Drosophila Nimrod proteins bind bacteria

Engulfment of foreign particles by phagocytes is initiated by the engagement of phagocytic receptors. We have previously reported that NimC1 is involved in the phagocytosis of bacteria in Drosophila melanogaster. We have identified a family of genes, the Nimrod gene superfamily, encoding characteristic NIM domain containing structural homologues of NimC1. In this work we studied the bacterium-binding properties of the Nimrod proteins by using a novel immunofluorescencebased flow cytometric assay. This method proved to be highly reproducible and suitable for investigations of the bacteriumbinding capacities of putative phagocytosis receptors. We found that NimC1, NimA, NimB1 and NimB2 bind bacteria significantly but differently. In this respect they are similar to other NIM domain containing receptors Eater and Draper.     

Trophic relationships between primary producers and fish yields in Lake Balaton

Relationships between chlorophyll a content of the water, the shoreline-length: water area ratio and the annual total fish yield as catch per unit effort (CUE: kg ha^–1 100 h^–1 as annual mean values) have been calculated by multivariable regression. The determination coefficient (r ² = 0.913) showed a significant dependence of fish yield on morphometry of different lake areas. Accordingly, fish carrying capacity of the open water areas, calculated from chlorophyll a content and S/A, ranged from 12 to 34%, but that of the littoral zone between 66 and 88%. These findings have also been supported by echo-sounding records of the horizontal distribution of fish.Bream (Abramis brama L.) contributes the majority (70–80%) of fish stock and yield. Its food mainly consists of zooplankton and benthic invertebrates in ratios that are widely variable with season and depend on the age of fish. Average daily food consumption of individuals (age group 3 + and over) varies between 2 and 5 g. Bream consumes two- to three-times more food in the SW basin than in the NE one. This means that the present stocks inhabiting areas from NE to SW consume annually 13249–20085 t yr^–1 of food. According to estimated calorific values, the annual energy consumption of local populations along the longitudinal axis of the lake varies between 93 and 141 kJ m^–2 yr^–1. The efficiency of energy transfer from primary producers to fish is low and varies from 0.04 to 0.1%.     

Oligotrophication of Lake Balaton over a 20-year period and its implications for the relationship between phytoplankton and zooplankton biomass

Hydrobiologia - Lake Balaton, the largest lake in Central Europe, underwent severe eutrophication from the 1960s to the 1990s, due to phosphorus loadings from external anthropogenic sources. The...     

Nomenclatural and taxonomic notes on two eastern taxa of the <Emphasis Type="Italic">Primula auricula</Emphasis> complex

Discrepancies and errors in the taxonomic and nomenclatural treatment of Primula auricula complex by Zhang (2002) and Zhang & Kadereit (2004, 2005) are discussed. Investigation of a few hundred P. auricula specimens stored in BP yielded contradictory morphological results compared with those of the above authors. In contrast with the key proposed by them specimens (BP) from Mt Domogledu (Romania) have short, while those from the north Carpathians (Slovakia) have relatively long glandular hairs on the leafmargins. Lectotypes of P. auricula var. serratifolia Rochel ex Borbás and P. auricula var. hungarica Borbás are designated. Nomenclatural errors made by Zhang and Kadereit are corrected, and it is emphasized that the name P. lutea ssp. tatriaca applied for Slovak populations by them is superfluous. Further researches are needed to clarify the taxonomic position of Slovak and Romanian P. auricula populations. Morphological characters considered as distinctive and relevant by Zhang and Kadereit seem to be dependent on the phenological state of plants.     

Molecular dynamics through 2H spin-lattice relaxation time measurements within an enzyme-inhibitor complex: Lysozyme and methyl N-acetyl glucosamin

Deuteron spin-lattice relaxation times of specifically labelled methyl N-acetyl-D-glucosaminides associated to lysozyme were measured from ¹H and ²H NMR spectra through bandshape analysis and FT inversion-recovery technique, respectively. Model calculations were carried out in order to assess the limits of the extreme narrowing approximation for the systems studied. Rotational correlation times of the acelamido methyl groups were analyzed in terms of anisolropic overall reorientation combined with internal rotation. The acetamido methyl group undergoes fast internal rotation in the α-glycoside complex about an axis nearly parallel with the major ellipsoidal axis of lysozyme. More rotational freedom is likely to occur in the β-glycoside complex.     

Two components of photoreceptor potential in phototaxis of the flagellated green alga Haematococcus pluvialis

The kinetics of the photoreceptor potential of phototaxis in biflagellated green alga Haematococcus pluvialis in response to a 10-ns laser pulse of three wavelengths (465, 550, and 590 nm) were measured in single cells with 30 μs time resolution. The rise and the decay of photoinduced potential are both at least biphasic. The first component of the rise is very stable and has no measurable (<30 μs) time delay. The second component is triggered after a 120-400-μs lag period, depending on flash intensity. Its appearance is sensitive to the physiological state of the cell and the amplitude can be increased by phototactically ineffective red background illumination. The electrical generators for both components are localized in the same region of the cell membrane (on the stigma-bearing side) and these components have the same depolarizing sign. The results indicate that the photoreceptor potential in phototaxis comprises two components, which could be interpreted as light-induced charge movement within the photoreceptor molecules and changes in ion permeability of the cell membrane.     

Ocular Pentastomiasis in the Democratic Republic of the Congo

Ocular pentastomiasis is a rare infection caused by the larval stage of pentastomids, an unusual group of crustacean-related parasites. Zoonotic pentastomids have a distinct geographical distribution and utilize reptiles or canids as final hosts. Recently, an increasing number of human abdominal infections have been reported in Africa, where pentastomiasis is an emerging, though severely neglected, tropical disease. Here we describe four ocular infections caused by pentastomids from the Democratic Republic of the Congo. Two cases underwent surgery and an Armillifer grandis infection was detected by morphological and molecular approaches. Thus far, 15 other cases of ocular pentastomiasis have been reported worldwide. Twelve cases were caused by Armillifer sp., recorded almost exclusively in Africa, where such infections occur as a consequence of hunting and consuming snakes, their final hosts. Seven further cases were caused by Linguatula serrata, a cosmopolitan pentastomid whose final hosts are usually canids. Intraocular infections caused permanent visual damage in 69% and a total loss of vision in 31% of reported cases. In contrast, ocular adnexal cases had a benign clinical course. Further research is required to estimate the burden, therapeutic options and pathogenesis of this neglected disease.