3,521 research outputs found
"Hegemonic Currencies during the Crisis: The Dollar versus the Euro in a Cartalist Perspective"
This paper suggests that the dollar is not threatened as the hegemonic international currency, and that most analysts are incapable of understanding the resilience of the dollar, not only because they ignore the theories of monetary hegemonic stability or what, more recently, has been termed the geography of money; but also as a result of an incomplete understanding of what a monetary hegemon does. The hegemon is not required to maintain credible macroeconomic policies (i.e., fiscally contractionary policies to maintain the value of the currency), but rather to provide an asset free of the risk of default. It is argued that the current crisis in Europe illustrates why the euro is not a real contender for hegemony in the near future.Dollar; Euro; International Currency
Massive Compact Halo Objects Viewed from a Cosmological Perspective: Contribution to the Baryonic Mass Density of the Universe
[Abridged] We estimate the contribution of Massive Compact Halo Objects
(Machos) and their stellar progenitors to the mass density of the Universe. If
the Machos that have been detected reside in the Halo of our Galaxy, then a
simple extrapolation of the Galactic population (out to 50 kpc) of Machos to
cosmic scales gives a cosmic density \rho_{Macho} = (1-5) \times 10^9 h \msun
\Mpc^{-3}, which in terms of the critical density corresponds to
. Such a mass density is comparable to
the baryon density implied by Big Bang Nucleosynthesis. If we take the central
values of the estimates, then Machos dominate the baryonic content of the
Universe today, with . However, the
cumulative uncertainties in the density determinations only require that
, where the fraction of
galaxies that contain Machos , and is the Hubble constant
in units of 100 km s Mpc. Our best estimate for
is hard to reconcile with the current best estimates of the baryonic content of
the intergalactic medium indicated by measurements of the Lyman-
forest. We explore the addition constraints that arise if the Machos are white
dwarfs as suggested by the present microlensing data. We discuss the challenges
this scenario presents at both the local and cosmic scales, emphasizing in
particular the constraints on the required mass budget and nucleosynthesis
products (particularly carbon).Comment: 18 pages, LaTeX, uses AASTeX macros. In press, New Astronomy
(submitted Jan. 20, 1998
The Segment Ontology: Bridging Music-generic and Domain-specific
Existing semantic representations of music analysis encapsulate narrow sub-domain concepts and are frequently scoped by the context of a particular MIR task. Segmentation is a crucial abstraction in the investigation of phenomena which unfold over time; we present a Segment Ontology as the backbone of an approach that models properties from the musicological domain independently from MIR implementations and their signal processing foundations, whilst maintaining an accurate and complete description of the relationships that link them. This framework provides two principal advantages which are explored through several examples: a layered separation of concerns that aligns the model with the needs of the users and systems that consume and produce the data; and the ability to link multiple analyses of differing types through transforms to and from the Segment axis
For Richer or For Poorer? Evidence from Indonesia, South Africa, Spain, and Venezuela
We analyze household income dynamics using longitudinal data from Indonesia, South Africa (KwaZulu-Natal), Spain and Venezuela. In all four countries, households with the lowest reported base-year income experienced the largest absolute income gains. This result is robust to reasonable amounts of measurement error in two of the countries. In three of the four countries, households with the lowest predicted base-year income experienced gains at least as large as their wealthier counterparts. Thus, with one exception, the empirical importance of cumulative advantage, poverty traps, and skill-biased technical change was no greater than structural or macroeconomic changes that favored initially poor households in these four countries
Primordial Nucleosynthesis and the Abundances of Beryllium and Boron
The ability to now make measurements of Be and B as well as put constraints
on \lisix\ abundances in metal-poor stars has led to a detailed reexamination
of Big Bang Nucleosynthesis in the A\groughly6 regime. The nuclear reaction
network has been significantly expanded with many new rates added. It is
demonstrated that although a number of reaction rates are poorly
determined, even with extreme values chosen, the standard homogeneous model is
unable to produce significant yields (Be/H and B/H when
abundances fit) above and the \liseven/\lisix\ ratio always exceeds 500.
We also preliminarily explore inhomogeneous models, such as those inspired by a
first order quark-hadron phase transition, where regions with high
neutron/proton ratios can allow some leakage up to . However models that
fit the abundances still seem to have difficulty in obtaining
significant yields.Comment: Plain TeX, 28 pages, 8 figures (not included, but available from
authors). UMN-TH-1020/9
High-fructose corn-syrup-sweetened beverage intake increases 5-hour breast milk fructose concentrations in lactating women
This study determined the effects of consuming a high-fructose corn syrup (HFCS)-sweetened beverage on breast milk fructose, glucose, and lactose concentrations in lactating women. At six weeks postpartum, lactating mothers (n = 41) were randomized to a crossover study to consume a commercially available HFCS-sweetened beverage or artificially sweetened control beverage. At each session, mothers pumped a complete breast milk expression every hour for six consecutive hours. The baseline fasting concentrations of breast milk fructose, glucose, and lactose were 5.0 ± 1.3 µg/mL, 0.6 ± 0.3 mg/mL, and 6.8 ± 1.6 g/dL, respectively. The changes over time in breast milk sugars were significant only for fructose (treatment × time, p < 0.01). Post hoc comparisons showed the HFCS-sweetened beverage vs. control beverage increased breast milk fructose at 120 min (8.8 ± 2.1 vs. 5.3 ± 1.9 µg/mL), 180 min (9.4 ± 1.9 vs. 5.2 ± 2.2 µg/mL), 240 min (7.8 ± 1.7 vs. 5.1 ± 1.9 µg/mL), and 300 min (6.9 ± 1.4 vs. 4.9 ± 1.9 µg/mL) (all p < 0.05). The mean incremental area under the curve for breast milk fructose was also different between treatments (14.7 ± 1.2 vs. −2.60 ± 1.2 µg/mL × 360 min, p < 0.01). There was no treatment × time interaction for breast milk glucose or lactose. Our data suggest that the consumption of an HFCS-sweetened beverage increased breast milk fructose concentrations, which remained elevated up to five hours post-consumption
Model Independent Predictions of Big Bang Nucleosynthesis from \he4 and \li7: Consistency and Implications
We examine in detail how BBN theory is constrained, and what predictions it
can make, when using only the most model-independent observational constraints.
We avoid the uncertainties and model-dependencies that necessarily arise when
solar neighborhood D and \he3 abundances are used to infer primordial D and
\he3 via chemical and stellar evolution models. Instead, we use \he4 and \li7,
thoroughly examining the effects of possible systematic errors in each. Via a
likelihood analysis, we find near perfect agreement between BBN theory and the
most model-independent data. Given this agreement, we then {\it assume} the
correctness of BBN to set limits on the single parameter of standard BBN, the
baryon-to-photon ratio, and to predict the primordial D and \he3 abundances. We
also repeat our analysis including recent measurements of D/H from quasar
absorption systems and find that the near perfect agreement between theory and
observation of the three isotopes, D, \he4 and \li7 is maintained. These
results have strong implications for the chemical and stellar evolution of the
light elements, in particular for \he3. In addition, our results (especially if
the D/H measurements are confirmed) have implications for the stellar depletion
of \li7. Finally, we set limits on the number \nnu\ of neutrino flavors, using
an analysis which carefully and systematically includes all available
experimental constraints. The value \nnu = 3.0 fits best with BBN and a 95\% CL
upper limit of \nnu \la 4 is established.Comment: 28 pages, latex, 10 ps figure
Chemical Abundance Constraints on White Dwarfs as Halo Dark Matter
We examine the chemical abundance constraints on a population of white dwarfs
in the Halo of our Galaxy. We are motivated by microlensing evidence for
massive compact halo objects (Machos) in the Galactic Halo, but our work
constrains white dwarfs in the Halo regardless of what the Machos are. We focus
on the composition of the material that would be ejected as the white dwarfs
are formed; abundance patterns in the ejecta strongly constrain white dwarf
production scenarios. Using both analytical and numerical chemical evolution
models, we confirm that very strong constraints come from Galactic Pop II and
extragalactic carbon abundances. We also point out that depending on the
stellar model, significant nitrogen is produced rather than carbon. The
combined constraints from C and N give from
comparison with the low C and N abundances in the Ly forest. We note,
however, that these results are subject to uncertainties regarding the
nucleosynthesis of low-metallicity stars. We thus investigate additional
constraints from D and He, finding that these light elements can be kept
within observational limits only for \Omega_{WD} \la 0.003 and for a white
dwarf progenitor initial mass function sharply peaked at low mass (2).
Finally, we consider a Galactic wind, which is required to remove the ejecta
accompanying white dwarf production from the galaxy. We show that such a wind
can be driven by Type Ia supernovae arising from the white dwarfs themselves,
but these supernovae also lead to unacceptably large abundances of iron. We
conclude that abundance constraints exclude white dwarfs as Machos. (abridged)Comment: Written in AASTeX, 26 pages plus 4 ps figure
- …
