4,881 research outputs found

    Social Relationships of International Students Attending Oklahoma State University

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    Student Personnel and Guidanc

    The connective Morava K-theory of the second mod p Eilenberg-MacLane space

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    We develop tools for computing the connective n-th Morava K-theory of spaces. Starting with a Universal Coefficient Theorem that computes the cohomology version from the homology version, we show that every step in the process of computing one is mirrored in the other and that this can be used to make computations. As our example, we compute the connective n-th Morava K-theory of the second mod p Eilenberg-MacLane space.Comment: minor change of title and one sentence adde

    Space-Time Foam From Non-Commutative Instantons

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    We show that a U(1) instanton on non-commutative R^4 corresponds to a supersymmetric non-singular U(1) gauge field on a commutative Kahler manifold X which is a blowup of C^2 at a finite number of points. For instanton charge k the manifold X can be viewed as a space-time foam. A direct connection with integrable systems of Calogero-Moser type is established. We also make some comments on the non-abelian case.Comment: harvmac, 22 pp; v.2, refs added, a section adde

    The Nuclear Ionized Gas in the Radio Galaxy M84 (NGC 4374)

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    We present optical images of the nucleus of the nearby radio galaxy M84 (NGC 4374 = 3C272.1) obtained with the Wide Field/Planetary Camera 2 (WFPC2) aboard the Hubble Space Telescope (HST). Our three images cover the Hα\alpha + [N II] emission lines as well as the V and I continuum bands. Analysis of these images confirms that the Hα\alpha + [N II] emission in the central 5'' (410 pc) is elongated along position angle (P.A.) \approx 72\arcdeg, which is roughly parallel to two nuclear dust lanes.Our high-resolution images reveal that the Hα\alpha + [N II] emission has three components, namely a nuclear gas disk,an `ionization cone', and outer filaments. The nuclear disk of ionized gas has diameter 1=82\approx 1'' = 82 pc and major axis P.A. \approx 58\arcdeg \pm 6\arcdeg. On an angular scale of 0\farcs5, the major axis of this nuclear gas disk is consistent with that of the dust. However, the minor axis of the gas disk (P.A. \approx 148\arcdeg) is tilted with respect to that of the filamentary Hα\alpha + [N II] emission at distances > 2'' from the nucleus; the minor axis of this larger scale gas is roughly aligned with the axis of the kpc-scale radio jets (P.A. \approx 170\arcdeg). The ionization cone (whose apex is offset by \approx 0\farcs3 south of the nucleus) extends 2'' from the nucleus along the axis of the southern radio jet. This feature is similar to the ionization cones seen in some Seyfert nuclei, which are also aligned with the radio axes.Comment: 11 pages plus 4 figure

    Material identification of soft tissue using membrane inflation

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    The constitutive equation for large elastic deformations is often used to model the mechanical response of soft tissue. This paper is concerned with the applications of the method of material identification to the determination of the strain energy density functions (W) in such a mode, under the assumption that the tissue is incompressible and isotropic. It is shown that an identification experiment based on inflation by lateral pressure of an initially flat circular membraneous specimen has a number of advantages. These are: the method of clamping the specimen, the ease of labelling material particles and measuring current coordinates, the easily determined domain of identification of W, and a means of systematically determining W over a large deformation range. An example in the form of a hypothetical experiment is presented.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23752/1/0000725.pd

    Matrix metalloproteinase-7 facilitates immune access to the CNS in experimental autoimmune encephalomyelitis

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    <p>Abstract</p> <p>Background</p> <p>Metalloproteinase inhibitors can protect mice against experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis (MS). Matrix metalloproteinase-9 (MMP-9) has been implicated, but it is not clear if other MMPs are also involved, including matrilysin/MMP-7 – an enzyme capable of cleaving proteins that are essential for blood brain barrier integrity and immune suppression.</p> <p>Results</p> <p>Here we report that MMP-7-deficient (<it>mmp7</it><sup>-/-</sup>) mice on the C57Bl/6 background are resistant to EAE induced by myelin oligodendrocyte glycoprotein (MOG). Brain sections from MOG-primed <it>mmp7</it><sup>-/-</sup>mice did not show signs of immune cell infiltration of the CNS, but MOG-primed wild-type mice showed extensive vascular cuffing and mononuclear cell infiltration 15 days after vaccination. At the peak of EAE wild-type mice had MMP-7 immuno-reactive cells in vascular cuffs that also expressed the macrophage markers Iba-1 and Gr-1, as well as tomato lectin. MOG-specific proliferation of splenocytes, lymphocytes, CD4<sup>+ </sup>and CD8<sup>+ </sup>cells were reduced in cells isolated from MOG-primed <it>mmp7</it><sup>-/- </sup>mice, compared with MOG-primed wild-type mice. However, the adoptive transfer of splenocytes and lymphocytes from MOG-primed <it>mmp7</it><sup>-/- </sup>mice induced EAE in naïve wild-type recipients, but not naïve <it>mmp7</it><sup>-/- </sup>recipients. Finally, we found that recombinant MMP-7 increased permeability between endothelial cells in an <it>in vitro </it>blood-brain barrier model.</p> <p>Conclusion</p> <p>Our findings suggest that MMP-7 may facilitate immune cell access or re-stimulation in perivascular areas, which are critical events in EAE and multiple sclerosis, and provide a new therapeutic target to treat this disorder.</p

    Scaling algebras and pointlike fields: A nonperturbative approach to renormalization

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    We present a method of short-distance analysis in quantum field theory that does not require choosing a renormalization prescription a priori. We set out from a local net of algebras with associated pointlike quantum fields. The net has a naturally defined scaling limit in the sense of Buchholz and Verch; we investigate the effect of this limit on the pointlike fields. Both for the fields and their operator product expansions, a well-defined limit procedure can be established. This can always be interpreted in the usual sense of multiplicative renormalization, where the renormalization factors are determined by our analysis. We also consider the limits of symmetry actions. In particular, for suitable limit states, the group of scaling transformations induces a dilation symmetry in the limit theory.Comment: minor changes and clarifications; as to appear in Commun. Math. Phys.; 37 page

    Brown–Peterson Cohomology from Morava K-Theory

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    Broad-Range Bacterial Detection and the Analysis of Unexplained Death and Critical Illness

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    Broad-range rDNA polymerase chain reaction (PCR) provides an alternative, cultivation-independent approach for identifying pathogens. In 1995, the Centers for Disease Control and Prevention initiated population-based surveillance for unexplained life-threatening infections (Unexplained Death and Critical Illness Project [UNEX]). To address the causes of UNEX cases, we examined 59 specimens from 46 cases by using broad-range bacterial 16S rDNA PCR and phylogenetic analysis of amplified sequences. Specimens from eight cases yielded sequences from Neisseria meningitidis (cerebrospinal fluid from two patients with meningitis), Streptococcus pneumoniae (cerebrospinal fluid from one patient with meningitis and pleural fluid from two patients with pneumonia), or Stenotrophomonas maltophilia (bone marrow aspirate from one patient with pneumonia). Streptococcus pneumoniae rDNA sequence microheterogeneity was found in one pleural fluid specimen, suggesting the presence of multiple strains. In conclusion, known bacterial pathogens cause some critical illnesses and deaths that fail to be explained with traditional diagnostic methods
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