An interlaboratory study of TEX86 and BIT analysis of sediments, extracts and standard mixtures.

Two commonly used proxies based on the distribution of glycerol dialkyl glycerol tetraethers (GDGTs) are the TEX86 (TetraEther indeX of 86 carbon atoms) paleothermometer for sea surface temperature reconstructions and the BIT (Branched Isoprenoid Tetraether) index for reconstructing soil organic matter input to the ocean. An initial round-robin study of two sediment extracts, in which 15 laboratories participated, showed relatively consistent TEX86 values (reproducibility ±3-4°C when translated to temperature) but a large spread in BIT measurements (reproducibility ±0.41 on a scale of 0-1). Here we report results of a second round-robin study with 35 laboratories in which three sediments, one sediment extract, and two mixtures of pure, isolated GDGTs were analyzed. The results for TEX86 and BIT index showed improvement compared to the previous round-robin study. The reproducibility, indicating interlaboratory variation, of TEX86 values ranged from 1.3 to 3.0°C when translated to temperature. These results are similar to those of other temperature proxies used in paleoceanography. Comparison of the results obtained from one of the three sediments showed that TEX86 and BIT indices are not significantly affected by interlaboratory differences in sediment extraction techniques. BIT values of the sediments and extracts were at the extremes of the index with values close to 0 or 1, and showed good reproducibility (ranging from 0.013 to 0.042). However, the measured BIT values for the two GDGT mixtures, with known molar ratios of crenarchaeol and branched GDGTs, had intermediate BIT values and showed poor reproducibility and a large overestimation of the "true" (i.e., molar-based) BIT index. The latter is likely due to, among other factors, the higher mass spectrometric response of branched GDGTs compared to crenarchaeol, which also varies among mass spectrometers. Correction for this different mass spectrometric response showed a considerable improvement in the reproducibility of BIT index measurements among laboratories, as well as a substantially improved estimation of molar-based BIT values. This suggests that standard mixtures should be used in order to obtain consistent, and molar-based, BIT values

The chemokine receptor CCR7 controls lymph node-dependent cytotoxic T cell priming in alloimmune responses

The chemokine receptor CCR7 and its ligands regulate migration and colocalization of T cells and mature dendritic cells to and within secondary lymphoid organs. The requirement of CCR7 in efficient priming of allospecific cytotoxic CD8+ T cells is poorly characterized. Here, we demonstrate a role for CCR7 in the initiation of an alloimmune response and in the development of transplant rejection. Remarkably, in a model of acute allogeneic tumor rejection, CCR7-/- mice completely failed to reject subcutaneously injected MHC class I mismatched tumor cells and cytotoxic activity of allospecific T cells was severely compromised. When solid tumors derived from wild-type mice were transplanted, recipient CCR7-/- mice were capable of rejecting the allografts. In contrast, tumor allografts transplanted from CCR7-/- donors onto CCR7-/- recipients showed allograft survival up to 28 days, suggesting a critical function of CCR7 on donor-type passenger leukocytes in the initiation of cytotoxic CD8+ T cell responses. In a heterotopic heart transplantation model CCR7 deficiency resulted in significantly prolonged but not indefinite allograft survival. Additional prolongation of graft survival was observed when hearts from CCR7-/- mice were used as donor organs. Our results define a key role for CCR7 in allogeneic T cell priming within the context of draining lymph nodes

Avaliações microclimáticas e das características de qualidade da uva de mesa 'Romana' com proteção individual dos cachos Microclimatic and quality characteristics evaluations for the 'Romana' seedless table grape bunch grown under individual protection

Com o objetivo de avaliar o efeito do uso de proteção individual de cachos, contra incidência de chuvas durante o período de maturação, no microclima, no controle de rachaduras e podridões e, principalmente, nas características de qualidade, foi realizado um experimento, em vinhedo da cultivar de uva de mesa sem sementes Romana (A1105), na região de Jundiaí (SP). Os tratamentos, constituídos pelo tipo de proteção individual dos cachos, foram: sem proteção; saco plástico transparente com fundo aberto; saco de papel impermeável com fundo aberto e papel impermeável translúcido (chapéu-chinês). Medições de temperatura do ar e umidade relativa foram efetuadas no nível do cacho nos tratamentos sem proteção e com proteção durante o período de maturação das uvas até a colheita. Os valores obtidos de temperatura foram: 23,9; 22,9 e 22,0 ºC, respectivamente, para os tratamentos saco plástico; chapéu-chinês e sem proteção. Os valores médios de umidade relativa foram mais elevados próximo dos cachos sem proteção (86,1%) quando comparados aos tratamentos: saco plástico (76,0%) e chapéu-chinês (73,2%). Em relação aos itens de qualidade dos cachos e controle de podridões, os tratamentos chapéu-chinês e saco de papel impermeável foram mais eficientes quando comparados ao tratamento sem proteção.<br>A field trial was carried out at Jundiaí, São Paulo State, Brazil, in a 'Romana' (A1105) seedless table grape vineyard aiming to evaluate the influence of individual bunch protection on microclimate and bunch quality, mainly for rot control. The different individual bunch protection against rain during the maturation period were: impermeable paper and polyethylene bunch cover. Measurements of temperature and relative humidity in the protected and unprotected bunchs were taken from beginning of maturation process to harvest. The obtained values of mean temperature were: 23.9; 22.9 and 22.0ºC, respectively for the treatments: polyethylene bag; impermeable paper and unprotected bunch environment. The values of mean relative humidity were higher at the bunches without protection (86.1%) when compared to the polyethylene bag (76.0%) and impermeable paper (73.2%). Also, the use of individual grape bunch protection (impermeable paper, polyethylene bag and impermeable paper bag) were effective in controlling bunch rot occurrence