1,764 research outputs found
Unequal Error Protection Querying Policies for the Noisy 20 Questions Problem
In this paper, we propose an open-loop unequal-error-protection querying
policy based on superposition coding for the noisy 20 questions problem. In
this problem, a player wishes to successively refine an estimate of the value
of a continuous random variable by posing binary queries and receiving noisy
responses. When the queries are designed non-adaptively as a single block and
the noisy responses are modeled as the output of a binary symmetric channel the
20 questions problem can be mapped to an equivalent problem of channel coding
with unequal error protection (UEP). A new non-adaptive querying strategy based
on UEP superposition coding is introduced whose estimation error decreases with
an exponential rate of convergence that is significantly better than that of
the UEP repetition coding introduced by Variani et al. (2015). With the
proposed querying strategy, the rate of exponential decrease in the number of
queries matches the rate of a closed-loop adaptive scheme where queries are
sequentially designed with the benefit of feedback. Furthermore, the achievable
error exponent is significantly better than that of random block codes
employing equal error protection.Comment: To appear in IEEE Transactions on Information Theor
Cigarette smoking and food insecurity among low-income families in the United States, 2001
The goal of this research is to quantify the association between food insecurity and smoking among low-income families. This analysis is a retrospective study using data from the 2001 Panel Study of Income Dynamics, a longitudinal study of a representative sample of U.S. men, women, and children and the family units in which they reside. Family income is linked with U.S. poverty thresholds to identify 2,099 families living near or below 200 percent of the federal poverty level. Food insecurity (that is, having insufficient funds to purchase enough food to maintain an active and healthy lifestyle) is calculated from the eighteen core items in the food security module of the U.S. Department of Agriculture. The results indicate that smoking prevalence is higher among low-income families who are food insecure compared to low-income families who are food secure (43.6 percent versus 31.9 percent). Multivariate analysis reveals that smoking is associated with an increase in food insecurity of approximately 6 percentage points. Given our finding that families near the federal poverty level spend a large share of their income on cigarettes, perhaps it would be prudent for food assistance and tobacco control programs to work together to help low-income people quit smoking.
THE EFFECT OF GENERIC DAIRY ADVERTISING ON THE HOUSEHOLD DEMAND FOR MILK AND CHEESE
Consistent two-step censored estimation is applied to household demand equations for disaggregated milk and cheese products. The long-run advertising elasticity for total milk was positive, largely due to low fat milk; however the elasticity for cheese was not significant, and only shredded cheese had a positive, significant response.censored regression, household demand, generic advertising, Consumer/Household Economics, Demand and Price Analysis, Marketing,
IDENTIFYING THE EFFECTS OF GENERIC ADVERTISING ON THE HOUSEHOLD DEMAND FOR FLUID MILK AND CHEESE: A TWO-STEP PANEL DATA APPROACH
A two-step model with sample selection is applied to panel data of U.S. households to estimate at-home demand for fluid milk and cheese, incorporating advertising expenditures. The model consistently accounts for sample-selection bias, unobserved household heterogeneity, and temporal correlation. Generic advertising programs for fluid milk and cheese were effective at increasing conditional purchase quantities, with very little effect on the probability of purchase. In contrast to aggregate studies, the long-run generic advertising elasticities for cheese were larger than for those of fluid milk. Advertising response varied considerably across sub-product classes, while branded advertising expenditures were largely insignificant.Demand and Price Analysis, Marketing,
Piezocone Penetration Testing Device
Hydraulic characteristics of soils can be estimated from piezocone penetration test (called PCPT
hereinafter) by performing dissipation test or on-the-fly using advanced analytical techniques. This
research report presents a method for fast estimation of hydraulic conductivity of overconsolidated soils
based on the piezocone penetration test. The method relies on an existing relationship developed for the
determination of hydraulic conductivity of normally consolidated soils on-the-fly. The present research
revises this relationship so that it can be applied for overconsolidated soils by incorporating a proper
correction equation. The revised relationship provides a pore pressure representing the hydraulic
conductivity of a hypothetical “equivalent normally consolidated soil”. The revised relationship was
developed with piezocone indices (Qt, Fr, and Bq) based on well documented laboratory test and PCPT
data. In this regard, PCPT data from Nebraska Department of Transportation (NDOT) was used as a
primary data base to determine the correction equation. Then, the proposed revised relationship was
verified for other sites in the USA, Canada, and South Korea. This study showed that the proposed
method provides a reasonably good prediction of hydraulic conductivity of overconsolidated soils. In
addition, the method also accurately predicted the hydraulic conductivity of normally consolidated soils
Progress toward the Enantioselective Synthesis of Curcusones A–D via a Divinylcyclopropane Rearrangement Strategy
We report our iterative efforts toward the divergent total syntheses of curcusones A–D via Suzuki coupling, intramolecular cyclopropanation, and a key divinylcyclopropane rearrangement. Progress of our synthesis was repeatedly challenged by the highly substrate-dependent cyclopropanation step, which we could ultimately overcome by judicious choice of substituents on the six-membered ring fragment
Experience with key indicator cases among otolaryngology residents
Objective
To describe the resident experience with respect to key indicator cases for each year of training. Study Design
Multi‐institution, cross‐sectional assessment. Methods
Using an electronic survey, current otolaryngology residents were solicited to complete a survey regarding their experiences with the key indicator cases to that point. The survey was sent to this cohort in the winter of 2017–2018. Results
Three hundred and three residents responded, with 293 completing the survey. Twenty‐three percent were PGY1, 19% PGY2, 21% PGY3, 18% PGY4, and 19% PGY5 or higher. The majority of residents progress from resident assistant as a PGY2, to resident surgeon as a PGY3 and self‐assessed competent surgeon as a PGY4 for the majority of the key indicator cases. Less than 50% of the surveyed PGY5 residents had reached independent practice in all the key indicator cases, with stapedectomy (16%), rhinoplasty (18%), and paramedian forehead flap (14.5%) being the cases least frequently performed independently. Ninety‐five percent of the respondent residents felt their program provided adequate training, but 20% of the respondents were either unsure or believed that they would be unable to perform all the key indicator cases by the completion of their training. Conclusions
The majority of otolaryngology residents feel confident in their training, but experience with certain cases lags behind and may not currently be taught as resident level cases. These findings raise the question of whether the current key indicator cases are the best option for assessing breadth and depth of residency training. Level of Evidence
N
Removal of toxic contaminates from polluted soil and water via bioremediation utilizing bacillus spores [abstract]
Atrazine, a widely used herbicide in North America, is one of the known pollutants that pose a potential threat to human health. The addition of naturally occurring degradative bacteria that can remediate these pollutants has been promising. The soil bacterium Pseudomonas sp. strain ADP produces the enzyme AtzA which modifies atrazine to the benign hydroatrazine. However, the current use of bacteria in bioremediation is limited. These bacteria need to compete for nutrients with the native populations of microorganisms in the contaminated soil to survive and to maintain a degradative population. Bacterial endospores are naturally resistant to harmful environments, such as acidic soil, heat, and dessication; and have the ability to persist in soil for long periods of time. We wanted to utilize the Bacillus spore as a vehicle to deliver degradative enzymes, such as AtzA, into the soil and allow the tethered enzymes to persist over time. We utilized two methods for the tethering of enzymes to the spore surface. The first method being a genetic fusion of degradative enzymes to the exosporium of Bacillus endospores, and the second method being a chemical linkage to the outer layers of the Bacillus exosporium. INVENTOR(S): Brian M. Thompson; George C. Stewart; and Chun-Ho Lin CONTACT INFO: Harriet F. Francis, MS; J.D.; [email protected]; 573.884.0374 Per Stromhaug, Ph.D., MBA; [email protected]; 573.884.355
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