Spanning Trees in Graphs of High Minimum Degree with a Universal Vertex I: An Approximate Asymptotic Result

In this paper and a companion paper, we prove that, if $m$ is sufficiently large, every graph on $m+1$ vertices that has a universal vertex and minimum degree at least $\lfloor \frac{2m}{3} \rfloor$ contains each tree $T$ with $m$ edges as a subgraph. The present paper already contains an approximate asymptotic version of the result. Our result confirms, for large $m$, an important special case of a recent conjecture by Havet, Reed, Stein, and Wood.Comment: 46 page

Spanning Trees in Graphs of High Minimum Degree which have a Universal Vertex II: A Tight Result

We prove that, if $m$ is sufficiently large, every graph on $m+1$ vertices that has a universal vertex and minimum degree at least $\lfloor \frac{2m}{3} \rfloor$ contains each tree $T$ with $m$ edges as a subgraph. Our result confirms, for large $m$, an important special case of a conjecture by Havet, Reed, Stein, and Wood. The present paper builds on the results of a companion paper in which we proved the statement for all trees having a vertex that is adjacent to many leaves.Comment: 29 page

A Variant of the Erd\H{o}s-S\'os Conjecture

A well-known conjecture of Erd\H{o}s and S\'os states that every graph with average degree exceeding $m-1$ contains every tree with $m$ edges as a subgraph. We propose a variant of this conjecture, which states that every graph of maximum degree exceeding $m$ and minimum degree at least $\lfloor \frac{2m}{3}\rfloor$ contains every tree with $m$ edges. As evidence for our conjecture we show (i) for every $m$ there is a $g(m)$ such that the weakening of the conjecture obtained by replacing $m$ by $g(m)$ holds, and (ii) there is a $\gamma>0$ such that the weakening of the conjecture obtained by replacing $\lfloor \frac{2m}{3}\rfloor$ by $(1-\gamma)m$ holds

Endangered by Sprawl: How Runaway Development Threatens America's Wildlife

Estimates the growth of land consumption in metropolitan areas over the next 25 years, investigates locally implemented strategies to protect natural lands from overdevelopment, and offers "smart growth" as an option for reducing suburban sprawl

Use of Role-play and Gamification in a Software Project Course

Soft skills are increasingly important to the engineering profession and course modifications are often needed to ensure students have opportunities to practice them prior to graduation. This suggests that engineering programs need to go beyond simply offering industry-based capstone courses and internships. Role-play has a long history as a tool for learning. It can be used to simulate real world practices in environments where consequences can be mitigated safely. In this paper, we discuss the use of team role-play activities to simulate the experience of working in a professional, game development studio as a means of enhancing an advanced undergraduate game design course. In conjunction with the role-play, a gamification framework was used within the course to allow students to customize their course participation. Gamification was used to reward students for compliance with software process steps and for taking the initiative to improve their “soft skills”. In this project, allowing students to negotiate the nature of their activities and rewards helped them develop those skills. We are using student feedback and our own lessons learned to plan the next iteration of this course

SAR by MS for Functional Genomics (Structure-Activity Relation by Mass Spectrometry)

Large-scale functional genomics will require fast, high-throughput experimental techniques, coupled with sophisticated computer algorithms for data analysis and experiment planning. In this paper, we introduce a combined experimental-computational protocol called Structure-Activity Relation by Mass Spectrometry (SAR by MS), which can be used to elucidate the function of protein-DNA or protein-protein complexes. We present algorithms for SAR by MS and analyze their complexity. Carefully-designed Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight (MALDI TOF) and Electrospray Ionization (ESI) assays require only femtomolar samples, take only microseconds per spectrum to record, enjoy a resolution of up to one dalton in $10^6$, and (in the case of MALDI) can operate on protein complexes up to a megadalton in mass. Hence, the technique is attractive for high-throughput functional genomics. In SAR by MS, selected residues or nucleosides are 2H-, 13C-, and/or 15N-labeled. Second, the complex is crosslinked. Third, the complex is cleaved with proteases and/or endonucleases. Depending on the binding mode, some cleavage sites will be shielded by the crosslinking. Finally, a mass spectrum of the resulting fragments is obtained and analyzed. The last step is the Data Analysis phase, in which the mass signatures are interpreted to obtain constraints on the functional binding mode. Experiment Planning entails deciding what labeling strategy and cleaving agents to employ, so as to minimize mass degeneracy and spectral overlap, in order that the constraints derived in data analysis yield a small number of binding hypotheses. A number of combinatorial and algorithmic questions arise in deriving algorithms for both Experiment Planning and Data Analysis. We explore the complexity of these problems, obtaining upper and lower bounds. Experimental results are reported from an implementation of our algorithms

Local scales on curves and surfaces

In this paper, we extend our previous work on the study of local scales of a function to studying local scales on curves and surfaces. In the case of a function f, the local scales of f at x is computed by measuring the deviation of f from a linear function near x at different scales t's. In the case of a d-dimensional surface E, the analogy is to measure the deviation of E from a d-plane near x on E at various scale t's. We then apply the theory of singular integral operators on E to show useful properties of local scales. We will also show that the defined local scales are consistent in the sense that the number of local scales are invariant under dilation

976-14 Immediate Heart Rate Response to Orthostatic Stress During β-blocker Therapy for Vasodepressor Syncope

Although β-blockers are preferred agents for therapy of vasodepressor syncope (VDS), they are not uniformly effective and their mechanism of action is incompletely understood. Since we have previously shown a differential therapeutic response to β-blocker therapy between pts with isoproterenol-independent [iso(-)] and isoproterenol-dependent [iso(+)] VDS during tilt table testing we sought to determine whether this was due to a differential heart rate (HR) response to orthostasis during β-blockade. We therefore examined immediate HR and blood pressure responses to upright tilt before and after initiation of therapy with atenolol (12.5–50mg daily) in 62 pts with VDS and positive tilt tests. The protocol comprised upright tilt (60°) for up to 60min followed by repeat tilt for 15min during isoproterenol (iso) infusion. Supine HR, mean arterial pressure (MAP) and pulse pressure (PP) were determined as the mean of 3 consecutive 1-min samples during supine rest; orthostatic HR, MAP, and PP were the mean of the samples recorded in the first 3min after upright tilt (before infusion of iso). Response to atenolol required completion of tilt with and without infusion of iso. There were 15 iso(-) pts and 47 iso(+) pts. The groups did not differ significantly in blood pressure response (MAP, PP) to orthostasis. Supine HR fell and the ΔHR in response to orthostasis was blunted during therapy in both groups:Baseline (Mean ± SD)Rx (Mean ± SD)Iso(+)Iso(-)pIso(+)Iso(-)pSupine HR69±1368±9NS57±958±8NSOrthostatic ΔHR8±712±9NS3±53±4NS11 iso(-) pts (73%) had a therapeutic response to β-blockade compared with 46 iso(+) pts (98%, p=0.01); the orthostatic ΔHR in the iso(-) pts who failed β-blocker therapy was no different from the response in the patients with a therapeutic response.ConclusionsThe HR response to orthostasis is comparably blunted after β-blockade in pts with iso(-) and iso(+) VDS, indicating that failure to respond is not due to inadequate β-blockade and suggests that in some pts iso-independent VDS may be independent of a cardiac β1 receptor mediated mechanism

When are Non-Double-Couple Components of Seismic Moment Tensors Reliable?

There has been considerable discussion as to how to assess when non-double-couple (NDC) components of seismic moment tensors represent real source processes. We explore this question by comparing moment tensors (MTs) of earthquakes in three global catalogs, which use different inversion procedures. Their NDC components are only weakly correlated between catalogs, suggesting that they are largely artifacts of the inversion. A monotonic decrease in the NDC components' standard deviation with magnitude indicates increased reliability of the NDC components for larger earthquakes. The standard deviation begins to decrease for large NDC components exceeding 60%, suggesting that they represent real source processes. Randomly generated NDC components with the same mean and standard deviation as in the MT catalogs only reproduce some of this decrease. Thus NDC components of large earthquakes and NDC components that exceed 60% are likely to represent real source processes

Duty of Notification and Aviation SafetyA Study of Fatal Aviation Accidents in the United States in 2015

After the Germanwings accident, the French Safety Investigation Authority (BEA) recommended that the World Health Organization (WHO) and European Community (EC) develop clear rules for the duty of notification process. Aeromedical practitioners (AMEs) face a dilemma when considering the duty of notification and conflicts between pilot privacy and public and third-party safety. When balancing accountability, knowledge of the duty of notification process, legislation and the clarification of a doctor's own set of values should be assessed a priori. Relatively little is known of the magnitude of this problem in aviation safety. To address this, the National Transportation Safety Board (NTSB) database was searched to identify fatal accidents during 2015 in the United States in which a deceased pilot used a prescribed medication or had a disease that potentially reduced pilot performance and was not reported to the AME. Altogether, 202 finalized accident reports with toxicology were available from (the year) 2015. In 5% (10/202) of these reports, the pilot had either a medication or a disease not reported to an AME which according to the accident investigation was causal to the fatal accident. In addition, the various approaches to duty of notification in aviation in New Zealand, Finland and Norway are discussed. The process of notification of authorities without a pilot's express permission needs to be carried out by using a guidance protocol that works within legislation and professional responsibilities to address the pilot and the public, as well as the healthcare provider. Professional guidance defining this duty of notification is urgently needed.Peer reviewe