Distribution of periphytic diatoms in the rivers of the Lake Ladoga basin (Northwestern Russia).

Relationships between distribution of periphytic diatoms and environmental variables in 19 rivers of the Lake Ladoga basin (Northwestern Russia) were examined using gradient analysis. On the basis of geology and river water chemistry, the Lake Ladoga basin could be separated into twomain parts, the northern and the southern sub-basin. The rivers in the northern sub-basin are slightly acidic and low in conductivity (mean value 53 mS cm–1); the rivers in the southern sub-basin have neutral to slightly alkaline waters with higher conductivities (mean value 168 mS cm–1). A detrended correspondence analysis (DCA)defined two groups of rivers generally corresponding to the two main parts of the Lake Ladoga basin. Fragilaria capucina var. rumpens, Frustulia saxonica and Tabellaria flocculosa were the typical species for the northern sub-basin, whereas Cocconeis placentula var. euglypta, Ulnaria ulna and Gomphonema parvulum were characteristic species for the southern sub-basin. A canonical correspondence analysis (CCA) identified conductivity, pH, bicarbonate, total phosphorus and water colour as the most important environmental variables related to changes in assemblage structure. Both DCA and CCA ordination showed that conductivity related to geology was the most important variable,while concentration of total phosphorus was the second most important variable.Weighted averaging was used to infer total phosphorus from relative biomass of diatoms. The predictive ability of the inference model was sufficiently strong with r2 = 0.71 and RMSEP = 1.9 mg L–1. These results strongly support the use of a diatom-based inference phosphorus model for indicating eutrophication in the rivers of the Lake Ladoga basin

Computing all possible graph structures describing linearly conjugate realizations of kinetic systems

In this paper an algorithm is given to determine all possible structurally different linearly conjugate realizations of a given kinetic polynomial system. The solution is based on the iterative search for constrained dense realizations using linear programming. Since there might exist exponentially many different reaction graph structures, we cannot expect to have a polynomial-time algorithm, but we can organize the computation in such a way that polynomial time is elapsed between displaying any two consecutive realizations. The correctness of the algorithm is proved, and possibilities of a parallel implementation are discussed. The operation of the method is shown on two illustrative examples

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

A korai kezdetu ujszulottkori B csoportu Streptococcus-szepszis megelozesenek helyzete Magyarorszagon 2012-ben. Egy orszagos felmeres adatai.

Introduction: At present, there is no obligatory guideline for the prevention of early-onset neonatal group B streptococcal disease in Hungary. Aim: The aim of the present study was to gain insight into the spontaneously developed preventive strategy of the domestic obstetric divisions and departments in Hungary. Method: Standardized questionnaire was sent out to each of the 71 obstetric divisions and departments in Hungary. Results: Overall, 20 (27.4%) of the chairpersons replied, and thus, 39.9% of the total number of live births in Hungary were included in the study. Despite missing public health guidelines, each of the divisions and departments developed their own strategy to prevent neonatal group B streptococcal disease. In 95% of cases, bacterial culture of the lower vagina was the method of identifying pregnant women at risk. In 5% of the cases intrapartum antibiotic prophylaxis was based on risk assessment only. Of the departments using culture-based prophylaxis, 58% departments sampled women after completion of 36th gestational weeks. Antibiotic of choice was penicillin or ampicillin in 100% of cases. Of the study participants, 80% reported on multiple administration of colonized pregnant women after onset of labor or rupture of the membranes. Conclusions: The authors concluded that the rate of participation in the study was low. However, prevention of early-onset neonatal group B streptococcal infection is a priority of obstetric care in Hungary. Lack of a nation-wide public health policy did not prevent obstetric institutions in this country to develop their own prevention strategy. In the majority of cases and institutions, the policy is consistent with the widely accepted international standards. Orv. Hetil., 2014, 155(29), 1167-1172

New records of macrochelid mites and description of a new phoretic species (Acari: Mesostigmata: Macrochelidae) from Greece

Ács, A., Sutak, A., Kontschan, J. (2016): New records of macrochelid mites and description of a new phoretic species (Acari: Mesostigmata: Macrochelidae) from Greece. Acarologia 56 (1): 63-71, DOI: 10.1051/acarologia/20162188, URL: http://dx.doi.org/10.1051/acarologia/2016218