Conical Projection Research Articles

Silicon location through backscattered electron imaging and X-ray microanalysis in leaves of Cyperus ligularis L. and Rhynchospora aberrans C. B. Clarke (Cyperaceae)

The Cyperaceae show the ability to incorporate silicon by depositing colloidal silica, which is recorded by the occurrence of projections in the form of cones, in inner tangential walls of some epidermal cells or "silica cells". Leaves of C. ligularis and R. aberrans were analyzed through the technique of electron backscatter. Cyperus ligularis accumulates silica, in addition to "silica cells", in some stomata, trichomes and the cell walls that surround the cavities of the aerenchyma. The silica in the latter occurs in various forms; however, the cells located near the vascular bundles have conical projections, similar to those of the epidermis. Rhynchospora aberrans presents "silica cells" whose projections have tapered "satellites". In this species, silica also occurs in stomata and certain epidermal cells adjacent to them. It appears that the silicon deposition occurs in combination with the wall (with no apparent structural changes), and structures of secretion, or projections of the wall. These structural changes in the species, and location, are probably related to functional and environmental factors, especially the soil, in addition to relation with taxonomic groups.

One new and two known species of Dorylaimoidea (Nematoda) from West Bengal, India

Small populations of Laimydorus istvani sp. n., Laimydorus baldus Baqri & Jana, 1982 and Dorylaimus sp. were collected fromthe soil around the roots of guava at south 24-Parganas district, West Bengal, India. Laimydorus istvani sp. n. is characterizedby its odontostyle being distinctly thicker than the cuticle at the same level, cardia shape: rounded-conoid, wide at pharyngo-intestinal junction, enveloped by intestinal tissue which forms a conical projection extending into the lumen of intestine;delicate ring-like structure between the pharyngeal base and the proper cardia. Laimydorus istvani sp. n. comes close to L.multialaeus (Khera, 1970) Baqri, 1985, L. siddiqii Baqri & Jana, 1982 and L. baldus Baqri & Jana, 1982, but can bedistinguished from these species on the basis of different morphometric measurements. The new species differs from L.multialaeus in having higher a value, lower b value and longer odontostyle in females, and. longer body, lateral guiding piecesand tail in males. From L. siddiqii the new species differs in having a shorter tail in relation to body length, shorter cardia withdifferent shape, shorter prerectum and longer rectum in female, different number of ventromedian supplements and shorterspicules in males. From L. baldus, it differs in having a longer body, greater a-value, longer odontostyle and odontophore andlonger tail in females. Laimydorus istvani sp. n. differs from the males of L. baldus by its longer body, greater c value and in thenumber of ventromedian supplements. The population of L. baldus from West Bengal agrees well with the original descriptionexcept for some variations in body, odontophore, prerectum and tail length. New data on male characters have been provided inthe present study. The specimens of Dorylaimus sp. come close to D. geraerti Baqri & Jana, 1986 except in some morphometricmeasurements including: b (4.2–5.1 vs. 4.3–4.7), odontophore length (33–54 μm vs. 40–43 μm, prerectum length in females(120–160 μm vs. 196–241 μm and tail length in females (247.5–294 μm vs. 249–406 μm). In males, the supplements (36 innumber) occur in a contiguous series (as is usually seen in the genus Dorylaimus Dujardin, 1845), whereas in the typespecimens of D. geraerti 35–38 supplements are largely contiguous except for a set of 4–5 spaced supplements in the middle of the series, showing a resemblance with the genus Ischiodorylaimus Andrássy, 1969.

Microfossils from the Lower Devonian Rhynie Chert with suggested affinities to the peronosporomycetes

A conspicuous silicified microfossil,Frankbaronia polysporan. gen. n. sp., occurs in plant litter and as an inhabitant of microbial mats from the Lower Devonian Rhynie chert, Aberdeenshire, Scotland. Specimens are elongate-cylindrical, oval, or spherical, thin-walled, and may possess conical or column-like surface projections. Most specimens occur isolated, some are arranged in pairs or short chains. Each specimen contains several small spheres, each in turn with a (sub)centric opaque inclusion. Immature specimens indicate that ontogenesis in this fossil includes the formation of a single centric body of opaque material that subsequently is apportioned among the developing small spheres.Frankbaronia polysporais quite similar in size and morphology to the oogonia containing oospores seen in certain extant members of the Peronosporomycetes. The Rhynie chert is known to contain the oldest fossil evidence of the Peronosporomycetes but only a single form (Hassiella monospora) has previously been documented. The discovery of a second putative representative of this group of organisms proves that this paleoecosystem is still an important source of new information on the paleodiversity of microbial life.

The Brazilian Goblin Spiders of the New GenusGuaraguaoonops(Araneae: Oonopidae)

A new endemic goblin spider genus Guaraguaoonops is erected to include two new soft-bodied oonopid species from Brazil: the type species, G. hemhem, distributed in the states of Maranhao, Piaui, and Ceara, and G. humbom, known only from Piaui. These spiders are unique among oonopids and easily diagnosed by the flattened carapace with a porrect clypeus, modified lateral setae on the carapace in both sexes, and male with a sinuous, flattened distal cheliceral projection and palp with ventral conical tegular projection. These species probably occupy a soil cryptic habit and are found in dry sand of “cerrado” areas in northeastern Brazil.

Embryonic development of a whirligig beetle, Dineutus mellyi, with special reference to external morphology (insecta: Coleoptera, Gyrinidae)

The egg morphology and successive changes of developing embryos of the whirligig beetle, Dineutus mellyi (Adephaga: Gyrinidae) are described from observations based on light and scanning electron microscopy. The egg surface is characterized by minute conical projections covering the entire egg surface, a stalk-like micropylar projection at the anterior pole of the egg, and a longitudinal split line along which the chorion is cleaved during the middle embryonic stages. The germ band or embryo is formed on the ventral egg surface, and develops on the surface throughout the egg period; thus, the egg is a superficial type, as is the case in most coleopteran species. A pair of lateral tracheal gills (LTGs) of the first abdominal segment originates from appendage-like projections arising at the lateral side of pleuropodia, and the LTGs of the second to ninth abdominal segments are arranged in a row with that of the first segment. Therefore, LTGs are structures with serial homology. The paired dorsal tracheal gills (DTGs) of the ninth abdominal segment are formed on the regions just latero-dorsal to the LTGs of this segment. Regarding the pleuropodia as the structures being homologous with thoracic legs, neither the LTGs nor DTGs are homologous with thoracic legs, but originate in the more lateral region corresponding to the future pleura of the thoracic segments. The last (10th) abdominal segment in the larva is formed by the fusion of the embryonic 10th and 11th abdominal segments. Four terminal hooks at the end of the last abdominal segment originate from two pairs of swellings on the posterior end of the embryonic 11th abdominal segment. It is proposed that the terminal hooks possibly correspond to the claws of medially fused cerci of the embryonic 11th abdominal segment.

INTERCHANGEABLE BILLIARD CUE TIP ASSEMBLY AND BILLIARD CUE UTILIZING SAME

A billiard cue has a changeable cue tip/ferrule assembly wherein the ferrule has a conical projection fitting snugly into a congruent receptacle in a fixed tenon of the cue. Vibration of the ferrule is limited by being locked to the rigid cue. The configuration is also useful in establishing a concurrent center line of the cue stick and changeable cue tip assembly. The ferrule's cone has a hollow surface whose axis is aligned with the ferrule's longitudinal axis. The invention teaches that the cue, with the ferrule attached, may now be rotated in a lathe with the ferrule's cone's hollow surface mating with a live center in the lathe tailstock. Thus the final tapering and finishing of the cue stick shaft is accomplished in the lathe with the axis of the ferrule's cone defining the cue stick/changeable cue tip mutual centerline.

Giant cutaneous horn on the lower lip

Cutaneous horn is a conical hyperkeratotic projection of the skin composed of compact keratin. A wide range of pathologic conditions may be found at its base, including a significant proportion of malignant tumors. A notable, giant cutaneous horn uncovering a keratoacanthoma/well-differentiated squamous cell carcinoma is presented, highlighting the importance of histopathological examination to rule out malignancy because clinical features cannot assure a correct diagnosis.

GPU-accelerated 3D Bayesian image reconstruction from Compton scattered data

This paper describes the development of fast Bayesian reconstruction methods for Compton cameras using commodity graphics hardware. For fast iterative reconstruction, not only is it important to increase the convergence rate, but also it is equally important to accelerate the computation of time-consuming and repeated operations, such as projection and backprojection. Since the size of the system matrix for a typical Compton camera is intractably large, it is impractical to use a conventional caching scheme that stores the pre-calculated elements of a system matrix and uses them for the calculation of projection and backprojection. In this paper we propose GPU (graphics processing unit)-accelerated methods that can rapidly perform conical projection and backprojection on the fly. Since the conventional ray-based backprojection method is inefficient for parallel computing on GPUs, we develop voxel-based conical backprojection methods using two different approximation schemes. In the first scheme, we approximate the intersecting chord length of the ray passing through a voxel by the perpendicular distance from the center to the ray. In the second scheme, each voxel is regarded as a dimensionless point rather than a cube so that the backprojection can be performed without the need for calculating intersecting chord lengths or their approximations. Our simulation studies show that the GPU-based method dramatically improves the computational speed with only minor loss of accuracy in reconstruction. With the development of high-resolution detectors, the difference in the reconstruction accuracy between the GPU-based method and the CPU-based method will eventually be negligible.

컴프턴 카메라를 위한 재배열 기반 확정론적 영상재구성법

While Compton imaging is recognized as a valuable 3-D technique in nuclear medicine, reconstructing an image from Compton scattered data has been of a difficult problem due to its computational complexity. The most complex and time-consuming computation in Compton camera reconstruction is to perform the conical projection and backprojection operations. To alleviate the computational burden imposed by these operations, we investigate a rebinning method which can convert conical projections into parallel projections. The use of parallel projections allows to directly apply the existing deterministic reconstruction methods, which have been useful for conventional emission tomography, to Compton camera reconstruction. To convert conical projections into parallel projections, a cone surface is sampled with a number of lines. Each line is projected onto an imaginary plane that is mostly perpendicular to the line. The projection data rebinned in each imaginary plane can then be treated as the standard parallel projection data. To validate the rebinning method, we tested with the representative deterministic algorithms, such as the filtered backprojection method and the algebraic reconstruction technique. Our experimental results indicate that the rebinning method can be useful when the direct application of existing deterministic methods is needed for Compton camera reconstruction.

A New Species of the Subgenus Artapocyrtus of the Genus Metapocyrtus (Coleoptera: Curculionidae: Entiminae) from Mindanao, the Philippines

A new Pachyrhynchini species, Metapocyrtus (Artapocyrtus) sakaii sp. nov., is described from Surigao del sur, Mindanao, the Philippines. This species is distinguished from its allied species mainly by having a conical projection on the ventral surface of the rostrum in both sexes.

Put a Brain in Your Camera: Nonstandard Perspectives and Computer Images in the Arts

Ever since the geometry of central perspective (conical projection) was developed in the XV century, it has been observed that mechanical application of the procedure leads to effects of distortion and exaggeration of shapes and sizes, which often make the result look unnatural. Similar observations are made with the optical projections obtained in photography and video. Artists have intuitively corrected these perceptual shortcomings of perspective. In standard perspective, each point of an object or scene is projected upon a plane by means of a bundle of straight projection rays departing from a viewpoint. In the nonstandard perspective that I have developed, I follow a similar procedure, except that I replace the straight projection rays of standard perspective with special curved ones. This model has been validated by visual experiments in the open field. The next step will integrate the nonstandard perspective into a new kind of digital camera which will allow the user to select a preferred perspective by changing an index from i = 0 (conical) up to i = 1 (parallel).

A modern description ofCrambionella stuhlmanni(Scyphozoa: Rhizostomeae) from St Lucia Estuary, South Africa

A new record ofCrambionella stuhlmanniis reported from the east coast of South Africa. The material is described using quantitative morphological data, and mitochondrial (CO1) and nuclear (ITS-1) sequence data. The species can be diagnosed by a combination of morphological features including the presence of conical projections on velar lappets, the absence of orbicular appendages among mouthlets and the short length of the terminal club on the oral arm. Mitochondrial sequence data unambiguously delineateC. stuhlmannias a separate species fromC. orsini, and phylogenetic analyses support its placement within the monophyletic genus,Crambionella.

Cartographic conic projections and their appliance in national cartography

This paper is dedicated to the mapping of conic projections and their appliance in producing maps of our state cartography. So far they were often applied, and will be used precisely coned, polyconed and modified polyconed projections for the official mapping (1:500 000, 1:750 000, 1:1000 000 and 1:1500 000). In particular, they cartographic conical projection at a scale of 1:1000 000 were taken into consideration. Those are the Lambert conformal conical projection with two standard parallels and the Modified polyconic projections. In addition to these cartographic conical projections, is described Boneo`s pseudoconic equivalent projections. This is one of the cartographic conical map projection that is commonly used in the preparation of thematic maps as well as for atlas editions of geographic maps both in Serbia and abroad.

Scattered Radiation Emission Imaging: Principles and Applications

Imaging processes built on the Compton scattering effect have been under continuing investigation since it was first suggested in the 50s. However, despite many innovative contributions, there are still formidable theoretical and technical challenges to overcome. In this paper, we review the state-of-the-art principles of the so-called scattered radiation emission imaging. Basically, it consists of using the cleverly collected scattered radiation from a radiating object to reconstruct its inner structure. Image formation is based on the mathematical concept of compounded conical projection. It entails a Radon transform defined on circular cone surfaces in order to express the scattered radiation flux density on a detecting pixel. We discuss in particular invertible cases of such conical Radon transforms which form a mathematical basis for image reconstruction methods. Numerical simulations performed in two and three space dimensions speak in favor of the viability of this imaging principle and its potential applications in various fields.

Giant Cutaneous Horn in Afro-Brazilian Descendent Patient: Case Report and Literature Review

Cutaneous horn is the clinical diagnosis of hyperproliferation of compact keratin in the epidermis. It is presented as a conical projection of hyperkeratotic skin, often yellowish, which can be straight, curved or twisted and occurs in response to benign or malignant structural changes in the skin. Found most frequently in Caucasian, its giant clinical form is less common, especially in African-descendent patients. We report the case of a giant cutaneous horn in a female, 41 years old, Afro-Brazilian descendent patient, who has arrived at the dermatology ambulatory with a horn-like tumor located in the right parietal scalp with two years of evolution. She underwent to the surgical resection with a safety margin of 0.5cm and partial approximation of the skin flaps to allow healing by secondary intention. Histopathology has shown a completed excised lesion, diagnosed as cutaneous horn, over an area of well-differentiated squamous cell carcinoma. The patient has an uneventful recovery. A review of literature about the issue was undertaken and aspects of its epidemiology, associated disease, biologic behavior and treatment are discussed.

Danionella priapus, a new species of miniature cyprinid fish from West Bengal, India (Teleostei: Cypriniformes: Cyprinidae)

Danionella priapus, a new species of sexually dimorphic miniature cyprinid from the Brahmaputra drainage in India, is distinguished from the other three species in the genus by the presence in adult males of a conical projection of the genital papilla situated between funnel-shaped pelvic fins, the number of analand pectoral-fin rays, and the position of insertion of the last anal-fin pterygiophore. It differs further from D. translucida and D. mirifica in details of the colour pattern, from D. dracula and D. mirifica in number of procurrent caudal-fin rays, from D. translucida in number of vertebrae and from D. dracula in several skeletal characters. Like the other species in the genus, D. priapus shows a developmentally truncated skeleton that is associated with several evolutionary morphological novelties. The present distribution of the Danionella species may be the result of a vicariance event in the early Miocene, when the tectonic uplift of eastern Tibet and the Indo-Burman ranges lead to the interruption of the palaeo-connection between the Tsangpo (Brahmaputra) and the upper Irrawaddy Rivers.

A Chernobyl 137Cs contamination study as an example for the spatial structure of geochemical fields and modeling of the geochemical field structure

A proposal is presented to treat the spatial distribution of chemical elements as a continuous numerical field with a specified structure where each value depends upon the others reflecting the deterministic character of the field. 137Cs contamination stemming from the Chernobyl accident has been studied to demonstrate the regular spatial structure of the geochemical field. It is shown to consist of a system of polycentric anomalies of initial and secondary origin that can be followed on different spatial levels. A regular spatial structure is shown to be reflected in the shape of a frequency histogram. Mathematical modeling of mono- and poly-centric geochemical anomalies, with the help of a digital conical projection and production of frequency histograms, are used to demonstrate the non-random character of geochemical data and the potential for further development of a non-stochastical approach in the study and prediction of spatial structures for geochemical fields that can be based on the theory of mathematical field and its numerical modeling.

On a Novel Approach to Compton Scattered Emission Imaging

Imaging processes built on the Compton scattering effect are currently under intense investigation. However, despite many innovative contributions, this topic still pose a formidable mathematical and technical challenge. In this work, we argue that, in the framework of single-photon emission imaging, collecting Compton scattered radiation from an emitting object, allows to image the radiotracer distribution in vivo. Data is acquired by a stationary collimated gamma camera under the form of compounded conical projections of the activity density function. Mathematically, the image formation process is described by the so-called compounded conical radon transform (CCRT) and three-dimensional object reconstruction is based on an inversion formula of the CCRT. We perform numerical simulations to show the feasibility of this new imaging modality, which offers the remarkable advantage of operating in stationary mode without the need of bulky and cumbersome spatial rotational mechanism of conventional gamma cameras. This is highly attractive for applications in medical imaging, industrial non-destructive evaluation, nuclear waste storage surveillance and homeland security monitoring. Finally, to improve drastically the sensitivity, we introduce a new feature allowing to acquire data without mechanical collimation and support the findings with some preliminary simulation results.

Ultrastructure of spermatogenesis of Taenia taeniaeformis (Batsch, 1786) (Cestoda, Cyclophyllidea, Taeniidae) and comparison of spermatological characters in the family Taeniidae Ludwig, 1886

AbstractThe ultrastructure of spermatogenesis of Taenia taeniaeformis is described for the first time by means of transmission electron microscopy (TEM). Mature testes contain all stages of spermatogenesis; primary spermatogonia are usually situated at the periphery and mature spermatozoa in the centre of testes. The general process is similar to that described in other cestodes. Six incomplete, synchronic cytokineses occur: four mitotic and two meiotic cell divisions. All these divisions occur simultaneously, resulting in a rosette cluster of four tertiary spermatogonia, then eight quaternary spermatogonia, and subsequently sixteen primary spermatocytes. All of these enter into a growth period and their enlarged nuclei move to the periphery of cells of the rosettes. The first meiotic division forms thirty-two secondary spermatocytes and after the second meiotic division, there are sixty-four spermatids. Spermiogenesis in T. taeniaeformis corresponds to the Ba and Marchand’s Type 3 and begins with the formation of a differentiation zone in the form of a conical projection of cytoplasm delimited by a ring of arching membranes and surrounded by submembranous cortical microtubules. Within this area, there are two centrioles, orthogonally disposed, and vestigial striated rootlets. Only one of the centrioles develops a flagellum that grows externally to the cytoplasmic extension. Posteriorly, a flagellar rotation inferior to 90° occurs and the flagellum becomes parallel to the cytoplasmic extension. Later, the two processes fuse during the so-called proximodistal fusion. The nucleus elongates and moves into the cytoplasmic extension. In the final stage of spermiogenesis, a single crested body appears at the base of the differentiating spermatozoon. Finally, the ring of arching membranes constricts and the young spermatozoon detaches from the residual cytoplasm. Ultrastructural aspects of spermatogenesis are compared with that of other cestodes studied to date, particularly of the family Taeniidae.

Room-temperature synthesis and characterisation of ion-induced iron-carbon nanocomposite fibres

Graphite plates were Ar+ ion-irradiated with and without a simultaneous Fe supply at room temperature. The surfaces ion-irradiated without an Fe supply were covered with densely distributed conical projections with a carbon nanofibre (CNF) on the top. The CNFs thus grown were 20-50 nm in diameter and 0.3-2 µm in length. By contrast, the graphite surfaces ion-bombarded with a simultaneous Fe supply were characterised by various kinds of carbon composites, such as conical protrusions with and without a single carbon nanocomposite fibre (CNCF) on the top, depending on the Fe supply rates. As confirmed by transmission electron microscope (TEM), the CNCFs thus grown were amorphous-like and possessed no hollow structure. Energy dispersive X-ray analysis disclosed that CNCFs consisted of carbon and iron, and quite fine Fe crystallites were dispersed over the CNCF. Since various metals can be incorporated into the room-temperature grown carbon nanofibres, this ion-irradiation method is believed to be promising as a new approach to synthesise one-dimensional (1-D) nanomaterials at low temperatures.