Exogenous capture accounts for fundamental differences between prosaccade and antisaccade performance

Oculomotor circuits generate eye movements based on the physical salience of objects and current behavioral goals, exogenous and endogenous influences, respectively. However, the interactions between exogenous and endogenous mechanisms and their dynamic contributions to target selection have been difficult to resolve because they evolve extremely rapidly. In a recent study (Salinas et al., 2019), we achieved the necessary temporal precision using an urgent variant of the antisaccade task wherein motor plans are initiated early and choice accuracy depends sharply on when exactly the visual cue information becomes available. Empirical and modeling results indicated that the exogenous signal arrives ~80 ms after cue onset and rapidly accelerates the (incorrect) plan toward the cue, whereas the informed endogenous signal arrives ~25 ms later to favor the (correct) plan away from the cue. Here, we scrutinize a key mechanistic hypothesis about this dynamic, that the exogenous and endogenous signals act at different times and independently of each other. We test quantitative model predictions by comparing the performance of human participants instructed to look toward a visual cue versus away from it under high urgency. We find that, indeed, the exogenous response is largely impervious to task instructions; it simply flips its sign relative to the correct choice, and this largely explains the drastic differences in psychometric performance between the two tasks. Thus, saccadic choices are strongly dictated by the alignment between salience and behavioral goals.

Ultrasound Imaging of Acquired Myometrial Pseudoaneurysm: The Role of Manipulators as an Unusual Cause during Laparoscopic Surgery

An acquired uterine artery myometrial pseudoaneurysm can occur due to inflammation, trauma, or iatrogenic causes, such as surgical procedures, and can lead to profuse bleeding. The efficacy of uterine manipulators in gynecological surgery, particularly as a cause of a pseudoaneurysm, has been poorly discussed in the literature. In this paper, we discuss a case of a 39-year-old woman with profuse uterine bleeding that occurred seven days after operative laparoscopic surgery for endometriosis. The color Doppler ultrasound better evoked the arterial-like turbulent blood flow inside this cavity. These sonographic features were highly suggestive of uterine artery pseudoaneurysm, presumably related to a secondary trauma caused by the manipulator. The diagnosis was subsequently re-confirmed by angiography, and the patient was treated conservatively with uterine artery embolization. Ultrasound has been shown to be a valuable and safe tool for imaging pseudoaneurysm and guiding subsequent interventional procedures. Accordingly, we briefly review the most suitable manipulators used in benign gynecological surgeries to verify if the different types in use can guide the surgeon towards the correct choice according to surgical needs and thus prevent potentially dangerous trauma.

Reinsurance and Solvency Capital: Mitigating Insurance Companies’ Ruin Probability

ABSTRACT Context: insurance companies are important to society, since they guarantee financial protection to individuals from property losses, in addition to fostering the capital market through the allocation of guarantee assets. Thus, it is essential to evaluate the instruments that guarantee their long-term financial solvency. Among them are the adoption of reinsurance treaties, the sizing of the solvency capital, and the actuarial modeling of risk processes, which allow the measurement of the ruin probability. Objective: estimate the ruin probability in risk processes with the adoption of reinsurance contracts (quota share and excess of loss), compared to scenarios without such treaties. Methods: the Cramér-Lundberg process was simulated using the Monte Carlo method, adjusting several probabilistic distributions to the severity of the compound Poisson process, which is calibrated with a set of 3,917,863 real microdata, from 30 insurance lines of business. Results: it was found that, although each branch presents particularities in the claim severity, the correct choice of reinsurance (proportional or not) implies the reduction of the ruin probability for a fixed solvency capital. Conclusion: the appropriate choice of the reinsurance contract, especially when there is evidence of high kurtosis in the claim values, intensifies the exponential decline in the relationship between the solvency capital and the ruin probability.

Resseguro e Capital de Solvência: Atenuantes da Probabilidade de Ruína de Seguradoras

ABSTRACT Context: insurance companies are important to society, since they guarantee financial protection to individuals from property losses, in addition to fostering the capital market through the allocation of guarantee assets. Thus, it is essential to evaluate the instruments that guarantee their long-term financial solvency. Among them are the adoption of reinsurance treaties, the sizing of the solvency capital, and the actuarial modeling of risk processes, which allow the measurement of the ruin probability. Objective: estimate the ruin probability in risk processes with the adoption of reinsurance contracts (quota share and excess of loss), compared to scenarios without such treaties. Methods: the Cramér-Lundberg process was simulated using the Monte Carlo method, adjusting several probabilistic distributions to the severity of the compound Poisson process, which is calibrated with a set of 3,917,863 real microdata, from 30 insurance lines of business. Results: it was found that, although each branch presents particularities in the claim severity, the correct choice of reinsurance (proportional or not) implies the reduction of the ruin probability for a fixed solvency capital. Conclusion: the appropriate choice of the reinsurance contract, especially when there is evidence of high kurtosis in the claim values, intensifies the exponential decline in the relationship between the solvency capital and the ruin probability.

Modern treatment of patients with arterial hypertension and chronic coronary syndrome

Approximately 1,2 billion people worldwide suffer from arterial hypertension. Among these patients, less than half receive effective treatment. Poor blood pressure control contributes to the development of complications such as stroke or coronary artery disease. A patient with such complications automatically becomes a patient at very high cardiovascular risk, and thus requires personalized and effective treatment, not only of hypertension, but also of its complications. Despite the advancement of the disease, lifestyle modification and correct choice of pharmacotherapy can protect the patient from developing heart failure and prevent acute cardiovascular events.

Choosing a methodological base for forming and accounting for the construction costs of a gas well at the final stage of field development

The article introduces the problems of choosing a methodological base for forming and accounting costs during well construction, taking into account the intensification of gas inflow at the final stage of field development. The main methods that allow taking into account the costs of drilling operations are outlined. The main costs that need to be taken into account when designing fields with hard-to-recover gas reserves are identified and characterized. The main stages of cost formation by construction phases of a gas-producing well are shown, as well as the factors influencing the level and structure of the cost price during the construction of a well are highlighted. The authors consider the classification of cost accounting methods in the context of the comparison criterion and present the possible results of the correct choice of the cost formation method during the construction of a gas well at the final stage of its development.

Substantiation of the perspectivity of improving of the population informing about the criteria of the correct choice of modern multivitamin drugs

The aim. Determination of the need to raise awareness of the population about multivitamins and the criteria for their rational choice. Materials and research methods. To achieve the goal of the study, it was necessary to develop a questionnaire for visitors to pharmacies and carry out an anonymous survey of them. All adult visitors of the pharmacy were attracted to the survey. The developed questionnaire consisted of 3 parts and contained 32 questions processed in the course of our own research. Research results. Among the pharmacy visitors we surveyed, the majority were between the ages of 35–55, approximately equally divided were men and women who mainly lived in the Kiev region (87 %), were not students and did not have educational levels of bachelor or master, and had no relation in health care education. Summarizing the information obtained in the course of processing questionnaires with the answers of visitors to pharmacies, it can be noted that in the surveyed group of respondents there is a certain interest and indifference to the discussed aspects, but quite often there is a lack of knowledge in this regard. Conclusions. In the course of analyzing the results of the questionnaire survey, the level of awareness of the population regarding general information about the pharmacology of multivitamin drugs and the criteria for their correct choice was determined. From the data obtained, it can be concluded that on many issues the respondents showed an insufficient level of knowledge, which justifies the need for additional information about multivitamins, and indicates that better it should be done with participation of a specialist with a pharmaceutical education or physician. Mostly the population lacks knowledge on the issues listed in the second part of the questionnaire, namely, on general information about the biological and pharmacological properties of vitamins. It was found that the information obtained from the Internet or other media, including advertising, has a significant impact on the awareness and decision of the respondents

A risk-based approach to solving the problem of airline schedule operational management

The paper discusses the problem of optimal regulation of aircraft assignments for airline flights. Due to the fact that the activities of the airline are subject to changes caused by both external and internal environment, the planned schedule needs continuous management and control. In the event when the actual flight schedule deviates from the planned one, it is necessary to promptly make a decision on adjusting (restoring) the schedule and reassigning aircraft. Operational schedule management involves making adjustments to the current schedule from a depth of several hours to several days. The solution to the problem is to determine the unambiguous correspondence of flights and specific aircraft subject to maximizing the likelihood of meeting production targets and observing a number of restrictions. The task of managing airline schedules belongs to the class of scheduling optimization problems for parallel-sequential systems studied within the scheduling theory. It is NP-hard and requires the development of computationally efficient solution algorithms. However, the issue of choosing criteria for the optimization problem deserves special attention, since the correct choice plays an essential role in terms of assessing the effectiveness of decision-making. In the theory of decision-making, no general method for choosing the optimality criteria has been found. The definition of the target criterion depends on the expectations of the production. Within the framework of this paper, an original criterion is proposed for constructing an optimal solution to the discrete problem of managing aircraft assignments, the main idea of which is to find a balance between the duration of the schedule and the number of flights with a negative deviation from the planned schedule by assessing the level of punctuality violation risk. The paper gives a detailed concept of punctuality, describes an approach to assessing the level of risk, and also proposes an original formal formulation of the task of operational management of aircraft assignments based on the criterion of minimizing the risk of violation of flight punctuality.

Formation features of the parameters of the model winter bread wheat variety of intensive type for the conditions of the Rostov region

Breeding success is determined by the correct choice of agro-ecotype. In this regard, we have carried out a comprehensive estimation of 75 winter bread wheat varieties and samples of the competitive trials. The variety ‘Ermak’ was used as a standard. The study was carried out using the material and technical base of the Federal State Budgetary Scientific Institution Agricultural Research Center “Donskoy” (FSBSI “ARC “Donskoy”) in 2017–2019. The purpose was to study the correlation among economically valuable traits of winter bread wheat varieties and samples and to find genotypes similar in their parameters to the model variety based on curvilinear regressions. As a result of the phenotypic estimation of the quantitative traits of winter bread wheat varieties and samples, there was determined an average level and their variability degree. Their productivity ranged from 8.52 to 10.51 t/ha. Through the years of study, the variation coefficients indicated a high stability of these features (from 0.9 to 10.0%). In order to identify the similarities and differences between varieties and samples, there has been conducted a cluster analysis. As a result of this analysis, there has been selected the winter bread wheat variety ‘Yubiley Dona’ (C25), parameters which were more identical to the model (C76). This variety is recommended for further breeding process to improve the studied basic economic traits.

Analysis of the terms of usage of non-removable restorations fixed by different glass ionomer cements

Preservation and restoration of dental health of patients is achieved by early detection and treatment of diseases, finding ways of individual prevention, detection and elimination of risk factors for their development. The amount of materials significantly increased used to restore the integrity of teeth and dentition. Among them are dental materials for permanent fixation of indirect non-removable restorations. The material is used to fill the space between the inner surface of the artificial structure and the support element. This helps to mechanically fix the restoration in place to prevent its displacement during chewing. The correct choice of dental material for permanent fixation is an important decision and will determine the long-term success of permanent restorations. The aim of the study is to analyze the durability using non-removable structures of dentures mounted on different glass ionomer cements.