965 resultados para John Paul Stevens
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Although the importance of clathrin- and caveolin-independent endocytic pathways has recently emerged, key aspects of these routes remain unknown. Using quantitative ultrastructural approaches, we show that clathrin-independent carriers (CLICs) account for approximately three times the volume internalized by the clathrin-mediated endocytic pathway, forming the major pathway involved in uptake of fluid and bulk membrane in fibroblasts. Electron tomographic analysis of the 3D morphology of the earliest carriers shows that they are multidomain organelles that form a complex sorting station as they mature. Proteomic analysis provides direct links between CLICs, cellular adhesion turnover, and migration. Consistent with this, CLIC-mediated endocytosis of key cargo proteins, CD44 and Thy-1, is polarized at the leading edge of migrating fibroblasts, while transient ablation of CLICs impairs their ability to migrate. These studies provide the first quantitative ultrastructural analysis and molecular characterization of the major endocytic pathway in fibroblasts, a pathway that provides rapid membrane turnover at the leading edge of migrating cells.
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Within the history of twentieth-century design, there are a number of well-known objects and stories that are invoked time and time again to capture a pivotal moment or summarize a much broader historical transition. For example, Marcel Breuer’s Model B3 chair is frequently used as a stand-in for the radical investigations of form and new industrial materials occurring at the Bauhaus in the mid-1920s. Similarly, Raymond Loewy’s streamlined pencil sharpener has become historical shorthand for the emergence of modern industrial design in the 1930s. And any discussion of the development of American postwar “organic design” seems incomplete without reference to Charles and Ray Eames’s molded plywood leg splint of 1942. Such objects and narratives are dear to historians of modern design. They are tangible, photogenic subjects that slot nicely into exhibitions, historical surveys, and coffee-table best sellers...
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Evaluation of protein and metabolite expression patterns in blood using mass spectrometry and high-throughput antibody-based screening platforms has potential for the discovery of new biomarkers for managing breast cancer patient treatment. Previously identified blood-based breast cancer biomarkers, including cancer antigen 15.3 (CA15-3) are useful in combination with imaging (computed tomography scans, magnetic resonance imaging, X-rays) and physical examination for monitoring tumour burden in advanced breast cancer patients. However, these biomarkers suffer from insufficient levels of accuracy and with new therapies available for the treatment of breast cancer, there is an urgent need for reliable, non-invasive biomarkers that measure tumour burden with high sensitivity and specificity so as to provide early warning of the need to switch to an alternative treatment. The aim of this study was to identify a biomarker signature of tumour burden using cancer and non-cancer (healthy controls/non-malignant breast disease) patient samples. Results demonstrate that combinations of three candidate biomarkers from Glutamate, 12-Hydroxyeicosatetraenoic acid, Beta-hydroxybutyrate, Factor V and Matrix metalloproteinase-1 with CA15-3, an established biomarker for breast cancer, were found to mirror tumour burden, with AUC values ranging from 0.71 to 0.98 when comparing non-malignant breast disease to the different stages of breast cancer. Further validation of these biomarker panels could potentially facilitate the management of breast cancer patients, especially to assess changes in tumour burden in combination with imaging and physical examination.
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Lung cancer is the second most common type of cancer in the world and is the most common cause of cancer-related death in both men and women. Research into causes, prevention and treatment of lung cancer is ongoing and much progress has been made recently in these areas, however survival rates have not significantly improved. Therefore, it is essential to develop biomarkers for early diagnosis of lung cancer, prediction of metastasis and evaluation of treatment efficiency, as well as using these molecules to provide some understanding about tumour biology and translate highly promising findings in basic science research to clinical application. In this investigation, two-dimensional difference gel electrophoresis and mass spectrometry were initially used to analyse conditioned media from a panel of lung cancer and normal bronchial epithelial cell lines. Significant proteins were identified with heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1), pyruvate kinase M2 isoform (PKM2), Hsc-70 interacting protein and lactate dehydrogenase A (LDHA) selected for analysis in serum from healthy individuals and lung cancer patients. hnRNPA2B1, PKM2 and LDHA were found to be statistically significant in all comparisons. Tissue analysis and knockdown of hnRNPA2B1 using siRNA subsequently demonstrated both the overexpression and potential role for this molecule in lung tumorigenesis. The data presented highlights a number of in vitro derived candidate biomarkers subsequently verified in patient samples and also provides some insight into their roles in the complex intracellular mechanisms associated with tumour progression.
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Amphiphilic sugars exhibit both lyotropic and thermotropic liquid-crystalline behavior. Interestingly, in spite of the abundance of chiral centers in amphiphilic sugars, their liquid-crystalline phases do not exhibit macroscopic chirality. Herein, we report on the first observation of macroscopic chirality in sugar-based bolaamphiphiles containing free hydroxyl groups. The manifestation of the chiral smectic C* phase in these bolaamphiphiles has been observed to be critically dependent on the presence of the azobenzene moiety and the suitable length of the methylene spacer. These results imply that by suitable selection of linker groups, mesogenic bolaamphiphiles possessing macroscopic chirality can be designed using a variety of naturally available sugar derivatives.
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The numbers and mean radio luminosities of giant radio galaxies (GRGs) have been calculated for redshifts up to z = 0.6, assuming a sensitivity limit of 1 Jy at 1 GHz for the observations. The estimates are obtained with a model for the beam propagation, first through the hot gaseaous halo around the parent galaxy, and thereafter, through the even hotter but less dense intergalactic medium. The model is able to accurately reproduce the observed numbers and mean radio luminosities of GRGs at redshifts of less than 0.1, and it predicts that a somewhat larger number of GRGs should be found at redshifts of greater than 0.1.
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Be/X-ray binary pulsars have wide eccentric orbits and hence the angle of periastron of the orbit is very well defined in these sources. The presence of an X-ray pulsar allows for accurate measurements of orbital elements. A Be star usually is a rapidly rotating star and hence will deviate from spherical geometry. The tidal interaction between the neutron star and the Be star will add to the distortion of the Be star and alter its mass distribution. Thus a measurable rate of apsidal motion is expected from these systems. In this paper, we present the first conclusive detection of apsidal motion of the binary 4U 0115+63. We also present new and accurate orbital parameters of the Be/X-ray binaries V0332+53 and 2S 1417-624.
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John Dewey (1859-1952) oli yhdysvaltalainen filosofi, pedagogi ja julkinen keskustelija, jonka ajattelu on merkittävästi vaikuttanut pragmatismina tunnetun filosofisen suuntauksen kehittymiseen. Tässä Pro gradu -tutkielmassa tarkastellaan Devveyn poliittista filosofiaa ja ajattelua. Tarkoituksena on selvitellä, millaista on Devveyn poliittinen filosofia ja voiko hänen pragmatistinen poliittinen filosofiansa tarjota jotain mielenkiintoista myös tämän päivän poliittisen filosofian kentälle. Tutkielmassa tarkastellaan Devveyn esittämää kritiikkiä klassista liberalismia ja individualismia kohtaan, Devveyn omaa poliittisen filosofian projektia sekä sen kohtaama kritiikkiä ja arvioidaan Devveyn poliittista filosofiaa yleisesti. Tarkastelun kohteena ovat muun muassa Devveyn käsitykset yksilöstä, valtiosta, demokratiasta, vallasta ja tiedosta. Ensisijaisena lähteenä tutkielmassa on Devveyn koottujen teosten sarja vuosilta 1882-1953, ennen kaikkea 1920-30-lukujen tuotanto. Lisäksi lähteenä on useita tuoreita artikkeleita sekä kommentaareja. Keskeisin löytö tutkielmassa on, että Devveyn poliittisen filosofian oleellinen piirre on "anti-essentialismi", eli huomion siirtäminen pois jostain oletetuista yksilöiden ja ryhmien olemuksista tai sisäisestä luonnosta niiden välisiin suhteisiin ja näiden ilmauksiin. Tähän liittyen Devveyn poliittisen filosofian keskeiseksi lähtökohdaksi osoittautuu perinteisen yksilö-yhteisö jaottelun kyseenalaistaminen. Tutkielma tarjoaa laajan katsauksen Devveyn poliittiseen ajatteluun sekä pragmatistiseen poliittiseen filosofiaan.
Resumo:
Three tripeptides containing a central Z-dehydrophenylalanine residue (Δz-Phe), Boc-L-Phe-Δz-Phe-X-OMe (X = L-Val 1, L-Leu 2 and X = L-Ala 3) have been synthesized and their solution conformations investigated by 270 MHz 1H NMR spectroscopy. In all three peptides, conformations involving the X residue NH in an intramolecular hydrogen bond were favoured in CDCl3 solutions. Studies of the nuclear Overhauser effect (NOE) provided support for a Type II β turn conformation in these peptides with Phe and Δz-Phe occupying the i + 1 and i + 2 positions, respectively. Significantly different conformations lacking any intramolecular hydrogen bonds were observed for peptide 1 in (CD3)2SO. NOE results were consistent with a significant population of molecules having semi-extended conformations (ø > 100°) at the Δz-Phe residue.
Resumo:
Tutkielman tarkoituksena oli soveltaa toistetun pelin teoria- ja empiriapohjaa suomalaiseen tutkimusaineistoon. Kartellin toimintadynamiikka on mallinnettu peliteorian osa-alueen, toistetun pelin kentäksi. Toistetussa pelissä samaa, kerran pelattua peliä pelataan useita kierroksia. Äärettömästi toistetusta pelistä muodostuu toistetun pelin yleinen teoria (The Folk Theorem), jossa jokaisella pelaajalla on yksilöllisesti rationaalinen käytössykli. Toisen pelaajan kanssa tehty yhteistyö kasvattaa pelaajan käytössykliltä kertyvää kokonaishyötyä. Kartellitutkimuksessa ei voi ohittaa oikeustieteellistä näkökulmaa, joten sekin on tiivistetysti mukana esityksessä. Äänettömässä tai implisiittisessä kartellissa ( tacit collusion ) ei avoimen kartellin tavoin ole osapuolten välistä kommunikointia, mutta sen lopputulos on sama. Tästä syystä äänetön kartelli on yhdenmukaistettuna käytöksenä kielletty. Koska myös tunnusmerkit ovat osin samat, kartellitutkimus on saanut arvokasta mittausaineistoa paljastuneiden kartellien käytöksestä. Pelkkään hintatiedostoonkin perustuvalla tutkimuksella on vankka teoreettinen ja empiirinen pohja. Oikeuskirjallisuudessa ja käytännössä hintayhteneväisyyden on yhdessä muiden tunnusmerkkien kanssa katsottu olevan indisio kartellista. Bensiinin vähittäismyyntimarkkinat ovat rakenteellisesti otollinen kenttä toistetulle pelille. Tutkielman empiirisessä osuudessa kohteena olivat pääkaupunkiseudun bensiinin vähittäismyyntimarkkinat ja tiedosto sisälsi otoksia hinta-aikasarjoista ajalta 1.8.2004 - 30.6.2005 kaikkiaan 116:ltä jakeluasemalta Espoosta, Helsingistä ja Vantaalta. Tutkimusmenetelmänä oli toistettujen mittausten varianssianalyysi post hoc-vertailuin. Tilastollisesti merkitsevä hinnoitteluyhtenevyys lähellä sijaitsevien asemien kesken löytyi 47 asemalta, ja näin ollen näillä asemilla on yksi kartellin tunnusmerkeistä. Hinnoitteluyhtenevyyden omaavat asemat muodostivat liikenneyhteyksien mukaan jaetuilla kilpailualueillaan ryhmittymiä ja kaikkiaan tällaisia yhtenevästi hinnoittelevia ryhmittymiä oli 21. Näistä ryhmittymistä 9 oli ns. sekapareja eli osapuolina olivat kylmäasema ja liikenneasema. Useimmissa tapauksissa oli kyseessä alueensa kalleimmin hinnoitteleva kylmäasema. Tutkielman tärkeimmät lähteet: Abrantes-Metz, Rosa M. – Froeb, Luke M. – Geweke, John F. – Taylor, Cristopher T. (2005): A Variance screen for collusion. Working paper no. 275, Bureau of economics, Federal Trade Commission, Washington DC 20580. Dutta, Prajit K. (1999): Strategies and Games, Theory and Practice. The MIT Press, Cambridge, Massachusetts, London, England. Harrington, Joseph E. (2004): Detecting cartels. Working paper. John Hopkins University. Ivaldi, Marc – Jullien, Bruno – Rey, Patric – Seabright, Paul – Tirole, Jean (2003): The Economics of Tacit Collusion. EU:n komission kilpailun pääosaston julkaisu. Phlips, Louis (1996): On the detection of collusion and predation. European Economic Review 40 (1996), 495–510.
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This article documents the addition of 229 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Acacia auriculiformis x Acacia mangium hybrid, Alabama argillacea, Anoplopoma fimbria, Aplochiton zebra, Brevicoryne brassicae, Bruguiera gymnorhiza, Bucorvus leadbeateri, Delphacodes detecta, Tumidagena minuta, Dictyostelium giganteum, Echinogammarus berilloni, Epimedium sagittatum, Fraxinus excelsior, Labeo chrysophekadion, Oncorhynchus clarki lewisi, Paratrechina longicornis, Phaeocystis antarctica, Pinus roxburghii and Potamilus capax. These loci were cross-tested on the following species: Acacia peregrinalis, Acacia crassicarpa, Bruguiera cylindrica, Delphacodes detecta, Tumidagena minuta, Dictyostelium macrocephalum, Dictyostelium discoideum, Dictyostelium purpureum, Dictyostelium mucoroides, Dictyostelium rosarium, Polysphondylium pallidum, Epimedium brevicornum, Epimedium koreanum, Epimedium pubescens, Epimedium wushanese and Fraxinus angustifolia.