445 research outputs found

    Exposure to food insecurity increases energy storage and reduces somatic maintenance in European starlings (Sturnus vulgaris)

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    Birds exposed to food insecurity—defined as temporally variable access to food—respond adaptively by storing more energy. To do this, they may reduce energy allocation to other functions such as somatic maintenance and repair. To investigate this trade-off, we exposed juvenile European starlings (Sturnus vulgaris, n = 69) to 19 weeks of either uninterrupted food availability or a regime where food was unpredictably unavailable for a 5-h period on 5 days each week. Our measures of energy storage were mass and fat scores. Our measures of somatic maintenance were the growth rate of a plucked feather, and erythrocyte telomere length (TL), measured by analysis of the terminal restriction fragment. The insecure birds were heavier than the controls, by an amount that varied over time. They also had higher fat scores. We found no evidence that they consumed more food overall, though our food consumption data were incomplete. Plucked feathers regrew more slowly in the insecure birds. TL was reduced in the insecure birds, specifically, in the longer percentiles of the within-individual TL distribution. We conclude that increased energy storage in response to food insecurity is achieved at the expense of investment in somatic maintenance and repair

    Going back to basics in design science: from the information technology artifact to the information systems artifact

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    The concept of the “IT artifact” plays a central role in the information systems research community’s discourse on design science. We pose the alternative concept of the “IS artifact,” unpacking what has been called the IT artifact into a separate “information artifact,” “technology artifact,” and “social artifact.” Technology artifacts (such as hardware and software), information artifacts (such as a message), and social artifacts (such as a charitable act) are different kinds of artifacts that together interact in order to form the IS artifact. We illustrate the knowledge value of the IS artifact concept with material from three cases. The result is to restore the idea that the study of design in information systems needs to attend to the design of the entire IS artifact, not just the IT artifact. This result encourages an expansion in the use of design science research methodology to study broader kinds of artifacts

    Learning capability : the effect of existing knowledge on learning

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    It has been observed that different people learn the same things in different ways - increasing their knowledge of the subject/domain uniquely. One plausible reason for this disparity in learning is the difference in the existing personal knowledge held in the particular area in which the knowledge increase happens. To understand this further, in this paper knowledge is modelled as a 'system of cognitive schemata', and knowledge increase as a process in this system; the effect of existing personal knowledge on knowledge increase is 'the Learning Capability'. Learning Capability is obtained in form of a function; although it is merely a representation making use of mathematical symbolism, not a calculable entity. The examination of the function tells us about the nature of learning capability. However, existing knowledge is only one factor affecting knowledge increase and thus one component of a more general model, which might additionally include talent, learning willingness, and attention
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