Applying Rule Ensembles to the Search for Super-Symmetry at the Large Hadron Collider

In this note we give an example application of a recently presented predictive learning method called Rule Ensembles. The application we present is the search for super-symmetric particles at the Large Hadron Collider. In particular, we consider the problem of separating the background coming from top quark production from the signal of super-symmetric particles. The method is based on an expansion of base learners, each learner being a rule, i.e. a combination of cuts in the variable space describing signal and background. These rules are generated from an ensemble of decision trees. One of the results of the method is a set of rules (cuts) ordered according to their importance, which gives useful tools for diagnosis of the model. We also compare the method to a number of other multivariate methods, in particular Artificial Neural Networks, the likelihood method and the recently presented boosted decision tree method. We find better performance of Rule Ensembles in all cases. For example for a given significance the amount of data needed to claim SUSY discovery could be reduced by 15 % using Rule Ensembles as compared to using a likelihood method.Comment: 24 pages, 7 figures, replaced to match version accepted for publication in JHE

Boston Hospitality Review: Winter 2017

Table of contents: Family, Team or Something Else? by John Murtha -- Kitchen Organization in Full-Service Restaurants: Reducing Heat and Stress by Peter Szende and Justin Cipriano -- Rules of Engagement: Building Brand Relationships by Alex Friedman -- Corporate Social Responsibility in the Hospitality Sector by Manisha Singal and Yinyoung Rhou -- “Hold on, I have to post this on Instagram”: Trends, Talk, and Transactions of the Experiential Consumer by Steve Kent -- C-corporation Hotels vs. Hotel-REITs: A Theoretical and Practical Comparison by Tarik Dogru -- Sisters in Restaurant Success: A History of The Maramor by Jan WhitakerFamily, Team or Something Else? by John Murtha -- Kitchen Organization in Full-Service Restaurants: Reducing Heat and Stress by Peter Szende and Justin Cipriano -- Rules of Engagement: Building Brand Relationships by Alex Friedman -- Corporate Social Responsibility in the Hospitality Sector by Manisha Singal and Yinyoung Rhou -- “Hold on, I have to post this on Instagram”: Trends, Talk, and Transactions of the Experiential Consumer by Steve Kent -- C-corporation Hotels vs. Hotel-REITs: A Theoretical and Practical Comparison by Tarik Dogru -- Sisters in Restaurant Success: A History of The Maramor by Jan Whitake

Liquid-Gas Coexistence and Critical Behavior in Boxed Pseudo-Fermi Matter

A schematic model is presented that allows one to study the behavior of interacting pseudo-Fermi matter locked in a thermostatic box. As a function of the box volume and temperature, the matter is seen to show all of the familiar charactersitics of a Van der Waals gas, which include the coexistence of two phases under certain circumstances and the presence of a critical point

Formation, regulation and evolution of Caenorhabditis elegans 3'UTRs

Post-transcriptional gene regulation frequently occurs through elements in mRNA 3′ untranslated regions (UTRs)1, 2. Although crucial roles for 3′UTR-mediated gene regulation have been found in Caenorhabditis elegans3, 4, 5, most C. elegans genes have lacked annotated 3′UTRs6, 7. Here we describe a high-throughput method for reliable identification of polyadenylated RNA termini, and we apply this method, called poly(A)-position profiling by sequencing (3P-Seq), to determine C. elegans 3′UTRs. Compared to standard methods also recently applied to C. elegans UTRs8, 3P-Seq identified 8,580 additional UTRs while excluding thousands of shorter UTR isoforms that do not seem to be authentic. Analysis of this expanded and corrected data set suggested that the high A/U content of C. elegans 3′UTRs facilitated genome compaction, because the elements specifying cleavage and polyadenylation, which are A/U rich, can more readily emerge in A/U-rich regions. Indeed, 30% of the protein-coding genes have mRNAs with alternative, partially overlapping end regions that generate another 10,480 cleavage and polyadenylation sites that had gone largely unnoticed and represent potential evolutionary intermediates of progressive UTR shortening. Moreover, a third of the convergently transcribed genes use palindromic arrangements of bidirectional elements to specify UTRs with convergent overlap, which also contributes to genome compaction by eliminating regions between genes. Although nematode 3′UTRs have median length only one-sixth that of mammalian 3′UTRs, they have twice the density of conserved microRNA sites, in part because additional types of seed-complementary sites are preferentially conserved. These findings reveal the influence of cleavage and polyadenylation on the evolution of genome architecture and provide resources for studying post-transcriptional gene regulation.National Institutes of Health (U.S.) (Grant number GM067031)National Science Foundation (U.S.). Predoctural FellowshipUnited States. Dept. of Energy. Computational Science Graduate Fellowship (Krell Institute

A stochastic perturbation of inviscid flows

We prove existence and regularity of the stochastic flows used in the stochastic Lagrangian formulation of the incompressible Navier-Stokes equations (with periodic boundary conditions), and consequently obtain a \holderspace{k}{\alpha} local existence result for the Navier-Stokes equations. Our estimates are independent of viscosity, allowing us to consider the inviscid limit. We show that as $\nu \to 0$, solutions of the stochastic Lagrangian formulation (with periodic boundary conditions) converge to solutions of the Euler equations at the rate of $O(\sqrt{\nu t})$.Comment: 13 pages, no figures

Can central-venous oxygen saturation be estimated from tissue oxygen saturation during a venous occlusion test?

OBJECTIVE: To test whether tissue oxygen saturation (StO(2)) after a venous occlusion test estimates central venous oxygen saturation (ScvO(2)). METHODS: Observational study in intensive care unit patients. Tissue oxygen saturation was monitored (InSpectra Tissue Spectrometer Model 650, Hutchinson Technology Inc., MN, USA) with a multiprobe (15/25mm) in the thenar position. A venous occlusion test in volunteers was applied in the upper arm to test the tolerability and pattern of StO(2) changes during the venous occlusion test. A sphygmomanometer cuff was inflated to a pressure 30mmHg above diastolic pressure until StO(2) reached a plateau and deflated to 0mmHg. Tissue oxygen saturation parameters were divided into resting StO(2) (r-StO(2)) and minimal StO(2) (m-StO(2)) at the end of the venous occlusion test. In patients, the cuff was inflated to a pressure 30mmHg above diastolic pressure for 5 min (volunteers’ time derived) or until a StO(2) plateau was reached. Tissue oxygen saturation parameters were divided into r-StO(2), m-StO(2), and the mean time that StO(2) reached ScvO(2). The StO(2) value at the mean time was compared to ScvO(2). RESULTS: All 9 volunteers tolerated the venous occlusion test. The time for tolerability or the StO(2) plateau was 7 ± 1 minutes. We studied 22 patients. The mean time for StO(2) equalized ScvO(2) was 100 sec and 95 sec (15/25mm probes). The StO(2) value at 100 sec ([100-StO(2)] 15mm: 74 ± 7%; 25mm: 74 ± 6%) was then compared with ScvO(2) (75 ± 6%). The StO(2) value at 100 sec correlated with ScvO(2) (15 mm: R(2) = 0.63, 25mm: R(2) = 0.67, p < 0.01) without discrepancy (Bland Altman). CONCLUSION: Central venous oxygen saturation can be estimated from StO(2) during a venous occlusion test

Chemical and transcriptomic diversity do not correlate with ascending levels of social complexity in the insect order Blattodea

Eusocial insects, such as ants and termites, are characterized by high levels of coordinated social organization. This is contrasted by solitary insects that display more limited forms of collective behavior. It has been hypothesized that this gradient in sociobehavioral sophistication is positively correlated with chemical profile complexity, due to a potentially increased demand for diversity in chemical communication mechanisms in insects with higher levels of social complexity. However, this claim has rarely been assessed empirically. Here, we compare different levels of chemical and transcriptomic complexity in selected species of the order Blattodea that represent different levels of social organization, from solitary to eusocial. We primarily focus on cuticular hydrocarbon (CHC) complexity, since it has repeatedly been demonstrated that CHCs are key signaling molecules conveying a wide variety of chemical information in solitary as well as eusocial insects. We assessed CHC complexity and divergence between our studied taxa of different social complexity levels as well as the differentiation of their respective repertoires of CHC biosynthesis gene transcripts. Surprisingly, we did not find any consistent pattern of chemical complexity correlating with social complexity, nor did the overall chemical divergence or transcriptomic repertoire of CHC biosynthesis genes reflect on the levels of social organization. Our results challenge the assumption that increasing social complexity is generally reflected in more complex chemical profiles and point toward the need for a more cautious and differentiated view on correlating complexity on a chemical, genetic, and social level

A stochastic Lagrangian representation of the 3-dimensional incompressible Navier-Stokes equations

In this paper we derive a representation of the deterministic 3-dimensional Navier-Stokes equations based on stochastic Lagrangian paths. The particle trajectories obey SDEs driven by a uniform Wiener process; the inviscid Weber formula for the Euler equations of ideal fluids is used to recover the velocity field. This method admits a self-contained proof of local existence for the nonlinear stochastic system, and can be extended to formulate stochastic representations of related hydrodynamic-type equations, including viscous Burgers equations and LANS-alpha models.Comment: v4: Minor corrections to bibliography, and final version that will apear in CPAM. v3: Minor corrections to the algebra in the last section. v2: Minor changes to introduction and refferences. 14 pages, 0 figure

Sharing Fear via Facebook: A Lesson in Political Public Relations

Our study compared the use of fear messages on Facebook by Barack Obama and Mitt Romney during the 2012 U.S. presidential elections. Results show that written fear messages embedded in photographs posted on Facebook by both candidates affected the degree to which those photographs were shared. More specifically, photographs containing written fear messages were shared more often than photographs not containing written fear messages. Furthermore, while the challenging candidate, Mitt Romney, used more photographs containing fear messages, the increase in shares was consistent across candidates. Implications regarding information distribution within communities, public relations practitioners specializing in political campaigning and society as a whole are discusse