Strengthening the resilience of small-scale fisheries: A modeling approach to explore the use of in-shore pelagic resources in Melanesia

Small-scale fisheries play a critical role in both poverty alleviation and food security. A large proportion of the world fish stocks are, however, getting fully or over-exploited. In this article we address these issues in the context of the small-scale fisheries of the Solomon Islands. The paper explores the extent to which in-shore Fish Aggregating Devices (FADs) can help increasing the resilience of the small scale fishery system and reconciling social, economic and ecological priorities. Based on the concept of ‘time of crisis’ developed recently in the viability literature, we propose to calculate a resilience index through a dynamic stochastic model calibrated by ethnological observations. The resilience index calculation reveals two major findings: (i) the resilience of the small scale fishery system is currently nonexistent and (ii) the introduction of FADs can improve it. The effects of the FADs' implementation are then discussed in the light of a socio-economic perspective. Such results bring new insights into the question of the future of the small scale fishery sector, especially in relation to the local economy evolution from a barter dominance to a cash oriented economy. At the same time, the current subsistence fisheries seems more resilient in general due to a distributive effects which ease the ‘race for fish behaviors’. Finally, our analysis reveals that while the FADs implementation stands as a short and mid-term answer, demographic drivers are important and other alternatives will need to be considered if the overall viability of the system is to be maintained in the longer-term.     

Comparing the efficiency of chitosan with chlorine for reducing Vibrio parahaemolyticus in shrimp

Thailand is one of the leading exporters of frozen shrimp to many countries. Chlorine is the decontaminating agent most frequently used in the frozen shrimp industries to kill potential pathogens. However, long time contact to chlorine causes severe respiratory tract damage. In this study, chitosan was compared to chlorine for reducing Vibrio parahaemolyticus. In vitro investigation, chitosan could reduce more than 90% of V. parahaemolyticus, whereas chlorine completely eliminated this organism. In artificially inoculated shrimp, more than 90% reduction of V. parahaemolyticus was achieved by chitosan. A similar reduction was obtained by chlorine, however, at lower concentrations and less contact time. In naturally contaminated shrimp, neither agent completely eradicated V. parahaemolyticus, however, chitosan achieved a decrease of more than 60%. These results demonstrate the possibility of using chitosan to decontaminate pathogenic bacteria in the seafood factory, a change that would diminish health problems of the workers.     

Genetic diversity of ivory shell (Babylonia areolata) in Taiwan and identification of species using DNA-based assays

For better traceability of seafood products in Taiwan, we need to effectively test product quality during the processes of identification of seafood species. The aim of this study was to analyse gene diversity and the methods of identification of high-value seafood, ivory shell (Babylonia areolata), on the Penghu Island in Taiwan using molecular marker technology and to build a relevant molecular database. Thirty-three samples of B. areolata and the samples of 5 other Babylonia species, including Babylonia feicheni, Babylonia spirata spirata, Babylonia perforata and Babylonia formosae formosae, from cultivation and from the wild were tested using the inter-simple sequence repeat (ISSR) method, mitochondrial DNA analysis, PCR-single-strand conformation polymorphism (PCR-SSCP) and PCR-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that the primers ISSR3, ISSR7 and ISSR13 of the ISSR method and cytochrome C oxidase subunit 1 (coxI) gene analysis have a good discriminatory power in inter-species and intra-species tests. In conclusion, ISSR, PCR-DGGE and PCR-SSCP with coxI analysis can be used for the screening and identification of B. areolata species. Furthermore, these molecular methods could be useful for the identification of other types of seafood.     

Carotenoids in crabs from marine and fresh waters of India

Quantitative and qualitative distribution of carotenoids in meat and shell of major marine crab (Charybdis cruciata) and fresh water crab (Potamon potamon) from Indian waters was assessed. The total carotenoid content was low in both species of crabs analysed, highest being 11.0 μg/g in shell of marine crab. Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) of carotenoid extracts indicated that the marine crab contained astaxanthin and its esters as major carotenoids and zeaxanthin was major carotenoid in fresh water crab extract. Astaxanthin and its esters contributed 67.6 and 65.5 g/100 g of total carotenoids in meat and shell of marine crab. The zeaxanthin content (g/100 g) in the carotenoid extract of meat and shell of fresh water crab was 42.0 and 74.8 of total carotenoids. The carotenoid extracts from both the crabs had higher level of unsaturated fatty acids. Oleic acid (C18:1) and palmitoleic acid (C16:1) were the predominant unsaturated fatty acid in carotenoid extract from meat of marine and fresh water crab, respectively. In the carotenoid extract from shell, eicosenoic acid (C20:1) in marine crab and linolenic acid (C18:3) in fresh water crab were the major unsaturated fatty acids.     

Engineered clostridial [FeFe]-hydrogenase shows improved O2 tolerance in Chlamydomonas reinhardtii

Hydrogenase intolerance to oxygen remains a critical hurdle on the road to photosynthetic hydrogen production for sustainable energy demands. Although the engineering of the intrinsic oxygen tolerance mechanism of hydrogenase using mutagenesis is an ambitious approach, recent in-vitro studies reported a novel and improved synthetic [FeFe]-Hydrogenase variants. To corroborate these findings in-vivo, we expressed either an engineered variant or its cognate wild type enzyme in the chloroplast genome of Chlamydomonas reinhardtii. We characterized their activity using a customized photosynthetic hydrogen production in-vivo assay to test whether the improved variant could maintain a greater fraction of its activity following oxygen exposure. We found that the mutated variant exhibited a superior oxygen tolerance while persevering its photosynthetic performance in terms of hydrogen production yield. Importantly, we show for the first time that this approach can potentially address the inherent O₂ sensitivity of [FeFe]-Hydrogenases for photosynthetic hydrogen production.     

Nutritional properties and phenolic content of a bakery product substituted with a mango (Mangifera indica) ‘Ataulfo’ processing by-product

Wheat flour and cane sugar were partially substituted (50 and 75%) by a mango-processing by-product (MPB) as an added-value food ingredient in muffins. Their sensory analysis, chemical composition, antioxidant activity and in vitro starch hydrolysis properties were studied. Sensory analysis showed statistically significant difference (p < 0.05) between control and muffins 75% MPB substituted level (p < 0.05) with the highest score. Proximate analysis revealed that muffins substituted with MPB had significantly (p < 0.05) higher moisture, ash, soluble, insoluble and total indigestible fraction contents but lower total soluble carbohydrates and available starch contents than a non-substituted (control) muffin. Total soluble polyphenol (TSP) content increased about three times (from 1.86 to 5.36 g GAE/100 g dw) with MPB substitution. Chlorogenic, caffeic, gallic, hydroxycinnamic and ferulic acids were identified as major TSP. Muffins with MPB, exhibited better antioxidant properties (104.0 to 108.5 μmol TE/g dw for DPPH assay and 34.1 to 19.1 mmol TE/g dw for FRAP assay) than the control formulation. The presence of high phenolic and insoluble indigestible fraction contents, which may be responsible of the lower rate of starch hydrolysis observed in muffins prepared with MPB, might modulate the postprandial glucose response in vivo. MPB may be used as an ingredient in foods with add-value with potential health-promoting features, besides providing a solution to the environmental problems associated with the disposal of mango by-products.     

Determination of the potential of cyanobacterial strains for hydrogen production

Hydrogen (H₂) is a renewable, abundant, and nonpolluting source of energy. Photosynthetic organisms capture sunlight very efficiently and convert it into organic molecules. Cyanobacteria produce H₂ by breaking down organic compounds and water. In this study, biological H₂ was produced from various strains of cyanobacteria. Moreover, H₂ accumulation by Synechocystis sp. PCC 6803 was as high as 0.037 μmol/mg Chl/h within 120 h in the dark. The wild-type, filamentous, non-heterocystous cyanobacterium Desertifilum sp. IPPAS B-1220 was found to produce a maximum of 0.229 μmol/mg Chl/h in the gas phase within 166 h in the light, which was on par with the maximum yield reported in the literature. DCMU at 10 μM increased H₂ production by Desertifilum sp. IPPAS B-1220 by 1.5-fold to 0.348 μmol H₂/mg Chl/h. This is the first report on the capability of Desertifilum cyanobacterium to produce H₂.     

Study of interactions in carbon nanotubes systems by using Raman and SERS spectroscopy

We present results obtained on carbon nanotube systems by means of Raman scattering and surface enhanced Raman scattering (SERS). Such systems consist of single-walled nanotubes (SWNTs), multi-walled nanotubes (MWNTs), or polymer/nanotubes composites. In particular, we have focused our studies on the interactions taking place in these compounds which lead to an upshift of the radial breathing mode (RBM) in the case of SWNTs, either when they are arranged in bundles or embedded in polymers. Similar calculations has allowed us to interpret the low frequency Raman modes observed in purified MWNTs. We show that they come from the RBM of individual tubes. From intensity calculations performed to simulate Raman spectra, we demonstrate the importance of two experimental parameters, namely the diameter of internal tubes and the number of shells which constitute the MWNTs, such parameters being extracted experimentally from high resolution transmission electron microscopy images.     

Perception gaps between IS academics and IS practitioners: an exploratory study

It has long been recognized that there are significant perception gaps between information systems (IS) academics and IS practitioners with regards to the required IS knowledge/skills to perform their professional jobs successfully. Unfortunately, there is no consensus about which knowledge/skills are more important in the IS profession. With the rapidly changing IS technology and IS industry, a study was urgently needed to find and understand the gaps between these two groups. We report here on a study to measure the gap.