Hypernuclear spectroscopy with electron beams and future prospects

Hypernuclear spectroscopy with electron beams was initiated by JLab E89-009 at JLab Hall-C in 2000. After the successful pilot experiment, improved experiments introducing new experimental techniques such as RICH, new spectrometers (HKS, HES) and optimized configuration of electron spectrometer were performed at JLab Hall-A and Hall-C. In this article, progresses of the hypernuclear spectroscopy with electron beams in this decade are reviewed and future prospects of this research subject at JLab and MAMI-C are discusse

On the Complexity of Tree Edit Distance with Variables

In this paper, we propose tree edit distance with variables, which is an extension of the tree edit distance to handle trees with variables and has a potential application to measuring the similarity between mathematical formulas. We analyze the computational complexity of several variants of this model. In particular, we show that the problem is NP-complete for ordered trees. We also show for unordered trees that the problem of deciding whether or not the distance is 0 is graph isomorphism complete but can be solved in polynomial time if the maximum outdegree of input trees is bounded by a constant. We also present parameterized and exponential-time algorithms for ordered and unordered cases, respectively

Discriminating Minimal SUGRA and Minimal Gauge Mediation Models at the Early LHC

Among various supersymmetric (SUSY) standard models, the gravity mediation model with a neutralino LSP and the gauge mediation model with a very light gravitino are attractive from the cosmological view point. These models have different scales of SUSY breaking and their underlying physics in high energy is quite different. However, if the sparticles' decay into the gravitino is prompt in the latter case, their collider signatures can be similar: multiple jets and missing transverse momentum. In this paper, we study the discrimination between these models in minimal cases at the LHC based on the method using the significance variables in several different modes and show the discrimination is possible at a very early stage after the discovery.Comment: 29 pages, 3 figures, captions improved, typos corrected, appendix added, version published in JHE

Primordial magnetic fields from second-order cosmological perturbations: Tight coupling approximation

We explore the possibility of generating large-scale magnetic fields from second-order cosmological perturbations during the pre-recombination era. The key process for this is Thomson scattering between the photons and the charged particles within the cosmic plasma. To tame the multi-component interacting fluid system, we employ the tight coupling approximation. It is shown that the source term for the magnetic field is given by the vorticity, which signals the intrinsically second-order quantities, and the product of the first order perturbations. The vorticity itself is sourced by the product of the first-order quantities in the vorticity evolution equation. The magnetic fields generated by this process are estimated to be $\sim 10^{-29}$Gauss on the horizon scale at the recombination epoch. Although our rough estimate suggests that the current generation mechanism can work even on smaller scales, more careful investigation is needed to make clear whether it indeed works in a wide range of spatial scales.Comment: 10pages, minor corrections, accepted for publication in Class. Quant. Gra

Fatal bacteremia due to immotile Vibrio cholerae serogroup O21 in Vientiane, Laos – a case report

<p>Abstract</p> <p>Background</p> <p>Human infections with non-O1, non-O139 <it>V. cholerae </it>have been described from Laos. Elsewhere, non cholera-toxin producing, non-O1, non-O139 <it>V. cholerae </it>have been described from blood cultures and ascitic fluid, although they are exceedingly rare isolates.</p> <p>Case presentation</p> <p>We describe a farmer who died with <it>Vibrio cholerae </it>O21 bacteremia and peritonitis in Vientiane, Laos, after eating partially cooked apple snails (<it>Pomacea canaliculata</it>) and mussels (<it>Ligumia </it>species). The cultured <it>V. cholerae </it>were non-motile. PCR detected <it>ompW </it>and <it>toxR </it>gene regions but not the <it>ctxA, ompU, omp K </it>and <it>TCP </it>gene regions. Although the organisms lacked flagellae on scanning electron microscopy, they possessed the <it>Vibrio </it>flagellin <it>flaA </it>gene.</p> <p>Conclusion</p> <p>Severe bacteremic non-O1, non-O139 <it>V. cholerae </it>is reported from Laos. The organisms were unusual in being non-motile. They possessed the <it>Vibrio </it>flagellin <it>flaA </it>gene. Further research to determine the reasons for the non-motility and virulence is required.</p

Anti-centromere antibody-seropositive Sjögren's syndrome differs from conventional subgroup in clinical and pathological study

<p>Abstract</p> <p>Background</p> <p>To clarify the clinicopathological characteristics of primary Sjögren's syndrome (pSS) with anti-centromere antibody (ACA).</p> <p>Methods</p> <p>Characteristics of 14 patients of pSS with ACA were evaluated. All patients were anti-SS-A/Ro and SS-B/La antibodies negative (ACA+ group) without sclerodactyly. The prevalence of Raynaud's phenomenon (RP), titer of IgG and focus score (FS) in the minor salivary glands (MSGs) were determined. Quantification analysis of Azan Mallory staining was performed to detect collagenous fiber. Forty eight patients in whom ACA was absent were chosen as the conventional (ACA-) pSS group.</p> <p>Results</p> <p>Prevalence of ACA+ SS patients was 14 out of 129 (10.85%) pSS patients. RP was observed in 61.5% of the patients with ACA. The level of IgG in the ACA+ group was significantly lower than that of the ACA- group (p = 0.018). Statistical difference was also found in the FS of MSGs from the ACA+ group (1.4 ± 1.0) as compared with the ACA- group (2.3 ± 1.6) (p = 0.035). In contrast, the amount of fibrous tissue was much higher in the ACA+ group (65052.2 ± 14520.6 μm²versus 26251.3 ± 14249.8 μm²) (p = 1.3 × 10^-12).</p> <p>Conclusions</p> <p>Low cellular infiltration but with an increase in fibrous tissues may explain the clinical feature of a high prevalence of RP and normal IgG concentration in ACA+ pSS.</p

Delayed Pion Spectroscopy of Hypernuclei

New possibilities of hypernuclear studies at modern electron accelerators based on recently developed radio frequency photomultiplier tubes are discussed

Hepatocelluar nodules in liver cirrhosis: hemodynamic evaluation (angiography-assisted CT) with special reference to multi-step hepatocarcinogenesis

To understand the hemodynamics of hepatocellular carcinoma (HCC) is important for the precise imaging diagnosis and treatment, because there is an intense correlation between their hemodynamics and pathophysiology. Angiogenesis such as sinusoidal capillarization and unpaired arteries shows gradual increase during multi-step hepatocarcinogenesis from high-grade dysplastic nodule to classic hypervascular HCC. In accordance with this angiogenesis, the intranodular portal supply is decreased, whereas the intranodular arterial supply is first decreased during the early stage of hepatocarcinogenesis and then increased in parallel with increasing grade of malignancy of the nodules. On the other hand, the main drainage vessels of hepatocellular nodules change from hepatic veins to hepatic sinusoids and then to portal veins during multi-step hepatocarcinogenesis, mainly due to disappearance of the hepatic veins from the nodules. Therefore, in early HCC, no perinodular corona enhancement is seen on portal to equilibrium phase CT, but it is definite in hypervascular classical HCC. Corona enhancement is thicker in encapsulated HCC and thin in HCC without pseudocapsule. To understand these hemodynamic changes during multi-step hepatocarcinogenesis is important, especially for early diagnosis and treatment of HCCs

Developmental profile of localized spontaneous Ca2+ release events in the dendrites of rat hippocampal pyramidal neurons

Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Cell Calcium 52 (2012): 422-432, doi:10.1016/j.ceca.2012.08.001.Recent experiments demonstrate that localized spontaneous Ca2+ release events can be detected in the dendrites of pyramidal cells in the hippocampus and other neurons (J. Neurosci. 29:7833-7845, 2009). These events have some properties that resemble ryanodine receptor mediated “sparks” in myocytes, and some that resemble IP3 receptor mediated “puffs” in oocytes. They can be detected in the dendrites of rats of all tested ages between P3 and P80 (with sparser sampling in older rats), suggesting that they serve a general signaling function and are not just important in development. However, in younger rats the amplitudes of the events are larger than the amplitudes in older animals and almost as large as the amplitudes of Ca2+ signals from backpropagating action potentials (bAPs). The rise time of the event signal is fast at all ages and is comparable to the rise time of the bAP fluorescence signal at the same dendritic location. The decay time is slower in younger animals, primarily because of weaker Ca2+ extrusion mechanisms at that age. Diffusion away from a brief localized source is the major determinant of decay at all ages. A simple computational model closely simulates these events with extrusion rate the only age dependent variable.Supported in part by NIH grant NS-016295