124 research outputs found

    Intelligent Coordination of Traditional Power Plants and Inverters Air Conditioners Controlled With Feedback-Corrected MPC in LFC

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    Demand response programs have been receiving more serious attention as alternatives for participating in load frequency control. Inverter air conditioners (IAC) are acknowledged as suitable devices for demand response due to their increasing contribution to network consumption. Despite their potential, their use presents challenges, including delayed responses, variable interference, and the absence of coordination with traditional generation units, which may affect control performance. Also, existing control strategies fail to consider operational and physical constraints, resulting in possible model mismatches. In this paper, a model predictive control with feedback correction (MPCFC) is proposed to dispatch control signals to the IACs so they can effectively participate in the frequency control of an interconnected power system. The feedback correction method is presented to enhance prediction accuracy in the MPC and weaken the influence of model parameter mismatches and external disturbances. Furthermore, to minimize the impacts of communication delays on frequency overshoot/undershoot, this study introduces an intelligent supervisory coordinator based on an artificial neural network to coordinate the reaction of traditional generation units and IACs to correct significant frequency variations brought on by the time delays. The effectiveness of the developed control scheme is verified through numerical studies by comparing it with the IAC with PI and MPC controllers (without coordinator) and the system without IACs. Case studies are investigated on a two-area power system in MATLAB/Simulink environment, and the OPAL-RT real-time simulator is used to validate the results.</p

    Negative effects of urbanisation on diurnal and nocturnal pollen‐transport networks

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    Pollinating insects are declining due to habitat loss and climate change, and cities with limited habitat and floral resources may be particularly vulnerable. The effects of urban landscapes on pollination networks remain poorly understood, and comparative studies of taxa with divergent niches are lacking. Here, for the first time, we simultaneously compare nocturnal moth and diurnal bee pollen-transport networks using DNA metabarcoding and ask how pollination networks are affected by increasing urbanisation. Bees and moths exhibited substantial divergence in the communities of plants they interact with. Increasing urbanisation had comparable negative effects on pollen-transport networks of both taxa, with significant declines in pollen species richness. We show that moths are an important, but overlooked, component of urban pollen-transport networks for wild flowering plants, horticultural crops, and trees. Our findings highlight the need to include both bee and non-bee taxa when assessing the status of critical plant-insect interactions in urbanised landscapes

    Germline pathogenic variants in HNRNPU are associated with alterations in blood methylome

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    HNRNPU encodes a multifunctional RNA-binding protein that plays critical roles in regulating pre-mRNA splicing, mRNA stability, and translation. Aberrant expression and dysregulation of HNRNPU have been implicated in various human diseases, including cancers and neurological disorders. We applied a next generation sequencing based assay (EPIC-NGS) to investigate genome-wide methylation profiling for >2 M CpGs for 7 individuals with a neurodevelopmental disorder associated with HNRNPU germline pathogenic loss-of-function variants. Compared to healthy individuals, 227 HNRNPU-associated differentially methylated positions were detected. Both hyper- and hypomethylation alterations were identified but the former predominated. The identification of a methylation episignature for HNRNPU-associated neurodevelopmental disorder (NDD) implicates HNPRNPU-related chromatin alterations in the aetiopathogenesis of this disorder and suggests that episignature profiling should have clinical utility as a predictor for the pathogenicity of HNRNPU variants of uncertain significance. The detection of a methylation episignaure for HNRNPU-associated NDD is consistent with a recent report of a methylation episignature for HNRNPK-associated NDD

    Time evolution of in vivo articular cartilage repair induced by bone marrow stimulation and scaffold implantation in rabbits

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    Purpose: Tissue engineering techniques were used to study cartilage repair over a 12-month period in a rabbit model. Methods: A full-depth chondral defect along with subchondral bone injury were originated in the knee joint, where a biostable porous scaffold was implanted, synthesized of poly(ethyl acrylate-co-hydroxyethyl acrylate) copolymer. Morphological evolution of cartilage repair was studied 1 and 2 weeks, and 1, 3, and 12 months after implantation by histological techniques. The 3-month group was chosen to compare cartilage repair to an additional group where scaffolds were preseeded with allogeneic chondrocytes before implantation, and also to controls, who underwent the same surgery procedure, with no scaffold implantation. Results: Neotissue growth was first observed in the deepest scaffold pores 1 week after implantation, which spread thereafter; 3 months later scaffold pores were filled mostly with cartilaginous tissue in superficial and middle zones, and with bone tissue adjacent to subchondral bone. Simultaneously, native chondrocytes at the edges of the defect started to proliferate 1 week after implantation; within a month those edges had grown centripetally and seemed to embed the scaffold, and after 3 months, hyaline-like cartilage was observed on the condylar surface. Preseeded scaffolds slightly improved tissue growth, although the quality of repair tissue was similar to non-preseeded scaffolds. Controls showed that fibrous cartilage was mainly filling the repair area 3 months after surgery. In the 12-month group, articular cartilage resembled the untreated surface. Conclusions: Scaffolds guided cartilaginous tissue growth in vivo, suggesting their importance in stress transmission to the cells for cartilage repair.This study was supported by the Spanish Ministry of Science and Innovation through MAT2010-21611-C03-00 project (including the FEDER financial support), by Conselleria de Educacion (Generalitat Valenciana, Spain) PROMETEO/2011/084 grant, and by CIBER-BBN en Bioingenieria, Biomateriales y Nanomedicina. The work of JLGR was partially supported by funds from the Generalitat Valenciana, ACOMP/2012/075 project. CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the - Instituto de Salud Carlos III with assistance from the European Regional Development Fund.Sancho-Tello Valls, M.; Forriol, F.; Gastaldi, P.; Ruiz Sauri, A.; MartĂ­n De Llano, JJ.; Novella-Maestre, E.; Antolinos TurpĂ­n, CM.... (2015). Time evolution of in vivo articular cartilage repair induced by bone marrow stimulation and scaffold implantation in rabbits. International Journal of Artificial Organs. 38(4):210-223. https://doi.org/10.5301/ijao.5000404S210223384Becerra, J., Andrades, J. A., Guerado, E., Zamora-Navas, P., LĂłpez-Puertas, J. M., & Reddi, A. H. (2010). Articular Cartilage: Structure and Regeneration. Tissue Engineering Part B: Reviews, 16(6), 617-627. doi:10.1089/ten.teb.2010.0191Nelson, L., Fairclough, J., & Archer, C. (2009). Use of stem cells in the biological repair of articular cartilage. Expert Opinion on Biological Therapy, 10(1), 43-55. doi:10.1517/14712590903321470MAINIL-VARLET, P., AIGNER, T., BRITTBERG, M., BULLOUGH, P., HOLLANDER, A., HUNZIKER, E., 
 STAUFFER, E. (2003). HISTOLOGICAL ASSESSMENT OF CARTILAGE REPAIR. The Journal of Bone and Joint Surgery-American Volume, 85, 45-57. doi:10.2106/00004623-200300002-00007Hunziker, E. B., Kapfinger, E., & Geiss, J. (2007). The structural architecture of adult mammalian articular cartilage evolves by a synchronized process of tissue resorption and neoformation during postnatal development. Osteoarthritis and Cartilage, 15(4), 403-413. doi:10.1016/j.joca.2006.09.010Onyekwelu, I., Goldring, M. B., & Hidaka, C. (2009). Chondrogenesis, joint formation, and articular cartilage regeneration. Journal of Cellular Biochemistry, 107(3), 383-392. doi:10.1002/jcb.22149Ahmed, T. A. E., & Hincke, M. T. (2010). Strategies for Articular Cartilage Lesion Repair and Functional Restoration. Tissue Engineering Part B: Reviews, 16(3), 305-329. doi:10.1089/ten.teb.2009.0590Hangody, L., Kish, G., KĂĄrpĂĄti, Z., Udvarhelyi, I., Szigeti, I., & BĂ©ly, M. (1998). Mosaicplasty for the Treatment of Articular Cartilage Defects: Application in Clinical Practice. Orthopedics, 21(7), 751-756. doi:10.3928/0147-7447-19980701-04Steinwachs, M. R., Guggi, T., & Kreuz, P. C. (2008). Marrow stimulation techniques. Injury, 39(1), 26-31. doi:10.1016/j.injury.2008.01.042Brittberg, M., Lindahl, A., Nilsson, A., Ohlsson, C., Isaksson, O., & Peterson, L. (1994). Treatment of Deep Cartilage Defects in the Knee with Autologous Chondrocyte Transplantation. New England Journal of Medicine, 331(14), 889-895. doi:10.1056/nejm199410063311401Richter, W. (2009). Mesenchymal stem cells and cartilagein situregeneration. Journal of Internal Medicine, 266(4), 390-405. doi:10.1111/j.1365-2796.2009.02153.xBartlett, W., Skinner, J. A., Gooding, C. R., Carrington, R. W. J., Flanagan, A. M., Briggs, T. W. R., & Bentley, G. (2005). Autologous chondrocyte implantationversusmatrix-induced autologous chondrocyte implantation for osteochondral defects of the knee. The Journal of Bone and Joint Surgery. British volume, 87-B(5), 640-645. doi:10.1302/0301-620x.87b5.15905Little, C. J., Bawolin, N. K., & Chen, X. (2011). Mechanical Properties of Natural Cartilage and Tissue-Engineered Constructs. Tissue Engineering Part B: Reviews, 17(4), 213-227. doi:10.1089/ten.teb.2010.0572Vikingsson, L., Gallego Ferrer, G., GĂłmez-Tejedor, J. A., & GĂłmez Ribelles, J. L. (2014). An «in vitro» experimental model to predict the mechanical behavior of macroporous scaffolds implanted in articular cartilage. Journal of the Mechanical Behavior of Biomedical Materials, 32, 125-131. doi:10.1016/j.jmbbm.2013.12.024Weber, J. F., & Waldman, S. D. (2014). Calcium signaling as a novel method to optimize the biosynthetic response of chondrocytes to dynamic mechanical loading. Biomechanics and Modeling in Mechanobiology, 13(6), 1387-1397. doi:10.1007/s10237-014-0580-xMauck, R. L., Soltz, M. A., Wang, C. C. B., Wong, D. D., Chao, P.-H. G., Valhmu, W. B., 
 Ateshian, G. A. (2000). Functional Tissue Engineering of Articular Cartilage Through Dynamic Loading of Chondrocyte-Seeded Agarose Gels. Journal of Biomechanical Engineering, 122(3), 252-260. doi:10.1115/1.429656Palmoski, M. J., & Brandt, K. D. (1984). Effects of static and cyclic compressive loading on articular cartilage plugs in vitro. Arthritis & Rheumatism, 27(6), 675-681. doi:10.1002/art.1780270611Khoshgoftar, M., Ito, K., & van Donkelaar, C. C. (2014). The Influence of Cell-Matrix Attachment and Matrix Development on the Micromechanical Environment of the Chondrocyte in Tissue-Engineered Cartilage. Tissue Engineering Part A, 20(23-24), 3112-3121. doi:10.1089/ten.tea.2013.0676Agrawal, C. M., & Ray, R. B. (2001). Biodegradable polymeric scaffolds for musculoskeletal tissue engineering. Journal of Biomedical Materials Research, 55(2), 141-150. doi:10.1002/1097-4636(200105)55:23.0.co;2-jPĂ©rez Olmedilla, M., Garcia-Giralt, N., Pradas, M. M., Ruiz, P. B., GĂłmez Ribelles, J. L., Palou, E. C., & GarcĂ­a, J. C. M. (2006). Response of human chondrocytes to a non-uniform distribution of hydrophilic domains on poly (ethyl acrylate-co-hydroxyethyl methacrylate) copolymers. Biomaterials, 27(7), 1003-1012. doi:10.1016/j.biomaterials.2005.07.030Horbett, T. A., & Schway, M. B. (1988). Correlations between mouse 3T3 cell spreading and serum fibronectin adsorption on glass and hydroxyethylmethacrylate-ethylmethacrylate copolymers. Journal of Biomedical Materials Research, 22(9), 763-793. doi:10.1002/jbm.820220903Kiremitçi, M., PeƟmen, A., Pulat, M., & GĂŒrhan, I. (1993). Relationship of Surface Characteristics to Cellular Attachment in PU and PHEMA. Journal of Biomaterials Applications, 7(3), 250-264. doi:10.1177/088532829300700304Lydon, M. ., Minett, T. ., & Tighe, B. . (1985). Cellular interactions with synthetic polymer surfaces in culture. Biomaterials, 6(6), 396-402. doi:10.1016/0142-9612(85)90100-0Campillo-Fernandez, A. J., Pastor, S., Abad-Collado, M., Bataille, L., Gomez-Ribelles, J. L., Meseguer-Dueñas, J. M., 
 Ruiz-Moreno, J. M. (2007). Future Design of a New Keratoprosthesis. Physical and Biological Analysis of Polymeric Substrates for Epithelial Cell Growth. Biomacromolecules, 8(8), 2429-2436. doi:10.1021/bm0703012Funayama, A., Niki, Y., Matsumoto, H., Maeno, S., Yatabe, T., Morioka, H., 
 Toyama, Y. (2008). Repair of full-thickness articular cartilage defects using injectable type II collagen gel embedded with cultured chondrocytes in a rabbit model. Journal of Orthopaedic Science, 13(3), 225-232. doi:10.1007/s00776-008-1220-zKitahara, S., Nakagawa, K., Sah, R. L., Wada, Y., Ogawa, T., Moriya, H., & Masuda, K. (2008). In Vivo Maturation of Scaffold-free Engineered Articular Cartilage on Hydroxyapatite. Tissue Engineering Part A, 14(11), 1905-1913. doi:10.1089/ten.tea.2006.0419Martinez-Diaz, S., Garcia-Giralt, N., Lebourg, M., GĂłmez-Tejedor, J.-A., Vila, G., Caceres, E., 
 Monllau, J. C. (2010). In Vivo Evaluation of 3-Dimensional Polycaprolactone Scaffolds for Cartilage Repair in Rabbits. The American Journal of Sports Medicine, 38(3), 509-519. doi:10.1177/0363546509352448Wang, Y., Bian, Y.-Z., Wu, Q., & Chen, G.-Q. (2008). Evaluation of three-dimensional scaffolds prepared from poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) for growth of allogeneic chondrocytes for cartilage repair in rabbits. Biomaterials, 29(19), 2858-2868. doi:10.1016/j.biomaterials.2008.03.021AliĂł del Barrio, J. L., Chiesa, M., Gallego Ferrer, G., Garagorri, N., Briz, N., Fernandez-Delgado, J., 
 De Miguel, M. P. (2014). Biointegration of corneal macroporous membranes based on poly(ethyl acrylate) copolymers in an experimental animal model. Journal of Biomedical Materials Research Part A, 103(3), 1106-1118. doi:10.1002/jbm.a.35249Diego, R. B., Olmedilla, M. P., Aroca, A. S., Ribelles, J. L. G., Pradas, M. M., Ferrer, G. G., & SĂĄnchez, M. S. (2005). Acrylic scaffolds with interconnected spherical pores and controlled hydrophilicity for tissue engineering. Journal of Materials Science: Materials in Medicine, 16(8), 693-698. doi:10.1007/s10856-005-2604-7Serrano Aroca, A., Campillo FernĂĄndez, A. J., GĂłmez Ribelles, J. L., MonleĂłn Pradas, M., Gallego Ferrer, G., & Pissis, P. (2004). Porous poly(2-hydroxyethyl acrylate) hydrogels prepared by radical polymerisation with methanol as diluent. Polymer, 45(26), 8949-8955. doi:10.1016/j.polymer.2004.10.033Diani, J., Fayolle, B., & Gilormini, P. (2009). A review on the Mullins effect. European Polymer Journal, 45(3), 601-612. doi:10.1016/j.eurpolymj.2008.11.017Mullins, L. (1969). Softening of Rubber by Deformation. Rubber Chemistry and Technology, 42(1), 339-362. doi:10.5254/1.3539210Jurvelin, J. S., Buschmann, M. D., & Hunziker, E. B. (2003). Mechanical anisotropy of the human knee articular cartilage in compression. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 217(3), 215-219. doi:10.1243/095441103765212712Shapiro, F., Koide, S., & Glimcher, M. J. (1993). Cell origin and differentiation in the repair of full-thickness defects of articular cartilage. The Journal of Bone & Joint Surgery, 75(4), 532-553. doi:10.2106/00004623-199304000-00009SELLERS, R. S., ZHANG, R., GLASSON, S. S., KIM, H. D., PELUSO, D., D’AUGUSTA, D. A., 
 MORRIS, E. A. (2000). Repair of Articular Cartilage Defects One Year After Treatment with Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2)*. The Journal of Bone and Joint Surgery-American Volume, 82(2), 151-160. doi:10.2106/00004623-200002000-00001Hunziker, E. B., Michel, M., & Studer, D. (1997). Ultrastructure of adult human articular cartilage matrix after cryotechnical processing. Microscopy Research and Technique, 37(4), 271-284. doi:10.1002/(sici)1097-0029(19970515)37:43.0.co;2-oAppelman, T. P., Mizrahi, J., Elisseeff, J. H., & Seliktar, D. (2009). The differential effect of scaffold composition and architecture on chondrocyte response to mechanical stimulation. Biomaterials, 30(4), 518-525. doi:10.1016/j.biomaterials.2008.09.063Chung, C., & Burdick, J. A. (2008). Engineering cartilage tissue. Advanced Drug Delivery Reviews, 60(2), 243-262. doi:10.1016/j.addr.2007.08.027HUNZIKER, E. B., & ROSENBERG, L. C. (1996). Repair of Partial-Thickness Defects in Articular Cartilage. The Journal of Bone & Joint Surgery, 78(5), 721-33. doi:10.2106/00004623-199605000-00012Schulze-Tanzil, G. (2009). Activation and dedifferentiation of chondrocytes: Implications in cartilage injury and repair. Annals of Anatomy - Anatomischer Anzeiger, 191(4), 325-338. doi:10.1016/j.aanat.2009.05.003Umlauf, D., Frank, S., Pap, T., & Bertrand, J. (2010). Cartilage biology, pathology, and repair. Cellular and Molecular Life Sciences, 67(24), 4197-4211. doi:10.1007/s00018-010-0498-0Karystinou, A., Dell’Accio, F., Kurth, T. B. A., Wackerhage, H., Khan, I. M., Archer, C. W., 
 De Bari, C. (2009). Distinct mesenchymal progenitor cell subsets in the adult human synovium. Rheumatology, 48(9), 1057-1064. doi:10.1093/rheumatology/kep192Sakaguchi, Y., Sekiya, I., Yagishita, K., & Muneta, T. (2005). Comparison of human stem cells derived from various mesenchymal tissues: Superiority of synovium as a cell source. Arthritis & Rheumatism, 52(8), 2521-2529. doi:10.1002/art.21212Schaefer, D., Martin, I., Jundt, G., Seidel, J., Heberer, M., Grodzinsky, A., 
 Freed, L. E. (2002). Tissue-engineered composites for the repair of large osteochondral defects. Arthritis & Rheumatism, 46(9), 2524-2534. doi:10.1002/art.1049

    Age at first birth in women is genetically associated with increased risk of schizophrenia

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    Prof. Paunio on PGC:n jÀsenPrevious studies have shown an increased risk for mental health problems in children born to both younger and older parents compared to children of average-aged parents. We previously used a novel design to reveal a latent mechanism of genetic association between schizophrenia and age at first birth in women (AFB). Here, we use independent data from the UK Biobank (N = 38,892) to replicate the finding of an association between predicted genetic risk of schizophrenia and AFB in women, and to estimate the genetic correlation between schizophrenia and AFB in women stratified into younger and older groups. We find evidence for an association between predicted genetic risk of schizophrenia and AFB in women (P-value = 1.12E-05), and we show genetic heterogeneity between younger and older AFB groups (P-value = 3.45E-03). The genetic correlation between schizophrenia and AFB in the younger AFB group is -0.16 (SE = 0.04) while that between schizophrenia and AFB in the older AFB group is 0.14 (SE = 0.08). Our results suggest that early, and perhaps also late, age at first birth in women is associated with increased genetic risk for schizophrenia in the UK Biobank sample. These findings contribute new insights into factors contributing to the complex bio-social risk architecture underpinning the association between parental age and offspring mental health.Peer reviewe

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Large-scale discovery of novel genetic causes of developmental disorders

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    Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders1, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach2 to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing3,4,5,6,7,8,9,10,11 and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Can finite element models detect clinically inferior cemented hip implants?

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    Rigorous preclinical testing of cemented hip prostheses against the damage accumulation failure scenario will reduce the incidence of aseptic loosening. For that purpose, a finite element simulation is proposed that predicts damage accumulation in the cement mantle and prosthetic migration. If the simulation is to become a convincing preclinical test, it should be able to distinguish between implants in a clinically relevant way, based on accurate predictions of long-term failure mechanisms of cemented hip prostheses. The algorithm was used to simulate long-term fatigue experiments on femoral reconstructions with Mueller Curved and Lubinus SPII stems. Clinically, the Mueller Curved system performs inferior to the Lubinus SPII system. The finite element simulation predicted much more cement damage around the Mueller Curved stem and showed that the entire cement mantle was involved in the failure process, which was not the case around the Lubinus SPII stem. In addition, the Mueller Curved stem was predicted to migrate more than the Lubinus SPII. The predictions showed excellent agreement with the experimental findings: similar damage locations in the cement, more damage for the Mueller Curved, similar prosthetic migration directions, and more migration for the Mueller Curved stem. This is the first time that a finite element simulation is able to differentiate between a clinically superior and an inferior implant, based on accurate simulation of the long-term failure mechanisms in a cemented reconstruction. Its use for preclinical testing purposes is corroborated
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