Sexual Maturation, Reproductive Habits, and Fecundity of Fish

2022 ◽  
pp. 113-142
Author(s):  
Xinjun Chen ◽  
Bilin Liu ◽  
Dongming Lin
Keyword(s):  
MedPharmRes ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 33-37
Author(s):  
Tam M. Do ◽  
Thanh K. Van ◽  
Huyen TT. Bich ◽  
Thanh TK. Tran ◽  
Minh X. Ngo ◽  
...  

Background: Puberty is a milestone in child and adolescent development, yet a feasible tool to accurately assess pubertal stage in community context has not been validated in Vietnam. Aim: This study was conducted to validate pubertal self-report among Ho Chi Minh City children and adolescents in comparison with paediatrician’s assessment. Methods: 80 girls and 76 boys aged from 6 to 17 years old from 5 schools in Ho Chi Minh City were recruited. Self-administered questionnaires about sexual maturation were distributed to participants and results were compared with physician’s pubertal examination. Kappa statistic and Kendall’s τ b were used to evaluate validity of the questionnaire. Results: Boys tended to overestimate their development stages while girls tended to underestimate. Fair to almost perfect agreement between students’ reports and paediatricians’ evaluation, along with high concordance was recorded, however younger boys (aged 6-11) showed limited evaluation of their own sexual maturation. Conclusion: This method was inaccurate to evaluate younger boys’ sexual maturation; however, acceptable accuracy in sexual maturation estimation among younger girls and adolescents could allow it to serve as an effective screening tool in community context.


2009 ◽  
Vol 0 (0) ◽  
Author(s):  
Jenner C. V. Azevedo ◽  
Lana M. P. Brasil ◽  
Taísa B. M. A. Macedo ◽  
Lúcia F. C. Pedrosa ◽  
Ricardo F. Arrais

Author(s):  
Elizabeth K. Reynolds ◽  
Linda C. Mayes

Adolescence is the time between the beginning of sexual maturation and adulthood, typically bounded by the ages of 13 to 19 years. One construct that holds a central place in many theories of development and psychopathology is impulsivity. Impulsivity has been considered to play an important role in normal behavior as well as linked to several problematic behaviors that are present or arise during adolescence. Impulsivity, considered to be a multidimensional construct, has been defined and measured in a variety of ways. This chapter will discuss the definitions of impulsivity, measurement (including self-report and behavioral tasks), developmental course, behaviors and disorders in which it is implicated, and future directions.


Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 419
Author(s):  
Valeria Calcaterra ◽  
Hellas Cena ◽  
Corrado Regalbuto ◽  
Federica Vinci ◽  
Debora Porri ◽  
...  

Puberty is a crucial developmental stage in the life span, necessary to achieve reproductive and somatic maturity. Timing of puberty is modulated by and responds to central neurotransmitters, hormones, and environmental factors leading to hypothalamic-pituitary-gonadal axis maturation. The connection between hormones and nutrition during critical periods of growth, like fetal life or infancy, is fundamental for metabolic adaptation response and pubertal development control and prediction. Since birth weight is an important indicator of growth estimation during fetal life, restricted prenatal growth, such as intrauterine growth restriction (IUGR) and small for gestational age (SGA), may impact endocrine system, affecting pubertal development. Successively, lactation along with early life optimal nutrition during infancy and childhood may be important in order to set up timing of sexual maturation and provide successful reproduction at a later time. Sexual maturation and healthy growth are also influenced by nutrition requirements and diet composition. Early nutritional surveillance and monitoring of pubertal development is recommended in all children, particularly in those at risk, such as the ones born SGA and/or IUGR, as well as in the case of sudden weight gain during infancy. Adequate macro and micronutrient intake is essential for healthy growth and sexual maturity.


2020 ◽  
pp. 1-26
Author(s):  
Jéssica Cumpian Silva ◽  
Ana Elisa Madalena Rinaldi ◽  
Francisco de Assis Guedes Vasconcelos ◽  
Maria Alice Altenburg Assis ◽  
Camila Medeiros Mazzeti ◽  
...  

ABSTRACT Objective: Our study aimed to describe body phenotypes (BP) estimated by multivariate analysis and their association with body mass. Design: Body phenotypes were defined based on demographic variables, anthropometric data (body mass, height, skinfolds and circumferences), body composition (phase angle measured by bioelectrical impedance analysis), biochemical parameters (triglycerides, glucose, total cholesterol ratio/Low Density Lipoproteins (LDL), haemoglobin and sexual maturation (pubic hair and breasts or gonads). Analysis of variance (ANOVA) was performed to verify the differences between skin colour and the stages of pubertal development, body phenotypes, body composition, anthropometric, and biochemical variables. Setting: Cities of São Paulo-SP, Piracicaba-SP and Florianópolis-SC from Brazil and the United States. Participants: 9269 adolescents aged between 10 to 15 years old. Results: The composition of BP was similar in all surveys, which are: BP1 was composed by skinfolds, body mass and circumferences variables; BP2 by pubic hair, breast in girls or gonad in boys, height and age; BP3 by cholesterol, triglycerides and glucose; and BP4 by phase angle, haemoglobin and glucose (negative loading). There was a strong correlation (r = 0.9, p <0.001) between BP1 and body mass index. Conclusion: We highlighted independence observed between biochemical parameters, anthropometry, body composition and sexual maturation. BP may support the calculation of scores for diagnosis of obesity based on anthropometric variables and overcome ambiguity in the isolated use of body mass index.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toshihiro Horiguchi ◽  
Kayoko Kawamura ◽  
Yasuhiko Ohta

AbstractIn 2012, after the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) that followed the Tohoku earthquake and tsunami in March 2011, no rock shell (Thais clavigera; currently recognized as Reishia clavigera; Gastropoda, Neogastropoda, Muricidae) specimens were found near the plant from Hirono to Futaba Beach (a distance of approximately 30 km). In July 2016, however, rock shells were again found to inhabit the area. From April 2017 to May 2019, we collected rock shell specimens monthly at two sites near the FDNPP (Okuma and Tomioka) and at a reference site ~ 120 km south of the FDNPP (Hiraiso). We examined the gonads of the specimens histologically to evaluate their reproductive cycle and sexual maturation. The gonads of the rock shells collected at Okuma, ~ 1 km south of the FDNPP, exhibited consecutive sexual maturation during the 2 years from April 2017 to May 2019, whereas sexual maturation of the gonads of specimens collected at Hiraiso was observed only in summer. The consecutive sexual maturation of the gonads of the specimens collected at Okuma might not represent a temporary phenomenon but rather a site-specific phenotype, possibly caused by specific environmental factors near the FDNPP.


Author(s):  
Susmita Ghosh ◽  
Md Ruhul Kabir ◽  
Mohammad Rahanur Alam ◽  
Akibul Islam Chowdhury ◽  
Md Abdullah Al Mamun

AbstractObjectivesAdolescence, a crucial period for growth velocity including sexual maturation, is an important period of life and young adolescent girls need to have proper knowledge, positive attitudes and practice of balanced diet to achieve optimum growth and development. Considering its importance this study attempts to assess the knowledge, attitude and practice (KAP) of balanced diets among adolescent schoolgirls in Noakhali district, Bangladesh.MethodsA descriptive cross-sectional study was conducted in three secondary schools in Noakhali district, Bangladesh. A multistage sampling techniques was used to select schools and study participants. A total of 485 adolescent school girls participated and a pre-designed, validated and structured questionnaire was used for data collection. In addition to descriptive statistics, chi-square test and logistic regression were employed for analysis.ResultsThe results from the study revealed that more than half of the students did not have good knowledge about a balanced diet, 42.8% had a positive attitude, whereas the practice of consuming a balanced diet was rather low (only 4.5%). Students studying in government schools had better knowledge and attitudes than non-government school students. Moreover, 41.1% of students were underweight; more than 60% of respondent’s mothers did not have an education higher than secondary school and were mostly unemployed housewives. Parent’s education, mother’s occupation, and types of school have a strong association with KAP; however, father’s education and occupation showed an association of varying degrees. Being knowledgeable was related to positive attitudes, and students with good knowledge had (OR: 1.828; 95% CI: 1.270–2.631) more likely to have positive attitudes towards a balanced diet.ConclusionsThus, proper knowledge about a balanced diet should be introduced with basic nutritional knowledge to all levels of public education. Interventions and programs can be designed to improve knowledge, attitude, and more specifically the practice at the household level so that adolescent girls can have a proper diet during their sexual maturation phase.


2016 ◽  
Vol 109 (2) ◽  
pp. 637-643 ◽  
Author(s):  
Rodolfo Muñoz-Barrios ◽  
Leopoldo Cruz-López ◽  
Julio C. Rojas ◽  
Emilio Hernández ◽  
Pablo Liedo ◽  
...  

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