Impaired hypothalamic-pituitary-gonadal axis function in men with diabetes mellitus

In view of association of diabetes mellitus and male infertility, present study was designed to investigate the functional status of hypothalamic pituitary gonadal (HPG) axis in diabetic men. Thirty-five diabetic men (BMI 22.24±0.21) in the age group 20–40 (30.6±4.7) years were selected. Twenty-five healthy men (BMI 23.85±0.25), in the same age group (29.5±4.8) served as control. Blood samples were collected for hormonal and biochemical estimations. Diabetic men had significantly low serum testosterone with low LH and FSH, hypercholesterolemia, hypertriglyceridemia, hypoalbuminemia and increased oxidative stress. Low serum testosterone in diabetic men was accompanied by low LH and FSH; the inability of the pituitary gland to respond appropriately to a decline in testosterone implying central effect of high serum glucose on the interaction between the nervous and endocrine system. Nutritional deficiency, increased oxidative stress and increased aromatase activity due to excessive body fat might have also contributed to low serum testosterone.     

The experiment of Michelson and Morley

Light was assumed to propagate in a medium called ether which was all pervading and stationary. Earth’s motion through ether was expected to have an effect on the velocity of light in the direction of the relative motion by the law of addition of velocities. Michelson–Morley experiment used an interferometric technique to detect this effect and got a null result, which was the first strong evidence against existence of ether and eventually had a natural explanation in special theory of relativity.     

Story of superconductivity

Electricity is carried through metallic wires, called conductors. In the process, electrons move through metallic conductors that offer resistance (the value depends on the particular metal used), to the passage of electrons. This leads to the production of heat and loss of energy. This heating process is utilised in many electrical devices. However, for transmission of electrical energy from the power plants to the user and in many other applications, it would be a great boon if no energy was lost to resistance. The discovery of superconductivity by Heike Kamerlingh Onnes in 1911 at Leiden, offered a glimmer of hope to make this dream possible. It was a discovery totally unexpected at that time, and we owe this discovery to the painstaking and methodical investigations of Onnes–first to produce very low temperatures, and then measure properties of materials at these freezing temperatures.     

Hollywood studio filmmaking in the age of Netflix: a tale of two institutional logics

Journal of Cultural Economics - Online streaming services are challenging long-standing decision-making processes in the traditional motion picture industry, thus placing Hollywood major studios at...     

Great experiments in physics

In Part 1 of this article, we described masers. In this part, we describe lasers, their optical counterpart.     

Limitations of autopilot design for controlling a statically unstable flexible interceptor

The Mach number, angle of attack and altitude of operation for an interceptor vary widely during the course of its trajectory. As a result, the interceptor Center of Pressure (CP) locations move significantly around a given Center of Gravity (CG) location at these operating conditions. This results in an inevitable variation in aerodynamic static stability leading to stable and unstable operating regions. In order to ensure good speed of response during the interceptor homing phase, lesser static stability is desirable. Hence the requirement to handle aerodynamic instability at some other operating conditions in the interceptor envelope become inevitable. Since flexibility has a strong bearing on autopilot design, it becomes necessary to control unstable operating points in the presence of flexibility modes. Despite the static stability variation, aerodynamic design can control the level of maximum instability of the configuration. Hence the maximum static instability the autopilot can handle has to be specified for aerodynamic configuration design. This paper brings out the limitations of autopilot design in controlling an unstable interceptor with low bending mode frequencies in terms of maximum instability the autopilot design can handle, which serves as an important input for aerodynamic design.     

A study of thyroid status in hyperemesis gravidarum

Study was undertaken to assess thyroid status in hyperemesis gravidarum. 150 women pregnant with <20 weeks of gestation were selected randomly and out of these 100 women presenting with hyperemesis formed study group while 50 normal pregnant women served as controls. 53% of hyperemetic pregnant women were primigravidae and 82% of pregnant women presented with vomiting at less than 12 weeks of gestation. Statistically significant, 22% of hyperemetic women had increased serum T₃ levels while T₄ levels were increased in 67% of women in study group as compared to 8% and 16% respectively in control group. TSH levels were decreased in 18% of hyperemetic women as compared to 8% in control group with decrease in mean TSH level statistically significant. 22% of hyperemetic women had electrolyte disturbances and 7% were ketonuric. In clinically euthyroid women, biochemically altered thyroid function can attribute to vomiting and its prolongation to second trimester