5,076 research outputs found
Data issues in general equilibrium modelling
In recent years global general equilibrium (GE) models have been used to analyse policy issues such as trade liberalisation, regional integration and environmental policies. While a global CGE model is an excellent tool to perform a comprehensive analysis of such policies, it requires an enormous amount of data to calibrate or parameterise the model itself. Quality differences in the data sets might affect the results of the model simulation. Identifying and removing problems in the database is an important task for the effective use of a CGE model. In this paper, we suggest an approach to detect and remove major inconsistencies from the database of a CGE model. To illustrate, we examine and modify selected interindustry transactions in the GTAP version 5 database, a general equilibrium database of the global economy. The revised database was evaluated against the original by undertaking technical change and trade liberalisation experiments using Global Trade Analysis Project (GTAP) model. Results show that estimates using the modified database are more credible than those from the original database.International Relations/Trade, Research Methods/ Statistical Methods,
Determinants of non-farm labour participation rates among farmers in Australia
In recent decades, non‐farm employment has become prevalent and an important source of income for Australian farm families. However, models identifying the relative significance of the socioeconomic variables influencing non‐farm employment participation rates have never been estimated in Australia. In this paper, a bivariate probit model of non‐farm employment participation rates was estimated, using information from the Australian Bureau of Agricultural Resource Economics (ABARE) 1994–1995 surveys. It was found that the participation decision of the farm operator and spouse is likely to be jointly determined, that non‐farm employment participation increased at a declining rate with age among farmers and that university education enhances the participation rates particularly among spouses. Participation rates were also higher among spouses with lower other income and with no dependent children.Farm Management,
Unión de péptidos a superficies de titanio para la mejora de la osteointegración
El presente estudio pretende mejorar el proceso de osteointegración del implante de titanio mediante la biofuncionalización de su superficie. Para ello se ha realizado una previa silanización de la superficie y una posterior unión covalente entre el silano y un péptido el cual posee la secuencia RGD. Se han estudiado diferentes aspectos como es la estabilidad tanto de conjunto titanio-silano como silano-péptido. Finalmente se ha realizado un ensayo de adhesión celular utilizando células osteoblásticas MG63 cuyas muestras de titanio han sido previamente biofuncionalizadas con el proceso estudiado.This study aims to improve the osseointegration process of the titanium implant through surface biofunctionalization. Samples were silanised on the surface and afterwards a peptide with the RGD sequence was covalently attached to the silane. Specific characteristics of the stability of the union titanium-silane as well as silane-peptide were studied. Finally cell adhesion studies to samples biofunctionalized with the technique studied in this work were made with MG63 osteoblastic cells.Peer Reviewe
Seminal plasma AnnexinA2 protein is a relevant biomarker for stallions which require removal of seminal plasma for sperm survival upon refrigeration
Some stallions yield ejaculates that do not tolerate conservation by refrigeration prior to artificial insemination (AI), showing improvement after removal of most of the seminal plasma (SP) by centrifugation. In this study, the SP-proteome of 10 different stallions was defined through high-performance liquid chromatography with tandem mass spectrometry and bioinformatic analysis in relation to the ability of the ejaculates to maintain semen quality when cooled and stored at 5°C. Stallions were classified into three groups, depending on this ability: those maintaining good quality after direct extension in a commercial extender (good), stallions requiring removal of seminal plasma (RSP) to maintain seminal quality (good-RSP), and stallions, unable to maintain good semen quality even after RSP (poor). Pathway enrichment analysis of the proteins identified in whole equine SP using human orthologs was performed using g: profiler showing enriched Reactome and the Kyoto Encyclopedia of Genes and Genomes pathways related to hexose metabolism, vesicle mediated transport, post translational modification of proteins and immune response. Specific proteins overrepresented in stallions tolerating conservation by refrigeration included a peroxiredoxin-6 like protein, and transcobalamin-2, a primary vitamin B12-binding, and transport protein. Also, the protein involved in protein glycosylation, ST3 beta-galactoside alpha-2,3-sialyltransferase 1 was present in good stallions. These proteins were nearly absent in poor stallions. Particularly, annexinA2 appeared as to be the most powerful discriminant variable for identification of stallions needing RSP prior to refrigeration, with a P = 0.002 and a q value = 0.005. Overall this is the first detailed study of the equine SP-proteome, showing the potential value of specific proteins as discriminant bio-markers for clinical classification of stallions for AI
Differences in the proteome of stallion spermatozoa explain stallion-to-stallion variability in sperm quality post-thaw†
The identification of stallions and or ejaculates that will provide commercially acceptable quality post-thaw before cryopreservation is of great interest, avoiding wasting time and resources freezing ejaculates that will not achieve sufficient quality to be marketed. Our hypothesis was that after bioinformatic analysis, the study of the stallion sperm proteome can provide discriminant variables able to predict the post-thaw quality of the ejaculate. At least three ejaculates from 10 different stallions were frozen following a split sample design. Half of the ejaculate was analyzed as a fresh aliquot and the other half was frozen and then analyzed as a frozen-thawed aliquot. Computer-assisted sperm analysis and flow cytometry were used to analyze sperm quality. Detailed proteomic analysis was performed on fresh and frozen and thawed aliquots, and bioinformatic analysis was used to identify discriminant variables in fresh samples able to predict the outcome of cryopreservation. Those with a fold change > 3, a P = 8.2e-04, and a q = 0.074 (equivalent to False discovery rate (FDR)) were selected, and the following proteins were identified in fresh samples as discriminant variables of good motility post-thaw: F6YTG8, K9K273, A0A3Q2I7V9, F7CE45, F6YU15, and F6SKR3. Other discriminant variables were also identified as predictors of good mitochondrial membrane potential and viability post-thaw. We concluded that proteomic approaches are a powerful tool to improve current sperm biotechnologies
Unconventional OFF–ON Response of a Mono(calix[4]arene)-Substituted BODIPY Sensor for Hg2+ through Dimerization Reversion
A new selective fluorogenic chemosensor for Hg2+, which combines a calixarene derivative with a BODIPY core as a fluorescent reporter, is described. The remarkable change in its fluorogenic properties in DMSO and CHCl3 has been analyzed. A study of its spectral properties on dilution, along with molecular modeling studies, allowed us to explain that this behavior involves the formation of a J-dimer, as well as how the sensing mechanism of Hg2+ proceeds
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