1,116 research outputs found
Managing the Risks of Shale Gas Development Using Innovative Legal and Regulatory Approaches
Booming production of oil and gas from shale, enabled by hydraulic fracturing technology, has led to tension between hoped-for economic benefits and feared environmental and other costs, with great associated controversy. Study of how policy can best react to these challenges and how it can balance risk and reward has focused on prescriptive regulatory responses and, to a somewhat lesser extent, voluntary industry best practices. While there is undoubtedly room for improved regulation, innovative tools are relatively understudied. The liability system predates environmental regulation yet still plays an important — and in some senses predominant — role. Changes to that system, including burden-shifting rules and increased bond requirements, might improve outcomes. Similarly, new regulation can and should incorporate modern understanding of the benefits of market-based approaches. Information disclosure requirements can benefit the liability system and have independent benefits of their own. Policymakers faced with a need for policy change in reaction to shale development should carefully consider alternatives to regulation and, when regulation is deemed necessary, consider which tool is best suited
Immunogenic Burkholderia pseudomallei Outer Membrane Proteins as Potential Candidate Vaccine Targets
Background: Burkholderia pseudomallei is the causative agent of melioidosis, a disease of significant morbidity and mortality in both human and animals in endemic areas. There is no vaccine towards the bacterium available in the market, and the efficacy of many of the bacterium’s surface and secreted proteins are currently being evaluated as vaccine candidates. Methodology/Principal Findings: With the availability of the B. pseudomallei whole genome sequence, we undertook to identify genes encoding the known immunogenic outer membrane protein A (OmpA). Twelve OmpA domains were identified and ORFs containing these domains were fully annotated. Of the 12 ORFs, two of these OmpAs, Omp3 and Omp7, were successfully cloned, expressed as soluble protein and purified. Both proteins were recognised by antibodies in melioidosis patients ’ sera by Western blot analysis. Purified soluble fractions of Omp3 and Omp7 were assessed for their ability to protect BALB/c mice against B. pseudomallei infection. Mice were immunised with either Omp3 or Omp7, subsequently challenged with 1610 6 colony forming units (cfu) of B. pseudomallei via the intraperitoneal route, and examined daily for 21 days post-challenge. This pilot study has demonstrated that whilst all control unimmunised mice died by day 9 post-challenge, two mice (out of 4) from both immunised groups survived beyond 21 days post-infection. Conclusions/Significance: We have demonstrated that B. pseudomallei OmpA proteins are immunogenic in mice as well a
Perbandingan filogenetik protein antigen-I yang berpotensi sebagai calon diagnostik dan vaksin terhadap parasit cryptocaryon irritans
Protein antigen-i parasit ikan C. irritans berpotensi tinggi digunakan sebagai calon dalam pembangunan vaksin komersial terhadap C. irritans. Walau bagaimanapun, kewujudan variasi pada antigen-i serotip C. irritans yang berbeza mempengaruhi tahap perlindungan yang bakal diberikan terhadap varians C. irritans yang berbeza apabila antigen-i digunakan sebagai vaksin. Kajian ini dijalankan untuk membandingkan jujukan pelbagai antigen-i pencilan C. irritans di Malaysia berbanding antigen-i pencilan C. irritans yang pernah dilaporkan. Perbandingan filogenetik dijalankan untuk meramalkan potensi protein tersebut dalam usaha membangunkan calon serodiagnostik dan pemvaksinan terhadap pencilan C. irritans yang berlainan. Penjajaran jujukan berbilang bagi jujukan asid amino antigen-i dilakukan dengan perisian CLUSTALX dan analisis filogenetik antigen-i dilakukan menggunakan kaedah parsimoni maksimum (MP) dan kaedah Bayes. Sembilan transkrip unik (TU) C. irritans yang mempunyai padanan signifikan dengan antigen-i di pangkalan data protein NCBI didapati mempunyai peratus kesamaan antara 41% hingga 71%. Kedua-dua pohon MP dan Bayesian yang dijana menunjukkan varians antigen-i cn56 and cn57 terkelompok bersama dalam satu kumpulan manakala varians antigen-i yang lain terbahagi kepada dua kumpulan berasingan dan pengkelompokan ini disokong oleh kehadiran asid amino yang terpulihara dalam kumpulan masing-masing. Kajian lanjutan boleh dilakukan untuk mengenal pasti varians antigen-i yang sesuai sebagai calon serodiagnosis dan juga dapat memberi perlindungan silang terhadap pelbagai pencilan C. irritans di serata dunia
Cloning and Expression of a Burkholderia pseudomallei Putative Peptidase M23B
Abstract Burkholderia pseudomallei is a Gram negative bacillus that causes melioidosis, an infectious disease endemic to Southeast Asia and Northern Australia. Identification and verification of the various virulence factors implicated in pathogenicity is vital in developing recombinant proteins as effective vaccine candidates. Previously, the peptidase M23B gene sequence was successfully identified through screening of a B. pseudomallei small insert library with a melioidosis patient serum. Here we report the cloning and expression of the peptidase M23B gene in an Escherichia coli expression system. The peptidase M23B gene sequence was amplified, cloned into the pET 200/D-TOPO vector and transformed into E. coli One Shot TOP10 cells. Recombinant clones were confirmed by restriction analysis with NheI and SacI and insert DNA sequencing. The digestion profile indicated that the gene was inserted in the correct orientation within the vector. Sequence analysis demonstrated a high similarity to the B. pseudomallei K96243 peptidase M23B gene as well as the B. mallei ATCC 23344 NlpD lipoprotein gene. Expression of a selected clone in E. coli BL21 Star™ (DE3) was carried out. The expressed recombinant protein was analyzed through SDS-PAGE and western blotting. A protein band of 36 kDa was visible within the inclusion body fraction. Protein refolding and proteolytic activity analysis on the inclusion body fraction was performed. No proteolytic activity was observed for the recombinant protein, suggesting that the protein was probably not a peptidase enzyme but more likely a lipoprotein. Nevertheless, the cloning and expression of this gene which encodes an immunogenic protein, was successful and the recombinant protein obtained can be further characterized to determine its identity and effectiveness as a melioidosis vaccine candidate
Genome wide transcriptome profiling of a murine acute melioidosis model reveals new insights into how Burkholderia pseudomallei overcomes host innate immunity
Abstract Background At present, very little is known about how Burkholderia pseudomallei (B. pseudomallei) interacts with its host to elicit melioidosis symptoms. We established a murine acute-phase melioidosis model and used DNA microarray technology to investigate the global host/pathogen interaction. We compared the transcriptome of infected liver and spleen with uninfected tissues over an infection period of 42 hr to identify genes whose expression is altered in response to an acute infection. Results Viable B. pseudomallei cells were consistently detected in the blood, liver and spleen during the 42 hr course of infection. Microarray analysis of the liver and spleen over this time course demonstrated that genes involved in immune response, stress response, cell cycle regulation, proteasomal degradation, cellular metabolism and signal transduction pathways were differentially regulated. Up regulation of toll-like receptor 2 (TLR2) gene expression suggested that a TLR2-mediated signalling pathway is responsible for recognition and initiation of an inflammatory response to the acute B. pseudomallei infection. Most of the highly elevated inflammatory genes are a cohort of "core host immune response" genes commonly seen in general inflammation infections. Concomitant to this initial inflammatory response, we observed an increase in transcripts associated with cell-death, caspase activation and peptidoglysis that ultimately promote tissue injury in the host. The complement system responsible for restoring host cellular homeostasis and eliminating intracellular bacteria was activated only after 24 hr post-infection. However, at this time point, diverse host nutrient metabolic and cellular pathways including glycolysis, fatty acid metabolism and tricarboxylic acid (TCA) cycle were repressed. Conclusions This detailed picture of the host transcriptional response during acute melioidosis highlights a broad range of innate immune mechanisms that are activated in the host within 24 hrs, including the core immune response commonly seen in general inflammatory infections. Nevertheless, this activation is suppressed at 42 hr post-infection and in addition, suboptimal activation and function of the downstream complement system promotes uncontrolled spread of the bacteria.</p
Sequence analysis of the fusion (f) protein cleavage site of four Newcastle disease virus isolates
The amino acid sequence of the fusion (F) protein of Newcastle disease virus (NDV) is of particular interest as its virulence is highly dependent on susceptibility to proteolytic cleavage. The F protein precursor, F0' can beproteolytically cleaved to form disulfide-linked F, and F2 chains. The Fa cleavage is a prerequisite for producing infectious particles
whereby the nature of the cleavage site correlates with virulence of the virus. Inthis study we determined the F protein gene cleavage site nucleotide sequence ofNDV local isolates 2641191 P2, 5953/89 P3, 1266/89 P3 and 8820/92 P3. Their sequences were also compared with other NDV strains and isolates, such as AF2240, OOIIKS, 011TM, 01lC, 3410/92 P2, 6385/90 P3, V4 Que and F that had previously been determined. The deduced amino acid sequence of this site revealed the pathogenecity of these strains whereby 2641191 P2 and 5953/89 P3 were classified as virulent isolates whilst 1266/89 P3 and 8820/92 P3 were avirulent isolates
Beyond Traditional Antimicrobials: A Caenorhabditis elegans Model for Discovery of Novel Anti-infectives
The spread of antibiotic resistance amongst bacterial pathogens has led to an urgent need for new antimicrobial compounds with novel modes of action that minimize the potential for drug resistance. To date, the development of new antimicrobial drugs is still lagging far behind the rising demand, partly owing to the absence of an effective screening platform. Over the last decade, the nematode Caenorhabditis elegans has been incorporated as a whole animal screening platform for antimicrobials. This development is taking advantage of the vast knowledge on worm physiology and how it interacts with bacterial and fungal pathogens. In addition to allowing for in vivo selection of compounds with promising anti-microbial properties, the whole animal C. elegans screening system has also permitted the discovery of novel compounds targeting infection processes that only manifest during the course of pathogen infection of the host. Another advantage of using C. elegans in the search for new antimicrobials is that the worm itself is a source of potential antimicrobial effectors which constitute part of its immune defense response to thwart infections. This has led to the evaluation of effector molecules, particularly antimicrobial peptides (AMPs), as candidates for further development as therapeutic agents. In this review, we provide an overview on the use of the C. elegans model for identification of novel anti-infectives. We highlight some highly potential lead compounds obtained from C. elegans-based screens, particularly those that target bacterial virulence or host defense to eradicate infections, a mechanism distinct from the action of conventional antibiotics. We also review the prospect of using C. elegans AMPs as an antimicrobial strategy to treat infections
Questionable Research Practices Among Researchers in the Most Research-Productive Management Programs
Questionable research practices (QRPs) among researchers have been a source of concern in many fields of study. QRPs are often used to enhance the probability of achieving statistical significance which affects the likelihood of a paper being published. Using a sample of researchers from ten top research-productive management programs, we compared hypotheses tested in dissertations to those tested in journal articles derived from those dissertations to draw inferences concerning the extent of engagement in QRPs. Results indicated that QRPs related to changes in sample size and covariates were associated with unsupported dissertation hypotheses becoming supported in journal articles. Researchers also tended to exclude unsupported dissertation hypotheses from journal articles. Likewise, results suggested that many article hypotheses may have been created after the results were known (i.e., HARKed). Articles from prestigious journals contained a higher percentage of potentially HARKed hypotheses than those from less well-regarded journals. Finally, articles published in prestigious journals were associated with more QRP usage than less prestigious journals. QRPs increase in the percentage of supported hypotheses and effect sizes that likely result in overestimated population parameters. As such, results reported in articles published in our most prestigious journals may be less credible than previously believed
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