Changes in the algal composition, bacterial metabolic activity and element content of biofilms developed on artificial substrata in the early phase of colonization

Changes in the algal composition and metabolic profiles of bacterial communities as well as the inorganic components were studied on artificial substrata during the early phase of biofilm formation under laboratory conditions in September 2002 and 2003. Sterile Perspex and polished quartz glass discs with a diameter of 3 cm were placed into a Perspex rack, which was immersed vertically in an aquarium containing water from a shallow soda lake. The temperature was kept constant and sufficient oxygen supply was provided. The samples were illuminated for 12 hours a day. Periphyton communities were sampled from 2 to 126 hours of exposure. In both experiments, the alteration of the number of algal species and cells as well as the carbon source utilization of microbial communities was logarithmic. In the two years, considerable differences were revealed in the magnitude of algal cell numbers. The proportion of benthic and planktonic algae showed an undulating pattern in the second experiment. One of the dominant benthic species was the diatom Achnanthidium minutissimum Kütz., while that of the planktonic, the cyanobacterium Microcystis aeruginosa Kütz. During the experiments an increase in the bacterial activities could be observed; the higher the microbial diversity and abundance that was detected, the more BIOLOG carbon sources were utilized. The examined element contents indicated interactions among algae and bacteria in the biofilms from the beginning of the colonization processes

Comparative algological and bacteriological examinations on biofilms developed on different substrata in a shallow soda lake

According to the European Water Framework Directives, benthic diatoms of lakes are a tool for ecological status assessment. In this study, we followed an integrative sample analysis approach, in order to find an appropriate substratum for the water qualification-oriented biomonitoring of a shallow soda lake, Lake Velencei. Six types of substrata (five artificial and one natural), i.e., andesite, granite, polycarbonate, old reed stems, Plexiglass discs and green reed, were sampled in May and in November. We analysed total alga and diatom composition, chlorophyll a content of the periphyton, surface tension and roughness of the substrata and carbon source utilisation of microbial communities. Water quality index was calculated based on diatom composition. Moreover, using a novel statistical tool, a self-organising map, we related algal composition to substratum types. Biofilms on plastic substrates deviated to a great extent from the stone and reed substrata, with regard to the parameters measured, whereas the biofilms developing on reed and stone substrata were quite similar. We conclude that for water quality monitoring purposes, sampling from green reed during springtime is not recommended, since this is the colonization time of periphyton on the newly growing reed, but it may be appropriate from the second half of the vegetation period. Stone and artificially placed old reed substrata may be appropriate for biomonitoring of shallow soda lakes in both spring and autumn since they showed in both seasons similar results regarding all measured features

Investigation of lead and nickel contaminated natural biofilms

Total reflection X-ray fluorescence spectrometric method was developed for elemental analysis of lead and nickel contaminated natural biofilms grown on polycarbonate substrates. The biofilms were grown in the Lake of Velence for 4 weeks and then in the laboratory in contaminated lake water for other 2 weeks. It was established that the accumulation of these bivalent cations were practically the same and in their presence the accumulation of zinc decreased by approximately 20% while the other elements (Ca, K, Fe, Mn, Sr, Ti, Rb) showed smaller changes within the statistical interval. From biological point of view, these two bivalent cations reduced the abundance of the algae, to a similar extent; however, the total biomass production was significantly hampered only by nickel (14%)

Study of biofilm formation by total-reflection X-ray fluorescence spectrometry

A total reflection X-ray fluorescence spectrometric method was developed for elemental analysis of natural biofilms grown on polycarbonate substrates in the Lake Velence. For the duration of 9 weeks long growing period, two substrates were removed weekly from the lake and investigated by analytical and algological methods. The total biomass production achieved its highest value after 7 weeks. Ca, Sr and Ti, as well as Fe, Mn, K and Zn showed their maximum concentrations in the biofilms after 5 and 6-7 weeks, respectively. The enrichment factors of the 6 weeks old biofilm for the detected seven elements amounted to 10(3)-10(4). The recommended colonization time for biomonitoring of the Lake Velence is 6 weeks applying polycarbonate substrates

Drugs for treatment of benign prostatic hyperplasia: affinity comparison at cloned alpha 1-adrenoceptor subtypes and in human prostate

1. We have previously shown that among alpha 1-adrenoceptor antagonists used or investigated for the treatment of benign prostatic hyperplasia, tamsulosin discriminates alpha 1-adrenoceptor subtypes in rat tissues whereas alfuzosin and naftopidil do not. We now expand these studies to additional drugs (doxazosin, terazosin) being used and/or investigated for this purpose, and have evaluated all of these drugs at cloned subtypes and in human prostate. 2. Competition binding studies were performed with [3H]-prazosin in membrane samples from rat spleen, kidney and cerebral cortex and human prostate and with cloned alpha 1-adrenoceptors expressed in COS cells. Doxazosin and terazosin did not discriminate alpha 1-adrenoceptor subtypes in rat kidney and cerebral cortex. In contrast, the subtypes present in the tissues were well discriminated by the alpha 1A-adrenoceptor-selective reference drug WB 4101. 3. Alfuzosin, doxazosin, naftopidil and terazosin did not discriminate cloned alpha 1-adrenoceptor subtypes transiently expressed in COS cells whereas tamsulosin and WB 4101 did. 4. In human prostate, alfuzosin, doxazosin, naftopidil and terazosin did not discriminate the alpha 1-adrenoceptor subtypes present in this tissue whereas tamsulosin and the alpha 1A-adrenoceptor-selective reference drugs WB 4101, phentolamine and 5-methylurapidil did. Based on data with the alpha 1A-adrenoceptor-selective drugs, human prostate contains alpha 1A- and alpha 1B-adrenoceptors in an approximate 70:30% ratio. 5. We conclude that tamsulosin, in common with WB 4101, but in contrast to alfuzosin, doxazosin, naftopidil, and terazosin is selective for alpha 1A-adrenoceptors which appear to dominate in the human prostate; the therapeutic relevance of this selectivity remains to be assessed in clinical studie

Wireless M-bus in industrial IoT: Technology overview and prototype implementation

During the past 15 years, the Internet revolution has redefined the industry landscape. The advent of the Internet of Things (IoT) is changing our lives by provisioning a wide range of novel applications that leverage the ecosystem of "smart" and highly heterogeneous devices. This is expected to dramatically transform manufacturing, energy, agriculture, transportation, and other industrial sectors. The Industrial Internet of Things (IIoT) brings along a new wave of Internet evolution and will offer unprecedented opportunities in Machine Type Communications (MTC) - intelligent industrial products, processes, and services that communicate with each other and with people over the global network. This paper delivers a technology overview of the currently utilized Wireless M-Bus communication protocol within the IIoT landscape together with describing a demonstration prototype development. In our trial implementation, the IQRF modules are utilized to be compatible with the protocol of interest. The constructed WM-Bus receiver is further integrated as part of a complex MTC Gateway, which receives the MTC data via a secure communication channel from various types of smart-metering devices. © VDE VERLAG GMBH · Berlin · Offenbach

Chemical and biological characterisation of biofilms formed on different substrata in Tisza river (Hungary)

Natural biofilms were simultaneously grown on granite, polished granite, andesite, polycarbonate and Plexi-glass substrata for six weeks in the Tisza River. Biofilm production and abundance of algae were influenced by the substratum. Magnitude of the substratum effect was andesite < polished granite < Plexi-glass < granite < polycarbonate. The benthic diatom community on polycarbonate had a high population of Achnantes helvetica. Bacterial activity was similar among substrates for 95 different carbon sources. The concentrations of essential elements and heavy metal pollutants (Zn, Ni, Pb and Cu) were highest in biofilms on polished granite or granite. On basis of algological, bacteriological and chemical investigations, as well as literature data, the Plexi-glass substratum is recommended for biomonitoring of river benthic microbiota

Wireless M-bus in industrial IoT: Technology overview and prototype implementation

During the past 15 years, the Internet revolution has redefined the industry landscape. The advent of the Internet of Things (IoT) is changing our lives by provisioning a wide range of novel applications that leverage the ecosystem of "smart" and highly heterogeneous devices. This is expected to dramatically transform manufacturing, energy, agriculture, transportation, and other industrial sectors. The Industrial Internet of Things (IIoT) brings along a new wave of Internet evolution and will offer unprecedented opportunities in Machine Type Communications (MTC) - intelligent industrial products, processes, and services that communicate with each other and with people over the global network. This paper delivers a technology overview of the currently utilized Wireless M-Bus communication protocol within the IIoT landscape together with describing a demonstration prototype development. In our trial implementation, the IQRF modules are utilized to be compatible with the protocol of interest. The constructed WM-Bus receiver is further integrated as part of a complex MTC Gateway, which receives the MTC data via a secure communication channel from various types of smart-metering devices. © VDE VERLAG GMBH · Berlin · Offenbach