13,932 research outputs found
Understanding Federalism and U.S. Fluoridation Policy: The Policy Landscape of U.S. Fluoridation Policy
In 2015, the Federal Panel on Community Water Fluoridation finalized a recommendation setting a fixed 0.7 mg/L optimal water fluoridation level for the United States. The announcement was made in the Federal Register in 2011 and allowed for a period of public comment and scientific review before being finalized. Since the original 1962 optimal range recommendation, community water fluoridation has been a decentralized policy environment allowing for local decision-making in setting water fluoridation levels. The finalized 2015 policy recommendation attempts to centralize policy decision-making to reduce the risk of overexposure while maintaining decentralized implementation. This dissertation addresses the following research question: Why is U.S. fluoridation policy implemented in a decentralized rather than a centralized fashion? The research uses a policy cycle framework approach to understanding the water fluoridation policy process and identifies potential problems with a central policy recommendation in a decentralized policy environment and explores policy alternatives. A mixed methodology was used to analyze the policy formulation and implementation stages of the policy process. A quantitative analysis was utilized to understand policy implementation at the local level. Results indicate that the recommendation was likely effective in narrowing the variability of fluoridation levels. Further, the 0.7 mg/L recommendation was likely met since the policy change. A qualitative analysis addressed potential missed opportunities during the formulation stage of the policy process. Analysis revealed: positive results in stakeholder perceptions of engagement and in meeting the recommendation, a slight preference for state policy recommendations, and mixed results for exploring alternate models, equitability of implementation, and consumer opt-out options
Disturbances of Plant Communities : Spruce Bark Beetle Infestation
The spruce bark beetle (Dendroctonus rufipennis) is not new to the area, nor is it the only insect to affect the region\u27s forests. Epidemic scale outbreaks are known to have occurred on the lower Kenai Peninsula as far back as the mid-1800s. The recent epidemic, however, has certainly been the most significant terrestrial ecological disturbance to the area in recorded history (Wittwer et al. 1998). Notable outbreaks were not noted in the Kachemak Bay Watershed until the 1950s and early 1960s when the first outbreak was observed near Anchor Point. At approximately the same time, beetle outbreaks were growing outside of the Watershed. An extended period of drought is thought to have contributed to the surge in outbreaks by reducing trees\u27 ability to resist and recover from beetle attack. Increased rainfall in the late 1960s, however, dampened the drought conditions, curtailing a more widespread epidemic. By the late 1970s, beetle outbreaks had skyrocketed again on the Kenai Peninsula. Despite this outbreak, the Kachemak Bay Watershed remained healthy until 1984 when an outbreak in the Fox River drainage began to expand, and beetles commenced consuming forests along East Road on the northern side of the Bay. Meanwhile, a small infestation in Mallard Bay, on the southern side of the Watershed, expanded to 12,000 acres by 1988. In addition, more outbreaks were developing to the north of Homer, near Ninilchik and Crooked Creek. There was some thought that the maritime climate of the Bay area would keep the outbreaks from expanding throughout the area, but this was not to be the case
Water Users’ Perspectives: Summary of Withdrawal Survey Responses and Commentary
The state of South Carolina is currently in a multiyear process of updating the State Water Plan, and water demand projections are an important component of that work. Predictions of water demand are inherently uncertain, but perhaps they can benefit from input by a diverse and robust sample of water users. A brief survey regarding water use was distributed to 780 permitted and registered water users in the state, including all water suppliers, industries, and irrigators withdrawing more than 3 million gallons in a month or more than 100,000 gallons in a day. There are 316 responses to 10 quantitative survey items that are summarized, presented, and discussed. Results indicate that most respondents plan to maintain their current levels of water use, consider their withdrawal reports to be accurate within 10%, and believe their current water supplies to be critical to their enterprise. A qualitative review of comments noted on survey responses includes a variety of potential drivers of water demand. The results motivate a discussion of recommendations for future research
Smallholder Participation in Agricultural Value Chains: Comparative Evidence from Three Continents
Supermarkets, specialized wholesalers, and processors and agro-exporters’ agricultural value chains have begun to transform the marketing channels into which smallholder farmers sell produce in low-income economies. We develop a conceptual framework through which to study contracting between smallholders and a commodity-processing firm. We then conduct an empirical meta-analysis of agricultural value chains in five countries across three continents (Ghana, India, Madagascar, Mozambique, and Nicaragua). We document patterns of participation, the welfare gains associated with participation, reasons for non-participation, the significant extent of contract non-compliance, and the considerable dynamism of these value chains, as farmers and firms enter and exit frequently.
Molecular Star Formation Rate Indicators in Galaxies
We derive a physical model for the observed relations between star formation
rate (SFR) and molecular line (CO and HCN) emission in galaxies, and show how
these observed relations are reflective of the underlying star formation law.
We do this by combining 3D non-LTE radiative transfer calculations with
hydrodynamic simulations of isolated disk galaxies and galaxy mergers. We
demonstrate that the observed SFR-molecular line relations are driven by the
relationship between molecular line emission and gas density, and anchored by
the index of the underlying Schmidt law controlling the SFR in the galaxy.
Lines with low critical densities (e.g. CO J=1-0) are typically thermalized and
trace the gas density faithfully. In these cases, the SFR will be related to
line luminosity with an index similar to the Schmidt law index. Lines with high
critical densities greater than the mean density of most of the emitting clouds
in a galaxy (e.g. CO J=3-2, HCN J=1-0) will have only a small amount of
thermalized gas, and consequently a superlinear relationship between molecular
line luminosity and mean gas density. This results in a SFR-line luminosity
index less than the Schmidt index for high critical density tracers. One
observational consequence of this is a significant redistribution of light from
the small pockets of dense, thermalized gas to diffuse gas along the line of
sight, and prodigious emission from subthermally excited gas. At the highest
star formation rates, the SFR-Lmol slope tends to the Schmidt index, regardless
of the molecular transition. The fundamental relation is the Kennicutt-Schmidt
law, rather than the relation between SFR and molecular line luminosity. We use
these results to make imminently testable predictions for the SFR-molecular
line relations of unobserved transitions.Comment: ApJ Accepted - Results remain same as previous version. Content
clarified with Referee's comment
Stakeholder Engagement: Methods of Inclusion in South Carolina State Water Plan Decision-Making
Stakeholder engagement in natural resource planning has become increasingly important at local and state levels. Including stakeholders in decision-making can increase buy-in and public support of final regional and state recommendations. It can also lead to policy change and improved implementation outcomes resulting from these planning processes. South Carolina is developing a stakeholder-driven water plan, although it is several years away from being finalized. The methods used in this process are a departure from past efforts. Stakeholder inclusion in decision-making in the water planning process is described and analyzed in this article. The focus is on the specific phases of the process and the methods of inclusion used or those anticipated to be used. In this cycle, stakeholder involvement in decisions range from informational/advisory to consultative to decision-making
Intestinal barrier tightening by a cell-penetrating antibody to Bin1, a candidate target for immunotherapy of ulcerative colitis.
Patients afflicted with ulcerative colitis (UC) are at increased risk of colorectal cancer. While its causes are not fully understood, UC is associated with defects in colonic epithelial barriers that sustain inflammation of the colon mucosa caused by recruitment of lymphocytes and neutrophils into the lamina propria. Based on genetic evidence that attenuation of the bridging integrator 1 (Bin1) gene can limit UC pathogenicity in animals, we have explored Bin1 targeting as a therapeutic option. Early feasibility studies in the dextran sodium sulfate mouse model of experimental colitis showed that administration of a cell-penetrating Bin1 monoclonal antibody (Bin1 mAb 99D) could prevent lesion formation in the colon mucosa in part by preventing rupture of lymphoid follicles. In vivo administration of Bin1 mAb altered tight junction protein expression and cecal barrier function. Strikingly, electrophysiology studies in organ cultures showed that Bin1 mAb could elevate resistance and lowe
Smallholder Participation in Agricultural Value Chains: Comparative Evidence from Three Continents
Supermarkets, specialized wholesalers, and processors and agro-exporters’ agricultural value chains have begun to transform the marketing channels into which smallholder farmers sell produce in low-income economies. We develop a conceptual framework through which to study contracting between smallholders and a commodity-processing firm. We then conduct an empirical meta-analysis of agricultural value chains in five countries across three continents (Ghana, India, Madagascar, Mozambique, and Nicaragua). We document patterns of participation, the welfare gains associated with participation, reasons for non-participation, the significant extent of contract non-compliance, and the considerable dynamism of these value chains, as farmers and firms enter and exit frequently.Agricultural Value Chains, Contract Farming, Africa, Asia, Latin America
Intermultiplet transitions and magnetic long-range order in Sm-based pyrochlores
We present bulk and neutron scattering measurements performed on the
isotopically enriched and
samples. Both compounds display sharp heat
capacity anomalies, at 350 mK and 440 mK, respectively. Inelastic neutron
scattering measurements are employed to determine the crystalline electric
field (CEF) level scheme, which includes transitions between the ground-state
and first excited multiplets of the ion. To further
validate those results, the single-ion magnetic susceptibility of the compounds
is calculated and compared with the experimental DC-susceptibility measured in
low applied magnetic fields. It is demonstrated that the inclusion of
intermultiplet transitions in the CEF analysis is fundamental to the
understanding of the intermediate and, more importantly, low temperature
magnetic behaviour of the Sm-based pyrochlores. Finally, the heat capacity
anomaly is shown to correspond to the onset of an all-in-all-out long-range
order in the stannate sample, while in the titanate a dipolar long-range order
can be only indirectly inferred.Comment: 13 pages, 10 Figure
High Statistics Analysis using Anisotropic Clover Lattices: (I) Single Hadron Correlation Functions
We present the results of high-statistics calculations of correlation
functions generated with single-baryon interpolating operators on an ensemble
of dynamical anisotropic gauge-field configurations generated by the Hadron
Spectrum Collaboration using a tadpole-improved clover fermion action and
Symanzik-improved gauge action. A total of 292,500 sets of measurements are
made using 1194 gauge configurations of size 20^3 x 128 with an anisotropy
parameter \xi= b_s/b_t = 3.5, a spatial lattice spacing of b_s=0.1227\pm 0.0008
fm, and pion mass of m_\pi ~ 390 MeV. Ground state baryon masses are extracted
with fully quantified uncertainties that are at or below the ~0.2%-level in
lattice units. The lowest-lying negative-parity states are also extracted
albeit with a somewhat lower level of precision. In the case of the nucleon,
this negative-parity state is above the N\pi threshold and, therefore, the
isospin-1/2 \pi N s-wave scattering phase-shift can be extracted using
Luescher's method. The disconnected contributions to this process are included
indirectly in the gauge-field configurations and do not require additional
calculations. The signal-to-noise ratio in the various correlation functions is
explored and is found to degrade exponentially faster than naive expectations
on many time-slices. This is due to backward propagating states arising from
the anti-periodic boundary conditions imposed on the quark-propagators in the
time-direction. We explore how best to distribute computational resources
between configuration generation and propagator measurements in order to
optimize the extraction of single baryon observables
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