The responses of miracidia and cercariae of Bunodera mediovitellata (Trematoda: Allocreadiidae) to light and to gravity

1979 ◽  
Vol 57 (3) ◽  
pp. 603-609 ◽  
Author(s):  
Murray James Kennedy
Keyword(s):  
Monochromatic Light ◽  
Larval Stages ◽  
Horizontal Beam ◽  
Phototactic Response ◽  
Glass Tubes ◽  
Vertical Glass ◽  
Response Peak ◽  
Single Response ◽  
Two Peaks ◽  
Vertical Test

Vertical glass tubes, with various portions blackened, were illuminated by a horizontal beam of white light to determine the photoresponse and georesponse of miracidia and cercariae.Four-arm test chambers were used to determine the lowest light intensity at which miracidia and cercariae showed a phototactic response. This intensity (.0.35 lx) was the same for miracidia and cercariae even though miracidia, whose next host is a bottom-dwelling clam (Pisidium casertanum), are photonegative, and cercariae, with a bottom-dwelling caddisfly larva (Limnephilus sp.) as next host, are photopositive.Two-arm test chambers, illuminated with monochromatic light, were used to determine the wavelengths to which the larval stages were responding. Cercariae showed a single response peak at 550 nm while miracidia showed two peaks, one at 550 nm and the other at 650 nm. The second peak may be a result of a screening effect by the pigment which surrounds the photoreceptor.Miracidia showed a positive georesponse when tested in vertical test tubes. However, the negative photoresponse determined their distribution in a conflicting situation. No conclusive results were obtained when the georesponse of cercariae was tested. These larvae remained on the bottom of test chambers under all conditions.

Questing height of nymphs of the bush tick, Haemaphysalis longicornis, and its closely related species, H. mageshimaensis: correlation with body size of the host

Parasitology ◽  
2004 ◽  
Vol 128 (5) ◽  
pp. 503-509 ◽  
Author(s):  
T. TSUNODA ◽  
S. TATSUZAWA
Keyword(s):  
Body Size ◽  
Sika Deer ◽  
Cervus Nippon ◽  
The Body ◽  
Haemaphysalis Longicornis ◽  
Primary Host ◽  
Closely Related Species ◽  
Glass Tubes ◽  
Vertical Glass ◽  
The Mean

The questing height (i.e. ambush height) of ticks on a plant plays an important role in host selection. To test the hypothesis that the questing height of ticks in a locality had adapted to the body size of the host in that locality, we examined the questing height of nymphs of the ticks, Haemaphysalis longicornis and H. mageshimaensis, at 7 locations in Japan. Sika deer, Cervus nippon, is the primary host of these ticks and there is considerable geographical variation in the body size of sika deer. Multiple regression analysis revealed that the questing height in the field was influenced by the height of the plants and by the body size of deer at a location. However, the questing height of ticks at some locations may have been constrained by the height of the plants and might not be the same as their intrinsic questing height. When ticks were placed in vertical glass tubes in the laboratory, the questing height of ticks from a locality was correlated with the mean body size of deer at that locality. Therefore, the prominent cue determining the questing height of H. longicornis and H. mageshimaensis seems to be the body size of the host deer.

Blood viscosity in small tubes: effect of shear rate, aggregation, and sedimentation

1987 ◽  
Vol 253 (3) ◽  
pp. H540-H547 ◽  
Author(s):  
W. Reinke ◽  
P. Gaehtgens ◽  
P. C. Johnson
Keyword(s):  
Shear Rate ◽  
Marginal Zone ◽  
Viscosity Reduction ◽  
Shear Rates ◽  
Glass Tubes ◽  
A Cell ◽  
Vertical Glass ◽  
Vertical Tubes ◽  
Aggregation Tendency ◽  
Cell Free Layer

Apparent viscosity was determined in vertical glass tubes (ID 30.2-132.3 microns) with suspensions of human red cells in A) serum, B) saline containing 0.5 g/100 ml albumin, C) plasma, and D) plasma containing Dextran 250 at a feed hematocrit of 0.45. Pressure-flow relationships were obtained in a range of pseudo-shear rates (mu) between 0.15 and 250 s-1. Relative viscosities in the nonaggregating suspensions (A and B) were found to increase monotonically with decreasing mu. The Fahraeus-Lindqvist effect was present in the entire range of mu. In the two aggregating suspensions (C and D), viscosities increased initially in larger but not small tubes with declining mu and fell in all tubes at some characteristic mu (usually below 10 s-1). Viscosity reduction was greater in the larger tubes and in suspensions with greater aggregation tendency. With suspension D, the Fahraeus-Lindqvist effect was eliminated in the lowermost shear-rate range. The cell-free marginal zone increased in width (to a maximum of approximately 40% of tube radius) as viscosity declined. Measurements of viscosity and cell-free marginal zone were also performed with suspension C in tubes mounted in horizontal position. In contrast to vertical tubes, a monotonic increase in viscosity was found with decreasing mu, associated with cell sedimentation and development of a cell-free layer only in the upper portion of the tubes.

The serum immune response of young lambs to a primary infection with Nematodirus battus

Parasitology ◽  
1996 ◽  
Vol 113 (5) ◽  
pp. 491-496 ◽  
Author(s):  
M. D. Winter ◽  
C. Wright ◽  
D. Wakelin ◽  
D. L. Lee
Keyword(s):  
Immune Response ◽  
Post Infection ◽  
Primary Infection ◽  
Infective Stage ◽  
Igg Antibodies ◽  
Subsequent Increase ◽  
Blood Samples ◽  
Response Peak ◽  
Single Response ◽  
Serum Response

SUMMARYYoung lambs (6–8 weeks of age) were infected with 50000 infective stage larvae of the trichostrongyle nematode Nematodirus battus. Initial mean adult worm burdens of 23884±1678 (S.E.M.) at day 14 post-infection (p.i.) were reduced significantly (P < 0·01) to a mean burden of 5383±1397 by day 21 p.i. Blood samples were taken and serum analysed using ELISA and Western blotting techniques for IgG antibodies specific for N. battus. Pre-infection serum from young naive animals showed IgG recognition of adult and larval N. battus whole worm homogenate. Recognition of adult antigens became reduced during the first 14 days after infection, followed by a subsequent increase beginning between days 14 and 18 p.i. and peaking at day 28 p.i. IgM recognition of N. battus antigens showed a single response peak, starting between days 14 and 18 p.i., without the pre-infection elevated titre as observed with IgG. These results show that young lambs can mount a significant serum response to a primary infection with N. battus during rejection of adult worms and that lambs receive from their dams IgG antibodies that are capable of recognizing adult and larval N. battus during the first few weeks of life.

scholarly journals An Experimental Study of Constant-Pressure Steam Injection and Transient Condensing Flow in an Air-Saturated Porous Medium

1996 ◽  
Vol 118 (2) ◽  
pp. 449-454 ◽  
Author(s):  
H. J. H. Brouwers
Keyword(s):  
Porous Medium ◽  
Constant Pressure ◽  
Water Saturation ◽  
Saturated Porous Medium ◽  
Steam Injection ◽  
Irreducible Water Saturation ◽  
Pressure Steam ◽  
Glass Tubes ◽  
Vertical Glass ◽  
Condensed Water

In this paper the unsteady process of constant pressure steam injection into an air–saturated porous medium is studied experimentally. To this end, vertical glass tubes are packed with dry quartz sand and injected with dry steam. The propagation of the steam front appears to be proportional to t. It is observed that the water saturation is homogeneously distributed and remains below the irreducible water saturation. Furthermore, the theoretical model of Brouwers and Li (1994) of the process is applied to the experiments and extended to take wall effects into account. A comparison of the predicted front penetration and amount of condensed water with the experimental results yields fairly good agreement.

Microphotometric determination of hematocrit in small vessels

1983 ◽  
Vol 245 (1) ◽  
pp. H167-H177 ◽  
Author(s):  
A. R. Pries ◽  
G. Kanzow ◽  
P. Gaehtgens
Keyword(s):  
Narrow Band ◽  
Monochromatic Light ◽  
Numerical Aperture ◽  
Original Data ◽  
Calibration Procedure ◽  
Small Vessels ◽  
Glass Tubes ◽  
Inner Diameter ◽  
Continuous Determination

Evaluation and calibration of a microphotometric method for hematocrit determination in microvessels of transilluminated tissues is described. This method is based on the relation of the optical density (OD) of a microvessel to its hematocrit (Hct). The following requirements of the microphotometric system appear essential: narrow-band monochromatic light source with efficient false light suppression, high numerical aperture of the objective and low numerical aperture of the condensor. We used a video system to measure the intensities of incident (Io) and transmitted (I) light. For converting of Io and I into OD values, correcting procedures were evaluated to eliminate the influence of glare, shading, and fading. The calibration procedure was performed with glass tubes of inner diameter (ID) between 13 and 68 microns perfused with red cell suspensions. A function was fitted to the data, correlating OD to ID and Hct. The standard deviation of the original data from this function is +/- 0.02 units of fractional hematocrit. The presented method allows the continuous determination of the hematocrit in a microvessel as well as the off-line evaluation of the hematocrit distribution within a microvessel network.

On a Differential Method for Measuring Differences of Vapour Pressures of Liquids at one Temperature and at Different Temperatures

1897 ◽  
Vol 21 ◽  
pp. 429-432
Author(s):  
Lord Kelvin
Keyword(s):  
Glass Tube ◽  
Differential Method ◽  
The Other ◽  
Glass Pipe ◽  
Metal Pipe ◽  
Different Temperatures ◽  
Glass Tubes ◽  
Vertical Glass ◽  
The Difference

§ 1. Apparatus for realising the proposed method is represented in the accompanying diagram. Two Woulffe's bottles, each having a vertical glass tube fitted air-tight into one of its necks, contain the liquids the difference of whose vapour pressures is to be measured. Second necks of the two bottles are connected by a bent metal (or glass) pipe, with a vertical branch provided with three (metal or glass) stopcocks, as indicated in the diagram. Each bottle has a third neck, projecting downwards through its bottom, stopped by a glass stopcock which can be opened for the purpose of introducing or withdrawing liquid. The upper ends of the glass tubes are also connected (by short india-rubber junctions or otherwise) with a bent metal pipe carrying a vertical branch for connection with a Toepler mercury air-pump. This vertical branch is provided with a metal stopcock. The vertical branch of the pipe fitted into necks of the two bottles is also connected to the air-pump as indicated in the drawings.§ 2. To introduce the liquids, bring open vessels containing them into such positions below the bottles that the necks project downwards into them. Close the glass stopcocks of these lower necks, open all the other six stopcocks, and produce a slight exhaustion by a few strokes of the air-pump. Then, opening the glass stopcocks very slightly, allow the desired quantities of the liquids to enter, and close them again.

PHOTOTACTIC ACTION SPECTRUM FOR WHITEFLY AND THE QUESTION OF COLOUR VISION

1972 ◽  
Vol 104 (3) ◽  
pp. 299-307 ◽  
Author(s):  
Fergus D. H. Macdowall
Keyword(s):  
Absorption Spectrum ◽  
Light Intensity ◽  
Transmission Spectrum ◽  
Colour Vision ◽  
Monochromatic Light ◽  
Action Spectrum ◽  
Light Traps ◽  
Phototactic Response ◽  
Colorimetric Data

AbstractThe peak of phototactic response of Trialeurodes (Asterochitori) vaporariorum (Westw.) to equal numbers of quanta of monochromatic light in the range 475–625 mμ occurred at 540–550 mμ. and a hump of "red" sensitivity occurred near 600 mμ. This coincided with the transmission spectrum of host leaves. The response to light intensity was hyperbolic but it was linear within the variance in the range used for the action spectrum. Corrections were made for decreasing sensitivity during experiments. The absorption spectrum of a pigmented eye-preparation included a shoulder at the wavelength that caused maximal phototaxy. Work on greenhouse light traps is recommended. Preliminary colorimetric data did not support a capacity for colour vision.

Settlement and recruitment of the crab Halicarcinus planatus (Crustacea: Decapoda: Hymenosomatidae) in Golfo San Jorge, Argentina

2010 ◽  
Vol 91 (3) ◽  
pp. 685-690 ◽  
Author(s):  
Julio H. Vinuesa ◽  
Martín Varisco ◽  
Florencia Escriche
Keyword(s):  
Smooth Surface ◽  
Central Area ◽  
The Other ◽  
Subtidal Zone ◽  
Microhabitat Use ◽  
Western Atlantic ◽  
Brachyuran Crab ◽  
Larval Stages ◽  
Cryptic Habitats ◽  
Two Peaks

The settlement and recruitment of the small brachyuran crab Halicarcinus planatus from the central area of Golfo San Jorge, south-western Atlantic Ocean, was studied. Three different artificial collectors were evaluated: smooth-surface panels, panels covered with synthetic lawn and ballasted plastic boxes filled with remains of fishing nets. In addition, plankton samples were taken monthly and water salinity and temperature were recorded. Between July 2006 and June 2007, the collectors were deployed monthly in the subtidal zone of two nearby localities and collected two months later. The recovered crabs were classified into four stages: settlers, recruits, advanced juveniles and mature crabs. There were differences in the presence of stages among collector types and seasons but not between localities. Settlers and recruits were abundant on the panels with synthetic lawn, while late juvenile and mature females were more frequent in the boxes. Larval stages occur between July and February, and only zoeas I and II were found. The males, which were only represented by early juveniles, were exclusively found on the panels with synthetic lawn, from where they would subsequently migrate to cryptic habitats such as the holdfast of Macrocystis pyrifera. Settlement occurs between September and April. Settlers showed a peak in abundance during November–December, while the recruits showed two peaks, one in December and the other in February–March. For late juveniles, the maximum abundance was recorded in April–May. Ovigerous females were found between May and September, when the experiment ended. Settlement and recruitment of H. planatus in Golfo San Jorge occur over a prolonged period. Individuals may undergo shifts in microhabitat use during this period, probably related to the search for food and shelter, and avoidance of predation and cannibalism.

Behavioral response of Dendroctonus pseudotsugae and Trypodendron lineatum (Coleoptera: Scolytidae) to selected wavelength regions of the visible spectrum

1981 ◽  
Vol 59 (11) ◽  
pp. 2159-2165 ◽  
Author(s):  
L. J. Groberman ◽  
J. H. Borden
Keyword(s):  
Behavioral Response ◽  
Visible Spectrum ◽  
Secondary Response ◽  
Behavioral Experiments ◽  
Trypodendron Lineatum ◽  
Dendroctonus Pseudotsugae ◽  
Phototactic Response ◽  
Band Pass ◽  
Response Peak ◽  
Walking Bioassay

Behavioral experiments using a phototactic response by adult Dendroctonus pseudotsugae Hopkins and Trypodendron lineatum Olivier were tested in a two-choice, walking bioassay to all possible pairs of a series of wavelengths within the visible spectrum. With Corning band-pass and cut-off filters sensitivity maxima for both sexes of D. pseudotsugae were to the shortest wavelengths (425 and 476 nm), with a secondary response to the longest wavelengths (600–625 nm). With more precise Balzer band-pass filters both D. pseudotsugae and T. lineatum responded similarly, with sensitivity maxima for both sexes to wavelengths in the region of 420–480 nm and an additional response peak around 500–525 nm. These results correspond well with other behavioral and electrophysiological data from scolytid beetles.

The Double Donor Issue of the EL2 Defect in GaAs.

1989 ◽  
Vol 163 ◽  
Author(s):  
M. O. Manasreh ◽  
G. J. Brown
Keyword(s):  
Absorption Spectrum ◽  
Fourier Transform ◽  
Complex Structure ◽  
Monochromatic Light ◽  
Thermal Recovery ◽  
Light Irradiation ◽  
Ir Absorption ◽  
Czochralski Technique ◽  
Induced Changes ◽  
Two Peaks

AbstractPhoto-induced changes in the infrared (IR) absorption spectrum of the EL2 defect in undoped and lightly alloyed unannealed GaAs materials grown by the liquid-encapsulated Czochralski technique were observed under a monochromatic light irradiation. These changes were attributed to the change of the charge states of EL2. The spectrum which is believed to be due to the charged EL2 exhibits a complex structure with two peaks at 1.07 and 1.32 eV and a shoulder at 0.94 eV. The EL2+/2+ → EL20/+ and EL20/+ → EL2+/2+ transitions were obtained by illuminating the sample with 0.7 ≤ hv ≤ 0.95 eV and 1.3 ≤ hv ≤1.5 eV, respectively. The transformation EL2+/2+ ↔ EL20/+ can be achieved in less than 10 sec and can be repeatedly switched back and forth between the two states. Fourier-transform photoconductivity (FTPC) measurements were performed on a large number of samples both semi-insulating and n-type. Two broad peaks were observed in the FTPC spectra with thresholds at 0.80 and 0.95 eV. The photoquenching and thermal recovery properties of these two peaks are identical to those of EL2. Both IR and FTPC results suggest strongly that EL2 is a double donor.

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