1,050 research outputs found
Missing the Outbreak for the Germs: Institutionalized Non-Knowledge and Industrial Power in Agrofood Safety Governance
Leafy greens cause a growing proportion of foodborne illness outbreaks despite heavy investment in surveillance technologies designed to control pathogenic hazards in agriculture. To understand how the governing regime maintains authority despite continual lapses in control, I examine a deadly 2018 outbreak of Escherichia coli O157: H7 linked to romaine lettuce. By comparing the outbreak investigation and regulatory response to the questions not asked and actions not taken, I show how the regime’s methods of understanding the outbreak also organized its ignorance of dangers outside its carefully constructed field of vision. Applying agnotology theory, I argue that the industrial organization of leafy greens agriculture and the institutionalized non-knowledge of emergent social–ecological vulnerabilities coproduce one another, allowing the industrial food regime to avoid fundamental reforms that might enhance resilience. This case demonstrates that critical examination of organized non-knowledge in complex environmental governance systems can reveal limits to institutional learning and systemic reflexivity that impede sustainability transitions
Getting Cars Off the Road: The Cost-Effectiveness of an Episodic Pollution Control Program
Ground level ozone remains a serious problem in the United States. Because ozone non-attainment is a summer problem, episodic rather than continuous controls of ozone precursors are possible. We evaluate the costs and effectiveness of an episodic scheme that requires people to buy permits in order to drive on high ozone days. We estimate the demand function for permits based on a survey of 1,300 households in the Washington, DC metropolitan area. Assuming that all vehicle owners comply with the scheme, the permit program would reduce VOCs by 50 tons and NOx by 42 tons per Code Red day at a permit price of 9 million (2008 USD). This compares favorably with permanent methods of reducing VOCs that cost $645 per ton per year.Ground-Level Ozone, Episodic Pollution Control Schemes, Mobile Sources, Volatile Organic Compounds (Vocs), Cost Per Ton of Vocs Removed
Unification of Flavor, CP, and Modular Symmetries
Flavor symmetry plays a crucial role in the standard model of particle
physics but its origin is still unknown. We develop a new method (based on
outer automorphisms of the Narain space group) to determine flavor symmetries
within compactified string theory. A picture emerges where traditional
(discrete) flavor symmetries, CP-like symmetries and modular symmetries (like
T-duality) of string theory combine to unified flavor symmetries. The groups
depend on the geometry of compact space and the geographical location of fields
in the extra dimensions. We observe a phenomenon of "local flavor groups" with
potentially different flavor symmetries for the various sectors of quarks and
leptons. This should allow interesting connections to existing bottom-up
attempts in flavor model building.Comment: 18 pages, 3 figures; v2: minor changes, version accepted by PL
Understanding the bio-physical characteristics of a fen ecosystem to inform management and conserve the rare habitat
Fen-wetland ecosystems are rare nationwide. Their unique groundwater regime and chemistry, along with a floating, vegetated peat mat that may occur, support diverse and rare plant and wildlife communities. A fen’s ecological benefits are considered even greater within an urbanized setting through its natural attenuation of runoff and pollutants, though these ecosystem services may diminish should the urban-sourced impacts eventually alter the fen’s bio-physical condition. Here we will present how determining a fen’s key bio-physical factors and understanding their combined sensitivity to external processes is necessary to define and address potential threats to a fen’s conservation.
Located within a 100-acre Metro-owned natural area along the lower Willamette River, the last known remaining fen composed of a groundwater-fed lake with a densely vegetated floating peat mat in the region is vulnerable to threats that could alter its fragile biochemistry. Threats include stormwater runoff, groundwater reductions from local pumping, nutrient input from septic tanks, and invasive species. To inform conservation measures, Metro’s goal was to assess the fen’s watershed inputs and bio-physical condition by studying the site hydrology, water and soil quality, and vegetation. Initial results reveal a unique ecosystem with counter groundwater and surface-water flow directions due to the unique geologic setting, eutrophic lake conditions from high nutrient loading and concentration, acidic water chemistry and soils from parent bedrock materials, and a diverse plant community consisting of 27 taxa of rare plants. Ongoing monitoring of the fen is helping to assess its condition, help detect future trends, and inform preservation of this unique habitat and potential recommendations for restoring disturbed fens elsewhere in the region
A String Theory of Flavor and CP
Modular transformations of string theory (including the well-known stringy
dualities) play a crucial role in the discussion of discrete flavor symmetries
in the Standard Model. They are at the origin of CP transformations and provide
a unification of CP with traditional flavor symmetries. Here, we present a
novel, fully systematic method to reliably compute the unified flavor symmetry
of the low-energy effective theory, including enhancements from the modular
transformations of string theory. The unified flavor group is non-universal in
moduli space and exhibits the phenomenon of "Local Flavor Unification" where
different sectors of the theory can be subject to different flavor structures.Comment: 38 pages, 2 figure
FAPRI U.S. Crops Model Documentation
The U.S. crops model is one component of the integrated modeling system developed and maintained by the Food and Agricultural Policy Research Institute (FAPRI), which operates as a joint program at Iowa State University and the University of Missouri-Columbia. The FAPRI system is used to generate medium-term projections of the agricultural economy and to conduct policy analysis. The U.S. crops model determines domestic supply, utilization, and prices for wheat, corn, sorghum, oats, barley, soybeans, soybean meal, soybean oil, rice, and cotton, Other components of the FAPRI system include world trade models for grains and oilseeds, domestic livestock models, and satellite models that determine U.S. net farm income and the government cost of agricultural programs
The first string-derived eclectic flavor model with realistic phenomenology
Eclectic flavor groups arising from string compactifications combine the
power of modular and traditional flavor symmetries to address the flavor
puzzle. This top-down scheme determines the representations and modular weights
of all matter fields, imposing strict constraints on the structure of the
effective potential, which result in controlled corrections. We study the
lepton and quark flavor phenomenology of an explicit, potentially realistic
example model based on a T6/Z3xZ3 orbifold compactification of the heterotic
string that gives rise to an Omega(2) eclectic flavor symmetry. We find that
the interplay of flavon alignment and the localization of the modulus in the
vicinity of a symmetry-enhanced point leads to naturally protected fermion mass
hierarchies, favoring normal-ordered neutrino masses arising from a see-saw
mechanism. We show that our model can reproduce all observables in the lepton
sector with a small number of parameters and deliver predictions for so far
undetermined neutrino observables. Furthermore, we extend the fit to quarks and
find that Kaehler corrections are instrumental in obtaining a successful
simultaneous fit to the quark and lepton sectors.Comment: 28 pages + appendices, 7 figures, 7 tables; v2: references added,
discussion extended, typos in app. C corrected, results unchanged, matches
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