An examination of four user-based software evaluation methods

Usability has become an important factor in the design of interactive software. In the quest to develop usable software, user participation in the design and evaluation process has been advocated. Four methods; logged data, questionnaires, interviews, and verbal protocol analyses have been the prominent base evaluation methods used, sometimes being combined in an attempt to provide a comprehensive evaluation. However, little is known about the strengths and weaknesses of these methods. In this study, these four methods were used to evaluate three different software types (spreadsheet, word processor, and database) with 148 subjects participating. The data obtained enabled a number of conclusions to be drawn regarding the usefulness of the methods when used individually and in combination.     

Lipid composition of the pineal organ from rainbow trout (Oncorhynchus mykiss)

The lipid composition of the pineal organ from the rainbow trout (Oncorhynchus mykiss) was determined to establish whether the involvement of this organ in the control of circadian rhythms is reflected by specific adaptations of lipid composition. Lipid comprised 4.9% of the tissue wet weight and triacylglycerols were the major lipid class present (47% of total lipid). Phosphatidylcholine (PC) was the principal polar lipid, and smaller proportions of other phospholipids and cholesterol were also present. Plasmalogens contributed 11% of the ethanolamine glycerophospholipids (EGP). No cerebrosides were detected. The fatty acid composition of triacylglycerols was generally similar to that of total lipids in which saturated, monounsaturated and polyunsaturated fatty acids (PUFA) were present in almost equal proportions. Each of the polar lipid classes had a specific fatty acid composition. With the exception of phosphatidylinositol (PI), in which 20∶4n−6 comprised 27.4% of the total fatty acids, 22∶6n−3 was the principal PUFA in all lipid classes. The proportion of 20∶5n−3 never exceeded 6.0% of the fatty acids in any lipid class. The predominant molecular species of PC were 16∶0/22∶6n−3 and 16∶0/18∶1, which accounted for 33.2 and 28.5%, respectively, of the total molecular species of this phospholipid. Phosphatidylethanolamine (PE) contained the highest level of di-22∶6n−3 (13.0%) of any phospholipid. There was also 4.9% of this molecular species in phosphatidylserine (PS) and 4.1% in PC. In PE, the species 16∶0/22∶6, 18∶1/22∶6 and 18∶0/22∶6 totalled 45.1%, while in PS 18∶0/22∶6 accounted for 43.9% of the total molecular species. The most abundant molecular species of PI was 18∶0/20∶4n−6 (37.8%). The lipid composition of the pineal organ of trout, and particularly the molecular species composition of PI, is more similar to the composition of the retina than that of the brain. Molecular species are abbreviated as follows: e.g., 16∶0/22∶6 PC is 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine.     

Kinetics of the thermo-oxidative and thermal cracking reactions of Athabasca bitumen

The thermo-oxidative and thermal cracking reactions of Athabasca bitumen were examined qualitatively and quantitatively using differential thermal analysis (DTA). Reaction kinetics of low temperature oxidation (LTO) and high temperature cracking (HTC) were determined. The rate of the LTO reaction was found to be first order with respect to oxygen concentration. The activation energy and the Arrhenius pre-exponential factor were 64 MJ kg^?1 mol^?1 and 10^5.4 s^?1, respectively. The effects of atmosphere, pressure, heating rate and support material on the thermal reactions of bitumen were studied. In general, it was found that partial pressures of oxygen > 10% O₂ favoured exothermic oxidation reactions. High pressure increased the rates of LTO and HTC as well as the exothermicity of these reactions. A major contribution of this study to thermal in-situ processes is that heating rate can be used effectively to control the extent of low temperature oxidation and hence fuel availability during in-situ combustion. Low linear heating rates (2.8 °C min^?1) favoured low temperature oxidative addition and fission reactions. The reaction products readily formed coke and combusted upon heating. High linear heating rates (24.5 °C min ^?1) led to rapid oxidation reactions in the high temperature zone; the high temperature and the energy released during oxidation appeared to promote combustion. Finally, when sand was used as the support material there appeared to be a catalytic effect in both LTO and HTC reactions.     

The enrichment of n−3 polyunsaturated fatty acids using aminopropyl solid phase extraction columns

A rapid, simple and reliable method is described for the preparation of concentrates of methyl or ethyl esters of n−3 polyunsaturated fatty acids by solid phase extraction using aminopropyl bonded silica columns. After applying mixtures of fatty acid esters in hexane, saturated and monounsaturated fatty acid esters are preferentially eluted with hexane whereas polyunsaturated fatty acids (PUFA) can subsequently be eluted with dichloromethane. Concentrates containing 80–90% n−3 PUFA can thus be obtained using fish oil fatty acids esters as a starting material.     

Fusarin C biosynthesis in Fusarium moniliforme and Fusarium venenatum

Fragments of polyketide synthase (PKS) genes were amplified from complementary DNA (cDNA) of the fusarin C producing filamentous fungi Fusarium moniliforme and Fusarium venenatum by using degenerate oligonucleotides designed to select for fungal PKS C-methyltransferase (CMeT) domains. The PCR products, which were highly homologous to fragments of known fungal PKS CMeT domains, were used to probe cDNA and genomic DNA (gDNA) libraries of F. moniliforme and F. venenatum. A 4.0 kb cDNA clone from F. venenatum was isolated and used to prepare a hygromycin-resistance knockout cassette, which was used to produce a fusarin-deficient strain of F. venenatum (kb = 1000 bp). Similarly, a 26 kb genomic fragment, isolated on two overlapping clones from F. moniliforme, encoded a complete iterative Type I PKS fused to an unusual nonribosomal peptide synthase module. Once again, targeted gene disruption produced a fusarin-deficient strain, thereby proving that this synthase is responsible for the first steps of fusarin biosynthesis.     

Diffusion and sorption of nitroplasticizers in vinyl copolymer elastomer and its composites

To study the aging behavior of cured vinyl copolymer elastomer (VCE) under thermal and nitroplasticizer (NP) environment, we investigated the sorption and diffusion of NP in VCE and its composites. The sorption kinetics of NP into VCE and its composites with respect to filler concentration (0–80%) and temperature (18–70°C) were investigated by conventional gravimetric method. The NP sorption process is endothermic. Kinetic studies show that Fickian diffusion can describe the NP sorption in the VCE polymer. The samples with a high filler concentration show more complicated behavior at low temperature than that at high temperature. The present article discusses the dependences of diffusion coefficient and other related parameters on the polymer concentration and morphological structures of the samples. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40729.     

Interactions Between Host-plant Volatiles and the Sex Pheromones of the Bird Cherry-oat Aphid, <Emphasis Type="Italic">Rhopalosiphum padi</Emphasis> and the Damson-hop Aphid, <Emphasis Type="Italic">Phorodon humuli</Emphasis>

The bird cherry-oat aphid, Rhopalosiphum padi (L.), and the damson-hop aphid, Phorodon humuli (Schrank), migrate at the same time of year and colonize closely related Prunus spp. as primary hosts, but utilize (1R,4aS,7S,7aR)-nepetalactol and (1RS,4aR,7S,7aS)-nepetalactol, respectively, as sex pheromones. Interactions between these sex pheromones and benzaldehyde and methyl salicylate, plant volatiles common to primary hosts of both species, were investigated to assess whether they confer reproductive isolation between these species. Female autumn migrants (gynoparae) and males of these two species were caught in the field with water traps baited with their respective sex pheromones. Rhopalosiphum padi gynoparae and males also responded positively to benzaldehyde. Release of either benzaldehyde or methyl salicylate with the conspecific sex pheromone increased catches of both species of aphid. However, releasing both plant volatiles with the sex pheromone of R. padi increased catches of gynoparae and males, but reduced those with the sex pheromone of P. humuli. These results support the hypothesis that specific plant volatiles synergize responses of autumn migrating aphids to their sex pheromone. Because these interactions are species-specific, they may be important in allowing males to discriminate between conspecific sexual females (oviparae) and those of other aphid species.     

Desulphurization of Athabasca petroleum coke by (a) chemical oxidation and (b) solvent extraction

This study concerns the desulphurization of petroleum coke produced by delayed coking of Athabasca bitumen. The coke contains 7.5 wt % sulphur, 99.6% of the sulphur in coke being organic and the remainder pyritic. The coke was treated both with nitric acid and by solvent extraction. During nitric acid treatment, sulphur removal was found to increase with reaction time and the concentration of nitric acid, and to decrease slightly with increase in particle size. About 30% of organic sulphur was removed from ?250 Tyler mesh coke particles by 6 N nitric acid for 4 h at 102 °C. The basic mechanism for this treatment is oxidation and solution of organic sulphur compounds by nitric acid. About 50% ash was also removed from the coke. For solvent extraction, o-chlorophenol was used. Sulphur removal was found to increase with extracting temperature and time, and to decrease with increase in particle size of coke. About 19% of the sulphur was removed from ?250 mesh coke particles by o-chlorophenol at 160 °C in 2 h. When treated consecutively with nitric acid and o-chlorophenol, about 40% of sulphur was removed from the ?250 mesh coke particles.     

Application de l'analyse des correspondances a des resultats d'essais de traitement d'eaux de surface

Many results show that if a conventional coagulation-flocculation-clarification treatment line is combined with pre-ozonation, removal efficiency as regards pariculate and dissolved organics is substantially enhanced. However, research on the optimum balance between pre-ozonation and coagulation treatment has turned out to be difficult because of the numerous parameters that are involved. In order to identify the most significant among clarification criteria it was in fact necessary to develop a more elaborate model than is required for conventional statistical analysis, capable of comparing all the intervening factors. This we finally achieved by a program based on stepwise regression analysis.Measuring samples and parametersSamples. Samples were taken from the pilot plant located at Choisy-le-Roi on premises belonging to the Paris Suburbs Water Authority, over a period of 3 months from 1 April to 24 June, i.e. exactly 43 days of research.The plant shown in Fig. 1 consists of 4 trains working in parallel arrangement. This layout allows practically two complete treatment runs daily so that 8 different ozone-coagulations could be tested each day on the same quality of raw water. 387 samples were thus taken with 344 treated waters and 43 raw waters. The campaign was designed over this rather long period to achieve two ends:

1. (1) to gather enough results to give real significance to the mathematical computation. During the 43 day experimental campaign, each ozone-WAC combination was repeated more than 10 times;

2. (2) to find a means of allowing for fluctuation in the river in relation to phenomena of great amplitude such as rises in temperature and changes in flow rate, so that acquired results could eventually be extrapolated for application to industrial treatment plant management.

Parameters. Twenty-two parameters were measured in respect of each sample of raw and treated water. The aim of the research being to define the main parameters on which to base the combination, it was essential to begin with a study of all the magnitudes normally representative of suface waters.These parameters can be divided into various types:

treatment parameters: WAC + O₃; the concentration tested are shown in mg l⁻¹ in Table 2 and Fig. 2;

parameters concerning suspended solids: total number of particles per ml (NT) and their equivalent diameter (D), turbidity (Tu) expressed in drops of mastics and zeta potential (Z_p);

parameters concerning organics: total organic carbon (COT) in mg l⁻¹ of C, KMnO₄ in mg l⁻¹ of O₂, dissolved O₂ in mg l⁻¹, u.v. absorption at 254 nm, NTK and ammonia (NH₄⁺), both in mg l⁻¹.

Besides pH and temperature which vary very little in Siene river water, total aluminium (ALT) in mg l⁻¹ and residual ozone (RO₃) were monitored.Analysis of data. The basic data represented in the following matrix (I × J), in which I is the sum of the sampling steps and J the sum of the concentrations of the different chemical elements, are too vast for conventional statistical analysis. By factor analysis, one can obtain as a final result a geometrical figure in a two-dimensional space but that simultaneously accounts for all the combinations of I and J. We thus obtain a factorial chart analysing the proximity between variables in terms of correlation and that between individual points in terms of similarity of behaviour toward these variables as a whole.Each component i of I and j of J is represented in profile form ƒ_jⁱ (or ƒ_I^j)=k(i,j)/k(i) as shown in the matrix below:

Full-size image (1K)

All of the profiles and I and J, each with a volume allocated pro rata the complete line (or column), make up a set of points with a corresponding volume in a multi-dimensional space. In the case under study, each components i (sampling steps) are in a space with 22 dimensions and each variable j (concentrations) in a 387-dimensional space. The purpose of the analysis is to obtain from the cloud as true a representation as possible brought down to a 2-dimensional space. This dimensional reduction consists in finding a sub-space in which the space between individual points i or j are as close as posible to the initial distances in IR₂₂ (or IR₃₈₇). The distance used in factor analysis is the distribution distance expressed as: . The plane thus located is defined by 2 perpendicular straight lines. They are the factorial or inertia axes. Inertia measures the total dispersal area of the cloud on one axis and shows the ratio between the points projected in space and the sum of the square-roots of the distances between the initial points. It measures the dispersion of data on the axis. The axes are called “factors”.Using this method, it becomes possible to described the accumulated data and quantify the phenomena that control both the variable parameters and their components (I or J) without any preconceived hypothesis as to the relative importance of the initial data. And, furthermore, we have a simultaneous geometric representation of samples and variables.Results. The first (horizontal) axis, F₁ represent the abatement of suspended particles and organics. The second (vertical) axis enables the different treatment trains to be interpreted in terms of ozone and residual ozone. Four distinct groups appear on plane F₁ × F₂:

Group 1: Group 1 represents water with no WAC or ozone treatment nor residual ozone. Characteristics include a very high suspended particles content and a certain amount of organics (i.e. variables N, D₁, D₂…D₁₀ and KMnO₄). This group is representative of raw waters in general.

The variable KMnO₄ factor quite realistically reflects the clarification treatment, a high KMnO₄ value indicating the presence of raw water, a low content the presence of treated water.

Group 2: This is an intermediate group between raw water and the water in trains A and B. It is characterized by poor abatement of both suspended solids and organics and corresponds to the majority of waters in train D with no pre-ozonation and train A with low-rate ozonation (0.3 mg l⁻¹).

Group 3: A high WAC rate and an average ozone rate are the predominant features of this group in which residual ozone is very low. A good level of suspended solids and organic removal was obtained, as is the case of treatments in general, and as practically demonstrated by trains A and B.

Group 4: This group corresponds to the treated water with a high ozone injection rate, hence a high residual ozone content. A good level of suspended solids and organics removal is obviously obtained, most of the water having been treated on train C. This maximum ozone residual for a similar abatement of organics concentration indicates that the extra ozone added was in excess of the amount required in order to oxidize the quantity of organics in the effluent. The optimum ozone dose must therefore be somewhere near that of the previous group, i.e. trains A and B.

In conclusion, analysis by stepwise regression identified the five main variables that define the complete clarification process: N_T, KMnO₄, TOC, WAC and ozone. As regards the last two mentioned, differentiation between groups 3 and 4 provides a means of determining the optimum dose rate for ozone in the treatment concerned, i.e. less than for train C (group 3) where the residual ozone rate is higher, hence approximately the same as for trains A and B—in the region 0.3–0.8 mg l⁻¹.     

Functional conservation of cytosolic proteins required for endosomal vesicle fusion

Recent studies suggest that intracellular membrane traffic relies upon families of related proteins which confer specificity to individual transport reactions but which operate in tandem with a ubiquitous fusogenic complex containing the N-ethylmaleimide-sensitive fusion protein (NSF). The extent to which components of this process are functionally conserved is apparent from the finding that yeast Sec18 protein (Sec18p) can substitute for mammalian NSF in intra-Golgi transport reactions. Here we report that yeast cytosol can support mammalian endosomal vesicle fusion, demonstrating conservation of cytosolic components required for this reaction. Furthermore, under conditions in which the fusion reaction is NSF-dependent we show that yeast Sec18p can functionally substitute for NSF, showing that the yeast protein is capable of catalysing at least two distinct mammalian membrane fusion events. In addition we exploit the complex pattern of sensitivity of the mammalian reaction to N-ethylmaleimide (NEM), coupled with the use of yeast cytosol, to dissect a number of factors required for fusion. We reveal at least three novel NEM-sensitive activities. One of these can be restored by yeast cytosol suggesting that it is functionally conserved.