Relationship between time-to-detection (TTD) and the biological parameters of Pichia anomala IG02; modelling of TTD as a function of temperature, NaCl concentration, and pH and quantification of their effects

The time to detection (TTD) for Pichia anomala IG02 was defined, for inoculum sizes lower than 6 log(10)cfu/ml, as the time elapsed from inoculation to the moment at which an OD of 0.12 was reached. In other cases, TTD can be estimated by interpolation within the time elapsed from the previous readings below OD=0.12 and the next above it. A linear relationship, which depended on the inoculum size, between lnTTD with ln lambda and ln mu(m) was found. These relationships can be used to estimate the biological parameters of cultures with low inoculum levels. In addition, TTD for P. anomala IG02 could be modelled as a function of environmental conditions. The model can also be applied to lambda and mu(m) through their relationships with TTD. The effects of temperature, NaCl content and pH were quantified by the generalized z-values. An increase of 5.97 in NaCl concentration, a decrease of 1.97 units of pH, or a decrease of 6.08 degrees C doubled the TTD or caused a 2.53-fold increase in lambda and a 2.56-fold decrease in the mu(m).     

Existence and determination of competitive equilibrium in unitcommitment power pool auctions: price setting and schedulingalternatives

The existence, determination and effects of competitive market equilibrium for unit commitment power pool auctions are investigated in this paper. When an equilibrium does not exist, under specific situations, conflictive multiple optimal primal solutions may exist. When an equilibrium exists, multiple primal solutions do not represent conflicts of interest. The existence or nonexistence of competitive equilibrium can be determined if the dual problem is solved to optimality. If equilibrium does not exist, there is excess supply at the optimal dual solution, which can be used to define priority orders and price setting alternatives to determine a final schedule, and avoid the conflicts of interest and revenue deficiency. Under disequilibrium, the optimal dual variables are not market clearing prices; a nonuniform pricing rule that avoids the flaws and complications of other pricing rules, such as maximum average cost and price minimization auctions, is proposed in the paper. The proposed scheduling and price-setting alternatives show that unit commitment models can be used in a market environment     

Synchronisation and chaos in a laser diode driven by a resonant tunnelling diode

The authors report on a hybrid integration of a resonant tunnelling diode laser diode driver configuration that can operate as a self-oscillating circuit, and when externally perturbed shows regions of frequency division and frequency multiplication, quasi-periodic and chaotic oscillations, both in the optical and electrical outputs. The authors also demonstrate that this optoelectronic circuit is well described as a Lienard?s oscillator. The synchronisation capabilities of the circuit have potentially novel functions for optical communications systems including clock recovery, clock division and data encryption.     

Long-Term Treatment with Citicoline Prevents Cognitive Decline and Predicts a Better Quality of Life after a First Ischemic Stroke

Stroke, as the leading cause of physical disability and cognitive impairment, has a very significant impact on patients’ quality of life (QoL). The objective of this study is to know the effect of citicoline treatment in Qol and cognitive performance in the long-term in patients with a first ischemic stroke. This is an open-label, randomized, parallel study of citicoline vs. usual treatment. All subjects were selected 6 weeks after suffering a first ischemic stroke and randomized into parallel arms. Neuropsychological evaluation was performed at 1 month, 6 months, 1 year and 2 years after stroke, and QoL was measured using the EuroQoL-5D questionnaire at 2 years. 163 patients were followed during 2 years. The mean age was 67.5 years-old, and 50.9% were women. Age and absence of citicoline treatment were independent predictors of both utility and poor quality of life. Patients with cognitive impairment had a poorer QoL at 2 years (0.55 vs. 0.66 in utility, p = 0.015). Citicoline treatment improved significantly cognitive status during follow-up (p = 0.005). In conclusion, treatment with long-term citicoline is associated with a better QoL and improves cognitive status 2 years after a first ischemic stroke.     

A Spanish Inter-laboratory Comparison on the Characterization of Sterilization Autoclaves

Sterilization autoclaves are devices used to sterilize equipment and supplies; their users require a periodic determination of their performance to ensure that the required temperature is reached and maintained for the predefined time interval. Within the ENAC (Entidad Nacional de Acreditación, Spanish national accreditation body) Temperature and Humidity Technical Subcommittee, it was decided to carry out an inter-laboratory comparison on the characterization of sterilization autoclaves aiming to demonstrate the equivalence among the test procedures of the different participants. This paper presents the data processing and the results of this comparison that showed some discrepancies in the stability and uniformity measurements due to different parameter definitions and a probable underestimation of some uncertainty sources. The results show good agreement among the participants in the estimation of the set-point correction, while the estimation of the device stability and uniformity was not compatible in some cases. The use of wired or wireless sensors did not bias the results, but the laboratories that used pt-100 obtained results that underestimated the value of the thermal stability, probably due to their higher thermal mass and response time.     

Analysis of frequency divider RTD circuits

The behavior of a novel circuit topology able to implement a frequency divider is studied. This circuit is composed of a resonant tunnelling diode (RTD), an inductor, and a capacitor, so it exhibits a very high operating frequency and low power consumption. It employs the period-adding sequences which appear in its bifurcation diagram to perform the frequency division. Compared to a previously reported similar circuit, it has wider operation windows and a higher division factor for the driver frequency, while maintaining the extremely high operating frequency, its simplicity, and the division factor tunability through the selection of circuit parameters. Simulation results using the HSPICE RTD model from project LOCOM as well as several realistic parasitics elements are given, which confirm the theoretical capabilities previously analyzed.     

Establishment of conditions for green table olive fermentation at low temperature

Four Lactobacillus plantarum strains were isolated from table olive cold fermentation brines. Their specific growth rate and acidification in MRS broth and in green table olive brines were studied by means of a mixed 2 pH (4.5 and 5.0) x 3 salt (3, 4 and 5%, w/v, NaCl) x 3 incubation temperature (9, 12 and 15 degrees C) levels factorial design. In MRS broth, the greatest effect (linear) on acidification was due to temperature. In brine, the effects were considerably less, pH (linear) being the most important for specific growth rate, and temperature (linear) for acidification. In both media, an initial pH of 5.0 led to good acidification at 12-15 degrees C. The effectiveness of the conditions found (initial pH of 5.0; 3%,w/v, NaCl; and incubation at 12 degrees C) was confirmed in simulated green olive fermentations with three of the strains, which proved especially robust. Behaviour in terms of growth and acidification rates was similar for these strains, and comparable to that observed in traditional processes, although mannitol and sucrose were not metabolised and fructose was only partially used. This leads to the possibility of obtaining normal fermentation processes of table olives in cold regions when appropriate initial conditions and starter cultures are used.     

Tunable Magnetism in Nanoporous CuNi Alloys by Reversible Voltage‐Driven Element‐Selective Redox Processes

Voltage‐driven manipulation of magnetism in electrodeposited 200 nm thick nanoporous single‐phase solid solution Cu₂₀Ni₈₀ (at%) alloy films (with sub 10 nm pore size) is accomplished by controlled reduction‐oxidation (i.e., redox) processes in a protic solvent, namely 1 m NaOH aqueous solution. Owing to the selectivity of the electrochemical processes, the oxidation of the CuNi film mainly occurs on the Cu counterpart of the solid solution, resulting in a Ni‐enriched alloy. As a consequence, the magnetic moment at saturation significantly increases (up to 33% enhancement with respect to the as‐prepared sample), while only slight changes in coercivity are observed. Conversely, the reduction process brings Cu back to its metallic state and, remarkably, it becomes alloyed to Ni again. The reported phenomenon is fully reversible, thus allowing for the precise adjustment of the magnetic properties of this system through the sign and amplitude of the applied voltage.     

A genetic-based neuro-fuzzy approach for modeling and control ofdynamical systems

Linguistic modeling of complex irregular systems constitutes the heart of many control and decision making systems, and fuzzy logic represents one of the most effective algorithms to build such linguistic models. In this paper, a linguistic (qualitative) modeling approach is proposed. The approach combines the merits of the fuzzy logic theory, neural networks, and genetic algorithms (GAs). The proposed model is presented in a fuzzy-neural network (FNN) form which can handle both quantitative (numerical) and qualitative (linguistic) knowledge. The learning algorithm of a FNN is composed of three phases. The first phase is used to find the initial membership functions of the fuzzy model. In the second phase, a new algorithm is developed and used to extract the linguistic-fuzzy rules. In the third phase, a multiresolutional dynamic genetic algorithm (MRD-GA) is proposed and used for optimized tuning of membership functions of the proposed model. Two well-known benchmarks are used to evaluate the performance of the proposed modeling approach, and compare it with other modeling approaches.