The concept of strong and weak virtual reality

We approach the virtual reality phenomenon by studying its relationship to set theory, and we investigate the case where this is done using the wellfoundedness property of sets. Our hypothesis is that non-wellfounded sets (hypersets) give rise to a different quality of virtual reality than do familiar wellfounded sets. We initially provide an alternative approach to virtual reality based on Sommerhoff's idea of first and second order self-awareness; both categories of self-awareness are considered as necessary conditions for consciousness in terms of higher cognitive functions. We then introduce a representation of first and second order self-awareness through sets, and assume that these sets, which we call events, originally form a collection of wellfounded sets. Strong virtual reality characterizes virtual reality environments which have the limited capacity to create only events associated with wellfounded sets. In contrast, the more general concept of weak virtual reality characterizes collections of virtual reality mediated events altogether forming an entirety larger than any collection of wellfounded sets. By giving reference to Aczel's hyperset theory we indicate that this definition is not empty, because hypersets encompass wellfounded sets already. Moreover, we argue that weak virtual reality could be realized in human history through continued progress in computer technology. Finally, we reformulate our characterization into a more general framework, and use Baltag's Structural Theory of Sets (STS) to show that within this general hyperset theory Sommerhoff's first and second order self-awareness as well as both concepts of virtual reality admit a consistent mathematical representation.Comment: 17 pages; several edits in v

Differential effect of tannic acid on two tree-feeding Lepidoptera: implications for theories of plant anti-herbivore chemistry

Feeding efficiencies of ultimate instar larvae of two polyphagous tree-feeding Lepidoptera, Malacosoma disstria (Lasiocampidae) and Orgyia leucostigma (Liparidae), were measured on artificial diets containing from 0% to 8% tannic acid. Relative growth rate (RGR) of O. leucostigma was not affected by up to 8% tannic acid, suggesting that O. leucostigma has evolved an effective counteradaptation to hydrolyzable tannins. In contrast, as little as 0.5% tannic acid caused a significant reduction in RGR of M. disstria , due both to reduced efficiency of conversion of digested food (ECD) and reduced relative consumption rate (RCR), and caused a significant increase in mortality during the pupal stage. Moreover, when reared from hatching on tannin-containing diets, no M. disstria larvae survived past the fourth instar.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47780/1/442_2004_Article_BF00380074.pd

Surfactants: their role in preventing the precipitation of proteins by tannins in insect guts

Much more tannic acid or pin oak tannin is required to precipitate the abundant leaf protein, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPC), from Manduca sexta gut fluid adjusted to pH 6.5 than is required to precipitate this protein from an aqueous buffer at the same pH. This finding demonstrates that some characteristic of M. sexta gut fluid, in addition to its basicity, counteracts the potential of tannins to precipitate ingested proteins. Gut fluid of M. sexta has a surface tension of 36–39 dynes/cm, indicating the presence of surfactants. Lysolecithin and linoleoylglycine, surfactants known to be present in insect gut fluids, also interfere with the precipitation of RuBPC by tannins at pH 6.5. It is concluded that detergency is a widespread property of insect gut fluids that counteracts the potential of tannins to precipitate die ary proteins, and it is argued that there is no longer any justification for continuing to refer to tannins as digestibility-reducing-substances. Finding that there has been no formidable barrier to the evolution of mechanisms that counter a generalized antidigestive action by tannins is difficult to reconcile with the idea that reduced digestibility is an evolved anti-herbivore adaptation of apparent plants.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47751/1/442_2004_Article_BF00379632.pd

The Tri-Trophic Interactions Hypothesis: Interactive Effects of Host Plant Quality, Diet Breadth and Natural Enemies on Herbivores

Several influential hypotheses in plant-herbivore and herbivore-predator interactions consider the interactive effects of plant quality, herbivore diet breadth, and predation on herbivore performance. Yet individually and collectively, these hypotheses fail to address the simultaneous influence of all three factors. Here we review existing hypotheses, and propose the tri-trophic interactions (TTI) hypothesis to consolidate and integrate their predictions. The TTI hypothesis predicts that dietary specialist herbivores (as compared to generalists) should escape predators and be competitively dominant due to faster growth rates, and that such differences should be greater on low quality (as compared to high quality) host plants. To provide a preliminary test of these predictions, we conducted an empirical study comparing the effects of plant (Baccharis salicifolia) quality and predators between a specialist (Uroleucon macolai) and a generalist (Aphis gossypii) aphid herbivore. Consistent with predictions, these three factors interactively determine herbivore performance in ways not addressed by existing hypotheses. Compared to the specialist, the generalist was less fecund, competitively inferior, and more sensitive to low plant quality. Correspondingly, predator effects were contingent upon plant quality only for the generalist. Contrary to predictions, predator effects were weaker for the generalist and on low-quality plants, likely due to density-dependent benefits provided to the generalist by mutualist ants. Because the TTI hypothesis predicts the superior performance of specialists, mutualist ants may be critical to A. gossypii persistence under competition from U. macolai. In summary, the integrative nature of the TTI hypothesis offers novel insight into the determinants of plant-herbivore and herbivore-predator interactions and the coexistence of specialist and generalist herbivores

Buttons, Handles, and Keys: Advances in Continuous-Control Keyboard Instruments

This is the peer reviewed version of the following article: Buttons, Handles, and Keys: Advances in Continuous-Control Keyboard Instruments, which has been published in final form at http://dx.doi.org/10.1162/COMJ_a_00297. This article may be used for non-commercial purposes in accordance with MIT Press Journal's Terms and Conditions for Self-Archiving. © 2015, MIT Press Journal

Frequency of HIV-1 Viral Load Monitoring of Patients Initially Successfully Treated with Combination Antiretroviral Therapy

BACKGROUND: Although considered an essential tool for monitoring the effect of combination antiretroviral treatment (CART), HIV-1 RNA (viral load, VL) testing is greatly influenced by cost and availability of resources. ----- OBJECTIVES: To examine whether HIV infected patients who were initially successfully treated with CART have less frequent monitoring of VL over time and whether CART failure and other HIV-disease and sociodemographic characteristics are associated with less frequent VL testing. ----- METHODS: The study included patients who started CART in the period 1999-2004, were older than 18 years, CART naive, had two consecutive viral load measurements of <400 copies/ml after 5 months of treatment and had continuous CART during the first 15 months. The time between two consecutive visits (days) was the outcome and associated factors were assessed using linear mixed models. ----- RESULTS: We analyzed a total of 128 patients with 1683 visits through December 2009. CART failure was observed in 31 (24%) patients. When adjusted for the follow-up time, the mean interval between two consecutive VL tests taken in patients before CART failure (155.2 days) was almost identical to the interval taken in patients who did not fail CART (155.3 days). On multivariable analysis, we found that the adjusted estimated time between visits was 150.9 days before 2003 and 177.6 in 2008/2009. A longer time between visits was observed in seafarers compared to non-seafarers; the mean difference was 30.7 days (95% CI, 14.0 to 47.4; p<0.001); and in individuals who lived more than 160 kilometers from the HIV treatment center (mean difference, 16 days, p=0.010). ----- CONCLUSIONS: Less frequent monitoring of VL became common in recent years and was not associated with failure. We identified seafarers as a population with special needs for CART monitoring and delivery

The Influence of Corporate Front-Group Stealth Campaigns

This research examined corporate front-group stealth campaigns. An experiment was conducted to examine the influence of front-group stealth campaigns on a variety of measures. It was anticipated that corporate front-group stealth campaigns, which feature names that mask the true interests of sponsors, positively affect public opinion, unless they are exposed as intentionally misleading, in which case they boomerang against sponsors. The experiment examined the potential of the inoculation strategy to preempt the influence of corporate front-group stealth campaigns. The pattern of results supported all of these expectations. Front-group stealth campaigns proved to be effective, at least in the short term. Front-group stealth campaigns eroded public attitudes toward the issue in question and boosted perceptions of the front group, but not the corporate sponsor. However, when front-group stealth campaigns were subsequently exposed, positive effects dissipated and perceptions of corporate sponsors boomeranged. Results revealed that inoculation can protect against the influence of front-group stealth campaigns.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Self-Medication as Adaptive Plasticity: Increased Ingestion of Plant Toxins by Parasitized Caterpillars

Self-medication is a specific therapeutic behavioral change in response to disease or parasitism. The empirical literature on self-medication has so far focused entirely on identifying cases of self-medication in which particular behaviors are linked to therapeutic outcomes. In this study, we frame self-medication in the broader realm of adaptive plasticity, which provides several testable predictions for verifying self-medication and advancing its conceptual significance. First, self-medication behavior should improve the fitness of animals infected by parasites or pathogens. Second, self-medication behavior in the absence of infection should decrease fitness. Third, infection should induce self-medication behavior. The few rigorous studies of self-medication in non-human animals have not used this theoretical framework and thus have not tested fitness costs of self-medication in the absence of disease or parasitism. Here we use manipulative experiments to test these predictions with the foraging behavior of woolly bear caterpillars (Grammia incorrupta; Lepidoptera: Arctiidae) in response to their lethal endoparasites (tachinid flies). Our experiments show that the ingestion of plant toxins called pyrrolizidine alkaloids improves the survival of parasitized caterpillars by conferring resistance against tachinid flies. Consistent with theoretical prediction, excessive ingestion of these toxins reduces the survival of unparasitized caterpillars. Parasitized caterpillars are more likely than unparasitized caterpillars to specifically ingest large amounts of pyrrolizidine alkaloids. This case challenges the conventional view that self-medication behavior is restricted to animals with advanced cognitive abilities, such as primates, and empowers the science of self-medication by placing it in the domain of adaptive plasticity theory