Clustering of concurrent flood risks via Hazard Scenarios

The study of multiple effects of a number of variables, and the assessment of the corresponding environmental risks, may require the adoption of suitable multivariate models when the variables at play are dependent, as it often happens in environmental studies. In this work, the flood risks in a given region are investigated, in order to identify specific spatial sub-regions (clusters) where the floods show a similar behavior with respect to suitable multivariate) criteria. The reason of the work is three-fold, and the outcomes have deep implications in the hydrological practice: (i) such a regionalization (as it is called in hydrology) may provide useful indications for deciding which gauge stations have a similar (stochastic) behavior; (ii) the spatial clustering may represent a valuable tool for investigating ungauged basins present in a given ‘‘homogeneous’’ Region; (iii) the estimate of extreme design values may be improved by using all the observations collected in a cluster (instead of only single-station data). For this purpose, a Copulabased Agglomerative Hierarchical Clustering algorithm – a key tool in geosciences for the analysis of the dependence information – is proposed. The procedure is illustrated via a case study involving the Po river basin, the largest Italian one. A comparison with a previous attempt to cluster the gauge stations present in the same spatial region is also carried out. The sub-regions picked out by the clustering procedure outlined here agree with previous results obtained via heuristic hydrological and meteorological reasonings, and identify spatial areas characterized by similar flood regimes

Towards barcode markers in Fungi: an intron map of Ascomycota mitochondria

<p>Abstract</p> <p>Background</p> <p>A standardized and cost-effective molecular identification system is now an urgent need for Fungi owing to their wide involvement in human life quality. In particular the potential use of mitochondrial DNA species markers has been taken in account. Unfortunately, a serious difficulty in the PCR and bioinformatic surveys is due to the presence of mobile introns in almost all the fungal mitochondrial genes. The aim of this work is to verify the incidence of this phenomenon in Ascomycota, testing, at the same time, a new bioinformatic tool for extracting and managing sequence databases annotations, in order to identify the mitochondrial gene regions where introns are missing so as to propose them as species markers.</p> <p>Methods</p> <p>The general trend towards a large occurrence of introns in the mitochondrial genome of Fungi has been confirmed in Ascomycota by an extensive bioinformatic analysis, performed on all the entries concerning 11 mitochondrial protein coding genes and 2 mitochondrial rRNA (ribosomal RNA) specifying genes, belonging to this phylum, available in public nucleotide sequence databases. A new query approach has been developed to retrieve effectively introns information included in these entries.</p> <p>Results</p> <p>After comparing the new query-based approach with a blast-based procedure, with the aim of designing a faithful Ascomycota mitochondrial intron map, the first method appeared clearly the most accurate. Within this map, despite the large pervasiveness of introns, it is possible to distinguish specific regions comprised in several genes, including the full NADH dehydrogenase subunit 6 (ND6) gene, which could be considered as barcode candidates for Ascomycota due to their paucity of introns and to their length, above 400 bp, comparable to the lower end size of the length range of barcodes successfully used in animals.</p> <p>Conclusion</p> <p>The development of the new query system described here would answer the pressing requirement to improve drastically the bioinformatics support to the DNA Barcode Initiative. The large scale investigation of Ascomycota mitochondrial introns performed through this tool, allowing to exclude the introns-rich sequences from the barcode candidates exploration, could be the first step towards a mitochondrial barcoding strategy for these organisms, similar to the standard approach employed in metazoans.</p

Tacit knowledge and volunteers' empowerment in the fair trade sector

This paper presents the outcome of a fieldwork carried out in France, Italy, Malta and Spain, with the aim of providing evidence about the main features characterizing fair trade organizations and the individuals (in particular volunteers) involved in them. The case studies have been selected taking into consideration both the areas where Fair Trade has deeper roots (as in some French, Italian and Spanish regions) and is more developed, and the areas where the sector is younger, more politically oriented (like Malta and South of Italy). It turns out that Fair Trade mainly attracts women and young people, but by different degrees, leading towards a classification of potential volunteers. However, there are some skills that emerge across all the groups, such as relational tem-working skills

Fair Trade: the creation of new knowledge in a sector characterized by positive externalities in both developing and industrialized countries

The authors define Fair Trade sector and competences from an economic perspective. The competence is the result of a process of elaboration, exploitation and use of individual and social resources. This result depends on the capabilities to transform such resources in functionings. The individual has material and immaterial resources at disposal, which include personal characteristics of the worker, background, ability, interests, behaviour and the specific functional connection between the individual and the resources. The paper draws on motivations and values, which support the activity of the individual in the Fair Trade Organization (FTO). The tasks performed in the FTO puts in evidence experiences of informal learning through learning-by-doing, learning-by-interacting, learning-by-using. In synthesis, applying this approach, it is possible to give evidence that the acquisition of competences also depends on motivation, behaviour, time and quality of time spent in FTO and on the kind of structure where the volunteer works

A New Penetrometric Test for in Situ Mechanical Characterization of Historic Mortar: Preliminary Results on Different Hydrated Lime Mortar Specimens

Some existing non-destructive tools are used to characterize on site the lime-based mortar of historical buildings from a mechanical point of view. Those devices are not only based on the surface hardness but are able to inspect the mortar joints up to a few millimeters depth. Historical mortar joints are normally too thin to extract representative samples for mechanical characterization and often too weak and without sufficient cohesion, due to a hard significant surface decay. Mortar “sanding” in historic building (lack of cohesion in bedding mortar, reducing it to grains) can penetrate from 20 to 40 mm, without compromising the overall masonry mechanical behavior. This makes it difficult to obtain reliable data on their real consistency. A new device has been realized to analyze in situ mortar joints, adapting the rebound hammer with a pointy probe (conical tip, 4mm diameter) and able to reach a depth of penetration of 60-70 mm inside the test specimen. The system is based on the automated measurement of the penetration rate at each hammer blow, allowing to discriminate the effect of the most degraded and powdered external mortar. Thanks to a lowcost electronic data acquisition system connected to the hammer, all measurements carried out on site are recorded and made available for processing. The paper presents a first series of preliminary laboratory tests on different samples of lime mortar made ad hoc for a Round Robin Test. Two different methods were compared on laboratory samples of known compressive strength: static and dynamic penetrometric tests, correlated with the compressive strength obtained in the laboratory and supplied by another university. The resulting correlation between the two methods was promising enough to start a first experience on a historic building where previous diagnostic investigations were carried out and a stratification of mortar joints was detected

Fair Trade: the Creation of New Knowledge in a Sector Characterized by Positive Externalities in both Developing and Industrialized Countries

The authors define Fair Trade sector and competences from an economic perspective. The competence is the result of a process of elaboration, exploitation and use of individual and social resources. This result depends on the capabilities to transform such resources in functionings. The individual has material and immaterial resources at disposal, which include personal characteristics of the worker, background, ability, interests, behaviour and the specific functional connection between the individual and the resources. The paper draws on motivations and values, which support the activity of the individual in the Fair Trade Organization (FTO). The tasks performed in the FTO puts in evidence experiences of informal learning through learning-by-doing, learning-by-interacting, learning-by-using. In synthesis, applying this approach, it is possible to give evidence that the acquisition of competences also depends on motivation, behaviour, time and quality of time spent in FTO and on the kind of structure where the volunteer works

Quantification of the environmental structural risk with spoiling ties: is randomization worthwhile?

Many recent works show that copulas turn out to be useful in a variety of different applications, especially in environmental sciences. Here the variables of interest are usually continuous, being times, lengths, weights, and so on. Unfortunately, the corresponding observations may suffer from (instrumental) adjustments and truncations, and eventually may show several repeated values (i.e., ties). In turn, on the one hand, a tricky issue of identifiability of the model arises, and, on the other hand, the assessment of the risk may be adversely affected. A possible remedy is to adopt suitable randomization procedures: here three diffe ent strategies are outlined. The goal of the work is to carry out a simulation study in order to evaluate the effects of the randomization of multivariate observations when ties are present. In particular, it will be investigated whether, how, and to what extent, the randomization may change the estimation of the structural risk: for this purpose, a coastal engineering example will be used, as archetypical of a broad class of models and problems in engineering applications. Practical advices and warnings about the use of randomization techniques are hence given

Spin-off Extreme Value and Archimedean copulas for estimating the bivariate structural risk

In environmental applications, the estimation of the structural risk is fundamental. Beside the knowledge of the physical response of the structure to the loads of interest, a statistical model for the behavior of the input variables is generally required, possibly accounting for the fact that these variables are usually non-independent. For this purpose, a multivariate approach based on copulas is adopted in this paper. In particular, the following classes of dependence structures are often used in practice: the Extreme Value copulas, and the Archimedean copulas. However, how to properly select a suitable Extreme Value or Archimedean copula is a problem open to many solutions. As a viable one, this work shows how two semi-parametric approximations to, respectively, Extreme Value and Archimedean copulas, can be used in order to circumvent the troublesome selection issue in the estimation of the structural risk. Suitable simulation studies are performed, in order to check and evaluate the performance of the approximating techniques introduced in this work