The rat's anticipation of diurnal and a-diurnal feeding

Rats anticipation of diurnal and a-diurnal feedin

Management of european red mite populations on apple and plum trees with soybean oil

Degummed soybean oil emulsions were compared to a standard petroleum oil emulsion for efficacy against overwintering and summer populations of European red mite, (ERM), Panonychus ulmi Koch, on apple and plum trees in a commercial orchard, Russellville, TN, in 1994 and 1995. Oils were applied with a handgun sprayer to dormant and delayed-dormant bud stage trees to kill overwintering ERM eggs and suppress mite populations. Summer oil applications were tested on apple for their effect on motile ERM and predatory mites. A dormant application of 5.0% soybean oil plus a delayed-dormant application of 2.0% soybean oil significantly reduced ERM populations in April, May, and June on apple. A summer spray of 0.5% soybean oil reduced ERM densities below densities on the control trees or the 0.25% soybean oil-treated trees. ERM densities were lower on plum trees treated with a dormant application of 5.0% soybean oil plus a delayed-dormant application of 2.0% soybean than densities on control trees in June 1994. The use of soybean oil emulsions has potential as a management practice for winter and summer ERM populations on apple and plum trees. ERM larvae appeared on apple trees in early April. In eastern Tennessee, oil sprays should be most effective when applied just prior to the hatching of overwintering eggs, in late March. Approximately eight generations of ERM were observed on apple in 1994

A live, impaired-fidelity coronavirus vaccine protects in an aged, immunocompromised mouse model of lethal disease

Live-attenuated RNA virus vaccines are efficacious but subject to reversion to virulence. Among RNA viruses, replication fidelity is recognized as a key determinant of virulence and escape from antiviral therapy; increased fidelity is attenuating for some viruses. Coronavirus replication fidelity is approximately 20-fold greater than that of other RNA viruses and is mediated by a 3′-5′ exonuclease activity (ExoN) that likely functions in RNA proofreading. In this study, we demonstrate that engineered inactivation of SARS-CoV ExoN activity results in a stable mutator phenotype with profoundly decreased fidelity in vivo and attenuation of pathogenesis in young, aged, and immunocompromised mouse models of human SARS. The ExoN inactivation genotype and mutator phenotype are stable and do not revert to virulence, even after serial passage or long-term persistent infection in vivo. Our approach represents a strategy with potential for broad applications for the stable attenuation of coronaviruses and possibly other RNA viruses

Realism, Instrumentalism, and Scientific Symbiosis: Psychological Theory as a search for truth and the discovery of solutions

Scientific realism holds that scientific theories are approximations of universal truths about reality, whereas scientific instrumentalism posits that scientific theories are intellectual structures that provide adequate predictions of what is observed and useful frameworks for answering questions and solving problems in a given domain. These philosophical perspectives have different strengths and weaknesses and have been regarded as incommensurate: Scientific realism fosters theoretical rigor, verifiability, parsimony, and debate, whereas scientific instrumentalism fosters theoretical innovation, synthesis, generativeness, and scope. The authors review the evolution of scientific realism and instrumentalism in psychology and propose that the categorical distinction between the 2 is overstated as a prescription for scientific practice. The authors propose that the iterative deployment of these 2 perspectives, just as the iterative application of inductive and deductive reasoning in science, may promote more rigorous, integrative, cumulative, and useful scientific theories

Aversive Learning in Honeybees Revealed by the Olfactory Conditioning of the Sting Extension Reflex

Invertebrates have contributed greatly to our understanding of associative learning because they allow learning protocols to be combined with experimental access to the nervous system. The honeybee Apis mellifera constitutes a standard model for the study of appetitive learning and memory since it was shown, almost a century ago, that bees learn to associate different sensory cues with a reward of sugar solution. However, up to now, no study has explored aversive learning in bees in such a way that simultaneous access to its neural bases is granted. Using odorants paired with electric shocks, we conditioned the sting extension reflex, which is exhibited by harnessed bees when subjected to a noxious stimulation. We show that this response can be conditioned so that bees learn to extend their sting in response to the odorant previously punished. Bees also learn to extend the proboscis to one odorant paired with sugar solution and the sting to a different odorant paired with electric shock, thus showing that they can master both appetitive and aversive associations simultaneously. Responding to the appropriate odorant with the appropriate response is possible because two different biogenic amines, octopamine and dopamine subserve appetitive and aversive reinforcement, respectively. While octopamine has been previously shown to substitute for appetitive reinforcement, we demonstrate that blocking of dopaminergic, but not octopaminergic, receptors suppresses aversive learning. Therefore, aversive learning in honeybees can now be accessed both at the behavioral and neural levels, thus opening new research avenues for understanding basic mechanisms of learning and memory

Superquadric-Based Object Recognition

This paper proposes a technique for object recognition using superquadric built models. Superquadrics, which are three dimensional models suitable for part-level representation of objects, are reconstructed from range images using the recover-and-select paradigm. Using an interpretation three, the presence of an object in the scene from the model database can be hypothesized. These hypotheses are verified by projecting and re-fitting the object model to the range image which at the same time enables a better localization of the object in the scene