Parthenogenetic capability of three species in Poa pratensis L. aggregation

Parthenogenesis, as an asexual reproductive method gives rise to a new prospect in agricultural production: the opportunity to establish genetically stable, seed-propagating clones of crops, which can perpetuate themselves across countless sporophytic generations. Apomictic processes of Poa pratensis has been extensively discussed by several studies. We studied the parthenogenesis capability of species in Poa pratensis L. aggregation collected from seminatural habitats by auxin-test. The article presents that this asexual mode of reproduction occurs in two other species of the Poa pratensis group, in Poa angustifolia and Poa humilis too. The results add more information to the reproductive behavior of these Poa species and could be useful in plant breeding

The effect of the implementation of ultrasound in enzyme separation

Enzymes are biological catalysts that generally are designed to do one job well, but to do one job only. Therefore, the enzymes that catalyze the hydrolysis of cellulose to sugar do not break down the sugars. Enzymatic hydrolysis processes have been under development for only 10 years. The important research issues include understanding the processes necessary to render the crystalline cellulose easily digestible, understanding and improving the basic mechanisms in the hydrolysis step, and developing better and less expensive enzymes. The other way to make a process less expensive may be the recycling of enzymes. The essential unit operation in the bioethanol production is the cellulose enzymatic degradation, so the question of recycling is very important. In our work the sonication assisted ultrafiltration was investigated as a potential method for enzyme recycling. The results showed the ultrasound effects the permeate flux since the resistance is reduced by the sonication. The sonicated enzyme keeps its activity so the recycling mechanism might be used for bioethanol production

Atomic Force Microscopy of height fluctuations of fibroblast cells

We investigated the nanometer scale height fluctuations of 3T3 fibroblast cells with the atomic force microscope (AFM) under physiological conditions. Correlation between these fluctuations and lateral cellular motility can be observed. Fluctuations measured on leading edges appear to be predominantly related to actin polymerization-depolymerization processes. We found fast (5 Hz) pulsatory behavior with 1--2 nm amplitude on a cell with low motility showing emphasized structure of stress fibres. Myosin driven contractions of stress fibres are thought to induce this pulsation.Comment: 6 pages, 5 figures, 1 tabl

Excavation along the easternmost frontier of the LBK in NE-Hungary at Apc-Berekalja I (2008–2009)

The topographical position and size of the site, the number of detected houses, the presence of the early phase make the Apc-Berekalja I settlement one of the most significant sites of the LBK in Hungary. The ongoing processing of the excavation data provided already some very important observations. The geoarchaeological results demonstrated the presence of the in situ soil of the Neolithic period and effects of floods on the settlement. The study of the chipped and ground stone material coming from the Neolithic features revealed no conspicuous changes in the lithic industry of the settlement from the pre-Notenkopf to Želiezovce phases of the LBK. Lithic raw materials came exclusively from territories to the east of the site, which is an evidence of the isolation of the LBK groups that inhabited Apc. | Földrajzi helyzete, a lelőhely mérete, a megfigyelt házak száma és a korai fázis megléte alapján Apc-Berekalja I. az egyik legjelentősebb magyarországi VK-település. Az ásatási adatok még folyamatban lévő feldolgozása során közlésre méltó eredmények születtek. A geoarcheológiai vizsgálatok kimutatták egy neolitikus korú talaj in situ meglétét, valamint a települést sújtó áradásokat. A neolitikus korú objektumokból származó pattintott és szerszámkövek a település fennállása alatt a kőipar lényegi változatlanságáról tanúskodnak a VK korai időszakától a zselízi fázisáig. A településen élők a kőnyersanyagokat kizárólag a keletre eső területekről szerezték be, ami az itt lakó csoport izoláltságát igazolja

A Rasch model analysis of two interpretations of ‘not relevant’ responses on the Dermatology Life Quality Index (DLQI)

Purpose Eight of the ten items of the Dermatology Life Quality Index (DLQI) have a ‘not relevant’ response (NRR) option. There are two possible ways to interpret NRRs: they may be considered ‘not at all’ or missing responses. We aim to compare the measurement performance of the DLQI in psoriasis patients when NRRs are scored as ‘0’ (hereafter zero-scoring) and ‘missing’ (hereafter missing-scoring) using Rasch model analysis. Methods Data of 425 patients with psoriasis from two earlier cross-sectional surveys were re-analysed. All patients completed the paper-based Hungarian version of the DLQI. A partial credit model was applied. The following model assumptions and measurement properties were tested: dimensionality, item ft, person reliability, order of response options and diferential item functioning (DIF). Results Principal component analysis of the residuals of the Rasch model confrmed the unidimensional structure of the DLQI. Person separation reliability indices were similar with zero-scoring (0.910) and missing-scoring (0.914) NRRs. With zero-scoring, items 6 (sport), 7 (working/studying) and 9 (sexual difculties) sufered from item misft and item-level disordering. With missing-scoring, no misft was observed and only item 7 was illogically ordered. Six and three items showed DIF for gender and age, respectively, that were reduced to four and three by missing-scoring. Conclusions Missing-scoring NRRs resulted in an improved measurement performance of the scale. DLQI scores of patients with at least one vs. no NRRs cannot be directly compared. Our fndings provide further empirical support to the DLQI-R scoring modifcation that treats NRRs as missing and replaces them with the average score of the relevant items

Membrane vesicles, current state-of-the-art: emerging role of extracellular vesicles

Release of membrane vesicles, a process conserved in both prokaryotes and eukaryotes, represents an evolutionary link, and suggests essential functions of a dynamic extracellular vesicular compartment (including exosomes, microparticles or microvesicles and apoptotic bodies). Compelling evidence supports the significance of this compartment in a broad range of physiological and pathological processes. However, classification of membrane vesicles, protocols of their isolation and detection, molecular details of vesicular release, clearance and biological functions are still under intense investigation. Here, we give a comprehensive overview of extracellular vesicles. After discussing the technical pitfalls and potential artifacts of the rapidly emerging field, we compare results from meta-analyses of published proteomic studies on membrane vesicles. We also summarize clinical implications of membrane vesicles. Lessons from this compartment challenge current paradigms concerning the mechanisms of intercellular communication and immune regulation. Furthermore, its clinical implementation may open new perspectives in translational medicine both in diagnostics and therapy

Autogenous Bone Versus β-Tricalcium Phosphate Graft Alone for Bilateral Sinus Elevations (2- and 3-Dimensional Computed Tomographic, Histologic, and Histomorphometric Evaluations): Preliminary Results

The aim of this research was to compare 2 different graft materials, β-tricalcium phosphate (Cerasorb) and autogenous bone, used in the same patient. Bilateral sinus grafting was performed on 4 selected patients; Cerasorb only was used on the experimental side, and autogenous bone only was used on the control side. In all 4 patients, the maxilla was atrophied to such an extent that the reconstruction included not only sinus grafting but also onlay plasty. The procedure was followed by implant placement 6 months later. In addition to routine panoramic radiographs, 2- and 3-dimensional computed tomographic (CT) examinations were performed pre- and postoperatively and after implantation. Information from CTs is necessary when alveolar bone atrophy is extensive, complications appear probable, and in difficult cases, when exact documentation is important. A total of 16 bone biopsies were taken at the time of implant placement. The histologic and histomorphometric results indicated that when the formation of new bone was slow, it was slow on both sides; when it was fast, then it was fast on both sides. Individual patient factors strongly influenced the fates of the various graft materials in the organism. Comparisons of the present results with the findings of other investigators demonstrated that β-tricalcium phosphate is a satisfactory graft material, even without autogenous bone

Frond-level analyses reveal functional heterogeneity within heavy metal-treated duckweed colonies

Duckweeds (Lemnaceae) rapidly produce clonal populations that make them ideal models in plant physiological and ecotoxicological research. Yet, despite their genetic homogeneity, duckweed colonies are clusters of successively produced fronds with different ontogenetic states, and this heterogeneity has rarely been studied. We analyzed frond-level photosynthetic responses of three duckweed species (Spirodela polyrhiza, Landoltia punctata and Lemna minor) to hexavalent chromium and nickel by means of chlorophyll fluorescence imaging. Our aim was to test whether fronds, or frond zones in their different developmental stages respond differently to heavy metal stress. Different response patterns were found for the three tested species. Young fronds of S. polyrhiza were more sensitive to chromate but less affected by nickel compared to mature ones, while in La. punctata the opposite was found. In Le. minor cultures, young fronds were more sensitive to both heavy metals compared to mature ones. Within-frond patterns indicated that chromate inhibited the marginal frond regions strongest. In La. punctata and Le. minor, nickel was most detrimental in the developing frond regions. In contrast, in S. polyrhiza the middle zone of both young and mature fronds was affected strongest by nickel. The observed patterns suggest that internal redistribution of toxicants plays a key role in shaping duckweed responses.Results highlight that ontogenetically different parts of duckweed plants respond differently to environmental stimuli. Since duckweed-based impact studies and economical applications rely strongly on the interactions between the duckweed colony and its environment, frond-, and within-frond level analysis of duckweed responses comprise a unique tool to reveal uptake, re-distribution and mode of action of environmentally relevant substances

Species- and Metal-Specific Responses of the Ionome of Three Duckweed Species under Chromate and Nickel Treatments

In this study, growth and ionomic responses of three duckweed species were analyzed, namely Lemna minor, Landoltia punctata, and Spirodela polyrhiza, were exposed for short-term periods to hexavalent chromium or nickel under laboratory conditions. It was found that different duckweed species had distinct ionomic patterns that can change considerably due to metal treatments. The results also show that, because of the stress-induced increase in leaf mass-to-area ratio, the studied species showed different order of metal uptake efficiency if plant area was used as unit of reference instead of the traditional dry weight-based approach. Furthermore, this study revealed that μXRF is applicable in mapping elemental distributions in duckweed fronds. By using this method, we found that within-frond and within-colony compartmentation of metallic ions were strongly metal- and in part species-specific. Analysis of duckweed ionomics is a valuable approach in exploring factors that affect bioaccumulation of trace pollutants by these plants. Apart from remediating industrial effluents, this aspect will gain relevance in food and feed safety when duckweed biomass is produced for nutritional purposes