBP Form 7501 must contain all of the statistical information as provided in § 141.61(e... exportation. (e) Weight, gauge, or measure. Merchandise in bulk and packaged articles which are customarily... excess of 4 liters and cigarettes in quantities in excess of 3 cartons. Also, the address requirement is...

19 CFR 144.37 - Withdrawal for exportation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Form 7512 or CBP Form 7501 must contain all of the statistical information as provided in § 141.61(e... exportation. (e) Weight, gauge, or measure. Merchandise in bulk and packaged articles which are customarily... excess of 4 liters and cigarettes in quantities in excess of 3 cartons. Also, the address requirement is...

19 CFR 144.37 - Withdrawal for exportation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Form 7512 or CBP Form 7501 must contain all of the statistical information as provided in § 141.61(e... exportation. (e) Weight, gauge, or measure. Merchandise in bulk and packaged articles which are customarily... excess of 4 liters and cigarettes in quantities in excess of 3 cartons. Also, the address requirement is...

22 CFR 123.23 - Monetary value of shipments.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Monetary value of shipments. 123.23 Section 123... EXPORT OF DEFENSE ARTICLES § 123.23 Monetary value of shipments. Port Directors of U.S. Customs and... value of the export does not exceed the aggregate monetary value (not quantity) stated on the license by...

Inventory of interbasin transfers of water in the western conterminous United States

USGS Publications Warehouse

Petsch, H.E.

1989-01-01

Information is presented on the quantity of water transferred from one river basin to another in the western conterminous United States. The information is needed by water system managers and planners to develop water budgets for major river basins, to examine the relative extent of existing interbasin transfers, and to define the importance of transferring water to meet regional water demands. All or parts of 11 major water resources regions and 111 complete subregions comprise the study area; water is exported from 39 of these subregions. The average quantity of water exported annually during 1973-82 was about 12 million acre-feet. (USGS)

40 CFR 747.195 - Triethanolamine salt of a substituted organic acid.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., commerce, importer, impurity, Inventory, manufacturer, person, process, processor, and small quantities... control of the processor. (ii) Distribution in commerce is limited to purposes of export. (iii) The processor or distributor may not use the substance except in small quantities solely for research and...

15 CFR 2007.1 - Information required of interested parties in submitting requests for modifications in the last...

Code of Federal Regulations, 2011 CFR

2011-01-01

... duty-free treatment under the GSP have on competition and the business of the interest on whose behalf..., total quantity, value and trends in exports; (8) Information on exports to the United States in terms of... beneficiary countries and trends in their production and promotional activities; (9) Analysis of cost...

15 CFR 2007.1 - Information required of interested parties in submitting requests for modifications in the last...

Code of Federal Regulations, 2010 CFR

2010-01-01

... duty-free treatment under the GSP have on competition and the business of the interest on whose behalf..., total quantity, value and trends in exports; (8) Information on exports to the United States in terms of... beneficiary countries and trends in their production and promotional activities; (9) Analysis of cost...

The challenge of electronic waste (e-waste) management in developing countries.

PubMed

Osibanjo, O; Nnorom, I C

2007-12-01

Information and telecommunications technology (ICT) and computer Internet networking has penetrated nearly every aspect of modern life, and is positively affecting human life even in the most remote areas of the developing countries. The rapid growth in ICT has led to an improvement in the capacity of computers but simultaneously to a decrease in the products lifetime as a result of which increasingly large quantities of waste electrical and electronic equipment (e-waste) are generated annually. ICT development in most developing countries, particularly in Africa, depends more on secondhand or refurbished EEEs most of which are imported without confirmatory testing for functionality. As a result large quantities of e-waste are presently being managed in these countries. The challenges facing the developing countries in e-waste management include: an absence of infrastructure for appropriate waste management, an absence of legislation dealing specifically with e-waste, an absence of any framework for end-of-life (EoL) product take-back or implementation of extended producer responsibility (EPR). This study examines these issues as they relate to practices in developing countries with emphasis on the prevailing situation in Nigeria. Effective management of e-waste in the developing countries demands the implementation of EPR, the establishment of product reuse through remanufacturing and the introduction of efficient recycling facilities. The implementation of a global system for the standardization and certification/labelling of secondhand appliances intended for export to developing countries will be required to control the export of electronic recyclables (e-scarp) in the name of secondhand appliances.

21 CFR 1313.21 - Requirement of authorization to export.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Administration an established business relationship with a foreign customer as defined in § 1300.02(b)(12). (2) A... quantity and date exported; (3) The name and full business address of the foreign customer; (4) The port of... knowledge as provided in § 1313.25. [54 FR 31665, Aug. 1, 1989, as amended at 59 FR 51367, Oct. 11, 1994; 60...

7 CFR 355.21 - Marking and mailing requirements for plants imported, exported, or reexported by mail. 5

Code of Federal Regulations, 2011 CFR

2011-01-01

... Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ENDANGERED SPECIES REGULATIONS CONCERNING TERRESTRIAL PLANTS Inspections and Related Provisions § 355.21 Marking and...) Genus and species, and quantity of each (if a hybrid, genus of each parent, and quantity of each hybrid...

7 CFR 355.21 - Marking and mailing requirements for plants imported, exported, or reexported by mail. 5

Code of Federal Regulations, 2013 CFR

2013-01-01

... Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ENDANGERED SPECIES REGULATIONS CONCERNING TERRESTRIAL PLANTS Inspections and Related Provisions § 355.21 Marking and...) Genus and species, and quantity of each (if a hybrid, genus of each parent, and quantity of each hybrid...

7 CFR 355.21 - Marking and mailing requirements for plants imported, exported, or reexported by mail. 5

Code of Federal Regulations, 2014 CFR

2014-01-01

... Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ENDANGERED SPECIES REGULATIONS CONCERNING TERRESTRIAL PLANTS Inspections and Related Provisions § 355.21 Marking and...) Genus and species, and quantity of each (if a hybrid, genus of each parent, and quantity of each hybrid...

7 CFR 355.21 - Marking and mailing requirements for plants imported, exported, or reexported by mail. 5

Code of Federal Regulations, 2010 CFR

2010-01-01

... Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ENDANGERED SPECIES REGULATIONS CONCERNING TERRESTRIAL PLANTS Inspections and Related Provisions § 355.21 Marking and...) Genus and species, and quantity of each (if a hybrid, genus of each parent, and quantity of each hybrid...

7 CFR 355.21 - Marking and mailing requirements for plants imported, exported, or reexported by mail. 5

Code of Federal Regulations, 2012 CFR

2012-01-01

... Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ENDANGERED SPECIES REGULATIONS CONCERNING TERRESTRIAL PLANTS Inspections and Related Provisions § 355.21 Marking and...) Genus and species, and quantity of each (if a hybrid, genus of each parent, and quantity of each hybrid...

An econometric model of the hardwood lumber market

Treesearch

William G. Luppold

1982-01-01

A recursive econometric model with causal flow originating from the demand relationship is used to analyze the effects of exogenous variables on quantity and price of hardwood lumber. Wage rates, interest rates, stumpage price, lumber exports, and price of lumber demanders' output were the major factors influencing quantities demanded and supplied and hardwood...

77 FR 70151 - 36(b)(1) Arms Sales Notification

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-23

... defined in Section 47(6) of the Arms Export Control Act. (iii) Description and Quantity or Quantities of.... The sensitivity is primarily in the software programs that instruct the system how to operate in the... Only Memory (ROM) maps, which do not provide the software program itself. The overall hardware is...

Dissolved organic carbon fluxes from soils in the Alaskan coastal temperate rainforest

NASA Astrophysics Data System (ADS)

D'Amore, D. V.; Edwards, R.; Hood, E. W.; Herendeen, P. A.; Valentine, D.

2011-12-01

Soil saturation and temperature are the primary factors that influence soil carbon cycling. Interactions between these factors vary by soil type, climate, and landscape position, causing uncertainty in predicting soil carbon flux from. The soils of the North American perhumid coastal temperate rainforest (NCTR) store massive amounts of carbon, yet there is no estimate of dissolved organic carbon (DOC) export from different soil types in the region. There are also no working models that describe the influence of soil saturation and temperature on the export of DOC from soils. To address this key information gap, we measured soil water table elevation, soil temperature, and soil and stream DOC concentrations to calculate DOC flux across a soil hydrologic gradient that included upland soils, forested wetland soils, and sloping bog soils in the NCTR of southeast Alaska. We found that increased soil temperature and frequent fluctuations of soil water tables promoted the export of large quantities of DOC from wetland soils and relatively high amounts of DOC from mineral soils. Average area-weighted DOC flux ranged from 7.7 to 33.0 g C m-2 y-1 across a gradient of hydropedologic soil types. The total area specific export of carbon as DOC for upland, forested wetland and sloping bog catchments was 77, 306, and 329 Kg C ha-1 y-1 respectively. The annual rate of carbon export from wetland soils in this region is among the highest reported in the literature. These findings highlight the importance of terrestrial-aquatic fluxes of DOC as a pathway for carbon loss in the NCTR.

Continuous, Pulsed Export of Methane-Supersaturated Meltwaters from the Bed of the Greenland Ice Sheet

NASA Astrophysics Data System (ADS)

Lamarche-Gagnon, G.; Wadham, J.; Beaton, A.; Fietzek, P.; Stanley, K. M.; Tedstone, A.; Sherwood Lollar, B.; Lacrampe Couloume, G.; Telling, J.; Liz, B.; Hawkings, J.; Kohler, T. J.; Zarsky, J. D.; Stibal, M.; Mowlem, M. C.

2016-12-01

Both past and present ice sheets have been proposed to cap large quantities of methane (CH4), on orders of magnitude significant enough to impact global greenhouse gas concentrations during periods of rapid ice retreat. However, to date most evidence for sub-ice sheet methane has been indirect, derived from calculations of the methanogenic potential of basal-ice microbial communities and biogeochemical models; field-based empirical measurements are lacking from large ice sheet catchments. Here, we present the first continuous, in situ record of dissolved methane export from a large catchment of the Greenland Ice Sheet (GrIS) in South West Greenland from May-July 2015. Our results indicate that glacial runoff was continuously supersaturated with methane over the observation period (dissolved CH4 concentrations of 30-700 nM), with total methane flux rising as subglacial discharge increased. Periodic subglacial drainage events, characterised by rapid changes (i.e. pulses) in meltwater hydrochemistry, also coincided with a rise in methane concentrations. We argue that these are likely indicative of the flushing of subglacial reservoirs of CH4 beneath the ice sheet. Total methane export was relatively modest when compared to global methane budgets, but too high to be explained by previously determined methanogenic rates from Greenland basal ice. Discrepancies between estimated Greenland methane reserves and observed fluxes stress the need to further investigate GrIS methane fluxes and sources, and suggest a more biogeochemically active subglacial environment than previously considered. Results indicate that future warming, and a coincident increase in ice melt rates, would likely make the GrIS, and by extension the Antarctic Ice Sheet, more significant sources of atmospheric methane, consequently acting as a positive feedback to a warming climate.

7 CFR 35.13 - Minimum quantity.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS EXPORT GRAPES... less of vinifera species table grapes, either a single variety or a combination of two or more...

Global Maize Trade and Food Security: Implications from a Social Network Model

PubMed Central

Wu, Felicia; Guclu, Hasan

2013-01-01

In this study, we developed a social network model of the global trade of maize: one of the most important food, feed, and industrial crops worldwide, and critical to food security. We used this model to analyze patterns of maize trade among nations, and to determine where vulnerabilities in food security might arise if maize availability were decreased due to factors such as diversion to non-food uses, climatic factors, or plant diseases. Using data on imports and exports from the United Nations Commodity Trade Statistics Database for each year from 2000 to 2009 inclusive, we summarized statistics on volumes of maize trade between pairs of nations for 217 nations. There is evidence of market segregation among clusters of nations; with three prominent clusters representing Europe, Brazil and Argentina, and the United States. The United States is by far the largest exporter of maize worldwide, while Japan and the Republic of Korea are the largest maize importers. In particular, the star-shaped cluster of the network that represents US maize trade to other nations indicates the potential for food security risks because of the lack of trade these other nations conduct with other maize exporters. If a scenario arose in which US maize could not be exported in as large quantities, maize supplies in many nations could be jeopardized. We discuss this in the context of recent maize ethanol production and its attendant impacts on food prices elsewhere worldwide. PMID:23656551

Global maize trade and food security: implications from a social network model.

PubMed

Wu, Felicia; Guclu, Hasan

2013-12-01

In this study, we developed a social network model of the global trade of maize: one of the most important food, feed, and industrial crops worldwide, and critical to food security. We used this model to analyze patterns of maize trade among nations, and to determine where vulnerabilities in food security might arise if maize availability was decreased due to factors such as diversion to nonfood uses, climatic factors, or plant diseases. Using data on imports and exports from the U.N. Commodity Trade Statistics Database for each year from 2000 to 2009 inclusive, we summarized statistics on volumes of maize trade between pairs of nations for 217 nations. There is evidence of market segregation among clusters of nations; with three prominent clusters representing Europe, Brazil and Argentina, and the United States. The United States is by far the largest exporter of maize worldwide, whereas Japan and the Republic of Korea are the largest maize importers. In particular, the star-shaped cluster of the network that represents U.S. maize trade to other nations indicates the potential for food security risks because of the lack of trade these other nations conduct with other maize exporters. If a scenario arose in which U.S. maize could not be exported in as large quantities, maize supplies in many nations could be jeopardized. We discuss this in the context of recent maize ethanol production and its attendant impacts on food prices elsewhere worldwide. © 2013 Society for Risk Analysis.

Export of microplastics from land to sea. A modelling approach.

PubMed

Siegfried, Max; Koelmans, Albert A; Besseling, Ellen; Kroeze, Carolien

2017-12-15

Quantifying the transport of plastic debris from river to sea is crucial for assessing the risks of plastic debris to human health and the environment. We present a global modelling approach to analyse the composition and quantity of point-source microplastic fluxes from European rivers to the sea. The model accounts for different types and sources of microplastics entering river systems via point sources. We combine information on these sources with information on sewage management and plastic retention during river transport for the largest European rivers. Sources of microplastics include personal care products, laundry, household dust and tyre and road wear particles (TRWP). Most of the modelled microplastics exported by rivers to seas are synthetic polymers from TRWP (42%) and plastic-based textiles abraded during laundry (29%). Smaller sources are synthetic polymers and plastic fibres in household dust (19%) and microbeads in personal care products (10%). Microplastic export differs largely among European rivers, as a result of differences in socio-economic development and technological status of sewage treatment facilities. About two-thirds of the microplastics modelled in this study flow into the Mediterranean and Black Sea. This can be explained by the relatively low microplastic removal efficiency of sewage treatment plants in the river basins draining into these two seas. Sewage treatment is generally more efficient in river basins draining into the North Sea, the Baltic Sea and the Atlantic Ocean. We use our model to explore future trends up to the year 2050. Our scenarios indicate that in the future river export of microplastics may increase in some river basins, but decrease in others. Remarkably, for many basins we calculate a reduction in river export of microplastics from point-sources, mainly due to an anticipated improvement in sewage treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rajamani, S.

The leather industry is an important export-oriented industry in India, with more than 3,000 tanneries located in different clusters. Sodium sulfide, a toxic chemical, is used in large quantities to remove hair and excess flesh from hides and skins. Most of the sodium sulfide used in the process is discharged as waste in the effluent, which causes serious environmental problems. Reduction of sulfide in the effluent is generally achieved by means of chemicals in the pretreatment system, which involves aerobic mixing using large amounts of chemicals and high energy, and generating large volumes of sludge. A simple biotechnological system thatmore » uses the residual biosludge from the secondary settling tank was developed, and the commercial-scale application established that more than 90% of the sulfide could be reduced in the primary treatment system. In addition to the reduction of sulfide, foul smells, BOD and COD are reduced to a considerable level. 3 refs., 2 figs., 1 tab.« less

River export of triclosan from land to sea: A global modelling approach.

PubMed

van Wijnen, Jikke; Ragas, Ad M J; Kroeze, Carolien

2018-04-15

Triclosan (TCS) is an antibacterial agent that is added to commonly used personal care products. Emitted to the aquatic environment in large quantities, it poses a potential threat to aquatic organisms. Triclosan enters the aquatic environment mainly through sewage effluent. We developed a global, spatially explicit model, the Global TCS model, to simulate triclosan transport by rivers to coastal areas. With this model we analysed annual, basin-wide triclosan export for the year 2000 and two future scenarios for the year 2050. Our analyses for 2000 indicate that triclosan export to coastal areas in Western Europe, Southeast Asia and the East Coast of the USA is higher than in the rest of the world. For future scenarios, the Global TCS model predicts an increase in river export of triclosan in Southeast Asia and a small decrease in Europe. The number of rivers with an annual average triclosan concentration at the river mouth that exceeds a PNEC of 26.2ng/L is projected to double between 2000 and 2050. This increase is most prominent in Southeast Asia, as a result of fast population growth, increasing urbanisation and increasing numbers of people connected to sewerage systems with poor wastewater treatment. Predicted triclosan loads correspond reasonably well with measured values. However, basin-specific predictions have considerable uncertainty due to lacking knowledge and location-specific data on the processes determining the fate of triclosan in river water, e.g. sorption, degradation and sedimentation. Additional research on the fate of triclosan in river systems is therefore recommended. We developed a global spatially explicit model to simulate triclosan export by rivers to coastal seas. For two future scenarios this Global TCS model projects an increase in river export of triclosan to several seas around the world. Copyright © 2017 Elsevier B.V. All rights reserved.

Compositionally heterogeneous dissolved organic matter reflects changing flowpaths in a large ice sheet catchment over the course of the melt season at Leverett Glacier, southwest Greenland

NASA Astrophysics Data System (ADS)

Kellerman, A.; Hawkings, J.; Marshall, M.; Spencer, R.; Wadham, J.

2017-12-01

The Greenland Ice Sheet (GrIS) is losing mass at a remarkable rate. This loss of mass coincides with the export of dissolved organic matter (DOM) and other nutrients from the ice sheet and exerts a primary control on secondary production in downstream ecosystems. However, little is known about the source and composition of DOM exported from these dilute, yet immense, systems. Samples were collected from May 11, 2015 to July 29, 2015 from the outflow of Leverett Glacier, a large, land-terminating glacier of the southwest GrIS. Dissolved organic carbon (DOC) concentrations were measured and the optical properties of DOM were characterized using absorbance and fluorescence spectroscopy. At the beginning of the season, when discharge is <5 m3 sec-1, red-shifted fluorescence suggests terrestrial inputs from either overridden soils or proglacial inputs dominate the DOM pool. With the onset of melt, after an initial pulse in both DOC quantity and red-shifted fluorescence intensity, the DOC concentration and fluorescence intensity is diluted, with little change in DOM composition. The terrestrial signal is lost with the first outburst event in late June, and a single protein-like fluorophore is exhibited for three weeks. On July 10th, a fourth outburst event introduces a second protein-like fluorophore, indicative of production on the ice sheet, and this signature is maintained until the end of the July. These results suggest that subglaical drainage flowpaths and water source influence the exported DOC concentration and DOM composition over a summer melt season. As glacial outflow shifts from higher DOC concentrations early in the season to low DOC concentrations later in the summer, these results impact estimates of carbon export from glaciers. Furthermore, as composition is related to reactivity, the compositional changes observed may indicate shifts in the bioavailability of the DOM upon delivery to coastal systems, a result of changing DOM sources over the course of the season.

7 CFR 33.7 - Less than carload lot.

Code of Federal Regulations, 2010 CFR

2010-01-01

... ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.7 Less than carload lot. Less than carload lot means a quantity of apples in packages not exceeding 20,000 pounds gross weight or 400...

7 CFR 33.7 - Less than carload lot.

Code of Federal Regulations, 2014 CFR

2014-01-01

... ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.7 Less than carload lot. Less than carload lot means a quantity of apples in packages not exceeding 20,000 pounds gross weight or 400...

7 CFR 33.7 - Less than carload lot.

Code of Federal Regulations, 2012 CFR

2012-01-01

... ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.7 Less than carload lot. Less than carload lot means a quantity of apples in packages not exceeding 20,000 pounds gross weight or 400...

7 CFR 33.7 - Less than carload lot.

Code of Federal Regulations, 2011 CFR

2011-01-01

... ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.7 Less than carload lot. Less than carload lot means a quantity of apples in packages not exceeding 20,000 pounds gross weight or 400...

7 CFR 33.7 - Less than carload lot.

Code of Federal Regulations, 2013 CFR

2013-01-01

... ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.7 Less than carload lot. Less than carload lot means a quantity of apples in packages not exceeding 20,000 pounds gross weight or 400...

Reengineering ribosome export.

PubMed

Lo, Kai-Yin; Johnson, Arlen W

2009-03-01

Large cargoes require multiple receptors for efficient transport through the nuclear pore complex. The 60S ribosomal subunit is one of the bulkiest transport cargoes, and in yeast three different receptors, Crm1, Mex67/Mtr2, and Arx1, collaborate in its export. However, only Crm1, recruited by the adapter Nmd3, appears to be conserved for 60S export in higher eukaryotes. We asked if export of the large subunit requires specific receptors. We made protein fusions between mutant Nmd3 and various export receptors. Surprisingly, fusions of Mex67, the tRNA exportin Los1, Mtr2, Cse1, or Msn5 to Nmd3, lacking its Crm1-dependent nuclear export signal (NES), all functioned in export. Furthermore, these chimeric proteins supported 60S export even in the presence of the Crm1 inhibitor leptomycin B, indicating that export was now independent of Crm1. These results suggest that there is not a requirement for a specific export receptor for the large subunit, as recruitment of any receptor will suffice. Finally we show that the addition of an NES directly to the 60S ribosomal subunit protein Rpl3 promotes export. These results imply remarkable flexibility in the export pathway for the 60S subunit and help explain how different export receptors could have evolved in different eukaryotic lineages.

Reengineering Ribosome Export

PubMed Central

Lo, Kai-Yin

2009-01-01

Large cargoes require multiple receptors for efficient transport through the nuclear pore complex. The 60S ribosomal subunit is one of the bulkiest transport cargoes, and in yeast three different receptors, Crm1, Mex67/Mtr2, and Arx1, collaborate in its export. However, only Crm1, recruited by the adapter Nmd3, appears to be conserved for 60S export in higher eukaryotes. We asked if export of the large subunit requires specific receptors. We made protein fusions between mutant Nmd3 and various export receptors. Surprisingly, fusions of Mex67, the tRNA exportin Los1, Mtr2, Cse1, or Msn5 to Nmd3, lacking its Crm1-dependent nuclear export signal (NES), all functioned in export. Furthermore, these chimeric proteins supported 60S export even in the presence of the Crm1 inhibitor leptomycin B, indicating that export was now independent of Crm1. These results suggest that there is not a requirement for a specific export receptor for the large subunit, as recruitment of any receptor will suffice. Finally we show that the addition of an NES directly to the 60S ribosomal subunit protein Rpl3 promotes export. These results imply remarkable flexibility in the export pathway for the 60S subunit and help explain how different export receptors could have evolved in different eukaryotic lineages. PMID:19144820

The Bay of Bengal : an ideal laboratory for studying salinity

NASA Astrophysics Data System (ADS)

Vialard, jerome; Lengaigne, Matthieu; Akhil, Valiya; Chaitanya, Akurathi; Krishna-Mohan, Krishna; D'Ovidio, Francesco; Keerthi, Madhavan; Benshila, Rachid; Durand, Fabien; Papa, Fabrice; Suresh, Iyappan; Neetu, Singh

2017-04-01

The Bay of Bengal combines several unique features that make it an excellent laboratory to study the variability of salinity and its potential effects on the oceanic circulation and climate. This basin receives very large quantities of freshwater in association to the southwest monsoon, either directly from rain or indirectly through the runoffs of the Ganges-Brahmaputra and Irrawaddy. This large quantity of freshwater in a small, semi enclosed basin results in some of the lowest sea surface salinities (SSS) and strongest near-surface haline stratification in the tropical band. The strong monsoon winds also drive an energetic circulation, which exports the excess water received during the monsoon and results in strong horizontal salinity gradients. In this talk, I will summarize several studies of the Bay of Bengal salinity variability and its impacts undertaken in the context of an Indo-French collaboration. In situ data collected along the coast by fishermen and model results show that the intense, coastally-trapped East India Coastal Current (EICC) transports the very fresh water near the Ganges-Brahmaputra river mouth along the eastern Bay of Bengal rim to create a narrow, very fresh "river in the sea" after the southwest monsoon. The salinity-induced pressure gradient contributes to almost 50% of the EICC intensity and sustains mesoscale eddy generation through its effect on horizontal current shears and baroclinic gradients. Oceanic eddies play a strong role in exporting this fresh water from the coast to the basin interior. This "river in the sea" has a strong interannual variability related to the EICC remote modulation by the Indian Ocean Dipole (a regional climate mode). I will also discuss the potential effect of haline stratification on the regional climate through its influence on the upper ocean budget. Finally, I will briefly discuss the performance of remote-sensing for observing SSS in the Bay of Bengal.

Dissolved organic matter composition and biodegradability in a permafrost-dominated watershed network in central Siberia

NASA Astrophysics Data System (ADS)

Coble, A. A.; Rodriguez-Cardona, B.; Wymore, A.; Prokishkin, A. S.; Kolosov, R.; McDowell, W. H.

2016-12-01

Thawing permafrost soils can mobilize large quantities of dissolved organic matter (DOM) from soils to headwater streams, and DOM may undergo rapid transformations in streams and rivers in transit to the Arctic Ocean. With climate change an increased frequency of fire is also expected, which will further alter the DOM entering streams, and may contribute to changes in its biodegradability. Elucidating how DOM composition varies across a fire gradient within a river network underlain by continuous permafrost will therefore improve our understanding of the impact of climate change on Arctic ecosystems and its role in the global carbon cycle. To determine DOM composition we measured optical properties via excitation-emission matrices (EEMs) and subsequent parallel factor analysis across a spatially extensive collection of sites in central Siberia. Within a subset of streams in the Nizhnyaya Tunguska watershed network, we also measured biodegradable dissolved organic carbon (BDOC) incubated at in situ temperatures over a 7 day period during spring freshet on two dates in early June. Despite clear changes in optical properties of DOM and background DOC concentration along the fire gradient (range: 3 to >100 y since burn) BDOC did not vary systematically with years since fire for either incubation date. In the first incubation conducted near peak flow BDOC ranged from negligible to 7.6% (BDOC concentration = negligible to 1.4 mg C L-1) within a 7 day period. In the second incubation conducted 5 days later BDOC was negligible across all sites (as both a percentage and a concentration). Our results suggest that DOC exported from permafrost soils in the central Siberian plateau is relatively unreactive at in situ temperatures over 7 day time scales, which contrasts with previous studies conducted in watersheds underlain with Yedoma outcrops where biodegradability comprises a large fraction of DOC. Our preliminary results suggest that melting of permafrost soils in central Siberia may export large quantities of C to the Arctic Ocean that are not rapidly degraded in streams and rivers.

Improved (ERTS) information and its impact on U.S. markets for agricultural commodities: A quantitiative economic investigation of production, distribution and net export effects

NASA Technical Reports Server (NTRS)

1974-01-01

An econometric investigation into the markets for agricultural commodities is summarized. An overview of the effort including the objectives, scope, and architecture of the analysis and the estimation strategy employed is presented. The major empirical results and policy conclusions are set forth. These results and conclusions focus on the economic importance of improved crop forecasts, U.S. exports, and government policy operations. A number of promising avenues of further investigation are suggested.

The national biennial RCRA hazardous waste report (based on 1997 data) : national analysis

DOT National Transportation Integrated Search

1999-09-01

National Analysis presents a detailed look at waste-handling practices in the EPA Regions, States, and largest facilities nationally, including (1) the quantity of waste generated, managed, shipped and received, and imported and exported between Stat...

Cultured 3T3L1 adipocytes dispose of excess medium glucose as lactate under abundant oxygen availability

NASA Astrophysics Data System (ADS)

Sabater, David; Arriarán, Sofía; Romero, María Del Mar; Agnelli, Silvia; Remesar, Xavier; Fernández-López, José Antonio; Alemany, Marià

2014-01-01

White adipose tissue (WAT) produces lactate in significant amount from circulating glucose, especially in obesity;Under normoxia, 3T3L1 cells secrete large quantities of lactate to the medium, again at the expense of glucose and proportionally to its levels. Most of the glucose was converted to lactate with only part of it being used to synthesize fat. Cultured adipocytes were largely anaerobic, but this was not a Warburg-like process. It is speculated that the massive production of lactate, is a process of defense of the adipocyte, used to dispose of excess glucose. This way, the adipocyte exports glucose carbon (and reduces the problem of excess substrate availability) to the liver, but the process may be also a mechanism of short-term control of hyperglycemia. The in vivo data obtained from adipose tissue of male rats agree with this interpretation.

Analysis of Maize versus Ethanol Production in Nebraska, United States and International Agricultural Droughts: Lessons for Global Food Security

NASA Astrophysics Data System (ADS)

Boken, V.; Tenkorang, F.

2012-04-01

Nebraska is one of the eight main corn (maize) belt states of the United States. Maize is the major crop of Nebraska with an average annual production of about 38 million tons (about 12% of U.S. production), which contributes billions of dollars to the state's economy. The yield of maize has increased significantly over the past century - from 1.6 t/ha in 1900 to 10.4 t/ha in 2010. While the majority of maize (about 40%) is currently used for animal feed and ethanol production, only about six percent is exported. It is estimated that about one billion people accounting for about 15% population of the world live in chronic hunger because of low agricultural productivity and drought. Most of these people depend on the U.S. for grains including maize. If a greater quantity of maize is diverted to ethanol production, considerably less quantity of maize would be available for export to developing countries where it could be used for human consumption and to mitigate hunger and improve food security. This paper presents analysis of maize production in Nebraska for the past three decades and examines how its commercialization for ethanol production has affected its exports in the face of drought at an international level.

19 CFR 351.409 - Differences in quantities.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE ANTIDUMPING AND COUNTERVAILING... the line of trade and market under consideration, the exporter or producer demonstrates that it has adhered to its price list. (e) Relationship to level of trade adjustment. If adjustments are claimed for...

Shrimp culture in Thailand: environmental impacts and social responses.

PubMed

Gronski, R

2000-01-01

Black tiger shrimp (Penaeus monodon) is a major aquaculture commodity among Southeast Asian producers and remains a popular food export world-wide. Food brokers in Japan and the United States purchase huge quantities of these farmed shrimp and return significant foreign exchange earnings to developing nations like Thailand, a major producer and exporter since the early 1990s. However, coastal areas cannot sustain intensive shrimp farm production and local growers often end up in debt. Can the needs of farm communities around the world be suitably met when they join into a corporate-managed and export-oriented food system? What are the sustainable benefits and eventual costs to susceptible localities? The shrimp industry in Thailand reveals the difficult terrain to cross and powerful obstacles to overcome if authentic sustainable development is to be realized.

27 CFR 44.142 - Records.

Code of Federal Regulations, 2012 CFR

2012-04-01

... cigarettes); (d) Name of manufacturer and brand; and, (e) Quantity of tobacco products, cigarette papers and... sentence of paragraph (e) by adding the words “, and any processed tobacco” after the words “cigarette... TREASURY (CONTINUED) TOBACCO EXPORTATION OF TOBACCO PRODUCTS AND CIGARETTE PAPERS AND TUBES, WITHOUT...

27 CFR 44.142 - Records.

Code of Federal Regulations, 2011 CFR

2011-04-01

... cigarettes); (d) Name of manufacturer and brand; and, (e) Quantity of tobacco products, cigarette papers and... sentence of paragraph (e) by adding the words “, and any processed tobacco” after the words “cigarette... TREASURY (CONTINUED) TOBACCO EXPORTATION OF TOBACCO PRODUCTS AND CIGARETTE PAPERS AND TUBES, WITHOUT...

‘Skullduggery’: Lions Align and Their Mandibles Rock!

PubMed Central

Williams, Vivienne L.; Loveridge, Andrew J.; Newton, David J.; Macdonald, David W.

2015-01-01

South Africa has legally exported substantial quantities of lion bones to Southeast Asia and China since 2008, apparently as part of the multinational trade substituting bones and body parts of other large cats for those of the tiger in wine and other health tonics. The legal sale of lion bones may mask an illegal trade, the size of which is only partially known. An observed component of the illegal trade is that quantities of skeletons are sometimes declared falsely/fraudulently on CITES export permits. Furthermore, there are emerging concerns that bones from tigers reared in captivity in South Africa and elsewhere are being laundered as lion bones using CITES Appendix II permits. There is therefore a need for tools to monitor the trade in lion body parts and to distinguish between lions and tigers. Our research indicates that it is possible to use skeletons, skulls and cranial sutures to detect misdeclarations in the lion bone trade. It is also possible to use the average mass of a lion skeleton to corroborate the numbers of skeletons declared on CITES permits, relative to the weight of the consolidated consignments stated on the air waybills. When the mass of consolidated consignments of skeletons destined for export was regressed against the number of skeletons in that consignment, there was a strong correlation between the variables (r2 = 0.992) that can be used as a predictor of the accuracy of a declaration on a CITES permit. Additionally, the skulls of lions and tigers differ: two cranial sutures of lions align and their mandibles rock when placed on a flat surface, whereas the cranial sutures of tigers are not aligned and their mandibles rest naturally on two contact points. These two morphological differences between the skulls of tigers and lions are easy to observe at a glance and provide a method for distinguishing between the species if illegal trade in the bones is suspected and the skulls are present. These identifications should ideally be confirmed by a DNA test to provide rigorous evidence to prosecute offenders violating CITES regulations. PMID:26536601

'Skullduggery': Lions Align and Their Mandibles Rock!

PubMed

Williams, Vivienne L; Loveridge, Andrew J; Newton, David J; Macdonald, David W

2015-01-01

South Africa has legally exported substantial quantities of lion bones to Southeast Asia and China since 2008, apparently as part of the multinational trade substituting bones and body parts of other large cats for those of the tiger in wine and other health tonics. The legal sale of lion bones may mask an illegal trade, the size of which is only partially known. An observed component of the illegal trade is that quantities of skeletons are sometimes declared falsely/fraudulently on CITES export permits. Furthermore, there are emerging concerns that bones from tigers reared in captivity in South Africa and elsewhere are being laundered as lion bones using CITES Appendix II permits. There is therefore a need for tools to monitor the trade in lion body parts and to distinguish between lions and tigers. Our research indicates that it is possible to use skeletons, skulls and cranial sutures to detect misdeclarations in the lion bone trade. It is also possible to use the average mass of a lion skeleton to corroborate the numbers of skeletons declared on CITES permits, relative to the weight of the consolidated consignments stated on the air waybills. When the mass of consolidated consignments of skeletons destined for export was regressed against the number of skeletons in that consignment, there was a strong correlation between the variables (r2 = 0.992) that can be used as a predictor of the accuracy of a declaration on a CITES permit. Additionally, the skulls of lions and tigers differ: two cranial sutures of lions align and their mandibles rock when placed on a flat surface, whereas the cranial sutures of tigers are not aligned and their mandibles rest naturally on two contact points. These two morphological differences between the skulls of tigers and lions are easy to observe at a glance and provide a method for distinguishing between the species if illegal trade in the bones is suspected and the skulls are present. These identifications should ideally be confirmed by a DNA test to provide rigorous evidence to prosecute offenders violating CITES regulations.

The export premium: why some logs are worth more abroad.

Treesearch

Donald F. Flora; Wendy J. McGinnis; Christine L. Lane

1993-01-01

For as long as logs have been exported from the Pacific Northwest, they seem to have been worth more offshore than in the domestic market. Five reasons for the export premium are the inconvenience of trade, quality, extra "haul and hassle," continuity in export arrangements, and export embargoes. A large and increasing differential remains between export and...

7 CFR 6.32 - Globalization of licenses.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Agriculture Office of the Secretary of Agriculture IMPORT QUOTAS AND FEES Dairy Tariff-Rate Import Quota... Trade Representative, the applicable licensees to enter the remaining balance or a portion thereof from... consent for such an adjustment of licenses from the government of the exporting country for quantities in...

Identifying Perceived Benefits and Disadvantages of Restoration Adoption in an Urbanizing Watershed

EPA Science Inventory

Degraded urban streams are not only characterized by poor local water quality and quantity, but also can export excess nutrients and sediments to sensitive downstream estuarine systems. Restoration of wetlands and riparian areas is one of a suite of “green infrastructure” practic...

7 CFR 1493.430 - Application for a payment guarantee.

Code of Federal Regulations, 2010 CFR

2010-01-01

... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Supplier Credit Guarantee Program Operations § 1493.430 Application for a payment guarantee... request for CCC to reserve coverage up to the maximum quantity permitted by the contract loading tolerance...

7 CFR 1493.430 - Application for a payment guarantee.

Code of Federal Regulations, 2011 CFR

2011-01-01

... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Supplier Credit Guarantee Program Operations § 1493.430 Application for a payment guarantee... request for CCC to reserve coverage up to the maximum quantity permitted by the contract loading tolerance...

Non-FG mediated transport of the large pre-ribosomal subunit through the nuclear pore complex by the mRNA export factor Gle2

PubMed Central

Occhipinti, Laura; Chang, Yiming; Altvater, Martin; Menet, Anna M.; Kemmler, Stefan; Panse, Vikram G.

2013-01-01

Multiple export receptors passage bound pre-ribosomes through nuclear pore complexes (NPCs) by transiently interacting with the Phe-Gly (FG) meshwork of their transport channels. Here, we reveal how the non-FG interacting yeast mRNA export factor Gly-Leu-FG lethal 2 (Gle2) functions in the export of the large pre-ribosomal subunit (pre-60S). Structure-guided studies uncovered conserved platforms used by Gle2 to export pre-60S: an uncharacterized basic patch required to bind pre-60S, and a second surface that makes non-FG contacts with the nucleoporin Nup116. A basic patch mutant of Gle2 is able to function in mRNA export, but not pre-60S export. Thus, Gle2 provides a distinct interaction platform to transport pre-60S to the cytoplasm. Notably, Gle2’s interaction platforms become crucial for pre-60S export when FG-interacting receptors are either not recruited to pre-60S or are impaired. We propose that large complex cargos rely on non-FG as well as FG-interactions for their efficient translocation through the nuclear pore complex channel. PMID:23907389

77 FR 2302 - Agency Information Collection Activities; Proposed Collection; Comment Request; Antimicrobial...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-17

... and quantities exported; and (3) a listing of the target animals, indications, and production classes... Number Firm Name Dosage Form(s) Production Class(es) Animal Species--Food Animal or Food and Non-Food...] Agency Information Collection Activities; Proposed Collection; Comment Request; Antimicrobial Animal Drug...

40 CFR 747.115 - Mixed mono and diamides of an organic acid.

Code of Federal Regulations, 2010 CFR

2010-07-01

... warning statement shall be no smaller than six point type. All required label text shall be of sufficient..., commerce, importer, impurity, Inventory, manufacturer, person, process, processor, and small quantities... control of the processor. (ii) Distribution in commerce is limited to purposes of export. (iii) The...

15 CFR 750.7 - Issuance of licenses.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... After a license application is approved, a computer generated license is issued by the Department of... technology, commodities will be approved with a quantity or dollar value limit. The “Unit” paragraph within... is related to a multi-year project, when production lead time will not permit an export or reexport...

South Texas Maquiladora Suppliers Project.

ERIC Educational Resources Information Center

Patrick, J. Michael

This project was undertaken to assist South Texas industries in improving export to nearby Mexican maquiladoras (factories). The maquiladora program is based on co-production by two plants under a single management, one on each side of the border. Activities addressed four objectives: (1) to determine the dollar value, quantity, and source of the…

75 FR 75955 - Notice of Request for Extension and Revision of a Currently Approved Information Collection for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-07

... Governing Inspection and Certification of Processed Fruits and Vegetables and Related Products AGENCY...: ``Regulations Governing Inspection and Certification of Processed Fruits and Vegetables and Related Products--7..., certifications of quantity and quality, import product inspections, and export certification. Affected public may...

Structural adjustment and drought in Zambia.

PubMed

Mulwanda, M

1995-06-01

While drought is not uncommon in Zambia, the country is now facing the worst drought in history. The monetary and social costs will be enormous. Although it is too early to measure the economic and social costs of the drought on Zambia, it is obvious that the impact is catastrophic on a country whose economy is under pressure. The drought will affect the structural adjustment programme (SAP) unveiled by the new government which has embraced the market economy. The country has imported, and will continue to import, large quantities of maize and other foodstuffs, a situation likely to strain the balance of payments. Earlier targets with regard to export earnings, reductions in the budget deficit, and GDP growth as contained in the Policy Framework Paper (PFP) are no longer attainable due to the effects of the drought.

Analysis of the characteristics of the global virtual water trade network using degree and eigenvector centrality, with a focus on food and feed crops

NASA Astrophysics Data System (ADS)

Lee, Sang-Hyun; Mohtar, Rabi H.; Choi, Jin-Yong; Yoo, Seung-Hwan

2016-10-01

This study aims to analyze the characteristics of global virtual water trade (GVWT), such as the connectivity of each trader, vulnerable importers, and influential countries, using degree and eigenvector centrality during the period 2006-2010. The degree centrality was used to measure the connectivity, and eigenvector centrality was used to measure the influence on the entire GVWT network. Mexico, Egypt, China, the Republic of Korea, and Japan were classified as vulnerable importers, because they imported large quantities of virtual water with low connectivity. In particular, Egypt had a 15.3 Gm3 year-1 blue water saving effect through GVWT: the vulnerable structure could cause a water shortage problem for the importer. The entire GVWT network could be changed by a few countries, termed "influential traders". We used eigenvector centrality to identify those influential traders. In GVWT for food crops, the USA, Russian Federation, Thailand, and Canada had high eigenvector centrality with large volumes of green water trade. In the case of blue water trade, western Asia, Pakistan, and India had high eigenvector centrality. For feed crops, the green water trade in the USA, Brazil, and Argentina was the most influential. However, Argentina and Pakistan used high proportions of internal water resources for virtual water export (32.9 and 25.1 %); thus other traders should carefully consider water resource management in these exporters.

Worse than imagined: Unidentified virtual water flows in China.

PubMed

Cai, Beiming; Wang, Chencheng; Zhang, Bing

2017-07-01

The impact of virtual water flows on regional water scarcity in China had been deeply discussed in previous research. However, these studies only focused on water quantity, the impact of virtual water flows on water quality has been largely neglected. In this study, we incorporate the blue water footprint related with water quantity and grey water footprint related with water quality into virtual water flow analysis based on the multiregional input-output model of 2007. The results find that the interprovincial virtual flows accounts for 23.4% of China's water footprint. The virtual grey water flows are 8.65 times greater than the virtual blue water flows; the virtual blue water and grey water flows are 91.8 and 794.6 Gm 3 /y, respectively. The use of the indicators related with water quantity to represent virtual water flows in previous studies will underestimate their impact on water resources. In addition, the virtual water flows are mainly derived from agriculture, chemical industry and petroleum processing and the coking industry, which account for 66.8%, 7.1% and 6.2% of the total virtual water flows, respectively. Virtual water flows have intensified both quantity- and quality-induced water scarcity of export regions, where low-value-added but water-intensive and high-pollution goods are produced. Our study on virtual water flows can inform effective water use policy for both water resources and water pollution in China. Our methodology about virtual water flows also can be used in global scale or other countries if data available. Copyright © 2017 Elsevier Ltd. All rights reserved.

Utilizing chromophoric dissolved organic matter measurements to derive export and reactivity of dissolved organic carbon exported to the Arctic Ocean: A case study of the Yukon River, Alaska

USGS Publications Warehouse

Spencer, R.G.M.; Aiken, G.R.; Butler, K.D.; Dornblaser, M.M.; Striegl, Robert G.; Hernes, P.J.

2009-01-01

The quality and quantity of dissolved organic matter (DOM) exported by Arctic rivers is known to vary with hydrology and this exported material plays a fundamental role in the biogeochemical cycling of carbon at high latitudes. We highlight the potential of optical measurements to examine DOM quality across the hydrograph in Arctic rivers. Furthermore, we establish chromophoric DOM (CDOM) relationships to dissolved organic carbon (DOC) and lignin phenols in the Yukon River and model DOC and lignin loads from CDOM measurements, the former in excellent agreement with long-term DOC monitoring data. Intensive sampling across the historically under-sampled spring flush period highlights the importance of this time for total export of DOC and particularly lignin. Calculated riverine DOC loads to the Arctic Ocean show an increase from previous estimates, especially when new higher discharge data are incorporated. Increased DOC loads indicate decreased residence times for terrigenous DOM in the Arctic Ocean with important implications for the reactivity and export of this material to the Atlantic Ocean. Citation: Spencer, R. G. M., G. R. Aiken, K. D. Butler, M. M. Dornblaser, R. G. Striegl, and P. J. Hernes (2009), Utilizing chromophoric dissolved organic matter measurements to derive export and reactivity of dissolved organic carbon exported to the Arctic Ocean: A case study of the Yukon River, Alaska, Geophys. Res. Lett., 36, L06401, doi:10.1029/ 2008GL036831. Copyright 2009 by the American Geophysical Union.

Small phytoplankton and carbon export from the surface ocean.

PubMed

Richardson, Tammi L; Jackson, George A

2007-02-09

Autotrophic picoplankton dominate primary production over large oceanic regions but are believed to contribute relatively little to carbon export from surface layers. Using analyses of data from the equatorial Pacific Ocean and Arabian Sea, we show that the relative direct and indirect contribution of picoplankton to export is proportional to their total net primary production, despite their small size. We suggest that all primary producers, not just the large cells, can contribute to export from the surface layer of the ocean at rates proportional to their production rates.

The Great Irish Famine. 2nd Edition.

ERIC Educational Resources Information Center

Mullin, James

Between 1845 and 1850, more than a million Irish starved to death while massive quantities of food were being exported from their country. A half million were evicted from their homes during the potato blight. A million and a half emigrated to the United States, Britain, and Australia, often on board rotting, overcrowded "coffin ships."…

7 CFR 33.12 - Apples not subject to regulation.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Apples not subject to regulation. 33.12 Section 33.12... REGULATIONS REGULATIONS ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Exemptions § 33.12 Apples not subject... this part, transport or receive for transportation to any foreign destination: (a) A quantity of apples...

7 CFR 33.12 - Apples not subject to regulation.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Apples not subject to regulation. 33.12 Section 33.12... REGULATIONS REGULATIONS ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Exemptions § 33.12 Apples not subject... this part, transport or receive for transportation to any foreign destination: (a) A quantity of apples...

7 CFR 33.12 - Apples not subject to regulation.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Apples not subject to regulation. 33.12 Section 33.12... REGULATIONS REGULATIONS ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Exemptions § 33.12 Apples not subject... this part, transport or receive for transportation to any foreign destination: (a) A quantity of apples...

7 CFR 33.12 - Apples not subject to regulation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Apples not subject to regulation. 33.12 Section 33.12... REGULATIONS REGULATIONS ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Exemptions § 33.12 Apples not subject... this part, transport or receive for transportation to any foreign destination: (a) A quantity of apples...

7 CFR 33.12 - Apples not subject to regulation.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Apples not subject to regulation. 33.12 Section 33.12... REGULATIONS REGULATIONS ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Exemptions § 33.12 Apples not subject... this part, transport or receive for transportation to any foreign destination: (a) A quantity of apples...

7 CFR 6.22 - Requirement for a license.

Code of Federal Regulations, 2010 CFR

2010-01-01

... obtained prior to entry, and the importer of record (or a broker or agent acting on its behalf) shall... documentation identifying the article, quantity to be imported, its location, intended use, an entry number and... article be destroyed or re-exported after such use; or (4) Such person pays the applicable over-quota rate...

7 CFR 6.22 - Requirement for a license.

Code of Federal Regulations, 2012 CFR

2012-01-01

... obtained prior to entry, and the importer of record (or a broker or agent acting on its behalf) shall... documentation identifying the article, quantity to be imported, its location, intended use, an entry number and... article be destroyed or re-exported after such use; or (4) Such person pays the applicable over-quota rate...

7 CFR 6.22 - Requirement for a license.

Code of Federal Regulations, 2014 CFR

2014-01-01

... obtained prior to entry, and the importer of record (or a broker or agent acting on its behalf) shall... documentation identifying the article, quantity to be imported, its location, intended use, an entry number and... article be destroyed or re-exported after such use; or (4) Such person pays the applicable over-quota rate...

7 CFR 6.22 - Requirement for a license.

Code of Federal Regulations, 2011 CFR

2011-01-01

... obtained prior to entry, and the importer of record (or a broker or agent acting on its behalf) shall... documentation identifying the article, quantity to be imported, its location, intended use, an entry number and... article be destroyed or re-exported after such use; or (4) Such person pays the applicable over-quota rate...

7 CFR 6.22 - Requirement for a license.

Code of Federal Regulations, 2013 CFR

2013-01-01

... obtained prior to entry, and the importer of record (or a broker or agent acting on its behalf) shall... documentation identifying the article, quantity to be imported, its location, intended use, an entry number and... article be destroyed or re-exported after such use; or (4) Such person pays the applicable over-quota rate...

78 FR 22850 - 36(b)(1) Arms Sales Notification

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-17

... million * As defined in Section 47(6) of the Arms Export Control Act. (iii) Description and Quantity or... software continues to be modified via a pre-planned product improvement (P3I) program in order to improve its counter- countermeasure capabilities. No software source code or algorithms will be released. The...

21 CFR 1313.12 - Requirement of authorization to import.

Code of Federal Regulations, 2012 CFR

2012-04-01

... EXPORTATION OF LIST I AND LIST II CHEMICALS Importation of Listed Chemicals § 1313.12 Requirement of authorization to import. (a) Each regulated person who imports a listed chemical that meets or exceeds the threshold quantities identified in § 1310.04(f) or is a listed chemical for which no threshold has been...

21 CFR 1313.12 - Requirement of authorization to import.

Code of Federal Regulations, 2014 CFR

2014-04-01

... EXPORTATION OF LIST I AND LIST II CHEMICALS Importation of Listed Chemicals § 1313.12 Requirement of authorization to import. (a) Each regulated person who imports a listed chemical that meets or exceeds the threshold quantities identified in § 1310.04(f) or is a listed chemical for which no threshold has been...

21 CFR 1313.12 - Requirement of authorization to import.

Code of Federal Regulations, 2013 CFR

2013-04-01

... EXPORTATION OF LIST I AND LIST II CHEMICALS Importation of Listed Chemicals § 1313.12 Requirement of authorization to import. (a) Each regulated person who imports a listed chemical that meets or exceeds the threshold quantities identified in § 1310.04(f) or is a listed chemical for which no threshold has been...

The rare-earth elements: Vital to modern technologies and lifestyles

USGS Publications Warehouse

Van Gosen, Bradley S.; Verplanck, Philip L.; Long, Keith R.; Gambogi, Joseph; Seal, Robert R.

2014-01-01

Until recently, the rare-earth elements (REEs) were familiar to a relatively small number of people, such as chemists, geologists, specialized materials scientists, and engineers. In the 21st century, the REEs have gained visibility through many media outlets because of (1) the public has recognized the critical, specialized properties that REEs contribute to modern technology, as well as (2) China's dominance in production and supply of the REEs and (3) international dependence on China for the majority of the world's REE supply.Since the late 1990s, China has provided 85–95 percent of the world’s REEs. In 2010, China announced their intention to reduce REE exports. During this timeframe, REE use increased substantially. REEs are used as components in high technology devices, including smart phones, digital cameras, computer hard disks, fluorescent and light-emitting-diode (LED) lights, flat screen televisions, computer monitors, and electronic displays. Large quantities of some REEs are used in clean energy and defense technologies. Because of the many important uses of REEs, nations dependent on new technologies, such as Japan, the United States, and members of the European Union, reacted with great concern to China’s intent to reduce its REE exports. Consequently, exploration activities intent on discovering economic deposits of REEs and bringing them into production have increased.

Virtual industrial water usage and wastewater generation in the Middle East/North African region

NASA Astrophysics Data System (ADS)

Sakhel, S. R.; Geissen, S.-U.; Vogelpohl, A.

2013-01-01

This study deals with the quantification of volumes of water usage, wastewater generation, virtual water export, and wastewater generation from export for eight export relevant industries present in the Middle East/North Africa (MENA). It shows that about 3400 million m3 of water is used per annum while around 793 million m3 of wastewater is generated from products that are meant for domestic consumption and export. The difference between volumes of water usage and wastewater generation is due to water evaporation or injecting underground (oil wells pressure maintenance). The wastewater volume generated from production represents a population equivalent of 15.5 million in terms of wastewater quantity and 30.4 million in terms of BOD. About 409 million m3 of virtual water flows from MENA to EU27 (resulting from export of eight commodities) which is equivalent to 12.1% of the water usage of those industries and Libya is the largest virtual water exporter (about 87 million m3). Crude oil and refined petroleum products represent about 89% of the total virtual water flow, fertilizers represent around 10% and 1% remaining industries. EU27 poses the greatest indirect pressure on the Kuwaiti hydrological system where the virtual water export represents about 96% of the actual renewable water resources in this country. The Kuwaiti crude oil water use in relation to domestic water withdrawal is about 89% which is highest among MENA countries. Pollution of water bodies, in terms of BOD, due to production is very relevant for crude oil, slaughterhouses, refineries, olive oil, and tanneries while pollution due to export to EU27 is most relevant for crude oil industry and olive oil mills.

27 CFR 28.250 - Bills of lading required.

Code of Federal Regulations, 2010 CFR

2010-04-01

... wines, for deposit in a foreign-trade zone, with benefit of drawback, and the principal has filed bond... denatured spirits, and wines: (1) The name of the exporter (if different from the shipper), (2) The name and... the case may be, and (5) The total quantity in wine gallons or liters, (b) As to beer: (1) The name of...

40 CFR 761.80 - Manufacturing, processing and distribution in commerce exemptions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 16823-0048 (PDE-41.2). (6) Radian Corp., Austin, TX 78766 (PDE-182.1). (7) Restek Corporation... petitioner(s) an exemption for 1 year to export PCBs for use in small quantities for research and development: (1) Accu-Standard, New Haven, CT. 06503. (2) ManTech, Research Triangle Park, NC 27709. (d) The...

40 CFR 761.80 - Manufacturing, processing and distribution in commerce exemptions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 16823-0048 (PDE-41.2). (6) Radian Corp., Austin, TX 78766 (PDE-182.1). (7) Restek Corporation... petitioner(s) an exemption for 1 year to export PCBs for use in small quantities for research and development: (1) Accu-Standard, New Haven, CT. 06503. (2) ManTech, Research Triangle Park, NC 27709. (d) The...

40 CFR 761.80 - Manufacturing, processing and distribution in commerce exemptions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 16823-0048 (PDE-41.2). (6) Radian Corp., Austin, TX 78766 (PDE-182.1). (7) Restek Corporation... petitioner(s) an exemption for 1 year to export PCBs for use in small quantities for research and development: (1) Accu-Standard, New Haven, CT. 06503. (2) ManTech, Research Triangle Park, NC 27709. (d) The...

40 CFR 761.80 - Manufacturing, processing and distribution in commerce exemptions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 16823-0048 (PDE-41.2). (6) Radian Corp., Austin, TX 78766 (PDE-182.1). (7) Restek Corporation... petitioner(s) an exemption for 1 year to export PCBs for use in small quantities for research and development: (1) Accu-Standard, New Haven, CT. 06503. (2) ManTech, Research Triangle Park, NC 27709. (d) The...

40 CFR 761.80 - Manufacturing, processing and distribution in commerce exemptions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 16823-0048 (PDE-41.2). (6) Radian Corp., Austin, TX 78766 (PDE-182.1). (7) Restek Corporation... petitioner(s) an exemption for 1 year to export PCBs for use in small quantities for research and development: (1) Accu-Standard, New Haven, CT. 06503. (2) ManTech, Research Triangle Park, NC 27709. (d) The...

19 CFR 158.4 - Liability of carrier for lost or missing packages.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 19 Customs Duties 2 2012-04-01 2012-04-01 false Liability of carrier for lost or missing packages... EXPORTED Lost or Missing Packages and Deficiencies in Contents of Packages § 158.4 Liability of carrier for lost or missing packages. Upon a joint determination or independent determination of quantity as set...

19 CFR 158.4 - Liability of carrier for lost or missing packages.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 19 Customs Duties 2 2013-04-01 2013-04-01 false Liability of carrier for lost or missing packages... EXPORTED Lost or Missing Packages and Deficiencies in Contents of Packages § 158.4 Liability of carrier for lost or missing packages. Upon a joint determination or independent determination of quantity as set...

19 CFR 158.4 - Liability of carrier for lost or missing packages.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 2 2011-04-01 2011-04-01 false Liability of carrier for lost or missing packages... EXPORTED Lost or Missing Packages and Deficiencies in Contents of Packages § 158.4 Liability of carrier for lost or missing packages. Upon a joint determination or independent determination of quantity as set...

19 CFR 158.4 - Liability of carrier for lost or missing packages.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 19 Customs Duties 2 2014-04-01 2014-04-01 false Liability of carrier for lost or missing packages... EXPORTED Lost or Missing Packages and Deficiencies in Contents of Packages § 158.4 Liability of carrier for lost or missing packages. Upon a joint determination or independent determination of quantity as set...

19 CFR 158.4 - Liability of carrier for lost or missing packages.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false Liability of carrier for lost or missing packages... EXPORTED Lost or Missing Packages and Deficiencies in Contents of Packages § 158.4 Liability of carrier for lost or missing packages. Upon a joint determination or independent determination of quantity as set...

40 CFR 82.4 - Prohibitions for class I controlled substances.

Code of Federal Regulations, 2012 CFR

2012-07-01

... not listed as a Party to the 1987 Montreal Protocol unless that foreign state is complying with the 1987 Montreal Protocol (See appendix C, annex 2 of this subpart); (2) Import or export any quantity of... to this subpart, from any foreign state not Party to the 1987 Montreal Protocol (as noted in appendix...

40 CFR 82.4 - Prohibitions for class I controlled substances.

Code of Federal Regulations, 2013 CFR

2013-07-01

... not listed as a Party to the 1987 Montreal Protocol unless that foreign state is complying with the 1987 Montreal Protocol (See appendix C, annex 2 of this subpart); (2) Import or export any quantity of... to this subpart, from any foreign state not Party to the 1987 Montreal Protocol (as noted in appendix...

76 FR 9542 - Stainless Steel Sheet and Strip in Coils From Mexico; Notice of Amended Final Results of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-18

... investigation; and (4) the cash deposit rate for all non-Mexican exporters will be the rate applicable to the...-unit cost of production and per-unit packing expenses by the quantity sold. See Mexinox Ministerial.... indirect selling expenses. Specifically, Mexinox contends that the Department a) failed to include ``other...

Economic Value of Army Foreign Military Sales

DTIC Science & Technology

2015-12-01

12 2. Direct Commercial Sales vs. Foreign Military Sales ............... 15 3. GAO and CBO Reports... Directive DOS Department of State DSCA Defense Security Cooperation Agency EOQ Economic Order Quantity FAA Foreign Assistance Act FAR Federal...and approves export license requests for Direct Commercial Sales (DCS) of defense articles (DSCA, 2012, p. C1.3.1). The DSCA summarizes the FMS

7 CFR 20.6 - Submission of reports.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 1 2013-01-01 2013-01-01 false Submission of reports. 20.6 Section 20.6 Agriculture Office of the Secretary of Agriculture EXPORT SALES REPORTING REQUIREMENTS § 20.6 Submission of reports... provides for a range in quantity (e.g. 10,000 metric tons to 12,000 metric tons with or without a loading...

7 CFR 20.6 - Submission of reports.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 1 2011-01-01 2011-01-01 false Submission of reports. 20.6 Section 20.6 Agriculture Office of the Secretary of Agriculture EXPORT SALES REPORTING REQUIREMENTS § 20.6 Submission of reports... provides for a range in quantity (e.g. 10,000 metric tons to 12,000 metric tons with or without a loading...

7 CFR 20.6 - Submission of reports.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 1 2014-01-01 2014-01-01 false Submission of reports. 20.6 Section 20.6 Agriculture Office of the Secretary of Agriculture EXPORT SALES REPORTING REQUIREMENTS § 20.6 Submission of reports... provides for a range in quantity (e.g. 10,000 metric tons to 12,000 metric tons with or without a loading...

7 CFR 20.6 - Submission of reports.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 1 2012-01-01 2012-01-01 false Submission of reports. 20.6 Section 20.6 Agriculture Office of the Secretary of Agriculture EXPORT SALES REPORTING REQUIREMENTS § 20.6 Submission of reports... provides for a range in quantity (e.g. 10,000 metric tons to 12,000 metric tons with or without a loading...

Stream-water chemistry, nutrients, and pesticides in Town Brook, a headwater stream of the Cannonsville Reservoir Watershed, Delaware County, New York, 1999

USGS Publications Warehouse

McHale, Michael R.; Phillips, Patrick J.

2001-01-01

Stream-water chemistry was monitored from January 1 through December 31, 1999, in the Town Brook watershed (TBW) in Delaware County, N.Y. to provide a basis for future evaluation of the effectiveness of Best Management Practices (BMPs) in decreasing agricultural nutrient and pesticide leaching to receiving waters. Total runoff from the watershed during 1999 was 664 millimeters (mm). Annual nutrient export (in kilograms per hectare) values were: ammonia (NH3), 0.25; nitrate (NO3-), 4.3; total nitrogen (TN), 10.6; orthophosphate (OP), 0.26; total dissolved phosphorus (TDP), 0.30; and total phosphorus (TP), 1.2 during 1999. Streamwater samples were collected during baseflow, elevated baseflow, and stormflow conditions. Stormflow, which produced the greatest flowweighted mean nutrient concentrations, represented only 41 percent of the annual runoff but accounted from 49 to 68 percent of the annual nutrient export. The highest seasonal flow-weighted mean concentrations were measured during the summer; the highest concentrations occurred during a large storm on July 4, 1999 with a recurrence interval greater than 100 years. The greatest seasonal export of dissolved nutrients (NH3, NO3-, OP, and TDP) occurred during the winter, whereas the greatest export of TN and TP was during the summer. Most of the TN and TP export during the summer occurred during the July 4 storm. That storm, together with a second large storm on September 16, 1999, accounted for the following percentages of annual export: ammonia, 17 percent; NO3-, 21 percent; TN, 45 percent; OP, 21 percent; TDP, 21 percent; and TP, 56 percent. Although these results provide information on the quantity and timing of nutrient export, they do not indicate the nutrient source nor the transport mechanisms by which nutrients are delivered to the stream.Baseflow and stormflow samples were collected for pesticide analyses at the Town Brook watershed outlet from January through July 1999. Eight pesticides and pesticide metabolites (degradation products) were detected in the samples. Four compounds (metolachlor, atrazine, metolachlor ESA, and metolachlor OA) were detected in concentrations greater than 1 micrograms per liter (μg/L) in one or more samples. Two of these compounds.the herbicide metabolites metalochlor ESA and metalochlor OA.were detected in concentrations higher than those of the parent compound metolachlor. Only one sample, collected during the July 4 storm, exceeded New York State surface-water-quality standards for any pesticide (simazine); its concentration of 0.53 μg/L was 0.03 μg/L higher than the New York State standard (0.50 μg/L). No concentrations exceeded Federal water-quality standards. Pesticide and metabolite concentrations were as much as 25 times greater during stormflow than during baseflow. Stormflow pesticide concentrations were indicative of a spring 'flushing', in which stream pesticide concentrations are elevated from concentrations typical during the rest of the year during the first few storms after pesticide application. Pesticides and pesticide metabolites were detected in all stormflow samples. These results illustrate the need to include baseflow and stormflow in pesticide sampling routines.The results of this study emphasize the need for (1) baseflow and stormflow sampling to capture the range of nutrient and pesticide concentrations from agricultural watersheds, and (2) research to define the mechanisms of nutrient and pesticide export in agriculutral watersheds.

Determining hillslope-channel connectivity in an agricultural catchment using rare-earth oxide tracers and random forests.

NASA Astrophysics Data System (ADS)

Masselink, Rens; Temme, Arnaud; Giménez, Rafael; Casalí, Javier; Keesstra, Saskia

2017-04-01

Soil erosion from agricultural areas is a large problem, because of off-site effects like the rapid filling of reservoirs. To mitigate the problem of sediments from agricultural areas reaching the channel, reservoirs and other surface waters, it is important to understand hillslope-channel connectivity and catchment connectivity. To determine the functioning of hillslope-channel connectivity and the continuation of transport of these sediments in the channel, it is necessary to obtain data on sediment transport from the hillslopes to the channels. Simultaneously, the factors that influence sediment export out of the catchment need to be studied. For measuring hillslope-channel sediment connectivity, Rare-Earth Oxide (REO) tracers were applied to a hillslope in an agricultural catchment in Navarre, Spain, preceding the winter of 2014-2015. The results showed that during the winter there was no sediment transport from the hillslope to the channel. Analysis of precipitation data showed that total precipitation quantities did not differ much from the mean. However, precipitation intensities were low, causing little sediment mobilisation. To test the implication of the REO results at the catchment scale, two conceptual models for sediment connectivity were assessed using a Random Forest (RF) machine learning method. One model proposes that small events provide sediment for large events, while the other proposes that only large events cause sediment detachment and small events subsequently remove these sediments from near and in the channel. The RF method was applied to a daily dataset of sediment yield from the catchment (N=2451 days), and two subsets of the whole dataset: small events (N=2319) and large events (N=132). For sediment yield prediction of small events, variables related to large preceding events were the most important. The model for large events underperformed and, therefore, we could not draw any immediate conclusions whether small events influence the amount of sediment exported during large events. Both REO tracers and RF method showed that low intensity events do not contribute any sediments to the channel in the Latxaga catchment (cf. Masselink et al., 2016). Sediment dynamics are dominated by sediment mobilisation during large (high intensity) events. Sediments are for a large part exported during those events, but large amount of sediments are deposited in and near the channel after these events. These sediments are gradually removed by small events. To better understand the delivery of sediments to the channel and how large and small events influence each other more field data on hillslope-channel connectivity and within-channel sediment dynamics is necessary. Reference: Masselink, R.J.H., Keesstra, S.D., Temme, A.J.A.M., Seeger, M., Giménez, R., Casalí, J., 2016. Modelling Discharge and Sediment Yield at Catchment Scale Using Connectivity Components. Land Degrad. Dev. 27, 933-945. doi:10.1002/ldr.2512

Analyzing the impacts of final demand changes on total output using input-output approach: The case of Japanese ICT sectors

NASA Astrophysics Data System (ADS)

Zuhdi, Ubaidillah

2014-03-01

The purpose of this study is to analyze the impacts of final demand changes on total output of Japanese Information and Communication Technologies (ICT) sectors in future time. This study employs one of analysis tool in Input-Output (IO) analysis, demand-pull IO quantity model, in achieving the purpose. There are three final demand changes used in this study, namely (1) export, (2) import, and (3) outside households consumption changes. This study focuses on "pure change" condition, the condition that final demand changes only appear in analyzed sectors. The results show that export and outside households consumption modifications give positive impact while opposite impact could be seen in import change.

Potential ramifications of the global economic crisis on human-mediated dispersal of marine non-indigenous species.

PubMed

Floerl, Oliver; Coutts, Ashley

2009-11-01

The global economy is currently experiencing one of its biggest contractions on record. A sharp decline in global imports and exports since 2008 has affected global merchant vessel traffic, the principal mode of bulk commodity transport around the world. During the first quarter of 2009, 10% and 25% of global container and refrigerated vessels, respectively, were reported to be unemployed. A large proportion of these vessels are lying idle at anchor in the coastal waters of South East Asia, sometimes for periods of greater than 3 months. Whilst at anchor, the hulls of such vessels will develop diverse and extensive assemblages of marine biofouling species. Once back in service, these vessels are at risk of transporting higher-than-normal quantities of marine organisms between their respective global trading ports. We discuss the potential ramifications of the global economic crisis on the spread of marine non-indigenous species via global commercial shipping.

System simulation application for determining the size of daily raw material purchases at PT XY

NASA Astrophysics Data System (ADS)

Napitupulu, H. L.

2018-02-01

Every manufacturing company needs to implement green production, including PT XY as a marine catchment processing industry in Sumatera Utara Province. The company is engaged in the processing of squid for export purposes. The company’s problem relates to the absence of a decision on the daily purchase amount of the squid. The purchase of daily raw materials in varying quantities has caused companies to face the problem of excess raw materials or otherwise the lack of raw materials. The low purchase of raw materials will result in reduced productivity, while large purchases will lead to increased cooling costs for storage of excess raw materials, as well as possible loss of damage raw material. Therefore it is necessary to determine the optimal amount of raw material purchases every day. This can be determined by applying simulation. Application of system simulations can provide the expected optimal amount of raw material purchases.

Interannual kinetics (2010-2013) of large wood in a river corridor exposed to a 50-year flood event and fluvial ice dynamics

NASA Astrophysics Data System (ADS)

Boivin, Maxime; Buffin-Bélanger, Thomas; Piégay, Hervé

2017-02-01

Semi-alluvial rivers of the Gaspé Peninsula, Québec, are prone to produce and transport vast quantities of large wood (LW). The high rate of lateral erosion owing to high energy flows and noncohesive banks is the main process leading to the recruitment of large wood, which in turn initiates complex patterns of wood accumulation and reentrainment within the active channel. The delta of the Saint-Jean River (SJR) has accumulated large annual wood fluxes since 1960 that culminated in a wood raft of > 3-km in length in 2014. To document the kinetics of large wood on the main channel of SJR, four annual surveys were carried out from 2010 to 2013 to locate and describe > 1000 large wood jams (LWJ) and 2000 large wood individuals (LWI) along a 60-km river section. Airborne and ground photo/video images were used to estimate the wood volume introduced by lateral erosion and to identify local geomorphic conditions that control wood mobility and deposits. Video camera analysis allowed the examination of transport rates from three hydrometeorological events for specific river sections. Results indicate that the volume of LW recruited between 2010 and 2013 represents 57% of the total LW production over the 2004-2013 period. Volumes of wood deposited along the 60-km section were four times higher in 2013 than in 2010. Increases in wood amount occurred mainly in upper alluvial sections of the river, whereas decreases were observed in the semi-alluvial middle sections. Observations suggest that the 50-year flood event of 2010 produced large amounts of LW that were only partly exported out of the basin so that a significant amount was still available for subsequent floods. Large wood storage continued after this flood until a similar flood or an ice-breakup event could remobilise these LW accumulations into the river corridor. Ice-jam floods transport large amounts of wood during events with fairly low flow but do not contribute significantly to recruitment rates (ca. 10 to 30% early). It is fairly probable that the wood export peak observed in 2012 at the river mouth, where no flood occurred and which is similar to the 1-in 10-year flood of 2010, is mainly linked to such ice-break events that occurred in March 2012.

Nmd3p Is a Crm1p-Dependent Adapter Protein for Nuclear Export of the Large Ribosomal Subunit

PubMed Central

Ho, Jennifer Hei-Ngam; Kallstrom, George; Johnson, Arlen W.

2000-01-01

In eukaryotic cells, nuclear export of nascent ribosomal subunits through the nuclear pore complex depends on the small GTPase Ran. However, neither the nuclear export signals (NESs) for the ribosomal subunits nor the receptor proteins, which recognize the NESs and mediate export of the subunits, have been identified. We showed previously that Nmd3p is an essential protein from yeast that is required for a late step in biogenesis of the large (60S) ribosomal subunit. Here, we show that Nmd3p shuttles and that deletion of the NES from Nmd3p leads to nuclear accumulation of the mutant protein, inhibition of the 60S subunit biogenesis, and inhibition of the nuclear export of 60S subunits. Moreover, the 60S subunits that accumulate in the nucleus can be coimmunoprecipitated with the NES-deficient Nmd3p. 60S subunit biogenesis and export of truncated Nmd3p were restored by the addition of an exogenous NES. To identify the export receptor for Nmd3p we show that Nmd3p shuttling and 60S export is blocked by the Crm1p-specific inhibitor leptomycin B. These results identify Crm1p as the receptor for Nmd3p export. Thus, export of the 60S subunit is mediated by the adapter protein Nmd3p in a Crm1p-dependent pathway. PMID:11086007

Regulation of the Expression of Bacterial Multidrug Exporters by Two-Component Signal Transduction Systems.

PubMed

Nishino, Kunihiko

2018-01-01

Bacterial multidrug exporters confer resistance to a wide range of antibiotics, dyes, and biocides. Recent studies have shown that there are many multidrug exporters encoded in bacterial genome. For example, it was experimentally identified that E. coli has at least 20 multidrug exporters. Because many of these multidrug exporters have overlapping substrate spectra, it is intriguing that bacteria, with their economically organized genomes, harbor such large sets of multidrug exporter genes. The key to understanding how bacteria utilize these multiple exporters lies in the regulation of exporter expression. Bacteria have developed signaling systems for eliciting a variety of adaptive responses to their environments. These adaptive responses are often mediated by two-component regulatory systems. In this chapter, the method to identify response regulators that affect expression of multidrug exporters is described.

Rapid Recovery of a Gully Thermokarst: 10 Years of Observation of the Toolik River Thermokarst, North Slope, Alaska

NASA Astrophysics Data System (ADS)

Bowden, W. B.; Gooseff, M. N.; Stuckey, J. J.; Fulweber, R. A.; Larouche, J. R.

2014-12-01

As permafrost thaws, previously frozen soils may become unstable and subside, in some cases forming thermo-erosional features such as gully thermokarst (GTKs). The formation of these features can result in sediment and nutrient inputs to local streams and lakes. The initial evolution of GTKs is rapid (months to several years) and appears to follow a progression in which the loss of ground ice in the soil creates a subsurface cavity that allows for the transport of water downslope, followed by the collapse of the overlying soil into the cavity, with a subsequent period of sediment and nutrient export. However, there is considerable uncertainty about the length of time these features remain unstable and actively transport sediments and nutrients. We followed the evolution of one moderately-sized (~5,000 m2) GTK located in the headwaters of the Toolik River (N68.692733° W149.205433°) on the North Slope of Alaska (USA). This feature formed in July 2003 and we monitored it for several years thereafter. In 2007 we began to monitor the shape and contours of this feature and quantified the level of ecologically important solutes it exports to the local stream. As expected, large quantities of sediment and nutrients were exported from this feature when it first formed. However, within a year or two the sediment export decreased to episodic events and the nutrient export, while elevated above reference levels, was not remarkably high. Between 2007 and the present (2014), the shape and topography of the feature have changed very little (Figure) except for some headwall retrogression, suggesting that long-term sediment transport has decreased dramatically. Thus, the overall sediment loading to the river was smaller and has decreased more rapidly than we expected. The rapid reduction in sediment and nutrient delivery is consistent with the more recent geomorphic evolution and stabilization of this feature. We conclude - contrary to our initial hypotheses - that these features form and stabilize rather quickly (~10 years) and that their influences on local streams and lakes might be ephemeral. Thus, the greater importance of these features may be as indicators of general permafrost degradation in the area and the attendant losses of carbon and other nutrients that this degradation implies.

High export of dissolved silica from the Greenland Ice Sheet

NASA Astrophysics Data System (ADS)

Meire, L.; Meire, P.; Struyf, E.; Krawczyk, D. W.; Arendt, K. E.; Yde, J. C.; Juul Pedersen, T.; Hopwood, M. J.; Rysgaard, S.; Meysman, F. J. R.

2016-09-01

Silica is an essential element for marine life and plays a key role in the biogeochemistry of the ocean. Glacial activity stimulates rock weathering, generating dissolved silica that is exported to coastal areas along with meltwater. The magnitude of the dissolved silica export from large glacial areas such as the Greenland Ice Sheet is presently poorly quantified and not accounted for in global budgets. Here we present data from two fjord systems adjacent to the Greenland Ice Sheet which reveal a large export of dissolved silica by glacial meltwater relative to other macronutrients. Upscaled to the entire Greenland Ice Sheet, the export of dissolved silica equals 22 ± 10 Gmol Si yr-1. When the silicate-rich meltwater mixes with upwelled deep water, either inside or outside Greenland's fjords, primary production takes place at increased silicate to nitrate ratios. This likely stimulates the growth of diatoms relative to other phytoplankton groups.

Urea retranslocation from senescing Arabidopsis leaves is promoted by DUR3-mediated urea retrieval from leaf apoplast

PubMed Central

Bohner, Anne; Kojima, Soichi; Hajirezaei, Mohammad; Melzer, Michael; von Wirén, Nicolaus

2015-01-01

In plants, urea derives either from root uptake or protein degradation. Although large quantities of urea are released during senescence, urea is mainly seen as a short-lived nitrogen (N) catabolite serving urease-mediated hydrolysis to ammonium. Here, we investigated the roles of DUR3 and of urea in N remobilization. During natural leaf senescence urea concentrations and DUR3 transcript levels showed a parallel increase with senescence markers like ORE1 in a plant age- and leaf age-dependent manner. Deletion of DUR3 decreased urea accumulation in leaves, whereas the fraction of urea lost to the leaf apoplast was enhanced. Under natural and N deficiency-induced senescence DUR3 promoter activity was highest in the vasculature, but was also found in surrounding bundle sheath and mesophyll cells. An analysis of petiole exudates from wild-type leaves revealed that N from urea accounted for >13% of amino acid N. Urea export from senescent leaves further increased in ureG-2 deletion mutants lacking urease activity. In the dur3 ureG double insertion line the absence of DUR3 reduced urea export from leaf petioles. These results indicate that urea can serve as an early metabolic marker for leaf senescence, and that DUR3-mediated urea retrieval contributes to the retranslocation of N from urea during leaf senescence. PMID:25440717

Hydrologically mediated iron reduction/oxidation fluctuations and dissolved organic carbon exports in tidal wetlands

NASA Astrophysics Data System (ADS)

Guimond, J. A.; Seyfferth, A.; Michael, H. A.

2017-12-01

Salt marshes are biogeochemical hotspots where large quantities of carbon are processed and stored. High primary productivity and deposition of carbon-laden sediment enable salt marsh soils to accumulate and store organic carbon. Conversely, salt marshes can laterally export carbon from the marsh platform to the tidal channel and eventually the ocean via tidal pumping. However, carbon export studies largely focus on tidal channels, missing key physical and biogeochemical mechanisms driving the mobilization of dissolved organic carbon (DOC) within the marsh platform and limiting our understanding of and ability to predict coastal carbon dynamics. We hypothesize that iron redox dynamics mediate the mobilization/immobilization of DOC in the top 30 cm of salt marsh sediment near tidal channels. The mobilized DOC can then diffuse into the flooded surface water or be advected to tidal channels. To elucidate DOC dynamics driven by iron redox cycles, we measured porewater DOC, Fe(II), total iron, total sulfate, pH, redox potential, and electrical conductivity (EC) beside the creek, at the marsh levee, and in the marsh interior in a mid-latitude tidal salt marsh in Dover, Delaware. Samples were collected at multiple tide stages during a spring and neap tide at depths of 5-75cm. Samples were also collected from the tidal channel. Continuous Eh measurements were made using in-situ electrodes. A prior study shows that DOC and Fe(II) concentrations vary spatially across the marsh. Redox conditions near the creek are affected by tidal oscillations. High tides saturate the soil and decrease redox potential, whereas at low tide, oxygen enters the sediment and increases the Eh. This pattern is always seen in the top 7-10cm of sediment, with more constant low Eh at depth. However, during neap tides, this signal penetrates deeper. Thus, between the creek and marsh levee, hydrology mediates redox conditions. Based on porewater chemistry, if DOC mobilization can be linked to redox cycles, then hydrologic oscillations can be tied to DOC dynamics and predicted with hydrologic models. By elucidating the mechanisms driving the mobilization of DOC, we can begin to better understand, quantify, and forecast coastal carbon dynamics.

Mesoscale Effects on Carbon Export: A Global Perspective

NASA Astrophysics Data System (ADS)

Harrison, Cheryl S.; Long, Matthew C.; Lovenduski, Nicole S.; Moore, Jefferson K.

2018-04-01

Carbon export from the surface to the deep ocean is a primary control on global carbon budgets and is mediated by plankton that are sensitive to physical forcing. Earth system models generally do not resolve ocean mesoscale circulation (O(10-100) km), scales that strongly affect transport of nutrients and plankton. The role of mesoscale circulation in modulating export is evaluated by comparing global ocean simulations conducted at 1° and 0.1° horizontal resolution. Mesoscale resolution produces a small reduction in globally integrated export production (<2%) however, the impact on local export production can be large (±50%), with compensating effects in different ocean basins. With mesoscale resolution, improved representation of coastal jets block off-shelf transport, leading to lower export in regions where shelf-derived nutrients fuel production. Export is further reduced in these regions by resolution of mesoscale turbulence, which restricts the spatial area of production. Maximum mixed layer depths are narrower and deeper across the Subantarctic at higher resolution, driving locally stronger nutrient entrainment and enhanced summer export production. In energetic regions with seasonal blooms, such as the Subantarctic and North Pacific, internally generated mesoscale variability drives substantial interannual variation in local export production. These results suggest that biogeochemical tracer dynamics show different sensitivities to transport biases than temperature and salinity, which should be considered in the formulation and validation of physical parameterizations. Efforts to compare estimates of export production from observations and models should account for large variability in space and time expected for regions strongly affected by mesoscale circulation.

Environmental factor(tm) system: RCRA hazardous waste handler information (on CD-ROM). Data file

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-11-01

Environmental Factor(trademark) RCRA Hazardous Waste Handler Information on CD-ROM unleashes the invaluable information found in two key EPA data sources on hazardous waste handlers and offers cradle-to-grave waste tracking. It`s easy to search and display: (1) Permit status, design capacity, and compliance history for facilities found in the EPA Research Conservation and Recovery Information System (RCRIS) program tracking database; (2) Detailed information on hazardous wastes generation, management, and minimization by companies who are large quantity generators; and (3) Data on the waste management practices of treatment, storage, and disposal (TSD) facilities from the EPA Biennial Reporting System which is collectedmore » every other year. Environmental Factor`s powerful database retrieval system lets you: (1) Search for RCRA facilities by permit type, SIC code, waste codes, corrective action, or violation information, TSD status, generator and transporter status, and more. (2) View compliance information - dates of evaluation, violation, enforcement, and corrective action. (3) Lookup facilities by waste processing categories of marketing, transporting, processing, and energy recovery. (4) Use owner/operator information and names, titles, and telephone numbers of project managers for prospecting. (5) Browse detailed data on TSD facility and large quantity generators` activities such as onsite waste treatment, disposal, or recycling, offsite waste received, and waste generation and management. The product contains databases, search and retrieval software on two CD-ROMs, an installation diskette and User`s Guide. Environmental Factor has online context-sensitive help from any screen and a printed User`s Guide describing installation and step-by-step procedures for searching, retrieving, and exporting.« less

Pollination success following loss of a frequent pollinator: the role of compensatory visitation by other effective pollinators

PubMed Central

Hallett, Allysa C.; Mitchell, Randall J.; Chamberlain, Evan R.

2017-01-01

Abstract Pollinator abundance is declining worldwide and may lower the quantity and quality of pollination services to flowering plant populations. Loss of an important pollinator is often assumed to reduce the amount of pollen received by stigmas of a focal species (pollination success), yet this assumption has rarely been tested experimentally. The magnitude of the effect, if any, may depend on the relative efficiency of the remaining pollinators, and on whether the loss of one pollinator leads to changes in visitation patterns by other pollinators. To explore how a change in pollinator composition influences pollination of Asclepias verticillata, we excluded bumble bees from plots in large and small populations of this milkweed species. We then quantified pollinator visitation rates, pollen export and pollen receipt for control plots and for plots where bumble bees were experimentally excluded. We found that exclusion of bumble bees did not reduce pollen receipt by A. verticillata flowers. Visitation by Polistes wasps increased markedly following bumble bee exclusion, both in small populations (186 % increase) and in large populations (400 % increase). Because Polistes wasps were as efficient as bumble bees at pollen transfer, increased wasp visitation offset lost bumble bee pollination services. Thus, loss of a frequent pollinator will not necessarily lead to a decline in pollination success. When pollinator loss is followed by a shift in the composition and abundance of remaining pollinators, pollination success will depend on the net change in the quantity and quality of pollination services. PMID:28798863

Detecting larval export from marine reserves

PubMed Central

Pelc, R. A.; Warner, R. R.; Gaines, S. D.; Paris, C. B.

2010-01-01

Marine reserve theory suggests that where large, productive populations are protected within no-take marine reserves, fished areas outside reserves will benefit through the spillover of larvae produced in the reserves. However, empirical evidence for larval export has been sparse. Here we use a simple idealized coastline model to estimate the expected magnitude and spatial scale of larval export from no-take marine reserves across a range of reserve sizes and larval dispersal scales. Results suggest that, given the magnitude of increased production typically found in marine reserves, benefits from larval export are nearly always large enough to offset increased mortality outside marine reserves due to displaced fishing effort. However, the proportional increase in recruitment at sites outside reserves is typically small, particularly for species with long-distance (on the order of hundreds of kilometers) larval dispersal distances, making it very difficult to detect in field studies. Enhanced recruitment due to export may be detected by sampling several sites at an appropriate range of distances from reserves or at sites downcurrent of reserves in systems with directional dispersal. A review of existing empirical evidence confirms the model's suggestion that detecting export may be difficult without an exceptionally large differential in production, short-distance larval dispersal relative to reserve size, directional dispersal, or a sampling scheme that encompasses a broad range of distances from the reserves. PMID:20181570

Indicators of nitrate export from forested watersheds of the Chesapeake Bay region

Treesearch

Karl W. J. Williard

1997-01-01

Soil net nitrogen mineralization and nitrification rates were studied on nine relatively undisturbed, forested watersheds in an effort to explain the large variations in nitrate export in streamflow within the Chesapeake Bay region. The primary hypothesis tested was that nitrate export from the watersheds was positively associated with rates of net soil nitrogen...

Hydrology and landscape structure control subalpine catchment carbon export

Treesearch

Vincent Jerald Pacific

2009-01-01

Carbon export from high elevation ecosystems is a critical component of the global carbon cycle. Ecosystems in northern latitudes have become the focus of much research due to their potential as large sinks of carbon in the atmosphere. However, there exists limited understanding of the controls of carbon export from complex mountain catchments due to strong spatial and...

U.S. Hardwood Imports Grow as World Supplies Expand

Treesearch

William C. Siegel; Clark Row

1965-01-01

Rapidly increasing imports have captured a significant share of America's hardwood markets. Total imports of hardwood raw materials and building products are now four times as large as exports. Before World War II the U. S. was a net exporter of hardwoods, and imports were limited to high-quality mahogany and specialty logs and lumber. Availability of large...

Rerouting Carbon Flux To Enhance Photosynthetic Productivity

PubMed Central

Ducat, Daniel C.; Avelar-Rivas, J. Abraham; Way, Jeffrey C.

2012-01-01

The bioindustrial production of fuels, chemicals, and therapeutics typically relies upon carbohydrate inputs derived from agricultural plants, resulting in the entanglement of food and chemical commodity markets. We demonstrate the efficient production of sucrose from a cyanobacterial species, Synechococcus elongatus, heterologously expressing a symporter of protons and sucrose (cscB). cscB-expressing cyanobacteria export sucrose irreversibly to concentrations of >10 mM without culture toxicity. Moreover, sucrose-exporting cyanobacteria exhibit increased biomass production rates relative to wild-type strains, accompanied by enhanced photosystem II activity, carbon fixation, and chlorophyll content. The genetic modification of sucrose biosynthesis pathways to minimize competing glucose- or sucrose-consuming reactions can further improve sucrose production, allowing the export of sucrose at rates of up to 36.1 mg liter−1 h illumination−1. This rate of production exceeds that of previous reports of targeted, photobiological production from microbes. Engineered S. elongatus produces sucrose in sufficient quantities (up to ∼80% of total biomass) such that it may be a viable alternative to sugar synthesis from terrestrial plants, including sugarcane. PMID:22307292

Rerouting Carbon Flux To Enhance Photosynthetic Productivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ducat, DC; Avelar-Rivas, JA; Way, JC

2012-03-23

The bioindustrial production of fuels, chemicals, and therapeutics typically relies upon carbohydrate inputs derived from agricultural plants, resulting in the entanglement of food and chemical commodity markets. We demonstrate the efficient production of sucrose from a cyanobacterial species, Synechococcus elongatus, heterologously expressing a symporter of protons and sucrose (cscB). cscB-expressing cyanobacteria export sucrose irreversibly to concentrations of >10 mM without culture toxicity. Moreover, sucrose-exporting cyanobacteria exhibit increased biomass production rates relative to wild-type strains, accompanied by enhanced photosystem II activity, carbon fixation, and chlorophyll content. The genetic modification of sucrose biosynthesis pathways to minimize competing glucose-or sucrose-consuming reactions can furthermore » improve sucrose production, allowing the export of sucrose at rates of up to 36.1 mg liter(-1) h illumination(-1). This rate of production exceeds that of previous reports of targeted, photobiological production from microbes. Engineered S. elongatus produces sucrose in sufficient quantities (up to similar to 80% of total biomass) such that it may be a viable alternative to sugar synthesis from terrestrial plants, including sugarcane.« less

The Empirical Study on the Labor Export of Three Gorges Reservoir Area in China

NASA Astrophysics Data System (ADS)

Hu, Bangyong

There are many large surplus labor force in the three gorges reservoir area, export of labor services is one way to tackle the problem of employment of the surplus-labor and increase farmers income, export of labor is also a effective way to solve three rural issues. This paper analyzes the need for the development of service economy, study the problems of export of labor services, at last the author give some suggestion to develop labor economy.

Antarctic ice shelf potentially stabilized by export of meltwater in surface river.

PubMed

Bell, Robin E; Chu, Winnie; Kingslake, Jonathan; Das, Indrani; Tedesco, Marco; Tinto, Kirsty J; Zappa, Christopher J; Frezzotti, Massimo; Boghosian, Alexandra; Lee, Won Sang

2017-04-19

Meltwater stored in ponds and crevasses can weaken and fracture ice shelves, triggering their rapid disintegration. This ice-shelf collapse results in an increased flux of ice from adjacent glaciers and ice streams, thereby raising sea level globally. However, surface rivers forming on ice shelves could potentially export stored meltwater and prevent its destructive effects. Here we present evidence for persistent active drainage networks-interconnected streams, ponds and rivers-on the Nansen Ice Shelf in Antarctica that export a large fraction of the ice shelf's meltwater into the ocean. We find that active drainage has exported water off the ice surface through waterfalls and dolines for more than a century. The surface river terminates in a 130-metre-wide waterfall that can export the entire annual surface melt over the course of seven days. During warmer melt seasons, these drainage networks adapt to changing environmental conditions by remaining active for longer and exporting more water. Similar networks are present on the ice shelf in front of Petermann Glacier, Greenland, but other systems, such as on the Larsen C and Amery Ice Shelves, retain surface water at present. The underlying reasons for export versus retention remain unclear. Nonetheless our results suggest that, in a future warming climate, surface rivers could export melt off the large ice shelves surrounding Antarctica-contrary to present Antarctic ice-sheet models, which assume that meltwater is stored on the ice surface where it triggers ice-shelf disintegration.

GHGs and air pollutants embodied in China's international trade: Temporal and spatial index decomposition analysis.

PubMed

Liu, Zhengyan; Mao, Xianqiang; Song, Peng

2017-01-01

Temporal index decomposition analysis and spatial index decomposition analysis were applied to understand the driving forces of the emissions embodied in China's exports and net exports during 2002-2011, respectively. The accumulated emissions embodied in exports accounted for approximately 30% of the total emissions in China; although the contribution of the sectoral total emissions intensity (technique effect) declined, the scale effect was largely responsible for the mounting emissions associated with export, and the composition effect played a largely insignificant role. Calculations of the emissions embodied in net exports suggest that China is generally in an environmentally inferior position compared with its major trade partners. The differences in the economy-wide emission intensities between China and its major trade partners were the biggest contribution to this reality, and the trade balance effect played a less important role. However, a lower degree of specialization in pollution intensive products in exports than in imports helped to reduce slightly the emissions embodied in net exports. The temporal index decomposition analysis results suggest that China should take effective measures to optimize export and supply-side structure and reduce the total emissions intensity. According to spatial index decomposition analysis, it is suggested that a more aggressive import policy was useful for curbing domestic and global emissions, and the transfer of advanced production technologies and emission control technologies from developed to developing countries should be a compulsory global environmental policy option to mitigate the possible leakage of pollution emissions caused by international trade.

Antarctic Ice Shelf Potentially Stabilized by Export of Meltwater in Surface River

NASA Technical Reports Server (NTRS)

Bell, Robin E.; Chu, Winnie; Kingslake, Jonathan; Das, Indrani; Tedesco, Marco; Tinto, Kirsty J.; Zappa, Christopher J.; Frezzotti, Massimo; Boghosian, Alexandra; Lee, Won Sang

2017-01-01

Meltwater stored in ponds and crevasses can weaken and fracture ice shelves, triggering their rapid disintegration. This ice-shelf collapse results in an increased flux of ice from adjacent glaciers and ice streams, thereby raising sea level globally. However, surface rivers forming on ice shelves could potentially export stored meltwater and prevent its destructive effects. Here we present evidence for persistent active drainage networks-interconnected streams, ponds and rivers-on the Nansen Ice Shelf in Antarctica that export a large fraction of the ice shelf's meltwater into the ocean. We find that active drainage has exported water off the ice surface through waterfalls and dolines for more than a century. The surface river terminates in a 130-metre-wide waterfall that can export the entire annual surface melt over the course of seven days. During warmer melt seasons, these drainage networks adapt to changing environmental conditions by remaining active for longer and exporting more water. Similar networks are present on the ice shelf in front of Petermann Glacier, Greenland, but other systems, such as on the Larsen C and Amery Ice Shelves, retain surface water at present. The underlying reasons for export versus retention remain unclear. Nonetheless our results suggest that, in a future warming climate, surface rivers could export melt off the large ice shelves surrounding Antarctica-contrary to present Antarctic ice-sheet models, which assume that meltwater is stored on the ice surface where it triggers ice-shelf disintegration.

Antarctic ice shelf potentially stabilized by export of meltwater in surface river

NASA Astrophysics Data System (ADS)

Bell, Robin E.; Chu, Winnie; Kingslake, Jonathan; Das, Indrani; Tedesco, Marco; Tinto, Kirsty J.; Zappa, Christopher J.; Frezzotti, Massimo; Boghosian, Alexandra; Lee, Won Sang

2017-04-01

Meltwater stored in ponds and crevasses can weaken and fracture ice shelves, triggering their rapid disintegration. This ice-shelf collapse results in an increased flux of ice from adjacent glaciers and ice streams, thereby raising sea level globally. However, surface rivers forming on ice shelves could potentially export stored meltwater and prevent its destructive effects. Here we present evidence for persistent active drainage networks—interconnected streams, ponds and rivers—on the Nansen Ice Shelf in Antarctica that export a large fraction of the ice shelf’s meltwater into the ocean. We find that active drainage has exported water off the ice surface through waterfalls and dolines for more than a century. The surface river terminates in a 130-metre-wide waterfall that can export the entire annual surface melt over the course of seven days. During warmer melt seasons, these drainage networks adapt to changing environmental conditions by remaining active for longer and exporting more water. Similar networks are present on the ice shelf in front of Petermann Glacier, Greenland, but other systems, such as on the Larsen C and Amery Ice Shelves, retain surface water at present. The underlying reasons for export versus retention remain unclear. Nonetheless our results suggest that, in a future warming climate, surface rivers could export melt off the large ice shelves surrounding Antarctica—contrary to present Antarctic ice-sheet models, which assume that meltwater is stored on the ice surface where it triggers ice-shelf disintegration.

Corn ethanol production, food exports, and indirect land use change.

PubMed

Wallington, T J; Anderson, J E; Mueller, S A; Kolinski Morris, E; Winkler, S L; Ginder, J M; Nielsen, O J

2012-06-05

The approximately 100 million tonne per year increase in the use of corn to produce ethanol in the U.S. over the past 10 years, and projections of greater future use, have raised concerns that reduced exports of corn (and other agricultural products) and higher commodity prices would lead to land-use changes and, consequently, negative environmental impacts in other countries. The concerns have been driven by agricultural and trade models, which project that large-scale corn ethanol production leads to substantial decreases in food exports, increases in food prices, and greater deforestation globally. Over the past decade, the increased use of corn for ethanol has been largely matched by the increased corn harvest attributable mainly to increased yields. U.S. exports of corn, wheat, soybeans, pork, chicken, and beef either increased or remained unchanged. Exports of distillers' dry grains (DDG, a coproduct of ethanol production and a valuable animal feed) increased by more than an order of magnitude to 9 million tonnes in 2010. Increased biofuel production may lead to intensification (higher yields) and extensification (more land) of agricultural activities. Intensification and extensification have opposite impacts on land use change. We highlight the lack of information concerning the magnitude of intensification effects and the associated large uncertainties in assessments of the indirect land use change associated with corn ethanol.

Inverse-model estimates of the ocean's coupled phosphorus, silicon, and iron cycles

NASA Astrophysics Data System (ADS)

Pasquier, Benoît; Holzer, Mark

2017-09-01

The ocean's nutrient cycles are important for the carbon balance of the climate system and for shaping the ocean's distribution of dissolved elements. Dissolved iron (dFe) is a key limiting micronutrient, but iron scavenging is observationally poorly constrained, leading to large uncertainties in the external sources of iron and hence in the state of the marine iron cycle. Here we build a steady-state model of the ocean's coupled phosphorus, silicon, and iron cycles embedded in a data-assimilated steady-state global ocean circulation. The model includes the redissolution of scavenged iron, parameterization of subgrid topography, and small, large, and diatom phytoplankton functional classes. Phytoplankton concentrations are implicitly represented in the parameterization of biological nutrient utilization through an equilibrium logistic model. Our formulation thus has only three coupled nutrient tracers, the three-dimensional distributions of which are found using a Newton solver. The very efficient numerics allow us to use the model in inverse mode to objectively constrain many biogeochemical parameters by minimizing the mismatch between modeled and observed nutrient and phytoplankton concentrations. Iron source and sink parameters cannot jointly be optimized because of local compensation between regeneration, recycling, and scavenging. We therefore consider a family of possible state estimates corresponding to a wide range of external iron source strengths. All state estimates have a similar mismatch with the observed nutrient concentrations and very similar large-scale dFe distributions. However, the relative contributions of aeolian, sedimentary, and hydrothermal iron to the total dFe concentration differ widely depending on the sources. Both the magnitude and pattern of the phosphorus and opal exports are well constrained, with global values of 8. 1 ± 0. 3 Tmol P yr-1 (or, in carbon units, 10. 3 ± 0. 4 Pg C yr-1) and 171. ± 3. Tmol Si yr-1. We diagnose the phosphorus and opal exports supported by aeolian, sedimentary, and hydrothermal iron. The geographic patterns of the export supported by each iron type are well constrained across the family of state estimates. Sedimentary-iron-supported export is important in shelf and large-scale upwelling regions, while hydrothermal iron contributes to export mostly in the Southern Ocean. The fraction of the global export supported by a given iron type varies systematically with its fractional contribution to the total iron source. Aeolian iron is most efficient in supporting export in the sense that its fractional contribution to export exceeds its fractional contribution to the total source. Per source-injected molecule, aeolian iron supports 3. 1 ± 0. 8 times more phosphorus export and 2. 0 ± 0. 5 times more opal export than the other iron types. Conversely, per injected molecule, sedimentary and hydrothermal iron support 2. 3 ± 0. 6 and 4. ± 2. times less phosphorus export, and 1. 9 ± 0. 5 and 2. ± 1. times less opal export than the other iron types.

Stormwater management impacts on urban stream water quality and quantity during and after development in Clarksburg, MD

NASA Astrophysics Data System (ADS)

Loperfido, J. V.; Noe, G. B.; Jarnagin, S.; Mohamoud, Y. M.; Van Ness, K.; Hogan, D. M.

2012-12-01

Urbanization and urban land use leads to degradation of local stream habitat and 'urban stream syndrome.' Best Management Practices (BMPs) are often used in an attempt to mitigate the impact of urban land use on stream water quality and quantity. Traditional development has employed stormwater BMPs that were placed in a centralized manner located either in the stream channel or near the riparian zone to treat stormwater runoff from large drainage areas; however, urban streams have largely remained impaired. Recently, distributed placement of BMPs throughout the landscape has been implemented in an attempt to detain, treat, and infiltrate stormwater runoff from smaller drainage areas near its source. Despite increasing implementation of distributed BMPs, little has been reported on the catchment-scale (1-10 km^2) performance of distributed BMPs and how they compare to centralized BMPs. The Clarksburg Special Protection Area (CSPA), located in the Washington, DC exurbs within the larger Chesapeake Bay watershed, is undergoing rapid urbanization and employs distributed BMPs on the landscape that treat small drainage areas with the goal of preserving high-quality stream resources in the area. In addition, the presence of a nearby traditionally developed (centralized BMPs) catchment and an undeveloped forested catchment makes the CSPA an ideal setting to understand how the best available stormwater management technology implemented during and after development affects stream water quality and quantity through a comparative watershed analysis. The Clarksburg Integrated Monitoring Partnership is a consortium of local and federal agencies and universities that conducts research in the CSPA including: monitoring of stream water quality, geomorphology, and biology; analysis of stream hydrological and water quality data; and GIS mapping and analysis of land cover, elevation change and BMP implementation data. Here, the impacts of urbanization on stream water quantity, geomorphology, and biology during development while implementing advanced sediment and erosion control BMPs are discussed. Also, effects of centralized versus distributed stormwater BMPs and land cover on stream water quantity and quality following suburban development are presented. This includes stream response to precipitation events, baseflow and stormflow export of water, and water chemistry data. Results from this work have informed land use planning at the local level and are being incorporated through adaptive management to maintain the high-quality stream resources in the CSPA. More generally, results from this work could inform urban development stakeholders on effective strategies to curtail urban stream syndrome.

75 FR 69403 - Aluminum Extrusions From the People's Republic of China: Notice of Preliminary Determination of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-12

... section 733(c)(1)(A) of the Act and 19 CFR 351.205(b)(2) and (e) for a 50-day postponement of the... PRC is an NME country.\\13\\ In accordance with section 771(18)(C)(i) of the Act, the NME status remains... accordance with section 777A(c)(2) of the Act, the Department selected the two largest exporters (by quantity...

Selected Translations on East European Foreign Trade, No. 5.

DTIC Science & Technology

1961-08-31

eggs, cereals, oil -yielding seeds , and pulped fruit represented 2/3 of all exports. At the same time, unprocessed agricultural products [sic...prefer these raw materials, mainly grain, livestock for meat, and scarce oil - seeds , but show very little interest in, for instance, fruit pulps, which in...mineral materials, and metals. This is because the quantities of oil derivatives and cast iron are increased, and coal and iron ore from the Donets

The Brazilian Aerospace Industry: A Cast Study of the Technological Impact of Offset Agreements in a Recipient Industry

DTIC Science & Technology

1989-12-01

Special Export Programs, Comissco de Beneficios Fiscais e Programas Especiais de Exportagdo - BEFIEX. This program allows the rebate of tariff and...development became a specific policy objective. The 1968-69 Development Plan, Programa Estrat6gico de Desenvolvimento (PED), defined an explicit...Comunicagdo de Programa de Aquisigdo - CPA) containing: object, quantity, delivery time, value, nature, and other basic elements of contracting. To comply

Unintended consequences of biofuels production?The effects of large-scale crop conversion on water quality and quantity

USGS Publications Warehouse

Welch, Heather L.; Green, Christopher T.; Rebich, Richard A.; Barlow, Jeannie R.B.; Hicks, Matthew B.

2010-01-01

In the search for renewable fuel alternatives, biofuels have gained strong political momentum. In the last decade, extensive mandates, policies, and subsidies have been adopted to foster the development of a biofuels industry in the United States. The Biofuels Initiative in the Mississippi Delta resulted in a 47-percent decrease in cotton acreage with a concurrent 288-percent increase in corn acreage in 2007. Because corn uses 80 percent more water for irrigation than cotton, and more nitrogen fertilizer is recommended for corn cultivation than for cotton, this widespread shift in crop type has implications for water quantity and water quality in the Delta. Increased water use for corn is accelerating water-level declines in the Mississippi River Valley alluvial aquifer at a time when conservation is being encouraged because of concerns about sustainability of the groundwater resource. Results from a mathematical model calibrated to existing conditions in the Delta indicate that increased fertilizer application on corn also likely will increase the extent of nitrate-nitrogen movement into the alluvial aquifer. Preliminary estimates based on surface-water modeling results indicate that higher application rates of nitrogen increase the nitrogen exported from the Yazoo River Basin to the Mississippi River by about 7 percent. Thus, the shift from cotton to corn may further contribute to hypoxic (low dissolved oxygen) conditions in the Gulf of Mexico.

Loss of nutrients from terrestrial ecosystems to streams and the atmosphere following land use change in Amazonia

NASA Astrophysics Data System (ADS)

Davidson, Eric A.; Neill, Christopher; Krusche, Alex V.; Ballester, Victoria V. R.; Markewitz, Daniel; Figueiredo, Ricardo de O.

Rates of deforestation in the Amazon region have been accelerating, but the quantity and timing of nutrient losses from forested and deforested ecosystems are poorly understood. This paper investigates the broad variation in soil properties of the Amazon Basin as they influence transfers of plant nutrients from the terrestrial biosphere to the atmosphere and the aquatic biosphere. The dominant lowland soils are highly weathered Oxisols and Ultisols, but significant areas of Alfisols also exist, resulting in a wide range of weatherable primary minerals. Despite this considerable variation among Amazonian soils, a common feature in most mature lowland Amazonian forests is a conservative P cycle and excess N availability. In cattle pastures and secondary forests, however, low rates of internal terrestrial N cycling, low N export to streams, and low gaseous N emissions from soils are common, due to significant previous losses of N through repeated fire. Export of P to streams may increase or remain nearly undetectable after forest-to-pasture conversion, depending on soil type. Oxisols exhibit very low P export, whereas increased P export to pasture streams has been observed in Ultisols of western Amazonia. Calcium is mostly retained in terrestrial ecosystems following deforestation, although increased inputs to streams can be detected when background fluxes are naturally low. Because soil mineralogy and soil texture are both variable and important, the effects of land-use change on nutrient export to aquatic ecosystems and to the atmosphere must be understood within the context of varying soil properties across the Amazon Basin.

An Arctic source for the Great Salinity Anomaly - A simulation of the Arctic ice-ocean system for 1955-1975

NASA Technical Reports Server (NTRS)

Hakkinen, Sirpa

1993-01-01

The paper employs a fully prognostic Arctic ice-ocean model to study the interannual variability of sea ice during the period 1955-1975 and to explain the large variability of the ice extent in the Greenland and Iceland seas during the late 1960s. The model is used to test the contention of Aagaard and Carmack (1989) that the Great Salinity Anomaly (GSA) was a consequence of the anomalously large ice export in 1968. The high-latitude ice-ocean circulation changes due to wind field changes are explored. The ice export event of 1968 was the largest in the simulation, being about twice as large as the average and corresponding to 1600 cu km of excess fresh water. The simulations suggest that, besides the above average ice export to the Greenland Sea, there was also fresh water export to support the larger than average ice cover. The model results show the origin of the GSA to be in the Arctic, and support the view that the Arctic may play an active role in climate change.

Inferring tidal wetland stability from channel sediment fluxes: observations and a conceptual model

USGS Publications Warehouse

Ganju, Neil K.; Nidzieko, Nicholas J.; Kirwan, Matthew L.

2013-01-01

Anthropogenic and climatic forces have modified the geomorphology of tidal wetlands over a range of timescales. Changes in land use, sediment supply, river flow, storminess, and sea level alter the layout of tidal channels, intertidal flats, and marsh plains; these elements define wetland complexes. Diagnostically, measurements of net sediment fluxes through tidal channels are high-temporal resolution, spatially integrated quantities that indicate (1) whether a complex is stable over seasonal timescales and (2) what mechanisms are leading to that state. We estimated sediment fluxes through tidal channels draining wetland complexes on the Blackwater and Transquaking Rivers, Maryland, USA. While the Blackwater complex has experienced decades of degradation and been largely converted to open water, the Transquaking complex has persisted as an expansive, vegetated marsh. The measured net export at the Blackwater complex (1.0 kg/s or 0.56 kg/m2/yr over the landward marsh area) was caused by northwesterly winds, which exported water and sediment on the subtidal timescale; tidally forced net fluxes were weak and precluded landward transport of suspended sediment from potential seaward sources. Though wind forcing also exported sediment at the Transquaking complex, strong tidal forcing and proximity to a turbidity maximum led to an import of sediment (0.031 kg/s or 0.70 kg/m2/yr). This resulted in a spatially averaged accretion of 3.9 mm/yr, equaling the regional relative sea level rise. Our results suggest that in areas where seaward sediment supply is dominant, seaward wetlands may be more capable of withstanding sea level rise over the short term than landward wetlands. We propose a conceptual model to determine a complex's tendency toward stability or instability based on sediment source, wetland channel location, and transport mechanisms. Wetlands with a reliable portfolio of sources and transport mechanisms appear better suited to offset natural and anthropogenic loss.

Assessing the Age of Particulate Organic Matter Exported from a Temperate Rainforest Catchment of the North American Pacific Coast

NASA Astrophysics Data System (ADS)

Martin, E. E.; Ingalls, A. E.; Santos, G.; Keil, R. G.; Wefferling, L.; Jones, A.; Druffel, E. R. M.

2015-12-01

Although temperate rainforests of the North American Pacific Coast contain a small proportion of the world's forests, they contain some of the highest densities of biomass of any terrestrial system, and they store large quantities of carbon in soil. Understanding the residence time of organic carbon in these watersheds is of ecological significance. Given that rivers can mobilize sediment (and associated carbon) from across the catchment, carefully deciphering the organic signatures found within riverine particles can be a powerful tool to inform our understanding of carbon cycling catchment-wide. Here we examine the lignin phenol content (lignin is a biomarker unique to vascular plants) and the radiocarbon age (Δ14C) of fine particulate organic carbon (FPOC) exported by the Queets River of Washington State's Olympic Peninsula over the course of one year, targeting winter storm events. This mountainous catchment is one of the largest and most pristine found on the Olympic Peninsula. The Δ14C of FPOC was quantified for each of the twelve sampling events, whereas the Δ14C of the individual lignin phenols was determined during a late-winter storm event. Sediments were enriched in lignin phenols at the end of the summer dry season and into the first storm of the fall, suggesting that surface soils were transported early on. The Δ14C of individual lignin phenols ranged from -161 to 26‰, with biomarkers for non-woody vegetation being most depleted. These results suggest that particulate lignin exported from temperate catchments is considerably aged, especially relative to the tropics. These findings are consistent with cool temperatures and abundant moisture limiting microbial decomposition, increasing the residence time of plant-derived organic carbon in temperate rainforests. We will compare the Δ14C content of lignin phenols to that of bulk organic matter to partition riverine FPOC amongst possible organic matter sources.

International red meat trade.

PubMed

Brester, Gary W; Marsh, John M; Plain, Ronald L

2003-07-01

The maturation of the US beef and pork markets and increasing consumer demands for convenience, safety, and nutrition suggests that the beef and pork industries must focus on product development and promotion. New marketing arrangements are developing that help coordinate production with consumer demands. The relative high levels of incomes in the United States are likely to increase the demands for branded products rather than increase total per capita consumption. Foreign markets represent the greatest opportunity for increased demand for commodity beef and pork products. Increasing incomes in developing countries will likely allow consumers to increase consumption of animal-source proteins. Real prices of beef and pork have declined substantially because of sagging domestic demand and increasing farm-level production technologies. Increasing US beef and pork exports have obviated some of the price declines. Pork attained a net export position from a quantity perspective in 1995. The United States continues to be a net importer of beef on a quantity basis but is close to becoming a net exporter in terms of value. By-products continue to play a critical role in determining the red meat trade balance and producer prices. The United States, however, must continue to become cost, price, and quality competitive with other suppliers and must secure additional market access if it is to sustain recent trade trends. Several trade tensions remain in the red meat industry. For example, mandated COOL will undoubtedly have domestic and international effects on the beef and pork sectors. Domestically, uncertainty regarding consumer demand responses or quality perceptions regarding product origin, as well as added processor-retailer costs will be nontrivial. How these factors balance out in terms of benefits versus costs to the industry is uncertain. From an international perspective, some beef and pork export suppliers to the United States could view required labeling as a trade restriction, which could ultimately impact future US red meat exports. Conversely, some countries may view such labeling requirements as an opportunity to brand high-quality products. The US lamb meat industry has experienced declining real prices, domestic production, and demand. The cessation of wool incentive payments, increased environmental regulations, and competition by imports have significantly affected the industry. Import suppliers have capitalized on product quality in this niche market. Trade restrictions initially imposed in 1999 by the US Government were ruled illegal by the WTO. The US Government responded by providing financial assistance to lamb producers. Product quality improvements and promotion aimed at the domestic market, however, will be critical factors in shaping the economic viability of the US lamb meat industry.

Amazon River carbon dioxide outgassing fuelled by wetlands.

PubMed

Abril, Gwenaël; Martinez, Jean-Michel; Artigas, L Felipe; Moreira-Turcq, Patricia; Benedetti, Marc F; Vidal, Luciana; Meziane, Tarik; Kim, Jung-Hyun; Bernardes, Marcelo C; Savoye, Nicolas; Deborde, Jonathan; Souza, Edivaldo Lima; Albéric, Patrick; Landim de Souza, Marcelo F; Roland, Fabio

2014-01-16

River systems connect the terrestrial biosphere, the atmosphere and the ocean in the global carbon cycle. A recent estimate suggests that up to 3 petagrams of carbon per year could be emitted as carbon dioxide (CO2) from global inland waters, offsetting the carbon uptake by terrestrial ecosystems. It is generally assumed that inland waters emit carbon that has been previously fixed upstream by land plant photosynthesis, then transferred to soils, and subsequently transported downstream in run-off. But at the scale of entire drainage basins, the lateral carbon fluxes carried by small rivers upstream do not account for all of the CO2 emitted from inundated areas downstream. Three-quarters of the world's flooded land consists of temporary wetlands, but the contribution of these productive ecosystems to the inland water carbon budget has been largely overlooked. Here we show that wetlands pump large amounts of atmospheric CO2 into river waters in the floodplains of the central Amazon. Flooded forests and floating vegetation export large amounts of carbon to river waters and the dissolved CO2 can be transported dozens to hundreds of kilometres downstream before being emitted. We estimate that Amazonian wetlands export half of their gross primary production to river waters as dissolved CO2 and organic carbon, compared with only a few per cent of gross primary production exported in upland (not flooded) ecosystems. Moreover, we suggest that wetland carbon export is potentially large enough to account for at least the 0.21 petagrams of carbon emitted per year as CO2 from the central Amazon River and its floodplains. Global carbon budgets should explicitly address temporary or vegetated flooded areas, because these ecosystems combine high aerial primary production with large, fast carbon export, potentially supporting a substantial fraction of CO2 evasion from inland waters.

GHGs and air pollutants embodied in China’s international trade: Temporal and spatial index decomposition analysis

PubMed Central

Liu, Zhengyan; Mao, Xianqiang; Song, Peng

2017-01-01

Temporal index decomposition analysis and spatial index decomposition analysis were applied to understand the driving forces of the emissions embodied in China’s exports and net exports during 2002–2011, respectively. The accumulated emissions embodied in exports accounted for approximately 30% of the total emissions in China; although the contribution of the sectoral total emissions intensity (technique effect) declined, the scale effect was largely responsible for the mounting emissions associated with export, and the composition effect played a largely insignificant role. Calculations of the emissions embodied in net exports suggest that China is generally in an environmentally inferior position compared with its major trade partners. The differences in the economy-wide emission intensities between China and its major trade partners were the biggest contribution to this reality, and the trade balance effect played a less important role. However, a lower degree of specialization in pollution intensive products in exports than in imports helped to reduce slightly the emissions embodied in net exports. The temporal index decomposition analysis results suggest that China should take effective measures to optimize export and supply-side structure and reduce the total emissions intensity. According to spatial index decomposition analysis, it is suggested that a more aggressive import policy was useful for curbing domestic and global emissions, and the transfer of advanced production technologies and emission control technologies from developed to developing countries should be a compulsory global environmental policy option to mitigate the possible leakage of pollution emissions caused by international trade. PMID:28441399

In Vitro Comparison of Adipokine Export Signals.

PubMed

Sharafi, Parisa; Kocaefe, Y Çetin

2016-01-01

Mammalian cells are widely used for recombinant protein production in research and biotechnology. Utilization of export signals significantly facilitates production and purification processes. 35 years after the discovery of the mammalian export machinery, there still are obscurities regarding the efficiency of the export signals. The aim of this study was the comparative evaluation of the efficiency of selected export signals using adipocytes as a cell model. Adipocytes have a large capacity for protein secretion including several enzymes, adipokines, and other signaling molecules, providing a valid system for a quantitative evaluation. Constructs that expressed N-terminal fusion export signals were generated to express Enhanced Green Fluorescence Protein (EGFP) as a reporter for quantitative and qualitative evaluation. Furthermore, fluorescent microscopy was used to trace the intracellular traffic of the reporter. The export efficiency of six selected proteins secreted from adipocytes was evaluated. Quantitative comparison of intracellular and exported fractions of the recombinant constructs demonstrated a similar efficiency among the studied sequences with minor variations. The export signal of Retinol Binding Protein (RBP4) exhibited the highest efficiency. This study presents the first quantitative data showing variations among export signals, in adipocytes which will help optimization of recombinant protein distribution.

Environmental Factor(tm) system: RCRA hazardous waste handler information (on cd-rom). Database

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-04-01

Environmental Factor(tm) RCRA Hazardous Waste Handler Information on CD-ROM unleashes the invaluable information found in two key EPA data sources on hazardous waste handlers and offers cradle-to-grave waste tracking. It`s easy to search and display: (1) Permit status, design capacity and compliance history for facilities found in the EPA Resource Conservation and Recovery Information System (RCRIS) program tracking database; (2) Detailed information on hazardous wastes generation, management and minimization by companies who are large quantity generators, and (3) Data on the waste management practices of treatment, storage and disposal (TSD) facilities from the EPA Biennial Reporting System which is collectedmore » every other year. Environmental Factor`s powerful database retrieval system lets you: (1) Search for RCRA facilities by permit type, SIC code, waste codes, corrective action or violation information, TSD status, generator and transporter status and more; (2) View compliance information - dates of evaluation, violation, enforcement and corrective action; (3) Lookup facilities by waste processing categories of marketing, transporting, processing and energy recovery; (4) Use owner/operator information and names, titles and telephone numbers of project managers for prospecting; and (5) Browse detailed data on TSD facility and large quantity generators` activities such as onsite waste treatment, disposal, or recycling, offsite waste received, and waste generation and management. The product contains databases, search and retrieval software on two CD-ROMs, an installation diskette and User`s Guide. Environmental Factor has online context-sensitive help from any screen and a printed User`s Guide describing installation and step-by-step procedures for searching, retrieving and exporting. Hotline support is also available for no additional charge.« less

Environmental Factor{trademark} system: RCRA hazardous waste handler information

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1999-03-01

Environmental Factor{trademark} RCRA Hazardous Waste Handler Information on CD-ROM unleashes the invaluable information found in two key EPA data sources on hazardous waste handlers and offers cradle-to-grave waste tracking. It`s easy to search and display: (1) Permit status, design capacity and compliance history for facilities found in the EPA Resource Conservation and Recovery Information System (RCRIS) program tracking database; (2) Detailed information on hazardous wastes generation, management and minimization by companies who are large quantity generators, and (3) Data on the waste management practices of treatment, storage and disposal (TSD) facilities from the EPA Biennial Reporting System which is collectedmore » every other year. Environmental Factor`s powerful database retrieval system lets you: (1) Search for RCRA facilities by permit type, SIC code, waste codes, corrective action or violation information, TSD status, generator and transporter status and more; (2) View compliance information -- dates of evaluation, violation, enforcement and corrective action; (3) Lookup facilities by waste processing categories of marketing, transporting, processing and energy recovery; (4) Use owner/operator information and names, titles and telephone numbers of project managers for prospecting; and (5) Browse detailed data on TSD facility and large quantity generators` activities such as onsite waste treatment, disposal, or recycling, offsite waste received, and waste generation and management. The product contains databases, search and retrieval software on two CD-ROMs, an installation diskette and User`s Guide. Environmental Factor has online context-sensitive help from any screen and a printed User`s Guide describing installation and step-by-step procedures for searching, retrieving and exporting. Hotline support is also available for no additional charge.« less

Identification of Bicarbonate as a Trigger and Genes Involved with Extracellular DNA Export in Mycobacterial Biofilms.

PubMed

Rose, Sasha J; Bermudez, Luiz E

2016-12-06

Extracellular DNA (eDNA) is an integral biofilm matrix component of numerous pathogens, including nontuberculous mycobacteria (NTM). Cell lysis is the source of eDNA in certain bacteria, but the source of eDNA remains unidentified for NTM, as well as for other eDNA-containing bacterial species. In this study, conditions affecting eDNA export were examined, and genes involved with the eDNA export mechanism were identified. After a method for monitoring eDNA in real time in undisturbed biofilms was established, different conditions affecting eDNA were investigated. Bicarbonate positively influenced eDNA export in a pH-independent manner in Mycobacterium avium, M. abscessus, and M. chelonae The surface-exposed proteome of M. avium in eDNA-containing biofilms revealed abundant carbonic anhydrases. Chemical inhibition of carbonic anhydrases with ethoxzolamide significantly reduced eDNA export. An unbiased transposon mutant library screen for eDNA export in M. avium identified many severely eDNA-attenuated mutants, including one not expressing a unique FtsK/SpoIIIE-like DNA-transporting pore, two with inactivation of carbonic anhydrases, and nine with inactivation of genes belonging to a unique genomic region, as well as numerous mutants involved in metabolism and energy production. Complementation of nine mutants that included the FtsK/SpoIIIE and carbonic anhydrase significantly restored eDNA export. Interestingly, several attenuated eDNA mutants have mutations in genes encoding proteins that were found with the surface proteomics, and many more mutations are localized in operons potentially encoding surface proteins. Collectively, our data strengthen the evidence of eDNA export being an active mechanism that is activated by the bacterium responding to bicarbonate. Many bacteria contain extracellular DNA (eDNA) in their biofilm matrix, as it has various biological and physical functions. We recently reported that nontuberculous mycobacteria (NTM) can contain significant quantities of eDNA in their biofilms. In some bacteria, eDNA is derived from dead cells, but that does not appear to be the case for all eDNA-containing organisms, including NTM. In this study, we found that eDNA export in NTM is conditionally dependent on the molecules to which the bacteria are exposed and that bicarbonate positively influences eDNA export. We also identified genes and proteins important for eDNA export, which begins to piece together a description of a mechanism for eDNA. Better understanding of eDNA export can give new targets for the development of antivirulence drugs, which are attractive because resistance to classical antibiotics is currently a significant problem. Copyright © 2016 Rose and Bermudez.

Influence of land cover on riverine dissolved organic carbon concentrations and export in the Three Rivers Headwater Region of the Qinghai-Tibetan Plateau.

PubMed

Ma, Xiaoliang; Liu, Guimin; Wu, Xiaodong; Smoak, Joseph M; Ye, Linlin; Xu, Haiyan; Zhao, Lin; Ding, Yongjian

2018-07-15

The Qinghai-Tibetan plateau (QTP) stores a large amount of soil organic carbon and is the headwater region for several large rivers in Asia. Therefore, it is important to understand the influence of environmental factors on river water quality and the dissolved organic carbon (DOC) export in this region. We examined the water physico-chemical characteristics, DOC concentrations and export rates of 7 rivers under typical land cover types in the Three Rivers Headwater Region during August 2016. The results showed that the highest DOC concentrations were recorded in the rivers within the catchment of alpine wet meadow and meadow. These same rivers had the lowest total suspended solids (TSS) concentrations. The rivers within steppe and desert had the lowest DOC concentrations and highest TSS concentrations. The discharge rates and catchment areas were negatively correlated with DOC concentrations. The SUVA 254 values were significantly negatively correlated with DOC concentrations. The results suggest that the vegetation degradation, which may represent permafrost degradation, can lead to a decrease in DOC concentration, but increasing DOC export and soil erosion. In addition, some of the exported DOC will rapidly decompose in the river, and therefore affect the regional carbon cycle, as well as the water quality in the source water of many large Asian rivers. Copyright © 2018 Elsevier B.V. All rights reserved.

Flux and age of dissolved organic carbon exported to the Arctic Ocean: A carbon isotopic study of the five largest arctic rivers

USGS Publications Warehouse

Raymond, P.A.; McClelland, J.W.; Holmes, R.M.; Zhulidov, A.V.; Mull, K.; Peterson, B.J.; Striegl, Robert G.; Aiken, G.R.; Gurtovaya, T.Y.

2007-01-01

The export and Δ14C-age of dissolved organic carbon (DOC) was determined for the Yenisey, Lena, Ob', Mackenzie, and Yukon rivers for 2004–2005. Concentrations of DOC elevate significantly with increasing discharge in these rivers, causing approximately 60% of the annual export to occur during a 2-month period following spring ice breakup. We present a total annual flux from the five rivers of ∼16 teragrams (Tg), and conservatively estimate that the total input of DOC to the Arctic Ocean is 25–36 Tg, which is ∼5–20% greater than previous fluxes. These fluxes are also ∼2.5× greater than temperate rivers with similar watershed sizes and water discharge. Δ14C-DOC shows a clear relationship with hydrology. A small pool of DOC slightly depleted in Δ14C is exported with base flow. The large pool exported with spring thaw is enriched in Δ14C with respect to current-day atmospheric Δ14C-CO2 values. A simple model predicts that ∼50% of DOC exported during the arctic spring thaw is 1–5 years old, ∼25% is 6–10 years in age, and 15% is 11–20 years old. The dominant spring melt period, a historically undersampled period, exports a large amount of young and presumably semilabile DOC to the Arctic Ocean.

Recent evolution of China's virtual water trade: analysis of selected crops and considerations for policy

NASA Astrophysics Data System (ADS)

Shi, J.; Liu, J.; Pinter, L.

2014-04-01

China has dramatically increased its virtual water import over recent years. Many studies have focused on the quantity of traded virtual water, but very few go into analysing geographic distribution and the properties of China's virtual water trade network. This paper provides a calculation and analysis of the crop-related virtual water trade network of China based on 27 major primary crops between 1986 and 2009. The results show that China is a net importer of virtual water from water-abundant areas of North America and South America, and a net virtual water exporter to water-stressed areas of Asia, Africa, and Europe. Virtual water import is far larger than virtual water export, and in both import and export a small number of trade partners control the supply chain. Grain crops are the major contributors to virtual water trade, and among grain crops, soybeans, mostly imported from the US, Brazil and Argentina, are the most significant. In order to mitigate water scarcity and secure the food supply, virtual water should actively be incorporated into national water management strategies. And the sources of virtual water import need to be further diversified to reduce supply chain risks and increase resilience.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Developing nations that are not members of the Organization of Petroleum Exporting Countries (OPEC) are not expected to suffer as much economic disruption from oil price increases and a US recession as happened during the 1973--1975 period. The latest price increase represents about 0.7 percent of their gross national product (GNP) compared to 2.5 percent in the earlier period. More non-OPEC developing countries are producing commercial quantities of oil and at least 14 are now net exporters. The effects of a US recession may not be as severe this time because it will not be synchronized with the business cyclesmore » of the major industrial countries. Developing countries can counteract a US recession by tightening their monetary policies, imposing import control, and other measures. Most of these countries have improved their balance of payments since 1975 and are in a position to handle disruptions.« less

Export Time of Earthquake-Derived Landslides in Active Mountain Ranges

NASA Astrophysics Data System (ADS)

Croissant, T.; Lague, D.; Steer, P.; Davy, P.

2016-12-01

In active mountain ranges, large earthquakes (Mw > 5-6) trigger numerous landslides that impact river dynamics. These landslides bring local and sudden sediment deposits which are eroded and transported along the river network, causing downstream changes in river geometry, transport capacity and erosion efficiency. The progressive removal of landslide materials has implications for downstream hazards management and for landscape dynamics at the timescale of the seismic cycle. Although the export time of suspended sediments from landslides triggered by large-magnitude earthquakes has been extensively studied, the processes and time scales associated to bedload transport remains poorly studied. Here, we study the sediment export of large landslides with the 2D morphodynamic model, Eros. This model combines: (i) an hydrodynamic model, (ii) a sediment transport and deposition model and (iii) a lateral erosion model. Eros is particularly well suited for this issue as it accounts for the complex retro-actions between sediment transport and fluvial geometry for rivers submitted to external forcings such as abrupt sediment supply increase. Using a simplified synthetic topography we systematically study the influence of pulse volume (Vs) and channel transport capacity (QT) on the export time of landslides. The range of simulated river behavior includes landslide vertical incision, its subsequent removal by lateral erosion and the river morphology modifications induced by downstream sediment propagation. The morphodynamic adaptation of the river increases its transport capacity along the channel and tends to accelerate the landslide evacuation. Our results highlight two regimes: (i) the export time is linearly related to Vs/QT when the sediment pulse introduced in the river does not affect significantly the river hydrodynamic (low Vs/QT) and (ii) the export time is a non-linear function of Vs/QT when the pulse undergoes significant morphodynamic modifications during its evacuation (high Vs/QT). By combining our newly derived export time functions with the frequency-magnitude of earthquake intensity and the induced sediment production, we investigate the sediment export of several plausible earthquake scenarii in different mountain ranges (New Zealand, Taiwan, Nepal).

Experimental evidence of formation of transparent exopolymer particles (TEP) and POC export provoked by dust addition under current and high pCO2 conditions

PubMed Central

Pedrotti, Maria Luiza; Gazeau, Frédéric; Guieu, Cécile

2017-01-01

The evolution of organic carbon export to the deep ocean, under anthropogenic forcing such as ocean warming and acidification, needs to be investigated in order to evaluate potential positive or negative feedbacks on atmospheric CO2 concentrations, and therefore on climate. As such, modifications of aggregation processes driven by transparent exopolymer particles (TEP) formation have the potential to affect carbon export. The objectives of this study were to experimentally assess the dynamics of organic matter, after the simulation of a Saharan dust deposition event, through the measurement over one week of TEP abundance and size, and to evaluate the effects of ocean acidification on TEP formation and carbon export following a dust deposition event. Three experiments were performed in the laboratory using 300 L tanks filled with filtered seawater collected in the Mediterranean Sea, during two ‘no bloom’ periods (spring at the start of the stratification period and autumn at the end of this stratification period) and during the winter bloom period. For each experiment, one of the two tanks was acidified to reach pH conditions slightly below values projected for 2100 (~ 7.6–7.8). In both tanks, a dust deposition event of 10 g m-2 was simulated at the surface. Our results suggest that Saharan dust deposition triggered the abiotic formation of TEP, leading to the formation of organic-mineral aggregates. The amount of particulate organic carbon (POC) exported was proportional to the flux of lithogenic particles to the sediment traps. Depending on the season, the POC flux following artificial dust deposition ranged between 38 and 90 mg m-2 over six experimental days. Such variability is likely linked to the seasonal differences in the quality and quantity of TEP-precursors initially present in seawater. Finally, these export fluxes were not significantly different at the completion of the three experiments between the two pH conditions. PMID:28212418

Experimental evidence of formation of transparent exopolymer particles (TEP) and POC export provoked by dust addition under current and high pCO2 conditions.

PubMed

Louis, Justine; Pedrotti, Maria Luiza; Gazeau, Frédéric; Guieu, Cécile

2017-01-01

The evolution of organic carbon export to the deep ocean, under anthropogenic forcing such as ocean warming and acidification, needs to be investigated in order to evaluate potential positive or negative feedbacks on atmospheric CO2 concentrations, and therefore on climate. As such, modifications of aggregation processes driven by transparent exopolymer particles (TEP) formation have the potential to affect carbon export. The objectives of this study were to experimentally assess the dynamics of organic matter, after the simulation of a Saharan dust deposition event, through the measurement over one week of TEP abundance and size, and to evaluate the effects of ocean acidification on TEP formation and carbon export following a dust deposition event. Three experiments were performed in the laboratory using 300 L tanks filled with filtered seawater collected in the Mediterranean Sea, during two 'no bloom' periods (spring at the start of the stratification period and autumn at the end of this stratification period) and during the winter bloom period. For each experiment, one of the two tanks was acidified to reach pH conditions slightly below values projected for 2100 (~ 7.6-7.8). In both tanks, a dust deposition event of 10 g m-2 was simulated at the surface. Our results suggest that Saharan dust deposition triggered the abiotic formation of TEP, leading to the formation of organic-mineral aggregates. The amount of particulate organic carbon (POC) exported was proportional to the flux of lithogenic particles to the sediment traps. Depending on the season, the POC flux following artificial dust deposition ranged between 38 and 90 mg m-2 over six experimental days. Such variability is likely linked to the seasonal differences in the quality and quantity of TEP-precursors initially present in seawater. Finally, these export fluxes were not significantly different at the completion of the three experiments between the two pH conditions.

The simulated climate of the Last Glacial Maximum and insights into the global marine carbon cycle

NASA Astrophysics Data System (ADS)

Buchanan, Pearse J.; Matear, Richard J.; Lenton, Andrew; Phipps, Steven J.; Chase, Zanna; Etheridge, David M.

2016-12-01

The ocean's ability to store large quantities of carbon, combined with the millennial longevity over which this reservoir is overturned, has implicated the ocean as a key driver of glacial-interglacial climates. However, the combination of processes that cause an accumulation of carbon within the ocean during glacial periods is still under debate. Here we present simulations of the Last Glacial Maximum (LGM) using the CSIRO Mk3L-COAL (Carbon-Ocean-Atmosphere-Land) earth system model to test the contribution of physical and biogeochemical processes to ocean carbon storage. For the LGM simulation, we find a significant global cooling of the surface ocean (3.2 °C) and the expansion of both minimum and maximum sea ice cover broadly consistent with proxy reconstructions. The glacial ocean stores an additional 267 Pg C in the deep ocean relative to the pre-industrial (PI) simulation due to stronger Antarctic Bottom Water formation. However, 889 Pg C is lost from the upper ocean via equilibration with a lower atmospheric CO2 concentration and a global decrease in export production, causing a net loss of carbon relative to the PI ocean. The LGM deep ocean also experiences an oxygenation ( > 100 mmol O2 m-3) and deepening of the calcite saturation horizon (exceeds the ocean bottom) at odds with proxy reconstructions. With modifications to key biogeochemical processes, which include an increased export of organic matter due to a simulated release from iron limitation, a deepening of remineralisation and decreased inorganic carbon export driven by cooler temperatures, we find that the carbon content of the glacial ocean can be sufficiently increased (317 Pg C) to explain the reduction in atmospheric and terrestrial carbon at the LGM (194 ± 2 and 330 ± 400 Pg C, respectively). Assuming an LGM-PI difference of 95 ppm pCO2, we find that 55 ppm can be attributed to the biological pump, 28 ppm to circulation changes and the remaining 12 ppm to solubility. The biogeochemical modifications also improve model-proxy agreement in export production, carbonate chemistry and dissolved oxygen fields. Thus, we find strong evidence that variations in the oceanic biological pump exert a primary control on the climate.

Plankton networks driving carbon export in the oligotrophic ocean

PubMed Central

Larhlimi, Abdelhalim; Roux, Simon; Darzi, Youssef; Audic, Stephane; Berline, Léo; Brum, Jennifer; Coelho, Luis Pedro; Espinoza, Julio Cesar Ignacio; Malviya, Shruti; Sunagawa, Shinichi; Dimier, Céline; Kandels-Lewis, Stefanie; Picheral, Marc; Poulain, Julie; Searson, Sarah; Stemmann, Lars; Not, Fabrice; Hingamp, Pascal; Speich, Sabrina; Follows, Mick; Karp-Boss, Lee; Boss, Emmanuel; Ogata, Hiroyuki; Pesant, Stephane; Weissenbach, Jean; Wincker, Patrick; Acinas, Silvia G.; Bork, Peer; de Vargas, Colomban; Iudicone, Daniele; Sullivan, Matthew B.; Raes, Jeroen; Karsenti, Eric; Bowler, Chris; Gorsky, Gabriel

2015-01-01

The biological carbon pump is the process by which CO2 is transformed to organic carbon via photosynthesis, exported through sinking particles, and finally sequestered in the deep ocean. While the intensity of the pump correlates with plankton community composition, the underlying ecosystem structure driving the process remains largely uncharacterised. Here we use environmental and metagenomic data gathered during the Tara Oceans expedition to improve our understanding of carbon export in the oligotrophic ocean. We show that specific plankton communities, from the surface and deep chlorophyll maximum, correlate with carbon export at 150 m and highlight unexpected taxa such as Radiolaria, alveolate parasites, as well as Synechococcus and their phages, as lineages most strongly associated with carbon export in the subtropical, nutrient-depleted, oligotrophic ocean. Additionally, we show that the relative abundance of just a few bacterial and viral genes can predict most of the variability in carbon export in these regions. PMID:26863193

Plankton networks driving carbon export in the oligotrophic ocean

NASA Astrophysics Data System (ADS)

2016-04-01

The biological carbon pump is the process by which CO2 is transformed to organic carbon via photosynthesis, exported through sinking particles, and finally sequestered in the deep ocean. While the intensity of the pump correlates with plankton community composition, the underlying ecosystem structure driving the process remains largely uncharacterized. Here we use environmental and metagenomic data gathered during the Tara Oceans expedition to improve our understanding of carbon export in the oligotrophic ocean. We show that specific plankton communities, from the surface and deep chlorophyll maximum, correlate with carbon export at 150 m and highlight unexpected taxa such as Radiolaria and alveolate parasites, as well as Synechococcus and their phages, as lineages most strongly associated with carbon export in the subtropical, nutrient-depleted, oligotrophic ocean. Additionally, we show that the relative abundance of a few bacterial and viral genes can predict a significant fraction of the variability in carbon export in these regions.

Implementation plan for Bolivian Mineral Exploration Fund

USGS Publications Warehouse

Kirkemo, Harold

1978-01-01

Bolivia ranks second among world producers of tin and antimony, and first in bismuth production. Mineral exports in 1975 were valued at $314.2 million, nearly 60 percent of the value of all exports, and petroleum product exports totalled nearly $157 million, or 30 percent of the total. Tin accounted for 58 percent of the total value of metallic mineral exports. The central government derived about 19 percent of its total tax revenues in 1975 from the mining sector. The mining sector consists of the large, medium, and small mining subsectors, a classification established by the government. Individual operations are referred to as large, medium, or small depending upon the subsector into which they are classified. All large mining enterprises are owned and operated by a government corporation, COMIBOL; the medium and small operations are privately owned. COMIBOL's exports in 1975 were valued at $171.8 million or 70 percent of the total mineral exports; the medium mines accounted for $55.5 million or 23 percent, and the small mines for $17.5 million or 7 percent of the total. The combination of high operating costs, low productivity, inadequate ore reserves, and insufficient risk capital for exploration and development has led to the realization that there is an urgent need to improve the situation for mining in Bolivia. Proposals are being studied to revise the tax code, a program is underway to evaluate selected mineral deposits for possible exploration and development, and programs are under consideration to encourage minerals exploration. A minerals exploration plan is proposed which would offer technical and financial aid to various segments in the minerals field. A program, estimated to cost between $2 million and $2.5 million annually, and to be operated by a new agency in the Ministry of Mining and Metallurgy, is outlined.

Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean

NASA Astrophysics Data System (ADS)

Iversen, Morten H.; Pakhomov, Evgeny A.; Hunt, Brian P. V.; van der Jagt, Helga; Wolf-Gladrow, Dieter; Klaas, Christine

2017-04-01

Salp fecal pellets are rich in organic matter and have been shown to sink at very high velocities. In recent years, salp abundances have been increasing in the Southern Ocean where they seem to be replacing krill as the dominant grazers on phytoplankton. As salps can form large swarms with high pellet production rates, it has been suggested that they will become increasingly important for the vertical export of particulate organic matter in the Southern Ocean. However, detailed studies combining both investigations of pellet production rates, turnover, and export are still needed in order to determine whether salp pellets are important for export ('sinkers') or recycling ('floaters') of organic matter. Our results suggest that pellets are produced at high rates in the upper few hundred meters of the water column. Although we observed high sinking velocities and low microbial degradation rates of the produced salp pellets, only about one third of the produced pellets were captured in sediment traps placed at 100 m and about 13% of the produced pellets were exported to sediment traps placed at 300 m. The high retention of these fast-settling pellets seems to be caused by break-up and loosening of the pellets, possibly by zooplankton and salps themselves. We measured 3-fold lower size-specific sinking velocities in loosened and fragmented compared to freshly produced intact pellets-. This enhanced the residence times (>1 day) of both small and large pellets in the upper water column. We postulate that the fragile nature of salp pellets make them more important for recycling of organic matter in the upper mesopelagic layer rather than as a conduit for export of particulate organic matter to the seafloor.

Pathways between primary production and fisheries yields of large marine ecosystems.

PubMed

Friedland, Kevin D; Stock, Charles; Drinkwater, Kenneth F; Link, Jason S; Leaf, Robert T; Shank, Burton V; Rose, Julie M; Pilskaln, Cynthia H; Fogarty, Michael J

2012-01-01

The shift in marine resource management from a compartmentalized approach of dealing with resources on a species basis to an approach based on management of spatially defined ecosystems requires an accurate accounting of energy flow. The flow of energy from primary production through the food web will ultimately limit upper trophic-level fishery yields. In this work, we examine the relationship between yield and several metrics including net primary production, chlorophyll concentration, particle-export ratio, and the ratio of secondary to primary production. We also evaluate the relationship between yield and two additional rate measures that describe the export of energy from the pelagic food web, particle export flux and mesozooplankton productivity. We found primary production is a poor predictor of global fishery yields for a sample of 52 large marine ecosystems. However, chlorophyll concentration, particle-export ratio, and the ratio of secondary to primary production were positively associated with yields. The latter two measures provide greater mechanistic insight into factors controlling fishery production than chlorophyll concentration alone. Particle export flux and mesozooplankton productivity were also significantly related to yield on a global basis. Collectively, our analyses suggest that factors related to the export of energy from pelagic food webs are critical to defining patterns of fishery yields. Such trophic patterns are associated with temperature and latitude and hence greater yields are associated with colder, high latitude ecosystems.

Pathways between Primary Production and Fisheries Yields of Large Marine Ecosystems

PubMed Central

Friedland, Kevin D.; Stock, Charles; Drinkwater, Kenneth F.; Link, Jason S.; Leaf, Robert T.; Shank, Burton V.; Rose, Julie M.; Pilskaln, Cynthia H.; Fogarty, Michael J.

2012-01-01

The shift in marine resource management from a compartmentalized approach of dealing with resources on a species basis to an approach based on management of spatially defined ecosystems requires an accurate accounting of energy flow. The flow of energy from primary production through the food web will ultimately limit upper trophic-level fishery yields. In this work, we examine the relationship between yield and several metrics including net primary production, chlorophyll concentration, particle-export ratio, and the ratio of secondary to primary production. We also evaluate the relationship between yield and two additional rate measures that describe the export of energy from the pelagic food web, particle export flux and mesozooplankton productivity. We found primary production is a poor predictor of global fishery yields for a sample of 52 large marine ecosystems. However, chlorophyll concentration, particle-export ratio, and the ratio of secondary to primary production were positively associated with yields. The latter two measures provide greater mechanistic insight into factors controlling fishery production than chlorophyll concentration alone. Particle export flux and mesozooplankton productivity were also significantly related to yield on a global basis. Collectively, our analyses suggest that factors related to the export of energy from pelagic food webs are critical to defining patterns of fishery yields. Such trophic patterns are associated with temperature and latitude and hence greater yields are associated with colder, high latitude ecosystems. PMID:22276100

Landscape controls on dissolved organic carbon export from watersheds of the British Columbia outer-coast

NASA Astrophysics Data System (ADS)

Giesbrecht, I.; Tank, S. E.; Frazer, G. W.; Gonzalez Arriola, S.; Korver, M.; Floyd, B. C.; Oliver, A. A.; Lertzman, K. P.

2016-12-01

Global models suggest that the Pacific Coastal Temperate Rainforest of North America (PCTR) exports significant quantities of dissolved organic carbon (DOC) to the coastal ocean. This aquatic flux from land to sea has implications for marine ecosystems and regional carbon budgets. However, DOC concentrations and flux estimates vary substantially across watersheds and drivers of spatial variation are poorly described for this region. For an outer-coast area of the PCTR, with among the highest per unit area DOC yields in the world (Oliver et al. in prep.), we describe and model landscape controls on DOC exports to the coastal ocean. In 2015 we collected three rounds of synoptic samples on Calvert Island, observing a nine-fold variation in DOC concentration (3.8 - 34.3 mg/L) across 59 watersheds that range in size from 0.26 to 21.12 km2 and reach a maximum elevation of 1012 m. We use standard ecosystem maps (Province of BC), LiDAR and other remote sensing data to measure watershed attributes. We use freshwater cation concentrations to explore geochemical signals of bedrock and surficial deposits that may be poorly represented by available geospatial data. We examine the role of topography, climate, waterbodies, geology and the local ecosystem mosaic in controlling DOC concentration and flux. An improved model of spatial controls on freshwater DOC export from the outer-coast of the PCTR will inform regional carbon modeling efforts and enhance our understanding of ecosystem processes at the coastal margin.

Contrasting nitrogen and phosphorus budgets in urban watersheds and implications for managing urban water pollution

PubMed Central

Janke, Benjamin D.; Nidzgorski, Daniel A.; Millet, Dylan B.; Baker, Lawrence A.

2017-01-01

Managing excess nutrients remains a major obstacle to improving ecosystem service benefits of urban waters. To inform more ecologically based landscape nutrient management, we compared watershed inputs, outputs, and retention for nitrogen (N) and phosphorus (P) in seven subwatersheds of the Mississippi River in St. Paul, Minnesota. Lawn fertilizer and pet waste dominated N and P inputs, respectively, underscoring the importance of household actions in influencing urban watershed nutrient budgets. Watersheds retained only 22% of net P inputs versus 80% of net N inputs (watershed area-weighted averages, where net inputs equal inputs minus biomass removal) despite relatively low P inputs. In contrast to many nonurban watersheds that exhibit high P retention, these urban watersheds have high street density that enhanced transport of P-rich materials from landscapes to stormwater. High P exports in storm drainage networks and yard waste resulted in net P losses in some watersheds. Comparisons of the N/P stoichiometry of net inputs versus storm drain exports implicated denitrification or leaching to groundwater as a likely fate for retained N. Thus, these urban watersheds exported high quantities of N and P, but via contrasting pathways: P was exported primarily via stormwater runoff, contributing to surface water degradation, whereas N losses additionally contribute to groundwater pollution. Consequently, N management and P management require different strategies, with N management focusing on reducing watershed inputs and P management also focusing on reducing P movement from vegetated landscapes to streets and storm drains. PMID:28373560

Nuclear export receptor CRM1 recognizes diverse conformations in nuclear export signals.

PubMed

Fung, Ho Yee Joyce; Fu, Szu-Chin; Chook, Yuh Min

2017-03-10

Nuclear export receptor CRM1 binds highly variable nuclear export signals (NESs) in hundreds of different cargoes. Previously we have shown that CRM1 binds NESs in both polypeptide orientations (Fung et al., 2015). Here, we show crystal structures of CRM1 bound to eight additional NESs which reveal diverse conformations that range from loop-like to all-helix, which occupy different extents of the invariant NES-binding groove. Analysis of all NES structures show 5-6 distinct backbone conformations where the only conserved secondary structural element is one turn of helix that binds the central portion of the CRM1 groove. All NESs also participate in main chain hydrogen bonding with human CRM1 Lys568 side chain, which acts as a specificity filter that prevents binding of non-NES peptides. The large conformational range of NES backbones explains the lack of a fixed pattern for its 3-5 hydrophobic anchor residues, which in turn explains the large array of peptide sequences that can function as NESs.

From solid to liquid: assessing the release of organic matter into soil solution in response to land-use conversion in Brazilian Oxisols

NASA Astrophysics Data System (ADS)

James, Jason; Gross, Cole; Dwivedi, Pranjal; Bernardi, Rodolpho; Guerrini, Irae; Harrison, Rob; Butman, David

2017-04-01

Recent advances in freshwater research indicate that roughly double the quantity of carbon is exported from soils to streams and rivers than was previously estimated, and that the age of carbon exported from major rivers globally increases with greater human disturbance in the watershed. This implies that human land-use can release old, previously mineral-associated C into solution with subsequent export to groundwater and ultimately freshwater systems where terrestrial organic matter is either mineralized to CO2, stored in aquatic sediments, or exported to the ocean. Consequently, it is important to understand the mechanisms that cause the release of SOM that is mineral-bound into solution in response to human disturbance and land-use change. Research methods have been established to examine both the fast turnover, dissolved pool of soil organic matter (SOM), as well as the slow turnover, mineral-associated pool. However, to better characterize the response of the total SOM pool to disturbance, it is necessary to understand the interactions between these functional pools by examining them both simultaneously. This study seeks to examine the interaction between dissolved organic matter (DOM) and bulk SOM throughout the soil profile in response to conversion of Brazilian Cerrado (savannah forest) to Eucalyptus plantation forest on the same soil type. The water-extractable organic matter was obtained from soil samples down to 150 cm, characterized using fluorescence and NMR spectroscopy, and carbon-dated. Simultaneously, bulk mineral soil samples were analyzed for microbial biomass, carbon content and age, and characterized using Fourier Transform Infrared Spectroscopy. SOM spectra were obtained by washing subsamples with sodium hypochlorite and subtracting the subsequent mineral matrix spectra from bulk soil spectra. Preliminary results show that microbial biomass decreases much more quickly with depth than DOM, suggesting that C released into solution from deeper horizons may be less likely to be intercepted, and thus preferentially leached to groundwater. Native Cerrado forests had substantially more roots compared to Eucalyptus, and also released substantially larger quantities of DOM from their O horizons. Processes operating at the interface between solid and liquid, terrestrial and aquatic are a key unknown in the global carbon cycle. This research permits a unique snapshot into the relationship between DOM and SOM and the response of these pools to land-use change in Brazil.

Evolution of a Lowland Karst Landscape; A Mass-Balance Approach

NASA Astrophysics Data System (ADS)

Chamberlin, C.; Heffernan, J. B.; Cohen, M. J.; Quintero, C.; Pain, A.

2016-12-01

Karst landscapes are highly soluble, and are vulnerable to biological acid production as a major driving factor in their evolution. Big Cypress National Park (BICY) is a low-lying karst landscape in southern Florida displaying a distinctive morphology of isolated depressions likely influenced by biology. The goal of this study is to constrain timescales of landform development in BICY. This question was addressed through the construction of landscape-scale elemental budgets for both calcium and phosphorus. Precipitation and export fluxes were calculated using available chemistry and hydrology data, and stocks were calculated from a combination of existing data, field measurements, and laboratory chemical analysis. Estimates of expected mass export given no biological acid production and given an equivalent production of 100% of GPP were compared with observed rates. Current standing stocks of phosphorus are dominated by a large soil pool, and contain 500 Gg P. Inputs are largely dominated by precipitation, and 8000 years are necessary to accumulate standing stocks of phosphorus given modern fluxes. Calcium flux is vastly dominated by dissolution of the limestone bedrock, and though some calcium is retained in the soil, most is exported. Using LiDAR generated estimates of volume loss across the landscape and current export rates, an estimated 15,000 years would be necessary to create the modern landscape. Both of these estimates indicate that the BICY landscape is geologically very young. The different behaviors of these elements (calcium is largely exported, while phosphorus is largely retained) lend additional confidence to estimates of denudation rates of the landscape. These estimates can be even closer reconciled if calcium redistribution over the landscape is allowed for. This estimate is compared to the two bounding conditions for biological weathering to indicate a likely level of biological importance to landscape development in this system.

Estimating the Cross-Shelf Export of Riverine Materials: Part 1. General Relationships From an Idealized Numerical Model

NASA Astrophysics Data System (ADS)

Izett, Jonathan G.; Fennel, Katja

2018-02-01

Rivers deliver large amounts of terrestrially derived materials (such as nutrients, sediments, and pollutants) to the coastal ocean, but a global quantification of the fate of this delivery is lacking. Nutrients can accumulate on shelves, potentially driving high levels of primary production with negative consequences like hypoxia, or be exported across the shelf to the open ocean where impacts are minimized. Global biogeochemical models cannot resolve the relatively small-scale processes governing river plume dynamics and cross-shelf export; instead, river inputs are often parameterized assuming an "all or nothing" approach. Recently, Sharples et al. (2017), https://doi.org/10.1002/2016GB005483 proposed the SP number—a dimensionless number relating the estimated size of a plume as a function of latitude to the local shelf width—as a simple estimator of cross-shelf export. We extend their work, which is solely based on theoretical and empirical scaling arguments, and address some of its limitations using a numerical model of an idealized river plume. In a large number of simulations, we test whether the SP number can accurately describe export in unforced cases and with tidal and wind forcings imposed. Our numerical experiments confirm that the SP number can be used to estimate export and enable refinement of the quantitative relationships proposed by Sharples et al. We show that, in general, external forcing has only a weak influence compared to latitude and derive empirical relationships from the results of the numerical experiments that can be used to estimate riverine freshwater export to the open ocean.

Climate change and dissolved organic carbon export to the Gulf of Maine

USGS Publications Warehouse

Huntington, Thomas G.; Balch, William M.; Aiken, George R.; Sheffield, Justin; Luo, Lifeng; Roesler, Collin S.; Camill, Philip

2016-01-01

Ongoing climate change is affecting the concentration, export (flux), and timing of dissolved organic carbon (DOC) exported to the Gulf of Maine (GoM) through changes in hydrologic regime. DOC export was calculated for water years 1950 through 2013 for 20 rivers and for water years 1930 through 2013 for 14 rivers draining to the GoM. DOC export was also estimated for the 21st century based on climate and hydrologic modeling in a previously published study. DOC export was calculated by using the regression model LOADEST to fit seasonally adjusted concentration discharge (C-Q) relations. Our results are an analysis of the sensitivity of DOC export to changes in hydrologic conditions over time since land cover and vegetation were held constant over time. Despite large interannual variability, all rivers had increasing DOC export during winter and these trends were significant (p < 0.05) in 10 out of 20 rivers for 1950 to 2013 and in 13 out of 14 rivers for 1930 to 2013. All rivers also had increasing annual export of DOC although fewer trends were statistically significant than for winter export. Projections for DOC export during the 21st century were variable depending on the climate model and greenhouse gas emission scenario that affected future river discharge through effects on precipitation and evapotranspiration. The most consistent result was a significant increase in DOC export in winter in all model-by-emission scenarios. DOC export was projected to decrease during the summer in all model-by-emission scenarios, with statistically significant decreases in half of the scenarios.

Water quality and quantity in the context of large-scale cellulosic biofuel production in the Mississippi-Atchafalaya River Basin

NASA Astrophysics Data System (ADS)

VanLoocke, A.; Bernacchi, C. J.; Twine, T. E.; Kucharik, C. J.

2012-12-01

Numerous socio-economic and environmental pressures have driven the need to increase domestic renewable energy production in the Midwest. The primary attempt at addressing this need has been to use maize; however, the leaching of residual nitrate from maize fertilizer into runoff drives the formation of the Gulf of Mexico hypoxic or "Dead" zone which can have significant environmental impacts on the marine ecosystems. As a result of the threat to benthic organisms and fisheries in this region, The Mississippi Basin/Gulf of Mexico Task Force has set in place goals to reduce the size of the hypoxic zone from the current size of ~ 20,000 km2 to < 5000 km2 by the year. It is predicted that annual dissolved inorganic nitrate (DIN) export would have to decrease by 30 to 55% to meet this goal. An alternative option to meet the renewable energy needs while reducing the environmental impacts associated with DIN export is to produce high-yielding, low fertilizer input perennial grasses such as switchgrass and miscanthus. Miscanthus and switchgrass have been shown to greatly reduce nitrate leaching at the plot scale, even during the establishment phase. This reduction in leaching is attributed to the perennial nature and the efficient recycling of nutrients via nutrient translocation. While these feedstocks are able to achieve higher productivity than maize grain with fewer inputs, they require more water, presenting the potential for environmental impacts on regional hydrologic cycle, including reductions in streamflow. The goal of this research is to determine the change in streamflow in the Mississippi-Atchafalaya River Basin (MARB) and the export of nitrogen from fertilizer to the Gulf of Mexico. To address this goal, we adapted a vegetation model capable of simulating the biogeochemistry of current crops as well as miscanthus and switchgrass, the Integrated Biosphere Simulator - agricultural version (Agro-IBIS) and coupled it with a hydrology model capable of simulating streamflow and nitrogen export, the Terrestrial Hydrology Model with Biogeochemistry. Simulations were conducted at varying fertilizer application rates and fraction coverages of miscanthus and switchgrass across the MARB. Data analysis indicated that there were reductions in runoff and streamflow throughout the MARB, with the largest differences occurring in drier portions of the regions. However differences in streamflow were only statistically resolved when miscanthus production was above 25% coverage and switchgrass above 35%. Compared to streamflow, statistically significant reductions in nitrogen export occurred at lower percent coverage, with unfertilized miscanthus having significant reductions at 10% and switchgrass at 25% coverage respectively, however this effect was smaller at higher fertilizer application rates. These results indicate that, given targeted management strategies, there is potential for miscanthus and switchgrass to provide key ecosystem services by reducing the export of DIN, while avoiding hydrologic impacts of reduced streamflow.

From salmon to shad: Shifting sources of marine-derived nutrients in the Columbia River Basin

USGS Publications Warehouse

Haskell, Craig A.

2018-01-01

Like Pacific salmon (Oncorhynchus spp.), nonnative American shad (Alosa sapidissima) have the potential to convey large quantities of nutrients between the Pacific Ocean and freshwater spawning areas in the Columbia River Basin (CRB). American shad are now the most numerous anadromous fish in the CRB, yet the magnitude of the resulting nutrient flux owing to the shift from salmon to shad is unknown. Nutrient flux models revealed that American shad conveyed over 15,000 kg of nitrogen (N) and 3,000 kg of phosphorus (P) annually to John Day Reservoir, the largest mainstem reservoir in the lower Columbia River. Shad were net importers of N, with juveniles and postspawners exporting just 31% of the N imported by adults. Shad were usually net importers of P, with juveniles and postspawners exporting 46% of the P imported by adults on average. American shad contributed <0.2% of the total annual P load into John Day Reservoir, but during June when most adult shad are migrating into John Day Reservoir, they contributed as much as 2.0% of the P load. Nutrient inputs by American shad were similar to current but far less than historical inputs of Pacific salmon owing to their smaller size. Given the relatively high background P levels and low retention times in lower Columbia River reservoirs, it is unlikely that shad marine-derived nutrients affect nutrient balances or food web productivity through autotrophic pathways. However, a better understanding of shad spawning aggregations in the CRB is needed.

Runoff sources and flowpaths in a partially burned, upland boreal catchment underlain by permafrost

USGS Publications Warehouse

Koch, Joshua C.; Kikuchi, Colin P.; Wickland, Kimberly P.; Schuster, Paul

2014-01-01

Boreal soils in permafrost regions contain vast quantities of frozen organic material that is released to terrestrial and aquatic environments via subsurface flowpaths as permafrost thaws. Longer flowpaths may allow chemical reduction of solutes, nutrients, and contaminants, with implications for greenhouse gas emissions and aqueous export. Predicting boreal catchment runoff is complicated by soil heterogeneities related to variability in active layer thickness, soil type, fire history, and preferential flow potential. By coupling measurements of permeability, infiltration potential, and water chemistry with a stream chemistry end member mixing model, we tested the hypothesis that organic soils and burned slopes are the primary sources of runoff, and that runoff from burned soils is greater due to increased hydraulic connectivity. Organic soils were more permeable than mineral soils, and 25% of infiltration moved laterally upon reaching the organic-mineral soil boundary on unburned hillslopes. A large portion of the remaining water infiltrated into deeper, less permeable soils. In contrast, burned hillslopes displayed poorly defined soil horizons, allowing rapid, mineral-rich runoff through preferential pathways at various depths. On the catchment scale, mineral/organic runoff ratios averaged 1.6 and were as high as 5.2 for an individual storm. Our results suggest that burned soils are the dominant source of water and solutes reaching the stream in summer, whereas unburned soils may provide longer term storage and residence times necessary for production of anaerobic compounds. These results are relevant to predicting how boreal catchment drainage networks and stream export will evolve given continued warming and altered fire regimes.

The biogeochemistry of carbon across a gradient of streams and rivers within the Congo Basin

NASA Astrophysics Data System (ADS)

Mann, P. J.; Spencer, R. G. M.; Dinga, B. J.; Poulsen, J. R.; Hernes, P. J.; Fiske, G.; Salter, M. E.; Wang, Z. A.; Hoering, K. A.; Six, J.; Holmes, R. M.

2014-04-01

Dissolved organic carbon (DOC) and inorganic carbon (DIC, pCO2), lignin biomarkers, and theoptical properties of dissolved organic matter (DOM) were measured in a gradient of streams and rivers within the Congo Basin, with the aim of examining how vegetation cover and hydrology influences the composition and concentration of fluvial carbon (C). Three sampling campaigns (February 2010, November 2010, and August 2011) spanning 56 sites are compared by subbasin watershed land cover type (savannah, tropical forest, and swamp) and hydrologic regime (high, intermediate, and low). Land cover properties predominately controlled the amount and quality of DOC, chromophoric DOM (CDOM) and lignin phenol concentrations (∑8) exported in streams and rivers throughout the Congo Basin. Higher DIC concentrations and changing DOM composition (lower molecular weight, less aromatic C) during periods of low hydrologic flow indicated shifting rapid overland supply pathways in wet conditions to deeper groundwater inputs during drier periods. Lower DOC concentrations in forest and swamp subbasins were apparent with increasing catchment area, indicating enhanced DOC loss with extended water residence time. Surface water pCO2 in savannah and tropical forest catchments ranged between 2,600 and 11,922 µatm, with swamp regions exhibiting extremely high pCO2 (10,598-15,802 µatm), highlighting their potential as significant pathways for water-air efflux. Our data suggest that the quantity and quality of DOM exported to streams and rivers are largely driven by terrestrial ecosystem structure and that anthropogenic land use or climate change may impact fluvial C composition and reactivity, with ramifications for regional C budgets and future climate scenarios.

Mercury export from the Yukon River Basin and potential response to a changing climate

USGS Publications Warehouse

Schuster, P. F.; Striegl, Robert G.; Aiken, G. R.; Krabbenhoft, D. P.; Dewild, J. F.; Butler, K.; Kamark, B.; Dornblaser, M.

2011-01-01

We measured mercury (Hg) concentrations and calculated export and yield from the Yukon River Basin (YRB) to quantify Hg flux from a large, permafrost-dominated, high-latitude watershed. Exports of Hg averaged 4400 kg Hg yr–1. The average annual yield for the YRB during the study period was 5.17 μg m–2 yr–1, which is 3–32 times more than Hg yields reported for 8 other major northern hemisphere river basins. The vast majority (90%) of Hg export is associated with particulates. Half of the annual export of Hg occurred during the spring with about 80% of 34 samples exceeding the U.S. EPA Hg standard for adverse chronic effects to biota. Dissolved and particulate organic carbon exports explained 81% and 50%, respectively, of the variance in Hg exports, and both were significantly (p < 0.001) correlated with water discharge. Recent measurements indicate that permafrost contains a substantial reservoir of Hg. Consequently, climate warming will likely accelerate the mobilization of Hg from thawing permafrost increasing the export of organic carbon associated Hg and thus potentially exacerbating the production of bioavailable methylmercury from permafrost-dominated northern river basins.

Mercury export from the Yukon River Basin and potential response to a changing climate

USGS Publications Warehouse

Schuster, Paul F.; Striegl, Robert G.; Aiken, George R.; Krabbenhoft, David P.; DeWild, John F.; Butler, Kenna D.; Kamark, Ben; Dornblaser, Mark

2011-01-01

We measured mercury (Hg) concentrations and calculated export and yield from the Yukon River Basin (YRB) to quantify Hg flux from a large, permafrost-dominated, high-latitude watershed. Exports of Hg averaged 4400 kg Hg yr-1. The average annual yield for the YRB during the study period was 5.17 μg m-2 yr-1, which is 3–32 times more than Hg yields reported for 8 other major northern hemisphere river basins. The vast majority (90%) of Hg export is associated with particulates. Half of the annual export of Hg occurred during the spring with about 80% of 34 samples exceeding the U.S. EPA Hg standard for adverse chronic effects to biota. Dissolved and particulate organic carbon exports explained 81% and 50%, respectively, of the variance in Hg exports, and both were significantly (p < 0.001) correlated with water discharge. Recent measurements indicate that permafrost contains a substantial reservoir of Hg. Consequently, climate warming will likely accelerate the mobilization of Hg from thawing permafrost increasing the export of organic carbon associated Hg and thus potentially exacerbating the production of bioavailable methylmercury from permafrost-dominated northern river basins.

Factors influencing export of dissolved inorganic nitrogen by major rivers: A new, seasonal, spatially explicit, global model

EPA Science Inventory

Substantial effort has focused on understanding spatial variation in dissolved inorganic nitrogen (DIN) export to the coastal zone and specific basins have been studied in depth. Much less is known, however, about seasonal patterns and controls of coastal DIN delivery across larg...

Image Classification of Ribbed Smoked Sheet using Learning Vector Quantization

NASA Astrophysics Data System (ADS)

Rahmat, R. F.; Pulungan, A. F.; Faza, S.; Budiarto, R.

2017-01-01

Natural rubber is an important export commodity in Indonesia, which can be a major contributor to national economic development. One type of rubber used as rubber material exports is Ribbed Smoked Sheet (RSS). The quantity of RSS exports depends on the quality of RSS. RSS rubber quality has been assigned in SNI 06-001-1987 and the International Standards of Quality and Packing for Natural Rubber Grades (The Green Book). The determination of RSS quality is also known as the sorting process. In the rubber factones, the sorting process is still done manually by looking and detecting at the levels of air bubbles on the surface of the rubber sheet by naked eyes so that the result is subjective and not so good. Therefore, a method is required to classify RSS rubber automatically and precisely. We propose some image processing techniques for the pre-processing, zoning method for feature extraction and Learning Vector Quantization (LVQ) method for classifying RSS rubber into two grades, namely RSS1 and RSS3. We used 120 RSS images as training dataset and 60 RSS images as testing dataset. The result shows that our proposed method can give 89% of accuracy and the best perform epoch is in the fifteenth epoch.

Substantial nitrogen pollution embedded in international trade

NASA Astrophysics Data System (ADS)

Oita, Azusa; Malik, Arunima; Kanemoto, Keiichiro; Geschke, Arne; Nishijima, Shota; Lenzen, Manfred

2016-02-01

Anthropogenic emissions of reactive nitrogen to the atmosphere and water bodies can damage human health and ecosystems. As a measure of a nation’s contribution to this potential damage, a country’s nitrogen footprint has been defined as the quantity of reactive nitrogen emitted during the production, consumption and transportation of commodities consumed within that country, whether those commodities are produced domestically or internationally. Here we use global emissions databases, a global nitrogen cycle model, and a global input-output database of domestic and international trade to calculate the nitrogen footprints for 188 countries as the sum of emissions of ammonia, nitrogen oxides and nitrous oxide to the atmosphere, and of nitrogen potentially exportable to water bodies. Per-capita footprints range from under 7 kg N yr-1 in some developing countries to over 100 kg N yr-1 in some wealthy nations. Consumption in China, India, the United States and Brazil is responsible for 46% of global emissions. Roughly a quarter of the global nitrogen footprint is from commodities that were traded across country borders. The main net exporters have significant agricultural, food and textile exports, and are often developing countries, whereas important net importers are almost exclusively developed economies. We conclude that substantial local nitrogen pollution is driven by demand from consumers in other countries.

The Chinese import ban and its impact on global plastic waste trade

PubMed Central

Wang, Shunli

2018-01-01

The rapid growth of the use and disposal of plastic materials has proved to be a challenge for solid waste management systems with impacts on our environment and ocean. While recycling and the circular economy have been touted as potential solutions, upward of half of the plastic waste intended for recycling has been exported to hundreds of countries around the world. China, which has imported a cumulative 45% of plastic waste since 1992, recently implemented a new policy banning the importation of most plastic waste, begging the question of where the plastic waste will go now. We use commodity trade data for mass and value, region, and income level to illustrate that higher-income countries in the Organization for Economic Cooperation have been exporting plastic waste (70% in 2016) to lower-income countries in the East Asia and Pacific for decades. An estimated 111 million metric tons of plastic waste will be displaced with the new Chinese policy by 2030. As 89% of historical exports consist of polymer groups often used in single-use plastic food packaging (polyethylene, polypropylene, and polyethylene terephthalate), bold global ideas and actions for reducing quantities of nonrecyclable materials, redesigning products, and funding domestic plastic waste management are needed. PMID:29938223

Passive phloem loading and long-distance transport in a synthetic tree-on-a-chip.

PubMed

Comtet, Jean; Jensen, Kaare H; Turgeon, Robert; Stroock, Abraham D; Hosoi, A E

2017-03-20

Vascular plants rely on differences in osmotic pressure to export sugars from regions of synthesis (mature leaves) to sugar sinks (roots, fruits). In this process, known as Münch pressure flow, the loading of sugars from photosynthetic cells to the export conduit (the phloem) is crucial, as it sets the pressure head necessary to power long-distance transport. Whereas most herbaceous plants use active mechanisms to increase phloem sugar concentration above that of the photosynthetic cells, in most tree species, for which transport distances are largest, loading seems, counterintuitively, to occur by means of passive symplastic diffusion from the mesophyll to the phloem. Here, we use a synthetic microfluidic model of a passive loader to explore the non-linear dynamics that arise during export and determine the ability of passive loading to drive long-distance transport. We first demonstrate that in our device, the phloem concentration is set by the balance between the resistances to diffusive loading from the source and convective export through the phloem. Convection-limited export corresponds to classical models of Münch transport, where the phloem concentration is close to that of the source; in contrast, diffusion-limited export leads to small phloem concentrations and weak scaling of flow rates with hydraulic resistance. We then show that the effective regime of convection-limited export is predominant in plants with large transport resistances and low xylem pressures. Moreover, hydrostatic pressures developed in our synthetic passive loader can reach botanically relevant values as high as 10 bars. We conclude that passive loading is sufficient to drive long-distance transport in large plants, and that trees are well suited to take full advantage of passive phloem loading strategies.

Middle East fuel supply & gas exports for power generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchell, G.K.; Newendorp, T.

1995-12-31

The Middle East countries that border on, or are near, the Persian Gulf hold over 65% of the world`s estimated proven crude oil reserves and 32% of the world`s estimated proven natural gas reserves. In fact, approximately 5% of the world`s total proven gas reserves are located in Qatar`s offshore North Field. This large natural gas/condensate field is currently under development to supply three LNG export projects, as well as a sub-sea pipeline proposal to export gas to Pakistan. The Middle East will continue to be a major source of crude oil and oil products to world petroleum markets, includingmore » fuel for existing and future base load, intermediate cycling and peaking electric generation plants. In addition, as the Persian Gulf countries turn their attention to exploiting their natural gas resources, the fast-growing need for electricity in the Asia-Pacific and east Africa areas offers a potential market for both pipeline and LNG export opportunities to fuel high efficiency, gas-fired combustion turbine power plants. Mr. Mitchell`s portion of this paper will discuss the background, status and timing of several Middle Eastern gas export projects that have been proposed. These large gas export projects are difficult and costly to develop and finance. Consequently, any IPP developers that are considering gas-fired projects which require Mid-East LNG as a fuel source, should understand the numerous sources and timing to securing project debt, loan terms and conditions, and, restrictions/credit rating issues associated with securing financing for these gas export projects. Mr. Newendorp`s section of the paper will cover the financing aspects of these projects, providing IPP developers with additional considerations in selecting the primary fuel supply for an Asian-Pacific or east African electric generation project.« less

Chesapeake Bay nitrogen fluxes derived from a land-estuarine ocean biogeochemical modeling system: Model description, evaluation, and nitrogen budgets.

PubMed

Feng, Yang; Friedrichs, Marjorie A M; Wilkin, John; Tian, Hanqin; Yang, Qichun; Hofmann, Eileen E; Wiggert, Jerry D; Hood, Raleigh R

2015-08-01

The Chesapeake Bay plays an important role in transforming riverine nutrients before they are exported to the adjacent continental shelf. Although the mean nitrogen budget of the Chesapeake Bay has been previously estimated from observations, uncertainties associated with interannually varying hydrological conditions remain. In this study, a land-estuarine-ocean biogeochemical modeling system is developed to quantify Chesapeake riverine nitrogen inputs, within-estuary nitrogen transformation processes and the ultimate export of nitrogen to the coastal ocean. Model skill was evaluated using extensive in situ and satellite-derived data, and a simulation using environmental conditions for 2001-2005 was conducted to quantify the Chesapeake Bay nitrogen budget. The 5 year simulation was characterized by large riverine inputs of nitrogen (154 × 10 9  g N yr -1 ) split roughly 60:40 between inorganic:organic components. Much of this was denitrified (34 × 10 9  g N yr -1 ) and buried (46 × 10 9  g N yr -1 ) within the estuarine system. A positive net annual ecosystem production for the bay further contributed to a large advective export of organic nitrogen to the shelf (91 × 10 9  g N yr -1 ) and negligible inorganic nitrogen export. Interannual variability was strong, particularly for the riverine nitrogen fluxes. In years with higher than average riverine nitrogen inputs, most of this excess nitrogen (50-60%) was exported from the bay as organic nitrogen, with the remaining split between burial, denitrification, and inorganic export to the coastal ocean. In comparison to previous simulations using generic shelf biogeochemical model formulations inside the estuary, the estuarine biogeochemical model described here produced more realistic and significantly greater exports of organic nitrogen and lower exports of inorganic nitrogen to the shelf.

Chesapeake Bay nitrogen fluxes derived from a land‐estuarine ocean biogeochemical modeling system: Model description, evaluation, and nitrogen budgets

PubMed Central

Friedrichs, Marjorie A. M.; Wilkin, John; Tian, Hanqin; Yang, Qichun; Hofmann, Eileen E.; Wiggert, Jerry D.; Hood, Raleigh R.

2015-01-01

Abstract The Chesapeake Bay plays an important role in transforming riverine nutrients before they are exported to the adjacent continental shelf. Although the mean nitrogen budget of the Chesapeake Bay has been previously estimated from observations, uncertainties associated with interannually varying hydrological conditions remain. In this study, a land‐estuarine‐ocean biogeochemical modeling system is developed to quantify Chesapeake riverine nitrogen inputs, within‐estuary nitrogen transformation processes and the ultimate export of nitrogen to the coastal ocean. Model skill was evaluated using extensive in situ and satellite‐derived data, and a simulation using environmental conditions for 2001–2005 was conducted to quantify the Chesapeake Bay nitrogen budget. The 5 year simulation was characterized by large riverine inputs of nitrogen (154 × 109 g N yr−1) split roughly 60:40 between inorganic:organic components. Much of this was denitrified (34 × 109 g N yr−1) and buried (46 × 109 g N yr−1) within the estuarine system. A positive net annual ecosystem production for the bay further contributed to a large advective export of organic nitrogen to the shelf (91 × 109 g N yr−1) and negligible inorganic nitrogen export. Interannual variability was strong, particularly for the riverine nitrogen fluxes. In years with higher than average riverine nitrogen inputs, most of this excess nitrogen (50–60%) was exported from the bay as organic nitrogen, with the remaining split between burial, denitrification, and inorganic export to the coastal ocean. In comparison to previous simulations using generic shelf biogeochemical model formulations inside the estuary, the estuarine biogeochemical model described here produced more realistic and significantly greater exports of organic nitrogen and lower exports of inorganic nitrogen to the shelf. PMID:27668137

76 FR 45227 - Initiation of Antidumping and Countervailing Duty Administrative Reviews, Requests for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-28

... antidumping duty orders on Certain Polyester Staple Fiber from the People's Republic of China with respect to... Certain Polyester Staple Fiber from the People's Republic of China with respect to two exporters and on... exporter. Period to be reviewed Antidumping Duty Proceedings Japan: Certain Large Diameter Carbon and Alloy...

10 CFR 110.42 - Export licensing criteria.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) through (9) of appendix A to this part, when exported separately from the items described in paragraphs (1... in the United States. (9)(i) Except as provided in paragraph (a)(9)(ii) of this section, with respect... ongoing and planned experiments and isotope production to be conducted in the reactor without a large...

10 CFR 110.42 - Export licensing criteria.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) through (9) of appendix A to this part, when exported separately from the items described in paragraphs (1... in the United States. (9)(i) Except as provided in paragraph (a)(9)(ii) of this section, with respect... ongoing and planned experiments and isotope production to be conducted in the reactor without a large...

Recent evolution of China's virtual water trade: analysis of selected crops and considerations for policy

NASA Astrophysics Data System (ADS)

Shi, J.; Liu, J.; Pinter, L.

2013-09-01

China has dramatically increased its virtual water import unconsciously for recent years. Many studies have focused on the quantity of traded virtual water but very few go into analysing geographic distribution and the properties of China's virtual water trade network. This paper provides a calculation and analysis of the crop-related virtual water trade network of China based on 27 major primary crops between 1986 and 2009. The results show that China is a net importer of virtual water from water-abundant areas of North and South America, and a net virtual water exporter to water-stressed areas of Asia, Africa, and Europe. Virtual water import is far larger than virtual water export and in both import and export a small number of trade partners control the supply chain. Grain crops are the major contributors to virtual water trade, and among grain crops soybeans, mostly imported from the US, Brazil and Argentina are the most significant. As crop yield and crop water productivity in North and South America are generally higher than those in Asia and Africa, the effect of China's crop-related virtual water trade positively contributes to optimizing crop water use efficiency at the global scale. In order to mitigate water scarcity and secure the food supply, virtual water should be actively incorporated into national water management strategies. From the national perspective, China should reduce the export and increase the import of water-intensive crops. But the sources of virtual water import need to be further diversified to reduce supply chain risks and increase resilience.

Function of the conserved FHIPEP domain of the flagellar type III export apparatus, protein FlhA.

PubMed

Barker, Clive S; Inoue, Tomoharu; Meshcheryakova, Irina V; Kitanobo, Seiya; Samatey, Fadel A

2016-04-01

The Type III flagellar protein export apparatus of bacteria consists of five or six membrane proteins, notably FlhA, which controls the export of other proteins and is homologous to the large family of FHIPEP export proteins. FHIPEP proteins contain a highly-conserved cytoplasmic domain. We mutagenized the cloned Salmonella flhA gene for the 692 amino acid FlhA, changing a single, conserved amino acid in the 68-amino acid FHIPEP region. Fifty-two mutations at 30 positions mostly led to loss of motility and total disappearance of microscopically visible flagella, also Western blot protein/protein hybridization showed no detectable export of hook protein and flagellin. There were two exceptions: a D199A mutant strain, which produced short-stubby flagella; and a V151L mutant strain, which did not produce flagella and excreted mainly un-polymerized hook protein. The V151L mutant strain also exported a reduced amount of hook-cap protein FlgD, but when grown with exogenous FlgD it produced polyhooks and polyhook-filaments. A suppressor mutant in the cytoplasmic domain of the export apparatus membrane protein FlhB rescued export of hook-length control protein FliK and facilitated growth of full-length flagella. These results suggested that the FHIPEP region is part of the gate regulating substrate entry into the export apparatus pore. © 2015 John Wiley & Sons Ltd.

Export of Strongly Diluted Greenland Meltwater From a Major Glacial Fjord

NASA Astrophysics Data System (ADS)

Beaird, Nicholas L.; Straneo, Fiammetta; Jenkins, William

2018-05-01

The Greenland Ice Sheet has been, and will continue, losing mass at an accelerating rate. The influence of this anomalous meltwater discharge on the regional and large-scale ocean could be considerable but remains poorly understood. This uncertainty is in part a consequence of challenges in observing water mass transformation and meltwater spreading in coastal Greenland. Here we use tracer observations that enable unprecedented quantification of the export, mixing, and vertical distribution of meltwaters leaving one of Greenland's major glacial fjords. We find that the primarily subsurface meltwater input results in the upwelling of the deep fjord waters and an export of a meltwater/deepwater mixture that is 30 times larger than the initial meltwater release. Using these tracer data, the vertical structure of Greenland's summer meltwater export is defined for the first time showing that half the meltwater export occurs below 65 m.

[Report on notifications pursuant to Section 21 German Transfusion Act for 2007].

PubMed

Henseler, O; Heiden, M; Haschberger, B; Hesse, J; Seitz, R

2009-07-01

The present report contains the data collected in 2007, pursuant to Section 21 Transfusionsgesetz (German Transfusion Act), and an analysis of the supply situation over the past eight years. The recording of the data by online reporting is in the meantime well established and generally accepted. As in previous years, all blood donation centers located in Germany transmitted data on the collection, manufacture, import and export of blood components for transfusion, so that meaningful data are available. According to these data, a total of 6.7 million blood collections were performed in 2007. The number of whole blood donations was at the level of previous years, with 4.7 million, whereas the number of apheresis donations rose again, to 1.9 million. The portion of autologous blood collections accounts for only 1.1% and thus continues to decline. Since 2003, the number of red blood cell concentrates prepared has been a constant 4.5 million transfusion units. The decrease in the portion of decay of red blood cell concentrates on the user side is particularly good news. In 2000, it accounted for 5% and in 2007, it was just above 3%, referred to the total quantity of data reported as transfused and decayed. The manufacture of platelet concentrates rose from 366,000 to 480,000 transfusion units between 2003 and 2007. The production of therapeutic single plasmas also markedly increased in 2007 compared with previous years, accounting for 1.2 million transfusion units. In 2007, 2.2 million liters of plasma for fractionation were collected in Germany. This trend went hand in hand with the increasing number of apheresis donations that year. In addition, 1.0 million liters were imported, and, at the same time, 1.8 million liters were exported. The quantity available in Germany from a pure arithmetic point of view of 1.4 million liters was almost entirely allocated to basic fractionation, so that a sufficient plasma supply can be assumed. The assessment of the degree of self-sufficiency is made difficult because of the influence of imports and exports; however, the results show no deficit for plasma derivatives. Due to the fact that manufacturing capacities are still lacking in Germany, recombinant factors need to be imported in their entirety. Since 2003, Germany has by far been the leader in Europe with more than 20 liters of fractionation plasma collected per 1,000 inhabitants. Furthermore, regarding the manufacturing figures of red blood cell concentrates, platelet concentrates, and therapeutic single plasma, Germany is in the top third for all these products compared with other European countries. The manufacture of allogeneic stem cell products for hematopoietic reconstitution, obtained by apheresis, has continuously risen to 4,700 in the reporting year. A large portion of this, 1,810 transplants could be exported while only a small number, 179 preparations, had to be imported. The manufacture of autologous stem cell preparations from cord blood also rose drastically compared with 2006, to more than 10,000 in 2007. It must be emphasized that these products were entirely placed into stock; none were transplanted in the reporting year. The interest in the figures collected in compliance with Section 21, Transfusion Act remains high both in Germany and at the international level. Reliable data are available thanks to the evaluations of trends over years, above all on the availability of blood components for transfusion. In addition, the Paul Ehrlich Institute will continue to strive to meet the demands for high-quality information on the supply situation in the future.

The simulated climate of the Last Glacial Maximum and insights into the global carbon cycle.

NASA Astrophysics Data System (ADS)

Buchanan, P. J.; Matear, R.; Lenton, A.; Phipps, S. J.; Chase, Z.; Etheridge, D. M.

2016-12-01

The ocean's ability to store large quantities of carbon, combined with the millennial longevity over which this reservoir is overturned, has implicated the ocean as a key driver of glacial-interglacial climates. However, the combination of processes that cause an accumulation of carbon within the ocean during glacial periods is still under debate. Here we present simulations of the Last Glacial Maximum (LGM) using the CSIRO Mk3L-COAL Earth System Model to test the contribution of key biogeochemical processes to ocean carbon storage. For the coupled LGM simulation, we find that significant cooling (3.2 °C), expanded minimum (Northern Hemisphere: 105 %; Southern Hemisphere: 225 %) and maximum (Northern Hemisphere: 145 %; Southern Hemisphere: 120 %) sea ice cover, and a reorganisation of the overturning circulation caused significant changes in ocean biogeochemical fields. The coupled LGM simulation stores an additional 322 Pg C in the deep ocean relative to the Pre-Industrial (PI) simulation. However, 839 Pg C is lost from the upper ocean via equilibration with a lower atmospheric CO2 concentration, causing a net loss of 517 Pg C relative to the PI simulation. The LGM deep ocean also experiences an oxygenation (>100 mmol O2 m-3) and deepening of the aragonite saturation depth (> 2,000 m deeper) at odds with proxy reconstructions. Hence, these physical changes cannot in isolation produce plausible biogeochemistry nor the required drawdown of atmospheric CO2 of 80-100 ppm at the LGM. With modifications to key biogeochemical processes, which include an increased export of organic matter due to a simulated release from iron limitation, a deepening of remineralisation and decreased inorganic carbon export driven by cooler temperatures, we find that the carbon content in the glacial oceanic reservoir can be increased (326 Pg C) to a level that is sufficient to explain the reduction in atmospheric and terrestrial carbon at the LGM (520 ± 400 Pg C). These modifications also go some way to reconcile simulated export production, aragonite saturation state and oxygen fields with those that have been reconstructed by proxy measurements, thereby implicating past changes in ocean biogeochemistry as an essential driver of the climate system.

Export of fine particulate organic carbon from redwood-dominated catchments

USGS Publications Warehouse

Madej, Mary Ann

2015-01-01

Recently, researchers have recognized the significant role of small mountainous river systems in the transport of carbon from terrestrial environments to the ocean, and the scale of such studies have ranged from channel bed units to continents. In temperate zones, these mountain river systems commonly drain catchments that are largely forested. However, the magnitude of carbon export from rivers draining old-growth redwood forests has not been evaluated to date. Old-growth redwood stands support some of the largest quantities of biomass in the world, up to 350 000 Mg of stem biomass km-2 and soil organic carbon can reach 46 800 Mg km-2. In north coastal California, suspended sediment samples were collected at three gaging stations for two to four years on streams draining old-growth redwood forests. Carbon content, determined through loss-on-ignition tests, was strongly correlated with turbidity, and continuous turbidity records from the gaging stations were used to estimate annual carbon exports of 1 · 6 to 4 · 2 Mg km-2 yr-1. These values, representing 13 to 33% of the suspended sediment load, are some of the highest percentages reported in the global literature. The fraction of organic carbon as part of the suspended sediment load decreased with discharge, but reached an asymptote of 5 to 10% at flows 10 to 20 times the mean annual flows. Although larger rivers in this region exhibit high sediment yields (up to 3600 Mg km-2 yr-1), mainly attributed to high rates of uplift, mass movement, and timber harvest, the small pristine streams in this study have sediment yields of only 8 to 100 Mg km-2 yr-1. Because the current extent of old-growth redwood stands is less than 5% of its pre-European-settlement distribution, the present organic carbon signature in suspended sediment loads in this region is likely different from that in the early 20th century. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Hidden cost of U.S. agricultural exports: particulate matter from ammonia emissions.

PubMed

Paulot, Fabien; Jacob, Daniel J

2014-01-21

We use a model of agricultural sources of ammonia (NH3) coupled to a chemical transport model to estimate the impact of U.S. food export on particulate matter concentrations (PM2.5). We find that food export accounts for 11% of total U.S. NH3 emissions (13% of agricultural emissions) and that it increases the population-weighted exposure of the U.S. population to PM2.5 by 0.36 μg m(-3) on average. Our estimate is sensitive to the proper representation of the impact of NH3 on ammonium nitrate, which reflects the interplay between agricultural (NH3) and combustion emissions (NO, SO2). Eliminating NH3 emissions from food export would achieve greater health benefits than the reduction of the National Ambient Air Quality Standards for PM2.5 from 15 to 12 μg m(-3). Valuation of the increased premature mortality associated with PM2.5 from food export (36 billion US$ (2006) per year) amounts to 50% of the gross food export value. Livestock operations in densely populated areas have particularly large health costs. Decreasing SO2 and NOx emissions will indirectly reduce health impact of food export as an ancillary benefit.

Explosion Hazards Associated with Spills of Large Quantities of Hazardous Materials. Phase I

DTIC Science & Technology

1974-10-01

quantities of hazardous material such as liquified natural gas ( LNG ), liquified petroleum gils (LPG), or ethylene. The principal results are (1) a...associated with spills of large quantities of hazardous material such as liquified natural gas ( LNG ), liquified petroleum gas (LPG), or ethylene. The...liquified natural gas ( LNG ). Unfortunately, as the quantity of material shipped at one time increases, so does the potential hazard associated with

Organic carbon and nitrogen export from a tropical dam-impacted floodplain system

NASA Astrophysics Data System (ADS)

Zurbrügg, R.; Suter, S.; Lehmann, M. F.; Wehrli, B.; Senn, D. B.

2013-01-01

Tropical floodplains play an important role in organic matter transport, storage, and transformation between headwaters and oceans. However, the fluxes and quality of organic carbon (OC) and organic nitrogen (ON) in tropical river-floodplain systems are not well constrained. We explored the quantity and characteristics of dissolved and particulate organic matter (DOM and POM, respectively) in the Kafue River flowing through the Kafue Flats (Zambia), a tropical river-floodplain system in the Zambezi River basin. During the flooding season, > 80% of the Kafue River water passed through the floodplain, mobilizing large quantities of OC and ON, which resulted in a net export of 69-119 kg OC km-2 d-1 and 3.8-4.7 kg ON km-2 d-1, 80% of which was in the dissolved form. The elemental C : N ratio of ~ 20, the comparatively high δ13C values of -25‰ to -21‰, and its spectroscopic properties (excitation-emission matrices) showed that DOM in the river was mainly of terrestrial origin. Despite a threefold increase in OC loads due to inputs from the floodplain, the characteristics of the riverine DOM remained relatively constant along the sampled 410-km river reach. This suggests that floodplain DOM displayed properties similar to those of DOM leaving the upstream reservoir and implied that the DOM produced in the reservoir was relatively short-lived. In contrast, the particulate fraction was 13C-depleted (-29‰) and had a C : N ratio of ~ 8, which indicated that POM originated from phytoplankton production in the reservoir and in the floodplain, rather than from plant debris or resuspended sediments. While the upstream dam had little effect on the DOM pool, terrestrial particles were retained, and POM from algal and microbial sources was released to the river. A nitrogen mass balance over the 2200 km2 flooded area revealed an annual deficit of 15 500-22 100 t N in the Kafue Flats. The N isotope budget suggests that these N losses are balanced by intense N-fixation. Our study shows that the Kafue Flats are a significant local source of OC and ON to downstream ecosystems and illustrates how the composition of riverine OM can be altered by dams and floodplains in tropical catchments.

Land Use and Climate Alter Carbon Dynamics in Watersheds of Chesapeake Bay

NASA Astrophysics Data System (ADS)

Kaushal, S.; Duan, S.; Grese, M.; Pennino, M. J.; Belt, K. T.; Findlay, S.; Groffman, P. M.; Mayer, P. M.; Murthy, S.; Blomquist, J.

2011-12-01

There have been long-term changes in the quantity of organic carbon in streams and rivers globally. Shifts in the quality of organic carbon due to environmental changes may also impact downstream ecosystem metabolism and fate and transport of contaminants. We investigated long-term impacts of land use and hydrologic variability on organic carbon transport in watersheds of the Baltimore Long-Term Ecological Research (LTER) site and large rivers of the Chesapeake Bay. In small and medium-sized watersheds of the Baltimore LTER site, urban land use increased organic carbon concentrations in streams several-fold compared to forest and agricultural watersheds. Enzymatic activities of stream microbes were significantly altered across watershed land use during a record wet year. During the wet year, short-term bioassays showed that bioavailable dissolved organic carbon varied seasonally, but comprised a substantial proportion of the dissolved organic carbon pool. Similarly, measurements of biochemical oxygen demand across hydrologic variability suggest that reactive organic carbon export from small and medium-sized urban watersheds during storms can be substantial. At a larger regional scale, major tributaries such as the Potomac, Susquehanna, Patuxent, and Choptank rivers also showed similar variability as smaller watersheds in quantity and quality of organic carbon based on land use and climate. There were distinct isotopic values of d13C of particulate organic matter and fluorescence excitation emission matrices for rivers influenced by different land uses. Stable isotopic values of d13C of particulate organic matter and fluorescence excitation emission matrices showed marked seasonal changes in organic matter quality during spring floods in the Potomac River at Washington D.C. Across watershed size, there appeared to be differences in seasonal cycles of organic carbon quality and this may have been based on the degree of hydrologic connectivity between watersheds and streams and rivers. Overall, our results suggest that land use and climate can alter quantity and quality of carbon delivered from coastal watersheds and this may have impacts on downstream estuarine ecosystem processes.

Simulation of runoff and nutrient export from a typical small watershed in China using the Hydrological Simulation Program-Fortran.

PubMed

Li, Zhaofu; Liu, Hongyu; Luo, Chuan; Li, Yan; Li, Hengpeng; Pan, Jianjun; Jiang, Xiaosan; Zhou, Quansuo; Xiong, Zhengqin

2015-05-01

The Hydrological Simulation Program-Fortran (HSPF), which is a hydrological and water-quality computer model that was developed by the United States Environmental Protection Agency, was employed to simulate runoff and nutrient export from a typical small watershed in a hilly eastern monsoon region of China. First, a parameter sensitivity analysis was performed to assess how changes in the model parameters affect runoff and nutrient export. Next, the model was calibrated and validated using measured runoff and nutrient concentration data. The Nash-Sutcliffe efficiency (E NS ) values of the yearly runoff were 0.87 and 0.69 for the calibration and validation periods, respectively. For storms runoff events, the E NS values were 0.93 for the calibration period and 0.47 for the validation period. Antecedent precipitation and soil moisture conditions can affect the simulation accuracy of storm event flow. The E NS values for the total nitrogen (TN) export were 0.58 for the calibration period and 0.51 for the validation period. In addition, the correlation coefficients between the observed and simulated TN concentrations were 0.84 for the calibration period and 0.74 for the validation period. For phosphorus export, the E NS values were 0.89 for the calibration period and 0.88 for the validation period. In addition, the correlation coefficients between the observed and simulated orthophosphate concentrations were 0.96 and 0.94 for the calibration and validation periods, respectively. The nutrient simulation results are generally satisfactory even though the parameter-lumped HSPF model cannot represent the effects of the spatial pattern of land cover on nutrient export. The model parameters obtained in this study could serve as reference values for applying the model to similar regions. In addition, HSPF can properly describe the characteristics of water quantity and quality processes in this area. After adjustment, calibration, and validation of the parameters, the HSPF model is suitable for hydrological and water-quality simulations in watershed planning and management and for designing best management practices.

77 FR 33181 - Large Residential Washers From the Republic of Korea: Preliminary Affirmative Countervailing Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-05

... does not include a rate for either the ``Korea Trade Insurance Corporation (K-SURE)-- Short-Term Export.... C. Benchmark Interest Rate for Short-Term Loans Section 771(5)(E)(ii) of the Act states that the... Development Bank (KDB)/IBK Short-Term Discounted Loans for Export Receivables'' program, an analysis of any...

Exchange of nitrogen and phosphorus between a shallow lagoon and coastal waters

USGS Publications Warehouse

Hayn, Melanie; Howarth, Robert W.; Ganju, Neil K.; Berg, Peter; Foreman, Kenneth H.; Giblin, Anne E.; McGlathery, Karen

2014-01-01

West Falmouth Harbor, a shallow lagoon on Cape Cod, has experienced a threefold increase in nitrogen load since the mid- to late 1990s due to input from a groundwater plume contaminated by a municipal wastewater treatment plant. We measured the exchange of nitrogen and phosphorus between the harbor and the coastal waters of Buzzards Bay over several years when the harbor was experiencing this elevated nitrogen load. During summer months, the harbor not only retained the entire watershed nitrogen load but also had a net import of nitrogen from Buzzards Bay. During the spring and fall, the harbor had a net export of nitrogen to Buzzards Bay. We did not measure the export in winter, but assuming the winter net export was less than 112 % of the load, the harbor exported less than half of the watershed nitrogen load on an annual basis. For phosphorus, the harbor had a net import from coastal waters in the spring and summer months and a net export in the fall. Despite the large increase in nitrogen load to the harbor, the summertime import of phosphorus from Buzzards Bay was sufficient to maintain nitrogen limitation of primary productivity during the summer. Our findings illustrate that shallow systems dominated by benthic producers have the potential to retain large terrestrial nitrogen loads when there is sufficient supply of phosphorus from exchange with coastal waters.

Changes in dissolved organic matter quality in a peatland and forest headwater stream as a function of seasonality and hydrologic conditions

NASA Astrophysics Data System (ADS)

Broder, Tanja; Knorr, Klaus-Holger; Biester, Harald

2017-04-01

Peatlands and peaty riparian zones are major sources of dissolved organic matter (DOM), but are poorly understood in terms of export dynamics and controls thereof. Thereby quality of DOM affects function and behavior of DOM in aquatic ecosystems, but DOM quality can also help to track DOM sources and their export dynamics under specific hydrologic preconditions. The objective of this study was to elucidate controls on temporal variability in DOM concentration and quality in stream water draining a bog and a forested peaty riparian zone, particularly considering drought and storm flow events. DOM quality was monitored using spectrofluorometric indices for aromaticity (SUVA254), apparent molecular size (SR) and precursor organic material (FI), as well as PARAFAC modeling of excitation emission matrices (EEMs). Indices for DOM quality exhibited major changes due to different hydrologic conditions, but patterns were also dependent on season. Stream water at the forested site with mineral, peaty soils generally exhibited higher variability in DOM concentrations and quality compared to the outflow of an ombrotrophic bog, where DOM was less susceptible to changes in hydrologic conditions. During snowmelt and spring events, near-surface protein-like DOM pools were exported. A microbial DOM fraction originating from groundwater and deep peat layers was increasing during drought, while a strongly microbially altered DOM fraction was also exported by discharge events with dry preconditions at the forested site. This might be due to accelerated microbial activity in the peaty riparian zone of the forested site under these preconditions. Our study demonstrated that DOM export dynamics are not only a passive mixing of different hydrological sources, but monitoring studies have to consider that DOM quality depends on hydrologic preconditions and season. Moreover, the forested peaty riparian zone generated the most variability in headwater DOM quantity and quality, as could be tracked by the used spectrofluorometric indices.

Regulation of mRNA Trafficking by Nuclear Pore Complexes

PubMed Central

Bonnet, Amandine; Palancade, Benoit

2014-01-01

Over the last two decades, multiple studies have explored the mechanisms governing mRNA export out of the nucleus, a crucial step in eukaryotic gene expression. During transcription and processing, mRNAs are assembled into messenger ribonucleoparticles (mRNPs). mRNPs are then exported through nuclear pore complexes (NPCs), which are large multiprotein assemblies made of several copies of a limited number of nucleoporins. A considerable effort has been put into the dissection of mRNA export through NPCs at both cellular and molecular levels, revealing the conserved contributions of a subset of nucleoporins in this process, from yeast to vertebrates. Several reports have also demonstrated the ability of NPCs to sort out properly-processed mRNPs for entry into the nuclear export pathway. Importantly, changes in mRNA export have been associated with post-translational modifications of nucleoporins or changes in NPC composition, depending on cell cycle progression, development or exposure to stress. How NPC modifications also impact on cellular mRNA export in disease situations, notably upon viral infection, is discussed. PMID:25184662

Effects of lakes and reservoirs on annual river nitrogen, phosphorus, and sediment export in agricultural and forested landscapes

USGS Publications Warehouse

Powers, Stephen M.; Robertson, Dale M.; Stanley, Emily H.

2014-01-01

Recently, effects of lakes and reservoirs on river nutrient export have been incorporated into landscape biogeochemical models. Because annual export varies with precipitation, there is a need to examine the biogeochemical role of lakes and reservoirs over time frames that incorporate interannual variability in precipitation. We examined long-term (~20 years) time series of river export (annual mass yield, Y, and flow-weighted mean annual concentration, C) for total nitrogen (TN), total phosphorus (TP), and total suspended sediment (TSS) from 54 catchments in Wisconsin, USA. Catchments were classified as small agricultural, large agricultural, and forested by use of a cluster analysis, and these varied in lentic coverage (percentage of catchment lake or reservoir water that was connected to river network). Mean annual export and interannual variability (CV) of export (for both Y and C) were higher in agricultural catchments relative to forested catchments for TP, TN, and TSS. In both agricultural and forested settings, mean and maximum annual TN yields were lower in the presence of lakes and reservoirs, suggesting lentic denitrification or N burial. There was also evidence of long-term lentic TP and TSS retention, especially when viewed in terms of maximum annual yield, suggesting sedimentation during high loading years. Lentic catchments had lower interannual variability in export. For TP and TSS, interannual variability in mass yield was often >50% higher than interannual variability in water yield, whereas TN variability more closely followed water (discharge) variability. Our results indicate that long-term mass export through rivers depends on interacting terrestrial, aquatic, and meteorological factors in which the presence of lakes and reservoirs can reduce the magnitude of export, stabilize interannual variability in export, as well as introduce export time lags.

Uncoupling of the hnRNP Npl3p from mRNAs during the stress-induced block in mRNA export.

PubMed

Krebber, H; Taura, T; Lee, M S; Silver, P A

1999-08-01

Npl3p, the major mRNA-binding protein of the yeast Saccharomyces cerevisiae shuttles between the nucleus and the cytoplasm. A single amino acid change in the carboxyl terminus of Npl3p (E409 --> K) renders the mutant protein largely cytoplasmic because of a delay in its import into the nucleus. This import defect can be reversed by increasing the intracellular concentration of Mtr10p, the nuclear import receptor for Npl3p. Conversely, using this mutant, we show that Npl3p and mRNA export out of the nucleus is significantly slowed in cells bearing mutations in XPO1/CRM1, which encodes the export receptor for NES-containing proteins and in RAT7, which encodes an essential nucleoporin. Interestingly, following induction of stress by heat shock, high salt, or ethanol, conditions under which most mRNA export is blocked, Npl3p is still exported from the nucleus. The stress-induced export of Npl3p is independent of both the activity of Xpo1p and the continued selective export of heat-shock mRNAs that occurs following stress. UV-cross-linking experiments show that Npl3p is bound to mRNA under normal conditions, but is no longer RNA associated in stressed cells. Taken together, we suggest that the uncoupling of Npl3p and possibly other mRNA-binding proteins from mRNAs in the nucleus provides a general switch that regulates mRNA export. By this model, under normal conditions Npl3p is a major component of an export-competent RNP complex. However, under conditions of stress, Npl3p no longer associates with the export complex, rendering it export incompetent and thus nuclear.

Contrasting vulnerability of drained tropical and high-latitude peatlands to fluvial loss of stored carbon

NASA Astrophysics Data System (ADS)

Evans, Chris D.; Page, Susan E.; Jones, Tim; Moore, Sam; Gauci, Vincent; Laiho, Raija; Hruška, Jakub; Allott, Tim E. H.; Billett, Michael F.; Tipping, Ed; Freeman, Chris; Garnett, Mark H.

2014-11-01

Carbon sequestration and storage in peatlands rely on consistently high water tables. Anthropogenic pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of peat-forming vegetation and exposure of previously anaerobic peat to aerobic decomposition. This can shift peatlands from net CO2 sinks to large CO2 sources, releasing carbon held for millennia. Peatlands also export significant quantities of carbon via fluvial pathways, mainly as dissolved organic carbon (DOC). We analyzed radiocarbon (14C) levels of DOC in drainage water from multiple peatlands in Europe and Southeast Asia, to infer differences in the age of carbon lost from intact and drained systems. In most cases, drainage led to increased release of older carbon from the peat profile but with marked differences related to peat type. Very low DOC-14C levels in runoff from drained tropical peatlands indicate loss of very old (centuries to millennia) stored peat carbon. High-latitude peatlands appear more resilient to drainage; 14C measurements from UK blanket bogs suggest that exported DOC remains young (<50 years) despite drainage. Boreal and temperate fens and raised bogs in Finland and the Czech Republic showed intermediate sensitivity. We attribute observed differences to physical and climatic differences between peatlands, in particular, hydraulic conductivity and temperature, as well as the extent of disturbance associated with drainage, notably land use changes in the tropics. Data from the UK Peak District, an area where air pollution and intensive land management have triggered Sphagnum loss and peat erosion, suggest that additional anthropogenic pressures may trigger fluvial loss of much older (>500 year) carbon in high-latitude systems. Rewetting at least partially offsets drainage effects on DOC age.

Pesticide application practices, pest knowledge, and cost-benefits of plantain production in the Bribri-Cabecar Indigenous Territories, Costa Rica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polidoro, Beth A.; Department of Agroforestry, Tropical Agricultural Research and Higher Education Center; Dahlquist, Ruth M.

The use of pesticides in the cultivation of cash crops such as banana and plantain is increasing, in Costa Rica and worldwide. Agrochemical use and occupational and environmental exposures in export banana production have been documented in some parts of Central America. However, the extent of agrochemical use, agricultural pest knowledge, and economic components in plantain production are largely unknown in Costa Rica, especially in remote, high-poverty areas such as the Bribri-Cabecar Indigenous Territories. Our objective was to integrate a rapid rural appraisal of indigenous farmer pesticide application practices and pest knowledge with a cost-benefit analysis of plantain production inmore » the Bribri-Cabecar Indigenous Territories, for the development of better agricultural management practices and improved regulatory infrastructure. Interviews conducted with 75 households in 5 indigenous communities showed that over 60% of participants grew plantain with agrochemicals. Of these plantain farmers, over 97% used the insecticide chlorpyrifos, and 84% applied nematicides, 64% herbicides, and 22% fungicides, with only 31% of participants reporting the use of some type of protective clothing during application. The banana weevil (Cosmopolites sordidus Germar) was ranked as the most important agricultural pest by 85% of participants, yet only 28% could associate the adult and larval form. A cost-benefit analysis conducted with a separate group of 26 plantain farmers identified several national markets and one export market for plantain production in the Indigenous Territories. Yearly income averaged US$6200/ha and yearly expenses averaged US$1872/ha, with an average cost-benefit ratio of 3.67 for plantain farmers. Farmers applied an average of 9.7 kg a.i./ha/yr of pesticide products and 375 kg/ha/yr of fertilizer, but those who sold their fruit to the national markets applied more nematicides, herbicides, and fertilizers than those who sold primarily to export markets, suggesting a lack of appropriate application knowledge. Results indicate that the quantity of agrochemicals applied in plantain cultivation is less than that applied in export banana, but the absence of appropriate agrochemical application practices in plantain cultivation may pose serious risks to human and environmental health. Culturally appropriate farmer education and certification programs are needed as well as the development of safe-handling practices, regulatory infrastructure, and adequate agrochemical storage, transport, and waste disposal facilities. Long-term solutions however, are dependent on the development of policies and infrastructure that support non-chemical pest management, alternatives to pesticides, and the identification of organic plantain markets.« less

Pesticide application practices, pest knowledge, and cost-benefits of plantain production in the Bribri-Cabécar Indigenous Territories, Costa Rica.

PubMed

Polidoro, Beth A; Dahlquist, Ruth M; Castillo, Luisa E; Morra, Matthew J; Somarriba, Eduardo; Bosque-Pérez, Nilsa A

2008-09-01

The use of pesticides in the cultivation of cash crops such as banana and plantain is increasing, in Costa Rica and worldwide. Agrochemical use and occupational and environmental exposures in export banana production have been documented in some parts of Central America. However, the extent of agrochemical use, agricultural pest knowledge, and economic components in plantain production are largely unknown in Costa Rica, especially in remote, high-poverty areas such as the Bribri-Cabécar Indigenous Territories. Our objective was to integrate a rapid rural appraisal of indigenous farmer pesticide application practices and pest knowledge with a cost-benefit analysis of plantain production in the Bribri-Cabécar Indigenous Territories, for the development of better agricultural management practices and improved regulatory infrastructure. Interviews conducted with 75 households in 5 indigenous communities showed that over 60% of participants grew plantain with agrochemicals. Of these plantain farmers, over 97% used the insecticide chlorpyrifos, and 84% applied nematicides, 64% herbicides, and 22% fungicides, with only 31% of participants reporting the use of some type of protective clothing during application. The banana weevil (Cosmopolites sordidus Germar) was ranked as the most important agricultural pest by 85% of participants, yet only 28% could associate the adult and larval form. A cost-benefit analysis conducted with a separate group of 26 plantain farmers identified several national markets and one export market for plantain production in the Indigenous Territories. Yearly income averaged US$6200/ha and yearly expenses averaged US$1872/ha, with an average cost-benefit ratio of 3.67 for plantain farmers. Farmers applied an average of 9.7 kg a.i./ha/yr of pesticide products and 375 kg/ha/yr of fertilizer, but those who sold their fruit to the national markets applied more nematicides, herbicides, and fertilizers than those who sold primarily to export markets, suggesting a lack of appropriate application knowledge. Results indicate that the quantity of agrochemicals applied in plantain cultivation is less than that applied in export banana, but the absence of appropriate agrochemical application practices in plantain cultivation may pose serious risks to human and environmental health. Culturally appropriate farmer education and certification programs are needed as well as the development of safe-handling practices, regulatory infrastructure, and adequate agrochemical storage, transport, and waste disposal facilities. Long-term solutions however, are dependent on the development of policies and infrastructure that support non-chemical pest management, alternatives to pesticides, and the identification of organic plantain markets.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, C

Purpose: To implement a novel, automatic, institutional customizable DVH quantities evaluation and PDF report tool on Philips Pinnacle treatment planning system (TPS) Methods: An add-on program (P3DVHStats) is developed by us to enable automatic DVH quantities evaluation (including both volume and dose based quantities, such as V98, V100, D2), and automatic PDF format report generation, for EMR convenience. The implementation is based on a combination of Philips Pinnacle scripting tool and Java language pre-installed on each Pinnacle Sun Solaris workstation. A single Pinnacle script provide user a convenient access to the program when needed. The activated script will first exportmore » DVH data for user selected ROIs from current Pinnacle plan trial; a Java program then provides a simple GUI interface, utilizes the data to compute any user requested DVH quantities, compare with preset institutional DVH planning goals; if accepted by users, the program will also generate a PDF report of the results and export it from Pinnacle to EMR import folder via FTP. Results: The program was tested thoroughly and has been released for clinical use at our institution (Pinnacle Enterprise server with both thin clients and P3PC access), for all dosimetry and physics staff, with excellent feedback. It used to take a few minutes to use MS-Excel worksheet to calculate these DVH quantities for IMRT/VMAT plans, and manually save them as PDF report; with the new program, it literally takes a few mouse clicks in less than 30 seconds to complete the same tasks. Conclusion: A Pinnacle scripting and Java language based program is successfully implemented, customized to our institutional needs. It is shown to dramatically reduce time and effort needed for DVH quantities computing and EMR reporting.« less

High Quantities of Microplastic in Arctic Deep-Sea Sediments from the HAUSGARTEN Observatory.

PubMed

Bergmann, Melanie; Wirzberger, Vanessa; Krumpen, Thomas; Lorenz, Claudia; Primpke, Sebastian; Tekman, Mine B; Gerdts, Gunnar

2017-10-03

Although mounting evidence suggests the ubiquity of microplastic in aquatic ecosystems worldwide, our knowledge of its distribution in remote environments such as Polar Regions and the deep sea is scarce. Here, we analyzed nine sediment samples taken at the HAUSGARTEN observatory in the Arctic at 2340-5570 m depth. Density separation by MicroPlastic Sediment Separator and treatment with Fenton's reagent enabled analysis via Attenuated Total Reflection FTIR and μFTIR spectroscopy. Our analyses indicate the wide spread of high numbers of microplastics (42-6595 microplastics kg -1 ). The northernmost stations harbored the highest quantities, indicating sea ice as a possible transport vehicle. A positive correlation between microplastic abundance and chlorophyll a content suggests vertical export via incorporation in sinking (ice-) algal aggregates. Overall, 18 different polymers were detected. Chlorinated polyethylene accounted for the largest proportion (38%), followed by polyamide (22%) and polypropylene (16%). Almost 80% of the microplastics were ≤25 μm. The microplastic quantities are among the highest recorded from benthic sediments. This corroborates the deep sea as a major sink for microplastics and the presence of accumulation areas in this remote part of the world, fed by plastics transported to the North via the Thermohaline Circulation.

Water Quality and Quantity Implications of Biofuel Intercropping at a Regional Scale (Invited)

NASA Astrophysics Data System (ADS)

Christopher, S. F.; Schoenholtz, S. H.; Nettles, J.

2010-12-01

Because of a strong national interest in greater energy independence and concern for the role of fossil fuels in global climate change, the importance of biofuels as an alternative renewable energy source has developed rapidly. The U.S. government has mandated production of 36 billion gallons of renewable fuels by 2022, which compromises 15 % of U.S. liquid transportation fuels. Large-scale production of corn-based ethanol often requires irrigation and is associated with erosion, excess sediment export, and leaching of nitrogen and phosphorus. Production of cellulosic biomass offers a promising alternative to corn-based systems. Although cultivation of switchgrass using standard agricultural practices is one option being considered for production of cellulosic biomass, intercropping cellulosic biofuel crops within managed forests could provide feedstock without primary land use change or the water quality impacts associated with annual crops. Catchlight Energy LLC is examining the feasibility and sustainability of intercropping switchgrass in loblolly pine plantations in the southeastern US. While ongoing research is determining efficient operational techniques, information needed to evaluate the effects of these practices on water resources, such as field-scale evapotranspiration rates, nutrient cycling, and soil erosion rates are being examined in a large watershed study. Three sets of four to five sub-watersheds are fully instrumented and currently collecting calibration data, with forest-based biofuel treatments to be installed in 2011 and 2012. These watershed studies will give us detailed information to understand processes and guide management decisions. However, environmental implications of these systems need to be examined at a regional scale. We used the Soil Water Assessment Tool (SWAT), a physically-based hydrologic model, to examine various scenarios ranging from switchgrass intercropping a small percentage of managed pine forest land to conversion of all managed forested land to switchgrass. The current results are based on early indicators from operational trials, but will be refined as the watershed studies progress. Our results will be essential to public policy makers as they influence and plan for large-scale production of cellulosic biofuels while sustaining water quality and quantity.

The Single European Act for 1992 and U.S. Television Programming.

ERIC Educational Resources Information Center

Noor Al-Deen, Hana S.

Global exports of television programs have been dominated by U.S. companies. Most of their exports are sold to Western European countries. Such a large influx of imports brings with it cultural values that can subvert the indigenous culture and may lead to cultural hegemony. To reach some balance with the United States in the cultural/media…

Influence of diatom diversity on the ocean biological carbon pump

NASA Astrophysics Data System (ADS)

Tréguer, Paul; Bowler, Chris; Moriceau, Brivaela; Dutkiewicz, Stephanie; Gehlen, Marion; Aumont, Olivier; Bittner, Lucie; Dugdale, Richard; Finkel, Zoe; Iudicone, Daniele; Jahn, Oliver; Guidi, Lionel; Lasbleiz, Marine; Leblanc, Karine; Levy, Marina; Pondaven, Philippe

2018-01-01

Diatoms sustain the marine food web and contribute to the export of carbon from the surface ocean to depth. They account for about 40% of marine primary productivity and particulate carbon exported to depth as part of the biological pump. Diatoms have long been known to be abundant in turbulent, nutrient-rich waters, but observations and simulations indicate that they are dominant also in meso- and submesoscale structures such as fronts and filaments, and in the deep chlorophyll maximum. Diatoms vary widely in size, morphology and elemental composition, all of which control the quality, quantity and sinking speed of biogenic matter to depth. In particular, their silica shells provide ballast to marine snow and faecal pellets, and can help transport carbon to both the mesopelagic layer and deep ocean. Herein we show that the extent to which diatoms contribute to the export of carbon varies by diatom type, with carbon transfer modulated by the Si/C ratio of diatom cells, the thickness of the shells and their life strategies; for instance, the tendency to form aggregates or resting spores. Model simulations project a decline in the contribution of diatoms to primary production everywhere outside of the Southern Ocean. We argue that we need to understand changes in diatom diversity, life cycle and plankton interactions in a warmer and more acidic ocean in much more detail to fully assess any changes in their contribution to the biological pump.

Comparison of sediment and nutrient export and runoff characteristics from watersheds with centralized versus distributed stormwater management

USGS Publications Warehouse

Hopkins, Kristina G.; Loperfido, J.V.; Craig, Laura S.; Noe, Gregory; Hogan, Dianna

2017-01-01

Stormwater control measures (SCMs) are used to retain stormwater and pollutants. SCMs have traditionally been installed in a centralized manner using detention to mitigate peak flows. Recently, distributed SCM networks that treat runoff near the source have been increasingly utilized. The aim of this study was to evaluate differences among watersheds that vary in SCM arrangement by assessing differences in baseflow nutrient (NOx-N and PO4−) concentrations and fluxes, stormflow export of suspended sediments and particulate phosphorus (PP), and runoff characteristics. A paired watershed approach was used to compare export between 2004 and 2016 from one forested watershed (For-MD), one suburban watershed with centralized SCMs (Cent-MD), and one suburban watershed with distributed SCMs (Dist-MD). Results indicated baseflow nitrate (NOx-N) concentrations typically exceeded 1 mg-N/L in all watersheds and were highest in Dist-MD. Over the last 10 years in Dist-MD, nitrate concentrations in both stream baseflow and in a groundwater well declined as land use shifted from agriculture to suburban. Baseflow nitrate export temporarily increased during the construction phase of SCM development in Dist-MD. This temporary pulse of nitrate may be attributed to the conversion of sediment control facilities to SCMs and increased subsurface flushing as infiltration SCMs came on line. During storm flow, Dist-MD tended to have less runoff and lower maximum specific discharge than Cent-MD for small events (<1.3 cm), but runoff responses became increasingly similar to Cent-MD with increasing precipitation (>1.3 cm). Mass export estimated during paired storm events indicated Dist-MD exported 30% less sediment and 31% more PP than Cent-MD. For large precipitation events, export of sediment and PP was similar among all three watersheds. Results suggest that distributed SCMs can reduce runoff and sediment loads during small rain events compared to centralized SCMs, but these differences become less evident for large events when peak discharge likely leads to substantial bank erosion.

Particulate organic carbon export across the Antarctic Circumpolar Current at 10°E: Differences between north and south of the Antarctic Polar Front

NASA Astrophysics Data System (ADS)

Puigcorbé, Viena; Roca-Martí, Montserrat; Masqué, Pere; Benitez-Nelson, Claudia R.; Rutgers v. d. Loeff, Michiel; Laglera, Luis M.; Bracher, Astrid; Cheah, Wee; Strass, Volker H.; Hoppema, Mario; Santos-Echeandía, Juan; Hunt, Brian P. V.; Pakhomov, Evgeny A.; Klaas, Christine

2017-04-01

The vertical distribution of 234Th was measured along the 10°E meridian between 44°S and 53°S in the Antarctic Circumpolar Current (ACC) during the austral summer of 2012. The overarching goal of this work was to estimate particulate organic carbon (POC) export across three fronts: the Sub-Antarctic Front (SAF), the Antarctic Polar Front (APF) and the Southern Polar Front (SPF). Steady state export fluxes of 234Th in the upper 100 m ranged from 1600 to 2600 dpm m-2 d-1, decreasing with increasing latitude. Using large particle (>53 μm) C/234Th ratios, the 234Th-derived POC fluxes at 100 m ranged from 25 to 41 mmol C m-2 d-1. Observed C/234Th ratios decreased with increasing depth north of the APF while south of the APF, ratios remained similar or even increased with depth. These changes in C/234Th ratios are likely due to differences in the food web. Indeed, satellite images, together with macronutrients and dissolved iron concentrations suggest two different planktonic community structures north and south of the APF. Our results indicate that higher ratios of POC flux at 100 m to primary production occurred in nanophytoplankton dominated surface waters, where primary production rates were lower. Satellite images prior to the expedition suggest that the higher export efficiencies obtained in the northern half of the transect may be the result of the decoupling between production and export (Buesseler 1998). Transfer efficiencies to 400 m, i.e. the fraction of exported POC that reached 400 m, were found to be higher south of the APF, where diatoms were dominant and salps largely abundant. This suggests different remineralization pathways of sinking particles, influencing the transfer efficiency of exported POC to depth.

Fluid flow enhances the effectiveness of toxin export by aquatic microorganisms: A first-passage perspective on microvilli and the concentration boundary layer

NASA Astrophysics Data System (ADS)

Licata, Nicholas A.; Clark, Aaron

2015-01-01

A central challenge for organisms during development is determining a means to efficiently export toxic molecules from inside the developing embryo. For aquatic microorganisms, the strategies employed should be robust with respect to the variable ocean environment and limit the chances that exported toxins are reabsorbed. As a result, the problem of toxin export is closely related to the physics of mass transport in a fluid. In this paper, we consider a model first-passage problem for the uptake of exported toxins by a spherical embryo. By considering how macroscale fluid turbulence manifests itself on the microscale of the embryo, we determine that fluid flow enhances the effectiveness of toxin export as compared to the case of diffusion-limited transport. In the regime of a large Péclet number, a perturbative solution of the advection-diffusion equation reveals that a concentration boundary layer forms at the surface of the embryo. The model results suggest a functional role for cell surface roughness in the export process, with the thickness of the concentration boundary layer setting the length scale for cell membrane protrusions known as microvilli. We highlight connections between the model results and experiments on the development of sea urchin embryos.

Fish Rejections in the Marine Aquarium Trade: An Initial Case Study Raises Concern for Village-Based Fisheries

PubMed Central

Militz, Thane A.; Kinch, Jeff; Foale, Simon; Southgate, Paul C.

2016-01-01

A major difficulty in managing wildlife trade is the reliance on trade data (rather than capture data) to monitor exploitation of wild populations. Collected organisms that die or are rejected before a point of sale often go unreported. For the global marine aquarium trade, identifying the loss of collected fish from rejection, prior to export, is a first step in assessing true collection levels. This study takes a detailed look at fish rejections by buyers before export using the Papua New Guinea marine aquarium fishery as a case study. Utilizing collection invoices detailing the species and quantity of fish (Actinopteri and Elasmobranchii) accepted or rejected by the exporting company it was determined that, over a six month period, 24.2% of the total fish catch reported (n = 13,886) was rejected. Of the ten most collected fish families, rejection frequency was highest for the Apogonidae (54.2%), Chaetodontidae (26.3%), and Acanthuridae (18.2%) and lowest for Labridae (6.6%) and Hemiscylliidae (0.7%). The most frequently cited reasons for rejection were fin damage (45.6% of cases), undersized fish (21.8%), and fish deemed too thin (11.1%). Despite fishers receiving feedback on invoices explaining rejections, there was no improvement in rejection frequencies over time (r = -0.33, P = 0.15) with weekly rejection frequencies being highly inconsistent (range: 2.8% to 79.4%; s = 16.3%). These findings suggest that export/import statistics can greatly underestimate collection for the marine aquarium trade as additional factors such as fisher discards, escapees, post-collection mortalities, and unregulated domestic trade would further contribute to this disparity. PMID:26963259

Freshwater and its role in the Arctic Marine System: Sources, disposition, storage, export, and physical and biogeochemical consequences in the Arctic and global oceans

NASA Astrophysics Data System (ADS)

Carmack, E. C.; Yamamoto-Kawai, M.; Haine, T. W. N.; Bacon, S.; Bluhm, B. A.; Lique, C.; Melling, H.; Polyakov, I. V.; Straneo, F.; Timmermans, M.-L.; Williams, W. J.

2016-03-01

The Arctic Ocean is a fundamental node in the global hydrological cycle and the ocean's thermohaline circulation. We here assess the system's key functions and processes: (1) the delivery of fresh and low-salinity waters to the Arctic Ocean by river inflow, net precipitation, distillation during the freeze/thaw cycle, and Pacific Ocean inflows; (2) the disposition (e.g., sources, pathways, and storage) of freshwater components within the Arctic Ocean; and (3) the release and export of freshwater components into the bordering convective domains of the North Atlantic. We then examine physical, chemical, or biological processes which are influenced or constrained by the local quantities and geochemical qualities of freshwater; these include stratification and vertical mixing, ocean heat flux, nutrient supply, primary production, ocean acidification, and biogeochemical cycling. Internal to the Arctic the joint effects of sea ice decline and hydrological cycle intensification have strengthened coupling between the ocean and the atmosphere (e.g., wind and ice drift stresses, solar radiation, and heat and moisture exchange), the bordering drainage basins (e.g., river discharge, sediment transport, and erosion), and terrestrial ecosystems (e.g., Arctic greening, dissolved and particulate carbon loading, and altered phenology of biotic components). External to the Arctic freshwater export acts as both a constraint to and a necessary ingredient for deep convection in the bordering subarctic gyres and thus affects the global thermohaline circulation. Geochemical fingerprints attained within the Arctic Ocean are likewise exported into the neighboring subarctic systems and beyond. Finally, we discuss observed and modeled functions and changes in this system on seasonal, annual, and decadal time scales and discuss mechanisms that link the marine system to atmospheric, terrestrial, and cryospheric systems.

Fish Rejections in the Marine Aquarium Trade: An Initial Case Study Raises Concern for Village-Based Fisheries.

PubMed

Militz, Thane A; Kinch, Jeff; Foale, Simon; Southgate, Paul C

2016-01-01

A major difficulty in managing wildlife trade is the reliance on trade data (rather than capture data) to monitor exploitation of wild populations. Collected organisms that die or are rejected before a point of sale often go unreported. For the global marine aquarium trade, identifying the loss of collected fish from rejection, prior to export, is a first step in assessing true collection levels. This study takes a detailed look at fish rejections by buyers before export using the Papua New Guinea marine aquarium fishery as a case study. Utilizing collection invoices detailing the species and quantity of fish (Actinopteri and Elasmobranchii) accepted or rejected by the exporting company it was determined that, over a six month period, 24.2% of the total fish catch reported (n = 13,886) was rejected. Of the ten most collected fish families, rejection frequency was highest for the Apogonidae (54.2%), Chaetodontidae (26.3%), and Acanthuridae (18.2%) and lowest for Labridae (6.6%) and Hemiscylliidae (0.7%). The most frequently cited reasons for rejection were fin damage (45.6% of cases), undersized fish (21.8%), and fish deemed too thin (11.1%). Despite fishers receiving feedback on invoices explaining rejections, there was no improvement in rejection frequencies over time (r = -0.33, P = 0.15) with weekly rejection frequencies being highly inconsistent (range: 2.8% to 79.4%; s = 16.3%). These findings suggest that export/import statistics can greatly underestimate collection for the marine aquarium trade as additional factors such as fisher discards, escapees, post-collection mortalities, and unregulated domestic trade would further contribute to this disparity.

Nuclear export of ubiquitinated proteins via the UBIN-POST system

PubMed Central

Sugihara, Munechika; Morito, Daisuke; Iemura, Shun-ichiro; Natsume, Tohru; Nagata, Kazuhiro

2018-01-01

Although mechanisms for protein homeostasis in the cytosol have been studied extensively, those in the nucleus remain largely unknown. Here, we identified that a protein complex mediates export of polyubiquitinated proteins from the nucleus to the cytosol. UBIN, a ubiquitin-associated (UBA) domain-containing protein, shuttled between the nucleus and the cytosol in a CRM1-dependent manner, despite the lack of intrinsic nuclear export signal (NES). Instead, the UBIN binding protein polyubiquitinated substrate transporter (POST) harboring an NES shuttled UBIN through nuclear pores. UBIN bound to polyubiquitin chain through its UBA domain, and the UBIN-POST complex exported them from the nucleus to the cytosol. Ubiquitinated proteins accumulated in the cytosol in response to proteasome inhibition, whereas cotreatment with CRM1 inhibitor led to their accumulation in the nucleus. Our results suggest that ubiquitinated proteins are exported from the nucleus to the cytosol in the UBIN-POST complex-dependent manner for the maintenance of nuclear protein homeostasis. PMID:29666234

Nuclear export of ubiquitinated proteins via the UBIN-POST system.

PubMed

Hirayama, Shoshiro; Sugihara, Munechika; Morito, Daisuke; Iemura, Shun-Ichiro; Natsume, Tohru; Murata, Shigeo; Nagata, Kazuhiro

2018-05-01

Although mechanisms for protein homeostasis in the cytosol have been studied extensively, those in the nucleus remain largely unknown. Here, we identified that a protein complex mediates export of polyubiquitinated proteins from the nucleus to the cytosol. UBIN, a ubiquitin-associated (UBA) domain-containing protein, shuttled between the nucleus and the cytosol in a CRM1-dependent manner, despite the lack of intrinsic nuclear export signal (NES). Instead, the UBIN binding protein polyubiquitinated substrate transporter (POST) harboring an NES shuttled UBIN through nuclear pores. UBIN bound to polyubiquitin chain through its UBA domain, and the UBIN-POST complex exported them from the nucleus to the cytosol. Ubiquitinated proteins accumulated in the cytosol in response to proteasome inhibition, whereas cotreatment with CRM1 inhibitor led to their accumulation in the nucleus. Our results suggest that ubiquitinated proteins are exported from the nucleus to the cytosol in the UBIN-POST complex-dependent manner for the maintenance of nuclear protein homeostasis. Copyright © 2018 the Author(s). Published by PNAS.

Switching predominance of organic versus inorganic carbon exports from an intermediate-size subarctic watershed

USGS Publications Warehouse

Dornblaser, Mark M.; Striegl, Robert G.

2015-01-01

Hydrologic exports of dissolved inorganic and organic carbon (DIC, DOC) reflect permafrost conditions in arctic and subarctic river basins. DIC yields in particular, increase with decreased permafrost extent. We investigated the influence of permafrost extent on DIC and DOC yield in a tributary of the Yukon River, where the upper watershed has continuous permafrost and the lower watershed has discontinuous permafrost. Our results indicate that DIC versus DOC predominance switches with interannual changes in water availability and flow routing in intermediate-size watersheds having mixed permafrost coverage. Large water yield and small concentrations from mountainous headwaters and small water yield and high concentrations from lowlands produced similar upstream and downstream carbon yields. However, DOC export exceeded DIC export during high-flow 2011 while DIC predominated during low-flow 2010. The majority of exported carbon derived from near-surface organic sources when landscapes were wet or frozen and from mineralized subsurface sources when infiltration increased.

Sediment transport dynamics in response to large-scale human intervention

NASA Astrophysics Data System (ADS)

Eelkema, Menno; Wang, Zheng Bing

2010-05-01

SEDIMENT TRANSPORT DYNAMICS IN RESPONSE TO LARGE-SCALE HUMAN INTERVENTION M. Eelkema and Z.B. Wang The Eastern Scheldt basin in the southwestern part of the Netherlands is an elongated tidal basin of approximately 50 km in length with an average tidal range of roughly 3 meters at the inlet. Before 1969 A.D., this basin was also connected to two more tidal basins to the north through several narrow, yet deep channels. These connections were closed off with dams in the nineteen sixties in response to the catastrophic flooding in 1953. In the inlet of the Eastern Scheldt a storm-surge barrier was built in order to safeguard against flooding during storms while retaining a part of the tidal influence inside the basin during normal conditions. This barrier was finalized in 1986. The construction of the back-barrier dams in 1965 and 1969 had a significant impact on the tidal hydrodynamics and sediment transport (Van den Berg, 1986). The effects of these interventions were still ongoing when the hydrodynamic regime was altered again by the construction of the storm-surge barrier between 1983 and 1986. This research aims to describe the hydrodynamic and morphodynamic evolution of the Eastern Scheldt between 1953 and 1983, before construction of the storm-surge barrier had started. An analysis is made of the manner in which the back-barrier dams changed the tidal flow through the basin, and how these altered hydrodynamics influenced the sediment transport and morphology. This analysis consists first of all of a description of the observed hydrodynamical and bathymetrical changes. Second, these observations are used as input for a process-based hydrodynamic model (Delft3D), which is applied in order to gain more insight into the changes in sediment transport patterns. The model is used to simulate the situations before and after the closures of the connections between the Eastern Scheldt and the basins north of it In the decades before 1965, the Eastern Scheldt exported large quantities of sediment towards sea through its inlet. This export was estimated to be roughly 2 to 3 million m3 per year, and was observable as deepening channels inside the basin, and a growing ebb-tidal delta. The implementation of the dams caused a significant increase in tidal prism, while at the same time they stopped the residual flow of water from the Eastern Scheldt towards the northern basins. The increase in tidal prism was observable in the response of bathymetry; the rates of channel deepening and ebb-tidal delta growth both increased. Analysis of tidal flow measurements and model output show a persistent trend for sediment transport towards and out of the Eastern Scheldt's inlet. This export is caused by both the strong ebb-directed asymmetry in the tidal flow as well as higher sediment concentrations during ebb. The construction of the back-barrier dams only amplified this export by cutting off the residual import of flow and by causing the basin to be out of equilibrium even more than it apparently already was. References Van den Berg, J.H., 1986. Aspects of Sediment- and Morphodynamics of Subtidal Deposits of the Oosterschelde (the Netherlands). Rijkswaterstaat Communications, no. 43/1986, The Hague.

Quantifying the potential export flows of used electronic products in Macau: a case study of PCs.

PubMed

Yu, Danfeng; Song, Qingbin; Wang, Zhishi; Li, Jinhui; Duan, Huabo; Wang, Jinben; Wang, Chao; Wang, Xu

2017-12-01

The used electronic product (UEP) has attracted the worldwide attentions because part of e-waste may be exported from developed countries to developing countries in the name of UEP. On the basis of large foreign trade data of electronic products (e-products), this study adopted the trade data approach (TDA) to quantify the potential exports of UEP in Macau, taking a case study of personal computers (PCs). The results show that the desktop mainframes, LCD monitors, and CRT monitors have more low-unit-value trades with higher trade volumes in the past 10 years, while the laptop and tablet PCs, as the newer technologies, owned the higher ratios of the high-unit-value trades. During the period of 2005-2015, the total mean exports for used laptop and tablet PCs, desktop mainframes, and LCD monitors were approximately 18,592, 79,957, and 43,177 units, respectively, while the possible export volume of used CRT monitors was higher, up to 430,098 units in 2000-2010. Noticed that these potential export volumes could be the lower bound because not all used PCs may be shipped using the PC trade code. For all the four kinds of used PCs, the majority (61.6-98.82%) of the export volumes have gone to Hong Kong, followed by Mainland China and Taiwan. Since 2011, there was no CRT monitor export; however, the other kinds of used PC exports will still exist in Macau in the future. The outcomes are helpful to understand and manage the current export situations of used products in Macau, and can also provide a reference for other countries and regions.

An improved export coefficient model to estimate non-point source phosphorus pollution risks under complex precipitation and terrain conditions.

PubMed

Cheng, Xian; Chen, Liding; Sun, Ranhao; Jing, Yongcai

2018-05-15

To control non-point source (NPS) pollution, it is important to estimate NPS pollution exports and identify sources of pollution. Precipitation and terrain have large impacts on the export and transport of NPS pollutants. We established an improved export coefficient model (IECM) to estimate the amount of agricultural and rural NPS total phosphorus (TP) exported from the Luanhe River Basin (LRB) in northern China. The TP concentrations of rivers from 35 selected catchments in the LRB were used to test the model's explanation capacity and accuracy. The simulation results showed that, in 2013, the average TP export was 57.20 t at the catchment scale. The mean TP export intensity in the LRB was 289.40 kg/km 2 , which was much higher than those of other basins in China. In the LRB topographic regions, the TP export intensity was the highest in the south Yanshan Mountains and was followed by the plain area, the north Yanshan Mountains, and the Bashang Plateau. Among the three pollution categories, the contribution ratios to TP export were, from high to low, the rural population (59.44%), livestock husbandry (22.24%), and land-use types (18.32%). Among all ten pollution sources, the contribution ratios from the rural population (59.44%), pigs (14.40%), and arable land (10.52%) ranked as the top three sources. This study provides information that decision makers and planners can use to develop sustainable measures for the prevention and control of NPS pollution in semi-arid regions.

Storage and export of organic matter in a headwater stream: responses to long-term detrital manipulations

Treesearch

Sue L. Eggert; J. Bruce Wallace; Judy L. Meyer; Jackson R. Webster

2012-01-01

Riparian habitats provide organic matter inputs that influence stream biota and ecosystem processes in forested watersheds. Over a 13-yr period, we examined the effects of litter exclusion, small- and large-wood removal, and the addition of leaf species of varying detrital quality on organic matter standing crop and export of organic and inorganic particles in a high-...

U. S. plastics demand drops sharply

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

According to the Society of the Plastics Industry, plastics demand dropped sharply in the U.S. during second-quarter 1980. U.S. exports of themoplastics are down slightly from year-ago levels, and PVC and low-density polyethylene (LDPE) exports are increasing strongly, but strong exports can not offset a weak domestic market. The weakness in domestic PVC sales is due mostly to large drops in contruction pipe (-49%) and automotive uses, its leading markets, in the last year. LDPE sales have dropped 3% over the year, and 8% in film, LPDE's largest market. Polypropylene's two largest U.S. markets, molding and fibers, have also droppedmore » sharply. Epoxy resin showed a May 1979 to May 1980 gain of 28% in exports, but three other thermosets, polyesters, urea-melamine, and phenolics, have dropped sharply since May 1979.« less

Tectonic Control of the Acid and Alkalinity Budgets of Chemical Weathering

NASA Astrophysics Data System (ADS)

Torres, M. A.; Dellinger, M.; Clark, K. E.; West, A. J.; Paris, G.; Bouchez, J.; Ponton, C.; Feakins, S. J.; Galy, V.; Hilton, R. G.; Adkins, J. F.

2016-12-01

The exchange of carbon between the rock reservoir and the ocean/atmosphere system modulates Earth's climate over geologic timescales. Central to our current conceptualization of this geologic C cycle is a mechanistic link between input and output fluxes that limits imbalances and prevents extreme variations in atmospheric pCO2. However, a quantitative understanding of how C cycle balance is maintained remains elusive due to the competition and co-variation between many distinct biogeochemical reactions. Here, we turn to river systems draining Andes/Amazon and other modern mountain ranges to inform our understanding of how major orogenies affect key C cycle fluxes.Globally, rivers draining active mountain ranges transport massive quantities of sulfate, alkalinity, and particulate organic carbon. Consequently, defining the exact effect of tectonic uplift on both atmospheric pCO2 and pO2 requires the careful partitioning of these fluxes between competing C and O cycle reactions. Using a suite of isotopic and trace element proxies, we find that the large mass fluxes exported by mountain rivers do not necessarily translate into a large C sink due to the oxidative weathering of trace reactive phases (e.g., pyrite). Our results also imply that mountain weathering may be an important O2 sink. The applicability and implications of these results are explored using reactive-transport modeling and a new carbonate-system framework for the links between C cycle reactions and atmospheric pCO2.

A small quantity of sodium arsenite will kill large cull hardwoods

Treesearch

Francis M. Rushmore

1956-01-01

Although it is well known that sodium arsenite is an effective silvicide, forestry literature contains little information about the minimum quantities of this chemical that are required to kill large cull trees. Such information would be of value because if small quantities of a chemical will produce satisfactory results, small holes or frills in the tree will hold it...

Humic substances-part 7: the biogeochemistry of dissolved organic carbon and its interactions with climate change.

PubMed

Porcal, Petr; Koprivnjak, Jean-François; Molot, Lewis A; Dillon, Peter J

2009-09-01

Dissolved organic matter, measured as dissolved organic carbon (DOC), is an important component of aquatic ecosystems and of the global carbon cycle. It is known that changes in DOC quality and quantity are likely to have ecological repercussions. This review has four goals: (1) to discuss potential mechanisms responsible for recent changes in aquatic DOC concentrations; (2) to provide a comprehensive overview of the interactions between DOC, nutrients, and trace metals in mainly boreal environments; (3) to explore the impact of climate change on DOC and the subsequent effects on nutrients and trace metals; and (4) to explore the potential impact of DOC cycling on climate change. We review recent research on the mechanisms responsible for recent changes in aquatic DOC concentrations, DOC interactions with trace metals, N, and P, and on the possible impacts of climate change on DOC in mainly boreal lakes. We then speculate on how climate change may affect DOC export and in-lake processing and how these changes might alter nutrient and metal export and processing. Furthermore, the potential impacts of changing DOC cycling patterns on climate change are examined. It has been noted that DOC concentrations in lake and stream waters have increased during the last 30 years across much of Europe and North America. The potential reasons for this increase include increasing atmospheric CO(2) concentration, climate warming, continued N deposition, decreased sulfate deposition, and hydrological changes due to increased precipitation, droughts, and land use changes. Any change in DOC concentrations and properties in lakes and streams will also impact the acid-base chemistry of these waters and, presumably, the biological, chemical, and photochemical reactions taking place. For example, the interaction of trace metals with DOC may be significantly altered by climate change as organically complexed metals such as Cu, Fe, and Al are released during photo-oxidation of DOC. The production and loss of DOC as CO(2) from boreal lakes may also be affected by changing climate. Climate change is unlikely to be uniform spatially with some regions becoming wetter while others become drier. As a result, rates of change in DOC export and concentrations will vary regionally and the changes may be non-linear. Climate change models predict that higher temperatures are likely to occur over most of the boreal forests in North America, Europe, and Asia over the next century. Climate change is also expected to affect the severity and frequency of storm and drought events. Two general climate scenarios emerge with which to examine possible DOC trends: warmer and wetter or warmer and drier. Increasing temperature and hydrological changes (specifically, runoff) are likely to lead to changes in the quality and quantity of DOC export from terrestrial sources to rivers and lakes as well as changes in DOC processing rates in lakes. This will alter the quality and concentrations of DOC and its constituents as well as its interactions with trace metals and the availability of nutrients. In addition, export rates of nutrients and metals will also change in response to changing runoff. Processing of DOC within lakes may impact climate depending on the extent to which DOC is mineralized to dissolved inorganic carbon (DIC) and evaded to the atmosphere or settles as particulate organic carbon (POC) to bottom sediments and thereby remaining in the lake. The partitioning of DOC between sediments and the atmosphere is a function of pH. Decreased DOC concentrations may also limit the burial of sulfate, as FeS, in lake sediments, thereby contributing acidity to the water by increasing the formation of H(2)S. Under a warmer and drier scenario, if lake water levels fall, previously stored organic sediments may be exposed to greater aeration which would lead to greater CO(2) evasion to the atmosphere. The interaction of trace metals with DOC may be significantly altered by climate change. Iron enhances the formation of POC during irradiation of lake water with UV light and therefore may be an important pathway for transfer of allochthonous DOC to the sediments. Therefore, changing Fe/DOC ratios could affect POC formation rates. If climate change results in altered DOC chemistry (e.g., fewer and/or weaker binding sites) more trace metals could be present in their toxic and bioavailable forms. The availability of nutrients may be significantly altered by climate change. Decreased DOC concentrations in lakes may result in increased Fe colloid formation and co-incident loss of adsorbable P from the water column. Climate change expressed as changes in runoff and temperature will likely result in changes in aquatic DOC quality and concentration with concomitant effects on trace metals and nutrients. Changes in the quality and concentration of DOC have implications for acid-base chemistry and for the speciation and bioavailability of certain trace metals and nutrients. Moreover, changes in DOC, metals, and nutrients are likely to drive changes in rates of C evasion and storage in lake sediments. The key controls on allochthonous DOC quality, quantity, and catchment export in response to climate change are still not fully understood. More detailed knowledge of these processes is required so that changes in DOC and its interactions with nutrients and trace metals can be better predicted based on changes caused by changing climate. More studies are needed concerning the effects of trace metals on DOC, the effects of changing DOC quality and quantity on trace metals and nutrients, and how runoff and temperature-related changes in DOC export affect metal and nutrient export to rivers and lakes.

Measuring fallout radionuclides to constrain the origin and the dynamics of suspended sediment in an agricultural drained catchment (Loire River basin, France)

NASA Astrophysics Data System (ADS)

Le Gall, Marion; Evrard, Olivier; Foucher, Anthony; Laceby, J. Patrick; Salvador-Blanes, Sébastien; Lefèvre, Irène; Cerdan, Olivier; Ayrault, Sophie

2015-04-01

Soil erosion reaches problematic levels in agricultural areas of Northwestern Europe where tile drains may accelerate sediment transfer to rivers. This supply of large quantities of fine sediment to the river network leads to the degradation of water quality by increasing water turbidity, filling reservoirs and transporting contaminants. Agricultural patterns and landscapes features have been largely modified by human activities during the last century. To investigate erosion and sediment transport in lowland drained areas, a small catchment, the Louroux (24 km²), located in the French Loire River basin was selected. In this catchment, channels have been reshaped and more than 220 tile drains outlets have been installed after World War II. As a result, soil erosion and sediment fluxes strongly increased. Sediment supply needs to be better understood by quantifying the contribution of sources and the residence times of particles within the catchment. To this end, a network of river monitoring stations was installed, and fallout radionuclides (Cs-137, excess Pb-210 and Be-7) were measured in rainwater (n=3), drain tile outlets (n=4), suspended sediment (n=15), soil surface (n=30) and channel bank samples (n=15) between January 2013 and February 2014. Cs-137 concentrations were used to quantify the contribution of surface vs. subsurface sources of sediment. Results show a clear dominance of particles originating from surface sources (99 ± 1%). Be-7 and excess Pb-210 concentrations and calculation of Be-7/excess Pb-210 ratios in rainfall and suspended sediment samples were used to estimate percentages of recently eroded sediment in rivers. The first erosive winter storm mainly exported sediment depleted in Be-7 that likely deposited on the riverbed during the previous months. Then, during the subsequent floods, sediment was directly eroded and exported to the catchment outlet. Our results show the added value of combining spatial and temporal tracers to characterize and quantify sources of sediment and particle transport processes within an agricultural catchment.

Catchment scale molecular composition of hydrologically mobilized dissolved organic matter

NASA Astrophysics Data System (ADS)

Raeke, Julia; Lechtenfeld, Oliver J.; Oosterwoud, Marieke R.; Bornmann, Katrin; Tittel, Jörg; Reemtsma, Thorsten

2016-04-01

Increasing concentrations of dissolved organic matter (DOM) in rivers of temperate catchments in Europe and North Amerika impose new technical challenges for drinking water production. The driving factors for this decadal increase in DOM concentration are not conclusive and changes in annual temperatures, precipitation and atmospheric deposition are intensely discussed. It is known that the majority of DOM is released by few but large hydrologic events, mobilizing DOM from riparian wetlands for export by rivers and streams. The mechanisms of this mobilization and the resulting molecular composition of the released DOM may be used to infer long-term changes in the biogeochemistry of the respective catchment. Event-based samples collected over two years from streams in three temperate catchments in the German mid-range mountains were analyzed after solid-phase extraction of DOM for their molecular composition by ultra-high resolution mass spectrometry (FT-ICR MS). Hydrologic conditions, land use and water chemistry parameters were used to complement the molecular analysis. The molecular composition of the riverine DOM was strongly dependent on the magnitude of the hydrologic events, with unsaturated, oxygen-enriched compounds being preferentially mobilized by large events. This pattern is consistent with an increase in dissolved iron and aluminum concentrations. In contrast, the relative proportions of nitrogen and sulfur bearing compounds increased with an increased agricultural land use but were less affected by the mobilization events. Co-precipitation experiments with colloidal aluminum showed that unsaturated and oxygen-rich compounds are preferentially removed from the dissolved phase. The precipitated compounds thus had similar chemical characteristics as compared to the mobilized DOM from heavy rain events. Radiocarbon analyses also indicated that this precipitated fraction of DOM was of comparably young radiocarbon age. DOM radiocarbon from field samples showed that also the event-mobilized DOM had higher radiocarbon content. Overall, hydrology not only controls the quantity of exported carbon from temperate catchments but also strongly influences the molecular composition by mobilizing distinct compound classes in conjunction with dissolved iron and aluminum. From these results future compositional changes in temperate river DOM can be assessed, given an expected increase in the magnitude of hydrologic events, and technical advice for drinking water production may be inferred.

Early results from an effort to downscale a global dissolved inorganic nitrogen model to achieve a regional assessment of nitrogen dynamics in the Columbia River Basin

NASA Astrophysics Data System (ADS)

Miller, C. C.; Harrison, J.

2013-12-01

Excessive nitrogen (N) export to coastal systems has increased dramatically since the early 20th century. The increase in N has been linked to significant environmental impacts such as eutrophication, fish kills, and harmful algal blooms and is caused in part by the increasing use and quantity of synthetic fertilizer on farmland. Significant portions of both the Willamette River Valley in Oregon and the Palouse region of eastern Washington are agricultural land, approximately 20% and 57% respectively. Nitrogen in the form of dissolved inorganic nitrogen (DIN) can leach from farms and pasture land into ground and surface water systems. This leaching, combined with DIN in runoff, contributes to the environmental degradation of both waterways (i.e. streams, rivers) and coastal estuaries. Because of this it is important to understand what effects changes in DIN application will have on water quality and DIN export to the coast. DIN export data, retrieved from the U.S. Geological Survey National Water Information System, was analyzed for 23 major subbasins in the Columbia River Basin (CRB) and estimates DIN export (per area yield) ranging from 5.0 to 883.1 kg N km-2 yr-1. Here we present early results from our effort to downscale the Global Nutrient Export from WaterSheds (Global NEWS) DIN model for application within the Columbia River Basin (CRB). This first attempt at downscaling Global NEWS is missing some key higher-resolution N inputs for the model as well as accurate dam retention and runoff factors which could account for the low correlation between model output and observed data (R2 = 0.21).Our regional model predicts DIN yields ranging from 7.9 to 1146.6 kg N km-2 yr-1. Both the model output and observed data predict the highest per area DIN yields occurring in the Willamette river subbasin. Total DIN export to the coast was modeled as 0.06 Tg N yr-1 compared to 0.07 Tg N yr-1 calculated from the measured data. Based on current model inputs biological N2 fixation is the dominant source of DIN in 15 of the 23 subbasins, including the CRB as a whole. N fertilizer is the dominant source of anthropogenic DIN export among the rest of the subbasins. With improvements to the model inputs we expect to see a higher correlation between the measured data and the model output.

Development of a Charged-Particle Accumulator Using an RF Confinement Method

DTIC Science & Technology

2007-03-12

antiparticles (antiprotons and positrons), and to produce a large quantity of antimatter . Antihydrogen atoms have recently been produced using Penning...ultimate goal is to trap a large number of antiparticles and to produce a large quantity of antimatter . 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF

Regional fibrocartilage variations in human anterior cruciate ligament tibial insertion: a histological three-dimensional reconstruction.

PubMed

Dai, Can; Guo, Lin; Yang, Liu; Wu, Yi; Gou, Jingyue; Li, Bangchun

2015-02-01

We studied anterior cruciate ligament (ACL) tibial insertion architecture in humans and investigated regional differences that could suggest unequal force transmission from ligament to bone. ACL tibial insertions were processed histologically. With Photoshop software, digital images taken from the histological slides were collaged, contour lines were drawn, and different gray values were filled based on the structure. The data were exported to Amira software for three-dimensional reconstruction. The uncalcified fibrocartilage (UF) layer was divided into three regions: lateral, medial and posterior according to the architecture. The UF zone was significantly thicker laterally than medially or posteriorly (p < 0.05). Similarly, the calcified fibrocartilage (CF) thickness was significantly greater in the lateral part of the enthesis compared to the medial and posterior parts (p < 0.05). The UF quantity (more UF laterally) corresponding to the CF quantity (more CF laterally) at the ACL tibial insertion provides further evidence suggesting that the load transferred from the ACL to the tibia was greater laterally than medially and posteriorly.

The pulse of driftwood export from a very large forested river basin over multiple time scales, Slave River, Canada

NASA Astrophysics Data System (ADS)

Kramer, Natalie; Wohl, Ellen; Hess-Homeier, Brooke; Leisz, Stephen

2017-03-01

This study presents a case study of large wood transport on the great Slave River in northern Canada with the objective to better understand the processes of and variability in pulsed wood fluxes from large forested catchments. We use a varied approach, integrating field characterization of wood, historical anecdotes, repeat aerial imagery of stored wood, and time-lapse imagery of moving wood, for a robust analysis and synthesis of processes behind pulsed wood flux, from yearly uncongested export to rare congested wood floods. Repeat monitoring of known sites of temporary storage with new or historic imagery proved to be a very useful tool for constraining wood flux histories. Pulsed wood export on the Slave River is not an artifact of episodic recruitment from major up-basin disturbances, but rather reflects decadal- to half-century-scale discharge patterns that redistribute wood recruited from channel migration and bank slumping. We suggest that the multiyear flow history is of paramount importance for estimating wood flux magnitude, followed in declining importance by the yearly sequence of peaks and the magnitude and characteristics of the rising limb of individual floods.

Late summer carbon export and remineralisation in the Southern Ocean determined with the combined 234Th and particulate biogenic Ba tracers

NASA Astrophysics Data System (ADS)

Planchon, F.; Cavagna, A.-J.; Cardinal, D.; André, L.; Dehairs, F.

2012-04-01

As part of the Bonus-GoodHope expedition (late summer 2008; Feb-March) in the Atlantic sector of the Southern Ocean, we present combined 234Th and biogenic particulate barium (Baxs) results. These data are used to estimate the export of particulate organic carbon (POC) from the upper mixed layer and the impact of twilight zone remineralisation on the carbon export. Total 234Th activity in surface waters is depleted relative to its parent nuclide 238U (234Th/238U ratio ranging from 0.74 to 0.91), while equilibrium is reached at the base of the surface mixed-layer. The export fluxes of 234Th from the 100m horizon, as estimated using steady state (SS) and non steady state (NSS) models, reveal different latitudinal trends. SS 234Th export varies from 496 dpm m-2 d-1 in the subtropical domain of the Cape Basin to 1195 dpm m-2 d-1 close to the Polar Front (PF). NSS export representative for a 15 to 22 day period preceding the cruise, is consistently less than SS export in the sub-Antarctic Zone (SAZ, 150 dpm m-2 d-1) and the Polar Frontal Zone (PFZ, 440 dpm m-2 d-1) but is similar further south in the Antarctic Zone (AZ, 1217 dpm m-2 d-1) and the northern Weddell Gyre (N-WG; 757 dpm m-2 d-1). This reflects temporal variability of export north of the PF, while south of the PF the export system appears to be in steady state during this late summer situation. The POC:Th ratio of large (>53 µm) particles collected below the surface mixed layer increases from 1.7 µmol dpm-1 in the STZ to a maximum of 4.8 µmol dpm-1 at the Southern Antarctic Circumpolar Current Front (SACCF), suggesting a southward increase of the contribution of larger cells, such as diatoms, to sinking material. Using these POC:Th ratios we calculate that the POC SS export from the 100m horizon reaches 0.9-1.7 mmol m-2 d-1 in the STZ and the SAZ, 2.6-4.7 mmol m-2 d-1 in the PFZ, and 3.3 mmol m-2 d-1 in the N-WG. Below the export layer, in the mesopelagic zone (100-600 m), 234Th activities generally reach equilibrium with 238U, but sometimes also are in large excess (234Th/238U ratio > to 1.1). Such activity excesses reflect intense remineralisation/disaggregation of 234Th-bearing particles which is estimated to attenuate the original POC export flux by close to 100%. Increased biogenic particulate Ba (Baxs) contents in the mesopelagic zone, indicate enhanced remaineralisation of organic matter, and in general overlap with the areas of excess 234Th. Excluding two outliers, we found a general positive correlation for mesopelagic waters between POC remineralisation estimated from Baxs inventories and from 234Th excess. Our results indicate that POC export production in the Southern Ocean is strongly attenuated in the mesopelagic waters.

Proteome-wide search for functional motifs altered in tumors: Prediction of nuclear export signals inactivated by cancer-related mutations

PubMed Central

Prieto, Gorka; Fullaondo, Asier; Rodríguez, Jose A.

2016-01-01

Large-scale sequencing projects are uncovering a growing number of missense mutations in human tumors. Understanding the phenotypic consequences of these alterations represents a formidable challenge. In silico prediction of functionally relevant amino acid motifs disrupted by cancer mutations could provide insight into the potential impact of a mutation, and guide functional tests. We have previously described Wregex, a tool for the identification of potential functional motifs, such as nuclear export signals (NESs), in proteins. Here, we present an improved version that allows motif prediction to be combined with data from large repositories, such as the Catalogue of Somatic Mutations in Cancer (COSMIC), and to be applied to a whole proteome scale. As an example, we have searched the human proteome for candidate NES motifs that could be altered by cancer-related mutations included in the COSMIC database. A subset of the candidate NESs identified was experimentally tested using an in vivo nuclear export assay. A significant proportion of the selected motifs exhibited nuclear export activity, which was abrogated by the COSMIC mutations. In addition, our search identified a cancer mutation that inactivates the NES of the human deubiquitinase USP21, and leads to the aberrant accumulation of this protein in the nucleus. PMID:27174732

Estimating the Cross-Shelf Export of Riverine Materials: Part 2. Estimates of Global Freshwater and Nutrient Export

NASA Astrophysics Data System (ADS)

Izett, Jonathan G.; Fennel, Katja

2018-02-01

Rivers deliver large amounts of fresh water, nutrients, and other terrestrially derived materials to the coastal ocean. Where inputs accumulate on the shelf, harmful effects such as hypoxia and eutrophication can result. In contrast, where export to the open ocean is efficient riverine inputs contribute to global biogeochemical budgets. Assessing the fate of riverine inputs is difficult on a global scale. Global ocean models are generally too coarse to resolve the relatively small scale features of river plumes. High-resolution regional models have been developed for individual river plume systems, but it is impractical to apply this approach globally to all rivers. Recently, generalized parameterizations have been proposed to estimate the export of riverine fresh water to the open ocean (Izett & Fennel, 2018, https://doi.org/10.1002/2017GB005667; Sharples et al., 2017, https://doi.org/10.1002/2016GB005483). Here the relationships of Izett and Fennel, https://doi.org/10.1002/2017GB005667 are used to derive global estimates of open-ocean export of fresh water and dissolved inorganic silicate, dissolved organic carbon, and dissolved organic and inorganic phosphorus and nitrogen. We estimate that only 15-53% of riverine fresh water reaches the open ocean directly in river plumes; nutrient export is even less efficient because of processing on continental shelves. Due to geographic differences in riverine nutrient delivery, dissolved silicate is the most efficiently exported to the open ocean (7-56.7%), while dissolved inorganic nitrogen is the least efficiently exported (2.8-44.3%). These results are consistent with previous estimates and provide a simple way to parameterize export to the open ocean in global models.

Emissions embodied in global trade have plateaued due to structural changes in China

NASA Astrophysics Data System (ADS)

Pan, Chen; Peters, Glen P.; Andrew, Robbie M.; Korsbakken, Jan Ivar; Li, Shantong; Zhou, Dequn; Zhou, Peng

2017-09-01

Fluvial carbon export from a lowland Amazonian rainforest in relation to atmospheric fluxes

NASA Astrophysics Data System (ADS)

Vihermaa, Leena E.; Waldron, Susan; Domingues, Tomas; Grace, John; Cosio, Eric G.; Limonchi, Fabian; Hopkinson, Chris; da Rocha, Humberto Ribeiro; Gloor, Emanuel

2016-12-01

We constructed a whole carbon budget for a catchment in the Western Amazon Basin, combining drainage water analyses with eddy covariance (EC) measured terrestrial CO2 fluxes. As fluvial C export can represent permanent C export it must be included in assessments of whole site C balance, but it is rarely done. The footprint area of the flux tower is drained by two small streams ( 5-7 km2) from which we measured the dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), particulate organic carbon (POC) export, and CO2 efflux. The EC measurements showed the site C balance to be +0.7 ± 9.7 Mg C ha-1 yr-1 (a source to the atmosphere) and fluvial export was 0.3 ± 0.04 Mg C ha-1 yr-1. Of the total fluvial loss 34% was DIC, 37% DOC, and 29% POC. The wet season was most important for fluvial C export. There was a large uncertainty associated with the EC results and with previous biomass plot studies (-0.5 ± 4.1 Mg C ha-1 yr-1); hence, it cannot be concluded with certainty whether the site is C sink or source. The fluvial export corresponds to only 3-7% of the uncertainty related to the site C balance; thus, other factors need to be considered to reduce the uncertainty and refine the estimated C balance. However, stream C export is significant, especially for almost neutral sites where fluvial loss may determine the direction of the site C balance. The fate of C downstream then dictates the overall climate impact of fluvial export.

Aggregating land use quantity and intensity to link water quality in upper catchment of Miyun Reservoir

NASA Astrophysics Data System (ADS)

Xu, E.

2015-12-01

Land use is closely related to hydrological and biochemical processes influencing the water quality. Quantifying relationship between both of them can help effectively manage land use to improve water quality. Previous studies majorly utilized land use quantity as an indicator to link water quality parameters, which lacked an insight to the influence of land use intensity. Taking upper catchment of Miyun Reservoir as a case study, we proposed a method of aggregating land use quantity and intensity to build a new land use indicator and investigated its explanation empower on water quality. Six nutrient concentrations from 52 sub-watersheds covering the whole catchment were used to characterize spatial distributions of water eutrophication. Based on spatial techniques and empirical conversion coefficients, combined remote sensing with socio-economic statistical data, land use intensity was measured and mapped visually. Then the new land use indicator was calculated and linked to nutrient concentrations by Pearson correlation coefficients. Results demonstrated that our new land use indicator incorporating intensity information can quantify the potential different nutrients exporting abilities from land uses. Comparing to traditional indicators only characterized by land use quantity, most Pearson correlation coefficients between new indicator and water nutrient concentrations increased. New information enhanced the explanatory power of land use on water nutrient concentrations. Then it can help better understand the impact of land use on water quality and guide land use management for supporting decision making.

A comparative study of allowable pesticide residue levels on produce in the United States

PubMed Central

2012-01-01

Background The U.S. imports a substantial and increasing portion of its fruits and vegetables. The U.S. Food and Drug Administration currently inspects less than one percent of import shipments. While countries exporting to the U.S. are expected to comply with U.S. tolerances, including allowable pesticide residue levels, there is a low rate of import inspections and few other incentives for compliance. Methods This analysis estimates the quantity of excess pesticide residue that could enter the U.S. if exporters followed originating country requirements but not U.S. pesticide tolerances, for the top 20 imported produce items based on quantities imported and U.S. consumption levels. Pesticide health effects data are also shown. Results The model estimates that for the identified items, 120 439 kg of pesticides in excess of U.S. tolerances could potentially be imported to the U.S., in cases where U.S. regulations are more protective than those of originating countries. This figure is in addition to residues allowed on domestic produce. In the modeling, the top produce item, market, and pesticide of concern were oranges, Chile, and Zeta-Cypermethrin. Pesticides in this review are associated with health effects on 13 body systems, and some are associated with carcinogenic effects. Conclusions There is a critical information gap regarding pesticide residues on produce imported to the U.S. Without a more thorough sampling program, it is not possible accurately to characterize risks introduced by produce importation. The scenario presented herein relies on assumptions, and should be considered illustrative. The analysis highlights the need for additional investigation and resources for monitoring, enforcement, and other interventions, to improve import food safety and reduce pesticide exposures in originating countries. PMID:22293037

Macro policy responses to oil booms and busts in the United Arab Emirates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Mutawa, A.K.

1991-01-01

The effects of oil shocks and macro policy changes in the United Arab Emirates are analyzed. A theoretical model is developed within the framework of the Dutch Disease literature. It contains four unique features that are applicable to the United Arab Emirates' economy. There are: (1) the presence of a large foreign labor force; (2) OPEC's oil export quotas; (3) the division of oil profits; and (4) the important role of government expenditures. The model is then used to examine the welfare effects of the above-mentioned shocks. An econometric model is then specified that conforms to the analytical model. Inmore » the econometric model the method of principal components' is applied owing to the undersized sample data. The principal components methodology is used in both the identification testing and the estimation of the structural equations. The oil and macro policy shocks are then simulated. The simulation results show that an oil-quantity boom leads to a higher welfare gain than an oil-price boom. Under certain circumstances, this finding is also confirmed by the comparative statistics that follow from the analytical model.« less

Maximum Entropy for the International Division of Labor.

PubMed

Lei, Hongmei; Chen, Ying; Li, Ruiqi; He, Deli; Zhang, Jiang

2015-01-01

As a result of the international division of labor, the trade value distribution on different products substantiated by international trade flows can be regarded as one country's strategy for competition. According to the empirical data of trade flows, countries may spend a large fraction of export values on ubiquitous and competitive products. Meanwhile, countries may also diversify their exports share on different types of products to reduce the risk. In this paper, we report that the export share distribution curves can be derived by maximizing the entropy of shares on different products under the product's complexity constraint once the international market structure (the country-product bipartite network) is given. Therefore, a maximum entropy model provides a good fit to empirical data. The empirical data is consistent with maximum entropy subject to a constraint on the expected value of the product complexity for each country. One country's strategy is mainly determined by the types of products this country can export. In addition, our model is able to fit the empirical export share distribution curves of nearly every country very well by tuning only one parameter.

Maximum Entropy for the International Division of Labor

PubMed Central

Lei, Hongmei; Chen, Ying; Li, Ruiqi; He, Deli; Zhang, Jiang

2015-01-01

As a result of the international division of labor, the trade value distribution on different products substantiated by international trade flows can be regarded as one country’s strategy for competition. According to the empirical data of trade flows, countries may spend a large fraction of export values on ubiquitous and competitive products. Meanwhile, countries may also diversify their exports share on different types of products to reduce the risk. In this paper, we report that the export share distribution curves can be derived by maximizing the entropy of shares on different products under the product’s complexity constraint once the international market structure (the country-product bipartite network) is given. Therefore, a maximum entropy model provides a good fit to empirical data. The empirical data is consistent with maximum entropy subject to a constraint on the expected value of the product complexity for each country. One country’s strategy is mainly determined by the types of products this country can export. In addition, our model is able to fit the empirical export share distribution curves of nearly every country very well by tuning only one parameter. PMID:26172052

Latitudinal distributions of particulate carbon export across the North Western Atlantic Ocean

NASA Astrophysics Data System (ADS)

Puigcorbé, Viena; Roca-Martí, Montserrat; Masqué, Pere; Benitez-Nelson, Claudia; Rutgers van der Loeff, Michiel; Bracher, Astrid; Moreau, Sebastien

2017-11-01

234Th-derived carbon export fluxes were measured in the Atlantic Ocean under the GEOTRACES framework to evaluate basin-scale export variability. Here, we present the results from the northern half of the GA02 transect, spanning from the equator to 64°N. As a result of limited site-specific C/234Th ratio measurements, we further combined our data with previous work to develop a basin wide C/234Th ratio depth curve. While the magnitude of organic carbon fluxes varied depending on the C/234Th ratio used, latitudinal trends were similar, with sizeable and variable organic carbon export fluxes occurring at high latitudes and low to negligible fluxes occurring in oligotrophic waters. Our results agree with previous studies, except at the boundaries between domains, where fluxes were relatively enhanced. Three different models were used to obtain satellite-derived net primary production (NPP). In general, NPP estimates had similar trends along the transect, but there were significant differences in the absolute magnitude depending on the model used. Nevertheless, organic carbon export efficiencies were generally < 25%, with the exception of a few stations located in the transition area between the riverine and the oligotrophic domains and between the oligotrophic and the temperate domains. Satellite-derived organic carbon export models from Dunne et al. (2005) (D05), Laws et al. (2011) (L11) and Henson et al. (2011) (H11) were also compared to our 234Th-derived carbon exports fluxes. D05 and L11 provided estimates closest to values obtained with the 234Th approach (within a 3-fold difference), but with no clear trends. The H11 model, on the other hand, consistently provided lower export estimates. The large increase in export data in the Atlantic Ocean derived from the GEOTRACES Program, combined with satellite observations and modeling efforts continue to improve the estimates of carbon export in this ocean basin and therefore reduce uncertainty in the global carbon budget. However, our results also suggest that tuning export models and including biological parameters at a regional scale is necessary for improving satellite-modeling efforts and providing export estimates that are more representative of in situ observations.

Bulky waste quantities and treatment methods in Denmark.

PubMed

Larsen, Anna W; Petersen, Claus; Christensen, Thomas H

2012-02-01

Bulky waste is a significant and increasing waste stream in Denmark. However, only little research has been done on its composition and treatment. In the present study, data about collection methods, waste quantities and treatment methods for bulky waste were obtained from two municipalities. In addition a sorting analysis was conducted on combustible waste, which is a major fraction of bulky waste in Denmark. The generation of bulky waste was found to be 150-250 kg capita(-1) year(-1), and 90% of the waste was collected at recycling centres; the rest through kerbside collection. Twelve main fractions were identified of which ten were recyclable and constituted 50-60% of the total quantity. The others were combustible waste for incineration (30-40%) and non-combustible waste for landfilling (10%). The largest fractions by mass were combustible waste, bricks and tile, concrete, non-combustible waste, wood, and metal scrap, which together made up more than 90% of the total waste amounts. The amount of combustible waste could be significantly reduced through better sorting. Many of the waste fractions consisted of composite products that underwent thorough separation before being recycled. The recyclable materials were in many cases exported to other countries which made it difficult to track their destination and further treatment.

U.S. Geological Survey Studies of Energy Resources in Sub-Saharan Africa

USGS Publications Warehouse

,

1997-01-01

The U.S. Government and the American public need access to information on energy resources in sub-Saharan Africa.Sub-Saharan Africa (mostly Nigeria) produces 5 percent of the world's oil, while supplying the United States with 15 percent of our imports (Energy Information Administration). In the next 10 years, sub-Saharan oil and gas will become increasingly more important to the export market. New discoveries in offshore provinces of West Africa ensure a bright future for the region. Projections indicate that increased oil production in sub-Saharan Africa will far outpace the growth of intraregional consumption, providing greater quantities of oil for export (Forman, 1996). Also, West Africa, although a marginal supplier of liquefied natural gas (LNG) today, will become an important LNG source to the international market by the year 2000 (Oil & Gas Journal, 1996). The United States needs up-to-date information about petroleum resources and the energy balance within the region to predict the future role of sub-Saharan Africa as a major oil and gas exporter. The data required to generate the needed information are often disseminated in archives of oil companies and African geologic surveys, or in obscure publications. For these reasons, the U.S. Geological Survey is collecting data on sub-Saharan energy and constructing a regional energy bibliography. The team of geoscientists will assure that this information is available quickly and from a scientifically based, objective view point.

Selective export of autotaxin from the endoplasmic reticulum.

PubMed

Lyu, Lin; Wang, Baolu; Xiong, Chaoyang; Zhang, Xiaotian; Zhang, Xiaoyan; Zhang, Junjie

2017-04-28

Autotaxin (ATX) or ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2) is a secretory glycoprotein and functions as the key enzyme for lysophosphatidic acid generation. The mechanism of ATX protein trafficking is largely unknown. Here, we demonstrated that p23, a member of the p24 protein family, was the protein-sorting receptor required for endoplasmic reticulum (ER) export of ATX. A di-phenylalanine (Phe-838/Phe-839) motif in the human ATX C-terminal region was identified as a transport signal essential for the ATX-p23 interaction. Knockdown of individual Sec24 isoforms by siRNA revealed that ER export of ATX was impaired only if Sec24C was down-regulated. These results suggest that ATX is selectively exported from the ER through a p23, Sec24C-dependent pathway. In addition, it was found that AKT signaling played a role in ATX secretion regulation to facilitate ATX ER export by enhancing the nuclear factor of activated T cell-mediated p23 expression. Furthermore, the di-hydrophobic amino acid motifs (FY) also existed in the C-terminal regions of human ENPP1 and ENPP3. Such a p23, Sec24C-dependent selective ER export mechanism is conserved among these ENPP family members. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Mercury exports from a High-Arctic river basin in Northeast Greenland (74°N) largely controlled by glacial lake outburst floods.

PubMed

Søndergaard, Jens; Tamstorf, Mikkel; Elberling, Bo; Larsen, Martin M; Mylius, Maria Rask; Lund, Magnus; Abermann, Jakob; Rigét, Frank

2015-05-01

Riverine mercury (Hg) export dynamics from the Zackenberg River Basin (ZRB) in Northeast Greenland were studied for the period 2009-2013. Dissolved and sediment-bound Hg was measured regularly in the Zackenberg River throughout the periods with running water (June-October) and coupled to water discharge measurements. Also, a few samples of snow, soil, and permafrost were analysed for Hg. Mean concentrations of dissolved and sediment-bound Hg in the river water (±SD) were 0.39 ± 0.13 and 5.5 ± 1.4 ngL(-1), respectively, and mean concentrations of Hg in the river sediment were 0.033 ± 0.025 mg kg(-1). Temporal variations in river Hg were mainly associated with snowmelt, sudden erosion events, and outburst floods from a glacier-dammed lake in the upper part of the ZRB. Annual Hg exports from the 514 km(2) ZRB varied from 0.71 to >1.57 kg and the majority (86-96%) was associated with sediment-bound Hg. Hg yields from the ZRB varied from 1.4-3.1 gH gk m(-2)yr(-1) and were among the highest yields reported from Arctic river basins. River exports of Hg from ZRB were found to be largely controlled by the frequency, magnitude and timing of the glacial lake outburst floods, which occurred in four of the five years in July-August. Floods accounted for 5 to >10% of the annual water discharge, and up to >31% of the annual Hg export. Also, the winter snowfall and the summer temperatures were found to be important indirect controls on the annual Hg export. The occurrence and timing of glacial lake outburst floods in the ZRB in late summer at the time of maximum soil thaw depth, the location of the glacier in the upper ZRB, and increased thawing of the permafrost in Zackenberg in recent years leading to destabilisation of river banks are considered central factors explaining the high fraction of flood-controlled Hg export in this area. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of sediment and nutrient export and runoff characteristics from watersheds with centralized versus distributed stormwater management.

PubMed

Hopkins, Kristina G; Loperfido, J V; Craig, Laura S; Noe, Gregory B; Hogan, Dianna M

2017-12-01

Stormwater control measures (SCMs) are used to retain stormwater and pollutants. SCMs have traditionally been installed in a centralized manner using detention to mitigate peak flows. Recently, distributed SCM networks that treat runoff near the source have been increasingly utilized. The aim of this study was to evaluate differences among watersheds that vary in SCM arrangement by assessing differences in baseflow nutrient (NO x -N and PO 4 - ) concentrations and fluxes, stormflow export of suspended sediments and particulate phosphorus (PP), and runoff characteristics. A paired watershed approach was used to compare export between 2004 and 2016 from one forested watershed (For-MD), one suburban watershed with centralized SCMs (Cent-MD), and one suburban watershed with distributed SCMs (Dist-MD). Results indicated baseflow nitrate (NO x -N) concentrations typically exceeded 1 mg-N/L in all watersheds and were highest in Dist-MD. Over the last 10 years in Dist-MD, nitrate concentrations in both stream baseflow and in a groundwater well declined as land use shifted from agriculture to suburban. Baseflow nitrate export temporarily increased during the construction phase of SCM development in Dist-MD. This temporary pulse of nitrate may be attributed to the conversion of sediment control facilities to SCMs and increased subsurface flushing as infiltration SCMs came on line. During storm flow, Dist-MD tended to have less runoff and lower maximum specific discharge than Cent-MD for small events (<1.3 cm), but runoff responses became increasingly similar to Cent-MD with increasing precipitation (>1.3 cm). Mass export estimated during paired storm events indicated Dist-MD exported 30% less sediment and 31% more PP than Cent-MD. For large precipitation events, export of sediment and PP was similar among all three watersheds. Results suggest that distributed SCMs can reduce runoff and sediment loads during small rain events compared to centralized SCMs, but these differences become less evident for large events when peak discharge likely leads to substantial bank erosion. Published by Elsevier Ltd.

International Agricultural Trade and Policy: Issues and Implications for U.S. Agriculture. Texas Agricultural Market Research Center Special Series Report No. SS-2-89.

ERIC Educational Resources Information Center

Williams, Gary W.

Historical events have set the stage for the current U.S. agricultural export performance. Agricultural exports in the early 1990s were as large or larger relative to the size of the agricultural sector than at any time since. A dramatic decrease in net farm income was caused by the Great Depression (1929-1932). Following passage of the…

Water footprint of Jing-Jin-Ji urban agglomeration in China

NASA Astrophysics Data System (ADS)

Zhao, D.

2017-12-01

A rapidly expanding economy and increasing water demand for economic production is placing enormous stress on water quantity and aquatic environment in Northern China, especially the so-called Jing-Jin-Ji (Beijing-Tianjin-Hebei) urban agglomeration. Several studies have focused on energy consumption, air pollution, CO2 emissions and regional blue water footprint (WF) following release of the Jing-Jin-Ji Integration Strategy by the China government. However, a comprehensive assessment distinguishing blue, green and grey WF amongst different industrial sectors, ascertaining how WF transfers internally and beyond the region and final demand consumption is not available. In this study, we quantified the WF and virtual water flow on a sectoral basis for the year 2010 through coupling the multi-regional input-output model (MRIO) with WF assessment. The results showed that Beijing and Tianjin are net importers of green, blue and grey water from Hebei and other provinces to support their needs. Conversely, Hebei exports all WF colors to Beijing, Tianjin and other provinces in China, more than 60% of WF is transferred as virtual water. For the overall Jing-Jin-Ji region a small amount of blue water (2,086 million m3) is exported, but huge amounts of green water (15,573 million m3) and grey water (30,620 million m3) are outsourced. A "Virtual Water Strategy" is one measure which could alleviate water stress at the regional scale, with consideration of financial compensation from water receiving regions made to water supplying regions for achieving water management targets. We also found that physical water transfer to Jing-Jin-Ji could not balance virtual blue water exports. Our research suggests that a continuation of an export-based economic development model will worsen Hebei's water stress. Reducing the dependency of Hebei's sectoral economy on export of water intensive and low value added agricultural products may be one strategy to reduce the pressure on regional water resources. In addition, the Integration Strategy drives industrial transfer from Beijing to Hebei resulting in the transfer of enterprises with low water utilization efficiency and producing heavy pollution. Thus, the government should consider incentivizing corporations to adopt technologies that reduce water consumption and pollution.

A biochemical framework for eIF4E-dependent mRNA export and nuclear recycling of the export machinery.

PubMed

Volpon, Laurent; Culjkovic-Kraljacic, Biljana; Sohn, Hye Seon; Blanchet-Cohen, Alexis; Osborne, Michael J; Borden, Katherine L B

2017-06-01

The eukaryotic translation initiation factor eIF4E acts in the nuclear export and translation of a subset of mRNAs. Both of these functions contribute to its oncogenic potential. While the biochemical mechanisms that underlie translation are relatively well understood, the molecular basis for eIF4E's role in mRNA export remains largely unexplored. To date, over 3000 transcripts, many encoding oncoproteins, were identified as potential nuclear eIF4E export targets. These target RNAs typically contain a ∼50-nucleotide eIF4E sensitivity element (4ESE) in the 3' UTR and a 7-methylguanosine cap on the 5' end. While eIF4E associates with the cap, an unknown factor recognizes the 4ESE element. We previously identified cofactors that functionally interacted with eIF4E in mammalian cell nuclei including the leucine-rich pentatricopeptide repeat protein LRPPRC and the export receptor CRM1/XPO1. LRPPRC simultaneously interacts with both eIF4E bound to the 5' mRNA cap and the 4ESE element in the 3' UTR. In this way, LRPPRC serves as a specificity factor to recruit 4ESE-containing RNAs within the nucleus. Further, we show that CRM1 directly binds LRPPRC likely acting as the export receptor for the LRPPRC-eIF4E-4ESE RNA complex. We also found that Importin 8, the nuclear importer for cap-free eIF4E, imports RNA-free LRPPRC, potentially providing both coordinated nuclear recycling of the export machinery and an important surveillance mechanism to prevent futile export cycles. Our studies provide the first biochemical framework for the eIF4E-dependent mRNA export pathway. © 2017 Volpon et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

mRNA quality control is bypassed for immediate export of stress-responsive transcripts.

PubMed

Zander, Gesa; Hackmann, Alexandra; Bender, Lysann; Becker, Daniel; Lingner, Thomas; Salinas, Gabriela; Krebber, Heike

2016-12-12

Cells grow well only in a narrow range of physiological conditions. Surviving extreme conditions requires the instantaneous expression of chaperones that help to overcome stressful situations. To ensure the preferential synthesis of these heat-shock proteins, cells inhibit transcription, pre-mRNA processing and nuclear export of non-heat-shock transcripts, while stress-specific mRNAs are exclusively exported and translated. How cells manage the selective retention of regular transcripts and the simultaneous rapid export of heat-shock mRNAs is largely unknown. In Saccharomyces cerevisiae, the shuttling RNA adaptor proteins Npl3, Gbp2, Hrb1 and Nab2 are loaded co-transcriptionally onto growing pre-mRNAs. For nuclear export, they recruit the export-receptor heterodimer Mex67-Mtr2 (TAP-p15 in humans). Here we show that cellular stress induces the dissociation of Mex67 and its adaptor proteins from regular mRNAs to prevent general mRNA export. At the same time, heat-shock mRNAs are rapidly exported in association with Mex67, without the need for adapters. The immediate co-transcriptional loading of Mex67 onto heat-shock mRNAs involves Hsf1, a heat-shock transcription factor that binds to heat-shock-promoter elements in stress-responsive genes. An important difference between the export modes is that adaptor-protein-bound mRNAs undergo quality control, whereas stress-specific transcripts do not. In fact, regular mRNAs are converted into uncontrolled stress-responsive transcripts if expressed under the control of a heat-shock promoter, suggesting that whether an mRNA undergoes quality control is encrypted therein. Under normal conditions, Mex67 adaptor proteins are recruited for RNA surveillance, with only quality-controlled mRNAs allowed to associate with Mex67 and leave the nucleus. Thus, at the cost of error-free mRNA formation, heat-shock mRNAs are exported and translated without delay, allowing cells to survive extreme situations.

Seasonal changes in particulate and dissolved organic matter composition and quality in the Lena River Delta

NASA Astrophysics Data System (ADS)

Mollenhauer, G.; Winterfeld, M.; Hefter, J.; Bodenstab, L.; Morgenstern, A.; Eulenburg, A.; Heim, B.; Koch, B.; Schefuss, E.; Moerth, C. M.; Rethemeyer, J.

2016-12-01

Arctic rivers are known to export large quantities of carbon by discharge of dissolved and particulate organic carbon (DOC, POC), and in a warming and progressively moister Arctic, these exports may increase resulting in a reduction of arctic continental carbon stocks. These rivers have highly variable discharge rates with a pronounced maximum during the spring freshet associated with highest concentrations of DOC and POC. Most studies investigating the isotopic composition and quality of carbon exported by Arctic rivers rely on samples taken in summer during base flow, which is due to the logistical challenges associated with sampling in the remote Arctic permafrost regions. Here we present a record of δ13C and Δ14C of DOC and POC collected between late May during the freshet and late August 2014 in the Lena River Delta. POC Δ14C shows an initial trend towards older values in the spring samples, which is reversed in summer, associated with a shift towards more depleted δ13C values. We interpret this aging trend as reflecting progressive thawing throughout the ice-free season, resulting in mobilization of progressively older carbon from deeper thawed layers. The summer reversal indicates admixture of aquatic organic matter. DOC Δ14C, in contrast, remains at relatively modern levels with rather constant δ13C values throughout the sampling period. We furthermore analysed the biomarker composition of Lena Delta particulate OM collected in spring and summer. From spring to summer, we observe trends in abundance of individual leaf-wax derived biomarkers indicating higher abundance of algal biomass in the summer particles. Trends in soil microbial biomarkers and compound-specific δD of leaf-wax lipids suggest a shift in sources towards higher contributions from the southern catchment in summer. DOC composition investigated with FT-ICR-MS changes from spring with higher abundances of compounds with high H/C and low O/C ratios to late summer, when fewer compounds were found. Our results illustrate the seasonal variability in composition and sources of organic matter discharged by the Lena River. Paired with the strong seassonality of the hydrograph, this implies that total annual discharge of organic matter contains a disproportionally high contribution from the northern part of the catchment.

Rising trade, declining stocks: The global gugul (Commiphora wightii) trade.

PubMed

Cunningham, A B; Brinckmann, J A; Kulloli, R N; Schippmann, U

2018-09-15

Commiphora wightii is exploited in India and Pakistan for an oleo-resin (gum guggul) traditionally used in Ayurvedic, Siddha and Unani medical systems. Processed C. wightii oleo-resin products are exported from India to 42 countries, including re-export to Pakistan, for anti-inflammatory use and as an anti-inflammatory and an anti-obesity treatment considered to lower cholesterol and lipid levels. The C. wightii export trade has particular relevance to the European Union because Belgium, France, Germany, Hungary, Italy, the Netherlands, and United Kingdom are importing countries. Demand and prices for C. wightii oleo-resin are increasing and wild stocks of C. wightii are in decline. The overexploitation of C. wightii after tapping for its commercially valuable oleo-resin is not a new problem, however, but one that has existed for over 50 years. Lopping and chopping trees to extract C. wightii oleo-resin has had a devastating impact on C. wightii populations since the 1960's. The aim of this study was to review the sustainability of the global trade in C. wightii oleo-resin. This included reviewing studies on resin tapping methods and the impacts of wild harvest on C. wightii populations in India and Pakistan. Firstly, we reviewed studies on impacts of C. wightii oleo-resin harvest and on the policy responses taken in relation to harvest and trade in C. wightii oleo-resin. Secondly, we reviewed studies on C. wightii cultivation. Thirdly, global trade data for C. wightii were analyzed. Destructive harvest to obtain the gum is the major threat facing this species. C. wightii populations are also fragmented by habitat loss through clearing for farming. Cutting and lopping in order to extract the medicinal gum are a major threat to C. wightii populations, as is poor recruitment due to grazing by livestock. As a result of over-exploitation, C. wightii oleo-resin production has declined in India. In Gujarat, a key production area, the decline over a 50-year period has been from 30 t in 1963, to 2.42 t in 1999 to 1.6 t in 2013. Consequently, large quantities of C. wightii oleo-resin (around 505 t/year) are imported into India from Pakistan. An estimated 193 t/year of crude gum equivalent is exported from India in the form of processed products. With remaining populations in decline due to commercial exploitation for international trade, a range of policy options (such as CITES Appendix II listing) and practical conservation actions (such as cultivation) need to be considered. Copyright © 2018 Elsevier B.V. All rights reserved.

Export of pre-aged, labile DOM from a central California coastal upwelling system: Insights from D/L amino acids and Δ14C signatures

NASA Astrophysics Data System (ADS)

Walker, B. D.; Shen, Y.; Benner, R. H.; Druffel, E. R. M.

2014-12-01

Coastal upwelling zones are among the most productive regions in the world and play a major role in global carbon and nitrogen cycles. Recent research suggests that a substantial fraction of newly fixed organic matter is exported offshore in the form of dissolved organic matter (DOM). However, to date only a few studies have examined DOM composition in the context of production and export from upwelling systems. The ultimate fate and geochemical impact of coastal DOM exported to offshore and mesopelagic ecosystems also remains largely unknown. Between 2007-2009 we conducted a high-resolution biogeochemical time series at the Granite Canyon Marine Pollution Studies Lab in part to evaluate the seasonal production and export of DOM from the Central CA coast. Our previous work demonstrated substantial, albeit disparate, seasonal production of dissolved organic carbon and nitrogen (DOC, DON) - with high DON (and low C:N ratios) produced during upwelling and high DOC produced during summer/fall water column stratification (Walker and McCarthy, 2012). Here we present new total dissolved D/L amino acid (TDAA) and UV-oxidizable DOC radiocarbon (Δ14C) data with the goal of determining the relative sources (heterotrophic vs. autotrophic), bioavailability, microbial processing and 14C-ages of C-rich vs. N-rich DOM exported from this upwelling system. Our results suggest that C-rich DOM produced during water column stratification carries a large microbial signature (i.e. high D/L AA ratios and non-protein AA abundance), whereas N-rich DOM produced during upwelling appears to be fresh, autotrophic DOM (i.e. lowest D/L AA ratios and highest TDAA abundance). DOM Δ14C signatures also did not approximate in situ dissolved inorganic carbon (DIC), and instead were far more negative and highly correlated to water mass density. Together our results indicate a previously unrecognized source of highly labile yet pre-aged DOM potentially impacting offshore and mesopelagic ecosystems.

The exported chaperone Hsp70-x supports virulence functions for Plasmodium falciparum blood stage parasites

PubMed Central

Charnaud, Sarah C.; Dixon, Matthew W. A.; Nie, Catherine Q.; Chappell, Lia; Sanders, Paul R.; Nebl, Thomas; Hanssen, Eric; Berriman, Matthew; Chan, Jo-Anne; Blanch, Adam J.; Beeson, James G.; Rayner, Julian C.; Przyborski, Jude M.; Tilley, Leann; Crabb, Brendan S.

2017-01-01

Malaria is caused by five different Plasmodium spp. in humans each of which modifies the host erythrocyte to survive and replicate. The two main causes of malaria, P. falciparum and P. vivax, differ in their ability to cause severe disease, mainly due to differences in the cytoadhesion of infected erythrocytes (IE) in the microvasculature. Cytoadhesion of P. falciparum in the brain leads to a large number of deaths each year and is a consequence of exported parasite proteins, some of which modify the erythrocyte cytoskeleton while others such as PfEMP1 project onto the erythrocyte surface where they bind to endothelial cells. Here we investigate the effects of knocking out an exported Hsp70-type chaperone termed Hsp70-x that is present in P. falciparum but not P. vivax. Although the growth of Δhsp70-x parasites was unaffected, the export of PfEMP1 cytoadherence proteins was delayed and Δhsp70-x IE had reduced adhesion. The Δhsp70-x IE were also more rigid than wild-type controls indicating changes in the way the parasites modified their host erythrocyte. To investigate the cause of this, transcriptional and translational changes in exported and chaperone proteins were monitored and some changes were observed. We propose that PfHsp70-x is not essential for survival in vitro, but may be required for the efficient export and functioning of some P. falciparum exported proteins. PMID:28732045

Giant landslide deposits and the modalities of their removal by fluvial sediment export in the central Himalayas

NASA Astrophysics Data System (ADS)

Lave, Jerome; Lénard, Sébastien; Lanord, Christian France

2017-04-01

Slope failures and deep seated landslides are usually considered as the most efficient processes for hillslope erosion in active orogens. Erosion in the Narayani basin in central Himalaya (Nepal) confirms such assertion, with in addition the probable predominance of the very large landslides in the erosive budget of the range. In the High Himalayan part of this basin, a number of pluri-kilometric giant landslides have been described and involve up to ten cubic kilometres mass wasting (e.g. Weidinger et al., 2002). In this contribution, we discuss how the fluvial network do respond to such massive and sudden supply of debris, basing our analysis on several cases, documented by sedimentologic and geomorphologic observations, lithologic counting, geochemical tracing (down to the Ganga plain), and 14C or CRN dating. We first demonstrate that several massive fill terraces preserved along the Lesser Himalayan intramontane reaches are not climatically induced, but rather represent transient storage following giant landslide material export. Two types of deposits and therefore of sediment export modalities have been identified: either (1), as observed along a 100km long stretch of the Marsyandi river, through massive debris flow(s) runout following the break of a landslide-induced dam on main rivers, or (2) by the more gradual but efficient fluvial removal of the giant landslide deposits. In the second case, in particular when bedrock fracturing and crushing during landslide fall has strongly reduced the average debris size, because the steep Himalayan rivers are usually in strong over capacity or largely underloaded with fine to medium-size sediment, their can carry up to several cubic kilometres of sediments in one or two centuries. The coarsest part of the exported material is temporarily stored through aggradation in the massive Lesser Himalayan fill terraces because river gradient drops suddenly when river exits the High Himalaya, whereas the finest fraction is exported very rapidly further downstream, outside of the range. Once a large portion of the landslide debris has been eroded in the source deposit, river quickly returns to over-capacity conditions and to its long term or background conditions, and fill terraces are rapidly re-incised (re-erosion of the fill terrace occurs at rates incommensurate with long term bedrock downcutting rate). The documented Himalayan examples illustrate that erosion of giant landslides deposits can overwhelm the sediment export of a river as large as the Narayani (A=30000km2; average sediment export=150Mt/yr) during several centuries, but that the landscape quickly (i.e. in a similar amount of time) recovers and returns to some long-term average state. The long term influence of these events on the morphology of the fluvial network remains therefore moderate, if we except the persistence of fill terraces remnants in the Lesser Himalaya for several tens of kyr.

40 CFR 273.37 - Response to releases.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 273.37 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.37... of universal wastes and other residues from universal wastes. (b) A large quantity handler of...

40 CFR 273.38 - Off-site shipments.

Code of Federal Regulations, 2012 CFR

2012-07-01

....38 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.38 Off-site shipments. (a) A large quantity handler of universal waste is prohibited from sending or...

40 CFR 273.38 - Off-site shipments.

Code of Federal Regulations, 2011 CFR

2011-07-01

....38 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.38 Off-site shipments. (a) A large quantity handler of universal waste is prohibited from sending or...

40 CFR 273.38 - Off-site shipments.

Code of Federal Regulations, 2010 CFR

2010-07-01

....38 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.38 Off-site shipments. (a) A large quantity handler of universal waste is prohibited from sending or...

40 CFR 273.38 - Off-site shipments.

Code of Federal Regulations, 2014 CFR

2014-07-01

....38 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.38 Off-site shipments. (a) A large quantity handler of universal waste is prohibited from sending or...

40 CFR 273.38 - Off-site shipments.

Code of Federal Regulations, 2013 CFR

2013-07-01

....38 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.38 Off-site shipments. (a) A large quantity handler of universal waste is prohibited from sending or...

The United States and the Asia-Pacific Region: Security Strategy for the Obama Administration

DTIC Science & Technology

2009-02-01

increasing interest in multilateral cooperation. Once a laggard, the region now hosts a veritable “ noodle bowl” of multilateral political, economic, and...global exports. Asian manufacturers have captured a large share of global production chains. Asian governments and government- controlled institutions...from U.S. Census Bureau data Seven of the top 15 U.S. manufactured export destinations are in Asia • China • Japan • South Korea • Taiwan Eight

JPRS Report, Soviet Union, Kommunist, No. 2, January 1989

DTIC Science & Technology

1989-04-20

the entire increase in the production of refrig- erators was for export . However, in the case of a large number of goods deliveries to the trade...productivity would more than compensate for losses to the budget. A lowering of expenditures which had been financed out of income from the sale of wine ...implement the assignments of the 5-year plan, increased substan- tially. Combined with the further decline in exports , this resulted in a worsening

Using Coupled Models to Study the Effects of River Discharge on Biogeochemical Cycling and Hypoxia in the Northern Gulf of Mexico

NASA Technical Reports Server (NTRS)

Penta, Bradley; Ko, D.; Gould, Richard W.; Arnone, Robert A.; Greene, R.; Lehrter, J.; Hagy, James; Schaeffer, B.; Murrell, M.; Kurtz, J.;

Effects of different N sources on riverine DIN export and retention in a subtropical high-standing island, Taiwan

PubMed Central

Huang, Jr-Chuan; Lee, Tsung-Yu; Lin, Teng-Chiu; Hein, Thomas; Lee, Li-Chin; Shih, Yu-Ting; Kao, Shuh-Ji; Shiah, Fuh-Kwo; Lin, Neng-Huei

2016-01-01

Increases in nitrogen (N) availability and mobility resulting from anthropogenic activities have substantially altered the N cycle, both locally and globally. Taiwan characterized by the subtropical montane landscape with abundant rainfall, downwind of the most rapidly industrializing eastern coast of China, can be a demonstration site for extremely high N input and riverine DIN (dissolved inorganic N) export. We used 49 watersheds with similar climatic and landscape settings but classified into low, moderate, and highly disturbed categories based on population density to illustrate their differences in nitrogen inputs (through atmospheric N deposition, synthetic fertilizers, and human emission) and DIN export ratios. Our results showed that the island-wide average riverine DIN export is ~ 3800 kg N km−2 yr−1, approximately 18 times the global average. The average riverine DIN export ratios are 0.30−0.51, which are much higher than the averages of 0.20−0.25 of large rivers around the world, indicating excessive N input relative to ecosystem demand or retention capacity. The low disturbed watersheds have a high N retention capacity and DIN export ratios of 0.06−0.18 in spite of the high N input (~ 4900 kg N km−2 yr−1). The high retention capacity is likely due to effective uptake by secondary forests in the watersheds. The moderately disturbed watersheds show a linear increase in DIN export with increases in total N inputs and mean DIN export ratios of 0.20 to 0.31. The main difference in land use between low and moderately disturbed watersheds is the greater proportion of agricultural land cover in the moderately disturbed watersheds. Thus, their greater DIN export could be attributed to N fertilizers used in the agricultural lands. The greater export ratios also imply that agricultural lands have a lower proportional N retention capacity and that reforestation could be an effective land management practice to reduce riverine DIN export. The export ratios of the highly disturbed watersheds are very high, 0.42–0.53, suggesting that much of the N input is transported downstream directly, and urges the need to increase the proportion of households connected to a sewage system and improve the effectiveness of wastewater treatment systems. The increases in the riverine DIN export ratio along the gradient of human disturbance also suggest a gradient in N saturation in subtropical Taiwan. Our results help to improve our understanding of factors controlling riverine DIN export and provide empirical evidence that calls for sound N emission/pollution control measures. PMID:27212969

Effects of different N sources on riverine DIN export and retention in a subtropical high-standing island, Taiwan.

PubMed

Huang, Jr-Chuan; Lee, Tsung-Yu; Lin, Teng-Chiu; Hein, Thomas; Lee, Li-Chin; Shih, Yu-Ting; Kao, Shuh-Ji; Shiah, Fuh-Kwo; Lin, Neng-Huei

Increases in nitrogen (N) availability and mobility resulting from anthropogenic activities have substantially altered the N cycle, both locally and globally. Taiwan characterized by the subtropical montane landscape with abundant rainfall, downwind of the most rapidly industrializing eastern coast of China, can be a demonstration site for extremely high N input and riverine DIN (dissolved inorganic N) export. We used 49 watersheds with similar climatic and landscape settings but classified into low, moderate, and highly disturbed categories based on population density to illustrate their differences in nitrogen inputs (through atmospheric N deposition, synthetic fertilizers, and human emission) and DIN export ratios. Our results showed that the island-wide average riverine DIN export is ~ 3800 kg N km -2 yr -1 , approximately 18 times the global average. The average riverine DIN export ratios are 0.30-0.51, which are much higher than the averages of 0.20-0.25 of large rivers around the world, indicating excessive N input relative to ecosystem demand or retention capacity. The low disturbed watersheds have a high N retention capacity and DIN export ratios of 0.06-0.18 in spite of the high N input (~ 4900 kg N km -2 yr -1 ). The high retention capacity is likely due to effective uptake by secondary forests in the watersheds. The moderately disturbed watersheds show a linear increase in DIN export with increases in total N inputs and mean DIN export ratios of 0.20 to 0.31. The main difference in land use between low and moderately disturbed watersheds is the greater proportion of agricultural land cover in the moderately disturbed watersheds. Thus, their greater DIN export could be attributed to N fertilizers used in the agricultural lands. The greater export ratios also imply that agricultural lands have a lower proportional N retention capacity and that reforestation could be an effective land management practice to reduce riverine DIN export. The export ratios of the highly disturbed watersheds are very high, 0.42-0.53, suggesting that much of the N input is transported downstream directly, and urges the need to increase the proportion of households connected to a sewage system and improve the effectiveness of wastewater treatment systems. The increases in the riverine DIN export ratio along the gradient of human disturbance also suggest a gradient in N saturation in subtropical Taiwan. Our results help to improve our understanding of factors controlling riverine DIN export and provide empirical evidence that calls for sound N emission/pollution control measures.

Effects of different N sources on riverine DIN export and retention in a subtropical high-standing island, Taiwan

NASA Astrophysics Data System (ADS)

Huang-Chuan, Jr.; Lee, Tsung-Yu; Lin, Teng-Chiu; Hein, Thomas; Lee, Li-Chin; Shih, Yu-Ting; Kao, Shuh-Ji; Shiah, Fuh-Kwo; Lin, Neng-Huei

2016-03-01

Increases in nitrogen (N) availability and mobility resulting from anthropogenic activities have substantially altered the N cycle, both locally and globally. Taiwan characterized by the subtropical montane landscape with abundant rainfall, downwind of the most rapidly industrializing eastern coast of China, can be a demonstration site for extremely high N input and riverine DIN (dissolved inorganic N) export. We used 49 watersheds with similar climatic and landscape settings but classified into low, moderate, and highly disturbed categories based on population density to illustrate their differences in nitrogen inputs (through atmospheric N deposition, synthetic fertilizers, and human emission) and DIN export ratios. Our results showed that the island-wide average riverine DIN export is ˜ 3800 kg N km-2 yr-1, approximately 18 times the global average. The average riverine DIN export ratios are 0.30-0.51, which are much higher than the averages of 0.20-0.25 of large rivers around the world, indicating excessive N input relative to ecosystem demand or retention capacity. The low disturbed watersheds have a high N retention capacity and DIN export ratios of 0.06-0.18 in spite of the high N input (˜ 4900 kg N km-2 yr-1). The high retention capacity is likely due to effective uptake by secondary forests in the watersheds. The moderately disturbed watersheds show a linear increase in DIN export with increases in total N inputs and mean DIN export ratios of 0.20 to 0.31. The main difference in land use between low and moderately disturbed watersheds is the greater proportion of agricultural land cover in the moderately disturbed watersheds. Thus, their greater DIN export could be attributed to N fertilizers used in the agricultural lands. The greater export ratios also imply that agricultural lands have a lower proportional N retention capacity and that reforestation could be an effective land management practice to reduce riverine DIN export. The export ratios of the highly disturbed watersheds are very high, 0.42-0.53, suggesting that much of the N input is transported downstream directly, and urges the need to increase the proportion of households connected to a sewage system and improve the effectiveness of wastewater treatment systems. The increases in the riverine DIN export ratio along the gradient of human disturbance also suggest a gradient in N saturation in subtropical Taiwan. Our results help to improve our understanding of factors controlling riverine DIN export and provide empirical evidence that calls for sound N emission/pollution control measures.

The export and fate of organic matter in the ocean: New constraints from combining satellite and oceanographic tracer observations

NASA Astrophysics Data System (ADS)

DeVries, Tim; Weber, Thomas

2017-03-01

The ocean's biological pump transfers carbon from the surface euphotic zone into the deep ocean, reducing the atmospheric CO2 concentration. Despite its climatic importance, there are large uncertainties in basic metrics of the biological pump. Previous estimates of the strength of the biological pump, as measured by the amount of organic carbon exported from the euphotic zone, range from about 4 to 12 Pg C yr-1. The fate of exported carbon, in terms of how efficiently it is transferred into the deep ocean, is even more uncertain. Here we present a new model of the biological pump that assimilates satellite and oceanographic tracer observations to constrain rates and patterns of organic matter production, export, and remineralization in the ocean. The data-assimilated model predicts a global particulate organic carbon (POC) flux out of the euphotic zone of ˜9 Pg C yr-1. The particle export ratio (the ratio of POC export to net primary production) is highest at high latitudes and lowest at low latitudes, but low-latitude export is greater than predicted by previous models, in better agreement with observed patterns of long-term carbon export. Particle transfer efficiency (Teff) through the mesopelagic zone is controlled by temperature and oxygen, with highest Teff for high-latitude regions and oxygen minimum zones. In contrast, Teff in the deep ocean (below 1000 m) is controlled by particle sinking speed, with highest deep ocean Teff below the subtropical gyres. These results emphasize the utility of both remote sensing and oceanographic tracer observations for constraining the operation of the biological pump.

75 FR 38989 - Welded Large Diameter Line Pipe From Japan: Notice of Rescission of Antidumping Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-07

... Pipe From Japan: Notice of Rescission of Antidumping Duty Administrative Review AGENCY: Import... antidumping duty order on welded large diameter line pipe from Japan. The review covers 4 producers/exporters of welded large diameter line pipe from Japan, which are, JFE Steel Corporation, Nippon Steel...

China's international trade and air pollution: 2000 - 2009

NASA Astrophysics Data System (ADS)

Ni, Ruijing; Lin, Jintai; Pan, Da; Wang, Jingxu; Yan, Yingying; Zhang, Qiang

2016-04-01

As the world's top trading country, China is now the most polluted country. However, a large portion of pollution produced in China is associated with its production of goods for foreign consumption via international trade. Along with China's rapid economic growth in recent years, its economic-trade structure and volume has been changing all the time, resulting in large changes in total emissions and the shares of trade-related emissions. Here, we assess the influence of China's changing total and export-related emissions between 2000 and 2009 on its atmospheric pollution loadings and transport, by exploiting simulations of a global chemical transport model GEOS-Chem. We find that both air pollution related to Chinese exports (PRE) which including nitrogen oxides (NOx), sulfur dioxide (SO2), carbon monoxide (CO), black carbon (BC), and primary organic aerosol (POA), and its share in total Chinese pollution have experienced continuous rapid growth until 2007, exposing more and more people to severely polluted air. After 2007, PRE decreases due to strengthened emission controls accompanied by declined exports as a result of the global financial crisis. Although production for exports contribute less than 35% SO2 over China in any year, the increasing trend of trade-related SO2 contributes 51% of integral trend. The changing PRE of China also affects its downwind regions such as the western United States. The contribution of export-related Chinese pollution to surface sulfate concentrations over the western United States has increased from 3% in 2000 to 12% in 2007. Overall, we find that the interannual variation of trade and associated production is a critical factor driving the trend of pollution over China and its downwind regions.

Greenland Ice Sheet exports labile organic carbon to the Arctic oceans

NASA Astrophysics Data System (ADS)

Lawson, E. C.; Wadham, J. L.; Tranter, M.; Stibal, M.; Lis, G. P.; Butler, C. E. H.; Laybourn-Parry, J.; Nienow, P.; Chandler, D.; Dewsbury, P.

2014-07-01

Runoff from small glacier systems contains dissolved organic carbon (DOC) rich in protein-like, low molecular weight (LMW) compounds, designating glaciers as an important source of bioavailable carbon for downstream heterotrophic activity. Fluxes of DOC and particulate organic carbon (POC) exported from large Greenland catchments, however, remain unquantified, despite the Greenland Ice Sheet (GrIS) being the largest source of global glacial runoff (ca. 400 km3 yr-1). We report high and episodic fluxes of POC and DOC from a large (>600 km2) GrIS catchment during contrasting melt seasons. POC dominates organic carbon (OC) export (70-89% on average), is sourced from the ice sheet bed, and contains a significant bioreactive component (9% carbohydrates). A major source of the "bioavailable" (free carbohydrate) LMW-DOC fraction is microbial activity on the ice sheet surface, with some further addition of LMW-DOC to meltwaters by biogeochemical processes at the ice sheet bed. The bioavailability of the exported DOC (26-53%) to downstream marine microorganisms is similar to that reported from other glacial watersheds. Annual fluxes of DOC and free carbohydrates during two melt seasons were similar, despite the approximately two-fold difference in runoff fluxes, suggesting production-limited DOC sources. POC fluxes were also insensitive to an increase in seasonal runoff volumes, indicating a supply limitation in suspended sediment in runoff. Scaled to the GrIS, the combined DOC (0.13-0.17 Tg C yr-1 (±13%)) and POC fluxes (mean = 0.36-1.52 Tg C yr-1 (±14%)) are of a similar order of magnitude to a large Arctic river system, and hence may represent an important OC source to the near-coastal North Atlantic, Greenland and Labrador seas.

Greenland Ice Sheet exports labile organic carbon to the Arctic oceans

NASA Astrophysics Data System (ADS)

Lawson, E. C.; Wadham, J. L.; Tranter, M.; Stibal, M.; Lis, G. P.; Butler, C. E. H.; Laybourn-Parry, J.; Nienow, P.; Chandler, D.; Dewsbury, P.

2013-12-01

Runoff from small glacier systems contains dissolved organic carbon (DOC), rich in protein-like, low molecular weight (LMW) compounds, designating glaciers as an important source of bioavailable carbon for downstream heterotrophic activity. Fluxes of DOC and particulate organic carbon (POC) exported from large Greenland catchments, however, remain unquantified, despite the Greenland Ice Sheet (GrIS) being the largest source of global glacial runoff (ca. 400 km3 yr-1). We report high and episodic fluxes of POC and DOC from a large (1200 km2) GrIS catchment during contrasting melt seasons. POC dominates organic carbon (OC) export (70-89% on average), is sourced from the ice sheet bed and contains a significant bioreactive component (9% carbohydrates). A major source for the "bioavailable" (free carbohydrates) LMW-DOC fraction is microbial activity on the ice sheet surface, with some further addition of LMW-DOC to meltwaters by biogeochemical processes at the ice sheet bed. The bioavailability of the exported DOC (30-58%) to downstream marine microorganisms is similar to that reported from other glacial watersheds. Annual fluxes of DOC and free carbohydrates during two melt seasons were similar, despite the ~ 2 fold difference in runoff fluxes, suggesting production-limited DOC sources. POC fluxes were also insensitive to an increase in seasonal runoff volumes, indicating supply-limitation of suspended sediment in runoff. Scaled to the GrIS, the combined DOC and POC fluxes (0.13-0.17 Tg C yr-1 DOC, 0.36-1.52 Tg C yr-1 mean POC) are of a similar order of magnitude to a large Arctic river system, and hence represent an important OC source to the North Atlantic, Greenland and Labrador Seas.

Biodegradability of dissolved organic carbon in the Yukon River and its tributaries: Seasonality and importance of inorganic nitrogen

USGS Publications Warehouse

Wickland, Kimberly P.; Aiken, George R.; Butler, Kenna D.; Dornblaser, Mark M.; RGM Spencer,; Striegl, Robert G.

2012-01-01

Northern high-latitude rivers transport large amounts of terrestrially derived dissolved organic matter (DOM) from boreal and arctic ecosystems to coastal areas and oceans. Current knowledge of the biodegradability of DOM in these rivers is limited, particularly for large rivers discharging to the Arctic Ocean. We conducted a seasonally comprehensive study of biodegradable dissolved organic carbon (BDOC) dynamics in the Yukon River and two of its tributaries in Alaska, USA. Distinct seasonal patterns of BDOC, consistent across a wide range of watershed size, indicate BDOC is transported year-round. Relative biodegradability (%BDOC) was greatest during winter, and decreased into spring and summer. Due to large seasonal differences in DOC concentration, the greatest concentrations of BDOC (mg C L−1) occurred during spring freshet, followed by winter and summer. While chemical composition of DOM was an important driver of BDOC, the overriding control of BDOC was mineral nutrient availability due to wide shifts in carbon (C) and nitrogen (N) stoichiometry across seasons. We calculated seasonal and annual loads of BDOC exported by the Yukon River by applying measured BDOC concentrations to daily water discharge values, and also by applying an empirical correlation between %BDOC and the ratio of DOC to dissolved inorganic N (DIN) to total DOC loads. The Yukon River exports ∼0.2 Tg C yr−1 as BDOC that is decomposable within 28 days. This corresponds to 12–18% of the total annual DOC export. Furthermore, we calculate that the six largest arctic rivers, including the Yukon River, collectively export ∼2.3 Tg C yr−1 as BDOC to the Arctic Ocean.

5-methylcytosine promotes mRNA export — NSUN2 as the methyltransferase and ALYREF as an m5C reader

PubMed Central

Yang, Xin; Yang, Ying; Sun, Bao-Fa; Chen, Yu-Sheng; Xu, Jia-Wei; Lai, Wei-Yi; Li, Ang; Wang, Xing; Bhattarai, Devi Prasad; Xiao, Wen; Sun, Hui-Ying; Zhu, Qin; Ma, Hai-Li; Adhikari, Samir; Sun, Min; Hao, Ya-Juan; Zhang, Bing; Huang, Chun-Min; Huang, Niu; Jiang, Gui-Bin; Zhao, Yong-Liang; Wang, Hai-Lin; Sun, Ying-Pu; Yang, Yun-Gui

2017-01-01

5-methylcytosine (m5C) is a post-transcriptional RNA modification identified in both stable and highly abundant tRNAs and rRNAs, and in mRNAs. However, its regulatory role in mRNA metabolism is still largely unknown. Here, we reveal that m5C modification is enriched in CG-rich regions and in regions immediately downstream of translation initiation sites and has conserved, tissue-specific and dynamic features across mammalian transcriptomes. Moreover, m5C formation in mRNAs is mainly catalyzed by the RNA methyltransferase NSUN2, and m5C is specifically recognized by the mRNA export adaptor ALYREF as shown by in vitro and in vivo studies. NSUN2 modulates ALYREF's nuclear-cytoplasmic shuttling, RNA-binding affinity and associated mRNA export. Dysregulation of ALYREF-mediated mRNA export upon NSUN2 depletion could be restored by reconstitution of wild-type but not methyltransferase-defective NSUN2. Our study provides comprehensive m5C profiles of mammalian transcriptomes and suggests an essential role for m5C modification in mRNA export and post-transcriptional regulation. PMID:28418038

Export of earthquake-triggered landslides in active mountain ranges: insights from 2D morphodynamic modelling.

NASA Astrophysics Data System (ADS)

Croissant, Thomas; Lague, Dimitri; Davy, Philippe; Steer, Philippe

2016-04-01

In active mountain ranges, large earthquakes (Mw > 5-6) trigger numerous landslides that impact river dynamics. These landslides bring local and sudden sediment piles that will be eroded and transported along the river network causing downstream changes in river geometry, transport capacity and erosion efficiency. The progressive removal of landslide materials has implications for downstream hazards management and also for understanding landscape dynamics at the timescale of the seismic cycle. The export time of landslide-derived sediments after large-magnitude earthquakes has been studied from suspended load measurements but a full understanding of the total process, including the coupling between sediment transfer and channel geometry change, still remains an issue. Note that the transport of small sediment pulses has been studied in the context of river restoration, but the magnitude of sediment pulses generated by landslides may make the problem different. Here, we study the export of large volumes (>106 m3) of sediments with the 2D hydro-morphodynamic model, Eros. This model uses a new hydrodynamic module that resolves a reduced form of the Saint-Venant equations with a particle method. It is coupled with a sediment transport and lateral and vertical erosion model. Eros accounts for the complex retroactions between sediment transport and fluvial geometry, with a stochastic description of the floods experienced by the river. Moreover, it is able to reproduce several features deemed necessary to study the evacuation of large sediment pulses, such as river regime modification (single-thread to multi-thread), river avulsion and aggradation, floods and bank erosion. Using a synthetic and simple topography we first present how granulometry, landslide volume and geometry, channel slope and flood frequency influence 1) the dominance of pulse advection vs. diffusion during its evacuation, 2) the pulse export time and 3) the remaining volume of sediment in the catchment. The model is then applied to a high resolution (5-10 m) digital elevation model of the Poerua catchment in New Zealand which has been impacted by the effect of a large landslide during the last 15 years. We investigate several plausible Alpine Faults earthquake scenarios to study the propagation of the sediment along a complex river network. We characterize and quantify the sediment pulse export time and mechanism for this river configuration and show its impact on the alluvial plain evolution. Our findings have strong implications for the understanding of aggradation rates and the temporal persistence of induced hazards in the alluvial plain as well as of sediment transfers in active mountain belts.

The Use of Municipal Solid Waste Incineration Ash in Various Building Materials: A Belgian Point of View

PubMed Central

Joseph, Aneeta Mary; Snellings, Ruben; Van den Heede, Philip; Matthys, Stijn

2018-01-01

Huge amounts of waste are being generated, and even though the incineration process reduces the mass and volume of waste to a large extent, massive amounts of residues still remain. On average, out of 1.3 billion tons of municipal solid wastes generated per year, around 130 and 2.1 million tons are incinerated in the world and in Belgium, respectively. Around 400 kT of bottom ash residues are generated in Flanders, out of which only 102 kT are utilized here, and the rest is exported or landfilled due to non-conformity to environmental regulations. Landfilling makes the valuable resources in the residues unavailable and results in more primary raw materials being used, increasing mining and related hazards. Identifying and employing the right pre-treatment technique for the highest value application is the key to attaining a circular economy. We reviewed the present pre-treatment and utilization scenarios in Belgium, and the advancements in research around the world for realization of maximum utilization are reported in this paper. Uses of the material in the cement industry as a binder and cement raw meal replacement are identified as possible effective utilization options for large quantities of bottom ash. Pre-treatment techniques that could facilitate this use are also discussed. With all the research evidence available, there is now a need for combined efforts from incineration and the cement industry for technical and economic optimization of the process flow. PMID:29337887

Large-scale preparation of plasmid DNA.

PubMed

Heilig, J S; Elbing, K L; Brent, R

2001-05-01

Although the need for large quantities of plasmid DNA has diminished as techniques for manipulating small quantities of DNA have improved, occasionally large amounts of high-quality plasmid DNA are desired. This unit describes the preparation of milligram quantities of highly purified plasmid DNA. The first part of the unit describes three methods for preparing crude lysates enriched in plasmid DNA from bacterial cells grown in liquid culture: alkaline lysis, boiling, and Triton lysis. The second part describes four methods for purifying plasmid DNA in such lysates away from contaminating RNA and protein: CsCl/ethidium bromide density gradient centrifugation, polyethylene glycol (PEG) precipitation, anion-exchange chromatography, and size-exclusion chromatography.

Exporting vices: smoking in Asia.

PubMed

Cutler, B

1988-08-01

Marketing statistics of U.S. cigarette exports indicate that despite notable declines in sales at home, sales to foreign countries, especially in Asia, Africa and Latin America, are growing dramatically. World cigarette consumption has doubled since 1960, mainly in less developed countries. In 1987, American tobacco firms increased cigarette exports 76%, or 1 billion in new sales. U.S. smoking dropped in 1985-86 from 30.4 to 26.5% of adults. In Taiwan, tariffs were removed from U.S. cigarettes, lowering prices from $2.86 to 1.30, and raising U.S. imports from $4.4 to 119 million. South Korean trade barriers were removed in May 1988, creating a large market. Japan imports 32% of exported U.S. cigarettes, has 120 million smokers, and is the beneficiary of a massive advertising campaign centered on young people and women. The Asian response to the smoking phenomenon is emerging in the form of restrictions on timing of TV advertising (Japan and Taiwan), health warnings (Japan and Taiwan), and restriction of smoking in public places (Hong Kong).

Climate change decouples oceanic primary and export productivity and organic carbon burial

PubMed Central

Lopes, Cristina; Kucera, Michal; Mix, Alan C.

2015-01-01

Understanding responses of oceanic primary productivity, carbon export, and burial to climate change is essential for model-based projection of biological feedbacks in a high-CO2 world. Here we compare estimates of productivity based on the composition of fossil diatom floras with organic carbon burial off Oregon in the Northeast Pacific across a large climatic transition at the last glacial termination. Although estimated primary productivity was highest during the Last Glacial Maximum, carbon burial was lowest, reflecting reduced preservation linked to low sedimentation rates. A diatom size index further points to a glacial decrease (and deglacial increase) in the fraction of fixed carbon that was exported, inferred to reflect expansion, and contraction, of subpolar ecosystems that today favor smaller plankton. Thus, in contrast to models that link remineralization of carbon to temperature, in the Northeast Pacific, we find dominant ecosystem and sea floor control such that intervals of warming climate had more efficient carbon export and higher carbon burial despite falling primary productivity. PMID:25453073

Plankton networks driving carbon export in the oligotrophic ocean

NASA Astrophysics Data System (ADS)

Guidi, L.; Chaffron, S.; Bittner, L.; Eveillard, D.; Raes, J.; Karsenti, E.; Bowler, C.; Gorsky, G.

2016-02-01

The biological carbon pump is the process by which CO2 is transformed to organic carbon via photosynthesis that sinks to the deep ocean as particles where it is sequestered. While the intensity of the pump correlates with plankton community composition, the underlying ecosystem structure and interactions driving the process remain largely uncharacterised. Here we use environmental and metagenomic data gathered during the Tara Oceans expedition to improve our understanding of the underlying processes. We show that specific plankton communities correlate with carbon export and highlight unexpected and overlooked taxa such as Radiolaria, alveolate parasites, as well as Synechococcus and their phages, as lineages most strongly associated with carbon export in the subtropical oligotrophic ocean. Additionally, we show that the relative abundance of just a few bacterial and viral genes can predict most of the variability in carbon export in these regions. Together these results help elucidate ecosystem drivers of the biological carbon pump and present a case study for scaling from genes-to-ecosystems.

Impact of the natural Fe-fertilization on the magnitude, stoichiometry and efficiency of particulate biogenic silica, nitrogen and iron export fluxes

NASA Astrophysics Data System (ADS)

Lemaitre, N.; Planquette, H.; Dehairs, F.; van der Merwe, P.; Bowie, A. R.; Trull, T. W.; Laurenceau-Cornec, E. C.; Davies, D.; Bollinger, C.; Le Goff, M.; Grossteffan, E.; Planchon, F.

2016-11-01

The Kerguelen Plateau is characterized by a naturally Fe-fertilized phytoplankton bloom that extends more than 1000 km downstream in the Antarctic Circumpolar Current. During the KEOPS2 study, in austral spring, we measured particulate nitrogen (PN), biogenic silica (BSi) and particulate iron (PFe) export fluxes in order to investigate how the natural fertilization impacts the stoichiometry and the magnitude of export fluxes and therefore the efficiency of the biological carbon pump. At 9 stations, we estimated elemental export fluxes based on element concentration to 234Th activity ratios for particulate material collected with in-situ pumps and 234Th export fluxes (Planchon et al., 2015). This study revealed that the natural Fe-fertilization increased export fluxes but to variable degrees. Export fluxes for the bloom impacted area were compared with those of a high-nutrient, low-chlorophyll (HNLC), low-productive reference site located to the south-west of Kerguelen and which had the lowest BSi and PFe export fluxes (2.55 mmol BSi m-2 d-1 and 1.92 μmol PFem-2 d-1) and amongst the lowest PN export flux (0.73 mmol PN m-2 d-1). The impact of the Fe fertilization was the greatest within a meander of the polar front (PF), to the east of Kerguelen, with fluxes reaching 1.26 mmol PN m-2 d-1; 20.4 mmol BSi m-2 d-1 and 22.4 μmol PFe m-2 d-1. A highly productive site above the Kerguelen Plateau, on the contrary, was less impacted by the fertilization with export fluxes reaching 0.72 mmol PN m-2 d-1; 4.50 mmol BSi m-2 d-1 and 21.4 μmol PFe m-2 d-1. Our results suggest that ecosystem features (i.e. type of diatom community) could play an important role in setting the magnitude of export fluxes of these elements. Indeed, for the PF meander, the moderate productivity was sustained by the presence of large and strongly silicified diatom species while at the higher productivity sites, smaller and slightly silicified diatoms dominated. Interestingly, our results suggest that PFe export fluxes can be driven by the lithogenic pool of particles, especially over the Plateau where such inputs from the sediments are important. Finally, for the Plateau and the PF meander, the comparison between PFe export and the particulate PFe stock integrated over the mixed layer depth revealed an efficient PFe export out of the mixed layer at these sites. Export efficiencies (i.e. the ratio between export and uptake) exhibit a very efficient silica pump especially at the HNLC reference station where heavily silicified diatoms were present. On the contrary, the increase with depth of the C:N ratio and the low nitrogen export efficiencies support the idea of a strong remineralization and nitrification activity.

Catalytic and transport cycles of ABC exporters.

PubMed

Al-Shawi, Marwan K

2011-09-07

ABC (ATP-binding cassette) transporters are arguably the most important family of ATP-driven transporters in biology. Despite considerable effort and advances in determining the structures and physiology of these transporters, their fundamental molecular mechanisms remain elusive and highly controversial. How does ATP hydrolysis by ABC transporters drive their transport function? Part of the problem in answering this question appears to be a perceived need to formulate a universal mechanism. Although it has been generally hoped and assumed that the whole superfamily of ABC transporters would exhibit similar conserved mechanisms, this is proving not to be the case. Structural considerations alone suggest that there are three overall types of coupling mechanisms related to ABC exporters, small ABC importers and large ABC importers. Biochemical and biophysical characterization leads us to the conclusion that, even within these three classes, the catalytic and transport mechanisms are not fully conserved, but continue to evolve. ABC transporters also exhibit unusual characteristics not observed in other primary transporters, such as uncoupled basal ATPase activity, that severely complicate mechanistic studies by established methods. In this chapter, I review these issues as related to ABC exporters in particular. A consensus view has emerged that ABC exporters follow alternating-access switch transport mechanisms. However, some biochemical data suggest that alternating catalytic site transport mechanisms are more appropriate for fully symmetrical ABC exporters. Heterodimeric and asymmetrical ABC exporters appear to conform to simple alternating-access-type mechanisms.

A global hotspot for dissolved organic carbon in hypermaritime watersheds of coastal British Columbia

NASA Astrophysics Data System (ADS)

Oliver, Allison A.; Tank, Suzanne E.; Giesbrecht, Ian; Korver, Maartje C.; Floyd, William C.; Sanborn, Paul; Bulmer, Chuck; Lertzman, Ken P.

2017-08-01

The perhumid region of the coastal temperate rainforest (CTR) of Pacific North America is one of the wettest places on Earth and contains numerous small catchments that discharge freshwater and high concentrations of dissolved organic carbon (DOC) directly to the coastal ocean. However, empirical data on the flux and composition of DOC exported from these watersheds are scarce. We established monitoring stations at the outlets of seven catchments on Calvert and Hecate islands, British Columbia, which represent the rain-dominated hypermaritime region of the perhumid CTR. Over several years, we measured stream discharge, stream water DOC concentration, and stream water dissolved organic-matter (DOM) composition. Discharge and DOC concentrations were used to calculate DOC fluxes and yields, and DOM composition was characterized using absorbance and fluorescence spectroscopy with parallel factor analysis (PARAFAC). The areal estimate of annual DOC yield in water year 2015 was 33.3 Mg C km-2 yr-1, with individual watersheds ranging from an average of 24.1 to 37.7 Mg C km-2 yr-1. This represents some of the highest DOC yields to be measured at the coastal margin. We observed seasonality in the quantity and composition of exports, with the majority of DOC export occurring during the extended wet period (September-April). Stream flow from catchments reacted quickly to rain inputs, resulting in rapid export of relatively fresh, highly terrestrial-like DOM. DOC concentration and measures of DOM composition were related to stream discharge and stream temperature and correlated with watershed attributes, including the extent of lakes and wetlands, and the thickness of organic and mineral soil horizons. Our discovery of high DOC yields from these small catchments in the CTR is especially compelling as they deliver relatively fresh, highly terrestrial organic matter directly to the coastal ocean. Hypermaritime landscapes are common on the British Columbia coast, suggesting that this coastal margin may play an important role in the regional processing of carbon and in linking terrestrial carbon to marine ecosystems.

Impacts on quality-induced water scarcity: drivers of nitrogen-related water pollution transfer under globalization from 1995 to 2009

NASA Astrophysics Data System (ADS)

Wan, Liyang; Cai, Wenjia; Jiang, Yongkai; Wang, Can

2016-07-01

Globalization enables the transfer of impacts on water availability. We argue that the threat should be evaluated not only by decrease of quantity, but more importantly by the degradation of water quality in exporting countries. Grouping the world into fourteen regions, this paper establishes a multi-region input-output framework to calculate the nitrogen-related grey water footprint and a water quality-induced scarcity index caused by pollution, for the period of 1995 to 2009. It is discovered that grey water embodied in international trade has been growing faster than total grey water footprint. China, the USA and India were the three top grey water exporters which accounted for more than half the total traded grey water. Dilemma rose when China and India were facing highest grey water scarcity. The EU and the USA were biggest grey water importers that alleviated their water stress by outsourcing water pollution. A structural decomposition analysis is conducted to study the drivers to the evolution of virtual flows of grey water under globalization during the period of 1995 to 2009. The results show that despite the technical progress that offset the growth of traded grey water, structural effects under globalization including both evolution in the globalized economic system and consumption structure, together with consumption volume made a positive contribution. It is found that the structural effect intensified the pollution-induced water scarcity of exporters as it generally increased all nations’ imported grey water while resulting in increases in only a few nations’ exported grey water, such as Brazil, China and Indonesia. At last, drawing from the ‘cap-and-trade’ and ‘boarder-tax-adjustment’ schemes, we propose policy recommendations that ensure water security and achieve environmentally sustainable trade from both the sides of production and consumption.

40 CFR 273.33 - Waste management.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Waste management. 273.33 Section 273...) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.33 Waste management. (a) Universal waste batteries. A large quantity handler of universal waste must manage...

The directory of US coal and technology export resources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-10-01

The purpose of The Directory remains focused on offering a consolidated resource to potential buyers of US coal, coal technology, and expertise. This is consistent with the US policy on coal and coal technology trade, which continues to emphasize export market strategy implementation. Within this context, DOE will continue to support the teaming'' approach to marketing; i.e., vertically integrated large project teams to include multiple industry sectors, such as coal producers, engineering and construction firms, equipment manufacturers, financing and service organizations.

A lake classification concept for a more accurate global estimate of the dissolved inorganic carbon export from terrestrial ecosystems to inland waters.

PubMed

Engel, Fabian; Farrell, Kaitlin J; McCullough, Ian M; Scordo, Facundo; Denfeld, Blaize A; Dugan, Hilary A; de Eyto, Elvira; Hanson, Paul C; McClure, Ryan P; Nõges, Peeter; Nõges, Tiina; Ryder, Elizabeth; Weathers, Kathleen C; Weyhenmeyer, Gesa A

2018-03-26

The magnitude of lateral dissolved inorganic carbon (DIC) export from terrestrial ecosystems to inland waters strongly influences the estimate of the global terrestrial carbon dioxide (CO 2 ) sink. At present, no reliable number of this export is available, and the few studies estimating the lateral DIC export assume that all lakes on Earth function similarly. However, lakes can function along a continuum from passive carbon transporters (passive open channels) to highly active carbon transformers with efficient in-lake CO 2 production and loss. We developed and applied a conceptual model to demonstrate how the assumed function of lakes in carbon cycling can affect calculations of the global lateral DIC export from terrestrial ecosystems to inland waters. Using global data on in-lake CO 2 production by mineralization as well as CO 2 loss by emission, primary production, and carbonate precipitation in lakes, we estimated that the global lateral DIC export can lie within the range of [Formula: see text] to [Formula: see text] Pg C yr -1 depending on the assumed function of lakes. Thus, the considered lake function has a large effect on the calculated lateral DIC export from terrestrial ecosystems to inland waters. We conclude that more robust estimates of CO 2 sinks and sources will require the classification of lakes into their predominant function. This functional lake classification concept becomes particularly important for the estimation of future CO 2 sinks and sources, since in-lake carbon transformation is predicted to be altered with climate change.

Modelling of the estimated contributions of different sub-watersheds and sources to phosphorous export and loading from the Dongting Lake watershed, China.

PubMed

Hou, Ying; Chen, Weiping; Liao, Yuehua; Luo, Yueping

2017-11-03

Considerable growth in the economy and population of the Dongting Lake watershed in Southern China has increased phosphorus loading to the lake and resulted in a growing risk of lake eutrophication. This study aimed to reveal the spatial pattern and sources of phosphorus export and loading from the watershed. We applied an export coefficient model and the Dillon-Rigler model to quantify contributions of different sub-watersheds and sources to the total phosphorus (TP) export and loading in 2010. Together, the upper and lower reaches of the Xiang River watershed and the Dongting Lake Area contributed 60.9% of the TP exported from the entire watershed. Livestock husbandry appeared to be the largest anthropogenic source of TP, contributing more than 50% of the TP exported from each secondary sub-watersheds. The actual TP loading to the lake in 2010 was 62.9% more than the permissible annual TP loading for compliance with the Class III water quality standard for lakes. Three primary sub-watersheds-the Dongting Lake Area, the Xiang River, and the Yuan River watersheds-contributed 91.2% of the total TP loading. As the largest contributor among all sources, livestock husbandry contributed nearly 50% of the TP loading from the Dongting Lake Area and more than 60% from each of the other primary sub-watersheds. This study provides a methodology to identify the key sources and locations of TP export and loading in large lake watersheds. The study can provide a reference for the decision-making for controlling P pollution in the Dongting Lake watershed.

A lake classification concept for a more accurate global estimate of the dissolved inorganic carbon export from terrestrial ecosystems to inland waters

NASA Astrophysics Data System (ADS)

Engel, Fabian; Farrell, Kaitlin J.; McCullough, Ian M.; Scordo, Facundo; Denfeld, Blaize A.; Dugan, Hilary A.; de Eyto, Elvira; Hanson, Paul C.; McClure, Ryan P.; Nõges, Peeter; Nõges, Tiina; Ryder, Elizabeth; Weathers, Kathleen C.; Weyhenmeyer, Gesa A.

2018-04-01

The magnitude of lateral dissolved inorganic carbon (DIC) export from terrestrial ecosystems to inland waters strongly influences the estimate of the global terrestrial carbon dioxide (CO2) sink. At present, no reliable number of this export is available, and the few studies estimating the lateral DIC export assume that all lakes on Earth function similarly. However, lakes can function along a continuum from passive carbon transporters (passive open channels) to highly active carbon transformers with efficient in-lake CO2 production and loss. We developed and applied a conceptual model to demonstrate how the assumed function of lakes in carbon cycling can affect calculations of the global lateral DIC export from terrestrial ecosystems to inland waters. Using global data on in-lake CO2 production by mineralization as well as CO2 loss by emission, primary production, and carbonate precipitation in lakes, we estimated that the global lateral DIC export can lie within the range of {0.70}_{-0.31}^{+0.27} to {1.52}_{-0.90}^{+1.09} Pg C yr-1 depending on the assumed function of lakes. Thus, the considered lake function has a large effect on the calculated lateral DIC export from terrestrial ecosystems to inland waters. We conclude that more robust estimates of CO2 sinks and sources will require the classification of lakes into their predominant function. This functional lake classification concept becomes particularly important for the estimation of future CO2 sinks and sources, since in-lake carbon transformation is predicted to be altered with climate change.

Resolving the Intricacies of Lateral Exports of Inorganic Carbon and Alkalinity from Coastal Salt Marshes

NASA Astrophysics Data System (ADS)

Wang, A. Z.; Chu, S. N.; Kroeger, K. D.; Gonneea, M. E.; Ganju, N. K.

2017-12-01

Dynamic lateral exports of dissolved inorganic carbon (DIC) and total alkalinity (Alk) via tidal exchange from highly productive intertidal marshes are an important piece of puzzle in the coastal carbon cycle, challenging our capability of assessing coastal carbon budgets and projecting future changes under anthropogenic pressure. The effects of these exports on seawater chemistry are profound yet complicated to study. This study presents the latest development of assessing lateral DIC and Alk fluxes from tidal marshes and examining their effects on seawater chemistry and coastal carbon budgets. The study evaluates different approaches to quantify these exports in order to obtain insights on the best and efficient way to capture the dynamics of such exports. A state-of-the-art DIC sensor, Channelized Optical System (CHANOS), was deployed to establish the true DIC fluxes. They are compared to the fluxes derived from empirical modeling and traditional bottle measurements. Salt marshes can acidify and alkalize tidal water by injecting CO2 (DIC) and Alk over a same tidal cycle. However, their generation is decoupled as a result of deferential effects of aerobic and anaerobic respirations. This creates complex scenarios of large swings of seawater chemistry and buffering capacity in tidal water over tidal and seasonal cycles. Marsh exports of DIC and Alk may have complex implications for the future, more acidified ocean. The latest estimates of marsh DIC and Alk exports suggest they are a major term in the marsh carbon budget and can be translated into one of the primary components in the coastal carbon cycle.

Iran: U.S. Concerns and Policy Responses

DTIC Science & Technology

2009-06-22

owns large share of Iran’s total pistachio nut production. Supported Musavi in June 2009 election, purportedly financed much of his campaign. Playing...by U.S. sanctions). Exports to U.S.—$102 million (large categories: pomegranate juice, caviar, pistachio nuts, carpets, medicines, artwork). Imports

Iran: U.S. Concerns and Policy Responses

DTIC Science & Technology

2008-09-04

1997. One of Iran’s richest men, family owns large share of Iran’s total pistachio nut production. President Mahmoud Ahmadinejad Leads faction of...restricted by U.S. sanctions). Exports to U.S. — $173 million (large categories: pomegranate juice, caviar, pistachio nuts, carpets, medicines, artwork

Iran: U.S. Concerns and Policy Responses

DTIC Science & Technology

2009-07-10

One of Iran’s richest men, family owns large share of Iran’s total pistachio nut production. Supported Musavi in June 2009 election, purportedly...is severely restricted by U.S. sanctions). Exports to U.S.—$102 million (large categories: pomegranate juice, caviar, pistachio nuts, carpets

Iran: U.S. Concerns and Policy Responses

DTIC Science & Technology

2008-12-31

1997. One of Iran’s richest men, family owns large share of Iran’s total pistachio nut production. President Mahmoud Ahmadinejad See box...sanctions). Exports to U.S.—$173 million (large categories: pomegranate juice, caviar, pistachio nuts, carpets, medicines, artwork). Imports from U.S

75 FR 5120 - United States, et al. v. Stericycle, Inc., et al.; Proposed Final Judgment and Competitive Impact...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-01

... services for Large Quantity Generator (``LQG'') customers in the states of Kansas, Missouri, Nebraska, and...; Oklahoma City, Oklahoma; Omaha, Nebraska; and Booneville, Missouri; LQG customer contracts associated with... collection and treatment services for large quantity generator (``LQG'') customers. The resulting combination...

Solute and sediment export from Amazon forest and soybean headwater streams.

PubMed

Riskin, Shelby H; Neill, Christopher; Jankowski, KathiJo; Krusche, Alex V; McHorney, Richard; Elsenbeer, Helmut; Macedo, Marcia N; Nunes, Darlisson; Porder, Stephen

2017-01-01

Intensive cropland agriculture commonly increases streamwater solute concentrations and export from small watersheds. In recent decades, the lowland tropics have become the world's largest and most important region of cropland expansion. Although the effects of intensive cropland agriculture on streamwater chemistry and watershed export have been widely studied in temperate regions, their effects in tropical regions are poorly understood. We sampled seven headwater streams draining watersheds in forest (n = 3) or soybeans (n = 4) to examine the effects of soybean cropping on stream solute concentrations and watershed export in a region of rapid soybean expansion in the Brazilian state of Mato Grosso. We measured stream flows and concentrations of NO 3 - , PO 4 3- , SO 4 2- , Cl - , NH 4 + , Ca 2+ , Mg 2+ , Na + , K + , Al 3+ , Fe 3+ , and dissolved organic carbon (DOC) biweekly to monthly to determine solute export. We also measured stormflows and stormflow solute concentrations in a subset of watersheds (two forest, two soybean) during two/three storms, and solutes and δ 18 O in groundwater, rainwater, and throughfall to characterize watershed flowpaths. Concentrations of all solutes except K + varied seasonally in streamwater, but only Fe 3+ concentrations differed between land uses. The highest streamwater and rainwater solute concentrations occurred during the peak season of wildfires in Mato Grosso, suggesting that regional changes in atmospheric composition and deposition influence seasonal stream solute concentrations. Despite no concentration differences between forest and soybean land uses, annual export of NH 4 + , PO 4 3- , Ca 2+ , Fe 3+ , Na + , SO 4 2- , DOC, and TSS were significantly higher from soybean than forest watersheds (5.6-fold mean increase). This increase largely reflected a 4.3-fold increase in water export from soybean watersheds. Despite this increase, total solute export per unit watershed area (i.e., yield) remained low for all watersheds (<1 kg NO 3 - N·ha -1 ·yr -1 , <2.1 kg NH 4 + -N·ha -1 ·yr -1 , <0.2 kg PO 4 3- -P·ha -1 ·yr -1 , <1.5 kg Ca 2+ ·ha -1 ·yr -1 ). Responses of both streamflows and solute concentrations to crop agriculture appear to be controlled by high soil hydraulic conductivity, groundwater-dominated hydrologic flowpaths on deep soils, and the absence of nitrogen fertilization. To date, these factors have buffered streams from the large increases in solute concentrations that often accompany intensive croplands in other locations. © 2016 by the Ecological Society of America.

Food, Feed, or Fuel? Phosphorus Flows Embodied in US Agricultural Production and Trade

NASA Astrophysics Data System (ADS)

MacDonald, G.; Bennett, E.; Carpenter, S.

2012-12-01

Agricultural phosphorus (P) use is integral to sustainable food production and water quality regulation. Globalization of agricultural systems, changing diets, and increasing biofuel production pose new challenges for managing non-renewable P reserves, particularly in key agricultural producing regions such as the US. We used a detailed model of the US agricultural system to assess the quantity of mineral P fertilizers used to produce food crops, livestock, and biofuels relative to the P ultimately consumed in domestic diets. We also quantified linkages in fertilizer use between the US and its trading partners globally via agricultural trade. Feed and livestock production drove by far the largest demand for P fertilizers in the US (56% of all P use for domestic and imported products). Of the total mineral P inputs to US domestic agriculture in 2007 (1905 Gg P), 28% were retained in agricultural soils as surplus P, 40% were lost through processing and waste prior to consumption in human diets, while 10% were diverted directly to biofuel production. One quarter of P fertilizer in the US was required to produce exports, particularly major food and feed crops (corn, soybean, and wheat) that drove a large net P flux out of the country (338 Gg P) with strongly crop-specific effects on soil P imbalances nationally. However, US meat consumption involved considerable reliance on P fertilizer use in other countries to produce red meat imports linked primarily to soil P surpluses abroad. We show that changes in domestic farm management and consumer waste could together reduce the P fertilizer needed to produce food consumed in the US by half, which is comparable to the P fertilizer reduction attainable by cutting domestic meat consumption (44%). More effective distribution of P use for major crops nationally and greater recycling of all agricultural wastes is critical to using US phosphate rock reserves as efficiently as possible while maintaining export-oriented agriculture.

Modeling suspended sediment transport and assessing the impacts of climate change in a karstic Mediterranean watershed.

PubMed

Nerantzaki, S D; Giannakis, G V; Efstathiou, D; Nikolaidis, N P; Sibetheros, I Α; Karatzas, G P; Zacharias, I

2015-12-15

Mediterranean semi-arid watersheds are characterized by a climate type with long periods of drought and infrequent but high-intensity rainfalls. These factors lead to the formation of temporary flow tributaries which present flashy hydrographs with response times ranging from minutes to hours and high erosion rates with significant sediment transport. Modeling of suspended sediment concentration in such watersheds is of utmost importance due to flash flood phenomena, during which, large quantities of sediments and pollutants are carried downstream. The aim of this study is to develop a modeling framework for suspended sediment transport in a karstic watershed and assess the impact of climate change on flow, soil erosion and sediment transport in a hydrologically complex and intensively managed Mediterranean watershed. The Soil and Water Assessment Tool (SWAT) model was coupled with a karstic flow and suspended sediment model in order to simulate the hydrology and sediment yield of the karstic springs and the whole watershed. Both daily flow data (2005-2014) and monthly sediment concentration data (2011-2014) were used for model calibration. The results showed good agreement between observed and modeled values for both flow and sediment concentration. Flash flood events account for 63-70% of the annual sediment export depending on a wet or dry year. Simulation results for a set of IPCC "A1B" climate change scenarios suggested that major decreases in surface flow (69.6%) and in the flow of the springs (76.5%) take place between the 2010-2049 and 2050-2090 time periods. An assessment of the future ecological flows revealed that the frequency of minimum flow events increases over the years. The trend of surface sediment export during these periods is also decreasing (54.5%) but the difference is not statistically significant due to the variability of the sediment. On the other hand, sediment originating from the springs is not affected significantly by climate change. Copyright © 2015 Elsevier B.V. All rights reserved.

77 FR 30260 - Welded Large Diameter Line Pipe From Japan: Notice of Rescission of Antidumping Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-22

... Administration [A-588-857] Welded Large Diameter Line Pipe From Japan: Notice of Rescission of Antidumping Duty... Japan. The review covers five producers/exporters of welded large diameter line pipe from Japan, which... diameter line pipe from Japan for the period December 1, 2010, through November 30, 2011. See Antidumping...

Environmental implications of United States coal exports: a comparative life cycle assessment of future power system scenarios.

PubMed

Bohnengel, Barrett; Patiño-Echeverri, Dalia; Bergerson, Joule

2014-08-19

Stricter emissions requirements on coal-fired power plants together with low natural gas prices have contributed to a recent decline in the use of coal for electricity generation in the United States. Faced with a shrinking domestic market, many coal companies are taking advantage of a growing coal export market. As a result, U.S. coal exports hit an all-time high in 2012, fueled largely by demand in Asia. This paper presents a comparative life cycle assessment of two scenarios: a baseline scenario in which coal continues to be burned domestically for power generation, and an export scenario in which coal is exported to Asia. For the coal export scenario we focus on the Morrow Pacific export project being planned in Oregon by Ambre Energy that would ship 8.8 million tons of Powder River Basin (PRB) coal annually to Asian markets via rail, river barge, and ocean vessel. Air emissions (SOx, NOx, PM10 and CO2e) results assuming that the exported coal is burned for electricity generation in South Korea are compared to those of a business as usual case in which Oregon and Washington's coal plants, Boardman and Centralia, are retrofitted to comply with EPA emissions standards and continue their coal consumption. Findings show that although the environmental impacts of shipping PRB coal to Asia are significant, the combination of superior energy efficiency among newer South Korean coal-fired power plants and lower emissions from U.S. replacement of coal with natural gas could lead to a greenhouse gas reduction of 21% in the case that imported PRB coal replaces other coal sources in this Asian country. If instead PRB coal were to replace natural gas or nuclear generation in South Korea, greenhouse gas emissions per unit of electricity generated would increase. Results are similar for other air emissions such as SOx, NOx and PM. This study provides a framework for comparing energy export scenarios and highlights the importance of complete life cycle assessment in determining net emissions effects resulting from energy export projects and related policy decisions.

No Free Lunch - Trading Away Ecosystem Services from Agriculture in the Brazilian Amazon

NASA Astrophysics Data System (ADS)

Zaks, D.; Foley, J.

2008-12-01

In the age of globalization, many crops and animal products are transported across the long distances for consumption elsewhere. The alteration of water, soil and climate systems from agricultural practices can be attributed to both exporting and importing countries. Quantities of water, carbon and nutrients (e.g. nitrogen and phosphorus) can be tracked throughout the production process and be aggregated from field to table. The synthesis of this data can be used to inform markets to appropriately price the most ecologically efficient production.While agricultural land is undergoing changes around the world, the Brazilian Amazon has seen a dramatic conversion of forest and grassland due to the expanding agricultural frontier, and intense growth in the future has been predicted in the region. As a proof of concept, I plan to study the flow of ecosystem services from the Amazon rainforest basin to the world market. Cattle and soybeans are the two main agricultural products of the region and are produced for both internal consumption and for export. This work quantifies agricultural production and its associated ecosystem services using socio-economic and commodity trade data, numerical ecosystem models and remote sensing products.

Dynamics of dissolved organic matter during four storm events in two forest streams: source, export, and implications for harmful disinfection byproduct formation.

PubMed

Yang, Liyang; Hur, Jin; Lee, Sonmin; Chang, Soon-Woong; Shin, Hyun-Sang

2015-06-01

Dynamics of river dissolved organic matter (DOM) during storm events have profound influences on the downstream aquatic ecosystem and drinking water safety. This study investigated temporal variations in DOM during four storm events in two forest headwater streams (the EH and JH brooks, South Korea) and the impacts on the disinfection byproducts (DBPs) formation potential. The within-event variations of most DOM quantity parameters were similar to the flow rate in the EH but not in the larger JH brook. The dissolved organic carbon (DOC) showed clockwise and counterclockwise hysteresis with the flow rate in the EH and JH brooks, respectively, indicating the importance of both flow path and DOM source pool size in determining the effects of storm events. The stream DOM became less aromatic/humified from the first to the last event in both brooks, probably due to the increasing fresh plant pool and the decreasing leaf litter pool during the course of rainy season. The DOC export during each event increased 1.3-2.7- and 1.1-7.0-fold by stormflows in the EH and JH brooks, respectively. The leaf litter and soil together was the major DOM source, particularly during early events. The enhanced DOM export probably increases the risks of DBPs formation in disinfection, as indicated by a strong correlation observed between DOC and trihalomethanes formation potential (THMFP). High correlations between two humic-like fluorescent components and THMFP further suggested the potential of assessing THMFP with in situ fluorescence sensors during storms.

Changing patterns in the use, recycling, and material substitution of mercury in the United States

USGS Publications Warehouse

Wilburn, David R.

2013-01-01

Environmental concerns have led to numerous regulations that have dramatically decreased the reported production and use of mercury in the United States since the 1980s. Government legislation and subsequent industry actions have led to increased collection of mercury-containing materials and the recovery of mercury through recycling. Mercury emissions have been reduced and effective alternatives to mercury products have been developed for many applications. This study updates and quantifies the changes in demand, supply, use, and material flow for mercury in various sectors in the United States that have taken place since 1996. Nearly all primary mercury produced in the United States is derived as a byproduct of processing of gold and silver ore in Nevada. Since 2001, annual production of mercury from gold and silver mining in Nevada has decreased by 22 percent overall because ore from greater depths containing low grade mercury is recovered, and mercury emissions from this source have decreased by 95 percent as a result of increased regulation and improved collection and suppression technology. The distribution of consumption of mercury in the United States has changed as a result of regulation (elimination of large-scale mercury use in the paint and battery sectors), reduction by consumers (decommissioning of mercury-cell chloralkali manufacturing capacity), and technological advances (improvements in dental, lighting, and wiring sectors). Mercury use in the chloralkali sector, the leading end-use sector in the United States in 1996, has declined by 98 percent from 136 metric tons (t) in 1996 to about 0.3 t in 2010 because of increased processing and recycling efficiencies and plant closures or conversion to other technologies. As plants were closed, mercury recovered from the infrastructure of decommissioned plants has been exported, making the United States a net exporter of mercury, even though no mercury has been produced as the primary product from mines in the United States since 1992. In 1996, the three leading end-use sectors for mercury in the United States were chloralkali manufacturing (accounting for 38 percent of consumption), electrical and electronic instrumentation (13 percent of consumption), and instruments and measuring devices (11 percent of consumption). In 2010, the three leading end-use sectors were dental amalgam (accounting for between 35 and 57 percent of consumption), electrical and electronic instrumentation (29 percent of consumption), and batteries (8 percent of consumption). Mercury use in lighting is increasing because incandescent lights are being phased out in favor of mercury-containing compact fluorescent bulbs, but the demand for mercury per unit produced is small. Dental amalgam constituted the largest amount of mercury in use in the United States. One study reported about 290 t of mercury in dental amalgam was estimated to be contained in human mouths, an estimated 30 t of mercury amalgam was treated as waste, 28.5 t of mercury amalgam was released to the environment, 6 t of amalgam was recycled, and 3.5 t was treated and stored in landfills in 2009. Mercury contained in products recovered by State, municipal, or industry collection activities is recycled, but the estimated overall recycling rate is less than 10 percent. Increasingly, the U.S. mercury recycling industry has been processing a significant amount of mercury-containing material derived from foreign gold mining operations or decommissioned mercury-cell chloralkali plants. Regulation of mercury export and storage is expected to result in surplus mercury inventories in the United States. The Mercury Export Ban Act of 2008 limits elemental mercury exports for unregulated uses such as artisanal gold mining after January 1, 2013, and requires development of adequate long-term storage facilities in the United States for elemental mercury. During the past 4 years, producers and recyclers of elemental mercury have been exporting large quantities of mercury in anticipation of this regulation, but the U.S. inventory of mercury in 2010 was estimated to have exceeded 7,000 t from Government stockpiles and industry stocks. Costs attributed to long-term storage may affect the competitiveness of mercury recycling.

Iran: U.S. Concerns and Policy Responses

DTIC Science & Technology

2009-03-13

One of Iran’s richest men, family owns large share of Iran’s total pistachio nut production. President Mahmoud Ahmadinejad See box later in this...trade is severely restricted by U.S. sanctions). Exports to U.S.—$173 million (large categories: pomegranate juice, caviar, pistachio nuts, carpets

Iran: U.S. Concerns and Policy Responses

DTIC Science & Technology

2009-01-28

speaker during 1981-89 and President 1989-1997. One of Iran’s richest men, family owns large share of Iran’s total pistachio nut production...severely restricted by U.S. sanctions). Exports to U.S.—$173 million (large categories: pomegranate juice, caviar, pistachio nuts, carpets, medicines

Iran: U.S. Concerns and Policy Responses

DTIC Science & Technology

2008-05-06

during 1981-89 and President 1989-1997. One of Iran’s richest men, family owns large share of Iran’s total pistachio nut production. President Mahmoud...restricted by U.S. sanctions). Exports to U.S. — $157 million (large categories: pomegranate juice, caviar, pistachio nuts, carpets, medicines, artwork

Late summer particulate organic carbon export and twilight zone remineralisation in the Atlantic sector of the Southern Ocean

NASA Astrophysics Data System (ADS)

Planchon, F.; Cavagna, A.-J.; Cardinal, D.; André, L.; Dehairs, F.

2012-03-01

During the Bonus-GoodHope (BGH) expedition (Jan-Mar 2008) we studied the water column distribution of total 234Th and biogenic particulate Ba (Baxs) in the Atlantic sector of the Southern Ocean. The objective was to assess the export flux of particulate organic carbon (POC) from the surface to the mesopelagic twilight zone along a section between the Cape Basin and Weddell Gyre. Export production of POC was estimated from steady state and non steady state export fluxes of 234Th which were converted into POC fluxes, using the POC/234Th ratio of large (>53 μm) suspended particles, collected via in-situ pumps. Deficits in 234Th activities were observed at all stations from the surface to the bottom of the mixed-layer. 234Th export fluxes from the upper 100 m ranged from 496 ± 57 dpm m-2 d-1 to 1195 ± 120 dpm m-2 d-1 for the steady state model and from 149 ± 18 dpm m-2 d-1 to 1217 ± 146 dpm m-2 d-1 for the non steady state model calculated for a time window of 15 to 22 days preceding the timing of the present cruise. The POC/234Thp ratio of large, potentially sinking particles (>53 μm), was observed to increase with latitude, from 1.9 ± 0.2 μmol dpm-1 and 1.7 ± 0.3 μmol dpm-1 in the Subtropical Zone (STZ) and Subantarctic Zone (SAZ), respectively, to 3.0 ± 0.2 μmol dpm-1 in the Polar Front Zone (PFZ), 4.8 ± 1.9 μmol dpm-1 at the Southern Antarctic Circumpolar Current Front (SACCF) to 4.1 ± 1.7 μmol dpm-1 in the northern Weddell Gyre, in line with an increasing contribution of larger cell diatoms. Steady state and non steady state POC export from the upper 100 m ranged from 0.9 ± 0.2 mmolC m-2 d-1 to 5.1 ± 2.1 mmolC m-2 d-1 and from 0.3 ± 0.0 mmolC m-2 d-1 to 4.9 ± 3.2 mmolC m-2 d-1, respectively. From the SAZ to the SACCF, non steady state POC export production represented only 15 to 54 % of the steady state POC flux, suggesting that the intensity of export had decreased over time partly due to the fact that regenerated-production based communities of small-sized phytoplankton became predominant. In contrast, for the HNLC area south of the SACCF, we found an excellent agreement between the two modeling approaches indicating that surface POC export remained rather constant there. Estimated POC export represented between 6 to 54 % of the potential export as represented by new production, indicating that export efficiency was particularly low throughout the studied area, except close to the SACCF. Below the export layer, in the mesopelagic zone, 234Th activities generally reached equilibrium with 238U, but sometimes were in large excess relative to 238U (234Th/238U ratio>1.1), reflecting intense remineralisation/disaggregation of 234Th-bearing particles. The accumulation of excess 234Th in the 100-600 m depth interval ranged from 458 ± 55 dpm m-2 d-1 to 3068 ± 368 dpm m-2 d-1. Using POC to 234Th ratio of sinking particles, we converted this 234Th flux into a POC remineralisation flux, which ranged between 0.9 to 9.2 mmolC m-2 d-1. Mesopelagic remineralisation was also evidenced by Baxs inventories which are related to bacterial degradation of sinking material and offer a means to quantify the flux of respired C. Highest biogenic particulate Ba (Baxs) contents were generally observed in the 200-400 m depth interval with values reaching up to >1000 pM in the northern PFZ. Depth weighted average mesopelagic Baxs (meso-Baxs) was high in the PFZ and low in the northernmost (STZ-SAZ) and the southernmost (SACCF-AZ-WG) parts of the BGH section; conversion into respired C flux yielded a range of -0.23 to 6.4 mmolC m-2 d-1. Excluding two outliers, we found a significant positive correlation for mesopelagic waters between POC remineralisation estimated from meso-Baxs and from 234Th excess (R2 = 0.73). Our results indicate that POC export production in this area of the Southern Ocean was strongly attenuated in the mesopelagic waters due to remineralisation, a process which thus appears to strongly impact on longer term bathypelagic zone sequestration of POC.

Using 15-minute acoustic data to analyze suspended-sediment dynamics in the Rio Grande in the Big Bend Region

USGS Publications Warehouse

Dean, David; Topping, David; Griffiths, Ronald; Sabol, Thomas; Schmidt, John C.; Bennett, Jeffery B.

2015-01-01

The Rio Grande in the Big Bend region is subject to rapid geomorphic change consisting of channel narrowing during years of low flow, and channel widening during rare, large, long duration floods. Since the 1940s, there have been large declines in mean and peak stream flow, and the channel has progressively narrowed. Large, channel widening floods are infrequent and have failed to widen the channel to widths measured prior to the onset of channel narrowing in the 1940s. Before the most recent channel-widening flood in September 2008, the Rio Grande in the Big Bend was more than 50 percent narrower than measured in the 1940s. Channel narrowing results in increased flood frequency and flood magnitude due to the loss of channel capacity and flood conveyance (Dean and Schmidt, 2011). Channel narrowing also results in the loss of important aquatic habitats such as backwaters and side-channels, because these habitats accumulate sediment and are converted to floodplains. Environmental managers are attempting to construct an environmental flow program for the purposes of minimizing channel narrowing during low flow years such that channel capacity, flood conveyance, and important aquatic habitats are maintained. Effective mitigation of channel narrowing processes requires an in-depth understanding of the predominant sediment source areas, the quantity of sediment input from those source areas, the parts of the flow regime responsible for the greatest sediment deposition, and the effect of managed flows in ameliorating the sediment loading that occurs within the channel. Here, we analyze data collected with acoustic instrumentation at high temporal resolution to quantify suspended-sediment transport during a variety of flood types. We also investigate the effect of long duration managed flows in promoting sediment export and minimizing channel narrowing.

Eolian Dust and the Origin of Sedimentary Chert

USGS Publications Warehouse

Cecil, C. Blaine

2004-01-01

This paper proposes an alternative model for the primary source of silica contained in bedded sedimentary chert. The proposed model is derived from three principal observations as follows: (1) eolian processes in warm-arid climates produce copious amounts of highly reactive fine-grained quartz particles (dust), (2) eolian processes in warm-arid climates export enormous quantities of quartzose dust to marine environments, and (3) bedded sedimentary cherts generally occur in marine strata that were deposited in warm-arid paleoclimates where dust was a potential source of silica. An empirical integration of these observations suggests that eolian dust best explains both the primary and predominant source of silica for most bedded sedimentary cherts.

Decadal and seasonal trends of nutrient concentration and export from highly managed coastal catchments.

PubMed

Wan, Yongshan; Wan, Lei; Li, Yuncong; Doering, Peter

2017-05-15

Understanding anthropogenic and hydro-climatic influences on nutrient concentrations and export from highly managed catchments often necessitates trend detection using long-term monitoring data. This study analyzed the temporal trend (1979-2014) of total nitrogen (TN) and total phosphorus (TP) concentrations and export from four adjacent coastal basins in south Florida where land and water resources are highly managed through an intricate canal network. The method of integrated seasonal-trend decomposition using LOESS (LOcally weighted regrESSion) was employed for trend detection. The results indicated that long-term trends in TN and TP concentrations (increasing/decreasing) varied with basins and nutrient species, reflecting the influence of basin specific land and water management practices. These long-term trends were intervened by short-term highs driven by high rainfall and discharges and lows associated with regional droughts. Seasonal variations in TP were more apparent than for TN. Nutrient export exhibited a chemostatic behavior for TN from all the basins, largely due to the biogenic nature of organic N associated with the ubiquity of organic materials in the managed canal network. Varying degrees of chemodynamic export was present for TP, reflecting complex biogeochemical responses to the legacy of long-term fertilization, low soil P holding capacity, and intensive stormwater management. The anthropogenic and hydro-climatic influences on nutrient concentration and export behavior had great implications in nutrient loading abatement strategies for aquatic ecosystem restoration of the downstream receiving waterbody. Published by Elsevier Ltd.

Relating management practices and nutrient export in agricultural watersheds of the United States

USGS Publications Warehouse

Sprague, Lori A.; Gronberg, Jo Ann M.

2012-01-01

Relations between riverine export (load) of total nitrogen (N) and total phosphorus (P) from 133 large agricultural watersheds in the United States and factors affecting nutrient transport were evaluated using empirical regression models. After controlling for anthropogenic inputs and other landscape factors affecting nutrient transport-such as runoff, precipitation, slope, number of reservoirs, irrigated area, and area with subsurface tile drains-the relations between export and the area in the Conservation Reserve Program (CRP) (N) and conservation tillage (P) were positive. Additional interaction terms indicated that the relations between export and the area in conservation tillage (N) and the CRP (P) progressed from being clearly positive when soil erodibility was low or moderate, to being close to zero when soil erodibility was higher, to possibly being slightly negative only at the 90th to 95th percentile of soil erodibility values. Possible explanations for the increase in nutrient export with increased area in management practices include greater transport of soluble nutrients from areas in conservation tillage; lagged response of stream quality to implementation of management practices because of nitrogen transport in groundwater, time for vegetative cover to mature, and/or prior accumulation of P in soils; or limitations in the management practice and stream monitoring data sets. If lags are occurring, current nutrient export from agricultural watersheds may still be reflecting the influence of agricultural land-use practices that were in place before the implementation of these management practices.

Iran: U.S. Concerns and Policy Responses

DTIC Science & Technology

2008-11-24

Was Majles (parliament) speaker during 1981-89 and President 1989-1997. One of Iran’s richest men, family owns large share of Iran’s total pistachio nut...320 million (trade is severely restricted by U.S. sanctions). Exports to U.S. — $173 million (large categories: pomegranate juice, caviar, pistachio

Quantity discounts on a virtual good: The results of a massive pricing experiment at King Digital Entertainment

PubMed Central

Levitt, Steven D.; List, John A.; Neckermann, Susanne; Nelson, David

2016-01-01

We report on a natural field experiment on quantity discounts involving more than 14 million consumers. Implementing price reductions ranging from 9–70% for large purchases, we found remarkably little impact on revenue, either positively or negatively. There was virtually no increase in the quantity of customers making a purchase; all the observed changes occurred for customers who already were buyers. We found evidence that infrequent purchasers are more responsive to discounts than frequent purchasers. There was some evidence of habit formation when prices returned to pre-experiment levels. There also was some evidence that consumers contemplating small purchases are discouraged by the presence of extreme quantity discounts for large purchases. PMID:27382146

Continuous summer export of nitrogen-rich organic matter from the Greenland Ice Sheet inferred by ultrahigh resolution mass spectrometry.

PubMed

Lawson, Emily C; Bhatia, Maya P; Wadham, Jemma L; Kujawinski, Elizabeth B

2014-12-16

Runoff from glaciers and ice sheets has been acknowledged as a potential source of bioavailable dissolved organic matter (DOM) to downstream ecosystems. This source may become increasingly significant as glacial melt rates increase in response to future climate change. Recent work has identified significant concentrations of bioavailable carbon and iron in Greenland Ice Sheet (GrIS) runoff. The flux characteristics and export of N-rich DOM are poorly understood. Here, we employed electrospray ionization (ESI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to determine the elemental compositions of DOM molecules in supraglacial water and subglacial runoff from a large GrIS outlet glacier. We provide the first detailed temporal analysis of the molecular composition of DOM exported over a full melt season. We find that DOM pools in supraglacial and subglacial runoff are compositionally diverse and that N-rich material is continuously exported throughout the melt season, as the snowline retreats further inland. Identification of protein-like compounds and a high proportion of N-rich DOM, accounting for 27-41% of the DOM molecules identified by ESI FT-ICR MS, may suggest a microbial provenance and high bioavailability of glacially exported DOM to downstream microbial communities.

Century-long increasing trend and variability of dissolved organic carbon export from the Mississippi River basin driven by natural and anthropogenic forcing

NASA Astrophysics Data System (ADS)

Ren, Wei; Tian, Hanqin; Cai, Wei-Jun; Lohrenz, Steven E.; Hopkinson, Charles S.; Huang, Wei-Jen; Yang, Jia; Tao, Bo; Pan, Shufen; He, Ruoying

2016-09-01

There has been considerable debate as to how natural forcing and anthropogenic activities alter the timing and magnitude of the delivery of dissolved organic carbon (DOC) to the coastal ocean, which has ramifications for the ocean carbon budget, land-ocean interactions, and coastal life. Here we present an analysis of DOC export from the Mississippi River to the Gulf of Mexico during 1901-2010 as influenced by changes in climate, land use and management practices, atmospheric CO2, and nitrogen deposition, through the integration of observational data with a coupled hydrologic/biogeochemical land model. Model simulations show that DOC export in the 2000s increased more than 40% since the 1900s. For the recent three decades (1981-2010), however, our simulated DOC export did not show a significant increasing trend, which is consistent with observations by U.S. Geological Survey. Our factorial analyses suggest that land use and land cover change, including land management practices (LMPs: i.e., fertilization, irrigation, tillage, etc.), were the dominant contributors to the century-scale trend of rising total riverine DOC export, followed by changes in atmospheric CO2, nitrogen deposition, and climate. Decadal and interannual variations of DOC export were largely attributed to year-to-year climatic variability and extreme flooding events, which have been exacerbated by human activity. LMPs show incremental contributions to DOC increase since the 1960s, indicating the importance of sustainable agricultural practices in coping with future environmental changes such as extreme flooding events. Compared to the observational-based estimate, the modeled DOC export was 20% higher, while DOC concentrations were slightly lower. Further refinements in model structure and input data sets should enable reductions in uncertainties in our prediction of century-long trends in DOC.

Cellular Nuclear Export Factors TAP and Aly Are Required for HDAg-L-mediated Assembly of Hepatitis Delta Virus.

PubMed

Huang, Hsiu-Chen; Lee, Chung-Pei; Liu, Hui-Kang; Chang, Ming-Fu; Lai, Yu-Heng; Lee, Yu-Ching; Huang, Cheng

2016-12-09

Hepatitis delta virus (HDV) is a satellite virus of hepatitis B virus (HBV). HDV genome encodes two forms of hepatitis delta antigen (HDAg), small HDAg (HDAg-S), which is required for viral replication, and large HDAg (HDAg-L), which is essential for viral assembly. HDAg-L is identical to HDAg-S except that it bears a 19-amino acid extension at the C terminus. Both HDAgs contain a nuclear localization signal (NLS), but only HDAg-L contains a CRM1-independent nuclear export signal at its C terminus. The nuclear export activity of HDAg-L is important for HDV particle formation. However, the mechanisms of HDAg-L-mediated nuclear export of HDV ribonucleoprotein are not clear. In this study, the host cellular RNA export complex TAP-Aly was found to form a complex with HDAg-L, but not with an export-defective HDAg-L mutant, in which Pro 205 was replaced by Ala. HDAg-L was found to colocalize with TAP and Aly in the nucleus. The C-terminal domain of HDAg-L was shown to directly interact with the N terminus of TAP, whereas an HDAg-L mutant lacking the NLS failed to interact with full-length TAP. In addition, small hairpin RNA-mediated down-regulation of TAP or Aly reduced nuclear export of HDAg-L and assembly of HDV virions. Furthermore, a peptide, TAT-HDAg-L(198-210), containing the 10-amino acid TAT peptide and HDAg-L(198-210), inhibited the interaction between HDAg-L and TAP and blocked HDV virion assembly and secretion. These data demonstrate that formation and release of HDV particles are mediated by TAP and Aly. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Progress and limitations on quantifying nutrient and carbon loading to coastal waters

NASA Astrophysics Data System (ADS)

Stets, E.; Oelsner, G. P.; Stackpoole, S. M.

2017-12-01

Riverine export of nutrients and carbon to estuarine and coastal waters are important determinants of coastal ecosystem health and provide necessary insight into global biogeochemical cycles. Quantification of coastal solute loads typically relies upon modeling based on observations of concentration and discharge from selected rivers draining to the coast. Most large-scale river export models require unidirectional flow and thus are referenced to monitoring locations at the head of tide, which can be located far inland. As a result, the contributions of the coastal plain, tidal wetlands, and concentrated coastal development are often poorly represented in regional and continental-scale estimates of solute delivery to coastal waters. However, site-specific studies have found that these areas are disproportionately active in terms of nutrient and carbon export. Modeling efforts to upscale fluxes from these areas, while not common, also suggest an outsized importance to coastal flux estimates. This presentation will focus on illustrating how the problem of under-representation of near-shore environments impacts large-scale coastal flux estimates in the context of recent regional and continental-scale assessments. Alternate approaches to capturing the influence of the near-coastal terrestrial inputs including recent data aggregation efforts and modeling approaches will be discussed.

Structural basis for amino acid export by DMT superfamily transporter YddG.

PubMed

Tsuchiya, Hirotoshi; Doki, Shintaro; Takemoto, Mizuki; Ikuta, Tatsuya; Higuchi, Takashi; Fukui, Keita; Usuda, Yoshihiro; Tabuchi, Eri; Nagatoishi, Satoru; Tsumoto, Kouhei; Nishizawa, Tomohiro; Ito, Koichi; Dohmae, Naoshi; Ishitani, Ryuichiro; Nureki, Osamu

2016-06-16

The drug/metabolite transporter (DMT) superfamily is a large group of membrane transporters ubiquitously found in eukaryotes, bacteria and archaea, and includes exporters for a remarkably wide range of substrates, such as toxic compounds and metabolites. YddG is a bacterial DMT protein that expels aromatic amino acids and exogenous toxic compounds, thereby contributing to cellular homeostasis. Here we present structural and functional analyses of YddG. Using liposome-based analyses, we show that Escherichia coli and Starkeya novella YddG export various amino acids. The crystal structure of S. novella YddG at 2.4 Å resolution reveals a new membrane transporter topology, with ten transmembrane segments in an outward-facing state. The overall structure is basket-shaped, with a large substrate-binding cavity at the centre of the molecule, and is composed of inverted structural repeats related by two-fold pseudo-symmetry. On the basis of this intramolecular symmetry, we propose a structural model for the inward-facing state and a mechanism of the conformational change for substrate transport, which we confirmed by biochemical analyses. These findings provide a structural basis for the mechanism of transport of DMT superfamily proteins.

Control of nuclear β-dystroglycan content is crucial for the maintenance of nuclear envelope integrity and function.

PubMed

Vélez-Aguilera, Griselda; de Dios Gómez-López, Juan; Jiménez-Gutiérrez, Guadalupe E; Vásquez-Limeta, Alejandra; Laredo-Cisneros, Marco S; Gómez, Pablo; Winder, Steve J; Cisneros, Bulmaro

2018-02-01

β-Dystroglycan (β-DG) is a plasma membrane protein that has ability to target to the nuclear envelope (NE) to maintain nuclear architecture. Nevertheless, mechanisms controlling β-DG nuclear localization and the physiological consequences of a failure of trafficking are largely unknown. We show that β-DG has a nuclear export pathway in myoblasts that depends on the recognition of a nuclear export signal located in its transmembrane domain, by CRM1. Remarkably, NES mutations forced β-DG nuclear accumulation resulting in mislocalization and decreased levels of emerin and lamin B1 and disruption of various nuclear processes in which emerin (centrosome-nucleus linkage and β-catenin transcriptional activity) and lamin B1 (cell cycle progression and nucleoli structure) are critically involved. In addition to nuclear export, the lifespan of nuclear β-DG is restricted by its nuclear proteasomal degradation. Collectively our data show that control of nuclear β-DG content by the combination of CRM1 nuclear export and nuclear proteasome pathways is physiologically relevant to preserve proper NE structure and activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Growing Large Quantities of Containerized Seedlings

Treesearch

Tim Pittman

2002-01-01

The sowing of large quantities of longleaf pine (Pinus palustris Mill.) seed into trays depends on the quality of the seed and the timing of seed sowing. This can be accomplished with mechanization. Seed quality is accomplished by using a gravity table. Tray filling can be accomplished by using a ribbon-type soil mixer and an automated tray-filling...

An effective and simple procedure to isolate abundant quantities of biologically active chemopreventive lunasin-protease inhibitor concentrate (LPIC) from soybean

USDA-ARS?s Scientific Manuscript database

Lunasin is a 5-kDa soybean bioactive peptide with demonstrated anti-cancer and anti-inflammatory properties. The use of lunasin as a chemopreventive agent in large-scale animal studies and human clinical trials is hampered by the paucity of large quantities of lunasin. Recently, purification methods...

Pyruvate dehydrogenase complex (PDC) export from the mitochondrial matrix.

PubMed

Ng, Fanny; Tang, Bor Luen

2014-01-01

Studies on mitochondria protein import had revealed in detail molecular mechanisms of how peptides and proteins could be selectively targeted and translocated across membrane bound organelles. The opposite process of mitochondrial export, while known to occur in various aspects of cellular physiology and pathology, is less well understood. Two very recent reports have indicated that a large mitochondrial matrix protein complex, the pyruvate dehydrogenase complex (PDC) (or its component subunits), could be exported to the lysosomes and the nucleus, respectively. In the case of the latter, evidence was presented to suggest that the entire complex of 8-10 MDa could translocate in its entirety from the mitochondrial matrix to the nucleus upon mitogenic or stress stimuli. We discuss these findings in perspective to what is currently known about the processes of transport in and out of the mitochondrion.

Use and engineering of efflux pumps for the export of olefins in microbes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mukhopadhyay, Aindrila

2016-07-14

The scope of the project is to investigate efflux pump systems in engineered host microorganisms, such as E. coli, and develop a pump engineered to export a target compound. To initiate the project in coordination with other TOTAL driven projects, the first target compound to be studied was 1-hexene. However, we were investigating other chemicals as Styrene. The main goal of the project was to generate a set of optimized efflux pump systems for microorganisms (E. coli and Streptomyces or other host) engineered to contain biosynthetic pathways to export large titers of target compounds that are toxic (or accumulate andmore » push back biosynthesis) to the host cell. An optimized microbial host will utilize specific and efficient cell wall located pumps to extrude harmful target compounds and enable greater production of these compounds.« less

Dissolved Organic Matter Composition and Export from U.S. Rivers

NASA Astrophysics Data System (ADS)

Aiken, G.; Butman, D. E.; Spencer, R. G.; Raymond, P.

2012-12-01

Dissolved organic matter (DOM) chemistry and flux are potentially useful indicators of watershed characteristics, climate influences on watershed hydrology and soils, and changes associated with water and land resource management. Organic source materials, watershed geochemistry, oxidative processes and hydrology strongly influence the nature and reactivity of DOM in aquatic systems. The molecules that comprise DOM, in turn, control a number of environmental processes important for ecosystem function including light penetration and photochemistry, microbial activity, mineral dissolution/precipitation, and the transport and reactivity of hydrophobic compounds and metals. In particular, aromatic molecules derived from higher plants exert strong controls on aquatic photochemistry, and on the transport and biogeochemistry of metals. Assessment of DOM composition and transport, therefore, can provide a basis for understanding watershed processes and biogeochemistry of rivers and streams. Here we present results of a multi-year study designed to assess the seasonal and spatial variability of DOM quantity and quality for 15 large North American river basins. Samples were collected from the mouths of the rivers using a sampling program designed to capture hydrologic and seasonal variability of DOM export. DOM concentrations and composition, based on DOM fractionation on XAD resins, chromophoric dissolved organic matter (CDOM) parameters (ultraviolet /visible absorption and fluorescence spectroscopy), specific compound analyses, and DO14C content varied greatly both between sites and seasonally within a given site. DOM in these rivers exhibited a wide range of concentration and carbon specific ultra-violet absorbance at 254 nm (SUVA254), an optical measurement that is an indicator of DOM aromatic carbon content. In almost all systems, CDOM optical parameters correlated strongly with DOC concentration and hydrophobic organic acid (HPOA) content (aquatic humic substances). In particular, SUVA254 was found to correlate strongly with the proportion of HPOA and Δ14C. Relationships between dissolved organic carbon (DOC) concentration and absorbance for individual rivers were quite variable due to differences in the fraction of non-chromophoric DOM. Notably, the relationship between UV absorption coefficients and DOC concentration for four rivers that drain arid regions and/or are heavily influenced by impoundments were statistically weak.although similar trends for these rivers were not observed for Δ14C. Basins with high discharge, high density of vegetation cover, and low population densities exported younger, more aromatic DOM. Conversely, old DOM was exported from low discharge watersheds draining arid regions and watersheds impacted by high population densities. While individual watershed characteristics control DOC concentrations, CDOM parameters and DO14C content, overall discharge dominated the flux of both CDOM and DO14C to coastal waters. The link between the nature and reactivity of DOM and its optical properties can be exploited to provide powerful monitoring tools to assess the impacts of climate change, land-use change, and management practices on overall water quality and on DOM transport and transformation.

Seasonal exports of phosphorus from intensively fertilised nested grassland catchments.

PubMed

Lewis, Ciaran; Rafique, Rashad; Foley, Nelius; Leahy, Paul; Morgan, Gerard; Albertson, John; Kumar, Sandeep; Kiely, Gerard

2013-09-01

We carried out a one year (2002) study of phosphorus (P) loss from soil to water in three nested grassland catchments with known P input in chemical fertilizer and animal liquid slurry applications. Chemical fertilizer was applied to the grasslands between March and September and animal slurry was applied over the twelve months. The annual chemical P fertilizer applications for the 17 and 211 ha catchments were 16.4 and 23.7 kg P/ha respectively and the annual slurry applications were 10.7 and 14.0 kg P/ha, respectively. The annual total phosphorus (TP) export in stream-flow was 2.61, 2.48 and 1.61 kg P/ha for the 17, 211 and 1524 ha catchments, respectively, compared with a maximum permissible (by regulation) annual export of ca. 0.35 kg P/ha. The export rate (ratio of P export to P in land applications) was 9.6% and 6.6% from the 17 and 211 ha catchments, respectively. On average, 70% of stream flow and 85% of the P export occurred during the five wet months (October to February) indicating that when precipitation is much greater than evaporation, the hydrological conditions are most favourable for P export. However the soil quality and land use history may vary the results. Particulate P made up 22%, 43% and 37% of the TP export at the 17, 211 and 1524 ha catchment areas, respectively. As the chemical fertilizer was spread during the grass growth months (March to September), it has less immediate impact on stream water quality than the slurry applications. We also show that as the catchment scale increases, the P concentrations and P export decrease, confirming dilution due to increasing rural catchment size. In the longer term, the excess P from fertilizer maintains high soil P levels, an antecedent condition favourable to P loss from soil to water. This study confirms the significant negative water quality impact of excess P applications, particularly liquid animal slurry applications in wet winter months. The findings suggest that restricted P application in wet months can largely reduce the P losses from soil to water.

An interactive mapping tool for visualizing lacunarity of laser scanned point clouds

NASA Astrophysics Data System (ADS)

Kania, Adam; Székely, Balázs

2016-04-01

Lacunarity, a measure of the spatial distribution of the empty space in a certain model or real space over large spatial scales, is found to be a useful descriptive quantity in many fields using imagery, including, among others, geology, dentistry, neurology. Its application in ecology was suggested more than 20 years ago. The main problem of its application was the lack of appropriate high resolution data. Nowadays, full-waveform laser scanning, also known as FWF LiDAR, provides the tool for mapping the vegetation in unprecedented details and accuracy. Consequently, the lacunarity concept can be revitalized, in order to study the structure of the vegetation in this sense as well. Calculation of lacunarity, even if it is done in two dimensions (2D), is still has its problems: on one hand it is a number-crunching procedure, on the other hand, it produces 4D results: at each 3D point it returns a set of data that are function of scale. These data sets are difficult to visualize, to evaluate, and to compare. In order to solve this problem, an interactive mapping tool has been conceptualized that is designed to manipulate and visualize the data, lets the user set parameters for best visualization or comparison results. The system is able to load large amounts of data, visualize them as lacunarity curves, or map view as horizontal slices or in 3D point clouds coloured according to the user's choice. Lacunarity maps are presented as a series of (usually) horizontal profiles, e.g. rasters, which cells contain color-mapped values of selected lacunarity of the point cloud. As lacunarity is usually analysed in a series of successive windows sizes, the tool can show a series of rasters with sequentially animated lacunarity maps calculated for various window sizes. A very fast switching of colour schemes is possible to facilitate rapid visual feedback to better understand underlying data patterns exposed by lacunarity functions. In the comparison mode, two sites (or two areas of the same site) can be visualized using the same settings. Basic output/export operations are supported, as well as text and numerical format to utilize the calculated lacunarity values. Furthermore, the system is able to export data to standard georeferenced image and GIS formats enabling further processing and integration with other observational data, like GPS coordinates of forest damages, human influence (illegal tree cut, waste dumps), abundance of species or other ecological indicators. The use of the system is easy to learn and, via the export functionality, it provides interoperability with most of the GIS and other software tools applied in spatial ecological applications. Some LiDAR data of the ChangeHabitats2 project (an IAPP of Marie Curie Actions of the European Commission) have been used for demonstration purposes. BSz contributed as an Alexander von Humboldt Research Fellow.

Biennial Hazardous Waste Report

EPA Pesticide Factsheets

Federal regulations require large quantity generators to submit a report (EPA form 8700-13A/B) every two years regarding the nature, quantities and disposition of hazardous waste generated at their facility.

Linkage of food consumption and export to ammonia emissions in Canada and the overriding implications for mitigation

NASA Astrophysics Data System (ADS)

Sheppard, S. C.; Bittman, S.

2015-02-01

Ammonia (NH3) emissions from agriculture to the atmosphere, along with emissions of other pollutants from a variety of sources, are of concern to agriculture worldwide. National emissions from agricultural sources in Canada are linked to domestic consumption and export demand for agricultural products. The onus to limit emissions is often directed to the producers, but the marketplace and consumer are also responsible for the environmental impact of their choices. This objective of this study was to quantitatively link agricultural NH3 emissions to per person consumption of food and protein and to agricultural exports from Canada. There are substantial differences in the NH3 emissions per unit consumed protein among the various food types. As a result, shifts in the Canadian diet have had a large impact on relative per person NH3 emissions. From 1981 to 2006, the total per person protein intake in the Canadian diet increased about 5%, but NH3 emission related to that diet decreased 20%. This is largely related to consumption of less beef, which has a high emission per unit of meat or protein, and more poultry and cereals which have much lower emissions. Although these changes in diet were not because of environmental concerns by the consumers, they had substantial effects on national-level emissions. These consumer driven effects may well exceed the possible effects of best management practices intended to address NH3 emissions at the producer level. Note that the Canadian population has increased 50% from 1981 to 2006 and meat and egg exports increased 570%, so that total emissions from food production in Canada have increased. Our results imply there will be further effects on national NH3 emissions because of dietary and export drivers that are generally outside the scope of agro-environmental policy.

75 FR 11119 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line, and Pressure Pipe From Japan...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-10

... Carbon and Alloy Seamless Standard, Line, and Pressure Pipe From Japan: Extension of Time Limit for... review of the antidumping duty order on certain large diameter carbon and alloy seamless standard, line... manufacturers/exporters: JFE Steel Corporation; Nippon Steel Corporation; NKK Tubes; and Sumitomo Metal...

Influence of land use and land cover on the spatial variability of dissolved organic matter in multiple aquatic environments.

PubMed

Singh, Shatrughan; Dash, Padmanava; Silwal, Saurav; Feng, Gary; Adeli, Ardeshir; Moorhead, Robert J

2017-06-01

Water quality of lakes, estuaries, and coastal areas serves as an indicator of the overall health of aquatic ecosystems as well as the health of the terrestrial ecosystem that drains to the water body. Land use and land cover plays not only a significant role in controlling the quantity of the exported dissolved organic matter (DOM) but also influences the quality of DOM via various biogeochemical and biodegradation processes. We examined the characteristics and spatial distribution of DOM in five major lakes, in an estuary, and in the coastal waters of the Mississippi, USA, and investigated the influence of the land use and land cover of their watersheds on the DOM composition. We employed absorption and fluorescence spectroscopy including excitation-emission matrix (EEM) combined with parallel factor (PARAFAC) analysis modeling techniques to determine optical properties of DOM and its characteristics in this study. We developed a site-specific PARAFAC model to evaluate DOM characteristics resulting in five diverse DOM compositions that included two terrestrial humic-like (C1 and C3), two microbial humic-like (C2 and C5), and one protein-like (C4) DOM. Our results showed elevated fluorescence levels of microbial humic-like or protein-like DOM in the lakes and coastal waters, while the estuarine waters showed relatively high fluorescence levels of terrestrial humic-like DOM. The results also showed that percent forest and wetland coverage explained 68 and 82% variability, respectively, in terrestrial humic-like DOM exports, while 87% variability in microbially derived humiclike DOM was explained by percent agricultural lands. Strong correlations between microbial humic-like DOM and fluorescence-derived DOM indices such as biological index (BIX) and fluorescence index (FI) indicated autochthonous characteristics in the lakes, while the estuary showed largely allochthonous DOM of terrestrial origin. We also observed higher concentrations of total dissolved phosphorous (TDP) and ammonium nitrogen (NH 4 -N) in coastal waters potentially due to photodegradation of refractory DOM derived from the sediment-bound organic matter in the coastal wetlands. This study highlights the relationships between the DOM compositions in the water and the land use and land cover in the watershed. The spatial variability of DOM in three different types of aquatic environments enhances the understanding of the role of land use and land cover in carbon cycling through export of organic matter to the aquatic ecosystems..

Discovery of Newer Therapeutic Leads for Prostate Cancer

DTIC Science & Technology

2009-06-01

promising plant extracts and then prepare large-scale quantities of the plant extracts using supercritical fluid extraction techniques and use this...quantities of the plant extracts using supercritical fluid extraction techniques. Large scale plant collections were conducted for 14 of the top 20...material for bioassay-guided fractionation of the biologically active constituents using modern chromatography techniques. The chemical structures of

The glacial iron cycle from source to export

NASA Astrophysics Data System (ADS)

Hawkings, J.; Wadham, J. L.; Tranter, M.; Raiswell, R.; Benning, L. G.; Statham, P. J.; Tedstone, A. J.; Nienow, P. W.; Telling, J.; Bagshaw, E.; Simmons, S. L.

2014-12-01

Nutrient availability limits primary production in large sectors of the world's oceans. Iron is the major limiting nutrient in around one third of the oceanic euphotic zone, most significantly in the Southern Ocean proximal to Antarctica. In these areas the availability of bioavailable iron can influence the amount of primary production, and thus the strength of the biological pump and associated carbon drawdown from the atmosphere. Despite experiencing widespread iron limitation, the Polar oceans are among the most productive on Earth. Due to the extreme cold, remoteness and their perceived "stasis", ice sheets have previously been though of as insignificant in global biogeochemical cycles. However, large marine algal blooms have been observed in iron-limited areas where glacial influence is large, and it is possible that these areas are stimulated by glacial bioavailable iron input. Here we discuss the importance of the Greenland and Antarctic ice sheets in the global iron cycle. Using field collected trace element data, bulk meltwater chemistry and mineralogical analysis, including photomicrographs, EELS and XANES, we present, for the first time, a conceptual model of the glacial iron cycle from source to export. Using this data we discuss the sources of iron in glacial meltwater, transportation and alteration through the glacial system, and subsequent export to downstream environments. Data collected in 2012 and 2013 from two different Greenlandic glacial catchments are shown, with the most detailed breakdown of iron speciation and concentrations in glacial areas yet reported. Furthermore, the first data from Greenlandic icebergs is presented, allowing meltwater-derived and iceberg-derived iron export to be compared, and the influence of both in marine productivity to be estimated. Using our conceptual model and flux estimates from our dataset, glacial iron delivery in both the northern and southern hemisphere is discussed. Finally, we compare our flux estimates to other major iron sources to the polar regions such as aeolian dust, and discuss potential implications of increased melting of the ice sheets on the global iron cycle in the future.

Hydrologic controls on the transport and cycling of carbon and nitrogen in a boreal catchment underlain by continuous permafrost

NASA Astrophysics Data System (ADS)

Koch, J. C.; Runkel, R. L.; Striegl, R.; McKnight, D. M.

2013-06-01

ecosystems represent a large carbon (C) reservoir and a substantial source of greenhouse gases. Hydrologic conditions dictate whether C leached from boreal soils is processed in catchments or flushed to less productive environments via the stream. This study quantified hydrologic and biogeochemical C loss from a boreal catchment underlain by frozen silt, where flowpaths may deepen as the active layer thaws over the summer. We hypothesized a decrease in the magnitude of C mineralization over the summer associated with changing flowpaths and decreasing hydrologic connectivity, organic matter lability, and nitrogen (N) availability. Conservative tracers were used to partition C and N loss between catchment export and biogeochemical processing. Coupling tracers with tributary and porewater chemistry indicated C and N cycling in soil flowpaths, with an exponential decrease over the summer. Nitrate was primarily reduced in hillslope flowpaths and the lack of N reaching the stream appeared to limit C mineralization. Stream export accounted for the greatest loss of C, removing 247 and 113 mol hr-1 in the early and late summer, respectively. Reactivity was related to hydrologic connectivity between the soils and stream, which was greatest early in the summer and following a large flood. While a warming climate may increase storage potential in thawed soils, the early-season flush of labile material and late-season runoff through mineral flowpaths may maintain high C export rates. Therefore, we highlight physical export as a dominant cause of aqueous C loss from silty catchments as the Arctic continues to thaw.

International trade causes large net economic losses in tropical countries via the destruction of ecosystem services.

PubMed

Chang, Junning; Symes, William S; Lim, Felix; Carrasco, L Roman

2016-05-01

Despite the large implications of the use of tropical land for exports ("land absorption") on ecosystem services (ES) and global biodiversity conservation, the magnitude of these externalities is not known. We quantify the net value of ES lost in tropical countries as a result of cropland, forestland and pastureland absorption for exports after deducting ES gains through imports ("land displacement"). We find that net ES gains occur only in 7 out of the 41 countries and regions considered. We estimate global annual net losses of over 1.7 x 10(12) international dollars (I$) (I$1.1 x 10(12) if carbon-related services are not considered). After deducting the benefits from agricultural, forest and livestock rents in land replacing tropical forests, the net annual losses are I$1.3 and I$0.7 x 10(12), respectively. The results highlight the large magnitude of tropical ES losses through international trade that are not compensated by the rents of land uses in absorbed land.

Epibenthos of mangrove waterways and open embayments: Community structure and the relationship between exported mangrove detritus and epifaunal standing stocks

NASA Astrophysics Data System (ADS)

Daniel, P. A.; Robertson, A. I.

1990-11-01

The epibenthos inhabiting creek-bottoms in a tidally influenced mangrove forest, a mangrove-lined estuary and several sites in two open embayments, was sampled on four occasions between August 1986 and June 1987. The inshore (mangrove habitats)-offshore (embayment) patterns in total faunal taxonomic richness (means ranging from 0 to 32·5 taxa per trawl) and density (range of means, < 1·55 individuals m -2) were generally complex, with patterns across the gradient changing seasonally. Patterns in total biomass (range of means 0-740 mg.m -2) were clearer, with highest biomasses recorded in May (post-wet season) and lowest in February (mid-wet season), with no significant cross-habitat gradient in biomass. Densities and biomasses were lower than those recorded in other studies, probably owing to the physically harsh conditions available to epibenthos and to the low quality of mangrove detritus as a food source. The significant difference in the structure of epibenthic communities in mangrove and embayment habitats in the dry season months (August and October) was likely due to the longer residence time of water in mangrove water-ways at that time of the year. Greater tidal amplitudes and increased tidal current velocities in February transported mangrove detritus and many faunal taxa into embayments. Variation in the quantities of exported mangrove detritus in nettings explained significant proportions of the variance in total (and component taxa) epibenthic standing stocks in mangrove and embayment habitats. Several factors may be important in causing the positive response of different groups within the epibenthos to mangrove detritus. For penaeid shrimps it seems likely that clumps of exported mangrove detritus provide refuges from predatory fish in both mangrove and embayment habitats.

Carbon Dynamics within Cyclonic Eddies: Insights from a Biomarker Study

PubMed Central

Alonso-González, Iván J.; Arístegui, Javier; Lee, Cindy; Sanchez-Vidal, Anna; Calafat, Antoni; Fabrés, Joan; Sangrá, Pablo; Mason, Evan

2013-01-01

It is generally assumed that episodic nutrient pulses by cyclonic eddies into surface waters support a significant fraction of the primary production in subtropical low-nutrient environments in the northern hemisphere. However, contradictory results related to the influence of eddies on particulate organic carbon (POC) export have been reported. As a step toward understanding the complex mechanisms that control export of material within eddies, we present here results from a sediment trap mooring deployed within the path of cyclonic eddies generated near the Canary Islands over a 1.5-year period. We find that, during summer and autumn (when surface stratification is stronger, eddies are more intense, and a relative enrichment in CaCO3 forming organisms occurs), POC export to the deep ocean was 2–4 times higher than observed for the rest of the year. On the contrary, during winter and spring (when mixing is strongest and the seasonal phytoplankton bloom occurs), no significant enhancement of POC export associated with eddies was observed. Our biomarker results suggest that a large fraction of the material exported from surface waters during the late-winter bloom is either recycled in the mesopelagic zone or bypassed by migrant zooplankton to the deep scattering layer, where it would disaggregate to smaller particles or be excreted as dissolved organic carbon. Cyclonic eddies, however, would enhance carbon export below 1000 m depth during the summer stratification period, when eddies are more intense and frequent, highlighting the important role of eddies and their different biological communities on the regional carbon cycle. PMID:24386098

Carbon dynamics within cyclonic eddies: insights from a biomarker study.

PubMed

Alonso-González, Iván J; Arístegui, Javier; Lee, Cindy; Sanchez-Vidal, Anna; Calafat, Antoni; Fabrés, Joan; Sangrá, Pablo; Mason, Evan

2013-01-01

It is generally assumed that episodic nutrient pulses by cyclonic eddies into surface waters support a significant fraction of the primary production in subtropical low-nutrient environments in the northern hemisphere. However, contradictory results related to the influence of eddies on particulate organic carbon (POC) export have been reported. As a step toward understanding the complex mechanisms that control export of material within eddies, we present here results from a sediment trap mooring deployed within the path of cyclonic eddies generated near the Canary Islands over a 1.5-year period. We find that, during summer and autumn (when surface stratification is stronger, eddies are more intense, and a relative enrichment in CaCO3 forming organisms occurs), POC export to the deep ocean was 2-4 times higher than observed for the rest of the year. On the contrary, during winter and spring (when mixing is strongest and the seasonal phytoplankton bloom occurs), no significant enhancement of POC export associated with eddies was observed. Our biomarker results suggest that a large fraction of the material exported from surface waters during the late-winter bloom is either recycled in the mesopelagic zone or bypassed by migrant zooplankton to the deep scattering layer, where it would disaggregate to smaller particles or be excreted as dissolved organic carbon. Cyclonic eddies, however, would enhance carbon export below 1000 m depth during the summer stratification period, when eddies are more intense and frequent, highlighting the important role of eddies and their different biological communities on the regional carbon cycle.

Sources, distribution and export coefficient of phosphorus in lowland polders of Lake Taihu Basin, China.

PubMed

Huang, Jiacong; Gao, Junfeng; Jiang, Yong; Yin, Hongbin; Amiri, Bahman Jabbarian

2017-12-01

Identifying phosphorus (P) sources, distribution and export from lowland polders is important for P pollution management, however, is challenging due to the high complexity of hydrological and P transport processes in lowland areas. In this study, the spatial pattern and temporal dynamics of P export coefficient (PEC) from all the 2539 polders in Lake Taihu Basin, China were estimated using a coupled P model for describing P dynamics in a polder system. The estimated amount of P export from polders in Lake Taihu Basin during 2013 was 1916.2 t/yr, with a spatially-averaged PEC of 1.8 kg/ha/yr. PEC had peak values (more than 4.0 kg/ha/yr) in the polders near/within the large cities, and was high during the rice-cropping season. Sensitivity analysis based on the coupled P model revealed that the sensitive factors controlling the PEC varied spatially and changed through time. Precipitation and air temperature were the most sensitive factors controlling PEC. Culvert controlling and fertilization were sensitive factors controlling PEC during some periods. This study demonstrated an estimation of PEC from 2539 polders in Lake Taihu Basin, and an identification of sensitive environmental factors affecting PEC. The investigation of polder P export in a watershed scale is helpful for water managers to learn the distribution of P sources, to identify key P sources, and thus to achieve best management practice in controlling P export from lowland areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

Geology and occurrence of ground water in Lyon County, Minnesota

USGS Publications Warehouse

Rodis, Harry G.

1963-01-01

Large quantities of ground water are available from melt-water channels in the county. Moderate quantities, adequate for domestic and small industrial needs, are available from many of the small isolated deposits of sand and gravel in the till. Small quantities of ground water, adequate only for domestic supply, generally can be obtained from Cretaceous sandstone.

Quantity Representation in Children and Rhesus Monkeys: Linear Versus Logarithmic Scales

ERIC Educational Resources Information Center

Beran, Michael J.; Johnson-Pynn, Julie S.; Ready, Christopher

2008-01-01

The performances of 4- and 5-year-olds and rhesus monkeys were compared using a computerized task for quantity assessment. Participants first learned two quantity anchor values and then responded to intermediate values by classifying them as similar to either the large anchor or the small anchor. Of primary interest was an assessment of where the…

Resource Use in Small Island States: Material Flows in Iceland and Trinidad and Tobago, 1961-2008.

PubMed

Krausmann, Fridolin; Richter, Regina; Eisenmenger, Nina

2014-04-01

Iceland and Trinidad and Tobago are small open, high-income island economies with very specific resource-use patterns. This article presents a material flow analysis (MFA) for the two countries covering a time period of nearly five decades. Both countries have a narrow domestic resource base, their economy being largely based on the exploitation of one or two key resources for export production. In the case of Trinidad and Tobago, the physical economy is dominated by oil and natural gas extraction and petrochemical industries, whereas Iceland's economy for centuries has been based on fisheries. More recently, abundant hydropower and geothermal heat were the basis for the establishment of large export-oriented metal processing industries, which fully depend on imported raw materials and make use of domestic renewable electricity. Both countries are highly dependent on these natural resources and vulnerable to overexploitation and price developments. We show how the export-oriented industries lead to high and growing levels of per capita material and energy use and carbon dioxide emissions resulting from large amounts of processing wastes and energy consumption in production processes. The example of small open economies with an industrial production system focused on few, but abundant, key resources and of comparatively low complexity provides interesting insights of how resource endowment paired with availability or absence of infrastructure and specific institutional arrangements drives domestic resource-use patterns. This also contributes to a better understanding and interpretation of MFA indicators, such as domestic material consumption.

Resource Use in Small Island States

PubMed Central

Krausmann, Fridolin; Richter, Regina; Eisenmenger, Nina

2014-01-01

Iceland and Trinidad and Tobago are small open, high-income island economies with very specific resource-use patterns. This article presents a material flow analysis (MFA) for the two countries covering a time period of nearly five decades. Both countries have a narrow domestic resource base, their economy being largely based on the exploitation of one or two key resources for export production. In the case of Trinidad and Tobago, the physical economy is dominated by oil and natural gas extraction and petrochemical industries, whereas Iceland's economy for centuries has been based on fisheries. More recently, abundant hydropower and geothermal heat were the basis for the establishment of large export-oriented metal processing industries, which fully depend on imported raw materials and make use of domestic renewable electricity. Both countries are highly dependent on these natural resources and vulnerable to overexploitation and price developments. We show how the export-oriented industries lead to high and growing levels of per capita material and energy use and carbon dioxide emissions resulting from large amounts of processing wastes and energy consumption in production processes. The example of small open economies with an industrial production system focused on few, but abundant, key resources and of comparatively low complexity provides interesting insights of how resource endowment paired with availability or absence of infrastructure and specific institutional arrangements drives domestic resource-use patterns. This also contributes to a better understanding and interpretation of MFA indicators, such as domestic material consumption. PMID:25505367

Corn-based ethanol production compromises goal of reducing nitrogen export by the Mississippi River.

PubMed

Donner, Simon D; Kucharik, Christopher J

2008-03-18

Corn cultivation in the United States is expected to increase to meet demand for ethanol. Nitrogen leaching from fertilized corn fields to the Mississippi-Atchafalaya River system is a primary cause of the bottom-water hypoxia that develops on the continental shelf of the northern Gulf of Mexico each summer. In this study, we combine agricultural land use scenarios with physically based models of terrestrial and aquatic nitrogen to examine the effect of present and future expansion of corn-based ethanol production on nitrogen export by the Mississippi and Atchafalaya Rivers to the Gulf of Mexico. The results show that the increase in corn cultivation required to meet the goal of 15-36 billion gallons of renewable fuels by the year 2022 suggested by a recent U.S. Senate energy policy would increase the annual average flux of dissolved inorganic nitrogen (DIN) export by the Mississippi and Atchafalaya Rivers by 10-34%. Generating 15 billion gallons of corn-based ethanol by the year 2022 will increase the odds that annual DIN export exceeds the target set for reducing hypoxia in the Gulf of Mexico to >95%. Examination of extreme mitigation options shows that expanding corn-based ethanol production would make the already difficult challenges of reducing nitrogen export to the Gulf of Mexico and the extent of hypoxia practically impossible without large shifts in food production and agricultural management.

Relationship between landscape characteristics and surface water quality.

PubMed

Chang, C L; Kuan, W H; Lui, P S; Hu, C Y

2008-12-01

The effects of landscape characteristics on surface water quality were evaluated in terms of land-use condition, soil type and slope. The case area, the Chichiawan stream in the Wulin catchment in Taiwan, is Formosan landlocked salmon's natural habitat. Due to the agriculture behavior and mankind's activities, the water and environmental quality has gradually worsened. This study applied WinVAST model to predict hydrological responses and non-point source pollution (NPSP) exports in the Wulin catchment. The land-use condition and the slope of land surface in a catchment are major effect factors for watershed responses, including flows and pollutant exports. This work discussed the possible variation of watershed responses induced by the change of land-use condition, soil type and slope, etc. The results show that hydrological responses are highly relative to the value of Curve Number (CN); Pollutant exports have large relation to the average slope of the land surface in the Wulin catchment.

Structural determinants of nuclear export signal orientation in binding to exportin CRM1

DOE PAGES

Fung, Ho Yee Joyce; Fu, Szu -Chin; Brautigam, Chad A.; ...

2015-09-08

The Chromosome Region of Maintenance 1 (CRM1) protein mediates nuclear export of hundreds of proteins through recognition of their nuclear export signals (NESs), which are highly variable in sequence and structure. The plasticity of the CRM1-NES interaction is not well understood, as there are many NES sequences that seem incompatible with structures of the NES-bound CRM1 groove. Crystal structures of CRM1 bound to two different NESs with unusual sequences showed the NES peptides binding the CRM1 groove in the opposite orientation (minus) to that of previously studied NESs (plus). A comparison of minus and plus NESs identified structural and sequencemore » determinants for NES orientation. The binding of NESs to CRM1 in both orientations results in a large expansion in NES consensus patterns and therefore a corresponding expansion of potential NESs in the proteome.« less

Hydrodynamics study on drying of pepper in swirling fluidized bed dryer (SFBD)

NASA Astrophysics Data System (ADS)

Syaif Haron, Nazrul; Hazri Zakaria, Jamal; Faizal Mohideen Batcha, Mohd

2017-08-01

Malaysia is one of the pepper producer with exports quantity reaching more than 90000 tonnes between 2010 until 2016. Drying of pepper is mandatory before their export and at present, pepper was dried by sun drying to reduce cost. This conventional drying method was time consuming and may take four days during rainy season, which retards the production of pepper. This paper proposes the swirling fluidized bed drying (SFBD) method, which was known to have high mixing ability and improved solid-gas contact to shorten the drying time of products. A lab scale SFBD system was constructed to carry out this study. Hydrodynamic study was conducted for three beds loadings of 1.0 kg, 1.4 kg at a drying temperature of 90°C. The SFBD has shown excellent potential to dry the pepper with a relatively short drying time compared to the conventional method. Batch drying for the bed loads studied only took 3 hours of drying time only. It was found that bed higher bed loading of wet pepper requires longer drying time due to higher amount of moisture content in the bed. Four distinct regimes of operation were found during drying in the SFBD and these regimes offer flexibility of operation. The total bed pressure drop was relatively low during drying.

The Water-Energy-Food Nexus in a Rapidly Developing Resource Sector

NASA Astrophysics Data System (ADS)

Allen, D. M.; Kirste, D. M.

2014-12-01

Technological advances and access to global markets have changed the rate at which resource exploitation takes place. The environmental impact of the rapid development and distribution of resources such as minerals and hydrocarbons has led to a greater potential for significant stress on water resources both in terms of quality and quantity. How and where those impacts manifest is crucial to determining appropriate risk management strategies. North East British Columbia has an abundance of shale gas reserves that are anticipated to be exploited at a large scale in coming years, primarily for export as liquefied natural gas (LNG). However, there is growing concern that fracking and other activities related to shale gas development pose risks to water quality and quantity in the region. Water lies at the center of the water-energy-food nexus, with an accelerating water demand for fracking and industrial operations as well as for domestic, environmental and agricultural uses. Climate change is also anticipated to alter the hydrologic regime, posing added stress to the water resource. This case study examines the water-energy-food nexus in the context of a region that is impacted by a rapidly developing resource sector, encompassing water demand/supply, climate change, interaction between deep aquifers and shallow aquifers/surface waters, water quality concerns related to fracking, land use disturbance, and community impacts. Due to the rapid rate of development, there are significant knowledge gaps in our understanding of the water resource. Currently agencies are undertaking water resource assessments and establishing monitoring sites. This research aims to assess water security in North East British Columbia in a coordinated fashion through various partnerships. In addition to collecting baseline knowledge and data, the study will evaluate risk and resilience indicators in relation to water security. A risk assessment framework specific to the shale gas development context will be developed to evaluate the various components of risk spatially and temporally. Resilience is currently being assessed through a comprehensive examination of the current regulatory and policy regime.

Vesicle coating and uncoating: controlling the formation of large COPII-coated carriers

PubMed Central

Townley, Anna K

2009-01-01

The basic mechanisms underlying the formation of coated vesicles are now defined in considerable detail. This article highlights recent developments in our understanding of the problem of exporting large macromolecular cargo such as procollagen from the endoplasmic reticulum and discusses the implications that this has for cell and tissue organisation and human disease. PMID:20401317

Vesicle coating and uncoating: controlling the formation of large COPII-coated carriers.

PubMed

Townley, Anna K; Stephens, David J

2009-08-26

The basic mechanisms underlying the formation of coated vesicles are now defined in considerable detail. This article highlights recent developments in our understanding of the problem of exporting large macromolecular cargo such as procollagen from the endoplasmic reticulum and discusses the implications that this has for cell and tissue organisation and human disease.

78 FR 41366 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line, and Pressure Pipe (Over 4 1/2

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-10

... Carbon and Alloy Seamless Standard, Line, and Pressure Pipe (Over 4 \\1/2\\ Inches) From Japan: Preliminary... seamless standard, line, and pressure pipe (over 4 \\1/2\\ inches) (large diameter seamless pipe) from Japan.../exporters of subject merchandise, Canadian Natural Resources Limited (CNRL), JFE Steel Corporation (JFE...

Terrestrial organic matter as subsidies that aid in the recovery of macroinvertebrates in industrially damaged lakes.

PubMed

Szkokan-Emilson, E J; Wesolek, B E; Gunn, J M

2011-09-01

The importance of allochthonous carbon to the productivity of stream ecosystems in temperate ecozones is well understood, but this relationship is less established in oligotrophic lakes. The nearshore littoral zones, at the interface of terrestrial and aquatic systems, are areas where the influence of terrestrial subsidies is likely greatest. We investigated the response of nearshore communities to variation in the quantity and composition of allochthonous materials, determined the landscape characteristics that regulate the variation of this subsidy, and explored the potential for terrestrial restoration practices to influence the export of organic matter to lakes. Stepwise multiple regressions revealed that diversity of nearshore macroinvertebrate families increased with the amount of fine particulate organic matter (FPOM) captured in sediment traps. The quantity of FPOM (g) increased with forest cover, and the relative amount of FPOM (percentage of total particulate material) in the traps increased with surface area of wetland in the catchments. These models suggest that terrestrially derived subsidies are important in smelter-impacted watersheds, and that the restoration of forests and wetlands will speed the return of nearshore consumer community diversity in industrially damaged lakes.

Aged dissolved organic carbon exported from rivers of the Tibetan Plateau

PubMed Central

Qu, Bin; Sillanpää, Mika; Kang, Shichang; Stubbins, Aron; Yan, Fangping; Aho, Kelly Sue; Zhou, Feng; Raymond, Peter A.

2017-01-01

The role played by river networks in regional and global carbon cycle is receiving increasing attention. Despite the potential of radiocarbon measurements (14C) to elucidate sources and cycling of different riverine carbon pools, there remain large regions such as the climate-sensitive Tibetan Plateau for which no data are available. Here we provide new 14C data on dissolved organic carbon (DOC) from three large Asian rivers (the Yellow, Yangtze and Yarlung Tsangpo Rivers) running on the Tibetan Plateau and present the carbon transportation pattern in rivers of the plateau versus other river system in the world. Despite higher discharge rates during the high flow season, the DOC yield of Tibetan Plateau rivers (0.41 gC m-2 yr-1) was lower than most other rivers due to lower concentrations. Radiocarbon ages of the DOC were older/more depleted (511±294 years before present, yr BP) in the Tibetan rivers than those in Arctic and tropical rivers. A positive correlation between radiocarbon age and permafrost watershed coverage was observed, indicating that 14C-deplted/old carbon is exported from permafrost regions of the Tibetan Plateau during periods of high flow. This is in sharp contrast to permafrost regions of the Arctic which export 14C-enriched carbon during high discharge periods. PMID:28552976

Effect of algal blooms on retention of N, Si and P in Europe's largest coastal lagoon

NASA Astrophysics Data System (ADS)

Vybernaite-Lubiene, I.; Zilius, M.; Giordani, G.; Petkuviene, J.; Vaiciute, D.; Bukaveckas, P. A.; Bartoli, M.

2017-07-01

Nutrient fluxes from land to sea are regulated by climatic factors governing hydrologic loading rates (e.g., storm events, snowmelt) and by internal processes within estuaries that affect nutrient transformation and retention. We compared monthly input and output fluxes of N, Si, and P at the entrance and exit of the hypereutrophic Curonian Lagoon to better understand how seasonal changes in the stoichiometry of nutrient inputs and the occurrence of algal blooms affected nutrient retention within the lagoon. Nutrient ratios were indicative of increasing Si and N limitation during the growing season, and these were associated with a shift from a diatom-based to a cyanobacteria dominated phytoplankton community. The estuary was a net sink for dissolved nutrients, but we observed large interannual difference in the overall retention of N and P. The occurrence of a large cyanobacteria bloom in 2012 was associated with increased export of particulate matter to the Baltic Sea resulting in a net surplus of P export. Bloom conditions mobilized P from sediments and resulted in a shift from net retention to net export for the lagoon. The findings of our study illustrate how changes in nutrient loading ratios influence phytoplankton community composition, which in turn alters the source-sink status of the estuary.

Baseflow contribution to nitrate-nitrogen export from a large, agricultural watershed, USA

USGS Publications Warehouse

Schilling, K.; Zhang, Y.-K.

2004-01-01

Nitrate-nitrogen export from the Raccoon River watershed in west-central Iowa is among the highest in the United State and contributes to impairment of downstream water quality. We examined a rare long-term record of streamflow and nitrate concentration data (1972-2000) to evaluate annual and seasonal patterns of nitrate losses in streamflow and baseflow from the Raccoon River. Combining hydrograph separation with a load estimation program, we estimated that baseflow contributes approximately two-thirds (17.3 kg/ha) of the mean annual nitrate export (26.1 kg/ha). Baseflow transport was greatest in spring and late fall when baseflow contributed more than 80% of the total export. Herein we propose a 'baseflow enrichment ratio' (BER) to describe the relation of baseflow water with baseflow nitrate loads. The long-term ratio of 1.23 for the Raccoon River suggests preferential leaching of nitrate to baseflow. Seasonal patterns of the BER identified the strong link between the baseflow nitrate loads and seasonal crop nitrogen requirements. Study results demonstrate the utility of assessing the baseflow contribution to nitrate loads to identify appropriate control strategies for reducing baseflow delivery of nitrate. ?? 2004 Elsevier B.V. All rights reserved.

Hydrologic controls on DOC, As and Pb export from a polluted peatland - the importance of heavy rain events, antecedent moisture conditions and hydrological connectivity

NASA Astrophysics Data System (ADS)

Broder, T.; Biester, H.

2015-03-01

Bogs can store large amounts of lead (Pb) and arsenic (As) attributed to atmospheric deposition of anthropogenic emissions. Pb and As are exported along with dissolved organic carbon (DOC) in these organic-rich systems, but it is not yet clear which hydrological (pre-)conditions favor their export. This study combines one year continuous monitoring of precipitation, bog water level and pore water concentration changes with bog discharge, DOC, As and Pb stream concentrations and fluxes. Concentrations ranged from 5 to 30 mg L-1 for DOC, 0.2 to 1.9 μg L-1 for As and 1.3 to 12 μg L-1 for Pb with highest concentrations in late summer. As and Pb concentrations significantly correlated with DOC concentrations. Fluxes depended strongly on discharge, as 40% of As and 43% of Pb were exported by the upper 10% of discharge, pointing out the over-proportional contribution of heavy rain and high discharge events to annual As, Pb and DOC export. Exponential increase in element export from the bog is explained by connection of additional DOC, As and Pb pools in the acrotelm during water table rise, which is most pronounced after drought. Pb, As and DOC concentrations in pore water provide evidence of an increase of the soluble Pb pool as soon as the peat layer gets hydrologically connected, while DOC and As peak concentrations in runoff lag in comparison to Pb. Our data indicates a distinct bog-specific discharge threshold of 8 L s-1, which is thought to depend mainly on the bogs size and drainage conditions. Above this threshold element concentration do not further increase and discharge gets diluted. Combining pore water and discharge data shows that As and Pb exports are not only dependent on the amount of precipitation and discharge, but on the frequency and depth of water table fluctuations. Comparing the annual bog As and Pb export with element inventories indicates that As is much more mobilized than Pb, with annual fluxes accounting for 0.85 and 0.27‰ of total As and Pb inventory, respectively.

Hydrological controls on riverine carbon export in a seasonally wet tropical catchment

NASA Astrophysics Data System (ADS)

Duvert, C.; Hutley, L. B.; Bossa, M.; Bird, M. I.; Munksgaard, N.; Wynn, J. G.; Setterfield, S. A.; Northwood, M.

2017-12-01

Understanding the movement of carbon (C) through the landscape is critical for accurate C accounting. Failure to account for the transport of terrestrially-derived C to aquifers and streams can result in a considerable over-estimation of the C sequestration by the biosphere. Here we report on the magnitude of C export via shallow groundwater and adjacent streams in a savanna-covered seasonally wet tropical catchment of northern Australia. Riverine fluxes of carbon dioxide (CO2), dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) were measured at a high resolution over a full year to gain insight into the drivers of C export in this system. Water and C stable isotopes were also measured in order to elucidate water sources and dominant flow pathways. Our results suggest that CO2 evasion was the major process contributing to riverine C loss in the catchment (111 kg C ha-1 yr-1). The downstream export of C was dominated by DOC (78 kg C ha-1 yr-1), while DIC accounted for 39 kg C ha-1 yr-1 of the annual export. The bulk of annual DOC export was flushed out during the very first high-flow events, with export decreasing throughout the wet season to pre-flood levels. In contrast, the DIC flux was more important during flow recession, upon activation of deeper flowpaths carrying geologically-derived C. Shallow groundwater measured in boreholes was supersaturated with CO2 (15,000 < pCO2 < 55,000 ppm), whereas in-stream concentrations were an order of magnitude lower, suggesting substantial outgassing of CO2. Our findings outline the key role of point-source groundwater discharge in riverine CO2 evasion, with C largely sourced from seasonally productive savanna vegetation. Given the complexity of this pathway and the magnitude of this flux, new methods are needed to more precisely quantify CO2 evasion.

Fishing inside or outside? A case studies analysis of potential spillover effect from marine protected areas, using food web models

NASA Astrophysics Data System (ADS)

Colléter, Mathieu; Gascuel, Didier; Albouy, Camille; Francour, Patrice; Tito de Morais, Luis; Valls, Audrey; Le Loc'h, François

2014-11-01

Marine protected areas (MPAs) are implemented worldwide as an efficient tool to preserve biodiversity and protect ecosystems. We used food web models (Ecopath and EcoTroph) to assess the ability of MPAs to reduce fishing impacts on targeted resources and to provide biomass exports for adjacent fisheries. Three coastal MPAs: Bonifacio and Port-Cros (Mediterranean Sea), and Bamboung (Senegalese coast), were used as case studies. Pre-existing related Ecopath models were homogenized and ecosystem characteristics were compared based on network indices and trophic spectra analyses. Using the EcoTroph model, we simulated different fishing mortality scenarios and assessed fishing impacts on the three ecosystems. Lastly, the potential biomass that could be exported from each MPA was estimated. Despite structural and functional trophic differences, the three MPAs showed similar patterns of resistance to simulated fishing mortalities, with the Bonifacio case study exhibiting the highest potential catches and a slightly inferior resistance to fishing. We also show that the potential exports from our small size MPAs are limited and thus may only benefit local fishing activities. Based on simulations, their potential exports were estimated to be at the same order of magnitude as the amount of catch that could have been obtained inside the reserve. In Port Cros, the ban of fishing inside MPA could actually allow for improved catch yields outside the MPA due to biomass exports. This was not the case for the Bonifacio site, as its potential exports were too low to offset catch losses. This insight suggests the need for MPA networks and/or sufficiently large MPAs to effectively protect juveniles and adults and provide important exports. Finally, we discuss the effects of MPAs on fisheries that were not considered in food web models, and conclude by suggesting possible improvements in the analysis of MPA efficiency.

Hydrologic controls on DOC, As and Pb export from a polluted peatland - the importance of heavy rain events, antecedent moisture conditions and hydrological connectivity

NASA Astrophysics Data System (ADS)

Broder, T.; Biester, H.

2015-08-01

Bogs can store large amounts of lead (Pb) and arsenic (As) from atmospheric deposition of anthropogenic emissions. Pb and As are exported along with dissolved organic carbon (DOC) from these organic-rich systems, but it is not yet clear which hydrological (pre)conditions favor their export. This study combines a 1-year monitoring of precipitation, bog water level and pore water concentration changes with bog discharge and DOC, iron, As and Pb stream concentrations. From these data, annual DOC, As, and Pb exports were calculated. Concentrations ranged from 5 to 30 mg L-1 for DOC, 0.2 to 1.9 μg L-1 for As, and 1.3 to 12 μg L-1 for Pb, with highest concentrations in late summer. As and Pb concentrations significantly correlated with DOC concentrations. Fluxes depended strongly on discharge, as 40 % of As and 43 % of Pb were exported during 10 % of the time with the highest discharge, pointing out the over-proportional contribution of short-time, high-discharge events to annual As, Pb and DOC export. Exponential increase in element export from the bog is explained by connection of additional DOC, As and Pb pools in the acrotelm during water table rise, which is most pronounced after drought. Pb, As and DOC concentrations in pore water provide evidence of an increase in the soluble Pb pool as soon as the peat layer becomes hydrologically connected, while DOC and As peak concentrations in runoff lag behind in comparison to Pb. Our data indicate a distinct bog-specific discharge threshold of 8 L s-1, which is thought to depend mainly on the bogs size and drainage conditions. Above this threshold, element concentrations do not further increase and discharge becomes diluted. Combining pore water and discharge data shows that As and Pb exports are dependent on not only the amount of precipitation and discharge but also on the frequency and depth of water table fluctuations. Comparing the annual bog As and Pb export with element inventories indicates that As is much more mobilized than Pb, with annual fluxes accounting for 0.85 and 0.27 ‰ of total As and Pb inventory, respectively.

Apportioning riverine DIN load to export coefficients of land uses in an urbanized watershed.

PubMed

Shih, Yu-Ting; Lee, Tsung-Yu; Huang, Jr-Chuan; Kao, Shuh-Ji; Chang

2016-08-01

The apportionment of riverine dissolved inorganic nitrogen (DIN) load to individual land use on a watershed scale demands the support of accurate DIN load estimation and differentiation of point and non-point sources, but both of them are rarely quantitatively determined in small montane watersheds. We introduced the Danshui River watershed of Taiwan, a mountainous urbanized watershed, to determine the export coefficients via a reverse Monte Carlo approach from riverine DIN load. The results showed that the dynamics of N fluctuation determines the load estimation method and sampling frequency. On a monthly sampling frequency basis, the average load estimation of the methods (GM, FW, and LI) outperformed that of individual method. Export coefficient analysis showed that the forest DIN yield of 521.5kg-Nkm(-2)yr(-1) was ~2.7-fold higher than the global riverine DIN yield (mainly from temperate large rivers with various land use compositions). Such a high yield was attributable to high rainfall and atmospheric N deposition. The export coefficient of agriculture was disproportionately larger than forest suggesting that a small replacement of forest to agriculture could lead to considerable change of DIN load. The analysis of differentiation between point and non-point sources showed that the untreated wastewater (non-point source), accounting for ~93% of the total human-associated wastewater, resulted in a high export coefficient of urban. The inclusion of the treated and untreated wastewater completes the N budget of wastewater. The export coefficient approach serves well to assess the riverine DIN load and to improve the understanding of N cascade. Copyright © 2016 Elsevier B.V. All rights reserved.

Impact of exporting dependence on livestock production systems, industry structure, and research.

PubMed

Macmillan, K L; Kirton, A H

1997-02-01

From 84 to 93% of New Zealand's annual production from livestock is exported to over 100 markets throughout the world. This export dependence has produced production systems that are low-cost because the Mediterranean maritime climate allows animals to graze outdoors throughout the year without provision for housing and with minimal requirements for cropping, harvesting, and forage storage. These systems exploit the inherent tendencies for ruminants to have annual production cycles that can be synchronized to use the seasonal availability of pasture, but this means that processing facilities must handle peak supply for brief periods. Processing technology can reduce the impact of peaks in supply that may not match market demand. The disadvantages of seasonality in processing costs are outweighed by lower production costs, as well as by the opportunity to manage large numbers of animals per labor unit. Cooperative structures that are owned by livestock producers are a common feature, especially in New Zealand's dairy industry. This continued preference for cooperatives may reflect the need to have a guaranteed processor for a perishable product such as milk, as well as sharing the risk in an export industry that has scant control over prices received. In addition, management systems for ruminant livestock can only respond slowly to changes in market demand because their production cycles last at least 12 mo and only one or two offspring are produced in each cycle. Export marketing of livestock products is complicated by trade barriers and by dumping of subsidized surpluses. Negotiations to eliminate these practices may mean that livestock production systems in many countries will have to adopt some principles similar to those developed in New Zealand, not because of export dependence but because this dependence has created low-cost systems.

Global carbon export from the terrestrial biosphere controlled by erosion.

PubMed

Galy, Valier; Peucker-Ehrenbrink, Bernhard; Eglinton, Timothy

2015-05-14

Riverine export of particulate organic carbon (POC) to the ocean affects the atmospheric carbon inventory over a broad range of timescales. On geological timescales, the balance between sequestration of POC from the terrestrial biosphere and oxidation of rock-derived (petrogenic) organic carbon sets the magnitude of the atmospheric carbon and oxygen reservoirs. Over shorter timescales, variations in the rate of exchange between carbon reservoirs, such as soils and marine sediments, also modulate atmospheric carbon dioxide levels. The respective fluxes of biospheric and petrogenic organic carbon are poorly constrained, however, and mechanisms controlling POC export have remained elusive, limiting our ability to predict POC fluxes quantitatively as a result of climatic or tectonic changes. Here we estimate biospheric and petrogenic POC fluxes for a suite of river systems representative of the natural variability in catchment properties. We show that export yields of both biospheric and petrogenic POC are positively related to the yield of suspended sediment, revealing that POC export is mostly controlled by physical erosion. Using a global compilation of gauged suspended sediment flux, we derive separate estimates of global biospheric and petrogenic POC fluxes of 157(+74)(-50) and 43(+61)(-25) megatonnes of carbon per year, respectively. We find that biospheric POC export is primarily controlled by the capacity of rivers to mobilize and transport POC, and is largely insensitive to the magnitude of terrestrial primary production. Globally, physical erosion rates affect the rate of biospheric POC burial in marine sediments more strongly than carbon sequestration through silicate weathering. We conclude that burial of biospheric POC in marine sediments becomes the dominant long-term atmospheric carbon dioxide sink under enhanced physical erosion.

Comparison of export dynamics of nutrients and animal-borne estrogens from a tile-drained Midwestern agroecosystem.

PubMed

Gall, Heather E; Sassman, Stephen A; Jenkinson, Byron; Lee, Linda S; Jafvert, Chad T

2015-04-01

Concentrated animal feeding operations (CAFOs) are known to be a source of nutrients and hormones found in surface water bodies around the world. While the fate and transport of nutrients have been studied for decades, much less research has been conducted on the fate and transport of hormones. To facilitate a comparison of nutrient and hormone export dynamics from farm fields, nitrate + nitrite (N), dissolved reactive phosphorus (DRP), 17α- and 17β-estradiol (E2), estrone (E1), and estriol (E3) were monitored in a tile drain and receiving ditch for one year on a working farm in north central Indiana. Repeated animal waste applications led to high frequency detection of hormones (>50% in tile drain; >90% in the ditch) and nutrients (>70% for DRP; 100% for N). Hydrologic variability was found to be a dominant factor controlling export of N, DRP, and E1 to the drain and ditch. Of the estrogens, the temporal trend in E1 export was most similar to that of DRP. Differences in temporal export between P and the other estrogens likely were due to differences in the biogeochemical processes that affect their fate and transport within the agroecosystem. During short periods when the flowrate exceeded the 80(th) percentile for the year, over 70% of the total mass export of DRP and E1 occurred for the year in both the tile drain and ditch, demonstrating the importance of high-flow events. Therefore, best management practices must be effective during large flow events to substantially reduce transport to downstream locations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Quantity and Quality of Computer Use and Academic Achievement: Evidence from a Large-Scale International Test Program

ERIC Educational Resources Information Center

Cheema, Jehanzeb R.; Zhang, Bo

2013-01-01

This study looked at the effect of both quantity and quality of computer use on achievement. The Program for International Student Assessment (PISA) 2003 student survey comprising of 4,356 students (boys, n = 2,129; girls, n = 2,227) was used to predict academic achievement from quantity and quality of computer use while controlling for…

Quantifying and predicting historical and future patterns of carbon fluxes from the North American Continent to Ocean

NASA Astrophysics Data System (ADS)

Tian, H.; Zhang, B.; Xu, R.; Yang, J.; Yao, Y.; Pan, S.; Lohrenz, S. E.; Cai, W. J.; He, R.; Najjar, R. G.; Friedrichs, M. A. M.; Hofmann, E. E.

2017-12-01

Carbon export through river channels to coastal waters is a fundamental component of the global carbon cycle. Changes in the terrestrial environment, both natural (e.g., climatic change, enriched CO2 concentration, and elevated ozone concentration) and anthropogenic (e.g, deforestation, cropland expansion, and urbanization) have greatly altered carbon production, stocks, decomposition, movement and export from land to river and ocean systems. However, the magnitude and spatiotemporal patterns of lateral carbon fluxes from land to oceans and the underlying mechanisms responsible for these fluxes remain far from certain. Here we applied a process-based land model with explicit representation of carbon processes in stream and rivers (Dynamic Land Ecosystem Model: DLEM 2.0) to examine how changes in climate, land use, atmospheric CO2, and nitrogen deposition have affected the carbon fluxes from North American continent to Ocean during 1980-2015. Our simulated results indicated that terrestrial carbon export shows substantially spatial and temporal variability. Of the five sub-regions (Arctic coast, Pacific coast, Gulf of Mexico, Atlantic coast, and Great lakes), the Arctic sub-region provides the highest DOC flux, whereas the Gulf of Mexico sub-region provided the highest DIC flux. However, terrestrial carbon export to the arctic oceans showed increasing trends for both DOC and DIC, whereas DOC and DIC export to the Gulf of Mexico decreased in the recent decades. Future pattern of riverine carbon fluxes would be largely dependent on the climate change and land use scenarios.

Nucleocytoplasmic Transport of RNAs and RNA-Protein Complexes.

PubMed

Sloan, Katherine E; Gleizes, Pierre-Emmanuel; Bohnsack, Markus T

2016-05-22

RNAs and ribonucleoprotein complexes (RNPs) play key roles in mediating and regulating gene expression. In eukaryotes, most RNAs are transcribed, processed and assembled with proteins in the nucleus and then either function in the cytoplasm or also undergo a cytoplasmic phase in their biogenesis. This compartmentalization ensures that sequential steps in gene expression and RNP production are performed in the correct order and it allows important quality control mechanisms that prevent the involvement of aberrant RNAs/RNPs in these cellular pathways. The selective exchange of RNAs/RNPs between the nucleus and cytoplasm is enabled by nuclear pore complexes, which function as gateways between these compartments. RNA/RNP transport is facilitated by a range of nuclear transport receptors and adaptors, which are specifically recruited to their cargos and mediate interactions with nucleoporins to allow directional translocation through nuclear pore complexes. While some transport factors are only responsible for the export/import of a certain class of RNA/RNP, others are multifunctional and, in the case of large RNPs, several export factors appear to work together to bring about export. Recent structural studies have revealed aspects of the mechanisms employed by transport receptors to enable specific cargo recognition, and genome-wide approaches have provided the first insights into the diverse composition of pre-mRNPs during export. Furthermore, the regulation of RNA/RNP export is emerging as an important means to modulate gene expression under stress conditions and in disease. Copyright © 2015. Published by Elsevier Ltd.

Unleashing Empirical Equations with "Nonlinear Fitting" and "GUM Tree Calculator"

NASA Astrophysics Data System (ADS)

Lovell-Smith, J. W.; Saunders, P.; Feistel, R.

2017-10-01

Empirical equations having large numbers of fitted parameters, such as the international standard reference equations published by the International Association for the Properties of Water and Steam (IAPWS), which form the basis of the "Thermodynamic Equation of Seawater—2010" (TEOS-10), provide the means to calculate many quantities very accurately. The parameters of these equations are found by least-squares fitting to large bodies of measurement data. However, the usefulness of these equations is limited since uncertainties are not readily available for most of the quantities able to be calculated, the covariance of the measurement data is not considered, and further propagation of the uncertainty in the calculated result is restricted since the covariance of calculated quantities is unknown. In this paper, we present two tools developed at MSL that are particularly useful in unleashing the full power of such empirical equations. "Nonlinear Fitting" enables propagation of the covariance of the measurement data into the parameters using generalized least-squares methods. The parameter covariance then may be published along with the equations. Then, when using these large, complex equations, "GUM Tree Calculator" enables the simultaneous calculation of any derived quantity and its uncertainty, by automatic propagation of the parameter covariance into the calculated quantity. We demonstrate these tools in exploratory work to determine and propagate uncertainties associated with the IAPWS-95 parameters.

Deforestation risk due to commodity crop expansion in sub-Saharan Africa

NASA Astrophysics Data System (ADS)

Ordway, Elsa M.; Asner, Gregory P.; Lambin, Eric F.

2017-04-01

Rapid integration of global agricultural markets and subsequent cropland displacement in recent decades increased large-scale tropical deforestation in South America and Southeast Asia. Growing land scarcity and more stringent land use regulations in these regions could incentivize the offshoring of export-oriented commodity crops to sub-Saharan Africa (SSA). We assess the effects of domestic- and export-oriented agricultural expansion on deforestation in SSA in recent decades. Analyses were conducted at the global, regional and local scales. We found that commodity crops are expanding in SSA, increasing pressure on tropical forests. Four Congo Basin countries, Sierra Leone, Liberia, and Côte d’Ivoire were most at risk in terms of exposure, vulnerability and pressures from agricultural expansion. These countries averaged the highest percent forest cover (58% ± 17.93) and lowest proportions of potentially available cropland outside forest areas (1% ± 0.89). Foreign investment in these countries was concentrated in oil palm production (81%), with a median investment area of 41 582 thousand ha. Cocoa, the fastest expanding export-oriented crop across SSA, accounted for 57% of global expansion in 2000-2013 at a rate of 132 thousand ha yr-1. However, cocoa only amounted to 0.89% of foreign land investment. Commodity crop expansion in SSA appears largely driven by small- and medium-scale farmers rather than industrial plantations. Land-use changes associated with large-scale investments remain to be observed in many countries. Although domestic demand for commodity crops was associated with most agricultural expansion, we provide evidence of a growing influence of distant markets on land-use change in SSA.

Large-scale, on-site confirmatory, and varietal testing of a methyl bromide quarantine treatment to control codling moth (Lepidoptera: Tortricidae) in nectarines exported to Japan.

PubMed

Yokoyama, V Y; Miller, G T; Hartsell, P L; Leesch, J G

2000-06-01

In total, 30,491 codling moth, Cydia pomonella (L.), 1-d-old eggs on May Grand nectarines in two large-scale tests, and 17,410 eggs on Royal Giant nectarines in four on-site confirmatory tests were controlled with 100% mortality after fumigation with a methyl bromide quarantine treatment (48 g3 for 2 h at > or = 21 degrees C and 50% volume chamber load) on fruit in shipping containers for export to Japan. Ranges (mean +/- SEM) were for percentage sorption 34.7 +/- 6.2 to 46.5 +/- 2.5, and for concentration multiplied by time products 54.3 +/- 0.9 to 74.5 +/- 0.6 g.h/m3 in all tests. In large-scale tests with May Grand nectarines, inorganic bromide residues 48 h after fumigation ranged from 6.8 +/- 0.7 to 6.9 +/- 0.5 ppm, which were below the U.S. Environmental Protection Agency tolerance of 20 ppm; and, organic bromide residues were < 0.01 ppm after 1 d and < 0.001 ppm after 3 d in storage at 0-1 degree C. After completion of larger-scale and on-site confirmatory test requirements, fumigation of 10 nectarine cultivars in shipping containers for export to Japan was approved in 1995. Comparison of LD50s developed for methyl bromide on 1-d-old codling moth eggs on May Grand and Summer Grand nectarines in 1997 versus those developed for nine cultivars in the previous 11 yr showed no significant differences in codling moth response among the cultivars.

Atmospheric energetics in regions of intense convective activity

NASA Technical Reports Server (NTRS)

Fuelberg, H. E.

1977-01-01

Synoptic-scale budgets of kinetic and total potential energy are computed using 3- and 6-h data at nine times from NASA's fourth Atmospheric Variability Experiment (AVE IV). Two intense squall lines occurred during the period. Energy budgets for areas that enclose regions of intense convection are shown to have systematic changes that relate to the life cycles of the convection. Some of the synoptic-scale energy processes associated with the convection are found to be larger than those observed in the vicinity of mature cyclones. Volumes enclosing intense convection are found to have large values of cross-contour conversion of potential to kinetic energy and large horizontal export of kinetic energy. Although small net vertical transport of kinetic energy is observed, values at individual layers indicate large upward transport. Transfer of kinetic energy from grid to subgrid scales of motion occurs in the volumes. Latent heat release is large in the middle and upper troposphere and is thought to be the cause of the observed cyclic changes in the budget terms. Total potential energy is found to be imported horizontally in the lower half of the atmosphere, transported aloft, and then exported horizontally. Although local changes of kinetic energy and total potential energy are small, interaction between volumes enclosing convection with surrounding larger volumes is quite large.

Floodplain restoration enhances denitrification and reach-scale nitrogen removal in an agricultural stream.

PubMed

Roley, Sarah S; Tank, Jennifer L; Stephen, Mia L; Johnson, Laura T; Beaulieu, Jake J; Witter, Jonathan D

2012-01-01

Streams of the agricultural Midwest, USA, export large quantities of nitrogen, which impairs downstream water quality, most notably in the Gulf of Mexico. The two-stage ditch is a novel restoration practice, in which floodplains are constructed alongside channelized ditches. During high flows, water flows across the floodplains, increasing benthic surface area and stream water residence time, as well as the potential for nitrogen removal via denitrification. To determine two-stage ditch nitrogen removal efficacy, we measured denitrification rates in the channel and on the floodplains of a two-stage ditch in north-central Indiana for one year before and two years after restoration. We found that instream rates were similar before and after the restoration, and they were influenced by surface water NO3- concentration and sediment organic matter content. Denitrification rates were lower on the constructed floodplains and were predicted by soil exchangeable NO3- concentration. Using storm flow simulations, we found that two-stage ditch restoration contributed significantly to NO3- removal during storm events, but because of the high NO3- loads at our study site, < 10% of the NO3- load was removed under all storm flow scenarios. The highest percentage of NO3- removal occurred at the lowest loads; therefore, the two-stage ditch's effectiveness at reducing downstream N loading will be maximized when the practice is coupled with efforts to reduce N inputs from adjacent fields.

Permafrost and lakes control river isotope composition across a boreal Arctic transect in the Western Siberian lowlands

NASA Astrophysics Data System (ADS)

Ala-aho, P.; Soulsby, C.; Pokrovsky, O. S.; Kirpotin, S. N.; Karlsson, J.; Serikova, S.; Manasypov, R.; Lim, A.; Krickov, I.; Kolesnichenko, L. G.; Laudon, H.; Tetzlaff, D.

2018-03-01

The Western Siberian Lowlands (WSL) store large quantities of organic carbon that will be exposed and mobilized by the thawing of permafrost. The fate of mobilized carbon, however, is not well understood, partly because of inadequate knowledge of hydrological controls in the region which has a vast low-relief surface area, extensive lake and wetland coverage and gradually increasing permafrost influence. We used stable water isotopes to improve our understanding of dominant landscape controls on the hydrology of the WSL. We sampled rivers along a 1700 km South-North transect from permafrost-free to continuous permafrost repeatedly over three years, and derived isotope proxies for catchment hydrological responsiveness and connectivity. We found correlations between the isotope proxies and catchment characteristics, suggesting that lakes and wetlands are intimately connected to rivers, and that permafrost increases the responsiveness of the catchment to rainfall and snowmelt events, reducing catchment mean transit times. Our work provides rare isotope-based field evidence that permafrost and lakes/wetlands influence hydrological pathways across a wide range of spatial scales (10-105 km2) and permafrost coverage (0%-70%). This has important implications, because both permafrost extent and lake/wetland coverage are affected by permafrost thaw in the changing climate. Changes in these hydrological landscape controls are likely to alter carbon export and emission via inland waters, which may be of global significance.

Chlorine-36 as a tracer of perchlorate origin

USGS Publications Warehouse

Sturchio, N.C.; Caffee, M.; Beloso, Abelardo D.; Heraty, L.J.; Böhlke, J.K.; Hatzinger, P.B.; Jackson, W.A.; Gu, B.; Heikoop, J.M.; Dale, M.

2009-01-01

Perchlorate (ClO4-) is ubiquitous in the environment. It is produced naturally by atmospheric photochemical reactions, and also is synthesized in large quantities for military, aerospace, and industrial applications. Nitrate-enriched salt deposits of the Atacama Desert (Chile) contain high concentrations of natural ClO4-, and have been exported worldwide since the mid-1800s for use in agriculture. The widespread introduction of synthetic and agricultural ClO4- into the environment has contaminated numerous municipal water supplies. Stable isotope ratio measurements of Cl and O have been applied for discrimination of different ClO4- sources in the environment. This study explores the potential of 36Cl measurements for further improving the discrimination of ClO4- sources. Groundwater and desert soil samples from the southwestern United States (U.S.) contain ClO4- having high 36Cl abundances (36Cl/Cl = 3100 ?? 10-15 to 28,800 ?? 10 -15), compared with those from the Atacama Desert (36Cl/Cl = 0.9 ?? 10-15 to 590 ?? 10-15) and synthetic ClO4- reagents and products (36Cl/Cl = 0.0 ?? 10-15 to 40 ?? 1015). In conjunction with stable Cl and O isotope ratios, 36Cl data provide a clear distinction among three principal. ClO4- source types in the environment of the southwestern U.S. ?? 2009 American Chemical Society.

EMERALD: Coping with the Explosion of Seismic Data

NASA Astrophysics Data System (ADS)

West, J. D.; Fouch, M. J.; Arrowsmith, R.

2009-12-01

The geosciences are currently generating an unparalleled quantity of new public broadband seismic data with the establishment of large-scale seismic arrays such as the EarthScope USArray, which are enabling new and transformative scientific discoveries of the structure and dynamics of the Earth’s interior. Much of this explosion of data is a direct result of the formation of the IRIS consortium, which has enabled an unparalleled level of open exchange of seismic instrumentation, data, and methods. The production of these massive volumes of data has generated new and serious data management challenges for the seismological community. A significant challenge is the maintenance and updating of seismic metadata, which includes information such as station location, sensor orientation, instrument response, and clock timing data. This key information changes at unknown intervals, and the changes are not generally communicated to data users who have already downloaded and processed data. Another basic challenge is the ability to handle massive seismic datasets when waveform file volumes exceed the fundamental limitations of a computer’s operating system. A third, long-standing challenge is the difficulty of exchanging seismic processing codes between researchers; each scientist typically develops his or her own unique directory structure and file naming convention, requiring that codes developed by another researcher be rewritten before they can be used. To address these challenges, we are developing EMERALD (Explore, Manage, Edit, Reduce, & Analyze Large Datasets). The overarching goal of the EMERALD project is to enable more efficient and effective use of seismic datasets ranging from just a few hundred to millions of waveforms with a complete database-driven system, leading to higher quality seismic datasets for scientific analysis and enabling faster, more efficient scientific research. We will present a preliminary (beta) version of EMERALD, an integrated, extensible, standalone database server system based on the open-source PostgreSQL database engine. The system is designed for fast and easy processing of seismic datasets, and provides the necessary tools to manage very large datasets and all associated metadata. EMERALD provides methods for efficient preprocessing of seismic records; large record sets can be easily and quickly searched, reviewed, revised, reprocessed, and exported. EMERALD can retrieve and store station metadata and alert the user to metadata changes. The system provides many methods for visualizing data, analyzing dataset statistics, and tracking the processing history of individual datasets. EMERALD allows development and sharing of visualization and processing methods using any of 12 programming languages. EMERALD is designed to integrate existing software tools; the system provides wrapper functionality for existing widely-used programs such as GMT, SOD, and TauP. Users can interact with EMERALD via a web browser interface, or they can directly access their data from a variety of database-enabled external tools. Data can be imported and exported from the system in a variety of file formats, or can be directly requested and downloaded from the IRIS DMC from within EMERALD.

Economic benefits of high value medicinal plants to Pakistani communities: an analysis of current practice and potential.

PubMed

Sher, Hassan; Aldosari, Ali; Ali, Ahmad; de Boer, Hugo J

2014-10-10

Poverty is pervasive in the Swat Valley, Pakistan. Most of the people survive by farming small landholdings. Many earn additional income by collecting and selling plant material for use in herbal medicine. This material is collected from wild populations but the people involved have little appreciation of the potential value of the plant material they collect and the long term impact their collecting has on local plant populations. In 2012, existing practices in collecting and trading high value minor crops from Swat District, Pakistan, were analyzed. The focus of the study was on the collection pattern of medicinal plants as an economic activity within Swat District and the likely destinations of these products in national or international markets. Local collectors/farmers and dealers were surveyed about their collection efforts, quantities collected, prices received, and resulting incomes. Herbal markets in major cities of Pakistan were surveyed for current market trends, domestic sources of supply, imports and exports of herbal material, price patterns, and market product-quality requirements. It was observed that wild collection is almost the only source of medicinal plant raw material in the country, with virtually no cultivation. Gathering is mostly done by women and children of nomadic Middle Hill tribes who earn supplementary income through this activity, with the plants then brought into the market by collectors who are usually local farmers. The individuals involved in gathering and collecting are largely untrained regarding the pre-harvest and post-harvest treatment of collected material. Most of the collected material is sold to local middlemen. After that, the trade pattern is complex and heterogeneous, involving many players. Pakistan exports of high value plants generate over US$10.5 million annually in 2012, with a substantial percentage of the supply coming from Swat District, but its market share has been declining. Reasons for the decline were identified as unreliable and often poor quality of the material supplied, length of the supply chain, and poor marketing strategies. These problems can be addressed by improving the knowledge of those at the start of the supply chain, improving linkages among all steps in the chain, and developing sustainable harvesting practices.

Short-term benefits from central unit commitment and dispatch: Application to the Southern African Power Pool

NASA Astrophysics Data System (ADS)

Bowen, Brian Hugh

1998-12-01

Electricity utilities in the Southern African region are conscious that gains could be made from more economically efficient trading but have had no tools with which to analyze the effects of a change in policy. This research is the first to provide transparent quantitative techniques to quantify the impacts of new trading arrangements in this region. The study poses a model of the recently formed Southern African Power Pool, built with the collaboration of the region's national utilities to represent each country's demand and generation/transmission system. The multi-region model includes commitment and dispatch from diverse hydrothermal sources over a vast area. Economic gains are determined by comparing the total costs under free-trade conditions with those from the existing fixed-trade bilateral arrangements. The objective function minimizes production costs needed to meet total demand, subject to each utility's constraints for thermal and hydro generation, transmission, load balance and losses. Linearized thermal cost functions are used along with linearized input output hydropower plant curves and hydrothermal on/off status variables to formulate a mixed-integer programming problem. Results from the modeling show that moving to optimal trading patterns could save between 70 million and 130 million per year. With free-trade policies the quantity of power flow between utilities is doubled and maximum usage is made of the hydropower stations thus reducing costs and fuel use. In electricity exporting countries such as Zambia and Mozambique gains from increased trade are achieved which equal 16% and 18% respectively of the value of their total manufactured exports. A sensitivity analysis is conducted on the possible effects of derating generation, derating transmission and reducing water inflows but gains remain large. Maximum economic gains from optimal trading patterns can be achieved by each country allowing centralized control through the newly founded SAPP coordination center. Using standard mixed integer programming solvers makes the cost of such modeling activity easily affordable to each utility in the Southern African pool. This research provides the utilities with the modeling tools to quantify the gains from increased trade and thereby furthers a move towards greater efficiency, faster economic growth and reduced use of fossil fuels.

An Analysis of Current Energy Policy Initiatives in New Mexico. What are the Potential Impacts to the State's Water Resources?

NASA Astrophysics Data System (ADS)

Klise, G. T.; Hart, W. E.; Kobos, P. H.; Malczynski, L. A.; Tidwell, V. C.

2008-12-01

Population in New Mexico is increasing rapidly with recent projections showing that the state will add more than 1 million people by 2035. This growth will create a demand for additional energy and water supplies that have yet to be developed. New Mexico currently exports about 50% of the energy generated within the state to neighboring states, and existing power plants predominately utilize traditional fossil fuels such as coal, oil and natural gas. Because traditional electric generation technologies utilize large quantities of water, New Mexico can also be seen as exporting water for the benefit of electricity consumed in neighboring states. As it is, both surface water and groundwater supplies are stretched thin and these internal and external stresses stemming from population growth will have a substantial impact on the state's water resources. In 2004, the Governor laid out a plan to make New Mexico a "Clean Energy State" by implementing renewable portfolio standards, developing renewable energy transmission infrastructure, creating an alternative energy innovation fund and creating state specific tax credits for renewable energy production and manufacturing. Recent work in the National Energy-Water Roadmap has pointed out that certain renewable sources of energy utilize less water than traditional power plants, and technological fixes to existing power plants will result in less water consumption. If New Mexico carries out its energy initiative, what will be the impacts to the state's water resources? Will it be possible to meet competing demands for this water? These questions and others will be analyzed in a decision-support tool that can look at the connection between both the physical and economic systems to see what the tradeoffs might be as a result of specific policy decisions. The ability to plan for future energy needs and understanding potential impacts to the state's limited water resources will be an invaluable tool for decision-makers in New Mexico. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

When siting works, Canada-style.

PubMed

Rabe, B G

1992-01-01

Hazardous waste management poses increasing problems for Canadian provinces and American states, given the vast quantities and types of wastes generated and the virtual inability to open new storage, treatment, or disposal facilities. The Canadian experience is very similar to the American one in many respects, except for the fact that three provinces (Alberta, Manitoba, and Quebec) have devised alternative approaches to siting that appear successful in moving beyond the political gridlock so common on this issue. In each of these cases, traditional, top-down approaches to siting have been eschewed in favor of a more comprehensive approach that includes extensive public participation, economic and social compensation packages, formal partnerships between public and private organizations, and direct links between siting proposals and other aspects of waste management, including waste reduction, recycling, and export/import control.

Zero-gravity quantity gaging system

NASA Technical Reports Server (NTRS)

1989-01-01

The Zero-Gravity Quantity Gaging System program is a technology development effort funded by NASA-LeRC and contracted by NASA-JSC to develop and evaluate zero-gravity quantity gaging system concepts suitable for application to large, on-orbit cryogenic oxygen and hydrogen tankage. The contract effective date was 28 May 1985. During performance of the program, 18 potential quantity gaging approaches were investigated for their merit and suitability for gaging two-phase cryogenic oxygen and hydrogen in zero-gravity conditions. These approaches were subjected to a comprehensive trade study and selection process, which found that the RF modal quantity gaging approach was the most suitable for both liquid oxygen and liquid hydrogen applications. This selection was made with NASA-JSC concurrence.

Examination of Land Use, Hydrology, and Perceptions of Use and Management of the Colombian Paramo with Implications for Water Quality and Availability Concerns for Affected Watersheds

NASA Astrophysics Data System (ADS)

Tyson, A. F.; Covino, T.; Riveros-Iregui, D. A.; Gonzalez-Pinzon, R.

2015-12-01

The Northern and Central Andes have experienced greater anthropogenic land use/land-cover (LULC) change than nearly any other high mountain system on Earth. In particular, páramo ecosystems, high elevation grasslands of the tropical Andes of Colombia, are undergoing rapid conversion to cropland and pasture. These systems have strong hydrologic buffering capacity and have historically provided consistent freshwater flows to downstream communities. Therefore, loss of these systems could threaten the viability of freshwater resources in the region. While this region has some of the highest runoff ratios, precipitation, and largest river flows in the world, the resiliency of these hydrologic systems and the influence LULC change may have on them remains poorly understood. Here we seek to develop a deeper understanding of these relationships through quantitative analyses of LULC change and impacts on the quantity and quality of water exported from páramo landscapes of Colombia. Our results indicate the intensity and spatial distribution of LULC change, build upon past remote sensing studies of the region, and aid in prioritizing areas of concern for hydrologic research on the ground. This information provides an initial framework for characterizing the degree of modification and impact to water quantity/quality, as well as the long-term sustainability of water resources in the region. We highlight the complexities of watershed management practices in the Colombian páramo and the need to account for the impact of human activity on changes in water quantity and quality in the region.

Rapid post-seismic landslide evacuation boosted by dynamic river width and implications for sediment fluxes during the seismic cycle

NASA Astrophysics Data System (ADS)

Steer, Philippe; Croissant, Thomas; Lague, Dimitri; Davy, Philippe

2017-04-01

Mass wasting caused by large magnitude earthquakes choke mountain rivers with several cubic kilometers of sediment. The timescale and mechanisms by which rivers evacuate the coarse fraction of small to gigantic landslide deposits are poorly known, but are critical to predict post-seismic hydro-sedimentary hazards, interpret the signature of earthquakes in sedimentary archives and decipher the coupling between erosion and tectonics. Here, we use a new 2D hydro-sedimentary evolution model to demonstrate that river self-organization into a narrower alluvial channel overlying the bedrock valley dramatically increases sediment transport capacity of coarse sediments and reduces export time of gigantic landslides by orders of magnitude compared to existing theory. Predicted export times obey a universal non-linear relationship function of landslide volume and pre-landslide valley transport capacity. Dynamic alluvial channel narrowing is therefore a key, previously unrecognized, mechanism by which mountain rivers rapidly digest extreme events and maintain their capacity to incise uplifted rocks. Upscaling these results to realistic populations of landslides show that removing half of the total sediment volume introduced by large earthquakes in the fluvial network would typically last 5 to 25 years in various tectonically active mountain belts, with little impact of topography and climate. If several studies indicate a strong dependency of total landslide volume to earthquake magnitude, our study show that the sediment export time of a landslide population is not strongly impacted by earthquake magnitude or by the total volume of the landslide population. Building on these new findings, we then investigate the dynamics of mountainous landscapes submitted to a series of earthquakes, following either a Gutenberg-Richter distribution or a single large magnitude event. We infer the temporal and spatial evolution of the number of active landslide deposits, of the sediment load along the fluvial network and of the exported sediment flux throughout several seismic cycles. These results highlight how landscapes and sediment fluxes respond on longer time scales to a succession of earthquakes able to trigger landslides.

The influence of shelf processes in delivering dissolved iron to the HNLC waters of the Drake Passage, Antarctica

NASA Astrophysics Data System (ADS)

Measures, C. I.; Brown, M. T.; Selph, K. E.; Apprill, A.; Zhou, M.; Hatta, M.; Hiscock, W. T.

2013-06-01

Dissolved trace element distributions near Elephant Island in the Drake Passage show extremely high levels of dissolved Fe and Mn in waters above the shelf. The entrainment of this enriched shelf water by the Fe-poor Antarctic Circumpolar Current (ACC) as it passes through the Shackleton Gap delivers an estimated 2.8×106 mol yr-1 dissolved Fe to the offshore waters of the Drake Passage. The magnitude and spatial distribution of dissolved Fe, Mn and Al over the shelf are consistent with a diagenetically produced sedimentary source, but are inconsistent with eolian or upwelling sources. The systematics of the Mn and Fe concentrations suggest that there are two distinct sources of dissolved Fe to the surface waters of this region. The highest Fe concentrations are associated with Bransfield Strait water, which can be identified by its characteristic temperature and salinity (T/S) properties both inside the Bransfield Strait and in the Bransfield Current outflow between Elephant and Clarence Islands. Most of the shelf area is dominated by a second water type with T/S properties that are typical of modified Antarctic Surface Water, which while also enriched has a lower Fe:Mn ratio. The predominantly linear relationships between the Fe and Mn concentrations at the stations in each of these water mass types suggest that the distribution of these elements is largely controlled by physical mixing processes and that biological removal of Fe on the shelf, while certainly occurring, is limited, perhaps as a result of rapid physical flushing processes and relatively slow biological growth rates. The consequent export of large quantities of this shelf-derived Fe into the ACC is likely responsible for the extensive regions of enhanced primary production seen in satellite imagery downstream of the Drake Passage.

Study of Polyolefines Waste Thermo-Destruction in Large Laboratory and in Industrial Installations

DTIC Science & Technology

2014-12-15

coke ”–waste after thermo-destruction carried out on the module No 2 showed an content to 46.1% of ash [20]. This ash content indicates a very large... coke (post-production waste) from the wastes thermo-destruction on 2 modules of vertical modular installation for thermo-destruction of used polymer...of receivedwaste water, the quantity of received coke , the quantity of gaseous product in periods of carrying out installation work before (first

Tanzania Country Analysis Brief

EIA Publications

2016-01-01

Tanzania is a small natural gas producer, but the country is planning to become an exporter of liquefied natural gas (LNG) in the future. There have been several natural gas discoveries made in offshore southern Tanzania since 2010 large enough to support an LNG plant.

7 CFR 1493.80 - Evidence of export.

Code of Federal Regulations, 2014 CFR

2014-01-01

... OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Export Credit Guarantee Program (GSM-102) and CCC Intermediate Export Credit Guarantee Program (GSM-103) Operations § 1493.80 Evidence of export. (a) Report of export. The exporter is required to provide CCC an evidence of export...

7 CFR 1493.80 - Evidence of export.

Code of Federal Regulations, 2013 CFR

2013-01-01

... OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Export Credit Guarantee Program (GSM-102) and CCC Intermediate Export Credit Guarantee Program (GSM-103) Operations § 1493.80 Evidence of export. (a) Report of export. The exporter is required to provide CCC an evidence of export...

7 CFR 1493.80 - Evidence of export.

Code of Federal Regulations, 2012 CFR

2012-01-01

... OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Export Credit Guarantee Program (GSM-102) and CCC Intermediate Export Credit Guarantee Program (GSM-103) Operations § 1493.80 Evidence of export. (a) Report of export. The exporter is required to provide CCC an evidence of export...

Who is eating up the world's aquifers? Unsustainable irrigation embedded in global food trade.

NASA Astrophysics Data System (ADS)

Dalin, C.; Wada, Y.; Kastner, T.; Puma, M. J.

2016-12-01

Recent hydrological modelling and Earth observations have located and quantified alarming groundwater depletion over the world. This is primarily due to water withdrawals for irrigation, but the connections with their main driver, global food consumption, have not yet been explored. We provide the first quantification of groundwater depletion embedded in the world's food trade by combining unique global, crop-specific estimates of non-renewable groundwater abstraction with international food trade. We show that approximately ten percent of non-renewable groundwater irrigation use is embedded in food trade, of which two thirds are exported by Pakistan, the United States and India alone. A vast majority of the world's population lives in countries sourcing nearly all their staple crop imports from partners who deplete groundwater to produce these crops, highlighting unsustainablility of global food production and water use. Groups of countries are found particularly exposed to decreased food supply as they both produce and import food irrigated from quickly depleting aquifers. Figure caption: Embedded groundwater depletion in international trade of crop commodities in 2010 (km3/y). Large importing nations are shown in bold, italic font and large exporters in bold, underlined font. Ribbons' colors indicate the country of export. Note that, for clarity, we only display the links with a weight of at least 1% that of the largest link.

75 FR 29514 - Export Trade Certificate of Review

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-26

... Operation described below in the following Export Trade and Export Markets: Export Trade Export Product ALCC... being headed and gutted. Export Markets The Export Markets include all parts of the world except the... engage in Export Trade in the Export Markets, ALCC and its Members may undertake the following activities...

Investigations needed to stimulate the development of Jordan's mineral resources

USGS Publications Warehouse

McKelvey, V.E.

1979-01-01

The level of living that any society can attain is a direct function of the use it makes of all kinds of raw materials (soil, water, metals, nonmetals, etc.), all kinds of energy (both animate and inanimate), and all kinds of human ingenuity; and is an inverse function of the size of the population that must share the collective product. The relation between raw materials, energy and ingenuity is such that use of a large amount of one may offset the need for large amounts of others. The most vital raw materials are water, soil, and construction materials, for these are needed in large quantities and are hard to import. Metals, chemicals, and inanimate energy are necessary for industrialization. The more of these minerals a nation possess, the better, but not nation can hope to be self-sufficient in all of the m and therefore must trade for some essential materials. Jordan’s natural resources have been little explored. The grantitc-metamorphic terrane in the southeastern part of the Kingdom could contain deposits of tungsten, rare earths, feldspar, mica, fluorite etc. and the sedimentary terrane over much of the rest of the county is favorable for the occurrence of oil. Even if none of these minerals is found, however, Jordan’s other mineral resource, if fully explored and developed in the light of modern technology, will support a far higher level of living than her people now enjoy. Very likely she can increase her rainfall by about 10 percent by cloud seeding, and she undeveloped supplies in both surface and ground water that are sufficient to nearly double her usable water supply. Even if she does not have oil or have it in large quantities, she can buy it cheaply from neighboring counties, and in addition has undeveloped sources of hydroelectric power, large reserves of bituminous limestone, large reserves of nuclear power as uranium in phosphate rock, and can use solar and wind power for special purposes. Her large supplies of construction, fertilizer, and other chemical raw materials will not only satisfy her own needs, but will yield both raw materials and some manufactured products for export. And she has valuable resource of touristic interest in the form of incomparable scenery, antiquities, and holy places, which, if properly advertised, could well become her largest single source of foreign currency. Revenues obtained from this source and from the export of agricultural products, nonmetallic minerals, and mineral products should support foreign oil purchase of oil, machinery, and other products not mined or produced internally. Full development of Jordan’s economic potential will take years to achieve and involves many complex activities. One of the most essential is one that can be pressed in the early years, namely the gathering of facts and basic data concerning the character, extent, and distribution of her resources, and the uses that can be made of them. Without each fundamental data or the understanding of their meaning or the ways to use and apply them, costly developmental projects and similar efforts to raise the level of living are likely to have limited success at best. Basic data and mineral resources are best gathered and published by permanent government agencies, for private organizations and individual cannot afford to take the risks involved in gathering data that may not have an immediate economic return; and even if private parties do collect such data they are not likely to make them general available. Of the activities needed in the field of mineral resources, some are already underway as the established function of government agencies. No bureau however, seems to have responsibility for making geologic maps and for gathering data on such things as steam flow, composition and properties of minerals and rocks, or for investigating the uses to which Jordan’s minerals might be put. To satisfy these needs, a Geological Survey and a Bureau of Mineral Industries should be formed and placed in operation as quickly as possible. The task of collecting and interpreting basic data or mineral resources must be done largely by Jordanians, for only in this way will Jordan acquire the technical competence needed to use the information. Few Jordanians have enough training or experience to work independently in these fields now, however, so help from outside technicians would be necessary over an initial training period of several years. But the number of outside technicians should never exceed the number of Jordanian technicians, and for this reason, neither organization could have a staff of more than a few people during the early years of operation.

The Exported Chaperone PfHsp70x Is Dispensable for the Plasmodium falciparum Intraerythrocytic Life Cycle.

PubMed

Cobb, David W; Florentin, Anat; Fierro, Manuel A; Krakowiak, Michelle; Moore, Julie M; Muralidharan, Vasant

2017-01-01

Export of parasite proteins into the host erythrocyte is essential for survival of Plasmodium falciparum during its asexual life cycle. While several studies described key factors within the parasite that are involved in protein export, the mechanisms employed to traffic exported proteins within the host cell are currently unknown. Members of the Hsp70 family of chaperones, together with their Hsp40 cochaperones, facilitate protein trafficking in other organisms, and are thus likely used by P. falciparum in the trafficking of its exported proteins. A large group of Hsp40 proteins is encoded by the parasite and exported to the host cell, but only one Hsp70, P. falciparum Hsp70x (PfHsp70x), is exported with them. PfHsp70x is absent in most Plasmodium species and is found only in P. falciparum and closely related species that infect apes. Herein, we have utilized clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 genome editing in P. falciparum to investigate the essentiality of PfHsp70x. We show that parasitic growth was unaffected by knockdown of PfHsp70x using both the dihydrofolate reductase (DHFR)-based destabilization domain and the glmS ribozyme system. Similarly, a complete gene knockout of PfHsp70x did not affect the ability of P. falciparum to proceed through its intraerythrocytic life cycle. The effect of PfHsp70x knockdown/knockout on the export of proteins to the host red blood cell (RBC), including the critical virulence factor P. falciparum erythrocyte membrane protein 1 (PfEMP1), was tested, and we found that this process was unaffected. These data show that although PfHsp70x is the sole exported Hsp70, it is not essential for the asexual development of P. falciparum . IMPORTANCE Half of the world's population lives at risk for malaria. The intraerythrocytic life cycle of Plasmodium spp. is responsible for clinical manifestations of malaria; therefore, knowledge of the parasite's ability to survive within the erythrocyte is needed to combat the deadliest agent of malaria, P. falciparum . An outstanding question in the field is how P. falciparum undertakes the essential process of trafficking its proteins within the host cell. In most organisms, chaperones such as Hsp70 are employed in protein trafficking. Of the Plasmodium species causing human disease, the chaperone PfHsp70x is unique to P. falciparum , and it is the only parasite protein of its kind exported to the host (S. Külzer et al., Cell Microbiol 14:1784-1795, 2012). This has placed PfHsp70x as an ideal target to inhibit protein trafficking and kill the parasite. However, we show that PfHsp70x is not required for export of parasite effectors and it is not essential for parasite survival inside the RBC.

Climate change increases riverine carbon outgassing, while export to the ocean remains uncertain

NASA Astrophysics Data System (ADS)

Langerwisch, F.; Walz, A.; Rammig, A.; Tietjen, B.; Thonicke, K.; Cramer, W.

2016-07-01

Any regular interaction of land and river during flooding affects carbon pools within the terrestrial system, riverine carbon and carbon exported from the system. In the Amazon basin carbon fluxes are considerably influenced by annual flooding, during which terrigenous organic material is imported to the river. The Amazon basin therefore represents an excellent example of a tightly coupled terrestrial-riverine system. The processes of generation, conversion and transport of organic carbon in such a coupled terrigenous-riverine system strongly interact and are climate-sensitive, yet their functioning is rarely considered in Earth system models and their response to climate change is still largely unknown. To quantify regional and global carbon budgets and climate change effects on carbon pools and carbon fluxes, it is important to account for the coupling between the land, the river, the ocean and the atmosphere. We developed the RIVerine Carbon Model (RivCM), which is directly coupled to the well-established dynamic vegetation and hydrology model LPJmL, in order to account for this large-scale coupling. We evaluate RivCM with observational data and show that some of the values are reproduced quite well by the model, while we see large deviations for other variables. This is mainly caused by some simplifications we assumed. Our evaluation shows that it is possible to reproduce large-scale carbon transport across a river system but that this involves large uncertainties. Acknowledging these uncertainties, we estimate the potential changes in riverine carbon by applying RivCM for climate forcing from five climate models and three CO2 emission scenarios (Special Report on Emissions Scenarios, SRES). We find that climate change causes a doubling of riverine organic carbon in the southern and western basin while reducing it by 20 % in the eastern and northern parts. In contrast, the amount of riverine inorganic carbon shows a 2- to 3-fold increase in the entire basin, independent of the SRES scenario. The export of carbon to the atmosphere increases as well, with an average of about 30 %. In contrast, changes in future export of organic carbon to the Atlantic Ocean depend on the SRES scenario and are projected to either decrease by about 8.9 % (SRES A1B) or increase by about 9.1 % (SRES A2). Such changes in the terrigenous-riverine system could have local and regional impacts on the carbon budget of the whole Amazon basin and parts of the Atlantic Ocean. Changes in riverine carbon could lead to a shift in the riverine nutrient supply and pH, while changes in the exported carbon to the ocean lead to changes in the supply of organic material that acts as a food source in the Atlantic. On larger scales the increased outgassing of CO2 could turn the Amazon basin from a sink of carbon to a considerable source. Therefore, we propose that the coupling of terrestrial and riverine carbon budgets should be included in subsequent analysis of the future regional carbon budget.

Phosphorus and dissolved organic carbon export during peak flow periods in three small homogenous catchments in eastern Germany

NASA Astrophysics Data System (ADS)

Benning, R.; Schwärzel, K.; Feger, K. H.

2012-04-01

Regional climate change scenarios for Central Europe predict both an overall increase in temperature and alterations in annual precipitation regimes. For large parts of Central Europe, climate change is expected to result in an increase in winter precipitation and a decrease in summer precipitation. In addition, an increase in extreme conditions, such as heat waves, prolonged drought periods, and heavy rainfall events are predicted. This research examines the potential impacts of increased heavy rainfall events on matter export from small catchment areas, and how different vegetation cover and land management options effects these exports. In order to evaluate the export of matter from different land-use types in the Eastern Ore Mountains (Saxony, NE Germany, 50° 48'18.06" North, 13° 36'24.54" East), study sites were established in three small catchments with homogeneous land-use. These study areas are each sub-catchments of the Ammelsdorf catchment, which provides inflow to the Lehnmühle reservoir (a major water supply for the city of Dresden). Each sub catchment represents one of the three main land-use types in the catchment area of the reservoir: crops (winter oilseed rape, winter wheat), grasslands, and forests (primarily spruce). Since November 2009 the discharge from these sub catchments has been continuously measured and water quality was analyzed on a weekly basis. During peak flow events, discharge was collected using automatic water samplers, which allowed for high temporal resolution analysis of matter export during these periods to be made. During the 2010 and 2011 hydrological years, several heavy rainfall events occurred which have been evaluated. During a 110-hour long precipitation event (P = 170 mm) between 37 and 81 water samples per sub catchment were collected and analyzed. The resulting export of dissolved phosphorus (ortho-PO4-) and dissolved organic carbon (DOC) from the sub catchments during this event is provided in the results. In addition, the matter export resulting from a 59-hour precipitation event (P = 39 mm, between 31 and 48 analyzed water samples per sub catchment) is presented. The contribution of these two events to the annual export of ortho-PO4- and DOC will be discussed.

China's international trade and air pollution in the United States.

PubMed

Lin, Jintai; Pan, Da; Davis, Steven J; Zhang, Qiang; He, Kebin; Wang, Can; Streets, David G; Wuebbles, Donald J; Guan, Dabo

2014-02-04

China is the world's largest emitter of anthropogenic air pollutants, and measurable amounts of Chinese pollution are transported via the atmosphere to other countries, including the United States. However, a large fraction of Chinese emissions is due to manufacture of goods for foreign consumption. Here, we analyze the impacts of trade-related Chinese air pollutant emissions on the global atmospheric environment, linking an economic-emission analysis and atmospheric chemical transport modeling. We find that in 2006, 36% of anthropogenic sulfur dioxide, 27% of nitrogen oxides, 22% of carbon monoxide, and 17% of black carbon emitted in China were associated with production of goods for export. For each of these pollutants, about 21% of export-related Chinese emissions were attributed to China-to-US export. Atmospheric modeling shows that transport of the export-related Chinese pollution contributed 3-10% of annual mean surface sulfate concentrations and 0.5-1.5% of ozone over the western United States in 2006. This Chinese pollution also resulted in one extra day or more of noncompliance with the US ozone standard in 2006 over the Los Angeles area and many regions in the eastern United States. On a daily basis, the export-related Chinese pollution contributed, at a maximum, 12-24% of sulfate concentrations over the western United States. As the United States outsourced manufacturing to China, sulfate pollution in 2006 increased in the western United States but decreased in the eastern United States, reflecting the competing effect between enhanced transport of Chinese pollution and reduced US emissions. Our findings are relevant to international efforts to reduce transboundary air pollution.

Production of giant marine diatoms and their export at oceanic frontal zones: Implications for Si and C flux from stratified oceans

NASA Astrophysics Data System (ADS)

Kemp, A. E. S.; Pearce, R. B.; Grigorov, I.; Rance, J.; Lange, C. B.; Quilty, P.; Salter, I.

2006-12-01

From a synthesis of recent oceanic observations and paleo-data it is evident that certain species of giant diatoms including Rhizosolenia spp. Thalassiothrix spp. and Ethmodiscus rex may become concentrated at oceanic frontal zones and subsequently form episodes of mass flux to the sediment. Within the nutrient bearing waters advecting towards frontal boundaries, these species are generally not dominant, but they appear selectively segregated at fronts, and thus may dominate the export flux. Ancient Thalassiothrix diatom mat deposits in the eastern equatorial Pacific and beneath the Polar Front in the Southern Ocean record the highest open ocean sedimentation rates ever documented and represent vast sinks of silica and carbon. Several of the species involved are adapted to a stratified water column and may thrive in Deep Chlorophyll Maxima. Thus in oceanic regions and/or at times prone to enhanced surface water stratification (e.g., during meltwater pulses) they provide a mechanism for generating substantial biomass at depth and its subsequent export with concomitant implications for Si export and C drawdown. This ecology has important implications for ocean biogeochemical models suggesting that more than one diatom "functional type" should be used. In spite of the importance of these giant diatoms for biogeochemical cycling, their large size coupled with the constraints of conventional oceanographic survey schemes and techniques means that they are undersampled. An improved insight into these key species will be an important prerequisite for enhancing our understanding of marine biogeochemical cycling and for assessing the impacts of climate change on ocean export production.

Measuring the intangibles: a metrics for the economic complexity of countries and products.

PubMed

Cristelli, Matthieu; Gabrielli, Andrea; Tacchella, Andrea; Caldarelli, Guido; Pietronero, Luciano

2013-01-01

We investigate a recent methodology we have proposed to extract valuable information on the competitiveness of countries and complexity of products from trade data. Standard economic theories predict a high level of specialization of countries in specific industrial sectors. However, a direct analysis of the official databases of exported products by all countries shows that the actual situation is very different. Countries commonly considered as developed ones are extremely diversified, exporting a large variety of products from very simple to very complex. At the same time countries generally considered as less developed export only the products also exported by the majority of countries. This situation calls for the introduction of a non-monetary and non-income-based measure for country economy complexity which uncovers the hidden potential for development and growth. The statistical approach we present here consists of coupled non-linear maps relating the competitiveness/fitness of countries to the complexity of their products. The fixed point of this transformation defines a metrics for the fitness of countries and the complexity of products. We argue that the key point to properly extract the economic information is the non-linearity of the map which is necessary to bound the complexity of products by the fitness of the less competitive countries exporting them. We present a detailed comparison of the results of this approach directly with those of the Method of Reflections by Hidalgo and Hausmann, showing the better performance of our method and a more solid economic, scientific and consistent foundation.

Measuring the Intangibles: A Metrics for the Economic Complexity of Countries and Products

PubMed Central

Cristelli, Matthieu; Gabrielli, Andrea; Tacchella, Andrea; Caldarelli, Guido; Pietronero, Luciano

2013-01-01

We investigate a recent methodology we have proposed to extract valuable information on the competitiveness of countries and complexity of products from trade data. Standard economic theories predict a high level of specialization of countries in specific industrial sectors. However, a direct analysis of the official databases of exported products by all countries shows that the actual situation is very different. Countries commonly considered as developed ones are extremely diversified, exporting a large variety of products from very simple to very complex. At the same time countries generally considered as less developed export only the products also exported by the majority of countries. This situation calls for the introduction of a non-monetary and non-income-based measure for country economy complexity which uncovers the hidden potential for development and growth. The statistical approach we present here consists of coupled non-linear maps relating the competitiveness/fitness of countries to the complexity of their products. The fixed point of this transformation defines a metrics for the fitness of countries and the complexity of products. We argue that the key point to properly extract the economic information is the non-linearity of the map which is necessary to bound the complexity of products by the fitness of the less competitive countries exporting them. We present a detailed comparison of the results of this approach directly with those of the Method of Reflections by Hidalgo and Hausmann, showing the better performance of our method and a more solid economic, scientific and consistent foundation. PMID:23940633

ENHANCED: IMPORTING TIMBER, EXPORTING ECOLOGICAL IMPACT

EPA Science Inventory

Covering 32% of the planet, boreal forests are one of the last relatively intact terrestrial biomes, and are a critical carbon sink in global climate dynamics. Mature and old growth boreal forests provide a large number of products that are culturally and economically important, ...

Iran: U.S. Concerns and Policy Responses

DTIC Science & Technology

2010-04-01

family owns large share of Iran’s total pistachio production. President Mahmoud Ahmadinejad Declared reelected on June 12, 2009, and inaugurated...2008) $785 million (trade is severely restricted by U.S. sanctions). Exports to U.S.—$102 million (pomegranate juice, caviar, pistachio nuts

Functioning of the planktonic ecosystem of the Rhone River plume (NW Mediterranean) during spring and its impact on the carbon export: a field data and 3-D modelling combined approach

NASA Astrophysics Data System (ADS)

Auger, P. A.; Diaz, F.; Ulses, C.; Estournel, C.; Neveux, J.; Joux, F.; Pujo-Pay, M.; Naudin, J. J.

2010-12-01

Low-salinity water (LSW, Salinity < 37.5) lenses detached from the Rhone River plume under specific wind conditions tend to favour the biological productivity and potentially a transfer of energy to higher trophic levels on the Gulf of Lions (GoL). A field cruise conducted in May 2006 (BIOPRHOFI) followed some LSW lenses by using a lagrangian strategy. A thorough analysis of the available data set enabled to further improve our understanding of the LSW lenses' functioning and their potential influence on marine ecosystems. Through an innovative 3-D coupled hydrodynamic-biogeochemical modelling approach, a specific calibration dedicated to river plume ecosystems was then proposed and validated on field data. Exploring the role of ecosystems on the particulate organic carbon (POC) export and deposition on the shelf, a sensitivity analysis to the particulate organic matter inputs from the Rhone River was carried out from 1 April to 15 July 2006. Over such a typical end-of-spring period marked by moderate floods, the main deposition area of POC was identified alongshore between 0 and 50 m depth on the GoL, extending the Rhone prodelta to the west towards the exit of the shelf. Moreover, the main deposition area of terrestrial POC was found on the prodelta region, which confirms recent results from sediment data. The averaged daily deposition of particulate organic carbon over the whole GoL is estimated by the model between 40 and 80 mgC/m2, which is in the range of previous secular estimations. The role of ecosystems on the POC export toward sediments or offshore areas was actually highlighted and feedbacks between ecosystems and particulate organic matters are proposed to explain paradoxical model results to the sensitivity test. In fact, the conversion of organic matter in living organisms would increase the retention of organic matter in the food web and this matter transfer along the food web could explain the minor quantity of POC of marine origin observed in the shelf sediments. Thus, the effective carbon deposition on the shelf might be strongly dependent on the zooplankton presence in the GoL. Owing to their fertilizing ability in phosphorus, the LSW lenses could then have indirectly a negative impact on the carbon deposition on the shelf by favouring the development of large phytoplankton fuelling in turn zooplankton communities. The effective carbon deposition would then be delayed out of the GoL, unless a novel transfer of matter occurs toward higher trophic levels further in the open sea through small pelagic fishes.

The Use of LiDAR Elevation Data and Satellite Imagery to Locate Critical Source Areas to Diffuse Pollution in Agricultural Watersheds

NASA Astrophysics Data System (ADS)

Drouin, Ariane; Michaud, Aubert; Thériault, Georges; Beaudin, Isabelle; Rodrigue, Jean-François; Denault, Jean-Thomas; Desjardins, Jacques; Côté, Noémi

2013-04-01

In Quebec / Canada, water quality improvement in rural areas greatly depends on the reduction of diffuse pollution. Indeed, point source pollution has been reduced significantly in Canada in recent years by creating circumscribed pits for manure and removing animals from stream. Diffuse pollution differs from point source pollution because it is spread over large areas. In agricultural areas, sediment loss by soil and riverbank erosion along with loss of nutrients (phosphorus, nitrogen, etc.) and pesticides from fields represent the main source of non-point source pollution. The factor mainly responsible for diffuse pollution in agricultural areas is surface runoff occurring in poorly drained areas in fields. The presence of these poorly drained areas is also one of the most limiting factors in crop productivity. Thus, a reconciliation of objectives at the farm (financial concern for farmers) and off-farm concerns (environmental concern) is possible. In short, drainage, runoff, erosion, water quality and crop production are all interconnected issues that need to be tackled together. Two complementary data sources are mainly used in the diagnosis of drainage, surface runoff and erosion : elevation data and multispectral satellite images. In this study of two watersheds located in Québec (Canada), LiDAR elevation data and satellite imagery (QuickBird, Spot and Landsat) were acquired. The studied territories have been partitioned in hydrologic response units (HRUs) according to sub-basins, soils, elevation (topographic index) and land use. These HRUs are afterwards used in a P index software (P-Edit) that calculates the quantities of sediments and phosphorus exported from each HRUs. These exports of sediments and phosphorus are validated with hydrometric and water quality data obtain in two sub-basins and are also compared to soil brightness index derived from multispectral images. This index is sensitive to soil moisture and thus highlights areas where the soil is more humid. A variety of other indices are used to explain the sediments yields. These indices, such as the average percentage of slope, the distance to the stream, the relative position in landscape, the position to the water table, etc. are mainly derived from high precision elevation data. All these data are used to locate critical source areas that generally correspond to a restraint part of the territory but account for the principal amount of sediments exports. Once the critical source areas are identified, best management practices (BMPs) (per example : contaminant source control practices, conservation cropping practices and surface runoff control structures) can be planned. This way, money and energy are used where it really counts. In this presentation, the complete methodology including LiDAR data processing will be explained. The results and the possibility to reproduce the developed method will be discussed.

Mechanisms and ecological role of carbon transfer within coastal seascapes.

PubMed

Hyndes, Glenn A; Nagelkerken, Ivan; McLeod, Rebecca J; Connolly, Rod M; Lavery, Paul S; Vanderklift, Mathew A

2014-02-01

Worldwide, coastal systems provide some of the most productive habitats, which potentially influence a range of marine and terrestrial ecosystems through the transfer of nutrients and energy. Several reviews have examined aspects of connectivity within coastal seascapes, but the scope of those reviews has been limited to single systems or single vectors. We use the transfer of carbon to examine the processes of connectivity through multiple vectors in multiple ecosystems using four coastal seascapes as case studies. We discuss and compare the main vectors of carbon connecting different ecosystems, and then the natural and human-induced factors that influence the magnitude of effect for those vectors on recipient systems. Vectors of carbon transfer can be grouped into two main categories: detrital particulate organic carbon (POC) and its associated dissolved organic and inorganic carbon (DOC/DIC) that are transported passively; and mobile consumers that transport carbon actively. High proportions of net primary production can be exported over meters to hundreds of kilometers from seagrass beds, algal reefs and mangroves as POC, with its export dependent on wind-generated currents in the first two of these systems and tidal currents for the last. By contrast, saltmarshes export large quantities of DOC through tidal movement, while land run-off plays a critical role in the transport of terrestrial POC and DOC into temperate fjords. Nekton actively transfers carbon across ecosystem boundaries through foraging movements, ontogenetic migrations, or 'trophic relays', into and out of seagrass beds, mangroves or saltmarshes. The magnitude of these vectors is influenced by: the hydrodynamics and geomorphology of the region; the characteristics of the carbon vector, such as their particle size and buoyancy; and for nekton, the extent and frequency of migrations between ecosystems. Through a risk-assessment process, we have identified the most significant human disturbances that affect the integrity of connectivity among ecosystems. Loss of habitat, net primary production (NPP) and overfishing pose the greatest risks to carbon transfer in temperate saltmarsh and tropical estuaries, particularly through their effects on nekton abundance and movement. In comparison, habitat/NPP loss and climate change are likely to be the major risks to carbon transfer in temperate fjords and temperate open coasts through alteration in the amount of POC and/or DOC/DIC being transported. While we have highlighted the importance of these vectors in coastal seascapes, there is limited quantitative data on the effects of these vectors on recipient systems. It is only through quantifying those subsidies that we can effectively incorporate complex interactions into the management of the marine environment and its resources. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

The Production and Export of Bioavailable Iron from Ice Sheets - the Importance of Colloidal and Nanoparticulate Phases

NASA Astrophysics Data System (ADS)

Hawkings, J.; Wadham, J. L.; Tranter, M.; Raiswell, R.; Benning, L. G.; Statham, P. J.; Tedstone, A.; Nienow, P. W.; Telling, J.; Bagshaw, E.

2013-12-01

Glaciers cover approximately 10% of the world's land surface at present, but our knowledge of biogeochemical processes occurring beneath them is still limited, as is our understanding of their impact on downstream ecosystems via the export of nutrients in runoff. Recent work has suggested that glaciers are a primary source of nutrients to near coastal areas(1). For example, macronutrients, such as nitrogen and phosphorus, and micronutrients, such as iron, may support primary production(2,3). Nutrient limitation of primary producers is known to be prevalent in large sectors of the world's oceans and iron is a significant limiting nutrient in Polar waters(4,5). Significantly, large oceanic algal blooms have been observed in polar areas where glacial influence is large(6,7). Our knowledge of iron speciation, concentrations and export dynamics in glacial meltwater is limited due, in part, to problems associated with collecting trace measurements in remote field locations. For example, recent work has indicated large uncertainty in 'dissolved' meltwater iron concentrations (0.2 - 4000 μM(8,9)). There is currently a dearth of information about labile nanoparticulate iron in glacial meltwaters, as well as export dynamics from large ice sheet catchments. Existing research has focused on small catchment examples(8,10), which behave differently to larger catchments(11). Presented here is the first time series of daily variations in meltwater iron concentrations (dissolved, filterable colloidal/nanoparticulate and bioavailable suspended sediment bound) from two large contrasting glacial catchments in Greenland over the 2012 and 2013 summer melt seasons. We also present the first estimates of iron concentrations in Greenlandic icebergs, which have been identified as hot spots of biological activity in the open ocean(12,13). Budgets for ice sheets based on our data demonstrate the importance of glaciers in global nutrient cycles, and reveal a large and previously under-appreciated component of the global iron cycle. References 1 Hood, E. & Scott, D, Nat Geosci 1, 583-587 (2008) 2 Wadham, J. et al., Earth Env Sci T R So (2013) 3 Gerringa, L. J. A. et al., Deep-Sea Res Pt II 71-76, 16-31 (2012) 4 Martin, J. H. & Fitzwater, S. E., Nature 331, 341-343 (1988) 5 Martin, J. H., Fitzwater, S. E. & Gordon, R. M., Global Biogeochem Cy 4, 5-12 (1990) 6 Perrette, M., Yool, A., Quartly, G. D. & Popova, E. E., Biogeosciences 8, 515-524 (2011) 7 Frajka-Williams, E. & Rhines, P. B., Deep-Sea Res Pt I 57, 541-552 (2010) 8 Statham, P. J., Skidmore, M. & Tranter, M., Global Biogeochem Cy 22 (2008) 9 Mikucki, J. A. et al., Science 324, 397-400 (2009) 10 Bhatia, M. P. et al., Nat Geosci (2013) 11 Wadham, J. L. et al., Global Biogeochem Cy 24 (2010) 12 Smith, K. L. et al., Science 317, 478-482 (2007) 13 Raiswell, R. & Canfield, D. E., Geochemical Perspectives 1, 1-220 (2012)

River Export of Dissolved and Particulate Organic Carbon from Permafrost and Peat Deposits across the Siberian Arctic

NASA Astrophysics Data System (ADS)

Wild, B.; Andersson, A.; Bröder, L.; Vonk, J.; Hugelius, G.; McClelland, J. W.; Raymond, P. A.; Gustafsson, O.

2017-12-01

Permafrost and peat deposits of northern high latitudes store more than 1300 Pg of organic carbon. This carbon has been preserved for thousands of years by cold and moist conditions, but is now increasingly mobilized as temperatures rise. While part will be degraded to CO2 and CH4 and amplify global warming, part will be exported by rivers to the Arctic Ocean where it can be degraded or re-buried by sedimentation. We here use the four large Siberian rivers Ob, Yenisey, Lena, and Kolyma as natural integrators of carbon mobilization in their catchments. We apply isotope based source apportionments and Markov Chain Monte Carlo Simulations to quantify contributions of organic carbon from permafrost and peat deposits to organic carbon exported by these rivers. More specifically, we compare the 14C signatures of dissolved and particulate organic carbon (DOC, POC) sampled close to the river mouths with those of five potential carbon sources; (1) recent aquatic and (2) terrestrial primary production, (3) the active layer of permafrost soils, (4) deep Holocene deposits (including thermokarst and peat deposits) and (5) Ice Complex Deposits. 14C signatures of these endmembers were constrained based on extensive literature review. We estimate that the four rivers together exported 2.4-4.5 Tg organic carbon from permafrost and peat deposits per year. While total organic carbon export was dominated by DOC (90%), the export of organic carbon from permafrost and peat deposits was more equally distributed between DOC (56%) and POC (44%). Recent models predict that ca. 200 Pg carbon will be lost as CO2 or CH4 by 2100 (RCP8.5) from the circumarctic permafrost area, of which roughly a quarter is drained by the Ob, Yenisey, Lena, and Kolyma rivers. Our comparatively low estimates of river carbon export thus suggest limited transfer of organic carbon from permafrost and peat deposits to high latitude rivers, or its rapid degradation within rivers. Our findings highlight the importance of both DOC and POC, and its degradation, for the fate of carbon mobilized from high latitude deposits under global warming, and indicate a low potential for its stabilization in the Arctic Ocean.

Organic carbon fluxes in the Atlantic and the Southern Ocean: relationship to primary production compiled from satellite radiometer data

NASA Astrophysics Data System (ADS)

Fischer, G.; Ratmeyer, V.; Wefer, G.

Fluxes of organic carbon normalised to a depth of 1000 m from 18 sites in the Atlantic and the Southern Ocean are presented, comprising nine biogeochemical provinces as defined by Longhurst et al. (1995. Journal of Plankton Research 17, 1245-1271). For comparison with primary production, we used a recent compilation of primary production values derived from CZCS data (Antoine et al., 1996. Global Biogeochemical Cycles 10, 57-69). In most cases, the seasonal patterns stood reasonably well in accordance with the carbon fluxes. Particularly, organic carbon flux records from two coastal sites off northwest and southwest Africa displayed a more distinct correlation to the primary production in sectors (1×1°) which are situated closer to the coastal environments. This was primarily caused by large upwelling filaments streaming far offshore, resulting in a cross-shelf carbon transport. With respect to primary production, organic carbon export to a water depth of 1000 m, and the fraction of primary production exported to a depth of 1000 m (export fraction=EF 1000), we were able to distinguish between: (1) the coastal environments with highest values (EF 1000=1.75-2.0%), (2) the eastern equatorial upwelling area with moderately high values (EF 1000=0.8-1.1%), (3) and the subtropical oligotrophic gyres that yielded lowest values (EF 1000=0.6%). Carbon export in the Southern Ocean was low to moderate, and the EF 1000 value seems to be quite low in general. Annual organic carbon fluxes were proportional to primary production, and the export fraction EF 1000 increased with primary production up to 350 gC m -2 yr-1. Latitudinal variations in primary production were reflected in the carbon flux pattern. A high temporal variability of primary production rates and a pronounced seasonality of carbon export were observed in the polar environments, in particular in coastal domains, although primary production (according to Antoine et al., 1996. Global Biogeochemical Cycles 10, 57-69), carbon fluxes, and the export fraction remained at low.

Anthropogenic and climatic controls on carbon and nitrogen exports from Mississippi river basin to Gulf of Mexico during 1800 - 2100: Implications for hypoxia and ocean acidification

NASA Astrophysics Data System (ADS)

Tian, H.; Yang, J.; Zhang, B.; Pan, S.; Lohrenz, S. E.; Cai, W. J.; He, R.; Xue, Z. G.; Lu, C.; Ren, W.; Huang, W. J.; Yao, Y.

2016-02-01

The enlarged size of dead zone in the Gulf of Mexico in 2015, resulting from high summer precipitation and nutrient runoff from agriculture and other human activities in Mississippi river basin, has aroused plenty of scientific attentions and public concerns. Although recent-decade patterns of water/carbon/nitrogen exports from the US land to Gulf of Mexico have been intensively investigated through gauge station monitoring and empirical-based modeling, our understanding of its historical and future long-term trends and the underlying mechanisms is still limited. Climate variability and change, land cover/land use change (e.g., cropland shift from eastern US to Midwest US) and evolving land management practices (e.g., nitrogen fertilizer use in corn belt) are all important drivers regulating interannual, decadal and century-long variability in riverine carbon and nitrogen exports. In this study, we explore river discharge and carbon/nitrogen exports from US drainage basins in a 300-year period covering both historical and future eras (1800 - 2100) and further quantify the contributions of climate, land use, nitrogen fertilizer use, and atmospheric chemistry by using a process-based land ecosystem model (DLEM) with networked river system incorporated. The results indicate that spatial distribution and shift of agricultural land is of critical importance in shaping land-to-aquatic mass flow and coastal water quality. Historical pattern and future scenarios of climate variability and change play an important role in the trend of water yield and enhanced inter-annual variations of river discharge and carbon/nitrogen exports. Atmospheric nitrogen deposition and agricultural nitrogen fertilizer uses in land ecosystem largely contributed to land-to-aquatic nitrogen exports. Our sensitivity analyses with DLEM suggest that precipitation in the basin as well as nitrogen fertilizer use in US corn belt are important determinants of nutrient export and hence the size of dead zone in the Gulf of Mexico. These findings imply that we need to consider both climate and anthropogenic changes taking place in land ecosystems for better developing land management strategies in mitigating hypoxia and ocean acidification.

Dynamics of Phosphorus export from small forested catchments in low mountain ranges in Germany

NASA Astrophysics Data System (ADS)

Julich, Stefan; Julich, Dorit; Benning, Raphael; Feger, Karl-Heinz

2017-04-01

Phosphorus (P) plays an important role in the nutrition of forest ecosystem. The transport of P in forest soils predominantly occurs along preferential water flow pathways bypassing large parts of the soil matrix. Therefore, rapid flow processes by preferential flow and/or during storm events may lead to significant P losses from forest soils. However only little knowledge about the dynamics, magnitude and driving processes of P exports into surface water exist. In this contribution, we present the results of two studies where two small forested catchments have been monitored for a period around 3 years. Both catchments are situated in low mountain ranges in Saxony (catchment size 21 ha) and Thuringia (catchment size 5 ha) representing medium P contents in the topsoil of 1142 mg kg-1 and 834 mg kg-1 respectively. During the regular sampling (monthly to weekly sampling frequency), the mean Total-P concentrations of 23 μg L-1(Thuringian Site) and 8 μg L-1(Saxonian Site) have been measured. However, during single storm events Total-P concentrations increased considerably with maximum concentrations of 134 μg L-1(Thuringian Site) and 203 μg L-1(Saxonian Site). Our findings indicate that during storm events, especially after longer dry periods, significant amounts of phosphorus can be exported from forest ecosystems. Comparison of discharge-concentration patterns of Total-P, Nitrogen and DOC, as well as dye tracer experiments, suggest that preferential flow along biopores and stone surfaces, and the interface between mineral soil and litter layer are main pathways of export from forests. For the site in Saxony we calculated mean annual export rates of 32.8 to 33.5 g ha-1 a-1 based on the weekly sampling with different load calculation methods (flow weighted methods up to linear regression models). If the events are included into the annual load calculation the mean annual export fluxes increase from 47.8 to 58.6 g ha-1 a-1 based on the different load calculation methods. This implies that the estimation of P-exports from forested catchments need to be based on appropriate monitoring schemes and load estimation methods.

Shifts in stream hydrochemistry in responses to typhoon and non-typhoon precipitation

NASA Astrophysics Data System (ADS)

Chang, Chung-Te; Huang, -Chuan, Jr.; Wang, Lixin; Shih, Yu-Ting; Lin, Teng-Chiu

2018-04-01

Climate change is projected to increase the intensity and frequency of extreme climatic events such as tropical cyclones. However, few studies have examined the responses of hydrochemical processes to climate extremes. To fill this knowledge gap, we compared the relationship between stream discharge and ion input-output budget during typhoon and non-typhoon periods in four subtropical mountain watersheds with different levels of agricultural land cover in northern Taiwan. The results indicated that the high predictability of ion input-output budgets using stream discharge during the non-typhoon period largely disappeared during the typhoon periods. For ions such as Na+, NH4+, and PO43-, the typhoon period and non-typhoon period exhibited opposite discharge-budget relationships. In other cases, the discharge-budget relationship was driven by the typhoon period, which consisted of only 7 % of the total time period. The striking differences in the discharge-ion budget relationship between the two periods likely resulted from differences in the relative contributions of surface runoff, subsurface runoff and groundwater, which had different chemical compositions, to stream discharge between the two periods. Watersheds with a 17-22 % tea plantation cover showed large increases in NO3- export with increases in stream discharge. In contrast, watersheds with 93-99 % forest cover showed very mild or no increases in NO3- export with increases in discharge and very low levels of NO3- export even during typhoon storms. The results suggest that even mild disruption of the natural vegetation could largely alter hydrochemical processes. Our study clearly illustrates significant shifts in hydrochemical responses between regular and typhoon precipitation. We propose that hydrological models should separate hydrochemical processes into regular and extreme conditions to better capture the whole spectrum of hydrochemical responses to a variety of climate conditions.

Carbon export in the naturally iron-fertilized Kerguelen area of the Southern Ocean based on the 234Th approach

NASA Astrophysics Data System (ADS)

Planchon, F.; Ballas, D.; Cavagna, A.-J.; Bowie, A. R.; Davies, D.; Trull, T.; Laurenceau-Cornec, E. C.; Van Der Merwe, P.; Dehairs, F.

2015-06-01

This study examined upper-ocean particulate organic carbon (POC) export using the 234Th approach as part of the second KErguelen Ocean and Plateau compared Study expedition (KEOPS2). Our aim was to characterize the spatial and the temporal variability of POC export during austral spring (October-November 2011) in the Fe-fertilized area of the Kerguelen Plateau region. POC export fluxes were estimated at high productivity sites over and downstream of the plateau and compared to a high-nutrient low-chlorophyll (HNLC) area upstream of the plateau in order to assess the impact of iron-induced productivity on the vertical export of carbon. Deficits in 234Th activities were observed at all stations in surface waters, indicating early scavenging by particles in austral spring. 234Th export was lowest at the reference station R-2 and highest in the recirculation region (E stations) where a pseudo-Lagrangian survey was conducted. In comparison 234Th export over the central plateau and north of the polar front (PF) was relatively limited throughout the survey. However, the 234Th results support that Fe fertilization increased particle export in all iron-fertilized waters. The impact was greatest in the recirculation feature (3-4 fold at 200 m depth, relative to the reference station), but more moderate over the central Kerguelen Plateau and in the northern plume of the Kerguelen bloom (~2-fold at 200 m depth). The C : Th ratio of large (>53 μm) potentially sinking particles collected via sequential filtration using in situ pumping (ISP) systems was used to convert the 234Th flux into a POC export flux. The C : Th ratios of sinking particles were highly variable (3.1 ± 0.1 to 10.5 ± 0.2 μmol dpm-1) with no clear site-related trend, despite the variety of ecosystem responses in the fertilized regions. C : Th ratios showed a decreasing trend between 100 and 200 m depth suggesting preferential carbon loss relative to 234Th possibly due to heterotrophic degradation and/or grazing activity. C : Th ratios of sinking particles sampled with drifting sediment traps in most cases showed very good agreement with ratios for particles collected via ISP deployments (>53 μm particles). Carbon export production varied between 3.5 ± 0.9 and 11.8 ± 1.3 mmol m-2 d-1 from the upper 100 m and between 1.8 ± 0.9 and 8.2 ± 0.9 mmol m-2 d-1 from the upper 200 m. The highest export production was found inside the PF meander with a range of 5.3 ± 1.0 to 11.8 ± 1.1 mmol m-2 d-1 over the 19-day survey period. The impact of Fe fertilization is highest inside the PF meander with 2.9-4.5-fold higher carbon flux at 200 m depth in comparison to the HNLC control station. The impact of Fe fertilization was significantly less over the central plateau (stations A3 and E-4W) and in the northern branch of the bloom (station F-L) with 1.6-2.0-fold higher carbon flux compared to the reference station R. Export efficiencies (ratio of export to primary production and ratio of export to new production) were particularly variable with relatively high values in the recirculation feature (6 to 27 %, respectively) and low values (1 to 5 %, respectively) over the central plateau (station A3) and north of the PF (station F-L), indicating spring biomass accumulation. Comparison with KEOPS1 results indicated that carbon export production is much lower during the onset of the bloom in austral spring than during the peak and declining phases in late summer.

Carbon export in the naturally iron-fertilized Kerguelen area of the Southern Ocean based on the 234Th approach

NASA Astrophysics Data System (ADS)

Planchon, F.; Ballas, D.; Cavagna, A.-J.; Bowie, A. R.; Davies, D.; Trull, T.; Laurenceau, E.; Van Der Merwe, P.; Dehairs, F.

2014-11-01

The Kerguelen Plateau region in the Indian sector of the Southern Ocean supports annually a large-scale phytoplankton bloom which is naturally fertilized with iron. As part of the second KErguelen Ocean and Plateau compared Study expedition (KEOPS2) in austral spring (October-November 2011), we examined upper-ocean Particulate Organic Carbon (POC) export using the 234Th approach. We aimed at characterizing the spatial and the temporal variability of POC export production at high productivity sites over and downstream the Kerguelen plateau. Export production is compared to a High Nutrient Low Chlorophyll area upstream of the plateau in order to assess the impact of iron-induced productivity on the vertical export of carbon. Deficits in 234Th activities relative to its parent nuclide 238U were observed at all stations in surface waters, indicating that scavenging by particles occurred during the early stages of the phytoplankton bloom. 234Th export was lowest at reference station R-2 (412 ± 134 dpm m-2 d-1) and highest inside a~permanent meander of the Polar Front (PF) at stations E (1995 ± 176 dpm m-2 d-1, second visit E-3) where a detailed time series was obtained as part of a~pseudo-lagrangian study. 234Th export over the central plateau was relatively limited at station A3 early (776 ± 171 dpm m-2 d-1, first visit A3-1) and late in the survey (993 ± 223 dpm m-2 d-1, second visit A3-2), but it was higher at high biomass stations TNS-8 (1372 ± 255 dpm m-2 d-1) and E-4W (1068 ± 208 dpm m-2 d-1) in waters which could be considered as derived from plateau. Limited 234Th export of 973 ± 207 dpm m-2 d-1 was also found in the northern branch of the Kerguelen bloom located downstream of the island, north of the PF (station F-L). The 234Th results support that Fe fertilization increased particle export in all iron fertilized waters. The impact was greatest in the recirculation feature (3-4 fold at 200 m depth), but more moderate over the central Kerguelen plateau and in the northern plume of the Kerguelen bloom (∼2-fold at 200 m depth). The C : Th ratio of large (> 53 μm) potentially sinking particles collected via sequential filtration using in situ pumping (ISP) systems were used to convert the 234Th flux into a POC export flux. The C : Th ratios of sinking particles were highly variable (range: 3.1 ± 0.1-10.5 ± 0.2 μmol dpm-1) with no clear site related trend, despite the variety of ecosystem responses in the fertilized regions. C : Th ratios showed a decreasing trend between 100 and 200 m depth suggesting preferential loss of carbon relative to 234Th possibly due to heterotrophic degradation and/or grazing activity. Comparison of the C : Th ratios within sinking particles obtained with the drifting sediment traps showed in most cases very good agreement to those collected via ISP deployments (> 53 μm particles). Carbon export production varied between 3.5 ± 0.9 mmol m-2 d-1 and 11.8 ± 1.3 mmol m-2 d-1 from the upper 100 m and between 1.8 ± 0.9 mmol m-2 d-1 and 8.2 ± 0.9 mmol m-2 d-1 from the upper 200 m. Highest export production was found inside the PF meander with a range of 5.4 ± 0.7 mmol m-2 d-1 to 11.8 ± 1.1 mmol m-2 d-1 at 100 m depth decreasing to 5.3 ± 1.0 mmol m-2 d-1 to 8.2 ± 0.8 mmol m-2 d-1 at 200 m depth over the 19 day survey period. The impact of Fe fertilization is highest inside the PF meander with 2.9- up to 4.5-fold higher carbon flux at 200 m depth in comparison to the HNLC control station. The impact of Fe fertilization was significantly less over the central plateau (stations A3 and E-4W) and in the northern branch of the bloom (station F-L) with 1.6- up to 2.0-fold higher carbon flux compared to the reference station R. Export efficiencies (ratio of export to primary production) were particularly variable with relatively high values in the recirculation feature (6-27%) and low values (1-5%) over the central plateau (station A3) and north of the PF (station F-L) indicating spring biomass accumulation. Comparison with KEOPS1 results indicated that carbon export production is much lower during the onset of the bloom in austral spring in comparison to the peak and declining phase in late summer.

EVALUATING THE ACCOTINK CREEK RESTORATION PROJECT FOR IMPROVING WATER QUALITY, IN-STREAM HABITAT, AND BANK STABILITY

EPA Science Inventory

Increased urbanization results in a larger percentage of connected impervious areas and can contribute large quantities of stormwater runoff and significant quantities of debris and pollutants (e.g., litter, oils, microorganisms, sediments, nutrients, organic matter, and heavy me...

Big Sugar in southern Africa: rural development and the perverted potential of sugar/ethanol exports.

PubMed

Richardson, Ben

2010-01-01

This paper asks how investment in large-scale sugar cane production has contributed, and will contribute, to rural development in southern Africa. Taking a case study of the South African company Illovo in Zambia, the argument is made that the potential for greater tax revenue, domestic competition, access to resources and wealth distribution from sugar/ethanol production have all been perverted and with relatively little payoff in wage labour opportunities in return. If the benefits of agro-exports cannot be so easily assumed, then the prospective 'balance sheet' of biofuels needs to be re-examined. In this light, the paper advocates smaller-scale agrarian initiatives.

The production of multiprotein complexes in insect cells using the baculovirus expression system.

PubMed

Abdulrahman, Wassim; Radu, Laura; Garzoni, Frederic; Kolesnikova, Olga; Gupta, Kapil; Osz-Papai, Judit; Berger, Imre; Poterszman, Arnaud

2015-01-01

The production of a homogeneous protein sample in sufficient quantities is an essential prerequisite not only for structural investigations but represents also a rate-limiting step for many functional studies. In the cell, a large fraction of eukaryotic proteins exists as large multicomponent assemblies with many subunits, which act in concert to catalyze specific activities. Many of these complexes cannot be obtained from endogenous source material, so recombinant expression and reconstitution are then required to overcome this bottleneck. This chapter describes current strategies and protocols for the efficient production of multiprotein complexes in large quantities and of high quality, using the baculovirus/insect cell expression system.

The plasma separation process as a pre-cursor for large scale radioisotope production

NASA Astrophysics Data System (ADS)

Stevenson, Nigel R.

2001-07-01

Radioisotope production generally employs either accelerators or reactors to convert stable (usually enriched) isotopes into the desired product species. Radioisotopes have applications in industry, environmental sciences, and most significantly in medicine. The production of many potentially useful radioisotopes is significantly hindered by the lack of availability or by the high cost of key enriched stable isotopes. To try and meet this demand, certain niche enrichment processes have been developed and commercialized. Calutrons, centrifuges, and laser separation processes are some of the devices and techniques being employed to produce large quantities of selective enriched stable isotopes. Nevertheless, the list of enriched stable isotopes in sufficient quantities remains rather limited and this continues to restrict the availability of many radioisotopes that otherwise could have a significant impact on society. The Plasma Separation Process is a newly available commercial technique for producing large quantities of a wide range of enriched isotopes and thereby holds promise of being able to open the door to producing new and exciting applications of radioisotopes in the future.

Rapid Ovary Mass-Isolation (ROMi) to Obtain Large Quantities of Drosophila Egg Chambers for Fluorescent In Situ Hybridization.

PubMed

Jambor, Helena; Mejstrik, Pavel; Tomancak, Pavel

2016-01-01

Isolation of large quantities of tissue from organisms is essential for many techniques such as genome-wide screens and biochemistry. However, obtaining large quantities of tissues or cells is often the rate-limiting step when working in vivo. Here, we present a rapid method that allows the isolation of intact, single egg chambers at various developmental stages from ovaries of adult female Drosophila flies. The isolated egg chambers are amenable for a variety of procedures such as fluorescent in situ hybridization, RNA isolation, extract preparation, or immunostaining. Isolation of egg chambers from adult flies can be completed in 5 min and results, depending on the input amount of flies, in several milliliters of material. The isolated egg chambers are then further processed depending on the exact requirements of the subsequent application. We describe high-throughput in situ hybridization in 96-well plates as example application for the mass-isolated egg chambers.

A synthesis and comparative evaluation of drainage water management

USDA-ARS?s Scientific Manuscript database

Viable large-scale crop production in the United States requires artificial drainage in humid and poorly drained agricultural regions. Excess water removal is generally achieved by installing tile drains that export water to open ditches that eventually flow into streams. Drainage water management...

My Morning Coffee: The Effect of Climate Change on the Economies of Coffee-Producing Countries

NASA Astrophysics Data System (ADS)

Shilling, K.; Brauman, K. A.

2012-12-01

Through its effect on export crops, climate change will have important effects on economic systems and government capacity in sub-Saharan Africa. We show that climate change effects on three important export crops - coffee, cocoa and cotton - will undermine large portions of the economy, not just the rural farmers who grow these crops. Our analysis is based high-resolution data on crop location, temperature, and water requirements in conjunction with new projections for temperature increases and precipitation changes in sub-Saharan Africa. Our focus on export crops is distinct from most work on the effects of climate change on agriculture, which often focuses on subsistence and food crops. We posit that substantial and important effects on the economy and political systems will come from negative impacts on cash crops, which underpin many economies in sub-Saharan Africa. For instance, 3% of cropland in Uganda (and 2% in Ethiopia) is used for coffee production and over 3.5 million households are involved in the sector; by contrast, 7% of cropland in Uganda (and 11% in Ethiopia) is used for maize, which contributes much less to the formal economy. The relationship between the value of coffee exported and government revenue illustrates the importance of coffee to political and economic stability. A drop in the export value of coffee by 10% in Uganda will drive government revenue down by 20%, and while there is uncertainty around the exact impact of climate change, it is likely that production will take a turn for the worse. We use these factors to assess reliance of select country's economy on these crops, from the farmer to the exporter; the sensitivity of the crops to variation in the climate; and the subsequent impact on government capacity. Our research illustrates how strongly the impacts of climate change are linked to economic and political structures.

A probabilistic assessment of calcium carbonate export and dissolution in the modern ocean

NASA Astrophysics Data System (ADS)

Battaglia, Gianna; Steinacher, Marco; Joos, Fortunat

2016-05-01

The marine cycle of calcium carbonate (CaCO3) is an important element of the carbon cycle and co-governs the distribution of carbon and alkalinity within the ocean. However, CaCO3 export fluxes and mechanisms governing CaCO3 dissolution are highly uncertain. We present an observationally constrained, probabilistic assessment of the global and regional CaCO3 budgets. Parameters governing pelagic CaCO3 export fluxes and dissolution rates are sampled using a Monte Carlo scheme to construct a 1000-member ensemble with the Bern3D ocean model. Ensemble results are constrained by comparing simulated and observation-based fields of excess dissolved calcium carbonate (TA*). The minerals calcite and aragonite are modelled explicitly and ocean-sediment fluxes are considered. For local dissolution rates, either a strong or a weak dependency on CaCO3 saturation is assumed. In addition, there is the option to have saturation-independent dissolution above the saturation horizon. The median (and 68 % confidence interval) of the constrained model ensemble for global biogenic CaCO3 export is 0.90 (0.72-1.05) Gt C yr-1, that is within the lower half of previously published estimates (0.4-1.8 Gt C yr-1). The spatial pattern of CaCO3 export is broadly consistent with earlier assessments. Export is large in the Southern Ocean, the tropical Indo-Pacific, the northern Pacific and relatively small in the Atlantic. The constrained results are robust across a range of diapycnal mixing coefficients and, thus, ocean circulation strengths. Modelled ocean circulation and transport timescales for the different set-ups were further evaluated with CFC11 and radiocarbon observations. Parameters and mechanisms governing dissolution are hardly constrained by either the TA* data or the current compilation of CaCO3 flux measurements such that model realisations with and without saturation-dependent dissolution achieve skill. We suggest applying saturation-independent dissolution rates in Earth system models to minimise computational costs.

Quantity, Revisited: An Object-Oriented Reusable Class

NASA Technical Reports Server (NTRS)

Funston, Monica Gayle; Gerstle, Walter; Panthaki, Malcolm

1998-01-01

"Quantity", a prototype implementation of an object-oriented class, was developed for two reasons: to help engineers and scientists manipulate the many types of quantities encountered during routine analysis, and to create a reusable software component to for large domain-specific applications. From being used as a stand-alone application to being incorporated into an existing computational mechanics toolkit, "Quantity" appears to be a useful and powerful object. "Quantity" has been designed to maintain the full engineering meaning of values with respect to units and coordinate systems. A value is a scalar, vector, tensor, or matrix, each of which is composed of Value Components, each of which may be an integer, floating point number, fuzzy number, etc., and its associated physical unit. Operations such as coordinate transformation and arithmetic operations are handled by member functions of "Quantity". The prototype has successfully tested such characteristics as maintaining a numeric value, an associated unit, and an annotation. In this paper we further explore the design of "Quantity", with particular attention to coordinate systems.

Variability and Maintenance of Turbulence in the Very Stable Boundary Layer

NASA Astrophysics Data System (ADS)

Mahrt, Larry

2010-04-01

The relationship of turbulence quantities to mean flow quantities, such as the Richardson number, degenerates substantially for strong stability, at least in those studies that do not place restrictions on minimum turbulence or non-stationarity. This study examines the large variability of the turbulence for very stable conditions by analyzing four months of turbulence data from a site with short grass. Brief comparisons are made with three additional sites, one over short grass on flat terrain and two with tall vegetation in complex terrain. For very stable conditions, any dependence of the turbulence quantities on the mean wind speed or bulk Richardson number becomes masked by large scatter, as found in some previous studies. The large variability of the turbulence quantities is due to random variations and other physical influences not represented by the bulk Richardson number. There is no critical Richardson number above which the turbulence vanishes. For very stable conditions, the record-averaged vertical velocity variance and the drag coefficient increase with the strength of the submeso motions (wave motions, solitary waves, horizontal modes and numerous more complex signatures). The submeso motions are on time scales of minutes and not normally considered part of the mean flow. The generation of turbulence by such unpredictable motions appears to preclude universal similarity theory for predicting the surface stress for very stable conditions. Large variation of the stress direction with respect to the wind direction for the very stable regime is also examined. Needed additional work is noted.

EVALUATING THE ACCOTINK CREEK URBAN STREAM RESTORATION PROJECT FOR IMPROVING WATER QUALITY, IN-STREAM HABITAT, AND BANK STABILITY

EPA Science Inventory

Increased urbanization results in a larger percentage of connected impervious areas and can contribute large quantities of stormwater runoff and significant quantities of debris and pollutants (e.g., litter, oils, microorganisms, sediments, nutrients, organic matter, and heavy me...

Influence of pre-injection control parameters on main-injection fuel quantity for an electronically controlled double-valve fuel injection system of diesel engine

NASA Astrophysics Data System (ADS)

Song, Enzhe; Fan, Liyun; Chen, Chao; Dong, Quan; Ma, Xiuzhen; Bai, Yun

2013-09-01

A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment. The accuracy of the model is validated through comparison with experimental data. The influence of pre-injection control parameters on main-injection quantity under different control modes is analyzed. In the spill control valve mode, main-injection fuel quantity decreases gradually and then reaches a stable level because of the increase in multi-injection dwell time. In the needle control valve mode, main-injection fuel quantity increases with rising multi-injection dwell time; this effect becomes more obvious at high-speed revolutions and large main-injection pulse widths. Pre-injection pulse width has no obvious influence on main-injection quantity under the two control modes; the variation in main-injection quantity is in the range of 1 mm3.

Do Social Conditions Affect Capuchin Monkeys' (Cebus apella) Choices in a Quantity Judgment Task?

PubMed

Beran, Michael J; Perdue, Bonnie M; Parrish, Audrey E; Evans, Theodore A

2012-01-01

Beran et al. (2012) reported that capuchin monkeys closely matched the performance of humans in a quantity judgment test in which information was incomplete but a judgment still had to be made. In each test session, subjects first made quantity judgments between two known options. Then, they made choices where only one option was visible. Both humans and capuchin monkeys were guided by past outcomes, as they shifted from selecting a known option to selecting an unknown option at the point at which the known option went from being more than the average rate of return to less than the average rate of return from earlier choices in the test session. Here, we expanded this assessment of what guides quantity judgment choice behavior in the face of incomplete information to include manipulations to the unselected quantity. We manipulated the unchosen set in two ways: first, we showed the monkeys what they did not get (the unchosen set), anticipating that "losses" would weigh heavily on subsequent trials in which the same known quantity was presented. Second, we sometimes gave the unchosen set to another monkey, anticipating that this social manipulation might influence the risk-taking responses of the focal monkey when faced with incomplete information. However, neither manipulation caused difficulty for the monkeys who instead continued to use the rational strategy of choosing known sets when they were as large as or larger than the average rate of return in the session, and choosing the unknown (riskier) set when the known set was not sufficiently large. As in past experiments, this was true across a variety of daily ranges of quantities, indicating that monkeys were not using some absolute quantity as a threshold for selecting (or not) the known set, but instead continued to use the daily average rate of return to determine when to choose the known versus the unknown quantity.

7 CFR 1493.470 - Evidence of export.

Code of Federal Regulations, 2012 CFR

2012-01-01

... OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Supplier Credit Guarantee... provide CCC an evidence of export report for each shipment made under the payment guarantee. This report... participation in any of the following CCC or USDA export program: Export Enhancement Program, Dairy Export...

7 CFR 1493.470 - Evidence of export.

Code of Federal Regulations, 2014 CFR

2014-01-01

... OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Supplier Credit Guarantee... provide CCC an evidence of export report for each shipment made under the payment guarantee. This report... participation in any of the following CCC or USDA export program: Export Enhancement Program, Dairy Export...

7 CFR 1493.470 - Evidence of export.

Code of Federal Regulations, 2013 CFR

2013-01-01

... OF AGRICULTURE EXPORT PROGRAMS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Supplier Credit Guarantee... provide CCC an evidence of export report for each shipment made under the payment guarantee. This report... participation in any of the following CCC or USDA export program: Export Enhancement Program, Dairy Export...

Nebulization Reflux Concentrator

NASA Technical Reports Server (NTRS)

Cofer, Wesley R., III; Collins, V. G.

1986-01-01

Nebulization reflux concentrator extracts and concentrates trace quantities of water-soluble gases for subsequent chemical analysis. Hydrophobic membrane and nebulizing nozzles form scrubber for removing trace quantities of soluble gases or other contaminants from atmosphere. Although hydrophobic membrane virtually blocks all transport of droplets, it offers little resistance to gas flow; hence, device permits relatively large volumes of gas scrubbed efficiently with very small volumes of liquid. This means analyzable quantities of contaminants concentrate in extracting solutions in much shorter times than with conventional techniques.

Molecular cloning, expression and purification of L-amino acid oxidase from the Malayan pit viper Calloselasma rhodostoma.

PubMed

Kommoju, Phaneeswara Rao; Macheroux, Peter; Ghisla, Sandro

2007-03-01

A cDNA encoding LAAO from the Malayan pit viper (Calloselasma rhodostoma) was cloned into an expression vector of the methylotropic yeast Pichia pastoris. The LAAO open reading frame was inserted after the alpha-MF-signal sequence. Upon induction soluble and active LAAO is produced and exported into the culture supernatant at a concentration of up to 0.4 mg/L. Recombinant LAAO was purified from this by ion exchange and molecular sieve chromatography to yield apparently homogeneous protein in quantities of approximately 0.25 mg/L growth medium. Expressed LAAO exhibits the same electrophoretic mobility as native LAAO (62 kDa) and exhibits approximately the same extent of glycosylation as authentic LAAO from snake venom. Catalytic properties and substrate specificity of recombinant LAAO are similar to those of native enzyme.

7 CFR 1493.470 - Evidence of export.

Code of Federal Regulations, 2011 CFR

2011-01-01

... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC... exporter is required to provide CCC an evidence of export report for each shipment made under the payment... participation in any of the following CCC or USDA export program: Export Enhancement Program, Dairy Export...

7 CFR 1493.80 - Evidence of export.

Code of Federal Regulations, 2011 CFR

2011-01-01

... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS CCC EXPORT CREDIT GUARANTEE PROGRAMS CCC Export Credit Guarantee Program (GSM-102) and CCC Intermediate Export Credit Guarantee Program (GSM-103) Operations § 1493.80 Evidence of export. (a) Report of export. The exporter is required to provide CCC an...

Quantifying the Role of Agriculture and Urbanization in the Nitrogen Cycle across Texas

NASA Astrophysics Data System (ADS)

Helper, L. C.; Yang, Z.

2011-12-01

Over-enrichment of nutrients throughout coastal areas has been a growing problem as population growth has enhanced agricultural and industrial processes. Enhanced nitrogen (N) fluxes from land to coast continue to be the result of over fertilization and pollution deposition. This over-enrichment of nutrients has led to eutrophication and hypoxic conditions in coastal environments. Global estimates indicate rivers export 48 Tg N yr -1 to coastal zones, and regionally North America exports 7.2 Tg N yr-1. These exports are primarily from anthropogenic N inputs (Boyer et al. 2006). Currently the U.S. is home to the second largest hypoxic zone in the world, the Mississippi River Basin, and previous work from Howarth et al. (2002) suggest much of the over enrichment of N is a result of agricultural practices. Aforementioned work has focused on global and large regional estimates; however an inventory has not been conducted on the full scope of N sources along the Gulf of Mexico. This study was conducted along the Gulf, through the state of Texas, in order to quantify all sources of N in a region which contains a large precipitation gradient, three major metropolitan areas, and one of the top livestock industries in the United States. Nitrogen inputs from fertilizer, livestock, and crop fixation were accounted for and totaled to be 0.91 Tg N for the year of 2007. Using estimates of leaching rates from Howarth et al. (2002), riverine export of N was at a minimum of 0.18 Tg for that year. Atmospheric deposition inputs were also analyzed using the Weather Research and Forecasting model with online chemistry (WRF-Chem) and were found to be significantly smaller than those of agriculture. The developed regional high-resolution gridded N budget is now available to be used as N input to next-generation land surface models for nutrient leaching and riverine transport modeling. Ultimately, this comprehensive dataset will help better understand the full pathways of anthropogenic influences on coastal systems.

Interprovincial transfer of embodied energy between the Jing-Jin-Ji area and other provinces in China: A quantification using interprovincial input-output model.

PubMed

Chen, Weiming; Wu, Sanmang; Lei, Yalin; Li, Shantong

2017-04-15

Commodity trade between regions implies a large amount of energy transfer. As an important economic growth pole of China, the Jing-Jin-Ji area (Beijing-Tianjin-Hebei) is also one of the areas with the largest energy consumption in China. Moreover, the primary energy consumer goods in this area are fossil fuels, such as coal. This has led to serious air pollution in the area. Therefore, the reduction of energy consumption under the premise of maintaining sustained economic growth is an important task of the Jing-Jin-Ji area. In this study, an interprovincial input-output model was applied to quantitatively estimate the embodied energy transfer between Jing-Jin-Ji area and other provinces in China. The results indicated that the Metal and nonmetal mineral processing industry and the Electrical, gas and water industry in the Jing-Jin-Ji area exported a large amount of embodied energy to the Yangtze River Delta and the Pearl River Delta. However, the embodied energy export of the Jing-Jin-Ji area mainly exported by Hebei province. Beijing and Tianjin even have some net import of embodied energy. The embodied energy transfer between Tianjin, Hebei and other provinces was mainly driven by investment, while the main media of embodied energy transfer between Beijing and other provinces was consumption. Therefore, we suggest that the Jing-Jin-Ji area should further increase the degree of dependence on other provinces' energy-intensive products and reduce the export of energy-intensive products. In addition, there should be difference in the energy and industrial policies among Beijing, Tianjin and Hebei, and the problems of high energy consumption and high proportion of heavy industry in Hebei should be first resolved. Copyright © 2017 Elsevier B.V. All rights reserved.

Interactions between reactive nitrogen and the Canadian landscape: A budget approach

NASA Astrophysics Data System (ADS)

Clair, Thomas A.; Pelletier, Nathan; Bittman, Shabtai; Leip, Adrian; Arp, Paul; Moran, Michael D.; Dennis, Ian; Niemi, David; Sterling, Shannon; Drury, Craig F.; Yang, Jingyi

2014-11-01

The movement of excess reactive nitrogen (Nr) from anthropogenic activities to natural ecosystems has been described as one of the most serious environmental threats facing modern society. One of the approaches for tracking this movement is the use of budgets that quantify fluxes. We constructed an Nr budget for Canada using measured and modeled values from the scientific literature, government databases, and data from new agri-environmental indicators, in order to produce information for policy makers and scientists to understand the major flows of nitrogen to allow a better assessment of risks to the Canadian environment. We divided the Canadian territory south of 60°N into areas dominated by natural ecosystems, as well as by agricultural and urban/industrial activities to evaluate Nr flows within, between, and out of these units. We show that Canada is a major exporter of Nr due to the availability of inexpensive commercial fertilizers. The large land area suitable for agriculture makes Canada a significant agricultural Nr exporter of both grain crops and livestock. Finally, Canada exports petroleum N mainly to the United States. Because of its location and prevailing atmospheric transport patterns, Canada is a net receptor of Nr air pollution from the United States, receiving approximately 20% of the Nr leaving the U.S. airshed. We found that overall, terrestrial natural ecosystems as well as the atmosphere are in balance between Nr inputs and outputs when all N reactive and nonreactive fluxes are included. However, when only reactive forms are considered, almost 50% of N entering the Canadian atmosphere cannot be accounted for and is assumed to be lost to the Atlantic and Arctic oceans or to unmeasured dry deposition. However, agricultural and freshwater landscapes are showing large differences between measured inputs and outputs of N as our data suggest that denitrification in soils and aquatic systems is larger than what models predict. Our work also shows that Canada is a major contributor to the global flow of nitrogen through commercial exports.

Sources of methylmercury to a wetland-dominated lake in northern Wisconsin.

PubMed

Watras, C J; Morrison, K A; Kent, A; Price, N; Regnell, O; Eckley, C; Hintelmann, H; Hubacher, T

2005-07-01

Several lines of evidence suggest that wetlands may be a major source of methylmercury (MeHg) to receiving waters, perhaps explaining the strong correlation between concentrations of waterborne MeHg and dissolved organic carbon (DOC) in regions such as northern Wisconsin. We evaluated the relative importance of wetland export in the MeHg budget of a wetland-dominated lake in northern Wisconsin using mass balance. Channelized runoff from a large headwater wetland was the major source of water and total mercury (HgT) to the lake during the study period. The wetland also exported MeHg in high concentrations (0.2-0.8 ng L(-1)), resulting in an export rate similar to those reported for other northern wetlands (ca. 0.3 microg MeHg m(-2) y(-1)). Yet, based on intensive sampling during 2002, the mass of MeHg that accumulated in the lake during summer was an order of magnitude greater than the export of MeHg from the wetland to the lake. Hence, a large in-lake source of MeHg is inferred from the mass balance. Most of the accumulated MeHg built-up in anoxic hypolimnetic waters; and the build-up was roughly balanced by losses of inorganic Hg (Hg(II)) implying a chemical transformation within the anoxic water column. An abundance of sulfate-reducing bacteria (SRB) in hypolimnetic waters, established by DNA analysis of the pelagic microbial community, along with a previous report documenting high methylation rates in the hypolimnion of this lake (ca. 10% d(-1)), suggest that this transformation was microbially mediated. These findings indicate that the direct effect of wetland runoff may be outweighed by indirect effects on the lacustrine MeHg cycle, enhancing the load of Hg(II), the activity of SRB, and the retention of MeHg, especially in northern lakes with flushing times longer than six months.

Iran: U.S. Concerns and Policy Responses

DTIC Science & Technology

2010-05-24

during 1981-89 and President 1989-1997. One of Iran’s richest men, family owns large share of Iran’s total pistachio production. President Mahmoud...sanctions). Exports to U.S.—$102 million (pomegranate juice, caviar, pistachio nuts, carpets, medicines, artwork). Imports from U.S.—$683 million

Measuring Dependence on Imported Oil

EIA Publications

1995-01-01

U.S. dependence on imported oil can be measured in at least two ways. The differences hinge largely on whether oil imports are defined as net imports (total imports minus exports) or as total imports. EIA introduces a revised table that expresses dependence on imports in terms of both measures.

Aquatic export of young dissolved and gaseous carbon from a pristine boreal fen: Implications for peat carbon stock stability.

PubMed

Campeau, Audrey; Bishop, Kevin H; Billett, Michael F; Garnett, Mark H; Laudon, Hjalmar; Leach, Jason A; Nilsson, Mats B; Öquist, Mats G; Wallin, Marcus B

2017-12-01

The stability of northern peatland's carbon (C) store under changing climate is of major concern for the global C cycle. The aquatic export of C from boreal peatlands is recognized as both a critical pathway for the remobilization of peat C stocks as well as a major component of the net ecosystem C balance (NECB). Here, we present a full year characterization of radiocarbon content ( 14 C) of dissolved organic carbon (DOC), carbon dioxide (CO 2 ), and methane (CH 4 ) exported from a boreal peatland catchment coupled with 14 C characterization of the catchment's peat profile of the same C species. The age of aquatic C in runoff varied little throughout the year and appeared to be sustained by recently fixed C from the atmosphere (<60 years), despite stream DOC, CO 2 , and CH 4 primarily being sourced from deep peat horizons (2-4 m) near the mire's outlet. In fact, the 14 C content of DOC, CO 2 , and CH 4 across the entire peat profile was considerably enriched with postbomb C compared with the solid peat material. Overall, our results demonstrate little to no mobilization of ancient C stocks from this boreal peatland and a relatively large resilience of the source of aquatic C export to forecasted hydroclimatic changes. © 2017 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

Iron defecation by sperm whales stimulates carbon export in the Southern Ocean

PubMed Central

Lavery, Trish J.; Roudnew, Ben; Gill, Peter; Seymour, Justin; Seuront, Laurent; Johnson, Genevieve; Mitchell, James G.; Smetacek, Victor

2010-01-01

The iron-limited Southern Ocean plays an important role in regulating atmospheric CO2 levels. Marine mammal respiration has been proposed to decrease the efficiency of the Southern Ocean biological pump by returning photosynthetically fixed carbon to the atmosphere. Here, we show that by consuming prey at depth and defecating iron-rich liquid faeces into the photic zone, sperm whales (Physeter macrocephalus) instead stimulate new primary production and carbon export to the deep ocean. We estimate that Southern Ocean sperm whales defecate 50 tonnes of iron into the photic zone each year. Molar ratios of Cexport ∶Feadded determined during natural ocean fertilization events are used to estimate the amount of carbon exported to the deep ocean in response to the iron defecated by sperm whales. We find that Southern Ocean sperm whales stimulate the export of 4 × 105 tonnes of carbon per year to the deep ocean and respire only 2 × 105 tonnes of carbon per year. By enhancing new primary production, the populations of 12 000 sperm whales in the Southern Ocean act as a carbon sink, removing 2 × 105 tonnes more carbon from the atmosphere than they add during respiration. The ability of the Southern Ocean to act as a carbon sink may have been diminished by large-scale removal of sperm whales during industrial whaling. PMID:20554546

Export of dissolved carbonaceous and nitrogenous substances in rivers of the "Water Tower of Asia".

PubMed

Qu, Bin; Sillanpää, Mika; Kang, Shichang; Yan, Fangping; Li, Zhiguo; Zhang, Hongbo; Li, Chaoliu

2018-03-01

Rivers are critical links in the carbon and nitrogen cycle in aquatic, terrestrial, and atmospheric environments. Here riverine carbon and nitrogen exports in nine large rivers on the Tibetan Plateau - the "Water Tower of Asia" - were investigated in the monsoon season from 2013 to 2015. Compared with the world average, concentrations of dissolved inorganic carbon (DIC, 30.7mg/L) were high in river basins of the plateau due to extensive topographic relief and intensive water erosion. Low concentrations of dissolved organic carbon (DOC, 1.16mg/L) were likely due to the low temperature and unproductive land vegetation environments. Average concentrations of riverine DIN (0.32mg/L) and DON (0.35 mg/L) on the Tibetan Plateau were close to the world average. However, despite its predominantly pristine environment, discharge from agricultural activities and urban areas of the plateau has raised riverine N export. In addition, DOC/DON ratio (C/N, ~6.5) in rivers of the Tibetan Plateau was much lower than the global average, indicating that dissolved organic carbon in the rivers of this region might be more bioavailable. Therefore, along with global warming and anthropogenic activities, increasing export of bioavailable riverine carbon and nitrogen from rivers of the Tibetan Plateau can be expected in the future, which will possibly influence the regional carbon and nitrogen cycle. Copyright © 2017. Published by Elsevier B.V.

Case studies in international tobacco surveillance: cigarette smuggling in Brazil.

PubMed

Shafey, O; Cokkinides, V; Cavalcante, T M; Teixeira, M; Vianna, C; Thun, M

2002-09-01

This article is the first in a series of international case studies developed by the American Cancer Society to illustrate use of publicly available surveillance data for regional tobacco control. A descriptive analysis of Brazil and Paraguay cigarette production and trade data from official sources. Per capita cigarette consumption for Brazil and its neighbour was calculated from 1970 to 1998 using data on production, imports, and exports from NATIONS, the National Tobacco Information Online System. A 63% decrease was observed in the estimate of per capita consumption of cigarettes in Brazil between 1986 and 1998 (from 1913 cigarettes per person in 1986 to 714 cigarettes per person in 1998) and a 16-fold increase in Paraguay was observed during the same period (from 678 cigarettes per person in 1986 to 10 929 cigarettes per person in 1998). Following Brazil's 1999 passage of a 150% cigarette export tax, cigarette exports fell 89% and Brazil's estimated per capita consumption rose to 1990 levels (based on preliminary data). Per capita consumption in Paraguay also fell to 1990 levels. These trends coincide with local evidence that large volumes of cigarettes manufactured in Brazil for export to Paraguay are smuggled back and consumed as tax-free contraband in Brazil. It is hoped that this case study will draw wider public attention to the problems that smuggling presents for tobacco control, help identify other countries confronting similar issues, and stimulate effective interventions.

Selenium Characterization in the Global Rice Supply Chain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Paul N.; Lombi, Enzo; Sun, Guo-Xin

2009-08-13

For up to 1 billion people worldwide, insufficient dietary intake of selenium (Se) is a serious health constraint. Cereals are the dominant Se source for those on low protein diets, as typified by the global malnourished population. With crop Se content constrained largely by underlying geology, regional soil Se variations are often mirrored by their locally grown staples. Despite this, the Se concentrations of much of the world's rice, the mainstay of so many, is poorly characterized, for both total Se content and Se speciation. In this study, 1092 samples of market sourced polished rice were obtained. The sampled ricemore » encompassed dominant rice producing and exporting countries. Rice from the U.S. and India were found to be the most enriched, while mean average levels were lowest in Egyptian rice: {approx}32-fold less than their North American equivalents. By weighting country averages by contribution to either global production or export, modeled baseline values for both were produced. Based on a daily rice consumption of 300 g day{sup -1}, around 75% of the grains from the production and export pools would fail to provide 70% of daily recommended Se intakes. Furthermore, Se localization and speciation characterization using X-ray fluorescence ({mu}-XRF) and X-ray absorption near edge structure ({mu}-XANES) techniques were investigated in a Se-rich sample. The results revealed that the large majority of Se in the endosperm was present in organic forms.« less

Air-Parcel Residence Times Within Forest Canopies

NASA Astrophysics Data System (ADS)

Gerken, Tobias; Chamecki, Marcelo; Fuentes, Jose D.

2017-10-01

We present a theoretical model, based on a simple model of turbulent diffusion and first-order chemical kinetics, to determine air-parcel residence times and the out-of-canopy export of reactive gases emitted within forest canopies under neutral conditions. Theoretical predictions of the air-parcel residence time are compared to values derived from large-eddy simulation for a range of canopy architectures and turbulence levels under neutral stratification. Median air-parcel residence times range from a few sec in the upper canopy to approximately 30 min near the ground and the distribution of residence times is skewed towards longer times in the lower canopy. While the predicted probability density functions from the theoretical model and large-eddy simulation are in good agreement with each other, the theoretical model requires only information on canopy height and eddy diffusivities inside the canopy. The eddy-diffusivity model developed additionally requires the friction velocity at canopy top and a parametrized profile of the standard deviation of vertical velocity. The theoretical model of air-parcel residence times is extended to include first-order chemical reactions over a range of of Damköhler numbers ( Da) characteristic of plant-emitted hydrocarbons. The resulting out-of-canopy export fractions range from near 1 for Da =10^{-3} to less than 0.3 at Da = 10. These results highlight the necessity for dense and tall forests to include the impacts of air-parcel residence times when calculating the out-of-canopy export fraction for reactive trace gases.

Late summer particulate organic carbon export and twilight zone remineralisation in the Atlantic sector of the Southern Ocean

NASA Astrophysics Data System (ADS)

Planchon, F.; Cavagna, A.-J.; Cardinal, D.; André, L.; Dehairs, F.

2013-02-01

As part of the GEOTRACES Bonus-GoodHope (BGH) expedition (January-March 2008) in the Atlantic sector of the Southern Ocean, particulate organic carbon (POC) export was examined from the surface to the mesopelagic twilight zone using water column distributions of total 234Th and biogenic particulate Ba (Baxs). Surface POC export production was estimated from steady state and non steady state modelling of 234Th fluxes, which were converted into POC fluxes, using the POC/234Th ratio of large, potentially sinking particles (> 53 μm) collected via in situ pumps. Deficits in 234Th activities were observed at all stations from the surface to the bottom of the mixed layer, yielding 234Th export fluxes from the upper 100 m of 496 ± 214 dpm m-2 d-1 to 1195 ± 158 dpm m-2 d-1 for the steady state model and of 149 ±517 dpm m-2 d-1 to 1217 ± 231 dpm m-2 d-1 for the non steady state model. Using the POC/234Thp ratio of sinking particles (ratios varied from 1.7 ± 0.2 μmol dpm-1 to 4.8 ± 1.9 μmol dpm-1) POC export production at 100 m was calculated to range between 0.9 ± 0.4 and 5.1 ± 2.1 mmol C m-2 d-1,assuming steady state and between 0.3 ± 0.9 m-2 d-1 and 4.9 ± 3.3 mmol C m-2 d-1, assuming non steady state. From the comparison of both approaches, it appears that during late summer export decreased by 56 to 16% for the area between the sub-Antarctic zone and the southern Antarctic Circumpolar Current Front (SACCF), whereas it remained rather constant over time in the HNLC area south of the SACCF. POC export represented only 6 to 54% of new production, indicating that export efficiency was, in general, low, except in the vicinity of the SACCF, where export represented 56% of new production. Attenuation of the POC sinking flux in the upper mesopelagic waters (100-600 m depth interval) was evidenced both, from excess 234Th activities and from particulate biogenic Ba (Baxs) accumulation. Excess 234Th activities, reflected by 234Th/238U ratios as large as 1.21 ± 0.05, are attributed to remineralisation/disaggregation of 234Th-bearing particles. The accumulation of excess 234Th in the 100-600 m depth interval ranged from 458 ± 633 dpm m-2 d-1 to 3068 ± 897 dpm m-2 d-1, assuming steady state. Using the POC/234Thp ratio of sinking particles (> 53 μm), this 234Th accumulation flux was converted into a POC remineralisation flux which ranged between 0.9 ± 1.2 mmol C m-2 d-1 and 9.2 ± 2.9 mmol C m-2 d-1. Mesopelagic particulate biogenic Ba has been reported to reflect bacterial degradation of organic matter and to be related to oxygen consumption and bacterial carbon respiration. We observed that the highest Baxs contents (reaching up to > 1000 pM), in general, occurred between 200 and 400 m. Depth-weighted average mesopelagic Baxs (meso-Baxs) values were converted into respired C fluxes, which ranged between 0.23 and 6.4 mmol C m-2 d-1, in good agreement with 234Th-based remineralisation fluxes. A major outcome from this study is the observed significant positive correlation between POC remineralisation as estimated from meso-Baxs contents and from 234Th excess (R2 = 0.73; excluding 2 outliers). Remineralisation of POC in the twilight zone was particularly efficient relative to POC export resulting in negligible bathypelagic (> 600 m) POC export fluxes in the sub-Antarctic zone, the Polar Front zone and the northern Weddell Gyre, while the subtropical zone as well as the vicinity of the SACCF had significant deep POC fluxes.

Whole-Genome Sequences of Listeria monocytogenes Sequence Type 6 Isolates Associated with a Large Foodborne Outbreak in South Africa, 2017 to 2018

PubMed Central

Tau, Nomsa; Smouse, Shannon L.; Mtshali, Phillip S.; Mnyameni, Florah; Khumalo, Zamantungwa T. H.; Ismail, Arshad; Govender, Nevashan; Thomas, Juno

2018-01-01

ABSTRACT We report whole-genome sequences for 10 Listeria monocytogenes sequence type 6 isolates associated with a large listeriosis outbreak in South Africa, which occurred over the period of 2017 to 2018. The possibility of listeriosis spreading beyond South Africa’s borders as a result of exported contaminated food products prompted us to make the genome sequences publicly available. PMID:29930052

An assessment of potential weather effects due to operation of the Space Orbiting Light Augmentation Reflector Energy System (SOLARES)

NASA Technical Reports Server (NTRS)

Allen, N. C.

1978-01-01

Implementation of SOLARES will input large quantities of heat continuously into a stationary location on the Earth's surface. The quantity of heat released by each of the SOlARES ground receivers, having a reflector orbit height of 6378 km, exceeds by 30 times that released by large power parks which were studied in detail. Using atmospheric models, estimates are presented for the local weather effects, the synoptic scale effects, and the global scale effects from such intense thermal radiation.

Sensitivity analysis of a sediment dynamics model applied in a Mediterranean river basin: global change and management implications.

PubMed

Sánchez-Canales, M; López-Benito, A; Acuña, V; Ziv, G; Hamel, P; Chaplin-Kramer, R; Elorza, F J

2015-01-01

Climate change and land-use change are major factors influencing sediment dynamics. Models can be used to better understand sediment production and retention by the landscape, although their interpretation is limited by large uncertainties, including model parameter uncertainties. The uncertainties related to parameter selection may be significant and need to be quantified to improve model interpretation for watershed management. In this study, we performed a sensitivity analysis of the InVEST (Integrated Valuation of Environmental Services and Tradeoffs) sediment retention model in order to determine which model parameters had the greatest influence on model outputs, and therefore require special attention during calibration. The estimation of the sediment loads in this model is based on the Universal Soil Loss Equation (USLE). The sensitivity analysis was performed in the Llobregat basin (NE Iberian Peninsula) for exported and retained sediment, which support two different ecosystem service benefits (avoided reservoir sedimentation and improved water quality). Our analysis identified the model parameters related to the natural environment as the most influential for sediment export and retention. Accordingly, small changes in variables such as the magnitude and frequency of extreme rainfall events could cause major changes in sediment dynamics, demonstrating the sensitivity of these dynamics to climate change in Mediterranean basins. Parameters directly related to human activities and decisions (such as cover management factor, C) were also influential, especially for sediment exported. The importance of these human-related parameters in the sediment export process suggests that mitigation measures have the potential to at least partially ameliorate climate-change driven changes in sediment exportation. Copyright © 2014 Elsevier B.V. All rights reserved.

China’s international trade and air pollution in the United States

PubMed Central

Lin, Jintai; Pan, Da; Davis, Steven J.; Zhang, Qiang; He, Kebin; Wang, Can; Streets, David G.; Wuebbles, Donald J.; Guan, Dabo

2014-01-01

China is the world’s largest emitter of anthropogenic air pollutants, and measurable amounts of Chinese pollution are transported via the atmosphere to other countries, including the United States. However, a large fraction of Chinese emissions is due to manufacture of goods for foreign consumption. Here, we analyze the impacts of trade-related Chinese air pollutant emissions on the global atmospheric environment, linking an economic-emission analysis and atmospheric chemical transport modeling. We find that in 2006, 36% of anthropogenic sulfur dioxide, 27% of nitrogen oxides, 22% of carbon monoxide, and 17% of black carbon emitted in China were associated with production of goods for export. For each of these pollutants, about 21% of export-related Chinese emissions were attributed to China-to-US export. Atmospheric modeling shows that transport of the export-related Chinese pollution contributed 3–10% of annual mean surface sulfate concentrations and 0.5–1.5% of ozone over the western United States in 2006. This Chinese pollution also resulted in one extra day or more of noncompliance with the US ozone standard in 2006 over the Los Angeles area and many regions in the eastern United States. On a daily basis, the export-related Chinese pollution contributed, at a maximum, 12–24% of sulfate concentrations over the western United States. As the United States outsourced manufacturing to China, sulfate pollution in 2006 increased in the western United States but decreased in the eastern United States, reflecting the competing effect between enhanced transport of Chinese pollution and reduced US emissions. Our findings are relevant to international efforts to reduce transboundary air pollution. PMID:24449863

Shift in performance of food safety management systems in supply chains: case of green bean chain in Kenya versus hot pepper chain in Uganda.

PubMed

Nanyunja, Jessica; Jacxsens, Liesbeth; Kirezieva, Klementina; Kaaya, Archileo N; Uyttendaele, Mieke; Luning, Pieternel A

2016-08-01

This study investigates the level of design and operation of food safety management systems (FSMS) of farmers and export traders in Kenya and Uganda. FSMS diagnostic tools developed for the fresh produce chain were used to assess the levels of context riskiness, FSMS activities and system output in primary production (n = 60) and trade (n = 60). High-risk context characteristics combined with basic FSMS are expected to increase the risk on unsafe produce. In Uganda both farmers and export traders of hot peppers operate in a high- to moderate-risk context but have basic FSMS and low systems output. In Kenya, both farmers and export traders of green beans operate in a low- to moderate-risk context. The farmers have average performing FSMS, whereas export trade companies showed more advanced FSMS and system output scores ranging from satisfactory to good. Large retailers supplying the EU premium market play a crucial role in demanding compliance with strict voluntary food safety standards, which was reflected in the more advanced FSMS and good system output in Kenya, especially traders. In Kenya, a clear shift in more fit-for-purpose FSMS and higher system output was noticed between farms and trade companies. In the case of Uganda, traders commonly supply to the less demanding EU wholesale markets such as ethnic specialty shops. They only have to comply with the legal phytosanitary and pesticide residue requirements for export activities, which apparently resulted in basic FSMS and low system output present with both farmers and traders. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.