Sustainability, certification, and regulation of biochar

Biochar has a relatively long half-life in soil and can fundamentally alter soil properties, processes, and ecosystem services. The prospect of global-scale biochar application to soils highlights the importance of a sophisticated and rigorous certification procedure. The objective of this work was to discuss the concept of integrating biochar properties with environmental and socioeconomic factors, in a sustainable biochar certification procedure that optimizes complementarity and compatibility between these factors over relevant time periods. Biochar effects and behavior should also be modelled at temporal scales similar to its expected functional lifetime in soils. Finally, when existing soil data are insufficient, soil sampling and analysis procedures need to be described as part of a biochar certification procedure.

Fiscal policy and private investment: latin america in a comparative perspective

The main objective of the paper is to assess the impact of fiscal variables on private investment comparing some Latin-American economies to other advanced ones. For such purposes, the authors carry out an econometric analysis for the period 1990-2008. They make use of two dynamic panel models in which they group countries with similar characteristics and development levels. In one of them, they include Mexico, Brazil, Chile, Colombia and Uruguay; whereas in the second one the countries accounted for are the U.S., Canada, Spain, Korea, Ireland and Japan. They specify in both models an investment function using as arguments a wide range of variables, including those related with fiscal policy. From their results the authors infer that governments can, with higher spending, boost up the economy even when they finance spending with higher taxes. In Latin America, where income concentration is enormous, a proposal to boost up the economy through higher government expenditure financed with a progressive income tax, is even more justified.

Studies on the production and regulation of interleukin, IL-13, IL-4 and interferon-gamma in human Schistosomiasis mansoni

The production and regulation of interleukin (IL) IL-13, IL-4 and interferon-gamma was evaluated in different clinical forms of human schistosomiasis. The mechanisms of immune regulation are apparently different in the various clinical stages of the disease, some of them being antigen specific.

Salt tolerance and regulation of gas exchange and hormonal homeostasis by auxin-priming in wheat

The objective of this work was to assess the regulatory effects of auxin-priming on gas exchange and hormonal homeostasis in spring wheat subjected to saline conditions. Seeds of MH-97 (salt-intolerant) and Inqlab-91 (salt-tolerant) cultivars were subjected to 11 priming treatments (three hormones x three concentrations + two controls) and evaluated under saline (15 dS m-1) and nonsaline (2.84 dS m-1) conditions. The priming treatments consisted of: 5.71, 8.56, and 11.42 × 10-4 mol L-1 indoleacetic acid; 4.92, 7.38, and 9.84 × 10-4 mol L-1 indolebutyric acid; 4.89, 7.34, and 9.79 × 10-4 mol L-1 tryptophan; and a control with hydroprimed seeds. A negative control with nonprimed seeds was also evaluated. All priming agents diminished the effects of salinity on endogenous abscisic acid concentration in the salt-intolerant cultivar. Grain yield was positively correlated with net CO2 assimilation rate and endogenous indoleacetic acid concentration, and it was negatively correlated with abscisic acid and free polyamine concentrations. In general, the priming treatment with tryptophan at 4.89 × 10-4 mol L-1 was the most effective in minimizing yield losses and reductions in net CO2 assimilation rate, under salt stress conditions. Hormonal homeostasis increases net CO2 assimilation rate and confers tolerance to salinity on spring wheat.

Cl- and regulation of pH by MDCK-C11 cells

The interaction between H+ extrusion via H+-ATPase and Cl- conductance was studied in the C11 clone of MDCK cells, akin to the intercalated cells of the collecting duct. Cell pH (pHi) was measured by fluorescence microscopy using the fluorescein-derived probe BCECF-AM. Control recovery rate measured after a 20 mM NH4Cl acid pulse was 0.136 ± 0.008 pH units/min (dpHi/dt) in Na+ Ringer and 0.032 ± 0.003 in the absence of Na+ (0 Na+). With 0 Na+ plus the Cl- channel inhibitor NPPB (10 µM), recovery was reduced to 0.014 ± 0.001 dpHi/dt. 8-Br-cAMP, known to activate CFTR Cl- channels, increased dpHi/dt in 0 Na+ to 0.061 ± 0.009 and also in the presence of 46 nM concanamycin and 50 µM Schering 28080. Since it is thought that the Cl- dependence of H+-ATPase might be due to its electrogenic nature and the establishment of a +PD (potential difference) across the cell membrane, the effect of 10 µM valinomycin at high (100 mM) K+ was tested in our cells. In Na+ Ringer, dpHi/dt was increased, but no effect was detected in 0 Na+ Ringer in the presence of NPPB, indicating that in intact C11 cells the effect of blocking Cl- channels on dpHi/dt was not due to an adverse electrical gradient. The effect of 100 µM ATP was studied in 0 Na+ Ringer solution; this treatment caused a significant inhibition of dpHi/dt, reversed by 50 µM Bapta. We have shown that H+-ATPase present in MDCK C11 cells depends on Cl- ions and their channels, being regulated by cAMP and ATP, but not by the electrical gradient established by electrogenic H+ transport.

Uncertainties, monetary policy and financial stability: challenges on inflation targeting

This work aims at presenting the challenges that inflation targeting central banks may face since uncertainties represent a harmful element for the effectiveness of monetary policy, and since financial instabilities may disturb the transmission mechanisms - in particular, the expectation channel - and thus the economic stability. Financial stability must not be considered as a simple goal of monetary policy, but a precondition for central banks operate their policies and reach the goals of inflation and output stability. The work identifies different sources of uncertainties that surround central banks' decisions; and approaches the role that inflation targeting central banks should play according to some basic principles that can serve as useful guides for central banks to help them achieve successful outcomes in their conduct of monetary policy.