An apparatus for artificial circulation in laboratory animals

An artificial circulation apparatus consisting of two membrane pneumatic adaptive diaphragmatic-type pumps and artificial film-type lungs and principle of its operation are described. The apparatus permits maintaining volume blood flow to 800 ml/min during organism resuscitation after endured clinical death including prolonged one as well.     

A novel method for artificial lipid-bilayer formation

Many proposals have been made regarding the development of biosensors using single-channel recording with an artificial planar bilayer. The fragile nature of bilayer membranes is the major difficulty for the application of the artificial bilayer technique to the development of biosensors. We have developed an apparatus that promptly forms artificial bilayers. This technique is more efficient than other techniques for forming artificial bilayers. Bilayer membranes could be formed within 10s requiring 1 microl of analyte solution to record single-channel currents using our apparatus. A bilayer was formed by pressing the membrane on an agarose layer with hydraulic pressure. With this novel apparatus, we have recorded single-channel currents of various types of channels such as the BK-channel, the nicotinic receptor channel and the ryanodine receptor channel. The properties of the channels determined with this novel technique agreed well with those determined with conventional techniques.     

Microcapsule artificial kidney: treatment of patients with acute drug intoxication

The microcapsule artificial kidney was used in the treatment of three patients with acute drug intoxication. The apparatus contains 300 g. of microencapsulated activated charcoal with a total membrane area available for diffusion of more than 2m.² The membrane thickness is only 500 A. These properties make possible a compact artificial kidney whose efficiency for the removal of uremic metabolites and drugs is much higher than standard hemodialysis apparatus. The microcapsules are made blood-compatible by coating with human albumin. A roller pump was used to propel the blood through the microcapsule artificial kidney at a flow rate of 300 ml./min. for two to three hours. The clearance values for glutethimide, methyprylon and methaqualone were much higher than those achieved by standard hemodialysis. Hemoperfusion quickly lowered the drug level in the blood with resulting clinical improvement.     

Separation of apolipoprotein B species by agarose-acrylamide gel electrophoresis

Human apolipoprotein (apo) B has been recognized to exist in two different forms designated apoB-100 and apoB-48. The two apoB forms are usually separated by NaDodSO4 gel electrophoresis with a low percentage polyacrylamide gel in a tube gel apparatus. However, the matrix of this low percentage gel is relatively weak, and one can separate the two forms of apoB in a slab gel apparatus only if one utilizes a gradient polyacrylamide gel or a higher percentage polyacrylamide gel which results in a poorer separation of the protein bands. We have developed an agarose-acrylamide gel electrophoretic method to separate the two major apoB forms. The gel is a mixture of 0.5% agarose and 2% acrylamide. The agarose-acrylamide method is fast, has the advantage of being able to be used on an analytical or preparative scale in a vertical slab gel apparatus, and the gel is of sufficient strength to be used in immunoblotting and/or radioautography.     

Ultrastructure of the sexual segments of the kidney in male and female lizards,Cnemidophorus l. lemniscatus (L.)

Summary Kidneys of adult male and female lizards were studied by electron microscopy, in order to understand the ultrastructure of the collecting duct and a differentiated part thereof, the sexual segment, which is an important accessory sexual organ. First portion of sexual segment in males: The cells are filled with large secretory granules of a wide range of opacities. The granular endoplasmic reticulum is abundant; basal formations of superimposed flat cisternae are frequent. Distended vesicles and microvesicles prevail in the supranuclear, well developed Golgi apparatus. Evidences indicate that secretion of these cells is holocrine. Second portion of sexual segment in males: All of the secretory granules are apical in location and relatively electron-opaque; they show a denser core. This core is formed by a substance which, after lying in contact with ribosomes, enters the secretory vesicles of the highly developed Golgi apparatus. A lighter substance is then condensed around it. The secretion of the granules is merocrine. The granular endoplasmic reticulum is very abundant in these cells, but basal ergastoplasmic formations are lacking. Sexual segment in females: The cells show features similar to those of the male first portion, but they are smaller. Undifferentiated collecting duct: Most of the cells are mucigenic. They have small ovoid, apical secretory granules. The density of the granules varies from cell to cell; when they are electron-lucent, they exhibit laminar or dotted opaque figures. Moderately developed Golgi apparatus and granular endoplasmic reticulum, as well as elongated mitochondria, occur in mucigenic cells. Intercalated among the latter are non-secretory cells. They have very abundant mitochondria, numerous microvilli, many pinocytic and smooth-membrane vesicles, whereas the organelles participating in synthetic processes are poorly developed; their function is most likely related to active solute transport.     

A low cost gas mixer

A low cost gas mixer for permanent gases and volatile agents is described. The apparatus uses the simple principle that if known volumes of gases are mixed at the same pressure and temperature, then a mixture of known composition results. The apparatus is shown to have an accuracy of better than ± 0.08% vol/vol for gases and volatile agents in two and three part mixtures. For permanent gases the mixer could be used accurately over the concentration range 1–99% vol/vol. For volatile agents the mixer was suitable for mixing concentrations in the low percentage ranges (< 5% vol/vol). Gas mixtures, including volatile agents, could be stored in the mixer for approximately 2 h without changes in concentration outside this limit of accuracy.     

光敏蛋白菌紫质固相支撑人工膜系统的界面电荷

以固相支撑的菌紫质人工膜系统,在分子电子器件研究中占有重要地位。本文对其两种类型,Ｎ固相型和Ｃ固相型的界面电荷进行了研究,并提出了相关的模型。     

HOW A HARBOR SEAL SEES THE NIGHT SKY

Astronavigation is a possible mechanism of offshore orientation in marine mammals. However, the basic prerequisite for astronavigation is to see enough stars of the night sky. This cannot be taken for granted in seals as, due to adaptations of their dioptric apparatus to the optical properties of water, seals are supposed to be myopic and astigmatic when out of the water under low light conditions. Using various real and artificial stars in a go/no-go response paradigm we therefore determined the minimum brightness at which a harbor seal ( Phoca vitulina ) can detect stars. The dark-adapted seal was trained to look through an empty tube ("seal telescope") and to retract its head only when a star appeared at the opposite aperture. The seal reliably detected Venus or Sirius becoming suddenly visible when the telescope was moved across the night sky. Detection thresholds were determined using artificial stars (parallel light identical to starlight coming from the universe) of predefined brightness generated by an optical system installed in front of the seal's telescope. The seal detected artificial stars down to 4.4 stellar magnitudes. Although these results cannot present evidence for astronavigation, they imply that seals should see enough stars to allow such orientation mechanisms.     

Separation and determination of mass and radioactivity of fermentation gases.

A procedure is described for the separation of permanent gases on a gas chromatograph, the determination of each component by means of a thermal conductivity detector and the simultaneous measurement of radioactivity in each peak by means of a proportional counter.Procedures for calibration of the apparatus and for calculation of absolute radioactivities in samples are given.The capabilities of the apparatus are illustrated by some results of experiments with an artificial rumen using ¹⁴C- and ³H-labeled compounds.     

Sun Compass Orientation of Tylos europaeus (Crustacea, Isopoda) Under Artificial Light

To provide a first assessment of the parameters used by adult individuals of the supralittoral isopod Tylos europaeus to recognize the sun as a compass orienting reference, we used the apparatus designed and tested with the amphipod T. saltator. The apparatus reproduces a scenario similar to the natural one (with a false sun and sky illuminated artificially). The scenario produced inside the apparatus is sufficient to induce the isopods to exhibit solar orientation similar to that of conspecifics tested under the natural sun and sky. Nevertheless, this ability depends on some threshold values of illumination of the artificial sun and sky: to obtain a good orientation the irradiance of the artificial sun and sky should be more than 0.4 and 1.3 μW/cm² respectively. When the artificial sky is not illuminated, the individuals show only a photopositive tendency.     

In vivo Chlorophyll Fluorescence Monitoring with Solid State Photosensors

Solid state photosensors with their many advantages have not been utilized for chlorophyll fluorescence research. One reason is their reputed low photosensitivity compared to photomultiplier tubes. A photodarlington sensor has a relatively low photosensitivity and a nonlinear current output versus light intensity. However, when incorporated into an apparatus described in this paper it can respond to fluorescence signals from leaves using light excitation as low as 500 μW/cm². The sensitivity of another solid state device (photovoltaic photodiode) was compared to five photomultipliers using a monochromator-microphotometer testing apparatus. This solid state sensor proved to have equal or greater sensitivity to chlorophyll fluorescence. An apparatus incorporating the photovoltaic photodiode is discussed.     

Seasonal changes in the flight apparatus of winged females and sexual males of the aphid <Emphasis Type="Italic">Tuberculatus quercicola</Emphasis> (Hemiptera: Aphididae)

Tuberculatus quercicola (Matsumura) feeds on Quercus dentata Thunberg, and has mutualistic interactions with ants. Tuberculatus quercicola has two winged morphs in its life cycle, winged females appear in summer and sexual males appear in autumn. Previous studies have shown that wing loading (ratio of body volume to wing area) is higher for the winged females, because of ant attendance, resulting in extremely low dispersal. It is known that the nutritional quality of host plants is high in spring and autumn, when leaves are growing or senescent, and low in summer when leaves are mature. This study examined the effects of seasonal plant deterioration on the development of flight apparatus (wing size and flight muscle) of winged females and males. Moreover, field intercept traps were used to examine the extent of dispersal of males. The results showed that seasonal plant deterioration affected development of the flight apparatus of winged females, particularly flight muscle. Flight muscle development was significantly higher in winged males in autumn than in winged females. However, winged males were not caught in any of the traps. The different resource allocation to the flight apparatus of winged females and males is discussed.     

Moon orientation in adult and young sandhoppers under artificial light

Our experiments, carried out at night and during the day on adults and laboratory-born young of the sandhopper Talitrus saltator, deal with the identification and use of the moon as an orientating factor. Sandhoppers were released in an apparatus (a Plexiglas dome) that produced a scenario similar to the natural one (with artificial sky, moon or sun illuminated at different intensities).When tested at night, the adult and young sandhoppers used the artificial moon like the natural one, independently of the intensity of illumination of the artificial sky and moon. In other words, sandhoppers tested at night always identified the artificial moon as the moon and never as the sun. In daytime releases, the seaward orientation failed at low intensities of artificial sky and sun illumination (3.07 and 1.55 microW cm2, respectively), whereas the sun compass was used effectively at higher levels of artificial sun and sky illumination. The innate ability of moon compass orientation in inexpert young sandhoppers was demonstrated even under artificial light.     

Functional morphology of the middle ear in Chlorotalpa golden moles (Mammalia, Chrysochloridae): predictions from three models

The ossicular apparatus of golden moles in the genus Chlorotalpa has received comparatively little attention in the literature, although the malleus is known to be intermediate in size between the "unmodified" malleus of Amblysomus and the hypertrophied mallei found in some other golden moles. In the present study, the middle ear structures of three Chlorotalpa species (C. duthieae, C. sclateri, and C. arendsi) are described. Measurements of middle ear structures were applied into three existing models of middle ear function. The predictions from the models suggest that the airborne hearing of Chlorotalpa species is limited to relatively low frequencies, but the impedance transformation by the middle ear apparatus is expected to be reasonably efficient. The sensitivity of the middle ear apparatus to inertial bone conduction is intermediate between that predicted for Amblysomus and that predicted for species with hypertrophied mallei. Hearing in fossorial mammals may be limited by factors other than the middle ear apparatus: the predictions for Chlorotalpa must therefore be treated with caution. However, a consideration of the "intermediate" middle ear morphology of Chlorotalpa species sheds some light on the origin of ossicular hypertrophy in golden moles. The limited enlargement of the malleus seen in Chlorotalpa is expected to have improved seismic sensitivity by bone conduction significantly at low frequencies, while airborne hearing might not have been adversely affected.     

An artificial lipid bilayer formed on an agarose-coated glass for simultaneous electrical and optical measurement of single ion channels

The purpose of this study is to develop an apparatus for simultaneous measurement of electrical and spectroscopic parameters of single ion channels. We have combined the single channel recording apparatus with an artificial lipid bilayer and a fluorescence microscope designed to detect single fluorescent molecules. The artificial membranes were formed on an agarose-coated glass and observed with an objective-type total internal reflection fluorescence microscope (TIRFM). The lateral motion of a single lipid molecule (beta-BODIPY 530/550 HPC) was recorded. The lateral diffusion constant of the lipid molecule was calculated from the trajectories of single molecules as D = 8.5 +/- 4.9 x 10(-8) cm(2)/s. Ionic channels were incorporated into the membrane and current fluctuations were recorded at the single-channel level. After incorporation of Cy3-labeled alametithin molecules into the membrane, bright spots were observed moving rather slowly (D = 4.0 +/- 1.6 x 10(-8) cm(2)/s) in the membrane, simultaneously with the alametithin-channel current. These data show the possibility of the present technique for simultaneous measurement of electrical and spectroscopic parameters of single-channel activities.     

The separation of above- and below-ground competition in plants A review and critique of methodology

The relative merits of different methods for separating root and shoot competition in plants are reviewed. The `Divided Pot' technique involves vertical partitions that divide above- and below-ground competition within pots. This design usually creates unrealistic competition for light by using artificial barriers around pot perimeters to contain above-ground growth and by using a constant orientation of incident light from directly above. The `Row' technique involves parallel rows of plants that are separated by vertical partitions above- and below-ground. Although, this design may be well suited to some agricultural applications, its value for field studies of wild plants is limited. The Divided Pot and Row techniques have been associated often with the replacement series design, which has a number of limitations. The `Target' technique has always been associated with an additive planting design as it involves surrounding a plant of interest (the `target') with other plants (the `neighbours') while including above- and below-ground partitions to prevent root and shoot competition. Most studies using this technique have not provided adequate control for apparatus effects, yet this method appears to have the most potential for application in ecological studies, especially in the field. A standard protocol for the target technique is proposed allowing greater control over potential apparatus effects than in previous studies and allowing assessment of the interaction between root competition and shoot competition.     

The electron microscopic and classic Golgi apparatus

The relationship of the membrane structure, designated in electron microscopy as the Golgi apparatus, to the classic Golgi apparatus in the light microscope were studied withFagopyrum. Comparison of these structures in plant cells with the same or similar structures in animal cells led to the following conclusions: there exist two groups of formations, impregnable with osmium or silver, considered as the classic Golgi apparatus. The first group contains the active membrane structures. These are the dictyosomes and the anastomosing form of the electron microscopic Golgi apparatus. To this group belongs also the endoplasmatic reticulum, which in plant cells forms dense vacuoles, having the appearance of the classic Golgi apparatus, and in animal cells occasionally has a similar arrangement as the anastomosing form of the Golgi apparatus. The second group comprises formation containing reserve and secretion material, i.e. predominantly products of the activity of the electron microscopic Golgi apparatus and of the endoplasmic reticulum (matter of the dense vacuoles, lipochondria, secretory granula etc.). In the plant cells, especially ofFygopyrum, the dictyosomes contained in the structures of the first group are separated from the formations of a reserve character in the second group, formed in the lumen of the endoplasmic reticulum (dense vacuoles). The identity of the dictyosomes with the osmiophilic platelets, considered by some authors in the light microscope as the classic Golgi apparatus, has not been proved up to present, because of the one-sidedness of the methods used nowadays. WithFagopyrum no foundation has been observed for the assumed formation of net-form structures by grouping of the dictyosomes. Structures similar to the net-form of the classic Golgi apparatus in the animal cell form only dense vacuoles. On the basis of the differentiation of both types of formations in the plant cell, the foundations were laid for the characterization of the classic Golgi apparatus in the animal cell. The net-form of the classic Golgi apparatus in the animal cell is obviously not artificial, but reflects the ultrastructural arrangement of the electron microscopic Golgi apparatus or of the endoplasmic reticulum. The problem of the suitability and specification of the name Golgi apparatus in the animal and plant cell was also discussed. In contrast to the opinion of some authors, it does not appear useful to remove the name golgi apparatus, designating the dictyosomes and the anastomosing forms of the smooth membranes.     

Comparative morphology of selected characters of the Pentatomidae foreleg (Hemiptera,Heteroptera)

Heteropteran legs are very diverse within and among taxa, and such variation is frequently correlated with life habits. Structural modifications are commonly present in the legs of the Pentatomoidea but are poorly studied. Using scanning electron microscopy, the tibia and pretarsal microstructure of 82 species of Pentatomidae (Heteroptera), three species of Scutelleridae, and ten species of Thyreocoridae were described, focusing on the pretarsal structure, the foretibial apparatus, and the foretibial comb. The Pentatomidae, the Scutelleridae, and the Thyreocoridae have uniform pretarsal structures. Variation can be found in the length of the parempodial setae and in the shape of the parempodial projections. The foretibial combs of the Pentatomidae, the Thyreocoridae, and the Scutelleridae are described for the first time, and we have demonstrated that there is low structural variation in the foretibial comb complex of the studied species. The setae organization and distribution on the foretibial apparatus is uniform in the families studied. However, the Asopinae (Pentatomidae) bear a foretibial apparatus that is uniquely organized. The taxonomic and phylogenetic relevance of the pretarsal traits, the foretibial apparatus, and the foretibial comb are discussed.     

Reef aerial photography from a kite

Summary The construction and operation of a mechanism for taking aerial photographs from a kite are described. The apparatus is inexpensive, light and robust and is operated by two people. This method of low level aerial photography, vertical or oblique from an altitude of 50 to 200 m, is ideal for surveys of reef flats and islands where winds of 7 to 25 knots are encountered.