112 research outputs found

    DeepBrain: Functional Representation of Neural In-Situ Hybridization Images for Gene Ontology Classification Using Deep Convolutional Autoencoders

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    This paper presents a novel deep learning-based method for learning a functional representation of mammalian neural images. The method uses a deep convolutional denoising autoencoder (CDAE) for generating an invariant, compact representation of in situ hybridization (ISH) images. While most existing methods for bio-imaging analysis were not developed to handle images with highly complex anatomical structures, the results presented in this paper show that functional representation extracted by CDAE can help learn features of functional gene ontology categories for their classification in a highly accurate manner. Using this CDAE representation, our method outperforms the previous state-of-the-art classification rate, by improving the average AUC from 0.92 to 0.98, i.e., achieving 75% reduction in error. The method operates on input images that were downsampled significantly with respect to the original ones to make it computationally feasible

    Community engagement practices at research centers in U.S. minority institutions: Priority populations and innovative approaches to advancing health disparities research

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    This paper details U.S. Research Centers in Minority Institutions (RCMI) Community Engagement Cores (CECs): (1) unique and cross-cutting components, focus areas, specific aims, and target populations; and (2) approaches utilized to build or sustain trust towards community participation in research. A mixed-method data collection approach was employed for this cross-sectional study of current or previously funded RCMIs. A total of 18 of the 25 institutions spanning 13 U.S. states and territories participated. CEC specific aims were to support community engaged research (94%); to translate and disseminate research findings (88%); to develop partnerships (82%); and to build capacity around community research (71%). Four open-ended questions, qualitative analysis, and comparison of the categories led to the emergence of two supporting themes: (1) establishing trust between the community-academic collaborators and within the community and (2) building collaborative relationships. An overarching theme, building community together through trust and meaningful collaborations, emerged from the supporting themes and subthemes. The RCMI institutions and their CECs serve as models to circumvent the historical and current challenges to research in communities disproportionately affected by health disparities. Lessons learned from these cores may help other institutions who want to build community trust in and capacities for research that addresses community-related health concerns

    British Communists and the 1932 turn to the trade unions

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    The Comintern’s Third Period, 1928-1934, based on Stalin’s ‘second revolution’ in Russia, capitalist crisis and the claim that social democracy and fascism were twins, generated sectarian, ultra-left politics which proved inimical to Communist activity in trade unions. This article sheds new light on that issue by revisiting three connected episodes: the British party’s (CPGB) renewed turn to the unions, heralded in the January resolution of 1932; the roles Comintern staff and CPGB leader Harry Pollitt, played in this initiative; and the subsequent attempt by Pollitt to revise the politics of union work. This triptych reviews both primary sources and the recent historiography. It argues that some accounts have overestimated the novelty of the January resolution, blurred its meaning, and exaggerated Pollitt’s part in it. The resolution did not attempt to change the line but its application. Its impact was limited. Subsequent bids to go beyond it were muddled and unsuccessful. The 1933 move towards the united front, and the ensuing turn to the popular front, possessed more profound significance in the creation of an effective Communist presence in trade unions than the events of 1931- 1932

    A direct comparison of strategies for combinatorial RNA interference

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    <p>Abstract</p> <p>Background</p> <p>Combinatorial RNA interference (co-RNAi) is a valuable tool for highly effective gene suppression of single and multiple-genes targets, and can be used to prevent the escape of mutation-prone transcripts. There are currently three main approaches used to achieve co-RNAi in animal cells; multiple promoter/shRNA cassettes, long hairpin RNAs (lhRNA) and miRNA-embedded shRNAs, however, the relative effectiveness of each is not known. The current study directly compares the ability of each co-RNAi method to deliver pre-validated siRNA molecules to the same gene targets.</p> <p>Results</p> <p>Double-shRNA expression vectors were generated for each co-RNAi platform and their ability to suppress both single and double-gene reporter targets were compared. The most reliable and effective gene silencing was achieved from the multiple promoter/shRNA approach, as this method induced additive suppression of single-gene targets and equally effective knockdown of double-gene targets. Although both lhRNA and microRNA-embedded strategies provided efficient gene knockdown, suppression levels were inconsistent and activity varied greatly for different siRNAs tested. Furthermore, it appeared that not only the position of siRNAs within these multi-shRNA constructs impacted upon silencing activity, but also local properties of each individual molecule. In addition, it was also found that the insertion of up to five promoter/shRNA cassettes into a single construct did not negatively affect the efficacy of each individual shRNA.</p> <p>Conclusions</p> <p>By directly comparing the ability of shRNAs delivered from different co-RNA platforms to initiate knockdown of the same gene targets, we found that multiple U6/shRNA cassettes offered the most reliable and predictable suppression of both single and multiple-gene targets. These results highlight some important strengths and pitfalls of the currently used methods for multiple shRNA delivery, and provide valuable insights for the design and application of reliable co-RNAi.</p

    Reducing the health disparities of Indigenous Australians: time to change focus

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    Background: Indigenous peoples have worse health than non-Indigenous, are over-represented amongst the poor and disadvantaged, have lower life expectancies, and success in improving disparities is limited. To address this, research usually focuses on disadvantaged and marginalised groups, offering only partial understanding of influences underpinning slow progress. Critical analysis is also required of those with the power to perpetuate or improve health inequities. In this paper, using Australia as a case example, we explore the effects of ‘White’, Anglo-Australian cultural dominance in health service delivery to Indigenous Australians. We address the issue using race as an organising principle, underpinned by relations of power.Methods: Interviews with non-Indigenous medical practitioners in Western Australia with extensive experience in Indigenous health encouraged reflection and articulation of their insights into factors promoting or impeding quality health care to Indigenous Australians. Interviews were audio-taped and transcribed. An inductive, exploratory analysis identified key themes that were reviewed and interrogated in light of existing literature on health care to Indigenous people, race and disadvantage. The researchers’ past experience, knowledge and understanding of health care and Indigenous health assisted with data interpretation. Informal discussions were also held with colleagues working professionally in Indigenous policy, practice and community settings.Results: Racism emerged as a key issue, leading us to more deeply interrogate the role ‘Whiteness’ plays in Indigenous health care. While Whiteness can refer to skin colour, it also represents a racialized social structure where Indigenous knowledge, beliefs and values are subjugated to the dominant western biomedical model in policy and practice. Racism towards Indigenous patients in health services was institutional and interpersonal. Internalised racism was manifest when Indigenous patients incorporated racist attitudes and beliefs into their lived experience, lowering expectations and their sense of self-worth.Conclusions: Current health policies and practices favour standardised care where the voice of those who are marginalised is often absent. Examining the effectiveness of such models in reducing health disparities requires health providers to critically reflect on whether policies and practices promote or compromise Indigenous health and wellbeing - an important step in changing the discourse that places Indigenous people at the centre of the problem

    Selection of the silicon sensor thickness for the Phase-2 upgrade of the CMS Outer Tracker

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    During the operation of the CMS experiment at the High-Luminosity LHC the silicon sensors of the Phase-2 Outer Tracker will be exposed to radiation levels that could potentially deteriorate their performance. Previous studies had determined that planar float zone silicon with n-doped strips on a p-doped substrate was preferred over p-doped strips on an n-doped substrate. The last step in evaluating the optimal design for the mass production of about 200 m2^{2} of silicon sensors was to compare sensors of baseline thickness (about 300 μm) to thinned sensors (about 240 μm), which promised several benefits at high radiation levels because of the higher electric fields at the same bias voltage. This study provides a direct comparison of these two thicknesses in terms of sensor characteristics as well as charge collection and hit efficiency for fluences up to 1.5 × 1015^{15} neq_{eq}/cm2^{2}. The measurement results demonstrate that sensors with about 300 μm thickness will ensure excellent tracking performance even at the highest considered fluence levels expected for the Phase-2 Outer Tracker

    Test beam performance of a CBC3-based mini-module for the Phase-2 CMS Outer Tracker before and after neutron irradiation

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    The Large Hadron Collider (LHC) at CERN will undergo major upgrades to increase the instantaneous luminosity up to 5–7.5×1034^{34} cm2^{-2}s1^{-1}. This High Luminosity upgrade of the LHC (HL-LHC) will deliver a total of 3000–4000 fb-1 of proton-proton collisions at a center-of-mass energy of 13–14 TeV. To cope with these challenging environmental conditions, the strip tracker of the CMS experiment will be upgraded using modules with two closely-spaced silicon sensors to provide information to include tracking in the Level-1 trigger selection. This paper describes the performance, in a test beam experiment, of the first prototype module based on the final version of the CMS Binary Chip front-end ASIC before and after the module was irradiated with neutrons. Results demonstrate that the prototype module satisfies the requirements, providing efficient tracking information, after being irradiated with a total fluence comparable to the one expected through the lifetime of the experiment

    Comparative evaluation of analogue front-end designs for the CMS Inner Tracker at the High Luminosity LHC

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    The CMS Inner Tracker, made of silicon pixel modules, will be entirely replaced prior to the start of the High Luminosity LHC period. One of the crucial components of the new Inner Tracker system is the readout chip, being developed by the RD53 Collaboration, and in particular its analogue front-end, which receives the signal from the sensor and digitizes it. Three different analogue front-ends (Synchronous, Linear, and Differential) were designed and implemented in the RD53A demonstrator chip. A dedicated evaluation program was carried out to select the most suitable design to build a radiation tolerant pixel detector able to sustain high particle rates with high efficiency and a small fraction of spurious pixel hits. The test results showed that all three analogue front-ends presented strong points, but also limitations. The Differential front-end demonstrated very low noise, but the threshold tuning became problematic after irradiation. Moreover, a saturation in the preamplifier feedback loop affected the return of the signal to baseline and thus increased the dead time. The Synchronous front-end showed very good timing performance, but also higher noise. For the Linear front-end all of the parameters were within specification, although this design had the largest time walk. This limitation was addressed and mitigated in an improved design. The analysis of the advantages and disadvantages of the three front-ends in the context of the CMS Inner Tracker operation requirements led to the selection of the improved design Linear front-end for integration in the final CMS readout chip

    Beam test performance of a prototype module with Short Strip ASICs for the CMS HL-LHC tracker upgrade

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    The Short Strip ASIC (SSA) is one of the four front-end chips designed for the upgrade of the CMS Outer Tracker for the High Luminosity LHC. Together with the Macro-Pixel ASIC (MPA) it will instrument modules containing a strip and a macro-pixel sensor stacked on top of each other. The SSA provides both full readout of the strip hit information when triggered, and, together with the MPA, correlated clusters called stubs from the two sensors for use by the CMS Level-1 (L1) trigger system. Results from the first prototype module consisting of a sensor and two SSA chips are presented. The prototype module has been characterized at the Fermilab Test Beam Facility using a 120 GeV proton beam

    The CMS Phase-1 pixel detector upgrade

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    The CMS detector at the CERN LHC features a silicon pixel detector as its innermost subdetector. The original CMS pixel detector has been replaced with an upgraded pixel system (CMS Phase-1 pixel detector) in the extended year-end technical stop of the LHC in 2016/2017. The upgraded CMS pixel detector is designed to cope with the higher instantaneous luminosities that have been achieved by the LHC after the upgrades to the accelerator during the first long shutdown in 2013–2014. Compared to the original pixel detector, the upgraded detector has a better tracking performance and lower mass with four barrel layers and three endcap disks on each side to provide hit coverage up to an absolute value of pseudorapidity of 2.5. This paper describes the design and construction of the CMS Phase-1 pixel detector as well as its performance from commissioning to early operation in collision data-taking.Peer reviewe
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