SITA

Jingdan Kang, Haoxin Yang, Yan Cai, Huaidong Zhang, Xuemiao Xu, Yong Du, Shengfeng He

Image generation technology has brought significant advancements across various fields but has also raised concerns about data misuse and potential rights infringements, particularly with respect to creating visual artworks. Current methods aimed at safeguarding artworks often employ adversarial attacks. However, these methods face challenges such as poor transferability, high computational costs, and the introduction of noticeable noise, which compromises the aesthetic quality of the original artwork. To address these limitations, we propose a Structurally Imperceptible and Transferable Adversarial (SITA) attacks. SITA leverages a CLIP-based destylization loss, which decouples and disrupts the robust style representation of the image. This disruption hinders style extraction during stylized image generation, thereby impairing the overall stylization process. Importantly, SITA eliminates the need for a surrogate diffusion model, leading to significantly reduced computational overhead. The method’s robust style feature disruption ensures high transferability across diverse models. Moreover, SITA introduces perturbations by embedding noise within the imperceptible structural details of the image. This approach effectively protects against style extraction without compromising the visual quality of the artwork. Extensive experiments demonstrate that SITA offers superior protection for artworks against unauthorized use in stylized generation. It significantly outperforms existing methods in terms of transferability, computational efficiency, and noise imperceptibility. Code is available at https://github.com/A-raniy-day/SITA.

Lindelwa Komna, Sabelo Mpungose

This study intends to assess the impact of digital transformation on public sector service delivery, concentrating on the State Information Technology Agency (SITA) in South Africa. The report examines critical obstacles obstructing the effective execution of digital transformation programs, including as antiquated infrastructure, procurement inefficiencies, and opposition to change. It also analyses the advantages of agile approaches in improving flexibility, responsiveness, and collaboration in digital projects. We utilised a qualitative study methodology, conducting semi-structured interviews with SITA personnel and analysing pertinent organisational documents. The dataset comprised interviews with personnel from several departments, together with performance and service delivery reports spanning from 2015 to 2022. The study's principal findings indicate that (i) agile methodologies markedly enhance the adaptability and efficiency of digital transformation initiatives; (ii) robust data governance and sharing practices promote transparency and accountability, albeit encountering obstacles such as data silos and inconsistent quality; and (iii) addressing challenges such as digital hesitancy and leadership deficiencies is crucial for cultivating a culture that encourages innovation and continuous improvement. The study ultimately offers strategic recommendations for tackling these difficulties and improving digital transformation initiatives inside SITA.  

Yewei Cun, H. Ding, Tiantian Mao, Yuan Wang, Caicui Wang, Jiajun Li, Zihao Li, Mengdie Hu, Zhiwei Cao, Tianyi Qiu

Antibody humanization is critical to reduce immunogenicity and enhance efficacy in the preclinical phase of the development of therapeutic antibodies originated from animal models. Computational suggestions have long been desired, but available tools focused on immunogenicity calculation of whole antibody sequences and sequence segments, missing the individual residue sites. This study introduces Site-specific Immunogenicity for Therapeutic Antibody (SITA), a novel computational framework that predicts B-cell immunogenicity score for not only the overall antibody, but also individual residues, based on a comprehensive set of amino acid descriptors characterizing physicochemical and spatial features for antibody structures. A transfer-learning-inspired framework was purposely adopted to overcome the scarcity of Antibody-Antibody structural complexes. On an independent testing dataset derived from 13 Antibody-Antibody structural complexes, SITA successfully predicted the epitope sites for Antibody-Antibody structures with a receiver operating characteristic (ROC)-area unver the ROC curve (AUC) of 0.85 and a precision-recall (PR)-AUC of 0.305 at the residue level. Furthermore, the SITA score can significantly distinguish immunogenicity levels of whole human antibodies, therapeutic antibodies and non-human-derived antibodies. More importantly, analysis of an additional 25 therapeutic antibodies revealed that over 70% of them were detected with decreased immunogenicity after modification compared to their parent variants. Among these, nearly 66% antibodies successfully identified actual modification sites from the top five sites with the highest SITA scores, suggesting the ability of SITA scores for guide the humanization of antibody. Overall, these findings highlight the potential of SITA in optimizing immunogenicity assessments during the process of therapeutic antibody design.

Joyce Tiang, A. Vingrys, Sarah Lin, Selwyn M. Prea, Adam A Moktar, A. Bank, Ashish Agar, Yu Xiang George Kong

Purpose Visual field testing is important for glaucoma diagnosis and management, but access to standard automated perimetry can be limited in some areas due to cost or access. Melbourne Rapid Fields-web (MRF-web) perimeter is designed to address these limitations by allowing perimetry testing on the flat screen of your personal computer. Methods This study is a retrospective, cross-sectional study involving two locations in Australia, one in metropolitan Melbourne and one in rural Dubbo NSW. 232 patients with stable glaucoma, glaucoma suspect or normal eyes were tested with MRF-web and outcomes were compared to the most recent Humphrey Field Analyzer (HFA) 24-2 SITA Faster test. Outcomes were compared by Deming regressions, Intraclass Correlation Coefficients (ICC) and Bland-Altman methods. Results Patient age ranged from 21 to 92 (average 66.3, SD 16.1). Bland-Altman found a bias of -0.50dB for Mean Deviation (MD) between the two tests, with 95% Limits of Agreement (LoA) of -6.80dB to 5.80dB. Pattern Deviation (PD) had a bias of -0.58dB with 95% LoA of -5.60dB to 4.40dB. High concordance was found for MD and PD, with ICCs of 0.87 and 0.73. No significant differences were found in false positive and fixation loss rates. Test time was approximately one minute longer for MRF-web compared to SITA-Faster. Area Under the Curve of MRF and HFA are similar indicating comparable diagnostic capacity. Conclusion MRF-web produces outcomes comparable to HFA SITA-Faster. Its portability and cost-effectiveness suggest suitability as an alternative method for visual field testing where a standard perimeter is not easily accessible.

Chris Bradley, Alex Pham, Jithin Yohannan

Objective: Determine how sensitivities below the measurement floor of the Humphrey Field Analyzer change when transitioning from Swedish Interactive Thresholding Algorithm (SITA) Standard to SITA-Fast and SITA-Faster strategies. Design: Retrospective descriptive study Participants: A total of 21,468 24–2 SITA-Standard, 4872 SITA-Fast and 3468 SITA-Faster VFs from 7917 glaucoma and glaucoma suspect eyes with at least 5 VFs between 1997 and 2023 at the Wilmer Eye Institute. Methods: At each test location of the 24–2 test pattern, we measured the probability that <0 dB at a given test location on two baseline SITA-Standard VFs was M dB or higher on the first SITA-Fast or SITA-Faster post-baseline VF for different values of M > 0. Results were compared to using the same test strategy for both baseline and post-baseline VFs. Main outcome measures: Probability of <0 dB at baseline being measured as M > 0 dB or higher on the first post-baseline VF. Results: At M = 7 dB, which was approximately one standard deviation above the mean for post-baseline SITA-Standard sensitivities, average percent change from <0 dB across all test locations was 10.3 % for SITA-Standard, 15.8 % for SITA-Fast and 25.5 % for SITA-Faster. Percent change from <0 dB for all M tested (up to M = 20) was consistently higher near the macula compared to overall averages: on average 1.3 % higher for SITA-Standard, 1.5 % higher for SITA-Fast, and 6.3 % higher for SITA-Faster. Conclusions: Increased caution is advised when following the progression of <0 dB defects during a transition from SITA-Standard to SITA-Fast or SITA-Faster.