25,892 research outputs found
A Multi-Scan Labeled Random Finite Set Model for Multi-object State Estimation
State space models in which the system state is a finite set--called the
multi-object state--have generated considerable interest in recent years.
Smoothing for state space models provides better estimation performance than
filtering by using the full posterior rather than the filtering density. In
multi-object state estimation, the Bayes multi-object filtering recursion
admits an analytic solution known as the Generalized Labeled Multi-Bernoulli
(GLMB) filter. In this work, we extend the analytic GLMB recursion to propagate
the multi-object posterior. We also propose an implementation of this so-called
multi-scan GLMB posterior recursion using a similar approach to the GLMB filter
implementation
Dysregulation of of phospholipid-specific phagocytosis by B1 B cells in diet-induced obese mice
B1 B cells have received increasing attention recently due to their newly discovered phagocytic and microbicidal capabilities. Several studies have demonstrated that B1 cells can phagocytize polystyrene fluorescent particles, bacteria (Staphylococcus aureus, Escherichia coli), and even apoptotic cells. Nevertheless, little is known about the biological significance of this seemingly redundant function of B1 B cells as compared to that of conventional phagocytes. Here we investigate the unique phosphotidylcholine (PtC)-specific B1 B cell phagocytosis. PtC is a major phospholipid in the biological membrane and a classical antigen recognized by B1 B cell-derived natural antibodies. These antibodies play important roles in immune defense as well as tissue homeostasis. Here we report that B1 cells preferentially phagocytose PtC-coated beads, differing from that of conventional macrophages. We further attest that these beads were truly internalized and subsequently fused with hydrolytic lysosomes indicated by increasing fluorescent intensity of a pH-sensitive dye. Despite the differences in antigen specificity, phagocytosis of both B1 cells and macrophages can be inhibited by the microtubule-inhibitor, Colchicine, in a dose-dependent manner. Most intriguingly, upon chronic high-fat diet (HFD) consumption by the host, B1 cell phagocytosis starts to lose antigen-specificity for PtC. Morphologically, some of these B1 B cells in DIO mice show enlarged cytosol and engulfed more beads, indicating a transition to macrophage-like cells. Our study suggests for the first time that B1 B cells have unique phospholipid-specific phagocytosis capacity, which is affected by diet-induced obesity
Feasibility of Integrating Tripterygium wilfordii into Modern Cancer Therapy for Increased Efficacy with Minimal Toxicity
Cancer is the second leading cause of death in the U.S., and millions of novel cancer cases are being diagnosed each year. While chemotherapy and ionizing radiation are effective treatments against these malignant tumors, the adverse effects that accompany such treatments are devastating. In order to find alternative treatment methods with less side effects, we turn to Eastern herbal medicine. Recent scientific research has found that Tripterygium wilfordii, an herbal medicine traditionally used to treat inflammation in China, contains compounds (triptolide and celastrol) that prevent the growth of solid tumors, induce apoptosis, and prevent metastasis of developed tumors. Investigations on these compounds on various cancer cells lines (in vitro and in vivo) have revealed insight into their mechanism, mode of action, and toxicity. In order to circumvent the potentially fatal side effects of triptolide and celastrol, it was proposed that roots of T. wilfordii, from which the compounds are extracted, be used as a treatment for cancer. Methods for testing the efficacy and toxicity of the roots on the different cell lines previously studied are outlined in this paper. If the results from the proposed experiment conflict with expectation, then future studies on combination drugs using triptolide and celastrol with other non-bioactive compounds within the roots should be done to develop new anti-cancer drugs with low toxicity
The "hit" problem of five variables in the generic degree and its application
Let be the graded polynomial algebra
over the prime field of two elements, , in variables , each of degree . We are interested in the Peterson "hit"
problem of finding a minimal set of generators for as a graded left
module over the mod-2 Steenrod algebra, . For it
is still open.
In this paper, we study the hit problem of five variables in a generic
degree. By using this result, we survey Singer's conjecture for the fifth
algebraic transfer in the respective degrees. This gives an efficient method to
study the algebraic transfer and it is different from the ones of Singer.Comment: 29 page
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