ADRENAL WEIGHT IN WILD MALLARD AND DOMESTIC DUCKS AND SEASONAL ADRENAL WEIGHT CHANGES IN THE MALLARD

1965 ◽  
Vol 43 (3) ◽  
pp. 475-487 ◽  
Author(s):  
E. O. Höhn ◽  
A. K. Sarkar ◽  
A. Dzubin
Keyword(s):  
Sex Differences ◽  
Breeding Season ◽  
Adult Female ◽  
Adult Male ◽  
Adrenal Weight ◽  
Adult Males ◽  
Weight Changes ◽  
Domestic Ducks ◽  
Testicular Weight ◽  
Wild Mallard

Mallards and domestic ducks are conspecific. Relative adrenal weight is similar in newly hatched mallards and domestic ducks. Immature mallards have higher relative adrenal weights than domestic ducks of similar age. Adult female mallards also have higher relative adrenal weights and a higher proportion of cortex in the adrenal than adult female domestic ducks, but adult males of the two strains fail to show these differences.Adrenal weight is related to testicular weight in mallards and domestic ducks, but no correlation is evident between adrenal weight and weight of the ovary and oviduct in mallards. Mallards show no adrenal weight sex differences at any of the three ages sampled. A seasonal adrenal weight cycle is apparent in both sexes of the mallard with a weight increase related to the breeding season and another increase during the autumn and winter.The higher relative adrenal weights of (immature and adult female) mallards compared to those of domestic ducks are attributed to the mallards' greater exposure to stress. It is suggested that this effect operates also in adult male mallards but is obscured in the comparison with adult male domestic ducks because in the latter, which have much higher testicular weights, another factor responsible for the correlation between adrenal and testicular weight as noted above makes for increased adrenal weights.

Effects of adults on survival and recruitment of Peromyscus leucopus

1987 ◽  
Vol 65 (10) ◽  
pp. 2519-2523
Author(s):  
Gregory H. Adler ◽  
Mark L. Wilson ◽  
Michael J. DeRosa
Keyword(s):  
Adult Female ◽  
Adult Male ◽  
Peromyscus Leucopus ◽  
Survival Rates ◽  
Adult Males ◽  
Control Grid ◽  
Young Males ◽  
Young Females ◽  
Breeding Seasons ◽  
And Control

A population of Peromyscus leucopus (white-footed mouse) in northeastern Massachusetts was manipulated for 3 years to determine the effects of adults on survival and recruitment. Two experimental grids were established, from which either all adult males or all adult females were removed continually. The effects of these two manipulations were compared with demography on a control grid. Manipulations had no apparent effect on breeding intensity of young, survival rates of adults, or residency rates of adults and young. Recruitment of adult males was higher on the adult male removal grid than on the control grid. Recruitment rates of adult males and of young males and young females were lower on the adult female removal grid than on the control grid. Survival rates of young males were higher on the adult female removal grid than on the control grid; this effect may have been due to either reduced adult female residency or adult male recruitment. All differences between experimental and control grids were noted only during breeding seasons. Adult males apparently limited recruitment of adult consexuals. The effects of manipulations on other measured parameters were inconclusive because of high immigration rates of adult males onto the adult male removal grid and reduced recruitment of adult males and decreased production of young on the adult female removal grid.

EFFECT OF SEX AND AGE AT GONADECTOMY ON THE SEBACEOUS RESPONSE TO PROGESTERONE

1977 ◽  
Vol 73 (1) ◽  
pp. 67-70 ◽  
Author(s):  
SAM SHUSTER ◽  
WENDY M. HINKS ◽  
A. J. THODY
Keyword(s):  
Adult Female ◽  
Adult Male ◽  
Female Rats ◽  
Male Rats ◽  
Adult Males ◽  
Adult Rat ◽  
Sebum Production ◽  
Males And Females ◽  
Sebum Secretion

SUMMARY The effect of progesterone on the rate of sebum secretion was examined in intact and gonadectomized rats. In intact, adult, male rats, progesterone administered for 3 weeks decreased sebum secretion; after castration of adult males, progesterone increased sebum secretion and an even greater response occurred in males castrated at 21 days of age. In intact, adult, female rats progesterone slightly increased sebum production. As in the male, the response was affected by the time of gonadectomy, a greater response occurring after spaying at 21 days compared with 10 weeks of age. Thus, the response to progesterone in the adult rat differs in intact males and females and is affected by changes in the endocrine environment induced by gonadectomy, especially near the time of puberty.

scholarly journals Adult male coatis play with a band of juveniles

2013 ◽  
Vol 73 (2) ◽  
pp. 353-355 ◽  
Author(s):  
CJ Logan ◽  
JT Longino
Keyword(s):  
Costa Rica ◽  
Breeding Season ◽  
Adult Male ◽  
Model System ◽  
Adult Males ◽  
La Selva ◽  
Biological Station ◽  
Nasua Narica ◽  
Adult Females ◽  
Post Hoc

This study examined the play behaviour in one group of coatis (Nasua narica) at La Selva Biological Station in Costa Rica. We incidentally found adult males playing with juvenile coatis, and conducted post-hoc analyses to investigate this interaction. Coati groups consist of adult females and juveniles of both sexes until male juveniles reach two years of age and leave the band to become solitary. Adult males only tolerate juveniles for a brief period during breeding season when the males court females to mate. Outside of the breeding season, adult males are known to prey on juveniles. In this study, when adult males were present with the band, play occurred more than was expected by chance, and adult males engaged in many of these play bouts. Because the mechanisms driving infanticidal behaviour are not well understood, and adult male coatis show a range of behaviours from infanticide to highly affiliative interactions with juveniles, using coatis as a model system may elucidate mechanisms underlying infanticide.

Short-term association patterns of humpback whale (Megaptera novaeangliae) groups on their feeding grounds in the southern Gulf of Maine

1991 ◽  
Vol 69 (12) ◽  
pp. 3005-3011 ◽  
Author(s):  
Mason T. Weinrich ◽  
Anne E. Kuhlberg
Keyword(s):  
Group Size ◽  
Adult Female ◽  
Adult Male ◽  
Gulf Of Maine ◽  
Humpback Whale ◽  
Distinct Pattern ◽  
Megaptera Novaeangliae ◽  
Adult Males ◽  
Feeding Ground ◽  
Social Nature

Humpback whale (Megaptera novaeangliae) feeding ground associations show a distinct pattern of group size and composition. Median group size was 2 (mean 1.67), and frequency decreased as group size increased. Adult females and juvenile males were observed in pairs significantly more often than singly, whereas adult males and juvenile females were more often alone. Adult female–female pairs occurred significantly more frequently than adult male–male pairs, and adult female – juvenile male pairs formed more frequently than adult male – juvenile female pairs. The majority of groups remained associated for at least 10 min; however, as the size of a group increased, so did its tendency to separate within that period. Adult male–male pair associations were of significantly shorter duration than female–female or male–female pair associations. It is hypothesized that adult males may avoid other males on the feeding ground as an extension of breeding competition. The energetic burden of reproduction, and hence the need to forage cooperatively to maximize efficiency, may account for the adult female's social nature. Juveniles of both sexes, less constrained by reproductive costs, exhibit less structured social behavior.

scholarly journals Endocrine regulation of sex differences in hepatic histidase activity

1985 ◽  
Vol 231 (3) ◽  
pp. 785-787 ◽  
Author(s):  
C A Lamartiniere
Keyword(s):  
Sex Differences ◽  
Adult Female ◽  
Adult Male ◽  
Pituitary Hormones ◽  
Female Rats ◽  
Male Rats ◽  
Endocrine Regulation ◽  
Pituitary Glands

Hepatic histidase activity in adult female rats is twice that in adult male rats. Hypophysectomy and thyroidectomy result in a significant increase in hepatic histidase activities in males, but not in females. This effect on histidase is reversed by the exogenous administration of tri-iodothyronine, but not by ectopic pituitary glands or purified pituitary hormones.

CORTICOSTEROID-UMSATZ UND CORTICOSTEROID-PRODUKTION BEI RATTEN UNTER DER BEHANDLUNG MIT ANABOLEN STEROIDEN

1965 ◽  
Vol 48 (2) ◽  
pp. 263-271 ◽  
Author(s):  
Herbert Schriefers ◽  
Gerlinde Scharlau ◽  
Franzis Pohl
Keyword(s):  
Production Rate ◽  
Adult Female ◽  
Anabolic Steroids ◽  
Reduction Rate ◽  
Female Rats ◽  
Adrenal Weight ◽  
Hydrogenase Activity ◽  
Anabolic Effect ◽  
Liver Slices

ABSTRACT After the administration of anabolic steroids to adult female rats in daily doses of 1 mg per animal for 14 days, the following parameters were investigated: the rate of the Δ4-5α-hydrogenase-catalyzed cortisone reduction in liver slices and microsomal fractions, the adrenal weight and the in vitro corticosterone production rate. Among the steroids tested, only 17α-methyl-testosterone and 17α-ethyl-19-nor-testosterone were effective in lowering significantly cortisone reduction rate by liver slices with concomitant decreases in microsomal Δ4-5α-hydrogenase-activity. Testosterone, 19-nor-testosterone, 17α-ethinyl-19-nor-testosterone, 17α-methyl-17β-hydroxy-androsta-1,4-dien-3-one and 1-methyl-17β-hydroxy-androst-1-en-3-one were ineffective or only slightly effective. Adrenal weight and absolute corticosterone production rate (μg/60 min per animal) were decreased after treatment with 17α-methyl-testosterone, 17α-ethyl-19-nor-testosterone and 1-methyl-17β-hydroxy-androst-1-en-3-one. Corticosterone production was decreased with 17α-ethinyl-19-nor-testosterone in spite of an unchanged adrenal weight. The relative corticosterone production rate (μg/60 min · 100 mg adrenal) was in any cases unaffected. According to these results there exists – with the exception of 17α-ethinyl-19-nor-testosterone – a strict parallelism between corticosteroid turnover and corticosterone production rate: unchanged turnover is correlated with unchanged corticosterone production rate, while a decreased turnover is correlated with decreased adrenal activity. The protein-anabolic effect of certain anabolic steroids may be partly due to an anti-catabolic action of these compounds resulting from a decreased corticosteroid inactivation and production rate. Possible mechanisms by which anabolic steroids may affect corticosteroid-balance are discussed.

HAPTEN-RADIOIMMUNOASSAY OF PLASMA OESTRADIOL

1973 ◽  
Vol 72 (2) ◽  
pp. 330-344 ◽  
Author(s):  
Peter Doerr
Keyword(s):  
Adult Male ◽  
Normal Values ◽  
Normal Adult ◽  
Adult Males ◽  
Reagent Blank ◽  
Keyhole Limpet Haemocyanin ◽  
Ether Extraction ◽  
The Mean ◽  
Assay Precision ◽  
Plasma Oestradiol

ABSTRACT A hapten-radioimmunoassay for plasma oestradiol is described and information about the reliability of the method is given in detail. Oestradiol-3-hemisuccinate coupled to keyhole limpet haemocyanin is used for immunization of rabbits. The antiserum utilized for the assay is characterized by its titer, affinity and specificity. Following ether extraction and NaOH-light petroleum partition oestradiol is separated from crossreacting oestrogens by TLC. Oxidation of oestradiol on the plate is prevented by mercaptoethanol. To separate free and antibody bound ligand 250 μg dextran-coated charcoal per tube is used in the presence of bovine serum gammaglobulin (1 mg/ml). The between-assay precision based on 15 different determinations of control samples from normal adult male plasma was 9.4% (C. V.). The mean reagent blank value of 31 determinations was equivalent to 0.3 pg oestradiol and the detection limit in terms of the 99% confidence limit for a single blank value, was equivalent to 4.3 pg oestradiol. A procedure for detecting plasma blanks is described. Plasma oestradiol is separated from approximately all concomitant substances originally present in the sample by enzymatic conversion into oestrone and a second TLC. No plasma blanks could be detected with respect to normal adult male plasma. Normal values for adult males based on 51 subjects were characterized by a median of 17.2 pg/ml and the 95 percentiles of 9.5–27.6.

Bonobo baby dominance: Did female defense of offspring lead to reduced male aggression?

2018 ◽  
Author(s):  
Kara Walker ◽  
Brian Hare
Keyword(s):  
Adult Male ◽  
Social System ◽  
Dominant Species ◽  
Potential Solution ◽  
Adult Males ◽  
Male Aggression ◽  
Dominance Style ◽  
The Social ◽  
Initial Support

The dominance style of bonobos presents an evolutionary puzzle. Bonobos are not male dominant but female bonobos do not show traits typical of female-dominant species. This chapter proposes the offspring dominance hypothesis (ODH) as a potential solution. ODH suggests the social system of bonobos evolved as a defence against infanticide and is not due to pressure to monopolize resources. Females that prevented aggression towards offspring and preferred mating with less aggressive males were most successful. Supporting ODH, during observations at Lola ya Bonobo Sanctuary it was found that: 1) adult male bonobos are rarely aggressive towards offspring with mothers, 2) some mother-reared juvenile bonobos attain rank higher than adult males and 3) mother-reared offspring often socially interact with adult males without their mothers nearby. These preliminary findings provide initial support that the bonobo social system evolved due to fitness advantages of effectively protecting offspring against consequences of male aggression. Le style de dominance des bonobos présente un puzzle évolutionnaire. Les bonobos ne sont pas dominés par les mâles mais les bonobos femelles ne montrent pas les traits caractéristiques d’une espèce dominée par femelles. On propose l’hypothèse de dominance de progéniture (ODH) comme une solution potentielle. La ODH suggère que le système social des bonobos a évolué en défense contre l’infanticide et pas sous pression pour la monopolisation des ressources. Les femelles qui préviennent l’agression vers leur progéniture et leur préférence d’accouplement avec des mâles moins agressives étaient très efficaces. À l’appui de la ODH on a trouvé pendant nos observations à Lola ya Bonobo Sanctuary que: 1) les mâles adultes bonobos agressent rarement vers les bébés avec mères, 2) quelques adolescents bonobos qui furent élevés par leurs mères atteignent un rang plus haut que les mâles adultes et 3) la progéniture élevée par la mère interagissent avec avec d’adultes mâles sans la présence de leur mère. Ces trouvailles préliminaires donnent appuie à l’hypothèse que le système social des bonobos a évolué par les avantages corporelles de la protection de la progéniture contre les conséquences de l’agression mâle.

scholarly journals Sex Difference in Self-Reported Sexual Functioning Among Frail Older Adults

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 313-313
Author(s):  
Brianne Olivieri-Mui ◽  
Sandra Shi ◽  
Ellen McCarthy ◽  
Dae Kim
Keyword(s):  
Older Adults ◽  
Logistic Regression ◽  
Sex Differences ◽  
Sexual Function ◽  
Older Adult ◽  
Sexual Functioning ◽  
Social Life ◽  
Well Being ◽  
Adult Males ◽  
Males And Females

Abstract Frailty may differentially impact how older adult males and females perceive sexual functioning, an important part of well-being. We assessed the level of frailty (robust, pre-frail, frail) for anyone with data on 11 sexual functioning questions asked in wave 2 of the National Social Life, Health, and Aging Project, 2010-2011 (n=2060). Questions covered five domains: overall sexual function (OSF), sexual function anxiety (SFA), changes in sexual function (CSF), erectile/vaginal dysfunction (EVD), and masturbation. Logistic regression identified sex differences in frailty and reporting worse sexual functioning. Linear regression predicted the number of domains reported as worse. Among males (n=1057), pre-frailty meant higher odds of reporting SFA (OR 1.8 95%CI 1.2-6.6), CSF (OR 1.7 95%CI 1.1-2.7), and EVD (OR 1.5 95%CI 1.0-2.2). Among females (n=1003), there was no difference in reporting by frailty. Females were more likely to report worse OSF (Robust: OR 7.4, 95%CI 4.8-11.4; Pre-frail: OR 6.2, 95%CI 3.9-9.9; Frail: OR 3.4 95%CI 1.7-6.6), but less likely to report SFA (Robust OR .3, 95%CI .2-.5; Pre-frail OR .2, 95%CI .1-.3; Frail OR .2 95%CI .1-.3). Pre-frail and frail females reported fewer domains as worse (Pre-frail coefficient -0.21 SE 0.09, Frail -0.43 SE 0.14). As frailty worsened, males reported more domains as worse (Pre-frail 0.24 SE 0.07, Frail 0.29 SE 0.08). Self-reported sexual functioning differs by sex at all levels of frailty, and reporting by males, but not females, changes with frailty. Providers should be aware that sexual functioning is of importance to both sexes despite varying degrees of frailty.

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