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The nucleus accumbens shell (NAcSh) integrates reward information through diverse and specialized neuronal ensembles, influencing decision-making. By training rats in a probabilistic choice task and recording NAcSh neuronal activity, we found that rats adapt their choices based solely on the presence or absence of a sucrose reward, suggesting they build an internal representation of reward likelihood. We further demonstrate that NAcSh ensembles dynamically process different aspects of reward-guided behavior, with changes in composition and functional connections observed throughout the reinforcement learning process. The NAcSh forms a highly connected network characterized by a heavy-tailed distribution and the presence of neuronal hubs, facilitating efficient information flow. Reward delivery enhances mutual information, indicating increased communication between ensembles and network synchronization, whereas reward omission decreases it. Our findings reveal how reward information flows through dynamic NAcSh ensembles, whose flexible membership adapts as the rat learns to obtain rewards (energy) in an ever-changing environment.

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The aim of the present research was to determine if the developed ovo-vegetarian sausage (SO), which was made with 15% chickpea flour, 51% albumin and 34% soy protein concentrate, exhibited improved physicochemical and sensory characteristics compared to vegetarian sausages available on the local market (classic vegan sausage, SC; vegan fine herb sausage, SH; and quinoa sausage, SQ). According to the physicochemical results, the developed sample, SO, presented significant differences (p < 0.05) compared to the others, including higher protein content, lower pH and a higher a* value. Three types of sensory analyses were conducted-flash profile, overall liking and purchase intention (to determine consumers' willingness to purchase the product)-with the first involving 15 consumers and the second and third involving 60 participants each. Descriptors for each sample were determined using the vocabulary provided by consumers in the flash profile analysis. Descriptors for SO included 'elastic', 'smell of cooked corn', 'characteristic flavor', 'pasty', 'soft' and 'pastel color', contributing to its greater overall liking and purchase intention compared to the others. Through the hierarchical multiple factor analysis, a positive correlation was observed between the texture and sensory descriptors of the flash profile. Conversely, a correlation was found between the physicochemical characteristics (pH, aw, color) and overall liking and purchase intention.

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This research aimed to assess the influence of red dragon fruit peels ratio (RDF-PR) from two species, Hylocereus hybridum (HH) and Hylocereus undatus (HU), and particle size (PS) on quality parameters of red dragon fruit peel powder (RDF-PP) and its further application in emulsified alpaca-based sausages as partial substitutes of pork-back fat. A three-level full factorial design (nine treatments) was employed to evaluate the effect of RDF-PR (HH(0%):HU(100%), HH(50%):HU(50%), and HH(100%):HU(0%)) and PS (499-297, 296-177, and <177 µm) on the dependent variables: L*, a*, b*, C, h°, water-holding capacity, oil-holding capacity, swelling capacity, pectin yield, degree of esterification (analysed through FT-IR), and crude fibre content. The data analysed through a response surface methodology showed that treatment one (T1) is the best with the optimised conditions at 100% HU RDF-PR and PS of <177 µm. The statistical validation of T1 exhibited the highest water-holding capacity (32.1 g/g peel), oil-holding capacity (2.20 g oil/g peel), and pectin yield (27.1%). A completely randomised design (four formulations) was then used to assess the effect of partial replacement of pork-back fat by T1 in emulsified alpaca-based sausages on the colourimetric, physicochemical, and texture properties (hardness, chewiness, cohesiveness, springiness, adhesiveness, and adhesive force). Likewise, a sensory hedonic scale was employed to evaluate the appearance, colour, odour, flavour, texture, and overall acceptability of sausages. The results revealed that 65.7% of pork-back fat content was successfully replaced compared with a control formulation. Additionally, F3 showed significantly (p < 0.05) better colourimetric, physicochemical, and textural characteristics, such as lower hardness (34.8 N) and chewiness (21.7 N) and higher redness (a* = 19.3) and C (22.9), compared to a control formulation. This research presents RDF-PP as a promising fat substitute for developing healthier, reduced-fat meat products using fibre-rich agroindustry by-products.

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Diferencias en las características de la infraestructura verde pueden variar la relación entre los espacios verdes urbanos y el precio de la vivienda (PV). El objetivo de este estudio es estimar el efecto de la proximidad de áreas verdes con diseño antrópico (AVDA) y de un humedal, sobre los valores del mercado de vivienda. Mediante uso de sistemas de información geográfica se determinó el tamaño de áreas verdes próximas al humedal y otros atributos de localización de las viviendas; los precios de los inmuebles se obtuvieron en el mercado de finca raíz en Bogotá. Con mínimos cuadrados ordinarios se relacionó el PV con atributos ambientales, de localización y socioeconómicos; el Índice de Moran, modelos de contigüidad y error espaciales permitieron analizar la dependencia espacial de los datos. El AVDA y no el humedal, estuvo significativamente asociada con el PV Las regresiones realizadas mostraron la ausencia de dependencia espacial entre los datos, así como una asociación positiva del PV con las AVDA, el área del inmueble y el número de alcobas. Mientras que la edad de las viviendas y la distancia al Comando de Atención Inmediata (CAI) tuvieron una asociación negativa con el PV. Estos resultados muestran que los residentes locales pagan más por vivir cerca a áreas con AVDA y tienen implicaciones para la planificación urbana de estratos socioeconómicos altos. Los valores estimados en este trabajo pueden ser utilizados para alimentar un análisis costo-beneficio en evaluaciones para la construcción, ampliación y rehabilitación de espacios verdes urbanos. Se recomienda realizar un estudio semejante, en vecindarios de menores ingresos económicos que permitan definir también la tipología de AVDA factible de pagar y que al mismo tiempo proporcione servicios ecosistémicos culturales.

Differences in the characteristics of green infrastructure can vary the relationship between urban green spaces and housing prices. The objective of this study is to estimate the effect of the proximity of anthropically designed green areas and a wetland on housing market values. Using geographic information systems, the size of green areas near the wetland and other attributes of housing location were determined; property prices were obtained from the real estate market in Bogota. Ordinary least squares was used to relate the housing prices to environmental, location and socioeconomic attributes; the Moran Index, contiguity models and spatial error models were used to analyze the spatial dependence of the data. The anthropically designed green areas, and not the wetland, was significantly associated with the housing prices. The regressions performed showed the absence of spatial dependence among the data, as well as a positive association of housing prices with anthropically designed green areas, property area and number of alcoves. While the age of the dwellings and the distance to the Immediate Attention Command had a negative association with housing prices. These results show that local residents pay more to live near areas with anthropically designed green areas and have implications for urban planning for high socioeconomic strata. The values estimated in this work can be used to feed a cost-benefit analysis in evaluations for the construction, expansion, and rehabilitation of urban green spaces. It is recommended that a similar study be conducted in lower income neighborhoods to define the type of anthropically designed green areas that can be afforded and at the same time provide cultural ecosystem services.

As diferenças nas características da infra-estrutura verde podem variar a relação entre o espaço verde urbano e os preços da habitação (PH). O objetivo deste estudo é estimar o efeito da proximidade de áreas verdes antropogenicamente projetadas (AVAP) e de um pântano sobre os valores do mercado imobiliário. Usando sistemas de informação geográfica, foi determinado o tamanho das áreas verdes próximas ao pântano e outros atributos de localização habitacional; os preços dos imóveis foram obtidos do mercado imobiliário em Bogotá. Os mínimos quadrados comuns foram usados para relacionar a PV aos atributos ambientais, de localização e sócio-econômicos; os modelos do Índice Moran, contiguidade e erro espacial foram usados para analisar a dependência espacial dos dados. A AVAP e não a zona úmida, foi significativamente associada à PV. As regressões mostraram a ausência de dependência espacial entre os dados, bem como uma associação positiva de PH com AVAP, área da propriedade e número de alcovas. Enquanto a idade das moradias e a distância até o Comando de Atenção Imediata (CAI) tinham uma associação negativa com o PV Estes resultados mostram que os residentes locais pagam mais para viver perto de áreas com AVAP e têm implicações no planejamento urbano para altos estratos sócio-econômicos. Os valores estimados neste trabalho podem ser usados para alimentar uma análise de custo-benefício em avaliações para a construção, extensão e reabilitação de espaços verdes urbanos. Recomenda-se que seja realizado um estudo semelhante nos bairros de menor renda para também definir o tipo de AVAP que pode ser oferecido ao mesmo tempo em que fornece serviços culturais ecossistêmicos.

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The palatability and concentration of sweet foods promote hedonic feeding beyond homeostatic need. Understanding how neurons respond to sweet taste is thus of great importance. The dorsomedial nucleus accumbens shell (dNAcMed) is considered a "sensory sentinel," promoting hedonic feeding. However, it is unknown how neurons in the lateral part (NAcLat) respond to oral sucrose stimulation. Using in vivo calcium imaging of individual D1 and D2 cells in NAcLat of mice performing behavioral licking tasks, we find that D1 and D2 neurons do not act as single homogeneous populations. Instead, their responses are organized into ensembles with context-dependent temporal dynamics around licking sucrose. At the macrostructure of licking (meals), D1 and D2 population activity recorded on the first day predict the licking behavior on subsequent days. However, at the level of the microstructure of licking (bouts), calcium activity increased concurrently in D1 and D2 neurons prior to licking bouts, whereas during licking, calcium signals decreased. Importantly, in a Brief Access Taste Task, calcium responses for D1 and D2 exhibit much more heterogeneity than during a freely licking task. Specifically, D1 and D2 neurons form distinct ensembles: some ramp up in anticipation of the first lick, some respond at the end of the taste-access period, and some categorize sucrose concentrations as low or high. Collectively, NAcLat D1 and D2 neurons are organized in ensembles that adapt to the behavioral context to monitor task-relevant events and sucrose concentrations.

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The Power of Food Scale (PFS) is a questionnaire for self-assessing the motivation to consume palatable foods, especially in environments where food is abundant and constantly available. This study aimed to a) assess the factorial structure of the PFS in a Brazilian sample and b) examine the relationship between the power of food and body image dissatisfaction and BMI. The PFS and Body Shape Questionnaire (BSQ) were applied to a sample of 300 adults. Data were analysed using confirmatory factor analysis. Composite reliability (CR) was used to verify factor reliability. A partial least squares structural equation model was used to verify the effect of the PFS score on body image dissatisfaction. The PFS had an adequate factorial structure in this Brazilian sample, showing three well-defined factors: food available (CR = 0.91), food tasted (CR = 0.84), and food present (CR = 0.87). The BSQ showed one reliable factor (CR = 0.97). The power of the food aggregate factor significantly predicted body mass index (ß = 0.16; p = .01) and body image dissatisfaction (ß = 0.46; p < .001). The effect size was small for body mass index (f2 = 0.02) and medium for body image dissatisfaction (f2 = 0.26). The food present factor also had a slightly higher average among the three PFS factors. Women had higher PFS scores than men. Understanding the role that this motivation plays in physical and psychological outcomes such as body dissatisfaction can contribute to developing treatment strategies and support health professionals' performance in clinical settings.

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This study aimed to evaluate the sensory profile of gluten-free bread with Amorphophallus konjac (AK) flour in different concentrations. This experimental study is divided into three steps: preparation of the gluten-free bread formulations, sensory analysis, and statistical analysis. The addition of Konjac flour in a gluten-free bread formulation was tested in different proportions, 12.5%, 25%, 37.5%, and 50% of the flour content. The checking all-that-apply (CATA) was conducted with 110 panelists; among these, 43 were consumers of gluten-free bread. Sensory analysis was conducted using a 9-point hedonic scale for color, aroma, texture, flavor, appearance, and overall acceptability. The AK flour influenced the sensory characteristics of gluten-free bread. Bread with characteristics closer to those found in bread with gluten was the one with 12.5% of konjac flour for both the acceptability analysis as the attributes raised through a detailed CATA map. The control sample is located next to features like dry appearance, dry texture and grainy, dark color, and salty. Therefore, 12.5% AK gluten-free bread is closer to the characteristics of the control sample, such as light crust color, light crumb color, soft and moist texture, cohesion, and brightness. The bread with the highest percentage of overall consumer acceptance was 12.5% konjac with 93% and 96% acceptance among consumers and non-consumers of gluten-free bread, respectively.

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The current COVID-19 (SARS-CoV-2) pandemic has generated negative psychological effects on the global population. In this context, one of the most vulnerable groups is adolescents, who have faced a range of challenging scenarios. The consequences of this pandemic for the wellbeing of adolescents need to be researched across countries. From this perspective, this study aims to characterize the wellbeing of adolescents from Mexico and Chile during the pandemic and delve into the relationship between victimization and the hedonic and eudaimonic types of wellbeing. Data from adolescent students (n = 3,275) were used, with the support of the Global Research Alliance. Descriptive and regression analyses were conducted and their results indicated that: 1) Late adolescents scored lower on flourishing, and males scored higher than females. There was also a higher prevalence of languishing in late adolescents from both countries, as well as high levels of languishing in non-binary adolescents, especially in Chile; 2) There was a high prevalence of poly-victimization, with the highest percentage reported by females and the late adolescent group in both countries; 3) Non-victims had a higher probability of being in the flourishing group than victims in both countries; 4) Poly-victimization especially had an effect on the eudaimonic wellbeing of early adolescents and on the hedonic and eudaimonic wellbeing of late adolescents in both countries. Implications related to the mental health policies for adolescence are discussed in terms of how to increase adolescent wellbeing.

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The Hedonic Threshold Methodology (HTM), through the determination of compromised acceptance threshold (CAT) and hedonic rejection threshold (HRT), has several applications by the food industry. In order to further increase the field of application of HTM, the objective was to use a mixture design in the Hedonic Threshold Methodology, to enable the determination of hedonic thresholds (CAT and HRT) by varying the intensity of three stimuli simultaneously. It was investigated how much it is possible to replace the NaCl content (1.8% flour weight basis) with two other ingredients (KCL/yeast extract or KCL/enzyme preparation), without compromising the acceptance (CAT) and without resulting in sensory rejection (HRT) of crackers. Reduction in the acceptance started to occur by reducing the NaCl content by around 64% (from 1.81% to 0.651%), with the addition of 1.149% KCl. Two combinations of KCl and yeast extract (1.783% and 0.017%, or 0.693% and 1.107%, respectively) allowed producing a cracker with no NaCl without sensory rejection. The reduction in acceptance also started to occur by reducing the NaCl content by around 40% (from 1.81% to 1.086%), with adding of 0.358% KCl and 0.356% enzyme preparation. A sensory rejection begins to occur by reducing the NaCl content by around 99% (1.81-0.012%), with the addition of 1.215% KCl and 0.573% enzyme preparation (transglutaminase). The use of the mixture design in HTM allowed the unprecedented determination of hedonic thresholds varying three stimuli. This expands the possibilities for applications of sensory thresholds.

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The orexin peptides promote hedonic intake and other reward behaviors through different brain sites. The opioid dynorphin peptides are co-released with orexin peptides but block their effects on reward in the ventral tegmental area (VTA). We previously showed that in the paraventricular hypothalamic nucleus (PVN), dynorphin and not orexin peptides enhance hedonic intake, suggesting they have brain-site-specific effects. Obesity alters the expression of orexin and dynorphin receptors, but whether their expression across different brain sites is important to hedonic intake is unclear. We hypothesized that hedonic intake is regulated by orexin and dynorphin peptides in PVN and that hedonic intake in obesity correlates with expression of their receptors. Here we show that in mice, injection of DYN-A1-13 (an opioid dynorphin peptide) in the PVN enhanced hedonic intake, whereas in the VTA, injection of OXA (orexin-A, an orexin peptide) enhanced hedonic intake. In PVN, OXA blunted the increase in hedonic intake caused by DYN-A1-13. In PVN, injection of norBNI (opioid receptor antagonist) reduced hedonic intake but a subsequent OXA injection failed to increase hedonic intake, suggesting that OXA activity in PVN is not influenced by endogenous opioid activity. In the PVN, DYN-A1-13 increased the intake of the less-preferred food in a two-food choice task. In obese mice fed a cafeteria diet, orexin 1 receptor mRNA across brain sites involved in hedonic intake correlated with fat preference but not caloric intake. Together, these data support that orexin and dynorphin peptides regulate hedonic intake in an opposing manner with brain-site-specific effects.

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Excessive sodium consumption is a worldwide public health concern. The substitution of sodium chloride (NaCl) for potassium chloride (KCl) has been adopted to reduce the sodium concentration in processed foods. The challenge is to make this substitution without affecting the sensory acceptance of foods. In this context, the objective was to determine from which concentrations the replacement of NaCl by KCl results in reduced acceptance (compromised acceptance threshold - CAT) and begins the sensory rejection (hedonic rejection threshold - HRT) of cracker-type biscuits. Using the hedonic thresholds methodology (HTM) by varying a stimulus, CAT and HRT were determined for the concentration of NaCl in crackers and, by varying two stimuli, CAT and HRT, for replacing NaCl with KCl in crackers were determined. Without the addition of KCl, the reduction in acceptance started to occur by reducing the NaCl content by around 60% (from 1.81% to 0.73%); and sensory rejection began to appear by reducing the NaCl content by approximately 93% (1.81% to 0.13%). Reduction in the acceptance started to occur by lowering the NaCl content by around 78% (from 1.81% to 0.397%), with the addition of 0.896% KCl. In addition, by adding KCl, it was possible to reduce 100% NaCl without sensory rejection of the crackers. With these results, cracker industries can reduce the sodium content of their products, contributing to the reduction of population salt intake.

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A growing body of research conducted in general life settings has found positive associations between happiness and prosocial behavior. Unfortunately, equivalent studies in the workplace are lacking. Organizational citizenship behaviors (OCBs), the prosocial behaviors at work, have not been properly studied in relation to happiness, despite the positive consequences of both constructs for workers and companies. In response, our research aims to better understand this relationship from several angles. First, using a three-wave longitudinal design, we explored how OCBs and happiness are related to each other over time. Second, happiness was measured from a broad perspective, and three conceptualizations were adopted: the hedonic (e.g., positive affect and life satisfaction), the eudaimonic (e.g., relatedness and autonomy), and the flourishing (e.g., meaning and engagement) approaches. Thus, not only the prospective link between OCBs and happiness was tested, but it was also explored using the three models of happiness previously mentioned. Third, we conducted this longitudinal design in a less typical sample than previous research (i.e., Chile). We found results that supported our main hypotheses: (1) OCBs are prospective positive predictors of hedonic happiness, eudaimonic happiness, and flourishing; (2) the three models of happiness also prospectively predict OCBs. Our findings suggest that OCBs foster a broad range of happiness facets, which in turn fosters back the emergence of more OCBs, leading to a virtuous circle of prosociality and well-being in the workplace. This positive spiral benefits not only workers' quality of life, but also organizations' profitability and sustainability. Theoretical and applied implications for the field of Positive Organizational Psychology are discussed.

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In the Brazilian context, many plants have been marketed under the name of unconventional food plants (UFPs). However, it is not known whether this label causes some bias in product acceptance. Thus, two case studies were conducted to fill this gap. The research also sought to determine if the type of fair (agroecological vs. common) where the UFP is sold, the familiarity with the term, and the identification of a UFP when used as an ingredient act as moderating variables of this relationship. This paper presents data from two case studies. The first was conducted with jenipapo juice through sensory evaluations at a conventional fair and an agroecological fair in the metropolitan region of Maceió (Northeast Brazil). The product was offered to some attendees without giving them any information, while for other attendees, the presence of a UFP and the underlying concept were mentioned. In this context, the UFP label did not affect the sensory evaluation. In the second case study, taioba cakes were offered to students from a public university in the same city. In this context, the UFP-labelled product was less accepted than the product without the label only for students who had not heard of UFPs. The differences between the two case studies reinforce the need to expand research on this topic to identify in which contexts the UFP label influences sensory evaluations.

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BACKGROUND: Anacardium othonianum Rizzini is a native Cerrado fruit, recently described in the literature. Its use is restricted to its native region and there is a lack of studies regarding production of vinegar from the pulp. This work aims to investigate the production of A. othonianum Rizzini vinegar using submerged fermentation. RESULTS: The density, alcohol content, proximal composition, pH, color coordinates, and chromatographic profile of the volatile compounds were analyzed in the slurry, fermented juice, and vinegar produced from the corpulent parts of A. othonianum Rizz. Sensory acceptance and willingness to pay were also assessed with vinegar at 4% and 6% of total acidity. The results indicated compliance with European legislation and the presence of volatile compounds such as carbon dioxide, acetic acid, ethanol, and acetaldehyde in the analyzed vinegars. Our results indicate the potential of vinegar production from A. othonianum, with 74% and 86% willingness to pay. CONCLUSIONS: The process of transformation of the fruit pulp into new products can contribute to fruit valorization and consequent preservation of the plant in the Cerrado biome. To the best of our knowledge, this is the first report of volatile compounds and minerals in A. othonianum Rizz. slurry. Our observations can be used as a basis for future studies regarding the preparation of vinegars from this species and for investigating their application in cooking and guiding consumer perception. © 2020 Society of Chemical Industry.

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Obesity is a chronic recurring disease whose prevalence has almost tripled over the past 40 years. In individuals with obesity, there is significant increased risk of morbidity and mortality, along with decreased quality of life. Increased obesity prevalence results, at least partly, from the increased global food supply that provides ubiquitous access to tasty, energy-dense foods. These hedonic foods and the nonfood cues that through association become reward predictive cues activate brain appetitive control circuits that drive hyperphagia and weight gain by enhancing food-seeking, motivation, and reward. Behavioral therapy (diet and lifestyle modifications) is the recommended initial treatment for obesity, yet it often fails to achieve meaningful weight loss. Furthermore, those who lose weight regain it over time through biological regulation. The need to effectively treat the pathophysiology of obesity thus centers on biologically based approaches such as bariatric surgery and more recently developed drug therapies. This review highlights neurobiological aspects relevant to obesity causation and treatment by emphasizing the common aspects of the feeding-inhibitory effects of multiple signals. We focus on glucagon like peptide-1 receptor (GLP-1R) signaling as a promising obesity treatment target by discussing the activation of intestinal- and brain-derived GLP-1 and GLP-1R expressing central nervous system circuits resulting from normal eating, bariatric surgery, and GLP-1R agonist drug therapy. Given the increased availability of energy-dense foods and frequent encounters with cues that drive hyperphagia, this review also describes how bariatric surgery and GLP-1R agonist therapies influence food reward and the motivational drive to overeat.

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Throughout the animal kingdom sucrose is one of the most palatable and preferred tastants. From an evolutionary perspective, this is not surprising as it is a primary source of energy. However, its overconsumption can result in obesity and an associated cornucopia of maladies, including type 2 diabetes and cardiovascular disease. Here we describe three physiological levels of processing sucrose that are involved in the decision to ingest it: the tongue, gut, and brain. The first section describes the peripheral cellular and molecular mechanisms of sweet taste identification that project to higher brain centers. We argue that stimulation of the tongue with sucrose triggers the formation of three distinct pathways that convey sensory attributes about its quality, palatability, and intensity that results in a perception of sweet taste. We also discuss the coding of sucrose throughout the gustatory pathway. The second section reviews how sucrose, and other palatable foods, interact with the gut-brain axis either through the hepatoportal system and/or vagal pathways in a manner that encodes both the rewarding and of nutritional value of foods. The third section reviews the homeostatic, hedonic, and aversive brain circuits involved in the control of food intake. Finally, we discuss evidence that overconsumption of sugars (or high fat diets) blunts taste perception, the post-ingestive nutritional reward value, and the circuits that control feeding in a manner that can lead to the development of obesity.

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Beef imports in Chile have increase annually by close to 10% in the past 10 years, threatening the national industry. Understanding the importance of different attributes may help guide a strategy for the local beef industry. Thus, the goal of the study was to identify which attributes observable at the point of sale influence the beef buying process. The sample was a set of 406 price observations, search attributes (intrinsic and extrinsic cues), and credence attributes of differentiated beef. The study was conducted in 15 counties in the Metropolitana region in Chile, and the results indicated that among differentiated beef, the highest valued attributes were low fat and natural. In addition, Angus and Wagyu beef, breeds associated by consumers with increased tenderness and flavor, were highly valued. Finally, processed beef products (portioned, marinated, or seasoned) were more valued than unprocessed products. An important and unexpected result is that highlighting Chile as the country of origin is a negatively valued attribute.

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Previous studies suggest that older adults are living increasingly alone and without the company of their close relatives, which cause them depression problems and a detriment to their health and general wellbeing. The use of social network sites (SNS) allows them to reduce their isolation, improve their social participation, and increase their autonomy. Although the adoption of various information technologies by older adults has been studied, some assumptions still predominate, for example, that older adults use SNS only for utilitarian purposes. However, considering SNS as hedonic information systems, and in order to extend the theoretical explanation of the intention to use hedonic systems to their actual use, this study aims to determine the influence of perceived enjoyment, perceived usefulness, and perceived ease of use on the use of SNS by elders in Concepción, Chile. Two hundred fifty-three older adults participated in the cross-sectional study. The results indicate that perceived ease of use is the variable that has the greatest total effect in explaining the use of SNS and that by adding the perceived enjoyment construct, the explanatory power of the model increases significantly. Therefore, advancement in user acceptance models, especially in the use of SNS by elders, can be made by focusing on the type of system, hedonic or utilitarian.

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INTRODUCTION: Although the positive and negative affect scale proposed by Mroczek and Kolarz has not been as widely used as other instruments, the adequate psychometric properties reported and the simplicity of the application, make it an adequate instrument to measure the hedonic component of subjective well-being. Thus, the scale validation in Chile will allow researchers to have a short and reliable instrument available in order to measure subjective well-being. OBJECTIVE: The initial objective of this study was to in Chile the "Positive and negative affect scale" proposed by Mroczek and Kolarz. METHODS: A non-probabilistic sample of 155 Chileans and a sample of 308 adult immigrants residing in Chile from Colombia, Peru and Venezuela were recruited. The sample of Chileans was used to validate the scale. The construct validity (Cronbach's Alpha and exploratory factor analysis) and the concurrent validity through bivariate correlations with other measures were estimated. Finally, the differences in affect expression by Chileans in comparison with migrants’ people were evaluated. RESULTS: The reliability index was Alpha = 0.92 for the positive affect sub-scale and Alpha = 0.75 for the negative affect sub-scale. The exploratory factor analysis reproduced in the same way the factorial loadings proposed in the original instrument with saturations greater than 0.35 per item. Colombian and Venezuelan migrants show greater expression of positive affect than Chileans, while this difference is not observed when comparing Chileans with Peruvians. CONCLUSION: The positive and negative affect scale has adequate psychometric properties to measure the expression of affect (hedonic well-being) in the Chilean population.

INTRODUCCIÓN: Aunque la escala de afecto positivo y negativo propuesta por Mroczek y Kolarz no ha sido tan ampliamente utilizada como otros instrumentos, las adecuadas propiedades psicométricas publicadas hasta ahora, sumado a la rapidez de su aplicación; la sitúan como un instrumento adecuado para medir el componente hedónico del bienestar subjetivo. En este sentido, la validación de la escala en Chile permitirá a los investigadores tener a disposición un instrumento breve y fiable con el cual medir el bienestar subjetivo. OBJETIVO: El objetivo inicial de este estudio fue validar en Chile la escala de afecto positivo y negativo propuesta por Mroczek y Kolarz. MÉTODOS: Se reclutó a una muestra no probabilística de 155 chilenos junto con una muestra de 308 inmigrantes adultos residentes en Chile de nacionalidades colombiana, peruana y venezolana. La muestra de chilenos se utilizó para la validación de la escala. Se evaluó la validez de constructo (Alfa de Cronbach y análisis factorial exploratorio), y luego la validez concurrente a través de correlaciones bivariadas con la medida de “sentimiento de felicidad” de Wold (1995) y de “satisfacción con la vida” de Keyes, Shmotkin and Ryff (2002). Finalmente, se valoraron las diferencias en la expresión de afecto de los chilenos en comparación con la de los migrantes. RESULTADOS: El índice de fiabilidad fue de Alfa = 0,92 para la subescala de afecto positivo y de Alfa = 0,75 para la subescala de afecto negativo. El análisis factorial exploratorio reprodujo de manera idéntica las cargas factoriales propuestas en el instrumento original con saturaciones de los ítems mayor a 0,35 por factor. Los migrantes colombianos y venezolanos muestran mayor expresión de afecto positivo que los chilenos, mientras que esta diferencia no se observa al comparar chilenos con peruanos. CONCLUSIÓN: La escala de afecto positivo y negativo presenta propiedades psicométricas adecuadas para medir la expresión de afecto (bienestar hedónico) en la población chilena.

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Luxury brand marketers have recently turned their attention to customer-driven social media devoted to their brands. The key concepts of involvement, interaction and behavioral intention provide the theoretical foundation to investigate luxury brands. The purpose of this study is to test a model that analyzes the relationship among brand involvement, consumer-brand interaction and behavioral intention in the context of luxury brand-related activities on social media. Based on content value theory, the present research identifies the moderating role of utilitarian/hedonic motivations on the relationships proposed. Data were collected from 326 social media users who look for information on internet about luxury brands before purchasing a specific brand. We provide evidence indicating positive relationships between brand involvement, consumer-brand interaction and behavioral intention. The results also confirm the moderating role of the utilitarian/hedonic motivations. This study provides recommendations to luxury brands to understand the nature of consumer involvement and brand-customer relationship in order to forecast the behavioral intention of their consumers more accurately.

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