Focusing and imaging with increased numerical apertures through multimode fibers with micro-fabricated optics

The use of individual multimode optical fibers in endoscopy applications has the potential to provide highly miniaturized and noninvasive probes for microscopy and optical micromanipulation. A few different strategies have been proposed recently, but they all suffer from intrinsically low resolution related to the low numerical aperture of multimode fibers. Here, we show that two-photon polymerization allows for direct fabrication of micro-optics components on the fiber end, resulting in an increase of the numerical aperture to a value that is close to 1. Coupling light into the fiber through a spatial light modulator, we were able to optically scan a submicrometer spot (300 nm FWHM) over an extended region, facing the opposite fiber end. Fluorescence imaging with improved resolution is also demonstrated.Comment: 5 pages, 3 figure

Encapsulation Of Ag Nanoparticle-Carbon Composite And Enhancement Of Visible Light ZnO Nanorods Photodiode

In this paper, the effect of encapsulating silver nanoparticles (Ag NPs)- carbon composite onto zinc oxide (ZnO) nanorods (NRs) hydrothermally grown on silicon substrate is characterized and its photodiode performance studied. The composite was dissolved in acetone and drop casted onto ZnO NRs and the samples are baked on a hot plate. FESEM imaging was done and shows the top part of ZnO NRs coated with the composite and EDX testing shows the component are made of carbon as the majority and Ag the minority component. Transmission electron microscopy (TEM) shows the Ag-NPs embedded into the carbon coating. Photoluminescence (PL) spectra shows slight peak broadening of the ZnO main peak at 378 nm. Photodiode measurements shows the encapsulated nanorods has reduced photoresponse to UV light (395 nm) but more responsive to visible light (460 nm) due to creation of new energy states inside the band gap of ZnO

Understanding the design-space of sparse/dense multiphase GNN dataflows on spatial accelerators

Graph Neural Networks (GNNs) have garnered a lot of recent interest because of their success in learning representations from graph-structured data across several critical applications in cloud and HPC. Owing to their unique compute and memory characteristics that come from an interplay between dense and sparse phases of computations, the emergence of recon-figurable dataflow (aka spatial) accelerators offers promise for acceleration by mapping optimized dataflows (i.e., computation order and parallelism) for both phases. The goal of this work is to characterize and understand the design-space of dataflow choices for running GNNs on spatial accelerators in order for mappers or design-space exploration tools to optimize the dataflow based on the workload. Specifically, we propose a taxonomy to describe all possible choices for mapping the dense and sparse phases of GNN inference, spatially and temporally over a spatial accelerator, capturing both the intra-phase dataflow and the inter-phase (pipelined) dataflow. Using this taxonomy, we do deep-dives into the cost and benefits of several dataflows and perform case studies on implications of hardware parameters for dataflows and value of flexibility to support pipelined execution.Parts of this work were supported through a fellowship by NEC Laboratories Europe, Project grant PID2020-112827GB-I00 funded by MCIN/AEI/ 10.13039/501100011033, RTI2018-098156-B-C53 (MCIU/AEI/FEDER,UE) and grant 20749/FPI/18 from Fundación Séneca.Peer ReviewedPostprint (author's final draft

Community Preventive Health Education Intervention for Pediatric Iron-Deficiency Anemia in Rural Southeast Nigeria

Objectives: Iron-deficiency anemia (IDA) is a global cause of morbidity in children under five, particularly in sub-Saharan Africa. In southeast Nigeria, poor dietary intake and caregiver knowledge about childhood anemia are observed; however, there is no consensus on how to best prevent it. This study seeks to test the effectiveness of caregiver education on improving anemia knowledge and dietary prevention strategies and promoting sustainable lifestyle changes to reduce the prevalence of childhood IDA. Study Design: A questionnaire was administered to the primary caregivers of 41 patients under age five with anemia in southeast Nigeria regarding socioeconomic status (SES), diet diversity, and risk factors for anemia. Caregivers were administered a preeducation questionnaire, poster education on anemia and iron-rich foods, and a posteducation questionnaire. All patients underwent a medical exam to confirm a diagnosis of anemia or anemia-related conditions. Results: Ninety-five percent of patients had moderate diet diversity, but there was no correlation between diet diversity and SES. Barriers to healthier diets were associated with SES. Preeducation scores were not associated with caregivers’ education levels; however, posteducation scores were significantly higher in university-educated than technical-trained caregivers. Caregiver-reported self-efficacy increased after the education program. Conclusion: Caregivers’ SES was associated with financial and knowledge barriers to a healthier diet but not diet diversity, suggesting that nutritional education could benefit all SES groups. Overall, the education program increased caregivers’ anemia knowledge across educational levels. A community-based health education program could improve caregivers’ anemia knowledge and self-efficacy in applying this information and potentially reduce this area’s pediatric IDA

IL-4–, TGF-β–, and IL-1–Dependent Expansion of Parasite Antigen-Specific Th9 Cells Is Associated with Clinical Pathology in Human Lymphatic Filariasis

Th9 cells are a subset of CD4(+) T cells, shown to be important in allergy, autoimmunity and anti-tumor responses. However, their role in human infectious diseases has not been explored in detail. We identified a population of IL-9 and IL-10 co-expressing cells (lacking IL-4 expression) in normal individuals that respond to antigenic and mitogenic stimulation but are distinct from IL-9(+) Th2 cells. We also demonstrate that these Th9 cells exhibit antigen –specific expansion in a chronic helminth infection (lymphatic filariasis). Comparison of Th9 responses reveals that individuals with pathology associated with filarial infection exhibit significantly expanded frequencies of filarial antigen induced Th9 cells but not of IL9(+)Th2 cells in comparison to filarial-infected individuals without associated disease. Moreover, the per cell production of IL-9 is significantly higher in Th9 cells compared to IL9(+)Th2 cells, indicating that the Th9 cells are the predominant CD4(+) T cell subset producing IL-9 in the context of human infection. This expansion was reflected in elevated antigen stimulated IL-9 cytokine levels in whole blood culture supernatants. Finally, the frequencies of Th9 cells correlated positively with the severity of lymphedema (and presumed inflammation) in filarial diseased individuals. This expansion of Th9 cells was dependent on IL-4, TGFβ and IL-1 in vitro. We have therefore a identified an important human CD4(+) T cell subpopulation co – expressing IL-9 and IL-10 but not IL-4 that is whose expansion is associated with disease in chronic lymphatic filariasis and could potentially play an important role in the pathogenesis of other inflammatory disorders