Hydrolytic Activity of Castor Bean Powder: Effect of Gum Arabic,Lipase and Oil Concentrations

Lipase activity from castor bean seed powders was evaluated in hydrolysis reactions at 37 °C. The effects of different concentrations of lipase powder (LP), substrate (high oleic sunflower oil, O) and surfactant (gum arabic, A) on lipase activity (R) were assessed using experimental designs. Considered variable bounds were: 0.05–0.15 g_LP, 0.07–0.20 oil:aqueous phase (w/w) and 0–0.025 g gum arabic/mL. All variables had significant effects on the transformed response, R ^1/2. The most important result was the negative effect of gum arabic in lipase activity, even when high oil concentrations were used. Experimental lipase activities involved in this work were within 0.32–16.90 mmol_FFA/g_oil·g_LP·h. Using 0.05 g_LP and 0.20 oil:aqueous phase (w/w) without gum arabic, the activity of 20.47 ± 7.19 mmol_FFA/g_oil·g_LP·h was reached.     

Boundary Handling at Cloth–Fluid Contact

We present a robust and efficient method for the two‐way coupling between particle‐based fluid simulations and infinitesimally thin solids represented by triangular meshes. Our approach is based on a hybrid method that combines a repulsion force approach with a continuous intersection handling to guarantee that no penetration occurs. Moreover, boundary conditions for the tangential component of the fluid's velocity are implemented to model the different slip conditions. The proposed method is particularly useful for dynamic surfaces, like cloth and thin shells. In addition, we demonstrate how standard fluid surface reconstruction algorithms can be modified to prevent the calculated surface from intersecting close objects. For both the two‐way coupling and the surface reconstruction, we take into account that the fluid can wet the cloth. We have implemented our approach for the bidirectional interaction between liquid simulations based on Smoothed Particle Hydrodynamics (SPH) and standard mesh‐based cloth simulation systems.     

Analog VLSI neural networks: implementation issues and examples inoptimization and supervised learning

Time-critical neural network applications that require fully parallel hardware implementations for maximal throughput are considered. The rich array of technologies that are being pursued is surveyed, and the analog CMOS VLSI medium approach is focused on. This medium is messy in that limited dynamic range, offset voltages, and noise sources all reduce precision. The authors examine how neural networks can be directly implemented in analog VLSI, giving examples of approaches that have been pursued to date. Two important application areas are highlighted: optimization, because neural hardware may offer a speed advantage of orders of magnitude over other methods; and supervised learning, because of the widespread use and generality of gradient-descent learning algorithms as applied to feedforward networks     

Shelf life of cashew nut kernels packed in banana starch-based nanocomposites

Starch-based films incorporated with cellulose nanofibres (CNFs) were tested as packaging to improve the stability of cashew nut kernels (CNKs). CNKs were conditioned in four packings: commercial polyethylene film (PEF), starch film (CF), nanocomposite CHF (starch + CNFs from chemical hydrolysis) and nanocomposite EHF (starch + CNFs from enzymatic hydrolysis). Effect of the packaging methods on peroxides value (POV), acidity value (AV), weight gain (WG), water activity (Aw), hardness and colour properties of the CNKs was investigated. CNKs packed with CHF and EHF showed lower POV (0.91 and 0.92 meq_peroxide/kg_sample, respectively) after 21 days of storage than other packed (1.07–1.13 meq_peroxide/kg_sample) and unpacked samples (1.32 meq_peroxide/kg_sample). CNKs packaged with nanocomposites presented similar WG to samples packaged with PEF and lower values than unpackaged CNKs. Biodegradable nanocomposites films showed potential to be used as packaging for food product, being an effective material for extending oilseeds shelf life.     

Nanodelivery of the Gramicidin Peptide for Enhancing Antimicrobial Activity

Gramicidin S (GraS) is an amphiphilic peptide that has emerged as an effective alternative antibiotic. However, its applicability is restricted for clinical uses due to its effect on eukaryotic cells and low aqueous solubility. In this work, a novel water-soluble peptide formulation with bactericidal activity is developed by the incorporation of Gramicidin S in the lipid bilayer of liposomes (L-GraS). As a result, GraS included in the lipid vesicles is stabilized in aqueous medium and showed antimicrobial activity against Staphylococcus aureus. In addition, L-GraS reveals enhanced biocompatibility with mammalian cells in comparison with the free peptide. Molecular dynamics simulations shed light on the collective behavior between GraS peptides and liposomes from a molecular approach. The molecular dynamic simulations are in agreement with experimental results and further confirm the effective incorporation of GraS in the liposomes, letting understand the best formulation procedure of the vesicles. Therefore, the L-GraS nanosystem presented here is an interesting alternative to conventional antibiotics, with less restrictions and promising features to improve current therapies. Practical Applications: Incorporation of GraS in liposomes is an interesting approach to increase the solubility of the peptide, thus expanding its therapeutic horizon as a promising alternative to combat bacterial colonization especially in wound infections.     

Escaping the Trough: Towards Real-World Impact of Tabletop Research

In the past decade, there has been increasing interest in studying tabletop technologies in HCI. Using the Gartners Hype Cycle as an analytical framework, this article presents developments in tabletop research within the last decade. The objective is to determine the level of maturity of tabletop technologies with respect to the research foci and the extent to which tabletops have shown their worth in real world settings. We identify less studied topics in the current body of literature with the primary aim of evoking further discussions of the current and future research challenges. We analyzed 542 research publications and categorized these according to eight types of research foci. Findings show that only 3% of all studies are conducted in natural settings, i.e. there is a clear tendency to emphasize laboratory evaluations of tabletop technology. Also, very few studies demonstrate relative benefits of tabletops over other technologies in collaborative settings (1%). We argue for a need to increase emphasis on understanding real-world use and impact rather than developing new tabletop technologies.     

Indoor persistent organic pollutants in agricultural areas from Argentina

Persistent Organic Pollutants (POPs) are anthropogenic chemicals extensively used in the past for industrial and agricultural purposes, characterized by their lipophilicity, ubiquity, volatility and environmental persistence. By other hand, chlorpyrifos is the most widely used current pesticide (CUPs) being the main insecticide used for crops in Argentina. The aim of this work was to assess levels of POPs and CUPs in different fractions of airborne particles collected indoor in agricultural areas from Argentina. Particles higher than 2.5 µm were trapped in polyurethane foams (PUF) while particles smaller than 1 µm and volatile compounds were adsorbed on activated charcoal. Compounds were analyzed by gas chromatograph with electron capture detector (GC-ECD). Endosulfans, chlordanes, PCBs, and HCHs were detected in all PUF samples, while endosulfans, chlorpyrifos, PCBs, and HCHs were the most abundant in smaller particles. Majority of pesticides showed higher concentrations during the summer season (1397.7 vs 832.5 pg/m³). Even adding up all measured organic compounds, no sample reaches the threshold limit value for indoor pesticides levels (0.1 pg/m³), neither in the large or small particle fraction. However, the fact that chronic exposure to POPs has been linked to several diseases raises concern for human health.