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Fluorescence lifetime imaging of molecular rotors to map microviscosity in cells

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Chinese Optics Letters 2010年第10期8卷 926-930页

作者： James A. Levitt Marina K. Kuimova Gokhan Yahioglu Pei-Hua Chung klaus Suhling David Phillips Department of Physics King's College London Department of Chemistry Imperial College London PhotoBiotics Ltd.

Fluorescence liftime imaging （FLIM） of modified hydrophobic bodipy dyes that act as fluorescent molecular rotors shows that the fluorescence lifetime of these probes is a function of the microviscosity of their environment. Incubating cells with these dyes, we find a punctate and continuous distribution of the dye in cells. The viscosity value obtained in what appears to be endocytotic vesicles in living cells is around 100 times higher than that of water and of cellular ***-resolved fluorescence anisotropy measurements also yield rotational correlation times consistent with large microviscosity values. In this way, we successfully develop a practical and versatile approach to map the microviscosity in cells based on imaging fluorescent molecular rotors.

关键词： Fluorescence lifetime imaging of molecular rotors to map microviscosity in cells

Structure and properties of Ni(110) surface coadsorbing chlorine and oxygen

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Science China Chemistry 1996年第5期39卷 553-560页

作者：庄叔贤季明荣吴建新屠兢方文秀俞爽英 klaus Wandelt Department of Chemical Physics and Structure Research Laboratory University of Science and Technology Institute of Physical Chemistry University of Bonn Wegelerstr. 12 D-53115 Bonn F. R. Germany

The coadsorption of chlorine with oxygen on Ni(110) surface has been investigated by XPS, UPS, AES and work function measurements. The chlorine preadsorption drastically inhibits the further uptake of oxygen. On the contrary, precovered oxygen has hardly any influence on the additional adsorption of chlorine due to the incorporation of precovered oxygen into the subsurface driven by the chlorine coadsorption. ARXPS measurements provide the evidence for this coadsorption model. The thermal desorption of chlorine and oxygen from the coadsorption surface is very similar to that of both individual adsorbates under the same heating conditions, but the desorption temperature of both the adsorbates apparently decreases on the coadsorption surface. The coadsorption and thermodesorption mechanisms are also discussed in detail.

关键词： coadsorption of chlorine with oxygen Ni(110) surface photoelectron spectroscopy.

Comprehensive Transcriptome Analysis of Auxin Responses in Arabidopsis

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Molecular Plant 2008年第2期1卷 321-337页

作者： Ivan A. Paponov Martina Paponovt William Teale Margit Menges Sohini Chakrabortee James A.H. Murray klaus Palme Faculty of Biology University of Freiburg Schanzlestrasse 1 79104 Freiburg Germany Institute of Biotechnology University of Cambridge Cambridge CB2 1QT United Kingdom

In plants, the hormone auxin shapes gene expression to regulate growth and development. Despite the detailed characterization of auxin-inducible genes, a comprehensive overview of the temporal and spatial dynamics of auxinregulated gene expression is lacking. Here, we analyze transcriptome data from many publicly available Arabidopsis profiling experiments and assess tissue-specific gene expression both in response to auxin concentration and exposure time and in relation to other plant growth regulators. Our analysis shows that the primary response to auxin over a wide range of auxin application conditions and in specific tissues comprises almost exclusively the up-regulation of genes and iden- tifies the most robust auxin marker genes. Tissue-specific auxin responses correlate with differential expression of Aux/ IAA genes and the subsequent regulation of context- and sequence-specific patterns of gene expression. Changes in transcript levels were consistent with a distinct sequence of conjugation, increased transport capacity and down-regulation of biosynthesis in the temperance of high cellular auxin concentrations. Our data show that auxin regulates genes associated with the biosynthesis, catabolism and signaling pathways of other phytohormones. We present a transcriptional overview of the auxin response. Specific interactions between auxin and other phytohormones are highlighted, particularly the regulation of their metabolism. Our analysis provides a roadmap for auxin-dependent processes that underpins the concept of an ＇auxin code＇-a tissue-specific fingerprint of gene expression that initiates specific developmental processes.

关键词： Alcohol Abstinence Genes transport capacity transcriptomics Tissue-Specific Gene Expression Auxins Arabidopsis Plant Growth Regulators

Loss of Aβ-nerve endings associated with the Merkel cell-neurite complex in the lesional oral mucosa epithelium of lichen planus and hyperkeratosis

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International Journal of Oral Science 2016年第1期8卷 32-38页

作者： Daniela Calderon Carrion Yiiksel Korkmaz Britta Cho Marion Kopp Wilhelm Bloch klaus Addicks Wilhelm Niedermeier Department of Prosthetic Dentistry Dental SchoolUniversity of CologneCologneGermany Center for Biochemistry Institute for Experimental Dental Research and Oral Musculoskeletal BiologyMedical FacultyUniversity of CologneCologneGermany Department of Anatomy University of CologneCologneGermany Department of Molecular and Cellular Sport Medicine German Sport UniversityCologneGermany

The Merkel cell-neurite complex initiates the perception of touch and mediates Ap slowly adapting type I responses. Lichen planus is a chronic inflammatory autoimmune disease with T-cell-mediated inflammation, whereas hyperkeratosis is characterized with or without epithelial dysplasia in the oral mucosa. To determine the effects of lichen planus and hyperkeratosis on the Merkel cell-neurite complex, healthy oral mucosal epithelium and lesional oral mucosal epithelium of lichen planus and hyperkeratosis patients were stained by immunohistochemistry （the avidin-biotin-peroxidase complex and double immunofluorescence methods）using pan cytokeratin, cytokeratin 20 （K20, a Merkel cell marker）, and neurofilament 200 （NF200, a myelinated Aβ- and Aδ-nerve fibre marker） antibodies. N F200-immunoreactive （ir） nerve fibres in healthy tissues and in the lesional oral mucosa epithelium of lichen planus and hyperkeratosis were counted and statistically analysed. In the healthy oral mucosa, K20-positive Merkel cells with and without close association to the intraepithelial NF200-ir nerve fibres were detected. In the lesional oral mucosa of lichen planus and hyperkeratosis patients, extremely rare NF200-ir nerve fibres were detected only in the lamina propria. Compared with healthy tissues, lichen planus and hyperkeratosis tissues had significantly decreased numbers of NF200-ir nerve fibres in the oral mucosal epithelium. Lichen planus and hyperkeratosis were associated with the absence of Aβ-nerve endings in the oral mucosal epithelium. Thus, we conclude that mechanosensation mediated by the Merkel cell-neurite complex in the oral mucosal epithelium is impaired in lichen planus and hvperkeratosis.

关键词： Aβ-nerve fibres hyperkeratosis lichen planus mechanosensation Merkel cell-neurite complex

Nutritional stress reduces flight performance and exploratory behavior in a butterfly

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Insect Science 2019年第5期26卷 897-910页

作者： Elisabeth Reim Danny Eichhorn Jan D.Roy Philip O.M.Steinhoff klaus Fischer Zoological Institute and Museum Greifswald UniversityGreifswaldGermany

Anthropogenic global change, including agricultural intensification and climate change, poses a substantial challenge to many herbivores due to a reduced availability of feeding resources. The concomitant food stress is expected to detrimentally affect performance, amongst others in dispersal-related traits. Thus, while dispersal is of utmost importance to escape from deteriorating habitat conditions, such conditions may negatively feedback on the ability to do so. Therefore, we here investigate the impact of larval and adult food stress on traits related to dispersal ability, including morphology, physiology, flight performance, and exploratory behavior, in a butterfly. We show that inadequate nutrition during development and in the adult stage dim inishes flight performance, despite som e reallocation of somatic resources. Detrimental effects of food stress on flight performance were mainly caused by reductions in body mass and storage reserves. Similar results were found for exploratory behavior. Furthermore, exploratory behavior was found to be (moderately) repeatable at the individual level, which might indicate the existence of a personality trait. This notion is further supported by the fact that flight performance and exploratory behavior were positively correlated, potentially suggesting the existence of a dispersal syndrome. In summary, our findings may have important implications for dispersal in natural environments, as the conditions requiring dispersal the m ost impair flight ability and thereby likely dispersal rates.

关键词： condition dispersal syndrome flight ability food stress habitat degradation resource allocation

Referential alarm calling behaviour in New World primates

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Current Zoology 2012年第5期58卷 680-697页

作者： Cristiane CASAR klaus ZUBERBOHLER Scottish Primate Research Group School of Psychology University of St Andrews. St Mary's Quad St Andrews Fife Scotland UK KY16 9JP Conservation Ecology and Animal Behaviour Group Department of Post-Graduate Studies in Zoology Pr6dio 41 Pontificia Universidade Cat61ica de Minas Gerais Av. Dom Jos6 Gaspar 500 Cora~o Eucarfstico 30535-610 Belo Horizonte Minas Gerais Brazil Cognitive Science Centre Rue Emile Argand 11 University of Neuch~tel Neuch~tel Switzerland

There is relatively good evidence that non-human primates can communicate about objects and events in their envi- ronment in ways that allow recipients to draw inferences about the nature of the event experienced by the signaller. In some spe- cies, there is also evidence that the basic semantic units are not individual calls, but call sequences and the combinations gener- ated by them. These two findings are relevant to theories pertaining to the origins of human language because of the resemblances of these phenomena with linguistic reference and syntactic organisation. Until recently, however, most research efforts on the primate origins of human language have involved Old World species with comparatively few systematic studies on New World monkeys, which has prevented insights into the deeper phylogenetic roots and evolutionary origins of language-relevant capaci- ties. To address this, we review the older primate literature and very recent evidence for functionally referential communication and call combinations in New World primates. Within the existing literature there is ample evidence in both Callitrichids and Ce- bids for acoustically distinct call variants given to external disturbances that are accompanied by distinct behavioural responses. A general pattern is that one call type is typically produced in response to a wide range of general disturbances, often on the ground but also including inter-group encounters, while another call type is produced in response to a much narrower range of aerial threats. This pattern is already described for Old World monkeys and Prosimians, suggesting an early evolutionary origin. Second, recent work with black-fronted tiff monkeys has produced evidence for different alarm call sequences consisting of acoustically distinct call types. These sequences appear to encode several aspects of the predation event simultaneously, notably predator type and location. Since meaningful call sequences have already been described in

关键词： Primate alarm calls Functionally referential calls Call combinations New World monkeys Old World monkeys

Designing near-natural planting patterns for plantation forests in China

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Forest Ecosystems 2019年第3期6卷 236-248页

作者： Gongqiao Zhang Gangying Hui Yanbo Hu Zhonghua Zhao Xiuling Guan klaus von Gadow Ganggang Zhang Research Institution of Forestry Chinese Academy of ForestryBeijing 100091China Chinese Society of Forestry Beijing 100091China University of Gotingen GotingenGermany

Background: China has a long tradition of managing planted forests. Different species of Populus, Eucalyptus, Larix, Cunninghamia and Pinus are planted to satisfy the local demand for wood products and provide ecological services at the same time. Evidence of the greater resilience of natural forests provides the motivation to develop asymmetric planting patterns, which is the focus of this study. We present a new method for designing plantation patterns that follow those observed in natural ecosystems and to maintain some regularity for operational convenience. Methods: Based on the uniform angle index, we analyzed the spatial structure of six natural forests in different regions of China. The uniform angle index describes the degree of spatial uniformity of the n nearest neighbors of a given reference tree. Accordingly, we identified all possible patterns of a neighborhood group within a regular planting pattern and developed a method to optimize planting point arrangements that contain some randomness as well as a minimum degree of regularity. Results:(1) There are 13 types of structural units in a regular planting, including seven random units, five even units and one cluster unit;(2) Five near-natural arrangements are presented with a minimum proportion of 50% of random units. These five arrangements represent a combination of regularity for operational convenience and asymmetry. Conclusions: The new planting patterns developed in this study are expected to increase the asymmetric competition and resilience of these important ecosystems. Some experimental plantings, based on our findings, have already been established, e.g., in Pinus tabulaeformis plantations in Tianshui, Gansu Province, and in a Populus deltoides plantation in Fangshan near Beijing.

关键词： Plantation Near-natural forest Uniform angle index Forest spatial structure Asymmetric competition

Palaeoenvironmental setting of lacustrine stromatolites in the Miocene Wudaoliang Group, northern Tibetan Plateau

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Journal of Palaeogeography 2019年第3期8卷 270-284页

作者： Ling-Qi Zeng Hai-Sheng Yi Guo-Qing Xia klaus Simon Christine Heim Gernot Arp Institute of Sedimentary Geology Chengdu University of Technology Chengdu 610059 Sichuan Province China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu 610059 Sichuan Province China Geoscie nee Center Georg-August-Universitat Gottingen GoldschmidtstraBe 3 37077 Gottingen Germany

Lacustrine stromatolites were widespread in the Miocene Wudaoliang Group(stromatolites of the Wudaoliang Group), northern Tibetan Plateau;but only at one location nearby the Wudaoliang Town, they occurred intensively in thick, laterally traceable beds(Wudaoliang stromatolites). Although deposited in lacustrine environment, the lack of fossils in these rocks hampers determining whether the stromatolites formed in freshwater or saline *** address this problem, and in an attempt to identify criteria to distinguish differences of freshwater and saline conditions, we studied the laminae microfabrics, stable carbon and oxygen isotope ratios, rare earth element patterns and biomarkers of the stromatolites. These stromatolites can be divided into fenestral stromatolites and agglutinated stromatolites. The fabric of fenestral stromatolites is formed by microcrystalline carbonate enclosing spar-cemented, angular crystal traces. Essentially, this fabric is interpreted as pseudomorph after former formed evaporite crystals. Faecal pel ets identical to that of the present-day brine shrimp Artemia, lack of other eukaryotic fossils,and stable isotopic signals point to a shal ow, evaporation-dominated hypersaline lake setting. Covariation of carbon and oxygen isotopes indicates hydrological y closed conditions of the Miocene lake on northern Tibetan ***, if compared to other lacustrine carbonates of the Wudaoliang Group, the high δ13 C values of the investigated Wudaoliang stromatolites reveal an additional photosynthetic effect during the deposition of the ***, although no direct evidence is available from field observations and microfabrics, a positive europium anomaly of Wudaoliang stromatolites indicates that a palaeo-hydrothermal inflow system had existed in the outcrop *** new results favour a hypersaline lake setting subject to hot spring inflow for the Wudaoliang stromatolites, in contrast to earlier interpretations suggesti

关键词： Lacustrine stromatolites Miocene Wudaoliang Group Hypersaline lake Hydrothermal Northern Tibetan plateau

Effects of supplementation of green tea extract on the milk performance of peripartal dairy cows and the expression of stress response genes in the liver

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Journal of Animal Science and Biotechnology 2020年第4期11卷 1163-1174页

作者： Denise K.Gessner Corinna Brock Lena M.Hof Erika Most Christian Koch klaus Eder Institute of Animal Nutrition and Nutrition Physiology Justus-Liebig-University GiessenHeinrich-Buff-Ring 26-3235392 GiessenGermany Educational and Research Centre for Animal Husbandry Hofgut Neumühle67728 Münchweiler an der AlsenzGermany.

Background: We hypothesised that supplementation of green tea extract(GTE) in dairy cows during the transition period can attenuate proinflammatory conditions and prevent endoplasmic reticulum(ER) stress in the liver of these cows. Thirty Holstein cows with an average parity of 3.06(± 1.31, SD) were divided into a control group and a group that received a daily amount of 10 g of GTE from d 7 before the calving day and a daily amount of 20 g of GTE from the day of calving until d 7 of ***: Cows supplemented with GTE did not show differences in energy intake or milk yield in weeks 2–7 of lactation. However, these cows had a lower milk fat concentration and a lower energy corrected milk yield than the control cows and showed a trend of improved energy balance. The relative m RNA concentrations of proinflammatory genes, genes involved in the acute phase reaction and antioxidant genes in the liver in weeks 1, 4 and 7 of lactation were not different between the two groups of cows. The concentrations of α-tocopherol and the Trolox equivalent antioxidant capacity in plasma were not different between the two groups. However, the group supplemented with GTE showed significant reductions of some genes of the unfolded protein response(UPR) in week 1 and a trend of lower liver triacylglycerol(TAG) concentrations in the liver compared to the control ***: This study shows that supplementation of GTE in dairy cows lowers the fat concentration in the milk but overall has no effect on the expression of inflammatory genes and the antioxidative status in dairy cows during early lactation. The finding of reduced m RNA levels of genes involved in the UPR at week 1, however, supports other results showing that supplementation of polyphenols could prevent the development of ER stress in the liver of cows during early lactation. The finding of a tendency towards a reduced TAG concentration in the liver of cows supplemented with GTE might be due to an improved ene

关键词： Animal nutrition Cow Green tea extract Liver Metabolism Milk performance