Diversity in secondary metabolites including mycotoxins from strains of aspergillus section nigri isolated from raw cashew nuts from Benin, West Africa

Open access JournalIn a previous study, raw cashew kernels were assayed for the fungal contamination focusing on strains belonging to the genus Aspergillus and on aflatoxins producers. These samples showed high contamination with Aspergillus section Nigri species and absence of aflatoxins. To investigate the diversity of secondary metabolites, including mycotoxins, the species of A. section Nigri may produce and thus threaten to contaminate the raw cashew kernels, 150 strains were isolated from cashew samples and assayed for their production of secondary metabolites using liquid chromatography high resolution mass spectrometry (LC-HRMS). Seven species of black Aspergilli were isolated based on morphological and chemical identification: A. tubingensis (44%), A. niger (32%), A. brasiliensis (10%), A. carbonarius (8.7%), A. luchuensis (2.7%), A. aculeatus (2%) and A. aculeatinus (0.7%). From these, 45 metabolites and their isomers were identified. Aurasperone and pyranonigrin A, produced by all species excluding A. aculeatus and A. aculeatinus, were most prevalent and were encountered in 146 (97.3%) and 145 (95.7%) isolates, respectively. Three mycotoxins groups were detected: fumonisins (B2 and B4) (2.7%) ochratoxin A (13.3%), and secalonic acids (2%), indicating that these mycotoxins could occur in raw cashew nuts. Thirty strains of black Aspergilli were randomly sampled for verification of species identity based on sequences of β-tubulin and calmodulin genes. Among them, 27 isolates were positive to the primers used and 11 were identified as A. niger, 7 as A. tubingensis, 6 as A. carbonarius, 2 as A. luchuensis and 1 as A. welwitschiae confirming the species names as based on morphology and chemical features. These strains clustered in 5 clades in A. section Nigri. Chemical profile clustering also showed also 5 groups confirming the species specific metabolites production

Sustainable subdivision design and energy consumption of households in the hot and humid tropical climate of Darwin

This paper examines the relationship between sustainable subdivision design principles, local microclimate, and household energy consumption. The energy-efficient subdivision design principles, energy consumption and adjustment behaviour of 36 households were investigated in two suburbs of the city of Darwin. The participating households completed a questionnaire on family structure, thermal preferences and behaviour adjustment to the indoor environment. Electricity consumption of households was recorded at 30-minute intervals from Nov 2015 to Aug 2016. The Muirhead suburb, designed with energy-efficiency and climate-responsive design principles, has 16.9 lots per hectare in dense areas and minimum lot area of 450m2. Another suburb, Lyons, has 14.4 lots per hectare and a minimum lot area of 525m2. Households were divided by lot areas into three categories: category 1 (450-610m2), category 2 (611-710m2), and category 3 (>710m2). In Muirhead, the average daily consumption of category one household in the warmer wet season was 98 Wh/m2 per person compared to 154 Wh/m2 per person in Lyons. In the cooler dry season 48 Wh/m2 per person in Muirhead and 87 Wh/m2 in Lyons. The cooling load was calculated using multiple regression analysis showed that the main difference in energy consumption between two suburbs was in the base load. Thus, the energy-efficiency and climate-responsive design principles, applied to the subdivision, mitigate the impact of urban heat on cooling energy consumption in the hot and humid climate of Darwin. These are preliminary results and further investigation of the factors that have an impact on energy consumption of participating households is continuing

Diversity in secondary metabolites including mycotoxins from strains of aspergillus section nigri isolated from raw cashew nuts from benin, west africa

PubMed ID: 27768708In a previous study, raw cashew kernels were assayed for the fungal contamination focusin on strains belonging to the genus Aspergillus and on aflatoxins producers. These sample showed high contamination with Aspergillus section Nigri species and absence o aflatoxins. To investigate the diversity of secondary metabolites, including mycotoxins, th species of A. section Nigri may produce and thus threaten to contaminate the raw cashe kernels, 150 strains were isolated from cashew samples and assayed for their productio of secondary metabolites using liquid chromatography high resolution mass spectrometr (LC-HRMS). Seven species of black Aspergilli were isolated based on morphological an chemical identification: A.Tubingensis (44%), A. niger (32%), A. brasiliensis (10%), A. carbonariu (8.7%), A. luchuensis (2.7%), A. aculeatus (2%) and A. aculeatinus (0.7%). Fro these, 45 metabolites and their isomers were identified. Aurasperone and pyranonigrin A produced by all species excluding A. aculeatus and A. aculeatinus, were most prevalen and were encountered in 146 (97.3%) and 145 (95.7%) isolates, respectively. Three mycotoxin groups were detected: fumonisins (B2 and B4) (2.7%) ochratoxin A (13.3%), an secalonic acids (2%), indicating that these mycotoxins could occur in raw cashew nuts Thirty strains of black Aspergilli were randomly sampled for verification of species identit based on sequences of ß-Tubulin and calmodulin genes. Among them, 27 isolates wer positive to the primers used and 11 were identified as A. niger, 7 as A.Tubingensis, 6 as A carbonarius, 2 as A. luchuensis and 1 as A. welwitschiae confirming the species names a based on morphology and chemical features. These strains clustered in 5 clades in A. sectio Nigri. Chemical profile clustering also showed also 5 groups confirming the speciespecific metabolites production. © 2016 Lamboni et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Telework: Timesaving or Timeconsuming? An Investigation into Actual Working Hours

Contains fulltext : 68708.pdf (publisher's version ) (Closed access)This paper aims to clarify the relationship between telework and the actual time employees put into their jobs. One of the reported threats to teleworkers' personal lives is that in order to finish their work, they not only use up saved commuting time, but also part of their non-working hours, even to the extent of becoming workaholics. Recent empirical analyses show that teleworkers do seem to work longer hours than non-teleworkers. Yet there is an interesting observation to be made: teleworkers are not found to work longer hours when compared with employees who are given the teleworking option but not taking it. One might hypothesise, therefore, that there might be other factors accounting for the longer working hours of teleworkers (and of "teleworkable" job-holders), rather than teleworking as such. For that reason, the effect of teleworking on working hours was controlled for job and pay system characteristics. In line with expectations, salaried work, higher wages, and some fringe benefits accounted for longer hours, and telework did not. Therefore, telework may be rightly used as an HRM-tool to attract and/or retain (scarce) personnel, for it allows employees to save commuting time and, consequently, contributes to a better work-home balance.22 p