Political Expression and Action on Social Media: Exploring the Relationship Between Lower‐ and Higher‐Threshold Political Activities Among Twitter Users in Italy

Scholars and commentators have debated whether lower‐threshold forms of political engagement on social media should be treated as being conducive to higher‐threshold modes of political participation or a diversion from them. Drawing on an original survey of a representative sample of Italians who discussed the 2013 election on Twitter, we demonstrate that the more respondents acquire political information via social media and express themselves politically on these platforms, the more they are likely to contact politicians via e‐mail, campaign for parties and candidates using social media, and attend offline events to which they were invited online. These results suggest that lower‐threshold forms of political engagement on social media do not distract from higher‐threshold activities, but are strongly associated with them.     

AFID: an automated approach to collecting software faults

We present a new approach for creating repositories of real software faults. We have developed a tool, the Automatic Fault IDentification Tool (AFID), that implements this approach. AFID records both a fault revealing test case and a faulty version of the source code for any crashing faults that the developer discovers and a fault correcting source code change for any crashing faults that the developer corrects. The test cases are a significant contribution, because they enable new research that explores the dynamic behaviors of the software faults. AFID uses an operating system level monitoring mechanism to monitor both the compilation and execution of the application. This technique makes it straightforward for AFID to support a wide range of programming languages and compilers.     

The potential of small-scale fusion experiments and the Gordon-Taylor equation to predict the suitability of drug/polymer blends for melt extrusion

The aim of this study was to investigate the use of small-scale fusion experiments and the Gordon-Taylor (GT) equation to predict whether melt extrusion of a drug with an amorphous polymer produces a stable amorphous dispersion with increased drug dissolution. Indomethacin, lacidipine, nifedipine, piroxicam, and tolbutamide were used as poorly soluble drugs. Drug/polyvinylpyrrolidone (PVP) blends were prepared at a 1:1 mass ratio. Small-scale fusion experiments were performed in a differential scanning calorimeter (DSC) and in stainless steel beakers. Extrusion was performed in a Brabender Plasti-corder. The glass transition temperatures T_g were determined by DSC. Taking an average T_g from the DSC melt, beaker melt, and GT equation accurately predicted the extrudate T_g. Physical stability of beaker melt and extrudate samples was tested by X-ray powder diffraction (XRPD) and DSC after storage at 30°C (beaker melt) or 25°C (extrudate) and less than 10%, 60%, and 75% relative humidity (RH). Beaker melts were amorphous, apart from some residual crystallinity. Extrudates were amorphous after preparation. Except for indomethacin/PVP, which remained amorphous, the crystallinity of beaker melts and extrudates increased only at 75% RH. Recrystallization occurred even when the T_g of the sample was well above the storage temperature. Chemical stability of the beaker melts and extrudates was tested by capillary electrophoresis and high-performance liquid chromatography (HPLC). Stability was slightly improved in the extrudate compared to the beaker melt. In general, the order for rate of dissolution was crystalline drug was less than the physical mixture, which was less than the drug/PVP beaker melt, which was approximately equal to the extrudate. The use of beaker melts allows a conservative estimate of the potential to melt extrude a drug. To predict physical stability, analysis of the T_g must be combined with physical stability experiments.     

Characterizing colloidal structures of pseudoternary phase diagrams formed by oil/water/amphiphile systems

Two pseudoternary phase diagrams were constructed using ethyl oleate, water, and a surfactant blend containing poly (oxyethylene 20) sorbitan monooleate and sorbitan monolaurate with or without the cosurfactant 1-butanol. Two colloidal regions were identified in the cosurfactant-free phase diagram; a microemulsion (ME) and a region containing lamellar liquid crystals (LC). The addition of 1-butanol increased the area in which systems formed microemulsions and eliminated the formation of any liquid crystalline phases. Samples that form the colloidal regions of both systems were investigated by freeze-fracture transmission electron microscopy and by viscosity and conductivity measurements. The three techniques were compared and evaluated as characterisation tools for such colloidal systems and also to identify transitions between the colloidal systems formed. A droplet ME was present at a low water volume fraction (phi w) in both systems (phi w < 0.15) as revealed by electron microscopy. At higher phi w values, LC structures were observed in micrographs of samples taken from the cosurfactant-free system while the structure of samples from the cosurfactant-containing system was that of a bicontinuous ME. The viscosity of both systems increased with increasing phi w to 0.15 and flow was Newtonian. However, formation of LC in the cosurfactant-free system resulted in a dramatic increase in viscosity that was dependent on phi w and a change to pseudoplastic flow. In contrast, the viscosity of the bicontinuous ME was independent of phi w. Three different methods were used to estimate the percolation threshold from the conductivity data for the cosurfactant-containing system. The use of nonlinear curve fitting was found to be most useful yielding a value close to 0.15 for the phi w.     

Development of Multi-chroic MKIDs for Next-Generation CMB Polarization Studies

We report on the status of an ongoing effort to develop arrays of horn-coupled, polarization-sensitive microwave kinetic inductance detectors (MKIDs) that are each sensitive to two spectral bands between 125 and 280 GHz. These multi-chroic MKID arrays are tailored for next-generation, large-detector-count experiments that are being designed to simultaneously characterize the polarization properties of both the cosmic microwave background and Galactic dust emission. We present our device design and describe laboratory-based measurement results from two 23-element prototype arrays. From dark measurements of our first engineering array, we demonstrated a multiplexing factor of 92, showed the resonators respond to bath temperature changes as expected, and found that the fabrication yield was 100%. From our first optically loaded array, we found the MKIDs respond to millimeter-wave pulses; additional optical characterization measurements are ongoing. We end by discussing our plans for scaling up this technology to kilo-pixel arrays over the next 2 years.     

Automation in cervical cancer screening. Part 1: fixed cell scanning systems

Cytology automation is highly desirable if a mass cancer screening system is to be effective, and has been the subject of widespread research and development effort. Several experimental systems have been developed based on fixed cell scanning or flow techniques, but clinical trials have produced disappointing results. The major problem with these early systems has been that of false positive "abnormal cell" signals caused by cell overlaps and artifacts. Most current research is devoted to the development of better techniques for cell presentation, to the improvement of pattern recognition techniques, and to the exploitation of novel cell parameters in flow systems.     

Mechanical Properties of Hemp‐Fibre‐Reinforced Euphorbia Composites

A composite material consisting of hydroxide‐modified hemp fibres and euphorbia resin was produced. The composites were tested in tension, short‐beam interlaminar shear stress and in impact. There was an increase in the tensile strength and modulus for resins with high‐hydroxyl‐group based composites. Similar results were obtained for interlaminar shear stress while low‐hydroxyl group euphorbia resin based composites exhibited high impact strength. The euphorbia resin with high hydroxyl content yielded composites with high stiffness. The use of euphorbia‐based resins in composite manufacture increases the value of the euphorbia oil as well as creating a new route of composite manufacturing.

     

Cleaning properties of single-phase hydrocarbon-based microemulsion systems

Single-phase hydrocarbon-based microemulsions with low volatile organic carbon levels can help deliver solvent-like cleaning properties while allowing formulators to meet regulatory requirements. The rheology and petroleum jelly solubilization properties of model microemulsion systems that contained equal volumes of hydrocarbon solvent and water were evaluated as a function of microemulsion structure and composition. Single-phase microemulsions with low surfactant contents and broad formulation flexibility were obtained through the use of efficient anionic surfactants and low electrolyte levels. The microemulsion structure was advanced from solvent-continuous to water-continuous by varying the solvent alkane carbon number or the electrolyte content, whereas the liquid crystal content was controlled via cosurfactant concentration. Both microemulsion structure and viscosity influenced solubilization rates. Low-viscosity, solvent-continuous microemulsions showed solubilization rates comparable to those found with solvent-based systems, while water-continuous microemulsions showed relatively poor solubilization rates. Microemulsions containing dispersed liquid crystals exhibited high viscosity and low solubilization rates.     

Electrochemical behavior and determination of the insecticide synergist piperonyl butoxide

Piperonyl butoxide may be reversibly oxidized in acetonitrile at a glassy carbon electrode to a cation radical under short time scale voltammetric conditions, e.g., cyclic voltammetry when the potential scan rate is above 500 mV s(-)(1). During longer time domain experiments, the cation radical decays in a rate-limiting heterolytic bond cleavage step and subsequent transfer of a second electron at the potential of the first process. Additionally, a second oxidation process develops at more positive potentials. One product isolated from the initial oxidation process in an almost quantitative yield, under controlled potential electrolysis conditions, is 6-n-propyl-1,3-benzodioxole-5-carboxaldehyde. This carboxaldehyde is oxidized at the same positive applied potential as the second oxidation process observed in long time domain voltammetric experiments with piperonyl butoxide. The limit of detection for piperonyl butoxide in acetonitrile, using differential pulse voltammetry at a glassy carbon electrode, is 1.6 × 10(-)(6) M (3σ), with a limit of determination of 4.1 × 10(-)(6) M (10σ). Piperonyl butoxide was selectively determined using differential pulse voltammetry with a concentration of 5.11 ± 0.02 g L(-)(1) in a commercial insecticide formulation containing pyrethrins. This result is in good agreement with the manufacturer's stated concentration of 5.07 g L(-)(1). The sample preparation requires only simple dilution of the formulation in an acetonitrile/dichloromethane (95:5) solvent mixture.     

LES of Impingement Heat Transfer on a Concave Surface

Wall-resolved and zonal numerical large eddy type simulations are performed for a round jet impinging on a concave hemisphere at Re = 23,000. The zonal method uses a near-wall k–l model and a Hamilton-Jacobi equation to match this to the large eddy simulation zone. To minimize numerical dissipation, a self-adaptive discretization (SDS) scheme is examined. Both second- (n = 2) and sixth- (n = 6) order-based central discretization schemes are tested. The characteristics of the schemes is assessed using two test cases: the development of a subcritical Tollmien-Schlichting (T-S) stability wave in a plane channel and the decay of homogenous, isotropic turbulence (DHIT). It is found, that Smagorinsky LES simulations tend to be too dissipative in the high wave-number region, even with the SDS scheme; hence, the SGS model is omitted. Significant flow feedback is observed for the hemisphere case. Both shear-layer excitation and stabilization is observed. Computed wall pressure coefficients for the zonal NLES method are encouraging; for the wall-resolved case the stagnation region value is overpredicted. Heat transfer for the wall-resolved and zonal large eddy simulations are encouraging. For both quantities the difference between the n = 2 and n = 6 schemes is small, and the modeling approach used appears to be more influential. It is concluded that the presence of feedback mechanisms should be considered when designing experiments and/or numerical simulations for this case, and that the importance of boundary conditions for LES should not be neglected.