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TLR signaling that induces weak inflammatory response and SHIp1 enhances osteogenic functions

Bone Research 2014年第4期2卷 218-230页

作者： Manoj Muthukuru richard p darveau West Virginia University Department of PeriodonticsSchool of DentistryMorgantownWVUSA University of Washington Department of PeriodonticsSchool of DentistrySeattleWAUSA

Toll-like receptor （TLR）-mediated inflammatory response could negatively affect bone metabolism. In this study, we determined how osteogenesis is regulated during inflammatory responses that are downstream of TLR signaling. Human primary osteoblasts were cultured in collagen gels. pam3CSK4 （p3C） and Escherichia coli lipopolysaccharide （EcLpS） were used as TLR2 and TLR4 ligand respectively. porphyromonas gingivalis LpS having TLR2 activity with either TLR4 agonism （pg1690） or TLR4 antagonism （pg1449） and mutant E. coli LpS （LpxE/LpxF/WSK） were used. IL-lp, SH2-containing inositol phosphatase-1 （SHIp1） that has regulatory roles in osteogenesis, alkaline phosphatase and mineralization were analyzed. 3α-Aminocholestane （3AC） was used to inhibit SHIp1. Our results suggest that osteoblasts stimulated by p3C, poorly induced IL-1β but strongly upregulated SHIp1 and enhanced osteogenic mediators. On the contrary, EcLpS significantly induced IL-1β and osteogenic mediators were not induced. While pg1690 downmodulated osteogenic mediators, pg1449 enhanced osteogenic responses, suggesting that TLR4 signaling annuls osteogenesis even with TLR2 activity. Interestingly, mutant E. coli LpS that induces weak inflammation upregulated osteogenesis, but SHIp1 was not induced. Moreover, inhibiting SHIp1 significantly upregulated TLR2-mediated inflammatory response and downmodulated osteogenesis. In conclusion, these results suggest that induction of weak inflammatory response through TLR2 （with SHIp1 activity） and mutant TLR4 ligands could enhance osteogenesis.

关键词： TLR signaling that induces weak inflammatory response and SHIp1 enhances osteogenic functions SHIp Figure

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porphyromonas gingivalis Resistance to polymyxin B Is Determined by the Lipid A 4’-phosphatase, pGN_0524

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International Journal of Oral Science 2009年第3期1卷 126-135页

作者： Stephen R. Coats Thao T. To Sumita Jain pamela H. Braham richard p. darveau Department of periodontics School of Dentistry University of Washington Seattle USA

Aim To elucidate the genetic basis for the pronounced resistance that the oral pathogen, porphyromonas gingivalis （p. gingivalis）, exhibits towards the cationic antimicrobial peptide, polymyxin B. Methodology A genetic screen of p. gingivalis clones generated by a Tn4400-based random insertion mutagenesis strategy was performed to identify bacteria harboring novel genetic mutations that render p. gingivalis susceptible to killing by the cationic antimicrobial peptide, polymyxin B （pMB, 50μg·mL^-1）. Results p. gingivalis （ATCC 33277） is unusually resistant to the cationic antimicrobial peptide, pMB at relatively high concentrations （200μg·mL^-1）. Approximately 2,700 independent Tn4400 ＇-derived mutants ofp. gingivalis were examined for increased sensitivity to pMB killing at a relatively low dose （50 μg·mL^-1）. A single pMB-sensitive mutant was obtained in this phenotypic screen. We determined that the Tn4400＇ transposon was integrated into the gene encoding the lipid A 4＇-phosphatase, pGN 0524, demonstrating that this insertion event was responsible for its increased susceptibility of this clone to pMB-dependent killing. The resulting mutant strain, designated 0524-Tn4400＇, was highly sensitive to pMB killing relative to wild-type p. gingivalis, and exhibited the same sensitivity as the previously characterized strain, 0524KO, which bears a genetically engineered deletion in the pGN_0524 locus. positive ion mass spectrometric structural （MALDI-TOF MS） analyses revealed that lipid A isolates from 0524-Tn4400＂ and 0524KO strains displayed strikingly similar MALDI-TOF MS spectra that were substantially different from the wildtype p gingivalis lipid A spectrum. Finally, intact 0524- Tn4400＇ and 0524KO mutant bacteria, as well as their corresponding LpS isolates, were significantly more potent in stimulating Toll-like receptor 4 （TLR4）-dependent E-selectin expression in human endothelial cells relative to intact wild-type p.. gingivalis or its corresponding LpS isolate.

关键词： p. gingivalis antimicrobial peptide lipid A phosphatase polymyxin B transposon lipopolysaccharide

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A Method of Characterizing Radio Signal Space for Wireless Device Localization

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Tsinghua Science and Technology 2015年第4期20卷 385-408页

作者： John-Austen Francisco richard p.Martin Department of Computer Science Rutgers University

In this work we present a novel approach for describing radio signal spaces for localization algorithms. We first introduce a new metric, the Discretely Distributed Log-H61der Metric （DDLHM）. The DDLHM is designed to characterize the type and degree of signal distortion relative to Iognormal signal-to-distance path models. We first show how the DDLHM can describe and discriminate distortions in an exhaustive set of synthetic signal spaces. We then determine a reduced set of maximally diagnostic distortion parameters. Using only 4% of the maximal set of DDLHMs, we found the reduced set matches with an acceptable degree of error 95% of the time. Using the synthetic reduced set, we characterized a variety of wireless localization algorithms＇ behaviors to attenuation, bias, and multipath. We found algorithms made much different tradeoffs between best case and average case error. We then use the DDLHM to identify distortion types in three different physical environments using measured 802.11 signal strengths, and predict the positioning performance of several localization algorithms. Our approach predicts average localization error to within 2 meters of the observed average error.

关键词： radio propgation 802.11 WiFi

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Trees of panama: A complete checklist with every geographic range

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Forest Ecosystems 2020年第3期7卷 526-538页

作者： richard Condit Salomón Aguilar Rolando pérez Morton Arboretum 4100 Illinois Rte.53Lisle60532ILUSA Smithsonian Tropical Research Institute Panama CityPanama

Background Central America is one of the most diverse floristic provinces in the world,but comprehensive plant lists for the region are incomplete and need frequent *** geographic ranges of individual species are seldom *** detailed forest inventory plots of panama thus lack a global geographic *** order to provide one,we assembled a thoroughly vetted checklist of all tree species of panama,along with an estimate of each one’s range size based on published specimen *** 1)panama has 3043 tree species in 141 families and 752 genera;57.6%were≥10 m tall and 16.9%were 3-5 m tall.2)The widest ranges were>1.5×107 km2,covering the entire neotropics and reaching>30∘latitude;12.4%of the species had ranges exceeding 107 *** median range was 6.9×105 km2.3)At the other extreme,16.2%of the species had a rangepecies’height and varied significantly among families.5)Tree census plots,where we mapped and measured all individuals,captured 27.5%of the tree species,but a biased selection relative to range size;only 4.5%of the species in plots had rangespanama,based on rigorous criteria aimed at matching plot censuses,is 20%larger than *** recording species’maximum heights,we allow comparisons with other regions based on matching definitions,and the range sizes provide a quantitative basis for assessing extinction *** next goal is to merge population density from plot censuses to add rigor to predictions of extinction risk of poorly-studied tropical tree species.

关键词： red Trees of panama A complete checklist with every geographic range

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How generalists coexist: the role of floral phenotype and spatial factors in the pollination systems of two Ranunculus species

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Journal of plant Ecology 2014年第5期7卷 480-489页

作者： richard p.Kipling John Warren Institute of Biological Environmental and Rural Science Aberystwyth UniversityPenglais CampusAberystwythCeredigionSY233FGUK

Aims Competition for pollinators between phenotypically similar flowers is believed to play an important role in floral trait diversification in the ***,in many plant communities,species with apparently similar floral phenotypes and generalist pollina-tion systems ***,the pollination systems of Ranunculus acris *** Ranunculus repens *** investigated to determine the factors enabling the species to coexist within apparently over-lapping pollination *** Sympatrically flowering populations of *** and *** were investigated at three study sites in West *** flo-ral phenotypes of the two species were compared using meas-urements of floral morphology and spectral analyses of petal reflectance,using principal component analysis and bee and fly colour-space *** of inter-specific discrimina-tion by foraging insects was tested for in the field and using floral *** relative roles of behavioural constancy and spatial patchiness in maintaining pollinator fidelity were *** Findings The floral phenotypes of *** and *** differed *** bees were highly constant when foraging at flowers of the two species and patchy floral distribution explained some of the observed *** visiting mixed floral arrays appeared to discriminate between the species,visiting more *** than *** flowers,but there was no difference in the number of vis-its to single-species *** bees were more likely to display constancy to flowers of *** in the *** in floral distribution,subtle differences in floral phenotype,pollinator preferences and behavioural constancy are all likely to con-tribute to the continued coexistence of *** and ***,despite apparent overlap in their pollination *** differences have the potential to facilitate the maintenance of species diversity in plant com-munities,even where plants appear to share similar floral p

关键词： floral phenotype pollination niche Ranunculus functional specialization constancy

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Sexual selection in cane toads Rhinella marina： A male＇s body size affects his success and his tactics

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Current Zoology 2013年第6期59卷 747-753页

作者： Haley BOWCOCK Gregory p. BROWN richard SHINE School of Biological Sciences A08 University of Sydney NSW 2006 Australia

Abstract Male body size can play an important role in the mating systems of anuran amphibians. We conducted labora- tory-based trials with cane toads Rhinella （Bufo） marina from an invasive population in the wet-dry tropics of northern Australia, to clarify the effects of a male＇s body size on his reproductive success and behavior （mate choice）. Males were stimulated with a synthetic hormone to induce reproductive readiness. Larger body size enhanced a male toad＇s ability to displace a smaller rival from amplexus, apparently because of physical strength： more force was required to dislodge a larger than a smaller amplectant male. A male＇s body size also affected his mate-choice criteria. Males of all body sizes were as likely to attempt amplexus with another male as with a female of the same size, and preferred larger rather than smaller sexual targets. However, this size prefe- rence was stronger in larger males and hence, amplexus was size-assortative. This pattern broke down when males were given access to already-amplectant male-female pairs： males of all body sizes readily attempted amplexus with the pair, with no size discrimination. An amplectant pair provides a larger visual stimulus, and prolonged amplexus provides a strong cue for sex iden- tification （one of the individuals involved is almost certainly a female）. Thus, a male cane toad＇s body size affects both his ability to defeat rivals in physical struggles over females, and the criteria he uses when selecting potential mates, but the impacts of that selectivity depend upon the context in which mating occurs

关键词： Mating systems Size-assortative mating Large-male advantage Anurans Invasive species

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Observations of defect propagation in [100]-oriented opal-type photonic crystals

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Chinese physics B 2008年第4期17卷 1298-1304页

作者：金崇君 richard M.De La Rue Nigel p.Johnson Department of Electronics & Electrical Engineering University of Glasgow School of physics and Engineering Laboratory of Optoelectronic Materials and TechnologiesSun Yat-Sen University

Charged colloidal suspensions have been used as experimental models for the study of crystal nucleation. Here we propose that the technique of template-assisted colloidal self-assembly can be used to visualize the effects of defect propagation in atomic crystal films produced using epitaxial growth. Templates with periodic line defects were used to grow [100]-oriented three-dimensional photonic crystals by means of the template-assisted colloidal self-assembly method, aided by capillary and gravitational forces. The defect propagation in the [100]-oriented photonic crystal was observed using scanning electron microscopy, both at the surface of the crystal and on cleaved facets. This method is useful in the understanding of defect propagation in the growth of colloidal films on templates - and the same approach may also prove useful for the understanding of atomic crystal growth on substrates with defects. Additionally, the deliberate incorporation of line defects may prove valuable as a way of introducing waveguide channels into three-dimensional photonic crystals.

关键词： photonic crystal colloidal crystal self-assembly

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Copper Salt Catalyzed Amidations of Haloalkynes in the Synthesis of Ynamides

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复旦学报（自然科学版） 2005年第5期44卷 676-677页

作者： richard p. Hsung Department of Chemistry University of Minnesota Minneapolis Minnesota 55455 USA

Ynamines [1-aminoalkynes, or N-alkynyl amines] have endured through two contrasting phases in the last four decades. First, they enjoyed a phase of synthetic eminence after the establishment of a practical synthesis in 1963. In the ensuing twenty years, ynamines became one of the most synthetically useful subgroups of alkynes utilized in countless creative work by many synthetic chemists. Reactivities of 1-aminoalkynes were thoroughly explored. However, unlike its close relative enamines, this prominent period did not last. The extent of synthetic application of ynamines has suffered a dramatic decline during the last twenty years. This decline characterizes the second phase of ynamines. The limited synthetic application of ynamines is largely due to the difficulties in preparation and handling of ynamines. Their sensitivity toward hydrolysis and their high reactivity render ynamines synthetically inaccessible in diversity.

关键词：铜盐酰胺化物催化物碳杂交变化立体选择性

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Novel design concepts for network intrusion systems based on dendritic cells processes

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Journal of Central South University 2013年第8期20卷 2175-2185页

作者： richard M R 谭冠政 ONGALO p N F CHERUIYOT W School of Information Science and Engineering Central South University

An abstraction and an investigation to the worth of dendritic cells (DCs) ability to collect, process and present antigens are presented. Computationally, this ability is shown to provide a feature reduction mechanism that could be used to reduce the complexity of a search space, a mechanism for development of highly specialized detector sets as well as a selective mechanism used in directing subsets of detectors to be activated when certain danger signals are present. It is shown that DCs, primed by different danger signals, provide a basis for different anomaly detection pathways. Different antigen-peptides are developed based on different danger signals present, and these peptides are presented to different adaptive layer detectors that correspond to the given danger signal. Experiments are then undertaken that compare current approaches, where a full antigen structure and the whole repertoire of detectors are used, with the proposed approach. Experiment results indicate that such an approach is feasible and can help reduce the complexity of the problem by significant levels. It also improves the efficiency of the system, given that only a subset of detectors are involved during the detection process. Having several different sets of detectors increases the robustness of the resulting system. Detectors developed based on peptides are also highly discriminative, which reduces the false positives rates, making the approach feasible for a real time environment.

关键词： artificial immune systems network intrusion detection anomaly detection feature reduction negative selectionalgorithm danger model

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pulse generation with ultra-superluminal pulse propagation in semiconductor heterostructures by superradiant-phase transition enhanced by transient coherent population gratings

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Light(Science & Applications) 2016年第1期5卷 737-743页

作者： peter p Vasil’ev richard V penty Ian H White Centre for photonic Systems Department of EngineeringUniversity of CambridgeCambridge CB30FAUK Quantum Electronics Division PN Lebedev Physical InstituteMoscow 119991Russia

This paper reports the observation of ultra-superluminal pulse propagation in multiple-contact semiconductor heterostructures in a superradiant emission regime,and shows definitively that it is a different class of emission from conventional spontaneous or stimulated *** population gratings induced in the semiconductor medium under strong electrical pumping have been shown to cause a major decrease of the group refractive index,in the range of 5–40%.This decrease is much greater than that caused by conventional carrier depletion or chirp *** decrease in refractive index in turn causes faster-than-c propagation of femtosecond *** measurement also proves the existence of coherent amplification of electromagnetic pulses in semiconductors at room temperature,the coherence being strongly enhanced by interactions of the light with coherent transient gratings locked to carrier *** pulse-generation technique is anticipated to have great potential in applications where highly coherent femtosecond optical pulses must be generated on demand.

关键词： phase transition population grating superradiance superluminal propagation

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