50 research outputs found

    Marketing as a means to transformative social conflict resolution: lessons from transitioning war economies and the Colombian coffee marketing system

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    Social conflicts are ubiquitous to the human condition and occur throughout markets, marketing processes, and marketing systems.When unchecked or unmitigated, social conflict can have devastating consequences for consumers, marketers, and societies, especially when conflict escalates to war. In this article, the authors offer a systemic analysis of the Colombian war economy, with its conflicted shadow and coping markets, to show how a growing network of fair-trade coffee actors has played a key role in transitioning the country’s war economy into a peace economy. They particularly draw attention to the sources of conflict in this market and highlight four transition mechanisms β€” i.e., empowerment, communication, community building and regulation β€” through which marketers can contribute to peacemaking and thus produce mutually beneficial outcomes for consumers and society. The article concludes with a discussion of implications for marketing theory, practice, and public policy

    Intraspecies Variation in the Emergence of Hyperinfectious Bacterial Strains in Nature

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    Salmonella is a principal health concern because of its endemic prevalence in food and water supplies, the rise in incidence of multi-drug resistant strains, and the emergence of new strains associated with increased disease severity. Insights into pathogen emergence have come from animal-passage studies wherein virulence is often increased during infection. However, these studies did not address the prospect that a select subset of strains undergo a pronounced increase in virulence during the infective process- a prospect that has significant implications for human and animal health. Our findings indicate that the capacity to become hypervirulent (100-fold decreased LD50) was much more evident in certain S. enterica strains than others. Hyperinfectious salmonellae were among the most virulent of this species; restricted to certain serotypes; and more capable of killing vaccinated animals. Such strains exhibited rapid (and rapidly reversible) switching to a less-virulent state accompanied by more competitive growth ex vivo that may contribute to maintenance in nature. The hypervirulent phenotype was associated with increased microbial pathogenicity (colonization; cytotoxin production; cytocidal activity), coupled with an altered innate immune cytokine response within infected cells (IFN-Ξ²; IL-1Ξ²; IL-6; IL-10). Gene expression analysis revealed that hyperinfectious strains display altered transcription of genes within the PhoP/PhoQ, PhoR/PhoB and ArgR regulons, conferring changes in the expression of classical virulence functions (e.g., SPI-1; SPI-2 effectors) and those involved in cellular physiology/metabolism (nutrient/acid stress). As hyperinfectious strains pose a potential risk to human and animal health, efforts toward mitigation of these potential food-borne contaminants may avert negative public health impacts and industry-associated losses

    The concurrent reinforcement of two interresponse times: absolute rate of reinforcement

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    Three pigeons obtained food on a one-key schedule of reinforcement for two concurrent, discriminated interresponse times. The overall rate of reinforcement was determined by a family of variable-interval schedules and by a continuous reinforcement schedule. The average frequency of reinforcement varied from 1.1 to 300 reinforcements per hour; the relative frequency of reinforcement for each of the two interresponse times was 0.5 throughout the experiment. The number of responses per minute increased sharply as the number of reinforcements per hour increased from 1 to 20. Beyond 30 reinforcements per hour, the curve was approximately flat, although it sometimes decreased slightly at the highest reinforcement rates. The relative frequency of the shorter interresponse time also increased sharply as the number of reinforcements per hour increased from 1 to 20. The asymptote of the relative frequency function approximately equalled the relative reciprocal of the length of the shorter interresponse time for reinforcement rates greater than 30 or 40 reinforcements per hour. This approximation was obscured by the response-rate function

    The reinforcement of four interresponse times in a two-alternative situation

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    Pigeons pecked for food in a two-key procedure. A concurrent variable-interval variable-interval schedule of reinforcement for two classes of interresponse times was arranged on each key. A visual stimulus set the occasion for potential reinforcement of the four operant classes: shorter and longer interresponse times on left and right keys. In Exp. I, the relative frequency of respones on a key equalled the relative frequency of reinforcement on that key. In Exp. II, the relative frequency of an interresponse time equalled the relative reciprocal of its length. In Exp. III, the relative frequency of an interresponse time was a monotonically increasing function of its relative frequency of reinforcement. These functions relating the relative frequency of an interresponse time to its relative length and to its relative frequency of reinforcement were the same as if there had been no second key. Also, the distribution of responses between keys was independent of the relative frequency of an interresponse time on either key. Experiment IV replicated Exp. I except that choices between keys were controlled by a stimulus that signalled the availability of reinforcement on the right key. A comparison of Exp. I and IV suggested that the relative frequency of an interresponse time on one key generally was independent of behavior on the other key, but that the number of responses per minute on a key did depend on behavior on the other key

    The concurrent reinforcement of two interresponse times: the relative frequency of an interresponse time equals its relative harmonic length

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    The relative lengths of two concurrently reinforced interresponse times were varied in an experiment in which three pigeons obtained food by pecking on a single key. Visual discriminative stimuli accompanied the two time intervals in which reinforcements were scheduled according to a one-minute variable-interval. The steady-state relative frequency of an interresponse time approximately equalled the complement of its relative length, that is, its relative harmonic length. Thus, lengths of interresponse times and delays of reinforcement have the same effect on the relative frequencies of interresponse times and choices in one-key and two-key concurrent variable-interval schedules, respectively. A second experiment generalized further the functional equivalence between the effects of these one-key and two-key concurrent schedules by revealing that the usual matching-to-relative-immediacy in two-key concurrent schedules is undisturbed if reinforcement depends upon the occurrence of a response at the end of the delay interval, as it does in the one-key schedules. The results of both experiments are consistent with a quantitative theory of concurrent operant behavior

    Choice between response rates

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    Three pigeons were required to peck a single key at a higher and a lower rate, corresponding to two classes of shorter and longer concurrently reinforced interresponse times. Food reinforcers arranged by a single variable-interval schedule were randomly allocated to the two reinforced interresponse times. The absolute durations of reinforced interresponse times were varied while the total reinforcements per hour was held constant and the relative duration, i.e., the relative reciprocal, of the shorter reinforcer class was held constant at 0.70. Preference for the higher rate of responding, as measured by the relative frequency of responses terminating interresponse times in the shorter reinforced class, depended on the absolute reinforced response rates. Preference for the higher reinforced rate increased from a level of near-indifference (0.50) at high reinforced response rates, through the matching level (0.70) at intermediate reinforced response rates, to a virtually exclusive preference (>0.90) at low reinforced response rates. These results resemble corresponding preference functions obtained with two-key concurrent-chains schedules and thereby provide another sense in which it may be said that interresponse-time distributions from interval schedules estimate preference functions for the component response rates corresponding to different classes of reinforced interresponse times

    Two-key concurrent paced variable-interval paced variable-interval schedules of reinforcement

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    Nine pigeons were used in two experiments in which a response was reinforced if a variable-interval schedule had assigned a reinforcement and if the response terminated an interresponse time within a certain interval, or class, of interresponse times. One such class was scheduled on one key, and a second class was scheduled on a second key. The procedure was, therefore, a two-key concurrent paced variable-interval paced variable-interval schedule. In Exp. I, the lengths of the two reinforced interresponse times were varied. The relative frequency of responding on a key approximately equalled the relative reciprocal of the length of the interresponse time reinforced on that key. In Exp. II, the relative frequency and relative magnitude of reinforcement were varied. The relative frequency of responding on the key for which the shorter interresponse time was reinforced was a monotonically increasing, negatively accelerated function of the relative frequency of reinforcement on that key. The relative frequency of responding depended on the relative magnitude of reinforcement in approximately the same way as it depended on the relative frequency of reinforcement. The relative frequency of responding on the key for which the shorter interresponse time was reinforced depended on the lengths of the two reinforced interresponse times and on the relative frequency and relative magnitude of reinforcement in the same way as the relative frequency of the shorter interresponse time depended on these variables in previous one-key concurrent schedules of reinforcement for two interresponse times
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