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As the most important quality parameters of the hops the development of mathematical models for predicting of alpha-acids accumulation in hop cones is very important for planning of hop stocks in order to avoid the market stress. The aim of this study is to verify the accuracy of the empiric mathematical model for predicting the content of alpha-acids in hop cones of cv. Aurora using the linear regression, general linear regression and Cobb-Douglas production model-function. The values of standard deviations (σ) of differences between predicted and analyzed content of alpha-acids for used methods are much lower in the comparison with the empiric mathematical model of alpha-acids prediction in the case of non-compliance with the strictly set condition for reliability of the empirical mathematical model, according to which the daily reference crop evapotranspiration (ET0) in July  4.5.

Cerebral blood flow autoregulation protects brain tissue from blood pressure variations and maintains cerebral perfusion pressure by changes in vascular resistance. High salt (HS) diet impairs endothelium-dependent vasodilation in many vascular beds, including cerebral microcirculation, and may affect vascular resistance. The aim of present study was to determine if 7-day HS diet affected the reactivity of middle cerebral artery (MCA) to orthostatic challenge in healthy human individuals, and if autoregulatory mechanisms and sympathetic neural regulation were involved in this phenomenon. Twenty-seven persons participated in study (F:21, M:6, age range 19–24). Participants consumed 7-day low-salt (LS) diet (< 2.3 g kitchen salt/day) and afterwards 7-day HS diet (> 11.2 g kitchen salt/day). Blood and urine analysis and anthropometric measurements were performed after each diet. Arterial blood pressure, heart rate and heart rate variability, and cerebral and systemic hemodynamic parameters were recorded simultaneously with transcranial Doppler ultrasound and The Task Force® Monitor in response to orthostatic test. Participants remained normotensive during HS diet. Following both, the LS and HS dietary protocols, mean cerebral blood flow (CBF), as well as the velocity time integral and diastolic blood pressure decreased, and cerebral pulsatility index increased after rising up. Importantly, cerebrovascular resistance significantly increased in response to orthostasis only after HS diet. Urine concentration of noradrenaline and vanillylmandelic acid, baroreflex sensitivity (BRS), and sympathetic neural control was significantly decreased in HS diet. Results suggest that CBF in response to orthostatic test was preserved in HS condition due to altered vascular reactivity of MCA, with increased cerebrovascular resistance and blunted BRS and sympathetic activity.

The worldwide spread of the SARS-CoV 2 virus infection challenged and continues to challenge societies and individuals. The isolation and social distancing create psychosomatic stress on individuals, on families, and on relationships. The foreign students that are studying at the I. Horbachevsky Ternopil National Medical University (TNMU) could not travel home due to the COVID-19 lock down. Our goal was to investigate the sex difference in chronic stress during the COVID-19 lock down. In this part of the study, we are building a Mathematical Model (MATEM) of saliva cortisol data.

In this paper, we propose an efficient method for searching for a globally optimal k- partition of the set A ⊂ R n. Due to the property of the DIRECT global optimization algorithm to usually quickly arrive close to a point of global minimum, after which it slowly attains the desired accuracy, the proposed method uses the well-known k-means algorithm with a initial approximation chosen on the basis of only a few iterations of the DIRECT algorithm. In case of searching for an optimal k-partition of spherical clusters, the method is not worse than other known methods, but in case of solving the multiple circle detection problem, the proposed method shows remarkable superiority.

Energija Sunca kao obnovljivi izvor energije (OIE) može povećati energetsku održivost sustava te poboljšati sigurnost dostave energije na način da smanjuje ovisnost o uvozu energije i energetskih sirovina. Bolje iskorištavanje OIE doprinosi produženju trajanja rezervi primarnih energetskih izvora. Rad se bavi obradom i prikazom podataka raspoložive Sunčeve energije koju možemo iskoristiti kao dodatni energent. Obrada i prikaz prikupljenih podataka može se izvršiti na više načina. Podaci u članku su prikazani tablično, a zbog specifičnosti cikličnog ponavljanja klimatskih uvjeta i prikaza podataka su prikazani i pomoću Burnovog dijagrama.