405 research outputs found
2-Vector Spaces and Groupoids
This paper describes a relationship between essentially finite groupoids and
2-vector spaces. In particular, we show to construct 2-vector spaces of
Vect-valued presheaves on such groupoids. We define 2-linear maps corresponding
to functors between groupoids in both a covariant and contravariant way, which
are ambidextrous adjoints. This is used to construct a representation--a weak
functor--from Span(Gpd) (the bicategory of groupoids and spans of groupoids)
into 2Vect. In this paper we prove this and give the construction in detail.Comment: 44 pages, 5 figures - v2 adds new theorem, significant changes to
proofs, new sectio
Diversity of gut microflora is required for the generation of B cell with regulatory properties in a skin graft model
B cells have been reported to promote graft rejection through alloantibody production. However, there is growing evidence that B cells can contribute to the maintenance of tolerance. Here, we used a mouse model of MHC-class I mismatched skin transplantation to investigate the contribution of B cells to graft survival. We demonstrate that adoptive transfer of B cells prolongs skin graft survival but only when the B cells were isolated from mice housed in low sterility "conventional" (CV) facilities and not from mice housed in pathogen free facilities (SPF). However, prolongation of skin graft survival was lost when B cells were isolated from IL-10 deficient mice housed in CV facilities. The suppressive function of B cells isolated from mice housed in CV facilities correlated with an anti-inflammatory environment and with the presence of a different gut microflora compared to mice maintained in SPF facilities. Treatment of mice in the CV facility with antibiotics abrogated the regulatory capacity of B cells. Finally, we identified transitional B cells isolated from CV facilities as possessing the regulatory function. These findings demonstrate that B cells, and in particular transitional B cells, can promote prolongation of graft survival, a function dependent on licensing by gut microflora
AQFT from n-functorial QFT
There are essentially two different approaches to the axiomatization of
quantum field theory (QFT): algebraic QFT, going back to Haag and Kastler, and
functorial QFT, going back to Atiyah and Segal. More recently, based on ideas
by Baez and Dolan, the latter is being refined to "extended" functorial QFT by
Freed, Hopkins, Lurie and others. The first approach uses local nets of
operator algebras which assign to each patch an algebra "of observables", the
latter uses n-functors which assign to each patch a "propagator of states".
In this note we present an observation about how these two axiom systems are
naturally related: we demonstrate under mild assumptions that every
2-dimensional extended Minkowskian QFT 2-functor ("parallel surface transport")
naturally yields a local net. This is obtained by postcomposing the propagation
2-functor with an operation that mimics the passage from the Schroedinger
picture to the Heisenberg picture in quantum mechanics.
The argument has a straightforward generalization to general
pseudo-Riemannian structure and higher dimensions.Comment: 39 pages; further examples added: Hopf spin chains and asymptotic
inclusion of subfactors; references adde
APEX at the QSO MUSEUM: molecular gas reservoirs associated with z 3 quasars and their link to the extended Ly alpha emission
Interstellar matter and star formatio
Lymphocyte and monocyte flow cytometry immunophenotyping as a diagnostic tool in uncharacteristic inflammatory disorders
<p>Abstract</p> <p>Background</p> <p>Patients with uncharacteristic inflammatory symptoms such as long-standing fatigue or pain, or a prolonged fever, constitute a diagnostic and therapeutic challenge. The aim of the present study was to determine if an extended immunophenotyping of lymphocytes and monocytes including activation markers can define disease-specific patterns, and thus provide valuable diagnostic information for these patients.</p> <p>Methods</p> <p>Whole blood from patients with gram-negative bacteraemia, neuroborreliosis, tuberculosis, acute mononucleosis, influenza or a mixed connective tissue disorders, as diagnosed by routine culture and serology techniques was analysed for lymphocyte and monocyte cell surface markers using a no-wash, no-lyse protocol for multi-colour flow cytometry method. The immunophenotyping included the activation markers HLA-DR and CD40. Plasma levels of soluble TNF alpha receptors were analysed by ELISA.</p> <p>Results</p> <p>An informative pattern was obtained by combining two of the analysed parameters: (i), the fractions of HLA-DR-expressing CD4+ T cells and CD8+ T cells, respectively, and (ii), the level of CD40 on CD14+ CD16- monocytes. Patients infected with gram-negative bacteria or EBV showed a marked increase in monocyte CD40, while this effect was less pronounced for tuberculosis, borrelia and influenza. The bacterial agents could be distinguished from the viral agents by the T cell result; CD4+ T cells reacting in bacterial infection, and the CD8+ T cells dominating for the viruses. Patients with mixed connective tissue disorders also showed increased activation, but with similar engagement of CD4+ and CD8+ T cells. Analysis of soluble TNF alpha receptors was less informative due to a large inter-individual variation.</p> <p>Conclusion</p> <p>Immunophenotyping including the combination of the fractions of HLA-DR expressing T cell subpopulations with the level of CD40 on monocytes produces an informative pattern, differentiating between infections of bacterial and viral origin. Furthermore, a quantitative analysis of these parameters revealed the novel finding of characteristic patterns indicating a subacute bacterial infection, such as borreliosis or tuberculosis, or a mixed connective tissue disorder. The employed flow cytometric method is suitable for clinical diagnostic laboratories, and may help in the assessment of patients with uncharacteristic inflammatory symptoms.</p
Association of CD40 Gene Polymorphisms with Sporadic Breast Cancer in Chinese Han Women of Northeast China
BACKGROUND: Breast cancer is a polygenetic disorder with a complex inheritance pattern. Single nucleotide polymorphisms (SNPs), the most common genetic variations, influence not only phenotypic traits, but also interindividual predisposition to disease, treatment outcomes with drugs and disease prognosis. The co-stimulatory molecule CD40 plays a prominent role in immune regulation and homeostasis. Accumulating evidence suggests that CD40 contributes to the pathogenesis of cancer. Here, we set out to test the association between polymorphisms in the CD40 gene and breast carcinogenesis and tumor pathology. METHODOLOGY AND PRINCIPAL FINDINGS: Four SNPs (rs1800686, rs1883832, rs4810485 and rs3765459) were genotyped by the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method in a case-control study including 591 breast cancer patients and 600 age-matched healthy controls. Differences in the genotypic distribution between breast cancer patients and healthy controls were analyzed by the Chi-square test for trends. Our preliminary data showed a statistically significant association between the four CD40 gene SNPs and sporadic breast cancer risk (additive P = 0.0223, 0.0012, 0.0013 and 0.0279, respectively). A strong association was also found using the dominant, recessive and homozygote comparison genetic models. In the clinical features analysis, significant associations were observed between CD40 SNPs and lymph node metastasis, human epidermal growth factor receptor 2 (C-erbB2), estrogen receptor (ER), progesterone receptor (PR) and tumor protein 53 (P53) statuses. In addition, our haplotype analysis indicated that the haplotype C(rs1883832)G(rs4810485), which was located within the only linkage disequilibrium (LD) block identified, was a protective haplotype for breast cancer, whereas T(rs1883832)T(rs4810485) increased the risk in the studied population, even after correcting the P value for multiple testing (P = 0.0337 and 0.0430, respectively). CONCLUSIONS AND SIGNIFICANCE: Our findings primarily show that CD40 gene polymorphisms contribute to sporadic breast cancer risk and have a significant association with clinicopathological features among Chinese Han women from the Heilongjiang Province
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