Publications by authors named "Andrea Friedrich"

Terminal olefins are important platform chemicals, drop-in compatible hydrocarbons and also play an important role as biocontrol agents of plant pathogens. Currently, 1-alkenes are derived from petroleum, although microbial biosynthetic routes are known. Jeotgalicoccus sp.

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We examined the extent to which nonhedonically different differential outcomes involving feeder location control pigeons' comparison choices in matching to sample. In Experiment 1, we showed that differential feeder location outcomes associated with each of two samples can facilitate delayed-matching accuracy. In Experiment 2, we found positive transfer following training on two matching tasks with differential feeder location outcomes when samples from one task were replaced by samples from the other task.

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In a conditional discrimination each of two sample stimuli indicates which of two comparison stimuli is correct. When correct choice following each conditional stimulus is followed by a different outcome (one kind of food following one, a different kind of food following the other) it often facilitates acquisition and improves memory. In transfer designs, in which two different conditional discriminations are followed by the same two differential outcomes, outcome expectation can be shown to be sufficient for comparison choice.

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When differential outcomes follow correct responses to each of two comparison stimuli in matching to sample, relative to the appropriate control condition, higher matching accuracy is typically found, especially when there is a delay between the sample and the comparison stimuli. In two experiments, we examined whether this differential-outcomes effect depends on using outcomes that differ in hedonic value (e.g.

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There is evidence that how humans perceive time is affected by the activity in which they are engaged when they are judging time. In humans, typically, the more demanding the task, the faster time seems to pass. We asked whether a similar effect could be found in pigeons.

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The feasibility of oxygen transfer rate (OTR) measurement to non-destructively monitor plant propagation and vitality of photosynthetically active plant in vitro culture of duckweed (Wolffia australiana, Lemnaceae) was tested using Respiration Activity Monitoring System (RAMOS). As a result, OTR proofed to be a sensitive indicator for plant vitality. The culture characterization under day/night light conditions, however, revealed a complex interaction between oxygen production and consumption, rendering OTR measurement an unsuitable tool to track plant propagation.

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Absolute pitch (AP) is the ability to classify individual pitches without an external referent. The authors compared results from pigeons (Columba livia, a nonsongbird species) with results (R. Weisman, M.

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Clement, Feltus, Kaiser, and Zentall (2000) found that when pigeons have to work to obtain a discriminative stimulus that is followed by reinforcement, they prefer a discriminative stimulus that requires greater effort over one that requires less effort. The authors suggested that such a preference results from the greater change in hedonic value that occurs between the more aversive event and the onset of the stimulus that signals reinforcement, a contrast effect. It was hypothesized that any stimulus that follows a relatively more aversive event would be preferred over a stimulus that follows a relatively less aversive event.

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Clement, Feltus, Kaiser, and Zentall (2000) reported that pigeons prefer discriminative stimuli that require greater effort (more pecks) to obtain over those that require less effort. In the present experiment, we examined two variables associated with this phenomenon. First, we asked whether delay of reinforcement, presumably a relatively aversive event similar to effort, would produce similar effects.

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Although animals typically prefer to exert less effort rather than more effort to obtain food, the present research shows that requiring greater effort to obtain food at a particular location appears to increase the value of that location. In Experiment 1, pigeons' initial preference for one feeder was significantly reduced by requiring 1 peck to obtain food from that feeder and requiring 30 pecks to obtain food from the other feeder. In Experiment 2, a similar decrease in preference was not found when pigeons received reinforcement from both feeders independently of the amount of effort required.

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Research suggests that animals are capable of forming functional equivalence relations or stimulus classes of the kind usually demonstrated by humans (e.g., the class defined by an object and the word for that object).

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Three experiments attempted to replicate Manabe, Kawashima, and Staddon's (1995) finding of emergent differential sample behavior in budgerigars that has been interpreted as evidence of functional equivalence class formation. In Experiments 1 and 2, pigeons initially learned two-sample/ two-alternative matching to sample in which comparison presentation was contingent on pecking one sample on a differential-reinforcement-of-low-rate (DRL) schedule and the other on a fixed-ratio (FR) schedule. Later, two new samples were added to the task.

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