63,576 research outputs found
Disability and Employer Practices: Research Across the Disciplines
[Excerpt] This book has three related purposes: To raise the visibility of the critical issues surrounding equitable employment for people with disabilities, with a focus on workplace policies and practices. To provide evidence of the importance of applying the very best science available to address these issues across all facets of the problem. To illustrate how combining scientific efforts from the different disciplines to work closely on a common purpose, as well as the intimate involvement of key stakeholders, can provide extraordinary results that inform needed changes to policy and practice
Implementing veterinary and animal welfare regulations in semi-natural pastoral landscapes in The Netherlands.
Universal Protocols for Information Dissemination Using Emergent Signals
We consider a population of agents which communicate with each other in a
decentralized manner, through random pairwise interactions. One or more agents
in the population may act as authoritative sources of information, and the
objective of the remaining agents is to obtain information from or about these
source agents. We study two basic tasks: broadcasting, in which the agents are
to learn the bit-state of an authoritative source which is present in the
population, and source detection, in which the agents are required to decide if
at least one source agent is present in the population or not.We focus on
designing protocols which meet two natural conditions: (1) universality, i.e.,
independence of population size, and (2) rapid convergence to a correct global
state after a reconfiguration, such as a change in the state of a source agent.
Our main positive result is to show that both of these constraints can be met.
For both the broadcasting problem and the source detection problem, we obtain
solutions with a convergence time of rounds, w.h.p., from any
starting configuration. The solution to broadcasting is exact, which means that
all agents reach the state broadcast by the source, while the solution to
source detection admits one-sided error on a -fraction of the
population (which is unavoidable for this problem). Both protocols are easy to
implement in practice and have a compact formulation.Our protocols exploit the
properties of self-organizing oscillatory dynamics. On the hardness side, our
main structural insight is to prove that any protocol which meets the
constraints of universality and of rapid convergence after reconfiguration must
display a form of non-stationary behavior (of which oscillatory dynamics are an
example). We also observe that the periodicity of the oscillatory behavior of
the protocol, when present, must necessarily depend on the number ^\\# X of
source agents present in the population. For instance, our protocols inherently
rely on the emergence of a signal passing through the population, whose period
is \Theta(\log \frac{n}{^\\# X}) rounds for most starting configurations. The
design of clocks with tunable frequency may be of independent interest, notably
in modeling biological networks
Anthropologies of Unemployment: New Perspectives on Work and Its Absence
[Excerpt] Anthropologies of Unemployment offers accessible, theoretically innovative, and ethnographically rich examinations of unemployment in rural and urban regions across North and South America, Europe, Africa, and Asia. The diversity of case studies demonstrates that unemployment is a pressing global phenomenon that sheds light on the uneven consequences of free-market ideologies and policies. Economic, social, and cultural marginalization is common in the lives of the unemployed, but their experience and interpretation are shaped by local and national cultural particularities. In exploring those differences, the contributors to this volume employ recent theoretical innovations and engage with some of the more salient topics in contemporary anthropology, such as globalization, migration, youth cultures, bureaucracy, class, gender, and race.
Taken together, the chapters reveal that there is something new about unemployment today. It is not a temporary occurrence, but a chronic condition. In adjusting to persistent, longstanding unemployment, people and groups create new understandings of unemployment as well as of work and employment; they improvise new forms of sociality, morality, and personhood. Ethnographic studies such as those found in Anthropologies of Unemployment are crucial if we are to understand the broader forms, meanings, and significance of pervasive economic insecurity and discover the emergence of new social and cultural possibilities
An investigation into linearity with cumulative emissions of the climate and carbon cycle response in HadCM3LC
We investigate the extent to which global mean temperature, precipitation, and the carbon cycle are constrained by cumulative carbon emissions throughout four experiments with a fully coupled climate-carbon cycle model. The two paired experiments adopt contrasting, idealised approaches to climate change mitigation at different action points this century, with total emissions exceeding two trillion tonnes of carbon in the later pair. Their initially diverging cumulative emissions trajectories cross after several decades, before diverging again. We find that their global mean temperatures are, to first order, linear with cumulative emissions, though regional differences in temperature of up to 1.5K exist when cumulative emissions of each pair coincide. Interestingly, although the oceanic precipitation response scales with cumulative emissions, the global precipitation response does not, due to a decrease in precipitation over land above cumulative emissions of around one trillion tonnes of carbon (TtC). Most carbon fluxes and stores are less well constrained by cumulative emissions as they reach two trillion tonnes. The opposing mitigation approaches have different consequences for the Amazon rainforest, which affects the linearity with which the carbon cycle responds to cumulative emissions. Averaged over the two fixed-emissions experiments, the transient response to cumulative carbon emissions (TCRE) is 1.95 K TtC-1, at the upper end of the IPCC’s range of 0.8-2.5 K TtC-1
Report of a GLOBEC-SPACC/IDYLE/ENVIFISH workshop on spatial approaches to the dynamics of coastal pelagic resources and their environment in upwelling areas
Strong spectral evolution during the prompt emission of GRB 070616
Swift has revealed features in GRB early light curves, such as steep decays
and X-ray flares, whose properties are consistent with an internal origin
though they are far from understood. The steep X-ray decay is often explained
using the curvature effect; however a significant number of GRBs display strong
spectral evolution during this phase, and a new mechanism must be invoked to
explain this. Of particular interest are the longest duration GRBs in which the
early emission can be studied in most detail. Here we present data for GRB
070616, in which the prompt emission shows a complex multipeaked structure,
leading to one of the longest prompt emission durations ever recorded. We take
advantage of extensive coverage of such a long burst by all Swift instruments.
Combining data from Swift and Suzaku we study the evolution of the prompt
emission spectrum, following the temporal variability of the peak energy and
spectral slope.Comment: 4 pages, 2 figures (Fig 1 in colour), contributed talk, submitted to
the proceedings of Gamma Ray Bursts 2007, Santa Fe, New Mexico, November 5-9
200
Towards a Model of Understanding Social Search
Search engine researchers typically depict search as the solitary activity of
an individual searcher. In contrast, results from our critical-incident survey
of 150 users on Amazon's Mechanical Turk service suggest that social
interactions play an important role throughout the search process. Our main
contribution is that we have integrated models from previous work in
sensemaking and information seeking behavior to present a canonical social
model of user activities before, during, and after search, suggesting where in
the search process even implicitly shared information may be valuable to
individual searchers.Comment: Presented at 1st Intl Workshop on Collaborative Information Seeking,
2008 (arXiv:0908.0583
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