Characterization of the Bacteriophage vB_VorS-PVo5 Infection on Vibrio ordalii: A Model for Phage-Bacteria Adsorption in Aquatic Environments.

A mathematical first-order difference equation was designed to predict the dynamics of the phage-bacterium adsorption process in aquatic environments, under laboratory conditions. Our model requires knowledge of bacteria and bacteriophage concentrations and the measurements of bacterial size and velocity to predict both the number of bacteriophages adsorbed onto their bacterial host and the number of infected bacteria in a given specific time. It does not require data from previously performed adhesion experiments. The predictions generated by our model were validated in laboratory. Our model was initially conceived as an estimator for the effectiveness of the inoculation of phages as antibacterial therapy for aquaculture, is also suitable for a wide range of potential applications.

Surgical Results in Ocriplasmin Candidates With Symptomatic Vitreomacular Traction Syndrome.

PURPOSE: To report surgical outcomes in a series of cases with symptomatic vitreomacular traction that met MIVI-TRUST (Microplasmin for intravitreous injection-traction release without surgical treatment) criteria for ocriplasmin use who underwent primary 25-gauge vitrectomy. MATERIALS AND METHODS: A single-center retrospective chart review study was performed in patients who underwent primary 25-gauge vitrectomy for symptomatic vitreomacular traction (VTM) from January 2013 through January 2016. Pre- and postoperative visual acuity (measured by the early treatment diabetic retinopathy acuity test), and posterior hyaloid focal attachment to the macula (demonstrated by high-definition optical coherence tomography) were analyzed. In addition, intra- and postoperative complications were obtained from medical records. RESULTS: Fifteen consecutive cases of symptomatic VMT traction that underwent primary 25-gauge vitrectomy were included. All met the MIVI-TRUST criteria for ocriplasmin use. In all cases, VMT resolution, macular hole closure, and improvement in best corrected visual acuity (BCVA) were observed. Mean visual acuity improved from 56.53 ± 16.04 letters at baseline to 73.13 ± 7.46 letters at 24 weeks of follow-up. The mean BCVA improvement from baseline was 16.60 letters (range 6-44), which was statistically significant (P < 0.0001). Ten of fifteen patients (66.6%) showed significant improvement of their BCVA to 20/40 or better (70 or more in ETDRS visual acuity test). No significant intra- or postoperative complications were documented. CONCLUSIONS: Primary 25-gauge pars plana vitrectomy in eyes with symptomatic vitreomacular traction is able to efficiently resolve VMT and macular holes, improving vision in candidates for intravitreal injection of ocriplasmin. This well-tolerated surgical procedure may be a reliable and predictable alternative for resolving VMT pathology.

A pulse fishery model with closures as function of the catch: conditions for sustainability.

We present a model of single species fishery which alternates closed seasons with pulse captures. The novelty is that the length of a closed season is determined by the remaining stock size after the last capture. The process is described by a new type of impulsive differential equations recently introduced. The main result is a fishing effort threshold which determines either the sustainability of the fishery or the extinction of the resource.