Sample records for acacia dealbata nas

  1. Biomass and nutrient mass of Acacia dealbata and Eucalyptus globulus bioenergy plantations

    Treesearch

    Timothy J. Albaugh; Rafael A. Rubilar; Chris A. Maier; Eduardo A. Acuña; Rachel L. Cook

    2017-01-01

    We quantified biomass and nutrient accumulation of Acacia dealbata Link and Eucalyptus globulus Labill. planted at stem densities of 5000 and 15000 ha-1 in a bioenergy plantation in Chile. We tested the hypotheses that species and stocking will not affect biomass or nutrient accumulation. Species and...

  2. Does Acacia dealbata express shade tolerance in Mediterranean forest ecosystems of South America?

    PubMed Central

    Aguilera, Narciso; Sanhueza, Carolina; Guedes, Lubia M; Becerra, José; Carrasco, Sebastián; Hernández, Víctor

    2015-01-01

    The distribution of Acacia dealbata Link (Fabaceae) in its non-native range is associated with disturbed areas. However, the possibility that it can penetrate the native forest during the invasion process cannot be ruled out. This statement is supported by the fact that this species has been experimentally established successfully under the canopy of native forest. Nonetheless, it is unknown whether A. dealbata can express shade tolerance traits to help increase its invasive potential. We investigated the shade tolerance of A. dealbata under the canopy of two native forests and one non-native for three consecutive years, as well as its early growth and photosynthetic performance at low light intensities (9, 30, and 70 μmol m−2sec−1) under controlled conditions. We found many A. dealbata plants surviving and growing under the canopy of native and non-native forests. The number of plants of this invasive species remained almost constant under the canopy of native forests during the years of study. However, the largest number of A. dealbata plants was found under the canopy of non-native forest. In every case, the distribution pattern varied with a highest density of plants in forest edges decreasing progressively toward the inside. Germination and early growth of A. dealbata were slow but successful at three low light intensities tested under controlled conditions. For all tested light regimes, we observed that in this species, most of the energy was dissipated by photochemical processes, in accordance with the high photosynthetic rates that this plant showed, despite the really low light intensities under which it was grown. Our study reveals that A. dealbata expressed shade tolerance traits under the canopy of native and non-native forests. This behavior is supported by the efficient photosynthetic performance that A. dealbata showed at low light intensities. Therefore, these results suggest that Mediterranean forest ecosystems of South America can become

  3. Whole-tree transpiration and water-use partitioning between Eucalyptus nitens and Acacia dealbata weeds in a short-rotation plantation in northeastern Tasmania.

    PubMed

    Hunt, Mark A.; Beadle, Christopher L.

    1998-01-01

    Whole-tree water use in 4- and 8-year-old plantations of Eucalyptus nitens Deane and Maiden (ex Maiden) in the presence and absence of Acacia dealbata Link. weeds was estimated by the heat pulse velocity technique during a six-week summer period. Maximum sap velocities were recorded between 5 and 15 mm under the cambium for both eucalypt and acacia trees, and marked radial and axial variations in sap velocity were observed. The latter source of variation was most pronounced in mixed stands where crowns were asymmetrical. Mean daily sap flux ranged from 1.4 to 103.6 l day(-1) for eucalypts and from < 0.1 to 8.4 l day(-1) for acacias. Stem diameter explained 98% of the variation in sapwood area for E. nitens and 89% for A. dealbata, and was determined to be a suitable parameter for scaling water use from the tree to stand level. Plot transpiration varied from 1.4 to 2.8 mm day(-1) in mixed 8-year-old plots and was 0.85 mm day(-1) in a mixed 4-year-old plot. The degree of A. dealbata infestation was associated with absolute plot water use and regression models predicted that, in the absence of acacia competition, plot water use for the 8-year-old stand would approach 5-6 mm day(-1) during the growing season.

  4. Livelihood benefits and costs from an invasive alien tree (Acacia dealbata) to rural communities in the Eastern Cape, South Africa.

    PubMed

    Ngorima, A; Shackleton, C M

    2018-05-31

    The negative effects of invasive alien species (IAS) are increasingly invoked to justify widespread and usually top-down approaches for their management or eradication. However, very little of the research or discourse is based on investigating local perceptions, uses and struggles with IAS, and how their presence influences and changes local livelihoods. The objective of this study was to assess the perceptions and livelihood uses of Acacia dealbata by local communities at three localities in the montane grasslands of the Eastern Cape, South Africa, using a combination of random household interviews, focus group discussions and participatory tools. We calculated direct-use values for each product and household (based on quantity used and local prices) and disaggregated these by gender of the household head and wealth quartiles. The results revealed the dualistic role of A. dealbata in local livelihoods. On the one hand, A. dealbata was widely used for firewood (100% of households), tools (77%) and construction timber (73%), with limited use for traditional medicines and forage. The cumulative value of approximately ZAR 2870 (±US$224) per household per year (across all households) represents considerable cash saving to households, most of whom are quite poor by national and international measures. On the other hand, the increasing extent of A. dealbata (93% said it was increasing) exacerbates local household vulnerability though reported reductions in cultivated areas, crop yields and forage production, and allegedly higher risks of crime. This quandary is well encapsulated by the considerable majority of respondents (84%) not wanting higher extents and densities of A. dealbata, but an equally high majority not wanting its total removal from local landscapes. Most respondents disliked A. dealbata in fields, close to homesteads or along primary access routes, and were more tolerant of it away from such sites. Institutional and use dynamics have varied over several

  5. Two invasive acacia species secure generalist pollinators in invaded communities

    NASA Astrophysics Data System (ADS)

    Montesinos, Daniel; Castro, Sílvia; Rodríguez-Echeverría, Susana

    2016-07-01

    Exotic entomophilous plants need to establish effective pollinator interactions in order to succeed after being introduced into a new community, particularly if they are obligatory outbreeders. By establishing these novel interactions in the new non-native range, invasive plants are hypothesised to drive changes in the composition and functioning of the native pollinator community, with potential impacts on the pollination biology of native co-flowering plants. We used two different sites in Portugal, each invaded by a different acacia species, to assess whether two native Australian trees, Acacia dealbata and Acacia longifolia, were able to recruit pollinators in Portugal, and whether the pollinator community visiting acacia trees differed from the pollinator communities interacting with native co-flowering plants. Our results indicate that in the invaded range of Portugal both acacia species were able to establish novel mutualistic interactions, predominantly with generalist pollinators. For each of the two studied sites, only two other co-occurring native plant species presented partially overlapping phenologies. We observed significant differences in pollinator richness and visitation rates among native and non-native plant species, although the study of β diversity indicated that only the native plant Lithodora fruticosa presented a differentiated set of pollinator species. Acacias experienced a large number of visits by numerous pollinator species, but massive acacia flowering resulted in flower visitation rates frequently lower than those of the native co-flowering species. We conclude that the establishment of mutualisms in Portugal likely contributes to the effective and profuse production of acacia seeds in Portugal. Despite the massive flowering of A. dealbata and A. longifolia, native plant species attained similar or higher visitation rates than acacias.

  6. Nitrogen uptake by Eucalyptus regnans and Acacia spp. - preferences, resource overlap and energetic costs.

    PubMed

    Pfautsch, Sebastian; Rennenberg, Heinz; Bell, Tina L; Adams, Mark A

    2009-03-01

    In southeastern Australia, the overstory species Eucalyptus regnans F. Muell. commonly grows with either of the two leguminous understory trees, Acacia melanoxylon (R. Br. Ex Ait. f.) or Acacia dealbata (Link.). Our objective was to elucidate interactions between the dominant eucalypt and its companion acacias for nitrogen (N) sources. Use of stable N isotopes as tracers revealed that ammonium was the preferred soil N source for all species, nevertheless, total N uptake varied greatly among species. Studies with double-labeled ((13)C/(15)N) glutamine indicated the uptake of this form of organic N in small amounts by both E. regnans and the Acacia spp. These and other data imply that, in contrast to boreal forests, organic N is not a significant component of N nutrition in mountain ash forests. Field and laboratory studies provided evidence that N(2)-fixation capacity of acacias varies with stand development, with N-fixing species playing an important role in N nutrition during the early but not the mature stages of forest growth. An index of N-uptake efficiency - the amount of oxygen consumed per unit N taken up - was compared across four N sources and three species. Nitrate uptake was the least efficient form of N acquisition, especially compared with ammonium uptake which was up to 30-fold less costly. Efficiency of glutamine uptake was intermediate between that of ammonium and nitrate. Differences in uptake efficiency among N forms were most pronounced for the Acacia spp. and least for E. regnans. We conclude that an overlap in requirements among sympatric Acacia spp. and E. regnans for specific soil N sources can be bypassed because of changes in biochemical strategies of Acacia spp. triggered by increasing soil N concentrations during stand development. Further studies might elucidate whether this is a common feature of complex forest ecosystems, or a specialty of the interaction between eucalypts and acacias.

  7. Analysis of commercial proanthocyanidins. Part 4: solid state (13)C NMR as a tool for in situ analysis of proanthocyanidin tannins, in heartwood and bark of quebracho and acacia, and related species.

    PubMed

    Reid, David G; Bonnet, Susan L; Kemp, Gabre; van der Westhuizen, Jan H

    2013-10-01

    (13)C NMR is an effective method of characterizing proanthocyanidin (PAC) tannins in quebracho (Schinopsis lorentzii) heartwood and black wattle (Acacia mearnsii) bark, before and after commercial extraction. The B-rings of the constituent flavan-3-ols, catechols (quebracho) or pyrogallols (wattle), are recognized in unprocessed source materials by "marker" signals at ca. 118 or 105ppm, respectively. NMR allows the minimum extraction efficiency to be calculated; ca. 30%, and ca. 80%, for quebracho heartwood and black wattle bark, respectively. NMR can also identify PAC tannin (predominantly robinetinidin), and compare tannin content, in bark from other acacia species; tannin content decreases in the order A. mearnsii, Acacia pycnantha (87% of A. mearnsii), Acacia dealbata and Acacia decurrens (each 74%) and Acacia karroo (30%). Heartwood from an underexploited PAC tannin source, Searsia lancea, taxonomically close to quebracho, shows abundant profisetinidin and catechin PACs. NMR offers the advantage of being applicable to source materials in their native state, and has potential applications in optimizing extraction processes, identification of tannin sources, and characterization of tannin content in cultivar yield improvement programmes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Antimicrobial activity and cytotoxic effects of Magnolia dealbata and its active compounds.

    PubMed

    Jacobo-Salcedo, Maria del Rosario; Gonzalez-Espindola, Luis Angel; Alonso-Castro, Angel Josabad; Gonzalez-Martinez, Marisela del Rocio; Domínguez, Fabiola; Garcia-Carranca, Alejandro

    2011-08-01

    Multi-drug resistance is of great concern for public health worldwide and necessitates the search for new antimicrobials from sources such as plants. Several Magnolia (Magnoliaceae) species have been reported to exert antimicrobial effects on sensitive and multidrug-resistant microorganisms. However, the antimicrobial properties of Magnolia dealbata have not been experimentally evaluated. The antimicrobial effects of an ethanol extract of Magnolia dealbata seeds (MDE) and its active compounds honokiol (HK) and magnolol (MG) were tested against the phytopathogen Clavibacter michiganensis subsp. michiganensis and several human multi-drug resistant pathogens using the disk-diffusion assay. The effects of MDE and its active compounds on the viability of human peripheral blood mononuclear cells (PBMC) were evaluated using MTT assay. MDE and its active compounds had antimicrobial activity (inhibition zone > 10 mm) against C. michiganensis, Pseudomonas aeruginosa, Acinetobacter baumannii, Acinetobacter lwoffii, Candida albicans, Candida tropicalis and Trichosporon belgeii. The results suggest that M. dealbata and its active compounds have selective antimicrobial effects against drug-resistant fungal and Gram (-) bacteria and exert minimal toxic effects on human PMBC.

  9. Response of Arnica dealbata to climate change, nitrogen deposition, and fire

    Treesearch

    Matthew Hurteau; Malcolm North

    2009-01-01

    Predicted changes in climate and increasing nitrogen deposition are likely to have significant impacts on species that have limited distributions or are already experiencing diminished population size. Arnica dealbata (A. Gray, Asteraceae), a listed sensitive species in Yosemite National Park, is endemic to California and has limited...

  10. Honokiol and magnolol production by in vitro micropropagated plants of Magnolia dealbata, an endangered endemic Mexican species.

    PubMed

    Domínguez, Fabiola; Chávez, Marco; Garduño-Ramírez, María Luisa; Chávez-Avila, Víctor M; Mata, Martín; Cruz-Sosa, Francisco

    2010-02-01

    An efficient protocol for the in vitro propagation of Magnolia dealbata Zucc., an important medicinal plant that is the source of the anxiolytic and anticancer compounds honokiol and magnolol, was established. This plant is wild-crafted, and conservationists have expressed concerns with regard to the sustainability of production. In the present work, two factors were found to be of importance for the regeneration of M. dealbata and the production of honokiol and magnolol. These factors were the type of explants and the combination and concentration of plant-growth regulators. Green, compact, nodular organogenic callus was obtained from leaf explants in a medium fortified with Murashige and Skoog salts and supplemented with 1.5 mg/L 2,4-dicholorophenoxyacetic acid and 1.5 mg/L kinetin. Shoots multiplication from callus cultures was achieved in the Murashige and Skoog (MS) medium with 1.5 mg/L thidiazuron (TDZ). Phenol secretion was controlled by the addition of 250 mg/L of activated charcoal. For rooting, shoots were transferred to MS medium supplemented with several auxins. After root induction, the plants were hardened in earthen pots containing sand, soil, and vermiculite. The contents of honokiol (HK) and magnolol (MG) were determined in different plant materials by high-performance liquid chromatography-diode-array detection techniques. This analysis revealed that the honokiol and magnolol content in aerial and underground parts of micropropagated M. dealbata were higher than that observed in wild plants (both 6 months old). Our results suggest that conservation of M. dealbata is possible by means of in vitro multiplication of leaf-derived callus. The usefulness of M. dealbata regeneration and production of HK and MG may be attributed to the proper selection of explant sourcing and identification of the correct growth medium to support adequate growth. This careful selection of explants and growth medium leads to a very useful source of plant material for

  11. Comparative study of Acacia nilotica exudate gum and acacia gum.

    PubMed

    Bhushette, Pravin R; Annapure, Uday S

    2017-09-01

    Over 900 species of Acacia trees are found on earth, most of them produce gums. Acacia nilotica (Babul tree) is one of the major gum-yielding acacia species found in he Indian subcontinent. A. nilotica gum was collected from Maharashtra, India and characterised for its proximate analysis, physicochemical, functional, rheological and thermal properties. These properties further were compared with commercially available Acacia gum (AG). The sugar composition of the gums indicated the presence of arabinose, galactose, and rhamnose in ANG and AG. FTIR spectrums revealed the typical trend of polysaccharides for both the gums, however, the difference was observed in fingerprint region. The rheological outcomes were derived from flow curve measurements of gums at different concentrations and temperatures. Investigations of the flow curves of both gums revealed the diminutive difference in viscosity profile. The concentration difference in the monosaccharides of polysaccharides and proximate analysis of gums could be the responsible for the difference in rheological and thermal properties of gums. However, ANG shows good resemblance with AG and can be substituted for numerous applications in food and pharmaceutical industry. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. 21 CFR 184.1330 - Acacia (gum arabic).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acacia (gum arabic). 184.1330 Section 184.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Listing of Specific Substances Affirmed as GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic) is...

  13. 21 CFR 184.1330 - Acacia (gum arabic).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acacia (gum arabic). 184.1330 Section 184.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Listing of Specific Substances Affirmed as GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic) is...

  14. 21 CFR 172.780 - Acacia (gum arabic).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acacia (gum arabic). 172.780 Section 172.780 Food... Other Specific Usage Additives § 172.780 Acacia (gum arabic). The food additive may be safely used in food in accordance with the following prescribed conditions: (a) Acacia (gum arabic) is the dried gummy...

  15. 21 CFR 172.780 - Acacia (gum arabic).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acacia (gum arabic). 172.780 Section 172.780 Food... Other Specific Usage Additives § 172.780 Acacia (gum arabic). The food additive may be safely used in food in accordance with the following prescribed conditions: (a) Acacia (gum arabic) is the dried gummy...

  16. 21 CFR 184.1330 - Acacia (gum arabic).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acacia (gum arabic). 184.1330 Section 184.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT... GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic) is the dried gummy exudate from stems and...

  17. 21 CFR 172.780 - Acacia (gum arabic).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acacia (gum arabic). 172.780 Section 172.780 Food....780 Acacia (gum arabic). The food additive may be safely used in food in accordance with the following prescribed conditions: (a) Acacia (gum arabic) is the dried gummy exudate from stems and branches of trees of...

  18. Symbiotic diversity in the cosmopolitan genus Acacia

    Treesearch

    James K. Leary; Paul W. Singleton; Paul G. Scowcroft; Dulal Borthakur

    2006-01-01

    Acacia is the second largest genus within the Leguminosae, with 1352 species identified. This genus is now known to be polyphyletic and the international scientific community will presumably split Acacia into five new genera. This review examines the diversity of biological nitrogen fixation symbiosis within Acacia as a single genus. Due to its global importance, an...

  19. Comparison of the in vitro anthelmintic effects of Acacia nilotica and Acacia raddiana

    PubMed Central

    Zabré, Geneviève; Kaboré, Adama; Bayala, Balé; Katiki, Luciana M.; Costa-Júnior, Lívio Martins; Tamboura, Hamidou H.; Belem, Adrien M.G.; Abdalla, Adibe L.; Niderkorn, Vincent; Hoste, Hervé; Louvandini, Helder

    2017-01-01

    Gastrointestinal nematodes are a major threat to small ruminant rearing in the Sahel area, where farmers traditionally use bioactive plants to control these worms, including Acacia nilotica and Acacia raddiana. The main aim of this study was to screen the potential anthelmintic properties of aqueous and acetone extracts of leaves of these two plants based on three in vitro assays: (1) the egg hatch inhibition assay (EHA); (2) the larvae exsheathment inhibition assay (LEIA) using Haemonchus contortus as a model; and (3) an adult mortality test (AMT) applied on Caenorhabditis elegans. For the EHA, only A. raddiana was effective with IC50 = 1.58 mg/mL for aqueous extract, and IC50 = 0.58 mg/mL for acetonic extract. For the LEIA, all extracts inhibited the exsheathment of larvae compared to the controls, and the aqueous extract of A. nilotica was more larvicidal with IC50 = 0.195 mg/mL. In general, all responses to the substances were dose-dependent and were significantly different from the control group (p < 0.05). For the AMT, the extracts of the two Acacia species were effective but A. raddiana showed greater efficacy with 100% mortality at 2.5 mg/mL and LC50 = 0.84 mg/mL (acetonic extract). The addition of polyvinyl polypyrrolidone (PVPP) to the extracts suggested that tannins were responsible for blocking egg eclosion and inducing adult mortality but were not responsible for exsheathment inhibition. These results suggest that the leaves of these Acacia species possess ovicidal and larvicidal activities in vitro against H. contortus, and adulticidal effects against C. elegans. PMID:29173278

  20. Characterisation and molecular association of Nigerian and Sudanese Acacia gum exudates

    USDA-ARS?s Scientific Manuscript database

    The chemical and physicochemical characteristics of gum exudate samples harvested from mature trees of Acacia senegal at two specific locations in Nigeria have been investigated together with gum samples harvested from Acacia senegal and Acacia seyal originating from Sudan. The monosaccharide sugar ...

  1. Investigation into nanocellulosics versus acacia reinforced acrylic films

    Treesearch

    Yunqiao Pu; Jianguo Zhang; Thomas Elder; Yulin Deng; Paul Gatenholm; Arthur J. Ragauskas

    2007-01-01

    Three closely related cellulosic acrylic latex films were prepared employing acacia pulp fibers, cellulose whiskers and nonocellulose balls and their respective strength properties were determined. Cellulose whisker reinforced composites had enhanced strength properties compared to the acacia pulp and nanoball composites. AFM analysis indicated that the cellulose...

  2. 75 FR 27334 - Acacia Natural Gas Corporation; Notice of Baseline Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-14

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR10-16-001] Acacia Natural Gas Corporation; Notice of Baseline Filing May 7, 2010. Take notice that on May 5, 2010, Acacia Natural Gas Corporation (Acacia) submitted a correction to its April 27, 2010, baseline filing of its...

  3. [Active carbon from Thalia dealbata residues: its preparation and adsorption performance to crystal violet].

    PubMed

    Chu, Shu-Yi; Yang, Min; Xiao, Ji-Bo; Zhang, Jun; Zhu, Yan-Ping; Yan, Xiang-Jun; Tian, Guang-Ming

    2013-06-01

    By using phosphoric acid as activation agent, active carbon was prepared from Thalia dealbata residues. The BET specific surface area of the active carbon was 1174.13 m2 x g(-1), micropore area was 426.99 m2 x g(-1), and average pore diameter was 3.23 nm. An investigation was made on the adsorption performances of the active carbon for crystal violet from aqueous solution under various conditions of pH, initial concentration of crystal violet, contact time, and contact temperature. It was shown that the adsorbed amount of crystal violet was less affected by solution pH, and the adsorption process could be divided into two stages, i. e., fast adsorption and slow adsorption, which followed the pseudo-second-order kinetics model. At the temperature 293, 303, and 313 K, the adsorption process was more accordance with Langmuir isotherm model, and the maximum adsorption capacity was 409.83, 425.53, and 438.59 mg x g(-1), respectively. In addition, the adsorption process was spontaneous and endothermic, and the randomness of crystal violet molecules increased.

  4. Host Plant Use by Competing Acacia-Ants: Mutualists Monopolize While Parasites Share Hosts

    PubMed Central

    Kautz, Stefanie; Ballhorn, Daniel J.; Kroiss, Johannes; Pauls, Steffen U.; Moreau, Corrie S.; Eilmus, Sascha; Strohm, Erhard; Heil, Martin

    2012-01-01

    Protective ant-plant mutualisms that are exploited by non-defending parasitic ants represent prominent model systems for ecology and evolutionary biology. The mutualist Pseudomyrmex ferrugineus is an obligate plant-ant and fully depends on acacias for nesting space and food. The parasite Pseudomyrmex gracilis facultatively nests on acacias and uses host-derived food rewards but also external food sources. Integrative analyses of genetic microsatellite data, cuticular hydrocarbons and behavioral assays showed that an individual acacia might be inhabited by the workers of several P. gracilis queens, whereas one P. ferrugineus colony monopolizes one or more host trees. Despite these differences in social organization, neither of the species exhibited aggressive behavior among conspecific workers sharing a tree regardless of their relatedness. This lack of aggression corresponds to the high similarity of cuticular hydrocarbon profiles among ants living on the same tree. Host sharing by unrelated colonies, or the presence of several queens in a single colony are discussed as strategies by which parasite colonies could achieve the observed social organization. We argue that in ecological terms, the non-aggressive behavior of non-sibling P. gracilis workers — regardless of the route to achieve this social structure — enables this species to efficiently occupy and exploit a host plant. By contrast, single large and long-lived colonies of the mutualist P. ferrugineus monopolize individual host plants and defend them aggressively against invaders from other trees. Our findings highlight the necessity for using several methods in combination to fully understand how differing life history strategies affect social organization in ants. PMID:22662191

  5. 77 FR 63311 - Acacia Natural Gas Corporation; Notice of Petition for Rate Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR13-1-000] Acacia Natural Gas Corporation; Notice of Petition for Rate Approval Take notice that on October 9, 2012, Acacia Natural Gas Corporation (Acacia) filed a Petition for Rate Approval pursuant to 284.123(b)(2) of the...

  6. Influence of halophytic hosts on their parasites—the case of Plicosepalus acaciae

    PubMed Central

    Veste, Maik; Todt, Henning; Breckle, Siegmar-W.

    2015-01-01

    Halophytes develop various morphological and physiological traits that enable them to grow successfully on saline substrates. Parasitic plants on halophytic hosts may also encounter salt stress. We investigated the mistletoe Plicosepalus acaciae (syn: Loranthus acacia; Loranthaceae), which occurs on 5 halophytic and at least 10 non-halophytic hosts in the Southern Arava Valley (Israel). Plicosepalus acaciae is a common parasite north of Eilat to the Dead Sea area and in the Jordan Valley. Morphological and physiological responses of P. acaciae to salinity were investigated by comparison of plants on halophytic with those on non-halophytic hosts. Ion patterns of different host–parasite associations were determined as was the development of leaf succulence at different growth stages. The leaf water content of P. acaciae increased and leaves developed succulence when growing on halophytic hosts, especially on Tamarix species, where leaf water content was three times higher than that on non-halophytic hosts and the leaf volume increased four to five times. The reason for increased succulence was a higher ion concentration of, and osmotic adjustment with, Na+ and Cl−. Plicosepalus acaciae showed a high morphological and ecophysiological plasticity, enabling it to cope with salt stress, and can be classified as a facultative eu-halophyte, which increases its halo-succulence according to the host. Host–parasite associations are a model system for the investigation of halophytes under different salt stress conditions. PMID:25515726

  7. 75 FR 28599 - Acacia Natural Gas Corporation; Notice of Baseline Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... Natural Gas Corporation (Acacia) submitted a corrected baseline filing of its Statement of Operating Conditions for the interruptible transportation services provided under section 311(a)(2) of the Natural Gas... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR10-16-002] Acacia Natural...

  8. 75 FR 24940 - Acacia Natural Gas Corporation; Notice of Baseline Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-06

    ... Natural Gas Corporation (Acacia) submitted its baseline filing of its Statement of Operating Conditions for the interruptible transportation services provided under section 311(a)(2) of the Natural Gas... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR10-16-000] Acacia Natural...

  9. The evolutionary history and biogeography of Mimosoideae (Leguminosae): an emphasis on African acacias.

    PubMed

    Bouchenak-Khelladi, Yanis; Maurin, Olivier; Hurter, Johan; van der Bank, Michelle

    2010-11-01

    The systematics of Mimosoideae has been in a state of flux, which reflects overall poor knowledge of the evolution and biogeography of this group. Preliminary molecular phylogenetic analyses suggest the tribal system of Mimosoideae needs a complete revision. This has led to the use of new generic names for Acacia sensu lato (s.l. hereafter) following the re-typification of Acacia with an Australian type: (i) Acacia sensu stricto (s.s. hereafter), Vachellia, Senegalia, Acaciella and Mariosousa. This study reconstructs the evolutionary history of Mimosoideae, using the most comprehensive sampling to date, with an emphasis on African species. It aims to reconstruct the phylogenetic relationships among the five recognized genera within Acacieae as the precursor to elucidate the paleo-biogeography of mimosoids and their adaptation to open habitats in the Cenozoic. The basal position of Mimoseae lineages with regards to Vachellia and Senegalia+Mariosousa+Acaciella+Ingeae+Acacia s.s. clades is a novel finding. Vachellia (formerly Acacia subgenus Acacia) is found monophyletic. A grade including the remaining Mimoseae lineages is found sister to the Senegalia+Mariosousa+Acaciella+Ingeae+Acacia s.s. clade. The major clades originated in the late Oligocene-early Miocene (∼25mya). The transitions from close to open habitats occurred during the Miocene for at least four mimosoid lineages. These are interpreted as responses to increased seasonality leading to fire climates and drying trends in the Miocene, which allowed the expansion of open habitats, such as savannas, worldwide. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. Mechanical properties of acacia and eucalyptus wood chars

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

    Kumar, M.; Verma, B.B.; Gupta, R.C.

    1999-10-01

    In the present investigation the effects of carbonization conditions (temperature and heating rate) on the mechanical properties (such as crushing and impact strengths and shatter index) of acacia and eucalyptus wood chars have been determined. The crushing and impact strengths of both the acacia and eucalyptus wood chars (made by slow carbonization) decreased with increase of preparation temperature up to 600 C, followed by an increase thereafter. These wood chars showed a continuous increase in shatter index values with carbonization temperature. In contrast to slow carbonization (heating rate 4 C min{sup {minus}1}), rapid carbonization (heating rate 30 C min{sup {minus}1})more » yielded chars of lower crushing strengths. Slowly carbonized eucalyptus wood gave chars of superior crushing and impact strengths than those produced from acacia wood under the same carbonization conditions. The crushing and impact strengths of these wood chars, in general, have shown an increase with increase in their apparent density. The crushing strength of cubic-shaped wood char decreased with increase in size.« less

  11. The Importance of Acacia Trees for Insectivorous Bats and Arthropods in the Arava Desert

    PubMed Central

    Hackett, Talya D.; Korine, Carmi; Holderied, Marc W.

    2013-01-01

    Anthropogenic habitat modification often has a profound negative impact on the flora and fauna of an ecosystem. In parts of the Middle East, ephemeral rivers (wadis) are characterised by stands of acacia trees. Green, flourishing assemblages of these trees are in decline in several countries, most likely due to human-induced water stress and habitat changes. We examined the importance of healthy acacia stands for bats and their arthropod prey in comparison to other natural and artificial habitats available in the Arava desert of Israel. We assessed bat activity and species richness through acoustic monitoring for entire nights and concurrently collected arthropods using light and pit traps. Dense green stands of acacia trees were the most important natural desert habitat for insectivorous bats. Irrigated gardens and parks in villages and fields of date palms had high arthropod levels but only village sites rivalled acacia trees in bat activity level. We confirmed up to 13 bat species around a single patch of acacia trees; one of the richest sites in any natural desert habitat in Israel. Some bat species utilised artificial sites; others were found almost exclusively in natural habitats. Two rare species (Barbastella leucomelas and Nycteris thebaica) were identified solely around acacia trees. We provide strong evidence that acacia trees are of unique importance to the community of insectivorous desert-dwelling bats, and that the health of the trees is crucial to their value as a foraging resource. Consequently, conservation efforts for acacia habitats, and in particular for the green more densely packed stands of trees, need to increase to protect this vital habitat for an entire community of protected bats. PMID:23441145

  12. Preparation and physicochemical properties of protein concentrate and isolate produced from Acacia tortilis (Forssk.) Hayne ssp. raddiana.

    PubMed

    Embaby, Hassan E; Swailam, Hesham M; Rayan, Ahmed M

    2018-02-01

    The composition and physicochemical properties of defatted acacia flour (DFAF), acacia protein concentrate (APC) and acacia protein isolate (API) were evaluated. The results indicated that API had lower, ash and fat content, than DFAF and APC. Also, significant difference in protein content was noticed among DFAF, APC and API (37.5, 63.7 and 91.8%, respectively). Acacia protein concentrate and isolates were good sources of essential amino acids except cystine and methionine. The physicochemical and functional properties of acacia protein improved with the processing of acacia into protein concentrate and protein isolate. The results of scanning electron micrographs showed that DFAF had a compact structure; protein concentrate were, flaky, and porous type, and protein isolate had intact flakes morphology.

  13. Co-composting of invasive Acacia longifolia with pine bark for horticultural use.

    PubMed

    Brito, Luis Miguel; Mourão, Isabel; Coutinho, João; Smith, Stephen R

    2015-01-01

    The feasibility of commercial-scale co-composting of waste biomass from the control of invasive Acacia species with pine bark waste from the lumber industry, in a blend ratio of 60:40 (v:v), was investigated and compared with previous research on the composting of Acacia without additional feedstock, to determine the potential process and end-product quality benefits of co-composting with bark. Pile temperatures rose rapidly to >70 °C and were maintained at >60 °C for several months. Acacia and bark biomass contained a large fraction of mineralizable organic matter (OM) equivalent to approximately 600 g kg(-1) of initial OM. Bark was more recalcitrant to biodegradation compared with Acacia, which degraded at twice the rate of bark. Therefore, incorporating the bark increased the final amount of compost produced compared with composting Acacia residues without bark. The relatively high C/N ratio of the composting matrix (C/N=56) and NH3 volatilization explained the limited increases in NH4+-N content, whereas concentrations of conservative nutrient elements (e.g. P, K, Ca, Mg, Fe) increased in proportion to OM mineralization, enriching the compost as a nutrient source for horticultural use. Nitrogen concentrations also increased to a small extent, but were much more dynamic and losses, probably associated with N volatilization mechanisms, were difficult to actively control. The physicochemical characteristics of the stabilized end-product, such as pH, electrical conductivity and OM content, were improved with the addition of bark to Acacia biomass, and the final compost characteristics were suitable for use for soil improvement and also as horticultural substrate components.

  14. Biological activities of some Acacia spp. (Fabaceae) against new clinical isolates identified by ribosomal RNA gene-based phylogenetic analysis.

    PubMed

    Mahmoud, Mahmoud Fawzy; Alrumman, Sulaiman Abdullah; Hesham, Abd El-Latif

    2016-01-01

    Nowadays,most of the pathogenic bacteria become resistant to antibiotics. Therefore,the pharmaceutical properties of the natural plant extracts have become of interest to researchers as alternative antimicrobial agents. In this study,antibacterial activities of extract gained from Acacia etbaica, Acacia laeta, Acacia origena and Acacia pycnantha have been evaluated against isolated pathogenic bacteria (Strains MFM-01, MFM-10 and AH-09) using agar well diffusion methods.The bacterial strains were isolated from infected individuals,and their exact identification was detected on the basis of 16S rRNA gene amplification and sequence determination. Alignment results and the comparison of 16 SrRN A gene sequences of the isolates to 16 SrRN A gene sequences available in Gen Bank data base as well as the phylogenetic analysis confirmed the accurate position of the isolates as Klebsiella oxytoca strain MFM-01, Staphylococcus aureus strain MFM-10 and Klebsiella pneumoniae strain AH-09. Except for cold water, all tested solvents (Chloroform, petroleum ether, methanol, diethyl ether, and acetone) showed variation in their activity against studied bacteria. GC-MS analysis of ethanol extracts showed that four investigated Acacia species have different phyto components. Eight important pharmaceutical components were found in the legume of Acacia etbaica, seven in the legume of Acacia laeta, fifteen in the legume of Acacia origena and nine in the leaves of Acacia pycnantha. A dendrogram was constructed based on chemical composition, revealed that Acacia laeta is more closely related to Acacia etbaica forming on eclade, whereas Acacia origena less similar to other species. Our results demonstrated that, investigated plants and chemical compounds present could be used as promising antibacterial agents.

  15. Establishment Success of Coexisting Native and Exotic Trees Under an Experimental Gradient of Irradiance and Soil Moisture

    NASA Astrophysics Data System (ADS)

    González-Muñoz, Noelia; Castro-Díez, Pilar; Fierro-Brunnenmeister, Natalia

    2011-10-01

    The exotic trees Ailanthus altissima, Robinia pseudoacacia, Acer negundo and Elaeagnus angustifolia coexist with the native trees Fraxinus angustifolia and Ulmus minor in river banks of central Spain. Similarly, the exotic trees Acacia dealbata and Eucalyptus globulus co-occur with the natives Quercus pyrenaica and Pinus pinaster in Northwest Spain. We aimed to identify the environmental conditions that favour or hamper the establishment success of these species. In spring 2008, seeds of the studied species were sown under an experimental gradient of light (100, 65, 35, 7% of full sunlight) combined with three levels of soil moisture (mean soil water potential = -0.97, -1.52 and -1.77 MPa.). During the first growing season we monitored seed emergence and seedling survival. We found that the effect of light on the establishment success was stronger than the effect of soil moisture. Both exotic and native species of central Spain showed a good performance under high light, A. negundo being the most shade tolerant . Water shortage diminished E. angustifolia and A. altissima success. Among NW Spain species, A. dealbata and P. pinaster were found to be potential competitors for colonizing high-irradiance scenarios, while Q. pyrenaica and E. globulus were more successful under moderate shade. High soil moisture favoured E. globulus but not A. dealbata establishment. These results contribute to understand some of the factors controlling for spatial segregation between coexisting native and exotic tree species, and can help to take decisions orientated to the control and management of these exotic species.

  16. Establishment success of coexisting native and exotic trees under an experimental gradient of irradiance and soil moisture.

    PubMed

    González-Muñoz, Noelia; Castro-Díez, Pilar; Fierro-Brunnenmeister, Natalia

    2011-10-01

    The exotic trees Ailanthus altissima, Robinia pseudoacacia, Acer negundo and Elaeagnus angustifolia coexist with the native trees Fraxinus angustifolia and Ulmus minor in river banks of central Spain. Similarly, the exotic trees Acacia dealbata and Eucalyptus globulus co-occur with the natives Quercus pyrenaica and Pinus pinaster in Northwest Spain. We aimed to identify the environmental conditions that favour or hamper the establishment success of these species. In spring 2008, seeds of the studied species were sown under an experimental gradient of light (100, 65, 35, 7% of full sunlight) combined with three levels of soil moisture (mean soil water potential = -0.97, -1.52 and -1.77 MPa.). During the first growing season we monitored seed emergence and seedling survival. We found that the effect of light on the establishment success was stronger than the effect of soil moisture. Both exotic and native species of central Spain showed a good performance under high light, A. negundo being the most shade tolerant. Water shortage diminished E. angustifolia and A. altissima success. Among NW Spain species, A. dealbata and P. pinaster were found to be potential competitors for colonizing high-irradiance scenarios, while Q. pyrenaica and E. globulus were more successful under moderate shade. High soil moisture favoured E. globulus but not A. dealbata establishment. These results contribute to understand some of the factors controlling for spatial segregation between coexisting native and exotic tree species, and can help to take decisions orientated to the control and management of these exotic species.

  17. Trial production of fuel pellet from Acacia mangium bark waste biomass

    NASA Astrophysics Data System (ADS)

    Amirta, R.; Anwar, T.; Sudrajat; Yuliansyah; Suwinarti, W.

    2018-04-01

    Fuel pellet is one of the innovation products that can be produced from various sources of biomass such as agricultural residues, forestry and also wood industries including wood bark. Herein this paper, the potential fuel pellet production using Acacia mangium bark that abundant wasted from chip mill industry was studied. Fuel pellet was produced using a modified animal feed pellet press machine equipped with rotating roller-cylinders. The international standards quality of fuel pellet such as ONORM (Austria), SS (Sweden), DIN (Germany), EN (European) and ITEBE (Italy) were used to evaluate the optimum composition of feedstock and additive used. Theresults showed the quality offuel pellet produced were good compared to commercial sawdust pellet. Mixed of Acacia bark (dust) with 10% of tapioca and 20% of glycerol (w/w) was increased the stable form of pellet and the highest heating value to reached 4,383 Kcal/kg (calorific value). Blending of Acacia bark with tapioca and glycerol was positively improved its physical, chemical and combustion properties to met the international standards requirement for export market. Based on this finding, production of fuel pellet from Acacia bark waste biomass was promising to be developed as an alternative substitution of fossil energy in the future.

  18. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... denture adhesive. 872.3400 Section 872.3400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... and sodium borate with or without acacia denture adhesive. (a) Identification. A karaya and sodium borate with or without acacia denture adhesive is a device composed of karaya and sodium borate with or...

  19. Electrospray-assisted drying of live probiotics in acacia gum microparticles matrix.

    PubMed

    Zaeim, Davood; Sarabi-Jamab, Mahboobe; Ghorani, Behrouz; Kadkhodaee, Rassoul; Tromp, R Hans

    2018-03-01

    Acacia gum solution was employed as a carrier for electrospray-assisted drying of probiotic cells. To optimize the process, effect of gum concentration, thermal sterilization as a prerequisite for microbial studies, and surfactant addition on physical properties of feed solution was investigated. Increasing gum concentration from 20 to 40 wt.% led to a viscosity increase, whilst surface tension did not change meaningfully and electrical conductivity declined after an increasing trend up to 30 wt.% of the gum. Thermal sterilization increased the viscosity without any significant effect on the conductivity and surface tension. Surfactant addition reduced the surface tension and conductivity but the viscosity increased. Highly uniform particles were formed by electrospray-assisted drying of autoclaved 35 wt.% acacia gum solution containing 1 wt.% Tween 80. Thermal sterilization and surfactant addition improved electrospray-ability of acacia gum solution. Bacterial count showed that more than 96 percent of probiotic cells passed the process viably. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. A comparison of the stability of beverage cloud emulsions formulated with different gum acacia- and starch-based emulsifiers.

    PubMed

    Reiner, S J; Reineccius, G A; Peppard, T L

    2010-06-01

    The performance of several hydrocolloids (3 gum acacias, 1 modified gum acacia, and 3 modified starches) in stabilizing beverage emulsions and corresponding model beverages was investigated employing different core materials, emulsifier usage levels, and storage temperatures. Concentrated emulsions were prepared using orange terpenes or Miglyol 812 (comprising medium-chain triglycerides, MCT) weighted 1:1 with ester gum, stored at 25 or 35 degrees C, and analyzed on days 0, 1, and 3. On day 3, model beverages were made from each emulsion, stored at both temperatures, and analyzed weekly for 4 wk. Stability of concentrated emulsions was assessed by measuring mean particle size and by visual observations of ringing; beverage stability was judged similarly and also by loss of turbidity. Particle size measurements showed concentrated emulsions containing gum acacia or modified gum acacia with either core material were stable over 3 d storage at both temperatures whereas those made with modified starches were not, destabilization being faster at 35 degrees C. Beverages based on orange terpenes, in contrast to Miglyol, yielded smaller mean particle sizes, both on manufacture and during storage, regardless of hydrocolloid used. Visual observations of ringing generally supported this finding. Modified gum acacia was evaluated at both recommended and higher usage levels, stability increasing in the latter case. In general, all gum acacia and modified gum acacia emulsifiers were superior in stability to those based on modified starches, at either temperature, for orange terpene-based beverages. In Miglyol-based beverages, similar results were seen, except 1 modified starch performed as well as the gum acacia products.

  1. Relationships between stem diameter, sapwood area, leaf area and transpiration in a young mountain ash forest.

    PubMed

    Vertessy, R A; Benyon, R G; O'Sullivan, S K; Gribben, P R

    1995-09-01

    We examined relationships between stem diameter, sapwood area, leaf area and transpiration in a 15-year-old mountain ash (Eucalyptus regnans F. Muell.) forest containing silver wattle (Acacia dealbata Link.) as a suppressed overstory species and mountain hickory (Acacia frigescens J.H. Willis) as an understory species. Stem diameter explained 93% of the variation in leaf area, 96% of the variation in sapwood area and 88% of the variation in mean daily spring transpiration in 19 mountain ash trees. In seven silver wattle trees, stem diameter explained 87% of the variation in sapwood area but was a poor predictor of the other variables. When transpiration measurements from individual trees were scaled up to a plot basis, using stem diameter values for 164 mountain ash trees and 124 silver wattle trees, mean daily spring transpiration rates of the two species were 2.3 and 0.6 mm day(-1), respectively. The leaf area index of the plot was estimated directly by destructive sampling, and indirectly with an LAI-2000 plant canopy analyzer and by hemispherical canopy photography. All three methods gave similar results.

  2. Delayed colonisation of Acacia by thrips and the timing of host-conservatism and behavioural specialisation.

    PubMed

    McLeish, Michael J; Miller, Joseph T; Mound, Laurence A

    2013-09-09

    Repeated colonisation of novel host-plants is believed to be an essential component of the evolutionary success of phytophagous insects. The relative timing between the origin of an insect lineage and the plant clade they eat or reproduce on is important for understanding how host-range expansion can lead to resource specialisation and speciation. Path and stepping-stone sampling are used in a Bayesian approach to test divergence timing between the origin of Acacia and colonisation by thrips. The evolution of host-plant conservatism and ecological specialisation is discussed. Results indicated very strong support for a model describing the origin of the common ancestor of Acacia thrips subsequent to that of Acacia. A current estimate puts the origin of Acacia at approximately 6 million years before the common ancestor of Acacia thrips, and 15 million years before the origin of a gall-inducing clade. The evolution of host conservatism and resource specialisation resulted in a phylogenetically under-dispersed pattern of host-use by several thrips lineages. Thrips colonised a diversity of Acacia species over a protracted period as Australia experienced aridification. Host conservatism evolved on phenotypically and environmentally suitable host lineages. Ecological specialisation resulted from habitat selection and selection on thrips behavior that promoted primary and secondary host associations. These findings suggest that delayed and repeated colonisation is characterised by cycles of oligo- or poly-phagy. This results in a cumulation of lineages that each evolve host conservatism on different and potentially transient host-related traits, and facilitates both ecological and resource specialisation.

  3. Reproduction of Acacia koa after Fire

    Treesearch

    Paul G. Scowcroft; Hulton B. Wood

    1976-01-01

    The abundance, distribution, growth, and mortality of koa (Acacia koa Gray) seedlings after fires were monitored periodically on two burned areas on Oahu for 2.5 years. On one area, seedling density peaked at 95,300/ha 6 months after the fire; 21 months later it had declined to 18,500/ha. On the other area, peak seedling density occurred at 2 -...

  4. Koa (Acacia koa) ecology and silviculture

    Treesearch

    Patrick J. Baker; Paul G. Scowcroft; John J. Ewel

    2009-01-01

    Koa (Acacia koa) is a tree species endemic to Hawaii that is of immense ecological and economic importance. This species has been mined from local forests for its wood for more than 100 years, and extensive areas of koa-dominated forests have been converted to grazing lands. Today, in recognition of the great importance and value of koa and the...

  5. 21 CFR 172.780 - Acacia (gum arabic).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acacia (gum arabic). 172.780 Section 172.780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION...

  6. 21 CFR 172.780 - Acacia (gum arabic).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acacia (gum arabic). 172.780 Section 172.780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION...

  7. Condensed tannins from acacia mangium bark: Characterization by spot tests and FTIR

    NASA Astrophysics Data System (ADS)

    Bharudin, Muhammad Azizi; Zakaria, Sarani; Chia, Chin Hua

    2013-11-01

    This paper describes the adaptation and evaluation of one chemical tests for tannins characterization in acacia mangium bark. Acid butanol test developed to identify respectively condensed tannins is described. The two traditional tests used for tannin characterization namely ferric test and vanillin test were also performed and their functional also discussed. Condensed tannins were extracted from acacia mangium bark using water medium in presence of three different concentration basic reagent of NaOH(5%,10% and 15%) and were characterized by FT-IR spectrometry.

  8. Acacia shrubs respond positively to high severity wildfire: Implications for conservation and fuel hazard management.

    PubMed

    Gordon, Christopher E; Price, Owen F; Tasker, Elizabeth M; Denham, Andrew J

    2017-01-01

    High severity wildfires pose threats to human assets, but are also perceived to impact vegetation communities because a small number of species may become dominant immediately after fire. However there are considerable gaps in our knowledge about species-specific responses of plants to different fire severities, and how this influences fuel hazard in the short and long-term. Here we conduct a floristic survey at sites before and two years after a wildfire of unprecedented size and severity in the Warrumbungle National Park (Australia) to explore relationships between post-fire growth of a fire responsive shrub genera (Acacia), total mid-story vegetation cover, fire severity and fuel hazard. We then survey 129 plots surrounding the park to assess relationships between mid-story vegetation cover and time-since-fire. Acacia species richness and cover were 2.3 and 4.3 times greater at plots after than before the fire. However the same common dominant species were present throughout the study. Mid-story vegetation cover was 1.5 times greater after than before the wildfire, and Acacia species contribution to mid-story cover increased from 10 to 40%. Acacia species richness was not affected by fire severity, however strong positive associations were observed between Acacia and total mid-story vegetation cover and severity. Our analysis of mid-story vegetation recovery showed that cover was similarly high between 2 and 30years post-fire, then decreased until 52years. Collectively, our results suggest that Acacia species are extremely resilient to high severity wildfire and drive short to mid-term increases in fuel hazard. Our results are discussed in relation to fire regime management from the twin perspectives of conserving biodiversity and mitigating human losses due to wildfire. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. A photographic guide to Acacia koa defects

    Treesearch

    Eini C. Lowell; Janice K. Wiedenbeck; Betsy S. Porterfield

    2013-01-01

    Acacia koa (A. Gray), native to the Hawaiian Islands, has both cultural and economic significance. Koa wood is world-renowned for its extensive use in furniture, tone wood for musical instruments, and other items of cultural importance. Old-growth koa is decreasing in supply, yet dead and dying koa is still being harvested for manufacture of...

  10. Non-protein amino acids in Australian acacia seed: implications for food security and recommended processing methods to reduce djenkolic acid.

    PubMed

    Boughton, Berin A; Reddy, Priyanka; Boland, Martin P; Roessner, Ute; Yates, Peter

    2015-07-15

    Seed of Australian acacia species, Acacia colei, Acacia elecantha, Acacia torulosa, Acacia turmida and Acacia saligna, were analysed for the presence of toxic non-protein amino acids and the levels of essential amino acids. Amines were derivatised with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate before analysis using liquid chromatography electrospray ionisation triple quadrupole mass spectrometry (LC-ESI-QQQ-MS). Multiple reaction monitoring (MRM) with optimised transitions and collision energies for each analyte were employed. The known nephrotoxic compound djenkolic acid was found to be present at elevated levels in all species tested. The lowest levels were in A. colei (0.49% w/w) and the highest in A. saligna (1.85% w/w). Observed levels of djenkolic acid are comparable to measured and reported levels found in the djenkol bean. Subsequent testing of seed processing methods showed djenkolic acid levels can be significantly reduced by over 90% by dry roasting at 180 °C rendering the seed safe for human consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Isolation of Abscisic Acid from Korean Acacia Honey with Anti-Helicobacter pylori Activity

    PubMed Central

    Kim, SeGun; Hong, InPyo; Woo, SoonOk; Jang, HyeRi; Pak, SokCheon; Han, SangMi

    2017-01-01

    Background: Helicobacter pylori (H. pylori) is linked to the development of the majority of peptic ulcers and some types of gastric cancers, and its antibiotic resistance is currently found worldwide. Objective: This study is aimed at evaluating the anti-H. pylori activity of Korean acacia honey and isolating the related active components using organic solvents. Material and Methods: The crude acacia honey was extracted with n-hexane, dichloromethane, ethyl acetate (EtOAc), and n-butanol. The EtOAc extract was subjected to octadecyl-silica chromatography. The extracts and fractions were then examined for anti-H. pylori activity using the agar well diffusion method. The antimicrobial activity of abscisic acid against H. pylori was investigated by determining the minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), and by performing a time-kill assay. Results: Abscisic acid related to the botanical origins of acacia honey from Korea has been analyzed using ultra-performance liquid chromatography. The MICs and MBCs of abscisic acid were 2.7 ± 1.3 and 6.9 ± 1.9 μg/mL, respectively. The bactericidal activity of abscisic acid (at 10.8 μg/mL corresponding to 4 × MIC) killed the organism within 36–72 h. These results suggest that abscisic acid isolated from Korean acacia honey has antibacterial activity against H. pylori. Conclusion: Abscisic acid isolated from Korean acacia honey can be therapeutic and may be further exploited as a potential lead candidate for the development of treatments for H. pylori-induced infections. SUMMARY The crude acacia honey was extracted with n-hexane, dichloromethane, EtOAc, and n-butanolThe EtOAc extract yielded eight fractions and four subfractions were subsequently obtained chromatographicallyAbscisic acid was isolated from one subfractionAll the solvent extracts and fractions showed antibacterial activity against H. pyloriAbscisic acid exhibited antibacterial activity against H. pylori

  12. Isolation of Abscisic Acid from Korean Acacia Honey with Anti-Helicobacter pylori Activity.

    PubMed

    Kim, SeGun; Hong, InPyo; Woo, SoonOk; Jang, HyeRi; Pak, SokCheon; Han, SangMi

    2017-07-01

    Helicobacter pylori ( H. pylori ) is linked to the development of the majority of peptic ulcers and some types of gastric cancers, and its antibiotic resistance is currently found worldwide. This study is aimed at evaluating the anti- H. pylori activity of Korean acacia honey and isolating the related active components using organic solvents. The crude acacia honey was extracted with n -hexane, dichloromethane, ethyl acetate (EtOAc), and n -butanol. The EtOAc extract was subjected to octadecyl-silica chromatography. The extracts and fractions were then examined for anti- H. pylori activity using the agar well diffusion method. The antimicrobial activity of abscisic acid against H. pylori was investigated by determining the minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), and by performing a time-kill assay. Abscisic acid related to the botanical origins of acacia honey from Korea has been analyzed using ultra-performance liquid chromatography. The MICs and MBCs of abscisic acid were 2.7 ± 1.3 and 6.9 ± 1.9 μg/mL, respectively. The bactericidal activity of abscisic acid (at 10.8 μg/mL corresponding to 4 × MIC) killed the organism within 36-72 h. These results suggest that abscisic acid isolated from Korean acacia honey has antibacterial activity against H. pylori . Abscisic acid isolated from Korean acacia honey can be therapeutic and may be further exploited as a potential lead candidate for the development of treatments for H. pylori -induced infections. The crude acacia honey was extracted with n -hexane, dichloromethane, EtOAc, and n -butanolThe EtOAc extract yielded eight fractions and four subfractions were subsequently obtained chromatographicallyAbscisic acid was isolated from one subfractionAll the solvent extracts and fractions showed antibacterial activity against H. pylori Abscisic acid exhibited antibacterial activity against H. pylori . Abbreviations used: MeOH: Methanol; EtOAc: Ethyl acetate; TSB: Trypticase

  13. A biorefinery approach based on fractionation with a cheap industrial by-product for getting value from an invasive woody species.

    PubMed

    Domínguez, Elena; Romaní, Aloia; Alonso, José Luis; Parajó, Juan Carlos; Yáñez, Remedios

    2014-12-01

    Acacia dealbata wood (an invasive species) was subjected to fractionation with glycerol (a cheap industrial by-product), and the resulting solid phase was used as a substrate for enzymatic hydrolysis. Glycerol fractionation allowed an extensive delignification while preserving cellulose in solid phase. The solids from the fractionation stage showed high susceptibility to enzymatic hydrolysis. Solids obtained under selected fractionation conditions (glycerol content of media, 80 wt%; duration, 1h; liquid to solid ratio, 6 g/g; alkaline and neutral washing stages) were subjected to enzymatic saccharification to achieve glucose concentrations up to 85.40 g/L, with almost complete cellulose conversion into glucose. The results confirmed the potential of glycerol as a fractionation agent for biorefineries. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Improved Mannanase Production from Penicillium occitanis by Fed-Batch Fermentation Using Acacia Seeds

    PubMed Central

    Blibech, Monia; Ellouz Ghorbel, Raoudha; Chaari, Fatma; Dammak, Ilyes; Bhiri, Fatma; Neifar, Mohamed; Ellouz Chaabouni, Semia

    2011-01-01

    By applying a fed-batch strategy, production of Penicillium occitanis mannanases could be almost doubled as compared to a batch cultivation on acacia seeds (76 versus 41 U/mL). Also, a 10-fold increase of enzyme activities was observed from shake flask fermentation to the fed-batch fermentation. These production levels were 3-fold higher than those obtained on coconut meal. The high mannanase production using acacia seeds powder as inducer substrate showed the suitability of this culture process for industrial-scale development. PMID:23724314

  15. Multitasking in a plant-ant interaction: how does Acacia myrtifolia manage both ants and pollinators?

    PubMed

    Martínez-Bauer, Angélica E; Martínez, Gerardo Cerón; Murphy, Daniel J; Burd, Martin

    2015-06-01

    Plant associations with protective ants are widespread among angiosperms, but carry the risk that ants will deter pollinators as well as herbivores. Such conflict, and adaptations to ameliorate or prevent the conflict, have been documented in African and neotropical acacias. Ant-acacia associations occur in Australia, but little is known of their ecology. Moreover, recent phylogenetic evidence indicates that Australian acacias are only distantly related to African and American acacias, providing an intercontinental natural experiment in the management of ant-pollinator conflict. We examined four populations of Acacia myrtifolia over a 400-km environmental gradient in southeastern Australia using ant and pollinator exclusion as well as direct observation of ants and pollinators to assess the potential for ant-pollinator conflict to affect seed set. Native bees were the only group of floral visitors whose visitation rates were a significant predictor of fruiting success, although beetles and wasps may play an important role as "insurance" pollinators. We found no increase in pollinator visitation or fruiting success following ant exclusion, even with large sample sizes and effective exclusion. Because ants are facultative visitors to A. myrtifolia plants, their presence may be insufficient to interfere greatly with floral visitors. It is also likely that the morphological location of extrafloral nectaries tends to draw ants away from reproductive parts, although we commonly observed ants on inflorescences, so the spatial separation is not strict. A. myrtifolia appears to maintain a generalized mutualism over a wide geographic range without the need for elaborate adaptations to resolve ant-pollinator conflict.

  16. Interfacial rheology of surface-active biopolymers: Acacia senegal gum versus hydrophobically modified starch.

    PubMed

    Erni, Philipp; Windhab, Erich J; Gunde, Rok; Graber, Muriel; Pfister, Bruno; Parker, Alan; Fischer, Peter

    2007-11-01

    Acacia gum is a hybrid polyelectrolyte containing both protein and polysaccharide subunits. We study the interfacial rheology of its adsorption layers at the oil/water interface and compare it with adsorbed layers of hydrophobically modified starch, which for economic and political reasons is often used as a substitute for Acacia gum in technological applications. Both the shear and the dilatational rheological responses of the interfaces are considered. In dilatational experiments, the viscoelastic response of the starch derivative is just slightly weaker than that for Acacia gum, whereas we found pronounced differences in shear flow: The interfaces covered with the plant gum flow like a rigid, solidlike material with large storage moduli and a linear viscoelastic regime limited to small shear deformations, above which we observe apparent yielding behavior. In contrast, the films formed by hydrophobically modified starch are predominantly viscous, and the shear moduli are only weakly dependent on the deformation. Concerning their most important technological use as emulsion stabilizers, the dynamic interfacial responses imply not only distinct interfacial dynamics but also different stabilizing mechanisms for these two biopolymers.

  17. Influence of xanthan, guar, CMC and gum acacia on functional properties of water chestnut (Trapa bispinosa) starch.

    PubMed

    Lutfi, Zubala; Nawab, Anjum; Alam, Feroz; Hasnain, Abid; Haider, Syed Zia

    2017-10-01

    This study was performed to determine the effect of xanthan, guar, CMC and gum acacia on functional and pasting properties of starch isolated from water chestnut (Trapa bispinosa). Morphological properties of water chestnut starch with CMC were studied by scanning electron microscopy (SEM). The addition of hydrocolloids significantly enhanced the solubility of water chestnut starch (WCS) while reduced swelling power and freeze-thaw stability. The hydrophilic tendency of WCS was increased by xanthan gum; however, with addition of gum acacia it decreased significantly. Starch was modified with guar and gum acacia exhibited highest% syneresis. Guar gum was found to be effective in increasing the clarity of water chestnut starch paste. The addition of CMC significantly reduced the pasting temperature of WCS indicating ease of gelatinization. The setback was accelerated in the presence of xanthan gum but gum acacia delayed this effect during the cooling of the starch paste. Only xanthan gum was found to be effective in increasing breakdown showing good paste stability of WCS. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Two-year variations of phenolics, flavonoids and antioxidant contents in acacia honey.

    PubMed

    Moniruzzaman, Mohammed; Sulaiman, Siti Amrah; Azlan, Siti Amirah Mohd; Gan, Siew Hua

    2013-11-27

    Honey is a good source of several important chemical compounds and antioxidants and is harvested throughout the year. However, no study has determined how their contents change over the years. The aim of the present research was to investigate the changes in the phenolics, flavonoids and antioxidant properties, as well as other physicochemical properties, of Malaysian acacia honey collected during different months during a two year period. The DPPH (1,1-diphenyl-2-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) methods were used to determine the total antioxidant activity of the honey samples. Generally, honey samples collected in the beginning and the middle of the year tended to have higher sugar content, which may be attributed to its high acidic nature and low moisture content. There was a gradual increase in the phenolic content of the acacia honey samples collected between September 2010 and December 2010. The honey sample collected at the beginning of the year (January) showed the highest color intensity and was dark amber in color. It also contained the highest concentration of phenolic compounds (341.67 ± 2.94 mg(gallic acid)/kg), the highest flavonoid content (113.06 ± 6.18 mg(catechin)/kg) and the highest percentage of DPPH inhibition and the highest FRAP value, confirming its high antioxidant potential. There was a positive correlation between DPPH and total phenolic content, suggesting that phenolic compounds are the strongest contributing factor to the radical scavenging activity of Malaysian acacia honeys. Overall, our results indicated that there were significant seasonal variations in the antioxidant potentials of honey over the two year period and the time of honey collection affects its physicochemical properties. Therefore, acacia honey from Malaysia should ideally be collected during the dry season, particularly in the months of January, May and June.

  19. Risk assessment, eradication, and biological control: global efforts to limit Australian acacia invasions

    USGS Publications Warehouse

    Wilson, John R.U.; Gairifo, Carla; Gibson, Michelle R.; Arianoutsou, Margarita; Bakar, Baki B.; Baret, Stephane; Celesti-Grapow, Laura; DiTomaso, Joseph M.; Dufour-Dror, Jean-Marc; Kueffer, Christoph; Kull, Christian A.; Hoffman, John H.; Impson, Fiona A.C.; Loope, Lloyd L.; Marchante, Elizabete; Harchante, Helia; Moore, Joslin L.; Murphy, Daniel J.; Tassin, Jacques; Witt, Arne; Zenni, Rafael D.; Richardson, David M.

    2011-01-01

    Aim Many Australian Acacia species have been planted around the world, some are highly valued, some are invasive, and some are both highly valued and invasive. We review global efforts to minimize the risk and limit the impact of invasions in this widely used plant group. Location Global. Methods Using information from literature sources, knowledge and experience of the authors, and the responses from a questionnaire sent to experts around the world, we reviewed: (1) a generalized life cycle of Australian acacias and how to control each life stage, (2) different management approaches and (3) what is required to help limit or prevent invasions. Results Relatively few Australian acacias have been introduced in large numbers, but all species with a long and extensive history of planting have become invasive somewhere. Australian acacias, as a group, have a high risk of becoming invasive and causing significant impacts as determined by existing assessment schemes. Moreover, in most situations, long-lived seed banks mean it is very difficult to control established infestations. Control has focused almost exclusively on widespread invaders, and eradication has rarely been attempted. Classical biological control is being used in South Africa with increasing success. Main conclusions A greater emphasis on pro-active rather than reactive management is required given the difficulties managing established invasions of Australian acacias. Adverse effects of proposed new introductions can be minimized by conducting detailed risk assessments in advance, planning for on-going monitoring and management, and ensuring resources are in place for long-term mitigation. Benign alternatives (e.g. sterile hybrids) could be developed to replace existing utilized taxa. Eradication should be set as a management goal more often to reduce the invasion debt. Introducing classical biological control agents that have a successful track-record in South Africa to other regions and identifying new

  20. Detailed Chemical Composition of Condensed Tannins via Quantitative (31)P NMR and HSQC Analyses: Acacia catechu, Schinopsis balansae, and Acacia mearnsii.

    PubMed

    Crestini, Claudia; Lange, Heiko; Bianchetti, Giulia

    2016-09-23

    The chemical composition of Acacia catechu, Schinopsis balansae, and Acacia mearnsii proanthocyanidins has been determined using a novel analytical approach that rests on the concerted use of quantitative (31)P NMR and two-dimensional heteronuclear NMR spectroscopy. This approach has offered significant detailed information regarding the structure and purity of these complex and often elusive proanthocyanidins. More specifically, rings A, B, and C of their flavan-3-ol units show well-defined and resolved absorbance regions in both the quantitative (31)P NMR and HSQC spectra. By integrating each of these regions in the (31)P NMR spectra, it is possible to identify the oxygenation patterns of the flavan-3-ol units. At the same time it is possible to acquire a fingerprint of the proanthocyanidin sample and evaluate its purity via the HSQC information. This analytical approach is suitable for both the purified natural product proanthocyanidins and their commercial analogues. Overall, this effort demonstrates the power of the concerted use of these two NMR techniques for the structural elucidation of natural products containing labile hydroxy protons and a carbon framework that can be traced out via HSQC.

  1. Mixing of acacia bark and palm shells to increase caloric value of palm shells white charcoal briquette

    NASA Astrophysics Data System (ADS)

    Kurniawan, Edy Wibowo; Amirta, Rudianto; Budiarso, Edy; Arung, Enos Tangke

    2017-06-01

    Indonesia is greatly rich in biomass resources. Acacia bark waste utilization as a source of biomass is still very low, where as 10-20% of the potential of the wood. On the other hand waste palm shells have been partly utilized as boiler fuel oil plant as much as 62.4%, but the rest is still a waste pile or to the hardening of the estate path. This study aims to determine the effect of mixing an acacia bark with palm shells to increase the calorific value of palm shell white charcoal briquettes. The study was conducted by making white charcoal briquettes mixing 7% the acacia bark against of palm shells. As well as white charcoal briquettes control without any acacia bark. Then molds the briquettes in pyrolysis temperature at 600 ° C, 700 ° C and 800 ° C for pyrolysis time within 2 hours, 4 hours, and 6 hours. And the results of briquettes analysis in calorific value. The results showed that the caloric value of palm shell white charcoal briquettes increased from 29691.14 Kcal / kg to 31941.50 Kcal / kg.

  2. Arabinogalactan Proteins From Baobab and Acacia Seeds Influence Innate Immunity of Human Keratinocytes In Vitro.

    PubMed

    Zahid, Abderrakib; Despres, Julie; Benard, Magalie; Nguema-Ona, Eric; Leprince, Jerome; Vaudry, David; Rihouey, Christophe; Vicré-Gibouin, Maité; Driouich, Azeddine; Follet-Gueye, Marie-Laure

    2017-09-01

    Plant derived arabinogalactan proteins (AGP) were repeatedly confirmed as immunologically as well as dermatologically active compounds. However, little is currently known regarding their potential activity toward skin innate immunity. Here, we extracted and purified AGP from acacia (Acacia senegal) and baobab (Adansonia digitata) seeds to investigate their biological effects on the HaCaT keratinocyte cell line in an in vitro system. While AGP from both sources did not exhibit any cytotoxic effect, AGP from acacia seeds enhanced cell viability. Moreover, real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis showed that AGP extracted from both species induced a substantial overexpression of hBD-2, TLR-5, and IL1-α genes. These data suggest that plant AGP, already known to control plant defensive processes, could also modulate skin innate immune responses. J. Cell. Physiol. 232: 2558-2568, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Individual based, long term monitoring of acacia trees in hyper arid zone: Integration of a field survey and a remote sensing approach

    NASA Astrophysics Data System (ADS)

    Isaacson, Sivan; Blumberg, Dan G.; Ginat, Hanan; Shalmon, Benny

    2013-04-01

    Vegetation in hyper arid zones is very sparse as is. Monitoring vegetation changes in hyper arid zones is important because any reduction in the vegetation cover in these areas can lead to a considerable reduction in the carrying capacity of the ecological system. This study focuses on the impact of climate fluctuations on the acacia population in the southern Arava valley, Israel. The period of this survey includes a sequence of dry years with no flashfloods in most of the plots that ended in two years with vast floods. Arid zone acacia trees play a significant role in the desert ecosystem by moderating the extreme environmental conditions including radiation, temperature, humidity and precipitation. The trees also provide nutrients for the desert dwellers. Therefore, acacia trees in arid zones are considered to be `keystone species', because they have major influence over both plants and animal species, i.e., biodiversity. Long term monitoring of the acacia tree population in this area can provide insights into long term impacts of climate fluctuations on ecosystems in arid zones. Since 2000, a continuous yearly based survey on the three species of acacia population in seven different plots is conducted in the southern Arava (established by Shalmon, ecologist of the Israel nature and parks authority). The seven plots representing different ecosystems and hydrological regimes. A yearly based population monitoring enabled us to determine the mortality and recruitment rate of the acacia populations as well as growing rates of individual trees. This survey provides a unique database of the acacia population dynamics during a sequence of dry years that ended in a vast flood event during the winter of 2010. A lack of quantitative, nondestructive methods to estimate and monitor stress status of the acacia trees, led us to integrate remote sensing tools (ground and air-based) along with conventional field measurements in order to develop a long term monitoring of acacia

  4. Tannins from Acacia mearnsii De Wild. Bark: Tannin Determination and Biological Activities.

    PubMed

    Ogawa, Sosuke; Yazaki, Yoshikazu

    2018-04-05

    The bark of Acacia mearnsii De Wild. (black wattle) contains significant amounts of water-soluble components acalled "wattle tannin". Following the discovery of its strong antioxidant activity, a wattle tannin dietary supplement has been developed and as part of developing new dietary supplements, a literature search was conducted using the SciFinder data base for " Acacia species and their biological activities". An analysis of the references found indicated that the name of Acacia nilotica had been changed to Vachellia nilotica , even though the name of the genus Acacia originated from its original name. This review briefly describes why and how the name of A. nilotica changed. Tannin has been analyzed using the Stiasny method when the tannin is used to make adhesives and the hide-powder method is used when the tannin is to be used for leather tanning. A simple UV method is also able to be used to estimate the values for both adhesives and leather tanning applications. The tannin content in bark can also be estimated using NIR and NMR. Tannin content estimations using pyrolysis/GC, electrospray mass spectrometry and quantitative 31 P-NMR analyses have also been described. Tannins consists mostly of polyflavanoids and all the compounds isolated have been updated. Antioxidant activities of the tannin relating to anti-tumor properties, the viability of human neuroblastoma SH-SY5Y cells and also anti-hypertensive effects have been studied. The antioxidant activity of proanthocyanidins was found to be higher than that of flavan-3-ol monomers. A total of fourteen papers and two patents reported the antimicrobial activities of wattle tannin. Bacteria were more susceptible to the tannins than the fungal strains tested. Several bacteria were inhibited by the extract from A. mearnsii bark. The growth inhibition mechanisms of E. coli were investigated. An interaction between extracts from A. mearnsii bark and antibiotics has also been studied. The extracts from A. mearnsii

  5. Ameliorative Effects of Acacia Honey against Sodium Arsenite-Induced Oxidative Stress in Some Viscera of Male Wistar Albino Rats.

    PubMed

    Aliyu, Muhammad; Ibrahim, Sani; Inuwa, Hajiya M; Sallau, Abdullahi B; Abbas, Olagunju; Aimola, Idowu A; Habila, Nathan; Uche, Ndidi S

    2013-01-01

    Cancer is a leading cause of death worldwide and its development is frequently associated with oxidative stress-induced by carcinogens such as arsenicals. Most foods are basically health-promoting or disease-preventing and a typical example of such type is honey. This study was undertaken to investigate the ameliorative effects of Acacia honey on sodium arsenite-induced oxidative stress in the heart, lung and kidney tissues of male Wistar rats. Male Wistar albino rats divided into four groups of five rats each were administered distilled water, Acacia honey (20%), sodium arsenite (5 mg/kg body weight), Acacia honey, and sodium arsenite daily for one week. They were sacrificed anesthetically using 60 mg/kg sodium pentothal. The tissues were used for the assessment of glutathione peroxidase, catalase, and superoxide dismutase activities, protein content and lipid peroxidation. Sodium arsenite significantly (P < 0.05) suppressed the glutathione peroxidase, catalase, superoxide dismutase activities with simultaneous induction of lipid peroxidation. Administration of Acacia honey significantly increased (P < 0.05) glutathione peroxidase, catalase, and superoxide dismutase activities with concomitant suppression of lipid peroxidation as evident by the decrease in malondialdehyde level. From the results obtained, Acacia honey mitigates sodium arsenite induced-oxidative stress in male Wistar albino rats, which suggest that it may attenuate oxidative stress implicated in chemical carcinogenesis.

  6. Climate trends in the wood anatomy of Acacia sensu stricto (Leguminosae: Mimosoideae)

    PubMed Central

    Warwick, Nigel W. M.; Hailey, Luke; Clarke, Kerri L.

    2017-01-01

    Abstract Background and Aims This study investigates the structural diversity of the secondary xylem of 54 species of Acacia from four taxonomic sections collected across five climate regions along a 1200 km E–W transect from sub-tropical [approx. 1400 mm mean annual precipitation (MAP)] to arid (approx. 240 mm MAP) in New South Wales, Australia. Acacia sensu stricto (s.s.) is a critical group for understanding the effect of climate and phylogeny on the functional anatomy of wood. Methods Wood samples were sectioned in transverse, tangential and radial planes for light microscopy and analysis. Key Results The wood usually has thick-walled vessels and fibres, paratracheal parenchyma and uniseriate and biseriate rays, occasionally up to four cells wide. The greater abundance of gelatinous fibres in arid and semi-arid species may have ecological significance. Prismatic crystals in chambered fibres and axial parenchyma increased in abundance in semi-arid and arid species. Whereas vessel diameter showed only a small decrease from the sub-tropical to the arid region, there was a significant 2-fold increase in vessel frequency and a consequent 3-fold decrease in the vulnerability index. Conclusions Although the underlying phylogeny determines the qualitative wood structure, climate has a significant influence on the functional wood anatomy of Acacia s.s., which is an ideal genus to study the effect of these factors. PMID:28334287

  7. Influence of carbonization conditions on the pyrolytic carbon deposition in acacia and eucalyptus wood chars

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

    Kumar, M.; Gupta, R.C.

    1997-04-01

    The amount of deposited pyrolytic carbon (resulting from the cracking of volatile matter) was found to depend on wood species and carbonization conditions, such as temperature and heating rate. Maximum pyrolytic carbon deposition in both the acacia and eucalyptus wood chars has been observed at a carbonization temperature of 800 C. Rapid carbonization (higher heating rate) of wood significantly reduces the amount of deposited pyrolytic carbon in resulting chars. Results also indicate that the amount of deposited pyrolytic carbon in acacia wood char is less than that in eucalyptus wood char.

  8. Flash pyrolysis of forestry residues from the Portuguese Central Inland Region within the framework of the BioREFINA-Ter project.

    PubMed

    Amutio, Maider; Lopez, Gartzen; Alvarez, Jon; Moreira, Rui; Duarte, Gustavo; Nunes, Joao; Olazar, Martin; Bilbao, Javier

    2013-02-01

    The feasibility of the valorization by flash pyrolysis of forest shrub wastes, namely bushes (Cytisus multiflorus, Spartium junceum, Acacia dealbata and Pterospartum tridentatum) has been studied in a conical spouted bed reactor operating at 500 °C, with a continuous biomass feed and char removal. High bio-oil yields in the 75-80 wt.% range have been obtained for all of the materials, with char yields between 16 and 23 wt.% and low gas yields (4-5 wt.%). Bio-oils are composed mainly of water (accounting for a concentration in the 34-40 wt.% range in the bio-oil), phenols, ketones, acids and furans, with lower contents of saccharides, aldehydes and alcohols. Although their composition depends on the raw material, the compounds are similar to those obtained with more conventional feedstocks. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Feasibility study of determination of high-fructose syrup content of Acacia honey by terahertz technique

    NASA Astrophysics Data System (ADS)

    Liu, Wen; Zhang, Yuying; Han, Donghai

    2016-11-01

    The authenticity problem of honey with difficult identification and great economic value highlights the certain limitations of the existing examination methods to distinguish the inauthentic honey. Terahertz technique is sensitive to water and has abundant information about saccharides' intermolecular interactions . This paper is tried to determine high-fructose-syrup content of Acacia honey by terahertz technique combined with chemometric methods. RMSEC and RMSEP of PLS model was 0.0967 and 0.108, respectively, confirming the reliability of the technique. This work shows that it was possible to determine high-fructose-syrup content of Acacia honey by terahertz technique.

  10. Stimulating growth of stagnated Acacia koa by thinning and fertilizing

    Treesearch

    Paul G. Scowcroft; John D. Stein

    1986-01-01

    Building Acacia koa, Hawaii's most marketable native tree, into a viable resource is economically and eco1ogically desirable. But little is known about natural stand development and management of this scarce resource. Therefore, the effect of thinning, fertilizing, or both on short-term growth and survival was studied in a stagnated 12-year-old...

  11. Colloids removal from water resources using natural coagulant: Acacia auriculiformis

    NASA Astrophysics Data System (ADS)

    Abdullah, M.; Roslan, A.; Kamarulzaman, M. F. H.; Erat, M. M.

    2017-09-01

    All waters, especially surface waters contain dissolved, suspended particles and/or inorganic matter, as well as several biological organisms, such as bacteria, algae or viruses. This material must be removed because it can affect the water quality that can cause turbidity and colour. The objective of this study is to develop water treatment process from Seri Alam (Johor, Malaysia) lake water resources by using natural coagulant Acacia auriculiformis pods through a jar test experiment. Jar test is designed to show the effectiveness of the water treatment. This process is a laboratory procedure that will simulate coagulation/flocculation with several parameters selected namely contact time, coagulant dosage and agitation speed. The most optimum percentage of colloids removal for each parameter is determined at 0.2 g, 90 min and 80 rpm. FESEM (Field-emission Scanning Electron Microscope) observed the small structures of final floc particles for optimum parameter in this study to show that the colloids coagulated the coagulant. All result showed that the Acacia auriculiformis pods can be a very efficient coagulant in removing colloids from water.

  12. Phylogeny of nodulation genes and symbiotic diversity of Acacia senegal (L.) Willd. and A. seyal (Del.) Mesorhizobium strains from different regions of Senegal.

    PubMed

    Bakhoum, Niokhor; Galiana, Antoine; Le Roux, Christine; Kane, Aboubacry; Duponnois, Robin; Ndoye, Fatou; Fall, Dioumacor; Noba, Kandioura; Sylla, Samba Ndao; Diouf, Diégane

    2015-04-01

    Acacia senegal and Acacia seyal are small, deciduous legume trees, most highly valued for nitrogen fixation and for the production of gum arabic, a commodity of international trade since ancient times. Symbiotic nitrogen fixation by legumes represents the main natural input of atmospheric N2 into ecosystems which may ultimately benefit all organisms. We analyzed the nod and nif symbiotic genes and symbiotic properties of root-nodulating bacteria isolated from A. senegal and A. seyal in Senegal. The symbiotic genes of rhizobial strains from the two Acacia species were closed to those of Mesorhizobium plurifarium and grouped separately in the phylogenetic trees. Phylogeny of rhizobial nitrogen fixation gene nifH was similar to those of nodulation genes (nodA and nodC). All A. senegal rhizobial strains showed identical nodA, nodC, and nifH gene sequences. By contrast, A. seyal rhizobial strains exhibited different symbiotic gene sequences. Efficiency tests demonstrated that inoculation of both Acacia species significantly affected nodulation, total dry weight, acetylene reduction activity (ARA), and specific acetylene reduction activity (SARA) of plants. However, these cross-inoculation tests did not show any specificity of Mesorhizobium strains toward a given Acacia host species in terms of infectivity and efficiency as stated by principal component analysis (PCA). This study demonstrates that large-scale inoculation of A. senegal and A. seyal in the framework of reafforestation programs requires a preliminary step of rhizobial strain selection for both Acacia species.

  13. Extracting Features of Acacia Plantation and Natural Forest in the Mountainous Region of Sarawak, Malaysia by ALOS/AVNIR2 Image

    NASA Astrophysics Data System (ADS)

    Fadaei, H.; Ishii, R.; Suzuki, R.; Kendawang, J.

    2013-12-01

    The remote sensing technique has provided useful information to detect spatio-temporal changes in the land cover of tropical forests. Land cover characteristics derived from satellite image can be applied to the estimation of ecosystem services and biodiversity over an extensive area, and such land cover information would provide valuable information to global and local people to understand the significance of the tropical ecosystem. This study was conducted in the Acacia plantations and natural forest situated in the mountainous region which has different ecological characteristic from that in flat and low land area in Sarawak, Malaysia. The main objective of this study is to compare extract the characteristic of them by analyzing the ALOS/AVNIR2 images and ground truthing obtained by the forest survey. We implemented a ground-based forest survey at Aacia plantations and natural forest in the mountainous region in Sarawak, Malaysia in June, 2013 and acquired the forest structure data (tree height, diameter at breast height (DBH), crown diameter, tree spacing) and spectral reflectance data at the three sample plots of Acacia plantation that has 10 x 10m area. As for the spectral reflectance data, we measured the spectral reflectance of the end members of forest such as leaves, stems, road surface, and forest floor by the spectro-radiometer. Such forest structure and spectral data were incorporated into the image analysis by support vector machine (SVM) and object-base/texture analysis. Consequently, land covers on the AVNIR2 image were classified into three forest types (natural forest, oil palm plantation and acacia mangium plantation), then the characteristic of each category was examined. We additionally used the tree age data of acacia plantation for the classification. A unique feature was found in vegetation spectral reflectance of Acacia plantations. The curve of the spectral reflectance shows two peaks around 0.3μm and 0.6 - 0.8μm that can be assumed to

  14. NAS: The first year

    NASA Technical Reports Server (NTRS)

    Bailey, F. R.; Kutler, Paul

    1988-01-01

    Discussed are the capabilities of NASA's Numerical Aerodynamic Simulation (NAS) Program and its application as an advanced supercomputing system for computational fluid dynamics (CFD) research. First, the paper describes the NAS computational system, called the NAS Processing System Network, and the advanced computational capabilities it offers as a consequence of carrying out the NAS pathfinder objective. Second, it presents examples of pioneering CFD research accomplished during NAS's first operational year. Examples are included which illustrate CFD applications for predicting fluid phenomena, complementing and supplementing experimentation, and aiding in design. Finally, pacing elements and future directions for CFD and NAS are discussed.

  15. Acacia catechu Ethanolic Seed Extract Triggers Apoptosis of SCC-25 Cells.

    PubMed

    Lakshmi, Thangavelu; Ezhilarasan, Devaraj; Nagaich, Upendra; Vijayaragavan, Rajagopal

    2017-10-01

    Acacia catechu Willd ( Fabaceae ), commonly known as catechu, cachou, and black cutch, has been studied for its hepatoprotective, antipyretic, antidiarrheal, hypoglycemic, anti-inflammatory, immunomodulatory, antinociceptive, antimicrobial, free radical scavenging, and antioxidant activities. We evaluated the cytotoxic activity of ethanol extract of A. catechu seed (ACS) against SCC-25 human oral squamous carcinoma cell line. Cytotoxic effect of ACS extract was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, using concentrations of 0.1-1000 μg/mL for 24 h. A. catechu ethanol seed extract was treated SCC-25 cells with 25 and 50 μg/mL. At the end of treatment period, apoptotic marker gene expressions such as caspase 8, 9, Bcl-2, Bax, and cytochrome c were evaluated by semiquantitative reverse transcription-polymerase chain reaction. Morphological changes of ACS treated SCC-25 cells was evaluated by acridine orange/ethidium bromide (AO/EB) dual staining. Nuclear morphology and DNA fragmentation was evaluated by propidium iodide (PI) staining. A. catechu ethanol seed extract treatment caused cytotoxicity in SCC-25 cells with an IC 50 value of 100 μg/mL. Apoptotic markers caspases 8 and 9, cytochrome c, Bax gene expressions were significantly increased upon ACS extract treatment indicate the apoptosis induction in SCC-25 cells. This treatment also caused significant downregulation of Bcl-2 gene expression. Staining with AO/EB and PI shows membrane blebbing, and nuclear membrane distortion further confirms the apoptosis induction by ACS treatment in SCC-25 cells. The ethanol seed extracts of A. catechu was found to be cytotoxic at lower concentrations and induced apoptosis in human oral squamous carcinoma SCC-25 cells. Acacia catechu ethanolic seed extract contains phytochemicals such as epicatechin, rutin, and quercetin Acacia catechu seed (ACS) extract significantly ( P < 0.001) inhibits the active proliferation of human oral

  16. Impact of Acacia tortilis ssp. raddiana tree on wheat and barley yield in the south of Tunisia

    NASA Astrophysics Data System (ADS)

    Noumi, Zouhaier; Abdallah, Fathia; Torre, Franck; Michalet, Richard; Touzard, Blaise; Chaieb, Mohamed

    2011-03-01

    In the past, Acacia tortilis ssp. raddiana (Savi) Brenan colonised thousands of hectares in central and southern Tunisia. Nowadays, the geographical distribution of A. tortilis ssp. raddiana is restricted to the National Park of Bou-Hedma (central Tunisia). The Acacia is of considerable interest for local populations and may be considered as a "foundation species" under arid climate. This study examines the effects of Acacia canopy on soil fertility and cereal productivity. The improvement in soil fertility and microclimate provided by A. tortilis ssp. raddiana is known to facilitate the establishment of new species, but little is known about the interaction between the tree species and the cereals cultivated by local farmers. We studied the effect of A. tortilis ssp. raddiana canopy on the yield of three cereals crops ( Hordeum vulgare L., Triticum sativum L. and Triticum aestivum L.). We seeded 168 plots (15 × 15 m) under the tree canopy and in open areas on four different landform types (glacis, plain, wadis, and jessours) and measured cereal yield over two contrasting years (wet and dry). We found that: (1) precipitation and geomorphology are more important in determining cereal yield than canopy cover, (2) these effects on water availability are species-specific with no effect on the stress-tolerant barley. We finally discuss the potential negative effects of Acacia trees which may have balanced the positive effects found for nutrient in our study.

  17. [Discrimination of Rice Syrup Adulterant of Acacia Honey Based Using Near-Infrared Spectroscopy].

    PubMed

    Zhang, Yan-nan; Chen, Lan-zhen; Xue, Xiao-feng; Wu, Li-ming; Li, Yi; Yang, Juan

    2015-09-01

    At present, the rice syrup as a low price of the sweeteners was often adulterated into acacia honey and the adulterated honeys were sold in honey markets, while there is no suitable and fast method to identify honey adulterated with rice syrup. In this study, Near infrared spectroscopy (NIR) combined with chemometric methods were used to discriminate authenticity of honey. 20 unprocessed acacia honey samples from the different honey producing areas, mixed? with different proportion of rice syrup, were prepared of seven different concentration gradient? including 121 samples. The near infrared spectrum (NIR) instrument and spectrum processing software have been applied in the? spectrum? scanning and data conversion on adulterant samples, respectively. Then it was analyzed by Principal component analysis (PCA) and canonical discriminant analysis methods in order to discriminating adulterated honey. The results showed that after principal components analysis, the first two principal components accounted for 97.23% of total variation, but the regionalism of the score plot of the first two PCs was not obvious, so the canonical discriminant analysis was used to make the further discrimination, all samples had been discriminated correctly, the first two discriminant functions accounted for 91.6% among the six canonical discriminant functions, Then the different concentration of adulterant samples can be discriminated correctly, it illustrate that canonical discriminant analysis method combined with NIR spectroscopy is not only feasible but also practical for rapid and effective discriminate of the rice syrup adulterant of acacia honey.

  18. Applied genetic conservation of Hawaiian Acacia koa: an eco-regional approach

    Treesearch

    Nick Dudley; Tyler Jones; Robert James; Richard Sniezko; Jessica Wright; Christina Liang; Paul F. Gugger; Phil Cannon

    2017-01-01

    Koa (Acacia koa) is a valuable tree species economically, ecologically, and culturally in Hawaii. A vascular wilt disease of koa, caused by the fungal pathogen Fusarium oxysporum f. sp. koae (FOXY), causes high rates of mortality in field plantings and threatens native koa forests in Hawaii. Producing seeds with genetic resistance to FOXY is vital...

  19. Hemostatic, antibacterial biopolymers from Acacia arabica (Lam.) Willd. and Moringa oleifera (Lam.) as potential wound dressing materials.

    PubMed

    Bhatnagar, Monica; Parwani, Laxmi; Sharma, Vinay; Ganguli, Jhuma; Bhatnagar, Ashish

    2013-10-01

    Acacia arabica and Moringa oleifera are credited with a number of medicinal properties. Traditionally gum of Acacia plant is used in the treatment of skin disorders to soothe skin rashes, soreness, inflammation and burns while Moringa seed extracts are known to have antibacterial activity. In the present study the potential of the polymeric component of aqueous extracts of gum acacia (GA) and the seeds of M. oleifera (MSP) in wound management was evaluated. The results revealed that both biopolymers were hemostatic and hasten blood coagulation. They showed shortening of activated partial thromboplastin time and prothrombin time and were non-cytotoxic in nature. Both showed antibacterial activity against organisms known to be involved in wound infections with MIC ranging from 500-600 microg mL(-1) for GA and 300-700 microg mL(-1) for MSP. They were biodegradable and exhibited water absorption capacity in the range of 415 to 935%. The hemostatic character coupled to these properties envisions their potential in preparation of dressings for bleeding and profusely exuding wounds. The biopolymers have been further analysed for their composition by Gas chromatography.

  20. Invasive Australian Acacia seed banks: Size and relationship with stem diameter in the presence of gall-forming biological control agents.

    PubMed

    Strydom, Matthys; Veldtman, Ruan; Ngwenya, Mzabalazo Z; Esler, Karen J

    2017-01-01

    Australian Acacia are invasive in many parts of the world. Despite significant mechanical and biological efforts to control their invasion and spread, soil-stored seed banks prevent their effective and sustained removal. In response South Africa has had a strong focus on employing seed reducing biological control agents to deal with Australian Acacia invasion, a programme that is considered as being successful. To provide a predictive understanding for their management, seed banks of four invasive Australian acacia species (Acacia longifolia, A. mearnsii, A. pycnantha and A. saligna) were studied in the Western Cape of South Africa. Across six to seven sites for each species, seed bank sizes were estimated from dense, monospecific stands by collecting 30 litter and soil samples. Average estimated seed bank size was large (1017 to 17261 seed m-2) as was annual input into the seed bank, suggesting that these seed banks are not residual but are replenished in size annually. A clear relationship between seed bank size and stem diameter was established indicating that mechanical clearing should be conducted shortly after fire-stimulated recruitment events or within old populations when seed banks are small. In dense, monospecific stands seed-feeding biological control agents are not effective in reducing seed bank size.

  1. [Study on the nitrogen and phosphorus uptake ability of four plants cultivated on floating-bed].

    PubMed

    Wu, Jian-Qiang; Wang, Min; Wu, Jian; Jiang, Yue; Sun, Cong-Jun; Cao, Yong

    2011-04-01

    Plant floating-bed tested engineering was constructed for eutrophication control in Dian-shan Lake, the characteristics and nutrient uptake abilities of Canna indica, Iris pseudacorus, Thalia dealbata and Lythrum salicaria were compared. It shows that using upper and lower nylon nets to fix the plants on the floating-bed is beneficial for them to grow and reproduce rapidly. Survival rates of Canna indica, lris pseudacorus, Thalia dealbata and Lythrum salicaria are 83.33%, 83.33%, 76.67% and 53.33% respectively. Ramets of Canna indica and Thalia dealbata are 64 and 78 respectively in November, and the biomass (fresh weight) of these two plants are 32.0 and 38.6 kg per individual plant. Nitrogen (N) and phosphorus (P) content in stems/leaves of Canna indica and Thalia dealbata are greater than those in roots. The ratio between stems/leaves and roots of N, P content in Canna indica are 1.40 and 1.21 respectively, while 1.59 and 1.08 in Thalia dealbata. The difference of cumulative N, P content in plants is mostly on account of different plant biomass. N uptake ability of Thalia dealbata is the highest, which is 457.11 g per square; Canna indica has the highest P uptake ability, which is 41.29 g per square. N, P uptake ability of stems/leaves in Canna indica are 2.17 and 1.86 times higher than that of roots, while 1.73 and 1.17 times higher respectively in Thalia dealbata. Thus, Canna indica and Thalia dealbata are recommended as the floating-bed plants to control the eutrophication in Dian-shan Lake.

  2. Precipitation of calcium, magnesium, strontium and barium in tissues of four Acacia species (Leguminosae: Mimosoideae).

    PubMed

    He, Honghua; Bleby, Timothy M; Veneklaas, Erik J; Lambers, Hans; Kuo, John

    2012-01-01

    Precipitation of calcium in plants is common. There are abundant studies on the uptake and content of magnesium, strontium and barium, which have similar chemical properties to calcium, in comparison with those of calcium in plants, but studies on co-precipitation of these elements with calcium in plants are rare. In this study, we compared morphologies, distributional patterns, and elemental compositions of crystals in tissues of four Acacia species grown in the field as well as in the glasshouse. A comparison was also made of field-grown plants and glasshouse-grown plants, and of phyllodes of different ages for each species. Crystals of various morphologies and distributional patterns were observed in the four Acacia species studied. Magnesium, strontium and barium were precipitated together with calcium, mainly in phyllodes of the four Acacia species, and sometimes in branchlets and primary roots. These elements were most likely precipitated in forms of oxalate and sulfate in various tissues, including epidermis, mesophyll, parenchyma, sclerenchyma (fibre cells), pith, pith ray and cortex. In most cases, precipitation of calcium, magnesium, strontium and barium was biologically induced, and elements precipitated differed between soil types, plant species, and tissues within an individual plant; the precipitation was also related to tissue age. Formation of crystals containing these elements might play a role in regulating and detoxifying these elements in plants, and protecting the plants against herbivory.

  3. Precipitation of Calcium, Magnesium, Strontium and Barium in Tissues of Four Acacia Species (Leguminosae: Mimosoideae)

    PubMed Central

    He, Honghua; Bleby, Timothy M.; Veneklaas, Erik J.; Lambers, Hans; Kuo, John

    2012-01-01

    Precipitation of calcium in plants is common. There are abundant studies on the uptake and content of magnesium, strontium and barium, which have similar chemical properties to calcium, in comparison with those of calcium in plants, but studies on co-precipitation of these elements with calcium in plants are rare. In this study, we compared morphologies, distributional patterns, and elemental compositions of crystals in tissues of four Acacia species grown in the field as well as in the glasshouse. A comparison was also made of field-grown plants and glasshouse-grown plants, and of phyllodes of different ages for each species. Crystals of various morphologies and distributional patterns were observed in the four Acacia species studied. Magnesium, strontium and barium were precipitated together with calcium, mainly in phyllodes of the four Acacia species, and sometimes in branchlets and primary roots. These elements were most likely precipitated in forms of oxalate and sulfate in various tissues, including epidermis, mesophyll, parenchyma, sclerenchyma (fibre cells), pith, pith ray and cortex. In most cases, precipitation of calcium, magnesium, strontium and barium was biologically induced, and elements precipitated differed between soil types, plant species, and tissues within an individual plant; the precipitation was also related to tissue age. Formation of crystals containing these elements might play a role in regulating and detoxifying these elements in plants, and protecting the plants against herbivory. PMID:22848528

  4. Sodium alginate and gum acacia hydrogels of ZnO nanoparticles show wound healing effect on fibroblast cells.

    PubMed

    Raguvaran, R; Manuja, Balvinder K; Chopra, Meenu; Thakur, Rajesh; Anand, Taruna; Kalia, Anu; Manuja, Anju

    2017-03-01

    An ideal biomaterial for wound dressing applications should possess antibacterial and anti-inflammatory properties without any toxicity to the host cells while providing the maximum healing activity. Zinc oxide nanoparticles (ZnONPs) possess antimicrobial activity and enhance wound healing, but the questions regarding their safety arise before application to the biological systems. We synthesized ZnONPs-loaded-sodium alginate-gum acacia hydrogels (SAGA-ZnONPs) by cross linking hydroxyl groups of the polymers sodium alginate and gum acacia with the aldehyde group of gluteradehyde. Here, we report the wound healing properties of sodium alginate/gum acacia/ZnONPs, circumventing the toxicity of ZnONPs simultaneously. We demonstrated the concentration-dependent zones of inhibition in treated cultures of Pseudomonas aerigunosa and Bacillus cereus and biocompatability on peripheral blood mononuclear/fibroblast cells. SAGA-ZnONPs hydrogels showed a healing effect at a low concentration of ZnONPs using sheep fibroblast cells. Our findings suggest that high concentrations of ZnONPs were toxic to cells but SAGA-ZnONPs hydrogels significantly reduced the toxicity and preserved the beneficial antibacterial and healing effect. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Influence of Acacia trees on soil nutrient levels in arid lands

    NASA Astrophysics Data System (ADS)

    De Boever, Maarten; Gabriels, Donald; Ouessar, Mohamed; Cornelis, Wim

    2014-05-01

    The potential of scattered trees as keystone structures in restoring degraded environments is gaining importance. Scattered trees have strong influence on their abiotic environment, mainly causing changes in microclimate, water budget and soil properties. They often function as 'nursing trees', facilitating the recruitment of other plants. Acacia raddiana is such a keystone species which persists on the edge of the Sahara desert. The study was conducted in a forest-steppe ecosystem in central Tunisia where several reforestation campaigns with Acacia took place. To indentify the impact of those trees on soil nutrients, changes in nutrient levels under scattered trees of three age stages were examined for the upper soil layer (0-10 cm) at five microsites with increasing distance from the trunk. In addition, changes in soil nutrient levels with depth underneath and outside the canopy were determined for the 0-30 cm soil layer. Higher concentrations of organic matter (OM) were found along the gradient from underneath to outside the canopy for large trees compared to medium and small trees, especially at microsites close to the trunk. Levels of soluble K, electrical conductivity (EC), available P, OM, total C and N decreased whereas pH and levels of soluble Mg increased with increasing distance from tree. Levels of soluble Ca and Na remained unchanged along the gradient. At the microsite closest to the trunk a significant decrease in levels of soluble K, EC, OM, available P, total C and N, while a significant increase in pH was found with increasing depth. The concentration of other nutrients remained unchanged or declined not differently underneath compared to outside the canopy with increasing depth. Differences in nutrient levels were largely driven by greater inputs of organic matter under trees. Hence, Acacia trees can affect the productivity and reproduction of understory species with the latter in term an important source of organic matter. This positive feedback

  6. Effect of Acacia Gum, NaCl, and Sucrose on Physical Properties of Lotus Stem Starch

    PubMed Central

    Gill, Balmeet Singh

    2014-01-01

    Consumer preferences in east Asian part of the world pave the way for consumption of lotus stem starch (LSS) in preparations such as breakfast meals, fast foods, and traditional confectioneries. The present study envisaged the investigation and optimization of additives, that is, acacia gum, sodium chloride (NaCl), and sucrose, on water absorption (WA), water absorption index (WAI), and water solubility index (WSI) of LSS employing response surface methodology (RSM). Acacia gum resulted in increased water uptake and swelling of starch; however, NaCl reduced the swelling power of starch by making water unavailable to starch and also due to starch-ion electrostatic interaction. Sucrose restricted the water absorption by binding free water and decreased amylose leaching by building bridges with starch chains and thus forming rigid structure. PMID:26904639

  7. The effect of saturated steam vapor temperature on heat consumption in the process of color modification of acacia wood

    NASA Astrophysics Data System (ADS)

    Dzurenda, Ladislav

    2017-09-01

    This paper presents the heat consumption on the process of colour modification of acacia timber with measures 30 x 55 x 500 mm in pressure autoclaves AZ 240 using saturated water steam with temperatures from t = 110 to 140 °C following the regimes of colour homogenisation of I., II. and III. degree. The dependance of the heat consumption normative QTFS on the temparature of saturated water steam in the process of colour homogenisation of acacia timber following these regimes describes the equation: QTFS = 1.1122.t -13.903 kWh.m-3.

  8. Operational disease screening program for resistance to wilt in Acacia koa in Hawaii

    Treesearch

    Nick Dudley; Robert James; Richard Sniezko; Phil Cannon; Aileen Yeh; Tyler Jones; Michael Kaufmann

    2012-01-01

    In Hawaii, koa (Acacia koa A. Gray) is a valuable tree species economically, ecologically, and culturally. With significant land use change and declines in sugarcane, pineapple, and cattle production, there is an opportunity and keen interest in utilizing native koa in reforestation and restoration efforts. However, moderate to high mortality rates...

  9. Mapping of invasive Acacia species in Brazilian Mussununga ecosystems using high- resolution IR remote sensing data acquired with an autonomous Unmanned Aerial System (UAS)

    NASA Astrophysics Data System (ADS)

    Lehmann, Jan Rudolf Karl; Zvara, Ondrej; Prinz, Torsten

    2015-04-01

    The biological invasion of Australian Acacia species in natural ecosystems outside Australia has often a negative impact on native and endemic plant species and the related biodiversity. In Brazil, the Atlantic rainforest of Bahia and Espirito Santo forms an associated type of ecosystem, the Mussununga. In our days this biologically diverse ecosystem is negatively affected by the invasion of Acacia mangium and Acacia auriculiformis, both introduced to Brazil by the agroforestry to increase the production of pulp and high grade woods. In order to detect the distribution of Acacia species and to monitor the expansion of this invasion the use of high-resolution imagery data acquired with an autonomous Unmanned Aerial System (UAS) proved to be a very promising approach. In this study, two types of datasets - CIR and RGB - were collected since both types provide different information. In case of CIR imagery attention was paid on spectral signatures related to plants, whereas in case of RGB imagery the focus was on surface characteristics. Orthophoto-mosaics and DSM/DTM for both dataset were extracted. RGB/IHS transformations of the imagery's colour space were utilized, as well as NDVIblue index in case of CIR imagery to discriminate plant associations. Next, two test areas were defined in order validate OBIA rule sets using eCognition software. In case of RGB dataset, a rule set based on elevation distinction between high vegetation (including Acacia) and low vegetation (including soils) was developed. High vegetation was classified using Nearest Neighbour algorithm while working with the CIR dataset. The IHS information was used to mask shadows, soils and low vegetation. Further Nearest Neighbour classification was used for distinction between Acacia and other high vegetation types. Finally an accuracy assessment was performed using a confusion matrix. One can state that the IHS information appeared to be helpful in Acacia detection while the surface elevation

  10. Stripping of Acacia koa bark by rats on Hawaii and Maui

    Treesearch

    Paul G. Scowcroft; Howard F. Sakai

    1984-01-01

    Koa (Acacia koa) is the most valuable native timber species in Hawaii. Bark stripping of young trees by rats, a common but unstudied phenomenon, may affect survival, growth, and quality of koa. Up to 54% of the trees sampled in 4- to 6-year-old stands in the Laupahoehoe and Waiakea areas on Hawaii were wounded by rats; only 5% of trees sampled in a l-year-old stand on...

  11. Fine Structure of Bacteroids in Root Nodules of Vigna sinensis, Acacia longifolia, Viminaria juncea, and Lupinus angustifolius

    PubMed Central

    Dart, P. J.; Mercer, F. V.

    1966-01-01

    Dart, P. J. (University of Sydney, Sydney, Australia), and F. V. Mercer. Fine structure of bacteroids in root nodules of Vigna sinensis, Acacia longifolia, Viminaria juncea, and Lupinus angustifolius. J. Bacteriol. 91:1314–1319.—In nodules of Vigna sinensis, Acacia longifolia, and Viminaria juncea, membrane envelopes enclose groups of bacteroids. The bacteroids often contain inclusion granules and electron-dense bodies, expand little during development, and retain their rod form with a compact, central nucleoid area. The membrane envelope may persist around bacteroids after host cytoplasm breakdown. In nodules of Lupinus angustifolius, the membrane envelopes enclose only one or two bacteroids, which expand noticeably during development and change from their initial rod structure. Images PMID:5929757

  12. Early field performance of Acacia koa seedlings grown under subirrigation and overhead irrigation

    Treesearch

    Anthony S. Davis; Jeremiah R. Pinto; Douglass F. Jacobs

    2011-01-01

    Koa (Acacia koa A. Gray [Fabaceae]) seedlings were grown with subirrigation and overhead irrigation systems in an effort to characterize post-nursery field performance. One year following outplanting, we found no differences in seedling height or survival, but root-collar diameter was significantly larger for subirrigated seedlings. This indicates that koa seedlings,...

  13. Ecophysiological and foliar nitrogen concentration responses of understorey Acacia spp. and Eucalyptus sp. to prescribed burning.

    PubMed

    Ma, Ling; Rao, Xingquan; Lu, Ping; Bai, Shahla Hosseini; Xu, Zhihong; Chen, Xiaoyang; Blumfield, Timothy; Xie, Jun

    2015-07-01

    Eucalyptus spp. is a dominant tree genus in Australia and most Eucalyptus spp. are canopy dominant species. In Australian natural forests, Eucalyptus spp. commonly are associated with understorey legumes which play a crucial role for ecological restoration owing to their nitrogen (N) fixing ability for replenishing the soil N lost after frequent prescribed burning. This study aimed to explore to what extent physiological responses of these species differ 7 and 12 years after last fire. Two most common understorey Acacia spp., Acacia leiocalyx and A. disparrima, as well as one non-leguminous Eucalyptus resinifera, were studied due to their dominance in the forest. Both A. leiocalyx and A. disparrima showed higher carbon (C) assimilation capacity, maximum photosynthetic capacity, and moderate foliar C/N ratio compared with E. resinifera. A. leiocalyx showed various advantages compared to A. disparrima such as higher photosynthetic capacity, adaptation to wider light range and higher foliar total N (TNmass). A. leiocalyx also relied on N2-fixing ability for longer time compared to A. disparrima. The results suggested that the two Acacia spp. were more beneficial to C and N cycles for the post burning ecosystem than the non-N2-fixing species E. resinifera. A. leiocalyx had greater contribution to complementing soil N cycle long after burning compared to A. disparrima.

  14. Polyploidy can Confer Superiority to West African Acacia senegal (L.) Willd. Trees

    PubMed Central

    Diallo, Adja M.; Nielsen, Lene R.; Kjær, Erik D.; Petersen, Karen K.; Ræbild, Anders

    2016-01-01

    Polyploidy is a common phenomenon in the evolution of angiosperms. It has been suggested that polyploids manage harsh environments better than their diploid relatives but empirical data supporting this hypothesis are scarce, especially for trees. Using microsatellite markers and flow cytometry, we examine the frequency of polyploids and diploids in a progeny trial testing four different populations of Acacia senegal, a species native to sub-Saharan regions of Africa. We compare growth between cytotypes and test whether polyploid seedlings grow better than diploids. Our results show that polyploids coexist with diploids in highly variable proportions among populations in Senegal. Acacia senegal genotypes were predominantly diploid and tetraploid, but triploid, pentaploid, hexaploid, and octaploid forms were also found. We find that polyploids show faster growth than diploids under our test conditions: in an 18 years old field trial, polyploid superiority was estimated to be 17% in trunk diameter and 9% in height while in a growth chamber experiment, polyploids grew 28% taller, but only after being exposed to drought stress. The results suggest that polyploid A. senegal can have an adaptive advantage in some regions of Africa. PMID:27379120

  15. Polyploidy can Confer Superiority to West African Acacia senegal (L.) Willd. Trees.

    PubMed

    Diallo, Adja M; Nielsen, Lene R; Kjær, Erik D; Petersen, Karen K; Ræbild, Anders

    2016-01-01

    Polyploidy is a common phenomenon in the evolution of angiosperms. It has been suggested that polyploids manage harsh environments better than their diploid relatives but empirical data supporting this hypothesis are scarce, especially for trees. Using microsatellite markers and flow cytometry, we examine the frequency of polyploids and diploids in a progeny trial testing four different populations of Acacia senegal, a species native to sub-Saharan regions of Africa. We compare growth between cytotypes and test whether polyploid seedlings grow better than diploids. Our results show that polyploids coexist with diploids in highly variable proportions among populations in Senegal. Acacia senegal genotypes were predominantly diploid and tetraploid, but triploid, pentaploid, hexaploid, and octaploid forms were also found. We find that polyploids show faster growth than diploids under our test conditions: in an 18 years old field trial, polyploid superiority was estimated to be 17% in trunk diameter and 9% in height while in a growth chamber experiment, polyploids grew 28% taller, but only after being exposed to drought stress. The results suggest that polyploid A. senegal can have an adaptive advantage in some regions of Africa.

  16. Impact of the energy crop Jatropha curcas L. on the composition of rhizobial populations nodulating cowpea (Vigna unguiculata L.) and acacia (Acacia seyal L.).

    PubMed

    Dieng, Amadou; Duponnois, Robin; Floury, Antoine; Laguerre, Gisèle; Ndoye, Ibrahima; Baudoin, Ezékiel

    2015-03-01

    Jatropha curcas, a Euphorbiaceae species that produces many toxicants, is increasingly planted as an agrofuel plant in Senegal. The purpose of this study was to determine whether soil priming induced by J. curcas monoculture could alter the rhizobial populations that nodulate cowpea and acacia, two locally widespread legumes. Soil samples were transferred into a greenhouse from three fields previously cultivated with Jatropha for 1, 2, and 15 years, and the two trap legumes were grown in them. Control soil samples were also taken from adjacent Jatropha-fallow plots. Both legumes tended to develop fewer but larger nodules when grown in Jatropha soils. Nearly all the nifH sequences amplified from nodule DNA were affiliated to the Bradyrhizobium genus. Only sequences from Acacia seyal nodules grown in the most recent Jatropha plantation were related to the Mesorhizobium genus, which was much a more conventional finding on A. seyal than the unexpected Bradyrhizobium genus. Apart from this particular case, only minor differences were found in the respective compositions of Jatropha soil versus control soil rhizobial populations. Lastly, the structure of these rhizobial populations was systematically imbalanced owing to the overwhelming dominance of a very small number of nifH genotypes, some of which were identical across soil types or even sites. Despite these weak and sparse effects on rhizobial diversity, future investigations should focus on the characterization of the nitrogen-fixing abilities of the predominant rhizobial strains. Copyright © 2014 Elsevier GmbH. All rights reserved.

  17. A green approach to prepare silver nanoparticles loaded gum acacia/poly(acrylate) hydrogels.

    PubMed

    Bajpai, S K; Kumari, Mamta

    2015-09-01

    In this work, gum acacia (GA)/poly(sodium acrylate) semi-interpenetrating polymer networks (Semi-IPN) have been fabricated via free radical initiated aqueous polymerization of monomer sodium acrylate (SA) in the presence of dissolved Gum acacia (GA), using N,N'-methylenebisacrylamide (MB) as cross-linker and potassium persulphate (KPS) as initiator. The semi-IPNs, synthesized, were characterized by various techniques such as X-ray diffraction (XRD), thermo gravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The dynamic water uptake behavior of semi-IPNs was investigated and the data were interpreted by various kinetic models. The equilibrium swelling data were used to evaluate various network parameters. The semi-IPNs were used as template for the in situ preparation of silver nanoparticles using extract of Syzygium aromaticum (clove). The formation of silver nanoparticles was confirmed by surface plasmon resonance (SPR), XRD and transmission electron microscopy (TEM). Finally, the antibacterial activity of GA/poly(SA)/silver nanocomposites was tested against E. coli. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Stable isotope ratios and reforestation potential in Acacia koa populations on Hawai'i

    Treesearch

    Shaneka Lawson; Carrie Pike

    2017-01-01

    Stable carbon and nitrogen isotopes can be influenced by a multitude of factors including elevation, precipitation rate, season, and temperature. This work examined variability in foliar stable carbon (δ13C) and nitrogen (δ15N) isotope ratios of koa (Acacia koa) across 17 sites on Hawai'i Island, delineated by elevation and precipitation...

  19. Aboveground biomass equations for 7-year-old Acacia mangium Willd in Botucatu, Brazil

    Treesearch

    Ricardo A. A. Veiga; Maria A. M. Brasil; Carlos M. Carvalho

    2000-01-01

    The biomass of steins, leaves, and branches was determined for 152 sample trees of Acacia mangium Willd were in a 7-year-old experimental plantation in Botucatu, Sao Paulo State, Brazil. After felling, dimensional measurements were taken from each tree. Cross sections were collected in 125 sample trees at ground level (0 percent), 25 percent, 50...

  20. UAS-NAS Stakeholder Feedback Report

    NASA Technical Reports Server (NTRS)

    Randall, Debra; Murphy, Jim; Grindle, Laurie

    2016-01-01

    The need to fly UAS in the NAS to perform missions of vital importance to national security and defense, emergency management, science, and to enable commercial applications has been continually increasing over the past few years. To address this need, the NASA Aeronautics Research Mission Directorate (ARMD) Integrated Aviation Systems Program (IASP) formulated and funded the Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project (hereafter referred to as UAS-NAS Project) from 2011 to 2016. The UAS-NAS Project identified the following need statement: The UAS community needs routine access to the global airspace for all classes of UAS. The Project identified the following goal: To provide research findings to reduce technical barriers associated with integrating UAS into the NAS utilizing integrated system level tests in a relevant environment. This report provides a summary of the collaborations between the UAS-NAS Project and its primary stakeholders and how the Project applied and incorporated the feedback.

  1. Evaluation of Cytotoxicity and Genotoxicity of Acacia aroma Leaf Extracts

    PubMed Central

    Mattana, C. M.; Cangiano, M. A.; Alcaráz, L. E.; Sosa, A.; Escobar, F.; Sabini, C.; Sabini, L.; Laciar, A. L.

    2014-01-01

    Acacia aroma, native plant from San Luis, Argentina, is commonly used as antiseptic and for healing of wounds. The present study was conducted to investigate the in vitro cytotoxicity and genotoxicity of hot aqueous extract (HAE) and ethanolic extract (EE) of A. aroma. The cytotoxic activity was assayed by neutral red uptake assay on Vero cell. Cell treatment with a range from 100 to 5000 μg/mL of HAE and EE showed that 500 μg/mL and 100 μg/mL were the maximum noncytotoxic concentrations, respectively. The CC50 was 658 μg/mL for EE and 1020 μg/mL for HAE. The genotoxicity was tested by the single-cell gel electrophoresis comet assay. The results obtained in the evaluation of DNA cellular damage exposed to varied concentrations of the HAE showed no significant genotoxic effect at range of 1–20 mg/mL. The EE at 20 mg/mL showed moderate genotoxic effect related to the increase of the DNA percentage contained in tail of the comet; DNA was classified in category 2. At concentrations below 5 mg/mL, the results of cytotoxicity and genotoxicity of aqueous and ethanolic extracts of Acacia aroma guarantee the safety at cell and genomic level. However further studies are needed for longer periods including animal models to confirm the findings. PMID:25530999

  2. [Growth effect of eucalyptus-acacia mixed plantation in South China].

    PubMed

    Yang, Zeng-Jiang; Xu, Da-Ping; Chen, Wen-Ping; Huang, Lie-Jian; Li, Shang-Jun; Chen, Yuan

    2009-10-01

    Eucalyptus U6 and Acacia crassicarpa were mixed planted with different ratios and modes to investigate the growth parameters of the two tree species. In the 2-3 years old mixed plantation, the wind-throw of A. crassicarpa decreased markedly with increasing ratio of Eucalyptus U6, the decrement being 26.14% when the Eucalyptus U6/A. crassicarpa ratio was 3 : 1, but the survival rates of Eucalyptus U6 and A. crassicarpa had no significant difference under different planting modes. Mixed planting retarded the A. crassicarpa growth to some extent, with the DBH being 90% of that in pure A. crassicarpa stand. The mixed planting had little effects on the height growth of Eucalyptus U6, but promoted its DBH growth markedly, and the beneficial effect increased with increasing ratio of A. crassicarpa. In the 6 years old 1 : 1 Eucalyptus U6/A. crassicarpa plantation, the Eucalyptus U6 individuals with DBH > 15 cm occupied 32.1%; while in pure Eucalyptus U6 stand, they only accounted for 5.83%. Mixed planting with 2 : 1 Eucalyptus U6/A. crassicarpa could obtain a maximum total biomass of 198.8 m3 x hm(-2), which was 118.8% of the total biomass in pure Eucalyptus U6 stand, or 169.9% of that in pure A. crassicarpa stand. Mixture of Eucalyptus with Acacia would be a good choice to produce Eucalyptus trees with larger DBH.

  3. Competition for light and light use efficiency for Acacia mangium and Eucalyptus grandis trees in mono-specific and mixed-species plantations in Brazil

    NASA Astrophysics Data System (ADS)

    Le Maire, G.; Nouvellon, Y.; Gonçalves, J.; Bouillet, J.; Laclau, J.

    2010-12-01

    Mixed plantations with N-fixing species might be an attractive option for limiting the use of fertilizer in highly productive Eucalyptus plantations. A randomized block design was set up in southern Brazil, including a replacement series and an additive series design, as well as a nitrogen fertilization treatment, and conducted during a full 6 years rotation. The gradient of competition between Eucalyptus and Acacia in this design resulted in very different conditions of growth of Acacia, from totally dominated up to dominant canopies. We used the MAESTRA model to estimate the amount of absorbed photosynthetically active radiation (APAR) at tree level. This model requires the description of the scene and distinct structural variables of the two species, and their evolution with time. The competition for light is analysed by comparing the inter-specific values of APAR during a period of 2 years at the end of the rotation. APAR is further compared to the measured increment in stem wood biomass of the tree, and their ratio is an estimation of the light use efficiency for stemwood production at tree-scale. Variability of these LUE are analysed in respect to the species, the size of the tree, and at plot scale (competition level). Stemwood production was 3400, 3900 and 2400 gDM/m2 while APAR was 1640, 2280 and 2900 MJ/y for the pure Eucalyptus, pure Acacia and 50/50 mixed plantation, respectively, for an average LAI of 3.7, 3.3 and 4.5, respectively. Individual LUE for stemwood was estimated at an average value of 1.72 and 1.41 gDM/MJ/tree for Eucalyptus and Acacia, respectively, and at 0.92 and 0.40 gDM/MJ/tree when they were planted in mixed 50/50 plantations. LUE was highly dependant on tree size for both species. At the plot scale, LUE for stemwood were 2.1 gDM/MJ and 1.75 for Eucalyptus and Acacias, respectively, and 0.85 for the mixed 50/50 plantation. These results suggest that the mixed 50/50 plantation, which absorbed a higher amount of light, produce less

  4. Nursery response of Acacia koa seedlings to container size, irrigation method, and fertilization rate

    Treesearch

    R. Kasten Dumroese; Anthony S. Davis; Douglass F. Jacobs

    2011-01-01

    Planting koa (Acacia koa A. Gray) in Hawai'i, USA aids in restoration of disturbed sites essential to conservation of endemic species. Survival and growth of planted seedlings under vegetative competition typically increases with initial plant size. Increasing container size and fertilizer rate may produce larger seedlings, but high fertilization can lead to...

  5. Cadmium tolerance and phytoremediation potential of acacia (Acacia nilotica L.) under salinity stress.

    PubMed

    Shabir, Rahat; Abbas, Ghulam; Saqib, Muhammad; Shahid, Muhammad; Shah, Ghulam Mustafa; Akram, Muhammad; Niazi, Nabeel Khan; Naeem, Muhammad Asif; Hussain, Munawar; Ashraf, Farah

    2018-06-07

    In this study, we explored the effect of salinity on cadmium (Cd) tolerance and phytoremediation potential of Acacia nilotica. Two-month-old uniform plants of A. nilotica were grown in pots contaminated with various levels of Cd (0, 5, 10, and 15 mg kg -1 ), NaCl (0%, 0.5%, 1.0% (hereafter referred as salinity), and all possible combinations of Cd + salinity for a period of six months. Results showed that shoot and root growth, biomass, tissue water content and chlorophyll (chl a, chl b, and total chl a+b) contents decreased more in response to salinity and combination of Cd + salinity compared to Cd alone. Shoot and root K concentrations significantly decreased with increasing soil Cd levels, whereas Na and Cl concentrations were not affected significantly. Shoot and root Cd concentrations, bioconcentration factor (BCF) and translocation factor (TF) increased with increasing soil Cd and Cd + salinity levels. At low level of salinity (0.5%), shoot and root Cd uptake enhanced, while it decreased at high level of salinity (1.0%). Due to Cd tolerance, high shoot biomass and shoot Cd uptake, this tree species has some potential for phytoremediation of Cd from the metal contaminated saline and nonsaline soils.

  6. Chemical composition and nutritional evaluation of the seeds of Acacia tortilis (Forssk.) Hayne ssp. raddiana.

    PubMed

    Embaby, Hassan E; Rayan, Ahmed M

    2016-06-01

    Chemical composition and nutritional evaluation as well as physicochemical and functional properties of seed flour of Acacia tortilis (Forssk.) Hayne ssp. raddiana were studied. The results indicated that seeds contained 5.30% moisture, 3.99% ash, 9.19% fat, 14.31% fiber, 27.21% protein and 45.30% carbohydrates. Potassium was the predominant element followed by calcium and then phosphorous. Phytic acid, tannins and trypsin inhibitor as antinutrients were detected. The amino acid profile compared well with FAO/WHO recommended pattern except for cystine/methionine, isoleucine, tyrosine/phenylalanine, lysine and threonine. Also, the first limiting amino acid was lysine. Fatty acid composition showed that linoleic acid was the major fatty acid, followed by palmitic, stearic, oleic and arachidic acids. The seed oil showed absorbance in the ultraviolet ranges, thus it can be used as a broad spectrum UV protectant. For physicochemical and functional properties, acacia seeds flour had excellent water holding index, swelling index, foaming capacity and foam stability. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Modulatory role of Acacia honey from north-west Nigeria on sodium arsenite-induced clastogenicity and oxidative stress in male Wistar rats.

    PubMed

    Muhammad, Aliyu; Odunola, Oyeronke A; Gbadegesin, Michael A; Adegoke, Ayodeji M; Olugbami, J Olorunjuwon; Uche, Ndidi S

    2015-01-01

    Effect of Acacia honey from north-west Nigeria on sodium arsenite-induced oxidative damage and clastogenicity in male Wistar rats was investigated. Animals were divided into four groups and were treated daily via oral gavage for one week before they were sacrificed. Brain, liver and blood serum were collected for antioxidant and protein assays. Clastogenicity, in vitro antioxidant activity, vitamins and minerals were also evaluated. From the results, co-administration of Acacia honey with sodium arsenite on the animals increased (P < 0.05) glutathione peroxidase, superoxide dismutase and catalase activities with concomitant decrease in malondialdehyde levels and anti-clastogenic effects relative to the group treated with sodium arsenite only. The honey possesses reducing power, high hydrogen peroxide scavenging activity, good amount of vitamins (A, C and E), flavonoids (5.08 ± 0.92 mg QE/100 g) and phenolics (5.40 ± 0.69 mg GAE/100 g). The minerals present include zinc, iron, sodium, magnesium, potassium and calcium. In conclusion, Acacia honey from Nigeria may mitigate oxidative stress and clastogenicity.

  8. Effects of phosphorus fertilization, seed source, and soil type on growth of Acacia koa

    Treesearch

    P. G. Scowcroft; J. A. Silva

    2005-01-01

    The endemic tree Acacia koa is used to reforest abandoned agricuItural lands in Hawaii. Growth may be constrained by soil infertility and toxic concentrations of aluminum (AI) and manganese (Mn) in acidic Oxisols and Ultisols, The effects of phosphorus (P) fertilization at time of planting, soil type, and seed source on koa growth were studied for three years....

  9. Copper and lead bioaccumulation by Acacia retinoides and Eucalyptus torquata in sites contaminated as a consequence of extensive ancient mining activities in Cyprus.

    PubMed

    Pyatt, F B

    2001-09-01

    Aspects of the industrial archaeology of the northwestern part of the island of Cyprus are outlined. Wastes resultant from copper mining activities of approximately two millennia ago continue to exert an important influence on organisms. Detailed chemical analysis of two tree species growing on archaeologically important metalliferous spoil tips has indicated their ability to bioaccumulate heavy metals and sulfur primarily from the substratum; the bioaccumulation and biomagnification of lead and sulfur are particularly marked in both Acacia and Eucalyptus. The concentrations of elements in different parts of the two tree species are discussed and partitioning is noted together with the fact that while the pod of Acacia and the fruit capsule of Eucalyptus may have an enhanced metal loading, the values in the seeds are much reduced; the importance of this is discussed. The seeds of Acacia differ chemically from those of Eucalyptus. The importance of these plants as biomonitors of environmental quality is noted. Copyright 2001 Academic Press.

  10. Impact of Hurricane Iniki on native Hawaiian Acacia koa forests: damage and two-year recovery

    Treesearch

    Robin A. Harrington; James H. Fownes; Paul G. Scowcroft; Cheryl S. Vann

    1997-01-01

    Damage to Hawaiian Acacia koa forest by Hurricane Iniki was assessed by comparison with our previous measures of stand structure and leaf area index (LAI) at sites along a precipitation/elevation gradient on western Kauai. Reductions in LAI ranged from 29 to 80% and were correlated with pre-hurricane LAI and canopy height. The canopy damage...

  11. Stocktype and grass suppression accelerate the restoration trajectory of Acacia koa in Hawaiian montane ecosystems

    Treesearch

    Jeremy Pinto; Anthony S. Davis; James J. K. Leary; Matthew M. Aghai

    2015-01-01

    Restoring degraded mesic-montane forests represents a major challenge in maintaining functioning ecosystems throughout the tropics. A key example of this lies in Hawai‘i, where restoring native koa (Acacia koa, A. Gray) forests are a top conservation and forestry priority because of the critical habitat and high-value timber products that they provide. Efforts...

  12. Excessive sulphur accumulation and ionic storage behaviour identified in species of Acacia (Leguminosae: Mimosoideae)

    PubMed Central

    Reid, N.; Robson, T. C.; Radcliffe, B.; Verrall, M.

    2016-01-01

    Background and Aims Thiophores, which are typically desert gypsophytes, accumulate high (2–6 % S dry weight) sulphur concentrations and may possess unique tolerance to environmental stress factors, e.g. sulphate/metal toxicity, drought and salinity. Little is known of the prevalence of the behaviour or the associated physiological aspects. The aim of this study was to (a) determine the prevalence of thiophore behaviour in a group of Australian xerophytes; (b) identify elemental uptake/storage characteristics of these thiophores; and (c) determine whether the behaviour is constitutive or environmental. Methods The elemental composition of soils and the foliage of 11 species (seven genera) at a site in the Tanami Desert (NT, Australia) was compared and 13 additional Acacia species from other locations were examined for elevated calcium and sulphur concentrations and calcium–sulphur mineralization, thought to be particular to thiophores. Key Results Acacia bivenosa DC. and 11 closely related species were identified as thiophores that can accumulate high levels of sulphur (up to 3·2 %) and calcium (up to 6.8 %), but no thiophores were identified in other genera occupying the same habitat. This behaviour was observed in several populations from diverse habitats, from samples collected over three decades. It was also observed that these thiophores featured gypsum (CaSO4·2H2O) crystal druses that completely filled cells and vascular systems in their dried phyllode tissues. Conclusions The thiophores studied exhibit a tight coupling between sulphur and calcium uptake and storage, and apparently store these elements as inorganic salts within the cells of their foliage. Thiophore behaviour is a constitutive trait shared by closely related Acacia but is not highly prevalent within, nor exclusive to, xerophytes. Several of the newly identified thiophores occupy coastal or riparian habitats, suggesting that the evolutionary and ecophysiological explanations for this trait

  13. Excessive sulphur accumulation and ionic storage behaviour identified in species of Acacia (Leguminosae: Mimosoideae).

    PubMed

    Reid, N; Robson, T C; Radcliffe, B; Verrall, M

    2016-04-01

    Thiophores, which are typically desert gypsophytes, accumulate high (2-6 % S dry weight) sulphur concentrations and may possess unique tolerance to environmental stress factors, e.g. sulphate/metal toxicity, drought and salinity. Little is known of the prevalence of the behaviour or the associated physiological aspects. The aim of this study was to (a) determine the prevalence of thiophore behaviour in a group of Australian xerophytes; (b) identify elemental uptake/storage characteristics of these thiophores; and (c) determine whether the behaviour is constitutive or environmental. The elemental composition of soils and the foliage of 11 species (seven genera) at a site in the Tanami Desert (NT, Australia) was compared and 13 additional Acacia species from other locations were examined for elevated calcium and sulphur concentrations and calcium-sulphur mineralization, thought to be particular to thiophores. Acacia bivenosa DC. and 11 closely related species were identified as thiophores that can accumulate high levels of sulphur (up to 3·2 %) and calcium (up to 6.8 %), but no thiophores were identified in other genera occupying the same habitat. This behaviour was observed in several populations from diverse habitats, from samples collected over three decades. It was also observed that these thiophores featured gypsum (CaSO4·2H2O) crystal druses that completely filled cells and vascular systems in their dried phyllode tissues. The thiophores studied exhibit a tight coupling between sulphur and calcium uptake and storage, and apparently store these elements as inorganic salts within the cells of their foliage. Thiophore behaviour is a constitutive trait shared by closely related Acacia but is not highly prevalent within, nor exclusive to, xerophytes. Several of the newly identified thiophores occupy coastal or riparian habitats, suggesting that the evolutionary and ecophysiological explanations for this trait do not lie solely in adaptation to arid conditions or

  14. Colorimetric Detection Based on Localised Surface Plasmon Resonance Optical Characteristics for the Detection of Hydrogen Peroxide Using Acacia Gum–Stabilised Silver Nanoparticles

    PubMed Central

    Alzahrani, Eman

    2017-01-01

    The use of nanoparticles in sensing is attracting the interest of many researchers. The aim of this work was to fabricate Acacia gum–stabilised silver nanoparticles (SNPs) using green chemistry to use them as a highly sensitive and cost-effective localised surface plasmon resonance (LSPR) colorimeter sensor for the determination of reactive oxygen species, such as hydrogen peroxide (H2O2). Silver nanoparticles were fabricated by the reduction of an inorganic precursor silver nitrate solution (AgNO3) using white sugar as the reducing reagent and Acacia gum as the stabilising reagent and a sonication bath to form uniform silver nanoparticles. The fabricated nanoparticles were characterised by visual observation, ultraviolet-visible (UV-Vis) spectrophotometry, transmission electron microscopy (TEM) analysis, energy-dispersive X-ray spectroscopy (EDAX), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR). The TEM micrographs of the synthesised nanoparticles showed the presence of spherical nanoparticles with sizes of approximately 10 nm. The EDAX spectrum result confirmed the presence of silver (58%), carbon (30%), and oxygen (12%). Plasmon colorimetric sensing of H2O2 solution was investigated by introducing H2O2 solution into Acacia gum–capped SNP dispersion, and the change in the LSPR band in the UV-Vis region of spectra was monitored. In this study, it was found that the yellow colour of Acacia gum–stabilised SNPs gradually changed to transparent, and moreover, a remarkable change in the LSPR absorbance strength was observed. The calibration curve was linear over 0.1–0.00001 M H2O2, with a correlation estimation (R2) of .953. This was due to the aggregation of SNPs following introduction of the H2O2 solution. Furthermore, the fabricated SNPs were successfully used to detect H2O2 solution in a liquid milk sample, thereby demonstrating the ability of the fabricated SNPs to detect H2O2 solution in liquid milk samples. This

  15. Characterization and emulsifying properties of β-lactoglobulin-gum Acacia Seyal conjugates prepared via the Maillard reaction.

    PubMed

    Bi, Binwei; Yang, Hao; Fang, Yapeng; Nishinari, Katsuyoshi; Phillips, Glyn O

    2017-01-01

    Gum Acacia Seyal (ASY) is less valued than is gum Acacia Senegal, due to its poor emulsifying ability. The present study investigated the Maillard reaction between ASY and β-lactoglobulin (BLG) and its impact on the emulsifying properties of ASY. The reaction products of BLG/ASY mixture (r=1/4), prepared by dry-heating at 60°C and a relative humidity of 79%, as a function of incubation time, were characterized by SDS-PAGE, GPC-MALLS and DSC. The results showed that 12-24h of dry-heating under the given conditions was sufficient for conjugation, meanwhile avoiding the formation of deeply coloured and insoluble melanoidins. More than 64% of the protein was incorporated into ASY, resulting in a two-fold increase in arabinogalactan-protein (AGP) content and 3.5 times increase in weight-average molecular mass of ASY. The conjugation with BLG markedly improved the stability of ASY-stabilized emulsions and their resistance against severe conditions, such as low pH and high saline conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Understory structure in a 23-year-old Acacia koa forest and 2-year growth responses to silvicultural treatments

    Treesearch

    Paul G. Scowcroft; Janis E. Haraguchi; David M. Fujii

    2008-01-01

    Restoration of degraded Acacia koa forests in Hawaii often involves mechanical scarification to stimulate germination of seed buried in the soil and to suppress vegetation that competes with shade intolerant A. koa. Resulting even-age stands are gradually colonized by other plant species, but understory...

  17. Behavioural abnormalities of the hyposulphataemic Nas1 knock-out mouse.

    PubMed

    Dawson, Paul Anthony; Steane, Sarah Elizabeth; Markovich, Daniel

    2004-10-05

    We recently generated a sodium sulphate cotransporter knock-out mouse (Nas1-/-) which has increased urinary sulphate excretion and hyposulphataemia. To examine the consequences of disturbed sulphate homeostasis in the modulation of mouse behavioural characteristics, Nas1-/- mice were compared with Nas1+/- and Nas1+/+ littermates in a series of behavioural tests. The Nas1-/- mice displayed significantly (P < 0.001) decreased marble burying behaviour (4.33 +/- 0.82 buried) when compared to Nas1+/+ (7.86 +/- 0.44) and Nas1+/- (8.40 +/- 0.37) animals, suggesting that Nas1-/- mice may have decreased object-induced anxiety. The Nas1-/- mice also displayed decreased locomotor activity by moving less distance (1.53 +/- 0.27 m, P < 0.05) in an open-field test when compared to Nas1+/+ (2.31 +/- 0.24 m) and Nas1+/- (2.15 +/- 0.19 m) mice. The three genotypes displayed similar spatiotemporal and ethological behaviours in the elevated-plus maze and open-field test, with the exception of a decreased defecation frequency by the Nas1-/- mice (40% reduction, P < 0.01). There were no significant differences between Nas1-/- and Nas1+/+ mice in a rotarod performance test of motor coordination and in the forced swim test assessing (anti-)depressant-like behaviours. This is the first study to demonstrate behavioural abnormalities in the hyposulphataemic Nas1-/- mice.

  18. Acacia mangium: Growing and utilization. MPTS monograph series No. 3

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

    Awang, K.; Taylor, D.

    With deforestation in the Asia-Pacific region progressing at the rate of 4.4 million ha per year, many countries have adopted plantation forestry using fast-growing species as a way to sustain the commercial supply of tree products and reduce pressure on natural forests. Acacia mangium (A. mangium) is playing a large role in this development, especially in Indonesia and Malaysia, due to its versatility and its ability to recapture grasslands dominated by the noxious weed, Imperata cylindrica. This monograph consolidates information on A. mangium from published literature, unpublished reports and studies, and observations from those familiar with the species. Priorities formore » future research are included in each chapter and in the final summary.« less

  19. Host-driven diversification of gall-inducing Acacia thrips and the aridification of Australia

    PubMed Central

    McLeish, Michael J; Chapman, Thomas W; Schwarz, Michael P

    2007-01-01

    Background Insects that feed on plants contribute greatly to the generation of biodiversity. Hypotheses explaining rate increases in phytophagous insect diversification and mechanisms driving speciation in such specialists remain vexing despite considerable attention. The proliferation of plant-feeding insects and their hosts are expected to broadly parallel one another where climate change over geological timescales imposes consequences for the diversification of flora and fauna via habitat modification. This work uses a phylogenetic approach to investigate the premise that the aridification of Australia, and subsequent expansion and modification of arid-adapted host flora, has implications for the diversification of insects that specialise on them. Results Likelihood ratio tests indicated the possibility of hard molecular polytomies within two co-radiating gall-inducing species complexes specialising on the same set of host species. Significant tree asymmetry is indicated at a branch adjacent to an inferred transition to a Plurinerves ancestral host species. Lineage by time diversification plots indicate gall-thrips that specialise on Plurinerves hosts differentially experienced an explosive period of speciation contemporaneous with climatic cycling during the Quaternary period. Chronological analyses indicated that the approximate age of origin of gall-inducing thrips on Acacia might be as recent as 10 million years ago during the Miocene, as truly arid landscapes first developed in Australia. Conclusion Host-plant diversification and spatial heterogeneity of hosts have increased the potential for specialisation, resource partitioning, and unoccupied ecological niche availability for gall-thrips on Australian Acacia. PMID:17257412

  20. Ectomycorrhizal Communities Associated with the Legume Acacia spirorbis Growing on Contrasted Edaphic Constraints in New Caledonia.

    PubMed

    Houles, Anne; Vincent, Bryan; David, Magali; Ducousso, Marc; Galiana, Antoine; Juillot, Farid; Hannibal, Laure; Carriconde, Fabian; Fritsch, Emmanuel; Jourand, Philippe

    2018-05-01

    This study aims to characterize the ectomycorrhizal (ECM) communities associated with Acacia spirorbis, a legume tree widely spread in New Caledonia that spontaneously grows on contrasted edaphic constraints, i.e. calcareous, ferralitic and volcano-sedimentary soils. Soil geochemical parameters and diversity of ECM communities were assessed in 12 sites representative of the three mains categories of soils. The ectomycorrhizal status of Acacia spirorbis was confirmed in all studied soils, with a fungal community dominated at 92% by Basidiomycota, mostly represented by/tomentella-thelephora (27.6%), /boletus (15.8%), /sebacina (10.5%), /russula-lactarius (10.5%) and /pisolithus-scleroderma (7.9%) lineages. The diversity and the proportion of the ECM lineages were similar for the ferralitic and volcano-sedimentary soils but significantly different for the calcareous soils. These differences in the distribution of the ECM communities were statistically correlated with pH, Ca, P and Al in the calcareous soils and with Co in the ferralitic soils. Altogether, these data suggest a high capacity of A. spirorbis to form ECM symbioses with a large spectrum of fungi regardless the soil categories with contrasted edaphic parameters.

  1. The acacia ants revisited: convergent evolution and biogeographic context in an iconic ant/plant mutualism

    PubMed Central

    2017-01-01

    Phylogenetic and biogeographic analyses can enhance our understanding of multispecies interactions by placing the origin and evolution of such interactions in a temporal and geographical context. We use a phylogenomic approach—ultraconserved element sequence capture—to investigate the evolutionary history of an iconic multispecies mutualism: Neotropical acacia ants (Pseudomyrmex ferrugineus group) and their associated Vachellia hostplants. In this system, the ants receive shelter and food from the host plant, and they aggressively defend the plant against herbivores and competing plants. We confirm the existence of two separate lineages of obligate acacia ants that convergently occupied Vachellia and evolved plant-protecting behaviour, from timid ancestors inhabiting dead twigs in rainforest. The more diverse of the two clades is inferred to have arisen in the Late Miocene in northern Mesoamerica, and subsequently expanded its range throughout much of Central America. The other lineage is estimated to have originated in southern Mesoamerica about 3 Myr later, apparently piggy-backing on the pre-existing mutualism. Initiation of the Pseudomyrmex/Vachellia interaction involved a shift in the ants from closed to open habitats, into an environment with more intense plant herbivory. Comparative studies of the two lineages of mutualists should provide insight into the essential features binding this mutualism. PMID:28298350

  2. Size variation of Acacia caven (leguminosae) pods along a climatic gradient in Chile

    NASA Astrophysics Data System (ADS)

    Gutiérrez, J. R.; Armesto, J. J.

    1981-06-01

    A southward tendency of increment in pod-length is shown for 11 populations of Acacia caven (Mol.) Hook et Arn. localized along a climatic gradient of increasing annual rainfall in Chile. This fact would suggest that A. caven populations occurring in the south are in better conditions for reproduction than northern populations, since pod-length is related to the amount of seeds inside the pods. The possible bearing of this southward tendency of increasing seed production upon the expansion of A. caven toward the more humid zones in southern Chile is discussed.

  3. Numerical Aerodynamic Simulation (NAS)

    NASA Technical Reports Server (NTRS)

    Peterson, V. L.; Ballhaus, W. F., Jr.; Bailey, F. R.

    1983-01-01

    The history of the Numerical Aerodynamic Simulation Program, which is designed to provide a leading-edge capability to computational aerodynamicists, is traced back to its origin in 1975. Factors motivating its development and examples of solutions to successively refined forms of the governing equations are presented. The NAS Processing System Network and each of its eight subsystems are described in terms of function and initial performance goals. A proposed usage allocation policy is discussed and some initial problems being readied for solution on the NAS system are identified.

  4. NAS-current status and future plans

    NASA Technical Reports Server (NTRS)

    Bailey, F. R.

    1987-01-01

    The Numerical Aerodynamic Simulation (NAS) has met its first major milestone, the NAS Processing System Network (NPSN) Initial Operating Configuration (IOC). The program has met its goal of providing a national supercomputer facility capable of greatly enhancing the Nation's research and development efforts. Furthermore, the program is fulfilling its pathfinder role by defining and implementing a paradigm for supercomputing system environments. The IOC is only the begining and the NAS Program will aggressively continue to develop and implement emerging supercomputer, communications, storage, and software technologies to strengthen computations as a critical element in supporting the Nation's leadership role in aeronautics.

  5. Inoculating Acacia koa with Bradyrhizobium and applying fertilizer in the nursery: effects on nodule formation and seedling growth

    Treesearch

    R. Kasten Dumroese; Douglass F. Jacobs; Anthony S. Davis

    2009-01-01

    Restoration of Acacia koa A. Gray (koa) forests on degraded sites in Hawaii is important for conservation of rare, endemic plants and animals and is often accomplished by planting nursery-grown seedlings. To be successful after outplanting, koa seedlings must access sufficient nutrients from the soil and outcompete other vegetation. Forming symbiotic...

  6. Termites, vertebrate herbivores, and the fruiting success of Acacia drepanolobium.

    PubMed

    Brody, Alison K; Palmer, Todd M; Fox-Dobbs, Kena; Doak, Dan F

    2010-02-01

    In African savannas, vertebrate herbivores are often identified as key determinants of plant growth, survivorship, and reproduction. However, plant reproduction is likely to be the product of responses to a suite of abiotic and biotic factors, including nutrient availability and interactions with antagonists and mutualists. In a relatively simple system, we examined the role of termites (which act as ecosystem engineers--modifying physical habitat and creating islands of high soil fertility), vertebrate herbivores, and symbiotic ants, on the fruiting success of a dominant plant, Acacia drepanolobium, in East African savannas. Using observational data, large-scale experimental manipulations, and analysis of foliar N, we found that Acacia drepanolobium trees growing at the edge of termite mounds were more likely to reproduce than those growing farther away, in off-mound soils. Although vertebrate herbivores preferentially used termite mounds as demonstrated by dung deposits, long-term exclusion of mammalian grazers did not significantly reduce A. drepanolobium fruit production. Leaf N was significantly greater in trees growing next to mounds than in those growing farther away, and this pattern was unaffected by exclusion of vertebrates. Thus, soil enrichment by termites, rather than through dung and urine deposition by large herbivores, is of primary importance to fruit production near mounds. Across all mound-herbivore treatment combinations, trees that harbored Crematogaster sjostedti were more likely to fruit than those that harbored one of the other three ant species. Although C. sjostedti is less aggressive than the other ants, it tends to inhabit large, old trees near termite mounds which are more likely to fruit than smaller ones. Termites play a key role in generating patches of nutrient-rich habitat important to the reproductive success of A. drepanolobium in East African savannas. Enhanced nutrient acquisition from termite mounds appears to allow plants to

  7. Genetic and Genomic Diversity Studies of Acacia Symbionts in Senegal Reveal New Species of Mesorhizobium with a Putative Geographical Pattern

    PubMed Central

    Diouf, Fatou; Diouf, Diegane; Klonowska, Agnieszka; Le Queré, Antoine; Bakhoum, Niokhor; Fall, Dioumacor; Neyra, Marc; Parrinello, Hugues; Diouf, Mayecor; Ndoye, Ibrahima; Moulin, Lionel

    2015-01-01

    Acacia senegal (L) Willd. and Acacia seyal Del. are highly nitrogen-fixing and moderately salt tolerant species. In this study we focused on the genetic and genomic diversity of Acacia mesorhizobia symbionts from diverse origins in Senegal and investigated possible correlations between the genetic diversity of the strains, their soil of origin, and their tolerance to salinity. We first performed a multi-locus sequence analysis on five markers gene fragments on a collection of 47 mesorhizobia strains of A. senegal and A. seyal from 8 localities. Most of the strains (60%) clustered with the M. plurifarium type strain ORS 1032T, while the others form four new clades (MSP1 to MSP4). We sequenced and assembled seven draft genomes: four in the M. plurifarium clade (ORS3356, ORS3365, STM8773 and ORS1032T), one in MSP1 (STM8789), MSP2 (ORS3359) and MSP3 (ORS3324). The average nucleotide identities between these genomes together with the MLSA analysis reveal three new species of Mesorhizobium. A great variability of salt tolerance was found among the strains with a lack of correlation between the genetic diversity of mesorhizobia, their salt tolerance and the soils samples characteristics. A putative geographical pattern of A. senegal symbionts between the dryland north part and the center of Senegal was found, reflecting adaptations to specific local conditions such as the water regime. However, the presence of salt does not seem to be an important structuring factor of Mesorhizobium species. PMID:25658650

  8. Responses to water stress of gas exchange and metabolites in Eucalyptus and Acacia spp.

    PubMed

    Warren, Charles R; Aranda, Ismael; Cano, F Javier

    2011-10-01

    Studies of water stress commonly examine either gas exchange or leaf metabolites, and many fail to quantify the concentration of CO₂ in the chloroplasts (C(c)). We redress these limitations by quantifying C(c) from discrimination against ¹³CO₂ and using gas chromatography-mass spectrometry (GC-MS) for leaf metabolite profiling. Five Eucalyptus and two Acacia species from semi-arid to mesic habitats were subjected to a 2 month water stress treatment (Ψ(pre-dawn) = -1.7 to -2.3 MPa). Carbohydrates dominated the leaf metabolite profiles of species from dry areas, whereas organic acids dominated the metabolite profiles of species from wet areas. Water stress caused large decreases in photosynthesis and C(c), increases in 17-33 metabolites and decreases in 0-9 metabolites. In most species, fructose, glucose and sucrose made major contributions to osmotic adjustment. In Acacia, significant osmotic adjustment was also caused by increases in pinitol, pipecolic acid and trans-4-hydroxypipecolic acid. There were also increases in low-abundance metabolites (e.g. proline and erythritol), and metabolites that are indicative of stress-induced changes in metabolism [e.g. γ-aminobutyric acid (GABA) shunt, photorespiration, phenylpropanoid pathway]. The response of gas exchange to water stress and rewatering is rather consistent among species originating from mesic to semi-arid habitats, and the general response of metabolites to water stress is rather similar, although the specific metabolites involved may vary. © 2011 Blackwell Publishing Ltd.

  9. Effect of different rates of spent coffee grounds (SCG) on composting process, gaseous emissions and quality of end-product.

    PubMed

    Santos, Cátia; Fonseca, João; Aires, Alfredo; Coutinho, João; Trindade, Henrique

    2017-01-01

    The use of spent coffee grounds (SCG) in composting for organic farming is a viable way of valorising these agro-industrial residues. In the present study, four treatments with different amounts of spent coffee grounds (SCG) were established, namely, C 0 (Control), C 10 , C 20 and C 40 , containing 0, 10, 20 and 40% of SCG (DM), respectively; and their effects on the composting process and the end-product quality characteristics were evaluated. The mixtures were completed with Acacia dealbata L. shoots and wheat straw. At different time intervals during composting, carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) emissions were measured and selected physicochemical characteristics of the composts were evaluated. During the composting process, all treatments showed a substantial decrease in total phenolics and total tannins, and an important increase in gallic acid. Emissions of greenhouse gases were very low and no significant difference between the treatments was registered. The results indicated that SCG may be successfully composted in all proportions. However C 40 , was the treatment which combined better conditions of composting, lower GHG emissions and better quality of end product. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Preparation and characterization of cross-linked excipient of coprocessed xanthan gum-acacia gum as matrix for sustained release tablets

    NASA Astrophysics Data System (ADS)

    Surini, Silvia; Wati, Dina Risma; Syahdi, Rezi Riadhi

    2018-02-01

    Sustained release tablet is solid dosage form which is designed to release drugs slowly in the body. This research was intended to prepare and characterize the cross-linked excipients of co-processed xanthan gum-acacia gum (CL-Co-XGGA) as matrices for sustained release tablets with gliclazide as a model drug. CL-Co-XGGA excipients were cross-linked materials of co-processed excipients of xanthan gum-acacia gum (Co-XGGA) using sodium trimetaphosphate. Co-processed excipients of xanthan gum-acacia gum were prepared in the ratio of each excipient 1:2, 1:1 and 2:1. Co-XGGA and CL-Co-XGGA excipients were characterized physically, chemically and functionally. Then, the sustained release (SR) tablets were formulated by wet granulation method using CL-Co-XGGA excipients as matrices. Also, the dissolution study of the gliclazide SR tablets was carried out in phosphate buffer medium pH 7,4 containing sodium lauryl sulphate 0.2% for 12 hours. The results showed that the degree of substitution (DS) of CL-Co-XGGA 1:2, 1:1, 2:1 excipients were respectively 0.067, 0.082 and 0.08. Besides that, the excipients gel strengths were 14.03, 17.27 and 20,70 gF, respectively. The cross-linked excipients had improved flow properties and swelling capability compared to the Co-XGGA excipients. The results of the gliclazide SR tablets evaluations showed that all tablets were passed all tablet requirements. Moreover, the gliclazide release from SR tablets F1 - F6 revealed the sustained release profile, which was following zero order kinetics (F1, F2, F3, F6) and Higuchi kinetics (F4 and F5). It could be concluded that the obtained CL-Co-XGGA excipients might be used as matrices for sustained release tablets and could retard drug release up to 8 until 32 hours.

  11. Glucanases and Chitinases as Causal Agents in the Protection of Acacia Extrafloral Nectar from Infestation by Phytopathogens1[W][OA

    PubMed Central

    González-Teuber, Marcia; Pozo, María J.; Muck, Alexander; Svatos, Ales; Adame-Álvarez, Rosa M.; Heil, Martin

    2010-01-01

    Nectars are rich in primary metabolites and attract mutualistic animals, which serve as pollinators or as an indirect defense against herbivores. Their chemical composition makes nectars prone to microbial infestation. As protective strategy, floral nectar of ornamental tobacco (Nicotiana langsdorffii × Nicotiana sanderae) contains “nectarins,” proteins producing reactive oxygen species such as hydrogen peroxide. By contrast, pathogenesis-related (PR) proteins were detected in Acacia extrafloral nectar (EFN), which is secreted in the context of defensive ant-plant mutualisms. We investigated whether these PR proteins protect EFN from phytopathogens. Five sympatric species (Acacia cornigera, A. hindsii, A. collinsii, A. farnesiana, and Prosopis juliflora) were compared that differ in their ant-plant mutualism. EFN of myrmecophytes, which are obligate ant-plants that secrete EFN constitutively to nourish specialized ant inhabitants, significantly inhibited the growth of four out of six tested phytopathogenic microorganisms. By contrast, EFN of nonmyrmecophytes, which is secreted only transiently in response to herbivory, did not exhibit a detectable inhibitory activity. Combining two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis with nanoflow liquid chromatography-tandem mass spectrometry analysis confirmed that PR proteins represented over 90% of all proteins in myrmecophyte EFN. The inhibition of microbial growth was exerted by the protein fraction, but not the small metabolites of this EFN, and disappeared when nectar was heated. In-gel assays demonstrated the activity of acidic and basic chitinases in all EFNs, whereas glucanases were detected only in EFN of myrmecophytes. Our results demonstrate that PR proteins causally underlie the protection of Acacia EFN from microorganisms and that acidic and basic glucanases likely represent the most important prerequisite in this defensive function. PMID:20023149

  12. Effect of polyethylene glycol 4000 supplementation on the performance of indigenous Pedi goats fed different levels of Acacia nilotica leaf meal and ad libitum Buffalo grass hay.

    PubMed

    Motubatse, M R; Ng'ambi, J W; Norris, D; Malatje, M M

    2008-04-01

    In a first of two experiments, twenty yearling male Pedi goats weighing 21.3 +/- 0.5 kg live weight were used in a 37-day study in a 2 (levels of PEG 4000) x 2 (levels ofAcacia) Factorial arrangement in a Completely Randomised Design to determine the effect of the level of Acacia nilotica leaf meal supplementation plus 23 g polyethylene glycol 4000 on diet intake and digestibility, and growth rate of Pedi goats fed ad libitum Buffalo grass hay. Acacia nilotica leaf meal contained high amounts of total phenolics (2.04% DM) and low amounts of condensed tannins; both extracted (0.37% DM) and unextracted (1.83% DM). Supplementation with PEG 4000 increased (P < 0.05) crude protein intake as the level of Acacia nilotica leaf meal increased from 80 to 120 g. Similarly, treatment with PEG 4000 improved (P < 0.05) DM, OM and CP digestibilities when compared to 80 g Acacia nilotica leaf meal. Supplementation with PEG 4000 resulted in an increase (P < 0.05) in blood urea concentrations. Polyethylene glycol 4000 has the potential to improve the feeding value of A. nilotica leaf meal and can, therefore, be used in the feeding systems for ruminant animals. The second experiment determined the effect of A. nilotica leaf meal supplementation on in vitro digestibility of the diets similar to the actual ratios of the first experiment. Level of A. nilotica leaf meal supplementation plus 23 g PEG 4000 supplementation improved (P < 0.05) in vitro DM, OM and CP digestibilities where 120 g A. nilotica leaf meal was supplemented. Similarly, 23 g PEG 4000 supplementation also improved (P < 0.05) in vitro CP digestibility where 80 g A. nilotica leaf meal was supplemented. In vivo DM and OM digestibilities were best predicted from in vitro DM and OM digestibilities while in vivo CP was explained by in vitro OM and CP digestibilities. It is, therefore, concluded that in vitro DM and OM digestibilities have good capacity to predict in vivo DM and OM digestibilities while OM and CP

  13. The SMART-NAS Testbed

    NASA Technical Reports Server (NTRS)

    Aquilina, Rudolph A.

    2015-01-01

    The SMART-NAS Testbed for Safe Trajectory Based Operations Project will deliver an evaluation capability, critical to the ATM community, allowing full NextGen and beyond-NextGen concepts to be assessed and developed. To meet this objective a strong focus will be placed on concept integration and validation to enable a gate-to-gate trajectory-based system capability that satisfies a full vision for NextGen. The SMART-NAS for Safe TBO Project consists of six sub-projects. Three of the sub-projects are focused on exploring and developing technologies, concepts and models for evolving and transforming air traffic management operations in the ATM+2 time horizon, while the remaining three sub-projects are focused on developing the tools and capabilities needed for testing these advanced concepts. Function Allocation, Networked Air Traffic Management and Trajectory Based Operations are developing concepts and models. SMART-NAS Test-bed, System Assurance Technologies and Real-time Safety Modeling are developing the tools and capabilities to test these concepts. Simulation and modeling capabilities will include the ability to assess multiple operational scenarios of the national airspace system, accept data feeds, allowing shadowing of actual operations in either real-time, fast-time and/or hybrid modes of operations in distributed environments, and enable integrated examinations of concepts, algorithms, technologies, and NAS architectures. An important focus within this project is to enable the development of a real-time, system-wide safety assurance system. The basis of such a system is a continuum of information acquisition, analysis, and assessment that enables awareness and corrective action to detect and mitigate potential threats to continuous system-wide safety at all levels. This process, which currently can only be done post operations, will be driven towards "real-time" assessments in the 2035 time frame.

  14. Effects of Gum acacia aqueous extract on the histology of the intestine and enzymes of both the intestine and the pancreas of albino rats treated with Meloxicam

    PubMed Central

    Abd El-Mawla, Ahmed M. A.; Osman, Husam Eldien H.

    2011-01-01

    Background: Non-steroidal anti-inflammatory drugs (NSAIDs) cause gastrointestinal damage both in the upper and lower gastrointestinal tract, in addition to their undesirable side effects on the pancreas. Meloxicam like all NSAIDs has damaging effects on the gastrointestinal tract including perforations, ulcers and bleeding. Objective: The present work describes the effects of Gum acacia aqueous extract on the histology of intestine and enzymes of both intestine and Pancreas of albino rats treated with Meloxicam. Materials and Methods: This study was performed on four groups of equally weighed male rats, each group included ten animals; the first group was received a diet containing 0.2 mg/kg bw meloxicam per day; the second was given 1gm Gum acacia per day in its diet; the third was given meloxicam followed by gum in the same doses per day; while the fourth group (control rats) was placed on a normal diet and water. All rats were received their diet for a period of 21 days. Results: A considerable protective effect of Gum acacia aqueous extract on the histology of intestine of albino rats treated with meloxicam was recorded. In addition, the study displayed a significant increase (P < 0.001) in the intestinal enzymes; lipase, amylase, alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in the 1st and 3rd groups animals while these enzymes were significantly decreased (P < 0.001) in the 2nd group when compared with the 4th control group. Conclusion: This study concluded that Gum acacia provides a protection and defense against the harmful effects of meloxicam therapy used as one of the novel anti-Cox-1 and Cox-2 NSAIDs. PMID:21772755

  15. Effects of Gum acacia aqueous extract on the histology of the intestine and enzymes of both the intestine and the pancreas of albino rats treated with Meloxicam.

    PubMed

    Abd El-Mawla, Ahmed M A; Osman, Husam Eldien H

    2011-04-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) cause gastrointestinal damage both in the upper and lower gastrointestinal tract, in addition to their undesirable side effects on the pancreas. Meloxicam like all NSAIDs has damaging effects on the gastrointestinal tract including perforations, ulcers and bleeding. The present work describes the effects of Gum acacia aqueous extract on the histology of intestine and enzymes of both intestine and Pancreas of albino rats treated with Meloxicam. This study was performed on four groups of equally weighed male rats, each group included ten animals; the first group was received a diet containing 0.2 mg/kg bw meloxicam per day; the second was given 1gm Gum acacia per day in its diet; the third was given meloxicam followed by gum in the same doses per day; while the fourth group (control rats) was placed on a normal diet and water. All rats were received their diet for a period of 21 days. A considerable protective effect of Gum acacia aqueous extract on the histology of intestine of albino rats treated with meloxicam was recorded. In addition, the study displayed a significant increase (P < 0.001) in the intestinal enzymes; lipase, amylase, alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in the 1(st) and 3(rd) groups animals while these enzymes were significantly decreased (P < 0.001) in the 2(nd) group when compared with the 4(th) control group. This study concluded that Gum acacia provides a protection and defense against the harmful effects of meloxicam therapy used as one of the novel anti-Cox-1 and Cox-2 NSAIDs.

  16. Parent tree effects on reestablishment of Acacia koa in abandoned pasture and the influence of initial density on stand development

    Treesearch

    Paul G. Scowcroft

    2012-01-01

    Increasingly private landholders in Hawaii are considering native forest restoration for their lands, and some public agencies have already started such work. Initial efforts have focused on reestablishing Acacia koa to recover alien-grass-dominated sites. This study was done in Hakalau Forest National Wildlife Refuge, Island of Hawaii, to...

  17. UAS Integration into the NAS Project

    NASA Technical Reports Server (NTRS)

    Bauer, Jeff

    2010-01-01

    The goal of the UAS Integration in the NAS Project is to contribute capabilities that reduce technical barriers related to the safety and operational challenges associated with enabling routine UAS access to the NAS This goal will be accomplished through a two-phased approach of system-level integration of key concepts, technologies and/or procedures, and demonstrations of integrated capabilities in an operationally relevant environment. Technical objectives include: PHASE 1: a) Validating the key technical areas identified by this project. System-level analyses, a State of the Art Analysis (SOAA), and a ConOps will identify the challenges and barriers preventing routine UAS access to the NAS. b) Developing a national roadmap and gap analysis identifying specific deliverables in the area of operations, procedures, and technologies that will impact future policy decisions. PHASE 2: a) Provide regulators with a methodology for developing airworthiness requirements for UAS and data to support development of certifications standards and regulatory guidance. b) Provide systems-level integrated testing of concepts and/or capabilities that address barriers to routine access to the NAS. Through simulation and flight testing, address issues including separation assurance, communications requirements, and Pilot Aircraft Interfaces (PAIs) in operationally relevant environments

  18. The Need for Vendor Source Code at NAS. Revised

    NASA Technical Reports Server (NTRS)

    Carter, Russell; Acheson, Steve; Blaylock, Bruce; Brock, David; Cardo, Nick; Ciotti, Bob; Poston, Alan; Wong, Parkson; Chancellor, Marisa K. (Technical Monitor)

    1997-01-01

    The Numerical Aerodynamic Simulation (NAS) Facility has a long standing practice of maintaining buildable source code for installed hardware. There are two reasons for this: NAS's designated pathfinding role, and the need to maintain a smoothly running operational capacity given the widely diversified nature of the vendor installations. NAS has a need to maintain support capabilities when vendors are not able; diagnose and remedy hardware or software problems where applicable; and to support ongoing system software development activities whether or not the relevant vendors feel support is justified. This note provides an informal history of these activities at NAS, and brings together the general principles that drive the requirement that systems integrated into the NAS environment run binaries built from source code, onsite.

  19. Water absorption and method improvement concerning electrical conductivity testing Acacia mangium (Fabaceae) seeds.

    PubMed

    de Oliveira, Daniel Luiz; Smiderle, Oscar Jose; Paulino, Pollyana Priscila Schuertz; Souza, Aline das Graças

    2016-12-01

    Acacia is an important forest species of rapid growth whose seeds have tegument dormancy. In this work it was intended to characterize water absorption pattern after seed dormancy break, and to determine the amount of water, container size and the need of breaking the tegument dormancy, as to perform electrical conductivity test in small and large seeds of Acacia mangium (Fabaceae). The seeds were collected from 10, 8 and 6 years old trees established in poor yielding-capacity soils on savannah areas of Roraima, Brazil; seeds were classified in six lots concerning to seed size and tree age. Germination tests (50 seeds and four replications per lot) were carried out on germitest® paper maintained on gerbox at 25 °C. Imbibition was verified by seed weighing at different times (0, 2, 5, 8, 12, 16, 24, 36, 48, 60, 72, 84, 96 and 120 hours). The electrical conductivity test consisted of three experiments, distinguished by the amount of water used and by the container size in which seeds were immersed. Seeds of A. mangium coming from 10 years old trees presented increased germination percent and germination speed than seeds of six-year old trees. Small seeds presented increased in electrical conductivity and water absorption until 120 hours when compared to large seeds. The immersion of seeds of A. mangium in 40 mL of distilled water into 180 mL plastic containers, after dormancy break, it is indicated for the determination of electrical conductivity test. The ratio of electrolytes by seed mass, after 24 hours of immersion in water, turns electrical conductivity test more accurate concerning A. mangium seeds.

  20. Assessment of the effect of condensed (acacia and quebracho) and hydrolysable (chestnut and valonea) tannins on rumen fermentation and methane production in vitro.

    PubMed

    Hassanat, Fadi; Benchaar, Chaouki

    2013-01-01

    Tannins added to animal diets may have a positive effect on energy and protein utilisation in the rumen. The objective of this study was to examine the impact of different sources and concentrations (20, 50, 100, 150 and 200 g kg⁻¹ dry matter (DM)) of condensed (acacia and quebracho) and hydrolysable (chestnut and valonea) tannins on rumen microbial fermentation in vitro. The experiment also included a negative control with no tannins (control) and a positive control with monensin (10 mg L⁻¹). In vitro gas production and total volatile fatty acid (VFA) concentration decreased as tannin concentration increased. Addition of acacia, chestnut or valonea tannins at ≥ 50 g kg⁻¹ or quebracho tannins at ≥ 100 g kg⁻¹ resulted in a decrease (up to 40%) in methane (CH₄) production compared with the control. Valonea tannins were the only tannin source that reduced (-11%) CH₄ production at 50 g kg⁻¹ without affecting VFA concentration. Tannin treatments reduced ammonia (NH₃) and branched-chain VFA concentrations, indicating a reduction in ruminal protein degradation. Monensin reduced CH₄ production (-37%) and NH₃ concentration (-20%) without affecting total VFA concentration. Supplying acacia, chestnut or valonea tannins at 50 g kg⁻¹ has the potential to reduce CH₄ production and ruminal protein degradation with minimum detrimental effects on efficiency of ruminal fermentation. Copyright © 2012 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.

  1. Chance long-distance or human-mediated dispersal? How Acacia s.l. farnesiana attained its pan-tropical distribution.

    PubMed

    Bell, Karen L; Rangan, Haripriya; Fernandes, Manuel M; Kull, Christian A; Murphy, Daniel J

    2017-04-01

    Acacia s.l. farnesiana , which originates from Mesoamerica, is the most widely distributed Acacia s.l. species across the tropics. It is assumed that the plant was transferred across the Atlantic to southern Europe by Spanish explorers, and then spread across the Old World tropics through a combination of chance long-distance and human-mediated dispersal. Our study uses genetic analysis and information from historical sources to test the relative roles of chance and human-mediated dispersal in its distribution. The results confirm the Mesoamerican origins of the plant and show three patterns of human-mediated dispersal. Samples from Spain showed greater genetic diversity than those from other Old World tropics, suggesting more instances of transatlantic introductions from the Americas to that country than to other parts of Africa and Asia. Individuals from the Philippines matched a population from South Central Mexico and were likely to have been direct, trans-Pacific introductions. Australian samples were genetically unique, indicating that the arrival of the species in the continent was independent of these European colonial activities. This suggests the possibility of pre-European human-mediated dispersal across the Pacific Ocean. These significant findings raise new questions for biogeographic studies that assume chance or transoceanic dispersal for disjunct plant distributions.

  2. Chance long-distance or human-mediated dispersal? How Acacia s.l. farnesiana attained its pan-tropical distribution

    PubMed Central

    Rangan, Haripriya; Fernandes, Manuel M.; Kull, Christian A.; Murphy, Daniel J.

    2017-01-01

    Acacia s.l. farnesiana, which originates from Mesoamerica, is the most widely distributed Acacia s.l. species across the tropics. It is assumed that the plant was transferred across the Atlantic to southern Europe by Spanish explorers, and then spread across the Old World tropics through a combination of chance long-distance and human-mediated dispersal. Our study uses genetic analysis and information from historical sources to test the relative roles of chance and human-mediated dispersal in its distribution. The results confirm the Mesoamerican origins of the plant and show three patterns of human-mediated dispersal. Samples from Spain showed greater genetic diversity than those from other Old World tropics, suggesting more instances of transatlantic introductions from the Americas to that country than to other parts of Africa and Asia. Individuals from the Philippines matched a population from South Central Mexico and were likely to have been direct, trans-Pacific introductions. Australian samples were genetically unique, indicating that the arrival of the species in the continent was independent of these European colonial activities. This suggests the possibility of pre-European human-mediated dispersal across the Pacific Ocean. These significant findings raise new questions for biogeographic studies that assume chance or transoceanic dispersal for disjunct plant distributions. PMID:28484637

  3. Physico-mechanical properties of plywood bonded with ecological adhesives from Acacia mollissima tannins and lignosulfonates

    NASA Astrophysics Data System (ADS)

    Rhazi, Naima; Oumam, Mina; Sesbou, Abdessadek; Hannache, Hassan; Charrier-El Bouhtoury, Fatima

    2017-06-01

    The objective of this research was to develop ecological adhesives for bonding plywood panels using lignosulfonates, a common waste product of the wood pulp industry, and natural tannin extracted from Moroccan bark of Acacia mollissima using different process. Natural tannin and lignin were used in wood adhesives formulation to substitute resins based on phenol and formaldehyde. To achieve this, the lignosulfonates were glyoxalated to enhance their reactivity and the used tannins obtained by three different extraction methods were compared with commercial mimosa tannin. The proportion of Acacia mollissima tannins and lignosulfonates, the pressing time, the pressing temperature, and the pressure used were studied to improve mechanical properties, and bonding quality of plywood panel. The properties of plywood panels produced with these adhesives were tested in accordance with normative tests. Thus, the tensile strength, and the shear strength were measured. The results showed that the performance of the plywood panels made using biobased tannin adhesives was influenced by physical conditions such as pressure, press temperature as well as by chemical conditions, such as the tannin-lignin ratio. It exhibited excellent mechanical properties comparable to commercially available phenol-formaldehyde plywood adhesives. This study showed that biobased adhesives formulations presented good and higher mechanical performance and no formaldehyde emission. Contribution to the topical issue "Materials for Energy harvesting, conversion and storage II (ICOME 2016)", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  4. Passive restoration augments active restoration in deforested landscapes: the role of root suckering adjacent to planted stands of Acacia koa

    Treesearch

    Paul G. Scowcroft; Justin T. Yeh

    2013-01-01

    Active forest restoration in Hawaii’s Hakalau Forest National Wildlife Refuge has produced a network of Acacia koa tree corridors and islands in deforested grasslands. Passive restoration by root suckering has potential to expand tree cover and close gaps between planted stands. This study documents rates of encroachment into grassland, clonal...

  5. Geoecosystem-related dynamics of Acacia populations in the Israeli hyper-arid Arava Valley

    NASA Astrophysics Data System (ADS)

    Stavi, Ilan; Avni, Yoav; Yizhaq, Hezi; Bel, Golan; Ginat, Hanan

    2017-04-01

    Similar to other Middle-Eastern and North-African drylands, Acacia populations across the hyper-arid Arava Valley of Israel have experienced dramatic phonological changes during the last few decades. These changes have been expressed with high mortality rates and low recruitment rates. Species of the Acacia trees across the region include the A. pachyceras, A. raddiana, and A. tortilis. We studied the recruitment and decay rate of seedlings. Data obtained revealed that during a whole year after germination, overall survival rate of seedlings was 2%. Also, data showed that the main impediment to recruitment and survival of seedlings was insufficient access to soil-water, resulting in their mortality due to drying. Another, secondary impediment was imposed by erosional and depositional processes under heavy floods, resulting in the elimination or burial of seedlings. Modeling of results revealed that the drying of seedlings is defined with a constant mortality rate, which fits an exponential decay function. At the same time, seedling mortality due to fluvial processes is defined with a mortality rate that grows with time, which fits a Gaussian decay function. Also, we investigated the effect of latitude, basin size, and microhabitat on vitality of existing trees. Results showed negative effect of latitude on tree mortality, fitting with the generally greater precipitation rates in the northern- than in the southern- Arava Valley. At the same time, no effect on tree mortality was recorded for basin size, proposing that in such extreme drylands, runoff ratio becomes more non-linear with increasing watershed size because of the greater dominance of ephemeral stream transmission losses, as well as due to the partial storm area coverage. Nor did the location in microhabitat across the valley floor affect tree mortality rate, highlighting the bimodal effect of greater access to flood water, potentially increasing survivability of old trees, but at the same time, imposing

  6. NASA's UAS NAS Access Project

    NASA Technical Reports Server (NTRS)

    Johnson, Charles W.

    2011-01-01

    The vision of the Unmanned Aircraft System (UAS) Integration in the National Airspace System (NAS) Project is "A global transportation system which allows routine access for all classes of UAS." The goal of the UAS Integration in the NAS Project is to "contribute capabilities that reduce technical barriers related to the safety and operational challenges associated with enabling routine UAS access to the NAS." This goal will be accomplished through a two-phased approach based on development of system-level integration of key concepts, technologies and/or procedures, and demonstrations of integrated capabilities in an operationally relevant environment. Phase 1 will take place the first two years of the Project and Phase 2 will take place the following three years. The Phase 1 and 2 technical objectives are: Phase 1: Developing a gap analysis between current state of the art and the Next Generation Air Transportation System (NextGen) UAS Concept of Operations . Validating the key technical areas identified by this Project . Conducting initial modeling, simulation, and flight testing activities . Completing Sub-project Phase 1 deliverables (spectrum requirements, comparative analysis of certification methodologies, etc.) and continue Phase 2 preparation (infrastructure, tools, etc.) Phase 2: Providing regulators with a methodology for developing airworthiness requirements for UAS, and data to support development of certifications standards and regulatory guidance . Providing systems-level, integrated testing of concepts and/or capabilities that address barriers to routine access to the NAS. Through simulation and flight testing, address issues including separation assurance, communications requirements, and human systems integration in operationally relevant environments. The UAS in the NAS Project will demonstrate solutions in specific technology areas, which will address operational/safety issues related to UAS access to the NAS. Since the resource allocation for

  7. Enterocutaneous Fistula: Different Surgical Intervention Techniques for Closure along with Comparative Evaluation of Aluminum Paint, Karaya Gum (Hollister) and Gum Acacia for Peristomal Skin Care

    PubMed Central

    Namrata; Ahmad, Shabi

    2015-01-01

    Introduction Gastrointestinal fistulas are serious complications and are associated with high morbidity and mortality rates. In majority of the patients, fistulas are treatable. However, the treatment is very complex and often multiple therapies are required. These highly beneficial treatment options which could shorten fistula closure time also result in considerable hospital cost savings. Aim This study was planned to study aetiology, clinical presentation, morbidity and mortality of enterocutaneous fistula and to evaluate the different surgical intervention techniques for closure of enterocutaneous fistula along with a comparative evaluation of different techniques for management of peristomal skin with special emphasis on aluminum paint, Karaya gum (Hollister) and Gum Acacia. Materials and Methods This prospective observational study was conducted in the Department of Surgery, M.L.N. Medical College, Allahabad and its associated hospital (S.R.N. Hospital, Allahabad) for a period of five years. Results Majority of enterocutaneous fistula were of small bowel and medium output fistulas (500-1000 ml/24hours). Most of the patients were treated with conservative treatment as compared to surgical intervention. Large bowel fistula has maximum spontaneous closure rate compare to small bowel and duodenum. Number of orifice whether single or multiple does not appear to play statistically significant role in spontaneous closure of fistula. Serum Albumin is a significantly important predictor of spontaneous fistula closure and mortality. Surgical management appeared to be the treatment of choice in distal bowel fistula. The application of karaya gum (Hollister kit), Gum Acacia and Aluminum Paint gave similar outcome. Conclusion Postoperative fistulas are the most common aetiology of enterocutaneous fistula and various factors do play role in management. Peristomal skin care done with Karaya Gum, Gum Acacia and Aluminum Paint has almost equal efficiency in management of skin

  8. Growth response of Acacia koa trees to thinning, grass control, and phosphorus fertilization in a secondary forest in Hawai‘i

    Treesearch

    Paul G. Scowcroft; J.B. Friday; Travis Idol; Nicklos Dudley; Janis Haraguchi; Dean Meason

    2007-01-01

    Koa (Acacia koa A. Gray) is an endemic Hawaiian hardwood tree of high ecological, cultural and economic value. Despite its multiple values, research on the silviculture of koa has been minimal until recently because the preferred land-use was pasture for livestock, and logging was done mainly to facilitate and reduce the costs of conversion. This...

  9. Nucleotide-dependent switch in proteasome assembly mediated by the Nas6 chaperone

    PubMed Central

    Li, Frances; Tian, Geng; Langager, Deanna; Sokolova, Vladyslava; Finley, Daniel; Park, Soyeon

    2017-01-01

    The proteasome is assembled via the nine-subunit lid, nine-subunit base, and 28-subunit core particle (CP). Previous work has shown that the chaperones Rpn14, Nas6, Hsm3, and Nas2 each bind a specific ATPase subunit of the base and antagonize base–CP interaction. Here, we show that the Nas6 chaperone also obstructs base–lid association. Nas6 alternates between these two inhibitory modes according to the nucleotide state of the base. When ATP cannot be hydrolyzed, Nas6 interferes with base–lid, but not base–CP, association. In contrast, under conditions of ATP hydrolysis, Nas6 obstructs base–CP, but not base–lid, association. Modeling of Nas6 into cryoelectron microscopy structures of the proteasome suggests that Nas6 controls both base–lid affinity and base–CP affinity through steric hindrance; Nas6 clashes with the lid in the ATP-hydrolysis–blocked proteasome, but clashes instead with the CP in the ATP-hydrolysis–competent proteasome. Thus, Nas6 provides a dual mechanism to control assembly at both major interfaces of the proteasome. PMID:28137839

  10. DNA barcoding for conservation, seed banking and ecological restoration of Acacia in the Midwest of Western Australia.

    PubMed

    Nevill, Paul G; Wallace, Mark J; Miller, Joseph T; Krauss, Siegfried L

    2013-11-01

    We used DNA barcoding to address an important conservation issue in the Midwest of Western Australia, working on Australia's largest genus of flowering plant. We tested whether or not currently recommended plant DNA barcoding regions (matK and rbcL) were able to discriminate Acacia taxa of varying phylogenetic distances, and ultimately identify an ambiguously labelled seed collection from a mine-site restoration project. Although matK successfully identified the unknown seed as the rare and conservation priority listed A. karina, and was able to resolve six of the eleven study species, this region was difficult to amplify and sequence. In contrast, rbcL was straightforward to recover and align, but could not determine the origin of the seed and only resolved 3 of the 11 species. Other chloroplast regions (rpl32-trnL, psbA-trnH, trnL-F and trnK) had mixed success resolving the studied taxa. In general, species were better resolved in multilocus data sets compared to single-locus data sets. We recommend using the formal barcoding regions supplemented with data from other plastid regions, particularly rpl32-trnL, for barcoding in Acacia. Our study demonstrates the novel use of DNA barcoding for seed identification and illustrates the practical potential of DNA barcoding for the growing discipline of restoration ecology. © 2013 John Wiley & Sons Ltd.

  11. Determination of composition of non-homogeneous GaInNAs layers

    NASA Astrophysics Data System (ADS)

    Pucicki, D.; Bielak, K.; Ściana, B.; Radziewicz, D.; Latkowska-Baranowska, M.; Kováč, J.; Vincze, A.; Tłaczała, M.

    2016-01-01

    Dilute nitride GaInNAs alloys grown on GaAs have become perspective materials for so called low-cost GaAs-based devices working within the optical wavelength range up to 1.6 μm. The multilayer structures of GaInNAs/GaAs multi-quantum well (MQW) samples usually are analyzed by using high resolution X-ray diffraction (HRXRD) measurements. However, demands for precise structural characterization of the GaInNAs containing heterostructures requires taking into consideration all inhomogeneities of such structures. This paper describes some of the material challenges and progress in structural characterization of GaInNAs layers. A new algorithm for structural characterization of dilute nitrides which bounds contactless electro-reflectance (CER) or photo-reflectance (PR) measurements and HRXRD analysis results together with GaInNAs quantum well band diagram calculation is presented. The triple quantum well (3QW) GaInNAs/GaAs structures grown by atmospheric-pressure metalorganic vapor-phase epitaxy (AP-MOVPE) were investigated according to the proposed algorithm. Thanks to presented algorithm, more precise structural data including the nonuniformity in the growth direction of GaInNAs/GaAs QWs were achieved. Therefore, the proposed algorithm is mentioned as a nondestructive method for characterization of multicomponent inhomogeneous semiconductor structures with quantum wells.

  12. NATIONAL ALCOHOL SURVEY (NAS)

    EPA Science Inventory

    National Alcohol Survey (NAS) is designed to assess the trends in drinking practices and problems in the national population, including attitudes, norms, treatment and experiences and adverse consequences. It also studies the effects of public policy on drinking practices (i.e., ...

  13. UAS NAS IHITL Test Readiness Review (TRR)

    NASA Technical Reports Server (NTRS)

    Murphy, Jim; Brignola, Michael P.; Rorie, Conrad; Santiago, Confesor; Guminsky, Mike; Cross, Ken

    2014-01-01

    Requesting release of IHITL test readiness review (TRR) charts to ensure UAS-NAS project primary stakeholders, the Federal Aviation Administration through the RTCA special committee -228 and the Office of the Secretary of Defense Sense and Avoid Science and Research Panel, are well informed on the IHITL test plan and expected outcomes as they relate to their needs to safely fly UAS in the NAS.

  14. Forest growth along a rainfall gradient in Hawaii: Acacia koa stand structure, productivity, foliar nutrients, and water- and nutrient-use efficiencies

    Treesearch

    Robin A. Harrington; James H. Fownes; Frederick C. Meinzer; Paul G. Scowcroft

    1995-01-01

    We tested whether variation in growth of native koa (Acacia koa) forest along a rainfall gradient was attributable to differences in leaf area index (LAI) or to differences in physiological performance per unit of leaf area. Koa stands were studied on western Kauai prior to Hurricane Iniki, and ranged from 500 to 1130 m elevation and from 850 to...

  15. Litter-forager termite mounds enhance the ectomycorrhizal symbiosis between Acacia holosericea A. Cunn. Ex G. Don and Scleroderma dictyosporum isolates.

    PubMed

    Duponnois, Robin; Assikbetse, Komi; Ramanankierana, Heriniaina; Kisa, Marija; Thioulouse, Jean; Lepage, Michel

    2006-05-01

    The hypothesis of the present study was that the termite mounds of Macrotermes subhyalinus (MS) (a litter-forager termite) were inhabited by a specific microflora that could enhance with the ectomycorrhizal fungal development. We tested the effect of this feeding group mound material on (i) the ectomycorrhization symbiosis between Acacia holosericea (an Australian Acacia introduced in the sahelian areas) and two ectomycorrhizal fungal isolates of Scleroderma dictyosporum (IR408 and IR412) in greenhouse conditions, (ii) the functional diversity of soil microflora and (iii) the diversity of fluorescent pseudomonads. The results showed that the termite mound amendment significantly increased the ectomycorrhizal expansion. MS mound amendment and ectomycorrhizal inoculation induced strong modifications of the soil functional microbial diversity by promoting the multiplication of carboxylic acid catabolizing microorganisms. The phylogenetic analysis showed that fluorescent pseudomonads mostly belong to the Pseudomonads monteillii species. One of these, P. monteillii isolate KR9, increased the ectomycorrhizal development between S. dictyosporum IR412 and A. holosericea. The occurrence of MS termite mounds could be involved in the expansion of ectomycorrhizal symbiosis and could be implicated in nutrient flow and local diversity.

  16. National Airspace System (NAS) open system architecture and protocols

    DOT National Transportation Integrated Search

    2003-08-14

    This standard establishes the open systems data communications architecture and authorized protocol standards for the National Airspace System (NAS). The NAS will consist of various types of processors and communications networks procured from a vari...

  17. Natural attenuation software (NAS): Assessing remedial strategies and estimating timeframes

    USGS Publications Warehouse

    Mendez, E.; Widdowson, M.; Chapelle, F.; Casey, C.

    2005-01-01

    Natural Attenuation Software (NAS) is a screening tool to estimate remediation timeframes for monitored natural attenuation (MNA) and to assist in decision-making on the level of source zone treatment in conjunction with MNA using site-specific remediation objectives. Natural attenuation processes that NAS models include are advection, dispersion, sorption, non-aqueous phase liquid (NAPL) dissolution, and biodegradation of either petroleum hydrocarbons or chlorinated ethylenes. Newly-implemented enhancements to NAS designed to maximize the utility of NAS for site managers were observed. NAS has expanded source contaminant specification options to include chlorinated ethanes and chlorinated methanes, and to allow for the analysis of any other user-defined contaminants that may be subject to microbially-mediated transformations (heavy metals, radioisotopes, etc.). Included is the capability to model co-mingled plumes, with constituents from multiple contaminant categories. To enable comparison of remediation timeframe estimates between MNA and specific engineered remedial actions , NAS was modified to incorporate an estimation technique for timeframes associated with pump-and-treat remediation technology for comparison to MNA. This is an abstract of a paper presented at the 8th International In Situ and On-Site Bioremediation Symposium (Baltimore, MD 6/6-9/2005).

  18. Salt tolerance traits increase the invasive success of Acacia longifolia in Portuguese coastal dunes.

    PubMed

    Morais, Maria Cristina; Panuccio, Maria Rosaria; Muscolo, Adele; Freitas, Helena

    2012-06-01

    Salt tolerance of two co-occurring legumes in coastal areas of Portugal, a native species--Ulex europaeus, and an invasive species--Acacia longifolia, was evaluated in relation to plant growth, ion content and antioxidant enzyme activities. Plants were submitted to four concentrations of NaCl (0, 50, 100 and 200 mM) for three months, under controlled conditions. The results showed that NaCl affects the growth of both species in different ways. Salt stress significantly reduced the plant height and the dry weight in Acacia longifolia whereas in U. europaeus the effect was not significant. Under salt stress, the root:shoot ratio (W(R):W(S)) and root mass ratio (W(R):W(RS)) increased as a result of increasing salinity in A. longifolia but the same was not observed in U. europaeus. In addition, salt stress caused a significant accumulation of Na+, especially in U. europaeus, and a decrease in K+ content and K+/Na+ ratio. The activities of antioxidant enzymes were higher in A. longifolia compared to U. europaeus. In A. longifolia, catalase (CAT, EC 1.11.1.6) and glutathione reductase (GR, EC 1.6.4.2.) activities increased significantly, while ascorbate peroxidase (APX, EC 1.11.1.11) and peroxidase (POX, EC 1.11.1.7) activities remained unchanged in comparison with the control. In U. europaeus, NaCl concentration significantly reduced APX activity but did not significantly affect CAT, GR and POX activities. Our results suggest that the invasive species copes better with salinity stress in part due to a higher rates of CAT and GR activities and a higher K+/Na+ ratio, which may represent an additional advantage when competing with native species in co-occurring salty habitats. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  19. Evaluation of antiviral activity of Ocimum sanctum and Acacia arabica leaves extracts against H9N2 virus using embryonated chicken egg model.

    PubMed

    Ghoke, S S; Sood, R; Kumar, N; Pateriya, A K; Bhatia, S; Mishra, A; Dixit, R; Singh, V K; Desai, D N; Kulkarni, D D; Dimri, U; Singh, V P

    2018-06-05

    In the view of endemic avian influenza H9N2 infection in poultry, its zoonotic potential and emergence of antiviral resistance, two herbal plants, Ocimum sanctum and Acacia arabica, which are easily available throughout various geographical locations in India were taken up to study their antiviral activity against H9N2 virus. We evaluated antiviral efficacy of three different extracts each from leaves of O. sanctum (crude extract, terpenoid and polyphenol) and A. arabica (crude extract, flavonoid and polyphenol) against H9N2 virus using in ovo model. The antiviral efficacy of different leaves extracts was systematically studied in three experimental protocols viz. virucidal (dose-dependent), therapeutic (time-dependent) and prophylactic (dose-dependent) activity employing in ovo model. The maximum non-toxic concentration of each herbal extracts of O. sanctum and A. arabica in the specific pathogen free embryonated chicken eggs was estimated and their antiviral efficacy was determined in terms of reduction in viral titres, measured by Haemagglutination (HA) and real time quantitative reverse transcription polymerase chain reaction (RT-qPCR) assays. All the extracts of O. sanctum (crude extract, terpenoid and polyphenol) and A. arabica (crude extract, flavonoid and polyphenol) showed significant virucidal activity, however, crude extract ocimum and terpenoid ocimum showed highly significant to significant (p < 0.001-0.01) decrease in virus genome copy numbers with lowest dose tested. Similarly, therapeutic effect was observed in all three extracts of O. sanctum in comparison to the virus control, nevertheless, crude extract ocimum and terpenoid ocimum maintained this effect for longer period of time (up to 72 h post-incubation). None of the leaves extracts of A. arabica had therapeutic effect at 24 and 48 h post-incubation, however, only the crude extract acacia and polyphenol acacia showed delayed therapeutic effect (72 h post-inoculation). Prophylactic

  20. Effect of Acacia karroo Supplementation on Growth, Ultimate pH, Colour and Cooking Losses of Meat from Indigenous Xhosa Lop-eared Goats

    PubMed Central

    Ngambu, S.; Muchenje, V.; Marume, U.

    2013-01-01

    The objective of the study was to determine the effect of Acacia karroo supplementation on growth, ultimate pH, colour and cooking losses of meat from indigenous Xhosa lop-eared goats. Eighteen castrated 4-month-old kids were used in the study until slaughter. The kids were subdivided in two treatment groups A. karroo supplemented (AK) and non-supplemented (NS). The supplemented goats were given 200 g per head per d of fresh A. karroo leaves. The kids were slaughtered on d 60 and sample cuttings for meat quality assessment were taken from the Longistimus dorsi muscle. The supplemented kids had higher (p<0.05) growth rates than the non-supplemented ones. The meat from the A. karroo supplemented goats had lower (p<0.05) ultimate pH and cooking loss than the meat from the non-supplemented goats. Acacia karroo supplemented goats produced higher (p<0.05) b* (yellowness) value, but supplementation had no significant effect on L* (lightness) and a* (redness) of the meat. Therefore, A. karroo supplementation improved growth performance and the quality of meat from goats. PMID:25049715

  1. NAS Grid Benchmarks. 1.0

    NASA Technical Reports Server (NTRS)

    VanderWijngaart, Rob; Frumkin, Michael; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    We provide a paper-and-pencil specification of a benchmark suite for computational grids. It is based on the NAS (NASA Advanced Supercomputing) Parallel Benchmarks (NPB) and is called the NAS Grid Benchmarks (NGB). NGB problems are presented as data flow graphs encapsulating an instance of a slightly modified NPB task in each graph node, which communicates with other nodes by sending/receiving initialization data. Like NPB, NGB specifies several different classes (problem sizes). In this report we describe classes S, W, and A, and provide verification values for each. The implementor has the freedom to choose any language, grid environment, security model, fault tolerance/error correction mechanism, etc., as long as the resulting implementation passes the verification test and reports the turnaround time of the benchmark.

  2. New NAS Parallel Benchmarks Results

    NASA Technical Reports Server (NTRS)

    Yarrow, Maurice; Saphir, William; VanderWijngaart, Rob; Woo, Alex; Kutler, Paul (Technical Monitor)

    1997-01-01

    NPB2 (NAS (NASA Advanced Supercomputing) Parallel Benchmarks 2) is an implementation, based on Fortran and the MPI (message passing interface) message passing standard, of the original NAS Parallel Benchmark specifications. NPB2 programs are run with little or no tuning, in contrast to NPB vendor implementations, which are highly optimized for specific architectures. NPB2 results complement, rather than replace, NPB results. Because they have not been optimized by vendors, NPB2 implementations approximate the performance a typical user can expect for a portable parallel program on distributed memory parallel computers. Together these results provide an insightful comparison of the real-world performance of high-performance computers. New NPB2 features: New implementation (CG), new workstation class problem sizes, new serial sample versions, more performance statistics.

  3. The NAS Computational Aerosciences Archive

    NASA Technical Reports Server (NTRS)

    Miceli, Kristina D.; Globus, Al; Lasinski, T. A. (Technical Monitor)

    1995-01-01

    In order to further the state-of-the-art in computational aerosciences (CAS) technology, researchers must be able to gather and understand existing work in the field. One aspect of this information gathering is studying published work available in scientific journals and conference proceedings. However, current scientific publications are very limited in the type and amount of information that they can disseminate. Information is typically restricted to text, a few images, and a bibliography list. Additional information that might be useful to the researcher, such as additional visual results, referenced papers, and datasets, are not available. New forms of electronic publication, such as the World Wide Web (WWW), limit publication size only by available disk space and data transmission bandwidth, both of which are improving rapidly. The Numerical Aerodynamic Simulation (NAS) Systems Division at NASA Ames Research Center is in the process of creating an archive of CAS information on the WWW. This archive will be based on the large amount of information produced by researchers associated with the NAS facility. The archive will contain technical summaries and reports of research performed on NAS supercomputers, visual results (images, animations, visualization system scripts), datasets, and any other supporting meta-information. This information will be available via the WWW through the NAS homepage, located at http://www.nas.nasa.gov/, fully indexed for searching. The main components of the archive are technical summaries and reports, visual results, and datasets. Technical summaries are gathered every year by researchers who have been allotted resources on NAS supercomputers. These summaries, together with supporting visual results and references, are browsable by interested researchers. Referenced papers made available by researchers can be accessed through hypertext links. Technical reports are in-depth accounts of tools and applications research projects

  4. Chemical composition and allelopathic potential of essential oils obtained from Acacia cyanophylla Lindl. Cultivated in Tunisia.

    PubMed

    El Ayeb-Zakhama, Asma; Sakka-Rouis, Lamia; Bergaoui, Afifa; Flamini, Guido; Ben Jannet, Hichem; Harzallah-Skhiri, Fethia

    2015-04-01

    Acacia cyanophylla Lindl. (Fabaceae), synonym Acacia saligna (Labill.) H. L.Wendl., native to West Australia and naturalized in North Africa and South Europe, was introduced in Tunisia for rangeland rehabilitation, particularly in the semiarid zones. In addition, this evergreen tree represents a potential forage resource, particularly during periods of drought. A. cyanophylla is abundant in Tunisia and some other Mediterranean countries. The chemical composition of the essential oils obtained by hydrodistillation from different plant parts, viz., roots, stems, phyllodes, flowers, and pods (fully mature fruits without seeds), was characterized for the first time here. According to GC-FID and GC/MS analyses, the principal compound in the phyllode and flower oils was dodecanoic acid (4), representing 22.8 and 66.5% of the total oil, respectively. Phenylethyl salicylate (8; 34.9%), heptyl valerate (3; 17.3%), and nonadecane (36%) were the main compounds in the root, stem, and pod oils, respectively. The phyllode and flower oils were very similar, containing almost the same compounds. Nevertheless, the phyllode oil differed from the flower oil for its higher contents of hexahydrofarnesyl acetone (6), linalool (1), pentadecanal, α-terpineol, and benzyl benzoate (5) and its lower content of 4. Principal component and hierarchical cluster analyses separated the five essential oils into four groups, each characterized by its main constituents. Furthermore, the allelopathic activity of each oil was evaluated using lettuce (Lactuca sativa L.) as a plant model. The phyllode, flower, and pod oils exhibited a strong allelopathic activity against lettuce. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

  5. Chemical composition of French mimosa absolute oil.

    PubMed

    Perriot, Rodolphe; Breme, Katharina; Meierhenrich, Uwe J; Carenini, Elise; Ferrando, Georges; Baldovini, Nicolas

    2010-02-10

    Since decades mimosa (Acacia dealbata) absolute oil has been used in the flavor and perfume industry. Today, it finds an application in over 80 perfumes, and its worldwide industrial production is estimated five tons per year. Here we report on the chemical composition of French mimosa absolute oil. Straight-chain analogues from C6 to C26 with different functional groups (hydrocarbons, esters, aldehydes, diethyl acetals, alcohols, and ketones) were identified in the volatile fraction. Most of them are long-chain molecules: (Z)-heptadec-8-ene, heptadecane, nonadecane, and palmitic acid are the most abundant, and constituents such as 2-phenethyl alcohol, methyl anisate, and ethyl palmitate are present in smaller amounts. The heavier constituents were mainly triterpenoids such as lupenone and lupeol, which were identified as two of the main components. (Z)-Heptadec-8-ene, lupenone, and lupeol were quantified by GC-MS in SIM mode using external standards and represents 6%, 20%, and 7.8% (w/w) of the absolute oil. Moreover, odorant compounds were extracted by SPME and analyzed by GC-sniffing leading to the perception of 57 odorant zones, of which 37 compounds were identified by their odorant description, mass spectrum, retention index, and injection of the reference compound.

  6. Direct one-pot reductive amination of aldehydes with nitroarenes in a domino fashion: catalysis by gum-acacia-stabilized palladium nanoparticles.

    PubMed

    Sreedhar, B; Reddy, P Surendra; Devi, D Keerthi

    2009-11-20

    This note describes the direct reductive amination of carbonyl compounds with nitroarenes using gum acacia-palladium nanoparticles, employing molecular hydrogen as the reductant. This methodology is found to be applicable to both aliphatic and aromatic aldehydes and a wide range of nitroarenes. The operational simplicity and the mild reaction conditions add to the value of this method as a practical alternative to the reductive amination of carbonyl compounds.

  7. An Implementation Plan for NFS at NASA's NAS Facility

    NASA Technical Reports Server (NTRS)

    Lam, Terance L.; Kutler, Paul (Technical Monitor)

    1998-01-01

    This document discusses how NASA's NAS can benefit from the Sun Microsystems' Network File System (NFS). A case study is presented to demonstrate the effects of NFS on the NAS supercomputing environment. Potential problems are addressed and an implementation strategy is proposed.

  8. Can thinning of overstory trees and planting of native tree saplings increase the establishment of native trees in exotic acacia plantations in south china?

    Treesearch

    SF Yuan; H Ren; N Liu; J Wang; QF Guo

    2013-01-01

    Assessing the effect of thinning of overstorey trees and planting of native trees will be helpful to better understand the vegetation restoration. A stand conversion experiment was conducted in a 12-year-old Acacia auriculiformis plantation in 1996. Treatments were thinning and underplanting, underplanting, thinning, and control. Results showed that...

  9. Stable annual pattern of water use by Acacia tortilis in Sahelian Africa.

    PubMed

    Do, Frederic C; Rocheteau, Alain; Diagne, Amadou L; Goudiaby, Venceslas; Granier, André; Lhomme, Jean-Paul

    2008-01-01

    Water use by mature trees of Acacia tortilis (Forsk.) Hayne ssp. raddiana (Savi) Brenan var. raddiana growing in the northern Sahel was continuously recorded over 4 years. Water use was estimated from xylem sap flow measured by transient heat dissipation. Concurrently, cambial growth, canopy phenology, leaf water potential, climatic conditions and soil water availability (SWA) were monitored. In addition to the variation attributable to interannual variation in rainfall, SWA was increased by irrigation during one wet season. The wet season lasted from July to September, and annual rainfall ranged between 146 and 367 mm. The annual amount and pattern of tree water use were stable from year-to-year despite interannual and seasonal variations in SWA in the upper soil layers. Acacia tortilis transpired readily throughout the year, except for one month during the dry season when defoliation was at a maximum. Maximum water use of about 23 l (dm sapwood area)(-2) day(-1) was recorded at the end of the wet season. While trees retained foliage in the dry season, the decline in water use was modest at around 30%. Variation in predawn leaf water potential indicated that the trees were subject to soil water constraint. The rapid depletion of water in the uppermost soil layers after the wet season implies that there was extensive use of water from deep soil layers. The deep soil profile revealed (1) the existence of living roots at 25 m and (2) that the availability of soil water was low (-1.6 MPa) down to the water table at a depth of 31 m. However, transpiration was recorded at a predawn leaf water potential of -2.0 MPa, indicating that the trees used water from both intermediary soil layers and the water table. During the full canopy stage, mean values of whole-tree hydraulic conductance were similar in the wet and dry seasons. We propose that the stability of water use at the seasonal and annual scales resulted from a combination of features, including an extensive rooting

  10. An examination of the feasibility of using time-of-flight based non-destructive evaluation to assess the soundness of standing Acacia koa

    Treesearch

    Jan Wiedenbeck; Eini Lowell

    2011-01-01

    Koa (Acacia koa) trees are native to the islands of Hawaii but occur nowhere else in the world. It is the most important timber species for the manufacture of wood products in Hawaii and one of the most valuable species worldwide. Most koa trees harvested today are standing dead or are already on the ground (relic logs). Lumber recovery in milling...

  11. NAS infrastructure management system build 1.5 computer-human interface

    DOT National Transportation Integrated Search

    2001-01-01

    Human factors engineers from the National Airspace System (NAS) Human Factors Branch (ACT-530) of the Federal Aviation Administration William J. Hughes Technical Center conducted an evaluation of the NAS Infrastructure Management System (NIMS) Build ...

  12. Matrix Assisted Laser Desorption Ionization Mass Fingerprinting for Identification of Acacia Gum in Microsamples from Works of Art.

    PubMed

    Granzotto, Clara; Sutherland, Ken

    2017-03-07

    This paper reports an improved method for the identification of Acacia gum in cultural heritage samples using matrix assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) after enzymatic digestion of the polysaccharide component. The analytical strategy was optimized using a reference Acacia gum (gum arabic, sp. A. senegal) and provided an unambiguous MS profile of the gum, characterized by specific and recognized oligosaccharides, from as little as 0.1 μg of material. The enhanced experimental approach with reduced detection limit was successfully applied to the analysis of naturally aged (∼80 year) gum arabic samples, pure and mixed with lead white pigment, and allowed the detection of gum arabic in samples from a late painting (1949/1954) by Georges Braque in the collection of the Art Institute of Chicago. This first application of the technique to characterize microsamples from a painting, in conjunction with analyses by gas chromatography/mass spectrometry (GC/MS), provided important insights into Braque's unusual mixed paint media that are also helpful to inform appropriate conservation treatments for his works. The robustness of the analytical strategy due to the reproducibility of the gum MS profile, even in the presence of other organic and inorganic components, together with the minimal sample size required, demonstrate the value of this new MALDI-TOF MS method as an analytical tool for the identification of gum arabic in microsamples from museum artifacts.

  13. Controlled release of Doxycycline from gum acacia/poly(sodium acrylate) microparticles for oral drug delivery.

    PubMed

    Bajpai, S K; Jadaun, Mamta; Bajpai, M; Jyotishi, Pooja; Shah, Farhan Ferooz; Tiwari, Seema

    2017-11-01

    In the present work, Doxycycline loaded gum acacia (GA)/poly(sodium acrylate) (SA) hydrogels were prepared for the oral drug delivery of model drug Doxycycline. The hydrogels were characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR) scanning electron microscopy (SEM) and Zeta potential. The dynamic release of Doxycycline was investigated in the physiological fluids at 37°C. Various kinetic models such as Power function model, Schott model and Higuchi model were applied to interpret the release data. Schott model was found to be most fitted. The Doxycycline loaded hydrogels were tested for their antibacterial action against E. coli. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. A Method for Suppressing Line Overload Phenomena Using NAS Battery Systems

    NASA Astrophysics Data System (ADS)

    Ohtaka, Toshiya; Iwamoto, Shinichi

    In this paper, we pay attention to the superior operating control function and instantaneous discharging characteristics of NAS battery systems, and propose a method for determining installation planning and operating control schemes of NAS battery systems for suppressing line overload phenomena. In the stage of planning, a target contingency is identified, and an optimal allocation and capacity of NAS battery systems and an amount of generation changes are determined for the contingency. In the stage of operation, the control strategy of NAS battery system is determined. Simulations are carried out for verifying the validity of the proposed method using the IEEJ 1 machine V system model and an example 2 machine 16 bus system model.

  15. Anti-Hypertensive Effects of Acacia Polyphenol in Spontaneously Hypertensive Rats

    PubMed Central

    Ikarashi, Nobutomo; Toda, Takahiro; Hatakeyama, Yusuke; Kusunoki, Yoshiki; Kon, Risako; Mizukami, Nanaho; Kaneko, Miho; Ogawa, Sosuke; Sugiyama, Kiyoshi

    2018-01-01

    We have previously demonstrated that acacia polyphenol (AP) exerts strong anti-obesity, anti-diabetic, and anti-atopic dermatitis effects. In the present study, we investigated the anti-hypertensive effects of AP. Spontaneously hypertensive rats (SHR) with hypertension and control Wistar Kyoto rats (WKY) were used. WKY and SHR were fed AP-containing food or AP-free food (control group) ad libitum for 4 weeks, and their blood pressures were measured. After AP administration, both systolic and diastolic blood pressures were significantly lower in the SHR group than in the control group. There were no differences in the systolic or diastolic blood pressure of WKY between the AP group and the control group. Angiotensin-converting enzyme (ACE) activity, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression, and superoxide dismutase (SOD) activity in SHR kidneys were not altered by AP administration. Blood SOD activity in SHR was significantly higher in the AP group than in the control group. AP exerts anti-hypertensive effects on hypertension but has almost no effect on normal blood pressure. The anti-hypertensive effects of AP may be related to the anti-oxidative effects of increased blood SOD activity. PMID:29494506

  16. The NAS Alert System: A look at the first eight years

    USGS Publications Warehouse

    Fuller, Pamela L.; Neilson, Matt; Huge, Dane H.

    2013-01-01

    The U.S. Geological Survey's Nonindigenous Aquatic Species (NAS) database program (http://nas.er.usgs.gov) tracks the distribution of introduced aquatic organisms across the United States. Awareness of, and timely response to, novel species introductions by those involved in nonindigenous aquatic species management and research requires a framework for rapid dissemination of occurrence data as it is incorporated into the NAS database. In May 2004, the NAS program developed an alert system to notify registered users of new introductions as part of a national early detection/rapid response system. This article summarizes information on system users and dispatched alerts from the system's inception through the end of 2011. The NAS alert system has registered over 1,700 users, with approximately 800 current subscribers. A total of 1,189 alerts had been transmitted through 2011. More alerts were sent for Florida (134 alerts) than for any other state. Fishes comprise the largest taxonomic group of alerts (440), with mollusks, plants, and crustaceans each containing over 100 alerts. Most alerts were for organisms that were intentionally released (414 alerts), with shipping, escape from captivity, and hitchhiking also representing major vectors. To explore the archive of sent alerts and to register, the search and signup page for the alert system can be found online at http://nas.er.usgs.gov/AlertSystem/default.aspx.

  17. The effect of acacia gum and a water-soluble dietary fiber mixture on blood lipids in humans.

    PubMed

    Jensen, C D; Spiller, G A; Gates, J E; Miller, A F; Whittam, J H

    1993-04-01

    Water-soluble dietary fibers (WSDF) are generally thought to lower cholesterol. This study compared the cholesterol-lowering effects of a medium viscosity WSDF mixture (psyllium, pectin, guar gum and locust bean gum) with an equal amount of WSDF from acacia gum, which has a lower viscosity. Hypercholesterolemic males (n = 13) and females (n = 16) were randomly assigned to one of two WSDF treatments provided in a low-calorie powder form for mixing into beverages (< 4 kcal/serving). Subjects were instructed to mix powders into their usual beverages and to consume them three times daily (5 g WSDF/serving) for 4 weeks while consuming their typical fat-modified diets. Exercise and body weights were also held constant. The WSDF mixture yielded a 10% decrease in plasma total cholesterol (from 251 +/- 20 to 225 +/- 19 mg/dL; p < 0.01), and a 14% reduction in low-density lipoprotein cholesterol (from 167 +/- 14 to 144 +/- 14 mg/dL; p < 0.001). No significant changes in plasma high-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol or triglycerides were observed. In contrast, the acacia gum-treated group showed no change in any plasma lipid parameters. The WSDF treatments did not produce significant changes in mean dietary intakes within or between treatment groups. These data support previous findings that a diet rich in select WSDF can be a useful cholesterol-lowering adjunct to a fat-modified diet, but that caution should be exercised in ascribing cholesterol-lowering efficacy to dietary fibers based solely on their WSDF classification. Finally, WSDF viscosity is a potential cholesterol-lowering factor to be explored further.

  18. NAS Panel endorses science center concept

    NASA Astrophysics Data System (ADS)

    Science and technology centers, as proposed by President Ronald Reagan in his January 1987 State of the Union message, could make “significant contributions to science and to the nation's economic competitiveness,” according to a new report by a National Academy of Sciences (NAS) panel. What will be necessary to realize these contributions, the panel cautioned, are proper management, adequate resources, and, “above all, the selection of programs for which the centers are the most effective form of organization.”NSF plans to support science and technology centers, beginning October 1, 1988, which is the start of fiscal year 1988. NSF requested guidance from the NAS panel in implementing the program. Although other government agencies will participate in the program, NSF will play the primary role.

  19. UAS-NAS Flight Test Series 3: Test Environment Report

    NASA Technical Reports Server (NTRS)

    Hoang, Ty; Murphy, Jim; Otto, Neil

    2016-01-01

    The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration in the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability (SSI), Human Systems Integration (HSI), and Communications (Comm), and Certification to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Detect and Avoid (DAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project is conducting a series of human-in-the-loop (HITL) and flight test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity, and

  20. The NAS kernel benchmark program

    NASA Technical Reports Server (NTRS)

    Bailey, D. H.; Barton, J. T.

    1985-01-01

    A collection of benchmark test kernels that measure supercomputer performance has been developed for the use of the NAS (Numerical Aerodynamic Simulation) program at the NASA Ames Research Center. This benchmark program is described in detail and the specific ground rules are given for running the program as a performance test.

  1. Shifts in the bacterial community composition along deep soil profiles in monospecific and mixed stands of Eucalyptus grandis and Acacia mangium.

    PubMed

    Pereira, Arthur Prudêncio de Araujo; Andrade, Pedro Avelino Maia de; Bini, Daniel; Durrer, Ademir; Robin, Agnès; Bouillet, Jean Pierre; Andreote, Fernando Dini; Cardoso, Elke Jurandy Bran Nogueira

    2017-01-01

    Our knowledge of the rhizosphere bacterial communities in deep soils and the role of Eucalyptus and Acacia on the structure of these communities remains very limited. In this study, we targeted the bacterial community along a depth profile (0 to 800 cm) and compared community structure in monospecific or mixed plantations of Acacia mangium and Eucalyptus grandis. We applied quantitative PCR (qPCR) and sequence the V6 region of the 16S rRNA gene to characterize composition of bacterial communities. We identified a decrease in bacterial abundance with soil depth, and differences in community patterns between monospecific and mixed cultivations. Sequence analysis indicated a prevalent effect of soil depth on bacterial communities in the mixed plant cultivation system, and a remarkable differentiation of bacterial communities in areas solely cultivated with Eucalyptus. The groups most influenced by soil depth were Proteobacteria and Acidobacteria (more frequent in samples between 0 and 300 cm). The predominant bacterial groups differentially displayed in the monospecific stands of Eucalyptus were Firmicutes and Proteobacteria. Our results suggest that the addition of an N2-fixing tree in a monospecific cultivation system modulates bacterial community composition even at a great depth. We conclude that co-cultivation systems may represent a key strategy to improve soil resources and to establish more sustainable cultivation of Eucalyptus in Brazil.

  2. Shifts in the bacterial community composition along deep soil profiles in monospecific and mixed stands of Eucalyptus grandis and Acacia mangium

    PubMed Central

    de Andrade, Pedro Avelino Maia; Bini, Daniel; Durrer, Ademir; Robin, Agnès; Bouillet, Jean Pierre; Andreote, Fernando Dini; Cardoso, Elke Jurandy Bran Nogueira

    2017-01-01

    Our knowledge of the rhizosphere bacterial communities in deep soils and the role of Eucalyptus and Acacia on the structure of these communities remains very limited. In this study, we targeted the bacterial community along a depth profile (0 to 800 cm) and compared community structure in monospecific or mixed plantations of Acacia mangium and Eucalyptus grandis. We applied quantitative PCR (qPCR) and sequence the V6 region of the 16S rRNA gene to characterize composition of bacterial communities. We identified a decrease in bacterial abundance with soil depth, and differences in community patterns between monospecific and mixed cultivations. Sequence analysis indicated a prevalent effect of soil depth on bacterial communities in the mixed plant cultivation system, and a remarkable differentiation of bacterial communities in areas solely cultivated with Eucalyptus. The groups most influenced by soil depth were Proteobacteria and Acidobacteria (more frequent in samples between 0 and 300 cm). The predominant bacterial groups differentially displayed in the monospecific stands of Eucalyptus were Firmicutes and Proteobacteria. Our results suggest that the addition of an N2-fixing tree in a monospecific cultivation system modulates bacterial community composition even at a great depth. We conclude that co-cultivation systems may represent a key strategy to improve soil resources and to establish more sustainable cultivation of Eucalyptus in Brazil. PMID:28686690

  3. National Air Space (NAS) Data Exchange Environment Through 2060

    NASA Technical Reports Server (NTRS)

    Roy, Aloke

    2015-01-01

    NASA's NextGen Concepts and Technology Development (CTD) Project focuses on capabilities to improve safety, capacity and efficiency of the National Air Space (NAS). In order to achieve those objectives, NASA sought industry-Government partnerships to research and identify solutions for traffic flow management, dynamic airspace configuration, separation assurance, super density operations, airport surface operations and similar forward-looking air-traffic modernization (ATM) concepts. Data exchanges over NAS being the key enabler for most of these ATM concepts, the Sub-Topic area 3 of the CTD project sought to identify technology candidates that can satisfy air-to-air and air/ground communications needs of the NAS in the year 2060 timeframe. Honeywell, under a two-year contract with NASA, is working on this communications technology research initiative. This report summarizes Honeywell's research conducted during the second year of the study task.

  4. NAS Technical Summaries, March 1993 - February 1994

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefitting other supercomputer centers in government and industry. The 1993-94 operational year concluded with 448 high-speed processor projects and 95 parallel projects representing NASA, the Department of Defense, other government agencies, private industry, and universities. This document provides a glimpse at some of the significant scientific results for the year.

  5. UAS-NAS Integrated Human in the Loop: Test Environment Report

    NASA Technical Reports Server (NTRS)

    Murphy, Jim; Otto, Neil; Jovic, Srba

    2015-01-01

    The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration in the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability (SSI), Human Systems Integration (HSI), and Communication to support reducing the barriers of UAS access to the NAS. This research was broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Sense and Avoid (SAA) performance standards, command and control performance standards, and human systems integration. The focus of the Test Infrastructure theme was to enable development and validation of airspace integration procedures and performance standards, including the execution of integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project developed an adaptable, scalable, and schedulable relevant test environment incorporating live, virtual, and constructive elements capable of validating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project planned to conduct three integrated events: a Human-in-the-Loop simulation and two Flight Test series that integrated key concepts, technologies and/or procedures in a relevant air traffic environment. Each of

  6. Hybrid Network Architectures for the Next Generation NAS

    NASA Technical Reports Server (NTRS)

    Madubata, Christian

    2003-01-01

    To meet the needs of the 21st Century NAS, an integrated, network-centric infrastructure is essential that is characterized by secure, high bandwidth, digital communication systems that support precision navigation capable of reducing position errors for all aircraft to within a few meters. This system will also require precision surveillance systems capable of accurately locating all aircraft, and automatically detecting any deviations from an approved path within seconds and be able to deliver high resolution weather forecasts - critical to create 4- dimensional (space and time) profiles for up to 6 hours for all atmospheric conditions affecting aviation, including wake vortices. The 21st Century NAS will be characterized by highly accurate digital data bases depicting terrain, obstacle, and airport information no matter what visibility conditions exist. This research task will be to perform a high-level requirements analysis of the applications, information and services required by the next generation National Airspace System. The investigation and analysis is expected to lead to the development and design of several national network-centric communications architectures that would be capable of supporting the Next Generation NAS.

  7. SMART NAS Test Bed Overview

    NASA Technical Reports Server (NTRS)

    Palopo, Kee

    2016-01-01

    These slides presents an overview of SMART NAS Test Bed. The test bed is envisioned to be connected to operational systems and to allow a new concept and technology to be evaluated in its realistic environment. Its role as an accelerator of concepts and technologies development, its use-case-driven development approach, and its state are presented.

  8. NAS Applications and Advanced Algorithms

    NASA Technical Reports Server (NTRS)

    Bailey, David H.; Biswas, Rupak; VanDerWijngaart, Rob; Kutler, Paul (Technical Monitor)

    1997-01-01

    This paper examines the applications most commonly run on the supercomputers at the Numerical Aerospace Simulation (NAS) facility. It analyzes the extent to which such applications are fundamentally oriented to vector computers, and whether or not they can be efficiently implemented on hierarchical memory machines, such as systems with cache memories and highly parallel, distributed memory systems.

  9. NASA Advanced Supercomputing (NAS) User Services Group

    NASA Technical Reports Server (NTRS)

    Pandori, John; Hamilton, Chris; Niggley, C. E.; Parks, John W. (Technical Monitor)

    2002-01-01

    This viewgraph presentation provides an overview of NAS (NASA Advanced Supercomputing), its goals, and its mainframe computer assets. Also covered are its functions, including systems monitoring and technical support.

  10. Anti-Obesity and Anti-Diabetic Effects of Acacia Polyphenol in Obese Diabetic KKAy Mice Fed High-Fat Diet

    PubMed Central

    Ikarashi, Nobutomo; Toda, Takahiro; Okaniwa, Takehiro; Ito, Kiyomi; Ochiai, Wataru; Sugiyama, Kiyoshi

    2011-01-01

    Acacia polyphenol (AP) extracted from the bark of the black wattle tree (Acacia meansii) is rich in unique catechin-like flavan-3-ols, such as robinetinidol and fisetinidol. The present study investigated the anti-obesity/anti-diabetic effects of AP using obese diabetic KKAy mice. KKAy mice received either normal diet, high-fat diet or high-fat diet with additional AP for 7 weeks. After the end of administration, body weight, plasma glucose and insulin were measured. Furthermore, mRNA and protein expression of obesity/diabetic suppression-related genes were measured in skeletal muscle, liver and white adipose tissue. As a result, compared to the high-fat diet group, increases in body weight, plasma glucose and insulin were significantly suppressed for AP groups. Furthermore, compared to the high-fat diet group, mRNA expression of energy expenditure-related genes (PPARα, PPARδ, CPT1, ACO and UCP3) was significantly higher for AP groups in skeletal muscle. Protein expressions of CPT1, ACO and UCP3 for AP groups were also significantly higher when compared to the high-fat diet group. Moreover, AP lowered the expression of fat acid synthesis-related genes (SREBP-1c, ACC and FAS) in the liver. AP also increased mRNA expression of adiponectin and decreased expression of TNF-α in white adipose tissue. In conclusion, the anti-obesity actions of AP are considered attributable to increased expression of energy expenditure-related genes in skeletal muscle, and decreased fatty acid synthesis and fat intake in the liver. These results suggest that AP is expected to be a useful plant extract for alleviating metabolic syndrome. PMID:21799697

  11. Nutritional benefits of Crematogaster mimosae ants and Acacia drepanolobium gum for patas monkeys and vervets in Laikipia, Kenya.

    PubMed

    Isbell, Lynne A; Rothman, Jessica M; Young, Peter J; Rudolph, Kathleen

    2013-02-01

    Patas monkeys (Erythrocebus patas) are midsized primates that feed extensively on the gum of Acacia drepanolobium and the ants are housed in swollen thorns of this Acacia. Their diet resembles that expected more of smaller bodied primates. Patas monkeys are also more like smaller bodied primates in reproducing at high rates. We sought to better understand the convergence of patas monkeys with smaller bodied primates by comparing their feeding behavior on ants and gum with that of closely related, sympatric vervets (Chlorocebus pygerythrus), and analyzing the nutrient content of the gum of A. drepanolobium and of Crematogaster mimosae, the most common ant species eaten by patas monkeys in Laikipia, Kenya. All occurrences of feeding and moving during focal animal sampling revealed that 1) patas monkeys seek A. drepanolobium gum but vervets avoid it; 2) both species open swollen thorns most often in the morning when antsare less active; 3) patas monkeys continually feed onswollen thorns and gum while moving quickly throughout the day, whereas vervets reduce their consumption of these items and their travel rate at mid-day, and; 4) vervets eat young swollen thorns at a higher rate than patas monkeys. Patas monkeys are able to spend little time acquiring substantial amounts of energy, protein, and minerals from A. drepanolobium gum and C. mimosae ants each day. These findings, when coupled with evidence of causes of infant and adult female mortality, suggest that reproductive success of female patas monkeys is more immediately affected by illness, disease, interactions between adults and infants, and access to water than by food. Copyright © 2012 Wiley Periodicals, Inc.

  12. In-Vitro, Anti-Bacterial Activities of Aqueous Extracts of Acacia catechu (L.F.)Willd, Castanea sativa, Ephedra sinica stapf and shilajita mumiyo Against Gram Positive and Gram Negative Bacteria

    PubMed Central

    Dashtdar, Mehrab; Dashtdar, Mohammad Reza; Dashtdar, Babak; shirazi, Mohammad khabaz; Khan, Saeed Ahmad

    2013-01-01

    Objective: Evaluations of the in-vitro anti-bacterial activities of aqueous extracts of Acacia catechu (L.F.)Willd, Castanea sativa, Ephedra sinica stapf and Shilajita mumiyo against gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumonia) and gram-negative bacteria (Escherichia coli, klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa) are reasonable since these ethnomedicinal plants have been used in Persian folk medicine for treating skin diseases, venereal diseases, respiratory problems and nervous disorders for ages. Methods: The well diffusion method (KB testing) with a concentration of 250 μg/disc was used for evaluating the minimal inhibitory concentrations (MIC). Maximum synergistic effects of different combinations of components were also observed. Results: A particular combination of Acacia catechu (L.F.) Willd, Castanea sativa, Ephedra sinica stapf and shilajita mumiyo extracts possesses an outstanding anti-bacterial activity. It's inhibiting effect on microorganisms is significant when compared to the control group (P< 0.05). Staphylococcus aureus was the most sensitive microorganism. The highest antibacterial activity against gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumonia) or gram-negative bacteria (Escherichia coli, Klebsiella pneumonia, Proteus mirabilis and Pseudomonas aeruginosa) was exerted by formula number 2 (Table1). Conclusion: The results reveal the presence of antibacterial activities of Acacia catechu, Castanea sativa husk, Ephedra sp. and Mumiyo against gram-positive and gram-negative bacteria. Synergistic effects in a combined formula, especially in formula number 2 (ASLANⓇ) can lead to potential sources of new antiseptic agents for treatment of acute or chronic skin ulcers. These results considering the significant antibacterial effect of the present formulation, support ethno-pharmacological uses against diarrheal and venereal diseases and demonstrate use of these plants to treat

  13. First report of the root-rot pathogen, Armillaria gallica, on koa (Acacia koa) and 'Ohi'a lehua (Metrosideros polymorpha) on the island of Kaua'i, Hawai'i

    Treesearch

    M. -S. Kim; N. R. Fonseca; R. D. Hauff; P. G. Cannon; John Hanna; Ned Klopfenstein

    2017-01-01

    Koa (Acacia koa) and 'ohi'a lehua (Metrosideros polymorpha) are the two most dominant native tree species in Hawai‘i. Their populations are continuously decreasing, primarily because of forest disease (Dudley et al. 2007; Keith et al. 2015) and other biotic disturbances. In April 2015, Armillaria rhizomorphs were collected from woody hosts on the...

  14. UAS Integration in the NAS: Detect and Avoid

    NASA Technical Reports Server (NTRS)

    Shively, Jay

    2018-01-01

    This presentation will cover the structure of the unmanned aircraft systems (UAS) integration into the national airspace system (NAS) project (UAS-NAS Project). The talk also details the motivation of the project to help develop standards for a detect-and-avoid (DAA) system, which is required in order to comply with requirements in manned aviation to see-and-avoid other traffic so as to maintain well clear. The presentation covers accomplishments reached by the project in Phase 1 of the research, and touches on the work to be done in Phase 2. The discussion ends with examples of the display work developed as a result of the Phase 1 research.

  15. Response of native soil microbial functions to the controlled mycorrhization of an exotic tree legume, Acacia holosericea in a Sahelian ecosystem.

    PubMed

    Bilgo, Ablasse; Sangare, Sheikh K; Thioulouse, Jean; Prin, Yves; Hien, Victor; Galiana, Antoine; Baudoin, Ezekeil; Hafidi, Mohamed; Bâ, Amadou M; Duponnois, Robin

    2012-04-01

    Fifty years of overexploitation have disturbed most forests within Sahelian areas. Exotic fast growing trees (i.e., Australian Acacia species) have subsequently been introduced for soil improvement and fuelwood production purposes. Additionally, rhizobial or mycorrhizal symbioses have sometimes been favored by means of controlled inoculations to increase the performance of these exotic trees in such arid and semiarid zones. Large-scale anthropogenic introduction of exotic plants could also threaten the native biodiversity and ecosystem resilience. We carried out an experimental reforestation in Burkina Faso in order to study the effects of Acacia holosericea mycorrhizal inoculation on the soil nutrient content, microbial soil functionalities and mycorrhizal soil potential. Treatments consisted of uninoculated A. holosericea, preplanting fertilizer application and arbuscular mycorrhizal inoculation with Glomus intraradices. Our results showed that (i) arbuscular mycorrhizal (AM) inoculation and prefertilizer application significantly improved A. holosericea growth after 4 years of plantation and (ii) the introduction of A. holosericea trees significantly modified soil microbial functions. The results clearly showed that the use of exotic tree legume species should be directly responsible for important changes in soil microbiota with great disturbances in essential functions driven by microbial communities (e.g., catabolic diversity and C cycling, phosphatase activity and P availability). They also highlighted the importance of AM symbiosis in the functioning of soils and forest plantation performances. The AM effect on soil functions was significantly correlated with the enhanced mycorrhizal soil potential recorded in the AM inoculation treatment. © Springer-Verlag 2011

  16. [Methods in neonatal abstinence syndrome (NAS): results of a nationwide survey in Austria].

    PubMed

    Bauchinger, S; Sapetschnig, I; Danda, M; Sommer, C; Resch, B; Urlesberger, B; Raith, W

    2015-08-01

    Neonatal abstinence syndrome (NAS) occurs in neonates whose mothers have taken addictive drugs or were under substitution therapy during pregnancy. Incidence numbers of NAS are on the rise globally, even in Austria NAS is not rare anymore. The aim of our survey was to reveal the status quo of dealing with NAS in Austria. A questionnaire was sent to 20 neonatology departments all over Austria, items included questions on scoring, therapy, breast-feeding and follow-up procedures. The response rate was 95%, of which 94.7% had written guidelines concerning NAS. The median number of children being treated per year for NAS was 4. Finnegan scoring system is used in 100% of the responding departments. Morphine is being used most often, in opiate abuse (100%) as well as in multiple substance abuse (44.4%). The most frequent forms of morphine preparation are morphine and diluted tincture of opium. Frequency as well as dosage of medication vary broadly. 61.1% of the departments supported breast-feeding, regulations concerned participation in a substitution programme and general contraindications (HIV, HCV, HBV). Our results revealed that there is a big west-east gradient in patients being treated per year. NAS is not a rare entity anymore in Austria (up to 50 cases per year in Vienna). Our survey showed that most neonatology departments in Austria treat their patients following written guidelines. Although all of them base these guidelines on international recommendations there is no national consensus. © Georg Thieme Verlag KG Stuttgart · New York.

  17. (GaIn)(NAs) growth using di-tertiary-butyl-arsano-amine (DTBAA)

    NASA Astrophysics Data System (ADS)

    Sterzer, E.; Ringler, B.; Nattermann, L.; Beyer, A.; von Hänisch, C.; Stolz, W.; Volz, K.

    2017-06-01

    III/V semiconductors containing small amounts of Nitrogen (N) are very interesting for a variety of optoelectronic applications. Unfortunately, the conventionally used N precursor 1,1-dimethylhydrazine (UDMHy) has an extremely low N incorporation efficiency in GaAs when grown using metal organic vapor phase epitaxy. Alloying Ga(NAs) with Indium (In) even leads to an exponential reduction of N incorporation. The huge amount of UDMHy in turn changes drastically the growth conditions. Furthermore, the application of this material is still hampered by the large carbon incorporation, most probably originating from the metal organic precursors. Hence, novel precursors for dilute nitride growth are needed. This paper will show (GaIn)(NAs) growth studies with the novel precursor di-tertiary-butyl-arsano-amine in combination with tri-ethyl-gallium and tri-methyl-indium. We show an extremely high N incorporation efficiency in the In containing (GaIn)(NAs). The (GaIn)(NAs) samples investigated in this study have been examined using high resolution X-Ray diffraction, room temperature photoluminescence and atomic force microscope measurements as well as secondary ion mass spectrometry.

  18. Security Controls Hurt Research, NAS Warns.

    ERIC Educational Resources Information Center

    Kolata, Gina

    1982-01-01

    A National Academy of Sciences (NAS) report found no evidence that leaks of technical information from universities or other research centers have damaged national security. However, in areas where control is warranted, decisions should be based on criteria. These criteria and issues related to security control and technological transfer are…

  19. Low temperature grown GaNAsSb: A promising material for photoconductive switch application

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

    Tan, K. H.; Yoon, S. F.; Wicaksono, S.

    2013-09-09

    We report a photoconductive switch using low temperature grown GaNAsSb as the active material. The GaNAsSb layer was grown at 200 °C by molecular beam epitaxy in conjunction with a radio frequency plasma-assisted nitrogen source and a valved antimony cracker source. The low temperature growth of the GaNAsSb layer increased the dark resistivity of the switch and shortened the carrier lifetime. The switch exhibited a dark resistivity of 10{sup 7} Ω cm, a photo-absorption of up to 2.1 μm, and a carrier lifetime of ∼1.3 ps. These results strongly support the suitability of low temperature grown GaNAsSb in the photoconductivemore » switch application.« less

  20. Positive and negative effects of grass, cattle, and wild herbivores on Acacia saplings in an East African savanna.

    PubMed

    Riginos, Corinna; Young, Truman P

    2007-10-01

    Plant-plant interactions can be a complex mixture of positive and negative interactions, with the net outcome depending on abiotic and community contexts. In savanna systems, the effects of large herbivores on tree-grass interactions have rarely been studied experimentally, though these herbivores are major players in these systems. In African savannas, trees often become more abundant under heavy cattle grazing but less abundant in wildlife preserves. Woody encroachment where cattle have replaced wild herbivores may be caused by a shift in the competitive balance between trees and grasses. Here we report the results of an experiment designed to quantify the positive, negative, and net effects of grasses, wild herbivores, and cattle on Acacia saplings in a Kenyan savanna. Acacia drepanolobium saplings under four long-term herbivore regimes (wild herbivores, cattle, cattle + wild herbivores, and no large herbivores) were cleared of surrounding grass or left with the surrounding grass intact. After two years, grass-removal saplings exhibited 86% more browse damage than control saplings, suggesting that grass benefited saplings by protecting them from herbivory. However, the negative effect of grass on saplings was far greater; grass-removal trees accrued more than twice the total stem length of control trees. Where wild herbivores were present, saplings were browsed more and produced more new stem growth. Thus, the net effect of wild herbivores was positive, possibly due to the indirect effects of lower competitor tree density in areas accessible to elephants. Additionally, colonization of saplings by symbiotic ants tracked growth patterns, and colonized saplings experienced lower rates of browse damage. These results suggest that savanna tree growth and woody encroachment cannot be predicted by grass cover or herbivore type alone. Rather, tree growth appears to depend on a variety of factors that may be acting together or antagonistically at different stages of the

  1. Six Years of Parallel Computing at NAS (1987 - 1993): What Have we Learned?

    NASA Technical Reports Server (NTRS)

    Simon, Horst D.; Cooper, D. M. (Technical Monitor)

    1994-01-01

    In the fall of 1987 the age of parallelism at NAS began with the installation of a 32K processor CM-2 from Thinking Machines. In 1987 this was described as an "experiment" in parallel processing. In the six years since, NAS acquired a series of parallel machines, and conducted an active research and development effort focused on the use of highly parallel machines for applications in the computational aerosciences. In this time period parallel processing for scientific applications evolved from a fringe research topic into the one of main activities at NAS. In this presentation I will review the history of parallel computing at NAS in the context of the major progress, which has been made in the field in general. I will attempt to summarize the lessons we have learned so far, and the contributions NAS has made to the state of the art. Based on these insights I will comment on the current state of parallel computing (including the HPCC effort) and try to predict some trends for the next six years.

  2. Effects of perchlorate on growth of four wetland plants and its accumulation in plant tissues.

    PubMed

    He, Hongzhi; Gao, Haishuo; Chen, Guikui; Li, Huashou; Lin, Hai; Shu, Zhenzhen

    2013-10-01

    Perchlorate contamination in water is of concern because of uncertainties about toxicity and health effects, impact on ecosystems, and possible indirect exposure pathways to humans. Therefore, it is very important to investigate the ecotoxicology of perchlorate and to screen plant species for phytoremediation. Effects of perchlorate (20, 200, and 500 mg/L) on the growth of four wetland plants (Eichhornia crassipes, Acorus calamus L., Thalia dealbata, and Canna indica) as well as its accumulation in different plant tissues were investigated through water culture experiments. Twenty milligrams per liter of perchlorate had no significant effects on height, root length, aboveground part weight, root weight, and oxidizing power of roots of four plants, except A. calamus, and increasing concentrations of perchlorate showed that out of the four wetland plants, only A. calamus had a significant (p<0.05) dose-dependent decrease in these parameters. When treated with 500 mg/L perchlorate, these parameters and chlorophyll content in the leaf of plants showed significant decline contrasted to control groups, except the root length of E. crassipes and C. indica. The order of inhibition rates of perchlorate on root length, aboveground part weight and root weight, and oxidizing power of roots was: A. calamus > C. indica > T. dealbata > E. crassipes and on chlorophyll content in the leaf it was: A. calamus > T. dealbata > C. indica > E. crassipes. The higher the concentration of perchlorate used, the higher the amount of perchlorate accumulation in plants. Perchlorate accumulation in aboveground tissues was much higher than that in underground tissues and leaf was the main tissue for perchlorate accumulation. The order of perchlorate accumulation content and the bioconcentration factor in leaf of four plants was: E. crassipes > C. indica > T. dealbata > A. calamus. Therefore, E. crassipes might be an ideal plant with high tolerance ability and accumulation ability for constructing

  3. Quinonoid constituents as contact sensitisers in Australian blackwood (Acacia melanoxylon RBR).

    PubMed Central

    Hausen, B M; Schmalle, H

    1981-01-01

    Australian blackwood (Acacia melanoxylon RBR) is a valuable commercial timber that since 1925 has been incriminated as being injurious to health. In addition to toxic effects numerous cases of allergic contact dermatitis and bronchial asthma have been observed in woodworkers. Several constituents have been identified in recent years, but none of them could be considered as aetiological factors. Sensitizing experiments performed with blackwood heartwood extracts corroborated the described sensitising properties. Chemical studies showed the occurrence of two or possibly three quinones that produced positive skin responses in the sensitised guinea pigs. The main contact allergens were isolated and identified by x-ray analysis. The first, a yellow quinone, was identified as 2,6-dimethoxy-1,4-benzoquinone while the second, a red quinone, has the structure of 6-methoxy-2-methyl-3,5-dihydrobenzofurano-4,7-dion and was named acamelin. Whereas 2, 6-dimethoxy-p-benzoquinone is already known from natural sources, acamelin is new and belongs to the rate group of naturally occurring furanoquinones. Though the obtained sensitising capacity of A melanoxylon RBR in respect of its quinones is not high, it should be considered as a possible source of allergic contact dermatitis, especially as greater amounts of Australian blackwood may enter European countries in the near future. PMID:7236533

  4. Applications Performance on NAS Intel Paragon XP/S - 15#

    NASA Technical Reports Server (NTRS)

    Saini, Subhash; Simon, Horst D.; Copper, D. M. (Technical Monitor)

    1994-01-01

    The Numerical Aerodynamic Simulation (NAS) Systems Division received an Intel Touchstone Sigma prototype model Paragon XP/S- 15 in February, 1993. The i860 XP microprocessor with an integrated floating point unit and operating in dual -instruction mode gives peak performance of 75 million floating point operations (NIFLOPS) per second for 64 bit floating point arithmetic. It is used in the Paragon XP/S-15 which has been installed at NAS, NASA Ames Research Center. The NAS Paragon has 208 nodes and its peak performance is 15.6 GFLOPS. Here, we will report on early experience using the Paragon XP/S- 15. We have tested its performance using both kernels and applications of interest to NAS. We have measured the performance of BLAS 1, 2 and 3 both assembly-coded and Fortran coded on NAS Paragon XP/S- 15. Furthermore, we have investigated the performance of a single node one-dimensional FFT, a distributed two-dimensional FFT and a distributed three-dimensional FFT Finally, we measured the performance of NAS Parallel Benchmarks (NPB) on the Paragon and compare it with the performance obtained on other highly parallel machines, such as CM-5, CRAY T3D, IBM SP I, etc. In particular, we investigated the following issues, which can strongly affect the performance of the Paragon: a. Impact of the operating system: Intel currently uses as a default an operating system OSF/1 AD from the Open Software Foundation. The paging of Open Software Foundation (OSF) server at 22 MB to make more memory available for the application degrades the performance. We found that when the limit of 26 NIB per node out of 32 MB available is reached, the application is paged out of main memory using virtual memory. When the application starts paging, the performance is considerably reduced. We found that dynamic memory allocation can help applications performance under certain circumstances. b. Impact of data cache on the i860/XP: We measured the performance of the BLAS both assembly coded and Fortran

  5. Pharmacists' and prescribers' neonatal abstinence syndrome (NAS) prevention behaviors: a preliminary analysis.

    PubMed

    Hagemeier, Nicholas E; Click, Ivy A; Flippin, Heather; Gilliam, Holly; Ross, Alexandra; Basden, Jeri Ann; Carico, Ronald

    2018-02-01

    Background Maternal opioid use and neonatal abstinence syndrome (NAS) incidence have increased markedly in the US in recent years. Objectives (1) To assess prescribers' and community pharmacists' guideline-based NAS prevention behaviors; (2) to describe providers' perceptions of contraceptive appropriateness in female patients of childbearing age. Method Cross-sectional study of 100 randomly selected primary care physicians, 100 prescribers authorized to engage in in-office treatment of opioid use disorders with buprenorphine, 100 pain management clinic directors, and 100 community pharmacists in Tennessee (N = 400 providers total) to evaluate self-reported engagement in 15 NAS prevention behaviors and perceived appropriateness of 8 contraceptive methods in opioid using women of childbearing age. Results An overall response rate of 17.5% was obtained. Pain clinic directors reported the most engagement in NAS prevention, engaging 80% or more of female patients of childbearing age prescribed an opioid in 11 prevention behaviors, followed by buprenorphine prescribers (8 behaviors), primary care physicians (5 behaviors), and community pharmacists (2 behaviors). Pain clinic directors, primary care physicians, and community pharmacists perceived oral contraceptive pills and patches to be as appropriate as long-acting, reversible forms of contraception (e.g., implants, injectable depots, intrauterine devices). Conclusion Provider engagement in behaviors that could prevent NAS is variable. Interventions should be implemented that equip providers to engage patients in conversations about long-acting, reversible contraception.

  6. High-throughput prediction of Acacia and eucalypt lignin syringyl/guaiacyl content using FT-Raman spectroscopy and partial least squares modeling

    DOE PAGES

    Lupoi, Jason S.; Healey, Adam; Singh, Seema; ...

    2015-01-16

    High-throughput techniques are necessary to efficiently screen potential lignocellulosic feedstocks for the production of renewable fuels, chemicals, and bio-based materials, thereby reducing experimental time and expense while supplanting tedious, destructive methods. The ratio of lignin syringyl (S) to guaiacyl (G) monomers has been routinely quantified as a way to probe biomass recalcitrance. Mid-infrared and Raman spectroscopy have been demonstrated to produce robust partial least squares models for the prediction of lignin S/G ratios in a diverse group of Acacia and eucalypt trees. The most accurate Raman model has now been used to predict the S/G ratio from 269 unknown Acaciamore » and eucalypt feedstocks. This study demonstrates the application of a partial least squares model composed of Raman spectral data and lignin S/G ratios measured using pyrolysis/molecular beam mass spectrometry (pyMBMS) for the prediction of S/G ratios in an unknown data set. The predicted S/G ratios calculated by the model were averaged according to plant species, and the means were not found to differ from the pyMBMS ratios when evaluating the mean values of each method within the 95 % confidence interval. Pairwise comparisons within each data set were employed to assess statistical differences between each biomass species. While some pairwise appraisals failed to differentiate between species, Acacias, in both data sets, clearly display significant differences in their S/G composition which distinguish them from eucalypts. In conclusion, this research shows the power of using Raman spectroscopy to supplant tedious, destructive methods for the evaluation of the lignin S/G ratio of diverse plant biomass materials.« less

  7. The NAS parallel benchmarks

    NASA Technical Reports Server (NTRS)

    Bailey, D. H.; Barszcz, E.; Barton, J. T.; Carter, R. L.; Lasinski, T. A.; Browning, D. S.; Dagum, L.; Fatoohi, R. A.; Frederickson, P. O.; Schreiber, R. S.

    1991-01-01

    A new set of benchmarks has been developed for the performance evaluation of highly parallel supercomputers in the framework of the NASA Ames Numerical Aerodynamic Simulation (NAS) Program. These consist of five 'parallel kernel' benchmarks and three 'simulated application' benchmarks. Together they mimic the computation and data movement characteristics of large-scale computational fluid dynamics applications. The principal distinguishing feature of these benchmarks is their 'pencil and paper' specification-all details of these benchmarks are specified only algorithmically. In this way many of the difficulties associated with conventional benchmarking approaches on highly parallel systems are avoided.

  8. Decomposition of lignin and holocellulose on Acacia mangium leaves and twigs by six fungal isolates from nature.

    PubMed

    Djarwanto; Tachibana, S

    2010-06-15

    This research was conducted in the aim of preventing wild fire through reducing potential energy source to become in situ fertilizer. To prevent forest fires by reducing wood waste using lignocellulose-degrading fungi, six fungal isolates were tested for lignin and cellulose-degrading activity with Acacia mangium leaves and twigs over a period of 1 to 3 months. The fungi degraded 8.9-27.1% of the lignin and 14-31% of the holocellulose. The degradation rate varied depending on the fungal species. An increase in incubation time tended to decrease the amounts of holocellulose and lignin. However, the hot water soluble tended to increase following a longer incubation period. From the results obtained here, more time was needed to degrade lignin rather than other components in the sample.

  9. Looking Backward: Parting Reflections on Higher Education Reform from NAS's Founding President

    ERIC Educational Resources Information Center

    Balch, Stephen H.

    2012-01-01

    Twenty-five years at the helm of the National Association of Scholars (NAS) have left the author with vivid memories: of knocks and bruises, peaks of exhilaration and, especially, unforgettable characters. But as for lessons learned, that's a very different story. In this article, the author shares some of the successes that happened in NAS for…

  10. NAS Panel faults export controls

    NASA Astrophysics Data System (ADS)

    Katzoff, Judith A.

    A study prepared by a top-level panel says that current export controls on militarily sensitive U.S. technology may be “overcorrecting” previous weaknesses in that system, resulting in “a complex and confusing control system” that makes it more difficult for U.S. businesses to compete in international markets. Moreover, this control system has “an increasingly corrosive effect” on U.S. relations with allies. The panel recommended that the United States concentrate more effort on bringing about uniformity in the export control policies of countries belonging to the Coordinating Committee on Multilateral Export Controls (CoCom), i.e., most of the member nations in NATO (the North Atlantic Treaty Organization) and Japan.The 21-member panel was appointed by the Committee on Science, Engineering, and Public Policy (COSEPUP), a joint unit of the National Academy of Sciences (NAS), the National Academy of Engineering (NAE), and the Institute of Medicine (IOM). The panel, composed of administrators, researchers, and former government officials, was chaired by AGU member Lew Allen, Jr., director of the Jet Propulsion Laboratory (Pasadena, Calif.) and former chief of staff of the U.S. Air Force. Their report was supported by NAS funds, by a number of private organizations (including AGU), by the U.S. Departments of Commerce, Defense, Energy, and State, by the National Science Foundation, and by the National Aeronautics and Space Administration.

  11. An improved NAS-RIF algorithm for image restoration

    NASA Astrophysics Data System (ADS)

    Gao, Weizhe; Zou, Jianhua; Xu, Rong; Liu, Changhai; Li, Hengnian

    2016-10-01

    Space optical images are inevitably degraded by atmospheric turbulence, error of the optical system and motion. In order to get the true image, a novel nonnegativity and support constants recursive inverse filtering (NAS-RIF) algorithm is proposed to restore the degraded image. Firstly the image noise is weaken by Contourlet denoising algorithm. Secondly, the reliable object support region estimation is used to accelerate the algorithm convergence. We introduce the optimal threshold segmentation technology to improve the object support region. Finally, an object construction limit and the logarithm function are added to enhance algorithm stability. Experimental results demonstrate that, the proposed algorithm can increase the PSNR, and improve the quality of the restored images. The convergence speed of the proposed algorithm is faster than that of the original NAS-RIF algorithm.

  12. Upgrades to the Probabilistic NAS Platform Air Traffic Simulation Software

    NASA Technical Reports Server (NTRS)

    Hunter, George; Boisvert, Benjamin

    2013-01-01

    This document is the final report for the project entitled "Upgrades to the Probabilistic NAS Platform Air Traffic Simulation Software." This report consists of 17 sections which document the results of the several subtasks of this effort. The Probabilistic NAS Platform (PNP) is an air operations simulation platform developed and maintained by the Saab Sensis Corporation. The improvements made to the PNP simulation include the following: an airborne distributed separation assurance capability, a required time of arrival assignment and conformance capability, and a tactical and strategic weather avoidance capability.

  13. Chemical composition and anti-inflammatory activities of the essential oils from Acacia mearnsii de Wild.

    PubMed

    Avoseh, Opeyemi N; Oyedeji, Ope-oluwa O; Aremu, Kayode; Nkeh-Chungag, Benedicta N; Songca, Sandile P; Oluwafemi, Samuel O; Oyedeji, Adebola O

    2015-01-01

    The volatile oils of the leaves and the stem bark of Acacia mearnsii de Wild obtained by hydro-distillation were analysed by gas chromatography-mass spectrometry. A total of 20, 38, 29 and 38 components accounted for 93.8%, 92.1%, 78.5% and 90.9% of the total oils of the fresh, dry leaves and fresh, dry stem bark, respectively. The major components of the oil were octadecyl alcohol (25.5%) and phytol (10.5%); cis-verbenol (29.5%); phytol (10.1%) and phytol (23.4%) for the fresh leaves, dried leaves, fresh stem, dry stem bark, respectively. Oral administration of essential oils at a dose of 2% showed significant (p < 0.05) anti-inflammatory properties in the albumin-induced test model in rats. Oils from the fresh leaves and dry stems inhibited inflammation beyond 4 h post treatment. The potent anti-inflammatory activity of essential oils of A. mearnsii hereby confirmed its traditional use in treating various inflammatory diseases.

  14. Neonatal Abstinence Syndrome (NAS) in Southwestern Border States: Examining Trends, Population Correlates, and Implications for Policy.

    PubMed

    Hussaini, Khaleel S; Garcia Saavedra, Luigi F

    2018-03-23

    Introduction Neonatal abstinence syndrome (NAS) is withdrawal syndrome in newborns following birth and is primarily caused by maternal drug use during pregnancy. This study examines trends, population correlates, and policy implications of NAS in two Southwest border states. Materials and Methods A cross-sectional analysis of Hospital Inpatient Discharge Data (HIDD) was utilized to examine the incidence of NAS in the Southwest border states of Arizona (AZ) and New Mexico (NM). All inpatient hospital births in AZ and NM from January 1, 2008 through December 31, 2013 with ICD9-CM codes for NAS (779.5), cocaine (760.72), or narcotics (760.75) were extracted. Results During 2008-2013 there were 1472 NAS cases in AZ and 888 in NM. The overall NAS rate during this period was 2.83 per 1000 births (95% CI 2.68-2.97) in AZ and 5.31 (95% CI 4.96-5.66) in NM. NAS rates increased 157% in AZ and 174% in NM. NAS newborns were more likely to have low birth weight, have respiratory distress, more likely to have feeding difficulties, and more likely to be on state Medicaid insurance. AZ border region (border with Mexico) had NAS rates significantly higher than the state rate (4.06 per 1000 births [95% CI 3.68-4.44] vs. 2.83 [95% CI 2.68-2.97], respectively). In NM, the border region rate (2.09 per 1000 births [95% CI 1.48-2.69]) was significantly lower than the state rate (5.31 [95% CI 4.96-5.66]). Conclusions Despite a dramatic increase in the incidence of NAS in the U.S. and, in particular, the Southwest border states of AZ and NM, there is still scant research on the overall incidence of NAS, its assessment in the southwest border, and associated long-term outcomes. The Healthy Border (HB) 2020 binational initiative of the U.S.-Mexico Border Health Commission is an initiative that addresses several public health priorities that not only include chronic and degenerative diseases, infectious diseases, injury prevention, maternal and child health but also mental health and

  15. NAS Parallel Benchmarks. 2.4

    NASA Technical Reports Server (NTRS)

    VanderWijngaart, Rob; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    We describe a new problem size, called Class D, for the NAS Parallel Benchmarks (NPB), whose MPI source code implementation is being released as NPB 2.4. A brief rationale is given for how the new class is derived. We also describe the modifications made to the MPI (Message Passing Interface) implementation to allow the new class to be run on systems with 32-bit integers, and with moderate amounts of memory. Finally, we give the verification values for the new problem size.

  16. Effects of Gelam and Acacia honey acute administration on some biochemical parameters of Sprague Dawley rats

    PubMed Central

    2014-01-01

    Background Since ancient times, honey has been used for medicinal purposes in many cultures; it is one of the oldest and most enduring substances used in wound management. Scientific evidence for its efficacy is widely studied, but systemic safety studies are still lacking. It is essential to study the impact of consumption of honey on the health and proper development of the consumer. Therefore, the present study was designed to observe the effects of acute administration (14 days) of Gelam honey (GH), a wild harvesting honey and Acacia honey (AH), a beekeeping honey, on male and female Sprague Dawley (SD) rats. Methods An acute oral study was performed following OECD test guideline 423, with minor modifications. In the study, GH, AH and sucrose (S) were administered at 2000 mg/kg body weight. Animals were observed for the next 14 days. Gross pathology was performed at the end of the study. Animals were observed for mortality, morbidity, body weight changes, feed and water intake. Clinical biochemistry, gross pathology, relative organ weight and histopathological examination were performed. Results Rats fed with honey did not exhibit any abnormal signs or deaths. Results showed a decrease in weight gain and energy efficiency, but significantly increased in total food intake and total calories in female rats fed with GH, compared to control (p < 0.05). Nevertheless, a significant increase in body weight was observed in male rats in all honey-treated groups. Male rats fed with AH significantly decreased in total food intake, total calories and energy efficiency. Both male and female rats fed with GH displayed a significant decrease in triglycerides compared to control group. Hepatic and renal function levels were within acceptable range. The gross necropsy analysis did not reveal changes in any of the organs examined. Conclusions Our results suggest that acute consumption of GH and AH at 2000 mg/kg body weight of male and female SD rats has some discrepancy

  17. Effects of Gelam and Acacia honey acute administration on some biochemical parameters of Sprague Dawley rats.

    PubMed

    Samat, Suhana; Nor, Nor Azmi Md; Nor Hussein, Fuzina; Ismail, Wan Iryani Wan

    2014-05-04

    Since ancient times, honey has been used for medicinal purposes in many cultures; it is one of the oldest and most enduring substances used in wound management. Scientific evidence for its efficacy is widely studied, but systemic safety studies are still lacking. It is essential to study the impact of consumption of honey on the health and proper development of the consumer. Therefore, the present study was designed to observe the effects of acute administration (14 days) of Gelam honey (GH), a wild harvesting honey and Acacia honey (AH), a beekeeping honey, on male and female Sprague Dawley (SD) rats. An acute oral study was performed following OECD test guideline 423, with minor modifications. In the study, GH, AH and sucrose (S) were administered at 2000 mg/kg body weight. Animals were observed for the next 14 days. Gross pathology was performed at the end of the study. Animals were observed for mortality, morbidity, body weight changes, feed and water intake. Clinical biochemistry, gross pathology, relative organ weight and histopathological examination were performed. Rats fed with honey did not exhibit any abnormal signs or deaths. Results showed a decrease in weight gain and energy efficiency, but significantly increased in total food intake and total calories in female rats fed with GH, compared to control (p<0.05). Nevertheless, a significant increase in body weight was observed in male rats in all honey-treated groups. Male rats fed with AH significantly decreased in total food intake, total calories and energy efficiency. Both male and female rats fed with GH displayed a significant decrease in triglycerides compared to control group. Hepatic and renal function levels were within acceptable range. The gross necropsy analysis did not reveal changes in any of the organs examined. Our results suggest that acute consumption of GH and AH at 2000 mg/kg body weight of male and female SD rats has some discrepancy effects on biochemical parameters but in line

  18. Operational implications and proposed infrastructure changes for NAS integration of remotely piloted aircraft (RPA)

    DOT National Transportation Integrated Search

    2014-12-01

    The intent of this report is to provide (1) an initial assessment of National Airspace System (NAS) infrastructure affected by continuing development and deployment of unmanned aircraft systems into the NAS, and (2) a description of process challenge...

  19. UAS in the NAS: Survey Responses by ATC, Manned Aircraft Pilots, and UAS Pilots

    NASA Technical Reports Server (NTRS)

    Comstock, James R., Jr.; McAdaragh, Raymon; Ghatas, Rania W.; Burdette, Daniel W.; Trujillo, Anna C.

    2014-01-01

    NASA currently is working with industry and the Federal Aviation Administration (FAA) to establish future requirements for Unmanned Aircraft Systems (UAS) flying in the National Airspace System (NAS). To work these issues NASA has established a multi-center "UAS Integration in the NAS" project. In order to establish Ground Control Station requirements for UAS, the perspective of each of the major players in NAS operations was desired. Three on-line surveys were administered that focused on Air Traffic Controllers (ATC), pilots of manned aircraft, and pilots of UAS. Follow-up telephone interviews were conducted with some survey respondents. The survey questions addressed UAS control, navigation, and communications from the perspective of small and large unmanned aircraft. Questions also addressed issues of UAS equipage, especially with regard to sense and avoid capabilities. From the civilian ATC and military ATC perspectives, of particular interest are how mixed operations (manned / UAS) have worked in the past and the role of aircraft equipage. Knowledge gained from this information is expected to assist the NASA UAS Integration in the NAS project in directing research foci thus assisting the FAA in the development of rules, regulations, and policies related to UAS in the NAS.

  20. UAS in the NAS: Survey Responses by ATC, Manned Aircraft Pilots, and UAS Pilots

    NASA Technical Reports Server (NTRS)

    Comstock, James R., Jr.; McAdaragh, Raymon; Ghatas, Rania W.; Burdette, Daniel W.; Trujillo, Anna C.

    2013-01-01

    NASA currently is working with industry and the Federal Aviation Administration (FAA) to establish future requirements for Unmanned Aircraft Systems (UAS) flying in the National Airspace System (NAS). To work these issues NASA has established a multi-center UAS Integration in the NAS project. In order to establish Ground Control Station requirements for UAS, the perspective of each of the major players in NAS operations was desired. Three on-line surveys were administered that focused on Air Traffic Controllers (ATC), pilots of manned aircraft, and pilots of UAS. Follow-up telephone interviews were conducted with some survey respondents. The survey questions addressed UAS control, navigation, and communications from the perspective of small and large unmanned aircraft. Questions also addressed issues of UAS equipage, especially with regard to sense and avoid capabilities. From the ATC and military ATC perspective, of particular interest is how mixed-operations (manned/UAS) have worked in the past and the role of aircraft equipage. Knowledge gained from this information is expected to assist the NASA UAS in the NAS project in directing research foci thus assisting the FAA in the development of rules, regulations, and policies related to UAS in the NAS.

  1. Comparison of Origin 2000 and Origin 3000 Using NAS Parallel Benchmarks

    NASA Technical Reports Server (NTRS)

    Turney, Raymond D.

    2001-01-01

    This report describes results of benchmark tests on the Origin 3000 system currently being installed at the NASA Ames National Advanced Supercomputing facility. This machine will ultimately contain 1024 R14K processors. The first part of the system, installed in November, 2000 and named mendel, is an Origin 3000 with 128 R12K processors. For comparison purposes, the tests were also run on lomax, an Origin 2000 with R12K processors. The BT, LU, and SP application benchmarks in the NAS Parallel Benchmark Suite and the kernel benchmark FT were chosen to determine system performance and measure the impact of changes on the machine as it evolves. Having been written to measure performance on Computational Fluid Dynamics applications, these benchmarks are assumed appropriate to represent the NAS workload. Since the NAS runs both message passing (MPI) and shared-memory, compiler directive type codes, both MPI and OpenMP versions of the benchmarks were used. The MPI versions used were the latest official release of the NAS Parallel Benchmarks, version 2.3. The OpenMP versiqns used were PBN3b2, a beta version that is in the process of being released. NPB 2.3 and PBN 3b2 are technically different benchmarks, and NPB results are not directly comparable to PBN results.

  2. Effect of antimony on the deep-level traps in GaInNAsSb thin films

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

    Islam, Muhammad Monirul, E-mail: islam.monir.ke@u.tsukuba.ac.jp; Miyashita, Naoya; Ahsan, Nazmul

    2014-09-15

    Admittance spectroscopy has been performed to investigate the effect of antimony (Sb) on GaInNAs material in relation to the deep-level defects in this material. Two electron traps, E1 and E2 at an energy level 0.12 and 0.41 eV below the conduction band (E{sub C}), respectively, were found in undoped GaInNAs. Bias-voltage dependent admittance confirmed that E1 is an interface-type defect being spatially localized at the GaInNAs/GaAs interface, while E2 is a bulk-type defect located around mid-gap of GaInNAs layer. Introduction of Sb improved the material quality which was evident from the reduction of both the interface and bulk-type defects.

  3. Acacia nilotica (Babool) leaf extract mediated size-controlled rapid synthesis of gold nanoparticles and study of its catalytic activity

    NASA Astrophysics Data System (ADS)

    Majumdar, Rakhi; Bag, Braja Gopal; Maity, Nabasmita

    2013-09-01

    The leaf extract of Acacia nilotica (Babool) is rich in different types of plant secondary metabolites such as flavanoids, tannins, triterpenoids, saponines, etc. We have demonstrated the use of the leaf extract for the synthesis of gold nanoparticles in water at room temperature under very mild conditions. The synthesis of the gold nanoparticles was complete in several minutes, and no extra stabilizing or capping agents were necessary. The size of the nanoparticles could be controlled by varying the concentration of the leaf extract. The gold nanoparticles were characterized by HRTEM, surface plasmon resonance spectroscopy, and X-ray diffraction studies. The synthesized gold nanoparticles have been used as an efficient catalyst for the reduction of 4-nitrophenol to 4-aminophenol in water at room temperature.

  4. NAS Grid Benchmarks: A Tool for Grid Space Exploration

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael; VanderWijngaart, Rob F.; Biegel, Bryan (Technical Monitor)

    2001-01-01

    We present an approach for benchmarking services provided by computational Grids. It is based on the NAS Parallel Benchmarks (NPB) and is called NAS Grid Benchmark (NGB) in this paper. We present NGB as a data flow graph encapsulating an instance of an NPB code in each graph node, which communicates with other nodes by sending/receiving initialization data. These nodes may be mapped to the same or different Grid machines. Like NPB, NGB will specify several different classes (problem sizes). NGB also specifies the generic Grid services sufficient for running the bench-mark. The implementor has the freedom to choose any specific Grid environment. However, we describe a reference implementation in Java, and present some scenarios for using NGB.

  5. Examination of Frameworks for Safe Integration of Intelligent Small UAS into the NAS

    NASA Technical Reports Server (NTRS)

    Logan, Michael J.

    2012-01-01

    This paper discusses a proposed framework for the safe integration of small unmanned aerial systems (sUAS) into the National Airspace System (NAS). The paper briefly examines the potential uses of sUAS to build an understanding of the location and frequency of potential future flight operations based on the future applications of the sUAS systems. The paper then examines the types of systems that would be required to meet the application-level demand to determine "classes" of platforms and operations. A framework for categorization of the "intelligence" level of the UAS is postulated for purposes of NAS integration. Finally, constraints on the intelligent systems are postulated to ensure their ease of integration into the NAS.

  6. First-principles study on structure stabilities of α-S and Na-S battery systems

    NASA Astrophysics Data System (ADS)

    Momida, Hiroyoshi; Oguchi, Tamio

    2014-03-01

    To understand microscopic mechanisms of charge and discharge reactions in Na-S batteries, there has been increasing needs to study fundamental atomic and electronic structures of elemental S as well as that of Na-S phases. The most stable form of S is known to be an orthorhombic α-S crystal at ambient temperature and pressure, and α-S consists of puckered S8 rings which crystallize in space group Fddd . In this study, the crystal structure of α-S is examined by using first-principles calculations with and without the van der Waals interaction corrections of Grimme's method, and results clearly show that the van der Waals interactions between the S8 rings have crucial roles on cohesion of α-S. We also study structure stabilities of Na2S, NaS, NaS2, and Na2S5 phases with reported crystal structures. Using calculated total energies of the crystal structure models, we estimate discharge voltages assuming discharge reactions from 2Na+ xS -->Na2Sx, and discharge reactions in Na/S battery systems are discussed by comparing with experimental results. This work was partially supported by Elements Strategy Initiative for Catalysts and Batteries (ESICB) of Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan.

  7. Triterpenoids from Acacia ataxacantha DC: antimicrobial and antioxidant activities.

    PubMed

    Amoussa, Abdou Madjid O; Lagnika, Latifou; Bourjot, Mélanie; Vonthron-Senecheau, Cathérine; Sanni, Ambaliou

    2016-08-12

    Acacia ataxacantha is a medicinal specie used extensively in traditional medicine of Benin republic to treat infectious diseases. Our previous study showed interesting antibacterial and antifungal activities against six strains of bacteria and six strains of fungi. The aim of this study was to investigate the antimicrobial and antioxidant activities of compounds isolated from A. ataxacantha. Chromatographic and spectroscopic methods were used to isolate and identify three compounds (1-3) from the bark of A. ataxacantha. Phytochemical investigation of A. ataxacantha (Fabaceae) led to the isolation of three triterpenoids (1-3). The structure of isolated compounds was established by differents spectroscopic methods such as UV, (1)H NMR, (13)C NMR, 2D NMR and Mass. All isolated compounds were tested for antimicrobial activity using agar disc-diffusion and microdilution methods. The radical scavenging activity of isolated compounds was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Phytochemical investigation led to the isolation and identification of lupeol (1), betulinic acid (2) and betulinic acid-3-trans-caffeate (3). Moderate antimicrobial activity was obtained with compound 3 against methicillin-resitant Staphylococcus aureus, Enterococcus feacalis and Pseudomonas aeruginosa with MIC value of 25 μg/ml and Staphylococcus aureus (MIC of 50 μg/ml). Compounds 3 was more active against Staphylococcus epidermidis and Candida albicans with a MIC value of 12.5 μg/ml in boths cases. Compounds 3 had also interesting antioxidant activity with an IC50 of 3.57 μg/ml compared to quercetin (1.04 μg/ml). The overall results of this study provide evidence that the compound 3, isolated from A. ataxacantha, exhibit antimicrobial activity against Gram-positive and Gram-negative bacteria and yeast, especially against C. albicans.

  8. Data communication requirements for the advanced NAS network

    NASA Technical Reports Server (NTRS)

    Levin, Eugene; Eaton, C. K.; Young, Bruce

    1986-01-01

    The goal of the Numerical Aerodynamic Simulation (NAS) Program is to provide a powerful computational environment for advanced research and development in aeronautics and related disciplines. The present NAS system consists of a Cray 2 supercomputer connected by a data network to a large mass storage system, to sophisticated local graphics workstations, and by remote communications to researchers throughout the United States. The program plan is to continue acquiring the most powerful supercomputers as they become available. In the 1987/1988 time period it is anticipated that a computer with 4 times the processing speed of a Cray 2 will be obtained and by 1990 an additional supercomputer with 16 times the speed of the Cray 2. The implications of this 20-fold increase in processing power on the data communications requirements are described. The analysis was based on models of the projected workload and system architecture. The results are presented together with the estimates of their sensitivity to assumptions inherent in the models.

  9. Hypoglycemic effects of Acacia nilotica in type II diabetes: a research proposal.

    PubMed

    Roozbeh, Nasibeh; Darvish, Leili; Abdi, Fatemeh

    2017-07-26

    Diabetes mellitus is a common metabolic disorder throughout the world which can negatively affect the function of various body organs. Due to their availability and few side effects, herbal medicines have been proposed as suitable alternatives in the management of diabetes. Previous studies have confirmed the anti diabetic properties of Acacia nilotica. The hypoglycemic effects of this plant have been attributed to its role in stimulating the islets of Langerhans to produce more insulin. The present paper describes a systematic review protocol for the assessment of the hypoglycemic effects of A. nilotica. Randomized and non-randomized placebo-controlled clinical trials, performed during 1999-2016 will be included. The outcomes will be measured through FBS, GCT, GTT, and OGTT in all of studies and in addition to these tests, will be measured 2HPP and HbA1c level in human study. Well-known databases will be searched for selected key terms A. nilotica, type II diabetes and hypoglycemia. The quality assessment of the selected papers will be evaluated based on SYRCLE and Cochrane Risk of Bias Tool. We believe that our findings will provide details about difficulties researchers face during the design of protocols or implementation of scientific studies. Ultimately, the publication of our findings will facilitate the development of effective treatment strategies to promote the health of people with type II DM. PROSPERO registration CRD42016053141.

  10. Nitrogen metabolism of sheep and goats consuming Acacia brevispica and Sesbania sesban

    USGS Publications Warehouse

    Woodward, A.; Reed, J.D.

    1997-01-01

    We described the effects of two East African browses, Acacia brevispica and Sesbania sesban, on nitrogen metabolism of sheep and goats. The A. brevispica had a substantial amount of proanthocyanidins (condensed tannins); S. sesban did not. The browses were fed at three levels in combination with vetch (Vicia dasycarpa) and teff straw (Eragrostis abyssinica). Fecal N, N balance, and plasma urea N (PUN) were estimated with intact animals. Ruminal ammonia (RuA) and VFA concentrations were estimated with ruminally fistulated animals. Urinary N loss, PUN, RuA, and VFA concentrations were higher for S. sesban diets than for A. brevispica diets. Fecal N was highest with diets including A. brevispica due to high levels of fecal neutral-detergent insoluble N. Nitrogen retention was highest for diets including S. sesban. Nitrogen retention was adequate for A. brevispica diets because low urinary N compensated for high fecal N. Four hypotheses describe possible effects of tannins on N metabolism: 1) escape of protein from the rumen to the lower tract; 2) increased microbial yield; 3) increase in N-containing endogenous products; and 4) protein made indigestible in tannin-protein complexes. The effect of tannins in A. brevispica on N metabolism can best be described by the formation of indigestible tannin-protein complexes, although increased production of endogenous products is also possible.

  11. Monosaccharide composition of acidic gum exudates from Indian Acacia tortilis ssp. raddiana (Savi) Brenan.

    PubMed

    Lakhera, Ajeet Kumar; Kumar, Vineet

    2017-01-01

    Acacia tortilis ssp. raddiana (Savi) Brenan commonly known as Israeli Babool has contributed immensely for sand dunes management in Indian desert leading to wind erosion control and increased biological productivity. The species is extensively used in traditional medicine system for a number of therapeutic applications and as nutraceutical. The polysaccharide was isolated in 43.6% yield from gum exudates. The monosaccharides, L-arabinose, D-galactose D-glucose, L-rhamnose and D-mannose were determined in molar ratio of 78.1%, 18.64%, 0.60%, 1.71% and 0.74% respectively. The molar ratio of uronic acids was studied using diverse spectrophotometric methods and compared with GLC. The content of D-galacturonic acid and D-glucuronic was determined as 3.88% and 4.35% respectively by GLC. The results were compared with the spectrophotometric methods. The results using DMP as chromogenic reagent are closer to that obtained by GLC. Structural analysis of the polysaccharide may provide scientific basis for nutraceutical, pharmaceutical and biological applications of gum exudates from A. tortilis, which is extensively planted in India. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Acacia gum as modifier of thermal stability, solubility and emulsifying properties of α-lactalbumin.

    PubMed

    de Oliveira, Fabíola Cristina; Dos Reis Coimbra, Jane Sélia; de Oliveira, Eduardo Basílio; Rodrigues, Marina Quadrio Raposo Branco; Sabioni, Rachel Campos; de Souza, Bartolomeu Warlene Silva; Santos, Igor José Boggione

    2015-03-30

    Protein-polysaccharide conjugates often display improved techno-functional properties when compared to their individual involved biomolecules. α-Lactalbumin:acacia gum (α-la:AG) conjugates were prepared via Maillard reaction by the dry-heating method. Conjugate formation was confirmed using results of absorbance, o-phthalaldehyde test, sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE) and size exclusion chromatography. Techno-functional properties (emulsifying characteristics, solubility, and thermal stability) were evaluated for α-la, α-la/AG mixtures and α-la:AG conjugates. Conjugate thermal stability was improved compared to pure α-la treated at the same conditions of conjugate formation. Response surface methodology was used to establish models to predict solubility and emulsifying activity as functions of the salt concentration, pH and reaction time. α-la:AG conjugate solubility is affected in a complex manner by the three factors analyzed. Emulsifying activity index (EAI) of α-la is significantly affected by pH, while the α-la:AG EAI is affected by the three analyzed factors. Both solubility and EAI are maximized with pH 8.0, NaCl concentration of 0.3 mol L(-1) and two days of Maillard reaction. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Acacia catechu ethanolic bark extract induces apoptosis in human oral squamous carcinoma cells.

    PubMed

    Lakshmi, Thangavelu; Ezhilarasan, Devaraj; Vijayaragavan, Rajagopal; Bhullar, Sukhwinder Kaur; Rajendran, Ramasamy

    2017-01-01

    Oral cancer is in approximately 30% of all cancers in India. This study was conducted to evaluate the cytotoxic activity of ethanolic extract of Acacia catechu bark (ACB) against human squamous cell carcinoma cell line-25 (SCC-25). Cytotoxic effect of ACB extract was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide assay. A. catechu extract was treated SCC-25 cells with 25 and 50 μg/mL for 24 h. Apoptosis markers such as caspases-8 and 9, bcl-2, bax, and cytochrome c (Cyt-c) were done by RT-PCR. Morphological changes of ACB treated cells were evaluated using acridine orange/ethidium bromide (AO/EB) dual staining. Nuclear morphology and DNA fragmentation were evaluated using propidium iodide (PI) staining. Further, cell cycle analysis was performed using flow cytometry. A. catechu treatment caused cytotoxicity in SCC-25 cells with an IC 50 of 52.09 μg/mL. Apoptotic marker gene expressions were significantly increased on ACB treatment. Staining with AO/EB and PI shows membrane blebbing and nuclear membrane distortion, respectively, and it confirms the apoptosis induction in SCC-25 cells. These results suggest that ACB extract can be used as a modulating agent in oral squamous cell carcinoma.

  14. Ubiquity and Diversity of Heterotrophic Bacterial nasA Genes in Diverse Marine Environments

    PubMed Central

    Jiang, Xuexia; Dang, Hongyue; Jiao, Nianzhi

    2015-01-01

    Nitrate uptake by heterotrophic bacteria plays an important role in marine N cycling. However, few studies have investigated the diversity of environmental nitrate assimilating bacteria (NAB). In this study, the diversity and biogeographical distribution of NAB in several global oceans and particularly in the western Pacific marginal seas were investigated using both cultivation and culture-independent molecular approaches. Phylogenetic analyses based on 16S rRNA and nasA (encoding the large subunit of the assimilatory nitrate reductase) gene sequences indicated that the cultivable NAB in South China Sea belonged to the α-Proteobacteria, γ-Proteobacteria and CFB (Cytophaga-Flavobacteria-Bacteroides) bacterial groups. In all the environmental samples of the present study, α-Proteobacteria, γ-Proteobacteria and Bacteroidetes were found to be the dominant nasA-harboring bacteria. Almost all of the α-Proteobacteria OTUs were classified into three Roseobacter-like groups (I to III). Clone library analysis revealed previously underestimated nasA diversity; e.g. the nasA gene sequences affiliated with β-Proteobacteria, ε-Proteobacteria and Lentisphaerae were observed in the field investigation for the first time, to the best of our knowledge. The geographical and vertical distributions of seawater nasA-harboring bacteria indicated that NAB were highly diverse and ubiquitously distributed in the studied marginal seas and world oceans. Niche adaptation and separation and/or limited dispersal might mediate the NAB composition and community structure in different water bodies. In the shallow-water Kueishantao hydrothermal vent environment, chemolithoautotrophic sulfur-oxidizing bacteria were the primary NAB, indicating a unique nitrate-assimilating community in this extreme environment. In the coastal water of the East China Sea, the relative abundance of Alteromonas and Roseobacter-like nasA gene sequences responded closely to algal blooms, indicating that NAB may be

  15. Synthesis and characterization of Acacia gum-Fe0Np-silica nanocomposite: an efficient Fenton-like catalyst for the degradation of Remazol Brilliant Violet dye

    NASA Astrophysics Data System (ADS)

    Singh, Vandana; Singh, Jadveer; Srivastava, Preeti

    2018-04-01

    Acacia gum-Fe0Np-silica nanocomposite (GFS1) has been crafted through sol-gel technique using a two-step process that involved the reduction of iron salt to zerovalent iron nanoparticles (Fe0Nps) followed by their impregnation within Acacia gum-silica matrix. GFS1 was characterized using Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray analysis (EDX), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometry (VSM), and X-ray photoelectron spectroscopy (XPS) techniques. GFS1 is decorated with Fe0Nps of 5 nm average size. The VSM study revealed that GFS1 has ferromagnetic nature. GFS1 was used as a heterogeneous Fenton-like catalyst for the degradation of azo dyes using Remazol Brilliant Violet (RBV) dye as a model dye. In first 5 min of operation, > 86% dye degradation was achieved and 94% dye (from 100 mg L-1 dye solution) was successfully degraded in 50 min. The dye degradation followed pseudo-first-order kinetics. The GFS1 performed efficiently well over the wide range of dye concentrations (25-200 mg L-1). The catalyst was reused for eight repeated cycles where 12.5% dye degradation was possible even in the eighth cycle. The catalyst behaved fairly well for the degradation of Metanil Yellow (MY) and Orange G (OG) dyes also. Under the optimum conditions of RBV dye degradation, Metanil Yellow (MY) and Orange G (OG) dyes were degraded to the extent of 97 and 26.3%, respectively.

  16. Autotasked Performance in the NAS Workload: A Statistical Analysis

    NASA Technical Reports Server (NTRS)

    Carter, R. L.; Stockdale, I. E.; Kutler, Paul (Technical Monitor)

    1998-01-01

    A statistical analysis of the workload performance of a production quality FORTRAN code for five different Cray Y-MP hardware and system software configurations is performed. The analysis was based on an experimental procedure that was designed to minimize correlations between the number of requested CPUs and the time of day the runs were initiated. Observed autotasking over heads were significantly larger for the set of jobs that requested the maximum number of CPUs. Speedups for UNICOS 6 releases show consistent wall clock speedups in the workload of around 2. which is quite good. The observed speed ups were very similar for the set of jobs that requested 8 CPUs and the set that requested 4 CPUs. The original NAS algorithm for determining charges to the user discourages autotasking in the workload. A new charging algorithm to be applied to jobs run in the NQS multitasking queues also discourages NAS users from using auto tasking. The new algorithm favors jobs requesting 8 CPUs over those that request less, although the jobs requesting 8 CPUs experienced significantly higher over head and presumably degraded system throughput. A charging algorithm is presented that has the following desirable characteristics when applied to the data: higher overhead jobs requesting 8 CPUs are penalized when compared to moderate overhead jobs requesting 4 CPUs, thereby providing a charging incentive to NAS users to use autotasking in a manner that provides them with significantly improved turnaround while also maintaining system throughput.

  17. UAS Integration in the NAS FY15 Annual Review

    NASA Technical Reports Server (NTRS)

    Grindle, Laurie; Randall, Debra; Hackenburg, Davis

    2015-01-01

    This presentation gives insight into the research activities and efforts being executed in order to integrate unmanned aircraft systems into the national airspace system. This briefing is to inform others of the UAS-NAS progress and future directions.

  18. Nas transgenic mouse line allows visualization of Notch pathway activity in vivo

    PubMed Central

    Souilhol, Céline; Cormier, Sarah; Monet, Marie; Vandormael-Pournin, Sandrine; Joutel, Anne; Babinet, Charles; Cohen-Tannoudji, Michel

    2006-01-01

    The Notch signalling pathway plays multiple and important roles in mammals. However, several aspects of its action, in particular the precise mapping of its sites of activity, remain unclear. To address this issue, we have generated a transgenic line carrying a construct consisting of a nls-lacZ reporter gene under the control of a minimal promoter and multiple RBP-Jκ binding sites. Here we show that this transgenic line, we named NAS for Notch Activity Sensor, displays an expression profile that is consistent with current knowledge on Notch activity sites in mice, even though it may not report on all these sites. Moreover, we observe that NAS transgene expression is abolished in a RBP-Jκ deficient background indicating that it indeed requires Notch/RBP-Jκ signalling pathway activity. Thus, the NAS transgenic line constitutes a valuable and versatile tool to gain further insights into the complex and various functions of the Notch signalling pathway. PMID:16708386

  19. Investigations of the Optical Properties of GaNAs Alloys by First-Principle.

    PubMed

    Borovac, Damir; Tan, Chee-Keong; Tansu, Nelson

    2017-12-11

    We present a Density Functional Theory (DFT) analysis of the optical properties of dilute-As GaN 1-x As x alloys with arsenic (As) content ranging from 0% up to 12.5%. The real and imaginary parts of the dielectric function are investigated, and the results are compared to experimental and theoretical values for GaN. The analysis extends to present the complex refractive index and the normal-incidence reflectivity. The refractive index difference between GaN and GaNAs alloys can be engineered to be up to ~0.35 in the visible regime by inserting relatively low amounts of As-content into the GaN system. Thus, the analysis elucidates on the birefringence of the dilute-As GaNAs alloys and comparison to other experimentally characterized III-nitride systems is drawn. Our findings indicate the potential of GaNAs alloys for III-nitride based waveguide and photonic circuit design applications.

  20. Nas transgenic mouse line allows visualization of Notch pathway activity in vivo.

    PubMed

    Souilhol, Céline; Cormier, Sarah; Monet, Marie; Vandormael-Pournin, Sandrine; Joutel, Anne; Babinet, Charles; Cohen-Tannoudji, Michel

    2006-06-01

    The Notch signaling pathway plays multiple and important roles in mammals. However, several aspects of its action, in particular, the precise mapping of its sites of activity, remain unclear. To address this issue, we generated a transgenic line carrying a construct consisting of a nls-lacZ reporter gene under the control of a minimal promoter and multiple RBP-Jkappa binding sites. Here we show that this transgenic line, which we termed NAS (for Notch Activity Sensor), displays an expression profile that is consistent with current knowledge on Notch activity sites in mice, even though it may not report on all these sites. Moreover, we observe that NAS transgene expression is abolished in a RBP-Jkappa-deficient background, indicating that it indeed requires Notch/RBP-Jkappa signaling pathway activity. Thus, the NAS transgenic line constitutes a valuable and versatile tool to gain further insights into the complex and various functions of the Notch signaling pathway.

  1. Padrões de refluxo nas veias safenas em homens com insuficiência venosa crônica

    PubMed Central

    Engelhorn, Carlos Alberto; Coral, Francisco Eduardo; Soares, Isabela Chaves Monteiro; Corrêa, Gabriel Fernando de Araújo; Ogeda, Jaqueline Pozzolo; Hara, Larissa Yuri; Murasse, Luisa Saemi

    2016-01-01

    Resumo Contexto A insuficiência venosa crônica (IVCr) é frequente e predomina nas mulheres, mas ainda há poucas informações sobre o refluxo nas veias safenas na população masculina. Objetivos Identificar os diferentes padrões de refluxo nas veias safenas magnas (VSMs) e parvas (VSPs) em homens, correlacionando esses dados com a apresentação clínica conforme a classificação Clínica, Etiológica, Anatômica e Fisiopatológica (CEAP). Métodos Foram avaliados 369 membros inferiores de 207 homens pela ultrassonografia vascular (UV) com diagnóstico clínico de IVCr primária. As variáveis analisadas foram a classificação CEAP, o padrão de refluxo nas VSMs e VSPs e a correlação entre os dois. Resultados Nos 369 membros avaliados, 72,9% das VSMs apresentaram refluxo com predominância do padrão segmentar (33,8%). Nas VSPs, 16% dos membros inferiores analisados apresentaram refluxo, sendo o mais frequente o padrão distal (33,9%). Dos membros classificados como C4, C5 e C6, 100% apresentaram refluxo na VSM com predominância do refluxo proximal (25,64%), e 38,46% apresentaram refluxo na VSP com equivalência entre os padrões distal e proximal (33,3%). Refluxo na junção safeno-femoral (JSF) foi detectado em 7,1% dos membros nas classes C0 e C1, 35,6% nas classes C2 e C3, e 64,1% nas classes C4 a C6. Conclusões O padrão de refluxo segmentar é predominante na VSM, e o padrão de refluxo distal é predominante na VSP. A ocorrência de refluxo na JSF é maior em pacientes com IVCr mais avançada. PMID:29930603

  2. Removal of 4-nitrophenol from aqueous solution by adsorption onto activated carbon prepared from Acacia glauca sawdust.

    PubMed

    Dhorabe, Prashant T; Lataye, Dilip H; Ingole, Ramakant S

    2016-01-01

    The present paper deals with a complete batch adsorption study of 4-nitrophenol (4NP) from aqueous solution onto activated carbon prepared from Acacia glauca sawdust (AGAC). The surface area of the adsorbent determined by methylene blue method is found to be 311.20 m(2)/g. The optimum dose of adsorbent was found to be 2 g/l with 4NP uptake of 25.93 mg/g. The equilibrium time was found to be 30 minutes with the percentage removal of 96.40 at the initial concentration of 50 ppm. The maximum removal of 98.94% was found to be at pH of 6. The equilibrium and kinetic study revealed that the Radke-Prausnitz isotherm and pseudo second order kinetics model fitted the respective data well. In the thermodynamic study, the negative value of Gibbs free energy change (-26.38 kJ/mol at 30°C) and enthalpy change (-6.12 kJ/mol) showed the spontaneous and exothermic nature of the adsorption process.

  3. Combustion and kinetic parameters estimation of torrefied pine, acacia and Miscanthus giganteus using experimental and modelling techniques.

    PubMed

    Wilk, Małgorzata; Magdziarz, Aneta; Gajek, Marcin; Zajemska, Monika; Jayaraman, Kandasamy; Gokalp, Iskender

    2017-11-01

    A novel approach, linking both experiments and modelling, was applied to obtain a better understanding of combustion characteristics of torrefied biomass. Therefore, Pine, Acacia and Miscanthus giganteus have been investigated under 260°C, 1h residence time and argon atmosphere. A higher heating value and carbon content corresponding to a higher fixed carbon, lower volatile matter, moisture content, and ratio O/C were obtained for all torrefied biomass. TGA analysis was used in order to proceed with the kinetics study and Chemkin calculations. The kinetics analysis demonstrated that the torrefaction process led to a decrease in Ea compared to raw biomass. The average Ea of pine using the KAS method changed from 169.42 to 122.88kJ/mol. The changes in gaseous products of combustion were calculated by Chemkin, which corresponded with the TGA results. The general conclusion based on these investigations is that torrefaction improves the physical and chemical properties of biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. One-dimensional carbon-sulfur composite fibers for Na-S rechargeable batteries operating at room temperature.

    PubMed

    Hwang, Tae Hoon; Jung, Dae Soo; Kim, Joo-Seong; Kim, Byung Gon; Choi, Jang Wook

    2013-09-11

    Na-S batteries are one type of molten salt battery and have been used to support stationary energy storage systems for several decades. Despite their successful applications based on long cycle lives and low cost of raw materials, Na-S cells require high temperatures above 300 °C for their operations, limiting their propagation into a wide range of applications. Herein, we demonstrate that Na-S cells with solid state active materials can perform well even at room temperature when sulfur-containing carbon composites generated from a simple thermal reaction were used as sulfur positive electrodes. Furthermore, this structure turned out to be robust during repeated (de)sodiation for ~500 cycles and enabled extraordinarily high rate performance when one-dimensional morphology is adopted using scalable electrospinning processes. The current study suggests that solid-state Na-S cells with appropriate atomic configurations of sulfur active materials could cover diverse battery applications where cost of raw materials is critical.

  5. Object-Oriented Implementation of the NAS Parallel Benchmarks using Charm++

    NASA Technical Reports Server (NTRS)

    Krishnan, Sanjeev; Bhandarkar, Milind; Kale, Laxmikant V.

    1996-01-01

    This report describes experiences with implementing the NAS Computational Fluid Dynamics benchmarks using a parallel object-oriented language, Charm++. Our main objective in implementing the NAS CFD kernel benchmarks was to develop a code that could be used to easily experiment with different domain decomposition strategies and dynamic load balancing. We also wished to leverage the object-orientation provided by the Charm++ parallel object-oriented language, to develop reusable abstractions that would simplify the process of developing parallel applications. We first describe the Charm++ parallel programming model and the parallel object array abstraction, then go into detail about each of the Scalar Pentadiagonal (SP) and Lower/Upper Triangular (LU) benchmarks, along with performance results. Finally we conclude with an evaluation of the methodology used.

  6. 78 FR 12951 - TRICARE; Elimination of the Non-Availability Statement (NAS) Requirement for Non-Emergency...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-26

    ... There are no anticipated budgetary health care cost increases. Requiring a NAS for a relatively few non... Inpatient Mental Health Care AGENCY: Office of the Secretary, Department of Defense. ACTION: Final rule... inpatient mental health care in order for a TRICARE Standard beneficiary's claim to be paid. Currently, NAS...

  7. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project FY17 Annual Review

    NASA Technical Reports Server (NTRS)

    Sakahara, Robert; Hackenberg, Davis; Johnson, William

    2017-01-01

    This presentation was presented to the Integrated Aviation Systems Program at the FY17 Annual Review of the UAS-NAS project. The presentation captures the overview of the work completed by the UAS-NAS project and its subprojects.

  8. Parallelization of NAS Benchmarks for Shared Memory Multiprocessors

    NASA Technical Reports Server (NTRS)

    Waheed, Abdul; Yan, Jerry C.; Saini, Subhash (Technical Monitor)

    1998-01-01

    This paper presents our experiences of parallelizing the sequential implementation of NAS benchmarks using compiler directives on SGI Origin2000 distributed shared memory (DSM) system. Porting existing applications to new high performance parallel and distributed computing platforms is a challenging task. Ideally, a user develops a sequential version of the application, leaving the task of porting to new generations of high performance computing systems to parallelization tools and compilers. Due to the simplicity of programming shared-memory multiprocessors, compiler developers have provided various facilities to allow the users to exploit parallelism. Native compilers on SGI Origin2000 support multiprocessing directives to allow users to exploit loop-level parallelism in their programs. Additionally, supporting tools can accomplish this process automatically and present the results of parallelization to the users. We experimented with these compiler directives and supporting tools by parallelizing sequential implementation of NAS benchmarks. Results reported in this paper indicate that with minimal effort, the performance gain is comparable with the hand-parallelized, carefully optimized, message-passing implementations of the same benchmarks.

  9. Quantum dot-like emitters formed due to alloy fluctuations in GaNAs-based nanowires.

    NASA Astrophysics Data System (ADS)

    Buyanova, Irina; Jansson, M.; Filippov, S.; Stehr, J.; Palisaitis, J.; Persson, P.; Ishikawa, F.; Chen, Weimin

    Group III-V semiconductor nanowires with embedded quantum dots (QDs) are currently attracting increasing attention as a highly attractive platform for a variety of advanced applications ranging from third generation photovoltaics to quantum information technologies. In this work, we show that local fluctuations in N composition inside coaxial GaAs/GaNAs nanowires induces three-dimensional confining potentials equivalent to that for QDs thus forming optically active and highly localized states inside the GaNAs shell. Principal quantization axis of these states is concluded to mainly coincide with the nanowire axis, based on the strong polarization of the detected emission orthogonal to the nanowire axis revealed from polarization-resolved micro-photoluminescence studies. This is partly attributed to a predominantly uniaxial tensile strain field in the GaNAs shell caused by lattice mismatch with the GaAs core. GaNAs alloys can, therefore, be used as an active material in hybrid QD-NW structures utilized for fabrication of nanoscale polarized-light sources that are efficient within the near-infrared spectral range. Financial support by the Swedish Energy Agency (Grant # P40119-1) and the Swedish Research Council (Grant # 2015-05532) is greatly appreciated.

  10. Neem gum as a binder in a formulated paracetamol tablet with reference to Acacia gum BP.

    PubMed

    Ogunjimi, Abayomi Tolulope; Alebiowu, Gbenga

    2014-04-01

    This study determined the physical, compressional, and binding properties of neem gum (NMG) obtained from the trunk of Azadirachta indica (A Juss) in a paracetamol tablet formulation in comparison with official Acacia gum BP (ACA). The physical and flow properties were evaluated using density parameters: porosity, Carr's index, Hausner's ratio, and flow rate. Compressional properties were analyzed using Heckel and Kawakita equations. The tensile strength, brittle fracture index, and crushing strength-friability/disintegration time ratio were used to evaluate the mechanical properties of paracetamol tablets while the drug release properties of the tablets were assessed using disintegration time and dissolution times. Tablet formulations containing NMG exhibited faster onset and higher amount of plastic deformation during compression than those containing ACA. Neem gum produced paracetamol tablets with lower mechanical strength; however, the tendency of the tablets to cap or laminate was lower when compared to those containing ACA. Inclusion of NMG improved the balance between binding and disintegration properties of paracetamol tablets produced than those containing ACA. Neem gum produced paracetamol tablets with lower disintegration and dissolution times than those containing ACA.

  11. Implementation of NAS Parallel Benchmarks in Java

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael; Schultz, Matthew; Jin, Hao-Qiang; Yan, Jerry

    2000-01-01

    A number of features make Java an attractive but a debatable choice for High Performance Computing (HPC). In order to gauge the applicability of Java to the Computational Fluid Dynamics (CFD) we have implemented NAS Parallel Benchmarks in Java. The performance and scalability of the benchmarks point out the areas where improvement in Java compiler technology and in Java thread implementation would move Java closer to Fortran in the competition for CFD applications.

  12. Applications Performance Under MPL and MPI on NAS IBM SP2

    NASA Technical Reports Server (NTRS)

    Saini, Subhash; Simon, Horst D.; Lasinski, T. A. (Technical Monitor)

    1994-01-01

    On July 5, 1994, an IBM Scalable POWER parallel System (IBM SP2) with 64 nodes, was installed at the Numerical Aerodynamic Simulation (NAS) Facility Each node of NAS IBM SP2 is a "wide node" consisting of a RISC 6000/590 workstation module with a clock of 66.5 MHz which can perform four floating point operations per clock with a peak performance of 266 Mflop/s. By the end of 1994, 64 nodes of IBM SP2 will be upgraded to 160 nodes with a peak performance of 42.5 Gflop/s. An overview of the IBM SP2 hardware is presented. The basic understanding of architectural details of RS 6000/590 will help application scientists the porting, optimizing, and tuning of codes from other machines such as the CRAY C90 and the Paragon to the NAS SP2. Optimization techniques such as quad-word loading, effective utilization of two floating point units, and data cache optimization of RS 6000/590 is illustrated, with examples giving performance gains at each optimization step. The conversion of codes using Intel's message passing library NX to codes using native Message Passing Library (MPL) and the Message Passing Interface (NMI) library available on the IBM SP2 is illustrated. In particular, we will present the performance of Fast Fourier Transform (FFT) kernel from NAS Parallel Benchmarks (NPB) under MPL and MPI. We have also optimized some of Fortran BLAS 2 and BLAS 3 routines, e.g., the optimized Fortran DAXPY runs at 175 Mflop/s and optimized Fortran DGEMM runs at 230 Mflop/s per node. The performance of the NPB (Class B) on the IBM SP2 is compared with the CRAY C90, Intel Paragon, TMC CM-5E, and the CRAY T3D.

  13. Conflict resolution in an ant-plant interaction: Acacia constricta traits reduce ant costs to reproduction.

    PubMed

    Nicklen, E Fleur; Wagner, Diane

    2006-05-01

    Many plant species attract ants onto their foliage with food rewards or nesting space. However, ants can interfere with plant reproduction when they visit flowers. This study tests whether Acacia constricta separates visiting ant species temporally or spatially from newly opened inflorescences and pollinators. The diurnal activity patterns of ants and A. constricta pollinators peaked at different times of day, and the activity of pollinators followed the daily dehiscence of A. constricta inflorescences. In addition to being largely temporally separated, ants rarely visited open inflorescences. A floral ant repellent contributes to the spatial separation of ants and inflorescences. In a field experiment, ants of four species were given equal access to inflorescences in different developmental stages. On average, the frequency with which ants made initial, antennal contact with the floral stages did not differ, but ants significantly avoided secondary contact with newly opened inflorescences relative to buds and old inflorescences, and old inflorescences relative to buds. Ants also avoided contact with pollen alone, indicating that pollen is at least one source of the repellent. The results suggest A. constricta has effectively resolved the potential conflict between visiting ants and plant reproduction.

  14. [Litter decomposition and nutrient release in Acacia mangium plantations established on degraded soils of Colombia].

    PubMed

    Castellanos-Barliza, Jeiner; León Peláez, Juan Diego

    2011-03-01

    Several factors control the decomposition in terrestrial ecosystems such as humidity, temperature, quality of litter and microbial activity. We investigated the effects of rainfall and soil plowing prior to the establishment of Acacia mangium plantations, using the litterbag technique, during a six month period, in forests plantations in Bajo Cauca region, Colombia. The annual decomposition constants (k) of simple exponential model, oscillated between 1.24 and 1.80, meanwhile k1 y k2 decomposition constants of double exponential model were 0.88-1.81 and 0.58-7.01. At the end of the study, the mean residual dry matter (RDM) was 47% of the initial value for the three sites. We found a slow N, Ca and Mg release pattern from the A. mangium leaf litter, meanwhile, phosphorus (P) showed a dominant immobilization phase, suggesting its low availability in soils. Chemical leaf litter quality parameters (e.g. N and P concentrations, C/N, N/P ratios and phenols content) showed an important influence on decomposition rates. The results of this study indicated that rainfall plays an important role on the decomposition process, but not soil plowing.

  15. An Integrated Gate Turnaround Management Concept Leveraging Big Data Analytics for NAS Performance Improvements

    NASA Technical Reports Server (NTRS)

    Chung, William W.; Ingram, Carla D.; Ahlquist, Douglas Kurt; Chachad, Girish H.

    2016-01-01

    "Gate Turnaround" plays a key role in the National Air Space (NAS) gate-to-gate performance by receiving aircraft when they reach their destination airport, and delivering aircraft into the NAS upon departing from the gate and subsequent takeoff. The time spent at the gate in meeting the planned departure time is influenced by many factors and often with considerable uncertainties. Uncertainties such as weather, early or late arrivals, disembarking and boarding passengers, unloading/reloading cargo, aircraft logistics/maintenance services and ground handling, traffic in ramp and movement areas for taxi-in and taxi-out, and departure queue management for takeoff are likely encountered on the daily basis. The Integrated Gate Turnaround Management (IGTM) concept is leveraging relevant historical data to support optimization of the gate operations, which include arrival, at the gate, departure based on constraints (e.g., available gates at the arrival, ground crew and equipment for the gate turnaround, and over capacity demand upon departure), and collaborative decision-making. The IGTM concept provides effective information services and decision tools to the stakeholders, such as airline dispatchers, gate agents, airport operators, ramp controllers, and air traffic control (ATC) traffic managers and ground controllers to mitigate uncertainties arising from both nominal and off-nominal airport gate operations. IGTM will provide NAS stakeholders customized decision making tools through a User Interface (UI) by leveraging historical data (Big Data), net-enabled Air Traffic Management (ATM) live data, and analytics according to dependencies among NAS parameters for the stakeholders to manage and optimize the NAS performance in the gate turnaround domain. The application will give stakeholders predictable results based on the past and current NAS performance according to selected decision trees through the UI. The predictable results are generated based on analysis of the

  16. Statistical Analysis of NAS Parallel Benchmarks and LINPACK Results

    NASA Technical Reports Server (NTRS)

    Meuer, Hans-Werner; Simon, Horst D.; Strohmeier, Erich; Lasinski, T. A. (Technical Monitor)

    1994-01-01

    In the last three years extensive performance data have been reported for parallel machines both based on the NAS Parallel Benchmarks, and on LINPACK. In this study we have used the reported benchmark results and performed a number of statistical experiments using factor, cluster, and regression analyses. In addition to the performance results of LINPACK and the eight NAS parallel benchmarks, we have also included peak performance of the machine, and the LINPACK n and n(sub 1/2) values. Some of the results and observations can be summarized as follows: 1) All benchmarks are strongly correlated with peak performance. 2) LINPACK and EP have each a unique signature. 3) The remaining NPB can grouped into three groups as follows: (CG and IS), (LU and SP), and (MG, FT, and BT). Hence three (or four with EP) benchmarks are sufficient to characterize the overall NPB performance. Our poster presentation will follow a standard poster format, and will present the data of our statistical analysis in detail.

  17. NAS technical summaries. Numerical aerodynamic simulation program, March 1992 - February 1993

    NASA Technical Reports Server (NTRS)

    1994-01-01

    NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefitting other supercomputer centers in government and industry. The 1992-93 operational year concluded with 399 high-speed processor projects and 91 parallel projects representing NASA, the Department of Defense, other government agencies, private industry, and universities. This document provides a glimpse at some of the significant scientific results for the year.

  18. NAS technical summaries: Numerical aerodynamic simulation program, March 1991 - February 1992

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefiting other supercomputer centers in Government and industry. This report contains selected scientific results from the 1991-92 NAS Operational Year, March 4, 1991 to March 3, 1992, which is the fifth year of operation. During this year, the scientific community was given access to a Cray-2 and a Cray Y-MP. The Cray-2, the first generation supercomputer, has four processors, 256 megawords of central memory, and a total sustained speed of 250 million floating point operations per second. The Cray Y-MP, the second generation supercomputer, has eight processors and a total sustained speed of one billion floating point operations per second. Additional memory was installed this year, doubling capacity from 128 to 256 megawords of solid-state storage-device memory. Because of its higher performance, the Cray Y-MP delivered approximately 77 percent of the total number of supercomputer hours used during this year.

  19. Microencapsulation of vitamin e from palm fatty acid distillate with galactomannan and gum acacia using spray drying method

    NASA Astrophysics Data System (ADS)

    Tarigan, J. Br.; Kaban, J.; Zulmi, R.

    2018-02-01

    Vitamin E from palm fatty acid distillate (PFAD) has been encapsulated using spray drying method with gum acacia (GA) and mixed of galactomannan from Arenga pinnata (GAP) with GA as encapsulating agent. Composite films with thickness vary from 0.542 - 0.779 mm were prepared by incorporating vitamin E onto matrix of GA (7 g) with various concentration of GAP (0.1; 0.2; 0.3 and 0.4 g). The film obtained from 0.2 g GAP and 1.3 g vitamin E showed better compatibility and have viscosity similar with standard (ISO 9001:2008 and ISO 22000:2005). That composition was used for spray drying method rendering micro-particle size 11 µm and the particle had spherical shape. Although the increment of GAP decreasing moisture content and the particle size from 16 µm to 11 µm, the yield of microcapsule, encapsulation efficiency, the amount of vitamin E absorbed and oxidation stability of vitamin E were increased.

  20. Evaluation of mosquito larvicidal activity of fruit extracts of Acacia auriculiformis against the Japanese encephalitis vector Culex vishnui.

    PubMed

    Barik, Mousumi; Rawani, Anjali; Laskar, Subrata; Chandra, Goutam

    2018-02-19

    The larvicidal potentiality of crude and ethyl acetate extracts of fruits of Acacia auriculiformis was investigated against all the larval instars of JE vector Culex vishnui. The crude extracts showed good results against all the larval instars with highest mortality at 0.09%. Highest mortality was found at 300 ppm of ethyl acetate extract. Lowest LC 50 value was obtained at 72 h for third instar larvae. Non target organisms tested, showed no to very less mortality to ethyl acetate solvent extract. Presence of N-H stretching, a C=O stretching, C=C and C-N stretching vibrations of secondary amide or amine group were confirmed from IR analysis. GC-MS analysis revealed the presence of three compounds namely Ethane 2-chloro-1,1-dimethoxy, Acetic acid, 1-methyl ether ester and [4-[1-[3,5-Dimethyl-4[(trimethylsilyl)oxy)phenyl]-1,3-dimethylbutyl)-2,6dimethylphenoxy)(trimethyl) silane, responsible for mosquito larval death.

  1. Design handbook : energy efficiency and water conservation in NAS facilities

    DOT National Transportation Integrated Search

    1997-09-30

    This handbook was created to provide definitive energy efficiency and water conservation design criteria for the design of NAS facilities. FAA-HDBK-001 provides implementation strategies and tools to comply with E.O. 12902, Energy and Water Conservat...

  2. Benefits of a Unified LaSRS++ Simulation for NAS-Wide and High-Fidelity Modeling

    NASA Technical Reports Server (NTRS)

    Glaab, Patricia; Madden, Michael

    2014-01-01

    The LaSRS++ high-fidelity vehicle simulation was extended in 2012 to support a NAS-wide simulation mode. Since the initial proof-of-concept, the LaSRS++ NAS-wide simulation is maturing into a research-ready tool. A primary benefit of this new capability is the consolidation of the two modeling paradigms under a single framework to save cost, facilitate iterative concept testing between the two tools, and to promote communication and model sharing between user communities at Langley. Specific benefits of each type of modeling are discussed along with the expected benefits of the unified framework. Current capability details of the LaSRS++ NAS-wide simulations are provided, including the visualization tool, live data interface, trajectory generators, terminal routing for arrivals and departures, maneuvering, re-routing, navigation, winds, and turbulence. The plan for future development is also described.

  3. UAS Integration in the NAS Project - FY 14 Annual Review

    NASA Technical Reports Server (NTRS)

    Grindle, Laurie; Randall, Debra; Hackenberg, Davis

    2014-01-01

    This briefing gives insight into the research activities and efforts being executed in order to integrate unmanned aircraft systems into the national airspace system. This briefing is to inform others of the UAS-NAS Projects progress and future directions.

  4. DOE Radiation Research Program is floundering - NAS

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

    Lobsenz, G.

    1994-04-20

    The Energy Department's radiation health effects research program is floundering in a morass of administrative confusion due to an ill-considered 1990 joint management agreement between DOE and the Health and Human Services Department, a National Academy of Sciences panel says. The NAS panel said the [open quotes]administrative difficulties[close quotes] created by the DOE-HHS agreement appear to be [open quotes]stifling creativity and efficiency within DOE's Epidemiology Research Program, delaying the completion and publication of research.[close quotes] The panel also expressed concern that DOE has failed to adequately fund or staff its health research office, and that the department had no mastermore » research plan to identify research needs or set forth uniform, scientifically rigorous data collection procedures. The panel said DOE's lack of commitment was particularly evident in its failure to set up an effective health surveillance program for its nuclear work force. In addition, the panel said DOE had fallen short on promises to create a comprehensive computer bank of health research data that would be continually updated with new information gleaned from an ongoing worker surveillance program. While recommending enhancements, the NAS panel emphasized that DOE's health research program would not be able to function effectively until the department revamped its joint management agreement with HHS.« less

  5. Meeting of Experts on NASA's Unmanned Aircraft System (UAS) Integration in the National Airspace Systems (NAS) Project

    NASA Technical Reports Server (NTRS)

    Wolfe, Jean; Bauer, Jeff; Bixby, C.J.; Lauderdale, Todd; Shively, Jay; Griner, James; Hayhurst, Kelly

    2010-01-01

    Topics discussed include: Aeronautics Research Mission Directorate Integrated Systems Research Program (ISRP) and UAS Integration in the NAS Project; UAS Integration into the NAS Project; Separation Assurance and Collision Avoidance; Pilot Aircraft Interface Objectives/Rationale; Communication; Certification; and Integrated Tests and Evaluations.

  6. Purification of a PHA-like chitin-binding protein from Acacia farnesiana seeds: a time-dependent oligomerization protein.

    PubMed

    Santi-Gadelha, T; Rocha, B A M; Oliveira, C C; Aragão, K S; Marinho, E S; Gadelha, C A A; Toyama, M H; Pinto, V P T; Nagano, C S; Delatorre, P; Martins, J L; Galvani, F R; Sampaio, A H; Debray, H; Cavada, B S

    2008-07-01

    A lectin-like protein from the seeds of Acacia farnesiana was isolated from the albumin fraction, characterized, and sequenced by tandem mass spectrometry. The albumin fraction was extracted with 0.5 M NaCl, and the lectin-like protein of A. farnesiana (AFAL) was purified by ion-exchange chromatography (Mono-Q) followed by chromatofocusing. AFAL agglutinated rabbit erythrocytes and did not agglutinate human ABO erythrocytes either native or treated with proteolytic enzymes. In sodium dodecyl sulfate gel electrophoresis under reducing and nonreducing conditions, AFAL separated into two bands with a subunit molecular mass of 35 and 50 kDa. The homogeneity of purified protein was confirmed by chromatofocusing with a pI = 4.0 +/- 0.5. Molecular exclusion chromatography confirmed time-dependent oligomerization in AFAL, in accordance with mass spectrometry analysis, which confers an alteration in AFAL affinity for chitin. The protein sequence was obtained by a liquid chromatography quadrupole time-of-flight experiment and showed that AFAL has 68% and 63% sequence similarity with lectins of Phaseolus vulgaris and Dolichos biflorus, respectively.

  7. QNAP 1263U Network Attached Storage (NAS)/ Storage Area Network (SAN) Device Users Guide

    DTIC Science & Technology

    2016-11-01

    standard Ethernet network. Operating either a NAS or SAN is vital for the integrity of the data stored on the drives found in the device. Redundant...speed of the network itself. Many standards are in place for transferring data, including more standard ones such as File Transfer Protocol and Server ...following are the procedures for connecting to the NAS administrative web page: 1) Open a web browser and browse to 192.168.40.8:8080. 2) Enter the

  8. Implementation of the NAS Parallel Benchmarks in Java

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael A.; Schultz, Matthew; Jin, Haoqiang; Yan, Jerry; Biegel, Bryan (Technical Monitor)

    2002-01-01

    Several features make Java an attractive choice for High Performance Computing (HPC). In order to gauge the applicability of Java to Computational Fluid Dynamics (CFD), we have implemented the NAS (NASA Advanced Supercomputing) Parallel Benchmarks in Java. The performance and scalability of the benchmarks point out the areas where improvement in Java compiler technology and in Java thread implementation would position Java closer to Fortran in the competition for CFD applications.

  9. Three Mississippi ecotypes of wetland plants

    Treesearch

    Janet M. Grabowski

    2000-01-01

    In 1996, the USDA-Natural Resources Conservation Service (NRCS) Jamie L. Whitten Plant Materials Center (PMC) released three locally collected, source-identified wetland plants. Indian Bayou source powdery thalia (Thalia dealbata Fraser ex Roscoe) and Leflore source creeping burhead [Echinodorus cordifolius (L.) Griseb.] were...

  10. Unstructured Adaptive (UA) NAS Parallel Benchmark. Version 1.0

    NASA Technical Reports Server (NTRS)

    Feng, Huiyu; VanderWijngaart, Rob; Biswas, Rupak; Mavriplis, Catherine

    2004-01-01

    We present a complete specification of a new benchmark for measuring the performance of modern computer systems when solving scientific problems featuring irregular, dynamic memory accesses. It complements the existing NAS Parallel Benchmark suite. The benchmark involves the solution of a stylized heat transfer problem in a cubic domain, discretized on an adaptively refined, unstructured mesh.

  11. UAS Integration in the NAS Project: Integrated Test and Evaluation (IT&E) Flight Test 3. Revision E

    NASA Technical Reports Server (NTRS)

    Marston, Michael

    2015-01-01

    The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration into the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability, Human Systems Integration (HSI), and Communication to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Sense and Avoid (SAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including the integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project will conduct a series of Human-in-the-Loop and Flight Test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity and complexity of the previous tests and

  12. Compositional dependence of the band gap in Ga(NAsP) quantum well heterostructures

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

    Jandieri, K., E-mail: kakhaber.jandieri@physik.uni-marburg.de; Ludewig, P.; Wegele, T.

    We present experimental and theoretical studies of the composition dependence of the direct band gap energy in Ga(NAsP)/GaP quantum well heterostructures grown on either (001) GaP- or Si-substrates. The theoretical description takes into account the band anti-crossing model for the conduction band as well as the modification of the valence subband structure due to the strain resulting from the pseudomorphic epitaxial growth on the respective substrate. The composition dependence of the direct band gap of Ga(NAsP) is obtained for a wide range of nitrogen and phosphorus contents relevant for laser applications on Si-substrate.

  13. Structural, textural and morphological characteristics of tannins from Acacia mearnsii encapsulated using sol-gel methods: Applications as antimicrobial agents.

    PubMed

    Dos Santos, Cristiane; Vargas, Álvaro; Fronza, Ney; Dos Santos, João Henrique Zimnoch

    2017-03-01

    Tannins from Acacia mearnsii were encapsulated using four different sol-gel methods acid (SGAR), basic (SGBR), silicate (SGSR) and non-hydrolytic (SGNHR) routes. The hybrid materials were analyzed using a set of techniques to characterize their structure, texture and morphology. The antimicrobial performance of the encapsulated materials was evaluated against different microorganisms (Staphylococcus aureus, Escherichia coli, Aspergillus niger and Candida sp.). The data showed that the encapsulation route significantly affects the characteristics of the resulting hybrid materials. Better functional performances were obtained using the silicate route, which produced mesoporous materials with a small surface area (0.96m 2 g -1 ) and small particle size (<1nm). These characteristics promoted the gradual release of tannins in an aqueous medium and improved their interactions with microorganisms. Furthermore, the process demonstrated the preservation of tannins after synthesis and increased antimicrobial activity (via a controlled tannin release), as demonstrated by the moderate activity against filamentous fungi and yeast. Copyright © 2016. Published by Elsevier B.V.

  14. The Exotic Legume Tree Species Acacia holosericea Alters Microbial Soil Functionalities and the Structure of the Arbuscular Mycorrhizal Community▿

    PubMed Central

    Remigi, P.; Faye, A.; Kane, A.; Deruaz, M.; Thioulouse, J.; Cissoko, M.; Prin, Y.; Galiana, A.; Dreyfus, B.; Duponnois, R.

    2008-01-01

    The response of microbial functional diversity as well as its resistance to stress or disturbances caused by the introduction of an exotic tree species, Acacia holosericea, ectomycorrhized or not with Pisolithus albus, was examined. The results show that this ectomycorrhizal fungus promotes drastically the growth of this fast-growing tree species in field conditions after 7 years of plantation. Compared to the crop soil surrounding the A. holosericea plantation, this exotic tree species, associated or not with the ectomycorrhizal symbiont, induced strong modifications in soil microbial functionalities (assessed by measuring the patterns of in situ catabolic potential of microbial communities) and reduced soil resistance in response to increasing stress or disturbance (salinity, temperature, and freeze-thaw and wet-dry cycles). In addition, A. holosericea strongly modified the structure of arbuscular mycorrhizal fungus communities. These results show clearly that exotic plants may be responsible for important changes in soil microbiota affecting the structure and functions of microbial communities. PMID:18203858

  15. Self-assembled GaInNAs/GaAsN quantum dot lasers: solid source molecular beam epitaxy growth and high-temperature operation

    PubMed Central

    Liu, CY; Sun, ZZ; Yew, KC

    2006-01-01

    Self-assembled GaInNAs quantum dots (QDs) were grown on GaAs (001) substrate using solid-source molecular-beam epitaxy (SSMBE) equipped with a radio-frequency nitrogen plasma source. The GaInNAs QD growth characteristics were extensively investigated using atomic-force microscopy (AFM), photoluminescence (PL), and transmission electron microscopy (TEM) measurements. Self-assembled GaInNAs/GaAsN single layer QD lasers grown using SSMBE have been fabricated and characterized. The laser worked under continuous wave (CW) operation at room temperature (RT) with emission wavelength of 1175.86 nm. Temperature-dependent measurements have been carried out on the GaInNAs QD lasers. The lowest obtained threshold current density in this work is ∼1.05 kA/cm2from a GaInNAs QD laser (50 × 1,700 µm2) at 10 °C. High-temperature operation up to 65 °C was demonstrated from an unbonded GaInNAs QD laser (50 × 1,060 µm2), with high characteristic temperature of 79.4 K in the temperature range of 10–60 °C.

  16. UAS in the NAS Flight Test Series 3 Overview

    NASA Technical Reports Server (NTRS)

    Murphy, James R.

    2015-01-01

    The UAS Integration in the NAS Project is conducting a series of flight tests to acheive the following objectives: 1.) Validate results previously collected during project simulations with live data 2.) Evaluate TCAS IISS interoperability 3.) Test fully integrated system in a relevant live test environment 4.) Inform final DAA and C2 MOPS 5.) Reduce risk for Flight Test Series 4.

  17. Biosynthesis of silver nanoparticles using Acacia leucophloea extract and their antibacterial activity

    PubMed Central

    Murugan, Kasi; Senthilkumar, Balakrishnan; Senbagam, Duraisamy; Al-Sohaibani, Saleh

    2014-01-01

    The immense potential of nanobiotechnology makes it an intensely researched field in modern medicine. Green nanomaterial synthesis techniques for medicinal applications are desired because of their biocompatibility and lack of toxic byproducts. We report the toxic byproducts free phytosynthesis of stable silver nanoparticles (AgNPs) using the bark extract of the traditional medicinal plant Acacia leucophloea (Fabaceae). Visual observation, ultraviolet–visible spectroscopy, and transmission electron microscopy (TEM) were used to characterize the synthesized AgNPs. The visible yellow-brown color formation and surface plasmon resonance at 440 nm indicates the biosynthesis of AgNP. The TEM images show polydisperse, mostly spherical AgNP particles of 17–29 nm. Fourier transform infrared spectroscopy revealed that primary amines, aldehyde/ketone, aromatic, azo, and nitro compounds of the A. leucophloea extract may participate in the bioreduction and capping of the formed AgNPs. X-ray diffraction confirmed the crystallinity of the AgNPs. The in vitro agar well diffusion method confirmed the potential antibacterial activity of the plant extract and synthesized AgNPs against the common bacterial pathogens Staphylococcus aureus (MTCC 737), Bacillus cereus (MTCC 1272), Listeria monocytogenes (MTCC 657), and Shigella flexneri (MTCC 1475). This research combines the inherent antimicrobial activity of silver metals with the A. leucophloea extract, yielding antibacterial activity-enhanced AgNPs. This new biomimetic approach using traditional medicinal plant (A. leucophloea) barks to synthesize biocompatible antibacterial AgNPs could easily be scaled up for additional biomedical applications. These polydisperse AgNPs green-synthesized via A. leucophloea bark extract can readily be used in many applications not requiring high uniformity in particle size or shape. PMID:24876776

  18. UAS-NAS Project Demo - Mini HITL Week 2 Stats

    NASA Technical Reports Server (NTRS)

    Murphy, James R.; Fern, Lisa C.; Rorie, Robert C.; Shively, Robert; Jovic, Srboljub

    2016-01-01

    The UAS-NAS Project demo will showcase recent research efforts to ensure the interoperability between proposed UAS detect and avoid (DAA) human machine interface requirements (developed within RTCA SC-228) and existing collision avoidance displays. Attendees will be able to view the current state of the art of the DAA pilot traffic, alerting and guidance displays integrated with Traffic advisory and Collision Avoidance (TCAS) II in the UAS-NAS Project's research UAS ground control station (developed in partnership with the Air Force Research Laboratory). In addition, attendees will have the opportunity to interact with the research UAS ground control station and "fly" encounters, using the DAA and TCAS II displays to avoid simulated aircraft. The display of the advisories will be hosted on a laptop with an external 30" monitor, running the Vigilant Spirit system. DAA advisories will be generated by the JADEM software tool, connected to the system via the LVC Gateway. A repeater of the primary flight display will be shown on a 55" monitor mounted on a stand at the back of the booth to show the pilot interaction to the passersby.

  19. Greenhouse policy study from NAS

    NASA Astrophysics Data System (ADS)

    Maggs, William Ward

    The National Academy of Sciences will produce a study for the Environmental Protection Agency on policy responses to global warming. The report is due out before the end of 1990.Dan J. Evans, former U.S. Senator and former Governor of Washington, will chair a panel of the Commission on Science, Engineering, and Public Policy, a body of the councils of the NAS, National Academy of Engineering, and Institute of Medicine. Evans is a registered civil engineer and previously chaired the Pacific Northwest Electric Power and Conservation Planning Council.The 13-person panel includes AGU members Stephen Schneider of the National Center for Atmospheric Research and Robert Frosch, Vice President of Research Laboratores at General Motors Corp., Jessica Mathews, Vice President of the World Resources Institute, and Sir Crispin Tickell, the United Kingdom's Ambassador to the United Nations.

  20. Antioxidant and antigenotoxic activities in Acacia salicina extracts and its protective role against DNA strand scission induced by hydroxyl radical.

    PubMed

    Chatti, Ines Bouhlel; Boubaker, Jihed; Skandrani, Ines; Bhouri, Wissem; Ghedira, Kamel; Chekir Ghedira, Leila

    2011-08-01

    The antioxidant potency of Acacia salicina extracts was investigated. Total antioxidant capacity was determined using an ABTS(+) assay. Superoxide radical scavenging was measured using riboflavin-light-nitro blue tetrazolium (NBT) assay. In addition, the content of phenols, total flavonoids and sterols were measured in the tested extracts. The petroleum ether exhibited a potent scavenging activity toward ABTS radical cations. Whereas, chloroform extract showed the highest activity against superoxides radicals and was also able to protect pKS plasmid DNA against hydroxyl radicals induced DNA damages. The antimutagenicity of these extracts was assayed using the Ames assay against Salmonella typhimurium TA98 and S. typhimurium TA 1535 tester strains at different concentrations. These extracts decreased significantly the mutagenecity induced by sodium azide (SA) and 4-nitro-o-phenylenediamine (NOP). The antioxidant and antimutagenecity activities exhibited by A. salicina depended on the chemical composition of the tested extracts. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Gum acacia mitigates genetic damage in adenine-induced chronic renal failure in rats.

    PubMed

    Ali, B H; Al Balushi, K; Al-Husseini, I; Mandel, P; Nemmar, A; Schupp, N; Ribeiro, D A

    2015-12-01

    Subjects with chronic renal failure (CRF) exhibit oxidative genome damage, which may predispose to carcinogenesis, and Gum acacia (GumA) ameliorates this condition in humans and animals. We evaluated here renal DNA damage and urinary excretion of four nucleic acid oxidation adducts namely 8-oxoguanine (8-oxoGua), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), 8-oxoguanosine (8-oxoGuo) and 8-hydroxy-2-deoxyguanisone (8-OHdg) in rats with adenine (ADE)-induced CRF with and without GumA treatment. Twenty-four rats were divided into four equal groups and treated for 4 weeks. The first group was given normal food and water (control). The second group was given normal food and GumA (15% w/v) in drinking water. The third group was fed powder diet containing adenine (ADE) (0·75% w/w in feed). The fourth group was fed like in the third group, plus GumA in drinking water (15%, w/v). ADE feeding induced CRF (as measured by several physiological, biochemical and histological indices) and also caused a significant genetic damage and significant decreases in urinary 8-oxo Gua and 8-oxoGuo, but not in the other nucleic acids. However, concomitant GumA treatment reduced the level of genetic damage in kidney cells as detected by Comet assay and significantly reversed the effect of adenine on urinary 8-oxoGuo. Treatment with GumA is able to mitigate genetic damage in renal tissues of rats with ADE-induced CRF. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.

  2. Functional Requirements Document for HALE UAS Operations in the NAS: Step 1. Version 3

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The purpose of this Functional Requirements Document (FRD) is to compile the functional requirements needed to achieve the Access 5 Vision of "operating High Altitude, Long Endurance (HALE) Unmanned Aircraft Systems (UAS) routinely, safely, and reliably in the national airspace system (NAS)" for Step 1. These functional requirements could support the development of a minimum set of policies, procedures and standards by the Federal Aviation Administration (FAA) and various standards organizations. It is envisioned that this comprehensive body of work will enable the FAA to establish and approve regulations to govern safe operation of UAS in the NAS on a routine or daily "file and fly" basis. The approach used to derive the functional requirements found within this FRD was to decompose the operational requirements and objectives identified within the Access 5 Concept of Operations (CONOPS) into the functions needed to routinely and safely operate a HALE UAS in the NAS. As a result, four major functional areas evolved to enable routine and safe UAS operations for an on-demand basis in the NAS. These four major functions are: Aviate, Navigate, Communicate, and Avoid Hazards. All of the functional requirements within this document can be directly traceable to one of these four major functions. Some functions, however, are traceable to several, or even all, of these four major functions. These cross-cutting functional requirements support the "Command / Control: function as well as the "Manage Contingencies" function. The requirements associated to these high-level functions and all of their supporting low-level functions are addressed in subsequent sections of this document.

  3. MALDI-TOF MS analysis of condensed tannins with potent antioxidant activity from the leaf, stem bark and root bark of Acacia confusa.

    PubMed

    Wei, Shu-Dong; Zhou, Hai-Chao; Lin, Yi-Ming; Liao, Meng-Meng; Chai, Wei-Ming

    2010-06-15

    The structures of the condensed tannins from leaf, stem bark and root bark of Acacia confusa were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, and their antioxidant activities were measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing/antioxidant power (FRAP) assays. The results showed that the condensed tannins from stem bark and root bark include propelargonidin and procyanidin, and the leaf condensed tannins include propelargonidin, procyanidin and prodelphinidin, all with the procyanidin dominating. The condensed tannins had different polymer chain lengths, varying from trimers to undecamers for leaf and root bark and to dodecamers for stem bark. The condensed tannins extracted from the leaf, stem bark and root bark all showed a very good DPPH radical scavenging activity and ferric reducing power.

  4. The CAS-NAS forum for new leaders in space science

    NASA Astrophysics Data System (ADS)

    Smith, David H.

    The space science community is thoroughly international, with numerous nations now capable of launching scientific payloads into space either independently or in concert with others. As such, it is important for national space-science advisory groups to engage with like-minded groups in other spacefaring nations. The Space Studies Board of the US National Academy of Sciences' (NAS') National Research Council has provided scientific and technical advice to NASA for more than 50 years. Over this period, the Board has developed important multilateral and bilateral partnerships with space scientists around the world. The primary multilateral partner is COSPAR, for which the Board serves as the US national committee. The Board's primary bilateral relationship is with the European Science Foundation’s European Space Science Committee. Burgeoning Chinese space activities have resulted in several attempts in the past decade to open a dialogue between the Board and space scientists in China. On each occasion, the external political environment was not conducive to success. The most recent efforts to engage the Chinese space researchers began in 2011 and have proved particularly successful. Although NASA is currently prohibited from engaging in bilateral activities with China, the Board has established a fruitful dialogue with its counterpart in the Chinese Academy of Sciences (CAS). A joint NAS-CAS activity, the Forum for New Leaders in Space Science, has been established to provide opportunities for a highly select group of young space scientists from China and the United States to discuss their research activities in an intimate and collegial environment at meetings to be held in both nations. The presentation will describe the current state of US-China space relations, discuss the goals of the joint NAS-CAS undertaking and report on the activities at the May, 2014, Forum in Beijing and the planning for the November, 2014, Forum in Irvine, California.

  5. UAS in the NAS - Analysis Results and Recommendations for Integration of CNPC and ATC Communications Simulation Report

    NASA Technical Reports Server (NTRS)

    Kubat, Gregory

    2016-01-01

    This report addresses a deliverable to the UAS-in-the-NAS project for recommendations for integration of CNPC and ATC communications based on analysis results from modeled radio system and NAS-wide UA communication architecture simulations. For each recommendation, a brief explanation of the rationale for its consideration is provided with any supporting results obtained or observed in our simulation activity.

  6. Turning over a new 'leaf': multiple functional significances of leaves versus phyllodes in Hawaiian Acacia koa.

    PubMed

    Pasquet-Kok, Jessica; Creese, Christine; Sack, Lawren

    2010-12-01

    Hawaiian endemic tree Acacia koa is a model for heteroblasty with bipinnately compound leaves and phyllodes. Previous studies suggested three hypotheses for their functional differentiation: an advantage of leaves for early growth or shade tolerance, and an advantage of phyllodes for drought tolerance. We tested the ability of these hypotheses to explain differences between leaf types for potted plants in 104 physiological and morphological traits, including gas exchange, structure and composition, hydraulic conductance, and responses to varying light, intercellular CO(2) , vapour pressure deficit (VPD) and drought. Leaf types were similar in numerous traits including stomatal pore area per leaf area, leaf area-based gas exchange rates and cuticular conductance. Each hypothesis was directly supported by key differences in function. Leaves had higher mass-based gas exchange rates, while the water storage tissue in phyllodes contributed to greater capacitance per area; phyllodes also showed stronger stomatal closure at high VPD, and higher maximum hydraulic conductance per area, with stronger decline during desiccation and recovery with rehydration. While no single hypothesis completely explained the differences between leaf types, together the three hypotheses explained 91% of differences. These findings indicate that the heteroblasty confers multiple benefits, realized across different developmental stages and environmental contexts. © 2010 Blackwell Publishing Ltd.

  7. Supercomputing 2002: NAS Demo Abstracts

    NASA Technical Reports Server (NTRS)

    Parks, John (Technical Monitor)

    2002-01-01

    The hyperwall is a new concept in visual supercomputing, conceived and developed by the NAS Exploratory Computing Group. The hyperwall will allow simultaneous and coordinated visualization and interaction of an array of processes, such as a the computations of a parameter study or the parallel evolutions of a genetic algorithm population. Making over 65 million pixels available to the user, the hyperwall will enable and elicit qualitatively new ways of leveraging computers to accomplish science. It is currently still unclear whether we will be able to transport the hyperwall to SC02. The crucial display frame still has not been completed by the metal fabrication shop, although they promised an August delivery. Also, we are still working the fragile node issue, which may require transplantation of the compute nodes from the present 2U cases into 3U cases. This modification will increase the present 3-rack configuration to 5 racks.

  8. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project KDP-C Review

    NASA Technical Reports Server (NTRS)

    Grindle, Laurie; Sakahara, Robert; Hackenberg, Davis; Johnson, William

    2017-01-01

    The topics discussed are the UAS-NAS project life-cycle and ARMD thrust flow down, as well as the UAS environments and how we operate in those environments. NASA's Armstrong Flight Research Center at Edwards, CA, is leading a project designed to help integrate unmanned air vehicles into the world around us. The Unmanned Aircraft Systems Integration in the National Airspace System project, or UAS in the NAS, will contribute capabilities designed to reduce technical barriers related to safety and operational challenges associated with enabling routine UAS access to the NAS. The project falls under the Integrated Systems Research Program office managed at NASA Headquarters by the agency's Aeronautics Research Mission Directorate. NASA's four aeronautics research centers - Armstrong, Ames Research Center, Langley Research Center, and Glenn Research Center - are part of the technology development project. With the use and diversity of unmanned aircraft growing rapidly, new uses for these vehicles are constantly being considered. Unmanned aircraft promise new ways of increasing efficiency, reducing costs, enhancing safety and saving lives 460265main_ED10-0132-16_full.jpg Unmanned aircraft systems such as NASA's Global Hawks (above) and Predator B named Ikhana (below), along with numerous other unmanned aircraft systems large and small, are the prime focus of the UAS in the NAS effort to integrate them into the national airspace. Credits: NASA Photos 710580main_ED07-0243-37_full.jpg The UAS in the NAS project envisions performance-based routine access to all segments of the national airspace for all unmanned aircraft system classes, once all safety-related and technical barriers are overcome. The project will provide critical data to such key stakeholders and customers as the Federal Aviation Administration and RTCA Special Committee 203 (formerly the Radio Technical Commission for Aeronautics) by conducting integrated, relevant system-level tests to adequately address

  9. Theoretical studies of optical gain tuning by hydrostatic pressure in GaInNAs/GaAs quantum wells

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

    Gladysiewicz, M.; Wartak, M. S.; Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5

    In order to describe theoretically the tuning of the optical gain by hydrostatic pressure in GaInNAs/GaAs quantum wells (QWs), the optical gain calculations within kp approach were developed and applied for N-containing and N-free QWs. The electronic band structure and the optical gain for GaInNAs/GaAs QW were calculated within the 10-band kp model which takes into account the interaction of electron levels in the QW with the nitrogen resonant level in GaInNAs. It has been shown that this interaction increases with the hydrostatic pressure and as a result the optical gain for GaInNAs/GaAs QW decreases by about 40% and 80%more » for transverse electric and transverse magnetic modes, respectively, for the hydrostatic pressure change from 0 to 40 kilobars. Such an effect is not observed for N-free QWs where the dispersion of electron and hole energies remains unchanged with the hydrostatic pressure. This is due to the fact that the conduction and valence band potentials in GaInAs/GaAs QW scale linearly with the hydrostatic pressure.« less

  10. NAS Requirements Checklist for Job Queuing/Scheduling Software

    NASA Technical Reports Server (NTRS)

    Jones, James Patton

    1996-01-01

    The increasing reliability of parallel systems and clusters of computers has resulted in these systems becoming more attractive for true production workloads. Today, the primary obstacle to production use of clusters of computers is the lack of a functional and robust Job Management System for parallel applications. This document provides a checklist of NAS requirements for job queuing and scheduling in order to make most efficient use of parallel systems and clusters for parallel applications. Future requirements are also identified to assist software vendors with design planning.

  11. Optical Properties of A GaInNAs Multi-Quantum Well Semiconductor

    NASA Astrophysics Data System (ADS)

    Hughes, Timothy S.; Ren, Shang-Fen; Jiang, De-Sheng; Xiaogan, Liang

    2002-03-01

    Optoelectronic devices used today depend on lasers that have wavelengths in the optical fiber transmission window of 1.3 to 1.55 micrometers. When using GaAs substrate semiconductor lasers, we typically see this range of light emission. Quaternary materials, such as GaInNAs grown on this substrate, not only allow us to control the output wavelength, but it also allows us to manipulate the lattice constant. Further research has potential to produce low-costing highly efficient Vertical Cavity Surface Emitting Lasers (VCSEL). Using a Fourier-Transform Spectrometer, a method of using a Michelson Interferometer to measure the interference between two coherent beams, we measured and analyzed the photoluminescence spectra of a GaInNAs multi-quantum well semiconductor, grown using the Molecular Beam Epitaxy (MBE) growth technique. The experiments of this research were carried out in an undergraduate international research experience at the Chinese Semiconductor Institute supported by the Division of International Programs of NSF.

  12. A Descriptive Analysis of Nursing Staff Behaviors in a Teaching Nursing Home: Differences among NAs, LPNs, and RNs.

    ERIC Educational Resources Information Center

    Burgio, Louis D.; And Others

    1990-01-01

    Various staff behaviors in nursing home were sampled 7 times a day, 5 days a week over 37 months and were coded separately for registered nurses (RNs), licensed practical nurses (LPNs), and nurses' aides (NAs). Found LPNs displayed significantly more patient care behaviors and NAs significantly more nonwork behaviors than other nursing staff. RNs…

  13. Concepts of Integration for UAS Operations in the NAS

    NASA Technical Reports Server (NTRS)

    Consiglio, Maria C.; Chamberlain, James P.; Munoz, Cesar A.; Hoffler, Keith D.

    2012-01-01

    One of the major challenges facing the integration of Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is the lack of an onboard pilot that can comply with the legal requirement identified in the US Code of Federal Regulations (CFR) that pilots see and avoid other aircraft. UAS will be expected to demonstrate the means to perform the function of see and avoid while preserving the safety level of the airspace and the efficiency of the air traffic system. This paper introduces a Sense and Avoid (SAA) concept for integration of UAS into the NAS that is currently being developed by the National Aeronautics and Space Administration (NASA) and identifies areas that require additional experimental evaluation to further inform various elements of the concept. The concept design rests on interoperability principles that take into account both the Air Traffic Control (ATC) environment as well as existing systems such as the Traffic Alert and Collision Avoidance System (TCAS). Specifically, the concept addresses the determination of well clear values that are large enough to avoid issuance of TCAS corrective Resolution Advisories, undue concern by pilots of proximate aircraft and issuance of controller traffic alerts. The concept also addresses appropriate declaration times for projected losses of well clear conditions and maneuvers to regain well clear separation.

  14. The role of N-H complexes in the control of localized center recombination in hydrogenated GaInNAs (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Whiteside, Vincent R.; Fukuda, Miwa; Estes, Nicholas J.; Wang, Bin; Brown, Collin R.; Hossain, Khalid; Golding, Terry D.; Leroux, Mathieu; Al Khalfioui, Mohamed; Tischler, Joseph G.; Ellis, Chase T.; Glaser, Evan R.; Sellers, Ian R.

    2017-04-01

    A significant improvement in the quality of dilute nitrides has recently led to the ability to reveal depletion widths in excess of 1 μm at 1 eV [1]. The real viability of dilute nitrides for PV has been recently demonstrated with the reporting of a record efficiency of 43.5% from a 4J MJSC including GaInNAs(Sb) [2]. Despite the progress made, these materials remain poorly understood and work continues to improve their lifetime and reproducibility. We have investigated the possibility of improving the functionality of GaInNAs using hydrogenation to selectively passivate mid-gap defects, while preserving the substitutional nitrogen. Temperature dependent photoluminescence measurements of the intrinsic region of a GaInNAs p-i-n solar cell show a classic "s-shape" associated with localization prior to hydrogenation. No sign of this "s-shape" is evident after hydrogenation, despite the retention of substitutional nitrogen as evidenced by the band absorption of 1 eV. The absence of an "s-shape" at low-temperature in hydrogenated GaInNAs is rather curious since, even in high quality nitrides this behavior is due to the emission of isoelectronic centers created via N-As substitution [3]. The potential origins of this behavior will be discussed. The promise of this process for GaInNAs solar cells was demonstrated by a three-fold improvement in the performance of a hydrogenated device with respect to an as-grown reference [4]. [1] "Wide-depletion width GaInNAs solar cells by thermal annealing," I. R. Sellers, W-S. Tan, K. Smith, S. Hooper, S. Day and M. Kauer, Applied Physics Letters 99, 151111 (2011) [2] "43.5% efficient lattice matched solar cells," M. Wiemer, V. Sabnis, and H. Yuen, Proc. SPIE 8108, 810804 (2011) [3]"Probing the nature of carrier localization in GaInNAs, epilayers using optical methods," T. Ysai, B. Barman, T. Scarce, G. Lindberg, M. Fukuda, V. R. Whiteside, J. C. Keay, M. B. Johnson, I. R. Sellers, M. Al Khalfioui, M. Leroux, B. A. Weinstein and A

  15. Neonatal Abstinence Syndrome (NAS): Transitioning Methadone Treated Infants From An Inpatient to an Outpatient Setting

    PubMed Central

    Backes, Carl H.; Backes, Carl R.; Gardner, Debra; Nankervis, Craig A.; Giannone, Peter J.; Cordero, Leandro

    2013-01-01

    Background Each year in the US approximately 50,000 neonates receive inpatient pharmacotherapy for the treatment of neonatal abstinence syndrome (NAS). Objective To compare the safety and efficacy of a traditional inpatient only approach with a combined inpatient and outpatient methadone treatment program. Design/Methods Retrospective review (2007-9). Infants were born to mothers maintained on methadone or buprenorphine in an antenatal substance abuse program. All infants received methadone for NAS treatment as inpatient. Methadone weaning for the traditional group (75 pts) was inpatient while the combined group (46 pts) was outpatient. Results Infants in the traditional and combined groups were similar in demographics, obstetrical risk factors, birth weight, GA and the incidence of prematurity (34 & 31%). Hospital stay was shorter in the combined than in the traditional group (13 vs 25d; p < 0.01). Although the duration of treatment was longer for infants in the combined group (37 vs 21d, p<0.01), the cumulative methadone dose was similar (3.6 vs 3.1mg/kg, p 0.42). Follow-up: Information was available for 80% of infants in the traditional and 100% of infants in the combined group. All infants in the combined group were seen ≤ 72 hours from hospital discharge. Breast feeding was more common among infants in the combined group (24 vs. 8% p<0.05). Following discharge there were no differences between the two groups in hospital readmissions for NAS. Prematurity (<37w GA) was the only predictor for hospital readmission for NAS in both groups (p 0.02, OR 5). Average hospital cost for each infant in the combined group was $13,817 less than in the traditional group. Conclusions A combined inpatient and outpatient methadone treatment in the management of NAS decreases hospital stay and substantially reduces cost. Additional studies are needed to evaluate the potential long term benefits of the combined approach on infants and their families. PMID:21852772

  16. NAS (Host/ARTS) IIIA to VME Modem Interface ATC Interface Hardware Manual

    DOT National Transportation Integrated Search

    1990-10-01

    This document is reference material for personnel using the National Airspace : System (NAS) (HOST or ARTS IIIA) Air Traffic Control (ATC) Interface Subsystem. : It was originally developed to be part of the Data Link Test and Analysis System : (DATA...

  17. The temperature dependence of atomic incorporation characteristics in growing GaInNAs films

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

    Li, Jingling; Gao, Fangliang; Wen, Lei

    We have systematically studied the temperature dependence of incorporation characteristics of nitrogen (N) and indium (In) in growing GaInNAs films. With the implementation of Monte-Carlo simulation, the low N adsorption energy (−0.10 eV) is demonstrated. To understand the atomic incorporation mechanism, temperature dependence of interactions between Group-III and V elements are subsequently discussed. We find that the In incorporation behaviors rather than that of N are more sensitive to the T{sub g}, which can be experimentally verified by exploring the compositional modulation and structural changes of the GaInNAs films by means of high-resolution X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope,more » and secondary ion mass spectroscopy.« less

  18. Shadow Mode Assessment Using Realistic Technologies for the National Airspace (SMART NAS)

    NASA Technical Reports Server (NTRS)

    Kopardekar, Parimal H.

    2014-01-01

    Develop a simulation and modeling capability that includes: (a) Assessment of multiple parallel universes, (b) Accepts data feeds, (c) Allows for live virtual constructive distribute environment, (d) Enables integrated examinations of concepts, algorithms, technologies and National Airspace System (NAS) architectures.

  19. Strain relaxation induced surface morphology of heterogeneous GaInNAs layers grown on GaAs substrate

    NASA Astrophysics Data System (ADS)

    Gelczuk, Ł.; Jóźwiak, G.; Moczała, M.; Dłużewski, P.; Dąbrowska-Szata, M.; Gotszalk, T. P.

    2017-07-01

    The partially-relaxed heterogeneous GaInNAs layers grown on GaAs substrate by atmospheric pressure vapor phase epitaxy (AP-MOVPE) were investigated by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The planar-view TEM image shows a regular 2D network of misfit dislocations oriented in two orthogonal 〈1 1 0〉 crystallographic directions at the (0 0 1) layer interface. Moreover, the cross-sectional view TEM image reveals InAs-rich and V-shaped precipitates in the near surface region of the GaInNAs epitaxial layer. The resultant undulating surface morphology, known as a cross-hatch pattern, is formed as observed by AFM. The numerical analysis of the AFM image of the GaInNAs layer surface with the well-defined cross-hatch morphology enabled us to determine a lower bound of actual density of misfit dislocations. However, a close correspondence between the asymmetric distribution of interfacial misfit dislocations and undulating surface morphology is observed.

  20. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project - Systems Integration and Operationalization (SIO) Demonstration

    NASA Technical Reports Server (NTRS)

    Swieringa, Kurt

    2018-01-01

    The UAS-NAS Project hosted a Systems Integration Operationalization (SIO) Industry Day for the SIO Request for Information (RFI) on November 30, 2017 in San Diego, California. This presentation is being presented to the same group as a follow up regarding the progress that the UAS-NAS project has made on the SIO RFI. The presentation will be virtual with a teleconference

  1. UAS Integration in the NAS Project: Integrated Test and LVC Infrastructure

    NASA Technical Reports Server (NTRS)

    Murphy, Jim; Hoang, Ty

    2015-01-01

    Overview presentation of the Integrated Test and Evaluation sub-project of the Unmanned Aircraft System (UAS) in the National Airspace System (NAS). The emphasis of the presentation is the Live, Virtual, and Constructive (LVC) system (a broadly used name for classifying modeling and simulation) infrastructure and use of external assets and connection.

  2. Isolation, characterization and mode of antimicrobial action against Vibrio cholerae of methyl gallate isolated from Acacia farnesiana.

    PubMed

    Sánchez, E; Heredia, N; Camacho-Corona, M Del R; García, S

    2013-12-01

    The antimicrobial activity of Acacia farnesiana against Vibrio cholerae has been demonstrated; however, no information regarding its active compound or its mechanism of action has been documented. The active compound was isolated from A. farnesiana by bioassay-guided fractionation and identified as methyl gallate by nuclear magnetic resonance (NMR) techniques ((1) H NMR and (13) C NMR). The minimum bactericidal concentration (MBC) of methyl gallate and its effect on membrane integrity, cytoplasmic pH, membrane potential, ATP synthesis and gene expression of cholera toxin (ctx) from V. cholerae were determined. The MBC of methyl gallate ranged from 30 ± 1 to 50 ± 1 μg ml(-1) . Methyl gallate affected cell membrane integrity, causing a decrease in cytoplasmic pH (pHin , from 7·3 to <3·0), and membrane hyperpolarization, and ATP was no longer produced by the treated cells. However, methyl gallate did not affect ctx gene expression. Methyl gallate is a major antimicrobial compound from A. farnesiana that disturbs the membrane activity of V. cholerae. The effects of methyl gallate validate several traditional antimicrobial uses of A. farnesiana, and it is an attractive alternative to control V. cholerae. © 2013 The Society for Applied Microbiology.

  3. UAS Integration in the NAS Project: Flight Test 3 Data Analysis of JADEM-Autoresolver Detect and Avoid System

    NASA Technical Reports Server (NTRS)

    Gong, Chester; Wu, Minghong G.; Santiago, Confesor

    2016-01-01

    The Unmanned Aircraft Systems Integration in the National Airspace System project, or UAS Integration in the NAS, aims to reduce technical barriers related to safety and operational challenges associated with enabling routine UAS access to the NAS. The UAS Integration in the NAS Project conducted a flight test activity, referred to as Flight Test 3 (FT3), involving several Detect-and-Avoid (DAA) research prototype systems between June 15, 2015 and August 12, 2015 at the Armstrong Flight Research Center (AFRC). This report documents the flight testing and analysis results for the NASA Ames-developed JADEM-Autoresolver DAA system, referred to as 'Autoresolver' herein. Four flight test days (June 17, 18, 22, and July 22) were dedicated to Autoresolver testing. The objectives of this test were as follows: 1. Validate CPA prediction accuracy and detect-and-avoid (DAA, formerly known as self-separation) alerting logic in realistic flight conditions. 2. Validate DAA trajectory model including maneuvers. 3. Evaluate TCAS/DAA interoperability. 4. Inform final Minimum Operating Performance Standards (MOPS). Flight test scenarios were designed to collect data to directly address the objectives 1-3. Objective 4, inform final MOPS, was a general objective applicable to the UAS in the NAS project as a whole, of which flight test is a subset. This report presents analysis results completed in support of the UAS in the NAS project FT3 data review conducted on October 20, 2015. Due to time constraints and, to a lesser extent, TCAS data collection issues, objective 3 was not evaluated in this analysis.

  4. Survival, growth, and body residues of Hyalella azteca (Saussure) exposed to fipronil contaminated sediments from non-vegetated and vegetated microcosms

    USDA-ARS?s Scientific Manuscript database

    We assessed chronic effects of fipronil and metabolite contaminated sediments from non-vegetated and Thallia dealbata vegetated wetland microcosms on Hyalella azteca during wet and dry exposures. Mean sediment concentrations (ng g-1) ranged from 0.72-1.26, 0.01-0.69, 0.07-0.23, and 0.49-7.87 for fip...

  5. Pharmacological Assessment of the Medicinal Potential of Acacia mearnsii De Wild.: Antimicrobial and Toxicity Activities

    PubMed Central

    Olajuyigbe, Olufunmiso O.; Afolayan, Anthony J.

    2012-01-01

    Acacia mearnsii De Wild. (Fabaceae) is a medicinal plant used in the treatment of microbial infections in South Africa without scientific validation of its bioactivity and toxicity. The antimicrobial activity of the crude acetone extract was evaluated by both agar diffusion and macrobroth dilution methods while its cytotoxicity effect was assessed with brine shrimp lethality assay. The study showed that both bacterial and fungal isolates were highly inhibited by the crude extract. The MIC values for the gram-positive bacteria (78.1–312.5) μg/mL, gram-negative bacteria (39.1–625) μg/mL and fungal isolates (625–5000) μg/mL differ significantly. The bacteria were more susceptible than the fungal strains tested. The antibiosis determination showed that the extract was more (75%) bactericidal than bacteriostatic (25%) and more fungicidal (66.67%) than fungistatic (33.33%). The cytotoxic activity of the extract was observed between 31.25 μg/mL and 500 μg/mL and the LC50 value (112.36 μg/mL) indicates that the extract was nontoxic in the brine shrimp lethality assay (LC50 > 100 μg/mL). These results support the use of A. mearnsii in traditional medicine for treatment of microbial infections. The extract exhibiting significant broad spectrum antimicrobial activity and nontoxic effects has potential to yield active antimicrobial compounds. PMID:22605976

  6. Many-body design of highly strained GaInNAs electroabsorption modulators on GaInAs ternary substrates

    NASA Astrophysics Data System (ADS)

    Fujisawa, Takeshi; Arai, Masakazu; Kano, Fumiyoshi

    2010-05-01

    Electroabsorption in highly strained GaInAs and GaInNAs quantum wells (QWs) grown on GaInAs or quasi-GaInAs substrates is investigated by using microscopic many-body theory. The effects of various parameters, such as strain, barrier height, substrate composition, and temperature are thoroughly examined. It is shown that the value of the absorption coefficient strongly depends on the depth of the QWs under large bias electric field due to the small overlap integral of wave functions between the conduction and valence bands. The use of GaInNAs QWs makes the strain in the well layer very small. Further, the effective quantum-well depth is increased in GaInNAs QWs due to the anticrossing interaction between the conduction and N-resonant bands, making it possible to obtain larger absorption coefficient under large bias electric fields without using wide-band gap materials for barriers.

  7. In vitro protection of biological macromolecules against oxidative stress and in vivo toxicity evaluation of Acacia nilotica (L.) and ethyl gallate in rats

    PubMed Central

    2014-01-01

    Background Recently, enormous research has been focused on natural bioactive compounds possessing potential antioxidant and anticancer properties using cell lines and animal models. Acacia nilotica (L.) is widely distributed in Asia, Africa, Australia and Kenya. The plant is traditionally used to treat mouth, ear and bone cancer. However, reports on Acacia nilotica (L.) Wild. Ex. Delile subsp. indica (Benth.) Brenan regarding its toxicity profile is limited. Hence in this study, we investigated the antioxidant capacity and acute toxicity of ethyl gallate, a phenolic antioxidant present in the A. nilotica (L.) leaf extract. Methods The antioxidant activity of ethyl gallate against Fenton’s system (Fe3+/H2O2/ascorbic acid) generated oxidative damage to pBR322 DNA and BSA was investigated. We also studied the interaction of ethyl gallate to CT-DNA by wave scan and FTIR analysis. The amount of ethyl gallate present in the A. nilotica (L.) leaf extract was calculated using HPLC and represented in gram equivalence of ethyl gallate. The acute toxicity profile of ethyl gallate in the A. nilotica (L.) leaf extract was analyzed in albino Wistar rats. Measurement of liver and kidney function markers, total proteins and glucose were determined in the serum. Statistical analysis was done using statistical package for social sciences (SPSS) tool version 16.0. Results Ethyl gallate was found to be effective at 100 μg/mL concentration by inhibiting the free radical mediated damage to BSA and pBR322 DNA. We also found that the interaction of ethyl gallate and A. nilotica (L.) leaf extract to CT-DNA occurs through intercalation. One gram of A. nilotica (L.) leaf extract was found to be equivalent to 20 mg of ethyl gallate through HPLC analysis. Based on the acute toxicity results, A. nilotica (L.) leaf extract and ethyl gallate as well was found to be non-toxic and safe. Conclusions Results revealed no mortality or abnormal biochemical changes in vivo and the protective effect

  8. UAS Integration in the NAS Project: Detect and Avoid Display UNITED Demo

    NASA Technical Reports Server (NTRS)

    Roberts, Zachary

    2017-01-01

    This demo shows the UAS-NAS project's Vigilant Spirit Control Station developed in partnership with the U.S. Air Force Research Lab. Attendees will be able to view encounters and see how the DAA and TCAS II alerting and guidance displays are used to avoid simulated aircraft.

  9. Performance and Scalability of the NAS Parallel Benchmarks in Java

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael A.; Schultz, Matthew; Jin, Haoqiang; Yan, Jerry; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    Several features make Java an attractive choice for scientific applications. In order to gauge the applicability of Java to Computational Fluid Dynamics (CFD), we have implemented the NAS (NASA Advanced Supercomputing) Parallel Benchmarks in Java. The performance and scalability of the benchmarks point out the areas where improvement in Java compiler technology and in Java thread implementation would position Java closer to Fortran in the competition for scientific applications.

  10. NASA UAS Integration into the NAS Project: Human Systems Integration

    NASA Technical Reports Server (NTRS)

    Shively, Jay

    2016-01-01

    This presentation provides an overview of the work the Human Systems Integration (HSI) sub-project has done on detect and avoid (DAA) displays while working on the UAS (Unmanned Aircraft System) Integration into the NAS project. The most recent simulation on DAA interoperability with Traffic Collision Avoidance System (TCAS) is discussed in the most detail. The relationship of the work to the larger UAS community and next steps are also detailed.

  11. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project Subcommittee Final

    NASA Technical Reports Server (NTRS)

    Johnson, Chuck; Griner, James H.; Hayhurst, Kelly J.; Shively, Robert J.; Consiglio, Maria; Muller, Eric; Murphy, James; Kim, Sam

    2012-01-01

    UAS Integration in the NAS Project overview with details from each of the subprojects. Subprojects include: Communications, Certification, Integrated Test and Evaluation, Human Systems Integration, and Separation Assurance/Sense and Avoid Interoperability.

  12. Polyphenols isolated from Acacia mearnsii bark with anti-inflammatory and carbolytic enzyme inhibitory activities.

    PubMed

    Xiong, Jia; Grace, Mary H; Esposito, Debora; Komarnytsky, Slavko; Wang, Fei; Lila, Mary Ann

    2017-11-01

    The present study was designed to characterize the polyphenols isolated from Acacia mearnsii bark crude extract (B) and fractions (B1-B7) obtained by high-speed counter-current chromatography (HSCCC) and evaluate their anti-inflammatory and carbolytic enzymes (α-glucosidase and α-amylase) inhibitory activities. Fractions B4, B5, B6, B7 (total phenolics 850.3, 983.0, 843.9, and 572.5 mg·g -1 , respectively; proanthocyanidins 75.7, 90.5, 95.0, and 44.8 mg·g -1 , respectively) showed significant activities against reactive oxygen species (ROS), nitric oxide (NO) production, and expression of pro-inflammatory genes interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) in a lipopolysaccharide (LPS)-stimulated mouse macrophage cell line RAW 264.7. All the extracts suppressed α-glucosidase and α-amylase activities, two primary enzymes responsible for carbohydrate digestion. A. mearnsii bark samples possessed significantly stronger inhibitory effects against α-glucosidase enzyme (IC 50 of 0.4-1.4 μg·mL -1 ) than the pharmaceutical acarbose (IC 50 141.8 μg·mL -1 ). B6 and B7 (IC 50 17.6 and 11.7 μg·mL -1 , respectively) exhibited α-amylase inhibitory activity as efficacious as acarbose (IC 50 15.4 μg·mL -1 ). Moreover, B extract, at 25 µg·mL -1 , significantly decreased the non-mitochondrial oxidative burst that is often associated with inflammatory response in human monocytic macrophages. Copyright © 2017 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  13. Polar extracts from (Tunisian) Acacia salicina Lindl. Study of the antimicrobial and antigenotoxic activities

    PubMed Central

    2012-01-01

    Background Methanolic, aqueous and Total Oligomer Flavonoids (TOF)-enriched extracts obtained from the leaves of Acacia salicina 'Lindl.' were investigated for antibacterial, antimutagenic and antioxidant activities. Methods The antimicrobial activity was tested on the Gram positive and Gram negative reference bacterial strains. The Mutagenic and antimutagenic activities against direct acting mutagens, methylmethane sulfonate (MMS) and 4-nitro-o-phenylenediamine (NOPD), and indirect acting mutagens, 2-aminoanthracene (2-AA) and benzo[a]pyrene (B(a)P) were performed with S. typhimurium TA102 and TA98 assay systems. In addition, the enzymatic and nonenzymatic methods were employed to evaluate the anti-oxidative effects of the tested extracts. Results A significant effect against the Gram positive and Gram negative reference bacterial strains was observed with all the extracts. The mutagenic and antimutagenic studies revealed that all the extracts decreased the mutagenicity induced by B(a)P (7.5 μg/plate), 2-AA (5 μg/plate), MMS (1.3 mg/plate) and NOPD (10 μg/plate). Likewise, all the extracts showed an important free radical scavenging activity towards the superoxide anion generated by the xanthine/xanthine oxidase assay system, as well as high Trolox Equivalent Antioxidant Capacity (TEAC), against the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS)+• radical. TOF-enriched extract exhibited the highest protective effect against free radicals, direct acting-mutagen and metabolically activated S9-dependent mutagens. Conclusions The present study indicates that the extracts from A. salicina leaves are a significant source of compounds with the antimutagenic and antioxidant activities, and this may be useful for developing potential chemopreventive substances. PMID:22490278

  14. Topical treatment of major omphalocoele: Acacia nilotica versus povidone-iodine: A randomised controlled study

    PubMed Central

    Eltayeb, Almoutaz A.; Mostafa, Mahmoud M.

    2015-01-01

    Background: Conservative management for major omphalocoele with topical agents as escharotics therapy is well established in practice. Different agents have been used in the past, including mercurochrome and alcohol, proved later to be unsafe. The aim of this study is to evaluate the efficacy and safety of the application of Acacia nilotica paste compared to povidone-iodine solution as a primary non-surgical treatment of major omphalocoele. Patients and Methods: A double-blind, randomised study was conducted on 24 cases of major omphalocoele where they were randomly divided into two equal groups; Group A treated with topical application of A. nilotica paste and Group B treated with topical application of povidone-iodine solution. Cases with gastroschisis, ruptured major omphalocoele or minor omphalocoele were excluded from the study. The evaluating parameters were size of the fascial defect in cm, period of mechanical ventilation if needed, time required for full oral feeding tolerance, duration of hospital stay and any short- or long-term complications. Results: There was no statistical significant difference between both groups regarding their gestational or post-natal age, weight and the mean umbilical port defect. Patients from Group A tolerated full oral feeding earlier and had shorter total hospital stay duration than those from Group B, but without a statistical significant difference (P = 0.347 and 0.242, respectively). The overall mortality rate was 33.3% without a statistical significant difference between both groups (P = 0.667). Conclusions: Application of A. nilotica is a safe and effective treatment of major omphalocoele as it was associated with rapid full enteral feeding tolerance, short duration of hospital stay and low mortality rate. PMID:26712288

  15. Evaluating the Information Power Grid using the NAS Grid Benchmarks

    NASA Technical Reports Server (NTRS)

    VanderWijngaartm Rob F.; Frumkin, Michael A.

    2004-01-01

    The NAS Grid Benchmarks (NGB) are a collection of synthetic distributed applications designed to rate the performance and functionality of computational grids. We compare several implementations of the NGB to determine programmability and efficiency of NASA's Information Power Grid (IPG), whose services are mostly based on the Globus Toolkit. We report on the overheads involved in porting existing NGB reference implementations to the IPG. No changes were made to the component tasks of the NGB can still be improved.

  16. In vitro evaluation of antioxidant and cytotoxic activities of lignin fractions extracted from Acacia nilotica.

    PubMed

    Barapatre, Anand; Meena, Avtar Singh; Mekala, Sowmya; Das, Amitava; Jha, Harit

    2016-05-01

    Lignin is one of the most important phytomacromolecule with diverse therapeutic properties such as anticancer, antimicrobial, anti-inflammatory and immune-stimulatory. The present study was carried out to evaluate the in vitro antioxidant, free radical scavenging and anti-proliferative/cytotoxic activities of eleven different lignin fractions, extracted from the wood of Acacia nilotica by pressurized solvent extraction (PSE) and successive solvent extraction (SSE) methods. Results indicate that the PSE fractions have high polyphenolic content and reducing power. However, the antioxidant efficiency examined by DPPH and ABTS radical scavenging assay was higher in SSE fractions. All lignin fractions revealed a significant ability to scavenge nitric oxide, hydroxyl and superoxide radicals. The extracted lignin fractions display high ferric ion reducing capacity and also possess excellent antioxidant potential in the hydrophobic (linoleic acid) system. Fractions extracted by polar solvent has the highest iron (Fe(2+)) chelating activity as compared to other factions, indicating their effect on the redox cycling of iron. Four lignin fractions depicted higher cytotoxic potential (IC50: 2-15 μg/mL) towards breast cancer cell line (MCF-7) but were ineffective (IC50: ≥ 100 μg/mL) against normal primary human hepatic stellate cells (HHSteCs). These findings suggest that the lignin extracts of A. nilotica wood has a remarkable potential to prevent disease caused by the overproduction of radicals and also seem to be a promising candidate as natural antioxidant and anti-cancer agents. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Optimization of nas lemoore scheduling to support a growing aircraft population

    DTIC Science & Technology

    2017-03-01

    requirements, and, without knowing the other squadrons’ flight plans , creates his or her squadron’s flight schedule. Figure 2 illustrates the process each...Lemoore, they do not communicate their flight schedules among themselves; hence, the daily flight plan generated by each squadron is independently...manual process for aircraft flight scheduling at Naval Air Station (NAS) Lemoore accommodates the independent needs of 16 fighter resident squadrons as

  18. The potential carbon benefit of reforesting Hawai‘i Island non-native grasslands with endemic Acacia koa trees

    USGS Publications Warehouse

    Selmants, Paul; Sleeter, Benjamin M.; Koch, Nicholas; Friday, James B.; Ohara, Rebekah Dickens; Friday, James B.

    2016-01-01

    Large areas of forest in the tropics have been cleared and converted to pastureland. Hawai‘i Island is no exception, with over 100,000 ha of historically forested land now dominated by non-native grasses. Passive forest restoration has been unsuccessful because these grasslands tend to persist even after grazers have been removed, yet active outplanting of native tree species can be cost-prohibitive at the landscape scale. It is therefore essential to seek co-benefits of forest restoration to defray costs, such as accredited carbon offsets from increased carbon sequestration. We developed a reforestation scenario for non-native grasslands on Hawai‘i Island by outplanting endemic koa (Acacia koa) trees paid for with carbon offsets via the California Cap and Trade Program. This scenario entails reforesting 53,531 ha of non-native grassland at 2500 ha y-1 over 22 years. We estimated planting costs at \\$6,178 ha-1, a total cost of approximately \\$331,000,000. We used the Land Use and Carbon Simulator (LUCAS) model to estimate island-wide ecosystem carbon sequestration with and without koa reforestation using 100 Monte Carlo simulations per year over a 60-year period. Income from carbon offsets was set at \\$13.57 per ton of CO2 equivalent, the current California Cap and Trade Program carbon market price.

  19. Web Prep: How to Prepare NAS Reports For Publication on the Web

    NASA Technical Reports Server (NTRS)

    Walatka, Pamela; Balakrishnan, Prithika; Clucas, Jean; McCabe, R. Kevin; Felchle, Gail; Brickell, Cristy

    1996-01-01

    This document contains specific advice and requirements for NASA Ames Code IN authors of NAS reports. Much of the information may be of interest to other authors writing for the Web. WebPrep has a graphic Table of Contents in the form of a WebToon, which simulates a discussion between a scientist and a Web publishing consultant. In the WebToon, Frequently Asked Questions about preparing reports for the Web are linked to relevant text in the body of this document. We also provide a text-only Table of Contents. The text for this document is divided into chapters: each chapter corresponds to one frame of the WebToons. The chapter topics are: converting text to HTML, converting 2D graphic images to gif, creating imagemaps and tables, converting movie and audio files to Web formats, supplying 3D interactive data, and (briefly) JAVA capabilities. The last chapter is specifically for NAS staff authors. The Glossary-Index lists web related words and links to topics covered in the main text.

  20. The Performance of the NAS HSPs in 1st Half of 1994

    NASA Technical Reports Server (NTRS)

    Bergeron, Robert J.; Walter, Howard (Technical Monitor)

    1995-01-01

    During the first six months of 1994, the NAS (National Airspace System) 16-CPU Y-MP C90 Von Neumann (VN) delivered an average throughput of 4.045 GFLOPS while the ACSF (Aeronautics Consolidated Supercomputer Facility) 8-CPU Y-MP C90 Eagle averaged 1.658 GFLOPS. The VN rate represents a machine efficiency of 26.3% whereas the Eagle rate corresponds to a machine efficiency of 21.6%. VN displayed a greater efficiency than Eagle primarily because the stronger workload demand for its CPU cycles allowed it to devote more time to user programs and less time to idle. An additional factor increasing VN efficiency was the ability of the UNICOS 8.0 Operating System to deliver a larger fraction of CPU time to user programs. Although measurements indicate increasing vector length for both workloads, insufficient vector lengths continue to hinder HSP (High Speed Processor) performance. To improve HSP performance, NAS should continue to encourage the HSP users to modify their codes to increase program vector length.

  1. 48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-conditioning system (Specified under 600 Sections) 5 Entire boiler plant system (Specified under 700 Sections... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Payments under fixed-price construction contracts (without NAS). 852.236-82 Section 852.236-82 Federal Acquisition Regulations System...

  2. 48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (cold, constant temperature) 5 Entire air-conditioning system (Specified under 600 Sections) 5 Entire... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Payments under fixed-price construction contracts (including NAS). 852.236-83 Section 852.236-83 Federal Acquisition Regulations System...

  3. NAS Decadal Review Town Hall

    NASA Astrophysics Data System (ADS)

    The National Academies of Sciences, Engineering and Medicine is seeking community input for a study on the future of materials research (MR). Frontiers of Materials Research: A Decadal Survey will look at defining the frontiers of materials research ranging from traditional materials science and engineering to condensed matter physics. Please join members of the study committee for a town hall to discuss future directions for materials research in the United States in the context of worldwide efforts. In particular, input on the following topics will be of great value: progress, achievements, and principal changes in the R&D landscape over the past decade; identification of key MR areas that have major scientific gaps or offer promising investment opportunities from 2020-2030; and the challenges that MR may face over the next decade and how those challenges might be addressed. This study was requested by the Department of Energy and the National Science Foundation. The National Academies will issue a report in 2018 that will offer guidance to federal agencies that support materials research, science policymakers, and researchers in materials research and other adjoining fields. Learn more about the study at http://nas.edu/materials.

  4. Pressure and PL study of dilute-N GaInNAs films for applications in photovoltaics

    NASA Astrophysics Data System (ADS)

    Lindberg, George; Fukuda, Miwa; Al Khalfioui, M.; Hossain, Khalid; Sellers, Ian; Weinstein, Bernard

    2013-03-01

    Multi-junction photovoltaic devices employing dilute-N GaInNAs alloys are currently of high interest for efficient solar energy conversion. The negative band-bowing produced by introducing a few percent N into GaInAs provides a convenient way to match the 1eV component of the solar spectrum, providing recombination losses in localized states can be reduced while maintaining favorable carrier extraction. High pressure photoluminescence (PL) experiments exploring the localization of band-edge excitons in dilute-N GaInNAs films grown by plasma assisted MBE will be discussed. The effects of post-growth annealing and hydrogen incorporation on the PL spectra of the films are considered. Research supported by Amethyst Research Inc. through the State of Oklahoma, ONAP program.

  5. Room-temperature electron spin amplifier based on Ga(In)NAs alloys.

    PubMed

    Puttisong, Yuttapoom; Buyanova, Irina A; Ptak, Aaron J; Tu, Charles W; Geelhaar, Lutz; Riechert, Henning; Chen, Weimin M

    2013-02-06

    The first experimental demonstration of a spin amplifier at room temperature is presented. An efficient, defect-enabled spin amplifier based on a non-magnetic semiconductor, Ga(In)NAs, is proposed and demonstrated, with a large spin gain (up to 2700% at zero field) for conduction electrons and a high cut-off frequency of up to 1 GHz. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Stem gravitropism and tension wood formation in Acacia mangium seedlings inclined at various angles.

    PubMed

    Nugroho, Widyanto Dwi; Nakaba, Satoshi; Yamagishi, Yusuke; Begum, Shahanara; Rahman, Md Hasnat; Kudo, Kayo; Marsoem, Sri Nugroho; Funada, Ryo

    2018-05-03

    In response to a gravitational stimulus, angiosperm trees generally form tension wood on the upper sides of leaning stems in order to reorientate the stems in the vertical direction. It is unclear whether the angle of inclination from the vertical affects tension wood formation. This study was designed to investigate negative gravitropism, tension wood formation and growth eccentricity in Acacia mangium seedlings inclined at different angles. Uniform seedlings of A. mangium were artificially inclined at 30°, 45°, 60° and 90° from the vertical and harvested, with non-inclined controls, 3 months later. We analysed the effects of the angle of inclination on the stem recovery angle, the anatomical features of tension wood and radial growth. Smaller inclination angles were associated with earlier stem recovery while stems subjected to greater inclination returned to the vertical direction after a longer delay. However, in terms of the speed of negative gravitopism towards the vertical, stems subjected to greater inclination moved more rapidly toward the vertical. There was no significant difference in terms of growth eccentricity among seedlings inclined at different angles. The 30°-inclined seedlings formed the narrowest region of tension wood but there were no significant differences among seedlings inclined at 45°, 60° and 90°. The 90°-inclined seedlings formed thicker gelatinous layers than those in 30°-, 45°- and 60°-inclined seedlings. Our results suggest that the angle of inclination of the stem influences negative gravitropism, the width of the tension wood region and the thickness of gelatinous layers. Larger amounts of gelatinous fibres and thicker gelatinous layers might generate the higher tensile stress required for the higher speed of stem-recovery movement in A. mangium seedlings.

  7. 48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

  8. 48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

  9. 48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

  10. 48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

  11. Analysis of genetic population structure in Acacia caven (Leguminosae, Mimosoideae), comparing one exploratory and two Bayesian-model-based methods

    PubMed Central

    Pometti, Carolina L.; Bessega, Cecilia F.; Saidman, Beatriz O.; Vilardi, Juan C.

    2014-01-01

    Bayesian clustering as implemented in STRUCTURE or GENELAND software is widely used to form genetic groups of populations or individuals. On the other hand, in order to satisfy the need for less computer-intensive approaches, multivariate analyses are specifically devoted to extracting information from large datasets. In this paper, we report the use of a dataset of AFLP markers belonging to 15 sampling sites of Acacia caven for studying the genetic structure and comparing the consistency of three methods: STRUCTURE, GENELAND and DAPC. Of these methods, DAPC was the fastest one and showed accuracy in inferring the K number of populations (K = 12 using the find.clusters option and K = 15 with a priori information of populations). GENELAND in turn, provides information on the area of membership probabilities for individuals or populations in the space, when coordinates are specified (K = 12). STRUCTURE also inferred the number of K populations and the membership probabilities of individuals based on ancestry, presenting the result K = 11 without prior information of populations and K = 15 using the LOCPRIOR option. Finally, in this work all three methods showed high consistency in estimating the population structure, inferring similar numbers of populations and the membership probabilities of individuals to each group, with a high correlation between each other. PMID:24688293

  12. Analysis of genetic population structure in Acacia caven (Leguminosae, Mimosoideae), comparing one exploratory and two Bayesian-model-based methods.

    PubMed

    Pometti, Carolina L; Bessega, Cecilia F; Saidman, Beatriz O; Vilardi, Juan C

    2014-03-01

    Bayesian clustering as implemented in STRUCTURE or GENELAND software is widely used to form genetic groups of populations or individuals. On the other hand, in order to satisfy the need for less computer-intensive approaches, multivariate analyses are specifically devoted to extracting information from large datasets. In this paper, we report the use of a dataset of AFLP markers belonging to 15 sampling sites of Acacia caven for studying the genetic structure and comparing the consistency of three methods: STRUCTURE, GENELAND and DAPC. Of these methods, DAPC was the fastest one and showed accuracy in inferring the K number of populations (K = 12 using the find.clusters option and K = 15 with a priori information of populations). GENELAND in turn, provides information on the area of membership probabilities for individuals or populations in the space, when coordinates are specified (K = 12). STRUCTURE also inferred the number of K populations and the membership probabilities of individuals based on ancestry, presenting the result K = 11 without prior information of populations and K = 15 using the LOCPRIOR option. Finally, in this work all three methods showed high consistency in estimating the population structure, inferring similar numbers of populations and the membership probabilities of individuals to each group, with a high correlation between each other.

  13. Longevity and growth of Acacia tortilis; insights from 14C content and anatomy of wood

    PubMed Central

    Andersen, Gidske L; Krzywinski, Knut

    2007-01-01

    Background Acacia tortilis is a keystone species across arid ecosystems in Africa and the Middle East. Yet, its life-history, longevity and growth are poorly known, and consequently ongoing changes in tree populations cannot be managed in an appropriate manner. In other arid areas parenchymatic bands marking growth zones in the wood have made dendrochronological studies possible. The possibilities for using pre- and post-bomb 14C content in wood samples along with the presence of narrow marginal parenchymatic bands in the wood is therefore tested to gain further insight into the age, growth and growth conditions of A. tortilis in the hyper-arid Eastern Desert of Egypt. Results Based on age scenarios and the Gompertz growth equation, the age of trees studied seems to be from 200 up to 650 years. Annual radial growth estimated from calibrated dates based on the post-bomb 14C content of samples is up to 2.4 mm, but varies both spatially and temporally. Parenchymatic bands are not formed regularly. The correlation in band pattern among trees is poor, both among and within sites. Conclusion The post-bomb 14C content of A. tortilis wood gives valuable information on tree growth and is required to assess the age scenario approach applied here. This approach indicates high longevities and slow growth of trees. Special management measures should therefore be taken at sites where the trend in tree population size is negative. The possibilities for dendrochronological studies based on A. tortilis from the Eastern Desert are poor. However, marginal parenchymatic bands can give insight into fine scale variation in growth conditions and the past management of trees. PMID:17573964

  14. 48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... shall show on the critical path method (CPM) network the total cost of the guarantee period services in... prescribed in 832.111, insert the following clause in contracts that contain a section entitled “Network...) Failure either to meet schedules in Section Network Analysis System (NAS), or to process the Interim Arrow...

  15. 48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... shall show on the critical path method (CPM) network the total cost of the guarantee period services in... prescribed in 832.111, insert the following clause in contracts that contain a section entitled “Network...) Failure either to meet schedules in Section Network Analysis System (NAS), or to process the Interim Arrow...

  16. 48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... shall show on the critical path method (CPM) network the total cost of the guarantee period services in... prescribed in 832.111, insert the following clause in contracts that contain a section entitled “Network...) Failure either to meet schedules in Section Network Analysis System (NAS), or to process the Interim Arrow...

  17. Remotely Operated Aircraft (ROA) Impact on the National Airspace System (NAS) Work Package: Automation Impacts of ROA's in the NAS

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The purpose of this document is to analyze the impact of Remotely Operated Aircraft (ROA) operations on current and planned Air Traffic Control (ATC) automation systems in the En Route, Terminal, and Traffic Flow Management domains. The operational aspects of ROA flight, while similar, are not entirely identical to their manned counterparts and may not have been considered within the time-horizons of the automation tools. This analysis was performed to determine if flight characteristics of ROAs would be compatible with current and future NAS automation tools. Improvements to existing systems / processes are recommended that would give Air Traffic Controllers an indication that a particular aircraft is an ROA and modifications to IFR flight plan processing algorithms and / or designation of airspace where an ROA will be operating for long periods of time.

  18. Silver nanoparticle (AgNPs) doped gum acacia-gelatin-silica nanohybrid: an effective support for diastase immobilization.

    PubMed

    Singh, Vandana; Ahmed, Shakeel

    2012-03-01

    An effective carrier matrix for diastase alpha amylase immobilization has been fabricated by gum acacia-gelatin dual templated polymerization of tetramethoxysilane. Silver nanoparticle (AgNp) doping to this hybrid could significantly enhance the shelf life of the impregnated enzyme while retaining its full bio-catalytic activity. The doped nanohybrid has been characterized as a thermally stable porous material which also showed multipeak photoluminescence under UV excitation. The immobilized diastase alpha amylase has been used to optimize the conditions for soluble starch hydrolysis in comparison to the free enzyme. The optimum pH for both immobilized and free enzyme hydrolysis was found to be same (pH=5), indicating that the immobilization made no major change in enzyme conformation. The immobilized enzyme showed good performance in wide temperature range (from 303 to 323 K), 323 K being the optimum value. The kinetic parameters for the immobilized, (K(m)=10.30 mg/mL, V(max)=4.36 μmol mL(-1)min(-1)) and free enzyme (K(m)=8.85 mg/mL, V(max)=2.81 μmol mL(-1)min(-1)) indicated that the immobilization improved the overall stability and catalytic property of the enzyme. The immobilized enzyme remained usable for repeated cycles and did not lose its activity even after 30 days storage at 40°C, while identically synthesized and stored silver undoped hybrid lost its ~31% activity in 48 h. Present study revealed the hybrids to be potentially useful for biomedical and optical applications. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Validation of the nursing workload scoring systems "Nursing Activities Score" (NAS), and "Therapeutic Intervention Scoring System For Critically Ill Children" (TISS-C) in a Greek Paediatric Intensive Care Unit.

    PubMed

    Nieri, Alexandra-Stavroula; Manousaki, Kalliopi; Kalafati, Maria; Padilha, Katia Grilio; Stafseth, Siv K; Katsoulas, Theodoros; Matziou, Vasiliki; Giannakopoulou, Margarita

    2018-04-11

    To assess the reliability and validity of the Greek version of Nursing Activities Score (NAS), and Therapeutic Intervention Scoring System for Critically Ill Children (TISS-C) in a Greek Paediatric Intensive Care Unit (PICU). A methodological study was performed in one PICU of the largest Paediatric Hospital in Athens-Greece. The culturally adapted and validated Greek NAS version, enriched according to the Norwegian paediatric one (P-NAS), was used. TISS-C and Norwegian paediatric interventions were translated to Greek language and backwards. Therapeutic Intervention Scoring System (TISS-28) was used as a gold standard. Two independent observers simultaneously recorded 30 daily P-NAS and TISS-C records. Totally, 188 daily P-NAS, TISS-C and TISS-28 reports in a sample of 29 patients have been obtained during 5 weeks. Descriptive statistics, reliability and validity measures were applied using SPSS (ver 22.0) (p ≤ 0.05). Kappa was 0.963 for P-NAS and 0.9895 for TISS-C (p < 0.001) and Intraclass Correlation Coefficient for all scale items of TISS-C was 1.00 (p < 0.001). P-NAS, TISS-28 and TISS-C measurements were significantly correlated (0.680 ≤ rho ≤ 0.743, p < 0.001). The mean score(±SD) for TISS-28, P-NAS and TISS-C was 23.05(±5.72), 58.14(±13.98) and 20.21(±9.66) respectively. These results support the validity of P-NAS and TISS-C scales to be used in Greek PICUs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Navigation in Grid Space with the NAS Grid Benchmarks

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael; Hood, Robert; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    We present a navigational tool for computational grids. The navigational process is based on measuring the grid characteristics with the NAS Grid Benchmarks (NGB) and using the measurements to assign tasks of a grid application to the grid machines. The tool allows the user to explore the grid space and to navigate the execution at a grid application to minimize its turnaround time. We introduce the notion of gridscape as a user view of the grid and show how it can be me assured by NGB, Then we demonstrate how the gridscape can be used with two different schedulers to navigate a grid application through a rudimentary grid.

  1. Induction of Osmoregulation and Modulation of Salt Stress in Acacia gerrardii Benth. by Arbuscular Mycorrhizal Fungi and Bacillus subtilis (BERA 71)

    PubMed Central

    Hashem, Abeer; Alqarawi, A. A.; Al-Huqail, A. A.; Shah, M. A.

    2016-01-01

    The role of soil microbiota in plant stress management, though speculated a lot, is still far from being completely understood. We conducted a greenhouse experiment to examine synergistic impact of plant growth promoting rhizobacterium, Bacillus subtilis (BERA 71), and arbuscular mycorrhizal fungi (AMF) (Claroideoglomus etunicatum; Rhizophagus intraradices; and Funneliformis mosseae) to induce acquired systemic resistance in Talh tree (Acacia gerrardii Benth.) against adverse impact of salt stress. Compared to the control, the BERA 71 treatment significantly enhanced root colonization intensity by AMF, in both presence and absence of salt. We also found positive synergistic interaction between B. subtilis and AMF vis-a-vis improvement in the nutritional value in terms of increase in total lipids, phenols, and fiber content. The AMF and BERA 71 inoculated plants showed increased content of osmoprotectants such as glycine, betaine, and proline, though lipid peroxidation was reduced probably as a mechanism of salt tolerance. Furthermore, the application of bioinoculants to Talh tree turned out to be potentially beneficial in ameliorating the deleterious impact of salinity on plant metabolism, probably by modulating the osmoregulatory system (glycine betaine, proline, and phenols) and antioxidant enzymes system (SOD, CAT, POD, GR, APX, DHAR, MDAHR, and GSNOR). PMID:27597969

  2. NASA's UAS Integration into the NAS: A Report on the Human Systems Integration Phase 1 Simulation Activities

    NASA Technical Reports Server (NTRS)

    Fern, Lisa; Rorie, R. Conrad; Shively, R. Jay

    2014-01-01

    In 2011 the National Aeronautics and Space Administration (NASA) began a five-year Project to address the technical barriers related to routine access of Unmanned Aerial Systems (UAS) in the National Airspace System (NAS). Planned in two phases, the goal of the first phase was to lay the foundations for the Project by identifying those barriers and key issues to be addressed to achieve integration. Phase 1 activities were completed two years into the five-year Project. The purpose of this paper is to review activities within the Human Systems Integration (HSI) subproject in Phase 1 toward its two objectives: 1) develop GCS guidelines for routine UAS access to the NAS, and 2) develop a prototype display suite within an existing Ground Control Station (GCS). The first objective directly addresses a critical barrier for UAS integration into the NAS - a lack of GCS design standards or requirements. First, the paper describes the initial development of a prototype GCS display suite and supporting simulation software capabilities. Then, three simulation experiments utilizing this simulation architecture are summarized. The first experiment sought to determine a baseline performance of UAS pilots operating in civil airspace under current instrument flight rules for manned aircraft. The second experiment examined the effect of currently employed UAS contingency procedures on Air Traffic Control (ATC) participants. The third experiment compared three GCS command and control interfaces on UAS pilot response times in compliance with ATC clearances. The authors discuss how the results of these and future simulation and flight-testing activities contribute to the development of GCS guidelines to support the safe integration of UAS into the NAS. Finally, the planned activities for Phase 2, including an integrated human-in-the-loop simulation and two flight tests are briefly described.

  3. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project

    NASA Technical Reports Server (NTRS)

    Griner, James H.

    2013-01-01

    NASA's UAS Integration in the NAS project, has partnered with Rockwell Collins to develop a concept Control and Non-Payload Communication system prototype radio, operating on recently allocated UAS frequency spectrum bands. The prototype radio will be used to validate initial proposed performance requirements for UAS control communications. This presentation will give an overview of the current status of the design, development, and flight test planning for this prototype radio.

  4. Enhancement of photoluminescence from GaInNAsSb quantum wells upon annealing: improvement of material quality and carrier collection by the quantum well.

    PubMed

    Baranowski, M; Kudrawiec, R; Latkowska, M; Syperek, M; Misiewicz, J; Sarmiento, T; Harris, J S

    2013-02-13

    In this study we apply time resolved photoluminescence and contactless electroreflectance to study the carrier collection efficiency of a GaInNAsSb/GaAs quantum well (QW). We show that the enhancement of photoluminescence from GaInNAsSb quantum wells annealed at different temperatures originates not only from (i) the improvement of the optical quality of the GaInNAsSb material (i.e., removal of point defects, which are the source of nonradiative recombination) but it is also affected by (ii) the improvement of carrier collection by the QW region. The total PL efficiency is the product of these two factors, for which the optimal annealing temperatures are found to be ~700 °C and ~760 °C, respectively, whereas the optimal annealing temperature for the integrated PL intensity is found to be between the two temperatures and equals ~720 °C. We connect the variation of the carrier collection efficiency with the modification of the band bending conditions in the investigated structure due to the Fermi level shift in the GaInNAsSb layer after annealing.

  5. Assessing nitrogen fixation in mixed- and single-species plantations of Eucalyptus globulus and Acacia mearnsii.

    PubMed

    Forrester, David I; Schortemeyer, Marcus; Stock, William D; Bauhus, Jürgen; Khanna, Partap K; Cowie, Annette L

    2007-09-01

    Mixtures of Eucalyptus globulus Labill. and Acacia mearnsii de Wildeman are twice as productive as E. globulus monocultures growing on the same site in East Gippsland, Victoria, Australia, possibly because of increased nitrogen (N) availability owing to N(2) fixation by A. mearnsii. To investigate whether N(2) fixation by A. mearnsii could account for the mixed-species growth responses, we assessed N(2) fixation by the accretion method and the (15)N natural abundance method. Nitrogen gained by E. globulus and A. mearnsii mixtures and monocultures was calculated by the accretion method with plant and soil samples collected 10 years after plantation establishment. Nitrogen in biomass and soil confirmed that A. mearnsii influenced N dynamics. Assuming that the differences in soil, forest floor litter and biomass N of plots containing A. mearnsii compared with E. globulus monocultures were due to N(2) fixation, the 10-year annual mean rates of N(2) fixation were 38 and 86 kg ha(-1) year(-1) in 1:1 mixtures and A. mearnsii monocultures, respectively. Nitrogen fixation by A. mearnsii could not be quantified on the basis of the natural abundance of (15)N because such factors as mycorrhization type and fractionation of N isotopes during N cycling within the plant confounded the effect of the N source on the N isotopic signature of plants. This study shows that A. mearnsii fixed significant quantities of N(2) when mixed with E. globulus. A decline in delta(15)N values of E. globulus and A. mearnsii with time, from 2 to 10 years, is further evidence that N(2) was fixed and cycled through the stands. The increased aboveground biomass production of E. globulus trees in mixtures when compared with monocultures can be attributed to increases in N availability.

  6. Ultramicroporous Carbon through an Activation-Free Approach for Li-S and Na-S Batteries in Carbonate-Based Electrolyte.

    PubMed

    Hu, Lei; Lu, Yue; Zhang, Tianwen; Huang, Tao; Zhu, Yongchun; Qian, Yitai

    2017-04-26

    We report an activation-free approach for fabricating ultramicroporous carbon as an accommodation of sulfur molecules for Li-S and Na-S batteries applications in carbonate-based electrolyte. Because of the high specific surface area of 967 m 2 g -1 , as well as 51.8% of the pore volume is contributed by ultramicropore with pore size less than 0.7 nm, sulfur cathode exhibits superior electrochemical behavior in carbonate-based electrolyte with a capacity of 507.9 mA h g -1 after 500 cycles at 2 C in Li-S batteries and 392 mA h g -1 after 200 cycles at 1 C in Na-S batteries, respectively.

  7. ARCAS (ACACIA Regional Climate-data Access System) -- a Web Access System for Climate Model Data Access, Visualization and Comparison

    NASA Astrophysics Data System (ADS)

    Hakkarinen, C.; Brown, D.; Callahan, J.; hankin, S.; de Koningh, M.; Middleton-Link, D.; Wigley, T.

    2001-05-01

    A Web-based access system to climate model output data sets for intercomparison and analysis has been produced, using the NOAA-PMEL developed Live Access Server software as host server and Ferret as the data serving and visualization engine. Called ARCAS ("ACACIA Regional Climate-data Access System"), and publicly accessible at http://dataserver.ucar.edu/arcas, the site currently serves climate model outputs from runs of the NCAR Climate System Model for the 21st century, for Business as Usual and Stabilization of Greenhouse Gas Emission scenarios. Users can select, download, and graphically display single variables or comparisons of two variables from either or both of the CSM model runs, averaged for monthly, seasonal, or annual time resolutions. The time length of the averaging period, and the geographical domain for download and display, are fully selectable by the user. A variety of arithmetic operations on the data variables can be computed "on-the-fly", as defined by the user. Expansions of the user-selectable options for defining analysis options, and for accessing other DOD-compatible ("Distributed Ocean Data System-compatible") data sets, residing at locations other than the NCAR hardware server on which ARCAS operates, are planned for this year. These expansions are designed to allow users quick and easy-to-operate web-based access to the largest possible selection of climate model output data sets available throughout the world.

  8. Differing Courses of Genetic Evolution of Bradyrhizobium Inoculants as Revealed by Long-Term Molecular Tracing in Acacia mangium Plantations

    PubMed Central

    Perrineau, M. M.; Le Roux, C.; Galiana, A.; Faye, A.; Duponnois, R.; Goh, D.; Prin, Y.

    2014-01-01

    Introducing nitrogen-fixing bacteria as an inoculum in association with legume crops is a common practice in agriculture. However, the question of the evolution of these introduced microorganisms remains crucial, both in terms of microbial ecology and agronomy. We explored this question by analyzing the genetic and symbiotic evolution of two Bradyrhizobium strains inoculated on Acacia mangium in Malaysia and Senegal 15 and 5 years, respectively, after their introduction. Based on typing of several loci, we showed that these two strains, although closely related and originally sampled in Australia, evolved differently. One strain was recovered in soil with the same five loci as the original isolate, whereas the symbiotic cluster of the other strain was detected with no trace of the three housekeeping genes of the original inoculum. Moreover, the nitrogen fixation efficiency was variable among these isolates (either recombinant or not), with significantly high, low, or similar efficiencies compared to the two original strains and no significant difference between recombinant and nonrecombinant isolates. These data suggested that 15 years after their introduction, nitrogen-fixing bacteria remain in the soil but that closely related inoculant strains may not evolve in the same way, either genetically or symbiotically. In a context of increasing agronomical use of microbial inoculants (for biological control, nitrogen fixation, or plant growth promotion), this result feeds the debate on the consequences associated with such practices. PMID:25002434

  9. The OpenMP Implementation of NAS Parallel Benchmarks and its Performance

    NASA Technical Reports Server (NTRS)

    Jin, Hao-Qiang; Frumkin, Michael; Yan, Jerry

    1999-01-01

    As the new ccNUMA architecture became popular in recent years, parallel programming with compiler directives on these machines has evolved to accommodate new needs. In this study, we examine the effectiveness of OpenMP directives for parallelizing the NAS Parallel Benchmarks. Implementation details will be discussed and performance will be compared with the MPI implementation. We have demonstrated that OpenMP can achieve very good results for parallelization on a shared memory system, but effective use of memory and cache is very important.

  10. Spatial genetic structure within populations and management implications of the South American species Acacia aroma (Fabaceae).

    PubMed

    Pometti, Carolina; Bessega, Cecilia; Cialdella, Ana; Ewens, Mauricio; Saidman, Beatriz; Vilardi, Juan

    2018-01-01

    The identification of factors that structure intraspecific diversity is of particular interest for biological conservation and restoration ecology. All rangelands in Argentina are currently experiencing some form of deterioration or desertification. Acacia aroma is a multipurpose species widely distributed throughout this country. In this study, we used the AFLP technique to study genetic diversity, population genetic structure, and fine-scale spatial genetic structure in 170 individuals belonging to 6 natural Argentinean populations. With 401 loci, the mean heterozygosity (HE = 0.2) and the mean percentage of polymorphic loci (PPL = 62.1%) coefficients indicated that the genetic variation is relatively high in A. aroma. The analysis with STRUCTURE showed that the number of clusters (K) was 3. With Geneland analysis, the number of clusters was K = 4, sharing the same grouping as STRUCTURE but dividing one population into two groups. When studying SGS, significant structure was detected in 3 of 6 populations. The neighbourhood size in these populations ranged from 15.2 to 64.3 individuals. The estimated gene dispersal distance depended on the effective population density and disturbance level and ranged from 45 to 864 m. The combined results suggest that a sampling strategy, which aims to maintain a considerable part of the variability contained in natural populations sampled here, would include at least 3 units defined by the clusters analyses that exhibit particular genetic properties. Moreover, the current SGS analysis suggests that within the wider management units/provinces, seed collection from A. aroma should target trees separated by a minimum distance of 50 m but preferably 150 m to reduce genetic relatedness among seeds from different trees.

  11. Spatial genetic structure within populations and management implications of the South American species Acacia aroma (Fabaceae)

    PubMed Central

    Bessega, Cecilia; Cialdella, Ana; Ewens, Mauricio; Saidman, Beatriz; Vilardi, Juan

    2018-01-01

    The identification of factors that structure intraspecific diversity is of particular interest for biological conservation and restoration ecology. All rangelands in Argentina are currently experiencing some form of deterioration or desertification. Acacia aroma is a multipurpose species widely distributed throughout this country. In this study, we used the AFLP technique to study genetic diversity, population genetic structure, and fine-scale spatial genetic structure in 170 individuals belonging to 6 natural Argentinean populations. With 401 loci, the mean heterozygosity (HE = 0.2) and the mean percentage of polymorphic loci (PPL = 62.1%) coefficients indicated that the genetic variation is relatively high in A. aroma. The analysis with STRUCTURE showed that the number of clusters (K) was 3. With Geneland analysis, the number of clusters was K = 4, sharing the same grouping as STRUCTURE but dividing one population into two groups. When studying SGS, significant structure was detected in 3 of 6 populations. The neighbourhood size in these populations ranged from 15.2 to 64.3 individuals. The estimated gene dispersal distance depended on the effective population density and disturbance level and ranged from 45 to 864 m. The combined results suggest that a sampling strategy, which aims to maintain a considerable part of the variability contained in natural populations sampled here, would include at least 3 units defined by the clusters analyses that exhibit particular genetic properties. Moreover, the current SGS analysis suggests that within the wider management units/provinces, seed collection from A. aroma should target trees separated by a minimum distance of 50 m but preferably 150 m to reduce genetic relatedness among seeds from different trees. PMID:29389969

  12. A medicinal extract of Scutellaria baicalensis and Acacia catechu acts as a dual inhibitor of cyclooxygenase and 5-lipoxygenase to reduce inflammation.

    PubMed

    Burnett, B P; Jia, Q; Zhao, Y; Levy, R M

    2007-09-01

    A mixed extract containing two naturally occurring flavonoids, baicalin from Scutellaria baicalensis and catechin from Acacia catechu, was tested for cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) inhibition via enzyme, cellular, and in vivo models. The 50% inhibitory concentration for inhibition of both ovine COX-1 and COX-2 peroxidase enzyme activities was 15 microg/mL, while the mixed extract showed a value for potato 5-LOX enzyme activity of 25 microg/mL. Prostaglandin E2 generation was inhibited by the mixed extract in human osteosarcoma cells expressing COX-2, while leukotriene production was inhibited in both human cell lines, immortalized THP-1 monocyte and HT-29 colorectal adenocarcinoma. In an arachidonic acid-induced mouse ear swelling model, the extract decreased edema in a dose-dependent manner. When arachidonic acid was injected directly into the intra-articular space of mouse ankle joints, the mixed extract abated the swelling and restored function in a rotary drum walking model. These results suggest that this natural, flavonoid mixture acts via "dual inhibition" of COX and LOX enzymes to reduce production of pro-inflammatory eicosanoids and attenuate edema in an in vivo model of inflammation.

  13. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project: KDP-A for Phase 2 Minimum Operational Performance Standards

    NASA Technical Reports Server (NTRS)

    Grindle, Laurie; Hackenberg, Davis L.

    2016-01-01

    UAS Integration in the NAS Project has: a) Developed Technical Challenges that are crucial to UAS integration, aligned with NASA's Strategic Plan and Thrusts, and support FAA standards development. b) Demonstrated rigorous project management processes through the execution of previous phases. c) Defined Partnership Plans. d) Established path to KDP-C. Request approval of Technical Challenges, execution of partnerships and plans, and execution of near-term FY17 activities. There is an increasing need to fly UAS in the NAS to perform missions of vital importance to National Security and Defense, Emergency Management, and Science. There is also an emerging need to enable commercial applications such as cargo transport (e.g. FedEx). Unencumbered NAS Access for Civil/Commercial UAS. Provide research findings, utilizing simulation and flight tests, to support the development and validation of DAA and C2 technologies necessary for integrating Unmanned Aircraft Systems into the National Airspace System.

  14. Applying landscape genomic tools to forest management and restoration of Hawaiian koa (Acacia koa) in a changing environment.

    PubMed

    Gugger, Paul F; Liang, Christina T; Sork, Victoria L; Hodgskiss, Paul; Wright, Jessica W

    2018-02-01

    Identifying and quantifying the importance of environmental variables in structuring population genetic variation can help inform management decisions for conservation, restoration, or reforestation purposes, in both current and future environmental conditions. Landscape genomics offers a powerful approach for understanding the environmental factors that currently associate with genetic variation, and given those associations, where populations may be most vulnerable under future environmental change. Here, we applied genotyping by sequencing to generate over 11,000 single nucleotide polymorphisms from 311 trees and then used nonlinear, multivariate environmental association methods to examine spatial genetic structure and its association with environmental variation in an ecologically and economically important tree species endemic to Hawaii, Acacia koa . Admixture and principal components analyses showed that trees from different islands are genetically distinct in general, with the exception of some genotypes that match other islands, likely as the result of recent translocations. Gradient forest and generalized dissimilarity models both revealed a strong association between genetic structure and mean annual rainfall. Utilizing a model for projected future climate on the island of Hawaii, we show that predicted changes in rainfall patterns may result in genetic offset, such that trees no longer may be genetically matched to their environment. These findings indicate that knowledge of current and future rainfall gradients can provide valuable information for the conservation of existing populations and also help refine seed transfer guidelines for reforestation or replanting of koa throughout the state.

  15. In vitro antioxidant and antimalarial activities of leaves, pods and bark extracts of Acacia nilotica (L.) Del.

    PubMed

    Sadiq, Muhammad Bilal; Tharaphan, Pattamon; Chotivanich, Kesinee; Tarning, Joel; Anal, Anil Kumar

    2017-07-18

    The emergence of drug resistant malaria is threatening our ability to treat and control malaria in the Southeast Asian region. There is an urgent need to develop novel and chemically diverse antimalarial drugs. This study aimed at evaluating the antimalarial and antioxidant potentials of Acacia nilotica plant extracts. The antioxidant activities of leaves, pods and bark extracts were determined by standard antioxidant assays; reducing power capacity, % lipid peroxidation inhibition and ferric reducing antioxidant power assay. The antimalarial activities of plant extracts against Plasmodium falciparum parasites were determined by the 48 h schizont maturation inhibition assay. Further confirmation of schizonticide activity of extracts was made by extending the incubation period up to 96 h after removing the plant extract residues from parasites culture. Inhibition assays were analyzed by dose-response modelling. In all antioxidant assays, leaves of A. nilotica showed higher antioxidant activity than pods and bark. Antimalarial IC 50 values of leaves, pods and bark extracts were 1.29, 4.16 and 4.28 μg/ml respectively, in the 48 h maturation assay. The IC 50 values determined for leaves, pods and bark extracts were 3.72, 5.41 and 5.32 μg/ml respectively, after 96 h of incubation. All extracts inhibited the development of mature schizont, indicating schizonticide activity against P. falciparum. A. nilotica extracts showed promising antimalarial and antioxidant effects. However, further investigation is needed to isolate and identify the active components responsible for the antimalarial and antioxidant effects.

  16. Removal of fluoride by thermally activated carbon prepared from neem (Azadirachta indica) and kikar (Acacia arabica) leaves.

    PubMed

    Kumar, Sunil; Gupta, Asha; Yadav, J P

    2008-03-01

    The present investigation deals with fluoride removal from aqueous solution by thermally activated neem (Azadirachta indica) leaves carbon (ANC) and thermally activated kikar (Acacia arabica) leaves carbon (AKC) adsorbents. In this study neem leaves carbon and kikar leaves carbon prepared by heating the leaves at 400 degrees C in electric furnace was found to be useful for the removal of fluoride. The adsorbents of 0.3 mm and 1.0 mm sizes of neem and kikar leaves carbon was prepared by standard sieve. Batch experiments done to see the fluoride removal properties from synthetic solution of 5 ppm to study the influence of pH, adsorbent dose and contact time on adsorption efficiency The optimum pH was found to be 6 for both adsorbents. The optimum dose was found to be 0.5g/100 ml forANC (activated neem leaves carbon) and 0.7g/100 ml forAKC (activated kikar leaves carbon). The optimum time was found to be one hour for both the adsorbent. It was also found that adsorbent size of 0.3 mm was more efficient than the 1.0 mm size. The adsorption process obeyed Freundlich adsorption isotherm. The straight line of log (qe-q) vs time at ambient temperature indicated the validity of langergren equation consequently first order nature of the process involved in the present study. Results indicate that besides intraparticle diffusion there maybe other processes controlling the rate which may be operating simultaneously. All optimized conditions were applied for removal of fluoride from four natural water samples.

  17. NAS (Numerical Aerodynamic Simulation Program) technical summaries, March 1989 - February 1990

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Given here are selected scientific results from the Numerical Aerodynamic Simulation (NAS) Program's third year of operation. During this year, the scientific community was given access to a Cray-2 and a Cray Y-MP supercomputer. Topics covered include flow field analysis of fighter wing configurations, large-scale ocean modeling, the Space Shuttle flow field, advanced computational fluid dynamics (CFD) codes for rotary-wing airloads and performance prediction, turbulence modeling of separated flows, airloads and acoustics of rotorcraft, vortex-induced nonlinearities on submarines, and standing oblique detonation waves.

  18. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project

    NASA Technical Reports Server (NTRS)

    Fern, Lisa

    2017-01-01

    This presentation summarizes the simulation work conducted by the Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project. It focuses on the contribution of that research to the development of RTCA Special Committee 228's (SC-228) Minimum Operational Performance Standards (MOPS) for UAS. The research objectives and primary findings from four different human-in-the-loop simulations are discussed, along with the specific requirements these studies led to in the final MOPS document.

  19. [Inventive activity of the Department of Metabolism Regulation of the Palladin Institute of Biochemistry of NAS of Ukraine].

    PubMed

    Danilova, V M; Vynogradova, R P; Chernysh, I G; Petrenko, T M

    2016-01-01

    The article is devoted to the inventive activity of the Department of Metabolism Regulation of the Palladin Institute of Biochemistry of NAS of Ukraine in the context of the history of its inception, development and the research activities of its founder, academician of NAS of Ukraine M. F. Guly as well as his students and followers. It briefly tells about practical achievements of M. F. Guly which were as significant, immense and diverse as his scientific accomplishments. The paper analyses in detail the practical results of scientific research of his students and followers aimed to solve practical problems of medicine, food-processing, agriculture, and which are essentially a continuation of the ideas and projects of M. F. Guly.

  20. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project FY16 Annual Review

    NASA Technical Reports Server (NTRS)

    Grindle, Laurie; Hackenberg, Davis

    2016-01-01

    This presentation gives insight into the research activities and efforts being executed in order to integrate unmanned aircraft systems into the national airspace system. This briefing is to inform others of the UAS-NAS FY16 progress and future directions.

  1. Cu2+ inhibition of gel secretion in the xylem and its potential implications for water uptake of cut Acacia holosericea stems.

    PubMed

    Ratnayake, Kamani; Joyce, Daryl C; Webb, Richard I

    2013-08-01

    Maintaining a high rate of water uptake is crucial for maximum longevity of cut stems. Physiological gel/tylosis formation decreases water transport efficiency in the xylem. The primary mechanism of action for post-harvest Cu(2+) treatments in improving cut flower and foliage longevity has been elusive. The effect of Cu(2+) on wound-induced xylem vessel occlusion was investigated for Acacia holosericea A. Cunn. ex G. Don. Experiments were conducted using a Cu(2+) pulse (5 h, 2.2 mM) and a Cu(2+) vase solution (0.5 mM) vs a deionized water (DIW) control. Development of xylem blockage in the stem-end region 10 mm proximal to the wounded stem surface was examined over 21 days by light and transmission electron microscopy. Xylem vessels of stems stood into DIW were occluded with gels secreted into vessel lumens via pits from surrounding axial parenchyma cells. Gel secretion was initiated within 1-2 days post-wounding and gels were detected in the xylem from day 3. In contrast, Cu(2+) treatments disrupted the surrounding parenchyma cells, thereby inhibiting gel secretion and maintaining the vessel lumens devoid of occlusions. The Cu(2+) treatments significantly improved water uptake by the cut stems as compared to the control. © 2013 Scandinavian Plant Physiology Society.

  2. Amorphous MoS3 as the sulfur-equivalent cathode material for room-temperature Li-S and Na-S batteries.

    PubMed

    Ye, Hualin; Ma, Lu; Zhou, Yu; Wang, Lu; Han, Na; Zhao, Feipeng; Deng, Jun; Wu, Tianpin; Li, Yanguang; Lu, Jun

    2017-12-12

    Many problems associated with Li-S and Na-S batteries essentially root in the generation of their soluble polysulfide intermediates. While conventional wisdom mainly focuses on trapping polysulfides at the cathode using various functional materials, few strategies are available at present to fully resolve or circumvent this long-standing issue. In this study, we propose the concept of sulfur-equivalent cathode materials, and demonstrate the great potential of amorphous MoS 3 as such a material for room-temperature Li-S and Na-S batteries. In Li-S batteries, MoS 3 exhibits sulfur-like behavior with large reversible specific capacity, excellent cycle life, and the possibility to achieve high areal capacity. Most remarkably, it is also fully cyclable in the carbonate electrolyte under a relatively high temperature of 55 °C. MoS 3 can also be used as the cathode material of even more challenging Na-S batteries to enable decent capacity and good cycle life. Operando X-ray absorption spectroscopy (XAS) experiments are carried out to track the structural evolution of MoS 3 It largely preserves its chain-like structure during repetitive battery cycling without generating any free polysulfide intermediates.

  3. Identification of nitrogen- and host-related deep-level traps in n-type GaNAs and their evolution upon annealing

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

    Gelczuk, Ł., E-mail: lukasz.gelczuk@pwr.edu.pl; Kudrawiec, R., E-mail: robert.kudrawiec@pwr.edu.pl; Henini, M.

    2014-07-07

    Deep level traps in as-grown and annealed n-GaNAs layers (doped with Si) of various nitrogen concentrations (N=0.2%, 0.4%, 0.8%, and 1.2%) were investigated by deep level transient spectroscopy. In addition, optical properties of GaNAs layers were studied by photoluminescence and contactless electroreflectance. The identification of N- and host-related traps has been performed on the basis of band gap diagram [Kudrawiec, Appl. Phys. Lett. 101, 082109 (2012)], which assumes that the activation energy of electron traps of the same microscopic nature decreases with the rise of nitrogen concentration in accordance with the N-related shift of the conduction band towards trap levels.more » The application of this diagram has allowed to investigate the evolution of donor traps in GaNAs upon annealing. In general, it was observed that the concentration of N- and host-related traps decreases after annealing and PL improves very significantly. However, it was also observed that some traps are generated due to annealing. It explains why the annealing conditions have to be carefully optimized for this material system.« less

  4. Wood-boring beetles associated with Acacia xanthophloea in Nairobi and Machakos Counties, Kenya

    PubMed Central

    Kirubi Thungu, Duncan; Wangu, Lucy; Kimani, Rachael

    2018-01-01

    Naivasha thorn tree, Acacia xanthophloea, is grown for foliage, timber, shade and rehabilitation of soils in areas with high water tables in Kenya. Its production is threatened by insect pests, which cause major losses. Very little is documented on wood-boring beetles which cause considerable economic damage to lumber used in a variety of applications, and little is known about their natural enemies in Kenya. We conducted the study to evaluate the occurrence of wood-boring beetles on A. xanthophloea in two different regions of Kenya. Infested wood samples of A. xanthophloea with fresh exit holes were collected from three sites in Kenyatta University (KU), Nairobi and Mitaboni in Machakos, Kenya. The samples were placed in clear plastic buckets and kept at ambient temperatures 23±2°C, 65±10% relative humidity and 12L: 12D in a laboratory where they were observed daily for adult emergence. Adult beetles were collected every three days for identification and data recording. The experiment was replicated four times and data collected twice a week for 6 months. Data on abundance was subjected to analysis of variance using SAS software. A total of 5,850 and 4,691 beetles were collected where 2,187 and 3,097 were Bostrichidae, accounting for 37% and 66% in KU and Mitaboni, respectively. A total of 12 bostrichid species was identified, including Sinoxylon ruficorne, S. doliolum, Xylion adustus, Xyloperthodes nitidipennis, Xyloperthella picea, Xylopsocus castanoptera, Lyctus brunneus, Heterbostrychus brunneus, Xylopsocus sp., and Dinoderus gabonicus. The most abundant species in KU was Xylion adustus with 1,915 beetles accounting for 88.4%, and Sinoxylon ruficorne in Mitaboni with 1,050 beetles accounting for 33.9% of the total. Sinoxylon ruficorne was only recorded in Mitaboni while only 2 specimens of D. gabonicus were found in KU. The mean number of exit holes on A. xanthophloea differed significantly between sites, which corresponded approximately to the amount of

  5. Wood-boring beetles associated with Acacia xanthophloea in Nairobi and Machakos Counties, Kenya.

    PubMed

    Kahuthia-Gathu, Ruth; Kirubi Thungu, Duncan; Wangu, Lucy; Kimani, Rachael

    2018-01-01

    Naivasha thorn tree, Acacia xanthophloea, is grown for foliage, timber, shade and rehabilitation of soils in areas with high water tables in Kenya. Its production is threatened by insect pests, which cause major losses. Very little is documented on wood-boring beetles which cause considerable economic damage to lumber used in a variety of applications, and little is known about their natural enemies in Kenya. We conducted the study to evaluate the occurrence of wood-boring beetles on A. xanthophloea in two different regions of Kenya. Infested wood samples of A. xanthophloea with fresh exit holes were collected from three sites in Kenyatta University (KU), Nairobi and Mitaboni in Machakos, Kenya. The samples were placed in clear plastic buckets and kept at ambient temperatures 23±2°C, 65±10% relative humidity and 12L: 12D in a laboratory where they were observed daily for adult emergence. Adult beetles were collected every three days for identification and data recording. The experiment was replicated four times and data collected twice a week for 6 months. Data on abundance was subjected to analysis of variance using SAS software. A total of 5,850 and 4,691 beetles were collected where 2,187 and 3,097 were Bostrichidae, accounting for 37% and 66% in KU and Mitaboni, respectively. A total of 12 bostrichid species was identified, including Sinoxylon ruficorne, S. doliolum, Xylion adustus, Xyloperthodes nitidipennis, Xyloperthella picea, Xylopsocus castanoptera, Lyctus brunneus, Heterbostrychus brunneus, Xylopsocus sp., and Dinoderus gabonicus. The most abundant species in KU was Xylion adustus with 1,915 beetles accounting for 88.4%, and Sinoxylon ruficorne in Mitaboni with 1,050 beetles accounting for 33.9% of the total. Sinoxylon ruficorne was only recorded in Mitaboni while only 2 specimens of D. gabonicus were found in KU. The mean number of exit holes on A. xanthophloea differed significantly between sites, which corresponded approximately to the amount of

  6. Effects of growth rate on structural property and adatom migration behaviors for growth of GaInNAs/GaAs (001) by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Li, Jingling; Gao, Peng; Zhang, Shuguang; Wen, Lei; Gao, Fangliang; Li, Guoqiang

    2018-03-01

    We have investigated the structural properties and the growth mode of GaInNAs films prepared at different growth rates (Rg) by molecular beam epitaxy. The crystalline structure is studied by high resolution X-ray diffraction, and the evolution of GaInNAs film surface morphologies is studied by atomic force microscopy. It is found that both the crystallinity and the surface roughness are improved by increasing Rg, and the change in the growth mode is attributed to the adatom migration behaviors particularly for In atoms, which is verified by elemental analysis. In addition, we have presented some theoretical calculation results related to the N adsorption energy to show the unique N migration behavior, which is instructive to interpret the growth mechanism of GaInNAs films.

  7. Gibberellin is required for the formation of tension wood and stem gravitropism in Acacia mangium seedlings

    PubMed Central

    Nugroho, Widyanto Dwi; Yamagishi, Yusuke; Nakaba, Satoshi; Fukuhara, Shiori; Begum, Shahanara; Marsoem, Sri Nugroho; Ko, Jae-Heung; Jin, Hyun-O; Funada, Ryo

    2012-01-01

    Background and Aims Angiosperm trees generally form tension wood on the upper sides of leaning stems. The formation of tension wood is an important response to gravitational stimulus. Gibberellin appears to be involved in the differentiation of secondary xylem, but it remains unclear whether gibberellin plays a key role in the formation of tension wood and plant gravitropism. Therefore, a study was designed to investigate the effects of gibberellin and of inhibitors of the synthesis of gibberellin, namely paclobutrazole and uniconazole-P, on the formation of tension wood and negative stem gravitropism in Acacia mangium seedlings. Methods Gibberellic acid (GA3), paclobutrazole and uniconazole-P were applied to seedlings via the soil in which they were growing. Distilled water was applied similarly as a control. Three days after such treatment, seedlings were tilted at an angle of 45° from the vertical, and samples of stems were collected for analysis 2 weeks, 2 months and 6 months after tilting. The effects of treatments on the stem recovery degree (Rº) were analysed as an index of the negative gravitropism of seedlings, together the width of the region of tension wood in the upper part of inclined stems. Key Results It was found that GA3 stimulated the negative gravitropism of tilted seedling stems of A. mangium, while paclobutrazole and uniconazole-P inhibited recovery to vertical growth. Moreover, GA3 stimulated the formation of tension wood in tilted A. mangium seedlings, while paclobutrazole and uniconazole-P strongly suppressed the formation of tension wood, as assessed 2 weeks after tilting. Conclusions The results suggest that gibberellin plays an important role at the initial stages of formation of tension wood and in stem gravitropism in A. mangium seedlings in response to a gravitational stimulus. PMID:22843341

  8. Gibberellin is required for the formation of tension wood and stem gravitropism in Acacia mangium seedlings.

    PubMed

    Nugroho, Widyanto Dwi; Yamagishi, Yusuke; Nakaba, Satoshi; Fukuhara, Shiori; Begum, Shahanara; Marsoem, Sri Nugroho; Ko, Jae-Heung; Jin, Hyun-O; Funada, Ryo

    2012-09-01

    Angiosperm trees generally form tension wood on the upper sides of leaning stems. The formation of tension wood is an important response to gravitational stimulus. Gibberellin appears to be involved in the differentiation of secondary xylem, but it remains unclear whether gibberellin plays a key role in the formation of tension wood and plant gravitropism. Therefore, a study was designed to investigate the effects of gibberellin and of inhibitors of the synthesis of gibberellin, namely paclobutrazole and uniconazole-P, on the formation of tension wood and negative stem gravitropism in Acacia mangium seedlings. Gibberellic acid (GA(3)), paclobutrazole and uniconazole-P were applied to seedlings via the soil in which they were growing. Distilled water was applied similarly as a control. Three days after such treatment, seedlings were tilted at an angle of 45° from the vertical, and samples of stems were collected for analysis 2 weeks, 2 months and 6 months after tilting. The effects of treatments on the stem recovery degree (Rº) were analysed as an index of the negative gravitropism of seedlings, together the width of the region of tension wood in the upper part of inclined stems. It was found that GA(3) stimulated the negative gravitropism of tilted seedling stems of A. mangium, while paclobutrazole and uniconazole-P inhibited recovery to vertical growth. Moreover, GA(3) stimulated the formation of tension wood in tilted A. mangium seedlings, while paclobutrazole and uniconazole-P strongly suppressed the formation of tension wood, as assessed 2 weeks after tilting. The results suggest that gibberellin plays an important role at the initial stages of formation of tension wood and in stem gravitropism in A. mangium seedlings in response to a gravitational stimulus.

  9. Differing courses of genetic evolution of Bradyrhizobium inoculants as revealed by long-term molecular tracing in Acacia mangium plantations.

    PubMed

    Perrineau, M M; Le Roux, C; Galiana, A; Faye, A; Duponnois, R; Goh, D; Prin, Y; Béna, G

    2014-09-01

    Introducing nitrogen-fixing bacteria as an inoculum in association with legume crops is a common practice in agriculture. However, the question of the evolution of these introduced microorganisms remains crucial, both in terms of microbial ecology and agronomy. We explored this question by analyzing the genetic and symbiotic evolution of two Bradyrhizobium strains inoculated on Acacia mangium in Malaysia and Senegal 15 and 5 years, respectively, after their introduction. Based on typing of several loci, we showed that these two strains, although closely related and originally sampled in Australia, evolved differently. One strain was recovered in soil with the same five loci as the original isolate, whereas the symbiotic cluster of the other strain was detected with no trace of the three housekeeping genes of the original inoculum. Moreover, the nitrogen fixation efficiency was variable among these isolates (either recombinant or not), with significantly high, low, or similar efficiencies compared to the two original strains and no significant difference between recombinant and nonrecombinant isolates. These data suggested that 15 years after their introduction, nitrogen-fixing bacteria remain in the soil but that closely related inoculant strains may not evolve in the same way, either genetically or symbiotically. In a context of increasing agronomical use of microbial inoculants (for biological control, nitrogen fixation, or plant growth promotion), this result feeds the debate on the consequences associated with such practices. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  10. A Framework for Safe Integration of Small UAS Into the NAS

    NASA Technical Reports Server (NTRS)

    Logan, Michael J.; Bland, Geoffrey; Murray, Jennifer

    2011-01-01

    This paper discusses a proposed framework for the safe integration of small unmanned aerial systems (sUAS) into the National Airspace System (NAS). The paper examines the potential uses of sUAS to build an understanding of the location and frequency of potential future flight operations based on the future applications of the sUAS systems. The paper then examines the types of systems that would be required to meet the application-level demand to determine classes of platforms and operations. Finally, a framework is proposed for both airworthiness and operations that attempts to balance safety with utility for these important systems.

  11. Butyrate modulates TGF-beta1 generation and function: potential renal benefit for Acacia(sen) SUPERGUM (gum arabic)?

    PubMed

    Matsumoto, N; Riley, S; Fraser, D; Al-Assaf, S; Ishimura, E; Wolever, T; Phillips, G O; Phillips, A O

    2006-01-01

    Anecdotal evidence suggests that high fibre supplementation of dietary intake may have health benefits in renal disease related to alterations in circulating levels of short-chain fatty acids. The aim of the study was to examine the hypothesis that dietary manipulation may increase serum butyrate and thus have potential beneficial effects in renal disease. We examined the effect of dietary supplementation with a gum arabic sample of standardized molecular characteristics, Acacia(sen) SUPERGUM EM2 (SUPERGUM), on systemic levels of butyrate in normal human subjects. In an in vitro study, we also examined the potential role of butyrate in modifying the generation of the profibrotic cytokine transforming growth factor-beta (TGF-beta1) by renal epithelial cells. Following 8 weeks of dietary supplementation with 25 g/day of SUPERGUM, there was a two-fold increase in serum butyrate (n=7, P=0.03). In vitro work demonstrated that exposure of renal epithelial cells to elevated concentrations of butyrate suppressed both basal and stimulated TGF-beta1 synthesis. The action of butyrate was mediated by suppression of the extracellular signal-regulated kinase/mitogen-activated protein kinase signalling pathway. In addition, butyrate exposures reduced the response of renal epithelial cells to TGF-beta1 as assessed by luciferase activity of a TGF-beta-responsive reporter construct. Attenuation of TGF-beta1 signalling was associated with reduced phosphorylation of Smad 3 and decreased trafficking of TGF-beta1 receptors into signalling, non-lipid raft-associated membrane fractions. In conclusion, the data demonstrate that dietary supplementation with SUPERGU increased serum butyrate, which at least in vitro has beneficial effects on renal pro-fibrotic cytokine generation.

  12. Evaluation of Gentamicin and Lidocaine Release Profile from Gum Acacia-crosslinked-poly(2-hydroxyethylmethacrylate)-carbopol Based Hydrogels.

    PubMed

    Singh, Baljit; Dhiman, Abhishek

    2017-01-01

    No doubt, the prevention of infection is an indispensable aspect of the wound management, but, simultaneous wound pain relief is also required. Therefore, herein this article, incorporation of antibiotic agent 'gentamicin' and pain relieving agent 'lidocaine' into hydrogel wound dressings, prepared by using acacia gum, carbopol and poly(2-hydroxyethylmethacrylate) polymers, has been carried out. The hydrogels were evaluated as a drug carrier for model drugs gentamicin and lidocaine. Synthesis of hydrogel wound dressing was carried out by free radical polymerization technique. The drug loading was carried out by swelling equilibrium method and gel strength of hydrogels was measured by a texture analyzer. Porous microstructure of the hydrogel was observed in cryo-SEM images. The hydrogel showed mesh size 37.29 nm, cross-link density 2.19× 10-5 mol/cm3, molecular weight between two cross-links 60.25× 10-3 g/mol and gel strength 0.625±0.112 N in simulated wound fluid. It is concluded that the pH of swelling medium has influenced the network structure of hydrogel i.e., molecular weight of the polymer chain between two neighboring cross links, crosslink density and the corresponding mesh size. A good correlation was established between gel strength and network parameters. Cryo-SEM images showed porous morphology of hydrogels. These hydrogels were found to be biodegradable and antimicrobial in nature. Drug release occurred through Fickian diffusion mechanism and release profile was best fitted in first order model. Overall it is concluded that modification in GA has led to formation of a porous hydrogels for wound dressing applications. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. The Interaction between Arbuscular Mycorrhizal Fungi and Endophytic Bacteria Enhances Plant Growth of Acacia gerrardii under Salt Stress

    PubMed Central

    Hashem, Abeer; Abd_Allah, Elsayed F.; Alqarawi, Abdulaziz A.; Al-Huqail, Asma A.; Wirth, Stephan; Egamberdieva, Dilfuza

    2016-01-01

    Microbes living symbiotically in plant tissues mutually cooperate with each other by providing nutrients for proliferation of the partner organism and have a beneficial effect on plant growth. However, few studies thus far have examined the interactive effect of endophytic bacteria and arbuscular mycorrhizal fungi (AMF) in hostile conditions and their potential to improve plant stress tolerance. In this study, we investigated how the synergistic interactions of endophytic bacteria and AMF affect plant growth, nodulation, nutrient acquisition and stress tolerance of Acacia gerrardii under salt stress. Plant growth varied between the treatments with both single inoculants and was higher in plants inoculated with the endophytic B. subtilis strain than with AMF. Co-inoculated A. gerrardii had a significantly greater shoot and root dry weight, nodule number, and leghemoglobin content than those inoculated with AMF or B. subtilis alone under salt stress. The endophytic B. subtilis could alleviate the adverse effect of salt on AMF colonization. The differences in nitrate and nitrite reductase and nitrogenase activities between uninoculated plants and those inoculated with AMF and B. subtilis together under stress were significant. Both inoculation treatments, either B. subtilis alone or combined with AMF, enhanced the N, P, K, Mg, and Ca contents and phosphatase activities in salt-stressed A. gerrardii tissues and reduced Na and Cl concentration, thereby protecting salt-stressed plants from ionic and osmotic stress-induced changes. In conclusion, our results indicate that endophytic bacteria and AMF contribute to a tripartite mutualistic symbiosis in A. gerrardii and are coordinately involved in the plant adaptation to salt stress tolerance. PMID:27486442

  14. UAS Integration Into the NAS: An Examination of Baseline Compliance in the Current Airspace System

    NASA Technical Reports Server (NTRS)

    Fern, Lisa; Kenny, Caitlin A.; Shively, Robert J.; Johnson, Walter

    2012-01-01

    As a result of the FAA Modernization and Reform Act of 2012, Unmanned Aerial Systems (UAS) are expected to be integrated into the National Airspace System (NAS) by 2015. Several human factors challenges need to be addressed before UAS can safely and routinely fly in the NAS with manned aircraft. Perhaps the most significant challenge is for the UAS to be non-disruptive to the air traffic management system. Another human factors challenge is how to provide UAS pilots with intuitive traffic information in order to support situation awareness (SA) of their airspace environment as well as a see-and-avoid capability comparable to manned aircraft so that a UAS pilot could safely maneuver the aircraft to maintain separation and collision avoidance if necessary. A simulation experiment was conducted to examine baseline compliance of UAS operations in the current airspace system. Researchers also examined the effects of introducing a Cockpit Situation Display (CSD) into a UAS Ground Control Station (GCS) on UAS pilot performance, workload and situation awareness while flying in a positively controlled sector. Pilots were tasked with conducting a highway patrol police mission with a Medium Altitude Long Endurance (MALE) UAS in L.A. Center airspace with two mission objectives: 1) to reroute the UAS when issued new instructions from their commander, and 2) to communicate with Air Traffic Control (ATC) to negotiate flight plan changes and respond to vectoring and altitude change instructions. Objective aircraft separation data, workload ratings, SA data, and subjective ratings regarding UAS operations in the NAS were collected. Results indicate that UAS pilots were able to comply appropriately with ATC instructions. In addition, the introduction of the CSD improved pilot SA and reduced workload associated with UAS and ATC interactions.

  15. Redshift and blueshift of GaNAs/GaAs multiple quantum wells induced by rapid thermal annealing

    NASA Astrophysics Data System (ADS)

    Sun, Yijun; Cheng, Zhiyuan; Zhou, Qiang; Sun, Ying; Sun, Jiabao; Liu, Yanhua; Wang, Meifang; Cao, Zhen; Ye, Zhi; Xu, Mingsheng; Ding, Yong; Chen, Peng; Heuken, Michael; Egawa, Takashi

    2018-02-01

    The effects of rapid thermal annealing (RTA) on the optical properties of GaNAs/GaAs multiple quantum wells (MQWs) grown by chemical beam epitaxy (CBE) are studied by photoluminescence (PL) at 77 K. The results show that the optical quality of the MQWs improves significantly after RTA. With increasing RTA temperature, PL peak energy of the MQWs redshifts below 1023 K, while it blueshifts above 1023 K. Two competitive processes which occur simultaneously during RTA result in redshift at low temperature and blueshift at high temperature. It is also found that PL peak energy shift can be explained neither by nitrogen diffusion out of quantum wells nor by nitrogen reorganization inside quantum wells. PL peak energy shift can be quantitatively explained by a modified recombination coupling model in which redshift nonradiative recombination and blueshift nonradiative recombination coexist. The results obtained have significant implication on the growth and RTA of GaNAs material for high performance optoelectronic device application.

  16. NAS Demand Predictions, Transportation Systems Analysis Model (TSAM) Compared with Other Forecasts

    NASA Technical Reports Server (NTRS)

    Viken, Jeff; Dollyhigh, Samuel; Smith, Jeremy; Trani, Antonio; Baik, Hojong; Hinze, Nicholas; Ashiabor, Senanu

    2006-01-01

    The current work incorporates the Transportation Systems Analysis Model (TSAM) to predict the future demand for airline travel. TSAM is a multi-mode, national model that predicts the demand for all long distance travel at a county level based upon population and demographics. The model conducts a mode choice analysis to compute the demand for commercial airline travel based upon the traveler s purpose of the trip, value of time, cost and time of the trip,. The county demand for airline travel is then aggregated (or distributed) to the airport level, and the enplanement demand at commercial airports is modeled. With the growth in flight demand, and utilizing current airline flight schedules, the Fratar algorithm is used to develop future flight schedules in the NAS. The projected flights can then be flown through air transportation simulators to quantify the ability of the NAS to meet future demand. A major strength of the TSAM analysis is that scenario planning can be conducted to quantify capacity requirements at individual airports, based upon different future scenarios. Different demographic scenarios can be analyzed to model the demand sensitivity to them. Also, it is fairly well know, but not well modeled at the airport level, that the demand for travel is highly dependent on the cost of travel, or the fare yield of the airline industry. The FAA projects the fare yield (in constant year dollars) to keep decreasing into the future. The magnitude and/or direction of these projections can be suspect in light of the general lack of airline profits and the large rises in airline fuel cost. Also, changes in travel time and convenience have an influence on the demand for air travel, especially for business travel. Future planners cannot easily conduct sensitivity studies of future demand with the FAA TAF data, nor with the Boeing or Airbus projections. In TSAM many factors can be parameterized and various demand sensitivities can be predicted for future travel. These

  17. Enhancement of photocurrent in epitaxial lift-off thin-film GaInNAsSb solar cells due to light-confinement structure

    NASA Astrophysics Data System (ADS)

    Miyashita, Naoya; Behaghel, Benoît; Guillemoles, Jean-François; Okada, Yoshitaka

    2018-07-01

    This work focuses on the characterization of GaInNAsSb solar cells whose substrates are removed via the epitaxial lift-off (ELO) technique. As a result of the substrate removal, increases in the photocurrent and the interference feature were clearly observed. This is clear evidence of the light-confinement effect, whereby some of the unabsorbed photons at the rear metal contact were reflected back towards the front side of the ELO thin-film cell. We successfully demonstrated that the ELO technique can be applied for the GaInNAsSb cell, and the light management should add flexibility in designing the cell structures.

  18. Salt tolerances of some mainland tree species select as through nursery screening.

    PubMed

    Miah, Md Abdul Quddus

    2013-09-15

    A study of salt tolerance was carried out on germination, survival and height growth performance of important mesophytic species such as Acacia auriculiformis, Acacia hybrid, Artocarpus heterophyllus, Albizia procera, Albizia lebbeck, Acacia nilotica, Achras sapota, Casuarina equisetifolaia, Emblica officinalis, Leucaena leucocephala, Samania saman, Swetenia macrophylla, Terminalia arjuna, Tamarindus indica, Terminalia bellirica and Thespesia populnea in nursery stage using fresh water and salt (NaCl) solutions of 10, 15 and 20 ppm. Effect of salt on germination, survival performance and height growth performance were examined in this condition. Based on the observation, salt tolerance of these species has been determined Acacia auriculiformis, Acacia hybrid, Achras sapota, Casuarina equisetifolia, Leucaena leucocephala and Tamarindus indica has showed the best capacity to perform in different salinity conditions. Acacia nilotica, Emblica officinalis, Thespesia populnea has performed better. Albizia procera, Samania saman and Terminalia bellirica, germination and height performance showed good but when salinity increases survivability were decreases.

  19. Unmanned Aircraft Systems (UAS): Addressing the Regulatory Issues for National Airspace System (NAS) Integration

    DTIC Science & Technology

    2009-04-01

    terms of IFR operations or passenger enplanements. The configuration of each Class B airspace area is individually tailored and consists of a surface...are serviced by a radar approach control, and that have a certain number of IFR operations or passenger enplanements. Although the configuration of...ft MSL Figure 3 depicts DoD UASs operating in their respective NAS classifications: Global Hawk Predator B Transponder See & Avoid DME IFR

  20. Shrub biomass production following simulated herbivory: A test of the compensatory growth hypothesis

    Treesearch

    Terri B. Teaschner; Timothy E. Fulbright

    2007-01-01

    The objective of this experiment was to test the hypotheses that 1) simulated herbivory stimulates increased biomass production in spiny hackberry (Celtis pallida), but decreases biomass production in blackbrush acacia (Acacia rigidula) compared to unbrowsed plants and 2) thorn density and length increase in blackbrush acacia to a...

  1. Operational Overview for Unmanned Aircraft Systems (UAS) Integration in the National Airspace (NAS) Project Flight Test Series 3

    NASA Technical Reports Server (NTRS)

    Valkov, Steffi

    2017-01-01

    This presentation is a high level overview of the flight testing that took place in 2015 for the UAS-NAS project. All topics in the presentation discussed at a high level and no technical details are provided.

  2. Emission factors of particulate matter, polycyclic aromatic hydrocarbons, and levoglucosan from wood combustion in south-central Chile.

    PubMed

    Jimenez, Jorge; Farias, Oscar; Quiroz, Roberto; Yañez, Jorge

    2017-07-01

    In south-central Chile, wood stoves have been identified as an important source of air pollution in populated areas. Eucalyptus (Eucalyptus globulus), Chilean oak (Nothofagus oblique), and mimosa (Acacia dealbata) were burned in a single-chamber slow-combustion wood stove at a controlled testing facility located at the University of Concepción, Chile. In each experiment, 2.7-3.1 kg of firewood were combusted while continuously monitoring temperature, exhaust gases, burn rate, and collecting particulate matter samples in Teflon filters under isokinetic conditions for polycyclic aromatic hydrocarbon and levoglucosan analyses. Mean particulate matter emission factors were 2.03, 4.06, and 3.84 g/kg dry wood for eucalyptus, oak, and mimosa, respectively. The emission factors were inversely correlated with combustion efficiency. The mean emission factors of the sums of 12 polycyclic aromatic hydrocarbons in particle phases were 1472.5, 2134.0, and 747.5 μg/kg for eucalyptus, oak, and mimosa, respectively. Fluoranthene, pyrene, benzo[a]anthracene, and chrysene were present in the particle phase in higher proportions compared with other polycyclic aromatic hydrocarbons that were analyzed. Mean levoglucosan emission factors were 854.9, 202.3, and 328.0 mg/kg for eucalyptus, oak, and mimosa, respectively. Since the emissions of particulate matter and other pollutants were inversely correlated with combustion efficiency, implementing more efficient technologies would help to reduce air pollutant emissions from wood combustion. Residential wood burning has been identified as a significant source of air pollution in populated areas. Local wood species are combusted for home cooking and heating, which releases several toxic air pollutants, including particulate matter, carbon monoxide, and polycyclic aromatic hydrocarbons. Air pollutant emissions depend on the type of wood and the technology and operational conditions of the wood stove. A better understanding of emissions from

  3. Genetic diversity of symbiotic Bradyrhizobium elkanii populations recovered from inoculated and non-inoculated Acacia mangium field trials in Brazil.

    PubMed

    Perrineau, M M; Le Roux, C; de Faria, S M; de Carvalho Balieiro, F; Galiana, A; Prin, Y; Béna, G

    2011-07-01

    Acacia mangium is a legume tree native to Australasia. Since the eighties, it has been introduced into many tropical countries, especially in a context of industrial plantations. Many field trials have been set up to test the effects of controlled inoculation with selected symbiotic bacteria versus natural colonization with indigenous strains. In the introduction areas, A. mangium trees spontaneously nodulate with local and often ineffective bacteria. When inoculated, the persistence of inoculants and possible genetic recombination with local strains remain to be explored. The aim of this study was to describe the genetic diversity of bacteria spontaneously nodulating A. mangium in Brazil and to evaluate the persistence of selected strains used as inoculants. Three different sites, several hundred kilometers apart, were studied, with inoculated and non-inoculated plots in two of them. Seventy-nine strains were isolated from nodules and sequenced on three housekeeping genes (glnII, dnaK and recA) and one symbiotic gene (nodA). All but one of the strains belonged to the Bradyrhizobium elkanii species. A single case of housekeeping gene transfer was detected among the 79 strains, suggesting an extremely low rate of recombination within B. elkanii, whereas the nodulation gene nodA was found to be frequently transferred. The fate of the inoculant strains varied depending on the site, with a complete disappearance in one case, and persistence in another. We compared our results with the sister species Bradyrhizobium japonicum, both in terms of population genetics and inoculant strain destiny. Copyright © 2011 Elsevier GmbH. All rights reserved.

  4. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project. NASA Contributions to the SARP WC Definition

    NASA Technical Reports Server (NTRS)

    Randall, Debra K.; Consiglio, Maria Cristina; Santiago, Confesor

    2014-01-01

    To better inform sense and avoid research needs and to understand ongoing investigation of potential solutions that ultimately lead to the assisting the FAA with their Congressional mandate to fly UAS in the NAS.

  5. Remotely Operated Aircraft (ROA) Impact on the National Airspace System (NAS) Work Package, 2005: Composite Report on FAA Flight Plan and Operational Evaluation Plan. Version 7.0

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The purpose of this document is to present the findings that resulted from a high-level analysis and evaluation of the following documents: (1) The OEP (Operational Evolution Plan) Version 7 -- a 10-year plan for operational improvements to increase capacity and efficiency in U.S. air travel and transport and other use of domestic airspace. The OEP is the FAA commitment to operational improvements. It is outcome driven, with clear lines of accountability within FAA organizations. The OEP concentrates on operational solutions and integrates safety, certification, procedures, staffing, equipment, avionics and research; (2) The Draft Flight Plan 2006 through 2010 -- a multi-year strategic effort, setting a course for the FAA through 2001, to provide the safest and most efficient air transportation system in the world; (3) The NAS System Architecture Version 5 -- a blueprint for modernizing the NAS and improving NAS services and capabilities through the year 2015; and (4) The NAS-SR-1000 System Requirements Specification (NASSRS) -- a compilation of requirements which describe the operational capabilities for the NAS. The analysis is particularly focused on examining the documents for relevance to existing and/or planned future UAV operations. The evaluation specifically focuses on potential factors that could materially affect the development of a commercial ROA industry, such as: (1) Design limitations of the CNS/ATM system, (2) Human limitations, The information presented was taken from program specifications or program office lead personnel.

  6. EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments (External Review Draft)

    EPA Science Inventory

  1. The effect of cathode felt geometries on electrochemical characteristics of sodium sulfur (NaS) cells: Planar vs. tubular

    NASA Astrophysics Data System (ADS)

    Kim, Goun; Park, Yoon-Cheol; Lee, Younki; Cho, Namung; Kim, Chang-Soo; Jung, Keeyoung

    2016-09-01

    Two sodium sulfur (NaS) cells, one with a planar design and the other with a tubular design, were subject to discharge-charge cycles in order to investigate the effect of cathode felt geometries on electrochemical characteristics of NaS cells. Their discharge-charge behaviors over 200 cycles were evaluated at the operation temperature of 350 °C with the current densities of 100 mA cm-2 for discharge and 80 mA cm-2 for charge. The results showed that the deviation from theoretical open circuit voltage changes of a planar cell was smaller than those of a tubular cell resulting in potential specific power loss reduction during operation. In order to understand the effect, a three dimensional statistically representative matrix for a cathode felt has been generated using experimentally measured data. It turns out that the area specific fiber number density in the outer side area of a tubular cathode felt is smaller than that of a planar felt resulting in occurrence of larger voltage drops via retarded convection of cathode melts during cell operation.

  2. National Academy of Sciences (NAS) Study entitled The Effect of Climate Change on Indoor Air Quality and Public Health.

    EPA Science Inventory

    The Institute of Medicine of the NAS is conducting a study to evaluate the state of scientific understanding of the effects of climate change on indoor air quality and public health. General topics may include the likely impacts of climate change in the U.S. on the indoor environ...

  3. 75 FR 33615 - Draft EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments (EPA...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-14

    ... the IRIS Program, EPA provides the highest quality science-based human health assessments to support... comments included in the National Academy of Sciences (NAS) 2006 report. In addition, it includes new analyses on potential human effects that may result from exposure to 2,3,7,8- tetrachlorodibenzo-p-dioxin...

  4. Assessment of Acacia Koa Forest Health across Environmental Gradients in Hawai‘i Using Fine Resolution Remote Sensing and GIS

    PubMed Central

    Morales, Rodolfo Martinez; Idol, Travis; Friday, James B.

    2011-01-01

    Koa (Acacia koa) forests are found across broad environmental gradients in the Hawai‘ian Islands. Previous studies have identified koa forest health problems and dieback at the plot level, but landscape level patterns remain unstudied. The availability of high-resolution satellite images from the new GeoEye1 satellite offers the opportunity to conduct landscape-level assessments of forest health. The goal of this study was to develop integrated remote sensing and geographic information systems (GIS) methodologies to characterize the health of koa forests and model the spatial distribution and variability of koa forest dieback patterns across an elevation range of 600–1,000 m asl in the island of Kaua‘i, which correspond to gradients of temperature and rainfall ranging from 17–20 °C mean annual temperature and 750–1,500 mm mean annual precipitation. GeoEye1 satellite imagery of koa stands was analyzed using supervised classification techniques based on the analysis of 0.5-m pixel multispectral bands. There was clear differentiation of native koa forest from areas dominated by introduced tree species and differentiation of healthy koa stands from those exhibiting dieback symptoms. The area ratio of healthy koa to koa dieback corresponded linearly to changes in temperature across the environmental gradient, with koa dieback at higher relative abundance in warmer areas. A landscape-scale map of healthy koa forest and dieback distribution demonstrated both the general trend with elevation and the small-scale heterogeneity that exists within particular elevations. The application of these classification techniques with fine spatial resolution imagery can improve the accuracy of koa forest inventory and mapping across the islands of Hawai‘i. Such findings should also improve ecological restoration, conservation and silviculture of this important native tree species. PMID:22163920

  5. Assessment of Acacia koa forest health across environmental gradients in Hawai'i using fine resolution remote sensing and GIS.

    PubMed

    Morales, Rodolfo Martinez; Idol, Travis; Friday, James B

    2011-01-01

    Koa (Acacia koa) forests are found across broad environmental gradients in the Hawai'ian Islands. Previous studies have identified koa forest health problems and dieback at the plot level, but landscape level patterns remain unstudied. The availability of high-resolution satellite images from the new GeoEye1 satellite offers the opportunity to conduct landscape-level assessments of forest health. The goal of this study was to develop integrated remote sensing and geographic information systems (GIS) methodologies to characterize the health of koa forests and model the spatial distribution and variability of koa forest dieback patterns across an elevation range of 600-1,000 m asl in the island of Kaua'i, which correspond to gradients of temperature and rainfall ranging from 17-20 °C mean annual temperature and 750-1,500 mm mean annual precipitation. GeoEye1 satellite imagery of koa stands was analyzed using supervised classification techniques based on the analysis of 0.5-m pixel multispectral bands. There was clear differentiation of native koa forest from areas dominated by introduced tree species and differentiation of healthy koa stands from those exhibiting dieback symptoms. The area ratio of healthy koa to koa dieback corresponded linearly to changes in temperature across the environmental gradient, with koa dieback at higher relative abundance in warmer areas. A landscape-scale map of healthy koa forest and dieback distribution demonstrated both the general trend with elevation and the small-scale heterogeneity that exists within particular elevations. The application of these classification techniques with fine spatial resolution imagery can improve the accuracy of koa forest inventory and mapping across the islands of Hawai'i. Such findings should also improve ecological restoration, conservation and silviculture of this important native tree species.

  6. MOVPE growth studies of Ga(NAsP)/(BGa)(AsP) multi quantum well heterostructures (MQWH) for the monolithic integration of laser structures on (001) Si-substrates

    NASA Astrophysics Data System (ADS)

    Ludewig, P.; Reinhard, S.; Jandieri, K.; Wegele, T.; Beyer, A.; Tapfer, L.; Volz, K.; Stolz, W.

    2016-03-01

    High-quality, pseudomorphically strained Ga(NAsP)/(BGa)(AsP)-multiple quantum well heterostructures (MQWH) have been deposited on exactly oriented (001) Si-substrate by metal organic vapour phase epitaxy (MOVPE) in a wide temperature range between 525 °C and 700 °C. The individual atomic incorporation efficiencies, growth rates as well as nanoscale material properties have been clarified by applying detailed high-resolution X-ray diffraction (HR-XRD), photoluminescence (PL) spectroscopy and high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) studies. An almost constant N-incorporation efficiency is obtained for a wide growth temperature range from 550 °C up to 650 °C. The P-incorporation is steadily increasing with increasing growth temperature reaching values at high temperatures in excess of the applied gas phase ratio. While the lower interface from the binary GaP- to the quaternary Ga(NAsP)-material system is very sharp, the upper interface is significantly rougher with a roughness scale of ±0.43 nm in quantum well thickness variation at a growth temperature of 525 °C. This roughness scale increases steadily with increasing growth temperature. No indication of any phase separation effects is detected in the Ga(NAsP)-material system even at the highest growth temperature of 700 °C. The obtained experimental results are briefly discussed with respect to the anticipated metastable character of the novel dilute-nitride Ga(NAsP)-material system grown lattice-matched to (001) Si-substrate.

  7. NAS Parallel Benchmark Results 11-96. 1.0

    NASA Technical Reports Server (NTRS)

    Bailey, David H.; Bailey, David; Chancellor, Marisa K. (Technical Monitor)

    1997-01-01

    The NAS Parallel Benchmarks have been developed at NASA Ames Research Center to study the performance of parallel supercomputers. The eight benchmark problems are specified in a "pencil and paper" fashion. In other words, the complete details of the problem to be solved are given in a technical document, and except for a few restrictions, benchmarkers are free to select the language constructs and implementation techniques best suited for a particular system. These results represent the best results that have been reported to us by the vendors for the specific 3 systems listed. In this report, we present new NPB (Version 1.0) performance results for the following systems: DEC Alpha Server 8400 5/440, Fujitsu VPP Series (VX, VPP300, and VPP700), HP/Convex Exemplar SPP2000, IBM RS/6000 SP P2SC node (120 MHz), NEC SX-4/32, SGI/CRAY T3E, SGI Origin200, and SGI Origin2000. We also report High Performance Fortran (HPF) based NPB results for IBM SP2 Wide Nodes, HP/Convex Exemplar SPP2000, and SGI/CRAY T3D. These results have been submitted by Applied Parallel Research (APR) and Portland Group Inc. (PGI). We also present sustained performance per dollar for Class B LU, SP and BT benchmarks.

  8. Performance Analysis of the NAS Y-MP Workload

    NASA Technical Reports Server (NTRS)

    Bergeron, Robert J.; Kutler, Paul (Technical Monitor)

    1997-01-01

    This paper describes the performance characteristics of the computational workloads on the NAS Cray Y-MP machines, a Y-MP 832 and later a Y-MP 8128. Hardware measurements indicated that the Y-MP workload performance matured over time, ultimately sustaining an average throughput of 0.8 GFLOPS and a vector operation fraction of 87%. The measurements also revealed an operation rate exceeding 1 per clock period, a well-balanced architecture featuring a strong utilization of vector functional units, and an efficient memory organization. Introduction of the larger memory 8128 increased throughput by allowing a more efficient utilization of CPUs. Throughput also depended on the metering of the batch queues; low-idle Saturday workloads required a buffer of small jobs to prevent memory starvation of the CPU. UNICOS required about 7% of total CPU time to service the 832 workloads; this overhead decreased to 5% for the 8128 workloads. While most of the system time went to service I/O requests, efficient scheduling prevented excessive idle due to I/O wait. System measurements disclosed no obvious bottlenecks in the response of the machine and UNICOS to the workloads. In most cases, Cray-provided software tools were- quite sufficient for measuring the performance of both the machine and operating, system.

  9. Contain or eradicate? Optimizing the management goal for Australian acacia invasions in the face of uncertainty

    USGS Publications Warehouse

    Moore, J.L.; Runge, M.C.; Webber, B.L.; Wilson, J.R.U.

    2011-01-01

    Aim To identify whether eradication or containment is expected to be the most cost-effective management goal for an isolated invasive population when knowledge about the current extent is uncertain. Location Global and South Africa. Methods We developed a decision analysis framework to analyse the best management goal for an invasive species population (eradication, containment or take no action) when knowledge about the current extent is uncertain. We used value of information analysis to identify when investment in learning about the extent will improve this decision-making and tested the sensitivity of the conclusions to different parameters (e.g. spread rate, maximum extent, and management efficacy and cost). The model was applied to Acacia paradoxa DC, an Australian shrub with an estimated invasive extent of 310ha on Table Mountain, South Africa. Results Under the parameters used, attempting eradication is cost-effective for infestations of up to 777ha. However, if the invasion extent is poorly known, then attempting eradication is only cost-effective for infestations estimated as 296ha or smaller. The value of learning is greatest (maximum of 8% saving) when infestation extent is poorly known and if it is close to the maximum extent for which attempting eradication is optimal. The optimal management action is most sensitive to the probability that the action succeeds (which depends on the extent), with the discount rate and cost of management also important, but spread rate less so. Over a 20-year time-horizon, attempting to eradicate A. paradoxa from South Africa is predicted to cost on average ZAR 8 million if the extent is known, and if our current estimate is poor, ZAR 33.6 million as opposed to ZAR 32.8 million for attempting containment. Main conclusions Our framework evaluates the cost-effectiveness of attempting eradication or containment of an invasive population that takes uncertainty in population extent into account. We show that incorporating

  10. Recovery of symbiotic nitrogen fixing acacia rhizobia from Merzouga Desert sand dunes in South East Morocco--Identification of a probable new species of Ensifer adapted to stressed environments.

    PubMed

    Sakrouhi, Ilham; Belfquih, Meryem; Sbabou, Laïla; Moulin, Patricia; Bena, Gilles; Filali-Maltouf, Abdelkarim; Le Quéré, Antoine

    2016-03-01

    Bacteria capable of nodulating Acacia tortilis and A. gummifera could be recovered from sand dunes collected in the Moroccan Merzouga desert. The trapping approach enabled the recovery of 17 desert rhizobia that all clustered within the Ensifer (Sinorhizobium) genus. Four isolates of the dominant genotype comprising 15 strains as well as 2 divergent strains were further characterized by MLSA. Phylogenetic analyzes indicated that the dominant genetic type was belonging to a new and yet undefined species within the Ensifer genus. Interestingly, housekeeping gene phylogenies showed that this possibly new species is also present in another desert but in India. Phylogenetic analyses of nifH and nodC sequences showed high sequence conservation among the Moroccan strains belonging to the dominant genotype but high divergence with sequences from Indian isolates suggesting acquisition of symbiotic genes through Horizontal Gene Transfer. These desert rhizobia were capable of growing in media containing high salt concentrations, under high pH and most of the strains showed growth at 45°C. Only recovered from desert type of Biome, yet, this new taxon appears particularly adapted to such harsh environment. Copyright © 2016 Elsevier GmbH. All rights reserved.

  11. About the Las Acacias, Trelew and Vassouras Magnetic Observatories Monitoring the South Atlantic Magnetic Anomaly Region Response to an Interplanetary Coronal Mass Ejection

    NASA Astrophysics Data System (ADS)

    Gianibelli, J. C.; Quaglino, N. M.

    2007-05-01

    The South Atlantic Magnetic Anomaly (SAMA) Region presents evolutive characteristics very important as were observed by a variety of satelital sensors. Important Magnetic Observatories with digital record monitor the effects of the Sun-Earth interaction, such as San Juan de Puerto Rico (SJG), Kourou (KOU), Vassouras (VSS), Las Acacias (LAS), Trelew (TRW), Vernadsky (AIA), Hermanus (HER) and Huancayo (HUA). In the present work we present the features registered during the geomagnetic storm in January 21, 2005, produced by a geoeffective Coronal Mass Ejection (CME) whose Interplanetary Coronal Mass Ejection (ICME) was detected by the instrumental onboard the Advanced Composition Explorer (ACE) Sonde. We analize how the Magnetic Total Intensity records at VSS, TRW and LAS Observatories shows the effect of the entering particles to ionospherical dephts producing a field enhancement following the first Interplanetary Shock (IP) arrival of the ICME. This process manifest in the digital record as an increment over the magnetospheric Ring Current field effect and superinpossed effects over the Antarctic Auroral Electrojet. The analysis and comparison of the records demonstrate that the Ring Current effects are important in SJG and KOU but not in VSS, LAS and TRW observatories, concluding that SAMA region shows a enhancement of the ionospherical currents oposed to those generated at magnetospheric heighs. Moreover in TRW, 5 hours after the ICME shock arrival, shows the effect of the Antarctic Auroral Electrojet counteracting to fields generated by the Ring Current.

  12. A Combination of Scutellaria Baicalensis and Acacia Catechu Extracts for Short-Term Symptomatic Relief of Joint Discomfort Associated with Osteoarthritis of the Knee

    PubMed Central

    Ormsbee, Lauren T.; Elam, Marcus L.; Campbell, Sara C.; Rahnama, Nader; Payton, Mark E.; Brummel-Smith, Ken; Daggy, Bruce P.

    2014-01-01

    Abstract The extracts of Scutellaria baicalensis and Acacia catechu have been shown in previous studies to alleviate joint discomfort, reduce stiffness, and improve mobility by reducing the production of proinflammatory molecules over long periods of supplementation. The acute effects of intake of these extracts have not yet been investigated. Thus, we carried out a 1 week clinical trial to examine the extent to which UP446—a natural proprietary blend of S. baicalensis and A. catechu (UP446)—decreases knee joint pain, mobility, and biomarkers of inflammation in comparison to naproxen. Seventy-nine men and women (40–90 years old) diagnosed as having mild to moderate osteoarthritis (OA) consumed either 500 mg/day of the UP446 supplement or 440 mg/day of naproxen for 1 week in a double-blind randomized control trial. Pain, knee range of motion (ROM), and overall physical activity were evaluated at the start and at the end of treatment. Fasting blood was collected to determine serum interleukins 1β and 6, tumor necrosis factor-α, C-reactive protein, and hyaluronic acid. The UP446 group experienced a significant decrease in perceived pain (P=.009) time dependently. Stiffness was significantly reduced by both treatments (P=.002 UP446, P=.008 naproxen). Significant increases in mean ROM over time (P=.04) were found in the UP446 group. These findings suggest that UP446 is effective in reducing the physical symptoms associated with knee OA. PMID:24611484

  13. [Scientific and practical activity of the Department of Muscle Biochemistry of the Palladin Institute of Biochemistry of NAS of Ukraine].

    PubMed

    Vynogradova, R P; Danilova, V M; Yurasova, S P

    2017-01-01

    The article focuses on scientific and practical activity of the Department of Muscle Biochemistry of the Palladin Institute of Biochemistry of NAS of Ukraine in the context of its foundation and development. Main findings and practical achievements in the area of muscle biochemistry are summarized and discussed.

  14. EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments (Volume 1) (Interagency Science Discussion Draft)

    EPA Science Inventory

    EPA is releasing the draft report, EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments (Volume 1), that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the Serious Gaming for Test & Evaluation of Clean-Slate (Ab Initio) National Airspace System (NAS) Designs

    NASA Technical Reports Server (NTRS)

    Allen, B. Danette; Alexandrov, Natalia

    2016-01-01

    Incremental approaches to air transportation system development inherit current architectural constraints, which, in turn, place hard bounds on system capacity, efficiency of performance, and complexity. To enable airspace operations of the future, a clean-slate (ab initio) airspace design(s) must be considered. This ab initio National Airspace System (NAS) must be capable of accommodating increased traffic density, a broader diversity of aircraft, and on-demand mobility. System and subsystem designs should scale to accommodate the inevitable demand for airspace services that include large numbers of autonomous Unmanned Aerial Vehicles and a paradigm shift in general aviation (e.g., personal air vehicles) in addition to more traditional aerial vehicles such as commercial jetliners and weather balloons. The complex and adaptive nature of ab initio designs for the future NAS requires new approaches to validation, adding a significant physical experimentation component to analytical and simulation tools. In addition to software modeling and simulation, the ability to exercise system solutions in a flight environment will be an essential aspect of validation. The NASA Langley Research Center (LaRC) Autonomy Incubator seeks to develop a flight simulation infrastructure for ab initio modeling and simulation that assumes no specific NAS architecture and models vehicle-to-vehicle behavior to examine interactions and emergent behaviors among hundreds of intelligent aerial agents exhibiting collaborative, cooperative, coordinative, selfish, and malicious behaviors. The air transportation system of the future will be a complex adaptive system (CAS) characterized by complex and sometimes unpredictable (or unpredicted) behaviors that result from temporal and spatial interactions among large numbers of participants. A CAS not only evolves with a changing environment and adapts to it, it is closely coupled to all systems that constitute the environment. Thus, the ecosystem that

  15. Natural biopolymer for preservation of microorganisms during sampling and storage.

    PubMed

    Sorokulova, Iryna; Watt, James; Olsen, Eric; Globa, Ludmila; Moore, Timothy; Barbaree, James; Vodyanoy, Vitaly

    2012-01-01

    Stability of microbial cultures during sampling and storage is a vital issue in various fields of medicine, biotechnology, food science, and forensics. We have developed a unique bacterial preservation process involving a non-toxic, water-soluble acacia gum polymer that eliminates the need for refrigerated storage of samples. The main goal of this study is to characterize the efficacy of acacia gum polymer for preservation of pathogenic bacteria (Bacillus anthracis and methicillin-resistant Staphylococcus aureus-MRSA) on different materials, used for swabbing and filtration: cotton, wool, polyester, rayon, charcoal cloth, and Whatman paper. Acacia gum polymer used for preservation of two pathogens has been shown to significantly protect bacteria during dehydration and storage in all tested samples at the range of temperatures (5-45°C for MRSA and 40-90°C for B. anthracis). Our results showed higher recovery as well as higher viability during the storage of both bacteria in all materials with acacia gum. Addition of acacia gum polymer to swabbing materials or filters will increase efficacy of sample collection and identification of pathogenic bacteria from locations such as hospitals or the environment. Proposed approach can also be used for long-term storage of culture collections, since acacia gum contributes to viability and stability of bacterial cultures. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Positive versus negative environmental impacts of tree encroachment in South Africa

    NASA Astrophysics Data System (ADS)

    Grellier, Séraphine; Ward, David; Janeau, Jean-Louis; Podwojewski, Pascal; Lorentz, Simon; Abbadie, Luc; Valentin, Christian; Barot, Sébastien

    2013-11-01

    Woody plant encroachment in grasslands is a worldwide phenomenon. Despite many studies, the consequences of woody plant encroachment on sub-canopy vegetation and soil properties are still unclear. To better understand the impacts of trees on grassland properties we examined the following questions using a mountainous sub-tropical grassland of South Africa encroached by an indigenous tree, Acacia sieberiana as a case study: (1) Do trees increase sub-canopy herbaceous diversity, quality and biomass and soil nitrogen content? (2) Do large trees have a stronger effect than medium-sized trees on grass and soil properties? (3) Does the impact of trees change with the presence of livestock and position of trees in a catena? We studied grass and non-graminoid species diversity and biomass, grass quality and soil properties during the wet season of 2009. Nitrogen in grass leaves, soil cation exchange capacity and calcium and magnesium ion concentrations in the soil increased under tall Acacia versus open areas. Medium-sized Acacia decreased the gross energy content, digestibility and neutral detergent fibre of grasses but increased the species richness of non-graminoids. Tall and medium Acacia trees were associated with the presence of Senecio inaequidens, an indigenous species that is toxic to horses and cattle. The presence of livestock resulted in a decrease in herbaceous root biomass and an increase in soil carbon and leaf biomass of grass under Acacia. Tree position in the catena did not modify the impact of trees on the herbaceous layer and soil properties. For management of livestock we recommend retaining tall Acacia trees and partially removing medium-sized Acacia trees because the latter had negative effects on grass quality.

  17. Aeronautics Research Mission Directorate Integrated Systems Research Program (ISRP) and UAS Integration in the NAS Project

    NASA Technical Reports Server (NTRS)

    Wolfe, Jean

    2010-01-01

    Program Goal: Conduct research at an integrated system-level on promising concepts and technologies and explore, assess, or demonstrate the benefits in a relevant environment.Criteria for selection of projects for Integrated Systems Research: a) Technology has attained enough maturity in the foundational research program that they merit more in-depth evaluation at an integrated system level in a relevant environment. b) Technologies which systems analysis indicates have the most potential for contributing to the simultaneous attainment of goals. c) Technologies identified through stakeholder input as having potential for simultaneous attainment of goals. d) Research not being done by other government agencies and appropriate for NASA to conduct. e) Budget augmentation. Environmentally Responsible Aviation (ERA) Project Explore and assess new vehicle concepts and enabling technologies through system-level experimentation to simultaneously reduce fuel burn, noise, and emissions Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project Contribute capabilities that reduce technical barriers related to the safety and operational challenges associated with enabling routine UAS access to the NAS Innovative Concepts for Green Aviation (ICGA) Project Spur innovation by offering research opportunities to the broader aeronautics community through peer-reviewed proposals, with a focus on making aviation more eco-friendly. Establish incentive prizes similar to the Centennial Challenges and sponsor innovation demonstrations of selected technologies that show promise of reducing aviation s impact on the environment

  18. Native and domestic browsers and grazers reduce fuels, fire temperatures, and acacia ant mortality in an African savanna.

    PubMed

    Kimuyu, Duncan M; Sensenig, Ryan L; Riginos, Corinna; Veblen, Kari E; Young, Truman P

    2014-06-01

    Despite the importance of fire and herbivory in structuring savanna systems, few replicated experiments have examined the interactive effects of herbivory and fire on plant dynamics. In addition, the effects of fire on associated ant-tree mutualisms have been largely unexplored. We carried out small controlled burns in each of 18 herbivore treatment plots of the Kenya Long-term Exclosure Experiment (KLEE), where experimentally excluding elephants has resulted in 42% greater tree densities. The KLEE design includes six different herbivore treatments that allowed us to examine how different combinations of megaherbivore wildlife, mesoherbivore wildlife, and cattle affect fire temperatures and subsequent loss of ant symbionts from Acacia trees. Before burning, we quantified herbaceous fuel loads and plant community composition. We tagged all trees, measured their height and basal diameter, and identified the resident ant species on each. We recorded weather conditions during the burns and used ceramic tiles painted with fire-sensitive paints to estimate fire temperatures at different heights and in different microsites (under vs. between trees). Across all treatments, fire temperatures were highest at 0-50 cm off the ground and hotter in the grass under trees than in the grassy areas between trees. Plots with more trees burned hotter than plots with fewer trees, perhaps because of greater fine woody debris. Plots grazed by wildlife and by cattle prior to burning had lower herbaceous fuel loads and experienced lower burn temperatures than ungrazed plots. Many trees lost their ant colonies during the burns. Ant survivorship differed by ant species and at the plot level was positively associated with previous herbivory (and lower fire temperatures). Across all treatments, ant colonies on taller trees were more likely to survive, but even some of the tallest trees lost their ant colonies. Our study marks a significant step in understanding the mechanisms that underlie the

  19. 78 FR 21084 - Proposed Amendment of Class D and E Airspace, and Establishment of Class E Airspace; Oceana NAS, VA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ... Control Tower at Oceana NAS (Apollo Soucek Field) operating on a part time basis. This action would... facility to part time. The geographic coordinates of the airport also would be adjusted to coincide with... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 71 [Docket No. FAA-2013...

  1. Security Risk Assessment Process for UAS in the NAS CNPC Architecture

    NASA Technical Reports Server (NTRS)

    Iannicca, Dennis C.; Young, Dennis P.; Thadani, Suresh K.; Winter, Gilbert A.

    2013-01-01

    This informational paper discusses the risk assessment process conducted to analyze Control and Non-Payload Communications (CNPC) architectures for integrating civil Unmanned Aircraft Systems (UAS) into the National Airspace System (NAS). The assessment employs the National Institute of Standards and Technology (NIST) Risk Management framework to identify threats, vulnerabilities, and risks to these architectures and recommends corresponding mitigating security controls. This process builds upon earlier work performed by RTCA Special Committee (SC) 203 and the Federal Aviation Administration (FAA) to roadmap the risk assessment methodology and to identify categories of information security risks that pose a significant impact to aeronautical communications systems. A description of the deviations from the typical process is described in regards to this aeronautical communications system. Due to the sensitive nature of the information, data resulting from the risk assessment pertaining to threats, vulnerabilities, and risks is beyond the scope of this paper.

  2. Security Risk Assessment Process for UAS in the NAS CNPC Architecture

    NASA Technical Reports Server (NTRS)

    Iannicca, Dennis Christopher; Young, Daniel Paul; Suresh, Thadhani; Winter, Gilbert A.

    2013-01-01

    This informational paper discusses the risk assessment process conducted to analyze Control and Non-Payload Communications (CNPC) architectures for integrating civil Unmanned Aircraft Systems (UAS) into the National Airspace System (NAS). The assessment employs the National Institute of Standards and Technology (NIST) Risk Management framework to identify threats, vulnerabilities, and risks to these architectures and recommends corresponding mitigating security controls. This process builds upon earlier work performed by RTCA Special Committee (SC) 203 and the Federal Aviation Administration (FAA) to roadmap the risk assessment methodology and to identify categories of information security risks that pose a significant impact to aeronautical communications systems. A description of the deviations from the typical process is described in regards to this aeronautical communications system. Due to the sensitive nature of the information, data resulting from the risk assessment pertaining to threats, vulnerabilities, and risks is beyond the scope of this paper

  3. Screening of antibacterial potentials of some medicinal plants from Melghat forest in India.

    PubMed

    Tambekar, D H; Khante, B S; Chandak, B R; Titare, A S; Boralkar, S S; Aghadte, S N

    2009-05-07

    Cyperus rotundus, Caesalpinia bonducella, Tinospora cordifolia, Gardenia gummifera, Ailanthus excelsa, Acacia arabica, Embelia ribes and Ventilago maderspatana from Melghat forest were screened for their antibacterial potential against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Proteus vulgaris, Salmonella typhi, Shigella flexneri, Salmonella paratyphi, Salmonella typhimurium, Pseudomonas aeruginosa, Enterobacter aerogenes by disc diffusion method. Out of these medicinal plants Caesalpinia bonducella, Gardenia gummifera and Acacia arabica showed remarkable antibacterial potential. The phytochemical analysis had showed the presence of Cardiac glycosides in all extracts (aqueous, acetone, ethanol and methanol) of Acacia arabica, Gardenia gummifera and ethanol, methanol extracts of Caesalpinia bonducella. Flavonoids were present in Gardenia gummifera, Ailanthus excelsa and acetone, methanol extracts of Acacia Arabica. Tannins and phenolic were present in Cyperus rotundus, Embelia ribes, and organic extracts of Ventilago maderspatana.

  4. GaInNAsSb/GaAs vertical cavity surface-emitting lasers (VCSELs): current challenges and techniques to realize multiple-wavelength laser arrays at 1.55 μm

    NASA Astrophysics Data System (ADS)

    Gobet, Mathilde; Bae, Hopil P.; Sarmiento, Tomas; Harris, James S.

    2008-02-01

    Multiple-wavelength laser arrays at 1.55 μm are key components of wavelength division multiplexing (WDM) systems for increased bandwidth. Vertical cavity surface-emitting lasers (VCSELs) grown on GaAs substrates outperform their InP counterparts in several points. We summarize the current challenges to realize continuous-wave (CW) GaInNAsSb VCSELs on GaAs with 1.55 μm emission wavelength and explain the work in progress to realize CW GaInNAsSb VCSELs. Finally, we detail two techniques to realize GaInNAsSb multiple-wavelength VCSEL arrays at 1.55 μm. The first technique involves the incorporation of a photonic crystal into the upper mirror. Simulation results for GaAs-based VCSEL arrays at 1.55 μm are shown. The second technique uses non-uniform molecular beam epitaxy (MBE). We have successfully demonstrated 1x6 resonant cavity light-emitting diode arrays at 850 nm using this technique, with wavelength spacing of 0.4 nm between devices and present these results.

  5. Capacitance spectroscopy on n-type GaNAs/GaAs embedded quantum structure solar cells

    NASA Astrophysics Data System (ADS)

    Venter, Danielle; Bollmann, Joachim; Elborg, Martin; Botha, J. R.; Venter, André

    2018-04-01

    In this study, both deep level transient spectroscopy (DLTS) and admittance spectroscopy (AS) have been used to study the properties of electrically active deep level centers present in GaNAs/GaAs quantum wells (QWs) embedded in p-i-n solar cells. The structures were grown by molecular beam epitaxy (MBE). In particular, the electrical properties of samples with Si (n-type) doping of the QWs were investigated. DLTS revealed four deep level centers in the material, whereas only three were detected by AS. NextNano++ simulation software was used to model the sample band-diagrams to provide reasoning for the origin of the signals produced by both techniques.

  6. 26-week repeated oral dose toxicity study of UP446, a combination of defined extracts of Scutellaria baicalensis and Acacia catechu, in beagle dogs.

    PubMed

    Yimam, Mesfin; Lee, Young Chul; Jia, Qi

    2016-07-01

    The needs for relatively safe botanical alternatives to relieve symptoms associated to arthritis have continued to grow in parallel with the ageing population. UP446, a standardized bioflavonoid composition from the roots of Scutellaria baicalensis and the heartwoods of Acacia catechu, has been used as over the counter joint care dietary supplements and a prescription medical food. Significant safety data have been documented in rodents and human for this composition. Here we evaluated the potential adverse effects of orally administered UP446 in beagle dogs following a 26-week repeated oral dose toxicity study. UP446 at doses of 250, 500 and 1000 mg/kg/day were administered orally to beagle dogs for 26 weeks. A 4-week recovery group from the high dose (1000 mg/kg) and vehicle treated groups were included. No morbidity or mortality was observed for the duration of the study. No significant differences between groups in body weights, food consumption, ophthalmological examinations, electrocardiograms, urinalysis, hematology, clinical chemistry, organ weights, gross pathology and histopathology were documented. Emesis, loose feces and diarrhea were noted in both genders at the 1000 mg/kg treatment groups. These clinical signs were considered to be reversible as they were not evident in the recovery period. In conclusion, the no-observed-adverse-effect-level (NOAEL) of UP446 was considered to be 500 mg/kg/day both in male and female beagle dogs. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Acacia Changes Microbial Indicators and Increases C and N in Soil Organic Fractions in Intercropped Eucalyptus Plantations.

    PubMed

    Pereira, Arthur P A; Zagatto, Maurício R G; Brandani, Carolina B; Mescolotti, Denise de Lourdes; Cotta, Simone R; Gonçalves, José L M; Cardoso, Elke J B N

    2018-01-01

    Intercropping forest plantations of Eucalyptus with nitrogen-fixing trees can increase soil N inputs and stimulate soil organic matter (OM) cycling. However, microbial indicators and their correlation in specific fractions of soil OM are unclear in the tropical sandy soils. Here, we examined the microbial indicators associated with C and N in the soil resulting from pure and intercropped Eucalyptus grandis and Acacia mangium plantations. We hypothesized that introduction of A. mangium in a Eucalyptus plantation promotes changes in microbial indicators and increases C and N concentrations on labile fractions of the soil OM, when compared to pure eucalyptus plantations. We determined the microbial and enzymatic activity, and the potential for C degradation by the soil microbial community. Additionally, we evaluated soil OM fractions and litter parameters. Soil (0-20 cm) and litter samples were collected at 27 and 39 months after planting from the following treatments: pure E. grandis (E) and A. mangium (A) plantations, pure E. grandis plantations with N fertilizer (E+N) and an E. grandis , and A. mangium intercropped plantations (E+A). The results showed that intercropped plantations (E+A) increase 3, 45, and 70% microbial biomass C as compared to A, E+N, and E, at 27 months after planting. The metabolic quotient ( q CO 2 ) showed a tendency toward stressful values in pure E. grandis plantations and a strong correlation with dehydrogenase activity. A and E+A treatments also exhibited the highest organic fractions (OF) and C and N contents. A canonical redundancy analysis revealed positive correlations between microbial indicators of soil and litter attributes, and a strong effect of C and N variables in differentiating A and E+A from E and E+N treatments. The results suggested that a significant role of A. mangium enhance the dynamics of soil microbial indicators which help in the accumulation of C and N in soil OF in intercropped E. grandis plantations. Our results

  8. Acacia Changes Microbial Indicators and Increases C and N in Soil Organic Fractions in Intercropped Eucalyptus Plantations

    PubMed Central

    Pereira, Arthur P. A.; Zagatto, Maurício R. G.; Brandani, Carolina B.; Mescolotti, Denise de Lourdes; Cotta, Simone R.; Gonçalves, José L. M.; Cardoso, Elke J. B. N.

    2018-01-01

    Intercropping forest plantations of Eucalyptus with nitrogen-fixing trees can increase soil N inputs and stimulate soil organic matter (OM) cycling. However, microbial indicators and their correlation in specific fractions of soil OM are unclear in the tropical sandy soils. Here, we examined the microbial indicators associated with C and N in the soil resulting from pure and intercropped Eucalyptus grandis and Acacia mangium plantations. We hypothesized that introduction of A. mangium in a Eucalyptus plantation promotes changes in microbial indicators and increases C and N concentrations on labile fractions of the soil OM, when compared to pure eucalyptus plantations. We determined the microbial and enzymatic activity, and the potential for C degradation by the soil microbial community. Additionally, we evaluated soil OM fractions and litter parameters. Soil (0–20 cm) and litter samples were collected at 27 and 39 months after planting from the following treatments: pure E. grandis (E) and A. mangium (A) plantations, pure E. grandis plantations with N fertilizer (E+N) and an E. grandis, and A. mangium intercropped plantations (E+A). The results showed that intercropped plantations (E+A) increase 3, 45, and 70% microbial biomass C as compared to A, E+N, and E, at 27 months after planting. The metabolic quotient (qCO2) showed a tendency toward stressful values in pure E. grandis plantations and a strong correlation with dehydrogenase activity. A and E+A treatments also exhibited the highest organic fractions (OF) and C and N contents. A canonical redundancy analysis revealed positive correlations between microbial indicators of soil and litter attributes, and a strong effect of C and N variables in differentiating A and E+A from E and E+N treatments. The results suggested that a significant role of A. mangium enhance the dynamics of soil microbial indicators which help in the accumulation of C and N in soil OF in intercropped E. grandis plantations. Our results are

  9. Dieback of Acacia koa in Hawaii: Ecological and pathological characteristics of affected stands

    USGS Publications Warehouse

    Anderson, R.C.; Gardner, D.E.; Daehler, C.C.; Meinzer, F.C.

    2002-01-01

    Koa (Acacia koa) is an endemic Hawaiian tree that serves as a keystone species in the upper elevation forests of all the main islands. In the Mauna Loa Strip area of Hawaii Volcanoes National Park, mature koa stands are suffering from an unexplained dieback that has increased in severity since it was first noticed approximately 25 years ago. The dieback is often evident in patches, and generally spreads within stands in a radial fashion from a localized infection center. Entire crowns of affected trees become wilted, with foliage gradually progressing from an apparent healthy to a completely chlorotic condition. Although most trees die soon after the onset of symptoms, some trees are able to survive crown death by producing epicormic shoots on the lower portions of the trunk. Previously published studies reported that a vascular wilt fungus (Fusarium oxysporum f. sp. koae) was associated with koa seeds and the rhizosphere of healthy and dieback-affected koa stands. The purpose of this study was to characterize the stand structure, soil conditions, and physiological condition of dieback-affected trees, and to assess the possible role of F. oxysporum f. sp. koae in the current dieback stands. This fungus was isolated from branches of symptomatic koa in dieback-affected stands and roots from healthy and dieback-affected stands. Possible differences in the pathogenicity and virulence of F. oxysporum f. sp. koae isolates obtained from the roots of healthy koa in unaffected stands and those from branches of dieback-affected koa were determined by greenhouse inoculations of koa seedlings. Healthy koa saplings in stands unaffected by dieback were also inoculated to determine if disease symptoms could be induced by inoculation of injured roots in the field. Both branch and root isolates were pathogenic; with the percent mortality of inoculated seedlings ranging from 30 to 60% for all isolates. Disease severity between branch and root isolates was not significantly different

  10. Legume-rhizobium symbiotic promiscuity and effectiveness do not affect plant invasiveness.

    PubMed

    Keet, Jan-Hendrik; Ellis, Allan G; Hui, Cang; Le Roux, Johannes J

    2017-06-01

    The ability to fix atmospheric nitrogen is thought to play an important role in the invasion success of legumes. Interactions between legumes and nitrogen-fixing bacteria (rhizobia) span a continuum of specialization, and promiscuous legumes are thought to have higher chances of forming effective symbioses in novel ranges. Using Australian Acacia species in South Africa, it was hypothesized that widespread and highly invasive species will be more generalist in their rhizobial symbiotic requirements and more effective in fixing atmospheric nitrogen compared with localized and less invasive species. To test these hypotheses, eight localized and 11 widespread acacias were examined using next-generation sequencing data for the nodulation gene, nodC , to compare the identity, species richness, diversity and compositional similarity of rhizobia associated with these acacias. Stable isotope analysis was also used to determine levels of nitrogen obtained from the atmosphere via symbiotic nitrogen fixation. No differences were found in richness, diversity and community composition between localized and widespread acacias. Similarly, widespread and localized acacias did not differ in their ability to fix atmospheric nitrogen. However, for some species by site comparisons, significant differences in δ15N isotopic signatures were found, indicating differential symbiotic effectiveness between these species at specific localities. Overall, the results support recent findings that root nodule rhizobial diversity and community composition do not differ between acacias that vary in their invasiveness. Differential invasiveness of acacias in South Africa is probably linked to attributes such as differences in propagule pressure, reasons for (e.g. forestry vs. ornamental) and extent of, plantings in the country. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  11. MPI, HPF or OpenMP: A Study with the NAS Benchmarks

    NASA Technical Reports Server (NTRS)

    Jin, Hao-Qiang; Frumkin, Michael; Hribar, Michelle; Waheed, Abdul; Yan, Jerry; Saini, Subhash (Technical Monitor)

    1999-01-01

    Porting applications to new high performance parallel and distributed platforms is a challenging task. Writing parallel code by hand is time consuming and costly, but the task can be simplified by high level languages and would even better be automated by parallelizing tools and compilers. The definition of HPF (High Performance Fortran, based on data parallel model) and OpenMP (based on shared memory parallel model) standards has offered great opportunity in this respect. Both provide simple and clear interfaces to language like FORTRAN and simplify many tedious tasks encountered in writing message passing programs. In our study we implemented the parallel versions of the NAS Benchmarks with HPF and OpenMP directives. Comparison of their performance with the MPI implementation and pros and cons of different approaches will be discussed along with experience of using computer-aided tools to help parallelize these benchmarks. Based on the study,potentials of applying some of the techniques to realistic aerospace applications will be presented

  12. MPI, HPF or OpenMP: A Study with the NAS Benchmarks

    NASA Technical Reports Server (NTRS)

    Jin, H.; Frumkin, M.; Hribar, M.; Waheed, A.; Yan, J.; Saini, Subhash (Technical Monitor)

    1999-01-01

    Porting applications to new high performance parallel and distributed platforms is a challenging task. Writing parallel code by hand is time consuming and costly, but this task can be simplified by high level languages and would even better be automated by parallelizing tools and compilers. The definition of HPF (High Performance Fortran, based on data parallel model) and OpenMP (based on shared memory parallel model) standards has offered great opportunity in this respect. Both provide simple and clear interfaces to language like FORTRAN and simplify many tedious tasks encountered in writing message passing programs. In our study, we implemented the parallel versions of the NAS Benchmarks with HPF and OpenMP directives. Comparison of their performance with the MPI implementation and pros and cons of different approaches will be discussed along with experience of using computer-aided tools to help parallelize these benchmarks. Based on the study, potentials of applying some of the techniques to realistic aerospace applications will be presented.

  13. Using a polarizing film in the manufacture of panoramic Stokes polarimeters at the Main Astronomical Observatory of NAS of Ukraine

    NASA Astrophysics Data System (ADS)

    Syniavskyi, I.; Ivanov, Yu.; Vidmachenko, A. P.; Sergeev, A.

    2015-08-01

    The construction of an imaging Stokes-polarimeter in the MAO NAS of Ukraine is proposed. It allows measuring the three components of the Stokes vector simultaneously in large FOV without restrictions on the relative aperture of the system. Moreover, the polarimeter can be converted to a low resolution spectropolarimeter by placement into optical axis of the transparence diffraction grating.

  14. Communications for UAS Integration in the NAS Phase 2 - Satellite Communications and Terrestrial Extension

    NASA Technical Reports Server (NTRS)

    Griner, James H.; Kerczewski, Robert J.

    2017-01-01

    In order to provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System, the command and control communications link connecting the ground-based pilot with the unmanned aircraft must be highly reliable and robust, with national and international standards to enable interoperability and certification. Both line-of-sight (LOS) links using terrestrial-based communications and beyond-line-of-sight (BLOS) links using satellite communications, supported by national and international standards, are required for integrated UAS operations. The National Aeronautics and Space Administration (NASA) has undertaken an extensive technology development and test program in order to provide the required technical data needed to enable C2 standards development. NASAs UAS Integration in the National Airspace System (NAS), or UAS in the NAS Project, included as a major element the Command and Control Communications (C2) Subproject, based at NASAs Glenn Research Center. The successful first phase of the C2 Subproject, completed during 2012-2016, focused primarily on line-of-sight communications. Accomplishments included air-ground channel propagation characterization and modeling; CNPC prototype radio development; CNPC radio flight testing; satellite communications spectrum study and interference analysis; and development of C2 LOS communications standards development. The second phase of the C2 Subproject will focus primarily on beyond-line-of-sight communications, although a follow-on activity for terrestrial LOS communications, known as Terrestrial Extension, is also included. In addition to the terrestrial element, Phase 2 also includes technology development and testing activities for Ka-Band BLOS C2 Satellite Communications; Ku-Band BLOS C2 Satellite Communications; Ku-Band Interference and Propagation; and C-Band Satellite Communications. This paper will provide brief overviews of the C2 Subproject and its Phase I accomplishments

  15. Communications for UAS Integration in the NAS Phase 2 Satellite Communications and Terrestrial Extension

    NASA Technical Reports Server (NTRS)

    Griner, Jim; Kerczewski, Bob

    2017-01-01

    In order to provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System, the command and control communications link connecting the ground-based pilot with the unmanned aircraft must be highly reliable and robust, with national and international standards to enable interoperability and certification. Both line-of-sight (LOS) links using terrestrial-based communications and beyond-line-of-sight (BLOS) links using satellite communications, supported by national and international standards, are required for integrated UAS operations. The National Aeronautics and Space Administration (NASA) has undertaken an extensive technology development and test program in order to provide the required technical data needed to enable C2 standards development. NASAs UAS Integration in the National Airspace System (NAS), or UAS in the NAS Project, included as a major element the Command and Control Communications (C2) Subproject, based at NASAs Glenn Research Center. The successful first phase of the C2 Subproject, completed during 2012-2016, focused primarily on line-of-sight communications. Accomplishments included air-ground channel propagation characterization and modeling; CNPC prototype radio development; CNPC radio flight testing; satellite communications spectrum study and interference analysis; and development of C2 LOS communications standards development. The second phase of the C2 Subproject will focus primarily on beyond-line-of-sight communications, although a follow-on activity for terrestrial LOS communications, known as Terrestrial Extension, is also included. In addition to the terrestrial element, Phase 2 also includes technology development and testing activities for Ka-Band BLOS C2 Satellite Communications; Ku-Band BLOS C2 Satellite Communications; Ku-Band Interference and Propagation; and C-Band Satellite Communications. This paper will provide brief overviews of the C2 Subproject and its Phase I accomplishments

  16. In vitro antibacterial and time-kill assessment of crude methanolic stem bark extract of Acacia mearnsii de wild against bacteria in shigellosis.

    PubMed

    Olajuyigbe, Olufunmiso Olusola; Afolayan, Anthony Jide

    2012-02-21

    Shigellosis is an important cause of worldwide morbidity and mortality among young children and old people for which treatment with antimicrobial agents is limited. Hence, the need for curative potentials obtainable from medicinal plants becomes inevitable. This study was carried out to assess the antibacterial potentials of crude methanolic extract of the stem bark of Acacia mearnsii against some selected bacteria of clinical importance in shigellosis. The bacteria were inhibited by the extract to produce concentration dependent inhibition zones. The extract exhibited a varied degree of antibacterial activity against all the tested isolates. The MIC values for Gram negative (0.0391-0.3125) mg/mL and those of Gram positive bacteria (0.0781-0.625) mg/mL indicated that the Gram negative bacteria were more inhibited by the extract than the Gram positive bacteria. Average log reduction in viable cell count in time-kill assay ranged between -2.456 Log₁₀ to 2.230 Log₁₀ cfu/mL after 4 h of interaction, and between -2.921 Log₁₀ and 1.447 Log₁₀ cfu/mL after 8 h interaction in 1× MIC and 2× MIC of the extract. The study provided scientific justification for the use of the crude methanolic extract from the stem bark of A. mearnsii in shigellosis. The degree of the antibacterial activity indicated that the crude extract is a potential source of bioactive compounds that could be useful for the development of new antimicrobial agents capable of decreasing the burden of drug resistance and cost of management of diseases of clinical and public health importance in South Africa.

  17. Mechanistic Insight into Salt Tolerance of Acacia auriculiformis: The Importance of Ion Selectivity, Osmoprotection, Tissue Tolerance, and Na+ Exclusion

    PubMed Central

    Rahman, Md. M.; Rahman, Md. A.; Miah, Md. G.; Saha, Satya R.; Karim, M. A.; Mostofa, Mohammad G.

    2017-01-01

    Salinity, one of the major environmental constraints, threatens soil health and consequently agricultural productivity worldwide. Acacia auriculiformis, being a halophyte, offers diverse benefits against soil salinity; however, the defense mechanisms underlying salt-tolerant capacity in A. auriculiformis are still elusive. In this study, we aimed to elucidate mechanisms regulating the adaptability of the multi-purpose perennial species A. auriculiformis to salt stress. The growth, ion homeostasis, osmoprotection, tissue tolerance and Na+ exclusion, and anatomical adjustments of A. auriculiformis grown in varied doses of seawater for 90 and 150 days were assessed. Results showed that diluted seawater caused notable reductions in the level of growth-related parameters, relative water content, stomatal conductance, photosynthetic pigments, proteins, and carbohydrates in dose- and time-dependent manners. However, the percent reduction of these parameters did not exceed 50% of those of control plants. Na+ contents in phyllodes and roots increased with increasing levels of salinity, whereas K+ contents and K+/Na+ ratio decreased significantly in comparison with control plants. A. auriculiformis retained more Na+ in the roots and maintained higher levels of K+, Ca2+ and Mg2+, and K+/Na+ ratio in phyllodes than roots through ion selective capacity. The contents of proline, total free amino acids, total sugars and reducing sugars significantly accumulated together with the levels of malondialdehyde and electrolyte leakage in the phyllodes, particularly at day 150th of salt treatment. Anatomical investigations revealed various anatomical changes in the tissues of phyllodes, stems and roots by salt stress, such as increase in the size of spongy parenchyma of phyllodes, endodermal thickness of stems and roots, and the diameter of root vascular bundle, relative to control counterparts. Furthermore, the estimated values for Na+ exclusion and tissue tolerance index suggested that

  18. Cation and anion leaching and growth of Acacia saligna in bauxite residue sand amended with residue mud, poultry manure and phosphogypsum.

    PubMed

    Jones, B E H; Haynes, R J; Phillips, I R

    2012-03-01

    To examine (1) the effect of organic (poultry manure) and inorganic (residue mud and phosphogypsum) amendments on nutrient leaching losses from residue sand and (2) whether amendments improve the growth of plants in residue sand. Leaching columns were established using residue sand. The phosphogypsum-treated surface layer (0-15 cm) was amended with poultry manure and/or bauxite residue mud and the subsurface layer (15-45 cm) was either left untreated or amended with phosphogypsum. Much of the Na⁺, K⁺, Cl⁻ and SO₄²⁻ was lost during the first four leachings. Additions of phosphogypsum to both surface and subsurface layers resulted in partial neutralization of soluble alkalinity. Mean pH of leachates ranged from 8.0 to 8.4, the major cation leached was Na⁺ and the major balancing anion was SO₄²⁻ . Where gypsum was not applied to the subsurface, mean pH of leachates was 10.0-10.9, the main cation leached was still Na⁺ and the main balancing anions were a combination of SO₄²⁻ and HCO₃⁻/CO₃²⁻. At the end of the experiment, concentrations of exchangeable Na⁺ in the subsurface layers were similar regardless of whether gypsum had been applied to that layer or not. Yields of Acacia saligna were promoted by additions of poultry manure to the surface layer but unaffected by gypsum incorporation into the subsurface layer. Lack of reaction of phosphogypsum with the subsurface layer is unlikely to be a major factor limiting revegetation of residue sand since in the absence of phosphogypsum the excess Na⁺ leaches with the residual alkalinity (HCO₃⁻/CO₃²⁻) rather than SO₄²⁻.

  19. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project - Gen-4 and Gen-5 Radio Plans

    NASA Technical Reports Server (NTRS)

    Griner, James H.

    2014-01-01

    NASA's UAS Integration in the NAS project, has partnered with Rockwell Collins to develop a concept Control and Non-Payload Communication (CNPC) system prototype radio, operating on recently allocated UAS frequency spectrum bands. This prototype radio is being used to validate initial proposed performance requirements for UAS control communications. This presentation will give an overview of the current plans for the prototype radio development.

  20. UAS Integration into the NAS: Detect and Avoid Display Evaluations in Support of SC-228 MOPS Development

    NASA Technical Reports Server (NTRS)

    Fern, Lisa; Rorie, Conrad; Shively, Jay

    2015-01-01

    This presentation provides an overview of the work the Human Systems Integration (HSI) sub-project has done on detect and avoid (DAA) displays while working on the UAS Integration into the NAS project. Much of the work has been used to support the ongoing development of minimum operational performance standards (MOPS) for UAS by RTCA Special Committee 228. The design and results of three different human-in-the-loop simulations are discussed, with particular emphasis on the role of the UAS pilot in the Self Separation Timeline.

  1. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project: Terminal Operations HITL 1: Primary Results

    NASA Technical Reports Server (NTRS)

    Rorie, Conrad; Fern, Lisa; Monk, Kevin; Roberts, Zach; Brandt, Summer

    2017-01-01

    This presentation covers the primary results of the Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project Terminal Operations Foundational Human-in-the-Loop (HITL) simulation. The study tasked 16 pilots (half with manned piloting experience, and the other half with unmanned piloting experience) with maintaining "well clear" from other traffic while performing three different types of approaches into the Santa Rosa airport. A detect and avoid (DAA) system was provided to pilots to assist their ability to manage separation. The DAA system used in this test conformed to the criteria defined by RTCA Special Committee 228 (SC-228) in their Phase 1 Minimum Operational Performance Standards (MOPS) for UAS intending to operate in the NAS. The Phase 1 system was not designed to account for terminal operations, focusing instead on en route operations. To account for this, three different alerting and guidance configurations were presently tested in order to determine their effect on pilots operating the system in the terminal area. Results indicated that pilots with the alerting and guidance condition that provided the least amount of assistance (fewer alert levels and guidance types) experienced slightly increased pilot response times and rates of losses of separation. Additional data is presented on the effects of approach type and descriptive data on pilot maneuver preferences and ATC interoperability.

  2. The CSM testbed software system: A development environment for structural analysis methods on the NAS CRAY-2

    NASA Technical Reports Server (NTRS)

    Gillian, Ronnie E.; Lotts, Christine G.

    1988-01-01

    The Computational Structural Mechanics (CSM) Activity at Langley Research Center is developing methods for structural analysis on modern computers. To facilitate that research effort, an applications development environment has been constructed to insulate the researcher from the many computer operating systems of a widely distributed computer network. The CSM Testbed development system was ported to the Numerical Aerodynamic Simulator (NAS) Cray-2, at the Ames Research Center, to provide a high end computational capability. This paper describes the implementation experiences, the resulting capability, and the future directions for the Testbed on supercomputers.

  3. UAS in the NAS Project: Large-Scale Communication Architecture Simulations with NASA GRC Gen5 Radio Model

    NASA Technical Reports Server (NTRS)

    Kubat, Gregory

    2016-01-01

    This report provides a description and performance characterization of the large-scale, Relay architecture, UAS communications simulation capability developed for the NASA GRC, UAS in the NAS Project. The system uses a validated model of the GRC Gen5 CNPC, Flight-Test Radio model. Contained in the report is a description of the simulation system and its model components, recent changes made to the system to improve performance, descriptions and objectives of sample simulations used for test and verification, and a sampling and observations of results and performance data.

  4. DAIDALUS Observations From UAS Integration in the NAS Project Flight Test 4

    NASA Technical Reports Server (NTRS)

    Vincent, Michael J.; Tsakpinis, Dimitrios

    2016-01-01

    In order to validate the Unmanned Aerial System (UAS) Detect-and-Avoid (DAA) solution proposed by standards body RTCA Inc., the National Aeronautics and Space Administration (NASA) UAS Integration in the NAS project, alongside industry members General Atomics and Honeywell, conducted the fourth flight test in a series at Armstrong Flight Research Center in Edwards, California. Flight Test 4 (FT4) investigated problems of interoperability with the TCAS collision avoidance system with a DAA system as well as problems associated with sensor uncertainty. A series of scripted flight encounters between the NASA Ikhana UAS and various "intruder" aircraft were flown while alerting and guidance from the DAA algorithm were recorded to investigate the timeliness of the alerts and correctness of the guidance triggered by the DAA system. The results found that alerts were triggered in a timely manner in most instances. Cases where the alerting and guidance was incorrect were investigated further.

  5. Humidity-regulated dormancy onset in the Fabaceae: a conceptual model and its ecological implications for the Australian wattle Acacia saligna

    PubMed Central

    Tozer, Mark G.; Ooi, Mark K. J.

    2014-01-01

    Background and aims Seed dormancy enhances fitness by preventing seeds from germinating when the probability of seedling survival and recruitment is low. The onset of physical dormancy is sensitive to humidity during ripening; however, the implications of this mechanism for seed bank dynamics have not been quantified. This study proposes a model that describes how humidity-regulated dormancy onset may control the accumulation of a dormant seed bank, and seed experiments are conducted to calibrate the model for an Australian Fabaceae, Acacia saligna. The model is used to investigate the impact of climate on seed dormancy and to forecast the ecological implications of human-induced climate change. Methods The relationship between relative humidity and dormancy onset was quantified under laboratory conditions by exposing freshly matured non-dormant seeds to constant humidity levels for fixed durations. The model was field-calibrated by measuring the response of seeds exposed to naturally fluctuating humidity. The model was applied to 3-hourly records of humidity spanning the period 1972–2007 in order to estimate both temporal variability in dormancy and spatial variability attributable to climatic differences among populations. Climate change models were used to project future changes in dormancy onset. Key Results A sigmoidal relationship exists between dormancy and humidity under both laboratory and field conditions. Seeds ripened under field conditions became dormant following very short exposure to low humidity (<20 %). Prolonged exposure at higher humidity did not increase dormancy significantly. It is predicted that populations growing in a temperate climate produce 33–55 % fewer dormant seeds than those in a Mediterranean climate; however, dormancy in temperate populations is predicted to increase as a result of climate change. Conclusions Humidity-regulated dormancy onset may explain observed variation in physical dormancy. The model offers a systematic

  6. p- to n-type conductivity transition in 1.0 eV GaInNAs solar cells controlled by the V/III ratio

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

    Langer, Fabian, E-mail: fabian.langer@physik.uni-wuerzburg.de; Perl, Svenja; Kamp, Martin

    2015-02-09

    In this work, we report a p- to n-type conductivity transition of GaInNAs (1.0 eV bandgap) layers in p-i-n dilute nitride solar cells continuously controlled by the V/III ratio during growth. Near the transition region, we were able to produce GaInNAs layers with very low effective electrically active doping concentrations resulting in wide depleted areas. We obtained internal quantum efficiencies (IQEs) up to 85% at 0.2 eV above the bandgap. However, the high IQE comes along with an increased dark current density resulting in a decreased open circuit voltage of about 0.2 V. This indicates the formation of non-radiant defect centers related tomore » the p-type to n-type transition. Rapid-thermal annealing of the solar cells on the one hand helps to anneal some of these defects but on the other hand increases the effective doping concentrations.« less

  7. Performance Comparison of HPF and MPI Based NAS Parallel Benchmarks

    NASA Technical Reports Server (NTRS)

    Saini, Subhash

    1997-01-01

    Compilers supporting High Performance Form (HPF) features first appeared in late 1994 and early 1995 from Applied Parallel Research (APR), Digital Equipment Corporation, and The Portland Group (PGI). IBM introduced an HPF compiler for the IBM RS/6000 SP2 in April of 1996. Over the past two years, these implementations have shown steady improvement in terms of both features and performance. The performance of various hardware/ programming model (HPF and MPI) combinations will be compared, based on latest NAS Parallel Benchmark results, thus providing a cross-machine and cross-model comparison. Specifically, HPF based NPB results will be compared with MPI based NPB results to provide perspective on performance currently obtainable using HPF versus MPI or versus hand-tuned implementations such as those supplied by the hardware vendors. In addition, we would also present NPB, (Version 1.0) performance results for the following systems: DEC Alpha Server 8400 5/440, Fujitsu CAPP Series (VX, VPP300, and VPP700), HP/Convex Exemplar SPP2000, IBM RS/6000 SP P2SC node (120 MHz), NEC SX-4/32, SGI/CRAY T3E, and SGI Origin2000. We would also present sustained performance per dollar for Class B LU, SP and BT benchmarks.

  8. A Programming Model Performance Study Using the NAS Parallel Benchmarks

    DOE PAGES

    Shan, Hongzhang; Blagojević, Filip; Min, Seung-Jai; ...

    2010-01-01

    Harnessing the power of multicore platforms is challenging due to the additional levels of parallelism present. In this paper we use the NAS Parallel Benchmarks to study three programming models, MPI, OpenMP and PGAS to understand their performance and memory usage characteristics on current multicore architectures. To understand these characteristics we use the Integrated Performance Monitoring tool and other ways to measure communication versus computation time, as well as the fraction of the run time spent in OpenMP. The benchmarks are run on two different Cray XT5 systems and an Infiniband cluster. Our results show that in general the threemore » programming models exhibit very similar performance characteristics. In a few cases, OpenMP is significantly faster because it explicitly avoids communication. For these particular cases, we were able to re-write the UPC versions and achieve equal performance to OpenMP. Using OpenMP was also the most advantageous in terms of memory usage. Also we compare performance differences between the two Cray systems, which have quad-core and hex-core processors. We show that at scale the performance is almost always slower on the hex-core system because of increased contention for network resources.« less

  9. Acacia nilotica leave extract and glyburide: comparison of fasting blood glucose, serum insulin, beta-thromboglubulin levels and platelet aggregation in streptozotocin induced diabetic rats.

    PubMed

    Asad, Munnaza; Munir, Tahir Ahmad; Afzal, Nasir

    2011-03-01

    To evaluate the hypoglycaemic and anti-platelet aggregation effect of aqueous methanol extract of Acacia Nilotica (AN) leaves compared with glyburide on streptozotocin induced diabetic rats. Diabetes mellitus was induced in 90 out of 120 albino rats by administering 50 mg/kg body weight (b.w) streptozotocin and was confirmed by measuring fasting blood glucose level >200 mg/dL on 4th post-induction day. The rats were equally divided into 4 groups, A (normal control), B (diabetic control), C (diabetic rats treated with AN extract) and group D (diabetic rats treated with glyburide). The rats of group C and D were given 300 mg/kg b.w AN extract and 900 microgm/kg b.w glyburide respectively for 3 weeks. Blood glucose was measured by glucometer, platelet aggregation by Dia-Med method and insulin and beta-thromboglobulin by ELISA technique. A significant increase (p<0.05) in fasting blood glucose, beta-thromboglobulin and platelet aggregation and a significant decrease (p<0.05) in insulin levels was observed in streptozotocin induced diabetic rats than the normal controls. The rats treated with AN extract and glyburide showed a significant decrease (p<0.05) in fasting blood glucose and increase (p<0.05) in insulin levels than the diabetic control rats. However, the levels in both the treatment groups remained significantly different than the normal controls. A significant decrease (p<0.05) in beta-thromboglobulin levels was seen in diabetic rats treated with glyburide than the diabetic control rats and diabetic rats treated with AN extract. AN leaves extract result into hypoglycaemic and anti-platelet aggregation activity in diabetic rats as that of glyburide.

  10. Weather Requirements and Procedures for Step 1: High Altitude Long Endurance (HALE) Unmanned Aircraft System (UAS) Flight Operations in the National Air Space (NAS)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This cover sheet is for version 2 of the weather requirements document along with Appendix A. The purpose of the requirements document was to identify and to list the weather functional requirements needed to achieve the Access 5 vision of "operating High Altitude, Long Endurance (HALE) Unmanned Aircraft Systems (UAS) routinely, safely, and reliably in the National Airspace System (NAS) for Step 1." A discussion of the Federal Aviation Administration (FAA) references and related policies, procedures, and standards is provided as basis for the recommendations supported within this document. Additional procedures and reference documentation related to weather functional requirements is also provided for background. The functional requirements and related information are to be proposed to the FAA and various standards organizations for consideration and approval. The appendix was designed to show that sources of flight weather information are readily available to UAS pilots conducting missions in the NAS. All weather information for this presentation was obtained from the public internet.

  11. Growth, biomass production and photosynthesis of Cenchrus ciliaris L. under Acacia tortilis (Forssk.) Hayne based silvopastoral systems in semi arid tropics.

    PubMed

    Mishra, A K; Tiwari, H S; Bhatt, R K

    2010-11-01

    The growth, biomass production and photosynthesis of Cenchrus ciliaris was studied under the canopies of 17 yr old Acacia tortilis trees in semi arid tropical environment. On an average the full grown canopy of A. tortilis at the spacing of 4 x 4 m allowed 55% of total Photosynthetically Active Radiation (PAR) which in turn increased Relative Humidity (RH) and reduced under canopy temperature to -1.75 degrees C over the open air temperature. C. ciliaris attained higher height under the shade of A. tortilis. The tiller production and leaf area index decreased marginally under the shade of tree canopies as compared to the open grown grasses. C. ciliaris accumulated higher chlorophyll a and b under the shade of tree canopies indicating its shade adaptation potential. The assimilatory functions such as rate of photosynthesis, transpiration, stomatal conductance, photosynthetic water use efficiency (PN/TR) and carboxylation efficiency (PN/CINT) decreased under the tree canopies due to low availability of PAR. The total biomass production in term of fresh and dry weight decreased under the tree canopies. On average of 2 yr C. ciliaris had produced 12.78 t ha(-1) green and 3.72 -t ha(-1) dry biomass under the tree canopies of A. tortilis. The dry matter yield reduced to 38% under the tree canopies over the open grown grasses. The A. tortilis + C. ciliaris maintained higher soil moisture, organic carbon content and available N P K for sustainable biomass production for the longer period. The higher accumulation of crude protein, starch, sugar and nitrogen in leaves and stem of C. ciliaris indicates that this grass species also maintained its quality under A. tortilis based silvopastoral system. The photosynthesis and dry matter accumulation are closely associated with available PAR indicating that for sustainable production of this grass species in the silvopasture systems for longer period about 55% or more PAR is required.

  12. Physicochemical, functional and rheological investigation of Soymida febrifuga exudate gum.

    PubMed

    Bhushette, Pravin R; Annapure, Uday S

    2018-05-01

    Acacia gum is a well-known and most used exudate gum. High solubility with low viscosity is one of the best property of this gum. Many studies were conducted to find out a substitute for acacia gum but very few gum had shown properties as good as acacia gum. The exudates collected from Soymida febrifuga also shows high solubility with low viscosity as acacia gum. Purified Soymida febrifuga gum (SFG) was characterised for physicochemical, functional, rheological and thermal properties. The FTIR spectra of SFG revealed a typical trend of polysaccharides. The monosaccharide composition of the gums indicated the presence arabinose, galactose, and ribose. Element composition of SFG shows resemblance with AG. However, the molecular weight of SFG is less than the AG. The rheological outcome was derived from flow curve measurements of gum at different concentrations and temperatures. Alikeness was observed in Viscosity profile of both the gums. SFG shows semblance with AG and can be use in food and pharmaceutical industry. Copyright © 2018. Published by Elsevier B.V.

  13. UAS Integration into the NAS: Unmanned Aircraft System (UAS) Delegation of Separation

    NASA Technical Reports Server (NTRS)

    Fern, Lisa Carolynn; Kenny, Caitlin Ailis

    2012-01-01

    FAA Modernization and Reform Act of 2012 mandates UAS integration in the NAS by 2015. Operators must be able to safely maneuver UAS to maintain separation and collision avoidance. Delegated Separation is defined as the transfer of responsibility for maintaining separation between aircraft or vehicles from the air navigation service provider to the relevant flight operator, and will likely begin in sparsely trafficked areas before moving to more heavily populated airspace. As UAS operate primarily in areas with lower traffic density and perform maneuvers routinely that are currently managed through special handling, they have the advantage of becoming an early adopter of delegated separation. This experiment will examine if UAS are capable of performing delegated separation in 5 nm horizontal and 1000 ft vertical distances under two delegation conditions. In Extended Delegation, ATC are in charge of identifying problems and delegating to pilot identification and implementation of the solution and monitoring. In Full Delegation, the pilots are responsible for all tasks related to separation assurance: identification of problems and solutions, implementation and monitoring.

  14. Local ecological knowledge concerning the invasion of Amerindian lands in the northern Brazilian Amazon by Acacia mangium (Willd.).

    PubMed

    Souza, Arlene Oliveira; Chaves, Maria do Perpétuo Socorro Rodrigues; Barbosa, Reinaldo Imbrozio; Clement, Charles Roland

    2018-05-03

    Invasive plants can impact biodiversity as well as the lives of native human populations. Natural ecosystems represent sources of natural resources essential for the subsistence and socio-cultural continuity of these social groups. Approximately 30,000 ha of Acacia mangium were planted for commercial purposes in savanna areas surrounding indigenous lands in Roraima State, Brazil, at the end of the 1990s. We examined the local ecological knowledge of indigenous Wapichana and Macuxi Amerindians, members of the Arawak and Carib linguistic families, respectively, concerning A. mangium Willdenow (Fabaceae) in a savanna ecosystem ("Lavrado") to attempt to understand its propagation beyond the limits of the commercial plantations and contribute to mitigating its impacts on socio-ecological systems. The present study was undertaken in the Moskow, São Domingos, and Malacacheta communities in the Moskow and Malacacheta Indigenous Lands (ILs) in the Serra da Lua region of Roraima State, in the northern Brazilian Amazon region. Interviews were conducted with a total of 94 indigenous individuals of both sexes, with ages between 18 and 76, and low levels of formal schooling, with an average time of permanence in the area of 21 years; some still spoke only their native languages. The interviews focused on their ecological knowledge of the invasive, non-native A. mangium and their uses of it. The informants affirmed that A. mangium negatively impacted the local fauna and flora, making their subsistence more difficult and altering their daily routines. Among the problems cited were alterations of water quality (71.3%), negative impacts on crops (60.6%), negative impacts on the equilibrium of the local fauna (52.1%), increased farm labor requirements (41.5%), and restriction of access to indigenous lands (23.4%). There were no significant differences between the opinions of men and women, nor between community leaders and nonleaders. Most of the interviewees (89%) felt that A

  15. NAS Parallel Benchmark. Results 11-96: Performance Comparison of HPF and MPI Based NAS Parallel Benchmarks. 1.0

    NASA Technical Reports Server (NTRS)

    Saini, Subash; Bailey, David; Chancellor, Marisa K. (Technical Monitor)

    1997-01-01

    High Performance Fortran (HPF), the high-level language for parallel Fortran programming, is based on Fortran 90. HALF was defined by an informal standards committee known as the High Performance Fortran Forum (HPFF) in 1993, and modeled on TMC's CM Fortran language. Several HPF features have since been incorporated into the draft ANSI/ISO Fortran 95, the next formal revision of the Fortran standard. HPF allows users to write a single parallel program that can execute on a serial machine, a shared-memory parallel machine, or a distributed-memory parallel machine. HPF eliminates the complex, error-prone task of explicitly specifying how, where, and when to pass messages between processors on distributed-memory machines, or when to synchronize processors on shared-memory machines. HPF is designed in a way that allows the programmer to code an application at a high level, and then selectively optimize portions of the code by dropping into message-passing or calling tuned library routines as 'extrinsics'. Compilers supporting High Performance Fortran features first appeared in late 1994 and early 1995 from Applied Parallel Research (APR) Digital Equipment Corporation, and The Portland Group (PGI). IBM introduced an HPF compiler for the IBM RS/6000 SP/2 in April of 1996. Over the past two years, these implementations have shown steady improvement in terms of both features and performance. The performance of various hardware/ programming model (HPF and MPI (message passing interface)) combinations will be compared, based on latest NAS (NASA Advanced Supercomputing) Parallel Benchmark (NPB) results, thus providing a cross-machine and cross-model comparison. Specifically, HPF based NPB results will be compared with MPI based NPB results to provide perspective on performance currently obtainable using HPF versus MPI or versus hand-tuned implementations such as those supplied by the hardware vendors. In addition we would also present NPB (Version 1.0) performance results for

  16. An amphetamine isomer whose efficacy and safety in humans has never been studied, β-methylphenylethylamine (BMPEA), is found in multiple dietary supplements.

    PubMed

    Cohen, Pieter A; Bloszies, Clayton; Yee, Caleb; Gerona, Roy

    2016-01-01

    The amphetamine isomer β-methylphenylethylamine (BMPEA) was first synthesized in the early 1930s, but its efficacy and safety in humans has not been studied. Recently, the United States Food and Drug Administration (FDA) detected BMPEA in dietary supplements labelled as containing Acacia rigidula. Over a year after the FDA reported its findings, we analyzed Acacia rigidula dietary supplements to determine if BMPEA had been removed. Supplements were analyzed using liquid chromatography-quadrupole time-of-flight mass spectrometry. Diluted methanolic extract from each supplement was run three times and each data set obtained was analyzed using Agilent MassHunter Qualitative Analysis. The presence of BMPEA was confirmed by accurate mass, retention time and mass spectra match against a reference standard. Quantification of BMPEA was determined using an eight-point calibration curve of spiked standard to a matrix blank. Twenty-one brands of Acacia rigidula supplements were analyzed. More than half (11/21; 52.4%) of the Acacia rigidula supplement brands contained BMPEA. The stimulant was present at quantities such that consumers following recommended maximum daily servings would consume a maximum of 93.7 mg of BMPEA per day. Consumers of Acacia rigidula supplements may be exposed to pharmacological dosages of an amphetamine isomer that lacks evidence of safety in humans. The FDA should immediately warn consumers about BMPEA and take aggressive enforcement action to eliminate BMPEA in dietary supplements. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  17. Binding S0.6 Se0.4 in 1D Carbon Nanofiber with CS Bonding for High-Performance Flexible Li-S Batteries and Na-S Batteries.

    PubMed

    Yao, Yu; Zeng, Linchao; Hu, Shuhe; Jiang, Yu; Yuan, Beibei; Yu, Yan

    2017-05-01

    A one-step synthesis procedure is developed to prepare flexible S 0.6 Se 0.4 @carbon nanofibers (CNFs) electrode by coheating S 0.6 Se 0.4 powder with electrospun polyacrylonitrile nanofiber papers at 600 °C. The obtained S 0.6 Se 0.4 @CNFs film can be used as cathode material for high-performance Li-S batteries and room temperature (RT) Na-S batteries directly. The superior lithium/sodium storage performance derives from its rational structure design, such as the chemical bonding between Se and S, the chemical bonding between S 0.6 Se 0.4 and CNFs matrix, and the 3D CNFs network. This easy one-step synthesis procedure provides a feasible route to prepare electrode materials for high-performance Li-S and RT Na-S batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Humidity-regulated dormancy onset in the Fabaceae: a conceptual model and its ecological implications for the Australian wattle Acacia saligna.

    PubMed

    Tozer, Mark G; Ooi, Mark K J

    2014-09-01

    Seed dormancy enhances fitness by preventing seeds from germinating when the probability of seedling survival and recruitment is low. The onset of physical dormancy is sensitive to humidity during ripening; however, the implications of this mechanism for seed bank dynamics have not been quantified. This study proposes a model that describes how humidity-regulated dormancy onset may control the accumulation of a dormant seed bank, and seed experiments are conducted to calibrate the model for an Australian Fabaceae, Acacia saligna. The model is used to investigate the impact of climate on seed dormancy and to forecast the ecological implications of human-induced climate change. The relationship between relative humidity and dormancy onset was quantified under laboratory conditions by exposing freshly matured non-dormant seeds to constant humidity levels for fixed durations. The model was field-calibrated by measuring the response of seeds exposed to naturally fluctuating humidity. The model was applied to 3-hourly records of humidity spanning the period 1972-2007 in order to estimate both temporal variability in dormancy and spatial variability attributable to climatic differences among populations. Climate change models were used to project future changes in dormancy onset. A sigmoidal relationship exists between dormancy and humidity under both laboratory and field conditions. Seeds ripened under field conditions became dormant following very short exposure to low humidity (<20 %). Prolonged exposure at higher humidity did not increase dormancy significantly. It is predicted that populations growing in a temperate climate produce 33-55 % fewer dormant seeds than those in a Mediterranean climate; however, dormancy in temperate populations is predicted to increase as a result of climate change. Humidity-regulated dormancy onset may explain observed variation in physical dormancy. The model offers a systematic approach to modelling this variation in population studies

  19. [Seasonal differences in the leaf hydraulic conductance of mature Acacia mangium in response to its leaf water use and photosynthesis].

    PubMed

    Zhao, Ping; Sun, Gu-Chou; Ni, Guang-Yan; Zeng, Xiao-Ping

    2013-01-01

    In this study, measurements were made on the leaf water potential (psi1), stomatal conductance (g(s)), transpiration rate, leaf area index, and sapwood area of mature Acacia mangium, aimed to understand the relationships of the leaf hydraulic conductance (K1) with the leaf water use and photosynthetic characteristics of the A. mangium in wet season (May) and dry season (November). The ratio of sapwood area to leaf area (A(sp)/A(cl)) of the larger trees with an average height of 20 m and a diameter at breast height (DBH) of 0.26 m was 8.5% higher than that of the smaller trees with an average height of 14.5 m and a DBH of 0.19 m, suggesting that the larger trees had a higher water flux in their leaf xylem, which facilitated the water use of canopy leaf. The analysis on the vulnerability curve of the xylem showed that when the K1 decreased by 50%, the psi1 in wet season and dry season was -1.41 and -1.55 MPa, respectively, and the vulnerability of the xylem cavitation was higher in dry season than in wet season. The K1 peak value in wet season and dry season was 5.5 and 4.5 mmol x m(-2) x s(-1) x MPa(-1), and the maximum transpiration rate (T(r max)) was 3.6 and 1.8 mmol x m(-2) x s(-1), respectively. Both the K1 and T(r max), were obviously higher in wet season than in dry season. Within a day, the K1 and T(r), fluctuated many times, reflecting the reciprocated cycle of the xylem cavitation and refilling. The leaf stomatal closure occurred when the K1 declined over 50% or the psi1 reached -1.6 MPa. The g(s) would be maintained at a high level till the K1 declined over 50%. The correlation between the hydraulic conductance and photosynthetic rate was more significant in dry season than in wet season. The loss of leaf hydraulic conductance induced by seasonal change could be the causes of the decrease of T(r) and CO2 gas exchange.

  20. In vivo antimicrobial activity of silver nanoparticles produced via a green chemistry synthesis using Acacia rigidula as a reducing and capping agent.

    PubMed

    Escárcega-González, Carlos Enrique; Garza-Cervantes, J A; Vázquez-Rodríguez, A; Montelongo-Peralta, Liliana Zulem; Treviño-González, M T; Díaz Barriga Castro, E; Saucedo-Salazar, E M; Chávez Morales, R M; Regalado Soto, D I; Treviño González, F M; Carrazco Rosales, J L; Cruz, Rocío Villalobos; Morones-Ramírez, José Rubén

    2018-01-01

    One of the main issues in the medical field and clinical practice is the development of novel and effective treatments against infections caused by antibiotic-resistant bacteria. One avenue that has been approached to develop effective antimicrobials is the use of silver nanoparticles (Ag-NPs), since they have been found to exhibit an efficient and wide spectrum of antimicrobial properties. Among the main drawbacks of using Ag-NPs are their potential cytotoxicity against eukaryotic cells and the latent environmental toxicity of their synthesis methods. Therefore, diverse green synthesis methods, which involve the use of environmentally friendly plant extracts as reductive and capping agents, have become attractive to synthesize Ag-NPs that exhibit antimicrobial effects against resistant bacteria at concentrations below toxicity thresholds for eukaryotic cells. In this study, we report a green one-pot synthesis method that uses Acacia rigidula extract as a reducing and capping agent, to produce Ag-NPs with applications as therapeutic agents to treat infections in vivo. The Ag-NPs were characterized using transmission electron microscopy (TEM), high-resolution TEM, selected area electron diffraction, energy-dispersive spectroscopy, ultraviolet-visible, and Fourier transform infrared. We show that Ag-NPs are spherical with a narrow size distribution. The Ag-NPs show antimicrobial activities in vitro against Gram-negative ( Escherichia coli , Pseudomonas aeruginosa , and a clinical multidrug-resistant strain of P. aeruginosa ) and Gram-positive ( Bacillus subtilis ) bacteria. Moreover, antimicrobial effects of the Ag-NPs, against a resistant P. aeruginosa clinical strain, were tested in a murine skin infection model. The results demonstrate that the Ag-NPs reported in this work are capable of eradicating pathogenic resistant bacteria in an infection in vivo. In addition, skin, liver, and kidney damage profiles were monitored in the murine infection model, and the

  1. In vivo antimicrobial activity of silver nanoparticles produced via a green chemistry synthesis using Acacia rigidula as a reducing and capping agent

    PubMed Central

    Escárcega-González, Carlos Enrique; Garza-Cervantes, JA; Vázquez-Rodríguez, A; Montelongo-Peralta, Liliana Zulem; Treviño-González, MT; Díaz Barriga Castro, E; Saucedo-Salazar, EM; Chávez Morales, RM; Regalado Soto, DI; Treviño González, FM; Carrazco Rosales, JL; Cruz, Rocío Villalobos; Morones-Ramírez, José Rubén

    2018-01-01

    Introduction One of the main issues in the medical field and clinical practice is the development of novel and effective treatments against infections caused by antibiotic-resistant bacteria. One avenue that has been approached to develop effective antimicrobials is the use of silver nanoparticles (Ag-NPs), since they have been found to exhibit an efficient and wide spectrum of antimicrobial properties. Among the main drawbacks of using Ag-NPs are their potential cytotoxicity against eukaryotic cells and the latent environmental toxicity of their synthesis methods. Therefore, diverse green synthesis methods, which involve the use of environmentally friendly plant extracts as reductive and capping agents, have become attractive to synthesize Ag-NPs that exhibit antimicrobial effects against resistant bacteria at concentrations below toxicity thresholds for eukaryotic cells. Purpose In this study, we report a green one-pot synthesis method that uses Acacia rigidula extract as a reducing and capping agent, to produce Ag-NPs with applications as therapeutic agents to treat infections in vivo. Materials and methods The Ag-NPs were characterized using transmission electron microscopy (TEM), high-resolution TEM, selected area electron diffraction, energy-dispersive spectroscopy, ultraviolet–visible, and Fourier transform infrared. Results We show that Ag-NPs are spherical with a narrow size distribution. The Ag-NPs show antimicrobial activities in vitro against Gram-negative (Escherichia coli, Pseudomonas aeruginosa, and a clinical multidrug-resistant strain of P. aeruginosa) and Gram-positive (Bacillus subtilis) bacteria. Moreover, antimicrobial effects of the Ag-NPs, against a resistant P. aeruginosa clinical strain, were tested in a murine skin infection model. The results demonstrate that the Ag-NPs reported in this work are capable of eradicating pathogenic resistant bacteria in an infection in vivo. In addition, skin, liver, and kidney damage profiles were

  2. Development of computer program NAS3D using Vector processing for geometric nonlinear analysis of structures

    NASA Technical Reports Server (NTRS)

    Mangalgiri, P. D.; Prabhakaran, R.

    1986-01-01

    An algorithm for vectorized computation of stiffness matrices of an 8 noded isoparametric hexahedron element for geometric nonlinear analysis was developed. This was used in conjunction with the earlier 2-D program GAMNAS to develop the new program NAS3D for geometric nonlinear analysis. A conventional, modified Newton-Raphson process is used for the nonlinear analysis. New schemes for the computation of stiffness and strain energy release rates is presented. The organization the program is explained and some results on four sample problems are given. The study of CPU times showed that savings by a factor of 11 to 13 were achieved when vectorized computation was used for the stiffness instead of the conventional scalar one. Finally, the scheme of inputting data is explained.

  3. Plio-Pleistocene history and phylogeography of Acacia senegal in dry woodlands and savannahs of sub-Saharan tropical Africa: evidence of early colonisation and recent range expansion

    PubMed Central

    Odee, D W; Telford, A; Wilson, J; Gaye, A; Cavers, S

    2012-01-01

    Drylands are extensive across sub-Saharan Africa, socio-economically and ecologically important yet highly sensitive to environmental changes. Evolutionary history, as revealed by contemporary intraspecific genetic variation, can provide valuable insight into how species have responded to past environmental and population changes and guide strategies to promote resilience to future changes. The gum arabic tree (Acacia senegal) is an arid-adapted, morphologically diverse species native to the sub-Saharan drylands. We used variation in nuclear sequences (internal transcribed spacer (ITS)) and two types of chloroplast DNA (cpDNA) markers (PCR-RFLP, cpSSR) to study the phylogeography of the species with 293 individuals from 66 populations sampled across its natural range. cpDNA data showed high regional and rangewide haplotypic diversity (hT(cpSSR)=0.903–0.948) and population differentiation (GST(RFLP)=0.700–0.782) with a phylogeographic pattern that indicated extensive historical gene flow via seed dispersal. Haplotypes were not restricted to any of the four varieties, but showed significant geographic structure (GST(cpSSR)=0.392; RST=0.673; RST>RST (permuted)), with the major division separating East and Southern Africa populations from those in West and Central Africa. Phylogenetic analysis of ITS data indicated a more recent origin for the clade including West and Central African haplotypes, suggesting range expansion in this region, possibly during the Holocene humid period. In conjunction with paleobotanical evidence, our data suggest dispersal to West Africa, and across to the Arabian Peninsula and Indian subcontinent, from source populations located in the East African region during climate oscillations of the Plio-Pleistocene. PMID:22929152

  4. Remote Sensing Field Guide - Desert

    DTIC Science & Technology

    1991-09-01

    rcatching on fire. Caution is advised against thorns on acacia trees, spikey Spinifex n•shes, and several different types of venomous snakes, as well as...e.g., mesquite, many acacias, Spinifex . DESERT PROCESSES WORKING GROUP PATTERN INDICATOR SHFET - DESERT DUNES PHOTOS: GROUND VEGETATION MOUNDS LOCATION...deliberate burning of natural vegetation is done episodically by the abo- rginal inhabitants. They burn the mature vegetation (primarily Spinifex ), which is

  5. NAS-Wide Fast-Time Simulation Study for Evaluating Performance of UAS Detect-and-Avoid Alerting and Guidance Systems

    NASA Technical Reports Server (NTRS)

    Lee, Seung Man; Park, Chunki; Cone, Andrew Clayton; Thipphavong, David P.; Santiago, Confesor

    2016-01-01

    This presentation contains the analysis results of NAS-wide fast-time simulations with UAS and VFR traffic for a single day for evaluating the performance of Detect-and-Avoid (DAA) alerting and guidance systems. This purpose of this study was to help refine and validate MOPS alerting and guidance requirements. In this study, we generated plots of all performance metrics that are specified by RTCA SC-228 Minimum Operational Performance Standards (MOPS): 1) to evaluate the sensitivity of alerting parameters on the performance metrics of each DAA alert type: Preventive, Corrective, and Warning alerts and 2) to evaluate the effect of sensor uncertainty on DAA alerting and guidance performance.

  6. Evolution and ecology meet molecular genetics: adaptive phenotypic plasticity in two isolated Negev desert populations of Acacia raddiana at either end of a rainfall gradient

    PubMed Central

    Ward, David; Shrestha, Madan K.; Golan-Goldhirsh, Avi

    2012-01-01

    Background and Aims The ecological, evolutionary and genetic bases of population differentiation in a variable environment are often related to the selection pressures that plants experience. We compared differences in several growth- and defence-related traits in two isolated populations of Acacia raddiana trees from sites at either end of an extreme environmental gradient in the Negev desert. Methods We used random amplified polymorphic DNA (RAPD) to determine the molecular differences between populations. We grew plants under two levels of water, three levels of nutrients and three levels of herbivory to test for phenotypic plasticity and adaptive phenotypic plasticity. Key Results The RAPD analyses showed that these populations are highly genetically differentiated. Phenotypic plasticity in various morphological traits in A. raddiana was related to patterns of population genetic differentiation between the two study sites. Although we did not test for maternal effects in these long-lived trees, significant genotype × environment (G × E) interactions in some of these traits indicated that such plasticity may be adaptive. Conclusions The main selection pressure in this desert environment, perhaps unsurprisingly, is water. Increased water availability resulted in greater growth in the southern population, which normally receives far less rain than the northern population. Even under the conditions that we defined as low water and/or nutrients, the performance of the seedlings from the southern population was significantly better, perhaps reflecting selection for these traits. Consistent with previous studies of this genus, there was no evidence of trade-offs between physical and chemical defences and plant growth parameters in this study. Rather, there appeared to be positive correlations between plant size and defence parameters. The great variation in several traits in both populations may result in a diverse potential for responding to selection pressures in

  7. Extensive long-distance pollen dispersal and highly outcrossed mating in historically small and disjunct populations of Acacia woodmaniorum (Fabaceae), a rare banded iron formation endemic.

    PubMed

    Millar, Melissa A; Coates, David J; Byrne, Margaret

    2014-10-01

    Understanding patterns of pollen dispersal and variation in mating systems provides insights into the evolutionary potential of plant species and how historically rare species with small disjunct populations persist over long time frames. This study aims to quantify the role of pollen dispersal and the mating system in maintaining contemporary levels of connectivity and facilitating persistence of small populations of the historically rare Acacia woodmaniorum. Progeny arrays of A. woodmaniorum were genotyped with nine polymorphic microsatellite markers. A low number of fathers contributed to seed within single pods; therefore, sampling to remove bias of correlated paternity was implemented for further analysis. Pollen immigration and mating system parameters were then assessed in eight populations of varying size and degree of isolation. Pollen immigration into small disjunct populations was extensive (mean minimum estimate 40 % and mean maximum estimate 57 % of progeny) and dispersal occurred over large distances (≤1870m). Pollen immigration resulted in large effective population sizes and was sufficient to ensure adaptive and inbreeding connectivity in small disjunct populations. High outcrossing (mean tm = 0·975) and a lack of apparent inbreeding suggested that a self-incompatibility mechanism is operating. Population parameters, including size and degree of geographic disjunction, were not useful predictors of pollen dispersal or components of the mating system. Extensive long-distance pollen dispersal and a highly outcrossed mating system are likely to play a key role in maintaining genetic diversity and limiting negative genetic effects of inbreeding and drift in small disjunct populations of A. woodmaniorum. It is proposed that maintenance of genetic connectivity through habitat and pollinator conservation will be a key factor in the persistence of this and other historically rare species with similar extensive long-distance pollen dispersal and highly

  8. Impact of rhizobial inoculation on Acacia senegal (L.) Willd. growth in greenhouse and soil functioning in relation to seed provenance and soil origin.

    PubMed

    Bakhoum, Niokhor; Ndoye, Fatou; Kane, Aboubacry; Assigbetse, Komi; Fall, Dioumacor; Sylla, Samba Ndao; Noba, Kandioura; Diouf, Diégane

    2012-07-01

    Rhizobial inoculation has a positive impact on plants growth; however, there is little information about its effect on soil microbial communities and their activity in the rhizosphere. It was therefore necessary to test the effect of inoculation of Acacia senegal (L.) Willd. seedlings with selected rhizobia on plant growth, structure and diversity of soil bacterial communities and soil functioning in relation to plant provenance and soil origin. In order to carry out this experiment, three A. senegal seeds provenance from Kenya, Niger, and Senegal were inoculated with selected rhizobial strains. They have been further grown during 4 months in greenhouse conditions in two non-disinfected soils, Dahra and Goudiry coming respectively from arid and semi-arid areas. The principal component analysis (ACP) showed an inoculation effect on plant growth, rhizospheric bacterial diversity and soil functioning. However, the performances of the rhizobial strains varied in relation to the seed provenance and the soil origin. The selected rhizobial strains, the A. senegal provenance and the soil origin have modified the structure and the diversity of soil bacterial communities as measured by principal component analysis/denaturing gradient gel electrophoresis analyses. It is interesting to note that bacterial communities of Dahra soil were highly structured according to A. senegal provenance, whereas they were structured in relation to rhizobial inoculation in Goudiry soil. Besides, the impact of inoculation on soil microbial activities measured by fluorescein diacetate analyses varied in relation to plant provenance and soil origin. Nevertheless, total microbial activity was about two times higher in Goudiry, arid soil than in Dahra, semi-arid soil. Our results suggest that the rhizobial inoculation is a suitable tool for improving plants growth and soil fertility. Yet, the impact is dependent on inoculants, plant provenance and soil origin. It will, therefore, be crucial to

  9. Detecting hierarchical levels of connectivity in a population of Acacia tortilis at the northern edge of the species' global distribution: Combining classical population genetics and network analyses.

    PubMed

    Rodger, Yael S; Greenbaum, Gili; Silver, Micha; Bar-David, Shirli; Winters, Gidon

    2018-01-01

    Genetic diversity and structure of populations at the edge of the species' spatial distribution are important for potential adaptation to environmental changes and consequently, for the long-term survival of the species. Here, we combined classical population genetic methods with newly developed network analyses to gain complementary insights into the genetic structure and diversity of Acacia tortilis, a keystone desert tree, at the northern edge of its global distribution, where the population is under threat from climatic, ecological, and anthropogenic changes. We sampled A. tortilis from 14 sites along the Dead Sea region and the Arava Valley in Israel and in Jordan. In addition, we obtained samples from Egypt and Sudan, the hypothesized origin of the species. Samples from all sites were genotyped using six polymorphic microsatellite loci.Our results indicate a significant genetic structure in A. tortilis along the Arava Valley. This was detected at different hierarchical levels-from the basic unit of the subpopulation, corresponding to groups of trees within ephemeral rivers (wadis), to groups of subpopulations (communities) that are genetically more connected relative to others. The latter structure mostly corresponds to the partition of the major drainage basins in the area. Network analyses, combined with classical methods, allowed for the identification of key A. tortilis subpopulations in this region, characterized by their relatively high level of genetic diversity and centrality in maintaining gene flow in the population. Characterizing such key subpopulations may enable conservation managers to focus their efforts on certain subpopulations that might be particularly important for the population's long-term persistence, thus contributing to species conservation within its peripheral range.

  10. [Inventive activity of the Department of Molecular Immunology of the Palladin Institute of Biochemistry of NAS of Ukraine].

    PubMed

    Danilova, V M; Vynogradova, R P; Torkhova, S G

    2016-01-01

    The article is devoted to the inventive activity of the Department of Molecular Immunology of the Palladin Institute of Biochemistry of NAS of Ukraine in the context of the history of its inception, development and in the context of scholarly and organizational activities of Sergii Vasyl’ovych Komisarenko. This autumn marks 50th anniversary since young Sergii Komisarenko (now – Academician of NAS and NAMS of Ukraine, Dr. Biol. Sci., Professor) has joined the Palladin Institute of Biochemistry, has completed all stages of the academic carrier from PhD student to Head of the Institute. He is the first in Ukraine who started the new branch of research – molecular immunology, created a strong scientific school, which earned worldwide acclaim and made significant contribution to finding solutions to current problems in human health sciences. S.V. Komisarenko was among those, who were first in the USSR to use immunoenzyme and flow cytofluometric assays, hybridoma technology for producing monoclonal antibodies and immunochemical assay of proteins, which became the basis for development of highly sensitive and highly specific immunodiagnostic systems, which are of high necessity in medicine, veterinary, development of immunotechnologies, environment monitoring, etc. Under his leadership the Department has made a series of important discoveries and developments including relating to antitumour immunotoxins, effects of low dose radiation on the immune system of Chernobyl liquidators, immunochemical structure of neurotoxin apamine, cytochrom c, fibrinogen and fibrin molecules at different stages of polymerization, diphtheria toxin and its receptor, tuberculosis causing micobacterium, roles of protease-activated receptors (PARs) and nicotinic acetylcholine receptors of lymphocytes, nature of polyreactive immunoglobulins (PRIGs), among other important scientific contributions. S.V. Komisarenko and his colleagues also hold numerous (more than 80) author’s certificates

  11. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project

    NASA Technical Reports Server (NTRS)

    Shively, Jay

    2017-01-01

    Over the past 5 years, the UAS integration into the NAS project has worked to reduce technical barriers to integration. A major focus of this work has been in support of RTCA SC-228. This committee has recently published the first UAS integration minimum performance standards (MOPS). This work has spanned detect and avoid (DAA) as well as command and control comm datalinks. I will discuss DAA efforts with focus on the human systems work. I will discuss how automation was discussed and addressed within this context. ICAO stood up a remotely piloted aircraft systems (RPAS) panel in 2014. They have developed an RPAS manual and are now working to revise existing annexes and standards and recommended practices. The Human In The System (HITS) has worked to infuse human factors guidelines into those documents. I will discuss that effort as well as how ICAO has defined and address autonomy. There is a great deal of interest in the control of multiple vehicles by a single operator. The UAS EXCOM Science and Research Panel (SARP) is holding a workshop on this topic in late June. I will discuss research performed on this topic when I worked for the Army and on-going work within the division and a NATO working group on Human-Autonomy Teaming.

  12. Effect of Inoculation of Acacia senegal mature trees with Mycorrhiza and Rhizobia on soil properties and microbial community structure

    NASA Astrophysics Data System (ADS)

    Assigbetsé, K.; Ciss, I.; Bakhoum, N.; Dieng, L.

    2012-04-01

    Inoculation of legume plants with symbiotic microorganisms is widely used to improve their development and productivity. The objective of this study was to investigate the effect of inoculation of Acacia senegal mature trees with rhizobium (Sinorhizobium) and arbuscular mycorrhizal fungus (G. mosseae, G. fasciculatum, G. intraradices) either singly or in combination, on soil properties, activity and the genetic structure of soil microbial communities. The experiment set up in Southern Senegal consisted of 4 randomized blocks of A. senegal mature trees with 4 treatments including inoculated trees with Rhizobium (R), mycorrhizal fungus (M) and with Rhizobium+mycorhizal fungus (RM) and non-inoculated control (CON). Soil were sampled 2 years after the inoculation. Soil pH, C and N and available P contents were measured. The microbial abundance and activity were measured in terms of microbial biomass C (MBC) and basal soil respiration. The community structure of the total bacterial, diazotrophic and denitrifying communities was assessed by denaturing gradient gel electrophoresis of 16S rDNA, nifH and nirK genes respectively. Inoculations with symbiont under field conditions have increased soil pH. The C and N contents were enhanced in the dual-inoculated treatments (RM). The mycorrhized treatment have displayed the lowest available P contents while RM and R treatments exhibited higher contents rates. The microbial biomass C rates were higher in treatments co-inoculated with AM fungi and Rhizobium than in those inoculated singly with AM fungi or Rhizobium strains. The basal soil respiration were positively correlated to MBC, and the highest rates were found in the co-inoculated treatments. Fingerprints of 16S rDNA gene exhibited similar patterns between inoculated treatments and the control showing that the inoculation of mature trees have not impacted the total bacterial community structure. In contrast, the inoculated treatments have displayed individually different

  13. Survival, growth, and body residues of hyalella azteca (Saussure) exposed to fipronil contaminated sediments from non-vegetated and vegetated microcosms.

    PubMed

    Kröger, Robert; Lizotte, Richard E; Moore, Matthew T

    2009-09-01

    We assessed chronic effects of fipronil and metabolite contaminated sediments from non-vegetated and Thallia dealbata vegetated wetland microcosms on Hyalella azteca during wet and dry exposures. Mean sediment concentrations (ng g(-1)) ranged from 0.72-1.26, 0.01-0.69, 0.07-0.23, and 0.49-7.87 for fipronil, fipronil-sulfide, fipronil-sulfone, and fipronil-desulfinyl, respectively. No significant differences in animal survival or growth were observed between non-vegetated and vegetated microcosms during wet or dry exposures. Mean animal body residue concentrations (ng g(-1)) ranged from 28.4-77.6, 0-30.7, and 8.3-43.8 for fipronil, fipronil-sulfide, and fipronil-sulfone. Fipronil-desulfinyl was not detected in any animal samples.

  14. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project, UAS Control and Non-Payload Communication System Phase-1 Flight Test Results

    NASA Technical Reports Server (NTRS)

    Griner, James H.

    2014-01-01

    NASA's UAS Integration in the NAS project, has partnered with Rockwell Collins to develop a concept Control and Non-Payload Communication (CNPC) system prototype radio, operating on recently allocated UAS frequency spectrum bands. This prototype radio is being used to validate initial proposed performance requirements for UAS control communications. This presentation will give an overview of the current status of the prototype radio development, and results from phase 1 flight tests conducted during 2013.

  15. A randomized, prospective, comparison study of a mixture of acacia fiber, psyllium fiber, and fructose vs polyethylene glycol 3350 with electrolytes for the treatment of chronic functional constipation in childhood.

    PubMed

    Quitadamo, Paolo; Coccorullo, Paola; Giannetti, Eleonora; Romano, Claudio; Chiaro, Andrea; Campanozzi, Angelo; Poli, Emanuela; Cucchiara, Salvatore; Di Nardo, Giovanni; Staiano, Annamaria

    2012-10-01

    To compare the effectiveness of a mixture of acacia fiber, psyllium fiber, and fructose (AFPFF) with polyethylene glycol 3350 combined with electrolytes (PEG+E) in the treatment of children with chronic functional constipation (CFC); and to evaluate the safety and effectiveness of AFPFF in the treatment of children with CFC. This was a randomized, open label, prospective, controlled, parallel-group study involving 100 children (M/F: 38/62; mean age ± SD: 6.5 ± 2.7 years) who were diagnosed with CFC according to the Rome III Criteria. Children were randomly divided into 2 groups: 50 children received AFPFF (16.8 g daily) and 50 children received PEG+E (0.5 g/kg daily) for 8 weeks. Primary outcome measures were frequency of bowel movements, stool consistency, fecal incontinence, and improvement of other associated gastrointestinal symptoms. Safety was assessed with evaluation of clinical adverse effects and growth measurements. Compliance rates were 72% for AFPFF and 96% for PEG+E. A significant improvement of constipation was seen in both groups. After 8 weeks, 77.8% of children treated with AFPFF and 83% of children treated with PEG+E had improved (P = .788). Neither PEG+E nor AFPFF caused any clinically significant side effects during the entire course of the study period. In this randomized study, we did not find any significant difference between the efficacy of AFPFF and PEG+E in the treatment of children with CFC. Both medications were proved to be safe for CFC treatment, but PEG+E was better accepted by children. Copyright © 2012 Mosby, Inc. All rights reserved.

  16. Evaluation of Selected Immunomodulatory Glycoproteins as an Adjunct to Cancer Immunotherapy

    PubMed Central

    Sekhon, Bhagwant Kaur; Li, Yiming; Devi, Parimala B.; Nammi, Srinivas; Fan, Kei

    2016-01-01

    Polysaccharopeptide (PSP), from Coriolus versicolor, has been used widely as an adjuvant to chemotherapy with demonstrated anti-tumor and broad immunomodulating effects. While PSP’s mechanism of action still remains unknown, its enhanced immunomodulatory potential with acacia gum is of great interest. Acacia gum, which also contains polysaccharides and glycoproteins, has been demonstrated to be immunopotentiating. To elucidate whether PSP directly activates T-cell-dependent B-cell responses in vivo, we used a well-established hapten carrier system (Nitrophenyl-chicken gamma globulin (NP-CGG)). 6-week C57BL/6 male mice were immunised with 50 μg of NP25-CGG alum precipitate intraperitoneally. Mice were gavaged daily with 50mg/kg PSP in a vehicle containing acacia gum and sacrificed at days 0, 4, 7, 10, 14 and 21. ELISA was used to measure the total and relative hapten-specific anti-NP IgA, IgM and IgG titre levels compared to the controls. It was found that PSP, combined with acacia gum, significantly increased total IgG titre levels at day 4 (P< 0.05), decreased IgM titre levels at days 4 and 21 (P< 0.05) with no alterations observed in the IgA or IgE titre levels at any of the time points measured. Our results suggest that while PSP combined with acacia gum appears to exert weak immunological effects through specific T-cell dependent B-cell responses, they are likely to be broad and non-specific which supports the current literature on PSP. We report for the first time the application of a well-established hapten-carrier system that can be used to characterise and delineate specific T-cell dependent B-cell responses of potential immunomodulatory glycoprotein-based herbal medicines combinations in vivo. PMID:26799072

  17. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project: Detect and Avoid Display Evaluations in Support of SC-228 Minimum Operational Performance Standards Development

    NASA Technical Reports Server (NTRS)

    Fern, Lisa Carolynn

    2017-01-01

    The primary activity for the UAS-NAS Human Systems Integration (HSI) sub-project in Phase 1 was support of RTCA Special Committee 228 Minimum Operational Performance Standards (MOPS). We provide data on the effect of various Detect and Avoid (DAA) display features with respect to pilot performance of the remain well clear function in order to determine the minimum requirements for DAA displays.

  18. Realization of Vilnius UPXYZVS photometric system for AltaU42 CCD camera at the MAO NAS of Ukraine

    NASA Astrophysics Data System (ADS)

    Vid'Machenko, A. P.; Andruk, V. M.; Samoylov, V. S.; Delets, O. S.; Nevodovsky, P. V.; Ivashchenko, Yu. M.; Kovalchuk, G. U.

    2005-06-01

    The description of two-inch glass filters of the Vilnius UPXYZVS photometric system, which are made at the Main Astronomical Observatory of NAS of Ukraine for AltaU42 CCD camera with format of 2048×2048 pixels, is presented in the paper. Reaction curves of instrumental system are shown. Estimations of minimal star's magnitudes for each filter's band in comparison with the visual V one are obtained. New software for automation of CCD frames processing is developed in program shell of LINUX/MIDAS/ROMAFOT. It is planned to carry out observations with the purpose to create the catalogue of primary UPXYZVS CCD standards in selected field of the sky for some radio-sources, globular and open clusters, etc. Numerical estimations of astrometric and photometric accuracy are obtained.

  19. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project: Terminal Operations HITL 1B Primary Results

    NASA Technical Reports Server (NTRS)

    Rorie, Conrad; Monk, Kevin; Roberts, Zach; Brandt, Summer

    2018-01-01

    This presentation provides an overview of the primary results from the Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project's second Terminal Operations human-in-the-loop simulation. This talk covers the background of this follow-on experiment, which includes an overview of the first Terminal Operations HITL performed by the project. The primary results include a look at the number and durations of detect and avoid (DAA) alerts issued by the two DAA systems under test. It also includes response time metrics and metrics on the ability of the pilot-in-command (PIC) to maintain sufficient separation. Additional interoperability metrics are included to illustrate how pilots interact with the tower controller. Implications and conclusions are covered at the end.

  20. Effects of Alien Plants on Ecosystem Structure and Functioning and Implications for Restoration: Insights from Three Degraded Sites in South African Fynbos

    NASA Astrophysics Data System (ADS)

    Gaertner, Mirijam; Richardson, David M.; Privett, Sean D. J.

    2011-07-01

    We investigated the type and extent of degradation at three sites on the Agulhas Plain, South Africa: an old field dominated by the alien grass Pennisetum clandestinum Pers . (kikuyu), an abandoned Eucalyptus plantation, and a natural fynbos community invaded by nitrogen fixing—Australian Acacia species. These forms of degradation are representative of many areas in the region. By identifying the nature and degree of ecosystem degradation we aimed to determine appropriate strategies for restoration in this biodiversity hotspot. Vegetation surveys were conducted at degraded sites and carefully selected reference sites. Soil-stored propagule seed banks and macro- and micro-soil nutrients were determined. Species richness, diversity and native cover under Eucalyptus were extremely low compared to the reference site and alterations of the soil nutrients were the most severe. The cover of indigenous species under Acacia did not differ significantly from that in reference sites, but species richness was lower under Acacia and soils were considerably enriched. Native species richness was much lower in the kikuyu site, but soil nutrient status was similar to the reference site. Removal of the alien species alone may be sufficient to re-initiate ecosystem recovery at the kikuyu site, whereas active restoration is required to restore functioning ecosystems dominated by native species in the Acacia thicket and the Eucalyptus plantation. To restore native plant communities we suggest burning, mulching with sawdust and sowing of native species.

  1. Effect of hyperfine-induced spin mixing on the defect-enabled spin blockade and spin filtering in GaNAs

    NASA Astrophysics Data System (ADS)

    Puttisong, Y.; Wang, X. J.; Buyanova, I. A.; Chen, W. M.

    2013-03-01

    The effect of hyperfine interaction (HFI) on the recently discovered room-temperature defect-enabled spin-filtering effect in GaNAs alloys is investigated both experimentally and theoretically based on a spin Hamiltonian analysis. We provide direct experimental evidence that the HFI between the electron and nuclear spin of the central Ga atom of the spin-filtering defect, namely, the Gai interstitials, causes strong mixing of the electron spin states of the defect, thereby degrading the efficiency of the spin-filtering effect. We also show that the HFI-induced spin mixing can be suppressed by an application of a longitudinal magnetic field such that the electronic Zeeman interaction overcomes the HFI, leading to well-defined electron spin states beneficial to the spin-filtering effect. The results provide a guideline for further optimization of the defect-engineered spin-filtering effect.

  2. Fungal Planet description sheets: 625-715.

    PubMed

    Crous, P W; Wingfield, M J; Burgess, T I; Carnegie, A J; Hardy, G E St J; Smith, D; Summerell, B A; Cano-Lira, J F; Guarro, J; Houbraken, J; Lombard, L; Martín, M P; Sandoval-Denis, M; Alexandrova, A V; Barnes, C W; Baseia, I G; Bezerra, J D P; Guarnaccia, V; May, T W; Hernández-Restrepo, M; Stchigel, A M; Miller, A N; Ordoñez, M E; Abreu, V P; Accioly, T; Agnello, C; Agustin Colmán, A; Albuquerque, C C; Alfredo, D S; Alvarado, P; Araújo-Magalhães, G R; Arauzo, S; Atkinson, T; Barili, A; Barreto, R W; Bezerra, J L; Cabral, T S; Camello Rodríguez, F; Cruz, R H S F; Daniëls, P P; da Silva, B D B; de Almeida, D A C; de Carvalho Júnior, A A; Decock, C A; Delgat, L; Denman, S; Dimitrov, R A; Edwards, J; Fedosova, A G; Ferreira, R J; Firmino, A L; Flores, J A; García, D; Gené, J; Giraldo, A; Góis, J S; Gomes, A A M; Gonçalves, C M; Gouliamova, D E; Groenewald, M; Guéorguiev, B V; Guevara-Suarez, M; Gusmão, L F P; Hosaka, K; Hubka, V; Huhndorf, S M; Jadan, M; Jurjević, Ž; Kraak, B; Kučera, V; Kumar, T K A; Kušan, I; Lacerda, S R; Lamlertthon, S; Lisboa, W S; Loizides, M; Luangsa-Ard, J J; Lysková, P; Mac Cormack, W P; Macedo, D M; Machado, A R; Malysheva, E F; Marinho, P; Matočec, N; Meijer, M; Mešić, A; Mongkolsamrit, S; Moreira, K A; Morozova, O V; Nair, K U; Nakamura, N; Noisripoom, W; Olariaga, I; Oliveira, R J V; Paiva, L M; Pawar, P; Pereira, O L; Peterson, S W; Prieto, M; Rodríguez-Andrade, E; Rojo De Blas, C; Roy, M; Santos, E S; Sharma, R; Silva, G A; Souza-Motta, C M; Takeuchi-Kaneko, Y; Tanaka, C; Thakur, A; Smith, M Th; Tkalčec, Z; Valenzuela-Lopez, N; van der Kleij, P; Verbeken, A; Viana, M G; Wang, X W; Groenewald, J Z

    2017-12-01

    Novel species of fungi described in this study include those from various countries as follows: Antarctica : Cadophora antarctica from soil. Australia : Alfaria dandenongensis on Cyperaceae , Amphosoma persooniae on Persoonia sp., Anungitea nullicana on Eucalyptus sp . , Bagadiella eucalypti on Eucalyptus globulus , Castanediella eucalyptigena on Eucalyptus sp., Cercospora dianellicola on Dianella sp., Cladoriella kinglakensis on Eucalyptus regnans , Cladoriella xanthorrhoeae (incl. Cladoriellaceae fam. nov. and Cladoriellales ord. nov.) on Xanthorrhoea sp., Cochlearomyces eucalypti (incl. Cochlearomyces gen. nov. and Cochlearomycetaceae fam. nov.) on Eucalyptus obliqua , Codinaea lambertiae on Lambertia formosa , Diaporthe obtusifoliae on Acacia obtusifolia , Didymella acaciae on Acacia melanoxylon , Dothidea eucalypti on Eucalyptus dalrympleana , Fitzroyomyces cyperi (incl. Fitzroyomyces gen. nov.) on Cyperaceae , Murramarangomyces corymbiae (incl. Murramarangomyces gen. nov., Murramarangomycetaceae fam. nov. and Murramarangomycetales ord. nov.) on Corymbia maculata , Neoanungitea eucalypti (incl. Neoanungitea gen. nov.) on Eucalyptus obliqua , Neoconiothyrium persooniae (incl. Neoconiothyrium gen. nov.) on Persoonia laurina subsp. laurina , Neocrinula lambertiae (incl. Neocrinulaceae fam. nov.) on Lambertia sp., Ochroconis podocarpi on Podocarpus grayae , Paraphysalospora eucalypti (incl. Paraphysalospora gen. nov.) on Eucalyptus sieberi , Pararamichloridium livistonae (incl. Pararamichloridium gen. nov., Pararamichloridiaceae fam. nov. and Pararamichloridiales ord. nov.) on Livistona sp., Pestalotiopsis dianellae on Dianella sp., Phaeosphaeria gahniae on Gahnia aspera , Phlogicylindrium tereticornis on Eucalyptus tereticornis , Pleopassalora acaciae on Acacia obliquinervia , Pseudodactylaria xanthorrhoeae (incl. Pseudodactylaria gen. nov., Pseudodactylariaceae fam. nov. and Pseudodactylariales ord. nov.) on Xanthorrhoea sp., Pseudosporidesmium lambertiae (incl

  3. Fungal Planet description sheets: 469-557.

    PubMed

    Crous, P W; Wingfield, M J; Burgess, T I; Hardy, G E St J; Crane, C; Barrett, S; Cano-Lira, J F; Le Roux, J J; Thangavel, R; Guarro, J; Stchigel, A M; Martín, M P; Alfredo, D S; Barber, P A; Barreto, R W; Baseia, I G; Cano-Canals, J; Cheewangkoon, R; Ferreira, R J; Gené, J; Lechat, C; Moreno, G; Roets, F; Shivas, R G; Sousa, J O; Tan, Y P; Wiederhold, N P; Abell, S E; Accioly, T; Albizu, J L; Alves, J L; Antoniolli, Z I; Aplin, N; Araújo, J; Arzanlou, M; Bezerra, J D P; Bouchara, J-P; Carlavilla, J R; Castillo, A; Castroagudín, V L; Ceresini, P C; Claridge, G F; Coelho, G; Coimbra, V R M; Costa, L A; da Cunha, K C; da Silva, S S; Daniel, R; de Beer, Z W; Dueñas, M; Edwards, J; Enwistle, P; Fiuza, P O; Fournier, J; García, D; Gibertoni, T B; Giraud, S; Guevara-Suarez, M; Gusmão, L F P; Haituk, S; Heykoop, M; Hirooka, Y; Hofmann, T A; Houbraken, J; Hughes, D P; Kautmanová, I; Koppel, O; Koukol, O; Larsson, E; Latha, K P D; Lee, D H; Lisboa, D O; Lisboa, W S; López-Villalba, Á; Maciel, J L N; Manimohan, P; Manjón, J L; Marincowitz, S; Marney, T S; Meijer, M; Miller, A N; Olariaga, I; Paiva, L M; Piepenbring, M; Poveda-Molero, J C; Raj, K N A; Raja, H A; Rougeron, A; Salcedo, I; Samadi, R; Santos, T A B; Scarlett, K; Seifert, K A; Shuttleworth, L A; Silva, G A; Silva, M; Siqueira, J P Z; Souza-Motta, C M; Stephenson, S L; Sutton, D A; Tamakeaw, N; Telleria, M T; Valenzuela-Lopez, N; Viljoen, A; Visagie, C M; Vizzini, A; Wartchow, F; Wingfield, B D; Yurchenko, E; Zamora, J C; Groenewald, J Z

    2016-12-01

    Novel species of fungi described in this study include those from various countries as follows: Australia : Apiognomonia lasiopetali on Lasiopetalum sp., Blastacervulus eucalyptorum on Eucalyptus adesmophloia , Bullanockia australis (incl. Bullanockia gen. nov.) on Kingia australis , Caliciopsis eucalypti on Eucalyptus marginata , Celerioriella petrophiles on Petrophile teretifolia , Coleophoma xanthosiae on Xanthosia rotundifolia , Coniothyrium hakeae on Hakea sp., Diatrypella banksiae on Banksia formosa , Disculoides corymbiae on Corymbia calophylla , Elsinoë eelemani on Melaleuca alternifolia , Elsinoë eucalyptigena on Eucalyptus kingsmillii , Elsinoë preissianae on Eucalyptus preissiana , Eucasphaeria rustici on Eucalyptus creta , Hyweljonesia queenslandica (incl. Hyweljonesia gen. nov.) on the cocoon of an unidentified microlepidoptera, Mycodiella eucalypti (incl. Mycodiella gen. nov.) on Eucalyptus diversicolor , Myrtapenidiella sporadicae on Eucalyptus sporadica , Neocrinula xanthorrhoeae (incl. Neocrinula gen. nov.) on Xanthorrhoea sp., Ophiocordyceps nooreniae on dead ant, Phaeosphaeriopsis agavacearum on Agave sp., Phlogicylindrium mokarei on Eucalyptus sp., Phyllosticta acaciigena on Acacia suaveolens , Pleurophoma acaciae on Acacia glaucoptera , Pyrenochaeta hakeae on Hakea sp., Readeriella lehmannii on Eucalyptus lehmannii , Saccharata banksiae on Banksia grandis , Saccharata daviesiae on Daviesia pachyphylla , Saccharata eucalyptorum on Eucalyptus bigalerita , Saccharata hakeae on Hakea baxteri , Saccharata hakeicola on Hakea victoria , Saccharata lambertiae on Lambertia ericifolia , Saccharata petrophiles on Petrophile sp., Saccharata petrophilicola on Petrophile fastigiata , Sphaerellopsis hakeae on Hakea sp., and Teichospora kingiae on Kingia australis. Brazil : Adautomilanezia caesalpiniae (incl . Adautomilanezia gen. nov.) on Caesalpina echinata , Arthrophiala arthrospora (incl. Arthrophiala gen. nov.) on Sagittaria montevidensis , Diaporthe

  4. The solution of linear systems of equations with a structural analysis code on the NAS CRAY-2

    NASA Technical Reports Server (NTRS)

    Poole, Eugene L.; Overman, Andrea L.

    1988-01-01

    Two methods for solving linear systems of equations on the NAS Cray-2 are described. One is a direct method; the other is an iterative method. Both methods exploit the architecture of the Cray-2, particularly the vectorization, and are aimed at structural analysis applications. To demonstrate and evaluate the methods, they were installed in a finite element structural analysis code denoted the Computational Structural Mechanics (CSM) Testbed. A description of the techniques used to integrate the two solvers into the Testbed is given. Storage schemes, memory requirements, operation counts, and reformatting procedures are discussed. Finally, results from the new methods are compared with results from the initial Testbed sparse Choleski equation solver for three structural analysis problems. The new direct solvers described achieve the highest computational rates of the methods compared. The new iterative methods are not able to achieve as high computation rates as the vectorized direct solvers but are best for well conditioned problems which require fewer iterations to converge to the solution.

  5. Air Traffic Controller Performance and Acceptability of Multiple UAS in a Simulated NAS Environment

    NASA Technical Reports Server (NTRS)

    Vu, Kim-Phuong L.; Strybel, Thomas; Chiappe, Dan; Morales, Greg; Battiste, Vernol; Shively, Robert Jay

    2014-01-01

    Previously, we showed that air traffic controllers (ATCos) rated UAS pilot verbal response latencies as acceptable when a 1.5 s delay was added to the UAS pilot responses, but a 5 s delay was rated as mostly unacceptable. In the present study we determined whether a 1.5 s added delay in the UAS pilots' verbal communications would affect ATCos interactions with UAS and other conventional aircraft when the number and speed of the UAS were manipulated. Eight radar-certified ATCos participated in this simulation. The ATCos managed a medium altitude sector containing arrival aircraft, en route aircraft, and one to four UAS. The UAS were conducting a surveillance mission and flew at either a "slow" or "fast" speed. We measured both UAS and conventional pilots' verbal communication latencies, and obtained ATCos' acceptability ratings for these latencies. Although the UAS pilot response latencies were longer than those of conventional pilots, the ATCos rated UAS pilot verbal communication latencies to be as acceptable as those of conventional pilots. Because the overall traffic load within the sector was held constant, ATCos only performed slightly worse when multiple UAS were in their sector compared to when only one UAS was in the sector. Implications of these findings for UAS integration in the NAS are discussed.

  6. Optimal Blast Condition for the Inner Surface of Mass Produced NAS Battery Cylindrical Aluminum Cell Containers as Pretreatment of Thermal Spraying

    NASA Astrophysics Data System (ADS)

    Ando, Takashi; Harada, Yoshio

    The relationship between roughness caused by blasting and adhesion of spray coatings on aluminum container substrates was studied through various experiments as part of measures for improving the adhesion of the 75mass%Cr-Fe alloy plasma spray coating for sulfi dation corrosion resistance, which is applied on the inner surface of cylindrical Al containers of high-temperature type NAS batteries. Surface roughness of μmRa2.8 - 7.3 was acquired by using Al2O3 particle size #100 (212 - 75μm) to #46 (600 - 250μm) grit. In order to achieve uniform roughness and a clean surface, a combination of blasting when the nozzle was being inserted from the top of the container, and air blowing when the nozzle was being removed was done. It was determined that when Al2O3 particles of size #100 grit was used, a good anchoring shape was formed throughout with a roughened surface of μmRa 2.8. When the internal surface of 3000 Al cylindrical containers were continually blasted using particle size #100 grit, the initial surface roughness of μmRa3.7 - 3.9 only deteriorated to about μmRa2.6. A 75mass%Cr-Fe alloy spray coating was applied to the Al cylindrical containers that were roughened using particle size #100 grit. This coating showed cracks by a bending test, but no peeling occurred. This coating was examined by a tensile strength test and showed good adhesion at 64 - 66 MPa. Through experiments, it was proven that spray coatings formed on the Al cylindrical containers after receiving optimal blasting with particle size #100 grit had good adhesion and corrosion resistance after being used for NAS batteries that stored electrical power for about nine years.

  7. LNTgate: How scientific misconduct by the U.S. NAS led to governments adopting LNT for cancer risk assessment

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

    Calabrese, Edward J., E-mail: edwardc@schoolph.umass.edu

    This paper provides a detailed rebuttal to the letter of Beyea (2016) which offered a series of alternative interpretations to those offered in my article in Environmental Research (Calabrese, 2015a) concerning the role of the U.S. National Academy of Sciences (NAS) Biological Effects of Atomic Radiation (BEAR) I Committee Genetics Panel in the adoption of the linear dose response model for cancer risk assessment. Significant newly uncovered evidence is presented which supports and extends the findings of Calabrese (2015a), reaffirming the conclusion that the Genetics Panel should be evaluated for scientific misconduct for deliberate misrepresentation of the research record inmore » order to enhance an ideological agenda. This critique documents numerous factual errors along with extensive and deliberate filtering of information in the Beyea letter (2016) that leads to consistently incorrect conclusions and an invalid general perspective.« less

  8. Quantum oscillations and interference effects in strained n- and p-type modulation doped GaInNAs/GaAs quantum wells

    NASA Astrophysics Data System (ADS)

    Sarcan, F.; Nutku, F.; Donmez, O.; Kuruoglu, F.; Mutlu, S.; Erol, A.; Yildirim, S.; Arikan, M. C.

    2015-08-01

    We have performed magnetoresistance measurements on n- and p-type modulation doped GaInNAs/GaAs quantum well (QW) structures in both the weak (B  < 0.08 T) and the high magnetic field (up to 18 T) at 75 mK and 6 K. We observe that the quantum oscillations in {ρxx} and quantum Hall effect (QHE) plateaus in {ρxy} are affected from the presence of the nitrogen in the III-V lattice. The enhancement of N-related scatterings and electron effective mass with increasing nitrogen causes lower electron mobility and higher two-dimensional (2D) electron density, leading to suppressed QHE plateaus in {ρxy} up to 7 T at 6 K. The Shubnikov de Haas (SdH) oscillations develop at lower magnetic fields for higher mobility samples at 6 K and the amplitude of SdH oscillations decreases with increasing nitrogen composition. The well-pronounced QHE plateaus are observed at 75 mK and at higher magnetic fields up to 18 T, for the p-type sample. For n-type samples, the observed anomalies in the characteristic of QHE is attributed the nitrogen-related disorders and overlapping of fluctuating Landau levels. The low magnetic field measurements at 75 mK reveal that the n-type samples exhibit weak antilocalization, whereas weak localization is observed for the p-type sample. The observation of weak antilocalization is an indication of strong electron spin-orbit interactions. The low field magnetoresistance traces are used to extract the spin coherence, phase coherence and elastic scattering times as well Rashba parameters and spin-splitting energy. The calculated Rashba parameters for nitrogen containing samples reveal that the nitrogen composition is a significant parameter to determine the degree of the spin-orbit interactions. Consequently, GaInNAs-based QW structures with various nitrogen compositions can be beneficial to adjust the spin-orbit coupling strength and may be used as a candidate for spintronics applications.

  9. Considerations for RTCA Phase 2 Low Size, Weight, and Power (SWAP) Surveillance Requirements. UAS Integration in the NAS

    NASA Technical Reports Server (NTRS)

    Santiago, Confesor

    2017-01-01

    RTCA (Radio Technical Commission for Aeronautics) Special Committee 228 has initiated a second phase for the development of minimum operational performance standards (MOPS) for UAS (Unmanned Aircraft Systems) detect and avoid (DAA) systems. Technologies to enable UAS with less available Size, Weight, and Power (SWaP) will be considered. A white paper is in development for what topics and issues need to be addressed to develop DAA requirements for low SWAP surveillance systems. This briefing will document the issues to be investigated in SC-228. It will also serve as a review with the committee to get feedback so the white paper can be written and finalized. These topics and issues are not necessarily all the things that NASA will contribute to SC-228 during Phase 2, but what the overall committee needs to accomplish. A portion of the work will be in NASA's UAS in the NAS (National Airspace System) project plan.

  10. Testing New Programming Paradigms with NAS Parallel Benchmarks

    NASA Technical Reports Server (NTRS)

    Jin, H.; Frumkin, M.; Schultz, M.; Yan, J.

    2000-01-01

    Over the past decade, high performance computing has evolved rapidly, not only in hardware architectures but also with increasing complexity of real applications. Technologies have been developing to aim at scaling up to thousands of processors on both distributed and shared memory systems. Development of parallel programs on these computers is always a challenging task. Today, writing parallel programs with message passing (e.g. MPI) is the most popular way of achieving scalability and high performance. However, writing message passing programs is difficult and error prone. Recent years new effort has been made in defining new parallel programming paradigms. The best examples are: HPF (based on data parallelism) and OpenMP (based on shared memory parallelism). Both provide simple and clear extensions to sequential programs, thus greatly simplify the tedious tasks encountered in writing message passing programs. HPF is independent of memory hierarchy, however, due to the immaturity of compiler technology its performance is still questionable. Although use of parallel compiler directives is not new, OpenMP offers a portable solution in the shared-memory domain. Another important development involves the tremendous progress in the internet and its associated technology. Although still in its infancy, Java promisses portability in a heterogeneous environment and offers possibility to "compile once and run anywhere." In light of testing these new technologies, we implemented new parallel versions of the NAS Parallel Benchmarks (NPBs) with HPF and OpenMP directives, and extended the work with Java and Java-threads. The purpose of this study is to examine the effectiveness of alternative programming paradigms. NPBs consist of five kernels and three simulated applications that mimic the computation and data movement of large scale computational fluid dynamics (CFD) applications. We started with the serial version included in NPB2.3. Optimization of memory and cache usage

  11. Effect of polyethylene glycol 4000 supplementation on the performance of yearling male Pedi goats fed dietary mixture levels of Acacia karroo leaf meal and Setaria verticillata grass hay.

    PubMed

    Brown, David; Ng'ambi, Jones W

    2017-06-01

    Eighteen yearling male Pedi goats weighing 21.7 ± 3.1 kg were used in a 42-day trial in a 2 (Acacia karroo leaf meal levels) × 3 (levels of PEG 4000) factorial arrangement in a completely randomized design to determine PEG 4000 supplementation levels for optimal productivity of indigenous Pedi goats fed different mixture levels of A. karroo leaf meal and Setaria verticillata (L.) P.Beauv. grass hay. Each goat was supplemented with 0, 23 or 30 g of PEG 4000 per day in addition to dietary mixture of A. karroo and S. verticillata hay. Polyethylene glycol 4000 supplementation had no effect (P > 0.05) on nutrient intake of goats. However, a diet × PEG (P < 0.05) was observed for intake of all nutrients studied. Dry matter, OM, NDF and ADF intakes per goat were optimized at PEG 4000 supplementation levels of 19.62, 19.62, 19.61 and 19.53 g/goat/day, respectively, for diets containing 20% A. karroo leaf meal. Polyethylene glycol 4000 supplementation had no effect (P > 0.05) on the apparent digestibility of all nutrients. The dietary inclusion level of A. karroo leaf meal at 20% improved (P < 0.05) DM, OM, CP, NDF and ADF digestibility of goats. Crude protein digestibility was optimized at a PEG 4000 supplementation level of 15.78 g/goat/day. Dietary mixture level and PEG 4000 supplementation had no effect (P > 0.05) on final weights of Pedi goats. Similar results were observed for blood urea and glucose concentrations of yearling male Pedi goats. However, daily body weight gain was higher (P < 0.05) in goats fed 50% A. karroo leaf meal than those on 20% inclusion level. Polyethylene glycol 4000 has potential to improve the feeding value of tanninifeorus A. karroo leaf meal.

  12. Optical transitions in GaNAs quantum wells with variable nitrogen content embedded in AlGaAs

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

    Elborg, M., E-mail: ELBORG.Martin@nims.go.jp; Noda, T.; Mano, T.

    2016-06-15

    We investigate the optical transitions of GaN{sub x}As{sub 1−x} quantum wells (QWs) embedded in wider band gap AlGaAs. A combination of absorption and emission spectroscopic techniques is employed to systematically investigate the properties of GaNAs QWs with N concentrations ranging from 0 – 3%. From measurement of the photocurrent spectra, we find that besides QW ground state and first excited transition, distinct increases in photocurrent generation are observed. Their origin can be explained by N-induced modifications in the density of states at higher energies above the QW ground state. Photoluminescence experiments reveal that peak position dependence with temperature changes withmore » N concentration. The characteristic S-shaped dependence for low N concentrations of 0.5% changes with increasing N concentration where the low temperature red-shift of the S-shape gradually disappears. This change indicates a gradual transition from impurity picture, where localized N induced energy states are present, to alloying picture, where an impurity-band is formed. In the highest-N sample, photoluminescence emission shows remarkable temperature stability. This phenomenon is explained by the interplay of N-induced energy states and QW confined states.« less

  13. Física e Arte nas Estações do Ano

    NASA Astrophysics Data System (ADS)

    Pessôa Queiroz, Glória; da Conceição Barbosa Lima, Maria; Navarro Vasconcellos das Mercês, Maria

    2004-12-01

    The paper deals with the subject of the Four Seasons, exploring elements of Science and the Art in order to motivate students or public of museums of science and technology to understand it from their current cultural experiences and of old times. Physics joins to Astronomy to explain the phenomenon, while the use of Music and Painting make possible the immersion in the subject in way to many trips to the imagination capable to awake emotions.A proposal didactic is presented and justified for some consensus of the research in the area of teaching-learning of science, since that related to the persistent alternative conceptions concerning the causes of the changes observed at the different times of the year until the qualitative modelling of phenomena that appeals three-dimensional pedagogical models. Such proposal was developed in the activity named " Hiper interesting Talk: The Four Seasons, Science and Art" in the first Sunday of August/2003 in the Museum of Astronomy, MAST. O artigo trata do tema das Estações do Ano, explorando elementos da Ciência e da Arte como forma de motivar estudantes ou público de museus de ciência e tecnologia a compreendê-lo a partir de vivências culturais atuais e de outras épocas. A Física se junta à Astronomia para explicar o fenômeno, enquanto a Música e a Pintura possibilitam a imersão no tema em meio a muitas viagens à imaginação capazes de despertar emoções.Uma proposta didática é apresentada e justificada por consensos das muitas pesquisas na área de ensino-aprendizagem de ciências, desde os que se referem às persistentes concepções alternativas acerca das causas das mudanças observadas nas diferentes épocas do ano até à modelagem qualitativa de fenômenos que recorre a modelos pedagógicos tridimensionais. Tal proposta foi desenvolvida na atividade "Bate papo Hiperinteressante: As Quatro Estações, Ciência e Arte" realizada no primeiro domingo do mês de agosto de 2003 no Museu de Astronomia.

  14. Physicochemical properties of the modeled structure of astacin metalloprotease moulting enzyme NAS-36 and mapping the druggable allosteric space of Heamonchus contortus, Brugia malayi and Ceanorhabditis elegans via molecular dynamics simulation.

    PubMed

    Sharma, Om Prakash; Agrawal, Sonali; Kumar, M Suresh

    2013-12-01

    Nematodes represent the second largest phylum in the animal kingdom. It is the most abundant species (500,000) in the planet. It causes chronic, debilitating infections worldwide such as ascariasis, trichuriasis, hookworm, enterobiasis, strongyloidiasis, filariasis and trichinosis, among others. Molecular modeling tools can play an important role in the identification and structural investigation of molecular targets that can act as a vital candidate against filariasis. In this study, sequence analysis of NAS-36 from H. contortus (Heamonchus contortus), B. malayi (Brugia malayi) and C. elegans (Ceanorhabditis elegans) has been performed, in order to identify the conserved residues. Tertiary structure was developed for an insight into the molecular structure of the enzyme. Molecular Dynamics Simulation (MDS) studies have been carried out to analyze the stability and the physical properties of the proposed enzyme models in the H. contortus, B. malayi and C. elegans. Moreover, the drug binding sites have been mapped for inhibiting the function of NAS-36 enzyme. The molecular identity of this protease could eventually demonstrate how ex-sheathment is regulated, as well as provide a potential target of anthelmintics for the prevention of nematode infections.

  15. Physicochemical and antioxidant properties of Malaysian honeys produced by Apis cerana, Apis dorsata and Apis mellifera.

    PubMed

    Moniruzzaman, Mohammed; Khalil, Md Ibrahim; Sulaiman, Siti Amrah; Gan, Siew Hua

    2013-02-23

    The aim of the present study was to evaluate the physicochemical and antioxidant properties of Malaysian monofloral honey samples-acacia, pineapple and borneo honey-and compare them with tualang honey. Acacia and pineapple honey are produced by Apis mellifera bees while borneo and tualang honey are produced by Apis cerana and Apis dorsata bees, respectively. The physical parameters of honey, such as pH, moisture content, electrical conductivity (EC), total dissolved solids (TDS), color intensity, total sugar and apparent sucrose content, were measured. Hydroxymethylfurfural (HMF) was measured using high performance liquid chromatography, and a number of biochemical and antioxidant tests were performed to determine the antioxidant properties of the honey samples. Acacia honey was the most acidic (pH 3.53), whereas pineapple honey had the lowest moisture content (14.86%), indicating that both types of honey can resist microbial spoilage more effectively when compared to tualang honey (pH 3.80 and 17.53% moisture content). Acacia honey contained the highest EC (0.76 mS/cm), whereas borneo honey had the highest (377 ppm) TDS. The mean HMF content in Malaysian honey was 35.98 mg/kg. Tualang honey, which is amber color, had the highest color intensity (544.33 mAU). Acacia honey is the sweetest, and contained the highest concentration of total sugar, reducing sugar and apparent sucrose. Tualang honey had the highest concentration of phenolic compounds (352.73 ± 0.81 mg galic acid/kg), flavonoids (65.65 ± 0.74 mg catechin/kg), DPPH (59.89%), FRAP values (576.91 ± 0.64 μM Fe (II)/100 g) and protein content (4.83 ± 0.02 g/kg) as well as the lowest AEAC values (244.10 ± 5.24 mg/kg), indicating its strong antioxidant properties. Proline, an important amino acid that is present in honey was also measured in the present study and it was found at the highest concentration in pineapple honey. Several strong correlations were found among the biochemical and antioxidant

  16. Physicochemical and antioxidant properties of Malaysian honeys produced by Apis cerana, Apis dorsata and Apis mellifera

    PubMed Central

    2013-01-01

    Background The aim of the present study was to evaluate the physicochemical and antioxidant properties of Malaysian monofloral honey samples—acacia, pineapple and borneo honey—and compare them with tualang honey. Acacia and pineapple honey are produced by Apis mellifera bees while borneo and tualang honey are produced by Apis cerana and Apis dorsata bees, respectively. Methods The physical parameters of honey, such as pH, moisture content, electrical conductivity (EC), total dissolved solids (TDS), color intensity, total sugar and apparent sucrose content, were measured. Hydroxymethylfurfural (HMF) was measured using high performance liquid chromatography, and a number of biochemical and antioxidant tests were performed to determine the antioxidant properties of the honey samples. Results Acacia honey was the most acidic (pH 3.53), whereas pineapple honey had the lowest moisture content (14.86%), indicating that both types of honey can resist microbial spoilage more effectively when compared to tualang honey (pH 3.80 and 17.53% moisture content). Acacia honey contained the highest EC (0.76 mS/cm), whereas borneo honey had the highest (377 ppm) TDS. The mean HMF content in Malaysian honey was 35.98 mg/kg. Tualang honey, which is amber color, had the highest color intensity (544.33 mAU). Acacia honey is the sweetest, and contained the highest concentration of total sugar, reducing sugar and apparent sucrose. Tualang honey had the highest concentration of phenolic compounds (352.73 ± 0.81 mg galic acid/kg), flavonoids (65.65 ± 0.74 mg catechin/kg), DPPH (59.89%), FRAP values (576.91 ± 0.64 μM Fe (II)/100 g) and protein content (4.83 ± 0.02 g/kg) as well as the lowest AEAC values (244.10 ± 5.24 mg/kg), indicating its strong antioxidant properties. Proline, an important amino acid that is present in honey was also measured in the present study and it was found at the highest concentration in pineapple honey. Several strong correlations were found among the

  17. Laboratory and Airborne BRDF Analysis of Vegetation Leaves and Soil Samples

    NASA Technical Reports Server (NTRS)

    Georgiev, Georgi T.; Gatebe, Charles K.; Butler, James J.; King, Michael D.

    2008-01-01

    Laboratory-based Bidirectional Reflectance Distribution Function (BRDF) analysis of vegetation leaves, soil, and leaf litter samples is presented. The leaf litter and soil samples, numbered 1 and 2, were obtained from a site located in the savanna biome of South Africa (Skukuza: 25.0degS, 31.5degE). A third soil sample, number 3, was obtained from Etosha Pan, Namibia (19.20degS, 15.93degE, alt. 1100 m). In addition, BRDF of local fresh and dry leaves from tulip tree (Liriodendron tulipifera) and acacia tree (Acacia greggii) were studied. It is shown how the BRDF depends on the incident and scatter angles, sample size (i.e. crushed versus whole leaf,) soil samples fraction size, sample status (i.e. fresh versus dry leaves), vegetation species (poplar versus acacia), and vegetation s biochemical composition. As a demonstration of the application of the results of this study, airborne BRDF measurements acquired with NASA's Cloud Absorption Radiometer (CAR) over the same general site where the soil and leaf litter samples were obtained are compared to the laboratory results. Good agreement between laboratory and airborne measured BRDF is reported.

  18. High-Performance All-Solid-State Na-S Battery Enabled by Casting-Annealing Technology.

    PubMed

    Fan, Xiulin; Yue, Jie; Han, Fudong; Chen, Ji; Deng, Tao; Zhou, Xiuquan; Hou, Singyuk; Wang, Chunsheng

    2018-04-24

    Room-temperature all-solid-state Na-S batteries (ASNSBs) using sulfide solid electrolytes are a promising next-generation battery technology due to the high energy, enhanced safety, and earth abundant resources of both sodium and sulfur. Currently, the sulfide electrolyte ASNSBs are fabricated by a simple cold-pressing process leaving with high residential stress. Even worse, the large volume change of S/Na 2 S during charge/discharge cycles induces additional stress, seriously weakening the less-contacted interfaces among the solid electrolyte, active materials, and the electron conductive agent that are formed in the cold-pressing process. The high and continuous increase of the interface resistance hindered its practical application. Herein, we significantly reduce the interface resistance and eliminate the residential stress in Na 2 S cathodes by fabricating Na 2 S-Na 3 PS 4 -CMK-3 nanocomposites using melting-casting followed by stress-release annealing-precipitation process. The casting-annealing process guarantees the close contact between the Na 3 PS 4 solid electrolyte and the CMK-3 mesoporous carbon in mixed ionic/electronic conductive matrix, while the in situ precipitated Na 2 S active species from the solid electrolyte during the annealing process guarantees the interfacial contact among these three subcomponents without residential stress, which greatly reduces the interfacial resistance and enhances the electrochemical performance. The in situ synthesized Na 2 S-Na 3 PS 4 -CMK-3 composite cathode delivers a stable and highly reversible capacity of 810 mAh/g at 50 mA/g for 50 cycles at 60 °C. The present casting-annealing strategy should provide opportunities for the advancement of mechanically robust and high-performance next-generation ASNSBs.

  19. Termites create spatial structure and govern ecosystem function by affecting N2 fixation in an East African savanna.

    PubMed

    Fox-Dobbs, Kena; Doak, Daniel F; Brody, Alison K; Palmer, Todd M

    2010-05-01

    The mechanisms by which even the clearest of keystone or dominant species exert community-wide effects are only partially understood in most ecosystems. This is especially true when a species or guild influences community-wide interactions via changes in the abiotic landscape. Using stable isotope analyses, we show that subterranean termites in an East African savanna strongly influence a key ecosystem process: atmospheric nitrogen fixation by a monodominant tree species and its bacterial symbionts. Specifically, we applied the 15N natural abundance method in combination with other biogeochemical analyses to assess levels of nitrogen fixation by Acacia drepanolobium and its effects on co-occurring grasses and forbs in areas near and far from mounds and where ungulates were or were not excluded. We find that termites exert far stronger effects than do herbivores on nitrogen fixation. The percentage of nitrogen derived from fixation in Acacia drepanolobium trees is higher (55-80%) away from mounds vs. near mounds (40-50%). Mound soils have higher levels of plant available nitrogen, and Acacia drepanolobium may preferentially utilize soil-based nitrogen sources in lieu of fixed nitrogen when these sources are readily available near termite mounds. At the scale of the landscape, our models predict that termite/soil derived nitrogen sources influence >50% of the Acacia drepanolobium trees in our system. Further, the spatial extent of these effects combine with the spacing of termite mounds to create highly regular patterning in nitrogen fixation rates, resulting in marked habitat heterogeneity in an otherwise uniform landscape. In summary, we show that termite-associated effects on nitrogen processes are not only stronger than those of more apparent large herbivores in the same system, but also occur in a highly regular spatial pattern, potentially adding to their importance as drivers of community and ecosystem structure.

  20. Application of the photoacoustic method to the measurement of acetylene reduction by nitrogenase enzyme

    NASA Astrophysics Data System (ADS)

    Schramm, D. U.; Sthel, M. S.; Carneiro, L. O.; Franco, A. A.; Campos, A. C.; Vargas, H.

    2005-06-01

    Nitrogenase is an enzyme responsible for the reduction of the atmospheric N2 into NH4^+, which represents the key entry point of the molecular nitrogen into the biogeochemical cycle of nitrogen. This enzyme is present in the rhizobial bacteroids, which are symbionts in a Leguminosae plant (Acacia Holosericea), and also reduces acetylene into ethylene at the same rate as the nitrogen reduction. Therefore, a CO2 Laser Photoacoustic system was used for detecting and monitoring the ethylene emission by the nitrogenase activity, in the rhizobial symbionts in Acacia Holosericea, when they are confined in test tubes with acetylene at two different volumes (0.1 and 0.5 ml). Ethylene concentrations are also determined in the ppm range.