The Neural Basis of Responsibility Attribution in Decision-Making

Social responsibility links personal behavior with societal expectations and plays a key role in affecting an agent’s emotional state following a decision. However, the neural basis of responsibility attribution remains unclear. In two previous event-related brain potential (ERP) studies we found that personal responsibility modulated outcome evaluation in gambling tasks. Here we conducted a functional magnetic resonance imaging (fMRI) study to identify particular brain regions that mediate responsibility attribution. In a context involving team cooperation, participants completed a task with their teammates and on each trial received feedback about team success and individual success sequentially. We found that brain activity differed between conditions involving team success vs. team failure. Further, different brain regions were associated with reinforcement of behavior by social praise vs. monetary reward. Specifically, right temporoparietal junction (RTPJ) was associated with social pride whereas dorsal striatum and dorsal anterior cingulate cortex (ACC) were related to reinforcement of behaviors leading to personal gain. The present study provides evidence that the RTPJ is an important region for determining whether self-generated behaviors are deserving of praise in a social context.     

Proposal for adoption of the base of the Undulograptus austrodentatus Biozone as a global Ordovician stage and series boundary level

The base of the Undulograptus austrodentatus Biozone appears to be a synchronous event that is widely recognizable within graptolitic facies around the world. It occurs within an interval in which graptolite species ranges are now well known and in which there is a rapid turnover in the composition of graptolite faunas. This turnover reflects the rapid evolutionary radiation of the Diplograptacea simultaneously with the appearance of several distinctive pseudisograptid and glossograptid species. These events provide the basis for the recognition of two thin but widely applicable subzones; a lower Arienigraptus zhejiangensis Subzone and an upper U. sinicus Subzone. The occurrence of the lower boundary of the U. austrodentatus Biozone within a succession of first appearances also permits accurate and reliable identification of the boundary as well as assessment of stratigraphic completeness across the boundary interval in correlated sections. Diverse graptolite faunas of late Yapeenian and early Darriwilian age occur in association with the Histiodella altifrons Biozone of the North American midcontinent conodont zonation and the Paroistodus originalis and Microzarkodina parva biozones of the North Atlantic conodont zonation. They also occur in association with the shelly-fossil zonations developed for several different continents. These features of the base of the U. austrodentatus Biozone make it a suitable level for use as the boundary level for a global stage. Its stratigraphic position within the Ordovician System relative to other likely global stages as well as its coincidence with one of the major events in graptolite evolutionary history suggest that this level also may be a suitable level for the base of a global Middle Ordovician Series.Ordovician System, Ordovician stages, graptolite zonation, chronostratigraphy, international correlation. Charles E. Mitchell and Jörg Maletz, Department of Geology, State University of New York at Buffalo, Buffalo, New York 14260-1550, USA; 13th July, 1994; revised 22nd May, 1995.     

Evidence for two unlinked loci regulating total serum IgE levels.

Studies investigating the genetic control of total serum IgE levels are of major importance in understanding basic pathophysiologic mechanisms in atopy and asthma, since IgE levels predict onset and correlate with the clinical expression of these disorders. Previous analysis of data from 92 families, ascertained through a parent with asthma, showed evidence for recessive inheritance of high IgE levels with linkage to chromosome 5q. Since there was significant residual familial correlation in the one-locus segregation analysis, two-locus segregation and linkage analyses were performed. Segregation analyses provided evidence for a second major locus unlinked to the locus on 5q. Utilization of this two-locus model corroborates the previous evidence for linkage between this trait and markers on 5q31-q33. The LODs for the most informative marker D5S436 increased from 3.00 at 10% recombination to 4.67 at 9% recombination, when the two-locus model was used. Additional linkage studies are needed to map this second locus. These results demonstrate the importance of performing multilocus segregation and linkage analyses for quantitative traits that are related to the phenotype of a complex disorder. This approach has given further insight into the genetics of allergy and asthma by providing evidence for a two-locus model.     

Bile pigment synthesis in plants. Incorporation of haem into phycocyanobilin and phycobiliproteins in Cyanidium caldarium.

A procedure was developed whereby haem was taken up by dark-grown cells of the unicellular rhodophyte Cyanidium caldarium. These cells were subsequently incubated either in the dark with 5-aminolaevulinate, which results in excretion of phycocyanobilin into the suspending medium or incubated in the light, which results in synthesis and accumulation of phycocyanin and chlorophyll a within the cells. Phycocyanobilin was isolated from phycocyanin by cleavage from apoprotein in methanol. Phycocyanobilin prepared from phycocyanin or excreted from cells given 5-aminolaevulinate was methylated and purified by t.l.c. By using 14C labelling either in the haem or in 5-aminolaevulinate administered, haem incorporation into phycocyanobilin was demonstrated in both dark and light systems. Since chlorophyll a synthesized in the light in the presence of labelled haem contained no radioactivity, it was clear that haem was directly incorporated into phycocyanobilin and not first converted into protoporphyrin IX. These results clearly demonstrate phycocyanobilin synthesis via haem and not via magnesium protoporphyrin IX as has also been postulated.     

Heterogeneity of Intermediate Filament Expression in Vascular Smooth Muscle: A Gradient in Desmin Positive Cells from the Rat Aortic Arch to the Level of the Arteria Iliaca Communis

The display of the two distinct intermediate filament proteins, desmin and vimentin, in rat vascular smooth muscle tissue was studied by immunofluorescence microscopy on frozen sections of aorta and other blood vessels. Vascular smooth muscle cells present in these vessels always appeared rich in vimentin. However, staining of sections covering six distinct but contiguous parts of the aorta showed that the number of desmin containing cells was low distal to the truncus brachiocephalicus, but increases until in distal parts of the aorta and in the arteria iliaca communis almost all cells appear positive for desmin. Thus blood vessels show heterogeneity of intermediate filament expression not only in cross-section but can also display heterogeneity along their length. Muscular arteries such as the renal artery and the arteria femoralis, as well as arterioles and veins including the vena jugularis and the vena cava also contain desmin. Thus it may be that low numbers of desmin-positive cells are typical of elastic arteries, while muscular arteries and other blood vessels are characterized by large numbers of desmin-positive cells. We discuss whether desmin-positive and desmin-negative vascular smooth muscle cells may perform different functions and raise the possibility that desmin expression may coincide with the turn on of a specially regulated contractility program.     

New Natural Noncannabinoid Ligands for Cannabinoid Type-2 (CB2) Receptors

Since the discovery that Δ ⁹-tetrahydrocannabinol and related cannabinoids from Cannabis sativa L. act on specific physiological receptors in the human body and the subsequent elucidation of the mammalian endogenous cannabinoid system, no other natural product class has been reported to mimic the effects of cannabinoids. We recently found that N-alkyl amides from purple coneflower (Echinacea spp.) constitute a new class of cannabinomimetics, which specifically engage and activate the cannabinoid type-2 (CB₂) receptors. Cannabinoid type-1 (CB₁) and CB₂ receptors belong to the family of G protein-coupled receptors and are the primary targets of the endogenous cannabinoids N-arachidonoyl ethanolamine and 2-arachidonoyl glyerol. CB₂ receptors are believed to play an important role in distinct pathophysiological processes, including metabolic dysregulation, inflammation, pain, and bone loss. CB₂ receptors have, therefore, become of interest as new targets in drug discovery. This review focuses on N-alkyl amide secondary metabolites from plants and underscores that this group of compounds may provide novel lead structures for the development of CB₂-directed drugs.     

Modeling mate-finding behavior of the swarming polychaete,Nereis succinea,with TangoInSilico,a scientific orkflow-based simulation system for sexual searching

Summary

Pheromones can be used as attractants for the opposite sex in many environments; however, little is known about the search strategies employed in responding to pheromones in the marine environment. The spawning behavior of males of the polychaete Nereis succinea is known to be triggered at close range by a high concentration (>～10^?7 M) of pheromone, cysteine glutathione disulfide (CSSG), released by females. Since CSSG also causes acceleration of swimming and increased turning, in addition to eliciting ejaculation, we proposed the hypothesis that these behaviors elicited by low concentrations of pheromone can be used by males to find females. The current study develops a computer simulation model of male and female N. succinea behavior for testing whether male responses to low concentrations of CSSG can facilitate finding females. Video recording of female swimming behavior in the field showed spontaneous loops, spirals, and circles that have been incorporated into the model. The scientific workflow paradigm within which the computer model has been developed also incorporates a data provenance system to enable systematic replay and testing of responses to individual parameters. Output of the model shows complex turning behavior leading to successful mating encounters at concentrations as low as 3×10^?9 M CSSG. Behavior resembling the output of the model was recorded in field observations. Application of the model in the future will be used to determine what pheromone concentrations produce significant increases in the probability of mating encounters.     

Phylogenetic analysis reveals that Rhabdopleura is an extant graptolite

A phylogenetic analysis of morphological data from modern pterobranch hemichordates (Cephalodiscus, Rhabdopleura) and representatives of each of the major graptolite orders reveals that Rhabdopleura nests among the benthic, encrusting graptolite taxa as it shares all of the synapomorphies that unite the graptolites. Therefore, rhabdopleurids can be regarded as extant members of the Subclass Graptolithina (Class Pterobranchia). Combined with the results of previous molecular phylogenetic studies of extant deuterostomes, these results also suggest that the Graptolithina is a sister taxon to the Subclass Cephalodiscida. The Graptolithina, as an important component of Early–Middle Palaeozoic biotas, provide data critical to our understanding of early deuterostome phylogeny. This result allows one to infer the zooid morphology, mechanics of colony growth and palaeobiology of fossil graptolites in direct relation to the living members of the clade. The Subdivision Graptoloida (nom. transl.), which are all planktic graptolites, is well supported in this analysis. In addition, we recognize the clade Eugraptolithina (nov.). This clade comprises the Graptoloida and all of the other common and well‐known graptolites of the distinctive Palaeozoic fauna. Most of the graptolites traditionally regarded as tuboids and dendroids appear to be paraphyletic groups within the Eugraptolithina; however, Epigraptus is probably not a member of this clade. The Eugraptolithina appear to be derived from an encrusting, Rhabdopleura‐like species, but the available information is insufficient to resolve the phylogeny of basal graptolites. The phylogenetic position of Mastigograptus and the status of the Dithecoidea and Mastigograptida also remain unresolved. □ Biodiversity, Cambrian, Hemichordata, Deuterostomia, Ordovician.