Oval Section Research Articles

NONUNIFORM PROCESSES OF CHROMOSOME EVOLUTION IN SEDGES (CAREX: CYPERACEAE)

Holocentric chromosomes-chromosomes that lack localized centromeres-occur in numerous unrelated clades of insects, flatworms, and angiosperms. Chromosome number changes in such organisms often result from fission and fusion events rather than polyploidy. In this study, I test the hypothesis that chromosome number evolves according to a uniform process in Carex section Ovales (Cyperaceae), the largest New World section of an angiosperm genus renowned for its chromosomal variability and species richness. I evaluate alternative models of chromosome evolution that allow for shifts in both stochastic and deterministic evolutionary processes and that quantify the rate of evolution and heritability/phylogenetic dependence of chromosome number. Estimates of Ornstein-Uhlenbeck model parameters and tree-scaling parameters in a generalized least squares framework demonstrate that (1) chromosome numbers evolve rapidly toward clade-specific stationary distributions that cannot be explained by constant variance (Brownian motion) evolutionary models, (2) chromosome evolution in the section is rapid and exhibits little phylogenetic inertia, and (3) explaining the phylogenetic pattern of chromosome numbers in the section entails inferring a shift in evolutionary dynamics at the root of a derived clade. The finding that chromosome evolution is not a uniform process in sedges provides a novel example of karyotypic orthoselection in an organism with holocentric chromosomes.

A Bayesian Model of AFLP Marker Evolution and Phylogenetic Inference

Amplified Fragment Length Polymorphism (AFLP) markers are formed by selective amplification of DNA fragments from digested total genomic DNA. The technique is popular because it is a relatively inexpensive way to produce large numbers of reproducible genetic markers. In this paper, we describe a Bayesian approach to modeling AFLP marker evolution by nucleotide substitution and an MCMC approach to estimate phylogeny from AFLP marker data. We demonstrate the method on species in Carex section Ovales, a group of sedges common in North America. We compare the results of our analysis with a clustering method based on Nei and Li's restriction-site distance and a two-state Bayesian analysis using MrBayes.

Woolly Hair Nevus Associated With an Ipsilateral Linear Epidermal Nevus

We report a 4-year-old boy with two areas of woolly hair in the right parietotemporal region and a linear epidermal nevus in the areas of woolly hair as well as in the ipsilateral hemiface and chin. Evaluation by scanning electron microscopy showed woolly hair with oval transverse section and longitudinal groove. A complete examination ruled out associated anomalies.

Chromosome Number Changes Associated with Speciation in Sedges: a Phylogenetic Study in Carex section Ovales (Cyperaceae) Using AFLP Data

Phylogenetic analysis of amplified fragment length polymorphisms (AFLP) was used to infer patterns of morphologic and chromosomal evolution in an eastern North American group of sedges (ENA clade I of Carex sect. Ovales). Distance analyses of AFLP data recover a tree that is topologically congruent with previous phylogenetic estimates based on nuclear ribosomal DNA (nrDNA) sequences and provide support for four species groups within ENA clade I. A maximum likelihood method designed for analysis of restriction site data is used to evaluate the strength of support for alternative topologies. While there is little support for the precise placement of the root, the likelihood of topologies in which any of the four clades identified within the ENA clade I is forced to be paraphyletic is much lower than the likelihood of the optimal tree. Chromosome counts for a sampling of species from throughout sect. Ovales are mapped onto the tree, as well as counts for all species in ENA clade I. Parsimony reconstruction of ancestral character states suggest that: (1) Heilborn’s hypothesis that more highly derived species in Carex have higher chromosome counts does not apply within sect. Ovales, (2) the migration to eastern North America involved a decrease in average chromosome count within sect. Ovales, and (3) intermediate chromosome counts are ancestral within ENA clade I. A more precise understanding of chromosomal evolution in Carex should be possible using likelihood analyses that take into account the intraspecific polymorphism and wide range of chromosome counts that characterize the genus.

Phylogeny and Classification ofCarexSectionOvales(Cyperaceae)

Section Ovales is the most species‐rich section of the sedge genus Carex in the New World. Phylogenetic analyses of molecular data recover a predominantly New World clade as sister to a solitary east Asian species, C. maackii. Nuclear ribosomal DNA are congruent in the placement of all taxa within the section, with a solitary exception: incongruence between ITS and ETS data in the placement of C. bonplandii and C. roraimensis suggests a hybrid origin for this lineage. Biogeography correlates strongly with phylogeny in the section, but there have been at least two instances of long‐range dispersal, one from an eastern North American clade to western North America and one from the New World to Eurasia. Morphological characters studied are all homoplastic. Developing a comprehensive infrasectional classification with a phylogenetic basis would be complicated by the fact that most of the novel morphological characters in the section have evolved within relatively small, independent clades.

The Treatment of Acne Scarring Using a Wire Scalpel

Introduction: Treatment of acne scarring is a staged and time-consuming procedure. Needle subcision is used to raise rolling scars that are attached below the level of the dermis. This article describes a modification of that technique to treat a “field” of acne scars with a commercially available wire scalpel. This technique treats rolling scars and has some benefit to clusters of deep boxcar scars. A patient example is demonstrated. Materials and Methods: After local infiltration with 1% lidocaine with 1:100 000 epinephrine in a volume sufficient to blanch the operative sites, the areas are divided into narrow triangular or oval sections approximately 5 mm at the widest point. A straight needle swedged on a wire scalpel is used to guide the wire from the apex through the 3 sides of the triangle and back out the apex. The desired level is just subdermal. The needle should exit and re-enter through the same hole at the 3 corners. The wire is then grasped firmly and pulled beneath the dermis with a sawlike motion, allowing the wire to severe the dermal attachments. This process is repeated in slightly overlapping sections to avoid depressions from untreated areas until every identified scar is treated. Patient Presentation: In the case presented, some acne scarring remained visible; however, the authors noted an overall improvement, and the patient stated he was pleased with the results. Bleeding is usually minimal, and pressure dressings are normally not necessary. Discussion: The technique of wire subcision is an extension of a proven technique of needle subcision in the treatment of acne scarring. Although it is not useful in the treatment of all types of acne scarring, it is very effective when treating rolling scars that have dermal attachments. Each pass of the wire treats a wider area than the needle technique and is therefore better designed to completely undermine an area with fewer dermal attachments left untreated. Lacerations can be avoided by carefully exiting and entering through the same needle holes. Conclusions: The wire subcision technique treats rolling scars and may benefit clusters of deep boxcar scars. It may also be used to treat wider areas than needle subcision. The technique is simple and the complication rates are low. The authors believe this is a useful addition to the pantheon of acne scarring treatment techniques.

Un nouveau gisement du Paléolithique supérieur récent : le Petit Cloup Barrat (Cabrerets, Lot, France)

Abstract Located on the same hillside as Pech Merle, 800 metres from the entrance of that famous decorated cave, the site of Petit Cloup Barrat opens onto the edge of a small doline. Though partially excavated at the beginning of the 20th century, this site has never been published. A test pit in 2003 was followed by excavations at the entrance of the cave in 2004 and 2005. The stratigraphic sequence, whose base is still unknown, yielded abundant lithic and organic remains attributed to the Middle Magdalenian, Badegoulian and Solutrean. In the upper ensemble, attributed to the Middle Magdalenian, numerous flint blade tools (scrapers, burins, borers and retouched blades) coexist with backed bladelets. The Badegoulian is identified based on flake tools, including raclettes and transverse burins on notches. The Solutrean, still little excavated, is characterized by fragmented shouldered points and one fragment of a Willow Leaf Point. The bone industry includes eyed needles, matrices on fox tibias and retouchers on medium-sized ungulate diaphyses. The antler projectile points are highly variable (with or without groove, double or median bevel, round or oval section). A fragment of a barbed element and a fragment of a bâton percé complete the inventory. Sawed and/ or pierced shells, principally dentalia, and herbivore incisors (reindeer, ibex) were used to make personal ornaments. A few fossils, some with distant origins, were also discovered. Archaeozoological analysis shows the marked presence of reindeer, followed by horse. Red deer and fox are attested by a few remains. The osseous material preserved in the cave permits precise observation of hunting seasons, butchery traces and modes of combustion. The site of Petit Cloup Barrat is localized within an ensemble of Upper Palaeolithic sites around the confluence of the Lot and Célé Rivers, including Cuzoul de Vers and Les Peyrugues. The study of this plateau site is thus integrated in a context of palaeoethnographic hypotheses that have already been partially proposed. The analysis of the material and integration of the results will contribute to a characterization of the subsistence economy in a still little-known natural environment and clarify its relationship with the sites that constitute its environment on different scales. The proximity of Pech Merle Cave and the possibility of establishing links between a dwelling site and a decorated cave constitute an additional motivation for our research.

Phylogenetic relationships in Carex , subgenus Vignea (Cyperaceae), based on ITS sequences

To evaluate the sectional classification in Carex, subgenus Vignea, the ITS region of 58 species of 20 sections was analyzed with Neighbor Joining (NJ) and Markov chain Monte Carlo (MCMC) methods. Sections Dioicae, Physodeae and Ovales are found to be monophyletic, with C. bohemica well integrated in the section Ovales. Section Heleonastes turns out to be monophyletic, if C. canescens is treated separately in section Canescentes. Section Elongatae is monophyletic, but C. remota is placed in section Remotae and C. bromoides in section Deweyanae. In both analyses, six representatives of section Arenariae cluster together in a terminal group, whereas C. disticha, C. repens and C. siccata form a basal cluster. C. maritima, as the only member of section Incurvae, shares this basal position. C. chordorrhiza is ascribed to section Chordorrhizeae and not ascribed to the paraphyletic section Divisae. C. vulpina and C. otrubae are assigned to section Vulpinae and separated from the heterogeneous section Stenorhynchae. The other members of sections Divisae, Muehlenbergianae, Multiflorae and Stenorhynchae are scattered throughout the trees. The representatives of section Foetidae are dispersed in both analyses, section Paniculatae appears to be non-monophyletic in the molecular results as well. The subgenus appears subdivided in at least four larger subgroups in all analyses. Whereas these subgroups are strongly supported, the relationships between these subgroups remain only poorly resolved.

EVIDENCE OF ORIBATID MITE HERBIVORY IN THE STEM OF A LATE TRIASSIC TREE FERN FROM ARIZONA

Small coprolite-bearing borings occur in the stem of the filicalean tree fern Itopsidema vancleaveii Daugherty from the Chinle Formation of Late Triassic Age (Carnian Stage) in Petrified Forest National Park, Arizona. These borings are restricted to parenchyma within the leaf petioles and among the adventitious roots of the root mantle. Although they are not lined by wound tissue, some of the borings in the leaf petioles contain small discontinuous masses of wound-tissue at a few places along some of the walls, indicating that the plant was alive when it was attacked. Coprolites within the borings generally are small (mostly about 40–50 μm in diameter and 85–100 μm in length) and oval in longitudinal section and round to weakly hexagonal in transverse section; they consist of very small particles of unidentifiable plant matter. Although the weakly hexagonal coprolites are similar to those produced by termites but they are an order of magnitude smaller. Furthermore, the borings are much smaller than those produced by known extant termites. It is likely that oribatid mites produced the coprolite-bearing borings and coprolites. This occurrence is significant because it bridges the Late Permian to Early Jurassic gap in the geologic record of endophagous mites and also contributes new data on arthropod activity during the Late Triassic in southwestern North America.

Evidence of oribatid mite herbivory in the stem of a Late Triassic tree fern from Arizona

Small coprolite-bearing borings occur in the stem of the filicalean tree fern Itopsidema vancleaveii Daugherty from the Chinle Formation of Late Triassic Age (Carnian Stage) in Petrified Forest National Park, Arizona. These borings are restricted to parenchyma within the leaf petioles and among the adventitious roots of the root mantle. Although they are not lined by wound tissue, some of the borings in the leaf petioles contain small discontinuous masses of wound-tissue at a few places along some of the walls, indicating that the plant was alive when it was attacked. Coprolites within the borings generally are small (mostly about 40–50 μm in diameter and 85–100 μm in length) and oval in longitudinal section and round to weakly hexagonal in transverse section; they consist of very small particles of unidentifiable plant matter. Although the weakly hexagonal coprolites are similar to those produced by termites but they are an order of magnitude smaller. Furthermore, the borings are much smaller than those produced by known extant termites. It is likely that oribatid mites produced the coprolite-bearing borings and coprolites. This occurrence is significant because it bridges the Late Permian to Early Jurassic gap in the geologic record of endophagous mites and also contributes new data on arthropod activity during the Late Triassic in southwestern North America.

Drilling behaviour of Octopus mimus Gould

The hole-drilling behaviour of the common octopus in North Chilean waters, Octopus mimus, on nine of its molluscan prey was studied in 70 specimens of 10–2000 g body weight in the laboratory. The occurrence of perforation was low, only 24.50% of the ingested prey were drilled. The bivalve Protothaca thaca (Molina) was the prey most frequently perforated, on 73.30% of occasions. The mean length of the P. thaca ingested increased significantly with octopus weight ( r 2=0.982, p<0.001) whether or not clams had previously been drilled. The form of the holes was usually a truncated cone with an oval section. The dimensions (length and width) of the external openings of the holes were significantly dependent on octopus weight and clam length ( p<0.001 in both cases). However, the dimensions of the internal openings of the holes were only dependent on octopus size. Location of the holes differed according to the prey species. Holes made in Mytilidae shells did not have any specific position, while the apex was the area selected for drilling the gastropod Concholepas concholepas (Brugière). The most specific location occurred when Protothaca thaca was perforated; 83% of the holes were located within or close to the myostracum of the anterior, mainly, and posterior adductor muscles of the clam. Within these small areas, there was a preference for the proximal edges.

Taxonomy of the Carex straminea complex (Cyperaceae)

The Carex straminea complex (section Ovales) consists of five species limited to hydric communities of eastern North America. Based upon gross morphology and perigynium structure, these species are closely aligned with the Carex albolutescens complex but not the western species Carex feta. An SEM investigation of the micromorphology of achene and style epidermis from 15 species of Carex section Ovales demonstrated much interspecific variation. As a result, these data could not confirm the relationship between the C. straminea complex and the C. albolutescens complex but did support the delimitation of section Ovales. Numerical analysis showed that characters of the inflorescence and perigynium are satisfactory for separating C. straminea from Carex hormathodes, a species limited to the Atlantic coast. Likewise, characters of inflorescence, pistillate scale, and perigynium could clearly separate the geographically widespread Carex alata from the Florida endemic species Carex vexans. A fifth and relatively distinctive species, Carex suberecta, was found to have a narrow ecological preference for fens and a distribution limited to the upper Midwest, with outlying populations in western Virginia. Putative natural hybrids are documented between Carex scoparia and Carex longii and some species in the C. straminea complex. Key words: Carex, Cyperaceae, section Ovales, taxonomy, SEM, biogeography, hybrid.

A Redescription of Cylicocyclus triramosus (Nematoda: Strongyloidea): A Parasite of the Zebra, Equus burchelli antiquorum

Cylicocyclus triramosus, a rare species of Cyathostominae from the southern African Burchell's zebra (Equus burchelli antiquorum) is redescribed, and a neotype is proposed. The external leaf-crown of the species consists of 30 elements and the internal leaf-crown numerous small and clear elements. The buccal capsule is cylindrical, oval in cross section, and approximately 3 times as wide as deep. The thin walls of the buccal capsule taper anteriorly from a large ringlike, hoop-shaped thickening around the posterior margin. The dorsal gutter is nipple-shaped. The mouth collar is notched dorsally and ventrally. The dorsal ray of the copulatory bursa is slightly elongate and distinctly set off from the lateral lobes. The branches of the dorsal ray have auxiliary branches. Appendages of the genital cone consist of 2 separated, large, semilunar plates with finger-shaped processes on the margins. The vulva-to-anus distance is greater than the tail length. The species is most similar to Cylicocyclus radiatus. Cylicocyclus triramosus differs from all similar species in the presence of dorsal and ventral notches in its mouth collar. In addition, C. triramosus also has a distinctive form of male genital cone appendage. Cylicocyclus radiatus differs further from C. triramosus in lacking a dorsal gutter and having a more elongate dorsal ray and a female tail nearly equal in length to the vulva-to-anus distance.

A New Species of Carex Section Ovales (Cyperaceae) Occuring in the Ozark Mountain Region

Carex ozarkana, a new species from Arkansas, Oklahoma, and extreme northeasternmost Texas is described and illustrated. It is a distinctive regional endemic of mineral soil wetlands most similar to the widespreadCarex albolutescens andC. longii but differing in its elongate, nodding inflorescences (on robust plants), prominently clavate spikes with elongate staminate bases, reddish brown pistillate and staminate scales, and wider achenes with a long apiculum.

New Species of the Southern African Genus Geissorhiza (Iridaceae: Ixioideae)

Three new species are recognized in the southern African Geissorhiza, a genus now including 84 species. Geissorhiza silenoides and G. rupicola are members of subgenus Geissorhiza and occur in the Ceres District of the southwestern Cape, South Africa. Both have pale pink flowers with unusually long perianth tubes for the genus. Geissorhiza silenoides is additionally distinguished by having unequal stamens, each filament being of a different length, scabrid-puberulent stems, and leaves with heavily thickened margins and midribs. Geissorhiza rupicola has unusual soft-textured corm tunics and, like G. silenoides, has leaves with strongly thickened margins and midribs. The third new species, G. uliginosa, is restricted to the Swartberg Mountains of the southern Cape and grows on wet cliffs and under waterfalls. It stands out in the genus in having the flowers solitary on the stems, and very soft-textured corm tunics that rapidly decay, sometimes leaving the corms apparently without tunics. All three new species occur in the southern and southwestern part of southern Africa, a region known for the richness and diversity of its flora, particularly of geophytes. More than half of the estimated 1750-1800 species of the petaloid monocot family, Iridaceae, occur in southern Africa (Goldblatt, 1994). The region is well known botanically, yet despite over 250 years of botanical exploration, novelties continue to be discovered there. Although the family is a numerically significant element of the flora of a large part of southern Africa, Iridaceae are most diverse in the southern and western coastal belt and adjacent mountains of the subcontinent, a region of mediterranean-type climate with winter rainfall and summer drought. Three new species of Geissorhiza, a genus virtually restricted to the winter rainfall zone of southern Africa, are described here. Some 81 species were admitted to the genus when it was last revised (Goldblatt, 1985), and the new species described here thus bring the total to 84. Geissorhiza is a member of Iridaceae subfamily Ixioideae, the largest of the four subfamilies currently recognized in Iridaceae (Goldblatt, 1990, 1991). It is one of the largest genera of the subfamily and one of the larger genera in the southern African flora. One of the new species, G. uliginosa, belongs in subgenus Weihea, which is characterized by concentric corm tunics, and G. silenoides and G. rupicola are members of subgenus Geissorhiza, species of which have the characteristic imbricate corm tunics that inspired the generic name, a Greek word meaning tiled root. 1. Geissorhiza silenoides Goldblatt & J. C. Manning, sp. nov. TYPE: South Africa. Western Cape: Ceres District, lower slopes of Gydo Pass, 20 Sep. 1993, Goldblatt & Manning 9739 (holotype, NBG; isotypes, K, MO, PRE, WAG). Figure 1A. Plantae 20-30 cm altae, cormo 5-7 mm diametro tunicis duris imbricatis, foiis li nearibus 1.2-1.5 mm latis marginibus costisque incrassatis, spica 4-7 florum, floribus pallide roseis, tubo perianthii cylindrico 15-17 mm longis, tepalis subaequalibus 12.5-14 x 6-7 mm, filamentis inaequalibus 4, 7 et 9 mm longis, antheris ca. 4.5 mm longis, stylo eccentrico. Plants 20-30 cm high. Cormn + ovoid, 5-7 mm diam., flattened slightly below on one side, the tunics woody, blackish, imbricate, the layers breaking below into triangular points. Cataphylls membranous, the upper light purple above the ground. Leaves 4, the lower 2 basal and longest, reaching to at least the middle of the stem, sometimes to the base of the spike, straight and erect or trailing, the blades linear, 1.2-1.5 mm wide, oval in section with 2 narrow grooves on each surface, the midrib much thickened, the margins raised and arched over the surface, the upper leaves cauline, sheathing for at least half their length, the blades like the basal, the uppermost sometimes only 9-12 mm long and enNovoN 5: 156-161. 1995. This content downloaded from 157.55.39.78 on Sun, 19 Jun 2016 06:24:39 UTC All use subject to http://about.jstor.org/terms Volume 5, Number 2 Goldblatt & Manning 157 1995 Geissorhiza from Southern Africa

Creep strain, elliptical release and additional stress of the elbows in main steam piping

Many investigators and engineers find that the ellipticity or ovality of an oval section of elbow operating at elevated temperature decreases over time. The ellipticity produced during the formation of the elbows vanishes because creep deformation occurs while the elbows are operating at such elevated temperatures as those found in steam-piping working conditions in power plants. This paper gives a theoretical derivation and a practical tracing measurement to demonstrate the ellipticity-releasing process. It proposes an ellipticity-time relationship which provides engineers with a means of taking account of the additional stress added at the elliptical sections of elbows. The additional stress added to oval sections of elbows is also derived as a function of time from the above ellipticity-time relationship. This stress-time function makes it easier for engineers to estimate the additional ellipticity stress and to assess the remanent life of elbows in steam pipes.

Propagation of high-frequency harmonic elastic waves excited by surface perturbation of a noncircular cylindrical cavity

A ray method based on geometrical optics is applied to solve the problem of propagation of harmonic elastic waves excited by the perturbation of the surface of a noncircular cylindrical cavity. Stresses are computed under plane strain conditions for a cavity in the form of a parabolic cylinder and for a cylindrical cavity with a Munger oval section subjected to a uniform, surface load or a surface load which is a cosinusoidal function of the angle.

Ultrastructural and cytochemical identification of peroxisomes in the ciliate Ichthyophthirius multifiliis.

The peroxisomes of the parasitic ciliate Ichthyophthirius multifiliis were studied, using ultrastructural and cytochemical techniques. In this ciliate most peroxisomes possess a circular or oval section less than 0.6 micron in diameter. However, some dumbbell-shaped and elongated peroxisomes could also be observed. These organelles were frequently associated with the mitochondria and were more abundant in the cell cortex than in the center of the ciliate. Small vesicles and dense nucleoids were usually present in the ultrathin sections of these peroxisomes. Peroxisomal vesicles and tubular structures were selectively impregnated with osmium tetroxide. Catalase was detected by cytochemical techniques in I. multifiliis peroxisomes.

A simplified method for elastic calculation for pipes, based on the beam theory and allowing for section ovalization

It is proposed that variables corresponding to section deformation (ovalization) should be added to the variables of the beam type used in the classic method for pipe calculation. Section ovalization is formulated on the basis of analytical calculations of the shell type. The calculation of flexibility and the stresses that allow for these ovalization deformations are in this way considerably improved with respect to calculation by the classic method for a cost that is scarcely higher.

Chromosome Counts of Carex Section Ovales

Chromosome counts for eight species of Carex section Ovales were determined (C. bebbii, C. crawfordii, C. integra, C. microptera, C. pachystachya, C. praticola, C. preslii, and C. subfusca). Combined with data from previous studies in the sect. Ovales, chromosome number variability is observed within individuals, populations, and species. Counts from 10 sib families of C. pachystachya indicate that structural rearrangements occur between generations. A total of 38 of the approximately 70 species of the section have been counted. Sixteen species have been counted more than once: seven of these show no chromosome number variation, and nine have aneuploid series of numbers. Two forms of chromosome change are identified in the section: structural rearrangements and aneuploidy. At present the data cannot be used to determine whether strict aneuploidy or agmatoploidy accounts for the aneuploid variation.