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New and Exciting in PLoS ONE

There are 34 articles published in PLoS ONE this week. As always, look around, read, rate, comment, annotate…. Here are my picks for the week (no need to repeat the dinosaur paper here, of course):

A Viscoelastic Deadly Fluid in Carnivorous Pitcher Plants:

Carnivorous pitcher plants supplement their nutrient intake by trapping and digesting insects in what were thought to be passive pitfall traps. But in this study, the authors show that the pitchers of plants Nepenthes rafflesiana in fact employ highly specialized secretions to doom their victims. They show that this fluid, even when diluted, has the perfect viscoelastic properties to prevent the escape of any small creatures that come into contact with it.

The Golden Beauty: Brain Response to Classical and Renaissance Sculptures:

Speculation and debate often surround the question of whether the experience of beauty in art is based upon objective biological factors or individual subjective perception. In this study, a group of researchers attempted to answer this question by measuring brain activity in people who were exposed to original and modified images of masterpieces of Classical and Renaissance sculpture. The results suggest that in naïve art observers, a sense of beauty is determined by both objective beauty and emotional experiences.

The Effect of Real-World Personal Familiarity on the Speed of Face Information Processing:

In this study, Balas and colleagues investigated whether people’s ability to process basic information about other individuals’ faces (for example, making a decision on the individual’s gender, identity, or orientation of the image) is affected by whether they know that person. The results showed, surprisingly, that real-world familiarity with an individual helps a person to process visual cues relating to that individual faster, even if identity is not required for performing that task. These findings highlight the importance of experience and familiarity in determining visual recognition processes.

Reappraisal of Vipera aspis Venom Neurotoxicity:

The variation of venom composition with geography is an important aspect of intraspecific variability in the Vipera genus, although causes of this variability remain unclear. The diversity of snake venom is important both for our understanding of venomous snake evolution and for the preparation of relevant antivenoms to treat envenomations. A geographic intraspecific variation in snake venom composition was recently reported for Vipera aspis aspis venom in France. Since 1992, cases of human envenomation after Vipera aspis aspis bites in south-east France involving unexpected neurological signs were regularly reported. The presence of genes encoding PLA2 neurotoxins in the Vaa snake genome led us to investigate any neurological symptom associated with snake bites in other regions of France and in neighboring countries. In parallel, we used several approaches to characterize the venom PLA2 composition of the snakes captured in the same areas. We conducted an epidemiological survey of snake bites in various regions of France. In parallel, we carried out the analysis of the genes and the transcripts encoding venom PLA2s. We used SELDI technology to study the diversity of PLA2 in various venom samples. Neurological signs (mainly cranial nerve disturbances) were reported after snake bites in three regions of France: Languedoc-Roussillon, Midi-Pyrénées and Provence-Alpes-Côte d’Azur. Genomes of Vipera aspis snakes from south-east France were shown to contain ammodytoxin isoforms never described in the genome of Vipera aspis from other French regions. Surprisingly, transcripts encoding venom neurotoxic PLA2s were found in snakes of Massif Central region. Accordingly, SELDI analysis of PLA2 venom composition confirmed the existence of population of neurotoxic Vipera aspis snakes in the west part of the Massif Central mountains. The association of epidemiological studies to genetic, biochemical and immunochemical analyses of snake venoms allowed a good evaluation of the potential neurotoxicity of snake bites. A correlation was found between the expression of neurological symptoms in humans and the intensity of the cross-reaction of venoms with anti-ammodytoxin antibodies, which is correlated with the level of neurotoxin (vaspin and/or ammodytoxin) expression in the venom. The origin of the two recently identified neurotoxic snake populations is discussed according to venom PLA2 genome and transcriptome data.

Season of Birth and Dopamine Receptor Gene Associations with Impulsivity, Sensation Seeking and Reproductive Behaviors:

Season of birth (SOB) has been associated with many physiological and psychological traits including novelty seeking and sensation seeking. Similar traits have been associated with genetic polymorphisms in the dopamine system. SOB and dopamine receptor genetic polymorphisms may independently and interactively influence similar behaviors through their common effects on the dopaminergic system. Based on a sample of 195 subjects, we examined whether SOB was associated with impulsivity, sensation seeking and reproductive behaviors. Additionally we examined potential interactions of dopamine receptor genes with SOB for the same set of traits. Phenotypes were evaluated using the Sociosexual Orientation Inventory, the Barratt Impulsivity Scale, the Eysenck Impulsivity Questionnaire, the Sensation Seeking Scale, and the Delay Discounting Task. Subjects were also asked about their age at first sex as well as their desired age at the birth of their first child. The dopamine gene polymorphisms examined were Dopamine Receptor D2 (DRD2) TaqI A and D4 (DRD4) 48 bp VNTR. Primary analyses included factorial gender×SOB ANOVAs or binary logistic regression models for each dependent trait. Secondary analysis extended the factorial models by also including DRD2 and DRD4 genotypes as independent variables. Winter-born males were more sensation seeking than non-winter born males. In factorial models including both genotype and season of birth as variables, two previously unobserved effects were discovered: (1) a SOB×DRD4 interaction effect on venturesomeness and (2) a DRD2×DRD4 interaction effect on sensation seeking. These results are consistent with past findings that SOB is related to sensation seeking. Additionally, these results provide tentative support for the hypothesis that SOB modifies the behavioral expression of dopaminergic genetic polymorphism. These findings suggest that SOB should be included in future studies of risky behaviors and behavioral genetic studies of the dopamine system.