Effects of agricultural management on Si cycling in Italian paddy fields

Silicon (Si) is a beneficial nutrient for rice plants; it improves their resistance against biotic and abiotic stresses. Recent research showed that Si availability in soils is, on a large geographic scale, determined by stocks of weatherable silicate minerals. However, also on the smaller regional scale, pronounced differences in Si uptake of rice plants were observed. The reasons for these differences are not yet clear. They might include effects of agricultural management, such as crop residue recycling and irrigation. Here, we test the long-term effects of four different agricultural management practices in Vercelli (Northwest Italy), where one rice crop per year is cultivated from May to September. The experimental platform was installed in 2003 on a Haplic Gleysol known to be under continuous rice cultivation for the last 30 years and having low plant-available Si concentration. The following management practices were considered (i) tillage and crop residue incorporation in spring (ii) post-harvest rice straw burning and tillage in spring, (iii) tillage and crop residue incorporation in autumn, and (iv) tillage and crop residue incorporation in spring followed by dry seeding and delayed flooding. After seven years, in 2010, topsoil and plants were sampled at five points of time during the cropping season. We will examine plant-available Si concentrations in soil and Si uptake by rice. Results will be presented at the conference; they will reveal whether farmers are able to actively improve Si supply to rice plants by their agricultural management

The Value of Global Earth Observations

Humankind has never been so populous, technically equipped, and economically and culturally integrated as it is today. In the twenty-first century, societies are confronted with a multitude of challenges in their efforts to manage the Earth system

Abacavir, efavirenz, didanosine, with or without hydroxyurea, in HIV-infected adults failing initial nucleoside/protease inhibitor-containing regimens

Background: Hydroxyurea (HU) is an immunomodulatory agent that has been documented to enhance the antiretroviral activity of nucleoside reverse transcriptase inhibitors, such as abacavir (ABC) and didanosine (ddI), and would be expected to improve virologic efficacy. Methods: A 48-week, phase IV, multicenter, open-label, proof-of-concept clinical trial was conducted to evaluate second-line, protease inhibitor (PI)-sparing therapy with ABC/efavirenz (EFV)/ddl plus HU or without HU in HIV-infected subjects failing to achieve HIV-1 RNA ≤ 400 copies/mL after ≥ 16 weeks of treatment with lamivudine /zidovudine or lamivudine/stavudine, plus 1 or 2 Pls. Subjects were assigned to ABC (300 mg twice daily)/ EFV (600 mg once daily)/ ddI (400 mg once daily) plus HU (500 mg twice daily) (n = 30) or this regimen without HU (n = 24). Results: Baseline mean HIV-1 RNA was 3.86 log10 copies/mL and CD4+ cell count was 345 cells/mm3. A similar percentage of subjects in the non-HU arm (58%) and HU arm (53%) completed the study. Intent-to-treat: missing = failure analysis showed no differences in proportions of subjects in the non-HU and HU arms achieving undetectable plasma HIV-1 RNA levels at week 24 (<400 copies/mL: 58% [14/24] vs 57% [17/30], P = 0.899; <50 copies/mL (50% [12/24] vs 47% [14/30], P = 0.780). Median change from baseline in CD4+ cell count in the non-HU and HU arms at week 48 was +114 cells/mm3 and -63 cells/mm3 (P = 0.007), respectively. Both regimens were generally well tolerated, although more subjects in the HU arm withdrew prematurely from the study due to adverse events (23% vs 4%). Four cases of possible ABC-related hypersensitivity were observed. Conclusion: ABC/EFV/ddI was an effective and well-tolerated second-line regimen for nucleoside/PI-experienced HIV-infected subjects. The addition of HU blunted the CD4+ cell response, did not appear to enhance antiviral activity, and resulted in more treatment-limiting adverse events

Multiple dimensions of biodiversity drive human interest in tide pool communities

Abstract Activities involving observation of wild organisms (e.g. wildlife watching, tidepooling) can provide recreational and learning opportunities, with biologically diverse animal assemblages expected to be more stimulating to humans. In turn, more diverse communities may enhance human interest and facilitate provisioning of cultural services. However, no experimental tests of this biodiversity-interest hypothesis exist to date. We therefore investigated the effects of different dimensions of animal biodiversity (species richness, phyletic richness and functional diversity) on self-reported interest using tide pools as a model system. We performed two experiments by manipulating: (1) the richness of lower (species) and higher taxonomic levels (phyla) in an image based, online survey, and (2) the richness of the higher taxonomic level (phyla) in live public exhibits. In both experiments, we further quantified functional diversity, which varied freely, and within the online experiment we also included the hue diversity and colourfulness arising from the combination of organisms and the background scenes. Interest was increased by phyletic richness (both studies), animal species richness (online study) and functional diversity (online study). A structural equation model revealed that functional diversity and colourfulness (of the whole scene) also partially mediated the effects of phyletic richness on interest in the online study. In both studies, the presence of three of four phyla additively increased interest, supporting the importance of multiple, diverse phyla rather than a single particularly interesting phylum. These results provide novel experimental evidence that multiple dimensions of biodiversity enhance human interest and suggest that conservation initiatives that maintain or restore biodiversity will help stimulate interest in ecosystems, facilitating educational and recreational benefits

Enhancement of resistance to murine osteogenic sarcoma in vivo by an extract of Brucella abortus (Bru-Pel): association with activation of reticuloendothelial system macrophages.

The administration of an aqueous-ether extracted residue of Brucella abortus (Bru-Pel) inhibits development of transplanted osteogenic sarcomas in mice as evidenced by a decrease in mortality. At least one mechanism through which Bru-Pel modulates host resistance is activation of macrophages of the reticuloendothelial system. Peritoneal macrophages harvested from mice receiving Bru-Pel were cytotoxic for osteogenic sarcoma cells in vitro, limited the replication of vaccinia virus in cell cultures, and demonstrated enhanced emittance of chemiluminescence during phagocytosis of zymosan particles of Candida albicans. The concept of reticuloendothelial system activation was further supported by the evidence that administration of Bru-Pel enhanced resistance of mice to challenge with a lethal inoculum of Listeria monocytogenes. These observation support the hypothesis that Bru-Pel shares a number of characteristics with recognized immunomodulating agents and that one mechanism by which it modulates host resistance to tumors, to virus infections, and to challenge with L. monocytogenes is through activation of macrophages