Bifurcations of mixed-mode oscillations in three-timescale systems: An extended prototypical example.

We study a class of multi-parameter three-dimensional systems of ordinary differential equations that exhibit dynamics on three distinct timescales. We apply geometric singular perturbation theory to explore the dependence of the geometry of these systems on their parameters, with a focus on mixed-mode oscillations (MMOs) and their bifurcations. In particular, we uncover a novel geometric mechanism that encodes the transition from MMOs with single epochs of small-amplitude oscillations (SAOs) to those with double-epoch SAOs; the former feature SAOs or pseudo-plateau bursting either "below" or "above" in their time series, while in the latter, SAOs or pseudo-plateau bursting occur both "below" and "above." We identify a relatively simple prototypical three-timescale system that realizes our mechanism, featuring a one-dimensional S-shaped 2-critical manifold that is embedded into a two-dimensional S-shaped critical manifold in a symmetric fashion. We show that the Koper model from chemical kinetics is merely a particular realization of that prototypical system for a specific choice of parameters; in particular, we explain the robust occurrence of mixed-mode dynamics with double epochs of SAOs therein. Finally, we argue that our geometric mechanism can elucidate the mixed-mode dynamics of more complicated systems with a similar underlying geometry, such as a three-dimensional, three-timescale reduction of the Hodgkin-Huxley equations from mathematical neuroscience.

Changes of Hippocampal Noradrenergic Capacity in Stress Condition.

This study aimed to investigate the effects of chronic restraint stress (CRS) on the protein levels of dopamine-ß-hydroxylase (DBH), noradrenaline transporter (NET), vesicular monoamine transporter 2 (VMAT2) and brain-derived neurotrophic factor (BDNF), as well as the concentration of noradrenaline (NA) in the rat hippocampus. The investigated parameters were quantified by Western blot analyses and ELISA kits. We found that CRS increased the protein levels of DBH by 30 %, VMAT2 by 11 %, BDNF by 11 % and the concentration of NA by 104 %, but decreased the protein levels of NET by 16 % in the hippocampus of chronically stressed rats. The molecular mechanisms by which CRS increased the hippocampal NA level are an important adaptive phenomenon of the noradrenergic system in the stress condition.

Video analysis of acute injuries and referee decisions during the 24th Men's Handball World Championship 2015 in Qatar.

Although handball is a contact sport with a high risk of acute match injuries, their mechanisms have not yet been investigated. We aimed to describe the mechanisms of acute match injuries in elite male handball and evaluate referee performance in injury situations. Based on injury surveillance from the 24th Men's Handball World Championship 2015 in Qatar, injury situations and the referee decisions were identified on video footage. A total of 55 injury situations and 37 referee decisions were included for analysis. The injury situations were analyzed individually by five handball experts, followed by a consensus meeting. An expert referee panel performed individual blinded evaluation of the referee decisions, followed by an online consensus meeting. Injuries were evenly distributed among attackers (n = 29) and defenders (n = 26). The most frequent injury cause was contact trauma due to a tackle (n = 27). At the time of injury, attackers were most frequently performing a jump shot (n = 9), while defenders were completing a tackle (n = 10). Defenders most commonly tackled the throwing arm (n = 7) or toward the head/face region (n = 6) of injured attackers, while attackers most frequently hit injured defenders with the knee during jump shots (n = 5). Agreement between the referees and the expert panel was weak (kappa: 0.22, 95% CI 0.07 to 0.36), with substantially more lenient rule interpretation by the referees. Our results suggest that stricter refereeing and rule amendments should be considered to prevent acute match injuries in elite handball, especially in relation to tackling episodes when an attacker is performing a jump shot.

Antioxidant status and sex hormones in women with complex endometrial hyperplasia.

Endometrial tissue is under a strong influence of sex hormones. These hormones are considered as developmental factors of endometrial hyperplasia and endometrial cancer. We examined the influence of gonadotropins (follicle-stimulating and luteinizing hormone) and sex hormones (estradiol, progesterone) on oxidant/antioxidant parameters in blood and endometrial tissue of women with complex endometrial hyperplasia. In blood, superoxide dismutase activity was significantly higher in luteal phase and postmenopause compared to the follicular phase. A significant phase-related difference of glutathione peroxidase and glutathione reductase activity was recorded in the endometrium. Both enzymes had lower activity in luteal phase and postmenopause compared to the follicular phase. The linear regression analysis of individual hormonal variables against antioxidant parameters showed negative correlation between glutathione peroxidase activity and gonadotropin concentrations in the endometrium. The regression of hyperplastic to normal endometrium is the purpose of conservative treatment based on administration of progestogens or gonadotropin-releasing hormone analogues. Our findings indicate that gonadotropins influence the antioxidant enzymes activity in women with complex endometrial hyperplasia, which may affect disease development. Further studies are needed to clarify the molecular basis of hormone action on antioxidant system that may potentially initiate a development of treatments based on redox-dependent mechanism.

Antioxidant status in blood of gynaecological patients: influence of diagnosis and reproductive factors.

Cancer of the reproductive tract is an important cause of morbidity and mortality among women worldwide. In this study we evaluated the influence of diagnostic categories, age and reproductive factors on antioxidant enzymes and lipid hydroperoxides in the blood of gynaecological patients diagnosed with endometrial polyp, myoma, hyperplasia simplex, hyperplasia complex and endometrial adenocarcinoma. Multivariate regression analysis was used to assess the association of diagnosis, age, parity, abortions and abnormal uterine bleeding with the examined parameters. Diagnosis provided the best predictive model for superoxide dismutase, catalase and glutathione peroxidase activities, and also for the lipid hydroperoxide level. Abortions fitted the best predictive model for superoxide dismutase activity. A significant correlation was also found between the predictor variables themselves. This study showed that reproductive and other factors may be associated, at least partially, with antioxidant capacity and ability to defend against the oxidative damage in gynaecological patients with various diagnoses.

Outbreak of West Nile virus infection among humans in Serbia, August to October 2012.

We describe the first reported outbreak of West Nile virus (WNV) infection in humans in Serbia in August to October 2012 and examine the association of various variables with encephalitis and fatal outcome. Enzyme-linked immunosorbent assay (ELISA) was used for detection of WNV-specific IgM and IgG antibodies in sera and cerebrospinal fluid. A total of 58 patients (mean age: 61 years; standard deviation: 15) were analysed: 44 were from Belgrade and its suburbs; 52 had neuroinvasive disease, of whom 8 had meningitis, while 44 had encephalitis. Acute flaccid paralysis developed in 13 of the patients with encephalitis. Age over 60 years and immunosuppression (including diabetes) were independently associated with the development of encephalitis in a multivariate analysis: odds ratio (OR): 44.8 (95% confidence interval (CI): 4.93­408.59); p=0.001 (age over 60 years); OR: 10.76 (95% CI: 1.06­109.65); p=0.045 (immunosuppression including diabetes). Respiratory failure requiring mechanical ventilation developed in 13 patients with encephalitis. A total of 35 patients had completely recovered by the time they were discharged; nine patients died. The presence of acute flaccid paralysis, consciousness impairment, respiratory failure and immunosuppression (without diabetes) were found to be associated with death in hospital in a univariate analysis (p<0.001, p=0.007, p<0.001 and p=0.010, respectively).

Nuclear abnormalities of marine fish erythrocytes.

The aim of this study was to monitor erythrocyte nuclear abnormalities (NA) including micronuclei (MN) in cultured and wild sea bass Dicentrarchus labrax and wild mullet Mugil spp. Seasonal sampling was performed at seven locations along the eastern coast of the Adriatic Sea. The frequency of NA and MN was positively correlated to temperature (NA: P < 0.05, r = 0.11; MN P < 0.05, r = 0.10), and there was also a positive correlation between NA and MN frequency (P < 0.001, r = 0.43). The lowest NA and MN values for both fish species were recorded in spring, while the highest were recorded in autumn. Significantly higher frequency of NA was seen in D. labrax compared to Mugil spp., while MN frequency was low in both species and not significantly different. There was no significant difference in NA and MN frequency between cultured and wild D. labrax sampled in the same month, and there was no difference between wild Mugil spp. sampled near or far from fish farms. In view of sampling sites, the highest values were detected in fishes from the Limski Channel, the lowest from the Janjina location.

Classification accuracy of algorithms for blood chemistry data for three aquaculture-affected marine fish species.

The objective of this study was determination and discrimination of biochemical data among three aquaculture-affected marine fish species (sea bass, Dicentrarchus labrax; sea bream, Sparus aurata L., and mullet, Mugil spp.) based on machine-learning methods. The approach relying on machine-learning methods gives more usable classification solutions and provides better insight into the collected data. So far, these new methods have been applied to the problem of discrimination of blood chemistry data with respect to season and feed of a single species. This is the first time these classification algorithms have been used as a framework for rapid differentiation among three fish species. Among the machine-learning methods used, decision trees provided the clearest model, which correctly classified 210 samples or 85.71%, and incorrectly classified 35 samples or 14.29% and clearly identified three investigated species from their biochemical traits.

Improving national surveillance of new HIV diagnoses.

The purpose of national HIV surveillance is to track and summarize trends in newly diagnosed cases as an indicator of HIV transmission within Canada, and supports the development and evaluation of programs and policies for prevention, testing and delivery of care. Accurately capturing and interpreting trends in HIV diagnoses within national surveillance becomes complicated when there is movement of people within a country or when individuals are diagnosed with HIV prior to migrating to a new country. This has been identified as an issue in other countries, including Australia, New Zealand and Switzerland. The Public Health Agency of Canada (PHAC) recently assessed this in Canada after noting a rise in new HIV cases in Canada between 2014 to 2017. An environmental scan was conducted to better understand how new and previously diagnosed cases of HIV were recorded by and reported to PHAC from provincial and territorial (PT) public health authorities. It was discovered there was variation with respect to the reporting of cases who had received a new diagnosis of HIV within the province or territory, but who had previously received an HIV diagnosis from another PT or another country. Five PTs included cases previously diagnosed in another Canadian PT within the HIV surveillance data reported to PHAC and nine PTs included people who were diagnosed with HIV outside of Canada. The provincial and territorial public health authorities then reviewed HIV surveillance data from 2007 to 2017 to identify cases using a common definition of "previous HIV-positive test result". This included any case who gave a history, or had laboratory evidence, of an HIV-positive result from another PT or another country before presenting for care in the province or territory where they now resided. When these cases were subtracted from the total, a revised number of new HIV diagnoses was calculated for Canada. Re-analysis of surveillance data using this common definition for 2007 to 2017 explained more than half of the increase in HIV cases that had been documented in Canada over the last four years. In the future, national surveillance data will be calculated adopting this new common definition of a previous positive test result, in order to more accurately describe the trends in HIV transmission occurring in Canada.

HIV in Canada-Surveillance Report, 2018.

BACKGROUND: Human immunodeficiency virus (HIV) is a global public health issue, with an estimated 36.9 million people living with HIV in 2017. HIV has been reportable in Canada since 1985 and the Public Health Agency of Canada (PHAC) continues to monitor trends in new HIV diagnoses. OBJECTIVE: The objective of this surveillance report is to provide an overview of the epidemiology of all reported diagnoses of HIV in Canada since 1985 with a focus on 2018 overall, and by geographic location, age group, sex, and exposure category. METHODS: PHAC monitors HIV through the national HIV/AIDS Surveillance System, a passive, case-based system that collates nonnominal data that is voluntarily submitted by all Canadian provinces and territories. Descriptive epidemiological analyses were conducted on national data and those relating to specific populations provided by Immigration, Refugees and Citizenship Canada and the Canadian Perinatal HIV Surveillance Program. RESULTS: In 2018, a total of 2,561 HIV diagnoses were reported in Canada, an increase of 8.2% compared with 2017. The national diagnosis rate increased to 6.9 per 100,000 population in 2018 from 6.5 per 100,000 population in 2017. Saskatchewan reported the highest provincial diagnosis rate at 14.9 per 100,000 population. The 30-39 year age group continued to have the highest HIV diagnosis rate at 15.4 per 100,000 population. Overall, the diagnosis rate for males continued to be higher than that of females (9.8 versus 4.0 per 100,000 population, respectively); however, females experienced a larger increase in reported cases and diagnosis rate. The gay, bisexual and other men who have sex with men (gbMSM) exposure category continued to represent the highest proportion of all reported adult cases (41.4%), though the proportion has decreased over time. Five perinatal HIV transmissions were documented, three were related to the mother not receiving perinatal antiretroviral therapy prophylaxis. CONCLUSION: The number and rate of reported HIV cases in Canada increased in 2018, gbMSM continued to account for the largest exposure category and the number and rate of reported HIV cases among women increased. PHAC will continue to work with its national partners to refine the collection, analysis and publication of national data to better understand the burden of HIV in Canada.

Morphometric characteristics of the optic canal and the optic nerve.

BACKGROUND: The optic nerve (ON), a major component of the visual system, is divided into four segments: the intrabulbar (IB), the intraorbital (IO), the intraca- nalicular (ICn) and the intracranial (ICr). The ICr ends with the two nerves partially decussating in the optic chiasm (OCh). The purpose of this study is to provide a detailed description of the dimensions of the OC (the diameter and the surface area of its foramina and the central segment, as well as the length of the OC and the thickness of its walls) as well as the ON (the length of the ON segments, the diameter of the ICn segment of the ON, the angle of decussation in the OCh, as well as the distance between the two ON at the cranial foramen of the OC). MATERIALS AND METHODS: The acquired data was then used to estimate the volu- me of the OC and the ICn segment of the ON. The morphometric research was performed on 25 cadavers (17 male and 8 female) and 30 skulls. RESULTS: The surface area of the central segment of the OC was significantly smaller than the cranial foramen (p = 0.02) and the orbital foramen (p = 0.009). The inferior wall of the OC was significantly shorter than the other OC walls (p < 0.0001). The IO segment of the ON was the longest, where the difference to the ICn and ICr was statistically significant (p < 0.0001). The surface area of the ON at the cranial foramen was significantly larger than the surface area at the central segment of the OC (p = 0.02) and orbital foramen (p < 0.0001). The difference between the surface areas of the ON at the orbital foramen and the central segment of the OC was also statistically significant (p = 0.01). The estimated volume of the OC was calculated to be 190.72 mm3, and the volume of the ICn segment of the ON was estimated to be 50.25 mm3. CONCLUSIONS: It is absolutely crucial to open the central segment of the OC when decompressing the ON, due to the narrowing of the OC in this segment.

Newly diagnosed cases of HIV in those aged 50 years and older and those less than 50: 2008-2017.

BACKGROUND: Canada's population is aging, with nearly forty percent of Canadians aged 50 years or more. As the population ages, unique challenges related to health are becoming evident, including increasing rates of sexually transmitted and bloodborne infections. Understanding the epidemiology of HIV in older adults is important to guide prevention and control programs. OBJECTIVE: To assess trends in newly diagnosed cases of HIV in Canada among those aged 50 years and older (≥50 years) and those aged less than 50 (<50 years), and to compare their basic demographic characteristics and exposure categories for the period of 2008 to 2017. METHODS: National surveillance of HIV is conducted by the Public Health Agency of Canada through voluntary submission of data by provincial/territorial public health authorities. Descriptive analyses were conducted on reported cases of HIV between January 1, 2008, to December 31, 2017 to compare the demographic profiles and exposure category for the two age groups. RESULTS: Between 2008 and 2017, the proportion of newly diagnosed HIV cases among those ≥50 years increased from 15.1% to 22.8%. The HIV diagnosis rates for both older males and older females increased over time, with a relatively higher increase for females. A higher proportion of newly diagnosed HIV cases were male in the older group (81.2%) compared to the younger group (74.6%). Among both older and younger males, the most common exposure category for HIV was being gay, bisexual and other men who have sex with men (gbMSM), followed by heterosexual contact and injection drug use; however, the relative proportions varied by age with the gbMSM category being higher in the <50 group. CONCLUSION: In Canada, over 20% of all newly diagnosed cases of HIV are now in people 50 years of age and older. HIV testing and prevention initiatives, historically aimed at younger populations, may not have the same impact for older populations. These data can be used to inform future public health actions designed to address HIV in older populations.

Investigation of properties of electrochemically synthesized iron oxide nano-powders.

Nano-sized powders of iron oxides have been synthesized electrochemically at temperatures in the range of 295-361 K, and current densities in the range of 200-1000 mA dm(-2). The structure and morphology of the powders were investigated by X-ray diffraction and scanning electron and transmission electron microscopy techniques. Their infrared absorption spectra, specific heat C(p)(T) and magnetic susceptibility chi(T) temperature dependences are also determined. The obtained powders consist of two phases, each possessing distinguished characteristics: the one formed of large plates and the other of whiskers. By appropriate adjustment of the synthesis conditions, it is possible to change features and relative abundances of the two phases, and that way to control morphology and other powder properties. Relaxation and transformation of the phases under external influences was also investigated, and the optimal procedure for preparation and stabilization of iron oxide nano-sized powders with desired characteristics was established.

Surface resistivity estimation by scanning surface potential microscopy.

Nickel was sputter deposited on a glass with a thin film thickness of 600 nm under either in an argon atmosphere or under a partial pressure of nitrogen of either 1.3 x 10(-4) or 4 x 10(-4) mbar. Atomic force microscopy and scanning surface potential microscopy (SSPM) were used to study the morphology and to estimate the surface resistivity of the obtained Ni thin films taking into account surface-roughness effects. For the three samples investigated, the surface resistivity values as estimated using SSPM were in good agreement with the results obtained by standard four-point probe measurements.

Postoperative complications--massive transfusions in radical malignant gynecological surgeries.

At the Institute of Gynecology and Obstetrics we examined 24 women who were radically operated on and received massive transfusions during the intraoperative and postoperative period. Twelve developed massive transfusion complications such as urticaria, fever, and respiratory insufficiency known as TRALI (transfusion-related acute lung injury).

Increased AFP as an indicator of ovarian carcinoma and fetal kidney carcinoma--case report.

We examined a young primipara with increased alpha-fetoprotein (AFP) values and cystic tumefaction of the right ovary. Having in mind a mild decrease in ovarian artery resistance index (RI) and suspected findings of fetal kidney, this situation was delicate due to its double pathology which was later confirmed. Wilms' tumor is the most common urogenital tumor in childhood, and it is detectable in the prenatal period by ultrasound examination. In utero kidney biopsy confirms diagnosis and facilitates decisions concerning the course of pregnancy. Relative risk of intervention limits this diagnostic procedure for indicated cases.

Cervical and duodenal polyps and their malignant alterations--case report.

During routine examination of a 32-year-old patient, a cervical polyp was found and CIN III was confirmed by biopsy. After performing colposcopy, biopsy and establishing CIN III as well as performing gastroscopy where a duodenal polyp was found, thorough diagnostic exams and therapy were carried out. Complete duodenal resection and conization were performed. The medical board decided that neither further radiation nor chemotherapy was needed.

Therapeutic potential of controlled drug delivery systems in neurodegenerative diseases.

Several compounds that exhibit a therapeutic effect in experimental models of neurodegenerative diseases have been identified over recent years. Safe and effective drug delivery to the central nervous system is still one of the main obstacles in translating these experimental strategies into clinical therapies. Different approaches have been developed to enable drug delivery in close proximity to the desired site of action. In this review, we describe biodegradable polymeric systems as drug carriers in models of neurodegenerative diseases. Biomaterials described for intracerebral drug delivery are well tolerated by the host tissue and do not exhibit cytotoxic, immunologic, carcinogenic or teratogenic effects even after chronic exposure. Behavioral improvement and normalization of brain morphology have been observed following treatment using such biomaterials in animal models of Parkinson's, Alzheimer's and Huntington's diseases. Application of these devices for neuroactive drugs is still restricted due to the relatively small volume of tissue exposed to active compound. Further development of polymeric drug delivery systems will require that larger volumes of brain tissue are targeted, with a controlled and sustained drug release that is carefully controlled so it does not cause damage to the surrounding tissue.

Torsion of carcinomatous ovarian cyst and polycystic omental diseases--case report.

A middle-aged patient, without any positive personal or familial history was urgently hospitalized and, after primary diagnostic procedures, treated by surgery for torsion and acute abdomen. During the procedure, torsioned ovarian cyst and a probable perforated omental cyst were found. Primary ovarian cancer and secondary polycystic metastatic echoes of the omentum were established by histopathology.

The incidence of vulvar pathology and vulvectomy within risk and non-risk groups.

At the Institute of Gynecology and Obstetrics over a period of five years, more than 180,000 women were examined; 580 simple and 178 radical vulvectomies were performed.