Safety I–II,resilience and antifragility engineering: a debate explained through an accident occurring on a mobile elevating work platform

Occupational health and safety (OHS) represents an important field of exploration for the research community: in spite of the growth of technological innovations, the increasing complexity of systems involves critical issues in terms of degradation of the safety levels. In such a situation, new safety management approaches are now mandatory in order to face the safety implications of the current technological evolutions. Along these lines, performing risk-based analysis alone seems not to be enough anymore. The evaluation of robustness, antifragility and resilience of a socio-technical system is now indispensable in order to face unforeseen events. This article will briefly introduce the topics of Safety I and Safety II, resilience engineering and antifragility engineering, explaining correlations, overlapping aspects and synergies. Secondly, the article will discuss the applications of those paradigms to a real accident, highlighting how they can challenge, stimulate and inspire research for improving OHS conditions.     

Density,size structure and aspergillosis prevalence in <Emphasis Type="Italic">Gorgonia ventalina</Emphasis> at six localities in Puerto Rico

Gorgonia ventalina’s density, size structure and lesion prevalence was measured at six sites in Puerto Rico that exhibited variation in horizontal water transparency, sedimentation rates, suspended particle matter, scleractinian and macroalgal cover. G. ventalina density varied significantly among sites (between 0.84 and 0.007 colonies/m²), and was positively correlated with water transparency. Size structure did not vary much among sites, and reflects high mortality among the smaller size classes and high survivorship in large colonies. Prevalence of active fungi-induced lesions (type I) did not vary significantly among sites and was density-independent. However, prevalence of old lesions of unknown origin (type II) did vary among reefs and was negatively correlated with water transparency. Prevalence of types I or II lesions was independent of colony size. Our results suggest that (1) turbidity and sedimentation are important abiotic factors controlling the abundance of sea fans, (2) variation in settlement success and early survivorship of recruits has more impact on the sea fan populations than variation in the survivorship of large colonies and (3) prevalence of aspergillosis (type I) at the studied sites is similar to that reported for other Caribbean reefs and supports the epizootic nature of the disease and (4) lesions with exposed skeleton are more likely to be colonized by fouling organisms at impacted reefs. The combined effects of anthropogenic impacts and aspergillosis may cause local extinctions of sea fans, as is becoming evident in many reefs in Puerto Rico.     

Physiological capacity and environmental tolerance in two sandhopper species with contrasting geographical ranges: Talitrus saltator and Talorchestia ugolinii

We investigated the physiological plasticity and environmental tolerance of two phylogenetically closely related, ecologically similar and co-occurring species of supralittoral amphipods differing drastically in the size of their geographical ranges. A series of physiological traits were characterised for the Corsican-endemic Talorchestia ugolinii Bella-Santini and Ruffo and the widespread Talitrus saltator Montagu. The effect of body mass, temperature and salinity on heart rate (used as proxy for metabolic activity and stress), the effect of temperature on oxygen consumption and the tolerance to salinity exposure were investigated in both species, together with the characterisation of haemolymph osmoregulation in T. ugolinii. Our results showed that there is a clear difference in the resting metabolic rates and physiological capacity, as well as environmental tolerance, between T. saltator and T. ugolinii, with T. saltator overall showing a broader physiological niche. Although T. ugolinii showed a relatively good ability to regulate its haemolymph osmotic concentration (similar to that previously described for T. saltator), it demonstrated a lower tolerance to exposure to hypo-osmotic stress. In addition, a consistent picture emerged between the ability to control the cardiac function and the capacity to actively respond to osmotic stress. The physiological findings are discussed in relation to the known ecology and geographical distribution of T. ugolinii.     

Chemistry of the postpharyngeal gland secretion and its implication for the phylogeny of IberianCataglyphis species (Hymenoptera: Formicidae)

Summary A comparative morphological and chemical study of six endemic species ofCataglyphis from the Iberian Peninsula:C. ibericus, C. rosenhaueri, C. hispanicus, C. humeya, C. velox andC. floricola and the Moroccan speciesC. bombycinus is described. The morphological study relied primarily on genitalia characteristics, whereas the chemical study concentrated on the postpharyngeal gland constituents. Cladograms based on the morphological and chemical data were performed using Ward's method. The dendrogram based on morphological features revealed that the IberianCataglyphis can be classified into three species groupsalbicans, altisquamis andemmae. The same pattern occurred when the dimethylalkanes constituents of the postpharyngeal gland were utilised as character states, with a slight displacement of species within thealtisquamis group. However, when the complete hydrocarbon blend was utilised major discrepancies in the dendrograms occurred.Cataglyphis velox proved to be very similar toC. bombycinus, whereasC. floricola clustered with the other two species of thealtisquamis group. Based on the geographical distribution and paleontological data (Tinaut 1993) it is assumed thatC. floricola recently invaded the Iberian Peninsula. Based on the chemical findings we postulate that chemical character displacement occurred inC. floricola as a result of its sympatry withC. velox after the former colonized the Iberian Peninsula. We further discuss the possible reason for the different dendrograms obtained when only the dimethylalkanes are considered and its implication for the communicative role of the postpharyngeal gland secretion in these ants.     

Trace element concentration in tree-rings biomonitoring centuries of environmental change

Inductively coupled plasma mass spectrometry (ICP-MS) was used to examine trace element concentration in tree-rings over three and half centuries to assess macro-trends of environmental change. Tree-rings of a 350+ year old mammoth ponderosa pine (Pinus ponderosa) were analyzed for element concentration and evaluated versus local and global historical events. The ponderosa pine was located 100 miles south of the Canada/USA border and 180 miles east of the Pacific Ocean, and grew near apple orchards, a public road, and Swakane Creek in western Washington, USA. The elements tested did not all display the same time versus concentration patterns. Copper and chromium displayed cyclic concentration patterns over the last 350+ years, which appear to be associated with local events. Strontium, barium, zinc and cadmium were found to be relatively constant between the mid 1600s and the early 1800s. Strontium, barium, zinc, and cadmium then increased beginning in the early 1800s for approximately 50 years then decreased to present day 2000. Significantly, similar changes seen in Ca, Mg, and Zn in other studies have been attributed to acid rain, whereas, in our study area there is no history of anthropogenic acid rain. Most importantly, our data goes back to the mid-1600s several hundred years further back than most other studies of this nature. This additional time data provides for a better context of trend data not previously available.     

Analysis of heavy metal distribution in superficial estuarine sediments (estuary of Bilbao, Basque Country) by open-focused microwave-assisted extraction and ICP-OES

Open-focused microwave-assisted extraction and ICP-OES determination of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn from surface sediments of the estuary of Bilbao (Basque Country, North of Spain) was carried out. All the samples were collected at three different tributaries of the estuary (Asua, Galindo and Nerbioi-Ibaizabal) every two months during 1999. The digestion procedure was proposed from the conclusions of a fractionated factorial design, and the precision and accuracy of the method was verified using a certified reference sediment (RTC008-050). The results of the analysis were statistically treated by means of principal component analysis and correlation analysis. The principal component analysis of sediment data (32 samples × 9 metals) indicated different patterns of contamination regarding the tributary and sampling station. The two main patterns observed were a steady increment of the metal concentration along all the campaigns in the samples collected in the Galindo River and a seasonal variation in the Nerbioi-Ibaizabal River, with higher metallic content during summertime and lower content during wintertime.     

Improvements in mixing operations of water treatment plants by use of a stable finite element model.

This work shows improvements made in mixing operations at water treatment plants, as a result of the hydrodynamic analysis of the mixing processes carried out by the use of a Finite Element Model. The code, developed in the Civil Engineering Department of the University of La Coru?a, Spain, solves the Navier-Stokes equations that rule viscous incompressible flow by using a Streamline Upwind/Petrov-Galerkin (SUPG) stabilization technique. The incorporation of the SUPG formulation leads to obtaining stable solutions for Reynolds numbers of a moderate order in connection with meshes that are not very refined. Some water treatment units present significant deficiencies in their design. The numerical evaluation of the flow avoids the high expenses of the trial-and-error processes involved in installing and removing the mixing mechanisms and those derived from the need to halt the water treatment processes. As a result, an optimum design of the treatment plant is obtained at a low cost.     

Influence of air pollution on the incidence of respiratory tract neoplasm

To evaluate the possible influence of air pollutants on the incidence of respiratory tract neoplasm we studied 12 S?o Paulo City districts where air pollution is observed. We collected data on pollutants from 1981-1990 and correlated it with the incidence of larynx and lung neoplasms in 1997. Ozone was the pollutant that best correlated with the incidence of neoplasm. The correlation coefficients were 0.7234 (p=0.277) and 0.9929 (p=0.007) for lung and larynx cancer, respectively. There may be a relationship between air pollution and the incidence of respiratory tract neoplasm. This study, however, does not allow us to conclude that there is a causal relationship.