268 research outputs found
Beginning of Viniculture in France
Chemical analyses of ancient organic compounds absorbed into the pottery fabrics of imported Etruscan amphoras (ca. 500-475 B.C.) and into a limestone pressing platform (ca. 425-400 B.C.) at the ancient coastal port site of Lattara in southern France provide the earliest biomolecular archaeological evidence for grape wine and viniculture from this country, which is crucial to the later history of wine in Europe and the rest of the world. The data support the hypothesis that export of wine by ship from Etruria in central Italy to southern Mediterranean France fueled an ever-growing market and interest in wine there, which, in turn, as evidenced by the winepress, led to transplantation of the Eurasian grapevine and the beginning of a Celtic industry in France. Herbal and pine resin additives to the Etruscan wine point to the medicinal role of wine in antiquity, as well as a means of preserving it during marine transport
Latitude-dependent effects in the stellar wind of Eta Carinae
The Homunculus reflection nebula around eta Carinae provides a rare
opportunity to observe the spectrum of a star from multiple latitudes. We
present STIS spectra of several positions in the Homunculus, showing directly
that eta Car has an aspherical stellar wind. P Cygni absorption in Balmer lines
depends on latitude, with high velocities and strong absorption near the poles.
Stronger absorption at high latitudes is surprising, and it suggests higher
mass flux toward the poles, perhaps resulting from radiative driving with
equatorial gravity darkening on a rotating star. Reflected profiles of He I
lines are more puzzling, offering clues to the wind geometry and ionization
structure. During eta Car's high-excitation state in March 2000, the wind was
fast and dense at the poles, with higher ionization at low latitudes.
Older STIS data obtained since 1998 reveal that this global stellar-wind
geometry changes during eta Car's 5.5 year cycle, and may suggest that this
star's spectroscopic events are shell ejections. Whether or not a companion
star triggers these outbursts remains ambiguous. The most dramatic changes in
the wind occur at low latitudes, while the dense polar wind remains relatively
undisturbed during an event. The apparent stability of the polar wind also
supports the inferred bipolar geometry. The wind geometry and its variability
have critical implications for understanding the 5.5 year cycle and long-term
variability, but do not provide a clear alternative to the binary hypothesis
for generating eta Car's X-rays.Comment: Accepted by ApJ. To appear in March 2003. Based on PhD Thesis,
Minnesota 200
Observations of the Crab Nebula and its pulsar in the far-ultraviolet and in the optical
We present HST/STIS far-UV observations of the Crab nebula and its pulsar.
Broad, blueshifted absorption arising in the nebula is seen in C IV 1550,
reaching about 2500 km/s. This can be interpreted as evidence for a fast outer
shell, and we adopt a spherically symmetric model to constrain the properties
of this. We find that the density appears to decrease outward in the shell. A
lower limit to the mass is 0.3 solar masses with an accompanying kinetic energy
of 1.5EE{49} ergs. A massive 10^{51} erg shell cannot be excluded, but is less
likely if the density profile is much steeper than R^{-4} and the velocity is
<6000 km/s. The observations cover the region 1140-1720 A. With the time-tag
mode of the spectrograph we obtain the pulse profile. It is similar to that in
the near-UV, although the primary peak is marginally narrower. Together with
the near-UV data, and new optical data from NOT, our spectrum of the pulsar
covers the entire region from 1140-9250 A. Dereddening the spectrum gives a
flat spectrum for E(B-V)=0.52, R=3.1. This dereddened spectrum of the Crab
pulsar can be fitted by a power law with spectral index alpha_{\nu} = 0.11 +/-
0.04. The main uncertainty is the amount and characteristics of the interstel-
lar reddening, and we have investigated the dependence of \alpha_{\nu} on
E(B-V) and R. In the extended emission covered by our 25" x 0.5" slit in the
far-UV, we detect C IV 1550 and He II 1640 emission lines from the Crab nebula.
Several interstellar absorption lines are detected toward the pulsar. The Ly
alpha absorption indicates a column density of 3.0+/-0.5\EE{21} cm^{-2} of
neutral hydrogen, which agrees well with our estimate of E(B-V)=0.52 mag. Other
lines show no evidence of severe depletion of metals in atomic gas.Comment: 18 pages emulateapj style, including 10 figures. ApJ, accepte
X-ray Spectral Variation of Eta Carinae through the 2003 X-ray Minimum
We report the results of an X-ray observing campaign on the massive, evolved
star Eta Carinae, concentrating on the 2003 X-ray minimum as seen by the
XMM-Newton observatory. These are the first spatially-resolved X-ray monitoring
observations of the stellar X-ray spectrum during the minimum. The hard X-ray
emission, believed to be associated with the collision of Eta Carinae's wind
with the wind from a massive companion star, varied strongly in flux on
timescales of days, but not significantly on timescales of hours. The lowest
X-ray flux in the 2-10 keV band seen by XMM-Newton was only 0.7% of the maximum
seen by RXTE just before the X-ray minimum. The slope of the X-ray continuum
above 5 keV did not vary in any observation, which suggests that the electron
temperature of the hottest plasma associated with the stellar source did not
vary significantly at any phase. Through the minimum, the absorption to the
stellar source increased by a factor of 5-10 to NH ~3-4E23 cm-2. The thermal Fe
XXV emission line showed significant excesses on both the red and blue sides of
the line outside the minimum and exhibited an extreme red excess during the
minimum. The Fe fluorescence line at 6.4 keV increased in equivalent width from
100 eV outside the minimum to 200 eV during the minimum. From these observed
features, we discuss two possible causes of the X-ray minimum; the eclipse of
the X-ray plasma and an intrinsic fading of the X-ray emissivity. The drop in
the colliding wind X-ray emission also revealed the presence of an additional
X-ray component which exhibited no variation on timescales of weeks to years.
This component may be produced by the collision of high speed outflows at v
\~1000-2000 km s-1 from Eta Carinae with ambient gas within a few thousand AU
from the star.Comment: 35 pages, 14 figures, accepted for publication in Ap
Combinatorial targeting and discovery of ligand-receptors in organelles of mammalian cells
Phage display screening allows the study of functional protein–protein interactions at the cell surface, but investigating intracellular organelles remains a challenge. Here we introduce internalizing-phage libraries to identify clones that enter mammalian cells through a receptor-independent mechanism and target-specific organelles as a tool to select ligand peptides and identify their intracellular receptors. We demonstrate that penetratin, an antennapedia-derived peptide, can be displayed on the phage envelope and mediate receptor-independent uptake of internalizing phage into cells. We also show that an internalizing-phage construct displaying an established mitochondria-specific localization signal targets mitochondria, and that an internalizing-phage random peptide library selects for peptide motifs that localize to different intracellular compartments. As a proof-of-concept, we demonstrate that one such peptide, if chemically fused to penetratin, is internalized receptor-independently, localizes to mitochondria, and promotes cell death. This combinatorial platform technology has potential applications in cell biology and drug development
Neoliberalism and the Far-Right: A Contradictory Embrace
This article examines the contradictory relationship between neoliberalism and the politics of the far-right. It seeks to identify and explain the divergence of the ‘economic’ and the social/cultural spheres under neoliberalism (notably in articulations of race and class and the ‘politics of whiteness’) and how such developments play out in the politics of the contemporary far-right. We also seek to examine the degree to which the politics of the far-right pose problems for the consolidation and long-term stabilization of neoliberalism, through acting as a populist source of pressure on the conservative-right and tapping into sources of alienation amongst déclassé social layers. Finally, we locate the politics of the far-right within the broader atrophying of political representation and accountability of the neoliberal era with respect to the institutional and legal organization of neoliberalism at the international level, as most obviously highlighted in the ongoing crisis of the EU and Eurozone
Antiangiogenic Activity of 2-Deoxy-D-Glucose
During tumor angiogenesis, endothelial cells (ECs) are engaged in a number of energy consuming biological processes, such as proliferation, migration, and capillary formation. Since glucose uptake and metabolism are increased to meet this energy need, the effects of the glycolytic inhibitor 2-deoxy-D-glucose (2-DG) on in vitro and in vivo angiogenesis were investigated.In cell culture, 2-DG inhibited EC growth, induced cytotoxicity, blocked migration, and inhibited actively forming but not established endothelial capillaries. Surprisingly, 2-DG was a better inhibitor of these EC properties than two more efficacious glycolytic inhibitors, 2-fluorodeoxy-D-glucose and oxamate. As an alternative to a glycolytic inhibitory mechanism, we considered 2-DG's ability to interfere with endothelial N-linked glycosylation. 2-DG's effects were reversed by mannose, an N-linked glycosylation precursor, and at relevant concentrations 2-DG also inhibited synthesis of the lipid linked oligosaccharide (LLO) N-glycosylation donor in a mannose-reversible manner. Inhibition of LLO synthesis activated the unfolded protein response (UPR), which resulted in induction of GADD153/CHOP and EC apoptosis (TUNEL assay). Thus, 2-DG's effects on ECs appeared primarily due to inhibition of LLOs synthesis, not glycolysis. 2-DG was then evaluated in two mouse models, inhibiting angiogenesis in both the matrigel plug assay and the LH(BETA)T(AG) transgenic retinoblastoma model.In conclusion, 2-DG inhibits endothelial cell angiogenesis in vitro and in vivo, at concentrations below those affecting tumor cells directly, most likely by interfering with N-linked glycosylation rather than glycolysis. Our data underscore the importance of glucose metabolism on neovascularization, and demonstrate a novel approach for anti-angiogenic strategies
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