1,495 research outputs found
Investigations on the consumption of sugar by South African populations
By means of questionnaires, appropriate for both individuals and households, surveys of sugar intake have been carried out in the Transvaal on groups of South African Whites, Indians, Malays, Coloureds, and Bantu. Inquiries concerned groups in urban and rural areas, and in different socio-economic circumstances. In Whites the consumptions per capita resemble data published in the United Kingdom. Mean intakes, in round figures, range from 80 to 100 g per day for those in the higher socio-economic groups, to 120 - 140 g for those in lower-income groups. For Indians the mean consumptions, 70 - 90 g, are less than the intakes of Whites, and slightly less than the limited data on Coloureds and Malays. The Coloureds and Malays were not extensively investigated; the mean intakes of about 90 g are lower than those of Whites in similar economic circumstances. Among the rural groups of Bantu studied, mean intakes range from 65 to 75 g per day, while in urban areas ranges are greater, 55 - 85 g per day. Miscellaneous findings were that males consume more sugar than females; intake rises with age, but falls off in late middle-age; intake falls with increase in family size; and among Whites, intake tends to decrease with rise in privilege (this change is not yet apparent in non-White groups). In the future, sugar intake will certainly increase in the non-White populations, particularly the Bantu
Probing the Galactic Dark Matter Mass Funtion Using Microlensing and Direct Searches
If compact baryonic objects contribute significantly to the dark matter in
our Galaxy, their mass function will present vital clues for galaxy formation
theories and star formation processes in the early Universe. Here we discuss
what one might expect to learn about the mass function of Galactic dark matter
from microlensing and from direct searches in the infrared and optical
wavebands. Current microlensing results from the \eros\/ collaboration already
constrain halo mass functions which extend below 10^{-4}~\sm, whilst recent
\hst\/ observations place strong constraints on disc and halo dark matter mass
functions extending above 0.1~\sm. Infrared observations should either detect
or constrain objects larger than 0.01~\sm in the near future. Objects below
0.01~\sm should be detectable through microlensing, although the prospects of
determining their mass function depend critically on a number of factors.Comment: uuencoded, gzipped postscript file (4 pages). Postscript file
(massfunc.ps) can also be obtained via anonymous ftp to 138.37.48.101 in dir
/pub/ejk/ir+lens. Based on a talk presented at the conference "Trends in
Astroparticle Physics", Stockholm, Sweden, 22-25 September. To be published
in Nucl. Phys. B Proceedings Supplemen
Distribution of Mesoscale Convective Complex Rainfall in the United States
Several annual mesoscale convective complex (MCC) summaries have been compiled since Maddox strictly
defined their criteria in 1980. These previous studies have largely been independent of each other and therefore
have not established the extended spatial and temporal patterns associated with these large, quasi-circular, and,
typically, severe convective systems. This deficiency is primarily due to the difficulty of archiving enough
satellite imagery to accurately record each MCC based on Maddox’s criteria. Consequently, this study utilizes
results from each of the MCC summaries compiled between 1978 and 1999 for the United States in order to
develop a more complete climatology, or description of long-term means and interannual variation, of these
storms. Within the 22-yr period, MCC summaries were compiled for a total of 15 yr. These 15 yr of MCC data
are employed to establish estimated tracks for all MCCs documented and, thereafter, are utilized to determine
MCC populations on a monthly, seasonal, annual, and multiyear basis. Subsequent to developing an extended
climatology of MCCs, the study ascertains the spatial and temporal patterns of MCC rainfall and determines
the precipitation contributions made by MCCs over the central and eastern United States. Results indicate that
during the warm season, significant portions of the Great Plains receive, on average, between 8% and 18% of
their total precipitation from MCC rainfall. However, there is large yearly and even monthly variability in the
location and frequency of MCC events that leads to highly variable precipitation contributions
Long and short range magnetism in the frustrated double perovskite Ba2MnWO6
The structural and magnetic properties of the face-centered cubic double perovskite Ba2MnWO6 were investigated using neutron powder diffraction, DC-magnetometry, muon spin relaxation and inelastic neutron scattering. Ba2MnWO6 undergoes Type II long-range antiferromagnetic ordering at a Neel temperature of 8(1) K with a frustration index, f = 8. Inelastic neutron scattering was used to identify the magnetic coupling constants J1 and J2, which were found to equal -0.080 meV and -0.076 meV respectively. This indicated that both of the magnetic coupling constants were antiferromagnetic with similar magnitudes, which is in contrast to other known 3d metal double perovskites Ba2MWO6. Above the Neel temperature, muon spin relaxation measurements and inelastic neutron scattering techniques identify a short-range correlated magnetic state that is similar to that observed in the archetypical face-centered cubic lattice antiferromagnet MnO
Electromagnetic proton form factors in large QCD
The electromagnetic form factors of the proton are obtained using a
particular realization of QCD in the large limit (),
which sums up the infinite number of zero-width resonances to yield an Euler's
Beta function (Dual-). The form factors and
, as well as agree very well with reanalyzed space-like
data in the whole range of momentum transfer. In addition, the predicted ratio
is in good agreement with recent polarization transfer
measurements at Jefferson Lab.Comment: 10 page
The PL calibration for Milky Way Cepheids and its implications for the distance scale
The rationale behind recent calibrations of the Cepheid PL relation using the
Wesenheit formulation is reviewed and reanalyzed, and it is shown that recent
conclusions regarding a possible change in slope of the PL relation for
short-period and long-period Cepheids are tied to a pathological distribution
of HST calibrators within the instability strip. A recalibration of the
period-luminosity relation is obtained using Galactic Cepheids in open clusters
and groups, the resulting relationship, described by log L/L_sun =
2.415(+-0.035) + 1.148(+-0.044)log P, exhibiting only the moderate scatter
expected from color spread within the instability strip. The relationship is
confirmed by Cepheids with HST parallaxes, although without the need for
Lutz-Kelker corrections, and in general by Cepheids with revised Hipparcos
parallaxes, albeit with concerns about the cited precisions of the latter. A
Wesenheit formulation of Wv = -2.259(+-0.083) - 4.185(+-0.103)log P for
Galactic Cepheids is tested successfully using Cepheids in the inner regions of
the galaxy NGC 4258, confirming the independent geometrical distance
established for the galaxy from OH masers. Differences between the extinction
properties of interstellar and extragalactic dust may yet play an important
role in the further calibration of the Cepheid PL relation and its application
to the extragalactic distance scale.Comment: Accepted for Publication (Astrophysics & Space Science
Gravitational waves in non-singular string cosmologies
We study the evolution of tensor metric fluctuations in a class of
non-singular models based on the string effective action, by including in the
perturbation equation the higher-derivative and loop corrections needed to
regularise the background solutions. We discuss the effects of such
higher-order corrections on the final graviton spectrum, and we compare the
results of analytical and numerical computations.Comment: 24 pages, 7 figure
Schlieren Studies of Compressibility Effects on Dynamic Stall of Airfoils in Transient Pitching Motion
Compressibility effects on the flowfield of an airfoil
executing rapid transient pitching motion from 0 - 60 degrees
over a wide range of Mach numbers and pitching
rates were studied using a stroboscopic schlieren flow visualization
technique. The studies have led to the first direct
experiments] documentation of multiple shocks on the
airfoil upper surface flow for certain conditions. Also, at
low Mach numbers, additional coherent vortical structures
were found to be present along with the dynamic stall vortex,
whereas at higher Mach numbers, the flow was dominated
by a single vortex. The delineating Mach number
for significant compressibility effects was 0.3 and the dynamic
stall process was accelerated by increasing the Mach
number above that value. Increasing the pitch rate monotonically
delayed stall to angles of attack as large as 27
degrees.AFOSR-MIPR-87-0029 and 88-0010NAVAIRAR
Multi-Periodic Oscillations in Cepheids and RR Lyrae-Type Stars
Classical Cepheids and RR Lyrae-type stars are usually considered to be
textbook examples of purely radial, strictly periodic pulsators. Not all the
variables, however, conform to this simple picture. In this review I discuss
different forms of multi-periodicity observed in Cepheids and RR Lyrae stars,
including Blazhko effect and various types of radial and nonradial multi-mode
oscillations.Comment: Proceedings of the 20th Stellar Pulsation Conference Series: "Impact
of new instrumentation & new insights in stellar pulsations", 5-9 September
2011, Granada, Spai
Endemic fungal infections in solid organ and hematopoietic cell transplant recipients enrolled in the Transplant‐Associated Infection Surveillance Network ( TRANSNET )
Background Invasive fungal infections are a major cause of morbidity and mortality among solid organ transplant ( SOT ) and hematopoietic cell transplant ( HCT ) recipients, but few data have been reported on the epidemiology of endemic fungal infections in these populations. Methods Fifteen institutions belonging to the Transplant‐Associated Infection Surveillance Network prospectively enrolled SOT and HCT recipients with histoplasmosis, blastomycosis, or coccidioidomycosis occurring between March 2001 and March 2006. Results A total of 70 patients (64 SOT recipients and 6 HCT recipients) had infection with an endemic mycosis, including 52 with histoplasmosis, 9 with blastomycosis, and 9 with coccidioidomycosis. The 12‐month cumulative incidence rate among SOT recipients for histoplasmosis was 0.102%. Occurrence of infection was bimodal; 28 (40%) infections occurred in the first 6 months post transplantation, and 24 (34%) occurred between 2 and 11 years post transplantation. Three patients were documented to have acquired infection from the donor organ. Seven SOT recipients with histoplasmosis and 3 with coccidioidomycosis died (16%); no HCT recipient died. Conclusions This 5‐year multicenter prospective surveillance study found that endemic mycoses occur uncommonly in SOT and HCT recipients, and that the period at risk extends for years after transplantation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106980/1/tid12186.pd
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