Designing with scenarios: A critical review of current research and practice

There is a great deal of requirements engineering specifically, and information systems development research in general, in the area of scenarios as the ‘vocabulary’ for discussing and characterising designs for new artefacts. This is partly due to opening up the design process to a variety of participants in a project, and making explicit their ways of working, thinking and interactions with the design products. Scenarios, being concrete, and easy to understand and use, provide the means to describe the design vocabulary. They are used to focus on episodic cases, exchange ideas and thoughts about them effectively, and generally describe requirements and designs for a new artefact from the user’s perspective. In this paper, we review the effectiveness of the current state-of-practice in scenario-based approaches. The objective of this evaluation exercise is to define the requirements for improved ‘by scenario’ approaches to cope with requirements and designs for developing new artefacts.     

Quality control and storage studies of virgin olive oil: Exploiting UV spectrophotometry potential

The present work was undertaken in order to examine whether K₂₃₂ values and other UV absorbance characteristics could replace the determination of peroxide value (PV) in routine quality control and also in storage studies of virgin olive oil (VOO). For this reason, PV and extinction coefficients were determined for a large number of VOO samples (n = 40). The samples were then stored at 45 °C for several weeks. Changes in the lipid matrices were monitored by periodic measurements of the same quality indices. UV absorption spectra and the respective derivative ones were obtained before and during storage. Regression data showed that the PV is correlated with the K₂₃₂ value not only at time zero but also during storage. Evidence derived from the first derivative spectrum is strongly related to the oxidative status of the oil. The findings may be used (a) to simplify the decision tree suggested for “the verification of consistency of a VOO sample with commercial category declared” in the EEC Regulation N^o 1989 (2003), which takes into account acidity measurement, PV and absorbance values (K₂₇₀, ΔK, K₂₃₂), and (b) to collect qualitative and quantitative information about the oxidation process during storage.     

The influence of carrying a backpack on college student pedestrian safety

University students walk frequently, and individuals ages 18-22 have among the highest rates of pedestrian injury among any age group in the United States. These injuries are caused by a wide range of individual, interpersonal, and environmental factors, but one factor that has not been previously considered carefully is the influence of wearing a heavy backpack on pedestrian safety. Backpacks are known to slow walking speed and disrupt perception of one's environment, so it is reasonable to question whether they might also influence safe pedestrian behavior. Ninety-six college students engaged in 20 street-crossings within a virtual pedestrian environment. Half the crossings were completed while bearing a backpack weighing 12% of their body weight; the other half were completed without any burdens. Results suggest that participants walked more slowly, left less safe time to spare after crossing the virtual street, and experienced more frequent hits or close calls with traffic when crossing while carrying the backpack. They also missed fewer safe opportunities to cross while carrying the backpack. Our tests of several demographic characteristics, pedestrian behaviors, and backpack use, as covariates suggest the finding holds across all subsamples included in our study. Implications for pedestrian safety and future research are discussed.     

Aberrant PLN-R14del Protein Interactions Intensify SERCA2a Inhibition,Driving Impaired Ca2+ Handling and Arrhythmogenesis

Phospholamban (PLN), a key modulator of Ca²⁺-homeostasis, inhibits sarcoplasmic reticulum (SR) calcium-ATPase (SERCA2a) and regulates cardiac contractility. The human PLN mutation R14del has been identified in arrhythmogenic cardiomyopathy patients worldwide and is currently extensively investigated. In search of the molecular mechanisms mediating the pathological phenotype, we examined PLN-R14del associations to known PLN-interacting partners. We determined that PLN-R14del interactions to key Ca²⁺-handling proteins SERCA2a and HS-1-associated protein X-1 (HAX-1) were enhanced, indicating the super-inhibition of SERCA2a’s Ca²⁺-affinity. Additionally, histidine-rich calcium binding protein (HRC) binding to SERCA2a was increased, suggesting the inhibition of SERCA2a maximal velocity. As phosphorylation relieves the inhibitory effect of PLN on SERCA2a activity, we examined the impact of phosphorylation on the PLN-R14del/SERCA2a interaction. Contrary to PLN-WT, phosphorylation did not affect PLN-R14del binding to SERCA2a, due to a lack of Ser-16 phosphorylation in PLN-R14del. No changes were observed in the subcellular distribution of PLN-R14del or its co-localization to SERCA2a. However, in silico predictions suggest structural perturbations in PLN-R14del that could impact its binding and function. Our findings reveal for the first time that by increased binding to SERCA2a and HAX-1, PLN-R14del acts as an enhanced inhibitor of SERCA2a, causing a cascade of molecular events contributing to impaired Ca²⁺-homeostasis and arrhythmogenesis. Relieving SERCA2a super-inhibition could offer a promising therapeutic approach for PLN-R14del patients.     

Volatile organic compounds of mountainous plant species and the produced milk as affected by altitude in Greece: A preliminary study

The objective of this study was to characterise the volatile organic compounds (VOCs) profile of plant species, bulk forage grazed by sheep and produced milk at different mountainous areas of Greece. The most abundant plant species of vegetation at 800 m (hill‐land) and 1300 m (highland) altitude, bulk forage and milk samples, were collected. The VOCs profiles of the plant species and milk varied. Common VOCs in milk from both areas were identified, whereas others were discriminatory for each area. Overall, the VOCs composition of mountainous milk could provide a basis for Feta cheese identification with its region.     

N-Acetylcysteine Administration Attenuates Sensorimotor Impairments Following Neonatal Hypoxic-Ischemic Brain Injury in Rats

Hypoxic ischemic (HI) brain injury that occurs during neonatal period has been correlated with severe neuronal damage, behavioral deficits and infant mortality. Previous evidence indicates that N-acetylcysteine (NAC), a compound with antioxidant action, exerts a potential neuroprotective effect in various neurological disorders including injury induced by brain ischemia. The aim of the present study was to investigate the role of NAC as a potential therapeutic agent in a rat model of neonatal HI brain injury and explore its long-term behavioral effects. To this end, NAC (50 mg/kg/dose, i.p.) was administered prior to and instantly after HI, in order to evaluate hippocampal and cerebral cortex damage as well as long-term functional outcome. Immunohistochemistry was used to detect inducible nitric oxide synthase (iNOS) expression. The results revealed that NAC significantly alleviated sensorimotor deficits and this effect was maintained up to adulthood. These improvements in functional outcome were associated with a significant decrease in the severity of brain damage. Moreover, NAC decreased the short-term expression of iNOS, a finding implying that iNOS activity may be suppressed and that through this action NAC may exert its therapeutic action against neonatal HI brain injury.     

Arousing a wide range of emotions within educational virtual reality simulation about major depressive disorder affects knowledge retention

Virtual Reality - The experience of using an educational application, concerning a major depressive disorder simulation, could be anything but pleasant, so the challenges of creating such an...     

Comparison between laser‐induced nucleation of ZnS and CdS nanocrystals directly into polymer matrices

The nucleation of two kinds of crystalline nanoparticles, zinc sulfide (ZnS), and cadmium sulfide (CdS), is achieved directly into specific sites of polymer matrices after their irradiation with UV laser pulses. The starting samples consist of polymers doped with precursors of Zn or Cd thiolate that are proved to decompose after the absorption of UV light, resulting into the nanoparticles formation. The growth of the crystalline nanostructures is followed throughout the irradiation of the samples with successive incident pulses, by different methods, such as transmission electron microscopy, atomic force microscopy, confocal microscopy, and X‐ray diffraction. Special attention is paid to the difference of the formation pathways of the two kinds of nanoparticles studied, because the Cd thiolate precursor exhibits much higher absorption efficiency than the Zn thiolate one, at the applied UV wavelength. Indeed, CdS nanoparticles become evident after the very first incident UV pulses, whereas the formation of ZnS nanocrystals requires rather prolonged irradiation, always through a macroscopically nondestructive procedure for the polymer matrix. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

Localized formation and size tuning of CdS nanocrystals upon irradiation of metal precursors embedded in polymer matrices

We present a method of spatial and dimensional controlled formation of CdS quantum dots into polymer matrices by light irradiation. The initial samples consist of Cd thiolate precursors doped in TOPAS polymer matrix. Under pulsed UV laser irradiation the precursors are photolysed driving to the nucleation of CdS nanocrystals, with increasing size and concentration, related to the number of UV pulses. The formed quantum dots are localized in the irradiated area, while the host polymer remains macroscopically unaffected by the UV irradiation. In this study we investigate how the formation of the nanocrystals (size, dimensions, and concentration) is affected by the use of different irradiation conditions (wavelength, number of pulses), revealing information about the different pathways followed during the formation. The change of the size of the dots results in the change of the peak of their emission due to the quantum size effect, which is studied by fluorescence measurements. The results are reinforced by TEM microscopy and by XRD measurements. The main advantages of the presented method are the size tuning of the produced dots and their spatial confinement inside the host matrix, not possible by the other methods used until now (thermal annealing, mixing etc.).     

The Effects of Fatigue on the Atomic Structure with Cyclic Loading in Zr50Cu40Al10 and Zr60Cu30Al10 Glasses

The potential damage effect from fatigue on Zr bulk metallic glass alloys of Zr₅₀Cu₄₀Al₁₀ at the eutectic point and Zr₆₀Cu₃₀Al₁₀ away from the eutectic point (in atomic percent) is examined via the local atomic structure, which was obtained from the pair density function analysis of the synchrotron X-ray radiation and neutron data. Samples cut from the same rods were subjected to 10⁴, 10⁵, and 10⁶ compression cycles ex situ, and the evidence for fatigue damage was investigated by comparing alloys before and after cyclic loading. Bond orientation was observed particularly in Zr₅₀Cu₄₀Al₁₀, suggesting that fatigue damage occurs even in the elastic range, below the yield point, and during cyclic loading. The initiation of fatigue changes is observed first within small localized atomic regions.