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The Effects Of Photoperiod And Melatonin Injections On The Reproductive System Of The Male Mongolian Gerbil (Meriones Unguiculatus), Luis Jose Cova Marchan
The Effects Of Photoperiod And Melatonin Injections On The Reproductive System Of The Male Mongolian Gerbil (Meriones Unguiculatus), Luis Jose Cova Marchan
Master's Theses
This work was undertaken to study the effects of photoperiod and melatonin on fertility in male Mongolian gerbils (Meriones unguiculatus). Four groups of fifteen animals each, were placed in different photoperiods (ambient, ranging from 14L:10D to 11.3L:12.3D; 24L:10D; 14L:10D; and 1L:23D). After 35 days, three gerbils from each photoperiod condition were sacrificed and the testes, epididymides, seminal vesicles, prostate, kidneys, adrenals, thymus and hypophysis were weighed. The testes and epididymides were placed in Bouin's fixative and used for histological studies. Also, two males from each photoperiod condition were paired individually with a female. The remaining animals of each photoperiod condition …
The Effects Of Photoperiod And Melatonin Injections On The Reproductive System Of Male Mice, Mus Musculus, Icr Strain, Margaret Ann Shugart
The Effects Of Photoperiod And Melatonin Injections On The Reproductive System Of Male Mice, Mus Musculus, Icr Strain, Margaret Ann Shugart
Master's Theses
The reproductive effects of long (24L:OD), natural (14L:lOD), and short (1L:23D) photoperiods were studied in the male mouse, Mus musculus, ICR strain. One third of the mice in each photoperiodic regimen were sacrificed after 45 days. Half of the remaining mice in each regimen received daily melatonin (5-methoxy-N-acetyl tryptamine) injections for 45 additional days. Body weights, testicular and accessory sex organ weights were measured and microscopic examinations of the testes were made. Plasma testosterone levels were determined using radioimmunoassay. Other organ (pituitary, kidney, adrenal, thymus, thyroid) weights were also obtained.
The Effect Of Photoperiod On The Regressive Phase Of The Ovarian Cycle Of The Lizard, Anolis Carolinensis., John Dickens Pinch
The Effect Of Photoperiod On The Regressive Phase Of The Ovarian Cycle Of The Lizard, Anolis Carolinensis., John Dickens Pinch
Master's Theses
The effects of constant photoperiod (14 hours of light) and decreasing photoperiod (13-8 hours of light) on the regressive phase of the ovarian cycle of the lizard Anolis carolinensis were investigated. Changes in body, liver, ovary and oviduct weights were measured and microscopic examinations of several ovarian parameters were made. In both light regimens body and liver weights decreased over the first four weeks of the experiment but both increased at the sixth week. In addition, ovary weight was highly variable but exhibited a decreasing trend and oviduct weight decreased. There were decreases in the number of previtellogonic follicles and …
The Effect Of Photoperiod On The Diurnal Fluctuations In Photosynthetic Rate Of Two Species Of Marine Phytoplankton, Richard Allmon Smith
The Effect Of Photoperiod On The Diurnal Fluctuations In Photosynthetic Rate Of Two Species Of Marine Phytoplankton, Richard Allmon Smith
Master's Theses
Photosynthetic rates were measured under constant conditions over a 24 hour period for cultures of Skeletonema costatum and Amphidinium carterae grown under various light - dark regimes. Photosynthetic rate fluctuated for both species under all photoperiods except for A. carterase under 8 hours light per day. Maximum photosynthetic rates occurred generally in the middle of the. light period and minimum rates.in the middle of the dark period. The ratio of maximum to minimum rates, or Pmax/min, differed significantly under the various photoperiods. Pmax/min values . for A. carterae were significantly greater than for s. costatum. The greatest Pmax/min for S …