Preventive activity in the greenhouse-construction industry of south-eastern Spain

Preventive action in companies is one of the bases of ergonomic intervention. Therefore, in the present work, the preventive activity of greenhouse-construction companies in south-eastern Spain is characterized. A sample was taken by means of a questionnaire structured in four groups of variables: general characteristics of the company, characteristics of safety and health in the construction procedures, characteristics of prevention and management in safety and health, and characteristics of the coordination during the execution of the work. The results indicate that the prevention is very poor, not adopting any preventive-management model for internationally recognized work hazards so that the information and training in preventive matters of companies and workers is insufficient. In addition, the companies have been classified into three clusters, correlating the company size and prevention management of labour hazards, revealing that the companies with higher gross income and number of workers showed better prevention management.     

A design of experiments for statistically predicting risk of adverse health effects on drivers exposed to vertical vibrations

An injury risk factor (IRF), which indicates the risk of adverse health effect to lumbar rachis arising from mechanical vibrations, is developed. Experiments have been conducted that consider acceleration levels at the seat of drivers, posture, morphology, density, damping rate and body mass as independent variables. A parametric finite-element model of the lumbar rachis has been generated. It is shown that the IRF increases with ageing and an IRF of 30% is proposed as a threshold for fatigue purposes. This level is reached if a peak acceleration level greater than 3 m/s2 is applied to a light (55 kg) and an old driver with a low bone density and a damping rate of 20%. This vibration threshold must be reduced to 2.7 m/s2 if the driver?s weight increases to 75 kg and to 2 m/s2 if the driver is heavy (98 kg).     

Geomorphological consequences of fraquent and infrequent rainfall and hydrological events in Pyrennez Mountains of Spain

Various aspects of pluviometric andhydrological events have been studiedworldwide, one of which is the geomorphichazards as the intensity of the eventsexceeds various geomorphic thresholds.During the last few years, rainstorms ofdifferent intensities have occurred in theCentral Spanish Pyrenees, including one ofexceptional character. Large, historicaldebris flows have been studied, as well asthe actual sediment transport in smallexperimental catchments. This study showsthat during the most frequent eventssuspended sediment transport is the commongeomorphic process. Bedload is mobilizedseveral times per year while small rockavalanches and channelized debris flowshave a return period of at least 5 years.Hillslope debris flows are triggered byrainfall events with a 25–30 year returnperiod. Reactivation of large, deep massmovements is linked to rainfalls of around100 year return period (between 130 and160 mm in 24 hours). Catastrophicgeomorphic processes occur whenprecipitation exceeds a 100 year returnperiod, as was the case of the Biescascampsite disaster. Geomorphic processestriggered by intense rainfall events havecaused major damage and human disastersbut the hazards have been reduced by theintroduction of several control measures,including reforestation, the constructionof check-dams, canalization of riversegments and improved flood forecasting.     

Climate change is predicted to negatively influence Moroccan endemic reptile richness. Implications for conservation in protected areas

The identification of species-rich areas and their prognosticated turnover under climate change are crucial for the conservation of endemic taxa. This study aims to identify areas of reptile endemicity richness in a global biodiversity hot spot (Morocco) under current and future climatic conditions and to investigate the role of protected areas in biodiversity conservation under climate change. Species distribution models (SDM) were performed over the distribution of 21 endemic reptiles, combined to estimate current species richness at 1?×?1 km resolution and projected to years 2050 and 2080 according to distinct story lines and ensemble global circulation models, assuming unlimited and null dispersion ability. Generalized additive models were performed between species richness and geographic characteristics of 43 protected areas. SDM found precipitation as the most important factor related to current species distributions. Important reductions in future suitable areas were predicted for 50 % of species, and four species were identified as highly vulnerable to extinction. Drastic reductions in species-rich areas were predicted for the future, with considerable variability between years and dispersal scenarios. High turnover rates of species composition were predicted for eastern Morocco, whereas low values were forecasted for the Northern Atlantic coast and mountains. Species richness for current and future conditions was significantly related to the altitude and latitude of protected areas. Protected areas located in mountains and/or in the Northern Atlantic coast were identified as refugia, where population monitoring and conservation management is needed.

     

Diel periodicity of pheromone release by females of Planococcus citri and Planococcus ficus and the temporal flight activity of their conspecific males

The diel periodicity of sex pheromone release was monitored in two mealybug species, Planococcus citri and Planococcus ficus (Hemiptera; Pseudococcidae), using sequential SPME/GCMS analysis. A maximal release of 2 ng/h pheromone by 9–12-day-old P. citri females occurred 1–2 h before the beginning of photophase. The highest release of pheromone by P. ficus females was 1–2 ng/2 h of 10–20-day-old females, approximately 2 h after the beginning of photophase. Mating resulted in termination of the pheromone release in both mealybug species. The temporal flight activity of the males was monitored in rearing chambers using pheromone baited delta traps. Males of both P. citri and P. ficus displayed the same flight pattern and began flying at 06:00 hours when the light was turned on, reaching a peak during the first and second hour of the photophase. Our results suggest that other biparental mealybug species display also diel periodicities of maximal pheromone release and response. Direct evaluation of the diel periodicity of the pheromone release by the automatic sequential analysis is convenient and will be very helpful in optimizing the airborne collection and identification of other unknown mealybug pheromones and to study the calling behavior of females. Considering this behavior pattern may help to develop more effective pheromone-based management strategies against mealybugs.     

Evaluation of the effectiveness of horizontal subsurface flow constructed wetlands for different media

Two media bed (gravel and Filtralite NR) were tested in a mesocosm to evaluate the removal of organic matter (as chemical oxygen demand (COD)),ammonia (NH4-N),nitrite,nitrate and solid matter (as total suspended solids (TSS)) for a synthetic wastewater (acetate-based) and a domestic wastewater.The use of Filtralite allowed average removal rates (6–16.8 g COD/(m2·day),0.8–1.1 g NH4-N/(m2·day) and 3.1 g TSS/(m2·day)) and removal effciencies (65%–93%,57%–85% and 78% for COD,NH4-N and TSS,respectively),higher than that observed in the experiments with gravel.The applied loads of COD,ammonia,nitrate and TSS seem to influence the respective removal rates but only for the treatment of domestic wastewater with higher correlation coefficients for Filtralite.Regardless the type of media bed and the type of wastewater,nitrate was completely removed for nitrogen loading rates up to 1.3 g NO3-N/(m2·day).There was no evidence of the influence of nitrate loads on the removal of organic matter.     

Molecular structures and associations of humic substances in the terrestrial environment

Here we show, for the first time, evidence of the primary molecular structures in humic substances (HS), the most abundant naturally occurring organic molecules on Earth, and their associations as mixtures in terrestrial systems. Multi-dimensional nuclear magnetic resonance (NMR) experiments show us that the major molecular structural components in the mixtures operationally defined as HS are aliphatic acids, ethers, esters and alcohols; aromatic lignin derived fragments; polysaccharides and polypeptides. By means of diffusion ordered spectroscopy, distinct diffusion coefficients consistent with relatively low molecular weight molecules were observed for all the components in the mixtures, and saccharides were the largest single class of component present. Liquid chromatography NMR confirmed that HS components can be easily separated and nuclear Overhauser effect (NOE) enhancements support the finding that the components are of relatively low molecular weight <~2,000 Da. The widely recognized properties of HS, i.e., characteristics indicative of crosslinked, macromolecular networks, can now be explained as aggregation of mixtures, most likely instigated by complexation with metal cations.     

A review of postfeeding larval dispersal in blowflies: implications for forensic entomology

Immature and adult stages of blowflies are one of the primary invertebrate consumers of decomposing animal organic matter. When the food supply is consumed or when the larvae complete their development and migrate prior to the total removal of the larval substrate, they disperse to find adequate places for pupation, a process known as postfeeding larval dispersal. Several important ecological and physiological aspects of this process were studied since the work by Green (Ann Appl Biol 38:475, 1951) 50 years ago. An understanding of postfeeding larval dispersal can be useful for determining the postmortem interval (PMI) of human cadavers in legal medicine, particularly because this interval may be underestimated if older dispersing larvae or those that disperse longer, faster, and deeper are not taken into account. In this article, we review the process of postfeeding larval dispersal and its implications for legal medicine, in particular showing that aspects such as burial behavior and competition among species of blowflies can influence this process and consequently, the estimation of PMI.     

Linking empowering leadership to safety participation in nuclear power plants: A structural equation model

IntroductionSafety participation is of paramount importance in guaranteeing the safe running of nuclear power plants.MethodThe present study examined the effects of empowering leadership on safety participation.ResultsBased on a sample of 495 employees from two Spanish nuclear power plants, structural equation modeling showed that empowering leadership has a significant relationship with safety participation, which is mediated by collaborative team learning. In addition, the results revealed that the relationship between empowering leadership and collaborative learning is partially mediated by the promotion of dialogue and open communication.ConclusionsThe implications of these findings for safety research and their practical applications are outlined.Impact on IndustryAn empowering leadership style enhances workers' safety performance, particularly safety participation behaviors. Safety participation is recommended to detect possible rule inconsistencies or misunderstood procedures and make workers aware of critical safety information and issues.