154 research outputs found
BPS Dynamics of Triple (p,q) String Junction
We study dynamics of triple junction of (p,q) strings in Type IIB string
theory. We probe tension and mass density of (p,q) strings by studying harmonic
fluctuations of the triple junction. We show that they agree perfectly with BPS
formula provided suitable geometric interpretation of the junction is given. We
provide a precise statement of BPS limit and force-balance property. At weak
coupling and sufficiently dense limit, we argue that (p,q)-string embedded in
string network is a `wiggly string', whose low-energy dynamics can be described
via renormalization group evolved, smooth effective non-relativistic string. We
also suggest the possibility that, upon Type IIB strings are promoted to
M-theory membrane, there can exist `evanescent' bound-states at triple junction
in the continuum.Comment: 11 pages, Latex, 3 figures, typos correcte
Approximation of most penetrating particle size for fibrous filters considering Cunningham slip correction factor
In the estimation of the aerosol single fiber efficiency using fibrous filters, there is a size range, where the particles penetrate most effectively through the fibrous collectors, and corresponding minimum single fiber efficiency. For small particles in which the diffusion mechanism is dominant, the Cunningham slip correction factor (Cc) affects the single fiber efficiency and the most penetrating particle size (MPPS). Therefore, for accurate estimation, Cc is essential to be considered. However, many previous studies have neglected this factor because of its complexity and the associated difficulty in deriving the appropriate parameterization particularly for the MPPS. In this study, the expression for the MPPS, and the corresponding expression for the minimum single fiber efficiency are analytically derived, and the effects of Cc are determined. In order to accommodate the slip factor for all particle-size ranges, Cc is simplified and modified. Overall, the obtained analytical expression for the MPPS is in a good agreement with the exact solution
On the semi-inner product in locally convex spaces
The purpose of this paper is to introduce the concept of semi-inner products in locally
convex spaces and to give some basic properties
Atherosclerotic Progression Attenuates the Expression of Nogo-B in Autopsied Coronary Artery: Pathology and Virtual Histology Intravascular Ultrasound Analysis
The relation of Nogo-B to atherosclerotic plaque progression is not well understood. Thus, the purpose of this study was to assess the expression of Nogo-B in fibroatheromas (FA) of different stages, classified using virtual histology intravascular ultrasound (VH-IVUS) analysis in 19 autopsied cases of non-sudden cardiac death. VH-IVUS imaging analysis was performed 30 mm from the ostium of each coronary artery. VH-IVUS revealed 11 early FAs (34.5±8.3 yr), 12 late FAs (42.6±16.6 yr), 8 thick-cap FAs (TkCFAs) (46.4±11.1 yr), and 6 thin-cap FAs (TCFAs) (51.8±6.8 yr). TkCFAs and TCFAs were defined as advanced FA. FA progression advanced with age (P=0.04). VH-IVUS analysis of small, early FAs showed smaller necrotic cores and relatively less calcium compared to more advanced FAs with large necrotic cores (P<0.001). Histopathology and immunohistochemical stains demonstrated that early or late FAs had smaller necrotic cores, less empty space of decalcification, and greater Nogo-B expression compared to advanced FAs (vs. early FA, P=0.013; vs. late FA, P=0.008, respectively). These findings suggest that FA progression is inversely associated with Nogo-B expression. Local reduction of Nogo-B may contribute to plaque formation and/or instability
Extremal black holes in the Ho\v{r}ava-Lifshitz gravity
We study the near-horizon geometry of extremal black holes in the
Ho\v{r}ava-Lifshitz gravity with a flow parameter . For ,
near-horizon geometry of extremal black holes are AdS with
different radii, depending on the (modified) Ho\v{r}ava-Lifshitz gravity. For
, the radius of is negative, which means
that the near-horizon geometry is ill-defined and the corresponding
Bekenstein-Hawking entropy is zero. We show explicitly that the entropy
function approach does not work for obtaining the Bekenstein-Hawking entropy of
extremal black holes.Comment: 18 pages, v2:some points on Lifshitz black holes claified, v3:
version to appear in EJP
Suppression of oxidative stress by grape seed supplementation in rats
Polyphenol-rich grape seeds have a beneficial effect on human health. The present study was performed to investigate the effects of grape seeds on antioxidant activities in rats. Male Sprague-Dawley rats were randomly divided into a control diet group (C), a high-fat diet group (HF), a 5% grape seed-supplemented control diet group (G), and a 5% grape seed-supplemented high-fat diet group (HG). Dietary supplementation with grape seeds reduced serum concentrations of lipid peroxides compared with those in the C and HF groups. The hepatic level of lipid peroxides decreased significantly in the grape seed groups compared with that in the C and HF groups. Superoxide dismutase activity in the G group increased significantly compared with that in the C group. Catalase activity tended to be higher by feeding grape seeds. The grape seed diet increased glutathione peroxidase activity in the C group. Glutathione-S-transferase activity increased significantly in the G group compared with that in the C group. Hepatic content of total glutathione increased significantly in the HG group but decreased significantly in the HF group. The ratio of reduced glutathione and oxidized glutathione increased by feeding the grape seed diet. Total vitamin A concentration was significantly higher in HG group than in other groups. Liver tocopherol content of the G and HG groups was significantly higher than that of the control groups. These results suggest that dietary supplementation with grape seeds is beneficial for suppressing lipid peroxidation in high fat-fed rats
Chromosomal Inversions between Human and Chimpanzee Lineages Caused by Retrotransposons
The long interspersed element-1 (LINE-1 or L1) and Alu elements are the most abundant mobile elements comprising 21% and 11% of the human genome, respectively. Since the divergence of human and chimpanzee lineages, these elements have vigorously created chromosomal rearrangements causing genomic difference between humans and chimpanzees by either increasing or decreasing the size of genome. Here, we report an exotic mechanism, retrotransposon recombination-mediated inversion (RRMI), that usually does not alter the amount of genomic material present. Through the comparison of the human and chimpanzee draft genome sequences, we identified 252 inversions whose respective inversion junctions can clearly be characterized. Our results suggest that L1 and Alu elements cause chromosomal inversions by either forming a secondary structure or providing a fragile site for double-strand breaks. The detailed analysis of the inversion breakpoints showed that L1 and Alu elements are responsible for at least 44% of the 252 inversion loci between human and chimpanzee lineages, including 49 RRMI loci. Among them, three RRMI loci inverted exonic regions in known genes, which implicates this mechanism in generating the genomic and phenotypic differences between human and chimpanzee lineages. This study is the first comprehensive analysis of mobile element bases inversion breakpoints between human and chimpanzee lineages, and highlights their role in primate genome evolution
CoNIC Challenge: Pushing the Frontiers of Nuclear Detection, Segmentation, Classification and Counting
Nuclear detection, segmentation and morphometric profiling are essential in
helping us further understand the relationship between histology and patient
outcome. To drive innovation in this area, we setup a community-wide challenge
using the largest available dataset of its kind to assess nuclear segmentation
and cellular composition. Our challenge, named CoNIC, stimulated the
development of reproducible algorithms for cellular recognition with real-time
result inspection on public leaderboards. We conducted an extensive
post-challenge analysis based on the top-performing models using 1,658
whole-slide images of colon tissue. With around 700 million detected nuclei per
model, associated features were used for dysplasia grading and survival
analysis, where we demonstrated that the challenge's improvement over the
previous state-of-the-art led to significant boosts in downstream performance.
Our findings also suggest that eosinophils and neutrophils play an important
role in the tumour microevironment. We release challenge models and WSI-level
results to foster the development of further methods for biomarker discovery
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
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