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Threats to water supply systems have increased in number and intensity. Natural disasters such as earthquakes have caused different types of damage to water distribution networks (WDN), particularly for those with aged infrastructure. This paper investigates the resilience of an existing water distribution network under seismic hazard. An earthquake generation model coupled with a probabilistic flow-based pressure driven demand hydraulic model is investigated and applied to an existing WDN. A total of 27 earthquake scenarios and 2 repair strategies were simulated. The analysis examined hydraulic resilience metrics such as pressure, leak demand, water serviceability, and population impacted. The results show that nodal pressure drops below nominal pressure and reaches zero in some earthquake scenarios. Leak demand could reach to more than 10 m 3 /s within hours following an earthquake. Water serviceability drops to a low of 40% and population impacted reaches up to 90% for a 6.5 M earthquake, for example. This study highlights and quantifies vulnerabilities within the simulated WDN. The tools outlined here illustrate an approach that can: (1) ultimately help to better inform utility water safety plans, and (2) prepare proactive strategies to mitigate/repair before a hazard of this nature occurs., (© 2022. The Author(s).)

Governments have implemented different interventions and response models to combat the spread of COVID-19. The necessary intensity and frequency of control measures require us to project the number of infected cases. Three short-term forecasting models were proposed to predict the total number of infected cases in Canada for a number of days ahead. The proposed models were evaluated on how their performance degrades with increased forecast horizon, and improves with increased historical data by which to estimate them. For the data analyzed, our results show that 7 to 10 weeks of historical data points are enough to produce good fits for a two-weeks predictive model of infected case numbers with a NRMSE of 1% to 2%. The preferred model is an important quick-deployment tool to support data-informed short-term pandemic related decision-making at all levels of governance., Competing Interests: The authors have declared that no competing interests exist.

Extending from the model proposed by Vasel-Be-Hagh et al. [J. Fluid Mech. 769, 522 (2015)], a perturbation analysis is performed to modify Turner's radius by taking into account the viscous effect. The modified radius includes two terms; the zeroth-order solution representing the effect of buoyancy, and the first-order perturbation correction describing the influence of viscosity. The zeroth-order solution is explicit Turner's radius; the first-order perturbation modification, however, includes the drag coefficient, which is unknown and of interest. Fitting the photographically measured radius into the modified equation yields the time history of the drag coefficient of the corresponding buoyant vortex ring. To give further clarification, the proposed model is applied to calculate the drag coefficient of a buoyant vortex ring at a Bond number of approximately 85; a similar procedure can be applied at other Bond numbers.

Background and Purpose: Staphylococcus saprophyticus is a frequent cause of both uncomplicated and complicated urinary tract infections (UTI) in young females and has recently been established as the most prominent gram-positive uropathogen. Although the effects of subinhibitory concentrations of antimicrobials on numerous other pathogenic bacteria have been studied, little is known regarding how S saprophyticus responds under such conditions., Materials and Methods: In this study, we investigated the effects of subminimum inhibitory concentrations (MIC) of ciprofloxacin (CIP) on S saprophyticus attachment to glass microscope slides, ureteral stent material, and T24 bladder cells, as well as its effects on S saprophyticus-induced proinflammatory cytokine expression in bladder cells., Results: Adherence to glass microscope slides, ureteral stent material, and bladder cell monolayers were all significantly increased in the presence of sub-MIC levels of CIP. While the S saprophyticus challenge of T24 bladder cell monolayers significantly upregulated both interleukin (IL)-6 and IL-8 expression, sub-MIC CIP abrogated these effects, returning their secretion to control levels., Conclusions: Our results demonstrate that exposure to sub-MIC CIP increases S saprophyticus adherence to both abiotic and biotic surfaces including urinary device material and cultured bladder cells. In addition, low levels of this antimicrobial downregulate S saprophyticus-stimulated proinflammatory cytokine secretion in the bladder. These changes may make S saprophyticus more effective at colonizing the urinary tract and highlights the need for clinicians to consider the impact of subinhibitory concentrations of antimicrobials on bacteria when designing treatment strategies to manage UTI.

Background: Thymosin beta 4 (Tβ(4)) is a major actin sequestering peptide present in most mammalian cells. It also acts as an anti-inflammatory agent and promotes corneal wound healing., Methods: In the present study, we constructed a four channel cylindrical flow chambers out of polydimethylsiloxane (PDMS) on microscope coverslips. The platelet-binding proteins-fibrinogen and collagen-were immobilized onto the middle ~25% of the inner cylindrical surface. The flow method introduced here was employed to determine the effect of Tβ(4), on the deposition of ADP-activated platelets onto fibrinogen cross-linked flow chambers., Results: The binding data from the flow chambers indicated that the both the rate constant of platelet deposition (average: 0.026±0.0015s(-1), corresponding to a half-life of 26.7s) and the total number of deposited platelets were independent of the platelet binding protein and the activating agent. Our results show that low concentrations of Tβ(4) (0.2 μM to 0.5 μM) increased both the rate constant of platelet deposition by ~1.5-fold (i.e. half-life decreased from 26.7s to 17.6s) and the total number of deposited platelets by ~3-fold. However at higher concentrations (>1 μM) the Tβ(4)-potentiating effect was diminished to near control levels. Tβ(4) did interact with fibrinogen with an estimated K(D) of ~126±18nM or 66±20nM under equilibrium or flow, respectively., Conclusion: These results suggest that Tβ(4) could potentially increase the affinity of platelet receptors for their ligands thus promoting platelet deposition. Tβ(4) could also bind to fibrinogen and as its concentration increased would prevent platelet-fibrinogen interactions resulting in the attenuation of platelet deposition., General Significance: This work suggests that Tβ(4) might have a dual role in platelet function., (Copyright © 2010 Elsevier B.V. All rights reserved.)