Publications by authors named "Steven Becker"

Recurrent neural networks (RNNs) can process contextual information such as time series signals and language. But their tracking of internal states is a limiting factor, motivating research on analog implementations in photonics. While photonic unidirectional feedforward neural networks (NNs) have demonstrated big leaps, bi-directional optical RNNs present a challenge: the need for a short-term memory that (i) programmable and coherently computes optical inputs, (ii) minimizes added noise, and (iii) allows scalability.

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Article Synopsis
  • Eight years ago, a big project was started by the National Eye Institute to help people see better by fixing their eyes.
  • They have made good progress in replacing special cells in the eye called retinal neurons, but there are still some challenges to overcome.
  • By the end of this decade, they hope to start testing this eye treatment on people for the first time!
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Tetrabromo aromatics can be synthesized by the Fischer-Zimmermann condensation of appropriate pyrylium salts with arylene dicarboxylic acid salts. Their cyclization by intramolecular Yamamoto coupling yields strained bicyclophanes with adjustable sizes and different intraannular bridges. All compounds adsorb at the solid/liquid interface on highly oriented pyrolytic graphite (HOPG) and are investigated by scanning tunneling microscopy (STM) with submolecular resolution.

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This update will highlight a few of the projects funded by the National Eye Institute (NEI) Audacious Goals Initiative for Regenerative Medicine (AGI) and show their potential to advance regenerative medicine strategies and increase our understanding of the pathobiology of retinal disease. We summarize the recent updates from a talk given to the scientific community about the progress of various AGI-funded projects. NEI is catalyzing the translation of ocular stem cell therapies with its AGI program.

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Purpose: To review past and current National Eye Institute (NEI)-supported age-related macular degeneration (AMD) activities and initiatives and preview upcoming coordinated efforts for studying AMD.

Methods: We conducted and summarized a portfolio analysis and literature review of NEI intramural and extramural AMD activities.

Results: The NEI supports a broad range of AMD research, both by individual independent investigators as well as through networks and consortia.

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In this study, we describe efforts by the National Eye Institute (NEI) and National Center for Advancing Translational Science (NCATS) to catalyze advances in 3-dimensional (3-D) ocular organoid and microphysiological systems (MPS). We reviewed the recent literature regarding ocular organoids and tissue chips. Animal models, 2-dimensional cell culture models, and postmortem human tissue samples provide the vision research community with insights critical to understanding pathophysiology and therapeutic development.

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Across scientific disciplines, 3-D organoid culture systems offer platforms to integrate basic research findings with clinical care. The National Eye Institute mounted a $1.1 million 3-D Retina Organoid Challenge.

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Both chemotaxis and phagocytosis depend upon actin-driven cell protrusions and cell membrane remodeling. While chemoattractant receptors rely upon canonical G-protein signaling to activate downstream effectors, whether such signaling pathways affect phagocytosis is contentious. Here, we report that Gαi nucleotide exchange and signaling helps macrophages coordinate the recognition, capture, and engulfment of zymosan bioparticles.

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Background: The molecular mechanisms whereby hepatitis B virus (HBV) induces hepatocellular carcinoma (HCC) remain elusive. We used genomic and molecular techniques to investigate host-virus interactions by studying multiple areas of the same liver from patients with HCC.

Methods: We compared the gene signature of whole liver tissue (WLT) versus laser capture-microdissected (LCM) hepatocytes along with the intrahepatic expression of HBV.

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Tissue autofluorescence frequently hampers visualization of immunofluorescent markers in formalin-fixed paraffin-embedded respiratory tissues. We assessed nine treatments reported to have efficacy in reducing autofluorescence in other tissue types. The three most efficacious were Eriochrome black T, Sudan black B and sodium borohydride, as measured using white light laser confocal Λ (multi-lambda) analysis.

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Geneticists and breeders are positioned to breed plants with root traits that improve productivity under drought. However, a better understanding of root functional traits and how traits are related to whole plant strategies to increase crop productivity under different drought conditions is needed. Root traits associated with maintaining plant productivity under drought include small fine root diameters, long specific root length, and considerable root length density, especially at depths in soil with available water.

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In response to the March 2011 earthquake-tsunami disaster and the Fukushima Dai-ichi nuclear accident, a special nongovernmental Radiological Emergency Assistance Mission flew to Japan from the United States. Invited by one of Japan's largest hospital and healthcare groups and facilitated by a New York-based international disaster relief organization, the mission included an emergency physician, a health physicist, and a disaster management specialist. During the 10 d mission, team members conducted fieldwork in areas affected by the earthquake, tsunami, and nuclear accident; went to cities and towns in the 20-30 km Emergency Evacuation Preparation Zone around the damaged nuclear plant; visited other communities affected by the nuclear accident; went to evacuation shelters; met with mayors and other local officials; met with central government officials; exchanged observations, experiences, and information with Japanese medical, emergency response, and disaster management colleagues; and provided radiological information and training to more than 1,100 Japanese hospital and healthcare personnel and first responders.

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On March 11, 2011, the eastern portion of Japan was struck by a massive earthquake and tsunami that killed more than 15,700 people, left thousands of others hurt or missing, and caused widespread destruction. In addition, the Great East Japan Disaster seriously damaged the Fukushima Dai-ichi nuclear power station, knocking out power, severely affecting communications, and causing a loss of cooling to some reactor cores. Significant quantities of radioactive materials were released, a "no go" zone was created around the crippled reactors, and thousands of people were evacuated.

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It is now widely recognized that effective communication is a crucial element in radiological/nuclear terrorism preparedness. Whereas in the past, communication and information issues were sometimes viewed as secondary in comparison with technical concerns, today the need to improve risk communication, public information, and emergency messaging is seen as a high priority. The process of improving radiological/nuclear terrorism risk communication can be conceptualized as occurring in four overlapping phases.

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A nuclear detonation in a US city would have profound psychological, social, and behavioral effects. This article reviews the scientific literature on human responses to radiation incidents and disasters in general, and examines potential behavioral health care provider (BHCP) contributions in the hours and days after a nuclear detonation. In the area directly affected by the blast, the immediate overarching goal of BHCP interventions is the support of lifesaving activities and the prevention of additional casualties from fallout.

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Recently, widespread valley-bottom damming for water power was identified as a primary control on valley sedimentation in the mid-Atlantic US during the late seventeenth to early twentieth century. The timing of damming coincided with that of accelerated upland erosion during post-European settlement land-use change. In this paper, we examine the impact of local drops in base level on incision into historic reservoir sediment as thousands of ageing dams breach.

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The aim of the present study was to investigate the effect of exercise on angiogenesis during bone defect healing in mice. We evaluated angiogenesis during cranial bone defect healing by intravital fluorescence microscopy (IVM) at days 0-21. To characterize the type of bone repair, we performed additional histomorphometric analyses at days 3-15.

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The life cycle of Pneumocystis, which causes life-threatening pneumonia in immunosuppressed patients, remains poorly defined. In the present study, we have identified and characterized an orthologue of dmc1, a gene specific for meiotic recombination in yeast, in 3 species of Pneumocystis. dmc1 is a single-copy gene that is transcribed as ∼1.

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Background: Hepatitis C virus (HCV)-infected patients, including those co-infected with human immunodeficiency virus (HIV), are at increased risk of developing hepatocellular carcinoma (HCC). We evaluated the ability of agonistic human monoclonal antibodies to tumor necrosis factor-related apoptosis inducing ligand (TRAIL) receptors, mapatumumab and lexatumumab, respectively, to induce TRAIL-receptor mediated apoptosis (TRMA) in HCC (HCV-infected and -uninfected) cells and in peripheral blood cells (HIV-infected and -uninfected).

Methods: Susceptibility to antibody-mediated TRMA was measured by caspase 3/7 activity and by confocal microscopy.

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We have previously shown that vaccination with purified Entamoeba histolytica Gal/GalNAc lectin or recombinant subunits can protect mice from intestinal amebiasis upon intracecal challenge. In this study, we demonstrated with adoptive-transfer experiments that this lectin vaccine protection is mediated by T cells but not serum. The cell-mediated immune (CMI) response was characterized by significant gamma interferon (IFN-gamma), interleukin 12 (IL-12), IL-2, IL-10, and IL-17 production.

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September 11(th) events taught us, members of the medical community, that we need to prepared for the worst. Nuclear terror is no longer science fiction. Radiological weapons of mass terror come in three flavors: The first one is nuclear.

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Synaptotagmin VII (Syt VII) is a Ca(2+) sensing molecule that regulates lysosomal exocytosis in several cell types. In macrophages (MØ), Syt VII is required for efficient uptake of large particle loads, by promoting the delivery of lysosomal membrane to phagocytic cups. Here we compare the phagocytic capacity of bone marrow-derived MØs and dendritic cells (DC), and show that the requirement for Syt VII correlates with the unique ability of MØs for continuous phagocytosis.

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