Species distribution,molecular characteristics and vancomycin resistance gene profiles of Enterococcus sp. isolates from farmhouse cheeses in western Turkey

Species distribution, virulence traits and vancomycin resistance gene profiles of Enterococcus isolated from 43 home‐made artisan cheese samples collected from open markets, located in Aydin region of Turkey, were investigated. Of the 129 isolates, 95 were identified as Enterococcus sp.; Enterococcus faecium being the most prevalent species (82.1%), followed by Enterococcus faecalis (13.6%) and Enterococcus durans (1.0%). None of the enterococci were harbouring vanA or vanC, while seven isolates (7.3%) were shown to harbour vanB gene by multiplex PCR. gelE (49.4%) being the most prevalent virulence factor was followed by asa1 (27.3%), esp (22.1%), cylA (4.2%) and hyl (3.1%).     

Manipulating Nanoscale Features on the Surface of Dye‐Loaded Microbubbles to Increase Their Ultrasound‐Modulated Fluorescence Output

The nanoscale surface features of lipid‐coated microbubbles can dramatically affect how the lipids interact with one another as the microbubble diameter expands and contracts under the influence of ultrasound. During microbubble manufacturing, the different lipid shell species naturally partition forming concentrated lipid islands. In this study the dynamics of how these nanoscale islands accommodate the expansion of the microbubbles are monitored by measuring the fluorescence intensity changes that occur as self‐quenching lipophilic dye molecules embedded in the lipid layer change their distance from one another. It was found that when the dye molecules were concentrated in islands, less than 5% of the microbubbles displayed measurable fluorescence intensity modulation indicating the islands were not able to expand sufficiently for the dye molecules to separate from one another. When the microbubbles were heated and cooled rapidly through the lipid transition temperature the islands were melted creating an even distribution of dye about the surface. This resulted in over 50% of the microbubbles displaying the fluorescence‐modulated signal indicating that the dye molecules could now separate sufficiently to change their self‐quenching efficiency. The separation of the surface lipids in these different formations has significant implications for microbubble development as ultrasound and optical contrast agents.     

Acceleration waves in elastic dielectrics with polarization gradient effects

In this paper the propagation of acceleration waves arbitrary form propagating into a deformed eleastic dielectric with polarization effect is investigated. An acceleration wave is defined as a second order propagating surface of discontinuity on which the position vector, the polarization vector and Maxwell potential, and their first order derivatives with respect to time and space coordinates are continuous while the second order derivatives of these quantities may suffer jumps but are continuous everywhere else. By computing the jumps of the balance equations on the singular surface, implicit equations for wave speeds corresponding to non-zero amplitudes of the acceleration wave are obtained. It is noteworthy that the second order derivatives of Maxwell potential are also continuous across the acceleration wave.The same equation for wave speeds are also derived for isotropic elastic dielectrics. The wave speeds for longitudinal and transverse waves are obtained in explicit forms and the conditions of existence for real wave speeds are investigated.     

A comparative study of the adsorption and desorption of o-xylene onto bentonite clay and alumina

In this paper, adsorptive performance of natural clay of bentonite type has been investigated as a potential VOC adsorbent on the basis its promising physical-chemical and morphological properties which were compared to commercial gamma-Al(2)O(3) solid. The vapour-solid adsorption isotherms of xylene were measured at different temperatures ranging from 300 to 373 K using dynamical method and the obtained data confronted to classical models such as Langmuir and Freundlich. On the other hand, the solids physico-chemical characteristics and adsorptive performances were correlated to some cost aspects because of their importance for design and engineering of adsorption plant. The results shows the interest of a local clay natural of bentonite type for treatment of VOCs emitted in working places regarding its performances and lower cost.     

Thermal conductivity and thermal boundary resistance of nanostructures

   

We present a fabrication process of low-cost superlattices and simulations related with the heat dissipation on them. The influence of the interfacial roughness on the thermal conductivity of semiconductor/semiconductor superlattices was studied by equilibrium and non-equilibrium molecular dynamics and on the Kapitza resistance of superlattice's interfaces by equilibrium molecular dynamics. The non-equilibrium method was the tool used for the prediction of the Kapitza resistance for a binary semiconductor/metal system. Physical explanations are provided for rationalizing the simulation results.     

Enhanced Sintering of TiNi Shape Memory Foams under Mg Vapor Atmosphere

TiNi alloy foams are promising candidates for biomaterials to be used as artificial orthopedic implant materials for bone replacement applications in biomedical sector. However, certain problems exist in their processing routes, such as formation of unwanted secondary intermetallic phases leading to brittleness and deterioration of shape memory and superelasticity characteristics; and the contamination during processing resulting in oxides and carbonitrides which affect mechanical properties negatively. Moreover, the eutectic reaction present in Ti-Ni binary system at 1391?K (1118?°C) prevents employment of higher sintering temperatures (and higher mechanical properties) even when equiatomic prealloyed powders are used because of Ni enrichment of TiNi matrix as a result of oxidation. It is essential to prevent oxidation of TiNi powders during processing for high-temperature (>1391?K i.e., 1118?°C) sintering practices. In the current study, magnesium powders were used as space holder material to produce TiNi foams with the porosities in the range of 40 to 65?pct. It has been found that magnesium prevents secondary phase formation and contamination. It also prevents liquid phase formation while enabling employment of higher sintering temperatures by two-step sintering processing: holding the sample at 1373?K (1100?°C) for 30?minutes, and subsequently sintering at temperatures higher than the eutectic temperature, 1391?K (1118?°C). By this procedure, magnesium may allow sintering up to temperatures close to the melting point of TiNi. TiNi foams produced with porosities in the range of 40 to 55?pct were found to be acceptable as implant materials in the light of their favorable mechanical properties.     

Some physicochemical properties and mineral contents of stirred yoghurts containing different fruit marmalades

In this study chemical properties and mineral levels of yoghurts containing different fruit marmalades were investigated. Cherry laurel, loquat fruit and kiwi marmalade were used to make the stirred yoghurts, and the calcium, phosphorus, sodium, magnesium, manganese, iron, zinc, copper, boron, lead, nickel, molybdenum, chromium, cadmium, cobalt levels were determined by an inductively coupled plasma optical emission spectrometer (ICP–OES). The total solid, fat, ash, pH, viscosity and syneresis contents of the yoghurt samples changed between 13.85–21.02%, 2.45–2.90%, 0.82–0.94%, 4.11–4.22, 2104–2454 cP and 42.0–47.0 mL/100 g, respectively. The mean concentrations in the yoghurts of these minerals were 104.66–118.94 calcium, 95.81–112.42 phosphorus and 13.47–15.04 magnesium as mg/100 g, 235.00–254.00 iron, 429.00–453.00 zinc and 70.45–122.90 copper as μg/100 g. The recommended dietary allowance (RDA) was calculated on the basis of the intake of one yoghurt portion (125 g).     

A fully automatic CAD-CTC system based on curvature analysis for standard and low-dose CT data

Computed tomography colonography (CTC) is a rapidly evolving noninvasive medical investigation that is viewed by radiologists as a potential screening technique for the detection of colorectal polyps. Due to the technical advances in CT system design, the volume of data required to be processed by radiologists has increased significantly, and as a consequence the manual analysis of this information has become an increasingly time consuming process whose results can be affected by inter- and intrauser variability. The aim of this paper is to detail the implementation of a fully integrated CAD-CTC system that is able to robustly identify the clinically significant polyps in the CT data. The CAD-CTC system described in this paper is a multistage implementation whose main system components are: 1) automatic colon segmentation; 2) candidate surface extraction; 3) feature extraction; and 4) classification. Our CAD-CTC system performs at 100% sensitivity for polyps larger than 10 mm, 92% sensitivity for polyps in the range 5 to 10 mm, and 57.14% sensitivity for polyps smaller than 5 mm with an average of 3.38 false positives per dataset. The developed system has been evaluated on synthetic and real patient CT data acquired with standard and low-dose radiation levels.     

A hybrid mobile object tracker based on the modified Cuckoo Search algorithm and the Kalman Filter

Most revolutionary algorithms are inspired from the behavior of natural species. This inspiration can be drawn from their reproductive behavior, flying mode, or even their ways of communication. One of the most efficient metaheuristics in a discrete search space is the Cuckoo Search algorithm, inspired by the Cuckoo?s reproductive behavior and combined with the Lévy flight pattern adopted by many animals and insects. In this paper, we present a new tracking approach, the Hybrid Kalman Cuckoo Search tracker, using a modified version of the Cuckoo Search algorithm combined with the well-known Kalman Filter. The Cuckoo Search algorithm is combined with the prediction step adopted by the Kalman Filter to enhance the initial population?s quality. Using the Hybrid Kalman Cuckoo Search tracker, we can efficiently explore the search space in order to locate an object?s position from one frame to the next. The Lévy flight model is also modified in order to re-adapt the Lévy step size as the algorithm approaches the desired solution. The Hybrid Kalman Cuckoo Search tracker is tested on a variety of datasets including one where we incorporated different situations, as well as some videos from the CAVIAR, SPEVI, and other datasets. The comparative study results show that the proposed algorithm outperforms the Particle Swarm Optimization based tracker, especially in terms of computation time.     

Modelling of a Cd<Subscript>1−x</Subscript>Zn<Subscript>x</Subscript>Te/ZnTe Single Quantum Well for Laser Diodes

In this paper, the carrier density, temperature and quantum well width effect have been investigated for the optical gain for a Cd_1?xZn_xTe/ZnTe Zinc-blend strained quantum well structure. The device emits laser radiations in green–yellow–orange. Our results showed that the optical gain significantly increases with the increasing of the carrier density. It also increases with the decreasing of the Zn concentration, the well width and the temperature. In addition, the optimal threshold current density values were determined for three alloy compositions as 0.7, 0.8 and 0.9.