628 research outputs found
[Book Review of] \u3cem\u3eThe Demographic Explosion-The Latin American Experience\u3c/em\u3e by Benjamin Viel
[Book Review of] \u3cem\u3eFruitful and Responsible Love\u3c/em\u3e, by Karol Wojtyla (Pope John Paul II)
[Book Review of] \u3cem\u3eLove, Fruitful and Responsible: Ten Years from\u3c/em\u3e Humanae Vitae, \u3cem\u3eProceedings of the International Congress Milan, June 21-25, 1978\u3c/em\u3e
Implementing ideal health policy in a fragile health system: the example of expanding the use of malaria rapid diagnostic tests in mainland Tanzania
Malaria confirmation before treatment provides an opportunity for improving the quality of malaria case management in endemic regions. However, increased coverage of this strategy is facing many organizational, logistical and technical challenges that threaten its success. Introducing an intervention with system-wide effect, such as the use of malaria rapid diagnostic tests in areas where malaria is still a public health problem, should be accompanied by system strengthening measures to better attain the goal of improving quality of care
Isolation and Monitoring of the Endohedral Metallofullerenes Y@C82 and Sc3@C82:On-Line Chromatographic Separation with EPR Detection
The direct coupling of high-performance liquid chromatography (HPLC) with on-line electron paramagnetic resonance (EPR) detection is demonstrated for monitoring separations of endohedral metallofullerenes (M@C2n). The HPLC-EPR approach readily permits detection of the paramagnetic species, such as Y@C82 and Sc3@C82, in the presence of the dominant empty-cage fullerenes (C60, C70) and diamagnetic metallofullerenes (e.g., M2@C2n). The results indicate that on-line EPR provides a noninvasive, selective detector for HPLC metallofullerene separations that is readily adaptable to air-sensitive and/or labile compounds. Specifically, the âEPR-activeâ metallofullerenes, Y@C82 and Sc3@C82, are selectively monitored on-line for an initial separation of the metallofullerene fraction from the dominant empty-cage fullerenes utilizing a combination of polystyrene columns. This preparative âcleanupâ procedure is followed by HPLC-EPR separation and monitoring of Y@C82 and Sc3@C82 species using a selective tripodal Ď-acidic-phase column (Trident-Tri-DNP) for the final stages of isolation
Theoretical Study of One-dimensional Chains of Metal Atoms in Nanotubes
Using first-principles total-energy pseudopotential calculations, we have
studied the properties of chains of potassium and aluminum in nanotubes. For BN
tubes, there is little interaction between the metal chains and the tubes, and
the conductivity of these tubes is through carriers located at the inner part
of the tube. In contrast, for small radius carbon nanotubes, there are two
types of interactions: charge-transfer (dominant for alkali atoms) leading to
strong ionic cohesion, and hybridization (for multivalent metal atoms)
resulting in a smaller cohesion. For Al-atomic chains in carbon tubes, we show
that both effects contribute. New electronic properties related to these
confined atomic chains of metal are analyzed.Comment: 12 pages + 3 figure
Willingness to Pay for Malaria Insurance: A Case Study of Households in Ghana Using the Contingent Valuation Method
This paper reports the results of a study which estimated household willingness to participate in a malaria insurance scheme in Ghana using the contingent valuation method. The study was conducted in two communities representing rural and urban areas of the country. The results indicate a high level of support for the scheme, reflecting the social and economic importance of the disease. The level of premium that households were willing to pay was significantly influenced by income, years of formal education, occupation type and number of children in the household. The results show that an insurance programme which encourages 'pre-saving' towards treatment fees could curtail self-medication and household decisions to delay seeking care, thereby promoting early and efficacious treatment of malaria
Size Effects in Carbon Nanotubes
The inter-shell spacing of multi-walled carbon nanotubes was determined by
analyzing the high resolution transmission electron microscopy images of these
nanotubes. For the nanotubes that were studied, the inter-shell spacing
is found to range from 0.34 to 0.39 nm, increasing with
decreasing tube diameter. A model based on the results from real space image
analysis is used to explain the variation in inter-shell spacings obtained from
reciprocal space periodicity analysis. The increase in inter-shell spacing with
decreased nanotube diameter is attributed to the high curvature, resulting in
an increased repulsive force, associated with the decreased diameter of the
nanotube shells.Comment: 4 pages. RevTeX. 4 figure
Quantum Communication
Quantum communication, and indeed quantum information in general, has changed
the way we think about quantum physics. In 1984 and 1991, the first protocol
for quantum cryptography and the first application of quantum non-locality,
respectively, attracted a diverse field of researchers in theoretical and
experimental physics, mathematics and computer science. Since then we have seen
a fundamental shift in how we understand information when it is encoded in
quantum systems. We review the current state of research and future directions
in this new field of science with special emphasis on quantum key distribution
and quantum networks.Comment: Submitted version, 8 pg (2 cols) 5 fig
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