The effect of stimulus features on the visual orienting behaviour of the salamander Plethodon jordani

2002 ◽  
Vol 205 (2) ◽  
pp. 241-251
Author(s):  
Niklas Schülert ◽  
Ursula Dicke
Keyword(s):  
Rank Order ◽  
Movement Pattern ◽  
The Body ◽  
Likelihood Method ◽  
Visual Features ◽  
Entire Body ◽  
Local Motion ◽  
Prey Recognition ◽  
Plethodon Jordani ◽  
Stimulus Features

SUMMARY The effects of the visual features of prey-like objects on the orienting behaviour of the salamander Plethodon jordani were studied. Two stimuli (cricket dummies, rectangles), moving in opposite directions, were presented simultaneously on a computer screen. They differed in size, contrast, velocity and movement pattern of the entire body or the body appendages. Size and velocity appeared to be the dominant features; shape was of lesser importance. Contrast and movement pattern were of intermediate importance and local motion of little importance. This rank order was the same when the probability of a response to the different stimuli was estimated by means of the maximum-likelihood method. Cluster analysis revealed that in all animals stimuli could be grouped into five clusters. Among individuals, the rank order of stimuli was similar for high- and low-ranking stimuli and varied for those of intermediate rank; stimuli could be grouped into 3–5 clusters. Our findings favour the view that, in amphibians, prey recognition is guided by a number of visual features acting either alone or in combination and depending on internal motivational or attentional states and individual experience. Movie available on-line: http://www.biologists.com/JEB/movies/jeb3864.html.

Surface ultrastructure of juvenile and adult stages of Centrocestus armatus

1998 ◽  
Vol 72 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Ho-Choon Woo ◽  
Myung-Deuk Seo ◽  
Sung-Jong Hong
Keyword(s):  
Oral Sucker ◽  
Body Surface ◽  
Dorsal Surface ◽  
High Density ◽  
The Body ◽  
Albino Rats ◽  
Entire Body ◽  
Type Ii ◽  
Posterior Half ◽  
Surface Ultrastructure

AbstractCentrocestus armatus (Trematoda: Heterophyidae) develops rapidly and produces eggs at 3 days postinfection in albino rats. Excysted metacercariae are pear-shaped and concave ventrally, with 42–44 peg-like circumoral spines. The entire body surface is densely covered with scale-like serrated spines. On juveniles, serration of the tegumental spines is greatest in the middle of the ventral and dorsal surfaces, and decreases anteriorly and posteriorly. Ciliated sensory papillae are concentrated around the oral sucker. Several nonciliated sensory papillae (type II papillae) occur equidistantly on the acetabulum and are arranged in a linear symmetry on the dorsal surface. On adults, the serration of the tegumental spines decreases to 14–17 tips on the ventrolateral surface. The high density of tegumental spines on posterior half of the body and the distribution of type II papillae on dorsal surface are considered to be characteristic of C. armatus.

A Benchmark Control Problem for Supercavitating Vehicles and an Initial Investigation of Solutions

2003 ◽  
Vol 9 (7) ◽  
pp. 791-804 ◽  
Author(s):  
John Dzielski ◽  
Andrew Kurdila
Keyword(s):  
High Speed ◽  
Linear Models ◽  
The Body ◽  
Control Surface ◽  
Force Model ◽  
Entire Body ◽  
Benchmark Problem ◽  
Supercavitating Vehicles ◽  
Forcing Function ◽  
Natural Cavitation

At very high speeds, underwater bodies develop cavitation bubbles at the trailing edges of sharp corners or from contours where adverse pressure gradients are sufficient to induce flow separation. Coupled with a properly designed cavitator at the nose of a vehicle, this natural cavitation can be augmented with gas to induce a cavity to cover nearly the entire body of the vehicle. The formation of the cavity results in a significant reduction in drag on the vehicle and these so-called high-speed supercavitating vehicles (HSSVs) naturally operate at speeds in excess of 75 m s-1. The first part of this paper presents a derivation of a benchmark problem for control of HSSVs. The benchmark problem focuses exclusively on the pitch-plane dynamics of the body which currently appear to present the most severe challenges. A vehicle model is parametrized in terms of generic parameters of body radius, body length, and body density relative to the surrounding fluid. The forebody shape is assumed to be a right cylindrical cone and the aft two-thirds is assumed to be cylindrical. This effectively parametrizes the inertia characteristics of the body. Assuming the cavitator is a flat plate, control surface lift curves are specified relative to the cavitator effectiveness. A force model for a planing afterbody is also presented. The resulting model is generally unstable whenever in contact with the cavity and stable otherwise, provided the fin effectiveness is large enough. If it is assumed that a cavity separation sensor is not available or that the entire weight of the body is not to be carried on control surfaces, limit cycle oscillations generally result. The weight of the body inevitably forces the vehicle into contact with the cavity and the unstable mode; the body effectively skips on the cavity wall. The general motion can be characterized by switching between two nominally linear models and an external constant forcing function. Because of the extremely short duration of the cavity contact, direct suppression of the oscillations and stable planing appear to present severe challenges to the actuator designer. These challenges are investigated in the second half of the paper, along with several approaches to the design of active control systems.

The philometrid nematodePhilometroides acreanensis n. sp. from the stomach wall of the catfishPimelodus blochiiin north-western Brazil

2017 ◽  
Vol 92 (1) ◽  
pp. 109-115 ◽  
Author(s):  
P.H.O. Cavalcante ◽  
F. Moravec ◽  
C.P. Santos
Keyword(s):  
Body Length ◽  
Gravid Female ◽  
Drainage System ◽  
Nematode Species ◽  
Fish Host ◽  
The Body ◽  
Stomach Wall ◽  
Amazon River ◽  
Entire Body ◽  
South American

AbstractA new nematode species,Philometroides acreanensisn. sp. (Philometridae), is described from female specimens recovered from the stomach wall of the freshwater catfishPimelodus blochiiValenciennes (Pimelodidae) collected in the Acre River (Amazon River basin), Acre State, Brazil. Based on examination by light and scanning electron microscopy, the new species differs from the two other South American congeneric species mainly in the body length of the gravid female (240–280 mm), the length of the oesophagus (1.25 mm in holotype) representing 0.5% of the entire body length, the range of cuticular embossment, as well as the location in the host (stomach), order of the fish host (Siluriformes) and the geographical distribution (Amazon River drainage system). This is the third known species ofPhilometroidesYamaguti, 1935 reported from South America. A key to species ofPhilometroidesoccurring in the fish of America is provided.

Effect of shodhana and shamana chikitsa in mandala kustha (psoriasis): A case study

2019 ◽  
Vol 7 (03) ◽  
Author(s):  
Jyoti Bala Sahu
Keyword(s):  
Body Temperature ◽  
The Body ◽  
Entire Body ◽  
Men And Women ◽  
Remarkable Improvement ◽  
Males And Females ◽  
Regulate Body Temperature ◽  
Old Men

Skin is the largest organ of the body both by surface area and weight. This covers the entire body. The thickness of skin varies considerably over all parts of the body and between young and old, men and women. It helps to regulate body temperature, stores water fat and permit sensation of touch. Psoriasis is a chronic dermatosis characterized by covered by silvery loose scales. Treatment available on contemporary system is not curative but suppressive only. The prevalence of psoriasis is 8%. Prevalence equal in males and females. A case of Mandala Kustha discussed here. Patient successfully treated with Shodhana (Virechana karma) & Shamana Chikitsa. After course of 2 months treatment provides significant relief in Sign and Symptoms. In our classics mentioned Shodhana Chikitsa for Kustha Roga. Considering the sign and symptoms of patient was treated with classical Virechana karma (therapeutic purgation) and Shamana Chikitsa according to line of treatment of Kustha (Psoriasis). Assessment was done on before treatment, after treatment and after follow up of 2 months; pictures were taken before treatment and after treatment. Remarkable improvement was noticed, induration and itching after Virechana treatment.

Active head movements facilitate compensation for effects of prism displacement on dynamic gait12

2006 ◽  
Vol 16 (1-2) ◽  
pp. 29-33
Author(s):  
Kim R. Gottshall ◽  
Michael E. Hoffer ◽  
Helen S. Cohen ◽  
Robert J. Moore
Keyword(s):  
Head Movement ◽  
Sensory Modality ◽  
Normal Subjects ◽  
The Body ◽  
Head Movements ◽  
Head Motion ◽  
Control Group ◽  
Entire Body ◽  
Group 3 ◽  
Group 2

Study design: Four groups, between-subjects study. Objectives: To investigate the effects of exercise on adaptation of normal subjects who had been artificially spatially disoriented. Background: Many patients referred for rehabilitation experience sensory changes, due to age or disease processes, and these changes affect motor skill. The best way to train patients to adapt to these changes and to improve their sensorimotor skills is unclear. Using normal subjects, we tested the hypothesis that active, planned head movement is needed to adapt to modified visual input. Methods and measures: Eighty male and female subjects who had normal balance on computerized dynamic posturography (CDP) and the dynamic gait index (DGI), were randomly assigned to four groups. All groups donned diagonally shift lenses and were again assessed with CDP and DGI. The four groups were then treated for 20 min. Group 1 (control group) viewed a video, Group 2 performed exercise that involved translating the entire body through space, but without separate, volitional head movement, Group 3 performed exercises which all incorporated volitional, planned head rotations, and Group 4 performed exercises that involved translating the body (as in Group 2) and incorporated volitional, planned head motion (as in Group 3). All subjects were post-tested with CDP and DGI, lenses were removed, and subjects were retested again with CDP and DGI. Results: The groups did not differ significantly on CDP scores but Groups 3 and 4 had significantly better DGI scores than Groups 1 and 2. Conclusions: Active head movement that is specifically planned as part of the exercise is more effective than passive attention or head movements that are not consciously planned, for adapting to sensorimotor change when it incorporates active use of the changed sensory modality, in this case head motion.

scholarly journals Morphological characteristic of black-winged myna (acridotheres melanopterus)*

2018 ◽  
Vol 197 ◽  
pp. 06006 ◽  
Author(s):  
Renaldi Ednin Vernia ◽  
Anais Tritto ◽  
Abinawanto Abinawanto ◽  
Nurul Winarni ◽  
Anita mayasari ◽  
...  
Keyword(s):  
Morphological Characteristic ◽  
Sample Selection ◽  
Digital Camera ◽  
Morphological Characteristics ◽  
The Body ◽  
Entire Body ◽  
Body Parts ◽  
Breeding Management ◽  
Black Feather ◽  
Average Body

Black-winged myna (Acridotheres melanopterus) is an endemic bird of Java and Bali, currently critically endangered based on International Union of Conservation for Nature (IUCN) since 2010. The study about black-winged myna morphological characteristic is important because it has two relatives with almost identical features of morphology. The information can be used as a basis in breeding management to avoid hybridization. The study aims to determine the morphological characteristics of black-winged myna. The sample selection was done using purposive sampling method. Data was taken from 36 black-winged mynas with >=2 years old. Data collection was done by measuring and documenting every morphological feature of the observed body parts. Documentation of the wings, back, chest, head and sides of the body are taken from each bird using a digital camera. The results showed that almost the entire body of black-winged myna covered by white feather, black feather only present on the cover of the wings and tail. Black eyes surrounded by yellow skin without feather. The beak is orange with blackish parts around the nostrils. The bird has yellow legs with three fingers at the front and one finger at the back. The average body length of this bird is 22.5 cm, weight 89.02 g, width 5.98 cm, body circumference 14.36 cm and wingspan 38.49 cm.

scholarly journals Predictive remapping of visual features beyond saccadic targets

2018 ◽  
Author(s):  
Tao He ◽  
Matthias Fritsche ◽  
Floris P. de Lange
Keyword(s):  
Visual Field ◽  
Strong Evidence ◽  
Visual Features ◽  
Visual Stability ◽  
Relevant Object ◽  
Saccade Onset ◽  
Predictive Remapping ◽  
Feature Information ◽  
Stimulus Features ◽  
Predictive Feature

AbstractVisual stability is thought to be mediated by predictive remapping of the relevant object information from its current, pre-saccadic locations to its future, post-saccadic location on the retina. However, it is heavily debated whether and what feature information is predictively remapped during the pre-saccadic interval. Using an orientation adaptation paradigm, we investigated whether predictive remapping occurs for stimulus features and whether adaptation itself is remapped. We found strong evidence for predictive remapping of a stimulus presented shortly before saccade onset, but no remapping of adaptation. Furthermore, we establish that predictive remapping also occurs for stimuli that are not saccade targets, pointing toward a ‘forward remapping’ process operating across the whole visual field. Together, our findings suggest that predictive feature remapping of object information plays an important role in mediating visual stability.

scholarly journals CRITICAL STUDY OF TVAK IN THE VIEW OF MODERN SCIENCE: A REVIEW ARTICLE

2021 ◽  
Vol 9 (8) ◽  
pp. 1795-1799
Author(s):  
Ishan Malhotra ◽  
Sakshi Sakshi ◽  
Subhash Upadhyay
Keyword(s):  
Direct Contact ◽  
External Surface ◽  
Modern Science ◽  
Review Article ◽  
The Body ◽  
Critical Study ◽  
Entire Body ◽  
Internal Structures ◽  
Normal Colour ◽  
Modern Era

In Ayurveda, the term Tvak, Twacha and Charma are frequently used to denote the skin. Tvak is described as the organ which covers the external surface of the entire body. Tvak and its related diseases have great importance because these are easily noticeable. It is the first part of the body that is in direct contact with any harmful sub- stances or infective microorganisms. It protects the internal structures of the body from injury or infections and regulates the temperature of the body. Skin is also the beauty of a human being. Therefore, it should be protected from any abnormal conditions. Ayurveda Acharyas have described Tvak many years ago. They explained each layer of Tvak in meaningful sequences, its related diseases and measurement of each layer. They also explained that it maintains the normal colour of individuals and conveys the sensation of touch. Some topics of Ayurveda are easy to understand, and some topics become easy if we study along with modern science. So, for a proper un- derstanding of the concept of Tvak, it is very essential to correlate it with modern science and elaborate according to the modern era. Keywords: Tvak, Sparshanendriya, Sharirsthan, Santanika, Vrihi, Skin, Dermis, Epidermis

scholarly journals Imagination der Bewegung durch Vibrationsreize – ein neuer Ansatz in der Frühmobilisation auf der Intensivstation?

2020 ◽  
Vol 26 (4) ◽  
pp. 214-218
Author(s):  
M. Lippert-Grüner ◽  
B. Bakaláø ◽  
R. Zajíèek ◽  
F. Duška
Keyword(s):  
Nervous System ◽  
Intensive Care ◽  
Pilot Study ◽  
Sensory Information ◽  
Early Mobilization ◽  
Motor Units ◽  
The Body ◽  
Entire Body ◽  
Vibration Effect ◽  
Illusory Movement

Zusammenfassung Die Optimierung der motorischen Leistung und die Einbindung und Vernetzung bisher nicht verwendeter motorischer Einheiten sowie die vermehrte Ausschüttung neurotropher Faktoren sind zentrale Mechanismen der Vibrationswirkung, die therapeutisch auf einzelne Körperteile oder den gesamten Körper angewendet werden können. Eine Möglichkeit, die Frühmobilisation bei kritisch kranken Patienten effektiver zu gestalten und immobilitätsbedingten Veränderungen vorzubeugen, könnte die Verwendung des Vibramoov™-Systems sein. Gezielt programmierte Vibrationssequenzen stimulieren hier das Nervensystem mit sensorischen Informationen, die die Empfindung einer Bewegung nachahmen (z. B. des Gehens) und somit Regenerations- und Reor-ganisationsprozesse im zentralen Nervensystem unterstützen können. Von Bedeutung ist dieser Therapieansatz vor allem bei Patienten, bei denen aufgrund ihres Zustandes konventionelle Maßnahmen nicht oder nur eingeschränkt durchgeführt werden können. Da bisher keine Erfah-rungen zur Anwendung bei intensivpflichtigen Patienten verfügbar sind, wurde eine Pilotstudie durchgeführt mit der Fragestellung, ob diese Therapieform sicher ist und im normalen Betrieb auf der Intensivstation verwendet werden kann. Die Ergebnisse der Pilotstudie mit fünf Patienten zei-gen, dass die Anwendung von Vibramoov™ zu keiner wesentlichen Veränderung kardiopulmo-naler Parameter im Sinne einer Non-Toleranz führte und im klinischen Setting gut umsetzbar war. Schlüsselwörter: Frührehabilitation, Imagination von Bewegung, Intensivstation, Vibramoov™ Imagination of movement through vibrational stimuli – a new approach to early mobilization in intensive care units? A pilot study Abstract The optimization of motor performance and the integration and networking of previously unused motor units, as well as the increased release of neurotrophic factors, are central mechanisms related to the vibration effect that can be applied therapeutically to individual parts of the body or to the entire body. One way to make early mobilization more effective in critically ill patients and to prevent changes due to immobility could be rehabilitation with functional proprioceptive stimulation, also known as “illusory movement”. Specifically programmed vibration sequences stimulate the nervous system with sensory information that mimics the sensation of movement (e. g., walking) and can thus support regeneration and reorganization processes in the central nervous system. This therapeutic approach is particularly important for patients who, due to their condition, cannot – or only to a limited extent – carry out conventional measures. Since no experience has so far been available for use in intensive care patients, we carried out a pilot study to answer the question of whether this form of therapy can be used safely and in normal operations in the intensive care unit. The results of the pilot study with 5 patients showed that the use of Vibramoov™ did not lead to any significant change in cardiopulmonary parameters in terms of non-tolerance and was easy to implement in a clinical setting. Keywords: early rehabilitation, illusory movements, ICU, functional proprio-ceptive stimulation

On the Amphilaphorchidinae, A New Subfamily of Proteocephalid Cestodes, and Myzophorus admonticellia, gen. et sp.n., Parasitic in Pirinampus spp. from the Amazon

Parasitology ◽  
1934 ◽  
Vol 26 (1) ◽  
pp. 141-149 ◽  
Author(s):  
W. N. F. Woodland
Keyword(s):  
British Museum ◽  
The Body ◽  
Entire Body ◽  
Adipose Fin ◽  
General Appearance

“Piranabú,” “Piranampú” or “Piranampú” (the last according to Goeldi, 1898) are local names on the Amazon applied to the siluroid fish which, so far as it is possible to determine from memory and from the rough sketches and notes which I made at the time, is the modern Pirinampus pirinampus (Spix). This fish, of which I examined eight examples, attains a length of at least 60 cm., has an elongated adipose fin more than one-third the length of the entire body, microscopic scales, possesses maxillary barbels about half the length of the body, and in general appearance closely resembles the figure (Tab. VIII, a) of “Pimelodus ctenodus” provided by Spix (1829). I am much indebted to Mr J. R. Norman, of the British Museum, for his kind assistance in identification.

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