Playing Charades in the fMRI: Are Mirror and/or Mentalizing Areas Involved in Gestural Communication?

Communication is an important aspect of human life, allowing us to powerfully coordinate our behaviour with that of others. Boiled down to its mere essentials, communication entails transferring a mental content from one brain to another. Spoken language obviously plays an important role in communication between human individuals. Manual gestures however often aid the semantic interpretation of the spoken message, and gestures may have played a central role in the earlier evolution of communication. Here we used the social game of charades to investigate the neural basis of gestural communication by having participants produce and interpret meaningful gestures while their brain activity was measured using functional magnetic resonance imaging. While participants decoded observed gestures, the putative mirror neuron system (pMNS: premotor, parietal and posterior mid-temporal cortex), associated with motor simulation, and the temporo-parietal junction (TPJ), associated with mentalizing and agency attribution, were significantly recruited. Of these areas only the pMNS was recruited during the production of gestures. This suggests that gestural communication relies on a combination of simulation and, during decoding, mentalizing/agency attribution brain areas. Comparing the decoding of gestures with a condition in which participants viewed the same gestures with an instruction not to interpret the gestures showed that although parts of the pMNS responded more strongly during active decoding, most of the pMNS and the TPJ did not show such significant task effects. This suggests that the mere observation of gestures recruits most of the system involved in voluntary interpretation.     

Cultural and reproductive success and the causes of war: A Yanomamö perspective

Inter-group competition including warfare is posited to be a key force in human evolution (Alexander, 1990; Choi & Bowles, 2007; Wrangham, 1999). Chagnon's research on the Yanomamö is seminal to understanding warfare in the types of societies characteristic of human evolutionary history. Chagnon's empirical analyses of the hypothesis that competition for status or cultural success is linked to reproduction (Irons, 1979) and warfare attracted considerable controversy. Potential causal factors include “blood revenge”, mate competition, resource shortages or inequality, and peace-making institutions (Boehm, 1984; Keeley's (1997); Meggitt, 1977; Wiessner and Pupu, 2012; Wrangham et al., 2006). Here we highlight Chagnon's contributions to the study of human warfare.     

Discharge�Ccalcium concentration relationships in streams of the Amazon and Cerrado of Brazil: soil or land use controlled

Stream discharge?Cconcentration relationships are indicators of terrestrial ecosystem function. Throughout the Amazon and Cerrado regions of Brazil rapid changes in land use and land cover may be altering these hydrochemical relationships. The current analysis focuses on factors controlling the discharge?Ccalcium (Ca) concentration relationship since previous research in these regions has demonstrated both positive and negative slopes in linear log₁₀discharge?Clog₁₀Ca concentration regressions. The objective of the current study was to evaluate factors controlling stream discharge?CCa concentration relationships including year, season, stream order, vegetation cover, land use, and soil classification. It was hypothesized that land use and soil class are the most critical attributes controlling discharge?CCa concentration relationships. A multilevel, linear regression approach was utilized with data from 28 streams throughout Brazil. These streams come from three distinct regions and varied broadly in watershed size (<1 to >10⁶ ha) and discharge (10^?5.7?C10^3.2 m³ s^?1). Linear regressions of log₁₀Ca versus log₁₀discharge in 13 streams have a preponderance of negative slopes with only two streams having significant positive slopes. An ANOVA decomposition suggests the effect of discharge on Ca concentration is large but variable. Vegetation cover, which incorporates aspects of land use, explains the largest proportion of the variance in the effect of discharge on Ca followed by season and year. In contrast, stream order, land use, and soil class explain most of the variation in stream Ca concentration. In the current data set, soil class, which is related to lithology, has an important effect on Ca concentration but land use, likely through its effect on runoff concentration and hydrology, has a greater effect on discharge?Cconcentration relationships.     

A war of attrition between larvae on the same host plant: Stay and starve or leave and be eaten?

Summary Many insect species lay their eggs according to a clumped distribution, which causes food shortage among the larvae. To avoid starvation, at least some larvae have to migrate to another plant at some stage. Even though this migration involves a high mortality risk, larvae (of, for example, the cinnabar moth) often leave before their host plant is defoliated, thereby enabling others to remain safely on the plant. To understand why this remarkable behaviour has evolved, we modelled the situation of two larvae on a small plant as a war of attrition. Our main conclusions are that, in the case where the larvae are unrelated, they should only migrate prior to defoliation in certain time periods, called migration periods, when the pay-off of leaving decreases. Moreover, the optimal migration time is a random variable. When the pay-off of leaving fluctuates, there can be several migration periods. In the case where the larvae are related, it can also be optimal to migrate when the pay-off of leaving increases. Relatedness increases the length and the number of the migration periods, as well as the leaving tendency during these periods. Furthermore, relatedness gives rise to a parent—offspring conflict over the optimal migration strategy.     

Pollen modelling, palaeoecology and archaeology: virtualisation and/or visualisation of the past?

Recent developments in pollen modelling and landscape reconstruction have the potential to have a profound impact on our understanding of landscape change related to human activity. Initial findings have already revealed the weaknesses of a number of key assumptions previously made about pollen–landscape relationships. Close interrelationships exist between landscape reconstruction based on pollen analysis and archaeology, and model-based developments raise a range of pertinent issues for both disciplines. These include the way in which past vegetation patterning is conceptualised (the patch vs. the matrix), the nature of the underlying physical environment in vegetation placement, the development of hypothesis-led approaches and the scale of landscapes under consideration. This paper discusses these issues, and also raises questions concerning the meaning of landscape. It may be erroneous to term pollen-based reconstructions as landscapes given the heavily charged meaning of the word as understood by companion and end user disciplines.     

Comets and the formation of biochemical compounds on the primitive Earth – A review

Thirty years ago it was suggested that comets impacting on the primitive Earth may have represented a significant source of terrestrial volatiles, including some important precursors for prebiotic synthesis (Oró, 1961,Nature 190: 389). This possibility is strongly supported not only by models of the collisional history of the early Earth, but also by astronomical evidence that suggests that frequent collisions of comet-like bodies from the circumstellar disk around the star Pictoris are taking place. Although a significant fraction of the complex organic compounds that appear to be present in cometary nuclei were probably destroyed during impact, it is argued that cometary collisions with the primitive Earth represented an important source of both free-energy and volatiles, and may have created transient, gaseous environments in which prebiotic synthesis may have taken place.     

“In vivo” pH values of the estrous reproductive tract of the gilt

The hydrogen ion concentration of the fluids of various portions of the reproductive tract was determined in 6 estrous gilts. Determinations were made with a pH cardiovascular catheter electrode placed in the lumen of the oviduct, uterus, cervix and vagina and a reference electrode placed in the peritoneal cavity. The mean pH values were 7.02, 6.98, 7.49, and 6.61 for the oviduct, uterus, cervix and vagina, respectively.     

Bringing the “General Strike” Back In: DuBois,Slavery and Emancipation

ABSTRACT

The “general strike” of slaves in the Civil War was a direct action that involved millions of small and large acts of defiance by slaves. These actions pushed President Lincoln from hesitation to full on military action, although this chapter of history has been neglected. The work of W.E.B. Du Bois reinserted the agency of slaves in their own liberation through the “general strike” but this analysis has also been pushed to the margins. David Roediger's “Seizing Freedom: Slave Emancipation and Liberty for All' is an important corrective to this historical omission.     

In a pickle: is cornichon just relish or part of the main dish?

The recent discovery that vertebrate homologs of Drosophila cornichon associate with AMPA receptors led to the unexpected notion that cornichons play a role in synaptic transmission. In this issue of Neuron, Kato et al. find that cornichons modulate the gating of TARP-associated AMPA receptors by preventing their resensitization to glutamate.     

Conservation tool or threatening process? management implications of interactions of cattle with vegetation and land at the Vale of Belvoir reserve

A recently purchased private reserve of high conservation value has been grazed in summer by cattle since the early nineteenth century. We ask whether the cattle are causing continuing damage and whether they are necessary to maintain any conservation values. We used five‐year‐old exclosures to determine the effects of cattle on wetland vegetation, mapped damage to soils and landforms and mapped cattle dung deposition in relation to the distributions of rare and threatened plant species. Cattle impacts on wetland plants were minor. Cattle damage to landforms by pugging and bank collapse was frequent near unfenced water bodies. Rare and threatened species were largely on well‐drained ground, while cattle dung was concentrated in wetlands and near water bodies. We conclude that cattle grazing is impacting some conservation values and is not necessary for conservation purposes. Destocking should be accompanied by careful monitoring of threatened plant populations. If necessary, alternative planned disturbances can provide regeneration niches for rare and threatened plants.     

Characterization of Giardia cell nucleus：Its implication on the nature and origin of the primitive cell nucleus

Thecentralproblemoftheoriginandearlyevolutionoftheeukaryoticcel1istheoriginofthecellnucleus,becausethecellnucleus,withitsdouble-layerednuclearenvelope,isthemostprominentandimportantmorphologicalmarkdistinguishingeukaryoticcellsfromprokaryotes.Eukaryoticcellsmayhavenochloroplast,mito-chondriaorflagellum,buttheymustpossessacellnucleus.Thecellnucleusitselfisaverycomplicatedstructure-Ifwetrytomakecleartheoriginandearlyevolutionofthecellnucleus,weoughttoinvestigatetheoriginandevolutionofeachmorphol…     

Memory and war: Tamil women’s experiences of Sri Lanka’s civil war

This article explores how Tamil women in Australia reconstruct memories of Sri Lanka’s war through postmemory and personal experiences. Tamil women’s understandings of war are important for unravelling multiple sites of marginalization across social and political landscapes that challenge dominant perspectives of being Tamil-Australian. The article draws on sixteen in-depth interviews with Tamil women resettled in Australia as children in the 1980s and 1990s, foregrounding their unique position as part of a war generation. It shows that Tamil women’s experiences of political engagement during the final stages of war were motivated by memories of individual and collective sufferings. However, loss, exclusion and forced migration characterize their ambivalent connections to homeland. Not always tied to dominant memories of war, victimhood and subordination, the article concludes that each Tamil woman represents ongoing resistances, survival and renegotiations of Tamil diasporic experiences of war that are produced by their memory and memory work.