Potential distribution and environmental threat of <Emphasis Type=Italic>Pueraria lobata</Emphasis>

Pueraria lobata (kudzu) is an invasive weed originating from East Asia. Local infestations have been recently observed in Switzerland and northern Italy; however, the potential for P. lobata to spread and to become abundant and damaging in the Alpine countries is not known. The aim of this study was to project the potential distribution of P. lobata under current climate in Switzerland, Austria and Slovenia and parts of northern Italy using the ecoclimatic model CLIMEX. In addition, areas at risk were identified where P. lobata may occur as a strong and aggressive competitor. This was derived from the plants’ distribution and climatic requirements in the south-eastern United States where the heaviest infestations occur. Projections show that 60.84% of the total land area of northern Italy, followed by 47.08% of Slovenia, 21.01% of Austria and only 1.97% of Switzerland are climatically suitable. P. lobata may become a troublesome weed due to very favourable climatic conditions only in some parts of northern Italy and Slovenia. In climatically suitable areas, any occurrence of the plant should be carefully observed. In infested and highly climatically suitable areas, there is a need for strategic management to prevent further spread of P. lobata.     

Impaired GABAergic transmission and altered hippocampal synaptic plasticity in collybistin-deficient mice

Collybistin (Cb) is a brain-specific guanine nucleotide exchange factor that has been implicated in plasma membrane targeting of the postsynaptic scaffolding protein gephyrin found at glycinergic and GABAergic synapses. Here we show that Cb-deficient mice display a region-specific loss of postsynaptic gephyrin and GABA(A) receptor clusters in the hippocampus and the basolateral amygdala. Cb deficiency is accompanied by significant changes in hippocampal synaptic plasticity, due to reduced dendritic GABAergic inhibition. Long-term potentiation is enhanced, and long-term depression reduced, in Cb-deficient hippocampal slices. Consistent with the anatomical and electrophysiological findings, the animals show increased levels of anxiety and impaired spatial learning. Together, our data indicate that Cb is essential for gephyrin-dependent clustering of a specific set of GABA(A) receptors, but not required for glycine receptor postsynaptic localization.     

CT-Based Attenuation Correction in I-123-Ioflupane SPECT

Purpose

Attenuation correction (AC) based on low-dose computed tomography (CT) could be more accurate in brain single-photon emission computed tomography (SPECT) than the widely used Chang method, and, therefore, has the potential to improve both semi-quantitative analysis and visual image interpretation. The present study evaluated CT-based AC for dopamine transporter SPECT with I-123-ioflupane.

Materials and methods

Sixty-two consecutive patients in whom I-123-ioflupane SPECT including low-dose CT had been performed were recruited retrospectively at 3 centres. For each patient, 3 different SPECT images were reconstructed: without AC, with Chang AC and with CT-based AC. Distribution volume ratio (DVR) images were obtained by scaling voxel intensities using the whole brain without striata as reference. For assessing the impact of AC on semi-quantitative analysis, specific-to-background ratios (SBR) in caudate and putamen were obtained by fully automated SPM8-based region of interest (ROI) analysis and tested for their diagnostic power using receiver-operator-characteristic (ROC) analysis. For assessing the impact of AC on visual image reading, screenshots of stereotactically normalized DVR images presented in randomized order were interpreted independently by two raters at each centre.

Results

CT-based AC resulted in intermediate SBRs about half way between no AC and Chang. Maximum area under the ROC curve was achieved by the putamen SBR, with negligible impact of AC (0.924, 0.935 and 0.938 for no, CT-based and Chang AC). Diagnostic accuracy of visual interpretation also did not depend on AC.

Conclusions

The impact of CT-based versus Chang AC on the interpretation of I-123-ioflupane SPECT is negligible. Therefore, CT-based AC cannot be recommended for routine use in clinical patient care, not least because of the additional radiation exposure.     

Ubiquitin initiates sorting of Golgi and plasma membrane proteins into the vacuolar degradation pathway

ABSTRACT: BACKGROUND: In yeast and mammals, many plasma membrane (PM) proteins destined for degradation are tagged with ubiquitin. These ubiquitinated proteins are internalized into clathrin-coated vesicles and are transported to early endosomal compartments. There, ubiquitinated proteins are sorted by the endosomal sorting complex required for transport (ESCRT) machinery into the intraluminal vesicles of multivesicular endosomes. Degradation of these proteins occurs after endosomes fuse with lysosomes/lytic vacuoles to release their content into the lumen. In plants, some PM proteins, which cycle between the PM and endosomal compartments, have been found to be ubiquitinated, but it is unclear whether ubiquitin is sufficient to mediate internalization and thus acts as a primary sorting signal for the endocytic pathway. To test whether plants use ubiquitin as a signal for the degradation of membrane proteins, we have translationally fused ubiquitin to different fluorescent reporters for the plasma membrane and analyzed their transport. RESULTS: Ubiquitin-tagged PM reporters localized to endosomes and to the lumen of the lytic vacuole in tobacco mesophyll protoplasts and in tobacco epidermal cells. The internalization of these reporters was significantly reduced if clathrin-mediated endocytosis was inhibited by the coexpression of a mutant of the clathrin heavy chain, the clathrin hub. Surprisingly, a ubiquitin-tagged reporter for the Golgi was also transported into the lumen of the vacuole. Vacuolar delivery of the reporters was abolished upon inhibition of the ESCRT machinery, indicating that the vacuolar delivery of these reporters occurs via the endocytic transport route. CONCLUSIONS: Ubiquitin acts as a sorting signal at different compartments in the endomembrane system to target membrane proteins into the vacuolar degradation pathway: If displayed at the PM, ubiquitin triggers internalization of PM reporters into the endocytic transport route, but it also mediates vacuolar delivery if displayed at the Golgi. In both cases, ubiquitin-tagged proteins travel via early endosomes and multivesicular bodies to the lytic vacuole. This suggests that vacuolar degradation of ubiquitinated proteins is not restricted to PM proteins but might also facilitate the turnover of membrane proteins in the early secretory pathway.     

Import and export of biological samples from tropical countries–considerations and guidelines for research teams

‘Biodiversity’ is increasingly perceived as an important resource for research and conservation, but also for economy. Conservation, access and sustainable use of biodiversity (genetic resources, species, samples) are negotiated on different political levels, resulting in an internationally binding legal framework. Resulting legislation is binding for all parties involved in biological sampling, i.e. researches and (and in italics) countries, and especially applies for tissue or DNA samples and dervied products thereof. Understanding and awareness of export and import permits for biological samples is increasingly important for biologists to perform research projects legally and timely. Nevertheless, some biologists are still exporting and importing biological samples ignoring or non-compliant with national and international legislation, conventions, and regulations. Resulting difficulties may not only cause serious problems during field work, but may also delay the export, import or exchange of samples. Comprehensive a priori information regarding legal requirements helps to avoid or at least diminish potential problems. We identified four major factors facilitating export/import permits: (1) good personal (mutually trusted) contacts in the country of origin, (2) understanding and compliance with all relevant laws and regulations; (3) access to information regarding knowledge on permits, regulations and laws including their circulation within the researcher communities; and (4) access to consistent and up to date regulations     

Induced plant volatiles allow sensitive monitoring of plant health status in greenhouses

A novel approach to support the inspection of greenhouse crops is based on the measurement of volatile organic compounds emitted by unhealthy plants.This approach has attracted some serious interest over the last decade. In pursuit of this interest, we performed several experiments at the laboratory-scale to pinpoint marker volatiles that can be used to indicate certain health problems. In addition to these laboratory experiments, pilot and model studies were performed in order to verify the validity of these marker volatiles under real-world conditions. This paper provides an overview of results and gives an outlook on the use of plant volatiles for plant health monitoring.Key words: plant health, volatiles, plant pathogens, plant infection     

Temporal Changes in Randomness of Bird Communities across Central Europe

Many studies have examined whether communities are structured by random or deterministic processes, and both are likely to play a role, but relatively few studies have attempted to quantify the degree of randomness in species composition. We quantified, for the first time, the degree of randomness in forest bird communities based on an analysis of spatial autocorrelation in three regions of Germany. The compositional dissimilarity between pairs of forest patches was regressed against the distance between them. We then calculated the y-intercept of the curve, i.e. the ‘nugget’, which represents the compositional dissimilarity at zero spatial distance. We therefore assume, following similar work on plant communities, that this represents the degree of randomness in species composition. We then analysed how the degree of randomness in community composition varied over time and with forest management intensity, which we expected to reduce the importance of random processes by increasing the strength of environmental drivers. We found that a high portion of the bird community composition could be explained by chance (overall mean of 0.63), implying that most of the variation in local bird community composition is driven by stochastic processes. Forest management intensity did not consistently affect the mean degree of randomness in community composition, perhaps because the bird communities were relatively insensitive to management intensity. We found a high temporal variation in the degree of randomness, which may indicate temporal variation in assembly processes and in the importance of key environmental drivers. We conclude that the degree of randomness in community composition should be considered in bird community studies, and the high values we find may indicate that bird community composition is relatively hard to predict at the regional scale.     

结核分枝杆菌可视化抗体检测蛋白芯片的制备

目的：利用克隆表达的7种结核分枝杆菌优势表位抗原,建立可视化抗体检测蛋白芯片,用于结核病辅助诊断。方法：将7种结核分枝杆菌优势表位抗原,即38kD、ESAT-6、CFP10、MPT64、Mtb8、Mtb8.4和Mtb16.3点于修饰的基片上,制备可检测7种结核抗体的多靶点蛋白微阵列,建立免疫金银染色检测系统;使用该芯片对48例临床结核病患者血液样品进行检测,并与“金标准”痰涂片（48例）和痰培养（其中的29例）检测结果进行比较,分析其敏感性;对30名献血员血液样品进行检测,分析其特异性。结果：可视化抗体检测蛋白芯片的敏感性分别为98.5％和96.6％,而痰涂片和痰培养检测方法的敏感性分别为35.4％和48.3％;可视化抗体检测蛋白芯片的特异性为93.3％。结论：建立的结核分枝杆菌可视化抗体检测蛋白芯片检测敏感性显著高于痰涂片和痰培养方法,可用于结核病的临床辅助诊断,提高痰涂片和痰培养假阴性的检出率。     

Seeds of Arabidopsis plants expressing dominant-negative AtSKD1 under control of the GL2 promoter show a transparent testa phenotype and a mucilage defect

We have recently shown that overexpression of dominant-negative AtSKD1 versions under control of the trichome and non-root-hair-cell specific GL2 promoter (GL2_pro) blocks trafficking of soluble cargo to the vacuole, resulting in its fragmentation and ultimately cell death. GL2_pro is also active in the Arabidopsis seeds. When we inspected seeds of the dominant-negative AtSKD1 variants we found two phenotypes. The seeds display a transparent testa phenotype caused by a lack of proanthocyanidin (PA) and do not possess seed coat mucilage. Both phenotypes could be connected by cell death induced by the overexpression of dominant-negative AtSKD1.Key words: VPS4, ESCRT, plant, Arabidopsis, SKD1, ATPase, MVB, proanthocyanidin, transparent testa, mucilage, tannin, seed coat, AtSKD1AAA ATPases are important regulators of a plethora of cellular functions such as peroxisome biogenesis, vesicle-mediated transport, control of cell divisions and gene expression. This variety is based on a common mechanism, the energy dependent unfolding, remodeling and disassembly of proteins and protein complexes.¹Mammalian SKD1 and its yeast homolog VPS4 are AAA ATPases involved in the sorting of monoubiquitylated trans-membrane cargo to the lysosome/vacuole by dismantling the members of the endosomal sorting complex required for transport (ESCRT) complexes from the endosomal membrane.² The Arabidopsis SKD1 homolog, AtSKD1, has been characterized recently and has been shown to be an ortholog of SKD1/Vps4.^3,4 Mutations for all three ATPases are known that alone or in combination render them dominant-negative.^3–6 Overexpression of dominant-negative AtSKD1 is, however, lethal for Arabidopsis plants. Therefore, we have used the trichome and non-root-hair-cell-specific GL2_pro promoter to address the function of AtSKD1 in planta. Cells that express the dominant-negative versions show multiple nuclei, fragmented vacuoles and ultimately die. These phenotypes are most likely due to a block in vacuolar trafficking of soluble cargo that is instead secreted.⁴GL2_pro is also active in the coat of developing Arabidopsis seeds. We therefore inspected seeds of lines overexpressing dominant-negative and wild-type AtSKD1.     

Land use intensification alters ecosystem multifunctionality via loss of biodiversity and changes to functional composition

Global change, especially land‐use intensification, affects human well‐being by impacting the delivery of multiple ecosystem services (multifunctionality). However, whether biodiversity loss is a major component of global change effects on multifunctionality in real‐world ecosystems, as in experimental ones, remains unclear. Therefore, we assessed biodiversity, functional composition and 14 ecosystem services on 150 agricultural grasslands differing in land‐use intensity. We also introduce five multifunctionality measures in which ecosystem services were weighted according to realistic land‐use objectives. We found that indirect land‐use effects, i.e. those mediated by biodiversity loss and by changes to functional composition, were as strong as direct effects on average. Their strength varied with land‐use objectives and regional context. Biodiversity loss explained indirect effects in a region of intermediate productivity and was most damaging when land‐use objectives favoured supporting and cultural services. In contrast, functional composition shifts, towards fast‐growing plant species, strongly increased provisioning services in more inherently unproductive grasslands.