Effect of Ozone on Engorged Rhipicephalus microplus (Acari: Ixodidae) Females During the Pre-Laying Period

The Rhipicephalus microplus is an important ectoparasite of livestock as it results in loss to the producer. The present study analyzed the effects of ozone gas, a fluid with acaricidal potential, on this species of cattle tick. Engorged females of R. microplus were divided into two groups: control, oxygen and ozone groups. The results indicated that ticks in the control and oxygen groups maintained the oviposition process intact. Females exposed to the ozone gas died before eggs were deposited and damage on the cuticle was observed, proving that the ozone gas had an acaricidal effect on the ticks.     

Effect of the rigid segment content on the properties of segmented polyurethanes conjugated with atorvastatin as chain extender

Segmented polyurethanes were prepared with polycaprolactone diol as soft segment and various amounts of 4,4´-Methylenebis(cyclohexyl isocyanate) and atorvastatin, a statin used for lowering cholesterol, in order to obtain SPU with different content of rigid segments. Polyurethanes with 35% or 50% of rigid segment content were physicochemically characterized and their biocompatibility assessed with L929 fibroblasts. High concentrations of atorvastatin were incorporated by increasing the content of rigid segments as shown by FTIR, Raman, NMR, XPS and EDX. Thermal and mechanical characterization showed that polyurethanes containing atorvastatin and 35% of rigid segments were low modulus (13?MPa) semicrystalline polymers as they exhibited a glass transition temperature (T_g) at ?38?°C, melting temperature (T_m) at 46?°C and crystallinity close to 35.9% as determined by DSC. In agreement with this, X-ray diffraction showed reflections at 21.3° and 23.6° for PCL without reflections for atorvastatin suggesting its presence in amorphous form with higher potential bioavailability. Low content of rigid segments led to highly degradable polymer in acidic, alkaline and oxidative media with an acceptable fibroblast cytotoxicity up to 7 days possibly due to low atorvastatin content.     

Determination of the composition and thickness of chromel and alumel thin films on different substrates by quantitative energy dispersive spectroscopy analysis

Thin films of two alloys (chromel and alumel), with thickness less than 100 nm, were obtained by plasma deposition technique, namely filtered cathodic vacuum arc (FCVA). The elemental analyses were performed by quantitative energy dispersive spectroscopy (EDS) microanalysis and Rutherford backscattering spectrometry (RBS). The applicability of EDS to such thin films as these was established by analysis of films deposited on substrates of different atomic numbers, specifically vitreous carbon, silicon, copper, and tin. We found that a substrate with atomic number similar to the mean atomic number of the film constituents is best for reliable EDS results, when compared to RBS. The compatibility between quantitative EDS measurements and RBS measurements, as well as comparison between the thin film elemental composition and the bulk material composition, was assessed by statistical analysis. Good consistency between EDS and RBS measurements was found for both chromel and alumel thin films when copper was used as substrate material. We observed severely overlapping peaks in the RBS output for the case of alumel films so that EDS analysis was crucial. We also compared thickness measurements determined by EDS and RBS, and we found good agreement for the case of alumel film on copper substrate, and 15% agreement for chromel film on copper substrate.     

Analysing the cognitive effectiveness of the WebML visual notation

WebML is a domain-specific language used to design complex data-intensive Web applications at a conceptual level. As WebML was devised to support design tasks, the need to define a visual notation for the language was identified from the very beginning. Each WebML element is consequently associated with a separate graphical symbol which was mainly defined with the idea of providing simple and expressive modelling artefacts rather than by adopting a rigorous scientific approach. As a result, the graphical models defined with WebML may sometimes prevent proper communication from taking place between the various stakeholders. In fact, this is a common issue for most of the existing model-based proposals that have emerged during the last few years under the umbrella of model-driven engineering. In order to illustrate this issue and foster in using a scientific basis to design, evaluate, improve and compare visual notations, this paper analyses WebML according to a set of solid principles, based on the theoretical and empirical evidence concerning the cognitive effectiveness of visual notations. As a result, we have identified a set of possible improvements, some of which have been verified by an empirical study. Furthermore, a number of findings, experiences and lessons learnt on the assessment of visual notations are presented.     

Designing and building SDN testbeds for energy-aware traffic engineering services

As experimenting with energy-aware techniques on large-scale production infrastructure is prohibitive, a large number of proposed traffic engineering strategies have been evaluated only using discrete-event simulations. The present work discusses (i) challenges towards building testbeds that allow researchers and practitioners to validate and evaluate the performance and quality of energy-aware traffic engineering strategies, (ii) requirements to fulfil when porting simulations to testbeds, and (iii) two proof-of-concept testbeds. One testbed uses and provides software-defined network (SDN) services created on the open-network operating system while the other is a composition of virtual Open vSwitches controlled by the Ryu SDN framework. The aim of the testbeds is to validate previously proposed energy-aware traffic engineering strategies in different environments. We detail the platforms and illustrate how they have been used for performance evaluation. Additionally, the paper compares results obtained in the testbeds with evaluations performed using discrete-event simulations and presents challenges faced while implementing energy-aware traffic engineering mechanisms as SDN services in testbed environments.     

Optimization of the Acceptance of Prebiotic Beverage Made from Cashew Nut Kernels and Passion Fruit Juice

The aim of this research was to develop a prebiotic beverage from a hydrosoluble extract of broken cashew nut kernels and passion fruit juice using response surface methodology in order to optimize acceptance of its sensory attributes. A 2² central composite rotatable design was used, which produced 9 formulations, which were then evaluated using different concentrations of hydrosoluble cashew nut kernel, passion fruit juice, oligofructose, and 3% sugar. The use of response surface methodology to interpret the sensory data made it possible to obtain a formulation with satisfactory acceptance which met the criteria of bifidogenic action and use of hydrosoluble cashew nut kernels by using 14% oligofructose and 33% passion fruit juice.     

Influence of graphitic materials microstructure in the hydrogen evolution in aqueous solution of tetra-alkylammonium-sulfonic acid ionic liquid

Vitreous carbon (VC), pyrolytic carbon (PC) and moulded graphite (MG) were tested as cathodic materials in hydrogen production by water electrolysis in the presence of the ionic liquid tetrafluoroborate of 3-triethylammonium-propane sulfonic acid (TEA-PS.BF₄). The physical characterization of the carbon materials indicated large differences in the microstructure of VC, PC, and MG and this significantly affected their electrochemical response. The mechanism presented for all the materials studied in the hydrogen evolution reaction (HER) was Volmer–Heyrovsky, where the H₂ desorption at the catalytic surface is the determining step. The MG electrode presented an unfavourable performance due to the formation of nanobubbles that coalesced without H₂ desorption and led to the deactivation of the catalytic sites. This behaviour is attributed to the presence of large and ordered crystallites at the material surface, with a greater number of hydrophobic domains in comparison with VC and PC material surfaces. The VC and PC electrodes presented a higher performance compared to the Pt cathode, showing lower activation energy, higher cathodic exchange current and lower charge transfer resistance. The set of results indicates VC and PC as promising alternative materials to constitute cathodes for the electrolysis of water using TEA-PS.BF₄ aqueous solution as electrolyte.     

A multiplier evaluation of primary factors supply–shocks in a regional economy

Demand-side multipliers have ruled within multisectorial models as the main indicators for policy effectiveness and key-sector determination both in linear interindustry analysis and in non-linear applied general equilibrium models. In this paper we shift the perspective to supply-side injections by studying the effects of marshalling additional primary factors (K, L) that give rise to a general resource reallocation. We obtain estimates of supply multipliers by numerically approximating the underlying and unobservable general equilibrium Jacobian matrix. These estimates provide complementary information to standard demand multipliers. We illustrate the methodology using an empirical general equilibrium model for the region of Andalusia, Spain.