Transformation Decoupling Strategy based on Screw Theory for Deterministic Point Cloud Registration with Gravity Prior

Point cloud registration is challenging in the presence of heavy outlier correspondences. This paper focuses on addressing the robust correspondence-based registration problem with gravity prior that often arises in practice. The gravity directions are typically obtained by inertial measurement units (IMUs) and can reduce the degree of freedom (DOF) of rotation from 3 to 1. We propose a novel transformation decoupling strategy by leveraging screw theory. This strategy decomposes the original 4-DOF problem into three sub-problems with 1-DOF, 2-DOF, and 1-DOF, respectively, thereby enhancing the computation efficiency. Specifically, the first 1-DOF represents the translation along the rotation axis and we propose an interval stabbing-based method to solve it. The second 2-DOF represents the pole which is an auxiliary variable in screw theory and we utilize a branch-and-bound method to solve it. The last 1-DOF represents the rotation angle and we propose a global voting method for its estimation. The proposed method sequentially solves three consensus maximization sub-problems, leading to efficient and deterministic registration. In particular, it can even handle the correspondence-free registration problem due to its significant robustness. Extensive experiments on both synthetic and real-world datasets demonstrate that our method is more efficient and robust than state-of-the-art methods, even when dealing with outlier rates exceeding 99%

Xenon Pretreatment May Prevent Early Memory Decline after Isoflurane Anesthesia and Surgery in Mice

Postoperative cognitive decline (POCD) is a common complication following surgery, but its aetiology remains unclear. We hypothesized that xenon pretreatment prevents POCD by suppressing the systemic inflammatory response or through an associated protective signaling pathway involving heat shock protein 72 (Hsp72) and PI3-kinase. Twenty-four hours after establishing long-term memory using fear conditioning training, C57BL/6 adult male mice (n = 12/group) received one of the following treatments: 1) no treatment group (control); 2) 1.8% isoflurane anesthesia; 3) 70% xenon anesthesia; 4) 1.8% isoflurane anesthesia with surgery of the right hind leg tibia that was pinned and fractured; or 5) pretreatment with 70% xenon for 20 minutes followed immediately by 1.8% isoflurane anesthesia with the surgery described above. Assessments of hippocampal-dependent memory were performed on days 1 and 7 after treatment. Hsp72 and PI3-kinase in hippocampus, and plasma IL-1β, were measured using western blotting and ELISA respectively, from different cohorts on day 1 after surgery. Isoflurane induced memory deficit after surgery was attenuated by xenon pretreatment. Xenon pretreatment prevented the memory deficit typically seen on day 1 (P = 0.04) but not on day 7 (P = 0.69) after surgery under isoflurane anesthesia, when compared with animals that underwent surgery without pretreatment. Xenon pretreatment modulated the expression of Hsp72 (P = 0.054) but had no significant effect on PI3-kinase (P = 0.54), when compared to control. Xenon pretreatment also reduced the plasma level increase of IL-1β induced by surgery (P = 0.028). Our data indicated that surgery and/or Isoflurane induced memory deficit was attenuated by xenon pretreatment. This was associated with a reduction in the plasma level of IL-1β and an upregulation of Hsp72 in the hippocampus

Construction and analysis of causally dynamic hybrid bond graphs

Engineering systems are frequently abstracted to models with discontinuous behaviour (such as a switch or contact), and a hybrid model is one which contains continuous and discontinuous behaviours. Bond graphs are an established physical modelling method, but there are several methods for constructing switched or ‘hybrid’ bond graphs, developed for either qualitative ‘structural’ analysis or efficient numerical simulation of engineering systems. This article proposes a general hybrid bond graph suitable for both. The controlled junction is adopted as an intuitive way of modelling a discontinuity in the model structure. This element gives rise to ‘dynamic causality’ that is facilitated by a new bond graph notation. From this model, the junction structure and state equations are derived and compared to those obtained by existing methods. The proposed model includes all possible modes of operation and can be represented by a single set of equations. The controlled junctions manifest as Boolean variables in the matrices of coefficients. The method is more compact and intuitive than existing methods and dispenses with the need to derive various modes of operation from a given reference representation. Hence, a method has been developed, which can reach common usage and form a platform for further study

Uniqueness of Gibbs Measure for Models With Uncountable Set of Spin Values on a Cayley Tree

We consider models with nearest-neighbor interactions and with the set $[0,1]$ of spin values, on a Cayley tree of order $k\geq 1$. It is known that the "splitting Gibbs measures" of the model can be described by solutions of a nonlinear integral equation. For arbitrary $k\geq 2$ we find a sufficient condition under which the integral equation has unique solution, hence under the condition the corresponding model has unique splitting Gibbs measure.Comment: 13 page

Increased Number of Tc17 and Correlation with Th17 Cells in Patients with Immune Thrombocytopenia

BACKGROUND: IL-17-secreting CD8+ T cells (Tc17 subset) have recently been defined as a subpopulation of effector T cells implicated in the pathogenesis of autoimmune diseases. The role of Tc17 and correlation with Th17 cells in the pathophysiology of immune thrombocytopenia (ITP) remain unsettled. DESIGN AND METHODS: We studied 47 ITP patients (20 newly-diagnosed and 27 with complete response) and 34 healthy controls. IL-17-producing CD3+CD8+ cells (Tc17) and IL-17-producing CD3+CD8- cells (Th17) were evaluated by flow cytometry and expressed as a percentage of the total number of CD3+ cells. Specific anti-platelet glycoprotein (GP) GPIIb/IIIa and/or GPIb/IX autoantibodies were measured by modified monoclonal antibody specific immobilization of platelet antigens. Peripheral blood mononuclear cells of ITP patients were isolated, incubated in the presence of 0, 0.25, 0.5, or 1 µmol/L of dexamethasone for 72 h, and collected to detect Tc17 and Th17 cells by flow cytometric analysis. RESULTS: IL-17 was expressed on CD3+CD8- and CD3+CD8+ T cells. The percentages of Tc17 and Th17 cells in newly-diagnosed patients were significantly elevated compared to controls, and Tc17 was decreased after clinical treatment. The Th17∶Tc17 ratio was significantly lower in newly-diagnosed patients compared with controls, and was increased in patients who had complete response. There was a significantly positive correlation between Tc17 and Th17 cells in the control group, but not in the ITP patients. A positive correlation existed between Tc17 and the CD8∶CD4 ratio, as well as CD8+ cells in patients with ITP. The frequencies of Tc17 were marginally higher in autoantibody-negative patients than autoantibody-positive patients. Moreover, both Tc17 and Th17 cell percentages decreased as the concentration of dexamethasone in the culture media increased in ITP patients. CONCLUSIONS: Tc17 and the Th17 subset are involved in the immunopathology of ITP. Blocking the abnormally increased number of Tc17 may be a reasonable therapeutic strategy for ITP

Variation in promiscuity and sexual selection drives avian rate of Faster-Z evolution.

Higher rates of coding sequence evolution have been observed on the Z chromosome relative to the autosomes across a wide range of species. However, despite a considerable body of theory, we lack empirical evidence explaining variation in the strength of the Faster-Z Effect. To assess the magnitude and drivers of Faster-Z Evolution, we assembled six de novo transcriptomes, spanning 90 million years of avian evolution. Our analysis combines expression, sequence and polymorphism data with measures of sperm competition and promiscuity. In doing so, we present the first empirical evidence demonstrating the positive relationship between Faster-Z Effect and measures of promiscuity, and therefore variance in male mating success. Our results from multiple lines of evidence indicate that selection is less effective on the Z chromosome, particularly in promiscuous species, and that Faster-Z Evolution in birds is due primarily to genetic drift. Our results reveal the power of mating system and sexual selection in shaping broad patterns in genome evolution. This article is protected by copyright. All rights reserved

ROSAT X-ray sources in the field of the LMC I.Total LMC gas from the background AGN spectral fits

We analyzed a sample of 26 background X-ray sources in a ~60 square degree field of the Large Magellanic Cloud observed with the ROSAT PSPC. The sample has been selected from previously classified and optically identified X-ray sources. In addition pointlike and spectrally hard sources with at least 100 to 200 observed counts have been used for the analysis. We performed X-ray spectral fitting and derived total hydrogen absorbing column densities due to LMC gas in the range 10^20 - 2. 10^21 cm^-2. We compared these columns with the HI columns derived from a 21-cm Parkes survey of the LMC. For 7 optically identified sources we find, within the uncertainties derived from the X-ray spectral fit, agreement for both columns. For further 19 sources we constrain the LMC columns from the X-ray spectral fit assuming that the powerlaw photon index is that of AGN type spectra. We derive for 20 sources gas columns which are within the uncertainties in agreement with the HI columns. We derive for two background sources (RX J0536.9-6913 and RX J0547.0-7040) hydrogen absorbing column densities due to LMC gas, which are in excess to the HI columns. These sources - located in regions of large (~3. 10^21 cm^-2) LMC HI column densities - could be seen through additional gas which may be warm and diffuse, cold or molecular. For 10 sources we derive upper limits for the gas columns additional to HI and constrain the molecular mass fraction to <(30-140)%.Comment: Accepted by A&

Loss of exogenous androgen dependence by prostate tumor cells is associated with elevated glucuronidation potential

Prostate epithelial cells control the potency and availability of androgen hormones in part by inactivation and elimination. UDP-glucose dehydrogenase (UGDH) catalyzes the NAD+-dependent oxidation of UDP-glucose to UDP-glucuronate, an essential precursor for androgen inactivation by the prostate glucuronidation enzymes UGT2B15 and UGT2B17. UGDH expression is androgen stimulated, which increases the production of UDP-glucuronate, and fuels UGT-catalyzed glucuronidation. In this study, we compared the glucuronidation potential and its impact on androgen-mediated gene expression in an isogenic LNCaP model for androgen dependent versus castration resistant prostate cancer. Despite significantly lower androgen-glucuronide output, LNCaP 81 castration resistant tumor cells expressed higher levels of UGDH, UGT2B15, and UGT2B17. However, the magnitude of androgen-activated UGDH and PSA expression, as well as the AR-dependent repression of UGT2B15 and UGT2B17, was blunted several-fold in these cells. Consistent with these results, the ligand-activated binding of AR to the PSA promoter and subsequent transcriptional activation were also significantly reduced in castration resistant cells. Analysis of the UDP-sugar pools and flux through pathways downstream of UDP-glucuronate production revealed that these glucuronidation precursor metabolites were channeled through proteoglycan and glycosaminoglycan biosynthetic pathways, leading to increased surface expression of Notch 1. Knockdown of UGDH diminished Notch1 and increased glucuronide output. Overall, these results support a model in which the aberrant partitioning of UDP-glucuronate and other UDP-sugars into alternative pathways during androgen deprivation contributes to the loss of prostate tumor cell androgen sensitivity by promoting altered cell surface proteoglycan expression

Loss of exogenous androgen dependence by prostate tumor cells is associated with elevated glucuronidation potential

Prostate epithelial cells control the potency and availability of androgen hormones in part by inactivation and elimination. UDP-glucose dehydrogenase (UGDH) catalyzes the NAD+-dependent oxidation of UDP-glucose to UDP-glucuronate, an essential precursor for androgen inactivation by the prostate glucuronidation enzymes UGT2B15 and UGT2B17. UGDH expression is androgen stimulated, which increases the production of UDP-glucuronate, and fuels UGT-catalyzed glucuronidation. In this study, we compared the glucuronidation potential and its impact on androgen-mediated gene expression in an isogenic LNCaP model for androgen dependent versus castration resistant prostate cancer. Despite significantly lower androgen-glucuronide output, LNCaP 81 castration resistant tumor cells expressed higher levels of UGDH, UGT2B15, and UGT2B17. However, the magnitude of androgen-activated UGDH and PSA expression, as well as the AR-dependent repression of UGT2B15 and UGT2B17, was blunted several-fold in these cells. Consistent with these results, the ligand-activated binding of AR to the PSA promoter and subsequent transcriptional activation were also significantly reduced in castration resistant cells. Analysis of the UDP-sugar pools and flux through pathways downstream of UDP-glucuronate production revealed that these glucuronidation precursor metabolites were channeled through proteoglycan and glycosaminoglycan biosynthetic pathways, leading to increased surface expression of Notch 1. Knockdown of UGDH diminished Notch1 and increased glucuronide output. Overall, these results support a model in which the aberrant partitioning of UDP-glucuronate and other UDP-sugars into alternative pathways during androgen deprivation contributes to the loss of prostate tumor cell androgen sensitivity by promoting altered cell surface proteoglycan expression

Mesures in-situ par incandescence induite par Laser des tailles de nano-particules lors de la synthèse de nanotubes de carbone par dépôt chimique en phase vapeur

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