15,771 research outputs found
Transitions of social-ecological subsistence systems in the Arctic
Transitions of social-ecological systems (SES) expose governance systems
to new challenges. This is particularly so in the Arctic where resource systems
are increasingly subjected to global warming, industrial development and globalization
which subsequently alter the local SES dynamics. Based on common-pool
resource theory, we developed a dynamic conceptual model explaining how exogenous
drivers might alter a traditional subsistence system from a provisioning to
an appropriation actions situation. In a provisioning action situation the resource
users do not control the resource level but adapt to the fluctuating availability of
resources, and the collective challenge revolve around securing the subsistence in
the community. An increased harvest pressure enabled by exogenous drivers could
transform the SES to an appropriation action situation where the collective challenge
has changed to avoid overuse of a common-pool resource. The model was
used as a focal lens to investigate the premises for broad-scale transitions of subsistence-oriented
SESs in Arctic Alaska, Canada and Greenland. We synthesized
data from documents, official statistics and grey and scientific literature to explore
the different components of our model. Our synthesis suggests that the traditional
Arctic subsistence SESs mostly comply with a provisioning action situation.
Despite population growth and available technology; urbanization, increased wage
labor and importation of food have reduced the resource demand, and we find no
evidence for a broad-scale transition to an appropriation action situation throughout
the Western Arctic. However, appropriation challenges have emerged in some
cases either as a consequence of commercialization of the resource or by severely
reduced resource stocks due to various exogenous drivers. Future transitions of
SESs could be triggered by the emergence of commercial local food markets and
Arctic warming. In particular, Arctic warming is an intensifying exogenous driver
that is threatening many important Arctic wildlife resources inflicting increased
appropriation challenges to the governance of local harvest.Ye
Inflatable stretcher to transport patients
Inflatable plastic bag inside strong, inflexible outer bag facilitates emergency transport of seriously burned or disabled patients. When the bag is inflated the patient is completely immobilized and cushioned from external shock. Air for breathing, temperature controls and communications may be provided by appropriate plug-in connections
Antiproton-nucleus potentials from global fits to antiprotonic X-rays and radiochemical data
We report on global fits of optical-model parameters to 90 data points for
X-rays and 17 data points of radiochemical data put together. With the
help of separate fits to the two kinds of data it is possible to determine
phenomenologically the radial region where the absorption of antiprotons takes
place and to obtain neutron densities which represent the average behaviour
over the periodic table. A finite-range attractive and absorptive -nuclear isoscalar potential fits the data well. Self-consistent dynamical
calculations within the RMF model demonstrate that the polarization of the
nucleus by the {\it atomic} antiproton is negligible.Comment: 18 pages, 6 figures, one table. Extended discussion, to appear in
Nucl. Phys.
Deciphering and modeling the physicochemical drivers of denitrification rates in bioreactors
AbstractDenitrification bioreactors have served as effective artificial N sinks by stimulating denitrification and remediating excessive nitrate. Predictions on bioreactor performance will be improved by quantifying the relationship between denitrification rates and causal factors which vary by geography (temperature), land-use intensity (NO3 concentration) and media type (carbon quality, quantity, and surface area). Experimental mesocosms filled with different wood media types (oak, pine), particle sizes and wood–sand volume ratios were exposed to flowing high-nitrate groundwater across a range of seasonal groundwater temperatures (8–24°C) to determine the influence of these coarse but utilitarian parameters on bioreactor performance. To increase the transferability and specificity of findings, a multivariate analysis was used to quantify relationships between denitrification rates, microbial biomass, temperature, media surface area to volume ratio and metrics of C quality to guide de novo media selection and performance predictions. There were no strong differences in hydraulic conductivity, media consumption rates, and TKN flux between different treatments although increasing the wood–sand volume ratio alone produced significant increases in denitrification rates and undesirable DOC leaching. Fluxes of DOC and TKN also increased with higher hydraulic loading rates. Denitrification rates were unresponsive to nitrate concentration and most strongly influenced by groundwater temperature (Q10=4.7), although carbon bioavailability and media surface area were uniquely predictive of denitrification rates. Bioreactor performance will therefore be most strongly influenced by geographical variations in temperature, although within a specific location, bioreactor media selection will influence denitrification rates
Best Practices for Commercial Vehicle Monitoring Facilities Design
The great technological advances that were made over the last decade in monitoring traffic and the increased emphasis on highway safety for truck traffic have prompted a need to determine more effective ways to monitor and inspect truck traffic. Commercial Vehicle Monitoring (CVM) facilities provide the highway community with the means of supervising truck traffic. However, in an era with limited funds and space for roadway expansion. some consideration must be given to the types of facilities needed and the most efficient way to spend the available funds. Hence, a research study was initiated to determine the successful practices for designing a new CVM facility or retrofitting or upgrading an existing facility; the findings are presented here. A questionnaire was distributed to all 50 states to identify the state of the nation with respect to the newly constructed and lately upgraded CVM facilities. This report focuses on the presentation of issues that need to be considered and addressed when designing or upgrading a CVM facility and provides a checklist of critical factors, considerations for facility components, and typical facility layouts
Electrically-detected magnetic resonance in ion-implanted Si:P nanostructures
We present the results of electrically-detected magnetic resonance (EDMR)
experiments on silicon with ion-implanted phosphorus nanostructures, performed
at 5 K. The devices consist of high-dose implanted metallic leads with a square
gap, into which Phosphorus is implanted at a non-metallic dose corresponding to
10^17 cm^-3. By restricting this secondary implant to a 100 nm x 100 nm region,
the EDMR signal from less than 100 donors is detected. This technique provides
a pathway to the study of single donor spins in semiconductors, which is
relevant to a number of proposals for quantum information processing.Comment: 9 pages, 3 figure
Transformational Mentoring: An Experimental Process for Aligning Student Learning with Business Realities
The purpose of this paper is to describe an experimental student learning process, document preliminary efforts to assess the learning outcomes, and suggest avenues for future research. The primary objective of the approach was to significantly increase student learning through the implementation of transformational mentoring techniques. These techniques were applied as students worked with an actual business in an effort to improve its market position and revenue
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