Altered stimulus frequency and intensity dependence of the somatosensory evoked potential in rats after acute application of two mitochondrial toxins

Mitochondrial toxins are a special group of toxicants with nervous system ef TRACT - fects. The resulting nervous system damage could be detected and followed-up by means of functional biomarkers but these still have to be worked out. In this work, adult male Wistar rats were anesthetized with urethane, the left hemisphere was exposed, and a silver recording electrode was placed on the projection area of the whiskers. The whisker pad was stimulated with electric square pulses and the cortical response was recorded. The intensity of the stimulus was varied between 25% and 100% (just supramaximal), and its frequency, between 1 and 10 Hz. Control records were taken, then one of the agents (3-nitrporopionic acid, a mitochondrial toxin of microfungal origin: 20 mg/kg b.w.; or manganese, a heavy metal: 50 mg/kg b.w. in chloride form) was injected ip. and further records were taken. Both agents had an effect on the latency, but on the amplitude, only Mn. Of the relationships between stimulation settings and evoked potential parameters, frequency dependence of latency had the clearest alteration on application of Mn or 3-NP. Such effects may have the potency to be developed to functional biomarkers, applicable in practical toxicology or in animal research

New measurements of thousand-seed weights of species in the Pannonian flora

For understanding local and regional seed dispersal and plant establishment processes and for considering the ecotypes and other forms of specific variability, hard data of locally or regionally measured traits are necessary. We provided newly measured seed weight data of 193 taxa, out of which 24 taxa had not been represented in the SID, LEDA or BiolFlor databases. Our new measurements and formerly published data of locally collected seed weight records together covers over 70% of the Pannonian flora. However, there is still a considerable lack in seed weight data of taxonomically problematic genera, even though they are represented in the Pannonian flora with a relatively high number of species and/or subspecies (e.g. Sorbus, Rosa, Rubus, Crataegus and Hieracium). Our regional database contains very sporadic data on aquatic plants (including also numerous invasive species reported from Hungary and neighbouring countries) and some rare weeds distributed in the southwestern part of the country. These facts indicate the necessity of further seed collection and measurements

Restricted by borders: trade-offs in transboundary conservation planning for large river systems

Effective conservation of freshwater biodiversity requires accounting for connectivity and the propagation of threats along river networks. With this in mind, the selection of areas to conserve freshwater biodiversity is challenging when rivers cross multiple jurisdictional boundaries. We used systematic conservation planning to identify priority conservation areas for freshwater fish conservation in Hungary (Central Europe). We evaluated the importance of transboundary rivers to achieve conservation goals by systematically deleting some rivers from the prioritization procedure in Marxan and assessing the trade-offs between complexity of conservation recommendations (e.g., conservation areas located exclusively within Hungary vs. transboundary) and cost (area required). We found that including the segments of the largest transboundary rivers (i.e. Danube, Tisza) in the area selection procedure yielded smaller total area compared with the scenarios which considered only smaller national and transboundary rivers. However, analyses which did not consider these large river segments still showed that fish diversity in Hungary can be effectively protected within the country’s borders in a relatively small total area (less than 20 % of the country’s size). Since the protection of large river segments is an unfeasible task, we suggest that transboundary cooperation should focus on the protection of highland riverine habitats (especially Dráva and Ipoly Rivers) and their valuable fish fauna, in addition to the protection of smaller national rivers and streams. Our approach highlights the necessity of examining different options for selecting priority areas for conservation in countries where transboundary river systems form the major part of water resources.Full Tex

THE SYSTEM OF ENVIRONMENTAL DAMAGES AND THEIR ECONOMIC EFFECT ASSESSED BY WAY OF MATRIX STRUCTURE

One of today’s most vigorous tasks is to tackl e the challenges presented by climate change. In order to develop a better understanding of envir onmental damages caused by human activities, a new approach is necessary. Neither the usual co mprehensive analytic tools encompassing the aggregate national economy as a whole, nor the indicators expressing details in an isolated way are capable of providing an answer to such problems The paper proposes a new method for environmental impact assessment by enumerating cross- sectoral damages using a model similar to the crossindustry input-output approach. The proposed methodology would allow decision makers to assess national economy level decisions by exploring cross-sectoral relationships with environmental impacts