Testosterone Trajectories and Reference Ranges in a Large Longitudinal Sample of Male Adolescents

Pubertal dynamics plays an important role in physical and psychological development of children and adolescents. We aim to provide reference ranges of plasma testosterone in a large longitudinal sample. Furthermore, we describe a measure of testosterone trajectories during adolescence that can be used in future investigations of development.We carried out longitudinal measurements of plasma testosterone in 2,216 samples obtained from 513 males (9 to 17 years of age) from the Avon Longitudinal Study of Parents and Children. We used integration of a model fitted to each participant's testosterone trajectory to calculate a measure of average exposure to testosterone over adolescence. We pooled these data with corresponding values reported in the literature to provide a reference range of testosterone levels in males between the ages of 6 and 19 years.The average values of total testosterone in the ALSPAC sample range from 0.82 nmol/L (Standard Deviation [SD]: 0.09) at 9 years of age to 16.5 (SD: 2.65) nmol/L at 17 years of age; these values are congruent with other reports in the literature. The average exposure to testosterone is associated with different features of testosterone trajectories such as Peak Testosterone Change, Age at Peak Testosterone Change, and Testosterone at 17 years of age as well as the timing of the growth spurt during puberty.The average exposure to testosterone is a useful measure for future investigations using testosterone trajectories to examine pubertal dynamics

Assessing Pubertal Timing and Dynamics in a Large Longitudinal Sample of Adolescent Males

Pubertal timing and dynamics play an important role in physical and psychological development. This thesis describes three height-based indices that can be used to assess pubertal timing, and a measure of average exposure to testosterone derived from testosterone trajectories to assess pubertal dynamics. These parameters are derived in a sample of 500 male adolescents from the Avon Longitudinal Study of Parents and Children (ALSPAC). The indices of pubertal timing are shown to correlate with one another in ALSPAC. In a separate cross-sectional study, we show the association between one index and both testosterone levels and self-reported pubertal stage. The measure of average exposure to testosterone characterizes the timing and the magnitude of the rise in participants’ testosterone levels during adolescence. Future investigations may employ the methods outlined to account for timing and dynamics of puberty in relation to adolescent development.MAS

Designing 1D Chaotic Maps for Fast Chaotic Image Encryption

Chaotic maps that can provide highly secure key sequences and ease of structure implementation are predominant requirements in image encryption systems. One Dimensional (1D) chaotic maps have the advantage of a simple structure and can be easily implemented by software and hardware. However, key sequences produced by 1D chaotic maps are not adequately secure. Therefore, to improve the 1D chaotic maps sequence security, we propose two chaotic maps: 1D Improved Logistic Map (1D-ILM) and 1D Improved Quadratic Map (1D-IQM). The proposed maps have shown higher efficiency than existing maps in terms of Lyapunov exponent, complexity, wider chaotic range, and higher sensitivity. Additionally, we present an efficient and fast encryption method based on 1D-ILM and 1D-IQM to enhance image encryption system performance. This paper also introduces a key expansion method to reduce the number of chaotic map iteration needs, thereby decreasing encryption time. The security analyses and experimental results are confirmed that 2D Correlation Coefficient (CC) Information Entropy (IE), Number of Pixels Change Rate (NPCR), Unified Average Changing Intensity (UACI), Mean Absolute Error (MAE), and decryption quality are able to meet the encryption security demands (CC = −0.00139, IE = 7.9990, NPCR = 99.6114%, UACI = 33.46952% and MAE = 85.3473). Furthermore, the proposed keyspace reaches 10240, and the encryption time is 0.025s for an image with a size of 256 × 256. The proposed system can yield efficacious security results compared to obtained results from other encryption systems

Height-based Indices of pubertal Timing in Male Adolescents

It is important to account for timing of puberty when studying the adolescent brain and cognition. The use of classical methods for assessing pubertal status may not be feasible in some studies, especially in male adolescents. Using data from a sample of 478 males from a longitudinal birth cohort, we describe the calculations of three independent height-based markers of pubertal timing: Age at Peak Height Velocity (APHV), Height Difference in Standard Deviations (HDSDS), and Percent Achieved of Adult Stature (PAAS). These markers correlate well with each other. In a separate cross-sectional study, we show that the PAAS marker correlates well with testosterone levels and self-reported pubertal-stage scores. We conclude by discussing key considerations for investigators when drawing upon these methods of assessing pubertal timing

Testosterone trajectories by quintiles of the growth-spurt timing.

<p>Earlier (Quintile 1) versus late (Quintile 5) growth spurt is associated with (A) earlier rising testosterone trajectories, and (B) earlier onset of peak change in testosterone. Trajectories are plotted with adjusted testosterone values (see Methods).</p

Correlates of the average testosterone exposure.

<p>Average testosterone exposure is inversely related to (A) timing of growth spurt and (B) timing of the largest testosterone increase, but is positively related to (C) magnitude of the largest testosterone increase and (D) total testosterone at 17 years.</p

Empagliflozin in Patients with Chronic Kidney Disease

Background The effects of empagliflozin in patients with chronic kidney disease who are at risk for disease progression are not well understood. The EMPA-KIDNEY trial was designed to assess the effects of treatment with empagliflozin in a broad range of such patients. Methods We enrolled patients with chronic kidney disease who had an estimated glomerular filtration rate (eGFR) of at least 20 but less than 45 ml per minute per 1.73 m(2) of body-surface area, or who had an eGFR of at least 45 but less than 90 ml per minute per 1.73 m(2) with a urinary albumin-to-creatinine ratio (with albumin measured in milligrams and creatinine measured in grams) of at least 200. Patients were randomly assigned to receive empagliflozin (10 mg once daily) or matching placebo. The primary outcome was a composite of progression of kidney disease (defined as end-stage kidney disease, a sustained decrease in eGFR to &lt; 10 ml per minute per 1.73 m(2), a sustained decrease in eGFR of &amp; GE;40% from baseline, or death from renal causes) or death from cardiovascular causes. Results A total of 6609 patients underwent randomization. During a median of 2.0 years of follow-up, progression of kidney disease or death from cardiovascular causes occurred in 432 of 3304 patients (13.1%) in the empagliflozin group and in 558 of 3305 patients (16.9%) in the placebo group (hazard ratio, 0.72; 95% confidence interval [CI], 0.64 to 0.82; P &lt; 0.001). Results were consistent among patients with or without diabetes and across subgroups defined according to eGFR ranges. The rate of hospitalization from any cause was lower in the empagliflozin group than in the placebo group (hazard ratio, 0.86; 95% CI, 0.78 to 0.95; P=0.003), but there were no significant between-group differences with respect to the composite outcome of hospitalization for heart failure or death from cardiovascular causes (which occurred in 4.0% in the empagliflozin group and 4.6% in the placebo group) or death from any cause (in 4.5% and 5.1%, respectively). The rates of serious adverse events were similar in the two groups. Conclusions Among a wide range of patients with chronic kidney disease who were at risk for disease progression, empagliflozin therapy led to a lower risk of progression of kidney disease or death from cardiovascular causes than placebo