Synthesis and Reduction Kinetics of Sterically Shielded Pyrrolidine Nitroxides

A series of sterically shielded pyrrolidine nitroxides were synthesized and their reduction by ascorbate (vitamin C) indicate that nitroxide 3 – a tetraethyl derivative of 3-carboxy-PROXYL – is reduced at the slowest rate among known nitroxides, i.e., at a 60-fold slower rate than that for 3- carboxy-PROXYL

‘It stays with you’: multiple evocative representations of dance and future possibilities for studies in sport and physical cultures

This article considers the integration of arts-based representations via poetic narratives together with artistic representation on dancing embodiment so as to continue an engagement with debates regarding multiple forms/representations. Like poetry, visual images are unique and can evoke particular kinds of emotional and visceral responses, meaning that alternative representational forms can resonate in different and powerful ways. In the article, we draw on grandparent-grandchild interactions, narrative poetry, and artistic representations of dance in order to illustrate how arts-based methods might synergise to offer new ways of ‘knowing’ and ‘seeing’. The expansion of the visual arts into interdisciplinary methodological innovations is a relatively new, and sometimes contentious approach, in studies of sport and exercise. We raise concerns regarding the future for more arts-based research in the light of an ever-changing landscape of a neoliberal university culture that demands high productivity in reductionist terms of what counts as ‘output’, often within very restricted time-frames. Heeding feminist calls for ‘slow academies’ that attempt to ‘change’ time collectively, and challenge the demands of a fast-paced audit culture, we consider why it is worth enabling creative and arts-based methods to continue to develop and flourish in studies of sport, exercise and health, despite the mounting pressures to ‘perform’

GM crops and gender issues

Correspondence in the December issue by Jonathan Gressel not only states that gender issues in rural settings have not been adequately addressed with respect to weed control biotech but also asserts that such technology can increase the quality of life of rural women in developing countries. Improved weed control is a labor-saving technology that can result in less employment in a labor surplus rural economy. Often in rural areas, wage income is the main source of income and an important determinant of the quality of life, particularly where employment opportunities are generally limited. Apart from soil preparation, planting and weeding, harvesting is also 'femanual' work that can generate more employment if yields are higher. Biotech can enhance the quality of life of women but only if the technology is associated with overall generation of rural employment

SEW-ing a Simple Endorsement Web to incentivize trustworthy participatory sensing

Two crucial issues to the success of participatory sensing are (a) how to incentivize the large crowd of mobile users to participate and (b) how to ensure the sensing data to be trustworthy. While they are traditionally being studied separately in the literature, this paper proposes a Simple Endorsement Web (SEW) to address both issues in a synergistic manner. The key idea is (a) introducing a social concept called nepotism into participatory sensing, by linking mobile users into a social \u27web of participants\u27 with endorsement relations, and (b) overlaying this network with investment-like economic implications. The social and economic layers are interleaved to provision and enhance incentives and trustworthiness. We elaborate the social implications of SEW, and analyze the economic implications under a Stackelberg game framework. We derive the optimal design parameter that maximizes the utility of the sensing campaign organizer, while ensuring participants to strictly have incentive to participate. We also design algorithms for participants to optimally \u27sew\u27 SEW, namely to manipulate the endorsement links of SEW such that their economic benefits are maximized and social constrains are satisfied. Finally, we provide two numerical examples for an intuitive understanding

Prophase-Specific Perinuclear Actin Coordinates Centrosome Separation and Positioning to Ensure Accurate Chromosome Segregation

Centrosome separation in late G2/ early prophase requires precise spatial coordination that is determined by a balance of forces promoting and antagonizing separation. The major effector of centrosome separation is the kinesin Eg5. However, the identity and regulation of Eg5-antagonizing forces is less well characterized. By manipulating candidate components, we find that centrosome separation is reversible and that separated centrosomes congress toward a central position underneath the flat nucleus. This positioning mechanism requires microtubule polymerization, as well as actin polymerization. We identify perinuclear actin structures that form in late G2/early prophase and interact with microtubules emanating from the centrosomes. Disrupting these structures by breaking the interactions of the linker of nucleoskeleton and cytoskeleton (LINC) complex with perinuclear actin filaments abrogates this centrosome positioning mechanism and causes an increase in subsequent chromosome segregation errors. Our results demonstrate how geometrical cues from the cell nucleus coordinate the orientation of the emanating spindle poles before nuclear envelope breakdown

Optimal Prizes for All-Pay Contests in Heterogeneous Crowdsourcing

Incentive is key to the success of crowd sourcing which heavily depends on the level of user participation. This paper designs an incentive mechanism to motivate a heterogeneous crowd of users to actively participate in crowd sourcing campaigns. We cast the problem in a new, asymmetric all-pay contest model with incomplete information, where an arbitrary n of users exert irrevocable effort to compete for a prize tuple. The prize tuple is an array of prize functions as opposed to a single constant prize typically used by conventional contests. We design an optimal contest that (a) induces the maximum profit -- total user effort minus the prize payout -- for the crowdsourcer, and (b) ensures users to strictly have incentive to participate. In stark contrast to intuition and prior related work, our mechanism induces an equilibrium in which heterogeneous users behave independently of one another as if they were in a homogeneous setting. This newly discovered property, which we coin as strategy autonomy (SA), is of practical significance: it (a) reduces computational and storage complexity by n-fold for each user, (b) increases the crowdsourcer's revenue by counteracting an effort reservation effect existing in asymmetric contests, and (c) neutralizes the (almost universal) law of diminishing marginal returns (DMR). Through an extensive numerical case study, we demonstrate and scrutinize the superior profitability of our mechanism, as well as draw insights into the SA property

The interview as narrative ethnography : seeking and shaping connections in qualitative research.

Acts of counter-subjectification in qualitative research are always present but are often submerged in accounts that seek to locate the power of subjectification entirely with the researcher. This is particularly so when talking to people about sensitive issues. Based on an interview-based study of infertility and reproductive disruption among British Pakistanis in Northeast England, we explore how we, as researchers, sought and were drawn into various kinds of connections with the study participants; connections that were actively and performatively constructed through time. The three of us that conducted interviews are all female academics with Ph.Ds in anthropology, but thereafter our backgrounds, life stories and experiences diverge in ways that intersected with those of our informants in complex and shifting ways. We describe how these processes shaped the production of narrative accounts and consider some of the associated analytical and ethical implications

Hacking events: project development practices and technology use at hackathons

Hackathons are techno-creative events during which participants get together in a physical location. They may be hosted by civic communities, corporations or public institutions. Working individually or in teams, usually for several days, participants develop projects such as hardware or software prototypes. Based on a digital ethnography of two events in the Netherlands and Denmark, this article investigates project development practices at hackathons. In particular, it analyses how participants organized their project work and which technologies were used in support of their creative endeavours. Hackathons are increasingly competitive rather than collaborative events, involving time pressure, inducements such as prizes, and requiring efficient skills utilization. I argue that this facilitates the following tendencies: Firstly, strategic effort is put into final presentations. Projects need to be convincingly presented, and persuasively pitching an idea becomes crucial. Secondly, there is only limited time for personal learning, since participants’ existing skills need to be efficiently applied if a team wants to stay competitive. This encourages division of labour within groups: a tendency which seems especially problematic given that IT skills biases are often expressed in terms of gender. Thirdly, participants are more inclined to use technologies that are proprietary but appear ‘open enough’. In light of this observation and by drawing on the concept of technology as resource and opportunity, I discuss the techno-political implications of utilized technologies. With this analysis, I aim at contributing to the critical debate on hackathons as productive but likewise ideologically significant fields of ‘hacking cultures’

Professional helping as negotiation in motion: social work as work on the move

The delivery of welfare and professional helping, such as in medicine, nursing and social work is largely treated as though it is achieved through static and immobile practices. Research has been dominated by a focus on the sedentary as studies have stayed rooted in places like hospitals and offices, failing to follow practitioners when they go out to see their service users in their communities and homes. This paper explores the mobile character of professional helping through a focus on social work by examining what its practices look like through the lens of movement based social science. The paper draws on empirical data from my mobile and sensory ethnography of child protection work, where I went along with social workers and interviewed them in the car and observed them on home visits to families. It is argued that attention to movement gets to the heart of what these practices are, as shown in the multiple meanings of car journeys, and how keeping children safe relies on worker’s capacities to move their bodies when in the home by walking, playing with and staying close to the child. Professional help goes on through what Jenson calls “negotiation in motion”. Fundamentally, social work is work on the move