63 research outputs found

    MATA-Cloud: A Cloud Detection and Dynamic Attitude Correction Evaluation Software

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    With the increasing demand for high-resolution images from earth observation satellites, there is a need to optimize the usability of the images being downloaded in the ground stations. Most captured satellite images are not usable for certain applications due to high cloud cover percentage. To address this problem, this research demonstrates a cloud detection and dynamic attitude correction evaluation software. This software explores two key experiments. First is evaluating different image processing and machine learning-based approaches to detect cloud cover. The cloud detection algorithms were evaluated based on their accuracy, latency, and memory consumption. The second is exploring dynamic attitude correction to minimize the effect of cloud cover on captured images. Results show that our software can help test algorithms that increase the usability of captured images

    Growing the Local Space Workforce Through Synergistic Collaborations of the Philippine Space Agency, Universities, and Private Industry

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    For decades, space technology and applications development have been in the forefront of human advancement. To maximize the gains from these achievements, numerous countries have established space agencies to manage the growing space economy. However, for emerging space countries, the establishment of a space agency and a complementary space ecosystem proves to be a more complex and challenging task. In this paper, we present a review of lessons learned in building up the local upstream space workforce in the Philippines through various projects spearheaded by the government, mostly through the Philippine Space Agency (PhilSA). For the projects in collaboration with universities, this paper discusses the importance of providing training programs, scholarship opportunities, research and development activities, and promotion of current Space Science and Technology capabilities to create a young pool of knowledgeable personnel. On the other hand, collaborations with the local industry provide a support to ongoing satellite development activities in PhilSA. Established companies specializing in space-adjacent activities such as those in the manufacturing, electronics, and software development have immense potential in transitioning to actual space development activities. The paper highlights the lessons learned from PhilSA\u27s ongoing collaborations with these companies, and how such engagements translate to a more skilled space workforce. This paper summarizes the challenges faced, milestones achieved, and how the lessons learned are applied to the current activities in PhilSA and form strategic plans. These lessons learned can be helpful to other emerging space nations looking to ramp up capacity building and establish a thriving space ecosystem

    MetalionRNA: computational predictor of metal-binding sites in RNA structures

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    Motivation: Metal ions are essential for the folding of RNA molecules into stable tertiary structures and are often involved in the catalytic activity of ribozymes. However, the positions of metal ions in RNA 3D structures are difficult to determine experimentally. This motivated us to develop a computational predictor of metal ion sites for RNA structures

    It’s all in the crystals…

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    Protein surface engineering is increasingly used as a routine tool to enhance the crystallization propensity of proteins. Future possibilities include the use of multi-site protein variants, rational modulation of solubility and the development of strategies to tackle membrane proteins

    Crystallographic and Biochemical Analysis of the Ran-Binding Zinc Finger Domain

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    The nuclear pore complex (NPC) resides in circular openings within the nuclear envelope and serves as the sole conduit to facilitate nucleocytoplasmic transport in eukaryotes. The asymmetric distribution of the small G protein Ran across the nuclear envelope regulates directionality of protein transport. Ran interacts with the NPC of metazoa via two asymmetrically localized components, Nup153 at the nuclear face and Nup358 at the cytoplasmic face. Both nucleoporins contain a stretch of distinct, Ran-binding zinc finger domains. Here, we present six crystal structures of Nup153-zinc fingers in complex with Ran and a 1.48 Å crystal structure of RanGDP. Crystal engineering allowed us to obtain well diffracting crystals so that all ZnF–Ran complex structures are refined to high resolution. Each of the four zinc finger modules of Nup153 binds one Ran molecule in apparently non-allosteric fashion. The affinity is measurably higher for RanGDP than for RanGTP and varies modestly between the individual zinc fingers. By microcalorimetric and mutational analysis, we determined that one specific hydrogen bond accounts for most of the differences in the binding affinity of individual zinc fingers. Genomic analysis reveals that only in animals do NPCs contain Ran-binding zinc fingers. We speculate that these organisms evolved a mechanism to maintain a high local concentration of Ran at the vicinity of the NPC, using this zinc finger domain as a sink

    Using Multiple Microenvironments to Find Similar Ligand-Binding Sites: Application to Kinase Inhibitor Binding

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    The recognition of cryptic small-molecular binding sites in protein structures is important for understanding off-target side effects and for recognizing potential new indications for existing drugs. Current methods focus on the geometry and detailed chemical interactions within putative binding pockets, but may not recognize distant similarities where dynamics or modified interactions allow one ligand to bind apparently divergent binding pockets. In this paper, we introduce an algorithm that seeks similar microenvironments within two binding sites, and assesses overall binding site similarity by the presence of multiple shared microenvironments. The method has relatively weak geometric requirements (to allow for conformational change or dynamics in both the ligand and the pocket) and uses multiple biophysical and biochemical measures to characterize the microenvironments (to allow for diverse modes of ligand binding). We term the algorithm PocketFEATURE, since it focuses on pockets using the FEATURE system for characterizing microenvironments. We validate PocketFEATURE first by showing that it can better discriminate sites that bind similar ligands from those that do not, and by showing that we can recognize FAD-binding sites on a proteome scale with Area Under the Curve (AUC) of 92%. We then apply PocketFEATURE to evolutionarily distant kinases, for which the method recognizes several proven distant relationships, and predicts unexpected shared ligand binding. Using experimental data from ChEMBL and Ambit, we show that at high significance level, 40 kinase pairs are predicted to share ligands. Some of these pairs offer new opportunities for inhibiting two proteins in a single pathway

    Structural signatures of antibiotic binding sites on the ribosome

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    The ribosome represents a major target for antibacterial drugs. Being a complex molecular machine, it offers many potential sites for functional interference. The high-resolution structures of ribosome in complex with various antibiotics provide a unique data set for understanding the universal features of drug-binding pockets on the ribosome. In this work, we have analyzed the structural and evolutionary properties of 65 antibiotic binding sites (ABSs) in the ribosome. We compared these sites to similar-size computed pockets extracted from the small and large ribosomal subunits. Based on this analysis, we defined properties of the known drug-binding sites, which constitute the signature of a ‘druggable’ site. The most noticeable properties of the ABSs are prevalence of non-paired bases, a strong bias in favor of unusual syn conformation of the RNA bases and an unusual sugar pucker. We propose that despite the different geometric and chemical properties of diverse antibiotics, their binding sites tend to have common attributes that possibly reflect the potency of the pocket for binding small molecules. Finally, we utilized the ensemble of properties to derive a druggability index, which can be used in conjunction with site functionality information to identify new drug-binding sites on the ribosome
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