A new emerging disease in shrimp, first reported in 2009, was initially named early mortality syndrome (EMS). In 2011, a more descriptive name for the acute phase of the disease was proposed as acute hepatopancreatic necrosis syndrome (AHPNS). Affecting both Pacific white shrimp Penaeus vannamei and black tiger shrimp P. monodon, the disease has caused significant losses in Southeast Asian shrimp farms. AHPNS was first classified as idiopathic because no specific causative agent had been identified. However, in early 2013, the Aquaculture Pathology Laboratory at the University of Arizona was able to isolate the causative agent of AHPNS in pure culture. Immersion challenge tests were employed for infectivity studies, which induced 100% mortality with typical AHPNS pathology to experimental shrimp exposed to the pathogenic agent. Subsequent histological analyses showed that AHPNS lesions were experimentally induced in the laboratory and were identical to those found in AHPNS-infected shrimp samples collected from the endemic areas. Bacterial isolation from the experimentally infected shrimp enabled recovery of the same bacterial colony type found in field samples. In 3 separate immersion tests, using the recovered isolate from the AHPNS-positive shrimp, the same AHPNS pathology was reproduced in experimental shrimp with consistent results. Hence, AHPNS has a bacterial etiology and Koch's Postulates have been satisfied in laboratory challenge studies with the isolate, which has been identified as a member of the Vibrio harveyi clade, most closely related to V. parahemolyticus.
The 69 kb plasmid pVPA3-1 was identified in Vibrio parahaemolyticus strain 13-028/A3 that can cause acute hepatopancreatic necrosis disease (AHPND). This disease is responsible for mass mortalities in farmed penaeid shrimp and is referred to as early mortality syndrome (EMS). The plasmid has a GC content of 45.9% with a copy number of 37 per bacterial cell as determined by comparative quantitative PCR analyses. It consists of 92 open reading frames that encode mobilization proteins, replication enzymes, transposases, virulence-associated proteins, and proteins similar to Photorhabdus insect-related (Pir) toxins. In V. parahaemolyticus, these Pir toxin-like proteins are encoded by 2 genes ( pirA-and pirB-like) located within a 3.5 kb fragment flanked with inverted repeats of a transposase-coding sequence (1 kb). The GC content of these 2 genes is only 38.2%, substantially lower than that of the rest of the plasmid, which suggests that these genes were recently acquired. Based on a proteomic analysis, the pirA-like (336 bp) and pirB-like (1317 bp) genes encode for 13 and 50 kDa proteins, respectively. In laboratory cultures of V. parahaemolyticus 13-028/A3, both proteins were secreted into the culture medium. We developed a duplex PCR diagnostic method, with a detection limit of 10 5 CFU ml −1 and targeting pirA-and pirB-like genes in this strain of V. parahaemolyticus. This PCR protocol can reliably detect AHPND-causing strains of V. parahaemolyticus and does not cross react with non-pathogenic strains or with other species of Vibrio isolated from shrimp ponds.
Fuzzy set theory has serious difficulties in producing valid answers in decision-making by fuzzifying judgments. No theorems are available about its workability when it is applied indiscriminately as a number crunching approach to numerical measurements that represent judgments. When judgments are allowed to vary in choice over the values of a fundamental scale, as in the Analytic Hierarchy Process, these judgments are themselves already fuzzy. To make them fuzzier can make the validity of the outcome, when the actual outcome is known, worse, as shown by several examples in this paper. Also, improving the consistency of a judgment matrix does not necessarily improve the validity of the outcome. Validity is the goal in decision-making, not consistency, which can be successively improved by manipulating the judgments as the answer gets farther and farther from reality. An example of this is included.
Summary Background Methadone is an effective treatment for opioid dependence. When people who are receiving methadone maintenance treatment for opioid dependence are incarcerated in prison or jail, most US correctional facilities discontinue their methadone treatment, either gradually, or more often, abruptly. This discontinuation can cause uncomfortable symptoms of withdrawal and renders prisoners susceptible to relapse and overdose on release. We aimed to study the effect of forced withdrawal from methadone upon incarceration on individuals’ risk behaviours and engagement with post-release treatment programmes. Methods In this randomised, open-label trial, we randomly assigned (1:1) inmates of the Rhode Island Department of Corrections (RI, USA) who were enrolled in a methadone maintenance-treatment programme in the community at the time of arrest and wanted to remain on methadone treatment during incarceration and on release, to either continuation of their methadone treatment or to usual care—forced tapered withdrawal from methadone. Participants could be included in the study only if their incarceration would be more than 1 week but less than 6 months. We did the random assignments with a computer-generated random permutation, and urn randomisation procedures to stratify participants by sex and race. Participants in the continued-methadone group were maintained on their methadone dose at the time of their incarceration (with dose adjustments as clinically indicated). Patients in the forced-withdrawal group followed the institution’s standard withdrawal protocol of receiving methadone for 1 week at the dose at the time of their incarceration, then a tapered withdrawal regimen (for those on a starting dose >100 mg, the dose was reduced by 5 mg per day to 100 mg, then reduced by 3 mg per day to 0 mg; for those on a starting dose ≤100 mg, the dose was reduced by 3 mg per day to 0 mg). The main outcomes were engagement with a methadone maintenance-treatment clinic after release from incarceration and time to engagement with methadone maintenance treatment, by intention-to-treat and as-treated analyses, which we established in a follow-up interview with the participants at 1 month after their release from incarceration. Our study paid for 10 weeks of methadone treatment after release if participants needed financial help. This trial is registered with ClinicalTrials.gov, number NCT01874964. Findings Between June 14, 2011, and April 3, 2013, we randomly assigned 283 prisoners to our study, 142 to continued methadone treatment, and 141 to forced withdrawal from methadone. Of these, 60 were excluded because they did not fit the eligibility criteria, leaving 114 in the continued-methadone group and 109 in the forced-withdrawal group (usual care). Participants assigned to continued methadone were more than twice as likely than forced-withdrawal participants to return to a community methadone clinic within 1 month of release (106 [96%] of 110 in the continued-methadone group compared with 68 [78%] of 87 in the for...
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