45 research outputs found
String Junctions and the BPS Spectrum of N=2 SU(2) Theory with Massive Matters
We study the BPS spectrum of four dimensional N=2 SU(2) theory with massive
fundamental matters using the D3-brane probe. Since the BPS states are realized
by string webs subject to the BPS conditions, we determine explicitly the
configurations of such webs. It is observed that there appear BPS string webs
with multiple of junctions corresponding to the fact that the curves of
marginal stability in massive theory are infinitely nested. In terms of the
string configurations, various properties of the curves of marginal stability
are explained intuitively.Comment: 16 pages, LaTex, 5 figure
Coupling Constant Dependence of the Kaluza--Klein Spectrum in Five-Dimensional SQCD on S^1
We investigate the Kaluza--Klein (KK) spectrum of N=1 supersymmetric gauge
theory compactified on a circle. We concentrate on a model with gauge group
SU(2) and four massless matter fields in the fundamental representation. We
derive the exact mass formula of KK modes by using Seiberg--Witten theory. From
the mass formula and the D3-brane probe realization, we determine the spectrum
of KK modes of matter fields and gauge fields. As a result, we find that the
lightest KK state of gauge fields is stable for all the vacuum moduli space,
while the lightest KK state of matter fields decays easier than other KK states
in a region of the moduli space. The region becomes small as we decrease the
five-dimensional gauge coupling constant g_5, and vanishes as we take the limit
g_5->0. This result continuously connects the known KK spectrum in the weak
coupling limit and that in the strong coupling limit.Comment: 14 pages, 8 figure
USP8 prevents aberrant NF-κB and Nrf2 activation by counteracting ubiquitin signals from endosomes
K63-linked ubiquitin chains attached to plasma membrane proteins serve as tags for endocytosis and endosome-to-lysosome sorting. USP8 is an essential deubiquitinase for the maintenance of endosomal functions. Prolonged depletion of USP8 leads to cell death, but the major effects on cellular signaling pathways are poorly understood. Here, we show that USP8 depletion causes aberrant accumulation of K63-linked ubiquitin chains on endosomes and induces immune and stress responses. Upon USP8 depletion, two different decoders for K63-linked ubiquitin chains, TAB2/3 and p62, were recruited to endosomes and activated the TAK1-NF-κB and Keap1-Nrf2 pathways, respectively. Oxidative stress, an environmental stimulus that potentially suppresses USP8 activity, induced accumulation of K63-linked ubiquitin chains on endosomes, recruitment of TAB2, and expression of the inflammatory cytokine. The results demonstrate that USP8 is a gatekeeper of misdirected ubiquitin signals and inhibits immune and stress response pathways by removing K63-linked ubiquitin chains from endosomes.</p
Duality Between String Junctions and D-Branes on Del Pezzo Surfaces
We revisit local mirror symmetry associated with del Pezzo surfaces in
Calabi-Yau threefolds in view of five-dimensional N=1 E_N theories compactified
on a circle. The mirror partner of singular Calabi-Yau with a shrinking del
Pezzo four-cycle is described as the affine 7-brane backgrounds probed by a
D3-brane. Evaluating the mirror map and the BPS central charge we relate
junction charges to RR charges of D-branes wrapped on del Pezzo surfaces. This
enables us to determine how the string junctions are mapped to D-branes on del
Pezzo surfaces.Comment: 35 pages, Latex, 1 figure; typos corrected, references update
Prenatal diagnosis of severe mitochondrial diseases caused by nuclear gene defects: a study in Japan
Prenatal diagnoses of mitochondrial diseases caused by defects in nuclear DNA (nDNA) or mitochondrial DNA have been reported in several countries except for Japan. The present study aimed to clarify the status of prenatal genetic diagnosis of mitochondrial diseases caused by nDNA defects in Japan. A comprehensive genomic analysis was performed to diagnose more than 400 patients, of which, 13 families (16 cases) had requested prenatal diagnoses. Eight cases diagnosed with wild type homozygous or heterozygous variants same as either of the heterozygous parents continued the pregnancy and delivered healthy babies. Another eight cases were diagnosed with homozygous, compound heterozygous, or hemizygous variants same as the proband. Of these, seven families chose to terminate the pregnancy, while one decided to continue the pregnancy. Neonatal- or infantile-onset mitochondrial diseases show severe phenotypes and lead to lethality. Therefore, such diseases could be candidates for prenatal diagnosis with careful genetic counseling, and prenatal testing could be a viable option for families