scholarly journals Does the kinorhynch have a hydrophobic body surface? Measurement of the wettability of a meiobenthic metazoan

2016 ◽  
Vol 3 (10) ◽  
pp. 160512 ◽  
Author(s):  
Daisuke Ishii ◽  
Hiroshi Yamasaki ◽  
Ryosuke Uozumi ◽  
Euichi Hirose
Keyword(s):  
Contact Angle ◽  
Body Surface ◽  
Water Surface ◽  
Aquatic Invertebrates ◽  
Anterior Part ◽  
The Body ◽  
Surface Measurement ◽  
Air Bubbles ◽  
Hydrophilic Surface

The body surface of aquatic invertebrates is generally thought to be hydrophilic to prevent the attachment of air bubbles. In contrast, some interstitial invertebrates, such as kinorhynchs and some crustaceans, have a hydrophobic body surface: they are often trapped at the water surface when the sediment in which they reside is mixed with air and water. Here, we directly measured the wettability of the body surface of the kinorhynch Echinoderes komatsui , using a microscopic contact angle meter. The intact body surface of live specimens was not hydrophobic, but the anterior part was less hydrophilic. Furthermore, washing with seawater significantly decreased the wettability of the body surface, but a hydrophilic surface was recovered after a 1 h incubation in seawater. We believe that the hydrophobic cuticle of the kinorhynch has a hydrophilic coat that is readily exfoliated by disturbance. Ultrastructural observations supported the presence of a mucus-like coating on the cuticle. Regulation of wettability is crucial to survival in shallow, fluctuating habitats for microscopic organisms and may also contribute to expansion of the dispersal range of these animals.

Correlation between the Minimal Cross-Sectional Area of the Nasal Cavity and Body Surface Area: Preliminary Results in Normal Patients

2002 ◽  
Vol 16 (4) ◽  
pp. 209-213 ◽  
Author(s):  
Martin Jurlina ◽  
Ranko Mladina ◽  
Krsto Dawidowsky ◽  
Davor Ivanković ◽  
Zeljko Bumber ◽  
...  
Keyword(s):  
Surface Area ◽  
Body Surface Area ◽  
Body Surface ◽  
Anterior Part ◽  
Inferior Turbinate ◽  
Objective Evaluation ◽  
Cross Sectional Area ◽  
The Body ◽  
Sectional Area ◽  
Cross Sectional

Nasal symptoms often are inconsistent with rhinoscopic findings. However, the proper diagnosis and treatment of nasal pathology requires an objective evaluation of the narrow segments of the anterior part of the nasal cavities (minimal cross-sectional area [MCSA]). The problem is that the value of MCSA is not a unique parameter for the entire population, but rather it is a distinctive value for particular subject (or smaller groups of subjects). Consequently, there is a need for MCSA values to be standardized in a simple way that facilitates the comparison of results and the selection of our treatment regimens. We examined a group of 157 healthy subjects with normal nasal function. A statistically significant correlation was found between the body surface area and MCSA at the level of the nasal isthmus and the head of the inferior turbinate. The age of subjects was not found a statistically significant predictor for the value of MCSA. The results show that the expected value of MCSA can be calculated for every subject based on anthropometric data of height and weight.

scholarly journals Does the aquatic invertebrate nipple array prevent bubble adhesion? An experiment using nanopillar sheets

2013 ◽  
Vol 9 (5) ◽  
pp. 20130552 ◽  
Author(s):  
Euichi Hirose ◽  
Hiroyuki Mayama ◽  
Akihiro Miyauchi
Keyword(s):  
Body Surface ◽  
Aquatic Invertebrates ◽  
Flat Surface ◽  
Aquatic Organisms ◽  
Hydrophobic Surface ◽  
Adhesion Energy ◽  
The Body ◽  
Surface Versus ◽  
Hydrophilic Surfaces ◽  
Flow Occlusion

The nipple array is a submicrometre-scale structure found on the cuticle surfaces of various invertebrate taxa. Corneal nipples are an antiglare surface in nocturnal insects, but the functional significance of the nipple array has not been experimentally investigated for aquatic organisms. Using nanopillar sheets as a mimetic model of the nipple array, we demonstrated that significantly fewer bubbles adhered to the nanopillar surface versus a flat surface when the sheets were hydrophilic. Many more bubbles adhered to the hydrophobic surface than the hydrophilic surfaces. Bubbles on the body surface may cause buoyancy problems, movement interference and water flow occlusion. Here, bubble repellence is proposed as a function of the hydrophilic nipple array in aquatic invertebrates and its properties are considered based on bubble adhesion energy.

scholarly journals The Function of the Anal Gills of the Mosquito Larva

1933 ◽  
Vol 10 (1) ◽  
pp. 16-26 ◽  
Author(s):  
V. B. WIGGLESWORTH
Keyword(s):  
Carbon Dioxide ◽  
Body Surface ◽  
Mosquito Larva ◽  
Anterior Part ◽  
Pure Water ◽  
Posterior Part ◽  
The Body ◽  
Glycerol Water ◽  
Hypertonic Solutions ◽  
Spontaneous Aggregation

The anal gills of the mosquito larva (Aedes argenteus) are the only region of the body that is freely permeable to water. In hypertonic solutions of sugar or glycerol, water is extracted from the gills and the larva shrinks. In pure water this is absorbed by the gills and later excreted by the Malpighian tubes. The absorption of water appears to be effected mainly by osmosis. Larvae can mature without the gills, but they seem to grow more slowly, and show almost no parenteral absorption of water. Normally the larva swallows very little fluid. The fluid in the gut is probably secreted in the posterior part of the mid-gut and reabsorbed in the anterior part and in the caeca. Some of the water excreted by the Malpighian tubes is reabsorbed in the rectum. As judged by the spontaneous aggregation of the flagellate Polytoma, oxygen is absorbed by submerged larvae all over the body surface, but most actively at the base of the gills. Carbon dioxide is given off equally all over the body surface. It is concluded that the anal gills are primarily water-absorbing organs, and are only incidentally concerned in respiration.

Contact angle of air bubbles attached to an air-water surface in foam applications

Langmuir ◽  
1990 ◽  
Vol 6 (5) ◽  
pp. 995-1001 ◽  
Author(s):  
L. A. Lobo ◽  
A. Nikolov ◽  
A. Dimitrov ◽  
P. Kralchevski ◽  
D. T. Wasan
Keyword(s):  
Contact Angle ◽  
Water Surface ◽  
Air Bubbles

scholarly journals Walking on water

2010 ◽  
Vol 644 ◽  
pp. 1-4 ◽  
Author(s):  
STEPHEN CHILDRESS
Keyword(s):  
Body Surface ◽  
Water Surface ◽  
Capillary Waves ◽  
The Body ◽  
Theoretical Modelling ◽  
Body Structure ◽  
Differential Adhesion ◽  
Water Jets ◽  
Water Striders ◽  
Frictional Forces

Many insects and spiders can travel on the water surface by rapid synchronized movements of the legs. It has been found that frictional forces, capillary waves and the creation of water jets and eddies beneath the fluid surface are all involved in the mechanisms of propulsion used by these creatures. Elaborate adaptations of the body structure mediate the wetting and de-wetting of the body surface to provide support and differential adhesion. Flow visualization as well as theoretical modelling have led to an understanding of the mechanisms invoked by water striders and spiders for water walking with a variety of gaits and speeds.

Approximate Solution of the Varying Speed Impact of 3D Bodies on the Water Surface

2021 ◽  
Author(s):  
Xueliang Wen ◽  
Peiqing Liu ◽  
Qiulin Qu ◽  
Tianxiang Hu
Keyword(s):  
Surface Tension ◽  
Approximate Solution ◽  
Pressure Distribution ◽  
Linear Relationship ◽  
Body Surface ◽  
Water Surface ◽  
The Body ◽  
Normal Impact ◽  
Dimensionless Variable ◽  
Oblique Impacts

Abstract The present paper proposes an approximate solution for the varying speed impact of 3D bodies on the water surface, with the assumptions that the fluid is considered to be incompressible, inviscid, weightless and with negligible surface tension effects and the flow ro be irrotational. The approximate solution provides a linear relationship between Cp and a dimensionless variable K, and the equation of body acceleration. These equations can be used to rapidly predict the pressure distribution on the body surface and the motions of the body. The predictions of the approximate solution match the CFD results very well for the varying speed impacts, including the normal and oblique impacts of a cone on the water surface and the normal impact of a pyramid on the water surface. The present approximate solution can be suitable for the 2D, axisymmetric and fully 3D impacts of bodies on the water surface with varying speed.

The Role of Computer Modeling in Electrocardiography

1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom
Keyword(s):  
Electrical Activity ◽  
Computer Modeling ◽  
Body Surface ◽  
Electrical Current ◽  
The Body ◽  
Volume Conductor ◽  
Current Generator ◽  
Cardiac Electrical Activity ◽  
Source Models

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.

The use of Body Surface Index as a Better Clinical Health indicators Compare to Body Mass Index and Body Surface Area for Clinical Application

2018 ◽  
pp. 131-136
Author(s):  
Shirazu I. ◽  
Theophilus. A. Sackey ◽  
Elvis K. Tiburu ◽  
Mensah Y. B. ◽  
Forson A.
Keyword(s):  
Surface Area ◽  
Body Surface Area ◽  
Clinical Application ◽  
Body Surface ◽  
Body Height ◽  
Health Indicators ◽  
The Body ◽  
Body Parameters ◽  
The Relationship ◽  
Individual Body

The relationship between body height and body weight has been described by using various terms. Notable among them is the body mass index, body surface area, body shape index and body surface index. In clinical setting the first descriptive parameter is the BMI scale, which provides information about whether an individual body weight is proportionate to the body height. Since the development of BMI, two other body parameters have been developed in an attempt to determine the relationship between body height and weight. These are the body surface area (BSA) and body surface index (BSI). Generally, these body parameters are described as clinical health indicators that described how healthy an individual body response to the other internal organs. The aim of the study is to discuss the use of BSI as a better clinical health indicator for preclinical assessment of body-organ/tissue relationship. Hence organ health condition as against other body composition. In addition the study is `also to determine the best body parameter the best predict other parameters for clinical application. The model parameters are presented as; modeled height and weight; modelled BSI and BSA, BSI and BMI and modeled BSA and BMI. The models are presented as clinical application software for comfortable working process and designed as GUI and CAD for use in clinical application.

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