Immune cells and preterm labour:do invariant NKT cells hold the key?

We have developed our original made-to-measure (M2M) algorithm, PRIMAL, with the aim of modelling the Galactic disc from upcoming Gaia data. From a Milky Way like N-body disc galaxy simulation, we have created mock Gaia data using M0III stars as tracers, taking into account extinction and the expected Gaia errors. In PRIMAL, observables calculated from the N-body model are compared with the target stars, at the position of the target stars. Using PRIMAL, the masses of the N-body model particles are changed to reproduce the target mock data, and the gravitational potential is automatically adjusted by the changing mass of the model particles. We have also adopted a new resampling scheme for the model particles to keep the mass resolution of the N-body model relatively constant. We have applied PRIMAL to this mock Gaia data and we show that PRIMAL can recover the structure and kinematics of a Milky Way like barred spiral disc, along with the apparent bar structure and pattern speed of the bar despite the galactic extinction and the observational errors

Inter-species horizontal transfer resulting in core-genome and niche-adaptive variation within Helicobacter pylori

Background Horizontal gene transfer is central to evolution in most bacterial species. The detection of exchanged regions is often based upon analysis of compositional characteristics and their comparison to the organism as a whole. In this study we describe a new methodology combining aspects of established signature analysis with textual analysis approaches. This approach has been used to analyze the two available genome sequences of H. pylori. Results This gene-by-gene analysis reveals a wide range of genes related to both virulence behaviour and the strain differences that have been relatively recently acquired from other sequence backgrounds. These frequently involve single genes or small numbers of genes that are not associated with transposases or bacteriophage genes, nor with inverted repeats typically used as markers for horizontal transfer. In addition, clear examples of horizontal exchange in genes associated with 'core' metabolic functions were identified, supported by differences between the sequenced strains, including: ftsK, xerD and polA. In some cases it was possible to determine which strain represented the 'parent' and 'altered' states for insertion-deletion events. Different signature component lengths showed different sensitivities for the detection of some horizontally transferred genes, which may reflect different amelioration rates of sequence components. Conclusion New implementations of signature analysis that can be applied on a gene-by-gene basis for the identification of horizontally acquired sequences are described. These findings highlight the central role of the availability of homologous substrates in evolution mediated by horizontal exchange, and suggest that some components of the supposedly stable 'core genome' may actually be favoured targets for integration of foreign sequences because of their degree of conservation

Intergalactic Photon Spectra from the Far IR to the UV Lyman Limit for 0<z<60 < z < 6 and the Optical Depth of the Universe to High Energy Gamma-Rays

We calculate the intergalactic photon density as a function of both energy and redshift for 0 < z < 6 for photon energies from .003 eV to the Lyman limit cutoff at 13.6 eV in a Lambda-CDM universe with $\Omega_{\Lambda} = 0.7$ and $\Omega_{m} = 0.3$. Our galaxy evolution model gives results which are consistent with Spitzer deep number counts and the spectral energy distribution of the extragalactic background radiation. We use our photon density results to extend previous work on the absorption of high energy gamma-rays in intergalactic space owing to interactions with low energy photons and the 2.7 K cosmic background radiation. We calculate the optical depth of the universe, tau, for gamma-rays having energies from 4 GeV to 100 TeV emitted by sources at redshifts from ~0 to 5. We also give an analytic fit with numerical coefficients for approximating $\tau(E_{\gamma}, z)$. As an example of the application of our results, we calculate the absorbed spectrum of the blazar PKS 2155-304 at z = 0.117 and compare it with the spectrum observed by the H.E.S.S. air Cherenkov gamma-ray telescope array.Comment: final version to be published in Ap

An Empirically Based Calculation of the Extragalactic Infrared Background

Using the excellent observed correlations among various infrared wavebands with 12 and 60 micron luminosities, we calculate the 2-300 micron spectra of galaxies as a function of luminosity. We then use 12 micron and 60 micron galaxy luminosity functions derived from IRAS data, together with recent data on the redshift evolution of galaxy emissivity, to derive a new, empirically based IR background spectrum from stellar and dust emission in galaxies. Our best estimate for the IR background is of order 2-3 nW/m^2/sr with a peak around 200 microns reaching 6-8 nW/m^2/sr. Our empirically derived background spectrum is fairly flat in the mid-IR, as opposed to spectra based on modeling with discrete temperatures which exhibit a "valley" in the mid-IR. We also derive a conservative lower limit to the IR background which is more than a factor of 2 lower than our derived flux.Comment: 14 pages AASTeX, 2 .ps figures, the Astrophysical Journal, in pres

The vulnerability of shrimp farming income to climate change events

Purpose This paper aims to investigate shrimp income losses of farmers in the four farming systems in the research areas of Ca Mau, Vietnam, and determine the vulnerability of shrimp farming income to climate change events. Design/methodology/approach Field research interviews were conducted with 100 randomly selected households across the four farming systems to access shrimp income status and vulnerability levels to climate change events. Four focus groups, each aligned to a particular farming system, were surveyed to categorise likelihood and consequences of climate change effects based on a risk matrix worksheet to derive levels of risk, adaptive capacity and vulnerability levels. Findings Shrimp farmers in the study areas have been facing shrimp income reduction recently and shrimp farming income is vulnerable to climate change events. There are some differences between farmers’ perspectives on vulnerability levels, but some linkages are evident among shrimp farmer characteristics, ramifications for each farming system, shrimp income losses and shrimp farmers’ perspectives on vulnerability levels of shrimp incomes. From an income perspective, farmers operating in intensive shrimp farming systems appear to be less vulnerable to existing and expected climate change effects relative to those in mixed production or lower density systems. Originality/value Having identified the vulnerability level of shrimp farming income to climate change events in different farming systems based on shrimp farmers’ perspectives, the paper adds new knowledge to existing research on vulnerability of the aquaculture sector to climate change. The research findings have implications for policymakers who may choose to encourage intensive shrimp farming to enhance shrimp farmer resilience to the effects of climate change as well as improving cultivation techniques for shrimp farmers. The findings could thus guide local government decision-making on climate change responses and residents of Ca Mau as well as within the wider Mekong Delta in developing suitable practical adaption measures

Derivation of the quantum probability law from minimal non-demolition measurement

One more derivation of the quantum probability rule is presented in order to shed more light on the versatile aspects of this fundamental law. It is shown that the change of state in minimal quantum non-demolition measurement, also known as ideal measurement, implies the probability law in a simple way. Namely, the very requirement of minimal change of state, put in proper mathematical form, gives the well known Lueders formula, which contains the probability rule.Comment: 8 page