Molecular and morphological characterization of Colletotrichum gloeosporioides from native Mexican Stylosanthes species

A total of 264 Stylosanthes spp. plants collected from 78 Stylosanthes spp. populations in seven southern Mexican states were analysed for the presence of Colletotrichum spp. Isolates were obtained from 64 plants collected from 36 Stylosanthes populations; 198 isolates produced straight conidia, while 72 isolates produced falcate conidia. Molecular identification was performed to confirm the identity of C. gloeosporioides for the straight-spored isolates. PCR amplifications using the primer CgInt, synthesized from an ITS1 fragment specific to C. gloeosporioides, and the universal primer ITS4 generated the target fragment for 120 Mexican isolates with straight conidia. The endonucleases Ava II and Sma I were used for restriction of the entire amplified ITS1 region of these 120 isolates. The tree constructed from the restriction data grouped 118 Mexican C. gloeosporioides isolates into three clusters containing reference isolates from Africa and Australia, and generated two additional clusters for two Mexican isolates. Conidial shape and growth rate on solid medium were used as the major morphological criteria for distinguishing types A and B. On the basis of 32 other morphological characteristics, a phenogram grouped the colonies into three main clusters. These clusters were partially related to the Stylosanthes species from which they were isolated, and to the molecular groups

An on-road network analysis-based approach to studying driver situation awareness at rail level crossings

Crashes between cars and trains at rail level crossings are problematic worldwide. Despite this, key facets of driver behaviour at rail level crossings, such as situation awareness and decision making, remain ambiguous. This is largely down to the inability of existing methodologies to describe or evaluate the cognitive aspects of driver behaviour when negotiating rail level crossings. This paper showcases an on-road approach for examining driver situation awareness at rail level crossings. The study presented involved participants, classified either as novice or experienced drivers, providing concurrent verbal protocols as they drove a pre-determined urban route incorporating four rail level crossings. Driver situation awareness was modelled using a network analysis-based approach and the structure and content of the networks was assessed. The analysis revealed key differences between novice and experienced drivers situation awareness at rail level crossings. In closing, the benefits of the on-road approach are discussed and a series of wider driver behaviour applications are proposed

Bilancio del biennio 2011-2012

Notiziario della Societ\ue0 Italiana di Infrastrutture Viarie (SIIV) su Le Strad

Walking the talk: Comparing pedestrian ‘activity as imagined’ with ‘activity as done’

The safety of vulnerable road users, including pedestrians, is an important issue worldwide. In line with the shift towards systems thinking in transport safety, the aim of this study was to compare the normal performance of pedestrians as they navigate the road system with that imagined by road system managers to gain insights into how safety management can be improved for this vulnerable road user group. The Event Analysis of Systemic Teamwork framework was used to compare pedestrian activity ‘as imagined’ and ‘as done’ at signalised road intersections and railway level crossings. Data regarding ‘activity as imagined’ was derived from documentation review, and data on ‘activity as done’ was derived from a semi-naturalistic study of ten participants. It is concluded that in both environments pedestrians exhibited more diversity and variability than anticipated by system managers. Insights for improving the design of the road environment for pedestrians are provided. Further, it is argued that wider changes to the processes used in the design and management of road systems are needed.</p