Keiko Shimizu
Biographic Data
| ID | 4146355 |
|---|---|
| NAME | Keiko Shimizu |
| GIVEN NAMES | Keiko |
| FAMILY NAME | Shimizu |
| SIGNATURE | SHIMIZU K |
| AFFILIATIONS | Kyoto University |
| ORCID | 0000-0002-5180-7424 |
| VERIFIED | Yes |
| TOTAL WORKS | 30 |
| TOTAL CITATIONS | 21 |
| AUTHOR COUNT | 30 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1987 |
| LATEST PUBLICATION YEAR | 2023 |
| H-INDEX | 4 |
Mothers of disabled infants had higher cortisol levels in a free‐ranging group of Japanese macaques ( Macaca fuscata )
Glucocorticoids (GCs) are hormones released in response to stressors and can provide insight into an organism's physiological well‐being. Experiencing chronic challenges to homeostasis is associated with significant deviations from baseline fecal GCs (fGCs) in many species, providing a noninvasive biomarker for assessing stress. In the group of free‐ranging Japanese macaques ( Macaca fuscata ) at the Awajishima Monkey Center in Japan, ~17% have c…
Physical, behavioral, and hormonal changes in the resumption of sexual receptivity during postpartum infertility in female bonobos at Wamba
The operational sex ratio (OSR) is used as a predictor for the intensity of mating competition. While many factors affect the OSR, there tends to be a high male bias in primate species with long interbirth intervals and non-seasonal breeding, such as hominid apes. However, the OSR of bonobos ( Pan paniscus ) is lower than that of chimpanzees ( Pan troglodytes ), which is thought to reduce competitive and aggressive male behaviors. The low OSR of …
Stability of chimpanzee (Pan troglodytes) urinary reproductive hormones during long-term preservation on filter paper
Coital Frequency and the Probability of Pregnancy in Couples Trying to Conceive Their First Child: A Prospective Cohort Study in Japan
Background : Low fertility persists but remains unexplained in Japan. We examined whether the probability of pregnancy was influenced by coital frequency, age, reproductive age (assessed by antimüllerian hormone, AMH), and BMI. Methods: We established a two-year prospective study with a sample of hormonally monitored Japanese women aged 23-34 years wanting to conceive their first child. For a maximum of 24 weeks participants recorded menstrual bl…
Testing for links between face color and age, dominance status, parity, weight, and intestinal nematode infection in a sample of female Japanese macaques
Environmental, biological, and social factors influencing fecal adrenal steroid concentrations in female Japanese macaques ( Macaca fuscata )
The ability to determine hormonal profiles of primate populations using non-invasive techniques can help to monitor physical fitness, stress, and physiological responses to environmental changes. We investigated fecal glucocorticoids (fGC) and DHEAS concentrations in captive Japanese macaques (Macaca fuscata) in relation to environmental, biological, and social factors. The subjects were female Japanese monkeys from 4 months to 31 years old house…
Energetic consequences of seasonal breeding in female Japanese macaques ( Macaca fuscata )
Japanese macaques inhabit a relatively cold environment and females of this species could have developed strategies of energy economy to face the sometimes‐harsh seasonal conditions of temperate climates, as well as reproductive costs, and thus regulate their energy balance. Here, we explore the relationship between nutritional status, body composition, seasonality, and reproductive status using isotope‐labeled water, anthropometric measurements,…
Seasonal and reproductive variation in body condition in captive female Japanese macaques ( Macaca fuscata )
The geographic distribution of Japanese macaques includes populations with the most northern range of any primate species. Not surprisingly, females of this species are characterized by physiological adaptations and unique fat deposition mechanisms that facilitate their survival through the sometimes‐harsh seasonal conditions of temperate climates, as well as sustaining the metabolic costs of mating, pregnancy, and lactation. Here, we explore the…
Birth in Free-ranging Macaca fuscata
Relationship between sexual interactions and the timing of the fertile phase in captive female Japanese macaques ( Macaca fuscata )
Japanese macaques live in multi‐male/multi‐female social groups in which competition between males, female mate choice, and alternative male mating strategies are important determinants of mating and reproductive success. However, the extent to which adult males rely on female behavior to make their mating decisions as well as the effect of social rank on mating success are not clear as results are inconclusive, varying from study to study. In th…
Seasonal variation in fecal testosterone levels in free‐ranging male Japanese macaques
Seasonal variation in fecal testosterone levels in free‐ranging male Japanese macaques ( Macaca fuscata ) was examined with reference to their dominance rank and age class. Six adult (≥7 years old, three higher‐ranking and three lower‐ranking) and four adolescent (5–6 years old, two higher‐ranking and two lower‐ranking) males were selected as target animals. Fecal samples of these males were collected during the first 3–5 days of each month and a…
Hormone profiles and reproductive characteristics in wild female Japanese macaques ( Macaca fuscata )
In this study we investigated the reproductive characteristics of wild female Japanese macaques ( Macaca fuscata fuscata ) in 2 nonconsecutive years using noninvasive methods to monitor physiological events. We detected ovulation dates and ascertained conceptions from fecal hormone profiles. First ovulations occurred from middle October to early November in 1997, and from middle to late November in 1999. Most females conceived during their first …
Comparative study of urinary reproductive hormones in great apes
Mother–infant relationships and maternal estrogen metabolites changes in macaques (Macaca fuscata, M. mulatta)
Inhibin B is the major form of inhibin secreted from testes in male Japanese macaques ( Macaca fuscata )
Levels of serum brain-derived neurotrophic factor in primates
Peripartum cortisol levels and mother‐infant interactions in Japanese macaques
As evidence accumulates regarding the influence of hormones and stress‐related conditions on maternal behavior, it becomes critical to better understand the relationship between physiological stress and the ability to cope with infants. Eight Japanese macaque females were observed 3 hr per week during the first 12 weeks after parturition; fecal samples were collected twice a week from each mother, starting 4 weeks before parturition and ending 4 …
Fecal testosterone immunoreactivity as a non-invasive index of functional testosterone dynamics in male Japanese macaques (Macaca fuscata)
Noninstrumented enzyme‐linked immunosorbant assay for detection of early pregnancy in macaques
A practical, noninstrumented enzyme‐linked immunosorbant assay (NELISA) for the measurement of urinary monkey chorionic gonadotropin (mCG) has been developed for the detection of early pregnancy in macaque monkeys for use in both the laboratory and the field. Five rhesus monkeys ( Macaca mulatta ) and six crab‐eating monkeys ( Macaca fascicularis ) were tested for the presence of mCG in urine on gestational days (GDs) 12 to 35. The mCG NELISA det…
Measurement of urinary and fecal steroid metabolites during the ovarian cycle in captive and wild Japanese macaques, Macaca fuscata
We measured the concentration of steroid hormones from urine, feces, and blood samples of two captive Japanese macaques, Macaca fuscata , during nonconceptive ovarian cycles to compare the patterns of the excreted steroids with those of circulating steroids. Urine and feces were analyzed for estrone conjugates (E 1 C) and pregnanediol‐3‐glucronide (PdG) using enzyme immunoassays (EIAs), while plasma was analyzed for estradiol‐17β(E 2 ), progester…
Hormonal Correlates of Maternal Style in Captive Macaques (Macaca fuscata and M. mulatta)
Pituitary–adrenocortical responses to the first dyadic encounters in male rhesus monkeys: Effect of dominance relationship
Male rhesus monkeys unfamiliar with each other were paired in a cage, and blood samples were collected before and a few hours after pair formation. Adrenocorticotrophic hormone (ACTH) and cortisol levels in each blood sample were measured. Dominant–subordinate status was ascertained through two rank tests, the food competition test and the agonistic behavior test, which were performed immediately after pair formation. As a result, the dominance r…
Pituitary-adrenocortical responses to the first dyadic encounters in male rhesus monkeys: Effect of dominance relationship
Male rhesus monkeys unfamiliar with each other were paired in a cage, and blood samples were collected before and a few hours after pair formation. Adrenocorticotrophic hormone (ACTH) and cortisol levels in each blood sample were measured. Dominant-subordinate status was ascertained through two rank tests, the food competition test and the agonistic behavior test, which were performed immediately after pair formation. As a result, the dominance r…
Female mating strategy in an enclosed group of Japanese macaques
Female Japanese macaques (Macaca fuscata) are noted for mating with multiple males and for their ability to exert mate choice. In a captive group of Japanese macaques housed at the Primate Research Institute of Kyoto University, Japan, behavioral and endocrine data were combined to examine female mating strategies. During one breeding season, daily behavioral observations were conducted on females who exhibited copulatory behavior. Blood was coll…
Age-related changes in ovarian morphology from birth to menopause in the Japanese monkey,Macaca fuscata fuscata
Peripartum cortisol levels and mother‐infant interactions in Japanese macaques
As evidence accumulates regarding the influence of hormones and stress‐related conditions on maternal behavior, it becomes critical to better understand the relationship between physiological stress and the ability to cope with infants. Eight Japanese macaque females were observed 3 hr per week during the first 12 weeks after parturition; fecal samples were collected twice a week from each mother, starting 4 weeks before parturition and ending 4 …
Birth in Free-ranging Macaca fuscata
Hormonal Correlates of Maternal Style in Captive Macaques (Macaca fuscata and M. mulatta)
Sexual Maturation of Female Japanese Macaques Under Poor Nutritional Conditions and Food-Enhanced Perineal Swelling in the Koshima Troop
Formation of a mental abacus for computation and its use as a memory device for digits: A developmental study
In order to examine whether representational changes in digit memory would be observed as a function of the extent of expertise in mental-abacus operation, five groups of operators, differing in extent of expertise (i.e., novices, lower intermediates, intermediates, junior experts, and experts), were required (a) to reproduce series of five digits either forward or backward as quickly as possible and (b) to perform a simple aural-verbal or visual…
Energetic consequences of seasonal breeding in female Japanese macaques ( Macaca fuscata )
Japanese macaques inhabit a relatively cold environment and females of this species could have developed strategies of energy economy to face the sometimes‐harsh seasonal conditions of temperate climates, as well as reproductive costs, and thus regulate their energy balance. Here, we explore the relationship between nutritional status, body composition, seasonality, and reproductive status using isotope‐labeled water, anthropometric measurements,…
Formation of a mental abacus for computation and its use as a memory device for digits: A developmental study
In order to examine whether representational changes in digit memory would be observed as a function of the extent of expertise in mental-abacus operation, five groups of operators, differing in extent of expertise (i.e., novices, lower intermediates, intermediates, junior experts, and experts), were required (a) to reproduce series of five digits either forward or backward as quickly as possible and (b) to perform a simple aural-verbal or visual…
Male dominance rank and reproductive success in an enclosed group of Japanese macaques: With special reference to post-conception mating
Suppressed copulatory behavior and ovarian function in lactating Japanese monkeys (Macaca fuscata fuscata) during the mating season
Cluster Formation of Basal-Granulated Cells in the Intestinal Villi of the Fetal Japanese Monkey (Macaca fuscata fuscata)
Segi's cap, an aggregation of the basal-granulated cells in the intestinal villi of the fetal Japanese monkey was investigated by means of light microscopy and immunocytochemical techniques. Characteristic Segi's caps were observed at the tips of the villi in the duodenum and upper jejunum in fetal Japanese monkeys, aged 120 and 140 days. The Segi's cap of Japanese monkeys is characterized by the following morphological features: 1) There are rel…
Age-related changes in ovarian morphology from birth to menopause in the Japanese monkey,Macaca fuscata fuscata
Sexual Maturation of Female Japanese Macaques Under Poor Nutritional Conditions and Food-Enhanced Perineal Swelling in the Koshima Troop
Female mating strategy in an enclosed group of Japanese macaques
Female Japanese macaques (Macaca fuscata) are noted for mating with multiple males and for their ability to exert mate choice. In a captive group of Japanese macaques housed at the Primate Research Institute of Kyoto University, Japan, behavioral and endocrine data were combined to examine female mating strategies. During one breeding season, daily behavioral observations were conducted on females who exhibited copulatory behavior. Blood was coll…
Pituitary–adrenocortical responses to the first dyadic encounters in male rhesus monkeys: Effect of dominance relationship
Male rhesus monkeys unfamiliar with each other were paired in a cage, and blood samples were collected before and a few hours after pair formation. Adrenocorticotrophic hormone (ACTH) and cortisol levels in each blood sample were measured. Dominant–subordinate status was ascertained through two rank tests, the food competition test and the agonistic behavior test, which were performed immediately after pair formation. As a result, the dominance r…
Pituitary-adrenocortical responses to the first dyadic encounters in male rhesus monkeys: Effect of dominance relationship
Male rhesus monkeys unfamiliar with each other were paired in a cage, and blood samples were collected before and a few hours after pair formation. Adrenocorticotrophic hormone (ACTH) and cortisol levels in each blood sample were measured. Dominant-subordinate status was ascertained through two rank tests, the food competition test and the agonistic behavior test, which were performed immediately after pair formation. As a result, the dominance r…
Noninstrumented enzyme‐linked immunosorbant assay for detection of early pregnancy in macaques
A practical, noninstrumented enzyme‐linked immunosorbant assay (NELISA) for the measurement of urinary monkey chorionic gonadotropin (mCG) has been developed for the detection of early pregnancy in macaque monkeys for use in both the laboratory and the field. Five rhesus monkeys ( Macaca mulatta ) and six crab‐eating monkeys ( Macaca fascicularis ) were tested for the presence of mCG in urine on gestational days (GDs) 12 to 35. The mCG NELISA det…
Measurement of urinary and fecal steroid metabolites during the ovarian cycle in captive and wild Japanese macaques, Macaca fuscata
We measured the concentration of steroid hormones from urine, feces, and blood samples of two captive Japanese macaques, Macaca fuscata , during nonconceptive ovarian cycles to compare the patterns of the excreted steroids with those of circulating steroids. Urine and feces were analyzed for estrone conjugates (E 1 C) and pregnanediol‐3‐glucronide (PdG) using enzyme immunoassays (EIAs), while plasma was analyzed for estradiol‐17β(E 2 ), progester…
Hormonal Correlates of Maternal Style in Captive Macaques (Macaca fuscata and M. mulatta)
Fecal testosterone immunoreactivity as a non-invasive index of functional testosterone dynamics in male Japanese macaques (Macaca fuscata)
Comparative study of urinary reproductive hormones in great apes
Mother–infant relationships and maternal estrogen metabolites changes in macaques (Macaca fuscata, M. mulatta)
Inhibin B is the major form of inhibin secreted from testes in male Japanese macaques ( Macaca fuscata )
Levels of serum brain-derived neurotrophic factor in primates
Peripartum cortisol levels and mother‐infant interactions in Japanese macaques
As evidence accumulates regarding the influence of hormones and stress‐related conditions on maternal behavior, it becomes critical to better understand the relationship between physiological stress and the ability to cope with infants. Eight Japanese macaque females were observed 3 hr per week during the first 12 weeks after parturition; fecal samples were collected twice a week from each mother, starting 4 weeks before parturition and ending 4 …
Hormone profiles and reproductive characteristics in wild female Japanese macaques ( Macaca fuscata )
In this study we investigated the reproductive characteristics of wild female Japanese macaques ( Macaca fuscata fuscata ) in 2 nonconsecutive years using noninvasive methods to monitor physiological events. We detected ovulation dates and ascertained conceptions from fecal hormone profiles. First ovulations occurred from middle October to early November in 1997, and from middle to late November in 1999. Most females conceived during their first …
Seasonal variation in fecal testosterone levels in free‐ranging male Japanese macaques
Seasonal variation in fecal testosterone levels in free‐ranging male Japanese macaques ( Macaca fuscata ) was examined with reference to their dominance rank and age class. Six adult (≥7 years old, three higher‐ranking and three lower‐ranking) and four adolescent (5–6 years old, two higher‐ranking and two lower‐ranking) males were selected as target animals. Fecal samples of these males were collected during the first 3–5 days of each month and a…
Relationship between sexual interactions and the timing of the fertile phase in captive female Japanese macaques ( Macaca fuscata )
Japanese macaques live in multi‐male/multi‐female social groups in which competition between males, female mate choice, and alternative male mating strategies are important determinants of mating and reproductive success. However, the extent to which adult males rely on female behavior to make their mating decisions as well as the effect of social rank on mating success are not clear as results are inconclusive, varying from study to study. In th…
Seasonal and reproductive variation in body condition in captive female Japanese macaques ( Macaca fuscata )
The geographic distribution of Japanese macaques includes populations with the most northern range of any primate species. Not surprisingly, females of this species are characterized by physiological adaptations and unique fat deposition mechanisms that facilitate their survival through the sometimes‐harsh seasonal conditions of temperate climates, as well as sustaining the metabolic costs of mating, pregnancy, and lactation. Here, we explore the…
Birth in Free-ranging Macaca fuscata
Energetic consequences of seasonal breeding in female Japanese macaques ( Macaca fuscata )
Japanese macaques inhabit a relatively cold environment and females of this species could have developed strategies of energy economy to face the sometimes‐harsh seasonal conditions of temperate climates, as well as reproductive costs, and thus regulate their energy balance. Here, we explore the relationship between nutritional status, body composition, seasonality, and reproductive status using isotope‐labeled water, anthropometric measurements,…
Environmental, biological, and social factors influencing fecal adrenal steroid concentrations in female Japanese macaques ( Macaca fuscata )
The ability to determine hormonal profiles of primate populations using non-invasive techniques can help to monitor physical fitness, stress, and physiological responses to environmental changes. We investigated fecal glucocorticoids (fGC) and DHEAS concentrations in captive Japanese macaques (Macaca fuscata) in relation to environmental, biological, and social factors. The subjects were female Japanese monkeys from 4 months to 31 years old house…
Biology (28 works) · Primate Behavior and Ecology (19 works) · Zoology (18 works) · Medicine (16 works) · Endocrinology (14 works) · Animal Behavior and Reproduction (13 works) · Animal ecology (13 works) · Demography (11 works) · Neuroendocrine regulation and behavior (11 works) · Psychology (11 works)