What we can learn from magnetic Compton scattering : application to the determination of spin polarization

Studies of spin-resolved electron momentum densities involve the measurement of the so-called magnetic Compton profile. This is a one-dimensional projection of the electron momentum distribution of only those electrons that contribute to the spin moment of a sample. The technique is applicable to ferri- and ferromagnetic materials. The profile is obtained via the inelastic 'Compton' scattering of high energy X-rays. Since electrons originating from different atomic orbitals have specific momentum densities, it is often possible to determine the origin of the magnetism present. Typically, interpretation requires the use of electronic structure calculations using molecular orbital and band structure approaches. Here, we highlight the application of the technique to the determination of the Fermi level spin polarization, the knowledge of which is important to the development of novel spintronic materials

A 'Different Class'? Homophily and Heterophily in the Social Class Networks of Britpop

Social network analysis is increasingly recognised as a useful way to explore music scenes. In this article we examine the individuals who were the cultural workforce that comprised the 'Britpop' music scene of the 1990s. The focus of our analysis is homophily and heterophily to determine whether the clusters of friendships and working relationships of those who were ‘best connected’ in the scene were patterned by original social class position. We find that Britpop's 'whole network' is heterophilic but its 'sub-networks' are more likely to be social class homophilic. The sub-networks that remain heterophilic are likely to be united by other common experiences that brought individuals in the network to the same social spaces. We suggest that our findings on Britpop might be generalised to the composition of other music scenes, cultural workforces and aggregations of young people. Our study differs from research on, first, British ‘indie music’ and social class which focusses upon the construction, representation and performance of social location rather than the relationships it might shape (such as Wiseman-Trowse, 2008) and second, the pioneering social network analyses of music scenes (such as Crossley 2008; 2009; 2015; Crossley et. al 2014) which currently lacks the explicit emphasis on social class

CTLA4 is expressed on mature dendritic cells derived from human monocytes and influences their maturation and antigen presentation

<p>Abstract</p> <p>Background</p> <p>Dendritic cells (DCs) initiate immune responses through their direct interaction with effector cells. However, the mechanism by which DC activity is regulated is not well defined. Previous studies have shown that CTLA4 on T cells regulates DCs function by "cross-talk". We investigated whether there is an intrinsic regulatory mechanism in DCs, with CTLA4 as a candidate regulator.</p> <p>Results</p> <p>We confirmed via RT-PCR and flow cytometry the natural expression of CTLA4 on mature DCs derived from human monocytes. Approximately 8% CD1a-positive cells express CTLA4 both on surface and intracellular, whereas 10% CD1a-negative cells express CTLA4 intracellularly, but little expression was observed on the cell surface. The cross-linking of CTLA4 inhibits DCs maturation and antigen presentation in vitro, but does not inhibit endocytosis.</p> <p>Conclusions</p> <p>CTLA4 is expressed by DCs and plays an inhibitory role. CTLA4-expressing DCs may represent a group of regulatory DCs. Because of its wide distribution on different cell types, CTLA4 may play a general role in regulating immune responses.</p

PRIMO: an interactive homology modeling pipeline

The development of automated servers to predict the three-dimensional structure of proteins has seen much progress over the years. These servers make calculations simpler, but largely exclude users from the process. In this study, we present the PRotein Interactive MOdeling (PRIMO) pipeline for homology modeling of protein monomers. The pipeline eases the multi-step modeling process, and reduces the workload required by the user, while still allowing engagement from the user during every step. Default parameters are given for each step, which can either be modified or supplemented with additional external input. PRIMO has been designed for users of varying levels of experience with homology modeling. The pipeline incorporates a user-friendly interface that makes it easy to alter parameters used during modeling

CD200 Receptor Controls Sex-Specific TLR7 Responses to Viral Infection

Immunological checkpoints, such as the inhibitory CD200 receptor (CD200R), play a dual role in balancing the immune system during microbial infection. On the one hand these inhibitory signals prevent excessive immune mediated pathology but on the other hand they may impair clearance of the pathogen. We studied the influence of the inhibitory CD200-CD200R axis on clearance and pathology in two different virus infection models. We find that lack of CD200R signaling strongly enhances type I interferon (IFN) production and viral clearance and improves the outcome of mouse hepatitis corona virus (MHV) infection, particularly in female mice. MHV clearance is known to be dependent on Toll like receptor 7 (TLR7)-mediated type I IFN production and sex differences in TLR7 responses previously have been reported for humans. We therefore hypothesize that CD200R ligation suppresses TLR7 responses and that release of this inhibition enlarges sex differences in TLR7 signaling. This hypothesis is supported by our findings that in vivo administration of synthetic TLR7 ligand leads to enhanced type I IFN production, particularly in female Cd200−/− mice and that CD200R ligation inhibits TLR7 signaling in vitro. In influenza A virus infection we show that viral clearance is determined by sex but not by CD200R signaling. However, absence of CD200R in influenza A virus infection results in enhanced lung neutrophil influx and pathology in females. Thus, CD200-CD200R and sex are host factors that together determine the outcome of viral infection. Our data predict a sex bias in both beneficial and pathological immune responses to virus infection upon therapeutic targeting of CD200-CD200R

Waiting for other people: a psychoanalytic interpretation of the time for action

Typical responses to a confrontation with failures in authority, or what Lacanians term ‘the lack in the Other’, involve attempts to shore it up. A patient undergoing psychoanalysis eventually faces the impossibility of doing this successfully; the Other will always be lacking. This creates a space through which she can reimagine how she might intervene in her suffering. Similarly, when coronavirus forces us to confront the brute fact of the lack in the Other at the socio-political level, we have the opportunity to discover a space for acting rather than continuing symptomatic behaviour that increasingly fails to work

Towards a spatial critique of ideology: architecture as a test

The article presents the outline for the theory of ideological space. The ideological properties of space are reconsidered by the juxtaposition of Lefebvre’s and Bourdieu’s theories. The resultant reconciliation points towards the notion of spatial critique of ideology as well as the possibility of employing ideology for critique of space. The notion of a test (as characterized by Boltanski) is introduced to show the importance of capabilities of actors and objects in the process of critique. The article emphasizes the exceptional significance of architecture for the construction of critical positions. The architecture is described as a form of a test. In so doing, the architecture is characterized as one of the essential elements of possible social emancipation. In effect, both the social responsibilities of the architecture and its critical role are underscored

CD200 receptor restriction of myeloid cell responses antagonizes antiviral immunity and facilitates cytomegalovirus persistence within mucosal tissue

CD200 receptor (CD200R) negatively regulates peripheral and mucosal innate immune responses. Viruses, including herpesviruses, have acquired functional CD200 orthologs, implying that viral exploitation of this pathway is evolutionary advantageous. However, the role that CD200R signaling plays during herpesvirus infection in vivo requires clarification. Utilizing the murine cytomegalovirus (MCMV) model, we demonstrate that CD200R facilitates virus persistence within mucosal tissue. Specifically, MCMV infection of CD200R-deficient mice (CD200R-/-) elicited heightened mucosal virus-specific CD4 T cell responses that restricted virus persistence in the salivary glands. CD200R did not directly inhibit lymphocyte effector function. Instead, CD200R-/- mice exhibited enhanced APC accumulation that in the mucosa was a consequence of elevated cellular proliferation. Although MCMV does not encode an obvious CD200 homolog, productive replication in macrophages induced expression of cellular CD200. CD200 from hematopoietic and non-hematopoietic cells contributed independently to suppression of antiviral control in vivo. These results highlight the CD200-CD200R pathway as an important regulator of antiviral immunity during cytomegalovirus infection that is exploited by MCMV to establish chronicity within mucosal tissue