227 research outputs found
Environmental incomes and rural livelihoods : a global-comparative assessment
Various case studies have suggested that environmental incomes from forests and other
vegetation types are important for rural households in developing countries. However, in most
large-scale household surveys these income sources are either underreported or ignored, hence
there has been a lack of evidence to support the wider applicability of that claim. This paper
reports data from the Poverty Environment Network (PEN), which has gathered comparable
income data from about 8,000 households in 360 villages and 58 sites, spread over 24
developing countries. The data collection involved a careful, quarterly recording of all forest and
environmental uses, as well as other major income sources over one full year.
We find that forest income on average constitutes about one fifth of total household
income, while adding other environmental income brings the share to more than one fourth –
about the same as incomes from growing crops. Environmental resources and agricultural crops
are the two main sources of livelihoods in the survey sites. As expected, forest reliance (share of forest income in total household income) is higher for the poorer income quintiles, but the
differences are less pronounced than what was found in most previous studies. We also find
that safety net and seasonal gap-filling functions may be less important that often assumed.
Ignoring environmental incomes in income surveys and in rural development planning
would in quantitative terms amount to ignoring that farmers grow crops. Agricultural area
expansion into forests and other vegetation types may well come to increase household
incomes, but corresponding income losses from losing forest cover and forest degradation could
be larger than previously assumed. Depriving poor people of access to forest product extraction,
for instance through highly exclusionary conservation policies, could jeopardize the livelihoods
of people depending on these resources
Inheritance patterns in citation networks reveal scientific memes
Memes are the cultural equivalent of genes that spread across human culture
by means of imitation. What makes a meme and what distinguishes it from other
forms of information, however, is still poorly understood. Our analysis of
memes in the scientific literature reveals that they are governed by a
surprisingly simple relationship between frequency of occurrence and the degree
to which they propagate along the citation graph. We propose a simple
formalization of this pattern and we validate it with data from close to 50
million publication records from the Web of Science, PubMed Central, and the
American Physical Society. Evaluations relying on human annotators, citation
network randomizations, and comparisons with several alternative approaches
confirm that our formula is accurate and effective, without a dependence on
linguistic or ontological knowledge and without the application of arbitrary
thresholds or filters.Comment: 8 two-column pages, 5 figures; accepted for publication in Physical
Review
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Crystallographic Anisotropy of Wear on a Polycrystalline Diamond Surface
We correlate topography and diffraction measurements to demonstrate that grain orientation profoundly influences polishing rates in polycrystalline diamond synthesized by chemical vapor deposition. Grains oriented with {l_brace}111{r_brace} or {l_brace}100{r_brace} planes perpendicular to the surface normal polish at significantly lower rates compared with grains of all other orientations when the surface is polished in continuously varying in-plane directions. These observations agree with predictions of the periodic bond chain vector model, developed previously for single crystals, and indicate that the polishing rate depends strongly on the number of PBC vectors that are within 10{sup o} of the exposed surface plane
Association Between Maternal Diabetes in Utero and Age at Offspring's Diagnosis of Type 2 Diabetes
OBJECTIVE—The purpose of this study was to examine age of diabetes diagnosis in youth who have a parent with diabetes by diabetes type and whether the parent's diabetes was diagnosed before or after the youth's birth
The repulsive lattice gas, the independent-set polynomial, and the Lov\'asz local lemma
We elucidate the close connection between the repulsive lattice gas in
equilibrium statistical mechanics and the Lovasz local lemma in probabilistic
combinatorics. We show that the conclusion of the Lovasz local lemma holds for
dependency graph G and probabilities {p_x} if and only if the independent-set
polynomial for G is nonvanishing in the polydisc of radii {p_x}. Furthermore,
we show that the usual proof of the Lovasz local lemma -- which provides a
sufficient condition for this to occur -- corresponds to a simple inductive
argument for the nonvanishing of the independent-set polynomial in a polydisc,
which was discovered implicitly by Shearer and explicitly by Dobrushin. We also
present some refinements and extensions of both arguments, including a
generalization of the Lovasz local lemma that allows for "soft" dependencies.
In addition, we prove some general properties of the partition function of a
repulsive lattice gas, most of which are consequences of the alternating-sign
property for the Mayer coefficients. We conclude with a brief discussion of the
repulsive lattice gas on countably infinite graphs.Comment: LaTex2e, 97 pages. Version 2 makes slight changes to improve clarity.
To be published in J. Stat. Phy
Moral Hazard and Moral Motivation: Corporate Social Responsibility as Labor Market Screening
l=0 to l=1 Transition Form Factors
A method is proposed to extend the hard scattering picture of Brodsky and
Lepage to transitions between hadrons with orbital angular momentum l=0 and
l=1. The use of covariant spin wave functions turns out to be very helpful in
formulating that method. As a first application we construct a light-cone wave
function of the nucleon resonance in the quark-diquark picture.
Using this wave function and the extended hard scattering picture, the
-- transition form factors are calculated at large momentum transfer
and the results compared to experimental data. As a further application of our
method we briefly discuss the -- form factors in an appendix.Comment: 27 pages, 6 PS-figures in uuencoded compressed file, Latex, WU-B
93-29, MZ-TH/93-2
Enhancing Perceived Safety in Human–Robot Collaborative Construction Using Immersive Virtual Environments
Advances in robotics now permit humans to work collaboratively with robots. However, humans often feel unsafe working alongside robots. Our knowledge of how to help humans overcome this issue is limited by two challenges. One, it is difficult, expensive and time-consuming to prototype robots and set up various work situations needed to conduct studies in this area. Two, we lack strong theoretical models to predict and explain perceived safety and its influence on human–robot work collaboration (HRWC). To address these issues, we introduce the Robot Acceptance Safety Model (RASM) and employ immersive virtual environments (IVEs) to examine perceived safety of working on tasks alongside a robot. Results from a between-subjects experiment done in an IVE show that separation of work areas between robots and humans increases perceived safety by promoting team identification and trust in the robot. In addition, the more participants felt it was safe to work with the robot, the more willing they were to work alongside the robot in the future.University of Michigan Mcubed Grant: Virtual Prototyping of Human-Robot Collaboration in Unstructured Construction EnvironmentsPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145620/1/You et al. forthcoming in AutCon.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145620/4/You et al. 2018.pdfDescription of You et al. 2018.pdf : Published Versio
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