885 research outputs found

    Informative Path Planning for Active Field Mapping under Localization Uncertainty

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    Information gathering algorithms play a key role in unlocking the potential of robots for efficient data collection in a wide range of applications. However, most existing strategies neglect the fundamental problem of the robot pose uncertainty, which is an implicit requirement for creating robust, high-quality maps. To address this issue, we introduce an informative planning framework for active mapping that explicitly accounts for the pose uncertainty in both the mapping and planning tasks. Our strategy exploits a Gaussian Process (GP) model to capture a target environmental field given the uncertainty on its inputs. For planning, we formulate a new utility function that couples the localization and field mapping objectives in GP-based mapping scenarios in a principled way, without relying on any manually tuned parameters. Extensive simulations show that our approach outperforms existing strategies, with reductions in mean pose uncertainty and map error. We also present a proof of concept in an indoor temperature mapping scenario.Comment: 8 pages, 7 figures, submission (revised) to Robotics & Automation Letters (and IEEE International Conference on Robotics and Automation

    Influence of Nanosilica on Mechanical Properties, Sorptivity, and Microstructure of Lightweight Concrete

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    This study presents the results of an experimental investigation of the effects of nanosilica (NS) on the strength development, transport properties, thermal conductivity, air-void, and pore characteristics of lightweight aggregate concrete (LWAC), with an oven-dry density 1 wt.%). NS contributed to compaction of the LWAC matrix and a modification of the air-void system, by increasing the amount of solid content and refining the fine pore structure, which translated to a noticeable improvement in mechanical and transport properties. On the other hand, NS decreased the consistency, while increasing the viscosity of the fresh mixture. An increment of superplasticizer (SP), along with a decrement of stabilizer (ST) dosages, are thus required.EC/H2020/841592/EU/Ultra-Lightweight Concrete for 3D printing technologies/Ultra-LightCon-3DDFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität Berli

    Spatial localisation in autism: evidence for differences in early cortical visual processing.

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    BACKGROUND: Vision in people with autism spectrum conditions (ASC) is reported to be different from people without ASC, but the neural level at which the differences begin to occur is not yet known. Here we examine two variants of a vernier acuity task to determine if differences are evident in early visual processing. FINDINGS: Abutting and separated vernier acuity was assessed in 16 people with ASC and 14 matched controls. In controls, abutting and separated thresholds were unrelated (r = 0.13, p = 0.65), suggesting thresholds are determined by two separate mechanisms. In contrast, the abutting and separated thresholds of ASC observers were strongly correlated (r = 0.88, p < 0.0001), with separated thresholds tending towards being superior to those of controls [t(28) = -2.46, p = 0.02]. CONCLUSIONS: The findings suggest the mechanisms employed by ASC observers in separated vernier tasks are different to those of controls. This psychophysical evidence suggests that visual differences in ASC may begin at an early cortical stage of visual processing.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Two-year follow-up of macaques developing intermittent control of the human immunodeficiency virus homolog simian immunodeficiency virus SIVmac251 in the chronic phase of infection

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    Off-therapy control of viremia by HIV-infected individuals has been associated with two likely players: a restricted viral reservoir and an efficient cell-mediated immune response. We previously showed that a combination of highly suppressive antiretroviral therapy and two experimental drugs, i.e., auranofin and buthionine sulfoximine, was able to reduce the viral reservoir, elicit efficient cell-mediated antiviral responses, and induce intermittent posttherapy viral load control in chronically SIVmac251-infected macaques. We here show that the macaques that had received this drug combination and then stopped antiretroviral therapy were also able to maintain low numbers of activated CD4(+) T cells at viral rebound. Moreover, these macaques consistently displayed low-level simian immunodeficiency virus (SIV) diversity, which was in line with the strong and broadly reactive cell-mediated immune responses against conserved Gag antigens. Extended follow-up showed that the two macaques that had received the complete drug combination remained healthy and did not develop AIDS in 2 years of follow-up after therapy suspension. This disease-free survival is longer than twice the average time of progression to AIDS in SIVmac251-infected rhesus macaques. These results suggest that limited numbers of activated T cells at viral rebound and subsequent development of broadly reactive cell-mediated responses may be interrelated in reducing the viral reservoir

    Azadirachta indica A. Juss. In Vivo Toxicity—An Updated Review

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    The Neem tree, Azadirachta indica A. Juss., is known for its large spectrum of compounds with biological and pharmacological interest. These include, among others, activities that are anticancer, antibacterial, antiviral, and anti-inflammatory. Some neem compounds are also used as insecticides, herbicides, and/or antifeedants. The safety of these compounds is not always taken into consideration and few in vivo toxicity studies have been performed. The current study is a literature review of the latest in vivo toxicity of A. indica. It is divided in two major sections—aquatic animals toxicity and mammalian toxicity—each related to neem’s application as a pesticide or a potential new therapeutic drug, respectively.info:eu-repo/semantics/publishedVersio

    The Polycomb repressive complex 2 deposits H3K27me3 and represses transposable elements in a broad range of eukaryotes

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    The mobility of transposable elements (TEs) contributes to evolution of genomes. Their uncontrolled activity causes genomic instability; therefore, expression of TEs is silenced by host genomes. TEs are marked with DNA and H3K9 methylation, which are associated with silencing in flowering plants, animals, and fungi. However, in distantly related groups of eukaryotes, TEs are marked by H3K27me3 deposited by the Polycomb repressive complex 2 (PRC2), an epigenetic mark associated with gene silencing in flowering plants and animals. The direct silencing of TEs by PRC2 has so far only been shown in one species of ciliates. To test if PRC2 silences TEs in a broader range of eukaryotes, we generated mutants with reduced PRC2 activity and analyzed the role of PRC2 in extant species along the lineage of Archaeplastida and in the diatom P. tricornutum. In this diatom and the red alga C. merolae, a greater proportion of TEs than genes were repressed by PRC2, whereas a greater proportion of genes than TEs were repressed by PRC2 in bryophytes. In flowering plants, TEs contained potential cis-elements recognized by transcription factors and associated with neighbor genes as transcriptional units repressed by PRC2. Thus, silencing of TEs by PRC2 is observed not only in Archaeplastida but also in diatoms and ciliates, suggesting that PRC2 deposited H3K27me3 to silence TEs in the last common ancestor of eukaryotes. We hypothesize that during the evolution of Archaeplastida, TE fragments marked with H3K27me3 were selected to shape transcriptional regulation, controlling networks of genes regulated by PRC2

    Frequently Identified Gaps in Antibiotic Stewardship Programs in Critical Access Hospitals

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    Background: Nebraska (NE) Infection Control Assessment and Promotion Program (ICAP) is a CDC funded project. ICAP team works in collaboration with NE Department of Health and Human Services (NEDHHS) to assess and improve infection prevention and control programs (IPCP) in various health care settings including resource limited settings like critical access hospitals (CAH). Little is known about the existing gaps in antimicrobial stewardship programs (ASP) of CAH. Hence, we decided to study the current level of ASP activities and factors associated with these activities in CAH. Methods: NE ICAP conducted on-site surveys in 36 CAH from October 2015 to February 2017. ASP activities related to the 7 CDC recommended core elements (CE) including leadership support (LS), accountability, drug expertise (DE), action, tracking, reporting, and education were assessed using a CDC Infection Control Assessment Tool for acute care hospitals. Descriptive analyses evaluated CAH characteristics and frequency of CE implementation. Fisher’s exact, Mann–Whitney, and Kruskal–Wallis tests were used for statistical analyses examining the association of various factors with level of ASP activities. Results: The 36 surveyed CAH had a median of 20 (range 10–25) beds and employed a median of 0.4 (range 0.1–1.6) infection preventionist (IP) full-time equivalent (FTE)/25-bed. Frequency of CE implementation varied among CAH with action and LS as the most (69%) and least (28%) frequently implemented elements, respectively. Close to half (47%) of surveyed CAH had implemented ≥4 CE but only 14% of facilities had all 7 CE. Median bed size and IP FTE/25-bed were similar among CAH with 0–2, 3-5, or ≥6 CE in place. CAH with LS or accountability for ASP implemented higher median numbers of the remaining CE compared with CAH without LS or accountability (5 vs. 2, P \u3c 0.01 and 4 vs. 2, P \u3c 0.01, respectively). Facilities with The presence of LS, accountability and drug expertise were more likely to have all 4 remaining CE implemented than others (56% vs. 8%, P \u3c 0.01). Conclusion: LS, accountability, and DE are important factors for the implementation of the remaining 4 CE in CAH. Although LS was the least frequently implemented CE, when present was associated with implementation of most of the other CE. Acquiring LS will facilitate implementation of additional ASP efforts in CAH.https://digitalcommons.unmc.edu/asap_pres/1000/thumbnail.jp

    Nuclear Receptor Interaction Protein (NRIP) expression assay using human tissue microarray and immunohistochemistry technology confirming nuclear localization

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    Background: A novel human nuclear receptor interaction protein (NRIP) has recently been discovered by Chen SL et al , which may play a role in enhancing the transcriptional activity of steroid nuclear receptors in prostate (LNCaP) and cervical (C33A) cancer cell lines. However, knowledge about the biological functions and clinical implications of NRIP, is still incomplete. Our aim was to determine the distribution of NRIP expression and to delineate the cell types that express NRIP in various malignant tumors and healthy non-pathological tissues. This information will significantly affect the exploration of its physiological roles in healthy and tumor cells. Methods: By using tissue microarray (TMA) technology and an anti-NRIP monoclonal antibody immunohistochemical (IHC) survey, NRIP expression was examined in 48 types of tumors and in a control group of 48 matched or unmatched healthy non-neoplastic tissues. Results: Our survey results showed that ten cases were revealed to express the NRIP in six malignancies (esophageal , colon, breast, ovarian, skin, and pancreatic cancers), but not all of these specific tumor types consistently showed positive NRIP expression. Moreover, malignant tumors of the stomach, prostate, liver, lung, kidney, uterine cervix, urinary bladder, lymph node, testis, and tongue revealed no NRIP expression. Among the control group of 48 matched and unmatched nonneoplastic tissues, all of them demonstrated IHC scores less than the cut-off threshold of 3. In addition , ten cores out of thirty-six carcinomatous tissues revealed positive NRIP expression, which indicated that NRIP expression increases significantly in carcinoma tissue cores , comparing to the matched controlled healthy tissues. Conclusion: This is the first study to use a human TMA and IHC to validate the nuclear localization for this newly identified NRIP expression. In considering the use of NRIP as a potential diagnostic tool for human malignancies survey , it is important to note that NRIP expression carries a sensitivity of only 23%, but has a specificity of 100%. There is also a significant difference in positive NRIP expression between primary carcinomatous tissues and matched controlled healthy tissues. Although further large-scale studies will merit to be conducted to evaluate its role as a potential adjunct for cancer diagnosis, data from this study provides valuable references for the future investigation of the biological functions of NRIP in humans
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