Some Considerations on the Lessons Learnt from the Cavalcade of Changes in Physics’ Models

This paper presents an attempt to explain and to make predictions on the change process in the physics’ models. One important goal of the search for such an attempt is to develop an approach that is able to have a certain degree of predictability of at least the direction in which the models will change, assuming that in general it is possible to have an answer to the question, whether this change process has a certain rhythmicity and follows some patterns, or it is a totally chaotic one. The paradigmatic approach of Kuhn on changes in science was one of the starting points for this search, and the use of topological aspects to describe models in physics was a starting point of the search for the approach. By using notions of categories and of syzygies from mathematics, a new approach is proposed to evaluate the direction of changes in science and technology, with an example from the nuclear physics and technology

The management of tubo-ovarian abscesses associated with appendicitis

A relatively uncommon medical complication, the tubo-ovarian abscess (TOA) can result from ascending pelvic infection in the female genital tract. The paper aims at exploring the characteristics of patients with TOA and at comparing the outcomes of the surgical management with postoperative recovery. A retrospective analysis of 25 cases diagnosed with bilateral, right or left TOA at “St. Apostol Andrei” Emergency Clinical County Hospital Constanta, Romania between January 2019 and December 2020 was performed. The patients’ clinical characteristics, age, environment of origin, socio-economic background, educational level, the means of contraception used, surgical procedures, and postoperative recovery were analyzed. Out of the 25 cases, 40% presented bilateral TOA, 32% right TOA and 28% left TOA and left adnexectomy. In 3 patients (37.5%) with right TOA, appendicectomy was also performed. In 72% of the cases, a median pubic-umbilical incision was performed. The remaining 7 patients (28%) with left TOA underwent Pfannenstiel incision. All cases had a favorable postoperative evolution, the patients being discharged 5-9 days after surgery, benefiting from antibiotic therapy 10 days after their discharge. The co-existence of appendicitis and adnexal pathology should raise awareness for adopting a surgical strategy in order to prevent postoperative complications

Advanced Sea Clutter Models and their Usefulness for Target Detection

International audienceRobust naval target detection is of significant importance to national security, to navigation safety, and to environmental monitoring. Here we consider the particular case of high resolution coastal radars, working at low grazing angles. The robustness of detection heavily relies on the appropriate knowledge of two classes of backscattered signals: the target echo, and the sea echo. The latter, usually regarded as a noise, is known as the sea clutter. This particular combination, of high resolution and low grazing angles, raises considerable challenges to radar processing algorithms. Specifically, the probability density function governing the sea clutter amplitude is no more Gaussian and a lot of effort has been aimed at characterizing it. Three approaches are reviewed here: the stochastic, texture and chaotic models. While the stochastic models represent an essay to extend classical detection theory to radars operating in marine environment, the other two models represent entirely new paradigms. Since each model has its strengths and weaknesses and more testing on real data is required to credibly validate any of the proposed models, a definitive conclusion is far from reach. However, critical comments, as well as experimentally supported conclusions are presented in the paper

Pain management in the right iliac fossa during the Covid-19 pandemic

Abdominal pain in the right iliac fossa in women may be caused by a complicated ovarian cyst, adnexitis, and appendicitis. The paper analyses the characteristics of patients with right iliac fossa pain admitted during the Covid-19 pandemic. A retrospective analysis on 25 cases with abdominal pain in the right iliac fossa admitted to “St. Apostol Andrei” Emergency County Clinical Hospital Constanta, Romania between March 2020 and March 2021 was performed. In 52% of the cases, the symptomatology remitted with antispasmodics, 4 (16%) patients had cystic torsion and right adnexectomy (group A, without adnexa), 6 (24%) patients had ruptured cysts and right cystectomy, and 2 (8%) had immediate cystectomy together with appendectomy due to signs of peritoneal irritation (group B, adnexa retained). The age, the signs and the symptoms, as well as the inpatient diagnosis in group A were lower compared to patients in group B. The ovarian cyst can become a major surgical emergency if twisted or ruptured and it reaches an important vascular source, especially if it is associated with acute appendicitis, which often poses problems of differential diagnosis. The collaboration between gynecologists and surgeons is essential in the optimal therapeutic solution of these cases

Characterization of Complex Signals Using Time-Frequency-Phase Concept

ISSN 1843-3391International audienceA real environment identification system is based on observations which are often non stationary. A mechanical machine generating acoustic signals or an underwater environment are examples of systems characterized by non-stationary signals. Their analysis in the time-frequency domain is well adapted so that it offers appropriated structures which are good candidates for the information post-processing. The system architecture is defined through three blocks (detection of regions of interest, observations segmentation and separation, analytical characterization). This architecture is mainly based on joint use of time, frequency and local phase analysis. More precisely, the phase information will be locally analyzed, using generalized instantaneous moments, on the time-frequency regions previously selected thanks to the time-frequency grouping algorithm. This architecture permits an efficient scheme to solve the constraints brought by this type of signals with a complex time-frequency behavior and by the human operator to reduce this tasks in the decision process. Examples from underwater behavior (underwater mammals vocalizations) will prove the efficiency of the proposed approach

Systemic approach explored in the context of passive target tracking

International audienceor obvious reasons of cost, discretion and reliability costs, locating and tracking aerial targets under an electromagnetically completely passive paradigm, relying exclusively on illuminators of opportunity, is very appealing for military but also civilian tasks. Such a passive radar system could exploit signals emitted by existing commercial television or radio stations or even satellite signals, such as the ones belonging to the GPS. The paper considers target locating and tracking using a network of passive receivers and/or non-cooperative illuminators (a multi-static radar configuration) by making use of the Doppler shift only. A novel concept, the systemic approach, is used to combine and interpret information available from different sensors. Both the formalization of the problem and the hardware and software implementation are presented. Implementation makes use of multi-component polynomial phase signal models and genetic algorithms. For increased performance, implementation on FPGA is envisaged. The paper ends with conclusions and perspectives

Advanced Sea Clutter Models and their Usefulness for Target Detection

International audienceRobust naval target detection is of significant importance to national security, to navigation safety, and to environmental monitoring. Here we consider the particular case of high resolution coastal radars, working at low grazing angles. The robustness of detection heavily relies on the appropriate knowledge of two classes of backscattered signals: the target echo, and the sea echo. The latter, usually regarded as a noise, is known as the sea clutter. This particular combination, of high resolution and low grazing angles, raises considerable challenges to radar processing algorithms. Specifically, the probability density function governing the sea clutter amplitude is no more Gaussian and a lot of effort has been aimed at characterizing it. Three approaches are reviewed here: the stochastic, texture and chaotic models. While the stochastic models represent an essay to extend classical detection theory to radars operating in marine environment, the other two models represent entirely new paradigms. Since each model has its strengths and weaknesses and more testing on real data is required to credibly validate any of the proposed models, a definitive conclusion is far from reach. However, critical comments, as well as experimentally supported conclusions are presented in the paper

HPV and HIV Coinfection in Women from a Southeast Region of Romania—PICOPIV Study

Background and Objectives: Romania faces one of the highest cervical cancer burdens in Europe though it is a preventable cancer through population screening by cytology and human papillomavirus (HPV) detection. Also, it has one of the highest incidences of human immunodeficiency virus (HIV) infection. HPV and HIV coinfection are frequently encountered. The aim of study was to establish the prevalence of HPV infection among HIV-positive women in Southeast Region of Romania, to genotype high risk HPV types -and to correlate the results with clinical data and cytological cervical lesions. Materials and Methods: 40 HIV-positive women were screened for HPV types and for cytological cervical lesions. The findings were evaluated in correlation with CD4 cell counts, HIV viral load, age at first sexual intercourse, number of sexual partners, vaginal candidiasis, and Gardnerella using statistical methods. Results: 19/40 (47.5%) women were positive for HPV types, 63.15% infected with single HPV type and 36.85% with multiple HPV types. The most frequent types were type: 31 (42.1%), 56 (31.57%), 53 (15.78%). On cytology, 34 (85%) women were found with NILM of which 38.23% were HPV-positive. Fifteen percent of women had abnormal cytology (three ASC-US, three LSIL), and all of them were HPV-positive. Through analyzing the value of CD4 count, women with CD4 count ≤ 200 cells/μL were found to be significantly more likely to be infected with HPV; meanwhile there was no correlation between the detection of HPV types and HIV viral load. Candida or Gardnerella were more often associated with HIV-positive women with HPV, than in women without HPV. Conclusions: Infection with HPV types is common among HIV-positive women in the Southeast Region of Romania and it is associated with age at the beginning of sexual life, number of sexual partners, CD4 value, vaginal candidiasis, and Gardnerella infection