A multilevel analytical framework for studying cultural evolution in prehistoric hunter–gatherer societies

Over the past decade, a major debate has taken place on the underpinnings of cultural changes in human societies. A growing array of evidence in behavioural and evolutionary biology has revealed that social connectivity among populations and within them affects, and is affected by, culture. Yet the interplay between prehistoric hunter–gatherer social structure and cultural transmission has typically been overlooked. Interestingly, the archaeological record contains large data sets, allowing us to track cultural changes over thousands of years: they thus offer a unique opportunity to shed light on long‐term cultural transmission processes. In this review, we demonstrate how well‐developed methods for social structure analysis can increase our understanding of the selective pressures underlying cumulative culture. We propose a multilevel analytical framework that considers finer aspects of the complex social structure in which regional groups of prehistoric hunter–gatherers were embedded. We put forward predictions of cultural transmission based on local‐ and global‐level network metrics of small‐scale societies and their potential effects on cumulative culture. By bridging the gaps between network science, palaeodemography and cultural evolution, we draw attention to the use of the archaeological record to depict patterns of social interactions and transmission variability. We argue that this new framework will contribute to improving our understanding of social interaction patterns, as well as the contexts in which cultural changes occur. Ultimately, this may provide insights into the evolution of human behaviour.     

To share or divide power? Minorities in autonomous regions,the case of the autonomous region in Muslim Mindanao

Abstract

Autonomy granted to minority groups as a form of power-sharing may not necessarily address the representation and welfare needs of the smaller minorities within the autonomous government. Although numerically insignificant, the smaller minorities' disempowerment and discrimination can lead to these groups' further marginalization and weaken the democratic viability and legitimacy of the autonomy project. What institutional mechanisms would work best for minorities-within-minorities in an autonomous region? Should similar power-sharing or consociational arrangements be replicated within the region? Or, are power-dividing measures and the integrative approach more appropriate for regional stability and democratic governance? Analyzing the institutional design of and practices in the Philippines' Autonomous Region in Muslim Mindanao, this paper concludes that a combination of power-sharing and power-dividing measures are needed to address the gaps in representation and protection of welfare of all ethnic groups for both the short- and long-term viability of regional autonomy.     

Red blood cells derived from peripheral blood and bone marrow CD34+ human haematopoietic stem cells are permissive to Plasmodium parasites infection

The production of fully functional human red cells in vitro from haematopoietic stem cells (hHSCs) has been successfully achieved. Recently, the use of hHSCs from cord blood represented a major improvement to develop the continuous culture system for Plasmodium vivax. Here, we demonstrated that CD34+hHSCs from peripheral blood and bone marrow can be expanded and differentiated to reticulocytes using a novel stromal cell. Moreover, these reticulocytes and mature red blood cells express surface markers for entrance of malaria parasites contain adult haemoglobin and are also permissive to invasion by P. vivax and Plasmodium falciparum parasites.     

Estudio de la vulnerabilidad neuronal selectiva en el sistema nervioso central humano

Introduction

The concept of ‘selective neuronal vulnerability’ refers to the differential sensitivity of neuronal populations in the nervous system to stresses that cause cell damage and lead to neurodegeneration. Because oxidative stress play a causal role in the physiological aging process, and it is often invoked as an aetiopathogenic and/or pathophysiological mechanism for neurodegeneration, in the present work we propose that the molecular bases of selective neuronal vulnerability is linked with cell adaptations related to oxidative stress.

Material and methods

The grey substance of 5 different regions from healthy human subjects (n = 7) were selected: i) to evaluate their membrane fatty acid profile by chromatographic methods, ii) to determine their membrane susceptibility to peroxidation, and iii) to recognise potential mechanisms involved in its regulation.

Results

The results showed significant inter-regional differences in the fatty acid profile, basically due to the content of mono- and highly polyunsaturated fatty acids; changes that, in turn, induce significant differences in theirs susceptibilities to peroxidation, as well as differences that can be ascribed to the desaturase activity.

Conclusion

Thus, the cross-regional comparative approach seems to confirm the idea that the level of cell membrane unsaturation may be a key trait associated with selective neuronal vulnerability.     

Prevalence of verotoxigenic Escherichia coli O157 (VTEC O157) and compliance with microbiological safety standards in bovine carcasses from an industrial beef slaughter plant

The presence of Salmonella spp. and levels of Enterobacteriaceae and aerobic plate count were determined in 300 bovine carcasses randomly collected in an industrial cattle slaughterhouse in Catalonia (Spain) as part of a control programme to validate good slaughter practices according to Commission Regulation No 2073/2005. The verotoxigenic Escherichia coli O157 (VTEC O157), although not currently legislated, was also investigated in the same carcasses due to the importance of bovines as a reservoir for this micro‐organism. Virulence genes (vtx1, vtx2 and eae), the presence of fliC_H7 and antimicrobial susceptibility were studied in E. coli O157 isolates. Levels of Enterobacteriaceae and aerobic colonies and the presence of Salmonella were within the admissible range stipulated by current legislation. However, VTEC O157 was detected in 14·7% of carcasses. Among the VTEC O157 strains tested for antimicrobial susceptibility, 65% were multiresistant. Overall, the results of this study indicate that even with good manufacturing practices, contamination with VTEC O157 can occur and cattle meat can pose a risk to human health. These results confirm the need for a review of the appropriateness of introducing antimicrobial treatments in the processing of cattle carcasses in Europe.

Significance and Impact of the Study

This study describes the prevalence of verotoxigenic and multidrug‐resistant E. coli O157 strains in bovine carcasses. These results suggest that despite the good manufacturing practices used in the slaughterhouse studied (the largest in Catalonia slaughtering over 81 000 cattle per year), the absence of verotoxigenic E. coli O157 in bovine carcasses cannot be guaranteed.     

The spinal cord expression of neuronal and inducible nitric oxide synthases and their contribution in the maintenance of neuropathic pain in mice

Background

Nitric oxide generated by neuronal (NOS1), inducible (NOS2) or endothelial (NOS3) nitric oxide synthases contributes to pain processing, but the exact role of NOS1 and NOS2 in the maintenance of chronic peripheral neuropathic pain as well as the possible compensatory changes in their expression in the spinal cord of wild type (WT) and NOS knockout (KO) mice at 21 days after total sciatic nerve ligation remains unknown.

Methodology/Principal Findings

The mechanical and thermal allodynia as well as thermal hyperalgesia induced by sciatic nerve injury was evaluated in WT, NOS1-KO and NOS2-KO mice from 1 to 21 days after surgery. The mRNA and protein levels of NOS1, NOS2 and NOS3 in the spinal cord of WT and KO mice, at 21 days after surgery, were also assessed. Sciatic nerve injury led to a neuropathic syndrome in WT mice, in contrast to the abolished mechanical allodynia and thermal hyperalgesia as well as the decreased or suppressed thermal allodynia observed in NOS1-KO and NOS2-KO animals, respectively. Sciatic nerve injury also increases the spinal cord expression of NOS1 and NOS2 isoforms, but not of NOS3, in WT and NOS1-KO mice respectively. Moreover, the presence of NOS2 is required to increase the spinal cord expression of NOS1 whereas an increased NOS1 expression might avoid the up-regulation of NOS2 in the spinal cord of nerve injured WT mice.

Conclusions/Significance

These data suggest that the increased spinal cord expression of NOS1, regulated by NOS2, might be responsible for the maintenance of chronic peripheral neuropathic pain in mice and propose these enzymes as interesting therapeutic targets for their treatment.     

Effect of pH on biological phosphorus uptake

An anaerobic aerobic laboratory scale sequencing batch reactor (SBR) was operated to study the effect of pH on enhanced biological phosphorus removal. Seven steady states were achieved under different operating conditions. In all of them, a slight variation in the pH value was observed during anaerobic phase. However, pH rose significantly during aerobic phase. The increase observed was due to phosphorus uptake and carbon dioxide stripping. When pH was higher than 8.2-8.25 the phosphorus uptake rate clearly decreased. The capability of Activated Sludge Model No. 2d (ASM2d) and Biological Nutrient Removal Model No. 1 (BNRM1) to simulate experimental results was evaluated. Both models successfully characterized the enhanced biological phosphorus removal performance of the SBR. Furthermore, BNRM1 also reproduced the pH variations observed and the decrease in the phosphorus uptake rate. This model includes a switch function in the kinetic expressions to represent the pH inhibition in biological processes. The pH inhibition constants related to polyphosphate storage process were obtained by adjusting model predictions to measured phosphorus concentrations. On the other hand, pH inhibition should be included in ASM2d to accurately simulate experimental phosphorus evolution observed in an A/O SBR.