Central Oregon obsidian from a submerged early Holocene archaeological site beneath Lake Huron.

Obsidian, originating from the Rocky Mountains and the West, was an exotic exchange commodity in Eastern North America that was often deposited in elaborate caches and burials associated with Middle Woodland era Hopewell and later complexes. In earlier times, obsidian is found only rarely. In this paper we report two obsidian flakes recovered from a now submerged paleolandscape beneath Lake Huron that are conclusively attributed to the Wagontire obsidian source in central Oregon; a distance of more than 4,000 km. These specimens, dating to ~ 9,000 BP, represent the earliest and most distant reported occurrence of obsidian in eastern North America.

Ostrich eggshell bead strontium isotopes reveal persistent macroscale social networking across late Quaternary southern Africa.

Hunter-gatherer exchange networks dampen subsistence and reproductive risks by building relationships of mutual support outside local groups that are underwritten by symbolic gift exchange. Hxaro, the system of delayed reciprocity between Ju/'hoãn individuals in southern Africa's Kalahari Desert, is the best-known such example and the basis for most analogies and models of hunter-gatherer exchange in prehistory. However, its antiquity, drivers, and development remain unclear, as they do for long-distance exchanges among African foragers more broadly. Here we show through strontium isotope analyses of ostrich eggshell beads from highland Lesotho, and associated strontium isoscape development, that such practices stretch back into the late Middle Stone Age. We argue that these exchange items originated beyond the macroband from groups occupying the more water-stressed subcontinental interior. Tracking the emergence and persistence of macroscale, transbiome social networks helps illuminate the evolution of social strategies needed to thrive in stochastic environments, strategies that in our case study show persistence over more than 33,000 y.

The association between network centrality and standard of living in a historical agrarian population.

OBJECTIVE: The aim of this study is to investigate the relationship between network centrality and living standards as measured by fertility and mortality responses to short-term economic stress. METHODS: Cox proportional hazard models estimate the effects of staple grain price variation and eigenvector and beta centrality within marriage and labor networks on the timing of births and child mortality (1-14 years) in a historical demographic data set from North Orkney, Scotland, 1851-1911. RESULTS: Households that are peripheral to the marriage and labor network experience lower chances of a birth when food prices are high. The fertility of more central households is less sensitive to price changes. A similar, but weaker, pattern holds for child mortality, which is also sensitive to price fluctuations, although the social gradient is not as clear. CONCLUSIONS: Marriage and labor network centrality is an indicator of standard of living in this remote, agricultural population. Households that are firmly embedded in the network are able to overcome and adjust to short-term economic stress without demographic consequences, while those at the edges of the community experience delayed reproduction in poor years consistent with unplanned responses to stress.

Social network analysis of obsidian artefacts and Maori interaction in northern Aotearoa New Zealand.

Over the span of some 700 years the colonizing populations of Aotearoa New Zealand grew, with subsequent changes in levels of interaction and social affiliation. Historical accounts document that Maori society transformed from relatively autonomous village-based groups into larger territorial lineages, which later formed even larger geo-political tribal associations. These shifts have not been well-documented in the archaeological record, but social network analysis (SNA) of pXRF sourced obsidian recovered from 15 archaeological sites documents variable levels of similarity and affiliation. Three site communities and two source communities are defined based on the differential proportions of obsidian from 13 distinct sources. Distance and travel time between archaeological sites and obsidian sources were not the defining factors for obsidian source selection and community membership, rather social considerations are implicated. Some archaeological sites incorporated material from far off sources, and in some instances geographically close sites contained material from different sources and were assigned to different communities. The analytical site communities constitute relational identifications that partially correspond to categorical identities of current Maori iwi (tribal) territories and boundaries. Based on very limited temporal information, these site communities are thought to have coalesced sometime after AD 1500. By incorporating previously published and unpublished data, the SNA of obsidian artefacts defined robust network communities that reflect differential levels of Maori interaction and affiliation.

Toffee Men, Travelling Drapers and Black-Market Perfumers-South Asian Networks of Petty Trade in Early Twentieth Century Britain.

Selling small wares, novelties, and affordable luxuries manufactured from artificial silk, the South Asian door-to-door pedlar or 'travelling draper', and his compatriot the 'Indian toffee man', were once fairly commonplace figures in British working-class life and the object of fond childhood recollections for many. Unfortunately, they have now largely drifted from popular memory, having left little trace in the historical record. However, this article's reconstruction of their lives offers a new perspective on the pivotal role inter-racial social networks played in pioneering South Asian immigration, settlement, and trade in Britain. New research into this pre-Partition, pre-Windrush immigration, particularly in and around the English industrial city of Sheffield, provides a more detailed and more nuanced understanding of their quotidian experience, their relationship to British society, and their reception by the working-class neighbourhoods within which they lived and plied their trade. The article emphasizes the men's enduring sense of agency and economic autonomy, despite the attempts of various departments of state to prevent them from exercising their right, as British subjects, to live and work in Britain.

The Odyssey's mythological network.

In this work, we study the mythological network of Odyssey of Homer. We use ordinary statistical quantifiers in order to classify the network as real or fictional. We also introduce an analysis of communities which allows us to see how network properties shall emerge. We found that Odyssey can be classified both as real and fictional network. This statement is supported as far as mythological characters are removed, which results in a network with real properties. The community analysis indicated to us that there is a power-law relationship based on the max degree of each community. These results allow us to conclude that Odyssey might be an amalgam of myth and of historical facts, with communities playing a central role.

Hepatic changes by benznidazole in a specific treatment for Chagas disease.

Chagas disease (Cd) is the third most common parasitic disease that causes damage to human health. Even a century after its description by Carlos Chagas and advances in its control, it remains a neglected disease. To eradicate the parasite or reduce the parasitic load, specific treatment for Trypanosoma cruzi (T. cruzi) is advisable; benznidazole (BNZ) is the drug that is currently prescribed. The purpose of this study is to report the adverse events (AE) due to the use of BNZ as a specific treatment for Cd, with a particular focus on hepatic changes. This was an observational, cross-sectional cohort study that included patients who were treated with BNZ. The medical records of patients who joined the Grupo de Estudo em doença de Chagas [Chagas Disease Study Group]/UNICAMP/Brazil and were treated with BNZ were reviewed for epidemiological, clinical, laboratory and AE parameters for the drug. The 204 patients who were assessed had an average age of 40.6 years ± 13.5 years, and 104 of them were women (50.98%). Fourteen (6.86%) individuals were in the acute phase of Cd, and 190 (93.13%) were in its chronic phase. AEs occurred in 85 patients (41.66%), 35 (41.17%) of whom had AEs related to the liver, characterized by an elevation of AST liver enzymes, ALT, alkaline phosphatase and gamma-glutamyltransferase (γGT). Other AEs that were observed included the following: 48 cases of cutaneous changes (56.47%), 8 cases of epigastric pain (9.41%), 7 cases of blood alteration (8.23%), and 3 cases of peripheral neuropathy (3.52%). Treatment was interrupted in 32 patients (37.64%) due to AD. Adverse events related to the liver secondary to the use of BNZ for Cd-specific treatment were frequent in this study and were characterized by an elevation of liver enzymes. Therefore, it is suggested that these enzymes be monitored during treatment with benznidazole.

The Social Media DNA of Mayo Clinic-and Health Care.

Hippocrates' admonition and the medical community's aversion to risk have caused many physicians and institutions to resist participation in modern social media sites such as Facebook (Facebook, Inc, Menlo Park, California, USA), Twitter (Twitter Inc, San Francisco, California, USA), and YouTube (San Mateo, California, USA). However, because Mayo Clinic's founders were champions of analog social networking, it was among the earliest hospitals worldwide to create official accounts on these digital platforms. A proper understanding of the traditional mechanisms of knowledge diffusion in medicine and of the nature of social media sites should help professionals see and embrace the opportunities for positive engagement in social media.

A long history of breakdowns: A historiographical review.

The introduction to this special issue argues that network breakdowns play an important and unacknowledged role in the shaping and emergence of scientific knowledge. It focuses on transnational scientific networks from the early modern Republic of Letters to 21st-century globalized science. It attempts to unite the disparate historiography of the early modern Republic of Letters, the literature on 20th-century globalization, and the scholarship on Actor-Network Theory. We can perceive two, seemingly contradictory, changes to scientific networks over the past four hundred years. At the level of individuals, networks have become increasing fragile, as developments in communication and transportation technologies, and the emergence of regimes of standardization and instrumentation, have made it easier both to create new constellations of people and materials, and to replace and rearrange them. But at the level of institutions, collaborations have become much more extensive and long-lived, with single projects routinely outlasting even the arc of a full scientific career. In the modern world, the strength of institutions and macro-networks often relies on ideological regimes of standardization and instrumentation that can flexibly replace elements and individuals at will.

The breakdown of Galileo's Roman network: Crisis and community, ca. 1633.

Rome has long been central to the story of Galileo's life and scientific work. Through an analysis of the metadata of Galileo's surviving letters, combined with a close reading of the letters themselves, we discuss how Galileo used correspondence to build a Roman network. Galileo initially assembled this network around the members of the Lincean Academy, a few carefully nurtured relationships with important ecclesiastics, and the expertise of well positioned Tuscan diplomats in the Eternal City. However, an analysis of Galileo's correspondence in the aftermath of the trial of 1633 provides us with a unique opportunity to interrogate how his altered circumstances transformed his social relations. Forced to confront the limitations on his activities imposed by Catholic censure and house arrest, Galileo experienced the effects of these restrictions in his relationships with others and especially in his plans for publication. In the years following 1633, Galileo turned his epistolary attention north to the Veneto and to Paris in order to publish his Two New Sciences. While Galileo's Lincean network and papal contacts in Rome were defunct after 1633, we see how Rome remained important to him as the site of a number of Roman disciples who would continue his intellectual project long after his own death.

Transnational science and collaborative networks. The case of Genetics and Radiobiology in Mexico, 1950-1970

The transnational approach of the science and technology studies (S&TS) abandons the nation as a unit of analysis in order to understand the development of science history. It also abandons Euro-US-centred narratives in order to explain the role of international collaborative networks and the circulation of knowledge, people, artefacts and scientific practices. It is precisely under this perspective that the development of genetics and radiobiology in Mexico shall be analyzed, together with the pioneering work of the Mexican physician-turnedgeneticist Alfonso León de Garay who spent two years in the Galton Laboratory in London under the supervision of Lionel Penrose. Upon his return de Garay funded the Genetics and Radiobiology Program of the National Commission of Nuclear Energy based on local needs and the aim of working beyond geographical limitations to thus facilitate the circulation of knowledge, practices and people. The three main lines of research conducted in the years after its foundation that were in line with international projects while responding to the national context were, first, cytogenetic studies of certain abnormalities, and the cytogenetics and anthropological studies of the Olympic Games held in Mexico in 1968; second, the study of the effects of radiation on hereditary material; and third, the study of population genetics in Drosophila and in Mexican indigenous groups. The program played a key role in reshaping the scientific careers of Mexican geneticists, and in transferring locally sourced research into broader networks. This case shows the importance of international collaborative networks and circulation in the constitution of national scientific elites, and also shows the national and transnational concerns that shaped local practices (AU)

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OutServe: an underground network stands up.

From the perspective of an insider, this article explains how an underground network of actively-serving lesbian, gay, bisexual, and transgender (LGBT) military members was formed, and able to engage in the fight against the Don't Ask, Don't Tell policy. By providing the means to connect with one another within the constraints of the law, OutServe enabled the voices of gay and lesbian active military personnel to be heard. This new visibility informed the political debate surrounding the policy and played a role in the final days of Don't Ask, Don't Tell.

Isolated in a technologically connected world?: Changes in the core professional ties of female researchers in Ghana, Kenya, and Kerala, India.

Using panel data gathered across two waves (2001 and 2005) from researchers in Ghana, Kenya, and Kerala, India, we examine three questions: (1) To what extent do gender differences exist in the core professional networks of scientists in low-income areas? (2) How do gender differences shift over time? (3) Does use of information and communication technologies (ICTs) mediate the relationship between gender and core network composition? Our results indicate that over a period marked by dramatic increases in access to and use of various ICTs, the composition and size of female researchers core professional ties have either not changed significantly or have changed in an unexpected direction. Indeed, the size of women's ties are retracting over time rather than expanding.

Young, black, and connected: Facebook usage among African American college students.

This article examines the extent and intensity of Facebook usage among African American college students and investigates their reasons for using Facebook. As expected, 98% of students in the survey had a Facebook account, and a large number of Facebook "friends." Younger users spent significantly more time on Facebook than older ones. Our findings underscore the importance of cultural influence for African American online users. Displaying photographs and personal interests on Facebook signals racial identity among African American college students. Personality traits, such as self-esteem, trust in people, satisfaction with university life, and racial identity, were not significant predictors on the time spent on Facebook.

The contribution of Facebook to the 2011 Tunisian revolution: a cyberpsychological insight.

The influence of Facebook in social life keeps constantly growing. Recently, the communication of information has been vital to the success of the Tunisian revolution, and Facebook was its main "catalyst." This study examines the key reasons that explain Facebook's contribution to this historical event, as perceived by Tunisian Internet users. To do so, we launched this study 5 days after the fall of the regime using an online questionnaire in which participants (N=333) first rated the importance of Facebook in the Tunisian revolution and then explained the reasons for their ratings. A cluster analysis based on the Euclidean distance between the most frequent words in the participants' text corpus (6,640 words), revealed three main clusters that we interpret as follows: 1: Facebook political function, 2: Facebook informational function, and 3: Facebook media platform function. It is likely that these factors reflect the dynamic of Tunisian cyberspace and the Tunisian Internet users' collective consciousness during the revolution.

Different effects of ethnic diversity on social capital: density of foundations and leisure associations in Amsterdam neighbourhoods.

This article examines the effect of ethnic diversity on social capital in Amsterdam neighbourhoods by looking at the effects of the ethnic diversity of a neighbourhood on the social networks that underpin civil society. A distinction is made between homogeneous, more individually oriented social networks, on the one hand, and horizontal heterogeneous networks on the other. The density of foundations­i.e. the number of foundations in a neighbourhood­is used as the indicator for the first type of networks and the density of leisure associations for the latter type. In addition, the study looks at the effect of a changing context in Amsterdam in which ethnic diversity has increasingly come to be perceived as problematic by inhabitants and local politicians. The results indeed show that ethnic diversity has a different effect on both forms of civil society: the horizontal heterogeneous networks suffer more from ethnic diversity than the homogeneous networks.

Bridges to nowhere: hosts, migrants, and the chimera of social capital in three African cities.

Interest in migrant social networks and social capital has grown substantially over the past several decades. The relationship between "host" and "migrant" communities remains central to these scholarly debates. Recently urbanized cities in Africa, which include large numbers of "native-born" or internal migrants, challenge basic presumptions about host/migrant distinctions informing many of these discussions. Using comparable survey data from Johannesburg, Maputo, and Nairobi, we examine 1) the nature of social connectedness in terms of residence and nativity characteristics; and 2) the relationship between residence and nativity characteristics and three measures of trust within and across communities. Our findings suggest that the host/migrant distinction may not be particularly revealing in African cities where domestic mobility, social fragmentation and the absence of bridging institutions result in relatively low levels of trust both within and across communities. These findings underscore the need for new concepts to study "communities of strangers" and how people strategize their social mobility in urban contexts.