Selecting control factor values in a robust design using a scatter plot

When the results of an experimental design are analyzed, in which control factors and noise factors are involved, it may be difficult to determine the combination of values of the control factors that produce the best behavior of the response, addressing both its level (or distance from the target value) and its variability. This article presents an analysis proposal that is based on the model obtained for the response and uses, as its central element, a scatter plot of its expected value vs its standard deviation. In this plot, each point corresponds to a combination of values of the control factors; thus, it is easy to identify the points with better response behavior. In our opinion, this graph provides significant advantages over the other methods that have been proposed; among them is the fact that it is always a scatter plot, regardless of the number of factors that end up being active, and that it is easy to understand and use, especially with the possibilities offered by the current statistical software packages. Copyright © 2010 John Wiley & Sons, Ltd.     

Urban sprawl in the Mediterranean?: Patterns of growth and change in the Barcelona Metropolitan Region 1993–2000

Debates on the urban form have become strongly polarized between the advocates and opponents of the compact and of the dispersed or “sprawled” city. In this paper we argue that this may be the result of an excessive concentration on the study of the American experience and the neglect of other urban contexts, and examine the recent process of urban growth against the background of urban compactness and extreme densification represented by the Barcelona Metropolitan Region (BMR). The comparison of two detailed land-cover maps of 1993 and 2000 shows a progressive transformation in the traditional urban character of the region. Lower urban densities, high losses of non-urban land covers, depopulation of the metropolitan inner core, an increasing importance of single housing or the expansion of transportation infrastructures confirm the generalization of the dispersed urban model. However, the presence of numerous medium sized towns has also proved to be a deterrent of excessive dispersion. In conclusion, polycentric metropolitan areas such as the BMR may be more adjusted to absorb the negative effects of dispersion than monocentric areas.     

Proteomic profile of dry-cured ham relative to PRKAG3 or CAST genotype, level of salt and pastiness

Two-dimensional electrophoresis was used to compare dry-cured biceps femoris insoluble protein fraction according to genotype (PRKAG3Ile199Val and CASTLys249Arg/Ser638Arg) as well as salt and pastiness level. The PRKAG3 affected mainly muscle metabolic enzymes, indicating its possible influence on muscle metabolism with heterozygotes Ile/Val appearing different from both homozygous genotypes. The effect of CAST was smaller, affecting the quantity of one actin fragment. Dry-cured ham salt and pastiness level affected a wide variety of protein spots including metabolic enzymes, plasma proteins, chaperones and myofibrillar proteins, including protein fragments, indicating the connection with proteolysis. Pastiness was associated with salt content, reflected also by the fact that many spots were affected by both factors. Despite the absence of extreme pastiness (or low salt samples), some protein spots (actin, MHC fragment, desmin fragment) exhibited important differences in intensity according to pastiness (and salt level) suggesting they could be used as potential quality markers.     

Resource management implications and strategies for SDR clouds

This paper analyzes the computing resource management implications of SDR base stations implemented as SDR clouds. SDR clouds describe distributed antennas that connect to a data center for digital signal processing. The data center employs cloud computing technology, providing a virtualized computing resource pool. The service area of a single SDR cloud may be a metropolitan area with a high user density. Hence, the data center will execute thousands of SDR applications in parallel, providing wireless communications services to several radio cells. Whenever a user initiates or terminates a wireless communications session, computing resources need to be allocated or deallocated in real time. We therefore propose a hierarchical resource management. This paper justifies such an approach and analyzes different resource management strategies. The results indicate the need for strategies that can dynamically adapt to the given user traffic distribution.     

Effect of pH(24), NaCl content and proteolysis index on the relationship between water content and texture parameters in biceps femoris and semimembranosus muscles in dry-cured ham

The aim of the present study was to determine the effect of pH level and NaCl content on the relationship between water content and texture parameters in semimembranosus and biceps femoris muscles in dry-cured ham. The experiment was undertaken using 18 hams, selected in a commercial slaughterhouse. Half of the hams had a pH<5.7 and the rest a pH>6.2, measured in the semimembranosus muscle at 24-h post mortem (pH(SM24)). The hams were treated with 20, 50 or 80g of NaCl per kg of ham. At the end of the aging process nine samples from semimembranosus and biceps femoris muscles were dried to different levels of water content covering the range from 22.4% to 58.5%. At the end of the drying period, a Texture Profile Analysis was used to determine textural parameters. Samples from biceps femoris muscle and samples from hams with low pH(SM24) showed a higher proteolysis index (100×non-protein nitrogen/total nitrogen) than samples from semimembranosus muscle and samples from hams with high pH(SM24), respectively. The proteolysis index decreased when the added NaCl amount increased. The proteolysis index was the parameter that best explained the modifications in the relationship between water content and the texture parameters (hardness, cohesiveness and springiness) of dry-cured ham muscles and it would be considered in order to predict the texture in dry-cured ham at different drying levels. Dry-cured hams with a lower proteolysis index were more prone to present harder texture at low water contents, which is typical of hams with crustiness problems.     

Consumer attitude towards sodium reduction in meat products and acceptability of fermented sausages with reduced sodium content

Lowering salt content in meat products is possible from a technological and sensorial point of view, although little information is available about the consumers' attitude and acceptance of these products. Attitude towards low salt meat products, following the Theory of Planned Behaviour (TPB) proposed by Ajzen, was evaluated by 392 consumers. Acceptability of small calibre fermented sausages with 50% molar substitution of NaCl by six different mixtures of KCl (0-50%) and K-lactate (0-50%) and the control (22g NaCl/kg) was determined by 98 consumers. The preference of the previous best two treatments was compared to the batch control by 279 consumers. In general consumers had a positive attitude towards low salt meat products, being higher for women than for men. Women showed stronger ideas and higher Perceived Control on the Behaviour towards reduced sodium meat products than men. Smokers showed lower intense beliefs than non-smokers. Consumers with a basic level of education were more affected by what other people important for them thought they should do. The final model obtained using the Theory of Planned Behaviour showed a good predictive capacity (R(2)=0.60) and a good internal consistency. Regarding the acceptability study, batches with substitution levels of 50% and 40% by K-lactate, showed lower overall acceptance than the control batch. Significant differences in acceptability were found regarding the gender and place of residence of the consumers. The preference study showed no differences between the batch control and batches with 50% KCl and 40% KCl + 10% of K-lactate substitution levels. According to these results and from a sensorial point of view, it is possible to reduce NaCl content in small calibre fermented sausages by 50% and obtain a product acceptable for consumers.     

A contribution to solve the problem of coating properties extraction in quartz crystal microbalance applications

The problem of coating properties extraction in quartz crystal resonator (QCR) applications is one of the challenging tasks of QCR applications, not completely solved even in theoretical conditions. The present work demonstrates that the problem is determined only for a set of three parameters of the coating, which concentrate the four coating properties. The following parameters are chosen: the surface mass density m8 = p1h1, the loss tangent tan delta1 = G'1/G'1, and the magnitude of the characteristic impedance /Z1(c)/ = (p1/G1/)(1/2). An algorithm is proposed that permits, in ideal conditions, an unambiguous extraction of these parameters, starting only from the admittance spectrum of a three-layer compound resonator, obtained from the one-dimensional transmission-line model (TLM) around the resonance. The algorithm introduces three additional improvements in relation to other routines: the calculation time is drastically reduced, the problem of erroneous solutions related to relative minima in typical fitting routines is eliminated, and a systematic error analysis in the extraction of the coating properties in real practice can be carried out. The use of the proposed algorithm as a tool for studying the effects of different phenomena such as slipping or surface roughness is introduced.     

Lipoprotein Profile in Immunological Non-Responders PLHIV after Antiretroviral Therapy Initiation

Nuclear magnetic resonance (NMR)-based advanced lipoprotein tests have demonstrated that LDL and HDL particle numbers (LDL-P and HDL-P) are more powerful cardiovascular (CV) risk biomarkers than conventional cholesterol markers. Of interest, in people living with HIV (PLHIV), predictors of preclinical atherosclerosis and vascular dysfunction may be associated with impaired immune function. We previously stated that immunological non-responders (INR) were at higher CV risk than immunological responders (IR) before starting antiretroviral therapy (ART). Using Liposcale^® tests, we characterized the lipoprotein profile from the same cohort of PLHIV at month 12 and month 36 after starting ART, intending to explore what happened with these indicators of CV risk during viral suppression. ART initiation dissipates the differences in lipoprotein-based CV risk markers between INR and IR, and only an increase in the number of HDL-P was found in INR + IR when compared to controls (p = 0.047). Interestingly, CD4⁺ T-cell counts negatively correlated with medium HDL-P concentrations at month 12 in all individuals (ρ = −0.335, p = 0.003). Longitudinal analyses showed an important increase in LDL-P and HDL-P at month 36 when compared to baseline values in both IR and INR. A proper balance between a proatherogenic and atherogenic environment may be related to the reconstitution of CD4⁺ T-cell count in PLHIV.     

Dual Costimulatory and Coinhibitory Targeting with a Hybrid Fusion Protein as an Immunomodulatory Therapy in Lupus Nephritis Mice Models

Systemic lupus erythematosus is a complex autoimmune disorder mostly mediated by B-cells in which costimulatory signals are involved. This immune dysregulation can cause tissue damage and inflammation of the kidney, resulting in lupus nephritis and chronic renal failure. Given the previous experience reported with CTLA4-Ig as well as recent understanding of the PD-1 pathway in this setting, our group was encouraged to evaluate, in the NZBWF1 model, a human fusion recombinant protein (Hybri) with two domains: CTLA4, blocking the CD28—CD80 costimulatory pathway, and PD-L2, exacerbating the PD-1–PD-L2 coinhibitory pathway. After achieving good results in this model, we decided to validate the therapeutic effect of Hybri in the more severe MRL/lpr model of lupus nephritis. The intraperitoneal administration of Hybri prevented the progression of proteinuria and anti-dsDNA antibodies to levels like those of cyclophosphamide and reduced the histological score, infiltration of B-cells, T-cells, and macrophages and immune deposition in both lupus-prone models. Additionally, Hybri treatment produced changes in both inflammatory-related circulating cytokines and kidney gene expression. To summarize, both in vivo studies revealed that the Hybri effect on costimulatory-coinhibitory pathways may effectively mitigate lupus nephritis, with potential for use as a maintenance therapy.     

Single-Crystal Nanowire Cesium Tin Triiodide Perovskite Solar Cell

This work reports for the first time a highly efficient single-crystal cesium tin triiodide (CsSnI₃) perovskite nanowire solar cell. With a perfect lattice structure, low carrier trap density (≈5 × 10¹⁰ cm⁻³), long carrier lifetime (46.7 ns), and excellent carrier mobility (>600 cm² V⁻¹ s⁻¹), single-crystal CsSnI₃ perovskite nanowires enable a very attractive feature for flexible perovskite photovoltaics to power active micro-scale electronic devices. Using CsSnI₃ single-crystal nanowire in conjunction with highly conductive wide bandgap semiconductors as front-surface-field layers, an unprecedented efficiency of 11.7% under AM 1.5G illumination is achieved. This work demonstrates the feasibility of all-inorganic tin-based perovskite solar cells via crystallinity and device-structure improvement for the high-performance, and thus paves the way for the energy supply to flexible wearable devices in the future.