The fine structure and function of the cephalic appendages of the branchiuran parasite, Argulus japonicus Thiele

1993 ◽  
Vol 339 (1287) ◽  
pp. 119-135 ◽  
Keyword(s):  
Light And Electron Microscopy ◽  
The Body ◽  
Fish Parasite ◽  
Suboesophageal Ganglion ◽  
In The Wild ◽  
Mouth Tube ◽  
Muscle Groups ◽  
Fine Structure And Function ◽  
And Function ◽  
Thickened Cuticle

The fish parasite Argulus japonicus Thiele (Crustacea: Branchiura) has recently been introduced into Britain and is now established in the wild. A. japonicus , an ectoparasite attaching to, and feeding on, the skin of its host, is a potentially serious pathogen of native freshwater fishes. The anatomy of the attachment and feeding structures is described using light and electron microscopy. The primary attachment organs are the suckers derived from the maxillules. The extrinsic musculature of the suckers comprises two major muscle groups: the suction muscles which insert on the floor of the sucker and generate suction, and the cup muscles which control the orientation and movement of the sucker as a whole. The inner wall of the sucker cup comprises two hoops of thickened cuticle and provides the rigidity necessary to prevent the sucker from collapsing. These hoops are hinged to allow extra movement of the distal hoop plus its marginal m em brane when forming a seal onto the surface of the host. Numerous mucous glands are present in the floor of the sucker. The elongate mouth tube represents a ventral outgrowth of the head bearing a small labrum and labium distally. The homology of the labium is confirmed by the arrangement of its paired muscles, which originate on the undersurface of the ventral cephalic tendon and pass down through channels in the suboesophageal ganglion. The labrum lacks muscles. The ontogeny of the mouth tube, the adult m andibular musculature and the possible feeding mechanism are described. The preoral spine lies in the ventral midline of the body anterior to the mouth tube. It consists of a tapering spine carried on a long eversible sheath. When fully retracted the spine and sheath virtually disappear into the body. As the spine retracts the cuticle of the proximal sheath becomes inverted. The epithelium beneath this sheath cuticle is syncytial and is separated from the cuticle-lined, central duct of the spine by a fluid matrix which can be displaced as the spine is retracted. The fluid matrix appears to be secreted by the epithelial cells of the sheath cuticle. Retraction is by means of paired retractor muscles which originate dorsal to the midgut and pass down through the nerve ring. These muscles shorten to about 25% of their maximum length during extreme retraction.

scholarly journals Fine Structure and Function in Stentor polymorphus

1958 ◽  
Vol 4 (6) ◽  
pp. 807-830 ◽  
Author(s):  
J. T. Randall ◽  
Sylvia Fitton Jackson
Keyword(s):  
Fine Structure ◽  
Living Organism ◽  
Structural Features ◽  
The Body ◽  
Interconnected System ◽  
Fine Structure And Function ◽  
The Individual ◽  
And Function ◽  
Theoretical Considerations ◽  
Vacuolated Cytoplasm

The fine structure of the ciliate Stentor has been studied by means of the electron microscope and the results have been correlated with observations made on the living organism by means of light microscopy; special reference has been made to structural features which may be responsible for contraction and extension in Stentor. Descriptions have been given of the structure of the macronucleus, the vacuolated cytoplasm, mitochondria and the pellicle; a detailed study has also been made of the adoral membranelles. About 250 membranelles encircle the peristomal cap and each is composed of 3 rows of cilia, with 20 to 25 cilia in each row; a fibrillar root system connected with the membranelles depends into the endoplasm for about 20 µ and each is essentially in the shape of a fan, the terminal ends of each root bifurcating to connect to neighbouring roots. The membranelles thus form a cohesive unit and this morphological arrangement may have a bearing on the motion and coordination of the whole system. Two structural features extending throughout the length of the animal have been identified per cortical stripe in the body wall of Stentor; first, km fibres lying just beneath the pellicle are composed of stacks of fibrillar sheets and are identical with the birefringent fibres observed in the living animal. The individual fibrils of the sheets are in turn connected to the kinetosomes of the body cilia; thus the km fibres are homologous to kinetodesmata. Secondly, M bands lie beneath the km fibres and form an interconnected system in contact with the surrounding vacuolated cytoplasm; the thickness of the M bands is greatest at the base of a contracted animal. The contractile and extensile properties of these organelles have been discussed in the light of experimental results and theoretical considerations.

scholarly journals THE FINE STRUCTURE AND FUNCTION OF THE TENTACLE IN TOKOPHRYA INFUSIONUM

1965 ◽  
Vol 25 (3) ◽  
pp. 459-477 ◽  
Author(s):  
Maria A. Rudzinska
Keyword(s):  
Electron Microscope Study ◽  
Structure And Function ◽  
The Body ◽  
Feeding Apparatus ◽  
Dense Bodies ◽  
Structural Details ◽  
Flow Through ◽  
Feeding Process ◽  
Fine Structure And Function ◽  
And Function

The feeding apparatus of Suctoria consists of long, thin, stiff tubes called tentacles. When a swimming prey attaches to the tip of the tentacle a number of events follow in rapid succession. The tentacle broadens, a stream of tiny granules starts to move upward at its periphery to the tip, the prey becomes immobilized and shortly thereafter the cytoplasm of the still living prey begins to flow through the center of the tentacle to the body of the predator. An electron microscope study of the tentacle in Tokophrya infusionum, a protozoan of the subclass Suctoria, has disclosed a number of structural details which help to clarify some of the mechanisms involved in this unusual way of feeding. Each tentacle is composed of two concentric tubes. The lumen of the inner tube is surrounded by 49 tubular fibrils most probably of contractile nature. In the inner tube the cytoplasm of the prey is present during feeding, and in the outer tube are small dense bodies. It was found that the dense bodies originate in the cytoplasm of Tokophrya. They have an elongate, missile-like appearance, pointed at one end, rounded at the other, and are composed of several distinct segments. At the tip of the tentacle they penetrate the plasma membrane, with their pointed ends sticking out. It is assumed that the missile-like bodies play a major role in the feeding process. Their composite structure suggests that they might contain a number of enzymes which most probably are responsible for the various events preceding the actual food intake.

Influence of Ascorbic Acid on the Structure and Function of Alpha-2- macroglobulin: Investigations using Spectroscopic and Thermodynamic Techniques

2020 ◽  
Vol 27 (3) ◽  
pp. 201-209
Author(s):  
Syed Saqib Ali ◽  
Mohammad Khalid Zia ◽  
Tooba Siddiqui ◽  
Haseeb Ahsan ◽  
Fahim Halim Khan
Keyword(s):  
Ascorbic Acid ◽  
Conformational Changes ◽  
Structural Changes ◽  
The Body ◽  
Titration Calorimetry ◽  
Spectroscopic Techniques ◽  
Human Beings ◽  
Plasma Ascorbic Acid ◽  
Dietary Antioxidant ◽  
And Function

Background: Ascorbic acid is a classic dietary antioxidant which plays an important role in the body of human beings. It is commonly found in various foods as well as taken as dietary supplement. Objective: The plasma ascorbic acid concentration may range from low, as in chronic or acute oxidative stress to high if delivered intravenously during cancer treatment. Sheep alpha-2- macroglobulin (α2M), a human α2M homologue is a large tetrameric glycoprotein of 630 kDa with antiproteinase activity, found in sheep’s blood. Methods: In the present study, the interaction of ascorbic acid with alpha-2-macroglobulin was explored in the presence of visible light by utilizing various spectroscopic techniques and isothermal titration calorimetry (ITC). Results: UV-vis and fluorescence spectroscopy suggests the formation of a complex between ascorbic acid and α2M apparent by increased absorbance and decreased fluorescence. Secondary structural changes in the α2M were investigated by CD and FT-IR spectroscopy. Our findings suggest the induction of subtle conformational changes in α2M induced by ascorbic acid. Thermodynamics signatures of ascorbic acid and α2M interaction indicate that the binding is an enthalpy-driven process. Conclusion: It is possible that ascorbic acid binds and compromises antiproteinase activity of α2M by inducing changes in the secondary structure of the protein.

A Guide to Old Spanish

2018 ◽  
Author(s):  
Steven N. Dworkin
Keyword(s):  
The Body ◽  
Standard Language ◽  
Function Words ◽  
Sound System ◽  
Old Spanish ◽  
And Function ◽  
Linguistic Structures ◽  
Verb Tense ◽  
Modern Standard

This book describes the linguistic structures that constitute Medieval or Old Spanish as preserved in texts written prior to the beginning of the sixteenth century. It emphasizes those structures that contrast with the modern standard language. Chapter 1 presents methodological issues raised by the study of a language preserved only in written sources. Chapter 2 examines questions involved in reconstructing the sound system of Old Spanish before discussing relevant phonetic and phonological details. The chapter ends with an overview of Old Spanish spelling practices. Chapter 3 presents in some detail the nominal, verbal, and pronominal morphology of the language, with attention to regional variants. Chapter 4 describes selected syntactic structures, with emphasis on the noun phrase, verb phrase, object pronoun placement, subject-verb-object word order, verb tense, aspect, and mood. Chapter 5 begins with an extensive list of Old Spanish nouns, adjectives, verbs, and function words that have not survived into the modern standard language. It then presents examples of coexisting variants (doublets) and changes of meaning, and finishes with an overview of the creation of neologisms in the medieval language through derivational morphology (prefixation, suffixation, compounding). The book concludes with an anthology composed of three extracts from Spanish prose texts, one each from the thirteenth, fourteenth, and fifteenth centuries. The extracts contain footnotes that highlight relevant morphological, syntactic, and lexical features, with cross references to the relevant sections in the body of the book.

The internal anatomy of the woodlouse, Metoponorthus pruinosus (Brandt), (Porcellionidae, Peracarida)

1968 ◽  
Vol 46 (3) ◽  
pp. 321-327 ◽  
Author(s):  
M. A. Alikhan
Keyword(s):  
Nervous System ◽  
Digestive System ◽  
Circulatory System ◽  
Reproductive Organs ◽  
The Body ◽  
Internal Anatomy ◽  
Suboesophageal Ganglion ◽  
Digestive Tube ◽  
Thoracic Ganglia ◽  
Digestive Glands

Tbe circulatory system, lying in the mid-dorsal line of the body, consists of an oval heart, the opthalmic artery, and a dorsal abdominal artery.The digestive system comprises a wide, large alimentary tube and two pairs of digestive glands. An oesophagus, a proventriculus, midgut, and a short proctodacum or hindgut form the digestive tube. The digestive glands are very well developed and are beaded in form; each pair lies on either side of the alimentary canal.The reproductive organs are well developed in both sexes: in the male they consist of paired testes and their vas deferentia, and in the female paired bilobed ovaries and oviducts.A cerebral or supraoesophageal ganglion, a suboesophageal ganglion, and seven thoracic ganglia form the nervous system. The supraoesophageal ganglion is united with the suboesophageal ganglion by means of the circumoesophageal commissures, whereas the thoracic ganglia and suboesophageal ganglia are linked with each other by paired connectives.The gills and the tracheae are the organs of respiration. The gills are borne of the bases of the pleopods and are enclosed in the branchial chamber. The tracheae are located on the lateral lobes of the first two pleopods only.

scholarly journals Does Motor Training of the Nonparetic Side Influences Balance and Function in Chronic Stroke? A Pilot RCT

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shanta Pandian ◽  
Kamal Narayan Arya ◽  
Dharmendra Kumar
Keyword(s):  
Functional Performance ◽  
Berg Balance Scale ◽  
Chronic Stroke ◽  
The Body ◽  
Control Group ◽  
Therapy Program ◽  
Functional Reach Test ◽  
Double Blinded ◽  
And Function ◽  
Experimental Group

Background. Balance and functional abilities are controlled by both sides of the body. The role of nonparetic side has never been explored for such skills.Objective. The objective of the present study was to examine the effect of a motor therapy program primarily involving the nonparetic side on balance and function in chronic stroke.Method. A randomized controlled, double blinded trial was conducted on 39 poststroke hemiparetic subjects (21, men; mean age, 42 years; mean poststroke duration, 13 months). They were randomly divided into the experimental group(n=20)and control group(n=19). The participants received either motor therapy focusing on the nonparetic side along with the conventional program or conventional program alone for 8 weeks (3 session/week, 60 minutes each). The balance ability was assessed using Berg Balance Scale (BBS) and Functional Reach Test (FRT) while the functional performance was measured by Barthel Index (BI).Result. After intervention, the experimental group exhibited significant(P<0.05)change on BBS (5.65 versus 2.52) and BI (12.75 versus 2.16) scores in comparison to the control group.Conclusion. The motor therapy program incorporating the nonparetic side along with the affected side was found to be effective in enhancing balance and function in stroke.

scholarly journals Magnitude integration in the Archerfish

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tali Leibovich-Raveh ◽  
Ashael Raveh ◽  
Dana Vilker ◽  
Shai Gabay
Keyword(s):  
Animal Model ◽  
Grocery Store ◽  
The Body ◽  
Water Tank ◽  
Comparison Task ◽  
Magnitude Comparison ◽  
Mathematical Abilities ◽  
In The Wild ◽  
Numerical Magnitudes ◽  
Shortest Queue

AbstractWe make magnitude-related decisions every day, for example, to choose the shortest queue at the grocery store. When making such decisions, which magnitudes do we consider? The dominant theory suggests that our focus is on numerical quantity, i.e., the number of items in a set. This theory leads to quantity-focused research suggesting that discriminating quantities is automatic, innate, and is the basis for mathematical abilities in humans. Another theory suggests, instead, that non-numerical magnitudes, such as the total area of the compared items, are usually what humans rely on, and numerical quantity is used only when required. Since wild animals must make quick magnitude-related decisions to eat, seek shelter, survive, and procreate, studying which magnitudes animals spontaneously use in magnitude-related decisions is a good way to study the relative primacy of numerical quantity versus non-numerical magnitudes. We asked whether, in an animal model, the influence of non-numerical magnitudes on performance in a spontaneous magnitude comparison task is modulated by the number of non-numerical magnitudes that positively correlate with numerical quantity. Our animal model was the Archerfish, a fish that, in the wild, hunts insects by shooting a jet of water at them. These fish were trained to shoot water at artificial targets presented on a computer screen above the water tank. We tested the Archerfish's performance in spontaneous, untrained two-choice magnitude decisions. We found that the fish tended to select the group containing larger non-numerical magnitudes and smaller quantities of dots. The fish selected the group containing more dots mostly when the quantity of the dots was positively correlated with all five different non-numerical magnitudes. The current study adds to the body of studies providing direct evidence that in some cases animals’ magnitude-related decisions are more affected by non-numerical magnitudes than by numerical quantity, putting doubt on the claims that numerical quantity perception is the most basic building block of mathematical abilities.

Mechanobiology and Adaptive Plasticity (MAP) Theory as a Potential Confounding Factor in Predicting Musculoskeletal Foot Function

2021 ◽  
Author(s):  
Greg Quinn
Keyword(s):  
Physical Nature ◽  
Theoretical Models ◽  
The Body ◽  
Adaptive Plasticity ◽  
Form And Function ◽  
Complex Processes ◽  
Kinetic Information ◽  
Foot Function ◽  
Clinical Variation ◽  
And Function

There are many theoretical models that attempt to accurately and consistently link kinematic and kinetic information to musculoskeletal pain and deformity of the foot. Biomechanical theory of the foot lacks a consensual model: clinicians are enticed to draw from numerous paradigms, each having different levels of supportive evidence and contrasting methods of evaluation, in order to engage in clinical deduction and treatment planning. Contriving to find a link between form and function lies at the heart of most of these competing theories and the physical nature of the discipline has prompted an engineering approach. Physics is of great importance in biology and helps us to model the forces that the foot has to deal with in order for it to work effectively. However, the tissues of the body have complex processes that are in place to protect them and they are variable between individuals. Research is uncovering why these differences exist and how these processes are governed. The emerging explanations for adaptability of foot structure and musculoskeletal homeostasis offer new insights on how clinical variation in outcomes and treatment effects might arise. These biological processes underlie how variation in the performance and utilisation of common traits, even within apparently similar sub-groups, make anatomical distinction less meaningful and are likely to undermine the justification of a 'foot type'. Furthermore, mechanobiology introduces a probabilistic element to morphology based on genetic and epigenetic factors.

Development of surface pattern during division in Paramecium. II. Defective spatial control in the mutant kin241

Development ◽  
1992 ◽  
Vol 115 (1) ◽  
pp. 319-335 ◽  
Author(s):  
M. Jerka-Dziadosz ◽  
N. Garreau de Loubresse ◽  
J. Beisson
Keyword(s):  
Basal Body ◽  
Major Effect ◽  
The Body ◽  
Cortical Reorganization ◽  
Surface Pattern ◽  
Recessive Mutation ◽  
Wild Type ◽  
Cortical Organization ◽  
Nuclear Reorganization ◽  
In The Wild

kin241 is a monogenic nuclear recessive mutation producing highly pleiotropic effects on cell size and shape, generation time, thermosensitivity, nuclear reorganization and cortical organization. We have analyzed the nature of the cortical disorders and their development during division, using various specific antibodies labelling either one of the cortical cytoskeleton components, as was previously done for analysis of cortical pattern formation in the wild type. Several abnormalities in basal body properties were consistently observed, although with a variable frequency: extra microtubules in either the triplets or in the lumen; nucleation of a second kinetodesmal fiber; abnormal orientation of the newly formed basal body with respect to the mother one. The latter effect seems to account for the major observed cortical disorders (reversal, intercalation of supplementary ciliary rows). The second major effect of the mutation concerns the spatiotemporal map of cortical reorganization during division. Excess basal body proliferation occurs and is correlated with modified boundaries of some of the cortical domains identified in the wild type on the basis of their basal body duplication pattern. This is the first mutant described in a ciliate in which both the structure and duplication of basal bodies and the body plan are affected. The data support the conclusion that the mutation does not alter the nature of the morphogenetic signal(s) which pervade the dividing cell, nor the competence of cytoskeletal structures to respond to signalling, but affects the local interpretation of the signals.

Morphometry in schizophrenia revisited: height and its relationship to pre-morbid function

1998 ◽  
Vol 28 (3) ◽  
pp. 655-663 ◽  
Author(s):  
P. NOPOULOS ◽  
M. FLAUM ◽  
S. ARNDT ◽  
N. ANDREASEN
Keyword(s):  
Psychosocial Adjustment ◽  
Cognitive Abilities ◽  
Economic Status ◽  
The Body ◽  
Abnormal Development ◽  
Control Group ◽  
Childhood And Adolescence ◽  
Lower Quartile ◽  
And Function ◽  
The Brain

Background. Morphometry, the measurement of forms, is an ancient practice. In particular, schizophrenic somatology was popular early in this century, but has been essentially absent from the literature for over 30 years. More recently, evidence has grown to support the notion that aberrant neurodevelopment may play a role in the pathophysiology of schizophrenia. Is the body, like the brain, affected by abnormal development in these patients?Methods. To evaluate global deficit in development and its relationship to pre-morbid function, height was compared in a large group (N=226) of male schizophrenics and a group of healthy male controls (N=142) equivalent in parental socio-economic status. Patients in the lower quartile of height were compared to those in the upper quartile of height.Results. The patient group had a mean height of 177·1 cm, which was significantly shorter than the mean height of the control group of 179·4 (P<0·003). Those in the lower quartile had significantly poorer pre-morbid function as measured by: (1) psychosocial adjustment using the pre-morbid adjustment scales for childhood and adolescence/young adulthood, and (2) cognitive function using measures of school performance such as grades and need for special education. In addition, these measures of pre-morbid function correlated significantly with height when analysed using the entire sample.Conclusions. These findings provide further support to the idea that abnormal development may play a key role in the pathophysiology of schizophrenia. Furthermore, this is manifested as a global deficit in growth and function resulting in smaller stature, poorer social skills, and deficits in cognitive abilities.

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