Modeling population density guided by land use-cover change model: a case study of Bogotá

Population and Environment - Population densities provide valuable spatial information to identify populations at risk, quantify mobility, and improve our understanding of future urban settlements....     

Effect of testosterone therapy on lumbar spine and hip mineral density in elderly men

Objective.?The aim of the present study was to analyse the effect of testosterone therapy on bone mineral density in healthy elderly men who had low levels of total testosterone.

Design.?Randomized, double-blind, placebo-controlled study.

Participants.?Forty-eight men over 60 years old with decreased testosterone levels (≤320 ng/dL) comprised the study. Twenty-five out of 48 received intramuscular injections of testosterone enanthate every three weeks during 12 months; the remaining 23 participants formed the control group. All participants had measurements of bone mineral density (BMD) in both lumbar spine and hip before and at the end of the study as well as testosterone and 17-β estradiol levels.

Results:?Testosterone treated group exhibited a significant (p < 0.05) increment (from 1.198 ± 0.153 to 1.240 ± 0.141 g/cm²) in lumbar BMD in parallel with a significant (p < 0.001) increment (from 301 ± 32 to 471 ± 107 ng/dL) in testosterone concentrations, whereas no significant change occurred in femoral neck BMD.

Conclusions.?Testosterone therapy elicited a positive effect only in lumbar BMD in elderly men with diminished testosterone serum levels.     

A Lean Six Sigma framework for the reduction of ship loading commercial time in the iron ore pelletising industry

Evidence suggests that specifically designed frameworks to implement Lean Six Sigma (LSS) projects to tackle particular problems are more effective than ‘generic’ versions. This paper proposes an implementation framework to effectively deploy LSS to improve a key operation and performance indicator, i.e. ship loading commercial time, of one of the largest world producer of iron ore. This article therefore contributes with a refined framework to effectively implement LSS, and documents its successful application and effectiveness within the context of the case organisation. The LSS framework and project contributed in helping the studied organisation to improve both the capability of its ship loading process and commercial time by more than 30%, resulting in operational savings in the range of $300,000 USD per year. The systematic nature of the framework proposed also helped the organisation to establish a standardised routine to improve its operations. Managerial implications exposing the challenges faced during the implementation of LSS are also discussed to serve as lessons learnt to be considered in other LSS projects. Managers and engineers incharge of improving operations and processes can benefit from this paper as it can be used as a guide to direct the conduction of LSS projects and the empirical application of its principles and tools.     

Lean and green in the transport and logistics sector – a case study of simultaneous deployment

The transport and logistics sector is of vital importance for the stimulation of trade and hence the economic development of nations. However, over the last few years, this sector has taken central stage in the green agenda due to the negative environmental effects derived from its operations. Several disciplines including operations research and sub-areas of supply chain management such as green supply chains, green logistics and reverse logistics have tried to address this problem. However, despite the work undertaken through these disciplines, theoretical or empirical research into the sequential or simultaneous deployment of the lean and green paradigms, particularly, in the road transport and logistics sector is limited. This paper presents a case study where both paradigms have been combined to improve the transport operations of a world leader logistics organisation in the metropolitan area of Monterrey, Mexico. To do this, a systematic methodology and a novel tool called Sustainable Transportation Value Stream Map (STVSM) were proposed. The results obtained from the case study indicate that the concurrent deployment of the green and lean paradigms through such methodology and the STVSM tool is an effective approach to improve both operational efficiency and environmental performance of road transport operations. The paper can be used as a guiding reference for transport and logistics organisations to undertake improvement projects similar to the one presented in this paper. Additionally, this research also intends to stimulate scholarly research into the application of lean and green paradigms in the transport and logistics sector to expand the limited research pursued in this area.     

Some factors associated with Urban-Rural fertility differentials in Mexico

Abstract Warren C. Robinson and others have presented strong evidence that a substantial portion of the variation in urban-rural fertility differentials is attributable to variations in infant and child mortality when the child-woman ratio is the index of fertility. This paper focuses on the contributions of several additional factors in accounting for variations in urban-rural fertility differentials. 1960 census data for 23 urban and rural areas in Mexico are investigated by means of correlation analysis. City growth and literacy differentials are found to be significantly related to the size of the urban-rural fertility (child-woman ratio) differential, but their effect appears to be indirect, and brought about by their association with urban-rural differentials in the sex ratio at the reproductive ages, age at marriage, and the percentage married. The latter three factors are positively related to the size of the urban-rural fertility differential. City growth is inversely related to the magnitude of the fertility differential. This analysis suggests that changes in (urban) population composition may favour higher as well as lower urban fertility and thus affect the size of the urban-rural fertility differential. If this is true, it would appear that urbanization does not necessarily lead to lower total fertility (at least in its early stages), but may lead to the modification of certain demographic characteristics which formerly favoured lower urban fertility. The long-run effects of urbanization are more difficult to assess, but it is suggested that migrants to urban areas may require several generations to manifest lower fertility. This would constitute an additional factor favouring higher urban fertility. The possible contribution of changing mortality conditions is also considered.     

Policy modeling: Definition, classification and evaluation

This paper introduces a definition, a way of classifying and a method of evaluating policy modeling. An analytical tool called “Policy Modeling Consistency (PMC-Index)” has been developed for the purposes of evaluating policy modeling. The PMC-Index enables policy-makers and researchers to identify the level of consistency as well as the strengths and weaknesses within any policy modeling. The implementation of the PMC-Index involves the following four basic steps: (i) the use of multi-input-output table; (ii) classification of variables and identification of parameters; (iii) measurement of the PMC-Index; (iv) construction of the PMC-Surface. Through the PMC-Index, this paper promotes multidisciplinary approach to policy modeling. It suggests that various possible effects of any economic policy can be shown using a multi-dimensional graphical means.     

Beyond the “silo view” of strategic management and corporate governance: evidence from Fiat,Telecom Italia and Unicredit

While corporate governance and strategic management have for a long time suffered from artificial separation and, therefore, generally been tackled in a secluded manner, their combined organizational impact makes them stringently related to one another in the firms’ evolution. In this paper, we argue that, transcending the “silo view” of corporate governance and strategic management, time has come to acknowledge that, depending on circumstances and time periods, within a firm is possible to detect the relative dominance of corporate governance over strategic management, rather than the leadership of strategic management over corporate governance. Drawing on a contingency approach, we dissect the relationships (and the mechanisms that control it) between the strategic function (i.e., which defines the firms’ strategy and supervisions its implementation) and the governance function (i.e., the congruence assessment between the firm strategy selected and the interests of the ownership and of other relevant stakeholders represented in the board of directors and the effectiveness appraisal of the entrepreneurial action). Then, by performing a thorough retrospective qualitative analysis of three relevant case-histories of Italian firms (Fiat, Telecom Italia and Unicredit) operating in three different industries (automobile, banking and telecommunications), we surmise that, either in corporate governance (board) oriented or in strategic management (CEO) oriented companies, the ‘real’ problems arise when the quality of corporate governance or strategic management is poor. Interestingly, we eventually suggest to adopt a value-based approach to the relationship between corporate governance and strategy that may fruitfully complement the contingency perspective taken at the onset of the work.     

Evaluating the impact of lean practices on environmental performance: evidences from five manufacturing companies

Abstract

Previous evidence suggests that lean practices help organizations to enhance environmental performance. However, the impact of lean practices on the environment is still unclear. This study, therefore, aims to analyse the relationship between lean and environmental performance in two main stages: first, a review of the relevant literature was developed, followed by a multiple case study analysis conducted in five manufacturing companies. Onsite data were collected from the firms during a 5 years’ time span of research and developing semi-structured interviews. Findings indicate that the environmental performance of the companies analysed is generally enhanced in the long-term after the implementation of lean. Moreover, the results suggest that the environmental performance of the firms investigated is mainly improved by using JIT and TQM practices in a lean transformation context. The research findings provide further results remarking the possible negative impact of Kanban deliveries, 5S and TPM on various environmental performance indicators.     

The Trade Liberalization Evaluation (TLE) Methodology

This research paper proposes a new trade analysis model to evaluate the trend and stages of trade liberalization of any country. This new trade analysis model is entitled “The Trade Liberalization Evaluation (TLE) Methodology.” The TLE Methodology will introduce new indexes and graphs.There are four basic phases in the implementation of TLE Methodology. The first phase is the design of the multi-input tariff database table by production sector (agriculture, heavy industry,¹ light industry² and services). The second is the measuring of the Trade Liberalization Index by Production Sector (Xi), it is divided by the Agriculture Trade Liberalization Index (X1), Heavy Industry Trade Liberalization Index (X2), Light Industry Trade Liberalization Index (X3), and Services Trade Liberalization Index (X4). The third phase is the measurement of the Area of Coverage of the Trade Liberalization (ACTL) index. The last phase is the measuring of the Trade Liberalization Stage (LTS) index.The general objective of TLE Methodology is to offer policy-makers and researchers a new analytical tool to study the trade liberalization trend and stages of any country from a global perspective—based on a group of indexes and graphs. The TLE Methodology is not intended to be a forecasting model in any case. However, its application is not limited to the study of a special group of countries or regions. It is not constrained by issues about the region or the development stages of any country in a region that is interested in integrating into a Free Trade Area. TLE Methodology, in effect, is a simple and flexible scheme, which can be applied to any case of trade liberalization.     

Barriers in Green Lean implementation: a combined systematic literature review and interpretive structural modelling approach

Green Lean has recently emerged as an alternative strategy for organisations to pursue both operational and sustainability excellence. The interest on this approach has rapidly risen in both academic and industry circles. However, despite this interest, very limited research has focused on its implementation, and no research has investigated the barriers that hinder the success of such activity. This study investigates the Green Lean implementation barriers and their contextual relationships and effects on the integration and deployment of this approach. A Systematic Literature Review (SLR), Interpretative Structural Modelling and fuzzy Matriced’ Impacts Croise’s Multiplication Appliqée a UN Classement (MICMAC) analyses were carried out. Fifteen barriers were extracted from the SLR and then validated in consultation with industry and academic experts. The Interpretive Structural Modelling (ISM) method was used to understand the relationship between the fifteen barriers and to develop a hierarchical model of these. The different barriers were classified into ‘linkage’ and ‘dependent’ barriers by using MICMAC analysis. The results suggested that all the identified barriers play an important role, and hence can equally act as a significant hurdle to the implementation of Green Lean projects. This study can help managers and policy-makers in better understanding these barriers. Thus, they can be assisted in managing and prioritising barriers towards the successful implementation of Green Lean initiatives for better financial and environmental performance.