1000 resultados para Agrofood chain
Resumo:
Public capital has been considered to be the wheels of economic activity in a nation or region. The reverse effect, the contribution of economic growth to public capital, is also worth analysis. The non-structural vector auto-regression (VAR) approach is performed for the Australian economy using yearly data for the 1960-2008 period. The optimal lag is investigated to build the VAR model that is then tested for stability. The impulse response function is further employed to examine the response of one economic variable to the innovation of others and to determine the lagged terms for the maximum absolute value of the other variables’ responses. The results will provide historical evidence for the federal and regional governments of Australia to estimate the effects of these production variables, in particular, the effect of infrastructure spending on the gross domestic product.
Understanding the concept of elasticity in supply chain relationships : an agency theory perspective
Resumo:
The issue of flexibility in supply chains has been receiving heightened attention by scholars and practitioners especially as business environment becoming more turbulent and uncertain. Notwithstanding, one of the important aspects of flexibility – relationship flexibility – which has the potential to proliferate responsiveness and postpone bifurcation in buyer -supplier relationships has not been well understood and researched. Identifying this gap within the literature, this paper proposes a concept of elasticity as an important element of relationship flexibility in supply chains. It is argued that the tolerance threshold of coopering parties in presence of their sudden behaviour change will determine their state of relationship elasticity (i.e. elastic or inelastic). The theoretical development of this paper has been primarily based on review of the literature and insights from agency perspective. It is proposed that relationship governance mechanisms advocated by agency theory has the potential to influence elasticity status of principal agent relationships.
Resumo:
The aim of this research is to conduct a review on the approaches used to assess different criteria on sustainability used by supply chains and to suggest a framework for a methodical approach that would be easy and practical in making complex sustainable assessments. A review was conducted on the present models that are used to examine sustainability within supply chains. A sample of 332 companies mainly from the manufacturing area was examined to determine what criteria they require for assessing sustainable issues amongst their supply chains. A quantitative study using factor analysis and multiple regression were used to analyse the data to determine the statistical significance of the attempted prediction. It was identified that corporate commitment to sustainability, corporate reporting and management systems are significant predictors for green procurement in supply chain management. This framework can be beneficial in implementing environmental sustainable assessments for supply chains. Much of the empirical research on supply chains has focused on business performance, while there is very little empirical work undertaken in the literature on sustainable supply chains, Sustainability within supply chains implies that businesses need to consider the economic, environmental and social impacts of their activities.
Resumo:
This paper examines the experiences of three groups of technical managers: production and operations managers, logistics managers and quality managers in Britain and Australia, who play key roles in maintaining an effective supply chain. The analysis is divided into three sections: entry into the three different occupations, work experiences in them and continuing professional development needs. The paper offers fresh insights into the experiences of technical managers along the supply chain and provides senior management with recommendations for the more effective deployment and training of managers in these key roles.
Resumo:
Cross-strand pair correlations are calculated for residue pairs in antiparallel β-sheet for two cases: pairs whose backbone atoms are hydrogen bonded together (H-bonded site) and pairs which are not (non-H-bonded site). The statistics show that this distinction is important. When glycine is located on the edge of a sheet, it shows a 3:1 preference for the H-bonded site. Thestrongest observed correlations are for pairs of disulfide-bonded cystines, many of which adopt a close-packed conformation with each cystine in a spiral conformation of opposite chirality to its partner. It is likely that these pairs are a signature for the family of small, cystine-rich proteins. Most other strong positive and negative correlations involve charged and polar residues. It appears that electrostatic compatibility is the strongest factor affecting pair correlation. Significant correlations are observed for β- and γ-branched residues inthe non-H-bonded site. An examination of the structures showsa directionality in side chain packing. There is a correlation between (1) the directionality in the packing interactions of non-H-bonded β- and γ-branched residue pairs, (2) the handedness of the observed enantiomers of chiral β-branched side chains, and (3) the handedness of the twist of β-sheet. These findings have implications for the formation of β-sheets during protein folding and the mechanism by which the sheet becomes twisted
Resumo:
Cordycepin (3′ deoxyadenosine) is a biologically active compound that, when incorporated during RNA synthesis in vitro, provokes chain termination due to the absence of a 3′ hydroxyl moiety. We were interested in the effects mediated by this drug in vivo and analyzed its impact on RNA metabolism of yeast. Our results support the view that cordycepin-triphosphate (CoTP) is the toxic component that is limiting cell growth through inhibition of RNA synthesis. Unexpectedly, cordycepin treatment modulated 3′ end heterogeneity of ACT1 and ASC1 mRNAs and rapidly induced extended transcripts derived from CYH2 and NEL025c loci. Moreover, cordycepin ameliorated the growth defects of poly(A) polymerase mutants and the pap1-1 mutation neutralized the effects of the drug on gene expression. Our observations are consistent with an epistatic relationship between poly(A) polymerase function and cordycepin action and suggest that a major mode of cordycepin activity reduces 3′ end formation efficiency independently of its potential to terminate RNA chain elongation. Finally, chemical-genetic profiling revealed genome-wide pathways linked to cordycepin activity and identified novel genes involved in poly(A) homeostasis.
Resumo:
Omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) are almost unanimously recognized for their health benefits, while only limited evidence of any health benefit is currently available specifically for the main precursor of these fatty acids, namely α-linolenic acid (ALA, 18:3n-3). However, both the n-3 LC-PUFA and the short-chain C18 PUFA (i.e., ALA) are commonly referred to as “omega-3” fatty acids, and it is difficult for consumers to recognize this difference. A current gap of many food labelling legislations worldwide allow products containing only ALA and without n-3 LC-PUFA to be marketed as “omega-3 source” and this misleading information can negatively impact the ability of consumers to choose more healthy diets. Within the context of the documented nutritional and health promoting roles of omega-3 fatty acids, we briefly review the different metabolic fates of dietary ALA and n-3 LC-PUFA. We also review food sources rich in n-3 LC-PUFA, some characteristics of LC-PUFA and current industry and regulatory trends. A further objective is to present a case for regulatory bodies to clearly distinguish food products containing only ALA from foods containing n-3 LC-PUFA. Such information, when available, would then avoid misleading information and empower consumers to make a more informed choice in their food purchasing behavior.
Resumo:
The implementation of alternative lipid sources for use in aquaculture is of considerable interest globally. However, the possible benefit of using stearidonic acid (SDA)–rich fish oil (FO) alternatives has led to scientific confusion. Two hundred and forty rainbow trout (Oncorhynchus mykiss) were fed 1 of 4 diets (3 replicate tanks/treatment) containing either FO, linseed oil (LO), echium oil, or mixed vegetable oil (72% LO, 23% sunflower oil, and 6% canola oil) as the dietary lipid source (16.5%) for 73 d to investigate the competition and long-chain PUFA (LC-PUFA) biosynthesis between the fatty acid substrates α-linolenic acid (ALA) and SDA. SDA was more efficiently bioconverted to LC-PUFA compared with ALA. However, when the dietary lipid sources were directly compared, the increased provision of C18 PUFA within the LO diet resulted in no significant differences in (n-3) LC-PUFA content compared with fish fed the other diets. This study therefore shows that, rather than the previously speculated substrate competition, the limiting process in the apparent in vivo (n-3) LC-PUFA biosynthesis appears to be substrate availability. Rainbow trout fed the SDA- and ALA-rich dietary lipid sources subsequently had similar significant reductions in (n-3) LC-PUFA compared with fish fed the FO diet, therefore providing no additional dietary benefit on (n-3) LC-PUFA concentrations.
Resumo:
HIV-1 infection impairs a number of macrophage effector functions, thereby contributing to development of opportunistic infections and the pathogenesis of AIDS. FcγR-mediated phagocytosis by human monocyte-derived macrophages (MDM) is inhibited by HIV-1 infection in vitro, and the underlying mechanism was investigated in this study. Inhibition of phagocytosis directly correlated with the multiplicity of HIV-1 infection. Expression of surface FcγRs was unaffected by HIV-1 infection, suggesting that inhibition of phagocytosis occurred during or after receptor binding. HIV-1 infection of MDM markedly inhibited tyrosine phosphorylation of the cellular proteins, which occurs following engagement of FcγRs, suggesting a defect downstream of initial receptor activation. FcγR-mediated phagocytosis in HIV-infected MDM was associated with inhibition of phosphorylation of tyrosine kinases from two different families, Hck and Syk, defective formation of Syk complexes with other tyrosine-phosphorylated proteins, and inhibition of paxillin activation. Down-modulation of protein expression but not mRNA of the γ signaling subunit of FcγR (a docking site for Syk) was observed in HIV-infected MDM. Infection of MDM with a construct of HIV-1 in which nef was replaced with the gene for the γ signaling subunit augmented FcγR-mediated phagocytosis, suggesting that down-modulation of γ-chain protein expression in HIV-infected MDM caused the defective FcγR-mediated signaling and impairment of phagocytosis. This study is the first to demonstrate a specific alteration in phagocytosis signal transduction pathway, which provides a mechanism for the observed impaired FcγR-mediated phagocytosis in HIV-infected macrophages and contributes to the understanding of how HIV-1 impairs cell-mediated immunity leading to HIV-1 disease progression.