569 research outputs found
Compressive sensing-based robust off-the-grid stretch processing
Classical stretch processing (SP) obtains high range resolution by compressing large bandwidth signals with narrowband receivers using lower rate analogue-to-digital converters. SP achieves the resolution of the large bandwidth signal by focusing into a limited range window, and by deramping in the analogue domain. SP offers moderate data rate for signal processing for high bandwidth waveforms. Furthermore, if the scene in the examined window is sparse, compressive sensing (CS)-based techniques have the potential to further decrease the required number of measurements. However, CS-based reconstructions are highly affected by model mismatches such as targets that are off-the-grid. This study proposes a sparsity-based iterative parameter perturbation technique for SP that is robust to targets off-the-grid in range or Doppler. The error between reconstructed and actual scenes is measured using Earth mover's distance metric. Performance analyses of the proposed technique are compared with classical CS and SP techniques in terms of data rate, resolution and signal-to-noise ratio. It is shown through simulations that the proposed technique offers robust and high-resolution reconstructions for the same data rate compared with both classical SP- and CS-based techniques. © 2017, The Institution of Engineering and Technology
3D printed Artificial Cornea for Corneal Stromal Transplantation
The aim of this study is to understand the optical, biocompatible, and mechanical properties of chitosan (CS) and polyvinyl-alcohol (PVA) based corneal stroma constructs using 3D printing process. Corneal stroma is tested for biocompatibility with human adipose tissue-derived mesenchymal stem cells (hASCs). Physico-chemical and chemical characterization of the construct was performed using scanning electron microscopy (SEM), fourier transforms infrared spectroscopy (FTIR). Optical transmittance was analyzed using UV-Spectrophotometer. Results showed fabricated constructs have required shape and size. SEM images showed construct has thickness of 400 µm. The FTIR spectra demonstrated the presence of various predicted peaks. The swelling and degradation studies of 13%(wt)PVA and 13%(wt)PVA/(1, 3, 5)%(wt)CS showed to have high swelling ratios of 7 days and degradation times of 30 days, respectively. The light transmittance values of the fabricated cornea constructs decreased with CS addition slightly. Tensile strength values decreased with increasing CS ratio, but we found to support intraocular pressure (IOP) which ranges from 12 to 22 mm-Hg. Preliminary biostability studies showed that composite constructs were compatible with hASCs even after 30 days’ of degradation, showing potential for these cells to be differentiated to stroma layer in future. This study has implications for the rapid and custom fabrication of various cornea constructs for clinical applications
Determining of Relationship Between Weed Seedbank in Soil and Weed Flora in Potato Areas
Bu çalışmada, Van Gölü ve Çevresi önemli patates ekiliş alanlarından Erciş ve Ahlat’ta topraktaki yabancı ot tohumlarının yoğunlukları, rastlanma sıklıkları ve bunların floraya yansıması araştırılmıştır. Erciş ve Ahlat patates ekiliş alanlarında 0-25 cm’lik toprak derinliğinde Amaranthus retroflexus L. ve Portulaca oleracea L. tohumlarının en yoğun türler olduğu saptanmıştır. Topraktaki tohum rezervinin floraya yansıma oranının Erciş’te sadece 2007 yılında %1.2; bunun dışında %1’den düşük olduğu belirlenmiştir.In this study it was investigated in order to determine density of weed seeds and reflection to flora at Ercis and Ahlat. The most common weed species were determined as to Amaranthus retroflexus L. and Portulaca oleracea L. in dept 0-25 cm of soil reservoir at Ercis and Ahlat fields. The ratio of reflection to flora of seed reservoirs in soil is determined lower than 1% as well. But this ratio in Ercis is found 1.2% in 2007
Ion source and LEBT of KAHVELab proton beamline
The KAHVE Laboratory, at Bo\u{g}azi\c{c}i University, Istanbul, Turkey is
home to an educational proton linac project. The proton beam will originate
from a 20 keV H+ source and will be delivered to a two module Radio Frequency
Quadrupole (RFQ) operating at 800 MHz via a low energy beam transport (LEBT)
line. Currently, the design phase being over, commissioning and stability tests
are ongoing for the proton beamline which is already produced and installed
except the RFQ which is being manufactured. This work summarizes the design,
production and test phases of the ion source and LEBT line components
Optimal Handling and Postharvest Strategies to Reduce Losses of ‘Cuello Dama Negro’ Dark Figs (Ficus Carica L.)
The optimal postharvest handling to reduce postharvest decay and maintain quality of ‘Cuello Dama Negro’ fresh dark figs grown in Spain is been studied. Different storage temperatures (0ºC and 4ºC), relative humidity (RH, 75% to 95%) and cooling strategies (delayed and intermittent cooling) were tested. Moreover, different postharvest strategies such as 1-MCP (10 ppm), two different passive modified atmosphere packaging (Xtend® and LifePack MAP), and SO2 generating pads (UVASYS, Grapetek (Pty) Ltd.), were also tested. Storage at 0ºC, 95% RH together with MAP effectively decreased postharvest rots and therefore increased the market life of ‘Cuello Dama Negro’ fresh figs, without altering the fruit quality nor the consumer liking degree. No improvement on the shelf life of the fruit was observed with the application of 1-MCP. The use of SO2 generating pads reduced the decay but detrimentally affected fruit quality by inducing skin bleaching. Low temperature from harvest to consumption is crucial for a good maintenance of quality in fresh fig. In addition, EMAP technology is a low-cost technology able to reduce decay and maintain fruit quality of fresh figs up to 2 weeks.info:eu-repo/semantics/acceptedVersio
Clinical heterogeneity can hamper the diagnosis of patients with ZAP70 deficiency
One of the severe combined immunodeficiencies (SCIDs), which is caused by a genetic defect in the signal transduction pathways involved in T-cell activation, is the ZAP70 deficiency. Mutations in ZAP70 lead to both abnormal thymic development and defective T-cell receptor (TCR) signaling of peripheral T-cells. In contrast to the lymphopenia in most SCID patients, ZAP70-deficient patients have lymphocytosis, despite the selective absence of CD8+ T-cells. The clinical presentation is usually before 2 years of age with typical findings of SCID. Here, we present three new ZAP70-deficient patients who vary in their clinical presentation. One of the ZAP70-deficient patients presented as a classical SCID, the second patient presented as a healthy looking wheezy infant, whereas the third patient came to clinical attention for the eczematous skin lesions simulating atopic dermatitis with eosinophilia and elevated immunoglobulin E (IgE), similar to the Omenn syndrome. This study illustrates that awareness of the clinical heterogeneity of ZAP70 deficiency is of utmost importance for making a fast and accurate diagnosis, which will contribute to the improvement of the adequate treatment of this severe immunodeficiency
Improved chromosome-level genome assembly of the Glanville fritillary butterfly (Melitaea cinxia) integrating Pacific Biosciences long reads and a high-density linkage map
Background The Glanville fritillary (Melitaea cinxia) butterfly is a model system for metapopulation dynamics research in fragmented landscapes. Here, we provide a chromosome-level assembly of the butterfly's genome produced from Pacific Biosciences sequencing of a pool of males, combined with a linkage map from population crosses. Results The final assembly size of 484 Mb is an increase of 94 Mb on the previously published genome. Estimation of the completeness of the genome with BUSCO indicates that the genome contains 92-94% of the BUSCO genes in complete and single copies. We predicted 14,810 genes using the MAKER pipeline and manually curated 1,232 of these gene models. Conclusions The genome and its annotated gene models are a valuable resource for future comparative genomics, molecular biology, transcriptome, and genetics studies on this species.Peer reviewe
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