WorldWideScience

Sample records for include bayhead delta

  1. Constraining Holocene Evolution of Shelf Bayhead Delta Deposits Offshore Mississippi, USA

    Science.gov (United States)

    Hollis, R. J.; Wallace, D. J.; Miner, M. D.

    2017-12-01

    The slowly subsiding inner shelf of Mississippi-Alabama (MS-AL) has a complex network of Late Quaternary paleofluvial and deltaic deposits driven by fluctuating sea levels. Since the Last Glacial Maximum, sea-level rise (SLR) has lead to transgressive reworking of these lithosomes. In rare instances, typically when the rate of relative sea-level rise was particularly rapid or sediment supply was high, these deposits are preserved. Results from studies in Texas and Alabama suggest bayhead deltas (or upper-estuarine units) backstepped kilometers landward in response to periods of rapid sea-level rise (i.e. 9.8-9.5 ka, 8.9-8.5 ka, 8.4-8.0 ka, 7.9-7.5 ka, and 7.4-6.8 ka). Bayhead delta backstepping depends on relative SLR rates, accommodation space, shelf slope, wave climate and sediment supply. While at least one preserved bayhead delta deposit has been identified on the inner shelf of MS-AL, the flooding and abandonment chronology is currently unknown. The previously quantified sandy bayhead delta deposit (>100.4 x106 m3) is roughly twice the combined volume of the subaerial Petit Bois barrier island, located two miles to the north, and the three western offshore shelf sand shoals (55.9 x106 m3). The sediment supply needed for the shoal's genesis requires further exploration and likely has many contributors, but transgressive ravinement of the sandy bayhead delta seems like a logical source. This study builds on previous work that has extensively mapped the stratigraphy of the eastern MS-AL inner shelf using geophysical and core data by adding a robust number of radiocarbon ages and macro-/micro- faunal analysis from new cores as a proxy for depositional environments. This source-to-sink approach helps to detail the evolution of ancient Pascagoula/Escatawpa, La Batre and Fowl paleo rivers, and their roles in the formation of the large inner shelf, shore-oblique shoals as well as Petit Bois Island. Correlating the new ages with previously published high-resolution sea

  2. Natural and Human-Induced Variations in Accretion of the Roanoke Bay-head Delta

    Science.gov (United States)

    Jalowska, A.; McKee, B. A.; Rodriguez, A. B.

    2014-12-01

    Bay-head deltas (BHD), along with their adjacent floodplains serve as storage sites for lithogenic and organic material on millennial time scales and are biogeochemically active sites on daily to decadal time scales, contributing to global nutrient and carbon cycles. BHD host unique, highly diverse ecosystems such as the pristine swamp forest and hardwood bottomlands, of the Lower Roanoke River, NC. The global value of ecosystem services provided by wetlands within natural BHD is 2.5 to 2.8 mln 2007$/km2/year. BHD are very sensitive to changes in sedimentation and to changes in the rate of sea-level rise. Core descriptions, 14C geo-chronologies and grain-size analyses show that the Roanoke BHD in North Carolina, USA experienced two episodes of retreat in late Holocene. The first event occurred around ca 3500 cal. yr. BC and is recognized as a prominent flooding surface separating the delta plain environment, below, from interdistributary bay, above. Across the flooding surface rates of sediment accumulation decreased from 1.8-3.3 mm/year to 0.5-0.6 mm/year. That change was associated with increased sediment accommodation. Sedimentation rates were keeping up with the low rates of sea-level rise until 1600-1700 AD. During that time, the delta started to rapidly accrete and the interdistributary bay was buried with delta plain and prodelta sediment. This occurred in response to the low rates of sea-level rise at that time (-0.1 to 0.47 mm/year) and the release of large quantities of sediments associated with the initiation of agriculture by European settlers in the drainage basin. The second episode of retreat was initiated during the 19th century when the rate of sea-level rose to 2.1 mm/year. During that time, agricultural practices improved, decreasing the amount of sediments delivered to the mouth of the Roanoke River. Under these conditions, the delta started backstepping. Analyses of historical maps, aerial photography, and side-scan sonar data show that between

  3. 75 FR 20386 - Auburn Hosiery Mills, Inc., Currently Known as Delta Galil, Including On-Site Leased Workers From...

    Science.gov (United States)

    2010-04-19

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-71,321] Auburn Hosiery Mills, Inc... Auburn Hosiery Mills, Inc., including on-site leased workers from Quality Personnel, Auburn, Kentucky... related to apparel. Information shows that Auburn Hosiery Mills was merged into its parent company, Delta...

  4. The Inconvenient Truth of Fresh Sediment: Insights from a New Method for Quantifying Subsidence in the Mississippi Delta

    Science.gov (United States)

    Chamberlain, E. L.; Shen, Z.; Tornqvist, T. E.; Kim, W.

    2017-12-01

    Knowing the rates and drivers of subsidence in deltas is essential to coastal management. There is a growing consensus that relatively shallow processes such as compaction and artificial drainage are primary contributors to subsidence, although deeper processes such as faulting may be locally important. Here we present a new method to quantify subsidence of a 6000 km2 relict bayhead delta of the Mississippi Delta, using the depth of the mouthbar-overbank stratigraphic boundary that formed near the low tide level in combination with OSL chronology. The contributions of isostatic processes are removed by subtracting a relative sea-level rise term previously obtained from basal peat. We find that displacement rates of the boundary, averaged over 750 to 1500 years, are on the order of a few mm/yr. Cumulative displacement is strongly correlated to overburden thickness, decreases coastward coincident with thinning of the bayhead delta deposit, and appears unrelated to the thickness of underlying Holocene strata or the occurrence of previously mapped faults. This supports compaction of shallow strata as a dominant driver of subsidence in the Mississippi Delta. We find that at least 50% of elevation gained through overbank deposition is ultimately lost to subsidence, significantly greater than the 35% loss previously estimated for inland localities underlain by peat. Our results demonstrate that bayhead deltas are especially vulnerable to subsidence. This finding has major relevance to coastal restoration in the Mississippi Delta through engineered river-sediment diversions. While inactive regions of the delta may be fairly stable if not perturbed by humans, the introduction of fresh sediment to the delta plain will inevitably accelerate subsidence. Values obtained with our method will be applied to a delta growth model that predicts the land-building potential of river-sediment diversions discharging into open bays under realistic scenarios of load-driven subsidence.

  5. Evaluation of the Repeatability of the Delta Q Duct Leakage Testing TechniqueIncluding Investigation of Robust Analysis Techniques and Estimates of Weather Induced Uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Dickerhoff, Darryl; Walker, Iain

    2008-08-01

    found in for the pressure station approach. Walker and Dickerhoff also included estimates of DeltaQ test repeatability based on the results of field tests where two houses were tested multiple times. The two houses were quite leaky (20-25 Air Changes per Hour at 50Pa (0.2 in. water) (ACH50)) and were located in the San Francisco Bay area. One house was tested on a calm day and the other on a very windy day. Results were also presented for two additional houses that were tested by other researchers in Minneapolis, MN and Madison, WI, that had very tight envelopes (1.8 and 2.5 ACH50). These tight houses had internal duct systems and were tested without operating the central blower--sometimes referred to as control tests. The standard deviations between the multiple tests for all four houses were found to be about 1% of the envelope air flow at 50 Pa (0.2 in. water) (Q50) that led to the suggestion of this as a rule of thumb for estimating DeltaQ uncertainty. Because DeltaQ is based on measuring envelope air flows it makes sense for uncertainty to scale with envelope leakage. However, these tests were on a limited data set and one of the objectives of the current study is to increase the number of tested houses. This study focuses on answering two questions: (1) What is the uncertainty associated with changes in weather (primarily wind) conditions during DeltaQ testing? (2) How can these uncertainties be reduced? The first question is addressing issues of repeatability. To study this five houses were tested as many times as possible over a day. Weather data was recorded on-site--including the local windspeed. The result from these five houses were combined with the two Bay Area homes from the previous studies. The variability of the tests (represented by the standard deviation) is the repeatability of the test method for that house under the prevailing weather conditions. Because the testing was performed over a day a wide range of wind speeds was achieved following

  6. Delta Dynamics

    DEFF Research Database (Denmark)

    Bendixen, Mette

    . The warming air temperature affects the soil temperature and permafrost thaws and destabilizes the material in the coastal zone. In Greenland, the warming temperature lowers the surface mass balance of the Greenland Ice Sheet and more material is transported to the coastal zone. The sea ice extent is thinning...... of a fjord and the second type is a wider fan-shaped open delta. Most deltas are directly coupled to the Greenland Ice Sheet or local icecaps and are highly influenced by the dynamics in the catchments. It is demonstrated how a modern changing climate directly affects delta dynamics, and that Greenlandic...... deltas are prograding, contrary to the global trend showing eroding Arctic coasts. Moreover, it is revealed that the increasing proglacial freshwater runoff, caused by a lowering of the surface mass balance of the Greenland Ice Sheet is the main determining agent in delta progradation. The final part...

  7. DELTAS: A new Global Delta Sustainability Initiative (Invited)

    Science.gov (United States)

    Foufoula-Georgiou, E.

    2013-12-01

    Deltas are economic and environmental hotspots, food baskets for many nations, home to a large part of the world population, and hosts of exceptional biodiversity and rich ecosystems. Deltas, being at the land-water interface, are international, regional, and local transport hubs, thus providing the basis for intense economic activities. Yet, deltas are deteriorating at an alarming rate as 'victims' of human actions (e.g. water and sediment reduction due to upstream basin development), climatic impacts (e.g. sea level rise and flooding from rivers and intense tropical storms), and local exploration (e.g. sand or aggregates, groundwater and hydrocarbon extraction). Although many efforts exist on individual deltas around the world, a comprehensive global delta sustainability initiative that promotes awareness, science integration, data and knowledge sharing, and development of decision support tools for an effective dialogue between scientists, managers and policy makers is lacking. Recently, the international scientific community proposed to establish the International Year of Deltas (IYD) to serve as the beginning of such a Global Delta Sustainability Initiative. The IYD was proposed as a year to: (1) increase awareness and attention to the value and vulnerability of deltas worldwide; (2) promote and enhance international and regional cooperation at the scientific, policy, and stakeholder level; and (3) serve as a launching pad for a 10-year committed effort to understand deltas as complex socio-ecological systems and ensure preparedness in protecting and restoring them in a rapidly changing environment. In this talk, the vision for such an international coordinated effort on delta sustainability will be presented as developed by a large number of international experts and recently funded through the Belmont Forum International Opportunities Fund. Participating countries include: U.S., France, Germany, U.K., India, Japan, Netherlands, Norway, Brazil, Bangladesh

  8. Future Change to Tide-Influenced Deltas

    Science.gov (United States)

    Nienhuis, Jaap H.; Hoitink, A. J. F. (Ton); Törnqvist, Torbjörn E.

    2018-04-01

    Tides tend to widen deltaic channels and shape delta morphology. Here we present a predictive approach to assess a priori the effect of fluvial discharge and tides on deltaic channels. We show that downstream channel widening can be quantified by the ratio of the tide-driven discharge and the fluvial discharge, along with a second metric representing flow velocities. A test of our new theory on a selection of 72 deltas globally shows good correspondence to a wide range of environments, including wave-dominated deltas, river-dominated deltas, and alluvial estuaries. By quantitatively relating tides and fluvial discharge to delta morphology, we offer a first-order prediction of deltaic change that may be expected from altered delta hydrology. For example, we expect that reduced fluvial discharge in response to dam construction will lead to increased tidal intrusion followed by enhanced tide-driven sediment import into deltas, with implications for navigation and other human needs.

  9. Migration in Deltas: An Integrated Analysis

    Science.gov (United States)

    Nicholls, Robert J.; Hutton, Craig W.; Lazar, Attila; Adger, W. Neil; Allan, Andrew; Arto, Inaki; Vincent, Katharine; Rahman, Munsur; Salehin, Mashfiqus; Sugata, Hazra; Ghosh, Tuhin; Codjoe, Sam; Appeaning-Addo, Kwasi

    2017-04-01

    Deltas and low-lying coastal regions have long been perceived as vulnerable to global sea-level rise, with the potential for mass displacement of exposed populations. The assumption of mass displacement of populations in deltas requires a comprehensive reassessment in the light of present and future migration in deltas, including the potential role of adaptation to influence these decisions. At present, deltas are subject to multiple drivers of environmental change and often have high population densities as they are accessible and productive ecosystems. Climate change, catchment management, subsidence and land cover change drive environmental change across all deltas. Populations in deltas are also highly mobile, with significant urbanization trends and the growth of large cities and mega-cities within or adjacent to deltas across Asia and Africa. Such migration is driven primarily by economic opportunity, yet environmental change in general, and climate change in particular, are likely to play an increasing direct and indirect role in future migration trends. The policy challenges centre on the role of migration within regional adaptation strategies to climate change; the protection of vulnerable populations; and the future of urban settlements within deltas. This paper reviews current knowledge on migration and adaptation to environmental change to discern specific issues pertinent to delta regions. It develops a new integrated methodology to assess present and future migration in deltas using the Volta delta in Ghana, Mahanadi delta in India and Ganges-Brahmaputra-Meghna delta across India and Bangladesh. The integrated method focuses on: biophysical changes and spatial distribution of vulnerability; demographic changes and migration decision-making using multiple methods and data; macro-economic trends and scenarios in the deltas; and the policies and governance structures that constrain and enable adaptation. The analysis is facilitated by a range of

  10. Delta Plaza kohvik = Delta Plaza cafe

    Index Scriptorium Estoniae

    2010-01-01

    Tallinnas Pärnu mnt 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Tiiu Truusi tähtsamate tööde loetelu. Büroohoone Delta Plaza arhitektid Marika Lõoke ja Jüri Okas (AB J. Okas & M. Lõoke)

  11. delta-vision

    Data.gov (United States)

    California Natural Resource Agency — Delta Vision is intended to identify a strategy for managing the Sacramento-San Joaquin Delta as a sustainable ecosystem that would continue to support environmental...

  12. DELTA project

    International Nuclear Information System (INIS)

    Barbero, Jose A.; Florido, Pablo C.; Mendieta, Horacio; Pasquevich, Daniel M.; Manzano, F.

    1999-01-01

    In this paper we outline a new concept for final treatment of radioactive waste. The process includes the first steps of the reprocessing of burnt fuels up to the final transmutation of the separated long-half-life actinides. (author)

  13. Growth laws for delta crevasses in the Mississippi River Delta: observations and modeling

    Science.gov (United States)

    Yocum, T. A.; Georgiou, I. Y.

    2016-02-01

    River deltas are accumulations of sedimentary deposits delivered by rivers via a network of distributary channels. Worldwide they are threatened by environmental changes, including subsidence, global sea level rise and a suite of other local factors. In the Mississippi River Delta (MRD) these impacts are exemplified, and have led to proposed solutions to build land that include sediment diversions, thereby reinitiating the delta cycle. While economically efficient, there are too few analogs of small deltas aside from laboratory studies, numerical modeling studies, theoretical approaches, and limited field driven observations. Anthropogenic crevasses in the modern delta are large enough to overcome limitations of laboratory deltas, and small enough to allow for "rapid" channel and wetland development, providing an ideal setting to investigate delta development mechanics. Crevasse metrics were obtained using a combination of geospatial tools, extracting key parameters (bifurcation length and width, channel order and depth) that were non-dimensionalized and compared to river-dominated delta networks previously studied. Analysis showed that most crevasses in the MRD appear to obey delta growth laws and delta allometry relationships, suggesting that crevasses do exhibit similar planform metrics to larger Deltas; the distance to mouth bar versus bifurcation order demonstrated to be a very reasonable first order estimate of delta-top footprint. However, some crevasses exhibited different growth metrics. To better understand the hydrodynamic and geomorphic controls governing crevasse evolution in the MRD, we assess delta dynamics via a suite of field observations and numerical modeling in both well-established and newly constructed crevasses. Our analysis suggests that delta development is affected by the relative influence of external (upstream and downstream) and internal controls on the hydrodynamic and sediment transport patterns in these systems.

  14. People of the Delta

    Energy Technology Data Exchange (ETDEWEB)

    Gregoire, L.

    2007-09-15

    The potential impacts of both global warming and the $16 billion Mackenzie pipeline project on communities in the Mackenzie Delta were discussed. A consortium of oil and gas developers is now planning to exploit the natural gas reserves located near the mouth of the Delta, whose largest town is Inuvik. The project is expected to place a significant burden on the resources and infrastructure of the town, which currently has a population of 6000. The community, comprised of a diverse international population and an Inuit majority, is largely in favour of the pipeline project. The Inuvialuit people have invested a significant amount of time to ensure that the project, which was stalled due to land claims in 1977, benefits their communities. Public hearings are now being held to consider the potential environmental and socio-economic impacts of the project. Separate hearings are also being held to consider the project's design. The pipeline project includes 3 natural gas production facilities, a gas-processing facility, a pipeline gathering system, a 480 km natural gas liquids pipeline to the Northwest Territories, and a 1220 km natural gas pipeline to northern Alberta. The pipeline will be buried to minimize environmental impacts. The project is expected to create 8200 jobs at the height of its construction. However, communities located near the site of the natural gas reserves, such as the town of Tuktoyaktuk are now threatened by soil erosion that has been attributed to global warming. 21 figs.

  15. Delta antibody radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Kselikova, M; Urbankova, J

    1985-11-15

    The principle and procedure are described of the radioimmunoassay of delta antibody (delta-Ab) using the ABBOTT ANTI-DELTA kit by Abbott Co. A description is given of the kit, the working procedure and the method of evaluation. The results are reported of the incidence of delta-Ab in sera of patients with viral hepatitis B, in haemophiliacs, carriers of the hepatitis B virus surface antigen (HBsAg) and blood donors. The presence was detected of delta-Ab in one HBsAg carrier. The necessity is emphasized of delta-Ab determinations in the blood of donors in view of the antibody transfer with blood and blood preparations.

  16. Governance of ‘long term delta planning’ in Bangladesh, Vietnam and the Netherlands

    NARCIS (Netherlands)

    Staveren, van M.F.

    2014-01-01

    The Deltas in Times of Climate Change Conference II, taking place in September 2014, Rotterdam, presented a suitable occasion to discuss both delta challenges and interesting approaches to how ‘delta dynamics’ are being dealt with worldwide.1 Delta dynamics include here both environmental (including

  17. Delta hedging strategies comparison

    DEFF Research Database (Denmark)

    De Giovanni, Domenico; Ortobelli, S.; Rachev, S.T.

    2008-01-01

    In this paper we implement dynamic delta hedging strategies based on several option pricing models. We analyze different subordinated option pricing models and we examine delta hedging costs using ex-post daily prices of S&P 500. Furthermore, we compare the performance of each subordinated model...

  18. Connectivity in river deltas

    Science.gov (United States)

    Passalacqua, P.; Hiatt, M. R.; Sendrowski, A.

    2016-12-01

    Deltas host approximately half a billion people and are rich in ecosystem diversity and economic resources. However, human-induced activities and climatic shifts are significantly impacting deltas around the world; anthropogenic disturbance, natural subsidence, and eustatic sea-level rise are major causes of threat to deltas and in many cases have compromised their safety and sustainability, putting at risk the people that live on them. In this presentation, I will introduce a framework called Delta Connectome for studying connectivity in river deltas based on different representations of a delta as a network. Here connectivity indicates both physical connectivity (how different portions of the system interact with each other) as well as conceptual (pathways of process coupling). I will explore several network representations and show how quantifying connectivity can advance our understanding of system functioning and can be used to inform coastal management and restoration. From connectivity considerations, the delta emerges as a leaky network that evolves over time and is characterized by continuous exchanges of fluxes of matter, energy, and information. I will discuss the implications of connectivity on delta functioning, land growth, and potential for nutrient removal.

  19. Growth laws for sub-delta crevasses in the Mississippi River Delta

    Science.gov (United States)

    Yocum, T. A.; Georgiou, I. Y.; Straub, K. M.

    2017-12-01

    River deltas are threatened by environmental change, including subsidence, global sea level rise, reduced sediment inputs and other local factors. In the Mississippi River Delta (MRD) these impacts are exemplified, and have led to proposed solutions to build land that include sediment diversions to reinitiate the delta cycle. Deltas were studied extensively using numerical models, theoretical and conceptual frameworks, empirical scaling relationships, laboratory models and field observations. But predicting the future of deltas relies on field observations where for most deltas data are still lacking. Moreover, empirical and theoretical scaling laws may be influenced by the data used to develop them, while laboratory deltas may be influenced by scaling issues. Anthropogenic crevasses in the MRD are large enough to overcome limitations of laboratory deltas, and small enough to allow for rapid channel and wetland development, providing an ideal setting to investigate delta development mechanics. Here we assessed growth laws of sub-delta crevasses (SDC) in the MRD, in two experimental laboratory deltas (LD - weakly and strongly cohesive) and compared them to river dominated deltas worldwide. Channel and delta geometry metrics for each system were obtained using geospatial tools, bathymetric datasets, sediment size, and hydrodynamic observations. Results show that SDC follow growth laws similar to large river dominated deltas, with the exception of some that exhibit anomalous behavior with respect to the frequency and distance to a bifurcation and the fraction of wetted delta shoreline (allometry metrics). Most SDC exhibit a systematic decrease of non-dimensional channel geometries with increased bifurcation order, indicating that channels are adjusting to decreased flow after bifurcations occur, and exhibit linear trends for land allometry and width-depth ratio, although geometries decrease more rapidly per bifurcation order. Measured distance to bifurcations in SDC

  20. Tidal controls on river delta morphology

    Science.gov (United States)

    Hoitink, A. J. F.; Wang, Z. B.; Vermeulen, B.; Huismans, Y.; Kästner, K.

    2017-09-01

    River delta degradation has been caused by extraction of natural resources, sediment retention by reservoirs, and sea-level rise. Despite global concerns about these issues, human activity in the world’s largest deltas intensifies. Harbour development, construction of flood defences, sand mining and land reclamation emerge as key contemporary factors that exert an impact on delta morphology. Tides interacting with river discharge can play a crucial role in the morphodynamic development of deltas under pressure. Emerging insights into tidal controls on river delta morphology suggest that--despite the active morphodynamics in tidal channels and mouth bar regions--tidal motion acts to stabilize delta morphology at the landscape scale under the condition that sediment import during low flows largely balances sediment export during high flows. Distributary channels subject to tides show lower migration rates and are less easily flooded by the river because of opposing non-linear interactions between river discharge and the tide. These interactions lead to flow changes within channels, and a more uniform distribution of discharge across channels. Sediment depletion and rigorous human interventions in deltas, including storm surge defence works, disrupt the dynamic morphological equilibrium and can lead to erosion and severe scour at the channel bed, even decades after an intervention.

  1. The Niger Delta Crisis

    African Journals Online (AJOL)

    chifaou.amzat

    2013-09-28

    Sep 28, 2013 ... Department of History & International Studies, Delta State University, Abraka,. Nigeria. .... democracy implies popular power. That is ... Okonta (2006:5) draws attention to Anna Zalik's treatise called 'Petro-Vio- lence' and ...

  2. Delta agent (Hepatitis D)

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000216.htm Hepatitis D (Delta agent) To use the sharing features on this page, please enable JavaScript. Hepatitis D is a viral infection caused by the ...

  3. Delta 2.0

    DEFF Research Database (Denmark)

    Skott, Jeppe; Skott, Charlotte Krog; Jess, Kristine

    DELTA 2.0 er en ny og helt opdateret udgave af Delta, der i ti år været brugt i matematiklærernes grund-, efter- og videreuddannelse. DELTA 2.0 er seriens almene fagdidaktik. Der er også fagdidaktiske overvejelser i de øvrige bøger i serien, men de er knyttet til specifikt matematisk indhold. DELTA...... 2.0 behandler mere generelle matematikdidaktiske problemstillinger såsom læringsteoretiske overvejelser i forbindelse med matematik, centrale aspekter af det at undervise i matematik og digitale teknologier som værktøj til at støtte elevers faglige læring af matematik....

  4. Migration in Vulnerable Deltas: A Research Strategy

    Science.gov (United States)

    Hutton, C.; Nicholls, R. J.; Allan, A.

    2015-12-01

    C. Hutton1, & R. J. Nicholls1, , 1 University of Southampton, University Road, Southampton, Hampshire, United Kingdom, SO17 1BJ. cwh@geodata. soton.ac.ukAbstractGlobally, deltas contain 500 million people and with rising sea levels often linked to large number of forced migrants are expected in the coming century. However, migration is already a major process in deltas, such as the growth of major cities such as Dhaka and Kolkata. Climate and environmental change interacts with a range of catchment and delta level drivers, which encompass a nexus of sea-level rise, storms, freshwater and sediment supply from the catchment, land degradation, subsidence, agricultural loss and socio-economic stresses. DECCMA (Deltas, Vulnerability and Climate Change: Migration and Adaptation/CARRIA) is investigating migration in the Ganges-Brahmaputra-Meghna (GBM), Mahanadi and Volta Deltas, including the influence of climate change. The research will explore migration from a range of perspectives including governance and stakeholder analysis, demographic analysis, household surveys of sending and receiving areas, macro-economic analysis, and hazards and hotspot analysis both historically and into the future. Migration under climate change will depend on other adaptation in the deltas and this will be examined. Collectively, integrated analysis will be developed to examine migration, other adaptation and development pathways with a particular focus on the implications for the poorest. This will require the development of input scenarios, including expert-derived exogenous scenarios (e.g., climate change) and endogenous scenarios of the delta developed in a participatory manner. This applied research will facilitate decision support methods for the development of deltas under climate change, with a focus on migration and other adaptation strategies.

  5. Women of Niger Delta

    African Journals Online (AJOL)

    Religion Dept

    The Indispensability of Women in Conflict Resolution in the Niger Delta ... The situation leads to a shift in gender roles with a dramatic increase in the number of women .... organization is to work in partnership with the Nigerian Government and the .... that “women are the impartial arbitrators in family or clan disputes or.

  6. Conservative Delta Hedging

    Science.gov (United States)

    1997-09-01

    an exact method for converting such intervals into arbitrage based prices of financial derivatives or industrial or contractual options. We call this...procedure conservative delta hedging . As existing procedures are of an ad hoc nature, the proposed approach will permit an institution’s man agement a greater oversight of its exposure to risk.

  7. Hepatitis delta genotypes in chronic delta infection in the northeast of Spain (Catalonia).

    Science.gov (United States)

    Cotrina, M; Buti, M; Jardi, R; Quer, J; Rodriguez, F; Pascual, C; Esteban, R; Guardia, J

    1998-06-01

    Based on genetic analysis of variants obtained around the world, three genotypes of the hepatitis delta virus have been defined. Hepatitis delta virus variants have been associated with different disease patterns and geographic distributions. To determine the prevalence of hepatitis delta virus genotypes in the northeast of Spain (Catalonia) and the correlation with transmission routes and clinical disease, we studied the nucleotide divergence of the consensus sequence of HDV RNA obtained from 33 patients with chronic delta hepatitis (24 were intravenous drug users and nine had no risk factors), and four patients with acute self-limited delta infection. Serum HDV RNA was amplified by the polymerase chain reaction technique and a fragment of 350 nucleotides (nt 910 to 1259) was directly sequenced. Genetic analysis of the nucleotide consensus sequence obtained showed a high degree of conservation among sequences (93% of mean). Comparison of these sequences with those derived from different geographic areas and pertaining to genotypes I, II and III, showed a mean sequence identity of 92% with genotype I, 73% with genotype II and 61% with genotype III. At the amino acid level (aa 115 to 214), the mean identity was 87% with genotype I, 63% with genotype II and 56% with genotype III. Conserved regions included the RNA editing domain, the carboxyl terminal 19 amino acids of the hepatitis delta antigen and the polyadenylation signal of the viral mRNA. Hepatitis delta virus isolates in the northeast of Spain are exclusively genotype I, independently of the transmission route and the type of infection. No hepatitis delta virus subgenotypes were found, suggesting that the origin of hepatitis delta virus infection in our geographical area is homogeneous.

  8. Mystery of the delta(980)

    International Nuclear Information System (INIS)

    Cahn, R.N.; Landshoff, P.V.

    1986-01-01

    The apparent conflict between the dominance of the decay delta->etaπ in D->deltaπ and its absence in iota->deltaπ is analyzed. Explicit models are presented in which the nearby Kanti K threshold plays an important role in resolving the conflict. (orig.)

  9. Upper-division student difficulties with the Dirac delta function

    Directory of Open Access Journals (Sweden)

    Bethany R. Wilcox

    2015-03-01

    Full Text Available The Dirac delta function is a standard mathematical tool that appears repeatedly in the undergraduate physics curriculum in multiple topical areas including electrostatics, and quantum mechanics. While Dirac delta functions are often introduced in order to simplify a problem mathematically, students still struggle to manipulate and interpret them. To characterize student difficulties with the delta function at the upper-division level, we examined students’ responses to traditional exam questions and a standardized conceptual assessment, and conducted think-aloud interviews. Our analysis was guided by an analytical framework that focuses on how students activate, construct, execute, and reflect on the Dirac delta function in the context of problem solving in physics. Here, we focus on student difficulties using the delta function to express charge distributions in the context of junior-level electrostatics. Common challenges included invoking the delta function spontaneously, translating a description of a charge distribution into a mathematical expression using delta functions, integrating 3D or non-Cartesian delta function expressions, and recognizing that the delta function can have units. We also briefly discuss implications of these difficulties for instruction.

  10. Upper-Division Student Difficulties with the Dirac Delta Function

    Science.gov (United States)

    Wilcox, Bethany R.; Pollock, Steven J.

    2015-01-01

    The Dirac delta function is a standard mathematical tool that appears repeatedly in the undergraduate physics curriculum in multiple topical areas including electrostatics, and quantum mechanics. While Dirac delta functions are often introduced in order to simplify a problem mathematically, students still struggle to manipulate and interpret them.…

  11. Open source integrated modeling environment Delta Shell

    Science.gov (United States)

    Donchyts, G.; Baart, F.; Jagers, B.; van Putten, H.

    2012-04-01

    In the last decade, integrated modelling has become a very popular topic in environmental modelling since it helps solving problems, which is difficult to model using a single model. However, managing complexity of integrated models and minimizing time required for their setup remains a challenging task. The integrated modelling environment Delta Shell simplifies this task. The software components of Delta Shell are easy to reuse separately from each other as well as a part of integrated environment that can run in a command-line or a graphical user interface mode. The most components of the Delta Shell are developed using C# programming language and include libraries used to define, save and visualize various scientific data structures as well as coupled model configurations. Here we present two examples showing how Delta Shell simplifies process of setting up integrated models from the end user and developer perspectives. The first example shows coupling of a rainfall-runoff, a river flow and a run-time control models. The second example shows how coastal morphological database integrates with the coastal morphological model (XBeach) and a custom nourishment designer. Delta Shell is also available as open-source software released under LGPL license and accessible via http://oss.deltares.nl.

  12. Climate change and the Delta

    Science.gov (United States)

    Dettinger, Michael; Anderson, Jamie; Anderson, Michael L.; Brown, Larry R.; Cayan, Daniel; Maurer, Edwin P.

    2016-01-01

    Anthropogenic climate change amounts to a rapidly approaching, “new” stressor in the Sacramento–San Joaquin Delta system. In response to California’s extreme natural hydroclimatic variability, complex water-management systems have been developed, even as the Delta’s natural ecosystems have been largely devastated. Climate change is projected to challenge these management and ecological systems in different ways that are characterized by different levels of uncertainty. For example, there is high certainty that climate will warm by about 2°C more (than late-20th-century averages) by mid-century and about 4°C by end of century, if greenhouse-gas emissions continue their current rates of acceleration. Future precipitation changes are much less certain, with as many climate models projecting wetter conditions as drier. However, the same projections agree that precipitation will be more intense when storms do arrive, even as more dry days will separate storms. Warmer temperatures will likely enhance evaporative demands and raise water temperatures. Consequently, climate change is projected to yield both more extreme flood risks and greater drought risks. Sea level rise (SLR) during the 20th century was about 22cm, and is projected to increase by at least 3-fold this century. SLR together with land subsidence threatens the Delta with greater vulnerabilities to inundation and salinity intrusion. Effects on the Delta ecosystem that are traceable to warming include SLR, reduced snowpack, earlier snowmelt and larger storm-driven streamflows, warmer and longer summers, warmer summer water temperatures, and water-quality changes. These changes and their uncertainties will challenge the operations of water projects and uses throughout the Delta’s watershed and delivery areas. Although the effects of climate change on Delta ecosystems may be profound, the end results are difficult to predict, except that native species will fare worse than invaders. Successful

  13. Sediment and Vegetation Controls on Delta Channel Networks

    Science.gov (United States)

    Lauzon, R.; Murray, A. B.; Piliouras, A.; Kim, W.

    2016-12-01

    Numerous factors control the patterns of distributary channels formed on a delta, including water and sediment discharge, grain size, sea level rise rates, and vegetation type. In turn, these channel networks influence the shape and evolution of a delta, including what types of plant and animal life - such as humans - it can support. Previous fluvial modeling and flume experiments, outside of the delta context, have addressed how interactions between sediment and vegetation, through their influence on lateral transport of sediment, determine what type of channel networks develops. Similar interactions likely also shape delta flow patterns. Vegetation introduces cohesion, tending to reduce channel migration rates and strengthen existing channel banks, reinforcing existing channels and resulting in localized, relatively stable flow patterns. On the other hand, sediment transport processes can result in lateral migration and frequent switching of active channels, resulting in flow resembling that of a braided stream. While previous studies of deltas have indirectly explored the effects of vegetation through the introduction of cohesive sediment, we directly incorporate key effects of vegetation on flow and sediment transport into the delta-building model DeltaRCM to explore how these effects influence delta channel network formation. Model development is informed by laboratory flume experiments at UT Austin. Here we present initial results of experiments exploring the effects of sea level rise rate, sediment grain size, vegetation type, and vegetation growth rate on delta channel network morphology. These results support the hypothesis that the ability for lateral transport of sediment to occur plays a key role in determining the evolution of delta channel networks and delta morphology.

  14. Applications of Dirac's Delta Function in Statistics

    Science.gov (United States)

    Khuri, Andre

    2004-01-01

    The Dirac delta function has been used successfully in mathematical physics for many years. The purpose of this article is to bring attention to several useful applications of this function in mathematical statistics. Some of these applications include a unified representation of the distribution of a function (or functions) of one or several…

  15. Losing ground in mega-deltas: basin-scale response to existential threats to the Mekong Delta

    Science.gov (United States)

    Arias, M. E.; Kondolf, G. M.; Schmitt, R. J. P.; Carling, P. A.; Darby, S. E.; Bizzi, S.; Castelletti, A.; Cochrane, T. A.; Gibson, S.; Kummu, M.; Oeurng, C.; Rubin, Z.; Wild, T. B.

    2017-12-01

    The Mekong Delta is, in terms of the number of livelihoods it supports, its economic importance, and in its vulnerability to climate change and sinking lands, one of the world's critically threatened mega-deltas. Livelihoods depend on the mere existence of the delta, but also on ecosystem services provided by the delta's drainage basin spanning 795,000 km2 in six abutting countries. These ecosystem services include delivery of sand required to build delta land in the face of rising sea-levels and sediment bound nutrients, provision of spawning habitat for fish that are ultimately harvested in the delta, and hydrologic regulation driving the delta's unique flood-pulse regime. However, while the delta is mainly located in Vietnam, the basin of the Mekong River is shared among China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. In the context of the region's dynamic growth, individual countries are pushing their own development agendas, which include extensive dam building, in-channel sand mining, construction of dykes and canals, and groundwater pumping, all of which contribute to subsidence and erosion of the Delta. Our synthesis of recent research indicates that most of the Mekong's delta land will likely fall below sea-level by 2100 as result of these drivers, exacerbating the impacts of global climatic changes. In this context, local infrastructural projects and changes in land- and water-management may temporarily mitigate some negative effects, but do not address the existential threat to the delta as a whole. To prevent, or at least substantially postpone, the drowning of the Mekong Delta requires identification of the key drivers and immediate concerted management actions on the basin-scale to change the trajectory of subsidence and sediment deficit. A specific challenge is to find the institutional arrangements in this transnational context that could support the needed management changes and equitably distribute costs and impacts. The Mekong Delta is

  16. The evolution of a subaqueous delta in the Anthropocene: A stratigraphic investigation of the Brazos River delta, TX USA

    Science.gov (United States)

    Carlin, Joseph A.; Dellapenna, Timothy M.

    2015-12-01

    Globally, deltas are increasingly threatened by anthropogenic activities. As a result, deltas now evolve through the combined effects of natural and human-induced processes occurring throughout the fluvial-deltaic system. The Brazos River delta, located along the Texas coast in the northwestern Gulf of Mexico, and its watershed have been impacted by direct and indirect human activities since the late 19th century. This provides an opportunity to investigate how such alterations have shaped the evolution of a delta in the Anthropocene, a time when humans are drivers of geological change. Historic alteration to the delta and watershed include extensive agricultural activity, jetty construction at the mouth in the late 1890s, mouth diversion ~10 km to the southwest in 1929, and reservoir construction throughout the early and mid 20th Century. Three subaerial deltaic geometries provided the framework to connect subaerial deltaic responses, to the anthropogenic alterations, to the resulting stratigraphic characteristics observed in the subaqueous delta. This study utilized high-resolution geophysical data (swath bathymetry, side scan sonar, CHIRP subbottom profiling) on the subaqueous delta to investigate the subaqueous delta stratigraphy and infer the processes that shaped the deltaic record over time. The results showed distinct areas across the subaqueous delta that were dominated by erosion and deposition. Erosional areas corresponded to earlier growth phase depocenters being exposed at the surface, while the depositional areas corresponded to areas with the most recent growth phase depocenter overlying the earlier depocenters. These results highlight that the subaqueous depocenter has migrated westward over time, consistent with the observed changes to the subaerial delta. Additionally, the data showed that evidence for these past growth phases and depocenters may be preserved within the subaqueous delta, even after subaerial portions of the delta returned to pre

  17. Thermostatted delta f

    International Nuclear Information System (INIS)

    Krommes, J.A.

    2000-01-01

    The delta f simulation method is revisited. Statistical coarse-graining is used to rigorously derive the equation for the fluctuation delta f in the particle distribution. It is argued that completely collisionless simulation is incompatible with the achievement of true statistically steady states with nonzero turbulent fluxes because the variance of the particle weights w grows with time. To ensure such steady states, it is shown that for dynamically collisionless situations a generalized thermostat or W-stat may be used in lieu of a full collision operator to absorb the flow of entropy to unresolved fine scales in velocity space. The simplest W-stat can be implemented as a self-consistently determined, time-dependent damping applied to w. A precise kinematic analogy to thermostatted nonequilibrium molecular dynamics (NEMD) is pointed out, and the justification of W-stats for simulations of turbulence is discussed. An extrapolation procedure is proposed such that the long-time, steady-state, collisionless flux can be deduced from several short W-statted runs with large effective collisionality, and a numerical demonstration is given

  18. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    NARCIS (Netherlands)

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR

    1999-01-01

    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia

  19. Peat compaction in deltas : implications for Holocene delta evolution

    NARCIS (Netherlands)

    van Asselen, S.

    2010-01-01

    Many deltas contain substantial amounts of peat, which is the most compressible soil type. Therefore, peat compaction potentially leads to high amounts of subsidence in deltas. The main objective of this research was to quantify subsidence due to peat compaction in Holocene fluvial-deltaic settings

  20. Challenges, Approaches and Experiences from Asian Deltas and the Rhine-Meuse Delta : Regional Training Workshop on Delta Planning and Management

    NARCIS (Netherlands)

    Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

    2013-01-01

    River delta's, like the Mekong Delta (Vietnam), Ganges-Brahmaputra Delta (Bangladesh), Ayeyarwady Delta (Myanmar), Nile (Egypt) and Ciliwung Delta (Indonesia) are developing rapidly and are characterised by large-scale urbanisation and industrialization processes. They are facing serious planning

  1. Mida pakub Delta? / Teele Kurm

    Index Scriptorium Estoniae

    Kurm, Teele

    2011-01-01

    Politsei- ja Piirivalveamet võtab kasutusele ühise Siseministeeriumi infotehnoloogia- ja arenduskeskuse ning Webmedia AS koostööna loodud dokumendihaldussüsteemi Delta. Kust sai Delta oma nime? Projekti "Dokumendihaldussüsteemi juurutamine Siseministeeriumi haldusalas" eesmärgid

  2. Delta isobars in neutron stars

    Directory of Open Access Journals (Sweden)

    Pagliara Giuseppe

    2015-01-01

    Full Text Available The appearance of delta isobars in beta-stable matter is regulated by the behavior of the symmetry energy at densities larger than saturation density. We show that by taking into account recent constraints on the density derivative of the symmetry energy and the theoretical and experimental results on the excitations of delta isobars in nuclei, delta isobars are necessary ingredients for the equations of state used for studying neutron stars. We analyze the effect of the appearance of deltas on the structure of neutron stars: as in the case of hyperons, matter containing delta is too soft for allowing the existence of 2M⊙ neutron stars. Quark stars on the other hand, could reach very massive configurations and they could form from a process of conversion of hadronic stars in which an initial seed of strangeness appears through hyperons.

  3. Perspectives on bay-delta science and policy

    Science.gov (United States)

    Healey, Michael; Dettinger, Michael; Norgaard, Richard

    2016-01-01

    The State of Bay–Delta Science 2008 highlighted seven emerging perspectives on science and management of the Delta. These perspectives had important effects on policy and legislation concerning management of the Delta ecosystem and water exports. From the collection of papers that make up the State of Bay–Delta Science 2016, we derive another seven perspectives that augment those published in 2008. The new perspectives address nutrient and contaminant concentrations in Delta waters, the failure of the Delta food web to support native species, the role of multiple stressors in driving species toward extinction, and the emerging importance of extreme events in driving change in the ecosystem and the water supply. The scientific advances that underpin these new perspectives were made possible by new measurement and analytic tools. We briefly discuss some of these, including miniaturized acoustic fish tags, sensors for monitoring of water quality, analytic techniques for disaggregating complex contaminant mixtures, remote sensing to assess levee vulnerability, and multidimensional hydrodynamic modeling. Despite these new tools and scientific insights, species conservation objectives for the Delta are not being met. We believe that this lack of progress stems in part from the fact that science and policy do not incorporate sufficiently long-term perspectives. Looking forward half a century was central to the Delta Visioning process, but science and policy have not embraced this conceptual breadth. We are also concerned that protection and enhancement of the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place, as required by the Delta Reform Act, has received no critical study and analysis. Adopting wider and longer science and policy perspectives immediately encourages recognition of the need for evaluation, analysis, and public discourse on novel conservation approaches. These longer and wider perspectives

  4. DELTA 3D PRINTER

    Directory of Open Access Journals (Sweden)

    ȘOVĂILĂ Florin

    2016-07-01

    Full Text Available 3D printing is a very used process in industry, the generic name being “rapid prototyping”. The essential advantage of a 3D printer is that it allows the designers to produce a prototype in a very short time, which is tested and quickly remodeled, considerably reducing the required time to get from the prototype phase to the final product. At the same time, through this technique we can achieve components with very precise forms, complex pieces that, through classical methods, could have been accomplished only in a large amount of time. In this paper, there are presented the stages of a 3D model execution, also the physical achievement after of a Delta 3D printer after the model.

  5. The sensitivity of the ESA DELTA model

    Science.gov (United States)

    Martin, C.; Walker, R.; Klinkrad, H.

    Long-term debris environment models play a vital role in furthering our understanding of the future debris environment, and in aiding the determination of a strategy to preserve the Earth orbital environment for future use. By their very nature these models have to make certain assumptions to enable informative future projections to be made. Examples of these assumptions include the projection of future traffic, including launch and explosion rates, and the methodology used to simulate break-up events. To ensure a sound basis for future projections, and consequently for assessing the effectiveness of various mitigation measures, it is essential that the sensitivity of these models to variations in key assumptions is examined. The DELTA (Debris Environment Long Term Analysis) model, developed by QinetiQ for the European Space Agency, allows the future projection of the debris environment throughout Earth orbit. Extensive analyses with this model have been performed under the auspices of the ESA Space Debris Mitigation Handbook and following the recent upgrade of the model to DELTA 3.0. This paper draws on these analyses to present the sensitivity of the DELTA model to changes in key model parameters and assumptions. Specifically the paper will address the variation in future traffic rates, including the deployment of satellite constellations, and the variation in the break-up model and criteria used to simulate future explosion and collision events.

  6. Fast delta Hadamard transform

    International Nuclear Information System (INIS)

    Fenimore, E.E.; Weston, G.S.

    1981-01-01

    In many fields (e.g., spectroscopy, imaging spectroscopy, photoacoustic imaging, coded aperture imaging) binary bit patterns known as m sequences are used to encode (by multiplexing) a series of measurements in order to obtain a larger throughput. The observed measurements must be decoded to obtain the desired spectrum (or image in the case of coded aperture imaging). Decoding in the past has used a technique called the fast Hadamard transform (FHT) whose chief advantage is that it can reduce the computational effort from N 2 multiplies of N log 2 N additions or subtractions. However, the FHT has the disadvantage that it does not readily allow one to sample more finely than the number of bits used in the m sequence. This can limit the obtainable resolution and cause confusion near the sample boundaries (phasing errors). Both 1-D and 2-D methods (called fast delta Hadamard transforms, FDHT) have been developed which overcome both of the above limitations. Applications of the FDHT are discussed in the context of Hadamard spectroscopy and coded aperture imaging with uniformly redundant arrays. Special emphasis has been placed on how the FDHT can unite techniques used by both of these fields into the same mathematical basis

  7. How Rapid Change Affects Deltas in the Arctic Region

    Science.gov (United States)

    Overeem, I.; Bendixen, M.

    2017-12-01

    Deltas form where the river drains into the ocean. Consequently, delta depositional processes are impacted by either changes in the respective river drainage basin or by changes in the regional marine environment. In a warming Arctic region rapid change has occurred over the last few decades in both the terrestrial domain as well as in the marine domain. Important terrestrial controls include 1) change in permafrost possibly destabilizing river banks, 2) strong seasonality of river discharge due to a short melting season, 3) high sediment supply if basins are extensively glaciated, 4) lake outbursts and ice jams favoring river flooding. Whereas in the Arctic marine domain sea ice loss promotes wave and storm surge impact, and increased longshore transport. We here ask which of these factors dominate any morphological change in Arctic deltas. First, we analyze hydrological data to assess change in Arctic-wide river discharge characteristics and timing, and sea ice concentration data to map changes in sea ice regime. Based on this observational analysis we set up a number of scenarios of change. We then model hypothetical small-scale delta formation considering change in these primary controls by setting up a numerical delta model, and combining it dynamically with a permafrost model. We find that for typical Greenlandic deltas changes in river forcing due to ice sheet melt dominate the morphological change, which is corroborated by mapping of delta progradation from aerial photos and satellite imagery. Whereas in other areas, along the North Slope and the Canadian Arctic small deltas are more stable or experienced retreat. Our preliminary coupled model allows us to further disentangle the impact of major forcing factors on delta evolution in high-latitude systems.

  8. Hot deformation behavior of delta-processed superalloy 718

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y., E-mail: wangyanhit@yahoo.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); School of Aeronautics and Astronautics, Central South University, Changsha 410083 (China); Shao, W.Z.; Zhen, L.; Zhang, B.Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-03-25

    Research highlights: {yields} The peak stress for hot deformation can be described by the Z parameter. {yields} The grain size of DRX was inversely proportional to the Z parameter. {yields} The dissolution of {delta} phases was greatly accelerated under hot deformation. {yields}The {delta} phase stimulated nucleation can serve as the main DRX mechanism. - Abstract: Flow stress behavior and microstructures during hot compression of delta-processed superalloy 718 at temperatures from 950 to 1100 deg. C with strain rates of 10{sup -3} to 1 s{sup -1} were investigated by optical microscopy (OM), electron backscatter diffraction (EBSD) technique and transmission electron microscopy (TEM). The relationship between the peak stress and the deformation conditions can be expressed by a hyperbolic-sine type equation. The activation energy for the delta-processed superalloy 718 is determined to be 467 kJ/mol. The change of the dominant deformation mechanisms leads to the decrease of stress exponent and the increase of activation energy with increasing temperature. The dynamically recrystallized grain size is inversely proportional to the Zener-Hollomon (Z) parameter. It is found that the dissolution rate of {delta} phases under hot deformation conditions is much faster than that under static conditions. Dislocation, vacancy and curvature play important roles in the dissolution of {delta} phases. The main nucleation mechanisms of dynamic recrystallization (DRX) for the delta-processed superalloy 718 include the bulging of original grain boundaries and the {delta} phase stimulated DRX nucleation, which is closely related to the dissolution behavior of {delta} phases under certain deformation conditions.

  9. Energy deposition by delta rays

    International Nuclear Information System (INIS)

    Weigand, F.C.; Braby, L.A.

    1983-01-01

    Monte Carlo calculations for proton tracks were extended to projectile with more complex electronic structures which add additional delta ray production processes. An experimental apparatus was used to detect gas gain and resolution for H 2+ and 3 He ++

  10. Niger Delta Development Commission and Sustainable ...

    African Journals Online (AJOL)

    Niger Delta Development Commission and Sustainable Development of Niger Delta Region of Nigeria: The Case of Rivers State. Goddey Wilson. Abstract. The study is on Niger Delta Development Commission and sustainable development of Niger Delta region of Nigeria, the case of Rivers State. The main objective of the ...

  11. Population dynamics, delta vulnerability and environmental change: comparison of the Mekong, Ganges–Brahmaputra and Amazon delta regions

    OpenAIRE

    Szabo, S.; Brondizio, E.; Renaud, F.G.; Hetrick, S.; Nicholls, R.; Matthews, Z.; Tessler, Z; Tejedor, A; Sebesvari, Z; Foufoula-Georgiou, E; da Costa, S; Dearing, J.A.

    2016-01-01

    Tropical delta regions are at risk of multiple threats including relative sea level rise and human alterations, making them more and more vulnerable to extreme floods, storms, surges, salinity intrusion, and other hazards which could also increase in magnitude and frequency with a changing climate. Given the environmental vulnerability of tropical deltas, understanding the interlinkages between population dynamics and environmental change in these regions is crucial for ensuring efficient pol...

  12. Understanding delta-sigma data converters

    CERN Document Server

    Pavan, Shanti; Temes, Gabor C

    2017-01-01

    This new edition introduces novel analysis and design techniques for delta-sigma (ΔΣ) converters in physical and conceptual terms, and includes new chapters that explore developments in the field over the last decade. This book explains the principles and operation of delta-sigma analog-to-digital converters (ADCs) in physical and conceptual terms in accordance with the most recent developments in the field. The interest of ΔΣ converter designers has shifted significantly over the past decade, due to many new applications for data converters at the far ends of the frequency spectrum. Continuous-time delta-sigma A/D converters with GHz clocks, of both lowpass and bandpass types, are required for wireless applications. At the other extreme, multiplexed ADCs with very narrow (sometimes 10 Hz wide) signal bandwidths, but very high accuracy are needed in the interfaces of biomedical and environmental sensors. To reflect the changing eeds of designers, the second edition includes significant new material on bo...

  13. Changes in the areal extents of the Athabasca River, Birch River, and Cree Creek Deltas, 1950-2014, Peace-Athabasca Delta, Canada

    Science.gov (United States)

    Timoney, Kevin; Lee, Peter

    2016-04-01

    Deltas form where riverborne sediment accumulates at the interface of river mouths and their receiving water bodies. Their areal extent is determined by the net effect of processes that increase their extent, such as sediment accumulation, and processes that decrease their extent, such as erosion and subsidence. Through sequential mapping and construction of river discharge and sediment histories, this study examined changes in the subaerial extents of the Cree Creek and Athabasca River Deltas (both on the Athabasca River system) and the Birch River Delta in northern Canada over the period 1950-2014. The purpose of the study was to determine how, when, and why the deltas changed in areal extent. Temporal growth patterns were similar across the Athabasca and Birch River systems indicative of a climatic signal. Little or no areal growth occurred from 1950 to 1968; moderate growth occurred between 1968 and the early to mid-1980s; and rapid growth occurred between 1992 and 2012. Factors that affected delta progradation included dredging, sediment supply, isostatic drowning, delta front bathymetry, sediment capture efficiency, and storms. In relation to sediment delivered, areal growth rates were lowest in the Athabasca Delta, intermediate in the Birch Delta, and highest in the Cree Creek Delta. Annual sediment delivery is increasing in the Cree Creek Delta; there were no significant trends in annual sediment delivery in the Birch and Athabasca Deltas. There was a lag of up to several years between sediment delivery events and progradation. Periods of delta progradation were associated with low water levels of the receiving basins. Predicted climate-change driven declines in river discharge and lake levels may accelerate delta progradation in the region. In the changing ecosystems of northeastern Alberta, inadequate monitoring of vegetation, landforms, and sediment regimes hampers the elucidation of the nature, rate, and causality of ecosystem changes.

  14. Effect of environmental change on the morphology of tidally influenced deltas over multi-decadal timescale

    Science.gov (United States)

    Angamuthu, Balaji; Darby, Stephen; Nicholls, Robert

    2017-04-01

    results to the contemporary GBM delta implies that cross-dams and polders have been a key control on the morphodynamic evolution of the GBM delta over the last 60 years. However, with increased fluvial water discharge and rates of RSLR likely under greenhouse gas (GHG) -driven warming, the continuing use of sediment starved polders will only increase the vulnerability of poldered areas from regular flooding, and eventually may lead to catastrophic, permanent, inundation of the land. Hence, the future trend of morphological evolution of the GBM delta depends on local human intervention, including measures to raise the elevation of the land to cope with the continuing trend of RSLR and varying fluvial discharges. The model findings provide a basis to establish guidelines for planned future management interventions to prevent the delta from destruction.

  15. $\\delta$-Expansion at Finite Temperature

    OpenAIRE

    Ramos, Rudnei O.

    1996-01-01

    We apply the $\\delta$-expansion perturbation scheme to the $\\lambda \\phi^{4}$ self-interacting scalar field theory in 3+1 D at finite temperature. In the $\\delta$-expansion the interaction term is written as $\\lambda (\\phi^{2})^{ 1 + \\delta}$ and $\\delta$ is considered as the perturbation parameter. We compute within this perturbative approach the renormalized mass at finite temperature at a finite order in $\\delta$. The results are compared with the usual loop-expansion at finite temperature.

  16. Anaerobic Transformation of Furfural by Methanococcus deltae (Delta)LH

    Science.gov (United States)

    Belay, N.; Boopathy, R.; Voskuilen, G.

    1997-01-01

    Methanococcus deltae (Delta)LH was grown on H(inf2)-CO(inf2) in the presence of various concentrations of furfural. Furfural at higher concentrations, namely, 20 and 25 mM, inhibited growth of this organism. At concentration of 5 and 10 mM, no inhibition of growth was observed. The other methanogens in this study were not inhibited by 10 mM furfural. Among the methanogens tested, M. deltae was capable of transforming furfural, whereas Methanobacterium thermoautotrophicum Marburg, Methanosarcina barkeri 227, Methanococcus thermolithotrophicus, and Methanobrevibacter ruminantium lacked this capability. One hundred percent removal of furfural was observed within 48 h of incubation in M. deltae cultures. The end product observed during furfural metabolism was furfuryl alcohol. An almost stoichiometric amount of furfuryl alcohol was produced by M. deltae. This transformation is likely to be of value in the detoxification of furfural and in its ultimate conversion to methane and CO(inf2) by anaerobic digestion. PMID:16535618

  17. Delta Morphodynamics Matters! Ecosystem Services, Poverty and Morphodynamic Change in the Ganges-Brahmaputra Mega-Delta

    Science.gov (United States)

    Nicholls, R. J.; Adger, N.; Allan, A.; Darby, S. E.; Hutton, C.; Matthews, Z.; Rahman, M.; Whitehead, P. G.; Wolf, J.

    2013-12-01

    The world's deltas are probably the most vulnerable type of coastal environment, and they face multiple stresses in the coming decades. These stresses include, amongst others, local drivers due to land subsidence, population growth and urbanisation within the deltas, regional drivers due to changes in catchment management (e.g. upstream land use and dam construction), as well as global climate change impacts such as sea-level rise. At the same time, the ecosystem services of river deltas support high population densities, with around 14% of the global population inhabiting deltas. A large proportion of these people experience extremes of poverty and they are therefore severely exposed to vulnerability from environmental and ecological stress and degradation. In areas close to or below the poverty boundary, both subsistence and cash elements of the economy tend to rely disproportionately heavily on ecosystem services which underpin livelihoods. Therefore, to sustainably manage delta environments they must be viewed as complex social-environmental systems where change is only partially driven by physical drivers such as sea level rise and climate change, and human-induced development activities are also critical. Here we outline a new conceptual framework for the development of methods to understand and characterise the key drivers of change in ecosystem services that affect the environment and economic status of populous deltas, focusing specifically on the Ganges-Brahmaputra-Meghna (GBM) mega-delta. The GBM delta is characterised by densely populated coastal lowlands with significant poverty, with livelihoods supported to a large extent by natural ecosystems such as the Sunderbahns (the largest mangrove forest in the world). However, the GBM delta is under severe development pressure due to many growing cities. At present the importance of ecosystems services to poverty and livelihoods is poorly understood. This is due to due to the complexity of interactions

  18. Casscf/ci Calculations for First Row Transition Metal Hydrides - the TIH(4-PHI), VH(5-DELTA), CRH(6-SIGMA-PLUS), MNH(7-SIGMA-PLUS), FEH(4,6-DELTA) and NIH(2-DELTA) States

    Science.gov (United States)

    Walch, S. P.; Bauschlicher, C. W., Jr.

    1983-04-01

    Calculations are performed for the predicted ground states of TiH(4-phi), VH(5-delta), CrH(6-sigma-plus), MnH(7-sigma-plus), Fett(4,6-delta) and NiH(2-delta). For FeH both the 6-delta and 4-delta states are studied, since both are likely candidates for the ground state. The ground state symmetries are predicted based on a combination of atomic coupling arguments and coupling of 4s(2)3d(n) and 4s(1)3d(n+1) terms in the molecular system. Electron correlation is included by a CASSCF/CI (SD) treatment. The CASSCF includes near-degeneracy effects, while correlation of the 3d electrons in included at the CI level.

  19. Four new Delta Scuti stars

    Science.gov (United States)

    Schutt, R. L.

    1991-01-01

    Four new Delta Scuti stars are reported. Power, modified into amplitude, spectra, and light curves are used to determine periodicities. A complete frequency analysis is not performed due to the lack of a sufficient time base in the data. These new variables help verify the many predictions that Delta Scuti stars probably exist in prolific numbers as small amplitude variables. Two of these stars, HR 4344 and HD 107513, are possibly Am stars. If so, they are among the minority of variable stars which are also Am stars.

  20. Hydrological and Climatic Significance of Martian Deltas

    Science.gov (United States)

    Di Achille, G.; Vaz, D. A.

    2017-10-01

    We a) review the geomorphology, sedimentology, and mineralogy of the martian deltas record and b) present the results of a quantitative study of the hydrology and sedimentology of martian deltas using modified version of terrestrial model Sedflux.

  1. Adaptive delta management : Roots and branches

    NARCIS (Netherlands)

    Timmermans, J.S.; Haasnoot, M.; Hermans, L.M.; Kwakkel, J.H.; Rutten, M.M.; Thissen, W.A.H.

    2015-01-01

    Deltas are generally recognized as vulnerable to climate change and therefore a salient topic in adaptation science. Deltas are also highly dynamic systems viewed from physical (erosion, sedimentation, subsidence), social (demographic), economic (trade), infrastructures (transport, energy,

  2. Adaptive Delta Management : Roots and Branches

    NARCIS (Netherlands)

    Timmermans, Jos; Haasnoot, Marjolijn; Hermans, Leon; Kwakkel, Jan H.; Rutten, Maarten; Thissen, Wil A.H.; Mynett, Arthur

    2015-01-01

    Deltas are generally recognized as vulnerable to climate change and therefore a salient topic in adaptation science. Deltas are also highly dynamic systems viewed from physical (erosion, sedimentation, subsidence), social (demographic), economic (trade), infrastructures (transport, energy,

  3. Delta Vegetation and Land Use [ds292

    Data.gov (United States)

    California Natural Resource Agency — Vegetation and land use are mapped for the approximately 725,000 acres constituting the Legal Delta portion of the Sacramento and San Joaquin River Delta area....

  4. Delta Scuti variables. Lecture 6

    International Nuclear Information System (INIS)

    Cox, A.N.

    1983-01-01

    The class of variables near or on the upper main sequence, the delta Scuti variables, are not only the usual ones about the masses, radii, and luminosities, but also the age, rotation, element diffusion to change the surface layer composition, the occurance of convection and the presence of radial and nonradial pulsation modes

  5. about the Dirac Delta Function(?)

    Indian Academy of Sciences (India)

    V Balakrishnan is in the. Department of ... and sweet as befits this impatient age. It said (in its en- ... to get down to real work by shutting down the system and reverting to ... the Dirac delta function" - but do note the all-important question mark in ...

  6. Perspectives on Bay–Delta Science and Policy

    Directory of Open Access Journals (Sweden)

    Michael Healey

    2016-12-01

    Full Text Available doi: https://doi.org/10.15447/sfews.2016v14iss4art6The State of Bay–Delta Science 2008 highlighted seven emerging perspectives on science and management of the Delta. These perspectives had important effects on policy and legislation concerning management of the Delta ecosystem and water exports. From the collection of papers that make up the State of Bay–Delta Science 2016, we derive another seven perspectives that augment those published in 2008. The new perspectives address nutrient and contaminant concentrations in Delta waters, the failure of the Delta food web to support native species, the role of multiple stressors in driving species toward extinction, and the emerging importance of extreme events in driving change in the ecosystem and the water supply. The scientific advances that underpin these new perspectives were made possible by new measurement and analytic tools. We briefly discuss some of these, including miniaturized acoustic fish tags, sensors for monitoring of water quality, analytic techniques for disaggregating complex contaminant mixtures, remote sensing to assess levee vulnerability, and multidimensional hydrodynamic modeling. Despite these new tools and scientific insights, species conservation objectives for the Delta are not being met. We believe that this lack of progress stems in part from the fact that science and policy do not incorporate sufficiently long-term perspectives. Looking forward half a century was central to the Delta Visioning process, but science and policy have not embraced this conceptual breadth. We are also concerned that protection and enhancement of the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place, as required by the Delta Reform Act, has received no critical study and analysis. Adopting wider and longer science and policy perspectives immediately encourages recognition of the need for evaluation, analysis, and public discourse on

  7. Heavy baryon chiral perturbation theory and the spin 3/2 delta resonances

    Energy Technology Data Exchange (ETDEWEB)

    Kambor, J.

    1996-12-31

    Heavy baryon chiral perturbation theory is briefly reviewed, paying particular attention to the role of the spin 3/2 delta resonances. The concept of resonance saturation for the baryonic sector is critically discussed. Starting from a relativistic formulation of the pion-nucleon-delta system, the heavy baryon chiral Lagrangian including spin 3/2 resonances is constructed by means of a 1/m-expansion. The effective theory obtained admits a systematic expansion in terms of soft momenta, the pion mass M{sub {pi}} and the delta-nucleon mass difference {Delta}. (author). 22 refs.

  8. Variation in leaf water delta D and delta 18O values during the evapotranspiration process

    International Nuclear Information System (INIS)

    Leopoldo, P.R.; Foloni, L.L.

    1984-01-01

    A theoretical model was developed to evaluate leaf water delta D and delta 18 O variation in relation to: leaf temperature, relative humidity converted to leaf temperature and delta D and delta 18 O values of atmospheric water vapour and soil water. (M.A.C.) [pt

  9. An analytical framework for strategic delta planning

    NARCIS (Netherlands)

    Seijger, C.; Douven, W.; Halsema, van G.; Hermans, L.; Evers, J.; Phi, H.L.; Khan, M.F.; Brunner, J.; Pols, L.; Ligtvoet, W.; Koole, S.; Slager, K.; Vermoolen, M.S.; Hasan, S.; Thi Minh Hoang, Vo

    2017-01-01

    Sectoral planning on water, agriculture and urban development has not been able to prevent increased flood risks and environmental degradation in many deltas. Governments conceive strategic delta planning as a promising planning approach and develop strategic delta plans. Such plans are linked to

  10. Delta Semantics Defined By Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kyng, Morten; Madsen, Ole Lehrmann

    and the possibility of using predicates to specify state changes. In this paper a formal semantics for Delta is defined and analysed using Petri nets. Petri nets was chosen because the ideas behind Petri nets and Delta concide on several points. A number of proposals for changes in Delta, which resulted from...

  11. Doomed to drown? Sediment dynamics in the human-controlled floodplains of the active Bengal Delta

    Directory of Open Access Journals (Sweden)

    Kimberly G. Rogers

    2017-11-01

    Full Text Available The Ganges-Brahmaputra-Meghna (Bengal Delta in Bangladesh has been described as a delta in peril of catastrophic coastal flooding because sediment deposition on delta plain surfaces is insufficient to offset rates of subsidence and sea level rise. Widespread armoring of the delta by coastal embankments meant to protect crops from flooding has limited natural floodplain deposition, and in the tidally dominated delta, dikes lead to rapid compaction and lowered land surface levels. This renders the deltaic floodplains susceptible to flooding by sea level rise and storm surges capable of breaching poorly maintained embankments. However, natural physical processes are spatially variable across the delta front and therefore the impact of dikes on sediment dispersal and morphology should reflect these variations. We present the first ever reported sedimentation rates from the densely populated and human-controlled floodplains of the central lower Bengal Delta. We combine direct sedimentation measurements and short-lived radionuclides to show that transport processes and lateral sedimentation are highly variable across the delta. Overall aggradation rates average 2.3 ± 9 cm y–1, which is more than double the estimated average rate of local sea level rise; 83% of sampled sites contained sediment tagged with detectable 7 Be, indicating flood-pulse sourced sediments are widely delivered to the delta plain, including embanked areas. A numerical model is then used to demonstrate lateral accretion patterns arising from 50 years of sedimentation delivered through smaller order channels. Dominant modes of transport are reflected in the sediment routing and aggradation across the lower delta plain, though embankments are major controls on sediment dynamics throughout the delta. This challenges the assumption that the Bengal Delta is doomed to drown; rather it signifies that effective preparation for climate change requires consideration of how infrastructure

  12. Construction and maintenance of the Ganges-Brahmaputra-Meghna delta: linking process, morphology, and stratigraphy.

    Science.gov (United States)

    Wilson, Carol A; Goodbred, Steven L

    2015-01-01

    We present a review of the processes, morphology, and stratigraphy of the Ganges-Brahmaputra-Meghna delta (GBMD), including insights gained from detailed elevation data. The review shows that the GBMD is best characterized as a composite system, with different regions having morphologic and stratigraphic attributes of an upland fluvial fan delta; a lowland, backwater-reach delta; a downdrift tidal delta plain; and an offshore subaqueous-delta clinoform. These distinct areas of upland and lowland fluvial reaches and tidal dominance vary in time and space, and we distinguish late-Holocene phases of delta construction, maintenance, and decline similar to delta-lobe cycling in other systems. The overall stability of the GBMD landform, relative to many deltas, reflects the efficient, widespread dispersal of sediment by the large monsoon discharge and high-energy tides that affect this region. However, we do identify portions of the delta that are in decline and losing elevation relative to sea level owing to insufficient sediment delivery. These areas, some of which are well inland of the coast, represent those most at risk to the continued effect of sea-level rise.

  13. The case for selection at CCR5-Delta32.

    Directory of Open Access Journals (Sweden)

    2005-11-01

    Full Text Available The C-C chemokine receptor 5, 32 base-pair deletion (CCR5-Delta32 allele confers strong resistance to infection by the AIDS virus HIV. Previous studies have suggested that CCR5-Delta32 arose within the past 1,000 y and rose to its present high frequency (5%-14% in Europe as a result of strong positive selection, perhaps by such selective agents as the bubonic plague or smallpox during the Middle Ages. This hypothesis was based on several lines of evidence, including the absence of the allele outside of Europe and long-range linkage disequilibrium at the locus. We reevaluated this evidence with the benefit of much denser genetic maps and extensive control data. We find that the pattern of genetic variation at CCR5-Delta32 does not stand out as exceptional relative to other loci across the genome. Moreover using newer genetic maps, we estimated that the CCR5-Delta32 allele is likely to have arisen more than 5,000 y ago. While such results can not rule out the possibility that some selection may have occurred at C-C chemokine receptor 5 (CCR5, they imply that the pattern of genetic variation seen atCCR5-Delta32 is consistent with neutral evolution. More broadly, the results have general implications for the design of future studies to detect the signs of positive selection in the human genome.

  14. The case for selection at CCR5-Delta32.

    Directory of Open Access Journals (Sweden)

    Pardis C Sabeti

    2005-11-01

    Full Text Available The C-C chemokine receptor 5, 32 base-pair deletion (CCR5-Delta32 allele confers strong resistance to infection by the AIDS virus HIV. Previous studies have suggested that CCR5-Delta32 arose within the past 1,000 y and rose to its present high frequency (5%-14% in Europe as a result of strong positive selection, perhaps by such selective agents as the bubonic plague or smallpox during the Middle Ages. This hypothesis was based on several lines of evidence, including the absence of the allele outside of Europe and long-range linkage disequilibrium at the locus. We reevaluated this evidence with the benefit of much denser genetic maps and extensive control data. We find that the pattern of genetic variation at CCR5-Delta32 does not stand out as exceptional relative to other loci across the genome. Moreover using newer genetic maps, we estimated that the CCR5-Delta32 allele is likely to have arisen more than 5,000 y ago. While such results can not rule out the possibility that some selection may have occurred at C-C chemokine receptor 5 (CCR5, they imply that the pattern of genetic variation seen at CCR5-Delta32 is consistent with neutral evolution. More broadly, the results have general implications for the design of future studies to detect the signs of positive selection in the human genome.

  15. Astrometric Observation of Delta Cepheus

    Science.gov (United States)

    Warren, Naomi; Wilson, Betsie; Estrada, Chris; Crisafi, Kim; King, Jackie; Jones, Stephany; Salam, Akash; Warren, Glenn; Collins, S. Jananne; Genet, Russell

    2012-04-01

    Members of a Cuesta College astronomy research seminar used a manually-controlled 10-inch Newtonian Reflector telescope to determine the separation and position angle of the binary star Delta Cepheus. It was observed on the night of Saturday, October 29, 2011, at Star Hill in Santa Margarita, California. Their values of 40.2 arc seconds and 192.4 degrees were similar to those reported in the WDS (1910).

  16. Effects of external influences in subsonic delta wing vortices

    Science.gov (United States)

    Washburn, Anthony E.

    1992-01-01

    An experimental investigation was conducted to examine inconsistencies in reported studies for the vortical flow over highly-swept delta wings. A 76-deg swept delta wing was tested in three facilities with open and closed test sections and different model-support systems. The results obtained include surface oil-flow patterns, off-body laser-light-sheet flow visualization, and aerodynamic load measurements. Parameters such as the wall boundaries and model-support systems can drastically alter the loads. The effect of a high level of free-stream turbulence on the delta-wing flowfield was also examined and found to be significant. The increase in free-stream turbulence caused boundary-layer transition, unsteadiness in the vortex core positions, and altered the loads and moments.

  17. Deformation characteristics of {delta} phase in the delta-processed Inconel 718 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.Y., E-mail: haiyanzhang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Zhang, S.H., E-mail: shzhang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Cheng, M. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Li, Z.X. [Beijing Institute of Aeronautica1 Materials, Beijing 100095 (China)

    2010-01-15

    The hot working characteristics of {delta} phase in the delta-processed Inconel 718 alloy during isothermal compression deformation at temperature of 950 deg. C and strain rate of 0.005 s{sup -1}, were studied by using optical microscope, scanning electron microscope and quantitative X-ray diffraction technique. The results showed that the dissolution of plate-like {delta} phase and the precipitation of spherical {delta} phase particles coexisted during the deformation, and the content of {delta} phase decreased from 7.05 wt.% to 5.14 wt.%. As a result of deformation breakage and dissolution breakage, the plate-like {delta} phase was spheroidized and transferred to spherical {delta} phase particles. In the center with largest strain, the plate-like {delta} phase disappeared and spherical {delta} phase appeared in the interior of grains and grain boundaries.

  18. Stable isotope deltas: Tiny, yet robust signatures in nature

    Science.gov (United States)

    Brand, Willi A.; Coplen, Tyler B.

    2012-01-01

    Although most of them are relatively small, stable isotope deltas of naturally occurring substances are robust and enable workers in anthropology, atmospheric sciences, biology, chemistry, environmental sciences, food and drug authentication, forensic science, geochemistry, geology, oceanography, and paleoclimatology to study a variety of topics. Two fundamental processes explain the stable isotope deltas measured in most terrestrial systems: isotopic fractionation and isotope mixing. Isotopic fractionation is the result of equilibrium or kinetic physicochemical processes that fractionate isotopes because of small differences in physical or chemical properties of molecular species having different isotopes. It is shown that the mixing of radioactive and stable isotope end members can be modelled to provide information on many natural processes, including 14C abundances in the modern atmosphere and the stable hydrogen and oxygen isotopic compositions of the oceans during glacial and interglacial times. The calculation of mixing fractions using isotope balance equations with isotope deltas can be substantially in error when substances with high concentrations of heavy isotopes (e.g. 13C, 2H, and 18O ) are mixed. In such cases, calculations using mole fractions are preferred as they produce accurate mixing fractions. Isotope deltas are dimensionless quantities. In the International System of Units (SI), these quantities have the unit 1 and the usual list of prefixes is not applicable. To overcome traditional limitations with expressing orders of magnitude differences in isotope deltas, we propose the term urey (symbol Ur), after Harold C. Urey, for the unit 1. In such a manner, an isotope delta value expressed traditionally as−25 per mil can be written as−25 mUr (or−2.5 cUr or−0.25 dUr; the use of any SI prefix is possible). Likewise, very small isotopic differences often expressed in per meg ‘units’ are easily included (e.g. either+0.015 ‰ or+15 per meg

  19. Tides Stabilize Deltas until Humans Interfere

    Science.gov (United States)

    Hoitink, T.; Zheng Bing, W.; Vermeulen, B.; Huismans, Y.; Kastner, K.

    2017-12-01

    Despite global concerns about river delta degradation caused by extraction of natural resources, sediment retention by reservoirs and sea-level rise, human activity in the world's largest deltas intensifies. In this review, we argue that tides tend to stabilize deltas until humans interfere. Under natural circumstances, delta channels subject to tides are more stable than their fluvial-dominated counterparts. The oscillatory tidal flow counteracts the processes responsible for bank erosion, which explains why unprotected tidal channels migrate only slowly. Peak river discharges attenuate the tides, which creates storage space to accommodate the extra river discharge during extreme events and as a consequence, reduce flood risk. With stronger tides, the river discharge is being distributed more evenly over the various branches in a delta, preventing silting up of smaller channels. Human interference in deltas is massive. Storm surge barriers are constructed, new land is being reclaimed and large-scale sand excavation takes place, to collect building material. Evidence from deltas around the globe shows that in human-controlled deltas the tidal motion often plays a destabilizing role. In channels of the Rhine-Meuse Delta, some 100 scour holes are identified, which relates to the altered tidal motion after completion of a storm surge barrier. Sand mining has led to widespread river bank failures in the tidally-influenced Mekong Delta. The catastrophic flood event in the Gauges-Brahmaputra Delta by Cyclone Aila, which caused the inundation of an embanked polder area for over two years, was preceded by river bank erosion at the mouths of formal tidal channels that were blocked by the embankment. Efforts to predict the developments of degrading deltas are few. Existing delta models are capable of reproducing expanding deltas, which is essentially a matter of simulating the transport of sediment from source in a catchment to the sink in a delta. Processes of soil

  20. 75 FR 56094 - Delta-Mendota Canal Intertie Project

    Science.gov (United States)

    2010-09-15

    ... Project AGENCY: Western Area Power Administration, DOE. ACTION: Notice of Record of Decision and... maintain a new 69-kilovolt (kV) transmission line and fiber optic cable for delivery of project use power...) Delta-Mendota Canal (DMC)/California Aqueduct Intertie (Intertie) project. The Intertie, including the...

  1. Dynamic Balancing of Clavel’s Delta Robot

    NARCIS (Netherlands)

    van der Wijk, V.; Herder, Justus Laurens; Kecskemethy, Andres; Müller, Andreas

    2009-01-01

    The Delta robot has shown to be a useful device in many applications. Due to large accelerations however, vibrations can decrease the accuracy and performance considerably. Instead of common techniques to reduce vibrations such as damping or including waiting times in the motion cycle, this article

  2. Watershed-Scale Modeling of Land-Use and Altered Environment Impacts on Aquatic Weed Growth in the Delta

    Science.gov (United States)

    Bubenheim, David; Potter, Christopher; Zhang, Minghua

    2016-01-01

    The California Sacramento-San Joaquin River Delta is the hub for California's water supply, conveying water from Northern to Southern California agriculture and communities while supporting important ecosystem services, agriculture, and communities in the Delta. Changes in climate, long-term drought, and water quality have all been suspected as playing role in the dramatic expansion of invasive aquatic plants and their impact on ecosystems of the San Francisco Bay / California Delta complex. NASA Ames Research Center, USDA-Agricultural Research Service, the State of California, UC Davis, and local governments have partnered under a USDA sponsored project (DRAAWP) to develop science-based, adaptive-management strategies for invasive aquatic plants in Sacramento-San Joaquin Delta. Critical to developing management strategies is to understand how the Delta is affected by both the magnitude of fluctuations in land-use and climate / drought induced altered environments and how the plants respond to these altered environments. We utilize the Soil Water Assessment Tool (SWAT), a watershed-scale model developed to quantify the impact of land management practices in large and complex watersheds on water quality, as the backbone for a customized Delta model - Delta-SWAT. The model uses land-use, soils, elevation, and hydrologic routing to characterize pesticide and nutrient transport from the Sacramento and San Joaquin rivers watersheds and loading into the Delta. Land-use within the Delta, as well as water extraction to supply those functions, and the resulting return of water to Delta waterways are included in Delta-SWAT. Hydrologic transport within the Delta has required significant attention to address the lack of elevation driven transport processes. Delta-SWAT water quality trend estimates are compared with water quality monitoring conducted throughout the Delta. Aquatic plant response to water quality and other environmental factors is carried out using a customized

  3. Future Deltas Utrecht University research focus area: towards sustainable management of sinking deltas

    Science.gov (United States)

    Stouthamer, E.; van Asselen, S.

    2015-11-01

    Deltas are increasingly under pressure from human impact and climate change. To deal with these pressures that threat future delta functioning, we need to understand interactions between physical, biological, chemical and social processes in deltas. This requires an integrated approach, in which knowledge on natural system functioning is combined with knowledge on spatial planning, land and water governance and legislative frameworks. In the research focus area Future Deltas of Utrecht University an interdisciplinary team from different research groups therefore works together. This allows developing integrated sustainable and resilient delta management strategies, which is urgently needed to prevent loss of vital delta services.

  4. COMMD1 regulates the delta epithelial sodium channel ({delta}ENaC) through trafficking and ubiquitination

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Tina; Ke, Ying; Ly, Kevin [Department of Physiology, University of Otago, P.O. Box 913, Dunedin 9054 (New Zealand); McDonald, Fiona J., E-mail: fiona.mcdonald@otago.ac.nz [Department of Physiology, University of Otago, P.O. Box 913, Dunedin 9054 (New Zealand)

    2011-08-05

    Highlights: {yields} The COMM domain of COMMD1 mediates binding to {delta}ENaC. {yields} COMMD1 reduces the cell surface population of {delta}ENaC. {yields} COMMD1 increases the population of {delta}ENaC-ubiquitin. {yields} Both endogenous and transfected {delta}ENaC localize with COMMD1 and transferrin suggesting they are located in early/recycling endosomes. -- Abstract: The delta subunit of the epithelial sodium channel ({delta}ENaC) is a member of the ENaC/degenerin family of ion channels. {delta}ENaC is distinct from the related {alpha}-, {beta}- and {gamma}ENaC subunits, known for their role in sodium homeostasis and blood pressure control, as {delta}ENaC is expressed in brain neurons and activated by external protons. COMMD1 (copper metabolism Murr1 domain 1) was previously found to associate with and downregulate {delta}ENaC activity. Here, we show that COMMD1 interacts with {delta}ENaC through its COMM domain. Co-expression of {delta}ENaC with COMMD1 significantly reduced {delta}ENaC surface expression, and led to an increase in {delta}ENaC ubiquitination. Immunocytochemical and confocal microscopy studies show that COMMD1 promoted localization of {delta}ENaC to the early/recycling endosomal pool where the two proteins were localized together. These results suggest that COMMD1 downregulates {delta}ENaC activity by reducing {delta}ENaC surface expression through promoting internalization of surface {delta}ENaC to an intracellular recycling pool, possibly via enhanced ubiquitination.

  5. Nigeria. Petroleum, pollution and poverty in the Niger Delta

    International Nuclear Information System (INIS)

    2009-06-01

    The oil industry has operated in the Niger Delta in Nigeria for more than half a century - bringing almost no benefit to the people living there. Instead, widespread and unchecked human rights violations have pushed many people deeper into poverty and deprivation, fuelled conflict and led to a pervasive sense of powerlessness and frustration. This multidimensional crisis is driven by many factors - abuses committed by the security forces and militant groups, extensive pollution of land and water, corruption, serious corporate bad practice and government neglect. Nigeria: Petroleum, pollution and poverty in the Niger Delta focuses on one dimension of the crisis: the impact of pollution and environmental damage caused by the oil industry on the human rights of those living in the Niger Delta. Many people in the oil-producing areas of the delta rely on fisheries, subsistence agriculture and associated processing industries for their livelihood. Decades of pollution and environmental damage have resulted in violations of the right to an adequate standard of living - including food and water - violations of the right to gain a living through work, and violations of the right to health. The report examines who is responsible for this situation in a context where multinational oil companies have been operating for decades. It highlights how companies take advantage of the weak regulatory systems that characterize many poor countries, and how the poorest people are often the most vulnerable to exploitation. The people of the Niger Delta have seen their human rights undermined by oil companies that their government can not - or will not - hold to account. They have been systematically denied access to information about how oil exploration and production will affect them, and are repeatedly denied access to justice. The Niger Delta provides a stark case study of the lack of accountability of a government to the people, and of multinational companies' almost total lack of

  6. The Niger Delta Amnesty Program

    Directory of Open Access Journals (Sweden)

    Benjamin A. Okonofua

    2016-06-01

    Full Text Available The armed conflict between militias and government forces in Nigeria’s Niger Delta region has spanned for more than two decades, defying all solutions. A disarmament, demobilization, and reintegration (DDR program was established in August 2015 in effort to end the violence and has remained in place. It is a radically different approach from past approaches that displayed zero tolerance to all political challenges to oil production or the allocation of oil profits. The approach appeared to be immediately successful in that it forced a ceasefire, engaged militants in planned programs to rehabilitate and reintegrate them into civilian society, and opened up the oil wells (many of which had been shut due to the crisis with the effect of increasing government revenue, which depends 85% on oil exports. Yet, few studies have attempted to understand the dynamics within the country that are responsible for the design and implementation of this broad policy shift or to understand whether and how the current initiative is able to end the conflict and institute peace beyond the short term. This study, therefore, is important because it provides a critical perspective that anticipates and explains emerging issues with the Niger Delta Amnesty Program, which have implications for DDR adaptation and implementation all over the world. Ultimately, the research demonstrates how the DDR program both transforms the Niger Delta conflict and becomes embroiled in intense contestations not only about the mechanism for transforming the targeted population but also whether and how the program incorporates women who are being deprioritized by the program.

  7. Penelope Delta, recently discovered writer

    OpenAIRE

    MALAPANI A.

    2015-01-01

    The aim of this article is to present a Greek writer, Penelope Delta. This writer has recently come up in the field of the studies of the Greek literature and, although thereare neither many translations of her works in foreign languages nor many theses or dissertations, she was chosen for the great interest for her works. Her books have been read by many generations, so she is considered a classical writer of Modern Greek Literature. The way she uses the Greek language, the unique characters...

  8. From Natural to Design River Deltas

    Science.gov (United States)

    Giosan, Liviu

    2016-04-01

    Productive and biologically diverse, deltaic lowlands attracted humans since prehistory and may have spurred the emergence of the first urban civilizations. Deltas continued to be an important nexus for economic development across the world and are currently home for over half a billion people. But recently, under the double whammy of sea level rise and inland sediment capture behind dams, they have become the most threatened coastal landscape. Here I will address several deceptively simple questions to sketch some unexpected answers using example deltas from across the world from the Arctic to the Tropics, from the Danube to the Indus, Mississippi to Godavari and Krishna, Mackenzie to Yukon. What is a river delta? What is natural and what is not in a river delta? Are the geological and human histories of a delta important for its current management? Is maintaining a delta the same to building a new one? Can we design better deltas than Nature? These answers help us see clearly that survival of deltas in the next century depends on human intervention and is neither assured nor simple to address or universally applicable. Empirical observations on the hydrology, geology, biology and biochemistry of deltas are significantly lagging behind modeling capabilities endangering the applicability of numerical-based reconstruction solutions and need to be ramped up significantly and rapidly across the world.

  9. El plan del delta - Holanda

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1963-09-01

    Full Text Available Holland is very poor in land resources. Hence its development has been directed towards intensive industrialization and maximum agricultural exploitation. The western part of the country is below sea level and is occupied by 65 percent of the population. Originally the coast consisted of a number of islands, estuaries and slight elevations. Man has transformed this coastline, first making a number of artificial lakes, or polders, and then converting these into fertile districts. These projects protect the soil by means of dykes, which require careful conservation, but even so violent floods are not infrequent. One of the difficult problems involved in this vast enterprise is the complex system of water supply, lines of communication and flow of the rivers into the sea along the estuary zone. This zone is on the south west, and to protect it a National Commission has been set up. After careful study, it was decided that the best defense against the violence of the sea would consist in closing off the inroads of the sea into the continental coastline. The set of hydraulic projects which constitutes this plan for the improvement of the sea defences will take 25 years to fulfil. The general project is highly ambitious and includes both maritime, road and structural works, in which there is a variety of stonework constructions. This paper describes, in brief outline, the main contents of the 11 headings into which the general construction project has been subdivided. In addition, this is supplemented with information on the projects which are already initiated and on the constructional procedure that is being adopted. Of these latter projects, the Nabla bridge is of particular interest. It is situated on the delta. It is made in prestressed concrete, and consists of 17 spans, of 60 length each. This enormous structure, in addition to its great length, and supporting a 22.8 ms wide roadway, is subjected to the tremendous forces 11» of the sea on one

  10. Carbon storage in the Mississippi River delta enhanced by environmental engineering

    Science.gov (United States)

    Shields, Michael R.; Bianchi, Thomas S.; Mohrig, David; Hutchings, Jack A.; Kenney, William F.; Kolker, Alexander S.; Curtis, Jason H.

    2017-11-01

    River deltas have contributed to atmospheric carbon regulation throughout Earth history, but functioning in the modern era has been impaired by reduced sediment loads, altered hydrologic regimes, increased global sea-level rise and accelerated subsidence. Delta restoration involves environmental engineering via river diversions, which utilize self-organizing processes to create prograding deltas. Here we analyse sediment cores from Wax Lake delta, a product of environmental engineering, to quantify the burial of organic carbon. We find that, despite relatively low concentrations of organic carbon measured in the cores (about 0.4%), the accumulation of about 3 T m-2 of sediment over the approximate 60 years of delta building resulted in the burial of a significant amount of organic carbon (16 kg m-2). This equates to an apparent organic carbon accumulation rate of 250 +/- 23 g m-2 yr-1, which implicitly includes losses by carbon emissions and erosion. Our estimated accumulation rate for Wax Lake delta is substantially greater than previous estimates based on the top metre of delta sediments and comparable to those of coastal mangrove and marsh habitats. The sedimentation of carbon at the Wax Lake delta demonstrates the capacity of engineered river diversions to enhance both coastal accretion and carbon burial.

  11. $\\delta N$ formalism from superpotential and holography

    CERN Document Server

    Garriga, Jaume; Vernizzi, Filippo

    2016-02-16

    We consider the superpotential formalism to describe the evolution of scalar fields during inflation, generalizing it to include the case with non-canonical kinetic terms. We provide a characterization of the attractor behaviour of the background evolution in terms of first and second slow-roll parameters (which need not be small). We find that the superpotential is useful in justifying the separate universe approximation from the gradient expansion, and also in computing the spectra of primordial perturbations around attractor solutions in the $\\delta N$ formalism. As an application, we consider a class of models where the background trajectories for the inflaton fields are derived from a product separable superpotential. In the perspective of the holographic inflation scenario, such models are dual to a deformed CFT boundary theory, with $D$ mutually uncorrelated deformation operators. We compute the bulk power spectra of primordial adiabatic and entropy cosmological perturbations, and show that the results...

  12. An analytical framework for strategic delta planning : negotiating consent for long-term sustainable delta development

    NARCIS (Netherlands)

    Seijger, C.; Douven, W; Hermans, L.M.; Evers, J.; Phi, H. L.; Brunner, J.; Pols, L.; Ligtvoet, W.; Koole, S.; Slager, K.; Vermoolen, M.S.; Hasan, S.; Hoang, V. T M; van Halsema, G

    2016-01-01

    Sectoral planning on water, agriculture and urban development has not been able to prevent increased flood risks and environmental degradation in many deltas. Governments conceive strategic delta planning as a promising planning approach and develop strategic delta plans. Such plans are linked to

  13. Protoneutron star formation with delta-resonance matter and trapped neutrinos

    International Nuclear Information System (INIS)

    Oliveira, Jose Carlos Teixeira de; Souza, Ana Graice de; Duarte, Sergio Barbosa; Rodrigues, Hilario

    2009-01-01

    Full text: We discuss the proto-neutron star structure including delta-matter in its composition, and comparing the result with the same mass post-cooling compact object formed. The maximum mass values and corresponding configurations to pre and post-cooling situation are calculated and discussed face to variations in the coupling constants of delta-resonance with the mesons sigma, omega and rho in the context of the Relativistic Mean Field Theory (RMFT). The complete spin-1/2 sector is included solved consistently with the presence of the 3/2-spin delta-resonance quartet. (author)

  14. Identification of anthropogenic and natural inputs of sulfate and chloride into the karstic ground water of Guiyang, SW China: combined delta37Cl and delta34S approach.

    Science.gov (United States)

    Liu, Cong-Qiang; Lang, Yun-Chao; Satake, Hiroshi; Wu, Jiahong; Li, Si-Liang

    2008-08-01

    Because of active exchange between surface and groundwater of a karstic hydrological system, the groundwater of Guiyang, the capital city of Guizhou Province, southwest China, has been seriously polluted by anthropogenic inputs of NO3-, SO4(2-), Cl-, and Na+. In this work, delta37Cl of chloride and delta34S variations of sulfate in the karstic surface/groundwater system were studied, with a main focus to identify contaminant sources, including their origins. The surface, ground, rain, and sewage water studied showed variable delta37Cl and delta34S values, in the range of -4.1 to +2.0 per thousand, and -20.4 to +20.9 per thousand for delta37Cl and delta34S (SO4(2-)), respectively. The rainwater samples yielded the lowest delta37Cl values among those observed to date for aerosols and rainwater. Chloride in the Guiyang area rain waters emanated from anthropogenic sources rather than being of marine origin, probably derived from HCl (g) emitted by coal combustion. By plotting 1/SO4(2-) vs delta34S and 1/Cl- vs delta37Cl, respectively, we were able to identify some clusters of data, which were assigned as atmospheric deposition (acid rain component), discharge from municipal sewage, paleo-brine components in clastic sedimentary rocks, dissolution of gypsum mainly in dolomite, oxidation of sulfide minerals in coal-containing clastic rocks, and possibly degradation of chlorine-containing organic matter. We conclude that human activities give a significant input of sulfate and chloride ions, as well as other contaminants, into the studied groundwater system through enhanced atmospheric deposition and municipal sewage, and that multiple isotopic tracers constitute a powerful tool to ascertain geochemical characteristics and origin of complex contaminants in groundwater.

  15. Entropy and optimality in river deltas

    Science.gov (United States)

    Tejedor, Alejandro; Longjas, Anthony; Edmonds, Douglas A.; Zaliapin, Ilya; Georgiou, Tryphon T.; Rinaldo, Andrea; Foufoula-Georgiou, Efi

    2017-10-01

    The form and function of river deltas is intricately linked to the evolving structure of their channel networks, which controls how effectively deltas are nourished with sediments and nutrients. Understanding the coevolution of deltaic channels and their flux organization is crucial for guiding maintenance strategies of these highly stressed systems from a range of anthropogenic activities. To date, however, a unified theory explaining how deltas self-organize to distribute water and sediment up to the shoreline remains elusive. Here, we provide evidence for an optimality principle underlying the self-organized partition of fluxes in delta channel networks. By introducing a suitable nonlocal entropy rate (nER) and by analyzing field and simulated deltas, we suggest that delta networks achieve configurations that maximize the diversity of water and sediment flux delivery to the shoreline. We thus suggest that prograding deltas attain dynamically accessible optima of flux distributions on their channel network topologies, thus effectively decoupling evolutionary time scales of geomorphology and hydrology. When interpreted in terms of delta resilience, high nER configurations reflect an increased ability to withstand perturbations. However, the distributive mechanism responsible for both diversifying flux delivery to the shoreline and dampening possible perturbations might lead to catastrophic events when those perturbations exceed certain intensity thresholds.

  16. A Modal Logic for Abstract Delta Modeling

    NARCIS (Netherlands)

    F.S. de Boer (Frank); M. Helvensteijn (Michiel); J. Winter (Joost)

    2012-01-01

    htmlabstractAbstract Delta Modeling is a technique for implementing (software) product lines. Deltas are put in a partial order which restricts their application and are then sequentially applied to a core product in order to form specific products in the product line. In this paper we explore the

  17. Tidal controls on river delta morphology

    NARCIS (Netherlands)

    Hoitink, A.J.F.; Wang, Z.B.; Vermeulen, B.; Huismans, Y.; Kästner, K.

    2017-01-01

    River delta degradation has been caused by extraction of natural resources, sediment retention by reservoirs, and sea-level rise. Despite global concerns about these issues, human activity in the world's largest deltas intensifies. Harbour development, construction of flood defences, sand mining and

  18. Tidal controls on river delta morphology

    NARCIS (Netherlands)

    Hoitink, A.J.F.; Wang, Zhengbing; Vermeulen, B.; Huismans, Y; Kästner, K

    River delta degradation has been caused by extraction of natural resources, sediment retention by reservoirs, and sea-level rise. Despite global concerns about these issues, human activity in the world’s largest deltas intensifies. Harbour development, construction of flood defences, sand mining and

  19. Floating City IJmeer : Accelerator for Delta Technology

    NARCIS (Netherlands)

    De Graaf, R.; Fremouw, M.; Van Bueren, B.; Czapiewska, K.; Kuijper, M.

    2006-01-01

    Climate change, sea level rise, population growth and ongoing urbanization result in higher vulnerability of the Rhine delta because it will result in increased flooding frequency, increasing investments and increased use of water, energy and other resources. The Rhine Delta also faces strong

  20. Childhood nutrition in the Mississippi Delta: challenges and opportunities.

    Science.gov (United States)

    Gray, Virginia B; Byrd, Sylvia H; Fountain, Brent J; Rader, Nicole E; Frugé, Andrew D

    2016-12-01

    Childhood obesity in the USA has more than tripled in the last three decades, and the prevalence is higher in the Mississippi Delta. Insight into the social, cultural and environmental factors that influence inequity can inform efforts to mediate health disparities. Focus groups (n = 12) among parents/guardians of elementary school children (n = 44) and teachers (n = 59) in the Mississippi Delta were used to investigate barriers and facilitators of healthy eating. Transcriptions were analyzed for themes. A strong preference for junk food among children and the pervasiveness of junk foods in schools and communities were cited as barriers to healthy eating. Potential facilitators of healthy eating included desire to avoid chronic disease, effort to limit junk food consumption and school support. Despite support for efforts to improve nutrition in the Delta, participants voiced a sense of inevitability related to children's consumption of unhealthy foods. This study suggests that parents and teachers express concern related to eating habits of children, yet they experience barriers to healthy eating which contribute to a sense of disempowerment. Improving health in the Mississippi Delta requires comprehensive strategies that offer its citizens a sense of agency. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Modern sedimentation and morphology of the subaqueous Mekong Delta, Southern Vietnam

    Science.gov (United States)

    Unverricht, Daniel; Szczuciński, Witold; Stattegger, Karl; Jagodziński, Robert; Le, Xuan Thuyen; Kwong, Laval Liong Wee

    2013-11-01

    The Mekong River Delta is among the Asian mega-deltas and is influenced by various factors including tides (meso-tidal system), waves, coastal currents, monsoon-driven river discharge and human impact (agriculture, fishing, sand dredging, tourism). The present study aims to document the seafloor relief, sediment distribution and sediment accumulation rates to interpret modern sediment transport directions and main sedimentation processes in the subaqueous Mekong Delta. The major results of this investigation include the detection of two delta fronts 200 km apart, one at the mouth of the Bassac River (the biggest branch of the Mekong Delta) and the other around Cape Ca Mau (most south-western end of the Mekong Delta). Additionally, a large channel system runs in the subaqueous delta platform parallel to the shore and between the two fronts. The sediment accumulation rates vary greatly according to the location in the subaqueous delta and have reached up to 10 cm/yr for the last century. A cluster analysis of surface sediment samples revealed two different sediment types within the delta including a well-sorted sandy sediment and a poorly sorted, silty sediment. In addition, a third end member with medium to coarse sand characterised the distant parts of the delta at the transition to the open shelf. The increase of organic matter and carbonate content to the bottom set area and other sedimentary features such as shell fragments, foraminiferas and concretions of palaeo-soils that do not occur in delta sediments, supported grain size-based classification. Beginning in front of the Bassac River mouth, sedimentary pattern indicates clockwise sediment transport alongshore in the western direction to a broad topset area and the delta front around Cape Ca Mau. Our results clearly show the large lateral variability of the subaqueous Mekong Delta that is further complicated by strong monsoon-driven seasonality. River, tidal and wave forcing vary at local and seasonal scales

  2. The geographic spread of the CCR5 Delta32 HIV-resistance allele.

    Directory of Open Access Journals (Sweden)

    John Novembre

    2005-11-01

    Full Text Available The Delta32 mutation at the CCR5 locus is a well-studied example of natural selection acting in humans. The mutation is found principally in Europe and western Asia, with higher frequencies generally in the north. Homozygous carriers of the Delta32 mutation are resistant to HIV-1 infection because the mutation prevents functional expression of the CCR5 chemokine receptor normally used by HIV-1 to enter CD4+ T cells. HIV has emerged only recently, but population genetic data strongly suggest Delta32 has been under intense selection for much of its evolutionary history. To understand how selection and dispersal have interacted during the history of the Delta32 allele, we implemented a spatially explicit model of the spread of Delta32. The model includes the effects of sampling, which we show can give rise to local peaks in observed allele frequencies. In addition, we show that with modest gradients in selection intensity, the origin of the Delta32 allele may be relatively far from the current areas of highest allele frequency. The geographic distribution of the Delta32 allele is consistent with previous reports of a strong selective advantage (>10% for Delta32 carriers and of dispersal over relatively long distances (>100 km/generation. When selection is assumed to be uniform across Europe and western Asia, we find support for a northern European origin and long-range dispersal consistent with the Viking-mediated dispersal of Delta32 proposed by G. Lucotte and G. Mercier. However, when we allow for gradients in selection intensity, we estimate the origin to be outside of northern Europe and selection intensities to be strongest in the northwest. Our results describe the evolutionary history of the Delta32 allele and establish a general methodology for studying the geographic distribution of selected alleles.

  3. Losing ground - scenarios of land loss as consequence of shifting sediment budgets in the Mekong Delta

    Science.gov (United States)

    Schmitt, R. J. P.; Rubin, Z.; Kondolf, G. M.

    2017-10-01

    With changing climate and rising seas, proliferation of hydroelectric dams, instream sand mining, dyking of floodplains, accelerated subsidence from groundwater pumping, accelerated sea-level rise, and other anthropic impacts, it is certain that the Mekong Delta will undergo large changes in the coming decades. These changes will threaten the very existence of the landform itself. The multiplicity of compounding drivers and lack of reliable data lead to large uncertainties in forecasting changes in the sediment budget of the Mekong Delta, its morphology, and the ecosystems and human livelihoods it supports. We compile information on key drivers affecting the sediment budget of the Mekong Delta and compare them to quantify the magnitude of effects from different drivers. We develop a set of likely scenarios for the future development of these drivers and quantify implications for the future of the Mekong Delta using a simplified model of the delta's geometry. If sediment supply to the delta is nearly completely cut off, as would be the case with full buildout of planned dams and current rates of sediment mining, and with continued groundwater pumping at current rates, our model forecasts that the delta will almost completely disappear by the end of this century due to increased rates of delta subsidence and rising sea levels. While local management cannot prevent global sea level rise, model results suggest that there are important management steps that could prolong the persistence of the delta ecosystem and the livelihoods it supports, including a reduction in ground water pumping and maintaining sediment connectivity between the basin and the delta.

  4. Average of delta: a new quality control tool for clinical laboratories.

    Science.gov (United States)

    Jones, Graham R D

    2016-01-01

    Average of normals is a tool used to control assay performance using the average of a series of results from patients' samples. Delta checking is a process of identifying errors in individual patient results by reviewing the difference from previous results of the same patient. This paper introduces a novel alternate approach, average of delta, which combines these concepts to use the average of a number of sequential delta values to identify changes in assay performance. Models for average of delta and average of normals were developed in a spreadsheet application. The model assessed the expected scatter of average of delta and average of normals functions and the effect of assay bias for different values of analytical imprecision and within- and between-subject biological variation and the number of samples included in the calculations. The final assessment was the number of patients' samples required to identify an added bias with 90% certainty. The model demonstrated that with larger numbers of delta values, the average of delta function was tighter (lower coefficient of variation). The optimal number of samples for bias detection with average of delta was likely to be between 5 and 20 for most settings and that average of delta outperformed average of normals when the within-subject biological variation was small relative to the between-subject variation. Average of delta provides a possible additional assay quality control tool which theoretical modelling predicts may be more valuable than average of normals for analytes where the group biological variation is wide compared with within-subject variation and where there is a high rate of repeat testing in the laboratory patient population. © The Author(s) 2015.

  5. Haematological and genetic features of delta beta-thalassaemia in Pakistan

    International Nuclear Information System (INIS)

    Ahmad, S.; Anwar, M.

    2006-01-01

    Objective: To describe the hematological and genetic features of delta beta-thalassaemia in Pakistani patients. Design: Descriptive case series. Place and Duration of Study: Department of Pathology, PNS Shifa, Karachi and Department of Hematology, Armed Forces Institute of Pathology, Rawalpindi, from January 1994 to April 2004. Patients and Methods: Thirteen individuals from six unrelated Pakistani families with a hematological diagnosis of delta beta-thalassaemia were studied. A brief clinical history, and the results of blood counts, absolute values, Hb-F, Hb-A/sub 2/, and hemoglobin electrophoresis were recorded. The DNA from each subject was first screened for the delta beta-thalassaemia mutations found in the Pakistani population. The samples were then screened for the Invl Del sup G/gamma(sup A/gamma delta beta). Results: The subjects included six heterozygote, six homozygotes and one compound heterozygote of delta beta and delta beta-thalassaemia. All heterozygote and 4/6 homozygotes were asymptomatic. One homo zygote had thalassaemia intermedia while another had transfusion dependent anemia. The mean Hb, TRBC, MCV, MCH, Hb-F and Hb-A/sub 2/ in delta beta-thalassaemia heterozygote were 11.6 g/dl, 5.37 x 1012/L, 70.9 fl, and 21.7 pg, 14% and 2.6% respectively. The same values in the four un transfused homo zygote were 10.6 g/dl, 5.34x1012/L, 69.211, and 20.8pg, 100% and 0% respectively. The mutation analysis revealed that all 13 individuals had the same Invl Del sup G/gamma(sup A/gamma delta beta). Conclusion: delta beta-thalassaemia is a rare disorder in Pakistan. Although the clinical picture is very mild its combination with delta beta-thalassaemia trait can produce a sever transfusion dependent thalassaemia. The DNA based diagnosis is possible in the prenatal as well as the postnatal period. (author)

  6. Assessing Niger-Delta Wetland Resources: A Case-Study of Mangrove Ecosystem

    Science.gov (United States)

    Anwan, R. H.; Ndimele, P. E.; Whenu, O. O.; Anetekhai, M. A.; Essien-Ibok, M. A.; Erondu, E. S.

    2016-02-01

    The Niger Delta is located in the Atlantic coast of Southern Nigeria and is the world's second largest delta with a coastline of about 450km. The Niger Delta region occupies a surface area of about 112,110km2, representing about 12% of Nigeria's total surface area. The Delta's environment can be broken down into four ecological zones: coastal barrier islands, mangrove swamp forests, freshwater swamps, and lowland rainforests. The mangrove swamps of Niger Delta, which is the largest delta in Africa constitute the dominant wetland ecosystem in the Niger Delta region and covers an area of about 1,900km2. Mangroves constitute important nurseries for fishes, crustaceans, sponges, algae and other invertebrates, and also acts as a sink, retaining pollutants from contaminated tidal water. The Niger Delta mangrove together with the creeks and rivers are a major source of food and livelihood for about 30 million people, which represents more than 17% of Nigeria's population. Other ecosystem services provided by this unique environment are flood control, ground water re-fill, reservoir of biodiversity, fuel wood, cultural values etc. This ecosystem also plays important role in climate change mitigation because of its high blue carbon sequestration potential. This is particularly important because of continuous gas flaring in Niger Delta from petroleum operations, which releases carbon dioxide among other gases into the atmosphere. This wetland is potentially a good site for ecotourism and also qualifies to be a world heritage site and Ramsar site if proper steps are taken. The benefits derivable from this fragile ecosystem are under severe threat by anthropogenic stressors. These include the installation of pipelines and seismic exploration by oil companies, crude oil pollution, deforestation, urbanization etc. This paper discusses the extent of depletion and loss of mangrove ecosystem in the Niger Delta region and the value of its goods and services.

  7. Entendiendo Delta desde las Humanidades

    Directory of Open Access Journals (Sweden)

    José Calvo Tello

    2016-05-01

    Full Text Available Stylometry is one of the research areas in greater development within Digital Humanities. However, few studies have worked until recently with texts in Spanish and even less so from Spanish-speaking countries. The aim of this paper is to present in Spanish, and without prior statistical knowledge from the reader, one of the main methods used in stylometry, the measure of textual distance Burrows’ Delta. This paper explains this measure using a very small corpus of proverbs and then checks the results in a corpus of Spanish novels. Both data and Python scripts are available to the community through GitHub, commented step by step so that you can play and visualize each step.

  8. EEHG at FLASH and DELTA

    Energy Technology Data Exchange (ETDEWEB)

    Molo, Robert; Hoener, Markus; Huck, Holger; Hacker, Kirsten; Khan, Shaukat; Schick, Andreas; Ungelenk, Peter; Zeinalzadeh, Maryam [Center for Synchrotron Radiation (DELTA), TU Dortmund University (Germany); Meulen, Peter van der; Salen, Peter [Stockholm University (Sweden); Angelova Hamberg, Gergana; Ziemann, Volker [Uppsala University (Sweden)

    2013-07-01

    The echo-enabled harmonic generation (EEHG) scheme utilizes two modulators with two magnetic chicanes in order to generate an electron density modulation with high harmonic content. In contrast to free-electron lasers (FEL) based on self-amplified spontaneous emission (SASE), the radiation of an EEHG FEL has better longitudinal coherence and is naturally synchronized with an external laser, which is advantageous for pump-probe applications. At the free-electron laser in Hamburg (FLASH), an EEHG experiment is currently under preparation. The short-pulse facility at DELTA (a 1.5-GeV synchrotron light source operated by the TU Dortmund University) based on coherent harmonic generation (CHG) will be upgraded using the EEHG technique in order to reach shorter wavelengths.

  9. Unexpected {delta}{sup 18}O and {delta}{sup 2}H Variability of Groundwater in the Eastern Paris Basin

    Energy Technology Data Exchange (ETDEWEB)

    Gourcy, L.; Petelet-Giraud, E. [BRGM Service EAU, Orleans (France)

    2013-07-15

    The Paris Basin covers about one-third of the total surface area of France. In 2009, two campaigns sampling 25 boreholes tapping Tertiary aquifers were carried out in the Basin. These aquifers are recharged at a similar altitude and the groundwater age is too young to have registered climate change. In the past, regional studies included the use of isotopes to understand groundwater origin and dynamics. Both {delta}{sup 18}O and {delta}{sup 2}H as well as ages (CFC/SF{sub 6)} and chemical components were determined in all collected samples. A noticeable stable isotope 'anomaly' appears in the south-western part of the Basin, where the average {delta}{sup 18}O and {delta}{sup 2}H values are more depleted and do not fit the pattern given by the continental effect in this area. A regional particularity of the spatial distribution of such isotopes in precipitation may be possible, but should be confirmed by additional work. (author)

  10. Integrated assessment of social and environmental sustainability dynamics in the Ganges-Brahmaputra-Meghna delta, Bangladesh

    Science.gov (United States)

    Nicholls, R. J.; Hutton, C. W.; Lázár, A. N.; Allan, A.; Adger, W. N.; Adams, H.; Wolf, J.; Rahman, M.; Salehin, M.

    2016-12-01

    Deltas provide diverse ecosystem services and benefits for their populations. At the same time, deltas are also recognised as one of the most vulnerable coastal environments, with a range of drivers operating at multiple scales, from global climate change and sea-level rise to deltaic-scale subsidence and land cover change. These drivers threaten these ecosystem services, which often provide livelihoods for the poorest communities in these regions. The imperative to maintain ecosystem services presents a development challenge: how to develop deltaic areas in ways that are sustainable and benefit all residents including the most vulnerable. Here we present an integrated framework to analyse changing ecosystem services in deltas and the implications for human well-being, focussing in particular on the provisioning ecosystem services of agriculture, inland and offshore capture fisheries, aquaculture and mangroves that directly support livelihoods. The framework is applied to the world's most populated delta, the Ganges-Brahmaputra-Meghna Delta within Bangladesh. The framework adopts a systemic perspective to represent the principal biophysical and socio-ecological components and their interaction. A range of methods are integrated within a quantitative framework, including biophysical and socio-economic modelling and analyses of governance through scenario development. The approach is iterative, with learning both within the project team and with national policy-making stakeholders. The analysis is used to explore physical and social outcomes for the delta under different scenarios and policy choices. We consider how the approach is transferable to other deltas and potentially other coastal areas.

  11. Influence of different organic fertilizers on quality parameters and the delta(15)N, delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of orange fruit (Citrus sinensis L. Osbeck).

    Science.gov (United States)

    Rapisarda, Paolo; Camin, Federica; Fabroni, Simona; Perini, Matteo; Torrisi, Biagio; Intrigliolo, Francesco

    2010-03-24

    To investigate the influence of different types of fertilizers on quality parameters, N-containing compounds, and the delta(15)N, delta(13)C, delta(2)H, delta (34)S, and delta(18)O values of citrus fruit, a study was performed on the orange fruit cv. 'Valencia late' (Citrus sinensis L. Osbeck), which was harvested in four plots (three organic and one conventional) located on the same farm. The results demonstrated that different types of organic fertilizers containing the same amount of nitrogen did not effect important changes in orange fruit quality parameters. The levels of total N and N-containing compounds such as synephrine in fruit juice were not statistically different among the different treatments. The delta(15)N values of orange fruit grown under fertilizer derived from animal origin as well as from vegetable compost were statistically higher than those grown with mineral fertilizer. Therefore, delta(15)N values can be used as an indicator of citrus fertilization management (organic or conventional), because even when applied organic fertilizers are of different origins, the natural abundance of (15)N in organic citrus fruit remains higher than in conventional ones. These treatments also did not effect differences in the delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of fruit.

  12. Rise and Fall of one of World's largest deltas; the Mekong delta in Vietnam

    Science.gov (United States)

    Minderhoud, P. S. J.; Eslami Arab, S.; Pham, H. V.; Erkens, G.; van der Vegt, M.; Oude Essink, G.; Stouthamer, E.; Hoekstra, P.

    2017-12-01

    The Mekong delta is the third's largest delta in the world. It is home to almost 20 million people and an important region for the food security in South East Asia. As most deltas, the Mekong delta is the dynamic result of a balance of sediment supply, sea level rise and subsidence, hosting a system of fresh and salt water dynamics. Ongoing urbanization, industrialization and intensification of agricultural practices in the delta, during the past decades, resulted in growing domestic, agricultural and industrial demands, and have led to a dramatic increase of fresh water use. Since the year 2000, the amount of fresh groundwater extracted from the subsurface increased by 500%. This accelerated delta subsidence as the groundwater system compacts, with current sinking rates exceeding global sea level rise up to an order of magnitude. These high sinking rates have greatly altered the sediment budget of the delta and, with over 50% of the Mekong delta surface elevated less than 1 meter above sea level, greatly increase vulnerability to flooding and storm surges and ultimately, permanent inundation. Furthermore, as the increasingly larger extractions rapidly reduce the fresh groundwater reserves, groundwater salinization subsequently increases. On top of that, dry season low-flows by the Mekong river cause record salt water intrusion in the delta's estuarine system, creating major problems for rice irrigation. We present the work of three years research by the Dutch-Vietnamese `Rise and Fall' project on land subsidence and salinization in both groundwater and surface water in the Vietnamese Mekong delta.

  13. Smilansky-Solomyak model with a delta '-interaction

    Czech Academy of Sciences Publication Activity Database

    Exner, Pavel; Lipovský, J.

    2018-01-01

    Roč. 382, č. 18 (2018), s. 1207-1213 ISSN 0375-9601 R&D Projects: GA ČR GA17-01706S Institutional support: RVO:61389005 Keywords : Smilansky-Solomyak model * delta '-interaction * spectral theory Subject RIV: BE - Theoretical Physics OBOR OECD: Atomic, molecular and chemical physics ( physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect) Impact factor: 1.772, year: 2016

  14. The delta-Sobolev approach for modeling solar spectral irradiance and radiance

    International Nuclear Information System (INIS)

    Xiang, Xuwu.

    1990-01-01

    The development and evaluation of a solar radiation model is reported, which gives irradiance and radiance results at the bottom and top of an atmosphere of specified optical depth for each of 145 spectral intervals from 0.29 to 4.05 microns. Absorption by water vapor, aerosols, ozone, and uniformly mixed gases; scattering by molecules and aerosols; and non-Lambertian surface reflectance are included in the model. For solving the radiative transfer equation, an innovative delta-Sobolev method is developed. It applies a delta-function modification to the conventional Sobolev solutions in a way analogous to the delta-Eddington method. The irradiance solution by the delta-Sobolev method turns out to be mathematically identical to the delta-Eddington approximation. The radiance solution by the delta-Sobolov method provides a convenient way to obtain the directional distribution pattern of the radiation transfer field, a feature unable to be obtained by most commonly used approximation methods. Such radiance solutions are also especially useful in models for satellite remote sensing. The model is tested against the rigorous Dave model, which solves the radiation transfer problem by the spherical harmonic method, an accurate but very time consuming process. Good agreement between the current model results and those of Dave's model are observed. The advantages of the delta-Sobolev model are simplicity, reasonable accuracy and capability for implementation on a minicomputer or microcomputer

  15. Delta Electroproduction in 12-C

    Energy Technology Data Exchange (ETDEWEB)

    McLauchlan, Steven [Univ. of Glasgow, Scotland (United Kingdom)

    2003-01-01

    The Δ-nucleus potential is a crucial element in the understanding of the nuclear system. Previous electroexcitation measurements in the delta region reported a Q2 dependence of the Δ mass indicating that this potential is dependent on the momentum of the Δ. Such a dependence is not observed for protons and neutrons in the nuclear medium. This thesis presents the experimental study of the electroexcitation of the Δ resonance in 12C, performed using the high energy electron beam at the Thomas Jefferson National Accelerator Facility, and the near 4π acceptance detector CLAS that enables the detection of the full reaction final state. Inclusive, semi inclusive, and exclusive cross sections were measured with an incident electron beam energy of 1.162GeV over the Q2 range 0.175-0.475 (GeV/c)2. A Q2 dependence of the Δ mass was only observed in the exclusive measurements indicating that the Δ-nucleus potential is affected by the momentum of the Δ.

  16. Mapping Soil Carbon in the Yukon Kuskokwim River Delta Alaska

    Science.gov (United States)

    Natali, S.; Fiske, G.; Schade, J. D.; Mann, P. J.; Holmes, R. M.; Ludwig, S.; Melton, S.; Sae-lim, N.; Jardine, L. E.; Navarro-Perez, E.

    2017-12-01

    Arctic river deltas are hotspots for carbon storage, occupying 10% of carbon stored in arctic permafrost. The Yukon Kuskokwim (YK) Delta, Alaska is located in the lower latitudinal range of the northern permafrost region in an area of relatively warm permafrost that is particularly vulnerable to warming climate. Active layer depths range from 50 cm on peat plateaus to >100 cm in wetland and aquatic ecosystems. The size of the soil organic carbon pool and vulnerability of the carbon in the YK Delta is a major unknown and is critically important as climate warming and increasing fire frequency may make this carbon vulnerable to transport to aquatic and marine systems and the atmosphere. To characterize the size and distribution of soil carbon pools in the YK Delta, we mapped the land cover of a 1910 km2 watershed located in a region of the YK Delta that was impacted by fire in 2015. The map product was the result of an unsupervised classification using the Weka K Means clustering algorithm implemented in Google's Earth Engine. Inputs to the classification were Worldview2 resolution optical imagery (1m), Arctic DEM (5m), and Sentinel 2 level 1C multispectral imagery, including NDVI, (10 m). We collected 100 soil cores (0-30 cm) from sites of different land cover and landscape position, including moist and dry peat plateaus, high and low intensity burned plateaus, fens, and drained lakes; 13 lake sediment cores (0-50 cm); and 20 surface permafrost cores (to 100 cm) from burned and unburned peat plateaus. Active layer and permafrost soils were analyzed for organic matter content, soil moisture content, and carbon and nitrogen pools (30 and 100 cm). Soil carbon content varied across the landscape; average carbon content values for lake sediments were 12% (5- 17% range), fens 26% (9-44%), unburned peat plateaus 41% (34-44%), burned peat plateaus 19% (7-34%). These values will be used to estimate soil carbon pools, which will be applied to the spatial extent of each

  17. Inhabiting the Delta: A Landscape Approach to Transformative Socio-Ecological Restoration

    Directory of Open Access Journals (Sweden)

    Brett Milligan

    2017-09-01

    Full Text Available doi: https://doi.org/10.15447/sfews.2017v15iss3art3Current legislation and plans for the Sacramento–San Joaquin Delta (Delta call for large-scale restoration of aquatic and terrestrial habitats, which will require significant changes in waterways, land uses, and cultural patterns. These re-made landscapes will be subject to a variety of new human uses, which Delta planning and adaptive management literature has yet to adequately consider. Failing to account for human uses and evolving place values can lead to diminished performance and public support for Delta restoration efforts. Our empirical study examined restored and naturalized Delta landscapes using an integrative landscape approach that seeks to reconcile multiple goals and land-use agendas that span ecological, social, economic, and political domains. The research design consisted of six overlapping methods that included a planning, policy, and law review specific to the Delta; surveys and interviews with approximately 100 land managers, scientists, land-owners, law-enforcement personnel, agency representatives, and Delta residents; nine case studies of restored and naturalized delta landscapes; GIS mapping; and extensive field work. Findings derived from the synthesis of these methods show that human uses of the Delta’s re-wilded landscapes are diverse and pervasive. Given the infrastructural and urbanized context of the region, these environments are subject to multiple and sometimes conflicting uses, perceptions, and place values. Though these myriad uses cannot be fully predicted or controlled (nor should they be, findings showed that more proactive and inclusive planning for human uses can encourage or discourage particular uses while also building constituency, support, and active engagement in ecological restoration efforts. We conclude that reconciling human uses with ecological recovery in the Delta will require a more localized, multi-functional, and creative approach to

  18. Economic Costs and Adaptations for Alternative Regulations of California's Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Stacy K. Tanaka

    2011-07-01

    Full Text Available Stacy K. Tanaka, Christina R. Connell–Buck, Kaveh Madani, Josue Medellín-Azuara, Jay R. Lund, and Ellen Hanakdoi: http://dx.doi.org/10.15447/sfews.2014v9iss2art4Water exports from California’s Sacramento–San Joaquin Delta are an environmental concern because they reduce net outflows of fresh water from the Delta, and can entrain fish and disrupt flows within the Delta. If exports were no longer pumped from within the Delta, the regulatory issue becomes one of maintaining appropriate flows into and out of the Delta. This paper presents the results of two sets of hydro-economic optimization modeling runs, which were developed to represent a range of modified Delta operations and their economic and operational effects on California’s water supply system. The first set of runs represents decreasing export capacity from the Delta. The second set increases minimum net Delta outflow (MNDO requirements. The hydro-economic model seeks the least–cost statewide water management scheme for water supply, including a wide range of resources and water management options. Results show that reducing exports or increasing MNDO requirements increase annual average statewide water scarcity, scarcity costs, and operating costs (from greater use of desalination, wastewater recycling, water treatment, and pumping. Effects of reduced exports are especially concentrated in agricultural communities in the southern Central Valley because of their loss of access to overall water supply exports and their ability to transfer remaining water to southern California. Increased outflow requirements increase water scarcity and associated costs throughout California. For an equivalent amount of average Delta outflows, statewide costs increase more rapidly when exports alone are reduced than when minimum outflow requirements are increased and effects are more widely distributed statewide.

  19. Legal Delta Boundary, 2001, DWR [ds586

    Data.gov (United States)

    California Natural Resource Agency — The original topographic maps containing the drawn delta border were scanned from the Department of Water Resources. Images were registered to 1:24,000 USGS DRG's in...

  20. sheltered creeks in Niger Delta, Nigeria

    African Journals Online (AJOL)

    user

    2015-03-18

    Mar 18, 2015 ... 273 and 115,000 barrels, respectively, making the delta. *Corresponding author. .... content was transferred to savillex digestion bombs and concen- trated hydrochloric ... metals (Zn, Pb and Cu) by flame atomic absorption.

  1. South Local Government Area, Delta S

    African Journals Online (AJOL)

    ADOWIE PERE

    environs, Aniocha- South Local Government Area of Delta State, Nigeria was carried out with a view to determining the ... supply for physical industrial development to achieve maximum human .... the Schlumberger O' Neil software package.

  2. Delta-nucleus dynamics: proceedings of symposium

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T.S.H.; Geesaman, D.F.; Schiffer, J.P. (eds.)

    1983-10-01

    The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta ..delta..(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe ..delta..-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented. (WHK)

  3. Damped Oscillator with Delta-Kicked Frequency

    Science.gov (United States)

    Manko, O. V.

    1996-01-01

    Exact solutions of the Schrodinger equation for quantum damped oscillator subject to frequency delta-kick describing squeezed states are obtained. The cases of strong, intermediate, and weak damping are investigated.

  4. On the origin of delta spots

    International Nuclear Information System (INIS)

    Tang, F.

    1983-01-01

    Mount Wilson sunspot drawings from 1966 through 1980 were used in conjunction with Hα filtergrams from Big Bear Solar Observatory to examine the origin of delta spots, spots with bipolar umbrae within one penumbra. Of the six cases we studied, five were formed by the union of non-paired spots. They are either shoved into one another by two neighboring growing bipoles or by a new spot born piggy-back style on an existing spot of opposite polarity. Proper motions of the growing spots take on curvilinear paths around one another to avoid a collision. This is the shear motion observed in delta spots (Tanaka, 1979). In the remaining case, the delta spot was formed by spots that emerged as a pair. Our findings indicate no intrinsic differences in the formation or the behavior between delta spots of normal magnetic configuration. (orig.)

  5. 2016 Rose Ojowhoh Delta State Polytechnic, Ozoro

    African Journals Online (AJOL)

    OJOHWOH ROSE

    The study examined staff development and library services in academic libraries in Bayelsa and Delta States. ... academic libraries, whose responsibility will be to cater for the development of staff in all ramifications. ..... Human resource.

  6. AMNESTY IN THE NIGER DELTA: VERTICAL MOVEMENT ...

    African Journals Online (AJOL)

    OLAWUYI

    federal government, the Niger Delta communities claim that they are entitled to ... instability, macroeconomic challenges, inconsistent policy regimes to ..... continues they cannot threaten the stability of the country nor affect its continued.

  7. Astrobee Periodic Technical Review (PTR) Delta 3

    Science.gov (United States)

    Provencher, Christopher; Smith, Marion F.; Smith, Ernest Everett; Bualat, Maria Gabriele; Barlow, Jonathan Spencer

    2017-01-01

    Astrobee is a free flying robot for the inside of the International Space Station (ISS). The Periodic Technical Review (PTR) delta 3 is the final design review of the system presented to stakeholders.

  8. Community structure of spiders in coastal habitats of a Mediterranean delta region (Nestos Delta, NE Greece

    Directory of Open Access Journals (Sweden)

    S. Buchholz

    2009-01-01

    Full Text Available (pp 101-115Habitat zonation and ecology of spider assemblages have been poorly studied in Mediterranean ecosystems. A first analysis of spider assemblages in coastal habitats in the east Mediterranean area is presented. The study area is the 250 km² Nestos Delta, located in East Macedonia in the North-East of Greece. Spiders were caught in pitfall traps at 17 sites from the beginning of April to the end of June 2004. Nonparametric estimators were used to determine species richness and alpha diversity. Ordination analysis (redundancy analysis indicated four clearly separable spider species groups (salt meadows, dunes, mea-dows and floodplain forests, along a soil salinity and moisture gradient. Based on these results we discuss the habitat preferences of these spiders and include the first ecological data on several species.

  9. A novel mouse PKC{delta} splice variant, PKC{delta}IX, inhibits etoposide-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung D. [School of Biological Sciences, University of Ulsan, Ulsan (Korea, Republic of); Seo, Kwang W. [Department of Internal Medicines, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of); Lee, Eun A.; Quang, Nguyen N. [School of Biological Sciences, University of Ulsan, Ulsan (Korea, Republic of); Cho, Hong R. [Department of Surgery, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of); Biomedical Research Center, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of); Kwon, Byungsuk, E-mail: bskwon@mail.ulsan.as.kr [School of Biological Sciences, University of Ulsan, Ulsan (Korea, Republic of); Biomedical Research Center, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of)

    2011-07-01

    Highlights: {yields} A novel PKC{delta} isoform, named PKC{delta}IX, that lacks the C1 domain and the ATP-binding site is ubiquitously expressed. {yields} PKC{delta}IX inhibits etoposide-induced apoptosis. {yields} PKC{delta}IX may function as an endogenous dominant negative isoform for PKC{delta}. -- Abstract: Protein kinase C (PKC) {delta} plays an important role in cellular proliferation and apoptosis. The catalytic fragment of PKC{delta} generated by caspase-dependent cleavage is essential for the initiation of etoposide-induced apoptosis. In this study, we identified a novel mouse PKC{delta} isoform named PKC{delta}IX (Genebank Accession No. (HQ840432)). PKC{delta}IX is generated by alternative splicing and is ubiquitously expressed, as seen in its full-length PKC{delta}. PKC{delta}IX lacks the C1 domain, the caspase 3 cleavage site, and the ATP binding site but preserves an almost intact c-terminal catalytic domain and a nuclear localization signal (NLS). The structural characteristics of PKC{delta}IX provided a possibility that this PKC{delta} isozyme functions as a novel dominant-negative form for PKC{delta} due to its lack of the ATP-binding domain that is required for the kinase activity of PKC{delta}. Indeed, overexpression of PKC{delta}IX significantly inhibited etoposide-induced apoptosis in NIH3T3 cells. In addition, an in vitro kinase assay showed that recombinant PKC{delta}IX protein could competitively inhibit the kinase activity of PKC{delta}. We conclude that PKC{delta}IX can function as a natural dominant-negative inhibitor of PKC{delta}in vivo.

  10. Delta infection evidenced by radioimmunoanalysis in selected collectives

    Energy Technology Data Exchange (ETDEWEB)

    Kselikova, M; Horejsi, J; Urbankova, J

    1987-01-01

    The presence of the Delta agent within the population was tested by means of the Delta-antibody radioimmunoassay using competitive kits of the firms ABBOTT (ABBOTT-ANTI-DELTA) and SORIN (AB-DELTAK). The Delta-antibody was found in 3.2% HBV patients, 5% HBsAg carriers, and in 20.8% of specific anti-Hbs-immunoglobulin. In hemophiliacs and blood donors no Delta-antibody was seen.

  11. Delta infection evidenced by radioimmunoanalysis in selected collectives

    International Nuclear Information System (INIS)

    Kselikova, M.; Horejsi, J.; Urbankova, J.

    1987-01-01

    The presence of the Delta agent within the population was tested by means of the Delta-antibody radioimmunoassay using competitive kits of the firms ABBOTT (ABBOTT-ANTI-DELTA) and SORIN (AB-DELTAK). The Delta-antibody was found in 3.2% HBV patients, 5% HBsAg carriers, and in 20.8% of specific anti-Hbs-immunoglobulin. In hemophiliacs and blood donors no Delta-antibody was seen. (author)

  12. Preparing the Dutch delta for future droughts: model based support in the national Delta Programme

    Science.gov (United States)

    ter Maat, Judith; Haasnoot, Marjolijn; van der Vat, Marnix; Hunink, Joachim; Prinsen, Geert; Visser, Martijn

    2014-05-01

    Keywords: uncertainty, policymaking, adaptive policies, fresh water management, droughts, Netherlands, Dutch Deltaprogramme, physically-based complex model, theory-motivated meta-model To prepare the Dutch Delta for future droughts and water scarcity, a nation-wide 4-year project, called Delta Programme, is established to assess impacts of climate scenarios and socio-economic developments and to explore policy options. The results should contribute to a national adaptive plan that is able to adapt to future uncertain conditions, if necessary. For this purpose, we followed a model-based step-wise approach, wherein both physically-based complex models and theory-motivated meta-models were used. First step (2010-2011) was to make a quantitative problem description. This involved a sensitivity analysis of the water system for drought situations under current and future conditions. The comprehensive Dutch national hydrological instrument was used for this purpose and further developed. Secondly (2011-2012) our main focus was on making an inventory of potential actions together with stakeholders. We assessed efficacy, sell-by date of actions, and reassessed vulnerabilities and opportunities for the future water supply system if actions were (not) taken. A rapid assessment meta-model was made based on the complex model. The effects of all potential measures were included in the tool. Thirdly (2012-2013), with support of the rapid assessment model, we assessed the efficacy of policy actions over time for an ensemble of possible futures including sea level rise and climate and land use change. Last step (2013-2014) involves the selection of preferred actions from a set of promising actions that meet the defined objectives. These actions are all modeled and evaluated using the complex model. The outcome of the process will be an adaptive management plan. The adaptive plan describes a set of preferred policy pathways - sequences of policy actions - to achieve targets under

  13. Houtman Abrolhos Isotope (delta 18O, delta 13C) Data for 1795 to 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — DESCRIPTION: VARIABLES AND UNITS: Column #1: core depth in mm Column #2: delta C-13 vs V-PDB Column #3: delta O-18 vs V-PDB Column #4: assigned date in years A.D....

  14. The Enabling Delta Life Initiative - Global Programme of Action on Deltas - Programme description

    NARCIS (Netherlands)

    Driel, van W.F.; Skyllerstedt, S.; Wosten, J.H.M.

    2014-01-01

    Being ‘hotspots’ of human activity with generally high population densities, deltas are vulnerable to changes induced by a range of driving forces, both natural and anthropogenic. In addition to already existing challenges, uncertainty of the possible impacts of climate change, low lying deltas

  15. Challenges Facing the Sacramento–San Joaquin Delta: Complex, Chaotic, or Simply Cantankerous?

    Directory of Open Access Journals (Sweden)

    Samuel N. Luoma

    2015-09-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2015v13iss3art7Freshwater is a scarce and precious resource in California; its overall value is being made clear by the current severe drought. The Sacramento–San Joaquin Delta is a critical node in a complex water supply system that extends throughout much of the western U.S. wherein demand is exceeding supply. The Delta also underpins a major component of the U.S. economy, helps feed a substantial part of the country, is a unique and valuable ecological resource, and is a place with a rich cultural heritage. Sustaining the Delta is a problem that manifests itself in many dimensions including the physical structure of the Delta, the conflicting demands for water, changing water quality, rapidly evolving ecological character, and high institutional complexity. The problems of the California Delta are increasingly complex, sometimes chaotic, and always contentious. There is general agreement that current management will sustain neither the Delta ecosystem nor high-quality water exports, as required under the Delta Reform Act, so there is a renewed urgency to address all dimensions of the problem aggressively. Sustainable management of the Delta ecosystem and California’s highly variable water supply, in the face of global climate change, will require bold political decisions that include adjustments to the infrastructure but give equal emphasis to chronic overuse and misuse of water, promote enhanced efficiency of water use, and facilitate new initiatives for ecosystem recovery. This new approach will need to be underpinned by collaborative science that supports ongoing evaluation and re-adjustment of actions. Problems like the Delta are formally “wicked" problems that cannot be “solved” in the traditional sense, but they can be managed with appropriate knowledge and flexible institutions. Where possible, it is advisable to approach major actions incrementally, with an eye toward avoiding

  16. Data on macrofungal diversity from the Danube Delta iosphere Reserve

    Directory of Open Access Journals (Sweden)

    SZASZ Balazs

    2017-12-01

    Full Text Available Despite de fact that the Danube Delta has a great biodiversity with more than 2300 plants and more than 4000 animals registered (http://www.ddbra.ro/rezervatia/deltadunarii/biodiversitate, the study of macromycetes is rather scanty, and the number of macromycetes species found so far in the Reserve is 58. As a result of the mycological investigations done by the authors in 2016 May 7-8 and October 21-22 in the Danube Delta Biosphere Reserve in the Letea Forest, Caraorman Forest and at the forest district’s former premises near C.A. Rosetti, the list of the recorded 130 species is presented, out of which 110 species are documented for the first time in the Danube Delta Biosphere Reserve (DDBR. The number of the macrofungi species that occur in the formentioned Reserve - including the buffer zone from Enisala - has grown to 168. Based on the red list of the romanian macromycetes (Tănase and Pop, 2005 we have found three species in the near threatened category (NT: Helvella acetabulum, Morchella esculenta and Pluteus petasatus, and one species in the vulnerable category (VU: Myriostoma coliforme. A short survey from 1932 to 2012 about the former mycological studies concerning the DDBR is presented, and the nomenclaturally updated list of the 38 species not found by us, but present in the DDBR is given.

  17. Holocene evolution of a wave-dominated fan-delta: Godavari delta, India

    Science.gov (United States)

    Saito, Y.; Nageswara Rao, K.; Nagakumar, K.; Demudu, G.; Rajawat, A.; Kubo, S.; Li, Z.

    2013-12-01

    The Godavari delta is one of the world's largest wave-dominated deltas. The Godavari River arises in the Western Ghats near the west coast of India and drains an area of about 3.1x10^5 km^2, flowing about 1465 km southeast across the Indian peninsula to the Bay of Bengal. The Godavari delta consists of a gentle seaward slope from its apex (12 m elevation) at Rajahmundry and a coastal beach-ridge plain over a distance of about 75 km and covers ~5200 km^2 as a delta plain. The river splits into two major distributary channels, the Gautami and the Vasishta, at a barrage constructed in the mid-1800s. The coastal environment of the deltaic coast is microtidal (~1 m mean tidal range) and wave-dominated (~1.5 m mean wave height in the June-September SW monsoon season, ~0.8 m in the NE monsoon season). Models of the Holocene evolution of the Godavari delta have changed from a zonal progradation model (e.g. Nageswara Rao & Sadakata, 1993) to a truncated cuspate delta model (Nageswara Rao et al., 2005, 2012). Twelve borehole cores (340 m total length), taken in the coastal delta plain during 2010-2013, yielded more than 100 C-14 dates. Sediment facies and C-14 dates from these and previous cores and remote-sensing data support a new delta evolution model. The Holocene coastal delta plain is divided into two parts by a set of linear beach ridges 12-14 km landward from the present shoreline in the central part of the delta. The location of the main depocenter (lobe) has shifted during the Holocene from 1) the center to 2) the west, 3) east, 4) center, 5) west, and 6) east. The linear beach ridges separate the first three from the last three stages. These lobe shifts are controlled by river channel shifts near the apex. Just as the current linear shoreline of the central part of the delta and the concave-up nearshore topography are the result of coastal erosion of a cuspate delta, the linear beach ridges indicate a former eroded shoreline. An unconformity within the deltaic

  18. QCD in the {delta}-regime

    Energy Technology Data Exchange (ETDEWEB)

    Bietenholz, W. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Ciencias Nucleares; Cundy, N. [Seoul National Univ. (Korea, Republic of). Lattice Gauge Theory Research Center; Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Horsley, R.; Zanotti, J.M. [Edinburgh Univ. (United Kingdom). School of Physics; Nakamura, Y. [Tsukuba Univ., Ibaraki (Japan). Center for Computational Sciences; Pleiter, D. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Schierholz, G. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-03-15

    The {delta}-regime of QCD is characterised by light quarks in a small spatial box, but a large extent in (Euclidean) time. In this setting a specific variant of chiral perturbation theory - the {delta}-expansion - applies, based on a quantum mechanical treatment of the quasi onedimensional system. In particular, for vanishing quark masses one obtains a residual pion mass M{sup R}{sub {pi}}, which has been computed to the third order in the {delta}-expansion. A comparison with numerical measurements of this residual mass allows for a new determination of some Low Energy Constants, which appear in the chiral Lagrangian. We first review the attempts to simulate 2-flavour QCD directly in the {delta}-regime. This is very tedious, but results compatible with the predictions for M{sup R}{sub {pi}} have been obtained. Then we show that an extrapolation of pion masses measured in a larger volume towards the {delta}-regime leads to good agreement with the theoretical predictions. From those results, we also extract a value for the (controversial) sub-leading Low Energy Constant anti l{sub 3}. (orig.)

  19. delta-EF1 is a negative regulator of Ihh in the developing growth plate.

    Science.gov (United States)

    Bellon, Ellen; Luyten, Frank P; Tylzanowski, Przemko

    2009-11-30

    Indian hedgehog (Ihh) regulates proliferation and differentiation of chondrocytes in the growth plate. Although the biology of Ihh is currently well documented, its transcriptional regulation is poorly understood. delta-EF1 is a two-handed zinc finger/homeodomain transcriptional repressor. Targeted inactivation of mouse delta-EF1 leads to skeletal abnormalities including disorganized growth plates, shortening of long bones, and joint fusions, which are reminiscent of defects associated with deregulation of Ihh signaling. Here, we show that the absence of delta-EF1 results in delayed hypertrophic differentiation of chondrocytes and increased cell proliferation in the growth plate. Further, we demonstrate that delta-EF1 binds to the putative regulatory elements in intron 1 of Ihh in vitro and in vivo, resulting in down-regulation of Ihh expression. Finally, we show that delta-EF1 haploinsufficiency leads to a postnatal increase in trabecular bone mass associated with enhanced Ihh expression. In summary, we have identified delta-EF1 as an in vivo negative regulator of Ihh expression in the growth plate.

  20. TAF6delta controls apoptosis and gene expression in the absence of p53.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Wilhelm

    Full Text Available BACKGROUND: Life and death decisions of metazoan cells hinge on the balance between the expression of pro- versus anti-apoptotic gene products. The general RNA polymerase II transcription factor, TFIID, plays a central role in the regulation of gene expression through its core promoter recognition and co-activator functions. The core TFIID subunit TAF6 acts in vitro as an essential co-activator of transcription for the p53 tumor suppressor protein. We previously identified a splice variant of TAF6, termed TAF6delta that can be induced during apoptosis. METHODOLOGY/PRINCIPAL FINDINGS: To elucidate the impact of TAF6delta on cell death and gene expression, we have employed modified antisense oligonucleotides to enforce expression of endogenous TAF6delta. The induction of endogenous TAF6delta triggered apoptosis in tumor cell lines, including cells devoid of p53. Microarray experiments revealed that TAF6delta activates gene expression independently of cellular p53 status. CONCLUSIONS: Our data define TAF6delta as a pivotal node in a signaling pathway that controls gene expression programs and apoptosis in the absence of p53.

  1. Effects of climate change on evapotranspiration over the Okavango Delta water resources

    Science.gov (United States)

    Moses, Oliver; Hambira, Wame L.

    2018-06-01

    In semi-arid developing countries, most poor people depend on contaminated surface or groundwater resources since they do not have access to safe and centrally supplied water. These water resources are threatened by several factors that include high evapotranspiration rates. In the Okavango Delta region in the north-western Botswana, communities facing insufficient centrally supplied water rely mainly on the surface water resources of the Delta. The Delta loses about 98% of its water through evapotranspiration. However, the 2% remaining water rescues the communities facing insufficient water from the main stream water supply. To understand the effects of climate change on evapotranspiration over the Okavango Delta water resources, this study analysed trends in the main climatic parameters needed as input variables in evapotranspiration models. The Mann Kendall test was used in the analysis. Trend analysis is crucial since it reveals the direction of trends in the climatic parameters, which is helpful in determining the effects of climate change on evapotranspiration. The main climatic parameters required as input variables in evapotranspiration models that were of interest in this study were wind speeds, solar radiation and relative humidity. Very little research has been conducted on these climatic parameters in the Okavango Delta region. The conducted trend analysis was more on wind speeds, which had relatively longer data records than the other two climatic parameters of interest. Generally, statistically significant increasing trends have been found, which suggests that climate change is likely to further increase evapotranspiration over the Okavango Delta water resources.

  2. Large old trees influence patterns of delta13C and delta15N in forests.

    Science.gov (United States)

    Weber, Pascale; Bol, Roland; Dixon, Liz; Bardgett, Richard D

    2008-06-01

    Large old trees are the dominant primary producers of native pine forest, but their influence on spatial patterns of soil properties and potential feedback to tree regeneration in their neighbourhood is poorly understood. We measured stable isotopes of carbon (delta(13)C) and nitrogen (delta(15)N) in soil and litter taken from three zones of influence (inner, middle and outer zone) around the trunk of freestanding old Scots pine (Pinus sylvestris L.) trees, to determine the trees' influence on below-ground properties. We also measured delta(15)N and delta(13)C in wood cores extracted from the old trees and from regenerating trees growing within their three zones of influence. We found a significant and positive gradient in soil delta(15)N from the inner zone, nearest to the tree centre, to the outer zone beyond the tree crown. This was probably caused by the higher input of (15)N-depleted litter below the tree crown. In contrast, the soil delta(13)C did not change along the gradient of tree influence. Distance-related trends, although weak, were visible in the wood delta(15)N and delta(13)C of regenerating trees. Moreover, the wood delta(15)N of small trees showed a weak negative relationship with soil N content in the relevant zone of influence. Our results indicate that large old trees control below-ground conditions in their immediate surroundings, and that stable isotopes might act as markers for the spatial and temporal extent of these below-ground effects. John Wiley & Sons, Ltd

  3. Abraham Reef Stable Isotope Data (delta 13C, delta 18O, delta 14C) for 1635-1957

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site: Abraham Reef, 22ó 06'S, 153ó 00'E, Porites australiensus, Radiocarbon (delta 14C) and Stable Isotope (del 18O and del 13C) results from bi-annual samples from...

  4. DeltaProt: a software toolbox for comparative genomics

    Directory of Open Access Journals (Sweden)

    Willassen Nils P

    2010-11-01

    Full Text Available Abstract Background Statistical bioinformatics is the study of biological data sets obtained by new micro-technologies by means of proper statistical methods. For a better understanding of environmental adaptations of proteins, orthologous sequences from different habitats may be explored and compared. The main goal of the DeltaProt Toolbox is to provide users with important functionality that is needed for comparative screening and studies of extremophile proteins and protein classes. Visualization of the data sets is also the focus of this article, since visualizations can play a key role in making the various relationships transparent. This application paper is intended to inform the reader of the existence, functionality, and applicability of the toolbox. Results We present the DeltaProt Toolbox, a software toolbox that may be useful in importing, analyzing and visualizing data from multiple alignments of proteins. The toolbox has been written in MATLAB™ to provide an easy and user-friendly platform, including a graphical user interface, while ensuring good numerical performance. Problems in genome biology may be easily stated thanks to a compact input format. The toolbox also offers the possibility of utilizing structural information from the SABLE or other structure predictors. Different sequence plots can then be viewed and compared in order to find their similarities and differences. Detailed statistics are also calculated during the procedure. Conclusions The DeltaProt package is open source and freely available for academic, non-commercial use. The latest version of DeltaProt can be obtained from http://services.cbu.uib.no/software/deltaprot/. The website also contains documentation, and the toolbox comes with real data sets that are intended for training in applying the models to carry out bioinformatical and statistical analyses of protein sequences. Equipped with the new algorithms proposed here, DeltaProt serves as an auxiliary

  5. Deltas on the move. Making deltas cope with the effects of climate change

    International Nuclear Information System (INIS)

    Reker, J.; Van Winden, A.; Braakhekke, W.; Vermaat, J.; Eleveld, M.; Janssen, R.; De Reus, N.; Omzigt, N.

    2006-01-01

    This scoping study is the first phase of a study aimed at: (a) providing knowledge on the potential of a system-based approach to deal with the effects of climate change as an alternative for the more traditional technical measures such as dams, dikes and surge barriers. This should be shown for both rich and poor countries and should address hydrological, ecological as well as socio-economic aspects; and (b) identifying the potential to market these results worldwide. To reach these objectives four research steps are defined: (1) to make an inventory of deltas: their vulnerability to the effects of climate change; (2) development of indicators for successful use of a system-based approach; (3) to provide an overview of the potential of soft measures for these deltas; (4) to select a number of deltas with potential for marketing system-based measures and the development of strategies to link economic and ecological objectives. This scoping study addresses step 1 only. The results from step 1 will be used as a starting point for steps 2 and 3. The outputs of this scoping study are threefold: a background report (this report); a flyer with a brief description of the findings; a website with information on delta's and how these may be affected by climate change. The scoping study will roughly outline which deltas are still functioning in a more or less natural manner - or could be (re)developed in that direction - and thus would be good candidates for a system-based approach. Chapter 2 gives a description of the geomorphological and ecological processes in a delta. In addition, those aspects of climate change that can have an effect on deltas are described. The third chapter deals with human interventions in deltas and whether or not they fit within a system-based approach. In a system-based approach, as presented in Chapter 4, natural processes are given free reign where possible. Chapter 5 shows how available data on deltas could be used in such a system

  6. Modeling Anthropogenic Impact on Sediment Balance and Relative Sea-Level Rise in Contemporary and Future Deltas

    Science.gov (United States)

    Tessler, Z. D.; Vorosmarty, C. J.; Overeem, I.; Syvitski, J. P.

    2017-12-01

    Modern deltas are dependent on human-mediated freshwater and sediment fluxes. Changes to these fluxes impact delta biogeophysical functioning, and affect the long-term sustainability of these landscapes for both human and natural systems. Here we present contemporary estimates of long-term mean sediment balance and relative sea-level rise across 46 global deltas. We model ongoing development and scenarios of future water resource management and hydropower infrastructure in upstream river basins to explore how changing sediment fluxes impact relative sea-level in coastal delta systems. Model results show that contemporary sediment fluxes, anthropogenic drivers of land subsidence, and sea-level rise result in relative sea-level rise rates in deltas that average 6.8 mm/year. Currently planned or under-construction dams can be expected to increase rates of relative sea-level rise on the order of 1 mm/year. Some deltas systems, including the Magdalena, Orinoco, and Indus, are highly sensitive to future impoundment of river basins, with RSLR rates increasing up to 4 mm/year in a high-hydropower-utilization scenario. Sediment fluxes may be reduced by up to 60% in the Danube and 21% in the Ganges-Brahmaputra-Megnha if all currently planned dams are constructed. Reduced sediment retention on deltas due to increased river channelization and local flood controls increases RSLR on average by nearly 2 mm/year. Long-term delta sustainability requires a more complete understanding of how geophysical and anthropogenic change impact delta geomorphology. Strategies for sustainable delta management that focus on local and regional drivers of change, especially groundwater and hydrocarbon extraction and upstream dam construction, can be highly impactful even in the context of global climate-induced sea-level rise.

  7. The Economic Dimensions of the Niger Delta Ethnic Conflicts (Pp ...

    African Journals Online (AJOL)

    User

    1970, the price of international oil stepped upwards following the Middle. Eastern Yom Kippur .... Over the years, the pleas of the Niger Delta people for accommodation are ignored or .... In a labour surplus region like the Niger Delta, budget.

  8. Conceptualizing delta forms and processes in Arctic coastal environments

    DEFF Research Database (Denmark)

    Bendixen, Mette; Kroon, Aart

    2017-01-01

    Climate warming in the Arctic directly causes two opposite changes in Arctic coastal systems: increased melt-water discharge through rivers induces extra influx of sediments and extended open water season increases wave impact which reworks and erodes the shores. A shoreline change analysis along...... and popped up as hotspots. The Tuapaat delta and Skansen delta showed large progradation rates (1.5 and 7m/yr) and migration of the adjacent barriers and spits. The dynamic behavior at the delta mouths was mainly caused by classic delta channel lobe switching at one delta (Tuapaat), and by a breach...... of the fringing spit at the other delta (Skansen). The longshore and cross-shore transports are responsible for reworking the sediment with a result of migrating delta mouths and adjacent subaqueous mouth bars. Seaward progradation of the deltas is limited due to the steep nature of the bathymetry in Disko Bay...

  9. Experiences with delta compression of data produced by DIII

    International Nuclear Information System (INIS)

    Henline, P.A.

    1986-01-01

    The amount of data collected for each tokamak experimental shot is rapidly increasing. This is caused by many factors, including more diagnostic experiments, reduced cost of electronics hardware (especially memory), and longer plasma duration. The design goal for the DIII-D tokamak is 25 Mbytes of data per shot. In order to store the shot data as one logical unit, the delta compression algorithm, as it was implemented at ORNL by E. Blair, is being used. Statistics on compression factors, times, and general usage will be presented for actual DIII data. Data for 8-, 10-, and 12-bit digitizers will be highlighted since this hardware is common to most sites

  10. Binding energies of two deltas bound states

    International Nuclear Information System (INIS)

    Sato, Hiroshi; Saito, Koichi.

    1982-06-01

    Bound states of the two-deltas system are investigated by employing the realistic one boson exchange potential. It is found that there exist many bound states in each isospin channel and also found that the tensor interaction plays important role in producing these bound states. Relationship between these bound states and dibaryon resonances is discussed. (J.P.N.)

  11. Solubility of hydrogen in delta iron

    International Nuclear Information System (INIS)

    Shapovalov, V.I.; Trofimenko, V.V.

    1979-01-01

    The solubility of hydrogen in iron (less than 0.002 % impurities) at temperatures of 800-1510 deg C and a pressure of 100 atm was measured. The heat of solution of hydrogen in delta-Fe, equal to 73 kJ/g-atom, is by far greater than the corresponding values for α- and γ-Fe

  12. Managing flood risks in the Mekong Delta

    NARCIS (Netherlands)

    Hoang, Long Phi; Biesbroek, Robbert; Tri, Van Pham Dang; Kummu, Matti; Vliet, van Michelle T.H.; Leemans, Rik; Kabat, Pavel; Ludwig, Fulco

    2018-01-01

    Climate change and accelerating socioeconomic developments increasingly challenge flood-risk management in the Vietnamese Mekong River Delta—a typical large, economically dynamic and highly vulnerable delta. This study identifies and addresses the emerging challenges for flood-risk management.

  13. Bioluminescent hydrocarbonclastic bacteria of the Niger Delta ...

    African Journals Online (AJOL)

    Utilization of three petroleum hydrocarbons (Mobil SAE 40 Engine Oil, Diesel and Bonny light Crude Oil) by four bioluminescent bacteria (Vibrio harveyi, V. fisheri, Photobacterium leiognathi and P. Phosphoreum isolated from the Bonny estuary in the Niger Delta, Nigeria was investigated. Microbial utilization was monitored ...

  14. The Delta Team: Empowering Adolescent Girls.

    Science.gov (United States)

    Hood, Marian White

    1994-01-01

    In response to adolescent girls' concerns about teen violence, rumors, grooming, careers, and equity, four women teachers and a woman administrator at a Maryland middle school developed the Delta Program. The program provides positive learning experiences, teaches social skills and conflict management techniques, empowers girls through mentoring…

  15. delta. -isobars and photodisintegration at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Suzumura, Jun-ichi; Futami, Yasuhiko [Science Univ. of Tokyo, Noda, Chiba (Japan). Faculty of Science and Technology

    1982-12-01

    The dynamics of the peak considered to be due to the two-nucleon process in the reaction /sup 9/Be(gamma, p) anything is investigated with the quasi-deuteron model. We show that the process is dominated by a two-nucleon mechanism with pion and rho-meson exchange through virtual delta-isobar formation (author).

  16. Contaminant Effects on California Bay–Delta Species and Human Health

    Directory of Open Access Journals (Sweden)

    Stephanie Fong

    2016-12-01

    Full Text Available doi: https://doi.org/10.15447/sfews.2016v14iss4art5Many contaminants in the California Bay–Delta (Bay–Delta exceed regulatory standards, affect aquatic species, and potentially affect human health. Recent studies provide multiple lines of evidence that contaminants affect species of concern in the Bay–Delta (e.g., the decline of several important fish species referred to as the “Pelagic Organism Decline” or POD. Contaminants occur as dynamic complex mixtures and exert effects at multiple levels of biological organization. Multiple chemicals impair processes at cellular and physiological levels (measured as growth, development, and behavior abnormalities, and when viability and reproductive output are affected, populations are affected. As an important example, the population decline of the endangered Delta Smelt (Hypomesus transpacificus is significantly associated with multiple stressors, including insecticide use. New analyses presented in this paper show significant correlations between pyrethroid use and declining abundance of POD fish species. Water sampled from the Bay–Delta causes multiple deleterious effects in fish, and Delta Smelt collected from the Bay–Delta exhibit contaminant effects. Fish prey items are also affected by contaminants; this may have an indirect effect on their populations. Co-occurrence with thermal changes or disease can exacerbate contaminant effects. Contaminants also pose threats to human health via consumption of fish and shellfish, drinking water, and contact recreation, in particular, mercury, cyanobacteria toxins, disinfection byproducts, pathogens, pesticides, and pharmaceuticals and personal care products. The role of contaminants in the decline of Bay–Delta species is difficult to accurately assess in a complex, dynamic system. However, tools and approaches are available to evaluate contaminant effects on Bay–Delta species, and separate the effects of multiple stressors. Integrated

  17. Holocene Flexural Deformation over the Nile Delta: Evidence from Radar Interferometry

    Science.gov (United States)

    Gebremichael, E.; Sultan, M.; Becker, R.

    2017-12-01

    Isostatic adjustment and subsequent subsidence and uplift due to sediment and water loading and unloading mechanisms is one of the major factors that produce regional deformational patterns across river deltas. Using 84 Envisat ASAR scenes that were acquired (2004 - 2010) along three tracks and applying Persistent scatterer (PS) radar interferometric techniques, we documented flexural deformational patterns over the entire Nile Delta (length: 186 km; width: 240 km) of Egypt. The passive continental margin of Africa subsided from Jurassic time onwards due to isostatic loading creating an accommodation space and consequently, the deposition of relatively younger sediments on the oceanic crust. In river deltas, the flexural isostasy model dictates that a subsidence in the oceanic crust side should be balanced by a bulge (uplift) in the flanking regions. Using radar interferometry, we were able to identify the flexural deformation pattern and map its spatial extent over the northern and central Nile Delta region. Findings include: (1) the northern Nile Delta region (block) is separated from the southern delta region by an east-west trending, extensively faulted, hinge line that signifies the boundary between two deformational patterns (subsidence and uplift). It separates the highly subsiding (up to 9.8 mm/yr) northern delta block (up to 85 km long) from the nearly stable (0.4 mm/yr; averaged) southern delta block (up to 91 km long). The hinge line marks the end of the passive continental margin of Africa and the beginning of the oceanic crust of the Mediterranean. (2) We mapped the extent of a 20-40 km wide flexural uplift zone to the south of the hinge line. Within the flexural uplift zone (2.5 mm/yr; averaged), there is a gradual increase in uplift rate reaching peak value (up to 7 mm/yr) near the midpoint of the zone. (3) The uplift rate gradually decreases south of the flexure boundary reaching 0.3 mm/yr at the southern periphery of the delta. (4) The flexural

  18. Experimental Investigations on Leading-Edge Vortex Structures for Flow over Non-Slender Delta Wings

    International Nuclear Information System (INIS)

    Jin-Jun, Wang; Wang, Zhang

    2008-01-01

    The dye injection and hydrogen bubble visualization techniques are used to investigate the dual-vortex structure including its development, breakdown and the spatial location of vortex core over nonslender delta wings. It is concluded that the dual-vortex structure can be affected significantly by sweep angle and Reynolds number, and generated only at small angle of attack. The angle between the projection of outer vortex core on delta wing surface and the root chord line has nothing to do with the Reynolds Number and angle of attack, but has simple linear relation with the sweep angle of the model tested. (fundamental areas of phenomenology (including applications))

  19. Morphodynamics of a cyclic prograding delta: the Red River, Vietnam

    NARCIS (Netherlands)

    Maren, D.S. van

    2004-01-01

    River deltas are inhabited by over 60% of the world population, and are, consequently, of paramount agricultural and economical importance. They constitute unique wetland envi ronments which gives river deltas ecological importance as well. Additionally, many deltas contain large accumulations of

  20. Environmental challenges in Nigeria's Delta Region and Agriculture ...

    African Journals Online (AJOL)

    The paper discussed the environmental challenges in the Niger-Delta region of Nigeria with emphasis on the impacts on agricultural production. It thus discussed the concepts of Niger-Delta, Environmental pollution, Niger-Delta crises and Agriculture. The paper posits that there are positive relationships between these ...

  1. River delta shoreline reworking and erosion in the Mediterranean and Black Seas: the potential roles of fluvial sediment starvation and other factors

    Directory of Open Access Journals (Sweden)

    Manon Besset

    2017-09-01

    Full Text Available The Mediterranean basin (including the Black Sea is characterized by a plethora of deltas that have developed in a wave-influenced setting. Many of these deltas are sourced in sediments by river catchments that have been variably dammed. The vulnerability status of a selection of ten deltas subject to different levels of reduction in fluvial sediment supply following damming was analysed by quantifying changes in delta protrusion area and protrusion angle over the last 30 years. The rationale for choosing these two metrics, which do not require tricky calculations of longshore bedload transport volumes and river ‘influence’, is that as sediment supply wanes, increasing relative efficiency of waves leads to longshore redistribution of reworked sediments and progressive ‘flattening’ of the delta protrusion. The results show that eight of the ten deltas (Nile, Rhône, Ebro, Ceyhan, Arno, Ombrone, Moulouya, Medjerda are in erosion, whereas two (Danube, Po show stability, but the statistical relationship between change in delta protrusion area and sediment flux reduction is poor, thus suggesting that the role of dams in causing delta shoreline erosion may have been over-estimated. But this poor relationship could also be due to a long temporal lag between dam construction and bedload removal and transport to the coast downstream of dams, and, where the delta protrusion is being eroded, to bedload trapping by shoreline engineering structures and by elongating delta-flank spits. Other potential influential factors in shoreline change include subsidence, sea-level rise, storminess, exceptional river floods, and managed sediment releases downstream of dams. A longer observation period and high-resolution sediment-budget studies will be necessary to determine more definitively to which extent continued trapping of sediment behind dams will impact overall delta stability in the Mediterranean and Black Seas. Mitigation of delta erosion is likely to

  2. Regional controls on geomorphology, hydrology, and ecosystem integrity in the Orinoco Delta, Venezuela

    Science.gov (United States)

    Warne, A.G.; Meade, R.H.; White, W.A.; Guevara, E.H.; Gibeaut, J.; Smyth, R.C.; Aslan, A.; Tremblay, T.

    2002-01-01

    Interacting river discharge, tidal oscillation, and tropical rainfall across the 22,000 km2 Orinoco delta plain support diverse fresh and brackish water ecosystems. To develop environmental baseline information for this largely unpopulated region, we evaluate major coastal plain, shallow marine, and river systems of northeastern South America, which serves to identify principal sources and controls of water and sediment flow into, through, and out of the Orinoco Delta. The regional analysis includes a summary of the geology, hydrodynamics, sediment dynamics, and geomorphic characteristics of the Orinoco drainage basin, river, and delta system. Because the Amazon River is a major source of sediment deposited along the Orinoco coast, we summarize Amazon water and sediment input to the northeastern South American littoral zone. We investigate sediment dynamics and geomorphology of the Guiana coast, where marine processes and Holocene history are similar to the Orinoco coast. Major factors controlling Orinoco Delta water and sediment dynamics include the pronounced annual flood discharge; the uneven distribution of water and sediment discharge across the delta plain; discharge of large volumes of water with low sediment concentrations through the Rio Grande and Araguao distributaries; water and sediment dynamics associated with the Guayana littoral current along the northeastern South American coast; inflow of large volumes of Amazon sediment to the Orinoco coast; development of a fresh water plume seaward of Boca Grande; disruption of the Guayana Current by Trinidad, Boca de Serpientes, and Gulf of Paria; and the constriction at Boca de Serpientes. ?? 2002 Elsevier Science B.V. All rights reserved.

  3. deltaPlotR: An R Package for Di?erential Item Functioning Analysis with Ango? s Delta Plot

    OpenAIRE

    David Magis; Bruno Facon

    2014-01-01

    Angoff's delta plot is a straightforward and not computationally intensive method to identify differential item functioning (DIF) among dichotomously scored items. This approach was recently improved by proposing an optimal threshold selection and by considering several item purification processes. Moreover, to support practical DIF analyses with the delta plot and these improvements, the R package deltaPlotR was also developed. The purpose of this paper is twofold: to outline the delta plot ...

  4. Impacts of Declining Mississippi River Sediment Load on Subaqueous Delta Front Sedimentation and Geomorphology

    Science.gov (United States)

    Maloney, J. M.; Bentley, S. J.; Xu, K.; Georgiou, I. Y.; Miner, M. D.

    2016-02-01

    The Mississippi River delta system is undergoing unprecedented changes due to the effects of climate change and anthropogenic alterations to the river and its delta. Since the 1950s, the suspended sediment load of the Mississippi River has decreased by approximately 50% due to the construction of >50,000 dams in the Mississippi basin. The impact of this decreased sediment load has been observed in subaerial environments, but the impact on sedimentation and geomorphology of the subaqueous delta front has yet to be examined. To identify historic trends in sedimentation patterns, we compiled bathymetric datasets, including historical charts, industry and academic surveys, and NOAA data, collected between 1764 and 2009. Sedimentation rates are variable across the delta front, but are highest near the mouth of Southwest Pass, which carries the largest percentage of Mississippi River flow and sediment into the Gulf of Mexico. The progradation rate of Southwest Pass (measured at the 10 m depth contour) has slowed from 67 m/yr between 1764 and 1940 to 26 m/yr between 1940 and 1979, with evidence of further deceleration from 1979-2009. Decreased rates of progradation are also observed at South Pass and Pass A Loutre, with the 10 m contour retreating at rates >20 m/yr at both passes. Advancement of the delta front also decelerated in deeper water (15-90 m) offshore from Southwest Pass. In this area, from 1940-1979, depth contours advanced seaward 30 m/yr, but rates declined from 1979-2005. Furthermore, over the same area, the sediment accumulation rate decreased by 81% for the same period. The Mississippi River delta front appears to be entering a phase of decline, which will likely be accelerated by future upstream management practices. This decline has implications for offshore ecosystems, biogeochemical cycling, pollutant dispersal, mudflow hazard, and the continued use of the delta as an economic and population center.

  5. Vulnerability and Resilience of the Niger Delta Coastal Communities to Pollution and Environmental Degradation

    Science.gov (United States)

    Ndimele, P. E.; Whenu, O. O.; Anwan, H. R.; Anetekhai, M. A.

    2016-02-01

    The Niger Delta is Africa's largest delta consisting of the third largest mangrove forest in the world and covering 70,000km2 of Nigeria land mass. This delta is the largest wetland in Africa and among the ten most important wetland and marine ecosystems in the world. The delta is home to all of Nigeria's endemic or near-endemic mammal species and to six IUCN Red List mammals. The Niger Delta harbours globally outstanding fish fauna and displays exceptional evolutionary phenomena with its higher taxonomic endemism and distinct species assemblages. The Niger delta is blessed with abundance of natural and human resources, including the majority of Nigeria's oil and gas deposits, good agricultural land, extensive forests, excellent fisheries as well as a well-developed industrial base, a large labour force and a vibrant private sector. However, this fragile but rich ecosystem is seriously threatened by increased industrial pollution, resource over-exploitation and environmental degradation caused by over six decades of oil exploitation. Aquatic life has been destroyed with the pollution of traditional fishing grounds, exacerbating hunger and poverty in fishing communities. The multifarious use of the delta has led to human-induced changes in biota, habitats and landscapes necessitating the development of a holistic policy that considers all the interacting factors in the ecosystem. Taking a systems approach incorporating an understanding of The Ecosystem Approach, vulnerability, resilience, the DPSIR framework, ecosystem services and societal benefits are integrated in order to evolve a management tool that will result in sustainable resource exploitation, improvement in living standards of locals and restoration of the ecosystem.

  6. What fish and how many there are in Danube Delta?

    Directory of Open Access Journals (Sweden)

    NĂVODARU Ion

    2011-09-01

    Full Text Available The real figure of fish fauna and fishery of the Danube delta is difficult to be estimated due to the limitation in fish sampling and underreporting of catch. This paper proposes to compare output of fish sampling with commercial catch statistics. Fish fauna from Danube delta complex lakes was sampled in 2006-2008 period and catchstatistics represent a long time series data recording. For fish sampling was used two complementary methods: electric fishing for shallow border zone and Nordic gillnet fishing for deep open water. The frequency of occurrence and the dominance in abundance analysis was based on 267 samples including 57158 individuals from both sampling methods since the dominance in biomass was based on 640 kg of fish only from gillnet sampling. In total was sampled 40 fish species, while catch statistics recorded 10 commercial species plus more 3 categories that include more other different species. In the sampling analysis, the most frequent species (very frequent were perch, bleak, roach, rudd and white bream. The most abundant(eudominant and dominant species were bleak, roach, rudd, perch, and white bream. In biomass dominate (eudominant and dominant roach, rudd, perch, white bream, bleak, gibel carp and pike. This analysis shows that Danube delta lakes are dominate by small eurytopic and opportunistic species, favoured by eutrophication of lakes. However, this figure is expression of sampling methods that are limited in estimation of real fish population status. Nevertheless, when this structure is compared to commercial statistics, it is noticed completely other figure. The difference in fish structure may be explained by targeting fishing to large size and high market value fish species. It is not neglected that commercial statistics is deformed by unreported catch sold on black market. According with recorded statistics from 1920 until 2010 the catch trend continuously decrease and species composition was well balanced before

  7. Triangulation, Emotional Reactivity, and Violence in the Niger Delta

    Directory of Open Access Journals (Sweden)

    Benjamin Aigbe Okonofua

    2013-04-01

    Full Text Available The Niger Delta conflict, for many years, was blamed on myriad forces, including greed, economic exploitation, pollution and ecological damage, resource appropriation and distribution disputes, ethno-religious antagonisms, poverty, unemployment, large-scale infrastructural deficits, corruption, militarization of oil producing communities and election processes, sociopolitical marginalization, cultism, and weapons proliferation. While all of these issues are important, they are not nearly as important as the deliberate roles played by high-level social, economic, and political interests who activated violence as a means to secure economic advantage from the delta’s oil industry. This study shines the light on this small, exclusive, and very powerful group whose actions triggered off the violence and yet are at the center of efforts to institute peace including the current disarmament, demobilization, and reintegration (DDR program. I argue that unless the contributions of these powerful interests are carefully teased out and the structures they have built to advantage themselves from the conflict are dismantled, peace will remain elusive in the Niger Delta.

  8. WC1+ gamma delta T cells from cattle naturally infected with Mycobacterium avium subsp. paratuberculosis respond differentially to stimulation with PPD-J.

    Science.gov (United States)

    A role for gamma delta T cells in protection against mycobacterial infections including Johne’s disease (JD) has been suggested. In neonatal calves where the risk to infection with Mycobacterium avium subsp. paratuberculosis (MAP) is high, the majority of circulating CD3+ lymphocytes are gamma delta...

  9. Role of delta excitations in pion-, photon- and nucleon-nucleus reactions studied with microscopic models

    International Nuclear Information System (INIS)

    Engel, A.

    1995-01-01

    Delta excitation plays a prominent role in intermediate heavy reactions. In this paper, comment is made on the calculations done for pion-, photon- and nucleon-nucleus reactions using the Boltzmann-Uehling-Uhlenbeck (BUU) model and the antisymmetrized molecular dynamics (AMD) model. First, it is recalled how to include delta degrees in microscopic models in general. Then, the comparison of the microscopic calculation performed by the author with the experimental data is presented. Deltas in microscopic models are discussed. Pion-nucleus reactions have been studied since pion beams became available, especially for exploring the delta resonance in a nuclear medium. The dependence of pion absorption cross section on incident pion energy is shown. The photon-induced pion production in the resonance energy region was studied with the BUU model. The calculated results of neutral pion photo-production are shown. In both inelastic proton scattering and (p,n) charge exchange reaction, the excitation of delta resonance can be observed clearly in the experimental data. The results of the AMD calculation for 12 C(p,p') reaction are shown. (K.I.)

  10. Conceptual model of sedimentation in the Sacramento-San Joaquin River Delta

    Science.gov (United States)

    Schoellhamer, David H.; Wright, Scott A.; Drexler, Judith Z.

    2012-01-01

    Sedimentation in the Sacramento–San Joaquin River Delta builds the Delta landscape, creates benthic and pelagic habitat, and transports sediment-associated contaminants. Here we present a conceptual model of sedimentation that includes submodels for river supply from the watershed to the Delta, regional transport within the Delta and seaward exchange, and local sedimentation in open water and marsh habitats. The model demonstrates feedback loops that affect the Delta ecosystem. Submerged and emergent marsh vegetation act as ecosystem engineers that can create a positive feedback loop by decreasing suspended sediment, increasing water column light, which in turn enables more vegetation. Sea-level rise in open water is partially countered by a negative feedback loop that increases deposition if there is a net decrease in hydrodynamic energy. Manipulation of regional sediment transport is probably the most feasible method to control suspended sediment and thus turbidity. The conceptual model is used to identify information gaps that need to be filled to develop an accurate sediment transport model.

  11. An updated conceptual model of Delta Smelt biology: Our evolving understanding of an estuarine fish

    Science.gov (United States)

    Baxter, Randy; Brown, Larry R.; Castillo, Gonzalo; Conrad, Louise; Culberson, Steven D.; Dekar, Matthew P.; Dekar, Melissa; Feyrer, Frederick; Hunt, Thaddeus; Jones, Kristopher; Kirsch, Joseph; Mueller-Solger, Anke; Nobriga, Matthew; Slater, Steven B.; Sommer, Ted; Souza, Kelly; Erickson, Gregg; Fong, Stephanie; Gehrts, Karen; Grimaldo, Lenny; Herbold, Bruce

    2015-01-01

    The main purpose of this report is to provide an up-to-date assessment and conceptual model of factors affecting Delta Smelt (Hypomesus transpacificus) throughout its primarily annual life cycle and to demonstrate how this conceptual model can be used for scientific and management purposes. The Delta Smelt is a small estuarine fish that only occurs in the San Francisco Estuary. Once abundant, it is now rare and has been protected under the federal and California Endangered Species Acts since 1993. The Delta Smelt listing was related to a step decline in the early 1980s; however, population abundance decreased even further with the onset of the “pelagic organism decline” (POD) around 2002. A substantial, albeit short-lived, increase in abundance of all life stages in 2011 showed that the Delta Smelt population can still rebound when conditions are favorable for spawning, growth, and survival. In this report, we update previous conceptual models for Delta Smelt to reflect new data and information since the release of the last synthesis report about the POD by the Interagency Ecological Program for the San Francisco Estuary (IEP) in 2010. Specific objectives include:

  12. Detritus fuels ecosystem metabolism but not metazoan food webs in San Francisco estuary's freshwater delta

    Science.gov (United States)

    Sobczak, W.V.; Cloern, J.E.; Jassby, A.D.; Cole, B.E.; Schraga, T.S.; Arnsberg, A.

    2005-01-01

    Detritus from terrestrial ecosystems is the major source of organic matter in many streams, rivers, and estuaries, yet the role of detritus in supporting pelagic food webs is debated. We examined the importance of detritus to secondary productivity in the Sacramento and San Joaquin River Delta (California, United States), a large complex of tidal freshwater habitats. The Delta ecosystem has low primary productivity but large detrital inputs, so we hypothesized that detritus is the primary energy source fueling production in pelagic food webs. We assessed the sources, quantity, composition, and bioavailability of organic matter among a diversity of habitats (e.g., marsh sloughs, floodplains, tidal lakes, and deep river channels) over two years to test this hypothesis. Our results support the emerging principle that detritus dominates riverine and estuarine organic matter supply and supports the majority of ecosystem metabolism. Yet in contrast to prevailing ideas, we found that detritus was weakly coupled to the Delta's pelagic food web. Results from independent approaches showed that phytoplankton production was the dominant source of organic matter for the Delta's pelagic food web, even though primary production accounts for a small fraction of the Delta's organic matter supply. If these results are general, they suggest that the value of organic matter to higher trophic levels, including species targeted by programs of ecosystem restoration, is a function of phytoplankton production. ?? 2005 Estuarine Research Federation.

  13. Delta-nucleus dynamics: proceedings of symposium

    International Nuclear Information System (INIS)

    Lee, T.S.H.; Geesaman, D.F.; Schiffer, J.P.

    1983-10-01

    The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta Δ(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe Δ-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented

  14. Hyperon-meson and delta-meson coupling to protoneutron stars structure using the nonlinear Walecka model

    International Nuclear Information System (INIS)

    Souto, W A; Oliveira, J C T; Rodrigues, H; Duarte, S B; Chiapparini, M

    2015-01-01

    In this work we determine the equation of state and the population of baryons and leptons and discuss the effects of the hyperon-meson coupling constants to the formation of delta resonances in the stellar medium. We also discuss the structure of the protoneutron stars including the delta matter in their composition, and compared the results of a cooled neutron star, after escape of neutrinos. For protoneutron stars structure and composition, the neutrinos are considered trapped. (paper)

  15. Inhibition of cortiocosteroidogenesis by delta-9-tetrahydrocannabinol.

    Science.gov (United States)

    Warner, W; Harris, L S; Carchman, R A

    1977-12-01

    ACTH, cholera toxin, cyclic AMP but not pregnenolone-induced steroidogenesis in Y-1 functional mouse adrenal tumor cells was significantly inhibited by delta-9-tetrahydrocannabinol, cannabidiol, and cannabinol. The inhibition of steroidogenesis could not be correlated with a general depression in cell function or viability. The data suggest that cannabinoids inhibit corticosteroidogenesis at a site between the synthesis of cAMP and of pregnenolone.

  16. Determination of the positions and residues of the. delta. /sup + +/ and. delta. /sup 0/ poles. [Phase shifts,coulomb corrections

    Energy Technology Data Exchange (ETDEWEB)

    Vasan, S S [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

    1976-04-19

    The poles and the associated residues in the ..pi..N P/sub 33/ amplitude corresponding to the resonances ..delta../sup + +/ and ..delta../sup 0/ are determined by fitting the ..pi../sup +/p and ..pi../sup -/p hadronic phase shifts from the Carter 73 analysis. The ..delta../sup + +/ and ..delta../sup 0/ pole positions are determined also from the nuclear phase shifts, these being the phase shifts made up of the hadronic phase shifts plus the Coulomb corrections. The pole positions obtained from the two sets of phase shifts are different, the differences being larger in the case of the ..delta../sup + +/.

  17. Pulsations of delta Scuti stars

    International Nuclear Information System (INIS)

    Cox, A.N.

    1989-01-01

    A general review of the pulsating δ Scuti variables is given including the observed light curves and positions of the stars in the Hertzsprung-Russell diagram. Theoretical interpretations from evolution and pulsation calculations give their masses, radii, luminosities, and even their approximate internal compositions. Three models of these stars are discussed and used to study the nonlinear hydrodynamic behavior of these stars. The hydrodynamic equations and the Stellingwerf method for obtaining strictly periodic solutions are outlined. Problems of allowing for time-dependent convection and its great sensitivity to temperature and density are presented. Tentative results to date do not show any tendency for amplitudes to grow to large unobserved amplitudes, in disagreement with an earlier suggestion by Stellingwerf. It is found that the very small growth rates of the pulsations may even be too small to be useful in seeking a periodic solution. 15 refs., 8 figs., 3 tabs

  18. Adaptive Delta Management: cultural aspects of dealing with uncertainty

    Science.gov (United States)

    Timmermans, Jos; Haasnoot, Marjolijn; Hermans, Leon; Kwakkel, Jan

    2016-04-01

    Deltas are generally recognized as vulnerable to climate change and therefore a salient topic in adaptation science. Deltas are also highly dynamic systems viewed from physical (erosion, sedimentation, subsidence), social (demographic), economic (trade), infrastructures (transport, energy, metropolization) and cultural (multi-ethnic) perspectives. This multi-faceted dynamic character of delta areas warrants the emergence of a branch of applied adaptation science, Adaptive Delta Management, which explicitly focuses on climate adaptation of such highly dynamic and deeply uncertain systems. The application of Adaptive Delta Management in the Dutch Delta Program and its active international dissemination by Dutch professionals results in the rapid dissemination of Adaptive Delta Management to deltas worldwide. This global dissemination raises concerns among professionals in delta management on its applicability in deltas with cultural conditions and historical developments quite different from those found in the Netherlands and the United Kingdom where the practices now labelled as Adaptive Delta Management first emerged. This research develops an approach and gives a first analysis of the interaction between the characteristics of different approaches in Adaptive Delta Management and their alignment with the cultural conditions encountered in various delta's globally. In this analysis, first different management theories underlying approaches to Adaptive Delta Management as encountered in both scientific and professional publications are identified and characterized on three dimensions: The characteristics dimensions used are: orientation on today, orientation on the future, and decision making (Timmermans, 2015). The different underlying management theories encountered are policy analysis, strategic management, transition management, and adaptive management. These four management theories underlying different approaches in Adaptive Delta Management are connected to

  19. Delta count-rate monitoring system

    International Nuclear Information System (INIS)

    Van Etten, D.; Olsen, W.A.

    1985-01-01

    A need for a more effective way to rapidly search for gamma-ray contamination over large areas led to the design and construction of a very sensitive gamma detection system. The delta count-rate monitoring system was installed in a four-wheel-drive van instrumented for environmental surveillance and accident response. The system consists of four main sections: (1) two scintillation detectors, (2) high-voltage power supply amplifier and single-channel analyzer, (3) delta count-rate monitor, and (4) count-rate meter and recorder. The van's 6.5-kW generator powers the standard nuclear instrument modular design system. The two detectors are mounted in the rear corners of the van and can be run singly or jointly. A solid-state bar-graph count-rate meter mounted on the dashboard can be read easily by both the driver and passenger. A solid-state strip chart recorder shows trends and provides a permanent record of the data. An audible alarm is sounded at the delta monitor and at the dashboard count-rate meter if a detected radiation level exceeds the set background level by a predetermined amount

  20. Aerodynamic Interaction between Delta Wing and Hemisphere-Cylinder in Supersonic Flow

    Science.gov (United States)

    Nishino, Atsuhiro; Ishikawa, Takahumi; Nakamura, Yoshiaki

    As future space vehicles, Reusable Launch Vehicle (RLV) needs to be developed, where there are two kinds of RLV: Single Stage To Orbit (SSTO) and Two Stage To Orbit (TSTO). In the latter case, the shock/shock interaction and shock/boundary layer interaction play a key role. In the present study, we focus on the supersonic flow field with aerodynamic interaction between a delta wing and a hemisphere-cylinder, which imitate a TSTO, where the clearance, h, between the delta wing and hemisphere-cylinder is a key parameter. As a result, complicated flow patterns were made clear, including separation bubbles.

  1. Effects of delta degrees of freedom on quark condensate in hot and dense matter

    International Nuclear Information System (INIS)

    Li Lei; Ning Pingzhi

    1996-01-01

    The relativistic mean-field theory is applied to study the quark condensate systematically in nuclear matter at zero and finite temperature in terms of the relative importance of delta degrees of freedom. Calculations have included the high-order contributions to quark condensate in nuclear medium due to the baryon-baryon interactions. Numerical results are presented for the nuclear density up to five times larger than the normal density and temperature up to 120 MeV. It is found that the delta resonance in nuclear matter can cause substantial decreases to in-medium quark condensate

  2. Nitrogen Leaching in Intensive Cropping Systems in Tam Duong District, Red River Delta of Vietnam

    OpenAIRE

    Trinh, M.V.; Keulen, van, H.; Roetter, R.P.

    2010-01-01

    The environmental and economic consequences of nitrogen (N) lost in rice-based systems in Vietnam is important but has not been extensively studied. The objective of this study was to quantify the amount of N lost in major cropping systems in the Red River Delta. An experiment was conducted in the Red River Delta of Vietnam, on five different crops including rose, daisy, cabbage, chili, and a rice–rice–maize rotation during 2004 and 2005. Core soil samples were taken periodically in 20-cm inc...

  3. Trends and driving mechanism of land-use change in metropolitan areas of Pearl River Delta

    Science.gov (United States)

    Chen, Feng-gui; Zhang, Hong-ou; Wang, Juan; Wu, Qi-tao

    2008-10-01

    Taking Pearl River Delta for an example this study focuses on the trends and the driving mechanism of land-use changes in metropolises, in order to achieve the fundamental objectives of LUCC study increasing the awareness on dynamics of global land-use and land-cover changes, and improving the ability of forecasting LUCC. By analyzing the land-use change in Pearl River Delta from 1996 to 2006, it is found that the differences among internal space are notable. By establishing time-sequence-curve with SPSS software, it is shown that trends of land-use change are very clear. With factor analysis on land-use change, the study summarizes four factors of driving mechanism, including factors of economic development level, regional industrial structure, demographic and agricultural structure adjustment, which impact land change in Pearl River Delta to a different extent.

  4. Exosat/Delta - Demonstrated short-term backup launcher capability through international cooperation

    Science.gov (United States)

    Ganoung, J. K.; Altmann, G.; Eaton, P.; Kraft, J. D.

    1983-01-01

    The instrumentation, performance parameters, Delta launch implementation, and development program of the Exosat, launched in February 1983 are described. The X ray satellite was integrated into the Delta vehicle over a three month period, and will survey mainly previously observed X ray objects by directing its detectors at them just before they are occulted by the moon. The 120 kg science package, powered by 260 W of power from solar panels, include low- and medium-energy imaging devices. The spacecraft was originally intended for Ariane launch, but scheduling conflicts, plus the need for a polar-type orbit, dictated the use of the Western Space and Missile Center. Maintenance of Delta compatibility throughout the development of the Exosat facilitated the transfer of launch vehicles, as did full existing documentation of the spacecraft and familiarity between the ESA and NASA managers of the development and launch programs, respectively.

  5. Three dimensional [delta]f simulations of beams in the SSC

    Energy Technology Data Exchange (ETDEWEB)

    Koga, J.; Tajima, T. (Texas Univ., Austin, TX (United States). Inst. for Fusion Studies); Machida, S. (Superconducting Super Collider Lab., Dallas, TX (United States))

    1993-02-01

    A three dimensional [delta]f strong-strong algorithm has been developed to apply to the study of such effects as space charge and beam-beam interaction phenomena in the Superconducting Super Collider (SSC). The algorithm is obtained from the merging of the particle tracking code Simpsons used for 3-dimensional space charge effects and a [delta]f code. The [delta]f method is used to follow the evolution of the non-gaussian part of the beam distribution. The advantages of this method are twofold. First, the Simpsons code utilizes a realistic accelerator model including synchrotron oscillations and energy ramping in 6-dimensional phase space with electromagnetic fields of the beams calculated using a realistic 3-dimensional field solver. Second, the beams are evolving in the fully self-consistent strong-strong sense where finite particle fluctuation noise is greatly reduced as opposed to the weak-strong models where one beam is fixed.

  6. Three dimensional {delta}f simulations of beams in the SSC

    Energy Technology Data Exchange (ETDEWEB)

    Koga, J.; Tajima, T. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies; Machida, S. [Superconducting Super Collider Lab., Dallas, TX (United States)

    1993-02-01

    A three dimensional {delta}f strong-strong algorithm has been developed to apply to the study of such effects as space charge and beam-beam interaction phenomena in the Superconducting Super Collider (SSC). The algorithm is obtained from the merging of the particle tracking code Simpsons used for 3-dimensional space charge effects and a {delta}f code. The {delta}f method is used to follow the evolution of the non-gaussian part of the beam distribution. The advantages of this method are twofold. First, the Simpsons code utilizes a realistic accelerator model including synchrotron oscillations and energy ramping in 6-dimensional phase space with electromagnetic fields of the beams calculated using a realistic 3-dimensional field solver. Second, the beams are evolving in the fully self-consistent strong-strong sense where finite particle fluctuation noise is greatly reduced as opposed to the weak-strong models where one beam is fixed.

  7. Three dimensional [delta][ital f] simulations of beams in the SSC

    Energy Technology Data Exchange (ETDEWEB)

    Koga, J.; Tajima, T. (Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712-1060 (United States)); Machida, S. (SSC Laboratory, 2550 Beckleymeade Avenue, Dallas, Texas 75237 (United States))

    1993-12-25

    A three dimensional [delta][ital f] strong-strong algorithm has been developed to apply to the study of such effects as space charge and beam-beam interaction phenomena in the Superconducting Super Collider (SSC). The algorithm is obtained from the merging of the particle tracking code Simpsons used for 3 dimensional space charge effects and a [delta][ital f] code. The [delta][ital f] method is used to follow the evolution of the non-gaussian part of the beam distribution. The advantages of this method are twofold. First, the Simpsons code utilizes a realistic accelerator model including synchrotron oscillations and energy ramping in 6 dimensional phase space with electromagnetic fields of the beams calculated using a realistic 3 dimensional field solver. Second, the beams are evolving in the fully self-consistent strong-strong sense with finite particle fluctuation noise is greatly reduced as opposed to the weak-strong models where one beam is fixed.

  8. Changes in Ecosystem Services and related Livelihoods in the Mekong Delta: vulnerabilities and adaptation strategies

    Science.gov (United States)

    Sebesvari, Z.; Renaud, F. G.

    2014-12-01

    The Mekong Delta (Vietnam) is highly vulnerable to the many impacts of global environmental change as well as to the accelerating anthropogenic changes in the catchment and in the delta itself. Today the delta is an agricultural landscape controlled by engineering structures such as channels, dykes, embankments, and sluice gates. These structures have been constructed gradually over the last 200 years mainly for irrigation and flood control in the upper part of the delta and to control saline intrusion in the coastal areas. Recent changes in the hydrology mainly driven by upstream hydropower development on the mainstream and the tributaries of the Mekong will likely have far reaching impacts on the delta´s social-ecological systems through changes in e.g. sedimentation processes, nutrient transport as well as the health of aquatic ecosystems. Further threats to the delta include sea level rise and an increase in seasonal rainfall variability leading to an increase in flood variability. These changes affect the lives of millions of low-income inhabitants who depend on the ecosystem services provided by the Mekong for their livelihoods and sustenance. Since the changes in ecosystem service provision are occurring relatively fast while the resource dependency of the delta population is very high, adaptation becomes a challenge. An assessment of livelihood dependencies on ecosystem services requires an understanding of ecosystem services affected by different drivers of change, as well as of the types of livelihoods likely to be jeopardized as a result of these changes. We will present main ecosystem services supporting specific livelihoods, discuss how they are threatened, and analyse the merits of potential solutions. Options based solely on grey infrastructure might be problematic on the long term while an integration of ecosystem based solution such as a (re)adaptation of agricultural production systems to floods in the upper delta might be a more sustainable

  9. Pulsations of delta Scuti stars

    International Nuclear Information System (INIS)

    Cox, A.N.

    1990-01-01

    In this paper the authors give a general review of the pulsating δ Scuti variables, including the observed light curves and positions of the stars in the Hertzsprung-Russell diagram. Theoretical interpretations from evolution and pulsation calculations give their masses, radii, luminosities, and even their approximate internal compositions. Then we discuss three models of these stars, and use them to study the nonlinear hydrodynamic behavior of these stars, after which the authors outline the hydrodynamic equations and the Stellingwerf method for obtaining strictly periodic solutions. The authors also present the problems of allowing for time-dependent convection and its great sensitivity to temperature and density. Tentative results to data do not show any tendency for amplitudes to grow to large unobserved amplitudes, in disagreement with an earlier suggestion by Stellingwerf. Finally, the authors find that the very small growth rates of the pulsations may even be too small to be useful in seeking a periodic solution. The δ Scuti variables are the most common type of variable star in our galaxy except for the white dwarfs. This is because stars in the mass range from just over one M circle-dot up to at least several M circle-dot pass through the yellow giant instability strip in the Hertzsprung-Russell diagram as they evolve off the main sequence to the red. Actually, stars up to the maximum main sequence mass also evolve through this region at higher luminosities, but there are so few of them, and they evolve so rapidly to the red, that they are almost unknown. At the higher luminosity, they probably would be called first-instability strip-crossing Cepheids anyway. Such cepheids are difficult to separate from those that are on the second blueward instability strip crossing that is much slower. Really, the δ Scuti variables are just low-luminosity Cepheids

  10. New seismograph includes filters

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-02

    The new Nimbus ES-1210 multichannel signal enhancement seismograph from EG and G geometrics has recently been redesigned to include multimode signal fillers on each amplifier. The ES-1210F is a shallow exploration seismograph for near subsurface exploration such as in depth-to-bedrock, geological hazard location, mineral exploration, and landslide investigations.

  11. Formation of conjugated delta8,delta10-double bonds by delta12-oleic-acid desaturase-related enzymes: biosynthetic origin of calendic acid.

    Science.gov (United States)

    Cahoon, E B; Ripp, K G; Hall, S E; Kinney, A J

    2001-01-26

    Divergent forms of the plant Delta(12)-oleic-acid desaturase (FAD2) have previously been shown to catalyze the formation of acetylenic bonds, epoxy groups, and conjugated Delta(11),Delta(13)-double bonds by modification of an existing Delta(12)-double bond in C(18) fatty acids. Here, we report a class of FAD2-related enzymes that modifies a Delta(9)-double bond to produce the conjugated trans-Delta(8),trans-Delta(10)-double bonds found in calendic acid (18:3Delta(8trans,10trans,12cis)), the major component of the seed oil of Calendula officinalis. Using an expressed sequence tag approach, cDNAs for two closely related FAD2-like enzymes, designated CoFADX-1 and CoFADX-2, were identified from a C. officinalis developing seed cDNA library. The deduced amino acid sequences of these polypeptides share 40-50% identity with those of other FAD2 and FAD2-related enzymes. Expression of either CoFADX-1 or CoFADX-2 in somatic soybean embryos resulted in the production of calendic acid. In embryos expressing CoFADX-2, calendic acid accumulated to as high as 22% (w/w) of the total fatty acids. In addition, expression of CoFADX-1 and CoFADX-2 in Saccharomyces cerevisiae was accompanied by calendic acid accumulation when induced cells were supplied exogenous linoleic acid (18:2Delta(9cis,12cis)). These results are thus consistent with a route of calendic acid synthesis involving modification of the Delta(9)-double bond of linoleic acid. Regiospecificity for Delta(9)-double bonds is unprecedented among FAD2-related enzymes and further expands the functional diversity found in this family of enzymes.

  12. Hydroclimatic mechanisms of cholera transmission in the Bengal Delta

    Science.gov (United States)

    Tretkoff, Ernie

    2011-07-01

    Cholera, a deadly waterborne disease, remains a major threat in many areas of the world, including the Bengal Delta region. In this region, cholera outbreaks have two annual peaks; the first occurs during the dry season in the spring, and the second occurs in the fall following the wet season. However, the large-scale hydroclimatic processes underlying the propagation of the disease have not been well understood. Akanda et al. show that cholera outbreaks in the Bengal Delta region propagate from the coast to inland and from spring to fall following two distinct transmission cycles. The first outbreak begins in the spring near the coast when northward movement of plankton-rich seawater and increasing salinity promote the growth of cholera-causing bacteria in rivers, which are used for irrigation, sanitation, and consumption. The second outbreak begins in the fall, after summer floods and monsoons affect sanitation conditions that aid in bacterial transmission by contaminating waters over much of Bangladesh. (Water Resources Research, doi:10.1029/ 2010WR009914, 2011)

  13. Biomass co-firing for Delta Electricity

    International Nuclear Information System (INIS)

    Anon

    2014-01-01

    Electricity generator Delta Electricity has implemented a biomass co-firing program at its Vales Point power station on the Central Coast to reduce its reliance on coal and emissions of CO 2 . The program comprises two parts: direct co-firing with coal of up to 5% biomass; and development of Continuous Biomass Converter (CBC) technology with the Crucible Group to remove technology constraints and enable much higher rates of biomass co-firing. It is talking industrial scale tests. Delta increased biomass co-firing in 2013/14 to 32,000 tonnes, up from just 3,000 tonnes the previous year, and conducted biochar co-firing trials at a rate equivalent to 400,000 tonnes per annum to demonstrate the potential of CBC technology. It reduced CO 2 emissions in 2013/14 by more than 32,000 tonnes. 'Legislation and regulations define biomass as renewable,' said Delta Electricity sustainability manager Justin Flood. 'By preferring biomass over coal, the carbon in the coal is not burnt and remains locked up.' One biomass source is wood waste that would normally go to landfill, but the primary driver of Delta's recent increase in co-firing is sawmill residues. 'Previously there was a higher value market for the residues for paper pulp. However, when that market evaporated the timber industry was left with a sizable problem in terms of what to do with its residues and the loss of revenue,' said Flood. The way greenhouse gas accounting is conducted in Australia, with carbon emissions based on site activities, makes it difficult to undertake a life cycle assessment of the program. 'However, some of the international studies looking at this issue have concluded that the net carbon emissions of the biomass system are significantly lower than the coal system because of the uptake of carbon during biomass growth,' said Flood. Delta identified two challenges, sourcing the feedstock and that biomass conversion to electricity is slightly less

  14. Perceived Effects of Community Gardening in Lower Mississippi Delta Gardening Participants

    Science.gov (United States)

    Landry, Alicia S.; Chittendon, Nikki; Coker, Christine E. H.; Weiss, Caitlin

    2015-01-01

    This article describes the perceived physical and psychological health impacts of community gardening on participants in the Mississippi Delta. Themes identified include the use of gardening as an educational tool and as a means to increase self-efficacy and responsibility for personal and community health. Additional benefits of gardening as…

  15. The Development of E-Library at Delta State University Library, Abraka

    African Journals Online (AJOL)

    The study is on the automation of Delta University Library Abraka. The processes involved in the acquisition of information communication technology equipments to complement the traditional Library Services were stated. Major issues discussed include acquisition of computers hardware and library software, telephone ...

  16. Building stones from a muddy delta: Native natural stone from The Netherlands

    NARCIS (Netherlands)

    Nijland, T.G.; Dubelaar, C.W.; Tolboom, H.J.; Hees, R.P.J. van

    2006-01-01

    Most of the Netherlands a Quaternary delta, local supplies of natural stone suitable for building are rare. These include: Quaternary bog iron ores used in early medieval times (until c. 1200); erratics, deposited in boulder clay during the Saalian ice age in the northern Netherlands and gravel from

  17. Soil properties of mangroves in contrasting geomorphic settings within the Zambezi River Delta, Mozambique

    Science.gov (United States)

    Christina E. Stringer; Carl C. Trettin; Stan Zarnoch

    2016-01-01

    Mangroves are well-known for their numerous ecosystem services, including sequestering a significant carbon stock, with soils accounting for the largest pool. The soil carbon pool is dependent on the carbon content and bulk density. Our objective was to assess the spatial variability of mangrove soil physical and chemical properties within the Zambezi River Delta and...

  18. Identifying the Minimum Model Features to Replicate Historic Morphodynamics of a Juvenile Delta

    Science.gov (United States)

    Czapiga, M. J.; Parker, G.

    2017-12-01

    We introduce a quasi-2D morphodynamic delta model that improves on past models that require many simplifying assumptions, e.g. a single channel representative of a channel network, fixed channel width, and spatially uniform deposition. Our model is useful for studying long-term progradation rates of any generic micro-tidal delta system with specification of: characteristic grain size, input water and sediment discharges and basin morphology. In particular, we relax the assumption of a single, implicit channel sweeping across the delta topset in favor of an implicit channel network. This network, coupled with recent research on channel-forming Shields number, quantitative assessments of the lateral depositional length of sand (corresponding loosely to levees) and length between bifurcations create a spatial web of deposition within the receiving basin. The depositional web includes spatial boundaries for areas infilling with sands carried as bed material load, as well as those filling via passive deposition of washload mud. Our main goal is to identify the minimum features necessary to accurately model the morphodynamics of channel number, width, depth, and overall delta progradation rate in a juvenile delta. We use the Wax Lake Delta in Louisiana as a test site due to its rapid growth in the last 40 years. Field data including topset/island bathymetry, channel bathymetry, topset/island width, channel width, number of channels, and radial topset length are compiled from US Army Corps of Engineers data for 1989, 1998, and 2006. Additional data is extracted from a DEM from 2015. These data are used as benchmarks for the hindcast model runs. The morphology of Wax Lake Delta is also strongly affected by a pre-delta substrate that acts as a lower "bedrock" boundary. Therefore, we also include closures for a bedrock-alluvial transition and an excess shear rate-law incision model to estimate bedrock incision. The model's framework is generic, but inclusion of individual

  19. Analytic device including nanostructures

    KAUST Repository

    Di Fabrizio, Enzo M.; Fratalocchi, Andrea; Totero Gongora, Juan Sebastian; Coluccio, Maria Laura; Candeloro, Patrizio; Cuda, Gianni

    2015-01-01

    A device for detecting an analyte in a sample comprising: an array including a plurality of pixels, each pixel including a nanochain comprising: a first nanostructure, a second nanostructure, and a third nanostructure, wherein size of the first nanostructure is larger than that of the second nanostructure, and size of the second nanostructure is larger than that of the third nanostructure, and wherein the first nanostructure, the second nanostructure, and the third nanostructure are positioned on a substrate such that when the nanochain is excited by an energy, an optical field between the second nanostructure and the third nanostructure is stronger than an optical field between the first nanostructure and the second nanostructure, wherein the array is configured to receive a sample; and a detector arranged to collect spectral data from a plurality of pixels of the array.

  20. Saskatchewan resources. [including uranium

    Energy Technology Data Exchange (ETDEWEB)

    1979-09-01

    The production of chemicals and minerals for the chemical industry in Saskatchewan are featured, with some discussion of resource taxation. The commodities mentioned include potash, fatty amines, uranium, heavy oil, sodium sulfate, chlorine, sodium hydroxide, sodium chlorate and bentonite. Following the successful outcome of the Cluff Lake inquiry, the uranium industry is booming. Some developments and production figures for Gulf Minerals, Amok, Cenex and Eldorado are mentioned.

  1. N-Type delta Doping of High-Purity Silicon Imaging Arrays

    Science.gov (United States)

    Blacksberg, Jordana; Hoenk, Michael; Nikzad, Shouleh

    2005-01-01

    A process for n-type (electron-donor) delta doping has shown promise as a means of modifying back-illuminated image detectors made from n-doped high-purity silicon to enable them to detect high-energy photons (ultraviolet and x-rays) and low-energy charged particles (electrons and ions). This process is applicable to imaging detectors of several types, including charge-coupled devices, hybrid devices, and complementary metal oxide/semiconductor detector arrays. Delta doping is so named because its density-vs.-depth characteristic is reminiscent of the Dirac delta function (impulse function): the dopant is highly concentrated in a very thin layer. Preferably, the dopant is concentrated in one or at most two atomic layers in a crystal plane and, therefore, delta doping is also known as atomic-plane doping. The use of doping to enable detection of high-energy photons and low-energy particles was reported in several prior NASA Tech Briefs articles. As described in more detail in those articles, the main benefit afforded by delta doping of a back-illuminated silicon detector is to eliminate a "dead" layer at the back surface of the silicon wherein high-energy photons and low-energy particles are absorbed without detection. An additional benefit is that the delta-doped layer can serve as a back-side electrical contact. Delta doping of p-type silicon detectors is well established. The development of the present process addresses concerns specific to the delta doping of high-purity silicon detectors, which are typically n-type. The present process involves relatively low temperatures, is fully compatible with other processes used to fabricate the detectors, and does not entail interruption of those processes. Indeed, this process can be the last stage in the fabrication of an imaging detector that has, in all other respects, already been fully processed, including metallized. This process includes molecular-beam epitaxy (MBE) for deposition of three layers, including

  2. Improved γ-linolenic acid production in Mucor circinelloides by homologous overexpressing of delta-12 and delta-6 desaturases.

    Science.gov (United States)

    Zhang, Yao; Luan, Xiao; Zhang, Huaiyuan; Garre, Victoriano; Song, Yuanda; Ratledge, Colin

    2017-06-21

    γ-Linolenic acid (GLA) is important because of its nutritional value and medicinal applications. Although the biosynthetic pathways of some plant and microbial GLA have been deciphered, current understanding of the correlation between desaturases and GLA synthesis in oleaginous fungi is incomplete. In previous work, we found that a large amount of oleic acid (OA) had not been converted to linoleic acid (LA) or GLA in Mucor circinelloides CBS 277.49, which may be due to inadequate activities of the delta-12 or delta-6 desaturases, and thus leading to the accumulation of OA and LA. Thus, it is necessary to explore the main contributing factor during the process of GLA biosynthesis in M. circinelloides. To enhance GLA production in M. circinelloides, homologous overexpression of delta-12 and two delta-6 desaturases (named delta-6-1 and delta-6-2, respectively) were analyzed. When delta-6 desaturase were overexpressed in M. circinelloides, up to 43% GLA was produced in the total fatty acids, and the yield of GLA reached 180 mg/l, which were, respectively, 38 and 33% higher than the control strain. These findings revealed that delta-6 desaturase (especially for delta-6-1 desaturase) plays an important role in GLA synthesis by M. circinelloides. The strain overexpressing delta-6-1 desaturase may have potential application in microbial GLA production.

  3. Being Included and Excluded

    DEFF Research Database (Denmark)

    Korzenevica, Marina

    2016-01-01

    Following the civil war of 1996–2006, there was a dramatic increase in the labor mobility of young men and the inclusion of young women in formal education, which led to the transformation of the political landscape of rural Nepal. Mobility and schooling represent a level of prestige that rural...... politics. It analyzes how formal education and mobility either challenge or reinforce traditional gendered norms which dictate a lowly position for young married women in the household and their absence from community politics. The article concludes that women are simultaneously excluded and included from...... community politics. On the one hand, their mobility and decision-making powers decrease with the increase in the labor mobility of men and their newly gained education is politically devalued when compared to the informal education that men gain through mobility, but on the other hand, schooling strengthens...

  4. [Seasonal variation patterns of NH4(+) -N/NO3(-) -N ratio and delta 15 NH4(+) value in rainwater in Yangtze River Delta].

    Science.gov (United States)

    Xie, Ying-Xin; Zhang, Shu-Li; Zhao, Xu; Xiong, Zheng-Qin; Xing, Guang-Xi

    2008-09-01

    By using a customized manual rainwater sampler made of polyvinyl chloride plastic, the molar ratio of NH4(+) -N/NO3(-) -N and the natural 15N abundance of NH4(+) (delta 15 NH4(+) in rainwater was monitored all year round from June 2003 to July 2005 at three observation sites (Changshu, Nanjing, and Hangzhou) in the Yangtze River Delta. The results indicated that at the three sites, the NH4(+) -N/NO3(-) -N ratio and the delta 15 NH4(+) value in rainwater had the similar seasonal variation trend, being more obvious in Changshu (rural monitoring type) site than in Nanjing (urban monitoring type) and Hangzhou (urban-rural monitoring type) sites. The NH4(+) -N/NO3(-) -N ratio peaked from early June to early August, declined gradually afterwards, and reached the bottom in winter; while the delta 15 NH4(+) value was negative from late June to mid-August, turned positive from late August to mid or late November, became negative again when winter dominated from December to March, but turned positive again in next May and negative again in next July. These seasonal variation patterns of NH4(+) -N/NO3(-) -N ratio and delta 15 NH4(+) value were found in relation to the application of chemical nitrogen fertilizers during different crop growth periods, and also, the alternation of seasons and the NH3 volatilization from other NH3 emission sources (including excrements of human and animals, nitrogen- polluted water bodies, and organic nitrogen sources, etc.), which could be taken as an indicator of defining the sources and form composition of NH4(+) in atmospheric wet deposition and the intensity of various terrestrial NH3 emission sources.

  5. Synoptic Lithostratigraphy of The Niger Delta

    International Nuclear Information System (INIS)

    Nwajide, C.S.

    2002-01-01

    The Tertiary Niger Delta is stratigraphically framed by the Dahomey, Anambra, Abakaliki, Afikpo and Calabar Flank basins. From the apex at Onitsha a fluvial plain splays southwards and translates progressively into a freshwater swamp, succeeded by a mangrove swamp belt. Along the coast is a strip of wave-washed barrier bars indented by large estuaries, fronted by submerged moth bars. Habitation in the delta is on levees, point bars, and barrier bars. These landforms provided the firm salients for buildings the ports that facilitated international trade from the pre-colonial times.There are four lithofacies-clean, pebbly, and muddy sandstones, and mudstones. Their subdivision, based on sedimentary structures, textures and fossil content yields twenty reservoir and seven nonreservoir classes. Their environments of deposition, identified using facies associations, fall into fluvial, wave-and tide-dominated, marginal, and shallow marine, with localised canyons incised into the delta front and filled with deeper marine facies.The reservoirs are composed of 70 90% quartz, 4 15% feldspar, and 3 13% clay matrix, with minor mica, bioclasts, carbonaceous debris, glauconite, and heavy minerals. Grain size varies from very fine to coarse and pebbly, implying the presence of sands of varying textural and compositional maturities. Silica, K-feldspar, and carbonates constitute the cements.Porosity in the reservoirs has remained about the same as at deposition due to low mechanical compaction occasioned by shallow burial. Meteoric water-flushed progradational sequence are characterised by cementation with quartz and kaolinite. In contrast, marine water-flushed transgressive sands show grain coating illite-smectite, chlorite and K-feldspar overgrowths

  6. THE RURAL TOURISM IN DANUBE DELTA

    Directory of Open Access Journals (Sweden)

    Ionica SOARE

    2014-06-01

    Full Text Available Purpose - the purpose of this paper is to evaluate the rural areas has market size and forecast its development as an economic activity. The present paper aims at analyzing the rural areas has in Danube Delta. In an enviable BAs which have responsibility for their particular isolated, such as the Danube Delta and the Danube that used, fishing and rural areas has the main activities that provide jobs and income sources for local populations. Design/methodology/approach - A survey was administered to customers’ rural hostel accommodation in Danube Delta. Descriptive statistics method was mainly adopted to calculate the mean with standard deviation of entry assumes variable, and to examine the different levels of consumers' awareness. The index values of product familiarity, the ratio between entries assumes product's familiarity value and the average value. Findings - the research results show hash has rural consumers have different perception and accomplished through behaviour. The information channels of brand hash mainly from friends, relatives and neighbours, so word of mouth spreading is very important for a brand. Women show a higher sensitivity in health and are currently operating the propensity than referred to follow the recommendations for nutrition. Research limitations/implications - This item is intended to synthesize developments and challenges," on June 13th rural market growth has. The results of this paper should be considered tentatively until has also features replicated by larger has rural consumers. Originality/value - members of rural areas has consumer's behavior would improve marketing and the development of rural areas has products, in order to reduce consumer confusion.

  7. Stratigraphy and Evolution of Delta Channel Deposits, Jezero Crater, Mars

    Science.gov (United States)

    Goudge, T. A.; Mohrig, D.; Cardenas, B. T.; Hughes, C. M.; Fassett, C. I.

    2017-01-01

    The Jezero impact crater hosted an open-basin lake that was active during the valley network forming era on early Mars. This basin contains a well exposed delta deposit at the mouth of the western inlet valley. The fluvial stratigraphy of this deposit provides a record of the channels that built the delta over time. Here we describe observations of the stratigraphy of the channel deposits of the Jezero western delta to help reconstruct its evolution.

  8. Tracks, spurs, blobs and delta-rays

    International Nuclear Information System (INIS)

    Magee, J.L.; Chatterjee, A.

    1983-01-01

    The track of a high-energy particle is the collection of all transient species created by the particle in the total degradation of its energy. Visible electron tracks are called delta rays. A microscopic description of the track with all its knocked-out electrons leads to spurs, blobs, and short tracks. Energy deposition criteria for these three track entities are 6 to 100 eV, 100 to 500 eV, and 500 eV to 5 keV, respectively

  9. The situation in the Niger Delta

    International Nuclear Information System (INIS)

    Vitalis, E.

    2007-01-01

    An energy issue for the United States and a political challenge for Europe, Nigeria is experiencing growing instability and is on the verge of civil war; the ecosystem and the population of the Niger Delta are the main victims. The State, corrupt, is powerless to contain the rising violence and redistribute the proceeds of oil sales. It is high time for oil-consuming countries, starting with the United States, to concern themselves with stabilizing the region. Europe must contribute to the lasting development of this country. (author)

  10. Adaptive delta management: a comparison between the Netherlands and Bangladesh Delta Program

    NARCIS (Netherlands)

    Zevenbergen, Chris; Khan, Shah Alam; Alphen, van Jos; Terwisscha van Scheltinga, Catharien; Veerbeek, William

    2018-01-01

    In the Netherlands, the central government, water authorities, provinces and municipalities are working together on a new Delta Program on Flood Risk Management and Fresh Water Supply (DP). Its primary goal is to protect the Netherlands against floods and ensure the availability of fresh water, now

  11. Tidal modulated flow and sediment flux through Wax Lake Delta distributary channels: Implications for delta development

    Directory of Open Access Journals (Sweden)

    K. Hanegan

    2015-03-01

    Full Text Available In this study, a Delft3D model of the Wax Lake Delta was developed to simulate flow and sediment flux through delta distributary channels. The model was calibrated for tidal constituents as well as velocity and sediment concentration across channel transects. The calibrated model was then used to simulate full spring–neap tidal cycles under constant low flow upstream boundary conditions, with grain size variation in suspended load represented using two sediment fractions. Flow and sediment flux results through distributary channel cross-sections were examined for spatial and temporal variability with the goal of characterizing the role of tides in sediment reworking and delta development. The Wax Lake Delta has prograded through channel extension, river mouth bar deposition, and channel bifurcation. Here we show that tidal modulation of currents influences suspended sand transport, and spatial acceleration through distributary channels at low tides is sufficient to suspend sand in distal reaches during lower flows. The basinward-increasing transport capacity in distributary channels indicates that erosive channel extension could be an important process, even during non-flood events.

  12. Delta Plaza kohvik = The Delta Plaza Café / Margit Mutso

    Index Scriptorium Estoniae

    Mutso, Margit, 1966-

    2010-01-01

    Tallinnas Pärnu mnt. 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Hoone arhitektid Jüri Okas ja Marika Lõoke (AB J. Okas & M. Lõoke). Žürii liikme Mait Summataveti arvamus kohvikust

  13. Studying medium effects with the optimized {delta} expansion

    Energy Technology Data Exchange (ETDEWEB)

    Krein, G [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Menezes, D P [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Fisica; Nielsen, M [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Pinto, M B [Montpellier-2 Univ., 34 (France). Lab. de Physique Mathematique

    1995-04-01

    The possibility of using the optimized {delta} expansion for studying medium effects on hadronic properties in quark or nuclear matter is investigated. The {delta} expansion is employed to study density effects with two commonly used models in hadron and nuclear physics, the Nambu-Jona-Lasinio model for the dynamical chiral symmetry breaking and the Walecka model for the equation of state of nuclear matter. The results obtained with the {delta} expansion are compared to those obtained with the traditional Hartree-Fock approximation. Perspectives for using the {delta} expansion in other field theoretic models in hadron and nuclear physics are discussed. (author). 17 refs, 9 figs.

  14. Optimality and self-organization in river deltas

    Science.gov (United States)

    Tejedor, A.; Longjas, A.; Edmonds, D. A.; Zaliapin, I. V.; Georgiou, T. T.; Rinaldo, A.; Foufoula-Georgiou, E.

    2017-12-01

    Deltas are nourished by channel networks, whose connectivity constrains, if not drives, the evolution, functionality and resilience of these systems. Understanding the coevolution of deltaic channels and their flux organization is crucial for guiding maintenance strategies of these highly stressed systems from a range of anthropogenic activities. However, in contrast to tributary channel networks, to date, no theory has been proposed to explain how deltas self-organize to distribute water and sediment to the delta top and the shoreline. Here, we hypothesize the existence of an optimality principle underlying the self-organized partition of fluxes in delta channel networks. Specifically, we hypothesize that deltas distribute water and sediment fluxes on a given delta topology such as to maximize the diversity of flux delivery to the shoreline. By introducing the concept of nonlocal Entropy Rate (nER) and analyzing ten field deltas in diverse environments, we present evidence that supports our hypothesis, suggesting that delta networks achieve dynamically accessible maxima of their nER. Furthermore, by analyzing six simulated deltas using the Delf3D model and following their topologic and flux re-organization before and after major avulsions, we further study the evolution of nER and confirm our hypothesis. We discuss how optimal flux distributions in terms of nER, when interpreted in terms of resilience, are configurations that reflect an increased ability to withstand perturbations.

  15. The political economy of oil and the Niger Delta crisis

    Science.gov (United States)

    Ighodaro, Osaro O.

    This study is about the burgeoning crisis in Nigeria's Oil Producing Niger Delta region. Discerning the intersecting contributive factors to the crisis, this dissertation suggests that the Niger Delta crisis is symptomatic of challenges to development in Nigeria. Due to the insidious colonial/neo-colonial practices of subjugation, and exploitation of the host communities, it is suggested that the extractive, super-profit motive of Shell, the concomitant environmental degradation, corruption of a bellicose state, ethnic conflict and suffering of the masses are outcomes of a long historically debilitating relationship with international capital which causes irreparable retardation to the host communities. From cash crop economy to a mono-oil economy resources are removed from the communities and used to enhance the colonial state and their post-colonial harbingers of misery. Hence, the indigenous people claim that the Niger Delta is in a crisis, and they are willing to confront the triple alliance of multinational oil companies like Shell, the Nigerian State and the local elite so long as these allies of subjugation continue to neglect the goose that lays the proverbial golden egg (oil that is). Theoretically, a hybrid Political Economy approach was adopted as the over-aching framework for the study, while Dependency theory, modified by what I have called African Transformative scholarly perspective, served as the conceptual tool. Primary and secondary sources of data, including personal observation, interviews, official government documents and other publications were utilized for this analysis. In view of recommendations, it is suggested that first, the Nigerian state should assume decisive and unflinching leadership in holding oil companies responsible for their activities in the host communities; second, oil companies (like Shell) should see themselves as an integral part of the host communities; invest in their development by providing employment opportunities

  16. Using ground-based geophysics to constrain the interpretation of airborne TEM data recorded across the Okavango Delta, Botswana

    Science.gov (United States)

    Podgorski, J. E.; Kalscheuer, T.; Doetsch, J.; Rabenstein, L.; Tshoso, G.; Meier, P.; Horstmeyer, H.; Kgotlhang, L.; Ploug, C.; Auken, E.; Kinzelbach, W. K.; Green, A. G.

    2011-12-01

    The Okavango Delta in northern Botswana is a near endorheic inland delta that has developed over the past ~2 MA in an active graben at the southwestern end of the East Africa Rift System. An annual flood from the north causes a slowly flowing surface water regime in the delta, but previous wetter climatic periods were responsible for intermittent lacustrine environments. The Okavango Delta is the largest permanent water body in the Kalahari Desert and, as such, represents an important resource for wildlife and humans alike. An airborne time-domain electromagnetic (TEM) survey, commissioned by the Botswana government, was undertaken in 2007 for the purpose of better understanding the hydrogeology of the delta. Initial processing and inversion of these data show within the main fan of the delta a resistive 20-50 m thick surface layer underlain by a 30-200 m thick conductive layer. In the upper fan, the conductive layer is underlain by a resistive unit beginning at about 150 m depth. This unit exhibits a dendritic pattern implying a fluvial origin. To help interpret this and other structures, geophysical field work was initiated in early 2011 at various locations in the delta. Seismic reflection and refraction, electrical resistive tomography (ERT), and ground TEM methods were employed. The seismic methods are useful for delineating the boundaries of the weathering and basement layers, whereas ERT provides an independent estimate of the resistivity structure, particularly at shallow depths. Ground TEM allows for a direct comparison with the airborne TEM soundings, helping to estimate the accuracy of the latter. Though still evolving, the current large-scale hydrogeological interpretation of the airborne data set includes a fresh water-saturated surface layer underlain by a saline aquifer and clay aquitard. In the upper fan of the delta, a fresh water aquifer appears to lie between the aquitard and the basement rock.

  17. Catalyzing action towards the sustainability of deltas: deltas as integrated socio-ecological systems and sentinels of regional and global change

    Science.gov (United States)

    Foufoula-Georgiou, E.; Tessler, Z. D.; Brondizio, E.; Overeem, I.; Renaud, F.; Sebesvari, Z.; Nicholls, R. J.; Anthony, E.

    2016-12-01

    Deltas are highly dynamic and productive environments: they are food baskets of the world, home to biodiverse and rich ecosystems, and they play a central role in food and water security. However, they are becoming increasingly vulnerable to risks arising from human activities, land subsidence, regional water management, global sea-level rise, and climate extremes. Our Belmont Forum DELTAS project (BF-DELTAS: Catalyzing actions towards delta sustainability) encompasses an international network of interdisciplinary research collaborators with focal areas in the Mekong, Ganges Brahmaputra, and the Amazon deltas. The project is organized around five main modules: (1) developing an analytical framework for assessing delta vulnerability and scenarios of change (Delta-SRES), (2) developing an open-acess, science-based integrative modeling framework for risk assessment and decision support (Delta-RADS), (3) developing tools to support quantitative mapping of the bio-physical and socio-economic environments of deltas and consolidate bio-physical and social data within shared data repositories (Delta-DAT), (4) developing Global Delta Vulnerability Indices (Delta-GDVI) that capture current and projected scenarios for major deltas around the world , and (5) collaborating with regional stakeholders to put the science, modeling, and data into action (Delta-ACT). In this talk, a research summary will be presented on three research domains around which significant collaborative work was developed: advancing biophysical classification of deltas, understanding deltas as coupled socio-ecological systems, and analyzing and informing social and environmental vulnerabilities in delta regions.

  18. A new seamless, high-resolution digital elevation model of the San Francisco Bay-Delta Estuary, California

    Science.gov (United States)

    Fregoso, Theresa A.; Wang, Rueen-Fang; Ateljevich, Eli; Jaffe, Bruce E.

    2017-06-14

    Climate change, sea-level rise, and human development have contributed to the changing geomorphology of the San Francisco Bay - Delta (Bay-Delta) Estuary system. The need to predict scenarios of change led to the development of a new seamless, high-resolution digital elevation model (DEM) of the Bay – Delta that can be used by modelers attempting to understand potential future changes to the estuary system. This report details the three phases of the creation of this DEM. The first phase took a bathymetric-only DEM created in 2005 by the U.S. Geological Survey (USGS), refined it with additional data, and identified areas that would benefit from new surveys. The second phase began a USGS collaboration with the California Department of Water Resources (DWR) that updated a 2012 DWR seamless bathymetric/topographic DEM of the Bay-Delta with input from the USGS and modifications to fit the specific needs of USGS modelers. The third phase took the work from phase 2 and expanded the coverage area in the north to include the Yolo Bypass up to the Fremont Weir, the Sacramento River up to Knights Landing, and the American River up to the Nimbus Dam, and added back in the elevations for interior islands. The constant evolution of the Bay-Delta will require continuous updates to the DEM of the Delta, and there still are areas with older data that would benefit from modern surveys. As a result, DWR plans to continue updating the DEM.

  19. More than 100 Years of Background-Level Sedimentary Metals, Nisqually River Delta, South Puget Sound, Washington

    Science.gov (United States)

    Takesue, Renee K.; Swarzenski, Peter W.

    2011-01-01

    The Nisqually River Delta is located about 25 km south of the Tacoma Narrows in the southern reach of Puget Sound. Delta evolution is controlled by sedimentation from the Nisqually River and erosion by strong tidal currents that may reach 0.95 m/s in the Nisqually Reach. The Nisqually River flows 116 km from the Cascade Range, including the slopes of Mount Rainier, through glacially carved valleys to Puget Sound. Extensive tidal flats on the delta consist of late-Holocene silty and sandy strata from normal river streamflow and seasonal floods and possibly from distal sediment-rich debris flows associated with volcanic and seismic events. In the early 1900s, dikes and levees were constructed around Nisqually Delta salt marshes, and the reclaimed land was used for agriculture and pasture. In 1974, U.S. Fish and Wildlife Service established the Nisqually National Wildlife Refuge on the reclaimed land to protect migratory birds; its creation has prevented further human alteration of the Delta and estuary. In October 2009, original dikes and levees were removed to restore tidal exchange to almost 3 km2 of man-made freshwater marsh on the Nisqually Delta.

  20. Superconducting bandpass delta-sigma modulator

    International Nuclear Information System (INIS)

    Bulzacchelli, J.F.; Lee, H.-S.; Misewich, J.A.; Ketchen, M.B.

    1999-01-01

    Bandpass delta-sigma modulators digitize narrowband signals with high dynamic range and linearity. The required sampling rate is only a few times higher than the centre frequency of the input. This paper presents a superconducting bandpass delta-sigma modulator for direct analogue-to-digital conversion of RF signals in the GHz range. The input signal is capacitively coupled to one end of a microstrip transmission line, and a single flux quantum balanced comparator quantizes the current flowing out of the other end. Quantization noise is suppressed at the quarter-wave resonance of the transmission line (about 2 GHz in our design). Circuit performance at a 20 GHz sampling rate has been studied with several long JSIM simulations. Full-scale (FS) input sensitivity is 20 mV (rms), and in-band noise is -53 dBFS and -57 dBFS over bandwidths of 39 MHz and 19.5 MHz, respectively. In-band intermodulation distortion is better than -69 dBFS. (author)

  1. In vivo metabolism of the methyl homologues of delta-8-tetrahydrocannabinol, delta-9-tetrahydrocannabinol and abn-delta-8-tetrahydrocannabinol in the mouse.

    Science.gov (United States)

    Brown, N K; Harvey, D J

    1988-04-01

    Methyl-delta-8-tetrahydrocannabinol (methyl-delta-8-THC), methyl-delta-9-THC and abn-methyl-delta-8-THC were synthesized by condensation of orcinol and (1S)-cis-verbenol and were administered to male Charles River CD-1 mice. Extracted hepatic metabolites were isolated by chromatography on Sephadex LH-20 and examined by gas chromatography/mass spectrometry as trimethylsilyl (TMS), (2H9)TMS and methyl ester/TMS derivatives. In addition, metabolic fractions were reduced with lithium aluminium deuteride to convert carboxylic acids to alcohols for structural correlation. Metabolites from methyl-delta-8-THC were similar with respect to the positions substituted to those produced by higher homologues; the major metabolite was methyl-delta-8-THC-11-oic acid. abn-Methyl-delta-8-THC was metabolized in a different manner. The location of the aromatic methyl group at the position adjacent to ring fusion appeared to inhibit metabolism at C(11) to a considerable extent and also to reduce the amount of the resulting alcohol from being oxidized to a carboxylic acid. This caused other metabolic pathways to become dominant, with the result that a compound containing a hydroxy group at the gem-methyl position was the major metabolite. Hydroxylation at this position has not been confirmed with any other cannabinoid, although it is thought to result in trace concentrations of hydroxy metabolites from some compounds. Metabolism of methyl-delta-9-THC was also similar to that of the higher homologues, with the exception that less metabolism occurred at C(8) and a higher percentage of the total metabolic fraction was accounted for by the 11-oic acid metabolite. Minor metabolites were mainly dihydroxy compounds and hydroxylated derivatives of delta-9-THC-11-oic acid.

  2. Land Resources Evaluation Of The Paleodarainage Delta In Western Desert Of Egypt Using Remote Sensing Data

    International Nuclear Information System (INIS)

    Afify, A.A.

    2009-01-01

    The study area was selected to represent the sediments of paleodrainage delta in the Western Desert of Egypt, covering about 15615653 feddans (6561199 hectares). The data of Landsat Enhanced Thematic Mapper (ETM) 2002 were used for delineating the physiographic units to be a base for the soil taxonomic units (all are hyperthermic). These taxonomic units were potentially evaluated for barley and wheat (grain crops), alfalfa (fodder crop), maize, sun flower and olives (oil seed crops). The illustrated flow of the paleodrainage delta starts from the south as undulating delta apex, which most probably was deposited by the paleodrainage from Eastern Desert through the different rock structures. This apex includes soils of Calcic Petrogypsids loamy skeletal, gypsic; Typic Clacigypsids, loamy skeletal, gypsic and Typic Calcigypsids, sandy skeletal, mixed. The unit is profitable for drip irrigated olives as moderately to marginally suitable and for quarrying Oligocene gravel. Gently undulating inter delta includes sediments that was most probably received by reworking and out washing the slopes of delta apex in relatively more recent fluvial eras. The soils are Typic Calcigypsids, fine loamy, mixed; Typic Calcigypsids, loamy skeletal, mixed and Typic Calcigypsids, sandy, mixed. This unit is profitable for drip irrigated olives as highly suitable and sprinkly irrigated alfalfa, maize and sun flower as marginally suitable. Gently undulating to almost flat inter delta is most probably received its sediments from the southern physiographic units by the paleodrainage erosion. The soils are Leptic Haplogypsids, fine loamy, mixed and Leptic Haplogypsid, sandy, mixed. This unit is profitable for drip irrigated olives as moderately suitable. In the middle front of this unit, a township is proposed to be constructed A I Qattara Town . Flat depressed pro delta includes interfered sediments of different paleodrainage eras being received medium soil matrix over relatively old sediments

  3. The Concentration Dependence of the (Delta)s Term in the Gibbs Free Energy Function: Application to Reversible Reactions in Biochemistry

    Science.gov (United States)

    Gary, Ronald K.

    2004-01-01

    The concentration dependence of (delta)S term in the Gibbs free energy function is described in relation to its application to reversible reactions in biochemistry. An intuitive and non-mathematical argument for the concentration dependence of the (delta)S term in the Gibbs free energy equation is derived and the applicability of the equation to…

  4. Complex rearrangements within the human J delta-C delta/J alpha-C alpha locus and aberrant recombination between J alpha segments

    NARCIS (Netherlands)

    Baer, R.; Boehm, T.; Yssel, H.; Spits, H.; Rabbitts, T. H.

    1988-01-01

    We have examined DNA rearrangements within a 120 kb cloned region of the human T cell receptor J delta-C delta/J alpha-C alpha locus. Three types of pattern emerge from an analysis of T cell lines and clones. Firstly, cells with two rearrangements within J delta-C delta; secondly, cells with one

  5. Spatio-temporal distributions of delta18O, delta D and salinity in the Arabian Sea: Identifying processes and controls

    Digital Repository Service at National Institute of Oceanography (India)

    Deshpande, R.D; Muraleedharan, P.M.; Singh, R.L.; Kumar, B.; Rao, M.S.; Dave, M.; Sivakumar, K.U.; Gupta, S.K.

    the geographic distributions of the delta18O and S; (2) in spite of a large scatter, a statistically significant delta18O–S relationship can be identified in much of the investigated part of the AS; (3) the delta18Odelta...

  6. 78 FR 21491 - DeltaPoint Capital IV, L.P., DeltaPoint Capital IV (New York), L.P.; Notice Seeking Exemption...

    Science.gov (United States)

    2013-04-10

    ... SMALL BUSINESS ADMINISTRATION [License No. 02/02-0662, 02/02-0661] DeltaPoint Capital IV, L.P., DeltaPoint Capital IV (New York), L.P.; Notice Seeking Exemption Under Section 312 of the Small Business Investment Act, Conflicts of Interest Notice is hereby given that DeltaPoint Capital IV, L.P. and DeltaPoint...

  7. Changes to subaqueous delta bathymetry following a high river flow event, Wax Lake Delta, LA, USA

    Science.gov (United States)

    Whaling, A. R.; Shaw, J.

    2017-12-01

    Sediment transport capacity is increased during high river flow (flood) events which are characterized by discharges that exceed the 15 year median daily statistic. The Wax Lake Delta (WLD) in coastal Louisiana has experienced 19 of these high flow events in the past 20 years, yet the depositional patterns of single floods are rarely measured in a field-scale deltaic setting. We characterize flood deposition and erosion patterns on the subaqueous portion of the WLD by differencing two Digital Elevation Models (DEMs) constructed from bathymetric surveys before and after the third largest flood in the WLD's recorded history. The total suspended sediment discharge for the 496 day inter-survey period was 2.14x107 cubic meters measured 21 km upstream of the delta apex. The difference map showed 1.06x107 cubic meters of sediment was deposited and 8.2x106 cubic meters was eroded, yielding 2.40x106 cubic meters of net deposition in the survey area ( 79.7 km2 ). Therefore the average deposition rate was 0.061 mm/day. Channel planform remained relatively unchanged for five out of six distributary passes however Gadwall Pass experienced a maximum channel displacement of 166 m ( 1 channel width) measured from the thalweg centerline. Channel tip extension was negligible. In addition, channel displacement was not concentrated at any portion along the channel centerline. Maximum erosion occurred within channel margins and increased upstream whereas maximum deposition occurred immediately outside the channel margins. Sediment eroded from the survey area was either subsequently re-deposited or transported out of the system. Our results show that up to 77.4% of deposition in the survey area originated from sediment eroded during the flood. Surprisingly, only 11.2% of the total suspended sediment discharge was retained in the subaqueous portion of the delta after the flood. We conclude that a high flow event does not produce channel progradation. Rather, high flow causes delta

  8. Virus diseases risk-factors associated with shrimp farming practices in rice-shrimp and intensive culture systems in Mekong Delta Viet Nam

    NARCIS (Netherlands)

    Duc, P.M.; Tuyet Hoa, T.T.; Nguyen Thanh Phuong,; Bosma, R.H.; Huynh V., Hien; Tran N., Tuan

    2015-01-01

    In Mekong Delta, viral infection, including white spot syndrome virus (WSSV), monodon baculovirus (MBV), heptopancreatic parvovirus (HPV), infectious hypodermal and hematopoietic necrosis virus (IHHNV) and gill-associated nidovirus (GAV) frequently infect cultured shrimp starting at the postlarvae

  9. Nitrogen content and delta N-15 of marine algae and associated waters of Maui, Hawaii, from 2012-07-28 to 2014-04-01 (NCEI Accession 0156294)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set includes nutrient data related to algal and water samples collected between 2012 and 2014 on Maui, Hawaii. Algal tissue N%, C:N ratios, and delta N-15...

  10. Niger Delta Crisis and Security Implications for the Nation State ...

    African Journals Online (AJOL)

    The Niger Delta is the nation's treasure base, the Niger Delta provides over 80 percent of government revenue, 95 percent of export receipts, and 90 percent of ... The government should tackle the fundamental issue of basic necessities – provision of good motorable roads, pipe borne water, electricity, good hospitals, good ...

  11. Morphodynamics of the Manyema tidal delta 1 LIST OF TABLES ...

    African Journals Online (AJOL)

    Kheira Kortenbout

    Morphodynamics of the Manyema tidal delta. 1. LIST OF ... Location of Manyema Creek and its associated tidal delta platform at Kunduchi. Fig. 2. ... platform. Beachcomber. Hotel. Whitesands. Hotel. Kunduchi. Beach Hotel. Giraffe. Hotel. INDIAN. OCEAN. Mombasa. Dar es. Salaam. KUNDUCHI. KENYA. TANZANIA.

  12. Towards a Comprehensive Framework for Adaptive Delta Management

    NARCIS (Netherlands)

    Marchand, M.; Ludwig, F.

    2014-01-01

    Deltas are dynamic landforms at the boundary of land and sea, involving intricate mazes of rivers and small waterways, wetlands, estuaries and coastal barrier islands. They are home to over half a billion people. Deltas are also home to rich ecosystems, such as mangroves and marshes. They are

  13. Conflict resolution among Niger delta communities: A historical ...

    African Journals Online (AJOL)

    Conflict related issues have assumed endemic proportion in the Niger Delta. A proper assessment of the critical factors in motion must take cognizance of their historical underpinnings. Peaceful co-existence, the hallmark of conflict resolution, can be feasible in the Niger Delta, through sustainable dialogue. These, among

  14. Caribbean piracy and youth restiveness in Niger delta: A ...

    African Journals Online (AJOL)

    Our aim in this paper is to make a comparative analysis of Caribbean piracy and youth restiveness in Niger Delta of Nigeria. It will not be out of place to carry out such an analysis having seen, heard or read of the ongoing chaos, insecurity in the. Niger Delta Zone in Nigeria. We have to look at the past to find out such similar

  15. 78 FR 45592 - DeltaPoint Capital IV, LP;

    Science.gov (United States)

    2013-07-29

    ..., Suite 160, Pittsford, NY 14534. The financing was contemplated for working capital. The financing is... SMALL BUSINESS ADMINISTRATION [License No. 02/02-0662] DeltaPoint Capital IV, LP; Notice Seeking... given that DeltaPoint Capital IV, L.P., 45 East Avenue, 6th Floor, Rochester, NY 14604, Federal...

  16. Central Delta languages: An overview | Kari | Stellenbosch Papers ...

    African Journals Online (AJOL)

    This paper presents an overview of the phonology, morphology and syntax of Central Delta languages. It also provides information on the geo-linguistic, demographic and sociolinguistic situation of these languages. It notes that Central Delta languages have a 20-vowel system, which divides into two sets of 10 vowels ...

  17. Downstream hydraulic geometry of a tidally influenced river delta

    NARCIS (Netherlands)

    Sassi, M.G.; Hoitink, A.J.F.; Brye, de B.; Deleersnijder, E.

    2012-01-01

    Channel geometry in tidally influenced river deltas can show a mixed scaling behavior between that of river and tidal channel networks, as the channel forming discharge is both of river and tidal origin. We present a method of analysis to quantify the tidal signature on delta morphology, by

  18. Delta: the first pion nucleon resonance - its discovery and applications

    International Nuclear Information System (INIS)

    Nagle, D.E.

    1984-07-01

    It is attempted to recapture some of the fun and excitement of the pion-scattering work that led to the discovery of what is now called the delta particle. How significant this discovery was became apparent only gradually. That the delta is alive today and thriving at Los Alamos (as well as other places) is described

  19. Wastewater disposal at safari lodges in the Okavango Delta, Botswana

    African Journals Online (AJOL)

    Wastewater disposal at safari lodges in the Okavango Delta, Botswana. TS McCarthy, T Gumbricht, RG Stewart, D Brandt, PJ Hancox, J McCarthy, AG Duse. Abstract. Many safari lodges in the Okavango Delta obtain their water supply from boreholes in near-surface aquifers while disposing of their wastewater via ...

  20. Remote stereocontrol by sulfinyl groups: reduction of delta-ketosulfoxides.

    Science.gov (United States)

    García Ruano, José L; Fernández-Ibáñez, M Angeles; Maestro, M Carmen; Rodríguez-Fernández, M Mercedes

    2005-03-04

    The reduction of delta-ketosulfoxides constitutes the first evidence of the efficiency of the sulfinyl group to control the stereoselectivity of 1,5-asymmetric induction processes. The use of DIBAL/Yb(OTf)3 or L-Selectride as the reducing agents provides delta-hydroxysulfoxides with the opposite configuration at the hydroxylic carbon in a highly stereoselective way.

  1. Quark sea and the. delta. I=1/2 rule

    Energy Technology Data Exchange (ETDEWEB)

    Donoghue, J F [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics; Golowich, E [Massachusetts Univ., Amherst (USA)

    1977-08-29

    The effect on nonleptonic processes of quark-antiquark pairs due to quantum chromodynamics is studied. Their presence improves agreement between theory and experiment for hyperon decays. In kaon decays a new ..delta..I=1/2 contribution is found, but ..delta..I=3/2 effects are still too large to be in agreement.

  2. Antinociceptive activity of Delta9-tetrahydrocannabinol non-ionic microemulsions.

    Science.gov (United States)

    Lazzari, P; Fadda, P; Marchese, G; Casu, G L; Pani, L

    2010-06-30

    Delta(9)-Tetrahydrocannabinol (Delta(9)-THC), the major psychoactive constituent of Cannabis sativa L., has been widely studied for its potential pharmaceutical application in the treatment of various diseases and disturbs. This sparingly soluble terpeno-phenolic compound is not easy to handle and to be formulated in pharmaceutical preparations. The aim of this work was to develop a stable aqueous Delta(9)-THC formulation acceptable for different ways of administration, and to evaluate the therapeutic properties of the new Delta(9)-THC based preparation for pain treatment. Due to the thermodynamic stability and advantages of microemulsion based systems, the study was focused on the identification of aqueous microemulsion based systems containing Delta(9)-THC. Oil in water Delta(9)-THC microemulsions were individuated through phase diagrams construction, using the non-ionic surfactant Solutol HS15, being this surfactant acceptable for parenteral administration in human. A selected microemulsion samples containing 0.2 wt% of Delta(9)-THC, stable up to 52 degrees C, was successfully assayed on animal models of pain. Significant antinociceptive activity has been detected by both intraperitoneal and intragastric administration of the new Delta(9)-THC pharmaceutical preparation. The effect has been highlighted in shorter time if compared to a preparation of the same active principle based on previously reported conventional preparation. 2010 Elsevier B.V. All rights reserved.

  3. An annotated list of Fishes from the Niger Delta

    NARCIS (Netherlands)

    Boeseman, M.

    1963-01-01

    At the end of November 1960, the Leiden Museum received an interesting collection of animals, mostly fishes, from the Niger delta. All specimens were collected by Mr. H. J. G. Beets, at the time employed by Shell B.P. — Delta Investigations, during the period May to August 1960, and in the region

  4. Topological Mappings via Bδg-Closed Sets

    OpenAIRE

    Maruthamuthu, Raja; Narayanasamy, Seenivasagan; Otchanathevar, Ravi

    2018-01-01

    In this paper we introduce a new class of functions called  Bδg-continuous functions. We obtain several characterizations and some their properties. Also we investigate its relationship with other types of functions. Further we introduce and study a new class of functions namely Bδg-irresolute.

  5. Estimation of Thermal Conductivity in the North- Western Niger Delta ...

    African Journals Online (AJOL)

    Thermal conductivity estimates are computed from nineteen petroleum wells in the north-western Niger Delta, Nigeria, using a geometric mean model. Sonic and gamma-ray logs were digitised and used in the estimation of in situ conductivity. The Niger Delta is composed of three major diachronous lithostratigraphic units of ...

  6. How to deal with subsidence in the Dutch delta?

    NARCIS (Netherlands)

    Stouthamer, E.; Erkens, G.

    2017-01-01

    In many deltas worldwide subsidence still is an underestimated problem, while the threat posed by land subsidence low-lying urbanizing and urbanized deltas exceeds the threat of sea-level rise induced by climate change. Human-induced subsidence is driven by the extraction of hydrocarbons and

  7. Dousing the tension in the Niger delta through administrative agency

    African Journals Online (AJOL)

    Dousing the tension in the Niger delta through administrative agency: A programme evaluation of Niger delta development commission as an intervention regime. ... the study concludes that because of systemic constraints arising from the hegemonic interests of the dominant coalitions in the Nigerian Social formation, ...

  8. Drones on the delta | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    25 nov. 2016 ... Waves wash ashore at Fuvemeh, a town in Ghana's Volta River delta that's threatened by coastal erosion and flooding. Brian Owens, Canadian Geographic. Ghana's Volta River delta is an area vulnerable to climate change, with rising seas and increasingly powerful storms driving flooding and erosion, ...

  9. Homosexuality amongst migrant oil workers in the Niger Delta ...

    African Journals Online (AJOL)

    Aims: To determine the prevalence of homosexuality among migrant oil workers in Niger Delta. Methods: A prospective questionnaire – based study was conducted among migrant oil workers in the Niger Delta region of Nigeria. The design was to determine the prevalence of homosexuality in the workers in oil workers.

  10. T gamma/delta lymphocytes in renal transplant recipients

    NARCIS (Netherlands)

    Raasveld, M. H.; Bloemena, E.; Surachno, S.; ten Berge, R. J.

    1992-01-01

    T gamma/delta lymphocytes are able to perform allospecific cytotoxicity and natural killer cytotoxicity in vitro. However, very little is known about their function in vivo. To investigate the possible involvement of T gamma/delta lymphocytes in the immune response to renal allografts, fine-needle

  11. CFD analysis of fin tube heat exchanger with a pair of delta winglet vortex generators

    International Nuclear Information System (INIS)

    Hwang, Seong Won; Kim, Dong Hwan; Min, June Kee; Jeong, Ji Hwan

    2012-01-01

    Among tubular heat exchangers, fin tube types are the most widely used in refrigeration and air-conditioning equipment. Efforts to enhance the performance of these heat exchangers included variations in the fin shape from a plain fin to a slit and louver type. In the context of heat transfer augmentation, the performance of vortex generators has also been investigated. Delta winglet vortex generators have recently attracted research interest, partly due to experimental data showing that their addition to fin-tube heat exchangers considerably reduces pressure loss at heat transfer capacity of nearly the same level. The efficiency of the delta winglet vortex generators widely varies depending on their size and shape, as well as the locations where they are implemented. In this paper, the flow field around delta winglet vortex generators in a common flow up arrangement was analyzed in terms of flow characteristics and heat transfer using computational fluid dynamics methods. Flow mixing due to vortices and delayed separation due to acceleration influence the overall fin performance. The fin with delta winglet vortex generators exhibited a pressure loss lower than that of a plain fin, and the heat transfer performance was enhanced at high air velocity or Reynolds number

  12. Numerical simulation of incidence and sweep effects on delta wing vortex breakdown

    Science.gov (United States)

    Ekaterinaris, J. A.; Schiff, Lewis B.

    1994-01-01

    The structure of the vortical flowfield over delta wings at high angles of attack was investigated. Three-dimensional Navier-Stokes numerical simulations were carried out to predict the complex leeward-side flowfield characteristics, including leading-edge separation, secondary separation, and vortex breakdown. Flows over a 75- and a 63-deg sweep delta wing with sharp leading edges were investigated and compared with available experimental data. The effect of variation of circumferential grid resolution grid resolution in the vicinity of the wing leading edge on the accuracy of the solutions was addressed. Furthermore, the effect of turbulence modeling on the solutions was investigated. The effects of variation of angle of attack on the computed vortical flow structure for the 75-deg sweep delta wing were examined. At moderate angles of attack no vortex breakdown was observed. When a critical angle of attack was reached, bubble-type vortex breakdown was found. With further increase in angle of attack, a change from bubble-type breakdown to spiral-type vortex breakdown was predicted by the numerical solution. The effects of variation of sweep angle and freestream Mach number were addressed with the solutions on a 63-deg sweep delta wing.

  13. CFD analysis of fin tube heat exchanger with a pair of delta winglet vortex generators

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Seong Won; Kim, Dong Hwan; Min, June Kee; Jeong, Ji Hwan [Pusan National Univ., Busan (Korea, Republic of)

    2012-09-15

    Among tubular heat exchangers, fin tube types are the most widely used in refrigeration and air-conditioning equipment. Efforts to enhance the performance of these heat exchangers included variations in the fin shape from a plain fin to a slit and louver type. In the context of heat transfer augmentation, the performance of vortex generators has also been investigated. Delta winglet vortex generators have recently attracted research interest, partly due to experimental data showing that their addition to fin-tube heat exchangers considerably reduces pressure loss at heat transfer capacity of nearly the same level. The efficiency of the delta winglet vortex generators widely varies depending on their size and shape, as well as the locations where they are implemented. In this paper, the flow field around delta winglet vortex generators in a common flow up arrangement was analyzed in terms of flow characteristics and heat transfer using computational fluid dynamics methods. Flow mixing due to vortices and delayed separation due to acceleration influence the overall fin performance. The fin with delta winglet vortex generators exhibited a pressure loss lower than that of a plain fin, and the heat transfer performance was enhanced at high air velocity or Reynolds number.

  14. Modeling multi-source flooding disaster and developing simulation framework in Delta

    Science.gov (United States)

    Liu, Y.; Cui, X.; Zhang, W.

    2016-12-01

    Most Delta regions of the world are densely populated and with advanced economies. However, due to impact of the multi-source flooding (upstream flood, rainstorm waterlogging, storm surge flood), the Delta regions is very vulnerable. The academic circles attach great importance to the multi-source flooding disaster in these areas. The Pearl River Delta urban agglomeration in south China is selected as the research area. Based on analysis of natural and environmental characteristics data of the Delta urban agglomeration(remote sensing data, land use data, topographic map, etc.), hydrological monitoring data, research of the uneven distribution and process of regional rainfall, the relationship between the underlying surface and the parameters of runoff, effect of flood storage pattern, we use an automatic or semi-automatic method for dividing spatial units to reflect the runoff characteristics in urban agglomeration, and develop an Multi-model Ensemble System in changing environment, including urban hydrologic model, parallel computational 1D&2D hydrodynamic model, storm surge forecast model and other professional models, the system will have the abilities like real-time setting a variety of boundary conditions, fast and real-time calculation, dynamic presentation of results, powerful statistical analysis function. The model could be optimized and improved by a variety of verification methods. This work was supported by the National Natural Science Foundation of China (41471427); Special Basic Research Key Fund for Central Public Scientific Research Institutes.

  15. Peroxisome proliferator-activated receptor delta activation leads to increased transintestinal cholesterol efflux

    NARCIS (Netherlands)

    Vrins, Carlos L. J.; van der Velde, Astrid E.; van den Oever, Karin; Levels, Johannes H. M.; Huet, Stephane; Elferink, Ronald P. J. Oude; Kuipers, Folkert; Groen, Albert K.

    2009-01-01

    Peroxisome proliferator-activated receptor delta (PPAR delta) is involved in regulation of energy homeostasis. Activation of PPAR delta markedly increases fecal neutral sterol secretion, the last step in reverse cholesterol transport. This phenomenon can neither be explained by increased

  16. Measurement of delta-rays in ATLAS silicon sensors

    CERN Document Server

    The ATLAS collaboration

    2013-01-01

    In the inner detector of the ATLAS experiment at the LHC, $\\delta$-rays originating from particle interactions in the silicon sensors may cause additional hit channels. A method for identifying silicon hit clusters that are enlarged due to the emission of a $\\delta$-ray is presented. Using pp collision data the expectation is confirmed that the $\\delta$-ray production rate depends linearly on the path length of the particle in silicon, independently of layer radius and detector technology. The range of the $\\delta$-rays, which is a property of the material and should not depend on anything else, is indeed found to be constant as a function of detector layer, path length in silicon and momentum of the particle traversing the silicon. As a by-product of this analysis a method is proposed that could correct for the effect of these $\\delta$-rays, and this could be used to improve track reconstruction.

  17. (p,. pi. /sup -/) reaction and. delta. /sup + +/ components of nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Kisslinger, L S; Miller, G A [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

    1975-12-08

    The use of the (p,..pi../sup -/) reaction as a probe to determine ..delta../sup + +/(1232) components of nuclear wave functions is examined within the framework of a model which treats baryon resonances on the same footing as nucleons. Nuclear structure properties which affect the ..delta..-probability are discussed. Estimates of cross sections, at several energies, are made for the ..delta../sup + +/ transfer contribution as well as for the competing processes: proton charge exchange (p,n) followed by an (n,..gamma../sup -/) reaction; emission of a ..pi../sup 0/ followed by pion charge exchange (..pi../sup -/,..pi../sup 0/). Even with ..delta..-probabilities as small as 0.0001 the ..delta..-transfer process can compete with ordinary background charge-exchange reactions.

  18. KAJIAN PENCEMARAN LINGKUNGAN DI TAMBAK UDANG DELTA MAHAKAM

    Directory of Open Access Journals (Sweden)

    Salahuddin, Chafid Fandeli, dan Eko Sugiharto

    2012-06-01

    Full Text Available well-managed, it will contribute to the improvement of both regional and national economy. However, MahakamRiver gets liquid waste pollution that has significant impact on water quality and results in conflicts betweenthe local societies, especially the shrimp pond farmers and the fishermen and the oil and gas industrial company.This research uses descriptive-comparative analysis with ANOVA test to compare samples (water, soil/sediment,shrimp, and mangrove of the shrimp fishpond (many mangrove, moderate mangrove, few mangrove, and withoutany mangrove. The pollution load which is analyzed includes: cadmium content (Cd, lead (Pb, oil and grease (O& G, mercury (Hg, and arsenic (As. The significance level is 90% with error of 5% (0.05.The water of Mahakam Delta is still in the normality limit as seen from the maximum pollution load in the Decreeof the Minister of Living Environment No. 51 of 2004 on Ocean Water Standard seen from chemical, physical,and biological parameters. The presence of mangrove contributes positive value to the balance of the quality of thewaters and to the neutralizing of heavy metals contents of Mahakam Delta as shown in the average difference inthe Pb, Cd, O & G, As and Hg of the samples of water, soils/sediment, shrimp and mangrove which are drawnfrom the of shrimp pond with many mangrove, moderate mangrove, few mangrove and without any mangrove,which is significantly different (p < 0.05. Shrimp pond with many mangrove has less average levels of Pb, Cd, M& L, As and Hg compared with the pond with less and without mangrove. The shrimp pond with many mangrovescontributes significantly and positively to the prevention of the pollution of Pb, Cd, O and G, As and Hg at low level

  19. Spectral factorization using the delta operator

    DEFF Research Database (Denmark)

    Rostgaard, Morten; Poulsen, Niels Kjølstad; Ravn, Ole

    1994-01-01

    In recent years many papers have been published abouth the gamma-operator, mostly caused by the better numerical properties and the rapprochement between continuous and discrete time. A major problem within the LQG-design of a delta-based input-output relation has been how to spectral-factorize...... solution to the spectral factorization problem. The key idea is to use the gamma-operator resembled by its behavior to the differential operator....... in an efficient way. The discrete-time method of Kuccera will not be applied since numerical word-length characteristics will be poor for fast sampling rates. In this paper a new approach is considered. A new gamma-operator (Tustin operator) is introduced, in order to make an iterative and numerical stable...

  20. Head orientation prediction: delta quaternions versus quaternions.

    Science.gov (United States)

    Himberg, Henry; Motai, Yuichi

    2009-12-01

    Display lag in simulation environments with helmet-mounted displays causes a loss of immersion that degrades the value of virtual/augmented reality training simulators. Simulators use predictive tracking to compensate for display lag, preparing display updates based on the anticipated head motion. This paper proposes a new method for predicting head orientation using a delta quaternion (DQ)-based extended Kalman filter (EKF) and compares the performance to a quaternion EKF. The proposed framework operates on the change in quaternion between consecutive data frames (the DQ), which avoids the heavy computational burden of the quaternion motion equation. Head velocity is estimated from the DQ by an EKF and then used to predict future head orientation. We have tested the new framework with captured head motion data and compared it with the computationally expensive quaternion filter. Experimental results indicate that the proposed DQ method provides the accuracy of the quaternion method without the heavy computational burden.

  1. A Place to Call Home: A Synthesis of Delta Smelt Habitat in the Upper San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Ted Sommer

    2013-06-01

    Full Text Available We used a combination of published literature and field survey data to synthesize the available information about habitat use by delta smelt Hypomesus transpacificus, a declining native species in the San Francisco Estuary. Delta smelt habitat ranges from San Pablo and Suisun bays to their freshwater tributaries, including the Sacramento and San Joaquin rivers. In recent years, substantial numbers of delta smelt have colonized habitat in Liberty Island, a north Delta area that flooded in 1997. The species has a more upstream distribution during spawning as opposed to juvenile rearing periods. Post-larvae and juveniles tend to have a more downstream distribution during wetter years. Delta smelt are most common in low-salinity habitat (<6 psu with high turbidities (>12 NTU and moderate temperatures (7 °C to 25 °C. They do not appear to have strong substrate preferences, but sandy shoals are important for spawning in other osmerids. The evidence to date suggests that they generally require at least some tidal flow in their habitats. Delta smelt also occur in a wide range of channel sizes, although they seem to be rarer in small channels (<15 m wide. Nonetheless, there is some evidence that open water adjacent to habitats with long water-residence times (e.g. tidal marsh, shoal, low-order channels may be favorable. Other desirable features of delta smelt habitat include high calanoid copepod densities and low levels of submerged aquatic vegetation (SAV and the toxic algae Microcystis. Although enough is known to plan for large-scale pilot habitat projects, these efforts are vulnerable to several factors, most notably climate change, which will change salinity regimes and increase the occurrence of lethal temperatures. We recommend restoration of multiple geographical regions and habitats coupled with extensive monitoring and adaptive management. An overall emphasis on ecosystem processes rather than specific habitat features is also likely to be

  2. Dependence of {delta}E effect on internal stresses in nickel: Experimental results by laser interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Chicharro, J.M. [Dept. de Mecanica Aplicada e Ingenieria de Proyectos, E.T.S.I. Industriales, Universidad de Castilla-La Mancha, Avd. Camilo Jose Cela s/n, 13071 Ciudad Real (Spain)]. E-mail: josemanuel.chicharro@uclm.es; Bayon, A. [Dept. de Fisica Aplicada a los Recursos Naturales, E.T.S.I. Minas, Universidad Politecnica de Madrid, c/Rios Rosas, 21, 28003 Madrid (Spain); Salazar, F. [Dept. de Fisica Aplicada a los Recursos Naturales, E.T.S.I. Minas, Universidad Politecnica de Madrid, c/Rios Rosas, 21, 28003 Madrid (Spain)

    2006-02-15

    The speckle heterodyne interferometry is applied to the study of the dependence of Young's modulus on both the magnetic field and the internal stresses in a soft ferromagnetic material. Young's modulus is determined from the first natural longitudinal frequency of a slender magnetic rod positioned within a solenoid. Vibration of the sample is detected by an optical heterodyne system with a wide bandwidth. The samples are heated to above the Curie point and then cooled at several rates in order to induce different internal stresses. The study refers to nickel rods 10mm in diameter and 110mm in length. The grain sizes of the samples are also determined and related to changes in {delta}E.

  3. Multimode delta-E effect magnetic field sensors with adapted electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Zabel, Sebastian; Fichtner, Simon; Kirchhof, Christine; Quandt, Eckhard; Faupel, Franz, E-mail: ff@tf.uni-kiel.de [Faculty of Engineering, Institute for Materials Science, Kiel University, Kaiserstraße 2, 24143 Kiel (Germany); Reermann, Jens; Schmidt, Gerhard [Faculty of Engineering, Institute for Electrical Engineering, Kiel University, Kaiserstraße 2, 24143 Kiel (Germany); Wagner, Bernhard [Fraunhofer Institute for Silicon Technology ISIT, Fraunhoferstraße 1, 25524 Itzehoe (Germany)

    2016-05-30

    We present an analytical and experimental study on low-noise piezoelectric thin film resonators that utilize the delta-E effect of a magnetostrictive layer to measure magnetic fields at low frequencies. Calculations from a physical model of the electromechanical resonator enable electrode designs to efficiently operate in the first and second transversal bending modes. As predicted by our calculations, the adapted electrode design improves the sensitivity by a factor of 6 and reduces the dynamic range of the sensor output by 16 dB, which significantly eases the requirements on readout electronics. Magnetic measurements show a bandwidth of 100 Hz at a noise level of about 100 pTHz{sup −0.5}.

  4. The Atchafalaya River Delta. Report 7. Analytical Analysis of the Development of the Atchafalaya River Delta.

    Science.gov (United States)

    1985-09-01

    responsible for the abrupt increases in subaerial delta growth. 64. Through using satellite imagery, color infrared photog- raphy, and digital current...w RO CF = HO/A/BO/(2.-D) w (HH wo (2.-D) - 1.) + O.5/AA X2 = BO m 2.m AA a HHow(D-1.) o CF AREA = (2.wAAwB~ ww2 ) im (CKI*(1. + AmBO/HOwRO) ww2 &+ CK2 a

  5. Landscape scale controls on the vascular plant component of dissolved organic carbon across a freshwater delta

    Science.gov (United States)

    Eckard, Robert S.; Hernes, Peter J.; Bergamaschi, Brian A.; Stepanauskas, Ramunas; Kendall, Carol

    2007-01-01

    Lignin phenol concentrations and compositions were determined on dissolved organic carbon (DOC) extracts (XAD resins) within the Sacramento-San Joaquin River Delta (the Delta), the tidal freshwater portion of the San Francisco Bay Estuary, located in central California, USA. Fourteen stations were sampled, including the following habitats and land-use types: wetland, riverine, channelized waterway, open water, and island drains. Stations were sampled approximately seasonally from December, 1999 through May, 2001. DOC concentrations ranged from 1.3 mg L-1 within the Sacramento River to 39.9 mg L-1 at the outfall from an island drain (median 3.0 mg L-1), while lignin concentrations ranged from 3.0 μL-1 within the Sacramento River to 111 μL-1 at the outfall from an island drain (median 11.6 μL-1). Both DOC and lignin concentrations varied significantly among habitat/land-use types and among sampling stations. Carbon-normalized lignin yields ranged from 0.07 mg (100 mg OC)-1 at an island drain to 0.84 mg (100 mg OC)-1 for a wetland (median 0.36 mg (100 mg OC)-1), and also varied significantly among habitat/land-use types. A simple mass balance model indicated that the Delta acted as a source of lignin during late autumn through spring (10-83% increase) and a sink for lignin during summer and autumn (13-39% decrease). Endmember mixing models using S:V and C:V signatures of landscape scale features indicated strong temporal variation in sources of DOC export from the Delta, with riverine source signatures responsible for 50% of DOC in summer and winter, wetland signatures responsible for 40% of DOC in summer, winter, and late autumn, and island drains responsible for 40% of exported DOC in late autumn. A significant negative correlation was observed between carbon-normalized lignin yields and DOC bioavailability in two of the 14 sampling stations. This study is, to our knowledge, the first to describe organic vascular plant DOC sources at the level of localized

  6. Super-delta: a new differential gene expression analysis procedure with robust data normalization.

    Science.gov (United States)

    Liu, Yuhang; Zhang, Jinfeng; Qiu, Xing

    2017-12-21

    Normalization is an important data preparation step in gene expression analyses, designed to remove various systematic noise. Sample variance is greatly reduced after normalization, hence the power of subsequent statistical analyses is likely to increase. On the other hand, variance reduction is made possible by borrowing information across all genes, including differentially expressed genes (DEGs) and outliers, which will inevitably introduce some bias. This bias typically inflates type I error; and can reduce statistical power in certain situations. In this study we propose a new differential expression analysis pipeline, dubbed as super-delta, that consists of a multivariate extension of the global normalization and a modified t-test. A robust procedure is designed to minimize the bias introduced by DEGs in the normalization step. The modified t-test is derived based on asymptotic theory for hypothesis testing that suitably pairs with the proposed robust normalization. We first compared super-delta with four commonly used normalization methods: global, median-IQR, quantile, and cyclic loess normalization in simulation studies. Super-delta was shown to have better statistical power with tighter control of type I error rate than its competitors. In many cases, the performance of super-delta is close to that of an oracle test in which datasets without technical noise were used. We then applied all methods to a collection of gene expression datasets on breast cancer patients who received neoadjuvant chemotherapy. While there is a substantial overlap of the DEGs identified by all of them, super-delta were able to identify comparatively more DEGs than its competitors. Downstream gene set enrichment analysis confirmed that all these methods selected largely consistent pathways. Detailed investigations on the relatively small differences showed that pathways identified by super-delta have better connections to breast cancer than other methods. As a new pipeline, super-delta

  7. Food and Nutrition Security Trends, Determinants and Challenges in the Ganges-Brahmaputra Delta

    Science.gov (United States)

    Nilsen, K.; van Soesbergen, A.; Matthews, Z.; Burgess, N.

    2016-12-01

    In the last 20 years many developing countries have made considerable progress towards improving food security and nutrition. However, progress across countries and dimensions of food security have been uneven. While challenges to food security in the context of environmental and climate changes have been studied widely, limited evidence exists for their implications for food and nutrition security in tropical deltaic regions. Delta areas are particularly vulnerable to food insecurity and malnutrition due the specific environmental, climatic and human development factors affecting agricultural production and fisheries. These include coastal flooding and storm surges, deforestation, changes to river flow patterns and water tables, increased soil salinity and water quality degradation. Due to the large number of people living in deltaic regions and their importance in regional food production, there is a pressing need for a better understanding on how environmental factors affect food security and malnutrition. This study explores the potential impacts and challenges posed by environmental and climate change on food and nutrition security in the Ganges-Brahmaputra delta. This delta is one of the world's largest delta's draining land from Bangladesh, Bhutan, China, India and Nepal. The delta makes up around two thirds of the country of Bangladesh, a country facing high levels of child undernutrition, child mortality and a high number of people living under extreme poverty. By combining spatially explicit data from the 2007 and 2011 Demographic and Health Surveys (DHS) for Bangladesh with satellite remote sensing data (Normalised Difference Vegetation Index) for relevant growing seasons of rice, the strength of association between this climate related environmental variable and indicators of child nutrition (wasting and stunting) in the delta were evaluated. Our results show that NDVI for the growing season of rice can be used to determine trends in rice production

  8. Natural disturbance shapes benthic intertidal macroinvertebrate communities of high latitude river deltas

    Science.gov (United States)

    Churchwell, Roy T.; Kendall, Steve J.; Blanchard, Amy L.; Dunton, Kenneth H.; Powell, Abby N.

    2016-01-01

    Unlike lower latitude coastlines, the estuarine nearshore zones of the Alaskan Beaufort Sea are icebound and frozen up to 9 months annually. This annual freezing event represents a dramatic physical disturbance to fauna living within intertidal sediments. The main objectives of this study were to describe the benthic communities of Beaufort Sea deltas, including temporal changes and trophic structure. Understanding benthic invertebrate communities provided a baseline for concurrent research on shorebird foraging ecology at these sites. We found that despite continuous year-to-year episodes of annual freezing, these estuarine deltas are populated by a range of invertebrates that represent both marine and freshwater assemblages. Freshwater organisms like Diptera and Oligochaeta not only survive this extreme event, but a marine invasion of infaunal organisms such as Amphipoda and Polychaeta rapidly recolonizes the delta mudflats following ice ablation. These delta sediments of sand, silt, and clay are fine in structure compared to sediments of other Beaufort Sea coastal intertidal habitats. The relatively depauperate invertebrate community that ultimately develops is composed of marine and freshwater benthic invertebrates. The composition of the infauna also reflects two strategies that make life on Beaufort Sea deltas possible: a migration of marine organisms from deeper lagoons to the intertidal and freshwater biota that survive the 9-month ice-covered period in frozen sediments. Stable isotopic analyses reveal that both infaunal assemblages assimilate marine and terrestrial sources of organic carbon. These results provide some of the first quantitative information on the infaunal food resources of shallow arctic estuarine systems and the long-term persistence of these invertebrate assemblages. Our data help explain the presence of large numbers of shorebirds in these habitats during the brief summer open-water period and their trophic importance to migrating

  9. Vulnerability of the Nile Delta coastal areas to inundation by sea level rise.

    Science.gov (United States)

    Hassaan, M A; Abdrabo, M A

    2013-08-01

    Sea level changes are typically caused by several natural phenomena, including ocean thermal expansion, glacial melt from Greenland and Antarctica. Global average sea level is expected to rise, through the twenty-first century, according to the IPCC projections by between 0.18 and 0.59 cm. Such a rise in sea level will significantly impact coastal area of the Nile Delta, consisting generally of lowland and is densely populated areas and accommodates significant proportion of Egypt's economic activities and built-up areas. The Nile Delta has been examined in several previous studies, which worked under various hypothetical sea level rise (SLR) scenarios and provided different estimates of areas susceptible to inundation due to SLR. The paper intends, in this respect, to identify areas, as well as land use/land cover, susceptible to inundation by SLR based upon most recent scenarios of SLR, by the year 2100 using GIS. The results indicate that about 22.49, 42.18, and 49.22 % of the total area of coastal governorates of the Nile Delta would be susceptible to inundation under different scenarios of SLR. Also, it was found that 15.56 % of the total areas of the Nile Delta that would be vulnerable to inundation due to land subsidence only, even in the absence of any rise in sea level. Moreover, it was found that a considerable proportion of these areas (ranging between 32.32 and 53.66 %) are currently either wetland or undeveloped areas. Furthermore, natural and/or man-made structures, such as the banks of the International Coastal Highway, were found to provide unintended protection to some of these areas. This suggests that the inundation impact of SLR on the Nile Delta is less than previously reported.

  10. Measuring and predicting Delta(vap)H298 values of ionic liquids.

    Science.gov (United States)

    Deyko, Alexey; Lovelock, Kevin R J; Corfield, Jo-Anne; Taylor, Alasdair W; Gooden, Peter N; Villar-Garcia, Ignacio J; Licence, Peter; Jones, Robert G; Krasovskiy, Vladimir G; Chernikova, Elena A; Kustov, Leonid M

    2009-10-14

    We report the enthalpies of vaporisation (measured using temperature programmed desorption by mass spectrometry) of twelve ionic liquids (ILs), covering four imidazolium, [C(m)C(n)Im]+, five pyrrolidinium, [C(n)C(m)Pyrr]+, two pyridinium, [C(n)Py]+, and a dication, [C3(C1Im)2]2+ based IL. These cations were paired with a range of anions: [BF4]-, [FeCl4]-, [N(CN)2]-, [PF3(C2F5)3]- ([FAP]-), [(CF3SO2)2N]- ([Tf2N]-) and [SCN]-. Using these results, plus those for a further eight imidazolium based ILs published earlier (which include the anions [CF3SO3]- ([TfO]-), [PF6]- and [EtSO4]-), we show that the enthalpies of vaporisation can be decomposed into three components. The first component is the Coulombic interaction between the ions, DeltaU(Cou,R), which is a function of the IL molar volume, V(m), and a parameter R(r) which quantifies the relative change in anion-cation distance on evaporation from the liquid phase to the ion pair in the gas phase. The second and third components are the van der Waals contributions from the anion, DeltaH(vdw,A), and the cation, DeltaH(vdw,C). We derive a universal value for R(r), and individual values of DeltaH(vdw,A) and DeltaH(vdw,C) for each of the anions and cations considered in this study. Given the molar volume, it is possible to estimate the enthalpies of vaporisation of ILs composed of any combination of the ions considered here; values for fourteen ILs which have not yet been studied experimentally are given.

  11. Comparing and contrasting observed adaptations in three deltas: the Ganges-Meghna-Brahmaputra, Mahanadi and Volta

    Science.gov (United States)

    Nicholls, R. J.; Suckall, N.; Mensah, A.; Mondal, S.; Dey, S.; Hazra, S.

    2015-12-01

    In low and middle-income countries, many deltaic communities directly depend on the natural environment for income and well-being. Current environmental concerns that threaten deltaic communities, such as increasing salinity, sedimentation, erosion and subsidence are likely to be exacerbated by climate change and variability, for example sea-level rise, increased storminess and rising temperatures. Such changes, along with other social and environmental stressors, mean that communities must adapt. This paper outlines findings of a systematic review of the peer-reviewed and grey literature that examines observed adaptations in three deltas of differing sizes in various geographical contexts: the Ganges-Meghna-Brahmaputra in India and Bangladesh, the Mahanadi in India, and the Volta in Ghana. It compares and contrasts various elements of observed adaptations, including who is driving the adaptation, the beneficiaries, barriers to participation and evidence for maladaptation. The predominant drivers of adaptation vary from government (at state level in India and national level in Bangladesh) and NGOs (in Ghana). Autonomous adaptations are not widely reported in the literature from any of the deltas. In all three deltas there is a focus on supporting adaptation in farming rather than fishing; despite the fact that fisheries contribute to local food security as well as national economies. Lack of access to financial, natural, physical and human capital are common barriers to adaptation in all three deltas. Additionally the Indian literature in particular highlights the lack of coordination between different government departments, coupled with an excessively top-down (state-driven) approach to adaptation. Maladaptation is most commonly reported in the literature from Bangladesh, for example, loss of employment of inland fishermen in embanked areas. The paper concludes by highlighting some of the implications of these findings for adaptation policy in deltas.

  12. Breed distribution of the ABCB1-1Delta (multidrug sensitivity) polymorphism among dogs undergoing ABCB1 genotyping.

    Science.gov (United States)

    Mealey, Katrina L; Meurs, Kathryn M

    2008-09-15

    To evaluate the breed distribution of the ABCB1-1Delta polymorphism in a large number of dogs in North America, including dogs of several herding breeds in which this polymorphism has been detected and other breeds in which this polymorphism has not yet been identified. Cross-sectional study. 5,368 dogs from which buccal swab samples were collected for purposes of ABCB1 genotyping. From May 1, 2004, to September 30, 2007, DNA specimens derived from buccal swab samples collected from 5,368 dogs underwent ABCB1 genotyping. These data were reviewed, and results for each dog were recorded in a spreadsheet, along with the dog's breed. The genotypes for each breed were tallied by use of a sorting function. The ABCB1-1Delta allele was identified in 9 breeds of dogs and in many mixed-breed dogs. Breeds that had the ABCB1-1Delta allele included Collie, Longhaired Whippet, Australian Shepherd (standard and miniature), Shetland Sheepdog, Old English Sheepdog, Border Collie, Silken Windhound, and German Shepherd Dog (a breed in which this mutation had not been detected previously). The ABCB1-1Delta polymorphism is associated with increased susceptibility to many adverse drug reactions and with suppression of the hypothalamic-pituitary-adrenal axis and is present in many herding breeds of dog. Veterinarians should be familiar with the breeds that have the ABCB1-1Delta polymorphism to make appropriate pharmacologic choices for these patients.

  13. Deprivation and Resistance: Environmental Crisis, Political Action, and Conflict Resolution in the Niger Delta since the 1980s

    Directory of Open Access Journals (Sweden)

    David Aworawo

    2013-05-01

    Full Text Available The interlocking relationship between environmental degradation, poverty,and violent conflict has been a prominent theme contained within the literature on sustainable development and conflict resolution since the midtwentieth century. While some analysts have argued that violence has not been limited to the poor and deprived, many have concluded from various studies that the devastation of the environment, poverty, and conflict are inextricably intertwined. This article examines this theme by analyzing the pattern of violence and nature of conflict resolution in the oil-producing enclave of the Niger Delta in the past three decades. A report of the United Nations Environment Programme on parts of the Niger Delta published in August 2011 reveals that the area is one of the most intensely polluted in the world. The report confirms the conclusion of several other earlier reports on the Niger Delta, which state that activities relating to the exploitation of oil and gas have led to intense environmental pollution and extreme poverty and that those conditions have spawned violence. The article is exploratory and analytical. It draws from diverse sources, including government records and reports of intergovernmental and non-governmental organizations as well as oral information gathered by the author from fieldwork conducted across the Niger Delta between 2007 and 2012, to explore the nature of the Niger Delta crisis from the 1980s until the present. The article argues that environmental degradation is central to the Niger Delta crisis, as it has hampered rural economic activities and posed a threat to human security. The article concludes that the effective tackling of the environmental crisis in the Niger Delta would surely reduce poverty and violence in the area.

  14. Formation Conditions and Sedimentary Characteristics of a Triassic Shallow Water Braided Delta in the Yanchang Formation, Southwest Ordos Basin, China.

    Directory of Open Access Journals (Sweden)

    Ziliang Liu

    Full Text Available A large, shallow braided river delta sedimentary system developed in the Yanchang Formation during the Triassic in the southwest of the Ordos basin. In this braided delta system, abundant oil and gas resources have been observed, and the area is a hotspot for oil and gas resource exploration. Through extensive field work on outcrops and cores and analyses of geophysical data, it was determined that developments in the Late Triassic produced favorable geological conditions for the development of shallow water braided river deltas. Such conditions included a large basin, flat terrain, and wide and shallow water areas; wet and dry cyclical climate changes; ancient water turbulence; dramatic depth cycle changes; ancient uplift development; strong weathering of parent rock; and abundant supply. The shallow water braided river delta showed grain sediment granularity, plastic debris, and sediment with mature composition and structure that reflected the strong hydrodynamic environment of large tabular cross-bedding, wedge cross-bedding, and multiple positive rhythms superimposed to form a thick sand body layer. The branch river bifurcation developed underwater, and the thickness of the sand body increased further, indicating that the slope was slow and located in shallow water. The seismic responses of the braided river delta reflected strong shallow water performance, indicated by a progradation seismic reflection phase axis that was relatively flat; in addition, the seismic reflection amplitude was strong and continuous with a low angle and extended over considerable distances (up to 50 km. The sedimentary center was close to the provenance, the width of the river was large, and a shallow sedimentary structure and a sedimentary rhythm were developed. The development of the delta was primarily controlled by tectonic activity and changes in the lake level; as a result, the river delta sedimentary system eventually presented a "small plain, big front

  15. Formation Conditions and Sedimentary Characteristics of a Triassic Shallow Water Braided Delta in the Yanchang Formation, Southwest Ordos Basin, China.

    Science.gov (United States)

    Liu, Ziliang; Shen, Fang; Zhu, Xiaomin; Li, Fengjie; Tan, Mengqi

    2015-01-01

    A large, shallow braided river delta sedimentary system developed in the Yanchang Formation during the Triassic in the southwest of the Ordos basin. In this braided delta system, abundant oil and gas resources have been observed, and the area is a hotspot for oil and gas resource exploration. Through extensive field work on outcrops and cores and analyses of geophysical data, it was determined that developments in the Late Triassic produced favorable geological conditions for the development of shallow water braided river deltas. Such conditions included a large basin, flat terrain, and wide and shallow water areas; wet and dry cyclical climate changes; ancient water turbulence; dramatic depth cycle changes; ancient uplift development; strong weathering of parent rock; and abundant supply. The shallow water braided river delta showed grain sediment granularity, plastic debris, and sediment with mature composition and structure that reflected the strong hydrodynamic environment of large tabular cross-bedding, wedge cross-bedding, and multiple positive rhythms superimposed to form a thick sand body layer. The branch river bifurcation developed underwater, and the thickness of the sand body increased further, indicating that the slope was slow and located in shallow water. The seismic responses of the braided river delta reflected strong shallow water performance, indicated by a progradation seismic reflection phase axis that was relatively flat; in addition, the seismic reflection amplitude was strong and continuous with a low angle and extended over considerable distances (up to 50 km). The sedimentary center was close to the provenance, the width of the river was large, and a shallow sedimentary structure and a sedimentary rhythm were developed. The development of the delta was primarily controlled by tectonic activity and changes in the lake level; as a result, the river delta sedimentary system eventually presented a "small plain, big front" character.

  16. Navier-Stokes prediction of a delta wing in roll with vortex breakdown

    Science.gov (United States)

    Chaderjian, Neal M.; Schiff, Lewis B.

    1993-01-01

    The three-dimensional, Reynolds-averaged, Navier-Stokes (RANS) equations are used to numerically simulate vortical flow about a 65 degree sweep delta wing. Subsonic turbulent flow computations are presented for this delta wing at 30 degrees angle of attack and static roll angles up to 42 degrees. This work is part of an on going effort to validate the RANS approach for predicting high-incidence vortical flows, with the eventual application to wing rock. The flow is unsteady and includes spiral-type vortex breakdown. The breakdown positions, mean surface pressures, rolling moments, normal forces, and streamwise center-of-pressure locations compare reasonably well with experiment. In some cases, the primary vortex suction peaks are significantly underpredicted due to grid coarseness. Nevertheless, the computations are able to predict the same nonlinear variation of rolling moment with roll angle that appeared in the experiment. This nonlinearity includes regions of local static roll instability, which is attributed to vortex breakdown.

  17. Primary production in the Delta: Then and now

    Science.gov (United States)

    Cloern, James E.; Robinson, April; Richey, Amy; Grenier, Letitia; Grossinger, Robin; Boyer, Katharyn E.; Burau, Jon; Canuel, Elizabeth A.; DeGeorge, John F.; Drexler, Judith Z.; Enright, Chris; Howe, Emily R.; Kneib, Ronald; Mueller-Solger, Anke; Naiman, Robert J.; Pinckney, James L.; Safran, Samuel M.; Schoellhamer, David H.; Simenstad, Charles A.

    2016-01-01

    To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850). Here we describe an approach for using these metrics of land use change to: (1) produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2) convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3) use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

  18. Primary Production in the Delta: Then and Now

    Directory of Open Access Journals (Sweden)

    James E. Cloern

    2016-10-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2016v14iss3art1To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850. Here we describe an approach for using these metrics of land use change to: (1 produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2 convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3 use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

  19. LIVER TRANSPLANTATION IN HEPATITIS DELTA: SOUTH AMERICA EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Daniel Souza LIMA

    Full Text Available ABSTRACT BACKGROUND: The Amazon region is one of the main endemic areas of hepatitis delta in the world and the only one related to the presence of genotype 3 of the delta virus. OBJECTIVE: To analyze the profile, mortality and survival of cirrhotic patients submitted to liver transplantation for chronic hepatitis delta virus and compare with those transplanted by hepatitis B virus monoinfection. METHODS: Retrospective, observational and descriptive study. From May 2002 to December 2011, 629 liver transplants were performed at the Walter Cantídio University Hospital, of which 29 patients were transplanted due to cirrhosis caused by chronic delta virus infection and 40 by hepatitis B chronic monoinfection. The variables analyzed were: age, sex, MELD score, Child-Pugh score, upper gastrointestinal bleeding and hepatocellular carcinoma occurrence before the transplantation, perioperative platelet count, mortality and survival. RESULTS: The Delta Group was younger and all came from the Brazilian Amazon Region. Group B presented a higher proportion of male patients (92.5% compared to Group D (58.6%. The occurrence of upper gastrointestinal bleeding before transplantation, MELD score, and Child-Pugh score did not show statistical differences between groups. The occurrence of hepatocellular carcinoma and mortality were higher in the hepatitis B Group. The survival in 4 years was 95% in the Delta Group and 75% in the B Group, with a statistically significant difference (P=0.034. Patients with hepatitis delta presented more evident thrombocytopenia in the pre-transplantation and in the immediate postoperative period. CONCLUSION: The hepatitis by delta virus patients who underwent liver transplantation were predominantly male, coming from the Brazilian Amazon region and with similar liver function to the hepatitis B virus patients. They had a lower incidence of hepatocellular carcinoma, more marked perioperative thrombocytopenia levels and frequent

  20. Delta Evolution at Røde Elv, Disko Island, Greenland

    Science.gov (United States)

    Kroon, A.; Arngrimson, J.; Bendixen, M.; Sigsgaard, C.

    2017-12-01

    Ice, snow and freezing temperatures have a large impact on coastal morphodynamics in Arctic polar environments. A recent warming of the Arctic climate induces many changes along the arctic shorelines. Sea-levels are rising due to thermal expansion and due to an increased fresh water flux from the glaciers and land ice masses. At the same time, the ice coverage of the coastal waters reduces and the open water periods in summer extend. There is a strong seasonal variation with open waters and active rivers in summer and ice-covered coastal waters and inactive rivers in winter. Coastal processes by waves and tides are thus limited to the summer and early fall. Besides, there is also a strong daily variation in fluvial discharges due to the daily variations in glacier melt with maximum melt in the afternoon and minimum values at night. At the same time, the actual flux of the river to the coastal bay is influenced by the tidal phase. Low tides will enhance the transport to the delta front, while high tides will create stagnant waters over the delta plain. The delta of the Røde Elv is located in southwestern Disko Island in west Greenland. It has a relatively small (ca. 101 km2) and partly glaciated drainage basin (ca. 20%) and its sediments consist of a mixture of basaltic sands and gravels. The Røde Elv delta is located at the end of a pro-glacial and fluvial valley at about 20 km from the glacier. The shores of the delta are reworked by waves, predominantly from southwestern, southern (largest fetch, over 50 km), and southeastern directions. The environment has a micro- to meso- tidal range with a spring tidal range of 2.7 m. The morphologic changes on the delta over the last decades clearly showed a seaward extension of the delta and a periodic shift in the location of the main delta channel. In this presentation, we focus on quantification of water discharges and suspended sediment fluxes to the Røde Elv delta in western Greenland, and on the morphological

  1. Late quaternary evolution of the Orinoco Delta, Venezuela

    Science.gov (United States)

    Warne, A.G.; Guevara, E.H.; Aslan, A.

    2002-01-01

    The modern Orinoco Delta is the latest of a series of stacked deltas that have infilled the Eastern Venezuelan Basin (EVB) since the Oligocene. During the late Pleistocene sea-level lowstand (20,000 to 16,000 yrs BP), bedrock control points at the position of the present delta apex prevented the river channel from incising as deeply as many other major river systems. Shallow seismic data indicate that the late Pleistocene Orinoco incised into the present continental shelf, where it formed a braided-river complex that transported sediment to a series of shelf-edge deltas. As sea level rose from 16,000 to 9,500 yrs BP, the Orinoco shoreline shifted rapidly landward, causing shallow-marine waves and currents to form a widespread transgressive sand unit. Decelerating sea-level rise and a warmer, wetter climate during the early Holocene (9,500 to 6,000 yrs BP) induced delta development within the relatively quiet-water environment of the EVB embayment. Sea level approached its present stand in the middle Holocene (6,000 to 3,000 yrs BP), and the Orinoco coast prograded, broadening the delta plain and infilling the EVB embayment. Significant quantities of Amazon sediment began to be transported to the Orinoco coast by littoral currents. Continued progradation in the late Holocene caused the constriction at Boca de Serpientes to alter nearshore and shelf hydrodynamics and subdivide the submarine delta into two distinct areas: the Atlantic shelf and the Gulf of Paria. The increased influence of littoral currents along the coast promoted mudcape development. Because most of the water and sediment were transported across the delta plain through the Rio Grande distributary in the southern delta, much of the central and northwestern delta plain became sediment starved, promoting widespread accumulation of peat deposits. Human impacts on the delta are mostly associated with the Volca??n Dam on Can??o Manamo. However, human activities have had relatively little effect on the

  2. Is there a self-organization principle of river deltas?

    Science.gov (United States)

    Tejedor, Alejandro; Longjas, Anthony; Foufoula-Georgiou, Efi

    2017-04-01

    River deltas are known to possess a complex topological and flux-partitioning structure which has recently been quantified using spectral graph theory [Tejedor et al., 2015a,b]. By analysis of real and simulated deltas it has also been shown that there is promise in formalizing relationships between this topo-dynamic delta structure and the underlying delta forming processes [e.g., Tejedor et al., 2016]. The question we pose here is whether there exists a first order organizational principle behind the self-organization of river deltas and whether this principle can be unraveled from the co-evolving topo-dynamic structure encoded in the delta planform. To answer this question, we introduce a new metric, the nonlocal Entropy Rate (nER) that captures the information content of a delta network in terms of the degree of uncertainty in delivering fluxes from any point of the network to the shoreline. We hypothesize that if the "guiding principle" of undisturbed deltas is to efficiently and robustly build land by increasing the diversity of their flux pathways over the delta plane, then they would exhibit maximum nonlocal Entropy Rate at states at which geometry and flux dynamics are at equilibrium. At the same time, their nER would be non-optimal at transient states, such as before and after major avulsions during which topology and dynamics adjust to each other to reach a new equilibrium state. We will present our results for field and simulated deltas, which confirm this hypothesis and open up new ways of thinking about self-organization, complexity and robustness in river deltas. One particular connection of interest might have important implications since entropy rate and resilience are related by the fluctuation theorem [Demetrius and Manke, 2005], and therefore our results suggest that deltas might in fact self-organize to maximize their resilience to structural and dynamic perturbations. References: Tejedor, A., A. Longjas, I. Zaliapin, and E. Foufoula

  3. Holocene evolution of the western Orinoco Delta, Venezuela

    Science.gov (United States)

    Aslan, A.; White, W.A.; Warne, A.G.; Guevara, E.H.

    2003-01-01

    The pristine nature of the Orinoco Delta of eastern Venezuela provides unique opportunities to study the geologic processes and environments of a major tropical delta. Remote-sensing images, shallow cores, and radiocarbon-dating of organic remains form the basis for describing deltaic environments and interpreting the Holocene history of the delta. The Orinoco Delta can be subdivided into two major sectors. The southeast sector is dominated by the Rio Grande-the principal distributary-and complex networks of anastomosing fluvial and tidal channels. The abundance of siliciclastic deposits suggests that fluvial processes such as over-bank flooding strongly influence this part of the delta. In contrast, the northwest sector is represented by few major distributaries, and overbank sedimentation is less widespread relative to the southeast sector. Peat is abundant and occurs in herbaceous and forested swamps that are individually up to 200 km2 in area. Northwest-directed littoral currents transport large volumes of suspended sediment and produce prominent mudcapes along the northwest coast. Mapping of surface sediments, vegetation, and major landforms identified four principal geomorphic systems within the western delta plain: (1) distributary channels, (2) interdistributary flood basins, (3) fluvial-marine transitional environments, and (4) marine-influenced coastal environments. Coring and radiocarbon dating of deltaic deposits show that the northern delta shoreline has prograded 20-30 km during the late Holocene sea-level highstand. Progradation has been accomplished by a combination of distributary avulsion and mudcape progradation. This style of deltaic progradation differs markedly from other deltas such as the Mississippi where distributary avulsion leads to coastal land loss, rather than shoreline progradation. The key difference is that the Orinoco Delta coastal zone receives prodigious amounts of sediment from northwest-moving littoral currents that transport

  4. Changes in sediment and organic carbon accumulation in a highly-disturbed ecosystem: The Sacramento-San Joaquin River Delta (California, USA)

    International Nuclear Information System (INIS)

    Canuel, Elizabeth A.; Lerberg, Elizabeth J.; Dickhut, Rebecca M.; Kuehl, Steven A.; Bianchi, Thomas S.; Wakeham, Stuart G.

    2009-01-01

    We used the Sacramento-San Joaquin River Delta CA (Delta, hereafter) as a model system for understanding how human activities influence the delivery of sediment and total organic carbon (TOC) over the past 50-60 years. Sediment cores were collected from sites within the Delta representing the Sacramento River (SAC), the San Joaquin River (SJR), and Franks Tract (FT), a flooded agricultural tract. A variety of anthropogenic tracers including 137 Cs, total DDE (ΣDDE) and brominated diphenyl ether (BDE) congeners were used to quantify sediment accumulation rates. This information was combined with total organic carbon (TOC) profiles to quantify rates of TOC accumulation. Across the three sites, sediment and TOC accumulation rates were four to eight-fold higher prior to 1972. Changes in sediment and TOC accumulation were coincident with completion of several large reservoirs and increased agriculture and urbanization in the Delta watershed. Radiocarbon content of TOC indicated that much of the carbon delivered to the Delta is 'pre-aged' reflecting processing in the Delta watershed or during transport to the sites rather than an input of predominantly contemporary carbon (e.g., 900-1400 years BP in surface sediments and 2200 yrs BP and 3610 yrs BP at the base of the SJR and FT cores, respectively). Together, these data suggest that human activities have altered the amount and age of TOC accumulating in the Delta since the 1940s.

  5. Recent Advances in Understanding Flow Dynamics and Transport of Water-Quality Constituents in the Sacramento–San Joaquin River Delta

    Directory of Open Access Journals (Sweden)

    David H. Schoellhamer

    2016-12-01

    Full Text Available doi: https://doi.org/10.15447/sfews.2016v14iss4art1This paper, part of the collection of research comprising the State of Bay–Delta Science 2016, describes advances during the past decade in understanding flow dynamics and how water-quality constituents move within California’s Sacramento–San Joaquin River Delta (Delta. Water-quality constituents include salinity, heat, oxygen, nutrients, contaminants, organic particles, and inorganic particles. These constituents are affected by water diversions and other human manipulations of flow, and they greatly affect the quantity and quality of benthic, pelagic, and intertidal habitat in the Delta. The Pacific Ocean, the Central Valley watershed, human intervention, the atmosphere, and internal biogeochemical processes are all drivers of flow and transport in the Delta. These drivers provide a conceptual framework for presenting recent findings. The tremendous expansion of acoustic and optical instruments deployed in the Delta over the past decade has greatly improved our understanding of how tidal variability affects flow and transport. Sediment is increasingly viewed as a diminishing resource needed to sustain pelagic habitat and tidal marsh, especially as sea level rises. Connections among the watershed, Delta, and San Francisco Bay that have been quantified recently highlight that a landscape view of this system is needed, rather than consideration of each region in isolation. We discuss interactions of multiple drivers and information gaps.

  6. Human Impacts On The Bengal Delta's Response To Rapid Climate And Sea-Level Changes: Who Threatens Whom? (Invited)

    Science.gov (United States)

    Goodbred, S. L.

    2009-12-01

    The densely populated country of Bangladesh is often cited as being severely threatened by predicted changes in climate and accelerated sea-level rise. Justification for this grave assessment is founded in part on the low-lying nation's frequent inundation by river floods and storm surges, which affect millions of people annually. Indeed, nearly 50% of the delta system lies natural environment it speaks more to a healthful future than decline. Here I present field-based observations of sediment dispersal in the modern Bengal delta, which demonstrate how the system may remain relatively stable over the next century. However, this potentially acceptable outcome becomes increasingly unlikely if human interferences are considered. For example, short-term strategies to mitigate flooding would likely involve artificial leveeing of the river and the diking of coastal lowlands, both of which would limit sedimentation and diminish relative elevation of the delta surface. Threats upstream of the delta also include river damming to address demands for hydroelectric power and water resources in India, with a resulting decline in sediment discharge to the coast. Ultimately, it may be the impacts of such direct human-modification to the Bengal delta and river systems that outpace - in time and severity - those resulting from climate and sea-level changes alone.

  7. A scenario framework to explore the future migration and adaptation in deltas: A multi-scale and participatory approach

    Science.gov (United States)

    Kebede, Abiy S.; Nicholls, Robert J.; Allan, Andrew; Arto, Inaki; Cazcarro, Ignacio; Fernandes, Jose A.; Hill, Chris T.; Hutton, Craig W.; Kay, Susan; Lawn, Jon; Lazar, Attila N.; Whitehead, Paul W.

    2017-04-01

    Coastal deltas are home for over 500 million people globally, and they have been identified as one of the most vulnerable coastal environments during the 21st century. They are susceptible to multiple climatic (e.g., sea-level rise, storm surges, change in temperature and precipitation) and socio-economic (e.g., human-induced subsidence, population and urbanisation changes, GDP growth) drivers of change. These drivers also operate at multiple scales, ranging from local to global and short- to long-term. This highlights the complex challenges deltas face in terms of both their long-term sustainability as well as the well-being of their residents and the health of ecosystems that support the livelihood of large (often very poor) population under uncertain changing conditions. A holistic understanding of these challenges and the potential impacts of future climate and socio-economic changes is central for devising robust adaptation policies. Scenario analysis has long been identified as a strategic management tool to explore future climate change and its impacts for supporting robust decision-making under uncertainty. This work presents the overall scenario framework, methodology, and processes adopted for the development of scenarios in the DECCMA* project. DECCMA is analysing the future of three deltas in South Asia and West Africa: (i) the Ganges-Brahmaputra-Meghna (GBM) delta (Bangladesh/India), (ii) the Mahanadi delta (India), and (iii) the Volta delta (Ghana). This includes comparisons between these three deltas. Hence, the scenario framework comprises a multi-scale hybrid approach, with six levels of scenario considerations: (i) global (climate change, e.g., sea-level rise, temperature change; and socio-economic assumptions, e.g., population and urbanisation changes, GDP growth); (ii) regional catchments (e.g., river flow modelling), (iii) regional seas (e.g., fisheries modelling), (iv) regional politics (e.g., transboundary disputes), (v) national (e.g., socio

  8. The DELTA 181 lithium thionyl chloride battery

    Science.gov (United States)

    Sullivan, Ralph M.; Brown, Lawrence E.; Leigh, A. P.

    In 1986, the Johns Hopkins University/Applied Physics Laboratory (JHU/APL) undertook the development of a sensor module for the DELTA 181 spacecraft, a low earth orbit (LEO) mission of less than two months duration. A large lithium thionyl chloride battery was developed as the spacecraft's primary power source, the first known such use for this technology. The exceptionally high energy density of the lithium thionyl chloride cell was the primary driver for its use, resulting in a completed battery with a specific energy density of 120 Wh/lb. Safety requirements became the primary driver shaping all aspects of the power system design and development due to concerns about the potential hazards of this relatively new, high-energy technology. However, the program was completed without incident. The spacecraft was launched on February 8, 1988, from Kennedy Space Center (KSC) with over 60,000 Wh of battery energy. It reentered on April 2, 1988, still operating after 55 days, providing a successful, practical, and visible demonstration of the use of this technology for spacecraft applications.

  9. Chiral model for nucleon and delta

    International Nuclear Information System (INIS)

    Birse, M.C.; Banerjee, M.K.

    1985-01-01

    We propose a model of the nucleon and delta based on the idea that strong QCD forces on length scales approx.0.2--1 fm result in hidden chiral SU(2) x SU(2) symmetry and that there is a separation of roles between these forces which are also responsible for binding quarks in hadrons and the forces which produce absolute confinement. This leads us to study a linear sigma model describing the interactions of quarks, sigma mesons, and pions. We have solved this model in the semiclassical (mean-field) approximation for the hedgehog baryon state. We refer to this solution as a chiral soliton. In the semiclassical approximation the hedgehog state is a linear combination of N and Δ. We project this state onto states of good spin and isospin to calculate matrix elements of various operators in these states. Our results are in reasonable agreement with the observed properties of the nucleon. The mesonic contributions to g/sub A/ and sigma(πN) are about two to three times too large, suggesting the need for quantum corrections

  10. Length scale hierarchy and spatiotemporal change of alluvial morphologies over the Selenga River delta, Russia

    Science.gov (United States)

    Dong, T. Y.; Nittrouer, J.; McElroy, B. J.; Ma, H.; Czapiga, M. J.; Il'icheva, E.; Pavlov, M.; Parker, G.

    2017-12-01

    The movement of water and sediment in natural channels creates various types of alluvial morphologies that span length scales from dunes to deltas. The behavior of these morphologies is controlled microscopically by hydrodynamic conditions and bed material size, and macroscopically by hydrologic and geological settings. Alluvial morphologies can be modeled as either diffusive or kinematic waves, in accordance with their respective boundary conditions. Recently, it has been shown that the difference between these two dynamic behaviors of alluvial morphologies can be characterized by the backwater number, which is a dimensionless value normalizing the length scale of a morphological feature to its local hydrodynamic condition. Application of the backwater number has proven useful for evaluating the size of morphologies, including deltas (e.g., by assessing the preferential avulsion location of a lobe), and for comparing bedform types across different fluvial systems. Yet two critical questions emerge when applying the backwater number: First, how do different types of alluvial morphologies compare within a single deltaic system, where there is a hydrodynamic transition from uniform to non-uniform flow? Second, how do different types of morphologies evolve temporally within a system as a function of changing water discharge? This study addresses these questions by compiling and analyzing field data from the Selenga River delta, Russia, which include measurements of flow velocity, channel geometry, bed material grain size, and channel slope, as well as length scales of various morphologies, including dunes, island bars, meanders, bifurcations, and delta lobes. Data analyses reveal that the length scale of morphologies decrease and the backwater number increases as flow transitions from uniform to non-uniform conditions progressing downstream. It is shown that the evaluated length scale hierarchy and planform distribution of different morphologies can be used to

  11. The situation in the Niger Delta; La situation dans le delta du Niger

    Energy Technology Data Exchange (ETDEWEB)

    Vitalis, E

    2007-07-15

    An energy issue for the United States and a political challenge for Europe, Nigeria is experiencing growing instability and is on the verge of civil war; the ecosystem and the population of the Niger Delta are the main victims. The State, corrupt, is powerless to contain the rising violence and redistribute the proceeds of oil sales. It is high time for oil-consuming countries, starting with the United States, to concern themselves with stabilizing the region. Europe must contribute to the lasting development of this country. (author)

  12. The Niger Delta Avengers, Autonomous Ethnic Clans and Common ...

    African Journals Online (AJOL)

    Nneka Umera-Okeke

    therefore investigated the sudden emergence of Niger Delta Avengers ... hardship, deprivations and environmental degradation occasioned by oil pipeline .... analysis of coded materials of the library such as books, magazines, journals,.

  13. Rarotonga Radiocarbon (delta 14C) for 1950 to 1997

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Rarotonga coral radiocarbon (14C) timeseries. Coral radiocarbon (Delta-14C) on untreated, low-speed drilled samples. Precision is +/- 4 per mil as documented by an...

  14. Novel urinary metabolite of d-delta-tocopherol in rats

    International Nuclear Information System (INIS)

    Chiku, S.; Hamamura, K.; Nakamura, T.

    1984-01-01

    A novel metabolite of d-delta-tocopherol was isolated from the urine of rats given d-3,4-[ 3 H 2 ]-delta-tocopherol intravenously. The metabolite was collected from the urine of rats given d-delta-tocopherol in the same manner as that of the labeled compound. It was found that the metabolites consisted of sulfate conjugates. The portion of the major metabolite released with sulfatase was determined to be 2,8-dimethyl-2-(2'-carboxyethyl)-6-chromanol by infrared spectra, nuclear magnetic resonance spectra, and mass spectra. The proposed structure was confirmed by comparing the analytical results with those of a synthetically derived compound. As a result of the structural elucidation of this novel metabolite, a pathway for the biological transformation of delta-tocopherol is proposed which is different from that of alpha-tocopherol. A characteristic feature of the pathway is the absence of any opening of the chroman ring throughout the sequence

  15. Environmental Law and Underdevelopment in the Niger Delta ...

    African Journals Online (AJOL)

    Environmental Law and Underdevelopment in the Niger Delta Region of Nigeria. ... is composed of many ecosystems of great economic and social importance, ... producing companies contribute to the degradation of the environment which in ...

  16. Delta-ray spectroscopy of quasi-atoms

    International Nuclear Information System (INIS)

    Kozhuharov, C.

    1983-01-01

    The spectroscopy of high energy delta-rays, emitted in collisions of very heavy ions, is studied. The ''orange''-type beta-spectrometer and the achromatic electron channel are the experimental setups. Delta ray production probabilities are studied as a function of the distance of closest approach R /SUB min/ or the impact parameter b. Coulomb ionization, ion trajectory, scaling laws, double differential cross sections, and K-X-rays information is extracted from the experiment. The dependence of delta-ray emission on the united charge number Z /SUB u/ is discussed. Asymmetric collision systems with Z x alpha approx. = 1 (delta ray spectrum from Pb→Sn collisions) are studied. Finally, very heavy collisions, such as 208 Pb + 208 Pb collisions at bombarding energy fas below the Coulomb barrier are touched upon

  17. precise delta extraction scheme for reprogramming of wireless

    African Journals Online (AJOL)

    eobe

    Keywords- reprogramming; operating system, wireless sensor network, Delta. 1. INTRODUCTION ... It entails the transmission of only modified modules that are then ... higher power consumption and slow system execution are drawbacks ...

  18. Pattern of Complicated Unsafe Abortions in Niger Delta University ...

    African Journals Online (AJOL)

    Alasia Datonye

    of cases of complicated unsafe abortion managed at the. Niger Delta University ... previous termination of pregnancy and 87.3% of the patients had ... and outcome were obtained. ... life-threatening complications, post- abortion family planning.

  19. DEltas, vulnerability and Climate Change: Migration and Adaptation ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Hutton C.W.

    Stakeholder Dialogue, London, June 19th, 2014. DEltas, vulnerability and Climate. Change: Migration and Adaptation. (DECCMA). Stakeholder Dialogue. Radisson Blu Edwardian Grafton Hotel, London, UK. June 19th, 2014 ...

  20. Ecohealth Approach to Flood Recession Farming in Okavango Delta ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    In the Okavango Delta, Botswana, flood-recession farming (molapu) is a lucrative but ... Moreover, some practices involved in molapu farming may pose a threat to the ... Linking research to urban planning at the ICLEI World Congress 2018.

  1. What are Pregnant Women in a Rural Niger Delta Community's ...

    African Journals Online (AJOL)

    Erah

    Buchanan House, Glasgow Caledonian University Email: Caroline. ... exploratory qualitative study was carried out to identify pregnant women in a rural Niger Delta community's perceptions of ..... sometimes you stay for the whole day.

  2. Inventory Management in Delta Allied Wire Industries Limited Asaba ...

    African Journals Online (AJOL)

    A good inventory system reduces production cost and consequently increases profit. Optimum management of inventory in the Delta – Allied Wire Industries ... under review and customers' handling processes equally studied for improvement.

  3. Nucleon and delta masses in twisted mass chiral perturbation theory

    International Nuclear Information System (INIS)

    Walker-Loud, Andre; Wu, Jackson M.S.

    2005-01-01

    We calculate the masses of the nucleons and deltas in twisted mass heavy baryon chiral perturbation theory. We work to quadratic order in a power counting scheme in which we treat the lattice spacing, a, and the quark masses, m q , to be of the same order. We give expressions for the mass and the mass splitting of the nucleons and deltas both in and away from the isospin limit. We give an argument using the chiral Lagrangian treatment that, in the strong isospin limit, the nucleons remain degenerate and the delta multiplet breaks into two degenerate pairs to all orders in chiral perturbation theory. We show that the mass splitting between the degenerate pairs of the deltas first appears at quadratic order in the lattice spacing. We discuss the subtleties in the effective chiral theory that arise from the inclusion of isospin breaking

  4. Restoration of Delta Streams: A Case History and Conceptual Model

    National Research Council Canada - National Science Library

    Killgore, K. J; Hoover, Jan J; Murphy, Catherine E; Parrish, Kent D; Johnson, David R; Myers, Karen F

    2008-01-01

    .... Low water, excessive sedimentation in smaller delta streams, and the accumulation of pesticides such as DDT are the consequences of these anthropogenic disturbances resulting in dominance of tolerant fish species...

  5. LiDAR data for the Delta Area of California

    Data.gov (United States)

    California Natural Resource Agency — LiDAR data for the Delta Area of California from the California Department of Water Resources. Bare earth grids from LiDAR.This data is in ESRI Grid format with 2...

  6. Environmental Risk Profiling of the Volta Delta, Ghana

    Science.gov (United States)

    Nyarko, B. K.; Appeaning-Addo, K.; Amisigo, B.

    2017-12-01

    Volta Delta communities find it difficult to absorb or bear risk at different levels, because of the physical and economic impacts of environmental hazards. In this regards various agencies and organizations have in recent years launched initiatives to measure and identify risk areas with a set of indicators and indices. The theory underpinning this study is concepts of Modern Portfolio Theory (MPT). The Cox proportional hazards regression model will be used as the model for the risk profile. Finding the optimal level of environmental risk for activities in the Volta Delta considering the risk required, risk capacity and risk tolerance. Using data from different sources, an environmental risk profile was developed for the Volta Delta. The result indicates that risks are distributed across the Delta. However, areas that have government interventions, such as sea defense system and irrigation facilities have less threat. In addition wealthy areas do effectively reduce the threat of any form of disaster.

  7. Effective Lagrangians, Watson's theorem and the E2/M1 mixing ratio in the excitation of the Delta resonance

    International Nuclear Information System (INIS)

    Davidson, R.M.

    1992-01-01

    The author investigates theoretical uncertainties and model dependence in the extraction of the nucleon-delta(1232) electromagnetic transition amplitudes from the multipole data base. The starting point is an effective Lagrangian incorporating chiral symmetry, which includes at the tree level the pseudovector Born terms, leading t-channel vector meson exchanges, and s and u channel delta exchanges. The nucleon-delta magnetic dipole (M1) and electric quadrupole (E2) transition amplitudes are expressed in terms of two independent gauge couplings at the γNΔ vertex. After unitarizing the tree level amplitude, the gauge couplings are fitted to various multipole data sets, thus determining E2 and M1. Although there is much sensitivity to the method used to unitarize the amplitude, the author extracts the E2/M1 ratio to be negative, with a magnitude around 1.5%. 11 refs., 3 figs

  8. Sedimentation patterns in floodplains of the Mekong Delta - Vietnam

    Science.gov (United States)

    Van Manh, Nguyen; Merz, Bruno; Viet Dung, Nguyen; Apel, Heiko

    2013-04-01

    Quantification of floodplain sedimentation during the flood season in the Mekong Delta (MD) plays a very important role in the assessment of flood deposits for a sustainable agro-economic development. Recent studies on floodplain sedimentation in the region are restricted to small pilot sites because of the large extend of the Delta, and the complex channel. This research aims at a quantification of the sediment deposition in floodplains of the whole Mekong Delta, and to access the impacts of the upstream basin development on the sedimentation in the Delta quantitatively. To achieve this, a suspended sediment transport model is developed based on the quasi-2D hydrodynamic model of the whole Mekong Delta developed by Dung et al. (2011). The model is calibrated and validated using observed data derived from several sediment measurement campaigns in channel networks and floodplains. Measured sediment data and hydrodynamic model quantify the spatio-temporal variability of sediment depositions in different spatial units: individual dyke compartments, and the sub-regions Plain of Reeds, Long Xuyen Quadrangle and the area between Tien River and Hau River. It is shown that the distribution of sediment deposition over the delta is highly depended on the flood magnitude, that in turn drives the operation policy of flood control systems in floodplains of the Mekong Delta. Thus, the sedimentation distribution is influenced by the protection level of the dyke systems in place and the distance to the Tien River and Hau River, the main branches of the Mekong in the Delta. This corroborates the main findings derived from data analysis obtained from a small scale test site by Hung et al, (2011, 2012a). Moreover, the results obtained here underlines the importance of the main channels for the sediment transport into the floodplains, and the deposition rate in floodplains is strongly driven by the intake locations and the distance from these to the main channels as well.

  9. Studies of Louisiana's Deltas and Wetlands using SAR

    Science.gov (United States)

    Jones, C. E.

    2017-12-01

    Sustainable coastal environments exist in delicate balance between subsidence, erosion, and sea level rise on one hand and accretion of sediment and retention of decomposing organic matter on the other. In this talk we present results from a series of studies using an airborne L-band SAR (UAVSAR) to measure changing conditions in the Mississippi River Delta and coastal wetlands of Louisiana. Change within the Mississippi River delta (MRD), which is a highly engineered environment, is contrasted to those in the Wax Lake Delta, a small, naturally evolving delta located to the west of the current-day lobe of the MRD. The UAVSAR studies provide evidence that in the MRD subsidence and erosion related to human activities are increasing risk of flooding, submergence, and land loss. These are not seen in the Wax Lake Delta, where new land is forming. We evaluate geomorphic and hydrologic changes In the Wax Lake Delta and wetlands hydrologically connected to the Wax Lake Outlet canal that are apparent on the timescales of the UAVSAR data set, which consists of both near-yearly acquisitions (2009-2016) and several series of repeat acquisitions in 2015 and 2016 capturing conditions across a tidal cycle. Using the yearly data, we observe the evolution of subaqueous channels and crevasses in the delta and changes in distributary channels within the wetlands. We use water level change derived from InSAR applied to the rapid repeat data acquired during different stages of a tidal cycle to study the natural pattern of water flux within the delta and the coastal wetlands. The studies, results, and plans for future work will be presented. This work was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under contracts with the California Dept. of Water Resources and with the National Aeronautics and Space Administration.

  10. The Great Diversion: Danube Delta under Human Control (Invited)

    Science.gov (United States)

    Giosan, L.

    2009-12-01

    Many deltas around the world are suffering from sediment deficits that render them unstable to current and predicted rates of sea level rise. One solution proposed to alleviate the complete or partial drowning of such deltas is the use of river diversions to increase the quantity of sediment supplied to the delta plain to support marsh accretion. We examine the results of a half century old program of diversion in the Danube delta that led to the creation of an extensive diversion channel network akin in scope and size to a natural deltaic network. Danube’s importance as a shipping route increased after the Crimean War in the 1850s; the European Danube Commission was charged with maintaining the Sulina distributary as a shipping channel until 1940s. In the same period, several canals were dug to aid fishing in lakes and bring freshwater to brackish lagoons. After World War II, Communist authorities dramatically increased the number of canals for fishing, fish-farming and reed harvesting. New data on sedimentation rates and estimates of sediment fluxes suggest that the intensive canalization in the second half of the 20th Century led to increased sediment deposition that compensated the decreasing sediment discharge linked to damming within the internal fluvial part of the delta; however, the external marine delta has become increasingly sediment starved during the same interval. We emphasize the similarities and contrasts between the “human-controlled” and natural deltaic channel networks of the Danube delta and discuss the sustainability of the delta as a sediment budget problem within a sea level rise context.

  11. Challenges and Approaches in River Delta Planning - Annexes to report on training workshop

    NARCIS (Netherlands)

    Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

    2012-01-01

    Programme, participants and all powerpoint presentations of the Delta Alliance Training Workshop: Challenges and approaches in river delta planning, sharing experiences from SE Asian Deltas and the Rhine-Meuse Delta. 22-26 October 2012, WACC, Vietnam National University, Ho Chi Minh City, Vietnam

  12. Natural levee evolution in the Rhine-Meuse delta, the Netherlands, during the first millennium CE

    NARCIS (Netherlands)

    Pierik, H.J.; Stouthamer, E.; Cohen, K.M.

    2017-01-01

    This paper presents reconstructions on natural levee development in the Rhine-Meuse delta, the Netherlands, during the first millennium CE, covering the full delta plain. It is the first study that performs this on a delta scale, which allows seeing the delta-wide trends on levee-forming controls

  13. The Future of the Mississippi Delta: Shifting Baselines, Diminishing Resilience, and Growing Non-Sustainability

    Science.gov (United States)

    Day, J.

    2017-12-01

    Ecosystems and human communities of the Mississippi delta developed with predictable basin inputs, stable sea level, and as an open system with a high degree of interaction among drainage basin inputs, deltaic plain, and the coastal sea. Human activity changed altered the coast and lowered predictability. Management has become very energy intensive and dependent on cheap resources with more hard engineering and less ecological engineering. Pervasive alteration of the basin and delta and global change have altered the baseline and change is accelerating. Climate change projections include not only sea-level rise, but also more stronger hurricanes, increased large river floods, and more intense rainfall events and droughts. A sustainable Mississippi is outside of the boundaries of the current CMP.

  14. Optimal location of dry ports in the Pan-Pearl River Delta

    Directory of Open Access Journals (Sweden)

    Wu Qitao

    2017-01-01

    Full Text Available Dry ports have become a very important part of globalization and a cornerstone in port competitiveness. Based on the analytic hierarchy process, this paper established the dry port index system to evaluate the potential location of dry ports linked to the port system in the Pearl River Delta, in a case study covering 115 cities in the Pan - Pearl River Delta. The results show that it is optimal to locate 21 dry ports in the research region, and each dry port serves different areas. There are 4 optimal transport corridors for the dry port logistic network, including Guangzhou- Kunming transport corridor, Guangzhou-Chengdu transport corridor, Guangzhou-Changsha transport corridor and Shenzhen-Nanchang transport corridor.

  15. Design and Implementation of a New DELTA Parallel Robot in Robotics Competitions

    Directory of Open Access Journals (Sweden)

    Jonqlan Lin

    2015-10-01

    Full Text Available This investigation concerns the design and implementation of the DELTA parallel robot, covering the entire mechatronic process, involving kinematics, control design and optimizing methods. To accelerate the construction of the robot, 3D printing is used to fabricate end-effector parts. The parts are modular, low-cost, reconfigurable and can be assembled in less time than is required for conventionally fabricated parts. The controller, including the control algorithm and human-machine interface (HMI, is coded using the Borland C++ Builder 6 Personal software environment. The integration of the motion controller with image recognition into an opto-mechatronics system is presented. The robot system has been entered into robotic competitions in Taiwan. The experimental results reveal that the proposed DELTA robot completed the tasks in those competitions successfully.

  16. An integrated assessment framework for land subsidence in delta cities

    Directory of Open Access Journals (Sweden)

    T. H. M. Bucx

    2015-11-01

    Full Text Available In many delta cities land subsidence exceeds absolute sea level rise up to a factor of ten by excessive groundwater extraction related to rapid urbanization and population growth. Without change, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other delta (and coastal cities will sink below sea level. Increased flooding and also other widespread impacts of land subsidence result already in damage of billions of dollars per year. In order to gain insight in the complex, multi-sectoral aspects of subsidence, to raise awareness and to support decision making on appropriate adaptation strategies and measures, an Integrated Assessment Framework (IAF for subsidence is introduced, illustrated by several (delta case studies. Based on that a list of 10 generic key issues and possible solutions is presented in order to further develop and support a (generic approach how to deal with subsidence in current and future subsidence-prone areas. For exchange of experiences and knowledge development.on subsidence in deltas the Delta Alliance, a knowledge network of deltas worldwide, can be supportive.

  17. Sand transport, shear stress, and the building of a delta

    Science.gov (United States)

    Wagner, W.; Miller, K. L.; Hiatt, M. R.; Mohrig, D. C.

    2017-12-01

    River deltas distribute sediment to the coastal sea through a complex branching network of channels; however, the routing and storage of this sediment in and through the delta is poorly understood. We present results from field studies of the sediment and water transport through the branching Wax Lake Delta on the coast of Louisiana. Two channels studied, Main Pass and East Pass, maintain a near-equal total partitioning of flow and sediment. However, East Pass is narrower and has higher river velocities, lower tidal velocity fluctuations, less alluvial bed cover, and more sediment flux per unit width than Main Pass. We connect these differences to small differences in the geometry of the two channels and feedbacks between these differences. We link trends in measured sediment deposits to both measured and modeled shear velocities in Wax Lake Delta's channels and open water `islands' to understand how hydrologic processes shaped the sedimentary architecture of the delta. These connections define the sediment transport and deposition regimes in the WLD. We extend the results herein to suggest that the relationships between the available sediment and shear stress determines the basic planform of the Wax Lake Delta and cross-sectional geometries of its channels.

  18. The State of Bay–Delta Science 2016: An Introduction

    Directory of Open Access Journals (Sweden)

    Michael Healey

    2016-07-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2016v14iss2art5The State of Bay–Delta Science 2016 (SBDS is a collection of papers that summarizes the scientific understanding of the Sacramento–San Joaquin Delta, emphasizing progress made during the past decade.It builds on the first SBDS edition (Healey et al. 2008. Paper topics for this edition address the most relevant scientific issues in the Delta identified by senior scientists and managers. The topical papers cover issues ranging from contaminants in the Delta to levee stability, and from Delta food webs to recent discoveries about salmon migration. These papers are written for a scientific audience. Two additional papers, one describing the challenges of managing water and ecosystems in the Delta and another that discusses policy implications of the recent scientific findings, are written for a general audience. The papers will be published in at least two issues of San Francisco Estuary and Watershed Science and will be available as a set electronically.

  19. Metallicism and pulsation: an analysis of the delta Delphini stars

    International Nuclear Information System (INIS)

    Kurtz, D.W.

    1976-01-01

    Fine abundance analyses of seven delta Delphini stars and one delta Scuti star relative to four comparison standards are presented. Five of the delta Del stars are shown to have abundances most similar to the evolved Am stars. It is argued that these abundances are different from the classical Am star and Ap star abundances and that similarities to the Ba II star abundances are coincidental. We suggest that the anomalous abundance delta Del stars are evolved metallic line stars on the basis of their abundances, position in the β, M/sub v/ plane, inferred rotational velocities, and perhaps their binary incidence. Some of the delta Del stars are delta Scuti pulsators. We argue that pulsation and metallicism are mutually exclusive among the classical Am stars but may coexist in other stars related to the classical Am stars. A preference for the diffusion hypothesis model for the metallic line stars is stated and supported and the implications of the coexistence of pulsation and diffusion are discussed

  20. Designing a high-frequency nutrient and biogeochemical monitoring network for the Sacramento–San Joaquin Delta, northern California

    Science.gov (United States)

    Bergamaschi, Brian A.; Downing, Bryan D.; Kraus, Tamara E.C.; Pellerin, Brian A.

    2017-07-11

    Executive SummaryThis report is the third in a series of three reports that provide information about how high-frequency (HF) nutrient monitoring may be used to assess nutrient inputs and dynamics in the Sacramento–San Joaquin Delta, California (Delta). The purpose of this report is to provide the background, principles, and considerations for designing an HF nutrient-monitoring network for the Delta to address high-priority, nutrient-management questions. The report starts with discussion of the high-priority management questions to be addressed, continues through discussion of the questions and considerations that place demands and constraints on network design, discusses the principles applicable to network design, and concludes with the presentation of three example nutrient-monitoring network designs for the Delta. For three example network designs, we assess how they would address high-priority questions that have been identified by the Delta Regional Monitoring Program (Delta Regional Monitoring Program Technical Advisory Committee, 2015).This report, along with the other two reports of this series (Kraus and others, 2017; Downing and others, 2017), was drafted in cooperation with the Delta Regional Monitoring Program to help scientists, managers, and planners understand how HF data improve our understanding of nutrient sources and sinks, drivers, and effects in the Delta. The first report in the series (Kraus and others, 2017) provides an introduction to the reasons for and fundamental concepts behind using HF monitoring measurements, including a brief summary of nutrient status and trends in the Delta and an extensive literature review showing how and where other research and monitoring programs have used HF monitoring to improve our understanding of nutrient cycling. The report covers the various technologies available for HF nutrient monitoring and presents the different ways HF monitoring instrumentation may be used for both fixed station and spatial

  1. Integrated freshwater aquaculture, crop and livestock production in the Mekong delta, Vietnam: Determinants and the role of the pond

    NARCIS (Netherlands)

    Nhan, D.K.; Phong, L.T.; Verdegem, M.C.J.; Duong, L.T.; Bosma, R.H.; Little, D.C.

    2007-01-01

    Promotion of integrated aquaculture with agriculture, including crops and livestock (IAA-farming), requires consideration of both bio-physical and socio-economic contexts. The major factors influencing the adoption of IAA-farming by households at three sites in the Mekong delta were identified.

  2. Competition and niche segregation following the arrival of Hemigrapsus takanoi in the formerly Carcinus maenas dominated Dutch delta

    NARCIS (Netherlands)

    Brink, van den A.M.; Wijnhoven, S.; McLay, C.L.

    2012-01-01

    In a combined study including a 20 year monitoring programme of the benthic communities of four Dutch delta waters and a snapshot survey conducted in the Oosterschelde tidal bay in 2011, the populations of the native portunid European shore crab Carcinus maenas and the introduced varunid crabs

  3. The 39th Annual Phi Delta Kappa/Gallup Poll of the Public's Attitudes toward the Public Schools

    Science.gov (United States)

    Rose, Lowell C.; Gallup, Alec M.

    2007-01-01

    In this article, the authors report the results of the 39th Annual Phi Delta Kappa/Gallup Poll of the public's attitudes toward the public schools. This year's report examined the public's assessment of the No Child Left Behind (NCLB) and its principal strategy, standardized testing. The authors include a summary of key findings and tables showing…

  4. Recent coarsening of sediments on the southern Yangtze subaqueous delta front: A response to river damming

    Science.gov (United States)

    Yang, H. F.; Yang, S. L.; Meng, Y.; Xu, K. H.; Luo, X. X.; Wu, C. S.; Shi, B. W.

    2018-03-01

    After more than 50,000 dams were built in the Yangtze basin, especially the Three Gorges Dam (TGD) in 2003, the sediment discharge to the East China Sea decreased from 470 Mt/yr before dams to the current level of 140 Mt/yr. The delta sediment's response to this decline has interested many researchers. Based on a dataset of repeated samplings at 44 stations in this study, we compared the surficial sediment grain sizes in the southern Yangtze subaqueous delta front for two periods: pre-TGD (1982) and post-TGD (2012). External factors of the Yangtze River, including water discharge, sediment discharge and suspended sediment grain size, were analysed, as well as wind speed, tidal range and wave height of the coastal ocean. We found that the average median size of the sediments in the delta front coarsened from 8.0 μm in 1982 to 15.4 μm in 2012. This coarsening was accompanied by a decrease of clay components, better sorting and more positive skewness. Moreover, the delta morphology in the study area changed from an overall accretion of 1.0 cm/yr to an erosion of - 0.6 cm/yr. At the same time, the riverine sediment discharge decreased by 70%, and the riverine suspended sediment grain size increased from 8.4 μm to 10.5 μm. The annual wind speed and wave height slightly increased by 2% and 3%, respectively, and the tidal range showed no change trend. Considering the increased wind speed and wave height, there was no evidence that the capability of the China Coastal Current to transport sediment southward has declined in recent years. The sediment coarsening in the Yangtze delta front was thus mainly attributed to the delta's transition from accumulation to erosion which was originally generated by river damming. These findings have important implications for sediment change in many large deltaic systems due to worldwide human impacts.

  5. Morphodynamics and Sediment Transport on the Huanghe (Yellow River) Delta: Work in Progress

    Science.gov (United States)

    Kineke, G. C.; Calson, B.; Chadwick, A. J.; Chen, L.; Hobbs, B. F.; Kumpf, L. L.; Lamb, M. P.; Ma, H.; Moodie, A. J.; Mullane, M.; Naito, K.; Nittrouer, J. A.; Parker, G.

    2017-12-01

    Deltas are perhaps the most dynamic of coastal landforms with competing processes that deliver and disperse sediment. As part of the NSF Coastal SEES program, an interdisciplinary team of scientists from the US and China are investigating processes that link river and coastal sediment transport responsible for morphodynamic change of the Huanghe delta- an excellent study site due to its high sediment load and long history of natural and engineered avulsions, that is, abrupt shifts in the river course. A fundamental component of the study is a better understanding of sediment transport physics in a river system that transports mostly silt. Through theory and data analysis, we find that fine-grained rivers fail to develop full scale dunes, which results in faster water flow and substantially larger sediment fluxes as compared to sandy rivers (e.g. the Mississippi River). We also have developed new models for sediment-size dependent entrainment that are needed to make longer term predictions of river sedimentation patterns. On the delta front, we are monitoring the high sediment flux to the coast, which results in steep foresets and ideal conditions for off-shore sediment delivery via gravity flows. These constraints on sediment transport are being used to develop new theory for where and when rivers avulse - including the effects of variable flood discharge, sediment supply, and sea level rise -and how deltas ultimately grow through repeated cycles of lobe development. Flume experiments and field observations are being used to test these models, both in the main channel of the Huanghe and in channels abandoned after historic avulsions. Abandoned channels and floodplains are now dominated by coastal sediment transport through a combination of wave resuspension and tidal transport, settling lag and reverse estuarine circulation. Finally, the field and laboratory tested numerical models are being used as inputs to define a cost curve for efficient avulsion management of

  6. Lowstand Turbidites and Delta Systems of the Itararé Group in the Vidal Ramos region (SC, southern Brazil

    Directory of Open Access Journals (Sweden)

    Carla Gimena Puigdomenech

    Full Text Available Turbidites have captioned the attention of sedimentologists during the last decades due their importance as hydrocarbon reservoirs. However, their relationship to delta systems still deserves further studies. This paper presents examples from a late deglacial to early post-glacial deltaic and turbidite strata exposed in the surroundings of Vidal Ramos (Santa Catarina State, Brazil, southern portion of the Paraná Basin. There, the uppermost part of the Mafra Formation and the Rio do Sul Formation onlap the Proterozoic basement and comprises an up to 360 m thick package. It includes (base to top black shales, mass transport deposits (MTD and sandy turbidites (Mafra Formation as well as thin bedded turbidites (tbt, including one interval of black shales and sandy turbidites, overlain by proximal delta front sandstones (Rio do Sul Formation. The analysis of the succession shows two more than 150 m thick coarsening-upwards deltaic successions composed of turbidite sand sheets at their base (prodelta, followed by partially collapsed thin bedded turbidites (delta slope wedge and delta front sandstones. Both turbidite sand-sheets abruptly overlay black shale intervals related to maximum flooding surfaces and therefore record correlative conformities. A detailed stratigraphic section elaborated from the correlation of four logs (1/100 suggests that distal delta front sands includes both thin bedded turbidites and wave reworked sands whereas the proximal delta front was dominated by long-lived underflows (hyperpycnal flows. The succession suggests that the most expressive turbidite beds (base of the delta systems have resulted from relative sea-level falls (early lowstand whereas the thin-bedded turbidites were related to the development of the late lowstand wedge. Black shales represent the transgressive systems tract and HST were not deposited or preserved in the area. High sediment supply associated with lowstand tracts could explain the occasional

  7. Integrated Socio-Environmental Assessment of Deltas to Support Strategic Planning and Management

    Science.gov (United States)

    Nicholls, R. J.; Lázár, A. N.; Hutton, C.; Adams, H.; Salehin, M.; Rahman, M. M.

    2016-12-01

    Deltas are some of the most densely populated areas in the world, as exemplified by the coastal zone of Bangladesh which has a rural population densities of >1,000 people/km2. These people's livelihoods and food security are strongly dependent on natural resources which are influenced by multiple drivers. These include climate variability and change, subsidence, upstream river flow modifications, and land use changes such as polderisation and conversion of rice to shrimp production. Hydro-environmental changes, such as saline water intrusion and natural disasters (e.g. river flooding, cyclones and storm surges) have negative impacts that severely affect land use and livelihood opportunities of the coastal population. These changes can be especially detrimental for the well-being of the poorest households that are highly dependent on natural resources. These multiple drivers raise fundamental policy questions about how we might develop the delta over the coming decades. The Delta Dynamic Integrated Emulator (ΔDIEM) model has been developed to examine these interactions between the coupled bio-physical environment and the livelihoods of these poor populations in coastal Bangladesh. ΔDIEM allows the long-term analysis of the possible changes in this system by linking projected changes in physical processes (e.g. river flows, nutrients), with productivity (e.g. fish, rice), social processes (e.g. access, property rights, migration) and governance/management (e.g. fisheries, agriculture, water and land use management). A range of proposed interventions can be simulated. This integrated approach is designed to provide Bangladeshi policy makers with science-based evidence of possible development trajectories within the coastal delta plain over timescales up to 50 years, including comprehensive analysis of their different choices in terms of natural resource conservation, poverty, etc. This presentation will focus on key results and insights from the analysis.

  8. How yield relates to ash content, Delta 13C and Delta 18O in maize grown under different water regimes.

    Science.gov (United States)

    Cabrera-Bosquet, Llorenç; Sánchez, Ciro; Araus, José Luis

    2009-11-01

    Stable isotopes have proved a valuable phenotyping tool when breeding for yield potential and drought adaptation; however, the cost and technical skills involved in isotope analysis limit its large-scale application in breeding programmes. This is particularly so for Delta(18)O despite the potential relevance of this trait in C(4) crops. The accumulation of minerals (measured as ash content) has been proposed as an inexpensive way to evaluate drought adaptation and yield in C(3) cereals, but little is known of the usefulness of this measure in C(4) cereals such as maize (Zea mays). The present study investigates how yield relates to ash content, Delta(13)C and Delta(18)O, and evaluates the use of ash content as an alternative or complementary criterion to stable isotopes in assessing yield potential and drought resistance in maize. A set of tropical maize hybrids developed by CIMMYT were subjected to different water availabilities, in order to induce water stress during the reproductive stages under field conditions. Ash content and Delta(13)C were determined in leaves and kernels. In addition, Delta(18)O was measured in kernels. Water regime significantly affected yield, ash content and stable isotopes. The results revealed a close relationship between ash content in leaves and the traits informing about plant water status. Ash content in kernels appeared to reflect differences in sink-source balance. Genotypic variation in grain yield was mainly explained by the combination of ash content and Delta(18)O, whilst Delta(13)C did not explain a significant percentage of such variation. Ash content in leaves and kernels proved a useful alternative or complementary criterion to Delta(18)O in kernels for assessing yield performance in maize grown under drought conditions.

  9. Mean proloculus size, delta super(13) C and delta super(18) O variations in recent benthic foraminifera from the west coast of India and their climatic implications

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; Sarkar, A.

    The interrelationship between mean proloculus size (MPS), delta super(18) O and delta super(13) C vatiations in benthic foraminiferal species Rotalidium annectens and their relation with temperature (T) and salinity (S) have been studied in samples...

  10. Parapapillary atrophy: histological gamma zone and delta zone.

    Directory of Open Access Journals (Sweden)

    Jost B Jonas

    Full Text Available BACKGROUND: To examine histomorphometrically the parapapillary region in human eyes. METHODOLOGY/PRINCIPAL FINDINGS: The histomorphometric study included 65 human globes (axial length:21-37 mm. On anterior-posterior histological sections, we measured the distance Bruch's membrane end (BME-optic nerve margin ("Gamma zone", BME-retinal pigment epithelium (RPE ("Beta zone", BME-beginning of non-occluded choriocapillaris, and BME-beginning of photoreceptor layer. "Delta zone" was defined as part of gamma zone in which blood vessels of at least 50 µm diameter were not present over a length of >300 µm. Beta zone (mean length:0.35±0.52 mm was significantly (P = 0.01 larger in the glaucoma group than in the non-glaucomatous group. It was not significantly (P = 0.28 associated with axial length. Beta zone was significantly (P = 0.004 larger than the region with occluded choriocapillaris. Gamma zone (mean length:0.63±1.25 mm was associated with axial length (P50 µm diameter within gamma zone was present only in highly axially elongated globes and was not related with glaucoma. Beta zone (Bruch's membrane without RPE was correlated with glaucoma but not with globe elongation. Since the region with occluded choriocapillaris was smaller than beta zone, complete loss of RPE may have occurred before complete choriocapillaris closure.

  11. GRK2 Constitutively Governs Peripheral Delta Opioid Receptor Activity

    Directory of Open Access Journals (Sweden)

    Allison Doyle Brackley

    2016-09-01

    Full Text Available Opioids remain the standard for analgesic care; however, adverse effects of systemic treatments contraindicate long-term administration. While most clinical opioids target mu opioid receptors (MOR, those that target the delta class (DOR also demonstrate analgesic efficacy. Furthermore, peripherally restrictive opioids represent an attractive direction for analgesia. However, opioid receptors including DOR are analgesically incompetent in the absence of inflammation. Here, we report that G protein-coupled receptor kinase 2 (GRK2 naively associates with plasma membrane DOR in peripheral sensory neurons to inhibit analgesic agonist efficacy. This interaction prevents optimal Gβ subunit association with the receptor, thereby reducing DOR activity. Importantly, bradykinin stimulates GRK2 movement away from DOR and onto Raf kinase inhibitory protein (RKIP. protein kinase C (PKC-dependent RKIP phosphorylation induces GRK2 sequestration, restoring DOR functionality in sensory neurons. Together, these results expand the known function of GRK2, identifying a non-internalizing role to maintain peripheral DOR in an analgesically incompetent state.

  12. Lava delta deformation as a proxy for submarine slope instability

    Science.gov (United States)

    Di Traglia, Federico; Nolesini, Teresa; Solari, Lorenzo; Ciampalini, Andrea; Frodella, William; Steri, Damiano; Allotta, Benedetto; Rindi, Andrea; Marini, Lorenzo; Monni, Niccolò; Galardi, Emanuele; Casagli, Nicola

    2018-04-01

    The instability of lava deltas is a recurrent phenomenon affecting volcanic islands, which can potentially cause secondary events such as littoral explosions (due to interactions between hot lava and seawater) and tsunamis. It has been shown that Interferometric Synthetic Aperture Radar (InSAR) is a powerful technique to forecast the collapse of newly emplaced lava deltas. This work goes further, demonstrating that the monitoring of lava deltas is a successful strategy by which to observe the long-term deformation of subaerial-submarine landslide systems on unstable volcanic flanks. In this paper, displacement measurements derived from Synthetic Aperture Radar (SAR) imagery were used to detect lava delta instability at Stromboli volcano (Italy). Recent flank eruptions (2002-2003, 2007 and 2014) affected the Sciara del Fuoco (SdF) depression, created a "stacked" lava delta, which overlies a pre-existing scar produced by a submarine-subaerial tsunamigenic landslide that occurred on 30 December 2002. Space-borne X-band COSMO-SkyMED (CSK) and C-band SENTINEL-1A (SNT) SAR data collected between February 2010 and October 2016 were processed using the SqueeSAR algorithm. The obtained ground displacement maps revealed the differential ground motion of the lava delta in both CSK and SNT datasets, identifying a stable area (characterized by less than 2 mm/y in both datasets) within the northern sector of the SdF and an unstable area (characterized by velocity fields on the order of 30 mm/y and 160 mm/y in the CSK and SNT datasets, respectively) in the central sector of the SdF. The slope stability of the offshore part of the SdF, as reconstructed based on a recently performed multibeam bathymetric survey, was evaluated using a 3D Limit Equilibrium Method (LEM). In all the simulations, Factor of Safety (F) values between 0.9 and 1.1 always characterized the submarine slope between the coastline and -250 m a.s.l. The critical surfaces for all the search volumes corresponded to

  13. Initial isotopic geochemistry ({delta} 18 O, {delta} D) of fluids from wells of the Los Humeros, Pue., geothermal field; Geoquimica isotopica ({delta} 18 O, {delta} D) inicial de fluidos de pozos del campo geotermico de Los Humeros, Pue.

    Energy Technology Data Exchange (ETDEWEB)

    Barragan Reyes, Rosa Maria; Arellano Gomez, Victor Manuel [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Ramirez Montes, Miguel; Tovar Aguado, Rigoberto [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)

    2010-01-15

    Isotopic data ({delta} 18 O, {delta} D) from fluids from production wells at the Los Humeros, Pue., geothermal field were analyzed to investigate the possible origin of these fluids and the dominant processes of the reservoir at its initial state. According to pre-exploitation data, it is suggested the Los Humeros reservoir fluids are made of a mixture of meteoric water of very light isotopic composition (paleo-fluids) and andesitic water. The relationship {delta} D vs {delta} 18 O from pre-exploitation data indicates the produced fluids are composed of a mixture of (at least) two fluids with distinct isotopic compositions. At the more enriched end of the mixing relationship are the isotopic compositions of the wells H-23 and H-18 (located in the southern area of the field), while the lighter fluids were found in well H-16 (originally) and then in well H-16 (repaired). It was found that the liquid phases of deep wells are more enriched in {delta} 18 O while the shallow wells present lower values, suggesting a convection process at the initial state. Based on this isotopic profile, it is considered that even the production depths of the wells H-1, H-12 and H-16 (repaired) are just about the same, but their respective isotopic compositions are quite different. The {delta} 18 O value for well H-16 (repaired) seems to be that of condensate steam, while the corresponding values for wells H-1 and H-12 fall within the value interval of the deep wells (H-23). This suggests wells H-1 and H-12 are collecting very deep fluids enriched in {delta} 18 O. These results could be useful in creating a conceptual model of the reservoir. [Spanish] Se analizaron datos isotopicos ({delta}18 O, {delta}D) de los fluidos de pozos productores del campo geotermico de Los Humeros, Pue., para investigar el posible origen de los fluidos asi como los procesos dominantes del yacimiento en su estado inicial. De acuerdo con datos previos a la explotacion, se plantea que los fluidos del yacimiento

  14. Stratigraphy and paleohydrology of delta channel deposits, Jezero crater, Mars

    Science.gov (United States)

    Goudge, Timothy A.; Mohrig, David; Cardenas, Benjamin T.; Hughes, Cory M.; Fassett, Caleb I.

    2018-02-01

    The Jezero crater open-basin lake contains two well-exposed fluvial sedimentary deposits formed early in martian history. Here, we examine the geometry and architecture of the Jezero western delta fluvial stratigraphy using high-resolution orbital images and digital elevation models (DEMs). The goal of this analysis is to reconstruct the evolution of the delta and associated shoreline position. The delta outcrop contains three distinct classes of fluvial stratigraphy that we interpret, from oldest to youngest, as: (1) point bar strata deposited by repeated flood events in meandering channels; (2) inverted channel-filling deposits formed by avulsive distributary channels; and (3) a valley that incises the deposit. We use DEMs to quantify the geometry of the channel deposits and estimate flow depths of ∼7 m for the meandering channels and ∼2 m for the avulsive distributary channels. Using these estimates, we employ a novel approach for assessing paleohydrology of the formative channels in relative terms. This analysis indicates that the shift from meandering to avulsive distributary channels was associated with an approximately four-fold decrease in the water to sediment discharge ratio. We use observations of the fluvial stratigraphy and channel paleohydrology to propose a model for the evolution of the Jezero western delta. The delta stratigraphy records lake level rise and shoreline transgression associated with approximately continuous filling of the basin, followed by outlet breaching, and eventual erosion of the delta. Our results imply a martian surface environment during the period of delta formation that supplied sufficient surface runoff to fill the Jezero basin without major drops in lake level, but also with discrete flooding events at non-orbital (e.g., annual to decadal) timescales.

  15. Anadromous salmonids in the Delta: New science 2006–2016

    Science.gov (United States)

    Perry, Russell W.; Buchanan, Rebecca A.; Brandes, Patricia L.; Burau, Jon R.; Israel, Joshua A

    2016-01-01

    As juvenile salmon enter the Sacramento–SanJoaquin River Delta (“the Delta”) they disperse among its complex channel network where they are subject to channel-specific processes that affect their rate of migration, vulnerability to predation, feeding success, growth rates, and ultimately, survival. In the decades before 2006, tools available to quantify growth, dispersal, and survival of juvenile salmon in this complex channel network were limited.Fortunately, thanks to technological advances such as acoustic telemetry and chemical and structural otolith analysis, much has been learned over the past decade about the role of the Delta in the life cycle of juvenile salmon. Here, we review new science between 2006and 2016 that sheds light on how different life stages and runs of juvenile salmon grow, move, and survive in the complex channel network of the Delta. One of the most important advances during the past decade has been the widespread adoption of acoustic telemetry techniques. Use of telemetry has shed light on how survival varies among alternative migration routes and the proportion of fish that use each migration route. Chemical and structural analysis of otoliths has provided insights about when juveniles left their natal river and provided evidence of extended rearing in the brackish or saltwater regions of the Delta. New advancements in genetics now allow individuals captured by trawls to be assigned to specific runs. Detailed information about movement and survival in the Delta has spurred development of agent-based models of juvenile salmon that are coupled to hydrodynamic models. Although much has been learned, knowledge gaps remain about how very small juvenile salmon (fry and parr) use the Delta. Understanding how all life stages of juvenile salmon grow, rear, and survive in the Delta is critical for devising management strategies that support a diversity of life history strategies.

  16. Clinical applications of gamma delta T cells with multivalent immunity

    Directory of Open Access Journals (Sweden)

    Drew C Deniger

    2014-12-01

    Full Text Available Gamma delta T cells hold promise for adoptive immunotherapy because of their reactivity to bacteria, viruses, and tumors. However, these cells represent a small fraction (1-5% of the peripheral T-cell pool and require activation and propagation to achieve clinical benefit. Aminobisphosphonates specifically expand the Vgamma9Vdelta2 subset of gamma delta T cells and have been used in clinical trials of cancer where objective responses were detected. The Vgamma9Vdelta2 TCR heterodimer binds multiple ligands and results in a multivalent attack by a monoclonal T cell population. Alternatively, populations of gamma delta T cells with oligoclonal or polyclonal TCR repertoire could be infused for broad-range specificity. However, this goal has been restricted by a lack of applicable expansion protocols for non-Vgamma9Vdelta2 cells. Recent advances using immobilized antigens, agonistic monoclonal antibodies (mAbs, tumor-derived artificial antigen presenting cells (aAPC, or combinations of activating mAbs and aAPC have been successful in expanding gamma delta T cells with oligoclonal or polyclonal TCR repertoires. Immobilized MHC Class-I chain-related A was a stimulus for gamma delta T cells expressing TCRdelta1 isotypes, and plate-bound activating antibodies have expanded Vdelta1 and Vdelta2 cells ex vivo. Clinically-sufficient quantities of TCRdelta1, TCRdelta2, and TCRdelta1negTCRdelta2neg have been produced following co-culture on aAPC, and these subsets displayed differences in memory phenotype and reactivity to tumors in vitro and in vivo. Gamma delta T cells are also amenable to genetic modification as evidenced by introduction of alpha beta TCRs, chimeric antigen receptors (CARs, and drug-resistance genes. This represents a promising future for the clinical application of oligoclonal or polyclonal gamma delta T cells in autologous and allogeneic settings that builds on current trials testing the safety and efficacy of Vgamma9Vdelta2 T cells.

  17. Evidence of an Exponential Decay Pattern of the Hepatitis Delta Virus Evolution Rate and Fluctuations in Quasispecies Complexity in Long-Term Studies of Chronic Delta Infection.

    Directory of Open Access Journals (Sweden)

    Maria Homs

    Full Text Available Chronic HDV infection can cause a severe form of viral hepatitis for which there is no specific treatment. Characterization of the hepatitis B or C viral quasispecies has provided insight into treatment failure and disease recurrence following liver transplantation, has proven useful to understand hepatitis B e antigen seroconversion, and has helped to predict whether hepatitis C infection will resolve or become chronic. It is likely that characterization of the hepatitis delta virus (HDV quasispecies will ultimately have similar value for the management of this infection. This study sought to determine the RNA evolution rates in serum of chronic hepatitis delta (CHD treatment-naïve patients, using next-generation sequencing methods. The region selected for study encompassed nucleotide positions 910 to 1270 of the genome and included the amber/W codon. Amber/W is a substrate of the editing process by the ADAR1 host enzyme and is essential for encoding the 2 delta antigens (HDAg. The amber codon encodes the small (unedited HDAg form and the W codon the large (edited HDAg form. The evolution rate was analyzed taking into account the time elapsed between samples, the percentage of unedited and edited genomes, and the complexity of the viral population. The longitudinal studies included 29 sequential samples from CHD patients followed up for a mean of 11.5 years. In total, 121,116 sequences were analyzed. The HDV evolution rate ranged from 9.5x10-3 to 1.2x10-3 substitutions/site/year and showed a negative correlation with the time elapsed between samples (p<0.05. An accumulation of transition-type changes was found to be responsible for higher evolution rates. The percentages of unedited and edited genomes and the quasispecies complexity showed no relationships with the evolution rate, but the fluctuations in the percentages of genomes and in complexity suggest continuous adaptation of HDV to the host conditions.

  18. Challenges and Approaches in Delta Planning and Management - Sharing experiences from SE Asian Deltas and the Rhine-Meuse Delta -Report on Regional Training Workshop

    NARCIS (Netherlands)

    Long Phi, H.; Fida Abdullah Khan, M.; Wosten, J.H.M.; Douven, W.

    2014-01-01

    The training workshop consisted of a balanced mix of lectures on specific delta topics, work on group assignments, group and plenary discussions, and group presentations. Due to high professional level of the participants the discussions often reached the level of a policy dialogue among equals

  19. IMPACTS OF WETLAND DEGRADATION IN NIGER DELTA NIGERIA AND ITS SIGNIFICANCE IN FLOOD CONTROL

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    Enwere Chidimma Loveline

    2015-08-01

    Full Text Available  Wetlands perform a wide variety of functions that include flood control, ground water recharge, shore line stabilization, storm protection and climate moderation. However, despite these huge wetland functions, it has witnessed poor appreciation and dreadful conditions. Niger Delta has witnessed constant coastal erosion and rising sea level, this has led to large portions of the landmass being eroded. This paper aims to review some environmental effects of flooding in the Niger Delta region of Nigeria to provide the desired knowledge of role that wetlands play in reducing flood impacts. However, having witnessed the flood, the experience opened my eyes to the environmental challenges facing Niger Delta with respect to Wetlands degradation, poor perception of wetland values and functions, poor environmental practices and non-implementation of environmental regulations. This memorable experience rekindled the desire and motivation to seek a solution to wetland degradation with the aim of recognizing significance of wetlands at the centre of achieving both livelihood and biodiversity improvements to address coastal flooding problem.The study therefore concludes that wetlands are very significant in flood control and thus the conservation and restoration of wetlands, should put in place measures to reduce wetland destruction.International Journal of EnvironmentVolume-4, Issue-3, June-August 2015Page: 177-184

  20. Modeling of the Ebola Virus Delta Peptide Reveals a Potential Lytic Sequence Motif

    Directory of Open Access Journals (Sweden)

    William R. Gallaher

    2015-01-01

    Full Text Available Filoviruses, such as Ebola and Marburg viruses, cause severe outbreaks of human infection, including the extensive epidemic of Ebola virus disease (EVD in West Africa in 2014. In the course of examining mutations in the glycoprotein gene associated with 2014 Ebola virus (EBOV sequences, a differential level of conservation was noted between the soluble form of glycoprotein (sGP and the full length glycoprotein (GP, which are both encoded by the GP gene via RNA editing. In the region of the proteins encoded after the RNA editing site sGP was more conserved than the overlapping region of GP when compared to a distant outlier species, Tai Forest ebolavirus. Half of the amino acids comprising the “delta peptide”, a 40 amino acid carboxy-terminal fragment of sGP, were identical between otherwise widely divergent species. A lysine-rich amphipathic peptide motif was noted at the carboxyl terminus of delta peptide with high structural relatedness to the cytolytic peptide of the non-structural protein 4 (NSP4 of rotavirus. EBOV delta peptide is a candidate viroporin, a cationic pore-forming peptide, and may contribute to EBOV pathogenesis.

  1. Fingerprinting analysis and characterization of hydrocarbons in sediments of the Pearl River Delta in China

    International Nuclear Information System (INIS)

    Yang, C.; Wang, Z.; Hollebone, B.; Yang, Z.; Brown, C.; Landriault, M.; Peng, X.

    2009-01-01

    This paper reported on a study that used gas chromatography-mass spectrometry (GC-MS) and gas chromatography flame ionization detection (GC-FID) to investigate and characterize the contamination in southern China's Pearl River Delta, with particular reference to contamination from petroleum,n-alkanes, polycyclic aromatic hydrocarbons (PAHs), biomarkers and diamondoid compounds. Forensic analysis of sediments was necessary in order to decode the contamination history and evaluate the contamination level of the aquatic ecosystem. The contamination of the Pearl River Delta sediment was derived from various inputs, including petrogenic, biogenic and pyrogenic sources. However, in addition to identifying PAHs and biomarker terpanes and steranes, the detection of trace diamondoid compounds in the sediments demonstrated that the pollution in the river was derived partially from petroleum sources. Diamondoids are a class of saturated hydrocarbons that consist of three-dimensionally fused cyclohexane rings. They occur naturally in source rocks, crude oils, intermediate petroleum distillates, and finished petroleum products. They are more resistant to biodegradation than most other petroleum compounds such as n-alkanes. As such, they can play an important role in identifying and characterizing petroleum contamination in the environment. It was concluded that the petroleum contamination in the Pearl River Delta is attributed to the mixture of medium to heavy petroleum residues. 31 refs., 6 tabs., 4 figs

  2. Population decline in the Delta caribou herd with reference to other Alaskan herds

    Directory of Open Access Journals (Sweden)

    Patrick Valkenburg et al.

    1996-01-01

    Full Text Available After growing continuously for nearly 15 years, the Delta caribou herd began to decline in 1989. Most other Interior Alaskan herds also began declining. In the Delta herd, and in other herds, the declines were caused primarily by high summer mortality of calves and increased natural mortality of adult females. Other minor causes included increased winter mortality of calves, and reduced parturition rates of 3-year-old and older females. The decline in the Delta herd also coincided with increased wolf (Canis lupus numbers, winters with deeper than normal snow, and warm summers. Mean body weight of annual samples of 10-month-old female calves was consistently low during the decline. Except in some of the smallest Interior Alaskan herds, we conclude that evidence for population regulation in Alaskan caribou is weak, and that herds are likely to fluctuate within a wide range of densities due to complex interactions of predation and weather. Unless wolf numbers are influenced by man, the size of a caribou herd in a given year is likely to be largely a function of its size during the previous population low and the number of years of favorable weather in the interim.

  3. Valence band states in Si-based p-type delta-doped field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Orozco, J C; Vlaev, Stoyan J, E-mail: jcmover@correo.unam.m [Unidad Academica de Fisica, Universidad Autonoma de Zacatecas, Calzada Solidaridad esquina con Paseo la Bufa S/N, C.P. 98060, Zacatecas, Zac. (Mexico)

    2009-05-01

    We present tight-binding calculations of the hole level structure of delta-doped Field Effect Transistor in a Si matrix within the first neighbors sp{sup 3}s* semi-empirical tight-binding model including spin. We employ analytical expressions for Schottky barrier potential and the p-type delta-doped well based on a Thomas-Fermi approximation, we consider these potentials as external ones, so in the computations they are added to the diagonal terms of the tight-binding Hamiltonian, by this way we have the possibility to study the energy levels behavior as we vary the backbone parameters in the system: the two-dimensional impurity density (p{sub 2d}) of the p-type delta-doped well and the contact voltage (V{sub c}). The aim of this calculation is to demonstrate that the tight-binding approximation is suitable for device characterization that permits us to propose optimal values for the input parameters involved in the device design.

  4. Water Management Strategy in Assessing the Water Scarcity in Northern Western Region of Nile Delta, Egypt

    Science.gov (United States)

    Mabrouk, Badr; Arafa, Salah; Gemajl, Khaled

    2015-04-01

    Sustainable development in the Nile Delta of Egypt is retarded by serious environmental problems, where land-use and land-cover of the region are subjected to continuous changes; including shoreline changes either by erosion or accretion, subsidence of the delta, as well as by sea level rise due to climate change. The current research attempts to; (1) study the vulnerability of the northern western region of the Nile Delta coastal zone to climate change/sea level rise while setting basic challenges, review adaptation strategies based on adaptation policy framework, and highlight recommended programs for preparedness to climate change, (2) study the scarcity of water resources in the area of study with review of the socioeconomic impacts and the critical need of establishing desalination plants with new standards assessing the environmental situation and population clusters, and (3) monitor of the brine water extracted from the desalination plants and injected to subsurface strata. This monitoring process is divided into 3 main directions: 1) studying the chemical characteristics of water extracted from the water desalinations plants qualitatively and quantitatively. 2) mapping the subsurface of which that brine water will be injected to it and the flow directions and effects using resistivity data, and 3) using GIS and suitable numerical models in order to study the effect, volume, flow of the brine water and its long term environmental impacts on the area. The results indicate that the area is particularly vulnerable to the impact of SLR, salt water intrusion, the deterioration of coastal tourism and the impact of extreme dust storms. This in turn will directly affect the agricultural productivity and human settlements in coastal zones. The paper presents different scenarios for water management and recommends the most suitable scenarios in order to establish a core for water management strategy in the region according to existing socio-economic and environmental

  5. Dispersion Mechanisms of a Tidal River Junction in the Sacramento–San Joaquin Delta, California

    Directory of Open Access Journals (Sweden)

    Karla T. Gleichauf

    2014-12-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2014v12iss4art1In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Doppler Current Profile (ADCP boat transecting and moored ADCPs over a spring–neap tidal cycle (May to  June 2012 monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011 advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales. The study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby

  6. Doubly truncated FosB isoform (Delta2DeltaFosB) induces osteosclerosis in transgenic mice and modulates expression and phosphorylation of Smads in osteoblasts independent of intrinsic AP-1 activity

    DEFF Research Database (Denmark)

    Sabatakos, George; Rowe, Glenn C; Kveiborg, Marie

    2008-01-01

    DeltaFosB and a further truncated isoform (Delta2DeltaFosB) that lacks known transactivation domains but, like DeltaFosB, induces increased expression of osteoblast marker genes. MATERIALS AND METHODS: To test Delta2DeltaFosB's ability to induce bone formation in vivo, we generated transgenic mice......6 expression. CONCLUSIONS: DeltaFosB's AP-1 transactivating function is not needed to induce increased bone formation, and Delta2DeltaFosB may act, at least in part, by increasing Smad1 expression, phosphorylation, and translocation to the nucleus....

  7. Human induced discharge diversion in a tropical delta and its environmental implications: The Patía River, Colombia

    Science.gov (United States)

    Restrepo, Juan D.; Kettner, Albert

    2012-03-01

    SummaryThe Patía River, the number one in terms of sediment yield ˜1500 t km-2 yr-1 draining the western South America, has the most extensive and well developed delta on the Pacific coast, measuring 1700 km2. During the Holocene, nature forced the Patía delta to the south; however, a major water diversion, starting in 1972, diverted the Patía flow to the Sanguianga River, the latter, a small stream draining internal lakes from the Pacific lowlands. This human induced discharge diversion shifted the active delta plain back to the north and changed the northern estuarine system into an active delta plain. Overall, major environmental consequences of this discharge diversion in terms of morphological changes along the delta coast and distributary channels, are evidenced by: (1) coastal retreat along the abandoned delta lobe; 63% of the southern shoreline is retreating at maximum rates of 7 m yr-1, with a corresponding coastal land loss of 106 m yr-1; (2) transgressive barrier islands with exposed peat soils in the surf zone; (3) abandonment of former active distributaries in the southern delta plain with associated closing of inlets and formation of ebb tidal deltas; (4) breaching events on barrier islands; and (5) distributary channel accretion in the northern delta plain by morphological processes such as sedimentation (also in crevasses), overbank flow, increasing width of levees, interdistributary channel fill, and colonization of pioneer mangrove. The Sanguianga Mangrove National Park (SMNP), the largest mangrove reserve in Colombia, measuring 800 km2, lies in this former estuary, where major hydrologic and sedimentation changes are occurring. Observed environmental changes in the SMNP, include (1) seaward advance of the sub-aqueous delta front at the Sanquianga inlet evidenced by an increase in tidal flat area from 5.4 Mm2 in 1986 to 14 Mm2 in 2001; (2) freshening conditions in the Sanguianga distributary channel, a hydrologic change that has shifted the

  8. Hydrology and morphology of two river mouth regions (temperate Vistula Delta and subtropical Red River Delta

    Directory of Open Access Journals (Sweden)

    Zbigniew Pruszak

    2005-09-01

    Full Text Available The paper presents a comparative analysis of two different river mouths from two different geographical zones (subtropical and temperate climatic regions. One is the multi-branch and multi-spit mouth of the Red River on the Gulf of Tonkin (Vietnam, the other is the smaller delta of the river Vistula on a bay of the Baltic Sea (Poland. The analysis focuses on the similarities and differences in the hydrodynamics between these estuaries and the adjacent coastal zones, the features of sediment transport, and the long-term morphodynamics of the river outlets. Salinity and water level are also discussed, the latter also in the context of the anticipated global effect of accelerated sea level rise. The analysis shows that the climatic and environmental conditions associated with geographical zones give rise to fundamental differences in the generation and dynamic evolution of the river mouths.

  9. Geochronology of priority pollutants in sedimentation zones of the Volga and Danube delta in comparison with the Rhine delta

    International Nuclear Information System (INIS)

    Winkels, H.J.; Kroonenberg, S.B.; Lychagin, M.Y.; Marin, G.; Rusakov, G.V.; Kasimov, N.S.

    1998-01-01

    Six sediment cores were taken in sedimentation zones of the Volga river (located in the southern part of the Russian Federation) and, additionally, 6 sediment cores were taken in several lakes (sedimentation zones) in the central and western part of the Danube delta in Romania. Priority pollutants (8 metals, 7 polychlorinated biphenyls and 10 polycyclic aromatic hydrocarbons) were determined in all samples of all cores. Present-day and historical levels of pollutants since the late 1930s were established through the use of radionuclide time tracers ( 137 Cs, 134 Cs). For the persistent metals and polycyclic aromatic hydrocarbons, trends in the concentration profiles during the last 5 decades are described. Low and hardly changing concentrations of As, Cu, Zn and all studied PAHs were observed during the last five decades in the sediments of the Volga river. Recently deposited sediments show slightly increasing levels for the heavy metals Zn and Cr and As in the Volga delta. For the studied metals and PAHs, maximum concentrations were found around 1987 in the sediments of the Danube delta. Sediments deposited around 1940 and recently deposited sediments in the Danube delta showed lower pollutant levels. If the contents of heavy metals, PAHs and PCBs in the aquatic sediments in the deltas of the rivers Rhine, Danube and Volga are compared, it is clear that the Volga delta is and was the cleanest delta during the last 5 decades. Nowadays the contents of heavy metals (except Cu and Ni), PAHs and PCBs in the aquatic sediments of the river Rhine are still highest compared to the other two rivers. The recent load of heavy metals (except Cd and Zn) in the sediments of the river Danube is the highest compared to the other two rivers. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Delta Cafés (Portugal: Sustainable Business Development

    Directory of Open Access Journals (Sweden)

    Olgierd Swiatkiewicz

    2017-12-01

    Full Text Available In the case study of Delta Cafés we discuss the sustainable development of the Portuguese company and brand over the 55 years of their existence. Delta Cafés has already been analyzed in terms of marketing activity, social responsibility, management control systems, etc. In this paper, we refer to these studies, and we reach the sources, i.e. the information provided by the Delta Cafés itself. Due to the nature of the coffee market and the use of case study methodology, we start the presentation of this case from a broader context, describing the coffee market in the world and characterizing the coffee market in Portugal as well. Then we present the history of the development of the company and the brand Delta Cafés. The paper ends with concluding remarks in which we discuss the issues of social and environmental responsibility in the light of the development of Delta Cafés business and brand strategies. 

  11. Soil Organic Carbon Stocks in Arctic Deltaic Sediments: Investigations in the Lena River Delta.

    Science.gov (United States)

    Zubrzycki, S.; Kutzbach, L.; Desyatkin, A.; Pfeiffer, E.-M.

    2012-04-01

    The soil organic carbon stock (SSOC) of deltaic sediments in arctic permafrost regions is known to be significant but is insufficiently investigated so far. Previous SSOC studies were conducted mainly in the comparatively well studied Mackenzie River Delta (area: 13,000 km2) in Canada. The few studies from other arctic delta regions report only the gravimetric carbon (C) contents and are limited to the active layer depth at the time of sampling. Since C deposits in permafrost regions are likely to become a future C source, more detailed investigations of the presently frozen likely carbon-rich sediment and soil layers in other arctic delta regions are of importance. Our investigations were performed on Samoylov Island in the southern-central part of the Lena River Delta (32,000 km2) which is the largest arctic delta and the fifth largest delta worldwide. Samoylov Island is representative for the Lena River Delta's first terrace and the active floodplains. Within this study a new portable Snow-Ice-Permafrost-Research-Establishment (SIPRE) auger was used during a spring field session to obtain 1 m deep frozen soil cores (n = 37) distributed over all known soil and vegetation units. These cores are analyzed for bulk contents of nitrogen (N) and C, ice content and bulk density (BD) and to determine the SSOC including the rarely investigated currently permanently frozen layers up to 1 m depth on Samoylov Island. Our study provides evidence for high SSOC for a depth of 1 m for the investigated area ranging between 6 kg m2 and 54 kg m2. Considering the spatial extent of different soil units on the two geomorphological units of Samoylov Island, the area-weighted average SSOC were 31 kg m2 (n = 31) for the first terrace and 15 kg m2 (n = 6) for the active floodplain. For the correspondent soil units of Turbels and Orthels in circumpolar permafrost regions, Tarnocai et al. 2009 reported a mean SSOC of 27 kg m2 (min: 0.1 kg m2, max: 126 kg m2) for a depth of 1 m. For up

  12. Thermoelectric material including a multiple transition metal-doped type I clathrate crystal structure

    Science.gov (United States)

    Yang, Jihui [Lakeshore, CA; Shi, Xun [Troy, MI; Bai, Shengqiang [Shanghai, CN; Zhang, Wenqing [Shanghai, CN; Chen, Lidong [Shanghai, CN; Yang, Jiong [Shanghai, CN

    2012-01-17

    A thermoelectric material includes a multiple transition metal-doped type I clathrate crystal structure having the formula A.sub.8TM.sub.y.sub.1.sup.1TM.sub.y.sub.2.sup.2 . . . TM.sub.y.sub.n.sup.nM.sub.zX.sub.46-y.sub.1.sub.-y.sub.2.sub.- . . . -y.sub.n.sub.-z. In the formula, A is selected from the group consisting of barium, strontium, and europium; X is selected from the group consisting of silicon, germanium, and tin; M is selected from the group consisting of aluminum, gallium, and indium; TM.sup.1, TM.sup.2, and TM.sup.n are independently selected from the group consisting of 3d, 4d, and 5d transition metals; and y.sub.1, y.sub.2, y.sub.n and Z are actual compositions of TM.sup.1, TM.sup.2, TM.sup.n, and M, respectively. The actual compositions are based upon nominal compositions derived from the following equation: z=8q.sub.A-|.DELTA.q.sub.1|y.sub.1-|.DELTA.q.sub.2|y.sub.2- . . . -|.DELTA.q.sub.n|y.sub.n, wherein q.sub.A is a charge state of A, and wherein .DELTA.q.sub.1, .DELTA.q.sub.2, .DELTA.q.sub.n are, respectively, the nominal charge state of the first, second, and n-th TM.

  13. HIV/AIDS, artisanal fishing and food security in the Okavango Delta, Botswana

    Science.gov (United States)

    Ngwenya, B. N.; Mosepele, K.

    Generally, rural households pursue all year round natural and non-natural resource-based livelihood systems to diversify these options in order to cope with risks emanating from a range of shocks and stressors. Artisanal fishing in the Delta is not only a major livelihood option but also a source of food security. This paper is based on analysis of primary data collected from a survey of 248 subsistence fishers’ households through simple random sampling in 22 villages in the Delta. The overall objectives of the survey were to assess the general prevalence of HIV/AIDS in the Ngamiland district of Botswana, to investigate potential effects of AIDS-related stressors, particularly chronic illness on artisanal fishing activities, and to assess implications towards food security. Results from this study indicate that HIV prevalence rates for pregnant women attending antenatal clinics in the Delta are approximately 30% and are related to factors such as marriage, education, and employment. Despite this relatively high prevalence percentage, most of the affected households do not have adequate access to HIV/AIDS support facilities. Support services are provided on the basis of population size and/or status of the settlement (i.e. urban, urban village, rural or remote). Therefore, since about 50% of the Delta’s population lives in settlements of less than 500 people, they receive health services indirectly through major population centres whose capacity to deliver timely HIV/AIDS services is limited. This disproportionate access to HIV/AIDS services disadvantages the majority of fishing communities in the Delta, and may affect their ability to fish. Moreover, about 53% of sampled households had cared for a continuously ill person/s (CIP’s) in the last 5 years, out of which approximately 29% felt that this seriously impacted fishing activities. These serious impacts included sale of family assets, depletion of savings, and switching or abandoning fishing activities

  14. River, delta and coastal morphological response accounting for biological dynamics

    Directory of Open Access Journals (Sweden)

    W. Goldsmith

    2015-03-01

    Full Text Available Management and construction can increase resilience in the face of climate change, and benefits can be enhanced through integration of biogenic materials including shells and vegetation. Rivers and coastal landforms are dynamic systems that respond to intentional and unintended manipulation of critical factors, often with unforeseen and/or undesirable resulting effects. River management strategies have impacts that include deltas and coastal areas which are increasingly vulnerable to climate change with reference to sea level rise and storm intensity. Whereas conventional assessment and analysis of rivers and coasts has relied on modelling of hydrology, hydraulics and sediment transport, incorporating additional biological factors can offer more comprehensive, beneficial and realistic alternatives. Suitable modelling tools can provide improved decision support. The question has been whether current models can effectively address biological responses with suitable reliability and efficiency. Since morphodynamic evolution exhibits its effects on a large timescale, the choice of mathematical model is not trivial and depends upon the availability of data, as well as the spatial extent, timelines and computation effort desired. The ultimate goal of the work is to set up a conveniently simplified river morphodynamic model, coupled with a biological dynamics plant population model able to predict the long-term evolution of large alluvial river systems managed through bioengineering. This paper presents the first step of the work related to the application of the model accounting for stationary vegetation condition. Sensitivity analysis has been performed on the main hydraulic, sedimentology, and biological parameters. The model has been applied to significant river training in Europe, Asia and North America, and comparative analysis has been used to validate analytical solutions. Data gaps and further areas for investigation are identified.

  15. River, delta and coastal morphological response accounting for biological dynamics

    Science.gov (United States)

    Goldsmith, W.; Bernardi, D.; Schippa, L.

    2015-03-01

    Management and construction can increase resilience in the face of climate change, and benefits can be enhanced through integration of biogenic materials including shells and vegetation. Rivers and coastal landforms are dynamic systems that respond to intentional and unintended manipulation of critical factors, often with unforeseen and/or undesirable resulting effects. River management strategies have impacts that include deltas and coastal areas which are increasingly vulnerable to climate change with reference to sea level rise and storm intensity. Whereas conventional assessment and analysis of rivers and coasts has relied on modelling of hydrology, hydraulics and sediment transport, incorporating additional biological factors can offer more comprehensive, beneficial and realistic alternatives. Suitable modelling tools can provide improved decision support. The question has been whether current models can effectively address biological responses with suitable reliability and efficiency. Since morphodynamic evolution exhibits its effects on a large timescale, the choice of mathematical model is not trivial and depends upon the availability of data, as well as the spatial extent, timelines and computation effort desired. The ultimate goal of the work is to set up a conveniently simplified river morphodynamic model, coupled with a biological dynamics plant population model able to predict the long-term evolution of large alluvial river systems managed through bioengineering. This paper presents the first step of the work related to the application of the model accounting for stationary vegetation condition. Sensitivity analysis has been performed on the main hydraulic, sedimentology, and biological parameters. The model has been applied to significant river training in Europe, Asia and North America, and comparative analysis has been used to validate analytical solutions. Data gaps and further areas for investigation are identified.

  16. Critical Assessment of the Delta Smelt Population in the San Francisco Estuary, California

    Directory of Open Access Journals (Sweden)

    William A Bennett

    2005-09-01

    growth, survival, and reproductive success on an annual basis despite an array of limiting factors that can occur at specific times and locations. Variability in spawning success and larval survival is induced by climate and other environmental and anthropogenic factors that operate between winter and mid-summer. However, spawning microhabitats with egg deposition have not been discovered. Spawning success appears to be timed to lunar periods within a water temperature range of about 15 to 20°C. Longer spawning seasons in cooler years can produce more cohorts and on average higher numbers of adult delta smelt. Cohorts spaced in time have different probabilities of encountering various sources of mortality, including entrainment in freshwater export operations, pulses of toxic pesticides, food shortages and predation by exotic species. Density dependence may provide an upper limit on the numbers of juvenile delta smelt surviving to the adult stage. This may occur during late summer in years when juvenile abundance is high relative to habitat carrying capacity. Factors defining the carrying capacity for juvenile delta smelt are unknown, but may include a shrinking volume of physically suitable habitat combined with a high density of competing planktivorous fishes during late summer and fall. Understanding the relative importance of anthropogenic effects on the population can be improved through better estimates of abundance and measurements of potentially limiting processes. There is little information on losses of larval delta smelt (less than 20 mm fork length, FL to the export facilities. Use of a population model suggests that water export operations can impact the abundance of post-larval (about 20 mm FL delta smelt, but these effects may not reflect on adult abundance due to other processes operating in the intervening period. Effects from changes to the estuarine food web by exotic species and toxic chemicals occur but measuring their influence on population

  17. Oxygen Nonstoichiometry and Defect Chemistry Modeling of Ce0.8Pr0.2O2-delta

    DEFF Research Database (Denmark)

    Chatzichristodoulou, Christodoulos; Hendriksen, Peter Vang

    2010-01-01

    (DeltaHPrexc=aHdelta) and a completely random distribution of defects (referred to as “delta-linear”), or a “generalized delta-linear” solution model, where the excess Gibbs energy change in the reduction reaction of the dopant linearly varies with delta (DeltaGPrexc=aGdelta). A comparison of the partial...

  18. Flipped SU(5) predicts {delta}T/T

    Energy Technology Data Exchange (ETDEWEB)

    Kyae, Bumseok [School of Physics, Korea Institute for Advanced Study, 207-43, Cheongnyangni-Dong, Dongdaemun-Gu, Seoul 130-722 (Korea, Republic of)]. E-mail: bkyae@kias.re.kr; Shafi, Qaisar [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)]. E-mail: shafi@bartol.udel.edu

    2006-04-20

    We discuss hybrid inflation in supersymmetric flipped SU(5) model such that the cosmic microwave anisotropy {delta}T/T is essentially proportional to (M/M{sub P}){sup 2}, where M denotes the symmetry breaking scale and M{sub P} (=2.4x10{sup 18} GeV) is the reduced Planck mass. The magnitude of M determined from {delta}T/T measurements can be consistent with the value inferred from the evolution of SU(3) and SU(2) gauge couplings. In other words, one could state that flipped SU(5) predicts (more precisely 'postdicts') {delta}T/T. The scalar spectral index n{sub s}=0.993+/-0.007, the scalar to tensor ratio satisfies r-bar 10{sup -6}, while dn{sub s}/dlnk-bar 4x10{sup -4}.

  19. Fracture Analyses of Cracked Delta Eye Plates in Ship Towing

    Science.gov (United States)

    Huang, Xiangbing; Huang, Xingling; Sun, Jizheng

    2018-01-01

    Based on fracture mechanics, a safety analysis approach is proposed for cracked delta eye plates in ship towing. The static analysis model is presented when the delta eye plate is in service, and the fracture criterion is introduced on basis of stress intensity factor, which is estimated with domain integral method. Subsequently, three-dimensional finite element analyses are carried out to obtain the effective stress intensity factors, and a case is studied to demonstrate the reasonability of the approach. The results show that the classical strength theory is not applicable to evaluate the cracked plate while fracture mechanics can solve the problem very well, and the load level, which a delta eye plate can carry on, decreases evidently when it is damaged.

  20. Cystic fibrosis Delta F508 heterozygotes, smoking, and reproduction

    DEFF Research Database (Denmark)

    Dahl, Morten; Tybjaerg-Hansen, A; Wittrup, H H

    1998-01-01

    Cystic fibrosis is the most common fatal autosomal recessive disease affecting Caucasian populations. It remains a puzzle how this disease is maintained at such a remarkably high incidence, however, it could be due to a reproductive advantage in cystic fibrosis heterozygotes. We tested this hypot......Cystic fibrosis is the most common fatal autosomal recessive disease affecting Caucasian populations. It remains a puzzle how this disease is maintained at such a remarkably high incidence, however, it could be due to a reproductive advantage in cystic fibrosis heterozygotes. We tested.......001). In conclusion, overall these results do not support a reproductive advantage for cystic fibrosis DeltaF508 heterozygotes. However, the data cannot totally exclude the possibility that nonsmoking DeltaF508 heterozygotes experience a reproductive advantage while smoking DeltaF508 heterozygotes experience...... the opposite, a reproductive disadvantage. Accordingly, the data suggest a previously undocumented role of smoking on fecundity among cystic fibrosis heterozygotes....

  1. Implementation of an ESA delta-DOR capability

    Science.gov (United States)

    James, Nick; Abello, Ricard; Lanucara, Marco; Mercolino, Mattia; Maddè, Roberto

    2009-06-01

    This paper describes the implementation of delta-DOR (delta-differential one-way ranging) receivers within the ESA Deep Space ground station network. Delta-DOR provides very accurate plane-of-sky measurements of spacecraft position which complement existing line-of-sight ranging and Doppler measurements. We discuss how this technique has been adapted and implemented at the two ESA deep-space ground stations using existing equipment and infrastructure. These new capabilities were added by writing new software modules for the standard ESA digital receiver (the intermediate frequency modem system—IFMS). With these upgrades the receiver has the ability to record accurately timetagged signals from up to eight IF sub-channels. These sub-channels can have bandwidths of 50 kHz-2 MHz with a sample quantization of 1-16 bits per component. The IF samples are stored locally for subsequent retrieval over a WAN by the correlator facility at ESOC.

  2. Parametrization of the. delta. residue function. [Complex functions

    Energy Technology Data Exchange (ETDEWEB)

    Vasan, S S [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

    1976-04-19

    The complex residues at the ..delta..(1236) and ..delta..(1950) poles in the relevant partial-wave amplitudes provide information on the behaviour of the ..delta.. Regge residue function in the resonance region u>0. Attempts to incorporate this information in parametrizations of the residue by functions that are real on the real u-axis result in residues which have unsatisfactory behaviour in the region u<1GeV/sup 2/. The choice of complex functions for the trajectory and residue removes this undesirable feature and provides a better representation of the residue in the resonance region, suggesting that complex parametrizations would be better suited to Regge analyses of near-backward scattering.

  3. [Transport characteristics of air pollutants over the Yangtze Delta].

    Science.gov (United States)

    Wang, Yan; Chai, Fa-He; Wang, Yong-Hong; Liu, Ming

    2008-05-01

    Meteorological field of January, April, July and October in 2004 was obtained by running MM5 with NCEP datasets. Then we used HYSPLIT 4.8 model to calculate the backward and forward trajectories of representative cities. Distributions of trajectories and the affected areas vary with seasons. Transport current affecting Yangtze River Delta is mainly from Mongolia, North China or Northeast region, via Yellow Sea area, Shandong, Jiangsu province or Shanghai. Another important transport path is current from southwest because of the Southwest monsoon. A movement of East Asia monsoon plays an important part in the mesoscale transport of pollutants in Yangtze Delta. Winter monsoon is a main mechanism which moves the air pollutants in Yangtze Delta to South China and West Pacific ocean. Another important transport system is the subtropical anticyclone over the western Pacific Ocean which controls the east coast of our country in spring and summer. This circulation system mainly affects the inland area of our country.

  4. Dendroclimatology of the Slave River Delta, Northwest Territories, Canada

    Science.gov (United States)

    Jarvis, S.; Buhay, W. M.; Blair, D.; Tardif, J.; Bailey, D.

    2004-05-01

    It is well documented that changing hydrological conditions impact delta ecosystems. Such changes can also affect local inhabitants who have historical connections to the area and its resources. During the summer of 2003 a multifaceted paleo-environmental project was initiated to reconstruct the frequencies of floods and droughts in the Slave River Delta (SRD), Northwest Territories, Canada. The project goal is to forecast future hydrological and ecological conditions in the SRD in light of anticipated climate change and increasing demand on water resources. With the intent of expanding the climate history of the SRD, this particular aspect of the project will employ white spruce tree-ring chronologies constructed from six sites visited within the delta. Work is currently in progress to build a master chronology estimated to span over 300 years. In addition, a climate model for the SRD is also being developed and will be highlighted.

  5. Dynamic controls on shallow clinoform geometry: Mekong Delta, Vietnam

    Science.gov (United States)

    Eidam, E. F.; Nittrouer, C. A.; Ogston, A. S.; DeMaster, D. J.; Liu, J. P.; Nguyen, T. T.; Nguyen, T. N.

    2017-09-01

    Compound deltas, composed of a subaerial delta plain and subaqueous clinoform, are common termini of large rivers. The transition between clinoform topset and foreset, or subaqueous rollover point, is located at 25-40-m water depth for many large tide-dominated deltas; this depth is controlled by removal of sediment from the topset by waves, currents, and gravity flows. However, the Mekong Delta, which has been classified as a mixed-energy system, has a relatively shallow subaqueous rollover at 4-6-m depth. This study evaluates dynamical measurements and seabed cores collected in Sep 2014 and Mar 2015 to understand processes of sediment transfer across the subaqueous delta, and evaluate possible linkages to geometry. During the southwest rainy monsoon (Sep 2014), high river discharge, landward return flow under the river plume, and regional circulation patterns facilitated limited sediment flux to the topset and foreset, and promoted alongshore flux to the northeast. Net observed sediment fluxes in Sep 2014 were landward, however, consistent with hypotheses about seasonal storage on the topset. During the northeast rainy monsoon, low river discharge and wind-driven currents facilitated intense landward and southwestward fluxes of sediment. In both seasons, bed shear velocities frequently exceeded the 0.01-0.02 m/s threshold of motion for sand, even in the absence of strong wave energy. Most sediment transport occurred at water depths 4 cm/yr at energy-limited, and thus rollover depths cannot be predicted solely by bed-stress distributions. In systems like the subaqueous Mekong Delta, direction of transport may have a key impact on morphology.

  6. Structure of the [delta]-opioid receptor bound to naltrindole

    Energy Technology Data Exchange (ETDEWEB)

    Granier, Sébastien; Manglik, Aashish; Kruse, Andrew C.; Kobilka, Tong Sun; Thian, Foon Sun; Weis, William I.; Kobilka, Brian K. (Stanford-MED)

    2012-07-11

    The opioid receptor family comprises three members, the {mu}-, {delta}- and {kappa}-opioid receptors, which respond to classical opioid alkaloids such as morphine and heroin as well as to endogenous peptide ligands like endorphins. They belong to the G-protein-coupled receptor (GPCR) superfamily, and are excellent therapeutic targets for pain control. The {delta}-opioid receptor ({delta}-OR) has a role in analgesia, as well as in other neurological functions that remain poorly understood. The structures of the {mu}-OR and {kappa}-OR have recently been solved. Here we report the crystal structure of the mouse {delta}-OR, bound to the subtype-selective antagonist naltrindole. Together with the structures of the {mu}-OR and {kappa}-OR, the {delta}-OR structure provides insights into conserved elements of opioid ligand recognition while also revealing structural features associated with ligand-subtype selectivity. The binding pocket of opioid receptors can be divided into two distinct regions. Whereas the lower part of this pocket is highly conserved among opioid receptors, the upper part contains divergent residues that confer subtype selectivity. This provides a structural explanation and validation for the 'message-address' model of opioid receptor pharmacology, in which distinct 'message' (efficacy) and 'address' (selectivity) determinants are contained within a single ligand. Comparison of the address region of the {delta}-OR with other GPCRs reveals that this structural organization may be a more general phenomenon, extending to other GPCR families as well.

  7. Salinity Impacts on Agriculture and Groundwater in Delta Regions

    Science.gov (United States)

    Clarke, D.; Salehin, M.; Jairuddin, M.; Saleh, A. F. M.; Rahman, M. M.; Parks, K. E.; Haque, M. A.; Lázár, A. N.; Payo, A.

    2015-12-01

    Delta regions are attractive for high intensity agriculture due to the availability of rich sedimentary soils and of fresh water. Many of the world's tropical deltas support high population densities which are reliant on irrigated agriculture. However environmental changes such as sea level rise, tidal inundation and reduced river flows have reduced the quantity and quality of water available for successful agriculture. Additionally, anthropogenic influences such as the over abstraction of ground water and the increased use of low quality water from river inlets has resulted in the accumulation of salts in the soils which diminishes crop productivity. Communities based in these regions are usually reliant on the same water for drinking and cooking because surface water is frequently contaminated by commercial and urban pollution. The expansion of shallow tube well systems for drinking water and agricultural use over the last few decades has resulted in mobilisation of salinity in the coastal and estuarine fringes. Sustainable development in delta regions is becoming constrained by water salinity. However salinity is often studied as an independent issue by specialists working in the fields of agriculture, community water supply and groundwater. The lack of interaction between these disciplines often results in corrective actions being applied to one sector without fully assessing the effects of these actions on other sectors. This paper describes a framework for indentifying the causes and impacts of salinity in delta regions based on the source-pathway-receptor framework. It uses examples and scenarios from the Ganges-Brahmaputra-Meghna delta in Bangladesh together with field measurements and observations made in vulnerable coastal communities. The paper demonstrates the importance of creating an holistic understanding of the development and management of water resources to reduce the impact of salinity in fresh water in delta regions.

  8. DNA repair synthesis in human fibroblasts requires DNA polymerase delta

    International Nuclear Information System (INIS)

    Nishida, C.; Reinhard, P.; Linn, S.

    1988-01-01

    When UV-irradiated cultured diploid human fibroblasts were permeabilized with Brij-58 then separated from soluble material by centrifugation, conservative DNA repair synthesis could be restored by a soluble factor obtained from the supernatant of similarly treated HeLa cells. Extensive purification of this factor yielded a 10.2 S, 220,000-dalton polypeptide with the DNA polymerase and 3'- to 5'-exonuclease activities reported for DNA polymerase delta II. Monoclonal antibody to KB cell DNA polymerase alpha, while binding to HeLa DNA polymerase alpha, did not bind to the HeLa DNA polymerase delta. Moreover, at micromolar concentrations N2-(p-n-butylphenyl)-2'-deoxyguanosine 5'-triphosphate (BuPdGTP) and 2-(p-n-butylanilino)-2'-deoxyadenosine 5'-triphosphate (BuAdATP) were potent inhibitors of DNA polymerase alpha, but did not inhibit the DNA polymerase delta. Neither purified DNA polymerase alpha nor beta could promote repair DNA synthesis in the permeabilized cells. Furthermore, under conditions which inhibited purified DNA polymerase alpha by greater than 90%, neither monoclonal antibodies to DNA polymerase alpha, BuPdGTP, nor BuAdATP was able to inhibit significantly the DNA repair synthesis mediated by the DNA polymerase delta. Thus, it appears that a major portion of DNA repair synthesis induced by UV irradiation might be catalyzed by DNA polymerase delta. When xeroderma pigmentosum human diploid fibroblasts were utilized, DNA repair synthesis dependent upon ultraviolet light could be restored by addition of both T4 endonuclease V and DNA polymerase delta, but not by addition of either one alone

  9. Delta progradation in Greenland driven by increasing glacial mass loss

    DEFF Research Database (Denmark)

    Bendixen, Mette; Iversen, Lars Lonsmann; Bjork, Anders Anker

    2017-01-01

    imagery. We find that delta progradation was driven by high freshwater runoff from the Greenland Ice Sheet coinciding with periods of open water. Progradation was controlled by the local initial environmental conditions (that is, accumulated air temperatures above 0 degrees C per year, freshwater runoff...... of erosion and accretion along the large deltas of the main rivers in the Arctic5-7. Our results improve the understanding of Arctic coastal evolution in a changing climate, and reveal the impacts on coastal areas of increasing ice mass loss and the associated freshwater runoff and lengthening of open-water...

  10. A divergent synthesis of the delta(13)-9-isofurans.

    Science.gov (United States)

    Taber, Douglass F; Gu, Peiming; Li, Rui

    2009-08-07

    A stereodivergent total synthesis of the Delta(13)-9-isofurans has been developed. The four core substituted tetrahydrofurans were prepared by the Sharpless asymmetric epoxidation and Sharpless asymmetric dihydroxylation followed by cascade cyclization. The relative configuration at C-8 was inverted by oxidation followed by immediate L-Selectride reduction. The relative configuration of the C-15 diastereomers was assigned by (S)-Binol/LAH/EtOH reduction of the corresponding enone. This synthesis of the Delta(13)-9-isofurans will provide sufficient material for further investigation of their biological activity.

  11. Halotolerance of Methanobacterium thermoautotrophicum delta H and Marburg.

    OpenAIRE

    Ciulla, R; Clougherty, C; Belay, N; Krishnan, S; Zhou, C; Byrd, D; Roberts, M F

    1994-01-01

    Methanobacterium thermoautotrophicum delta H and Marburg were adapted to grow in medium containing up to 0.65 M NaCl. From 0.01 to 0.5 M NaCl, there was a lag before cell growth which increased with increasing external NaCl. The effect of NaCl on methane production was not significant once the cells began to grow. Intracellular solutes were monitored by nuclear magnetic resonance (NMR) spectroscopy as a function of osmotic stress. In the delta H strain, the major intracellular small organic s...

  12. Changing Course - the Baird Team Solution: a Delta for All

    Science.gov (United States)

    Nairn, R. B.

    2016-02-01

    The Changing Course Design competition was initiated to evaluate options for re-positioning the mouth of the Mississippi River and modifying the management of the Lower Mississippi River to support the 2017 Master Plan for the Louisiana coast. This paper will present the findings of one of the selected competitors: the Baird Team and their "Delta for All" approach. A key to success in the future management of the lower Mississippi River is the development of an integrated, holistic approach to management that recognizes the need to harness the full land/wetland building and restorative potential of the river at the same time as improving flood protection and navigation. Fundamentally the Baird solution recognized the underlying geomorphic challenges of the Delta: it receives three to four times less sediment from the Mississippi River than it did historically and sea level is rising two to three times faster than it did historically and is predicted to rise much faster in the future. The result will be a smaller delta in the future. Our approach seeks to harness as close to 100% of the land building potential of the river to make the smaller future delta as large as possible. This compares to the 2012 State Master Plan which would harness approximately 50% of the land-building potential. Our approach also recognizes that the further inland new distributary mouths and associated sub-deltas are located, the greater the delta building potential. Our approach builds with the river by creating and managing new river distributaries that are opened and closed every 50 years or so to build new sub-deltas within a defined sustainable delta footprint. By placing the last outlet somewhere in the vicinity of English Turn the lower Mississippi River would become a tidal channel. These two simple concepts of harnessing 100% of the river and placing the last outlet near English Turn result in immediate and significant benefits for flood protection and navigation. Through the

  13. Mazda kiintotyövaiheiden perustaminen : Delta Auto Oy

    OpenAIRE

    Schreck, Ville

    2012-01-01

    Täyden palvelun autoliikeketju Delta Auto myy ja huoltaa Kia-, Mitsubishi- ja Mazda-merkkisiä autoja paikkakuntakohtaisesti kahdessakymmenessäviidessä toimipisteessä. Opinnäytetyön tarkoituksena oli tehdä toimiva ratkaisu Mazdan työvaiheiden sekä työpakettien myyntiin Automaster-ohjelmistoon. Työvaiheet sekä ohjeajat tulevat käyttöön kaikkiin Delta Auton toimipisteisiin ympäri Suomea. Työn lähdemateriaalin sain Inchcape Motor Finland Oy:ltä, joka toimii Suomessa Mazdan maahantuojana. Tarve tä...

  14. CMOS sigma-delta converters practical design guide

    CERN Document Server

    De la Rosa, Jose M

    2013-01-01

    A comprehensive overview of Sigma-Delta Analog-to-Digital Converters (ADCs) and a practical guide to their design in nano-scale CMOS for optimal performance. This book presents a systematic and comprehensive compilation of sigma-delta converter operating principles, the new advances in architectures and circuits, design methodologies and practical considerations - going from system-level specifications to silicon integration, packaging and measurements, with emphasis on nanometer CMOS implementation. The book emphasizes practical design issues - from high-level behavioural modelling i

  15. Measurement of $\\Delta^{++}$(1232) production in hadronic Z decays

    CERN Document Server

    Abreu, P; Adye, T; Agasi, E; Ajinenko, I; Aleksan, Roy; Alekseev, G D; Allport, P P; Almehed, S; Alvsvaag, S J; Amaldi, Ugo; Amato, S; Andreazza, A; Andrieux, M L; Antilogus, P; Anykeyev, V B; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barate, R; Bardin, Dimitri Yuri; Barker, G J; Baroncelli, A; Bärring, O; Barrio, J A; Bartl, Walter; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Benvenuti, Alberto C; Berggren, M; Bertrand, D; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bloch, D; Blume, M; Blyth, S; Bocci, V; Bolognese, T; Bonesini, M; Bonivento, W; Booth, P S L; Borisov, G; Bosio, C; Bosworth, S; Botner, O; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenke, T; Brenner, R A; Bricman, C; Brillault, L; Brown, R C A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Buys, A; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cankocak, K; Cao, F; Carena, F; Carrilho, P; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Cerrito, L; Chabaud, V; Charpentier, P; Chaussard, L; Chauveau, J; Checchia, P; Chelkov, G A; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Cindro, V; Collins, P; Contreras, J L; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Dahl-Jensen, Erik; Dahm, J; D'Almagne, B; Dam, M; Damgaard, G; Daum, A; Dauncey, P D; Davenport, Martyn; Da Silva, W; Defoix, C; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; De Boeck, H; de Boer, Wim; De Brabandere, S; De Clercq, C; La Vaissière, C de; De Lotto, B; De Min, A; De Paula, L S; De Saint-Jean, C; Dijkstra, H; Di Ciaccio, Lucia; Djama, F; Dolbeau, J; Dönszelmann, M; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Dufour, Y; Dupont, F; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Ershaidat, N; Erzen, B; Espirito-Santo, M C; Falk, E; Fassouliotis, D; Feindt, Michael; Ferrer, A; Filippas-Tassos, A; Firestone, A; Fischer, P A; Föth, H; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frenkiel, P; Fries, D E C; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gibbs, M; Gokieli, R; Golob, B; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Graziani, E; Grosdidier, G; Gunnarsson, P; Günther, M; Guy, J; Haedinger, U; Hahn, F; Hahn, M; Hahn, S; Hajduk, Z; Hallgren, A; Hamacher, K; Hao, W; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Higón, E; Hilke, Hans Jürgen; Hill, T S; Holmgren, S O; Holt, P J; Holthuizen, D J; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Ioannou, P; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, L B; Jönsson, P E; Joram, Christian; Juillot, P; Kaiser, M; Kapusta, F; Karlsson, M; Karvelas, E; Katsanevas, S; Katsoufis, E C; Keränen, R; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klein, H; Klovning, A; Kluit, P M; Köhne, J H; Köne, B; Kokkinias, P; Koratzinos, M; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Kramer, P H; Krammer, Manfred; Kreuter, C; Królikowski, J; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lacasta, C; Laktineh, I; Lamblot, S; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Lapin, V; Last, I; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leitner, R; Lemoigne, Y; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lörstad, B; Lokajícek, M; Loken, J G; López, J M; López-Fernandez, A; López-Aguera, M A; Loukas, D; Lutz, P; Lyons, L; Maehlum, G; Maio, A; Malychev, V; Mandl, F; Marco, J; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Maron, T; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Meroni, C; Meyer, W T; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Morettini, P; Müller, H; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Negri, P; Némécek, S; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Niss, P; Nomerotski, A; Normand, Ainsley; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Österberg, K; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Palka, H; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Passeri, A; Pegoraro, M; Pernegger, H; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Pindo, M; Plaszczynski, S; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Prest, M; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rames, J; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rídky, J; Rinaudo, G; Ripp, I; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Rosso, E; Roudeau, Patrick; Rovelli, T; Rückstuhl, W; Ruhlmann-Kleider, V; Ruiz, A; Rybicki, K; Rybin, A; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sánchez, J; Sannino, M; Schneider, H; Schyns, M A E; Sciolla, G; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Shellard, R C; Siccama, I; Siegrist, P; Simonetti, S; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnova, O G; Smith, G R; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stanescu, C; Stapnes, Steinar; Stavitski, I; Stepaniak, K; Stichelbaut, F; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tavernet, J P; Chikilev, O G; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Toet, D Z; Tomaradze, A G; Tomé, B; Tortora, L; Tranströmer, G; Treille, D; Trischuk, W; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van der Velde, C; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Waldner, F; Weierstall, M; Weilhammer, Peter; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Woschnagg, K; Yip, K; Yushchenko, O P; Zach, F; Zacharatou-Jarlskog, C; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zhigunov, V P; Zimin, N I; Zito, M; Zontar, D; Zuberi, R; Zucchelli, G C; Zumerle, G

    1995-01-01

    A measurement of the \\Delta^{++}(1232) inclusive production in hadronic decays of the Z at LEP is presented, based on 1.3 million hadronic events collected~ by the DELPHI~ detector in the 1994 LEP running~ period. The DELPHI ring imaging Cherenkov counters are used for identifying hadrons. The average \\Delta^{++}(1232) multiplicity per hadronic event is 0.079 \\pm 0.015 which is more than a factor of two below the JETSET, HERWIG and UCLA model predictions. It agrees with a recently proposed universal mass dependence of particle production rates in e^{+}e^- annihilations.

  16. Water and nitrogen conditions affect the relationships of Delta13C and Delta18O to gas exchange and growth in durum wheat.

    Science.gov (United States)

    Cabrera-Bosquet, Llorenç; Molero, Gemma; Nogués, Salvador; Araus, José Luis

    2009-01-01

    Whereas the effects of water and nitrogen (N) on plant Delta(13)C have been reported previously, these factors have scarcely been studied for Delta(18)O. Here the combined effect of different water and N regimes on Delta(13)C, Delta(18)O, gas exchange, water-use efficiency (WUE), and growth of four genotypes of durum wheat [Triticum turgidum L. ssp. durum (Desf.) Husn.] cultured in pots was studied. Water and N supply significantly increased plant growth. However, a reduction in water supply did not lead to a significant decrease in gas exchange parameters, and consequently Delta(13)C was only slightly modified by water input. Conversely, N fertilizer significantly decreased Delta(13)C. On the other hand, water supply decreased Delta(18)O values, whereas N did not affect this parameter. Delta(18)O variation was mainly determined by the amount of transpired water throughout plant growth (T(cum)), whereas Delta(13)C variation was explained in part by a combination of leaf N and stomatal conductance (g(s)). Even though the four genotypes showed significant differences in cumulative transpiration rates and biomass, this was not translated into significant differences in Delta(18)O(s). However, genotypic differences in Delta(13)C were observed. Moreover, approximately 80% of the variation in biomass across growing conditions and genotypes was explained by a combination of both isotopes, with Delta(18)O alone accounting for approximately 50%. This illustrates the usefulness of combining Delta(18)O and Delta(13)C in order to assess differences in plant growth and total transpiration, and also to provide a time-integrated record of the photosynthetic and evaporative performance of the plant during the course of crop growth.

  17. Stimulation of accumbal GABAA receptors inhibits delta2-, but not delta1-, opioid receptor-mediated dopamine efflux in the nucleus accumbens of freely moving rats.

    Science.gov (United States)

    Aono, Yuri; Kiguchi, Yuri; Watanabe, Yuriko; Waddington, John L; Saigusa, Tadashi

    2017-11-15

    The nucleus accumbens contains delta-opioid receptors that may reduce inhibitory neurotransmission. Reduction in GABA A receptor-mediated inhibition of accumbal dopamine release due to delta-opioid receptor activation should be suppressed by stimulating accumbal GABA A receptors. As delta-opioid receptors are divided into delta2- and delta1-opioid receptors, we analysed the effects of the GABA A receptor agonist muscimol on delta2- and delta1-opioid receptor-mediated accumbal dopamine efflux in freely moving rats using in vivo microdialysis. Drugs were administered intracerebrally through the dialysis probe. Doses of compounds indicate total amount administered (mol) during 25-50min infusions. The delta2-opioid receptor agonist deltorphin II (25.0nmol)- and delta1-opioid receptor agonist DPDPE (5.0nmol)-induced increases in dopamine efflux were inhibited by the delta2-opioid receptor antagonist naltriben (1.5nmol) and the delta1-opioid receptor antagonist BNTX (150.0pmol), respectively. Muscimol (250.0pmol) inhibited deltorphin II (25.0nmol)-induced dopamine efflux. The GABA A receptor antagonist bicuculline (50.0pmol), which failed to affect deltorphin II (25.0nmol)-induced dopamine efflux, counteracted the inhibitory effect of muscimol on deltorphin II-induced dopamine efflux. Neither muscimol (250.0pmol) nor bicuculline (50.0 and 500.0pmol) altered DPDPE (5.0nmol)-induced dopamine efflux. The present results show that reduction in accumbal GABA A receptor-mediated inhibition of dopaminergic activity is necessary to produce delta2-opioid receptor-induced increase in accumbal dopamine efflux. This study indicates that activation of delta2- but not delta1-opioid receptors on the cell bodies and/or terminals of accumbal GABAergic interneurons inhibits GABA release and, accordingly, decreases GABA A receptor-mediated inhibition of dopaminergic terminals, resulting in enhanced accumbal dopamine efflux. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. InSAR-based detection of McKenzie River Delta Permafrost loss

    Science.gov (United States)

    Oliver-Cabrera, T.; Wdowinski, S.

    2017-12-01

    Permafrost underlies most of the McKenzie River, North America's largest delta. The in the delta is catalogued as discontinuous permafrost due to the influence of shifting river channels on near-surface ground temperatures. The area is affected by climate change, studies show that ground temperature has increased by 1.5°C since 1970, due to rising annual mean air temperature. Flooding regimes within the delta are also affected by the changing climate due to melting of near surface ground ice together with sea-level rise increasing the potential of land subsidence. Observed consequences of changes occurring in the region are vegetation growth and northward migration of the tree line. The growing vegetation can affect physical properties of the accumulated snow, including depth, density and thermal conductivity. Thogether these variations affect permafrost stability. Permafrost changes can be measured throughout the impacts on river runoffs, ground water, drainages, carbon release, land subsidence and even infrastructure damages. Degradation of permafrost can also be measured by observing ecological changes in the area. In this study, we use InSAR observations to detect permafrost changes and their transition to wetland or vegetated land cover. Our data consist of four ALOS-PALSAR frames covering the entire McKenzie River Delta with temporal coverage spanning from January 2007 to March of 2011. Each frame has 20 to 24 acquisitions, in which half of the data acquired with HH polarization and the other half with HH+HV. We process the data using ROI_PAC and PYSAR software packages. Preliminary results have detected the following spatial patterns: (1) An overall good coherence of summer interferograms with 46-92 day interferograms, (2) Low coherence of winter interferograms (November to February), probably to the increase in snow coverage, (3) Phase jumps along the border of the river reflecting morphological differences between the region near to the river and other

  19. A Regional Survey of River-plume Sedimentation on the Mississippi River Delta Front

    Science.gov (United States)

    Courtois, A. J.; Bentley, S. J.; Xu, K.; Georgiou, I. Y.; Maloney, J. M.; Miner, M. D.; Chaytor, J. D.; Smith, J.

    2017-12-01

    Many studies of the Mississippi River and Delta (MRD) have shown historic declines in sediment load reaching the main river distributaries over the last few decades. Recent studies also reported that 50% of the suspended load during floods is sequestered within the delta. While the impact of declining sediment load on wetland loss is well documented, submarine sedimentary processes on the delta front during this recent period of declining sediment load are understudied. To better understand modern sediment dispersal and deposition across the Mississippi River Delta Front, 31 multicores were collected in June 2017 from locations extending offshore from Southwest Pass, South Pass, and Pass a Loutre (the main river outlets) in water depths of 25-280 m. Core locations were selected based on multibeam bathymetry and morphology collected by the USGS in May 2017; the timing of collection coincided with the end of annual peak discharge on the Mississippi River. This multi-agency survey is the first to study delta-front sedimentary processes regionally with such a wide suite of tools. Target locations for coring included the dominant depositional environments: mudflow lobes, gullies, and undisturbed prodelta. Cores were subsampled at 2 cm intervals and analyzed for Beryllium-7 activity via gamma spectrometry; in such settings, Be-7 can be used as a tracer of sediment recently delivered from fluvial origin. Results indicate a general trend of declining Be-7 activity with increasing distance from source, and in deeper water. Inshore samples near Southwest Pass show the deepest penetration depth of Be-7 into the sediment (24-26 cm), which is a preliminary indicator of rapid seasonal sedimentation. Nearshore samples from South Pass exhibited similar Be-7 penetration depths, with results near Pass a Loutre to 14-16 cm depth. Be-7 remains detectable to 2 cm in water 206 m deep, approximately 20 km from South Pass. Sediment dispersal remains impressive offshore from all three

  20. Shallow stratigraphy of the Skagit River Delta, Washington, derived from sediment cores

    Science.gov (United States)

    Grossman, Eric E.; George, Douglas A.; Lam, Angela

    2011-01-01

    Sedimentologic analyses of 21 sediment cores, ranging from 0.4 to 9.6 m in length, reveal that the shallow geologic framework of the Skagit River Delta, western Washington, United States, has changed significantly since 1850. The cores collected from elevations of 3.94 to -2.41 m (relative to mean lower low water) along four cross-shore transects between the emergent marsh and delta front show relatively similar environmental changes across an area spanning ~75 km2. Offshore of the present North Fork Skagit River and South Fork Skagit River mouths where river discharge is focused by diked channels through the delta, the entire 5–7-km-wide tidal flats are covered with 1–2 m of cross-bedded medium-to-coarse sands. The bottoms of cores, collected in these areas are composed of mud. A sharp transition from mud to a cross-bedded sand unit indicates that the tidal flats changed abruptly from a calm environment to an energetic one. This is in stark contrast to the Martha's Bay tidal flats north of the Skagit Bay jetty that was completed in the 1940s to protect the newly constructed Swinomish Channel from flooding and sedimentation. North of the jetty, mud ranging from 1 to 2 m thick drapes a previously silt- and sand-rich tidal flat. The silty sand is a sediment facies that would be expected there where North Fork Skagit River sedimentation occurred prior to jetty emplacement. This report describes the compositional and textural properties of the sediment cores by using geophysical, photographic, x-radiography, and standard sediment grain-size and carbon-analytical methods. The findings help to characterize benthic habitat structure and sediment transport processes and the environmental changes that have occurred across the nearshore of the Skagit River Delta. The findings will be useful for quantifying changes to nearshore marine resources, including impacts resulting from diking, river-delta channelization, shoreline development, and natural variations in fluvial

  1. How to deal with subsidence in the Dutch delta?

    Science.gov (United States)

    Stouthamer, Esther; Erkens, Gilles

    2017-04-01

    In many deltas worldwide subsidence still is an underestimated problem, while the threat posed by land subsidence to low-lying urbanizing and urbanized deltas exceeds the threat of sea-level rise induced by climate change. Human-induced subsidence is driven by the extraction of hydrocarbons and groundwater, drainage of phreatic groundwater, and loading by buildings and infrastructure. The consequences of subsidence are increased flood risk and flood water depth, rising groundwater levels relative to the land surface, land loss, damage to buildings and infrastructure, and salinization of ground and surface water.. The Netherlands has a long history of subsidence. Large-scale drainage of the extensive peatlands in the western and northern parts of the Netherlands started approximately 1000 years ago as a result of rapid population growth. Subsidence is still ongoing due to (1) continuous drainage of the former peatland, which is now mainly in use as agricultural land and built-up area, (2) expansion of the built-up area and the infrastructural network, (3) salt mining and the extraction of gas in the northern Netherlands. Mitigating subsidence and its negative impacts requires understanding of the relative contribution of the drivers contributing to total subsidence, accurate predictions of land subsidence under different management scenarios, and its impacts. Such understanding enables the development of effective and sustainable management strategies. In the Netherlands, a lot of effort is put into water management aiming at amongst others the protection against floods and the ensuring agricultural activities, but a specific policy focusing on subsidence is lacking. The development of strategies to cope with subsidence is very challenging, because (1) the exact contribution of different drivers of subsidence to total subsidence is spatially different within the Netherlands, (2) there is no single problem owner, which makes it difficult to recognize this a common

  2. Stable Isotope (delta OXYGEN-18, Delta Deuterium, Delta CARBON-13) Dendroclimatological Studies in the Waterloo Region of Southern Ontario, Canada, Between AD 1610 and 1990.

    Science.gov (United States)

    Buhay, William Mark

    Oxygen (delta^{18} O), hydrogen (delta^2H) and carbon (delta^{13}C) isotopes were measured in wood cellulose from elm, white pine and maple trees that grew in southwestern Ontario, Canada. The measured oxygen and hydrogen isotopic data were used for model-based reconstructions of delta^{18}{O}_{meteoric water}, mean annual temperature (MAT) and relative humidity for a period, AD 1610 to 1880, that precedes instrumental records of climate. The carbon isotope measurements were compared with the Cellulose Model inferred climate data to reveal additional environmental information. Modifications made to the Cellulose Model focused on the dynamics of oxygen and hydrogen isotopic fractionation in plants during evapotranspiration and photosynthetic assimilation. For instance, kinetic fractionation of ^{18}O was found to be predictable from theoretical considerations of leaf energy balance and boundary layer dynamics. Kinetic fractionation during evapotranspiration is sensitive to the nature of the boundary layer, which is controlled by leaf size and morphology. Generally, plants with small segmented leaves have a lower component of turbidity in the leaf boundary layer, which results in higher kinetic fractionation values, than do plants having large simple leaves and more turbulent boundary layers. Kinetic ^2H enrichment in plant leaf water can also be rationalized in terms of leaf size and morphology when an apparent temperature-dependent isotope effect, acting in opposition to evaporative enrichment, is taken into account. Accounting for this temperature -dependent isotope effect helps to: (1) reconcile hydrogen kinetic fractionation inconsistencies for different leaves; (2) explain a temperature effect previously attributed to variable biochemical fractionation during cellulose synthesis, and; (3) verify hydrogen biochemical effects in plants. This improved characterization of the oxygen and hydrogen isotopic effects in plants, using the modified Cellulose Model, helped

  3. 2010-2015 Juvenile fish ecology in the Nisqually River Delta and Nisqually Reach Aquatic Reserve

    Science.gov (United States)

    Hodgson, Sayre; Ellings, Christopher S.; Rubin, Steve P.; Hayes, Michael C.; Duval, Walker; Grossman, Eric E.

    2017-01-01

    The return of tidal inundation to over 750 acres of the U. S. Fish and Wildlife Service Billy Frank Jr. Nisqually National Wildlife Refuge (NNWR) in fall of 2009 was the crowning moment in the effort to protect and restore the Nisqually Delta. The Nisqually NWR project complemented three earlier restoration projects completed by the Nisqually Indian Tribe (Tribe) on tribal property to restore over 900 acres of the estuary, representing the largest estuary restoration project in the Pacific Northwest and one of the most significant advances to date towards the recovery of Puget Sound (USFWS 2005). In 2011 the Washington Department of Natural Resources (WADNR established the over 14000 acre Nisqually Reach Aquatic Reserve (Reserve), complementing the protection and restoration successes in the Nisqually Delta. The Reserve includes all state-owned aquatic lands around Anderson, Ketron and Eagle islands and part of McNeil Island (Figure 1, WDNR 2011). The Reserve also includes a diverse assemblage of nearshore and offshore habitats important to resident and migratory fish including federal endangered species act listed fish like Chinook salmon (Oncorynchus tshawytscha) and steelhead (O. mykiss). Studies in the Nisqually Estuary (Ellings and Hodgson 2007, David et al. 2014, Ellings et al. 2016) and South Puget Sound (Duffy 2003) have summarized fish use of the area. However, the fish ecology of the reserve had not been systematically surveyed. The Tribe, U.S. Geological Survey (USGS), NNWR, Nisqually River Foundation (NRF), and others are currently conducting a multi-year, interdisciplinary, hypothesis-based research and monitoring study investigating the impact of delta restoration on estuarine processes, habitat structures, and functions. Our interdisciplinary monitoring framework enables us to link key estuarine processes with habitat development and biological response at multiple scales across the restored footprint, reference marshes, and throughout the Nisqually

  4. Outbreaks of the brown planthopper Nilaparvata lugens (Stål) in the Yangtze River Delta: immigration or local reproduction?

    Science.gov (United States)

    Hu, Gao; Lu, Fang; Zhai, Bao-Ping; Lu, Ming-Hong; Liu, Wan-Cai; Zhu, Feng; Wu, Xiang-Wen; Chen, Gui-Hua; Zhang, Xiao-Xi

    2014-01-01

    An effective control strategy for migratory pests is difficult to implement because the cause of infestation (i.e., immigration or local reproduction) is often not established. In particular, the outbreak mechanisms of the brown planthopper, Nilaparvata lugens (Stål), an insect causing massive losses in rice fields in the Yangtze River Delta in China, are frequently unclear. Field surveys of N. lugens were performed in Jiangsu and Zhejiang Provinces in 2008 to 2010 and related historical data from 2003 onwards were collected and analyzed to clarify the cause of these infestations. Results showed that outbreaks of N. lugens in the Yangtze River Delta were mostly associated with an extremely high increase in population. Thus, reproduction rather than immigration from distant sources were the cause of the infestations. Although mass migration occurred late in the season (late August and early September), the source areas of N. lugens catches in the Yangtze River Delta were mainly located in nearby areas, including the Yangtze River Delta itself, Anhui and northern Jiangxi Provinces. These regions collectively form the lower-middle reaches of the Yangtze River, and the late migration can thus be considered as an internal bioflow within one population.

  5. Multiple linear regression and artificial neural networks for delta-endotoxin and protease yields modelling of Bacillus thuringiensis.

    Science.gov (United States)

    Ennouri, Karim; Ben Ayed, Rayda; Triki, Mohamed Ali; Ottaviani, Ennio; Mazzarello, Maura; Hertelli, Fathi; Zouari, Nabil

    2017-07-01

    The aim of the present work was to develop a model that supplies accurate predictions of the yields of delta-endotoxins and proteases produced by B. thuringiensis var. kurstaki HD-1. Using available medium ingredients as variables, a mathematical method, based on Plackett-Burman design (PB), was employed to analyze and compare data generated by the Bootstrap method and processed by multiple linear regressions (MLR) and artificial neural networks (ANN) including multilayer perceptron (MLP) and radial basis function (RBF) models. The predictive ability of these models was evaluated by comparison of output data through the determination of coefficient (R 2 ) and mean square error (MSE) values. The results demonstrate that the prediction of the yields of delta-endotoxin and protease was more accurate by ANN technique (87 and 89% for delta-endotoxin and protease determination coefficients, respectively) when compared with MLR method (73.1 and 77.2% for delta-endotoxin and protease determination coefficients, respectively), suggesting that the proposed ANNs, especially MLP, is a suitable new approach for determining yields of bacterial products that allow us to make more appropriate predictions in a shorter time and with less engineering effort.

  6. Outbreaks of the Brown Planthopper Nilaparvata lugens (Stål) in the Yangtze River Delta: Immigration or Local Reproduction?

    Science.gov (United States)

    Zhai, Bao-Ping; Lu, Ming-Hong; Liu, Wan-Cai; Zhu, Feng; Wu, Xiang-Wen; Chen, Gui-Hua; Zhang, Xiao-Xi

    2014-01-01

    An effective control strategy for migratory pests is difficult to implement because the cause of infestation (i.e., immigration or local reproduction) is often not established. In particular, the outbreak mechanisms of the brown planthopper, Nilaparvata lugens (Stål), an insect causing massive losses in rice fields in the Yangtze River Delta in China, are frequently unclear. Field surveys of N. lugens were performed in Jiangsu and Zhejiang Provinces in 2008 to 2010 and related historical data from 2003 onwards were collected and analyzed to clarify the cause of these infestations. Results showed that outbreaks of N. lugens in the Yangtze River Delta were mostly associated with an extremely high increase in population. Thus, reproduction rather than immigration from distant sources were the cause of the infestations. Although mass migration occurred late in the season (late August and early September), the source areas of N. lugens catches in the Yangtze River Delta were mainly located in nearby areas, including the Yangtze River Delta itself, Anhui and northern Jiangxi Provinces. These regions collectively form the lower-middle reaches of the Yangtze River, and the late migration can thus be considered as an internal bioflow within one population. PMID:24558459

  7. Fgf signaling controls pharyngeal taste bud formation through miR-200 and Delta-Notch activity.

    Science.gov (United States)

    Kapsimali, Marika; Kaushik, Anna-Lila; Gibon, Guillaume; Dirian, Lara; Ernest, Sylvain; Rosa, Frederic M

    2011-08-01

    Taste buds, the taste sensory organs, are conserved in vertebrates and composed of distinct cell types, including taste receptor, basal/presynaptic and support cells. Here, we characterize zebrafish taste bud development and show that compromised Fgf signaling in the larva results in taste bud reduction and disorganization. We determine that Fgf activity is required within pharyngeal endoderm for formation of Calb2b(+) cells and reveal miR-200 and Delta-Notch signaling as key factors in this process. miR-200 knock down shows that miR-200 activity is required for taste bud formation and in particular for Calb2b(+) cell formation. Compromised delta activity in mib(-/-) dramatically reduces the number of Calb2b(+) cells and increases the number of 5HT(+) cells. Conversely, larvae with increased Notch activity and ascl1a(-/-) mutants are devoid of 5HT(+) cells, but have maintained and increased Calb2b(+) cells, respectively. These results show that Delta-Notch signaling is required for intact taste bud organ formation. Consistent with this, Notch activity restores Calb2b(+) cell formation in pharyngeal endoderm with compromised Fgf signaling, but fails to restore the formation of these cells after miR-200 knock down. Altogether, this study provides genetic evidence that supports a novel model where Fgf regulates Delta-Notch signaling, and subsequently miR-200 activity, in order to promote taste bud cell type differentiation.

  8. Testing optically stimulated luminescence dating on sand-sized quartz of deltaic deposits from the Sperchios delta plain, central Greece

    Directory of Open Access Journals (Sweden)

    Evangelos Tsakalos

    2018-04-01

    Full Text Available This study reports on the first investigation into the potential of luminescence dating to establish a chronological framework for the depositional sequences of the Sperchios delta plain, central Greece. A series of three borehole cores (20 m deep and two shallow cores (4 m deep, from across the delta plain, were extracted, and samples were collected for luminescence dating. The luminescence ages of sand-sized quartz grains were obtained from small aliquots of quartz, using the Single-Aliquot Regenerative-dose (SAR protocol. The equivalent dose determination included a series of tests and the selection of the Minimum Age Model (MAM as the most appropriate statistical model. This made it possible to confirm the applicability of quartz Optically Stimulated Luminescence (OSL dating to establish absolute chronology for deltaic sediments from the Sperchios delta plain.Testing age results of the five cores showed that the deltaic sediments were deposited during the Holocene. A relatively rapid deposition is implied for the top ∼14 m possibly as a result of the deceleration in the rate of the sea-level rise and the transition to terrestrial conditions, while on the deeper parts, the reduced sedimentation rate may indicate a lagoonal or coastal environment. Keywords: Luminescence dating, Holocene, Sedimentation rates, Deltaic deposits, Sperchios delta plain, Central Greece

  9. Nigeria National Petroleum Reserves Asset: Looking Beyond the Niger Delta

    International Nuclear Information System (INIS)

    Obaje, P. N.

    2002-01-01

    Nigeria's current national petroleum reserves asset (proven) put at 28 billion barrels of oil and 150 trillion standard cubic feet of gas derives mainly from the Niger Delta onshore and offshore.However, there are opportunities to tremendously add to this asset from the inland basins. These inland basins have continued to frustrate the efforts of many explorers, principally because of their virginity and far distance from existing infrastructure, and for these reasons, many international companies have turned their focus away from frontier onshore to frontier deep-water and ultra deep-water offshore.Petroleum exploration, particularly in the Sudan and Chad Republics has shown that commercial success can be achieved in our own sector, even if it may take some time to put all the elements together. Some pointers have been found from the successes in the other rifted inland basins and the strategies adopted there have been examined in this paper. Congnizance has also been taken of the relative success of Shell's Kolmani River-1 well (33 billion cubit feet of gas) in the Gongola Basin. The paper went ahead to highlight potential petroleum systems in the different sectors of Nigeria's inland basins.Recommendations have also been put forward, which include amongst others (i) the introduction of a JV arrangement that allows State Governments on the inland basins to participate in the exploration for hydrocarbons in their domains (ii) tie future allocation of offshore blocks to acquisition of at least a block in any of the inland basins (iii) initiate a programme of deep drilling and coring of at least one research well to penetrate the entire sedimentary rock successions in each of the inland basins to facilitate a better understanding of their petroleum geology and benefit future exploration campaigns; to be funded and supervised by the Petroleum Technology Development Fund (PTDF)

  10. Polarized antiquark flavor asymmetry DELTA anti u(x)-DELTA anti d(x) and the pion cloud

    CERN Document Server

    Fries, R J; Weiss, C

    2003-01-01

    The flavor asymmetry of the unpolarized antiquark distributions in the proton, anti u(x)- anti d(x)0. Using a simple chiral linear sigma model as an example, we demonstrate that in the meson cloud picture a large positive DELTA anti u(x)-DELTA anti d(x) can be obtained from pi-sigma interference contributions. This calls into question previous estimates based on rho-meson contributions alone, and indicates how the results of the meson cloud picture may be reconciled with those of quark-based models. (orig.)

  11. 77 FR 61592 - Arkansas Electric Cooperative Corporation; Mississippi Delta Energy Agency; Clarksdale Public...

    Science.gov (United States)

    2012-10-10

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL12-110-000] Arkansas Electric Cooperative Corporation; Mississippi Delta Energy Agency; Clarksdale Public Utilities Commission.... 825(h), Arkansas Electric Cooperative Corporation, Mississippi Delta Energy Agency, and its two...

  12. Profitability and constraints in the marketing of poultry birds in Delta ...

    African Journals Online (AJOL)

    Profitability and constraints in the marketing of poultry birds in Delta central agricultural zone, Delta state, Nigeria. ... Randomly selected 54 poultry bird marketers were surveyed in 5 major markets. ... EMAIL FULL TEXT EMAIL FULL TEXT

  13. Crude Oil, a Blessing and Impediment in Niger Delta Polity: Tanure ...

    African Journals Online (AJOL)

    Journal Home > Special Edition 2011 > ... Oil has constituted a physical problem to Delta State and Nigeria as a whole. ... impediment in Delta of Nigeria; Economic growth constraints, socio-political problems and Neo-colonialism; and finally,

  14. Phosphorus {delta}-doped silicon: mixed-atom pseudopotentials and dopant disorder effects

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Damien J; Marks, Nigel A [Nanochemistry Research Institute, Curtin University, PO Box U1987, Perth WA 6845 (Australia); Warschkow, Oliver; McKenzie, David R, E-mail: d.carter@curtin.edu.au [Centre for Quantum Computer Technology, School of Physics, University of Sydney, Sydney, NSW 2006 (Australia)

    2011-02-11

    Within a full density functional theory framework we calculate the band structure and doping potential for phosphorus {delta}-doped silicon. We compare two different representations of the dopant plane; pseudo-atoms in which the nuclear charge is fractional between silicon and phosphorus, and explicit arrangements employing distinct silicon and phosphorus atoms. While the pseudo-atom approach offers several computational advantages, the explicit model calculations differ in a number of key points, including the valley splitting, the Fermi level and the width of the doping potential. These findings have implications for parameters used in device modelling.

  15. A Delta Operator Approach for the Discrete-Time Active Disturbance Rejection Control on Induction Motors

    Directory of Open Access Journals (Sweden)

    John Cortés-Romero

    2013-01-01

    Full Text Available The problem of active disturbance rejection control of induction motors is tackled by means of a generalized PI observer based discrete-time control, using the delta operator approach as the methodology of analyzing the sampled time process. In this scheme, model uncertainties and external disturbances are included in a general additive disturbance input which is to be online estimated and subsequently rejected via the controller actions. The observer carries out the disturbance estimation, thus reducing the complexity of the controller design. The controller efficiency is tested via some experimental results, performing a trajectory tracking task under load variations.

  16. A one-dimensional model of resonances with a delta barrier and mass jump

    International Nuclear Information System (INIS)

    Alvarez, J.J.; Gadella, M.; Heras, F.J.H.; Nieto, L.M.

    2009-01-01

    In this Letter, we present a one-dimensional model that includes a hard core at the origin, a Dirac delta barrier at a point in the positive semiaxis and a mass jump at the same point. We study the effect of this mass jump in the behavior of the resonances of the model. We obtain an infinite number of resonances for this situation, showing that for the case of a mass jump the imaginary part of the resonance poles tend to a fixed value depending on the quotient of masses, and demonstrate that none of these resonances is degenerated.

  17. Carbon Stocks in Permafrost-Affected Soils of the Lena River Delta

    Science.gov (United States)

    Zubrzycki, S.; Kutzbach, L.; Grosse, G.; Desyatkin, A.; Pfeiffer, E.

    2012-12-01

    The soil organic carbon stock (SSOC) of soils in arctic permafrost regions is known to be significant but is insufficiently investigated so far. Previous SSOC studies report mainly the gravimetric carbon (C) contents and are limited to the active layer depth at the time of sampling. Since C deposits in permafrost regions are likely to become a future C source, more detailed investigations of the presently frozen likely carbon-rich sediment and soil layers are of importance. Our investigations were performed on Samoylov Island in the southern-central part of the Lena River Delta (32,000 km2) which is the largest arctic delta and the fifth largest delta worldwide. Samoylov Island is representative for the Lena River Delta's first terrace and the active floodplains. Within this study a new portable Snow-Ice-Permafrost-Research-Establishment (SIPRE) auger was used during a spring field session to obtain 1 m deep frozen soil cores (n = 29) distributed over all known soil and vegetation units. These cores are analyzed for bulk contents of nitrogen (N) and C, ice content and bulk density (BD) and to determine the SSOC including the rarely investigated currently permanently frozen layers up to 1 m depth on Samoylov Island. Our study provides evidence for high SSOC for a depth of 1 m for the investigated area ranging between 7 kg m-2 and 48 kg m-2. Considering the spatial extent of different soil units on the two geomorphological units of Samoylov Island, the area-weighted average SSOC were 29 kg m-2 (n = 22) for the first terrace and 14 kg m-2 (n = 7) for the active floodplain. For the correspondent soil units of Turbels and Orthels in circumpolar permafrost regions a mean SSOC of 27 kg m-2 (min: 0.1 kg m-2, max: 126 kg m-2) for a depth of 1 m was reported [1]. For up-scaling solely over the soil-covered areas of the Lena River Delta, we excluded all water bodies >3,600 m2 from the geomorphological units studied (first river terrace and the active floodplains) and

  18. Application in Down-hole Milling Operations In Niger Delta.

    African Journals Online (AJOL)

    ENGINEERS

    export terminals, 275 flow stations, 10 gas plants, 3 refineries and a massive natural ..... clear of the Niger Delta', adding that, 'The Chinese government by investing in stolen .... Development Agency (SMEDAN); to help boost the growth of both countries' ..... “The Rule of Oil: Petro-Politics and the Anatomy of an Insurgency”.

  19. Gambiense Sleeping Sickness In The Abraka Region Of Delta State ...

    African Journals Online (AJOL)

    Gambiense Sleeping Sickness In The Abraka Region Of Delta State, Nigeria: Passive Case Detection (Pcd) At The Baptist Medical Centre (BMC) Eku 1999 – 2004. ... The highest prevalence of infection was among patients aged between 26-35 years with 35.6% infection rate, 23.3 percent was recorded among those aged ...

  20. year Review of Patients on DOTS in Delta State, Nigeria

    African Journals Online (AJOL)

    UNIBEN

    1Department of Community Medicine, Delta State University Teaching ... Therapy Short-course (DOTS), DOTS plus, and the Stop TB Strategy. ... Methods: In this descriptive records review of years 2011-2015, existing data ... Treatment success rate improved from 68.3% in ..... exploration and social interventions to curb it.

  1. Delta-gamma-theta Hedging of Crude Oil Asian Options

    Directory of Open Access Journals (Sweden)

    Juraj Hruška

    2015-01-01

    Full Text Available Since Black-Scholes formula was derived, many methods have been suggested for vanilla as well as exotic options pricing. More of investing and hedging strategies have been developed based on these pricing models. Goal of this paper is to derive delta-gamma-theta hedging strategy for Asian options and compere its efficiency with gamma-delta-theta hedging combined with predictive model. Fixed strike Asian options are type of exotic options, whose special feature is that payoff is calculated from the difference of average market price and strike price for call options and vice versa for the put options. Methods of stochastic analysis are used to determine deltas, gammas and thetas of Asian options. Asian options are cheaper than vanilla options and therefore they are more suitable for precise portfolio creation. On the other hand their deltas are also smaller as well as profits. That means that they are also less risky and more suitable for hedging. Results, conducted on chosen commodity, confirm better feasibility of Asian options compering with vanilla options in sense of gamma hedging.

  2. Assessing School Facilities in Public Secondary Schools in Delta ...

    African Journals Online (AJOL)

    This study investigated school facilitates in public secondary schools in Delta State, Nigeria. The purpose of the study was to find out the state of the facilities, the types of maintenance carried out on the facilities by school administrators, the factors encouraging school facilities depreciation and the roles of school ...

  3. Monte Carlo simulations of the stability of delta-Pu

    DEFF Research Database (Denmark)

    Landa, A.; Soderlind, P.; Ruban, Andrei

    2003-01-01

    The transition temperature (T-c) for delta-Pu has been calculated for the first time. A Monte Carlo method is employed for this purpose and the effective cluster interactions are obtained from first-principles calculations incorporated with the Connolly-Williams and generalized perturbation methods...

  4. Evolution of the Niger Delta, present dynamics and the future ...

    African Journals Online (AJOL)

    Evolution of the Niger Delta is closely linked to the geodynamics related to the separation of the African and South American continents and the tectonics of the formation of the Benue Trough. Tectonic activities, climate and eustasy are the major factors responsible for transgression and regression through the entrant point ...

  5. Validity and reliability of the Delta Healthy Eating Attitudes Scale

    Science.gov (United States)

    The objective of this study was to evaluate psychometric properties of an instrument developed to measure psychosocial factors related to the Dietary Guidelines for Americans for a nutrition intervention in the Lower Mississippi Delta (LMD). Social Cognitive Theory constructs social support (SS), s...

  6. Eating Habits of the Elderly in Asaba, Delta State, Nigeria ...

    African Journals Online (AJOL)

    Objectives: The study was undertaken to describe the eating habits of literate elderly in Asaba, urban city in Delta State of Nigeria. Methods: A total of 176 elderly male (62.5%) and female (37.5%) aged 50years and above who attended Medical Lectures of the Ebreme foundation for the elderly were enrolled in this study.

  7. Morphodynamics of the Manyema Tidal Delta at Kunduchi, Tanzania

    African Journals Online (AJOL)

    Keywords: Morphodynamics, Kunduchi, Manyema, shoreline change, tidal creek, tidal delta. Abstract—The prevailing northward longshore drift of beach sand on the northern part of Msasani Bay, north of Dar es Salaam, is interrupted at Kunduchi by the tidal flushing of ... Western Indian Ocean J. Mar. Sci. Vol. 11, No. 2, pp.

  8. Ibani (Niger Delta) Traditional Religion and Social Morality | Jaja ...

    African Journals Online (AJOL)

    The Ibani is of the Ijo extraction in the Niger Delta of Nigeria. The belief in a Supreme Being called Tamuno but also on multitude of deities because of the environment in which they live. They believe that these deities perform social functions that stabilize society. Ibani cosmology revolve round the tripod – God, deities and ...

  9. Interacting boson model with surface delta interaction between nucleons

    International Nuclear Information System (INIS)

    Druce, C.; Moszkowski, S.A.

    1984-01-01

    The surface delta interaction is used as an effective nucleon-nucleon interaction to investigate the structure and interaction of the bosons in the interacting boson model. The authors have obtained analytical expressions for the coefficients of a multipole expansion of the neutron-boson proton-boson interaction for the case of degenerate orbits

  10. Ethnic Minority Problems in the Niger Delta | Quaker-Dokubo ...

    African Journals Online (AJOL)

    As a conceptual background typical types of minorities and typical sources of minority conflict are outlined. A historical overview is given of the problems Niger Delta minorities have been experiencing. Their grievances and demands are highlighted, and the responses of different Nigerian governments are discussed.

  11. Perceptions, Attitudes and Practices on Schistosomiasis in Delta ...

    African Journals Online (AJOL)

    The main objective of the study reported here was to assess the knowledge, attitude/perception and practices of the people in Oshimili South and Ndokwa Northeast Local Government Areas of Delta State in Nigeria. A cross-sectional study of 400 randomly selected persons aged ≥15 years was undertaken using a uniform ...

  12. Final Narrative Report on Nursing Ethics at Delta College.

    Science.gov (United States)

    Pfeiffer, Raymond S.

    This four-part report describes a project undertaken by Delta College to implement two required bioethics courses for nursing students: an introductory course in ethical theories and an advanced course in applications of these theories in nursing. After Part I relates how funding for the project was secured and used, Part II delineates the…

  13. The Localizing Value Of Focal Delta Slowing In Temporal Lobe ...

    African Journals Online (AJOL)

    Slow wave EEG had a higher marginal probability than neuropsychological assessment of predicting the focus, and was equally effective as other investigative methods. Conclusion These results suggest that focal temporal delta slowing is useful in the localization of epileptogenic foci. There was no discordance with the ...

  14. Practical Design of Delta-Sigma Multiple Description Audio Coding

    DEFF Research Database (Denmark)

    Leegaard, Jack Højholt; Østergaard, Jan; Jensen, Søren Holdt

    2014-01-01

    It was recently shown that delta-sigma quantization (DSQ) can be used for optimal multiple description (MD) coding of Gaussian sources. The DSQ scheme combined oversampling, prediction, and noise-shaping in order to trade off side distortion for central distortion in MD coding. It was shown that ...

  15. Evaluation Of Delta State E-Government Website | Chete ...

    African Journals Online (AJOL)

    The study evaluates Delta state government website by adopting the method used since 2001 in evaluating national government websites. The questionnaire and web survey techniques were adopted for this study. The data from the questionnaire was analyzed using statistical package for social sciences (SPSS) and the ...

  16. training needs of school inspectors for quality instruction in delta

    African Journals Online (AJOL)

    www.globaljournalseries.com; Info@globaljournalseries.com ... 29. Jude Ekuevugbe Omorigho, Post Primary Education Board, Asaba, Delta State, Nigeria. ... Effective communication training for school .... Decision. Inspectors. 3.12. 0.25. Important. Headmasters. 2.96. 0.11. Table 3, shows that the individual means.

  17. Atlantic humpback dolphins Sousa teuszii in the Saloum Delta ...

    African Journals Online (AJOL)

    During October and November 2015, the first systematic survey of Sousa teuszii was carried out in the Saloum Delta (Senegal, West Africa), comprising 1 617.5 km of boat-based survey coverage. Thirty sightings were recorded in the Saloum and Diomboss rivers, and along the southern coastline. Dolphins were also ...

  18. Environmental Degradation in Oil Producing Areas of Niger Delta ...

    African Journals Online (AJOL)

    Due to oil exploration and other human activities in the Niger Delta region, there is evidence of environmental degradation all over the area (Oronto, 1998). Environmental degradation is occasioned by consistent flow of industrial waste, oil spills, gas flares, fire disaster, acid rain, flooding erosion, etc., which has led to the ...

  19. Acid Rain in Niger Delta Region: Implication on Water Resources ...

    African Journals Online (AJOL)

    This research focused on the effect of acid rain on the water quality of the Niger Delta region of Nigeria. Three hundred water samples were collected: 100 water samples from rain, 100 from open wells and 100 from rivers. The water samples were analysed using the paired t-test and multiple correlation analysis to ascertain ...

  20. Adolescent Sexual and Reproductive Health in the Niger Delta ...

    African Journals Online (AJOL)

    There has been an increasing awareness of the need to pay special focus on the adolescent and their sexual and reproductive health. This article reviews the sexual and reproductive health of adolescents in the Niger Delta region (NDR) of Nigeria. The objective is to bring to focus these important issues in the region.

  1. Isospin-breaking nuclear forces with delta degrees of freedom

    International Nuclear Information System (INIS)

    Epelbaum, E.

    2008-01-01

    The leading contributions to the isospin-violating (IV) two- and three-nucleon forces in effective field theory with explicit delta degrees of freedom are discussed. Presented at the 20th Few-Body Conference, Pisa, Italy, 10-14 September 2007. (author)

  2. Experience on tangent delta norms adopted for repaired generator

    International Nuclear Information System (INIS)

    Misra, N.N.; Sood, D.K.

    2005-01-01

    The repair techniques of the generators are very crucial for avoiding prolonged forced outages. The crucial decisions based on sound knowledge and judgement becomes essential in many cases. The unit under discussions had failed on account of flash over in the Exciter end overhang windings. The failure resulted in damaged to the stator bars as well as generator core. The damaged end packets of the stator core were replaced at site. The total winding bars were removed from stator core and damaged bars were replaced with new bars. The rest of the bars were tested for tangent delta tests for reuse. Acceptance norms of 0.6% tip up from 0.2pu to 0.6pu of rated stator voltage were adopted. Some of the bars outside the acceptable limits of tangent delta were shifted close to neutral so that the standard norms of tan delta are met. This was felt necessary because lead-time for procurement of new bars was more than six months. The above-adopted norms for tangent delta will be of much use for the operating utilities. The unit under discussions was of 67.5 MW operating at 50 Hz, 0.85 pf lag and had logged 66160.46 operating hours before failure. (author)

  3. Use of Cybercafe's Services by Households in Delta State, Nigeria ...

    African Journals Online (AJOL)

    Cyber cafés' provide important public services. They provide access to wide range of information through the internet via the computer. The study is centered on the use of cyber cafés by households in Delta State. Services provided by the cyber café's were identified. The study revealed that Household with children under ...

  4. Dermal absorption of the insecticide lindane (1 delta, 2 delta, 3 beta, 4 delta, 5 delta, 6 beta-hexachlorocyclohexane) in rats and rhesus monkeys: Effect of anatomical site

    International Nuclear Information System (INIS)

    Moody, R.P.; Ritter, L.

    1989-01-01

    Dermal absorption of the insecticide lindane (1 delta, 2 delta, 3 beta, 4 delta, 5 delta, 6 beta-hexachlorocyclohexane) was determined in rats and rhesus monkeys. Lindane is in widespread use as a 1% cream or lotion scabicide formulation and as a 1% miticide shampoo for body lice control in humans. Results obtained following our in vivo dermal absorption procedure demonstrated that 18 +/- 4.1%, 34 +/- 5.2%, and 54 +/- 26.3% of the applied dose was absorbed following topical applications at a rate of 1.5 micrograms/cm2 (6.2 micrograms/100 microliters of acetone) of the 14C-labeled pesticide to 4.2-cm2 regions of the forearm (n = 8), forehead (n = 7), and palm (n = 4) of rhesus monkeys, respectively. Dose sites were washed with soapy water 24 h posttreatment. Comparative studies in rats (n = 5) dosed middorsally demonstrated 31 +/- 9.5% absorption. Statistical analysis of the 14C excretion kinetics demonstrated slower clearance of lindane from rats than monkey forearm, forehead, or palm. Intramuscular (im) injections of 14C-lindane gave 52 +/- 7.1% recovery in monkey (n = 8) and 64 +/- 5.9% in rats (n = 5), suggesting body storage of this lipophilic chemical

  5. Characterization of middle Eocene tide-influenced delta: a study ...

    Indian Academy of Sciences (India)

    42

    Running Title: Eocene tide-influenced delta in South Cambay Basin. Manuscript. Click here to view linked References. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10 .... systematic documentation of the facies types to establish the depositional environment of the .... Hazad Member consists of a number of sandstone units separated by intervening ...

  6. Schrodinger operators with delta-interactions supported on conical surfaces

    Czech Academy of Sciences Publication Activity Database

    Behrndt, J.; Exner, Pavel; Lotoreichik, V.

    2014-01-01

    Roč. 47, č. 35 (2014), s. 355202 ISSN 1751-8113 R&D Projects: GA ČR(CZ) GA14-06818S; GA MŠk 7AMB13AT010 Institutional support: RVO:61389005 Keywords : Schrödinger operator * delta potential * infinite discrete spectrum Subject RIV: BE - Theoretical Physics Impact factor: 1.583, year: 2014

  7. Amnesty in the Niger Delta: vertical movement towards self ...

    African Journals Online (AJOL)

    ... promises of infrastructure development in the region and direct payments of oil revenues to host-communities. This paper seeks to examine the recent developments vis-à-vis the government's amnesty initiative to determine if this policy has bridged the gap in the longstanding selfdetermination demands of the Niger Delta ...

  8. Drones on the delta | IDRC - International Development Research ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-11-25

    Nov 25, 2016 ... Ghana's Volta River delta is an area vulnerable to climate change, with rising seas and increasingly powerful storms driving flooding and erosion, leaving authorities there questioning whether the best response involves solutions such as sea walls or migration. A group of researchers is using drones to ...

  9. aranthus cruentus L) in the Niger Delta Region of Nigeria

    African Journals Online (AJOL)

    ABSTRACT. Experiments were conducted in 1987 and 1988 to study the response of Amaranthus cruentus L. to flooded soils at Ekpoma, situated in-the Niger Delta Region of Nigeria. The objective of this study was to examine the effect of flooding on yield of A. Céiieiìtus. The study revealed that the negative response of the ...

  10. The Economic Dimensions of the Niger Delta Ethnic Conflicts ...

    African Journals Online (AJOL)

    This paper presents a descriptive analysis of the remote and immediate causes of the armed ethnic conflicts in the Niger Delta in Nigeria and attempts to proffer a strategic approach rather than the use of brute force in managing the conflicts. The study revealed that the underlying cause of the conflict is the prolonged ...

  11. A Signal-Interleaving Complex Bandpass Sigma-Delta Converter

    DEFF Research Database (Denmark)

    Wad, Paul Emmanuel

    1997-01-01

    Complex or quadrature Sigma-Delta converters operate on complex signals, i.e. signals consisting of a real and an imaginary component, whereas conventional converters operate only on real signals. The advantage of complex signal processing in the discrete-time domain is that the entire sampling...

  12. Towards an Ethics of the Environment in the Niger Delta

    African Journals Online (AJOL)

    FIRST LADY

    and the responsibility for both human and non-human components of nature are indeed wholly ... intend to do in this work therefore is to evolve an ethics of the Niger Delta environment which ... African Research Review Vol. 4(3a) July, 2010.

  13. Fundraising processes in Nigerian Academic Libraries: The Delta ...

    African Journals Online (AJOL)

    The paper examines fundraising processes in academic libraries in Delta State. The aim is to find out the extent to which fund raising processes can help in solving funding problems in academic libraries. The descriptive research method was employed. Eleven academic libraries in Delt a State were used in this study, that ...

  14. 2009-2010 USACE Vicksburg District Lidar: Mississippi River Delta

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LiDAR collected at 1.0 points per square meter (1.0m GSD) for the entire portion of the Mississippi River Delta in the Vicksburg District. This area was flown during...

  15. Hepatitis delta in HIV-infected individuals in Europe

    DEFF Research Database (Denmark)

    Soriano, Vincent; Grint, Daniel; Monforte, Antonellad'arminio

    2011-01-01

    BACKGROUND:: Hepatitis delta virus (HDV) infection results in the most aggressive form of chronic viral hepatitis. There is scarce information about the prevalence, epidemiology, virological profile and natural historyof hepatitis delta in HIV patients. METHODS:: From 16,597 HIV patients enrolled......-RNA was quantified using a real-time PCR method. RESULTS:: A total of 61/422 HBsAg+ carriers were anti-HDV+ (prevalence: 14.5%). Hepatitis delta predominated in intravenous drug users and for this reason in South and/or East Europe. Serum HDV-RNA was detectable in 87% of tested anti-HDV+ patients, with a median...... titer of 1.76x10¿copies/ml. Overall, delta hepatitis patients showed lower serum HBV-DNA than the rest of HBsAg+ carriers, although the inhibitory effect of HDV on HBV replication was not recognized in HBV genotype D patients.Whereas HDV was not associated with progression to AIDS, it significantly...

  16. Comparative Noise Pollution Study Of Some Major Towns In Delta ...

    African Journals Online (AJOL)

    Comparative noise pollution studies have been carried out in some major towns in Delta State, Nigeria using a PIONneer 65 noise dosimeter. The noise measurements were taken at ten points within each of the towns at an interval of 30 minutes during the peak period of the day and at the cool of the night. The results ...

  17. Delta Healthy Sprouts: Participants' Diet and Food Environment at Baseline

    Science.gov (United States)

    Local food environments influence the nutrition and health of area residents. This baseline analysis focuses on the food environments of women who participated in the Delta Healthy Sprouts project, a randomized, controlled, comparative trial designed to test the efficacy of two Maternal, Infant, an...

  18. The Problem with the Delta Cost Project Database

    Science.gov (United States)

    Jaquette, Ozan; Parra, Edna

    2016-01-01

    The Integrated Postsecondary Education System (IPEDS) collects data on Title IV institutions. The Delta Cost Project (DCP) integrated data from multiple IPEDS survey components into a public-use longitudinal dataset. The DCP Database was the basis for dozens of journal articles and a series of influential policy reports. Unfortunately, a flaw in…

  19. Nonlinearities in SC Delta-Sigma A/D Converters

    DEFF Research Database (Denmark)

    Steensgaard-Madsen, Jesper

    1998-01-01

    The effects of using nonlinear low-gain opamps in switched-capacitor delta-sigma modulators are analyzed. Using unconventional topologies, the state variables are made essentially uncorrelated with the input signal, hence opamp nonlinearity will cause very little harmonic distortion. Nonlinearity...

  20. Prevalence of Neonatal Jaundice on Central Hospital, Warri, Delta ...

    African Journals Online (AJOL)

    Methods: 272 babies (aged 1 – 30 days) the Neonatal Clinic of the Department of Child Health, Central Hospital, Warri, Delta State between June 2009 and June 2010 were examined daily for evidence of jaundice. Those with serum bilirubin ³15mg/100ml were subjected to additional clinical and laboratory investigations to ...

  1. Mantle electrical conductivity profile of Niger delta region

    Indian Academy of Sciences (India)

    The mantle electrical conductivity-depth profile of the Niger delta region in Nigeria has been determined using solar quiet day ionospheric current (Sq).The magnetometer data obtained in 2010 from geomagnetic stations installed in Lagos by magnetic dataset (MAGDAS) in 2008 and data from magnetometers installed in ...

  2. The Niger Delta: State Repression and Violence Nexus

    African Journals Online (AJOL)

    crosdel emuedo

    2005-02-19

    Feb 19, 2005 ... This explains its concern only with unimpeded access to crude oil at very cheap ... The people of the Niger Delta on the other hand, places premium on the concept of human ... going amnesty, over 123 hostages were taken.

  3. delta-Opioid-induced pharmacologic myocardial hibernation during cardiopulmonary resuscitation.

    Science.gov (United States)

    Fang, Xiangshao; Tang, Wanchun; Sun, Shijie; Weil, Max Harry

    2006-12-01

    Cardiac arrest and cardiopulmonary resuscitation is an event of global myocardial ischemia and reperfusion, which is associated with severe postresuscitation myocardial dysfunction and fatal outcome. Evidence has demonstrated that mammalian hibernation is triggered by cyclic variation of a delta-opiate-like compound in endogenous serum, during which the myocardial metabolism is dramatically reduced and the myocardium tolerates the stress of ischemia and reperfusion without overt ischemic and reperfusion injury. Previous investigations also proved that the delta-opioid agonist elicited the cardioprotection in a model of regional ischemic intact heart or myocyte. Accordingly, we were prompted to search for an alternative intervention of pharmacologically induced myocardial hibernation that would result in rapid reductions of myocardial metabolism and therefore minimize the myocardial ischemic and reperfusion injury during cardiac arrest and cardiopulmonary resuscitation. Prospective, controlled laboratory study. University-affiliated research laboratory. In the series of studies performed in the established rat and pig model of cardiac arrest and cardiopulmonary resuscitation, the delta-opioid receptor agonist, pentazocine, was administered during ventricular fibrillation. : The myocardial metabolism reflected by the concentration of lactate, or myocardial tissue PCO2 and PO2, is dramatically reduced during cardiac arrest and cardiopulmonary resuscitation. These are associated with less severe postresuscitation myocardial dysfunction and longer duration of postresuscitation survival. delta-Opioid-induced pharmacologic myocardial hibernation is an option to minimize the myocardial ischemia and reperfusion injury during cardiac arrest and cardiopulmonary resuscitation.

  4. On approximation and energy estimates for delta 6-convex functions.

    Science.gov (United States)

    Saleem, Muhammad Shoaib; Pečarić, Josip; Rehman, Nasir; Khan, Muhammad Wahab; Zahoor, Muhammad Sajid

    2018-01-01

    The smooth approximation and weighted energy estimates for delta 6-convex functions are derived in this research. Moreover, we conclude that if 6-convex functions are closed in uniform norm, then their third derivatives are closed in weighted [Formula: see text]-norm.

  5. On approximation and energy estimates for delta 6-convex functions

    Directory of Open Access Journals (Sweden)

    Muhammad Shoaib Saleem

    2018-02-01

    Full Text Available Abstract The smooth approximation and weighted energy estimates for delta 6-convex functions are derived in this research. Moreover, we conclude that if 6-convex functions are closed in uniform norm, then their third derivatives are closed in weighted L2 $L^{2}$-norm.

  6. Questioning triple rice intensification on the Vietnamese mekong delta floodplains

    NARCIS (Netherlands)

    Tran, Dung Duc; Halsema, van Gerardo; Hellegers, Petra J.G.J.; Ludwig, Fulco; Wyatt, Andrew

    2018-01-01

    Large areas of the Vietnamese Mekong Delta floodplains (VMDF) are protected by high dikes to facilitate three rice crops per year. While this has increased rice production, there is evidence that triple rice systems have negative long-term effects, both environmental and economic. Double rice

  7. The search for environmental justice in the Niger Delta and ...

    African Journals Online (AJOL)

    Right from the beginning Man has been given the privilege by his Creator to tender the earth and take dominion over his environment. But for the impoverished people of the Niger Delta region, the mainstay of Nigeria's oil wealth, the situation is ironically abysmal. The region has been the scene of protest, sometimes ...

  8. What are pregnant women in a rural Niger Delta community's ...

    African Journals Online (AJOL)

    To date, studies have sought cause and effect and have neglected the opinion of the people about what they perceive to be problematic and what they believe constitutes satisfactory maternity service provision. An exploratory qualitative study was carried out to identify pregnant women in a rural Niger Delta community's ...

  9. Production and decay properties of the delta (970) meson

    International Nuclear Information System (INIS)

    Gay, J.B.; Chaloupka, V.; Gavillet, Ph.; Hemingway, R.J.; Marzano, F.; Montanet, L.; Blokzijl, R.; Jongejans, B.; Massaro, G.G.G.; Heinen, P.M.; Metzger, W.J.; Timmermans, J.J.M.

    1976-01-01

    Using an 80 events per microbarn sample of K - p interactions at 4.2 GeV/c the production and decay properties of the delta(970) have been investigated in the following reactions: K - p→Σ + (1385)etaπ - and K - p→Σ + (1385)K 0 K - . (Auth.)

  10. Obesity and Health Risk of Children in the Mississippi Delta

    Science.gov (United States)

    Gamble, Abigail; Waddell, Dwight; Ford, M. Allison; Bentley, John P.; Woodyard, Catherine D.; Hallam, Jeffrey S.

    2012-01-01

    Background: Mississippi (MS) Delta adults and youth report obesity rates far exceeding those of the state and nation. State law requires in-school physical activity and nutrition practices to address childhood obesity but does not require evaluation of outcomes, specifically the impact on weight-related outcomes. This paper offers 3 things: (1)…

  11. Leena delta rännujutud / Riho Västrik

    Index Scriptorium Estoniae

    Västrik, Riho, 1965-

    2010-01-01

    Reisikiri Leena jõest filmi tegeva filmimeeskonna matkast Leena jõe delta tundras, kus satuti ka 1879. aastal purjelaeval "Jeannette" põhjapoolust vallutama tulnud ameerika polaaruurija DeLongi matmispaiga ja mälestusmärgi juurde

  12. Enhancing stakeholder participation in the Niger Delta region: the ...

    African Journals Online (AJOL)

    Nigeria's indigenous people, found in the Niger Delta area, have for many years experienced developmental challenges associated with oil exploration. The region has been perennially engulfed in various forms of agitation pertaining to self-government and resource control. Over the years, attempts to solve these ...

  13. delta 6 Hexadecenoic acid is synthesized by the activity of a soluble delta 6 palmitoyl-acyl carrier protein desaturase in Thunbergia alata endosperm.

    Science.gov (United States)

    Cahoon, E B; Cranmer, A M; Shanklin, J; Ohlrogge, J B

    1994-11-04

    delta 6 Hexadecenoic acid (16:1 delta 6) composes more than 80% of the seed oil of Thunbergia alata. Studies were conducted to determine the biosynthetic origin of the double bond of this unusual fatty acid. Assays of fractions of developing T. alata seed endosperm with [1-14C]palmitoyl (16:0)-acyl carrier protein (ACP) revealed the presence of a soluble delta 6 desaturase activity. This activity was greatest when 16:0-ACP was provided as a substrate, whereas no desaturation of the coenzyme A ester of this fatty acid was detected. In addition, delta 6 16:0-ACP desaturase activity in T. alata endosperm extracts was dependent on the presence of ferredoxin and molecular oxygen and was stimulated by catalase. To further characterize this enzyme, a cDNA encoding a diverged acyl-ACP desaturase was isolated from a T. alata endosperm cDNA library using polymerase chain reaction with degenerate oligonucleotides corresponding to conserved amino acid sequences in delta 9 stearoyl (18:0)- and delta 4 16:0-ACP desaturases. The primary structure of the mature peptide encoded by this cDNA shares 66% identity with the mature castor delta 9 18:0-ACP desaturase and 57% identity with the mature coriander delta 4 16:0-ACP desaturase. Extracts of Escherichia coli that express the T. alata cDNA catalyzed the delta 6 desaturation of 16:0-ACP. These results demonstrate that 16:1 delta 6 in T. alata endosperm is formed by the activity of a soluble delta 6 16:0-ACP desaturase that is structurally related to the delta 9 18:0- and delta 4 16:0-ACP desaturases. Implications of this work to an understanding of active site structures of acyl-ACP desaturases are discussed.

  14. RATING OF SOCIAL MEDIA MARKETING COMPETENCIES POSSESSED BY ENTREPRENEURS IN DELTA STATE, NIGERIA

    OpenAIRE

    Ezenwafor, J. I.; Onokpaunu, Michel O.; Nna-Emmanuel, Sarah W.

    2017-01-01

    The need for wide utilization of social media marketing for entrepreneurial development in Delta State necessitated this study which sought to determine how competent practicing entrepreneurs are for their use in Delta State. One research question guided the study. A survey research design was adopted. The population consisted of 200 entrepreneurs in Delta North Senatorial District of Delta State. A validated 22 item on a 5-point rating scale questionnaire was used for data collection. Mean a...

  15. Differential entrainment of neuroelectric delta oscillations in developmental dyslexia.

    Directory of Open Access Journals (Sweden)

    Fruzsina Soltész

    Full Text Available Oscillatory entrainment to the speech signal is important for language processing, but has not yet been studied in developmental disorders of language. Developmental dyslexia, a difficulty in acquiring efficient reading skills linked to difficulties with phonology (the sound structure of language, has been associated with behavioural entrainment deficits. It has been proposed that the phonological 'deficit' that characterises dyslexia across languages is related to impaired auditory entrainment to speech at lower frequencies via neuroelectric oscillations (<10 Hz, 'temporal sampling theory'. Impaired entrainment to temporal modulations at lower frequencies would affect the recovery of the prosodic and syllabic structure of speech. Here we investigated event-related oscillatory EEG activity and contingent negative variation (CNV to auditory rhythmic tone streams delivered at frequencies within the delta band (2 Hz, 1.5 Hz, relevant to sampling stressed syllables in speech. Given prior behavioural entrainment findings at these rates, we predicted functionally atypical entrainment of delta oscillations in dyslexia. Participants performed a rhythmic expectancy task, detecting occasional white noise targets interspersed with tones occurring regularly at rates of 2 Hz or 1.5 Hz. Both groups showed significant entrainment of delta oscillations to the rhythmic stimulus stream, however the strength of inter-trial delta phase coherence (ITC, 'phase locking' and the CNV were both significantly weaker in dyslexics, suggestive of weaker entrainment and less preparatory brain activity. Both ITC strength and CNV amplitude were significantly related to individual differences in language processing and reading. Additionally, the instantaneous phase of prestimulus delta oscillation predicted behavioural responding (response time for control participants only.

  16. Detailed quantification of delta subsidence, compaction and interaction with man-made structures: the case of the NCA airport, France

    Science.gov (United States)

    Cavalié, O.; Sladen, A.; Kelner, M.

    2015-09-01

    River deltas are dynamic coastal systems and their evolutions are closely monitored as it often concentrates vital natural resources for the surrounding areas. Many deltas worldwide experience subsidence due to geological processes (sediment loading and compaction) or human activities (groundwater or hydrocarbon extraction, land reclamation). This causes shoreline erosion or wetland loss which represent serious issues for the population. In this study we investigate the dynamic of the Var delta (France) where reclaimed lands over sea have been built to host the Nice côte d'Azur airport (NCA). Actually, the stability of this infrastructure is a permanent concern since, in 1979, a newly built extension of the runway platform collapsed in the sea, causing important damages. The project of land extension stopped, but the present airport platform is still located on reclaimed land. Factors that can trigger such catastrophic landslide are thought to be linked to the delta activity and the artificial airport platform load. We used, therefore, Envisat InSAR data to measure accurately the ground deformation of the area that includes the Var delta and NCA airport. Combining data from ascending and descending orbits, we estimated the east-west and vertical components of the deformation and obtained very accurate displacement rate (with a 1σ error of 0.25 mm yr-1). We found that nearly all the deformation is vertical and impacts the whole Var delta. The Var valley subsides at a very low rate (0.5-1 mm yr-1) but downstream the subsidence rate increases and a clear jump is observed at the transition with the reclaimed lands (1-2 mm yr-1). On average, the reclaimed lands subside at 3 mm yr-1. Since the subsidence rate increases in correlation with the sediment thickness, we interpret it as the compaction of the delta quaternary sedimentary wedge. In addition, three areas subside faster (between 5 and 10 mm yr-1), with one calling for more attention as it is the largest and

  17. Mu and delta opioid receptors oppositely regulate motor impulsivity in the signaled nose poke task.

    Directory of Open Access Journals (Sweden)

    Mary C Olmstead

    Full Text Available Impulsivity is a primary feature of many psychiatric disorders, most notably attention deficit hyperactivity disorder and drug addiction. Impulsivity includes a number of processes such as the inability to delay gratification, the inability to withhold a motor response, or acting before all of the relevant information is available. These processes are mediated by neural systems that include dopamine, serotonin, norepinephrine, glutamate and cannabinoids. We examine, for the first time, the role of opioid systems in impulsivity by testing whether inactivation of the mu- (Oprm1 or delta- (Oprd1 opioid receptor gene alters motor impulsivity in mice. Wild-type and knockout mice were examined on either a pure C57BL6/J (BL6 or a hybrid 50% C57Bl/6J-50% 129Sv/pas (HYB background. Mice were trained to respond for sucrose in a signaled nose poke task that provides independent measures of associative learning (responses to the reward-paired cue and motor impulsivity (premature responses. Oprm1 knockout mice displayed a remarkable decrease in motor impulsivity. This was observed on the two genetic backgrounds and did not result from impaired associative learning, as responses to the cue signaling reward did not differ across genotypes. Furthermore, mutant mice were insensitive to the effects of ethanol, which increased disinhibition and decreased conditioned responding in wild-type mice. In sharp contrast, mice lacking the Oprd1 gene were more impulsive than controls. Again, mutant animals showed no deficit in associative learning. Ethanol completely disrupted performance in these animals. Together, our results suggest that mu-opioid receptors enhance, whereas delta-opioid receptors inhibit, motor impulsivity. This reveals an unanticipated contribution of endogenous opioid receptor activity to disinhibition. In a broader context, these data suggest that alterations in mu- or delta-opioid receptor function may contribute to impulse control disorders.

  18. Phonon dispersion curves determination in (delta)-phase Pu-Ga alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wong, J; Clatterbuck, D; Occelli, F; Farber, D; Schwartz, A; Wall, M; Boro, C; Krisch, M; Beraud, A; Chiang, T; Xu, R; Hong, H; Zschack, P; Tamura, N

    2006-02-07

    We have designed and successfully employed a novel microbeam on large grain sample concept to conduct high resolution inelastic x-ray scattering (HRIXS) experiments to map the full phonon dispersion curves of an fcc {delta}-phase Pu-Ga alloy. This approach obviates experimental difficulties with conventional inelastic neutron scattering due to the high absorption cross section of the common {sup 239}Pu isotope and the non-availability of large (mm size) single crystal materials for Pu and its alloys. A classical Born von-Karman force constant model was used to model the experimental results, and no less than 4th nearest neighbor interactions had to be included to account for the observation. Several unusual features including, a large elastic anisotropy, a small shear elastic modulus, (C{sub 11}-C{sub 12})/2, a Kohn-like anomaly in the T{sub 1}[011] branch, and a pronounced softening of the T[111] branch towards the L point in the Brillouin are found. These features may be related to the phase transitions of plutonium and to strong coupling between the crystal structure and the 5f valence instabilities. Our results represent the first full phonon dispersions ever obtained for any Pu-bearing material, thus ending a 40-year quest for this fundamental data. The phonon data also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory (DMFT) calculations for {delta}-plutonium. We also conducted thermal diffuse scattering experiments to study the T(111) dispersion at low temperatures with an attempt to gain insight into bending of the T(111) branch in relationship to the {delta} {yields} {alpha}{prime} transformation.

  19. Oil and Security in Nigeria: The Niger Delta Crisis | Owolabi | Africa ...

    African Journals Online (AJOL)

    This paper examines oil and security in Nigeria, with special reference to the crisis-ravaged Niger Delta. Its focus on the Niger Delta and its festering crisis stems from that region's critical importance to Nigeria. As the nation's treasure base, the Niger Delta provides over 80 percent of government revenues, 95 percent of ...

  20. The coastal system of the Volta delta, Ghana : Strategies and opportunities for development

    NARCIS (Netherlands)

    Roest, Lambertus W.M.

    2018-01-01

    The Volta delta is a very dynamic environment, forming the interface between the Volta river and the Atlantic ocean. The delta is a home for many communities, settled both at the shorelines and more inland. Furthermore the delta provides great natural values and a habitat for many species.
    The

  1. Contrasting morphodynamics in alluvial fans and fan deltas: effect of the downstream boundary

    NARCIS (Netherlands)

    Dijk, M. van; Kleinhans, M.G.; Postma, G.; Kraal, E.

    2012-01-01

    Alluvial fans and fan deltas can, in principle, have exactly the same upstream conditions, but fan deltas by definition have ponding water at their downstream boundary. This ponding creates effects on the autogenic behaviour of fan deltas, such as backwater adaptation, mouth bars and backward

  2. Challenges and Approaches in River Delta Planning - report on training workshop

    NARCIS (Netherlands)

    Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

    2012-01-01

    River delta’s, like the Mekong Delta (Vietnam), Ganges-Brahmaputra Delta (Bangladesh), Irrawady (Myanmar) and Ciliwung Delta (Indonesia) are developing rapidly and characterized by large-scale urbanization and industrialization processes. They are facing serious planning challenges related to issues

  3. T-cell receptor gamma delta bearing cells in normal human skin

    NARCIS (Netherlands)

    Bos, J. D.; Teunissen, M. B.; Cairo, I.; Krieg, S. R.; Kapsenberg, M. L.; Das, P. K.; Borst, J.

    1990-01-01

    T-cell antigen receptors (TCR) are divided into common alpha beta and less common gamma delta types. In the murine skin, TCR gamma delta+ cells have been reported to form the great majority of epidermal T lymphocytes. We have examined the relative contribution of TCR alpha beta+ and TCR gamma delta+

  4. A new identification method for energetic ion {delta}E-E telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Cesar [Departamento de Fisica, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain); Institut fuer Experimentelle und Angewandte Physik, Christian-Albrechts, Universitaet zu Kiel, 24118 Kiel (Germany); Bronchalo, Enrique [Departamento de Fisica, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain); Departamento de Fisica y Arquitectura de Computadores, Universidad Miguel Hernandez, Avda. Universidad s/n, 03202 Elche, Alicante (Spain)], E-mail: ebronchalo@umh.es; Medina, Jose [Departamento de Fisica, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain)

    2007-11-21

    A new ion identification method for {delta}E-E telescopes is presented. The method works by counting data points under {delta}E(E) curves on {delta}E-E diagrams. These curves are obtained by simulating the telescope response to a flux of energetic ions. The method is checked against three published methods applied to several experimental data sets.

  5. Remote Sensing Monitoring Methods for Detecting Invasive Weed Coverage in Delta Waterways and Bay Marshlands

    Science.gov (United States)

    Potter, Christopher

    2018-01-01

    This presentation is part of the Independent Science Board of the State of California Delta Stewardship Council brown bag seminar series on the "How the Delta is Monitored", followed with a panel discussion. Various remote sensing approaches for aquatic vegetation will be reviewed. Key research and application issues with remote sensing monitoring in the Delta will be addressed.

  6. Effect of delta wing on the particle flow in a novel gas supersonic separator

    DEFF Research Database (Denmark)

    Wen, Chuang; Yang, Yan; Walther, Jens Honore

    2016-01-01

    The present work presents numerical simulations of the complex particle motion in a supersonic separator with a delta wing located in the supersonic flow. The effect of the delta wing on the strong swirling flow is analysed using the Discrete Particle Method. The results show that the delta wings...

  7. Grain-size sorting in grainflows at the lee side of deltas

    NARCIS (Netherlands)

    Kleinhans, M.G.

    2005-01-01

    The sorting of sediment mixtures at the lee slope of deltas (at the angle of repose) is studied with experiments in a narrow, deep flume with subaqueous Gilbert-type deltas using varied flow conditions and different sediment mixtures. Sediment deposition and sorting on the lee slope of the delta

  8. Plant delta 15N correlates with the transpiration efficiency of nitrogen acquisition in tropical trees.

    Science.gov (United States)

    Cernusak, Lucas A; Winter, Klaus; Turner, Benjamin L

    2009-11-01

    Based upon considerations of a theoretical model of (15)N/(14)N fractionation during steady-state nitrate uptake from soil, we hypothesized that, for plants grown in a common soil environment, whole-plant delta(15)N (deltaP) should vary as a function of the transpiration efficiency of nitrogen acquisition (F(N)/v) and the difference between deltaP and root delta(15)N (deltaP - deltaR). We tested these hypotheses with measurements of several tropical tree and liana species. Consistent with theoretical expectations, both F(N)/v and deltaP - deltaR were significant sources of variation in deltaP, and the relationship between deltaP and F(N)/v differed between non-N(2)-fixing and N(2)-fixing species. We interpret the correlation between deltaP and F(N)/v as resulting from variation in mineral nitrogen efflux-to-influx ratios across plasma membranes of root cells. These results provide a simple explanation of variation in delta(15)N of terrestrial plants and have implications for understanding nitrogen cycling in ecosystems.

  9. Distribution and Habitat Associations of California Black Rail (Laterallus jamaicensis cortuniculus in the Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Danika C. Tsao

    2015-12-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2015v13iss4art4Past studies documenting the distribution and status of state “Threatened" California black rail (Laterallus jamaicensis coturniculus; hereafter black rail have largely omitted the Sacramento—San Joaquin Delta (hereafter Delta. During March to May of 2009–2011, we conducted call–playback surveys to assess the status of the species within a wide range of wetland habitats of the central Delta region. We detected black rails at 21 of 107 discrete wetland sites, primarily on in-channel islands with dense cover. To better understand the habitat and land cover characteristics, we developed a model of habitat suitability from these occurrence data and a fine-scale vegetation and land use dataset using MaxEnt. We also evaluated differences in the size of wetlands at sites where black rails were detected versus where they were not. Through surveys and quantitative modeling, we found black rail presence differed from other regions within California and Arizona, in that it was positively associated with tall (1 to 5 m emergent vegetation interspersed with riparian shrubs. Specific plants correlated with black rail presence included emergent wetland (Bolboschoenus acutus, B. californicus, B. acutus, Typha angustifolia, T. latifolia, Phragmites australis and riparian (Salix exigua, S. lasiolepis, Rosa californica, Rubus discolor, Cornus sericea species. Median patch size was significantly larger and perimeter-to-area ratios were significantly lower at wetland sites where black rails were found. These results provide a preliminary characterization of black rail habitat in the Delta region and highlight the need for better understanding of this listed species’ population size and habitat use in the region, in light of anticipated climate change effects and proposed large-scale restoration in the Delta.

  10. Partial protective effect of CCR5-Delta 32 heterozygosity in a cohort of heterosexual Italian HIV-1 exposed uninfected individuals

    Directory of Open Access Journals (Sweden)

    Cauda Roberto

    2006-09-01

    Full Text Available Abstract Despite multiple sexual exposure to HIV-1 virus, some individuals remain HIV-1 seronegative (exposed seronegative, ESN. The mechanisms underlying this resistance remain still unclear, although a multifactorial pathogenesis can be hypothesised. Although several genetic factors have been related to HIV-1 resistance, the homozigosity for a mutation in CCR5 gene (the 32 bp deletion, i.e. CCR5-Delta32 allele is presently considered the most relevant one. In the present study we analysed the genotype at CCR5 locus of 30 Italian ESN individuals (case group who referred multiple unprotected heterosexual intercourse with HIV-1 seropositive partner(s, for at least two years. One hundred and twenty HIV-1 infected patients and 120 individuals representative of the general population were included as control groups. Twenty percent of ESN individuals had heterozygous CCR5-Delta 32 genotype, compared to 7.5% of HIV-1 seropositive and 10% of individuals from the general population, respectively. None of the analysed individuals had CCR5-Delta 32 homozygous genotype. Sequence analysis of the entire open reading frame of CCR5 was performed in all ESN subjects and no polymorphisms or mutations were identified. Moreover, we determined the distribution of C77G variant in CD45 gene, which has been previously related to HIV-1 infection susceptibility. The frequency of the C77G variant showed no significant difference between ESN subjects and the two control groups. In conclusion, our data show a significantly higher frequency of CCR5-Delta 32 heterozygous genotype (p = 0.04 among the Italian heterosexual ESN individuals compared to HIV-1 seropositive patients, suggesting a partial protective role of CCR5-Delta 32 heterozygosity in this cohort.

  11. Modeling pesticide loadings from the San Joaquin watershed into the Sacramento-San Joaquin Delta using SWAT

    Science.gov (United States)

    Chen, H.; Zhang, M.

    2016-12-01

    The Sacramento-San Joaquin Delta is an ecologically rich, hydrologically complex area that serves as the hub of California's water supply. However, pesticides have been routinely detected in the Delta waterways, with concentrations exceeding the benchmark for the protection of aquatic life. Pesticide loadings into the Delta are partially attributed to the San Joaquin watershed, a highly productive agricultural watershed located upstream. Therefore, this study aims to simulate pesticide loadings to the Delta by applying the Soil and Water Assessment Tool (SWAT) model to the San Joaquin watershed, under the support of the USDA-ARS Delta Area-Wide Pest Management Program. Pesticide use patterns in the San Joaquin watershed were characterized by combining the California Pesticide Use Reporting (PUR) database and GIS analysis. Sensitivity/uncertainty analyses and multi-site calibration were performed in the simulation of stream flow, sediment, and pesticide loads along the San Joaquin River. Model performance was evaluated using a combination of graphic and quantitative measures. Preliminary results indicated that stream flow was satisfactorily simulated along the San Joaquin River and the major eastern tributaries, whereas stream flow was less accurately simulated in the western tributaries, which are ephemeral small streams that peak during winter storm events and are mainly fed by irrigation return flow during the growing season. The most sensitive parameters to stream flow were CN2, SOL_AWC, HRU_SLP, SLSUBBSN, SLSOIL, GWQMN and GW_REVAP. Regionalization of parameters is important as the sensitivity of parameters vary significantly spatially. In terms of evaluation metric, NSE tended to overrate model performance when compared to PBIAS. Anticipated results will include (1) pesticide use pattern analysis, (2) calibration and validation of stream flow, sediment, and pesticide loads, and (3) characterization of spatial patterns and temporal trends of pesticide yield.

  12. Riders on the storm: selective tidal movements facilitate the spawning migration of threatened delta smelt in the San Francisco Estuary

    Science.gov (United States)

    Bennett, W.A.; Burau, Jon R.

    2015-01-01

    Migration strategies in estuarine fishes typically include behavioral adaptations for reducing energetic costs and mortality during travel to optimize reproductive success. The influence of tidal currents and water turbidity on individual movement behavior were investigated during the spawning migration of the threatened delta smelt, Hypomesus transpacificus, in the northern San Francisco Estuary, California, USA. Water current velocities and turbidity levels were measured concurrently with delta smelt occurrence at sites in the lower Sacramento River and San Joaquin River as turbidity increased due to first-flush winter rainstorms in January and December 2010. The presence/absence of fish at the shoal-channel interface and near the shoreline was quantified hourly over complete tidal cycles. Delta smelt were caught consistently at the shoal-channel interface during flood tides and near the shoreline during ebb tides in the turbid Sacramento River, but were rare in the clearer San Joaquin River. The apparent selective tidal movements by delta smelt would facilitate either maintaining position or moving upriver on flood tides, and minimizing advection down-estuary on ebb tides. These movements also may reflect responses to lateral gradients in water turbidity created by temporal lags in tidal velocities between the near-shore and mid-channel habitats. This migration strategy can minimize the energy spent swimming against strong river and tidal currents, as well as predation risks by remaining in turbid water. Selection pressure on individuals to remain in turbid water may underlie population-level observations suggesting that turbidity is a key habitat feature and cue initiating the delta smelt spawning migration.

  13. Implications for future survival of delta smelt from four climate change scenarios for the Sacramento–San Joaquin Delta, California

    Science.gov (United States)

    Brown, Larry R.; Bennett, William A.; Wagner, R. Wayne; Morgan-King, Tara; Knowles, Noah; Feyrer, Frederick; Schoellhamer, David H.; Stacey, Mark T.; Dettinger, Mike

    2013-01-01

    Changes in the position of the low salinity zone, a habitat suitability index, turbidity, and water temperature modeled from four 100-year scenarios of climate change were evaluated for possible effects on delta smelt Hypomesus transpacificus, which is endemic to the Sacramento–San Joaquin Delta. The persistence of delta smelt in much of its current habitat into the next century appears uncertain. By mid-century, the position of the low salinity zone in the fall and the habitat suitability index converged on values only observed during the worst droughts of the baseline period (1969–2000). Projected higher water temperatures would render waters historically inhabited by delta smelt near the confluence of the Sacramento and San Joaquin rivers largely uninhabitable. However, the scenarios of climate change are based on assumptions that require caution in the interpretation of the results. Projections like these provide managers with a useful tool for anticipating long-term challenges to managing fish populations and possibly adapting water management to ameliorate those challenges.

  14. 78 FR 22911 - Delta Air Lines, Inc., Reservation Sales and Customer Care Call Center, Seatac, WA; Delta Air...

    Science.gov (United States)

    2013-04-17

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-82,197; TA-W-82,197A] Delta Air... requested administrative reconsideration of the negative determination regarding workers' eligibility to... threatened with total or partial separation from employment on the date of certification through two years...

  15. Trophic gradients in a large-river delta: Ecological structure determined by connectivity gradients in the Danube Delta (Romania)

    NARCIS (Netherlands)

    Coops, H.; Buijse-Bogdan, L.L.; Buijse, A.D.; Constantinescu, A.; Covaliov, S.; Hanganu, J.; Ibelings, B.W.; Menting, G.; Navodaru, I.; Oosterberg, W.; Staras, M.; Torok, L.

    2008-01-01

    There are over 300 lakes interconnected by riverbranches and man-made canals in the Danube Delta (Romania). A multidisciplinary survey of these riverine lakes situated in large Wetland complexes was made comprising hydrological modelling, remote sensing and monitoring of water quality, plankton,

  16. (including travel dates) Proposed itinerary

    Indian Academy of Sciences (India)

    Ashok

    31 July to 22 August 2012 (including travel dates). Proposed itinerary: Arrival in Bangalore on 1 August. 1-5 August: Bangalore, Karnataka. Suggested institutions: Indian Institute of Science, Bangalore. St Johns Medical College & Hospital, Bangalore. Jawaharlal Nehru Centre, Bangalore. 6-8 August: Chennai, TN.

  17. Cohesive Sedimentary Processes on River-Dominated Deltas: New Perspectives from the Mississippi River Delta Front, Gulf of Mexico

    Science.gov (United States)

    Bentley, S. J.; Keller, G. P.; Obelcz, J.; Maloney, J. M.; Xu, K.; Georgiou, I. Y.; Miner, M. D.

    2016-12-01

    On river deltas dominated by proximal sediment accumulation (Mississippi, Huang He, others), the delta front region is commonly dominated by rapid accumulation of cohesive fluvial sediments, and mass-wasting processes that remobilize recently deposited sediments. Mass transport is preconditioned in sediments by high water content, biogenic gas production, over steepening, and is commonly triggered by strong wave loading and other processes. This understanding is based on extensive field studies in the 1970's and 80's. Recent studies of the Mississippi River Delta Front are yielding new perspectives on these processes, in a time of anthropogenically reduced sediment loads, rising sea level, and catastrophic deltaic land loss. We have synthesized many industry data sets collected since ca. 1980, and conducted new pilot field and modeling studies of sedimentary and morphodynamic processes. These efforts have yielded several key findings that diverge from historical understanding of this dynamic setting. First, delta distributary mouths have ceased seaward progradation, ending patterns that have been documented since the 18th century. Second, despite reduced sediment supply, offshore mass transport continues, yielding vertical displacements at rates of 1 m/y. This displacement is apparently forced by wave loading from storm events of near-annual return period, rather than major hurricanes that have been the focus of most previous studies. Third, core analysis indicates that this vertical displacement is occurring along failure planes >3 m in the seabed, rather than in more recently deposited sediments closer to the sediment-water interface. These seabed morphodynamics have the potential to destabilize both nearshore navigation infrastructure, and seabed hydrocarbon infrastructure offshore. As well, these findings raise more questions regarding the future seabed evolution offshore of major river deltas, in response to anthropogenic and climatic forcing.

  18. Alopecia in a viable phospholipase C delta 1 and phospholipase C delta 3 double mutant.

    Directory of Open Access Journals (Sweden)

    Fabian Runkel

    Full Text Available BACKGROUND: Inositol 1,4,5trisphosphate (IP(3 and diacylglycerol (DAG are important intracellular signalling molecules in various tissues. They are generated by the phospholipase C family of enzymes, of which phospholipase C delta (PLCD forms one class. Studies with functional inactivation of Plcd isozyme encoding genes in mice have revealed that loss of both Plcd1 and Plcd3 causes early embryonic death. Inactivation of Plcd1 alone causes loss of hair (alopecia, whereas inactivation of Plcd3 alone has no apparent phenotypic effect. To investigate a possible synergy of Plcd1 and Plcd3 in postnatal mice, novel mutations of these genes compatible with life after birth need to be found. METHODOLOGY/PRINCIPAL FINDINGS: We characterise a novel mouse mutant with a spontaneously arisen mutation in Plcd3 (Plcd3(mNab that resulted from the insertion of an intracisternal A particle (IAP into intron 2 of the Plcd3 gene. This mutation leads to the predominant expression of a truncated PLCD3 protein lacking the N-terminal PH domain. C3H mice that carry one or two mutant Plcd3(mNab alleles are phenotypically normal. However, the presence of one Plcd3(mNab allele exacerbates the alopecia caused by the loss of functional Plcd1 in Del(9olt1Pas mutant mice with respect to the number of hair follicles affected and the body region involved. Mice double homozygous for both the Del(9olt1Pas and the Plcd3(mNab mutations survive for several weeks and exhibit total alopecia associated with fragile hair shafts showing altered expression of some structural genes and shortened phases of proliferation in hair follicle matrix cells. CONCLUSIONS/SIGNIFICANCE: The Plcd3(mNab mutation is a novel hypomorphic mutation of Plcd3. Our investigations suggest that Plcd1 and Plcd3 have synergistic effects on the murine hair follicle in specific regions of the body surface.

  19. Erosion of the Mekong delta: the role of human activities

    Science.gov (United States)

    Anthony, E.; Dussouillez, P.; Goichot, M.; Brunier, G.; Dolique, F.; Nguyen, V.; Loisel, H.; Mangin, A.; Vantrepotte, V.

    2013-12-01

    River deltas are threatened by dams, dykes, flow channelling, and aggregate extraction. These activities outweigh climate change and sea-level rise in causing delta vulnerability1, and will aggravate the impacts to be expected from these effects2. We show here from analysis of: (1) delta channel morphology and sediment budgets, and (2) satellite imagery, that the Mekong delta, considered as the world's third largest, and hitherto strongly prograding, is now in a phase of large-scale erosion. We discuss the mechanistic links involved in erosion and the way these are related to human activities. High-resolution (2.5 m) SPOT 5 images for the years 2003, 2007, 2011/12 covering 405 km of the delta shoreline show an overall retreat rate of over 8 m a year. 75% of the analysed shoreline, i.e., the muddy western sector, is now retreating at rates exceeding 50 m a year in places. The sandy river-mouth sector maintains a semblance of stability, but with strong variations. We attribute erosion to a cascade of morphosedimentary changes linked to sediment mining from the deltaic channels and upstream dam interception. We estimated from Meris satellite imagery an annual 5% decrease in surface suspended concentrations exiting at the mouths of the Mekong over the period 2003-2011 that may reflect increased trapping of mud behind dams in China. We also infer modification of river-mouth and coastal mud storage patterns resulting from a loss of ca. 200 million m3 of delta channel sediments between 1998 and 2008 from aggregate extraction. Dykes have been shown to result in increased channel flow velocities during the high-discharge monsoon season, favouring further channel deepening3. Stronger river-mouth outflow velocities during this season may be leading to export of a greater proportion of mud far offshore of the coastal longshore transport corridor that ensured mud supply to, and past progradation of, the muddy western coast. In contrast, greater seawater penetration in the

  20. Within-canopy and ozone fumigation effects on delta13C and Delta18O in adult beech (Fagus sylvatica) trees: relation to meteorological and gas exchange parameters.

    Science.gov (United States)

    Gessler, Arthur; Löw, Markus; Heerdt, Christian; de Beeck, Maarten Op; Schumacher, Johannes; Grams, Thorsten E E; Bahnweg, Günther; Ceulemans, Reinhart; Werner, Herbert; Matyssek, Rainer; Rennenberg, Heinz; Haberer, Kristine

    2009-11-01

    In this study, the effects of different light intensities either in direct sunlight or in the shade crown of adult beech (Fagus sylvatica L.) trees on delta13C and Delta18O were determined under ambient (1 x O3) and twice-ambient (2 x O3) atmospheric ozone concentrations during two consecutive years (2003 and 2004). We analysed the isotopic composition in leaf bulk, leaf cellulose, phloem and xylem material and related the results to (a) meteorological data (air temperature, T and relative humidity, RH), (b) leaf gas exchange measurements (stomatal conductance, g(s); transpiration rate, E; and maximum photosynthetic activity, A(max)) and (c) the outcome of a steady-state evaporative enrichment model. Delta13C was significantly lower in the shade than in the sun crown in all plant materials, whilst Delta18O was increased significantly in the shade than in the sun crown in bulk material and cellulose. Elevated ozone had no effect on delta13C, although Delta18O was influenced by ozone to varied degrees during single months. We observed significant seasonal changes for both parameters, especially in 2004, and also significant differences between the study years. Relating the findings to meteorological data and gas exchange parameters, we conclude that the differences in Delta18O between the sun and the shade crown were predominantly caused by the Péclet effect. This assumption was supported by the modelled Delta18O values for leaf cellulose. It was demonstrated that independent of RH, light-dependent reduction of stomatal conductance (and thus transpiration) and of A(max) can drive the pattern of Delta18O increase with the concomitant decrease of delta13C in the shade crown. The effect of doubling ozone levels on time-integrated stomatal conductance and transpiration as indicated by the combined analysis of Delta18O and delta13C was much lower than the influence caused by the light exposure.

  1. Theory including future not excluded

    DEFF Research Database (Denmark)

    Nagao, K.; Nielsen, H.B.

    2013-01-01

    We study a complex action theory (CAT) whose path runs over not only past but also future. We show that, if we regard a matrix element defined in terms of the future state at time T and the past state at time TA as an expectation value in the CAT, then we are allowed to have the Heisenberg equation......, Ehrenfest's theorem, and the conserved probability current density. In addition,we showthat the expectation value at the present time t of a future-included theory for large T - t and large t - T corresponds to that of a future-not-included theory with a proper inner product for large t - T. Hence, the CAT...

  2. Displacement waves in La2CuO(4-delta) and La(1.85)Sr(0.15)CuO(4-delta)

    Science.gov (United States)

    Kajitani, Tsuyoshi; Onozuka, Takashi; Yamaguchi, Yasuo; Hirabayashi, Makoto; Syono, Yasuhiko

    1987-11-01

    Structural investigation of orthorhombic La2CuO(4-delta) and La(1.85)Sr(0.15)CuO(4-delta) was carried out by means of X-ray and neutron diffraction on the basis of the space group Cmmm. The periodic expansion/contraction type distortion of CuO6 octahedra was found in both orthorhombic compounds. The distortion is nearly one-dimensional in La2CuO(4-delta) but is two-dimensional in La(1.85)Sr(0.15)CuO(4-delta). The existence of a charge-density wave is highly possible in the structures.

  3. Modern Geophysical Techniques for Constructing a 3D Geological Model on the Nile Delta, Egypt

    OpenAIRE

    Barakat, Moataz Khairy Ahmad

    2010-01-01

    The Nile Delta can be considered the earliest known delta in the world. It was described by Herodotus in the 5th Century AC. The Nile Delta (Ta-Mehet) in Hieroglyphic language means the land of the estuary water. It is one of the oldest intensely cultivated areas on the earth. The Nile Delta is illustrated to be an arcuate delta (arcshaped), as it resembles a triangle or lotus flower when seen from above. The name has been derived from the letter Thelta of the Greek alphabet. In comparison to...

  4. Investigations of (Delta)14C, (delta)13C, and (delta)15N in vertebrae of white shark (Carcharodon carcharias) from the eastern North Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, L A; Andrews, A H; Cailliet, G M; Brown, T A; Coale, K H

    2006-06-08

    The white shark (Carcharodon carcharias) has a complex life history that is characterized by large scale movements and a highly variable diet. Estimates of age and growth for the white shark from the eastern North Pacific Ocean indicate they have a slow growth rate and a relatively high longevity. Age, growth, and longevity estimates useful for stock assessment and fishery models, however, require some form of validation. By counting vertebral growth band pairs, ages can be estimated, but because not all sharks deposit annual growth bands and many are not easily discernable, it is necessary to validate growth band periodicity with an independent method. Radiocarbon ({sup 14}C) age validation uses the discrete {sup 14}C signal produced from thermonuclear testing in the 1950s and 1960s that is retained in skeletal structures as a time-specific marker. Growth band pairs in vertebrae, estimated as annual and spanning the 1930s to 1990s, were analyzed for {Delta}{sup 14}C and stable carbon and nitrogen isotopes ({delta}{sup 13}C and {delta}{sup 15}N). The aim of this study was to evaluate the utility of {sup 14}C age validation for a wide-ranging species with a complex life history and to use stable isotope measurements in vertebrae as a means of resolving complexity introduced into the {sup 14}C chronology by ontogenetic shifts in diet and habitat. Stable isotopes provided useful trophic position information; however, validation of age estimates was confounded by what may have been some combination of the dietary source of carbon to the vertebrae, large-scale movement patterns, and steep {sup 14}C gradients with depth in the eastern North Pacific Ocean.

  5. SPATIO-TEMPORAL VARIATION OF MERCURY IN BIDYADHARI RIVER OF SUNDARBAN DELTA, INDIA

    Directory of Open Access Journals (Sweden)

    Shivaji Bhattacharya

    2014-06-01

    Full Text Available Bidyadhari river originates in Nadia district of West Bengal, India and then flows through North 24 Parganas district and now serves as a sewage and excess rainwater outlet from the city of Kolkata and adjacent area, which ultimately empties at the Bay of Bengal through the Indian Sundarban delta. Four different stations situated around the course of the river at considerable distances have been selected from the outfall of sewage canals at Kulti-Ghushighata (S1, where metropolitan sewages discharged and mixed up into water of Bidyadhari river, which ultimately carried through this river via stations Malancha (S2, Kanmari (S3 to Dhamakhali (S4, just before the river confluences with the larger Raimangal river at northern Sundarban delta. This study was conducted to estimate total mercury (Hg concentration in waters (during high tides and ebb tides and sediments of Bidyadhari river in pre-monsoon, monsoon and post-monsoon seasons during the period from March, 2012 to February, 2013 at those stations. It is revealed from the estimated data that agricultural runoff, sewage, effluents from various industries and Kolkata metropolitan, Salt Lake City and adjacent areas of North 24 Parganas district carried and discharged in Bidyadhari river through sewage canals are not so high in mercury content for sediment contamination but alarming in respect of water quality, which crosses the permissible limit of Hg for consumption (0.001 ppm in wide range of areas at Kanmari and Dhamakhali around the estuary. Enhancement of Hg level in this river water and transportation of the metal through tidal effects to and fro mangrove land of Sundarban may be dangerous for aquatic lives and supposed to be grave concern for the ecology of the Sundarban delta including humans

  6. Ambient Air Pollution Monitoring Network Over Alexandria City And The Nile DELTA, Egypt

    International Nuclear Information System (INIS)

    El Raey, M.; Shalaby, E.; Guirguis, S.; Ghatass, Z.; Said, H.H.; Zahran, A.; Rashad, M.; Sivertsen, B.

    2007-01-01

    The Egyptian Environmental Affairs Agency (EEAA) has established a National Air Pollution Network for Egypt. A part of this network covers Alexandria and the Nile delta region and is being operated by the Institute of Graduate Studies and Research (IGSR), University of Alexandria. This paper presents a description of the network, the QA/QC program as well as results from automatic monitors and manually operated instruments . . Preliminary interpretations and implications of air pollution levels have also been discussed. The network monitors ambient air quality indicators including SO 2 , NO 2 , CO, O 3 and PM 10 . The sites for measurements were selected to represent industrial, traffic and domestic sources. Eight stations are established over Alexandria City and seven stations are distributed over Nile delta major cities Damanhur, Kafr EI-Dawwar, Kafr EI-Zayat, Mahala, Tanta, Damietta and Mansoura. The results represent the first long term air quality data for the southern Mediterranean region, which have been properly quality assured and quality controlled. The main results indicate that measured NO 2 concentrations have not exceeded the national air quality limit (AQL) values given for Egypt. The same occurred for SO 2 except at one site located in Kafr Elzayat in the Delta, where large emissions from brick factories impact the site. The 8-hour average CO concentrations were exceeded at a few occasions. PM 10 concentrations have been identified as the major air pollution problem. Concentrations exceeding 70 μm 3 (AQL) have been observed over many sites most of the time. It is suggested that a strong program for tree cultivation on the western desert may be essential for protection

  7. Effects of the proposed California WaterFix North Delta Diversion on flow reversals and entrainment of juvenile Chinook salmon (Oncorhynchus tshawytscha) into Georgiana Slough and the Delta Cross Channel, northern California

    Science.gov (United States)

    Perry, Russell W.; Romine, Jason G.; Pope, Adam C.; Evans, Scott D.

    2018-02-27

    evaluate the effect of the NDD bypass rules on flow reversals of the Sacramento River downstream of Georgiana Slough. The NDD bypass rules are a set of operational criteria designed to minimize upstream transport of fish into Georgiana Slough and the DCC, and were developed based on previous studies showing that the magnitude and duration of flow reversals increase the proportion of fish entering Georgiana Slough and the DCC. We estimated the frequency and duration of reverse-flow conditions of the Sacramento River downstream of Georgiana Slough under each of the prescribed minimum bypass flows described in the NDD bypass rules. To accommodate adaptive levels of protection during different times of year when juvenile salmon are migrating through the Delta, the NDD bypass rules prescribe a series of minimum allowable bypass flows that vary depending on (1) month of the year, and (2) progressively decreasing levels of protection following a pulse flow event.We determined that the NDD bypass rules increased the frequency and duration of reverse flows of the Sacramento River downstream of Georgiana Slough, with the magnitude of increase varying among scenarios. Constant low-level pumping, the most protective bypass rule that limits diversion to 10 percent of the maximum diversion and is implemented following a pulse-flow event, led to the smallest increase in frequency and duration of flow reversals. In contrast, we found that some scenarios led to sizeable increases in the fraction of the day with reverse flow. The conditions under which the proportion of the day with reverse flow can increase by greater than or equal to 10 percentage points between October and June, when juvenile salmon are present in the Delta, include October–November bypass rules and level-3 post-pulse operations during December–June. These conditions would be expected to increase the proportion of juvenile salmon entering the interior Delta through Georgiana Slough.In the second analysis, we assessed

  8. On new physics in $\\Delta \\Gamma_d$

    CERN Document Server

    Bobeth, Christoph; Lenz, Alexander; Pecjak, Ben; Tetlalmatzi-Xolocotzi, Gilberto

    2014-06-09

    Motivated by the recent measurement of the dimuon asymmetry by the D{\\O} collaboration, which could be interpreted as an enhanced decay rate difference in the neutral $B_d$-meson system, we investigate the possible size of new-physics contributions to $\\Delta \\Gamma_d$. In particular, we perform model-independent studies of non-standard effects associated to the dimension-six current-current operators $(\\bar{d} p)(\\bar p^{\\hspace{0.25mm}\\prime} b)$ with $p,p^\\prime= u,c$ as well as $(\\bar{d}b) (\\bar\\tau\\tau)$. In both cases we find that for certain flavour or Lorentz structures of the operators sizable deviations of $\\Delta \\Gamma_d$ away from the Standard Model expectation cannot be excluded in a model-independent fashion.

  9. HDVDB: a data warehouse for hepatitis delta virus.

    Science.gov (United States)

    Singh, Sarita; Gupta, Sunil Kumar; Nischal, Anuradha; Pant, Kamlesh Kumar; Seth, Prahlad Kishore

    2015-01-01

    Hepatitis Delta Virus (HDV) is an RNA virus and causes delta hepatitis in humans. Although a lot of data is available for HDV, but retrieval of information is a complicated task. Current web database 'HDVDB' provides a comprehensive web-resource for HDV. The database is basically concerned with basic information about HDV and disease caused by this virus, genome structure, pathogenesis, epidemiology, symptoms and prevention, etc. Database also supplies sequence data and bibliographic information about HDV. A tool 'siHDV Predict' to design the effective siRNA molecule to control the activity of HDV, is also integrated in database. It is a user friendly information system available at public domain and provides annotated information about HDV for research scholars, scientists, pharma industry people for further study.

  10. Methods for deconvolving sparse positive delta function series

    International Nuclear Information System (INIS)

    Trussell, H.J.; Schwalbe, L.A.

    1981-01-01

    Sparse delta function series occur as data in many chemical analyses and seismic methods. These original data are often sufficiently degraded by the recording instrument response that the individual delta function peaks are difficult to distinguish and measure. A method, which has been used to measure these peaks, is to fit a parameterized model by a nonlinear least-squares fitting algorithm. The deconvolution approaches described have the advantage of not requiring a parameterized point spread function, nor do they expect a fixed number of peaks. Two new methods are presented. The maximum power technique is reviewed. A maximum a posteriori technique is introduced. Results on both simulated and real data by the two methods are presented. The characteristics of the data can determine which method gives superior results. 5 figures

  11. Flood mitigation strategies for the Red River Delta

    International Nuclear Information System (INIS)

    Hansson, K.; Ekenberg, L.

    2002-01-01

    The increase of natural disasters and especially floods are escalating economical losses. Governments of both developed and developing countries are therefore concerned with increasing post-disaster liabilities in aiding recovery, repairing infrastructure damage and compensation of victims. In particular, governments of developing countries are ill prepared to cover the financial losses of disasters. Moreover, they often experience difficulties in raising funds for the recovery process. In this article, we identify possible policy strategies for coping with complex environmental and social decisions with flood risk involved; using The Red River Delta in Vietnam as a case for investigating various strategies. The paper is concluded with an outline of a model used for policy scenario simulations as well as some very preliminary results from evaluation of three possible policy strategies for The Red River Delta. (author)

  12. Measuring $CP$ violation with $\\Delta A_{CP}$ at LHCb

    CERN Document Server

    Pearce, Alex

    2014-01-01

    The control of systematic uncertainties is a key component of many analyses performed at the Large Hadron Collider, and will only become more important as more data are taken during Run II. Many of the CP measurements performed using the LHCb detector have statistical precisions below the per cent level, and so particular care must be taken in this area. One technique for dealing with the various production and detection asymmetries which can mask the physics asymmetry of interest, and increase the measurement’s systematic uncertainty, is $\\Delta A_{CP}$ . The application of $\\Delta A_{CP}$ in three separate LHCb analyses of $D^{0}$ and $\\Lambda_{b}^{0}$ decays will be discussed, along with prospects for applying the technique to $\\Lambda_{c}^{+}$ decays.

  13. The Legal Status of the Danube Delta Biosphere Reservation

    Directory of Open Access Journals (Sweden)

    Florica Brasoveanu

    2012-05-01

    Full Text Available In recent years the world has become aware that natural resources are not inexhaustible, that manyspecies are threatened with extinction and that is is necessary to strive for judicious use of natural resources tofulfill the needs of the present without compromising the ability of future generations to meet their needs(principle of sustainable development. To conserve species and habitats protected areas have beenestablished worldwide. The protected area is a geographically defined area, with rare natural elements and / orendangered species, regulated and managed in order to achieve specific conservation objectives. Althoughranked Europe's second in size (after the Volga River and the 20th in the world, because of the rich landscapeand wildlife, with the birds ranked most important, the Danube Delta has a very special interest scientificallyas it is a natural laboratory of forming delta, tourism and economic ecosystems, through its renewable naturalresources of which the most important resources are living aquatic resources.

  14. D2 Delta Robot Structural Design and Kinematics Analysis

    Science.gov (United States)

    Yang, Xudong; wang, Song; Dong, Yu; Yang, Hai

    2017-12-01

    In this paper, a new type of Delta robot with only two degrees of freedom is proposed on the basis of multi - degree - of - freedom delta robot. In order to meet our application requirements, we have carried out structural design and analysis of the robot. Through SolidWorks modeling, combined with 3D printing technology to determine the final robot structure. In order to achieve the precise control of the robot, the kinematics analysis of the robot was carried out. The SimMechanics toolbox of MATLAB is used to establish the mechanism model, and the kinematics mathematical model is used to simulate the robot motion control in Matlab environment. Finally, according to the design mechanism, the working space of the robot is drawn by the graphic method, which lays the foundation for the motion control of the subsequent robot.

  15. The delta18O composition of Antarctic coastal current waters

    International Nuclear Information System (INIS)

    Frew, R.; Heywood, K.; Dennis, P.

    1997-01-01

    The varying proportions of 18 O to 16 O in sea water provide an oceanographic trace like salinity, but with an extra degree of freedom: salt is a tracer for the oceanic fluid, whereas the isotopic composition is a tracer specifically for the water component of that fluid. Hydrogen and oxygen isotopes are the variables most intimately related to the water component in the sea, therefore thay furnish a direct link to the water in the atmosphere and on continents and to the precipitation cycle which caused the salinity changes. The ratio of 18 O to 16 O (delta 18 O) ot waters is a powerful tracer in polar regions where sea and glacial ice processes decouple delta 18 O from salinity. Here we present observations from a significant but relatively unexplored component of the Southern Ocean current system, the Antarctic Coastal Current, and its associated Antarctic Slope Front. (author)

  16. A pilot project: Antioch Delta Cove, Antioch, California

    International Nuclear Information System (INIS)

    Minder, M.

    1994-01-01

    The project involves the restoration of the Hickmott cannery site, comprising approximately 15 acres (three five acre parcels) located on the Delta in inter-city Antioch. Hickmott Foods, Inc., operated a fruit and vegetable cannery between 1905 and the early 1970's, during which time tomato skins, peach and apricot pits, and asparagus butts were discharged on the site. The decaying fruit pits have caused cyanide contamination. Additionally, the site contains some petroleum hydrocarbon contamination as well as gypsum board contamination, apparently from nearby manufacturing operations. The Antioch Delta Cove Pilot shows how interested parties can work together to clean up contaminated sites and use the clean up process to stimulate technology transfer. The Antioch project is a blueprint that can be replicated at other sites across California

  17. Predictability of surface currents and fronts off the Mississippi Delta

    International Nuclear Information System (INIS)

    Walker, N.D.; Rouse, L.J.; Wiseman, W.J.

    2001-01-01

    The dynamic coastal region of the lower Mississippi River was examined under varying conditions of wind, river discharge and circulation patterns of the Gulf of Mexico. Nearly 7,000 deep-sea merchant vessels enter the port complex each year and the area boasts the highest concentration of offshore drilling rigs, rendering the Mississippi delta and adjacent coastal areas vulnerable to risk from oil spills. Satellite imagery has been useful in tracking movements of the Mississippi river plume as recognizable turbidity and temperature fronts are formed where river waters encounter ambient shelf waters. Oil spill modelers often base their predictions of oil movement on the surface wind field and surface currents, but past studies have indicated that this can be overly simplistic in regions affected by river flow because river fronts have significant control over the movement of oil in opposition to prevailing winds. Frontal zones, such as those found where river waters meet oceanic waters, are characterized by strong convergence of surface flow. These frontal zones can provide large and efficient traps or natural booms for spilled oil. In an effort to facilitate cleanup operations, this study made use of the National Ocean and Atmospheric Administration (NOAA) AVHRR satellite imagery of temperature and reflectance to study front locations and their variability in space and time. The main objectives were to quantify surface temperature structure and locations of fronts throughout the year using satellite image data, to map the structure of the Mississippi sediment plume and to assess the forcing factors responsible for its variability over space and time. The final objective was to use in-situ measurements of surface currents together with satellite image data to better understand surface flow in this region of strong and variable currents. It was concluded that the main factors controlling circulation in the Mississippi River outflow region are river discharge and

  18. EAARL Coastal Topography-Pearl River Delta 2008: First Surface

    Science.gov (United States)

    Nayegandhi, Amar; Brock, John C.; Wright, C. Wayne; Miner, Michael D.; Michael, D.; Yates, Xan; Bonisteel, Jamie M.

    2009-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived first surface (FS) topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the University of New Orleans (UNO), Pontchartrain Institute for Environmental Sciences (PIES), New Orleans, LA; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of a portion of the Pearl River Delta in Louisiana and Mississippi, acquired March 9-11, 2008. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the

  19. EAARL Coastal Topography-Pearl River Delta 2008: Bare Earth

    Science.gov (United States)

    Nayegandhi, Amar; Brock, John C.; Wright, C. Wayne; Miner, Michael D.; Yates, Xan; Bonisteel, Jamie M.

    2009-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived bare earth (BE) topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the University of New Orleans (UNO), Pontchartrain Institute for Environmental Sciences (PIES), New Orleans, LA; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of a portion of the Pearl River Delta in Louisiana and Mississippi, acquired March 9-11, 2008. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the

  20. Bedrock hillslopes to deltas: New insights into landscape mechanics

    Science.gov (United States)

    Lamb, M. P.

    2012-12-01

    A powerful record of environmental history on Earth and other planets is preserved in landscapes and sedimentary deposits formed by erosion, transport and deposition of sediment. To understand this record and predict future landscape change, we need mechanistic theories for transport processes and morphodynamics. Significant progress has been made to develop and test transport laws in some settings including soil-mantled landscapes and modest gradient alluvial channels where conventional hydraulic and sediment-transport theories apply. Fundamental opportunities exist, however, to explore the physical limits of existing theories and develop new theories at the frontier of our knowledge base. In this presentation, I will describe recent case studies from sediment-source areas to depositional sinks designed to test the limits of existing transport theories and identify transitions in dominant geomorphic processes by pushing to steeper slopes, greater discharges, and dynamic boundary conditions. First, field measurements, laboratory experiments and theory suggest that sediment transport on steep, rocky hillslopes is different than on soil mantled landscapes, and may be controlled by vegetation dams and sediment release following wildfire. Second, laboratory experiments show that grain stability is enhanced in steep mountain channels compared to moderate gradient channels due to the coincident change in the ratio of flow depth to grain size, until the threshold for mass failure is surpassed. Third, field observations and theory indicate that canyons can be cut by extreme floods at rates that exceed typical river-incision rates by many orders of magnitude due to the transition from abrasion to plucking and toppling of jointed rock, with implications for megafloods on Mars. Finally, numerical modeling, laboratory experiments, and field work show that coastal rivers are coupled to their offshore plumes, and that this coupling may determine the size of deltas. These case