Vesicular glutamate release from central axons contributes to myelin damage

Neuronal activity can lead to vesicular release of glutamate. Here the authors demonstrate that vesicular release of glutamate occurs in axons during ischemic conditions, and that an allosteric modulator of GluN2C/D is protective in models of ischemic injury

The formation of human populations in South and Central Asia

By sequencing 523 ancient humans, we show that the primary source of ancestry in modern South Asians is a prehistoric genetic gradient between people related to early hunter-gatherers of Iran and Southeast Asia. After the Indus Valley Civilization’s decline, its people mixed with individuals in the southeast to form one of the two main ancestral populations of South Asia, whose direct descendants live in southern India. Simultaneously, they mixed with descendants of Steppe pastoralists who, starting around 4000 years ago, spread via Central Asia to form the other main ancestral population. The Steppe ancestry in South Asia has the same profile as that in Bronze Age Eastern Europe, tracking a movement of people that affected both regions and that likely spread the distinctive features shared between Indo-Iranian and Balto-Slavic languages

Reconstructing Prehistoric African Population Structure

We assembled genome-wide data from 16 prehistoric Africans. We show that the anciently divergent lineage that comprises the primary ancestry of the southern African San had a wider distribution in the past, contributing approximately two-thirds of the ancestry of Malawi hunter-gatherers ∼8,100–2,500 years ago and approximately one-third of the ancestry of Tanzanian hunter-gatherers ∼1,400 years ago. We document how the spread of farmers from western Africa involved complete replacement of local hunter-gatherers in some regions, and we track the spread of herders by showing that the population of a ∼3,100-year-old pastoralist from Tanzania contributed ancestry to people from northeastern to southern Africa, including a ∼1,200-year-old southern African pastoralist. The deepest diversifications of African lineages were complex, involving either repeated gene flow among geographically disparate groups or a lineage more deeply diverging than that of the San contributing more to some western African populations than to others. We finally leverage ancient genomes to document episodes of natural selection in southern African populations

The context-dependent nature of small firms' relations with support agencies : a three-sector study in the UK

Strategic networking is widely seen to be important for small firms, but most attention has been given to the operation of networks rather than the nature of links with firms' strategies and resources. The article addresses these links through a study of 89 firms in three sectors. Variations in their involvement in external relationships are the focus. Previous theory suggests that product market conditions and firms' internal structures, such as reliance on family labour, will explain the level of involvement. The evidence supports some of these ideas but also shows that the context of the sector is central. For firms, the lesson is to develop distinct kinds of external relationship, depending on the firm's context and strategic position. The policy implication is that business support agencies need to be sensitive to these highly specific contextual factors

Alter-ontologies: Towards a constituent politics in technoscience

This paper identifies four recent conceptualizations of politics in relation to technoscience that focus on expertise, institutional participation, the inclusion of non-human others and the importance of marginalized experiences. The paper argues that each of these forms of politics is mainly concerned with renegotiating the already constituted terms of inclusion in a specific technoscientific field. In many cases such a strategy is necessary, but the paper aims to open up discussion of alternative forms of politics that act as constituent forces of radical social and material transformation in technoscience: alter-ontologies