15,818 research outputs found
Portrait photograph of M. A. Atkinson for member roster
No full textPortrait photograph of M. A. Atkinson for member rosterhttps://mavmatrix.uta.edu/specialcollections_wdsmithphotography/11230/thumbnail.jp
Cactopinus rhettbutleri Atkinson, sp. n.
No full textCactopinus rhettbutleri Atkinson, sp. n. Male: ( Figs. 1–2). Color black, length 1.87 mm (1.8–2.05), width 0.85 mm (0.8–1.0), length/width 2.19 (1.9–2.4) (n=11). Head: Dense fringe of downwards projecting, fimbriate setae along entire width of epistomal margin, covering base of mandibles; similar, smaller brushes at base of mandibles at genal margin. Epistoma raised for its entire width, with a single, small tubercle at each end, rising gradually in middle to base of horns. Horns joined at base, parallel throughout their length along interior margins, broadened distally; anterior surface shining, deeply, coarsely punctured, with yellowish setae arising from punctures; apex of horns digitate, impunctate; punctures on external margins of horns with raised lateral elevations; the most distal of these with a prominent lateral process, giving the horn a forked appearance; a large brush of yellow setae arising from this cleft, length of setae exceeding the apex, similar in size and color to those of epistomal brush. Frons concave in profile, shallowly concave in medial area between eyes, margins of concavity gradual, not acute; frontal surface above horns coarsely punctured, largely without setae; surface shining. Antennal club approximately twice as long as wide; basal half corneous, 2 straight sutures evident on distal half, lined with yellow setae. Pronotum: Asperities concentrated behind middle; summit acute, slightly projected posteriorly beyond base; asperities on anterior slope sparse, separated, tooth-like. Postero-lateral portions of pronotum smooth, shining, with widely spaced, deep punctures; this area with a clear demarcation from densely placed, confused asperities on summit. Acute setae associated with punctures throughout; those in antero-lateral areas and along lateral margins of raised summit twice as long as others, as long as antennal scape. Elytra: Striae deeply punctured but not impressed, punctures separated by less than their diameter. Interstriae twice as wide as striae with clearly marked, uniseriate punctures that are smaller than those of the striae; surface smooth and shining; vestiture of erect golden interstrial setae, their length less than that of the interstrial width. Declivity steep; striae 1 impressed with sutural interstria elevated, interstria 2 slightly widened with a small number of widely spaced granules; interstria 3 elevated, highest in middle, but not higher than the sutural interstria; all declivital interstriae (reduced in 2) with small uniseriate granules associated with interstrial punctures; strial punctures not granulate. Female: (Fig. 3). Length 1.90 mm (1.8–2.05), width 0.86 mm (0.9–0.95), length/width 2.13 (2.1–2.3) (n=11). Frons weakly concave between eyes; surface densely pubescent with setae uniform in length throughout, about 2/3 length of antennal scape, becoming shorter at vertex; brush of marginal setae along epistoma similar to that of male; epistoma without any trace of lateral elevation. Pronotum and elytra similar to that of male. Type material. Holotype: male. Oaxaca, 7 km S Totolapan, road to Santa María Zoquitlán (16.6231 N; 96.3261 W), 982 m, 24-VII-2014, Polaskia sp., T.H. Atkinson & A. Burgos S., THA-1064 (Deposited in the Coleccion Nacional de Insectos (CNIN), Instituto de Biología, Universidad Nacional Autónoma de México). Allotype: female: same data (CNIN). Paratypes: Oaxaca: 7 km S Totolapan, road to Santa María Zoquitlán (16.6231 N; 96.3261 W), 982 m, 24-VII- 2014, Polaskia sp., T.H. Atkinson & A. Burgos S., THA-1064 (UTIC, 6); 2 km N Totolapan (16.68644 N; 96.32061 W), 1,004 m, 1-VII-2009, Escontria chiotilla, T.H. Atkinson, THA-893 (TAMU, 2; UTIC, 3); 5 km S Totolapan, road to Santa María Zoquitlán (16.6515 N; 96.3156 W), 700 m, 24-VII-2014, Polaskia sp., T.H. Atkinson & A. Burgos S., THA-1060 (TAMU, 2); Santiago Dominguillo (17.6337 N; 96.9141 W), 870 m, 2-VII- 2009, Escontria chiotilla, T.H. Atkinson, THA-896 (UTIC, 3); Nejapa (16.6096 N; 96.0134 W), 659 m, 23-VIII- 2014, T.H. Atkinson & A. Burgos S., THA-1058 (CEAM, 5). Puebla: Coxcatlán (18.2446 N; 97.156 W), 1070 m; 19-I-2012, Escontria chiotilla; T.H. Atkinson, THA-979 (CNIN, 2; CEAM, 2; TAMU, 7; UTIC, 6). Notes. As previously discussed (Atkinson, 2010) the male epistomal horns are not segmented. In most species, especially those with the longest horns, there are deep punctures along most of the length of the horn that appear to confer some flexibility by allowing it to bend. In C. rhettbutleri the margins of the subapical punctures are raised into projections. This may be seen in several punctures but is always most prominent in those closest to the apex of the horns. In some males from the Coxcatlán population the epistomal horns are much reduced in size (Fig. 2 B,C,D). In intermediate cases the distal digitate extension is absent or much reduced but the margins of the subapical punctures are still expanded laterally and the more distal punctures on the lateral margins still have a lateral process arising from them and show the bifid, or forked apex. In other species of Cactopinus for which large numbers of specimens from multiple collections are available, there appears to be considerable variation in the length of male horns. This needs to be studied and possibly descriptions and keys will have to be modified. Biology. This species has been collected in the dried ribs of its hosts, multiply branched arborescent cacti. As is the case with most other cactus-breeding Cactopinus species, successful breeding occurs in portions of stems that have dried out to a hard, leathery consistency without the black discoloration associated with decay. Under these conditions the dried tissue is dark yellowish brown and tacky to the touch. This situation most commonly occurs in erect, dead stems still attached to the host. Galleries are initiated at the areoles (clumps of spines that are found along the ridges of the ribs). Species of Polaskia are restricted to the states of Oaxaca and Puebla, roughly within the area where this species was collected. Escontria chiotilla has a broader distribution which includes the Balsas depression of the states of Guerrero and Michoacán. The majority of the species of Cactopinus that breed in columnar or arborescent cacti use hosts in the subtribe Stenocereinae (Gibson et al. 1986). Other reported hosts in this subtribe include Stenocereus and Myrtillocactus. The Escontria and Polaskia also belong to this group and are most closely related to Myrtillocactus. Etymology. This species is named in honor of Rhett Butler for his work in conservation and environmental education. Diagnosis. This species is most readily distinguished by the unique, laterally expanded epistomal horns in the male that appear to be apically forked. The wide variation in horn length documented here for C. rhettbutleri means that some specimens can not be reliably identified at this point. The subapical branching that is typical of this species is visible even in males with reduced horns (Fig. 2 B,C) but not in extreme cases (Fig. 2 D). Examination of long series of other species has also shown wide intraspecific variation in male horn length (unpublished) that effectively means that single male specimens of other species may also present problems in identification. At this point females cannot be reliably identified although this could be accomplished with further study. Based on the abundance of characters present in the known species it should be possible to write new keys that will accommodate both females and males with reduced horns. This is beyond the scope of the current paper. Cactopinus rhettbutleri will key out to couplet 11 in the latest generic key (Atkinson, 2010). Modified couplets are shown below. 11(8) Frons curved in lateral profile, but flat longitudinally; pronotal asperities blunt, weakly developed; declivity with relatively few, small granules on interstriae. 1.2–1.4 mm. Puebla......................................... cactophthorus Wood - Frons weakly to prominently concave in central area between eyes; pronotal asperities sharply elevated, chisel shaped declivity with prominent granules on interstriae 2 and higher.......................................................... 12 12(11) Horns reaching or exceeding upper level of frons, apical portions digitate; interstria 1 on declivity not impressed, interstriae 3 not prominently elevated............................................................................... 13 - Horns not reaching upper level of frons, apical portion not digitate, interstria 1 on declivity strongly impressed, interstriae 3 prominently elevated................................................................................. 13a 13(12) Male horns not expanded distally, digitate apical portions of horns divaricate; 1.5–1.6 mm. In Neobuxbaumia. Morelos, Puebla.......................................................................................... burjosi Wood - Male horns expanded distally, prominent lateral process below digitate apex giving forked appearance. In Escontria, Polaskia. Oaxaca, Puebla....................................................................... rhettbutleri Atkinson 13(13a)Frons with prominent concavity in middle of frons; outer sides of horns parallel, inner sides angled making obvious “V” shape; antennal sutures straight. 1.6–1.9 mm. In Stenocereus. Oaxaca, Querétaro................................ niger Wood - Frons shallowly concave, concavity not well defined; inner sides of horns not strongly angled; antennal sutures bisinuate. 1.4– 1.7 mm. In Stenocereus spp. Jalisco............................................................. setosus WoodPublished as part of Atkinson, Thomas H., 2016, A new species of Cactopinus Schwarz from central Mexico (Coleoptera: Curculionidae: Scolytinae), pp. 196-200 in Zootaxa 4189 (1) on pages 196-200, DOI: 10.11646/zootaxa.4189.1.13, http://zenodo.org/record/16573
Key exchange using Chebychev polynomials
No full textWe propose a variant of the well known Diffie-Hellman algorithm which uses Chebychev polynomials
The Extended Atkinson Family and Changes in the Expenditure Distribution: Spain 1973/74-2003
No full textThis paper emphasizes the properties of a family of inequality measures which extends the Atkinson indices and is axiomatically characterized by a multiplicative decomposition property where the withingroup component is a generalized weighted mean with weights summing exactly to 1. This family contains canonical forms of all aggregative inequality measures, each bounded above by 1, has a useful and intuitive geometric interpretation and provides an alternative dominance criterion for ordering distributions in terms of inequality. Taking the Spanish Household Budget Surveys (HBS) for 1973/74, 1980/81, and 1990/91 and the more recent Continuous HBS for 2003, we show the advantages and possibilities of this extended family in regard to completing and detailing information in studies of inequality focussing on the tails of the distribution and on the changes in the distribution when the population is partitioned into population subgroups.inequality measurement, Atkinson indices
Tackling the burden of injury in Australasia: developing a binational trauma registry
No full textThe document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Existing trauma registries in Australia and New Zealand play an important role in monitoring the management of injured patients. Over the past decade, such monitoring has been translated into changes in clinical processes and practices. Monitoring and changes have been ad hoc, as there are currently no Australasian benchmarks for “optimal” injury management. A binational trauma registry is urgently needed to benchmark injury management to improve outcomes for injured patients.Tamzyn M Davey, Cliff W Pollard, Leanne M Aitken, Mark Fitzgerald, Nicholas Bellamy, Daniel Cass, Peter D Danne, William M Griggs, Peter A Cameron, Robert N Atkinson, James Hamill, Sudhakar Rao, Drew B Richardson and Christine O'Conno
Analysis of CDC social control measures using an agent-based simulation of an influenza epidemic in a city
No full textBackground: the transmission of infectious disease amongst the human population is a complex process which requires advanced, often individual-based, models to capture the space-time details observed in reality.Methods: an Individual Space-Time Activity-based Model (ISTAM) was applied to simulate the effectiveness of non-pharmaceutical control measures including: (1) refraining from social activities, (2) school closure and (3) household quarantine, for a hypothetical influenza outbreak in an urban area.Results: amongst the set of control measures tested, refraining from social activities with various compliance levels was relatively ineffective. Household quarantine was very effective, especially for the peak number of cases and total number of cases, with large differences between compliance levels. Household quarantine resulted in a decrease in the peak number of cases from more than 300 to around 158 for a 100% compliance level, a decrease of about 48.7%. The delay in the outbreak peak was about 3 to 17 days. The total number of cases decreased to a range of 3635-5403, that is, 63.7%-94.7% of the baseline value.When coupling control measures, household quarantine together with school closure was the most effective strategy. The resulting space-time distribution of infection in different classes of activity bundles (AB) suggests that the epidemic outbreak is strengthened amongst children and then spread to adults. By sensitivity analysis, this study demonstrated that earlier implementation of control measures leads to greater efficacy. Also, for infectious diseases with larger basic reproduction number, the effectiveness of non-pharmaceutical measures was shown to be limited.Conclusions: simulated results showed that household quarantine was the most effective control measure, while school closure and household quarantine implemented together achieved the greatest benefit. Agent-based models should be applied in the future to evaluate the efficacy of control measures for a range of disease outbreaks in a range of settings given sufficient information about the given case and knowledge about the transmission processes at a fine scal
TIME EVOLUTION OF SHORT-LIVED MOLECULAR SPECIES OBSERVED BY INTRACAVITY LASER ABSORPTION SPECTROSCOPY
No full textAuthor Institution: Laboratoire de Spectcometrie Physique Universite Scientifique et Medicale de Grenoble BP68 38042, Saint Martin d'Heres; Department of Chemistry, Davidson College, Davidson; Department of Chemistry, Syracuse University SyracuseWe report the feasibility of using CW intracavity laser absorption spectroscopy (ICLAS) as a probe in detecting transient species generated by pulsed laser photolysis. The method of detection uses a time-generated CW laser beam and time-resolved spectra which are delayed with respect to the photolysis pulse. Variable time delays and a constant generation time have been used to detect the time dependence of the absorbing species at times as short as a few microseconds. We applied the technique to the study of the time evolution of the formation of the free radical HCO generated by photolysis of gas-phase acetaldehyde at pressures down to tens of mtorr. We have also found that the ultimate sensitivity of the ICLAS technique is limited mainly by the mechanical stability of the cavity. M. Chenevier, M. A. Melieres, F. Stoeckel, to be published G. H. Atkinson, A. H. Laufer and M. J. Kurylo, J. Chem. Phys. 59 (1973) 350. G. H. Atkinson, T. M. Heimlich and M. W. Schuyler, J. Chem. Phys. 66 (1977 5005. A. J. Gill and G. H. Atkinson, Chem. Phys. Letters, 64 (1979) 426. R, J. Gill, W. D. Johnson and G. H. Atkinson, Chem. Phys. 58 (1981) 29
Corthylus latisetosus Atkinson 2020, new species
No full textCorthylus latisetosus Atkinson, new species Fig. 9 E, F; Fig. 12 A–D Diagnosis. This species can be recognized by its small size. The circumdeclivital ring is about 80% complete, with the raised lateral margin not present near the base of the declivity. Unlike several other species (e.g., C. ibarrai), the face of the declivity is not strongly recessed with respect to the circumdeclivital ring. Most declivital interstriae have rows of stout, truncate setae. Female. Unknown. Male. Length: 1.55 mm, maximum width: 0.6 mm; length of elytra: 0.8 mm; length to width: 2.6; elytral length/ total length: 0.52; elytral length/width: 1.33. (n = 1). Frons flattened, shining, without vestiture. Surface finely reticulate, with widely spaced, shallow punctures. Frontal setae absent. Epistomal margin elevated, with a transverse impression immediately above. Antennal club almost oval; suture 1 marked by external groove, partly septate; suture 2 marked by external groove. Anterior margin of pronotum with low asperities, the central pair largest. Anterior slope with short, weakly elevated asperities. Pronotal summit low, slightly anterior to center. Disc smooth, shining, with widely separated, shallow punctures. Strial punctures on elytral disc similar in size, slightly confused. Surface smooth, shining, striae not impressed. Some interstrial punctures with short setae in lateral areas. Declivity abruptly truncate with a prominent circumdeclivital elevation from apex, extending 80% of the distance to the declivital base. Face of declivity not impressed with respect to elevated margin. Declivital interstriae 1 weakly elevated, subserrate; elevation not reaching base or apex of declivity. Strial and interstrial punctures similar in size, partly confused. Short, erect, truncate, flattened setae present on most declivital interstriae, their length less than spacing within rows or between rows. Type material. Holotype male. Mexico: Michoacán: Uruapan, Zumpimito, 19.3336 N, 102. 0592 W, 12-XI-2016; flight intercept trap, M. Lázaro D. (CNIN). Etymology. The name was chosen because of the wide, truncate interstrial setae on the face of the declivity.Published as part of Atkinson, Thomas H., 2020, New species, new records and synonymy of Mexican Corthylus Erichson, 1834 (Coleoptera: Curculionidae: Scolytinae), pp. 1-25 in Insecta Mundi 2020 (792) on pages 16-19, DOI: 10.5281/zenodo.456489
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