• Korean Journal of Child Studies
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• v.11 no.2
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• pp.82-97
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• 1990

The purpose of this study was to investigate (1) the developmental level of children's concept of gender by age and sex. (2) children's sex-specific behaviors by age and sex, and (3) children's sex-specific behaviors by developmental level of gender constancy. The subjects were 164 children (forty 3-year-olds, forty-three 5-year-olds, forty 7-year-olds and forty-one 9-year olds) with nearly equal numbers of boys and girls. They were selected from two kindergartens and one elementary school. A quasi experiment was carried out with the procedures described by Slaby and Frey (1976) to measure children's developmental level of the concept of gender constancy. Two experiments were carried out to observe children's sex-specific behaviors: one for children's toy choice behavior and the other for children's interaction with their peers. Statistical methods adopted for data analysis were frequencies. percentiles, mean. and $X^2$. It was found that children's sex-specific behaviors were different according to their developmental level of gender constancy. Children's developmental level of gender constancy was significantly different according to their age, but there was no difference according to their sex. Children's toy-choice behavior was significantly different according to their age and sex. Children's sex-specific behaviors were significantly different according to their concept of gender constancy.

• Fisheries and Aquatic Sciences
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• v.22 no.8
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• pp.18.1-18.5
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• 2019

The development of sex-specific genetic assays in a species provides both a method for identifying the system of sex determination and a valuable tool to address questions of conservation and management importance. In this study, we focused on the identification of single nucleotide polymorphisms (SNPs) that differentiate genetic sex in burbot Lota lota. Burbot are the only true freshwater representative of the cod family and a species of conservation and management importance throughout Eurasia and North America. To identify sex-specific SNPs, we utilized restriction site-associated DNA sequencing (RADseq) to interrogate thousands of SNPs in burbot samples of known phenotypic sex. We discovered 170,569 biallelic SNPs, none of which fit the pattern expected under female heterogamety. However, we identified 22 SNPs that fit the pattern expected under male heterogamety (males heterozygous XY, females fixed XX) and, from these, developed two genetic assays that robustly (~ 97% genotyping success) and accurately (> 99% correct) sexed burbot samples. These sex-specific genetic assays will benefit growing conservation aquaculture programs for this species and allow future assessments of sex-specific migration, growth, and mortality.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.4 no.4
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• pp.154-158
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• 2023

The Asiatic black bear, Ursus thibetanus, is among the most threatened or endangered species in Asia. For its conservation and management, sex identification of U. thibetanus using non-invasive samples (e.g., hair and/or feces) is potentially valuable. In this study, a non-invasive molecular method for sex identification of U. thibetanus samples collected from various countries was first utilized, and it was based on polymerase chain reaction (PCR) amplification of the amelogenin gene via PCRs. Thirty-three bear DNA samples, extracted not only from blood (n=9) but also from hair (n=18) and feces (n=6), were used. We performed sex-specific PCR amplifications of the amelogenin gene using a primer set, SE47 and SE48. The primer set could successfully amplify a single X-specific band for females and both X- and Y-specific bands for males from all blood (100%) and hair (100%) samples. In addition, the primer set could distinguish the sex of bears in four out of a total of six fecal samples (approximately 67%). This study's findings suggest that this molecular method can be applied to sex identification of Asiatic black bears from various Asian regions using non-invasive samples, such as hair and feces.

• Research in Community and Public Health Nursing
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• v.6 no.2
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• pp.197-211
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• 1995

This study was designed to identify school health nurses' attitudes toward sex education through a Q-methodological approach. Research was done from Apr. 3, 1995 to Oct. 15, 1995. A final Q-sample was selected to 37 statements out of initial 128 statements after consultation from counselors, educators and writers related to sex education. The P -sample was consisted with 32 school health nurses in Chonbuk province. The collected data were analyzed by Quanal program on PC. The results of the study were as follows: School health nurses are categorized into 6 types. The first type, receiving type with cognition deficiency about general learning objectives of sex education were consisted with 4 subjects. The second type, valuing type with cognition deficiency about general learning objectives of sex education were consisted with 6 subjects. The third type, adopting behavior type with cognition deficiency about specific learning objectives of sex education were consisted with 5 subjects. The fourth type, receiving type with cognition deficiency about specific learning objectives of sex education were consisted with 5 subjects. The fifth type, making sense of information type with cognition deficiency about specific learning objectives of sex education were consisted with 5 subjects. The sixth type, adopting behavior type with cognition deficiency about general learning objectives of sex education were consisted with 7 subjects. As a result of this study, we may realize necessity of prepared sex educators. Sex the educators must be fully cognitive and affective toward sex education before practicing sex education.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3469-3476
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• 2016

Background: The cancer research literature suggests that women, especially premenopausal women, have lower cancer mortality rates than men. However, it is unclear if that is true for populations at all age levels in all countries and what factors affect such sex differences. This paper attempts to fill that gap. Materials and Methods: Sex- and country-specific cancer mortality data were statistically analyzed with particular attention to geographic, social, and economic factors that may affect the sex differences. Results: The sex differences were age and country specific, rather than universal. Premenopausal women actually tend to have a disadvantage compared to men or postmenopausal women. Male cancer mortality appears to be the affecting factor in explaining variations in sex differences. Latitude of residence and literacy rate are the affecting factors in cancer mortality and sex differences. African and Latin American countries tend to have a female disadvantage, while East Asian and Eastern European countries are more likely to have a female advantage. Conclusions: The findings challenge the cancer mortality literature and indicate that the sex differences and their possible causes are more complicated than the current literature suggests. They also highlight the urgency of adapting age- and country- specific health systems and policies to better meet the needs of younger women.

• Korean Journal of Animal Reproduction
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• v.20 no.2
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• pp.89-99
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• 1996

The purpose of this study was to develop the diagnosis techniques for sex determination of rabbit embryos at preimplantation stage. To detect male specific sequences using polymerase chain reaction, two genes functional on sex determination including SRY and ZFX/Y genes were targeted using multiple oligonucleotide primer sets. Three of them for conserved SRY gene were used for appropriate amplification pattern, and then only one primer set #3 proved to be most efficient, showing male-specific strong signal ofamplified sequences. Using this male specific bandsfrom human, cattle, pig and mouse, the gender of rabbit was determined. As an another system for sex determination system, amplified 910bp fragment from ZFX/Y was digested with several restriction endonuclease and showed gender specific restriction fragments only by Hinf I. Using two different system for sex identification of rabbit in this study, blind tests for 17 samples was conducted and showed identical results from two different methods. And then, amplification limit of PCR reaction for template DNA was estimated using various amounts of DNA for both SRY and ZFX/Y systems, resulted as 20pg and 800pg, respectively. With this results, test for gender identification of rabbit embryos were performed using SRY derived amplification system. From total 22 embryos selected for its developmental state 18 were identified as male embryos, showing significant difference from expected sex ratio 1:1. This biased sex ratio was interpreted as to have been caused by the fact, reported by the fact, reported by several researchers, that male embryos develop more rapidly and are more resistant against the in vitro manipulation than female embryos.

• Safety and Health at Work
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• v.5 no.3
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• pp.113-117
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• 2014

The mechanisms by which iron is absorbed are similar to those of divalent metals, particularly manganese, lead, and cadmium. These metals, however, show different toxicokinetics in relation to menarche or menopause, although their interaction with iron is the same. This review focuses on the kinetics of these three toxic metals (manganese, lead, and cadmium) in relation to menarche, pregnancy, and menopause. The iron-manganese interaction is the major factor determining sex-specific differences in blood manganese levels throughout the whole life cycle. The effects of estrogen overshadow the association between iron deficiency and increased blood lead concentrations, explaining why women, despite having lower ferritin concentrations, have lower blood lead concentrations than men. Iron deficiency is associated with elevated cadmium levels in premenopausal women, but not in postmenopausal women or men; these findings indicate that sex-specific differences in cadmium levels at older ages are not due to iron-cadmium interactions, and that further studies are required to identify the source of these differences. In summary, the potential causes of sex-specific differences in the blood levels of manganese, lead, and cadmium differ from each other, although all these three metals are associated with iron deficiency. Therefore, other factors such as estrogen effects, or absorption rate as well as iron deficiency, should be considered when addressing environmental exposure to toxic metals and sex-specific differences in the blood levels of these metals.

• Physical Therapy Korea
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• v.30 no.4
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• pp.275-280
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• 2023

Background: Although warm-ups before exercise are widely accepted, research on sex differences in improving hamstring flexibility is limited. Differences in the physical and physiological characteristics between males and females may result in different responses to warm-ups. Objects: This study aimed to examine sex differences in the effects of specific warm-up on hamstring flexibility. Methods: This study included 24 young adults with hamstring tightness. The participants performed five maximal knee extensions and flexions at 90° flexion of the hip, and the maximal knee extension angle was measured in real-time using a smartphone clinometer application. Results: The groups did not significantly affect the maximal knee extension angle but showed a significant effect for repetition (p = 0.002) and group-repetition interaction (p = 0.002). Males had no significant change in hamstring flexibility; however, females showed a significant increase in flexibility in the 5^th trial compared with the 1^st trial (p = 0.041). These results demonstrated sex-specific differences in flexibility improvement over time. Conclusion: The findings of this study suggest that specific warm-up can successfully improve hamstring flexibility in females. This may be due to various factors, such as muscle stiffness of the lower extremity, estrogen levels, and temperature sensitivity. In clinical settings, specific warm-up might be helpful for females who participate in sports or activities, such as running or jumping, which require a full range of motion in the hip and knee joints.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.15-47
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• 2021

Sex pheromone is used for chemical communication for mating in a species-specific manner in insects. Insect antennae possess sensory receptors specific to sex pheromone components and generate receptor potential to be perceived by the brain to evoke mating behavior. The sex pheromones have been used for monitoring specific species of insect pests to predict their subsequent occurrences based on a temperature-dependent growth model. Sex pheromones are also used for controlling pest insects using several different strategies such as mass capture, lure-and-kill, or mating disruption. This review explains the sensory physiology and insect pest management techniques related with sex pheromone.

• Journal of Photoscience
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• v.12 no.2
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• pp.75-82
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• 2005

Rumex acetosa L. is a dioecious flowering plant with well developed sex chromosome system: 2n = 12 + XX in the female plants and 2n = 12 + XY1Y2 in the male plants. To isolate sex-linked DNA, we carried out chromosome micromanipulation, followed by DOP-PCR, AFLP of the PCR products, reverse Southern hybridization and sequence analysis. From 500 AFLP specific clones, 13 X-chromosome and 5 Y-chromosome specific clones were obtained. Except one clone RADAX-239 ($\underline{R}umex\;\underline{a}-\underline{D}OP-PCR-\underline{A}FLP-\underline{Y}-chromosome\;specific$), all clones appear to be R. acetosa plant-specific sequences and non-coding sequences. Southern blot analysis using these clones could not discriminate genomic DNAs either from male or female plants. Results of this study imply that both autosome-origin and degeneration of sex chromosomes are prevalent in plant systems.