Baker Engineering (United States)

Contrast modulation (CM) stimuli have been previously used to reveal nonlinear contributions of Y-like retinal ganglion cells (RGCs) such as parasol cells to cortical responses and perception. To test whether CMs are selectively processed within the magnocellular pathway, we assessed envelope motion discrimination and detection for achromatic (yellow-black) and chromatic (red-green) CMs in the presence of luminance masking noise to disrupt luminance-based mechanisms of motion processing. Compared to achromatic CMs, perception of chromatic CMs was more sensitive to luminance masking noise, suggesting that CM envelope motion perception relied predominantly on luminance signals. Specifically, envelope motion discrimination performance was better maintained for achromatic CMs than chromatic CMs, even at high masking noise levels. Notably, luminance masking noise greatly impaired envelope direction discrimination for chromatic CMs but had minimal impact on their detection, suggesting that chromatic aberrations may enhance envelope motion perception for chromatic CMs by introducing luminance signals. These findings reinforce previous neurophysiological and psychophysical evidence that CM stimuli selectively engage the nonlinear receptive field mechanisms of Y-like/parasol RGCs within the magnocellular retinogeniculate pathway, underscoring their potential to specifically target this pathway.

We have shown that single-pulse transcranial magnetic stimulation (TMS) of the dorsolateral prefrontal cortex (dlPFC) inhibits muscle sympathetic nerve activity. However, this was likely due to arousal caused by the TMS pulses themselves, rather than altering the underlying neuronal circuitry. In extension, we have aimed to explore the effects of single-pulse TMS on skin sympathetic nerve activity (SSNA), which is more sensitive to arousal. It was hypothesised that TMS-evoked arousal would increase SSNA but would not generate de novo bursts from the dlPFC. Microneurographic recordings were taken from the right common peroneal nerve in 10 participants. TMS pulses were then delivered to the ipsilateral dlPFC at resting motor threshold (MT) of the finger, at stimulator output intensities 20% and 10% below MT, and at 110% and 120% of MT. The MT and 110% of MT intensities were also used in stimulating the right motor cortex and shoulder. Reductions in SSNA from baseline were seen at almost all intensities, and these mostly did not differ between intensities or sites despite the appearance of SSNA bursts after each pulse. This suggests that TMS is simply generating an arousal response, leading to initial excitation of SSNA followed by a period of sympathoinhibition.

This study assessed the validity of a widely used standardized exit exam (E2) as a predictor of Next Generation NCLEX (NGN) and examined the relationship between policies governing E2 use in programs and success on the NGN. A total of 32 programs across the United States and Canada provided NGN outcome information for 1,753 students who took the E2 in April to December 2023, and 36 programs provided information about their policies. Students who achieved an average E2 score of 850 and above had an NGN first-time pass rate (FTPR) of 98%, significantly higher than those with average scores under 850. Policies such as test preparation requirements and remediation for the E2 were associated with significantly higher student E2 benchmark attainment. This study presents updated evidence on the validity of the E2 and expands research in the ways specific policies can support student success on the E2 and, by extension, potentially the NGN.

Technology solutions in rural indigenous African contexts are too often grounded in top-down, needs-based development approaches. Participatory methods, such as Community-based Co-Design, oppose such tendencies and emphasise the participation of communities in the technology design process as culturally-situated experts. We extend and reflect on this premise by exploring the sequential co-design of a digital innovation game with a rural indigenous San community in Namibia as a base for alternative indigenous technology design and futuring. Through emerging insights, we note that despite the community’s complex and intertwined contemporary status quo resulting from a mix of experiences and interactions, it maintains a pronounced desire and connection with its own culture and traditions. As evidenced by the community’s reflections, recollections and constructs during the co-design process, this connection offers new design perspectives that not only counter inapt design concepts but enable alternative technology possibilities grounded in local contexts. Therefore, we argue for its broader consideration within technology endeavours and interventions in indigenous contexts; thereby, enabling a spectrum of local and indigenous innovations.

This report describes and documents the feasibility of constructing and maintaining a leak detection facility at various testing facilities currently in operation. It also documents the industry's current leak detection capabilities, as well as gaps in the current test facilities' abilities. These gaps include testing the existing leak detection technologies in manners consistent with analyzing real-world hydrocarbon pipeline leaks. This report also identifies important potential limiting factors in the facilities' designs and or/operations.

This paper presents the co-design and deployment of a culturally contextualized mobile interface aimed at enhancing transparency in an AI-and IoT-enabled hydroponics system within the Indigenous San community in Donkerbos, Namibia. Building on a previously implemented AI-driven hydroponic system developed in South Africa, the project introduces a webbased application tailored to local needs through CommunityBased Co-Design (CBCD). The design process emphasized relational accountability, local symbolism, and transparency to foster user agency and system usability. By integrating real-time data visualization, explanatory feedback, and interactive AI assistants powered by Large Language Models (LLMs), the application enabled community members to better understand and manage the system. Our findings demonstrate that transparent AI interactions can improve user agency and promote technological acceptance. This work contributes to the field of Responsible AI by illustrating how co-design can bridge technological and cultural contexts to support sustainable agriculture and digital inclusion in marginalized rural communities.

Representing legal norms by means of an adequate formalism is essential for the development of legally compliant autonomous systems. The remarkable variety of both formalisation and implementation frameworks proposed during the last decades enables the development of relatively efficient formalisations over a wide range of applications. Notwithstanding, this abundance of frameworks also leads to some practical problems, especially with respect to the integration of – or the translation between – different frameworks. While more or less widely applicable meta-formalisms are already available, they are often too complex and counter-intuitive, thus being clearly closer to the technical implementation than to the conception phase of the formalisation process. As a complementary, more human-oriented solution to the problem, the paper at hand introduces and discusses a more intuitive normal form structure, which is based on elements of legal theory and aims at facilitating the interdisciplinary communication among the many partners involved in the process of developing law-abiding machines.

Extracellular vesicles (EVs) are an essential signalling entity in human plasma implicated in health and disease. Still, their core protein and lipid componentry, which lie at the centre of EV form and function, remain poorly defined. Here we performed high-resolution density gradient fractionation of over 140 human plasma samples to isolate circulating EVs, and systematically constructed their quantitative proteome (4,500 proteins) and lipidome (829 lipids) landscapes using mass spectrometry. We identified a highly conserved panel of 182 proteins (including ADAM10, STEAP23 and STX7) and 52 lipids (including PS, PIPs, Hex2Cer and PAs), providing a deep survey of hallmark molecular features and biological pathways characteristic to circulating EVs. We also mapped the surfaceome diversity, identifying 151 proteins on the EV surface. We further established a set of 42 proteins and 114 lipids features that served as hallmark features of non-EV particles in plasma. We submit ADAM10 and PS(36:1) as conserved EV biological markers that precisely differentiate between EV and non-EV particles. Our findings, which can be explored via an open-source Shiny web tool (evmap.shinyapps.io/evmap/), will serve as a valuable repository to the research community for a clearer understanding of circulating EV biology.