The evolution and distribution of phage ST160 within Salmonella enterica serotype Typhimurium

Salmonellosis is an internationally important disease of mammals and birds. Unique epidemics in New Zealand in the recent past include two Salmonella serovars: Salmonella enterica subsp. enterica serovar Typhimurium definitive type (DT) 160 (S. Typhimurium DT160) and S. Brandenburg. Although not a major threat internationally, in New Zealand S. Typhimurium DT160 has been the most common serovar isolated from humans, and continues to cause significant losses in wildlife. We have identified DNA differences between the first New Zealand isolate of S. Typhimurium DT160 and the genome-sequenced strain, S. Typhimurium LT2. All the differences could be accounted for in one cryptic phage ST64B, and one novel P22-like phage, ST160. The majority of the ST160 genome is almost identical to phage SE1 but has two regions not found in SE1 which are identical to the P22-like phage ST64T, suggesting that ST160 evolved from SE1 via two recombination events with ST64T. All of the New Zealand isolates of DT160 were identical indicating the clonal spread of this particular Salmonella. Some overseas isolates of S. Typhimurium DT160 differed from the New Zealand strain and contained SE1 phage rather than ST160. ST160 was also identified in New Zealand isolates of S. Typhimurium DT74 and S. Typhimurium RDNC-April06 and in S. Typhimurium DT160 isolates from the USA. The emergence of S. Typhimurium DT160 as a significant pathogen in New Zealand is postulated to have occurred due to the sensitivity of the Salmonella strains to the ST160 phage when S. Typhimurium DT160 first arrived. © 2010 Cambridge University Press

Non-Linear Effects in Non-Kerr spacetimes

There is a chance that the spacetime around massive compact objects which are expected to be black holes is not described by the Kerr metric, but by a metric which can be considered as a perturbation of the Kerr metric. These non-Kerr spacetimes are also known as bumpy black hole spacetimes. We expect that, if some kind of a bumpy black hole exists, the spacetime around it should possess some features which will make the divergence from a Kerr spacetime detectable. One of the differences is that these non-Kerr spacetimes do not posses all the symmetries needed to make them integrable. We discuss how we can take advantage of this fact by examining EMRIs into the Manko-Novikov spacetime.Comment: 8 pages, 3 Figures; to appear in the proceedings of the conference "Relativity and Gravitation: 100 Years after Einstein in Prague" (2012

Population, sexual and reproductive health, rights and sustainable development: forging a common agenda.

This article suggests that sexual and reproductive health and rights activists seeking to influence the post-2015 international development paradigm must work with sustainable development advocates concerned with a range of issues, including climate change, environmental issues, and food and water security, and that a way of building bridges with these communities is to demonstrate how sexual and reproductive health and rights are relevant for these issues. An understanding of population dynamics, including urbanization and migration, as well as population growth, can help to clarify these links. This article therefore suggests that whether or not sexual and reproductive health and rights activists can overcome resistance to discussing "population", become more knowledgeable about other sustainable development issues, and work with others in those fields to advance the global sustainable development agenda are crucial questions for the coming months. The article also contends that it is possible to care about population dynamics (including ageing and problems faced by countries with a high proportion of young people) and care about human rights at the same time. It expresses concern that, if sexual and reproductive health and rights advocates do not participate in the population dynamics discourse, the field will be left free for those for whom respecting and protecting rights may be less of a priority

Constructing female entrepreneurship policy in the UK : is the US a relevant benchmark?

Successive UK governments have introduced a range of policy initiatives designed to encourage more women to start new firms. Underpinning these policies has been an explicit ambition for the UK to achieve similar participation rates as those in the US where it is widely reported that women own nearly half the stock of businesses. The data underlying these objectives are critically evaluated and it is argued that the definitions and measures of female enterprise used in the UK and the US restrict meaningful comparisons between the two. It is suggested that the expansion of female entrepreneurship in the US is historically and culturally specific to that country. UK policy goals should reflect the national socioeconomic context, while drawing upon good practice examples from a range of other countries. The paper concludes by discussing the economic and social viability of encouraging more women in the UK to enter self-employment without fully recognising the intensely competitive sectors in which they are often located

Nucleation of (4)R^{(4)}R Brane Universes

The creation of brane universes induced by a totally antisymmetric tensor living in a fixed background spacetime is presented, where a term involving the intrinsic curvature of the brane is considered. A canonical quantum mechanical approach employing Wheeler-DeWitt equation is done. The probability nucleation for the brane is calculated taking into account both an instanton method and a WKB approximation. Some cosmological implications arose from the model are presented.Comment: 19 pages, 2 figure

Stealth Branes

We discuss the brane world model of Dvali, Gabadadze and Porrati in which branes evolve in an infinite bulk and the brane curvature term is added to the action. If Z_2 symmetry between the two sides of the brane is not imposed, we show that the model admits the existence of "stealth branes" which follow the standard 4D internal evolution and have no gravitational effect on the bulk space. Stealth branes can nucleate spontaneosly in a Minkowski bulk. This process is described by the standard 4D quantum cosmology formalism with tunneling boundary conditions for the brane world wave function. The notorious ambiguity in the choice of boundary conditions is fixed in this case due to the presence of the embedding spacetime. We also point to some problematic aspects of models admitting stealth brane solutions.Comment: 24 pages; Final version, to appear in Phys. Rev. D. The discussion of "embeddability obstruction" is removed (thanks to Takahiro Tanaka who convinced us that there is no such obstruction

Surface gravity in dynamical spherically symmetric spacetimes

A definition of surface gravity at the apparent horizon of dynamical spherically symmetric spacetimes is proposed. It is based on a unique foliation by ingoing null hypersurfaces. The function parametrizing the hypersurfaces can be interpreted as the phase of a light wave uniformly emitted by some far-away static observer. The definition gives back the accepted value of surface gravity in the static case by virtue of its nonlocal character. Although the definition is motivated by the behavior of outgoing null rays, it turns out that there is a simple connection between the generalized surface gravity, the acceleration of any radially moving observer, and the observed frequency change of the infalling light signal. In particular, this gives a practical and simple method of how any geodesic observer can determine surface gravity by measuring only the redshift of the infalling light wave. The surface gravity can be expressed as an integral of matter field quantities along an ingoing null line, which shows that it is a continuous function along the apparent horizon. A formula for the area change of the apparent horizon is presented, and the possibility of thermodynamical interpretation is discussed. Finally, concrete expressions of surface gravity are given for a number of four-dimensional and two-dimensional dynamical black hole solutions.Comment: 35 pages, revtex, 3 figures included using eps

Unscrambling butterfly oogenesis

Background Butterflies are popular model organisms to study physiological mechanisms underlying variability in oogenesis and egg provisioning in response to environmental conditions. Nothing is known, however, about; the developmental mechanisms governing butterfly oogenesis, how polarity in the oocyte is established, or which particular maternal effect genes regulate early embryogenesis. To gain insights into these developmental mechanisms and to identify the conserved and divergent aspects of butterfly oogenesis, we analysed a de novo ovarian transcriptome of the Speckled Wood butterfly Pararge aegeria (L.), and compared the results with known model organisms such as Drosophila melanogaster and Bombyx mori. Results A total of 17306 contigs were annotated, with 30% possibly novel or highly divergent sequences observed. Pararge aegeria females expressed 74.5% of the genes that are known to be essential for D. melanogaster oogenesis. We discuss the genes involved in all aspects of oogenesis, including vitellogenesis and choriogenesis, plus those implicated in hormonal control of oogenesis and transgenerational hormonal effects in great detail. Compared to other insects, a number of significant differences were observed in; the genes involved in stem cell maintenance and differentiation in the germarium, establishment of oocyte polarity, and in several aspects of maternal regulation of zygotic development. Conclusions This study provides valuable resources to investigate a number of divergent aspects of butterfly oogenesis requiring further research. In order to fully unscramble butterfly oogenesis, we also now also have the resources to investigate expression patterns of oogenesis genes under a range of environmental conditions, and to establish their functio