Assessing statistical significance of periodogram peaks

The least-squares (or Lomb-Scargle) periodogram is a powerful tool which is used routinely in many branches of astronomy to search for periodicities in observational data. The problem of assessing statistical significance of candidate periodicities for different periodograms is considered. Based on results in extreme value theory, improved analytic estimations of false alarm probabilities are given. They include an upper limit to the false alarm probability (or a lower limit to the significance). These estimations are tested numerically in order to establish regions of their practical applicability.Comment: 7 pages, 6 figures, 1 table; To be published in MNRA

Take Care- Use Antibiotics Responsibly Swine Practitioner Project

The Take Care - Use Antibrotics Responsibly® program is an antimicrobial resistance and use educat1on and awareness program for pork producers. The program is based on principles and guidelines intended to minimize the development of antimicrobial resistance whrle maximizing animal health The program was developed by the National Pork Board, but veterinarians are key in the delivery of the program on farm. Since there are many factors that contribute to the amounts and types of antimicrobrals used on farm it was decided that the best way to measure program effectiveness was through measurement of changes in the attitude and behaviors of program particrpants

The Impact of Active Learning in a Speech-Language Pathology Swallowing and Dysphagia Course

The signature pedagogy in Speech-Language Pathology (SLP) higher education programs has been criticized for its instructor-centric lecture format and emphasis on the lower tiers of Bloom’s taxonomy (simply memorizing knowledge) at the expense of helping students develop the clinical problem-solving skills required for a lifetime of practice and learning. The purpose of this study was to examine the responses of a cohort of graduate speech-language pathology students to an active learning-oriented swallowing and dysphagia course design. A potential relationship between student perceptions of the active learning pedagogy and academic performance was also explored. The results suggest that active learning positively impacted both student perceptions and performance in the redesigned swallowing and dysphagia course

The response of Kentucky bluegrass turf to insecticidal treatments

The most common insect pests of Kentucky bluegrass (Poa pratensis L.) in Tennessee are sod webworms and white grubs. Attempts to control these insects with insecticides has, at times, resulted in the entire destruction of the lawn by sod webworms. Pass (1965) has shown that applications of aldrin, chlordane, and dieldrin increased the webworm population 2-3 fold. Streu and Vasvary (1966) found the same phenomenon in chinch bug control. Both Pass and Streu believed that this population increase of the target pest may have been related to an interference in some population-limiting mechanism, such as the natural enemies, but neither investigator definitely proved this. In view of the problem that home owners have had after applying insecticides for webworm and grub control, it was decided to conduct a study to determine the overall effects of insecticides on bluegrass. The research reported herein covers only a preliminary phase of that study: the effect of insecticides on botanical composition of a bluegrass turf

Population coding by globally coupled phase oscillators

A system of globally coupled phase oscillators subject to an external input is considered as a simple model of neural circuits coding external stimulus. The information coding efficiency of the system in its asynchronous state is quantified using Fisher information. The effect of coupling and noise on the information coding efficiency in the stationary state is analyzed. The relaxation process of the system after the presentation of an external input is also studied. It is found that the information coding efficiency exhibits a large transient increase before the system relaxes to the final stationary state.Comment: 7 pages, 9 figures, revised version, new figures added, to appear in JPSJ Vol 75, No.

Endoscopic papillectomy: risk factors for incomplete resection and recurrence during long-term follow-up

Background Endoscopic papillectomy is increasingly used as an alternative to surgery for ampullary adenomas and other noninvasive ampullary lesions. Objective To measure short-term safety and efficacy of endoscopic papillectomy, define patient and lesion characteristics associated with incomplete endoscopic resection, and measure adenoma recurrence rates during long-term follow-up. Design Retrospective cohort study. Setting Tertiary-care academic medical center. Patients All patients who underwent endoscopic papillectomy for ampullary lesions between July 1995 and June 2012. Intervention Endoscopic papillectomy. Main Outcome Measurements Patient and lesion characteristics associated with incomplete endoscopic resection and ampullary adenoma-free survival analysis. Results We identified 182 patients who underwent endoscopic papillectomy, 134 (73.6%) having complete resection. Short-term adverse events occurred in 34 (18.7%). Risk factors for incomplete resection were jaundice at presentation (odds ratio [OR] 0.21, 95% confidence interval [CI] 0.07–0.69; P = .009), occult adenocarcinoma (OR 0.06, 95% CI, 0.01–0.36; P = .002), and intraductal involvement (OR 0.29, 95% CI, 0.11–0.75; P = .011). The en bloc resection technique was strongly associated with a higher rate of complete resection (OR 4.05, 95% CI, 1.71–9.59; P = .001). Among patients with ampullary adenoma who had complete resection (n = 107), 16 patients (15%) developed recurrence up to 65 months after resection. Limitations Retrospective analysis. Conclusion Jaundice at presentation, occult adenocarcinoma in the resected specimen, and intraductal involvement are associated with a lower rate of complete resection, whereas en bloc papillectomy increases the odds of complete endoscopic resection. Despite complete resection, recurrence was observed up to 5 years after papillectomy, confirming the need for long-term surveillance

Wear Minimization for Cuckoo Hashing: How Not to Throw a Lot of Eggs into One Basket

We study wear-leveling techniques for cuckoo hashing, showing that it is possible to achieve a memory wear bound of $\log\log n+O(1)$ after the insertion of $n$ items into a table of size $Cn$ for a suitable constant $C$ using cuckoo hashing. Moreover, we study our cuckoo hashing method empirically, showing that it significantly improves on the memory wear performance for classic cuckoo hashing and linear probing in practice.Comment: 13 pages, 1 table, 7 figures; to appear at the 13th Symposium on Experimental Algorithms (SEA 2014

On Hilberg's Law and Its Links with Guiraud's Law

Hilberg (1990) supposed that finite-order excess entropy of a random human text is proportional to the square root of the text length. Assuming that Hilberg's hypothesis is true, we derive Guiraud's law, which states that the number of word types in a text is greater than proportional to the square root of the text length. Our derivation is based on some mathematical conjecture in coding theory and on several experiments suggesting that words can be defined approximately as the nonterminals of the shortest context-free grammar for the text. Such operational definition of words can be applied even to texts deprived of spaces, which do not allow for Mandelbrot's ``intermittent silence'' explanation of Zipf's and Guiraud's laws. In contrast to Mandelbrot's, our model assumes some probabilistic long-memory effects in human narration and might be capable of explaining Menzerath's law.Comment: To appear in Journal of Quantitative Linguistic

Full potential LAPW calculation of electron momentum density and related properties of Li

Electron momentum density and Compton profiles in Lithium along $$,$$, and $$ directions are calculated using Full-Potential Linear Augmented Plane Wave basis within generalized gradient approximation. The profiles have been corrected for correlations with Lam-Platzman formulation using self-consistent charge density. The first and second derivatives of Compton profiles are studied to investigate the Fermi surface breaks. Decent agreement is observed between recent experimental and our calculated values. Our values for the derivatives are found to be in better agreement with experiments than earlier theoretical results. Two-photon momentum density and one- and two-dimensional angular correlation of positron annihilation radiation are also calculated within the same formalism and including the electron-positron enhancement factor.Comment: 11 pages, 7 figures TO appear in Physical Review

Model Calculations for the Two-Fragment Electro-Disintegration of 4^4He

Differential cross sections for the electro-disintegration process $e + {^4He} \longrightarrow {^3H}+ p + e'$ are calculated, using a model in which the final state interaction is included by means of a nucleon-nucleus (3+1) potential constructed via Marchenko inversion. The required bound-state wave functions are calculated within the integrodifferential equation approach (IDEA). In our model the important condition that the initial bound state and the final scattering state are orthogonal is fulfilled. The sensitivity of the cross section to the input $p{^3H}$ interaction in certain kinematical regions is investigated. The approach adopted could be useful in reactions involving few cluster systems where effective interactions are not well known and exact methods are presently unavailable. Although, our Plane-Wave Impulse Approximation results exhibit, similarly to other calculations, a dip in the five-fold differential cross-section around a missing momentum of $\sim 450 MeV/c$, it is argued that this is an artifact of the omission of re-scattering four-nucleon processes.Comment: 16 pages, 6 figures, accepted for publication by Phys.Rev.