Semi-Supervised Learning with Context-Conditional Generative Adversarial Networks

We introduce a simple semi-supervised learning approach for images based on in-painting using an adversarial loss. Images with random patches removed are presented to a generator whose task is to fill in the hole, based on the surrounding pixels. The in-painted images are then presented to a discriminator network that judges if they are real (unaltered training images) or not. This task acts as a regularizer for standard supervised training of the discriminator. Using our approach we are able to directly train large VGG-style networks in a semi-supervised fashion. We evaluate on STL-10 and PASCAL datasets, where our approach obtains performance comparable or superior to existing methods

AI's Regimes of Representation: A Community-centered Study of Text-to-Image Models in South Asia

This paper presents a community-centered study of cultural limitations of text-to-image (T2I) models in the South Asian context. We theorize these failures using scholarship on dominant media regimes of representations and locate them within participants' reporting of their existing social marginalizations. We thus show how generative AI can reproduce an outsiders gaze for viewing South Asian cultures, shaped by global and regional power inequities. By centering communities as experts and soliciting their perspectives on T2I limitations, our study adds rich nuance into existing evaluative frameworks and deepens our understanding of the culturally-specific ways AI technologies can fail in non-Western and Global South settings. We distill lessons for responsible development of T2I models, recommending concrete pathways forward that can allow for recognition of structural inequalities

Whose Ground Truth? Accounting for Individual and Collective Identities Underlying Dataset Annotation

Human annotations play a crucial role in machine learning (ML) research and development. However, the ethical considerations around the processes and decisions that go into building ML datasets has not received nearly enough attention. In this paper, we survey an array of literature that provides insights into ethical considerations around crowdsourced dataset annotation. We synthesize these insights, and lay out the challenges in this space along two layers: (1) who the annotator is, and how the annotators' lived experiences can impact their annotations, and (2) the relationship between the annotators and the crowdsourcing platforms and what that relationship affords them. Finally, we put forth a concrete set of recommendations and considerations for dataset developers at various stages of the ML data pipeline: task formulation, selection of annotators, platform and infrastructure choices, dataset analysis and evaluation, and dataset documentation and release

PLoS One

Quantitative analysis of the vascular network anatomy is critical for the understanding of the vasculature structure and function. In this study, we have combined microcomputed tomography (microCT) and computational analysis to provide quantitative three-dimensional geometrical and topological characterization of the normal kidney vasculature, and to investigate how 2 core genes of the Wnt/planar cell polarity, Frizzled4 and Frizzled6, affect vascular network morphogenesis. Experiments were performed on frizzled4 (Fzd4-/-) and frizzled6 (Fzd6-/-) deleted mice and littermate controls (WT) perfused with a contrast medium after euthanasia and exsanguination. The kidneys were scanned with a high-resolution (16 μm) microCT imaging system, followed by 3D reconstruction of the arterial vasculature. Computational treatment includes decomposition of 3D networks based on Diameter-Defined Strahler Order (DDSO). We have calculated quantitative (i) Global scale parameters, such as the volume of the vasculature and its fractal dimension (ii) Structural parameters depending on the DDSO hierarchical levels such as hierarchical ordering, diameter, length and branching angles of the vessel segments, and (iii) Functional parameters such as estimated resistance to blood flow alongside the vascular tree and average density of terminal arterioles. In normal kidneys, fractal dimension was 2.07±0.11 (n = 7), and was significantly lower in Fzd4-/- (1.71±0.04; n = 4), and Fzd6-/- (1.54±0.09; n = 3) kidneys. The DDSO number was 5 in WT and Fzd4-/-, and only 4 in Fzd6-/-. Scaling characteristics such as diameter and length of vessel segments were altered in mutants, whereas bifurcation angles were not different from WT. Fzd4 and Fzd6 deletion increased vessel resistance, calculated using the Hagen-Poiseuille equation, for each DDSO, and decreased the density and the homogeneity of the distal vessel segments. Our results show that our methodology is suitable for 3D quantitative characterization of vascular networks, and that Fzd4 and Fzd6 genes have a deep patterning effect on arterial vessel morphogenesis that may determine its functional efficiency

ViSAGe: A Global-Scale Analysis of Visual Stereotypes in Text-to-Image Generation

Recent studies have shown that Text-to-Image (T2I) model generations can reflect social stereotypes present in the real world. However, existing approaches for evaluating stereotypes have a noticeable lack of coverage of global identity groups and their associated stereotypes. To address this gap, we introduce the ViSAGe (Visual Stereotypes Around the Globe) dataset to enable the evaluation of known nationality-based stereotypes in T2I models, across 135 nationalities. We enrich an existing textual stereotype resource by distinguishing between stereotypical associations that are more likely to have visual depictions, such as `sombrero', from those that are less visually concrete, such as 'attractive'. We demonstrate ViSAGe's utility through a multi-faceted evaluation of T2I generations. First, we show that stereotypical attributes in ViSAGe are thrice as likely to be present in generated images of corresponding identities as compared to other attributes, and that the offensiveness of these depictions is especially higher for identities from Africa, South America, and South East Asia. Second, we assess the stereotypical pull of visual depictions of identity groups, which reveals how the 'default' representations of all identity groups in ViSAGe have a pull towards stereotypical depictions, and that this pull is even more prominent for identity groups from the Global South. CONTENT WARNING: Some examples contain offensive stereotypes.Comment: Association for Computational Linguistics (ACL) 202

Practicing inclusivity in AI: stakeholder engagement policy in action

Despite growing demand for participatory approaches for AI development, there are challenges of ensuring ethical and inclusive stakeholder engagement and preventing "participant-washing" and perpetuating harm to marginalized communities. To help support AI-developing teams and practitioners more ethically and responsibly work with communities and the public, the Partnership on AI's Global Task Force for Inclusive AI proposed specific guidance and resources. This one-day workshop brings together researchers and practitioners to co-create context-specific stakeholder engagement strategies using these draft guidelines. The workshop will provide a platform to acquire new understandings of stakeholder engagement practices and exchange ideas and experiences with implementing stakeholder engagements. Through hands-on application and feedback, the workshop aims to develop participants' practical expertise in ethical stakeholder engagement and refine the guidelines to ensure its applicability in real-world contexts. We aspire to build an active community that supports inclusive AI-driven solutions based on more equitable relationships between developers and the communities who are impacted by the technologies created

The size of the HIV-1 reservoir was unchanged by romidepsin.

<p>Panels (<b>A)</b> to (<b>E)</b> show measures of the size of the viral reservoir as well as in the inducible HIV-1 reservoir during romidepsin treatment. <b>(A)</b> Absolute levels of total HIV-1 DNA per 10⁶ CD4⁺ T cells. (<b>B</b>) Fold changes in total HIV-1 DNA per 10⁶ CD4⁺ T cells. <b>(C)</b> Absolute levels of 2-LTR HIV-1 DNA per 10⁶ CD4⁺ T cells. <b>(D)</b> Frequency of cells with multiply spliced HIV RNA upon maximal cellular activation with PMA/ionomycin as measured using a tat/rev induced limiting dilution assay (TILDA). (<b>E</b>) shows results from a quantitative viral outgrowth assay (qVOA) which was used to assess the frequency of resting CD4⁺ cells carrying inducible replication competent proviruses at baseline and day 56. LoQ, limit of quantitation; Lod, limit of detection; IUBM, infectious units per million.</p

HIV-specific T cell responses were preserved during romidepsin treatment.

<p>Flow cytometric characterization of HIV-gag-specific CD8⁺ and CD4⁺ T cells within the memory subsets at baseline (Base, <i>n</i> = 6), on treatment (ROMI, <i>n</i> = 5) and at follow-up (Post, <i>n</i> = 6). Proportion of EM (<b>A</b>) and TD (<b>B</b>) CD8⁺ T cells producing only IFNγ or both IFNγ and TNFα. Horizontal bars show median values. <b>(C, D)</b> Median fluorescence intensity (MFI) for IFNγ and TNFα for HIV-specific EM CD8⁺ T cells and <b>(E, F)</b> TD CD8⁺ T cells identified in Panels A-B. <b>(G)</b>, Proportion of polyfunctional memory EM CD4⁺ T cells producing IFNγ, TNFα and IL-2. <b>(H)</b> Expression levels (MFI) for each cytokine (i.e. IL-2, TNFα and IFNγ) examined on the polyfunctional HIV-specific EM CD4⁺ T cells identified in panel <b>(G)</b> TD, terminally differentiated; EM, effector memory. Statistical comparisons were performed using Wilcoxon matched-pairs signed-ranks test, Asterisk indicate p<0.05.</p

Baseline characteristics of the six study participants at enrolment.

<p>^AOne patient had one blip, 2.3 years prior to inclusion (81 copies/mL), another patient had two blips, latest blip (64 copies/mL) 9.3 years prior to inclusion.</p><p>Baseline characteristics of the six study participants at enrolment.</p

Flow diagram.

<p>The flow diagram shows information about the method of recruitment and the number of patients undergoing romidepsin treatment.</p