BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Structural and Functional Characterization of Novel Carbohydrate D eacetylase from Bacteroides DTSTART;VALUE=DATE-TIME:20260609T173000Z DTEND;VALUE=DATE-TIME:20260609T181500Z DTSTAMP;VALUE=DATE-TIME:20260606T093610Z UID:indico-contribution-814-10367@events.saip.org.za DESCRIPTION:Speakers: Krystle McLaughlin (Vassar College)\nOther authors: Lilith A. Schwartz1\, Jordan O. Norman1\, Sharika Hasan1\, Olive E. Adamek 1\, Elisa Dzuong1\, Jasmine C. Lowenstein1\, Olivia G. Yost1\, Banumathi S ankaran2\, \n1 Department of Chemistry\, Vassar College\, 124 Raymond Ave\ , Poughkeepsie\, NY\, 12604\n2 Advanced Light Source\, Lawrence Berkeley N ational Lab\, Berkeley CA\n\n\n\nBacteroides ovatus\, a commonly identifie d Bacteroides species in the human gut\, has been shown to have beneficial effects like the suppression of intestinal inflammation. However\, increa sed populations of B. ovatus also correlate with several autoimmune diseas e states\, such as Systemic Lupus Erythematosus (SLE). Many host-microbe i nteractions depend on bacterial cell surface carbohydrates\, including cap sular polysaccharides (CPS). CPS from related B. fragilis has known immuno modulatory effects. While their significance is understood\, CPS biosynthe sis has not been well studied. In this talk\, we present structural charac terization of a polysaccharide deacetylase from Bacteroides ovatus (BoPDA) thought to be involved in CPS biosynthesis. High resolution crystal struc tures reveal an unusual metal binding strategy for the CE4 family and an a typical\, non-modular domain architecture. Carbohydrate binding assays and deacetylase activity assays were used to investigate the function of the enzyme. BoPDA is the first protein CPS biosynthetic enzyme from B. ovatus to be characterized\, so this work helps further our understanding of this essential bacterial process.\n\nhttps://events.saip.org.za/event/274/cont ributions/10367/ LOCATION: URL:https://events.saip.org.za/event/274/contributions/10367/ END:VEVENT BEGIN:VEVENT SUMMARY:Recombinant Production and Biophysical Characterization Towards St ructural Determination of Aspergillus niger RING finger domain DTSTART;VALUE=DATE-TIME:20260608T173000Z DTEND;VALUE=DATE-TIME:20260608T180000Z DTSTAMP;VALUE=DATE-TIME:20260606T093610Z UID:indico-contribution-814-10354@events.saip.org.za DESCRIPTION:Speakers: Mary George (University of Johannesburg)\nThe most w idely diagnosed disease globally is cancer\, and it has been increasing in incidence and prevalence. The Global Cancer Observatory revealed that in 2022\, the number of new cases stood at 20 million\, and is set to increas e by 77.5 % by 2050. The pro-cancer Retinoblastoma binding protein 6 (RBBP 6) is a multi-domain protein that contains the Really Interesting New Gene (RING) domain\, which varies across species. Previous multiple sequence a lignment studies revealed that the RING domain of the mould Aspergillus ni ger differs from its human homolog due to the substitution of a cysteine f or an aspartic acid. In this study\, the A. niger RING domain was successf ully expressed in BL21 (DE3) E. coli cells and purified by immobilized-met al affinity and anion-exchange chromatography. The purified protein was ch aracterized using circular dichroism\, standard 1D-1H NMR\, 1D HET-SOFAST\ , 1D DOSY\, thermal denaturation\, thermal shift assays\, size-exclusion c hromatography with multi-angle light scattering\, and differential light s cattering. The protein was subsequently set up for crystallization trials. The secondary structural elements of the protein were elucidated by CD\, which showed that the protein consisted mostly of β-sheets. 1D NMR reveal ed that the protein was well-folded and well-structured\, with no disorder ed regions. Thermal denaturation showed the protein's thermal stability\, with a Tm of 52°C. SEC-MALS and DLS indicated that the protein is monomer ic\, with a molecular weight of approximately 9.9 kDa. Crystallization tri als yielded crystals under well conditions at 25°C in sodium fluoride\, B is-tris propane\, and PEG3350. These conditions were optimized and tested on the ID30A/ MASSIF 1 ESRF beamline\, but the protein did not diffract. T his study provides a foundation for the structural determination of the A. niger RING domain\, with the aim of designing and developing novel antica ncer therapeutics.\n\nhttps://events.saip.org.za/event/274/contributions/1 0354/ LOCATION: URL:https://events.saip.org.za/event/274/contributions/10354/ END:VEVENT BEGIN:VEVENT SUMMARY:Macromolecular X-ray Crystallography Studies of S. mansoni GAPDH i n the Discovery and Design of Novel Anti-Schistosomal Compounds DTSTART;VALUE=DATE-TIME:20260608T170000Z DTEND;VALUE=DATE-TIME:20260608T173000Z DTSTAMP;VALUE=DATE-TIME:20260606T093610Z UID:indico-contribution-814-10353@events.saip.org.za DESCRIPTION:Speakers: Naledi Pilusa (University of johannesburg)\nMacromol ecular X-ray crystallography is a powerful\, sensitive technique that allo ws the identification of ligand-protein complexes\, but it depends on crys tals of high resolution and high tolerance to inorganic solvents. In this study\, we investigated possible alternatives to the sole treatment of sch istosomiasis\, Praziquantel\, by identifying small molecules that can inte ract with *Schistosoma* *mansoni* Glyceraldehyde-3-phosphate dehydrogenase (SmGAPDH). Identified in all life stages of parasitic worms causing schis tosomiasis\, a chronic parasitic disease of poverty that causes significan t morbidity and mortality\, accounting for 70 million disability-adjusted life years lost annually. SmGAPDH is characterised as a potential therapeu tic target that plays a pivotal role in the parasite’s evasion of the hu man host and correlates with drug resistance. For this part of the study\, full-length SmGAPDH was produced in Escherichia coli cells\, purified to homogeneity using immobilised-nickel affinity chromatography and size-excl usion chromatography\, and subjected to crystallisation trials. X-ray diff raction data were collected and used to analyse the electron density map\, conduct structural analysis and functional studies\, and run fragment scr eening. The full-length SmGAPDH was successfully purified and formed cryst als within 24 hours under Morpheus and ShotGun1 screening\, yielding high- resolution X-ray diffraction data at 1.8 Å and reproducible 2.5 Å data i n the presence of DMSO. Evaluation of the electron density map shows a den sity for NAD+\, unobserved in the previous studies. A life soak test ident ified 12 binding pockets and 5 potential ligands. These findings provide a fundamental structural basis for applying crystallographic screening to d etermine the functional aspects of SmGAPDH exploitable in fragment-based d rug discovery and design\, while prioritising the NAD-binding site.\n\nhtt ps://events.saip.org.za/event/274/contributions/10353/ LOCATION: URL:https://events.saip.org.za/event/274/contributions/10353/ END:VEVENT BEGIN:VEVENT SUMMARY:Cross-Dataset EEG Workload Decoding Using Riemannian Deep Learning and Self-Supervised Representation Learning DTSTART;VALUE=DATE-TIME:20260609T193000Z DTEND;VALUE=DATE-TIME:20260609T195000Z DTSTAMP;VALUE=DATE-TIME:20260606T093610Z UID:indico-contribution-814-10361@events.saip.org.za DESCRIPTION:Speakers: Chitaranjan Mahapatra (Institute for Basic Science ( IBS)\,Daejeon 34126\, South Korea)\nReliable decoding of cognitive workloa d from electroencephalography (EEG) signals is essential for adaptive robo tics\, neuroergonomics\, intelligent transportation\, and human–machine interaction systems. Despite recent advances in deep learning\, EEG-based workload classification remains limited by poor cross-subject and cross-da taset generalization. In this work\, we investigate hybrid Riemannian deep learning and self-supervised representation learning frameworks for robus t EEG workload estimation across heterogeneous datasets. We developed a co mprehensive benchmark pipeline integrating classical signal processing\, c ovariance-based Riemannian geometry\, transformer models\, self-supervised contrastive learning\, and explainable artificial intelligence. Experimen ts were performed using the publicly available ds007262 arithmetic EEG wor kload dataset and the STEW simultaneous task EEG workload dataset. Six dec oding frameworks were evaluated: FBCSP\, EEGNet\, Riemannian tangent-space classifiers\, transformer networks\, self-supervised learning architectur es\, and a proposed hybrid Riemannian deep learning model. Subject-indepen dent evaluation using leave-one-subject-out cross-validation demonstrated that hybrid covariance-aware models consistently outperformed conventional CNN pipelines. The proposed hybrid framework achieved approximately 61% m ean classification accuracy\, while transformer and self-supervised learni ng models demonstrated improved temporal representation learning capabilit ies. Statistical benchmarking using ROC curves\, precision–recall curves \, violin plots\, and Wilcoxon significance testing confirmed the superior ity of hybrid geometric learning approaches. Explainable AI analyses revea led neurophysiologically meaningful workload-related EEG patterns involvin g frontal theta enhancement and parietal alpha suppression. Channel import ance mapping demonstrated dominant contributions from frontal and parietal cortical regions associated with attentional control and working memory p rocesses. To evaluate robustness and transferability\, cross-dataset exper iments were performed by training on ds007262 and testing on STEW. Results demonstrated substantial performance degradation caused by domain shift\, recording variability\, and montage mismatch across datasets. These findi ngs highlight the major challenge of EEG transferability in real-world app lications and emphasize the need for future domain adaptation and transfer learning strategies. The proposed benchmark framework provides a reproduc ible pipeline for evaluating EEG workload decoding algorithms under both s ubject-independent and cross-dataset settings. The integration of Riemanni an geometry\, explainable AI\, and self-supervised learning offers a promi sing direction for robust cognitive monitoring systems in intelligent robo tics and adaptive neurotechnology applications.\n\nhttps://events.saip.org .za/event/274/contributions/10361/ LOCATION: URL:https://events.saip.org.za/event/274/contributions/10361/ END:VEVENT BEGIN:VEVENT SUMMARY:Electrical Activity of Aluminum-\, Boron-\, and n-Type Impurity– Defect Complexes in Germanium: Implications for Enhanced Ge-Based Devices DTSTART;VALUE=DATE-TIME:20260609T191000Z DTEND;VALUE=DATE-TIME:20260609T193000Z DTSTAMP;VALUE=DATE-TIME:20260606T093610Z UID:indico-contribution-814-10359@events.saip.org.za DESCRIPTION:Speakers: Emmanuel Igumbor (University of Johannesburg)\nStudi es on point defects in germanium (Ge) are increasing\, primarily because t hese defects have the potential to modify the electronic and optical prope rties of Ge\, thereby enhancing device applications. While significant pro gress has been made in defect studies\, a comprehensive understanding of d efect complexes resulting from interactions between type (Al or B) and p-t ype atoms (D_GeX_i and DX\; where D = Al\, B\, and X = N\, P\, As\, Sb) is still lacking. Therefore density functional theory calculations of electr ically active defect levels in Ge that are caused by interactions between n-type impurity atoms and Al or B\, are presented. For defect-complexes fo rmed by Al and n-type atoms\, Al and P exhibit the highest formation stabi lity under equilibrium conditions. Conversely\, B_GeP_i represents the mos t energetically favorable defect-complex. With the exception of B_GeN_i\, the energetic stability of all defect-complexes suggests that Al and B int erstitials form strong bonds with n-type substitutional atoms. Electrical behavior analyses of these defects reveal that defect-complexes formed by Al and n-type atoms induce deep defect levels. Specifically\, Al_GeN_i act s as an acceptor\, while Al_iAs_Ge behaves as a donor. The defects B_GeSb_ i\, B_iP_Ge\, and B_iAs_Ge donate electrons to the conduction band at ener gy levels within the range of 3 KbT. Furthermore\, B_GeSb_i induces shallo w donor levels\, whereas B_GeP_i induces acceptor levels. This study opens new research opportunities in the experimental synthesis of defects and o ffers insights into controlling them\, potentially enhancing electronic de vices.\n\nhttps://events.saip.org.za/event/274/contributions/10359/ LOCATION: URL:https://events.saip.org.za/event/274/contributions/10359/ END:VEVENT BEGIN:VEVENT SUMMARY:Rectangular Cuboid Metamaterial Emitter at High Temperatures with Enhanced Spectral Efficiency for Low-Bandgap Energy Conversion. DTSTART;VALUE=DATE-TIME:20260609T185000Z DTEND;VALUE=DATE-TIME:20260609T191000Z DTSTAMP;VALUE=DATE-TIME:20260606T093610Z UID:indico-contribution-814-10358@events.saip.org.za DESCRIPTION:Speakers: Tesfaye Hurrisa (Adama science and Technology univer sity)\nEnergy concerns are among the main obstacles to maintaining the via bility of our planet and modern life\, as fossil fuels non-renewable energ y resources remain the primary source of global energy consumption. This s tudy presents a theoretical investigation into the spectral performance of a metamaterial structure composed of tungsten (W) and hafnium dioxide (Hf O₂) layers\, specifically designed using the Finite Element Method (FEM) for energy conversion applications. The properties of materials were stud ied using DFT with Quantum ESPRESSO and the Materials Project\, and were t aken from databases. The proposed structure is a broadband\, wide-angle\, and polarization-independent rectangular cuboid metamaterial (MDM) emitter intended for power generation systems\, falling under the category of ren ewable energy technologies. The designed emitter is configured in a three- layer arrangement to enhance light absorption and emission characteristics at specific wavelengths\, with a cut-off wavelength of 2.3 μm for an InG aAsSb photovoltaic cell operating at high temperatures. To achieve the des ired broadband emission\, various geometric parameters were optimized\, in cluding the cuboid’s height and length\, the dielectric layer thickness\ , and the unit cell width. Meanwhile\, the width and height of the ground plane\, along with the cuboid's distance from the center\, were kept const ant. Numerical simulations demonstrated a mean emittance of 94% in the wav elength range of 0.3–2.3 μm. Compared to other designs\, the proposed e mitter exhibits higher spectral efficiency under high-temperature conditio ns. Notably\, at 1600 K\, the rectangular cuboid emitter achieved a spectr al efficiency of 90% with an InGaAsSb bandgap of 0.53 eV. Thus\, the prima ry advantages of this study over previous ones include high spectral effic iency at specific bandgaps (indicating high conversion efficiency)\, cost- effectiveness\, ease of large-scale production\, reduced greenhouse gas em issions\, and long-term durability under high temperatures.\nKeywords: Sel ective Emitter\, Energy\, Thermo-photovoltaic\, Metamaterial\n\nhttps://ev ents.saip.org.za/event/274/contributions/10358/ LOCATION: URL:https://events.saip.org.za/event/274/contributions/10358/ END:VEVENT BEGIN:VEVENT SUMMARY:Phototransferred Thermoluminescence Properties of CaGa2O4:Pr3+ Pre pared by Solution Combustion Method\, Analytical methods and applications. DTSTART;VALUE=DATE-TIME:20260609T183000Z DTEND;VALUE=DATE-TIME:20260609T185000Z DTSTAMP;VALUE=DATE-TIME:20260606T093610Z UID:indico-contribution-814-10357@events.saip.org.za DESCRIPTION:Speakers: Clement Sichangi (University of South Africa)\nPhoto transferred thermoluminescence (PTTL) is the transfer of optically stimula ted electrons from deep saturated electron traps to previously emptied sha llow electron traps. Conventional thermoluminescence (TL) of CaGa2O4:Pr3+ shows five peaks of which only three are Phototransferred under illuminati on by blue light (470nm) for TL measured to 500 oC. Pulse annealing analys is shows all PTTL peaks as acceptors of electrons from their successful tr aps. Analysis of very deep traps reveals only two peaks are acceptors to t raps beyond 500oC\, one of which is not observed for preheating below this temperature suggesting competition from other traps. No PTTL peak observe d for preheating beyond 630 oC suggesting absence of deep traps beyond thi s temperature. The effect of illumination time is analyzed for each PTTL p eak. Control studies without illumination shows no peak reappearance after it is cleared by preheating. These great properties are good for home lig hting\, dosimetry and light in the dark materials.\n\nhttps://events.saip. org.za/event/274/contributions/10357/ LOCATION: URL:https://events.saip.org.za/event/274/contributions/10357/ END:VEVENT BEGIN:VEVENT SUMMARY:NSF-PREM Student to Synchrotron User: A Scientific Journey Through CHESS DTSTART;VALUE=DATE-TIME:20260608T153000Z DTEND;VALUE=DATE-TIME:20260608T160000Z DTSTAMP;VALUE=DATE-TIME:20260606T093610Z UID:indico-contribution-814-10362@events.saip.org.za DESCRIPTION:Speakers: Brenda Lee Vargas Pérez (University of Puerto Rico\ , Río Piedras Campus)\nAccess to synchrotron facilities provides unique o pportunities for the scientific and professional development of early-care er researchers\, especially those from underrepresented regions such as Pu erto Rico. This presentation highlights my trajectory as a graduate studen t whose scientific path has been enriched through long-term involvement wi th the Cornell High Energy Synchrotron Source (CHESS). Beginning in 2019 w ith a three-month internship during a major synchrotron upgrade\, the expe rience provided direct exposure to operating a large-scale research facili ty\, including technical and mechanical work. Later\, a second visit to CH ESS allowed exploration of the scientific and experimental side of synchro tron research\, leading to participation as a user of the facility. During a PREM-supported master’s project at Universidad Ana G. Méndez\, conti nued involvement in synchrotron research strengthened an interest in energ y materials and in scientific collaboration opportunities. This subsequent ly opened the door to participation in the NSF-supported High Magnetic Fie lds (HMF) beamline initiative and to continuing doctoral studies at the Un iversity of Puerto Rico\, Río Piedras. Beyond the scientific findings\, t his work demonstrates how access to national facilities and NSF-supported programs can foster the development of young scientists\, strengthen colla borations\, and expand opportunities for advanced research in Puerto Rico. \n\nhttps://events.saip.org.za/event/274/contributions/10362/ LOCATION: URL:https://events.saip.org.za/event/274/contributions/10362/ END:VEVENT END:VCALENDAR