Reduced word enumeration, complexity, and randomization

A reduced word of a permutation $w$ is a minimal length expression of $w$ as a product of simple transpositions. We examine the computational complexity, formulas and (randomized) algorithms for their enumeration. In particular, we prove that the Edelman-Greene statistic, defined by S. Billey-B. Pawlowski, is typically exponentially large. This implies a result of B. Pawlowski, that it has exponentially growing expectation. Our result is established by a formal run-time analysis of A. Lascoux-M.-P. Sch\"utzenberger's transition algorithm. The more general problem of Hecke word enumeration, and its closely related question of counting set-valued standard Young tableaux, is also investigated. The latter enumeration problem is further motivated by work on Brill-Noether varieties due to M. Chan-N. Pflueger and D. Anderson-L. Chen-N. Tarasca.Comment: 23 pages. v2: added reference to University of Washington PhD thesis of B. Pawlowski, which proves a stronger version of Theorem 1.

Improved Attending in an 8-Year-Old Boy Diagnosed with Down Syndrome through Teaching with Acoustical Guidance

Skill acquisition can be particularly difficult when prerequisites are lacking (e.g., attending to learning materials) that are necessary to expand academic abilities. However, behavioral technologies exist that can help individuals overcome, or at least improve their quality of life despite these difficulties. The current case study used a quasi-changing-criterions-design to examine the effectiveness of a Teaching with Acoustical Guidance (TAGteach) technique to increase attending to learning materials in an eight-year-old participant with Down syndrome. The TAGteach technique was effective in increasing the percentage of trials in which the participant looked at materials and the duration of looking at presented materials during learning trials. Furthermore, results generalized to a leisure task, showing that the intervention was not only academic, but also has the ability to improve on quality of life

The Unusual 3D Interplay of Basement Fault Reactivation and Fault-Propagation-Fold Development: A Case Study of the Laramide-age Stillwell Anticline, West Texas (USA)

Subsurface fault geometries have a systematic influence on folds formed above those faults. We use the extraordinarily well-exposed fold geometries of the Laramide-age Stillwell anticline in west Texas (USA) to develop a strain-predictive model of fault-propagation fold formation. The anticline is a 10-km long, NW-trending, NE-vergent, asymmetric fold system with an axis that displays a map-view left-stepping, en echelon pattern. We integrated field observations, geologic and structural data, cross-sections, and 2D kinematic modeling to establish an unusual 3D two-stage model of contractional fold formation, including: 1) reverse reactivation of a pre-existing, NW-striking, SW-dipping, left-stepping, en echelon normal fault system in Paleozoic basement rocks to generate monoclinal flexures in overlying layered Cretaceous carbonate rocks; and 2) the formation of a subsequent flat-ramp fault system that propagated horizontally along a mechanically-weak, clay-rich Cretaceous unit before ramping up at the hinge of the pre-existing monocline system. Strain is focused within the forelimb of the system, in front of the propagating fault tip, and is accommodated by a combination of interlayer slip, flat-ramp faulting, and fracturing proximal to planes of slip. This strain predictive model can be applied to similar, less-well-exposed contractional systems worldwide and provides a new, unusual example of Laramide-age contractional deformation

Discrepancies in Written Versus Calculated Durations in Opioid Prescriptions: Pre-Post Study.

BACKGROUND: The United States is in the midst of an opioid epidemic. Long-term use of opioid medications is associated with an increased risk of dependence. The US Centers for Disease Control and Prevention makes specific recommendations regarding opioid prescribing, including that prescription quantities should not exceed the intended duration of treatment. OBJECTIVE: The purpose of this study was to determine if opioid prescription quantities written at our institution exceed intended duration of treatment and whether enhancements to our electronic health record system improved any discrepancies. METHODS: We examined the opioid prescriptions written at our institution for a 22-month period. We examined the duration of treatment documented in the prescription itself and calculated a duration based on the quantity of tablets and doses per day. We determined whether requiring documentation of the prescription duration affected these outcomes. RESULTS: We reviewed 72,314 opioid prescriptions, of which 16.96% had a calculated duration that was greater than what wasdocumented in the prescription. Making the duration a required field significantly reduced this discrepancy (17.95% vs 16.21%,P CONCLUSIONS: Health information technology vendors should develop tools that, by default, accurately represent prescription durations and/or modify doses and quantities dispensed based on provider-entered durations. This would potentially reduce unintended prolonged opioid use and reduce the potential for long-term dependence

Notes for this Special Issue

Residential learning communities or living-learning communities afford integration of and collaboration between academic affairs and student affairs. The articles in this special issue address unique elements and experiences in residential learning community programs

Americans Perceptions of Food Safety: a Comparative Study of Fresh Produce, Beef and Poultry Products

This study examines public perceptions of the safety of fresh produce (spinach and lettuce), beef, and poultry, employing survey data collected during the 2006 nationwide recall of fresh spinach contaminated with E. coli O157:H7. The results show that white respondents perceived all products to be safe. In contrast, young people, people with only a high school education, and those with lower household incomes ($50,000 or below), were more likely to view fresh produce, beef, and poultry as unsafe. Trust in the USDA as well as conventional farmers contributed toward more positive perceptions of spinach and lettuce. Low levels of objective knowledge about foodborne pathogens and resulting illnesses contributed to negative food safety perceptions. Efforts should be directed toward additional public education and outreach about general aspects of food safety, especially targeting youth, low income groups, non-whites, and those with education at or below a high school level

Food Recalls and Food Safety Perceptions: The September 2006 Spinach Recall Case

This paper examines public perceptions on food safety particularly relating to spinach, which was subject of countrywide recall in 2006. Results indicate that food safety perceptions may be driven by public trust/confidence in institutions whose activities may be directly or indirectly related to food safety. The results further suggest that food safety perceptions may also be related to the type of the product; for example, the public perceives frozen spinach differently from bagged fresh spinach. Additionally, the results show that low levels of objective knowledge about food pathogens and the resulting illnesses have implications on overall food safety. Results further indicate that females and Caucasians perceived the four types of spinach as safe for consumption. This outcome contrasts with views held by young people, people with education below high school and those belonging to the lower incomes groups, who viewed the four types of spinach as unsafe. More attention should be directed toward public education and outreach efforts on overall food safety targeting the youth, low income groups and those with education below high school. In addition, there is need for the regulatory agencies to put their act together, given current low levels of public trust in their role of safeguarding the food supply.Food Consumption/Nutrition/Food Safety,

Food Recalls and Food Safety Perceptions: The September 2006 Spinach Recall Case

This study analyzes public perceptions of food safety using a national survey conducted in November 2006, soon after the September 2006 nationwide spinach recall. We explore relationships between peoples’ perceived risks of food contamination (spinach in this case) and their trust in the institutions in charge of safeguarding/ensuring safety. Finally, we examine relationships between individual observance of basic good food handling practices and food safety. Trust in institutions through which food passes and regulatory agencies were shown to be critical in determining food safety perceptions. For example, confidence in the USDA as a regulatory agent was viewed positively, and hence contributed toward viewing the four types of spinach as safe for consumption. Conversely, skepticism with which the public views food corporations (processors, transporters, or retailers) impacted food safety perceptions negatively.food recalls, food safety, public perceptions, spinach, Agribusiness, Food Consumption/Nutrition/Food Safety,