Aversion Analysis

In this paper : a) the consumer’s problem is studied over two periods, the second one involving S states, and the consumer being endowed with S+1 incomes and having access to N financial assets; b) the consumer is then representable by a continuously differentiable system of demands, commodity demands, asset demands and desirabilities of incomes (the S+1 Lagrange multiplier of the S+1 constraints); c) the multipliers can be transformed into subjective Arrow prices; d) the effects of the various incomes on these Arrow prices decompose into a compensation effect (an Antonelli matrix) and a wealth effect; e) the Antonelli matrix has rank S-N, the dimension of incompleteness, if the consumer can financially adjust himself when facing income shocks; f) the matrix has rank S, if not; g) in the first case, the matrix represents a residual aversion; in the second case, a fundamental aversion; the difference between them is an aversion to illiquidity; this last relation corresponds to the Drèze-Modigliani decomposition (1972); h) the fundamental aversion decomposes also into an aversion to impatience and a risk aversion; i) the above decompositions span a third decomposition; if there exists a sure asset (to be defined, the usual definition being too specific), the fundamental aversion admits a three-component decomposition, an aversion to impatience, a residual aversion and an aversion to the illiquidity of risky assets; j) the formulas of the corresponding financial premiums are also presented.

Effets motivationnels des cannabinoïdes dans un modèle animal de la schizophrénie

Depuis quelques décennies, la consommation de cannabis et son usage thérapeutique sont le sujet de nombreux débats. Le cannabis est la drogue illicite la plus consommée au monde et cette consommation se trouve dix fois plus élevée chez les patients atteints de schizophrénie que dans la population générale. L’hypothèse d’une automédication initialement proposée afin d’expliquer la consommation élevée de cannabis chez les patients atteints de schizophrénie est maintenant remise en question. En effet, les rapports indiquant une aggravation des symptômes plutôt qu’une amélioration suite à une consommation à long terme sont de plus en plus nombreux. Sachant que le cannabis peut induire des effets soit plaisants soit aversifs, la question se pose à savoir si une prédominance de la valence motivationnelle positive ou une diminution de la valence négative du cannabis peut expliquer la consommation élevée parmi les individus ayant un diagnostic de schizophrénie? Bien qu’un grand nombre de recherches pré-cliniques aient été menées chez l’animal normal pour évaluer l’effet motivationnel du Δ9-tétrahydrocannabinol (THC) et autres cannabinoïdes synthétiques, aucune n’a abordé cette problématique dans un modèle animal de la schizophrénie. Cette lacune nous a donc amené à étudier la valence motivationnelle du THC et de l’agoniste cannabinoïde WIN55,212-2 (WIN) dans un modèle animal de la schizophrénie: la lésion néonatale de l’hippocampe ventral (NVHL). Dans le premier article, nous présentons les résultats de quatre expériences. Une première avait pour objectif de déterminer si la procédure expérimentale que nous avons utilisée permettait de reproduire des signes distinctifs du modèle animal de la schizophrénie. Par la suite, nous avons évalué i) l’effet d’une dose de WIN sur l’activité locomotrice spontanée et ii) la valence motivationnelle du THC (0.5 mg/kg, i.p) et du WIN (1 mg/kg, i.p) chez les rats adolescents (jour post-natal 28-40, PD28-40) et adultes (PD56) au moyen du paradigme de préférence de place conditionnée (PPC). Tel qu’attendu, la réponse locomotrice à l’amphétamine (0.75 et 1.5 mg/kg) chez les rats NVHL adultes était supérieure à celle des rats contrôles (test distinctif du modèle). Le THC a induit une tendance aversive chez les rats contrôles adultes. Enfin, le WIN a stimulé l’activité locomotrice et induit une aversion significative chez les rats adultes NVHL. Dans un deuxième article, nous avons évalué la valence motivationnelle du THC (0.5 mg/kg), du WIN (1 et 3 mg/kg) et l’effet de l’amphétamine au moyen du paradigme d’autostimulation électrique intracérébrale (ASI). Les résultats montrent que : i) l’effet amplificateur de l’amphétamine sur l’ASI était de plus courte durée chez les rats NVHL; ii) le THC produit une légère atténuation de la récompense chez les rats contrôles tandis que le WIN a produit une atténuation plus prononcée de la récompense chez les rats NVHL, un effet qui a été bloqué par l’antagoniste aux récepteurs CB1, le AM251 (3 mg/kg). Pour la première fois les résultats suggèrent une altération du système endocannabinoïde dans un modèle animal de la schizophrénie. Ils indiquent qu’une exposition aigüe conduit à une prédominance de la valence négative. Bien qu’en apparente contradiction avec les études cliniques, ces résultats soulignent l’importance du contexte socio-environnemental pour expliquer les effets du cannabis chez les patients. De plus ils encouragent les futures études à évaluer cette valence sur un modèle d’exposition chronique.

Effect of dietary sodium restriction on taste perception of sodium chloride

The effect of dietary sodium restriction on perceived intensity of and preference for the taste of salt was evaluated in 76 adults, 25-49 years, with diastolic blood pressure between 79-90 mmHg. Participants were volunteers from clinical Hypertension Prevention Trials (HPT), at the University of California, Davis and the University of Minnesota, Minneapolis. Participants followed one of four HPT diets: 1600 mg Na+/day (NA, n=lS), 1600 mg Na+ plus 3200 mg K+/day (NK, n=lS), 1600 mg Na+/day plus energy restriction to achieve weight loss (NW, n=l3) and weight loss only (WT, n=l3). All participants attended regularly scheduled nutri­tion intervention meetings designed to help them achieve the HPT dietary goals. A fifth, no-intervention group, consisted of 20, no-diet-change controls CCN). Sodium, potassium and energy intakes were monitored by analysis of single, 24-hour food records and corresponding overnight urine speci­mens, obtained at baseline and after 12 and 24 weeks of intervention. Hedonic responses to sodium chloride in a prepared cream of green bean soup were assessed by two methods : 1) scaling of like/dislike for an NaCl concentration series on 10-cm graphie line scales and 2) ad libitum mixing of unsalted and salted soups to maximum level of liking. Salt content of the mixes was analyzed by sodium ion-selective electrode. The concentration series was also rated for perceived saltiness­intensity on similar graphie line scales. Tests were conducted at base­line and after approximately 1, 3, 6, 8, 10, 13 and 24 weeks of intervention. Reduction in sodium intake and excretion in NA, NK and NW partici­pants was accompanied by a shift in preference toward less saltiness in soup. The pattern of hedonic responses changed over time: scores for high NaCl concentrations decreased progressively while scores for low concentrations increased. Hedonic maxima shifted fran a concentration of 0.55% at the onset to 0.1-0.2% added NaCl at week 24. During the same time period, the preferred concentration of ad libitum mixes declined 50%. These shifts occurred independently of changes in salti­ness intensity ratings, potassium or energy intakes, and were consistent across the two participating study sites. Like/dislike and sd. libitum responses were similar after 13 and 24 weeks of diet, as were measures of sodium intake and excretion. These findings suggest that after three months of sodium restriction, preference for salt had readjusted to a lower level, reflective of lower sodium intake. Mechanisms underlying the change in preference are unclear, but may include sensory, context, physiological as well as behavioral effects. In contrast, few changes were noted within WT and CN groups. The pattern of hedonic responses varied little in controls while the WT group showed increased liking for mid-range NaCl concentrations. Small, but significant fluctuations in ad libitum mix concentration occurred in both of these groups, but the differences appeared to be random rather than systematic. The results of this study indicate that preference for the taste of salt declines progressively toward a new baseline following reductions in sodium intake. These alterations may enhance maintenance of low­sodium diets for the treatment and prevention of hypertension. Further investigation is needed to establish the degree to which long-term com­pliance is contingent upon variation in salt taste preference.

Risk Aversion in Inventory Management

Traditional inventory models focus on risk-neutral decision makers, i.e., characterizing replenishment strategies that maximize expected total profit, or equivalently, minimize expected total cost over a planning horizon. In this paper, we propose a framework for incorporating risk aversion in multi-period inventory models as well as multi-period models that coordinate inventory and pricing strategies. In each case, we characterize the optimal policy for various measures of risk that have been commonly used in the finance literature. In particular, we show that the structure of the optimal policy for a decision maker with exponential utility functions is almost identical to the structure of the optimal risk-neutral inventory (and pricing) policies. Computational results demonstrate the importance of this approach not only to risk-averse decision makers, but also to risk-neutral decision makers with limited information on the demand distribution.

Corticosterone plasma concentrations in Carioca High- and Low-Conditioned freezing rats after a fear conditioned task

Our group in the Psychology Department at Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio) developed a rat genetic model of extreme freezing in response to contextual cues in an experimental chamber previously associated with footshock. One of the lines, Carioca High Freezing (CHF), exhibits an enhanced conditioned freezing response, whereas the other line, Carioca Low Freezing (CLF), shows the opposite response. The present study investigated corticosterone concentration between these two lines of animals and a random (RND) line of rats both under basal conditions and test condition after an emotional challenge using a contextual fear conditioning protocol. Comparisons between basal and test plasma corticosterone concentrations suggested differential basal and fear-induced differences between the two lines. The differences between basal conditions is an important and relevant aspect to be considered in behavioral experiments using or assessing stress and could help to understand variability in naïve populations.

Repostería Mint S.A.S

Mint es una repostería especializada para personas con problemas como diabetes y obesidad, que estará ubicada en localidades de Bogotá, donde existen mayores índices de este problema, inicialmente estaremos en Kennedy, una localidad con mayor población que padece la diabetes y obesidad en niños y adultos mayores. Mint busca cambiar el concepto de comida saludable o especializada en diabéticos, de aburrida, de mal sabor y poco agradable al consumo, por gran variedad de sabores, texturas y diseños. Este concepto se cambiará principalmente, a través del diseño de los productos, así como la decoración de la tienda, dado que estamos ubicados en estratos 2, 3 y 4, nuestros productos estarán condicionados al poder adquisitivo de nuestros consumidores. El local tendrá un área total de 87,4 m cuadrado, donde predomina el color y el diseño, funcionará de domingo a domingo en un horario de 10 am a 8 pm. La idea no solo es la venta de productos, sino realizar una concientización del cliente de lo más importante, su salud. La inversión estimada en maquinaria será de 6.510.000, equipo de 3.200.000 y los muebles enseres de 6.500.000, adicional, los costos operacionales mensuales estimados son de 15.473.400, donde el punto de equilibrio se logrará en el momento de venta de 467. 465.004. El local proporcionará diferentes campañas de fidelización, tales como promociones y descuentos, así como la posibilidad de pedir domicilios a través de internet.

Business cycle asymmetries: Loss aversion, sticky prices, and wages

In this chapter, the Smets-Wouters (2003) New Kenesian model is reformulated by introducing the loss aversion utility function developed in chapter two. The purpose of this is to understand how asymmetric real business cycles are linked to asymmetric behavior of agents in a price and wage rigidities set up. The simulations of the model reveal not only that the loss aversion in consumption and leisure is a good mechanism channel for explaining business cycle asymmetries, but also is a good mechanism channel for explaining asymmetric adjustment of prices and wages. Therefore the existence of asymmetries in Phillips Curve. Moreover, loss aversion makes downward rigidities in prices and wages stronger and also reproduces a more severe and persistent fall of the employment. All in all, this model generates asymmetrical real business cycles, asymmetric price and wage adjustment as well as hysteresis.

A DSGE model with loss aversion in consumption and leisure: an explanation for business cycles asymmetries

In this chapter, an asymmetric DSGE model is built in order to account for asymmetries in business cycles. One of the most important contributions of this work is the construction of a general utility function which nests loss aversion, risk aversion and habits formation by means of a smooth transition function. The main idea behind this asymmetric utility function is that under recession the agents over-smooth consumption and leisure choices in order to prevent a huge deviation of them from the reference level of the utility; while under boom, the agents simply smooth consumption and leisure, but trying to be as far as possible from the reference level of utility. The simulations of this model by means of Perturbations Method show that it is possible to reproduce asymmetrical business cycles where recession (on shock) are stronger than booms and booms are more long-lasting than recession. One additional and unexpected result is a downward stickiness displayed by real wages. As a consequence of this, there is a more persistent fall in employment in recession than in boom. Thus, the model reproduces not only asymmetrical business cycles but also real stickiness and hysteresis.

Does uncertainty cause inertia in decision making? An experimental study of the role of regret aversion and indecisiveness

Previous research has shown that often there is clear inertia in individual decision making---that is, a tendency for decision makers to choose a status quo option. I conduct a laboratory experiment to investigate two potential determinants of inertia in uncertain environments: (i) regret aversion and (ii) ambiguity-driven indecisiveness. I use a between-subjects design with varying conditions to identify the effects of these two mechanisms on choice behavior. In each condition, participants choose between two simple real gambles, one of which is the status quo option. I find that inertia is quite large and that both mechanisms are equally important.

Investigating age related changes in taste and affects on sensory perceptions of oral nutritional supplements

Background: sip feeds are oral nutritional supplements (ONSs) that are commonly prescribed to malnourished patients to improve their nutritional and clinical status. However, ONSs are poorly consumed and frequently wasted, with sweetness being identified as one of the factors leading to patients’ dislike of ONSs. Objectives: to investigate if age affects sweetness thresholds and if this impacts upon perceived sweetness intensity, hedonic (sweetness and overall) and ranked preference of ONS products. Design: prospective, observational. Subjects: thirty-six young adults (18–33 years) and 48 healthy older adults (63–85 years). Setting: Department of Food and Nutritional Sciences and the Clinical Health Sciences at the University of Reading. Methods: detection and recognition threshold levels, basic taste identification and ‘just about right’ level of sweetness were examined. Three ONSs (chocolate, vanilla, strawberry) and sucrose solutions were evaluated for hedonic sweetness, overall hedonic liking, sweetness intensity and rank preference. Results: significant differences were found in both sweetness detection and recognition thresholds (P = 0.0001) between young and older adults, with older adults more likely to incorrectly identify the taste (P = 0.0001). Despite the deterioration in sweetness sensitivity among the older adults, there were no significant differences found in sweetness intensity perceived for the ONS products presented (P > 0.05) when compared with the young adults. However, across both groups sweetness intensity was found to be correlated with overall product dislike across all flavour variants tested (R = 0.398, P = 0.0001). Conclusions: sweetness appears to be one of many factors contributing to the dislike of ONSs. Manufacturers are encouraged to reconsider the formulations of these products so that beneficial effects of ONSs can be delivered in a more palatable and acceptable form and wastage reduced.

Monatin and its stereoisomers: chemoenzymatic synthesis and taste properties

The sweet natural compound monatin 1 has two stereogenic centres and the (2S,4S) absolute configuration has been attributed to the natural isomer. We obtained all four stereoisomers as pure compounds by a six-step synthetic sequence. The stereogenic centre at C-4 was introduced stereoselectively by a regio- and enantiospecific enzymatic hydrolysis of the racemic ethyl dicarboxylate 4 using a protease from Aspergillus oryzae. The absolute configuration of the intermediate products was assigned by X-ray diffraction of chiral derivatives. The stereogenic centre at C-2 was introduced non-specifically, and the resulting diastereomeric mixtures were separated by RP-HPLC. The absolute configurations of the final products were established by comparing retention times on a chiral HPLC column with those of known samples. The four stereoisomers were submitted to tasting trials and three of them, particularly the (2R,4R) isomer, were found to be intensely sweet. A sample of natural monatin analysed under the same conditions is shown to contain all the four stereoisomers. The relative stereoisomeric content in the plant, as well as the possible isomerisation of the chiral centres during extraction and manipulation of monatin samples, are important points that need to be clarified by extensive analysis of the natural extracts. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).

Synthesis of heterosulfamates. Search for structure-taste relationships

Thirty one new sodium heterosulfamates, RNHSO3Na, where the R portion contains mainly thiazole, benzothiazole, thiadiazole and pyridine ring structures, have been synthesized and their taste portfolios have been assessed. A database of 132 heterosulfamates ( both open-chain and cyclic) has been formed by combining these new compounds with an existing set of 101 heterosulfamates which were previously synthesized and for which taste data are available. Simple descriptors have been obtained using (i) measurements with Corey-Pauling-Koltun (CPK) space- filling models giving x, y and z dimensions and a volume VCPK, (ii) calculated first order molecular connectivities ((1)chi(v)) and (iii) the calculated Spartan program parameters to obtain HOMO, LUMO energies, the solvation energy E-solv and V-SPART AN. The techniques of linear (LDA) and quadratic (QDA) discriminant analysis and Tree analysis have then been employed to develop structure-taste relationships (SARs) that classify the sweet (S) and non-sweet (N) compounds into separate categories. In the LDA analysis 70% of the compounds were correctly classified ( this compares with 65% when the smaller data set of 101 compounds was used) and in the QDA analysis 68% were correctly classified ( compared to 80% previously). TheTree analysis correctly classified 81% ( compared to 86% previously). An alternative Tree analysis derived using the Cerius2 program and a set of physicochemical descriptors correctly classified only 54% of the compounds.

Differences in glutamic acid and 5'-ribonucleotide contents between flesh and pulp of tomatoes and the relationship with umami taste

A difference in taste characteristics between the outer flesh and the inner pulp of tomatoes has been observed; in particular the pulp, which contains the seeds, had more umami taste. Analysis of the free amino acids and 5 '-ribonucleotides in the different parts of 13 varieties of tomatoes showed that in all cases the pulp contained higher levels of glutamic acid, 5 '-adenosine monophosphate (AMP), 5 '-guanosine monophosphate, 5 '-uridine monophosphate, and 5 '-cytidine monophosphate. The mean concentration of glutamic acid in the flesh was 1.26 g/kg and that in the pulp 4.56 g/kg but in some varieties the difference between pulp and flesh was more than 6-fold. For AMP, the mean concentration in the flesh was 80 mg/kg and that in the pulp was 295 mg/kg with one variety showing an 11-fold difference between pulp and flesh. These differences in concentration of these compounds, which are known to possess umami characteristics, provide an explanation for the perceived difference in umami taste between the flesh and pulp of tomatoes.