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Статті в журналах з теми "Ratios N:P":
1
Güsewell, Sabine. "N : P ratios in terrestrial plants: variation and functional significance." New Phytologist 164, no. 2 (September 20, 2004): 243–66. http://dx.doi.org/10.1111/j.1469-8137.2004.01192.x.
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Qaim, S. M., M. Ibn Majah, R. Wölfle, and B. Strohmaier. "Excitation functions and isomeric cross-section ratios for theZr90(n,p)90Ym,gandZr91(n,p)91Ym,gprocesses." Physical Review C 42, no. 1 (July 1, 1990): 363–67. http://dx.doi.org/10.1103/physrevc.42.363.
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Karchi, Zvi, and Daniel J. Cantliffe. "GROWTH OF CONTAINERIZED TRANSPLANTS SUPPLEMENTED WITH VARYING N AND P RATIOS." HortScience 26, no. 2 (February 1991): 101b—101. http://dx.doi.org/10.21273/hortsci.26.2.101b.
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Bakhshiyan, T. M. "Discussion of isomeric ratios in (p, n) and (d, 2n) reaction." Physics of Atomic Nuclei 79, no. 1 (January 2016): 38–43. http://dx.doi.org/10.1134/s1063778816010051.
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Simonne, E. H., J. N. McCrimmon, H. L. Scoggins-Mantero, and H. A. Mills. "254 KJELDAHL N:DUMAS N RATIOS FOR SELECTED CROPS." HortScience 29, no. 5 (May 1994): 466b—466. http://dx.doi.org/10.21273/hortsci.29.5.466b.
Анотація:
With recent advances in N analyzers, the Dumas method becomes more attractive as a replacement for Kjeldahl N. Kjeldahl N (K_N):Dumas N (D_N) ratios were determined for anthurium (A), orchid (O), fern (F) and turf (T). Dry tissues were ground to pass a 20-mesh seive. D_N was determined using 0.2 g of sample and a Leco FP-428. K_N was determined by digesting 0.4 g tissue with a CuO/TiO/K2SO4 catalyst and 10 mL H2SO4 at 450°C for 2 hr. Ammonium in the digest was assayed by colorimetry (Lachat analyzer). Overall (n=397 obs.), D_N was a good estimator of K_N: K_N = 0.90(p<0.01) D_N + 0.09(p=0.03), R2=0.93, over the 0.4-6.6 N range. K_N:D_N ratio was significantly (p<0.01) affected by plant type. Ratios of 0.85 for A, 0.92 for T, 0.99 for O, and 1.00 for F may be used to estimate K-N from D-N for the diagnosis of N nutrition, along with existing interpretative data.
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Kraus, H. T., S. L. Warren, G. J. Bjorkquist, A. W. Lowder, C. M. Tchir, and K. N. Walton. "Nitrogen:Phosphorus:Potassium Ratios Affect Production of Two Herbaceous Perennials." HortScience 46, no. 5 (May 2011): 776–83. http://dx.doi.org/10.21273/hortsci.46.5.776.
Анотація:
A series of experiments were undertaken to determine the effects of nitrogen (N), phosphorus (P), and potassium (K) concentrations and N:P:K ratio on flowering and vegetative growth of two herbaceous perennials, Hibiscus moscheutos L. (hibiscus) and Rudbeckia fulgida var. sullivantii Ait. ‘Goldsturm’ (rudbeckia). Plant growth and flowering of both hibiscus and rudbeckia were influenced by concentration and ratio of N, P, and K. When N was held constant at 100 mg·L−1, 4:1 N:K (25 mg·L−1 K) and 16:1 N:P (6.3 mg·L−1 P) were optimal for growing hibiscus, whereas higher K concentration (1:2 N:K, 200 mg·L−1 K) and lower P concentration (32:1 N:P, 3.1 mg·L−1 N) were required for optimal growth of rudbeckia. However, when holding N constant at 100 mg·L−1 and varying both P and K in the fertilizer solutions, higher P and K concentrations and a 2:1:2 (50 mg·L−1 P, 100 mg·L−1 K) N:P:K ratio best supported hibiscus growth, whereas 3:1:2 (33 mg·L−1 P, 66 mg·L−1 K) N:P:K was needed for growth of rudbeckia. Finally, when both N concentration and N:P:K ratio were altered, optimum growth of both hibiscus and rudbeckia was achieved at similar and lower P and K concentrations (25 mg·L−1 P and 50 mg·L−1 K) and 200 mg·L−1 N. An 8:1:2 N:P:K ratio was optimum for production of both hibiscus and rudbeckia, although 12:1:2 N:P:K (200 mg·L−1 N, 17 mg·L−1 P, 33 mg·L−1 K) produced similar growth of rudbeckia. Based on results of these two herbaceous perennials, it appears herbaceous perennials have N requirements similar to annual plants and P and K requirements similar to woody plants. Furthermore, the two herbaceous perennials used in this study required nutrients in the fertilizer solution at a higher N:P:K ratio than either annual or woody plants. Foliar concentrations of 2.2% N, 0.4% P, and 1.9% K were adequate for growth of hibiscus, whereas 2.4% N, 0.2% P, and 2.6% K were required to maximize growth of rudbeckia.
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Huang, Xiaolong, та Dunjiu Cai. "Systematics of Isomeric Cross-Section Ratios for (n,2n), (n, p), (n, α) Reactions at 14.5 MeV". Nuclear Science and Engineering 125, № 3 (березень 1997): 371–75. http://dx.doi.org/10.13182/nse97-a24282.
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Zhang, Lin, Lijuan Liu, Kaiwen Pan, Wei Li, Yanjie Wang, Mingrui Deng, Jiguo Xia, and Xu Yang. "Post-wildfire soil and plant foliar nutrient ratios and soil fungi : bacterial ratios in alpine meadows on the southeastern Qinghai-Tibet Plateau." International Journal of Wildland Fire 24, no. 7 (2015): 933. http://dx.doi.org/10.1071/wf14147.
Анотація:
Wildfire is increasingly considered as a common ecological phenomenon in grassland. However, little is known about its effects on soil and plant nutrient ratios, especially in alpine ecosystems where wildfires are common. In the present study, nutrient ratios of the post-wildfire surface soil (0–5 cm) and nine dominant plant species leaves, in addition to soil fungi : bacterial ratios (F : B ratios), were investigated in the alpine meadows on the south-eastern Qinghai-Tibet Plateau, approximately 20 months after a high-severity wildfire. The results indicated that the burned sites had lower soil nitrogen : phosphorus (N : P) and nitrogen : potassium (N : K) ratios compared with unburned sites. Moreover, foliar N concentrations were lower on burned than unburned sites, but foliar N : P ratios were not different. Compared with the unburned sites, greater foliar K concentrations and lower N : K ratios were observed in burned sites. The idiosyncratic responses of foliar nutrient ratios to wildfire varied greatly, especially N and related nutrient ratios with plant species. Soil F : B ratios were positively correlated with soil C : N and C : P ratios, whereas they were negatively correlated with soil N : P and N : K ratios. The results of the present study suggest that there is reduced supply capacity of soil N for plants relative to soil P and K in the post-fire alpine meadow, which could have potential ecological implications in this region.
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Buseva, Zh F., Sh G. Farahani, V. I. Razlutskij, E. A. Sysova, N. N. Maisak, K. V. Myagkova, and P. C. Frost. "Stoichiometry and planktonic communities structure in littoral and pelagic zones of two lakes with different trophic types in Belarus." Doklady of the National Academy of Sciences of Belarus 66, no. 6 (January 3, 2023): 595–604. http://dx.doi.org/10.29235/1561-8323-2022-66-6-595-604.
Анотація:
Stoichiometric C : N : P ratios were compared between primary producers in littoral and pelagic ecosystems of mesotrophic relatively shallow lake Obsterno and shallow macrophyte covered low trophic lake Nobisto from May to October over the next two years. Elemental seston ratios of lake Obsterno revealed smaller differences between littoral and pelagic zones in comparison with lake Nobisto in 2017. During the studied period, in the both lakes, the seston C : N and C : P ratios were higher than the Redfield ratio (106 : 16 : 1 C : N : P) on most dates and N : P was always more than 16. Pelagic C : P and N : P ratios in lake Obsterno were the highest in May in 2017, July and September in 2018 with significant differences between littoral and pelagic zones. N : P ratios decreased in October but there were no significant differences among habitats. In lake Nobisto in 2018, seston C : P and N : P ratios increased from May to July in littoral and pelagic zones but then decreased in September to October. Our research shows differences in stoichiometric ratios in littoral and pelagic zones of these two lakes, which indicates food quality (seston C : N : P ratios) differences for zooplankton species depending on season and location.
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Hawke, David J. "Soil P in a forested seabird colony: inventories, parent material contributions, and N : P stoichiometry." Soil Research 43, no. 8 (2005): 957. http://dx.doi.org/10.1071/sr05075.
Анотація:
Guano from breeding seabirds provides a large external source of nutrients to the soils of breeding colonies. However, little is known of guano P retention relative to N or the relative importance of guano and soil parent material as P sources. Soil profile N and P inventories (0–0.60 m, n = 4; 0–0.36 m, n = 1) and guano N and P concentrations were measured at a Westland petrel colony, and the parent material contributions of P were calculated using Ca, Al, Fe, Ti, and Zr as reference elements. Median inventories (0–0.60 m) were 1.49 kg N/m2 and 332 × 10–3 kg P/m2, the N result being similar to that from a seabird colony on peat soil where N retention was very low. Calculated parent material contributions were smallest (32–66% of soil P) when based on Ca and largest (47–102% of soil P) when based on Zr. Contributions were similar for Al, Fe, and Ti; Al (41–87% soil P) was selected for subsequent calculations. Regardless of the reference element, parent material therefore contributed a large part of soil P. Phosphorus in excess of parent material supply (Pexcess) was significantly correlated with soil C, implying that guano P is held primarily in organic form. The median soil N : P molar ratios were 9.6 : 1 based on total P and 11.2 : 1 based on Pexcess, compared with ratios for Westland petrel guano of 4.1 : 1 (when birds were consuming fisheries waste) and 16.4 : 1 (when fisheries waste was replaced by fish). The similarity between soil and guano N : P ratios implies that both N and P are lost from soil at similar rates, although volatilisation of N would enrich soil drainage water in P. Calculations using guano deposition rates from the literature yielded P residence times of 4–15 years (Pexcess) and 11–41 years (total P), consistent with a highly dynamic soil system.
Дисертації з теми "Ratios N:P":
1
Herda, Pavel. "Ekonomická analýza společnosti Budějovický Budvar, n. p." Master's thesis, Vysoká škola ekonomická v Praze, 2013. http://www.nusl.cz/ntk/nusl-198091.
Анотація:
This master's thesis deals with economic analysis of Budweiser Budvar, NC. The aim of this analysis is to assess the economic situation of this brewery since 2007 to 2012. The basic principles and methods of economic analysis are explained in the theoretical part. It means especially methods of financial analysis, such as analysis of the balance sheet and profit and loss statement, financial ratios, economic value added or overall models of vitality of business. The particular economic analysis is performed in the practical part. It includes market analysis and comparison to main competitors. The thesis shows that the profitability of brewery Budweiser Budvar, NC, is below-average, especially if related to figures of its key competitors, on the other hand it is very stable and liquid company.
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Meyer, Anne. "Étude expérimentale des réactions ¹³N(a,p)¹⁶O et ³⁰P(p,g)³¹S, et impact sur les abondances isotopiques extrêmes en ¹³C, ¹⁵N et ³⁰Si dans les grains pré-solaires." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS013.
Анотація:
On retrouve dans les météorites primitives des grains qui se sont condensés dans différents environnements stellaires et sont restés intacts après la formation du système solaire. L'identification du site d'origine de ces grains pré-solaires est effectuée grâce à la comparaison entre les abondances isotopiques mesurées et celles prédites par les modèles stellaires. Nous présentons dans ce manuscrit les analyses de deux expériences effectuées à l'installation ALTO avec le spectromètre magnétique split-pole, visant à réduire les incertitudes associées à deux réactions jouant un rôle dans la production des isotopes utilisés pour identifier les grains de novæ. Ces derniers sont caractérisés par des abondances extrêmes en ¹³C, ¹⁵N et ³⁰Si, mais la découverte dans certains grains d'isotopes caractéristiques de la nucléosynthèse dans les supernovæ à effondrement de coeur (CCSN) a remis en question cette origine. La première étude concerne l'impact du taux de la réaction ¹³N(a,p)¹⁶O sur les abondances en ¹³C prédites par de récents modèles de CCSN. Nous procédons à une ré-évaluation du taux de cette réaction en utilisant une méthode Monte Carlo pour obtenir des incertitudes statistiques. Les largeurs partielles alpha des états du noyau composé ¹⁷F sont déterminées en se basant sur les propriétés des états analogues du noyau miroir ¹⁷O qui ont été mesurées en utilisant la réaction de transfert alpha ¹³C(7Li,t)¹⁷O. Nous nous intéressons ensuite à la réaction ³⁰P(p,g)³¹S, qui est une des dernières réactions dont l'incertitude du taux a un impact important sur les prédictions faites par les modèles de novæ classiques, notamment des abondances en ³⁰Si. Pour réduire les incertitudes sur les propriétés spectroscopiques du noyau composé ³¹S, une étude de la réaction ³¹P(³He,t)³¹S a été effectuée. Les tritons et les protons de décroissance venant des états peuplés du ³¹S ont été détectés simultanément à l'aide du spectromètre et de détecteurs silicium à pistes. L'étude des corrélations angulaires proton est présentée et les rapports de branchement extraitsPrimitive meteorites contain several types of dust grains that condensed in different stellar environments and survived destruction in the early Solar System. The stellar sources where these presolar grains come from are identified through comparisons between measurements of isotopic abundances and predictions by stellar models. In this manuscript is presented a detailed analysis of two experiments performed at the ALTO facility, using the split-pole magnetic spectrometer, aiming at reducing the nuclear uncertainties associated to two reactions which rate uncertainty affects the synthesis of isotopes used to identify putative novae grains. These grains are characterised by extremely high ¹³C, ¹⁵N and ³⁰Si isotopic abundances, but isotopic signatures found in a few grains indicate also a possible core-collapse supernovae (CCSN) origin. We first study the impact of the ¹³N(a,p)¹⁶O reaction rate uncertainty on ¹³C abundances predicted by recent CCSN models. We perform a re-evaluation of this reaction rate using a Monte Carlo approach to obtain meaningful statistical uncertainties. Alpha partial widths of states in the ¹⁷F compound nucleus are determined using the spectroscopic informations of the analog states in the ¹⁷O mirror nucleus that were measured using the ¹³C(7Li,t)¹⁷O alpha-transfer reaction. We then study the ³⁰P(p,g)³¹S reaction, which is one of the few remaining reactions which rate uncertainty has a strong impact on classical novae model predictions, in particular for ³⁰Si abundances. To reduce the nuclear uncertainties associated to this reaction, we studied the ³¹P(³He,t)³¹S reaction. Triton and proton decays from the populated states in ³¹S were detected simultaneously using the spectrometer and silicon strip detectors. The study of the angular correlations of proton decays is presented and branching ratios are extracted
3
Lopes, Jéssica Costa. "Desempenho de reator de leito estruturado submetido à aeração intermitente, na remoção de nitrogênio e fósforo de esgoto sanitário utilizando glicerol fermentado como fonte de carbono." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-18072017-142829/.
Анотація:
Este trabalho buscou verificar a viabilidade do uso de fermentado de glicerol como fonte externa de carbono para a remoção biológica de nutrientes em um reator de leito estruturado, submetido à aeração intermitente (LEAI). O LEAI foi alimentado com efluente de reator UASB de bancada, usado no tratamento de esgoto sanitário. O reator LEAI possuía volume total de 12,3L e, devido às hastes cilíndricas verticais de espuma de poliuretano usadas como suporte para a biomassa, o volume útil foi de 8,6 L. Inicialmente, o reator foi operado sob aeração contínua com tempo de detenção hidráulica (TDH) de 24 horas e razão de recirculação de efluente igual a 3 para desenvolvimento de biomassa nitrificante no reator. Após a eficiência de nitrificação atingir 80%, o reator passou a ser operado com TDH de 12 horas e sob aeração intermitente, mantendo-se a razão de recirculação igual a 3. Foram então realizadas 4 fases em modo contínuo sob aeração intermitente (tempo de aeração/tempo sem aeração) de 2h/1h sem glicerol, 3h/1h sem glicerol, 2h/1h com glicerol, 3h/1h com glicerol. A adição de glicerol fermentado ocorreu somente durante os períodos não aerados. Em todas as fases, a DQO média efluente ao sistema variou entre 26±8 e 59±14 mg.L-1. Em relação à remoção de nitrogênio total (como NTK), verificou-se a baixa eficiência de remoção nas fases em que não houve a adição do fermentado, atingindo 49,6±13,5% (2h/1h) e 29,2±10,1% (3h/1h). Entretanto, nas fases em que houve a inserção do glicerol, as eficiências de remoção de N-total foram superiores, obtendo-se 64,9±21,6% (2h/1h) e 69,5±11,7% (3h/1h). Não foi observada remoção de fósforo em nenhuma das fases em que o reator foi operado com alimentação contínua. A fim de verificar a eficácia do fermentado de glicerol na remoção de N e P, o sistema foi modificado para que o reator LEAI operasse em bateladas sequenciais (RSB). Nessa etapa da pesquisa, observou-se o estabelecimento da comunidade acumuladora de fósforo no sistema, obtendo-se eficiência de remoção de fósforo de 56,1±8,5%. A eficiência de remoção de nitrogênio total também aumentou, atingindo 86,2±6,2%. Concluiu-se que o fermentado do glicerol apresenta potencial significativo para uso como fonte exógena de carbono no processo de remoção de fósforo e N-total. Concluiu-se também que, embora o glicerol fermentado contenha compostos favoráveis à remoção de fósforo em reatores de leito estruturado, a alimentação contínua do reator com aeração intermitente, não promove as condições ideais para o estabelecimento de processo estável de remoção de fósforo. No entanto, a elevada eficiência de oxidação de NTK, de remoção de matéria orgânica e de desnitrificação, aliadas à baixa produção sólida, mostram que o LEAI é uma alternativa interessante em comparação às tecnologias praticadas atualmente para pós-tratamento de efluentes de reatores anaeróbios. Contudo, quando a remoção de fósforo é necessária, a operação do reator em bateladas sequenciais é a alternativa viável.This work aimed to verify the viability of the use of fermented glycerol as an external carbon source for the nutrient biological removal in structured-bed reactor subjected to recirculation and intermittent aeration (SBRRIA). The SBRRIA was fed effluent from UASB reactor bench scale, used in the treatment of domestic sewage. The SBTTIA reactor had a total volume of 12.3L and, due to the vertical cylindrical strips of polyurethane foam used as biomass support, the useful volume was 8.6 L. Initially, the reactor was operated under continuous aeration with hydraulic retention time (HRT) of 24 hours and effluent recirculation ratio of 3 for the development of nitrifying biomass in the reactor. After the nitrification efficiency reach 80%, the reactor started to be operated at the HRT of 12 h under intermittent aeration, maintaining the recirculation ratio equal to 3. Four phases were then carried out continuously under intermittent aeration (aeration / time without aeration) of 2h/1h without glycerol, 3h/1h without glycerol, 2h/1h with glycerol, 3h/1h with glycerol. The addition of fermented glycerol occurred only during time without aeration. In all phases, the average COD effluent of the system ranged between 26±8 and 59±14 mg.L-1. Low removal efficiency of total nitrogen (as TKN) was verified in the phases without addition of the fermented glycerol, reaching 49.6±13.5% (2h/1h) and 29.2±10.1% (3h/1h). However, the efficiency of total nitrogen removal efficiency was higher when fermented glycerol was added during the non-aerated period, attaining 64.9±21.6% (2h/1h) and 69.5±11.7% (3h/1h). No phosphorus removal was observed in any of the previous phases in which the reactor was operated under continuous feeding. In order to verify the feasibility of fermented glycerol in the removal of N and P, the system was modified so that the LEAI reactor operated in sequential batch mode (SRB). At this stage of the research, the establishment of the phosphorus accumulating community in the system was observed and phosphorus removal efficiency attained 56.1±8.5%. The efficiency of total nitrogen removal also increased up to 86.2±6.2%. It was concluded that the fermented glycerol presents significant potential for use as an exogenous carbon source in the process of phosphorus and nitrogen removal. It can be also concluded that fixed bed reactors can remove phosphorus from wastewaters using fermented glycerol presenting compounds favorable to the development of phosphorus accumulating microorganisms (PAO). However, reactors subjected to continuous feeding and intermittent aeration do not promote good conditions for the establishment of stable phosphorus removal process. Nevertheless, the high efficiency of TKN oxidation, organic matter removal and denitrification, coupled with low solid production, show that SBRRIA is an interesting alternative for the post-treatment of anaerobic reactor effluents. However, when phosphorus removal is required, sequential batch reactor operation is the viable alternative.
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Carneiro, Rodrigo Braz. "Utilização de glicerol como fonte de carbono para desnitrificação e remoção biológica de fósforo em reator submetido à aeração intermitente." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-27052015-155302/.
Анотація:
Esse trabalho buscou avaliar a possibilidade de utilização do glicerol como fonte de carbono para a desnitrificação conjunta à remoção biológica de fósforo de um efluente sintético em um reator de fluxo contínuo submetido à aeração intermitente e com biomassa suspensa. O regime operacional do reator foi dividido em duas fases: a primeira visando somente a remoção de nitrato, testando diferentes relações Carbono/Nitrogênio (C/N) em Tempo de Detenção Hidráulica (TDH) de 4 horas; e a segunda visando a remoção de nitrato e fosfato com períodos de aeração e não aeração de 2 e 4 horas respectivamente, para uma relação Carbono/Fósforo de 10 ± 1. Na primeira fase operacional foram testadas 3 relações C/N, a saber: 1,2 ± 0,1; 1,5 ± 0,1 e 1,8 ± 0,2. Para a relação C/N de 1,8 ± 0,2 foi possível atingir uma maior eficiência de desnitrificação com uma maior estabilidade operacional - 91 ± 8%. Para a segunda fase de operação que apresentou relação C/N de 3,5 ± 0,2, a desnitrificação foi completa na maior parte do tempo com 99 ± 2% de eficiência de remoção de NOx (nitrato mais nitrito), indicando que a desnitrificação com glicerol é favorecida para relações C/N mais altas. Não foi evidenciado uma remoção biológica de fósforo expressiva (9 ± 12%), indicando que não houve desenvolvimento dos organismos acumuladores de fósforo (OAPs), uma vez que a liberação de fosfato durante a fase não aerada não ocorreu. Isso pode ser explicado pela falta de ácidos graxos voláteis (AGV), que seriam provenientes da degradação anaeróbia do glicerol, sendo a maior parte desse consumida na desnitrificação. Portanto, o teor de nitrato pode ter sido um fator de impedimento ao desenvolvimento dos OAPs. Pelos ensaios de microscopia óptica foi observado a presença de bactérias filamentosas semelhantes às do gênero Beggiatoa, que também podem ter consumido parte dos substratos da fermentação do glicerol. Por essas razões, sugere-se avaliar outras configurações de reatores de modo a promover uma efetiva fermentação do glicerol previamente ao sistema de remoção de fósforo.This study aimed to evaluate the feasibility of glycerol as a carbon source for denitrification and biological phosphorus removal of a synthetic wastewater in a continuous flow reactor with suspended biomass and subjected to intermittent aeration. The reactor operation was divided in two phases: the first one aimed only at removing nitrate, testing different C/N (Carbon/Nitrogen) ratios at an HRT (Hydraulic Retention Time) of 4 hours; and the second one aimed at the removal of nitrate and phosphate. During the second phase, the reactor was subjected to periods of aeration and non-aeration of 2 and 4 hours, respectively, for a C/P (Carbon/Phosphorus) ratio of 10 ± 1. In the first operational phase, three C/N ratios were tested, as follows: 1.2 ± 0.1; 1.5 ± 0.1 and 1.8 ± 0.2. For the C/N ratio of 1.8 ± 0.2, it was possible to achieve higher denitrification efficiency with greater operational stability - 91 ± 8%. For the second operational phase, with the C/N ratio of 3.5 ± 0.2, the denitrification was complete most of the time presenting 99 ± 2% of NOx (nitrate and nitrite) removal efficiency, indicating that the denitrification with glycerol is enhanced at higher C/N ratios. The biological phosphorus removal in this phase was not significant (12 ± 9%), indicating that there was no development of Phosphorus Accumulating Organisms (PAO), since the phosphate release during the anaerobic phase did not occur. This can be explained by the lack of Volatile Fatty Acids (VFA), which would come from the anaerobic degradation of glycerol that was consumed in denitrification. Therefore, the nitrate content may have been an interfering factor to the development of PAO. The optical microscopy analysis indicated the presence of filamentous bacteria similar to the genus Beggiatoa, which can also have consumed part of the substrates from the glycerol fermentation. For these reasons, it is suggested to evaluate other reactor configurations in order to promote the effective fermentation of glycerol previously to the phosphorus removal system.
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Smith, Samantha J. "Nutrient-diffusing substrate method capabilities in impacted streams with regard to light and substrate type." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1421925100.
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Duarte, Filipe Silveira. "Avaliação dos efeitos centrais da substância P free acid, dos inibidores de peptidases e das seqüências C- e N-Terminal da substância P no labirinto em cruz elevado em ratos." Florianópolis, SC, 2003. http://repositorio.ufsc.br/xmlui/handle/123456789/85687.
Анотація:
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas. Programa de Pós-Graduação em Farmacologia.Made available in DSpace on 2012-10-20T21:39:37Z (GMT). No. of bitstreams: 1 190352.pdf: 281352 bytes, checksum: b4a4269a93a10bd03c26a7e3343b8c16 (MD5)
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Marcilhac, Cyril. "Étude des conditions de culture d'un écosystème complexe microalgues / bactéries : application au développement d'un procédé d'extraction-valorisation des nutriments issus des digestats." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S078/document.
Анотація:
Les conditions de culture de microalgues autotrophes en système ouvert associant microalgues / bactéries ont été étudiées au cours de ce travail de thèse. L'objectif était de développer un procédé de valorisation des nutriments (N, P) contenus dans la phase liquide des digestats issus de méthanisation agricole. Dans un premier temps, une synthèse sur les filières de méthanisation suivi d'un état de l'art sur les microalgues et leurs conditions de culture ont permis de mettre en évidence les principaux paramètres d'influence spécifiques à l'influent étudié, tels que la coloration, et les interactions avec les processus de nitrification/dénitrification. Ainsi, dans le but de mieux comprendre les mécanismes et d'évaluer les impacts des paramètres principaux, un pilote de laboratoire composé de 6 réacteurs de 2,5 litres a été conçu et des analyses spécifiques ont été développées au laboratoire. A partir de ces outils, l'effet de la couleur et de la lumière sur la pénétration de la lumière et sur la croissance algale a été quantifié. Ensuite, l'influence du ratio N/P du milieu a été testée, ce qui a permis de mettre en exergue le stockage du phosphore par les microalgues, leur permettant de continuer leur croissance lorsque le phosphore du milieu est épuisé. Par la suite, le transfert du dioxyde de carbone et son impact sur la croissance des microalgues ont été étudiés. La productivité algale est fonction de la quantité de CO2 fournie à la culture et chute à 0 sans injection. Enfin, l'étude du temps de séjour des solides et de leur fréquence d'extraction a révélé que la nitrification-dénitrification est un mécanisme important d'élimination de l'azote dans une culture algale en continu et en système ouvert. Il peut même s'avérer prédominant par rapport à l'assimilation de l'azote par les microalgues dans certaines conditions. La proportion de chacun de ces processus peut néanmoins être contrôlée par ces paramètres. Ces expérimentations ont par ailleurs permis de mieux comprendre les interactions entre microalgues et bactéries nitrifiantes ainsi que la prédominance des genres d'algues en fonction des conditions de culture. Les microalgues sont de meilleures compétitrices sur le phosphore que les bactéries nitrifiantes. De plus, lorsque le phosphore n'est pas limitant, la nitrification est réduite en proportion de la productivité algale. En cas de limitation en phosphore et avec une faible lumière disponible, les genres d'algues qui se sont montrés dominants sont Scenedesmus sp. et Chlorella sp. Respectivement. Les essais expérimentaux ont été complétés par le développement ou l'adaptation de modèles biocinétiques capables de représenter la croissance algale et l'épuration assez fidèlement. A partir de cette modélisation, différentes configurations ont été simulées pour dimensionner un lagunage algal à haut rendement et ainsi mieux comprendre et apprécier la faisabilité d'une culture algale pour extraire les nutriments des digestatsThe culture conditions of autotrophic microalgae in open system associating microalgae/bacteria were studied in this thesis. The objective was to develop a process to valorize nutrients (N, P) contained in the liquid phase of digestate coming from agricultural methanization. First, a synthesis of anaerobic digestion process followed by a state of art on microalgae and their culture conditions allowed to highlight the main parameters specific to the studied influent, such as coloration, and the interactions with nitrification-denitrification processes. To better understand the mechanisms and study the impact of the main parameters, a laboratory-scale pilot composed of six 2.5L-reactors was designed and specific analyses were developed at the laboratory. With the help of those tools, effects of color and light on light penetration and on microalgae growth were quantified. Then, the study of the N:P ratio of the medium allowed to highlight the phosphorus storage by microalgae, allowing them to continue their growth while the phosphorus of the medium was depleted. Thereafter, the carbon dioxide transfer and its impact on microalgae growth were studied. The algal productivity is a function of the quantity of provided CO2 into the culture and fall to zero without injection. Finally, the study of solid retention time and extraction rate revealed that nitrification-denitrification is an important mechanism for nitrogen removal in a continuous algae culture in open system. This mechanism may even be predominant compared to nitrogen assimilation by microalgae under certain conditions. The proportion of each of these processes may still be controlled by these parameters. These experiments have also provided insight into the interactions between microalgae and nitrifying bacteria and the predominance of algae genera depending on culture conditions. Microalgae are better competitors on phosphorus than nitrifying bacteria. Furthermore, in non-limiting phosphorus conditions, nitrification is reduced in proportion to algal productivity. Scenedesmus and Chlorella proved to be dominant respectively when phosphorus and light are limiting. The experimental trials were completed by the development or the adaptation of biokinetic models able to represent quite accurately microalgae growth and nitrogen removal. From this model, different configurations were simulated to design high rate algal pond and assess the feasibility of the algal culture to extract nutrients from digestate
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Sparta', Roberta. "Indirect 2H(d,p)3H and 2H(d,n)3He fusion reactions measurement at energies relevant for Big Bang Nucleosynthesis." Doctoral thesis, Università di Catania, 2013. http://hdl.handle.net/10761/1429.
Анотація:
The work presented in this thesis is focused on the experimental study of the two deuterium burning channels 2H(d,p)3H and 2H(d,n)3He in the Big Bang Nucleosynthesis (BBN) astrophysical scenario.
In the beginning is presented this phase of the early universe and why the BBN model is still fine tuned with new results coming from observations and laboratory measurements. This model (if BBN is considered standard) can be adjusted such to have only a free parameter, the baryon to photon ratio of the universe eta at a certain time. Also the WMAP satellite results have been of great help to fix eta (and then all the others BBN numbers), but still persist some discrepancies, as for the lithium primordial abundances, between what is theoretically predicted and what is observed. The deuterium (and the reactions in which is involved) plays a key role in the evaluation of eta, thus for all BBN, so that is called the best baryometer.
Then is explained that the need of new cross sections (and reaction rates) measurements for astrophysics can not be satisfied. This is because of the problems given by their measurements in the laboratory, as the presence of Coulomb barrier (that makes cross sections exponentially decrease in the energy range of interest) and the electron screening effect.
For all these reasons the present measurements have been performed through the Trojan Horse Method (THM), an indirect method that allow to have a bare-nucleus cross section of the two-body reaction of astrophysical interest that is free of the Coulomb suppression. This is accomplished via the selection of the quasi-free mechanism in an appropriate three-body reaction, whose center-of-mass energy is greater than the Coulomb barrier.
Two experimental runs have been carried out at the Nuclear Physics Institute of the Academy of Science of Czech Republic, in Rez (Prague). In the first one, with a 17 MeV 3He beam (in which only 2H(d,p)3H has been measured) the presence of quasi-free mechanism events has been ascertained. The result obtained is fair but not good enough for the error reduction needed for astrophysics. Instead, to optimize the result in the region relecant for astrophysics, a the second run (where the 3He beam energy was 18 MeV) has been performed. In particular for the first time the technique of measuring one of the two-body reactions participant ejectile and the spectator particle, in this case a proton, instead of both the ejectiles. This has also allowed the measure of the 2H(d,n)3He reaction without the complexity of the neutron detection, so with a very good precision. All the off-line analysis done until the S-factor extraction is detailed explained, including the MPWBA analysis by Dr. S. Typel. Also the screening potential has been evaluated, obtaining a value of 13.2±1.8 eV for 2H(d,p)3H and 11.7±1.6 eV for 2H(d,n)3He, very close to the adiabatic limit, as expected. A pole invariance test has been provided comparing present results with previous TH data, where the 6Li was used as TH nucleus.
Reaction rates from present TH data for the two d+d channels, and from TH cross section of 3He(d,p)4He and 7Li(p,a)4He have been calculated. The new rates have been also compared with previous direct data compilations and with a new updated one that exclude questionable data sets. Using these new TH rates as input for the BBN code developed by prof. Bertulani, with eta fixed at the WMAP value, the primordial abundances have been obtained. These results are coherent with the whole model and will be soon compared with the observational results: a further analysis will provide stronger constraints on the values and a reduction of the involved uncertainties. This result reasserts that THM is a powerful tool for nuclear astrophysics and gives further validation to the BBN model.
9
Cunin, Bernard. "Etude et realisation d'un modulateur parametrique a double bande laterale fonctionnant a 10 ghz : application a la detection d'impulsions lumineuses breves." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13127.
Анотація:
Les proprietes d'un modulateur parametrique sont analysees. On montre que ce dispositif, constitue par la capacite variable d'une jonction pn pompee a 10 ghz, est caracterise par un gain de conversion, une impedance d'entree capacitive et un bruit interne tres reduit et qu'en consequence un systeme de detection optique, forme par une diode pin rapide couplee au convertisseur parametrique, presente un rapport signal a bruit superieur a celui des dispositifs de detection sans amplification interne habituellement utilises, au moins tant que la bande passante video est inferieure a 4 ghz. Enfin, on decrit une realisation pratique pour laquelle on a mesure un gain de conversion de 7db et une largeur a mi-hauteur de la reponse percussionnelle du modulateur seul voisine de 500 ps
10
Liu, Jia-You, and 劉家佑. "Fabrication and Characterization of GeSn n+/p Diodes with High JON/JOFF Ratios." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/86cwcf.
Анотація:
碩士國立臺灣大學
電子工程學研究所
107
Germanium-Tin (GeSn) alloys with a high carrier mobility are a promising channel material for next-generation CMOS technology. As the Sn fraction of GeSn alloysis higher than 8 ~ 11 %, GeSn becomes a direct-bandgap material, where more electrons would populate in the Γ band, leading to a smaller effective mass and higher electron mobility. Recent works on GeSn n-MOSFET shows the best ION/IOFF ratio is merely 10 ~ 10^3 A/A possibly due to the source/substrate or drain/substrate junction leakage. In this thesis, we focus on the material quality and carrier activation by phosphorus ion implant in strained or relaxed GeSn films to investigate the effects of strains in the epitaxial GeSn films on the n+/p junction leakage. Crystal quality will be degraded with severe Sn segregation after the ion implantation and the subsequent thermal or microwave annealing step. By X-ray diffraction, crystal quality after annealing can be evaluated. For sheet resistance and carrier activation, Hall measurements were performed. The results showed that MWA is better than RTA for carrier activation and crystal quality. To test the pn junction leakage, we fabricated Ge diodes as a baseline to evaluate the effects of process steps on the diode performance. The best JON/JOFF ratio achieved in Ge diode is 4.3 x 10^6 A/A. For GeSn diodes, by different process parameters such as implant doses, annealing temperature and microwave power, and GeSn thicknesses, it is suggested that the defects in the GeSn film would dominate the junction leakage. As the GeSn film is thicker, the leakage current is larger due to more associated defects by the strain relaxation. By MWA, the leakage current can be effectively suppressed. Furthermore, with a deep pn junction by a higher implant energy, the leakage current can be further suppressed. The record-high JON/JOFF ratios are 10^6 and 10^4 A/A for the strained and relaxed GeSn diodes, respectively.
Книги з теми "Ratios N:P":
1
Brêtas, Anilce de Araújo. Balanço eletrolítico estratégico na ração de suínos criados em clima quente. Brazil Publishing, 2021. http://dx.doi.org/10.31012/978-65-5861-318-3.
Анотація:
The effect of Dietary Electrolyte Balance (EB) in rations for growing and finished swine under high temperatures ambient was evaluated. Two hundred male castrated pigs with initial average 25,3±1.3 kg were allotted in completely randomized experimental design with five treatments T1 diet without supplemented electrolyte 191 mEq/kg; T2 (supl B) diet supplementd with sodium bicarbonate (NaHCO3) 250 mEq/kg; T3 (supl B+C) diet supplemented with (NaHCO3) and potassium chloride (KCl) 250 mEq/kg; T4 (supl B) diet supplemented with (NaHCO3) 300 mEq/kg; T5 (supl B+C) diet supplemented (NaHCO3) and (KCl) 300 mEq/kg and four replication and 10 pigs per experimental unit. The average weight of the animals was 68,8±3,4 kg. The performance parameters evaluated were the feed intake (FI), the daily gain (DG), finished weight (FW), nitrogen intake (NI), lysine intake (LI), efficiency of N utilization for weight gain (ENUWG), efficiency of L utilization for weight gain (ELUWG) and the gain:feed ration and physiologic parameters to respiratory frequency (RF) and rectal temperature (RT). Blood was colleted to measure serum concentration of Na, Cl and K. The average temperature was 29,65±1,80ºC with (RU) of 69,6±10,4%. The levels of EB decreased (P<0,05) the (FI) and improved (NI). The others performance parameters evaluated weren’t influenced by treatments (P>0,05). In the termination phase the supplementation with sodium bicarbonate and or potassium chloride with 250 or 300 mEq/kg can be used to correct electrolyte balance under heat stress.
2
Frels, Kelly, and Janet L. Horton. Documentation System for Teacher Improvement or Termination (N O L P E Monograph Series). 5th ed. Education Law Assn, 2003.
Частини книг з теми "Ratios N:P":
1
Aydin, Omer, Dilek Kanarya, Ummugulsum Yilmaz, and Cansu Ümran Tunç. "Determination of Optimum Ratio of Cationic Polymers and Small Interfering RNA with Agarose Gel Retardation Assay." In Methods in Molecular Biology, 117–28. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2010-6_7.
Анотація:
AbstractNanomaterials have aroused attention in the recent years for their high potential for gene delivery applications. Most of the nanoformulations used in gene delivery are positively charged to carry negatively charged oligonucleotides. However, excessive positively charged carriers are cytotoxic. Therefore, the complexed oligonucleotide/nanoparticles should be well-examined before the application. In that manner, agarose gel electrophoresis, which is a basic method utilized for separation, identification, and purification of nucleic acid molecules because of its poriferous nature, is one of the strategies to determine the most efficient complexation rate. When the electric field is applied, RNA fragments can migrate through anode due to the negatively charged phosphate backbone. Because RNA has a uniform mass/charge ratio, RNA molecules run in agarose gel proportional according to their size and molecular weight. In this chapter, the determination of complexation efficiency between cationic polymer carriers and small interfering RNA (siRNA) cargos by using agarose gel electrophoresis is described. siRNA/cationic polymer carrier complexes are placed in an electric field and the charged molecules move through the counter-charged electrodes due to the phenomenon of electrostatic attraction. Nucleic acid cargos are loaded to cationic carriers via the electrostatic interaction between positively charged amine groups (N) of the carrier and negatively charged phosphate groups (P) of RNA. The N/P ratio determines the loading efficiency of the cationic polymer carrier. In here, the determination of N/P ratio, where the most efficient complexation occurs, by exposure to the electric field with a gel retardation assay is explained.
2
Ullmann, J. L., J. Rapaport, P. W. Lisowski, R. C. Byrd, T. Carey, T. N. Taddeucci, J. McClelland, et al. "Ratio of Gamow-Teller to Fermi Strength Observed in 13,14C(p,n) at 492 and 590 Mev." In Spin Observables of Nuclear Probes, 245–50. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4613-0769-3_21.
3
Tiwari, Abhishek, and Shruti Aggarwal. "The Effect of Concentration Ratio and Number of P-N Thermocouples on Photovoltaic-Thermoelectric Hybrid Power Generation System." In Proceedings of the 7th International Conference on Advances in Energy Research, 1521–32. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5955-6_144.
4
Winkler, G., V. E. Lewis, T. B. Ryves, and M. Wagner. "The 238U(n,f) Cross Section and its Ratio to the 27Al(n,α)24Na and 56Fe(n,p)56Mn Cross Section in the 14 MeV Region." In Nuclear Data for Science and Technology, 514–17. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-58113-7_146.
5
Bianchi, Thomas S. "Organic Matter Cycling." In Biogeochemistry of Estuaries. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195160826.003.0017.
Анотація:
In this chapter the general processes involved in controlling production and transformation of organic matter will be discussed as well as some of the associated stoichiometric changes of a few key biological elements (e.g., C, N, P, S). Stoichiometry is defined as the mass balance of chemical reactions as they relate to the law of definite proportions and conservation of mass (Sterner and Elser, 2002). For example, if we examine the average atomic ratios of C, N, and P in phytoplankton we see a relatively consistent ratio of 106:16:1 in most marine species. This is perhaps the best example of applied stoichiometric principles in natural ecosystems and is derived from the classic work of Alfred C. Redfield (1890–1983) (Redfield, 1958; Redfield et al., 1963). More specifically, Redfield compared the ratios of C, N, and P of dissolved nutrients in marine waters to that of suspended marine particulate matter (seston) (essentially phytoplankton) and found straight lines with equal slopes (figure 8.1; Redfield et al., 1963). This relationship suggested that marine biota were critical in determining the chemistry of the world ocean, clearly one of the most important historical findings linking chemical and biological oceanography (Falkowski, 2000). Moreover, the Redfield ratio has been further validated with recent data using improved analytical techniques (Karl et al., 1993; Hoppema and Goeyens, 1999). Other work has shown that there are predictable deviations from the Redfield ratio across a freshwater to open ocean marine gradient (figure 8.2; Downing, 1997). For example, N-to-P ratios in estuaries have commonly been shown to be lower and/or higher than the predicted Redfield ratio because of denitrification and anthropogenic nutrient enrichment processes, respectively. Inputs of vascular plant organic matter (e.g., mangroves, salt marshes, seagrasses) to estuarine systems presents another problem in causing deviations of C:N:P from the Redfield ratio. Vascular plants have been shown to deviate from this ratio in part because of relatively high amounts of C and N compared to algae due to a higher abundance of structural support molecules (e.g., cellulose, lignin) and defense antiherbivory (secondary) compounds (e.g., tannins), respectively (Vitousek et al., 1988).
6
Brezonik, Patrick L., and William A. Arnold. "Nutrient Cycles and the Chemistry of Nitrogen and Phosphorus." In Water Chemistry, 805–50. 2nd ed. Oxford University PressNew York, 2022. http://dx.doi.org/10.1093/oso/9780197604700.003.0019.
Анотація:
Abstract This chapter discusses the chemistry of the nutrient elements, nitrogen and phosphorus, in the context of their cycles in the environment. Ways to portray nutrient cycles are described at molecular, landscape, and global scales. The chemical behavior of N and P forms is described, along with temporal trends and spatial patterns in aquatic systems. Cycling of N and P is linked by biotic stoichiometry—their elemental ratios in organisms—which for N:P is ~16:1 on an atom basis. Implications of this stoichiometry on N and P cycles are described. Nutrients are beneficial in that biological production is desirable in ecosystems, but excess N and P cause water quality problems. Reactor-based models to quantify loading-response relationships and chemical methods to remove nutrients from wastewater and control concentrations in lakes are described. Factors complicating nutrient analyses and a summary of methods for nutrient analyses conclude the chapter.
7
Bianchi, Thomas S. "Phosphorus and Silica Cycles." In Biogeochemistry of Estuaries. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195160826.003.0021.
Анотація:
Phosphorus (P) is one of the most well-studied nutrients in aquatic ecosystems because of its role in limiting primary production on ecological and geological timescales (van Capellen and Berner, 1989; Holland, 1994; Tyrell, 1999; van Cappellen and Ingall, 1996). Other key linkages to biological systems include the role of P as an essential constituent of genetic material (RNA and DNA) and cellular membranes (phospholipids), as well as in energy-transforming molecules (e.g., ATP, etc.). Consequently, marine P has received considerable attention in recent decades, with particular emphasis on source and sink terms in budgets (Froelich et al., 1982; Meybeck, 1982; Ruttenberg, 1993; Sutula et al., 2004). Excessive loading of N to estuarine waters can result in P limitation in systems that are generally considered to be N limited. In such cases where primary production is limited by P, N:P ratios are expected to exceed the Redfield value of 16:1 but can be replenished by sediment efflux of P due to redox changes. For example, after the initial N loading of a system there will be an increase in primary production, which can cause the system to become P limited. Then, the phytodetritus from these early stages of N loading can be remineralized in sediments resulting in anoxic conditions in surface sediments, which can then enhance P release from sediments to the overlying waters where primary production is once again enhanced. Evidence for the role of sediment-derived P on primary production in estuaries with high N loading has been shown to occur particularly in shallow water systems (Timmons and Price, 1996; Cerco and Seitzinger, 1997). On the other hand, many coastal areas have also been subjected to high P loading from anthropogenic sources, where in some cases inputs of P are 10 to 100 times greater than in preindustrial times (Caraco et al., 1993). In many cases, P and N loading to estuarine systems will occur simultaneously and decoupling or isolating their individual effects can be difficult (e.g., HELCOM, 2001). The cycling and availability of P in estuaries is largely dependent upon P speciation.
8
Olaleye, Adesola, Regina Mating, Tumelo Nkheloane, Tutu K. Samuel, and Tolu Yetunde Akande. "Wetland Health in Two Agro-Ecological Zones of Lesotho: Soil Physico-Chemical Properties, Nutrient Dynamics and Vegetation Isotopic N15." In Soil Science - Emerging Technologies, Global Perspectives and Applications [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.101836.
Анотація:
Monitoring is essential to evaluate the effects of wetland restoration projects. Assessments were carried-out after 6 years of restoration efforts on a wetland located in two agro-ecological zones (AEZ): the Mountains agro-ecological zone–Khalongla-lithunya (KHL) and the Foot Hills–Ha-Matela (HM). The former was under conservation and the latter non-conserved. Mini-pits were dug along transects for soil sampling. Runoff water was collected from installed piezometers into pre-rinsed plastic bottles with de-ionized water once a month for between 3 and 6 months. Soil and water samples were analyzed in the laboratory for Ca, Mg, K, Na, total nitrogen, and phosphorus, and soil samples were further analyzed for Cu, Fe, Zn, and Mn and vegetation isotopic N15. Water quality, soil organic matter (SOM), carbon pools, base cations, ratios (silt:clay & SOM:silt clay), texture, and N-15 isotopes were chosen as indicators. Results showed that base cations were significantly (p < 0.05) higher in the groundwater and soils of KHL wetlands compared with those from the HM. The soils of the KHL wetlands have higher (p < 0.05) clay, silt contents, SOM, and silt clay ratios compared with the HM. Furthermore, results of the N15 isotopes were between 2.52 and 2.93% (KHL) compared with 2.00 and 6.18% (HM). Similarly, the results of the δ13C showed significant negative values at KHL (28.13–28%) compared with HM (11.77–12.72%). The study concludes that after five years of rehabilitating the KHL wetlands, the soil indicators showed that restoration efforts are positive compared with the HM wetlands that are non-conserved.
9
Bianchi, Thomas S. "Characterization of Organic Matter." In Biogeochemistry of Estuaries. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195160826.003.0018.
Анотація:
In chapter 8, a general overview was provided on the dominant sources of organic matter in estuarine systems. In general, estuarine organic matter is derived from a multitude of natural and anthropogenic allochthonous and autochthonous sources that originate across a freshwater to seawater continuum. Knowledge of sources, reactivity, and fate of organic matter are critical in understanding the role of estuarine and coastal systems in global biogeochemical cycles (Simoneit, 1978; Hedges and Keil, 1995; Bianchi and Canuel, 2001). Due to a wide diversity of organic matter sources and the dynamic mixing that occurs in estuarine systems, it remains a significant challenge in determining the relative importance of these source inputs to biogeochemical cycling in the water column of sediments. Temporal and spatial variability in organic matter inputs adds further to the complexity in understanding these environments. In recent years there have been significant improvements in our ability to distinguish between organic matter sources in estuaries using tools such as elemental, isotopic (bulk and compound/class specific), and chemical biomarker methods. This chapter will provide a general overview of the biochemistry of dominant organic compounds in organic matter and the techniques used to distinguish them in estuarine systems. The abundance and ratios of important elements in biological cycles (e.g., C, H, N, O, S, and P) provide the basic foundation of information on organic matter cycling. For example, concentrations of total organic carbon (TOC) provide the most important indicator of organic matter since approximately 50% of most organic matter consists of C. As discussed in chapter 8, TOC in estuaries is derived from a broad spectrum of sources with very different structural properties and decay rates. Consequently, while TOC provides essential information on spatial and temporal dynamics of organic matter it lacks any specificity to source or age of the material. When bulk C information is combined with additional elemental information, as in the case of the C-to-N ratio, basic source information can be inferred about algal and terrestrial source materials (see review, Meyers, 1997). The broad range of C:N ratios across divergent sources of organic matter in the biosphere demonstrate how such a ratio can provide an initial proxy for determining source information.
10
Monson, Russell K., and Renée Mullen. "Plant Nutrient Relations." In Structure and Function of an Alpine Ecosystem. Oxford University Press, 2001. http://dx.doi.org/10.1093/oso/9780195117288.003.0017.
Анотація:
Alpine soils do not generally exhibit high levels of inorganic fertility, which is the result of inadequate mineralization of organic litter, a consequence of the cool, short alpine growing season (Rehder and Schäfer 1978; Gokceoglu and Rehder 1977; Rehder 1976a, 1976b; Fisk and Schmidt 1995; chapters 11, 12). Slow mineralization rates, in turn, result in a soil that is high in organic humus, and more likely than the soil of other ecosystems, to sequester and bind inorganic nutrients, especially N and P. Accordingly, alpine plants are exposed to a difficult situation in their efforts to obtain the inorganic ions required to support growth and reproduction. In accommodating the relative infertility of alpine soils, plants rely on a number of different traits, some of which are ubiquitous and some of which are more restricted in their distribution. Biomass allocation patterns favor high root:shoot ratios, increasing the potential for nutrient absorption by the roots relative to nutrient utilization by the shoot. Nutrient-use efficiencies (biomass produced per mass of senescent nutrient) tend to be high in alpine plants due to efficient resorption prior to leaf senescence. In several alpine growth forms, strict internal controls over seasonal phenology and growth (e.g., preformed buds and strongly enforced dormancy patterns) bring growth demands for nutrients more into balance with the limited supply provided by the soil. Luxury uptake and long-term storage during pulses of high nutrient availability provide plants with a means of bridging the gap between incongruent periods of high nutrient supply and high nutrient demand. Association of fungi with the roots of some alpine plants has the potential to enhance N and P acquisition. Finally, some alpine species can overcome the limitations imposed by scarce inorganic nutrient supplies through high rates of organic nutrient assimilation. It is the aim of this chapter to further consider each of these traits, with particular emphasis on their relationship to N and P acquisition. Topics concerning soil processes and their role in controlling nutrient availability have been covered elsewhere (chapter 8) and will not be repeated. Rather, this review focuses on nutrient relations from the plant’s perspective.
Тези доповідей конференцій з теми "Ratios N:P":
1
Tang, Hai, and Gui-zhong Liu. "Cross Effects of Organic Loading Rates and Substrate COD/N/P Ratios on Aerobic Granulation." In 2010 4th International Conference on Bioinformatics and Biomedical Engineering (iCBBE 2010). IEEE, 2010. http://dx.doi.org/10.1109/icbbe.2010.5517370.
2
Zhang Xiao-ling, Liu Xi-xiang, and Zhao Jian-qiang. "The effects of COD/P and N/P ratios on denitrifying phosphorus removal with nitrite as electron acceptor." In 2011 International Symposium on Water Resource and Environmental Protection (ISWREP). IEEE, 2011. http://dx.doi.org/10.1109/iswrep.2011.5893281.
3
Windisch, R., M. Kneissl, P. Kiesel, and G. H. Döhler. "Low voltage high contrast n-i-p-i based waveguide modulator." In The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/cleo_europe.1996.cwl1.
Анотація:
We have investigated an electroabsorptive n-i-p-i waveguide modulator based on the Franz-Keldysh effect (FKE) especially designed to operate with very low voltages. This is particularly interesting for high speed modulation and applications requiring integration with CMOS technology. The modulator operates at photon energies below the bandgap, and therefore the on-state absorption losses are very low. By applying a voltage between selective contacts to the n-t-p-i structure, the internal field can be changed within a wide range Due to the FKE an increase of the electric field leads to an increase of the absorption coefficient below the bandgap As the interaction length in a waveguide modulator is in the order of several hundred microns, absorption changes of a few 100cm−1 are sufficient to achieve contrast ratios of several orders of magnitude. In addition, the absorption changes due to the FKE extend over a broad wavelength range, which gives a good stability against thermal wavelength detuning and is also important for multiwavelength operation.
4
Braun, Pirmin, Niklas Hahn, Martin Hoefer, and Conrad Schecker. "Delegated Online Search." In Thirty-Second International Joint Conference on Artificial Intelligence {IJCAI-23}. California: International Joint Conferences on Artificial Intelligence Organization, 2023. http://dx.doi.org/10.24963/ijcai.2023/281.
Анотація:
In a delegation problem, a principal P with commitment power tries to pick one out of n options. Each option is drawn independently from a known distribution. Instead of inspecting the options herself, P delegates the information acquisition to a rational and self-interested agent A. After inspection, A proposes one of the options, and P can accept or reject. In this paper, we study a natural online variant of delegation, in which the agent searches through the options in an online fashion. How can we design algorithms for P that approximate the utility of her best option in hindsight? We show that P can obtain a Θ(1/n)-approximation and provide more fine-grained bounds independent of n based on two parameters. If the ratio of maximum and minimum utility for A is bounded by a factor α, we obtain an Ω(log log α / log α)-approximation algorithm and show that this is best possible. If P cannot distinguish options with the same value for herself, we show that ratios polynomial in 1/α cannot be avoided. If the utilities of P and A for each option are related by a factor β, we obtain an Ω(1 / log β)-approximation, and O(log log β / log β) is best possible.
5
De Jesus, Abi´lio M. P., M. Luisa Ruiz Ripoll, Norberto J. Gonc¸alves, and He´lder F. S. G. Pereira. "Probabilistic Fatigue Assessment of a Notched Detail Taking Into Account Mean Stress Effects." In ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/pvp2010-25056.
Анотація:
Probabilistic fatigue models are required to account conveniently for the several sources of uncertainty arising in the prediction procedures, such as the scatter in material behavior. In this paper, a recently proposed stress-based probabilistic model is assessed using fatigue data available for the P355NL1 steel (a pressure vessel steel). The referred probabilistic model is a log-Gumbel regression model, able to predict the probabilistic Wo¨hler field (P-S-N field), taking into account the mean stress (or stress R-ratio) effects. The parameters of the probabilistic model are identified using stress-life data derived for the P355NL1 steel, from smooth specimens, for three distinct stress R-ratios, namely R = −1, R = −0.5 and R = 0. The model requires a minimum of two test series with distinct stress R-ratios. Since data from three test series is available, extrapolations are performed to test the adequacy of the model to make extrapolations for stress R-ratios other than those used in the model parameters assessment. Finally, the probabilistic model is used to model the fatigue behavior of a notched plate made of P355NL1 steel. In particular, the P-S-N field of the plate is modeled and compared with available experimental data. Cyclic elastoplastic analysis of the plate is performed since plasticity at the notch root is developed.
6
Gevorgian, G. A., K. E. Kahramanian, R. B. Kostanian, and E. V. Kosheverskii. "Crystalline Air Cooled CW Laser." In The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/cleo_europe.1996.cwf40.
Анотація:
In order to reduce the weight-size dimensions of the lasers and apply their atmospheric low temperetures, it is often needed to use air cooled lasers, instead of traditional water cooled ones. It is known [1], that the heat exchange ratio when cooled diffusely by air, is approximately by two orders of magnitude lower than that for the liquid cooling Therefore, creation of air cooled CW lasers with pump power up to 3kW is one of the actual problems of modern laser techniques. The main problem in creation of similar lasers is to obtain high heat transmission ratios in cooling channels, which will ensure for the lasers working temperature regimes to be near the ones when cooled by liquids. For obtaining such high ratios of heat transmission the authors of this paper succeeded in developing of the turbulence of the flow in the channels with straight flow of the air with Reynolds number R e 0.875 = d 2 − d 1 v P m a x ( d 2 − d 1 ) 2 g k L ρ where d2-d1- is the hydraulic diameter of cooling channel, v-the kinematic viscosity of the air, Pmax-the maximal input pressure of the channel, g-free falling acceleration, k-hydraulic resistance ratio, L-the cooling channel's length, ρ- the air density. The principle of cooling is based on achieving an equality between the times of diffuse propagation of heated air molecule from the cooled object in the plane, perpendicular to the air flow and its running time from the channel's entrance along all its length. Inserting the number Re in the formula for calculating the heat exchange ratio [1] α = λ d 2 − d 1 { … } R e 0.875 P r n , we get its value for cooling channels of various dimensions and configurations, where λ- is the air heat conductivity, Pr - the Prandtl's number, n = 0.4 + 0.5 2 P r + 1 and figure brackets contain tabulated values of this formula and also constructive-technical parameters of the cooled channel very slightly influencing the heat exchange ratio's value.
7
McCallum, D. S., X. R. Huang, Arthur L. Smirl, D. Sun, and E. Towe. "Polarization Rotation Modulator in a Strained [110]-Oriented Multiple Quantum Well." In Spatial Light Modulators and Applications. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/slma.1995.ltua5.
Анотація:
Optical modulators with a high contrast ratio are desirable for use in optical information processing applications. Devices based on semiconductor multiple quantum wells are of particular interest because of the possibility of combining modulators with detectors and electronic components on a single substrate to make high-speed smart-pixel arrays. However, it is difficult to obtain large contrast ratios in conventional MQW modulators, which function by using the quantum confined Stark effect to modify the absorption coefficient of the MQW. For example, a typical p-i(MQW)-n modulator has a contrast ratio of 3:1 to 5:1, although contrast ratios as high as 10:1 have been obtained. Fabry-Perot cavities have been used to increase the contrast ratio to 100:1, but at the expense of optical bandwidth.
8
ARLAUSKIENĖ, Aušra, Viktorija GECAITĖ, and Danutė JABLONSKYTĖ-RAŠČĖ. "THE EVALUATION OF THE COMPATIBILITY OF CEREAL AND GREEN MANURE ON THE BASIS OF NUTRIENTS." In RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.039.
Анотація:
Research was carried out at the Lithuanian Research Centre for Agriculture and Forestry’s (LAMMC) Joniškėlis Experimental Station on a clay loam Endocalcari Endohypogleyic Cambisol. The study was aimed to explore the aboveground mass of perennial forage legumes: red clover (Trifolium pratense L.) and lucerne (Medicago sativa L.), and their mixtures with festulolium (x Festuliolium), used as green manure, qualitative parameters and compatibility with cereals on the basis of nutrients nitrogen (N), phosphorus (P) and potassium (K). The deficiency of other nutrients (P, K) and intensity of green manure mineralization can lead to N absorption. It has been determined that winter wheat takes one kg of N together with 0.2 kg P and 0.6 kg K. Spring wheat requires a similar amount of P but a higher amount of K. Average winter wheat grain yield can be 4.0 t ha-1 on a clay loam Cambisol in organic cropping system. NPK content – 134 kg ha-1 is needed for such productivity (grain + straw). This content is lower for spring winter growing. P:N and K:N ratios are more favourable in perennial forage legume mixture with festulolium, as compared to legume alone. To obtain grain yields of 4 t ha-1 of winter wheat and 3 t ha-1 of spring wheat in balanced organic crop rotation it is sufficient to apply 3.0 and 2.0 t ha-1 DM of pure legume mass as green manure. “Cut-and-carry” fertilisers do not satisfy the wheat demand for P.
9
Judkins, Roddie R., Timothy R. Armstrong, and Solomon D. Labinov. "A Universal Mathematical Model for a New Combined-Cycle, Fossil-Fuel Power System (LAJ Cycle): Part 1 — Static Model." In ASME Turbo Expo 2002: Power for Land, Sea, and Air. ASMEDC, 2002. http://dx.doi.org/10.1115/gt2002-30611.
Анотація:
A universal mathematical model (UMM) has been developed and applied to the LAJ (for Labinov, Armstrong, and Judkins) cycle, a new combined-cycle, fossil-fuel power system. The UMM includes static and dynamic models of the system. The static model allows for thermodynamic and thermochemical analyses of the basic system components (reformer, turbine, membrane separator, fuel cell, air compressor, heat exchanger, and other components) and the entire system. Equilibrium compositions of reforming products are defined by minimizing Gibbs free energy of the mixtures using the Lagrangian multiplier method. The dependence of the main system parameters on pressure (P), temperature (T), and water-to-methane molar ratios (N) at the steam reformer have been evaluated. For selected reforming parameters, viz., P = 4.0 MPa and T = 1200 K, the degree of methane conversion is near 95% with N = 5. However, in view of mass and size limitations on equipment, a lower value of N = 3 is preferred, in which case the degree of methane conversion is 88%. The dependence of the system static model parameters on N has been investigated, and economic characteristics of the model have been evaluated for an output power of 250 kW. It is shown that when, N = 3, the fuel cost contribution to overall electricity costs is 1 cent/kWh.
10
Lloyd, J. V., S. E. Rodgers, D. M. Siebert, F. Bochner, G. H. McIntosh, and M. James. "PRESYSTEMIC DEACETYLATION OF LOW DOSES OF ENTERIC COATED ASPIRIN IN A PIG MODEL." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643856.
Анотація:
The antithrombotic effect of aspirin might be enhanced if platelet cyclooxygenase could be inhibited in the portal ciculation while sparing cyclooxygenase in the systemic vascular endothelium. This might be achieved by modifying the dose and formulation to maximise presystemic aspirin clearance by the liver. To test this hypothesis low dose enteric coated aspirin (Astrix, 50mg single dose, lOOmg single dose and lOOmg daily for 1 week) was orally administered to pigs with permanent indwelling arterial and portal vein catheters. Plasma aspirin concentrations were measured by high performance liquid chromatography in blood obtained simultaneously from the artery and portal vein for 6 hours after dosage. Platelet aggregation and thromboxane generation were measured in 4 pigs before and after the lOOmg chronic dosage regimen. Aortic prostacyclin production was measured in aspirin treated (lOOmg daily for 1 week) and untreated pigs after sacrifice. After the 50mg single dose the arterial:portal areas under the plasma concentration versus time curve (AUC) ratio was 0.63±0.09 (n=6). In 3 pigs which received all 3 dosage regimens the arterial:portal AUC ratios were 0.48±0.05 after 50mg single dose, 0.52±0.02 after lOOmg single dose and 0.47+0.03 after lOOmg daily for 1 week. Platelet aggregation in response to sodium arachidonate (1.65mM) was completely abolished after chronic aspirin administration. Thromboxane production (pg/106 platelets) by this stimulus decreased from 536±117 before aspirin to 57±14 after aspirin (n=4; p=0.017). Aortic prostacyclin synthesis (ng/disc after 10 min incubation) was 1.66±0.28 (n=4) in untreated pigs and 0.97±0.25 (n=4) in treated pigs (p=0.06).With this slow release aspirin formulation there was substantial but incomplete clearance of aspirin by the liver. This may not be sufficient to spare cyclooxygenase in the systemic vessels from the effect of aspirin.
Звіти організацій з теми "Ratios N:P":
1
Tummala, Rohan, Andrew de Jesus, Natasha Tillett, Jeffrey Nelson, and Christine Lamey. Clinical and Socioeconomic Predictors of Palliative Care Utilization. University of Tennessee Health Science Center, January 2021. http://dx.doi.org/10.21007/com.lsp.2020.0006.
Анотація:
INTRODUCTION: Palliative care continues to gain recognition among primary care providers, as patients suffering from chronic conditions may benefit from use of this growing service. OBJECTIVES: This single-institution quality improvement study investigates the clinical characteristics and socioeconomic status (SES) of palliative care patients and identifies predictors of palliative care utilization. METHODS: Retrospective chart review was used to compare clinical and SES parameters for three groups of patients: (1) palliative care patients who attended at least one visit since the inception of the University Clinical Health Palliative Care Clinic in Memphis, TN in October 2018 (n = 61), (2) palliative care patients who did not attend any appointments (n = 19), and (3) a randomized group of age-matched primary care patients seen by one provider from May 2018 to May 2019 (n = 36). A Poisson regression model with backward conditional variable selection was used to determine predictors of palliative care utilization. RESULTS: Patients across the three care groups did not differ in demographic parameters. Compared to palliative care-referred non-users and primary care patients, palliative care patients tended to have lower health risk (p < 0.001). Palliative care patients did not differ from primary care patients in socioeconomic status but did differ in comorbidity distribution, having a higher prevalence of cancer (𝜒2 = 14.648, df = 7, p = 0.041). Chance of 10-year survival did not differ across risk categories for palliative care patients but was significantly lower for very high-risk compared to moderate-risk primary care patients (30% vs. 78%, p = 0.019). Significant predictors of palliative care use and their corresponding incidence rate ratios (IRR) were hospital referral (IRR = 1.471; p = 0.039), higher number of prescribed medications (IRR = 1.045; p = 0.003), lower Charlson Comorbidity Index (IRR = 0.907; p = 0.003), and lower systolic blood pressure (IRR = 0.989; p = 0.004). CONCLUSIONS: Patients who are expected to benefit from and of being high utilizers of palliative care may experience greater clinical benefit from earlier referral to this service.
2
Woods, Rachel, Alison Zhong, and Madelyn Vincent. Factors Associated with Influenza & Tdap Vaccine Uptake in Pregnant Patients at the UT Family Medicine Clinic in Memphis. University of Tennessee Health Science Center, 2021. http://dx.doi.org/10.21007/com.lsp.2020.0003.
Анотація:
INTRODUCTION: Given the increased risk for infections among pregnant patients and newborns, vaccination against influenza (>50,000,000 annual US cases affecting all ages) and pertussis (>15,000 annual US cases disproportionately affecting newborns) are recommended among pregnant patients in order to protect them and their babies via passive immunity to cover a newborn’s window of vaccine ineligibility. Though flu and Tdap vaccination rates among pregnant patients have been trending upwards nationally, there is still room for improvement to achieve optimal rates. OBJECTIVES: The primary objectives were to study factors that affect the vaccination rates at the University of Tennessee Family Medicine Clinic at Memphis (UTFMC-M), compare those rates with national pregnancy flu/Tdap vaccination rates, and to generate recommendations based off observed factors associated with vaccine uptake to improve flu/Tdap vaccination rates in UTFMC-M pregnant patients. METHODS: This was a retrospective chart review of UTFMC-M patients who were pregnant from September 1, 2019-April 24, 2020 (included 2019-2020 flu season) (n=465). Variables studied included demographic data (race, age, insurance), immunization history (vaccine status, history of physician encouragement), and prenatal history (parity, number of prenatal visits, trimester at first visit, high risk clinic (HRC) admittance status). Vaccination status was based on ACIP recommendations (Flu shot eligible = any gestational age; Tdap eligible = ≥27 weeks). Positive HRC admittance was noted for patients with ≥2 visits to the UTFMC-M HRC, a clinic that specializes in high risk pregnant patient care. RESULTS: The patient sample was predominantly black (84.3%) and insured by Medicaid programs (88%). Among eligible UTFMC-M pregnant patients, 50.1% were flu-vaccinated (n=465); 73.8% were Tdap-vaccinated (n=317); and 52.1% were Flu+Tdap-vaccinated (n=317). No significant associations were found between vaccine uptake and HRC status, parity, and age. However, statistically significant relationships were found between vaccine uptake and physician encouragement (positive relationship with flu shot: X2(1, N = 465) =131, p < 0.001, Tdap: X2 (6, N = 465) =476, p < 0.001), number of prenatal visits (flu shot group median 8 visits, Tdap group median 9 visits vs. unvaccinated group median 4 visits; p < 0.001), and early trimester age at first prenatal visit (X2(6, N = 465) =47.635 , p CONCLUSION: 2019-2020 UTFMC-M vaccination rates were on par with 2018-2019 US flu vaccine rates and higher than 2018-2019 US Tdap and Flu+Tdap rates. There were statistically significant relationships between vaccine uptake at UTFMC-M and physician encouragement, number of prenatal visits, and early trimester age at first prenatal visit but no significant relationships with UTFMC-M HRC admittance, parity, or age. Recommendations following from our observations to address further vaccine rate improvement include: continue vaccine encouragement, continue booking multiple visits (8 for flu, 9 for Tdap), prioritize Tdap vaccine higher for late trimester intake patients, and focus on flu vaccine encouragement and education.
3
Beal, Samuel, Matthew Bigl, and Charles Ramsey. Live-fire validation of command-detonation residues testing using a 60 mm IMX-104 munition. Engineer Research and Development Center (U.S.), August 2022. http://dx.doi.org/10.21079/11681/45266.
Анотація:
Command detonation (i.e., static firing) provides a method of testing munitions for their postdetonation residues early in the acquisition process. However, necessary modifications to the firing train and cartridge orientation raise uncertainty whether command detonation accurately represents residue deposition as it occurs during live-fire training. This study col-ected postdetonation residues from live-fired 60 mm IMX-104 mortar cartridges and then compared estimated energetic-compound deposition rates between live fire and prior command detonations of the same munition. Average live-fire deposition rates of IMX-104 compounds determined from 11 detonations were 3800 mg NTO (3-nitro-1,2,4-triazol-5-one), 34 mg DNAN (2,4-dinitroanisole), 12 mg RDX (1,3,5-Trinitroperhydro-1,3,5-Triazine), and 1.9 mg HMX (1,3,5,7-Tetranitro-1,3,5,7-Tetrazocane) per cartridge. Total live-fire residue deposition (mean ± standard deviation: 3800 ± 900 mg/cartridge) was not significantly different from command detonation using a representative fuze simulator (3800 ± 900 mg/cartridge, n = 7, p = 0.76) but was significantly different from command detonation using a simplified fuze simulator (2200 ± 500 mg/cartridge, n = 7, p < 0.01). While the dominant residue compound NTO was broadly similar between live fire and command detonation, the minor residue compounds RDX and DNAN were underestimated during command detonation by a factor of approximately three to seven.
4
Viswanathan, Meera, Jennifer Cook Middleton, Alison Stuebe, Nancy Berkman, Alison N. Goulding, Skyler McLaurin-Jiang, Andrea B. Dotson, et al. Maternal, Fetal, and Child Outcomes of Mental Health Treatments in Women: A Systematic Review of Perinatal Pharmacologic Interventions. Agency for Healthcare Research and Quality (AHRQ), April 2021. http://dx.doi.org/10.23970/ahrqepccer236.
Анотація:
Background. Untreated maternal mental health disorders can have devastating sequelae for the mother and child. For women who are currently or planning to become pregnant or are breastfeeding, a critical question is whether the benefits of treating psychiatric illness with pharmacologic interventions outweigh the harms for mother and child. Methods. We conducted a systematic review to assess the benefits and harms of pharmacologic interventions compared with placebo, no treatment, or other pharmacologic interventions for pregnant and postpartum women with mental health disorders. We searched four databases and other sources for evidence available from inception through June 5, 2020 and surveilled the literature through March 2, 2021; dually screened the results; and analyzed eligible studies. We included studies of pregnant, postpartum, or reproductive-age women with a new or preexisting diagnosis of a mental health disorder treated with pharmacotherapy; we excluded psychotherapy. Eligible comparators included women with the disorder but no pharmacotherapy or women who discontinued the pharmacotherapy before pregnancy. Results. A total of 164 studies (168 articles) met eligibility criteria. Brexanolone for depression onset in the third trimester or in the postpartum period probably improves depressive symptoms at 30 days (least square mean difference in the Hamilton Rating Scale for Depression, -2.6; p=0.02; N=209) when compared with placebo. Sertraline for postpartum depression may improve response (calculated relative risk [RR], 2.24; 95% confidence interval [CI], 0.95 to 5.24; N=36), remission (calculated RR, 2.51; 95% CI, 0.94 to 6.70; N=36), and depressive symptoms (p-values ranging from 0.01 to 0.05) when compared with placebo. Discontinuing use of mood stabilizers during pregnancy may increase recurrence (adjusted hazard ratio [AHR], 2.2; 95% CI, 1.2 to 4.2; N=89) and reduce time to recurrence of mood disorders (2 vs. 28 weeks, AHR, 12.1; 95% CI, 1.6 to 91; N=26) for bipolar disorder when compared with continued use. Brexanolone for depression onset in the third trimester or in the postpartum period may increase the risk of sedation or somnolence, leading to dose interruption or reduction when compared with placebo (5% vs. 0%). More than 95 percent of studies reporting on harms were observational in design and unable to fully account for confounding. These studies suggested some associations between benzodiazepine exposure before conception and ectopic pregnancy; between specific antidepressants during pregnancy and adverse maternal outcomes such as postpartum hemorrhage, preeclampsia, and spontaneous abortion, and child outcomes such as respiratory issues, low Apgar scores, persistent pulmonary hypertension of the newborn, depression in children, and autism spectrum disorder; between quetiapine or olanzapine and gestational diabetes; and between benzodiazepine and neonatal intensive care admissions. Causality cannot be inferred from these studies. We found insufficient evidence on benefits and harms from comparative effectiveness studies, with one exception: one study suggested a higher risk of overall congenital anomalies (adjusted RR [ARR], 1.85; 95% CI, 1.23 to 2.78; N=2,608) and cardiac anomalies (ARR, 2.25; 95% CI, 1.17 to 4.34; N=2,608) for lithium compared with lamotrigine during first- trimester exposure. Conclusions. Few studies have been conducted in pregnant and postpartum women on the benefits of pharmacotherapy; many studies report on harms but are of low quality. The limited evidence available is consistent with some benefit, and some studies suggested increased adverse events. However, because these studies could not rule out underlying disease severity as the cause of the association, the causal link between the exposure and adverse events is unclear. Patients and clinicians need to make an informed, collaborative decision on treatment choices.
5
Papavassiliou, V. Measurement of the cross-section ratio {sigma}{sub n}/{sigma}{sub p} in inelastic muon-nucleon scattering at very low x and Q{sup 2}. Office of Scientific and Technical Information (OSTI), November 1992. http://dx.doi.org/10.2172/10103825.
6
Kotwal, A. V. Structure functions and structure function ratio F{sub 2}{sup n}/F{sub 2}{sup p} at low X{sub Bj} and Q{sup 2} in inelastic muon scattering. Office of Scientific and Technical Information (OSTI), August 1994. http://dx.doi.org/10.2172/10183502.
7
Borch, Thomas, Yitzhak Hadar, and Tamara Polubesova. Environmental fate of antiepileptic drugs and their metabolites: Biodegradation, complexation, and photodegradation. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7597927.bard.
Анотація:
Many pharmaceutical compounds are active at very low doses, and a portion of them regularly enters municipal sewage systems and wastewater-treatment plants following use, where they often do not fully degrade. Two such compounds, CBZ and LTG, have been detected in wastewater effluents, surface waters, drinking water, and irrigation water, where they pose a risk to the environment and the food supply. These compounds are expected to interact with organic matter in the environment, but little is known about the effect of such interactions on their environmental fate and transport. The original objectives of our research, as defined in the approved proposal, were to: Determine the rates, mechanisms and products of photodegradation of LTG, CBZ and selected metabolites in waters exposed to near UV light, and the influence of DOM type and binding processes on photodegradation. Determine the potential and pathways for biodegradation of LTG, CBZ and selected metabolites using a white rot fungus (Pleurotusostreatus) and ADP, and reveal the effect of DOM complexation on these processes. Reveal the major mechanisms of binding of LTG, CBZ and selected metabolites to DOM and soil in the presence of DOM, and evaluate the effect of this binding on their photodegradation and/or biodegradation. We determined that LTG undergoes relatively slow photodegradation when exposed to UV light, and that pH affects each of LTG’s ability to absorb UV light, the efficiency of the resulting reaction, and the identities of LTG’sphotoproducts (t½ = 230 to 500 h during summer at latitude 40 °N). We observed that LTG’sphotodegradation is enhanced in the presence of DOM, and hypothesized that LTG undergoes direct reactions with DOM components through nucleophilic substitution reactions. In combination, these data suggest that LTG’s fate and transport in surface waters are controlled by environmental conditions that vary with time and location, potentially affecting the environment and irrigation waters. We determined that P. ostreatusgrows faster in a rich liquid medium (glucose peptone) than on a natural lignocellulosic substrate (cotton stalks) under SSF conditions, but that the overall CBZ removal rate was similar in both media. Different and more varied transformation products formed in the solid state culture, and we hypothesized that CBZ degradation would proceed further when P. ostreatusand the ᵉⁿᶻʸᵐᵃᵗⁱᶜ ᵖʳᵒᶠⁱˡᵉ ʷᵉʳᵉ ᵗᵘⁿᵉᵈ ᵗᵒ ˡⁱᵍⁿⁱⁿ ᵈᵉᵍʳᵃᵈᵃᵗⁱᵒⁿ. ᵂᵉ ᵒᵇˢᵉʳᵛᵉᵈ ¹⁴C⁻Cᴼ2 ʳᵉˡᵉᵃˢᵉ ʷʰᵉⁿ ¹⁴C⁻ᶜᵃʳᵇᵒⁿʸˡ⁻ labeled CBZ was used as the substrate in the solid state culture (17.4% of the initial radioactivity after 63 days of incubation), but could not conclude that mineralization had occurred. In comparison, we determined that LTG does not degrade in agricultural soils irrigated with treated wastewater, but that P. ostreatusremoves up to 70% of LTG in a glucose peptone medium. We detected various metabolites, including N-oxides and glycosides, but are still working to determine the degradation pathway. In combination, these data suggest that P. ostreatuscould be an innovative and effective tool for CBZ and LTG remediation in the environment and in wastewater used for irrigation. In batch experiments, we determined that the sorption of LTG, CBZ and selected metabolites to agricultural soils was governed mainly by SOM levels. In lysimeter experiments, we also observed LTG and CBZ accumulation in top soil layers enriched with organic matter. However, we detected CBZ and one of its metabolites in rain-fed wheat previously irrigated with treated wastewater, suggesting that their sorption was reversible, and indicating the potential for plant uptake and leaching. Finally, we used macroscale analyses (including adsorption/desorption trials and resin-based separations) with molecular- level characterization by FT-ICR MS to demonstrate the adsorptive fractionation of DOM from composted biosolids by mineral soil. This suggests that changes in soil and organic matter types will influence the extent of LTG and CBZ sorption to agricultural soils, as well as the potential for plant uptake and leaching.
8
McPhedran, R., K. Patel, B. Toombs, P. Menon, M. Patel, J. Disson, K. Porter, A. John, and A. Rayner. Food allergen communication in businesses feasibility trial. Food Standards Agency, March 2021. http://dx.doi.org/10.46756/sci.fsa.tpf160.
Анотація:
Background: Clear allergen communication in food business operators (FBOs) has been shown to have a positive impact on customers’ perceptions of businesses (Barnett et al., 2013). However, the precise size and nature of this effect is not known: there is a paucity of quantitative evidence in this area, particularly in the form of randomised controlled trials (RCTs). The Food Standards Agency (FSA), in collaboration with Kantar’s Behavioural Practice, conducted a feasibility trial to investigate whether a randomised cluster trial – involving the proactive communication of allergen information at the point of sale in FBOs – is feasible in the United Kingdom (UK). Objectives: The trial sought to establish: ease of recruitments of businesses into trials; customer response rates for in-store outcome surveys; fidelity of intervention delivery by FBO staff; sensitivity of outcome survey measures to change; and appropriateness of the chosen analytical approach. Method: Following a recruitment phase – in which one of fourteen multinational FBOs was successfully recruited – the execution of the feasibility trial involved a quasi-randomised matched-pairs clustered experiment. Each of the FBO’s ten participating branches underwent pair-wise matching, with similarity of branches judged according to four criteria: Food Hygiene Rating Scheme (FHRS) score, average weekly footfall, number of staff and customer satisfaction rating. The allocation ratio for this trial was 1:1: one branch in each pair was assigned to the treatment group by a representative from the FBO, while the other continued to operate in accordance with their standard operating procedure. As a business-based feasibility trial, customers at participating branches throughout the fieldwork period were automatically enrolled in the trial. The trial was single-blind: customers at treatment branches were not aware that they were receiving an intervention. All customers who visited participating branches throughout the fieldwork period were asked to complete a short in-store survey on a tablet affixed in branches. This survey contained four outcome measures which operationalised customers’: perceptions of food safety in the FBO; trust in the FBO; self-reported confidence to ask for allergen information in future visits; and overall satisfaction with their visit. Results: Fieldwork was conducted from the 3 – 20 March 2020, with cessation occurring prematurely due to the closure of outlets following the proliferation of COVID-19. n=177 participants took part in the trial across the ten branches; however, response rates (which ranged between 0.1 - 0.8%) were likely also adversely affected by COVID-19. Intervention fidelity was an issue in this study: while compliance with delivery of the intervention was relatively high in treatment branches (78.9%), erroneous delivery in control branches was also common (46.2%). Survey data were analysed using random-intercept multilevel linear regression models (due to the nesting of customers within branches). Despite the trial’s modest sample size, there was some evidence to suggest that the intervention had a positive effect for those suffering from allergies/intolerances for the ‘trust’ (β = 1.288, p<0.01) and ‘satisfaction’ (β = 0.945, p<0.01) outcome variables. Due to singularity within the fitted linear models, hierarchical Bayes models were used to corroborate the size of these interactions. Conclusions: The results of this trial suggest that a fully powered clustered RCT would likely be feasible in the UK. In this case, the primary challenge in the execution of the trial was the recruitment of FBOs: despite high levels of initial interest from four chains, only one took part. However, it is likely that the proliferation of COVID-19 adversely impacted chain participation – two other FBOs withdrew during branch eligibility assessment and selection, citing COVID-19 as a barrier. COVID-19 also likely lowered the on-site survey response rate: a significant negative Pearson correlation was observed between daily survey completions and COVID-19 cases in the UK, highlighting a likely relationship between the two. Limitations: The trial was quasi-random: selection of branches, pair matching and allocation to treatment/control groups were not systematically conducted. These processes were undertaken by a representative from the FBO’s Safety and Quality Assurance team (with oversight from Kantar representatives on pair matching), as a result of the chain’s internal operational restrictions.
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Lines, Lisa M., Florence K. L. Tangka, Sonja Hoover, and Sujha Subramanian. People with Colorectal Cancer in SEER-Medicare: Part D Uptake, Costs, and Outcomes. RTI Press, May 2020. http://dx.doi.org/10.3768/rtipress.2020.rr.0037.2005.
Анотація:
Limited information exists about enrollment in Part D prescription coverage by Medicare beneficiaries with cancer. Part D coverage may increase access to medicines. This study evaluated patterns of Part D uptake and costs and assessed the effects of coverage on hospitalizations and emergency department (ED) use among people with colorectal cancer (CRC). We analyzed Surveillance, Epidemiology, and End Results (SEER)–Medicare linked data on fee-for-service (FFS) Medicare beneficiaries with at least 36 months of follow-up who were diagnosed with CRC at any point from January 2007 through December 2010, and a matched cohort of beneficiaries without cancer. Dual (Medicare/Medicaid) enrollees were excluded because they are automatically enrolled in Part D. Among beneficiaries with CRC (n=12,774), 39 percent had complete Part D coverage, defined as coverage in the diagnosis year and 2 subsequent years; the rate was 38 percent in the matched comparison cohort (P=.119). Among those with complete Part D coverage, there was no significant difference in annual prescription drug costs between people with CRC ($3,157, 95% confidence interval [CI]: $3,098–$3,216) and without ($3,113, 95% CI: $3,054–$3,172). Among people with CRC, odds of ED use ranged from unchanged to marginally higher for those with no or partial Part D coverage, (adjusted odds ratio: 1.09, 95% CI: 1.00–1.18), compared with those with complete Part D coverage. Lack of continuous Part D coverage was associated with more ED use among Medicare FFS beneficiaries with CRC in 2007–2013. Among people with Part D coverage, prescription drug costs varied little between those with CRC and matched beneficiaries without cancer.
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NTP Technical Report on the Toxicity Studies of p-Toluenesulfonamide (CAS No. 70-55-3) Administered in Feed to F344/N Rats, F344/NTac Rats, and B6C3F1/N Mice. NIEHS, June 2019. http://dx.doi.org/10.22427/ntp-tox-88.