Sodium Phenobarbital In Prevention of Electroconvulsive Shock-Induced Disruption of Taste-Illness Association

Male Holtzman rats injected with a toxic solution of lithium chloride (US) 30 minutes after drinking saccharin flavored water (CS) learned to avoid that taste upon subsequent encounter. Electroconvulsive shock (ECS) interpolated temporarily between the pairing of a novel taste (CS) and an induced gustatory illness (US) prevents the taste from being associated with the illness (Kral, 1971). The purpose of the present experiment was to determine if sodium phenobarbital pretreatment would protect the association of taste with illness, against the normally interfering effects of ECS in the interpolated intervention paradigm. This question was investigated with a 2 (sodium phenobarbital vs. saline) x 2 (ECS vs. sham shock) x 2 (conditioned vs. nonconditioned) x 2 (conditioning day vs. test day) analysis of variance design. Results suggest sodium phenobarbital pretreatment to be ineffective in preventing against ECS disruption of the taste-illness association. Conditioning of the taste aversion and ECS disruption occurred in both drug and non drug groups

Configurational studies of asymmetric star polymers

A series of miktoarm star polybutadienes were investigated in the melt and dilute solution state by neutron and light scattering and viscometry techniques. The stars had 8-arms, with a single asymmetric arm of varying molecular weight. Living anionic polymerisation synthesised the arms to be coupled by chlorosilane core molecules, with the molecular weight of the hydrogenous arms being 3 x 10(^4) g mol(^-1) and increasing for the deuterated arm from 3 x 10(^4) g mol(^-1) to 3 x 10(^5) g mol(^-1). Global properties of Mw, RG, A(_2), D(_0) and [η] were ascertained for these stars in the good solvent of cyclohexane, and over a temperature range in the 6-solvent of 1,4-dioxane. Branching ratios calculated from the cyclohexane data indicated that increasing the asymmetric arm length yielded values similar to a linear polymer of equivalent molecular weight, with a reduction of segment density near the star core. This was seen more clearly by calculating the size ratios of Rt/Rg, RhIRg and RylRc from the equivalent sphere radii. Aggregation of the stars was found with the dioxane solutions, as the Mw of these stars increased with decreasing temperature to values higher than obtained in cyclohexane, where they remained constant and equal to the good solvent data for the linear polymers. Small-angle neutron scattering was used to determine the Rg and interaction parameters for the asymmetric arm in the melt and solution states. The increase of Rg in the order of unperturbed linear equivalent<melt<cyclohexane was due to the presence of the branch point and the excluded volume effect. Higher Rg values obtained in the 9-solvent suggested aggregation. An increase in temperature in the melt state was found to promote inter-star mixing of the asymmetric arms and this was greater for shorter arms. In cyclohexane, the intra-star interaction parameters were found to decrease with increasing asymmetric arm length, and lower values were found in 1,4-dioxane as the solvent became thermodynamically more favourable

Immune function keeps endosymbionts under control

How does an animal host prevent intracellular symbionts getting out of hand? A new paper in BMC Biology provides evidence that the mutualism between a beetle and its bacterial endosymbiont could be mediated through the expression of host immune genes

Cooking up the perfect insect::Aristotle's transformational idea about the complete metamorphosis of insects

Aristotle made important contributions to the study of developmental biology, including the complete metamorphosis of insects. One concept in particular, that of the perfect or complete state, underlies Aristotle's ideas about metamorphosis, the necessity of fertilization for embryonic development, and whether morphogenesis involves an autonomous process of self-assembly. Importantly, the philosopher erroneously views metamorphosis as a necessary developmental response to lack of previous fertilization of the female parent, a view that is intimately connected with his readiness to accept the idea of the spontaneous generation of life. Aristotle's work underpins that of the major seventeenth century students of metamorphosis, Harvey, Redi, Malpighi and Swammerdam, all of whom make frequent reference to Aristotle in their writings. Although both Aristotle and Harvey are often credited with inspiring the later prolonged debate between proponents of epigenesis and preformation, neither actually held firm views on the subject. Aristotle's idea of the perfect stage also underlies his proposal that the eggs of holometabolous insects hatch 'before their time', an idea that is the direct precursor of the much later proposals by Lubbock and Berlese that the larval stages of holometabolous insects are due to the 'premature hatching' from the egg of an imperfect embryonic stage. This article is part of the theme issue 'The evolution of complete metamorphosis'.</p

A Significant Threat to Neuropsychological Test Validity

Objective: Neuropsychological test security is vital to the validity of assessment. Previous research in our lab has shown that 71% of participants use the Internet to prepare for neuropsychological evaluations (Kimpton, 2015). We investigated the availability of information related to neuropsychological tests on the Internet, a topic that has received little attention in the research literature. Participants and Methods: First, we decided a priori that we would not reveal the terms used in this Internet search, as to not contribute to the problem of threatened test security. We used the Internet search engine “Google” to begin a search using a general question that a person with no neuropsychological expertise would use to access initial results. We obtained 899,000 results for this question. We decided that of these results, we would select from the first five results. One link provided us with a list of 52 commonly used neuropsychological tests. This list also included information about the type of cognitive information that the test was meant to assess. Lastly, we searched for these tests on Google Images and YouTube in order to investigate the extent of the information available. Results: The protocols for 43% of the 52 tests were available on Google Images. At least partial administration demonstrations were available on YouTube for 54% of the 52 neuropsychological tests. These demonstrations revealed the test protocols and basic strategy of the tests. Conclusions: A substantial amount of information regarding neuropsychological tests is available on Google Images and YouTube, threatening the validity of these tests. It is recommended that professional neuropsychological associations begin to develop guidelines regarding appropriate content for websites and identify and continuously monitor websites that contain threatening information

Experimental archeology and serious games: challenges of inhabiting virtual heritage

Experimental archaeology has long yielded valuable insights into the tools and techniques that featured in past peoples’ relationship with the material world around them. However, experimental archaeology has, hitherto, confined itself to rigid, empirical and quantitative questions. This paper applies principles of experimental archaeology and serious gaming tools in the reconstructions of a British Iron Age Roundhouse. The paper explains a number of experiments conducted to look for quantitative differences in movement in virtual vs material environments using both “virtual” studio reconstruction as well as material reconstruction. The data from these experiments was then analysed to look for differences in movement which could be attributed to artefacts and/or environments. The paper explains the structure of the experiments, how the data was generated, what theories may make sense of the data, what conclusions have been drawn and how serious gaming tools can support the creation of new experimental heritage environments