A bored cup of the Mississippian crinoid Synbathocrinus Phillips

Only the second bored cup of the disparid crinoid Synbathocrinus conicus Phillips is described, infested by a pit of Oichnus paraboloides Bromley. Both bored specimens are from the Mississippian of Salthill Quarry, Clitheroe, Lancashire, UK, although the search for others has extended from northern Europe to North America. The first, described 30 years ago, infested a plate triple-junction of the cup on the presumed up-current side of the crinoid; the new specimen, in contrast, is in the centre of a radial plate, which is inflated as a growth response to infestation. We informally name the producing organism the ‘Salthill bug’. Although unknown, this was a small, unmineralized invertebrate that commonly attached to elevated positions on living crinoids and was likely a filter feeder. It constructed a domicile by boring into the crinoid endoskeleton, and could invade both living and dead crinoid skeletons. On crinoid stems it was commonly gregarious, a habit perhaps favoured by secretions by the first ‘Salthill bug’ to settle, attracting conspecific larvae and similar to the settling patterns of some modern sessile invertebrates. Comparison with Oichnus from Trearne Quarry, Ayrshire, UK, reveals several differences between the pits in infested crinoids at the two sites.

A new species of Parathyone (Holothuroidea: Dendrochirotida: Cucumariidae) from northeastern Brazil, with a key to species

A new species of Dendrochirotida sea cucumber, Parathyone itapuaensis, is described and illustrated herein based on specimens collected from rocky intertidal regions of the northeastern coast of Brazil. The new species is characterized by a suite of morphological characters revealed by light stereomicroscope, SEM and microCT studies of the calcareous ring, dermal ossicles, Polian vesicles and madreporite. Parathyone itapuaensis sp. nov. is characterized by having 10 tentacles, two Polian vesicles and single madreporite; length of anterior process (radial plate) larger than length of the base of the radial plate; body wall with buttons with triangular knobs and knobbed multiperforated plates in the anal region; and tentacles with arched rods, knobbed in the margins and shallow cups knobbed in the outer and inner surfaces. A key to the recognition of Parathyone species is given.

Effect of an axial-radial plate reactor modifications on a mega methanol plant production

Axial-radial flow plate reactors have been recently considered as efficient and practical types of reactors for methanol synthesis. Generally, an axial–radial reactor (AR) consists of two main parts namely the axial section and the radial section and the vast majority of the feed enters the radial section. Moreover, the structure of AR has a space above the axial part, which can add an adiabatic bed in the system. In this study, the performance of two novels AR configurations is investigated to improve the effectiveness of the axial–radial plate reactor. In the first configuration, the optimum length of the adiabatic bed is calculated and the adiabatic bed is located above the axial section inside the AR and is named IAAR. Therefore, in IAAR the feed of the axial section just enters the adiabatic bed and warms up. On the other configuration, the adiabatic bed with the optimum length is placed outside the reactor and is named OAAR. Therefore, in OAAR the total feed passes through the adiabatic bed, highly warms up, then cools to the optimum temperature in a heat exchanger, and finally enters AR. Two-dimensional mathematical modeling via orthogonal collocation on the finite element method is developed to compare the performance of two configurations. The results show that the maximum proportion of methanol produces in IAAR, which is approximately 3.8% higher than that produced in conventional AR due to utilizing an adiabatic bed inside the AR and superior gas distribution in the process. Momentum, mass, and heat equations are calculated and molar flow rates, mole fractions and temperatures are depicted along the radius and the length of the three configurations.

A new species of Schindler's fish (Teleostei: Gobiidae: Schindleria) from the Malay Archipelago (Southeast Asia), with notes on the caudal fin complex of Schindleria

Schindleria macrodentata sp. nov., a new species of the paedomorphic gobiid fish genus Schindleria, is described from the Malay Archipelago. The two specimens were collected in 1929 during the “Dana Expedition” in the Molucca Sea between Sulawesi and Halmahera islands (00°29′N, 125°54′E) (Indonesia) and in the Sulu Sea close to Panay Island (11°43’N, 121°43′E) (Philippines). The new species is characterized by a slender body (body depth at pectoral fin base 3.6–3.7 % of SL and at anal fin origin 3.9–4.8 % of SL), a long second dorsal fin (first dorsal fin absent) originating distinctly anterior to the origin of the anal fin (predorsal length 61.8–65.2 % of SL and preanal length 71.7–75.8 % of SL), a short tail (from anus to tip of longest caudal fin ray) (22.1 % of SL), 19–20 dorsal fin rays and 10 anal fin rays, first anal fin ray below 9th dorsal fin ray, few large, widely spaced teeth in the upper and the lower jaws (7 on the premaxilla and 6 on the dentary), an elongated pectoral radial plate (length 3.7–4.5 % of SL) and, in the caudal skeleton, a procurrent ray with an additional spiny process at its base. No distinct urogenital papilla and no pigmentation on body are developed. In this study we present three morphological traits until now not considered as diagnostic characters for Schindleria, the shape of the pectoral radial plate, the shape of the last procurrent caudal spine and the shape of the arch formed by the lower jaw. We also discuss the caudal-fin skeleton of Schindleria, a character developing beyond the larval stages. The record of S. macrodentata is the first of the genus Schindleria for Indonesia and, at more than 100 km distant to the next shore, it is the first offshore record of a Schindler's fish.

Hybrid radial plate-type elastic metamaterials for lowering and widening acoustic bandgaps

In this paper, we present theoretical investigation on the wave propagation and acoustic bandgap characteristics in hybrid radial plate-type elastic metamaterials constituted of periodic double-sides composite stubs deposited on one-dimensional binary radial phononic crystal plate. The dispersion relations and the displacement fields of the eigenmodes are calculated by using the finite element method on the basis of two-dimensional axial symmetry models. Numerical results show that the proposed hybrid radial plate-type elastic metamaterial can generate lowering and widening acoustic bandgaps and yield a significant expansion of the relative bandwidth by a factor of 5 compared to the traditional radial plate-type elastic metamaterial with double-sided composite stubs. The displacement fields of the eigenmodes are applied to reveal the formation mechanism of lowering and widening acoustic bandgaps. In addition, the influences of the physical and geometrical parameters on the bandgaps are further performed. These low-frequency broadband acoustic bandgap properties in the radial plate-type elastic metamaterials can probably be applied to vibration and noise reduction in the rotary machines and structures.

A re-interpretation of the ambulacral system of Eumorphocystis (Blastozoa: Echinodermata) and its bearing on the evolution of early crinoids

Recent debates over the evolutionary relationships of early echinoderms have relied heavily on morphological evidence from the feeding ambulacral system. Eumorphocystis, a Late Ordovician diploporitan, has been a focus in these debates because it bears ambulacral features that show strong morphological similarity to early crinoid arms. Undescribed and well-preserved specimens of Eumorphocystis from the Bromide Formation (Oklahoma, USA) provide new data illustrating that composite arms supported by a radial plate that bear a triserial arrangement of axial and extraxial components encasing a coelomic extension can also be found in blastozoans. Previous reports have considered these arm structures to be restricted to only crinoids; these combined features have not been previously observed in blastozoan echinoderms. Phylogenetic analyses suggest that Eumorphocystis and crinoids are sister taxa and that shared derived features of these taxa are homologous. This evidence concerning Eumorphocystis’ arms suggests that crinoid arms were derived from a specialized blastozoan ambulacral system that lost feeding brachioles and strongly suggests that crinoids are nested within blastozoans.

Radial Plate Fixation of Distal Radius Fracture

Background: A radial incision with radial plate fixation for distal radius fracture has historically been avoided due to its risk to the superficial branch of the radial nerve (SBRN). With careful technique, it is possible to avoid injury to the SBRN, thereby minimizing the soft tissue injury associated with other approaches. We compare subjective and objective functional outcomes of radial plate fixation surgeries that we performed with those of dorsal and volar plate fixation in current literature. Methods: Patients at a single center who underwent radial plate fixation for an AO type A or AO type B distal radius fracture between December 2006 and December 2014 were enrolled in the study. Postoperative grip strength and 3-digit pinch strength were measured systematically in the injured and uninjured wrists. Patients also completed a Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire to assess subjective outcomes. Results: Thirty-six patients met our inclusion criteria and had available medical records. Postoperative grip strength in the injured wrist was significantly lowered—68% compared with the uninjured wrist. After subgroup analysis of dominant and nondominant wrist injuries, there was no significant difference in grip strength between injured and uninjured wrists. There was no significant decrease in postoperative 3-digit pinch strength in the injured wrist—89% compared with the uninjured wrist. The mean QuickDASH score for our study participants was 20.9. Conclusions: Radial plate fixation is an effective approach for distal radius fractures. Objective and subjective outcomes are noninferior to those of a dorsal or volar approach.