17,636 research outputs found
Decomposing labeled interval orders as pairs of permutations
We introduce ballot matrices, a signed combinatorial structure whose
definition naturally follows from the generating function for labeled interval
orders. A sign reversing involution on ballot matrices is defined. We show that
matrices fixed under this involution are in bijection with labeled interval
orders and that they decompose to a pair consisting of a permutation and an
inversion table. To fully classify such pairs, results pertaining to the
enumeration of permutations having a given set of ascent bottoms are given.
This allows for a new formula for the number of labeled interval orders
Bayesian nonparametric multivariate convex regression
In many applications, such as economics, operations research and
reinforcement learning, one often needs to estimate a multivariate regression
function f subject to a convexity constraint. For example, in sequential
decision processes the value of a state under optimal subsequent decisions may
be known to be convex or concave. We propose a new Bayesian nonparametric
multivariate approach based on characterizing the unknown regression function
as the max of a random collection of unknown hyperplanes. This specification
induces a prior with large support in a Kullback-Leibler sense on the space of
convex functions, while also leading to strong posterior consistency. Although
we assume that f is defined over R^p, we show that this model has a convergence
rate of log(n)^{-1} n^{-1/(d+2)} under the empirical L2 norm when f actually
maps a d dimensional linear subspace to R. We design an efficient reversible
jump MCMC algorithm for posterior computation and demonstrate the methods
through application to value function approximation
What My Muffin Top Has To Say To You
My name is Hannah, and I have a confession to make. I hate working out—none of that sweat, panting, exhaustion, and sore muscles for me, no thank you. I’m embarrassed to go to a gym because I assume that everyone judges my speed, pacing, and weight lifting. I try to encourage myself by shopping for brightly colored running shorts and funky sports bras, but, honestly, it’s a fruitless endeavor. Because at the end of the day, I just don’t like to exercise.
So why do I do it?
Because I want to be skinny. [excerpt
Diagnosis and management of eosinophilic asthma: a US perspective.
Eosinophilic asthma is now recognized as an important subphenotype of asthma based on the pattern of inflammatory cellular infiltrate in the airway. Eosinophilic asthma can be associated with increased asthma severity, atopy, late-onset disease, and steroid refractoriness. Induced sputum cell count is the gold standard for identifying eosinophilic inflammation in asthma although several noninvasive biomarkers, including fractional exhaled nitric oxide and periostin, are emerging as potential surrogates. As novel therapies and biologic agents become increasingly available, there is an increased need for specific phenotype-directed treatment strategies. Greater recognition and understanding of the unique immunopathology of this asthma phenotype has important implications for management of the disease and the potential to improve patient outcomes. The present review provides a summary of the clinical features, pathogenesis, diagnosis, and management of eosinophilic asthma
Gen X and Digital Games: Looking back to look forward
Despite there being increased attention in recent years to older adults who actively play digital games, it seems that there has been comparatively minimal scholarly focus on the next generation of older adult gamers – Generation X gamers. Although there have been few, current audience studies that examine this population within a gaming context, a temporal perspective reveals another story. Older members of this generation were the first age cohort to be exposed to and engage in video gameplay at an early age (i.e., childhood). With the emerging popularity of video games in the 1980s, this did not escape the attention of scholars. This study provides an overview of those early studies that assessed video game use and its potential (for better or worse) among the older members Gen X. The study themes identified include: health, education, and behavior. In addition, the first studies that identified gaming characteristics of this generation in their formative years emerged in the latter half of that decade. By identifying themes in these early studies, scholars have the potential to track an entire generation’s gaming history and characteristics from childhood to present day. Ultimately, this may glean richer insight into those qualities when they become the next older generation of digital game players
Diurnal and Seasonal Activity Patterns of Drosophilid Species (Diptera: Drosophilidae) Present in Blackberry Agroecosystems With a Focus on Spotted-Wing Drosophila
Drosophilid species with different life histories have been shown to exhibit similar behavioral patterns related to locating and utilizing resources such as hosts, mates, and food sources. Drosophila suzukii (Matsumura) is an invasive species that differs from other frugivorous drosophilids in that females lay eggs in ripe and ripening fruits instead of overripe or rotten fruits. We hypothesized that there may be diurnal and/or seasonal patterns associated with the movement of drosophilid species into and out of crop fields and their attraction to fermentation-odor-based monitoring traps, and that D. suzukii would conform to similar patterns. To test these hypotheses, we deployed passive, 2-headed Malaise traps between crop fields and wooded edges to simultaneously catch flies moving into and out of crop fields. We also deployed monitoring traps with a fermentation-based bait between crop fields and wooded edges and within crop rows. Traps were deployed weekly in June–August in 2014 and 2015 at two commercial blackberry farm in Cleveland County, NC, and were checked hourly for 24 h, except during darkness. Both D. suzukii and other drosophilid species moved between crop fields and wooded edges and were attracted to monitoring traps primarily during the morning and evening hours. Whereas other drosophilids were captured in traps throughout the season, few D. suzukii were caught in traps until early to mid-July in both years and increased as the season progressed. Understanding D. suzukii movement and activity patterns is essential for the development of effective management strategies
Survival and Phenology of \u3ci\u3eAgrilus Planipennis\u3c/i\u3e (Coleoptera: Buprestidae) Reared on a Newly Developed Artificial Diet Free of Host Material
The final phase in the development of an artificial diet that contains no ash host material and the phenology of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Bupresidae) on that diet are documented. A diet containing powdered ash phloem exists, but host material introduces potential variability and contamination, and the cost and effort needed to collect and process it can be high. The post-embryonic development of A. planipennis was evaluated on four artificial diets lacking host material, and effects of variations in diet layer thickness and moisture content were also investigated. The best diet and rearing method resulted in 67.8% survival to pupation and 51% to adult. Larval size and development rate were comparable to published accounts for emerald ash borer larvae developing on susceptible host plants. Important advances include reduction of antimicrobial components to the lowest functional level; change of protein sources from wheat germ, brewer’s yeast, and casein to soy flour and casein; reduction of diet moisture content to 50%; and adding a fresh layer of diet to spent diet half-way through larval development. The artificial diet represents a step toward the development of a standardized mass- production system for A. planipennis
The Transesterification of Hickory Nuts into Biodiesel Fuel
• Biodiesel fuels can be produced from a fat and an alcohol via transesterification
• Hickory nuts have a high fat content (~60 % by weight)
• Can nuts from shagbark hickory (Carya ovata) be used to produce a biodiesel fuel using existing acidcatalyzed transesterification methods
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