scholarly journals A newly identified left–right asymmetry in larval sea urchins

2016 ◽  
Vol 3 (8) ◽  
pp. 160139 ◽  
Author(s):  
Jason Hodin ◽  
Keegan Lutek ◽  
Andreas Heyland

Directional asymmetry (DA) in body form is a widespread phenomenon in animals and plants alike, and a functional understanding of such asymmetries can offer insights into the ways in which ecology and development interface to drive evolution. Echinoids (sea urchins, sand dollars and their kin) with planktotrophic development have a bilaterally symmetrical feeding pluteus larva that undergoes a dramatic metamorphosis into a pentameral juvenile that enters the benthos at settlement. The earliest stage of this transformation involves a DA: a left-side invagination in mid-stage larvae leads to the formation of the oral field of the juvenile via a directionally asymmetric structure called the echinus rudiment. Here, we show for the first time in two echinoid species that there is a corresponding DA in the overall shape of the larva: late-stage plutei have consistently shorter arms specifically on the rudiment (left) side. We then demonstrate a mechanistic connection between the rudiment and arm length asymmetries by examining rare, anomalous purple urchin larvae that have rudiments on both the left and the right side. Our data suggest that this asymmetry is probably a broadly shared feature characterizing ontogeny in the class Echinoidea. We propose several functional hypotheses—including developmental constraints and water column stability—to account for this newly identified asymmetry.

2014 ◽  
Vol 31 (04) ◽  
pp. 228-232
Author(s):  
P. Parés-Casanova

Abstract Introduction and material and methods. We studied a sample of 37 dentulous dry mandibles from European wild board (Sus scrofa) and compared both the right and left sides in their dorsal aspect. To study the influence of age, the samples were grouped according to dental status: “subadults” (erupting 3rd M, n=22) and “adults” (fully erupted 3rd M, n=15). Individual levels of asymmetry were analysed from x- and y-coordinates of the 16 landmarks on the dorsal aspect of the mandible. Results. The analysis separated directional asymmetry (one side of the body with a larger character value than the other) and fluctuating asymmetry (small random deviations from perfect symmetry), which were both found to be significant. Conclusion. The condylar ramus was the most asymmetric structure for both age groups.


Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 145 ◽  
Author(s):  
Yan Wang ◽  
Jolanta Brożek ◽  
Wu Dai

Mouthpart structures were observed in four species of Largidae using scanning electron microscopy to investigate their morphological disparity, and linked to changes in feeding specialization. The examined species are pests that feed mainly on seeds and plant sap of forbs, shrubs, and trees. Their external mouthparts are described in detail for the first time herein. The cone-like labrum and four-segmented tube-like labium are shorter in Physopelta species than in Macrocheraia grandis (Grey). The labium surface in all studied species bears nine types of sensilla (St1-St2, Sb1-3, Sch, Sca1-2, Sm). The distributions of sensilla on particular labial segments varies among the studied species. The tripartite apex of the labium consists of two lateral lobes and an apical plate that is partly divided in Physopelta species, and not divided in Macrocheraia. Each lateral lobe possesses a sensillar field with 10 thick-walled uniporous sensilla basiconica, one multiporous sensillum styloconicum, and one long non-porous hair sensillum. Each mandibular stylet tip in M. grandis has a central tooth placed anteriorly and pairs of teeth arranged dorso-laterally. In Physopelta, there are one or two central teeth placed anteriorly but two pairs of teeth dorso-laterally. In all studied species, the inner surfaces of the mandibular stylets have scale-like projections. A left–right asymmetry of the maxillary stylets is noticeable; the external end of the right maxillary stylet is smooth and slightly tapered in M. grandis and evidently wider (spoon–like) in the three species of Physopelta, while the left end of the stylets is straight and narrow in M. grandis in contrast to Physopelta, in which the end is straight and wide. No differences in the internal structure of the maxillary stylets were observed among the studied species. Based on structural differences, we inferred that the mandibles and maxillae are more adapted for seed-sucking in Physopelta species than in M. grandis. M. grandis has the ends of the maxillae more narrowed, a trait more adapted for sucking sap from phloem or parenchymal cells.


2019 ◽  
Vol 12 (3) ◽  
pp. 229-237 ◽  
Author(s):  
Alban Revy ◽  
François Hallouard ◽  
Sandrine Joyeux-Klamber ◽  
Andrea Skanjeti ◽  
Catherine Rioufol ◽  
...  

Objective: Recent gallium-68 labeled peptides are of increasing interest in PET imaging in nuclear medicine. Somakit TOC® is a radiopharmaceutical kit registered in the European Union for the preparation of [68Ga]Ga-DOTA-TOC used for the diagnosis of neuroendocrine tumors. Development of a labeling process using a synthesizer is particularly interesting for the quality and reproducibility of the final product although only manual processes are described in the Summary of Product (SmPC) of the registered product. The aim of the present study was therefore to evaluate the feasibility and value of using an automated synthesizer for the preparation of [68Ga]Ga-DOTA-TOC according to the SmPC of the Somakit TOC®. Methods: Three methods of preparation were compared; each followed the SmPC of the Somakit TOC®. Over time, overheads, and overexposure were evaluated for each method. Results: Mean±SD preparation time was 26.2±0.3 minutes for the manual method, 28±0.5 minutes for the semi-automated, and 40.3±0.2 minutes for the automated method. Overcost of the semi-automated method is 0.25€ per preparation for consumables and from 0.58€ to 0.92€ for personnel costs according to the operator (respectively, technician or pharmacist). For the automated method, overcost is 70€ for consumables and from 4.06€ to 6.44€ for personnel. For the manual method, extremity exposure was 0.425mSv for the right finger, and 0.350mSv for the left finger; for both the semi-automated and automated method extremity exposure were below the limit of quantification. Conclusion: The present study reports for the first time both the feasibility of using a [68Ga]- radiopharmaceutical kit with a synthesizer and the limits for the development of a fully automated process.


Author(s):  
Evan Osborne

Does humanity progress primarily through leaders organizing and directing followers, or through trial and error by individuals free to chart their own path? For most of human history ruling classes had the capacity and the desire to tightly regiment society, to the general detriment of progress. But beginning in the 1500s, Europeans developed a series of arguments for simply leaving well enough alone. First in the form of the scientific method, then in the form of free expression, and finally in the form of the continuously, spontaneously reordered free market, people began to accept that progress is hard, and requires that an immense number of mistakes be tolerated so that we may learn from them. This book tells the story of the development of these three ideas, and for the first time tells of the mutual influence among them. It outlines the rise, and dramatic triumph, of each of these self-regulating systems, followed by a surprising rise in skepticism, especially in the economic context. Such skepticism in the 20th century was frequently costly and sometimes catastrophic. Under the right conditions, which are more frequent than generally believed, self-regulating systems in which participants organize themselves are superior. We should accept their turbulence in exchange for the immense progress they generate.


Author(s):  
Andrew McNeillie
Keyword(s):  

It is now widely acknowledged, and far beyond Ireland, that Tim Robinson’s two volumes jointly known as Stones of Aran (‘Pilgrimage’ and ‘Labyrinth’) are modern classics, exemplary in every way of how to write about place and to do so with a formal, literary accomplishment that more than earns the right to nod at Ruskin’s own classic. In 2012, Robinson went back to Árainn, the largest of the three islands, for the first time in nearly ten years. He did so at the urging of Andrew McNeillie, with whom he spent two and a half days revisiting old haunts. This chapter makes account of the occasion and uses, in the process, a unique document provided by Robinson as an experiment in annotating his work. This prompts McNeillie to investigate some of his own annotations and footnotes to Aran.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Abbas Basiri ◽  
Iman Ghanaat ◽  
Hamidreza Akbari Gilani

Abstract Background Although involvement of the urinary system is not uncommon, endometriosis in the kidneys is rare. To date, laparoscopic partial nephrectomy has been the preferred approach for managing renal endometriosis. Here, we report for the first time the results of laparoscopic removal of a renal capsular endometriosis in a malrotated kidney in an attempt to save the whole kidney parenchyma, in terms of feasibility and safety. Case presentation A 37-year-old female presented with periodic right flank pain associated with her menstrual cycle. On imaging, a malrotated right kidney and a hypodense irregular-shaped lesion measuring 30 * 20 * 15 mm were seen in the superior portion of the right perinephric space. Histologic evaluation of the ultrasound-guided biopsy was consistent with renal capsular endometriosis. The patient underwent laparoscopic surgery to remove the capsular mass while preserving the normal renal parenchyma. Pathological examination of the biopsy obtained during surgery was in favor of renal endometriosis. At 6-month follow-up, the patient’s pain had completely disappeared and no complications had occurred. In addition, imaging did not show any remarkable recurrence. Conclusion Renal endometriosis should be strongly considered as a differential diagnosis in female patients with a renal capsular mass and exacerbation of flank pain during menstruation. Based on our experience, with preoperative needle biopsy and clearing the pathology, laparoscopic removal of the mass in spite of renal anatomic abnormality is feasible and safe and thus could be considered as a possible treatment option.


Author(s):  
Stephen Bendall ◽  
Paul Halliwell ◽  
Andrew Goldberg ◽  
Andrew Robinson
Keyword(s):  

Neurosurgery ◽  
2004 ◽  
Vol 54 (2) ◽  
pp. 500-504 ◽  
Author(s):  
Patrick Beauchesne ◽  
Jean-François Mosnier ◽  
Thierry Schmitt ◽  
Jacques Brunon

Abstract OBJECTIVE AND IMPORTANCE Schwannomas occurring in the neuraxis are very rare. Usually, these tumors are benign. Primary malignant intracerebral nerve sheath tumors are extremely rare, with only five documented cases in the international literature. We report one case of a primary malignant intracerebral nerve sheath tumor occurring in the right cerebral peduncle of a 35-year-old man. CLINICAL PRESENTATION Magnetic resonance imaging revealed a heterogeneous peripherally enhancing mass of the right cerebral peduncle, surrounded by a small edema. INTERVENTION Unlike the five cases previously reported, this is the first time a stereotactic biopsy has been performed, and this is the only patient who responded to cranial radiation therapy for approximately 2 years. When the tumor recurred, a systemic chemotherapy treatment was prescribed. No positive response was seen, and the patient died 29 months after the initial diagnosis. CONCLUSION An accurate diagnosis and planned aggressive treatment seem to be the key elements in the management of the disease.


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