Flapper Valve and Hayfork: Functional anatomy and taxonomic potential of the Gastric Mill of Bairdioidea (Ostracoda, Podocopida)

Zootaxa ◽  
2018 ◽  
Vol 4378 (1) ◽  
pp. 1 ◽  
Author(s):  
ROSALIE F. MADDOCKS
Keyword(s):  
Particle Size ◽  
Functional Anatomy ◽  
Check Valve ◽  
Lateral Wall ◽  
Gastric Mill ◽  
Taxonomic Significance ◽  
Decapod Crustaceans ◽  
It Projects ◽  
Anatomical Analysis ◽  
Fossil Preservation

The chewing apparatus of the Bairdioidea has been described just once and is rarely illustrated, but it might have more taxonomic significance than commonly supposed. It is constructed as a flapper valve (hinged check valve), which is unique among Ostracoda and unusual among animals. It projects into the midgut and is substantially enveloped by it. It serves three functions: to move bites of food into the stomach, to close the esophagus against back-flow, and to pack strands of food and mucus onto the rotating food ball. It is probably less effective for macerating the food to reduce particle size. Two braces anchor this structure to the lateral wall of the forehead. It is lined by cuticle that is shed at each molt, and the formation of food balls is interrupted during molting. In its construction and action, this apparatus is quite unlike the gastric mill of decapod crustaceans, and it shows only distant homology to the dorsal Wulst of Cypridoidea. Some architectural details differ among families and genera. The well-sclerotized plate has some potential for fossil preservation in exceptional circumstances. A revised anatomical analysis is presented, together with an annotated glossary of terms. 

scholarly journals Wood functional anatomy of Chiococca alba Hitch. (Rubiaceae) from cerrado

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
João Carlos Ferreira de Melo Junior ◽  
Maick William Amorim ◽  
Gustavo Borda De Oliveira ◽  
Celso Voos Vieira
Keyword(s):  
Wood Anatomy ◽  
Secondary Xylem ◽  
Structural Characteristics ◽  
Functional Anatomy ◽  
Small Diameter ◽  
Great Resistance ◽  
Transport Efficiency ◽  
Anatomical Analysis ◽  
Ecological Aspects ◽  
Perforation Plates

The wood anatomy is able to evidence systematic and ecological aspects associated with the evolution and functionality of the secondary xylem. The present study was carried out using wood of Chiococca alba (Rubiaceae) from cerrado (savannah), to describe its anatomy and to verify if the hydraulic architecture of this species corroborates the theory that postulates the functional tendency that optimizes the transport efficiency associated with safety. The anatomical analysis followed the conventional protocols of wood anatomy. Different indexes of wood hydraulics quantification were calculated, such as solitary vessels index, vessel grouping, conductivity, vessel collapse, theoretical resistance to vessel implosion and mesomorphism. The structural characteristics described for C. alba are in agreement with the general anatomical descriptions for the Rubiaceae family that relate the presence of exclusively solitary vessels and small diameter, simple perforation plates, alternate intervessel pits, apotracheal parenchyma in species with non-septate fibers and narrow and heterogeneous rays. The calculated indexes showed that C. alba is a xerophyte species with great resistance to the collapse of the vessels during the transport of water, little vulnerability to embolism and relative efficiency in the transport when compared to other species of its subfamily (Cinchonoideae) in function of the typical low water availability of the savannah soil.

Double Dissociation Between Visual Recognition and Picture Naming

Neurosurgery ◽  
2013 ◽  
Vol 72 (4) ◽  
pp. 678-686 ◽  
Author(s):  
Santiago Gil-Robles ◽  
Amelie Carvallo ◽  
Maria del Mar Jimenez ◽  
Anne Gomez Caicoya ◽  
Reinaldo Martinez ◽  
...  
Keyword(s):  
Picture Naming ◽  
Semantic Processing ◽  
Visual Recognition ◽  
Temporal Cortex ◽  
Functional Anatomy ◽  
Occipital Lobe ◽  
Lateral Wall ◽  
Awake Surgery ◽  
Double Dissociation ◽  
Occipital Pole

Abstract BACKGROUND: Study of the corticosubcortical functional anatomy of reading and picture naming. OBJECTIVE: To study the role of the left basal occipitotemporal area and its white matter pathways. METHODS: Three patients underwent awake surgery for lesions in the left basal posterotemporal region with intraoperative electrostimulations. Intraoperative testing consisted of naming, reading, and recognition of symbols. Location of the stimulation sites was obtained by comparing the surgical cavity in the postoperative magnetic resonance imaging with the tags precisely located in each one of these sites seen on intraoperative photographs. RESULTS: A double dissociation was elicited, inducing specific visual recognition and reading disturbances during stimulation in the left posterobasal temporal cortex, without naming impairment. Stimulation of the inferior part of the sagittal stratum (inferior longitudinal fascicle) generated the same response, while a specific picture-naming impairment, consisting of semantic paraphasia, was obtained when stimulating superiorly to this fascicle, over the lateral wall and roof of the ventricle (inferior fronto-occipital fascicle). CONCLUSION: We propose the existence of a dual visual language route in the left dominant hemisphere. The first pathway seems to run basally, from the occipital lobe to the posterobasal temporal cortex, mediated by the left inferior longitudinal fascicle, subserving visual recognition. The second pathway might run superiorly and more medially, from the occipital pole directly to the frontal areas, and could be underlain by the inferior fronto-occipital fascicle, involved in naming (semantic processing). Such a model might have both fundamental and clinical implications for the selection of the tasks during awake mapping as well as for postsurgical rehabilitation.

EXCEPTIONAL PRESERVATION OF SOFT TISSUES BY MICROBIAL ENTOMBMENT: INSIGHTS INTO THE TAPHONOMY OF THE CRATO KONSERVAT-LAGERSTÄTTE

Palaios ◽  
2019 ◽  
Vol 34 (7) ◽  
pp. 331-348 ◽  
Author(s):  
FILIPE G. VAREJÃO ◽  
LUCAS V. WARREN ◽  
MARCELLO G. SIMÕES ◽  
FRANZ T. FÜRSICH ◽  
SUZANA A. MATOS ◽  
...  
Keyword(s):  
Empirical Evidence ◽  
Microbial Mats ◽  
Soft Tissues ◽  
Decapod Crustaceans ◽  
Exceptional Preservation ◽  
Fossil Preservation ◽  
Taxonomic Studies ◽  
Organic Remains

ABSTRACTThe Aptian Crato Konservat-Lagerstätte is renowned for its exceptionally preserved fossils in lacustrine laminated limestones. Although previous works on this site include numerous taxonomic studies, its taphonomy remains a subject of debate. Herein, we present new data on the taphonomy of decapod crustaceans preserved in wrinkle laminites, highlighting the role of microbial mats in enhancing fossil preservation. Our results suggest that benthic microorganisms may have promoted protection and organic mineralization of some of the allochthonous to parautochthonous organic remains within the microbial laminites of the Crato lake. Overall, this work provides the first empirical evidence that the preservational pathways of the fossils in the Crato Konservat-Lagerstätte involved microbial mats.

Functional morphology of the gastric mill of the swimming crab Ovalipes trimaculatus (Decapoda: Portunidae)

2017 ◽  
Vol 98 (7) ◽  
pp. 1659-1666 ◽  
Author(s):  
Paula de La Barra ◽  
Maite Narvarte ◽  
Verónica Williner
Keyword(s):  
Complex Structure ◽  
Interspecific Variation ◽  
Alternative View ◽  
Gastric Mill ◽  
Basic Pattern ◽  
Decapod Crustaceans ◽  
Microscope Images ◽  
Portunid Crab ◽  
Stereo Microscope ◽  
Animal Component

The stomach of Decapod crustaceans is a complex structure with great interspecific variation. Several studies suggest that the anatomy of the gastric mill varies according to the diet of species in different groups. An alternative view suggests the gastric mill's structure is related to phylogenetic aspects rather than to the diet of a species. The morphology of the gastric mill of Ovalipes trimaculatus, a portunid crab target of fisheries in Argentina and Chile, was studied through stereo-microscope and scanning electron microscope images. Ovalipes trimaculatus has a stomach that corresponds to a macrophagous and predatory diet. The gastric mill is similar to that of other portunids, especially those with predominant animal component in their diet. Our results support the idea that this structure has a basic pattern, given by shape and elements forming the gastric mill; and upon that pattern, trophic habits adaptively shape certain traits.

Functional Anatomical Analysis Applied to Appliances and Kitchen Work Spaces

1979 ◽  
Vol 23 (1) ◽  
pp. 252-253
Author(s):  
Stephen W. Meagher
Keyword(s):  
Age Groups ◽  
Functional Anatomy ◽  
Essential Element ◽  
Sound Design ◽  
Design Concepts ◽  
Anatomical Analysis ◽  
Work Spaces

Functional anatomy is an essential element of sound design of kitchen appliances (Meagher, 1978) and work areas. All age groups should receive meaningful consideration of their functional needs to avoid inclusion of mechanisms of injury in design concepts whenever possible.

scholarly journals A Redescription of the Bulla, Antennae, and Mouth Parts of Female Clavella sp. (Copepoda: Siphonostomatoida: Lernaeopodidae) Infesting Wild Gadus morhua Using Scanning Electron Microscopy (SEM)

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Harry M. Murray ◽  
Jacqueline M. Hanlon ◽  
Kimberly Marshall ◽  
Corey Morris
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Gadus Morhua ◽  
Buccal Cavity ◽  
Functional Anatomy ◽  
Outer Edge ◽  
Anatomical Analysis ◽  
Gill Filaments ◽  
Scanning Electron

Many members of the Copepod family Lernaeopodidae are well-known parasites of gadids. This study reports on the occurrence of a lernaeopodid infestation of wild-sourced Gadus morhua sampled from separate inshore (Gilbert Bay, NL) and offshore (Virgin Rocks, NL) populations from Newfoundland, Canada. The majority of the parasites were observed to be associated with the buccal cavity, gill filaments, gill arch, and occasionally near the outer edge of the operculum. Anatomical analysis and detailed redescriptions of the parasite’s functional anatomy (mouth parts, antennae, and bulla complex) using high-resolution SEM indicated that the parasite was most likely of the genus Clavella. New morphological details of the second antennae ornamentation, first maxillae, bulla complex, and the oral cone are provided and discussed with regard to their potential in taxonomic applications.

Microstructural characterization of laser-melted/roller-quenched dicalcium silicate

1988 ◽  
Vol 46 ◽  
pp. 582-583
Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Shape Change ◽  
Microstructural Characterization ◽  
Particle Size Effect ◽  
Dicalcium Silicate ◽  
Laser Melting ◽  
Uniform Size ◽  
Cell Shape Change ◽  
Wide Range

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.

Actin filaments in two spermatozoa of crustacea decapoda

1990 ◽  
Vol 48 (3) ◽  
pp. 70-71
Author(s):  
E. Dupré ◽  
G. Schatten
Keyword(s):  
Electron Microscopy ◽  
Actin Filaments ◽  
Low Voltage ◽  
Active Role ◽  
Main Body ◽  
Robinson Crusoe ◽  
Decapod Crustaceans ◽  
Actual Participation ◽  
Voltage Scanning ◽  
Scanning Electron

Sperm of decapod crustaceans are formed by a round or cup-shaped body, a complex acrosome and one a few appendages emerging from the main body. Although this sperm does not have motility, it has some components of the cytoskeleton like microtubules, which are found inside the appendages. Actin filaments have been found in the spike of penaeidae sperms. The actual participation of the crustacean decapod sperm cytoskeleton during fertilization is not well understood. Actin is supposed to play an active role in drawing the penaeidae shrimp sperm closer to the egg after bending of the spike. The present study was aimed at the localization of actin filaments in sperm of the Robinson Crusoe island lobster, Jasus frontalis and in the crayfish Orconectes propincus, by fluorescent probes and low voltage scanning electron microscopy.

Analytical Electron Microscopy study of two vehicle-aged automotive exhaust catalysts having dissimilar activities

1989 ◽  
Vol 47 ◽  
pp. 272-273
Author(s):  
Sooho Kim ◽  
M. J. D’Aniello
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Noble Metal ◽  
Catalyst Deactivation ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Metal Particles ◽  
Automotive Exhaust ◽  
Exhaust Catalysts ◽  
Analytical Electron

Automotive catalysts generally lose-agtivity during vehicle operation due to several well-known deactivation mechanisms. To gain a more fundamental understanding of catalyst deactivation, the microscopic details of fresh and vehicle-aged commercial pelleted automotive exhaust catalysts containing Pt, Pd and Rh were studied by employing Analytical Electron Microscopy (AEM). Two different vehicle-aged samples containing similar poison levels but having different catalytic activities (denoted better and poorer) were selected for this study.The general microstructure of the supports and the noble metal particles of the two catalysts looks similar; the noble metal particles were generally found to be spherical and often faceted. However, the average noble metal particle size on the poorer catalyst (21 nm) was larger than that on the better catalyst (16 nm). These sizes represent a significant increase over that found on the fresh catalyst (8 nm). The activity of these catalysts decreases as the observed particle size increases.

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