Effect of continous low-level gamma radiation on the stem and differentiating spermatogonia of the adult rat

Author(s):  
B.H. Erickson
Keyword(s):  
2019 ◽  
Vol 8 (1) ◽  
pp. 53-62
Author(s):  
James Johnston ◽  
Shuwei Yue ◽  
Jeremy Stewart

Nuclear waste management facilities at Chalk River Laboratories (CRL) use below-ground “tile-holes” to store solid waste from various activities such as medical isotope production. After long periods of isotopic decay, some of the waste has decayed down to low activities and can be transferred to low-level waste storage facilities. This paper presents a method to verify the radiation level of the waste inside tile-holes by performing gamma radiation scans along the depth of waste storage tile-holes. Such measurements allow for noninvasive verification of tile-hole contents and provide input to the assessment of radiological risk associated with removal of the waste. Using the radiation profile system, the radiation level of the radioactive waste may be identified based on the radiation profile. This information will support planning for possible transfer of this waste to a licensed waste storage facility designed for low-level waste, thus freeing storage space for possible tile-hole re-use for more highly radioactive waste. CRL-developed small diode-based gamma radiation sensors have been used in these radiation scans. The diode sensors were deployed into verification tubes adjacent to the tile-holes to measure the radiation profile. Over 10 tile-holes have been scanned using this technique since 2009.


Radiocarbon ◽  
1997 ◽  
Vol 40 (1) ◽  
pp. 157-166
Author(s):  
Pall Theodórsson

A recent broad study of the background of all types of low-level beta and gamma detectors has now made it possible to analyze its components more reliably and with greater detail. This general analysis is developed further here for gas proportional and liquid scintillation counters used in radiocarbon dating. The background of gas counters, which is dominated by secondary cosmic gamma radiation, is now well understood and can be described quantitatively. The background of liquid counters is less well understood and can only be described semiquantitatively, its analysis resting partly on estimates. Methods to reduce the background of both types of systems are described and their effectiveness discussed. This analysis may help in evaluating the quality of existing systems as well as in designing better ones.


1985 ◽  
Vol 248 (3) ◽  
pp. E274-E280 ◽  
Author(s):  
T. T. Turner ◽  
L. L. Ewing ◽  
C. E. Jones ◽  
S. S. Howards ◽  
B. Zegeye

The control of androgen concentrations in the intraluminal fluids of the male reproductive tract is not well understood. The present experiments were performed to determine the effects of hypophysectomy, hypophysectomy plus testosterone (T), and hypophysectomy plus pregnenolone treatment on intraluminal androgen concentrations in the adult rat testis and epididymis. T and 5 alpha-dihydrotestosterone (DHT) concentrations were determined in the vascular, interstitial, and intraluminal compartments of the epididymis. Testicular and epididymal morphology also were examined under light microscopy. Hypophysectomy of at least 5 days duration significantly reduced T and DHT concentrations in serum, tissues, and intraluminal fluids of the reproductive tract. T replacement for 14 days, which produced peripheral T concentrations of 5 ng/ml, did not support intraluminal androgen concentrations in the seminiferous tubules equivalent to controls; rete testis androgen concentrations were similar to controls, however. Pregnenolone administration at 2 mg X rat-1 X day-1 for 14 days did not maintain spermatogenesis nor intraluminal T concentrations in the seminiferous tubules equivalent to controls; however, a low level of spermatogenesis continued when intraluminal and tissue androgen concentrations were maintained at 10-20% of controls by either the testosterone and pregnenolone treatments.


1967 ◽  
Vol 32 (1) ◽  
pp. 176
Author(s):  
Joseph A. Watson ◽  
Donald P. Doolittle
Keyword(s):  

2016 ◽  
Vol 9 (11-12) ◽  
pp. 1157-1166 ◽  
Author(s):  
Camila Ramos Silva ◽  
Fernanda Viana Cabral ◽  
Claudinei Francisco Morais de Camargo ◽  
Silvia Cristina Núñez ◽  
Tania Mateus Yoshimura ◽  
...  

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