Publications

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comparing the effects of atrazine and an environmentally-relevant mixture on estrogen-responsive gene expression in the northern leopard frog and the fathead minnow.in nebraska, fish are exposed to herbicides in agricultural runoff. study objectives were to determine 1) if fathead minnows and northern leopard frogs exposed to atrazine experience alterations in gene expression, and 2) whether these changes are elicited by a simulated herbicide mixture. following a 7-day exposure to atrazine female minnows were defeminized, while male frogs were feminized. the mixture did not elicit statistically significant effects in either species. this article is protecte ...029314190
rana pipiens. 190717743204
on the chemistry and development of the yolk platelets in the egg of the frog (rana pipiens). 190917788753
cultivation of the skin epithelium of the adult frog, rana pipiens.1. fragments of skin taken from the back of the leopard frog were cultivated in a mixture of plasma and muscle extract of the same species. 2. a few hours after explanation, processes of activity are seen to arise, which finally lead to the formation of a compact epithelial rim around the fragment of skin. 3. these epithelial cells undergo gradual transformation into a spindle-shaped type of cell; in this form they resemble the spindle cells which have been described as connective tissue cells. ...191419867847
the form of the epithelial cells in cultures of frog skin, and its relation to the consistency of the medium.1. fragments of skin from the leopard frog (rana pipiens) were cultivated in media of varying consistency. a mixture of frog plasma, frog muscle extract, chicken plasma, and chicken embryo extract usually produced a very firm medium; a mixture of frog plasma, frog muscle extract, and chicken plasma, one less firm (semi-firm); and a mixture of frog plasma and frog muscle extract a medium of a consistency varying from soft to liquid. 2. (a) in a firm medium the cells which migrate into the medium ...191519867903
changes in pigment epithelium cells and iris pigment cells of rana pipiens induced by changes in environmental conditions.1. retina pigment epithelium cells and iris pigment cells are placed in an identical medium. 2. the differentiation into two different parts, as well as the pigment strains of the migrating pigment epithelium cells, is lost. the normally highly specialized cuticular structures disappear. the cells begin to move and assume a spindle shape, thus losing their original hexagonal shape. 3. the migrating iris pigment cells begin to show a distribution of the pigment, similar to that exhibited by the m ...191619868067
the results of extirpation of the anterior lobe of the hypophysis and of the thyroid of rana pipiens larvae. 191617742316
the effects of thyroid removal upon the development of the gonads in the larvae of rana pipiens. 191717782269
experiments in the transplantation of the hypophysis of adult rana pipiens to tadpoles. 192017732857
adaptation of cutaneous tactile receptors : iv. electrolyte content of frog skin.the potassium content of the skin of rana pipiens is found to be 132 m.g. per cent. this is roughly of the order of magnitude of the content of potassium in nerve. analyses were also made of the skin for na, ca, mg, cl, s, and p.193619872972
demonstration of a hatching secretion in rana pipiens schreber. 193616588102
lipoid substances of the ovary during ova production in rana pipiens. 193816994942
the flicker response contour for the frog.the flicker response contour for the frog rana pipiens exhibits the duplex character typical for most vertebrates. by comparison (under the same conditions of temperature, 21.5 degrees , and light-time fraction, = 0.5), the low intensity section of the f - log i curve is the smallest thus far found. the cone portion of the curve is satisfactorily described by a probability integral. the rod part represents the addition of a small group of sensory effects upon the lower end of the cone curve, fro ...193919873150
anaerobic glycogenolysis in the muscles of rana pipiens living at low temperatures.1. a considerable proportion of r. pipiens caught in the spring and stored without food for several weeks at about 4 degrees c. had gastrocnemii that did not break down glycogen when they contracted anaerobically to complete exhaustion. a smaller number of the same muscles did not produce lactate. 2. there was no evident relation between failure to break down glycogen and the glycogen content of such muscles, some of which had more than 500 mg. of glycogen per 100 gm. of tissue. 3. the hypothesi ...194119873242
kidney stones in rana pipiens tadpoles reared on spinach. 194117809649
electric impedance of the frog egg.electrical impedance measurements were made upon unfertilized and fertilized eggs of the leopard frog, rana pipiens, over a frequency range of 0.05 to 10 kc. average values of 170 ohm cm.(2) were obtained for the plasma membrane resistance of the egg, 2.0 microf/cm.(2) for the plasma membrane capacity, 86 degrees for the phase angle of the membrane, and 570 ohm cm. for the specific resistance of the interior. these values did not change upon fertilization. no spontaneous rhythmical impedance cha ...194219873312
x-ray diffraction studies on frog muscles.1. x-ray diffraction studies of sartorius muscles of rana pipiens were made in a new x-ray diffraction camera which permits exposures of 3 to 6 minutes. the object-film distance can be varied from 20 to 80 mm; the muscle inside the camera can be electrically stimulated while contracting isotonically or isometrically, and can be observed by a special device. after exposures up to 30 minutes (approximately 40,830 r) muscles are still alive and responsive. 2. contrary to the x-ray diffraction patte ...194419873411
action of potassium and narcotics on rectification in nerve and muscle.electrical rectification was demonstrated in whole sartorius muscle and sciatic nerve of rana pipiens and also in the single giant nerve fiber of the northern squid, ommastrephes illecibrossus. it is probably a property of the plasma membrane. rectification decreases reversibly under the influence of increased concentrations of the potassium ion and with chloroform, veratrine sulfate and isoamyl carbamate. no effect was found with lack of calcium, excess calcium, or barium chloride. decrease in ...194419873404
the development of late gastrula explants of rana pipiens in salt solution. 194521010864
a study of the peripheral blood of a metamorphosing anuran (rana pipiens). 194521005545
nitrogen metabolism of rana pipiens during embryonic development. 194620275394
effect of mammalian pituitary gonadotropins on ovulation in the frog, rana pipiens. 194620273829
hybridization between rana palustris and different geographical forms of rana pipiens. 194616578205
incipient intraspecific isolating mechanisms in rana pipiens. 194620985723
incipient intraspecific isolating mechanisms in rana pipiens. 194617247199
studies in the development of frog hybrids; embryonic development in the cross rana pipiens female x rana sylvatica male. 194621022217
the inheritance of nuclear properties which find expression in the first 72 hours of development of rana pipiens, schreber. 194621020536
a study of adrenal cortical tissue in rana pipiens with special reference to metamorphosis. 194621014282
stages in the normal development of rana pipiens larvae. 194621013391
seasonal variation in the gonadotropic potency of dried anterior pituitaries of rana pipiens. 194717821392
effects of sex hormones and thyroxine on hematopoiesis in the frog, rana pipiens. 194718895477
effects of some thyroid-inhibitors upon the development of rana pipiens tadpoles. 194718895461
studies in the development of frog hybrids; competence of the gastrula ectoderm of rana pipiens female crossed with rana sylvatica male hybrids. 194720255212
hybridization between rana pipiens from vermont and eastern mexico. 194716578248
the use of the spectrophotometer for measuring changes in skin reflectance in rana pipiens. 194720342541
effects of pressure on the uterine eggs of rana pipiens. 194720341973
steroid depression in rana pipiens. 194720244200
influence of endocrine factors on hemopoiesis in the adult frog, rana pipiens. 194818889753
the influence of variations in the nucleo-cytoplasmic ratio on the development of haploid embryos of the frog, rana pipiens. 194818934402
changes in the form of the blastopore in blocked gastrulae of rana pipiens. 194818932965
the polar bodies of the frog, rana pipiens. 194818882508
post-fertilization changes in the egg surface of rana pipiens. 194818882483
studies in the development of frog hybrids; inductive ability of the dorsal lip region of rana pipiens female xrana sylvatica male hybrids. 194818863657
the use of the male north american frog, rana pipiens, in the diagnosis of pregnancy. 194818915893
influence of temperature on radio-sensitivity in the frog, rana pipiens. 194818938629
the male frog, rana pipiens, as a new test animal for early pregnancy. 194817791766
the effect of staphylococcal enterotoxin upon the frog, rana pipiens. 194915391733
effect of ddt on functional development of larvae of rana pipiens and fundulus heteroclitus. 194918116441
induction of metastasis of frog carcinoma by increase of environmental temperature.metastasis of the kidney carcinoma of leopard frogs (rana pipiens) has been induced by exposing tumor-bearing animals for approximately 50 days to a constant temperature of 28 degrees c. under these conditions 54 per cent of the frogs developed secondary growths, whereas in groups kept at 18 degrees or at 7 degrees metastatic dissemination was found in only 6 per cent. moreover, at the elevated temperature the metastases were usually more numerous and more widely disseminated; they were also fai ...194918110881
the use of the male leopard frog (rana pipiens) as a pregnancy test animal. 194918110663
effects of pressure on the cleaving eggs of the frog (rana pipiens). 194915410484
the use of the male rana pipiens frog in the diagnosis of pregnancy and the differential diagnosis of abortions. 194915392754
x-radiation of eggs of rana pipiens at various maturation stages. 194918142362
the reliability of the male north american frog (rana pipiens) in the diagnosis of pregnancy. 194918146971
the influence of egg volume on the development of haploid and diploid embryos of the frog, rana pipiens. 194918141501
an appraisal of the male north american frog (rana pipiens) pregnancy test with suggested modifications of the original technique. 194918116321
geographic variation of adaptive characters in rana pipiens schreber. 194918115114
the effect of thiourea on the thyroid gland of the winter frog (rana pipiens) with some observations on the testis. 194918113439
the neuromotor mechanism of the small blood vessels in membranes of the frog (rana pipiens) and the hamster (mesocricetus auratus) with reference to the normal and pathological conditions of blood flow. 195015427652
the male frog (rana pipiens) compared to the female rat as a pregnancy test animal. 195014784112
a rapid method for demonstrating the action of staphylococcus enterotoxin upon rana pipiens. 195014788860
the rana pipiens frog test for pregnancy. 195014796512
an evaluation of the rana pipiens male frog pregnancy test. 195014771169
effect of thiouracil on uptake of radioactive iodine by thyroid gland of summer frogs (rana pipiens). 195015432736
mitosis of the erythrocytes in the circulating blood of rana pipiens. 195014779006
seasonal variation in sensitivity of rana pipiens to chorionic gonadotropin. 195015404902
the male frog, rana pipiens, as a test animal for determining the level of urinary chorionic gonadotrophin during pregnancy. 195015405828
gonadotropic activity of blood serum from hypophysectomized frogs, rana pipiens. 195015409097
the male frog, rana pipiens as a biological test animal for the diagnosis of pregnancy. 195015408501
seasonal variation in the pregnancy test using rana pipiens. 195114885135
inhibition of the gametokinetic response in male "rana pipiens" with adrenolytic drugs. 195114872843
effect of administration of intermedin upon melanin content of the skin of rana pipiens. 195114844386
an investigation of the capacity for cleavage and differentiation in rana pipiens eggs lacking "functional" chromosomes. 195114850653
a study of the expression of the burnsi gene in adult rana pipiens. 195114824422
observations on the use of the male north american frog (rana pipiens) in pregnancy diagnosis. 195114814202
the concentration of riboflavin in the tissues of the embryos, larvae, juveniles, and adults of the frog, rana pipiens pipiens. 195114807721
temperature-pressure studies on the cardiac rate in tissue culture explants from the heart of the tadpole (rana pipiens). 195213011169
use of the male grass frog (rana pipiens) in pregnancy testing. 195214933500
studies on the mechanism of the spermatic release of the male north american frog (rana pipiens). 195214927724
effects of purine and pyrimidine analogues on development of rana pipiens. 195214920451
studies on the mechanism of the spermatic release of the male north american frog (rana pipiens); reaction to various hormones. 195214907864
phosphatase activity in the tissues of the frog, rana pipiens. 195214907823
morphogenesis and metabolism of amphibian larvae after excision of heat. i. morphogenesis of heartless tadpoles of rana pipiens. 195313104999
regular occurrence of the haploid number of chromosomes in mesenchymal cells of the tail tip of rana pipiens tadpoles. 195313111179
the occurrence of regional distribution of perivascular melanophores within the optic lobes of the frog, rana pipiens. 195313092552
radioactive iodine as an indicator of the uptake of iodine by the liver, gastrocnemius, and thyroid of rana pipiens. 195313056588
respiration of the parts of the hybrid gastrula rana pipiens x r. sylvatica. 195313056585
evidence for the termination of neurosecretory fibers within the pars intermedia of the hypophysis of the frog, rana pipiens. 195313016995
effects of ethyl carbamate (urethan) and related compounds on early developmental processes of the leopard frog, rana pipiens. 195413160959
activities of 6-mercaptopurine and related compounds on embryonic and regenerating tissues of rana pipiens. 195414350525
phenol red transport in the pronephros and mesonephros of the developing frog (rana pipiens). 195413233290
analogues of nucleic acid derivatives and the growth and development of rana pipiens. i. the cyclic inhibition of the development of rana pipiens. 195413211750
cytochemical study of the physiological activities in the pars intermedia of rana pipiens. 195413180998
deoxyribonucleic acid content of nuclei in tail mesenchyme of rana pipiens tadpoles. 195513244626
a study of ribonuclease and desoxyribonuclease during the early developmental stages of rana pipiens. 195514391301
effects of temperature, light, and nutrition on the sensitivity of the male rana pipiens to exogenous chorionic gonadotropin. 195514372980
mitotic frequency in normal and regenerating tail tips of rana pipiens embryos. 195514380256
seasonal variation in gastric hydrochloric acid production in rana pipiens. 195514376555
effect of purified gonadotropins upon release of spermatozoa in the frog, rana pipiens. 195514371674
the mesencephalic v nucleus in anurans. i. normal development in rana pipiens. 195514367559
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