Leaching of nitrate and ammonium in heathland and forest ecosystems in Northwest Germany under the influence of enhanced nitrogen deposition

To study the impact of high atmospheric nitrogen deposition on the leaching of NO₃^– and NH₄⁺ beneath forest and heathland vegetation, investigations were carried out in adjacent forest and heathland ecosystems in Northwest Germany. The study area is subjected to high deposition of nitrogen ranging from 15.9 kg ha^–1 yr^–1 in bulk precipitation to 65.3 kg ha^–1 yr^–1 beneath a stand of Pinus sylvestris L. with NH₄–N accounting for 70–80% of the nitrogen deposited. Considerable leaching of nitrogen compounds from the upper horizons of the soil, mostly as nitrate, occurred at most of the forest sites and below a mixed stand of Calluna vulgaris (L.) Hull. and Erica tetralix, but was low in a Betula pubescens Ehrh. swamp forest as well as beneath Erica tetralix L. wet heath and heath dominated by Molinia caerulea(L.) Moench. Ground water concentrations of both NO₃–N and NH₄–N did not exceed 1 mg L^–1 at most of the sites investigated.     

Diagnostic significance of connective tissue enzymes

In spite of the extensive literature, little is known of the diagnostic value of the enzymes of connective tissue metabolism. This review summarizes the available information and assesses the significance of enzyme measurements for the diagnosis of hereditary and nonhereditary connective tissue diseases, with emphasis being given to the roles of abnormal activities of collagenases and lysosomal glycosidases in the detection of fibrotic processes.     

Morphological and phenological strategies for flooding tolerance in Cerrado and Pantanal trees: implications for restoration under new legislation

In 2012, the Native Vegetation Protection Law 12,651 decreased the extent of Areas of Permanent Preservation in Brazil. While previously the distance from water was measured during the rainy season, the new version only considered the extent of the regular watercourse. This change affects conservation and restoration sites, and restoration programs need to be modified based on the new legislation. For instance, more flood-tolerant species need to be planted, given the higher probability that restoration efforts will be lost during flooding. To identify species suitable for the restoration of such areas, we tested if plants that develop morphological structures to tolerate waterlogging stress are more resistant to hypoxia caused by flooding and can recover better afterwards. We experimentally evaluated survival and morphological or phenological strategies (root dry mass, height, basal diameter, adventitious roots, lenticels, and leaf renewal) of 13 tree species from the Cerrado and Pantanal biomes of Brazil. After 56 days of simulated inundation and 56 days of post-inundation recovery, we found that all study species were able to survive on waterlogged soil and to recover after the flood, and they can be used to restore periodically flooded riparian forests within the new legal zone. Our study is particularly relevant, as climate change is expected to increase flooding. As environmental laws change and new areas get restored including those in artificially flooded areas, such as on banks of hydroelectric dams, the experimental approach introduced in this study should be replicated with other species from various phytogeographic domains worldwide.     

A modified pH drift assay for inorganic carbon accumulation and external carbonic anhydrase activity in microalgae

Threat of global warming due to carbon dioxide (CO₂) emissions has stimulated research into carbon sequestration and emissions reduction technologies. Alkaline scrubbing allows CO₂ to be captured as bicarbonate, which can be photochemically fixed by microalgae. The carbon concentrating mechanism (CCM), of which external carbonic anhydrase is a key component, allows organisms to utilise this bicarbonate. In order to select a suitable strain for this application, a screening tool is required. The current method for determining carbonic anhydrase activity, the Wilbur and Anderson assay, was found to be unsuitable as a screening tool as the associated error was unacceptably large and tests on whole cells were inconclusive. This paper presents the development of a new, whole cell assay to measure inorganic carbon uptake and external carbonic anhydrase activity, based on classical pH drift experiments. Spirulina platensis was successfully used to develop a correlation between the specific carbon uptake (C) and the specific pH change (dpH). The relationship is described by the following: C[mmol C (g dry algae)^?1?h^?1]?=?0.064?×?(dpH). Inhibitor and salt dissociation tests validated the activity and presence of external carbonic anhydrase and allowed correlation between the Wilbur and Anderson assay and the new whole cell assay. Screening tests were conducted on S. platensis, Scenedesmus sp., Chlorella vulgaris and Dunaliella salina that were found to have carbon uptake rates of 5.76, 5.86, 3.86 and 2.15 mmol C (g dry algae)^?1?h^?1, respectively. These results corresponded to the species' known bicarbonate utilisation abilities and validated the use of the assay as a screening tool.     

Lipid‐Labeling Facilitates a Novel Magnetic Isolation Procedure to Characterize Pathogen‐Containing Phagosomes

Here we describe a novel approach for the isolation and biochemical characterization of pathogen‐containing compartments from primary cells: We developed a lipid‐based procedure to magnetically label the surface of bacteria and visualized the label by scanning and transmission electron microscopy (SEM, TEM). We performed infection experiments with magnetically labeled Mycobacterium avium, M. tuberculosis and Listeria monocytogenes and isolated magnetic bacteria‐containing phagosomes using a strong magnetic field in a novel free‐flow system. Magnetic labeling of M. tuberculosis did not affect the virulence characteristics of the bacteria during infection experiments addressing host cell activation, phagosome maturation delay and replication in macrophages in vitro. Biochemical analyses of the magnetic phagosome‐containing fractions provided evidence of an enhanced presence of bacterial antigens and a differential distribution of proteins involved in the endocytic pathway over time as well as cytokine‐dependent changes in the phagosomal protein composition. The newly developed method represents a useful approach to characterize and compare pathogen‐containing compartments, in order to identify microbial and host cell targets for novel anti‐infective strategies.     

Macrophytes in the Upper Paraná River floodplain: checklist and comparison with other large South American wetlands

Neotropical aquatic ecosystems have a rich aquatic flora. In this report, we have listed the aquatic flora of various habitats of the upper Paraná River floodplain by compiling data from literature and records of our own continuous collections conducted during the period 2007-2009. Our main purposes were to assess the macrophyte richness in the Paraná floodplain, to compare it with other South American wetlands and to assess whether the number of species recorded in South American inventories has already reached an asymptote. We recorded a total of 153 species of macrophytes in the Upper Paraná River floodplain, belonging to 100 genera and 47 families. In our comparative analysis, a clear floristic split from other South American wetlands was shown, except for the Pantanal, which is the closest wetland to the Paraná floodplain and, therefore, could be considered a floristic extension of the Pantanal. The species accumulation curve provides evidence that sampling efforts should be reinforced in order to compile a macrophyte flora census for South America. The high dissimilarity among South American wetlands, together with the lack of an asymptote in our species accumulation curve, indicates that the sampling effort needs to be increased to account for the actual species richness of macrophytes in this region.     

Vitamin E analog modulates UVB-induced signaling pathway activation and enhances cell survival

We have recently shown that exposure of human keratinocytes to physiologic doses of ultraviolet B (UVB) activates epidermal growth factor receptor (EGFR)/extracellular-regulated kinases 1 and 2 (ERK1/2) and p38 signaling pathways via reactive oxygen species, an effect that can be modulated by antioxidants. Trolox, a water-soluble vitamin E analog, is among the antioxidants that are currently being investigated for their preventive and protective potential against harmful effects of UV radiation to the skin. We found that Trolox inhibits both basal and UVB-induced intracellular H(2)O(2) generation in primary keratinocytes in a concentration-dependent manner. Trolox did not significantly affect UVB-induced phosphorylation of EGFR. Stronger inhibition was observed for ERK1/2 activation at lower, and for p38 activation at higher, concentrations of Trolox added to cells before exposure to UVB. Similarly different effects were found with regard to length of pretreatment with Trolox before UVB exposure-increasing inhibition for ERK1/2 activation at shorter, and for p38 activation at longer, pretreatment intervals. UVB-induced c-jun-N-terminal kinase activation was potently suppressed by Trolox. Also, increasing the pretreatment time of Trolox decreased the rate of cell death following UVB. In conclusion, UVB-induced signaling pathway activation is differentially modulated by Trolox. Further investigation into the time-dependent biologic activation of Trolox and its metabolic products, and modulation of signal transduction with cell outcome should facilitate development of rational strategies for pharmacologic applications.