125 research outputs found

    Boundaries and Defects of N=4 SYM with 4 Supercharges, Part II: Brane Constructions and 3d N=2 Field Theories

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    We study the vacuum moduli spaces of 3d N=2 supersymmetric quantum field theories by applying the formalism developed in our previous paper arXiv:1404.5527. The 3d theories can be realized by branes in type IIB string theory, which in a decoupling limit reduce to 4d N=4 super-Yang-Mills theory on an interval with BPS defects inserted. The moduli space of a given 3d theory is obtained by solving a generalization of Nahm's equations with appropriate boundary/junction conditions, along with help from the S-duality of type IIB string theory. Our classical computations reproduce many known results about the quantum-corrected moduli spaces of 3d theories, e.g. U(N_c) theories with N_f flavors with mass and FI parameters turned on. In particular, our methods give first-principles derivations of several results in the literature, including the s-rule, quantum splitting of classical Coulomb branches, the lifting of the Coulomb branch by non-Abelian instantons, quantum merging of Coulomb and Higgs branches, and phase transitions from re-ordering 5-branes.Comment: 83 pages, 27 figure

    Boundaries and Defects of N=4 SYM with 4 Supercharges, Part I: Boundary/Junction Conditions

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    We consider N=4{\cal N}=4 supersymmetric Yang Mills theory on a space with supersymmetry preserving boundary conditions. The boundaries preserving half of the 16 supercharges were analyzed and classified in an earlier work by Gaiotto and Witten. We extend that analysis to the case with fewer supersymmetries, concentrating mainly on the case preserving one quarter. We develop tools necessary to explicitly construct boundary conditions which can be viewed as taking the zero slope limit of a system of D3 branes intersecting and ending on a collection of NS5 and D5 branes oriented to preserve the appropriate number of supersymmetries. We analyze how these boundary conditions constrain the bulk degrees of freedom and enumerate the unconstrained degrees of freedom from the boundary/defect field theory point of view. The key ingredients used in the analysis are a generalized version of Nahm's equations and the explicit boundary/interface conditions for the NS5-like and D5-like impurities and boundaries, which we construct and describe in detail. Some bulk degrees of freedom suggested by the naive brane diagram considerations are lifted.Comment: 75 pages, 21 figure

    Rapid diagnosis of lyme disease: Flagellin gene-based nested polymerase chain reaction for identification of causative Borrelia species

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    AbstractObjective: Each of Borrelia burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii has characteristic restriction sites in its flagellin gene. The authors focused on this gene and developed a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis for rapid diagnosis of Lyme disease.Methods: External and internal primer sets were designed for nested PCR to amplify an approximately 580 by fragment of the flagellin gene that includes species-specific restriction sites. DNA extracted from tissue samples of mice and humans were used as templates for PCR. The amplicons obtained were digested with HapII, HhaI, CelII HincII, or Ddel endonuclease.Results: In mice experimentally infected with each of B. burgdorferi sensu stricto, B. garinii, and B. afzelii, borrelial DNA was detected irrespective of differences in the causative species. However, RFLP of the amplicons was able to identify the species. Skin biopsy samples from 11 Japanese patients with erythema migrans were subjected to both PCR and culture tests. Borrelial infections were detected in seven cases (64%) by PCR and eight cases (73%) by culture. All PCR-positive samples were also positive by culture. The causative species in human infections was easily identified as B. garinii by RFLP analysis of the amplicons.Conclusion: The nested PCR-RFLP system appears to be an easy and reliable diagnostic tool for the detection and species identification of borreliae in human cutaneous biopsies

    Evaluation of the GABAergic nervous system in autistic brain : 123I-iomazenil SPECT study

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    Purpose: To evaluate the GABAA receptor in the autistic brain, we performed 123I-IMZ SPECT in patients with ASD. We compared 123I-IMZ SPECT abnormalities in patients who showed intellectual disturbance or focal epileptic discharge on EEG to those in patients without such findings. Subjects and methods: The subjects consisted of 24 patients with ASD (mean age, 7.3±3.5years), including 9 with autistic disorder (mean age, 7.0±3.7years) and 15 with Asperger’s disorder (mean age, 7.5±3.2years). We used 10 non-symptomatic partial epilepsy patients (mean age, 7.8±3.6years) without intellectual delay as a control group. For an objective evaluation of the 123I-IMZ SPECT results, we performed an SEE (Stereotactic Extraction Estimation) analysis to describe the decrease in accumulation in each brain lobule numerically. Results In the comparison of the ASD group and the control group, there was a dramatic decrease in the accumulation of 123I-IMZ in the superior and medial frontal cortex. In the group with intellectual impairment and focal epileptic discharge on EEG, the decrease in accumulation in the superior and medial frontal cortex was greater than that in the group without these findings. Conclusion The present results suggest that disturbance of the GABAergic nervous system may contribute to the pathophysiology and aggravation of ASD, since the accumulation of 123I-IMZ was decreased in the superior and medial frontal cortex, which is considered to be associated with inference of the thoughts, feelings, and intentions of others (Theory of Mind)

    The Peptide Sequence of Diacyl Lipopeptides Determines Dendritic Cell TLR2-Mediated NK Activation

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    Natural killer (NK) cells are lymphocyte effectors that are activated to control certain microbial infections and tumors. Many NK-activating and regulating receptors are involved in regulating NK cell function. In addition, activation of naïve NK cells is fundamentally triggered by cytokines or myeloid dendritic cells (mDC) in various modes. In this study, we synthesized 16 S-[2,3-bis(palmitoyl)propyl]cysteine (Pam2Cys) lipopeptides with sequences designed from lipoproteins of Staphylococcus aureus, and assessed their functional properties using mouse (C57BL/6) bone marrow-derived DC (BMDC) and NK cells. NK cell activation was evaluated by three criteria: IFN-γ production, up-regulation of NK activation markers and cytokines, and NK target (B16D8 cell) cytotoxicity. The diacylated lipopeptides acted as TLR2 ligands, inducing up-regulation of CD25/CD69/CD86, IL-6, and IL-12p40, which represent maturation of BMDC. Strikingly, the Pam2Cys lipopeptides induced mouse NK cell activation based on these criteria. Cell-cell contact by Pam2Cys peptide-stimulated BMDC and NK cells rather than soluble mediators released by stimulated BMDC induced activation of NK cells. For most lipopeptides, the BMDC TLR2/MyD88 pathway was responsible for driving NK activation, while some slightly induced direct activation of NK cells via the TLR2/MyD88 pathway in NK cells. The potential for NK activation was critically regulated by the peptide primary sequence. Hydrophobic or proline-containing sequences proximal to the N-terminal lipid moiety interfered with the ability of lipopeptides to induce BMDC-mediated NK activation. This mode of NK activation is distinctly different from that induced by polyI:C, which is closely associated with type I IFN-inducing pathways of BMDC. These results imply that the MyD88 pathway of BMDC governs an alternative NK-activating pathway in which the peptide sequence of TLR2-agonistic lipopeptides critically affects the potential for NK activation

    Function of the frontal lobe in autistic individuals: a proton magnetic resonance spectroscopic study

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    Purpose. In this investigation, we studied differences in chemical metabolites in certain brain regions between autistic patients and normal control subjects. Methods. Proton magnetic resonance spectroscopy (1H-MRS) was used to evaluate functional activity in these regions. Specific regions studied were right and left dorsolateral prefrontal cortex(DLPFC) and the anterior cingulated cortex(ACC). Results. In the ACC, the N-acetylaspartate(NAA)/creatine/phosphocreatine(Cr) ratio in autistic patients (n=31) was significantly lower than that in control subjects (n=28). The decrease in the NAA/Cr ratio for the ACC was much greater in the group with worst social ability. NAA/Cr for the left DLPFC and social ability of autistic patients also correlated well. Furthermore, NAA/Cr for the left DLPFC in the group with intelligence quotient (IQ) below 50 was significantly less than in controls. NAA/Cr for the right DLPFC in autistic patients was not decreased compared to controls, and did not correlate with IQ or social ability. Conclusions. These findings suggest neuronal dysfunction in the ACC and left DLPFC in autism, and also a relationship between social disability and metabolic dysfunction in these regions. Dysfunction in the ACC and the left DLPFC may contribute to the pathogenesis of autism

    Findings of brain 99mTc-ECD SPECT in high-functioning autism : 3-dimensional stereotactic ROI template analysis of brain SPECT

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    The aim of this study is confirmation of an abnormal regional cerebral blood flow (rCBF) pattern in high-functioning autism (HFA). Confirmation of an abnormal rCBF pattern in HFA may be useful for elucidate of its pathophysiology and a differential diagnosis, such as with attention-deficit / hyper activity disorder (AD/HD).Brain 99mTc-ECDSPECTwas performed in 16 cases of HFA. The HFA group consisted of 16 cases of HFA. They were all male, with an IQ of 76~126. They had normal brain MRI findings, and had an age of 9~14 years. We examined abnormal rCBF in HFA by comparing the results to those in the control group. The control group consisted of 1male and 4 females cryptogenic epilepsy patients with normal intelligence. They have no problems in learning at school or mental or behavioral traits. They had normal brain MRI or SPECT findings, and had an age of 7~15 years. 3-dimensional stereotactic ROI template (3DSRT) was used to analyze SPECT data. We calculated the ‘relative rCBF (%)’ (RI count of each segment ×100 / Sum of RI count of the corresponding hemisphere), and compared the values between the two groups. We found a significantly low ‘relative rCBF (%)’ in the left temporal region in the HFA group. We also calculated the ‘L/R ratio’ (the ‘relative rCBF(%)’ of a segment on the left side / the ‘relative rCBF (%)’ of the corresponding segment on the right side), and compared the value for each segment between the two groups. There were no significant differences in any segments between the two groups. We also checked for differences in the ‘relative rCBF (%)’ between segments on the right side and corresponding segments on the left side in both the HFA and control groups. We found significant rightltleft perfusion in the angular region and significant leftltright perfusion in the pericallosal, thalamus, and hippocampus region in the HFA group. We also found significant rightltleft perfusion in the temporal region in the control group. Significant hypoperfusion in the left temporal region due to an unidentified underlying brain pathology and abnormal laterality in the angular, temporal (lack of rightltleft perfusion), pericallosal, thalamus, and hippocampus regions may influence the symptoms of autism

    Decreased serum pyridoxal levels in schizophrenia : meta-analysis and Mendelian randomization analysis

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    Background: Alterations in one-carbon metabolism have been associated with schizophrenia, and vitamin B6 is one of the key components in this pathway. Methods: We first conducted a case–control study of serum pyridoxal levels and schizophrenia in a large Japanese cohort (n = 1276). Subsequently, we conducted a meta-analysis of association studies (n = 2125). Second, we investigated whether rs4654748, which was identified in a genome-wide association study as a vitamin B6-related single nucleotide polymorphism, was genetically implicated in patients with schizophrenia in the Japanese population (n = 10 689). Finally, we assessed the effect of serum pyridoxal levels on schizophrenia risk using a Mendelian randomization (MR) approach. Results: Serum pyridoxal levels were significantly lower in patients with schizophrenia than in controls, not only in our cohort, but also in the pooled data set of the meta-analysis of association studies (standardized mean difference –0.48, 95% confidence interval [CI] –0.57 to –0.39, p = 9.8 × 10–24). We failed to find a significant association between rs4654748 and schizophrenia. Furthermore, an MR analysis failed to find a causal relationship between pyridoxal levels and schizophrenia risk (odds ratio 0.99, 95% CI 0.65–1.51, p = 0.96). Limitations: Food consumption and medications may have affected serum pyridoxal levels in our cross-sectional study. Sample size, number of instrumental variables and substantial heterogeneity among patients with schizophrenia are limitations of an MR analysis. Conclusion: We found decreased serum pyridoxal levels in patients with schizophrenia in this observational study. However, we failed to obtain data supporting a causal relationship between pyridoxal levels and schizophrenia risk using the MR approach

    Magnetic Conjugacy of Pc1 Waves and Isolated Proton Precipitation at Subauroral Latitudes: Importance of Ionosphere as Intensity Modulation Region

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    Pc1 geomagnetic pulsations, equivalent to electromagnetic ion cyclotron waves in the magnetosphere, display a specific amplitude modulation, though the region of the modulation remains an open issue. To classify whether the amplitude modulation has a magnetospheric or ionospheric origin, an isolated proton aurora (IPA), which is a proxy of Pc1 wave-particle interactions, is compared with the associated Pc1 waves for a geomagnetic conjugate pair, Halley Research Base in Antarctica and Nain in Canada. The temporal variation of an IPA shows a higher correlation coefficient (0.88) with Pc1 waves in the same hemisphere than that in the opposite hemisphere. This conjugate observation reveals that the classic cyclotron resonance is insufficient to determine the amplitude modulation. We suggest that direct wave radiation from the ionospheric current by IPA should also contribute to the amplitude modulation

    Neuroimaging in autism spectrum disorders : 1H-MRS and NIRS study

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    Using proton magnetic resonance spectroscopy (1H-MRS), we measured chemical metabolites in the left amygdala and the bilateral orbito-frontal cortex (OFC) in children with autism spectrum disorders (ASD). The concentrations of N-acetylaspartate (NAA) in these regions of ASD were significantly decreased compared to those in the control group. In the autistic patients, the NAA concentrations in these regions correlated with their social quotient. These findings suggest the presence of neuronal dysfunction in the amygdala and OFC in ASD. Dysfunction in the amygdala and OFCmay contribute to the pathogenesis of ASD.We performed a near-infrared spectroscopy (NIRS) study to evaluate the mirror neuron system in children with ASD. The concentrations of oxygenated hemoglobin (oxy-Hb) were measured with frontal probes using a 34-channel NIRS machine while the subjects imitated emotional facial expressions. The increments in the concentration of oxy-Hb in the pars opercularis of the inferior frontal gyrus in autistic subjects were significantly lower than those in the controls. However, the concentrations of oxy-Hb in this area were significantly elevated in autistic subjects after they were trained to imitate emotional facial expressions. The results suggest that mirror neurons could be activated by repeated imitation in children with ASD
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