bluuebunny/crossref_metadata_2025_split huggingface dataset:
Infrared dynamics in (2+1) dimensions
Authors: Boldo J L , Pimentel B M , Tomazelli J L 
Published: April 2011

In this work we study the asymptotic behavior of (2+1)-dimensional quantum electrodynamics in the infrared region. We show that an appropriate redefinition of the fermion current operator leads to an asymptotic evolution operator that contains a divergent Coulomb phase factor and a contribution from the electromagnetic field at large distances, factored from the evolution operator for free fields, and we conclude that the modified scattering operator maps two spaces of coherent states of the electromagnetic field, as in the KulishFaddeev model for QED (quantum electrodynamics) in four space-time dimensions. PACS No. 11.10Kk, 11.55m
Spectral approximation by the polar transformation
Authors: Hall R L , Zhou W H 
Published: April 2011

Central potentials V(r) are considered that admit the polar representation V(r) = g(h(r)), where h(r) = sgn (q)rq, q is fixed, and g is the polar transformation function. This representation allows the Schrödinger eigenvalues generated by V to be approximated in terms of those generated by the pure polar potential h(r). In many cases a pair of powers {q1, q2} can be chosen so that the corresponding polar functions {g1, g2} have definite and opposite convexity. For such cases, the spectral approximations provide both upper and lower bounds for the entire discrete spectrum. The example V(r) = ar2 + br2/(1 + cr2) is considered in detail. PACS No. 03.65Ge
Some exact solutions of reduced scalar Yukawa theory
Authors: Darewych J W 
Published: April 2011

The scalar Yukawa model, in which a complex scalar field, ϕ, interacts via a real scalar field, χ, is reduced by using covariant Green functions. It is shown that exact few-particle eigenstates of the truncated QFT Hamiltonian can be obtained in the FeshbachVillars formulation if an unorthodox "empty" vacuum state is used. Analytic solutions for the two-body case are obtained for massless chion exchange in 3+1 dimensions and for massive chion exchange in 1+1 dimensions. Comparison is made to ladder BetheSalpeter, FeynmanSchwinger, and quasipotential results for massive chion exchange in 3+1. Equations for the three-body case are also obtained. PACS Nos.: 11.10.Ef, 11.10.Qr, and 03.70.+k
Article
Authors: Bolina O , Parreira J R 
Published: April 2011

We show that the ground state of the xy model (ferromagnetic orantiferromagnetic) in a transverse magnetic field h --- for any spin value, in any dimension --- is the state with all spins aligned antiparallel to the field when h is greater than some critical value hc. In particular, for the spin-1/2 linear chain, we study the behavior of correlations as functions of the magnetic field. PACS Nos.: 75.10Jm and 64.60.Cm
Article
Authors: Drake GWF , Martin W C 
Published: April 2011

Ionization energies for several of the lower lying S- and P-states of helium are deduced from a combination of theory and a variety of high-precision measurements of transition energies. High-precision variational methods are reviewed and used to subtract the nonrelativistic energy and lowest order α2 au relativistic corrections from the ionization energies. The remaining quantum electrodynamic (QED) shift of order α3 au and higher is calculated in an extended KabirSalpeter formalism and compared with experiment. The comparison verifies the usefulness of the KabirSalpeter formalism for terms at least up to order α4 au, and it verifies an asymptotic 1/n3 scaling law for the two-electron corrections to the Bethe logarithm. The asymptotic scaling law is used to obtain improved semi-empirical estimates for the ionization energies of the higher lying 1sns 1S and 3S states up to n = 10. A revised comprehensive listing is given for the ionization energies of all states of helium up to n = 10 and angular momentum L = 7, together with quantum defect extrapolations for the S-states. PACS Nos.: 31.15.Pf, 31.30.Jv, and 32.10.Hq
Modélisation moléculaire et calcul des fréquences de vibration du sous-réseau perovskite dans CH3NH3PbCl3
Authors: Maalej A , Bahri M , Abid Y , Jaïdane N 
Published: April 2011

The perovskite CH3NH3PbCl3 presents two low-temperature phase transitions [Formula: see text] The various phases are characterized by Raman scattering. We restrict ourselves to the low-frequency domain (10250 cm1), which includes the lattice vibrations, these being more sensitive to the symmetry variations and to the structural phase transitions. Studying the crystal dynamics and the spectral evolution requires a detailed assigment of the Raman spectrum. Consequently, we bring in a molecular model and carry out a theoretical calculation of the vibration frequencies of the perovskite sublattice PbCl3 using the semiempirical self-consistent field method. The model considers the interaction of a PbCl6 octahedron with its six octahedron neighbors. The vibrating cell is thus a 43-atom molecule. The calculated vibration frequencies agree well with the frequencies that have been assigned by a comparaison with the homologous compound CsPbCl3[Journal translation]
The nitric oxide–cGMP signaling pathway plays a significant role in tolerance to the analgesic effect of morphine
Authors: Ozdemir Ercan , Bagcivan Ihsan , Durmus Nedim , Altun Ahmet , Gursoy Sinan 
Published: April 2011

Although the phenomenon of opioid tolerance has been widely investigated, neither opioid nor nonopioid mechanisms are completely understood. The aim of the present study was to investigate the role of the nitric oxide (NO)–cyclic guanosine monophosphate (cGMP) pathway in the development of morphine-induced analgesia tolerance. The study was carried out on male Wistar albino rats (weighing 180–210 g; n = 126). To develop morphine tolerance, animals were given morphine (50 mg/kg; s.c.) once daily for 3 days. After the last dose of morphine was injected on day 4, morphine tolerance was evaluated. The analgesic effects of 3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole (YC-1), BAY 41-2272, S-nitroso-N-acetylpenicillamine (SNAP), NG-nitro-l-arginine methyl ester (L-NAME), and morphine were considered at 15 or 30 min intervals (0, 15, 30, 60, 90, and 120 min) by tail-flick and hot-plate analgesia tests (n = 6 in each study group). The results showed that YC-1 and BAY 41-2272, a NO-independent activator of soluble guanylate cyclase (sGC), significantly increased the development and expression of morphine tolerance, and L-NAME, a NO synthase (NOS) inhibitor, significantly decreased the development of morphine tolerance. In conclusion, these data demonstrate that the nitric oxide–cGMP signal pathway plays a pivotal role in developing tolerance to the analgesic effect of morphine.
Receptor-activating peptides distinguish thrombin receptor (PAR-1) and protease activated receptor 2 (PAR-2) mediated hemodynamic responses in vivo
Authors: Cheung Wai-man , Andrade-Gordon Patricia , Derian Claudia K , Damiano Bruce P 
Published: April 2011

Vascular expression and cellular functions of the thrombin receptor (PAR-1) and protease activated receptor 2 (PAR-2) suggest similar but distinct vascular regulatory roles. The vascular actions of PAR-1 and PAR-2 in vivo were differentiated by monitoring mean arterial pressure (MAP) and heart rate (HR) of anesthetized mice in response to intravenous SFLLRN (0.1, 0.3, and 1 µmol/kg) and SLIGRL (0.1, 0.3, and 1 µmol/kg), the respective receptor-activating sequences for PAR-1 and PAR-2, and TFLLRNPNDK (0.3, 1, and 3 µmol/kg), a synthetic peptide selective for PAR-1. All peptides dose dependently decreased MAP (order of potency: SLIGRL >> SFLLRN >> TFLLRNPNDK). SLIGRL induced a more prolonged hypotension with a slow return to baseline, whereas SFLLRN- and TFLLRNPNDK-induced hypotension was followed by a rapid return towards baseline and a sustained moderate hypotension. SFLLRN and TFLLRNPNDK, but not SLIGRL, decreased HR. Nomega-Nitro-L-arginine methyl ester HCl (L-NAME), an inhibitor of nitric oxide synthesis, attenuated the cumulative hypotensive response to SLIGRL but had no effect on the SFLLRN and TFLLRNPNDK hypotension. However, L-NAME revealed a rebound hypertension in response to SFLLRN and TFLLRNPNDK but not SLIGRL. In conclusion, activation of either PAR-1 or PAR-2 in vivo results in hypotension. In addition, only PAR-1 activation induced hypertension following L-NAME, reflecting concurrent PAR-1-mediated vasoconstriction. Thus, these different hemodynamic responses in vivo suggest distinct physiological or pathophysiological roles for PAR-1 and PAR-2 in local vascular regulation.Key words: protease activated receptor, thrombin receptor, protease activated receptor 2 (PAR-2), arterial pressure.
LABORATORY PROPAGATION OF CEUTHORRHYNCHIDIUS HORRIDUS (COLEOPTERA: CURCULIONIDAE), AN INTRODUCED WEEVIL FOR BIOCONTROL OF CARDUUS THISTLES
Authors: Trumble J.T. , Kok L.T. 
Published: April 2011

AbstractThe development of Ceuthorrhynchidius horridus (Panzer) was observed on five diets consisting of less than 15% dry weight of host-plant material. Adult yields per inoculated larvae were low (less than 1%), although yields from uncontaminated last instars reached as high as 16.6%. Comparisons of diet versus plant-reared weevils showed that (1) larval weight gain at 28 days was significantly greater for plant-reared larvae, (2) plant-reared adults were significantly larger than diet-grown weevils, but there was no difference in fertility, and (3) egg size, viability, and first instar head capsule widths were not significantly different for progeny from diet and plant-reared weevils.
TOXICITY OF INSECTICIDES TO DOUGLAS-FIR TUSSOCK MOTH, ORGYIA PSEUDOTSUGATA (LEPIDOPTERA: LYMANTRIIDAE): II. RESIDUAL TOXICITY AND RAINFASTNESS
Authors: Robertson Jacqueline L. , Boelter Lucille M. 
Published: April 2011

AbstractFourth instar Douglas-fir tussock moth were used to assess the residual toxicity of 10 insecticides applied to Douglas-fir seedlings. Among the 10, carbaryl compared most favorably to DDT. Rainfastness of the insecticides was tested by means of a rainchamber. Permethrin, diflubenzuron, and carbaryl were least affected by simulated rainfall, while acephate and trichlorfon were seriously and adversely affected.
THE LARCH CASEBEARER (LEPIDOPTERA: COLEOPHORIDAE) AND ITS PARASITES: I. MAINTAINING YEAR-ROUND AVAILABILITY OF LARCH FOLIAGE AND THE CASEBEARER FOR PARASITE REARING
Authors: Ryan R. B. 
Published: April 2011

AbstractFoliage on potted trees or cut branches of western larch, Larix occidentalis Nutt., served as food for rearing Coleophora laricella (Hbn.) during winter and spring. Potted trees were induced to flush by laboratory simulation of fall, winter, and spring to provide foliage the year around. The treatment was 2 months at a short-day photoperiod (SD = 12-h light: 12-h dark), followed by 2 months of darkness at 2 °C, then growth in a greenhouse at long day (LD = 18-h light: 6-h dark). C. laricella could be collected from the field for further rearing during much of the year. Year-round availability of all stages, however, was realized by rearings starting from laboratory-mated moths and eggs laid on potted trees. To promote continued development to the adult stage, a SD-LD-SD sequence of 6 weeks – 2 weeks – 3 weeks duration, then LD was imposed.
OLEORESIN CHARACTERISTICS AND SUSCEPTIBILITY OF FOUR SOUTHERN PINES TO SOUTHERN PINE BEETLE (COLEOPTERA: SCOLYTIDAE) ATTACKS
Authors: Hodges John D. , Elam William W. , Watson William F. , Nebeker T. Evan 
Published: April 2011

AbstractAll four major southern pines can be killed by the southern pine beetle, but loblolly and shortleaf are much more susceptible than longleaf and slash. Oleoresin from more than 50 trees of each species was tested for composition and amount of monoterpenes and resin acids, viscosity, flow (rate, duration, and amount), and rate of crystallization. Discriminant function analyses were used to classify the loblolly and shortleaf trees as to probable resistance. The best classification used physical properties (total flow, flow rate, viscosity, time to crystallization). Supposedly resistant and susceptible trees were subjected to controlled attack, and the chemical and physical properties of four loblolly pines that survived natural attack were measured. Resistance is strongly related to the physical properties of the oleoresin, and can be predicted by these properties. Loblolly and shortleaf trees with “average” properties usually succumb to 100 or more attacks per sq. m of bark surface. Several trees classified as resistant survived a much higher rate of attack.
OVOVIVIPARITY AND NYMPHAL SEASONAL MOVEMENTS OF CALLIBAETIS SPP. (EPHEMEROPTERA: BAETIDAE) IN A POND IN SOUTHWESTERN QUEBEC
Authors: Gibbs K. Elizabeth 
Published: April 2011

AbstractCallibaetis ferrugineus (Walsh) and C. fluctuons (Walsh) nymphs moved from the shallow, peripheral area of a pond during the late summer and autumn to the deeper water where they overwintered. In the spring they returned to the peripheral area where they were found throughout the summer. C. ferrugineus and C. fluctuans are ovoviviparous. A relationship between ovoviviparity and seasonal movements of the nymphs is suggested.
WITHIN AND BETWEEN TREE VARIATION OF LIVE AND PARASITIZED DOUGLAS-FIR TUSSOCK MOTH, ORYGIA PSEUDOTSUGATA (LEPIDOPTERA: LYMANTRIIDAE), COCOONS ON WHITE FIR IN CENTRAL CALIFORNIA AND ITS IMPLICATIONS FOR SAMPLING
Authors: Luck Robert F. , Dahlsten Donald L. 
Published: April 2011

AbstractThe distribution of Douglas-fir tussock moth, Orgyia pseudotsugata (McD.), cocoons was studied within and between the crowns of white fir, Abies concolor ((Gord. and Glend.) Lindl.), at six locations in the central Sierra Nevada Mountains of California. The within tree, between tree, and between plot distribution of cocoons in the crown, categorized by sex, mortality (including parasitization), and stage (larva or pupa) were analyzed. Only cocoons containing female pupae varied in their distribution within the tree and they were concentrated in the bottom third of the live crown but their densities at any one level bore little relation to those in the other levels within the crown. Cocoon density varied significantly between plots and between trees within plots. Total parasitism did not vary significantly between plots. The variable within tree distribution of cocoons containing female pupae and their increased percentage parasitism relative to those containing male pupae, suggested that the live crown should be stratified. A sample unit consisting of two branches selected from the midpoint of each of the three crown levels (total: 6 branches) sampled approximately 5% of the live crown of white fir. The relation between the number of sample trees and mean cocoon density at three levels of precision is provided.
PEST STATUS AND ECONOMIC THRESHOLDS OF THE TARNISHED PLANT BUG, LYGUS LINEOLARIS (HEMIPTERA (HETEROPTERA): MIRIDAE), ON GREEN BEANS IN QUEBEC
Authors: Stewart R. K. , Khattat A. R. 
Published: April 2011

AbstractAdult and nymphal populations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), on “Contender” green beans, Phaseolus vulgaris L., were sampled during the summers of 1971–1972. Sweep net and D-Vac® suction apparatus samples were taken concurrently, and both estimates were compared by regression analysis.The tarnished plant bug reached levels above the economic injury levels for both early and late crops in 1971–1972. The economic threshold was determined as 0.5 insect/10 plants below the economic injury level.
GENETIC DIVERGENCE AMONG EASTERN NORTH AMERICAN CONE BEETLES,CONOPHTHORUS(COLEOPTERA: SCOLYTIDAE)
Authors: de Groot Peter , Harvey George T. , Roden Pat M. 
Published: April 2011

AbstractGenetic divergence among populations of cone beetles,Conophthorus banksianaeMcPherson,C.coniperda(Schwarz), andC.resinosaeHopkins, was assessed by isozyme electrophoretic data. All but one of the eight loci examined were polymorphic, and one locus (Pgi) was sex-linked forC.coniperda. Genotype frequencies generally met Hardy-Weinberg expectations, and fixation index (FST) values indicated low-to-moderate genetic differences among conspecific populations. Fixed allele differences were detected at two loci, Pgi and Dia-2, which separatedC.resinosaefromC.coniperda, and thus confirmed their specific status established previously by morphological, karyological, and other biochemical characters. Electrophoretic data strongly suggestedC.coniperdadoes not attack red pine cones, andC.resinosaedoes not attack white pine cones. No diagnostic loci were found to separateC.resinosaefromC.banksianae. Phenetic clustering and pairwise comparisons of genetic distance coefficients indicated very little genetic divergence betweenC.resinosaeandC.banksianae. These data were interpreted as failing to reject the null hypothesis thatC.resinosaeandC.banksianaeare one species, an interpretation consistent with available taxonomic evidence from ecological, karyological, and other biochemical characters.
TEMPORAL AND SPATIAL PATTERNS OF RESOURCE USE AMONG NICROPHORUS CARRION BEETLES (COLEOPTERA: SILPHIDAE) IN A SPHAGNUM BOG AND ADJACENT FOREST NEAR OTTAWA, CANADA
Authors: Beninger Clifford W. , Peck Stewart B. 
Published: April 2011

AbstractThis study examines reproductive resource acquisition and utilization among Nicrophorus carrion beetles (Coleoptera: Silphidae) in two different and adjacent habitats. The proportion of small carrion resource (dead mice, Mus musculus L.) used by Nicrophorus and other scavengers in a Sphagnum bog did not differ significantly from that used in a nearby forest. Among congeneric Nicrophorus, N. vespilloides Herbst reproduced on small carrion exclusively in the Sphagnum bog, whereas a closely related species, N. defodiens Mannerheim, reproduced only in the nearby mixed forest. Nicrophorus sayi Laporte, N. orbicollis Say, and N. tomentosus Weber were rarely associated with small carrion resource in the bog, and reproduced primarily in the forest during the spring, summer, and fall, respectively. A significant positive correlation between brood size and weight of larval carrion resource was found for N. vespilloides.
A SYNOPSIS OF THE WORLD FAUNA OFMYZOCALLIS(HOMOPTERA: APHIDIDAE)
Authors: Richards W. R. 
Published: April 2011

AbstractMyzocallisPasserini as here understood consists of the following 30 species:agrifolicolaRichards,asclepiadis(Monell),bella(Walsh),borneriStroyan,carpini(Koch),castanicolaBaker,coryli(Goeze),discolor(Monell),elliottiBoudreaux and Tissot,ephemerataRichards,exultansBoudreaux and Tissot,frisoniBoudreaux and Tissot,glandulosaHille Ris Lambers,granovskyiBoudreaux and Tissot,kuricola(Matsumura),longirostrisRichards,longiunguisBoudreaux and Tissot,melanoceraBoudreaux and Tissot,meridionalisGranovsky,mimicaRichards,multisetisBoudreaux and Tissot,myricae(Kaltenbach),occultaRichards,pepperiBoudreaux and Tissot,picta(Ferrari),punctata(Monell),rostropunctataRichards,spinosaBoudreaux and Tissot,tuberculataRichards,walshii(Monell). A key and notes on the distribution and relationships of each species are given. A host index has been compiled.
THE CHAITOPHORINAE OF CANADA (HOMOPTERA: APHIDIDAE)
Authors: Richards W. R. 
Published: April 2011

AbstractThis paper includes illustrations, descriptions, and keys to the following eight genera and 42 species:Atheroides serrulatusHaliday,Caricosipha paniculataeBÖrner,Chaetosiphella berlesei(del Guercio),Chaitophorus abditus(Hottes),Chaitophorus albicentrusnew species,Chaitophorus canensRichards,Chaitophorus crucis(Essig),Chaitophorus delicatusPatch,Chaitophorus longipesTissot,Chaitophorus knowltoniHille Ris Lambers,Chaitophorus macgillivrayaenew species,Chaitophorus macrostachyae(Essig),Chaitophorus minutus(Tissot),Chaitophorus monelli(Essig),Chaitophorus neglectusHottes and Frison,Chaitophorus nigraeOestlund,Chaitophorus nigricentrusnew species,Chaitophorus nodulosusRichards,Chaitophorus nudusRichards,Chaitophorus pallipesnew species,Chaitophorus populialbae(Boyer de Fonscolombe),Chaitophorus populicolaThomas,Chaitophorus populifolii(Essig),Chaitophorus pusillusHottes and Frison,Chaitophorus pustulatusHille Ris Lambers,Chaitophorus saliciniger(Knowlton),Chaitophorus versicolor(Koch),Chaitophorus viminalisMonell,Chaitophorus viminicolaHille Ris Lambers,Laingia psammaeTheobald,Periphyllus americanus(Baker),Periphyllus brevispinosusGillette and Palmer,Periphyllus californiensis(Shinji),Periphyllus lyropictus(Kessler),Periphyllus negundinis(Thomas),Periphyllus testudinacea(Fernie),Pseudopterocomma canadensisRichards,Pseudopterocomma hughi(MacGillivray),Sipha agropyrensis(Gillette),Sipha flava(Forbes),Sipha glyceriae(Kaltenbach),Sipha kurdjumoviMordwilko. A host index has been compiled from the material studied and the literature cited.
GUIDE TO THE GEOMETRIDAE OF CANADA (LEPIDOPTERA): II. SUBFAMILY ENNOMINAE.
Authors: McGuffin W.C. 
Published: April 2011

SummaryThis is the third in a series of manuals designed to facilitate the recognition of the Geometridae of Canada. In the introductory section key characters are given for the identification of Geometridae in adult, larval, and pupal stages. A generalized description of each stage is followed by a key to the subfamilies of the Geometridae and a synopsis of the characters of the Ennominae. Keys to the five parts of the Ennominae (sometimes broken down into tribes) as they are to be treated in this series of manuals are supplemented by text descriptions, line drawings, and colour photographs. The distribution of many of the 45 species is shown on 29 maps. These maps and the studies of the writer suggest the potential value of collecting along some of the major Canadian waterways, such as the Saskatchewan River. This along with collecting in the short-grass prairie and its stream beds in Alberta and Saskatchewan and faunal investigations in the northern end of the Appalachian Mountains in Quebec and New Brunswick should add much to our distribution records.On the basis of adult, larval, and pupal characters a phylogenetic chart of the boarmid group has been constructed.
A REVISION OF THE GENUSLORDITHONTHOMSON OF NORTH AND CENTRAL AMERICA (COLEOPTERA: STAPHYLINIDAE)
Authors: Campbell J. M. 
Published: April 2011

AbstractThe species of the genusLordithonThomson (Staphylinidae: Tachyporinae) of North and Central America are revised. Thirty-seven species are recognized. Sixteen new species are described:scutellaris,appalachianusandnotabilisfrom eastern North America;difficilisandoregonusfrom the Pacific Northwest;fungicolatranscontinental in North America; andnubicola,dubius,newtoni,howdeni,ashei,hidalgoensis,antennatus,consors,blandus, andoreophilusfrom Mexico. The following species names are placed in synonymy:cascadensis hatchiMalkin (=cascadensisMalkin);cincticollisSay (=thoracicus thoracicusFabricius);occiduusCasey (=thoracicus thoracicusFabricius);alticolaSharp (=obliquusSharp);kelleyiMalkin (=bimaculatusCouper) andelefasBernhauer (=longicepsLeConte).L.venustusMelsheimer is reduced to a subspecies ofthoracicusFabricius. The speciesfestivusSharp,obliquusSharp,smithiBernhauer, andmexicanusBernhauer are transferred toLordithonfrom the genusBolitobius.Lordithon lunulatusis doubtfully recorded from North America for the first time.The usage of the generic group namesLordithonThomson,BolitobiusSamouelle,MegacronusStephens,BryocharisBoisduval and Lacordaire,Carphacisdes Gozis, andBolitobusTottenham is discussed. The genusLordithonis divided into two subgenera,LordithonThomson andBolitobusTottenham (notBolitobiusSamouelle). The male aedeagus and other major diagnostic characters are illustrated and the distribution of each species mapped.The speciesrubescensHatch,varionsHatch,fenderiHatch andbiseriatusMannerheim are transferred fromLordithonto the genusBryoporusKraatz.Lectotypes are designated for the following species:nigerGravenhorst,axillarisGravenhorst,festivusSharp,anticusHorn,poecilusMannerheim,facilisCasey,arizonensisBernhauer,obliquusSharp,alticolaSharp,smithiBernhauer,mexicanusBernhauer,cinctusGravenhorst,gentilisLeConte,elefasBernhauer androstratusLeConte. Neotypes were designated for:angularisSachse,trimaculatusSay,cincticollisSay,obsoletusSay andatricaudatusSay.