710 research outputs found
Interação do fator reumatóide e Entamoeba histolytica
The amoebae's cytotoxicity test and the amoebae's lysis test were used to show possible interactions between rheumatoid factor (RF) and Entamoeba histolytica. Amoebae's cytotoxic activity (ACA) was inhibited by affinity chromatography purified antiamoebae rabbit IgG (RIgG). Enhanced inhibition could be demonstrated with RIgG plus RF. But the same marked inhibition of ACA could be seen when replacing RF by heat inactivated normal human serum as a control. About 50% amoebae's lysis occurred when amoebae were brought together with native normal human serum (NNHS) as a source of complement. Amoebae's lysis increased to 60% when incubated with NHS plus human antiamoebae antibodies. No further augmentation could be obtained by the addition of RF. Using RIgG instead of human antibodies the lysis rate did not increase. Incubation of amoebae, NNHS, RIgG and RF even reduced amoebae's lysis. RF neither has an effect on ACA nor on complement mediated AL in vitro.Testes para citotoxicidade e lise amebiana foram utilizados para demonstrar uma possÃvel interação entre o fator reumatóide e a Entamoeba histolytica. A atividade citotóxica amebiana foi inibida pela IgG antiameba de coelho purificada através de cromatografia. Constatou-se inibição aumentada com IgG antiameba de coelho mais fator reumatóide. A mesma inibição acentuada da atividade citotóxica amebiana pôde ser constatada quando se substituiu o fator reumatóide por soro humano normal, inativado pelo calor, como controle. Cerca de 50% de lise amebiana ocorreu quando as amebas foram misturadas com soro normal humano como fonte de complemento. A lise amebiana aumentou para 60% quando incubadas com soro humano normal, acrescido de anticorpos humanos antiameba. Nenhum aumento adicional pode ser obtido pela adição de fator reumatóide. Usando IgG antiameba de coelho em vez de anticorpos humanos, a proporção de lise não aumentou. A incubação de amebas com soro humano normal, IgG antiameba de coelho e fator reumatóide reduziu acentuadamente a lise amebiana. O fator reumatóide não teve efeito na atividade citotóxica amebiana, nem na lise amebiana mediada pelo complemento in vitro
DOCUMENTARY CONTEXTS FOR THE ‘PISTIROS INSCRIPTION’
This preliminary study of the so-called ‘Pistiros Inscription’ challenges the dominantinterpretation of the document that has crystallized in the years since its preliminary publication,namely, that the inscription somehow guarantees the rights of traders operating within Pistiros.A reexamination of the rhetorical structure of the inscription and a reconstruction of the inscription’srelationship with preexisting documents on this subject, which are not extant, raises thepossibility that the function of the inscription was somewhat different than the communis opinio:the ‘Pistiros Inscription’ appears to have supplemented earlier regulation concerning Pistiros andto have attempted to limit the authority of an offi cial, possibly a Thracian royal, who exerciseddramatic power within Pistiros
Exploring the Origins of Deuterium Enrichments in Solar Nebular Organics
Deuterium-to-hydrogen (D/H) enrichments in molecular species provide clues
about their original formation environment. The organic materials in primitive
solar system bodies have generally higher D/H ratios and show greater D/H
variation when compared to D/H in solar system water. We propose this
difference arises at least in part due to 1) the availability of additional
chemical fractionation pathways for organics beyond that for water, and 2) the
higher volatility of key carbon reservoirs compared to oxygen. We test this
hypothesis using detailed disk models, including a sophisticated, new disk
ionization treatment with a low cosmic ray ionization rate, and find that disk
chemistry leads to higher deuterium enrichment in organics compared to water,
helped especially by fractionation via the precursors CHD/CH. We
also find that the D/H ratio in individual species varies significantly
depending on their particular formation pathways. For example, from
AU, CH can reach , while D/H in CHOH
remains locally unaltered. Finally, while the global organic D/H in our models
can reproduce intermediately elevated D/H in the bulk hydrocarbon reservoir,
our models are unable to reproduce the most deuterium-enriched organic
materials in the solar system, and thus our model requires some inheritance
from the cold interstellar medium from which the Sun formed.Comment: 11 pages, 7 figures, accepted for publication in Ap
The ancient heritage of water ice in the solar system
Identifying the source of Earth's water is central to understanding the
origins of life-fostering environments and to assessing the prevalence of such
environments in space. Water throughout the solar system exhibits
deuterium-to-hydrogen enrichments, a fossil relic of low-temperature,
ion-derived chemistry within either (i) the parent molecular cloud or (ii) the
solar nebula protoplanetary disk. Utilizing a comprehensive treatment of disk
ionization, we find that ion-driven deuterium pathways are inefficient,
curtailing the disk's deuterated water formation and its viability as the sole
source for the solar system's water. This finding implies that if the solar
system's formation was typical, abundant interstellar ices are available to all
nascent planetary systems.Comment: 33 pages, 7 figures including main text and supplementary materials.
Published in Scienc
Apollo, Ennodia, and fourth-century Thessaly
This paper explores the politics of cult in early fourth-century Thessaly, a period of prolonged stasis throughout the region. Two case studies are offered: The first explores Jason of Pherai’s planned expedition to Delphi in 370 and its potential impact on Thessalian corporate identity; the second reconstructs the role of Ennodia in the Pheraian tyrants’ attempts to win regional hegemony.Cet article étudie la politique cultuelle du début du ive siècle en Thessalie, une période de stasis prolongée dans la région. Deux études de cas sont proposées. La première aborde l’expédition planifiée par Jason de Phères à Delphes en 370 et son impact potentiel sur l’identité thessalienne. La seconde étude reconstruit le rôle d’Ennodia au sein des tentatives des tyrans pour imposer leur hégémonie à la région
Reentrant nu = 1 quantum Hall state in a two-dimensional hole system
We report the observation of a reentrant quantum Hall state at the Landau
level filling factor nu = 1 in a two-dimensional hole system confined to a
35-nm-wide (001) GaAs quantum well. The reentrant behavior is characterized by
a weakening and eventual collapse of the nu = 1 quantum Hall state in the
presence of a parallel magnetic field component B||, followed by a
strengthening and reemergence as B|| is further increased. The robustness of
the nu = 1 quantum Hall state during the transition depends strongly on the
charge distribution symmetry of the quantum well, while the magnitude of B||
needed to invoke the transition increases with the total density of the system
Even-denominator Fractional Quantum Hall Effect at a Landau Level Crossing
The fractional quantum Hall effect (FQHE), observed in two-dimensional (2D)
charged particles at high magnetic fields, is one of the most fascinating,
macroscopic manifestations of a many-body state stabilized by the strong
Coulomb interaction. It occurs when the filling factor () of the quantized
Landau levels (LLs) is a fraction which, with very few exceptions, has an odd
denominator. In 2D systems with additional degrees of freedom it is possible to
cause a crossing of the LLs at the Fermi level. At and near these crossings,
the FQHE states are often weakened or destroyed. Here we report the observation
of an unusual crossing of the two \emph{lowest-energy} LLs in high-mobility
GaAs 2D systems which brings to life a new \emph{even-denominator} FQHE
at
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