Modeling flows in periodically heterogeneous porous media with deformation-dependent permeability

The paper proposes a non-linear model of the Biot continuum. The nonlienarity is introduced in terms of the material coefficients which are expressed as linear functions of the macroscopic response. These functions are obtained by the sensitivity analysis of the homogenized coefficients computed for a given geometry of the porous structure which transforms due to the local deformation. Linear kinematics is assumed, however, the approach can be extended to large deforming porous materials

Dynamics and constraints of the Unified Dark Matter flat cosmologies

We study the dynamics of the scalar field FLRW flat cosmological models within the framework of the Unified Dark Matter (UDM) scenario. In this model we find that the main cosmological functions such as the scale factor of the Universe, the scalar field, the Hubble flow and the equation of state parameter are defined in terms of hyperbolic functions. These analytical solutions can accommodate an accelerated expansion, equivalent to either the dark energy or the standard $\Lambda$ models. Performing a joint likelihood analysis of the recent supernovae type Ia data and the Baryonic Acoustic Oscillations traced by the SDSS galaxies, we place tight constraints on the main cosmological parameters of the UDM cosmological scenario. Finally, we compare the UDM scenario with various dark energy models namely $\Lambda$ cosmology, parametric dark energy model and variable Chaplygin gas. We find that the UDM scalar field model provides a large and small scale dynamics which are in fair agreement with the predictions by the above dark energy models although there are some differences especially at high redshifts.Comment: 11 pages, 7 figures, published in Physical Review D, 78, 083509, (2008

The equality implications of being a migrant in Britain.

Researching the equality implications of being a migrant in Britain is hampered by imprecise definitions of what a migrant is and by a lack of data on many equality groups (groups which share a common attribute in respect of age, disability, gender, race, religion or belief, or sexual orientation, as defined by the Equality Act 2006). The literature and evidence on inequalities tends to be more abundant on gender and race but remains focused on ethnic minority categories rather than on migrants as such. While the foreign-born population in the UK has increased from four to six million over the last decade, people arrive via different routes and with varying intentions. Much recent debate on the benefits and pressures resulting from immigration has been provoked by the large numbers of arrivals from Eastern Europe since 2004, but they, like other migrants from the European Union (EU), have freedom of movement guaranteed by EU Directives. Although they have to register or obtain authorisation to work legally (and 766,000 had registered by the end of 2007), there are few reliable statistics on their presence in specific areas or in the UK as a whole. Other migrants from outside the EU also come to the UK to work (about 200,000 in 2006) or study (309,000 in 2006). A number of migrants, estimated at between 310,000 and 570,000, are believed to be living in the country without formal immigration authorisation. In 2007, the largest group of those born abroad was from India (553,300), followed by those from Poland (423,300). There are significant differences in terms of gender and age between different national groups, comprising recent and established migrants, and in their experiences of employment and access to services. This heterogeneity makes policymaking based on averages or an assumed homogeneity meaningless or even dangerous

New migrants in England and their needs.

This research was commissioned in 2007 and maps new migrant communities in the UK. It includes a report, anecdotal information from stakeholder interviews and 11 locality studies which summarises and explain all available data sets

A Narnavirus in the trypanosomatid protist plant pathogen Phytomonas serpens

We describe here a new RNA virus (PserNV1) from the plant protist parasite Phytomonas serpens (family Trypanosomatidae, Kinetoplastida, supergroup Excavata). The properties of PserNV1 permit assignment to the genus Narnavirus (Narnaviridae), the first reported from a host other than fungi or oomycetes

A novel bunyavirus-like virus of trypanosomatid protist parasites

We report here the sequences for all three segments of a novel RNA virus (LepmorLBV1) from the insect trypanosomatid parasite Leptomonas moramango. This virus belongs to a newly discovered group of bunyavirus-like elements termed Leishbunyaviruses (LBV), the first discovered from protists related to arboviruses infecting humans

'An Apotheosis of Well-Being': Durkheim on austerity and double-dip recessions

This article is an attempt to contribute a view on the economic crisis from classical sociology, a voice often missing from the sociological response to the crisis. The work of Émile Durkheim provides a unique perspective here centred on morality and inequality produced in a historical context akin to our neoliberal times. It is argued there are four key points to take from Durkheim’s work. Firstly, that the initial credit crunch can be more fully understood with reference to the economic anomie which Durkheim sees as ‘chronic’ in a time of marketization. Secondly, that this creates an antagonistic relationship between a supposedly self-dependent rich and lazy poor. Thirdly, this conception of self-dependency and individual initiative makes any attempt to regulate the economy akin to sacrilege. Finally, the state is unwilling to intervene due to the emergence of ‘pseudo-democracies’. Therefore, Durkheim’s theory accounts for the initial crisis, austerity and double-dip recessions in a sociological framework. The article concludes by returning to the centrality of morality to the crisis for Durkheim and highlighting the omission of this in contemporary debates

A Symmetric Integrator for non-integrable Hamiltonian Relativistic Systems

By combining a standard symmetric, symplectic integrator with a new step size controller, we provide an integration scheme that is symmetric, reversible and conserves the values of the constants of motion. This new scheme is appropriate for long term numerical integrations of geodesic orbits in spacetime backgrounds, whose corresponding Hamiltonian system is non-integrable, and, in general, for any non-integrable Hamiltonian system whose kinetic part depends on the position variables. We show by numerical examples that the new integrator is faster and more accurate i) than the standard symplectic integration schemes with or without standard adaptive step size controllers and ii) than an adaptive step Runge-Kutta scheme.Comment: 12 pages, 8 figures, 3 table

Expression of Epstein–Barr Virus–Encoded Small RNA (by the EBER-1 Gene) in Liver Specimens from Transplant Recipients with Post-Transplantation Lymphoproliferative Disease

Epstein-Barr virus (EBV)—associated post-transplantation lymphoproliferative disease (PTLD) develops in 1 to 10 percent of transplant recipients, in whom it can be treated by a reduction in the level of immunosuppression. We postulated that the tissue expression of the small RNA transcribed by the EBER-1 gene during latent EBV infection would identify patients at risk for PTLD. We studied EBER-1 gene expression in liver specimens obtained from 24 patients 2 days to 22 months before the development of PTLD, using in situ hybridization with an oligonucleotide probe. Control specimens were obtained from 20 recipients of allografts with signs of injury due to organ retrieval, acute graft rejection, or viral hepatitis in whom PTLD had not developed 9 to 71 months after the biopsy. Of the 24 patients with PTLD, 17 (71 percent) had specimens in which 1 to 40 percent of mononuclear cells were positive for the EBER-1 gene. In addition, 10 of these 17 patients (59 percent) had specimens with histopathological changes suggestive of EBV hepatitis. In every case, EBER-1—positive cells were found within the lymphoproliferative lesions identified at autopsy. Only 2 of the 20 controls (10 percent) had specimens with EBER-1—positive cells (P<0.001), and such cells were rare. EBER-1 gene expression in liver tissue precedes the occurrence of clinical and histologic PTLD. The possibility of identifying patients at risk by the method we describe here and preventing the occurrence of PTLD by a timely reduction of immunosuppression needs to be addressed by future prospective studies. (N Engl J Med 1992;327:1710–4.), POST-TRANSPLANTATION lymphoproliferative disease (PTLD), either polyclonal or monoclonal, complicates the clinical course of 1 to 10 percent of organ-transplant recipients.123 Immunohistochemical studies have demonstrated that the lymphoid cells within the lesions of PTLD almost invariably contain Epstein–Barr virus (EBV), primarily in a state of latent infection.4,5 The EBER-1 gene is expressed early during latent EBV infection and codes for a small messenger RNA (mRNA) expressed at up to 107 copies per cell.6 We and others have previously demonstrated the value of the detection of EBER-1 RNA for identifying EBV-infected cells in formalin-fixed paraffin-embedded tissues.7,8 In the current investigation, we used… © 1992, Massachusetts Medical Society. All rights reserved