Kinematics and hydrodynamics of an invertebrate undulatory swimmer: the damsel-fly larva

2002 ◽  
Vol 205 (5) ◽  
pp. 627-639 ◽  
Author(s):  
John Brackenbury
Keyword(s):  
Large Amplitude ◽  
The Body ◽  
Force Balance ◽  
The Other ◽  
Free Swimming ◽  
Caudal Fin ◽  
Fish Locomotion ◽  
Fly Larvae ◽  
Swimming Larva ◽  
Visualisation Technique

SUMMARYThe kinematics and hydrodynamics of free-swimming larvae of Enallagma cyathigerum were investigated using videography combined with a simple wake visualisation technique (tracer dyes). Damsel-fly larvae are undulatory swimmers with two distinct styles of movement: ‘slow’ swimming, in which body undulation is assisted by paddling of the legs, and ‘fast’ swimming, in which the legs are inactive. In both cases, the wake consists of discrete ring vortices shed from the caudal fin at the end of each half-stroke. The vortices propagate away from the mid-line, alternately to one side of the body then the other, at an angle of 67° from dead aft. There is no aft-flowing jet such as that observed in the wakes of continuously swimming fish that use caudal fin propulsion. The estimated momentum within the vortices, and the resultant thrust on the body are in tolerable agreement with calculations based on the large-amplitude bulk momentum model of fish locomotion. However, the drag on the body is not known, so it cannot be concluded with certainty that a force balance exists. The agreement between experiment and prediction gives confidence to the idea that most, if not all, of the vorticity generated by the swimming larva is located within the observable wake elements.

The Vortex Wake of the Free-swimming Larva and Pupa of CULEX PIPIENS (Diptera)

2001 ◽  
Vol 204 (11) ◽  
pp. 1855-1867 ◽  
Author(s):  
John Brackenbury
Keyword(s):  
Reynolds Numbers ◽  
High Amplitude ◽  
The Body ◽  
Ring Vortex ◽  
Free Swimming ◽  
Continuous Surface ◽  
The Mean ◽  
Swimming Larva ◽  
Free Swimming Larva ◽  
Visualisation Technique

SUMMARY The kinematics and hydrodynamics of free-swimming pupal and larval (final-instar) culicids were investigated using videography and a simple wake-visualisation technique (dyes). In both cases, swimming is based on a technique of high-amplitude, side-to-side (larva) or up-and-down (pupa) bending of the body. The pupa possesses a pair of plate-like abdominal paddles; the larval abdominal paddle consists of a fan of closely spaced bristles which, at the Reynolds numbers involved, behaves like a continuous surface. Wake visualisation showed that each half-stroke of the swimming cycle produces a discrete ring vortex that is convected away from the body. Consecutive vortices are produced first to one side then to the other of the mean swimming path, the convection axis being inclined at approximately 25° away from dead aft. Pupal and larval culicids therefore resemble fish in using the momentum injected into the water to generate thrust. Preliminary calculations for the pupa suggest that each vortex contains sufficient momentum to account for that added to the body with each half-stroke. The possibility is discussed that the side-to-side flexural technique may allow an interaction between body and tail flows in the production of vorticity.

II.—New Palæoniscidæ from the English Coal-Measures

1888 ◽  
Vol 5 (6) ◽  
pp. 251-254 ◽  
Author(s):  
R. H. Traquair
Keyword(s):  
The Body ◽  
The Other ◽  
Caudal Fin ◽  
Dorsal Fin ◽  
Coal Measures

Of this I have seen only two specimens. One of them, slightly longer than the other, measures 3½ inches in length up to the commencement of the caudal fin, which is deficient in both; the greatest depth of the body ½½ inch, the length of the head nearly the same. The dorsal fin is opposite the interval between the ventral and the anal; both dorsal and anal are triangular acuminate in shape, with delicate rays which at first are somewhat distantly articulated, the joints being ornamented with one or two longitudinal sulci. The pectorals are not seen in either specimen, but the smaller of the two shows a well-preserved ventral, which is pretty large, and acuminate in shape.

scholarly journals The genus Peckoltia with the description of two new species and a reanalysis of the phylogeny of the genera of the Hypostominae (Siluriformes: Loricariidae)

Zootaxa ◽  
2008 ◽  
Vol 1822 (1) ◽  
pp. 1 ◽  
Author(s):  
JONATHAN W. ARMBRUSTER
Keyword(s):  
New Species ◽  
Amazon Basin ◽  
Original Description ◽  
Color Pattern ◽  
The Body ◽  
The Other ◽  
Caudal Fin ◽  
Two New Species ◽  
Fin Spines ◽  
Pelvic Fin

Peckoltia contains 12 described species, eight of which are considered valid. Peckoltia arenaria, P. filicaudata, and P. ucayalensis are recognized as synonyms of P. bachi and P. kuhlmanni is recognized as a synonym of P. vittata. In addition, two new species are described. The type species of Peckoltichthys and Sophiancistrus are synonyms of P. bachi and both genera are recognized as junior synonyms of Peckoltia. The species of Peckoltia range throughout much of the Amazon basin, the upper Orinoco, the upper Essequibo, and perhaps the Maroni, and can be identified from most other ancistrins by having dentaries that form angle of 90° or less and from others with angled dentaries by lacking the synapomorphies of those genera. The species of Peckoltia vary from one another mostly in coloration. Peckoltia braueri, P. caenosa n. sp., P. cavatica and P. vittata lack spots on the head while the other species have them. Peckoltia braueri and P. cavatica have orange bands in the dorsal and caudal fins and have the bones and plates of the head and nape outlined in black (vs. no orange bands and head plates and bones not outlined in black in P. caenosa and P. vittata). Peckoltia caenosa has a color pattern consisting of dark vermiculations on the head and abdomen (vs. saddles or blotches on the head and faint dark spots on the abdomen in P. vittata). Among the species with spots on the head, P. lineola n. sp. and P. vermiculata have some of the spots combining to form vermiculations (vs. spots free in P. bachi, P. brevis, P. furcata, and P.oligospila) with the vermiculations larger than the pupil in P. lineola and narrower in P. vermiculata and the vermiculations radiating from a central point in P. vermiculata vs. no such pattern in P. lineola. Peckoltia bachi can be identified from the other species by having widened pelvic-fin spines that can be pulled ventrally such that they are completely ventral and parallel to the body (vs. pelvic-fin spines narrow and cannot be adducted ventral to body) and by having the eye low on the head (vs. high). Peckoltia brevis can be identified from P. furcata and P. oligospila by having well-developed dorsal saddles (vs. saddles faint), no spots on the body behind the nape (vs. spots generally present behind the nape); from P. oligospila by having bands in the caudal fin (vs. spots); and from P. furcata by having the lower caudal-fin spine longer than the upper (vs. upper spine longer). Peckoltia furcata can be identified from P. oligospila by having the upper caudal-fin spine longer than the lower (vs. lower spine longer) and by having bands in the caudal fin (vs. spots). Ancistrus yaravi had been recognized as a species of Peckoltia. The type of A. yaravi is lost, but the original description suggests that the species is the senior synonym of Neblinichthys roraima. A revised morphological phylogeny demonstrates the lack of support for Peckoltia and Hemiancistrus as monophyletic, and phenetic definitions are provided for the two genera. The phylogeny also demonstrates a lack of support of the genus Watawata.

Memoirs: The Reproductive System and Associated Organs of the Brittle-Star Ophiothrix Fragilis

1940 ◽  
Vol s2-82 (326) ◽  
pp. 267-309
Author(s):  
J. B. SMITH
Keyword(s):  
Breeding Season ◽  
Reproductive System ◽  
Body Wall ◽  
The Body ◽  
The Other ◽  
Larval Life ◽  
Free Swimming ◽  
Axial Organ ◽  
The Right ◽  
Stone Canal

1. The organs associated, either directly or indirectly, with reproduction in the Ophiuroidea are the axial organ and related sinuses (axial organ complex), the genital raehis, the gonads (localized expansions of the raehis), the gonoducts, and the genital bursae. 2. Evidence is presented in favour of the view of Fedotov (1924) that the axial organ of Ophiuroids is made up of two closely associated parts each surrounded by its own sinus from the wall of which it is, during development, proliferated. The left axial sinus (aboral in the adult) is derived from the left anterior coelom of the larva, the right axial sinus (oral in the adult) from the madreporie vesicle which itself is a derivative of the right anterior coelom of the larva. 3. The ampulla of the stone canal is continuous with, and is part of, the left axial sinus. 4. An account is given of the morphology and histology of the genital rachis and sinus. 5. Examination of the gonads of female Ophiothrix indicate that the breeding season extends from about March to October and that, during this time, there is periodic emission of ova, probably at monthly intervals. Males, on the other hand, produce sperm all the year round. 6. The genital bursae number two pairs to each interradial pouch. They serve, primarily, as organs of respiration. Special mechanisms, which are described, are concerned in the intake and expulsion of water. 7. The gonads do not discharge their products directly into the genital bursae nor through temporarily formed pores in the body-wall but through specially developed and permanent gonoducts, one to each of the ten gonads. 8. Young specimens found in the genital bursae have attained their position only after a period of free-swimming larval life. After settling and metamorphosing, some of the young individuals crawl into the bursae. 9. As a consequence of the previous observation it is pointed out that the presence of the young within the genital bursae of the adult is by no means an indication of a viviparous habit.

Calcium accumulation and secretion in the serpulid polychaete Spirorbis spirorbis L. at settlement

1975 ◽  
Vol 55 (4) ◽  
pp. 911-923 ◽  
Author(s):  
J. A. Nott ◽  
K. R. Parkes
Keyword(s):  
Sea Water ◽  
The Body ◽  
Posterior Half ◽  
Free Swimming ◽  
Calcium Accumulation ◽  
Material Forming ◽  
Suitable Substratum ◽  
Swimming Larva ◽  
Free Swimming Larva

When the free-swimming larva of the polychaete tubeworm Spirorbis spirorbis settles permanently on a suitable substratum, it forms a thin, mucous, anchoring tube, which covers only the posterior half of the body. Within 3 h the worm has built a comparatively thick, calcareous tube onto the anterior end of the initial, mucous tube, which later becomes a compressed and folded remnant (Nott, 1973). The volume of calcareous material forming the tube cannot be stored within the body of the larva before settlement and must, therefore, be taken up rapidly from sea water or ingested material.

High Heels sebagai Agensi bagi Tubuh Wanita

2020 ◽  
Vol 5 (2) ◽  
pp. 196
Author(s):  
Sunandar Macpal ◽  
Fathianabilla Azhar
Keyword(s):  
Body Image ◽  
Literature Review ◽  
The Body ◽  
The Other ◽  
Body Image Disturbance ◽  
Other Hand ◽  
High Heels ◽  
Experience Pain ◽  
Woman's Body

The aims of this paper is to explain the use of high heels as an agency for a woman's body. Agency context refers to pain in the body but pain is perceived as something positive. In this paper, the method used is a literature review by reviewing writings related to the use of high heels. The findings in this paper that women experience body image disturbance or anxiety because they feel themselves are not beautiful or not attractive. The use of high heels, makes women more attractive and more confident, on the other hand the use of high heels actually makes women feel pain and discomfort. However, for the achievement of beauty standards, women voluntarily allow their bodies to experience pain. However, the agency's willingness to beauty standards here is meaningless without filtering and directly accepted. Instead women keep negotiating with themselves so as to make a decision why use high heels.

EXPRESSION OF SOME IMMUNOLOGIC MARKERS FOR THE DIAGNOSIS OF SUSPECTED LYMPHOID LESIONS OF LYMPHOMA

2018 ◽  
Vol 8 (4) ◽  
pp. 28-33
Author(s):  
Mao Nguyen Van ◽  
Thao Le Thi Thu
Keyword(s):  
Correct Diagnosis ◽  
Tumour Cells ◽  
The Body ◽  
The Other ◽  
Cervical Region ◽  
Cross Sectional ◽  
Immunologic Markers ◽  
Microscopic Features ◽  
Poor Differentiation ◽  
Benign Tumours

Background: In practice it was difficult or impossible to have a correct diagnosis for the lymphoid proliferation lesions based on only H.E standard histopathology. In addition to histopathology, the application of immunohistochemistry was indispensable for the definitive diagnosis of the malignant or benign tumours and the origin of the tumour cells as well. Objectives: 1. To describe the gross and microscopic features of the suspected lesions of lymphoma; 2. To asses the expression of some immunologic markers for the diagnosis and classification of the suspected lesions of lymphoma. Materials and Method: Cross-sectional research on 81 patients diagnosed by histopathology as lymphomas or suspected lesions of lymphoma, following with immunohistopathology staining of 6 main markers including LCA, CD3, CD20, Bcl2, CD30 and AE1/3. Results: The most site was lymph node 58.1% which appeared at cervical region 72.3%, then the stomach 14.9% and small intestine 12.4%. The other sites in the body were met with lower frequency. Histopathologically, the most type of the lesions was atypical hyperplasia of the lymphoid tissue suspecting the lymphomas 49.4%, lymphomas 34.5%, the other diagnoses were lower including inflammation, poor differentiation carcinoam not excluding the lymphomas, lymphomas differentiating with poor differentiation carcinomas. Immunohistochemistry showed that, LCA, CD3, CD20, Bcl2, CD30 and AE1/3 were all positive depending on such type of tumours. The real lymphomas were 48/81 cases (59.3%), benign ones 35.8% and poor differentiated carcinomas 4.9%. Conclusion: Immunohistochemistry with 6 markers could help to diagnose correctly as benign or malignant lesions, classify and determine the origin of the tumour cells as lymphocytes or epithelial cells diagnosed by histopathology as lymphomas or suspected lesions of lymphomas. Key words: histopathology, immunohistochemistry, lymphomas, poor differentiated carcinomas, hyperplasia, atypicality

Basic Concepts and Definitions of Allergology

2019 ◽  
Author(s):  
Zoran Vrucinic
Keyword(s):  
Immune Reaction ◽  
The Body ◽  
The Other ◽  
Specific Response ◽  
Other Hand ◽  
Medical Vocabulary ◽  
The Future ◽  
Basic Concepts ◽  
Basic Insight ◽  
Insight Into

The future of medicine belongs to immunology and alergology. I tried to not be too wide in description, but on the other hand to mention the most important concepts of alergology to make access to these diseases more understandable, logical and more useful for our patients, that without complex pathophysiology and mechanism of immune reaction,we gain some basic insight into immunological principles. The name allergy to medicine was introduced by Pirquet in 1906, and is of Greek origin (allos-other + ergon-act; different reaction), essentially representing the reaction of an organism to a substance that has already been in contact with it, and manifested as a specific response thatmanifests as either a heightened reaction, a hypersensitivity, or as a reduced reaction immunity. Synonyms for hypersensitivity are: altered reactivity, reaction, hypersensitivity. The word sensitization comes from the Latin (sensibilitas, atis, f.), which means sensibility,sensitivity, and has retained that meaning in medical vocabulary, while in immunology and allergology this term implies the creation of hypersensitivity to an antigen. Antigen comes from the Greek words, anti-anti + genos-genus, the opposite, anti-substance substance that causes the body to produce antibodies.

Body and Soul

2017 ◽  
Author(s):  
Isabella Image
Keyword(s):  
Human Person ◽  
Fourth Century ◽  
The Body ◽  
The Other ◽  
Spiritual Nature ◽  
Body And Soul ◽  
Century Thought

This chapter discusses Hilary’s dichotomous body–soul anthropology. Although past scholars have tried to categorize Hilary as ‘Platonic’ or ‘Stoic’, these categories do not fully summarize fourth-century thought, not least because two-way as well as three-way expressions of the human person are also found in Scripture. The influence of Origen is demonstrated with particular reference to the commentary on Ps. 118.73, informed by parallels in Ambrose and the Palestinian Catena. As a result, it is possible to ascribe differences between Hilary’s commentaries to the fact that one is more reliant on Origen than the other. Nevertheless, Hilary’s position always seems to be that the body and soul should be at harmony until the body takes on the spiritual nature of the soul.

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