Optimisation of Mobile Communication Networks - OMCO NET

The mini conference “Optimisation of Mobile Communication Networks” focuses on advanced methods for search and optimisation applied to wireless communication networks. It is sponsored by Research & Enterprise Fund Southampton Solent University. The conference strives to widen knowledge on advanced search methods capable of optimisation of wireless communications networks. The aim is to provide a forum for exchange of recent knowledge, new ideas and trends in this progressive and challenging area. The conference will popularise new successful approaches on resolving hard tasks such as minimisation of transmit power, cooperative and optimal routing

Sex-Dependent Effects of Piromelatine Treatment on Sleep-Wake Cycle and Sleep Structure of Prenatally Stressed Rats

Prenatal stress (PNS) impairs the circadian rhythm of the sleep/wake cycle. The melatonin (MT) analogue Piromelatine (Pir) was designed for the treatment of insomnia. The present study aimed to explore effects of Pir on circadian rhythmicity, motor activity, and sleep structure in male and female rats with a history of prenatal stress (PNS). In addition, we elucidated the role of MT receptors and brain-derived neurotrophic factor (BDNF) to ascertain the underlying mechanism of the drug. Pregnant rats were exposed to different stressors from day seven until birth. Piromelatine (20 mg/kg/day/14 days) was administered to young adult offspring. Home-cage locomotion, electroencephalographic (EEG) and electromyographic (EMG) recordings were conducted for 24 h. Offspring treated with vehicle showed sex-and phase-dependent disturbed circadian rhythm of motor activity and sleep/wake cycle accompanied by elevated rapid eye movement (REM) pattern and theta power and diminished non-rapid eye movement (NREM) sleep and delta power. While Pir corrected the PNS-induced impaired sleep patterns, the MT receptor antagonist luzindol suppressed its effects in male and female offspring. In addition, Pir increased the BDNF expression in the hippocampus in male and female offspring with PNS. Our findings suggest that the beneficial effect of Pir on PNS-induced impairment of sleep/wake cycle circadian rhythm and sleep structure is exerted via activation of MT receptors and enhanced BDNF expression in the hippocampus in male and female offspring

Modeling the plasmasphere to topside ionosphere scale height ratio

A new model of plasmasphere to topside ionosphere scale heights ratio is developed, based on topside electron density (Ne) profiles deduced from the International Satellites for Ionospheric Studies (ISIS)-1 satellite measurements. The model is able to improve operational algorithms for space weather predictions. The topside ionospheric and plasmaspheric scale heights are determined by the lowest and largest gradients of measured profiles, respectively, converted in dh/dlnNe units. The new model depends on four parameters: the month of the year (M), the local time (LT), the geomagnetic latitude (glat), and the ln(O+) density (zO) at the O+-H+ ion transition height. It is designed to replace the old one-dimensional model of the ratio in the TaD (TSM-assisted Digisonde) profiler. The parameters M, LT, and glat are approximated by trigonometric basis functions, while zO is described by a polynomial. A series of models were produced with different number of coefficients (number of terms) of the basis functions. Comparison between models revealed that those with larger number of coefficients can produce unrealistic extremes of the model curves due to the non-uniform sampling of data along the axes. Further considered is the simplest model approximating M, LT, and glat by simple 24 sinusoidal functions and linearly depending on zO. The model description and its 54 coefficients are given in Appendix 1 and can be used by other users for reconstruction of plasmasphere density profiles. The main variation of the ratio along geomagnetic latitude at fixed values of the other model parameters is illustrated in a series of plots

Modeling the plasmasphere to topside ionosphere scale height ratio

A new model of plasmasphere to topside ionosphere scale heights ratio is developed, based on topside electron density (Ne) profiles deduced from the International Satellites for Ionospheric Studies (ISIS)-1 satellite measurements. The model is able to improve operational algorithms for space weather predictions. The topside ionospheric and plasmaspheric scale heights are determined by the lowest and largest gradients of measured profiles, respectively, converted in dh/dlnNe units. The new model depends on four parameters: the month of the year (M), the local time (LT), the geomagnetic latitude (glat), and the ln(O+) density (zO) at the O+-H+ ion transition height. It is designed to replace the old one-dimensional model of the ratio in the TaD (TSM-assisted Digisonde) profiler. The parameters M, LT, and glat are approximated by trigonometric basis functions, while zO is described by a polynomial. A series of models were produced with different number of coefficients (number of terms) of the basis functions. Comparison between models revealed that those with larger number of coefficients can produce unrealistic extremes of the model curves due to the non-uniform sampling of data along the axes. Further considered is the simplest model approximating M, LT, and glat by simple 24 sinusoidal functions and linearly depending on zO. The model description and its 54 coefficients are given in Appendix