900 resultados para Economic efficiency
Resumo:
Soil organic carbon sequestration rates over 20 years based on the Intergovernmental Panel for Climate Change (IPCC) methodology were combined with local economic data to determine the potential for soil C sequestration in wheat-based production systems on the Indo-Gangetic Plain (IGP). The C sequestration potential of rice–wheat systems of India on conversion to no-tillage is estimated to be 44.1 Mt C over 20 years. Implementing no-tillage practices in maize–wheat and cotton–wheat production systems would yield an additional 6.6 Mt C. This offset is equivalent to 9.6% of India's annual greenhouse gas emissions (519 Mt C) from all sectors (excluding land use change and forestry), or less than one percent per annum. The economic analysis was summarized as carbon supply curves expressing the total additional C accumulated over 20 year for a price per tonne of carbon sequestered ranging from zero to USD 200. At a carbon price of USD 25 Mg C−1, 3 Mt C (7% of the soil C sequestration potential) could be sequestered over 20 years through the implementation of no-till cropping practices in rice–wheat systems of the Indian States of the IGP, increasing to 7.3 Mt C (17% of the soil C sequestration potential) at USD 50 Mg C−1. Maximum levels of sequestration could be attained with carbon prices approaching USD 200 Mg C−1 for the States of Bihar and Punjab. At this carbon price, a total of 34.7 Mt C (79% of the estimated C sequestration potential) could be sequestered over 20 years across the rice–wheat region of India, with Uttar Pradesh contributing 13.9 Mt C.
Resumo:
An array of substrates link the tryptic serine protease, kallikrein-related peptidase 14 (KLK14), to physiological functions including desquamation and activation of signaling molecules associated with inflammation and cancer. Recognition of protease cleavage sequences is driven by complementarity between exposed substrate motifs and the physicochemical signature of an enzyme's active site cleft. However, conventional substrate screening methods have generated conflicting subsite profiles for KLK14. This study utilizes a recently developed screening technique, the sparse matrix library, to identify five novel high-efficiency sequences for KLK14. The optimal sequence, YASR, was cleaved with higher efficiency (k(cat)/K(m)=3.81 ± 0.4 × 10(6) M(-1) s(-1)) than favored substrates from positional scanning and phage display by 2- and 10-fold, respectively. Binding site cooperativity was prominent among preferred sequences, which enabled optimal interaction at all subsites as indicated by predictive modeling of KLK14/substrate complexes. These simulations constitute the first molecular dynamics analysis of KLK14 and offer a structural rationale for the divergent subsite preferences evident between KLK14 and closely related KLKs, KLK4 and KLK5. Collectively, these findings highlight the importance of binding site cooperativity in protease substrate recognition, which has implications for discovery of optimal substrates and engineering highly effective protease inhibitors.
Resumo:
In recent years ‘‘welfare reform’’ has become a vehicle for many neo-conservative social commentators to invoke marriage vows as a cure for poverty and the abuse of poor women. Their basic claim is that cohabiting relationships are not only more violent than marriages, but that married couples are happier, healthier, and wealthier than cohabiting ones. A policy then of encouraging cohabitants to marry, they claim, would lead to increased family wealth and decreased family violence. We examine these claims in this article, along with the alternative argument that marriage per se is not a solution to these problems. Alternatively we propose an economic exclusion/male peer support model that explains why many cohabiting men abuse women in intimate relationships. If forcing these couples to marry is not a solution, then structural solutions are necessary, along with progressive policy suggestions that address the antecedents of poverty and abuse.
Resumo:
Left realists contend that people lacking legitimate means of solving the problem of relative deprivation may come into contact with other frustrated disenfranchised people and form subcultures, which in turn, encourage criminal behaviors. Absent from this theory is an attempt to address how, today, subcultural development in North America and elsewhere is heavily shaped simultaneously by the recent destructive consequences of right-wing Friedman or Chicago School economic policies and marginalized men's attempts to live up to the principles of hegemonic masculinity. The purpose of this paper, then, is to offer a new left realist theory that emphasizes the contribution of these two key determinants.
Resumo:
Firms face the challenge of remaining competitive through both entrepreneurial activities and the strategic management of resources. Strategic entrepreneurship around notions of acquiring, bundling and leveraging resources to create value for customers and firm competitive advantage has been studied in relation to large established firms (Hitt et al 2010) but largely overlooked in studies of small and medium enterprises. Recent theorizing regarding the processes by which firms orchestrate resources to create new economic activity (Sirmon et al, 2011) has focused on the managerial capabilities of structuring, bundling and leveraging resources across the firms breadth, depth and lifecycle. This approach offers a potential framework for investigating processes of economic activity and strategic renewal (Agarwal & Helfat, 2009).