Prevalence and Causes of Meatal Stenosis in Circumcised Boys

The aim of this study was to investigate the prevalence and causes of meatal stenosis after circumcision in children. Between October 2018 and April 2019, we carried out a prospective cross-sectional study on 1031 circumcised boys, aged 5 to 8 years (mean age 6.1 years ± 0.3 years), enrolled in the first level of primary school in Oran (Algeria). All enrolled children underwent a genitourinary examination. Moreover, an anonymous questionnaire was filled-in by one of the parents. The screening revealed the presence of meatal stenosis in 185 children, representing a prevalence of 17.9 % of cases (95% CI = 15.6–20.3). Analysis of the results using both the univariate and multivariate mode brought out some common risk factors such as forceful retraction of the prepuce and the use of a healing product: Beta-sitosterol and Hydrocotyl (Centella Asiatica), rarely Trolamine. In addition, this study showed that boys circumcised during their first week of life are twice as likely to develop meatal stenosis than those circumcised between 7 and 12 months (OR = 2.08; 95% CI = 1.10–3.92, p = 0.021). Conclusion: this study showed that stenosis of the urethral meatus is a frequent complication of circumcision. Circumcision in the first week of life, a foreskin that adheres to the glans, and the use of a healing product were associated with the risk of stenosis development.

Development and evolution of methods for optimizing the modes of heating networks

Both in Russia and abroad, energy efficiency problems are relevant, while heat supply systems have significant energy saving reserves, which can be realized by organizing optimal operating modes. In practice, the task of planning modes of heat supply systems is solved by multivariate mode calculations, while the choice of methods for organizing the modes is assigned to the specialist performing the calculations, which does not guarantee the optimality of the obtained modes. Automation of solving these problems is complicated by a number of factors. For these reasons, there are no methods and software systems suitable for wide practical application. This determines the relevance of developing separate methods and programs for calculating optimal modes of heat supply systems. The subject of this article is the tasks and methods of optimizing operation modes of heat supply systems using several objective functions at the same time. The object of application is hydraulically inextricable heat supply systems. It is assumed that the temperature schedule on heat source is set, the heat losses in the networks are eliminated, and their residual value can be neglected. In this case, the task is to optimize the hydraulic mode.

FORCE APPROPRIATION METHOD FOR TWO DEGREES OF FREEDOM NONLINEAR SYSTEM

In this paper, the vibrations of structures are investigated via force appropriation method in which modes are excited individually by forces. Multivariate mode indicator function (MMIF) is used in the modal testing for investigating the prospective nonlinearities in the structures. The method is applied to simulate two degree of freedom with simple nonlinearities. The results are presented and evaluated to indicate that the method has advantages when it comes to involving in mode by mode identification. Results calculated from modal assurance criteria (MAC) and modal purity indicator (MPI) show that the qualities of evaluating a pure normal mode are in satisfactory. This suggests that force appropriation method for nonlinear structures is reliable and efficient, particularly in terms of the isolation of individual modes and determination of high quality modal parameters.

ATYPICAL IMAGING CHARACTERISTIC OF OLIGODENDROGLIOMA

Background: There has been the dearth of doctors choosing the postgraduate specialties that were outside the core clinical disciplines. This would no longer impact negatively in the distribution of Doctors in the less sought out specialties in terms of service delivery and medical education. Objectives: The present study was done to determine the career preferences of final year medical students specifically as regards to their choice of chemical pathology and factors influencing such choice. Methods: The study was a Descriptive cross sectional study. A questionnaire was self administered by the authors on all the final year medical students of Usmanu Danfodio University, Sokoto. Data was analyzed with SPSS version 20.0 Results: Out of the 60 respondents only 3(5%) had interest in pursuing chemical pathology as a postgraduate medical career. The medical students with ages ranging from 20 to 24 years were more likely to choose chemical pathology as a career using the multivariate mode

Noise-Assisted Instantaneous Coherence Analysis of Brain Connectivity

Characterizing brain connectivity between neural signals is key to understanding brain function. Current measures such as coherence heavily rely on Fourier or wavelet transform, which inevitably assume the signal stationarity and place severe limits on its time-frequency resolution. Here we addressed these issues by introducing a noise-assisted instantaneous coherence (NAIC) measure based on multivariate mode empirical decomposition (MEMD) coupled with Hilbert transform to achieve high-resolution time frequency representation of neural coherence. In our method, fully data-driven MEMD, together with Hilbert transform, is first employed to provide time-frequency power spectra for neural data. Such power spectra are typically sparse and of high resolution, that is, there usually exist many zero values, which result in numerical problems for directly computing coherence. Hence, we propose to add random noise onto the spectra, making coherence calculation feasible. Furthermore, a statistical randomization procedure is designed to cancel out the effect of the added noise. Computer simulations are first performed to verify the effectiveness of NAIC. Local field potentials collected from visual cortex of macaque monkey while performing a generalized flash suppression task are then used to demonstrate the usefulness of our NAIC method to provide highresolution time-frequency coherence measure for connectivity analysis of neural data.