On the Habits and Adaptations of Aloidis (Corbula) Gibba

1946 ◽  
Vol 26 (3) ◽  
pp. 358-376 ◽  
Author(s):  
C. M. Yonge
Keyword(s):  
Great Reduction ◽  
Inorganic Material ◽  
Left Valve ◽  
Byssus Thread ◽  
Adductor Muscles ◽  
Inhalant Siphon ◽  
The Asymmetry ◽  
The Right ◽  
Marginal Region

1. Aloidis (Corbula) gibba is a eulamellibranch specialized for life in muddy gravel substrata to depths of up to about 80 fathoms.2. The shell is asymmetrical, the margin of the smaller, left valve being uncalcified and so fitting within the marginal region of the right valve. A possible manner in which this asymmetry is produced by the differential secretory activities of the two mantle edges is discussed.3. The marginal periostracum of the left valve has strengthening calcined regions posteriorly, probably to protect the siphons when extruded.4. The external ligament is reduced and the resilium condensed, possibly permitting some antero-posterior rocking of the shell valves when the adductors contract.5. The process of burrowing is described; on its completion the animal is anchored by a single byssus thread.6. The siphons are very short, the tentacles of the siphonal sheath lying on the surface of the substratum. The inhalant siphon is wide and relatively insensitive; it draws in much bottom material. The exhalant siphon is tubular and very sensitive. It is controlled by two paired bands of muscle.7. The great quantities of pseudo-faeces which accumulate are expelled by periodical contractions of the 'quick' portions of the adductor muscles, the asymmetry of the shell valves causing great reduction in the size of the inhalant chamber. The foot may also assist in clearing the chamber. 8. The large ctenidia create a very powerful current; they are adapted for dealing with large amounts of sediment by means of specialized terminal, guarding and cirrus-like cilia. Control of 'pumping' is primarily by means of the exhalant siphon.9. The stomach is large in correlation with the great amounts of inorganic material carried in with the food.

Comparison of the efficiency of the indexes of Pont and Korkhause with Kernott technique in patients with narrowing of maxilla

2020 ◽  
Vol 20 (3) ◽  
pp. 199-203
Author(s):  
O. I. Admakin ◽  
I. A. Solop ◽  
A. D. Oksentyuk
Keyword(s):  
Dental Treatment ◽  
Standard Analysis ◽  
Clinical Hospital ◽  
Control Models ◽  
Diagnostic Models ◽  
Left And Right ◽  
The Asymmetry ◽  
The Right ◽  
The University ◽  
Medical University

Relevance. The narrowing of the maxilla is one of the most common pathologies in orthodontics. Recent studies show that the narrowing is always asymmetric which is connected to the rotation of the maxilla. To choose the treatment correctly one need a calculation that reveals the asymmetry, which is impossible with using standard indexes.Purpose – to compare efficiency of indexes of Pont and Korkhause with the Kernott's method in patients with narrowing of the maxilla.Materials and methods. The study involved 35 children aged from 8 to 12 years old undergoing dental treatment in the University Children's Clinical Hospital of the First Moscow State Medical University with no comorbidities. For every patient a gypsum model was prepared and after that to carry out the biometrical calculation. In this study two indexes were used: Pont's index and Korkhause's; using this standard analysis the narrowing of the maxilla was revealed. After using Pont's Index and Korkhaus analysis all the models were calculated by the method of Kernott with Kernott's dynamic pentagon.Results. As a result of the analysis of the control diagnostic models a narrowing of the maxilla in 69% of cases (n = 24) was revealed in all cases, the deviation of the size of the dentition was asymmetric. Thus, 65% of the surveyed models showed a narrowing on the right. This narrowing was of a different severity and averaged 15 control models.Conclusions. This shows that for the biometrics of diagnostic models it is necessary to use methods that allow to estimate the width of the dentition rows on the left and on the right separately. To correct the asymmetric narrowing of the dentition, it is preferable to use non-classical expanding devices that act equally on the left and right sides separetly.

scholarly journals Marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation of four finish line locations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Keunbada Son ◽  
Young-Tak Son ◽  
Ji-Min Lee ◽  
Kyu-Bok Lee
Keyword(s):  
Three Dimensional ◽  
Clinical Situation ◽  
Intraoral Scanner ◽  
Replica Technique ◽  
Finish Line ◽  
Marginal Fit ◽  
Tooth Preparation ◽  
The Right ◽  
Internal Fit ◽  
Marginal Region

AbstractThis study evaluated the marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation scanned at four finish line locations. The right maxillary first molar tooth preparation model was fabricated using a ceramic material and placed in four finish line locations (supragingival, equigingival, subgingival, and subgingival with a cord). Intraoral scanning was performed. Crowns were designed based on the scanned area. Interim crowns were fabricated using a stereolithography three-dimensional (3D) printer (N = 16 per location). Marginal and internal fit were evaluated with a silicone replica technique. Intaglio surface trueness was evaluated using a 3D inspection software. One-way analysis of variance and Tukey HSD test were performed for comparisons (α = 0.05). The marginal and internal fit showed significant differences according to locations (P < 0.05); the marginal fit showed the best results in the supragingival finish line (P < 0.05). Intaglio surface trueness was significantly different in the marginal region, with the highest value in the subgingival location (P < 0.05). Crowns fabricated on the subgingival finish line caused inaccurate marginal fit due to poor fabrication reproducibility of the marginal region. The use of an intraoral scanner should be decided on the clinical situation and needs.

Comparison of Bone-Conducted Vibration for Eliciting Ocular Vestibular-Evoked Myogenic Potentials

2011 ◽  
Vol 146 (2) ◽  
pp. 289-294 ◽  
Author(s):  
Chia-Chen Tseng ◽  
Shou-Jen Wang ◽  
Yi-Ho Young
Keyword(s):  
Prospective Study ◽  
Study Design ◽  
Healthy Subjects ◽  
University Hospital ◽  
Vestibular Evoked Myogenic Potentials ◽  
Ménière’S Disease ◽  
Asymmetry Ratio ◽  
Significant Difference ◽  
The Asymmetry ◽  
The Right

Objective. This study compared bone-conducted vibration (BCV) stimuli at forehead (Fz) and mastoid sites for eliciting ocular vestibular-evoked myogenic potentials (oVEMPs). Study Design. Prospective study. Setting. University hospital. Methods. Twenty healthy subjects underwent oVEMP testing via BCV stimuli at Fz and mastoid sites. Another 50 patients with unilateral Meniere’s disease also underwent oVEMP testing. Results. All healthy subjects showed clear oVEMPs via BCV stimulation regardless of the tapping sites. The right oVEMPs stimulated by tapping at the right mastoid had earlier nI and pI latencies and a larger nI-pI amplitude compared with those stimulated by tapping at the Fz and left mastoid. Similar trends were also observed in left oVEMPs. However, the asymmetry ratio did not differ significantly between the ipsilateral mastoid and Fz sites. Clinically, tapping at the Fz revealed absent oVEMPs in 28% of Meniere’s ears, which decreased to 16% when tapping at the ipsilesional (hydropic) mastoid site, exhibiting a significant difference. Conclusion. Tapping at the ipsilateral mastoid site elicits earlier oVEMP latencies and larger oVEMP amplitudes when compared with tapping at the Fz site. Thus, tapping at the Fz site is suggested to screen for the otolithic function, whereas tapping at the ipsilesional mastoid site is suitable for evaluating residual otolithic function.

Geographical review of the ostracod genus Vestalenula (Darwinulidae) and a new subterranean species from southern France

2007 ◽  
Vol 21 (5) ◽  
pp. 471 ◽  
Author(s):  
Malvina Artheau
Keyword(s):  
New Record ◽  
Cladistic Analysis ◽  
Left Valve ◽  
Southern France ◽  
Recent Species ◽  
European Program ◽  
The Right ◽  
Subterranean Species ◽  
A New Species ◽  
Subterranean Environment

A new species of Vestalenula is described. Vestalenula carveli, sp. nov. was found in the interstitial habitat of rivers during the PASCALIS European program when sampling three sites on the Aude River and Tech River basins (Roussillon region, southern France). With its large caudal brooding cavity, the presence of an external keel on the right valve and an internal tooth on the left valve, V. carveli is a typical representative of the genus. This new record brings the worldwide number of Vestalenula species to 24. Vestalenula representatives are known from the Lower Miocene to the present. A review of present-day knowledge of the geographical distribution of the genus and a cladistic analysis are presented in order to assess the biogeography of this genus and the importance of the discovery of a new subterranean species in southern France. The geographical review of the genus showed that most species of Vestalenula occur in subtropical regions. However, V. cylindrica, V. boteai and V. danielopoli lived, or are living, in the Palearctic. Vestalenula pagliolii occurs in both hemispheres. Many of the Recent species live in semiterrestrial and/or interstitial habitats and occur in geographically restricted areas. The distribution of the species of Vestalenula suggests independent colonisation of the subterranean environment by several species; this hypothesis is supported by the cladistic analysis.

Handedness affects Emotional Valence Asymmetry

1989 ◽  
Vol 68 (2) ◽  
pp. 435-441 ◽  
Author(s):  
Richard A. McFarland ◽  
Robert Kennison
Keyword(s):  
Negative Affect ◽  
Hemispheric Asymmetry ◽  
Emotional Responses ◽  
Emotional Valence ◽  
Left Handed ◽  
Two Factors ◽  
Left And Right ◽  
The Asymmetry ◽  
The Right ◽  
Cerebral Processing

Music was played monaurally to 80 right-handed and 80 left-handed subjects. Right-handers reported more positive and less negative affect if the music was to the right ear. Left-handers reported experiencing more positive and less negative affect during music to the left ear. The hand × ear interaction was significant. The valence of emotional responses to the music seems influenced by a combination of at least two factors, (1) differences between left- and right-handers in the cerebral processing of emotional valence and (2) differences in the processing of emotional valence within each handedness group depending upon which hemisphere was initially most strongly engaged by the music. These results partially corroborate and extend the findings of previous studies in which briefer stimuli were presented tachistoscopically or dichotically. It is concluded that, while there is hemispheric asymmetry in the processing of emotional valence, the direction of the asymmetry may be associated with the handedness of the subjects.

scholarly journals The Generative Organs of the Oyster

1890 ◽  
Vol 1 (3) ◽  
pp. 268-281 ◽  
Author(s):  
Gilbert C. Bourne
Keyword(s):  
Adductor Muscle ◽  
Reproductive Organs ◽  
Posterior Surface ◽  
Anterior Surface ◽  
Left Valve ◽  
Left Hand ◽  
Natural Position ◽  
The Right ◽  
Ventral Border ◽  
Generative Organs

The following description of the reproductive organs of the oyster cannot well be understood without some acquaintance with the general anatomy of the animal. With the help of Pl. XXII, fig. 1, the most important features of its anatomy may readily be understood. It must be remembered that the valves of the oyster's shell lie right and left of the animal; that the concave valve which lies undermost in the natural position of the animal is the left valve, and the flat upper valve is the right valve. The hinge marks the dorsal border of the animal, and the opposite border is the ventral border. That side which is on the observer's right in fig. 1 is the anterior surface, and that on the left hand is the posterior surface. As the animal is compressed from side to side the anterior and posterior surfaces are very narrow. The great adductor muscle, by which the valves of the shell are closed, is seen lying in the centre of the animal in fig. 1.

Intermezzo or What Exists When a Tree Exists?

2016 ◽  
Author(s):  
Andrea Moro
Keyword(s):  
Formal Representation ◽  
Constituent Structure ◽  
The Asymmetry ◽  
The Right ◽  
Formal Representations

It is sometimes assumed that formal representation of language are abstractions and that they contrast with the concreteness of empirical neurobiological measures. It is argued that this is not so and that, moreover, the formal representations adopted in linguistics are also detectable by providing the right stimulus to the subjects at the neurobiological level; one example is given by the asymmetry of constituent structure.

A new genus Turneroconcha (Bivalvia: Vesicomyidae: Pliocardiinae) for the giant hydrothermal vent clam ‘Calyptogena’ magnifica

Zootaxa ◽  
2020 ◽  
Vol 4808 (1) ◽  
pp. 79-100 ◽  
Author(s):  
ELENA M. KRYLOVA ◽  
HEIKO SAHLING
Keyword(s):  
Morphological Analysis ◽  
New Genus ◽  
Posterior Part ◽  
Morphological Characters ◽  
Morphological Data ◽  
Monotypic Genus ◽  
East Pacific ◽  
Inhalant Siphon ◽  
The Right ◽  
Galapagos Rift

A new monotypic genus, Turneroconcha, is established for T. magnifica (Boss & Turner) which was originally assigned to the genus Calyptogena Dall. The distinguishing morphological characters of the new genus are the combination of both conchological and anatomical features including: the presence of only two tooth elements in the right valve; submerged location of the posterior part of the posterior lamellar ligament layer; the absence of a subumbonal pit, lunular incision, escutcheon and pallial sinus; the presence of both pairs of demibranchs; the tubular structure of marginal parts of the interlamellar septa in gills; an inner valve of the inhalant siphon without processes; tentaculate inner mantle fold 3 and a Z-shaped digestive tract. Analysis of morphological data on Recent and fossil pliocardiines shows that Turneroconcha gen. nov. can be presently considered as a monotypic genus. The comparative morphological analysis of the new genus with described pliocardiine genera is consistent with available molecular results. Turneroconcha gen. nov. is endemic to the East-Pacific Rise and Galapagos Rift and occurs at water depths of 2251 to 2791 m. It is the only pliocardiine genus known so far with a mainly epifaunal life habit. No fossils of Turneroconcha gen. nov. are known.  

scholarly journals Punishment, Property, and the Limits of Altruism: Locke's International Asymmetry

2008 ◽  
Vol 102 (4) ◽  
pp. 467-479 ◽  
Author(s):  
ALEX TUCKNESS
Keyword(s):  
The State ◽  
Standard Interpretation ◽  
State Of Nature ◽  
Functional Equivalent ◽  
The Asymmetry ◽  
The Right

The standard interpretation of Locke assumes symmetry between punishment by individuals in the state of nature and punishment by states in the state of nature. The standard interpretation is incorrect because in cases where the punishment is altruistic, the state is not the functional equivalent of a person, having a more restricted power to punish. The asymmetry arises from Locke's contractualism because individuals in the state of nature might reasonably refuse to give governments the power to punish altruistically. This interpretation clarifies some ongoing puzzles about Locke's theory of property where questions about coerced sacrifices to benefit others also arise. Locke's argument is vulnerable to important objections, specifically that he equivocates on the meaning of the word “body,” that he places too much emphasis on the right of self-preservation, and that he legitimates nearly unlimited appropriation by states.

The mechanism of boring in Zirphaea crispata (L.) (Bivalvia: Pholadidae)

1968 ◽  
Vol 170 (1019) ◽  
pp. 155-173 ◽  
Keyword(s):  
Adductor Muscle ◽  
Mantle Cavity ◽  
Clockwise Rotation ◽  
Mantle Tissue ◽  
Counter Pressure ◽  
Time Period ◽  
Adductor Muscles ◽  
Inhalant Siphon ◽  
Main Activity ◽  
Low Pressures

The main activity during boring by Zirphaea crispata consists of the cyclical repetition of a group of movements, termed the boring cycle. Each boring cycle comprises the retraction of the shell to the base of the burrow, and the abrasion of the walls of the burrow by movements of the shell caused by the consecutive action of the posterior and anterior adductor muscles, supplemented by an accessory ventral adductor muscle. Each boring cycle is followed by slight anticlockwise and clockwise rotation of the animal in the burrow, while simultaneously the siphons are withdrawn and re-extended. A second type of rotational movement, resulting from changes in the position of the foot in the burrow, occurs over a longer time period, so that a circular, drop-shaped burrow is formed. The material abraded from the base of the burrow is collected into the mantle cavity and ejected as pseudofaeces from the inhalant siphon at intervals during boring. The pressures developed in the mantle cavity and haemocoele during boring are small compared with those generated by burrowing forms. During the boring cycle, low pressures (2 to 3 cm) serve to press the foot against the wall of the burrow where adhesion is aided by mucous secretion and by the action of a counter pressure from a pad of mantle tissue dorsally. Fluid is retained in the foot, and in the expanded mantle margins within the spaces of a loosely arranged connective tissue which fills these organs. The fluid filled mantle cavity and haemocoele allow the siphonal retractor muscles to act partly in antagonizing the adductor muscles, so that withdrawal of the siphons during boring restores the gape of the shell. Higher pressures (8 cm) are developed in the mantle cavity and haemocoele during the contraction of the adductor muscles and circular muscles of the siphons which is involved in the expulsion of pseudo-faeces. The tensions exerted by the pedal muscles during boring are small (2 to 2·5 g).

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