Dynamic Smagorinsky model on anisotropic grids

Large Eddy Simulation (LES) of complex-geometry flows often involves highly anisotropic meshes. To examine the performance of the dynamic Smagorinsky model in a controlled fashion on such grids, simulations of forced isotropic turbulence are performed using highly anisotropic discretizations. The resulting model coefficients are compared with a theoretical prediction (Scotti et al., 1993). Two extreme cases are considered: pancake-like grids, for which two directions are poorly resolved compared to the third, and pencil-like grids, where one direction is poorly resolved when compared to the other two. For pancake-like grids the dynamic model yields the results expected from the theory (increasing coefficient with increasing aspect ratio), whereas for pencil-like grids the dynamic model does not agree with the theoretical prediction (with detrimental effects only on smallest resolved scales). A possible explanation of the departure is attempted, and it is shown that the problem may be circumvented by using an isotropic test-filter at larger scales. Overall, all models considered give good large-scale results, confirming the general robustness of the dynamic and eddy-viscosity models. But in all cases, the predictions were poor for scales smaller than that of the worst resolved direction

Influence of glucocorticoid and betamimetic therapy on milk secretory IgA concentration produced by mothers delivering preterm infants

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Anthropogenic fibers and microplastics in the pelagic gooseneck barnacle Lepas (Lepas) anatifera in Capo Milazzo Marine Protected Area (Tyrrhenian Sea): A first characterization

This study provides an assessment of the efficiency of the biofouler Lepas (Lepas) anatifera Linnaeus, 1758 in capturing microplastics and microfiber particles floating in the water column. In this context, we collected pelagic gooseneck barnacles at fixed moorings in the Capo Milazzo Marine Protected Area (MPA). Fibers and fragments were found in the digestive tract of 30% of the 120 specimens collected. The ingested debris were mainly fibers (85.9%) of synthetic (30.6%) and natural (11.7%) origin, with length ranging between 1 and 2 mm (33.3%) and transparent (47.2%). The highest concentration of fibers was recorded in barnacles collected in the western sector of the MPA that is more affected by the input of organic matter coming from several urban wastewaters. No correlation was found between the presence of artificial polymers in L. (Lepas) anatifera and the size of individuals. The great diversity of fibers and plastic fragments by typology, size, shape and color, as well as the large number of bivalve and ostracod shells found in the digestive tract of the samples, confirm the opportunistic diet of these organisms, which can indiscriminately ingest any type of prey and cannot distinguish between microplastics and food. The results obtained, as well as the wide distribution and abundance, and ease of sampling of these barnacle species in macrofouling suggest that including this species in monitoring programs could be a cost-effective and easy method for assessing the presence of microplastics and microfibers in coastal marine waters to monitor the ecological status of pelagic and coastal ecosystems, including MPAs

Charge density waves enhance the electronic noise of manganites

The transport and noise properties of Pr_{0.7}Ca_{0.3}MnO_{3} epitaxial thin films in the temperature range from room temperature to 160 K are reported. It is shown that both the broadband 1/f noise properties and the dependence of resistance on electric field are consistent with the idea of a collective electrical transport, as in the classical model of sliding charge density waves. On the other hand, the observations cannot be reconciled with standard models of charge ordering and charge melting. Methodologically, it is proposed to consider noise-spectra analysis as a unique tool for the identification of the transport mechanism in such highly correlated systems. On the basis of the results, the electrical transport is envisaged as one of the most effective ways to understand the nature of the insulating, charge-modulated ground states in manganites.Comment: 6 two-column pages, 5 figure

Treating Chronic Wounds Using Photoactive Metabolites: Data Mining the Chinese Pharmacopoeia for Potential Lead Species (#)

Efficient wound treatment that addresses associated infections and inflammation remains one of the big unmet needs, especially in low- and middle-income countries. One strategy for securing better healthcare can be using medicinal plants if sufficient evidence on their safety and therapeutic benefits can be ascertained. A unique novel opportunity could be photo-enhanced wound treatment with a combination of light-sensitive plant preparations and local exposure to daylight. Data mining strategies using existing resources offer an excellent basis for developing such an approach with many potential plant candidates. In the present analysis, we researched the 535 botanical drugs included in the Chinese pharmacopeia and identified 183 medicinal plant species, 82 for treating open wounds caused by trauma and 101 for inflammatory skin conditions. After further screening for reports on the presence of known photoactive compounds, we determined a core group of 10 scientifically lesser-known botanical species that may potentially be developed into more widely used topical preparations for photodynamic treatment of infected wounds. Our predictive approach may contribute to developing a more evidence-based use of herbal medicines

Medicinal plants from the Himalayan region as potential novel antimicrobial and anti-inflammatory skin treatments

Background and Objectives: Adequate treatment of wounds remains one of the major medical needs globally, most notably in the regions with poor or limited access to health care. In many local and traditional systems of medicine, plants are often widely used for treating infected wounds. / Aim and objectives: The overarching aim of this project was selection of potential species for use in a future treatment by combining with plant resources with aspects of antimicrobial photodynamic therapy (aPDT). Specifically, we focussed on species used locally in the Himalayan region for the treatment of skin disorders and then assessed the existing pharmacological evidence for key species based on the published evidence available. / Methods: Database searches were performed to identify relevant publications describing local and traditional uses of plants in the Himalayan region of Bhutan, PR China, India, Nepal and Pakistan. Using the Global Biodiversity Information Facility (GBIF), species were researched in terms of their distribution including in different climatic regions, focussing on species mostly found in higher climatic zones (based on the Köppen–Geiger climate classification). For species used in three or more countries and restricted to the higher altitudes, data on safety, pharmacology, as it relates to dermatological conditions, and phytochemistry were retrieved. / Key findings: The study identified a total of 606 species that are used in the treatment of various skin conditions often associated with infections reported in 84 articles. Common weeds like Ageratum conyzoides and Bidens pilosa, widely used and cultivated species like Centealla asiatiaca and Prunus armenica were excluded. This ultimately led to the identification of a core group of five widely used species restricted to the Himalayan region (Cedrus deodara, Nardostachys jatamansi, Pinus wallichiana, Pinus roxburghii and Valeriana jatamansi). / Conclusions: Here we apply a novel approach comprising an assessment of the published information on the use of medicinal plants (i.e. local and traditional knowledge) in the context of their potential to be used in a biomedical form of clinical treatment – aPDT. Then, once sustainable sourcing based on access and benefit-sharing arrangements is in place, these species are investigated for their potential in wound treatment. Ultimately, the goal is to develop a new baseline for primary health care in some of the regions of the world with poor or limited access to health care

Predominant-period site classification for response spectra prediction equations in Italy

We propose a site-classification scheme based on the predominant period of the site, as determined from the average horizontal-to-vertical (H/V) spectral ratios of ground motion. Our scheme extends Zhao et al.(2006) classifications by adding two classes, the most important of which is defined by flat H/V ratios with amplitudes less than 2. The proposed classification is investigated by using 5%-damped response spectra from Italian earthquake records. We select a dataset of 602 three-component analog and digital recordings from 120 earthquakes recorded at 214 seismic stations within a hypocentral distance of 200 km. Selected events are in the moment-magnituderange 4.0 ≤ Mw ≤ 6.8 and focal depths from a few kilometers to 46 km. We computed H/V ratios for these data and used them to classify each site into one of six classes. We then investigate the impact of this classification scheme on empirical ground-motion prediction equations (GMPEs) by comparing its performance with that of the conventional rock/soil classification. Although the adopted approach results in only a small reduction of the overall standard deviation, the use of H/V spectral ratios in site classification does capture the signature of sites with flat frequency-response, as well as deep and shallow-soil profiles, characterized by long- and short-period resonance, respectively; in addition, the classification scheme is relatively quick and inexpensive, which is an advantage over schemes based on measurements of shear wave velocity

Dynamic Smagorinsky model on anisotropic grids

To examine the performance of the dynamic Smagorinsky model in a controlled fashion on anisotropic grids, simulations of forced isotropic turbulence are performed using highly anisotropic discretizations. The resulting model coefficients are compared with an earlier prediction. Two extreme cases are considered: pancake-like grids, for which two directions are poorly resolved compared to the third, and pencil-like grids, where one direction is poorly resolved when compared to the other two