Nomenclatural Changes for Some Diatoms Found in Iowa

Nomenclatural revisions for four diatom taxa found in Iowa, two of which are presently maintained in the Loras College Freshwater Diatom Culture Collection (FDCC), are necessary because of systematic interpretations of the Division Bacillariophyta. Achnanthidium hauckianum (Grun.) Czarnecki comb. nov. was originally assigned to the genus Achnanthes Bory. Three taxa were previously assigned to the morphologically diverse genus Navicula Bory. These are Cavinula weinzierlii (Schimanski) Czarnecki comb. nov., Craticula cuspidata var. major [(Meist.) Czarnecki comb. nov. and] Craticula halophila var. subcapitata (0str.) Czarnecki comb. nov

The Itasca State Park Algal Culture Collection at Loras College

A list of over 125 algal cultures originating from Lake Itasca State Park is presented. These cultures, permanently housed at Loras College, Dubuque, Ia., include 115 taxa representing 68 genera from six algal Divisions. Approximately one-third of the taxa are desmids

Open-ended Learning in Symmetric Zero-sum Games

Zero-sum games such as chess and poker are, abstractly, functions that evaluate pairs of agents, for example labeling them `winner' and `loser'. If the game is approximately transitive, then self-play generates sequences of agents of increasing strength. However, nontransitive games, such as rock-paper-scissors, can exhibit strategic cycles, and there is no longer a clear objective -- we want agents to increase in strength, but against whom is unclear. In this paper, we introduce a geometric framework for formulating agent objectives in zero-sum games, in order to construct adaptive sequences of objectives that yield open-ended learning. The framework allows us to reason about population performance in nontransitive games, and enables the development of a new algorithm (rectified Nash response, PSRO_rN) that uses game-theoretic niching to construct diverse populations of effective agents, producing a stronger set of agents than existing algorithms. We apply PSRO_rN to two highly nontransitive resource allocation games and find that PSRO_rN consistently outperforms the existing alternatives.Comment: ICML 2019, final versio

Additions and Confirmations to the Algal Flora of Itasca State Park I. Desmids and Diatoms from North Deming Pond

The summer desmid and diatom flora of North Deming Pond in lake Itasca State Park is presented. One hundred sixty desmid taxa representing 23 genera are recorded. Of these, 15 taxa appear to be park records and 82 are apparently Minnesota records. The desmid genera, Closterium, Cosmarium, Euastrum, Micrasterias, Pleurotaenium, and Staurastrum display the most taxa. The 136 diatom taxa recorded represent 27 genera. More than half of the taxa are assignable to the genera Eunotia, Navicula, Neidium, and Pinnularia. Given the brief and cursory nature of this study, the taxomic representation of these algae indicates high species richness and diversity in the Itasca Park area and suggests the need for further taxonomic inventory

Key Distributions for Charmless Semileptonic B Decay

We present theoretical predictions for a few phenomenologically interesting distributions in the semileptonic b->u decays which are affected by Fermi motion. The perturbative effects are incorporated at the one-loop level and appear to be very moderate. Our treatment of Fermi motion is based directly on QCD, being encoded in the universal distribution function F(x). The decay distributions in the charged lepton energy, invariant mass of hadrons, hadron energy, and q^2 are given. We note that typically about 90% of all decay events are expected to have M_X < M_D; this feature can be exploited in determination of |V_ub|.Comment: 9 pages, 6 figures (incorporated in the LaTeX file); plain LaTe

An approach to implementing dynamic adaptation in c

This paper describes TRAP/C++, a software tool that enables new adaptable behavior to be added to existing C++ programs in a transparent fashion. In previous investigations, we used an aspectoriented approach to manually define aspects for adaptation infrastructure, which were woven into the original application code at compile time. In follow-on work, we developed TRAP, a transparent shaping technique for automatically generating adaptation aspects, where TRAP/J is a specific instantiation of TRAP. This paper presents our work into building TRAP/C++, which was intended to be a port of TRAP/J into C++. Designing TRAP/C++ required us to overcome two major hurdles: lack of reflection in C++ and the incompatibility between the management of objects in C++ and the aspect weaving technique used in TRAP/J. We used generative programming methods to produce two tools, TrapGen and TrapCC, that work together to produce the desired TRAP/C++ functionality. Details of the TRAP/C++ architecture and operation are presented, which we illustrate with a description of a case study that adds dynamic auditing capabilities to an existing distributed C++ application

Asymptotics of Feynman Diagrams and The Mellin-Barnes Representation

It is shown that the integral representation of Feynman diagrams in terms of the traditional Feynman parameters, when combined with properties of the Mellin--Barnes representation and the so called {\it converse mapping theorem}, provide a very simple and efficient way to obtain the analytic asymptotic behaviours in both the large and small ratios of mass scales.Comment: References added. This is the version published in Physics Letters