A study was conducted to investigate phenotypic and genotypic changes within Pythium aphanidermatum populations during the period 2006 to 2011. In total, 92 isolates of P. aphanidermatum (59 in 2006 and 33 in 2011) were obtained from different planting sites (soil) of cucumber from a single greenhouse. Generated sequences of the internal transcribed spacer (ITS) ribosomal DNA showed that all, except one isolate, share an identical sequence of the ITS region. Most (89%) P. aphanidermatum isolates were found to be aggressive on cucumber seedlings, with no significant differences in the aggressiveness level between populations obtained from different planting rows or different years. Sensitivity to metalaxyl among populations of P. aphanidermatum increased significantly from concentration resulting in 50% growth inhibition levels of 0.070 to 1.823 (average 0.824 μg ml–1) in 2006 to 0.002 to 0.564 (average 0.160 μg ml–1) in 2011. Amplified fragment length polymorphism analysis of the 92 isolates produced 92 different genotypes and 985 polymorphic loci. P. aphanidermatum populations from 2006 and 2011 were found to have low levels of genetic diversity (H = 0.1425), which implies introduction of the isolates into the greenhouse via common sources. Results from analysis of molecular variance (FST = 0.0307 in 2006 and 0.0222 in 2011) provided evidence for frequent exchange of Pythium inoculum between different planting locations within the same year. However, the analysis showed moderate levels (FST = 0.1731) of genetic differentiation among populations from the 2 years. This was supported by unweighted pair group method with arithmetic means analysis, which showed clustering of many of the 2006 isolates in separate clusters. The change in the metalaxyl sensitivity of the populations from 2006 to 2011 accompanied by the genetic differences among these two populations may suggest that many of the isolates from 2006 were lost and were replaced by new and highly sensitive P. aphanidermatum isolates by 2011.

Bronchogenic cysts originate from abnormal budding of the tracheal diverticula during the embryological period. Inaccuracy in the process of growing of the ventral foregut will give rise to bronchogenic cyst. Scapular bronchogenic cyst is an extremely rare form of this anomaly. A three years old boy suffered for 2 years with left sided suprascapular cystic lesion which was gradually increasing in size. The swelling was 4 × 3 cm in size and non tender. The cyst was evaluated by CT scan that showed complex cystic lesion over the left scapular spine. Total excision of the cyst was done and histopathology showed cutaneous bronchogenic cyst. The proposed mechanism for such cutaneous lesion is that the accessory buds from the tracheobronchial tree/primitive foregut migrated from the thorax in an aberrant manner to lie in periscapular positions. The definitive treatment of scapular lesions is total surgical excision. The final diagnosis is based on the histopathological findings in the majority of cases.

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PurposeThe purpose of this study is to propose a conceptual model for managing supply risk (SR) dependencies in regional supply networks (SNs). Grounded on resource dependency theory (RDT), the research conceptualises the management of SR as buffering and bridging strategies that enable organisations to redefine their SN to cope with SR and as a three-stage transformation mechanism.Design/methodology/approachFour supply failure case studies from the aluminium and the oil and gas industries in the Gulf Cooperation Council (GCC) region inductively provide empirical insights for a revised conceptual framing. Within and cross case analysis on transcribed semi-structured interviews with 11 SN managers focus on the SRs and dependencies associated with the supply failures and an abstraction of risk management (RM) strategies for coping with these failures.FindingsThe analysis finds that underpinning ‘second-order’ buffering and bridging strategies from RDT are four main ‘first-order’ RM strategies: unit independency, organisational adaptation, network reconfiguration and environmental acceptance. These RM strategies are due to controllability and predictability levels that influence investment in RM and reflect the locations for implementing RM practices, i.e. the business unit, the organisation, the SN and the environment.Originality/valueThe article contributes to research through the conceptual framework of SR dependencies and unique insights on SR management within the GCC region. Practically, the research is novel in offering strategic directions for RM evaluations and investments that reflect the controllability and predictability of risk incidents. Such evaluations are potentially valuable in orchestrating regional SNs, for managing GCC companies in global supply chains, and for strategic decisions to expand or outsource to the GCC region.

A study was conducted to characterize the common Pythium spp. in greenhouses in Oman and their level of resistance to hymexazol, a widely used fungicide in the country. Pythium isolates were obtained from soil samples, cocopeat bags, and cucumber roots collected from seven regions in the country. Identification of 80 Pythium isolates to the species level using sequences of the internal transcribed spacer region of the ribosomal RNA showed that they belong to four species: Pythium aphanidermatum (77 isolates), P. spinosum (1 isolate), P. myriotylum (1 isolate), and P. catenulatum (1 isolate). Investigating the aggressiveness of three Pythium spp. on cucumber showed that P. aphanidermatum, P. myriotylum, and P. spinosum are pathogenic. Phylogenetic analysis of P. aphanidermatum isolates showed that most of the isolates obtained from cocopeat clustered separately from isolates obtained from soil and roots. This may indicate a difference in the origin of the cocopeat isolates. Evaluating the resistance of 27 P. aphanidermatum isolates to hymexazol showed that most isolates were sensitive (0.9 to 31.2 mg liter−1) whereas one isolate was resistant (142.9 mg liter−1). This study is the first to report P. myriotylum and P. catenulatum in Oman. It is also the first to report the development of resistance to hymexazol among P. aphanidermatum populations from greenhouses. Growers should use integrated disease management strategies to avoid further development of resistance to hymexazol.