836 research outputs found
Carbon Emissions from Deforestation in the Brazilian Amazon Region
A simulation model based on satellite observations of monthly vegetation greenness from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000-2002. The NASA-CASA (Carnegie Ames Stanford Approach) model estimates of annual forest production were used for the first time as the basis to generate a prediction for the standing pool of carbon in above-ground biomass (AGB; gC/sq m) for forested areas of the Brazilian Amazon region. Plot-level measurements of the residence time of carbon in wood in Amazon forest from Malhi et al. (2006) were interpolated by inverse distance weighting algorithms and used with CASA to generate a new regional map of AGB. Data from the Brazilian PRODES (Estimativa do Desflorestamento da Amazonia) project were used to map deforested areas. Results show that net primary production (NPP) sinks for carbon varied between 4.25 Pg C/yr (1 Pg=10(exp 15)g) and 4.34 Pg C for the region and were highest across the eastern and northern Amazon areas, whereas deforestation sources of CO2 flux from decomposition of residual woody debris were higher and less seasonal in the central Amazon than in the eastern and southern areas. Increased woody debris from past deforestation events was predicted to alter the net ecosystem carbon balance of the Amazon region to generate annual CO2 source fluxes at least two times higher than previously predicted by CASA modeling studies. Variations in climate, land cover, and forest burning were predicted to release carbon at rates of 0.5 to 1 Pg C/yr from the Brazilian Amazon. When direct deforestation emissions of CO2 from forest burning of between 0.2 and 0.6 Pg C/yr in the Legal Amazon are overlooked in regional budgets, the year-to-year variations in this net biome flux may appear to be large, whereas our model results implies net biome fluxes had actually been relatively consistent from year to year during the period 2000-2002. This is the first study to use MODIS data to model all carbon pools (wood, leaf, root) dynamically in simulations of Amazon forest deforestation from clearing and burning of all kinds
New strategy, new accountability? The European Central Bank and the European Parliament after the strategy review
A striking asymmetry defines the European Central Bank (ECB)’s approach to democratic accountability. Although the post-2008 era saw the ECB move dramatically beyond the narrow role envisaged for it by the 1992 Maastricht Treaty, the central bank has continued to hew closely to its scarce accountability provisions.This article documents the much more complex and discretionary nature of today’s ECB policymaking by comparing the frameworks informing Governing Council deliberations according to the 1998, 2003 and 2021 strategies. It shows that the transformation of the ECB’s monetary policy strategy has not been matched with enhanced accountability arrangements between the ECB and the European Parliament. The article concludes with ambitious, but concrete policy proposals – both in substance and form – for new ways of informing the public about monetary policy, instruments to improve accountability and coordinating monetary policy with other European policymakers
Terrestrial carbon sinks for the United States Predicted from MODIS satellite data and ecosystem modeling
A simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of the conterminous United States over the period 2001-04. Predicted net ecosystem production (NEP) flux for atmospheric CO2 in the United States was estimated as annual net sink of about +0.2 Pg C in 2004. Regional climate patterns were reflected in the predicted annual NEP flux from the model, which showed extensive carbon sinks in ecosystems of the southern and eastern regions in 2003-04, and major carbon source fluxes from ecosystems in the Rocky Mountain and Pacific Northwest regions in 2003-04. As demonstrated through tower site comparisons, net primary production (NPP) modeled with monthly MODIS enhanced vegetation index (EVI) inputs closely resembles both the measured high- and low-season carbon fluxes. Modeling results suggest that the capacity of the NASA Carnegie Ames Stanford Approach (CASA) model to use 8-km resolution MODIS EVI data to predict peak growing season uptake rates of CO2 in irrigated croplands and moist temperate forests is strong
Reliability and Validity of the Dutch Translation of the Filial Maturity Measure in Informal Caregivers
This study explored the reliability and validity of a Dutch translation of the 10-item Filial Maturity Measure (FMM) in a sample of Dutch informal caregivers. The FMM was translated with a forward–backward method and completed by 93 informal caregivers (62 % response rate) with a need dependent parent. Dimensionality of the Dutch FMM was examined by principal component and internal consistency analyses. Criterion validity was examined by assessing correlations with filial love, filial autonomy and level of closeness between parent and child. Construct validity was tested by examining associations with the traits openness and agreeableness. In addition, the relationship with state and trait affectivity was explored. After removal of the item “I worry about turning out like my parent”, the original dimensional structure, internal consistency, criterion and construct validity were confirmed. Additional exploration of the relation between the FMM subscales and trait and state affectivity scales demonstrated that filial maturity is at most weakly associated with trait affectivity. Both FMM scales showed a positive partial correlation with negative state affectivity. The Dutch FMM appears to be a reliable and valid instrument for measuring filial maturity of informal caregivers who provide care to their need dependent parent. The (non-)functioning of one item pointed to the necessity to validate the FMM, but also questionnaires in general in different population
Regulation of Amino Acid Transport in Saccharomyces cerevisiae
SUMMARYWe review the mechanisms responsible for amino acid homeostasis in Saccharomyces cerevisiae and other fungi. Amino acid homeostasis is essential for cell growth and survival. Hence, the de novo synthesis reactions, metabolic conversions, and transport of amino acids are tightly regulated. Regulation varies from nitrogen pool sensing to control by individual amino acids and takes place at the gene (transcription), protein (posttranslational modification and allostery), and vesicle (trafficking and endocytosis) levels. The pools of amino acids are controlled via import, export, and compartmentalization. In yeast, the majority of the amino acid transporters belong to the APC (amino acid-polyamine-organocation) superfamily, and the proteins couple the uphill transport of amino acids to the electrochemical proton gradient. Although high-resolution structures of yeast amino acid transporters are not available, homology models have been successfully exploited to determine and engineer the catalytic and regulatory functions of the proteins. This has led to a further understanding of the underlying mechanisms of amino acid sensing and subsequent downregulation of transport. Advances in optical microscopy have revealed a new level of regulation of yeast amino acid transporters, which involves membrane domain partitioning. The significance and the interrelationships of the latest discoveries on amino acid homeostasis are put in context
Morin-type transition in 5C pyrrhotite
We report the discovery of a low temperature spin-flop transition in 5C pyrrhotite at ~155 K that is similar to those seen in hematite at 260 K and FeS (troilite) at 440 K. The 5C crystal was produced by annealing a 4C pyrrhotite crystal at 875 K, to produce a change in the vacancy-ordering scheme that developed during cooling. The 5C structure is confirmed by single crystal x-ray diffraction and the stoichiometry and homogeneity by electron microprobe and SEM BSE mapping. RUS, heat capacity and magnetisation measurements from room temperature down to 2 K are reported. The transition is marked by a steep change in elastic properties at the transition temperature, a peak in the heat capacity and weak anomalies in measurements of magnetisation. Magnetic hysteresis loops and comparison with the magnetic properties of 4C pyrrhotite suggest that the transition involves a change in orientation of moments between two different antiferromagnetic structures, perpendicular to the crystallographic c-axis at high temperatures and parallel to the crystallographic c-axis at low temperatures. The proposed structures are consistent with a group theoretical treatment that also predicts a first order transition between the magnetic structures.Leverhulme Trus
Growth Inhibition by Amino Acids in Saccharomyces cerevisiae
Amino acids are essential metabolites but can also be toxic when present at high levels intracellularly. Substrate-induced downregulation of amino acid transporters in Saccharomyces cerevisiae is thought to be a mechanism to avoid this toxicity. It has been shown that unregulated uptake by the general amino acid permease Gap1 causes cells to become sensitive to amino acids. Here, we show that overexpression of eight other amino acid transporters (Agp1, Bap2, Can1, Dip5, Gnp1, Lyp1, Put4, or Tat2) also induces a growth defect when specific single amino acids are present at concentrations of 0.5-5 mM. We can now state that all proteinogenic amino acids, as well as the important metabolite ornithine, are growth inhibitory to S. cerevisiae when transported into the cell at high enough levels. Measurements of initial transport rates and cytosolic pH show that toxicity is due to amino acid accumulation and not to the influx of co-transported protons. The amino acid sensitivity phenotype is a useful tool that reports on the in vivo activity of transporters and has allowed us to identify new transporter-specific substrates
Exploring Strategies To Promote Engagement And Active Learning Through Digital Course Design In Engineering Mathematics
This research explores the strategies and techniques used to foster and promote the engagement and active learning of engineering students within a digital course. This digital course has been developed to address the varying levels of understanding of fundamental mathematics among first-year engineering students, who often have disparate levels of prior knowledge at their high school completion. We observe an increasing need to bridge the widening gap between high school and university mathematics in order to prevent engineering students from being hindered in their academic successes due to a lack of prior mathematical understanding. With a team of engineers and mathematicians, both researchers and educators, we are developing a mathematics Bridging Course including the use of digital tools, such as videos, online interactions and technology-based assessments. These sources were created, investigated and/or modified to develop an engaging learning environment in which students are made aware of and guided through misconceptions and mistakes in their understanding of fundamental mathematics. In the development of this Bridging Course, we consider the importance of interactive learning and timely feedback for student learning. We investigate the impact of digital course design on students’ performance and learning outcomes using a qualitative approach. Students feedback within the first stage of the implementation of the course offered a positive assessment of the course, accentuating its inherent advantages and attributes. The students’ feedback proved to be an invaluable source of insights, specifically concerning the enhancement of question distractors, thus prompting revisions and augmentations in the assessment items employed
Synthesis studies of secondary forest productivity in the Amazon: field data, remote sensing, modeling approaches.
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