Directions and Extent of Flows Changes in Warta River Basin (Poland) in the Context of the Efficiency of Run-of-River Hydropower Plants and the Perspectives for Their Future Development

This paper presents changes in the flow of 14 rivers located in the Warta River basin, recorded from 1951 to 2020. The Warta is the third-longest river in Poland. Unfortunately, the Warta River catchment area is one of the most water-scarce regions. It hosts about 150 hydropower plants with a capacity of up to 5 kW. The catchment areas of the 14 smaller rivers selected for the study differ in location, size, land cover structure and geological structure. The paper is the first study of this type with respect to both the number of analyzed catchments, the length of the sampling series and the number of analyzed flow characteristics in this part of Europe. The analysis of changes in the river flows was performed with reference to low minimum, mean and maximum monthly, seasonal and annual flows. Particular attention was paid to 1, 3, 7, 30 and 90-day low flows and durations of the flows between Q50 and Q90%. In addition, the duration of flows between Q50 and Q90% were analysed. Analysis of the direction and extent of particular flow types was performed by multitemporal analysis using the Mann–Kendall (MK) and Sen (S) tests. The analysis of multiannual flow sequences from the years 1951–2020 showed that the changes varied over the time periods and catchments. The most significant changes occurred in the low flows, while the least significant changes occurred in the high flows. From the point of view of the operation of the hydropower sector, these changes may be unfavourable and result in a reduction in the efficiency of run-of-river hydropower plants. It was established that local factors play a dominant role in the shaping of river flows in both positive and negative terms, for the efficiency of the hydropower plants.

Craniological sources on the problem of ethnogenesis of the Narym Selkups

The Narym Selkups are an indigenous population of the Middle Ob River region speaking various dialects of the Selkup language related to the South-Samodian branch of the Ural language family. In the course of the study of Medieval and relatively recent burial grounds in the territory of the Narym Ob area of Tomsk Oblast, considerable amount of craniological material has been collected, which constitutes an important historical source for solving general problems of their origins. According to the archaeological and ethnographic materials, the Medieval burials were left by direct ascendants of modern Narym Selkups, whereas the materials from the later burial grounds are directly associated with their specific local-dialect groups. This paper is aimed to introduce into scien-tific discourse virtually all craniological materials known today from the burial grounds left by the Narym Selkups, and, on the basis of the results of group cross-correlation, to identify trends of the territorial variability of the whole community. Significant increase of new finds from the vast territory of the Middle Ob region, population-driven approach to the data analysis and development of the craniometric technique warranted re-grouping of the finds by the territorial principle and their repeated measurement and analysis. In view of the current problem, all cranio-logical materials were grouped into ten sampling series, five of which are published for the first time (the burial ground of Ostyatskaya Gora and four combined craniological series from the burial grounds of Lower Chulym, Narym Ob, Upper Ket, and the Tym and Vasyugan rivers). Analysis of the variability of the series from the Narym Ob region in chronological and geographical bands showed their weak variability in space and time. Therefore, prior to the Russian colonization of Siberia, this region of the Middle Ob area was not invaded by considerably large groups of people of different anthropological appearance. All studied craniological series were samples from the single unity. Although the territorial variability of the anthropological features within the groups of the Narym Selkups is not large, in some cases an influence of territorially closest neighbours on the anthropological structures of particular Selkup populations can be discerned. It appeared that the southern groups exhibit resemblance with their territorially closest Turkic populations of the Chulym and Lower Tom regions, while in the composition of other Narym groups, there have been identified an admixture of the component genetically related to the Turkic populations of the Western-Siberian forest-steppe — Barabino and Tobol-Irtysh Tatars, and, although being very weak, an influence of the Ob Ugric populations can be discerned.

Approximation properties of multivariate exponential sampling series

In this paper, we generalize the family of exponential sampling series for functions of $n$ variables and study their pointwise and uniform convergence as well as the rate of convergence for the functions belonging to space of $\log$-uniformly continuous functions. Furthermore, we state and prove the generalized Mellin-Taylor's expansion of multivariate functions. Using this expansion we establish pointwise asymptotic behaviour of the series by means of Voronovskaja type theorem.

A solution for global hygienic challenges regarding the application of heater-cooler systems in cardiac surgery

71.759 surgical procedures were performed in 2019 with the aid of cardiopulmonary bypass in Germany. To adjust the patient’s body temperature on extracorporeal circulation, the application of a heater-cooler unit (HCU) is mandatory. However, in case of insufficient sanitisation of HCU, life-threatening infections can be transmitted by the device to the patients, including Legionella bacteria, Mycobacterium chimaera, Pseudomonas aeruginosa. To avoid disease transmission, as a requirement for safe medical practice established by regulatory authorities, HCUs must be regularly disinfected by hazardous chemicals posing a danger for both handling humans and the environment. Therefore, to comply with regulations, HCU manufacturers have introduced both timely and financially extensive sanitisation procedures. Our paper describes a novel, effective and easy to handle disinfection method for the above problematics without utilising hazardous chemicals. The method’s technical principle is electrolysis, resulting in drinking water quality regarding the analysed germs in the worldwide most commonly utilised heater-cooler device. The main aim of the study was to prove the efficacy and reliability of the device cleansing process. Furthermore, the economic impact of the novel method was evaluated. Therefore, we have undertaken 60 microbiological sampling series between December 2019 and November 2020 from a conventional HCU (3T LivaNova, Germany). During the total investigational period, no contamination with Pseudomonas aeruginosa or Legionellae could have been demonstrated in the HCU. The extreme slow-growing nontuberculous M. chimaera was detected only in one sample obtained from diamond electrode cleansed HCU water, and source of contamination was promptly eliminated by a simple technical modification of the device test-site. Additionally, the diamond electrode application is beneficial for eliminating potentially hazardous cleansing material from the process, which may affect otherwise both patients operated on cardiopulmonary bypass and the perfusionists.

After the Fall: The Demographic Destiny of a Gorgonian Population Stricken by Catastrophic Mortality

In recent years, the frequency of mass mortality events in marine ecosystems has increased, and several populations of benthic organism have been affected, reducing their density and changing their size and age structure. Few details are known about the dynamics of these populations over long time intervals. In late summer of both 1999 and 2003 two drastic mass mortality events, co-occurring with anomalous temperature increases, affected the northwestern Mediterranean rocky coastal communities. Due to these events the Paramuricea clavata population living at the western edge of La Spezia Gulf (Italy) was stricken, and 78% of the colonies died. This population was monitored from 1998 (pre-mortality) until 2013. This paper deals with the photographic sampling of permanent plots carried out in 2013. The findings were compared with those from the previous sampling series. This long-term, non-destructive sampling highlights the demographic trajectory of the octocoral population there after two anomalous mortality events, indicating that some new drop-point between local extinction and complete recovery may be have been reached. Long-term monitoring (including pre-mortality data) could allow evaluating the effects of global climate change on the conservation of impacted populations.

Approximation by pseudo-linear discrete operators

<p style='text-indent:20px;'>In this note, we construct a pseudo-linear kind discrete operator based on the continuous and nondecreasing generator function. Then, we obtain an approximation to uniformly continuous functions through this new operator. Furthermore, we calculate the error estimation of this approach with a modulus of continuity based on a generator function. The obtained results are supported by visualizing with an explicit example. Finally, we investigate the relation between discrete operators and generalized sampling series.</p>

Boundedness properties of semi-discrete sampling operators in Mellin–Lebesgue spaces

<p style='text-indent:20px;'>In this paper we study boundedness properties of certain semi-discrete sampling series in Mellin–Lebesgue spaces. Also we examine some examples which illustrate the theory developed. These results pave the way to the norm-convergence of these operators</p>