A New Look at the Asian Fertility Transition

The significance of the Asian fertility transition can hardly be overestimated. The relatively sanguine view of population growth expressed at the 1994 International Conference for Population and Development (ICPD) in Cairo was possible only because of the demographic events in Asia over the last 30 years. In 1965 Asian women were still bearing about six children. Even at current rates, today’s young women will give birth to half as many. This measure, namely the average number of live births over a reproductive lifetime, is called the total fertility rate. It has to be above 2— considerably above if mortality is still high—to achieve long-term population replacement. By 1995 East Asia, taken as a whole, exhibited a total fertility rate of 1.9. Elsewhere, Singapore was below long-term replacement, Thailand had just achieved it, and Sri Lanka was only a little above. The role of Asia in the global fertility transition is shown by estimates I made a few years ago for a World Bank Planning Meeting covering the first quarter of a century of the Asian transition [Caldwell (1993), p. 300]. Between 1965 and 1988 the world’s annual birth rate fell by 22 percent. In 1988 there would have been 40 million more births if there had been no decline from 1965 fertility levels. Of that total decline in the world’s births, almost 80 percent had been contributed by Asia, compared with only 10 percent by Latin America, nothing by Africa, and, unexpectedly, 10 percent by the high-income countries of the West. Indeed, 60 percent of the decline was produced by two countries, China and India, even though they constitute only 38 percent of the world’s population. They accounted, between them, for over threequarters of Asia’s fall in births.

Whales, dolphins, and porpoises of the western North Atlantic: a guide to their identification

This is an identification guide for cetaceans (whales, dolphins, and porpoises). It was designed to assist laypersons in identifying cetaceans encountered in the western North Atlantic Ocean and was intended for use by ongoing cetacean observer programs. This publication includes sections on identifying cetaceans at sea as well as stranded animals on shore. Species accounts are divided by body size and presence or lack of a dorsal fin. Appendices cover tags used on cetacean species; how to record and report cetacean observations at see and for stranded cetaceans; and a list of contacts for reporting cetacean strandings. (Document pdf contains 183 pages - file takes considerable time to open

Gravitational Wave - Gauge Field Oscillations

Gravitational waves propagating through a stationary gauge field transform into gauge field waves and back again. When multiple families of flavor-space locked gauge fields are present, the gravitational and gauge field waves exhibit novel dynamics. At high frequencies, the system behaves like coupled oscillators in which the gravitational wave is the central pacemaker. Due to energy conservation and exchange among the oscillators, the wave amplitudes lie on a multidimensional sphere, reminiscent of neutrino flavor oscillations. This phenomenon has implications for cosmological scenarios based on flavor-space locked gauge fields.Comment: 4 pages, 3 figures, 1 animation; replacement matches published versio

Cross-Correlation of Cosmological Birefringence with CMB Temperature

Theories for new particle and early-Universe physics abound with pseudo-Nambu-Goldstone fields that arise when global symmetries are spontaneously broken. The coupling of these fields to the Chern-Simons term of electromagnetism may give rise to cosmological birefringence (CB), a frequency-independent rotation of the linear polarization of photons as they propagate over cosmological distances. Inhomogeneities in the CB-inducing field may yield a rotation angle that varies across the sky. Here we note that such a spatially-varying birefringence may be correlated with the cosmic microwave background (CMB) temperature. We describe quintessence scenarios where this cross-correlation exists and other scenarios where the scalar field is simply a massless spectator field, in which case the cross-correlation does not exist. We discuss how the cross-correlation between CB-rotation angle and CMB temperature may be measured with CMB polarization. This measurement may improve the sensitivity to the CB signal, and it can help discriminate between different models of CB.Comment: 9 pages, 1 figure; submitted to PR

Recent data indicate that black women are at greater risk of severe morbidity and mortality from postpartum haemorrhage, both before and after adjusting for comorbidity.

Recent data indicate that black women are at greater risk of severe morbidity and mortality from postpartum haemorrhage, both before and after adjusting for comorbidity. Causes of increased risk of severe morbidity and mortality related to postpartum haemorrhage in black women in the USA are poorly understood and warrant further research. There is a need for tailored maternity services and improved access to care for women from ethnic minorities

The time evolution of cosmological redshift as a test of dark energy

The variation of the expansion rate of the Universe with time produces an evolution in the cosmological redshift of distant sources (for example quasar Lyman-$\alpha$ absorption lines), that might be directly observed by future ultra stable, high-resolution spectrographs (such as CODEX) coupled to extremely large telescopes (such as European Southern Observatory's Extremely Large Telescope, ELT). This would open a new window to explore the physical mechanism responsible for the current acceleration of the Universe. We investigate the evolution of cosmological redshift from a variety of dark energy models, and compare it with simulated data. We perform a Fisher matrix analysis and discuss the prospects for constraining the parameters of these models and for discriminating among competing candidates. We find that, because of parameter degeneracies, and of the inherent technical difficulties involved in this kind of observations, the uncertainties on parameter reconstruction can be rather large unless strong external priors are assumed. However, the method could be a valuable complementary cosmological tool, and give important insights on the dynamics of dark energy, not obtainable using other probes.Comment: 9 pages, 2 figures. Matching published versio