Mechanical resistance properties of gravel used in subsurface flow constructed wetlands: implications for clogging

Gravel constitutes the filter medium in subsurface flow constructed wetlands (SSF CWs) and its porosity and hydraulic conductivity decrease over time (clogging), limiting the lifespan of the systems. Using gravel of poor quality accelerates clogging in wetlands. In this study, gravel samples from six different wetland systems were compared with regards to their mineral composition and mechanical resistance properties. Results showed that both mineralogy and texture are related to mechanical resistance. Accordingly, gravel with high content of quartz (> 80%) showed a lower percentage of broken particles (0.18-1.03%) than those with lower content of quartz (2.42-4.56% media broken). Although granite is formed by high durability minerals, its non-uniform texture results in a lower resistance to abrasion (ca. 10% less resistance than calcareous gravel). Therefore, it is recommended to use gravels composed mainly of quartz or, when it is not available, limestone gravels (rounded and uniform) are recommended instead. The resistance to abrasion (LAA test) seems to be a good indicator to determine the mechanical properties of gravels used in CWs. It is recommended to use gravels with LAA below 30% in order to avoid a rapid clogging due to gravel crumbling and subsequent mineral solids accumulation.     

Deposit insurance and bank risk-taking: Evidence from internal loan ratings

We analyze the effect of deposit insurance on the risk-taking behavior of banks in the context of a quasi-natural experiment using detailed credit registry data. Using the case of an emerging economy, Bolivia, which introduced a deposit insurance system during the sample period, we compare the risk-taking behavior of banks before and after the introduction of this system. We find that in the post-deposit insurance period, banks are more likely to initiate riskier loans (i.e., loans with worse internal ratings at origination). These loans carry higher interest rates and are associated with worse ex-post performance (i.e., they have higher default and delinquency rates). Banks do not seem to compensate for the extra risk by increasing collateral requirements or decreasing loan maturities. We also find evidence that the increase in risk-taking is due to the decrease in market discipline from large depositors. Finally, differences between large (too-big-to-fail) and small banks diminished in the post-deposit insurance period.     

The transition from products to solutions: External business model fit and dynamics

This article provides empirical evidence and contributes to theory building concerning business model fit and dynamics in the area of solutions business. Business models are seen in this context as going beyond considerations such as offerings and internal processes or even relationships, and as including network and market considerations. Indeed the paper highlights the fact that a business model is not firm-focused, nor dyad-focused, but rather network-, and even market-focused, demonstrating that a business model is not static, but dynamic. Manufacturer and customer continuously shift form and content of their respective business models to adapt both to the needs of the counterpart and to market context. A qualitative case study approach is adopted, with subsequent content analysis. The case study relates to the aerospace industry with focus on a complex engineering firm, one of the largest aircraft manufacturers in the world, its customer — a national airline — and their network partners of various kinds. The data were collected through multiple face-to-face interviews with managers in both companies, as a part and parcel of a network of actors that influences and is influenced by the supplier–buyer relationship. Relationships over time between these firms and network partners are described, highlighting the interplay of products and services related to the provision of solutions. Findings highlight the dynamic nature of business models over the relationship lifecycle between supplier and customer in a complex engineering environment, and the need for reciprocal adjustment of models.     

Bank Disclosure and Market Assessment of Financial Fragility: Evidence from Turkish Banks’ Equity Prices

In this paper we explore whether Turkish banks with worsening indicators of financial fragility were subject to market monitoring during the years leading to the 2000/2001 crisis, and how the quality and timeliness of the disclosure affect market reaction. We find that shareholders reacted negatively to indicators of financial fragility such as increases in maturity mismatches, currency mismatches, and non-performing loans, showing shareholders’ concerns about the impact of financial fragility indicators on future profits. We also find that audited statements that show larger reporting lags, are not informative, pointing to the need of improving their timeliness. Finally, our study suggests that the finding that securities prices react to financial fragility indicators should not be taken as sufficient evidence of banks’ safety and soundness.     

Resting cladoceran eggs and their contribution to zooplankton diversity in a lagoon of the Upper Paraná River floodplain

Zooplankton produce resting eggs and diapause stages as strategies to promote their survival during periods of adverse environmental conditions, thereby ensuring the community diversity. The goal of this study is to investigate the contribution of these eggs, which were present in the sediment of an isolated lagoon in the Upper Paraná River floodplain, to cladoceran diversity. The species hatching from the resting eggs in the sediment do not occur in the plankton. Sediment samples were collected at six sampling sites in the Osmar Lagoon banks, in September 2004 and June, July, August and September 2005. Zooplankton were sampled in the pelagic region, using a motorized pump (1000 L) and plankton net (68 µm). The pH, water temperature (°C), electrical conductivity (µS cm⁻¹) and dissolved oxygen concentration (mg L⁻¹) also were measured. The resting eggs were counted in the laboratory, being maintained under constant temperature and photoperiod until their analyses. The resting eggs were examined daily until hatching. A higher abundance of these eggs was observed in July, during a period of lower temperature and electrical conductivity, and higher pH and dissolved oxygen concentrations. ANOVA results indicated significant differences in resting egg abundance among the sampling months. Ceriodaphnia reticulata, Macrothrix spinosa, Ilyocryptus spinifer, Ephemeroporus tridentatus and Diaphanosoma sp. hatched from the resting eggs, although they were not observed in the plankton samples. C. reticulata was observed for the first time in this floodplain, with these study results corroborating the hypothesis that resting cladoceran eggs do contribute to zooplankton diversity in the lagoon.     

Rio 2016 and the sport participation legacies

The aim of this study was to investigate the perceptions held by physical education professionals of the sport participation legacy associated with the 2016 Olympic Games (Rio 2016). Semi-structured interviews were conducted with 24 professionals who resided in Rio de Janeiro at the time of the study. In general, apart from the tangible legacies, individuals were completely unaware of what is being proposed by the different levels of government and the organising committee to maximise the potential benefits of the event for the local community. According to participants, the local population was never consulted about, or properly informed of, what was involved in staging the event and its planned legacies. The perceptions of post-Games changes in sport participation, using the 2007 Rio de Janeiro Pan-American Games as a point of comparison, ranged from no impact to a short-term increase. The reason for this, according to participants, was the lack of long-term planning and policies to encourage and promote sport participation. In conclusion, in order for benefits of mega events to be leveraged, the different levels of government need to develop long-term actions and policies to encourage sports participation in conjunction with the employment of the infrastructural legacy towards this end.     

Portfolio management with tail dependence

Many publications, that treated with Portfolio Management, were devastating for all asset allocation models in the context of portfolios. The elimination of extreme events (asymmetric or tail dependence) during the portfolio construction process can reduce the skills of asset managers to reduce risk through diversification. The copula theory allows us to calculate an alternative to measure the dependence of extreme events in assets through the index lower tail dependence. We check that the strategies with tail dependence overcame Talmud rule, the Markowitz model and the model of Tu and Zhou by simulating 1,000 portfolios with 3, 5, 10 and 20 randomly selected assets from DJIA for the period 03/1990 until 12/2016. We conclude that models of tail dependence and Markowitz had more performance ex-ante than Talmud and the Tu and Zhou model for portfolios with 3, 5, 10 and 20 assets. Tail dependence models overcome Markowitz, in terms of cumulative return, in over 60% of months considered in the analysis. The results indicate that the Talmud rule should be discarded in a context of constructing portfolios with individual stocks ahead strategies with tail dependence.     

Lending to small businesses: the role of loan maturity in addressing information problems

We investigate what determines the maturity of lines of credit to small businesses. Our results provide strong support for the hypothesis that shorter loan maturities serve to mitigate the problems associated with borrower risk and asymmetric information that are typical of small business lending. We find that maturity is shorter for firm owners that have poor credit histories, are older, and less experienced, and for firms that are more informationally opaque. Supporting the notion that collateral and maturity are substitute mechanisms in mitigating agency problems, we also find strong evidence that maturity increases with collateral pledges, that personal collateral is associated with longer maturities than business collateral, and that collateral types that better mitigate agency problems reduce the sensitivity of loan maturity to informational asymmetries and risk. Finally, while it is argued that relationship lending may mitigate information asymmetry, we find no relation between loan maturity and stronger firm-creditor ties.

Heterogeneity,saving-investment dynamics and capital mobility in Latin America

The purpose of this paper is to analyze the dynamics of national saving-investment relationship in order to determine the degree of capital mobility in 12 Latin American countries. The analytically relevant correlation is the short-term one, defined as that between changes in saving and investment. Of special interest is the speed at which variables return to the long run equilibrium relationship, which is interpreted as being negatively related to the degree of capital mobility. The long run correlation, in turn, captures the coefficient implied by the solvency constraint. We find that heterogeneity and cross-section dependence completely change the estimation of the long run coefficient. Besides we obtain a more precise short run coefficient estimate compared to the existent estimates in the literature. There is evidence of an intermediate degree of capital mobility, and the coefficients are extremely stable over time.