• Title/Summary/Keyword: Sex Determination

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Sex and Sex Reversal of Bivalves (이매패류의 성과 성전환)

  • Lee, Jung Sick
    • The Korean Journal of Malacology
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    • v.31 no.4
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    • pp.315-322
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    • 2015
  • The sex of bivalves is classified into gonochorism and hermaphroditism, and hermaphroditism is further divided into simultaneous (synchronous or functional), and sequential (asynchronous). The sequential hermaphroditism signifies sex reversal in accordance with seasons. In general, in the case of gonochoristic bivalves, manifestation of sex as female and male, after having identified the morphological sex, is limited to a period of the life cycle in any given individual. In order to accurately identify sex, continuous monitoring of changes in the sex during life cycle is necessary by tagging the sex. In the bivalves, sex reversal and sequential hermaphroditism has been reported in the Ostreidae, Pectinidae, Veneridae and Arcidae etc.. Most of these studies have reached this conclusion based on evidence derived from sex ratio change in accordance with the age within same populations. Sex change in the sequential hermaphroditic bivalves normally occurs when the gonad is undifferentiated between spawning seasons. Two factors are involved in sex determination and sex change in bivalves, namely genetic and environmental. However, more detailed research is needed on the effect of the genetic and environmental factors involved in sex determination and sex change of bivalves.

Fetal Sex Determination by RIA of Amniotic Fluid Testosterone and FSH (태아성별(胎兒性別)에 따른 양수중(羊水中) Testosterone과 F.S.H.의 동태(動態)에 관(關)한 연구(硏究))

  • Koh, Min-Whan;Shin, Myon-Woo
    • Clinical and Experimental Reproductive Medicine
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    • v.6 no.1_2
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    • pp.23-28
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    • 1979
  • To determine whether hormone analysis of amniotic fluid could be used for accurate determination of fetal sex, we measured testosterone(T) and follicle-stimulating hormone in 19 amniotic fluid samples. The mean T in amniotic fluid of 8 women earring male fetuses was 310 pg. per milliliter and of 11 women earring female fetuses was 150 pg. per milliliter (P<0.05${\ast}$). The mean amniotic fluid FSH of 1.16 mI.U. per milliliter for 7 women with male fetuses was over trifold lower than that for subjects with female fetuses. The mean amniotic fluid FSH of female fetuses was 3.85 mI.U. per milliliter (P<0.01${\ast}$) Measurement of T & FSH in amniotic fluid may be an adjunct method for fetal sex determination.

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Effects of Sex Education Program related to the Unit of Reproduction and Development on Middle School Boys' Sex-related Knowledge and Attitude towards Sex (생식과 발생 단원과 연계한 성교육 프로그램이 중학교 남학생들의 성지식 및 성태도에 미치는 영향)

  • Kim, Sun Young;Park, Su Bin
    • Journal of Science Education
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    • v.42 no.2
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    • pp.148-164
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    • 2018
  • This study developed the sex education program based on the 'reproduction and development' unit of the middle school science, and examined its effectiveness on middle school boys' sex-related knowledge and attitude towards sex. The sex education program consisted of six topics of the structures and functions of generative organs, the importance of life, abortion, the human generation process, venereal diseases and AIDS, and responsibility of self-determination on sexual behavior. The results indicated that the experimental group demonstrated the statistically higher scores of the knowledge on sex than the control groups' scores, especially in the subcategories of 'pregnancy and delivery' and 'sex-related health'. However, both groups did not display any statistical difference on the attitude toward sex. In the subcategory of the attitude towards sex, the experimental group showed the statistically higher scores on 'self-determination and selection' and 'a health relationship'. In addition, the Pearson correlation results indicated the strongest relationship between the attitude toward sex and 'the self-determination and selection'. These results implicated that the sex education program related to the unit of reproduction and development in the middle school science helps the middle school boys develop the better knowledge and attitude towards sex.

십자매 암수 구별에 관한 연구

  • 장병귀;최철환;서옥석;나재천;강양수;하형돈
    • Proceedings of the Korea Society of Poultry Science Conference
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    • 2003.11a
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    • pp.131-132
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    • 2003
  • Common finch is a kind of ornamental birds and could not distinguish male and female birds. For sex discrimination of Common finch, we investigated 400 birds of Common finch using the anatomical differences of Pars intermandibularis and traditional methods that currently used at the farms. Both methods have the sex determination accuracy of 48.82 and 46.0 % that the anatomical difference method seems little higher results than the traditional methods. More researches is needed for improving the sex determination accuracy.

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Comparison of data mining algorithms for sex determination based on mastoid process measurements using cone-beam computed tomography

  • Farhadian, Maryam;Salemi, Fatemeh;Shokri, Abbas;Safi, Yaser;Rahimpanah, Shahin
    • Imaging Science in Dentistry
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    • v.50 no.4
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    • pp.323-330
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    • 2020
  • Purpose: The mastoid region is ideal for studying sexual dimorphism due to its anatomical position at the base of the skull. This study aimed to determine sex in the Iranian population based on measurements of the mastoid process using different data mining algorithms. Materials and Methods: This retrospective study was conducted on 190 3-dimensional cone-beam computed tomographic (CBCT) images of 105 women and 85 men between the ages of 18 and 70 years. On each CBCT scan, the following 9 landmarks were measured: the distance between the porion and the mastoidale; the mastoid length, height, and width; the distance between the mastoidale and the mastoid incision; the intermastoid distance (IMD); the distance between the lowest point of the mastoid triangle and the most prominent convex surface of the mastoid (MF); the distance between the most prominent convex mastoid point (IMSLD); and the intersecting angle drawn from the most prominent right and left mastoid point (MMCA). Several predictive models were constructed and their accuracy was compared using cross-validation. Results: The results of the t-test revealed a statistically significant difference between the sexes in all variables except MF and MMCA. The random forest model, with an accuracy of 97.0%, had the best performance in predicting sex. The IMSLD and IMD made the largest contributions to predicting sex, while the MMCA variable had the least significant role. Conclusion: These results show the possibility of developing an accurate tool using data mining algorithms for sex determination in the forensic framework.

Sex Ratios of Juveniles Hatched by Constant Temperatures Artificial Incubation From Eggs Collected in the Natural Nest of Soft-Shelled Turtle, Trionyx sinensis Strauch (1862) (한국산 자라, Trionyx sinensis (1862)의 자연산란둥지에서 수거한 난들의 항온인공부화에 의해 출생한 새끼자라들의 성비)

  • KIM, Sung Han
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.3
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    • pp.702-710
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    • 2017
  • Recently, in many reptiles (14 genera of turtles in five families), common characteristics of incubation temperatures are known to determine the sexes of hatchlings in many species of turtles, including the map turtles, painted turtles and snapping turtles, emys turtle, etc. According to many researcher's reports, in general, incubation at $25^{\circ}C$ (cooler temperatures) produces all or mostly males, however, incubation at $31^{\circ}C$ (higher temperatures) or higher produces all or mostly females. Exceptionally, even cooler temperature ($20^{\circ}C$) produce females, they produced all or mostly females. Accordingly, it is well-known that incubation temperature is the sex determining agent in these turtles. However, this paper presents study of the sex ratio and nest ecology in natural spawning nest: Observations on hatching sex ratios of eggs collected from natural nests of T. sinensis are similar to a previous report of the same genus Trionyx in the soft-shelled turtles. However, this genus (or species) showed some different phenomena to other kinds of turtles such as various kinds turtles mentioned above. After collection of naturally spawned eggs (17 eggs of T. sisnensis) on the natural nests, a laboratory experiment by the constant incubation temperatures was conducted with natural fluctuating soil temperatures in the natural nest with the soft-shelled turtle, T. sinensis. And also laboratory experiments were conducted using constant incubation temperatures of $25^{\circ}C$ (cooler temp.) and $30^{\circ}C$ (higher temp.) with the turtle, T. sinensis. Exceptionally, it was confirmed that the first and second incubation temperatures can't control sex-determination in the freshwater soft-shelled turtle, T. sinensis. The sex ratio approximated 1:1 (${\chi}^2=0.06$, P>0.05 (the Ist experiment). And the sex ratio approximated 1:1 independently of incubation temperature (${\chi}^2=0.33$, P>0.05 (the 2nd experiment). Consequently, temperature has no effect on sex determination in the genus Trionyx in a soft-shelled turtle.

Sex Ratio Determination by Quantitative Real Time PCR using Amelogenin Gene in Porcine Sperm

  • Hwang, You-Jin;Bae, Mun-Sook;Yang, Jae-Hun;Kim, Bo-Kyoung;Kim, Sang-Ok;Lee, Eun-Soo;Choi, Sun-Gyu;Kwon, Ye-Ri;Seo, Min-Hae;Park, Choon-Keun;Kim, Dae-Young
    • Journal of Embryo Transfer
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    • v.24 no.3
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    • pp.225-230
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    • 2009
  • Sex-sorting of sperm is an assisted reproductive technology (ART) used by the livestock industry for the mass production of animals of a desired sex. The standard method for sorting sperm is the detection of DNA content differences between X and Y chromosome-bearing sperm by flow cytometry. However, this method has variable efficiency and therefore requires verification by a second method. We have developed a sex determination method based on quantitative real-time polymerase chain reaction (qPCR) of the porcine amelogenin (AMEL) gene. The AMEL gene is present on both the X and the Y chromosome, but the length and sequence of its noncoding regions differ between the X and Y chromosomes. By measuring the threshold cycle (Ct) of qPCR, we were able to calculate the relative frequency of X chromosome. Two sets of AMEL primers were used in these studies. One set (AME) targeted AMEL gene sequences present in both X and Y chromosome, but produced PCR products of different lengths for each chromosome. The other set (AXR) bound to AMEL gene sequences present on the X chromosome but absent esholthe Y-chromosome. Relative product levels were calculated by normalizing the AXR fluorescence to the AME fluorescence. The AMEL method accurately predicted the sex ratios of boar sperm, demonstrating that it has potential value as a sex determination method.

Sex determination by radiographic localization of the inferior alveolar canal using cone-beam computed tomography in an Egyptian population

  • Mousa, Arwa;El Dessouky, Sahar;El Beshlawy, Dina
    • Imaging Science in Dentistry
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    • v.50 no.2
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    • pp.117-124
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    • 2020
  • Purpose: The purpose of this study was to evaluate possible differences in the location of the inferior alveolar canal in male and female Egyptians. Materials and Methods: This cross-sectional retrospective study involved the evaluation of 210 CBCT scans of Egyptian individuals (18-70 years old). The inferior alveolar canal was localized by measuring 8 linear dimensions: 2 for the vertical localization of the mental foramen (superior and inferior to the mental foramen), 4 at the first molar bifurcation for the vertical and horizontal localization of the inferior alveolar canal (superior, inferior, buccal, and lingual to the inferior alveolar canal), and 2 for the horizontal localization of the mandibular foramen (anterior and posterior to the mandibular foramen). The measurements were statistically analyzed via comparative analysis, stepwise logistic regression, and receiver operating characteristic (ROC) curve analysis. Results: Six of the 8 measured distances differed to a statistically significant extent between the sexes. Regression analysis suggested a logistic function with a concordance index of 84%. The diagnostic accuracy capabilities of the linear measurements as sex predictors were calculated using ROC analysis, and the 6 best predictors for sex determination were selected and ranked from highest to lowest predictive power. Moreover, combining these 6 predictors increased the predictive power to 84%. Conclusion: The location of the inferior alveolar canal in the Egyptian population varies significantly by sex; accordingly, this anatomic landmark could be used as a reliable indicator of sexual dimorphism.

Sex and Age Determination of the Kaya s Ancient Human Skeletal Remains via Dental Approaches (가야시대 인골의 치아에 의한 성별 및 연령추정)

  • Mee-Eun Kim;Myung-Yun Ko;Bong-Soo Park
    • Journal of Oral Medicine and Pain
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    • v.21 no.2
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    • pp.225-242
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    • 1996
  • The author studied to determine the sex and age of 8 ancient human skeletal remains, which had excavated from ancient tombs located in Yeanri, Kimhae. Some kinds of personal identification methods their skulls and teeth were used for this study and the results were obtained as follows : 1. Sex determination was possible in ancient teeth from 4th to 5th century, using detection of X-Y homologous amelogenin gene by polymerase chain reaction. 2. DNA analysis proved that the materials examined were all male, but which always did not coincide with the results from other methods for sex determination including comparison of sexual differentiation of cranium and teeth and use of discriminant functions in the dental measurement. 3. There was little difference of the estimated ages between the methods by regression of pulp cavity and attrition in teeth. The ages from these two methods always did not coincide with ones from evaluation closure of cranial and palatal sutures. 4. Sex and age of the materials were determined as follows ; $\cdot$ Y9 was estimated to be male in early sixties. $\cdot$ Yl2 was estimated to be male in late twenties to early thirties. $\cdot$ Y37 was estimated to be male in early forties. $\cdot$ Y70 was estimated to be male in early sixties. $\cdot$ Y87 was estimated to be male in late forties. $\cdot$ Y109 was estimated to be male in early forties. $\cdot$ Yl29 was estimated to be male in late thirties to early forties. $\cdot$ Yl42 was estimated to be male in late fifties to early sixties.

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