1,581 research outputs found
PromptInfuser: How Tightly Coupling AI and UI Design Impacts Designers' Workflows
Prototyping AI applications is notoriously difficult. While large language
model (LLM) prompting has dramatically lowered the barriers to AI prototyping,
designers are still prototyping AI functionality and UI separately. We
investigate how coupling prompt and UI design affects designers' workflows.
Grounding this research, we developed PromptInfuser, a Figma plugin that
enables users to create semi-functional mockups, by connecting UI elements to
the inputs and outputs of prompts. In a study with 14 designers, we compare
PromptInfuser to designers' current AI-prototyping workflow. PromptInfuser was
perceived to be significantly more useful for communicating product ideas, more
capable of producing prototypes that realistically represent the envisioned
artifact, more efficient for prototyping, and more helpful for anticipating UI
issues and technical constraints. PromptInfuser encouraged iteration over
prompt and UI together, which helped designers identify UI and prompt
incompatibilities and reflect upon their total solution. Together, these
findings inform future systems for prototyping AI applications
Nitrogen metabolism in Mycobacterium smegmatis
Nitrogen is an essential component of the bacterial cell and bacteria have developed elaborate regulatory mechanisms used to control the uptake, assimilation and metabolism of nitrogen. In this thesis, I have developed a nitrogen-limited continuous culture system to gain further insights into nitrogen metabolism in mycobacteria and their response to nitrogen limitation. I identified 357 differentially expressed genes in response to nitrogen limitation in continuous culture, including changes in amino acid metabolic pathways. I found 26 transcriptional regulators that mediated the global transcriptomic response of Mycobacterium smegmatis to nitrogen limitation and I identified several non-coding RNAs that might be involved in the regulation of nitrogen- regulated gene expression. Subsequently, I characterised two differentially expressed transcriptional regulators, AmtR (MSMEG_4300) and CadC (MSMEG_3297) using a combination of genome-wide expression profiling, physiological, biochemical and biophysical analyses. I identified the AmtR regulon and showed that AmtR was a transcriptional repressor of an urea degradation pathway. I identified xanthine and allantoin as ligands of mycobacterial AmtR and showed that addition of these metabolites had no effect on the release of AmtR from DNA. In further work, I demonstrated that deletion of the gene cadC in M. smegmatis resulted in a severe growth defect manifested as cell lysis during growth on rich medium. Subsequently, I identified the CadC regulon that included genes involved in the diaminopimelate (DAP) and lysine biosynthesis pathway. Supplementation with DAP or lysine could not rescue the growth defect of the âcadC mutant. Furthermore, I showed that M. smegmatis has a high-affinity lysine uptake system that exhibited high rates of lysine transport during growth in minimal medium, which was significantly reduced during growth in rich medium. My data suggest that a âcadC mutant is defective in the generation or replenishment of intracellular lysine and DAP levels that are essential for growth and survival in mycobacteria. I conclude that M. smegmatis has a broad network of regulatory systems that together enable M. smegmatis to adapt its nitrogen metabolism to rapidly changing environments
Cyclic nucleotide specificity of the activator and catalytic sites of a cGMP-stimulated cGMP phosphodiesterase from Dictyostelium discoideum
The cellular slime mold Dictyostelium discoideum has an intracellular phosphodiesterase which specifically hydrolyzes cGMP. The enzyme is activated by low cGMP concentrations, and is involved in the reduction of chemoattractant-mediated elevations of cGMP levels. The interaction of 20 cGMP derivatives with the activator site and with the catalytic site of the enzyme has been investigated. Binding of cGMP to the activator site is strongly reduced (more than 80-fold) if cGMP is no longer able to form a hydrogen bond at N2H2 or O2âH. Modifications at N7, C8, O3â and O5â induce only a small reduction of binding affinity. A cyclic phosphate structure, as well as a negatively charged oxygen atom at phosphorus, are essential to obtain activation of the enzyme. Substitution of the axial exocyclic oxygen atom by sulphur is tolerated; modification of the equatorial oxygen atom reduces the binding activity of cGMP to the activator site by 90-fold.
Binding of cGMP to the catalytic site is strongly reduced if cGMP is modified at N1H, C6O, C8 and O3â, while modifications at N2H2, N3, N7, O2âH, and O5â have minor effects. Both exocyclic oxygen atoms are important to obtain binding of cGMP to the catalytic site. The results indicate that activation of the enzyme by cGMP and hydrolysis of cGMP occur at different sites of the enzyme. cGMP is recognized at these sites by different types of molecular interaction between cGMP and the protein.
cGMP derivatives at concentrations which saturate the activator site do not induce the same degree of activation of the enzyme (activation 2.3-6.6-fold). The binding affinities of the analogues for the activator site and their maximal activation are not correlated. Our results suggest that the enzyme is activated because cGMP bound to the activator site stabilizes a state of the enzyme which has a higher affinity for cGMP at the catalytic site.
ConstitutionMaker: Interactively Critiquing Large Language Models by Converting Feedback into Principles
Large language model (LLM) prompting is a promising new approach for users to
create and customize their own chatbots. However, current methods for steering
a chatbot's outputs, such as prompt engineering and fine-tuning, do not support
users in converting their natural feedback on the model's outputs to changes in
the prompt or model. In this work, we explore how to enable users to
interactively refine model outputs through their feedback, by helping them
convert their feedback into a set of principles (i.e. a constitution) that
dictate the model's behavior. From a formative study, we (1) found that users
needed support converting their feedback into principles for the chatbot and
(2) classified the different principle types desired by users. Inspired by
these findings, we developed ConstitutionMaker, an interactive tool for
converting user feedback into principles, to steer LLM-based chatbots. With
ConstitutionMaker, users can provide either positive or negative feedback in
natural language, select auto-generated feedback, or rewrite the chatbot's
response; each mode of feedback automatically generates a principle that is
inserted into the chatbot's prompt. In a user study with 14 participants, we
compare ConstitutionMaker to an ablated version, where users write their own
principles. With ConstitutionMaker, participants felt that their principles
could better guide the chatbot, that they could more easily convert their
feedback into principles, and that they could write principles more
efficiently, with less mental demand. ConstitutionMaker helped users identify
ways to improve the chatbot, formulate their intuitive responses to the model
into feedback, and convert this feedback into specific and clear principles.
Together, these findings inform future tools that support the interactive
critiquing of LLM outputs
Designing Technology-Mediated Peer Support for Postgraduate Research Students at Risk of Loneliness and Isolation
Student mental health and wellbeing have come under increased scrutiny in recent years. Postgraduate research (PGR) students are at risk of experiencing mental health concerns and this, with the often isolated and competitive nature of their work, can impact their sense of community and social connectedness. In response to these concerns, we designed Pears, a system to connect PGR students for regular "pearings"(in-person meetings) and provide activities to promote reflection and conversation. A four-week evaluation of Pears with 15 students highlighted its potential to sometimes, but not always, facilitate peer support. Some participants would instead meet formally and according to their needs, others instead used the system to make new social connections. Additionally, some participants who faced work-related difficulties during the study found using the system contributed to their stress levels. We conclude by noting how technologies that encourage peer support can help build social relationships, providing an avenue to share similar PhD experiences and guidance for those new to the experience, while importantly raising awareness and an understanding for the need to take time for self-care. However, these technologies must be utilised carefully, and are not a replacement for other sources of student support in universities.</p
MIRTO: an open-source robotic platform for education
This paper introduces the MIddlesex RoboTic platfOrm (MIRTO), an open-source platform that has been used for teaching First Year Computer Science students since the academic year 2013/2014, with the aim of providing a physical manifestation of Software Engineering concepts that are often delivered using only abstract or synthetic case studies. In this paper we provide a detailed description of the platform, whose hardware specifications and software libraries are all released open source; we describe a number of teaching usages of the platform, report studentsâ projects, and evaluate some of its aspects in terms of effectiveness, usability, and maintenance
First Measurement of the Ru(p,)Rh Cross Section for the p-Process with a Storage Ring
This work presents a direct measurement of the Ru()Rh cross section via a novel technique using a storage ring,
which opens opportunities for reaction measurements on unstable nuclei. A
proof-of-principle experiment was performed at the storage ring ESR at GSI in
Darmstadt, where circulating Ru ions interacted repeatedly with a
hydrogen target. The Ru()Rh cross section between 9
and 11 MeV has been determined using two independent normalization methods. As
key ingredients in Hauser-Feshbach calculations, the -ray strength
function as well as the level density model can be pinned down with the
measured () cross section. Furthermore, the proton optical potential
can be optimized after the uncertainties from the -ray strength
function and the level density have been removed. As a result, a constrained
Ru()Rh reaction rate over a wide temperature range is
recommended for -process network calculations.Comment: 10 pages, 7 figs, Accepted for publication at PR
Measurements of proton-induced reactions on ruthenium-96 in the ESR at GSI
8th International Conference on Nuclear Physics at Storage Rings Stori11, October 9-14, 2011 Laboratori Nazionale di Frascati, Italy.
Storage rings offer the possibility of measuring proton- and alpha-induced reactions in inverse kinematics. The combination of this approachwith a radioactive beamfacility allows, in principle, the determination of the respective cross sections for radioactive isotopes. Such data are highly desired for a better understanding of astrophysical nucleosynthesis processes like the p-process. A pioneering experiment has been performed at the Experimental Storage Ring (ESR) at GSI using a stable 96Ru beam at 9-11 AMeV and a hydrogen target. Monte-Carlo simulations of the experiment were made using the Geant4 code. In these simulations, the experimental setup is described in detail and all reaction channels can be investigated. Based on the Geant4 simulations, a prediction of the shape of different spectral components can be performed. A comparison of simulated predictions with the experimental results shows a good agreement and allows the extraction of the cross section
Genome-wide meta-analysis implicates mediators of hair follicle development and morphogenesis in risk for severe acne
Acne vulgaris is a highly heritable common, chronic inflammatory disease of the skin for which five genetic risk loci have so far been identified. Here, we perform a genome-wide association study of 3823 cases and 16,144 controls followed by meta-analysis with summary statistics from a previous study, with a total sample size of 26,722. We identify 20 independent association signals at 15 risk loci, 12 of which have not been previously implicated in the disease. Likely causal variants disrupt the coding region of WNT10A and a P63 transcription factor binding site in SEMA4B. Risk alleles at the 1q25 locus are associated with increased expression of LAMC2, in which biallelic loss-of-function mutations cause the blistering skin disease epidermolysis bullosa. These findings indicate that variation affecting the structure and maintenance of the skin, in particular the pilosebaceous unit, is a critical aspect of the genetic predisposition to severe acne
System size and centrality dependence of the balance function in A+A collisions at sqrt[sNN]=17.2 GeV
Electric charge correlations were studied for p+p, C+C, Si+Si, and centrality selected Pb+Pb collisions at sqrt[sNN]=17.2 GeV with the NA49 large acceptance detector at the CERN SPS. In particular, long-range pseudorapidity correlations of oppositely charged particles were measured using the balance function method. The width of the balance function decreases with increasing system size and centrality of the reactions. This decrease could be related to an increasing delay of hadronization in central Pb+Pb collisions
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