111 research outputs found
Statistical analysis of the Central-Europe Seismicity
The aim of this paper is to characterize the spatio-temporal distribution of
Central-Europe seismicity. Speciļ¬cally, by using a non-parametric statistical
approach, the proportional hazard model, leading to an empirical estimation
of the hazard function, we provide some constrains on the time behavior of
earthquake generation mechanisms. The results indicate that the most conspic-
uous characteristics of MW 4.0+ earthquakes is a temporal clustering lasting
a couple of years. This suggests that the probability of occurrence increases
immediately after a previous event. After a few years, the process becomes
almost time independent. Furthermore, we investigate the cluster properties
of the seismicity of Central-Europe, by comparing the obtained result with the
one of synthetic catalogs generated by the epidemic type aftershock sequences
(ETAS) model, which previously have been successfully applied for short term
clustering. Our results indicate that the ETAS is not well suited to describe
the seismicity as a whole, while it is able to capture the features of the short-
term behaviour. Remarkably, similar results have been previously found for
Italy using a higher magnitude threshold
Centrifugal terms in the WKB approximation and semiclassical quantization of hydrogen
A systematic semiclassical expansion of the hydrogen problem about the
classical Kepler problem is shown to yield remarkably accurate results. Ad hoc
changes of the centrifugal term, such as the standard Langer modification where
the factor l(l+1) is replaced by (l+1/2)^2, are avoided. The semiclassical
energy levels are shown to be exact to first order in with all higher
order contributions vanishing. The wave functions and dipole matrix elements
are also discussed.Comment: 5 pages, to appear in Phys. Rev.
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CD40L-Tri, a novel formulation of recombinant human CD40L that effectively activates B cells
CD40L has a well-established role in enhancing the immunostimulatory capacity of normal and malignant B cells, but a formulation suitable for clinical use has not been widely available. Like other TNF family members, in vivo and in vitro activity of CD40L requires a homotrimeric configuration, and growing evidence suggests that bioactivity depends on higher-order clustering of CD40. We generated a novel formulation of human recombinant CD40L (CD40L-Tri) in which the CD40L extracellular domain and a trimerization motif are connected by a long flexible peptide linker. We demonstrate that CD40L-Tri significantly expands normal CD19+ B cells by over 20- to 30-fold over 14 days and induces B cells to become highly immunostimulatory antigen-presenting cells (APCs). Consistent with these results, CD40L-Tri-activated B cells could effectively stimulate antigen-specific T responses (against the influenza M1 peptide) from normal volunteers. In addition, CD40L-Tri could induce malignant B cells to become effective APCs, such that tumor-directed immune responses could be probed. Together, our studies demonstrate the potent immune-stimulatory effects of CD40L-Tri on B cells that enable their expansion of antigen-specific human T cells. The potent bioactivity of CD40L-Tri is related to its ability to self-multimerize, which may be facilitated by its long peptide linker. Electronic supplementary material The online version of this article (doi:10.1007/s00262-012-1331-4) contains supplementary material, which is available to authorized users
A Close Eye on the Eagle-Eyed Visual Acuity Hypothesis of Autism
Autism spectrum disorders (ASD) have been associated with sensory hypersensitivity. A recent study reported visual acuity (VA) in ASD in the region reported for birds of prey. The validity of the results was subsequently doubted. This study examined VA in 34 individuals with ASD, 16 with schizophrenia (SCH), and 26 typically developing (TYP). Participants with ASD did not show higher VA than those with SCH and TYP. There were no substantial correlations of VA with clinical severity in ASD or SCH. This study could not confirm the eagle-eyed acuity hypothesis of ASD, or find evidence for a connection of VA and clinical phenotypes. Research needs to further address the origins and circumstances associated with altered sensory or perceptual processing in ASD
Mobilization of healthy donors with plerixafor affects the cellular composition of T-cell receptor (TCR)-Ī±Ī²/CD19-depleted haploidentical stem cell grafts
Background: HLA-haploidentical hematopoietic stem cell transplantation (HSCT) is suitable for patients lacking related or unrelated HLA-matched donors. Herein, we investigated whether plerixafor (MZ), as an adjunct to G-CSF, facilitated the collection of mega-doses of hematopoietic stem cells (HSC) for TCR-Ī±Ī²/CD19-depleted haploidentical HSCT, and how this agent affects the cellular graft composition. Methods: Ninety healthy donors were evaluated. Single-dose MZ was given to 30 āpoor mobilizersā (PM) failing to attain ā„40 CD34+ HSCs/Ī¼L after 4 daily G-CSF doses and/or with predicted apheresis yields ā¤12.0x106 CD34+ cells/kg recipientās body weight. Results: MZ significantly increased CD34+ counts in PM. NaĆÆve/memory T and B cells, as well as natural killer (NK) cells, myeloid/plasmacytoid dendritic cells (DCs), were unchanged compared with baseline. MZ did not further promote the G-CSF-induced mobilization of CD16+ monocytes and the down-regulation of IFN-Ī³ production by T cells. HSC grafts harvested after G-CSF + MZ were enriched in myeloid and plasmacytoid DCs, but contained low numbers of pro-inflammatory 6-sulfo-LacNAc+ (Slan)-DCs. Finally, children transplanted with G-CSF + MZ-mobilized grafts received greater numbers of monocytes, myeloid and plasmacytoid DCs, but lower numbers of NK cells, NK-like T cells and Slan-DCs. Conclusions: MZ facilitates the collection of mega-doses of CD34+ HSCs for haploidentical HSCT, while affecting graft composition
Detection, purification and characterization of a lectin from freshwater green algae Spirogyra spp.
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