4,424 research outputs found
Enhancement of drought-induced senescence by the reproductive sink in fertile lines of wheat and Sorghum
The leaf senescence pattern was examined in water-stressed male sterile and fertile lines of wheat (Triticum aestivum) and sorghum (Sorghum vulgare). The study was conducted at the seedling stage and during grain development. The loss of leaf area and chlorophyll content induced by water stress was similar in the male sterile and fertile lines of wheat at the seedling stage. At the grain filling stage, leaf senescence occurred at a faster rate in the fertile lines as compared to sterile lines of both wheat and sorghum. The study indicates that a reproductive sink accentuates drought-induced leaf senescence
Static dielectric response and Born effective charge of BN nanotubes from {\it ab initio} finite electric field calculations
{\it Ab initio} investigations of the full static dielectric response and
Born effective charge of BN nanotubes (BN-NTs) have been performed for the
first time using finite electric field method. It is found that the ionic
contribution to the static dielectric response of BN-NTs is substantial and
also that a pronounced chirality-dependent oscillation is superimposed on the
otherwise linear relation between the longitudinal electric polarizability and
the tube diameter (), as for a thin dielectric cylinderical shell. In
contrast, the transverse dielectric response of the BN-NTs resemble the
behavior of a thin (non-ideal) conducting cylindrical shell of a diameter of
\AA, with a screening factor of 2 for the inner electric field. The
medium principal component of the Born effective charge corresponding
to the transverse atomic displacement tangential to the BN-NT surface, has a
pronounced -dependence (but independent of chirality), while the large
longitudinal component exhibits a clear chirality dependence (but
nearly -independent), suggesting a powerful way to characterize the diameter
and chirality of a BN-NT.Comment: submitted to PR
From social machines to social protocols:Software engineering foundations for sociotechnical systems
The overarching vision of social machines is to facilitate social processes by having computers provide administrative support. We conceive of a social machine as a sociotechnical system (STS): a software-supported system in which autonomous principals such as humans and organizations interact to exchange information and services. Existing approaches for social machines emphasize the technical aspects and inadequately support the meanings of social processes, leaving them informally realized in human interactions. We posit that a fundamental rethinking is needed to incorporate accountability, essential for addressing the openness of the Web and the autonomy of its principals. We introduce Interaction-Oriented Software Engineering (IOSE) as a paradigm expressly suited to capturing the social basis of STSs. Motivated by promoting openness and autonomy, IOSE focuses not on implementation but on social protocols, specifying how social relationships, characterizing the accountability of the concerned parties, progress as they interact. Motivated by providing computational support, IOSE adopts the accountability representation to capture the meaning of a social machineâs states and transitions. We demonstrate IOSE via examples drawn from healthcare. We reinterpret the classical software engineering (SE) principles for the STS setting and show how IOSE is better suited than traditional software engineering for supporting social processes. The contribution of this paper is a new paradigm for STSs, evaluated via conceptual analysis
âMy Work Never Endsâ: Womenâs Experiences of Balancing Unpaid Care Work and Paid Work through WEE Programming in India
This paper seeks to lay bare the contours and consequences of the relationship between paid work and unpaid care work for women in low-income households, in order to better understand the relationship between womenâs participation in paid work and âeconomic empowermentâ. It is also interested in analysing whether, and if so how, women (may) achieve a positive balance between their unpaid care work and paid work responsibilities such that their economic empowerment is optimised (womenâs entry into paid work is enabled without deepening their time poverty or worrying about the quality of care received by their family), shared (across generations, so that other women/girls in the family are not left to bear the burden of care), and sustained (such that the quality of care provided to children improves as a result of their motherâs paid work). The paper seeks to do this by mapping the social organisation of care in low-income households across four sites in India, and assessing how women cope with their dual burdens. By focusing our analysis on two âwomenâs economic empowerment programmesâ: the Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA) in Rajasthan and the Self Employed Womenâs Association (SEWA) in Madhya Pradesh, we also seek to analyse how womenâs economic empowerment policy and programming can generate a
âdouble boonâ: paid work that empowers women and provides more support for their unpaid care work responsibilities.International Development Research Centre (IDRC)UK Department for International DevelopmentHewlett Foundatio
Co-creating âsmartâ sustainable food futures with urban food growers
The futuristic visions, infrastructures, and developments of smart cities continue to gather pace, with municipal authorities and businesses in the UK investing increasing amounts of resources into their manifestation. At the same time local communities continue to be hard hit by austerity, with more local services being affected by government cuts, with the North-East of England being particularly affected. In this paper we report on a case study that aimed to explore how the top-down, technocentric, and corporate visions of smart cities stand in contrast to the reality of grassroots communities who are dealing with the consequences of austerity. Our case study focuses on a community of urban food growers. We describe our speculative and participatory approach that we devised for co-designing âsmartâ urban food-growing futures from the bottom-up with local residents in a deprived neighbourhood of Newcastle upon Tyne, and reflect on how they elicited realities and future visions that stand as a counterpoint to the corporate visions of future cities
Early Results from the Wisconsin H-Alpha Mapper Southern Sky Survey
After a successful eleven-year campaign at Kitt Peak, we moved the Wisconsin
H-Alpha Mapper (WHAM) to Cerro Tololo in early 2009. Here we present some of
the early data after a few months under southern skies. These maps begin to
complete the first all-sky, kinematic survey of the diffuse H-alpha emission
from the Milky Way. Much of this emission arises from the Warm Ionized Medium
(WIM), a significant component of the ISM that extends a few kiloparsecs above
the Galactic disk. While this first look at the data focuses on the H-alpha
survey, WHAM is also capable of observing many other optical emission lines,
revealing fascinating trends in the temperature and ionization state of the
WIM. Our ongoing studies of the physical conditions of diffuse ionized gas will
continue from the southern hemisphere following the H-alpha survey. In
addition, future observations will cover the full velocity range of the
Magellanic Stream, Bridge, and Clouds to trace the ionized gas associated with
these neighboring systems.Comment: 4 pages, 2 figures. To appear in "The Dynamic ISM: A celebration of
the Canadian Galactic Plane Survey," ASP Conference Serie
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