49 resultados para Forms of production


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Over many millions of years of independent evolution, placental, marsupial and monotreme mammals have diverged conspicuously in physiology, life history and reproductive ecology. The differences in life histories are particularly striking. Compared with placentals, marsupials exhibit shorter pregnancy, smaller size of offspring at birth and longer period of lactation in the pouch. Monotremes also exhibit short pregnancy, but incubate embryos in eggs, followed by a long period of post-hatching lactation. Using a large sample of mammalian species, we show that, remarkably, despite their very different life histories, the scaling of production rates is statistically indistinguishable across mammalian lineages. Apparently all mammals are subject to the same fundamental metabolic constraints on productivity, because they share similar body designs, vascular systems and costs of producing new tissue.

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We present, pedagogically, the Bayesian approach to composed error models under alternative, hierarchical characterizations; demonstrate, briefly, the Bayesian approach to model comparison using recent advances in Markov Chain Monte Carlo (MCMC) methods; and illustrate, empirically, the value of these techniques to natural resource economics and coastal fisheries management, in particular. The Bayesian approach to fisheries efficiency analysis is interesting for at least three reasons. First, it is a robust and highly flexible alternative to commonly applied, frequentist procedures, which dominate the literature. Second,the Bayesian approach is extremely simple to implement, requiring only a modest addition to most natural-resource economist tool-kits. Third, despite its attractions, applications of Bayesian methodology in coastal fisheries management are few.

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This paper examines the relationship between the use of names and other words in address and in reference: how does the way that speaker A addresses B differ from the way that A refers to B, and what are the factors affecting this difference? The study, based on observation and interviews, attempts both to solve a problem in pragmatics and to help historical linguists and others who need to know the extent to which it may be justified to extrapolate from referential to address usage and vice versa.

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Acute intermittent porphyria is an inborn error of haem synthesis which is transmitted as a dominant character with variable phenotypic expression. The disorder is caused by a partial deficiency of porphobilinogen deaminase in all tissues so far studied. The nature of the enzymatic deficiency of porphobilinogen deaminase in haemolysates from patients with acute intermittent porphyria was examined by the use of monospecific antibody probes. In affected heterozygotes from three British pedigrees of diverse ancestry, the catalytic deficiency of porphobilinogen deaminase was accompanied by diminished enzyme protein, as determined by radial immunodiffusion. No evidence of functionally attenuated enzyme was demonstrable by kinetic studies. The molecular forms of the residual enzyme were investigated in red cell extracts and in lysed preparations of reticulocytes by a sensitive Western blotting procedure. This revealed the presence of reduced amounts of porphobilinogen deaminase polypeptide co-migrating with wild type enzyme (Mr approximately 40,000), and no evidence of variant forms in situ. The studies show that porphobilinogen deaminase deficiency in acute intermittent porphyria is commonly associated with a CRM-phenotype. The residual activity under these circumstances is thus related to expression of a single normal allele, since sensitive techniques detected neither aberrant nor degraded forms of the enzyme in erythroid tissues.

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This study analyses soil organic carbon (SOC) and hot-water extractable carbon (HWC), both measures of soil quality, under different land management: (1) conventional tillage (CT); (2) CT plus the addition of oil mill waste alperujo (A); (3) CT plus the addition of oil mill waste olive leaves (L); (4) no tillage with chipped pruned branches (NT1); and (5) no tillage with chipped pruned branches and weeds (NT2); in a typical Mediterranean agricultural area; the olive groves of Andalucía, southern Spain. SOC values in CT, A, NT1 and NT2 decreased with depth, but in NT2 the surface horizon (0-5 cm) had higher values than the other treatments, 47% more than the average values in the other three soils. In L, SOC also decreased with depth, although there was an increase of 88.5% from the first (0-10 cm) to the second horizon (10-16 cm). Total SOC stock values were very similar under A (101.9 Mg ha−1), CT (101.7 Mg ha−1), NT1 (105.8 Mg ha−1) and NT2 (111.3 Mg ha−1, if we consider the same depth of the others). However, SOC under L was significantly higher (p < 0.05) at 250.2 Mg ha−1. HWC decreased with depth in A, CT and NT1. NT2 and L followed the same pattern as the other management types but with a higher value in the surface horizon (2.3 and 4.9 mg g−1 respectively). Overall, our results indicate that application of oil mill waste olive leaves under CT (L) is a good management practice to improve SOC and reduce waste.

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In situ generation of HCl or HBr in alcohol leads to O-protonation of the amide group of carbamazepine. Six salt phases have been produced using this method and their crystal structures determined by single crystal diffraction. A new polymorph of carbamazepine hydrochloride is described as are two polymorphs of carbamazepine hydrobromide. All are protonated at the amide O atom to give RC(OH)NH2 cations. Prolonged exposure to air results in addition of water to the solid salt forms. Such hydration of carbamazepine hydrobromide simply gives a monohydrated phase, but similar treatment of the equivalent hydrochloride results in partial loss of HCl and the transfer of the remaining proton from the amide group to water to give [carbamazepine][H3O]0.5[Cl]0.5·H2O. A similar hydronium chloride species is the only product isolated after reaction of the carbamazepine analogue cytenamide with HCl generated in methanol.

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A sequential extraction method was utilized to analyze seven forms of P in an integrated vertical-flow constructed wetland (IVFCW) containing earthworms and different substrates. The aluminum-bound P (Al-P) content was found to be lower, and the occluded P (Oc-P) content was higher in the IVFCW. The addition of earthworms into the influent chamber of IVFCW increased the exchange P (Ex-P), iron-bound P (Fe-P), calcium bound P (Ca-P), Oc-P, detritus-bound (De-P) and organic P (Org-P) content in the influent chamber, and also enhanced P content uptake by wetland plants. A significantly positive correlation between P content of above-ground wetland plants and the Ex-P, Fe-P, Oc-P and Org-P content in the rhizosphere was found (P < 0.05), which indicated that the Ex-P, Fe-P, Oc-P and Org-P could be bio-available P. The Ex-P, Fe-P, De-P, Oc-P and Ca-P content of the influent chamber was higher where the substrate contained a mixture of Qing sand and river sand rather than only river sand. Also the IVFCW with earthworms and both Qing sand and river sand had a higher removal efficiency of P, which was related to higher P content uptake by wetland plants and P retained in IVFCW. These findings suggest that addition of earthworms in IVFCW increases the bioavailable P content, resulting in enhanced P content uptake by wetland plants.