Rows Of Plates Research Articles

Redescription of Chabaudacuaria multispinosa (Pérez Vigueras, 1938) n. g., n. comb. (Nematoda: Spirurida: Acuariidae) based on specimens from Ardea herodias L. and Nyctanassa violacea (L.) (Ardeidae) in Florida

Chabaudacuaria n. g. is erected, as monotypic, for C. multispinosa (Pérez Vigueras, 1938) n. comb. (Spirurida: Acuariidae) [syns Cheilospirura multispinosa Pérez Vigueras, 1938; Acuaria multispinosa (Pérez Vigueras, 1938) Yamaguti, 1961]. This species, a parasite of various ardeid birds, is redescribed by means of light and scanning electron microscopy based on material from great blue herons Ardea herodias L. and yellow-crowned night herons Nyctanassa violacea (L.) in Florida, USA. Chabaudacuaria n. g. resembles Acuaria Bremser, 1811, Cheilospirura Diesing, 1861, Skrjabinocerca Schikhobalova, 1930 and Xenocordon Mawson, 1982 in its straight cordons which do not anastomose. However, it can be distinguished from them by the didelphic-prodelphic uterus and the absence of caudal alae in the males. In the pattern of its cordons (consisting of a row of plates and a longitudinal ridge) and the absence of an area rugosa, the new genus is similar to Chevreuxia Seurat, 1918, Syncuaria Gil'bert, 1927, Aviculariella Wehr, 1931, Skrjabinocara Kurashvili, 1940, Decorataria Sobolev, 1949 and Desportesius Chabaud & Campana, 1949, which are characterised by anastomosing cordons. The didelphic-prodelphic female reproductive system of Chabaudacuaria is intermediate between the didelphic-amphidelphic uterus of Chevreuxia and the monodelphic-prodelphic uterus of Syncuaria, Aviculariella, Skrjabinocara, Desportesius and Decorataria. Therefore, the straight and non-anastomosing cordons are considered to be autapomorphic for Chabaudacuaria.

Regeneration of ciliary comb plates in the ctenophore Mnemiopsis leidyi. i. morphology

Regeneration of missing body parts in model organisms provides information on the mechanisms underlying the regeneration process. The aim here is to use ctenophores to investigate regeneration of their giant ciliary swimming plates. When part of a row of comb plates on Mnemiopsis is excised, the wound closes and heals, greatly increasing the distance between comb plates near the former cut edges. Video differential interference contrast (DIC) microscopy of the regeneration of new comb plates between widely separated plates shows localized widenings of the interplate ciliated groove (ICG) first, followed by growth of two opposing groups of comb plate cilia on either side. The split parts of a new plate elongate as their bases extend laterally away from the ICG widening and continue ciliogenesis at both ends. The split parts of a new plate grow longer and move closer together into the ICG widening until they merge into a single plate that interrupts the ICG in a normal manner. Video DIC snapshots of dissected gap preparations 1.5-3-day postoperation show that ICG widenings and/or new plates do not all appear at the same time or with uniform spacing within a gap: the lengths and distances between young plates in a gap are quite variable. Video stereo microscopy of intact animals 3-4 days after the operation show that all the new plates that will form in a gap are present, fairly evenly spaced and similar in length, but smaller and closer together than normal. Normal development of comb plates in embryos and growing animals is compared to the pattern of comb plate regeneration in adults. Comb plate regeneration differs in the cydippid Pleurobrachia that lacks ICGs and has a firmer mesoglea than Mnemiopsis. This study provides a morphological foundation for histological, cellular, and molecular analysis of ciliary regeneration in ctenophores.

BioSpotlight

BioTechniquesVol. 50, No. 3 BioSpotlightOpen AccessBioSpotlightPatrick C.H. Lo & Kristie NyboPatrick C.H. LoSearch for more papers by this author & Kristie NyboSearch for more papers by this authorPublished Online:3 Apr 2018https://doi.org/10.2144/000113620AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinkedInReddit Diving BAC into the Pool with MicroarraysSecond-generation sequencing with its short read lengths is not practicable when determining whole-genome sequences from species possessing large genomes with a high content of repetitive DNA. Realistically, reference sequences for these species can only be obtained using physical map–based sequencing of BAC clones. A key step to this genome sequencing methodology is the ordering and orientation of BAC clones through their anchoring to a genetic map. This approach typically requires screening BAC libraries for clones with specific gene sequences using DNA hybridization or PCR, rendering it low-throughput and labor-intensive. In this issue, P. Hedley and colleagues at the Scottish Crop Research Institute (Dundee, Scotland) describe a new strategy for the high-throughput addressing of thousands of genes to thousands of BACs in parallel using a novel application of DNA microarray technology developed for the unsequenced 5.3-Gb genome of barley. Whole genome–amplified DNA derived from multidimensional pools of barley BAC clones was screened on a custom microarray of 42,000 expressed barley genes. The BACs were pooled using a previously developed “matrix” pooling strategy whereby the location of a clone along a particular dimension (plate, row, or column of 384-well plates) of a Super Pool (SP) of seven 384-well plates could be determined by the presence of positive signals in two separate matrix pools in that dimension. As a proof of principle, the authors tested 2 SPs out of the 55 SPs from a barley BAC library with ~148,000 clones. All matrix pools from the first SP were labeled with Cy3 while those of the second SP were labeled with Cy5. Pairs of labeled matrix pools, one from each SP, were then cohybridized to a microarray. Signals extracted from the scanned images of the hybridized microarrays were analyzed using customized scripts to first identify those probes with a high signal in only two matrix pools in a particular dimension, and then to combine the information from all three dimensions for deconvolution and identification of specific BAC clones containing the microarray probe sequence. This cost-effective, high-throughput, and accurate method for anchoring BACs should be applicable to any species where a whole-genome sequence is lacking.(See “Highly parallel gene-to-BAC addressing using microarrays”)Magnetic AttractionDiscovering the molecular mechanisms governing the differentiation of neural stem cells (NSCs) is essential before these cells can be used to develop therapies for neurodegenerative diseases. For those researchers wishing study specific genes that could induce or suppress differentiation of NSCs, an obstacle has been the difficulty in transfecting NSCs using conventional methods. Nucleofection and lipofection are commonly used for delivering genes to cells, but when applied to NSCs, they exhibit extensive toxicity soon after transfection and may interfere with studies of differentiation. While nucleofection does result in a reasonable percentage of transfected cells, it is costly and most cells die during electroporation. Writing in this issue of BioTechniques, Sapet et al. from OZ Biosciences (Marseille, France) along with colleagues from the National Center for Scientific Research in Paris demonstrate that magnetofection is a viable alternative method for efficiently delivering DNA to NSCs that minimizes undesired toxic effects and does not appear to affect differentiation. Magnetofection is accomplished by associating nucleic acid vectors carrying the desired sequences with super-paramagnetic nanoparticles, which are added to a cell culture. When a magnetic field is then applied to the culture particles rapidly accumulate around the cells, leading to uptake of the DNA. The authors present an optimized protocol for transfecting NSCs using magnetofection, and show that the magnetofection method can be used to identify genes involved in the neuronal differentiation of NSCs. Because of the simplicity, low cost, reduced toxicity, and reliability of this method, the approach has the potential to be valuable for both small scale and high throughput projects seeking to identify new regulators of neuronal differentiation facilitating understanding of the differentiation of these cells and adding further insight into their potential for therapeutic development.Neural stem cell differentiation.Images of neural stem cells acquired 4 days after NeuroMag transfection of a mix between a GFP vector together with either an empty vector (A) or a NeuroD1 expressing vector (B).(See “High transfection efficiency of neural stem cells with magnetofection”)FiguresReferencesRelatedDetails Vol. 50, No. 3 Follow us on social media for the latest updates Metrics History Published online 3 April 2018 Published in print March 2011 Information© 2011 Author(s)PDF download

A new normalizing algorithm for BAC CGH arrays with quality control metrics.

The main focus in pin-tip (or print-tip) microarray analysis is determining which probes, genes, or oligonucleotides are differentially expressed. Specifically in array comparative genomic hybridization (aCGH) experiments, researchers search for chromosomal imbalances in the genome. To model this data, scientists apply statistical methods to the structure of the experiment and assume that the data consist of the signal plus random noise. In this paper we propose “SmoothArray”, a new method to preprocess comparative genomic hybridization (CGH) bacterial artificial chromosome (BAC) arrays and we show the effects on a cancer dataset. As part of our R software package “aCGHplus,” this freely available algorithm removes the variation due to the intensity effects, pin/print-tip, the spatial location on the microarray chip, and the relative location from the well plate. removal of this variation improves the downstream analysis and subsequent inferences made on the data. Further, we present measures to evaluate the quality of the dataset according to the arrayer pins, 384-well plates, plate rows, and plate columns. We compare our method against competing methods using several metrics to measure the biological signal. With this novel normalization algorithm and quality control measures, the user can improve their inferences on datasets and pinpoint problems that may arise in their BAC aCGH technology.

Peristedium indicum Brauer 1906, a junior synonym of Paraheminodus murrayi (Günther 1880) (Teleostei: Peristediidae)

Peristedium indicum Brauer 1906 (family Peristediidae) has not been reported since its original description. Reexamination of syntypes of P. indicum revealed that P. indicum is included in the genus Paraheminodus Kamohara 1957 because of having upper jaw teeth, a smooth lateral margin, posterior parts of lower lateral rows of bony plates separated from each other, and all lower jaw barbels unbranched except for the posteriormost barbels. Based on a comparison of syntypes of P. indicum with all types and other materials of all congeners of Paraheminodus, it is concluded that P. indicum is a junior synonym of Paraheminodus murrayi (Günther 1880).

A new species of suckermouth armored catfish, Pseudancistrus kwinti (Siluriformes: Loricariidae) from the Coppename River drainage, Central Suriname Nature Reserve, Suriname

A new species of suckermouth armored catfish, Pseudancistrus kwinti, is described from the Coppename River, Suriname. It can be diagnosed from all other described Pseudancistrus by the following combination of characters: dentary papillae absent, mid-dorsal plate row complete, coloration mottled or with bars, hypertrophied odontodes along edge of snout, and weakly evertible cheek plates. It is only known from the Coppename River drainage within the Central Suriname Nature Reserve, a United Nations World Heritage Site, and one of the most pristine environments remaining on the planet. Mining, increased fishing pressure, and tourism threaten to change the region.

Redescription of Desportesius brevicaudatus (Spirurida, Acuariidae) based on nematodes from Ixobrychus minutus (Aves, Ciconiiformes) from Bulgaria

Abstract Desportesius brevicaudatus (Dujardin, 1845) is redescribed on the basis of light-microscopy and SEM observations on specimens collected from the oesophagus and under the lining of the gizzard of Ixobrychus minutus (Ardeidae) from Bulgaria. New metrical data expand the known ranges of variation of the measurements of the body, tail, cordons, oesophagus and spicules. New information is provided on the variation of the shape of the deirids, the structure of the vagina, the complexity of the cordons, the pattern of the cuticular striation and the shape of the postdeirids. Cordons are described as consisting of a single row of serrate cuticular plates and a longitudinal cuticular ridge along the outer rims of the cuticular plates. The cuticular ridge is interpreted as homologous to the outer row of plates in the cordons of the genera Acuaria, Cheilospirura and Echinuria.

New Record of Palaeoscolecids from the Early Cambrian of Yunnan, China

Abstract:A new palaeoscolecid,Guanduscolex minorHu, Luo et Fu gen. et sp. nov., with preserved soft parts of introvert and intestines comes from the Lower Cambrian Guanshan fauna of Yunnan, South China. Microstructural details of the cuticle revealed by scanning electron microscopy (SEM) show that each annulation bears three rows of plates and each plate bears 9–10 marginal and 4–5 central nodes. This discovery sheds new light on the relationships and evolutionary pathway of the palaeoscolecids and other early priapulids.

Isolation between sympatric anadromous and resident threespine stickleback species in Mud Lake, Alaska

A sympatric pair of anadromous and resident freshwater threespine stickleback species (Gasterosteus aculeatus species complex) occurs in Mud Lake in the Matanuska-Susitna Valley, Alaska. The two forms differ in an array of morphological traits, including traits associated with predator defense (e.g., spine lengths) and trophic ecology (e.g., number of gill rakers). Mud Lake is only the third lake reported to have anadromous stickleback (which have a complete row of lateral plates) coexisting with low-plated resident stickleback in the absence of intermediate partially plated fish. Microhabitat and seasonal isolation appear to contribute to reproductive isolation between the two forms.

The green sturgeon and its environment: introduction

The green sturgeon, Acipenser medirostris, is one of two acipenserid fishes native to the temperate waters of the Pacific coast of North America. Originally, three species of sturgeon were described from this region, and this one named ‘‘medirostris’’ or ‘‘middle snout’’ based on the length of its rostrum relative to the other purported species (Ayers 1854), both of which were later determined to be white sturgeon, Acipenser transmontanus (Moyle 2002). The green sturgeon is similar in appearance to the congeneric white sturgeon, with which it cooccurs, except that its barbels are usually closer to the mouth than to the tip of the snout. Green sturgeon are heavily armored, possessing one dorsal, two lateral and two bottom rows of scutes or bony plates (Moyle 2002). In addition, there are often one or two large scutes behind the dorsal fin, as well as one behind the anal fin, which are both lacking in the white sturgeon. The common name of the species is apt due its distinctly olive-green body color, with olivaceous stripes usually present on its sides and ventral surface. Green sturgeon are currently thought to be comprised of two genetically distinct breeding populations (Israel et al. 2004): a northern distinct population segment (DPS) consisting of fish that spawn in the Rogue River, Oregon (Erickson et al. 2002), and the Klamath River, California (Van Eenennaam et al. 2001), and a southern DPS that spawns in the Sacramento River, California. Increasingly, many fish species are being recognized as consisting of multiple, genetically distinct stocks. In many cases, these stocks are managed separately because of distinctive phenotypic, physiological, and behavioral characteristics representative of the unique adaptations each stock has to the environmental conditions in a particular habitat (Waples 1995). Although little is known about what distinguishes these green sturgeon populations biologically, several unique physical characteristics differentiate the river systems in which they occur. Tidal flows in an expansive estuary, voluminous flows, long river length, and multiple tributaries in an extensive watershed distinguish the Sacramento River from the Rogue and Klamath Rivers with their small estuaries, relatively short length, and smaller watersheds. Based on the best information available to the National Marine Fisheries Service (Adams et al. in press), the southern DPS was A. P. Klimley (&) P. J. Allen J. T. Kelly Department of Wildlife, Fish & Conservation Biology, University of California, One Shields Avenue, Davis, CA 95616, USA e-mail: apklimley@ucdavis.edu

Limiting pressure on rows of strip plates and the “no-force-through” effect

The problem of the theory of limiting equilibrium relative to the pressure of an infinite periodic series of strip plates on a weightless cohesive bed is examined. The “no-force-through” effect is exposed when the distances between plates are less then a certain critical value. A formula for determination of the limiting pressure and critical gap is proposed as a result of the processing of numerical calculations. Applications of this problem to actual geomechanical problems such as anti-slide pile bracings are discussed.

Lopholeucaspis japonica

<i>Lopholeucaspis japonica</i>

Control of Wave Propagation in Sandwich Plate Rows with Periodic Honeycomb Core

The wave propagation in sandwich plate rows with cellular core is analyzed and controlled. Honeycomb core materials of different geometry placed periodically along the structure introduce the proper impedance mismatch necessary to obstruct the propagation of waves over specified frequency bands ~stop bands!. The location and the extension of the stop bands can be optimized by proper selection of the geometrical and physical properties of the core. An optimal configuration of the core can be identified to design passive sandwich structures, which are stable and quiet over desired frequency bands. A theoretical model is developed to describe the wave propagation characteristics and the vibrations of a three-layered sandwich plate simply supported along its longitudinal edges. The core properties of the plate change periodically along the plate length. The wave propagation characteristics are estimated by analyzing the transfer matrix of each cell of the resulting periodic structure. The transfer matrix is also properly recast to obtain the cell's dynamic stiffness matrix and to formulate a spectral finite element model for the periodic sandwich plate. The spectral finite element model allows predicting the dynamic behavior of the structure with a significantly reduced number of elements as compared to conventional finite elements. The numerical model is used to predict the dynamic response of the considered class of plates and to study their propagation and attenuation characteristics for various core configurations. The presented numerical results demonstrate the simplicity and the effective- ness of the proposed treatment, which reduces the transmission of waves and the plate vibrations over specified frequency bands without the need of additional passive or active control devices. Such unique characteristics can be employed to design lightweight composite panels behaving as mechanical filters. The filtering capabilities of such passive composite panels can be properly modified and optimized to fit required transmissibility levels over desired frequencies without compromising the size and the weight of the structure.

Novel bridge of axon-like processes of epithelial cells in the aboral sense organ of ctenophores.

We describe by light and electron microscopy a novel structure in the aboral sense organ (apical organ) of cydippid (Pleurobrachia) and lobate (Mnemiopsis) ctenophores. An elevated bundle of long, thin, microtubule-filled processes arises from the apical ends of two groups of epithelial cells located on opposite sides of the apical organ along the tentacular plane of the body. This bundle of axon-like processes arches over the epithelial floor like a bridge, with branches at both ends running toward opposing pairs of ciliary balancers that are motile pacemakers for the rows of locomotory ciliary comb plates. The bridge in Pleurobrachia is approximately 40 microm long and 3-4 microm wide and consists of approximately 60 closely packed processes, 0.2-0.8 microm thick, containing vesicles and numerous microtubules running parallel to their long axes. There are approximately 30 epithelial cells in each of the two groups giving rise to the bridge and each cell forms a single process, so roughly half of the processes in the bridge must originate from cells on one side and diverge into branches to a pair of balancers on the opposite side of the apical organ. The 150-200 cilia in each balancer arise from morphologically complex cellular projections with asymmetric lateral extensions directed towards a fork of the bridge. Presynaptic triad structures and vesicles are found in this region but clear examples of synaptic contacts between bridge processes and balancer cells have not yet been traced. Cydippid larvae of Mnemiopsis have a conspicuous bridge along the tentacular plane of the apical organ. Beroid ctenophores that lack tentacles at all stages do not have a bridge. We discuss the possibility that the bridge is an electrical conduction pathway to balancers that coordinates tentacle-evoked swimming responses of ctenophores, such as global ciliary excitation.

The hinged back plate mechanism in glassy wax tests of New Zealand male soft scale insects (Hemiptera: Coccoidea: Coccidae)

Male scale insects (Hemiptera: Coccoidea) undergo a metamorphosis of the neometabola type, from scale-like nymph through prepupa and pupa to winged adult. The nymphal instar before prepupa secretes a waxy protective covering that remains in place throughout metamorphosis and these covers are characteristic of each family of scale insects. Most scale insect families (e.g. mealybugs, eriococcids, diaspidids) have rather loosely woven male covers, but male nymphs in the family Coccidae (soft scales) construct more rigid, glassy wax tests, which need a special mechanism for adult emergence. In the New Zealand male soft scales, a suture across the posterior quarter of the test enables the back plate to flex at a pair of hinges, to be raised up off the substrate, and so allow egress. The waxy back plate hinges are secreted by groups of tubular ducts on the abdominal dorsum of 2nd-instar males, during construction of the test. Scanning electron micrographs (SEMs) show the detail and diversity of hinge types. The wax tests of most New Zealand Coccidae, both female and male, are apparently unique in that they are constructed in rows of hexagonal plates, separated by sutures, however in the male test, the sutures are all fused except for the back plate suture. The two species in the endemic New Zealand genus Pounamococcus have male tests more like those of species in the Australian genus Austrolecanium.

A214 垂直加熱平板列まわりの自然対流の流動と伝熱(オーガナイズドセッション4 : 自然対流)

Natural convective flow and heat transfer around a row of vertical heated plates were investigated both analytically and experimentally. Main concerns are directed to an effect of plate numbers on the fluid flow and heat transfer around the plate arrays. In order to simulate the flow and temperature fields around the rows of plates, full elliptic equations for the momentum and energy transport were solved numerically using the computational domain that encloses the whole plates. The results showed that the present elliptic analysis well predicts the plume interaction and also the local heat transfer coefficients of the plates. The results also depict that the velocity profiles and induced flow rates in between the pairs of plates depend strongly on the numbers and situations of the plates. This also results in marked differences in the local heat transfer coefficients of the plates.

Two-channel X-ray reflectometer

The two-channel X-ray reflectometer is proposed providing an increase in accuracy and sensitivity especially to nanoscale oxide layers. The reflectometer has two independent measuring channels controlled by a processor and the beam-splitting and spectral selection device based on a row of semitransparent plates of pyrolitic graphite. Results of reflection curve measurements in a relative mode are presented for an Ni film and GaAs monocrystal.

G303 一様流中の平行な薄板列から発生する空力共鳴音

G303 一様流中の平行な薄板列から発生する空力共鳴音

Argentophilic structures of the miracidium of Echinochasmus perfoliatus (Trematoda: Echinostomatidae).

Argentophilic structures of the miracidium of Echinochasmus perfoliatus were described from material collected in the vicinity of Vladivostok, Far East of Russia. Impregnated with 0.5% solution of AgNO3 miracidium showed 21 epidermal plates arranged in four rows: 6 + 9 + 4 + 2. Up to 23 papilla-like structures on the terebratorium were arranged along three axes and in four groups. A single papilla was located at the base of each of ventral and dorsal epidermal plates of the first row. Two papillae were located at the base of each of lateral epidermal plates of the first row. The eyespots were located posterior to the first row of plates. Two excretory pores were located anterior to the last row of plates. The results obtained were compared with the argentophilic structures of closely related species of the genus Echinochasmus.

VIBRATIONAL ENERGY FLOWS BETWEEN PLATES WITH COMPLIANT AND DISSIPATIVE COUPLINGS

In this work, the transmission of energy through a compliant and dissipative joint between two thin rectangular plates is investigated using a receptance approach. Exact formulae for the spectral density of the energy flow through the joint, the energy dissipated at the joint, the power input by the external excitation and the vibrational energies of the two plates are established when the plates are subject to random ergodic forcing. The more general case of a row of plates which are simply supported along the two longitudinal edges and coupled through compliant and dissipative joints is also investigated. The aim of this study is to examine the effect of joint damping and compliance on the magnitudes of energy flows through the joints and energy levels of the plates. Interest is focused on the energy dissipation at the joints and the conditions for which it is maximised.