Regulation of Apoplastic NH4+ Concentration in Leaves of Oilseed Rape1

Regulation of apoplastic NH4+ concentration in leaves of oilseed rape (Brassica napus L.) was studied using a vacuum-infiltration technique that allowed controlled manipulations of the apoplastic solution. In leaves infiltrated with NH4+-free solution, the apoplastic NH4+ concentration returned in less than 1.5 min to the preinfiltration level of 0.8 mm. Infiltrated 15NH4+ was rapidly diluted by 14NH4+/14NH3 effluxed from the cell. The exchange rate of 15N/14N over the apoplast due to combined 14N efflux from the symplast and 15N influx from the apoplastic solution was 29.4 ��mol g���1 fresh weight h���1 between 0 and 5 min after infiltration. The net uptake of NH4+ into the leaf cells increased linearly with apoplastic NH4+ concentrations between 2 and 10 mm and could be partially inhibited by the channel inhibitors La3+ and tetraethylammonium and by Na+ and K+. When apoplastic pH increased from 5.0 to 8.0, the steady-state apoplastic NH4+ concentration decreased from 1.0 to 0.3 mm. Increasing temperature increased the rate of NH4+ net uptake and reduced the apoplastic steady-state NH4+ concentration. We conclude that the apoplastic solution in leaves of oilseed rape constitutes a highly dynamic NH4+ pool.

An apical permeability barrier to NH3/NH4+ in isolated, perfused colonic crypts.

Fermentation of nonabsorbed nutrients in the colon generates high concentrations of NH3/NH4+ in the colonic lumen. NH3 is a small, lipophilic neutral weak base that readily permeates almost all cell membranes, whereas its conjugate weak acid NH4+ generally crosses membranes much more slowly. It is not known how colonocytes maintain intracellular pH in the unusual acid-base environment of the colon, where permeant acid-base products of fermentation exist in high concentration. To address this issue, we hand dissected and perfused single, isolated crypts from rabbit proximal colon, adapting techniques from renal-tubule microperfusion. Crypt perfusion permits control of solutions at the apical (luminal) and basolateral (serosal) surfaces of crypt cells. We assessed apical- vs. basolateral-membrane transport of NH3/NH4+ by using fluorescent dyes and digital imaging to monitor intracellular pH of microvacuolated crypt cells as well as luminal pH. We found that, although the basolateral membranes have normal NH3/NH4+ permeability properties, there is no evidence for transport of either NH3 or NH4+ across the apical borders of these crypt cells. Disaggregating luminal mucus did not increase the transport of NH3/NH4+ across the apical border. We conclude that, compared to the basolateral membrane, the apical border of crypt colonocytes has a very low permeability-area product for NH3/NH4+. This barrier may represent an important adaptation for the survival of crypt cells in the environment of the colon.

Le de��cret du 13 novembre et l'Acade��mie des beaux-arts : suivi du rapport de M. de Nieuwerkerke, surintendant des beaux-arts, du de��cret du 13 novembre, de la protestation de l'Acade��mie, et de la re��ponse de S. Exc. le mare��chal Vaillant, ministre de la maison de l'Empereur et des beaux-arts /

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Kalendario anual, y gu��a para el cumplimiento de los d��as, y a��os de los Exc. Sres. Grandes de Espa��a, asi residentes en la Corte, como fuera de ella, para este a��o 1775 /

Mode of access: Internet.

Al Rey Nuestro Se��or por el respetable conducto del Exc.mo. S.R. Conde de Floridablanca ... ofrece ... el Presidente de la Real Chancilleria y de la Real Junta de Polic��a ... baxo si inmediata protecci��n el manifiesto o memoria de las desgracias ocurridas en el da 25 de Febrero de este a��o de 1788 ... /

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Comentario de D. Joseph Isidoro Morales al Exc. Se��or D. Joseph de Mazarredo sobre la ense��anza de su hija /

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Discursos lei��dos ante la Real Academia de la Historia en la recepcio��n pu��blica del exc. Sr. D. Enrique de Aguilera y Gamboa, Marque��s de cerralbo en 31 de mayo de 1908.

Mode of access: Internet.

Catalogue de la biblioth��que de Son Exc. M. Le comte D. Boutourlin.

The present library is the second collected by Count Buturlin. The first, of which a catalog was issued at Paris in 1805, was destroyed at the burning of Moscow in 1812.

Reciprocal N ((NH4+)-N-15 or (NO3-)-N-15) transfer between nonN(2)-fixing Eucalyptus maculata and N-2-fixing Casuarina cunninghamiana linked by the ectomycorrhizal fungus Pisolithus sp.

Two-way N transfers mediated by Pisolithus sp. were examined by excluding root contact and supplying (NH4+)-N-15 or (NO3-)-N-15 to 6-month-old Eucalyptus maculata or Casuarina cunninghamiana grown in two-chambered-pots separated by 37 m screens. Mycorrhizal colonization was 35% in Eucalyptus and 66% in Casuarina (c. 29% N-2-fixation). Using an environmental scanning electron microscope, living hyphae were observed to interconnect Eucalyptus and Casuarina. Biomass and N accumulation was greatest in nodulated mycorrhizal Casuarina/mycorrhizal Eucalyptus pairs, less in nonnodulated mycorrhizal Casuarina/mycorrhizal Eucalyptus pairs, and least in nonnodulated nonmycorrhizal Casuarina/nonmycorrhizal Eucalyptus pairs. In nonnodulated mycorrhizal pairs, N transfers to Eucalyptus or to Casuarina were similar (2.4-4.1 mg per plant in either direction) and were 2.6-4.0 times greater than in nonnodulated nonmycorrhizal pairs. In nodulated mycorrhizal pairs, N transfers were greater to Eucalyptus (5-7 times) and to Casuarina (12-18 times) than in nonnodulated mycorrhizal pairs. Net transfer to Eucalyptus or to Casuarina was low in both nonnodulated nonmycorrhizal (< 0.7 mg per plant) and nonnodulated mycorrhizal pairs (< 1.1 mg per plant). In nodulated mycorrhizal pairs, net transfer to Casuarina was 26.0 mg per plant. The amount and direction of two-way mycorrhiza-mediated N transfer was increased by the presence of Pisolithus sp. and Frankia, resulting in a net N transfer from low-N-demanding Eucalyptus to high-N-demanding Casuarina.

Nodulated N-2-fixing Casuarina cunninghamiana is the sink for net N transfer from non-N-2-fixing Eucalyptus maculata via an ectomycorrhizal fungus Pisolithus sp using (NH4+)-N-15 or (NO3-)-N-15 supplied as ammonium nitrate

To determine the effects of nitrogen source on rates of net N transfer between plants connected by a common mycorrhizal network, we measured transfer of N supplied as (NH4NO3)-N-15-N-14 or (NH4NO3)-N-14-N-15 in three Casuarina/Eucalyptus treatments interconnected by a Pisolithus sp. The treatments were nonnodulated nonmycorrhizal/nonmycorrhizal; nonnodulated mycorrhizal/mycorrhizal; and nodulated mycorrhizal/mycorrhizal. Mycorrhization was 67% in Eucalyptus and 36% in Casuarina. N-2 fixation supplied 38% of the N in Casuarina. Biomass, N and N-15 contents were lowest in nonmycorrhizal plants and greatest in plants in the nodulated/mycorrhizal treatment. Nitrogen transfer was enhanced by mycorrhization and by nodulation, and was greater when N was supplied as (NH4+)-N-15 than (NO3-)-N-15. Nitrogen transfer rates were lowest in the nonmycorrhizal treatment for either N-15 source, and greatest in the nodulated, mycorrhizal treatment. Transfer was greater to Casuarina than to Eucalyptus and where ammonium rather than nitrate was the N source. Irrespective of N-15 source and of whether Casuarina or Eucalyptus was the N sink, net N transfer was low and was similar in both nonnodulated treatments. However, when Casuarina was the N sink in the nodulated, mycorrhizal treatment, net N transfer was much greater with (NH4+)-N-15 than with (NO3-)-N-15. High N demand by Casuarina resulted in greater net N transfer from the less N-demanding Eucalyptus. Net transfer of N from a non-N-2-fixing to an N-2-fixing plant may reflect the very high N demand of N-2-fixing species.

Historical global map of NH4+ and NO3- application in synthetic nitrogen fertilizer, link to NetCDF files

This paper provides a method for constructing a new historical global nitrogen fertilizer application map (0.5�� �� 0.5�� resolution) for the period 1961-2010 based on country-specific information from Food and Agriculture Organization statistics (FAOSTAT) and various global datasets. This new map incorporates the fraction of NH+4 (and NONO-3) in N fertilizer inputs by utilizing fertilizer species information in FAOSTAT, in which species can be categorized as NH+4 and/or NO-3-forming N fertilizers. During data processing, we applied a statistical data imputation method for the missing data (19 % of national N fertilizer consumption) in FAOSTAT. The multiple imputation method enabled us to fill gaps in the time-series data using plausible values using covariates information (year, population, GDP, and crop area). After the imputation, we downscaled the national consumption data to a gridded cropland map. Also, we applied the multiple imputation method to the available chemical fertilizer species consumption, allowing for the estimation of the NH+4/NO-3 ratio in national fertilizer consumption. In this study, the synthetic N fertilizer inputs in 2000 showed a general consistency with the existing N fertilizer map (Potter et al., 2010, doi:10.1175/2009EI288.1) in relation to the ranges of N fertilizer inputs. Globally, the estimated N fertilizer inputs based on the sum of filled data increased from 15 Tg-N to 110 Tg-N during 1961-2010. On the other hand, the global NO-3 input started to decline after the late 1980s and the fraction of NO-3 in global N fertilizer decreased consistently from 35 % to 13 % over a 50-year period. NH+4 based fertilizers are dominant in most countries; however, the NH+4/NO-3 ratio in N fertilizer inputs shows clear differences temporally and geographically. This new map can be utilized as an input data to global model studies and bring new insights for the assessment of historical terrestrial N cycling changes.

Growth and characterization of anodic Films on InP in KOH and (NH4)2S

The current-voltage characteristics of InP were investigated in (NH4)2S and KOH electrolytes. In both solutions, the observation of current peaks in the cyclic voltammetric curves was attributed to the growth of passivating films. The relationship between the peak currents and the scan rates suggests that the film formation process is diffusion controlled in both cases. The film thickness required to inhibit current flow was found to be much lower on samples anodized in the sulphide solution. Focused ion beam (FIB) secondary electron images of the surface films show that film cracking of the type reported previously for films grown in (NH4)2S is also observed for films grown in KOH. X-ray and electron diffraction measurements indicate the presence of In2O3 and InPO4 in films grown in KOH and In2S3 in films grown in (NH4)2S.

Utiliza����o da macroalga Ulva lactuca linnaeus na redu����o de nutrientes (NH4+,NO3- e PO4-2) provenientes da carcinicultura

Dentre as macroalgas capazes de absorver altas concentra����es de N e P dissolvidos na ��gua, destaca-se a Chlorophyta Ulva lactuca, bastante adapt��vel e resistente ��s adversidades ambientais, como grandes varia����es de temperatura, salinidade, mat��ria org��nica e metais pesados. Trata-se tamb��m de uma esp��cie bastante comum nas ��reas intertidais do litoral norte-riograndense. Devido a suas caracter��sticas ecol��gicas, fisiol��gicas e nutricionais, foi avaliado nesse estudo, o seu potencial como biofiltro na redu����o de NH4+, NO3- e PO4-2, tanto em condi����es controladas como tamb��m em um viveiro de camar��o. No experimento laboratorial, foram utilizados quatro aqu��rios de vidro de 30 x 20 x 20cm com 10L de ��gua, sendo tr��s aqu��rios experimentais contendo 20g de U. lactuca e um controle. O acr��scimo de biomassa foi de 2,92g (22,92 �� 6,29g; p < 0,05) em rela����o ao in��culo inicial de 20g, sob temperatura (28,50 �� 0,58��C), salinidade (35,00 �� 0,00 ), pH (8,26 �� 0,02) e luz constante (250 &#956;mol.m2s-1). O crescimento positivo (1,78 �� 4,38%dia-1; p < 0,05), juntamente com a alta efici��ncia de absor����o de am��nio (83%; p < 0,001), nitrato (83%; p < 0,001) e ortofosfato (53%; p < 0,001), demonstrou que, nessas condi����es, a Ulva lactuca absorveu os nutrientes e aumentou sua biomassa. J�� no experimento de campo, realizado na fazenda TECNAR��O, situada no munic��pio de Arez/RN (06�� 11 40 Latitude Sul, e 35�� 09 37 Longitude Oeste), foram utilizadas tr��s gaiolas de PVC, posicionadas a 12cm da superf��cie da ��gua, cada uma com dimens��es de aproximadamente 59 x 59 x 15cm, onde foram colocadas 200g de U. lactuca. O ganho de biomassa de 3g (203,00 �� 41,02g; p < 0,001) foi muito semelhante ��s condi����es controladas, demonstrando a adaptabilidade da esp��cie em condi����es ambientais vari��veis, onde, apesar da temperatura pouco vari��vel (27,45 �� 0,64��C), houve progressiva diminui����o de salinidade (25 - 15 ), devido ao per��odo de fortes chuvas (34,70 �� 23,78mm). Somado a isso, foram observados v��rios fatores biol��gicos interferindo no viveiro, como a presen��a de ep��fitas, organismos endof��ticos, fouling e a herbivoria por parte dos pr��prios camar��es. Houve aumento nas concentra����es de NH4+ (4,36 �� 1,69 &#956;mol.L-1), NO3- (0,17 �� 0,25&#956;mol.L-1) e PO4-2 (0,41 �� 0,13&#956;mol.L-1), coincidindo com o crescimento da esp��cie at�� a terceira semana. Todos os par��metros ambientais analisados, assim como a biomassa e a Taxa de Crescimento Relativo (TCR), obtidos no campo, apresentaram varia����es altamente significativas (p < 0,001). As correla����es observadas entre biomasa e NH4+ (r = 0,82; p < 0,001) e entre biomassa e PO4-2 (r = 0,87; p < 0,001), indicam que esta esp��cie �� capaz de ter um crescimento satisfat��rio nas condi����es eutr��ficas de um viveiro de camar��o, sendo poss��vel seu uso como biofiltro.

Utiliza����o da macroalga Ulva lactuca linnaeus na redu����o de nutrientes (NH4+,NO3- e PO4-2) provenientes da carcinicultura

Dentre as macroalgas capazes de absorver altas concentra����es de N e P dissolvidos na ��gua, destaca-se a Chlorophyta Ulva lactuca, bastante adapt��vel e resistente ��s adversidades ambientais, como grandes varia����es de temperatura, salinidade, mat��ria org��nica e metais pesados. Trata-se tamb��m de uma esp��cie bastante comum nas ��reas intertidais do litoral norte-riograndense. Devido a suas caracter��sticas ecol��gicas, fisiol��gicas e nutricionais, foi avaliado nesse estudo, o seu potencial como biofiltro na redu����o de NH4+, NO3- e PO4-2, tanto em condi����es controladas como tamb��m em um viveiro de camar��o. No experimento laboratorial, foram utilizados quatro aqu��rios de vidro de 30 x 20 x 20cm com 10L de ��gua, sendo tr��s aqu��rios experimentais contendo 20g de U. lactuca e um controle. O acr��scimo de biomassa foi de 2,92g (22,92 �� 6,29g; p < 0,05) em rela����o ao in��culo inicial de 20g, sob temperatura (28,50 �� 0,58��C), salinidade (35,00 �� 0,00 ), pH (8,26 �� 0,02) e luz constante (250 &#956;mol.m2s-1). O crescimento positivo (1,78 �� 4,38%dia-1; p < 0,05), juntamente com a alta efici��ncia de absor����o de am��nio (83%; p < 0,001), nitrato (83%; p < 0,001) e ortofosfato (53%; p < 0,001), demonstrou que, nessas condi����es, a Ulva lactuca absorveu os nutrientes e aumentou sua biomassa. J�� no experimento de campo, realizado na fazenda TECNAR��O, situada no munic��pio de Arez/RN (06�� 11 40 Latitude Sul, e 35�� 09 37 Longitude Oeste), foram utilizadas tr��s gaiolas de PVC, posicionadas a 12cm da superf��cie da ��gua, cada uma com dimens��es de aproximadamente 59 x 59 x 15cm, onde foram colocadas 200g de U. lactuca. O ganho de biomassa de 3g (203,00 �� 41,02g; p < 0,001) foi muito semelhante ��s condi����es controladas, demonstrando a adaptabilidade da esp��cie em condi����es ambientais vari��veis, onde, apesar da temperatura pouco vari��vel (27,45 �� 0,64��C), houve progressiva diminui����o de salinidade (25 - 15 ), devido ao per��odo de fortes chuvas (34,70 �� 23,78mm). Somado a isso, foram observados v��rios fatores biol��gicos interferindo no viveiro, como a presen��a de ep��fitas, organismos endof��ticos, fouling e a herbivoria por parte dos pr��prios camar��es. Houve aumento nas concentra����es de NH4+ (4,36 �� 1,69 &#956;mol.L-1), NO3- (0,17 �� 0,25&#956;mol.L-1) e PO4-2 (0,41 �� 0,13&#956;mol.L-1), coincidindo com o crescimento da esp��cie at�� a terceira semana. Todos os par��metros ambientais analisados, assim como a biomassa e a Taxa de Crescimento Relativo (TCR), obtidos no campo, apresentaram varia����es altamente significativas (p < 0,001). As correla����es observadas entre biomasa e NH4+ (r = 0,82; p < 0,001) e entre biomassa e PO4-2 (r = 0,87; p < 0,001), indicam que esta esp��cie �� capaz de ter um crescimento satisfat��rio nas condi����es eutr��ficas de um viveiro de camar��o, sendo poss��vel seu uso como biofiltro.

Development Of Egg Pc/cholesterol/��-tocopherol Liposomes With Ionic Gradients To Deliver Ropivacaine.

Ropivacaine (RVC) is an aminoamide local anesthetic widely used in surgical procedures. Studies with RVC encapsulated in liposomes and complexed in cyclodextrins have shown good results, but in order to use RVC for lengthy procedures and during the postoperative period, a still more prolonged anesthetic effect is required. This study therefore aimed to provide extended RVC release and increased upload using modified liposomes. Three types of vesicles were studied: (i) large multilamellar vesicle (LMV), (ii) large multivesicular vesicle (LMVV) and (iii) large unilamellar vesicle (LUV), prepared with egg phosphatidylcholine/cholesterol/��-tocopherol (4:3:0.07���mol%) at pH 7.4. Ionic gradient liposomes (inside: pH 5.5, pH 5.5���+���(NH4)2SO4 and pH 7.4���+���(NH4)2SO4) were prepared and showed improved RVC loading, compared to conventional liposomes (inside: pH 7.4). An high-performance liquid chromatography analytical method was validated for RVC quantification. The liposomes were characterized in terms of their size, zeta potential, polydispersion, morphology, RVC encapsulation efficiency (EE(%)) and in vitro RVC release. LMVV liposomes provided better performance than LMV or LUV. The best formulations were prepared using pH 5.5 (LMVV 5.5in) or pH 7.4 with 250���mM (NH4)2SO4 in the inner aqueous core (LMVV 7.4in���+���ammonium sulfate), enabling encapsulation of as much as 2% RVC, with high uptake (EE(%) ���70%) and sustained release (���25���h). The encapsulation of RVC in ionic gradient liposomes significantly extended the duration of release of the anesthetic, showing that this strategy could be a viable means of promoting longer-term anesthesia during surgical procedures and during the postoperative period.