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The potential effect of preharvest environmental variation on the postharvest behaviour of apples (Malus domestica Borkh.) was assessed for ‘Cripps Pink’ variety apples grown in four different agroclimatic locations along the irrigated valley of Central Chile (Llancanao, Malloa, El Radal and El Parrón). The flesh firmness, total soluble solids (TSS), skin colour, internal ethylene concentration (IEC), internal browning (IB) and index of absorbance difference (IAD) were assessed in apples that had been stored at 0.5 and 2°C for 4 and 6 months and correlated with environmental parameters prior to harvest (February). There was notable variation in the IAD, percentage of red-coloured skin, TSS, firmness and IEC among the orchards at both storage temperatures, and both radial and diffuse IB were identified. Further analysis showed that the preharvest environmental conditions were correlated with the evaluated parameters, with five significant correlations (P < 0.05) being found and 63 of the 120 correlations examined having r values above 0.5. These findings indicate that preharvest environmental conditions affected fruit parameters during storage, which has implications under climate change. [ABSTRACT FROM AUTHOR]

Hemodialysis adequately controls serum uric acid (UA) levels, making UA-lowering drugs unnecessary; scant data are available for peritoneal dialysis (PD). We analyzed blood, 24 h urine and dialysis fluid from twenty patients under PD, to assess UA levels and clearances, and factors associated with better performance and maintenance of target levels (<6mg/dL). Median serum UA was 5.4 mg/dL (p25–75 4.4–5.8), mainly achieved through peritoneal clearance (3.0 mL/min/1.73m2, 71.2% of total UA clearance); 75% of participants was on UA targets. Continuous cycling peritoneal dialysis showed highest UA clearance and target achievements. These findings may be of interest for end-stage renal patients with gout. [ABSTRACT FROM AUTHOR]

Canopy development and production efficiency variations were evaluated in four sweet cherry (Prunus avium L.) cultivars: 'Bing', 'Lapins', 'Sweetheart' and 'Regina', grafted on different vigor rootstocks: 'Colt', 'Cab-6P, 'Maxma-14' and 'Gisela-12', and conducted in two training systems: Central Leader (CL) and Kym Green Bush (KGB), growing in Chile. Leaf indicators were calculated after tree defoliation. A principal components analysis (PCA) was conducted to select indicators that explain the variation among the combinations. Results showed that leaf size and number varied between different cultivar/rootstock combinations and training systems. By means of two principal components, the model employed could explain 72% of the data variability. The most relevant indicators for the PC1 were: leaf weight per hectare (0.98) and leaf area index (0.97), with a significant training system effect, whereas for the PC2 they were: leaf weight per leaf area (0.85) and production per leaf area (0.72), mainly for productive efficiency. In 'Lapins'/'Colt', the KGB system presented a higher weight and leaf area than CL, with almost double the leaf weight per hectare and leaf area index, due mainly to a 37% leaf area per tree and 20% higher tree number/ha in KGB. However, average production per leaf area reached 0.49 kg m−2, without distinction between training systems. [ABSTRACT FROM AUTHOR]

Background. It is postulated that cocoa solids possess cardioprotective capacity by various mechanisms. In the different cocoa studies evaluating cardiovascular disease, there are no conclusive data on the role it plays in controlling the lipid profile and anthropometric variables, perhaps because the concentration of cocoa, the geographical origin of the population, and the different concentrations supplied lead to a high heterogeneity of results. This study aims to estimate the effect of consuming cocoa-rich chocolate compared to placebo on the lipid profile and anthropometric variables based on data from three clinical trials conducted in Colombia. Methods. Meta-analysis of individual data from three randomized clinical trials conducted in Colombia. The entire population of the primary studies was included, which was reassigned into intervention groups if they consumed 50 grams of 70% concentrated cocoa or placebo, which was considered to be cocoa-free or with a concentration less than 50 grams. The variables at the beginning of the study were analyzed with medians, interquartile ranges, means, and deviations according to whether they met the normality assumption. Multiple imputations were used to manage missing data and were analyzed using the two approaches proposed for this type of study, that of one and two stages. In the two-stage approach, the data were weighted on a conventional Forrest plot, while in the one-stage approach, linear regressions with mixed models were applied. This study is governed by the regulations described in the 2013 Declaration of Helsinki and by article 11 of Resolution 8430 of 1993, which classifies it as a risk-free study. Results. A total of 275 participants were included, who consumed cocoa or placebo for 81 days on average; 52.7% were female and few smoked at the time of the intervention (31/275). Physical activity performed in number of hours per week was comparable between the intervention groups. When evaluating total cholesterol, low-density cholesterol (LDL), high-density cholesterol (HDL), triglycerides, abdominal circumference, and final body mass index with both the one-stage and two-stage approaches, there were no significant differences between the two groups. Conclusions. According to the results obtained in the meta-analysis, the consumption of cocoa in the Colombian population does not seem to significantly modify variables such as lipid profile, abdominal circumference, and body mass index. This conclusion according to the quality of the evidence has a weak recommendation and a low-to-moderate certainty. However, the analysis through the two proposed approaches yielded similar results. [ABSTRACT FROM AUTHOR]

This paper addresses the multistage or dynamic investment decision-making problem arising in a distribution system within a transactive energy environment. Under such a framework, three agents are involved, namely the distribution company (DISCO), the owner of distributed generation (DG) units (DGENCO), and the independent distribution system operator (IDSO). Here, we propose characterizing this planning problem as an instance of trilevel programming. In the upper level, the DISCO identifies the optimal investment plan in network assets and the best potential locations for DG in order to supply the customer demand at maximum profit. In the middle level, the DGENCO determines the best location, sizing, and timing for DG installation so that the corresponding profit is maximized. Finally, in the lower level, the IDSO is responsible for the optimal operation of the expanded distribution system. The resulting mixed-integer trilevel program is solved by a novel approach relying on Benders decomposition. The performance of the proposed approach has been illustrated with a case study based on a 37-node test system. [ABSTRACT FROM AUTHOR]

Highlights • Sunscald is an important postharvest disorder on apples Granny Smith. • Two prediction model with Vis-NIR reflectance were developed for sunscald on apples. • Model A predicted sunscald 45 days in advance on apples without sunburn at harvest. • Model B predicted sunscald 30 days in advance on apples with mild sunburn at harvest. Abstract Sunscald on apples (Malus domestica Borkh) is a physiological disorder that develops post-harvest in susceptible cultivars such as Granny Smith. Symptoms appear on the skin as dark brown areas over fruit sections that were sun exposed during its growth on the tree. Currently, there is no chemical control to prevent its appearance. The objective of this study was to develop a prediction model for this disorder using Vis/NIR reflectance. During 2013/14 and 2014/15 Granny Smith apples were harvest and classified according to their sun exposure in the field (shaded, sun-exposed) and sun injury symptom (mild, moderate, severe), and stored at 0–1 °C (> 90% RH) for 120 d. Every 15 d sunscald incidence was recorded, and spectral fingerprint taken using an optical portable spectrometer Vis/NIR (350–1100 nm). Multivariate analysis was performed using partial least squares discriminant analysis (PLS-R) and intervals PLS-DA (iPLS-DA) in order to develop calibration models and applied them to a prediction set. Two calibration models were developed. The first one (A; R2 CV = 0.41) for fruit at harvest with no sun damage symptoms (shaded and sun-exposed, n = 161), which was able to predict the appearance of sunscald 45 d in advance. The spectral ranges responsible for discrimination (iPLS-DA) of fruit with (Class 1) and without (Class 0) sunscald postharvest were: 500–525 nm, 550–575 nm, 650–675 nm, 775–800 nm, 850–875 nm, and 925–950 nm. The second model (B; R2 CV = 0.59) was developed for mild sun damaged fruit (n = 100), which predicted sunscald 30 d in advance. In this case, the spectral ranges responsible of discrimination were 500–525 nm, 650–675 nm, and 775–800 nm, related to pigments and structural properties of the tissue. The RMSEP for the independent fruit set validation models (n = 69) were 3-4-times higher than that of the calibration models, probably because biological variability. A greater number of independent fruit sets will be required to increase models' robustness and prediction capability for the industry adoption. [ABSTRACT FROM AUTHOR]

Measuring and understanding the evolution of the electricity generation efficiency sector is a relevant task for policymakers. This study focuses on assessing the determinants of electricity generation efficiency across 24 countries in Latin America and the Caribbean between 2000 and 2020. A hurdle model was employed to account for the censored nature of the dependent variable. The findings show a positive impact of opening up the electricity sector in fully efficient countries. Market liberalization and the involvement of privately owned power plants contribute to efficiency gains in inefficient countries. Additionally, the tariff protectionism level exhibits positive effects for completely efficient and inefficient countries. These results provide valuable insights, as less-efficient countries can glean strategies from their more efficient counterparts to enhance their electricity generation efficiency. [ABSTRACT FROM AUTHOR]

This paper investigates the multistage expansion planning problem of a distribution network considering reliability. Thus, the best alternative, location, and installation time for the candidate assets are identified while jointly accounting for economic and reliability aspects. As a major salient feature, the conventional simulation-based reliability assessment is equivalently implemented through algebraic expressions whereby the effect of the network topology is explicitly represented by decision variables of the optimization process. For expository purposes, the focus is placed on the expected energy not supplied, which is a widely-used metric for reliability assessment. The resulting optimization problem is cast as an instance of mixed-integer linear programming. Hence, unlike existing heuristic and metaheuristic solution techniques for reliability-constrained distribution system planning, the proposed approach is finitely convergent to the optimal solution and can be readily implemented using commercially available software. Simulation results show the effective performance of the proposed methodology. [ABSTRACT FROM PUBLISHER]

Neoliberalism has had a profound impact on the relations between the state and citizens, namely in the enjoyment of their rights. In the context of European integration, citizenship is conceptualised and practiced as a multi-level attribute, posing both challenges and opportunities, for its fulfilment. The article engages with this multilevel and multifaceted nature of citizenship in the European Union, reflecting the contested role of the nation-state in a globalised neoliberal context, as well as the consequences at the local and individual levels. The impacts on the exercise of citizenship in this context is a central concern of this article, focusing on how neoliberal globalisation has affected state-citizen relations, particularly in the context of European integration. As European integration faces a critical moment, European civil society has engaged in citizen-based organisations and movements seeking to challenge the limits of the existing political structures and demand a more participative role in society and politics. [ABSTRACT FROM AUTHOR]

In this paper, an analytical method to estimate the complex dielectric constant of liquids is presented. The method is based on the measurement of the transmission coefficient in an embedded microstrip line loaded with a complementary split ring resonator (CSRR), which is etched in the ground plane. From this response, the dielectric constant and loss tangent of the liquid under test (LUT) can be extracted, provided that the CSRR is surrounded by such LUT, and the liquid level extends beyond the region where the electromagnetic fields generated by the CSRR are present. For that purpose, a liquid container acting as a pool is added to the structure. The main advantage of this method, which is validated from the measurement of the complex dielectric constant of olive and castor oil, is that reference samples for calibration are not required. [ABSTRACT FROM AUTHOR]

In this paper, the notion of reliability assessment for distribution system applications is revisited to include a number of practices emerging in the smart grid context. The information on the variations in time of generation and demand is taken into account to establish a reference network configuration that considers the definition of an intraday reconfiguration strategy based on conventional load profiles for different categories of demand (residential, industrial, and commercial). After a fault, the service restoration process is aided by the formation of autonomous islanded subsystems (microgrids). During the restoration period, each subsystem is able to serve the local demand in a given portion of the network and to reconnect to the main network through proper synchronization. Dedicated solutions for mobile generation and storage are exploited to reach the nodes needing additional supply. A sequential Monte Carlo method is used to carry out reliability assessment. The use of this method incorporates the effects of interfering near-coincident faults and time-varying load and local generation patterns. The application on a real distribution network is presented, showing the probability distributions of the reliability indicators (power and energy not supplied), as well as the breakdown of these indicators for different demand categories. [ABSTRACT FROM AUTHOR]

A high data capacity chipless radio frequency identification (chipless-RFID) system, useful for security and authentication applications, is presented in this paper. Reading is based on the near-field coupling between the tag, a chain of identical split-ring resonators (SRRs) printed on a (typically flexible) dielectric substrate (e.g., liquid crystal polymer, plastic, and paper), and the reader. Encoding is achieved by the presence or absence of SRRs at predefined (equidistant) positions in the chain, and tag identification (ID) is based on sequential bit reading. Namely, the tag must be longitudinally displaced, at short distance, over the reader, a microstrip line loaded with an SRR and fed by a harmonic signal. By this means, the harmonic signal is amplitude modulated, and the (ID) code is contained in the envelope function, which can be obtained by means of an envelope detector. With this system, tag reading requires proximity with the reader, but this is not an issue in many applications within the domain of security and authentication (e.g., secure paper for corporate documents and certificates). Several circularly shaped 40-bit encoders (implemented in a commercial microwave substrate), and the corresponding reader, are designed and fabricated as proof-of-concept demonstrators. Strategies for programming the tags and a first proof-of-concept chipless-RFID tag fabricated on plastic substrate through inkjet printing are included in this paper. [ABSTRACT FROM PUBLISHER]

The accurate measurement of the angular displacement and velocity of reaction wheels is necessary for attitude (orientation) control in space vehicles (satellites). In this paper, microwave, contactless, and low-cost (as compared to optical encoders) sensors useful for that purpose are analyzed in detail. The sensor consists of a rotor and a stator. The rotor is a disk (or a circular crown) of dielectric material, where one or several arrays of equidistant single-loop split ring resonators (SRRs) are etched along its edge, forming circular chains of hundreds of SRRs. The stator is a coplanar waveguide (CPW) also loaded with pairs of single-loop SRRs (etched in the back substrate side), with the centers located in the slot region. The sensing principle is based on the amplitude modulation of a harmonic (single-tone continuous wave) feeding signal, achieved when the chains of the rotor are displaced over the SRR pairs of the stator. Both sensor elements (rotor and stator) must be parallel oriented, with the SRR pairs of the CPW in close proximity to the SRR chains of the rotor (and rotated 180°), in order to favor their coupling. By this means, the transmission coefficient of the CPW is varied by the circular motion of the rotor, and significant amplitude modulation of the feeding signal is achieved. From the envelope function, the angular velocity can be accurately determined. With the proposed sensors, instantaneous and practically unlimited rotation speeds can be measured. [ABSTRACT FROM PUBLISHER]

This paper presents a demand power factor-based approach (DPFA) for finding the maximum loading point (MLP) of a power system using the optimal power flow (OPF). In almost all the presented models in the literature two major drawbacks are obvious: (1) the active and reactive power demands increase equally, constantly, or at the same rate, while in the real world, this hardly ever occurs, and (2) the lack of consideration or misinterpretation of the demand power factor (DPF). This paper addresses the existing drawbacks by proposing a model based on a desired DPF, a threshold predefined by the independent system operator (ISO) that each consumer must maintain to prevent a surcharge. In the proposed DPFA, the active and reactive demands may increase differently resulting in: (1) providing a flexible loading pattern to find the best possible MLP, (2) keeping the desired DPFs at all load buses, and (3) improving the computational efficiency. To verify the DPFA, which is solvable via commercial solvers, several cases such as IEEE 14-, 30-, modified 30-, and 118-bus systems, and a large-scale 2338-bus system are conducted. Results confirm the potential, effectiveness, and superiority of the DPFA compared to the models in the literature. [ABSTRACT FROM AUTHOR]

The chayote is a species native to Mesoamerica, it is one of the highly important crops in Veracruz, which provides the largest production nationwide. This crop is susceptible to attack by various organisms, which affect the production and post-harvest life of the fruits, in addition to abiotic factors. The objective of this work was to identify the main problems that affect the cultivation of chayote, in two producing regions of the state of Veracruz, through the application of 50 inquests to producers. The results showed that in Coscomatepec each producer has a larger production area, compared to Rincon Grande, in Orizaba. In Coscomatepec, smooth green chayote is planted almost exclusively, while in Orizaba, in addition to smooth green, black Xalapa and cambray are planted. Both areas are affected by red spider mite, thrips and whitefly, mainly in the dry season. There are two diseases that occur with a significant incidence: bladder and rash, when there is high humidity in the environment (June to October). This information will allow more targeted studies to be carried out to design preventive and control measures during chayote production. [ABSTRACT FROM AUTHOR]

This paper focuses on the analysis of splitter/ combiner microstrip sections where each branch is loaded with a complementary split ring resonator (CSRR). The distance between CSRRs is high, and hence, their coupling can be neglected. If the structure exhibits perfect symmetry with regard to the axial plane, a single transmission zero (notch) at the fundamental resonance of the CSRR, arises. Conversely, two notches (i.e., frequency splitting) appear if symmetry is disrupted, and their positions are determined not only by the characteristics of the CSRRs but also by the length of the splitter/combiner sections. A model that includes lumped elements (accounting for the CSRR-loaded line sections) and distributed components (corresponding to the transmission lines) is proposed and used to infer the position of the transmission zeros. Frequency splitting is useful for the implementation of differential sensors and comparators based on symmetry disruption. Using the model, the length of the splitter/combiner sections necessary to optimize the sensitivity of the structures as sensing elements is determined. Parameter extraction and comparison with electromagnetic simulations and measurements in several symmetric and asymmetric structures is used to validate the model. Finally, a prototype device sensor/comparator based on the proposed CSRR-loaded splitter/combiner microstrip sections is presented. [ABSTRACT FROM PUBLISHER]

In this paper, several configurations of splitter/combiner microstrip sections loaded with stepped impedance resonators (SIRs) are analyzed. Such structures are useful as sensors and comparators, and the main aim of the paper is to show that the proposed configurations are useful for the optimization of sensitivity and discrimination. Specifically, for comparison purposes, i.e., to determine anomalies, abnormalities or defects of a sample under test (SUT) in comparison to a reference sample, it is shown that up to three samples can be simultaneously tested. Simple models of the proposed structures are presented, and these models are validated through electromagnetic simulation and experiment. Finally, the principle of operation is validated through a proof-of-concept demonstrator. [ABSTRACT FROM AUTHOR]

• Ionic liquids for the selective extraction of levulinic acid/formic acid • A COSMO-RS screening identifies phosphonium based ionic liquids as suitable • Steric hindrance is the effect that dominates the selectivity towards both acids • Liquid-liquid equilibrium experiments show the feasibility of the screened solvent • NRTL was able to correlate experimental liquid-liquid equilibrium data The separation of Levulinic (LA) acid and Formic acid (FA) from aqueous streams represents an important and challenging separation in biorefineries, where ionic liquids (ILs) provide a sustainable environment for liquid-liquid extractions of these acids. In this work, a COSMO-RS screening of bis (trifluoromethylsulfonil)imide [Tf 2 N]− based IL was first conducted and then followed by experimental validation to search for the most suitable cation for this separation. After the screening, ternary liquid-liquid equilibrium experiments at 298.15K and the subsequent data correlation using the Non-Random Two Liquid model (NRTL) were performed for future industrial implementation. Results indicated that the phosphonium cations, especially the trihexylthetradecyl phosphonium cation [P 66614 ]+, produced the highest selectivity rates among all the experimentally measured ILs. [ABSTRACT FROM AUTHOR]

Due to the rapid growth in the amount of wind energy connected to distribution grids, they are exposed to higher network constraints, which poses additional challenges to system operation. Based on regulation, the system operator has the right to curtail wind energy in order to avoid any violation of system constraints. Energy storage systems (ESS) are considered to be a viable solution to solve this problem. The aim of this paper is to provide the best locations of both ESS and wind power by optimizing distribution system costs taking into account network constraints and the uncertainty associated to the nature of wind, load and price. To do that, we use a mixed integer linear programming (MILP) approach consisting of loss reduction, voltage improvement and minimization of generation costs. An alternative current (AC) linear optimal power flow (OPF), which employs binary variables to define the location of the generation, is implemented. The proposed stochastic MILP approach has been applied to the IEEE 69-bus distribution network and the results show the performance of the model under different values of installed capacities of ESS and wind power. [ABSTRACT FROM AUTHOR]

This paper develops an energy policy measure for renewable sources in Colombia, in particular wind generation. The proposal is done at the decentralized level, in isolated areas of the country, where electricity coverage is below 12% and wind speed is suitable for power generation. The goal of this policy is focused on increasing electricity coverage in those remote areas of the country that have high winds in order to develop clean generation investments that can represent a benefit for low-income users. Thus, a mechanism for financing these kinds of investments is proposed, involving the private sector and using the mechanism known as Public Private Partnerships – PPPs. PPPs are mechanisms used by the public sector to establish a contract with the private sector. The private sector provides capital and ability to develop projects, while the public sector holds the responsibility in service delivery. To model the relationship between public sector and private investors, a bilevel programming method for efficient resource allocation, combining an auction mechanism and moral hazard, is presented. A case study is shown in the Colombian context. [ABSTRACT FROM AUTHOR]

AMATLAB/SIMULINK software simulation model (structure and component blocks) has been constructed in order to view and analyze the potential of the PSD (Position Sensitive Detector) array concept technology before it is further expanded or developed. This simulation allows changing most of its parameters, such as the number of elements in the PSD array, the direction of vision, the viewing/scanning angle, the object rotation, translation, sample/scan/simulation time, etc. In addition, results show for the first time the possibility of scanning an object in 3D when using an a-Si:H thin film 128 PSD array sensor and hardware/software system. Moreover, this sensor technology is able to perform these scans and render 3D objects at high speeds and high resolutions when using a sheet-of-light laser within a triangulation platform. As shown by the simulation, a substantial enhancement in 3D object profile image quality and realism can be achieved by increasing the number of elements of the PSD array sensor as well as by achieving an optimal position response from the sensor since clearly the definition of the 3D object profile depends on the correct and accurate position response of each detector as well as on the size of the PSD array. [ABSTRACT FROM AUTHOR]

This paper addresses the multistage expansion planning problem of a distribution system where investments in the distribution network and in distributed generation are jointly considered. Network expansion comprises several alternatives for feeders and transformers. Analogously, the installation of distributed generation takes into account several alternatives for conventional and wind generators. Unlike what is customarily done, a set of candidate nodes for generator installation is considered. Thus, the optimal expansion plan identifies the best alternative, location, and installation time for the candidate assets. The model is driven by the minimization of the net present value of the total cost including the costs related to investment, maintenance, production, losses, and unserved energy. The costs of energy losses are modeled by a piecewise linear approximation. As another distinctive feature, radiality conditions are specifically tailored to accommodate the presence of distributed generation in order to avoid the isolation of distributed generators and the issues associated with transfer nodes. The resulting optimization problem is a mixed-integer linear program for which finite convergence to optimality is guaranteed and efficient off-the-shelf software is available. Numerical results illustrate the effective performance of the proposed approach. [ABSTRACT FROM AUTHOR]

This study presents a risk-assessment approach to the reactive power planning problem. Chance-constrained programming is used to model the random equivalent availability of existing reactive power sources for a given confidence level. Load shedding because of random equivalent availability of those reactive power sources is implemented through conditional-value-at-risk. Tap settings of under-load tap-changing transformers are considered as integer variables. Active and reactive demands are considered as probability distribution functions. The proposed mathematical formulation is a two-stage stochastic, multi-period mixed-integer convex model. The tradeoff between risk mitigation and investment cost minimisation is analysed. The proposed methodology is applied to the CIGRE-32 electric power system, using the optimisation solver CPLEX in AMPL. [ABSTRACT FROM AUTHOR]

This study presents a risk‐assessment approach to the reactive power planning problem. Chance‐constrained programming is used to model the random equivalent availability of existing reactive power sources for a given confidence level. Load shedding because of random equivalent availability of those reactive power sources is implemented through conditional‐value‐at‐risk. Tap settings of under‐load tap‐changing transformers are considered as integer variables. Active and reactive demands are considered as probability distribution functions. The proposed mathematical formulation is a two‐stage stochastic, multi‐period mixed‐integer convex model. The tradeoff between risk mitigation and investment cost minimisation is analysed. The proposed methodology is applied to the CIGRE‐32 electric power system, using the optimisation solver CPLEX in AMPL. [ABSTRACT FROM AUTHOR]

A method based on Empirical Martingale Simulation (EMS) is presented to evaluate investments in wind energy. Risk-neutral prices are calculated, where electricity market prices are modeled using an ARIMA–GARCH method which shows conditional heteroskedasticity. The values of the put options are calculated a week ahead and it is observed that wind producers that invest in the options market can hedge against price risk and can also maximize their benefits. The use of Monte Carlo simulation with the EMS method in periods of high volatility is especially useful for investors facing price volatilities in order to improve their returns. The model is applied to the Colombian electricity market. [ABSTRACT FROM AUTHOR]

The World Health Organization (WHO) Mental Health Action Plan 2013-2020 urges its Member States to strengthen leadership in mental health, ensure mental and social health interventions in community-based settings, promote mental health and strengthen information systems, and increase evidence and research for mental health. Although Costa Rica has strongly invested in public health and successfully reduced the burden of nutritional and infectious diseases, its transitional epidemiological pattern, population growth, and immigration from unstable neighboring countries has shifted the burden to chronic disorders. Although policies for chronic disorders have been in place for several decades, mental disorders have not been included. Recently, as the Ministry of Health of Costa Rica developed a Mental Health Policy for 2013-2020, it became evident that the country needs epidemiological data to prioritize evidence-based intervention areas. This article stresses the importance of conducting local epidemiological studies on mental health, and calls for changes in research funding priorities by public and private national and international funding agencies in order to follow the WHO Mental Health Action Plan. [ABSTRACT FROM AUTHOR]

Wind energy is present in many countries throughout the world. The main types of wind sales in electricity markets are via regulated tariffs or pool-based markets. Production companies choose cost-effective options for selling wind energy, and some markets, like the Irish electricity market, use regulated tariffs to remunerate wind production. This paper aims to provide some answers to explain what effect wind offers may have in an electricity market if wind power producers participated in the day-ahead market without receiving any premium or aid. A price-maker optimization model is used to detect its effect on prices. The model encompasses energy offers by other technologies using residual demand curves and detailed modeling of wind imbalances. It is observed that wind acting as price-maker reduces electricity prices and the imbalance penalties help the system operator to reduce imbalances. A realistic case study using data from the Irish electricity market illustrates the methodology used comparing the effect of imbalance penalties in the models in terms of profit and total imbalance of the system. [ABSTRACT FROM AUTHOR]

Intermittence and variability of renewable resources is often a barrier to their large scale integration into power systems. We propose a stochastic real-time unit commitment to deal with the stochasticity and intermittence of non-dispatchable renewable resources including ideal and generic energy storage devices. Firstly, we present a mathematical definition of an ideal and generic storage device. This storage device definition has some mathematical advantages: 1) it can be easily integrated within complex optimization problems, 2) it can be modeled using linear programming, suitable for practical large-scale cases. Secondly, a stochastic unit commitment with ideal and generic storage devices and intermittent generation is proposed to solve the joint energy-and-reserves scheduling and real-time power balance problem, reflecting the minute-by-minute intermittent changes and the stochasticity of renewable resources. We also compare our results with those obtained using a deterministic unit commitment with perfect information. The proposed model is illustrated with a 24-bus system. [ABSTRACT FROM AUTHOR]

Highlights: [•] The color sensing ability of a data acquisition prototype system integrating a 32 linear array of 1D amorphous silicon position sensitive detectors (PSD) was analyzed. [•] We show that such a sensor system can differentiate primary red, green, blue (RGB) and derived colors. [•] An incident beam with an RGB color combination was employed and adequate integration times were set taking into account that a color surface mostly reflects its corresponding color. [•] A mean colorimetric error of 25.7 was obtained. [•] We show that color detection is possible via the use of this sensor array system, composed by a simpler amorphous silicon pin junction. [Copyright &y& Elsevier]

Thermal generators' emissions constitute an externality on which a regulator might wish to impose constraints. In addition, transmission capacity for sending energy may be naturally restricted by the grid facilities. Both pollution standards and transmission capacity impose constraints, coupling the strategies of the agents in their joint strategy space. To force competitive electricity generators to respect those constraints when individual monitoring is unavailable we envisage the regulator solving a generalized Nash equilibrium problem to establish an equilibrium in which the joint constraints are satisfied. If the regulator appropriately modifies the generators' payoffs then they will play a decoupled game in which they can ignore the information on the joint constraints. For the payoff modification to induce the required behavior, a coupled constraints equilibrium needs to exist and be unique. We borrow from the electrical engineering (EE) literature a three-node network model that has these properties and use it in this paper to discuss and explain the behavior of the agents subjected to the coupled constraints. We find that the imposition of transmission and environmental restrictions may increase the output share of an inefficient generator and decrease consumer surplus. [ABSTRACT FROM AUTHOR]

This paper presents a new approach for the joint energy and reserves scheduling and unit commitment with n-K reliability constraints for the day-ahead market. The proposed method includes a novel n-K criterion where demand must be met with a specified probability under any simultaneous loss of K generating units. A chance-constrained method is proposed with an \alpha-quantile measure to determine the confidence level to meet the demand under K simultaneous contingencies. The chance-constrained optimization problem is recast as a mixed integer linear programming optimization problem. Wind and demand uncertainty are included into the model. The methodology proposed is illustrated with several case studies where the effect of increasing wind power penetration is analyzed showing the performance of our model. [ABSTRACT FROM PUBLISHER]

Wind and hydro technologies represent an important part of the electricity generation sector. However, there have been few detailed studies that have investigated the synergies resulting from their combined operation. To address that, we formulate three optimization models where wind and reversible hydro technologies bid in a day-ahead market. The bidding strategies are divided into three categories: 1) separate wind and reversible hydro offers without a physical connection between them, 2) separate wind and reversible hydro offers with a physical connection to store by pumping the wind energy surplus, and 3) single wind and reversible hydro offers with a physical connection. Risk is considered in the models by means of the conditional value at risk (CVaR). A comparison of the models and relevant conclusions are drawn from an illustrative case study of the Iberian day-ahead electricity market. [ABSTRACT FROM PUBLISHER]

This paper presents a stochastic mixed-integer linear programming (SMILP) approach to maximize total expected profit of one price-maker hydro producer in a pool-based electricity market. Head dependence, commitment decisions, discharge ramping, startup costs and forbidden zones are all effectively handled in our approach. Uncertainty about the competitors' offers is adequately represented by residual demand curves (RDCs) scenarios. The management of risk is suitably addressed by conditional value-at-risk (CVaR) to provide the efficient frontier, i.e., the solutions set for which the expected profit may not be augmented without enlarging the variance of profit. Appropriate offering strategies to the pool are also developed, consisting of supply functions built for different risk levels. A representative cascaded hydro system with 7 reservoirs is considered to analyze and compare risk-neutral versus risk-averse results. [ABSTRACT FROM PUBLISHER]

This paper presents a model for long-term reactive power planning where a deterministic nonlinear model is expanded into a multi-stage stochastic model under load uncertainty and an N-k contingency analysis. Reactive load shedding is introduced in the objective function to measure the reactive power deficit after the planning process. The objective is to minimize the sum of investment costs (IC), expected operation costs (EOC) and reactive load shedding costs optimizing the sizes and locations of new reactive compensation equipment to ensure power system security in each stage along the planning horizon. An efficient scenario generation and reduction methodology is used for modeling uncertainty. Expected benefits are calculated to establish the performance of the expected value with perfect information (EVPI) and the value of the stochastic solution (VSS) methodologies. The efficacy of the proposed model is tested and justified by the simulation results using the Ward-Hale 6-bus and the IEEE 14-bus systems. [ABSTRACT FROM PUBLISHER]

A review of the fundamentals of distributed amplification is presented along with the design and performance of a novel dual-band/diplexer monolithic distributed amplifier based on the combination of CRLH and RH transmission lines. The MMIC prototype, operating in the C-band and featuring a 10 dB gain with less than −20 dB crosstalk levels, represents the first monolithic implementation in GaN technology for this type of topology. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1041-1045, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27471 [ABSTRACT FROM AUTHOR]

Different regulatory frameworks have implemented competitive mechanisms to increase efficiency in transmission, a natural monopoly. Conflicts of interest and hidden costs make necessary to define methods to obtain an appropriate valuation of new transmission assets. [ABSTRACT FROM PUBLISHER]

This paper is the second of a two-paper series and presents a model to assess and promote investment projects defined in a plan of expansion of the transmission. We propose a model that consists of three main elements: valuation of a project based on the design of a linear contract, a principal-agent model to assess the optimal effort of an agent, and the right-of-way negotiating cost. We also define a model to evaluate bids by the agents. The value of the project depends on the number of competitors, the incentives to invest, and the right-of-way costs. The right-of-way cost is approached from the perspective of a bilateral bargaining problem. [ABSTRACT FROM PUBLISHER]

Abstract: Listeria monocytogenes is an important agent of foodborne disease, showing low prevalence but high mortality. There is evidence that vegetables are important vehicles of transmission, especially those minimally processed (fresh, fresh-cut vegetables under modified atmosphere packaging (MAP) or frozen) and directly exposed to consumers. The aim of this work was to detect and enumerate viable L. monocytogenes cells by culture and molecular methods from vegetable foods. A total of 191 vegetable samples (fresh, frozen and fresh-cut under modified atmosphere packaging) were studied. L. monocytogenes was detected and identified by selective plating, PCR and DVC-FISH. An isolation rate of 4.19% was obtained by culture, with a higher incidence in frozen vegetables. Six isolates belonged to serotype 1/2a and 2 to 4b. Counts were below <100 cfu/g for the eight positive samples, according to the food safety criteria established for the RTE by Commission Regulation EC No 1441/2007. Multiplex PCR method yielded a greater number of positive samples (10.47%). DVC-FISH technique determined that viable cells of L. monocytogenes were present in 32.98% of the samples, containing up to 4.97 log10 viable cells/g. [Copyright &y& Elsevier]

The main objective of this research is the contract pricing calculation of distributed generation (dg) considering its interaction with the distribution company. The proposed methodology consists in modeling the DG energy trading using game theory concepts and bilevel programming. To validate the proposed methodology several tests are carried out with a 34 bus distribution system, changing the number and size of the dg units. The contract prices calculated with this methodology represent an equilibrium between the profit maximization pursued by the DG owner and the minimization of payments procured by the distribution company. Consequently, it can be concluded that the proposed methodology provides efficient incentives for both agents, providing a solution in which the DG and the distribution company are mutually beneficial. Furthermore, the location of the DG units can also be considered in the model, so that not only the contract price but also the equilibrium location can be found. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents an approach based on a specialized genetic algorithm (GA) to determine the location and contract pricing of dispatchable distributed generation (DG) units in distribution systems. The proposed approach is based on a nonlinear bilevel programming framework that involves the interests of two different agents: the DG owner who procures the maximization of the profits obtained from the energy sales, and the Distribution Company (DisCo), which procures the minimization of the payments incurred in attending the forecasted demand. To meet the forecasted demand the DisCo can purchase energy either from the wholesale energy market or from the DG units within its network. The proposed GA determines both the location and contract pricing of the DG units that would render maximum profits to the DG owner, subject to the minimization of payments procured by the DisCo. To show the effectiveness of the proposed approach, several tests were carried out on a modified IEEE 34-bus and 85-bus distribution networks. [Copyright &y& Elsevier]

We investigate the performance of two hybrid forecasting models to predict the next-day base load electricity prices on the APX power exchange for Great Britain. Hybrid models have often been advocated as a synthetic method for forecasting, but it is an open question how well they perform at the day-ahead stage. A conventional hybrid approach combines a fundamental model, formulated with supply stack modeling, with an econometric model using data on price drivers. We extend this model to one based upon logistic smooth transition regression, which represents a regime-switching for periods of structural change. Empirical results for out-of-sample forecasting using both hybrid approaches are discussed and compared to non-hybrid time series forecasting methods. [ABSTRACT FROM PUBLISHER]

Abstract: Background: Bipolar disorder (BPD) has been associated with variations in personality dimensions, but the nature of this relationship has been unclear. In this study, the heritabilities of BPD and the Big Five personality factors and the genetic correlations between BPD and personality factors are reported. Methods: The participants in this study were 1073 individuals from 172 families of Mexican or Central American ancestry. Heritabilities and genetic correlations were calculated under a polygenic model using the maximum-likelihood method of obtaining variance components implemented in the SOLAR software package. Results: Heritabilities of 0.49, 0.43, and 0.43 were found for the narrowest phenotype (schizoaffective bipolar and bipolar I), the intermediate phenotype (schizoaffective bipolar, bipolar I, and bipolar II), and the broadest phenotype (schizoaffective bipolar, bipolar I, bipolar II, and recurrent depression), respectively. For the Big Five personality factors, heritabilities were 0.25 for agreeableness, 0.24 for conscientiousness, 0.24 for extraversion, 0.23 for neuroticism, and 0.32 for openness to experience. For the narrowest phenotype, a significant negative correlation (−0.32) with extraversion was found. For the broadest phenotype, negative correlations were found for agreeableness (−0.35), conscientiousness (−0.39), and extraversion (−0.44). A positive correlation (0.37) was found with neuroticism. Limitations: It is not possible to determine whether aspects of personality are factors in the development of bipolar disorder or vice versa. The short form of the NEO does not provide the ability to examine in detail which facets of extraversion are most closely related to bipolar disorder or to compare our results with studies that have used the long version of the scale. Conclusions: This study establishes a partial genetic basis for the Big Five personality factors in this set of families, while the environmental variances demonstrate that non-genetic factors are also important in their influence on bipolar and personality phenotypes. BPD may be most associated with decreased extraversion (less interaction with one''s surroundings) because patients spend more time in depressive than manic states. [Copyright &y& Elsevier]

Starting from the hermeneutics of Gadamer, this article interprets the positions assumed by Grondin, Zabala and Ortiz-Osés about the meaning of being as a creation or dation, mediation and responsibility. The condition of existing and being in the world is philosophically a mode of existence shared between ethics and polis. The current interpretation refers to the project of good, fulfilled in a commitment to justice and truth with others. In any space for the interpretation and comprehension of existence, the context of being takes its inter-subjective meaning of possible facticity in conditions of otherness. [ABSTRACT FROM AUTHOR]

This paper presents a model for solving the multistage planning problem of a distribution network. The objective function to be minimized is the net present value of the investment cost to add, reinforce or replace feeders and substations, losses cost, and operation and maintenance cost. The model considers three levels of load in each node and two investment alternatives for each resource to be added, reinforced or replaced. The nonlinear objective function is approximated by a piecewise linear function, resulting in a mixed integer linear model that is solved using standard mathematical programming. The model allows us to find multiple solutions in addition to the optimal one, helping the decision maker to analyze and choose from a pool of solutions. In addition to the optimization problem, reliability indexes and associated costs are computed for each solution, based on the regulation model used in Brazil. Numerical results and discussion are presented for an illustrative 27-node test network. [ABSTRACT FROM AUTHOR]

We present a compact formulation to find all pure Nash equilibria in a pool-based electricity market with stochastic demands. The equilibrium model is formulated as a stochastic equilibrium problem subject to equilibrium constraints (EPEC). The problem is based on a Stackelberg game where the generating companies (GENCOs) optimize their strategic bids anticipating the solution of the independent system operator (ISO) market clearing. A finite strategy approach both in prices and quantities is applied to transform the nonlinear and nonconvex set of Nash inequalities into a mixed integer linear problem (MILP). A procedure to find all Nash equilibria is developed by generating “holes” that are added as linear constraints to the feasibility region. The result of the problem is the set of all pure Nash equilibria and the market clearing prices and assigned energies by the ISO. A case study illustrates the methodology and proper conclusions are reached. [ABSTRACT FROM PUBLISHER]

A mixed integer nonlinear programming (MINLP) model for scheduling of the short-term integrated operation of a series of price-taker hydroelectric plants (H-GENCO) along a cascaded reservoir system in a pool-based electricity market is presented. The objective of the H-GENCO can be either to maximize profit, taking into account technical efficiency, or to maximize technical efficiency, maintaining a profit level. In both cases, the efficiency can be accurately obtained using the “Hill diagram” supplied by turbine manufacturers. A multiple nonlinear regression analysis of the unit's technical efficiency is estimated as a quadratic function of net head and water discharge. Several case studies of realistic dimensions are described, where results indicate that a profit-based MINLP produces better results compared to an MILP model, on the other hand, higher efficiencies and water savings are obtained in the efficiency-based model. [ABSTRACT FROM PUBLISHER]

Abstract: In competitive electricity markets, companies simultaneously offer their productions to obtain the maximum profits on a daily basis. In the long run, the strategies utilized by the electric companies lead to various long-term equilibria that can be analyzed with the appropriate tools. We present a methodology to find plausible long-term Nash equilibria in pool-based electricity markets. The methodology is based on an iterative market Nash equilibrium model in which the companies can decide upon their offer strategies. An exponential smoothing of the bids submitted by the companies is applied to facilitate the convergence of the iterative procedure. In each iteration of the model the companies face residual demand curves that are accurately modeled by Hermite interpolating polynomials. We introduce the concept of meta-game equilibrium strategies to allow companies to have a range of offer strategies where several pure and mixed meta-game Nash equilibria are possible. With our model it is also possible to model uncertainty or to generate price scenarios for financial models that assess the value of a generating unit by real options analysis. The application of the proposed methodology is illustrated with several realistic case studies. [ABSTRACT FROM AUTHOR]

The movement of a micro cantilever was detected via a self constructed portable data acquisition prototype system which integrates a linear array of 32 1D amorphous silicon position sensitive detectors (PSD). The system was mounted on a microscope using a metal structure platform and the movement of the 30 μm wide by 400 μm long cantilever was tracked by analyzing the signals acquired by the 32 sensor array electronic readout system and the relevant data algorithm. The obtained results show a linear behavior of the photocurrent relating X and Y movement, with a non-linearity of about 3%, a spatial resolution of less than 2 μm along the lateral dimension of the sensor as well as of less than 3 μm along the perpendicular dimension of the sensor, when detecting just the micro-cantilever, and a spatial resolution of less than 1 μm when detecting the holding structure. [ABSTRACT FROM AUTHOR]