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Dennis P Gordon, Kjetil L Voje, Paul D Taylor
The cheilostome bryozoan family Steginoporellidae in New Zealand comprises seven living species of Steginoporella. Three of these are new to science-Steginoporella discors n. sp., Steginoporella lineata n. sp. and Steginoporella modesta n. sp.-and one (Steginoporella magnifica) additionally occurs as a Plio-Pleistocene fossil. A new Early Pleistocene fossil species, Steginoporella tiara n. sp., is also recognised. The living species exhibit the full range of colonial morphologies known for the genus, and two of the new deep-shelf taxa described herein have the smallest known colonies, both linear, not exceeding 5 mm in width and 22 mm in length...
November 17, 2017: Zootaxa
X-X Yao, Q-W Meng, G-Q Li
An obvious challenge faced by most terrestrial insects is maintaining water homeostasis in an arid environment. Current research suggests aquaporins may be evolved to meet the challenge. However, up to now, this suggestion has not been verified in any insect that feeds upon solid food with mandibulate mouthparts. In the present paper, nine putative aquaporin genes [Tribolium castaneum big brain, T. castaneum Drosophila integral protein (TcDrip), T. castaneum Pyrocoelia rufa integral protein (TcPrip), T. castaneum aquaporin 12-like, T...
April 2018: Insect Molecular Biology
Harald Wolf
Scorpions possess specialised chemosensory appendages, the pectines. These comb-shaped limbs are located ventrally behind the walking legs. Like the antennae of mandibulate arthropods, they also serve a mechanosensory function. However, more than 90% of the sometimes well above 100,000 sensory neurons projecting from a pectine to the central nervous system are chemosensory. There are two primary projection neuropils. The posterior one, immediately adjacent to the pectine nerve entrance, has an intriguing substructure reminiscent of the olfactory glomeruli observed in the primary chemosensory neuropils of many arthropods and indeed of most bilaterian animals...
November 2017: Arthropod Structure & Development
Gregory D Edgecombe
The past five years have witnessed a renewed interest in discrete morphological characters as a source of phylogenetic data, after a decade or more of their dismissal in favor of molecules-only approaches. This has stemmed in large part from refinements in total evidence dating, which requires morphological character matrices for extinct and extant taxa as well as temporal data from fossils. The unique contribution of palaeontology is stem groups, revealing the sequence of character acquisition in long-branch terminals and otherwise unknown character combinations and/or character states in extinct phenotypes...
September 1, 2017: Integrative and Comparative Biology
Gregory D Edgecombe
Cambrian fossils underpin a new hypothesis for body plan evolution in the deepest branching lineages of jawed arthropods, the mandibulates.
August 21, 2017: Current Biology: CB
Emily V W Setton, Logan E March, Erik D Nolan, Tamsin E Jones, Holly Cho, Ward C Wheeler, Cassandra G Extavour, Prashant P Sharma
The deutocerebral (second) head segment is putatively homologous across Arthropoda, in spite of remarkable disparity of form and function of deutocerebral appendages. In Mandibulata this segment bears a pair of sensory antennae, whereas in Chelicerata the same segment bears a pair of feeding appendages called chelicerae. Part of the evidence for the homology of deutocerebral appendages is the conserved function of homothorax (hth), which has been shown to specify antennal or cheliceral fate in the absence of Hox signaling, in both mandibulate and chelicerate exemplars...
October 1, 2017: Developmental Biology
Andy Sombke, Torben Stemme
BACKGROUND: Given the numerous hypotheses concerning arthropod phylogeny, independent data are needed to supplement knowledge based on traditional external morphology and modern molecular sequence information. One promising approach involves comparisons of the structure and development of the nervous system. Along these lines, the morphology of serotonin-immunoreactive neurons in the ventral nerve cord has been investigated in numerous tetraconate taxa (Crustacea and Hexapoda). It has been shown that these neurons can be identified individually due to their comparably low number, characteristic soma position, and neurite morphology, thus making it possible to establish homologies at the single cell level...
2017: Zoological Letters
Cédric Aria, Jean-Bernard Caron
Retracing the evolutionary history of arthropods has been one of the greatest challenges in biology. During the past decade, phylogenetic analyses of morphological and molecular data have coalesced towards the conclusion that Mandibulata, the most diverse and abundant group of animals, is a distinct clade from Chelicerata, in that its members possess post-oral head appendages specialized for food processing, notably the mandible. The origin of the mandibulate body plan, however, which encompasses myriapods, crustaceans and hexapods, has remained poorly documented...
May 4, 2017: Nature
Ralf Janssen
Evolution of segmented limbs is one of the key innovations of Arthropoda, allowing development of functionally specific specialized head and trunk appendages, a major factor behind their unmatched evolutionary success. Proximodistal limb patterning is controlled by two regulatory networks in the vinegar fly Drosophila melanogaster, and other insects. The first is represented by the function of the morphogens Wingless (Wg) and Decapentaplegic (Dpp); the second by the EGFR-signaling cascade. While the role of Wg and Dpp has been studied in a wide range of arthropods representing all main branches, that is, Pancrustacea (= Hexapoda + Crustacea), Myriapoda and Chelicerata, investigation of the potential role of EGFR-signaling is restricted to insects (Hexapoda)...
May 2017: Evolution & Development
Adrian Brückner, Günther Raspotnig, Katja Wehner, Reinhard Meusinger, Roy A Norton, Michael Heethoff
Cyanogenesis denotes a chemical defensive strategy where hydrogen cyanide (HCN, hydrocyanic or prussic acid) is produced, stored, and released toward an attacking enemy. The high toxicity and volatility of HCN requires both chemical stabilization for storage and prevention of accidental self-poisoning. The few known cyanogenic animals are exclusively mandibulate arthropods (certain myriapods and insects) that store HCN as cyanogenic glycosides, lipids, or cyanohydrins. Here, we show that cyanogenesis has also evolved in the speciose Chelicerata...
March 28, 2017: Proceedings of the National Academy of Sciences of the United States of America
Sung-Tak Lee, Na-Rae Choi, Jae-Min Song, Sang-Hun Shin
BACKGROUND: The aim of this report is to present a new reference for aesthetic mandible surgery using three-dimensional cone-beam computed tomography-based treatment planning for orthognathic surgery which can be implemented in surgical planning and perioperative procedure. METHODS: To make an objective standard for evaluating aesthetic mandibular outline, we make an aesthetic scoring criteria with consideration of asymmetry, broad mandibular border line, and prominent mandibular angle...
December 2016: Maxillofacial Plastic and Reconstructive Surgery
M Xu, X H Chen, X L Zhang, R Y Li
No abstract text is available yet for this article.
November 9, 2016: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
Nicholas J Strausfeld, Xiaoya Ma, Gregory D Edgecombe
The discovery of fossilized brains and ventral nerve cords in lower and mid-Cambrian arthropods has led to crucial insights about the evolution of their central nervous system, the segmental identity of head appendages and the early evolution of eyes and their underlying visual systems. Fundamental ground patterns of lower Cambrian arthropod brains and nervous systems correspond to the ground patterns of brains and nervous systems belonging to three of four major extant panarthropod lineages. These findings demonstrate the evolutionary stability of early neural arrangements over an immense time span...
October 24, 2016: Current Biology: CB
A Yilmaz, M Akcaalan
BACKGROUND: Clinical detection of anatomic narrowing of the upper airway may facilitate early recognition of obstructive sleep apnoea (OSA). The aim of this study was to investigate whether anthropometric measurement can be used to predict OSA. MATERIALS AND METHODS: One hundred forty-seven subject were included from those patients who were referred to our sleep laboratory with suspected sleep apnoea. All patients were divided two groups with respect to the apnoea-hypopnoea index (AHI)...
2017: Folia Morphologica (Warsz)
Jessica E Martin, Karen Christensen, Yvonne Vizzier-Thaxton, Malcolm A Mitchell, Dorothy E F McKeegan
A novel approach to pre-slaughter stunning of chickens has been developed in which birds are rendered unconscious by progressive hypobaric hypoxia. Termed Low Atmospheric Pressure Stunning (LAPS), this approach involves application of gradual decompression lasting 280s according to a prescribed curve. We examined responses to LAPS by recording behaviour, electroencephalogram (EEG) and electrocardiogram (ECG) in individual male chickens, and interpreted these with regard to the welfare impact of the process...
September 1, 2016: Physiology & Behavior
Derek E G Briggs, Derek J Siveter, David J Siveter, Mark D Sutton, David Legg
The ∼430-My-old Herefordshire, United Kingdom, Lagerstätte has yielded a diversity of remarkably preserved invertebrates, many of which provide fundamental insights into the evolutionary history and ecology of particular taxa. Here we report a new arthropod with 10 tiny arthropods tethered to its tergites by long individual threads. The head of the host, which is covered by a shield that projects anteriorly, bears a long stout uniramous antenna and a chelate limb followed by two biramous appendages. The trunk comprises 11 segments, all bearing limbs and covered by tergites with long slender lateral spines...
April 19, 2016: Proceedings of the National Academy of Sciences of the United States of America
Xiaorui Su, Bowei Zhang, Li Su, Rong Xu, Feihong Wu, Haijun Li, Dechang Peng
OBJECTIVE: To discuss the soft palate, hard palate and mandibule for the pathogenesis and clinical treatment of patients who have obstructive sleep apnea hypopnea syndrome. METHOD: There were 52 patients with OSAHS diagnosed by the PSG and 32 cases of normal healthy volunteers in our hospital. All objects were given 128 slice spiral CT scan of the upper airway. We measured the related indexes of the soft palate, hard palate and mandible, then analysed statistical differences between them and did Pearson correlation analysis with apnea hypoventilation index (AHI), average blood oxygen saturation (MSaO2) in PSG...
October 2015: Journal of Clinical Otorhinolaryngology, Head, and Neck Surgery
Javier Ortega-Hernández, Graham E Budd
Recent studies have clarified the segmental organization of appendicular and exoskeletal structures in the anterior region of Cambrian stem-group Euarthropoda, and thus led to better understanding of the deep evolutionary origins of the head region in this successful animal group. However, there are aspects of the anterior organization of Palaeozoic euarthropods that remain problematic, such as the morphological identity and significance of minute limb-like projections on the anterior region in stem and crown-group representatives...
March 2016: Arthropod Structure & Development
Haixin Qian, Fuqiang Zhang, Ting Jiao
PATIENT: A fifty-year-old man received embolization for mandibular hemangioma two years ago, and the surgeon had placed four implants in his mandible and made a removable denture upon the implants. His denture however fractured repeatedly in the past years. After examination and communication with the patient, an implant-assisted overdenture incorporating bar attachment combined ERA attachment and Locator abutment was re-fabricated. A sixteen months follow-up showed acceptable outcome...
October 2016: Journal of Prosthodontic Research
Ariel D Chipman
BACKGROUND: Our understanding of the early evolution of the arthropod body plan has recently improved significantly through advances in phylogeny and developmental biology and through new interpretations of the fossil record. However, there has been limited effort to synthesize data from these different sources. Bringing an embryological perspective into the fossil record is a useful way to integrate knowledge from different disciplines into a single coherent view of arthropod evolution...
2015: BMC Evolutionary Biology
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