Carbon-13 turnover in 'roxo de valinhos' fig trees

The aim of this study was to assess carbon-13 turnover in different organs of the fig tree, 'Roxo de Valinhos' cultivar. The experiment was carried out in an orchard at School of Agronomical Sciences, FCA/UNESP, Botucatu Campus, State of São Paulo, Brazil. The main photosynthetically active leaf was previously determined based on gas exchanges by means of an open portable photosynthesis system, IRGA. That leaf was placed in a chamber where the enriched gas injection occurred. The leaf enrichment time was 30 minutes. Treatments were constituted of seven fig trees removed from the soil after: 6; 24; 48; 72; 120; 168 and 360 hours of enrichment using (13)C, and their parts were sectioned into: apical bud, young leaves, adult leaves (photosynthetically active), lateral sprouts, fruits, and branch. The results allowed the establishment of the carbon-13 metabolism sequence in the studied parts: Young leaves > Fruits > Sprouts > Adult leaves > Apical bud > branch > Labeled leaf. 'Roxo de Valinhos' fig trees, had (13)C turnover of 24 hours and carbon-13 half-time shorter than 11 hours.

Renovação do carbono-13 em figueiras 'Roxo de Valinhos'

O objetivo do trabalho foi determinar a taxa de renovação do carbono-13 (turnover), dos diferentes órgãos da figueira 'Roxo de Valinhos'. O experimento foi conduzido no pomar da Faculdade de Ciências Agronômicas, FCA/UNESP, Câmpus de Botucatu-SP. Determinou-se previamente, através das trocas gasosas com um medidor aberto portátil de fotossíntese, IRGA, a principal folha fotossinteticamente ativa. Essa folha foi colocada em uma câmara onde ocorreu a injeção do gás enriquecido. O tempo de enriquecimento da folha foi de 30 minutos. Os tratamentos foram constituídos por sete plantas de figueira, que foram retiradas do solo após: 6; 24; 48; 72; 120; 168 e 360 horas do enriquecimento com 13C, e suas partes seccionadas em: gema apical, folha jovem, folhas adultas (fotossinteticamente ativas), brotações laterais, frutos e ramo. Os resultados obtidos permitiram o estabelecimento da sequência de metabolização do carbono-13 nas partições estudadas: Folhas novas > Frutos > Brotações > Folhas Adultas > Gema Apical > Ramo > Folha marcada. Plantas de figueira 'Roxo de Valinhos' apresentam reciclagem do 13C de 24 horas e um tempo de meia-vida de duração do carbono-13 inferior a 11 horas.

Implante autólogo de células mononucleares provenientes de medula óssea notratamento de tendinites induzidas experimentalmente em equinos: avaliação a longo prazo - 120 dias

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Utilização do carbono-13 como marcador na partição de fotoassimilados em figueira

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The etiology of liver damage imparts cytokines transforming growth factor beta1 or interleukin-13 as driving forces in fibrogenesis

It is unknown whether transforming growth factor beta1 (TGF-beta1) signaling uniformly participates in fibrogenic chronic liver diseases, irrespective of the underlying origin, or if other cytokines such as interleukin (IL)-13 share in fibrogenesis (e.g., due to regulatory effects on type I pro-collagen expression). TGF-beta1 signaling events were scored in 396 liver tissue samples from patients with diverse chronic liver diseases, including hepatitis B virus (HBV), hepatitis C virus (HCV), Schistosoma japonicum infection, and steatosis/steatohepatitis. Phospho-Smad2 staining correlated significantly with fibrotic stage in patients with HBV infection (n = 112, P < 0.001) and steatosis/steatohepatitis (n = 120, P < 0.01), but not in patients with HCV infection (n = 77, P > 0.05). In tissue with HBx protein expression, phospho-Smad2 was detectable, suggesting a functional link between viral protein expression and TGF-beta1 signaling. For IL-13, immunostaining correlated with fibrotic stage in patients with HCV infection and steatosis/steatohepatitis. IL-13 protein was more abundant in liver tissue lysates from three HCV patients compared with controls, as were IL-13 serum levels in 68 patients with chronic HCV infection compared with 20 healthy volunteers (72.87 +/- 26.38 versus 45.41 +/- 3.73, P < 0.001). Immunohistochemistry results suggest that IL-13-mediated liver fibrogenesis may take place in the absence of phospho-signal transducer and activator of transcription protein 6 signaling. In a subgroup of patients with advanced liver fibrosis (stage > or =3), neither TGF-beta nor IL-13 signaling was detectable. Conclusion: Depending on the cause of liver damage, a predominance of TGF-beta or IL-13 signaling is found. TGF-beta1 predominance is detected in HBV-related liver fibrogenesis and IL-13 predominance in chronic HCV infection. In some instances, the underlying fibrogenic mediator remains enigmatic.

NGRIP CH4 concentration from 120 to 10 kyr before present and its relation to a δ15N temperature reconstruction from the same ice core

During the last glacial cycle, Greenland temperature showed many rapid temperature variations, the so-called Dansgaard–Oeschger (DO) events. The past atmospheric methane concentration closely followed these temperature variations, which implies that the warmings recorded in Greenland were probably hemispheric in extent. Here we substantially extend and complete the North Greenland Ice Core Project (NGRIP) methane record from the Preboreal Holocene (PB) back to the end of the last interglacial period with a mean time resolution of 54 yr. We relate the amplitudes of the methane increases associated with DO events to the amplitudes of the local Greenland NGRIP temperature increases derived from stable nitrogen isotope (δ15N) measurements, which have been performed along the same ice core (Kindler et al., 2014). We find the ratio to oscillate between 5 parts per billion (ppb) per °C and 18 ppb °C−1 with the approximate frequency of the precessional cycle. A remarkably high ratio of 25.5 ppb °C−1 is reached during the transition from the Younger Dryas (YD) to the PB. Analysis of the timing of the fast methane and temperature increases reveals significant lags of the methane increases relative to NGRIP temperature for DO events 5, 9, 10, 11, 13, 15, 19, and 20. These events generally have small methane increase rates and we hypothesize that the lag is caused by pronounced northward displacement of the source regions from stadial to interstadial. We further show that the relative interpolar concentration difference (rIPD) of methane is about 4.5% for the stadials between DO events 18 and 20, which is in the same order as in the stadials before and after DO event 2 around the Last Glacial Maximum. The rIPD of methane remains relatively stable throughout the full last glacial, with a tendency for elevated values during interstadial compared to stadial periods.

Eocene-Oligocene calcareous nannofossils from ODP sites 115-711 and 120-748 in the Indian Ocean

An Eocene-Oligocene calcareous nannofossil biostratigraphic framework for Ocean Drilling Program (ODP) Site 748 in the southern Indian Ocean is established, which provides a foundation for this and future quantitative biogeographic studies. This biostratigraphic analysis, together with quantitative nannofossil data, enables a reinterpretation of the preliminary magnetostratigraphy and a new placement for magnetic Subchron CBN in the lowermost Oligocene. Calcareous nannofossil species diversity is low at Site 748 relative to lower latitude sites, with about 13 taxa in the middle Eocene, gradually decreasing to about 6 in the late Oligocene. There is, however, no apparent mass extinction at any stratigraphic level. Similarly, no mass extinctions were recorded at or near the Eocene/Oligocene boundary at Site 711 in the equatorial Indian Ocean. Species diversity at the equatorial site is significantly higher than at Site 748, with a maximum of 39 species in the middle Eocene and a minimum of 14 species in the late Oligocene. The abundance patterns of nannofossil taxa are also quite different at the two sites, with chiasmoliths, Isthmolithus recurvus, and Reticulofenestra daviesii abundant and restricted to the high-latitude site and Coccolithus formosus, discoasters, and sphenoliths abundant at the equatorial site but impoverished at the high-latitude site. This indicates a significant latitudinal biogeographic gradient between the equatorial site and the high-latitude site in the Indian Ocean for the middle Eocene-Oligocene interval. The abundance change of warm-water taxa is similar to that of species diversity at Site 711. There is a general trend of decreasing abundance of warm-water taxa from the middle Eocene through the early Oligocene at Site 711, suggesting a gradual cooling of the surface waters in the equatorial Indian Ocean. The abundance of warm-water taxa increased in the late Oligocene, in association with an increase in species diversity, and this may reflect a warming of the surface waters in the late Oligocene. An abrupt increase in the abundance of cool-water taxa (from ~20% to over 90%) occurred from 36.3 to 35.9 Ma at high-latitude Site 748. Coincident with this event was a ~1.0 per mil positive shift in the delta18O value of planktonic foraminifers and the occurrence of ice-rafted debris. This abrupt change in the nannofossil population is a useful biostratigraphic event for locating the bottom of magnetic Subchron C13N in the Southern Ocean. The sharp increase in cool-water taxa coeval with a large positive shift in delta18O values suggests that the high-latitude surface waters drastically cooled around 36.3-35.9 Ma. The temperature drop is estimated to be 4°C or more at Site 748 based on the nannofossil population change relative to the latitudinal biogeographic gradient established in the South Atlantic Ocean during previous studies. Consequently, much of the delta18O increase at Site 748 appears to be due to a temperature drop in the high latitudes rather than an ice-volume signal. The ~0.1 per mil delta18O increase not accounted for by the temperature drop is attributed to an ice-volume increase of 4.6 * 10**3 km**3, or 20% the size of the present Antarctic ice sheet.

Teócrito (Idilios 13 y 22), Apolonio de Rodas (II 282-283) y Propercio I 20 : Una contaminación

Este artículo analiza la contaminación que de los idilios 13 y 22 de Teócrito y de los versos II 282-283 del poema de Apolonio de Rodas realiza Propercio en su elegía 1, 20.

Jornadas del Centro de Estudios Latinos, 12 y 13 de junio de 2001

Fil: Rollié, Emilio Federico. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.