Abstract

This is a personal view to the development of the zoophysiology laboratory at the Biology department of Biotechnical faculty of the University of Ljubljana and the National Institute of Biology. This review mainly covers 27 years of my life in this institution with projections to the present state. For a comprehensive history one should thoroughly study documents in the archives of institutions, mentioned above.

Keywords

zoophysiology, animal physiology, Department of Biology BF, Institute of Biology, University of Ljubljana

Abstract

The objective of the article is to present the results of a survey of attitudes toward genetic modified organisms, conducted by questionnaire given to 359 prospective primary school teachers from three Slovene pedagogical faculties. Analysis of their answers, their agreement or disagreement with statements connected with GMOs, reveals uncertainty, distrust and rejection. By factorial analysis of their answers we identified and evaluated some of the concerns and fears connected with emerging new technologies, attitudes toward education about GMOs and levels of trust in scientific research.

Keywords

genetically modified organisms, GMO, prospective primary school teachers, students of elementary education

Abstract

We review some new literature on diatoms, with emphasis on genomics, evolution, ecology and biomimetic nanotechnical applications. Diatoms account for a substantial part of the photosynthetic production on this planet, and their genome is a mosaic of contributions from different sources. They occupy very diverse ecological niches, and may have been the first organisms to carry out C4 photosynthesis. Their frustrules (silica enclosures) with their elaborate sculpturing make it possible to follow the occurence of different forms back in time, and the frustrules is also the main reason that they are interesting for biotechnology.

Keywords

C4 photosynthesis, chloroplasts, diatoms, dynamite, endosymbiosis, nanotechnology, omega-3 fatty acid, silica

Abstract

Substrate-induced respiration (SIR) was used to estimate microbial respiration and microbial biomass in soils from Stavešinci natural CO 2 spring (mofette) exposed to different geological CO 2 concentrations. SIR measurements clearly demonstrated higher microbial respiration and microbial biomass in control sites compared to high soil CO 2 sites. Sampling in two different locations and in three different years also confirmed long-term stability of this pattern, which was found for both locations and in different sampling periods.

Keywords

substrate-induced respiration, SIR, microbial respiration, microbial biomass, soil respiration, natural CO 2 springs, mofette

Abstract

The species composition of phytoplankton in the artificial lake Velenjsko jezero has been monitored since 1994 while physico-chemical characteristics of the lake water since 1998. Before the year of lake remediation, 1994, the pH of lake water was around 12. In 1994, only filamentous cyanobacteria Oscillatoria ssp. were present in high abundance, with the rare appearance of Synedra sp. and Ceratium sp.. In 1995, the pH in the upper water layers decreased to 9, as a consequence of the construction of a fly ash system with a closed loop water cycle in October 1994. The number of algae taxons increased to 7 ( Coelosphaeria sp., Gomphosphaeria sp., Scenedesmus sp., Pediastrum sp., Asterionella sp., Synedra sp. and Ceratium sp.). In 1996, when the pH fell to 8, it increased to 13. The lake provided good conditions for algal development since it was rich in nutrients. Since 1996 the level of nutrients in the upper layers of the water column has remained more or less the same, but in the deeper layers the reduced form of nitrogen (NH 4 + ) has increased and the oxygen curve has become clinograd. Velenjsko jezero can be classified according to OECD, as hypereutrophic on the basis of the level of total phosphorus (120 μg L –1 ) and total nitrogen (1500 μg L –1 ), the average transparency of 5.38 m corresponds to mesoeutrophic status, and the average concentration of chlorophyll a at 1.03 μg L –1 to oligotrophic status. Despite the high availability of nutrients the primary production was not as high as in a similar natural lake ecosystem, which could be ascribed to the high concentration of ions Ca 2+ , K + , Mg 2+ , Na + , Cl – and particularly, SO 4 2– . The predominant algae in the lake in 2007 were cyanobacteria Pseudanabaena cf. catenata, Planktothrix rubescens , from which the first bloom occured in June and the second from November to January, and dynophyta Ceratium hirundinella and Peridinium cinctum .

Keywords

pH, lake water, nutrients, phytoplankton

Abstract

The impact of simultaneous Cd and Zn amendments in the substrate on the accumulation of Cd and Zn were studied in a recently discovered Cd/ Zn hyperaccumulating Thlaspi praecox (Brassicaceae) and compared to a model hyperaccumulating plant species T. caerulescens . The plants were grown in pots with added Cd or Zn or both for three months in a greenhouse. The addition of Zn in the substrate increased Cd extractability in the substrate significantly without a significant pH change and this increase resulted in increased concentration and content of Cd in the shoots of both species indicating that species have similar abilities to extract Cd from the substrate. In the combined treatment (Cd and Zn) an increase in shoot biomass accompanied with a decrease in Zn concentration in roots and shoots of both species was observed, while no changes in total accumulated Zn in shoots were seen. These results suggest different uptake and translocation systems for Cd and Zn in T. praecox, positioning this plant species in the superior Cd hyperaccumulating league of T. caerulescens Ganges ecotype.

Keywords

Thlaspi caerulescens , Thlaspi praecox , cadmium uptake, hyperaccumulation, zinc uptake

Abstract

The aim of the presented study was to estimate the prevalence, distribution and associations of different pathogenicity islands (PAI I 536 to PAI IV 536 , PAI I J96 , PAI II J96 , PAI I CFT073 and PAI II CFT073 ), iron uptake systems (genes iutA , iucD , iroN , iroCD , fyuA , irp2 , iha , ireA , and hbp ) and plasmids among extraintestinal pathogenic Escherichia coli (ExPEC) strains isolated from Slovenian patients. Twenty-nine ExPEC isolates obtained from the Institute of Microbiology and Immunology, Medical Faculty, University of Ljubljana were investigated for the presence of different pathogenicity islands and iron uptake systems with PCR, the plasmid content of the investigated strains was determined by molecular biology techniques. The significance of the found associations of the studied PAIs and iron uptake systems was analyzed with the Fisher’s exact test. PAI IV 536 was found in 19, PAI II CFT073 in 6, PAI I CFT073 in 4, and PAI II J96 in one of the studied isolates. PAI I 536 , PAI II 536 , PAI III 536 and PAI I J96 were not detected in any studied isolate. In 19 of the studied isolates plasmids were detected. The irp2 was found in 20, fyuA in 19, iucD and iutA in 12, iha in 9, iroN in 8, iroCD in 7, ireA in 7 and hbp in 4 of studied isolates. PAI IV 536 was statistically significantly associated with the yersiniabactin siderophore system and PAI I CFT073 was statistically significantly associated with the aerobactin siderophore system as well as Iha. To our knowledge this is the first report on PAIs and iron uptake systems among Slovenian ExPEC isolates, as well as a first report on PAIs, iron uptake systems and plasmids among isolates from skin and soft tissue infections.

Keywords

extraintestinal pathogenic Escherichia coli , ExPEC, pathogenicity island, PAI, plasmid, iron uptake

Abstract

In the present study we determined the toxicity of chlormephos to two common soil organisms – earthworms ( Eisenia andrei ) and isopods ( Porcellio scaber ) using Lufa 2.2 soil. The LC 50 values for the effects on earthworm and isopod survival were 58 and 76 mg/kg dry soil, respectively. Mass change of earthworms and behaviour of isopods were more sensitive end points as survival. Based on earthworm body mass changes, NOEC and LOEC values were 1 and 3 mg/kg dry soil, respectively. The earthworms did not reproduce even at the lowest chlormephos concentration (LOEC < 1 mg/kg dry soil). Isopods significantly avoided burrowing in soil treated with ≥40 mg/kg dry soil. Compared with some other organophosphate insecticides, chlormephos was highly toxic to beneficial terrestrial invertebrates.

Keywords

ecotoxicity; organophosphates; chlormephos; soil exposure; soil invertebrates

Abstract

Vesicles are cellular organelles, in which signaling molecules (neurotransmitters or hormones) are stored and are essential for the function of neurons and endocrine cells in supporting the communication between tissues and organs. Upon stimulation the signaling molecules stored inside vesicles are released from cells by exocytosis. This fundamental biological process consists of membrane fusion between the vesicles and the plasma membrane, leading to the formation of an aqueous channel – the fusion pore – through which signaling molecules exit into the extracellular space or blood stream. The vesicle cargo discharge initially requires the delivery of vesicles to the plasma membrane, where vesicles dock and get primed for fusion with the plasma membrane. Classical view holds that stimulation initiates the fusion pore formation and vesicle cargo discharge in an all-or-none fashion. Once formed the fusion pore may close (transient, “kiss-and-run” exocytosis) or expand, leading to the full collapse of the vesicle membrane into the plasma membrane (full fusion exocytosis). However, recent studies indicate that exocytosis may not be as simple. Here we highlight the novel findings which indicate that transient fusion pore is subject to regulations, which affect the release competence of a single vesicle. Our recent studies have shown that in pituitary lactotrophs vesicle release of peptide signaling molecules involves modulation of fusion pore kinetics and fusion pore conductance.

Keywords

exocytosis, vesicle, fusion pore, transient/full fusion, pituitary lactotrophs, peptide hormones

Abstract

In investigations of soil arthropods, different methods are used for collecting specimens. During centipede community investigation in unevenly aged beech stand in Dinaric forests in Slovenia pitfall traps with leading boards were used to catch centipedes that walked in a certain direction. In present paper these traps and catching centipedes using them is presented. In studied stand 30 pitfall traps (each having 2 collecting vessels) with leading boards were placed and emptied through the whole year of 2003. 2367 centipedes from 37 species (out of 44 species already found in this stand) were caught. The majority of catch presents well mobile, bodily bigger epigeic lithobiids that prefer litter layer. The portion of juveniles was very low.

Keywords

sampling methods, pitfall-trapping, migration, community dynamics, soil arthropods