Different reactions of central and marginal provenances of Fagus sylvatica to experimental drought

Climate extremes are expected to increase in frequency and magnitude as a consequence of global warming, threatening the functioning, services and goods of forest ecosystems. Across Europe, the ecologically and economically important tree species Fagus sylvatica is expected to suffer particularly under such conditions. The regional introduction of provenances from drier and warmer climates is one option to adapt beech forest ecosystems to these adverse effects of climate change. Marginal populations from the drought-prone southern and north-eastern edges of the species’ distribution come into focus in search of suitable candidates for Central European deciduous forests. Here, we test three marginal provenances (Spain, Bulgaria and Poland) and three provenances from the centre of the distribution range (Germany) for their response to drought in two different soil types (sand, loam) in a full factorial common garden experiment in Landau, Germany. Drought impacted all growth parameters negatively (leaf damage +22 % (percentage points), height ?40 % and diameter increment ?41 %), and the sandy substrate exacerbated this effect. However, provenances differed in their response to drought and soil type. Evidence for a local adaptation to summer drought was detected, especially in terms of mortality rates. The Bulgarian and Spanish provenance showed a stable performance under drought conditions (BG ?27 % in diameter increment; ES ?32 %), compared to the Polish (?48 %) or the most sensitive German provenances (?57 %), yet for Bulgaria on a low level of total increment. This may indicate a trade-off between drought tolerance and growth. Therefore, a sole focus on drought-resistant marginal provenances seems to not be conducive, as they might be less adapted to other climatic factors, e.g. frost, as well. However, intermixed with local Central European provenances, these may act as functional insurance in future drought-prone forest stands.     

Guideline for the description of soils in the Berlin metropolitan area: an extension for surveying and mapping anthropogenic and natural soils in urban environments within the German soil classification system

Journal of Soils and Sediments - In urban areas, humans shape the surface, (re-)deposit natural or technogenic material, and thus become the dominant soil formation factor. The 2015 edition of the...     

Autoantibodies against structures of the central nervous system in steroid responsive meningitis-arteriitis in dogs

Steroid-responsive meningitis-arteriitis (SRMA) is a disease of dogs familiar in small animal practice for decades. A combined evaluation of IgA in serum and cerebrospinal fluid (CSF) is an important diagnostic tool. It is suspected that immunpathological mechanisms are involved in the pathogenesis of SRMA because of the marked response to steroids. Excessive production of IgA seems to play a central role and might be caused by an immune reaction to self-antigens of the central nervous system (CNS). To test this hypothesis, we analyzed CSF samples from 55 dogs with SRMA using the western blot method. After blotting canine brain tissue, IgA, IgM and IgG of the CSF samples were tested for their binding to CNS antigens. We also evaluated CSF samples from 45 dogs with other brain diseases, including different encephalitides and intracranial tumors, and from healthy dogs as controls. Positive reactions (mostly IgA) were observed in the CSF samples from dogs with SRMA, different encephalitides and brain tumors (a total of 8% positive samples). The occurrence of autoantibodies against CNS structures was significantly higher in the control group "other brain diseases" than in the SRMA group (p = 0.0135). There was no significant difference in the number of positive samples between dogs with SRMA and the negative control group (healthy dogs, p = 0.1535). Despite the small number of positive samples, only dogs with abnormal findings in the CSF analysis also had autoantibodies in the CSF. There was no significant correlation between the occurrence of autoantibodies and levels of IgA, protein content and cell counts in the cerebrospinal fluid. However, there was a certain trend toward positive reactions in CSF samples with high protein content. The occurrence of autoantibodies in dogs with SRMA thus seems to be an epiphenomenona rather than the cause of the disease.     

The potential exceptional role of a small Baltic boulder reef as a solitary habitat in a sea of mud

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Pseudo-total antimony content in topsoils of the Berlin Metropolitan Area

Journal of Soils and Sediments - Sb is a metalloid that naturally occurs in traces in the Northern German Lowland Area, only. Its frequent and still growing demand for industrial purposes and its...     

Extrafollicular activation of lymph node B cells by antigen-bearing dendritic cells

In contrast to na?ve T cells that recognize short antigen-derived peptides displayed by specialized antigen-presenting cells, immunoglobulin receptors of B lymphocytes primarily recognize intact proteins. How and where within a lymph node such unprocessed antigens become available for na?ve B cell recognition is not clear. We used two-photon intravital imaging to show that, after exiting high-endothelial venules and before entry into lymph node follicles, B cells survey locally concentrated dendritic cells. Engagement of the B cell receptor by the dendritic cell (DC)-associated antigen leads to lymphocyte calcium signaling, migration arrest, antigen acquisition, and extrafollicular accumulation. These findings suggest a possible role for antigen-specific B-DC interactions in promoting T cell-dependent antibody responses in vivo.     

In vivo imaging reveals an essential role for neutrophils in leishmaniasis transmitted by sand flies

Infection with the obligate intracellular protozoan Leishmania is thought to be initiated by direct parasitization of macrophages, but the early events following transmission to the skin by vector sand flies have been difficult to examine directly. Using dynamic intravital microscopy and flow cytometry, we observed a rapid and sustained neutrophilic infiltrate at localized sand fly bite sites. Invading neutrophils efficiently captured Leishmania major (L.m.) parasites early after sand fly transmission or needle inoculation, but phagocytosed L.m. remained viable and infected neutrophils efficiently initiated infection. Furthermore, neutrophil depletion reduced, rather than enhanced, the ability of parasites to establish productive infections. Thus, L.m. appears to have evolved to both evade and exploit the innate host response to sand fly bite in order to establish and promote disease.     

Purification of the phospholipase D of Corynebacterium pseudotuberculosis by recycling isoelectric focusing

Recycling isoelectric focusing was investigated as a method for purification of phospholipase D (PLD) from cultures of Corynebacterium pseudotuberculosis. Supernatant fluids from cultures of equine isolate 155 in brain-heart infusion broth were dialyzed against distilled water, concentrated by lyophilization, and fractionated by preparative isoelectric focusing in free solution in a pH 3 to 13 gradient with 6M urea. Protein concentration, pH, and PLD activity of the 10 resulting fractions were determined. Two PLD activity assays were used: release of 14C choline from labeled sphingomyelin and synergistic hemolytic activity with Rhodococcus equi factors. Enzyme activity focused in 2 fractions at pH 8.5 to 9.8. The synergistic hemolytic assay was simple and rapid for detecting PLD in partially purified fractions. Electrophoretic examination of the fraction containing the highest concentration of PLD activity revealed protein bands at 14, 21, and 31.7 kD Mr, suggesting purification to near-homogeneity. Proteins from the 31.7-kD band were labeled by antibodies in serum from a goat with chronic C pseudotuberculosis infection.