16,411 research outputs found

    The Nomenclatural Status of Saperda Inordata Say (Coleoptera: Cerambycidae)

    Get PDF
    Excerpt: Confusion as to the identity and proper name of our common Saperda on trembling aspen, Populus tremuloides Michaux, in eastern North America should be clarified. The confusion has arisen from three reasons: (1) LeConte failed to distinguish S. concolor Lec. (1852) from S. irornata Say (1824); (2) Say\u27s type material was destroyed or lost which makes verification impossible; and (3) S. inornata varies from light to dark in overall appearance. The former two points are discussed here and the latter will be covered in a separate article. Authors since LeConte\u27s time have used a variety of binominal and trinominal designations for this species. In 1924 J. 0. Martin suggested that the name inornata, which had been placed in the Genus Mecas, really belonged in the Genus Saperda and that S. inornata should be reinstated replacing LeConte\u27s concolor which Martin, followed by Breuning (1952), considered a synonym of inornata. Despite Martin\u27s suggestion, S. concolor is in common use today. However, a search of the literature produced evidence which substantiates Martin\u27s claim that inornata must stand (Nord, 1968). A summary of this search is presented here in detail and a neotype has been proposed so that the nomenclature will be stabilized (Nord and Knight, 1970)

    The Geographic Variation of Saperda Inornata Say (Coleoptera: Cerambycidae) in Eastern North America

    Get PDF
    Excerpt: During the summers of 1962 and 1963 a study of the life history and behavior of what was thought to have been Saperda moesta LeConte in trembling aspen, Populus tremuloides Michaux, was completed in northern Michigan (Nord, 1968). After the field study, it became apparent that the original identification was doubtful. Furthermore, there was a possibility that two species were present in the study areas, thus the biological data collected may have represented not one but two species

    The Distribution of Saperda Inornata and Oberea Schaumii (Coleoptera: Cerambycidae) within the Crowns of Large Trembling Aspens, Populus Tremuloides

    Get PDF
    The larvae of Saperda inornata Say and Oberea schaumii LeConte inhabit the stems of trembling aspen (Populus tremuloides Michaux) root suckers and the twigs of larger trees. Nord et al. (1972a, 1972b) reported the biologies of these species in Upper Michigan and northern Wisconsin. S. inornata has a one or two year life cycle, probably depending on how early the egg is laid. Most (77.5%) 0. schaumii develop in three years while 5.0% require only two years and 17.5% require four years to develop. Knight (1963) described the distribution of galleries made by S. inornata and 0. schaumii in the crowns of large trembling aspen, P. tremuloides, in Upper Michigan. Similar distribution data were gathered from 180 large trembling aspen felled in a survey designed to determine the relative abundance of S. inornata and 0. schaumii in stands of different site quality (Nord and Knight 1972b). The analysis of that distribution data and comparisons with that of Knight (1963) are presented here. Inter- and intra-specific competition in light of the results and other behavioral information are discussed

    The Importance of Saperda Inornata and Oberea Schaumii (Coleoptera: Cerambycidae) Galleries as Infection Courts of Hypoxylon Pruinatum in Trembling Aspen, Populus Tremuloides

    Get PDF
    (excerpt) Trembling aspen, Populus tremuloides Michaux, and bigtooth aspen, P. grandidentata Michaux, are hosts of numerous species of injurious insects and microorganisms (Harrison 1959). Only a few of those organisms, however, are directly responsible for mortality of healthy trees. The fungus Hypoxylon pruinatum (Klotzsche) Cke. is most important in that respect, killing 1-2%o f the standing volume annually in the Lake States (Anderson 1964). It invades and spreads in cambial tissue, killing it and eventually the branch or stem by girdling. Initially, a canker appears as a sunken, yellowish-orange area in the bark (Anderson 1956). In a later stage the outer bark raises in blister-like patches and sloughs off exposing blackened, crumbling cortex

    The Relationship of the Abundance of \u3ci\u3eSaperda Inornata\u3c/i\u3e and \u3ci\u3eOberea Schaumii\u3c/i\u3e (Coleoptera: Cerambycidae) in Large Trembling Aspen, \u3ci\u3ePopulus Tremuloides\u3c/i\u3e, to Site Quality

    Get PDF
    Saperda inornata Say and Oberea schaumii LeConte are cerambycids that inhabit the stems of trembling aspen, Populus tremuloides Michaux, root suckers and the twigs of larger trees. The biologies of those species in northern Wisconsin and Upper Michigan were reported by Nord et al. (1972a and 1972b). S. inornata oviposits on the cambium under horseshoe- or shield-shaped egg niches gnawed in the outer bark by the female. The term egg niche, connotes an oviposition place prepared by the female using the mandibles and ovipositor (Linsley 1959). There are usually 2 or 3 egg niches at one level on the stem or twig, and a globose gall consisting of callus tissue forms there. The larvae feed in the cambial and callus tissue around the gall and require 1 or 2 years to complete development. The 0. schaurnii female gnaws an elongate, rectangular egg niche in the outer bark and deposits an egg on the cambium beneath it. The larva bores downward from the egg niche in the wood. Most individuals require 3 years to complete the life cycle; but some take only 2 years, while others take 4 years. A survey designed to determine the importance of the egg niches and galleries of S. inornata and 0. schaumii as infection courts of Hypoxylon pruinatum (Klotzsche) Cke. in large trembling aspen was begun in 1962 in Iron and Ontonogan Counties, Michigan. The data from that survey indicated that abundance of borers might be correlated with the site quality of the stand. Therefore in 1963 the survey was redesigned to detect differences in abundance between stands of different site quality. Since the redesign concerned only the selection of stands, not the sampling procedures used within the stand, most of the trees sampled in 1962 were incorporated into the redesigned survey. The data collected in conjuction with the survey also make possible conclusions regarding the distribution of borer galleries within the crowns of large trees. Those results and a discussion of competition between S. inornata and 0. schaurnii are given in another paper (Nord and Knight, 1972a). The incidence of H. pruinatum in the galleries was reported by Nord and Knight (1972b)

    Associated Insects Reared from Galls of Saperda Inornata (Coleoptera: Cerambycidae) on Trembling Aspen in Michigan

    Get PDF
    The poplar gall Saperda, Saperda inornata Say, is a common pest of trembling aspen, Populus tremuloides Michx, in Michigan forests. Through its egg-laying activities and larval feeding, this insect causes wood defects and tree mortality (Graham et al., 1963). While studying natural populations of this insect (Grimble and Knight, 1970), we collected many galls and found through rearing and dissection that they harbor a large and varied insect fauna

    Synapse-Centric mapping of cortical models to the spiNNaker neuromorphic architecture

    Get PDF
    While the adult human brain has approximately 8.8 × 1010 neurons, this number is dwarfed by its 1 × 1015 synapses. From the point of view of neuromorphic engineering and neural simulation in general this makes the simulation of these synapses a particularly complex problem. SpiNNaker is a digital, neuromorphic architecture designed for simulating large-scale spiking neural networks at speeds close to biological real-time. Current solutions for simulating spiking neural networks on SpiNNaker are heavily inspired by work on distributed high-performance computing. However, while SpiNNaker shares many characteristics with such distributed systems, its component nodes have much more limited resources and, as the system lacks global synchronization, the computation performed on each node must complete within a fixed time step. We first analyze the performance of the current SpiNNaker neural simulation software and identify several problems that occur when it is used to simulate networks of the type often used to model the cortex which contain large numbers of sparsely connected synapses. We then present a new, more flexible approach for mapping the simulation of such networks to SpiNNaker which solves many of these problems. Finally we analyze the performance of our new approach using both benchmarks, designed to represent cortical connectivity, and larger, functional cortical models. In a benchmark network where neurons receive input from 8000 STDP synapses, our new approach allows 4× more neurons to be simulated on each SpiNNaker core than has been previously possible. We also demonstrate that the largest plastic neural network previously simulated on neuromorphic hardware can be run in real time using our new approach: double the speed that was previously achieved. Additionally this network contains two types of plastic synapse which previously had to be trained separately but, using our new approach, can be trained simultaneously

    Trends in Florida Constitutional Law

    Get PDF

    SPECTRAL DECOMPOSITION OF VERTICAL GROUND REACTION FORCE CURVES

    Get PDF
    INTRODUCTION - The vertical ground re- action force component typically has two peaks. The first peak (impact peak) is caused by the impact between the foot and the ground while the lower frequency second peak (active peak) is caused by the vertical braking of the body followed by vertical push-off. Bobbert et al. (1991) pro- posed a method of decomposing the VGRF into the contribution of the support leg and the rest of the body by double differentiation of segment center of mass position data. This decomposition allowed them to determine the magnitude of the impact peak independent of the rest of the curve. The purpose of this study was to investigate a method of decomposing the VGRF curve that does not require differentiation of position data. METHODOLOGY - Five male recreational runners completed 5 trials in 3 different run- ning shoes that differed only in the density of the midsole material. VGRF data were recorded from a force platform at 1000 Hz using an analogue to digital converter. A Fourier transform was performed on each trial An inverse transform was then per- formed twice - once using the frequencies below 3 Hz and once using the frequencies above 3 Hz. Figure 1 illustrates a typical decomposition of the force curve. Peak (PK) and time to peak (TPK) values were recorded for each curve of the decomposed VGRF curve. RESULTS AND DISCUSSION - The magnitudes and times of the impact and active peaks for the decomposed VGRF are presented in Table 1. The impact peak for the soft shoe had a greater magnitude than the medium or hard shoes. This may indi- cate that this shoe midsole experienced maximum compression or that the subjects perceived the soft midsole and adjusted their kinematics. There were essentially no differences in the active PK between the soft, medium and hard midsoles. Table 1. Mean values for decomposed VGRF variables. Midsole Soft Medium Hard Impact PK 240.1 212.8 238.7 Impact TPK 28.3 26.1 26.6 Active PK 1241.2 1233.4 1244.7 Active TPK 107.9 108.7 104.0 Since the impact peak component is of a higher frequency than the active compo- nent, the decomposed VGRF curves are comparable lo the curves of Bobbert et el. (1991). These results indicate that this pro-cedure can be used to separate the true impact characteristics of the VGRF from the remainder of the curve. REFERENCES Bobbert, M.F. et al. (1991). Calculation of vertical ground reaction force estimates during running from positional data. J Biomech, Vol 24: 12 pp. 1095-1 105
    corecore