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525 search hits
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Camellia sinensis – Tee (Theaceae), ein Heißgetränk nicht nur für kalte Wintertage
(2012)
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Hilke Steinecke
- Schwarzer Tee ist ein weltweit verbreitetes Genussmittelgetränk. Es wird aus den Blättern der Teepflanze (Camellia sinensis, Theaceae) gewonnen. Genutzt werden die beiden Varietäten assamica (Assam-Tee) und sinensis (China-Tee). Zur etwa 600 Arten umfassenden Familie der Teegewächse gehört auch die Kamelie (Camellia japonica), die in vielen Sorten und Hybriden eine hochwertige Zierpflanze für Haus und Garten darstellt. Tee und Kamelien sehen sich im nicht blühenden Zustand sehr ähnlich (vgl. DÖRKEN & JAGEL 2011). Das führte einst zu einer folgenschweren Verwechslung.
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Das Herbarium Adolf Becker im Pfarrarchiv Ober-Widdersheim
(2012)
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Stefan Dressler
Thomas Gregor
- Das Herbarium des Pfarrers Adolf Becker, gesammelt zwischen 1833 und 1863, wurde nachbestimmt. Bei der Mehrzahl der etwa 200 mit Fundorten versehenen Belege handelt es sich um Kulturpflanzen, die vornehmlich in Parkanlagen von Bad Homburg v. d. Höhe und Okarben gesammelt wurden. Diese geben einen Eindruck von den erstaunlich reichhaltigen Bepflanzungen jener Zeit. 81 von uns als Wildpflanzen klassifizierte Arten wurden zumeist um Okarben gesammelt. Wegen ihres Rückganges oder aktuellen Fehlens sind die Belege von Apium graveolens, A. nodiflorum, Juncus gerardii, Nigella arvensis und Oenanthe fistulosa bemerkenswert.
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Genetic and functional analyses of SHANK2 mutations suggest a multiple hit model of autism spectrum disorders
(2012)
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Claire S. Leblond
Jutta Heinrich
Richard Delorme
Christian Proepper
Catalina Betancur
Guillaume Huguet
Marina Konyukh
Pauline Chaste
Elodie Ey
Maria Rastam
Henrik Anckarsäter
Gudrun Nygren
I. Carina Gillberg
Jonas Melke
Roberto Toro
Beatrice Regnault
Fabien Fauchereau
Oriane Mercati
Nathalie Lemière
David Skuse
Martin Poot
Richard Holt
Anthony P. Monaco
Irma Järvelä
Katri Kantojärvi
Raija Vanhala
Sarah Curran
David A. Collier
Patrick Bolton
Andreas Chiocchetti
Sabine M. Klauck
Fritz Poustka
Christine M. Freitag
Regina Waltes
Marnie Kopp
Eftichia Duketis
Elena Bacchelli
Fiorella Minopoli
Liliana Ruta
Agatino Battaglia
Luigi Mazzone
Elena Maestrini
Ana F. Sequeira
Barbara Oliveira
Astrid Vicente
Guiomar Oliveira
Dalila Pinto
Stephen W. Scherer
Diana Zelenika
Marc Delepine
Mark Lathrop
Dominique Bonneau
Vincent Guinchat
Françoise Devillard
Brigitte Assouline
Marie-Christine Mouren
Marion Leboyer
Christopher Gillberg
Tobias M. Boeckers
Thomas Bourgeron
- Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While many rare variants in synaptic proteins have been identified in patients with ASD, little is known about their effects at the synapse and their interactions with other genetic variations. Here, following the discovery of two de novo SHANK2 deletions by the Autism Genome Project, we identified a novel 421 kb de novo SHANK2 deletion in a patient with autism. We then sequenced SHANK2 in 455 patients with ASD and 431 controls and integrated these results with those reported by Berkel et al. 2010 (n = 396 patients and n = 659 controls). We observed a significant enrichment of variants affecting conserved amino acids in 29 of 851 (3.4%) patients and in 16 of 1,090 (1.5%) controls (P = 0.004, OR = 2.37, 95% CI = 1.23-4.70). In neuronal cell cultures, the variants identified in patients were associated with a reduced synaptic density at dendrites compared to the variants only detected in controls (P = 0.0013). Interestingly, the three patients with de novo SHANK2 deletions also carried inherited CNVs at 15q11-q13 previously associated with neuropsychiatric disorders. In two cases, the nicotinic receptor CHRNA7 was duplicated and in one case the synaptic translation repressor CYFIP1 was deleted. These results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the "multiple hit model" for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD.
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Atomic-Level Structure Characterization of an Ultrafast Folding Mini-Protein Denatured State
(2012)
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Per Rogne
Przemysław Ozdowy
Christian Richter
Krishna Saxena
Harald Schwalbe
Lars T. Kuhn
- Atomic-level analyses of non-native protein ensembles constitute an important aspect of protein folding studies to reach a more complete understanding of how proteins attain their native form exhibiting biological activity. Previously, formation of hydrophobic clusters in the 6 M urea-denatured state of an ultrafast folding mini-protein known as TC5b from both photo-CIDNP NOE transfer studies and FCS measurements was observed. Here, we elucidate the structural properties of this mini-protein denatured in 6 M urea performing 15N NMR relaxation studies together with a thorough NOE analysis. Even though our results demonstrate that no elements of secondary structure persist in the denatured state, the heterogeneous distribution of R2 rate constants together with observing pronounced heteronuclear NOEs along the peptide backbone reveals specific regions of urea-denatured TC5b exhibiting a high degree of structural rigidity more frequently observed for native proteins. The data are complemented with studies on two TC5b point mutants to verify the importance of hydrophobic interactions for fast folding. Our results corroborate earlier findings of a hydrophobic cluster present in urea-denatured TC5b comprising both native and non-native contacts underscoring their importance for ultra rapid folding. The data assist in finding ways of interpreting the effects of pre-existing native and/or non-native interactions on the ultrafast folding of proteins; a fact, which might have to be considered when defining the starting conditions for molecular dynamics simulation studies of protein folding.
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Hypoxia-induced alternative splicing in endothelial cells
(2012)
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Julia E. Weigand
Jes-Niels Boeckel
Pascal Gellert
Stefanie Dimmeler
- BACKGROUND: Adaptation to low oxygen by changing gene expression is vitally important for cell survival and tissue development. The sprouting of new blood vessels, initiated from endothelial cells, restores the oxygen supply of ischemic tissues. In contrast to the transcriptional response induced by hypoxia, which is mainly mediated by members of the HIF family, there are only few studies investigating alternative splicing events. Therefore, we performed an exon array for the genome-wide analysis of hypoxia-related changes of alternative splicing in endothelial cells.
METHODOLOGY/PRINCIPAL FINDINGS: Human umbilical vein endothelial cells (HUVECs) were incubated under hypoxic conditions (1% O(2)) for 48 h. Genome-wide transcript and exon expression levels were assessed using the Affymetrix GeneChip Human Exon 1.0 ST Array. We found altered expression of 294 genes after hypoxia treatment. Upregulated genes are highly enriched in glucose metabolism and angiogenesis related processes, whereas downregulated genes are mainly connected to cell cycle and DNA repair. Thus, gene expression patterns recapitulate known adaptations to low oxygen supply. Alternative splicing events, until now not related to hypoxia, are shown for nine genes: six which are implicated in angiogenesis-mediated cytoskeleton remodeling (cask, itsn1, larp6, sptan1, tpm1 and robo1); one, which is involved in the synthesis of membrane-anchors (pign) and two universal regulators of gene expression (cugbp1 and max).
CONCLUSIONS/SIGNIFICANCE: For the first time, this study investigates changes in splicing in the physiological response to hypoxia on a genome-wide scale. Nine alternative splicing events, until now not related to hypoxia, are reported, considerably expanding the information on splicing changes due to low oxygen supply. Therefore, this study provides further knowledge on hypoxia induced gene expression changes and presents new starting points to study the hypoxia adaptation of endothelial cells.
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Dealing with Varying Detection Probability, Unequal Sample Sizes and Clumped Distributions in Count Data
(2012)
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D. Johan Kotze
Robert B. O'Hara
Susanna Lehvävirta
- Temporal variation in the detectability of a species can bias estimates of relative abundance if not handled correctly. For example, when effort varies in space and/or time it becomes necessary to take variation in detectability into account when data are analyzed. We demonstrate the importance of incorporating seasonality into the analysis of data with unequal sample sizes due to lost traps at a particular density of a species. A case study of count data was simulated using a spring-active carabid beetle. Traps were ‘lost’ randomly during high beetle activity in high abundance sites and during low beetle activity in low abundance sites. Five different models were fitted to datasets with different levels of loss. If sample sizes were unequal and a seasonality variable was not included in models that assumed the number of individuals was log-normally distributed, the models severely under- or overestimated the true effect size. Results did not improve when seasonality and number of trapping days were included in these models as offset terms, but only performed well when the response variable was specified as following a negative binomial distribution. Finally, if seasonal variation of a species is unknown, which is often the case, seasonality can be added as a free factor, resulting in well-performing negative binomial models. Based on these results we recommend (a) add sampling effort (number of trapping days in our example) to the models as an offset term, (b) if precise information is available on seasonal variation in detectability of a study object, add seasonality to the models as an offset term; (c) if information on seasonal variation in detectability is inadequate, add seasonality as a free factor; and (d) specify the response variable of count data as following a negative binomial or over-dispersed Poisson distribution.
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No influence of dabigatran anticoagulation on hemorrhagic transformation in an experimental model of ischemic stroke
(2012)
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Ferdinand Bohmann
Ana Mirceska
Josef Martin Pfeilschifter
Edelgard Lindhoff-Last
Helmuth Steinmetz
Christian Foerch
Waltraud Pfeilschifter
- Background: Dabigatran etexilate (DE) is a new oral direct thrombin inhibitor. Clinical trials point towards a favourable risk-to-benefit profile of DE compared to warfarin. In this study, we evaluated whether hemorrhagic transformation (HT) occurs after experimental stroke under DE treatment as we have shown for warfarin.
Methods: 44 male C57BL/6 mice were pretreated orally with 37.5 mg/kg DE, 75 mg/kg DE or saline and diluted thrombin time (dTT) and DE plasma concentrations were monitored. Ischemic stroke was induced by transient middle cerebral artery occlusion (tMCAO) for 1 h or 3 h. We assessed functional outcome and HT blood volume 24 h and 72 h after tMCAO.
Results: After 1 h tMCAO, HT blood volume did not differ significantly between mice pretreated with DE 37.5 mg/kg and controls (1.5±0.5 µl vs. 1.8±0.5 µl, p>0.05). After 3 h tMCAO, DE-anticoagulated mice did also not show an increase in HT, neither at the dose of 37.5 mg/kg equivalent to anticoagulant treatment in the therapeutic range (1.3±0.9 µl vs. control 2.3±0.5 µl, p>0.05) nor at 75 mg/kg, clearly representing supratherapeutic anticoagulation (1.8±0.8 µl, p>0.05). Furthermore, no significant increase in HT under continued anticoagulation with DE 75 mg/kg could be found at 72 h after tMCAO for 1 h (1.7±0.9 µl vs. control 1.6±0.4 µl, p>0.05).
Conclusion: Our experimental data suggest that DE does not significantly increase hemorrhagic transformation after transient focal cerebral ischemia in mice. From a translational viewpoint, this indicates that a continuation of DE anticoagulation in case of an ischemic stroke might be safe, but clearly, clinical data on this question are warranted.
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Diversity and Distribution Patterns in High Southern Latitude Sponges
(2012)
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Rachel V. Downey
Huw J. Griffiths
Katrin Linse
Dorte Janussen
- Sponges play a key role in Antarctic marine benthic community structure and dynamics and are often a dominant component of many Southern Ocean benthic communities. Understanding the drivers of sponge distribution in Antarctica enables us to understand many of general benthic biodiversity patterns in the region. The sponges of the Antarctic and neighbouring oceanographic regions were assessed for species richness and biogeographic patterns using over 8,800 distribution records. Species-rich regions include the Antarctic Peninsula, South Shetland Islands, South Georgia, Eastern Weddell Sea, Kerguelen Plateau, Falkland Islands and north New Zealand. Sampling intensity varied greatly within the study area, with sampling hotspots found at the Antarctic Peninsula, South Georgia, north New Zealand and Tierra del Fuego, with limited sampling in the Bellingshausen and Amundsen seas in the Southern Ocean. In contrast to previous studies we found that eurybathy and circumpolar distributions are important but not dominant characteristics in Antarctic sponges. Overall Antarctic sponge species endemism is ~43%, with a higher level for the class Hexactinellida (68%). Endemism levels are lower than previous estimates, but still indicate the importance of the Polar Front in isolating the Southern Ocean fauna. Nineteen distinct sponge distribution patterns were found, ranging from regional endemics to cosmopolitan species. A single, distinct Antarctic demosponge fauna is found to encompass all areas within the Polar Front, and the sub-Antarctic regions of the Kerguelen Plateau and Macquarie Island. Biogeographical analyses indicate stronger faunal links between Antarctica and South America, with little evidence of links between Antarctica and South Africa, Southern Australia or New Zealand. We conclude that the biogeographic and species distribution patterns observed are largely driven by the Antarctic Circumpolar Current and the timing of past continent connectivity.
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Time-Resolved Influences of Functional DAT1 and COMT Variants on Visual Perception and Post-Processing
(2012)
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Stephan Bender
Thomas Rellum
Christine M. Freitag
Franz Resch
Marcella Rietschel
Jens Treutlein
Christine Jennen-Steinmetz
Daniel Brandeis
Tobias Banaschewski
Manfred Laucht
- Background: Dopamine plays an important role in orienting and the regulation of selective attention to relevant stimulus characteristics. Thus, we examined the influences of functional variants related to dopamine inactivation in the dopamine transporter (DAT1) and catechol-O-methyltransferase genes (COMT) on the time-course of visual processing in a contingent negative variation (CNV) task.
Methods: 64-channel EEG recordings were obtained from 195 healthy adolescents of a community-based sample during a continuous performance task (A-X version). Early and late CNV as well as preceding visual evoked potential components were assessed.
Results: Significant additive main effects of DAT1 and COMT on the occipito-temporal early CNV were observed. In addition, there was a trend towards an interaction between the two polymorphisms. Source analysis showed early CNV generators in the ventral visual stream and in frontal regions. There was a strong negative correlation between occipito-temporal visual post-processing and the frontal early CNV component. The early CNV time interval 500–1000 ms after the visual cue was specifically affected while the preceding visual perception stages were not influenced.
Conclusions: Late visual potentials allow the genomic imaging of dopamine inactivation effects on visual post-processing. The same specific time-interval has been found to be affected by DAT1 and COMT during motor post-processing but not motor preparation. We propose the hypothesis that similar dopaminergic mechanisms modulate working memory encoding in both the visual and motor and perhaps other systems.
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Aging in place in late life: theory, methodology, and intervention
(2012)
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Agneta Malmgren Fänge
Frank Oswald
Lindy Clemson
- Editorial: This special issue focuses on aging in place in late life. Aging in place is about being able to continue living in one’s own home or neighborhood and to adapt to changing needs and conditions. It is of high concern due to the increasing number of old and very old people in all societies and challenges researchers, practitioners, and policy makers in many societal and scientific areas and disciplines. We invited authors to contribute original research papers as well as conceptually driven review papers that would stimulate the continuing efforts to understand the different aspects of aging in place in late life. The papers that were submitted came from very diverse disciplines, such as sociology, psychology, occupational therapy, nursing, architecture, public planning, and social work. Given the number and diversity of papers submitted, we can conclude that aging in place is an important concern throughout the world and that different kinds of measures are taken to come up with local, national, and international solutions that enhance aging in place. It remains a very complex issue that needs and deserves to be investigated from many different perspectives and assessed by means of different methodological origin, covering qualitative and quantitative measures, as well as mixed-method approaches. Subsequently, the selection of papers presented in this issue only sheds light on some aspects of sociophysical person-environment exchange as people age, contributing to the ongoing discussion in the field of environmental gerontology...