8 resultados para Tractor slippage
em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain
Resumo:
L’objectiu projecte és desenvolupar un sistema d’ajut al guiatge universal adaptable a qualsevol vehicle que permeti incrementar significativament l’eficiència de les feines a realitzar per la maquinària al camp. El sistema proposat es pot configurar d’acord amb les característiques de la maquinària o de la tasca a realitzar i és capaç de guiar en línia recta i crear paral·leles a la passada recta de referència. Un altre objectiu és millorar el rendiment, la fiabilitat i la usabilitat del programari de monitoratge inicial instal·lat al tractor, com també caracteritzar el receptor GPS AgGPS 332 de Trimble® per a comprovar la precisió de l’aparell. Els resultats obtinguts en la millora del programa de monitoratge són molt satisfactoris a l’haver corregit imprecisions de funcionament que en limitaven l’usabilitat. Els resultats obtinguts en la caracterització del receptor AgGPS 332 permeten valorar millor quin tipus de correcció diferencial és més convenient per a la precisió de treball requerida segons el seu cost de posada en marxa i de funcionament.Els resultats obtinguts en la validació de l’ajut al guiatge, han validat el guiatge a 10 metres vista com un ajut al guiatge equivalent al guiatge manual quan la velocitat de treball és de 5 km/h, el tractorista té referències visuals i no està fatigat. Els resultats obtinguts pels guiatges a 3 i 50 metres no són satisfactoris a 5 km/h. Tanmateix, durant el procés de disseny, la realització dels assajos i durant l’anàlisi de resultats s’han identificat algunes mancances i limitacions i es proposen una sèrie de millores per tal de solucionar-les.
Resumo:
La selección del tractor más adecuado para una determinada explotación frutícola requiere considerar dos aspectos fundamentales. En primer lugar, el fruticultor debe valorar la conveniencia económica de la adquisición frente a la posibilidad de contratar a empresas de servicios (sino en todas, sí para aquellas operaciones de mayor coste); en segundo lugar, la potencia del tractor deberá ser coherente en relación a las máquinas agrícolas que se le acoplen.
Resumo:
Background: Amino acid tandem repeats are found in nearly one-fifth of human proteins. Abnormal expansion of these regions is associated with several human disorders. To gain further insight into the mutational mechanisms that operate in this type of sequence, we have analyzed a large number of mutation variants derived from human expressed sequence tags (ESTs).Results: We identified 137 polymorphic variants in 115 different amino acid tandem repeats. Of these, 77 contained amino acid substitutions and 60 contained gaps (expansions or contractions of the repeat unit). The analysis showed that at least about 21% of the repeats might be polymorphic in humans. We compared the mutations found in different types of amino acid repeats and in adjacent regions. Overall, repeats showed a five-fold increase in the number of gap mutations compared to adjacent regions, reflecting the action of slippage within the repetitive structures. Gap and substitution mutations were very differently distributed between different amino acid repeat types. Among repeats containing gap variants we identified several disease and candidate disease genes.Conclusion: This is the first report at a genome-wide scale of the types of mutations occurring in the amino acid repeat component of the human proteome. We show that the mutational dynamics of different amino acid repeat types are very diverse. We provide a list of loci with highly variable repeat structures, some of which may be potentially involved in disease.
Resumo:
Amino acid tandem repeats, also called homopolymeric tracts, are extremely abundant in eukaryotic proteins. To gain insight into the genome-wide evolution of these regions in mammals, we analyzed the repeat content in a large data set of rat-mouse-human orthologs. Our results show that human proteins contain more amino acid repeats than rodent proteins and that trinucleotide repeats are also more abundant in human coding sequences. Using the human species as an outgroup, we were able to address differences in repeat loss and repeat gain in the rat and mouse lineages. In this data set, mouse proteins contain substantially more repeats than rat proteins, which can be at least partly attributed to a higher repeat loss in the rat lineage. The data are consistent with a role for trinucleotide slippage in the generation of novel amino acid repeats. We confirm the previously observed functional bias of proteins with repeats, with overrepresentation of transcription factors and DNA-binding proteins. We show that genes encoding amino acid repeats tend to have an unusually high GC content, and that differences in coding GC content among orthologs are directly related to the presence/absence of repeats. We propose that the different GC content isochore structure in rodents and humans may result in an increased amino acid repeat prevalence in the human lineage.
Resumo:
Low-complexity regions (LCRs) in proteins are tracts that are highly enriched in one or a few aminoacids. Given their high abundance, and their capacity to expand in relatively short periods of time through replication slippage, they can greatly contribute to increase protein sequence space and generate novel protein functions. However, little is known about the global impact of LCRs on protein evolution. We have traced back the evolutionary history of 2,802 LCRs from a large set of homologous protein families from H.sapiens, M.musculus, G.gallus, D.rerio and C.intestinalis. Transcriptional factors and other regulatory functions are overrepresented in proteins containing LCRs. We have found that the gain of novel LCRs is frequently associated with repeat expansion whereas the loss of LCRs is more often due to accumulation of amino acid substitutions as opposed to deletions. This dichotomy results in net protein sequence gain over time. We have detected a significant increase in the rate of accumulation of novel LCRs in the ancestral Amniota and mammalian branches, and a reduction in the chicken branch. Alanine and/or glycine-rich LCRs are overrepresented in recently emerged LCR sets from all branches, suggesting that their expansion is better tolerated than for other LCR types. LCRs enriched in positively charged amino acids show the contrary pattern, indicating an important effect of purifying selection in their maintenance. We have performed the first large-scale study on the evolutionary dynamics of LCRs in protein families. The study has shown that the composition of an LCR is an important determinant of its evolutionary pattern.
Resumo:
L’explotació ramadera a projectar és la “Can Pereaulet”, situada a la finca Can Pereaulet, situada al terme municipal de Bescanó, a la comarca del Gironès, manté una estructura d’àmbit familiar.L’objectiu d’aquest projecte és ampliar la capacitat de la granja Can Pereaulet per poder deslletar els vedells, millorar el benestar animal i la producció de vedells per a engreix a 600 vedells/any. La construcció de la nau permetrà una zona d’alimentació i descans totalment coberta, una zona d’exercici parcialment coberta i una sala de preparació i magatzem dels productes necessaris. De la granja actual s’utilitzarà una quadre per infermeria i la resta per diferents necessitats com ara, magatzem palla, garatge tractor
Resumo:
El neumático agrícola condiciona de forma determinante el rendimiento del tractor. Es necesario, por tanto, que el agricultar conozca las prestaciones de los neumáticos actuales. Ello le permitirá elegir el equipamiento más adecuado a sus necesidades.
Resumo:
A la hora de adquirir un tractor el viticultor y el fruticultor han de tener en cuenta sus necesidades, las características técnicas de la máquina y la utilidad de las innovaciones tecnológicas del mismo.