Mandibular Dentition in Six Species of Salamanders, genus Plethodon (Caudata: Plethontidae), from Arkansas Using Scanning Electron Microscopy

The mandibular (dentary) dentition of six species of Plethodon (P. caddoensis, P. dorsalis, P. fourchensis, P. glutinosus, P. ouachitae, and P. serratus) from Arkansas was studied using scanning electron microscopy. In all species, the mandibular teeth were bicuspid, and each tooth possessed a prominent labial cusp and a well-developed, inward-curving lingual cusp. All species showed similar tooth crown features, except P. caddoensis which exhibited a reduced tooth height and a reduced lingual cusp (only slightly larger than the labial cusp). We compared our data with other studies on premaxillary, maxillary, and palatal teeth in Plethodon and found overall similarities in tooth types. Tooth morphology does not appear to be an effective tool for taxonomic purposes in our Plethodon species because of the range of morphological variation in tooth structure

QCD Constituent Counting Rules for Neutral Vector Mesons

QCD constituent counting rules define the scaling behavior of exclusive hadronic scattering and electromagnetic scattering amplitudes at high momentum transfer in terms of the total number of fundamental constituents in the initial and final states participating in the hard subprocess. The scaling laws reflect the twist of the leading Fock state for each hadron and hence the leading operator that creates the composite state from the vacuum. Thus, the constituent counting scaling laws can be used to identify the twist of exotic hadronic candidates such as tetraquarks and pentaquarks. Effective field theories must consistently implement the scaling rules in order to be consistent with the fundamental theory. Here we examine how one can apply constituent counting rules for the exclusive production of one or two neutral vector mesons $V^0$ in $e^+ e^-$ annihilation, processes in which the $V^0$ can couple via intermediate photons. In case of a (narrow) real $V^0$, the photon virtuality is fixed to a precise value $s_1 = m_{V^0}^2$, in effect treating the $V^0$ as a single fundamental particle. Each real $V^0$ thus contributes to the constituent counting rules with $N_{V_0} = 1$. In effect, the leading operator underlying the $V^0$ has twist 1. Thus, in the specific physical case of single or double on-shell $V^0$ production via intermediate photons, the predicted scaling from counting rules coincides with Vector Meson Dominance (VMD), an effective theory that treats $V^0$ as an elementary field. However, the VMD prediction fails in the general case where the $V^0$ is not coupled through an elementary photon field, and then the leading-twist interpolating operator has twist $N_{V_0} = 2$. Analogous effects appear in $pp$ scattering processes.Comment: 15 page

QCD Compositeness as Revealed in Exclusive Vector Boson Reactions through Double-Photon Annihilation: e+e−→γγ∗→γV0e^+ e^- \to \gamma \gamma^\ast \to \gamma V^0 and e+e−→γ∗γ∗→V0V0e^+ e^- \to \gamma^\ast \gamma^\ast \to V^0 V^0

We study the exclusive double-photon annihilation processes, $e^+ e^- \to \gamma \gamma^\ast\to \gamma V^0$ and $e^+ e^- \to \gamma^\ast \gamma^\ast \to V^0_a V^0_b,$ where the $V^0_i$ is a neutral vector meson produced in the forward kinematical region: $s \gg -t$ and $-t \gg \Lambda_{\rm QCD}^2$. We show how the differential cross sections $\frac{d\sigma}{dt}$, as predicted by QCD, have additional falloff in the momentum transfer squared $t$ due to the QCD compositeness of the hadrons, consistent with the leading-twist fixed-$\theta_{\rm CM}$ scaling laws. However, even though they are exclusive channels and not associated with the conventional electron-positron annihilation process $e^+ e^- \to \gamma^\ast \to q \bar q,$ these total cross sections $\sigma(e^+ e^- \to \gamma V^0)$ and $\sigma(e^+ e^- \to V^0_a V^0_b),$ integrated over the dominant forward- and backward-$\theta_{\rm CM}$ angular domains, scale as $1/s$, and thus contribute to the leading-twist scaling behavior of the ratio $R_{e^+ e^-}$. We generalize these results to exclusive double-electroweak vector-boson annihilation processes accompanied by the forward production of hadrons, such as $e^+ e^- \to Z^0 V^0$ and $e^+ e^- \to W^-\rho^+$. These results can also be applied to the exclusive production of exotic hadrons such as tetraquarks, where the cross-section scaling behavior can reveal their multiquark nature.Comment: 10 page

Book Reviews

Books reviewed: Manly Hardy (1832-1910): The Life and Writing of a Maine Fur-Buyer, Hunter, and Naturalist. Compiled and Introduced by William B. Krohn; The Grand Old Man of Maine: Selected Letters of Joshua Lawrence Chamberlain, 1865-1914, edited by Jeremiah E. Goulka; Israel Washburn Jr.: Maine’s Little-Known Giant of the Civil War, by Kerck Kelsey; Longfellow: A Rediscovered Life, by Charles C. Calhou

Book Reviews

Books reviewed: Manly Hardy (1832-1910): The Life and Writing of a Maine Fur-Buyer, Hunter, and Naturalist. Compiled and Introduced by William B. Krohn; The Grand Old Man of Maine: Selected Letters of Joshua Lawrence Chamberlain, 1865-1914, edited by Jeremiah E. Goulka; Israel Washburn Jr.: Maine’s Little-Known Giant of the Civil War, by Kerck Kelsey; Longfellow: A Rediscovered Life, by Charles C. Calhou

Application of a High-Fidelity Icing Analysis Method to a Model-Scale Rotor in Forward Flight

An icing analysis process involving the loose coupling of OVERFLOW-RCAS for rotor performance prediction and with LEWICE3D for thermal analysis and ice accretion is applied to a model-scale rotor for validation. The process offers high-fidelity rotor analysis for the noniced and iced rotor performance evaluation that accounts for the interaction of nonlinear aerodynamics with blade elastic deformations. Ice accumulation prediction also involves loosely coupled data exchanges between OVERFLOW and LEWICE3D to produce accurate ice shapes. Validation of the process uses data collected in the 1993 icing test involving Sikorsky's Powered Force Model. Non-iced and iced rotor performance predictions are compared to experimental measurements as are predicted ice shapes

Spanish Artifacts from Santa Elena

This volume contains Parts I and 2 of a three-part presentation of the artifacts relating to the sixteenth century Spanish occupation of the colonial capital of La Florida at Santa Elena, located on Parris Island, South Carolina from 1566 to 1587. Part 1, by Stanley South, with contributions by Eugene Lyon, Richard Polhemus, William Radisch and Carl Steen, comprises the Spanish non-ceramic artifacts. Part 2, by Russell Skowronek, Richard Johnson and Stanley South, examines the Spanish imported ceramics. Part 3, incomplete at this writing, by Chester Depratter, deals with the Spanish-contemporary Indian pottery. This third part will be published as a separate volume at a later date. The entire artifact inventory of the artifacts from Santa Elena is presented in this three-part volume, being those recovered from a number of expeditions to the site between 1979 and 1985. For comparative use the appendices contain the tabulated artifact inventory resulting from these expeditions. Synthesizing tables from these data are presented in the text. This information should prove useful to students of sixteenth century Spanish colonial history, particularly historical archaeologists involved in excavating sites of this period wherever they may be.https://scholarcommons.sc.edu/archanth_anthro_studies/1008/thumbnail.jp

Information dissemination in the water resources field

A study of mercury accumulation in trout taken from the trout parks and streams of southern Missouri is presented. Mercury in trout is determined by digestion in nitric acid, sulfurid acid, and potassium permanganate, followed by reduction and aeration for measurement by flameless atomic absorpotion. The mercury accumulation in trout collected and analyzed in this project ranged from 0.1 to 0.3 ppm mercury (ug mercury/g of tissue). The mercury levels were relatively constant and showed no variation or higher level accumulation with increased size. The results of the analysis on the liver and flesh of the same trout showed that the levels in the liver were slightly higher than the levels in the flesh. Previous analysis of trout collected in the mid to late 1950's from the Little Piney River indicated mercury accumulations of approximately 3 ppm. Over the past 25 years, there has been a substantial decrease in mercury found in trout of southern Missouri as a result of cleaner streams.Project # X-145-MO Agreement # 14-31-0001-426

Automated potentiometric techniques for the on-site monitoring of anion concentrations in water

Students supported: 2 Grad Students, 2 Undergraduate StudentsCharacteristics of several of the new non-glass ion-selective electrodes and of several reference electrodes were studied in detail. The most significant finding of the research was the development of a new high accuracy standard addition technique for the potentiometric determination of nitrate ion in a cell without liquid junction using the fluoride ion-selective electrode as a reference. This method eliminates the liquid junction and dilution and activity coefficient changes cancel. The standard addition technique with the fluoride electrode as a reference is applicable to all monovalent anions for which an electrode is available and enables the determination of anion concentrations to within 1 percent relative accuracy. Low temperature potentiometric titrations of perchlorate and tetrafluoroborate ions were investigated and found to give very high accuracy and reasonably good sensitivity for these ions. Tetraphenylarsonium chloride was used as a titrant for perchlorate and tetrafluoroborate. The application of the nitrate ion-selective electrode to following nitrate ion concentration in microbial cultures was investigated. It was found to be useful for following nitrate ion reduction in situ.Project # B-023-MO Agreement # 14-01-0001-191