The explosive rise of wireless services necessitates a network connection with high bandwidth, high performance, low mistakes, and adequate channel capacity. Individual mobile users, as well as residential and business clusters are increasingly using the internet and multimedia services, resulting in massive increases in the internet traffic demand. Over the past decade, internet traffic has grown significantly faster than Moore’s law predicted. The current system is facing significant radio frequency spectrum congestion and is unable to successfully transmit growing amounts of (available) data to end users while keeping acceptable delay values in mind. Free space optics is a viable alternative to the current radio frequency technology. This technology has a few advantages, including fast data speeds, unrestricted bandwidth, and excellent security. Since free space optics is invisible to traffic type and data protocol, it may be quickly reliably and profitably integrated into an existing access network. Despite the undeniable benefits of free space optics technology under excellent channel conditions and its wide range of applications, its broad use is hampered by its low link dependability, especially over long distances, caused by atmospheric turbulence-induced decay and weather sensitivity. The best plausible solution is to establish a secondary channel link in the GHz frequency range that works in tandem with the primary free space optics link. A hybrid system that combines free space optics and millimeter wave technologies in this research is presented. The combined system offers a definitive backhaul maintenance, by drastically improving the link range and service availability.

Contemporary approaches to Poland’s Western and Northern Territories revolve around the concept of “postmigration communities”, or more broadly —“postmigration”, understood as a significant feature (or set of features) of community and social phenomena. These terms are present not only in academic discourse, but also in discussions on local identity. They are also an essential element of their symbolic status. Based on field research in the Głowczyce commune in Pomerania, the author tackles the issue of inhabitants’ attitudes towards breaking the historical and cultural continuity and the formation of the community from scratch, as well as the role of postmigration in shaping the symbolic status of the place. The article shows the capacity of the term “postmigration”. In residents’ statements, postmigration appears unnamed, as a problem, a challenge, and an asset. Attitudes towards postmigration reveal diverse attempts to cope with the break in historical and cultural continuity, which turns out to still be a significant element of identity processes taking place in the community in question.

The investigations conducted in 1994 and 1996 concerned aphids infesting fields and neighbouring semi-natural habitats – midfield thickets with trees and the vegetation growing on the ditch margins. Aphids were caught into Moericke traps placed at the plant level. The material collected was studied to determine aphid number, dominance of individual species, similarity of dominance structure of aphid communities (Renkonen Index) and diversity of aphid communities (Shannon-Weaver Index). Aphids were collected in the field and in the natural habitats neighbouring the field. In both years black bean aphid (Aphis fabae Scop.) was either the dominant or sub-dominant species in every habitat studied. A relative species diversity of aphids occurring in semi-natural habitats was significantly highe rthan that in the adjacent field. The results of these investigations indicate that the crop affects aphid fauna flying onto neighbouring midfield thickets.

Phytosociological research was carried out in the town of Kłobuck, Silesian voivodeship. During the years 1998 and 1999 35 releves were taken using Braun-Blanquet method. In the study area 14 plant herb communities were distinguished, 10 of which were classified as associations. These are: community with Lenina minor, Nupharo-Nymphaeetum albae, Sparganietum erecti, Phragmitetum australis, Typhetum latifoliae, Glycerietum maximae, Phalaridetum arundinaceae, community with Jasione mon/ana, community with Deschampsia caespitosa, community with Holcus lana/us, Filipendulo-Geranietum, Scirpetum silvatici, Epilobio-Juncetum effusi, Arrhenatheretum eleatioris.

The subject of investigations was the fragment of low peatland complex located close to Miękinia,

about 30 km from Wrocław. Within the range of the examined area of peat bog complex there can be distinguished three parts differing in their utilization and composition of species, namely: 1/ the area degraded by the

attempt to afforest it with alder trees Alnus glutinosa (L.) Gaertner, 2/ occasionally used bog hay meadow and

3/ typical peat forming phytocenosis. Total number of determined species, belonging to 11 phytosociological

classes, ranged 77, out of which more than a half constitute representatives of Molinio-Arrhenatheretea class.

As far as a non-afforested area was concerned, there were determined 5 phytocenosis, including 4 classified as

peat forming ones and one typical for post-bog meadows (Alopecuretum pratensis). The afforested area featured

herbaceous plant composition which indicated that the area with Alopecuretum pratensis phytocenosis had been

degraded. Analysis of environmental requirements, done with the use of ecological numbers, proved that prevailing number of species characterize similar requirements. It was mainly afforested part to feature taxons of

broader ecological scale, e.g. Polygonum bistora L., Carex hirta L. and Plantago lanceolata L.

The afforested area was purchased by a private person, therefore it can be assumed that the reason for such

a way of peatlands utilization was obtaining EU subsidies at minimum work effort. A higher financial profit,

however, would have been made by the owner if he had maintained a bog area as an extensive meadow.

This review covers aspects of soil science and soil biology of Antarctica with special focus on King George Island, South Shetlands, the martitime Antarctic. New approaches in soil descriptions and soil taxonomy show a great variety of soil types, related to different parent material, mainly volcanic origin, as well as on influences by soil biological processes. The spread of higher rooting plants attract microorga nisms, nematodes and collemboles which in turn build new organic material and change the environment for further successors. Microbial communities are drivers with respect to metabolic and physiological properties indicating a great potential in a changing environment. The literature review also shows a lack of investigations on processes of carbon and nitrogen turnover, despite wide knowledge on its standing stock in different environments. Further , only few reports were found on the processes of humification. Only few data are available which can be regarded as long term monitorings, hence, such projects need to be established in order to follow ecological changes.

Eleven species of cumaceans were found in 105 samples collected in Admiralty Bay (King George Island) in the summers of 1984/85 and 1985/86, from 20 to 500 m depth range. Four cumacean assemblages were distinguished using the multivariate analysis. They were characterized by the dominance of one or two species often with low density values. Two assemblages were found in open waters of Admiralty Bay. The first inhabited on sandy−clay−silt and silty−clay−sand bottom deposits in the depth range from 140 to 330 m, with Campylaspis maculata (1.6 ± 2.1 ind./0.1m 2 ; F = 72.4%) and Leucon sp. (1.4 ± 1.6 ind./0.1m 2 ; F = 68.9%) as key species. The second assemblage was found in the depth range from 50 to 120 m with silty−sand sediments, and it was characterized by the presence of Vauthompsonia inermis (6.5 ± 6.6 ind./0.1m 2 ; F = 92.0%). A third assemblage was found in shallow waters influenced by glaciers in the bottom area of Ezcurra Inlet. It was characterized by sandy−clay−silt sediments and the presence of Eudorella splendida (14.6 ± 9.4 ind./0.1m 2 ; F = 100.0%) as a core species. The last assemblage was found in the shallow sublittoral (50–100 m) of Ezcurra Inlet and the central basin, with Diastylis anderssoni armata (1.5 ± 1.1 ind./0.1m 2 ; F = 85.7%) and Diastylopsis goekei (1.1 ± 1.0 ind./0.1m 2 ; F = 71.4%) as the most frequent and abundant species. V. inermis is considered a eurytopic species with high frequency in the whole material, and was present in all four distinguished assemblages. E. splendida and D. goekei were also recorded in each of the assemblages, but their total frequency was lower.

The Bulletin of the Polish Academy of Sciences: Technical Sciences (Bull.Pol. Ac.: Tech.) is published bimonthly by the Division IV Engineering Sciences of the Polish Academy of Sciences, since the beginning of the existence of the PAS in 1952. The journal is peer‐reviewed and is published both in printed and electronic form. It is established for the publication of original high quality papers from multidisciplinary Engineering sciences with the following topics preferred: Artificial and Computational Intelligence, Biomedical Engineering and Biotechnology, Civil Engineering, Control, Informatics and Robotics, Electronics, Telecommunication and Optoelectronics, Mechanical and Aeronautical Engineering, Thermodynamics, Material Science and Nanotechnology, Power Systems and Power Electronics.

Journal Metrics: JCR Impact Factor 2018: 1.361, 5 Year Impact Factor: 1.323, SCImago Journal Rank (SJR) 2017: 0.319, Source Normalized Impact per Paper (SNIP) 2017: 1.005, CiteScore 2017: 1.27, The Polish Ministry of Science and Higher Education 2017: 25 points.

Abbreviations/Acronym: Journal citation: Bull. Pol. Ac.: Tech., ISO: Bull. Pol. Acad. Sci.-Tech. Sci., JCR Abbrev: B POL ACAD SCI-TECH Acronym in the Editorial System: BPASTS.

In a study on the click beetles (Coleoptera: Elateridae) of selected plant communities of the Lasy Janowskie Reserve, 21 species of these beetles were recorded – 10 each in riparian forests and a sub-Atlantic mesic coniferous forest, 11 in a continental mixed coniferous forest, and 6 in wet grassland communities. The numbers of species in the communities was similar to numbers recorded in other, comparable areas of Poland, with the exception of the wet grasslands. Forest species that can also occur outside of forests – Athous subfuscus and Dalopius marginatus – were dominant. The biodiversity of the click beetle fauna in the communities was at an average level. An ecological and zoogeographical analysis was carried out as well.

The Baltic Sea has always played a vital part in the history of Poland. In the light of the resolutions of the Yalta Conference, Poland’s boarders were shifted, including Western Pomerania in its territory. In 1945 Kołobrzeg was the most severely destroyed city on that territory. The city was either already ablaze or set on fire by German gangs active at that time. All its pre-war functions were non-existent. The harbour was immobilized, the economic basis fell apart. The city was devoided of water, power and food delivery was problematic. The newly-arrived Polish settlers perceived Kołobrzeg as a tragic and overwhelming image of a “dead city”. The area was dominated by debris, the stench of decomposing bodies of German soldiers and looters arriving from central Poland. The Wehrwolf pursued sabotages and the most terrifying Red Army committed crime and rapes. In the light of the population records and files of the Registry Office the inflow of people was rather slow during the first months, only to increase the pace in the following years. Many of them believed they would find employment rebuilding the city or in the harbour. The settlers had long been insecure about the temporary character of Poland in Western Pomerania and on the Baltic coast.

In the years 1988 and 1998-1999 botanical investigations were carried out within the projected "Diabla Góra" nature reserve, located near Bukowno town in the north-eastern part of the Silesian Upland. The occurrence of 57 taxa of bryophytes (5 liverworts and 52 mosses) as well as 248 taxa of vascular plants were reported. Among bryophytes there are 11 taxa regionally rare and endangered, for example Barbilophozia barbata and Pterigynandrum filiforme. Ten species (17.5% of brioflora) represent mountain element. Among vascular plants there are 20 protected species (8.1% of vascular flora) and 22 regionally rare and endangered taxa, for example Allium montanum, Botrychium lunaria, Orobanche caryophyllacea, Scorzonera humilis and Thalie/rum minus. Six taxa (2.4% of vascular flora) are mountain species. Eight associations (4 forest and 4 non-forest) were distinguished. The most interesting are thermophilous beech forest Carici-Fagetum and xerothermic grasslands from class Festuco-Brometea.

The preliminary results of" the research on the transformation dynamics of shrub communities in their initial developmental stage obtained from 15 permanent research plots are presented. Observations were carried out during the years 1997-99. They constitute the first phase of a long-term research aiming at the recognition or the shrub phytocoenoscs' structure. Iloristic composition, and local differentiation in various succcssi ve stages. The analysis showed that a significant increase in the volumes of shrubs was followed by a decrease in the richness or a vegetation patch. Furthermore, the role of both the taxa from the Artcmisietca class ancl, transitionally. of the meadow species becomes more visible. At the same time the plants or xcrothcrmic grasslands and thermophilous saum-communities disappear. Additionally. a significant inllucnce of the surroundings on the course of shrub colonisation was observed.

Long-term studies were performed on the development of plant communities in dumping grounds after hard coal mining. The communities were initiated by sowing grass seeds either directly in the ground with mineral fertilizing, or on separate surfaces covered with a layer of soil. The development of plant communities was assessed in various time intervals within the 30-year period. The studies concerning flora applied the Braun-Blanguet method, as well as botanical-gravimetric method. The size of biomass of surface herbaceous plants has been determined in a gravimetric manner. Plant communities with the participation of Festuca ovina initially make up monocultures, while their further development after 30 years led to the tree development of turf-like community with Betu/a verucosa and Pinus sylvestris. Such a community shows signs of substantial durability and high usability. Short-lasting grass types initiate the development of communities with Calamagrostis epigejos. On the ground covered with a layer of mineral soil the initial development of plant communities depended upon: bank of seeds in the ground, air and water conditions formed and trophic properties of the soil. Depletion of nutrients resulted in lowered production of biomass, while its collection enriched flora composition of the community, enabling the growth and development of short heliophilous plan. Depletion of plants nutrients, as well as accumulation of unmoved green biomass enabled the expansive species of Calamagrostis epigejos to settle in plant communities. The recognized natural processes in difficult habitats, initiated by grass sowing, provide the basis for correct biological reclamation of lands of Carboniferous rock waste.

The article presents empirical material obtained in sociological surveys conducted in the Wejherowo area in the year 2014. The purpose of the survey was to record the residents’ opinions on the needs and problems relating to selected functioning aspects of the town and its downtown district, the perception and valuation of the area, the town’s revitalization investments, both planned and in progress, and the perception of the changes taking place in selected spheres of the town’s life. The survey reveals that the dwellers of Wejherowo are capable of responding to the problems the town faces in intellectual and personal dimensions, they follow the postulates related to the ideas and concepts of a creative town more or less consciously, and have a preference for the town ensuring access to the broadly construed culture and entertainment. This encapsulates a vision of developing town cultures, with the focal point evidently shifted from the concept of a town as a place accumulating specimens of architecture and a symbolic space to the town construed as a complex of better facilities and solutions which make everyday life more convenient. More frequently than ever before, town identity becomes the function of negotiations between what is local and what is global. The quality of town life and the features of its ‘town-like character’ appear to be the outcome of continuous and subtle dialectics between the residents and the physical form in which they live, i.e. the town.

Social information is used by animals to communicate, but it also affects their habitat selection and preferences.

We all gesture as we talk, albeit mostly unconsciously. The gestures we produce support and supplement what we are saying. In different cultures, however, the very same gestures may carry very different meanings.

Language is used for more than just communication – it is a tool for interpreting the world around us.

Prof. Stanisław Karpiński discusses groundbreaking research into how plants communicate, remember stress, and process information.

Why is it that people can end up interpreting what is being said to them in such different ways? A lot depends on whether they happen to be in a good or bad mood.

The tale of human progress is also a story of advancements in media technologies. But should we necessarily greet the changes now on the horizon with optimism?

The Polish language is slowly disappearing among the Polish community in Ukraine’s Rivne Oblast. This is due to the influence of the clergy and the emigration of the younger generation.

The field investigations concerning water and peat bog communities on the territory of Trzebinia in 2000 revealed their little diversity caused by a small number of large water bodies and performed betterment drainages. 12 syntaxa were distinguished which represent 5 classes: Lemnetea minor is (I), Potametea (6), Utricularietea intermedio-minoris (I), Littorelletea uniflorae (I), Scheuchzerio-Caricetea nigrae (I). Among described units 3 plant associations are endangered within Upper Silesia: Myriophylletum verticillati, Hottonietum palustris, Valeriano-Caricetum flavae (montane plant association).