Ekologiya cheloveka (Human Ecology)

The electrocardiographic examination of 38 male skiers, natives of the European North aged from 18 to 22 years was carried out during four seasons (September, January, March, July). We have found that the highest myocardial electrical activity was typical for the winter period. Seasonal changes in the electrical activity of the myocardium developed mostly in the interventricular septum and the basal parts of the heart, and the right heart compared with its left part.

The present research has described mutual influence of personality accentuations specific to certain students and failures in psychical adaptation to university conditions. According to the system approach to adaptation, which includes a psychological, socio-psychological, physiological components, we have studied the following aspects in the students with different accentuations: a level of psychic adaptation, social satisfaction, somatic health indicators, indicators of academic achievements. It has been established that the personalities with different accentuations were characterized by disorders of different components of the adaptation system. We have identified risk groups of adaptation among the students with personality accentuations. Types of accentuations with favorable prognosis of adaptation to university conditions have also been detected.

Background. Thrombolytic therapy (TLT) remains the most effective method for revascularization in acute ischemic stroke (AIS). The aim of our research was to evaluate the efficacy and safety of reperfusion therapy in intravenous TLT in the AIS. Methods. We have analyzed retrospectively medical records of 95 patients with AIS subjected to intravenous TLT with recombinant tissue plasminogen activator (rtPA) within the first 4.5 hours after emergence of symptoms (“therapeutic window”). The average dose of intravenous rtPA was 0.9 mg/kg. All the patients were divided into subgroups according to severity of AIS and age in accordance with WHO criteria. Following the TLT, we evaluated dynamic changes of neurological deficits using the National Institute Health Stroke Scale (NIHSS), rehabilitation levels using the modified Rankin Scale (mRs), as well as incidence of ischemic lesions and hemorrhagic transformation (HT) using CT-scan. Results and Conclusions: We have found that intravenous TLT was beneficial in the subgroups of the patients younger than 60 years, as well as those scored of moderate AIS severity (NIHSS < 14 points). Despite the use of the TLT, disability severity (mRs 4-5 points) increased from 14 to 50 % in parallel with increasing age and severity of the brain damage. The incidence of symptomatic HT following the intravenous TLT corresponded to the international studies results.

In this paper we present theoretical principles of the use of one- and two-samples Student’s t-tests. Practical examples are presented with detailed explanations of the use of formulas as well as with step-by-step algorithm on how to use STATA software for comparisons of means in one- and two independent samples with subsequent interpretation of the outputs.