The Production of Alternative Urban Spaces An International Dialogue

Alternative urban spaces across civic, private, and public spheres emerge in response to the great challenges that urban actors are currently confronted with. Labour markets are changing rapidly, the availability of affordable housing is under intensifying pressure, and public spaces have become battlegrounds of urban politics. This edited collection brings together contributors in order to spark an international dialogue about the production of alternative urban spaces through a threefold exploration of alternative spaces of work, dwelling, and public life. Seeking out and examining existing alternative urban spaces, the authors identify the elements that provide opportunities to create radically different futures for the world's urban spaces. This volume is the culmination of an international search for alternative practices to dominant modes of capitalist urbanisation, bringing together interdisciplinary, empirically grounded chapters from hot spots in disparate cities around the world. Offering a multidisciplinary perspective, The Production of Alternative Urban Spaces will be of great interest to academics working across the fields of urban sociology, human geography, anthropology, political science, and urban planning. It will also be indispensable to any postgraduate students engaged in urban and regional studies

Is the Armington Elasticity Really Constant across Importers?

This paper shows that the Armington elasticity, which refers to both the elasticity of substitution across goods and the price elasticity of demand under the assumption of a large number of varieties, systematically changes from one importer country to another in an international trade context. Then a natural question to ask is "What determines the Armington elasticity?" The answer comes from the distinction between the elasticity of demand with respect to the destination price (i.e., the Armington elasticity) and the elasticity of demand with respect to the source price. Under additive trade costs, it is shown that the elasticity of demand with respect to the destination price is equal to the sum of the elasticity of demand with respect to the source price and the elasticity of demand with respect to the trade costs. The empirical results using the United States export data at the state level support this relation; hence, it is more likely to have a constant elasticity of demand with respect to the source price rather than a constant Armington elasticity under additive trade costs. In terms of policy implications, the constant Armington elasticity undervalues the effects of a policy change around 3 or 4 times compared to the importer-specific Armington elasticities

Models for Type I X-Ray Bursts with Improved Nuclear Physics

Multi-zone models of Type I X-ray bursts are presented that use an adaptive nuclear reaction network of unprecedented size, up to 1300 isotopes. Sequences of up to 15 bursts are followed for two choices of accretion rate and metallicity. At 0.1 Eddington (and 0.02 Eddington for low metallicity), combined hydrogen-helium flashes occur. The rise times, shapes, and tails of these light curves are sensitive to the efficiency of nuclear burning at various waiting points along the rp-process path and these sensitivities are explored. The bursts show "compositional inertia", in that their properties depend on the fact that accretion occurs onto the ashes of previous bursts which contain left-over hydrogen, helium and CNO nuclei. This acts to reduce the sensitivity of burst properties to metallicity. For the accretion rates studied, only the first anomalous burst in one model produces nuclei as heavy as A=100, other bursts make chiefly nuclei with A~64. The amount of carbon remaining after hydrogen-helium bursts is typically <1% by mass, and decreases further as the ashes are periodically heated by subsequent bursts. At the lower accretion rate of 0.02 Eddington and solar metallicity, the bursts ignite in a hydrogen-free helium layer. At the base of this layer, up to 90% of the helium has already burned to carbon prior to the unstable ignition. These helium-ignited bursts have briefer, brighter light curves with shorter tails, very rapid rise times (<0.1 s), and ashes lighter than the iron group.Comment: Submitted to the Astrophysical Journal (42 pages; 27 figures

The cooling rate of neutron stars after thermonuclear shell flashes

Thermonuclear shell flashes on neutron stars are detected as bright X-ray bursts. Traditionally, their decay is modeled with an exponential function. However, this is not what theory predicts. The expected functional form for luminosities below the Eddington limit, at times when there is no significant nuclear burning, is a power law. We tested the exponential and power-law functional forms against the best data available: bursts measured with the high-throughput Proportional Counter Array (PCA) on board the Rossi X-ray Timing Explorer. We selected a sample of 35 'clean' and ordinary (i.e., shorter than a few minutes) bursts from 14 different neutron stars that 1) show a large dynamic range in luminosity, 2) are the least affected by disturbances by the accretion disk and 3) lack prolonged nuclear burning through the rp-process. We find indeed that for every burst a power law is a better description than an exponential function. We also find that the decay index is steep, 1.8 on average, and different for every burst. This may be explained by contributions from degenerate electrons and photons to the specific heat capacity of the ignited layer and by deviations from the Stefan-Boltzmann law due to changes in the opacity with density and temperature. Detailed verification of this explanation yields inconclusive results. While the values for the decay index are consistent, changes of it with the burst time scale, as a proxy of ignition depth, and with time are not supported by model calculations.Comment: 10 pages, 7 figures, recommended for publication in A&

Nucleosynthesis in Early Neutrino Driven Winds

Nucleosynthesis in early neutrino winds is investigated. Presented is a brief overview of two recent problems of supernova nucleosynthesis. In the first part we investigate the effect of nuclear parameters on the synthesis of Mo92 and Mo94. Based on recent experimental results, we find that the proton rich winds of the model investigated here can not be the source of solar Mo92 and Mo94. In the second part we investigate the nucleosynthesis from neutron rich bubbles and show that they do not contribute to the overall nucleosynthesis.Comment: 4 pages, 4 figures, proceedings for CNR 2007 Compound-Nuclear Reactions and Related Topics Worksho

Stillbirth maternity care measurement and associated factors in population-based surveys: EN-INDEPTH study.

BACKGROUND: Household surveys remain important sources of maternal and child health data, but until now, standard surveys such as Demographic and Health Surveys (DHS) have not collected information on maternity care for women who have experienced a stillbirth. Thus, nationally representative data are lacking to inform programmes to address the millions of stillbirths which occur annually. METHODS: The EN-INDEPTH population-based survey of women of reproductive age was undertaken in five Health and Demographic Surveillance System sites in Bangladesh, Ethiopia, Ghana, Guinea-Bissau and Uganda (2017-2018). All women answered a full birth history with additional questions on pregnancy losses (FBH+) or full pregnancy history (FPH). A sub-sample, including all women reporting a recent stillbirth or neonatal death, was asked additional maternity care questions. These were evaluated using descriptive measures. Associations between stillbirth and maternal socio-demographic characteristics, babies' characteristics and maternity care use were assessed using a weighted logistic regression model for women in the FBH+ group. RESULTS: A total of 15,591 women reporting a birth since 1 January 2012 answered maternity care questions. Completeness was very high (> 99%), with similar proportions of responses for both live and stillbirths. Amongst the 14,991 births in the FBH+ group, poorer wealth status, higher parity, large perceived baby size-at-birth, preterm or post-term birth, birth in a government hospital compared to other locations and vaginal birth were associated with increased risk of stillbirth after adjusting for potential confounding factors. Regarding association with reported postnatal care, women with a stillbirth were more likely to report hospital stays of > 1 day. However, women with a stillbirth were less likely to report having received a postnatal check compared to those with a live birth. CONCLUSIONS: Women who had experienced stillbirth were able to respond to questions about pregnancy and birth, and we found no reason to omit questions to these women in household surveys. Our analysis identified several potentially modifiable factors associated with stillbirth, adding to the evidence-base for policy and action in low- and middle-income contexts. Including these questions in DHS-8 would lead to increased availability of population-level data to inform action to end preventable stillbirths

Birthweight data completeness and quality in population-based surveys: EN-INDEPTH study.

BACKGROUND: Low birthweight (< 2500 g) is an important marker of maternal health and is associated with neonatal mortality, long-term development and chronic diseases. Household surveys remain an important source of population-based birthweight information, notably Demographic and Health Surveys (DHS) and UNICEF's Multiple Indicator Cluster Surveys (MICS); however, data quality concerns remain. Few studies have addressed how to close these gaps in surveys. METHODS: The EN-INDEPTH population-based survey of 69,176 women was undertaken in five Health and Demographic Surveillance System sites (Matlab-Bangladesh, Dabat-Ethiopia, Kintampo-Ghana, Bandim-Guinea-Bissau, IgangaMayuge-Uganda). Responses to existing DHS/MICS birthweight questions on 14,411 livebirths were analysed and estimated adjusted odds ratios (aORs) associated with reporting weighing, birthweight and heaping reported. Twenty-eight focus group discussions with women and interviewers explored barriers and enablers to reporting birthweight. RESULTS: Almost all women provided responses to birthweight survey questions, taking on average 0.2 min to answer. Of all babies, 62.4% were weighed at birth, 53.8% reported birthweight and 21.1% provided health cards with recorded birthweight. High levels of heterogeneity were observed between sites. Home births and neonatal deaths were less likely to be weighed at birth (home births aOR 0.03(95%CI 0.02-0.03), neonatal deaths (aOR 0.19(95%CI 0.16-0.24)), and when weighed, actual birthweight was less likely to be known (aOR 0.44(95%CI 0.33-0.58), aOR 0.30(95%CI 0.22-0.41)) compared to facility births and post-neonatal survivors. Increased levels of maternal education were associated with increases in reporting weighing and knowing birthweight. Half of recorded birthweights were heaped on multiples of 500 g. Heaping was more common in IgangaMayuge (aOR 14.91(95%CI 11.37-19.55) and Dabat (aOR 14.25(95%CI 10.13-20.3) compared to Bandim. Recalled birthweights were more heaped than those recorded by card (aOR 2.59(95%CI 2.11-3.19)). A gap analysis showed large missed opportunity between facility birth and known birthweight, especially for neonatal deaths. Qualitative data suggested that knowing their baby's weight was perceived as valuable by women in all sites, but lack of measurement and poor communication, alongside social perceptions and spiritual beliefs surrounding birthweight, impacted women's ability to report birthweight. CONCLUSIONS: Substantial data gaps remain for birthweight data in household surveys, even amongst facility births. Improving the accuracy and recording of birthweights, and better communication with women, for example using health cards, could improve survey birthweight data availability and quality