Induced spawning, larval development and rearing of two indigenous Malaysian mahseer, Tor tambroides and T. douronensis

The Mahseers (Tor spp.) are highly valued freshwater fishes across the Himalayan and South-east Asian regions. Over exploitation of natural stocks because of high demand and the deteriorating environmental conditions have resulted in marked decline of mahseers in the wild. Malaysian mahseers, T. tambroides (Bleeker) and T. douronensis (Valenciennes), locally known as empurau, kelah or belian and semah, respectively, have significant cultural and economic importance but both species are now threatened in the wild because of environmental degradation and over fishing. A captive breeding programme was instigated to attempt to propagate these two species artificially for conservation and aquaculture purposes. Both pond-reared and tank-held T. tambroides and T. douronensis reached sexual maturity in captivity and were successfully induced to spawn using hormone treatments. Ovaprim (0.5 mL kg⁻¹) was the most successful hormone treatment for both species. Pre-treatment of fish with Ovaplant (28–68 μg kg⁻¹, 2–7 weeks before spawning induction) greatly improved the success rate of spawning induction. Repeat spawning (within 4 months of initial spawning) was induced in some captive fish. Use of formalin baths improved hatching by preventing fungal infections. Embryonic development and hatching are described. Juveniles were reared in static greenwater ponds. Tor tambroides reached 142–179 g (max 270 g) in 60 weeks. These results represent the first successful captive spawning and rearing of both species. Options for future research to improve production are discussed.

Mitochondrial DNA diversity of broodstock of two indigenous mahseer species, Tor tambroides and T. douronensis (Cyprinidae) cultured in Sarawak, Malaysia

Tor tambroides and T. douronensis, locally referred to as empurau and semah, respectively, are high valued mahseer species, indigenous to Sarawak, East Malaysia, with an aquaculture potential and of conservational value. Direct sequencing of mitochondrial DNA (mtDNA) 16S rRNA gene region (542 bp) was used to investigate genetic variation of T. tambroides and T. douronensis broodstock collected from different geographic locations in Sarawak and maintained at the Indigenous Fish Research and Production Center (IFRPC), Tarat, Sarawak, Malaysia. A total of 11 unique haplotypes were identified, of which six were detected in T. tambroides, and five in T. douronensis. Overall, nucleotide diversity (π) was low, ranging from 0.000 to 0.006, and haplotype diversity (h) ranged from 0.000 to 0.599. Although the analysis failed to detect genetic variation amongst populations of T. tambroides (significant pairwise FST was found for only one test, but pairwise haplotype frequencies were not statistically significant), substantial inter-population divergence among T. douronensis was recognised, especially those originating from different river systems (pairwise F_ST = 0.754 to 1.000, P < 0.05). Fixed haplotype differences were found in one population of T. douronensis. Average nucleotide divergence between T. tambroides and T. douronensis was 0.018, similar to the amount recognised between T. tambroides and the outgroup T. khudree (0.017). In addition, phylogenetic analysis revealed that the T. douronensis mtDNA consisted of two highly divergent clusters (0.020), one of which is more closely related to T. tambroides rather than with the other group of haplotypes of the conspecifics. The findings from the present study have important implications for aquaculture, management and conservation of these two species. The data also raise some concerns regarding the taxonomic status of T. douronensis, which needs to be addressed.

Population structure in the highly fragmented range of Tor douronensis (Cyprinidae) in Sarawak, Malaysia revealed by microsatellite DNA markers

1. Understanding the structure of threatened populations, particularly those that exist in degraded or fragmented habitats is crucial for their effective management and conservation. Recently developed methods of individual-based analysis of genetic data provide an unprecedented opportunity to understand the relationships amongst fragmented populations.

2. In the present study, population structure of an important cyprinid species (Tor douronensis), which is indigenous to Sarawak, Malaysia, is investigated as part of an ongoing conservation effort to restore threatened wild populations of the species. The population structure inferred using data from seven autosomal microsatellite loci was generally consistent with geography and habitat fragmentation.

3. The results indicate that there are two well-defined clusters of T. douronensis in Sarawak, namely the 'northeastern' and the 'southwestern' clusters. In addition, a further subdivision was observed in each of the clusters distributed between river systems. Low levels of gene flow were also observed and migrants between habitat fragments were identified, possibly resulting from human-mediated translocations.

4. Implications of the findings for management and conservation of T. douronensis are discussed.

Characterization of microsatellite DNA markers for a mahseer species, Tor tambroides (Cyprinidae) and cross-amplification in four congeners

This study reports the isolation and characterization of microsatellite DNA markers in a mahseer species, Tor tambroides (Pisces, Cyprinidae). Of a total of 14 loci evaluated, 10 were polymorphic in T. tambroides samples, with an average of 2.86 alleles per locus. Deviations from Hardy–Weinberg equilibrium were observed at one locus and there was no indication of linkage disequilibrium among loci. A high level of cross-amplification among four congeners was achieved, with 12 loci successfully amplifying and 11 loci showing polymorphism in at least one other species. These markers will be a useful resource for population genetic studies and broodstock management of closely related mahseer species.

Contributions to propagation of two Tor species in Sarawak, Malaysia

The study focuses on the natural spawning ecology, induced spawning of captive broodstock and larval and fry nursing techniques of Tor tambroides and Tor douronensis, two mahseer fish of aquaculture and conservational importance. Both species were induced bred, and the development will help develop commercial aquaculture.

Postmodernist theory and its relationship to tourism research

This article highlights the theoretical notion of Postmodernism and attempts to place Tourism research into the postmodernism frame of reference. This is achieved by a brief description of the theory and further development in section two which reviews the challenges of postmodernism to research in the tourism field. There is then an endeavour to intertwine the constructs of postmodernist theory and to illustrate how it can relate to the tourism industry and in particular contemporary tourism. Indeed, we argue that even though a number of authors have begun to chart the sociological dimensions of post-modem tourism they have done so without highlighting the definitions and structure of postmodernist theory. Examples are given in order to support the theoretical approach to research which we suggest in this paper and every effort is undertaken in order to argue that postmodernist research in tourism can be beneficial and fruitful tor future directions. Consequently this article attempts to dispel some of the widespread bemusement concerning post-modem theories and post-modern tourism by reviewing some of the recent developments in the area and suggesting further research.

A critical analysis of techniques for risk mitigation in the construction industry

Risks exist in every form of construction project. The risks associated with construction projects are often diverse and varied and the management of these risks is nowadays considered compulsory in order to achieve project success. This paper analyses the diverse strategies of risk mitigation that have been employed in construction projects. These strategies are classified into analysed categories of procurement strategies. contingency and co-operative approach along with the utilisation of a designated risk manager. The analysis showed that in order to improve risk mitigation within the construction industry, there is a requirement tor an industry based standard. This standard will improve the efficiency and effectiveness of the risk mitigation response technique to risk management.

Internet content regulation, public drug websites and the growth in hidden Internet services

Governments have traditionally censored drug-related information, both in traditional media and, in recent years, in online media. We explore Internet content regulation from a drug-policy perspective by describing the likely impacts of censoring drug websites and the parallel growth in hidden Internet services. Australia proposes a compulsory Internet filtering regime that would block websites that ‘depict, express or otherwise deal with matters of… drug misuse or addiction’ and/or ‘promote, incite or instruct in matters of crime’. In this article, we present findings from a mixed-methods study of online drug discussion. Our research found that websites dealing with drugs, that would likely be blocked by the filter, in fact contributed positively to harm reduction. Such sites helped people access more comprehensive and relevant information than was available elsewhere. Blocking these websites would likely drive drug discussion underground at a time when corporate-controlled ‘walled gardens’ (e.g. Facebook) and proprietary operating systems on mobile devices may also limit open drug discussion. At the same time, hidden Internet services, such as Silk Road, have emerged that are not affected by Internet filtering. The inability for any government to regulate Tor websites and the crypto-currency Bitcoin poses a unique challenge to drug prohibition policies.
Read More: http://informahealthcare.com/doi/full/10.3109/09687637.2012.745828

The top 10 oomycete pathogens in molecular plant pathology

Oomycetes form a deep lineage of eukaryotic organisms that includes a large number of plant pathogens which threaten natural and managed ecosystems. We undertook a survey to query the community for their ranking of plant-pathogenic oomycete species based on scientific and economic importance. In total, we received 263 votes from 62 scientists in 15 countries for a total of 33 species. The Top 10 species and their ranking are: (1) Phytophthora infestans; (2, tied) Hyaloperonospora arabidopsidis; (2, tied) Phytophthora ramorum; (4) Phytophthora sojae; (5) Phytophthora capsici; (6) Plasmopara viticola; (7) Phytophthora cinnamomi; (8, tied) Phytophthora parasitica; (8, tied) Pythium ultimum; and (10) Albugo candida. This article provides an introduction to these 10 taxa and a snapshot of current research. We hope that the list will serve as a benchmark for future trends in oomycete research.

'What if you live on top of a bakery and you like cakes?'- Drug use and harm trajectories before, during and after the emergence of Silk Road

BACKGROUND: Cryptomarkets are digital platforms that use anonymising software (e.g. Tor) and cryptocurrencies (e.g. Bitcoin) to facilitate peer-to-peer (P2P) trade of goods and services. Their emergence has facilitated access to a wide range of high-quality psychoactive substances, according to surveys of users. In this paper, we ask the question 'How does changing access to drugs through cryptomarkets affect the drug use and harm trajectories of their users?'

METHODS: We conducted a digital ethnography spanning 2012-2014, a period that included the seizure of the original Silk Road marketplace and forum by law enforcement. Using encrypted online chat, we interviewed 17 people who reported using Silk Road to purchase illicit drugs. The interviews were in-depth and unstructured, and also involved the use of life history timelines to trace trajectories. Transcripts were analysed thematically using NVivo.

RESULTS: For some, Silk Road facilitated initiation into drug use or a return to drug use after cessation. Typically, participants reported experiencing a glut of drug consumption in their first months using Silk Road, described by one participant as akin to 'kids in a candy store'. There was evidence that very high availability reduced the need for drug hoarding which helped some respondents to moderate use and feel more in control of purchases made online. Cryptomarket access also appeared to affect solitary and social drug users differently. Most participants described using other cryptomarkets after the closure of Silk Road, albeit with less confidence.

CONCLUSION: In the context of high levels of drug access, supply and diversity occurring within a community regulated environment online, the impacts of cryptomarkets upon drug use trajectories are complex, often posing new challenges for self-control, yet not always leading to harmful outcomes. A major policy challenge is how to provide support for harm reduction in these highly volatile settings.