Pubertal changes in testicular parameters and secretion of testosterone in Najdi and Naemi ram lambs under desert conditions

2017 ◽  
Author(s):  
Ahmed A. Al-kawmani ◽  
Mansour M. Alfuraiji ◽  
Saleh A. Kandeal ◽  
Mohammad Abul Farah ◽  
Khalid Mashai Alanazi
Keyword(s):  
Age Groups ◽  
Reproductive Capacity ◽  
Chronological Age ◽  
Testis Size ◽  
Age Group ◽  
Testosterone Concentration ◽  
Body Weights ◽  
Histological Appearance ◽  
Testicular Size ◽  
Ram Lambs

The present work was conducted to elucidate the relationships between chronological age, testosterone concentration and testis size of Najdi and Naemi ram lambs under desert conditions to determine the reproductive capacity of the above two breeds. The postnatal development of the seminiferous epithelium of the testes was also monitored. A total of 90 (45 Najdi and 45 Naemi lambs) aged between one and nine months, with five lambs at each month of age for each breed were used. The results showed that the testosterone concentration increased dramatically and rapidly between five and six months, followed by a period of gradual growth where testicular size was increased from 3 to 6 months of age. There was a significant (P > 0.05) difference in testosterone concentration (TC) and testis size (TS) in ram lambs between different age groups, similarly there were significant differences between body weights and lamb age between one and nine months. A positive correlation between the increasing body weight and the size of the testicle was observed. The testicles of lambs at each age-group had a different histological appearance except those of Najdi lambs at 2, 3 and 4 months and Naemi lambs at 2, 3, 4 and 5 months, where few differences were apparent. Small quantities were of spermatozoa appeared at the eighth month of age and increased in the ninth month. In conclusion, the current findings indicate that puberty in Najdi and Naemi rams occurs at the 8th and 9th month of age, respectively.

Dental Age Assessment of 8.5 to 17 Year-old Saudi Children Using Demirjian's Method

2008 ◽  
Vol 9 (3) ◽  
pp. 64-71 ◽  
Author(s):  
Suiaiman Al-Emran
Keyword(s):  
Age Groups ◽  
Chronological Age ◽  
Age Group ◽  
Dental Age ◽  
French Canadian ◽  
Age Assessment ◽  
Standard Values ◽  
Mandibular Teeth ◽  
Demirjian’S Method ◽  
Demirjian Method

Abstract Aim The aim of this study was to assess the dental age in Saudi children aged 8.5 to 17 years using the Demirjian method. Methods and Materials Four hundred ninety panoramic radiographs of boys and girls were reviewed retrospectively. All children were placed in the age group closest to their chronological age. The dental age was scored on all seven left mandibular teeth by one examiner. Results Both boys and girls in age groups nine to 14 years showed advanced dental age compared to their chronological age which was found to be statistically significant except in age groups nine and 13 years. Saudi boys were 0.3 years and Saudi girls 0.4 years ahead, on average, of French-Canadian children as analyzed by the Demirjian method. Conclusion The standard values for French-Canadian children provided by Demirjian vary slightly for application to Saudi children. As a result, new graphs and tables were produced to convert these maturity scores, calculated by the Demirjian method, to the dental age for Saudi children. Citation Al-Emran S. Dental Age Assessment of 8.5 to 17 Year-old Saudi Children Using Demirjian's Method. J Contemp Dent Pract 2008 March; (9)3:064-071.

scholarly journals PUBERAL DEVELOPMENT IN THE NIGERIAN DWARF SHEEP

2021 ◽  
Vol 7 (1) ◽  
pp. 71-76
Author(s):  
B. I. Orji ◽  
J. Steinbach
Keyword(s):  
Body Weight ◽  
Reproductive Tract ◽  
Age Groups ◽  
Reproductive Organs ◽  
The Body ◽  
Endocrine Function ◽  
Physiological Age ◽  
Body Weights ◽  
Pituitary Glands ◽  
Ram Lambs

Eleven ram lambs, all born between June and July (rainy season) were slaughtered at four age groups — 75, 100, 125 and 150 days. The body weights of animals prior to slaughter, the weights of the testes, the epididymis, the vesicular glands, the ampullae, the adrenals, the thyroids and the pituitary glands were determined and subjected to a step-wise multiple regression analysis using age or body weight as the independent variable. The weights of the reproductive organs – testes, epididymides, ampullae, vesicular glands - showed significantly higher correlation with the body weight than with the age, thus emphasizing the greater importance of the physiological age over the chronological age in the development of the body organs. The highest growth rate of the organs of the reproductive tract occurred during puberty and thus coincided with the enhanced endocrine function observed in ram lambs at this stage.

scholarly journals Relative Age-Related Biases in Objective and Subjective Assessments of Performance in Talented Youth Soccer Players

2021 ◽  
Vol 3 ◽  
Author(s):  
Daniel Leyhr ◽  
Fynn Bergmann ◽  
Robert Schreiner ◽  
David Mann ◽  
Damir Dugandzic ◽  
...  
Keyword(s):  
Age Groups ◽  
Technical Skills ◽  
Skewed Distribution ◽  
Soccer Players ◽  
Chronological Age ◽  
Age Group ◽  
Performance Levels ◽  
Relative Age ◽  
Psychosocial Skills ◽  
Future Performance

Talent research has recommended that multidimensional assessments of performance are needed to improve the identification and development of talented young athletes. However, factors such as the relative age effect may cloud our ability to assess factors related to performance. The aim of this study was to determine the extent of any relationship between soccer players' chronological and relative age, and objective and subjective performance assessments. Data for highly talented male soccer players selected into the German Soccer Associations' talent promotion program (N = 16,138) for U12 to U15 age groups (Mage = 12.62 ± 1.04 years) were examined. Besides anthropometric assessments, players completed a battery of five motor tests that objectively assessed speed abilities and technical skills (specifically sprint, agility, dribbling, ball control, and juggling). In addition, coaches subjectively rated players on their kicking, tactical, and psychosocial skills, as well as providing holistic evaluations of each player's current and future performance levels. Correlation analyses were used to investigate the extent of any relationships between the chronological and relative age of players and their results for each of the assessments. A strong linear decrease in the frequency of later-born players confirmed the overrepresentation of early-born players in all age groups (0.92 ≤ |r| ≤ 0.95, each p < 0.001). From U12 to U15, significant (each p < 0.001) correlations were found between the chronological age of players and their height (|r| = 0.70), weight (|r| = 0.69), speed abilities (|r| = 0.38), and technical skills (|r| = 0.43). When evaluating each age group separately, small effects were found when correlating relative age with the anthropometric assessments (0.18 ≤ |r| ≤ 0.26), and only trivial effects with speed abilities and technical skills (0.01 ≤ |r| ≤ 0.06). Similarly, low correlations were found for the subjective evaluations of kicking, tactical, and psychosocial skills with chronological age across age groups (0.03 ≤ |r| ≤ 0.07), and with relative age in each age group (0.01 ≤ |r| ≤ 0.11). The results show a skewed distribution toward early-born players and—in reference to their relative age—advanced performance in late-born athletes. However, trends toward a better holistic rating of early-born players for current and future performance levels were found. Coaches should be aware of these effects during talent selection, but also when interpreting results from subjective and objective assessments of performance.

scholarly journals DETERMINATION OF DENTAL AGE OF 10-13 YEAR-OLD CHILDREN OF THE CARPATHIAN REGION OF UKRAINE BY THE CAMERIERE METHOD IN COMPARISON WITH THEIR CHRONOLOGICAL AGE

2019 ◽  
pp. 63-70
Author(s):  
V.F. Makieyev ◽  
O.O. Isakova
Keyword(s):  
Age Groups ◽  
High Accuracy ◽  
Permanent Teeth ◽  
Chronological Age ◽  
Age Group ◽  
Dental Age ◽  
Ray Method ◽  
Significant Difference ◽  
Age Range

Purpose:  to evaluate the chronological and dental age of children in Lviv and the Lviv region aged 10-13 years with the help of the modified formula Cameriere.  Methods. Оrthopantomograms  46 children (26 boys and 20 girls) aged 10-13 years from Lviv and Lviv region have been used for this study. A questionnaire was developed for the submission of individual patient data and a standardized format for making their indicators derived from orthopantomograms (OPG). The examination of the area of the lower seven teeth on the left was done using the Cameriere method and the age of the child was evaluated, which was further compared with the chronological age.  Results.The obtained results of the study showed a high accuracy and reliability of the estimation of dental age in children up to 10-13 years with the help of the Cameriere formula modified by us. The research is based on the detection of physiological changes (the rate of formation of the roots) in the permanent teeth of children using the X-ray method.  Evaluating the results obtained by two methods, among girls and boys of the selected age group, a statistically significant strong correlation between the chronological age and the age calculated by the Cameriere method was revealed. Cameriere research has been carried out in many countries around the world and, in particular, in European countries, by implementing the general formula. Children in the period of occlusive bite remain the most critical in terms of age and, therefore, the determination of the correct time for dental interventions. In this age group, the development of permanent teeth passes through different stages and depends on many factors of the environment, genetic, geographical and food factors. The process of teething also affects many local factors, such as space and space for a permanent tooth in the dental artery and the loss of temporary precursors. Even with a large number of factors affecting the eruption and formation of permanent teeth in children, this method showed high accuracy and independence. In order to assess the Cameriere method among the children under study and its further practical application, a comparison was made between the age obtained using this methodology and the chronological age of the children under study in different age groups, both among boys and girls. Analyzing the obtained data, it was found that the mean of chronological age among the studied boys aged 10-11 (n = 14) was 11.02 ± 0.59 years, and the Cameriere method was 10.63 ± 1.03 years.  Student's assessment did not reveal a significant difference between the data (p = 0.22) for the age group of 10-11 years.  Further analysis among the studied boys revealed that in the age group 12-13 years the average chronological age was 12.94 ± 0.49 years, and the age was determined by the Cameriere method 12.59 ± 0.63 years, and no significant difference was established between them  (p = 0.14). The results of the studies have shown the suitability of the Cameriere formula modified during the process, based on the assessment of open tops and the number of teeth with completed root formation as a marker for the physiological development of the child and one that can be used to determine the child's age.Since studies had a limited age range on a particular sample of dental patients, further studies should evaluate the utility of this method in a larger sample of children in the extended age range of the given region of Ukraine and, if possible, adjust the formula we modified for the stability of the averaged indicators in different samples by age and sex. 

Size and Maturity Mismatch in Youth Soccer Players 11- to 14-Years-Old

2010 ◽  
Vol 22 (4) ◽  
pp. 596-612 ◽  
Author(s):  
António J. Figueiredo ◽  
Manuel J. Coelho e Silva ◽  
Sean P. Cumming ◽  
Robert M. Malina
Keyword(s):  
Skeletal Maturity ◽  
Age Groups ◽  
Goal Orientations ◽  
Pubic Hair ◽  
Soccer Players ◽  
Chronological Age ◽  
Age Group ◽  
Male Youth ◽  
Pubertal Status ◽  
Youth Soccer

The purpose of the study was to compare the anthropometric, functional and sport-specific skill characteristics and goal orientations of male youth soccer players at the extremes of height and skeletal maturity in two competitive age groups, 11–12 and 13–14 years. The shortest and tallest players, and least and most skeletally mature players (n = 8 per group) within each age group were compared on chronological age; skeletal age (Fels method); pubertal status (pubic hair); size, proportions and adiposity; four functional capacities; four soccer-specific skills; and task and ego orientation. The tallest players were older chronologically, advanced in maturity (skeletal, pubertal) and heavier, and had relatively longer legs than the shortest players in each age group. At 11–12 years, the most mature players were chronologically younger but advanced in pubertal status, taller and heavier with more adiposity. At 13–14 years, the most mature players were taller, heavier and advanced in pubertal status but did not differ in chronological age compared with the least mature players. Players at the extremes of height and skeletal maturity differed in speed and power (tallest > shortest; most mature > lest mature), but did not differ consistently in aerobic endurance and in soccer-specific skills. Results suggested that size and strength discrepancies among youth players were not a major advantage or disadvantage to performance. By inference, coaches and sport administrators may need to provide opportunities for or perhaps protect smaller, skilled players during the adolescent years.

scholarly journals Prediction of live body weights in dromedary camels (Camelus dromedarius) from morphometric body measurements

2020 ◽  
Vol 5 (1) ◽  
pp. 25
Author(s):  
Abdelaziz Ahmed Fadlelmoula ◽  
Abdelaziz Ahmed Fadlelmoula ◽  
Mohammed Saeed Mudarris ◽  
Mohammed Salih Hariri
Keyword(s):  
Age Groups ◽  
Dromedary Camel ◽  
Regression Equations ◽  
Body Measurements ◽  
Age Group ◽  
Third Age ◽  
Pooled Data ◽  
Live Body Weight ◽  
Body Weights ◽  
Positive Correlations

To predict the live body weight (LBW) of dromedary camel from morphometric body measurements (MBM) a regression equation was developed. A total of 223 camels (54 males and 169 females) from Makkah region of Saudi Arabia were classified into three age groups; first (<5 years old), second (5-8 years old) and third (>8 years old); two groups according to sex (male, female). LBW and 10 MBM were obtained. Data was subjected to statistical analysis. Results showed a significant (p<0.05) high mean LBW and MBM in males compared to females. A significant (p<0.05) positive correlations were encountered between LBW and HRG in all age groups, BG in third age group and males in second age group, HH and WH in first age group. The best fir regression equations were found to included HRG, BG and HG in the first and third age groups with R2 account for 90.59% and 93.82% respectively. Whereas in the second age group as well as pooled data the equation included HRG, BG, HH, HG and WH with R2 at level of 99.69% and 99.48% respectively. Multi-collinearity problem of MBM was not encountered as determined by VIF which was found to be less than 10. These formulas could be used for predicting LBW where weighing scales are not available.

Experience in applying the methodology for the study of psychological age in Ukraine: influence of psychological age on socio-political orientations

2020 ◽  
pp. 57-71
Author(s):  
Mykhailo Mishchenko
Keyword(s):  
Age Groups ◽  
Significant Proportion ◽  
Chronological Age ◽  
Age Group ◽  
The European Union ◽  
Demographic Group ◽  
Younger Age ◽  
Political Orientations ◽  
The Impact ◽  
The Relationship

The paper aims to study the relationship between psychological and chronological age, to identify factors affecting individual's perceptions of their psychological age, to disclose the impact of psychological age on socio-political orientations. The author used methodological approaches developed by Ye. Golovakha and A. Kronіk, who studied psychological age as “a measure of psychological past of personality” and, in particular, established the fact of predominance of psychological age’s undervaluation compared to chronological age. The results of the study carried out by the author in the 2017-2020, confirmed that the relationship between psychological and chronological age, detected in the beginning of the 1980s by Y. Golovakha and A. Kronіk, is resilient in times and under different macrosocial conditions. The author examines juvenile-associated socio-political orientations (orientations which more pronounced in younger age groups compared with older age groups, for example, support for Ukraine's membership in the European Union and NATO). The study shows that commitment to juvenile-associated socio-political orientations is related to change of age identity (when the individual most often seeks to self-identify with a younger age group than one he/she really belongs to). The study shows that youth in contemporary society is a reference age group, to which a significant proportion of members of society strive to be like (in imitation of social behavior and social values). This is due to the fact that in the contemporaneous culture the younger generation is associated with progressive social changes and to the fact that in modern society social success is associated in the mass conscious with youth. According to the study by Razumkov Centre, in all age groups percentage of those that assess their psychological age lower than chronological age increases together with the self-assessment of their welfare and with the level of their life satisfaction. The attitude of respondents to take their psychological age as lower than chronological age is related to the perception of youth as a reference socio-demographic group. Besides, the perception of youth as a reference socio-demographic group contributes to spreading the values and orientations of young people to middle and oldest age groups.

Trainable Children Can Learn Adjectives, Polars, and Prepositions!

1977 ◽  
Vol 8 (3) ◽  
pp. 181-187 ◽  
Author(s):  
Marlys Mitchell ◽  
Carolyn Evans ◽  
John Bernard
Keyword(s):  
Mentally Retarded ◽  
Chronological Age ◽  
Age Group ◽  
Achievement Gains ◽  
Active Involvement ◽  
Mentally Retarded Children ◽  
Locative Prepositions ◽  
Major Factors ◽  
Trainable Mentally Retarded

Twelve trainable mentally retarded children were given six weeks of instruction in the use of adjectives, polars, and locative prepositions. Specially prepared Language Master cards constituted the program. Posttests indicated that children in the older chronological age group earned significantly higher scores than those in the younger group. Children in the younger group made significant increases in scores, particularly in learning prepositions. A multisensory approach and active involvement in learning appeared to be major factors in achievement gains.

The Effect of Collagen Mediated Platelet Release on Plasma Prekallikrein Activation

1984 ◽  
Vol 51 (01) ◽  
pp. 037-041 ◽  
Author(s):  
K M Weerasinghe ◽  
M F Scully ◽  
V V Kakkar
Keyword(s):  
Platelet Aggregation ◽  
Healthy Volunteers ◽  
Platelet Rich Plasma ◽  
Age Groups ◽  
Inhibitory Effect ◽  
Age Group ◽  
Platelet Factor ◽  
Activated Platelets ◽  
Platelet Release ◽  
Collagen Treatment

SummaryCollagen mediated platelet aggregation caused -5.6 ± 6.7% inhibition and +39.1 ± 15.2% potentiation of prekallikrein activation in plasma from normal healthy volunteers between 20–40 and 50–65 years of age, respectively (n = 15, p <0.01). The amouns of platelet factor-four (PF4) released in the two groups were not significantly different. Collagen treatment in the presence of indomethacin caused +11.5 ± 3.6% and +59.6 ± 19.5% potentiation in the 20–40 and 50–65 age groups respectively (p <0.02). Adrenaline mediated platelet aggregation caused -55.2 ± 7.1% and -35.2 ± 8.3% inhibition in the 20–40 and 50–65 age groups, respectively. Collagen treatment of platelet-deficient-plasma and platelet-rich-plasma in EDTA also caused potentiation of prekallikrein activation.The results indicate that the observed degree of prekallikrein activation after platelet aggregation is a net result of the inhibitory effect of PF4 and the potentiatory effect of activated platelets. The potentiatory effect was greater after collagen treatment as compared to adrenaline treatment, and in the 50–65 age group as compared to the 20–40 age group.

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