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1.
Rev Sci Instrum ; 78(1): 016104, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17503953

RESUMO

Water and ice were investigated by ac impedance with the electrochemical properties cup in an effort to develop an in situ instrument for water characterization. In liquid water, the impedance modulus decreased with the increase in charge carriers. In the ice, the impedance measurements were characterized by the dielectric relaxation and its corresponding activation energy. The activation energy of 0.400 eV was determined for pure ice. With ice containing Cl(-) anions, the activation energy was 0.24 eV. H(+) and OH(-) doped ice has the lowest activation energy for dielectric relaxation. Results from previous works are similar to the results reported in this study.


Assuntos
Cloretos/análise , Eletroquímica , Gelo/análise , Ânions/análise , Impedância Elétrica , Eletroquímica/instrumentação
2.
Physiol Behav ; 31(3): 293-7, 1983 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6685325

RESUMO

In simultaneous choice tests male beagles were allowed to visit a caged female in estrus, or caged, spayed female not in estrus. Males were tested periodically from 1-3 to 22-24 months of age. The 3 subject groups were normal males (Group N), males castrated 4-7 days postpartum and injected with testosterone propionate (TP) until they were 3 months old (Group TPTC), and males castrated 4-7 days but given no hormone treatment, i.e., untreated castrates (Group UC). A statistically reliable preference for visiting the estrous rather than the nonestrous female first appeared in N males at 4-6 months, in TPTC males at 1-3 months, and in UC males at 10-12 months. In N males attraction to the estrous female (measured by time spent visiting her) increased progressively from 4-6 to 16-18 months. In the same period concentration of plasma testosterone rapidly increased, reached a peak at 10-12 months, and then declined. UC males exhibited no significant increase in attraction to the estrous female from 10-12 months (when a preference first appeared) to 22-24 months. They then received 10 injections of TP after which their visiting time to the estrous female was equal to that of N males. TPTC males exhibited a precocious preference for the estrous female at 1-3 months, while they were receiving TP, and there was no decrease in strength of attraction in the following 9 months during which time no hormone was administered. Between 10-12 and 13-15 months, still without exogenous androgen, visiting to the estrous female began to increase and continued to do so until 19-21 months.


Assuntos
Cães/fisiologia , Estro , Comportamento Sexual Animal/fisiologia , Animais , Castração , Feminino , Masculino , Gravidez , Comportamento Sexual Animal/efeitos dos fármacos , Testosterona/sangue , Testosterona/farmacologia
3.
Behav Neural Biol ; 38(1): 1-31, 1983 May.
Artigo em Inglês | MEDLINE | ID: mdl-6354173

RESUMO

This experiment was conducted to study hormonal and behavioral cycles in female dogs exposed to androgen during development. The four groups, each consisting of five subjects, were "Normal" females, "Prenatal" females exposed to testosterone propionate (TP) before birth, "Postnatal" females injected with TP for 3 months postpartum, and "Prepost" females exposed to TP in utero and again to testosterone for 4--6 weeks after birth. All Normal females had two estrous cycles during which they showed vaginal bleeding, ovulation, progesterone (P) secretion, sexual receptivity, and were attractive to males. All androgen-treated females showed at least 1 cycle with ovulation and P secretion. Three Postnatal females developed the delayed anovulatory syndrome. Genital bleeding through the vagina (Postnatal group), or through the "penis" (Prenatal and Prepost groups), occurred in 4 Postnatal, 3 Prenatal, and 1 Prepost female. Attractiveness for males was observed in all Prenatal and Postnatal females, but in no Prepost subject. Receptivity was present in four of five Prenatal females but not in any Postnatal or Prepost female. Occurrence of cycles in treated females indicated functional integrity and sensitivity to estrogen in brain mechanisms producing gonadotropin-releasing hormones. Absence of receptivity is referred to diminished responsiveness to ovarian hormones in brain mechanisms mediating receptive behavior. Absence of genital bleeding and lack of attractivity are due to lowered response to estrogen in uterine and vaginal epithelium which results in reduced extravasation of blood, and in failure to secrete the putative "pheromonal" agent normally responsible for attractiveness.


Assuntos
Estro/efeitos dos fármacos , Comportamento Sexual Animal/efeitos dos fármacos , Testosterona/farmacologia , Animais , Cães , Feminino , Genitália Feminina/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/metabolismo , Masculino , Ovário/efeitos dos fármacos , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Progesterona/sangue , Diferenciação Sexual/efeitos dos fármacos
4.
J Comp Physiol Psychol ; 96(6): 855-74, 1982 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7153384

RESUMO

Male, spayed female, and pseudohermaphroditic female dogs were tested in pairs for competition over a large bone. Pseudohermaphroditic females had been exposed to testosterone proprionate before and immediately after birth. Two types of tests were used. In equal opportunity tests (EO tests), both members of a pair had equal chance to seize the bone when it was tossed into the arena. Each EO test was followed by an established possession test (EP test). During an EP test, the loser of the preceding EO test was given possession of the bone before the former winner was returned to the test arena. Every dog was tested against all other members of its own and both of the other groups. Males won 78 of 100 EO tests against normal females but only 61 of 100 against pseudohermaphroditic females. Pseudohermaphroditic females won 70 of 100 EO tests against normal females. When either normal or pseudohermaphroditic females were given possession of the bone in EP tests they were equally ineffective in defense against male challengers, losing 75% and 71% of their tests, respectively. Both types of females were much more successful in defending possession during EP tests against each other than they had been against males. When normal and pseudohermaphroditic females were treated with testosterone propionate, their performance in competition tests was not altered. Androgenic stimulation before and immediately after birth permanently modified the social behavior of pseudohermaphroditic females as well as the behavior of males and normal females toward the experimental dogs. However, the changes could not appropriately be described as "masculinization." Developmentally androgenized females differed from members of their own sex, but they differed just as greatly from normal males.


Assuntos
Comportamento Competitivo/efeitos dos fármacos , Transtornos do Desenvolvimento Sexual/psicologia , Caracteres Sexuais , Testosterona/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Comportamento Competitivo/fisiologia , Cães , Feminino , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Predomínio Social , Testosterona/sangue
6.
Rev Sci Instrum ; 50(8): 983-7, 1979 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18699649

RESUMO

This paper describes the design, construction, and characterization of a variable-temperature wafer apparatus for use in the detection of electrically active defects which produce deep levels in the band gap of silicon. In its present form, the wafer chuck can heat and cool wafers as large as 51 mm in diameter over the temperature range from -196 degrees to 350 degrees C. Heating rates as high as 7 degrees C/s have been achieved. Sensitivity for electrical measurements is sufficient to allow current measurements as low as 0.2 pA or capacitance changes (1 MHz) as small as 5 fF. The use of this apparatus is illustrated by wafer mapping the gold defect density in diodes fabricated across a silicon wafer.

7.
Endocrinology ; 100(1): 197-200, 1977 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-830539

RESUMO

Pseudohermaphroditic Stanley-Gumbreck male rats showed infrequent and incomplete copulatory responses to receptive females. Administration of testosterone propionate produced no increase in this behavior. Injections of estradiol and progesterone induced the pseudohermaphrodites to exhibit lordosis when mounted by stimulus males, but feminine responses were no more frequent than those of normal males given the same hormonal treatment. The hypothesis is suggested that early in development sufficient endogenous testis hormone is produced to cause normal desensitization of feminine behavioral mechanisms to estradiol, but that mechanisms for male behavior are not normally sensitized to testosterone.


Assuntos
Copulação/fisiologia , Transtornos do Desenvolvimento Sexual/fisiopatologia , Testosterona/farmacologia , Animais , Copulação/efeitos dos fármacos , Transtornos do Desenvolvimento Sexual/genética , Estradiol/farmacologia , Masculino , Postura/efeitos dos fármacos , Progesterona/farmacologia , Ratos
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