STARec: Adaptive Learning with Spatiotemporal and Activity Influence for POI Recommendation

POI recommendation has become an essential means to help people discover attractive places. Intuitively, activities have an important impact on users’ decision-making, because users select POIs to attend corresponding activities. However, many existing studies ignore the social motivation of user behaviors and regard all check-ins as influenced only by individual user interests. As a result, they cannot model user preferences accurately, which degrades recommendation effectiveness. In this article, from the perspective of activities, this study proposes a probabilistic generative model called STARec. Specifically, based on the social effect of activities, STARec defines users’ social preferences as distinct from their individual interests and combines these with individual user activity interests to effectively depict user preferences. Moreover, the inconsistency between users’ social preferences and their decisions is modeled. An activity frequency feature is introduced to acquire accurate user social preferences because of close correlation between these and the key impact factor of corresponding check-ins. An alias sampling-based training method was used to accelerate training. Extensive experiments were conducted on two real-world datasets. Experimental results demonstrated that the proposed STARec model achieves superior performance in terms of high recommendation accuracy, robustness to data sparsity, effectiveness in handling cold-start problems, efficiency, and interpretability.

Association Among Spinnbarkeit, Electrical Conductivity, and Crystallization of Cervical Mucus and Pregnancy Rate in Egyptian Baladi Cows

Alteration of the biophysical and biochemical characteristics of cervical mucus (CM) due to differences in steroid hormones through the estrus cycle leads to different pregnancy rates. This investigation aims to study the possible relationship between CM properties with biochemical profiles, macro-mineral levels, and steroid hormones concentrations, and their effects on pregnancy rates of Egyptian cows. Fourteen Baladi cows were used and synchronized. The model log-likelihood ratio was highly significant (P=0.0009), and reported that the spinnbarkeit (SPK), electrical conductivity (EC), and crystallization (CRS) had significant effect on high pregnancy rate. The 3rd level of SPK (>13.5 cm) and EC (>15 mS/cm) was the highest significant (P=0.0016 & 0.0517, respectively) and a clear positive of estimate marginal effect (20.2543 & 10.6192, respectively) attitude towards the pregnancy rate. However, in case of the CRS, the significant effect was in the first two levels (P=0.0321 & 0.0425, respectively) with a high pregnancy rate, reverse the last 2 levels. Total protein, cholesterol, glucose, potassium, chloride levels, and estradiol concentrations were observed higher with increasing levels of SPK and EC and appearance of typical fern patterns (first two levels of CRS), in contrast to sodium, and progesterone concentrations that decreased with elevating levels of SPK and EC and appearance of atypical fern patterns (last two levels of CRS). There was a close correlation between CM properties and steroid hormones (P4 & E2). So, alterations in CM properties, especially SPK, EC, and CRS, can be utilized to foresee estrus time and, as a result, insemination time.

Dependence of cardiovascular diseases mortality on helioseismic indicators in the Sheki region of the Azerbaijan Republic

Aim. To study the dependence of cardiovascular diseases mortality on geophysical and seismic indicators in the Sheki region of the Azerbaijan Republic.Material and methods. In 2013, seismological information was obtained from 35 telemetry stations, which included a review of the seismic setting of the republic, the distribution of seismic waves, the dynamics of seismic processes, the intensity of earthquakes, magnitude, etc. Based on the spatial distribution of the focal zones identifi ed by weak seismicity and the magnitudes of the maximum possible earthquakes in them, a map of the seismic hazard of the territory of Azerbaijan was compiled. To analyze the connection with diseases in the Sheki region, 742 case histories of patients (48.8% — 362 men and 51.2% — 380 women) who died in 2013 from various diseases, were analyzed.Results and discussion. Statistically signifi cant (p < 0.001), more deaths among men were from acute coronary syndrome (63.3%), from acute heart failure (46.0%) and from hypertensive crisis (HС) (45.3%). 59.3% died from acute cerebrovascular accident, 54.7% died from a hypertensive crisis and 54,0% from acute heart failure among women. Statistically signifi cant number of deaths was in the age range of 70–79 years old and 80–89 years old.The largest number of deaths was at a depth of 11–20 km — 20.6%, 21–30 km — 16.7%, less than 10 km — 10.5%. When the depth of the process was less than 10 km, the largest percentage of mortality was from acute coronary syndrome — 24.4%, with the depth of 11–20 km — from hypertensive process (40.5%); 24.2% died from heart failure.Conclusion. Thus, there is a close correlation between geomagnetic changes and CVD mortality in Sheki region of Azerbaijan. It is realized in the form of an increase in the frequency of cases and deaths, and the number of these cases is highly dependent on patients’ age.

OPTICAL SYSTEM DESIGN OF THE DETECTOR FOR SOLAR TERAHERTZ EMISSION MEASUREMENTS

The objectives and scientific tasks of the planned space experiment “Solntse-Terahertz” to be performed onboard the ISS Russian Segment are briefly described in the paper. In particular, the aim of the experiment is to study uninvestigated solar electromagnetic emission in the terahertz domain, in ~ 1012 – 1013 Hz (300-30 µm) frequency range. It is expected to obtain new data on solar active region emission including solar flare emission. These data are necessary to clarify the nature of solar activity and construct physical model of charged particle acceleration in active regions during solar flares and other astrophysical objects. We focus on the telescope optical system design and evaluation of main characteristics of this system. Results of simulations and comparison with the experimental verification of obtained characteristics are presented. A close correlation of the estimations and experimental results was obtained. As a result, main parameters of the telescope optical system of experimental hardware “Solntse-Terahertz” were determined. Key words: Sun, solar flares, terahertz emission, optical system.

Increasing photosynthetic productivity of cereal bioenergy crops as affected by the water content in leaves under mycorrhization of the root system

Purpose. To determine photosynthetic productivity of miscanthus gigantheus and switchgrass as affected by leaf water content under mycorrhization of their roots. Methods. Field, laboratory, and statistical. Results. The obtained results indicate that the use of vesicular-arbuscular mycorrhizal (VAM) preparations Mycofriend (fungus Trichoderma harzianum RIFAI.), Mikovital (fungus Tuber melanosporum VITTAD.), and nitrogen-fixing preparation Florobacillin (Bacillus subtilis Cohn.) helps to increase water content in the leaves of such cereal bioenergy crops as miscanthus gigantheus and switchgrass. In particular, in all vegetation periods, in the treatments with Mycofriend, the water content in miscanthus gigantheus leaves was higher by 11.2–20.1% than in the control, while in switchgrass it was higher by 16.9–20.5% than in the control. In the treatments with Mikovital and Florobacillin, leaf water content ranged in miscanthus from 7.1 to 15.6% and from 5.8 to 11.7%, respectively, and in switchgrass, from 11.6 to 14.7% and from 7.0 to 10.2%, respectively. The photosynthetic productivity of these crops is affected by the water content in the leaves. There is a close correlation between these factors (correlation coefficient 0.95–0.96). Conclusions. Root application of biological plant products Mycofriend, Mikovital and Florobacillin improves water content in the leaves of cereal bioenergy crops, such as miscanthus gigantheus and switchgrass, and increases their photosynthetic productivity.

The Italian School at the Time of COVID-19—Implications for Students at the Personal and Didactic Level

The author takes up the problem of education in Italy in the time of COVID-19. The objective of this article is to understand the impact of COVID-19 on the progress of school and the lives of children and adolescents. To pursue this cognitive objective, the author conducted an analysis of the relevant literature published between February 2020 and January 2021, mainly in Italian. The author has also formulated three research questions that will help investigate the above problem. The article is written with the help of the analytical method and takes into consideration the literature on the subject dedicated to children and adolescents. The analysis of the literature allowed the author to formulate final conclusions, which were developed in close correlation with the accepted research questions.

Visual Function and Visual Perception among Senior Citizens with Mild Cognitive Impairment in Taiwan

Purpose: With the benefits of advanced medical technology, Taiwan has gradually changed from an aged society to a super-aged society. According to previous studies, the prevalence rate of mild cognitive impairment (MCI) over the age of 60 is 15% to 20%. Therefore, the main purpose of our study was to analyze the correlation of cognitive function with visual function (specifically, binocular vision and visual perception) in Taiwanese volunteers aged 60 years or older. Methods: Thirty-six healthy participants who were not taking psychiatric medications and who had not been diagnosed with any retinal or optic nerve diseases were enrolled. Addenbrooke’s cognitive examination III (ACE-III), binocular visual function, and visual perception evaluation were performed, and the data analyzed statistically by t-test, χ2, linear regression, and MANOVA. Results: Cognitive function was closely correlated with visual function and visual perception; the horizontal adjustment time of binocular eye movement, stereopsis, the motor-free visual perception test-4 (MVPT-4), and peripheral awareness actually displayed higher explanatory power in predicting cognitive function. In addition, various interactive parameters between visual function and visual perception were found to affect specific aspects of ACE-III. Discussion: Our study revealed that there was a close correlation of cognitive function with visual function; as such, it may be possible to predict visual function deficits in patients with mild cognitive impairment.

Studying auroral activity using the SME index at the magnetic storm main phase during CIR and ICME events

In this paper, we examine the relationship of the SME index with magnetic storm characteristics and interplanetary medium parameters during the main phase of magnetic storms caused by CIR and ICME events. Over the period 1990–2017, 107 magnetic storms driven by (64) CIR and (43) ICME events have been selected. In contrast to AE and Kp, a stronger correlation is shown to exist between the average SME index (SMEaver) and interplanetary medium parameters during the magnetic storm main phase. Close correlation coefficients between SMEaver and the SW electric field (southward IMF Bz) have been obtained for CIR and ICME events. SMEaver has been found to increase with the rate of magnetic storm development and |Dstmin|. For CIR and ICME events, no difference has been revealed between SMEaver and |Dstmin| in linear regression equations.

Studying auroral activity using the SME index at the magnetic storm main phase during CIR and ICME events

. In this paper, we examine the relationship of the SME index with magnetic storm characteristics and interplanetary medium parameters during the main phase of magnetic storms caused by CIR and ICME events. Over the period 1990–2017, 107 magnetic storms driven by (64) CIR and (43) ICME events have been selected. In contrast to AE and Kp, a stronger correlation is shown to exist between the average SME index (SMEaver) and interplanetary medium parameters during the magnetic storm main phase. Close correlation coefficients between SMEaver and the SW electric field (southward IMF Bz) have been obtained for CIR and ICME events. SMEaver has been found to increase with the rate of magnetic storm development and |Dstmin|. For CIR and ICME events, no difference has been revealed between SMEaver and |Dstmin| in linear regression equations.

Oddziaływanie nieliberalnych rządów Nicolasa Maduro w Wenezueli na bez-pieczeństwo międzynarodowe w perspektywie współpracy Moskwy i Caracas

The aim of the paper is to show how the peculiarities of the Venezuelan political system, expressed by Nicolas Maduro and implemented by forces concentrated around this person, affect in-ternational security. The article shows that there is a close correlation between the illiberal political system of contemporary Venezuela and the behavior of the authorities of this country on the interna-tional forum. The degree of military involvement of the Russian Federation in Venezuela was as-sessed. It has been shown that the political system of contemporary Venezuela is petrified by the features of the authoritarian system; thus these features become the source of its weakness. This, in turn, enables countries supporting Maduro's rule to strengthen their positions in this country, which Russia also benefits from. Russia benefits, however, from this situation with a visible reserve resulting from the awareness of the total economic inertia of this, nominally, one of Latin America's richest countries. It was emphasized that Moscow is increasingly taking a wait-and-see position towards Ca-racas, realizing the growing uncertainty about the investments made so far in the country.