Studies In Human Subjects Research Articles

Inflammasome functional activities in B lymphocytes.

Studies in animal models and human subjects have shown that, in addition to their implication in innate immunity, inflammasomes also can play a role in adaptive immunity. However, the contribution of the nucleotide-binding oligomerization domain-, leucine-rich repeat-, and pyrin domain-containing protein 3 (NLRP3) inflammasome pathway to adaptive immunity remains incompletely explored. Here, we show that NLRP3 plays an important role in different facets of B cell functions, including proliferation, antibody production, and secretion of inflammatory and anti-inflammatory cytokines. When exposed to B cell receptor engagement, Toll-like receptor activation, stimulation in conditions that mimic T cell-dependent responses, or NLRP3 activation, B cells manifest disparate responses and produce different cytokine patterns critical for modulating innate and adaptive immunity, indicating that the cytokines produced serve a critical link between the early innate immune response and the delayed adaptive immunity. Importantly, genetic ablation of nlrp3 reduced the inflammasome-mediated functions of B cells. We propose that, in the absence of other cell types, the potential of B lymphocytes to respond to NLRP3 engagement enables them to initiate inflammatory cascades through recruitment of other cell subsets, such as macrophages and neutrophils. Since NLRP3 activation of B cells is not followed by pyroptosis, even in the presence of a basal caspase-1 activity, this pathway acts as a bridge that optimizes interactions between the innate and adoptive branches of the immune response.

An Evaluation of Autologous Fat Injection as a Treatment for Velopharyngeal Insufficiency: A Review and Integrated Data Analysis.

Velopharyngeal insufficiency (VPI) is a condition characterized by incomplete separation of the oral and nasal cavities during speech production, thereby leading to speech abnormalities and audible nasal emissions. Subsequently, this adversely impacts communication and potentially interpersonal social interactions. Autologous fat grafting (AFG) to the velopharynx, a minimally invasive technique, aims to improve oronasal separation by providing bulk and advancing the posterior pharyngeal wall toward the soft palate. Despite its potential, the relative novelty of AFG in treating VPI has resulted in reporting of inconsistent indications, varied surgical techniques, and mixed outcomes across existing literature. This systemic review examined the evidence of AFG for VPI treatment over the past decade (2013-2023). A thorough search across five electronic databases yielded 233 studies, with 20 meeting the inclusion criteria (e.g., utilized fat injection as their selected VPI treatment, conducted study in human subjects, did not perform additional surgical procedure at time of fat injection). Selected studies encompassed patient and surgical intervention characteristics, perceptual speech assessment (PSA) scores, gap sizes, nasalance measurements, and complications. The majority of patients had a prior cleft palate diagnosis (78.2%), in which nasoendoscopy was the prevalent method for visualizing the velopharyngeal port defect. Fat harvesting predominantly occurred from the abdomen (64.3%), with an average injection volume of 6.3 mL across studies. PSA and subjective gap size scores were consistently higher preoperatively than postoperatively. PSA score analysis from seven studies revealed significant and sustained improvements postoperatively. Gap size score analysis from four studies demonstrated similar preoperative and postoperative differences. Complications were reported in 17 studies, yielding a 2.7% summative complication rate among 594 cases. Autologous fat grafting has emerged as a minimally invasive, safe, and effective treatment for mild to moderate VPI. However, challenges remain because of variability in patient selection criteria, diagnostic modalities, and outcome measurements. This review underscores the need for randomized control trials to directly compare AFG with standard-of-care surgical interventions, providing more conclusive evidence of its clinical efficacy.

Brain Vascular Expression of Monomeric C-Reactive Protein Is Blocked by C10M Following Intraperitoneal Injection in an ApoE-/- Murine Model of Dyslipidemia: An Immunohistochemical Analysis.

Introduction The neurovascular unit (NVU), comprising vascular and glial cells along with neurons, is vital for maintaining the blood-brain barrier (BBB) and cerebral homeostasis. Dysfunction of the NVU is implicated in key neurodegenerative disorders such as Alzheimer's disease (AD). Monomeric C-reactive protein (mCRP), the dissociated form of native, pentameric C-reactive protein (pCRP), is associated with enhanced pro-inflammatory responses in the vascular system, leading to increased permeability and potential NVU disruption. Methods This study utilized ApoE-/- mice receiving a high-fat diet which were injected intraperitoneally with either mCRP or mCRP together with a small molecule inhibitor (C10M) and investigated the deposition of mCRP and CD105 expression in the brain parenchyma and its localization within the microvasculature. Results Histological analysis revealed significant mCRP deposition in brain microvessels and neurons, indicating potential disruption of the BBB and neuronal damage. Moreover, co-administration of C10M effectively blocked mCRP accumulation in the brain parenchyma, suggesting its potential as a therapeutic agent for effectively inhibiting inflammation-associated degenerative changes. Immunohistochemical staining demonstrated co-localization of mCRP with CD105, indicating potential angiogenic activation and increased susceptibility to inflammatory insult. Discussion These findings provide evidence supporting the potential role of mCRP as a contributor to neuroinflammation in individuals with chronic systemic inflammation. Conclusion Further studies in human subjects should help validate the efficacy of C10M in preventing or halting neurodegeneration in conditions such as AD and stroke-associated dementia.

Development of a protocol for using geo-trackers to identify zoonotic enteric pathogen transmission pathways in a pilot study in Kenya

Abstract Humans and animals can be exposed to fecally-transmitted pathogens in both private and public domain environments. Animals may also acquire pathogen infections from these two environments and transmit them to humans through different pathways. Evidence on how often and where interactions occur between the two environments could improve the effectiveness of public health programs for preventing zoonotic disease transmission and response to disease outbreaks. This study aimed to develop a protocol for using geo-trackers to measure the spatial-temporal movement and interaction between animals and children in households and public areas in low- and middle-income categories of urban neighbourhoods in Kenya. It also aimed to identify opportunities and challenges for the scale-up of these methods’ for surveillance of other zoonotic diseases of public health significance. One commercial geo-tracker device with the best technological performance and usability that met pre-defined criteria for the study context was identified. Community engagement meetings were then conducted to gather input on a proposed study protocol. Afterwards, infants and animals were geo-tracked in 10 households in urban informal settlements of Kibera and Jericho, Nairobi over two consecutive weeks with iterative improvements to protocols. The effectiveness of the geo-tracking exercise was evaluated through in-depth interviews with Community Health Volunteers (CHVs) and infant caregivers. Animal and infant behaviour and battery reliability of the geo-trackers were also monitored; and observed opportunities and challenges in implementing the protocol during the exercise were documented. Community members were receptive and accepted the use of geo-trackers on animals and children. In pilot testing, there was no change of behaviour from 10 infants tracked. Discomfort was observed for up to 30 min after the placement for some of the seven animals tracked, but the animals quickly adjusted. The battery for all geo-tracker devices lasted for the 24-h geo-tracking period. Some caregivers and CHVs were concerned whether the geo-trackers could record personal information. It was shown that geo-tracker devices can be successfully deployed to study animal-child interactions and movement in different categories of urban neighbourhoods. Recommendations have been made on the lessons learnt from the study to help scientists who would use geo-trackers for future community-based human and animal research. One Health impact statement Assessing human and animal risks of acquiring enteric infections from environmental contamination, or contributing to pathogen contamination of the environment requires understanding spatial-temporal patterns of human and animal movement between private households and the community. Movement of domestic animals is relevant for understanding household-community spatial patterns of pathogen transmission because animal ownership and contact with humans is common, and free-roaming animals carrying enteric pathogens can spread diverse faecal pathogens between environments. The community-based participatory research approach of this study evaluated implementation feasibility from the lens of technical usability and reliability of geo-tracking devices, as well as social acceptability and ethics related to using such devices for the community-based study of human and animal subjects in urban settings. Evidence and recommendations from this study will be useful to anyone interested in understanding human-animal-environment interactions and their contributions to infectious disease transmission.

‘Why Didn’t You Allocate This Task to Them?’ Negotiation-Aware Task Allocation and Contrastive Explanation Generation

In this work, we design an Artificially Intelligent Task Allocator (AITA) that proposes a task allocation for a team of humans. A key property of this allocation is that when an agent with imperfect knowledge (about their teammate's costs and/or the team's performance metric) contests the allocation with a counterfactual, a contrastive explanation can always be provided to showcase why the proposed allocation is better than the proposed counterfactual. For this, we consider a negotiation process that produces a negotiation-aware task allocation and, when contested, leverages a negotiation tree to provide a contrastive explanation. With human subject studies, we show that the proposed allocation indeed appears fair to a majority of participants and, when not, the explanations generated are judged as convincing and easy to comprehend.

Dietary carbohydrates regulate intestinal colonization and dissemination of Klebsiella pneumoniae.

Bacterial translocation from the gut microbiota is a source of sepsis in susceptible patients. Previous work suggests that overgrowth of gut pathobionts, including Klebsiella pneumoniae, increases the risk of disseminated infection. Our data from a human dietary intervention study found that, in the absence of fiber, K. pneumoniae bloomed during microbiota recovery from antibiotic treatment. We thus hypothesized that dietary nutrients directly support or suppress colonization of this gut pathobiont in the microbiota. Consistent with our study in humans, complex carbohydrates in dietary fiber suppressed the colonization of K. pneumoniae and allowed for recovery of competing commensals in mouse models. In contrast, through ex vivo and in vivo modeling, we identified simple carbohydrates as a limiting resource for K. pneumoniae in the gut. As proof of principle, supplementation with lactulose, a nonabsorbed simple carbohydrate and an FDA-approved therapy, increased colonization of K. pneumoniae. Disruption of the intestinal epithelium led to dissemination of K. pneumoniae into the bloodstream and liver, which was prevented by dietary fiber. Our results show that dietary simple and complex carbohydrates were critical not only in the regulation of pathobiont colonization but also disseminated infection, suggesting that targeted dietary interventions may offer a preventative strategy in high-risk patients.

Increased gene dosage of RFWD2 causes autistic-like behaviors and aberrant synaptic formation and function in mice

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interactions, communication deficits and repetitive behaviors. A study of autistic human subjects has identified RFWD2 as a susceptibility gene for autism, and autistic patients have 3 copies of the RFWD2 gene. The role of RFWD2 as an E3 ligase in neuronal functions, and its contribution to the pathophysiology of ASD, remain unknown. We generated RFWD2 knockin mice to model the human autistic condition of high gene dosage of RFWD2. We found that heterozygous knockin (Rfwd2+/−) male mice exhibited the core symptoms of autism. Rfwd2+/− male mice showed deficits in social interaction and communication, increased repetitive and anxiety-like behavior, and spatial memory deficits, whereas Rfwd2+/− female mice showed subtle deficits in social communication and spatial memory but were normal in anxiety-like, repetitive, and social behaviors. These autistic-like behaviors in males were accompanied by a reduction in dendritic spine density and abnormal synaptic function on layer II/III pyramidal neurons in the prelimbic area of the medial prefrontal cortex (mPFC), as well as decreased expression of synaptic proteins. Impaired social behaviors in Rfwd2+/− male mice were rescued by the expression of ETV5, one of the major substrates of RFWD2, in the mPFC. These findings indicate an important role of RFWD2 in the pathogenesis of autism.

A compressomyograph train of four monitoring device

The monitoring of the neuromuscular blockade is critical for patient's safety during and after surgery. The monitoring of neuromuscular blockade often requires the use of Train of Four (TOF) technique. During a TOF test two electrodes are attached to the ulnar nerve, and a series of four electric pulses are applied. The electrical stimulation causes the thumb to twitch, and the amount of twitch varies depending on the amount of neuromuscular blockade in patient's system. Current medical devices used to assist anesthesiologists to perform TOF monitoring often require free hand movement and do not provide accurate or reliable results. The goal of this work is to design, prototype and test a new medical device that provides reliable TOF results when thumb movement is restricted. A medical device that uses a pressurized catheter balloon to detect the response thumb twitch of the TOF test is created. An analytical model, numerical study, and mechanical finger testing were employed to create an optimum design. The design is tested through a pilot human subjects study. No significant correlation is reported with subjects’ properties, including hand size.

Palpation Versus Ultrasonography for Identifying the Cricothyroid Membrane in Case of a Laterally Deviated Larynx: A Randomized Trial.

Large neck circumference and displacement of the trachea due to pathology increase the risk of failed identification of the cricothyroid membrane and cricothyroidotomy. We investigated whether ultrasound aids in the successful identification of the cricothyroid membrane in a model of an obese neck with midline deviation of the trachea. We developed silicone neck models that were suitable for both palpation and ultrasonography and where the trachea deviated laterally from the midline to either side. After reading a book chapter and participating in a 25-minute lecture and a 15- to 23-minute hands-on demonstration and rehearsal of ultrasonography for identification of the cricothyroid membrane, anesthesiologists and anesthesiology residents randomly performed identification with either ultrasound or palpation on 1 of 2 neck models. We included 57 participants, of whom 29 and 28 were randomized to palpation and ultrasound, respectively. Correct identification of the cricothyroid membrane was achieved by 21 (75.0%) vs 1 (3.5%) of participants in the ultrasound versus palpation groups (risk ratio [RR], 21.8 [95% confidence interval {CI}, 3.1-151.0]). The tracheal midline position in the sagittal plane was identified correctly by 24 (85.7%) vs 16 (55.2%) of participants in the ultrasound versus palpation groups (RR, 1.6 [95% CI, 1.1-2.2]). Identification of the cricothyroid membrane in a model of an obese neck with midline deviation of the trachea was more often successful with ultrasound compared to palpation. Our study supports the potential use of ultrasound before induction of anesthesia and airway management in this group of patients, and it may even be applied in emergency situations when ultrasound is readily available. Further studies in human subjects should be conducted.

Synthesis and PET Imaging Biodistribution Studies of Radiolabeled Iododiflunisal, a Transthyretin Tetramer Stabilizer, Candidate Drug for Alzheimer's Disease.

The small-molecule iododiflunisal (IDIF) is a transthyretin (TTR) tetramer stabilizer and acts as a chaperone of the TTR-Amyloid beta interaction. Oral administration of IDIF improves Alzheimer's Disease (AD)-like pathology in mice, although the mechanism of action and pharmacokinetics remain unknown. Radiolabeling IDIF with positron or gamma emitters may aid in the in vivo evaluation of IDIF using non-invasive nuclear imaging techniques. In this work, we report an isotopic exchange reaction to obtain IDIF radiolabeled with 18F. [19F/18F]exchange reaction over IDIF in dimethyl sulfoxide at 160 °C resulted in the formation of [18F]IDIF in 7 ± 3% radiochemical yield in a 20 min reaction time, with a final radiochemical purity of >99%. Biodistribution studies after intravenous administration of [18F]IDIF in wild-type mice using positron emission tomography (PET) imaging showed capacity to cross the blood-brain barrier (ca. 1% of injected dose per gram of tissue in the brain at t > 10 min post administration), rapid accumulation in the liver, long circulation time, and progressive elimination via urine. Our results open opportunities for future studies in larger animal species or human subjects.

Could admission level of uric acid predict total diuretic dose in acute heart failure?

BackgroundRecent studies have shown that increases in serum UA levels are associated with adverse clinical outcomes in patients with chronic heart failure (CHF); the aim of this study was to determine the relationship between serum uric acid and total diuretic dose received during hospitalization in hospitalized patients with acute exacerbation of heart failure. The main purpose of this study is to determine the role of uric acid as a biomarker that can be a substitute for pro-BNP in clinical evaluation and the need for diuretics in hospitalized patients with acute heart failure.MethodsAfter approving the plan in the Research Council of the Heart Department and obtaining an ethical code from the Regional Committee on Research Ethics (Human Subjects Studies), the researcher referred to the archives of our center, the case of 100 patients diagnosed with acute heart failure. Cardiac patients were selected, and the information required for the study was collected using a pre-prepared data collection form, and the information was entered into SPSS software after categorization and appropriate analysis and statistical tests were performed on it. Were performed and in all statistical tests the statistical significance level was considered 0.05:Results100 patients with acute heart failure were included in this study with a mean age of 63.43 ± 14.78 years. 66% of them were men. The mean dose of furosemide in these patients was 680.92 ± 377.47 mg and the mean serum uric acid level in these patients was 8.55 ± 2.50 mg / dL. In the study of the relationship between the variables, there was a significant relationship between the dose of furosemide received with the serum level of serum uric acid (P = 0.017, r = 0.248 and P = 0.009, r = -0.267, respectively). There is also a significant relationship between serum uric acid level and patient mortality (P = 0.013, r = 0.247). However this relationship lost its significance after multivariate analysis.ConclusionThere is a significant relationship between serum uric acid level and diuretic use. However, in-hospital mortality is not related to uric acid levels at admission.

Analysis of Human Peripheral Blood Mononuclear Cells in Patients with Neurodegenerative Diseases.

The role of immune system in the progression of neurodegenerative diseases has been studied for decades in animal models. However, invasive studies in human subjects remain controversial due to the heterogeneity of the presentation of different diagnostic categories at different stages of the disease. Peripheral blood mononuclear cells (PBMCs) contain immune cells including dendritic cells (DCs), monocytes, macrophages, and T lymphocytes. Isolating PBMCs from whole blood samples collected from patients provides a minimally invasive method for analyzing the immune system's function in patients with neurodegenerative diseases. By isolating single cell types from patients' peripheral blood, in vitro analyses can be conducted including RNA sequencing, immunofluorescence, and phagocytic analysis. In this chapter, we discuss PBMC separation and isolation of macrophages in pure culture in vitro. We also outline methods for performing RNA-seq on cultured macrophages and other techniques for investigating the role of macrophages in neurodegenerative disease pathophysiology.

Object Detection and Text Recognition for Immersive Augmented Reality Training in Laser Powder Bed Fusion

Professional Training for laser powder bed fusion equipment operation typically is time consuming and expensive for end-users in metal Additive Manufacturing (AM). This study proposes a practical solution by leveraging Hyperskill software to develop a immersive training program compatible with Augmented Reality (AR) devices. The program incorporates the YOLOv7 object detection algorithm and the CRAFT(Character Region Awareness for Text detection) Four-stage text recognition algorithm, seamlessly bridging the gap between reality and simulation. Through a human subjects study, we demonstrate the effectiveness and viability of the AR program, showcasing its capacity to deliver real-time, comprehensive training in metal AM processes. This approach offers a balanced and efficient solution for improving professional training in the field of metal AM.

Data-Driven Hypothesis Generation in Clinical Research: What We Learned from a Human Subject Study?

Hypothesis generation is an early and critical step in any hypothesis-driven clinical research project. Because it is not yet a well-understood cognitive process, the need to improve the process goes unrecognized. Without an impactful hypothesis, the significance of any research project can be questionable, regardless of the rigor or diligence applied in other steps of the study, e.g., study design, data collection, and result analysis. In this perspective article, the authors provide a literature review on the following topics first: scientific thinking, reasoning, medical reasoning, literature-based discovery, and a field study to explore scientific thinking and discovery. Over the years, scientific thinking has shown excellent progress in cognitive science and its applied areas: education, medicine, and biomedical research. However, a review of the literature reveals the lack of original studies on hypothesis generation in clinical research. The authors then summarize their first human participant study exploring data-driven hypothesis generation by clinical researchers in a simulated setting. The results indicate that a secondary data analytical tool, VIADS-a visual interactive analytic tool for filtering, summarizing, and visualizing large health data sets coded with hierarchical terminologies, can shorten the time participants need, on average, to generate a hypothesis and also requires fewer cognitive events to generate each hypothesis. As a counterpoint, this exploration also indicates that the quality ratings of the hypotheses thus generated carry significantly lower ratings for feasibility when applying VIADS. Despite its small scale, the study confirmed the feasibility of conducting a human participant study directly to explore the hypothesis generation process in clinical research. This study provides supporting evidence to conduct a larger-scale study with a specifically designed tool to facilitate the hypothesis-generation process among inexperienced clinical researchers. A larger study could provide generalizable evidence, which in turn can potentially improve clinical research productivity and overall clinical research enterprise.

2D, 2.5D, or 3D? An Exploratory Study on Multilayer Network Visualisations in Virtual Reality.

Relational information between different types of entities is often modelled by a multilayer network (MLN) - a network with subnetworks represented by layers. The layers of an MLN can be arranged in different ways in a visual representation, however, the impact of the arrangement on the readability of the network is an open question. Therefore, we studied this impact for several commonly occurring tasks related to MLN analysis. Additionally, layer arrangements with a dimensionality beyond 2D, which are common in this scenario, motivate the use of stereoscopic displays. We ran a human subject study utilising a Virtual Reality headset to evaluate 2D, 2.5D, and 3D layer arrangements. The study employs six analysis tasks that cover the spectrum of an MLN task taxonomy, from path finding and pattern identification to comparisons between and across layers. We found no clear overall winner. However, we explore the task-to-arrangement space and derive empirical-based recommendations on the effective use of 2D, 2.5D, and 3D layer arrangements for MLNs.

A Comparative Study of the Perceptual Sensitivity of Topological Visualizations to Feature Variations.

Color maps are a commonly used visualization technique in which data are mapped to optical properties, e.g., color or opacity. Color maps, however, do not explicitly convey structures (e.g., positions and scale of features) within data. Topology-based visualizations reveal and explicitly communicate structures underlying data. Although our understanding of what types of features are captured by topological visualizations is good, our understanding of people's perception of those features is not. This paper evaluates the sensitivity of topology-based isocontour, Reeb graph, and persistence diagram visualizations compared to a reference color map visualization for synthetically generated scalar fields on 2-manifold triangular meshes embedded in 3D. In particular, we built and ran a human-subject study that evaluated the perception of data features characterized by Gaussian signals and measured how effectively each visualization technique portrays variations of data features arising from the position and amplitude variation of a mixture of Gaussians. For positional feature variations, the results showed that only the Reeb graph visualization had high sensitivity. For amplitude feature variations, persistence diagrams and color maps demonstrated the highest sensitivity, whereas isocontours showed only weak sensitivity. These results take an important step toward understanding which topology-based tools are best for various data and task scenarios and their effectiveness in conveying topological variations as compared to conventional color mapping.

Impact of Formulation and Microneedle Length on Transdermal Metronidazole Permeation through Microneedle-Treated Skin.

This study aimed to determine the impact of formulation (gel vs cream) and microneedle characteristics (length, number) on permeation of metronidazole through excised microneedle-treated skin. The long-term goal is to apply these results towards a pharmacokinetic study in human subjects with diverse skin types, using in vitro flux data to determine dosing conditions and ultimately establish in vitro-in vivo correlations. Metronidazole release from 0.75% gel and cream was quantified with flow-through diffusion cells, using a cellulose membrane. Excised porcine skin was treated with stainless steel microneedles (500 or 800μm length), to create 50 or 100 micropores. Metronidazole gel or cream was applied to microneedle-treated skin and replaced every 48h for up to 7days. Metronidazole permeation was quantified using HPLC. Intact skin (no microneedle treatment) served as controls. Metronidazole release was faster from the gel vs cream. At 7days there was no difference between gel vs cream in total metronidazole permeated through intact skin. For both formulations, metronidazole permeation was significantly higher (vs intact skin) following microneedle application, regardless of microneedle length or micropore number. Increasing microneedle length and micropore number enhanced MTZ permeation multiple fold for both gel and cream. The greatest enhancement in total permeation for both formulations was achieved with the 800μm MN, 100 micropore condition. Formulation and microneedle conditions both impacted metronidazole permeation. These data will be used to estimate in vivo serum concentrations after applying metronidazole to microneedle-treated skin in humans.

Validation of a good manufacturing practice procedure for the production of [11C]AZD4747, a CNS penetrant KRASG12c inhibitor.

AZD4747 is a KRASG12C inhibitor recently shown to cross the non-human primate blood-brain barrier efficiently. In the current study, a GMP-compliant production of [11C]AZD4747 was developed to enable PET studies in human subjects. The validated procedure afforded [11C]AZD4747 as an injectable solution in good radioactivity yield (1656 ± 532 MBq), excellent radiochemical purity (100%), and a molar activity of 77 ± 13 GBq/μmol at the end of the synthesis, which took 46 ± 1min from the end of the bombardment. Quality control on the final product was performed satisfactorily and met all acceptance criteria.

The Influence of Digital Sketching Tools on Concept Novelty and Evolution

Abstract Digital tools for sketching, such as tablets, have become popular for streamlining design work and keeping a large quantity of sketches in one place. However, their impact on design creativity, novelty, and concept evolution is not yet well understood. Here, we present a controlled human subjects study that assesses the influence of tablets (iPads) on concept novelty and evolution in the context of an engineering design concept generation exercise. We expect that iPad use will not influence concept novelty due to its similar speed of use as pen and paper sketching. We expect to see different patterns in concept evolution between the two types of tools, namely, that iPad users will demonstrate more iteration on a concept (concept evolution) than pen and paper users due to the fact that iPad features make it easy to copy and paste previous sketches and then modify them. We find that the tool used is not correlated with concept novelty. Additionally, we find no strong differences in overall concept evolution quantities between the two tools, though we see that iPad sketches exhibited more cases of consecutive concept evolution than nonconsecutive whereas paper and pen sketches showed an equal amount of both consecutive and nonconsecutive concept evolution. Results indicate that overall, iPads may not significantly inhibit designers’ creative skills and thus could be a reasonable replacement for pen and paper sketching, which has implications for both design education and practice.

Explainable Activity Recognition in Videos using Deep Learning and Tractable Probabilistic Models

We consider the following video activity recognition (VAR) task: given a video, infer the set of activities being performed in the video and assign each frame to an activity. Although VAR can be solved accurately using existing deep learning techniques, deep networks are neither interpretable nor explainable and as a result their use is problematic in high stakes decision-making applications (in healthcare, experimental Biology, aviation, law, etc.). In such applications, failure may lead to disastrous consequences and therefore it is necessary that the user is able to either understand the inner workings of the model or probe it to understand its reasoning patterns for a given decision. We address these limitations of deep networks by proposing a new approach that feeds the output of a deep model into a tractable, interpretable probabilistic model called a dynamic conditional cutset network that is defined over the explanatory and output variables and then performing joint inference over the combined model. The two key benefits of using cutset networks are: (a) they explicitly model the relationship between the output and explanatory variables and as a result, the combined model is likely to be more accurate than the vanilla deep model and (b) they can answer reasoning queries in polynomial time and as a result, they can derive meaningful explanations by efficiently answering explanation queries. We demonstrate the efficacy of our approach on two datasets, Textually Annotated Cooking Scenes (TACoS), and wet lab, using conventional evaluation measures such as the Jaccard Index and Hamming Loss, as well as a human-subjects study.