Repository logo

Escola Superior de Tecnologia e Gestão

Permanent URI for this community

http://hdl.handle.net/10400.8/5294

Browse

Browsing Escola Superior de Tecnologia e Gestão by Field of Science and Technology (FOS) "Ciências Agrárias::Agricultura, Silvicultura e Pescas"

Now showing 1 - 2 of 2
  • 2-Hydroxy-4-methoxybenzaldehyde fromHemidesmus indicusis antagonistic toStaphylococcus epidermidisbiofilm formation
    Publication . Kannappan, Arunachalam; Durgadevi, Ravindran; Srinivasan, Ramanathan; Lagoa, Ricardo José Lucas; Packiavathy, Issac Abraham Sybiya Vasantha; Pandian, Shunmugiah Karutha; Ravi, Arumugam Veera
    Staphylococcus epidermidis (SE) is an opportunistic nosocomial pathogen that accounts for recalcitrant device-related infections worldwide. Owing to the growing interest in plants and their secondary metabolites targeting bacterial adhesion, this study was intended to uncover the anti-biofilm potential of Hemidesmus indicus and its major constituent 2-hydroxy-4-methoxybenzaldehyde (HMB) against SE. The minimum biofilm inhibitory concentration (MBIC) of H. indicus root extract and HMB were found to be 500 and 250 µg ml−1, respectively. The results of time-dependent biofilm inhibition and mature biofilm disruption assays confirmed that HMB targets initial cell adhesion. Furthermore, interference by HMB in the expression of adhesin genes (icaA, aap and bhp) and biofilm components was associated with an increased susceptibility of SE to oxidative stress and antibiotics. To conclude, this study reports for the first time HMB as a potential drug against SE biofilms.
    2020-06-26Journal article Open access Show more
  • Effectiveness of Nature-Based Solutions in Mitigating Flood Hazard in a Mediterranean Peri-Urban Catchment
    Publication . Ferreira, Carla S.; Mourato, Sandra; Kasanin-Grubin, Milica; Ferreira, António J. D.; Destouni, Georgia; Kalantari, Zahra
    Urbanization alters natural hydrological processes and enhances runoff, which affects flood hazard. Interest in nature-based solutions (NBS) for sustainable mitigation and adaptation to urban floods is growing, but the magnitudes of NBS effects are still poorly investigated. This study explores the potential of NBS for flood hazard mitigation in a small peri-urban catchment in central Portugal, prone to flash floods driven by urbanization and short but intense rainfall events typical of the Mediterranean region. Flood extent and flood depth are assessed by manually coupling the hydrologic HEC-HMS and hydraulic HEC-RAS models. The coupled model was run for single rainfall events with recurrence periods of 10−, 20−, 50−, and 100−years, considering four simulation scenarios: current conditions (without NBS), and with an upslope NBS, a downslope NBS, and a combination of both. The model-simulation approach provides good estimates of flood magnitude (NSE = 0.91, RMSE = 0.08, MAE = 0.07, R2 = 0.93), and shows that diverting streamflow into abandoned fields has positive impacts in mitigating downslope flood hazard. The implementation of an upslope NBS can decrease the water depth at the catchment outlet by 0.02 m, whereas a downslope NBS can reduce it from 0.10 m to 0.23 m for increasing return periods. Combined upslope and downslope NBS have a marginal additional impact in reducing water depth, ranging from 0.11 m to 0.24 m for 10− and 100−year floods. Decreases in water depth provided by NBS are useful in flood mitigation and adaptation within the peri-urban catchment. A network of NBS, rather than small isolated strategies, needs to be created for efficient flood-risk management at a larger scale.
    2020-10-16Journal article Open access Show more