Highlights d 18S non-functional rRNA decay requires sequential uS3 ubiquitination d Hel2 and Rsp5 form a K63-linked polyubiquitin chain on uS3 monoubiquitinated by Mag2 d uS3 ubiquitination induces subunit dissociation of nonfunctional 80S by Slh1 (Rqt2)

Fires set for slash-and-burn agriculture contribute to the current unsustainable accumulation of atmospheric greenhouse gases, and they also deplete the soil of essential nutrients, which compromises agricultural sustainability at local scales. Integrated assessments of greenhouse gas emissions have compared intensive cropping systems in industrialized countries, but such assessments have not been applied to common cropping systems of smallholder farmers in developing countries. We report an integrated assessment of greenhouse gas emissions in slash-and-burn agriculture and an alternative chopand-mulch system in the Amazon Basin. The soil consumed atmospheric methane (CH 4 ) under slash-and-burn treatment and became a net emitter of CH 4 to the atmosphere under the mulch treatment. Mulching also caused about a 50% increase in soil emissions of nitric oxide and nitrous oxide and required greater use of fertilizer and fuel for farm machinery. Despite these significantly higher emissions of greenhouse gases during the cropping phase under the alternative chop-and-mulch system, calculated pyrogenic emissions in the slash-and-burn system were much larger, especially for CH 4 . The global warming potential CO 2 -equivalent emissions calculated for the entire crop cycles were at least five times lower in chop-and-mulch compared with slash-and-burn. The crop yields were similar for the two systems. While economic and logistical considerations remain to be worked out for alternatives to slash-and-burn, these results demonstrate a potential 'win-win' strategy for maintaining soil fertility and reducing net greenhouse gas emissions, thus simultaneously contributing to sustainability at both spatial scales.

The slash-and-burn practice of land preparation that farmers use traditionally in forest-based fallow systems in the humid tropics causes land degradation and human health hazards. As an alternative to slash-and-burn, a mechanized, fire-free method of land preparation was evaluated on smallholdings in the eastern Amazon region. The use of machinery for harvesting fallow vegetation and chopping it for mulch eliminates the need for hard labor and fire for land clearing and increases labor productivity. Four different tractor-propelled choppers with power demand of 50 kW to 122 kW were tested. Their chopping capacity varied between 4.5 Mg and 20 Mg of fresh biomass per hour. The mechanized chop-and-mulch technology can be used in fallow vegetation that is up to 12 years old, which in the study region corresponded to 20 Mg to 150 Mg fresh biomass per hectare. Two additional choppers-a stationary silage chopper and a high-powered crawler tractor with a chopping device-were also tested but both were not suitable for smallholder fallow systems. In the context of the mulch technology, new low-input crop varieties were screened and their response to fertilizer was studied. The mulch technology facilitates extended cropping, to plant crops off-season, and modify crop rotation. Degraded fallow vegetation can be improved by enrichment planting using fast-growing leguminous tree species. Financial analysis of different scenarios revealed that farm income and labor productivity from chop-and-mulch systems can be up to two times greater than from the traditional slash-and-burn system.

The present study indicates that chemotherapy with AZD7762 and cisplatin should be explored as a treatment modality for women with ovarian clear cell carcinoma.

Abstract.Patients with clear cell carcinoma of the ovary (OCCC) have poor survival due to resistance to standard chemotherapy. OCCC has frequent activating mutations of the PIK3CA gene. The present study was conducted to clarify the efficacy of the inhibition of the PI3K-AKT-mTOR pathway in OCCC. We used 8 OCCC cell lines and 5 ovarian serous adenocarcinoma (OSAC) cell lines. The mutation status of the PIK3CA and KRAS genes was examined by direct sequencing. The IC 50 values of NVP-BEZ235 (BEZ235) and temsirolimus were determined by WST-8 assay. Protein expression levels of PI3K-AKT-mTOR pathway molecules were examined by western blotting. Cell cycle distribution was analyzed by flow cytometry. Annexin V staining was used for detecting apoptosis. We also investigated the effects of BEZ235 on OCCC tumor growth in a nude mouse xenograft model. Four of the 8 OCCC cell lines showed a PIK3CA mutation while none of the 5 OSAC cell lines showed a mutation. The IC 50 values of BEZ235 for the OCCC cell lines were lower than these values for the OSAC cell lines. The IC 50 value of temsirolimus was higher than BEZ235 in the OCCC cell lines. The PIK3CA mutation was more frequently noted in OCCC than OSAC cells, but the sensitivity of these cell lines to BEZ235 or temsirolimus was not related to the mutation status. pHER3 and pAkt proteins were expressed more frequently in OCCC compared with OSAC. However, protein expression levels were distributed widely, and were not related to the sensitivity. Treatment with BEZ235 suppressed expression of pAkt, although treatment with temsirolimus did not. OCCC cells exhibited G 1 phase arrest after treatment with BEZ235 and apoptosis with a higher concentration of the agent. BEZ235 significantly inhibited tumor growth in mice bearing OVISE and TU-OC-1 cell tumors. The present study indicated that the PI3K-AKT-mTOR pathway is a potential target for OCCC, and that BEZ235 warrants investigation as a therapeutic agent. IntroductionClear cell carcinoma of the ovary (OCCC) is recognized in the World Health Organization classification of ovarian tumors as a distinct histological entity. Its clinical behavior is distinctly different from other epithelial ovarian cancers (1). OCCC accounts for 3.7-12.1% of epithelial ovarian cancers (2,3). We found that response rates for platinum-based chemotherapy were 11.1% for OCCC and 72.5% for serous adenocarcinoma (SAC), suggesting that OCCC resists conventional platinumbased chemotherapy (4). A novel therapeutic strategy is needed to improve the prognosis of patients with OCCC.PIK3CA is located at the 3q26.3 locus and encodes the catalytic subunit of the phosphatidylinositol 3-kinase (PI3K), p110α (5). In response to an extracellular signal, the activated p110α phosphorylates PIP2 to generate PIP3. The PIP3 recruits AKT to the plasma membrane, where it is phosphorylated and activated by phosphatidylinositol-dependent kinase 1 (PDK1) and PDK2. Activated AKT can directly activate the mammalian target of rapamycin (mTOR) by phosphorylation at Ser2448. mTOR ...

P P P P Palavras-chave: alavras-chave: alavras-chave: alavras-chave: alavras-chave: Experimento participativo. Banco de sementes. Manejo do solo. Regeneração. Agricultores. Plantas invasoras. Riqueza de espécies. 20 Banco de sementes em sistemas de produção de agricultura com queima e sem queima... AbstractAbstract Abstract Abstract Abstract: In slash-and-burn agriculture, secondary forest has a main role in the fertilization of the soil, after the burning of its plant biomass. Generally, successive burns tend to destroy all forms of regeneration, including the seed banks. With this problem in mind, the Studies of Human Impact on Forests and Floodplains in the Tropics Project (SHIFT), in which this research is inserted, after a series of basic studies on secondary forests in the region of Bragança, has been developing an alternative agricultural production in which secondary forest is used as a source of nutrients and organic matter for the soil in 'fire-free' agricultural production systems. The work was developed in the municipality of Marapanim, it was a participative experiment, a new project approach, where the farmers chose the areas. The objective of the present work was to assess the potential of the seed bank in areas subjected to different forms of soil management, characterizing qualitative and quantitatively. The hypothesis that fire diminishes the potential of seed banks and creates favorable conditions for the regeneration of invading herbaceous species was tested, as well as that chopped mulch minimizes the impacts caused by burning on plant diversity and increases the regeneration of biomass-accumulating species. The germination potential of seed banks in the treatments was monitored during 270 days. Density, species richness, families and predominating life forms were assessed in the treatments burn, chopped mulch. In the seed bank before soil management, the average density in burn was 284 individuals/m 2 and in the chopped mulch it was 328 individuals/m 2 , and after soil management in burn there were in average 23 individuals/ m 2 found and in the chopped mulch 139 individuals/m 2 . The most frequent species at both moments and treatments were Borreria latifolia, Fimbristylis meliacea and Cyperus diffusus. The families Cyperaceae, Rubiaceae and Poaceae appeared in high frequency in all areas and in both treatments. In addition, the families Euphorbiaceae, Melastomataceae, Malvaceae, Lamiaceae. Scrophulariaceae and Asteraceae stood out. The most common forms of life found in the treatments were herbs. The different treatments, affected the abundance and floristical richness decreasing the number of seeds of tree and shrub species, which are biomass accumulating.

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