Learning from Tabasco’s floods by applying MORT

Natural disasters are increasing alarmingly worldwide in recent years. They have killed millions of people, and adversely affected the life of at least one billion people. Given this, natural disasters present a great challenge to society today concerning how they are to be mitigated so as to produce an acceptable risk is a question which has come to the fore in dramatic ways recently. In 2007, the state of Tabasco, Mexico, was flooded and it is believed that al least one million people were left homeless. The paper addresses the following question: what can be learnt from flood disasters? The paper presents some preliminary results of the analysis of the Tabasco’s flooding by applying the Management Oversight Risk Tree (MORT). The MORT technique may be regarded as a structured checklist in the form of a complex ‘fault-tree’ model that is intended to ensure that all aspects of an organization’s management are looked into when assessing the possible causes of an incident. One of the key conclusions of the present analysis is that the approach to decision making in relation ‘flood management’ at the time of the disaster has not been based explicitly on ‘flood risk assessment’. It is hoped that by conducting such analysis lessons can be learnt so that the impact of natural disasters such as the Tabasco’s flooding can be mitigated in the future.     

Assessment of geochemical modeling applications and research hot spots—a year in review

Environmental Geochemistry and Health - Geochemical modeling has been employed in several fields of science and engineering in recent years. This review seeks to provide an overview of case studies...     

An empirical parametrization of internal seiche amplitude including secondary effects

Environmental Fluid Mechanics - An internal wave is a propagating disturbance within a stable density-stratified fluid. The internal seiche amplitude is often estimated through theories that...     

Solvent-free biodiesel epoxidation

Biodiesel emerged again recently as an alternative for fossil fuels. Besides energy, biodiesel can be used as raw material to synthesize high value products such as epoxides. Indeed, epoxides are versatile intermediates in organic synthesis for numerous reactions due to the high reactivity of the oxirane ring. Actually common epoxidation by peracids in organic solvent can last several hours according to the double bonds number. The solvent confers selectivity to the reaction, preventing di-hydroxylation. Alternatively solvent-free reactions can be done in shorter times, but hydroxylation is less controlled. Here, we set up the synthesis of epoxides from methyl and ethyl esters of waste cooking oil, without solvent or metal catalyst. We tested molar ratio of hydrogen peroxide and formic acid, double bond number, reaction time, and temperature. Results show that the highest epoxide yields and selectivity, with high conversion of the double bonds, were obtained for temperature reactions between 50 and 65 °C, reaction times from 2 to 3 h, and molar ratio of 20/2/1. For those conditions, the double bonds conversion is equal or near 100 %, with epoxide yield and selectivity between 85 and 93 %. Organic solvent suppression, besides being environmentally friendly, also saves reaction time and subsequent purification steps.     

Levels of plasma B-esterases and glutathione-S-transferase activities in three South American toad species

We determined the normal levels of butyrylcholinesterase (BChE), carboxylesterase (CbE), and glutathione S-transferases (GST) activities in three South American toad species in order to establish reference values for field pesticide monitoring purposes. Interspecies variations in B-esterase and GST activities were examined according to body mass. In addition, comparative inhibition of BChE and CbE activities using malaoxon, and chemical reactivation of malaoxon-inhibited BChE activity using pyridine-2-aldoxime methochloride (2-PAM) were investigated. Bufo fernandezae had average activity values for BChE: 17.31 mmol min^?1 ml^?1; CbE: 621.49 nmol min^?1 ml^?1 and GST: 1.94 mmol min^?1 ml^?1 while B. arenarum enzymatic average activities were BChE: 9.51 mmol min^?1 ml^?1; CbE: 270.07 nmol min^?1 ml^?1, and GST: 1.59 mmol min^?1 ml^?1; finally Bufo schneideri had enzymatic mean values of BChE: 2.08 mmol min^?1 ml^?1; CbE: 301.95 nmol min^?1 ml^?1, and GST: 1.60 mmol min^?1 ml^?1. Moreover, we found an allometric relationship between plasma BChE and CbE activities and body size for the three toad species. We suggest that B. fernandezae would be the species with a higher tolerance capacity to organophosphorous insecticides compared to the other toad species, while B. schneideri may be the most vulnerable toad species to field pesticide exposure, although some other factors (e.g., brain AChE sensitivity or pesticide metabolism by phosphotriesterases) should be also taken into account. The malaoxon-inhibited BChE activity of the three toad species was reactivated in the presence of 2-PAM, and it is recommended as a specific and sensitive methodology in the assessment of field exposure to OP insecticides together to compare BChE activity levels between OP-exposed and nonexposed individuals.     

Uneven distribution of urban green spaces in a coastal city in northwest Mexico

ABSTRACT

Extent and distribution of urban green spaces (UGS) in Mazatlan (Mexico) are analysed using remote sensing and GIS techniques. Vegetated areas (2,270?ha), a third of the urban area in 2015, were reclassified into green spaces (GS), urban tree (UT) and open spaces (OS), based in the normalised difference vegetation index, relating them with demographic and socioeconomic data. UGS allocation per capita amount 55?m², mainly represented by the UT class, with the largest patches associated with low developed and very high marginalised areas, and also with very low marginalised sectors, while the lowest allocation correspond to medium and low marginalisation, highly populated sector, without significant correlations. Despite the USG allocation, it is required a better urban planning to maintain public UGS and to protect the local flora, threatened by the introduction of exotic, ornamental species (64% of UT), to guarantee the provision of ecosystem services to the population.     

Drivers and barriers to successful solid waste management: assessing through an aggregated indicator

Journal of Material Cycles and Waste Management - Solid waste management is the main topic of the circular economy and remains a challenge for public management, because despite the recent economic...     

Mitigating energy production-based carbon dioxide emissions in Argentina: the roles of renewable energy and economic globalization

Environmental Science and Pollution Research - The energy sector of Argentina is predominantly reliant on fossil fuels. Consequently, such fossil fuel dependency within the nation’s power...