677 research outputs found

    Gaussian Process Modelling for Improved Resolution in Faraday Depth Reconstruction

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    The incomplete sampling of data in complex polarization measurements from radio telescopes negatively affects both the rotation measure (RM) transfer function and the Faraday depth spectra derived from these data. Such gaps in polarization data are mostly caused by flagging of radio frequency interference and their effects worsen as the percentage of missing data increases. In this paper we present a novel method for inferring missing polarization data based on Gaussian processes (GPs). Gaussian processes are stochastic processes that enable us to encode prior knowledge in our models. They also provide a comprehensive way of incorporating and quantifying uncertainties in regression modelling. In addition to providing non-parametric model estimates for missing values, we also demonstrate that Gaussian process modelling can be used for recovering rotation measure values directly from complex polarization data, and that inferring missing polarization data using this probabilistic method improves the resolution of reconstructed Faraday depth spectra.Comment: 16 pages, 10 figures, submitted to MNRA

    Pathogenic effect of interleukin-17A in induction of Sjogren's syndrome-like disease using adenovirus-mediated gene transfer

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    Introduction Sjögren's syndrome (SS) involves a chronic, progressive inflammation primarily of the salivary and lacrimal glands leading to decreased levels of saliva and tears resulting in dry mouth and dry eye diseases. Seminal findings regarding TH17 cell populations that secrete predominantly interleukin (IL)-17A have been shown to play an important role in an increasing number of autoimmune diseases, including SS. In the present study, we investigated the function of IL-17A on the development and onset of SS. Methods Adenovirus serotype 5 (Ad5) vectors expressing either IL-17A or LacZ were infused via retrograde cannulation into the salivary glands of C57BL/6J mice between 6 and 8 weeks of age or between 15 and 17 weeks of age. The mice were characterized for SS phenotypes. Results Disease profiling indicated that SS-non-susceptible C57BL/6J mice whose salivary glands received the Ad5-IL17A vector developed a SS-like disease profile, including the appearance of lymphocytic foci, increased cytokine levels, changes in antinuclear antibody profiles, and temporal loss of saliva flow. Conclusions Induction of SS pathology by IL-17A in SS-non-susceptible mice strongly suggests that IL-17A is an important inflammatory cytokine in salivary gland dysfunction. Thus, localized anti-IL17 therapy may be effective in preventing glandular dysfunction.National Institute of Dental and Craniofacial Research (U.S.) (PHS Grants K99DE018958)National Institute of Allergy and Infectious Diseases (U.S.) (R21AI081952)Sjogren's Syndrome FoundationUniversity of Florida. Center for Orphaned Autoimmune DisordersNational Institute of Dental and Craniofacial Research (U.S.) (Intramural research grant)National Institutes of Health (U.S.

    Results from the DELCODE study

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    Previous studies have demonstrated increased tau plasma levels in patients with Alzheimer’s disease (AD) and mild cognitive impairment (MCI) due to AD. Much less is known whether increased tau plasma levels can already be detected in the pre-MCI stage of subjective cognitive decline (SCD). In the present study we measured tau plasma levels in 111 SCD patients and 134 age- and gender-matched cognitively healthy controls participating in the DZNE (German Center for Neurodegenerative Diseases) longitudinal study on cognition and dementia (DELCODE). Tau plasma levels were measured using ultra-sensitive, single-molecule array (Simoa) technology. We found no significant different tau plasma levels in SCD (3.4 pg/ml) compared with healthy controls (3.6 pg/ml) after controlling for age, gender, and education (p = 0.137). In addition, tau plasma levels did not correlate with Aβ42 (r = 0.073; p = 0.634), tau (r = −0.179; p = 0.240), and p-tau181 (r = −0.208; p = 0.171) cerebrospinal fluid (CSF) levels in a subgroup of 45 SCD patients with available CSF. In conclusion, plasma tau is not increased in SCD patients. In addition, the lack of correlation between tau in plasma and CSF in the examined cohort suggests that tau levels are affected by different factors in both biofluids

    Results from the DELCODE study

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    Previous studies have demonstrated increased tau plasma levels in patients with Alzheimer’s disease (AD) and mild cognitive impairment (MCI) due to AD. Much less is known whether increased tau plasma levels can already be detected in the pre-MCI stage of subjective cognitive decline (SCD). In the present study we measured tau plasma levels in 111 SCD patients and 134 age- and gender-matched cognitively healthy controls participating in the DZNE (German Center for Neurodegenerative Diseases) longitudinal study on cognition and dementia (DELCODE). Tau plasma levels were measured using ultra-sensitive, single-molecule array (Simoa) technology. We found no significant different tau plasma levels in SCD (3.4 pg/ml) compared with healthy controls (3.6 pg/ml) after controlling for age, gender, and education (p = 0.137). In addition, tau plasma levels did not correlate with Aβ42 (r = 0.073; p = 0.634), tau (r = −0.179; p = 0.240), and p-tau181 (r = −0.208; p = 0.171) cerebrospinal fluid (CSF) levels in a subgroup of 45 SCD patients with available CSF. In conclusion, plasma tau is not increased in SCD patients. In addition, the lack of correlation between tau in plasma and CSF in the examined cohort suggests that tau levels are affected by different factors in both biofluids

    The problems and measures of sharing of science an technology resources in our country

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    人类经济社会发展正在经历着重大转型,科技创新的主导作用日益显著,科技资源的拥有、配置和利用方式的优劣,特别是共享程度的高低,日益成为决定国家科技强弱甚至国家兴衰的关键因素之一。因此,关于科技资源共享的研究就受到越来越多的国内外专家的关注。 第一章在理清资源、科技资源概念的基础上,界定了科技资源的内涵。指出,科技资源是进行科技活动所需要的诸投入要素,主要包括科技人力资源、科技财力资源、科技物力资源和科技信息资源四个方面。 第二章在考察共享及其相关理论的基础上,对科技资源共享作了属性判断分析,并指出科技资源共享的意义,即在于公开并整合现有的科技资源,实现科技资源的科学、高效使用和管理,使之创造...Science and technology innovation has increasingly shown its leading function with a big turn in the economic and social development of mankind society. To significantly own、better configure and equitably use,especially fully share science and technology resources is becoming increasingly key factors to influence development of national science and technology or even national overall power, so sha...学位:哲学硕士院系专业:人文学院哲学系_科学技术哲学学号:1032005130017

    P2Y13 receptors regulate microglial morphology, surveillance, and resting levels of interleukin 1β release

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    Microglia sense their environment using an array of membrane receptors. While P2Y12 receptors are known to play a key role in targeting directed motility of microglial processes to sites of damage where ATP/ADP is released, little is known about the role of P2Y13 , which transcriptome data suggest is the second most expressed neurotransmitter receptor in microglia. We show that, in patch-clamp recordings in acute brain slices from mice lacking P2Y13 receptors, the THIK-1 K+ current density evoked by ADP activating P2Y12 receptors was increased by ~50%. This increase suggested that the P2Y12 -dependent chemotaxis response should be potentiated; however, the time needed for P2Y12 -mediated convergence of microglial processes onto an ADP-filled pipette or to a laser ablation was longer in the P2Y13 KO. Anatomical analysis showed that the density of microglia was unchanged, but that they were less ramified with a shorter process length in the P2Y13 KO. Thus, chemotactic processes had to grow further and so arrived later at the target, and brain surveillance was reduced by ~30% in the knock-out. Blocking P2Y12 receptors in brain slices from P2Y13 KO mice did not affect surveillance, demonstrating that tonic activation of these high-affinity receptors is not needed for surveillance. Strikingly, baseline interleukin-1β release was increased fivefold while release evoked by LPS and ATP was not affected in the P2Y13 KO, and microglia in intact P2Y13 KO brains were not detectably activated. Thus, P2Y13 receptors play a role different from that of their close relative P2Y12 in regulating microglial morphology and function

    Quark masses and mixings in the RS1 model with a condensing 4th generation

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    We study the hierarchy of quark masses and mixings in a model based on a 5-dimensional spacetime with constant curvature of Randall-Sundrum type with two branes, where the Electroweak Symmetry Breaking is caused dynamically by the condensation of a 4th generation of quarks, due to underlying physics from the 5D bulk and the first KK gluons. We first study the hierarchy of quark masses and mixings that can be obtained from purely adjusting the profile localizations, finding that realistic masses are not reproduced unless non trivial hierarchies of underlying 4-fermion interactions from the bulk are included. Then we study global U(1) symmetries that can be imposed in order to obtain non-symmetric modified Fritzsch-like textures in the mass matrices that reproduce reasonably well quark masses and CKM mixings.Comment: Minor changes. Version accepted for publication in JHE
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