Sperm transport in the fowl

(1) The distributions of living and dead sperm in the oviducts of hens a t various time intervals after artificial insemination were determined by using sperm labelled with 32P and assaying the radioactivity of serial sections of the oviduct. Appropriate. tests of the method showed it to be valid and reasonably accurate for short-term experiments. (2) The number of sperm reaching the site of fertilization at the upper end of the oviduct (the infundibulum) was dependent primarily on where in the lower genital tract the sperm were deposited. Following intravaginal insemination with 2 X 108 sperm, from 7 X 103 to 70 X 103 sperm were detected in the infundibula of different hens up to 1 hr after insemination. After intra-uterine insemination with a like number, from 137 X 103 to 2642 X 10103 sperm were detected. (3) The junction of the vagina and uterus (or shell gland) proved to be a barrier to sperm progress, as was shown by the greater efficiency of sperm utilization above the junction than below it. (4) Dead sperm inseminated intravaginally did not pass into the uterus but those inseminated into the uterus reached the infundibulum in as great numbers as a similar sample of living sperm. This suggested that the mechanism of sperm transport differs on either side of the uterovaginal junction. (5) From the speed of transport of sperm and the passage up the oviduct of sperm-free fluid injected into the uterus, it is suggested that the spasmodic contraction of muscle investing the wall of the upper vagina and lower uterus induced as a response to tactile stimuli is mainly responsible for sperm movement from the uterovaginal junction to the infundibulum. (6) Motility of sperm is necessary only to traverse the vagina and perhaps to penetrate the vitelline membrane of the egg during the process of fertilization. At other stages of movement between the vagina and the egg, sperm play a passive role in their own transport.

Download Full-text

Rotational Characteristics of the Green Solar Corona: 1947-1991

International Astronomical Union Colloquium ◽

10.1017/s0252921100025197 ◽

1994 ◽

Vol 144 ◽

pp. 139-141 ◽

Cited By ~ 2

Author(s):

J. Rybák ◽

V. Rušin ◽

M. Rybanský

Keyword(s):

Solar Corona ◽

World Wide ◽

Rotation Period ◽

Original Data ◽

Coronal Emission ◽

Time Intervals ◽

Data Set ◽

The World ◽

Coronal Emission Line ◽

Homogeneous Data

AbstractFe XIV 530.3 nm coronal emission line observations have been used for the estimation of the green solar corona rotation. A homogeneous data set, created from measurements of the world-wide coronagraphic network, has been examined with a help of correlation analysis to reveal the averaged synodic rotation period as a function of latitude and time over the epoch from 1947 to 1991.The values of the synodic rotation period obtained for this epoch for the whole range of latitudes and a latitude band ±30° are 27.52±0.12 days and 26.95±0.21 days, resp. A differential rotation of green solar corona, with local period maxima around ±60° and minimum of the rotation period at the equator, was confirmed. No clear cyclic variation of the rotation has been found for examinated epoch but some monotonic trends for some time intervals are presented.A detailed investigation of the original data and their correlation functions has shown that an existence of sufficiently reliable tracers is not evident for the whole set of examinated data. This should be taken into account in future more precise estimations of the green corona rotation period.

Download Full-text

Prolonged Fixation Studies For Spaceflight

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072101 ◽

1973 ◽

Vol 31 ◽

pp. 332-333

Author(s):

Robert Corbett ◽

Delbert E. Philpott ◽

Sam Black

Keyword(s):

High Pressure ◽

Living Systems ◽

Prolonged Storage ◽

Time Intervals ◽

Early Signs ◽

Large Numbers

Observation of subtle or early signs of change in spaceflight induced alterations on living systems require precise methods of sampling. In-flight analysis would be preferable but constraints of time, equipment, personnel and cost dictate the necessity for prolonged storage before retrieval. Because of this, various tissues have been stored in fixatives and combinations of fixatives and observed at various time intervals. High pressure and the effect of buffer alone have also been tried.Of the various tissues embedded, muscle, cartilage and liver, liver has been the most extensively studied because it contains large numbers of organelles common to all tissues (Fig. 1).

Download Full-text

Ultrastructure of Lymphatic Capillaries in the Transport of Colloidal Particles

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060945 ◽

1967 ◽

Vol 25 ◽

pp. 186-187

Author(s):

L. V. Leak ◽

J. F. Burke

Keyword(s):

Connective Tissue ◽

Colloidal Particles ◽

Ultrastructural Level ◽

Vital Role ◽

Time Intervals ◽

Thorium Dioxide ◽

Lymphatic Capillary ◽

Tissue Area ◽

Rapid Removal ◽

Tissue Fluids

The vital role played by the lymphatic capillaries in the transfer of tissue fluids and particulate materials from the connective tissue area can be demonstrated by the rapid removal of injected vital dyes into the tissue areas. In order to ascertain the mechanisms involved in the transfer of substances from the connective tissue area at the ultrastructural level, we have injected colloidal particles of varying sizes which range from 80 A up to 900-mμ. These colloidal particles (colloidal ferritin 80-100A, thorium dioxide 100-200 A, biological carbon 200-300 and latex spheres 900-mμ) are injected directly into the interstitial spaces of the connective tissue with glass micro-needles mounted in a modified Chambers micromanipulator. The progress of the particles from the interstitial space into the lymphatic capillary lumen is followed by observing tissues from animals (skin of the guinea pig ear) that were injected at various time intervals ranging from 5 minutes up to 6 months.

Download Full-text

Priming effects between spatial meaning of verbs and numbers are modulated by time intervals: Early interference and late facilitation.

Canadian Journal of Experimental Psychology/Revue canadienne de psychologie expérimentale ◽

10.1037/cep0000085 ◽

2016 ◽

Vol 70 (4) ◽

pp. 295-300 ◽

Cited By ~ 3

Author(s):

Martin Lachmair ◽

Susana Ruiz Fernández ◽

Peter Gerjets

Keyword(s):

Time Intervals ◽

Priming Effects

Download Full-text

Differences in the Perception of Empty and Filled Time Intervals by Pigeons

PsycEXTRA Dataset ◽

10.1037/e603992013-026 ◽

2006 ◽

Author(s):

Angelo Santi ◽

Dwayne Keough ◽

Patrick Van Rooyen

Keyword(s):

Time Intervals

Download Full-text

Perceptions Of The Length Of Future Time Intervals: The Role Of Certainty

PsycEXTRA Dataset ◽

10.1037/e722852011-062 ◽

2007 ◽

Author(s):

Robyn A. LeBoeuf ◽

Joseph P. Simmons

Keyword(s):

Future Time ◽

Time Intervals

Download Full-text

In Vitro Incorporation of Sodium Acetate-l-C14 into Leukocyte Lipids of Normal and Leukaemic Subjects as a Function of Incubation Time

Nuklearmedizin ◽

10.1055/s-0037-1621180 ◽

1962 ◽

Vol 02 (02) ◽

pp. 165-172

Author(s):

C Miras ◽

G Lewis ◽

J Mantzos

Keyword(s):

Sodium Acetate ◽

Linear Part ◽

Lipid Synthesis ◽

Normal Subjects ◽

Cytostatic Agents ◽

Time Intervals ◽

Total Blood ◽

Effect Of Treatment ◽

Product Relation

Summary1. Separated leukocytes or total blood from normal subjects, untreated leukaemic patients and from leukaemic patients treated with cytostatic agents were incubated with CH3COONa-l-C14. Radioactivity of mixed lipids was measured at standard time intervals.2. The time incorporation curve observed with leukocytes from treated leukaemic patients showed after an initial linear part, a more rapid levelling off than the curves observed with leukocytes from untreated and normal subjects.3. Therefore, an indirect effect of treatment on leukocyte lipid synthesis seems to be present.4. Phospholipid and neutral lipid synthesis by leukaemic leukocytes was also studied. The results give no evidence that these fractions as a whole have any precursor-product relation.

Download Full-text

Comparative Chemical, Biological and Clinical Studies of 99mTc-Glucoheptonate and 99mTc-Dimercaptosucci- nate as Used in Renal Scintigraphy

Nuklearmedizin ◽

10.1055/s-0037-1620873 ◽

1979 ◽

Vol 18 (01) ◽

pp. 40-45 ◽

Cited By ~ 1

Author(s):

M. Malešević ◽

Lj. Stefanović ◽

N. Vanlić-Razumenić

Keyword(s):

Clinical Studies ◽

Gamma Camera ◽

Radiochemical Purity ◽

Renal Cortex ◽

Renal Scintigraphy ◽

Time Intervals ◽

Experimental Animals ◽

Dynamic Studies

The renal radiopharmaceutical preparations 99mTc-DMS and 99mTc-GH were examined chemically, biologically and clinically. Both preparations are of high radiochemical purity. The biodistribution of both preparations was examined in experimental animals at different time intervals, from 15 min to 4 hr; the percentage of incorporation of 99mTc-DMS into kidneys is much higher (29.4% to 52.0%) than that of 99mTc-GH (12.80% to 22.20%). Both preparations accumulate to a greater extent in the renal cortex than in the medulla.The most suitable time for renal scintigraphy for "mTc-DMS is 90-150 min while for 99mTc-GH it is 60-90 min. It is concluded that 99mTc-DMS is more suitable for static scintigrams on the scanner and 99mTc-GH for dynamic studies with the gamma camera.

Download Full-text

Planning the Size of Clinical Trials with Allowance for Patient Noncompliance

Methods of Information in Medicine ◽

10.1055/s-0038-1634787 ◽

1990 ◽

Vol 29 (03) ◽

pp. 243-246 ◽

Cited By ~ 2

Author(s):

M. A. A. Moussa

Keyword(s):

Clinical Trial ◽

Clinical Trials ◽

Sample Size ◽

Event Rate ◽

Survival Functions ◽

Time Intervals ◽

Patient Noncompliance ◽

Event Rates ◽

Larger Sample

AbstractVarious approaches are considered for adjustment of clinical trial size for patient noncompliance. Such approaches either model the effect of noncompliance through comparison of two survival distributions or two simple proportions. Models that allow for variation of noncompliance and event rates between time intervals are also considered. The approach that models the noncompliance adjustment on the basis of survival functions is conservative and hence requires larger sample size. The model to be selected for noncompliance adjustment depends upon available estimates of noncompliance and event rate patterns.

Download Full-text